Pathway In Diabetic Rats Research Articles

Oridonin ameliorates renal fibrosis in diabetic nephropathy by inhibiting the Wnt/β-catenin signaling pathway

Diabetic nephropathy (DN) is one of the most serious and frequent complications among diabetes patients and presently constitutes vast the cases of end-stage renal disease worldwide. Tubulointerstitial fibrosis is a crucial factor related to the occurrence and progression of DN. Oridonin (Ori) is a diterpenoid derived from rubescens that has diverse pharmacological properties. Our previous study showed that Ori can protect against DN by decreasing the inflammatory response. However, whether Ori can alleviate renal fibrosis in DN remains unknown. Here, we investigated the mechanism through which Ori affects the Wnt/β-catenin signaling pathway in diabetic rats and human proximal tubular epithelial cells (HK-2) exposed to high glucose (HG) levels. Our results revealed that Ori treatment markedly decreased urinary protein excretion levels, improved renal function and alleviated renal fibrosis in diabetic rats. In vitro, HG treatment increased the migration of HK-2 cells while reducing their viability and proliferation rate, and treatment with Ori reversed these changes. Additionally, the knockdown of β-catenin arrested cell migration and reduced the expression levels of Wnt/β-catenin signaling-related molecules (Wnt4, p-GSK3β and β-catenin) and fibrosis-related molecules (α-smooth muscle actin, collagen I and fibronectin), and Ori treatment exerted an effect similar to that observed after the knockdown of β-catenin. Furthermore, the combination of Ori treatment and β-catenin downregulation exerted more pronounced biological effects than treatment alone. These findings may provide the first line of evidence showing that Ori alleviates fibrosis in DN by inhibiting the Wnt/β-catenin signaling pathway and thereby reveal a novel therapeutic avenue for treating tubulointerstitial fibrosis.

The impact of early-life exercise on CREB-signaling pathway and hippocampus neuroplasticity in diabetic adult male rats; the study of developmental model

ABSTRACT Background Childhood exercise enhances brain structure, while diabetes detrimentally affects it. This study examines early-life exercise’s influence on adult diabetic rats’ memory and neuroplasticity. Methods Male Wistar pups were divided into Control, Diabetes, Exercise Training, and Diabetes exercise groups. Diabetes was induced on day 23 with Alloxan (200 mg/kg). A 3-week regimen included aerobic and resistance training thrice weekly. The aerobic intensity was 70%, and resistance varied from 50% to 100% of the maximal carrying capacity (MCC). Following the last training sessions, spatial memory and retrieval tests were performed in infancy, childhood, and emerging adulthood using the Morris Water Maze test (MWM). The hippocampus was excised to measure protein and gene expression of brain-derived neurotrophic factor (BDNF), calmodulin-dependent protein kinase (CAMKII), N-methyl-D-aspartate receptors (NMDAR), and cAMP-response element-binding protein (CREB) by western blotting and reverse transcription–polymerase-chain reaction (RT-PCR) methods. Blood samples were collected during each developmental stage to measure glucose levels, at the study’s conclusion, to assess Interleukin-1β levels using the ELISA method. The Nissel staining assessed dead hippocampal cells in CA1. Results Post-natal exercise improved spatial memory (p < 0.05) and glucose levels (p < 0.05) in diabetic rats during adolescence and emerging adulthood. Despite reduced mRNA expression (NMDAR 40%, BDNF 62%, CREB 43%, CAMKII 66%), diabetic rats, by study end, showed increased BDNF, NMDARR, CAMKII, CREB protein/gene expression (p < 0.05) in emerging adulthood for both training groups. Conclusion Early-life exercise influenced hippocampal BDNF/NMDAR-CAMKII/CREB pathways in a diabetic rat model, highlighting post-natal exercise’s role in neuroplasticity memory enhancement and improved glucose level.

Retracted: Capsaicin Alleviates Vascular Endothelial Dysfunction and Cardiomyopathy via TRPV1/eNOS Pathway in Diabetic Rats.

[This retracts the article DOI: 10.1155/2022/6482363.].

Low-intensity pulsed ultrasound at ST36 improves the gastric motility by TNF-α/IKKβ/NF-κB signaling pathway in diabetic rats.

