Type 2 Diabetes Mellitus Mice Research Articles

Metabolic changes enhance necroptosis of type 2 diabetes mellitus mice infected with Mycobacterium tuberculosis.

Previously, we found that Mycobacterium tuberculosis (Mtb) infection in type 2 diabetes mellitus (T2DM) mice enhances inflammatory cytokine production which drives pathological immune responses and mortality. In the current study, using a T2DM Mtb infection mice model, we determined the mechanisms that make T2DM mice alveolar macrophages (AMs) more inflammatory upon Mtb infection. Among various cell death pathways, necroptosis is a major pathway involved in inflammatory cytokine production by T2DM mice AMs. Anti-TNFR1 antibody treatment of Mtb-infected AMs from T2DM mice significantly reduced expression of receptor interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like (MLKL) (necroptosis markers) and IL-6 production. Metabolic profile comparison of Mtb-infected AMs from T2DM mice and Mtb-infected AMs of nondiabetic control mice indicated that 2-ketohexanoic acid and deoxyadenosine monophosphate were significantly abundant, and acetylcholine and pyridoxine (Vitamin B6) were significantly less abundant in T2DM mice AMs infected with Mtb. 2-Ketohexanoic acid enhanced expression of TNFR1, RIPK3, MLKL and inflammatory cytokine production in the lungs of Mtb-infected nondiabetic mice. In contrast, pyridoxine inhibited RIPK3, MLKL and enhanced expression of Caspase 3 (apoptosis marker) in the lungs of Mtb-infected T2DM mice. Our findings demonstrate that metabolic changes in Mtb-infected T2DM mice enhance TNFR1-mediated necroptosis of AMs, which leads to excess inflammation and lung pathology.

Trefoil factor 3 can stimulate Th17 cell response in the development of type 2 diabetes mellitus

This study aims to evaluate the role of trefoil factor 3 (TFF3) peptides in type 2 diabetes mellitus (T2DM) from an inflammatory perspective. The focus was on exploring how TFF3 affects the function of T cells. TFF3 overexpression model was constructed using lentivirus in Jurkat cell lines. We evaluated the impact of TFF3 on the proliferation, apoptosis, and IL-17A levels of Jurkat cells cultured in high glucose. The T2DM model was induced in TFF3 knockout (KO) mice through streptozotocin combined with high-fat diet. The measurements included glucose tolerance, insulin tolerance, inflammation markers, Th17 cell proportion, and pancreatic pathological changes. The T2DM modeling led to splenomegaly in mice, and increased expression of TFF3 in their spleens. Overexpression of TFF3 increased the proportion of IL-17+ T cells and the levels of Th17-related cytokines in Jurkat cells. There was no difference in body weight and blood glucose levels between wild-type and TFF3 KO mice. However, T2DM mice lacking the TFF3 gene showed improved glucose utilization, ameliorated pancreatic pathology, decreased inflammation levels, and reduced Th17 cell ratio. TFF3 may be involved in the chronic inflammatory immune response in T2DM. Its mechanism may be related to the regulation of the RORγt/IL-17 signaling pathway and its impact on T cell proliferation and apoptosis.

Capsaicin reduces blood glucose and prevents prostate growth by regulating androgen, RAGE/IGF-1/Akt, TGF-β/Smad signalling pathway and reversing epithelial-mesenchymal transition in streptozotocin-induced diabetic mice.

