Preconditioning of human umbilical cord mesenchymal stem cells with deferoxamine potentiates the capacity of the secretome released from the cells and promotes immunomodulation and beta cell regeneration in a rat model of type 1 diabetes.

This study aimed to examine the effects of the secretome released by human umbilical cord-mesenchymal stem cells (MSC) as a result of preconditioning with deferoxamine (DFX), a hypoxia mimetic agent, on type 1 diabetes (T1D), by comparing it with the secretome produced by untreated MSCs. Initially, the levels of total protein, IL4, IL10, IL17, and IFNγ in the conditioned medium (CM) obtained from MSCs subjected to preconditioning with 150 µM DFX (DFX-CM) were analyzed in comparison to CM derived from untreated MSCs (N-CM). Subsequently, the CMs were administered to rats with T1D within a specific treatment plan. Following the sacrification, immunomodulation was evaluated by measuring serum cytokine levels and assessing the regulatory T cell (Treg) ratio in spleen mononuclear cells. Additionally, ß-cell mass was determined in the islets by immunohistochemical labeling of NK6 Homeobox 1 (Nkx6.1), Pancreatic duodenal homeobox-1 (Pdx1), and insulin antibodies in pancreatic sections. In vitro findings indicated that the secretome levels of MSCs were enhanced by preconditioning with DFX. In vivo, the use of DFX-CM significantly increased the Treg population, and accordingly, the level of inflammatory cytokines decreased. In ß-cell marker labeling, D + DFX-CM showed significantly increased PDX1 and insulin immunoreactivity. In conclusion, while the factors released by MSCs without external stimulation had limited therapeutic effects, substantial improvements in immunomodulation and ß-cell regeneration were seen with DFX-preconditioned cell-derived CM.

Investigation of conditioned medium properties obtained from human umbilical cord mesenchymal stem/stromal cells preconditioned with dimethyloxalylglycine in a correlation with ultrastructural changes.

Mesenchymal stem/stromal cells (MSCs) hold significant therapeutic value due to their regeneration abilities, migration capacity, and immunosuppressive and immunomodulatory properties. These cells secrete soluble and insoluble factors, and this complex secretome contributes to their therapeutic effect. Furthermore, stimulation of cells by various external stimuli lead to secretome modifications that can increase the therapeutic efficacy. So, this study examined the effect of dimethyloxalylglycine (DMOG), a hypoxia-mimetic agent, on secretome profiles and exosome secretions of MSCs by evaluating conditioned medium (CM) and ultrastructural morphologies of the cells in comparison with unpreconditioned MSCs. The appropriate dose and duration of the use of DMOG were determined as 1000 µM and 24 h by evaluating the HIF-1α expression. DMOG-CM and N-CM were collected from MSCs incubated in serum-free medium with/without DMOG for 24 h, respectively. The content analysis of conditioned mediums (CMs) revealed that VEGF, NGF, and IL-4 levels were increased in DMOG-CM. Subsequently, exosomes were isolated from the CMs and were shown by transmission electron microscopy and Western blot analysis in both groups. The effects of CMs on proliferation and migration were determined by in vitro wound healing tests; both CMs increased the fibroblast's migratory and proliferative capacities. According to the ultrastructural evaluation, autophagosome, autolysosome, myelin figure, and microvesicular body structures were abundant in DMOG-preconditioned MSCs. Consistent with the high number of autophagic vacuoles, Beclin-1 expression was increased in those cells. These findings suggested that DMOG could alter MSCs' secretion profile, modify their ultrastructural morphology accordingly, and make the CM a more potent therapeutic tool. RESEARCH HIGHLIGHTS: Preconditioning mesenchymal stem/stromal cells with dimethyloxalylglycine, a hypoxia-mimetic agent, could modify cellular metabolism. Hypoxic mechanisms lead to alterations in the ultrastructural characteristics of mesenchymal stromal/stem cells. Preconditioning with dimethyloxalylglycine leads to ultrastructural and metabolic changes of mesenchymal stromal/stem cells along with modifications in their secretome profiles. Preconditioning of mesenchymal stromal/stem cells could render them a more potent therapeutic tool.