Low-intensity pulsed ultrasound (LIPUS) can effectively regulate the central and peripheral nervous system. However, whether LIPUS could act on acupuncture points to modulate the activity of peripheral nervous has rarely been studied. Our study aimed to investigate whether LIPUS at ST36 could improve gastric emptying in diabetic gastroparesis rats. Sprague-Dawley male rats were divided into three groups: control group (CON), diabetic gastroparesis group (DM), and diabetic gastroparesis LIPUS treated group (LIPUS). The body weight and blood glucose were recorded every week. Glucose tolerance, gastric emptying rate, and gastric motility were measured before and after treatment. Gastric motility was assessed by ultrasonic examination and Muscle strip experiment. The expression level of c-Kit was assessed by immunohistochemistry staining. Levels of TNF-α, p-NF-κB p-65, NF-κB p-65, and p-IKKβ, IKKβ were measured by western blot. We reported LIPUS at an intensity of 0.88W/cm2 exhibited significant differences in functional recovery of gastric delayed emptying in diabetic rats. Through ultrasound gastric motility functional testing and analysis of gastric antral smooth muscle strips indirectly and directly proved the effectiveness of LIPUS for the recovery of gastric delayed emptying. Pathological analysis and western blot indicated that the mechanism by which LIPUS applied to ST36 improved gastric motility may be partially attributed to the inhibition of the TNF-α/IKKβ/NF-κB signaling pathway, thereby rescuing the damaged interstitial cells of Cajal network. LIPUS at ST36 improved the gastric motility and rescued the damaged networks of interstitial cells of Cajal. LIPUS may have a promising therapeutic potential for diabetic gastroparesis.

Morin hydrate promotes nephrin expression through modulation of Notch1-Snail signalling pathway in diabetic rats

Reduction in nephrin expression is usually observed in patients with diabetic nephropathy, and there is evidence that Notch1/Snail signalling pathway is essential for the expression of nephrin. This study investigated the role of morin hydrate (MH) on Notch1/Snail signalling pathway in the kidney of type-2 diabetic rats (T2D) exposed to diesel exhaust particles (DEP). The male wistar rats (n ​= ​40) were group into 8 groups: Group 1-Control; Group 2-DEP (0.5 ​mg/kg); Group 3-type-2 diabetic rat (T2D); Group 4-T2D ​+ ​DEP (0.5 ​mg/kg); Group 5-DEP (0.5 ​mg/kg) ​+ ​MH (30 ​mg/kg); Group 6-T2D ​+ ​MH (30 ​mg/kg); Group 7-T2D ​+ ​DEP 0.5 ​mg/kg ​+ ​MH 30 ​mg/kg; and Group 8-MH (30 ​mg/kg) only. Type-2 diabetes was induced in the rats through a one-time administration of STZ at 45 ​mg/kg after 14 days treatment with fructose solution at 20% w/v. The type-2 diabetic and non-diabetic rats were exposed to DEP at 0.5 ​mg/kg through nasal instillation every 48 ​h for 14 days. MH (30 ​mg/kg) was given orally every 24 ​h for 15 days. MH is a naturally occurring flavonoid chemical found in a variety of plants, and has been discovered to have a number of biological actions, including antioxidant, anti-inflammatory, and anticancer effects. The effect of MH on kidney function indices and electrolytes, and its modulatory role on Notch1/Snail signalling pathway were determined. In silico studies on binding affinity of MH with some proteins in this pathway was conducted and the electronic behavior of MH was predicted using DFT calculation. The results show that MH oral therapy ameliorates nephrotoxicity and protects the podocytes in T2D rats and T2D rats exposed to DEP. It decreased the serum levels of creatinine, urea and total protein, while also decreasing the levels of renal sodium and potassium ions and bicarbonate. MH increased mRNA expression of nephrin by modulating Notch1/Snail signalling pathway, and these results were supported by the molecular docking studies. This study suggests that MH promote glomerular filtration in T2D exposed to DEP.

MOTS-c repairs myocardial damage by inhibiting the CCN1/ERK1/2/EGR1 pathway in diabetic rats.