Type 2 diabetes mellitus (T2DM) is a metabolic disease. Diabetes increases the risk of benign prostatic hyperplasia (BPH). Capsaicin is extracted from chili peppers and possesses many pharmacological properties, including anti-diabetic, pain-relieving, and anti-cancer properties. This study aimed to investigate the effects of capsaicin on glucose metabolism and prostate growth in T2DM mice and uncover the related mechanisms. Mice model of diabetes was established by administering a high-fat diet and streptozotocin. Oral administration of capsaicin for 2weeks inhibited prostate growth in testosterone propionate (TP)-treated mice. Furthermore, oral administration of capsaicin (5mg/kg) for 2weeks decreased fasting blood glucose, prostate weight, and prostate index in diabetic and TP-DM mice. Histopathological alterations were measured using hematoxylin & eosin (H&E) staining. The protein expression of 5α-reductase type II, androgen receptor (AR), and prostate-specific antigen (PSA) were upregulated in diabetic and TP-DM mice, but capsaicin reversed these effects. Capsaicin decreased the protein expression of p-AKT, insulin-like growth factor-1 (IGF-1), IGF-1R, and the receptor for advanced glycation end products (RAGE) in diabetic and TP-DM mice. Capsaicin also regulated epithelial-mesenchymal transition (EMT) and modulated the expression of fibrosis-related proteins, including E-cadherin, N-cadherin, vimentin, fibronectin, α-SMA, TGFBR2, TGF-β1, and p-Smad in TP-DM mice. In this study, capsaicin alleviated diabetic prostate growth by attenuating EMT. Mechanistically, capsaicin affected EMT by regulating RAGE/IGF-1/AKT, AR, and TGF-β/Smad signalling pathways. These results provide with new therapeutic approach for treating T2DM or T2DM-induced prostate growth.

Hypoglycemic effect and the mechanism of action of a polysaccharide from sweet corncob in a high-fat diet and streptozotocin-induced diabetic mice

Type 2 diabetes mellitus (T2DM) is a metabolic disease caused by a glycolipid metabolism disorder and islet β-cell dysfunction. SCP-80-I is a biologically active water-soluble polysaccharide isolated from sweet corncob, an agricultural byproduct. The hypoglycemic effects of SCP-80-I on T2DM mice and its mechanisms were investigated in this study. SCP-80-I was found to significantly reduce blood glucose and lipid deposition levels in T2DM mice, as well as decrease serum leptin and increase adiponectin secretion. Interestingly, real time-polymerase chain reaction (RT-PCR) and Western blotting results revealed that SCP-80-I could regulate the expression of several glycolipid metabolisms and insulin secretion genes and proteins, including 5'-AMP-activated protein kinase (AMPK), carnitine palmitoyltransferase I (CPT1), and acetyl coenzyme A carboxylase (ACC) in the liver and AMPK, sirtuin 1 (Sirt1), peroxisome proliferator-activated receptorycoactivator-1 (PGC-1α), and uncoupling protein 2 (UCP2) in the pancreas. To have a hypoglycemic effect, SCP-80-I regulated glycolipid metabolism and islet cell function in the liver by regulating the AMPK/ACC/CPT1 signaling pathway and the AMPK/Sirt1/PGC-1α and AMPK/Sirt1/UCP2 signaling pathways. These findings improve our understanding of polysaccharides derived from sweet corncob and the use of SCP-80-I in the production of hypoglycemic foods.

Achyranthes bidentata polysaccharide ameliorates type 2 diabetes mellitus by gut microbiota-derived short-chain fatty acids-induced activation of the GLP-1/GLP-1R/cAMP/PKA/CREB/INS pathway

Gut microbiota variances reflecting the severity type 2 diabetes mellitus (T2DM). Achyranthes bidentata polysaccharide (ABP) can regulate gut microbiota. However, the hypoglycemic effect and underlying mechanism of ABP remain unclear. Herein, we characterized the structure of ABP and revealed the hypoglycemic effect of ABP in mice with T2DM. ABP repaired the intestinal barrier in T2DM mice and regulated the composition and abundance of gut microbiota, especially increasing bacteria which producing short-chain fatty acids (SCFAs), then increasing glucagon-like peptide-1 (GLP-1) level. The abundance of these bacteria was positively correlated with blood lipid and INS levels, negatively correlated with FBG levels. Colon transcriptome data and immunohistochemistry demonstrated that the alleviating T2DM effect of ABP was related to activation of the GLP-1/GLP-1 receptor (GLP-1R)/cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/cAMP-response element binding protein (CREB)/INS pathway. Fecal microbiota transplantation (FMT) confirmed the transmissible efficacy of ABPs through gut microbiota. Overall, our research shows that ABP plays a hypoglycemic role by increasing gut microbiota-derived SCFAs levels, and activating the GLP-1/GLP-1R/cAMP/PKA/CREB/INS pathway, emphasizing ABP as promising T2DM therapeutic candidates.

