Streptozotocin-induced Diabetic Rat Model Research Articles

Anti‐Diabetic Properties of Rice‐Based Herbal Porridges in Diabetic Wistar Rats

The present study aims to investigate anti-hyperglycaemic, anti-hyperlipidaemic and toxic effects of long-term consumption of selected green leafy porridges in a streptozotocin-induced diabetic Wistar rat model. Porridges made with Asparagus racemosus Willd. (AR), Hemidesmus indicus (L) R. Br. W. T. Aiton (HI), Scoparia dulcis L. (SD) and coconut milk porridge (CM) were incorporated into diets of diabetic Wistar rats. Diabetic control (DM) and normal control groups (NC) were provided with standard rat diet. Fasting blood glucose (FBG), HbA1c , C reactive protein (CRP), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), liver enzymes and creatinine were measured. Feed and water intake among diabetic groups were significantly high when compared with those of NC (p < 0.05). All rats in SD (mean = 39 ± 19 g) and NC (mean = 114 ± 7 g) groups gained weight, whereas most rats in other diabetic groups lost weight. Among the diabetic groups, SD group had the lowest mean FBG, FBG increment percentage (45%) and HbA1c (5.8 ± 2.1). FBG increment percentage and HbA1c of SD group were not significantly different to those of NC (38%; 4.7 ± 0.7) (p > 0.05). Among the diabetic groups, lowest TC (119 ± 20.6 mg/dL) and highest HDL-C (33 ± 6.3 mg/dL) were also detected in SD group. Alanine transaminase and creatinine were not significantly different (p > 0.05) among diabetic groups but significant when compared with those of NC. When compared with those of NC, aspartate transaminase levels were significantly (p < 0.05) high in SD, CM and DM groups. Body weight : liver weight and body weight : pancreas weight ratios and CRP were not significantly different among all groups. The study proved that SD porridge reduced weight loss, elicited hypoglycaemic and hypolipidaemic properties, and caused no toxicity in diabetes-induced Wistar rats.

Hyperglycemia Diverts Dividing Osteoblastic Precursor Cells to an Adipogenic Pathway and Induces Synthesis of a Hyaluronan Matrix That Is Adhesive for Monocytes

Isolated rat bone marrow stromal cells cultured in osteogenic medium in which the normal 5.6 mm glucose is changed to hyperglycemic 25.6 mm glucose greatly increase lipid formation between 21-31 days of culture that is associated with decreased biomineralization, up-regulate expression of cyclin D3 and two adipogenic markers (CCAAT/enhancer binding protein α and peroxisome proliferator-activated receptor γ) within 5 days of culture, increase neutral and polar lipid synthesis within 5 days of culture, and form a monocyte-adhesive hyaluronan matrix through an endoplasmic reticulum stress-induced autophagic mechanism. Evidence is also provided that, by 4 weeks after diabetes onset in the streptozotocin-induced diabetic rat model, there is a large loss of trabecular bone mineral density without apparent proportional changes in underlying collagen matrices, a large accumulation of a hyaluronan matrix within the trabecular bone marrow, and adipocytes and macrophages embedded in this hyaluronan matrix. These results support the hypothesis that hyperglycemia in bone marrow diverts dividing osteoblastic precursor cells (bone marrow stromal cells) to a metabolically stressed adipogenic pathway that induces synthesis of a hyaluronan matrix that recruits inflammatory cells and establishes a chronic inflammatory process that demineralizes trabecular cancellous bone.

MP43-12 INHIBITION OF PHOSPHODIESTERASE-5 IMPROVES THERAPEUTIC EFFICACY OF ADIPOSE-DERIVED STEM CELLS FOR ERECTILE DYSFUNCTION IN DIABETIC RATS

