Lentinan confers protection against type 1 diabetes by inducing regulatory T cell in spontaneous non-obese diabetic mice.

BACKGROUND: Lentinan (LNT) is a complex fungal component that possesses effective antitumor and immunostimulating properties. However, there is a paucity of studies regarding the effects and mechanisms of LNT on type 1 diabetes. OBJECTIVE: In the current study, we investigated whether an intraperitoneal injection of LNT can diminish the risk of developing type 1 diabetes (T1D) in non-obese diabetic (NOD) mice and further examined possible mechanisms of LNT's effects. METHODS: Pre-diabetic female NOD mice 8 weeks of age, NOD mice with 140-160 mg/dL, 200-230 mg/dL or 350-450 mg/dL blood glucose levels were randomly divided into two groups and intraperitoneally injected with 5 mg/kg LNT or PBS every other day. Then, blood sugar levels, pancreas slices, spleen, PnLN and pancreas cells from treatment mice were examined. RESULTS: Our results demonstrated that low-dosage injections (5 mg/kg) of LNT significantly suppressed immunopathology in mice with autoimmune diabetes but increased the Foxp3+ regulatory T cells (Treg cells) proportion in mice. LNT treatment induced the production of Tregs in the spleen and PnLN cells of NOD mice in vitro. Furthermore, the adoptive transfer of Treg cells extracted from LNT-treated NOD mice confirmed that LNT induced Treg function in vivo and revealed an enhanced suppressive capacity as compared to the Tregs isolated from the control group. CONCLUSION: LNT was capable of stimulating the production of Treg cells from naive CD4 + T cells, which implies that LNT exhibits therapeutic values as a tolerogenic adjuvant and may be used to reverse hyperglycaemia in the early and late stages of T1D.

Molecular Iodine Supplement Prevents Streptozotocin-Induced Pancreatic Alterations in Mice.

Pancreatitis has been implicated in the development and progression of type 2 diabetes and cancer. The pancreas uptakes molecular iodine (I2), which has anti-inflammatory and antioxidant effects. The present work analyzes whether oral I2 supplementation prevents the pancreatic alterations promoted by low doses of streptozotocin (STZ). CD1 mice (12 weeks old) were divided into the following groups: control; STZ (20 mg/kg/day, i.p. for five days); I2 (0.2 mg/Kg/day in drinking water for 15 days); and combined (STZ + I2). Inflammation (Masson's trichrome and periodic acid-Schiff stain), hyperglycemia, decreased ß-cells and increased α-cells in pancreas were observed in male and female animals with STZ. These animals also showed pancreatic increases in immune cells and inflammation markers as tumor necrosis factor-alpha, transforming growth factor-beta and inducible nitric oxide synthase with a higher amount of activated pancreatic stellate cells (PSCs). The I2 supplement prevented the harmful effect of STZ, maintaining normal pancreatic morphometry and functions. The elevation of the nuclear factor erythroid-2 (Nrf2) and peroxisome proliferator-activated receptor type gamma (PPARγ) contents was associated with the preservation of normal glycemia and lipoperoxidation. In conclusion, a moderated supplement of I2 prevents the deleterious effects of STZ in the pancreas, possibly through antioxidant and antifibrotic mechanisms including Nrf2 and PPARγ activation.

Sargassum fusiforme polysaccharide is a potential auxiliary substance for metformin in the management of diabetes.

