Type 2 Diabetes Mellitus Rat Model Research Articles

Oridonin attenuates diabetes‑induced renal fibrosis via the inhibition of TXNIP/NLRP3 and NF‑κB pathways by activating PPARγ in rats.

Oridonin possesses remarkable anti-inflammatory, immunoregulatory properties. However, the renoprotective effects of Oridonin and the underlying molecular mechanisms have not been explored in Diabetic Nephropathy (DN). We hypothesized that Oridonin could ameliorate diabetes‑induced renal fibrosis. We used streptozocin (STZ)-induced diabetic rats combined high-fat diet to establish a type 2 diabetes mellitus (T2DM) animal model, and then treated with Oridonin (10,20mg/kg/day) for two weeks. Kidney function and renal fibrosis were assessed. We also treated high glucose-induced human renal proximal tubule epithelial cells (HK-2) with Oridonin. In addition, the expression of inflammatory factors and fibrotic markers were analyzed. Oridonin treatment preserved kidney function and markedly limited the renal fibrosis size in diabetic rats. The renal fibrotic markers were inhibited in the 10mg/kg/day group and 20mg/kg/day group compared to the T2DM group. Moreover, the expression levels of TXNIP/NLRP3 and NF‑κB pathway were decreased and the level of PPARγ were increased in the Oridonin treatment group compared to non-treated group. In vitro, intervention of PPARγ could significantly regulate the effect of Oridonin on the high glucose-induced inflammatory changes in HK-2. Oridonin reduces renal fibrosis and preserves kidney function via the inhibition of TXNIP/NLRP3 and NF‑κB pathway by activating PPARγ in T2DM rat model, which indicates potential therapeutic effect of Oridonin on DN.

Transcriptomics reveals dynamic changes in the “gene profiles” of rat supraspinatus tendon at three different time points after diabetes induction

ObjectiveThere is increasing evidence that type 2 diabetes mellitus (T2DM) is an independent risk factor for the occur of tendinopathy. Therefore, this study is the first to explore the dynamic changes of the “gene profile” of supraspinatus tendon in rats at different time points after T2DM induction through transcriptomics, providing potential molecular markers for exploring the pathogenesis of diabetic tendinopathy.MethodsA total of 40 Sprague-Dawley rats were randomly divided into normal (NG, n = 10) and T2DM groups (T2DM, n = 30) and subdivided into three groups according to the duration of diabetes: T2DM-4w, T2DM-8w, and T2DM-12w groups; the duration was calculated from the time point of T2DM rat model establishment. The three comparison groups were set up in this study, T2DM-4w group vs. NG, T2DM-8w group vs. NG, and T2DM-12w group vs. NG. Differentially expressed genes (DEGs) in 3 comparison groups were screened. The intersection of the three comparison groups’ DEGs was defined as key genes that changed consistently in the supraspinatus tendon after diabetes induction. Cluster analysis, gene ontology (GO) functional annotation analysis and Kyoto encyclopedia of genes and genomes (KEGG) functional annotation and enrichment analysis were performed for DEGs.ResultsT2DM-4w group vs. NG, T2DM-8w group vs. NG, and T2DM-12w group vs. NG detected 519 (251 up-regulated and 268 down-regulated), 459 (342 up-regulated and 117 down-regulated) and 328 (255 up-regulated and 73 down-regulated) DEGs, respectively. 103 key genes of sustained changes in the supraspinatus tendon following induction of diabetes, which are the first identified biomarkers of the supraspinatus tendon as it progresses through the course of diabetes.The GO analysis results showed that the most significant enrichment in biological processes was calcium ion transmembrane import into cytosol (3 DEGs). The most significant enrichment in cellular component was extracellular matrix (9 DEGs). The most significant enrichment in molecular function was glutamate-gated calcium ion channel activity (3 DEGs). The results of KEGG pathway enrichment analysis showed that there were 17 major pathways (p < 0.05) that diabetes affected supratinusculus tendinopathy, including cAMP signaling pathway and Calcium signaling pathway.ConclusionsTranscriptomics reveals dynamic changes in the“gene profiles”of rat supraspinatus tendon at three different time points after diabetes induction. The 103 DEGs identified in this study may provide potential molecular markers for exploring the pathogenesis of diabetic tendinopathy, and the 17 major pathways enriched in KEGG may provide new ideas for exploring the pathogenesis of diabetic tendinopathy.

