Association of a single nucleotide polymorphism in SOD2 with susceptibility for the development of diabetic nephropathy in patients with type 2 diabetes: A Saudi population study.

INTRODUCTION: One of the complications of diabetes mellitus (DM) is diabetic nephropathy (DN), which plays a significant role in the progression of end-stage renal disease. Oxidative stress is implicated in DN pathogenesis, and genetic variations in antioxidant enzymes such as superoxide dismutase 2 (SOD2) and catalase (CAT) may contribute to the susceptibility. This study aimed to investigate the potential association between single nucleotide polymorphisms (SNPs) in antioxidant enzymes, specifically SOD2 rs4880 and CAT rs769217, and the risk of T2D and susceptibility to DN within the Saudi population. METHODS: This case-control study included 150 participants, comprising 50 patients with T2D without DN (group 1), 50 patients with T2D with DN (group 2), and 50 healthy participants (group 3). The samples were genotyped using real-time PCR for SOD2 rs4880 and CAT rs769217 SNPs. Sanger sequencing was used for validation. Statistical analyses were performed to explore associations between these SNPs and T2D with or without DN. RESULTS: No significant difference was observed in CAT rs769217 expression between the groups. However, a significant difference was observed in SOD2 rs4880 expression between the healthy controls and patients with T2D with DN (p = .028). Furthermore, SOD2 rs4880 was associated with approximately threefold increased risk of DN in patients with T2D compared to that in healthy participants (odds ratio [OR] = 2.99 [1.31-6.83]). Validation through Sanger sequencing further confirmed these findings. CONCLUSIONS: The findings of this study provide evidence that SOD2 rs4880 SNP may contribute to inadequate defence by the antioxidant enzyme, SOD2, against DM-induced oxidative stress and thus cause DN in Saudi patients with T2D. Therefore, SOD2 rs4880 may serve as a predictive marker to prevent the development and progression of DN in patients with T2D.

Analysis of global DNA methylation and epigenetic modifiers (DNMTs and HDACs) in human foetal endothelium exposed to gestational and type 2 diabetes.

Foetuses exposed to maternal gestational diabetes (GDM) and type 2 diabetes (T2D) have an increased risk of adverse perinatal outcomes. Epigenetic mechanisms, including DNA methylation and histone modifications, may act as mediators of persistent metabolic memory in endothelial cells (ECs) exposed to hyperglycaemia, even after glucose normalization. Therefore, we investigated alterations in global DNA methylation and epigenetic modifier expression (DNMT1, DNMT3a, DNMT3b, HDAC1, and HDAC2) in human umbilical vein ECs (HUVECs) from the umbilical cords of mothers with GDM (n = 8) and T2D (n = 3) compared to that of healthy mothers (n = 6). Global DNA alteration was measured using a 5-methylation cytosine colorimetric assay, followed by quantitative real-time polymerase chain reaction to measure DNA methyltransferase and histone acetylase transcript expression. We revealed that DNA hypermethylation occurs in both GDM- and T2D-HUVECs compared to that in Control-HUVECs. Furthermore, there was a significant increase in HDAC2 mRNA levels in GDM-HUVECs and increase in DNMT3b mRNA levels in T2D-HUVECs. Overall, our results suggest that GDM and T2D are associated with global DNA hypermethylation in foetal endothelial cells under normoglycemic conditions and the aberrant mRNA expression of HDAC2 and DNMT3b could play a role in this dysregulation.

Global DNA hypermethylation was reported in foetal endothelial cells of both gestational and type 2 diabetes cultured under normal glucose conditionHDAC2 mRNA was significantly increased in gestational diabetesDNMT3b mRNA was significantly increased in type 2 diabetesOur data support the concept of epigenetic programming occurs in foetal endothelial cells exposed to diabetes which retain even after glucose normalization.

Stem-Cell-Based Therapy: The Celestial Weapon against Neurological Disorders.