The Effects of Ketogenic Diet on Brain Gene Expressions in Type 2 Diabetes Background

Type 2 diabetes mellitus (T2DM) is a major risk factor of a number of neurodegenerative diseases (NDDs). Ketogenic diet (KD) has significant beneficial effects on glycemic control and may act effectively against NDDs, but the mechanism remains unclear. In this study, we aimed to investigate the potential effects of KD on gene expressions in the brains of T2DM model mice. Male db/db mice at the age of 9 weeks were fed with KD or normal diet to the age of 6 months, and the whole brains were subjected to mRNA-seq analysis for differentially expressed genes. KD significantly lowered fasting glucose and body weights in db/db mice (P < 0.05), and the expression of 189 genes in the brain were significantly changed (P < 0.05, |log2| > 1). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that the differentially expressed genes upon KD are involved in inflammatory responses and the functions of biosynthesis. In inflammatory responses, NF-κB signaling pathway, viral protein interaction with cytokine and cytokine receptor, and cytokine-cytokine receptor interaction pathways were enriched, and in biosynthesis pathways, genes functioning in lipid and amino acid metabolism, protein synthesis, and energy metabolism were enriched. Moreover, consistent with the gene set enrichment analysis results, proteasomal activity measured biochemically were enhanced in KD-fed T2DM mice. These data may facilitate the understanding of how KD can be protective to the brain in T2DM background. KD could be a new strategy for the prevention of NDDs in T2DM patients.

1,25(OH)2D3 inhibits pancreatic stellate cells activation and promotes insulin secretion in T2DM.

To evaluate the effect and mechanism of 1,25(OH)2D3 on pancreatic stellate cells (PSCs) in type 2 diabetes mellitus (T2DM). A mouse model of T2DM was successfully established by high-fat diet (HFD) /streptozotocin (STZ) and administered 1,25(OH)2D3 for 3 weeks. Fasting blood glucose (FBG), glycated hemoglobin A1c (GHbA1c), insulin (INS) and glucose tolerance were measured. Histopathology changes and fibrosis of pancreas were examined by hematoxylin and eosin staining and Masson staining. Mouse PSCs were extracted, co-cultured with mouse insulinoma β cells (MIN6 cells) and treated with 1,25(OH)2D3. ELISA detection of inflammatory factor expression. Tissue reactive oxygen species (ROS) levels were also measured. Immunofluorescence or Western blotting were used to measure fibrosis and inflammation-related protein expression. PSCs activation and islets fibrosis in T2DM mice. Elevated blood glucose was accompanied by significant increases in serum inflammatory cytokines and tissue ROS levels. 1,25(OH)2D3 attenuated islet fibrosis by reducing hyperglycemia, ROS levels, and inflammatory factors expression. Additionally, the co-culture system confirmed that 1,25(OH)2D3 inhibited PSCs activation, reduced the secretion of pro-inflammatory cytokines, down-regulated the expression of fibrosis and inflammation-related proteins, and promoted insulin secretion. Our findings identify that PSCs activation contributes to islet fibrosis and β-cell dysfunction. 1,25(OH)2D3 exerts beneficial effects on T2DM potentially by inhibiting PSCs activation and inflammatory response, highlighting promising control strategies of T2DM by vitamin D.

NLRP3 inflammasome-mediated premature immunosenescence drives diabetic vascular aging dependent on the induction of perivascular adipose tissue dysfunction.

The vascular aging process accelerated by type 2 diabetes mellitus (T2DM) is responsible for the elevated risk of associated cardiovascular diseases (CVDs). Metabolic disorder-induced immune senescence has been implicated in multi-organ/tissue damage. Herein, we sought to determine the role of immunosenescence in diabetic vascular aging and to investigate the underlying mechanisms. Aging hallmarks of the immune system appear prior to the vasculature in streptozotocin (STZ)/high-fat diet (HFD)-induced T2DM mice or db/db mice. Transplantation of aged splenocytes or diabetic splenocytes into young mice triggered vascular senescence and injury compared to normal control splenocyte transfer. RNA-seq profile and validation in immune tissues revealed that the Toll-like receptor 4 (TLR4)- Nuclear factor-kappa B (NF-κB) -NLRP3 axis might be the mediator of diabetic premature immunosenescence. The absence of Nlrp3 attenuated immune senescence and vascular aging during T2DM. Importantly, senescent immune cells, particularly T cells, provoked perivascular adipose tissue (PVAT) dysfunction and alternations in its secretome, which in turn impair vascular biology. In addition, senescent immune cells may uniquely affect vasoconstriction via influencing PVAT. Lastly, rapamycin alleviated diabetic immune senescence and vascular aging, which may be partly due to NLRP3 signaling inhibition. These results indicated that NLRP3 inflammasome-mediated immunosenescence precedes and drives diabetic vascular aging. The contribution of senescent immune cells to vascular aging is a combined effect of their direct effects and induction of PVAT dysfunction, the latter of which can uniquely affect vasoconstriction. We further demonstrated that infiltration of senescent T cells in PVAT was increased and associated with PVAT secretome alterations. Our findings suggest that blocking the NLRP3 pathway may prevent early immunosenescence and thus mitigate diabetic vascular aging and damage, and targeting senescent T cells or PVAT might also be the potential therapeutic approach.

