Publications by authors named "Jannette M Dufour"

45 Publications

Mechanisms linking endoplasmic reticulum (ER) stress and microRNAs to adipose tissue dysfunction in obesity.

Crit Rev Biochem Mol Biol 2021 Jun 28:1-27. Epub 2021 Jun 28.

Laboratory of Nutrigenomics, Inflammation and Obesity Research, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA.

Over accumulation of lipids in adipose tissue disrupts metabolic homeostasis by affecting cellular processes. Endoplasmic reticulum (ER) stress is one such process affected by obesity. Biochemical and physiological alterations in adipose tissue due to obesity interfere with adipose ER functions causing ER stress. This is in line with increased irregularities in other cellular processes such as inflammation and autophagy, affecting overall metabolic integrity within adipocytes. Additionally, microRNAs (miRNAs), which can post-transcriptionally regulate genes, are differentially modulated in obesity. A better understanding and identification of such miRNAs could be used as novel therapeutic targets to fight against diseases. In this review, we discuss ways in which ER stress participates as a common molecular process in the pathogenesis of obesity-associated metabolic disorders. Moreover, our review discusses detailed underlying mechanisms through which ER stress and miRNAs contribute to metabolic alteration in adipose tissue in obesity. Hence, identifying mechanistic involvement of miRNAs-ER stress cross-talk in regulating adipose function during obesity could be used as a potential therapeutic approach to combat chronic diseases, including obesity.
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http://dx.doi.org/10.1080/10409238.2021.1925219DOI Listing
June 2021

Helicase-like transcription factor-deletion from the tumor microenvironment in a cell line-derived xenograft model of colorectal cancer reprogrammed the human transcriptome-S-nitroso-proteome to promote inflammation and redirect metastasis.

PLoS One 2021 19;16(5):e0251132. Epub 2021 May 19.

Department of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, United States of America.

Methylation of the HLTF gene in colorectal cancer (CRC) cells occurs more frequently in men than women. Progressive epigenetic silencing of HLTF in tumor cells is accompanied by negligible expression in the tumor microenvironment (TME). Cell line-derived xenografts (CDX) were established in control (Hltf+/+) and Hltf-deleted male Rag2-/-IL2rg-/- mice by direct orthotopic cell microinjection (OCMI) of HLTF+/+HCT116 Red-FLuc cells into the submucosa of the cecum. Combinatorial induction of IL6 and S100A8/A9 in the Hltf-deleted TME with ICAM-1 and IL8 in the primary tumor activated a positive feedback loop. The proinflammatory niche produced a major shift in CDX metastasis to peritoneal dissemination compared to controls. Inducible nitric oxide (iNOS) gene expression and transactivation of the iNOS-S100A8/A9 signaling complex in Hltf-deleted TME reprogrammed the human S-nitroso-proteome. POTEE, TRIM52 and UN45B were S-nitrosylated on the conserved I/L-X-C-X2-D/E motif indicative of iNOS-S100A8/A9-mediated S-nitrosylation. 2D-DIGE and protein identification by MALDI-TOF/TOF mass spectrometry authenticated S-nitrosylation of 53 individual cysteines in half-site motifs (I/L-X-C or C-X-X-D/E) in CDX tumors. POTEE in CDX tumors is both a general S-nitrosylation target and an iNOS-S100A8/A9 site-specific (Cys638) target in the Hltf-deleted TME. REL is an example of convergence of transcriptomic-S-nitroso-proteomic signaling. The gene is transcriptionally activated in CDX tumors with an Hltf-deleted TME, and REL-SNO (Cys143) was found in primary CDX tumors and all metastatic sites. Primary CDX tumors from Hltf-deleted TME shared 60% of their S-nitroso-proteome with all metastatic sites. Forty percent of SNO-proteins from primary CDX tumors were variably expressed at metastatic sites. Global S-nitrosylation of proteins in pathways related to cytoskeleton and motility was strongly implicated in the metastatic dissemination of CDX tumors. Hltf-deletion from the TME played a major role in the pathogenesis of inflammation and linked protein S-nitrosylation in primary CDX tumors with spatiotemporal continuity in metastatic progression when the tumor cells expressed HLTF.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0251132PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8133447PMC
May 2021

Dietary Annatto-Extracted Tocotrienol Reduces Inflammation and Oxidative Stress, and Improves Macronutrient Metabolism in Obese Mice: A Metabolic Profiling Study.

Nutrients 2021 Apr 13;13(4). Epub 2021 Apr 13.

Department of Nutrition, University of California at Davis, Davis, CA 95616, USA.

Obesity and its related complications are a world-wide health problem. Dietary tocotrienols (TT) have been shown to improve obesity-associated metabolic disorders, such as hypercholesterolemia, hyperglycemia, and gut dysbiosis. This study examined the hypothesis that the antioxidant capacity of TT alters metabolites of oxidative stress and improves systemic metabolism. C57BL/6J mice were fed either a high-fat diet (HFD control) or HFD supplemented with 800 mg annatto-extracted TT/kg (HFD+TT800) for 14 weeks. Sera from obese mice were examined by non-targeted metabolite analysis using UHPLC/MS. Compared to the HFD group, the HFD+TT800 group had higher levels of serum metabolites, essential amino acids (lysine and methionine), sphingomyelins, phosphatidylcholine, lysophospholipids, and vitamins (pantothenate, pyridoxamine, pyridoxal, and retinol). TT-treated mice had lowered levels of serum metabolites, dicarboxylic fatty acids, and inflammatory/oxidative stress markers (trimethylamine N-oxide, kynurenate, 12,13-DiHOME, and 13-HODE + 9-HODE) compared to the control. The results suggest that TT supplementation lowered inflammation and oxidative stress (oxidized glutathione and GSH/GSSH) and improved macronutrient metabolism (carbohydrates) in obese mice. Thus, TT actions on metabolites were beneficial in reducing obesity-associated hypercholesterolemia/hyperglycemia. The effects of a non-toxic dose of TT in mice support the potential for clinical applications in obesity and metabolic disease.
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http://dx.doi.org/10.3390/nu13041267DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8069008PMC
April 2021

Therapeutic application of Sertoli cells for treatment of various diseases.

