Publications by authors named "Martin W McBride"

43 Publications

Distinct uterine artery gene expression profiles during early gestation in the stroke-prone spontaneously hypertensive rat.

Physiol Genomics 2021 Apr 15;53(4):160-171. Epub 2021 Mar 15.

British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Scotland, United Kingdom.

During pregnancy, the uterine spiral arteries undergo major vascular remodeling to ensure sufficient uteroplacental perfusion to support the fetus. In pregnancies complicated by hypertensive disorders, this remodeling is deficient leading to impaired uteroplacental blood flow and poor maternal and fetal outcomes. The underlying genetic mechanisms for failed vascular remodeling are not fully understood. This study aimed to examine the early-pregnancy-associated gene changes in the uterine arteries of spontaneously hypertensive stroke-prone rats (SHRSP) compared with their normotensive counterparts, Wistar-Kyoto rats (WKY). Uterine arteries from WKY and SHRSP were processed for RNA-sequencing, along with virgin, age-matched controls for each strain. Gene expression changes were identified and biological pathways were implicated and interpretated using ingenuity pathway analysis (IPA). This study found that WKY uterine arteries from early pregnancy exhibit a gene expression pattern that is suggestive of a pregnancy-dependent reduction in Ca handling and renin-angiotensin-aldosterone system (RAAS) components and an increase in ATP production. In contrast, the expression pattern of pregnant SHRSP uterine arteries was dominated by an elevated immune response and increased production of reactive oxygen species (ROS) and downstream effectors of the RAAS. These results suggest that in a rat model, hypertension during pregnancy impacts uterine artery gene expression patterns as early as the first week of pregnancy. The pathway changes involved may underlie or contribute to the adverse vascular remodeling and resultant placental ischemia and systemic vascular dysfunction observed in SHRSP in late gestation.
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http://dx.doi.org/10.1152/physiolgenomics.00159.2020DOI Listing
April 2021

From animal models to patients: the role of placental microRNAs, miR-210, miR-126, and miR-148a/152 in preeclampsia.

Clin Sci (Lond) 2020 04;134(8):1001-1025

Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, U.K.

Placental microRNAs (miRNAs) regulate the placental transcriptome and play a pathological role in preeclampsia (PE), a hypertensive disorder of pregnancy. Three PE rodent model studies explored the role of placental miRNAs, miR-210, miR-126, and miR-148/152 respectively, by examining expression of the miRNAs, their inducers, and potential gene targets. This review evaluates the role of miR-210, miR-126, and miR-148/152 in PE by comparing findings from the three rodent model studies with in vitro studies, other animal models, and preeclamptic patients to provide comprehensive insight into genetic components and pathological processes in the placenta contributing to PE. The majority of studies demonstrate miR-210 is upregulated in PE in part driven by HIF-1α and NF-κBp50, stimulated by hypoxia and/or immune-mediated processes. Elevated miR-210 may contribute to PE via inhibiting anti-inflammatory Th2-cytokines. Studies report an up- and downregulation of miR-126, arguably reflecting differences in expression between cell types and its multifunctional capacity. MiR-126 may play a pro-angiogenic role by mediating the PI3K-Akt pathway. Most studies report miR-148/152 family members are upregulated in PE. Evidence suggests they may inhibit DNA methylation of genes involved in metabolic and inflammatory pathways. Given the genetic heterogeneity of PE, it is unlikely that a single placental miRNA is a suitable therapeutic target for all patients. Investigating miRNAs in PE subtypes in patients and animal models may represent a more appropriate approach going forward. Developing methods for targeting placental miRNAs and specific placental cell types remains crucial for research seeking to target placental miRNAs as a novel treatment for PE.
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http://dx.doi.org/10.1042/CS20200023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7239341PMC
April 2020

Transgenic overexpression of glutathione S-transferase μ-type 1 reduces hypertension and oxidative stress in the stroke-prone spontaneously hypertensive rat.

J Hypertens 2019 05;37(5):985-996

Institute of Cardiovascular & Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK.

Background: Combined congenic breeding and microarray gene expression profiling previously identified glutathione S-transferase μ-type 1 (Gstm1) as a positional and functional candidate gene for blood pressure (BP) regulation in the stroke-prone spontaneously hypertensive (SHRSP) rat. Renal Gstm1 expression in SHRSP rats is significantly reduced when compared with normotensive Wistar Kyoto (WKY) rats. As Gstm1 plays an important role in the secondary defence against oxidative stress, significantly lower expression levels may be functionally relevant in the development of hypertension. The aim of this study was to investigate the role of Gstm1 in BP regulation and oxidative stress by transgenic overexpression of the Gstm1 gene.

Method: Two independent Gstm1 transgenic SHRSP lines were generated by microinjecting SHRSP embryos with a linear construct controlled by the EF-1α promoter encoding WKY Gstm1 cDNA [SHRSP-Tg(Gstm1)1 and SHRSP-Tg(Gstm1)2].

Results: Transgenic rats exhibit significantly reduced BP and pulse pressure when compared with SHRSP [systolic: SHRSP 205.2 ± 3.7 mmHg vs. SHRSP-Tg(Gstm1)1 175.5 ± 1.6 mmHg and SHRSP-Tg(Gstm1)2 172 ± 3.2 mmHg, P < 0.001; pulse pressure: SHRSP 58.4 ± 0.73 mmHg vs. SHRSP-Tg(Gstm1)1 52.7 ± 0.19 mmHg and SHRSP-Tg(Gstm1)2 40.7 ± 0.53 mmHg, P < 0.001]. Total renal and aortic Gstm1 expression in transgenic animals was significantly increased compared with SHRSP [renal relative quantification (RQ): SHRSP-Tg(Gstm1)1 1.95 vs. SHRSP 1.0, P < 0.01; aorta RQ: SHRSP-Tg(Gstm1)1 2.8 vs. SHRSP 1.0, P < 0.05]. Renal lipid peroxidation (malondialdehyde: protein) and oxidized : reduced glutathione ratio levels were significantly reduced in both transgenic lines when compared with SHRSP [malondialdehyde: SHRSP 0.04 ± 0.009 μmol/l vs. SHRSP-Tg(Gstm1)1 0.024 ± 0.002 μmol/l and SHRSP-Tg(Gstm1)2 0.021 ± 0.002 μmol/l; (oxidized : reduced glutathione ratio): SHRSP 5.19 ± 2.26 μmol/l vs. SHRSP-Tg(Gstm1)1 0.17 ± 0.11 μmol/l and SHRSP-Tg(Gstm1)2 0.47 ± 0.22 μmol/l]. Transgenic SHRSP rats containing the WKY Gstm1 gene demonstrate significantly lower BP, reduced oxidative stress and improved levels of renal Gstm1 expression.

Conclusion: These data support the hypothesis that reduced renal Gstm1 plays a role in the development of hypertension.
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http://dx.doi.org/10.1097/HJH.0000000000001960DOI Listing
May 2019

Salt stress in the renal tubules is linked to TAL-specific expression of uromodulin and an upregulation of heat shock genes.

Physiol Genomics 2018 11 14;50(11):964-972. Epub 2018 Sep 14.