The present study investigated the positive effects of relatively low-dose metformin combined with Sargassum fusiforme polysaccharide (LMET-SFP) in high-fat diet and streptozotocin-induced diabetic rats, and explored the underlying mechanisms of LMET-SFP as compared to metformin alone in managing diabetes. The results indicate that both metformin and LMET-SFP can attenuate body weight loss and ameliorate hyperglycemia, insulin resistance and hyperlipidemia, and LMET-SFP exhibited better effects in lowering fasting blood glucose levels, insulin resistance index and serum cholesterol compared to metformin only. The administration of LMET-SFP could ameliorate liver dysfunction in diabetic rats. In addition, fecal bile acid data implied that LMET-SFP intervention contributed to an increase in fecal total bile acids, ursodesoxycholic acid and tauroursodesoxycholic acid profiles when compared to metformin treatment. Additionally, intestinal microbiological analysis showed that the acknowledged probiotics Lactobacillus and Bifidobacterium exhibited higher levels in the LMET-SFP group compared to the metformin group. RT-qPCR results demonstrated that the better hypoglycemic effects of LMET-SFP were mainly attributed to the down-regulation of 3-hydroxy-3-methylglutaryl-coenzyme A, cytosolic phosphoenolpyruvate carboxykinase and glucose-6-phosphatase expression, and the up-regulation of cholesterol 7α-hydroxylase expression, in contrast to metformin alone. These results suggest that SFP may be used as an auxiliary hypoglycemic substance for metformin in the future.

Hypoglycemic effect of a novel polysaccharide from Lentinus edodes on STZ-induced diabetic mice via metabolomics study and Nrf2/HO-1 pathway.

Objective: With the rising prevalence of diabetes worldwide, increased attention is focused on natural drug candidates that can treat diabetes with high efficacy but without undesired side effects. Lentinus edodes is an edible and medicinal fungus, whose polysaccharides are one of the main components that have been reported to have hypoglycemic ability. However, the detailed underlying hypoglycemic mechanism of Lentinus edodes polysaccharides is still unknown. In this study, we extracted and prepared a novel polysaccharide from Lentinus edodes, which was named LNT-1. Methods: The aim of this study was to evaluate the hypoglycemic effect of LNT-1 on mice with type 2 diabetes that was induced by a high fat and high sugar diet and streptozotocin. To explore the possible mechanism, metabolomics analysis based on UPLC-Q-TOF/MS and molecular methods were performed. Results: Data showed that treatment with LNT-1 could ameliorate the damage in diabetic mice, including physiological and biochemical indexes, oxidative parameters and histopathological changes. Moreover, 36 potential biomarkers were screened using metabolomics analysis based on UPLC-Q-TOF/MS. Among them, the main metabolic pathways were glycerophospholipid metabolism, arachidonic acid metabolism and arginine biosynthesis, thereby suggesting that oxidative stress may be involved in the occurrence of diabetes. Both the mRNA and protein expression of the Nrf2/HO-1 signaling pathway was upregulated after treatment with LNT-1, indicating that the hypoglycemic effect of LNT-1 may be related to the activation of the Nrf2/HO-1 pathway. Conclusion: LNT-1 may be a potential natural drug candidate for the prevention and treatment of diabetes by regulating the oxidative stress response. Our study aimed to provide new insights into the application of Lentinus edodes and its polysaccharide as a drug candidate and as an active ingredient in functional foods.

The impact of a novel Chinese yam-derived polysaccharide on blood glucose control in HFD and STZ-induced diabetic C57BL/6 mice.

Chinese yam, as a kind of traditional "medicine and food homologous food" in Asia, could assistance to digestion, nourish the lungs and relieve cough. Some research also suggested that Chinese yam could prevention of hyperglycemia, but the specific mechanism of action was not clear. In this paper, an acidic polysaccharide (CYPB) was isolated from Chinese yam with the molecular weight of 1.55 × 102 kDa. The determination of the monosaccharide composition of CYPB with ion chromatography showed that CYPB was composed of rhamnose, glucose, arabinose, galactose, glucose, xylose and glucuronic acid with the ratio of 6 : 3.73 : 7.31 : 10.95 : 4.56 : 1. The structural analysis indicated that the CYPB contain 1 → 3, 1 → 4, 1 → 2, 1 → 6 and 1 → 3, 6 glycoside bonds. The experimental results of diabetic mice model induced by high-fat diet (HFD) and streptozocin (STZ) indicated that CYPB could improve clinical symptoms and alleviate the glucose tolerance damage symptoms effectively. The underlying mechanism of regulate blood glucose of CYPB may be related to improve the ability of synthesize glycogen, insulin resistance and reduce gluconeogenesis by regulating the expression of InsR, PI3K, Akt and FoxO3, GLUT4 proteins in PI3K/Akt signaling pathway in T2DM mice.