Petroleum ether extract of Schisandra sphenanthera prevents hyperglycemia and insulin resistance in association with modulation of sweet taste receptors and gut microbiota in T2DM rats

Ethnopharmacological relevanceSchisandra sphenanthera (Schisandra sphenanthera Rehd. et Wils.) is the dried mature fruit of Schisandra sphenanthera, a plant in the Magnoliaceae family. It was used in the treatment of diabetes mellitus in the Jade Fluid Decoction and the Xiaoke pills, which were recorded in ancient books. However, its mechanism of action in the treatment of type 2 diabetes mellitus (T2DM) was unclear and needs further study. Aim of the studyThis research aimed to investigate the chemical composition and lignan content of Schisandra sphenanthera petroleum ether parts (SPEP) and to evaluate the effects of SPEP on sweet taste receptors (STRs) and intestinal flora in rats on a high-fat diet (HFD). Additionally, the relationships between SPEP and hyperglycemia and insulin resistance were examined. Materials and methodsGC-MS was used to determine the chemical composition of SPEP, and HPLC was used to determine the lignin content. A combination of the HFD and the administration of streptozotocin (STZ) was employed to generate a rat model of T2DM. Petroleum ether extracts from Schisandra sphenanthera were used as the focus of the research to evaluate the effects of these extracts on the glucolipid metabolism of T2DM rats, as well as the underlying mechanisms. ResultsAnalysis of the GC-MS spectrum of SESP revealed a total of 58 compounds. HPLC analysis revealed that SPEP had the highest concentration of Schisandrin A and the lowest concentration of Schisandrol A. The drug administration intervention resulted in a significant decrease in body weight and pancreatic weight of diabetic rats compared to the Normal group. When compared to the Model group, the body weight of rats in the drug administration group and the Metformin group had a more moderate decrease, while the pancreatic weight and pancreatic-to-body ratio increased. The Model group shown significant increases in FBG, OGTT, GHb, TC, TG, LDL-C, ALT, AST, MDA, FINS, and NEFA, as well as significant decreases in HDL-C and SOD, when compared to the Normal group (P<0.05). The administration of each group was found to be significantly effective in decreasing FBG, OGTT, GHb, TC, TG, LDL-C, ALT, AST, MDA, FINS, NEFA, while increasing HDL-C and SOD when compared to the Model group. The application of SPEP had a positive impact on hepatocyte swelling, hepatocyte degeneration, and necrosis, as well as the morphological structure of pancreatic islet cells. Furthermore, the protein expression levels of T1R2, TRPM5 and GLP-1 in the small intestine of the Model group were reduced. After a period of six weeks, the protein expression levels began to align more closely with those of the Normal group of rats. Analysis of 16S rRNA sequencing revealed that the intestinal microbiota of diabetic rats was significantly disrupted, with a decrease in the abundance of the Firmicutes phylum and an increase in the abundance of the Bacteroidetes phylum. Furthermore, the composition of the dominant genus was distinct from that of the control group. After the drug intervention, the microbiota of diabetic rats was significantly altered, exhibiting a higher abundance and diversity, as well as a significant enrichment of the community. The SPEP treatment resulted in a significant increase in acetic acid, propionic acid, and butyric acid. ConclusionsThe findings of this research indicated that SPEP could be effective in treating T2DM through the regulation of STRs, the adjustment of disturbed metabolite levels, and the alteration of intestinal flora.

Diabetic Rats Induced Using a High-Fat Diet and Low-Dose Streptozotocin Treatment Exhibit Gut Microbiota Dysbiosis and Osteoporotic Bone Pathologies.

Type 2 diabetes mellitus (T2DM) presents a challenge for individuals today, affecting their health and life quality. Besides its known complications, T2DM has been found to contribute to bone/mineral abnormalities, thereby increasing the vulnerability to bone fragility/fractures. However, there is still a need for appropriate diagnostic approaches and targeted medications to address T2DM-associated bone diseases. This study aims to investigate the relationship between changes in gut microbiota, T2DM, and osteoporosis. To explore this, a T2DM rat model was induced by combining a high-fat diet and low-dose streptozotocin treatment. Our findings reveal that T2DM rats have lower bone mass and reduced levels of bone turnover markers compared to control rats. We also observe significant alterations in gut microbiota in T2DM rats, characterized by a higher relative abundance of Firmicutes (F) and Proteobacteria (P), but a lower relative abundance of Bacteroidetes (B) at the phylum level. Further analysis indicates a correlation between the F/B ratio and bone turnover levels, as well as between the B/P ratio and HbA1c levels. Additionally, at the genus level, we observe an inverse correlation in the relative abundance of Lachnospiraceae. These findings show promise for the development of new strategies to diagnose and treat T2DM-associated bone diseases.

Gualou Xiebai Banxia Decoction treats type 2 diabetes mellitus combined with acute myocardial infarction via chemerin/ CMKLR1/PPARα signaling pathway