Physiological and gene expression responses of the mussel Mytilus galloprovincialis to low pH and low dissolved oxygen.

The prevalence and frequency of hypoxia events have increased worldwide over the past decade as a consequence of global climate change and coastal biological oxygen depletions. On the other hand, anthropogenic emissions of CO2 and consequent accumulation in the sea surface result in a perturbation of the seawater carbonate system, including a decrease in pH, known as ocean acidification. While the effect of decreases in pH and dissolved oxygen (DO) concentration is better understood, their combined effects are still poorly resolved. Here, we exposed adult mussels (Mytilus galloprovincialis) to two pHs (8.27 and 7.63) and DO concentrations (7.65 and 2.75 mg L-1) over 17 days in a full-factorial design. These levels correspond to extremes of the present natural variability and are relevant in the context of ocean acidification and hypoxia. No mortality was observed during the experiment. However, sublethal effects were observed for clearance and oxygen consumption rates, as well as total haemocytes count and haemocytes viability and gene expression in mussels exposed to the combination of low pH and low DO. Respiration and excretion rates were not significantly impacted by low pH and DO, alone or in combination. Overall, low pH alone led to a decrease in all tested physiological parameters while low DO alone led to a decline in clearance rate, haemocyte parameters and an increase in carbohydrate content. Both parameters led to up- or down-regulation of most of the selected genes. Not surprisingly, the combined effect of low pH and low DO could not be predicted by a simple arithmetic additive response at the effect level, highlighting more complex and non-linear effects.

UR-144, synthetic cannabinoid receptor agonist, induced cardiomyoblast toxicity mechanism comprises cytoplasmic Ca2+ and DAPK1 related autophagy and necrosis.

UR-144, a cannabinoid receptor agonist, is widely used alone or in combination with other synthetic cannabinoids (SCs) all over the world. At overdose, cardiovascular symptoms have been reported and the underlying molecular mechanisms of these adverse effects are not known. It is highly important to clarify the toxic effects of UR-144 for the treatment of poisoning. In the present study, the molecular mechanism of cytotoxic effects of UR-144 is evaluated on a cardiomyoblastic cell line using WST-1 and LDH assays. Apoptosis/necrosis, autophagy, and ROS (reactive oxygen species) levels were determined using flow cytometry. Cytoplasmic Ca2+ levels were measured by using a fluorogenic calcium-binding dye. Released and cytoplasmic troponin T levels, a specific marker of cardiotoxicity, were examined with western blot. For the evaluation of the role of DAPK1, on UR-144-induced cell death, DAPK1 activity and DAPK1 protein level were investigated. Its cytotoxic effects increased in a dose-dependent manner for WST-1 and LDH assays, while membrane damage, one of the signs of necrotic cell death, was more remarkable than damage to mitochondria. Cytoplasmic Ca2+ levels rose after high-dose UR-144 treatment and inhibition of DAPK1 activity ameliorated UR-144-induced cytotoxicity. Released troponin T significantly increased at a dose of 200 µM. ROS and total antioxidant capacity of cells were both reduced following high dose UR-144 treatment. The results indicated that UR-144-induced autophagic and necrotic cell death might be a consequence of elevated cytoplasmic Ca2+ levels and DAPK1 activation. However, in vivo/clinical studies are needed to identify molecular mechanisms of cardiotoxic effects of UR-144.

2D and 3D cultured human umbilical cord-derived mesenchymal stem cell-conditioned medium has a dual effect in type 1 diabetes model in rats: immunomodulation and beta-cell regeneration.

