Publications by authors named "Olga Sazonova"

27 Publications

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Genome-wide analysis of 944 133 individuals provides insights into the etiology of haemorrhoidal disease.

Gut 2021 Apr 22. Epub 2021 Apr 22.

Department of Medicine I, Institute of Cancer Research, Medical University Vienna, Vienna, Austria.

Objective: Haemorrhoidal disease (HEM) affects a large and silently suffering fraction of the population but its aetiology, including suspected genetic predisposition, is poorly understood. We report the first genome-wide association study (GWAS) meta-analysis to identify genetic risk factors for HEM to date.

Design: We conducted a GWAS meta-analysis of 218 920 patients with HEM and 725 213 controls of European ancestry. Using GWAS summary statistics, we performed multiple genetic correlation analyses between HEM and other traits as well as calculated HEM polygenic risk scores (PRS) and evaluated their translational potential in independent datasets. Using functional annotation of GWAS results, we identified HEM candidate genes, which differential expression and coexpression in HEM tissues were evaluated employing RNA-seq analyses. The localisation of expressed proteins at selected loci was investigated by immunohistochemistry.

Results: We demonstrate modest heritability and genetic correlation of HEM with several other diseases from the GI, neuroaffective and cardiovascular domains. HEM PRS validated in 180 435 individuals from independent datasets allowed the identification of those at risk and correlated with younger age of onset and recurrent surgery. We identified 102 independent HEM risk loci harbouring genes whose expression is enriched in blood vessels and GI tissues, and in pathways associated with smooth muscles, epithelial and endothelial development and morphogenesis. Network transcriptomic analyses highlighted HEM gene coexpression modules that are relevant to the development and integrity of the musculoskeletal and epidermal systems, and the organisation of the extracellular matrix.

Conclusion: HEM has a genetic component that predisposes to smooth muscle, epithelial and connective tissue dysfunction.
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http://dx.doi.org/10.1136/gutjnl-2020-323868DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8292596PMC
April 2021

The Risk of Type 2 Diabetes Mellitus in a Russian Population Cohort According to Data from the HAPIEE Project.

J Pers Med 2021 Feb 11;11(2). Epub 2021 Feb 11.

Institute of Internal and Preventive Medicine-Branch of Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630089 Novosibirsk, Russia.

The aim of this study is to investigate the 14-year risk of type 2 diabetes mellitus (T2DM) and develop a risk score for T2DM in the Siberian cohort. A random population sample (males/females, 45-69 years old) was examined at baseline in 2003-2005 (Health, Alcohol, and Psychosocial Factors in Eastern Europe (HAPIEE) project, = 9360, Novosibirsk) and re-examined in 2006-2008 and 2015-2017. After excluding those with baseline T2DM, the final analysis included 7739 participants. The risk of incident T2DM during a 14-year follow-up was analysed using Cox regression. In age-adjusted models, male and female hazard ratios (HR) of incident T2DM were 5.02 (95% CI 3.62; 6.96) and 5.13 (95% CI 3.56; 7.37) for BMI ≥ 25 kg/m; 4.38 (3.37; 5.69) and 4.70 (0.27; 6.75) for abdominal obesity (AO); 3.31 (2.65; 4.14) and 3.61 (3.06; 4.27) for fasting hyperglycaemia (FHG); 2.34 (1.58; 3.49) and 3.27 (2.50; 4.26) for high triglyceride (TG); 2.25 (1.74; 2.91) and 2.82 (2.27; 3.49) for hypertension (HT); and 1.57 (1.14; 2.16) and 1.69 (1.38; 2.07) for family history of diabetes mellitus (DM). In addition, secondary education, low physical activity (PA), and history of cardiovascular disease (CVD) were also significantly associated with T2DM in females. A simple T2DM risk calculator was generated based on non-laboratory parameters. A scale with the best quality included waist circumference >95 cm, HT history, and family history of T2DM (area under the curve (AUC) = 0.71). The proposed 10-year risk score of T2DM represents a simple, non-invasive, and reliable tool for identifying individuals at a high risk of future T2DM.
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http://dx.doi.org/10.3390/jpm11020119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916922PMC
February 2021

Unravelling actionable biology using transcriptomic data to integrate mitotic index and Ki-67 in the management of lung neuroendocrine tumors.

Oncotarget 2021 Feb 2;12(3):209-220. Epub 2021 Feb 2.

Quebec Heart and Lung Institute Research Center, Quebec City, QC G1V4G5, Canada.

Pulmonary neuroendocrine tumors (NETs) are a heterogeneous family of malignancies whose classification relies on morphology and mitotic rate, unlike extrapulmonary neuroendocrine tumors that require both mitotic rate and Ki-67. As mitotic count is proportional to Ki-67, it is crucial to understand if Ki-67 can complement the existing diagnostic guidelines, as well as discover the benefit of these two markers to unravel the biological heterogeneity. In this study, we investigated the association of mitotic rate and Ki-67 at gene- and pathway-level using transcriptomic data in lung NET malignancies. Lung resection tumor specimens obtained from 28 patients diagnosed with NETs were selected. Mitotic rate, Ki-67 and transcriptomic data were obtained for all samples. The concordance between mitotic rate and Ki-67 was evaluated at gene-level and pathway-level using gene expression data. Our analysis revealed a strong association between mitotic rate and Ki-67 across all samples and cell cycle genes were found to be differentially ranked between them. Pathway analysis indicated that a greater number of pathways overlapped between these markers. Analyses based on lung NET subtypes revealed that mitotic rate in carcinoids and Ki-67 in large cell neuroendocrine carcinomas provided comprehensive characterization of pathways among these malignancies. Among the two subtypes, we found distinct leading-edge gene sets that drive the enrichment signal of commonly enriched pathways between mitotic index and Ki-67. Overall, our findings delineated the degree of benefit of the two proliferation markers, and offers new layer to predict the biological behavior and identify high-risk patients using a more comprehensive diagnostic workup.
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http://dx.doi.org/10.18632/oncotarget.27874DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7869577PMC
February 2021

Transcriptomic data helps refining classification of pulmonary carcinoid tumors with increased mitotic counts.