Fucoidan protects the pancreas and improves glucose metabolism through inhibiting inflammation and endoplasmic reticulum stress in T2DM rats.

It is important to maintain the normal function of the pancreas in the prevention and intervention of type 2 diabetes mellitus (T2DM). This study was undertaken to explore the protective effects of fucoidan on the pancreas in T2DM rats induced by using a high fat diet (HFD) and low dose of streptozotocin (STZ) injection. The results showed fucoidan remarkably decreased the levels of fasting blood glucose, serum insulin and glycated serum protein, and increased the level of glucagon-like peptide-1 in T2DM rats. Also, fucoidan improved insulin sensitivity and reduced the postprandial blood glucose level. Meanwhile, fucoidan alleviated pancreas damage and improved the islet ß cell function in T2DM rats. Additionally, fucoidan activated the PI3K/AKT signaling pathway and regulated glucose homeostasis, which seemed to be related to the protection of the pancreas from damage by inhibiting inflammation and endoplasmic reticulum stress in T2DM rats. Collectively, these results indicated that fucoidan had a potential protective effect on the pancreas, which enriched ideas for the use of fucoidan as a nutritional agent in the cure of T2DM.

Hypoglycemic activity of Codonopsis pilosula (Franch.) Nannf. in vitro and in vivo and its chemical composition identification by UPLC-Triple-TOF-MS/MS.

Codonopsis pilosula (Franch.) Nannf. (CPN), mainly planted in the northwest region, is a traditional Chinese medicine/good health food for nourishing qi and promoting blood circulation. This study firstly evaluated the inhibitory effects of the CPN extraction (CPNE) on α-glucosidase in vitro and in vivo, and tentatively confirmed its chemical ingredients by employing UHPLC-Triple-TOF-MS/MS. The CPNE had strong inhibitory activities against mammalian α-glucosidase (sucrase and maltase) and yeast α-glycosidase with semi-inhibitory concentrations (IC50) of 0.241 mg mL-1, 0.326 mg mL-1 and 1.167 mg mL-1, respectively. In addition, the CPNE could significantly decrease the postprandial blood glucose (PBG) levels in the sucrose/maltose/starch tolerance assays of diabetic mice. Furthermore, a total of 29 compounds, including 3 alkaloids, 13 phenolic acids, 8 alcohol glycosides and 5 alkynosides, were assigned based on comparison with the standards and references, as well as the analysis of main fragments. These results demonstrated that CPN could be used as an adjuvant therapy or dietary supplements to effectively control the occurrence and development of diabetes.

Alpha-Lipoic Acid Inhibits Spontaneous Diabetes and Autoimmune Recurrence in Non-Obese Diabetic Mice by Enhancing Differentiation of Regulatory T Cells and Showed Potential for Use in Cell Therapies for the Treatment of Type 1 Diabetes.

Type 1 diabetes (T1D) is caused by the destruction of ß cells in pancreatic islets by autoimmune T cells. Islet transplantation has been established as an effective treatment for T1D. However, the survival of islet grafts is often disrupted by recurrent autoimmunity. Alpha-lipoic acid (ALA) has been reported to have immunomodulatory effects and, therefore, may have therapeutic potential in the treatment of T1D. In this study, we investigated the therapeutic potential of ALA in autoimmunity inhibition. We treated non-obese diabetic (NOD) mice with spontaneous diabetes and islet-transplantation mice with ALA. The onset of diabetes was decreased and survival of the islet grafts was extended. The populations of Th1 cells decreased, and regulatory T cells (Tregs) increased in ALA-treated mice. The in vitro Treg differentiation was significantly increased by treatment with ALA. The adoptive transfer of ALA-differentiated Tregs into NOD recipients improved the outcome of the islet grafts. Our results showed that in vivo ALA treatment suppressed spontaneous diabetes and autoimmune recurrence in NOD mice by inhibiting the Th1 immune response and inducing the differentiation of Tregs. Our study also demonstrated the therapeutic potential of ALA in Treg-based cell therapies and islet transplantation used in the treatment of T1D.