This study aims to investigate the effects of Gualou Xiebai Banxia Decoction(GXBD) on type 2 diabetes mellitus(T2DM) combined with acute myocardial infarction(AMI) in rats via chemerin/chemokine-like receptor 1(CMKLR1)/peroxisome proliferator-activated receptor α(PPARα) signaling pathway, and to explore the mechanism of GXBD in alleviating glucose and lipid metabolism disorders. The SD rats were randomized into control, model, positive control, and low-and high-dose GXBD groups. The rat model of T2DM was established by administration with high-fat emulsion(HFE) by gavage and intraperitoneal injection with streptozotocin, and then coronary artery ligation was performed to induce AMI. The control and model groups were administrated with the equal volume of normal saline, and other groups were administrated with corresponding drugs by gavage. Changes in relevant metabolic indicators were assessed by ELISA and biochemical assays, and the protein levels of chemerin, CMKLR1, and PPARα in the liver, abdominal fat, and heart were determined by Western blot. The results showed that GXBD alleviated the myocardial damage and reduced the levels of blood lipids, myocardial enzymes, and inflammatory cytokines, while it did not lead to significant changes in blood glucose. Compared with the model group, GXBD down-regulated the expression of chemerin in peripheral blood and up-regulated the expression of cyclic adenosine monophosphate(cAMP) and protein kinase A(PKA) in the liver. After treatment with GXBD, the protein levels of chemerin and CMKLR1 in the liver, abdominal fat, and heart were down-regulated, while the protein levels of PPARα in the liver and abdominal fat were up-regulated. In conclusion, GXBD significantly ameliorated the disorders of glycolipid metabolism in the T2DM-AMI model by regulating the chemerin/CMKLR1/PPARα signaling pathway to exert a protective effect on the damaged myocardium. This study provides a theoretical basis for further clinical study of GXBD against T2DM-AMI and is a manifestation of TCM treatment of phlegm and turbidity causing obstruction at the protein level.

Secretome of Hypoxia-Preconditioned Mesenchymal Stem Cells Ameliorates Hyperglycemia in Type 2 Diabetes Mellitus Rats

Introduction: Type 2 diabetes mellitus (T2DM) is a prevalent form of diabetes that affects 90 - 95 % of all diabetic patients. Insulin sensitizers and insulin exogenous supply could temporarily ameliorate hyperglycaemia; however, they are accompanied by side effects. As a result, new approaches are required to address insulin resistance and regenerate beta cells simultaneously. The secretome of hypoxic mesenchymal stem cells (SH-MSCs) contains various growth factors and anti-inflammatory cytokines that could potentially enhance insulin resistance and improve pancreatic function. Objectives: In this study, we performed SH-MSCs infusion to ameliorate HFD-induced hyperglycaemia in T2DM rats. Methods: We created a T2DM rat model using a combination of a high-fat diet (HFD) and streptozotocin (STZ) administration. Then, we administered SH-MSCs injection at doses of 250 and 500 µL and assessed the therapeutic effects of SH-MSCs. We also investigated the potential underlying mechanisms involved. Results: The administration of SH-MSCs improved hyperglycemia in rats with T2DM. Infusion of SH-MSCs at 500 µL dose decreased homeostatic model assessment for insulin resistance (HOMA-IR). Histological analysis revealed that injection of SH-MSCs alleviated morphological damage of pancreas. SH-MSCs administration also inhibit the level of IL-6 and promote the expression of CD163 type 2 macrophage. Conclusion: The results of our study indicate that SH-MSCs have the potential to improve hyperglycemia and exert a protective effect on T2DM rats. HIGHLIGHTS Administration of SH-MSCs effectively improved hyperglycemia and decreased insulin resistance in TD2M rats through modulation of IL-6 levels and promotes the expression of CD163 type 2 macrophage Histological analysis demonstrated the protective effect of SH-MSCs on pancreatic morphology SH-MSCs hold promise for improving hyperglycemia, insulin resistance, and providing a protective effect in TD2M GRAPHICAL ABSTRACT

SIRT3 alleviates high glucose-induced chondrocyte injury through the promotion of autophagy and suppression of apoptosis in osteoarthritis progression

A growing amount of epidemiological evidence proposes diabetes mellitus (DM) to be an independent risk factor for osteoarthritis (OA). Sirtuin 3 (SIRT3), which is mainly located in mitochondria, belongs to the family of nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylases and is involved in the physiological and pathological processes of cell regulation. The aim of this study was to investigate the effects of SIRT3 on diabetic OA and underlying mechanisms in the prevention of type 2 DM (T2DM)-induced articular cartilage damage. High-fat and high-sugar diets combined with streptozotocin (STZ) injection were used for establishing an experimental T2DM rat model. The destabilization of medial meniscus (DMM) surgery was applied to induce the rat OA model. Primary rat chondrocytes were cultivated with a concentration of gradient glucose. Treatment with intra-articular injection of SIRT3 overexpression lentivirus was achieved in vivo, and intervention with SIRT3 knockdown was performed using siRNA transfection in vitro. High glucose content was found to activate inflammatory response, facilitate apoptosis, downregulate autophagy, and exacerbate mitochondrial dysfunction in a dose-dependent manner in rat chondrocytes, which can be deteriorated by SIRT3 knockdown. In addition, articular cartilage damage was found to be more severe in T2DM-OA rats than in DMM-induced OA rats, which can be mitigated by the intra-articular injection of SIRT3 overexpression lentivirus. Targeting SIRT3 is a potential therapeutic strategy for the alleviation of diabetic OA.