Mod Pathol 2020 09 14;33(9):1712-1721. Epub 2020 Apr 14.

Quebec Heart and Lung Institute Research Center, Quebec City, QC, Canada.

Pulmonary neuroendocrine neoplasms are classified by WHO as either typical or atypical carcinoids, large cell (LCNEC) or small cell (SCLC) neuroendocrine carcinoma based on mitotic count, morphology, and necrosis assessment. LCNEC with low mitotic count and sharing morphologic features with carcinoids are in a gray zone for classification and their rare prevalence and the paucity of studies precludes proper validation of the current grading system. In this study, we aim to investigate their clinicopathological and transcriptomic profiles. Lung resection specimens obtained from 18 patients diagnosed with carcinoids or LCNEC were selected. Four of them were characterized as borderline tumors based on a mitotic rate ranging between 10 and 30 mitoses per 2 mm. Comprehensive morphological and immunohistochemical (IHC) evaluation was performed and tumor-based transcriptomic profiles were analyzed through unsupervised clustering. Clustering analysis revealed two distinct molecular groups characterized by low (C1) and high (C2) proliferation. C1 was comprised of seven carcinoids and three borderline tumors, while C2 was comprised of seven LCNEC and one borderline tumor. Furthermore, patients in cluster C1 had a better recurrence-free survival compared with patients in cluster C2 (20% vs 75%). Histological features, IHC profile, and molecular analysis showed that three out of four borderline tumors showed features consistent with carcinoids. Therefore, our findings convey that the current diagnostic guidelines are suboptimal for classification of pulmonary neuroendocrine tumors with increased proliferative index and carcinoid-like morphology. These results support the emerging concept that neuroendocrine tumors with carcinoid-like features and mitotic count of <20 mitoses per 2 mm should be regarded as pulmonary carcinoids instead of LCNEC.
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http://dx.doi.org/10.1038/s41379-020-0538-8DOI Listing
September 2020

Coronary artery fixation at iso-arterial pressure: impacts on histologic evaluation and clinical management.

Cardiovasc Pathol 2019 Nov - Dec;43:107141. Epub 2019 Jul 8.

Department of Pathology, Quebec Heart and Lung Institute, 2725 Chemin Sainte-FoyG1V 4G5 ,Quebec, Canada. Electronic address:

Coronary angiography is the standard imaging method for determining the site, extent, and severity of coronary artery disease. Several publications have reported discordance between the degree of coronary artery stenosis determined from post-mortem histologic evaluation and coronary angiography. While the 2-dimensional limitations of coronary angiography are well established, the determination of coronary stenosis based on histologic evaluation of passively fixed samples is also associated with significant biases. In this study, we used patients with chronic coronary artery disease to compare the stenosis severity estimates that were determined using the passive fixation method with those determined using the active fixation method. Our results showed a significant discrepancy between the stenosis in passively fixed coronary arteries when compared with coronary angiography in all major coronary vessels combined (P=.002), and in Cx (P=.045) and CD (P=.026). However, there was no mean difference when compared with perfused (actively fixed) samples when all vessels were combined or examined individually. Iso-physiologic mechanical perfusion (active) fixation yielded significantly reduced coronary artery stenosis means when compared to the passive fixation method in post-mortem evaluations during autopsies. This was evident when all vessels were combined (P=.0001) and assessed individually (Cx (P=.003), LAD (P=.025), LM (P=.056) and RC (P=.007)). Autopsies including cardiac explant patients also showed differences in estimates for all vessels combined (P=.0001) and in Cx (P=.016) and RC (P=.006). In summary, our quantitative histopathology analyses using perfused coronary artery stenosis at physiologic pressure showed significant discrepancies when compared with passive histopathology.
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http://dx.doi.org/10.1016/j.carpath.2019.06.005DOI Listing
February 2020

Placenta and appetite genes GDF15 and IGFBP7 are associated with hyperemesis gravidarum.

Nat Commun 2018 03 21;9(1):1178. Epub 2018 Mar 21.

Department of Maternal-Fetal Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.

Hyperemesis gravidarum (HG), severe nausea and vomiting of pregnancy, occurs in 0.3-2% of pregnancies and is associated with maternal and fetal morbidity. The cause of HG remains unknown, but familial aggregation and results of twin studies suggest that understanding the genetic contribution is essential for comprehending the disease etiology. Here, we conduct a genome-wide association study (GWAS) for binary (HG) and ordinal (severity of nausea and vomiting) phenotypes of pregnancy complications. Two loci, chr19p13.11 and chr4q12, are genome-wide significant (p < 5 × 10) in both association scans and are replicated in an independent cohort. The genes implicated at these two loci are GDF15 and IGFBP7 respectively, both known to be involved in placentation, appetite, and cachexia. While proving the casual roles of GDF15 and IGFBP7 in nausea and vomiting of pregnancy requires further study, this GWAS provides insights into the genetic risk factors contributing to the disease.
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http://dx.doi.org/10.1038/s41467-018-03258-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5862842PMC
March 2018

TCF21 and the environmental sensor aryl-hydrocarbon receptor cooperate to activate a pro-inflammatory gene expression program in coronary artery smooth muscle cells.

PLoS Genet 2017 May 8;13(5):e1006750. Epub 2017 May 8.