Hypophosphorylated pRb knock-in mice exhibit hallmarks of aging and vitamin C-preventable diabetes.

Despite extensive analysis of pRB phosphorylation in vitro, how this modification influences development and homeostasis in vivo is unclear. Here, we show that homozygous Rb∆K4 and Rb∆K7 knock-in mice, in which either four or all seven phosphorylation sites in the C-terminal region of pRb, respectively, have been abolished by Ser/Thr-to-Ala substitutions, undergo normal embryogenesis and early development, notwithstanding suppressed phosphorylation of additional upstream sites. Whereas Rb∆K4 mice exhibit telomere attrition but no other abnormalities, Rb∆K7 mice are smaller and display additional hallmarks of premature aging including infertility, kyphosis, and diabetes, indicating an accumulative effect of blocking pRb phosphorylation. Diabetes in Rb∆K7 mice is insulin-sensitive and associated with failure of quiescent pancreatic ß-cells to re-enter the cell cycle in response to mitogens, resulting in induction of DNA damage response (DDR), senescence-associated secretory phenotype (SASP), and reduced pancreatic islet mass and circulating insulin level. Pre-treatment with the epigenetic regulator vitamin C reduces DDR, increases cell cycle re-entry, improves islet morphology, and attenuates diabetes. These results have direct implications for cell cycle regulation, CDK-inhibitor therapeutics, diabetes, and longevity.

Diaphragma juglandis extracts modifies the gut microbiota during prevention of type 2 diabetes in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The diaphragma juglandis (DJ) comes from the wooden septum in the core of Juglans regia L, also known as the walnut septum. In Iranian traditional medicine, walnut distraction wood was widely used in the treatment of diabetes. However, there is a lack of research data on the mechanism of DJ against diabetes. AIM OF THE STUDY: To explore the protective effect of diaphragma juglandis extract (DJE) on type 2 diabetic rats and the hypoglycemic mechanism of DJE. MATERIAL AND METHODS: Supplemented DJE and fed a high-fat diet for five weeks, and then injected low-dose STZ, successfully induced type 2 diabetic rats. Collected rat serum, liver, pancreas and feces to determine the biochemical parameters of serum and liver, analyze the pathological damages of pancreas and liver, and measure the changes of gut microbes in feces. RESULTS: DJE could inhibit the metabolic abnormalities of T2DM by improving insulin resistance, abnormal lipid metabolism, liver damage, oxidative stress, and reducing inflammation. DJE significantly held fasting blood glucose, glycosylated serum protein, serum low density lipoprotein, high density lipoprotein, oral glucose tolerance test, nitric oxide, superoxide dismutase and catalase, serum and liver triglycerides, total cholesterol, aspartate aminotransferase, alanine aminotransferase, malondialdehyde, lipopolysaccharide, fasting insulin and tumor necrosis factor-α and prevented the pathological damage of pancreas and liver. The 16SrRNA gene sequencing results showed that DJE intercepted the disorders of the fecal gut microbes, mainly including Lactobacillaceae, Rikenella, Pygmaiobacter, Oscillospiraceae and Klebsiella. Spearman correlation analysis showed that the changes of gut microbes were closely relative with biochemical parameters. CONCLUSION: DJE might prevent type 2 diabetes and its complications and hold up the disorders of gut microbes.

Cardioprotective Effects and in-silico Antioxidant Mechanism of L-Ergothioneine in Experimental Type-2 Diabetic Rats.

