The association between thyroid dysfunction (TD) and diabetic kidney disease (DKD) in type 2 diabetes mellitus (T2DM).

BACKGROUND: Epidemiological studies have identified an association between thyroid dysfunction (TD) and various kidney diseases. In this study, the prevalence of TD in type 2 diabetic mellitus (T2DM) patients with diabetic kidney disease (DKD) was evaluated to analyse the potential association between TD and DKD in T2DM patients. METHODOLOGY: A total of 2108 T2DM patients from Anhui Provincial Hospital were recruited in this study. Demographic and clinical characteristics were collected from 834 T2DM patients with DKD and 1274 T2DM patients without DKD (non-DKD). All patients were stratified into a number of groups based on UACR (urine albumin-to-creatinine ratio) or eGFR (estimated glomerular filtration rate): (a) A1: normoalbuminuria (<30), A2: microalbuminuria (30-300) and A3: macroalbuminuria (>300); (b) F1: normal filtration (60-139), F2: hyper filtration (≥140) and F3: low filtration (<60). RESULTS: Significant differences were observed between the non-DKD and DKD groups (P < .05) in age, sex ratio, duration, systolic blood pressure, total cholesterol, low density lipoprotein cholesterol, serum creatinine, blood urea nitrogen, free triiodothyronine (FT3), free thyroxine (FT4) and sensitive thyrotropin hormone (sTSH). The macroalbuminuira and low filtration groups had the lowest levels of FT3 and FT4 and the highest level of sTSH, compared with all other groups (P < .0167). The prevalence of subclinical hypothyroidism in the DKD group was significantly higher than that in the non-DKD group (χ2  = 13.92, P < .01). Logistic regression analysis showed that hypothyroidism was associated with increased UACR or reduced eGFR in T2DM patients. Compared with controls, T2DM patients with hypothyroidism exhibited a higher UACR and urinary excretion of transferrin, as well as a lower excretion of urinary Tamm-Horsfall protein (THP) (P < .0167). CONCLUSION: Subclinical hypothyroidism is more prevalent in T2DM patients with DKD than in T2DM patients without DKD. Hypothyroidism is associated with albuminuria and decreased eGFR in T2DM patients.

Alleviation of podocyte injury: the possible pathway implicated in anti-inflammation of alpha-lipoic acid in type 2 diabetics.

BACKGROUND AND AIMS: The objective of this study is to observe the effect of alpha-lipoic acid (ALA) on Pod injury by anti-inflammation and explore its possible renal protective mechanism. METHODS: A total of 36 cases with type 2 diabetes with microalbuminuria and fasting plasma glucose (FPG) levels less than 9 mmol/L and glycated hemoglobin A1c (HbA1c) ≤9.0 % were recruited to be treated with ALA (600 mg, daily) for 6 months (group DA). Another 30 healthy individuals were chosen as normal controls (group NC). The levels of serum creatinine (Cr), FPG, and HbA1c were detected; blood pressure was recorded; and early morning urine samples (corrected for urinary Cr) were collected for the examination of urinary monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-ß1 (TGF-ß1), podocalyxin (PCX), nephrin, albumin and Cr in group NC and group DA at the baseline and the sixth month. RESULTS: The excretions of urinary MCP-1, TGF-ß1, PCX, nephrin and albumin to Cr ratio (abbreviated as UMCR, UTCR, UPCR, UNCR and UACR respectively) were significantly increased in group DA compared with group NC (all P < 0.01), and after 6-month treatment, all indexes mentioned above decreased markedly (P < 0.05), while FPG and HbA1c had no obvious changes. Additionally, there was a positive correlation between UMCR, UTCR with UPCR, UNCR and UACR, respectively (all P < 0.01). CONCLUSIONS: Anti-inflammation of ALA in vivo and local kidney is implicated in the protection of glomerular Pod injury in patients with type 2 diabetes.

Application of non-mydriatic fundus photography-assisted telemedicine in diabetic retinopathy screening.