Stem cells are a versatile source for cell therapy. Their use is particularly significant for the treatment of neurological disorders for which no definitive conventional medical treatment is available. Neurological disorders are of diverse etiology and pathogenesis. Alzheimer's disease (AD) is caused by abnormal protein deposits, leading to progressive dementia. Parkinson's disease (PD) is due to the specific degeneration of the dopaminergic neurons causing motor and sensory impairment. Huntington's disease (HD) includes a transmittable gene mutation, and any treatment should involve gene modulation of the transplanted cells. Multiple sclerosis (MS) is an autoimmune disorder affecting multiple neurons sporadically but induces progressive neuronal dysfunction. Amyotrophic lateral sclerosis (ALS) impacts upper and lower motor neurons, leading to progressive muscle degeneration. This shows the need to try to tailor different types of cells to repair the specific defect characteristic of each disease. In recent years, several types of stem cells were used in different animal models, including transgenic animals of various neurologic disorders. Based on some of the successful animal studies, some clinical trials were designed and approved. Some studies were successful, others were terminated and, still, a few are ongoing. In this manuscript, we aim to review the current information on both the experimental and clinical trials of stem cell therapy in neurological disorders of various disease mechanisms. The different types of cells used, their mode of transplantation and the molecular and physiologic effects are discussed. Recommendations for future use and hopes are highlighted.

Aberrant expression of proatherogenic cytokines and growth factors in human umbilical vein endothelial cells from newborns of type 2 diabetic women.

OBJECTIVES: This study reports the levels of cytokines, chemokines, and growth factors previously identified as taking part in the pathology of atherosclerosis in human umbilical vein endothelial cells derived from mothers with type 2 diabetes and compares them with those in human umbilical vein endothelial cells derived from healthy mothers under normal glucose conditions. METHODS: Cytokine analysis measures of human umbilical vein endothelial cell lysates were obtained using a multiple analyte profiling (xMAP) assay based on magnetic bead-based technology, using the MAGPIX instrument. The correlation between cytokines, chemokines, and growth factors was examined statistically in human umbilical vein endothelial cells derived from mothers with type 2 diabetes. RESULTS: This study showed that the expression of proinflammatory cytokine interleukin-1 alpha was significantly greater in human umbilical vein endothelial cells derived from mothers with type 2 diabetes than those derived from healthy mothers. The protein level of granulocyte colony-stimulating factor was higher in human umbilical vein endothelial cells derived from mothers with type 2 diabetes than those derived from healthy mothers. A significant positive correlation was demonstrated between the protein expression of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor in human umbilical vein endothelial cells derived from mothers with type 2 diabetes. CONCLUSION: Diabetes evokes a persistent inflammatory phenotype in human umbilical vein endothelial cells, as indicated by the enhanced production of cytokines and growth factors under normal glucose conditions.

Alterations of transcriptome expression, cell cycle, and mitochondrial superoxide reveal foetal endothelial dysfunction in Saudi women with gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) affects one in four Saudi women and is associated with high risks of cardiovascular diseases in both the mother and foetus. It is believed that endothelial cells (ECs) dysfunction initiates these diabetic complications. In this study, differences in the transcriptome profiles, cell cycle distribution, and mitochondrial superoxide (MTS) between human umbilical vein endothelial cells (HUVECs) from GDM patients and those from healthy (control) subjects were analysed. Transcriptome profiles were generated using high-density expression microarray. The selected four altered genes were validated using qRT-PCR. MTS and cell cycle were analysed by flow cytometry. A total of 84 altered genes were identified, comprising 52 upregulated and 32 downregulated genes in GDM.HUVECs. Our selection of the four interested altered genes (TGFB2, KITLG, NEK7, and IGFBP5) was based on the functional network analysis, which revealed that these altered genes are belonging to the highest enrichment score associated with cellular function and proliferation; all of which may contribute to ECs dysfunction. The cell cycle revealed an increased percentage of cells in the G2/M phase in GDM.HUVECs, indicating cell cycle arrest. In addition, we found that GDM.HUVECs had increased MTS generation. In conclusion, GDM induces persistent impairment of the biological functions of foetal ECs, as evidenced by analyses of transcriptome profiles, cell cycle, and MTS even after ECs culture in vitro for several passages under normal glucose conditions.