Semin Cell Dev Biol 2021 Apr 25. Epub 2021 Apr 25.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Department of Medical Education, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA. Electronic address:

Sertoli cells (SCs) are immune privileged cells found in the testis that function to immunologically protect maturing germ cells from immune destruction. This immune protection is due to the blood-testis-barrier, which prevents infiltration of cytotoxic immune cells and antibodies, and SC production of immunomodulatory factors, that favor a tolerogenic environment. The ability of SCs to create an immune privileged environment has led to the exploration of their potential use in the treatment of various diseases. SCs have been utilized to create a tolerogenic ectopic microenvironment, to protect co-grafted cells, and to deliver therapeutic proteins through gene therapy. To date, numerous studies have reported the potential use of SCs for the treatment of diabetes, neurodegenerative disorders, and restoration of spermatogenesis. Additionally, SCs have been investigated as a delivery vehicle for therapeutic products to treat other diseases like Laron syndrome, muscular dystrophy, and infections. This review will provide an overview of these therapeutic applications.
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http://dx.doi.org/10.1016/j.semcdb.2021.04.007DOI Listing
April 2021

C-Peptide as a Therapy for Type 1 Diabetes Mellitus.

Biomedicines 2021 Mar 8;9(3). Epub 2021 Mar 8.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.

Diabetes mellitus (DM) is a complex metabolic disease affecting one-third of the United States population. It is characterized by hyperglycemia, where the hormone insulin is either not produced sufficiently or where there is a resistance to insulin. Patients with Type 1 DM (T1DM), in which the insulin-producing beta cells are destroyed by autoimmune mechanisms, have a significantly increased risk of developing life-threatening cardiovascular complications, even when exogenous insulin is administered. In fact, due to various factors such as limited blood glucose measurements and timing of insulin administration, only 37% of T1DM adults achieve normoglycemia. Furthermore, T1DM patients do not produce C-peptide, a cleavage product from insulin processing. C-peptide has potential therapeutic effects in vitro and in vivo on many complications of T1DM, such as peripheral neuropathy, atherosclerosis, and inflammation. Thus, delivery of C-peptide in conjunction with insulin through a pump, pancreatic islet transplantation, or genetically engineered Sertoli cells (an immune privileged cell type) may ameliorate many of the cardiovascular and vascular complications afflicting T1DM patients.
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http://dx.doi.org/10.3390/biomedicines9030270DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8000702PMC
March 2021

SLC6A14 deficiency is linked to obesity, fatty liver, and metabolic syndrome but only under conditions of a high-fat diet.

Biochim Biophys Acta Mol Basis Dis 2021 May 26;1867(5):166087. Epub 2021 Jan 26.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA. Electronic address:

SLC6A14 is a Na/Cl-coupled transporter for neutral/cationic amino acids, expressed in ileum and colon. A single-nucleotide polymorphism (SNP), rs2011162 (-22,510C > G), in SLC6A14 coding for the 3'-untranslated region (3'-UTR) is associated with obesity in humans. But the impact of this polymorphism on the transporter expression and its connection to obesity are not known. Our objective was to address these issues. The impact of rs2011162 (-22,510C > G) on SLC6A14 expression was monitored using a luciferase reporter. The link between Slc6a14 and obesity was investigated in wild type and Slc6a14 mice when fed a normal diet or a high-fat diet. The obesity-associated 3'-UTR polymorphism reduced SLC6A14 expression. With a high-fat diet, Slc6a14 mice gained more weight than wild type mice. With normal diet, there was no difference between the two genotypes. The gain in body weight with the high-fat diet in Slc6a14 mice was accompanied with metabolic syndrome. With the high-fat diet, Slc6a14 mice showed increased food intake, developed fatty liver, and altered plasma amino acid profile. The high-fat diet-associated hepatic steatosis in Slc6a14 mice showed male preponderance. We conclude that the 3'-UTR SNP in SLC6A14 associated with obesity decreases the expression of SLC6A14 and that the deficiency of SLC6A14 is linked to obesity. This is supported by the findings that Slc6a14 mice develop obesity, fatty liver, and metabolic syndrome. This connection is evident only with a high-fat diet. Therefore, dietary/pharmacologic interventions that induce SLC6A14 expression in the intestinal tract might have potential for obesity prevention..
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http://dx.doi.org/10.1016/j.bbadis.2021.166087DOI Listing
May 2021

Neonatal Pig Sertoli Cells Survive Xenotransplantation by Creating an Immune Modulatory Environment Involving CD4 and CD8 Regulatory T Cells.

Cell Transplant 2020 Jan-Dec;29:963689720947102

Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA.

The acute cell-mediated immune response presents a significant barrier to xenotransplantation. Immune-privileged Sertoli cells (SC) can prolong the survival of co-transplanted cells including xenogeneic islets, hepatocytes, and neurons by protecting them from immune rejection. Additionally, SC survive as allo- and xenografts without the use of any immunosuppressive drugs suggesting elucidating the survival mechanism(s) of SC could be used to improve survival of xenografts. In this study, the survival and immune response generated toward neonatal pig SC (NPSC) or neonatal pig islets (NPI), nonimmune-privileged controls, was compared after xenotransplantation into naïve Lewis rats without immune suppression. The NPSC survived throughout the study, while NPI were rejected within 9 days. Analysis of the grafts revealed that macrophages and T cells were the main immune cells infiltrating the NPSC and NPI grafts. Further characterization of the T cells within the grafts indicated that the NPSC grafts contained significantly more cluster of differentiation 4 (CD4) and cluster of differentiation 8 (CD8) regulatory T cells (Tregs) at early time points than the NPI grafts. Additionally, the presence of increased amounts of interleukin 10 (IL-10) and transforming growth factor (TGF) β and decreased levels of tumor necrosis factor (TNF) α and apoptosis in the NPSC grafts compared to NPI grafts suggests the presence of regulatory immune cells in the NPSC grafts. The NPSC expressed several immunoregulatory factors such as TGFβ, thrombospondin-1 (THBS1), indoleamine-pyrrole 2,3-dioxygenase, and galectin-1, which could promote the recruitment of these regulatory immune cells to the NPSC grafts. In contrast, NPI grafts had fewer Tregs and increased apoptosis and inflammation (increased TNFα, decreased IL-10 and TGFβ) suggestive of cytotoxic immune cells that contribute to their early rejection. Collectively, our data suggest that a regulatory graft environment with regulatory immune cells including CD4 and CD8 Tregs in NPSC grafts could be attributed to the prolonged survival of the NPSC xenografts.
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http://dx.doi.org/10.1177/0963689720947102DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7564626PMC
July 2021

Metabolic benefits of annatto-extracted tocotrienol on glucose homeostasis, inflammation, and gut microbiome.