BACKGROUND: Type 1 diabetes (T1D) is a T-cell-mediated autoimmune disease characterized by the irreversible destruction of insulin-producing ß-cells in pancreatic islets. Helper and cytotoxic T-cells and cytokine production, which is impaired by this process, take a synergetic role in ß-cell destruction, and hyperglycemia develops due to insulin deficiency in the body. Mesenchymal stem cells (MSCs) appear like an excellent therapeutic tool for autoimmune diseases with pluripotent, regenerative, and immunosuppressive properties. Paracrine factors released from MSCs play a role in immunomodulation by increasing angiogenesis and proliferation and suppressing apoptosis. In this context, the study aims to investigate the therapeutic effects of MSC's secretomes by conditioned medium (CM) obtained from human umbilical cord-derived MSCs cultured in 2-dimensional (2D) and 3-dimensional (3D) environments in the T1D model. METHODS: First, MSCs were isolated from the human umbilical cord, and the cells were characterized. Then, two different CMs were prepared by culturing MSCs in 2D and 3D environments. The CM contents were analyzed in terms of total protein, IL-4, IL-10, IL-17, and IFN-λ. In vivo studies were performed in Sprague-Dawley-type rats with an autoimmune T1D model, and twelve doses of CM were administered intraperitoneally for 4 weeks within the framework of a particular treatment model. In order to evaluate immunomodulation, the Treg population was determined in lymphocytes isolated from the spleen after sacrification, and IL-4, IL-10, IL-17, and IFN-λ cytokines were analyzed in serum. Finally, ß-cell regeneration was evaluated immunohistochemically by labeling Pdx1, Nkx6.1, and insulin markers, which are critical for the formation of ß-cells. RESULTS: Total protein and IL-4 levels were higher in 3D-CM compared to 2D-CM. In vivo results showed that CMs induce the Treg population and regulate cytokine release. When the immunohistochemical results were evaluated together, it was determined that CM application significantly increased the rate of ß-cells in the islets. This increase was at the highest level in the 3D-CM applied group. CONCLUSION: The dual therapeutic effect of MSC-CM on immunomodulation and homeostasis/regeneration of ß-cells in the T1D model has been demonstrated. Furthermore, this effect could be improved by using 3D scaffolds for culturing MSCs while preparing CM.

Metformin induces mitochondrial remodeling and differentiation of pancreatic progenitor cells into beta-cells by a potential mechanism including suppression of the T1R3, PLCB2, cytoplasmic Ca+2, and AKT

The main goal of this study was to investigate the molecular changes in pancreatic progenitor cells subject to high glucose, aspartame, and metformin in vitro. This scope of work glucose, aspartame, and metformin were exposed to pancreatic islet derived progenitor cells (PID-PCs) for 10 days. GLUT1’s role in beta-cell differentiation was examined by using GLUT1 inhibitor WZB117. Insulin+ cell ratio was measured by flow cytometry; the expression of beta-cell differentiation related genes was shown by RT-PCR; mitochondrial mass, mitochondrial ROS level, cytoplasmic Ca2+, glucose uptake, and metabolite analysis were made fluorometrically and spectrophotometrically; and proteins involved in related molecular pathways were determined by western blotting. Findings showed that glucose or aspartame exposed cells had similar metabolic and gene expression profile to control PID-PCs. Furthermore, relatively few insulin+ cells in aspartame treated cells were determined. Aspartame signal is transmitted through PLCβ2, CAMKK2 and LKB1 in PID-PCs. The most obvious finding of this study is that metformin significantly increased beta-cell differentiation. The mechanism involves suppression of the sweet taste signal’s molecules T1R3, PLCβ2, cytoplasmic Ca+2, and AKT in addition to the direct effect of metformin on mitochondria and AMPK, and the energy metabolism of PID-PCs is remodelled in the direction of oxidative phosphorylation. These findings are very important in terms of determining that metformin stimulates the mitochondrial remodeling and the differentiation of PID-PCs to beta-cells and thus it may contribute to the compensation step, which is the first stage of diabetes development. (AU)

Therapeutic potential of conditioned medium obtained from deferoxamine preconditioned umbilical cord mesenchymal stem cells on diabetic nephropathy model.