Division of Cardiovascular Medicine, Stanford University, Stanford, California, United States of America.

Both environmental factors and genetic loci have been associated with coronary artery disease (CAD), however gene-gene and gene-environment interactions that might identify molecular mechanisms of risk are not easily studied by human genetic approaches. We have previously identified the transcription factor TCF21 as the causal CAD gene at 6q23.2 and characterized its downstream transcriptional network that is enriched for CAD GWAS genes. Here we investigate the hypothesis that TCF21 interacts with a downstream target gene, the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor that mediates the cellular response to environmental contaminants, including dioxin and polycyclic aromatic hydrocarbons (e.g., tobacco smoke). Perturbation of TCF21 expression in human coronary artery smooth muscle cells (HCASMC) revealed that TCF21 promotes expression of AHR, its heterodimerization partner ARNT, and cooperates with these factors to upregulate a number of inflammatory downstream disease related genes including IL1A, MMP1, and CYP1A1. TCF21 was shown to bind in AHR, ARNT and downstream target gene loci, and co-localization was noted for AHR-ARNT and TCF21 binding sites genome-wide in regions of HCASMC open chromatin. These regions of co-localization were found to be enriched for GWAS signals associated with cardio-metabolic as well as chronic inflammatory disease phenotypes. Finally, we show that similar to TCF21, AHR gene expression is increased in atherosclerotic lesions in mice in vivo using laser capture microdissection, and AHR protein is localized in human carotid atherosclerotic lesions where it is associated with protein kinases with a critical role in innate immune response. These data suggest that TCF21 can cooperate with AHR to activate an inflammatory gene expression program that is exacerbated by environmental stimuli, and may contribute to the overall risk for CAD.
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http://dx.doi.org/10.1371/journal.pgen.1006750DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5439967PMC
May 2017

A Foregut Duplication Cyst of the Stomach in Association with a Gastrointestinal Stromal Tumor and a Leiomyoma: A Case Report.

Case Rep Pathol 2016 21;2016:1537240. Epub 2016 Dec 21.

Department of Pathology, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec City, QC, Canada.

. Duplication cysts are rare benign lesions usually arising in the gastrointestinal tract. We report a case of a 52-year-old woman with an incidental gastric mass found on computed tomography during a pregraft workup for a familial cardiomyopathy. . The mass was completely excised by partial gastrectomy and gross examination revealed a cystic lesion containing two small solid nodules in its wall. Microscopic evaluation and immunohistochemistry study were performed to further characterize the cyst and the nodules. A comprehensive literature review of the NCBI database PubMed was also carried out. . While the cyst was diagnosed as a foregut duplication cyst, the solid nodules proved to be concomitant gastrointestinal stromal tumor (GIST) and leiomyoma. Both morphologic features and immunohistochemistry stains, including CD117, smooth muscle actin, and CD34 supported the diagnosis. Clinical course was benign and the patient had no clinical evidence of relapse ten months following the surgical procedure. The literature search did not reveal any other published case of a foregut duplication cyst presenting in combination with a GIST and a leiomyoma. . To our knowledge, this is the first case of a composite lesion comprising a foregut duplication cyst of the stomach along with a leiomyoma and a GIST.
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http://dx.doi.org/10.1155/2016/1537240DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209591PMC
December 2016

Transcriptomic Microenvironment of Lung Adenocarcinoma.

Cancer Epidemiol Biomarkers Prev 2017 03 12;26(3):389-396. Epub 2016 Dec 12.

Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, Canada.

Tissues surrounding tumors are increasingly studied to understand the biology of cancer development and identify biomarkers. A unique geographic tissue sampling collection was obtained from patients that underwent curative lobectomy for stage I pulmonary adenocarcinoma. Tumor and nontumor lung samples located at 0, 2, 4, and 6 cm away from the tumor were collected. Whole-genome gene expression profiling was performed on all samples ( = 5 specimens × 12 patients = 60). Analyses were carried out to identify genes differentially expressed in the tumor compared with adjacent nontumor lung tissues at different distances from the tumor as well as to identify stable and transient genes in nontumor tissues with respect to tumor proximity. The magnitude of gene expression changes between tumor and nontumor sites was similar with increasing distance from the tumor. A total of 482 up- and 843 downregulated genes were found in tumors, including 312 and 566 that were consistently differentially expressed across nontumor sites. Twenty-nine genes induced and 34 knocked-down in tumors were also identified. Tumor proximity analyses revealed 15,700 stable genes in nontumor lung tissues. Gene expression changes across nontumor sites were subtle and not statistically significant. This study describes the transcriptomic microenvironment of lung adenocarcinoma and adjacent nontumor lung tissues collected at standardized distances relative to the tumor. This study provides further insights about the molecular transitions that occur from normal tissue to lung adenocarcinoma and is an important step to develop biomarkers in nonmalignant lung tissues. .
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http://dx.doi.org/10.1158/1055-9965.EPI-16-0604DOI Listing
March 2017

Characterization of TCF21 Downstream Target Regions Identifies a Transcriptional Network Linking Multiple Independent Coronary Artery Disease Loci.

PLoS Genet 2015 May 28;11(5):e1005202. Epub 2015 May 28.

Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America; Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, United States of America.