Allogeneic platelet-rich plasma inhibits ferroptosis in promoting wound repair of type 2 diabetic ulcers

Increasing evidence has revealed the emerging role of ferroptosis in the pathophysiology of type 2 diabetes mellitus (T2DM) and its complications. Platelet-rich plasma (PRP) has been demonstrated to facilitate the healing of T2DM ulcers. However, the mechanism by which PRP repairs T2DM ulcers remains unclear. Here, we sought to investigate the interaction between PRP and ferroptosis in repairing T2DM ulcers. The results showed that the cellular activity, proliferation, and migration of fibroblasts were down-regulated, and the cellular activity and normal function of vascular endothelial cells were impaired in the high glucose environment or under RSL3 conditions (a GSH peroxidase 4 inhibitor and ferroptosis inducer). Additionally, both cells experienced over-activation of multiple forms of reactive oxygen species (ROS) and lipid peroxidation. In the T2DM rat model, we observed a decreased rate of ulcer wound healing, impaired proliferative capacity, diminished vascular regeneration, and marked inflammation and hyperfibrosis. More importantly, there was typical damage to mitochondria, increased levels of iron ions, and consistent alterations in protein expression of ferroptosis-related factors. These factors include cyclooxygenase-2 (COX2), glutathione peroxidase 4 (GPX4), transferrin receptor (TFRC), and Solute Carrier Family 7 Member 11 (SLC7A11), among others. Due to the strong association between ferroptosis and T2DM ulcers, the use of allogeneic platelet-rich plasma (Al-PRP) exhibited physiological effects similar to those of the ferroptosis inhibitor Ferrostatin-1 (Fer-1). In vivo experiments, both drugs inhibited a range of impediments to wound healing caused by T2DM and ameliorated the adverse effects associated with ferroptosis. Moreover, Al-PRP attenuated the impairment of normal cellular function, activation of ROS and lipid peroxidation induced by high glucose or RSL3. These results suggested that ferroptosis was involved in the development of T2DM ulcers, which could be treated with Al-PRP by inhibiting ferroptosis, and inhibition of ferroptosis may be a suitable treatment strategy for T2DM ulcers.

Duodenal-jejunal bypass improves hypothalamic oxidative stress and inflammation in diabetic rats via glucagon-like peptide 1-mediated Nrf2/HO-1 signaling.

Type 2 diabetes mellitus (T2DM) is often accompanied by impaired glucose utilization in the brain, leading to oxidative stress, neuronal cell injury and infla-mmation. Previous studies have shown that duodenal jejunal bypass (DJB) surgery significantly improves brain glucose metabolism in T2DM rats, the role and the metabolism of DJB in improving brain oxidative stress and inflammation condition in T2DM rats remain unclear. To investigate the role and metabolism of DJB in improving hypothalamic oxidative stress and inflammation condition in T2DM rats. A T2DM rat model was induced via a high-glucose and high-fat diet, combined with a low-dose streptozotocin injection. T2DM rats were divided into DJB operation and Sham operation groups. DJB surgical intervention was carried out on T2DM rats. The differential expression of hypothalamic proteins was analyzed using quantitative proteomics analysis. Proteins related to oxidative stress, inflammation, and neuronal injury in the hypothalamus of T2DM rats were analyzed by flow cytometry, quantitative real-time PCR, Western blotting, and immunofluorescence. Quantitative proteomics analysis showed significant differences in proteins related to oxidative stress, inflammation, and neuronal injury in the hypothalamus of rats with T2DM-DJB after DJB surgery, compared to the T2DM-Sham groups of rats. Oxidative stress-related proteins (glucagon-like peptide 1 receptor, Nrf2, and HO-1) were significantly increased (P < 0.05) in the hypothalamus of rats with T2DM after DJB surgery. DJB surgery significantly reduced (P < 0.05) hypothalamic inflammation in T2DM rats by inhibiting the activation of NF-κB and decreasing the expression of interleukin (IL)-1β and IL-6. DJB surgery significantly reduced (P < 0.05) the expression of factors related to neuronal injury (glial fibrillary acidic protein and Caspase-3) in the hypothalamus of T2DM rats and upregulated (P < 0.05) the expression of neuroprotective factors (C-fos, Ki67, Bcl-2, and BDNF), thereby reducing hypothalamic injury in T2DM rats. DJB surgery improve oxidative stress and inflammation in the hypothalamus of T2DM rats and reduce neuronal cell injury by activating the glucagon-like peptide 1 receptor-mediated Nrf2/HO-1 signaling pathway.

Inhibition of PTEN promotes osteointegration of titanium implants in type 2 diabetes by enhancing anti-inflammation and osteogenic capacity of adipose-derived stem cells.

