Sex-specific differences in atherosclerosis, thrombospondin-1, and smooth muscle cell differentiation in metabolic syndrome versus non-metabolic syndrome mice.

Introduction: Metabolic syndrome (MetS) amplifies the risks of atherosclerosis. Despite well-known sexual dimorphism in atherosclerosis, underlying mechanisms are poorly understood. Our previous findings highlight a proatherogenic protein, thrombospondin-1 (TSP-1), in hyperglycemia- or hyperleptinemia (mimicking obesity)-induced atherosclerosis. However, the role of TSP-1 in the development of atherosclerosis prompted by co-existing hyperglycemia and obesity, characteristic of MetS, is unknown. The goal of this study was to examine sex-specific differences in lesion progression in a model of combined MetS and atherosclerosis (KKAyApoE) and interrogate how these differences relate to TSP-1 expression. Methods: Male and female KKAy+/-ApoE-/- (with ectopic agouti gene expression) and age-matched non-agouti KKAy-/-ApoE-/- littermates were placed on a standard laboratory diet from 4 to 24 weeks age followed by blood and tissue harvests for biochemical, molecular, and aortic root morphometric studies. Results: Metabolic profiling confirmed MetS phenotype of KKAy+/-ApoE-/-; however, only male genotypes were glucose intolerant with elevated VLDL-cholesterol and VLDL-triglyceride levels. Aortic root morphometry demonstrated profound lipid-filled lesions, increased plaque area, and augmented inflammatory and SMC abundance in MetS vs non-MetS males. This increase in lesion burden was accompanied with elevated TSP-1 and attenuated LMOD-1 (SM contractile marker) and SRF (transcriptional activator of SM differentiation) expression in male MetS aortic vessels. In contrast, while lipid burden, plaque area, and TSP-1 expression increased in MetS and non-MetS female mice, there was no significant difference between these genotypes. Increased collagen content was noted in MetS and non-MetS genotypes, specific to female mice. Measurement of plasma testosterone revealed a link between the atherogenic phenotype and abnormally high or low testosterone levels. To interrogate whether TSP-1 plays a direct role in SMC de-differentiation in MetS, we generated KKAy+/- mice with and without global TSP-1 deletion. Immunoblotting showed increased SM contractile markers in male KKAy+/-TSP-1-/- aortic vessels vs male KKAy+/-TSP-1+/ +. In contrast, TSP-1 deletion had no effect on SM contractile marker expression in female genotypes. Conclusion: Together, the current study implicates a role of plasma testosterone in sex-specific differences in atherosclerosis and TSP-1 expression in MetS vs non-MetS mice. Our data suggest a sex-dependent differential role of TSP-1 on SMC de-differentiation in MetS. Collectively, these findings underscore a fundamental link between TSP-1 and VSMC phenotypic transformation in MetS.

Co-Crystal of Rosiglitazone With Berberine Ameliorates Hyperglycemia and Insulin Resistance Through the PI3K/AKT/TXNIP Pathway In Vivo and In Vitro.

Background: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by insulin resistance and hyperglycemia. This study examined the effect and elucidated the mechanism of improvement of hyperglycemia and insulin resistance by a co-crystal of rosiglitazone with berberine (RB) in high-sugar high-fat diet (HSHFD)-induced diabetic KKAy mice. Methods: Diabetic KKAy mice were randomly divided into seven groups: KKAy model control group (DM control) treated with 3% sodium carboxymethyl cellulose; RB groups, administered daily with RB 0.7 mg/kg (RB-L), 2.11 mg/kg (RB-M), or 6.33 mg/kg (RB-H); positive control groups, administered daily with rosiglitazone 1.04 mg/kg (RSG), berberine 195 mg/kg (BBR), or combination of 1.04 mg/kg RSG and 1.08 mg/kg BBR (MIX). Test compounds were administered orally for 8 weeks. Non-diabetic C57BL/6J mice were used as normal control (NC). Blood glucose, food intake, body weight, glucose-lipid metabolism, and pathological changes in the pancreas and liver were examined. We further evaluated the mechanism of action of RB in C2C12 and HepG2 cells stimulated with high glucose and palmitate. Results: RB treatment improved glucolipid metabolism and insulin resistance in diabetic KKAy mice. RB reduced blood glucose levels, white fat index, plasma triglyceride (TG), low-density lipoprotein (LDL), gastric inhibitory peptide (GIP), and insulin levels, increased the levels of plasma glucagon-like peptide-1 (GLP-1), high-density lipoprotein (HDL), and glycogen content in the liver and muscle; and improved oral glucose tolerance test (OGTT), insulin tolerance test (ITT), and pathological changes in the pancreas and liver of KKAy mice. Moreover, RB upregulated p-PI3K and p-AKT levels and reduced TXNIP expression in KKAy mice and in HepG2 and C2C12 cells. Conclusion: These data indicate that RB ameliorates insulin resistance and metabolic disorders, and the mechanism might be through regulating the PI3K/AKT/TXNIP signaling pathway . Thus, the co-crystal drug RB may be considered as a potential antidiabetic agent for future clinical therapy.