BACKGROUND: Early screening and accurate staging of diabetic retinopathy (DR) can reduce blindness risk in type 2 diabetes patients. DR's complex pathogenesis involves many factors, making ophthalmologist screening alone insufficient for prevention and treatment. Often, endocrinologists are the first to see diabetic patients and thus should screen for retinopathy for early intervention. AIM: To explore the efficacy of non-mydriatic fundus photography (NMFP)-enhanced telemedicine in assessing DR and its various stages. METHODS: This retrospective study incorporated findings from an analysis of 93 diabetic patients, examining both NMFP-assisted telemedicine and fundus fluorescein angiography (FFA). It focused on assessing the concordance in DR detection between these two methodologies. Additionally, receiver operating characteristic (ROC) curves were generated to determine the optimal sensitivity and specificity of NMFP-assisted telemedicine, using FFA outcomes as the standard benchmark. RESULTS: In the context of DR diagnosis and staging, the kappa coefficients for NMFP-assisted telemedicine and FFA were recorded at 0.775 and 0.689 respectively, indicating substantial intermethod agreement. Moreover, the NMFP-assisted telemedicine's predictive accuracy for positive FFA outcomes, as denoted by the area under the ROC curve, was remarkably high at 0.955, within a confidence interval of 0.914 to 0.995 and a statistically significant P-value of less than 0.001. This predictive model exhibited a specificity of 100%, a sensitivity of 90.9%, and a Youden index of 0.909. CONCLUSION: NMFP-assisted telemedicine represents a pragmatic, objective, and precise modality for fundus examination, particularly applicable in the context of endocrinology inpatient care and primary healthcare settings for diabetic patients. Its implementation in these scenarios is of paramount significance, enhancing the clinical accuracy in the diagnosis and therapeutic management of DR. This methodology not only streamlines patient evaluation but also contributes substantially to the optimization of clinical outcomes in DR management.

High doses of salicylate and aspirin are inhibitory on acid-sensing ion channels and protective against acidosis-induced neuronal injury in the rat cortical neuron.

Aspirin and its main metabolite salicylate are widely used to relieve pain, treat inflammatory diseases, and prevent ischemic stroke. Multiple pathways are responsible for the therapeutic actions exerted by these drugs. One of the pathways is targeting neuronal receptors/ion channels in the central nervous system. Correspondingly, increasing evidence has implicated acid-sensing ion channels (ASICs) in the processes of the diseases that are medicated by aspirin and salicylate. We therefore employed whole-cell patch-clamp recordings to examine the effects of salicylate as well as aspirin on ASICs in cultured cortical neurons of the rat. We recorded rapid and reversible inhibition of ASIC current by millimolar concentrations of aspirin and salicylate and found that salicylate reduced acidosis-induced membrane depolarization. These data suggest that ASICs in the cortex are molecular targets of high doses of aspirin and salicylate. In addition, the results from lactate dehydrogenase release measurement showed that high doses of aspirin and salicylate protected the cortical neuron from acidosis-induced neuronal injury. These findings may contribute to a better understanding of the therapeutic mechanisms of aspirin and salicylate actions in the brain and provide new evidence on aspirin and salicylate used as neuroprotective agents in the treatment of ischemic stroke.

Comprehensive Network Analysis Reveals the Targets and Potential Multitarget Drugs of Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) is a metabolic disease with increasing prevalence and mortality year by year. The purpose of this study was to explore new therapeutic targets and candidate drugs for multitargets by single-cell RNA expression profile analysis, network pharmacology, and molecular docking. Single-cell RNA expression profiling of islet ß cell samples between T2DM patients and nondiabetic controls was conducted to identify important subpopulations and the marker genes. The potential therapeutic targets of T2DM were identified by the overlap analysis of insulin-related genes and diabetes-related genes, the construction of protein-protein interaction network, and the molecular complex detection (MCODE) algorithm. The network distance method was employed to determine the potential drugs of the target. Molecular docking and molecular dynamic simulations were carried out using AutoDock Vina and Gromacs2019, respectively. Eleven cell clusters were identified by single-cell RNA sequencing (scRNA-seq) data, and three of them (C2, C8, and C10) showed significant differences between T2DM samples and normal samples. Eight genes from differential cell clusters were found from differential cell clusters to be associated with insulin activity and T2DM. The MCODE algorithm built six key subnetworks, with five of them correlating with inflammatory pathways and immune cell infiltration. Importantly, CCR5 was a gene within the key subnetworks and was differentially expressed between normal samples and T2DM samples, with the highest area under the ROC curve (AUC) of 82.5% for the diagnosis model. A total of 49 CCR5-related genes were screened, and DB05494 was identified as the most potential drug with the shortest distance to CCR5-related genes. Molecular docking illustrated that DB05494 stably bound with CCR5 (-8.0 kcal/mol) through multiple hydrogen bonds (LYS26, TYR37, TYR89, CYS178, and GLN280) and hydrophobic bonds (TRP86, PHE112, ILE198, TRP248, and TYR251). This study identified CCR5 as a potential therapeutic target and screened DB05494 as a potential drug for T2DM treatment.