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Basic Research I1 Apr 2014MP43-12 INHIBITION OF PHOSPHODIESTERASE-5 IMPROVES THERAPEUTIC EFFICACY OF ADIPOSE-DERIVED STEM CELLS FOR ERECTILE DYSFUNCTION IN DIABETIC RATS Jun Yang, Tao Wang, Yan Zhang, Li Zhuan, Hua Xu, Shao-Gang Wang, Ji-Hong Liu, and Zhang-Qun Ye Jun YangJun Yang More articles by this author , Tao WangTao Wang More articles by this author , Yan ZhangYan Zhang More articles by this author , Li ZhuanLi Zhuan More articles by this author , Hua XuHua Xu More articles by this author , Shao-Gang WangShao-Gang Wang More articles by this author , Ji-Hong LiuJi-Hong Liu More articles by this author , and Zhang-Qun YeZhang-Qun Ye More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1169AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives Adipsoe-derived stem cells (ADSCs) have been recently considered promising therapy for erectile dysfunction (ED). However, the therapeutic efficacy of ADSCs-based therapy remains to be improved. This study was designed to determine whether inhibition of phosphodiesterase-5 (PDE5) with a silencing vector in adipose-derived stem cells (ADSCs) would improve stem cell therapy for erectile dysfunction in diabetic rats, and to investigate its underlying mechanisms. Methods A PDE5 siRNA was incorporated into lentiviral vectors and then transduced into ADSCs. Cells were evaluated for PDE5 mRNA and protein expression, and cGMP level at different time points. 3 days after transduction, the ADSCs-conditioned medium was collected to determinate the level of IGF-1 and VEGF. A streptozotocin-induced diabetes rat model was established and used for comparative analysis of 2-week treatment regimens with ADSCs or PDE5 siRNA modified ADSCs. At 2-week post-transplantation, all the rats were analyzed for erectile function, cavernous IGF-1 and VEGF levels, and penile histology. Results Compared to ADSCs transfected with negative control siRNA vector (ADSCs plus vector), ADSCs showed a significant decrease in PDE5 expression and elevated cGMP level at 3d, 5d, 7d, 10d and 14d after transfection with PDE5 siRNA vector (ADSCs plus siRNA) (P<0.05). ADSCs plus siRNA could secrete more IGF-1 and VEGF in culture medium than those of ADSCs and ADSCs plus vector (P<0.05). Compared to normal control rats (2.5v 0.711±0.059, n=10), the Max ICP/MAP was found to be markedly decreased in untreated diabetic rats (2.5v 0.355±0.046, n=10) (P<0.05). The corpus cavernosum of untreated diabetic rats showed decreased IGF-1 and VEGF levels, and contents of cavernous smooth muscle and endothelium compared to normal control rats (P<0.05). Diabetic rats injected with ADSCs plus siRNA (2.5v 0.665±0.052, n=10) showed enhanced erectile function as compared to ADSCs (2.5v 0.522±0.043, n=10) or ADSCs plus vector (2.5v 0.515±0.038, n=10) treatment (P<0.05), which also improved erectile function of diabetic rats (P<0.05). The benefits of ADSCs plus siRNA therapy were associated with significantly increased IGF-1 and VEGF levels, and contents of cavernous smooth muscle and endothelium in penile tissues as compared with ADSCs or ADSCs plus vector treatment (P<0.05). Conclusions Inhibition of PDE5 can be a powerful approach to improve stem cell therapy for erectile dysfunction in diabetic rats. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e481 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Jun Yang More articles by this author Tao Wang More articles by this author Yan Zhang More articles by this author Li Zhuan More articles by this author Hua Xu More articles by this author Shao-Gang Wang More articles by this author Ji-Hong Liu More articles by this author Zhang-Qun Ye More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Sphingosine kinase 1 improves cutaneous wound healing in diabetic rats