Nutr Res 2020 05 17;77:97-107. Epub 2020 Apr 17.

Center of Excellence for Integrative Health, Texas Tech University Health Sciences Center, Lubbock, TX; Obesity Research Institute, Texas Tech University, Lubbock, TX; Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, TX. Electronic address:

Emerging evidence suggests that the gut microbiome plays an important role in the pathophysiology of both obesity and type 2 diabetes mellitus. We previously reported that dietary annatto-extracted tocotrienol exerts beneficial effects by modulating inflammatory responses in mice fed a high-fat diet (HFD). The purpose of this study was to test the hypothesis that tocotrienol supplementation when combined with an HFD would result in an altered gut microbiota composition. For 14 weeks, forty-eight male C57BL/6J mice were assigned to 4 groups-low-fat diet, HFD, HFD supplemented with annatto-extracted tocotrienol at 800 mg/kg diet (AT), and HFD supplemented with metformin at 200 mg/kg diet. Glucose homeostasis was assessed by glucose and insulin tolerance tests, serum and pancreas insulin levels, and histological assessments of insulin and glucagon in pancreatic tissue. The concentrations of adipokines were measured in white adipose tissues. For the gut microbiome analysis, cecal content was collected, DNA was extracted, and 16S rRNA gene sequencing was performed. AT supplementation improved glucose homeostasis and lowered resistin, leptin, and interleukin-6 levels in white adipose tissue. Relative to the HFD group, AT-supplemented mice showed a decrease in the Firmicutes to Bacteroidetes ratio and had a lower abundance of Ruminococcus lactaris, Dorea longicatena, and Lachnospiraceae family. The relative abundance of Akkermansia muciniphila was increased in the AT group compared to the low-fat diet group. The association between the metabolic improvements and the identified bacterial taxa suggests a potential metabolic modulation caused by AT supplementation through the gut microbiota composition in mice fed an HFD.
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http://dx.doi.org/10.1016/j.nutres.2020.04.001DOI Listing
May 2020

Autophagy in metabolic syndrome: breaking the wheel by targeting the renin-angiotensin system.

Cell Death Dis 2020 02 3;11(2):87. Epub 2020 Feb 3.

Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA.

Metabolic syndrome (MetS) is a complex, emerging epidemic which disrupts the metabolic homeostasis of several organs, including liver, heart, pancreas, and adipose tissue. While studies have been conducted in these research areas, the pathogenesis and mechanisms of MetS remain debatable. Lines of evidence show that physiological systems, such as the renin-angiotensin system (RAS) and autophagy play vital regulatory roles in MetS. RAS is a pivotal system known for controlling blood pressure and fluid balance, whereas autophagy is involved in the degradation and recycling of cellular components, including proteins. Although RAS is activated in MetS, the interrelationship between RAS and autophagy varies in glucose homeostatic organs and their cross talk is poorly understood. Interestingly, autophagy is attenuated in the liver during MetS, whereas autophagic activity is induced in adipose tissue during MetS, indicating tissue-specific discordant roles. We discuss in vivo and in vitro studies conducted in metabolic tissues and dissect their tissue-specific effects. Moreover, our review will focus on the molecular mechanisms by which autophagy orchestrates MetS and the ways future treatments could target RAS in order to achieve metabolic homeostasis.
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http://dx.doi.org/10.1038/s41419-020-2275-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6997396PMC
February 2020

Maternal exercise before and during pregnancy alleviates metabolic dysfunction associated with high-fat diet in pregnant mice, without significant changes in gut microbiota.

Nutr Res 2019 09 8;69:42-57. Epub 2019 Aug 8.

Department of Kinesiology, Health, and Nutrition, University of Texas at San Antonio, San Antonio, TX.

Although maternal exercise before and during pregnancy is beneficial, the effects of exercise on microbiota changes during pregnancy are unknown. Here we tested the hypothesis that maternal exercise before and during pregnancy would positively affect glucose homeostasis, pancreatic cell function, and gut microbiota dysbiosis in high-fat diet (HFD) fed dams. Female C57BL/6 mice were fed either a HFD or a low-fat diet (LFD) for 12 weeks. The HFD mice were split into two groups for 4 weeks prior to pregnancy initiation and throughout the pregnancy: sedentary (HFD) or exercised (HFD + Ex). Food intake, body weight, body composition, and glucose and insulin tolerance were measured. At gestation day 19, blood, pancreas, gonadal visceral and subcutaneous fat, plantaris muscle, and cecum were collected for analysis. Both HFD and HFD + Ex mice had impaired glucose clearance compared to LFD mice at 15 days of gestation. No changes were found in pancreatic α- or β-cell health. HFD + Ex mice had significantly reduced visceral fat mass, serum insulin, and leptin levels and increased high-density lipoprotein levels, compared to HFD-fed mice. In contrast to our hypothesis, microbiota diversity and composition were not different among groups. The relative abundance of five bacterial phyla, such as Firmicutes, Bacteroidetes, Verrucomicrobia, Deferribacteres, and Actinobacteria, were not significantly altered with diet or exercise during pregnancy. Our findings suggest that maternal exercise prevents excess visceral fat accumulation, hyperinsulinemia, and hyperleptinemia associated with a HFD, but not through the alterations of gut microbiota composition or diversity during pregnancy.
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http://dx.doi.org/10.1016/j.nutres.2019.08.002DOI Listing
September 2019

Effect of annatto-extracted tocotrienols and green tea polyphenols on glucose homeostasis and skeletal muscle metabolism in obese male mice.

J Nutr Biochem 2019 05 10;67:36-43. Epub 2019 Feb 10.

Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, TX; Center of Excellence for Integrative Health, Texas Tech University Health Sciences Center, Lubbock, TX; Obesity Research Cluster, Texas Tech University, Lubbock, TX. Electronic address:

Skeletal muscle is the major site for glucose uptake and thus plays an important role in initiating insulin resistance in type 2 diabetes mellitus. This study evaluated the effects of tocotrienols (TT) and green tea polyphenols (GTP) individually or in combination on glucose homeostasis and skeletal muscle metabolism in obese mice with insulin resistance and elevation of blood glucose. Forty-eight male mice were fed a high-fat diet and assigned to 4 groups in a 2 (no TT vs. 400 mg TT/kg diet) × 2 (no GTP vs. 0.5% vol/wt GTP in water) for 14 weeks. Both GTP and TT improved area under curve of insulin intolerance; while GTP increased serum insulin levels in obese mice, probably due to the addition of sweetener in drinking water. An interaction (TT×GTP) was observed in glucose tolerance test, total pancreas insulin concentration, and citrate synthase activity of soleus in mice. Neither TT nor GTP affected insulin and glucagon protein expression in pancreas based on immunohistochemistry. Both TT and GTP individually increased soleus muscle weight of mice; while only GTP increased gastrocnemius muscle weight of mice. The TT+GTP group had the greatest gastrocnemius muscle cross sectional area than other groups. GTP, not TT, induced cytochrome c oxidase activity and reduced thiobarbituric acid reactive substances levels in soleus muscle. Our results suggest that TT and GTP, individually or synergistically have the potential to improve skeletal muscle metabolism in obese mice by improving glucose homeostasis, reducing lipid peroxidation, and increasing rate limiting enzymes of oxidative phosphorylation.
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http://dx.doi.org/10.1016/j.jnutbio.2019.01.021DOI Listing
May 2019

Annatto-extracted tocotrienols improve glucose homeostasis and bone properties in high-fat diet-induced type 2 diabetic mice by decreasing the inflammatory response.

Sci Rep 2018 07 27;8(1):11377. Epub 2018 Jul 27.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA.

Diabetes is a risk factor for osteoporosis. Annatto-extracted tocotrienols (TT) have proven benefits in preserving bone matrix. Here, we evaluated the effects of dietary TT on glucose homeostasis, bone properties, and liver pro-inflammatory mRNA expression in high-fat diet (HFD)-induced type 2 diabetic (T2DM) mice. 58 male C57BL/6 J mice were divided into 5 groups: low-fat diet (LFD), HFD, HFD + 400 mgTT/kg diet (T400), HFD + 1600 mgTT/kg diet (T1600), and HFD + 200 mg metformin/kg (Met) for 14 weeks. Relative to the HFD group, both TT-supplemented groups (1) improved glucose homeostasis by lowering the area under the curve for both glucose tolerance and insulin tolerance tests, (2) increased serum procollagen I intact N-terminal propeptide (bone formation) level, trabecular bone volume/total volume, trabecular number, connectivity density, and cortical thickness, (3) decreased collagen type 1 cross-linked C-telopeptide (bone resorption) levels, trabecular separation, and structure model index, and (4) suppressed liver mRNA levels of inflammation markers including IL-2, IL-23, IFN-γ, MCP-1, TNF-α, ITGAX and F4/80. There were no differences in glucose homeostasis and liver mRNA expression among T400, T1600, and Met. The order of osteo-protective effects was LFD ≥T1600 ≥T400 = Met >HFD. Collectively, these data suggest that TT exerts osteo-protective effects in T2DM mice by regulating glucose homeostasis and suppressing inflammation.
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http://dx.doi.org/10.1038/s41598-018-29063-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6063954PMC
July 2018

Alternative splicing of helicase-like transcription factor (Hltf): Intron retention-dependent activation of immune tolerance at the feto-maternal interface.

PLoS One 2018 5;13(7):e0200211. Epub 2018 Jul 5.

Department of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, United States of America.

Hltf is regulated by intron retention, and global Hltf-deletion causes perinatal lethality from hypoglycemia. In heart, full-length Hltf is a transcriptional regulator of Hif-1α that controls transport systems. Thus, we tested the hypothesis that Hltf deletion from placenta caused or exacerbated neonatal hypoglycemia via Hif-1α regulation of nutrient transporters. RNA-seq data analyses identified significant changes in transcript expression and alternative splicing (AS) in E18.5 placentome. iPathwayGuide was used for gene ontology (GO) analysis of biological processes, molecular functions and cellular components. Elim pruning algorithm identified hierarchical relationships. The methylome was interrogated by Methyl-MiniSeq Epiquest analysis. GO analysis identified gene enrichment within biological processes. Protein expression was visualized with immunohistochemistry. Although two Hltf mRNA isoforms are quantifiable in most murine tissues, only the truncated Hltf isoform is expressed in placenta. The responsible intron retention event occurs in the absence of DNA methylation. iPathwayGuide analysis identified 157 target genes of 11,538 total genes with measured expression. These were obtained using a threshold of 0.05 for statistical significance (p-value) and a long fold change of expression with absolute value of at least 0.6. Hltf deletion altered transcription of trophoblast lineage-specific genes, and increased transcription of the Cxcr7 (p = 0.004) gene whose protein product is a co-receptor for human and simian immunodeficiency viruses. Concomitant increased Cxcr7 protein was identified with immunolabeling. Hltf deletion had no effect on transcription or site-specific methylation patterns of Hif-1α, the major glucose transporters, or System A amino acid transporters. There was no measureable evidence of uteroplacental dysfunction or fetal compromise. iPathGuide analysis revealed Hltf suppresses cytolysis (10/21 genes; p-value 1.900e-12; p-value correction: Elim pruning; GO:019835) including the perforin-granzyme pathway in uterine natural killer cells. Our findings 1) prove the truncated Hltf protein isoform is a transcription factor, 2) establish a functional link between AS of Hltf and immunosuppression at the feto-maternal interface, 3) correlate intron retention with the absence of DNA methylation, and 4) underscore the importance of differential splicing analysis to identify Hltf's functional diversity.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0200211PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6033450PMC
January 2019

Sertoli Cells Engineered to Express Insulin to Lower Blood Glucose in Diabetic Mice.

DNA Cell Biol 2018 Aug 21;37(8):680-690. Epub 2018 Jun 21.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center , Lubbock, Texas.