The Effects of RBP4 and Vitamin D on the Proliferation and Migration of Vascular Smooth Muscle Cells via the JAK2/STAT3 Signaling Pathway.

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are one of the main causes of the development of diabetic atherosclerotic process. The aim of our study was to assess the role of RBP4 in the proliferation and migration of VSMCs and the inhibitory effect of vitamin D on the mechanisms. In an in vivo experiment, rats were randomly classified into 6 groups: the control group, diabetic rats, diabetic atherosclerotic rats (diabetic rats intraperitoneally injected with RBP4), diabetic atherosclerotic rats treated with 0.075 µg kg-1 d-1 vitamin D, 0.15 µg kg-1 d-1 vitamin D and 0.3 µg kg-1 d-1 vitamin D. We found that the levels of JAK2, STAT3, cylinD1, and Bcl-2 were increased in diabetic atherosclerotic rats, and these increases were improved after vitamin D supplementation. Furthermore, to investigate the underlying molecular mechanisms, cells were cultured with glucose in the presence of RBP4 and the absence of RBP4, respectively, and vitamin D of different concentrations and different intervention times was simultaneously adopted. The proliferation and migration of VSMCs was enhanced and the levels of JAK2, STAT3, cyclinD1, and Bcl-2 were increased in the cells transfected with RBP4 overexpression plasmid. Moreover, vitamin D supplementation was detected to lower the expressions of JAK2, STAT3, cyclinD1, and Bcl-2 and inhibit the abnormal proliferation of VSMCs caused by the RBP4/JAK2/STAT3 signaling pathway. RBP4 can promote the proliferation and migration of VSMCs and contributes to the development of diabetic macroangiopathy via regulating the JAK2/STAT3 signaling pathway. This mechanism of RBP4 can be inhibited by vitamin D supplementation.

Elevated retinol binding protein 4 levels are associated with atherosclerosis in diabetic rats via JAK2/STAT3 signaling pathway.

BACKGROUND: Atherosclerosis is a major cause of mortality worldwide and is driven by multiple risk factors, including diabetes, which results in an increased atherosclerotic burden, but the precise mechanisms for the occurrence and development of diabetic atherosclerosis have not been fully elucidated. AIM: To summarize the potential role of retinol binding protein 4 (RBP4) in the pathogenesis of diabetic atherosclerosis, particularly in relation to the RBP4-Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway. METHODS: Male Wistar rats were randomly divided into three groups, including a control group (NC group), diabetic rat group (DM group), and diabetic atherosclerotic rat group (DA group). The contents of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), fasting insulin (FINS), fasting plasma glucose, and hemoglobin A1c (HbA1c) were measured. Moreover, the adipose and serum levels of RBP4, along with the expression levels of JAK2, phosphorylated JAK2 (p-JAK2), STAT3, phosphorylated STAT3 (p-STAT3), B-cell lymphoma-2 (Bcl-2), and Cyclin D1 in aortic tissues were also measured. Besides, homeostasis model assessment of insulin resistance (HOMA-IR) and atherogenic indexes (AI) were calculated. RESULTS: Compared with the NC and DM groups, the levels LDL-c, TG, TC, FINS, HOMA-IR, RBP4, and AI were upregulated, whereas that of HDL-c was downregulated in the DA group (P < 0.05); the mRNA levels of JAK2, STAT3, Cyclin D1, and Bcl-2 in the DA group were significantly increased compared with the NC group and the DM group; P-JAK2, p-JAK2/JAK2 ratio, p-STAT3, p-STAT3/STAT3 ratio, Cyclin D1, and Bcl-2 at protein levels were significantly upregulated in the DA group compared with the NC group and DM group. In addition, as shown by Pearson analysis, serum RBP4 had a positive correlation with TG, TC, LDL-c, FINS, HbA1C, p-JAK2, p-STAT3, Bcl-2, Cyclin D1, AI, and HOMA-IR but a negative correlation with HDL-c. In addition, multivariable logistic regression analysis showed that serum RBP4, p-JAK2, p-STAT3, and LDL-c were predictors of the presence of diabetic atherosclerosis. CONCLUSION: RBP4 could be involved in the initiation or progression of diabetic atherosclerosis by regulating the JAK2/STAT3 signaling pathway.