Targeting Molecular Mechanisms of Obesity- and Type 2 Diabetes Mellitus-Induced Skeletal Muscle Atrophy with Nerve Growth Factor.

Skeletal muscle plays a critical role in metabolic diseases, such as obesity and type 2 diabetes mellitus (T2DM). Muscle atrophy, characterized by a decrease in muscle mass and function, occurs due to an imbalance between the rates of muscle protein synthesis and degradation. This study aimed to investigate the molecular mechanisms that lead to muscle atrophy in obese and T2DM mouse models. Additionally, the effect of nerve growth factor (NGF) on the protein synthesis and degradation pathways was examined. Male mice were divided into three groups: a control group that was fed a standard chow diet, and two experimental groups that were fed a Western diet. After 8 weeks, the diabetic group was injected with streptozotocin to induce T2DM. Each group was then further divided into NGF-treated or non-treated control group. In the gastrocnemius muscles of the Western diet group, increased expressions of myostatin, autophagy markers, and ubiquitin ligases were observed. Skeletal muscle tissue morphology indicated signs of muscle atrophy in both obese and diabetic mice. The NGF-treated group showed a prominent decrease in the protein levels of myostatin and autophagy markers. Furthermore, the NGF-treated group showed an increased Cyclin D1 level. Western diet-induced obesity and T2DM may be linked to muscle atrophy through upregulation of myostatin and subsequent increase in the ubiquitin and autophagy systems. Moreover, NGF treatment may improve muscle protein synthesis and cell cycling.

Cholesterol 25-hydroxylase prevents type 2 diabetes mellitus induced cardiomyopathy by alleviating cardiac lipotoxicity

ObjectivesDiabetic cardiomyopathy (DCM) is the leading cause of mortality in type 2 diabetes mellitus (T2DM) patients, with its underlying mechanisms still elusive. This study aims to investigate the role of cholesterol-25-monooxygenase (CH25H) in T2DM induced cardiomyopathy. MethodsHigh fat diet combined with streptozotocin (HFD/STZ) were used to establish a T2DM model. CH25H and its product 25-hydroxycholesterol (25HC) were detected in the hearts of T2DM model. Gain- or loss-of-function of CH25H were performed by receiving AAV9-cTNT-CH25H or CH25H knockout (CH25H−/−) mice with HFD/STZ treatment. Cardiac function was evaluated using echocardiography, and cardiac tissues were collected for immunoblot analysis, histological assessment and quantitative polymerase chain reaction (qPCR). Mitochondrial morphology and function were evaluated using transmission electron microscopy (TEM) and Seahorse XF Cell Mito Stress Test Kit. RNA-sequence analysis was performed to determine the molecular changes associated with CH25H deletion. ResultsCH25H and 25HC were significantly decreased in the hearts of T2DM mice. CH25H−/− mice treated with HFD/STZ exhibited impaired mitochondrial function and structure, increased lipid accumulation, and aggregated cardiac dysfunction. Conversely, T2DM mice receiving AAV9-CH25H displayed cardioprotective effects. Mechanistically, RNA sequencing and qPCR analysis revealed that CH25H deficiency decreased peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and its target gene expression. Additionally, administration of ZLN005, a potent PGC-1α activator, partially protected against high glucose and palmitic acid induced mitochondria dysfunction and lipid accumulation in vitro. ConclusionOur study provides compelling evidence supporting the protective role of CH25H in T2DM-induced cardiomyopathy. Furthermore, the regulation of PGC-1α may be intricately involved in this cardioprotective process.