To functionally link coronary artery disease (CAD) causal genes identified by genome wide association studies (GWAS), and to investigate the cellular and molecular mechanisms of atherosclerosis, we have used chromatin immunoprecipitation sequencing (ChIP-Seq) with the CAD associated transcription factor TCF21 in human coronary artery smooth muscle cells (HCASMC). Analysis of identified TCF21 target genes for enrichment of molecular and cellular annotation terms identified processes relevant to CAD pathophysiology, including "growth factor binding," "matrix interaction," and "smooth muscle contraction." We characterized the canonical binding sequence for TCF21 as CAGCTG, identified AP-1 binding sites in TCF21 peaks, and by conducting ChIP-Seq for JUN and JUND in HCASMC confirmed that there is significant overlap between TCF21 and AP-1 binding loci in this cell type. Expression quantitative trait variation mapped to target genes of TCF21 was significantly enriched among variants with low P-values in the GWAS analyses, suggesting a possible functional interaction between TCF21 binding and causal variants in other CAD disease loci. Separate enrichment analyses found over-representation of TCF21 target genes among CAD associated genes, and linkage disequilibrium between TCF21 peak variation and that found in GWAS loci, consistent with the hypothesis that TCF21 may affect disease risk through interaction with other disease associated loci. Interestingly, enrichment for TCF21 target genes was also found among other genome wide association phenotypes, including height and inflammatory bowel disease, suggesting a functional profile important for basic cellular processes in non-vascular tissues. Thus, data and analyses presented here suggest that study of GWAS transcription factors may be a highly useful approach to identifying disease gene interactions and thus pathways that may be relevant to complex disease etiology.
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http://dx.doi.org/10.1371/journal.pgen.1005202DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4447360PMC
May 2015

Extracellular matrix presentation modulates vascular smooth muscle cell mechanotransduction.

Matrix Biol 2015 Jan 15;41:36-43. Epub 2014 Nov 15.

Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Departments of Biochemistry and Ophthalmology, Boston University School of Medicine, Boston, MA 02118, USA; Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA. Electronic address:

The development of atherosclerosis involves phenotypic changes among vascular smooth muscle cells (VSMCs) that correlate with stiffening and remodeling of the extracellular matrix (ECM). VSMCs are highly sensitive to the composition and mechanical state of the surrounding ECM, and ECM remodeling during atherosclerosis likely contributes to pathology. We hypothesized that ECM mechanics and biochemistry are interdependent in their regulation of VSMC behavior and investigated the effect of ligand presentation on certain stiffness-mediated processes. Our findings demonstrate that substrate stiffening is not a unidirectional stimulus-instead, the influence of mechanics on cell behavior is highly conditioned on ligand biochemistry. This "stiffness-by-ligand" effect was evident for VSMC adhesion, spreading, cytoskeletal polymerization, and focal adhesion assembly, where VSMCs cultured on fibronectin (Fn)-modified substrates showed an augmented response to increasing stiffness, whereas cells on laminin (Ln) substrates showed a dampened response. By contrast, cells on Fn substrates showed a decrease in myosin light chain (MLC) phosphorylation and elongation with increasing stiffness, whereas Ln supported an increase in MLC phosphorylation and no change in cell shape with increasing stiffness. Taken together, these findings show that identical cell populations exhibit opposing responses to substrate stiffening depending on ECM presentation. Our results also suggest that the shift in VSMC phenotype in a developing atherosclerotic lesion is jointly regulated by stromal mechanics and biochemistry. This study highlights the complex influence of the blood vessel wall microenvironment on VSMC phenotype and provides insight into how cells may integrate ECM biochemistry and mechanics during normal and pathological tissue function.
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http://dx.doi.org/10.1016/j.matbio.2014.11.001DOI Listing
January 2015

Thermo-responsive poly(N-isopropylacrylamide) grafted onto microtextured poly(dimethylsiloxane) for aligned cell sheet engineering.

Colloids Surf B Biointerfaces 2012 Nov 25;99:108-15. Epub 2011 Oct 25.

Department of Biomedical Engineering, Boston University, College of Engineering, 44 Cummington St, Boston, MA 02215, USA.

Poly(N-isopropylacrylamide) (PNIPAAm)-grafted poly(dimethylsiloxane) (PDMS) offers an inexpensive, biocompatible, oxygen permeable, and easily microtextured thermo-responsive substrate for producing cell sheets. This study introduces a method of grafting PNIPAAm onto microtextured PDMS that is suitable for generating aligned vascular smooth muscle cell (VSMC) sheets. We examined a wide range of processing parameters in order to identify the conditions that led to acceptable sheet growth and detachment behavior. Substrates grafted under these conditions produced confluent cell sheets that fully detached in less than 10 min after lowering the culture temperature from 37 °C to 20 °C. The grafted layer thickness was determined to be 496±8 nm by atomic force microscopy. Surface characterization by Fourier transform infrared spectroscopy showed a relative grafting yield of 0.488±0.10, defined as the ratio of the PNIPAAm 1647 cm(-1) to the PDMS 2962 cm(-1) absorbance peaks. The water contact angle of the substrates was shown to change from 89.6° to 101.0° at 20 °C and 37 °C, respectively. We also found that cell behavior on PNIPAAm-grafted PDMS was not directly related to surface wettability or relative grafting densities.
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http://dx.doi.org/10.1016/j.colsurfb.2011.10.040DOI Listing
November 2012

Cell-cell interactions mediate the response of vascular smooth muscle cells to substrate stiffness.

Biophys J 2011 Aug;101(3):622-30

Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA.

The vessel wall experiences progressive stiffening with age and the development of cardiovascular disease, which alters the micromechanical environment experienced by resident vascular smooth muscle cells (VSMCs). In vitro studies have shown that VSMCs are sensitive to substrate stiffness, but the exact molecular mechanisms of their response to stiffness remains unknown. Studies have also shown that cell-cell interactions can affect mechanotransduction at the cell-substrate interface. Using flexible substrates, we show that the expression of proteins associated with cell-matrix adhesion and cytoskeletal tension is regulated by substrate stiffness, and that an increase in cell density selectively attenuates some of these effects. We also show that cell-cell interactions exert a strong effect on cell morphology in a substrate-stiffness dependent manner. Collectively, the data suggest that as VSMCs form cell-cell contacts, substrate stiffness becomes a less potent regulator of focal adhesion signaling. This study provides insight into the mechanisms by which VSMCs respond to the mechanical environment of the blood vessel wall, and point to cell-cell interactions as critical mediators of VSMC response to vascular injury.
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http://dx.doi.org/10.1016/j.bpj.2011.06.051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145282PMC
August 2011

The effect of stromal components on the modulation of the phenotype of human bronchial epithelial cells in 3D culture.