The British Heart Foundation Centre of Excellence, Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow , Glasgow , United Kingdom.

Previously, our comprehensive cardiovascular characterization study validated Uromodulin as a blood pressure gene. Uromodulin is a glycoprotein exclusively synthesized at the thick ascending limb of the loop of Henle and is encoded by the Umod gene. Umod mice have significantly lower blood pressure than Umod mice, are resistant to salt-induced changes in blood pressure, and show a leftward shift in pressure-natriuresis curves reflecting changes of sodium reabsorption. Salt stress triggers transcription factors and genes that alter renal sodium reabsorption. To date there are no studies on renal transcriptome responses to salt stress. Here we aimed use RNA-Seq to delineate salt stress pathways in tubules isolated from Umod mice (a model of sodium retention) and Umod mice (a model of sodium depletion) ± 300 mosmol sodium chloride ( n = 3 per group). In response to salt stress, the tubules of Umod mice displayed an upregulation of heat shock transcripts. The greatest changes occurred in the expression of: Hspa1a (Log2 fold change 4.35, P = 2.48 e) and Hspa1b (Log2 fold change 4.05, P = 2.48 e). This response was absent in tubules of Umod mice. Interestingly, seven of the genes discordantly expressed in the Umod tubules were electrolyte transporters. Our results are the first to show that salt stress in renal tubules alters the transcriptome, increasing the expression of heat shock genes. This direction of effect in Umod tubules suggest the difference is due to the presence of Umod facilitating greater sodium entry into the tubule cell reflecting a specific response to salt stress.
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http://dx.doi.org/10.1152/physiolgenomics.00057.2018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6293113PMC
November 2018

Modeling Superimposed Preeclampsia Using Ang II (Angiotensin II) Infusion in Pregnant Stroke-Prone Spontaneously Hypertensive Rats.

Hypertension 2018 07 29;72(1):208-218. Epub 2018 May 29.

From the BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (H.L.M., E. Butler, S.R., E. Beattie, M.W.M., D.G.).

Hypertensive disorders of pregnancy are the second leading cause of maternal deaths worldwide. Superimposed preeclampsia is an increasingly common problem and often associated with impaired placental perfusion. Understanding the underlying mechanisms and developing treatment options are crucial. The pregnant stroke-prone spontaneously hypertensive rat has impaired uteroplacental blood flow and abnormal uterine artery remodeling. We used Ang II (angiotensin II) infusion in pregnant stroke-prone spontaneously hypertensive rats to mimic the increased cardiovascular stress associated with superimposed preeclampsia and examine the impact on the maternal cardiovascular system and fetal development. Continuous infusion of Ang II at 500 or 1000 ng/kg per minute was administered from gestational day 10.5 until term. Radiotelemetry and echocardiography were used to monitor hemodynamic and cardiovascular changes, and urine was collected prepregnancy and throughout gestation. Uterine artery myography assessed uteroplacental vascular function and structure. Fetal measurements were made at gestational day 18.5, and placentas were collected for histological and gene expression analyses. The 1000 ng/kg per minute Ang II treatment significantly increased blood pressure (<0.01), reduced cardiac output (<0.05), and reduced diameter and increased stiffness of the uterine arteries (<0.01) during pregnancy. The albumin:creatinine ratio was increased in both Ang II treatment groups (<0.05; <0.0001). The 1000 ng/kg per minute-treated fetuses were significantly smaller than vehicle treatment (<0.001). Placental expression of Ang II receptors was increased in the junctional zone in 1000 ng/kg per minute Ang II-treated groups (<0.05), with this zone showing depletion of glycogen content and structural abnormalities. Ang II infusion in pregnant stroke-prone spontaneously hypertensive rats mirrors hemodynamic, cardiac, and urinary profiles observed in preeclamptic women, with evidence of impaired fetal growth.
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http://dx.doi.org/10.1161/HYPERTENSIONAHA.118.10935DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6012051PMC
July 2018

Effects of dietary salt on gene and protein expression in brain tissue of a model of sporadic small vessel disease.

Clin Sci (Lond) 2018 06 26;132(12):1315-1328. Epub 2018 Jun 26.

Centre for Clinical Brain Sciences, and UK Dementia Research Institute at the University of Edinburgh, Chancellors Building, 49 Little France Crescent, Edinburgh EH16 4SB, U.K.

Background: The effect of salt on cerebral small vessel disease (SVD) is poorly understood. We assessed the effect of dietary salt on cerebral tissue of the stroke-prone spontaneously hypertensive rat (SHRSP) - a relevant model of sporadic SVD - at both the gene and protein level. Methods Brains from 21-week-old SHRSP and Wistar-Kyoto rats, half additionally salt-loaded (via a 3-week regime of 1% NaCl in drinking water), were split into two hemispheres and sectioned coronally - one hemisphere for mRNA microarray and qRT-PCR, the other for immunohistochemistry using a panel of antibodies targeting components of the neurovascular unit. Results We observed differences in gene and protein expression affecting the acute phase pathway and oxidative stress ( and , up-regulated in salt-loaded WKY versus WKY, >2-fold), active microglia (increased Iba-1 protein expression in salt-loaded SHRSP versus salt-loaded WKY, p<0.05), vascular structure ( and , up-regulated in salt-loaded SHRSP versus SHRSP, >3-fold; and down-regulated >2-fold in salt-loaded SHRSP versus SHRSP) and myelin integrity ( down-regulated in salt loaded WKY rats versus WKY, >2.5-fold). Changes of salt-loading were more pronounced in SHRSP and occurred without an increase in blood pressure in WKY rats.

Conclusion: Salt exposure induced changes in gene and protein expression in an experimental model of SVD and its parent rat strain in multiple pathways involving components of the glio-vascular unit. Further studies in pertinent experimental models at different ages would help clarify the short- and long-term effect of dietary salt in SVD.
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http://dx.doi.org/10.1042/CS20171572DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6365623PMC
June 2018

Runx1 Deficiency Protects Against Adverse Cardiac Remodeling After Myocardial Infarction.

Circulation 2018 01 13;137(1):57-70. Epub 2017 Oct 13.

Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, University Place, UK (C.S.M., W.H., A.B., K.M., F.V., K.N., C.F., A.R., P.B., E.B.E., C.H., S.M.M., G.L.S., M.W.M., S.A.N., C.M.L.).

Background: Myocardial infarction (MI) is a leading cause of heart failure and death worldwide. Preservation of contractile function and protection against adverse changes in ventricular architecture (cardiac remodeling) are key factors to limiting progression of this condition to heart failure. Consequently, new therapeutic targets are urgently required to achieve this aim. Expression of the Runx1 transcription factor is increased in adult cardiomyocytes after MI; however, the functional role of Runx1 in the heart is unknown.

Methods: To address this question, we have generated a novel tamoxifen-inducible cardiomyocyte-specific -deficient mouse. Mice were subjected to MI by means of coronary artery ligation. Cardiac remodeling and contractile function were assessed extensively at the whole-heart, cardiomyocyte, and molecular levels.