BackgroundDiabetes is one of the most prevalent human metabolic diseases. Wound healing in diabetes is frequently impaired and treatment remains challenging. Sphingolipid metabolites play important roles in the regulation of glucose metabolism. SPK1 is the key enzyme in the sphingolipid metabolic pathway. S1P/SPK plays a pivotal role in the signalling pathways of diverse cellular processes including proliferation, differentiation, migration, apoptosis in diverse cell types. MethodsTo investigate the role of sphingosine kinase 1 (SPK1) in skin injury, plasmids containing the SPK1 gene (pcDNA3-FLAG-SPK1) were applied to cutaneous wounds on a streptozotocin-induced diabetic rat model over a 21-day period. The wound area and rate of wound healing were determined. The histopathological features of the healed wounds were also observed, and SPK1 expression in the skin was detected by immunohistochemistry. ResultsThere was a significant decrease in wound area in diabetic rats treated with 125 and 60μg/wound pcDNA3-FLAG-SPK1 (P<0.001–0.01). The mean sizes of the wounds were 0.67±0.15cm2, 0.83±0.18cm2, and 1.09±0.23cm2 in both treated and diabetic control group at the 7th day post-treatment respectively. In addition, wound healing in diabetic rats of test group was accelerated. At the 7th day, the mean rates of healing were 73.2±5.7% and 66±7.3% in test group of 125 and 60μg/wound respectively, and 55.4±9.9% in diabetic control group (P<0.001–0.01). Histology revealed that tissue sections from the treated diabetic rats contained more granulation tissue and capillaries than that of the control rats. There was high SPK1 expression in the skin of the treated diabetic rats. ConclusionsSPK1 gene therapy may represent a novel approach to cutaneous wound healing.

The co-occurrence of myocardial dysfunction and peripheral insensate neuropathy in a streptozotocin-induced rat model of diabetes

BackgroundCardiomyopathy and distal symmetrical polyneuropathy (DSPN), including sensory and autonomic dysfunction, often co-occur in diabetic mellitus (DM) patients. However, the temporal relationship and progression between these two complications has not been investigated. Using a streptozotocin DM animal model that develops insensate neuropathy, our aim was to examine in parallel the development of DSPN and DM-associated changes in cardiac structure and function as well as potential mechanisms, such as autonomic dysfunction, evaluated by changes in urinary and myocardial norepinephrine content and myocardial neuronal markers.MethodsSensory neuropathy was measured by behavioral tests using Von Frey filaments and Hargreaves methods. Echocardiography was used to evaluate myocardial structure and function. Autonomic function was evaluated by measuring urinary and myocardial norepinephrine (NE) levels by enzyme-linked immunosorbent assay and high-performance liquid chromatography/mass spectrometry. Quantitative immunohistochemistry was used to measure the myocardial neuronal markers, calcitonin gene-related peptide (CGRP) and general neuronal protein gene product 9.5 (PGP 9.5).ResultsThe DM group developed tactile and thermal insensate neuropathy 4–5 weeks after DM onset. Cardiovascular changes were found between 4 and 12 weeks after DM onset and included bradycardia, diastolic and systolic dysfunction and cardiac dilation. There was a 2.5-fold reduction in myocardial NE levels and a 5-fold increase in urinary NE levels in the DM group. Finally, there was a 2.3-fold increase in myocardial CGRP levels in the DM group and no change in PGP9.5 levels.ConclusionsCardiovascular structural and functional changes developed early in the course of DM and in combination with insensate neuropathy. In parallel, signs of cardiac autonomic dysfunction were also found and included decreased myocardial NE levels and altered CGRP levels. These results may indicate the need for early cardiovascular evaluation in DM patients with insensate neuropathy.

Immunohistochemical evaluation of antidiabetic effect ofMomordica charantiaextract in cow urine in streptozotocin-induced diabetic rat model

Momordica charantia, also referred to as bitter gourd or karela, is a member of the Cucurbitaceae family and is commonly used as a traditional remedy for diabetes in India, Asia, Africa and South America. According to Sushruta Samhita and Ayurveda Samgraha for medicinal and other purposes cow urine is beneficial and better than of all other animals. The present study was undertaken to evaluate the antidiabetic effect of Momordica charantia extract and cow urine in streptozotocin-induced diabetic rat model using immunohistochemistry for a period of 45 days. The alcoholic extract of Momordica charantia was administered orally at the dose rate of 200 mg/kg body weight in cow urine and compared with standard oral hypoglycaemic drug, glibenclamide. Immunohistochemistry revealed improvement in the insulin secretion in various treatment groups with Momordica charantia 200 mg/kg body weight in cow urine being more effective compared to Momordica charantia 200 mg/kg body weight in distilled water.