[Effects of Metformin and Sitagliptin on islet cell function in insulin-resistant prediabetic KKay mice].

Objective: To investigate the effects of metformin and sitagliptin on the function of islet ß cells in insulin resistance pre-diabetic KKay mice. Methods: Thirty 6-week-old KKAy mice were randomly divided into two groups: normal diet fed group (NC group, n=10) and high-fat diet fed group (n=20). At 8 weeks, KKAy mice were randomly divided into two groups: metformin intervention group (met group, n=10) and sitagliptin intervention group (SP group, n=10), which were treated by gavage for 8 weeks. Glucose tolerance was measured by oral glucose tolerance test (OGTT), serum insulin level and plasma lipid level were measured by tail blood sampling, and HOMA-ß and HOMA-IR were calculated. The mice were killed after blood collection, and the pancreas of KKAy mice was taken. The ß cell volume of each group was compared by immunofluorescence staining of insulin and glucagon, respectively. The proliferation and apoptosis of ß cell were analyzed by Ki67/INS. The expressions of pancreatic transcription factors PDX-1 and MafA were detected by Western blot. Results: ① The OGTT results indicated that blood glucose of KKAy mice at fast, 30, 60 and 120 min after oral administration of glucose in the Met and SP groups were decreased significantly compared with the NC group, and the area under the blood glucose time curve (AUC) was significantly reduced (P＜0.01, P＜0.01). There was no significant difference between the Met group and the SP group in blood glucose level at 30 and 60 min after oral administration of glucose. Compared with the SP group, the blood glucose of Met group at 120 min was decreased significantly (P＜0.05). There was no significant difference in AUC between the two groups. ② The results of the insulin tolerance test (ITT) indicated that, compared with NC, the fasting blood glucose and the blood glucose at 30, 60 and 90 min after insulin injection in KKAy mice in the Met and SP groups were decreased significantly, and the area under the ITT blood glucose curve (AUC) was increased significantly (P＜0.01), while there was no significant difference between the Met and SP groups. ③ In the NC group, the brightness of the areas of the islet ß cells was low and the edges were scattered. After treated with metformin, the areas and brightness of the ß cells were increased. After treatment with sitagliptin, the area and brightness of the ß cells were increased significantly. In the NC group, the α cells were disordered in the islet distribution and the brightness was large. After the administration of metformin, the α cell area and the brightness were decreased, and distributed to the edge of the islet to a certain extent. After the administration of sitagliptin, there was a significant decrease in the area of the α cells, with a significant decrease in the brightness and distribution at the edge of the islet. ④ Compared with the NC group, the expression levels of pancreatic MafA in the Met group and SP group were increased significantly, which were 1.63 times and 1.58 times, respectively (P＜0.01, P＜0.01). There was no significant difference in the expression of pancreatic PDX-1 between the groups. Conclusion: In pre-diabetes mellitus KKAy mice with insulin resistance, metformin can maintain the function and morphology of pancreatic islets, and sitagliptin may promote the proliferation of islet ßcells, improve the expression level of insulin transcription factor MafA, and prevent the occurrence and development of diabetes.

Pharmacologic inhibition of serotonin htr2b ameliorates hyperglycemia and the altered expression of hepatic FGF21, Sdf2l1, and htr2a in db/db mice and KKAy mice.

Plasma fibroblast growth factor 21 (FGF21) levels and hepatic FGF21, serotonin 2a receptor (htr2a), and stromal cell-derived factor 2 like 1 (Sdf2l1) expression are increased in insulin-resistant C57BL6J mice fed a high-fat diet. Here we show that plasma FGF21 levels and hepatic FGF21, Sdf2l1, and htr2a expression were decreased in 6-week-old db/db mice compared with C57BL6J mice, whereas they were increased in 6-week-old KKAy mice compared with KK mice. Expression of hepatic htr2b was increased in db/db mice and KKAy mice compared with controls. Treatment with the selective htr2b antagonist SB204741 suppressed the hyperglycemia in either db/db mice or KKAy mice. Treatment with SB20471 reversed the decreases in plasma FGF21 levels and hepatic FGF21, Sdf2l1, and htr2a expression in db/db mice, whereas it suppressed the increases in plasma FGF21 levels and hepatic FGF21, Sdf2l1, and htr2a expression in KKAy mice. Moreover, treatment with SB204741 increased plasma FGF21 levels and expression of hepatic FGF21, htr2a, and Sdf2l1 in C57BL6J mice, whereas it decreased plasma FGF21 levels and hepatic FGF21 expression in KK mice. These findings suggest that pharmacologic inhibition of htr2b ameliorates the hyperglycemia and altered expression of hepatic FGF21, Sdf2l1 and htr2a in obese and diabetic db/db and KKAy mice.