Antileukemic activity of sulfoxide nutraceutical allicin against THP-1 cells is associated with premature phosphatidylserine exposure in human erythrocytes.

BACKGROUND: Allicin (ACN), a sulfoxide in freshly crushed garlic, is known for its diverse bioactive properties. Among the most notable effects of ACN is its antitumor activity against a wide array of cancer types. Thus, ACN may be a promising anticancer therapeutic. Nevertheless, chemotherapy-induced anemia is a major obstacle in cancer management with a prevalence of up to 70%. Although the pathophysiology behind it remains elusive, a number of medications known to cause anemia in patients have been shown to induce premature programmed cell death in red blood cells (RBCs) known as eryptosis. This study, thus, investigates the anticancer potential of ACN against THP-1 monocytic leukemia cells, its toxic effects on human RBCs, and delineate the underlying biochemical mechanisms. METHODS: Cytotoxicity was detected using the MTT assay, while hemoglobin leakage was used as a surrogate for hemolysis which was photometrically measured. Major eryptotic events were examined using flow cytometry with fluorescent probes. Phosphatidylserine (PS) exposure was detected by Annexin-V-FITC, cytosolic calcium with Fluo4/AM, and reactive oxygen species with H2DCFDA. RESULTS: Our results show that ACN induces hemolysis in a dose-dependent fashion, which is significantly abrogated in absence of extracellular calcium. Moreover, ACN stimulates PS exposure, intracellular calcium overload, and oxidative stress. Using small-molecule inhibitors, we demonstrate that the pro-eryptotic activity of ACN is ameliorated in presence of zVAD(OMe)-FMK, SB203580, and D4476. CONCLUSION: ACN possesses both hemolytic and eryptotic properties mediated through elevated intracellular calcium levels, oxidative stress, caspase, p38 MAPK, and CK1α.

The expression of sirtuins, superoxide dismutase, and lipid peroxidation status in peripheral blood from patients with diabetes and hypothyroidism.

BACKGROUND: Sirtuin 1 (SIRT1) and sirtuin 3 (SIRT3) proteins have an important role in counteracting oxidative stress. Although diabetes and hypothyroidism (HT) are both characterized by oxidative stress, the mechanisms are not fully understood. This study investigated the effects of type 1 diabetes (T1D), type 2 diabetes (T2D), and HT on the expression levels of SIRT1, SIRT3, and manganese superoxide dismutase (SOD2). METHODS: Gene expression of SIRT1, SIRT3, and SOD2 was measured using real-time PCR. The protein expression of SOD2 and lipid peroxidation (thiobarbituric acid reactive substances) was measured by the TBARS Assay kit and enzyme-linked immunosorbent assay (ELISA) respectively. RESULTS: The results showed that the SIRT1 and SIRT3 levels were lower in peripheral blood samples from patients with T1D, T2D, or HT than in healthy individuals. Interestingly, the mRNA and protein expression levels of SOD2 were higher in all three patient groups. Lipid peroxidation was higher in the patients with HT than in the healthy individuals. CONCLUSIONS: These results indicate alterations in the expression levels of sirtuins and superoxide dismutase in diabetes and HT, which may be related, at least in part, to the oxidative stress. Identifying such alterations in those patients will pave the way towards the development of drugs to enhance SIRT1 and SIRT3 expression and their activity to prevent the damaging effect of oxidative stress.

The effect of maternal type 2 diabetes on fetal endothelial gene expression and function.