Background: The low osteogenic differentiation potential and attenuated anti-inflammatory effect of adipose-derived stem cells (ADSCs) from animals with type 2 diabetes mellitus (T2DM) limits osseointegration of the implant. However, the underlying mechanisms are not fully understood. Methods: Western blotting and qRT-PCR analyses were performed to investigate the effects of PTEN on the osteogenic capacity of ADSCs of T2DM rats (TADSCs). We conducted animal experiments in T2DM-Sprague Dawley (SD) rats to evaluate the osteogenic capacity of modified TADSC sheets in vivo. New bone formation was assessed by micro-CT and histological analyses. Results: In this study, adipose-derived stem cells of T2DM rats exhibited an impaired osteogenic capacity. RNA-seq analysis showed that PTEN mRNA expression was upregulated in TADSCs, which attenuated the osteogenic capacity of TADSCs by inhibiting the AKT/mTOR/HIF-1α signaling pathway. miR-140-3p, which inhibits PTEN, was suppressed in TADSCs. Overexpression or inhibition of PTEN could correspondingly reduce or enhance the osteogenic ability of TADSCs by regulating the AKT/mTOR/HIF-1α signaling pathway. TADSCs transfected with PTEN siRNA resulted in higher and lower expressions of genes encoded in M2 macrophages (Arg1) and M1 macrophages (iNOS), respectively. In the T2DM rat model, PTEN inhibition in TADSC sheets promoted macrophage polarization toward the M2 phenotype, attenuated inflammation, and enhanced osseointegration around implants. Conclusion: Upregulation of PTEN, which was partially due to the inhibition of miR-140-3p, is important for the attenuated osteogenesis by TADSCs owing to the inhibition of the AKT/mTOR/HIF-1α signaling pathway. Inhibition of PTEN significantly improves the anti-inflammatory effect and osteogenic capacity of TADSCs, thus promoting peri-implant bone formation in T2DM rats. Our findings offer a potential therapeutic approach for modifying stem cells derived from patients with T2DM to enhance osseointegration.

A New Concept in Antidiabetic Therapeutics: A Concerted Removal of Labile Iron and Intracellular Deposition of Zinc.

The inflammatory process is known to be an integral part of the pathophysiology of type 2 diabetes mellitus (T2DM). The "labile," redox-active iron, serving as a catalyst in Fenton reaction, producing the deleterious reactive oxygen species, triggering and maintaining inflammation, is hypothesized to play a causative role in this process. Concenter Biopharma continued the development of a new platform of iron chelators (Zygosids), first initiated at the Hebrew University of Jerusalem, Israel (HUJI), acting via the novel mechanism, based on a sequestration of the labile redox-active iron and its substitution by zinc or gallium. The mode of action of Zygosids is based on the higher affinity of the metal-binding moiety of the complex to Fe3+ in comparison to already bound ion, leading to rapid release of the ion of another metal and chelation of Fe3+. Concomitantly, zinc ion, released by the complex, is known for its antidiabetic and anti-inflammatory role. The therapeutic effect of zinc-desferrioxamine (Zygosid-50) and gallium-desferrioxamine, was tested on fat sand rat (Psammomys obesus) model of diet-induced T2DM and on Leprdb transgenic diabetic mice. Zygosids demonstrated an ability to noticeably reduce blood glucose and insulin levels and improve the lipid profile. Moreover, an ability to mitigate insulin resistance by >90% was shown on the sand rat model. In addition, a potent anti-inflammatory effect, expressed as a diminishment of the proinflammatory cytokines in tissue levels, was demonstrated. Zygosids demonstrated robust therapeutic efficacy in treatment of T2DM. Importantly, no adverse effects were detected, in all the experiments, indicating high safety profile.

Carvacrol improves blood lipid and glucose in rats with type 2 diabetes mellitus by regulating short-chain fatty acids and the GPR41/43 pathway.

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia and dyslipidemia. Carvacrol (CAR) has demonstrated the potential to mitigate dyslipidemia. This study aims to investigate whether CAR can modulate blood glucose and lipid levels in a T2DM rat model by regulating short-chain fatty acids (SCFAs) and the GPR41/43 pathway. The T2DM rat model was induced by a high-fat diet combined with low-dose streptozocin injection and treated with oral CAR and/or mixed antibiotics. Fasting blood glucose, oral glucose tolerance, and insulin tolerance tests were assessed. Serum lipid parameters, hepatic and renal function indicators, tissue morphology, and SCFAs were measured. In vitro, high glucose (HG)-induced IEC-6 cells were treated with CAR, and optimal CAR concentration was determined. HG-induced IEC-6 cells were treated with SCFAs or/and GPR41/43 agonists. CAR significantly reduced blood lipid and glucose levels, improved tissue damage, and increased SCFA levels in feces and GPR41/43 expression in colonic tissues of T2DM rats. CAR also attenuated HG-induced apoptosis of IEC-6 cells and enhanced GPR41/43 expression. Overall, these findings suggest that CAR alleviates blood lipid and glucose abnormalities in T2DM rats by modulating SCFAs and the GPR41/43 pathway.

Silicon-enriched meat positively improves plasma lipidaemia and lipoproteinaemia, LDLr, and insulin capability and the signalling pathway induced by an atherogenic diet in late-stage type 2 diabetes mellitus rats.

