Fatima Ali

Mesenchymal stem cells conditioned with glucose depletion augments their ability to repair‐infarcted myocardium

Mesenchymal stem cells (MSCs) are an attractive candidate for autologous cell therapy, but their ability to repair damaged myocardium is severely compromised with advanced age. Development of viable autologous cell therapy for treatment of heart failure in the elderly requires the need to address MSC ageing. In this study, MSCs from young (2 months) and aged (24 months) C57BL/6 mice were characterized for gene expression of IGF‐1, FGF‐2, VEGF, SIRT‐1, AKT, p16INK4a, p21 and p53 along with measurements of population doubling (PD), superoxide dismutase (SOD) activity and apoptosis. Aged MSCs displayed senescent features compared with cells isolated from young animals and therefore were pre‐conditioned with glucose depletion to enhance age affected function. Pre‐conditioning of aged MSCs led to an increase in expression of IGF‐1, AKT and SIRT‐1 concomitant with enhanced viability, proliferation and delayed senescence. To determine the myocardial repair capability of pre‐conditioned aged MSCs, myocardial infarction (MI) was induced in 24 months old C57BL/6 wild type mice and GFP expressing untreated and pre‐conditioned aged MSCs were transplanted. Hearts transplanted with pre‐conditioned aged MSCs showed increased expression of paracrine factors, such as IGF‐1, FGF‐2, VEGF and SDF‐1α. This was associated with significantly improved cardiac performance as measured by dp/dtmax, dp/dtmin, LVEDP and LVDP, declined left ventricle (LV) fibrosis and apoptosis as measured by Massons Trichrome and TUNEL assays, respectively, after 30 days of transplantation. In conclusion, pre‐conditioning of aged MSCs with glucose depletion can enhance proliferation, delay senescence and restore the ability of aged cells to repair senescent infarcted myocardium.

Preconditioning diabetic mesenchymal stem cells with myogenic medium increases their ability to repair diabetic heart

IntroductionMesenchymal stem cells (MSCs) have the potential for treatment of diabetic cardiomyopathy; however, the repair capability of MSCs declines with age and disease. MSCs from diabetic animals exhibit impaired survival, proliferation, and differentiation and therefore require a strategy to improve their function. The aim of the study was to develop a preconditioning strategy to augment the ability of MSCs from diabetes patients to repair the diabetic heart.MethodsDiabetes was induced in C57BL/6 mice (6 to 8 weeks) with streptozotocin injections (55 mg/kg) for 5 consecutive days. MSCs isolated from diabetic animals were preconditioned with medium from cardiomyocytes exposed to oxidative stress and high glucose (HG/H-CCM).ResultsGene expression of VEGF, ANG-1, GATA-4, NKx2.5 MEF2c, PCNA, and eNOS was upregulated after preconditioning with HG/H-CCM, as evidenced by reverse transcriptase/polymerase chain reaction (RT-PCR). Concurrently, increased AKT phosphorylation, proliferation, angiogenic ability, and reduced levels of apoptosis were observed in HG/H-CCM-preconditioned diabetic MSCs compared with nontreated controls. HG/H-CCM-preconditioned diabetic-mouse-derived MSCs (dmMSCs) were transplanted in diabetic animals and demonstrated increased homing concomitant with augmented heart function. Gene expression of angiogenic and cardiac markers was significantly upregulated in conjunction with paracrine factors (IGF-1, HGF, SDF-1, FGF-2) and, in addition, reduced fibrosis, apoptosis, and increased angiogenesis was observed in diabetic hearts 4 weeks after transplantation of preconditioned dmMSCs compared with hearts with nontreated diabetic MSCs.ConclusionsPreconditioning with HG/H-CCM enhances survival, proliferation, and the angiogenic ability of dmMSCs, augmenting their ability to improve function in a diabetic heart.