BACKGROUND: Diabetic cardiotoxicity is commonly associated with oxidative injury, inflammation, and endothelial dysfunction. L-ergothioneine (L-egt), a diet-derived amino acid, has been reported to decrease mortality and risk of cardiovascular injury, provides cytoprotection to tissues exposed to oxidative damage, and prevents diabetes-induced perturbation. OBJECTIVE: This study investigated the cardioprotective effects of L-egt on diabetes-induced cardiovascular injuries and its probable mechanism of action. METHODS: Twenty-four male Sprague-Dawley rats were divided into non-diabetic (n = 6) and diabetic groups (n = 18). Six weeks after the induction of diabetes, the diabetic rats were divided into three groups (n = 6) and administered distilled water, L-egt (35mg/kg), and losartan (20mg/kg) by oral gavage for six weeks. Blood glucose and mean arterial pressure (MAP) were recorded pre-and post-treatment, while biochemical, ELISA, and RT-qPCR analyses were conducted to determine inflammatory, injury-related and antioxidant biomarkers in cardiac tissue after euthanasia. Also, an in-silico study, including docking and molecular dynamic simulations of L-egt toward the Keap1- Nrf2 protein complex, was done to provide a basis for the molecular antioxidant mechanism of Legt. RESULTS: Administration of L-egt to diabetic animals reduced serum triglyceride, water intake, MAP, biomarkers of cardiac injury (CK-MB, CRP), lipid peroxidation, and inflammation. Also, Legt increased body weight, antioxidant enzymes, upregulated Nrf2, HO-1, NQO1 expression, and decreased Keap1 expression. The in-silico study showed that L-egt inhibits the Keap1-Nrf2 complex by binding to the active site of Nrf2 protein, thereby preventing its degradation. CONCLUSION: L-egt protects against diabetes-induced cardiovascular injury via the upregulation of the Keap1-Nrf2 pathway and its downstream cytoprotective antioxidants.

Inhibition of PAD4-mediated NET formation by cl-amidine prevents diabetes development in nonobese diabetic mice.

Many evidences indicated that neutrophil extracellular traps (NETs) play pathogenic roles in type 1 diabetes (T1D). Peptidylarginine deiminases 4 (PAD4) has been proved to be indispensable for generation of NETs. In the current study, we investigated whether oral administration of cl-amidine, an effective inhibitor of PAD4, protects non-obese diabetic (NOD) mice from T1D development. Female NOD mice were orally administrated with cl-amidine (5 µg/g body weight) from the age of 8 weeks up to 16 weeks. It showed that cl-amidine inhibit NET formation in vitro and in vivo. The onset of T1D was delayed nearly 8 weeks and the incidence of disease was significantly decreased in cl-amidine treated mice compared with the control group. Moreover, cl-amidine decreased the serum levels of anti-citrullinated peptide antibody (ACPA) and anti-neutrophil cytoplasmic antibodies (ANCA) in NOD mice. Also, it decreased generation of T1D autoantibodies such as glutamic acid decarboxylase antibody (GADA), tyrosine phosphatase-related islet antigen-2 antibody (IA2A) and zinc transporter 8 antibody (ZnT8A), which were strongly correlated with the reduced serum PAD4 and MPO-DNA levels. Furthermore, cl-amidine administration inhibited pancreatic inflammation and increased frequency of regulatory T cells in pancreatic lymph nodes (PLNs). In addition, cl-amidine improved gut barrier dysfunction and decreased the serum level of lipopolysaccharide (LPS), which was positively correlated with the NETs markers (PAD4 and MPO-DNA) and T1D autoantibody IA2A. In conclusion, our data showed that orally delivery of cl-amidine effectively prevent T1D development and suggested inhibition of PAD4-dependent NET formation as a potential way of clinical treatment in T1D.

High Throughput Study for Molecular Mechanism of Metformin Pre-Diabetic Protection via Microarray Approach.