Results: -deficient mice were protected against adverse cardiac remodeling after MI, maintaining ventricular wall thickness and contractile function. Furthermore, these mice lacked eccentric hypertrophy, and their cardiomyocytes exhibited markedly improved calcium handling. At the mechanistic level, these effects were achieved through increased phosphorylation of phospholamban by protein kinase A and relief of sarco/endoplasmic reticulum Ca-ATPase inhibition. Enhanced sarco/endoplasmic reticulum Ca-ATPase activity in Runx1-deficient mice increased sarcoplasmic reticulum calcium content and sarcoplasmic reticulum-mediated calcium release, preserving cardiomyocyte contraction after MI.

Conclusions: Our data identified Runx1 as a novel therapeutic target with translational potential to counteract the effects of adverse cardiac remodeling, thereby improving survival and quality of life among patients with MI.
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http://dx.doi.org/10.1161/CIRCULATIONAHA.117.028911DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5757664PMC
January 2018

HLA gene expression is altered in whole blood and placenta from women who later developed preeclampsia.

Physiol Genomics 2017 03 27;49(3):193-200. Epub 2017 Jan 27.

Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom; and.

Preeclampsia is a multisystem disease that significantly contributes to maternal and fetal morbidity and mortality. In this study, we used a non-biased microarray approach to identify dysregulated genes in maternal whole blood samples which may be associated with the development of preeclampsia. Whole blood samples were obtained at 28 wk of gestation from 5 women who later developed preeclampsia (cases) and 10 matched women with normotensive pregnancies (controls). Placenta samples were obtained from an independent cohort of 19 women with preeclampsia matched with 19 women with normotensive pregnancies. We studied gene expression profiles using Illumina microarray in blood and validated changes in gene expression in whole blood and placenta tissue by qPCR. We found a transcriptional profile differentiating cases from controls; 336 genes were significantly dysregulated in blood from women who developed preeclampsia. Functional annotation of microarray results indicated that most of the genes found to be dysregulated were involved in inflammatory pathways. While general trends were preserved, only was validated in whole blood samples from cases using qPCR (2.30- ± 0.9-fold change) whereas in placental tissue expression was found to be significantly increased in samples from women with preeclampsia (5.88- ± 2.24-fold change). We have identified that is upregulated in the circulation of women who went on to develop preeclampsia. In placenta of women with preeclampsia we identified that upregulated. Our data provide further evidence for involvement of the gene family in the pathogenesis of preeclampsia.
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http://dx.doi.org/10.1152/physiolgenomics.00106.2016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5374453PMC
March 2017

Dissecting the genetic components of a quantitative trait locus for blood pressure and renal pathology on rat chromosome 3.

J Hypertens 2017 02;35(2):319-329

aInstitute of Cardiovascular & Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK bDepartment of Anatomical Pathology, Pathology North (Hunter), John Hunter Hospital, New Lambton, New South Wales, Australia.

Background: We have previously confirmed the importance of rat chromosome 3 (RNO3) genetic loci on blood pressure elevation, pulse pressure (PP) variability and renal pathology during salt challenge in the stroke-prone spontaneously hypertensive (SHRSP) rat. The aims of this study were to generate a panel of RNO3 congenic sub-strains to genetically dissect the implicated loci and identify positional candidate genes by microarray expression profiling and analysis of next-generation sequencing data.

Method And Results: A panel of congenic sub-strains were generated containing Wistar-Kyoto (WKY)-introgressed segments of varying size on the SHRSP genetic background, focused within the first 50 Mbp of RNO3. Haemodynamic profiling during salt challenge demonstrated significantly reduced systolic blood pressure, diastolic blood pressure and PP variability in SP.WKYGla3a, SP.WKYGla3c, SP.WKYGla3d and SP.WKYGla3e sub-strains. Only SBP and DBP were significantly reduced during salt challenge in SP.WKYGla3b and SP.WKYGla3f sub-strains, whereas SP.WKYGla3g rats did not differ in haemodynamic response to SHRSP. Those sub-strains demonstrating significantly reduced PP variability during salt challenge also demonstrated significantly reduced renal pathology and proteinuria. Microarray expression profiling prioritized two candidate genes for blood pressure regulation (Dnm1, Tor1b), localized within the common congenic interval shared by SP.WKYGla3d and SP.WKYGla3f strains, and one candidate gene for salt-induced PP variability and renal pathology (Rabgap1), located within the region unique to the SP.WKYGla3d strain. Comparison of next-generation sequencing data identified variants within additional positional genes that are likely to affect protein function.

Conclusion: This study has identified distinct intervals on RNO3-containing genes that may be important for blood pressure regulation and renal pathology during salt challenge.
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http://dx.doi.org/10.1097/HJH.0000000000001155DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5214373PMC
February 2017

Smooth Muscle Enriched Long Noncoding RNA (SMILR) Regulates Cell Proliferation.

Circulation 2016 May 6;133(21):2050-65. Epub 2016 Apr 6.

From BHF Glasgow Cardiovascular Research Centre, University of Glasgow, United Kingdom (M.D.B., R.D., L.D., R.M., R.G., P.W., N.S., M.W.N., R.A.M., A.H.B.); British Heart Foundation/University of Edinburgh Centre for Cardiovascular Science, Edinburgh, United Kingdom (M.D.B., K.P., A.T.V., N.J., M.R.D., D.E.N., R.A.M., A.H.B.); Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, The University of Glasgow, United Kingdom (G.H.); and Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, NY (J.M.M.).

Background: Phenotypic switching of vascular smooth muscle cells from a contractile to a synthetic state is implicated in diverse vascular pathologies, including atherogenesis, plaque stabilization, and neointimal hyperplasia. However, very little is known about the role of long noncoding RNA (lncRNA) during this process. Here, we investigated a role for lncRNAs in vascular smooth muscle cell biology and pathology.

Methods And Results: Using RNA sequencing, we identified >300 lncRNAs whose expression was altered in human saphenous vein vascular smooth muscle cells following stimulation with interleukin-1α and platelet-derived growth factor. We focused on a novel lncRNA (Ensembl: RP11-94A24.1), which we termed smooth muscle-induced lncRNA enhances replication (SMILR). Following stimulation, SMILR expression was increased in both the nucleus and cytoplasm, and was detected in conditioned media. Furthermore, knockdown of SMILR markedly reduced cell proliferation. Mechanistically, we noted that expression of genes proximal to SMILR was also altered by interleukin-1α/platelet-derived growth factor treatment, and HAS2 expression was reduced by SMILR knockdown. In human samples, we observed increased expression of SMILR in unstable atherosclerotic plaques and detected increased levels in plasma from patients with high plasma C-reactive protein.

Conclusions: These results identify SMILR as a driver of vascular smooth muscle cell proliferation and suggest that modulation of SMILR may be a novel therapeutic strategy to reduce vascular pathologies.
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http://dx.doi.org/10.1161/CIRCULATIONAHA.115.021019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4872641PMC
May 2016

Blood transcriptional signature of recombinant human erythropoietin administration and implications for antidoping strategies.

Physiol Genomics 2016 Mar 12;48(3):202-9. Epub 2016 Jan 12.