17α-hydroxylase/17,20 carbon chain lyase deficiency caused by p.Tyr329fs homozygous mutation: Three case reports.

BACKGROUND: p.Tyr329fs is a cytochrome P450c17 mutation among Chinese individuals. However, data on 17-α-hydroxylase deficiency caused by cytochrome P450c17 p.Tyr329fs homozygous mutation are lacking. This paper is a case report of three patients homozygous for p.Tyr329fs who were diagnosed with 17-α-hydroxylase deficiency between 2005 and 2019. CASE SUMMARY: Case 1 presented with hypertension, hypokalemia, sexual infantilism and delayed bone age. The patient had a 46, XY karyotype, was homozygous for p.Tyr329fs and was recently treated with dexamethasone 0.375 mg qn. Case 2 presented with hypokalemia, sexual infantilism, osteoporosis and delayed bone age. The patient had a 46, XY karyotype, was homozygous for p.Tyr329fs and was treated with dexamethasone 0.75 mg qn at the last follow-up. Serum potassium and blood pressure could be maintained within normal range for cases 1 and 2. Case 3 presented with amenorrhea, sexual infantilism, osteopenia and delayed bone age. The patient had a 46, XX karyotype, was homozygous for p.Tyr329fs and was treated with dexamethasone 0.75 mg qn and progynova 1 mg qd. Outpatient follow-up revealed an adrenocorticotropic hormone (8 AM) of < 5.00 pg/mL. CONCLUSION: The homozygous p.Tyr329fs mutation usually manifests as a combined deficiency, and definitive diagnosis depends primarily on genetic testing.

Hydrochloride pioglitazone decreases urinary cytokines excretion in type 2 diabetes.

OBJECTIVE: To observe the effects of hydrochloride pioglitazone on urinary cytokine excretion in type 2 diabetes and to explore its possible reno-protective mechanisms. DESIGN: Subjects and Methods. Ninety-eight patients with type 2 diabetes and a fasting blood glucose (FBG) levels between 7.0 and 13.0 mm and glycated haemoglobin A1c (HbA1c) ≥ 7.0% were assigned randomly to receive either the pioglitazone (DP group) or a sulphonylurea (DS group). Another 49 healthy individuals were chosen as normal controls (group NC). At the start of the study and after 12 weeks of treatment, urinary cytokines including monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-ß1 (TGF-ß1) and vascular endothelial growth factor were measured and were expressed as a ratio of urinary creatinine excretion. Urinary albumin/creatinine ratio, FBG and HbA1c were determined at the same time. RESULTS: The excretion of each urinary cytokine, corrected for urinary creatinine, was significantly increased in both groups of patients with diabetes, compared with normal controls, and after a 12-week treatment were significantly decreased by both therapies but the effect of pioglitazone was statistically greater than with sulphonylureas. Urinary albumin/UCr and both systolic and diastolic blood pressure were decreased significantly by pioglitazone (P < 0.01 or P < 0.05) but not by sulphonylurea treatment (P < 0.05), while there was no significant difference in FBG or HbA1c between two groups. There was a positive correlation between the excretion of cytokines and urinary albumin /UCr (all P < 0.01). CONCLUSIONS: This study indicates that pioglitazone reduces urinary albumin excretion by a mechanism that is at least partly independent of blood sugar control. The correlation of urinary albumin excretion with improvement in urinary cytokines suggests that this reno-protective effect of piogliazone in diabetes may be related to local reduction in cytokine activity within the kidney.

Hydrochloride pioglitazone decreases urinary TGF-beta1 excretion in type 2 diabetics.