BACKGROUND: The therapeutic potential of mesenchymal stem cells (MSCs)-derived conditioned media (CM) can be increased after preconditioning with various chemical agents. The aim of this study is comparative evaluation of effects of N-CM and DFS-CM which are collected from normal (N) and deferoxamine (DFS) preconditioned umbilical cord-derived MSCs on rat diabetic nephropathy (DN) model. METHODS: After incubation of the MSCs in serum-free medium with/without 150 µM DFS for 48 h, the contents of N-CM and DFS-CM were analyzed by enzyme-linked immunosorbent assay. Diabetes (D) was induced by single dose of 55 mg/kg streptozotocin. Therapeutic effects of CMs were evaluated by biochemical, physical, histopathological and immunohistochemical analysis. RESULTS: The concentrations of vascular endothelial growth factor alpha, nerve growth factor and glial-derived neurotrophic factor in DFS-CM increased, while one of brain-derived neurotrophic factor decreased in comparison with N-CM. The creatinine clearance rate increased significantly in both treatment groups, while the improvement in albumin/creatinine ratio and renal mass index values were only significant for D + DFS-CM group. Light and electron microscopic deteriorations and loss of podocytes-specific nephrin and Wilms tumor-1 (WT-1) expressions were significantly restored in both treatment groups. Tubular beclin-1 expression was significantly increased for DN group, but it decreased in both treatment groups. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cell death increased in the tubules of D group, while it was only significantly decreased for D + DFS-CM group. CONCLUSIONS: DFS-CM can be more effective in the treatment of DN by reducing podocyte damage and tubular apoptotic cell death and regulating autophagic activity with its more concentrated secretome content than N-CM.

Metformin induces mitochondrial remodeling and differentiation of pancreatic progenitor cells into beta-cells by a potential mechanism including suppression of the T1R3, PLCß2, cytoplasmic Ca+2, and AKT.

The main goal of this study was to investigate the molecular changes in pancreatic progenitor cells subject to high glucose, aspartame, and metformin in vitro. This scope of work glucose, aspartame, and metformin were exposed to pancreatic islet derived progenitor cells (PID-PCs) for 10 days. GLUT1's role in beta-cell differentiation was examined by using GLUT1 inhibitor WZB117. Insulin+ cell ratio was measured by flow cytometry; the expression of beta-cell differentiation related genes was shown by RT-PCR; mitochondrial mass, mitochondrial ROS level, cytoplasmic Ca2+, glucose uptake, and metabolite analysis were made fluorometrically and spectrophotometrically; and proteins involved in related molecular pathways were determined by western blotting. Findings showed that glucose or aspartame exposed cells had similar metabolic and gene expression profile to control PID-PCs. Furthermore, relatively few insulin+ cells in aspartame treated cells were determined. Aspartame signal is transmitted through PLCß2, CAMKK2 and LKB1 in PID-PCs. The most obvious finding of this study is that metformin significantly increased beta-cell differentiation. The mechanism involves suppression of the sweet taste signal's molecules T1R3, PLCß2, cytoplasmic Ca+2, and AKT in addition to the direct effect of metformin on mitochondria and AMPK, and the energy metabolism of PID-PCs is remodelled in the direction of oxidative phosphorylation. These findings are very important in terms of determining that metformin stimulates the mitochondrial remodeling and the differentiation of PID-PCs to beta-cells and thus it may contribute to the compensation step, which is the first stage of diabetes development.

Exendin-4 inhibits small intestinal glucose sensing and absorption through repression of T1R2/T1R3 sweet taste receptor signalling in streptozotocin diabetic mice.

The small intestine, which is the area where sugars are absorbed, should be considered in the approaches developed for the treatment of diabetes. However, studies on small intestine damage in diabetic individuals, and the effects of current treatments on the small intestine are very limited. This is the first study to investigate the effects of exendin-4, a GLP-1 receptor agonist, on small intestine injury in diabetic mice. BALB/c male mice were divided into 4 groups for this study. The first group was given citrate buffer, the second group was given exendin-4, the third group was given streptozotocin (STZ), and the fourth group was given both exendin-4, and STZ. As the results, we determined a decrease in the edema and deterioration in the integrity of the villi, disruption in continuity of the brush border, fibrosis and enterocyte apoptosis, while the TNFα level and crypt cell proliferation were increased in the small intestinal tissue of exendin-4 treated STZ diabetic mice. Furthermore, the levels of duodenal tissue glucose, SGLT1, and GLUT2 were decreased, whereas there was an increase in GIP level in diabetic mice administered with exendin-4. Moreover, we determined that the sweet taste receptors T1R2/T1R3, downstream molecules PLCß2, α-gustducin and associated secondary messengers IP3, cAMP, which were increased in the duodenal tissue of STZ-diabetic mice, decreased with exendin-4 administration. These findings were evaluated as that exendin-4 reduces glucose absorption by suppressing the T1R2/T1R3 sweet taste signal perception pathway in duodenum of STZ diabetic mice.