FIMS Reference Collaborating Centre of Sports Medicine for Anti-Doping Research, University of Brighton, Eastbourne, United Kingdom

Recombinant human erythropoietin (rHuEPO) is frequently abused by athletes as a performance-enhancing drug, despite being prohibited by the World Anti-Doping Agency. Although the methods to detect blood doping, including rHuEPO injections, have improved in recent years, they remain imperfect. In a proof-of-principle study, we identified, replicated, and validated the whole blood transcriptional signature of rHuEPO in endurance-trained Caucasian males at sea level (n = 18) and Kenyan endurance runners at moderate altitude (n = 20), all of whom received rHuEPO injections for 4 wk. Transcriptional profiling shows that hundreds of transcripts were altered by rHuEPO in both cohorts. The main regulated expression pattern, observed in all participants, was characterized by a "rebound" effect with a profound upregulation during rHuEPO and a subsequent downregulation up to 4 wk postadministration. The functions of the identified genes were mainly related to the functional and structural properties of the red blood cell. Of the genes identified to be differentially expressed during and post-rHuEPO, we further confirmed a whole blood 34-transcript signature that can distinguish between samples collected pre-, during, and post-rHuEPO administration. By providing biomarkers that can reveal rHuEPO use, our findings represent an advance in the development of new methods for the detection of blood doping.
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http://dx.doi.org/10.1152/physiolgenomics.00108.2015DOI Listing
March 2016

Differential expression of microRNA-206 and its target genes in preeclampsia.

J Hypertens 2015 Oct;33(10):2068-74

aInstitute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK bKazan Federal University, Kazan, Russian Federation *Christine Akehurst and Heather Y. Small contributed equally to this work.

Objectives: Preeclampsia is a multisystem disease that significantly contributes to maternal and foetal morbidity and mortality. In this study, we used a nonbiased microarray approach to identify novel circulating miRNAs in maternal plasma that may be associated with preeclampsia.

Methods: Plasma samples were obtained at 16 and 28 weeks of gestation from 18 women who later developed preeclampsia (cases) and 18 matched women with normotensive pregnancies (controls). We studied miRNA expression profiles in plasma and subsequently confirmed miRNA and target gene expression in placenta samples. Placental samples were obtained from an independent cohort of 19 women with preeclampsia matched with 19 women with normotensive pregnancies.

Results: From the microarray, we identified one miRNA that was significantly differentially expressed between cases and controls at 16 weeks of gestation and six miRNAs that were significantly differentially expressed at 28 weeks. Following qPCR validation, only one miR-206 was found to be significantly increased in 28-week samples in women who later developed preeclampsia (1.4-fold change ± 0.2). The trend for increase in miR-206 expression was mirrored within placental tissue from women with preeclampsia. In parallel, IGF-1, a target gene of miR-206, was also found to be downregulated (0.41 ± 0.04) in placental tissue from women with preeclampsia. miR-206 expression was also detectable in myometrium tissue and trophoblast cell lines.

Conclusion: Our pilot study has identified miRNA-206 as a novel factor upregulated in preeclampsia within the maternal circulation and in placental tissue.
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http://dx.doi.org/10.1097/HJH.0000000000000656DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4570688PMC
October 2015

Reducing In-Stent Restenosis: Therapeutic Manipulation of miRNA in Vascular Remodeling and Inflammation.

J Am Coll Cardiol 2015 Jun;65(21):2314-27

Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland. Electronic address:

Background: Drug-eluting stents reduce the incidence of in-stent restenosis, but they result in delayed arterial healing and are associated with a chronic inflammatory response and hypersensitivity reactions. Identifying novel interventions to enhance wound healing and reduce the inflammatory response may improve long-term clinical outcomes. Micro-ribonucleic acids (miRNAs) are noncoding small ribonucleic acids that play a prominent role in the initiation and resolution of inflammation after vascular injury.

Objectives: This study sought to identify miRNA regulation and function after implantation of bare-metal and drug-eluting stents.

Methods: Pig, mouse, and in vitro models were used to investigate the role of miRNA in in-stent restenosis.

Results: We documented a subset of inflammatory miRNAs activated after stenting in pigs, including the miR-21 stem loop miRNAs. Genetic ablation of the miR-21 stem loop attenuated neointimal formation in mice post-stenting. This occurred via enhanced levels of anti-inflammatory M2 macrophages coupled with an impaired sensitivity of smooth muscle cells to respond to vascular activation.

Conclusions: MiR-21 plays a prominent role in promoting vascular inflammation and remodeling after stent injury. MiRNA-mediated modulation of the inflammatory response post-stenting may have therapeutic potential to accelerate wound healing and enhance the clinical efficacy of stenting.
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http://dx.doi.org/10.1016/j.jacc.2015.03.549DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4444526PMC
June 2015

Identification of a common molecular pathway in hypertensive renal damage: comparison of rat and human gene expression profiles.

J Hypertens 2015 Mar;33(3):584-96; discussion 596

aRenal Research Group, Department of Clinical Medicine bDepartment of Biomedicine, University of Bergen cDepartment of Pathology, Haukeland University Hospital, Bergen, Norway dInstitute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK eDepartment of Medicine, Haukeland University Hospital, Bergen, Norway fIntegrative Physiology, Department of Medical Cell Biology gAnaesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden *Deceased. †Martin W. McBride and Michael Hultström are co-senior authors.

Background: There is a common structural progression in hypertensive renal damage with early arterial damage and fibrosis in the juxtamedullary cortex.

Method: The present investigation identifies a common pathway using three-gene expression profiles from hypertensive rat models: 60-week-old spontaneously hypertensive rat (SHR), salt-loaded stroke-prone SHR (SHRSP), and the non-clipped kidney after 24 weeks of two-kidney, one-clip hypertension (2K1C). Kidney damage was scored using a specialized system. Gene-expression profiles were determined using microarrays and validated using a panel of 47 genes by quantitative real-time PCR.

Results: All groups showed kidney damage (SHRs: 0.32 ± 0.09 vs. Wistar-Kyoto rats: 0.06 ± 0.03; 2K1C: 0.27 ± 0.13 vs. pooled controls: 0.01 ± 0.01; SHRSP: 1.13 ± 0.14 vs. WKY: 0.04 ± 0.03; all P < 0.05). A total of 1614 genes were changed in the SHR experiment, 1323 in the SHRSP, and 576 in the 2K1C. Eighty-eight genes were similarly regulated in all three models. Gene ontology enrichment analysis identified 59 ontologies that were enriched in all three datasets. These included over-representation to extracellular matrix, response to oxidative stress, and immune system processes. Out of the 88 in-common genes, 40 could be connected in a common pathway that was compared to two gene-expression profiles from human kidneys with histologically verified fibrosis to identify a highly significant number of in-common genes that were also represented in the common genetic pathway.

Conclusion: There is a common pathway during the development of hypertensive kidney damage in rats irrespective of model. Interestingly, large parts of this common pathway are conserved in human kidney damage, which may indicate a broader importance in the development of chronic kidney disease.
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http://dx.doi.org/10.1097/HJH.0000000000000395DOI Listing
March 2015

Origin of the Y chromosome influences intrarenal vascular responsiveness to angiotensin I and angiotensin (1-7) in stroke-prone spontaneously hypertensive rats.

Hypertension 2014 Dec 8;64(6):1376-83. Epub 2014 Sep 8.