BACKGROUND: Thiazolidinediones (TZDs) exert a number of direct reno-protection beyond its hypoglycaemic effect in type 2 diabetics, which may be partly related to its anti-fibrosis and anti- inflammatory action. MATERIALS AND METHODS: A total of 98 type 2 diabetics with fasting blood glucose (FBG) between 7.0 and 13.0 mmol L(-1) and glycated haemoglobin A1c (HbA1c) > or = 7.0% were randomly assigned to add pioglitazone (group DP) or sulfonylurea (group DS) for 12 weeks. FBG, HbA1c, serum creatinine (SCr) and blood urea nitrogen (BUN), and urinary TGF-beta1, albumin (UALB) and creatinine (UCr) were determined at the basal and the 12th week. RESULTS: Fasting blood glucose, HbA1c and urinary TGF-beta1/UCr ratio (UTCR) were obviously decreased in both groups after 12 weeks treatment; UALB/UCr ratio (UACR) decreased obviously in group DP (P < 0.01), while slightly in group DS. UACR and UTCR in group DP were significantly lower than those in group DS after treatment, while FBG and HbA1c had no statistical differences between the two groups. In addition, UTCR had positive correlation with UACR (r = 0.367, P < 0.01). CONCLUSIONS: Pioglitazone decreases urinary TGF-beta1 excretion in type 2 diabetics, which may be partly contributed to its direct reno-protection.

Effect of short-term intensive insulin therapy on α-cell function in patients with newly diagnosed type 2 diabetes.

The effect of intensive insulin therapy on hyperglucagonemia in newly diagnosed type 2 diabetes (T2DM), and its associations with ß-cell function, has not been elucidated. This study assessed the effect of 12 weeks of intensive insulin therapy on hyperglucagonemia in newly diagnosed T2DM and its associations with ß-cell function, with reference to the effects of 12 weeks of oral hypoglycemic agents (OHAs).One hundred eight patients with newly diagnosed T2DM were enrolled from January 2015 to December 2015. The patients were randomly divided to receive, for 12 weeks, either intensive insulin therapy or OHAs. Meal tolerance tests were conducted at baseline before treatment (0 week), at 12 weeks (end of treatment), and 12 months after the initiation of treatment. The levels of glucagon, proinsulin, C-peptide (CP), and blood glucose were measured at timepoints 0, 30, and 120 minutes during the meal tolerance test.Intensive insulin treatment was associated with a decrease in glucagon levels (at 0, 30, and 120 minutes) and proinsulin/CP, and an increase in the insulin-secretion index ΔCP30/ΔG30 and ΔCP120/ΔG120, at 12 weeks and 12 months during the follow-up, compared with the corresponding effects of OHAs. Intensive insulin therapy could reduce but failed to normalize glucagon levels at 12 weeks. There were no correlations between the change of percentages in total area under the curve of glucagon and other glycemic parameters (proinsulin/CP; ΔCP30/ΔG30; or ΔCP120/ΔG120). Patients who received intensive insulin therapy were more likely to achieve their target glycemic goal and remission, compared with those who received OHAs.Short-term intensive insulin therapy facilitates the improvement of both ß-cell and α-cell function in newly diagnosed T2DM mellitus. Decline of ß-cell secretion and concomitant α-cell dysfunction may both be involved in the pathogenesis of T2DM.

Rosiglitazone protects diabetic rats against kidney injury through the suppression of renal matrix metalloproteinase-9 expression.

In this study, the effects of rosiglitazone on renal matrix metalloproteinase-9 (MMP-9) expression and its possible renoprotective mechanisms were investigated in streptozotocin-induced diabetic rats. We examined the urinary excretion rates of albumin (ALB), retinal-binding protein (RBP) and MMP-9 in control healthy rats (group C, n = 8), untreated diabetic rats (group D, n = 8) and diabetic rats treated with rosiglitazone (5mg/kg/day) (group R, n = 8) at eighth week. The renal tissue of diabetic rats was obtained for observing renal pathological changes by electron microscope and examining the expression of renal MMP-9 mRNA by RT-PCR. Our results showed that urinary excretion rates of MMP-9. ALB and RBP were significantly increased concurrently with the expression of renal MMP-9mRNA in group D compared with those of group C. Rosiglitazone significantly reduced urinary excretion rates of ALB, RBP and MMP-9 as well as the expression of renal MMP-9 mRNA. In addition, urinary excretion rate of MMP-9 showed positive relationship with urinary excretion rates of ALB and RBP. In conclusion, rosiglitazone definitely protects diabetic rats against renal injury, which may be partly associated with decreasing expression of renal MMP-9 mRNA and urinary MMP-9 production.

