STZ-induced Mice Research Articles

PIAS1 impedes vascular endothelial injury and atherosclerotic plaque formation in diabetes by blocking the RUNX3/TSP-1 axis.

The protein PIAS1 functions as a type of ubiquitin-protease, which is known to play an important regulatory role in various diseases, including cardiovascular diseases and cancers. Its mechanism of action primarily revolves around regulating the transcription, translation, and modification of target proteins. This study investigates role and mechanism of PIAS1 in the RUNX3/TSP-1 axis and confirms its therapeutic effects on diabetes-related complications in animal models. A diabetic vascular injury was induced in human umbilical vein endothelial cells (HUVECs) by stimulation with H2O2 and advanced glycation end product (AGE), and a streptozotocin (STZ)-induced mouse model of diabetes was constructed, followed by detection of endogenous PIAS1 expression and SUMOylation level of RUNX3. Effects of PIAS1 concerning RUNX3 and TSP-1 on the HUVEC apoptosis and inflammation were evaluated using the ectopic expression experiments. Down-regulated PIAS1 expression and SUMOylation level of RUNX3 were identified in the H2O2- and AGE-induced HUVEC model of diabetic vascular injury and STZ-induced mouse models of diabetes. PIAS1 promoted the SUMOylation of RUNX3 at the K148 site of RUNX3. PIAS1-mediated SUMOylation of RUNX3 reduced RUNX3 transactivation activity, weakened the binding of RUNX3 to the promoter region of TSP-1, and caused downregulation of TSP-1 expression. PIASI decreased the expression of TSP-1 by inhibiting H2O2- and AGE-induced RUNX3 de-SUMOylation, thereby arresting the inflammatory response and apoptosis of HUVECs. Besides, PIAS1 reduced vascular endothelial injury and atherosclerotic plaque formation in mouse models of diabetes by inhibiting the RUNX3/TSP-1 axis. Our study proved that PIAS1 suppressed vascular endothelial injury and atherosclerotic plaque formation in mouse models of diabetes via the RUNX3/TSP-1 axis.

Hypoglycaemic and hypolipidemic activities of total flavonoids from Nymphaea candida flowers on diabetic mice

This study aimed to investigate the hypoglycaemic and hypolipidemic activities of total flavonoids from Nymphaea candida (NCTF). The result showed that NCTF could significantly ameliorate various indicators such as FBG, OGTT, TC, TG, LDL-C, and HDL-C in ALX-induced diabetic mice compared with the model group. Meanwhile, in the therapeutical effect study of NCTF on high-fat and high-sugar diets combined with STZ-induced T2DM mice, all parameters including RBG, INS, and INSR related to diabetes were significantly improved by NCTF as well as the serum ALT, AST, ALP, CR, MDA, and IL-6 activities. NCTF could significantly increase the expression levels of SOD and PPAR-γ in T2DM. Pathological observation showed that NCTF could improve the damage to pancreatic and liver tissues in T2DM mice. In conclusion, NCTF has better hypoglycaemic and hypolipidemic effects, and its mechanism may be related to its antioxidant, PPAR-γ regulation, and inhibiting inflammatory cytokine expression.

CD226 deficiency attenuates cardiac early pathological remodeling and dysfunction via decreasing inflammatory macrophage proportion and macrophage glycolysis in STZ-induced diabetic mice.

Diabetic cardiomyopathy (DCM) is one of the main complications in type I diabetic patients. Activated macrophage is critical for directing the process of inflammation during the development of DCM. The present study focused on the roles of CD226 on macrophage function during the DCM progression. It has been found that the number of cardiac macrophages in the hearts of streptozocin (STZ)-induced diabetes mice was significantly increased compared with that in non-diabetes mice, and the expression level of CD226on cardiac macrophages in STZ-induced diabetes mice was higher than that in non-diabetes mice. CD226 deficiency attenuated the diabetes-induced cardiac dysfunction and decreased the proportion of CD86+ F4/80+ macrophages in the diabetic hearts. Notably, adoptive transfer of Cd226-/- - bone marrow derived macrophages (BMDMs) alleviated diabetes-induced cardiac dysfunction, which may be due to the attenuated migration capacity of Cd226-/- -BMDM under high glucose stimulation. Furthermore, CD226 deficiency decreased the macrophage glycolysis accompanying by the downregulated hexokinase 2 (HK2) and lactate dehydrogenase A (LDH-A) expression. Taken together, these findings revealed the pathogenic roles of CD226 played in the process of DCM and provided a basis for the treatment of DCM.

RNF20/RNF40 ameliorates streptozotocin-induced type 1 diabetes by activating vitamin D receptors in vivo.