Effect of okra polysaccharide on the spermatogenesis of KKAy mice.

In this work, a water-soluble okra polysaccharide (OP-2) was prepared by hot water extraction, and the effects of OP-2 on the spermatogenesis of KKAy mice were investigated. Forty eight KKAy mice with similar initial body weights and lipid and blood glucose levels were randomly divided into four groups, i.e., one control group and three OP-2-treatment groups (treated with 50 mg/kg, 100 mg/kg and 150 mg/kg OP-2, respectively). Oral OP-2 administration increased high-density lipoprotein cholesterol, protein and superoxide dismutase levels in testis, sperm density, sperm movement and rate of normal morphology of KKAy mice and decreased serum total cholesterol, low-density lipoprotein cholesterol, fasting blood glucose and insulin levels and nitrate oxide in testis of KKAy mice. The results indicated that OP-2 can effectively ameliorate the spermatogenesis of KKAy mice and may be used as an adjuvant drug for infertility with diabetes mellitus.

Effects of Agriophyllum squarrosum extracts on glucose metabolism in KKAy mice and the associated underlying mechanisms.

ETHNOPHARMACOLOGICAL RELEVANCE: Agriophyllum squarrosum (L.) Moq. is a traditional Mongol medicine commonly used in the treatment of diabetes. AIM OF THE STUDY: To examine the effects of Agriophyllum squarrosum extract (ASE) on glucose metabolism in type 2 diabetic KKAy mice, and to investigate the mechanisms underlying these effects. MATERIAL AND METHODS: KKAy mice were divided into a model control group (MCG), a low-dose Agriophyllum squarrosum extract group (LASEG), a medium-dose Agriophyllum squarrosum extract group (MASEG), a high-dose Agriophyllum squarrosum extract group (HASEG), and a metformin group (MEG). Syngeneic C57BL/6 mice were used as a normal control group (NCG). Drugs were administered to all mice by gavage for 8 weeks. Random blood glucose levels were measured in the mice at baseline and after 2, 4, and 8 weeks of treatment. Glucose tolerance was measured after 6 weeks of drug administration. After 8 weeks, glycated serum proteins (GSP) and advanced glycation end-products (AGEs) in the serum of all mice were measured. Sections of mouse liver tissues were used for periodic acid-Schiff staining (PAS) and the content of hepatic glycogen was determined. Immunohistochemistry was used to determine the effects of ASE on liver phospho-insulin receptor substrate 2 (P-IRS2) protein expression. Western blotting was used to quantify the protein expression levels of phosphatidylinositol 3-kinase (PI3K), AKT, phospho-AKT (S473) (P-AKT), glycogen synthase kinase 3ß (GSK3ß), and glucose transporters 4 (GLUT4), while PCR was used to quantify the mRNA expression levels of insulin receptor substrate 2 (IRS2), PI3K, AKT, GSK3ß, and GLUT4. RESULTS: ASE treatment decreased random blood glucose levels in type 2 diabetic KKAy mice; increased glucose tolerance; decreased serum GSP and AGEs content; increased glycogen synthesis in liver tissues; upregulated the protein expression levels of PI3K, AKT, GLUT4, and P-IRS2; downregulated the protein expression level of GSK3ß in liver tissues; upregulated the mRNA expression levels of IRS2, PI3K, AKT, and GLUT4; and downregulated the mRNA expression level of GSK3ß in liver tissues. CONCLUSION: ASE treatment may increase glucose metabolism in KKAy mice and improve glucose tolerance. The underlying mechanisms of the beneficial effects of ASE may be associated with the increase of glycogen synthesis, the inhibition of AGEs production, the upregulation of IRS2, PI3K, AKT, and GLUT4 protein and mRNA expression, and the downregulation of GSK3ß protein and mRNA expression.

Panax notoginseng saponins alleviate skeletal muscle insulin resistance by regulating the IRS1-PI3K-AKT signaling pathway and GLUT4 expression.

Panax notoginseng saponins (PNS) are a commonly used traditional medicine to treat diabetes in China. Recent studies have confirmed their anti-diabetic effects, but the underlying mechanisms have remained unclear. The present study was designed to explore whether PNS decrease hyperglycemia by improving insulin sensitivity in skeletal muscle and to elucidate the molecular mechanisms. The anti-diabetic effects of PNS were analyzed in a skeletal myoblast cell line, C2C12, and in high fat diet-induced diabetic KKAy mice. C2C12 cells were treated with PNS (50, 100, and 200 µg·L-1 ) and examined for glucose uptake, cell viability and expression of components of the phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway. KKAy mice were intraperitoneally injected with PNS (200 mg·kg-1 ) for 6 weeks. Body weight, blood glucose, serum insulin, serum lipid, glucose and insulin tolerance were measured to evaluate the anti-diabetic effects of PNS. Pathological changes, apoptosis and the PI3K-AKT signaling pathway were analyzed in KKAy skeletal muscle. PNS significantly increased insulin-induced glucose uptake, but did not affect the cell viability of C2C12 cells. In addition, PNS reduced blood glucose and serum insulin levels and improved glucose tolerance and insulin tolerance of KKAy mice. Pathological changes and apoptosis of skeletal muscle were relieved by PNS treatment. Moreover, PNS treatment enhanced expression of mRNA encoding IRS1 and GLUT4, as well as the protein expression of phosphorylated (p) -insulin receptor substrate 1 (IRS1), p-PI3K, p-AKT and glucose transporter type 4 (GLUT4) in C2C12 and KKAy mouse muscle. Collectively, these data indicate that PNS reduces hyperglycemia and insulin resistance through up-regulating GLUT4 expression and the IRS1-PI3K-AKT signaling pathway. Furthermore, PNS alleviated diabetes skeletal muscle pathological damage. Thus, our data suggest that PNS may be promising anti-diabetic compounds.