Static Strength Training Method for Type 2 Diabetic Mice.

The treatment of type 2 diabetes mellitus (T2DM) is a major difficulty in improving patient health. Exercise is one of the main interventions for T2DM. Static strength training is one of the key forms of traditional sports in China. Research shows that static strength training is an effective clinical method for T2DM intervention, but there is no experimental device suitable for static training in mice. One of the difficulties in moving from clinical to basic research is to design appropriate experimental devices. In order to further study the mechanism of static training intervention in T2DM, a simple method for making a static training device for mice is introduced in this paper. This device has the advantages of simple operation, cheap material, and high feasibility. Previous studies conducted under this protocol have shown that static training can effectively reduce blood glucose levels and improve the mitochondrial function of skeletal muscle cells in T2DM mice. The purpose of introducing this device is to promote research on the mechanism of traditional exercise in the intervention of T2DM and to lay a foundation for the quantitative intervention of exercise.

Correlation of Differentially Expressed lncRNAs with Intestinal Flora Imbalance, Small Intestinal Permeability, and Glucose Uptake in T2DM Mice.

Diabetes is a major global health concern. This study aimed to investigate the correlation between differentially expressed lncRNAs in mice with type 2 diabetes mellitus (T2DM) and alterations in the intestinal flora and intestinal pathology. A T2DM mouse model was constructed by feeding mice a high-fat diet. Serum fat metabolism-related indices and insulin levels were biochemically detected. Serum inflammatory factors (IL-1β, IL-6, TNF-α, IL-10) and endotoxin (LPS) were measured by ELISA. Histopathological changes in the small intestines of mice were observed by HE. The short-chain fatty acid (SCFA) content was analyzed using GC-MS. Analysis of altered intestinal flora in T2DM mice was performed using a 16sRNA sequencing assay. Differences in lncRNA expression profiles in small intestinal tissues were analyzed using RNA-seq assays. Spearman's correlation analysis was used to correlate the expression of candidate lncRNAs with changes in differential gut flora. Spearman's correlation analysis was used to analyze the correlation between the expression of candidate differentially expressed lncRNAs, small intestinal permeability, and glucose absorption. We found that serum levels of LPS, BUN, Scr, TC, TG, LDL-C, IL-1β, IL-6, and TNF-α were elevated and levels of HDL-C, insulin, and IL-10 were decreased in T2DM mice. The ileal enterochromes of T2DM mice were disorganized and broken, the number of enterochromes was reduced, the local epithelial cells were necrotic, and the plasma membrane layer was locally absent. In addition, the protein expression of ZO-1 and occludin was decreased, and the protein expression of SGLT-1 and GLUT-2 was elevated in the model group compared to the control group.The levels of Acetic acid, Propionic acid and Butyric acid were decreased and the levels of Isobutyric acid andIsovaleric acid were increased, the abundance of beneficial bacteria was decreased and the abundance of harmfulbacteria was increased in the feces of T2DM mice. RNA-seq identified nine differentially expressed lncRNAs (LINC00675, Gm33838, Gm11655, LOC6613926, LOC6613788, LOC6613791, LOC6613795, Arhgap27os3, and A330023F24Rik). In addition, we found significant correlations between differentially expressed lncRNAs and a variety of intestinal flora, as well as between small intestinal permeability and glucose absorption. A significant correlation was observed between differentially expressed lncRNAs in the intestinal tissues of T2DM mice and intestinal flora imbalance, small intestinal permeability, and glucose absorption.

The Effect of Canagliflozin on High-Density Lipoprotein Cholesterol and Angiopoietin-Like Protein 3 in Type 2 Diabetes Mellitus.