Protective Effects of Hydrogen-Rich Saline Against Erectile Dysfunction in a Streptozotocin Induced Diabetic Rat Model

Protective Effects of Hydrogen-Rich Saline Against Erectile Dysfunction in a Streptozotocin Induced Diabetic Rat Model

Serum Proteomic Analysis of Extracorporeal Shock Wave Therapy–Enhanced Diabetic Wound Healing in a Streptozotocin-Induced Diabetes Model

Previous studies have demonstrated that extracorporeal shock wave therapy has a significant positive effect on accelerating diabetic wound healing. However, the systemic effect after therapy is still unclear. This study investigated the plasma protein expression in the extracorporeal shock wave therapy group and diabetic controls using proteomic study. A dorsal skin defect (6 × 5 cm) in a streptozotocin-induced diabetic Wistar rat model was used. Diabetic rats receiving either no therapy or extracorporeal shock wave therapy after wounding were analyzed. The spots of interest were subjected to in-gel trypsin digestion and matrix-assisted laser desorption ionization time-of-flight mass spectrometry to elucidate the peptide mass fingerprints. The mass spectrometric characteristics of the identified proteins, including their theoretical isoelectric points, molecular weights, sequence coverage, and Mascot score, were analyzed. Protein expression was validated using immunohistochemical analysis of topical periwounding tissues. The proteomic study revealed that at days 3 and 10 after therapy rats had significantly higher abundance of haptoglobin and significantly lower levels of the vitamin D-binding protein precursor as compared with the diabetic controls. Immunohistochemical staining of topical periwounding tissue also revealed significant upregulation of haptoglobin and downregulation of vitamin D-binding protein expression in the extracorporeal shock wave therapy group, which was consistent with the systemic proteome study. Proteome analyses demonstrated an upregulation of haptoglobin and a downregulation of vitamin D-binding protein in extracorporeal shock wave therapy-enhanced diabetic wound healing.

Investigation of the in vivo antioxidative activity of Cynara scolymus (artichoke) leaf extract in the streptozotocin‐induced diabetic rat

The in vivo antioxidant activity of a quantified leaf extract of Cynara scolymus (artichoke) was studied. The aqueous artichoke leaf extract (ALE), containing 1.5% caffeoylquinic acid with chlorogenic acid being most abundant (0.30%), and luteolin-7-O-glucoside as major flavonoid (0.15%), was investigated by evaluating the effect on different oxidative stress biomarkers, after 3 wk oral supplementation in the streptozotocin-induced diabetic rat model. Apart from two test groups (0.2 g ALE/kg BW/day and 1 g ALE/kg BW/day, where BW is body weight), a healthy control group, untreated oxidative stress group, and vitamin E treated group (positive control) were included. A 0.2 g/kg BW/day of ALE decreased oxidative stress: malondialdehyde and 8-hydroxydeoxyguanosine levels significantly diminished, whereas erythrocyte glutathione levels significantly increased. A 1.0 g/kg BW/day ALE did not show higher antioxidant activity.

The effects of new herbal formula (KBMSI-2) on penile erection and expression of nitric oxide synthase isoforms in streptozotocin-induced diabetic rat model.

To investigate the effects of new herbal formula (KBMSI-2) on erectile dysfunction in streptozotocin (STZ)-induced diabetic rat model. Twenty four Sprague-Dawley male rats were randomly divided into three groups; control (n=8), diabetes model (n=8), diabetes + KBMSI-2 200 mg/kg treatment (n=8) groups. The diabetes induced groups received a single intraperitoneal injection of STZ. Distilled water was administered in the control and model groups. To investigate the penile erection, intracavernosal pressure (ICP) and intracavernosal pressure/mean arterial pressure (ICP/MAP) were recorded in all groups. Serial sections of the penis were used to perform Masson's trichrome stain. The expression of neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS) and cyclic guanosine monophosphate (cGMP) concentration in the isolated corpus cavernosum were analyzed by Western blotting. Peak ICP/MAP ratio was increased in the KBMSI-2 treatment group compared with the model group (P<0.05). Masson's trichrome staining confirmed that the smooth muscle component was increased in the KBMSI-2 treatment group compared with the model group (P<0.05). The nNOS, eNOS and cGMP expression of KBMSI-2 200 mg/kg treatment group was increased compared with the model group (P<0.05). This study showed that herbal formula of KBMSI-2 improved the erectile function by preserving the smooth muscle content and inhibiting the fibrosis of the corpus cavernosum in STZ-induced diabetic rat model.