Effect of a novel nonsteroidal selective mineralocorticoid receptor antagonist, esaxerenone (CS-3150), on blood pressure and renal injury in high salt-treated type 2 diabetic mice.

Although beneficial antihypertensive and antialbuminuric effects of steroidal mineralocorticoid receptor (MR) antagonists have been shown, the use of these drugs has been clinically limited in diabetic kidney disease (DKD) because of the high incidence of side effects. Here, we aimed to examine the effect of a novel nonsteroidal selective mineralocorticoid receptor antagonist, esaxerenone, on blood pressure and renal injury in high salt-treated type 2 diabetic KK-Ay mice, a model of human hypertensive DKD. KK-Ay mice were treated with a normal salt diet (NS: 0.3% NaCl, n = 5), high salt diet (HS: 4% NaCl, n = 8), HS + esaxerenone (1 mg/kg/day, p.o., n = 8), or HS + spironolactone, a steroidal non-selective MR antagonist (20 mg/kg/day, p.o., n = 7) for 8 weeks. Renal tissue oxidative stress was evaluated by dihydroethidium florescence intensity. HS-treated diabetic KK-Ay mice showed higher blood pressure and severe albuminuria, glomerular injury, tubulointerstitial fibrosis, renal inflammation, and oxidative stress than NS-treated diabetic KK-Ay mice. Treatment with esaxerenone or spironolactone decreased blood pressure to a similar extent in HS-treated KK-Ay mice. Conversely, esaxerenone elicited a greater attenuation of albuminuria, glomerular injury, tubulointerstitial fibrosis, and renal inflammation than spironolactone, which were associated with reduction in renal oxidative stress. These data indicate for the first time that a nonsteroidal MR antagonist elicits renoprotective effects in DKD mice.

Renal Protective Effect of Tangshiping Capsule on Diabetic Nephropathy Kkay Mice and Its Effect on Wnt/β-catenin Signal Transduction Pathway / 中国实验方剂学杂志

Objective:To investigate the renal protective effect of Tangshenping capsule (Tangshenping) on diabetic nephropathy (DN) KKAy mice and its effect on Wnt/β-catenin signaling pathway. Method:Sixty female Sprague-Dawley KKAy mice aged 10 weeks old were induced with KKAy rat feed for 10 weeks. The DN animal model was successfully determined with blood glucose (>16.7 mmol·L-1) and 24 hour urine protein (>0.4 mg). The model mice were randomly divided into a model group, an irbesartan group, and low, medium and high-dose Tangshenping group, with 10 female C57BL/6J mice as a control group. The treatment groups were given the corresponding drugs by gavage. The normal group and the model group were given an equal volume of deionized water by gavage. The intragastric dose was 0.01 mL·g-1 body weight coefficient once a day. The general conditions of the mice were observed, the body mass was weighed every 4 weeks, and 24 h urine protein was quantified. At the 26th week, the blood was collected from eyeballs, and the mice were put to death. The quality of the kidneys, serum blood urea nitrogen (BUN), serum creatinine (SCr), triglyceride (TG), malondialdehyde (MDA), nitric oxide (NO) and superoxide dismutase (SOD) content were measured. In situ hybridization and immunohistochemistry were used to detect the expressions of Wnt4, glycogen synthase kinase 3β(GSK3β) and β-catenin in kidney tissues. Result:Compared with model group, body mass, kidney mass/body mass, and 24 h urine protein were significantly lower in high-dose Tangshenping group (PPPβ and β-catenin were decreased (PConclusion:Tangshenping may inhibit the activation of Wnt/β-catenin signaling pathway, reverse the transdifferentiation of renal tubular epithelial cells in DN KKAy mice, delay the progression of renal interstitial fibrosis, and then exert renal protection.

Xiao Ke Qing improves glycometabolism and ameliorates insulin resistance by regulating the PI3K/Akt pathway in KKAy mice.