BACKGROUND: Metformin is a biguanide that exhibits antidiabetic, anticarcinogenic, and anti-inflammatory properties. Despite well-known pancreatic protective effects, metformin's influence on pancreatic islet ß-cell is yet considerably unknown. Protecting the functional insulin-producing ß-cells in the pancreas is a key therapeutic challenge in patients with type 1 (T1DM) or type 2 diabetes mellitus (T2DM). OBJECTIVE: The current study aimed to analyze the protective effects of metformin on streptozocin- induced diabetic rats in T1DM in hepatic tissues. METHODS: In the present study, male Wistar rats (n=24) were randomly assigned into 2 groups (n=12 for each control and test), and metformin (100 mg/kg/day) was given for 7 weeks. Afterward, diabetes was induced by streptozocin (STZ) at a single dose of 150 mg/kg. Blood glucose was examined daily before and after STZ induction. The animals were euthanized by cervical dislocation 5 days after streptozocin injection, after which liver and pancreas were harvested from each rat. RESULTS: The biochemical analyses revealed that metformin resulted in significantly reduced plasma glucose levels and higher pancreatic insulin levels in the test group. Using a restrictive cut-off of at least 2-FC and an adjusted p-value (q-value) of ≤0.05, a sum of 747 genes for the metformin group were shown to be differentially regulated compared to controls (320 Down and 427 Up), by which they were obtained from the liver. Furthermore, the evidence is attained that metformin may hinder the loss of critical ß-cells by reducing inflammatory and apoptosis signaling, promoting fatty acid ß-oxidation, and inducing metabolism. CONCLUSION: Collectively, this study has demonstrated a decrease in blood glucose levels and a rise in insulin-levels and thus consequent prophylactic effects in metformin-given STZ-induced diabetic rats.

Anti-diabetogenic and in vivo antioxidant activity of ethanol extract of Dryopteris dilatata in alloxan-induced male Wistar rats.

AIMS: Oxido-inflammatory stress has been implicated as the main targets in alleviating diabetic complications induced by hyperglycaemia. Dryopteris dilatata: a bioactive plant serves great medicinal benefits in ethnopharmacology to ameliorate pathological conditions. This study investigated the protective effects of ethanol extract of Dryopteris dilatata (EEDD) in alloxan-induced diabetic rats through mechanism involving inhibition of oxidative stress and liver and kidney inflammatory markers. METHODOLOGY: Male Wistar rats were made diabetic via alloxan monohydrate (100 mg/kg) administration intraperitoneally. Diabetic rats were post-treated with EEDD (800 mg/kg) and Metformin (50 mg/kg) orally for two weeks. Fasting blood sugar (FBS), body and organ weight change, markers of oxidative stress, liver and kidney inflammation were evaluated. RESULTS: Our results revealed that EEDD significantly reduced alloxan-induced hyperglycaemia in the diabetic rats after 5, 10 and 15 days of treatment. Markers of oxidative injury were also significantly ameliorated in the pancreas, liver and kidney of the diabetic rats following treatment with EEDD. However, liver and kidney injury markers were significantly attenuated with marked decreased organ weight in the diabetic rats after treatment with EEDD. CONCLUSION: Here in, we found that Dryopteris dilatata could be used as nutraceuticals in the prevention and treatment of diabetes and its related complications through positively modulating oxidative stress and liver and kidney inflammatory markers.

Gastric bypass prevents diabetes in genetically modified mice and chemically induced diabetic mice.

Obese subjects have increase probabilities of developing type 2 diabetes (T2D). In this study, we sought to determine whether gastric bypass prevents the progression of prediabetes to overt diabetes in genetically modified mice and chemically induced diabetic mice. Roux-en-Y gastric bypass (RYGB) was performed in C57BL/KsJ-db/db null (BKS-db/db,) mice, high-fat diet (HFD)-fed NONcNZO10/LtJ (NZO) mice, C57BL/6 db/db null (B6-db/db) mice and streptozotocin (STZ)-induced diabetic mice. Food consumption, body weight, fat mass, fast blood glucose level, circulating insulin and adiponectin and glucose tolerance test were analyzed. The liver and pancreatic tissues were subjected to H&E and immunohistochemistry staining and islet cells to flow cytometry for apoptotic analysis. RYGB resulted in sustained normoglycemia and improved glucose tolerance in young prediabetic BKS-db/db mice (at the age of 6 weeks with hyperglycemia and normal insulinemia) and HFD-fed NZO and B6-db/db mice. Remarkably, RYGB improved liver steatosis, preserved the pancreatic ß-cells and reduced ß-cell apoptosis with increases in circulating insulin and adiponectin in young prediabetic BKS-db/db mice. However, RYGB neither reversed hyperglycemia in adult diabetic BKS-db/db mice (12 weeks old) nor attenuated hyperglycemia in STZ-induced diabetic mice. These results demonstrate that gastric bypass improves hyperglycemia in genetically modified prediabetic mice; however, it should be performed prior to ß-cells exhaustion.