Biomaterials 2011 Oct 2;32(29):7169-80. Epub 2011 Jul 2.

Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA.

The stroma plays an important role in the development and progression of human diseases. Pulmonary diseases such as asthma, fibrosis and cancer are thought to be the result of altered communications between the epithelial and stromal tissue compartments. In order to study these epithelial-mesenchymal interactions, we developed a three dimensional (3D) in vitro model of the human airway that mimics bronchial morphology and function. This model consists of a type-I collagen matrix, normal human fetal lung fibroblasts (IMR-90) or primary human adult lung cancer-associated fibroblasts (LuCAFs), and a surface epithelium of normal human bronchial epithelial cells (HBECs). When cultured at an air-liquid interface (ALI), the epithelial component generated a well-differentiated pseudo-stratified bronchial epithelium that contained basal, ciliated, and non-ciliated (secretory) epithelial cells. IMR-90 and LuCAFs differentially altered the phenotype of HBECs in distinct ways. While IMR-90 permitted HBECs to form a typical respiratory surface epithelium, LuCAFs promoted HBECs to invade the collagen gel forming both epithelial nodules and cysts, suggesting that LuCAFs may alter the HBEC phenotype by modifying biomechanical signals conveyed through the extracellular matrix (ECM). Furthermore, LuCAFs secreted soluble factors that induced HBECs to express genes associated with immune responses, apoptosis, mitosis, cell survival, differentiation and cancer.
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http://dx.doi.org/10.1016/j.biomaterials.2011.06.017DOI Listing
October 2011

Results of microsurgical treatment of large and giant ICA aneurysms using the retrograde suction decompression (RSD) technique: series of 92 patients.

World Neurosurg 2010 Jun;73(6):683-7

Burdenko Neurosurgical Institute, Russian Academy of Medical Sciences, Moscow, Russia.

Background: Microsurgical treatment of large and giant paraclinoid internal carotid artery (ICA) aneurysms often requires the use of the retrograde suction decompression (RSD) technique to facilitate clipping. Surgical results, functional outcomes at discharge, and technique limitations based on single institution series are presented.

Materials And Methods: Between 1996 and 2009, eighty-three consecutive patients (19 to 68 years, mean 45.5 ± 9.9 years), predominantly women (69 women and 14 men) with large (23 patients, 27.7%) or giant (60 patients, 72.3%) paraclinoid aneurysms were surgically treated with the RSD technique performed by the neck route (62 patients, 74.4%) or later on, by endovascular means (21 patients, 25.3%). Patients were admitted after hemorrhage (48 patients, 57.9%), pseudotumor course (28 patients, 33.7%), mixed symptoms (5 patients, 6%), or asymptomatic (2 patients, 2.4%).

Results: In most RSD surgeries (90.4%) aneurysms were successfully excluded: neck was clipped in 57 patients (68.7%) or clipping with ICA reconstruction was achieved in 18 patients (21.7%). In six patients aneurysms were wrapped with glue (7.2%), trapped in one patient (1.2%), and in one patient, ICA balloon deconstruction was performed (1.2%). Good or excellent results (Glasgow Outcome Scale scores 4-5) at discharge were achieved in 69 patients (83.1%), 11 patients (13.3%) remained severely disabled (Glasgow Outcome Scale 3), and 3 patients died (3.6%).

Conclusions: Surgical clipping with the RSD method remains a treatment of choice with acceptable outcomes for patients not amenable for endovascular treatment.
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http://dx.doi.org/10.1016/j.wneu.2010.03.017DOI Listing
June 2010

Induction of the renal stanniocalcin-1 gene in rodents by water deprivation.

Mol Cell Endocrinol 2010 Oct 9;328(1-2):8-15. Epub 2010 Jun 9.

Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada N6A 5C1.

Stanniocalcin-1 (STC-1) is made by kidney collecting duct cells for targeting of nephron mitochondria to promote respiratory uncoupling and calcium uniport activity. However, the purpose of these actions and how the renal gene is regulated are poorly understood. This study has addressed the latter issue by monitoring renal STC-1 gene expression in different models of kidney function. Unilateral nephrectomy and over-hydration had no bearing on renal gene activity in adult Wistar rats. Dehydration, on the other hand, had time-dependent stimulatory effects in male and female kidney cortex, where STC-1 mRNA levels increased 8-fold by 72h. Medullary gene activity was significantly increased as well, but muted in comparison ( approximately 2-fold). Gene induction was accompanied by an increase in mitochondrial sequestration of STC-1 protein. Aldosterone and angiotensin II had no bearing on STC-1 gene induction, although there was evidence of a role for arginine vasopressin. Gene induction was unaltered in integrin alpha1 knockout mice, which have an impaired tonicity enhancer binding protein (TonEBP) response to dehydration. The STC-1 gene response could be cytoprotective in intent, as dehydration entails a fall in renal blood flow and a rise in medullary interstitial osmolality. Alternatively, STC-1 could have a role in salt and water balance as dehydration necessitates water conservation as well as controlled natriuresis and kaliuresis.
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http://dx.doi.org/10.1016/j.mce.2010.06.002DOI Listing
October 2010

Isolation of peptides from rat tissues: peptidomics vs. degradomics.