The impact of silicon as a functional ingredient in restructured meat (RM) on lipoprotein composition, metabolism, and oxidation on type 2 diabetes mellitus (T2DM) markers has never been studied. This study aims to evaluate the effect of silicon-enriched-meat consumption on lipidaemia, lipoprotein profile and metabolism, plasma arylesterase, and TBARS and their relationships with glycaemia, insulinaemia, and insulin-signaling markers in late-stage-T2DM rats fed a high-saturated-fat-high-cholesterol (HSFHC) diet. Saturated-fat diets with or without added cholesterol were formulated by mixing a 70% purified diet with 30% freeze-dried RM with or without added silicon. Three groups of seven Wistar rats each were tested. The ED group received the control RM in the framework of a high-saturated-fat diet as early-stage T2DM control. The other two groups received streptozotocin-nicotinamide administration together with the HSFHC diet containing the control RM (LD) or silicon-enriched RM (LD-Si). Scores were created to define the diabetic trend and dyslipidaemia. The ED rats showed hyperglycaemia, hyperinsulinaemia, hypertriglyceridaemia, and triglyceride-rich-VLDLs, suggesting they were in early-stage T2DM. LD rats presented hyperglycaemia, hypoinsulinaemia, and reduced HOMA-beta and insulin signaling markers typical of late-stage T2DM along with hypercholesterolaemia and high amounts of beta-VLDL, IDL, and LDL particles and low arylesterase activity. All these markers were significantly (p < 0.05) improved in LD-Si rats. The diabetic trend and diabetes dyslipidaemia scores showed a high and significant correlation (r = 0.595, p < 0.01). Silicon-enriched-meat consumption counterbalances the negative effects of HSFHC diets, functioning as an active hypolipemic, antioxidant, and antidiabetic dietary ingredient in a T2DM rat model, delaying the onset of late-stage diabetes.

Secretome hypoxia-mesenchymal stem cells decrease tumor necrosis factor-α and interleukin-18 in kidney of type 2 diabetes mellitus model rats

Background Type 2 diabetes mellitus (T2DM) is a chronic disease that affects millions of people worldwide and associated with an increased risk of kidney damage caused by prolonged inflammation. Secretome hypoxia- mesenchymal stem cells (SH-MSCs) have been investigated as a potential therapy for kidney inflammation in T2DM, due to their immunomodulatory properties and ability to promote tissue repair. In this study, we investigated the effects of SH-MSCs on tumor necrosis α (TNF-á) and interleukin-18 (IL-18) in the kidney of the T2DM model rats. MethodsA post-test-only control group involving 24 male Wistar rats. The rats were treated with a high-fat diet (HFD) for 4 weeks and streptozotocin-nicotinamide with sucrose solution for 5 days to induce T2DM animal models. Rats were randomly divided into four groups: healthy, control, and groups treated with SH-MSCs T1 and T2, with doses of 250 µL and 500 µL, respectively. TNF-α and IL-18 gene expression was measured by real time polymerase chain reaction (RT-PCR). One Way ANOVA and post-hoc LSD tests were used to determine the significant difference against all groups based on their quantitative measurement. ResultsAdministration of the SH-MSCs at a dose of 500µL (T2) was able to significantly reduce TNF-α and IL-18 gene expression when compared to control (T2DM rat without treatment) (p&lt;0.05), but not significantly when compared to healthy and SH-MSC at a dose of 250µL (T1) group (p &gt;0.05). ConclusionThis study demonstrated that the SH-MSCs decreased the levels of proinflammatory cytokines TNF-α and IL-18 gene expression in the kidney of T2DM model rats.

The role of MOTS-c-mediated antioxidant defense in aerobic exercise alleviating diabetic myocardial injury.

Myocardial remodeling and dysfunction are commonly observed in type 2 diabetes mellitus (T2DM). Aerobic exercise can partly alleviate diabetes-induced myocardial dysfunction through its antioxidant actions. MOTS-c is a potential exercise mimic. This study aimed to investigate the effects of MOTS-c on improving diabetic heart function and its mechanism and to identify whether MOTS-c improved antioxidant defenses due to aerobic exercise. Herein, we established a rat model of T2DM induced by high-fat diet combined with a low-dose streptozotocin injection. Interventions were performed using intraperitoneal injections of MOTS-c (i.p. 0.5mg/kg/day, 7days/week) or aerobic exercise training (treadmill, 20 m/min, 60 min/day, 5days/week) for 8 weeks. Myocardial ultrastructure was assessed using transmission electron microscopy (TEM), myocardial lipid peroxidation levels (MDA), superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT) levels were assessed using colorimetric methods, and molecular analyses including MOTS-c, Kelch-like ECH-associated protein 1 (Keap1), Nuclear factor E2-related factor 2 (Nrf2), adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)and phospho-AMPK (p-AMPK) were examined using Western blot. The results showed that MOTS-c, with or without exercise, reduced myocardial ultrastructural damage and improved glucolipid metabolism and cardiac function in T2DM. Furthermore, MOTS-c increased antioxidant markers such as SOD, CAT, and the protein expression of myocardial MOTS-c, Keap1, Nrf2, and p-AMPK. MOTS-c with exercise treatment reduced myocardial MDA and increased p-AMPK significantly comparing to only exercise or MOTS-c alone. Our findings suggest that MOTS-c may be a helpful supplement for overcoming exercise insufficiency and improving myocardial structure and function in diabetes.