Type 1 diabetes is one of the chronic autoimmune diseases. Its features include the immune-triggered pancreatic beta-cells destruction. Ubiquitin ligases RNF20 and RNF40 have been discovered to participate into beta cells gene expression, insulin secretion, and expression of vitamin D receptors (VDRs). However, no reports about the role of RNF20/RNF40 in type 1 diabetes are known till now. The aim of this study was to clarify the role of RNF20/RNF40 in type 1 diabetes and explore the mechanism. In this study, streptozotocin (STZ)-induced mice type 1 diabetes model was used. The protein expressions of genes were examined through Western blot analysis. Fasting blood glucose was detected through glucose meter. The plasma insulin was tested through the commercial kit. Hematoxylin and eosin staining was utilized to observe pathological changes of pancreatic tissues. Immunofluorescence assay was performed to evaluate the level of insulin. The levels of pro-inflammatory cytokines in serum were assessed by enzyme-linked-immunosorbent serologic assay. The cell apoptosis was measured through terminal deoxynucleotidyl transferase dUTP nick end labelling assay. STZ was used to stimulate mice model for type 1 diabetes. At first, both RNF20 and RNF40 expressions were down-regulated in STZ-mediated type 1 diabetes. Additionally, RNF20/RNF40 improved hyperglycemia in STZ-stimulated mice. Moreover, RNF20/RNF40 relieved pancreatic tissue injury in STZ-induced mice. Further experiments found that RNF20/RNF40 rescued the strengthened inflammation mediated by STZ treatment. The cell apoptosis was enhanced in the pancreatic tissues of STZ-triggered mice, but this effect was weakened by overexpression of RNF20/RNF40. Besides, the VDR expression was positively regulated by RNF20/RNF40. Finally, VDR knockdown reversed improved hyperglycemia, inflammation, and cell apoptosis stimulated by overexpression of RNF20/RNF40. Our findings proved that RNF20/RNF40 activated VDR to relieve type 1 diabetes. This work might highlight the functioning of RNF20/RNF40 in the treatment of type 1 diabetes.

568-P: Study of the Effect of PPARß/δ Activation on Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DC), the leading cause of death among people with diabetes, is definedas the occurrence of myocardial dysfunction in diabetic patients that is not directly attributableto coronary artery disease, hypertension, or valve disease. No specific drugs have yet beenapproved for treating DC and the use of Peroxisome Proliferator-Activated Receptor (PPAR)β/δagonists for the treatment of this disease show promise. Here, we examined as to whethertreatment with a PPARβ/δ agonist can prevent or ameliorate this pathology and as to whetherstreptozotozin (STZ)-induced DC is exacerbated in PPARβ/δ-deficient mice. In the STZ-induced mouse model of DC, an increase in cardiac fibrosis and an impairment inglucose and fatty acid metabolism was observed. Treatment with the PPARβ/δ agonist GW0742partially reduced the STZ-induced fibrosis, inflammation and metabolic disturbances, suggestingthat PPARβ/δ activation might be a potential target to prevent this disease suggesting a closerelation between inflammation and fibrosis in cardiac dysfunction of DC. In addition, we showthat PPARβ/δ suppression exacerbated hyperglycemia-induced DC and that PPARβ/δ activationthrough administration of agonists like GW501516 prevented the induction of some of themolecular mechanisms involved in the development of DC in these cells. Overall, these findingsdemonstrate the implication of PPARβ/δ in DC and suggest that its activation might be aneffective therapeutic tool for preventing or treating DC. Disclosure A.Rostami: None.

Focal adhesion kinase induces cardiac remodeling through NF-κB-mediated inflammatory responses in diabetic cardiomyopathy

BackgroundHyperglycemia-induced chronic inflammation is a crucial risk factor that causes undesirable cardiac alternations in diabetic cardiomyopathy (DCM). Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase that primarily regulates cell adhesion and migration. Based on recent studies, FAK is involved in inflammatory signaling pathway activation in cardiovascular diseases. Here, we evaluated the possibility of FAK as a therapeutic target for DCM. MethodsA small molecular selective FAKinhibitor, PND-1186 (PND), was used to evaluate the effect of FAK on DCM in both high glucose-stimulated cardiomyocytes and streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM) mice. ResultsIncreased FAK phosphorylation was found in the hearts of STZ-induced T1DM mice. PND treatment significantly decreased the expression of inflammatory cytokines and fibrogenic markers in cardiac specimens of diabetic mice. Notably, these reductions were correlated with improved cardiac systolic function. Furthermore, PND suppressed transforming growth factor-β-activated kinase 1 (TAK1) phosphorylation and NF-κB activation in the hearts of diabetic mice. Cardiomyocytes were identified as the main contributor to FAK-mediated cardiac inflammation and the involvement of FAK in cultured primary mouse cardiomyocytes and H9c2 cells was identified. Both FAK inhibition or FAK deficiency prevented hyperglycemia-induced inflammatory and fibrotic responses in cardiomyocytes owing to the inhibition of NF-κB. Herein, FAK activation was revealed to FAK directly binding to TAK1, leading to activation of TAK1 and downstream NF-κB signaling pathway. ConclusionsFAK is a key regulator of diabetes-associated myocardial inflammatory injury by directly targeting to TAK1.