Xiao Ke Qing (XKQ) granule has been clinically used to treat type 2 diabetes mellitus (T2DM) for 10 years in Chinese traditional medication. However, its mechanisms against hyperglycemia remain poorly understood. This study aims to investigate XKQ mechanisms on diabetes and diabetic liver disease by using the KKAy mice model. Our results indicate that XKQ can significantly reduce food and water intake. XKQ treatment also remarkably decreases both the fasting blood glucose and blood glucose in the oral glucose tolerance test. Additionally, XKQ can significantly decrease the serum alanine aminotransferase level and liver index and can alleviate the fat degeneration in liver tissues. Moreover, XKQ can ameliorate insulin resistance and upregulate the expression of IRS-1, PI3K (p85), p-Akt, and GLUT4 in the skeletal muscle of KKAy mice. XKQ is an effective drug for T2DM by ameliorating insulin resistance and regulating the PI3K/Akt signaling pathway in the skeletal muscle.

Protective effects of IFN-γ on the kidney of type- 2 diabetic KKAy mice.

BACKGROUND: Development of novel therapeutic strategies that specifically target diabetic kidney disease (DKD) is urgently needed. METHODS: Male KKAy mice were divided randomly into three equal groups - KK, KI, and KF; Male C57BL/6 mice were the control group. All KKAy mice were fed a high-fat diet. From the 16th week, the KI group was given IFN-γ, and the KF group was assigned to be treated with fludarabine. C57BL/6 mice were always fed a normal mouse diet. Every 4 weeks, body weight, random blood sugar, urine albumin and urea of all mice were measured. At the 20th week, all mice were killed, renal tissue was obtained to observe the pathological manifestations and extract proteins, and transforming growth factor- beta1 (TGF-ß1), collagen IV and Janus kinase 2/signal transducers and activators of transcription 1 (JAK2/STAT1) pathway proteins were measured by western blot. RESULTS: The present study showed that all KKAy mice appeared obese and hyperglycaemic from 12 weeks old and exhibited an increased urine albumin-to-creatinine ratio (ACR) from 16 weeks old. At the 20th week, compared to the KK group, the KI group showed lower ACR, more overexpression of P-STAT1 and less expression of TGF-ß1 and collagen IV proteins in renal tissue. The KI group mice showed less accumulation of glomerular mesangial matrix than those in the KK group. CONCLUSIONS: Our results indicate that IFN-γ might activate STAT1 to suppress the overexpression of TGF-ß1 and collagen IV proteins and attenuate the excessive accumulation of mesangial matrix under DKD conditions in KKAy mice.

The effects of hypoglycemia and weight loss of total lignans from Fructus Arctii in KKAy mice and its mechanisms of the activity.

Fructus Arctii (great burdock achene) is the dried ripe fruit of Arctium lappa L. (family Asteraceae) and is included in the Chinese pharmacopoeia. It has been reported that the clinical use of Fructus Arctii resulted in a satisfactory hypoglycemic effect in diabetic patients. This study aimed to investigate antidiabetic activity and mechanism of total lignans from Fructus Arctii (TLFA) in KKAy mice, a spontaneous Type 2 diabetic rodent model that exhibits marked obesity. In this study, KKAy mice were gavaged once daily with solvents (0.5% sodium carboxymethyl cellulose), TLFA (250 and 125 mg/kg), or metformin (200 mg/kg) for 11 weeks, and C57BL/6J mice treated with saline solution (0.9%, w/v) were used as normal control. The results indicate that TLFA has dual effects of hypoglycemia and weight loss, and administration of TLFA in KKAy mice could decrease fasting blood glucose, glycated hemoglobin, and body weight; improve oral glucose tolerance; increase high density lipoprotein cholesterol; and decrease triglycerides and free fatty acid in mice serum. Its efficacy may associate with multiple mechanisms of action such as stimulation of insulin secretion, activation of phosphatidylinositol 3-kinase/protein kinase B, and adenosine-monophosphate-activated protein kinase signaling pathway, decreasing leptin.

Xiao Ke Qing improves glycometabolism and ameliorates insulin resistance by regulating the PI3K/Akt pathway in KKAy mice / 医学前沿

Xiao Ke Qing (XKQ) granule has been clinically used to treat type 2 diabetes mellitus (T2DM) for 10 years in Chinese traditional medication. However, its mechanisms against hyperglycemia remain poorly understood. This study aims to investigate XKQ mechanisms on diabetes and diabetic liver disease by using the KKAy mice model. Our results indicate that XKQ can significantly reduce food and water intake. XKQ treatment also remarkably decreases both the fasting blood glucose and blood glucose in the oral glucose tolerance test. Additionally, XKQ can significantly decrease the serum alanine aminotransferase level and liver index and can alleviate the fat degeneration in liver tissues. Moreover, XKQ can ameliorate insulin resistance and upregulate the expression of IRS-1, PI3K (p85), p-Akt, and GLUT4 in the skeletal muscle of KKAy mice. XKQ is an effective drug for T2DM by ameliorating insulin resistance and regulating the PI3K/Akt signaling pathway in the skeletal muscle.