Cardiac structure remodeling and dysfunction are common complications of diabetes, often leading to serious cardiovascular events. MOTS-c, a mitochondria-derived peptide, regulates metabolic homeostasis by accelerating glucose uptake and improving insulin sensitivity. Plasma levels of MOTS-c are decreased in patients with diabetes. MOTS-c can improve vascular endothelial function, making it a novel therapeutic target for the cardiovascular complications of diabetes. We investigated the effects of MOTS-c on cardiac structure and function and analyzed transcriptomic characteristics in diabetic rats. Our results indicate that treatment with MOTS-c for 8-week repaired myocardial mitochondrial damage and preserved cardiac systolic and diastolic function. Transcriptomic analysis revealed that MOTS-c altered 47 disease causing genes. Functional enrichment analysis indicated MOTS-c attenuated diabetic heart disease involved apoptosis, immunoregulation, angiogenesis and fatty acid metabolism. Moreover, MOTS-c reduced myocardial apoptosis by downregulating CCN1 genes and thereby inhibiting the activation of ERK1/2 and the expression of its downstream EGR1 gene. Our findings identify potential therapeutic targets for the treatment of T2D and diabetic cardiomyopathy.

MicroRNA-139-5p mediates BMSCs impairment in diabetes by targeting HOXA9/c-Fos.

The properties and functions of BMSCs were altered by the diabetic microenvironment, and its mechanism was not very clear. In recent years, the regulation of the function of BMSCs by microRNA has become a research hotspot, meanwhile, HOX genes also have been focused on and involved in multiple functions of stem cells. In this study, we investigated the role of miR-139-5p in diabetes-induced BMSC impairment. Since HOXA9 may be a target gene of miR-139-5p, we speculated that miR-139-5p/HOXA9 might be involved in regulating the biological characteristics and the function of BMSCs in diabetes. We demonstrated that the miR-139-5p expression was increased in BMSCs derived from STZ-induced diabetic rats. MiR-139-5p mimics were able to inhibit cell proliferation, and migration and promoted senescence and apoptosis in vitro. MiR-139-5p induced the down-regulated expression of HOXA9 and c-Fos in BMSCs derived from normal rats. Moreover, miR-139-5p inhibitors reversed the tendency in diabetic-derived BMSCs. Further, gain-and-loss function experiments indicated that miR-139-5p regulated the functions of BMSCs by targeting HOXA9 and c-Fos. In vivo wound model experiments showed that the downregulation of miR-139-5p further promoted the epithelialization and angiogenesis of diabetic BMSC-mediated skin. In conclusion, induction of miR-139-5p upregulation mediated the impairment of BMSCs through the HOXA9/c-Fos pathway in diabetic rats. Therefore, miR-139-5p/HOXA9 might be an important therapeutic target in treating diabetic BMSCs and diabetic complications in the future.

OEA alleviates apoptosis in diabetic rats with myocardial ischemia/reperfusion injury by regulating the PI3K/Akt signaling pathway through activation of TRPV1.

Reperfusion therapy after myocardial infarction may lead to myocardial injury, which can be complicated and exacerbated by diabetes. The existing therapeutic methods for myocardial ischemia-reperfusion injury (MIRI) in diabetic patients are not ideal. Oleoylethanolamide (OEA) has been found to have protective effects on diabetes and acute cerebral ischemia. This study aimed to determine whether OEA can alleviate MIRI in diabetic rats, and to explore the underlying mechanism. The model of diabetic rats with MIRI was established by blocking the left coronary artery for 30min, followed by restoring blood flow stability for 120min. The myocardial enzyme spectrum, area of MIRI, and expression levels of apoptosis-related proteins were detected. The results showed that OEA pretreatment could reduce myocardial infarction area, protect myocardial tissue structure, and reduce myocardial cell apoptosis in diabetic rats with MIRI. Meanwhile, the levels of creatine kinase (CK)-MB (CK-MB), lactate dehydrogenase (LDH), and malondialdehyde (MDA) were reduced, while superoxide dismutase (SOD) level was elevated. H9C2 cells were treated with high glucose and oxygen-glucose deprivation/reperfusion (OGD/R) to establish an in vitro model. Capsazepine (CPZ), an antagonist of transient receptor potential vanilloid subtype 1 (TRPV1), and LY294002, an inhibitor of PI3K, were used to treat H9C2 cells in vitro. Apoptosis level and the expression levels of apoptosis-related proteins were measured. It was found that OEA activated TRPV1 and the PI3K/Akt signaling pathway, downregulated the expression levels of apoptosis-related proteins (Bcl-2 and cleaved caspase-3), and ameliorated the apoptosis of H9C2 cells treated with high glucose and OGD/R. This study clarified that OEA, as a TRPV1 agonist, could reduce myocardial cell apoptosis by activating the PI3K/Akt signaling pathway in diabetic rats with MIRI. The findings may provide a theoretical basis for administration of OEA as a potential therapeutic agent into diabetic patients with MIRI.