Roux-en-Y Gastric Bypass Improves Insulin Sensitivity in Obese Rats with Type 2 Diabetes Mellitus by Regulating the Grin3a/AMPK Signal Axis in Hypothalamic Arcuate Nucleus.

The objective of this study was to explore the effects and related mechanisms of Roux-en-Y gastric bypass (RYGB) on insulin sensitivity in obese rats with type 2 diabetes mellitus (T2DM). The obese T2DM rat model was constructed by feeding a high-fat diet and injecting streptozotocin (STZ), and treated with RYGB. Grin3a shRNA was injected into the bilateral hypothalamic arcuate nucleus (ARC) to knockdown the Grin3a expression on T2DM rats. Eight weeks after operation, the body weight, fasting blood glucose (FBG), fasting serum insulin (FSI), homeostatic model assessment of insulin resistance (HOMA-IR), and plasma triglyceride (TG) levels were assessed. Hematoxylin & eosin (H&E) staining was adopted to observe the white adipose tissue (WAT) of rats. Western blot and qRT-PCR were used to detect the expression of Grin3a, adenosine 5' monophosphate-activated protein kinase (AMPK) and p-AMPK in ARC of rats. Later, the plasmid over-expressing or knocking down Grin3a was transfected into differentiated 3T3-L1 adipocytes, and the TG level and the formation of lipid droplets in adipocyte were assessed by TG kit and oil red O staining. The expression of lipogenic transcription factors in cells was detected by qRT-PCR. RYGB reduced FBG, FSI, HOMA-IR and plasma TG levels in T2DM rats while increasing Grin3a expression and p-AMPK/AMPK ratio in ARC. Knockdown of Grin3a not only reversed the decrease of FBG, FSI, HOMA-IR and plasma TG levels in T2DM rats induced by RYGB, but also reversed the up-regulation of p-AMPK/AMPK ratio in ARC affected by RYGB. Moreover, knocking down Grin3a significantly increased the TG level, promoted the formation of lipid droplets and up-regulated the expressions of lipogenic transcription factors in adipocytes. RYGB improved the insulin sensitivity, reduced the plasma TG level and lessens the fat accumulation in obese T2DM rats by regulating the Grin3a/AMPK signal in ARC.

The novel GLP-1/GIP dual agonist DA3-CH improves rat type 2 diabetes through activating AMPK/ACC signaling pathway.

Type 2 diabetes mellitus (T2DM) accounts for more than 95% of all diabetes. DA3-CH is a novel dual receptor agonist of glucagon like peptide-1 (GLP-1) and glucose dependent insulin stimulating polypeptide (GIP). The regulatory role of DA3-CH in T2DM has not been reported. T2DM rat model was established successfully with high sugar and fat feed and streptomycin (STZ) induction. The mRNA and protein expression were measured with RT-PCR and western blotting. The apoptosis level in the pancreatic tissue was evaluated with Tunel staining. Blood glucose, fat, and oxidative stress indicators were measured. DA3-CH greatly improved T2DM symptoms by reducing blood glucose, blood fat, pancreatic tissue injury, apoptosis, and oxidative stress condition. The inactivation of Adenylate activated protein kinase (AMPK)/acetyl CoA carboxylase (ACC) signaling pathway in T2DM rats was promoted by DA3-CH. The influence of DA3-CH was significantly reversed by Com-C, the inhibitor of AMPK/ACC signaling pathway. DA3-CH might improve T2DM through targeting AMPK/ACC signaling pathway. This study might provide a novel therapeutic strategy for the prevention and treatment of T2DM through targeting DA3-CH and AMPK/ACC signaling pathway.

Integrated 16S rRNA sequencing and nontargeted metabolomics analysis to reveal the mechanisms of Yu-Ye Tang on type 2 diabetes mellitus rats.

Yu-Ye Tang (YYT) is a classical formula widely used in treatment of type 2 diabetes mellitus (T2DM). However, the specific mechanism of YYT in treating T2DM is not clear. The aim of this study was to investigate the therapeutic effect of YYT on T2DM by establishing a rat model of T2DM. The mechanism of action of YYT was also explored through investigating gut microbiota and serum metabolites. The results indicated YYT had significant therapeutic effects on T2DM. Moreover, YYT could increase the abundance of Lactobacillus, Candidatus_Saccharimonas, UCG-005, Bacteroides and Blautia while decrease the abundance of and Allobaculum and Desulfovibrio in gut microbiota of T2DM rats. Nontargeted metabolomics analysis showed YYT treatment could regulate arachidonic acid metabolism, alanine, aspartate and glutamate metabolism, arginine and proline metabolism, glycerophospholipid metabolism, pentose and glucuronate interconversions, phenylalanine metabolism, steroid hormone biosynthesis, terpenoid backbone biosynthesis, tryptophan metabolism, and tyrosine metabolism in T2DM rats. In conclusion, our research showed that YYT has a wide range of therapeutic effects on T2DM rats, including antioxidative and anti-inflammatory effects. Furthermore, YYT corrected the altered gut microbiota and serum metabolites in T2DM rats. This study suggests that YYT may have a therapeutic impact on T2DM by regulating gut microbiota and modulating tryptophan and glycerophospholipid metabolism, which are potential key pathways in treating T2DM.