Mixture of five herbal extracts ameliorates pioglitazone-induced aggravation of hepatic steatosis via activating the adiponectin receptor 2/AMP-activated protein kinase signal pathway in diabetic KKAy mice.

OBJECTIVE: To assess the effect of a mixture of five herbal extracts (FT-5) on insulin resistance, glucose/lipid metabolism, hepatic steatosis, and to investigate whether the combination of FT-5 and pioglitazone would provide a robust effect on diabetes treatment, while may minimize undesirable side-effects of pioglitazone in diabetic Ay gene (KKAy) mice. METHODS: Seven-week-old KKAy mice were randomly divided into five groups: control (CON) group, FT-5 (2.0 g/kg) group, pioglitazone (20 mg/kg) (PIO) group, pioglitazone (20 mg/kg) + FT-5 (2.0 g/kg) (P + F) group. Age-matched C57BL/6J mice were used as the control group. After seven weeks of continuous intragastric administration of medication, the glucose metabolism, insulin sensitivity and lipid metabolism of KKAy mice were evaluated by assessing the fasting blood glucose (FBG), oral glucose tolerance test (OGTT), fasting serum insulin (FINS), insulin tolerance test (ITT), homeostasis model of assessment-insulin resistance index (HOMA-IR), total cholesterol (TC), total triglycerides (TG), and free fatty acids (FFA) in plasma and liver. Plasma and hepatic adiponectin were measured via enzyme-linked immunosorbent assays. Genes related to adipogenesis and lipolysis in white adipose tissues (WAT) and liver were examined by real-time polymerase chain reaction. Lipid metabolism-related protein expression in the liver of KKAy mice were detected by Western blotting. RESULTS: PIO treatment remarkably improved insulin resistance. However, it also showed substantial side effects. FT-5 group exhibited no significant decrease in serum glucose. However, it reduced fasting plasma TG levels and improved hepatic steatosis of KKAy mice. P + F group showed improved insulin resistance and similar body weight gain, as compared with control group. The mRNA expression of genes related to fatty acid oxidation was markedly up-regulated in the liver of P + F group. Pioglitazone administration markedly decreased the phosphorylation levels of AMPK, as compared with all other groups. Besides, even though plasma adiponectin increased in PIO, FT-5, P + F group, adipoR2 gene expression significantly decreased in the liver of PIO group. CONCLUSION: FT-5 decreased plasma TG and alleviated aggravating hepatic steatosis induced by pioglitazone in KKAy mice. FT-5's mechanism might be associated with its ability to activate the AdipoR2/AMPK pathway.

Effects of astragalus injection combined with puerarin injection on process of endoplasmic reticulum stress through PERK pathway in dabe-tic nephropathy mice / 中国病理生理杂志

AIM: To investigate the effects of astragalus injection combined with puerarin injection on endo-plasmic reticulum stress through PERK pathway in diabetic nephropathy mice .METHODS: Male KKAy mice were ran-domly divided into model group ( injected with normal saline ) and treatment group ( injected with astragalus and puerarin ) . The male C57BL/6J mice served as normal group .The mice were sacrificed 4 weeks after treatments for observing morpho-logical changes under electron microscope .The renal tissues were collected to determine the expression of protein kinase R-like endoplasmic reticulum kinase ( PERK ) , eukaryotic initiation factor 2α( eIF2α) and glucose-regulated protein 78 (GRP78) at mRNA and protein levels by real-time PCR and Western blot.RESULTS: Under electron microscope, the renal tubular epithelial cells in model group and treatment group showed the swelling of the nucleus , endoplasmic reticulum and mitochondria .The results of real-time PCR and Western blot showed that the expression of PERK , eIF2αand GRP78 at mRNA and protein levels in model group was higher than that in normal group (P<0.05), while that in treatment group was lower than that in model group .CONCLUSION: Astragalus injection combined with puerarin injection reduces the mRNA and protein expression of PERK , eIF2αand GRP78, thus inhibiting the endoplasmic reticulum stress in type 2 dia-betic mice to protect the kidney function .

Renoprotective Effect of Tang-Shen-Ning and Its Influence on Notch/Snail1 Pathway in Diabetic Nephropathy KKAy Mice / 世界科学技术-中医药现代化