Aerobic exercise improves intestinal mucosal barrier dysfunction through TLR4/MyD88/NF-κB signaling pathway in diabetic rats

This study examined the effects of aerobic exercise on the intestinal mucosal barrier dysfunction in diabetic rats. We established a diabetic rats model consisting of three groups: normal control (NC), diabetes control (DC), and diabetes eight-week aerobic exercise (DE). We measured serum fasting blood glucose (FBG), insulin (INS), diamine oxidase (DAO), D(-)-lactate (D-Lac), lipopolysaccharide (LPS), tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and insulin resistance index (HOMA-IR). Intestinal sections of tissue were stained with H&E and examined using transmission electron microscopy. Expressions of occludin, claudin-1, toll-like receptor-4 (TLR4), myeloid differentiation primary response protein 88 (MyD88), and nuclear factor-κB (NF-κB) in small intestinal mucosa were determined by Western Blot. In comparison to NC, FBG, HOMA-IR, DAO, D-Lac, TNF-α, IL-6, and LPS were increased (P < 0.05) in DC, whereas INS, villus height, crypt depth, and mucosal thickness were decreased (P < 0.05). In comparison to DC, FBG, DAO, D-Lac, TNF-α, and LPS were decreased (P < 0.05) in DE, whereas INS, villus height, crypt depth, and mucosal thickness were increased (P < 0.05). In comparison to NC, occludin and claudin-1 were decreased (P < 0.05) in DC, whereas TLR4, MyD88, and NF-κB were increased (P < 0.05). In comparison to DC, occludin and claudin-1 were increased (P < 0.05) in DE, whereas TLR4, MyD88, and NF-κB were decreased (P < 0.05). In conclusion, eight-week aerobic exercise improved intestinal mucosal barrier dysfunction in diabetic rats, by inhibiting LPS release, TLR4/MyD88/NF-κB signaling pathway, and pro-inflammatory cytokines expression.

Capsaicin Alleviates Vascular Endothelial Dysfunction and Cardiomyopathy via TRPV1/eNOS Pathway in Diabetic Rats.

Background Endothelial dysfunction and cardiomyopathy are considered to be important vascular complications associated with diabetes. This study was designed to investigate whether capsaicin (CAP), a selective TRPV1 agonist, could prevent diabetes-induced endothelial dysfunction and cardiomyopathy. Methods Male Sprague Dawley rats aged 8 weeks were injected intraperitoneally with streptozotocin (STZ, 50 mg/kg) to establish the diabetes model. The diabetic rats were randomly divided into the untreated diabetes group (DM, 10/group) and diabetes plus CAP treatment group (DM+CAP, 10/group); meanwhile, the nondiabetic healthy rats were used as normal controls (10/group). DM+CAP group were treated with CAP by gavage for 8 weeks. The cultured mouse vascular endothelial cells were exposed to different concentrations of glucose in the presence or absence of CAP treatment. The TRPV1 inhibitor capsazepine (CPZ) and eNOS inhibitor L-NAME were used in vivo and in vitro experiment. Results CAP treatment significantly decreased the serum total cholesterol (TC) and total triglyceride (TG) and ameliorated the pathogenesis and fibrosis in the heart, while did not significantly improve plasma glucose level and the body weights of diabetic rats. In addition, CAP enhanced the expression of TRPV1 and eNOS in the heart and normalized the vascular permeability under diabetic state. Similarly, CAP treatment also increased nitric oxide and reduced reactive oxygen species. The same results were observed in cultured mouse vascular endothelial cells by CAP treatment. These beneficial effects of CAP were abolished by either CPZ or L-NAME. Conclusions CAP might protect against hyperglycemia-induced endothelial dysfunction and diabetic cardiomyopathy through TRPV1/eNOS pathway.