From the Director's Research Group (A.K.S., G.L.J.), Department of Vascular Pharmacology (A.K.S., K.L.A., J.P.F.C.-D.), Department of Neuropharmacology (G.A.H.), and Department of Diabetic Complications (M.C.T.), Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (D.G., M.W.M., A.F.D.).

The lineage of the Y chromosome accounts for up to 15 to 20 mm Hg in arterial pressure. Genes located on the Y chromosome from the spontaneously hypertensive rat (SHR) are associated with the renin-angiotensin system. Given the important role of the renin-angiotensin system in the renal regulation of fluid homeostasis and arterial pressure, we hypothesized that the origin of the Y chromosome influences arterial pressure via interaction between the intrarenal vasculature and the renin-angiotensin system. Sixteen-week-old normotensive rats (Wistar Kyoto [WKY]), spontaneously hypertensive stroke-prone rat (SHRSP), and 2 reciprocal Y consomic rat strains, 1 comprising the WKY autosomes and X chromosome with the Y chromosome from the hypertensive rat strain (WKY.SPGlaY) and vice versa (SP.WKYGlaY), were examined. SP.WKYGlaY had lower systolic blood pressure than SHRSP (195±5 versus 227±8 mm Hg; P<0.03), whereas WKY.SPGlaY had higher systolic blood pressure compared with WKY (157±3 versus 148±3 mm Hg; P<0.05), measured by radiotelemetry. Compared with WKY rats, SHRSP had higher plasma angiotensin(1-7) (Ang (1-7)):Ang II ratio (WKY: 0.13±0.01 versus SHRSP: 1.33±0.4; P<0.005), greater angiotensin II receptor type 2 and Mas receptor mRNA expression, and a blunted renal constrictor response to intrarenal Ang I and Ang(1-7) infusions. Introgression of the normotensive Y chromosome into the SHRSP background (SP.WKYGlaY) restored responses in the SHRSP to WKY levels, evidenced by a reduction in plasma Ang(1-7):Ang II ratio (SP.WKYGlaY: 0.24±0.02; P<0.01), angiotensin II receptor type 2, and Mas receptor mRNA expression and an increased vasoconstrictor response to intrarenal Ang I and Ang(1-7) infusion. This study demonstrates that the origin of the Y chromosome significantly impacts the renal vascular responsiveness and therefore may influence the long-term renal regulation of blood pressure.
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http://dx.doi.org/10.1161/HYPERTENSIONAHA.114.03756DOI Listing
December 2014

Introgressed chromosome 2 quantitative trait loci restores aldosterone regulation and reduces response to salt in the stroke-prone spontaneously hypertensive rat.

J Hypertens 2014 Oct;32(10):2013-21; discussion 2021

aInstitute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow bEndocrinology Unit, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh cDietetics, Nutrition and Biological Sciences, Queen Margaret University, Edinburgh, Scotland, UK dEuropean Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre, Groningen, the Netherlands *Martin W. Mcbride and Anna F. Dominiczak are joint senior authors.

Background: The genetic contribution to salt-sensitivity in hypertension remains unclear. We have previously identified a quantitative trait locus on chromosome 2 in stroke-prone spontaneously hypertensive rats (SHRSPs) responsible for an increase in SBP in response to a salt challenge. This response is blunted in the congenic SHRSP strain with the Wistar-Kyoto (WKY) chromosome 2 region (10 cM) introgressed (SP.WKYGla2k). We aimed to discover the mechanisms that underlie the effects of this region on salt-handling in the SHRSP strain.

Method: Renal and adreno-cortical function were compared in the WKY, SHRSP and the congenic SP.WKYGla2k strains.

Results: In response to the salt challenge, all strains excreted more sodium, but the SHRSP strain excreted more protein and a greater amount of sodium compared with either the WKY or the SP.WKYGla2k strain (0.19 ± 0.02 vs. 0.12 ± 0.01 g/24 h and 0.09 ± 0.02 g/24 h, respectively). Glomerular filtration was not affected by diet or genotype, but renal plasma flow was decreased in the SP.WKYGla2k and SHRSP strains. The SHRSP strain had higher plasma aldosterone in association with greater adrenal CYP11B2 (aldosterone synthase) and 3β hydroxysteroid dehydrogenase mRNA gene expression when compared to the WKY strain. Strikingly, introgression of the WKY chromosome 2 region into the SHRSP strain corrected the proteinuria and reduced sodium excretion, plasma aldosterone levels and 3β hydroxysteroid dehydrogenase mRNA gene expression in response to the salt challenge when compared to the SHRSP strain. Glucocorticoid levels and markers of glucocorticoid synthesis were unaffected.

Conclusion: Our findings suggest that introgression of the chromosome 2 congenic interval from the WKY into the SHRSP strain is associated with restored aldosterone regulation sufficient to reduce salt-sensitive hypertension and proteinuria.
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http://dx.doi.org/10.1097/HJH.0000000000000300DOI Listing
October 2014

Differential gene expression in multiple neurological, inflammatory and connective tissue pathways in a spontaneous model of human small vessel stroke.

Neuropathol Appl Neurobiol 2014 Dec;40(7):855-72

Centre for Clinical Brain Sciences, University of Edinburgh, Western General Hospital, Edinburgh; Department of Bioengineering, Imperial College London, London.

Aims: Cerebral small vessel disease (SVD) causes a fifth of all strokes plus diffuse brain damage leading to cognitive decline, physical disabilities and dementia. The aetiology and pathogenesis of SVD are unknown, but largely attributed to hypertension or microatheroma.

Methods: We used the spontaneously hypertensive stroke-prone rat (SHRSP), the closest spontaneous experimental model of human SVD, and age-matched control rats kept under identical, non-salt-loaded conditions, to perform a blinded analysis of mRNA microarray, qRT-PCR and pathway analysis in two brain regions (frontal and mid-coronal) commonly affected by SVD in the SHRSP at age five, 16 and 21 weeks.

Results: We found gene expression abnormalities, with fold changes ranging from 2.5 to 59 for the 10 most differentially expressed genes, related to endothelial tight junctions (reduced), nitric oxide bioavailability (reduced), myelination (impaired), glial and microglial activity (increased), matrix proteins (impaired), vascular reactivity (impaired) and albumin (reduced), consistent with protein expression defects in the same rats. All were present at age 5 weeks thus predating blood pressure elevation. 'Neurological' and 'inflammatory' pathways were more affected than 'vascular' functional pathways.

Conclusions: This set of defects, although individually modest, when acting in combination could explain the SHRSP's susceptibility to microvascular and brain injury, compared with control rats. Similar combined, individually modest, but multiple neurovascular unit defects, could explain susceptibility to spontaneous human SVD.
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http://dx.doi.org/10.1111/nan.12116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4260148PMC
December 2014

Validation of uromodulin as a candidate gene for human essential hypertension.

Hypertension 2014 Mar 9;63(3):551-8. Epub 2013 Dec 9.

Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, 126 University Place, Glasgow G12 8TA, United Kingdom.