Long-term survival of allo- and xenotransplanted immune-privileged Sertoli cells (SCs) is well documented suggesting that SCs can be used to deliver foreign proteins for cell-based gene therapy. The aim of this study was to use a lentivirus carrying proinsulin cDNA to achieve stable expression and lowering of blood glucose levels (BGLs). A SC line transduced with the lentivirus (MSC-LV-mI) maintained stable insulin expression in vitro. These MSC-LV-mI cells were transplanted and grafts were analyzed for cell survival, continued proinsulin mRNA, and insulin protein expression. All grafts contained MSC-LV-mI cells that expressed proinsulin mRNA and insulin protein. Transplantation of MSC-LV-mI cells into diabetic mice significantly lowered BGLs for 4 days after transplantation. Interestingly, in three transplanted SCID mice and one transplanted BALB/c mouse, the BGLs again significantly lowered by day 50 and 70, respectively. This is the first time SC transduced with a lentiviral vector was able to stably express insulin and lower BGLs. In conclusion, a SC line can be modified to stably express therapeutic proteins (e.g., insulin), thus taking us one step further in the use of SCs as an immune-privileged vehicle for cell-based gene therapy.
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http://dx.doi.org/10.1089/dna.2017.3937DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6080125PMC
August 2018

An overview of a Sertoli cell transplantation model to study testis morphogenesis and the role of the Sertoli cells in immune privilege.

Environ Epigenet 2017 Jul 3;3(3):dvx012. Epub 2017 Aug 3.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.

Advanced testicular germ cells, expressing novel cell surface and intracellular proteins, appear after the establishment of central tolerance and thus are auto-immunogenic. However, due to testis immune privilege these germ cells normally do not evoke a detrimental immune response. The Sertoli cell (SC) barrier (also known as the blood-testis barrier) creates a unique microenvironment required for the completion of spermatogenesis and sequesters the majority of the advanced germ cells from the immune system. Given that an intact SC barrier is necessary for spermatogenesis and that disruption of the SC barrier results in loss of advanced germ cells independent of an immune response, this dual role of the SC barrier makes it difficult to directly test the importance of the SC barrier in immune privilege. The ability of SCs to survive and protect co-grafted cells when transplanted ectopically (outside the testis) across immunological barriers is well-documented. Here, we will discuss the use of a SC transplantation model to investigate the role of SC and the SC barrier in immune privilege. Additionally, the formation of cord/tubule like structures in this model, containing both SCs and myoid cells, further extends its application to study testis morphogenesis. We will also discuss the potential use of this model to study the effects of drugs/environmental toxins on testis morphogenesis, tight junction formation and SC-myoid cell interactions.
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http://dx.doi.org/10.1093/eep/dvx012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5804552PMC
July 2017

Effects of delta-tocotrienol on obesity-related adipocyte hypertrophy, inflammation and hepatic steatosis in high-fat-fed mice.

J Nutr Biochem 2017 10 10;48:128-137. Epub 2017 Jul 10.

Department of Nutritional Sciences, Texas Tech University, 1301 Akron Avenue, Lubbock, TX 79409; Obesity Research Cluster, Texas Tech University, 1301 Akron Avenue, Lubbock, TX 79409. Electronic address:

Inflammation is a major underlying cause for obesity-associated metabolic diseases. Hence, anti-inflammatory dietary components may improve obesity-related disorders. We hypothesized that delta-tocotrienol (δT3), a member of the vitamin E family, reduces adiposity, insulin resistance and hepatic triglycerides through its anti-inflammatory properties. To test this hypothesis, C57BL/6J male mice were fed a high-fat diet (HF) with or without supplementation of δT3 (HF+δT3) at 400 mg/kg and 1600 mg/kg for 14 weeks, and they were compared to mice fed a low-fat diet (LF) or HF supplemented with metformin as an antidiabetic control. Glucose tolerance tests were administered 2 weeks prior to the end of treatments. Histology, quantitative polymerase chain reaction and protein analyses were performed to assess inflammation and fatty acid metabolism in adipose and liver tissues. Significant improvements in glucose tolerance, and reduced hepatic steatosis and serum triglycerides were observed in δT3-supplemented groups compared to the HF group. Body and fat pad weights were not significantly reduced in HF+δT3 groups; however, we observed smaller fat cell size and reduced macrophage infiltration in their adipose tissues compared to other groups. These changes were at least in part mechanistically explained by a reduction of mRNA and protein expression of proinflammatory adipokines and increased expression of anti-inflammatory adipokines in HF+δT3 mice. Moreover, δT3 dose-dependently increased markers of fatty acid oxidation and reduced markers of fatty acid synthesis in adipose tissue and liver. In conclusion, our studies suggest that δT3 may promote metabolically healthy obesity by reducing fat cell hypertrophy and decreasing inflammation in both liver and adipose tissue.
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http://dx.doi.org/10.1016/j.jnutbio.2017.07.003DOI Listing
October 2017

The renin angiotensin system, oxidative stress and mitochondrial function in obesity and insulin resistance.

Biochim Biophys Acta Mol Basis Dis 2017 05 4;1863(5):1106-1114. Epub 2016 Aug 4.

Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, United States; Obesity Research Cluster, Texas Tech University, Lubbock, TX, United States. Electronic address:

Obesity is a complex disease characterized by excessive expansion of adipose tissue and is an important risk factor for chronic diseases such as cardiovascular disorders, hypertension and type 2 diabetes. Moreover, obesity is a major contributor to inflammation and oxidative stress, all of which are key underlying causes for diabetes and insulin resistance. Specifically, adipose tissue secretes bioactives molecules such as inflammatory hormone angiotensin II, generated in the Renin Angiotensin System (RAS) from its precursor angiotensinogen. Accumulated evidence suggests that RAS may serve as a strong link between obesity and insulin resistance. Dysregulation of RAS also occurs in several other tissues including those involved in regulation of glucose and whole body homeostasis as well as insulin sensitivity such as muscle, liver and pancreas and heart. Here we review the scientific evidence for these interactions and potential roles for oxidative stress, inflammation and mitochondrial dysfunction in these target tissues which may mediate effects of RAS in metabolic diseases. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.
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http://dx.doi.org/10.1016/j.bbadis.2016.07.019DOI Listing
May 2017

Xenotransplanted Pig Sertoli Cells Inhibit Both the Alternative and Classical Pathways of Complement-Mediated Cell Lysis While Pig Islets Are Killed.

Cell Transplant 2016 11;25(11):2027-2040

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA.