Ginsenoside Rg1 Ameliorates Pancreatic Injuries via the AMPK/mTOR Pathway in vivo and in vitro.

The main propanaxatriol-type saponin found in ginseng (Panax ginseng C. A. Mey), ginsenoside Rg1 (G-Rg1), has bioactivities that include anti-inflammatory, antioxidant, and anti-diabetic properties. This study aimed to investigate the effects of G-Rg1 on streptozotocin (STZ)-induced Type 1 Diabetes mellitus (T1DM) mice and the insulin-secreting cell line in RIN-m5F cells with high-glucose (HG) treatment. The STZ-induced DM mice model was treated with G-Rg1 alone or combined with 3-Methyladenine (3-MA, an autophagy inhibitor)/rapamycin (RAPA, an autophagy activator) for 8 weeks, and levels of glucose and lipid metabolism, histopathological changes, as well as autophagy and apoptosis of relevant markers were estimated. In vitro, the HG-induced RIN-m5F cells were treated with G-Rg1, 3-MA, and Compound C (CC), an AMPK inhibitor, or their combinations to estimate the influences on cell apoptosis, autophagy, and AMPK/mTOR pathway-associated target gene levels. G-Rg1 treatment attenuated glucose and lipid metabolism disorder and pancreatic fibrosis in diabetic mice. In addition, subdued autophagy and p-AMPK protein expression, and enhanced p-mTOR protein expression and apoptosis levels in TIDM mice and HG-induced RIN-m5F cells were ameliorated by G-Rg1 treatment. Furthermore, these anti-apoptosis effects of G-Rg1 were partially abolished by 3-MA and CC. Our findings revealed that G-Rg1 exhibits strong anti-apoptosis ability in pancreatic tissues of type 1 diabetic mice and HG-induced RIN-m5F cells, and the mechanisms involved in activating AMPK and inhibiting mTOR-mediated autophagy, indicating that G-Rg1 may have the therapeutic and preventive potential for treating pancreatic injury in diabetic patients.

Renoprotective Impacts of Inonotus obliquus Ethanol-Ethyl Acetate Extract on Combined Streptozotocin and Unilateral Nephrectomy-Induced Diabetic Nephropathy in Mice.

Diabetes nephropathy (DN) is one of the most common causes of end stage renal disease (ESRD) globally. Medication options to stop or slow the progression of chronic renal disease (CKD) are limited, and patients with DN remain at a high risk of developing renal failure. Inonotus obliquus extracts (IOEs) of Chaga mushroom have been shown to have anti-glycemic, anti-hyperlipidemia, antioxidant, and anti-inflammatory effects against diabetes. In this study, we examined the potential renal protective role of an ethyl acetate layer after water-ethyl acetate separation from Inonotus obliquus ethanol crude extract (EtCE-EA) from Chaga mushrooms in diabetic nephropathy mice after preparation with 1/3 NT + STZ. Our data showed that treatment with EtCE-EA can effectively regulate blood glucose, albumin-creatinine ratio, serum creatinine, and blood urea nitrogen (BUN) levels, and it can improve the renal damage in 1/3 NT + STZ-induced CRF mice with an increase in concentration (100, 300, and 500 mg/kg). In the immunohistochemical staining test, EtCE-EA can effectively reduce the expression of TGF-β and α-SMA after induction according to the increase in the concentration (100 mg/kg, 300 mg/kg), thereby slowing down the degree of kidney damage. Our findings demonstrate that EtCE-EA could provide renal protection in diabetes nephropathy, possibly due to the decreased expression of transforming growth factor-β1 and α-smooth muscle actin.