Diabetes mellitus is often accompanied by dyslipidemia. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, as a novel therapeutic agent for the treatment of type 2 diabetes mellitus (T2DM), have been reported to exert effects on lipid, while the results remain controversial. This study is aimed at exploring the effect of SGLT2 inhibitor canagliflozin on lipid profile. This study was a single-center, open-label, nonrandomized, prospective study. Metformin (500 mg three times per day) or canagliflozin (100 mg, once daily) was administered for 12 weeks. Fasting blood samples were collected before and 12 weeks after treatment. Serum lipid profile levels and angiopoietin-like protein 3 (ANGPTL3) were determined. In animal experiment, C57BL/6 J mice were divided into three groups including control, STZ + HFD, and STZ + HFD + canagliflozin. Lipid profile and plasma ANGPTL3 level were measured after 12 week's treatment. Moreover, the expression of ANGPTL3 was detected in the liver tissues. There was a decreased trend in low-density lipoprotein cholesterol (LDL-c) and triglycerides (TG) after canagliflozin treatment, while canagliflozin significantly increased high-density lipoprotein cholesterol (HDL-c) level and decreased plasma ANGPTL3 level. In addition, the expression of ANGPTL3 in liver tissues decreased obviously in diabetic mice with canagliflozin treatment. Canagliflozin increases HDL-c level and suppresses ANGPTL3 expression in patients with T2DM and diabetic mice. The reduction of ANGPTL3 may contribute to the increase of HDL-c. However, the specific mechanism needs further research. This trial is registered with ChiCTR1900021231.

Oxymatrine alleviates high-fat diet/streptozotocin-induced non-alcoholic fatty liver disease in C57BL/6 J mice by modulating oxidative stress, inflammation and fibrosis

Non-alcoholic fatty liver disease (NAFLD) represents a complex complication of type 2 diabetes mellitus (T2DM). Oxymatrine (OMT) is an alkaloid extracted from Sophora flavescens with broad pharmacological effects. However, there is currently a lack of research on OMT in the field of NAFLD. The present study aimed to explore the effects and underlying mechanisms of oxymatrine in treating T2DM with NAFLD. The T2DM mice model was induced by high-fat diet (HFD) combined with streptozotocin (STZ) injection in male C57BL/6 J mice. Animals were randomly divided into four groups (n = 8): Control group, DC group, OMT-L group (45 mg/kg i.g.), and OMT-H group (90 mg/kg, i.g.). The drug was administered once a day for 8 weeks. In addition, HepG2 hepatocytes were incubated with palmitic acid (PA) to establish a fatty liver cell model. Treated with OMT, the body weight and fasting blood glucose (FBG) of DC mice were reduced and the liver organ coefficient was significantly optimized. Meanwhile, OMT markedly enhanced the activities of key antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), and also reduced malondialdehyde (MDA) levels. These biochemical alterations were accompanied by noticeable improvements in liver histopathology. Furthermore, OMT down-regulated the expression of NOD-like receptor protein 3 (NLRP3), interleukin-1β (IL-1β), transforming growth factor-β1 (TGF-β1) and collagen I significantly, highlighting its potential in modulating inflammatory and fibrotic pathways. In conclusion, OMT improved liver impairment effectively in diabetic mice by suppressing oxidative stress, inflammation and fibrosis. These results suggest that OMT may represent a novel therapy for NAFLD with diabetes.

BBR affects macrophage polarization via inhibition of NF-κB pathway to protect against T2DM-associated periodontitis.

Periodontitis is intimately associated with the development of various systemic diseases, among which type 2 diabetes mellitus (T2DM) has a bidirectional relationship with the pathogenesis of periodontitis. The objective of the present work was to investigate the role of berberine (BBR) in periodontitis with T2DM and related mechanisms. The mRNA expression of macrophage polarization-related factors in the microenvironment of periodontal inflammation was detected using real-time quantitative PCR (RT-qPCR). The experimental periodontitis model was constructed in wild-type (WT) and T2DM (db/db) mice, which were administered BBR after 7 days of modeling. Alveolar bone loss (ABL) in each group of mice was measured utilizing micro-computed tomography images. RT-qPCR was performed to analyze the levels of macrophage polarization-related factors in mouse gingiva. Lastly, using western blotting and RT-qPCR, the signaling pathway of BBR affecting macrophage polarization in the microenvironment of periodontitis was explored. BBR inhibited M1 polarization and stimulated M2 polarization in the periodontitis microenvironment. BBR decreased ABL in the WT and T2DM periodontitis models. And BBR reduced the production of proinflammatory cytokines and increased anti-inflammatory cytokine expression in the gingiva of WT and T2DM model mice. Ultimately, BBR mediates its anti-inflammatory effects on periodontitis through inhibition of the NF-κB pathway. BBR had a therapeutic effect on T2DM-associated periodontitis via inhibiting the NF-κB pathway to affect macrophage polarization, which may have implications for the new pharmacological treatment of T2DM-associated periodontitis.