Chondroitin sulfate-capped gold nanoparticles for the oral delivery of insulin

Chondroitin sulfate (CS)-capped gold nanoparticles (AuNPs) were synthesized and its feasibility for oral insulin (INS) delivery was investigated in vivo. CS was used as both reducing and stabilizing agent in the synthesis of AuNPs with around 48nm mean diameter, narrow size distribution, and negative zeta potential. After loading INS into CS-capped AuNPs structure, NPs with about 123nm mean diameter, narrow size distribution, and negative zeta potential were successfully fabricated. By surface plasmon resonance (SPR) measurement, 0.5% (w/v) CS was chosen for the synthesis of AuNPs. Stability of AuNPs and AuNPs/INS was maintained for 7 weeks according to SPR study. Cytotoxicity of AuNPs/INS in Caco-2 cells was measured and no significant cytotoxicity was observed in tested AuNPs concentration range. In the streptozotocin-induced diabetic rat model, the oral administration of AuNPs/INS exhibited an efficient regulation of glucose level, compared to INS solution-treated group. The mean INS concentration in plasma at 120min after oral administration of AuNPs/INS was 6.61-fold higher than that of INS solution-administered group. All of these findings indicate the successful application of CS-capped AuNPs for oral delivery of INS to the therapy of diabetes.

Potential of Nonoral α-Lipoic Acid Aqueous Formulations to Reduce Ocular Microvascular Complications in a Streptozotocin-Induced Diabetic Rat Model

α-Lipoic acid (LA) aqueous formulations were studied for nonoral administration, including intravitreal and intraperitoneal preparations and topical eyedrops. The potential retinoprotective effects of these LA preparations were also evaluated in streptozotocin (STZ)-induced diabetic rats for screening better delivery systems of LA. Four LA liquid preparations were prepared and investigated. The short-term accelerated stabilities of LA preparations were investigated at 3 temperatures: 50°C, 70°C, and 90°C. The time courses of LA degradation in the preparations were determined by high-performance liquid chromatography. Furthermore, the potential therapeutic effects of LA preparations in a STZ-induced diabetic rat model were assessed by vitreous fluorophotometry to evaluate the fluorescein leakage from ocular vascular vessels into the vitreous. Capillary lesion in the retina was also examined using hematoxylin-eosin-stained microsections. LA in an aqueous solution was rapidly degraded with the activation energy of 10.4 kcal/mol. The 3 LA preparations had shelf lives of ∼1 month at 25°C. These formulations significantly reduced the vitreous fluorescein level in STZ-induced diabetic rats as evaluated by the fluorescein leakage after tail vein injection. Capillary lesions in the retina of the diabetic rats were remarkably reduced by nonoral administration, particularly the intraperitoneal injection (30 mg/kg/day). LA could be developed as aqueous preparations with suitable stability for short-term use in nonoral administration. LA preparations could be administered intravitreally or intraperitoneally to reduce ocular microvascular complications, such as retinopathy, in diabetic patients.

Synthesis, Evaluation and Molecular Docking of Prolyl-Fluoropyrrolidine Derivatives as Dipeptidyl Peptidase IV Inhibitors

A series of prolyl-fluoropyrrolidine derivatives were designed, synthesized and screened for in vitro inhibition of dipeptidyl peptidase IV. The SAR study revealed the influence of substituted chemical modifications on dipeptidyl peptidase IV inhibitory activity. Among all the compounds screened, compound 9 (IC50 =0.83μm) and 10 (IC50 =0.43μm) possessing aryl substituted piperazine with acetamide linker resulted as most potent dipeptidyl peptidase IV inhibitors. Both the compounds 9 and 10 resulted significant reduction in glucose excursion during oral glucose tolerance test in streptozotocin-induced diabetic rat model at single dose of 10mg/kg. Molecular docking studies were performed to illustrate the probable binding mode and interactions of prolyl-fluoropyrrolidine nucleus and its derivatives at binding site of receptor. The fluoropyrrolidine moiety of prolyl-fluoropyrrolidine derivatives occupied S1 pocket as observed in the crystal structure (PDB id: 2FJP). The compounds 9 and 10 were observed to occupy S2 binding pocket and were observed to have interaction with Arg125, Tyr547 and Ser630 acquired through hydrogen bond. The aryl moiety at piperazine ring was found to extend into the cavity and interacted with Arg358. The observed interactions signalled that occupancy of the highly hydrophobic S2 pocket is very crucial for dipeptidyl peptidase IV inhibitory activity.