Efficacy and Safety of Dulaglutide Versus Insulin Glargine in Chinese T2DM Patients: A Subgroup Analysis of a Randomized Trial (AWARD-CHN2).

INTRODUCTION: To evaluate efficacy and safety data of dulaglutide in Chinese patients with type 2 diabetes mellitus (T2DM) who had inadequate glycemic control with 1-2 oral antihyperglycemic medications (OAMs). METHODS: This is a subgroup analysis of a phase 3, open-label, randomized, parallel-arm, 52-week study in Chinese patients aged ≥ 18 years with T2DM who had inadequate glycemic control with OAMs (glycated hemoglobin [HbA1c] ≥ 7.0% and ≤ 11.0%). The primary endpoint was assessment of the noninferiority of dulaglutide 1.5 mg as measured by change in HbA1c, compared with insulin glargine (glargine), using a 0.4% noninferiority margin at week 26. RESULTS: A total of 607 patients from China were randomized 1:1:1 to once-weekly dulaglutide 1.5 or 0.75 mg or once-daily glargine. At week 26, the least squares mean (LSM) change from baseline in HbA1c was greater with dulaglutide 1.5 mg (- 1.67%) and dulaglutide 0.75 mg (- 1.31%) compared with glargine (- 1.11%). The LSM (95% confidence interval) for the difference of dulaglutide 1.5 mg and 0.75 mg vs glargine was - 0.56% (- 0.75 to - 0.37) and - 0.20% (- 0.39 to - 0.01), respectively. Both doses of dulaglutide were noninferior and superior to glargine at 26 weeks and 52 weeks (two-sided P value < 0.05). The mean body weight decreased (P < 0.001) and total hypoglycemia rates were lower (P < 0.05) in the dulaglutide groups compared with the glargine group. Gastrointestinal adverse events (AEs) were the most frequently reported AEs in dulaglutide groups. CONCLUSION: Both doses of dulaglutide are efficacious and tolerable in Chinese patients with T2DM who had inadequate glycemic control on OAMs. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT01648582. FUNDING: Eli Lilly and Company.

Involvement of RBP4 in Diabetic Atherosclerosis and the Role of Vitamin D Intervention.

The purposes of this study were to evaluate the expression of retinol-binding protein 4 (RBP4) in diabetic rats with atherosclerosis and to investigate the role of vitamin D intervention. Male Wistar rats were randomly divided into 4 groups, including the control group (NC), the diabetic rats (DM1), the untreated diabetic atherosclerosis rats (DM2), and the vitamin D-treated diabetic atherosclerosis rats (DM3). The levels of serum and adipose RBP4, fasting insulin (FINS), fasting plasma glucose (FPG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), 25-hydroxyvitamin D [25(OH)D], C-reactive protein (CRP), and systolic blood pressure (SBP) were measured. Homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment ß-cell function index (HOMA-ß), and atherogenic indexes (AI) were calculated. Compared with group NC, the levels of RBP4, TG, LDL-c, FPG, FINS, CRP, AI1, AI2, SBP, and HOMA-IR increased, while the levels of HDL-c, 25(OH)D, and HOMA-ß decreased in groups DM1 and DM2. After 8 weeks of vitamin D supplementation in group DM3, the levels of 25(OH)D and HOMA-ß increased and the levels of LDL-c, TC, HOMA-IR, FINS, CRP, RBP4, AI1, AI2, and SBP decreased significantly when compared with group DM2 (P < 0.05); Pearson analysis showed that serum RBP4 was positively correlated with TG, FINS, HOMA-IR, SBP, CRP, and AI and negatively correlated with 25(OH)D. In addition, multivariable logistic regression analysis showed that serum RBP4, SBP, and HDL-c were predictors for the presence of diabetic atherosclerosis. These findings suggested that RBP4 could involve in the improvement of diabetic atherosclerosis; vitamin D had the ability to decrease the level of RBP4 and eventually played an important role in preventing atherosclerosis in diabetes.