A 3-miRNA Risk Scoring Signature in Early Diabetic Retinopathy

The aim of our study was to investigate a comprehensive profile of streptozotocin (STZ)-induced early diabetic retinopathy (DR) mice to identify a risk scoring signature based on micorRNAs (miRNAs) for early DR diagnosis. RNA sequencing was performed to obtain the gene expression profile of retinal pigment epithelium (RPE) in early STZ-induced mice. Differentially expressed genes (DEGs) were determined with log2|fold change (FC)| > 1 and p value < 0.05. Functional analysis was carried out based on gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and the protein-protein interaction (PPI) network. We predicted the potential miRNAs via online tools and ROC curves were then conducted. Three potential miRNAs with AUC > 0.7 were explored via public datasets and a formula was further established to evaluate DR severity. In total, 298 DEGs (200 up-regulating and 98 down-regulating) were obtained through RNA sequencing. Hsa-miR-26a-5p, hsa-miR-129-2-3p and hsa-miR-217 were three predicted miRNAs with AUC > 0.7, suggesting their potential to distinguish healthy controls from early DR. The formula of DR severity score = 19.257 - 0.004 × hsa-miR-217 + 5.09 × 10-5 × hsa-miR-26a-5p - 0.003 × hsa-miR-129-2-3p was established based on regression analysis. In the present study, we investigated the candidate genes and molecular mechanisms based on RPE sequencing in early DR mice models. Hsa-miR-26a-5p, hsa-miR-129-2-3p and hsa-miR-217 could work as biomarkers for early DR diagnosis and DR severity prediction, which was beneficial for DR early intervention and treatment.

Dihydromyricetin Attenuates Diabetic Cardiomyopathy by Inhibiting Oxidative Stress, Inflammation and Necroptosis via Sirtuin 3 Activation.

Dihydromyricetin (DHY), the main flavonoid component in Ampelopsis grossedentata, has important benefits for health. The present study aimed to investigate the exact effects and possible mechanisms of DHY on diabetic cardiomyopathy (DCM). Male C57BL/6 mice and sirtuin 3 (SIRT3) knockout (SIRT3-KO) mice were injected with streptozotocin (STZ) to induce a diabetic model. Two weeks later, DHY (250 mg/kg) or carboxymethylcellulose (CMC) were administrated once daily by gavage for twelve weeks. We found that DHY alleviated fasting blood glucose (FBG) and triglyceride (TG) as well as glycosylated hemoglobin (HbA1c) levels; increased fasting insulin (FINS); improved cardiac dysfunction; ameliorated myocardial hypertrophy, fibrosis and injury; suppressed oxidative stress, inflammasome and necroptosis; but improved SIRT3 expression in STZ-induced mice. Neonatal rat cardiomyocytes were pre-treated with DHY (80 μM) with or without high glucose (HG) stimulation. The results showed that DHY attenuated cell damage but improved SIRT3 expression and inhibited oxidative stress, inflammasome and necroptosis in cardiomyocytes with high glucose stimulation. Moreover, the above protective effects of DHY on DCM were unavailable in SIRT3-KO mice, implying a promising medical potential of DHY for DCM treatment. In sum, DHY improved cardiac dysfunction; ameliorated myocardial hypertrophy, fibrosis and injury; and suppressed oxidative stress, inflammation and necroptosis via SIRT3 activation in STZ-induced diabetic mice, suggesting DHY may serve as a candidate for an agent to attenuate diabetic cardiomyopathy.

Streptozotocin-Induced Type 1 and 2 Diabetes Mellitus Mouse Models Show Different Functional, Cellular and Molecular Patterns of Diabetic Cardiomyopathy.

The main cause of morbidity and mortality in diabetes mellitus (DM) is cardiovascular complications. Diabetic cardiomyopathy (DCM) remains incompletely understood. Animal models have been crucial in exploring DCM pathophysiology while identifying potential therapeutic targets. Streptozotocin (STZ) has been widely used to produce experimental models of both type 1 and type 2 DM (T1DM and T2DM). Here, we compared these two models for their effects on cardiac structure, function and transcriptome. Different doses of STZ and diet chows were used to generate T1DM and T2DM in C57BL/6J mice. Normal euglycemic and nonobese sex- and age-matched mice served as controls (CTRL). Immunohistochemistry, RT-PCR and RNA-seq were employed to compare hearts from the three animal groups. STZ-induced T1DM and T2DM affected left ventricular function and myocardial performance differently. T1DM displayed exaggerated apoptotic cardiomyocyte (CM) death and reactive hypertrophy and fibrosis, along with increased cardiac oxidative stress, CM DNA damage and senescence, when compared to T2DM in mice. T1DM and T2DM affected the whole cardiac transcriptome differently. In conclusion, the STZ-induced T1DM and T2DM mouse models showed significant differences in cardiac remodeling, function and the whole transcriptome. These differences could be of key relevance when choosing an animal model to study specific features of DCM.