Glucose fluctuation promotes cardiomyocyte apoptosis by triggering endoplasmic reticulum (ER) stress signaling pathway in vivo and in vitro

ABSTRACT Glucose fluctuation is more harmful than sustained hyperglycemia, but the effect on cardiomyocyte apoptosis have not yet been clarified. In this study, we aim to identify the effect of glucose fluctuation on cardiomyocyte apoptosis and explore the underlying mechanism. Sprague-Dawley rats were intraperitoneally injected with streptozotocin (STZ) and divided into three groups: controlled diabetic group (C-STZ); uncontrolled diabetic group (U-STZ) and glucose fluctuated diabetic group (GF-STZ). After twelve weeks, echocardiography, Hematoxylin-eosin (HE) staining, and Masson staining were adopted to assess the cardiac function and pathological changes. TUNEL staining was used to detect apoptotic cells. Expressions of apoptosis-related proteins and key molecules in the endoplasmic reticulum (ER) stress pathway were determined via western blots. Further, primary cardiomyocytes incubated in different glucose conditions were treated with the inhibitor of ER stress to explore the causative role of ER stress in glucose fluctuation-induced cardiomyocyte apoptosis. In vivo, we demonstrated that glucose fluctuation promoted cardiomyocyte apoptosis, and were more harmful to cardiomyocytes than sustained hyperglycemia. Moreover, glucose fluctuation significantly triggered ER stress signaling pathway. In vitro, primary cardiomyocyte apoptosis induced by glucose fluctuation and the activation of ER stress were significantly attenuated by 4-PBA, which is an ER stress inhibitor. Above all, glucose fluctuation can promote cardiomyocyte apoptosis through triggering the ER stress signaling pathway in diabetic rats and in primary cardiomyocytes.

Yunpi Heluo decoction reduces ectopic deposition of lipids by regulating the SIRT1-FoxO1 autophagy pathway in diabetic rats

Context Yunpi Heluo (YPHL) decoction is a Chinese herbal formula with particular advantages for treating type 2 diabetes. Yet, its exact mechanism of action is not fully understood. Objective To examine the therapeutic effect of YPHL on ectopic lipid deposition (EDL) in Zucker diabetic fatty (ZDF) rats and the underlying mechanism. Materials and methods The ZDF Rats were randomized into five groups, including model, YPHL (200 mg/kg/d for 10 weeks), SIRT1-overexpression (injected with HBAAV2/9-r-SIRT1-3′-flag-GFP), NC (injected with HBAAV2/9-CMV-GFP as blank control) and control group. Pancreatic β-cells obtained from high-lipid-high-glucose fed rats were treated with YPHL (10 mg/mL) for 48 h. Lipid deposition and autophagosomes were analyzed by transmission electron microscopy. Intracellular H2O2 and ROS concentrations were measured by flow cytometry. SIRT1, FOXO1, LC3 and P62 mRNA and protein levels were analyzed using qRT-PCR and Western blots. Results Compared with the model group, blood glucose levels in YPHL and si-SIRT1 groups were reduced by 19.3% and 27.9%, respectively. In high-lipid-high-glucose cells treated with YPHL, lipid droplets were reduced and decrease in apoptosis rate (38.6%), H2O2 (31.2%) and ROS (44.5%) levels were observed. After YPHL intervention or SIRT1 overexpression, LC3 and p62 expression increased. Protein expression of SIRT1 and LC3 in model, si-SIRT1, si-NC and si-SIRT1 + YPHL groups was lower than those in control group, while FoxO1 expression was increased. All of these protein level alterations were reversed in the si-NC + YPHL group. Discussion and conclusions YPHL reduced EDL by regulating the SIRT1-FoxO1 autophagy pathway in diabetic rats, which could lead to future perspectives for the treatment of diabetes.