Oral administration of Bifidobacterium longum WHH2270 ameliorates type 2 diabetes in rats.

Accumulating evidence suggests that specific probiotic strains exert hypoglycemic effects on type 2 diabetes mellitus (T2DM), and probiotic strains within Bifidobacterium exhibit potential beneficial effects on T2DM. In this study, α-glucosidase inhibitory activities of 14 Bifidobacterium strains were assessed in vitro. The hypoglycemic effects of Bifidobacterium longum WHH2270 with high α-glucosidase inhibitory activity (42.03%) were then investigated in a high-fat diet/streptozotocin-induced T2DM rat model. Oral administration of WHH2270 (4 × 109 CFU/kg/day) for 8weeks significantly reversed the reduced body weight and ameliorated the levels of fasting blood glucose, serum triglyceride, serum total cholesterol, glucose tolerance, and insulin resistance in T2DM rats. Using 16S rRNA high-throughput sequencing of feces, WHH2270 was revealed to reshape the gut microbiome composition by increasing the abundances of Lactobacillus and Bifidobacterium and decreasing the abundances of UCG_005, Clostridium, and Faecalibacterium in T2DM rats. Besides, the fecal levels of short-chain fatty acids (SCFAs) including acetate, propionate, and butyrate were also elevated after WHH2270 administration. Moreover, the gene expressions of SCFA receptors FFAR2 and FFAR3 in the colon and pancreas of T2DM rats were restored by WHH2270 administration, accompanied by increased levels of serum acetate. In summary, these results provide evidence that WHH2270 has the potential to improve T2DM symptoms by alleviating hyperglycemia, which was associated with changes in the gut microbiome composition and SCFA production. PRACTICAL APPLICATION: Bifidobacterium longum WHH2270 with high α-glucosidase inhibitory activity may serve as a promising hypoglycemic agent for the treatment of T2DM.

Integrated 16S rRNA Sequencing and Untargeted Metabolomics Analysis to Reveal the Protective Mechanisms of Polygonatum Sibiricum Polysaccharide on Type 2 Diabetes Mellitus Model Rats.

Polygonatum sibiricum polysaccharide (PSP) can improve insulin resistance and inhibit oxidative stress. However, the detailed anti-diabetic mechanism of PSP is still poorly defined. In this study, the anti-diabetic, anti-inflammatory and anti-oxidative effects of PSP were evaluated on a type 2 diabetes mellitus (T2DM) rat model. Furthermore, we investigated the changes in gut microbiota and serum metabolites in T2DM rats after PSP treatment through 16S rRNA sequencing and untargeted metabolomics analyses. Our results showed that PSP exhibited significant anti-diabetic, anti-inflammatory and anti-oxidative effects on T2DM model rats. In addition, 16S rRNA sequencing showed that PSP treatment decreased the Firmicutes/Bacteroidetes ratio in the gut. At the genus level, PSP treatment increased the relative abundances of Blautia, Adlercreutzia, Akkermansia and Parabacteroides while decreasing Prevotella, Megamonas funiformis and Escherichia. Untargeted metabolomics analysis revealed that PSP treatment could affect 20 metabolites, including hexanoylglycine, (±)5(6)-DiHET, ecgonine, L-cysteine-S-sulfate, epitestosterone, (±)12(13)-DiHOME, glutathione, L-ornithine, D-mannose 6-phosphate, L-fucose, L-tryptophan, L-kynurenine, serotonin, melatonin, 3-hydroxyanthranilic acid, xylitol, UDP-D-glucuronate, hydroxyproline, 4-guanidinobutyric acid, D-proline in T2DM model rats, these metabolites are associated with arginine and proline metabolism, tryptophan metabolism, amino sugar and nucleotide sugar metabolism, pentose and glucuronate interconversions, glutathione metabolism, arginine biosynthesis, ascorbate and aldarate metabolism pathways. Spearman correlation analysis results showed that the modulatory effects of PSP on the arginine and proline metabolism, tryptophan metabolism, and glutathione metabolism pathways were related to the regulation of Prevotella, Megamonas funiformis, Escherichia, Blautia and Adlercreutzia. Our research revealed the therapeutic, anti-inflammatory and anti-oxidative effects of PSP on T2DM. The mechanisms of PSP on T2DM are associated with improving the dysbiosis of gut microbiota and regulating arginine and proline metabolism, tryptophan metabolism, and glutathione metabolism in serum.