Platycodin D Ameliorates Cognitive Impairment in Type 2 Diabetes Mellitus Mice via Regulating PI3K/Akt/GSK3β Signaling Pathway.

Objectives: The aim of this study was to investigate the ameliorative effect of platycodin D (PD) on cognitive dysfunction in type 2 diabetes mellitus (T2DM) and its potential molecular mechanisms of action in vivo and in vitro. Materials and methods: An animal model of cognitive impairment in T2DM was established using a single intraperitoneal injection of streptozotocin (100 mg/kg) after 8 weeks of feeding a high-fat diet to C57BL/6 mice. In vitro, immunofluorescence staining and Western blot were employed to analyze the effects of PD on glucose-induced neurotoxicity in mouse hippocampal neuronal cells (HT22). Results: PD (2.5 mg/kg) treatment for 4 weeks significantly suppressed the rise in fasting blood glucose in T2DM mice, improved insulin secretion deficiency, and reversed abnormalities in serum triglyceride, cholesterol, low-density lipoprotein, and high-density lipoprotein levels. Meanwhile, PD ameliorated choline dysfunction in T2DM mice and inhibited the production of oxidative stress and apoptosis-related proteins of the caspase family. Notably, PD dose-dependently prevents the loss of mitochondrial membrane potential, promotes phosphorylation of phosphatidylinositol 3 kinase and protein kinase B (Akt) in vitro, activates glycogen synthase kinase 3β (GSK3β) expression at the Ser9 site, and inhibits Tau protein hyperphosphorylation. Conclusions: These findings clearly indicated that PD could alleviate the neurological damage caused by T2DM, and the phosphorylation of Akt at Ser473 may be the key to its effect.

Changed regulation of granulocyte NADPH oxidase activity in the mouse model of obesity-induced type 2 diabetes mellitus

NADPH oxidase is a target of hyperglycemia in type 2 diabetes mellitus (T2DM), which causes dysregulation of enzyme. Alterations in regulation of NADPH oxidase activity mediated receptor and non-receptor signaling in bone marrow granulocytes of mice with obesity-induced T2DM were studied. The animals fed high fat diet (516 kcal/100 g) for 16 weeks. NADPH oxidase-related generation of reactive species (RS) at normo- and hyperthermia was estimated using chemiluminescent analysis. The redox status of the cells was assessed by Redox Sensor Red CC-1. Baseline biochemical indicators in blood (glucose, cholesterol, HDL and LDL levels) were significant higher in T2DM mice versus controls. Using specific inhibitors, signaling mediated by formyl peptide receptors (FPRs) to NADPH oxidase was shown to involve PLC, PKC, cytochrome p450 in both control and T2DM groups and PLA2 in controls. In T2DM regulation of NADPH oxidase activity via mFpr1, a high-affinity receptors, occurred with a significant increase of the role of PKC isoforms and suppression of PLA2 participation. Significant differences between this regulation via mFpr2, low-affinity receptors, were not found. Non-receptor activation of NADPH oxidase with ionomycin (Ca2+ ionophore) or phorbol ester (direct activator of PKC isoforms) did not revealed differences in the kinetic parameters between groups at 37 °C and 40 °C. When these agents were used together (synergistic effect), lower sensitivity of cells to ionophore was observed in T2DM at both temperatures. Redox status in responses to opsonized zymosan was higher in T2DM mice at 37 °C and similar to control levels at 40 °C. ROC-analysis identified Tmax, RS production and effect of opsonized zymosan as the most significant predictors for discriminating between groups. It was concluded that Ca2+-dependent/PKC-mediated regulation of NADPH oxidase activity was altered in BM granulocytes from diabetic mice.