Soy yoghurts produced with efficient GABA (γ-aminobutyric acid)-producing Lactiplantibacillus plantarum ameliorate hyperglycaemia and re-establish gut microbiota in streptozotocin (STZ)-induced diabetic mice.

Soy yogurt has been gaining popularity as a vegan food produced simply by soymilk fermentation with proper microbial manipulation. It is well known that soy containing rich isoflavones is beneficial for ameliorating hyperglycaemic disorders. Soy fermentation can improve the bioavailability of these precious nutrients. Lactiplantibacillus plantarum is one of the most abundant and frequently isolated species in soymilk manufacturing. Soy yogurts produced with efficient GABA (γ-aminobutyric acid)-producing L. plantarum and the deglycosylating activity of L. plantarum were functionally assessed in a STZ-induced hyperglycaemic mouse model. Hyperglycaemic mice were assigned into groups and treated with daily gavage of either dH2O, soymilk, soy yoghurts produced with high GABA-producing L. plantarum GA30 (LPGA30), low GABA-producing L. plantarum PV30 (LPPV30) or the soy yoghurts fortified with additional 30 mg g-1 GABA counterparts (GA + GABA and PV + GABA groups). Except the dH2O group, all soy yoghurt groups retained body weight with improved glucose homeostasis, glucose tolerance test results and renal tissue integrity, while the soymilk group shows partial benefits. Plasma GABA concentrations in the daily soy yoghurt-supplemented groups (LPGA30 and LPPV30) plateaued at 5 times higher than the average 0.5 μM in dH2O and soymilk groups, and their GABA-fortified soy yoghurt counterparts (GA + GABA and PV + GABA) groups were accountable for the restored plasma insulin levels. Gut microbiome analysis revealed dysbiosis in STZ-induced hyperglycemic mice of the dH2O group with breached out facultative anaerobic Proteobacteria over the normal phyla Firmicutes and Bacteroidetes. Restored gut microbiota with transitionally populated Actinobacteria was demonstrated in the LPGA30 group but not in the LPPV30 group. Soy yoghurts produced with efficient GABA-producing L. plantarum GA30 showed exceptional benefits in modulating gut microbiota with dominant genera of Enterococcus, Lactobacillus and Bifidobacterium, and the presence of some minor beneficial microbial communities including Akkermansia muciniphila, Butyricicoccus pullicaecorum, Corynebacterium spp. and Adlercreutzia spp. Efficient GABA-producing L. plantarum GA30 fermented soymilk to produce soy yoghurts that exhibit profound synergistic protections over rich soy isoflavones to restore pancreatic β-cell functions for insulin production in STZ-induced hyperglycaemic mice. Additionally, the probiotic role of GABA-producing L. plantarum in re-establishing healthy gut microbiota in hyperglycaemic mice implies a possible symbiotic relationship, awaiting further exploration.

In Vivo Hypolipidemic, Hypoglycemic, Antihyperglycemic, and In Vitro Antioxidant Effects of Podocarpus gracilis Leaf Extract and Fractions in Diabetic Mice.