Protective Role of Recombinant Human Thrombomodulin in Diabetes Mellitus.

Diabetes mellitus is a global threat to human health. The ultimate cause of diabetes mellitus is insufficient insulin production and secretion associated with reduced pancreatic ß-cell mass. Apoptosis is an important and well-recognized mechanism of the progressive loss of functional ß-cells. However, there are currently no available antiapoptotic drugs for diabetes mellitus. This study evaluated whether recombinant human thrombomodulin can inhibit ß-cell apoptosis and improve glucose intolerance in a diabetes mouse model. A streptozotocin-induced diabetes mouse model was prepared and treated with thrombomodulin or saline three times per week for eight weeks. The glucose tolerance and apoptosis of ß-cells were evaluated. Diabetic mice treated with recombinant human thrombomodulin showed significantly improved glucose tolerance, increased insulin secretion, decreased pancreatic islet areas of apoptotic ß-cells, and enhanced proportion of regulatory T cells and tolerogenic dendritic cells in the spleen compared to counterpart diseased mice treated with saline. Non-diabetic mice showed no changes. This study shows that recombinant human thrombomodulin, a drug currently used to treat patients with coagulopathy in Japan, ameliorates glucose intolerance by protecting pancreatic islet ß-cells from apoptosis and modulating the immune response in diabetic mice. This observation points to recombinant human thrombomodulin as a promising antiapoptotic drug for diabetes mellitus.

The promise(s) of mesenchymal stem cell therapy in averting preclinical diabetes: lessons from in vivo and in vitro model systems.

Obesity (Ob) poses a significant risk factor for the onset of metabolic syndrome with associated complications, wherein the Mesenchymal Stem Cell (MSC) therapy shows pre-clinical success. Here, we explore the therapeutic applications of human Placental MSCs (P-MSCs) to address Ob-associated Insulin Resistance (IR) and its complications. In the present study, we show that intramuscular injection of P-MSCs homed more towards the visceral site, restored HOMA-IR and glucose homeostasis in the WNIN/GR-Ob (Ob-T2D) rats. P-MSC therapy was effective in re-establishing the dysregulated cytokines. We report that the P-MSCs activates PI3K-Akt signaling and regulates the Glut4-dependant glucose uptake and its utilization in WNIN/GR-Ob (Ob-T2D) rats compared to its control. Our data reinstates P-MSC treatment's potent application to alleviate IR and restores peripheral blood glucose clearance evidenced in stromal vascular fraction (SVF) derived from white adipose tissue (WAT) of the WNIN/GR-Ob rats. Gaining insights, we show the activation of the PI3K-Akt pathway by P-MSCs both in vivo and in vitro (palmitate primed 3T3-L1 cells) to restore the insulin sensitivity dysregulated adipocytes. Our findings suggest a potent application of P-MSCs in  pre-clinical/Ob-T2D management.

Oral Fc-Coupled Preproinsulin Achieves Systemic and Thymic Delivery Through the Neonatal Fc Receptor and Partially Delays Autoimmune Diabetes.

Tolerogenic vaccinations using beta-cell antigens are attractive for type 1 diabetes prevention, but clinical trials have been disappointing. This is probably due to the late timing of intervention, when multiple auto-antibodies are already present. We therefore devised a strategy to introduce the initiating antigen preproinsulin (PPI) during neonatal life, when autoimmunity is still silent and central tolerance mechanisms, which remain therapeutically unexploited, are more active. This strategy employs an oral administration of PPI-Fc, i.e. PPI fused with an IgG Fc to bind the intestinal neonatal Fc receptor (FcRn) that physiologically delivers maternal antibodies to the offspring during breastfeeding. Neonatal oral PPI-Fc vaccination did not prevent diabetes development in PPI T-cell receptor-transgenic G9C8.NOD mice. However, PPI-Fc was efficiently transferred through the intestinal epithelium in an Fc- and FcRn-dependent manner, was taken up by antigen presenting cells, and reached the spleen and thymus. Although not statistically significant, neonatal oral PPI-Fc vaccination delayed diabetes onset in polyclonal Ins2-/-.NOD mice that spontaneously develop accelerated diabetes. Thus, this strategy shows promise in terms of systemic and thymic antigen delivery via the intestinal FcRn pathway, but the current PPI-Fc formulation/regimen requires further improvements to achieve diabetes prevention.