A recent genome-wide association study identified a locus on chromosome 16 in the promoter region of the uromodulin (UMOD) gene that is associated with hypertension. Here, we examined the hypertension signal with functional studies in Umod knockout (KO) mice. Systolic blood pressure was significantly lower in KO versus wild-type (WT) mice under basal conditions (KO: 116.6±0.3 mm Hg versus WT: 136.2±0.4 mm Hg; P<0.0001). Administration of 2% NaCl did not alter systolic blood pressure in KO mice, whereas it increased in WT mice by ≈33%, P<0.001. The average 24-hour urinary sodium excretion in the KO was greater than that of WT mice (P<0.001). Chronic renal function curves demonstrate a leftward shift in KO mice, suggesting that the relationship between UMOD and blood pressure is affected by sodium. Creatinine clearance was increased during salt loading with 2% NaCl in the KO mice, leading to augmented filtered Na(+) excretion and further Na(+) loss. The difference in sodium uptake that exists between WT and KO strains was explored at the molecular level. Urinary tumor necrosis factor-α levels were significantly higher in KO mice compared with WT mice (P<0.0001). Stimulation of primary thick ascending limb of the loop of Henle cells with exogenous tumor necrosis factor-α caused a reduction in NKCC2A expression (P<0.001) with a concurrent rise in the levels of UMOD mRNA (P<0.001). Collectively, we demonstrate that UMOD regulates sodium uptake in the thick ascending limb of the loop of Henle by modulating the effect of tumor necrosis factor-α on NKCC2A expression, making UMOD an important determinant of blood pressure control.
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http://dx.doi.org/10.1161/HYPERTENSIONAHA.113.01423DOI Listing
March 2014

Combined sequence-based and genetic mapping analysis of complex traits in outbred rats.

Nat Genet 2013 Jul 26;45(7):767-75. Epub 2013 May 26.

Wellcome Trust Centre for Human Genetics, Oxford, UK.

Genetic mapping on fully sequenced individuals is transforming understanding of the relationship between molecular variation and variation in complex traits. Here we report a combined sequence and genetic mapping analysis in outbred rats that maps 355 quantitative trait loci for 122 phenotypes. We identify 35 causal genes involved in 31 phenotypes, implicating new genes in models of anxiety, heart disease and multiple sclerosis. The relationship between sequence and genetic variation is unexpectedly complex: at approximately 40% of quantitative trait loci, a single sequence variant cannot account for the phenotypic effect. Using comparable sequence and mapping data from mice, we show that the extent and spatial pattern of variation in inbred rats differ substantially from those of inbred mice and that the genetic variants in orthologous genes rarely contribute to the same phenotype in both species.
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http://dx.doi.org/10.1038/ng.2644DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3821058PMC
July 2013

Interaction between chromosome 2 and 3 regulates pulse pressure in the stroke-prone spontaneously hypertensive rat.

Hypertension 2013 Jul 6;62(1):33-40. Epub 2013 May 6.

Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, United Kingdom.

In an F2 cross between stroke-prone spontaneously hypertensive (SHRSP) and Wistar Kyoto (WKY) rats, we previously identified blood pressure quantitative trait loci (QTL) on rat chromosome (RNO) 2 and a pulse pressure QTL on RNO3. The aims of this study were to confirm the QTL on RNO3 and to investigate interaction between RNO2 and RNO3 loci through the generation and phenotypic assessment of single RNO3 congenic (SP.WKY(Gla)3a) and bicongenic (SP.WKY(Gla)2a/3a) strains. Hemodynamic profiling, vascular function, and renal histology were examined in these newly generated strains along with the previously reported RNO2 congenic strain (SP.WKY(Gla)2a). Our results demonstrate significant equivalent reduction in systolic, diastolic, and pulse pressure phenotypes in SP.WKY(Gla)3a and SP.WKY(Gla)2a rats, whereas greater reductions were observed with the SP.WKY(Gla)2a/3a bicongenic strain achieving blood pressure levels similar to normotensive WKY rats. Epistasis was observed between pulse pressure QTL on RNO2 and 3 at baseline and during 1% salt challenge. Vascular function and renal pathology studies indicate that QTL on RNO3 are responsible for salt-induced kidney pathology, whereas QTL on RNO2 seem to have greater impact on vascular function. RNO3 congenic and bicongenic strains have confirmed the importance of SHRSP alleles in the RNO3 congenic interval on pulse pressure variability and end-organ damage. These strains will allow interrogation of complex gene-gene and gene-environment interactions contributing to salt-sensitive hypertension and renal pathology in the SHRSP rat.
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http://dx.doi.org/10.1161/HYPERTENSIONAHA.111.00814DOI Listing
July 2013

Profiling of transcriptional and epigenetic changes during directed endothelial differentiation of human embryonic stem cells identifies FOXA2 as a marker of early mesoderm commitment.

Stem Cell Res Ther 2013 Apr 24;4(2):36. Epub 2013 Apr 24.

Introduction: Differentiation of vascular endothelial cells (ECs) in clinically relevant numbers for injection into ischaemic areas could offer therapeutic potential in the treatment of cardiovascular conditions, including myocardial infarction, peripheral vascular disease and stroke. While we and others have demonstrated successful generation of functional endothelial-like cells from human embryonic stem cells (hESCs), little is understood regarding the complex transcriptional and epigenetic changes that occur during differentiation, in particular during early commitment to a mesodermal lineage.

Methods: We performed the first gene expression microarray study of hESCs undergoing directed differentiation to ECs using a monolayer-based, feeder-free and serum-free protocol. Microarray results were confirmed by quantitative RT-PCR and immunocytochemistry, and chromatin immunoprecipitation (ChIP)-PCR analysis was utilised to determine the bivalent status of differentially expressed genes.

Results: We identified 22 transcription factors specific to early mesoderm commitment. Among these factors, FOXA2 was observed to be the most significantly differentially expressed at the hESC-EC day 2 timepoint. ChIP-PCR analysis revealed that the FOXA2 transcription start site is bivalently marked with histone modifications for both gene activation (H3K4me3) and repression (H3K27me3) in hESCs, suggesting the transcription factor may be a key regulator of hESC differentiation.

Conclusion: This enhanced knowledge of the lineage commitment process will help improve the design of directed differentiation protocols, increasing the yield of endothelial-like cells for regenerative medicine therapies in cardiovascular disease.
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http://dx.doi.org/10.1186/scrt192DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3706826PMC
April 2013

Functional duality of astrocytes in myelination.

J Neurosci 2011 Sep;31(37):13028-38

Glasgow Biomedical Research Centre, Institute of Infection, Immunity, and Inflammation, University of Glasgow, Glasgow G12 8TA, United Kingdom.