AIMS: Maternal type 2 diabetes (T2D) can result in adverse pathological outcomes to both the mother and fetus. The present study aimed to investigate the pathological effects of maternal T2D on the gene expression patterns and functions of fetal human umbilical vein endothelial cells (HUVECs), a representative of fetal vascular cells. METHODS: Cell proliferation, apoptosis, mitochondrial ROS production and cell cycle were measured using flowcytometry. Genome-wide expression was measured using Affymetrix microarray. Gene expression of CCND2, STAT1, ITGB8, ALDH2, and ADAMTS5 was measured using real-time PCR. RESULTS: HUVECs derived from T2D mothers (T2D-HUVECs) showed elevated levels of mitochondrial superoxide anions, reduced cell proliferation, and increased apoptosis rates relative to HUVECs derived from healthy control mothers (C.HUVECs). In addition , T2D-HUVECs showed a decreased proportion of cells in G0/G1 and cell cycle arrest at the S phases relative to controls. Interestingly, microarray experiments revealed significant differences in genome-wide expression profiles between T2D-HUVECs and C.HUVECs. In particular, the analysis identified 90 upregulated genes and 42 downregulated genes. The upregulated genes CCND2, STAT1, ITGB8, ALDH2, and ADAMTS5 were validated as potential biomarkers for fetal endothelial dysfunction. Functional network analysis revealed that these genes are the important players that participate in the pathogenesis of endothelial dysfunction, which in turn influences the inflammatory response, cellular movement, and cardiovascular system development and function. CONCLUSION: Sustained alterations in the overall function of T2D-HUVEC and gene expression profiles provided insights into the role of maternal T2D on the pathophysiology of the fetal endothelial dysfunction.

The postpartum effect of maternal diabetes on the circulating levels of sirtuins and superoxide dismutase.

Gestational diabetes mellitus (GDM) is a glucose intolerance disorder which occurs during pregnancy as a result of insulin insensitivity; it usually disappears after delivery. However, some women with GDM can develop type 2 diabetes (T2D) after delivery, and the mechanisms by which this occurs remain unknown. This study compared the levels of sirtuins (NAD-dependent deacetylases) and antioxidative enzymes in postpartum women with previous GDM (pGDM) or T2D and in postpartum women with a previous healthy pregnancy (controls). Women with pGDM showed upregulated levels of sirtuin 1 (SIRT1) mRNA and protein, with reduced expression levels of sirtuin 3 (SIRT3) and superoxide dismutase 2 (SOD2), relative to the controls. Women with T2D similarly showed a lower level of SIRT3 mRNA than the controls. Lipid peroxidation (malondialdehyde) was higher in women with pGDM than in the controls. These data show that in women with pGDM, the reduced level of SIRT3 may play a role in the reduced SOD2 level, possibly leading to oxidative stress, which, in turn, upregulates the level of SIRT1. These results might confer the risk of future diabetes development in women with pGDM, as a similar reduction in SIRT3 was found in women with T2D.

The Role of Maternal Gestational Diabetes in Inducing Fetal Endothelial Dysfunction.

Gestational diabetes mellitus (GDM) is known to be associated with fetal endothelial dysfunction, however, the mechanisms are not fully understood. This study examines the effect of maternal diabetes on fetal endothelial function and gene expression under physiological glucose conditions (5 mM). Human umbilical vein endothelial cell (HUVEC) isolated from diabetic mothers (d.HUVEC) grew more slowly than HUVEC isolated from healthy mothers (c.HUVEC) and had delayed doubling time despite increased levels of total vascular endothelial growth factor (VEGF) expression and protein production as determined by real-time PCR and ELISA respectively. Using western blot, the levels of antiproliferative VEGF165b isoform were increased in d.HUVEC relative to c.HUVEC. Successful VEGF165b knockdown by small interfering RNA (siRNA) resulted in increased proliferation of d.HUVEC measured by MTT, compared with negative siRNA control, to similar levels measured in c.HUVEC. In addition, d.HUVEC generated excess levels of ROS as revealed by 2',7' Dichlorodihydrofluorescein Diacetate (DCFH-DA) and Nitrotetrazolium blue (NBT). Using microarray, 102 genes were differentially overexpressed between d.HUVEC versus c.HUVEC (>1.5-fold change; P < 0.05). Functional clustering analysis of these differentially expressed genes revealed participation in inflammatory responses (including adhesion) which may be related to pathological outcomes. Of these genes, ICAM-1 was validated as upregulated, confirming microarray results. Additional confirmatory immunofluorescence staining revealed increased protein expression of ICAM-1 compared with c.HUVEC which was reduced by vitamin C treatment (100 µM). Thus, maternal diabetes induces persistent alterations in fetal endothelial function and gene expression following glucose normalization and antioxidant treatment could help reverse endothelium dysfunction.