Erjing Prescription Ameliorates Insulin Resistance Level with IRS1/PI3K/AKT Signaling Pathways in Diabetic Rats in Vitro and in Vivo

Erjing Prescription Ameliorates Insulin Resistance Level with IRS1/PI3K/AKT Signaling Pathways in Diabetic Rats in Vitro and in Vivo

Silibinin-modified Hydroxyapatite coating promotes the osseointegration of titanium rods by activation SIRT1/SOD2 signaling pathway in diabetic rats

The purpose of this study is to investigate the role of Silibinin (SIL)-modified Hydroxyapatite coating on osseointegration in diabetes in vivo and in vitro and explore the mechanism of osteogenic differentiation of MC3T3-E1. RT-qPCR, Immunofluorescence, and Western blot were used to measure the expression level of oxidative Stress Indicators and osteogenic markers proteins. Moreover, CCK-8 assay was conducted to detect cell viability in hyperglycemia. Alizarin red staining and alkaline phosphatase staining were used to examine osteogenic function and calcium deposits. The diabetic rat model receive titanium rod implantation was set up successfully and Von-Gieson staining was used to examine femoral bone tissue around titanium rod. Our results showed that intracellular oxidative stress in hyperglycemia was overexpressed, while FoxO1, SIRT1, GPX1, and SOD2 were downregulated. SIL suppressed oxidative stress to promote osteogenic differentiation. Additionally, it was confirmed that SIL promoted osteogenic differentiation of MC3T3-E1 and obviously restored the osseointegration ability of diabetic rats. Further study indicated that SIL exerted its beneficial function through activation SIRT1/SOD2 signaling pathway to restore osteoblast function, and improved the osseointegration and stability of titanium rods in vivo. Our research suggested that the SIL-modulated oxidative Stress inhibition is responsible for the activation of the process of osteogenic differentiation through activation SIRT1/SOD2 signaling pathway in hyperglycemia, providing a novel insight into improving prosthetic osseointegration in diabetic patients.Hyperglycemia impaired the activity and function of MC3T3-E1 and inhibits bone formation by up-regulating intracellular ROS levels through inhibition of SIRT1/SOD2 signaling pathway. Local administrator SIL can improve the activity and function of osteoblasts and enhance osseointegration by reducing intracellular ROS through activation of SIRT1/SOD2 signaling pathway in DM rat models.

Palm leaf catechins improved insulin-related pathways in diabetic rats

Catechin-rich oil-palm leaf extract (OPLE) (Elaeis guineensis) was previously demonstrated to possess benefits for diabetes and cardio metabolic health (vasodilation, antioxidant, cardiovascular, anti-hypertensive, anti-inflammatory, hepatoprotective and nephroprotective properties) in animal models. For insights into OPLE anti-diabetic mode-of-action and possible toxicity, the effects of dietary OPLE on insulin-signaling pathways mRNA expressions in the liver, kidney, pancreas, and spleen of normal and diabetic rats were examined. Type-2-Diabetes Mellitus (T2DM) were induced by chronic high-fat diet and streptozotocin (35 mg/kg) intraperitoneal injection. The OPLE (100 mg/kg body weight) were fed daily to normal and T2DM-induced rats. The OPLE suppressed hyperglycaemia and excessive weight gain in the T2DM rats, and appeared harmless to normal rats. The OPLE supplementation significantly (p&lt;0.05) modulated the mRNA expressions of phosphatidylinositol-3 kinase (PIK3R1); insulin signaling receptor (INSR); insulin-receptor substrates 1 and 2; and ectonucleotide pyrophosphatase-1 (ENPP1) especially in the livers of normal rats and the spleen of diabetic rats. Results suggested the OPLE probably help prevent diabetes in healthy mammals and ameliorate the immune functions of diabetic mammals. The OPLE improved the antioxidant defence responses, insulin-pathways mRNA expressions in the normal and diabetic rats; suppressed hyperglycaemia and excessive weight gain in T2DM rodents without observable liver or kidney toxicity at the dose used.

Efonidipine Exerts Cerebroprotective Effect by Down-regulation of TGF-β/SMAD-2-Dependent Signaling Pathway in Diabetic Rats.