Relationship between serum 25-hydroxyvitamin D and lower extremity arterial disease in type 2 diabetes mellitus patients and the analysis of the intervention of vitamin D.

The aim of this study was to explore the relationship between serum 25-hydroxyvitamin D [25(OH)D] concentrations and lower extremity arterial disease (LEAD) in type 2 diabetes mellitus (T2DM) patients and to investigate the intervention effect of vitamin D. 145 subjects were assigned to a control group (Group NC), T2DM group (Group DM1), and T2DM complicated with LEAD group (Group DM2); then Group DM2 were randomly divided into Group DM3 who received oral hypoglycemic agents and Group DM4 who received oral hypoglycemic drugs and vitamin D3 therapy. Compared to Group NC, 25(OH)D was significantly lower in Group DM2 and marginally lower in Group DM1. In contrast to baseline and Group DM3, 25(OH)D rose while low density lipoprotein (LDL), retinol binding protein 4 (RBP4), and HbA1c significantly lowered in Group DM4. Statistical analysis revealed that 25(OH)D had a negative correlation with RBP4, duration, HbA1c, homeostasis model assessment for insulin resistance (HOMA-IR), and fasting plasma glucose (FPG). LDL, systolic blood pressure (SBP), FPG, and smoking were risk factors of LEAD while high density lipoprotein (HDL) and 25(OH)D were protective ones. Therefore, we deduced that low level of 25(OH)D is significantly associated with the occurrence of T2DM complicated with LEAD.

Metformin alleviates high glucose-mediated oxidative stress in rat glomerular mesangial cells by modulation of p38 mitogen-activated protein kinase expression in vitro.

The aim of the current study was to investigate the effects and mechanism of metformin in oxidative stress and p38 mitogen-activated protein kinase (p38MAPK) expression in rat glomerular mesangial cells (MCs) cultured in a high glucose medium. Rat glomerular MCs (HBZY-1) were cultured in complete medium and divided into the following five groups: Normal control (NC), high glucose (HG), metformin-treated, SB203580-treated (SB) and N-acetylcysteine-treated (NAC). The production of intracellular reactive oxygen species (ROS) in rat glomerular MCs was measured using flow cytometry. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in the supernatant was detected using colorimetric analysis and an ELISA, respectively. p22phox mRNA levels in rat glomerular MCs were determined using reverse transcription-quantitative polymerase chain reaction. The levels of p22phox protein and phosphorylated p38 mitogen-activated protein kinase (p-p38MAPK) protein in rat glomerular MCs were determined by western blot analysis. Compared with the NC group, the activity of SOD in the supernatant was significantly reduced, whereas the levels of MDA in the supernatant, intracellular p22phox mRNA and protein, p-p38MAPK protein in addition to ROS production in rat glomerular MCs were significantly increased in the HG group (P<0.05). When metformin was added to the high glucose medium, the activity of SOD in supernatant fluid was increased significantly, whereas a significant reduction (P<0.05) was observed in the levels of MDA in the supernatant, intracellular p22phox mRNA and protein, p-p38MAPK protein in addition to ROS production in rat glomerular MCs. These results were similar to those obtained when SB203580 or N-acetylcysteine was added to the high glucose medium (P<0.05). In conclusion, metformin was suggested to alleviate high glucose-induced oxidative stress and p-p38MAPK protein expression in rat glomerular MCs, which may contribute to its reno­protective abilities in diabetes.

Pioglitazone Inhibits the Expressions of p22(phox) and p47(phox) in Rat Mesangial Cells In Vitro.