Astrocytes undergo major phenotypic changes in response to injury and disease that directly influence repair in the CNS, but the mechanisms involved are poorly understood. Previously, we have shown that neurosphere-derived rat astrocytes plated on poly-L-lysine (PLL-astrocytes) support myelination in dissociated rat spinal cord cultures (myelinating cultures). It is hypothesized that astrocyte reactivity can affect myelination, so we have exploited this culture system to ascertain how two distinct astrocyte phenotypes influence myelination. Astrocytes plated on tenascin C (TnC-astrocytes), a method to induce quiescence, resulted in less myelinated fibers in the myelinating cultures when compared with PLL-astrocytes. In contrast, treatment of myelinating cultures plated on PLL-astrocytes with ciliary neurotrophic factor (CNTF), a cytokine known to induce an activated astrocyte phenotype, promoted myelination. CNTF could also reverse the effect of quiescent astrocytes on myelination. A combination of microarray gene expression analysis and quantitative real-time PCR identified CXCL10 as a potential candidate for the reduction in myelination in cultures on TnC-astrocytes. The effect of TnC-astrocytes on myelination was eliminated by neutralizing CXCL10 antibodies. Conversely, CXCL10 protein inhibited myelination on PLL-astrocytes. Furthermore, CXCL10 treatment of purified oligodendrocyte precursor cells did not affect proliferation, differentiation, or process extension compared with untreated controls, suggesting a role in glial/axonal ensheathment. These data demonstrate a direct correlation of astrocyte phenotypes with their ability to support myelination. This observation has important implications with respect to the development of therapeutic strategies to promote CNS remyelination in demyelinating diseases.
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http://dx.doi.org/10.1523/JNEUROSCI.1449-11.2011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6623277PMC
September 2011

miR-21 and miR-214 are consistently modulated during renal injury in rodent models.

Am J Pathol 2011 Aug 31;179(2):661-72. Epub 2011 May 31.

BHF Glasgow Cardiovascular Research Centre, Glasgow, United Kingdom.

Transforming growth factor (TGF)-β is one of the main fibrogenic cytokines that drives the pathophysiology of progressive renal scarring. MicroRNAs (miRNAs) are endogenous non-coding RNAs that post-transcriptionally regulate gene expression. We examined the role of TGF-β-induced expression of miR-21, miRNAs in cell culture models and miRNA expression in relevant models of renal disease. In vitro, TGF-β changed expression of miR-21, miR-214, and miR-145 in rat mesangial cells (CRL-2753) and miR-214, miR-21, miR-30c, miR-200b, and miR-200c during induction of epithelial-mesenchymal transition in rat tubular epithelial cells (NRK52E). miR-214 expression was robustly modulated in both cell types, whereas in tubular epithelial cells miR-21 was increased and miR-200b and miR-200c were decreased by 58% and 48%, respectively, in response to TGF-β. TGF-β receptor-1 was found to be a target of miR-200b/c and was down-regulated after overexpression of miR-200c. To assess the differential expression of these miRNAs in vivo, we used the anti-Thy1.1 mesangial glomerulonephritis model and the unilateral ureteral obstruction model in which TGF-β plays a role and also a genetic model of hypertension, the stroke-prone spontaneously hypertensive rat with and without salt loading. The expressions of miR-214 and miR-21 were significantly increased in all in vivo models, showing a possible miRNA signature of renal damage despite differing causes.
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http://dx.doi.org/10.1016/j.ajpath.2011.04.021DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3157202PMC
August 2011

Predictive response-relevant clustering of expression data provides insights into disease processes.

Nucleic Acids Res 2010 Nov 22;38(20):6831-40. Epub 2010 Jun 22.

Inference Group, Department of Computing Science, University of Glasgow, and Gartnavel General Hospital, 1053 Great Western Road, Glasgow G12 0YN, UK.

This article describes and illustrates a novel method of microarray data analysis that couples model-based clustering and binary classification to form clusters of `response-relevant' genes; that is, genes that are informative when discriminating between the different values of the response. Predictions are subsequently made using an appropriate statistical summary of each gene cluster, which we call the `meta-covariate' representation of the cluster, in a probit regression model. We first illustrate this method by analysing a leukaemia expression dataset, before focusing closely on the meta-covariate analysis of a renal gene expression dataset in a rat model of salt-sensitive hypertension. We explore the biological insights provided by our analysis of these data. In particular, we identify a highly influential cluster of 13 genes--including three transcription factors (Arntl, Bhlhe41 and Npas2)-that is implicated as being protective against hypertension in response to increased dietary sodium. Functional and canonical pathway analysis of this cluster using Ingenuity Pathway Analysis implicated transcriptional activation and circadian rhythm signalling, respectively. Although we illustrate our method using only expression data, the method is applicable to any high-dimensional datasets. Expression data are available at ArrayExpress (accession number E-MEXP-2514) and code is available at http://www.dcs.gla.ac.uk/inference/metacovariateanalysis/.
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http://dx.doi.org/10.1093/nar/gkq550DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2978340PMC
November 2010

Gene expression profiling in whole blood of patients with coronary artery disease.

Clin Sci (Lond) 2010 Jul 9;119(8):335-43. Epub 2010 Jul 9.

BHF Glasgow Cardiovascular Research Centre, University of Glasgow, UK.

Owing to the dynamic nature of the transcriptome, gene expression profiling is a promising tool for discovery of disease-related genes and biological pathways. In the present study, we examined gene expression in whole blood of 12 patients with CAD (coronary artery disease) and 12 healthy control subjects. Furthermore, ten patients with CAD underwent whole-blood gene expression analysis before and after the completion of a cardiac rehabilitation programme following surgical coronary revascularization. mRNA and miRNA (microRNA) were isolated for expression profiling. Gene expression analysis identified 365 differentially expressed genes in patients with CAD compared with healthy controls (175 up- and 190 down-regulated in CAD), and 645 in CAD rehabilitation patients (196 up- and 449 down-regulated post-rehabilitation). Biological pathway analysis identified a number of canonical pathways, including oxidative phosphorylation and mitochondrial function, as being significantly and consistently modulated across the groups. Analysis of miRNA expression revealed a number of differentially expressed miRNAs, including hsa-miR-140-3p (control compared with CAD, P=0.017), hsa-miR-182 (control compared with CAD, P=0.093), hsa-miR-92a and hsa-miR-92b (post- compared with pre-exercise, P<0.01). Global analysis of predicted miRNA targets found significantly reduced expression of genes with target regions compared with those without: hsa-miR-140-3p (P=0.002), hsa-miR-182 (P=0.001), hsa-miR-92a and hsa-miR-92b (P=2.2x10-16). In conclusion, using whole blood as a 'surrogate tissue' in patients with CAD, we have identified differentially expressed miRNAs, differentially regulated genes and modulated pathways which warrant further investigation in the setting of cardiovascular function. This approach may represent a novel non-invasive strategy to unravel potentially modifiable pathways and possible therapeutic targets in cardiovascular disease.
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http://dx.doi.org/10.1042/CS20100043DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2922838PMC
July 2010

Dysregulation of cadherins in the intercalated disc of the spontaneously hypertensive stroke-prone rat.

J Mol Cell Cardiol 2010 Jun 6;48(6):1121-8. Epub 2010 Feb 6.

BHF Glasgow Cardiovascular Research Centre, University of Glasgow, 126 University place, Glasgow, G12 8TA, UK.