Calcium overload and hyperglycemia are risks of stroke onset in diabetics. Our study was designed to elucidate the beneficial role of calcium channel blockers by targeting voltage-gated calcium channels in diabetes-associated cerebrovascular complications. Diabetes was induced using the neonatal streptozotocin rat model. After confirmation of diabetes, middle cerebral artery occlusion (MCAO) was carried out. The pre-treatment with 1 mg/kg/day efonidipine was administered for the period of 4 weeks. After 24 h of ischemic induction surgery, the neurological score was determined, and blood was collected for determination of biochemical parameters. Treatment with efonidipine showed a significant reduction in post-ischemic brain infract volume, brain hemisphere weight difference, neurological score, Na+-K+ ATPase activity, serum CK-MB, and LDH levels in normoglycemic and hyperglycemic MCAO-induced animals. While no significant changes in glucose and lipid levels were observed by treatment, efonidipine significantly decreased the levels of malondialdehyde, acetylcholine esterase, and nitrite levels and increased the levels of antioxidant markers in both normoglycemic and hyperglycemic MCAO animals. TGF-β and VEGF were found to be down-regulated after treatment with efonidipine in gene expression study. In conclusion, the study data supports the cerebroprotective role of efonidipine in diabetic animals possibly through TGF-β/SMAD-2 signaling pathway.

Synergistic cardioptotection by tilianin and syringin in diabetic cardiomyopathy involves interaction of TLR4/NF-κB/NLRP3 and PGC1a/SIRT3 pathways

Diabetic cardiomyopathy (DCM) is a chronic multifactorial complication of type-2 diabetes mellitus, leading to heart failure. A combination of multifaceted therapeutics for the management of DCM is needed. Here, we investigated the combined effect of syringin and tilianin on DCM by evaluating cardiac function, inflammation, oxidative stress, apoptosis and mitochondrial function, and explored the contribution of TLR4/NF-κB/NLRP3 and PGC1α/SIRT3 pathways in diabetic rats and hyperglycemic-H9c2 cells. Syringin and tilianin (50 and 60 mg/kg, i.p, respectively) were administered for eight weeks, individually or in combination, to healthy and type-2 diabetic Sprague-Dawley rats. Myocardial function was recorded using a carotid catheter, mitochondrial and histopathological changes were evaluated by fluorometric and staining methods, cardiac markers and signaling pathways’ proteins expression were measured through ELISA and immunoblotting. In comparison to individual treatments, combination of syringin and tilianin effectively exerted antidiabetic effects and improved cardiac function and DCM markers, reduced NLRP3/IL-6/IL-1β/TNF-α expression, and suppressed diabetes/hyperglycemia‑induced oxidative stress in rats’ heart and H9c2 cells, as demonstrated by decreased 8-isoprostane, and increased superoxide dismutase-2 levels. Mitochondrial membrane depolarization and ROS production were inhibited, and caspase-3 and Bax/Bcl2 expression downregulated by combination therapy. Combined treatment markedly inhibited up-regulation of TLR4, MyD88 and NF-κB in diabetic rats. Finally, inhibition of PGC1α/SIRT3 pathway by 3-TYP in hyperglycemic H9c2-cells reversed the beneficial effects of combination therapy on cardiomyocytes injury and NF-κB/NLRP3/IL-1β expression, without affecting TLR4/MyD88 expression. Syringin plus tilianin synergistically inhibited the diabetes-induced cardiac functional, biochemical and histopathological changes in DCM. Crosstalk between TLR4/NF-κB/NLRP3 and PGC1α/SIRT3/mitochondrial pathways contributed to this protection.