Podocarpus gracilis is an evergreen, dioecious tree found in Ethiopia and other African nations. It can reach a height of 60 meters. Without any scientific validation, ethnobotanical studies conducted in Ethiopia revealed that the Podocarpus gracilis plant's leaf is consumed orally to treat diabetes mellitus. Hence, this study aims to evaluate the in vivo blood glucose level lowering, lipid-lowering, and in vitro-free radical scavenging responses of Podocarpus gracilis leaf extract and fractions on experimental mice induced with diabetes. The in vitro antioxidant activity of PGC (Podocarpus gracilis) leaf extract was assessed by using a diphenyl-2-picrylhydrazyl (DPPH) assay. The oral glucose-loaded, normoglycemic, and streptozotocin- (STZ-) induced diabetic mouse models were employed. In the STZ-induced mice model, the leaf extract and solvent fractions activity on serum lipid and weight were also measured. The extract and fractions were tested at 100, 200, and 400 mg/kg dosages. One-way ANOVA was used to determine the statistical significance of BGL (blood glucose level) changes within and between groups, and Tukey's post hoc multiple comparisons were then performed. In the acute toxicity study of Podocarpus gracilis leaf extract and fractions, there was no evidence of animal mortality at the maximum dose of 2 g/kg during the observation period. The extract-treated group with normoglycemia revealed a significant lowering in BGL at the 4-hour mark of 27.4% (p < 0.001) and 25.2% (p < 0.01) at doses of 200 mg/kg and 400 mg/kg, respectively, compared to that in negative control. In the oral glucose tolerance test (OGTT) model, only 400 mg/kg treated groups at 120 min after exposure showed a BGL reduction of 31.17% which was statistically significant (p < 0.05) in comparison to the negative control. In the single-dose STZ-induced model, eighth-hour BGL measurements from CE 100, CE 200, CE 400, and GLC5 showed drops in BGL of 43.1%, 44.1%, 45%, and 47.3% from baseline fasting BGL values. In the repeated streptozotocin (STZ)-induced model, at all doses of leaf extract and fractions, the fasting BGL was significantly (p < 0.001) reduced. Moreover, the leaf extract and solvent fractions have shown a significant (p < 0.001) reduction of serum lipids such as LDL, TC, and VLDL, and at the same time, it increases HDL at 14 days with body weight gained. In the test for antioxidant activity, the half-maximal inhibitory concentrations (IC50) for leaf extract and the standard medication (ascorbic acid) were 8.2 μg/ml and 3.3 μg/ml, respectively. The IC50 value denotes the concentration of the sample required to scavenge 50% DPPH radicals. The 80% hydromethanolic leaf extract and fractions of Podocarpus gracilis exhibited blood glucose lowering, lipid-lowering activity in normoglycemic, oral glucose tolerance test (OGTT) mode, and STZ-induced diabetic mice with weight gains. There is scientific support for the alleged traditional use as an antidiabetic, lipid-lowering, and antioxidant activity. The results need to be confirmed by future studies.

Hepatoprotective effects of gentisic acid through its anti-oxidant properties in nicotinamide-streptozotocin induced diabetic mice.

Type 2 diabetes mellitus (T2DM) is a common metabolic disorder that causes many complications. Liver failure is one of the complications of T2DM. Oxidative stress plays a major role in the development and progression of T2DM-induced liver injury. Gentisic acid (GA) is a metabolite of aspirin and also a phenolic compound found in natural sources that is a highly effective antioxidant and free radical scavenger. So, in this study, the potential preventive benefits of GA against liver damage induced by T2DM were explored. This study was conducted on 24 adult male mice. T2DM was induced by intraperitoneal injection of a single dose of streptozotocin (at a dose of 65 mg/kg), 15 min after the injection of nicotinamide (at a dose of 120 mg/kg). The grouping was as follows: 1) Normal Control Group; 2) Diabetic Control Group; 3) Positive Control Group: received metformin (150 mg/kg body weight daily) through gavage; 4) Treatment Group: received GA at the dose of 100 mg/kg body weight daily through gavage. Treatments continued for two weeks. Two weeks of GA treatment in diabetic mice reduced fasting blood glucose, improved plasma levels of hepatic enzymes, and increased liver tissue antioxidant capacity. Histopathological examination revealed that GA administration reduced diabetes-induced liver damage. Furthermore, GA treatment led to the down-regulation of Kelch-like ECH-associated protein 1 (Keap1) and up-regulation of nuclear factor E2-related factor 2 (Nrf2). The results of this study showed that GA exerts hepatoprotective effects in STZ-induced T2DM mice.

Hypoglycemic effect of the Phellinus baumii extract with α-glucosidase-inhibited activity and its modulation to gut microbiota in diabetic patients

Phellinus baumii extract (PBE) possesses considerable α-glucosidase-inhibited activity. This study investigated the hypoglycemic effect in vitro and in vivo using a glucose consumption assay in HepG2 cells, intragastric administration for ten weeks in STZ-induced mice, and intestinal flora fermentation in patients with type 2 diabetes to reveal the possible underlying mechanisms. PBE was prepared, including α-glucosidase-inhibited ethanol extract (EE) and aqueous extract (AE). In vitro, PBE promoted glucose consumption and enhanced glycogen content and hexokinase activity but lowered phosphoenolpyruvate carboxylase kinase activity in HepG2 cells. In vivo, PBE treatment significantly reduced the body weight (p < 0.05) and fasting blood glucose levels of diabetic mice (p < 0.01), with the lowest blood glucose level observed in the EE+AE group. Furthermore, the serum insulin levels and insulin resistance index (HOMA) of PBE-treated groups decreased significantly (p < 0.01). Moreover, gene expression levels of the IRS-1/PI3K/AKT pathway were significantly upregulated by PBE treatment (p < 0.01). In vitro fermentation demonstrated that EE significantly inhibited the production of H2S and NH3 in the intestinal flora fermentation model in diabetic patients (p < 0.05). In addition, the ratio of Firmicutes to Bacteroidetes was reduced, the growth of Lactobacillus and Prevotella 9 was promoted, and Pseudomonas aeruginosa was inhibited. This study provides new insights and clues for using PBE as a functional food and clinical drug for glycemic control.