Asparaginyl Ligase-Catalyzed One-Step Cell Surface Modification of Red Blood Cells.

Red blood cells (RBCs) can serve as vascular carriers for drugs, proteins, peptides, and nanoparticles. Human RBCs remain in the circulation for ∼120 days, are biocompatible, and are immunologically largely inert. RBCs are cleared by the reticuloendothelial system and can induce immune tolerance to foreign components attached to the RBC surface. RBC conjugates have been pursued in clinical trials to treat cancers and autoimmune diseases and to correct genetic disorders. Still, most methods used to modify RBCs require multiple steps, are resource-intensive and time-consuming, and increase the risk of inflicting damage to the RBCs. Here, we describe direct conjugation of peptides and proteins onto the surface of RBCs in a single step, catalyzed by a highly efficient, recombinant asparaginyl ligase under mild, physiological conditions. In mice, the modified RBCs remain intact in the circulation, display a normal circulatory half-life, and retain their immune tolerance-inducing properties, as shown for protection against an accelerated model for type 1 diabetes. We conjugated different nanobodies to RBCs with retention of their binding properties, and these modified RBCs can target cancer cells in vitro. This approach provides an appealing alternative to current methods of RBC engineering. It provides ready access to more complex RBC constructs and highlights the general utility of asparaginyl ligases for the modification of native cell surfaces.

Multi-strain probiotic supplement attenuates streptozotocin-induced type-2 diabetes by reducing inflammation and ß-cell death in rats.

Probiotics are health beneficial bacterial populations colonizing the human gut and skin. Probiotics are believed to be involved in immune system regulation, gut microbiota stabilization, prevention of infectious diseases, and adjustments of host metabolic activities. Probiotics such as Lactobacillus and Bifidobacterium affect glycemic levels, blood lipids, and protein metabolism. However, the interactions between probiotics and metabolic diseases as well as the underlying mechanisms remain unclear. We used streptozotocin (STZ)-induced diabetic animal models to study the effect of ProbiogluTM, a multi-strain probiotic supplement including Lactobaccilus salivarius subsp. salicinius AP-32, L. johnsonii MH-68, L. reuteri GL-104, and Bifidobacterium animalis subsp. lactis CP-9, on the regulation of physiochemical parameters related to type-2 diabetes. Experimental rats were randomly assigned into five groups, control group, streptozotocin (STZ)-treated rats (STZ group), STZ + 1× ProbiogluTM group, STZ + 5× ProbiogluTM group, and STZ + 10× ProbiogluTM group, and physiological data were measured at weeks 0, 2, 4, 6, and 8. Our results indicate that supplementation with ProbiogluTM significantly improved glucose tolerance, glycemic levels, insulin levels, and insulin resistance (HOMA-IR). Furthermore, we observed reduction in urea and blood lipid levels, including low-density lipoprotein (LDL), triglycerides (TG), and total cholesterol (TC). ProbiogluTM administration increased the ß-cell mass in STZ-induced diabetic animal models, whereas it reduced the levels of proinflammatory cytokines TNF-α, IL-6, and IL-1ß. In addition, the enhancement of oxidative stress biomarkers and superoxide dismutase (SOD) activities was associated with a decrease in malondialdehyde (MDA) levels. We conclude that ProbiogluTM attenuates STZ-induced type-2 diabetes by protecting ß-cells, stabilizing glycemic levels, and reducing inflammation. Among all probiotic treating groups, the 10×ProbiogluTM treatment revealed the best results. However, these experimental results still need to be validated by different animal models of type-2 diabetes and human clinical trials in the future.