APIGENIN ATTENUATES DIABETIC NEPHROPATHY IN TYPE 1 DIABETIC RATS

Objective: The present study was designed to evaluate the effect of apigenin on progression and development of diabetic nephropathy in diabetic rats. Design and method: Adult male albino Wistar rats were divided into 7 groups: control, diabetic control, apigenin treatment groups (5–20 mg/kg; p.o.), ramipril (2 mg/kg; p.o.) and apigenin per se (20 mg/kg) group. Except control and per se groups, type 1 diabetes in other groups were induced by a single injection of streptozotocin (55 mg/kg; i.p). After confirmation of diabetes (FBG&gt;250 mg/dl), rats were randomly divided into different treatment groups and observed for period of 8 months. Results: After 8 months, STZ resulted in attenuation of renal function (increased BUN and serum creatinine), increased oxidative stress and inflammation (increased cytokines and NF-kappa B) in the diabetic rats. In addition, there was fibrosis (increased transforming growth factor, fibronectin and type IV collagen), apoptosis (increased bax, caspase-3 and decreased bcl-2) and activation of MAPK pathway in diabetic-control group. These results were further supported by histopathological examination, which revealed presence of inflammation, collagen deposition and glomerulosclerosis in renal tissue of diabetic rats. In contrast, pre-treatment with apigenin significantly ameliorated STZ-induced functional and pathological changes in diabetic rats. In addition, it attenuated fibrosis, inflammation and apoptosis and also prevented activation of MAPK pathway in diabetic rats. All these protective effects were comparable to the ramipril treated group. Conclusions: Apigenin ameliorated oxidative stress, inflammation, apoptosis and fibrosis in diabetic rats by attenuation of MAPK pathway and prevented diabetic complication in diabetic rats.

Adiponectin Modified BMSCs Alleviate Heart Fibrosis via Inhibition TGF-beta1/Smad in Diabetic Rats.

Background: Accumulating evidence suggested that bone marrow mesenchymal stem cells (BMSCs) have therapeutic potential for diabetes and heart diseases. However, the effects of BMSC on reducing myocardial fibrosis need to be optimized. This study aimed to investigate the mechanism of adiponectin (APN) modified BMSCs on myocardial fibrosis in diabetic model in vivo and in vitro.Methods: The high-fat diet combined with streptozotocin (STZ) injection were used to induced diabetic rat model. H9c2 cells were cultured under a high glucose medium as in vitro model. The BMSCs were modified by APN plasmid or APN small interfering RNA (siRNA), then transplanted to the diabetic rats by a single tail-vein injection, or co-cultured with H9c2 cells.Results: We demonstrated that diabetic rats showed typical diabetic symptoms, such as decreased cardiac function, accumulation of pathological lesions and collagen expression. However, these impairments were significantly prevented by the APN modified BMSCs treatment while no effects on APN siRNA modified BMSCs treated diabetic rats. Moreover, we confirmed that APN modified BMSCs could attenuate the expression of TGF-beta1/smad to suppress the myocardial fibrosis in the diabetic rats and high glucose induced H9c2 cells.Conclusion: The present results for the first time showed that APN modified BMSCs exerted protection on cardiac fibrosis via inhibiting TGF-beta1/smad signal pathway in diabetic rats. Our findings suggested that APN modified BMSCs might be a novel and optimal therapy for the diabetic cardiomyopathy in future.

Puerarin suppresses the hepatic gluconeogenesis via activation of PI3K/Akt signaling pathway in diabetic rats and HepG2 cells

Pueraria, a Chinese herbal medicine, plays an important role in many classic prescriptions for the treatment of diabetes. Puerarin is the main component of pueraria. The current in vivo and in vitro research mainly focus on exploring the potential mechanism of puerarin in inhibiting hepatic gluconeogenesis. The type 2 diabetic rats were established by a combination of small dosage of streptozotocin (STZ) injection with high-fat diet. After the administration of puerarin 4 weeks, the parameters of the glucose and lipid metabolism were determined. HepG2 cells were treated by palmitic acid (PA) to induce the insulin resistance in vitro model. After the treatment of puerarin, the glucose consumption and cell viability were examined. Then, the protein expression of PI3K, Akt, pAkt, pFOXO1, FOXO1, PEPCK and G6pase in liver tissue and HepG2 cells were evaluated by western blot. RT-PCR was used to measure the content of PEPCK, G6pase mRNA in liver tissue. The results showed that puerarin administration significantly decrease the level of FBG, HbA1C and triglycerides in diabetic rats. Mechanistic research showed that puerarin activating PI3K/Akt is puerarin-mediated beneficial effects and can be reversed by inhibitor of PI3K or Akt. In conclusion, puerarin inhibits hepatic gluconeogenesis by activating PI3K/Akt signaling pathway.