Decursin inhibited proliferation and angiogenesis of endothelial cells to suppress diabetic retinopathy via VEGFR2

Diabetes induces pathologic proliferation and angiogenesis in the retina that leads to catastrophic loss of vision. Decursin is a novel therapeutic that targets the vascular endothelial growth factor (VEGF) receptor (VEGFR) with putative anti-proliferative and anti-angiogenic activities. Thereby we utilized human retinal microvascular endothelial cells (HRMEC) and human umbilical vein endothelial cells (HUVEC) under conditions of excess glucose to explore dose-dependent responses of decursin on markers of migration, angiogenesis, and proliferation. Decursin dose-dependently inhibited tube formation, VEGFR-2 expression, along with relative metabolic activity and 5-bromo-2′-deoxy-uridine (BrdU) activity in both cell lines. We then correlated our findings to the streptozotocin-induced rat model of diabetes. Following three months of decursin treatment VEGFR-2 expression was significantly inhibited. Our data would suggest that decursin may be a potent anti-angiogenic and anti-proliferative agent targeting the VEGFR-2 signaling pathway, which significantly inhibits diabetic retinal neovascularization.

Combating diabetes complications by 1-Fe, a corrole-based catalytic antioxidant

The potent corrole-based ROS/RNS decomposition catalyst 1-Fe was examined regarding its effect on the development of diabetes complications, in parallel with studies that addressed safety and toxicity issues that are crucial for forwarding the compound towards clinical trials. Cardiotoxicity and mutagenic potential were addressed by applying the hERG and AMES tests on 1-Fe, revealing that it is safe enough for further development. General toxicity studies in rats disclosed the appearance of mild adverse effect only at a dose of 300mg/kg/day. In the streptozotocin-induced rat model of diabetes, 20mg/kg/day 1-Fe prevented cataract incidents and reduced its severity, displayed a favorable effect on kidney function, and also decreased serum cholesterol and triglyceride levels. Comparisons with alpha lipoic acid, a compound with reported benefits in the same mouse model, indicate that the benefits of 1-Fe are due to the combination of its ability to disarm ROS/RNS and its positive effect on lipid profile.

1029 IDENTIFICATION OF MICRORNA EXPRESSION PROFILE IN DIABETIC RATS' PENILE TISSUES AND POTENTIAL ROLE OF MIR-92A IN ERECTILE DYSFUNCTION