Vitamin U prevents valproic acid-induced liver injury through supporting enzymatic antioxidant system and increasing hepatocyte proliferation triggered by inflammation and apoptosis.

The aim of this study was to investigate the cellular mechanisms that cause valproic acid (VPA)-induced liver damage and the therapeutic effect of Vitamin U (Vit U) on these mechanisms. Female Sprague Dawley rats were randomly divided into four groups: intact control animals, animals that received Vit U (50 mg/kg/day), animals given VPA (500 mg/kg/day), and animals given both VPA and Vit U. The rats in the Vit U + VPA group were administered Vit U by gavage an hour before VPA administration every day for 15 days. Liver tissues were evaluated through histopathological, biochemical, immunohistochemical, and Western blotting techniques. Administration of Vit U with VPA resulted in (i) prevention of histopathological changes caused by VPA; (ii) blockage of the decrease in catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities; prevention of the elevation in gamma-glutamyl transferase (GGT) activity and advanced oxidation protein products (AOPP) level; (iii) increased in the levels of interleukin-1 beta (IL-1ß), active caspase-3, and cytoplasmic cytochrome c; (iv) increase in cleaved poly (ADP-ribose) polymerase (PARP) level and decrease in LC3B (II/I) ratio; (v) increase in the number of proliferating cells nuclear antigen (PCNA) positive hepatocytes. These findings show that Vit U prevents liver damage caused by VPA through increasing the antioxidant enzyme capacity and hepatocyte proliferation by triggering inflammation and apoptosis. These findings suggest that Vit U provides its protective effects against VPA-induced liver damage by stimulating homeostasis and regeneration.

Aspartame induces cancer stem cell enrichment through p21, NICD and GLI1 in human PANC-1 pancreas adenocarcinoma cells.

This study aimed to investigate the molecular effects of the common natural sugar glucose and artificial sweetener aspartame on cancer stem cell (CSC) population and cancer aggressiveness of PANC-1 human pancreas adenocarcinoma cells. According to our findings while aspartame exposure significantly increased the CSC population, high glucose had no effect on it. The epithelial-mesenchymal transition marker N-cadherin increased only in the aspartame group. The findings indicate that a high level of glucose exposure does not effect the invasion and migration of PANC-1 cells, while aspartame increases both of these aggressiveness criteria. The findings also suggest that a high concentration of glucose maintains CSC population through induction of nuclear Oct3/4 and differentiation to parental cells via increasing cytoplasmic c-myc. Aspartame exposure to PANC-1 cells activated AKT and deactivated GSK3ß by increasing levels of ROS and cytoplasmic Ca+2, respectively, through T1R2/T1R3 stimulation. Then p-GSK3ß(Ser9) boosted the CSC population by increasing pluripotency factors Oct3/4 and c-myc via NICD, GLI1 and p21. In the aspartame group, T1R1 silencing further increased the CSC population but decreased cell viability and suppressed the p21, NICD and GLI activation. The presence and amount of T1R subunits in the membrane fraction of PANC-1 cells are demonstrated for the first time in this study, as is the regulatory effect of T1R1's on CSC population. In conclusion, the present study demonstrated that long-term aspartame exposure increases CSC population and tumor cell aggressiveness through p21, NICD, GLI1. Moreover, while aspartame had no tumorigenic effect, it could potentially advance an existing tumor.

miR-375 induces adipogenesis through targeting Erk1 in pancreatic duct cells under the influence of sodium palmitate.