Adv Exp Med Biol 2009 ;611:399-400

Group of Regulatory Peptides, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Miklukho-Maklaya 16/10, 117997 Moscow, Russia.

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http://dx.doi.org/10.1007/978-0-387-73657-0_173DOI Listing
June 2009

beta-Actin-derived peptides isolated from acidic extract of rat spleen suppress tumor cell growth.

J Pept Sci 2008 Jul;14(7):811-8

Shemyakin-Ovchinnikov Institute of Bio-organic Chemistry, Russian Academy of Sciences, Moscow, V-437, GSP, Russia.

Twenty-two fragments of beta-actin and beta-actin-related protein were isolated from the acidic extracts of rat spleen tissue. beta-Actin fragments (75-90), (78-89), and (78-88), 0.01-1 microM, decreased live cell number of L929 murine tumor fibroblasts by 80-90%, with maximal cytotoxic effect of 30-40%. The fragments of (78-90) segment and the fragment of beta-actin-related protein (69-77) were less active (inhibitory effect up to 55%, cytotoxic-up to 25%).
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http://dx.doi.org/10.1002/psc.1008DOI Listing
July 2008

Stanniocalcin-1 secretion and receptor regulation in kidney cells.

Am J Physiol Renal Physiol 2008 Apr 16;294(4):F788-94. Epub 2008 Jan 16.

Dept. of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Univ. of Western Ontario, London, Ontario, Canada N6A 5C1.

Kidney collecting duct principal cells are the main source of stanniocalcin-1 (STC-1) production and secretion. From there, the hormone targets thick ascending limb and distal convoluted tubule cells, as well as collecting duct cells. More specifically, STC-1 targets their mitochondria to exert putative antiapoptotic effects. Two distal tubule cell lines serve as models of STC-1 production and/or mechanism of action. Madin-Darby canine kidney-1 (MDCK-1) cells mimic collecting duct cells in their synthesis of STC-1 ligand and receptor, whereas inner medullary collecting duct-3 (IMCD-3) cells respond to additions of STC-1 by increasing their respiration rate. In the present study, MDCK cell STC-1 secretion was examined under normal and hypertonic conditions, vectorally, and in response to hormones and signal transduction pathway activators/inhibitors. STC-1 receptor regulation was monitored in both cell lines in response to changing ligand concentration. The results showed that NaCl-induced hypertonicity had concentration-dependent stimulatory effects on STC-1 secretion, as did the PKC activator TPA. Calcium and ionomycin were inhibitory, whereas calcium receptor agonists had no effect. Angiotensin II, aldosterone, atrial natriuretic factor, antidiuretic hormone, and forskolin also had no effects. Moreover, STC-1 secretion exhibited no vectoral preference. STC-1 receptors were insensitive to homologous downregulation in both cell lines. In contrast, they were upregulated when STC-1 secretion was inhibited by calcium. The findings suggest that hypertonicity-induced STC-1 secretion is regulated through PKC activation and that high intracellular calcium levels are a potent inhibitor of release. More intriguingly, the results suggest that the receptor may not accompany STC-1 in its passage to the mitochondria.
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http://dx.doi.org/10.1152/ajprenal.00553.2007DOI Listing
April 2008

Comparison of biphasic insulin aspart 30 given three times daily or twice daily in combination with metformin versus oral antidiabetic drugs alone in patients with poorly controlled type 2 diabetes: a 16-week, randomized, open-label, parallel-group trial conducted in russia.

Clin Ther 2007 Nov;29(11):2374-84

Department of Prophylactic Medicine, Post-graduate Medical Education Institute, Khabarovsk, Russia.

Background: Modern premixed insulins offer a flexible approach to the initiation of insulin therapy in patients with poorly controlled type 2 diabetes. A disadvantage of twice-daily regimens of biphasic insulin aspart 30 (BIAsp 30) is that lunchtime control (when no insulin is administered) can be suboptimal. Therefore, it is possible that administering BIAsp 30 thrice daily might further optimize glycemic control and offer an option for patients in whom metformin (MET) is contraindicated.

Objective: This study evaluated the efficacy and safety profiles of 2 different regimens of BIAsp 30 compared with a regimen consisting of oral antidiabetic drugs (OADs) alone.

Methods: In this multicenter, randomized, open-label, parallel-group trial, insulin-naive patients with poorly controlled type 2 diabetes (baseline glycosylated hemoglobin [HbA(1c) > or =8.0%) who were taking OADs (a sulfonylurea or meglitinide with/without MET or MET only) were randomized to receive BIAsp 30 TID, BIAsp 30 BID + MET, or continuation of their current OAD therapy for 16 weeks. The primary end point was HbA(1c) at the end of the study. Secondary end points included reductions in HbA(1c), mean blood glucose (BG), prandial increment, mean 7-point self-monitored BG profile, weight changes, tolerability (hypoglycemia, adverse events), and satisfaction/quality of life (derived from 2 questionnaires completed at weeks 0, 8, and 16).