The effect of gestational diabetes on proliferation capacity and viability of human umbilical cord-derived stromal cells

Stomal cells derived from Wharton’s jelly of human umbilical cord (WJMSCs) are considered as the potential therapeutic agents for regeneration and are getting famous for stem cell banking. Our study aims to evaluate the effects of gestational diabetes on proliferation capacity and viability of WJMSCs. Mesenchymal stromal cells were isolated from Wharton’s jelly of human umbilical cords from normal and gestational diabetic (DWJMSCs) mothers. Growth patterns of both types of cells were analyzed through MTT assay and population doubling time. Cell survival, cell death and glucose utilization were estimated through trypan blue exclusion assay, LDH assay and glucose detection assay respectively. Angiogenic ability was evaluated by immunocytochemistry and ELISA for VEGF A. Anti-cancerous potential was analyzed on HeLa cells. DWJMSCs exhibited low proliferative rate, increased population doubling time, reduced cell viability and increased cell death. Interestingly, DWJMSCs were found to have a reduced glucose utilization and anti-cancerous ability while enhanced angiogenic ability. Gestational diabetes induces adverse effects on growth, angiogenic and anti-cancerous potential of WJMSCs.

N-Acetyl cysteine protects diabetic mouse derived mesenchymal stem cells from hydrogen-peroxide-induced injury: A novel hypothesis for autologous stem cell transplantation.

Background Stem cell transplantation is one of the therapeutic options available to repair damaged organs. However, transplanted cells entail several challenges including their survival in diabetes‐affected injured tissue. This study was designed to determine the effects of preconditioning of mesenchymal stem cells (MSCs) with N‐acetyl cysteine (NAC), a widely used antioxidant drug. Methods Diabetic‐mouse‐derived MSCs (blood glucose ≥ 300 mg/dL) were preconditioned with 30mM NAC for 1 hour followed by oxidative injury with 100&mgr;M hydrogen peroxide (H2O2) for 1 hour. Results Gene expression analysis showed marked upregulation of prosurvival genes (Akt and Bcl‐2) and significantly downregulated expression of proapoptotic and stress genes (Capase‐3, Bax, Bak, p53, p38, and NF‐&kgr;B) in the 30mM‐NAC‐treated group when compared with those cells treated with H2O2 alone. NAC preconditioning improved cell viability, decreased lactate dehydrogenase release, &bgr;‐galactosidase activity, and Annexin‐V‐positive cells. Also, amelioration of oxidative stress, as shown by a decrease in malondialdehyde level and an increase in superoxide dismutase and catalase activities and glutathione level, was observed in the 30mM‐NAC‐treated group in comparison to cells treated with H2O2 alone. Conclusion This study demonstrates the potential benefits of pharmacological preconditioning of diabetic‐mouse‐derived MSCs with NAC for amelioration of apoptosis and oxidative stress in H2O2 induced injury.

Comparative analysis of biochemical parameters in diabetic and non-diabetic acute myocardial infarction patients

BACKGROUND Diabetes is a metabolic disorder characterized by enhanced production of free radicals hence oxidative stress. The aim of this study was to evaluate the activity of cardiac and antioxidant enzymes in diabetic and non-diabetic acute myocardial infarction (AMI) patients. METHODS This case-control study was conducted on 450 subjects (70-85 years). Subjects were divided into three groups (Normal, N; Non-diabetic AMI, N-AMI; and Diabetic AMI, D-AMI). Each individual was subjected to a detailed history, clinical examination, and cardiovascular parameters analysis (fasting blood sugar, HbA1c, systolic and diasystolic blood pressure, total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), TC/HDL and LDL/HDL ratios). Cardiac markers (Troponin-I, creatine phosphokinase (CPK), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), C-reactive protein (CRP) and aspartate aminotransferase (AST)) and oxidative stress markers (superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), catalase (CAT)) were also assessed. All these parameters were compared between diabetic and non-diabetic AMI patients. RESULTS D-AMI individuals had high level of TC, TG, LDL, and low level of HDL in comparison to N-AMI individuals. Study suggests that cardiac markers such as Troponin I, CPK, CK-MB, AST, LDH, and CRP levels were significantly increased in patients suffering from myocardial infarction with diabetes mellitus (DM) compared to patients of myocardial infarction without DM. The activity levels of antioxidant SOD and GSH were lower in D-AMI patients than in N-AMI. However, levels of MDA and CAT were higher in D-AMI than in N-AMI controls. CONCLUSION Study suggests elevated cardiac markers and reduced antioxidants in D-AMI patients compared to N-AMI patients.