The goal of this study was to research long-term saturated fatty acid overexposure that can induce differentiation of pancreatic duct cells into adipocytes and also into ß-cells. The important findings can be summarized as follows: (i) adipogenesis and early stage ß-cell differentiation were stimulated in duct cells under lipotoxicity and glucolipotoxicity conditions, (ii) miR-375 expression was upregulated while its target Erk1 was downregulated and miR-375 inhibitor upregulated Erk1 while expression of adipogenesis markers was downregulated in duct cells under both conditions, (iii) apoptosis was induced in ß and duct cells under both conditions, (iv) lipotoxicity induced proliferation of co-cultured ß-cells. These findings suggest that long-term saturated fatty acid overexposure may cause intrapancreatic fat accumulation by inducing differentiation of duct cells into adipocytes and it may contributes to ß-cell compensation by stimulating the early stage of ß-cell differentiation in duct cells. In addition, miR-375 may have the potential to be a new target in the treatment of Type 2 diabetes, and NAFPD due to its role in the adipogenesis of duct cells.

Protective Effects of an Oxovanadium(IV) Complex with N2O2 Chelating Thiosemicarbazone on Small Intestine Injury of STZ-Diabetic Rats.

Vanadium compounds are being investigated as potential therapeutic agents in the treatment of many health problems, primarily diabetes. We aimed to provide the effect of N(1)-4-hydroxysalicylidene-N(4)-salicylidene-S-methyl-isothiosemicarbazidato-oxovanadium(IV) (VOL) on small intestinal injury in experimental male diabetic rats. Four groups were created of 3.0-3.5-month-old rats. The rats were made diabetic by a single dose of streptozotocin (STZ) at 65 mg/kg and grouped as follows: control animals, VOL-given control animals, STZ-induced diabetic animals and STZ-induced diabetic animals given VOL. A daily dose of 0.2 mM/kg vanadium complex was administered orally for 12 days after the inducement of diabetes. On the 12th day, small intestine tissue samples were taken. According to the data obtained from the biochemical analysis, reduced glutathione (GSH) level, catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD), Na+/K+-ATPase and paraoxanase (PON) activities were increased, whereas sialic acid (SA), xanthine oxidase (XO) and disaccharidases (maltase and saccharidase) activities were decreased in the small intestine tissue of VOL-treated diabetic rats. Microscopic examinations revealed a remarkable decrease in the mucosal necrotic areas, discontinuity in the brush border, deterioration of the villi integrity and oedema inside the villi, but with a mild decrease in the inflammatory cells, deterioration and loss of integrity of the gland in the small intestine of VOL-treated diabetic rats. Moreover, VOL treatment markedly decreased the proliferation of villus cells and especially inflammatory cells in the small intestine of diabetic rats. According to the obtained data, the administration of VOL is a potentially convenient strategy to reducing small intestine injury in diabetic rats.

Tub and ß-catenin play a key role in insulin and leptin resistance-induced pancreatic beta-cell differentiation.

The aim of this study was to investigate the molecular mechanism of pancreatic islet-derived mesenchymal stem cell (PID-MSC) differentiation into beta-cells in the presence of insulin and leptin resistance stimulators. We determined that beta-cell differentiation was stimulated by glucose, insulin, and leptin. Co-administration of insulin and leptin resulted in greater, at a further stage of differentiation but non-functional beta-cell formation. The levels of p-AKT(Ser473) did not change; SOCS3, PTP1B, p-IRS1(Ser307), PTEN levels increased and p-IRS1(Try) levels decreased due to insulin and leptin co-administration. These findings suggest that co-administration of insulin and leptin to PID-MSCs results in the development of both insulin and leptin resistance together. We showed that this differentiation signaling is mainly mediated by AKT/GSK-3ß/ß-catenin and Tub. Moreover, ß-catenin and Tub were linked to each other in the nucleus under this condition. Furthermore, we found that Tub and ß-catenin contributes to insulin production by increasing the expression of transcription factors by binding to the promoter regions of ins1, ins2, and pdx1 genes. In addition, Tub is also bound to the promoter region of the MafA gene. These findings demonstrate that when insulin and leptin resistance develop together in rat PID-MSCs beta-cell differentiation increases markedly via ß-catenin and Tub. New therapeutic agents that inhibit AKT/GSK-3ß/ß-catenin and in particular Tub may help prevent the development or retard the progression of type 2 diabetes.