Aim. The purpose of this study was to investigate the effects of pioglitazone on oxidative stress and the expressions of p22(phox) and p47(phox), subunits of NADPH oxidase, in mesangial cells (MCs). Method. Rat mesangial cells were cultured and randomly divided into normal glucose (NG) group, high glucose (HG) group, and pioglitazone group. After 48 h exposure, the supernatants and cells were collected. The expressions of p22(phox) and p47(phox) in MCs were detected by RT-PCR and western blot. The levels of intracellular ROS were determined by flow cytometry. Coloimetry method was used to detect malondialdehyde (MDA) concentrations and superoxide dismutase (SOD) activities. Results. Compared with the NG group, the expression levels of p22(phox), p47(phox) and ROS significantly increased, the activity of SOD decreased in HG group, while the concentration of MDA greatly increased (P < 0.01). Pioglitazone significantly suppressed HG-induced p22(phox) and p47(phox) expressions and oxidative stress. The protein and gene expressions of p22(phox) and p47(phox) were markedly reduced after pioglitazone treatment, so did the ROS generation. The activities of SOD in MCs increased, while the concentrations of MDA in the supernatant decreased greatly by pioglitazone. Conclusions. Pioglitazone can inhibit HG-induced oxidative stress in MCs through suppressing p22(phox) and p47(phox) expressions.

Correlation between serum cathepsin S and insulin resistance in type 2 diabetes.

Cathepsin S (CatS), a proteolytic enzyme, which belongs to the cysteine proteinase family, is associated with atherosclerosis, coronary heart disease, cancer and other diseases. The present study aimed to explore the correlation between serum CatS and insulin resistance (IR) in patients with type 2 diabetes. A total of 51 patients with type 2 diabetes (Group DM) were recruited for this study and 49 healthy individuals were selected as normal controls (Group NC). Blood pressure and body mass index (BMI) were recorded, and serum creatinine, CatS, glycosylated hemoglobin (HbA1c), lipid and insulin levels, and fasting plasma glucose (FPG) levels were measured in all the participants. The homeostatic model assessment index of IR (HOMA-IR) was calculated according to FPG and serum insulin levels. Serum CatS, very low density lipoprotein (VLDL) and triglyceride (TG) levels in Group DM were significantly higher compared with those in Group NC (P=0.000, 0.014 and 0.020, respectively). Significantly positive correlations were identified between CatS levels and VLDL and TG levels, respectively (P<0.05 for both); however, no significant correlations were determined between CatS levels and age, course of disease, blood pressure, cholesterol, BMI, FPG, HbAc1 and HOMA-IR (P>0.05). Further stratification analysis showed that CatS had no association with IR at different HOMA-IR and HbA1c levels. The present study demonstrated that serum CatS, which was significantly increased in patients with type 2 diabetes, had no correlation with IR. This indicates that CatS and IR are independent of each other; however, the precise mechanisms require further investigation.

Pioglitazone inhibits the expression of nicotinamide adenine dinucleotide phosphate oxidase and p38 mitogen-activated protein kinase in rat mesangial cells.

BACKGROUND: Oxidative Stress and p38 mitogen-activated protein kinase (p38MAPK) play a vital role in renal fibrosis. Pioglitazone can protect kidney but the underlying mechanisms are less clear. The purpose of this study was to investigate the effect of pioglitazone on oxidative stress and whether the severity of oxidative stress was associated with the phosphorylation level of p38MAPK. METHODS: Rat mesangial cells were cultured and randomly assigned to control group, high glucose group and pioglitazone group. After 48-hour exposure, the supernatants and cells were collected. The protein levels of p22(phox), p47(phox), phosphorylated p38MAPK, total p38MAPK were measured by Western blotting. The gene expressions of p22(phox), p47(phox) were detected by RT-PCR. The levels of intracellular reactive oxygen species (ROS) were determined by flow cytometry. The levels of superoxide dismutase (SOD) and maleic dialdehyde (MDA) in the supernatant were determined respectively. RESULTS: Compared with the control group, the expression levels of p22(phox), p47(phox), phospho-p38 and ROS significantly increased, activity of SOD decreased in high glucose group, while the level of MDA greatly increased (P < 0.01). Pioglitazone significantly suppressed p22(phox), p47(phox) expressions and oxidative stress induced by high glucose. The expressions of p22(phox), p47(phox), phospho-p38MAPK and ROS generation were markedly reduced after pioglitazone treatment (P < 0.05). The activity of SOD in the the supernatant increased (P < 0.05), while the level of MDA decreased greatly by pioglitazone (P < 0.05). The level of oxidative stress was associated with the phosphorylation level of p38MAPK (P < 0.01). CONCLUSION: Pioglitazone can inhibit oxidative stress through suppressing NADPH oxidase expression and p38MAPK phosphorylation.