Characterization of lipid parameters in diabetic and non-diabetic atherosclerotic patients

Background & Objective The relationship between lipid profile perturbation and diabetes associated complications has long been an area of interest. Dyslipidemia is a potent predictor of cardiovascular morbidity and mortality in diabetic patients. The aim of present study was to investigate relationship between aging and lipid profiles in diabetic and non-diabetic atherosclerotic patients. Methods Five hundred and seventy six individuals (45–75 year age) participated in this study. Among these, 192 were having history of diabetes mellitus and atherosclerosis. Individuals are categorized on the base of health (normal, non-diabetic atherosclerosis, diabetic atherosclerosis) and age (45–55 years, 56–65 years, and 66–75 years). All the participants were subjected to the procedures like a detailed history, biochemical analysis for fasting blood sugar, hemoglobin A1c, total cholesterol (TC), triglycerides (TG), low-density lipoprotein-(LDL), very low-density lipoprotein (VLDL) and high-density lipoprotein (HDL). All these parameters were compared between diabetic and non-diabetic atherosclerotic patients of all three age groups. TC/HDL and LDL/HDL were also calculated. Results Diabetic atherosclerotic individuals (both males and females) had high level of TC, TG, LDL, VLDL and low level of HDL in comparison to non-diabetic atherosclerotic and normal control individuals. Among all three age groups, lipoprotein abnormality was observed to be more frequent in females than males. There was a significant increase in TC/HDL and LDL/HDL ratio in diabetic atherosclerotic subjects compared to age and sex matched non-diabetic atherosclerotic and normal control. Conclusions Degree of dyslipidemia increases with increase in age in both genders. Female are more prone to diabetic dyslipidemia and hence have more risk of developing atherosclerosis with increasing age.

Effect of type 2 diabetic serum on the behavior of Wharton's jelly-derived mesenchymal stem cells in vitro

Objective Wharton jelly-derived mesenchymal stem cells (WJMSCs) exhibit multilineage differentiation potential and can be used to treat multiple organs. However, diabetes affects the repair capability of MSCs. The aim of this study was to evaluate the effect of diabetic patient-derived serum on WJMSC behavior. Methods WJMSCs at passage 3 were treated with serum derived from type 2 diabetic patients. WJMSCs were characterized for surface markers expression by using immunocytochemistry technique. The effects on cell viability, proliferation, cell death rate, and vascular endothelial growth factor level were assessed by crystal violet staining, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, lactate dehydrogenase assay, and enzyme-linked immuno-sorbent assay, respectively. Oxidative stress was assessed by the estimation of free radical species malondialdehyde (MDA) and enzymes glutathione (GSH), catalase, and superoxide dismutase (SOD). Results WJMSCs isolated in this study were positive for CD29, CD49, CD73, CD90, CD105, and SSEA4 and negative for CD45 and CD34. Under diabetic stress conditions, WJMSCs showed low viability and high lactate dehydrogenase release. A low level of vascular endothelial growth factor was also observed after diabetic serum treatment. Antioxidant level was also lower in diabetic serum-treated WJMSCs compared to in normal serum-treated WJMSCs. Conclusion The results of the present study suggest that pre-treatment of WJMSCs with type 2 diabetic serum decreases the survival of WJMSCs. The findings of this study provide insight into diabetes-induced harmful effects on WJMSCs.