4-Methylcatechol prevents streptozotocin-induced acute kidney injury through modulating NGF/TrkA and ROS-related Akt/GSK3ß/ß-catenin pathways.

Nerve growth factor (NGF) has been shown to protect the viability of kidney cells in acute phase of renal damage. However, since the half-life of NGF is very short, it is too large to pass the blood-brain barrier and rapidly transported to the liver for catabolizing its use in therapy is limited. 4-Methylcatechol (4MC) is a substance that increases NGF synthesis in many tissues. This study aimed to investigate the protective effects of 4MC against acute renal injury induced by streptozotocin (STZ). We have investigated the profibrotic, proinflammatory, oxidative changes in STZ-induced acute renal damage and the possible role of the NGF/TrkA system and Akt/GSK3ß/ß-catenin pathway in this mechanism. Experiment was designed as to be started with injection of 4MC for 10 days as a single dose (10 µg/kg) per day and to be terminated after 4 h of a single dose (75 mg/kg) STZ injection. As the result, 4MC pre-treatment decreased kidney damage, ROS production, the renal levels of TGFß1, CD68, tumor necrosis factor-α and interleukin 1ß. Moreover, 4MC pre-treatment increased levels of NGF and its receptor TrkA, p-Akt (Thr308), p-GSK3ß (Ser9) and nuclear ß-catenin. These data suggest that 4MC prevents the development of STZ-induced renal damage by suppressing ROS production and inflammation via Akt/GSK3ß/ß-catenin pathway which may be stimulated by NGF/TrkA signaling. Therefore, 4MC can be suggested as a potential agent for the prevention of acute renal injury.

Involvement of dying beta cell originated messenger molecules in differentiation of pancreatic mesenchymal stem cells under glucotoxic and glucolipotoxic conditions.

Beta cell mass regulation represents a critical issue for understanding and treatment of diabetes. The most important process in the development of diabetes is beta cell death, generally induced by glucotoxicity or glucolipotoxicity, and the regeneration mechanism of new beta cells that will replace dead beta cells is still not fully understood. The aim of this study was to investigate the generation mechanism of new beta cells by considering the compensation phase of type 2 diabetes mellitus. In this study, pancreatic islet derived mesenchymal stem cells (PI-MSCs) were isolated from adult rats and characterized. Then, beta cells isolated from rats were co-cultured with PI-MSCs and they were exposed to glucotoxicity, lipotoxicity and glucolipotoxicity conditions for 72 hr. As the results apoptotic and necrotic cell death were increased in both PI-MSCs and beta cells especially by the exposure of glucotoxic and glucolipotoxic conditions to the co-culture systems. Glucotoxicity induced-differentiated beta cells were functional due to their capability of insulin secretion in response to rising glucose concentrations. Moreover, beta cell proliferation was induced in the glucotoxicity-treated co-culture system whereas suppressed in lipotoxicity or glucolipotoxicity-treated co-culture systems. In addition, 11 novel proteins, that may release from dead beta cells and have the ability to stimulate PI-MSCs in the direction of differentiation, were determined in media of glucotoxicity or glucolipotoxicity-treated co-culture systems. In conclusion, these molecules were considered as important for understanding cellular mechanism of beta cell differentiation and diabetes. Thus, they may be potential targets for diagnosis and cellular or therapeutic treatment of diabetes.

Exendin-4 partly ameliorates - hyperglycemia-mediated tissue damage in lungs of streptozotocin-induced diabetic mice.