Xenotransplantation has vast clinical potential but is limited by the potent immune responses generated against xenogeneic tissue. Immune-privileged Sertoli cells (SCs) survive xenotransplantation long term (≥90 days) without immunosuppression, making SCs an ideal model to identify xenograft survival mechanisms. Xenograft rejection includes the binding of natural and induced antibodies and the activation of the complement cascade. Using an in vitro cytotoxicity assay, wherein cells were cultured with human serum and complement, we demonstrated that neonatal pig SCs (NPSCs) are resistant to complement-mediated cell lysis and express complement inhibitory factors, membrane cofactor protein (MCP; CD46), and decay- accelerating factor (DAF; CD55) at significantly higher levels than neonatal pig islets (NPIs), which served as non-immune-privileged controls. After xenotransplantation into naive Lewis rats, NPSCs survived throughout the study, while NPIs were rejected within 9 days. Serum antibodies, and antibody and complement deposition within the grafts were analyzed. Compared to preformed circulating anti-pig IgM antibodies, no significant increase in IgM production against NPSCs or NPIs was observed, while IgM deposition was detected from day 6 onward in both sets of grafts. A late serum IgG response was detected in NPSC (days 13 and 20) and NPI (day 20) recipients. Consistently, IgG deposition was first detected at days 9 and 13 in NPSC and NPI grafts, respectively. Interestingly, C3 was deposited at days 1 and 3 in NPI grafts and only at day 1 in NPSC grafts, while membrane attack complex (MAC) deposition was only detected in NPI grafts (at days 1-4). Collectively, these data suggest NPSCs actively inhibit both the alternative and classical pathways of complement-mediated cell lysis, while the alternative pathway plays a role in rejecting NPIs. Ultimately, inhibiting the alternative pathway along with transplanting xenogeneic tissue from transgenic pigs (expressing human complement inhibitory factors) could prolong the survival of xenogeneic cells without immunosuppression.
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http://dx.doi.org/10.3727/096368916X692032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6126928PMC
November 2016

Sustained expression of insulin by a genetically engineered sertoli cell line after allotransplantation in diabetic BALB/c mice.

Biol Reprod 2014 May 2;90(5):109. Epub 2014 Apr 2.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas

Immune-privileged Sertoli cells (SCs) exhibit long-term survival after allotransplantation or xenotransplantation, suggesting they can be used as a vehicle for cell-based gene therapy. Previously, we demonstrated that SCs engineered to secrete insulin by using an adenoviral vector normalized blood glucose levels in diabetic mice. However, the expression of insulin was transient, and the use of immunocompromised mice did not address the question of whether SCs can stably express insulin in immunocompetent animals. Thus, the objective of the current study was to use a lentiviral vector to achieve stable expression of insulin in SCs and test the ability of these cells to survive after allotransplantation. A mouse SC line transduced with a recombinant lentiviral vector containing furin-modified human proinsulin cDNA (MSC-EhI-Zs) maintained stable insulin expression in vitro. Allotransplantation of MSC-EhI-Zs cells into diabetic BALB/c mice demonstrated 88% and 75% graft survival rates at 20 and 50 days post-transplantation, respectively. Transplanted MSC-EhI-Zs cells continued to produce insulin mRNA throughout the study (i.e., 50 days); however, insulin protein was detected only in patches of cells within the grafts. Consistent with low insulin protein detection, there was no significant change in blood glucose levels in the transplant recipients. Nevertheless, MSC-EhI-Zs cells isolated from the grafts continued to express insulin protein in culture. Collectively, this demonstrates that MSC-EhI-Zs cells stably expressed insulin and survived allotransplantation without immunosuppression. This further strengthens the use of SCs as targets for cell-based gene therapy for the treatment of numerous chronic diseases, especially those that require basal protein expression.
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http://dx.doi.org/10.1095/biolreprod.113.115600DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4076370PMC
May 2014

Sertoli cells--immunological sentinels of spermatogenesis.

Semin Cell Dev Biol 2014 Jun 3;30:36-44. Epub 2014 Mar 3.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, United States. Electronic address:

Testicular germ cells, which appear after the establishment of central tolerance, express novel cell surface and intracellular proteins that can be recognized as 'foreign antigens' by the host's immune system. However, normally these germ cells do not evoke an auto-reactive immune response. The focus of this manuscript is to review the evidence that the blood-testis-barrier (BTB)/Sertoli cell (SC) barrier along with the SCs ability to modulate the immune response is vital for protecting auto-antigenic germ cells. In normal testis, the BTB/SC barrier protects the majority of the auto-antigenic germ cells by limiting access by the immune system and sequestering these 'new antigens'. SCs also modulate testis immune cells (induce regulatory immune cells) by expressing several immunoregulatory factors, thereby creating a local tolerogenic environment optimal for survival of nonsequesetred auto-antigenic germ cells. Collectively, the fortress created by the BTB/SC barrier along with modulation of the immune response is pivotal for completion of spermatogenesis and species survival.
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http://dx.doi.org/10.1016/j.semcdb.2014.02.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4043859PMC
June 2014

Nondividing, postpubertal rat sertoli cells resumed proliferation after transplantation.

Biol Reprod 2014 Jan 23;90(1):13. Epub 2014 Jan 23.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas.

Conventionally, it was believed that Sertoli cells (SC) stopped proliferating at puberty and became terminally differentiated quiescent cells. However, recent studies have challenged that dogma. In this study, we transplanted nondividing SC isolated from 23- to 27-day-old postpubertal rats transduced with a recombinant adenoviral vector (containing furin-modified human proinsulin cDNA) into diabetic severe combined immunodeficiency mice. Immunostaining the grafts for cell proliferation markers, proliferating cell nuclear antigen (PCNA) and MKI67, revealed that transplanted SC within the grafts were proliferating. Possible causes for resumption of proliferation of SC could be viral transduction, cell isolation and culture, higher abdominal temperature at the transplant site, and/or transplantation. To test for these possible causes, double- immunofluorescence staining was performed for GATA4 (SC marker) and MKI67. None of the SC were positive for MKI67 in tissue collected during SC isolation and culture or at higher temperature. However, nontransduced SC stained positive for MKI67 after transplantation into rats, suggesting viral transduction was not a key factor for induction of SC proliferation. Interestingly, resumption in proliferative ability of nondividing SC was temporary, as SC stopped proliferating within 14 days of transplantation and did not proliferate thereafter. Quantification of 5-bromo-2'-deoxyuridine-labeled SC demonstrated that 7%-9% of the total transplanted SC were proliferating in the grafts. These data indicate for the first time that nondividing SC resumed proliferation after transplantation and further validate previous findings that SC are not terminally differentiated. Hence, transplantation of SC could provide a useful model with which to study the regulation of SC proliferation in vivo.
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http://dx.doi.org/10.1095/biolreprod.113.110197DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4076399PMC
January 2014

Blood-tissue barriers: morphofunctional and immunological aspects of the blood-testis and blood-epididymal barriers.