This paper was aimed to study the renal protective effect of Tang-Shen-Ning (TSN) on diabetic nephropathy (DN) KKAy mice by inhibiting the Notch/snail1 signal transduction pathway.A total of 30 KKAy mice,which were fed with mice-dedicated food for 10 weeks and with the blood glucose over 16.7 mmol· L-1,24-hour urinary albumin larger than 0.4 mg,were made into the DN model.The DN mice were randomly divided into the model group,irbesartan group and TSN group according to their blood glucose and weight.Intragastric administration of medication was given.A total of 10 female C57BL/6J mice were selected as the control group.The general condition,body weight and 24-hour urinary protein quantitation were detected.After 16-week intervention,mice were sacrificed.Levels of blood glucose,blood urea nitrogen (BUN) and serum creatinine (Scr) were detected.HE and Mallory staining were applied to renal tissues.In situ hybridization (ISH) and western blotting were used to detect the Notch/snail 1 pathway,α-SMA,E-Cadherin protein and mRNA expression in renal tissues.Statistical analysis was made by SPSS20.0 software.The results showed that compared with the model group,the rats' general conditions were improved;body weight and 24-hour urinary protein quantitation were significantly decreased (P＜0.01);contents of BUN and Scr were reduced (P＜0.01,P＜0.05).The pathological staining showed significantly reduction on renal interstitial fibrosis.The Notch/snail1 pathway,protein and mRNA expression of α-SMA were significant reduced with statistical significance (P＜0.01);protein and mRNA expression of E-Cad protein were significant increased with statistical significance (P＜0.01).It was concluded that TSN can protect the renal function of DN,delay the disease progression of DN,and inhibit epithelial-mesenchymal transdifferentiation (EMT) of renal tubular epithelial cells and renal interstitial fibrosis.Furthermore,the inhibition on EMT may be through the regulation of the Notch/snail1 pathway.

Renoprotective Effects of Tang-Shen-Ping on RhoA/ROCK Signaling Pathway in Diabetic Kidney Disease KKAy Mice / 世界科学技术-中医药现代化

This study was aimed to explore the renoprotective effects of Tang-Shen-Ping (TSP) on RhoA/ROCK signaling pathway in KKAy mice with diabetic kidney disease (DKD).A total of 60 female 10-week SPF degree KKAy mice,which were fed with KK special food for 10 weeks,were made into DKD model.Mice were randomly divided in the model group,irbesartan group,low-,medium-and high-dose TSP group (0.525 g· kg-1,1.05 g· kg-1,and 2.1 g· kg-1).Ten female C57BL/6J mice were used as the normal control group.Mice of each group were intragastrically administered with corresponding medicine,respectively,while mice of the control group and the model group were given deionized water of the equal volume.The body weight was measured and the 24-hour urine protein quantification was detected every 4 weeks.At the end of the 26th week,all mice were sacrificed and the biochemical indicators,such as fasting blood glucose (FBG),serum blood urea nitrogen (BUN),serum creatinine (Scr),and triglyceride (TG) were measured.HE staining,Mallory staining and PAS staining were used to observe the pathological morphology of kidney tissues.Immunohistochemistry (IHC) and in situ hybridization (ISH) were used in the detection of transforming growth factor-β1 (TGF-β1),Ras homolog gene family member A (RhoA),Rho-associated coiled-coil-containing protein kinase 1 (ROCK1),α-smooth muscle actin (α-SMA),E-Cadherin (E-Cad) mRNA and protein expression.The results showed that compared with the model group,there were significant differences on body weight,the ratio of kidney weight to body weight,and urinary protein in the middle-and high-dose TSP group (P ＜ 0.01);the renal pathological damage was obviously decreased;contents of FBG,BUN,Scr and TG decreased (P ＜ 0.01);mRNA and protein expression of E-Cadherin increased;mRNA and protein expression of TGF-β1,RhoA,ROCK1 and α-SMA decreased with significant difference in the middle-and high-dosc TSP group (P ＜ 0.01).It was concluded that the renoprotective effects and epithelial-mesenchymal transdifferentiation (EMT) of renal tubular epithelial cells of TSP on DKD KKAy mice may be related to the regulation of RhoA/ROCK signaling pathway.

A novel formula Sang-Tong-Jian improves glycometabolism and ameliorates insulin resistance by activating PI3K/AKT pathway in type 2 diabetic KKAy mice.

AIMS: Sang-Tong-Jian (STJ), a novel formula composed of flavonoids and alkaloids derived from mulberry leaf, has been found to reduce blood glucose levels in rats with type 2 diabetes mellitus (T2DM) in our previous studies. However, the precise mechanisms remain unknown. Insulin resistance is the main characteristic of T2DM, which may be due to impairment of the PI3K/AKT signaling pathway. In this study, we investigated the effects of STJ on glycometabolism and insulin resistance in KKAy mice. METHODS: A total of 50 KKAy male mice were randomly divided into five groups: model, metformin at 260mg/kg, and STJ at 105, 210 and 420mg/kg. C57BL/6J mice were used as the control group. Random blood glucose levels in KKAy mice were determined every 10days after treatments. At the 10th and 13th week, oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were conducted after a 12h overnight fast, respectively. After 13-week treatments, glycosylated hemoglobin (GHb) and serum insulin were measured using a colorimetric method and ELISA kits. Liver glycogen and muscle glycogen levels were analyzed using a colorimetric method. The morphology of pancreas, liver, skeletal muscle and epididymal fat were visualized by haematoxylin and eosin staining. The gene level of GLUT2 (liver) and GLUT4 (skeletal muscle, epididymal fat) were detected by real-time PCR. The proteins of GLUT2, GLUT4, IRS1, PI3K, AKT and their phosphorylation were assayed by Western blot analyses. RESULTS: STJ significantly decreased the random blood glucose and GHb levels, and increased liver and muscle glycogen levels. The results of OGTT and ITT and measurement of serum insulin indicated that STJ ameliorated insulin resistance in KKAy mice. STJ treatments also ameliorated the histopathological alterations in pancreas, liver, skeletal muscle and epididymal fat in KKAy mice. Furthermore, STJ upregulated the gene and protein expression of GLUT2 (liver) and GLUT4 (skeletal muscle, epididymal fat). Meanwhile, GLUT4 translocation and phosphorylation of IRS1, p85-PI3K and AKT were significantly increased by STJ treatments. CONCLUSIONS: Our results indicated that STJ ameliorated glycometabolism and insulin resistance in KKAy mice, which might be due to activation of PI3K/AKT pathway.