Glucagon-like peptide-1 (GLP-1) stimulates insulin secretion, - plays anti-inflammatory role in atherosclerosis, and has surfactant-releasing effects in lungs. GLP-1 analogues are used in diabetes therapy. This is the first study to investigate the effects of exendin-4, a GLP-1 receptor agonist, on lung injury in diabetic mice. BALB/c male mice were divided into four groups. The first group was given only citrate buffer, the second group was given only exendin-4, the third group was given only streptozotocin (STZ), and the fourth group was given both exendin-4 and STZ. Exendin-4 (3µg/kg) was administered daily by subcutaneous injection for 30days after mice were rendered diabetic with a single dose of STZ (200mg/kg). Structural alterations, oxidative stress, apoptosis, insulin signaling and expressions of prosurfactant-C, alpha-smooth muscle actin, collagen-I and fibronectin were evaluated in lung tissue. Diabetic mice lungs were characterized by induced oxidative stress, apoptosis, edema, and cell proliferation. They had honeycomb-like alveoli, thicker alveolar walls, and hypertrophic pneumocytes. Although exendin-4 treatment improved pulmonary edema, apoptosis, oxidative stress, and lung injury, it led to the disrupted insulin signaling and interstitial collagen accumulation in the lungs of diabetic mice. Exendin-4 ameliorates hyperglycemia-mediated lung damage by reducing glucose, -oxidative stress and stimulating cell proliferation. However, exendin-4 led to increased lung injury partly by reducing insulin signaling - and collagen accumulation around pulmonary vasculature in diabetic mice.

The Role of Epigenetic Regulation and Pluripotency-Related MicroRNAs in Differentiation of Pancreatic Stem Cells to Beta Cells.

In this study, we aimed to research the effects of class-I HDACs and glucose on differentiation of pancreatic islet derived mesenchymal stem cells (PI-MSCs) to beta cells. Beta cell differentiation determined by flow cytometric analysis and gene expression levels of PDX1, PAX4, PAX6, NKX6.1, NGN3, INS2, and GLUT2. As a result the valproic acid, is an inhibitor of class-I HDACs, caused the highest beta cell differentiation in PI-MSCs. However, the cells in this group were at early stages of differentiation. Glucose co-administration to this group carried the differentiation to higher levels, but these newly formed beta cells were not functional. Moreover, reduction in the levels of pluripotency factors that Oct3/4, c-Myc, and Nanog were parallel to beta cell differentiation. Also, the levels of HDAC1 and acetylated H3/H4 were increased and methylated H3 was decreased by VPA treatment. In addition, we have detected over expression in genes of miR-18a-5p, miR-19b-5p, miR-30d-3p, miR-124, miR-146a-5p, miR-184, miR-335, and miR-433-5p in parallel to beta cell differentiation. As the conclusion, this study is important for understanding the epigenetic mechanism that controls the beta cell differentation and it suggests new molecules that can be used for diagnosis, and treatment of diabetes. J. Cell. Biochem. 119: 455-467, 2018. © 2017 Wiley Periodicals, Inc.

Prostaglandin-E1 has a protective effect on renal ischemia/reperfusion-induced oxidative stress and inflammation mediated gastric damage in rats.

Gastrointestinal complications are frequent in renal transplant recipients. In this regard, renal ischemia/reperfusion injury (IRI)-induced gastric damage seems to be important and there is no data available on the mechanism of this pathology. Because of its anti-inflammatory and anti-oxidant properties, it can be suggested that prostaglandin-E1 (PGE1) protects cells from renal IRI-induced gastric damage. The aim of this study was to investigate the molecular mechanisms of gastric damage induced by renal IRI and the effect of PGE1 on these mechanisms. We set an experiment with four different animal groups: physiological saline-injected and sham-operated rats, PGE1 (20µg/kg)-administered and sham operated rats, renal IRI subjected rats, and PGE1-administered and renal IRI subjected rats. The protective effect of PGE1 on renal IRI-induced gastric damage was determined based on reduced histological damage and lactate dehydrogenase activity. Moreover, we demonstrated that PGE1 shows its protective effect through reducing the production of reactive oxygen species and malondialdehyde levels. During histological examination, we observed the presence of common mononuclear cell infiltration. Therefore, pro-inflammatory cytokines tumor necrosis factor-α and interleukin-1ß levels were measured and it has been shown that PGE1 suppressed both cytokines. Furthermore, it was found that PGE1 reduced the number of NF-κB(+) and caspase-3(+) inflammatory cells, and also NF-κB DNA-binding activity, while increasing proliferating cell nuclear antigen(+) epithelial cells in the stomach tissue of rats subjected to renal IR. Our data showed that PGE1 has a protective effect on renal IRI-induced oxidative stress and inflammation mediated gastric damage in rats.