Adv Exp Med Biol 2012 ;763:237-59

Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.

The blood-testis barrier (BTB) is known for its ability to create an immune privilege site in the seminiferous epithelium, but less is known of the blood-epididymal barrier (BEB). It is already established that the fully functional BTB and BEB are much more complex and consist of anatomical/physical (tight junctions, basolateral and apical membranes), physiological and immunological components, which are all necessary to make a functioning barrier in the testis and epididymis. However, comparative data for metazoans suggest that an effective Sertoli cell barrier is not entirely necessary for the development of germ cells during spermatogenesis or that our knowledge about the barrier structure/function in metazoans is still immature. This chapter compares the unique barrier formed by the Sertoli cells of the testis to that formed by the apical junctional complexes of the epididymal epithelium.
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April 2013

Genetically engineered immune privileged Sertoli cells: A new road to cell based gene therapy.

Spermatogenesis 2012 Jan;2(1):23-31

Sertoli cells are immune privileged cells, important for controlling the immune response to male germ cells as well as maintaining the tolerogenic environment in the testis. Additionally, ectopic Sertoli cells have been shown to survive and protect co-grafted cells when transplanted across immunological barriers. The survival of ectopic Sertoli cells has led to the idea that they could be used in cell based gene therapy. In this review, we provide a brief overview of testis immune privilege and Sertoli cell transplantation, factors contributing to Sertoli cell immune privilege, the challenges faced by viral vector gene therapy, the use of immune privileged cells in cell based gene therapy and describe several recent studies on the use of genetically engineered Sertoli cells to provide continuous delivery of therapeutic proteins.
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http://dx.doi.org/10.4161/spmg.19119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3341243PMC
January 2012

Cell lines: Valuable tools or useless artifacts.

Spermatogenesis 2012 Jan;2(1):1-5

Department of Cell Biology and Biochemistry; Texas Tech University Health Sciences Center; Lubbock, TX USA.

Cell lines are often used in place of primary cells to study biological processes. However, care must be taken when interpreting the results as cell lines do not always accurately replicate the primary cells. In this article, we will briefly talk about advantages and disadvantages of cell lines and then discuss results using the mouse Sertoli cell line, MSC-1, compared with primary mouse Sertoli cells. MSC-1 cells resemble Sertoli cells morphologically and possess several biochemical markers associated with Sertoli cells. Studies have demonstrated that the function and regulation of retinoic acid receptor α (RARα) is similar between MSC-1 and rat Sertoli cells. However, MSC-1 cells lack some of the immune privilege properties associated with primary Sertoli cells, including survival in animals with a fully functional immune system. Therefore, it has to be kept in mind that cell lines do not behave identically with primary cells and should not be used to replace primary cells. In order to strengthen the findings, key control experiments using primary cells should always be performed.
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http://dx.doi.org/10.4161/spmg.19885DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3341241PMC
January 2012

Immunoprotective properties of primary Sertoli cells in mice: potential functional pathways that confer immune privilege.

Biol Reprod 2012 Jan 10;86(1):1-14. Epub 2012 Jan 10.

Center for Reproductive Biology, School of Molecular Biosciences, Washington State University, Pullman, USA.

Primary Sertoli cells isolated from mouse testes survive when transplanted across immunological barriers and protect cotransplanted allogeneic and xenogeneic cells from rejection in rodent models. In contrast, the mouse Sertoli cell line (MSC-1) lacks immunoprotective properties associated with primary Sertoli cells. In this study, enriched primary Sertoli cells or MSC-1 cells were transplanted as allografts into the renal subcapsular area of naive BALB/c mice, and their survival in graft sites was compared. While Sertoli cells were detected within the grafts with 100% graft survival throughout the 20-day study, MSC-1 cells were rejected between 11 and 14 days, with 0% graft survival at 20 days posttransplantation. Nonetheless, the mechanism for primary Sertoli cell survival and immunoprotection remains unresolved. To identify immune factors or functional pathways potentially responsible for immune privilege, gene expression profiles of enriched primary Sertoli cells were compared with those of MSC-1 cells. Microarray analysis identified 2369 genes in enriched primary Sertoli cells that were differentially expressed at ±4-fold or higher levels than in MSC-1 cells. Ontological analyses identified multiple immune pathways, which were used to generate a list of 340 immune-related genes. Three functions were identified in primary Sertoli cells as potentially important for establishing immune privilege: suppression of inflammation by specific cytokines and prostanoid molecules, slowing of leukocyte migration by controlled cell junctions and actin polymerization, and inhibition of complement activation and membrane-associated cell lysis. These results increase our understanding of testicular immune privilege and, in the long-term, could lead to improvements in transplantation success.
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http://dx.doi.org/10.1095/biolreprod.110.089425DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3313662PMC
January 2012

The blood-testis and blood-epididymis barriers are more than just their tight junctions.

Biol Reprod 2011 May 5;84(5):851-8. Epub 2011 Jan 5.

Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.

The terms blood-testis barrier (BTB) or blood-epididymis barrier (BEB), are often described as Sertoli cell-Sertoli cell tight junctions (TJs) or TJs between the epithelial cells in the epididymis, respectively. However, in reality, the BTB and BEB are much more complex than just the TJ. The focus of this minireview is to remind readers that the complete BTB and BEB are comprised of three components: anatomical, physiological, and immunological. The TJs form the anatomical (physical) barrier that restricts passage of molecules and cells from entering or exiting the lumen. The physiological barrier is comprised of transporters that regulate movement of substances in or out of the lumen, thus creating a microenvironment, which is critical for the proper development and maturation of germ cells. The immunological barrier limits access by the immune system and sequesters the majority of the autoantigenic germ cells. Combined with the overall immune-privilege of the testis, this suppresses detrimental immune responses against the autoantigenic germ cells. These three components on their own do not create a complete functional barrier; instead, it is the interaction between all three components that create a barrier of maximal competence.
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http://dx.doi.org/10.1095/biolreprod.110.087452DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4574632PMC
May 2011

Delivery of a therapeutic protein by immune-privileged Sertoli cells.

Cell Transplant 2010 17;19(12):1645-57. Epub 2010 Aug 17.

Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.