Effect of astragalus injection on renal tubular epithelial transdifferentiation in type 2 diabetic mice.

BACKGROUND: Astragalus injection is used by practitioners of traditional Chinese medicine to treat diabetic nephropathy (DN). The current study was conducted to determine the effect of astragalus on tubular epithelial transdifferentiation during the progression of DN in KKAy mice, as well as to investigate the molecular mechanism underlying this effect. METHODS: Diabetic, 14-week-old, male KKAy mice were randomly divided into a model group and an astragalus treatment group, while age-matched male C57BL/6 J mice were selected as controls. The treatment group received daily intraperitoneal injections of astragalus (0.03 mL/10 g per day), while the model group received injections of an equal volume of saline. Mice were euthanized after 24 weeks. Serum samples were obtained from the animals in each group for blood glucose measurement. Kidney tissue samples were used for morphometric studies. The mRNA and protein expression levels of transforming growth factor beta 1 (TGF-ß1), transforming growth factor beta receptor 1 (TGFß-R1), alpha smooth muscle actin (α-SMA), and E-cadherin were evaluated using real-time polymerase chain reaction (PCR) and western blotting. RESULTS: Astragalus significantly reduced blood glucose levels; inhibited morphological changes in the kidneys of KKAy mice; reduced mRNA and protein expression levels of TGF-ß1, TGFß-R1, and α-SMA; and increased E-cadherin expression. CONCLUSIONS: Tubular epithelial transdifferentiation plays an important role in the development of DN in diabetic mice. Administration of astragalus likely prevents or mitigates DN by suppressing tubular epithelial transdifferentiation, protecting KKAy mice from renal damage.

Antidiabetic effects of flavonoids from Sophora flavescens EtOAc extract in type 2 diabetic KK-ay mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Bitter and cold Chinese medicines have been long used for the treatment for diabetes mellitus (DM) for thousands of years in China. The roots of Sophora flavescens Ait., one of bitter and cold Chinese medicines commonly used to remove lung heat have been used to counteract DM and exerted good clinical effects for diabetic patients in some folk hospitals in Fujian province, PR China. However, the corresponding active principles and antidiabetic mechanism of this Traditional Chinese Medicine remain unclear. Therefore, in this study, we aim at chemical profiling of the active principles, validating the potential antidiabetic effects of the active EtOAc extract (SF-EtOAc) in vitro and in vivo, and elucidating its probable antidiabetic mechanism as well as evaluating its acute oral toxicity. MATERIALS AND METHODS: An off-line semi-preparative LC-NMR and LC-UV-ESI MS protocol was developed to determine the chemical principles of the active EtOAc extract rapidly and unambiguously. The effect of SF-EtOAc on the glucose transporter type 4 (GLUT4) translocation in L6 myotubes was examined. T2DM KK-Ay mice were induced by high-fat diet. SF-EtOAc was orally administration at the dose of 30, 60 and 120 mg/kg/d, for 21 days. Metformin was used as positive control. Body weight, plasma glucose, oral glucose tolerance test, serum insulin and blood-lipid indexes were measured. Phosphorylation of the AMP-activated protein kinase (AMPK) expression in liver was measured. RESULTS: We found that SF-EtOAc significantly improved oral glucose tolerance, increased serum high density lipoprotein cholesterol (HDL-C) and reduced body weight, blood glucose levels and other related blood-lipid indexes. Mechanistically, SF-EtOAc elevated phosphorylation of AMP-activated protein kinase (AMPK) and stimulated membrane translocation of GLUT4. Moreover, it was unveiled that oral median lethal dose (LD50) of SF-EtOAc was more than 7500 mg/kg, suggesting that SF-EtOAc was practically non-toxic for mice. CONCLUSIONS: SF-EtOAc improves glucose tolerance, reduces hyperglycemia and resumes insulin levels, at least in part, by activating GLUT4 translocation which may be modulated by AMPK pathway. According to the results of the present study, SF-EtOAc possesses a potent antidiabetic activity and could be used as a safe remedy for the treatment of diabetes.