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Basic Research (II)1 Apr 20131029 IDENTIFICATION OF MICRORNA EXPRESSION PROFILE IN DIABETIC RATS' PENILE TISSUES AND POTENTIAL ROLE OF MIR-92A IN ERECTILE DYSFUNCTION Jun Yang, Tao Wang, Hua Xu, Shaogang Wang, Jihong Liu, and Zhangqun Ye Jun YangJun Yang Wuhan, China, People's Republic of More articles by this author , Tao WangTao Wang Wuhan, China, People's Republic of More articles by this author , Hua XuHua Xu Wuhan, China, People's Republic of More articles by this author , Shaogang WangShaogang Wang Wuhan, China, People's Republic of More articles by this author , Jihong LiuJihong Liu Wuhan, China, People's Republic of More articles by this author , and Zhangqun YeZhangqun Ye Wuhan, China, People's Republic of More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.614AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES MicroRNAs are a recently discovered class of endogenous, small, noncoding RNAs, which play regulatory roles in several biological processes. However, the role of miRNAs in erectile dysfunction (ED) is currently completely unknown. This study was designed to identify specific miRNA whose expression is altered in diabetes-related ED and explore the role of miR-92a in diabetes-induced ED. METHODS A streptozotocin-induced diabetes rat model was established and the erectile function was evaluated by electrical stimulation of cavernous nerve twelve weeks after diabetes induction. Global miRNAs expression in penile tissues from normal rats and diabetic ED rats were measured using Agilent micoRNA microarray and the aberrantly expressed miRNAs were further confirmed by quantitative real-time polymerase chain reaction (PCR). The mRNA and protein expression level of endothelial nitric oxide synthase (eNOS) were detected by quantitative real-time PCR and western blot. MiR-92a functional assays were performed on rat aortic endothelial cells. RESULTS Compared to normal control rats, the erectile function (the ratio of maximal intracavernous pressure to mean arterial blood pressure) was found to be dramatically decreased in diabetic rats. Twenty-eight miRNAs were identified significantly dysregulated in diabetic rat's penile tissues. Among these altered miRNAs, miR-92a expression was dramatically up-regulated in diabetes-induced ED. The expression level of eNOS was significantly lower in diabetic rats' penes than that in normal control rats. Overexpression of miR-92a significantly decreased the expression of eNOS mRNA and protein in rat aortic endothelial cells. On the contrary, inhibition of miR-92a significantly increased the expression of eNOS mRNA and protein in rat aortic endothelial cells. CONCLUSIONS This is the first report demonstrating the altered microRNA expression signature in diabetes-associated ED. In vitro study showed that miR-92a was an important regulator of eNOS expression in endothelial cells, indicating upregulation of miR-92a might play an important role in diabetes-associated deterioration of erectile function. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e421-e422 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jun Yang Wuhan, China, People's Republic of More articles by this author Tao Wang Wuhan, China, People's Republic of More articles by this author Hua Xu Wuhan, China, People's Republic of More articles by this author Shaogang Wang Wuhan, China, People's Republic of More articles by this author Jihong Liu Wuhan, China, People's Republic of More articles by this author Zhangqun Ye Wuhan, China, People's Republic of More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Anti-inflammatory effects of triptolide improve left ventricular function in a rat model of diabetic cardiomyopathy

AimsGiven the importance of inflammation in the onset and progression of diabetic cardiomyopathy, we investigated the potential protective effects of triptolide, an anti-inflammatory agent, in streptozotocin-induced diabetic rat model and in H9c2 rat cardiac cells exposed to high glucose.Methods and resultsDiabetic rats were treated with triptolide (100, 200, or 400 μg/kg/day respectively) for 6 weeks. At the end of this study, after cardiac function measurements were performed, rats were sacrificed and their hearts were harvested for further histologic and molecular biologic analysis. Enhanced activity and expression of nuclear factor-kappaB (NF-κB) p65 in diabetic hearts were associated with increased inflammatory response, as demonstrated by increased pro-inflammatory cytokines, cell adhesion molecules and invading inflammatory cells, as well as increased fibrosis, in line with impaired left ventricular function. Triptolide attenuated these morpho-functional alterations. Furthermore, triptolide (20 ng/ml) also attenuated high glucose-induced inflammation in H9c2 rat cardiac cells.ConclusionOur data demonstrate that anti-inflammatory effects of triptolide involving the NF-κB signaling pathway can improve left ventricular function under diabetic conditions, suggesting triptolide treatment might be beneficial in diabetic cardiomyopathy.

S‐allyl cysteine restores erectile function through inhibition of reactive oxygen species generation in diabetic rats