Shen-Qi-Jiang-Tang granule ameliorates diabetic nephropathy via modulating tumor necrosis factor signaling pathway

Ethnopharmacological relevanceShen-Qi-Jiang-Tang granule (SQJTG), a classic traditional Chinese medicine (TCM) prescription, has been widely used in clinical for diabetes, especially type Ⅱ diabetes. Previous anti-diabetic studies stumbled across that SQJTG has a potential kidney protective effect on diabetic nephropathy (DN). However, the protective mechanism of SQJTG on DN still needs to be explored. Aim of the studyThe purpose of the present study was to explore the therapeutic effect of SQJTG on DN through both bioinformatics analysis and in vivo experiments. Methods and materialsThe TCMIP database was used for screening potential compounds and targets of SQJTG, and the GeneCards, OMIM, DrugBank, and TTD databases were used for collecting DN-related genes. Then protein-protein interaction analysis for the common targets of SQJTG and DN was performed by the STRING database. Meanwhile, KEGG and GO were carried out using the Metascape and DAVID databases. In vivo experiments, to testify the potential kidney protective effects of SQJTG, STZ-induced DN mice with different dosages of SQJTG treatment were collected and the renal tissues were detected by H&E, PAS, Masson and TUNEL staining. Immunohistochemistry and immunoblotting were used to assess the proteins’ expressions. Flow cytometry and ELISA assay were used to detect the levels of pro-inflammatory cytokines. ResultsAmong the 338 compounds ascertained by SQJTG, there were 789 related targets as well. Moreover, 1,221 DN-related targets were predicted and 20 core targets were screened by the PPI analyses. According to GO and KEGG pathway analysis, SQJTG may affect DN via the TNF pathway. For the in vivo experiments, renal histomorphological examinations demonstrated that SQJTG treatment significantly ameliorated STZ-induced kidney damage and had a dosage dependence. Meanwhile, mice with DN were found to have dramatic increases in IL-1, TNF-α, IL-6, and IL-12, but markedly decreased after administration of SQJTG. In addition, the protein levels of TNF signaling molecules, like p-P65, p-JNK, and p-p38, showed significantly elevated in kidney tissues of DN mice and attenuated after SQJTG treatment. ConclusionsSQJTG exerts a kidney protective effect in DN mice via modulating TNF signaling pathways, and it has promising applications for the treatment of DN.

Effect of acute and chronic administration of Persia americana (chloroform extract of stem bark) on blood glucose concentration of normoglycaemic and streptozotocin-induced hyperglycaemic mice

The effect of acute and chronic administration of the chloroform extract of the stem bark of P. americana on the blood glucose concentration (BGC) of normoglycaemic and streptozotocin (STZ)-induced hyperglycaemic mice was investigated. Firstly, fifteen (15) young albino mice allocated into three groups of five animals each after a 12 hour overnight fast were treated as follows: group 1 – equi-volume of distilled water, group 11- a single acute dose of 1200 mg/kg IP chloroform extract of P. americana (equivalent to 75% of LD50) and group 111 – 20 mg/kg IP tolbutamide. Immediately after treatment, BGC was measured at 0, ½, 1, 2, 4, and 8 hrs. Secondly another population of 15 animals were shared into 3 groups of 5 animals each. Animals in group 1 were administered equi-volume of distilled water daily, group 11 and group 111 400 mg/kg IP (equivalent to 25% of LD50) extract of P. americana and 10 mg/kg IP of tolbutamide respectively daily for twenty- five days. BGC was measured on days 1, 5, 10, 15,20, 25. Changes in BGC of normoglycaemic and STZ-induced hyperglycaemic mice as a result of acute and chronic administration of extract was compared with values for tolbutamide (positive control) and distilled water (negative control). Results show that in normoglycaemic mice unlike the acute dose of 20 mg/kg IP reference drug tolbutamide, an acute dose of the extract (1200 mg/kg IP) did not significantly lower BGC. In the STZ-induced hyperglycaemic mice however, both the extract and the reference drug tolbutamide significantly lowered the BGC. With chronic administration both the extract and the reference drug significantly lower BGC in STZ-induced hyperglycaemic mice. It can be concluded therefore that acute and chronic administration of the chloroform extract of P. americana does have a hypoglycaemic activity only in STZ-induced hyperglycaemic mice. This may support the use of the stem bark of P. americana in the treatment of Diabetes mellitus.