Immune-privileged Sertoli cells survive long term after allogeneic or xenogeneic transplantation without the use of immunosuppressive drugs, suggesting they could be used as a vehicle to deliver therapeutic proteins. As a model to test this, we engineered Sertoli cells to transiently produce basal levels of insulin and then examined their ability to lower blood glucose levels after transplantation into diabetic SCID mice. Mouse and porcine Sertoli cells transduced with a recombinant adenoviral vector containing furin-modified human proinsulin cDNA expressed insulin mRNA and secreted insulin protein. Transplantation of 5-20 million insulin-expressing porcine Sertoli cells into diabetic SCID mice significantly decreased blood glucose levels in a dose-dependent manner, with 20 million Sertoli cells decreasing blood glucose levels to 9.8 ± 2.7 mM. Similar results were obtained when 20 million insulin-positive, BALB/c mouse Sertoli cells were transplanted; blood glucose levels dropped to 6.3 ± 2.4 mM and remained significantly lower for 5 days. To our knowledge, this is the first study to demonstrate Sertoli cells can be engineered to produce and secrete a clinically relevant factor that has a therapeutic effect, thus supporting the concept of using immune-privileged Sertoli cells as a potential vehicle for gene therapy.
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http://dx.doi.org/10.3727/096368910X516628DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3087628PMC
June 2011

Immunoprotective sertoli cells: making allogeneic and xenogeneic transplantation feasible.

Reproduction 2010 Mar 8;139(3):495-504. Epub 2009 Dec 8.

Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA.

The testis as an immune-privileged site allows long-term survival of allogeneic and xenogeneic transplants. Testicular Sertoli cells (SCs) play a major role in this immunoprotection and have been used to create an ectopic immune-privileged environment that prolongs survival of co-transplanted allogeneic and xenogeneic cells, including pancreatic islets and neurons. Extended survival of such grafts testifies to the immunoprotective properties of SCs. However, there is still variability in the survival rates of the co-grafted cells and rarely are 100% of the grafts protected. This emphasizes the need to learn more about what is involved in creating the optimal immunoprotective milieu. Several parameters including organization of the SCs into tubule-like structures and the production of immunomodulatory factors by SCs, specifically complement inhibitors, cytokines, and cytotoxic lymphocyte inhibitors, are likely important. In addition, an intricate interplay between several of these factors may be responsible for providing the most ideal environment for protection of the co-transplants by SCs. In this review, we will also briefly describe a novel use for the immune-privileged abilities of SCs; engineering them to deliver therapeutic proteins for the treatment of diseases like diabetes and Parkinson's disease. In conclusion, further studies and more detailed analysis of the mechanisms involved in creating the immune-protective environment by SCs may make their application in co-transplantation and as engineered cells clinically feasible.
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http://dx.doi.org/10.1530/REP-09-0384DOI Listing
March 2010

Sertoli cell line lacks the immunoprotective properties associated with primary Sertoli cells.

Cell Transplant 2008 ;17(5):525-34

Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.

Sertoli cells are important for maintenance of the immune privileged environment of the testis and prolong survival of cotransplanted cells. The objective of the current study was to examine the immunoprotective properties of a mouse Sertoli cell line (MSC-1) in order to identify a Sertoli cell line that could be used to aid in investigation of the immunoprotective abilities of Sertoli cells. BALB/c islets were cotransplanted with 0-9 million primary BALB/c Sertoli cells or MSC-1 cells into diabetic C3H or BALB/c mice and protection of grafted islets was examined by monitoring blood glucose levels and immunohistochemical analysis. Additionally, expression of potential immunoprotective factors in MSC-1 cells was examined. Cotransplantation of islets with 3 million primary Sertoli cells significantly prolonged islet allograft survival (61.1 +/- 6.9 days; p < 0.05) compared with control mice that received allogeneic islets alone (26.9 +/- 2.1 days). Grafts collected from normoglycemic C3H mice at 100 days posttransplant contained insulin-positive beta-cells adjacent to allogeneic Sertoli cells arranged in tubule-like structures. In contrast, cotransplantation of islet allografts with MSC-1 cells did not prolong islet survival (average 29.8 +/- 3.3 days) regardless of the number of MSC-1 cells transplanted and the rejected grafts contained very few beta-cells and randomly arranged MSC-1 cells. The lack of islet cell survival was not due to detrimental effects of MSC-1 cells because syngneic islets cotransplanted with MSC-1 cells were functional throughout the study. MSC-1 cells were found to express known Sertoli cell-expressed, immunoprotective factors, clusterin, Fas ligand, and transforming growth factor-beta1, suggesting additional factors may be involved in Sertoli cell immune privilege. These data indicate the MSC-1 cell line lacks the immunoprotective properties associated with primary Sertoli cells. Further study of this cell line could be useful in examining the mechanisms that enable Sertoli cells to provide immune privilege.
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http://dx.doi.org/10.3727/096368908785096033DOI Listing
January 2009

Comparison of successful and unsuccessful islet/Sertoli cell cotransplant grafts in streptozotocin-induced diabetic mice.

Cell Transplant 2008 ;16(10):1029-38

Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.

Sertoli cells (SC) protect islet allografts from immune destruction in diabetic rodents. In this study, we examined the difference between successful and rejected islet/SC cografts in order to further improve this procedure for optimal extension of islet allograft survival. We cotransplanted 500 BALB/c islets with 1-8 million BALB/c SC under the kidney capsule of diabetic BALB/c, C3H-HeJ, and C57BL/6 mice. Cotransplantation of islets with up to 8 million SC was not detrimental to long-term islet graft function in syngeneic mice. However, large numbers of SC were detrimental to islet graft survival in allogeneic mice with the optimal dose for cotransplantation of 4 or 1 million SC in C3H-HeJ or C57BL/6 mice, respectively. Examination of successful grafts, from euglycemic recipients, revealed the presence of SC arranged in tubule structures with islets surrounding these tubules. Cellular infiltrate in successful grafts revealed CD4 T cells and macrophages along the periphery and within the grafts, and very few CD8 T cells. Conversely, examination of unsuccessful grafts, harvested from hyperglycemic recipients at the time of rejection, revealed the presence of SC arranged randomly with islets adjacent to the Sertoli cells, when present, and massive CD4 and CD8 T cell as well as macrophage cell infiltration. Prolongation of islet allograft survival appeared to be a function of SC transplant mass and recipient genetic background. A consequence of long-term graft acceptance is the formation of SC tubule structures, which may be an additional requirement for optimal protection of islet allografts.
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July 2008