Results: The study enrolled 308 insulin-naive patients with type 2 diabetes (78.9% female; mean age, 58.3 years; body mass index, 29.4 kg/m(2); HbA(1c), 10.3%). Both BIAsp 30 TID and BIAsp 30 BID + MET were associated with significantly greater mean (SD) reductions in HbA(1c) relative to OADs alone (absolute percent reduction: 2.9% [1.5%], 3.0% [1.6%], and 2.1% [1.4%], respectively; P < 0.001, both insulin groups vs OAD group) and improved post-prandial glucose control (reduction in mean post-prandial glucose:-6.32 [4.07], -6.44 [4.70], and -3.59 [4.22] mmol/L; P < 0.001, both insulin groups vs OAD group). The mean decrease in the prandial increment was -1.26 mmol/L for BIAsp 30 TID, -2.15 mmol/L for BIAsp 30 BID + MET, and -0.44 mmol/L for OAD. The differences in reduction in the prandial increment were statistically significant for BIAsp 30 TID versus OAD (P = 0.047), BIAsp 30 BID + MET versus OAD (P < 0.001), and BIAsp 30 TID versus BIAsp 30 BID + MET (P = 0.042). Mean body weight increased significantly from baseline with both BIAsp 30 TID and BIAsp 30 BID + MET (+1.71 and +1.50 kg, respectively; both, P < 0.001), and decreased significantly in the OAD group (-0.75 kg; P = 0.003). There were no major hypoglycemic events, and most hypoglycemic events were recorded as symptoms only (144/158 [91.1%]). There were no significant differences in the mean frequency of overall hypoglycemic episodes between BIAsp 30 TID and BIAsp 30 BID + MET (0.73 and 0.69 episodes per patient-year, respectively).

Conclusions: In these patients with type 2 diabetes that was poorly controlled by OADs, BIAsp 30 TID and BIAsp 30 BID plus MET were associated with significantly greater reductions in HbA(1c) and postprandial BG compared with OADs alone. The insulin regimens were associated with significantly more weight gain than OADs alone. There were no differences in rates of hypoglycemia between the insulin regimens.
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http://dx.doi.org/10.1016/j.clinthera.2007.11.017DOI Listing
November 2007

Anti-apoptotic effect of retinoic acid on retinal progenitor cells mediated by a protein kinase A-dependent mechanism.

Cell Res 2007 Feb;17(2):151-62

Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10 Miklukho-Maklaya, Moscow 117997, Russia.

Retinal progenitor cells (RPCs) are neural stem cells able to differentiate into any normal adult retinal cell type, except for pigment epithelial cells. Retinoic acid (RA) is a powerful growth/differentiation factor that generally causes growth inhibition, differentiation and/or apoptosis. In this study, we demonstrate that RA not only affects mouse RPC differentiation but also improves cell survival by reducing spontaneous apoptotic rate without affecting RPC proliferation. The enhanced cell survival was accompanied by a significant upregulation of the expression of protein kinase A (PKA) and several protein kinase C (PKC) isoforms. Treatment of cells grown in RA-free media with 8-bromoadenosine3',5'-cyclic monophosphate, a known activator of PKA, resulted in an anti-apoptotic effect similar to that caused by RA; whereas the PKA inhibitor N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride led to a significant ( approximately 32%) increase in apoptosis. In contrast, treatment of RPCs with any of two PKC selective inhibitors, 2,2',3,3',4,4'-hexahydroxy-1,1'-biphenyl-6,6'-dimethanol dimethyl ether and bisindolylmaleimide XI, led to diminished apoptosis; while a PKC activator, phorbol 12-myristate 13-acetate, increased apoptosis. These and other data suggest that the effect of RA on RPC survival is mostly due to the increased anti-apoptotic activity elicited by PKA, which might in turn be antagonized by PKC. Such a mechanism is a new example of tight regulation of important biological processes triggered by RA. Although the detailed mechanisms remain to be elucidated, we provide evidence that the pro-survival effect of RA on RPCs is not mediated by changed expression of p53 or bcl-2, and appears to be independent of beta-amyloid, Fas ligand, TNF-alpha, ganglioside GM1 and ceramide C16-induced apoptotic pathways.
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http://dx.doi.org/10.1038/sj.cr.7310147DOI Listing
February 2007

Stimulation of fibroblast proliferation by neokyotorphin requires Ca influx and activation of PKA, CaMK II and MAPK/ERK.

FEBS J 2007 Jan;274(2):474-84

Regulatory Peptides Group, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia.

Neokyotorphin [TSKYR, hemoglobin alpha-chain fragment (137-141)] has previously been shown to enhance fibroblast proliferation, its effect depending on cell density and serum level. Here we show the dependence of the effect of neokyotorphin on cell type and its correlation with the effect of protein kinase A (PKA) activator 8-Br-cAMP, but not the PKC activator 4beta-phorbol 12-myristate, 13-acetate (PMA). In L929 fibroblasts, the proliferative effect of neokyotorphin was suppressed by the Ca2+ L-type channel inhibitors verapamil or nifedipine, the intracellular Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester, kinase inhibitors H-89 (PKA), KN-62 (Ca2+/calmodulin-dependent kinase II) and PD98059 (mitogen-activated protein kinase). The proliferative effect of 8-Br-cAMP was also suppressed by KN-62 and PD98059. PKC suppression (downregulation with PMA or inhibition with bisindolylmaleimide XI) did not affect neokyotorphin action. The results obtained point to a cAMP-like action for neokyotorphin.
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http://dx.doi.org/10.1111/j.1742-4658.2006.05594.xDOI Listing
January 2007

Antitumor effect of valorphin in vitro and in vivo: combined action with cytostatic drugs.

Cancer Biol Ther 2005 Jan 16;4(1):118-24. Epub 2005 Jan 16.

Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia.