Single-cell RNA-Seq analysis of diabetic wound macrophages in STZ-induced mice

The crucial role of macrophages in the healing of chronic diabetic wounds is widely known, but previous in vitro classification and marker genes of macrophages may not be fully applicable to cells in the microenvironment of chronic wounds. The heterogeneity of macrophages was studied and classified at the single-cell level in a chronic wound model. We performed single-cell sequencing of CD45 + immune cells within the wound edge and obtained 17 clusters of cells, including 4 clusters of macrophages. One of these clusters is a previously undescribed population of macrophages possessing osteoclast gene expression, for which analysis of differential genes revealed possible functions. We also analysed the differences in gene expression between groups of macrophages in the control and diabetic wound groups at different sampling times. We described the differentiation profile of mononuclear macrophages, which has provided an important reference for the study of immune-related mechanisms in diabetic chronic wounds.Graphical

The Accelerated Progression of Atherosclerosis Correlates with Decreased miR-33a and miR-21 and Increased miR-122 and miR-3064-5p in Circulation and the Liver of ApoE-/- Mice with Streptozocin (STZ)-Induced Type 2 Diabetes.

Atherosclerosis is a major risk factor for type 2 diabetes (T2D) mortality. We aim to investigate the changes in miR-21, miR-122, miR-33a and miR-3064-5p in circulation and the liver of ApoE-/- mice with streptozocin (STZ)-induced T2D. Twenty 5-week-old male ApoE-/- mice were randomly assigned to the control (n = 10) and T2D group (n = 10) and intraperitoneally injected with a citrate buffer and streptozotocin (STZ) (40 mg/kg BW) once a day for three consecutive days. The successfully STZ-induced T2D mice (n = 5) and control mice (n = 5) were then fed with a high-fat diet (HFD) for 34 weeks. Compared to the control mice, ApoE-/- mice with STZ-induced T2D had slower (p < 0.05) growth, increased (p < 0.05) total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), decreased (p < 0.05) high-density lipoprotein cholesterol (HDL-C) in serum, reduced (p < 0.05) TC and sterol regulatory element-binding protein-2 (Srebp-2), elevated (p < 0.05) ATP-binding-cassette-transporter-A1 (Abca1) in the liver, aggravated (p < 0.05) atherosclerotic lesions in the aorta, downregulated (p < 0.05) miR-21 and miR-33a, and upregulated (p < 0.05) miR-122 and miR-3064-5p in serum and the liver. In addition, the aortic lesions showed a positive correlation with miR-122 (r = 1.000, p = 0.001) and a negative correlation with miR-21 (r = −1.000, p = 0.001) in ApoE-/- mice with T2D. In conclusion, T2D-accelerated atherosclerosis correlates with a reduction in miR-21 and miR-33a and an elevation in miR-122 and miR-3064-5p in circulation and the liver of ApoE-/- mice.

Analysis of the Renal Protection and Antioxidative Stress Effects of Panax notoginseng Saponins in Diabetic Nephropathy Mice.

Objective Diabetic nephropathy (DN), a diabetes-induced chronic complication, is the major trigger of end-stage renal disease. As the main active ingredient of Panax notoginseng (PNG), Panax notoginseng saponins (PNS) are crucial in treating renal diseases. This study is aimed at investigating the role played by PNS in renal protection and antioxidative stress (OS) in DN mice. Methods A DN mouse model was constructed, and then low, medium, and high doses of PNS were used to intervene the model group mice. Eight weeks after intervention, the 24 h urine protein (UPro) and urinary albumin (UAlb) were quantitatively examined, and the related blood biochemical indices were measured. HE and PAS staining were performed for pathological changes of renal tissue. ELISA and western blotting were carried out to quantify the levels of OS indexes and inflammatory factors (IFs) in mouse kidney tissues and the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), respectively. Results The weight of DN mice decreased first compared with control animals and then gradually increased after different doses of PNS treatment. Besides, DN mice presented elevated urine volume, UPro, and UAlb, all of which were reversed by PNS intervention. SOD activity and GSH content in renal tissues of the model group mice decreased markedly versus the control group, and MDA, CRP, IL-6, and TGF-β1 contents elevated statistically, while different doses of PNS effectively reduced the OS injury and IFs in mice. Compared with the model group, PNS dose-dependently increased Nrf2 and HO-1 levels in DN mice. Conclusions PNS is protective of HFF + STZ-induced DN mice against kidney tissue damage and can reduce the excretion of UPro and relieve the OS state of mice, possibly by activating Nrf2/HO-1 axis to play an antioxidant and anti-inflammatory role.