Excessive production of reactive oxygen species (ROS) by an overactive nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system in penile tissue is an important mechanism of erectile dysfunction (ED). S-allyl cysteine (SAC), a bioactive component derived from garlic, was recently reported to exert versatile antioxidant properties. We hypothesized that SAC would be able to resolve diabetes-related ED by reducing ROS generation, and designed this study to investigate this possibility as well as to determine the related underlying mechanisms. A streptozotocin-induced diabetes rat model was established and used for comparative analysis of 4-week treatment regimens with insulin or SAC. The ratio of maximal intracavernous pressure (ICP) to mean arterial blood pressure (MAP) was measured to determine erectile function. Differential levels of ROS, NADPH oxidase subunits, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signalling pathway, and apoptosis were evaluated in cavernous tissues. Max ICP/MAP was found to be markedly decreased in untreated diabetic rats; SAC, but not insulin, treatment restored the ratio to baseline (in non-diabetic untreated controls). The corpus cavernosum of untreated diabetic rats showed increased p47(phox) and p67(phox) expression, ROS production and penile apoptotic index, and decreased phospho-endothelial nitric oxide synthase (phospho-eNOS, Ser1177) expression, cGMP concentration, B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) ratio and smooth muscle cell number. SAC treatment normalized all the diabetes-induced effects, whereas insulin treatment partially normalized the alterations, but produced no effects on P47(phox) expression, penile ROS level, apoptotic index, Bcl-2/Bax ratio and smooth muscle cell number. Collectively, these data indicate that SAC treatment can restore erectile function in diabetic rats by preventing ROS formation through modulation of NADPH oxidase subunit expression. Furthermore, the poor efficacy of conventional insulin treatment for diabetic ED may be associated with an elevated level of ROS in penile tissue.

Cell-Based Screening Identifies Paroxetine as an Inhibitor of Diabetic Endothelial Dysfunction

We have conducted a phenotypic screening in endothelial cells exposed to elevated extracellular glucose (an in vitro model of hyperglycemia) to identify compounds that prevent hyperglycemia-induced reactive oxygen species (ROS) formation without adversely affecting cell viability. From a focused library of >6,000 clinically used drug-like and pharmacologically active compounds, several classes of active compounds emerged, with a confirmed hit rate of <0.5%. Follow-up studies focused on paroxetine, a clinically used antidepressant compound that has not been previously implicated in the context of hyperglycemia or diabetes. Paroxetine reduced hyperglycemia-induced mitochondrial ROS formation, mitochondrial protein oxidation, and mitochondrial and nuclear DNA damage, without interfering with mitochondrial electron transport or cellular bioenergetics. The ability of paroxetine to improve hyperglycemic endothelial cell injury was unique among serotonin reuptake blockers and can be attributed to its antioxidant effect, which primarily resides within its sesamol moiety. Paroxetine maintained the ability of vascular rings to respond to the endothelium-dependent relaxant acetylcholine, both during in vitro hyperglycemia and ex vivo, in a rat model of streptozotocin-induced diabetes. Thus, the current work identifies a novel pharmacological action of paroxetine as a protector of endothelial cells against hyperglycemic injury and raises the potential of repurposing of this drug for the experimental therapy of diabetic cardiovascular complications.

Adipose tissue-derived mesenchymal stromal cells efficiently differentiate into insulin-producing cells in pancreatic islet microenvironment both in vitro and in vivo

Background aimsDifferentiation or reprogramming of stem cells could be achieved by remodulating the microenvironment, which regulates the fate of cells by soluble factors and contacts. By providing an in vivo-like microenvironment, directional and functional differentiation of stem cells could be achieved in vitro. In this study, the differentiation of mesenchymal stromal cells (MSCs) derived from rat tissues (adipose, rAT; bone marrow, rBM) were analyzed by in vitro and in vivo co-culture experiments. The insulin-producing capacities of islets transplanted under the renal kidney capsule with rAT- and rBM-MSCs were compared and the reduction of hyperglycemia symptoms in rat models was examined. MethodsMSCs prelabeled with green fluorescence protein were co-cultured with islets directly. The insulin production of cells was determined by immunostaining and ELISA. Streptozotocin-induced diabetic rat models were created and MSCs were co-transplanted with the islets under the kidney capsule to confirm the in vitro results. ResultsMSCs were differentiated into insulin-producing cells after 38 days of co-culture, confirmed by insulin and C-peptide stainings. In vivo functional studies revealed that the co-culture of islets with MSCs provided higher differentiation efficiency. The weight gain measurement and glucose tolerance test in the rat group co-transplanted of rAT-MSCs and islets indicate a better recovery than islet-alone transplants and co-transplants of islets and rBM-MSCs. ConclusionsrAT-MSCs could be considered as the cell of choice for cell-based treatment of type 1 diabetes. Because the co-transplantation of islets with MSCs increases the number of insulin-producing cells, this method was suggested for clinical applications.