The action of the cytostatic drugs (epirubicin and vincristine) in combination with the endogenous antiproliferative beta-hemoglobin fragment (33-39), valorphin, was studied in tumor (L929 and A549) cell cultures, primary culture of murine bone marrow cells and in murine model of breast carcinoma in vivo. Simultaneous application of 1 microM valorphin and 1 microM epirubicin, in vitro, did not result in an additive suppressive effect on cell culture growth. Additive effects were achieved with alternating applications of the peptide and the drugs, namely, 0.5 microM (but not 1 microM) epirubicin added 24 h prior to 1 microM valorphin; 1 microM valorphin added 48 h prior to 0.1 microM epirubicin, or 0.1 microM vincristine, or 0.05 microM vincristine, which resulted in 100% cell death in the both series with vincristine and up to 78% cell biomass reduction in the experiments with epirubicin. In the in vivo model (female BLRB mice with subcutaneously inoculated syngeneic mammary carcinoma), simultaneous treatment with 25 mg/m(2) epirubicin and 1 mg/kg valorphin resulted in 42% of tumor growth inhibition, as compared with the negative control group and 22% inhibition as compared with the epirubcin-treated group (at 20th day of treatment). Survival was significantly improved (69% compared to 39% in the group treated with epirubicin only) at day 26 after the treatment beginning.
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http://dx.doi.org/10.4161/cbt.4.1.1474DOI Listing
January 2005

What to synthesize? From Emil Fischer to peptidomics.

J Pept Sci 2003 Sep;9(9):553-62

Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia.

The driving forces, incentives and strategic targets of peptide synthesis have undergone considerable evolution during the centenary following the pioneer work of Emil Fischer. In those days peptide synthesis was considered as a way of confirming the polypeptide theory of protein structure. The scientific community also expected (naively) that the synthesis would eventually lead to the creation of artificial living organisms. Only in the 1950s, when the first exact amino acid sequences were established did peptide chemistry obtain firmer ground and clearly defined targets. The total synthesis of peptide hormones and antibiotics became possible, providing valuable material for elucidating structure-functional relationships and the mechanisms of biological action. In the following years the number of peptides isolated from various biological sources grew with impressive speed and peptides became known as the most abundant, ubiquitous group of low molecular bioregulators. The design and synthesis of novel peptide based pharmaceuticals became an important area of peptide chemistry. At present we are facing the challenge of analysing the structures and bioactivities of total sets of peptides, i.e. peptidoms, present in concrete tissues or groups of cells. The results obtained along these lines at the IBCH RAS Institute of Bioorganic Chemistry are briefly considered in the review.
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http://dx.doi.org/10.1002/psc.480DOI Listing
September 2003

Proliferative activity of neokyotorphin-related hemoglobin fragments in cell cultures.

Protein Pept Lett 2003 Aug;10(4):386-95

Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117871 Moscow, Russia.

alpha-Hemoglobin fragments alpha-(133-141), alpha-(134-141), alpha-(135-141), alpha-(137-141), alpha-(134-140), alpha-(133-138), alpha-(134-140) and alpha-(137-138) stimulate L929 tumor cell proliferation, alpha-(134-141) being the most active. alpha-(134-141) stimulates proliferation of M3 melanoma cells, murine embryonic fibroblasts, primary cultures of red bone marrow and spleen cells. In L929 cells the effect of alpha-(134-141) is cell density independent; in M3 cells alpha-(137-141) and alpha-(134-141) are most active at density 10,000 cells/well (96 well plate) independently on FBS content.
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http://dx.doi.org/10.2174/0929866033478780DOI Listing
August 2003

Antiproliferative action of valorphin in cell cultures.

J Pept Sci 2002 Aug;8(8):438-52

Institute of Bioorganic Chemistry, Moscow, Russia.

The antiproliferative effects of the haemoglobin beta-chain fragment (33-39) (valorphin or VV-haemorphin-5) were studied in a panel of tumour cell lines and normal cells of different origin, using various methods of activity determination (trypan blue inclusion test, sulphorhodamine B staining, MTT staining, flow cytometry and clonogenic test). Valorphin suppressed the proliferation of tumour cells by 25%-95%, depending on the cell line. The maximal valorphin activity was detected in transformed cells of fibroblastic (L929) and epithelial (MCF-7) origin, transformed haematopoietic cells (K562, HL-60) being less sensitive. In normal cells, valorphin activity was several fold lower (10%-15%). A study of the dynamics of cell proliferation in L929 cells using a visual cell count and flow cytometry showed that valorphin induced reversible and relatively short (24 h) S-phase arrest of cell proliferation, accompanied by a reversible increase of cell size. The proliferation delay was followed by a comparatively long period of reversible resistance of the cells to the peptide (96 h) when the cells are dividing at normal rate. The same dynamics were demonstrated for A549, MCF-7 and primary murine breast carcinoma cells. On the basis of the data obtained, a pattern of regulation of cell growth by valorphin is suggested.
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http://dx.doi.org/10.1002/psc.402DOI Listing
August 2002

Family of hemorphins: co-relations between amino acid sequences and effects in cell cultures.

Peptides 2002 May;23(5):903-10

Group of Protein Research, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, Moscow, Russia.

Hemorphins, i.e. endogenous fragments of beta-globin chain segment (32-41) LVVYPWTQRY(F) suppress the growth of transformed murine fibroblasts L929 cell culture, the effect is due to cytotoxicity and inhibition of cell proliferation. The contribution of cytotoxicity depends on the presence of Leu(32): VV-hemorphins, except VV-hemorphin-4, exhibit cytotoxicity significantly higher than respective LVV-hemorphins. Decrease of cell number induced by hemorphins depend on the extent of N- and C-terminal degradation of hemorphins: VV-hemorphins in most cases are more active than LVV-, V-hemorphins, and hemorphins. In the group of VV-hemorphins the activity of VV-hemorphin-5 (valorphin) is significantly higher than of VV-hemorphin-7, VV-hemorphin-6, and VV-hemorphin-4, meaning that the presence of C-terminal Gln is important for suppressing of cell number. The amino acid sequence VVYPWTQ corresponding to valorphin was identified as important for manifestation of the both cytotoxic and antiproliferative effects.
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http://dx.doi.org/10.1016/s0196-9781(02)00017-7DOI Listing
May 2002
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