Artemisinin ameliorates cognitive decline by inhibiting hippocampal neuronal ferroptosis via Nrf2 activation in T2DM mice

BackgroundNeuronal ferroptosis plays a critical role in the pathogenesis of cognitive deficits. The present study explored whether artemisinin protected type 2 diabetes mellitus (T2DM) mice from cognitive impairments by attenuating neuronal ferroptosis in the hippocampal CA1 region.MethodsSTZ-induced T2DM mice were treated with artemisinin (40 mg/kg, i.p.), or cotreated with artemisinin and Nrf2 inhibitor MEL385 or ferroptosis inducer erastin for 4 weeks. Cognitive performance was determined by the Morris water maze and Y maze tests. Hippocampal ROS, MDA, GSH, and Fe2+ contents were detected by assay kits. Nrf2, p-Nrf2, HO-1, and GPX4 proteins in hippocampal CA1 were assessed by Western blotting. Hippocampal neuron injury and mitochondrial morphology were observed using H&E staining and a transmission electron microscope, respectively.ResultsArtemisinin reversed diabetic cognitive impairments, decreased the concentrations of ROS, MDA and Fe2+, and increased the levels of p-Nr2, HO-1, GPX4 and GSH. Moreover, artemisinin alleviated neuronal loss and ferroptosis in the hippocampal CA1 region. However, these neuroprotective effects of artemisinin were abolished by Nrf2 inhibitor ML385 and ferroptosis inducer erastin.ConclusionArtemisinin effectively ameliorates neuropathological changes and learning and memory decline in T2DM mice; the underlying mechanism involves the activation of Nrf2 to inhibit neuronal ferroptosis in the hippocampus.Graphical

Curative effect of the total saponins of Panax japonicus (TSPJ) on type 2 diabetes: Focusing on VEGFA

ObjectiveThe objective of this study was to assess the impact of the total saponins of Panax japonicus (TSPJ) on Type 2 diabetes mellitus (T2DM). ResultsThe intervention of TSPJ was found to have the ability to reverse physiological indicators associated with T2DM, while also enhancing the expression of genes involved in glucose metabolism and intestinal homeostasis. Additionally, alterations in the composition of the gut microbiota were observed. Based on the findings of experimental results and network pharmacology analysis, it is evident that vascular endothelial growth factor A (VEGFA) serves as a prominent shared target between TSPJ and diabetes. The outcomes observed in T2DM mice overexpressing VEGFA align with those observed in T2DM mice treated with TSPJ. ConclusionsTSPJ administration and VEGFA overexpression yield similar effects on T2DM in mice. Thus, in terms of mechanism, by upregulating the expression of VEGFA, TSPJ may ameliorate metabolic imbalance, preserve intestinal homeostasis, and lessen the symptoms of type 2 diabetes. The findings demonstrated the viability of using VEGFA as a type 2 diabetes therapy option and offered important insights into the therapeutic mechanisms by TSPJ in the management of T2DM. To determine the exact mechanisms behind the effects of TSPJ and VEGFA and to assess their potential therapeutic uses, more research efforts are necessary.

Label-free analysis of the β-hydroxybutyricacid drug on mitochondrial redox states repairment in type 2 diabetic mice by resonance raman scattering

BackgroundMitochondrial redox imbalance underlies the pathophysiology of type2 diabetes mellitus (T2DM), and is closely related to tissue damage and dysfunction. Studies have shown the beneficial effects of dietary strategies that elevate β-hydroxybutyrate (BHB) levels in alleviating T2DM. Nevertheless, the role of BHB has not been clearly elucidated. MethodsWe performed a spectral study to visualize the preventive effects of BHB on blood and multiorgan mitochondrial redox imbalance in T2DM mice via using label-free resonance Raman spectroscopy (RRS), and further explored the impact of BHB therapy on the pathology of T2DM mice by histological and biochemical analyses. FindingsOur data revealed that RRS-based mitochondrial redox states assay enabled clear and reliable identification of the improvement of mitochondrial redox imbalance by BHB, evidenced by the reduction of Raman peak intensity at 750 cm−1, 1128 cm−1 and 1585 cm−1 in blood, tissue as well as purified mitochondria of db/db mice and the increase of tissue mitochondrial succinic dehydrogenase (SDH) staining after BHB treatment. Exogenous supplementation of BHB was also found to attenuate T2DM pathology related to mitochondrial redox states, involving organ injury, blood glucose control, insulin resistance and systemic inflammation. InterpretationOur findings provide strong evidence for BHB as a potential therapeutic strategy targeting mitochondria for T2DM.