The structural integrity of cardiac cells is maintained by the Ca(2+)-dependent homophilic cell-cell adhesion of cadherins. N-cadherin is responsible for this adhesion under normal physiological conditions. The role of cadherins in adverse cardiac pathology is less clear. We studied the hearts of the stroke-prone spontaneously hypertensive (SHRSP) rat as a genetic model of cardiac hypertrophy and compared them to Wistar-Kyoto control animals. Western blotting of protein homogenates from 12-week old SHRSP animals indicated that similar levels of beta, gamma-, and alpha-catenin and T, N and R-cadherin were expressed in the control and SHRSP animals. However, dramatically higher levels of E-cadherin were detected in SHRSP animals compared to controls at 6, 12 and 18 weeks of age. This was confirmed by quantitative Taqman PCR and immunohistochemistry. E-cadherin was located at the intercalated disc of the myocytes in co-localisation with connexin 43. Adenoviral overexpression of E-cadherin in rat H9c2 cells and primary rabbit myocytes resulted in a significant reduction in myocyte cell diameter and breadth. E-cadherin overexpression resulted in re-localisation of beta-catenin to the cell surface particularly to cell-cell junctions. Subsequent immunohistochemistry of the hearts of WKY and SHRSP animals also revealed increased levels of beta-catenin in the intercalated disc in the SHRSP compared to WKY. Therefore, remodelling of the intercalated disc in the hearts of SHRSP animals may contribute to the altered function observed in these animals.
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http://dx.doi.org/10.1016/j.yjmcc.2010.01.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867785PMC
June 2010

Genetics of hypertension: from experimental animals to humans.

Biochim Biophys Acta 2010 Dec 24;1802(12):1299-308. Epub 2009 Dec 24.

BHF Glasgow Cardiovascular Research Centre, University of Glasgow, UK.

Essential hypertension affects 20 to 30% of the population worldwide and contributes significantly to cardiovascular mortality and morbidity. Heridability of blood pressure is around 15 to 40% but there are also substantial environmental factors affecting blood pressure variability. It is assumed that blood pressure is under the control of a large number of genes each of which has only relatively mild effects. It has therefore been difficult to discover the genes that contribute to blood pressure variation using traditional approaches including candidate gene studies and linkage studies. Animal models of hypertension, particularly in the rat, have led to the discovery of quantitative trait loci harbouring one or several hypertension related genes, but translation of these findings into human essential hypertension remains challenging. Recent development of genotyping technology made large scale genome-wide association studies possible. This approach and the study of monogenic forms of hypertension has led to the discovery of novel and robust candidate genes for human essential hypertension, many of which require functional analysis in experimental models.
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http://dx.doi.org/10.1016/j.bbadis.2009.12.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2977068PMC
December 2010

Renal and vascular glutathione S-transferase mu is not affected by pharmacological intervention to reduce systolic blood pressure.

J Hypertens 2009 Aug;27(8):1575-84

Division of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow G12 8TA, UK.

Background: Our previous studies demonstrated reduced rat glutathione S-transferase mu type 1 (Gstm1) expression in stroke-prone spontaneously hypertensive rats (SHRSPs), when compared with the normotensive Wistar-Kyoto rat.

Methods: This study investigated the effects of angiotensin II type 1 receptor blocker (ARB) and a diuretic/vasodilator combination on the expression levels of rat Gstm1 and other Gstm isoforms.

Results: Antihypertensive treatments of young and mature SHRSPs with an ARB and a diuretic/vasodilator combination improved SBP but did not affect the expression levels of Gstm1. Although Gstm1 is a member of a family of highly homologous genes, with the exception of Gstm2, there was no evidence for compensatory increase in expression of other Gstm isoforms. In contrast, we observed reduced expression of several other Gstm isoforms in untreated SHRSPs. Untreated SHRSPs demonstrated increased renal and vascular oxidative stress, both of which were not significantly affected by the antihypertensive treatments. Untreated SHRSPs scored significantly higher when assessed for renal histopathological damage, and this was improved by antihypertensive treatments.

Conclusion: These results suggest that reduced Gstm1 expression in SHRSPs is due to strain-dependent genetic abnormalities, playing a causative role in the development of hypertension, probably through oxidative stress pathway. Renal changes occur as a consequence of increased blood pressure and can be improved when treated with antihypertensive drugs. In silico comparative genome analysis combined with expression studies in rat and human vascular tissue revealed that there are possible four human homologues (GSTM1, GSTM2, GSTM4 and GSTM5) for rat Gstm1.
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http://dx.doi.org/10.1097/HJH.0b013e32832cc5a1DOI Listing
August 2009

The genetics of cardiovascular disease.

Trends Endocrinol Metab 2008 Nov 24;19(9):309-16. Epub 2008 Sep 24.

BHF Glasgow Cardiovascular Research Centre, Faculty of Medicine, University of Glasgow, 126 University Place, Glasgow, G12 8TA, UK.

Recent advances in genotyping technology and insights into disease mechanisms have increased interest in the genetics of cardiovascular disease. Several candidate genes involved in cardiovascular diseases were identified from studies using animal models, and the translation of these findings to human disease is an exciting challenge. There is a trend towards large-scale genome-wide association studies that are subject to strict quality criteria with regard to both genotyping and phenotyping. Here, we review some of the strategies that have been developed to translate findings from experimental models to human disease and outline the need for optimizing global approaches to analyze such results. Findings from ongoing studies are interpreted in the context of disease pathways instead of the more traditional focus on single genetic variants.
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http://dx.doi.org/10.1016/j.tem.2008.07.010DOI Listing
November 2008

Glutathione S-transferase variants and hypertension.

J Hypertens 2008 Jul;26(7):1343-52

British Heart Foundation Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK.

Objectives: Glutathione S-transferases are involved in defences against oxidative stress. We have recently demonstrated reduced expression of glutathione S-transferase mu type 1 (Gstm1) in a rat model of hypertension. Here, we examine the association between GSTM variants and hypertension in human.

Methods: We screened 83 patients with hypertension and 46 controls for single nucleotide polymorphisms in GSTM genes by TaqMan single nucleotide polymorphism genotyping assays and DNA sequencing. We then genotyped 753 trios from the Medical Research Council British Genetics of Hypertension Study transmission disequilibrium test cohort for 10 single nucleotide polymorphisms and the GSTM1 deletion and examined renal GSTM expression in a cohort of 27 hypertensive and 18 normotensive subjects. Finally, we attempted to replicate our findings in 1675 cases and 1654 controls from the Medical Research Council British Genetics of Hypertension Study case-control cohort.

Results: We identified two major linkage disequilibrium blocks including GSTM4/GSTM2 and GSTM5/GSTM3 separated by the GSTM1 gene. In the British Genetics of Hypertension transmission disequilibrium test resource, a single nucleotide polymorphism in the 3' region of GSTM5 (rs11807) was found to be associated with hypertension (P = 0.01) with the T-allele being over-transmitted to hypertensive offspring. GSTM5 mRNA expression was found to be reduced in kidney tissue of subjects homozygous for the T-allele of rs11807 as compared to C-allele homozygous and CT heterozygous subjects (P = 0.02). Nevertheless, rs11807 was not associated with hypertension in the British Genetics of Hypertension case-control cohort (P = 0.61).

Conclusion: Our studies do not provide an evidence of an association of GSTM gene variants with hypertension in humans. They, however, illustrate the essential role of replication of initial results in a second cohort.
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http://dx.doi.org/10.1097/HJH.0b013e3282fe1d67DOI Listing
July 2008