Angelica Dahurica ethanolic extract improves impaired wound healing by activating angiogenesis in diabetes.

Abnormal angiogenesis plays an important role in impaired wound healing and development of chronic wounds in diabetes mellitus. Angelica dahurica radix is a common traditional Chinese medicine with wide spectrum medicinal effects. In this study, we analyzed the potential roles of Angelica dahurica ethanolic extract (ADEE) in correcting impaired angiogenesis and delayed wound healing in diabetes by using streptozotocin-induced diabetic rats. ADEE treatment accelerated diabetic wound healing through inducing angiogenesis and granulation tissue formation. The angiogenic property of ADEE was subsequently verified ex vivo using aortic ring assays. Furthermore, we investigated the in vitro angiogenic activity of ADEE and its underlying mechanisms using human umbilical vein endothelial cells. ADEE treatment induced HUVECs proliferation, migration, and tube formation, which are typical phenomena of angiogenesis, in dose-dependent manners. These effects were associated with activation of angiogenic signal modulators, including extracellular signal-regulated kinase 1/2 (ERK1/2), Akt, endothelial nitric oxide synthase (eNOS) as well as increased NO production, and independent of affecting VEGF expression. ADEE-induced angiogenic events were inhibited by the MEK inhibitor PD98059, the PI3K inhibitor Wortmannin, and the eNOS inhibitor L-NAME. Our findings highlight an angiogenic role of ADEE and its ability to protect against impaired wound healing, which may be developed as a promising therapy for impaired angiogenesis and delayed wound healing in diabetes.

Protective effects of triptolide on TLR4 mediated autoimmune and inflammatory response induced myocardial fibrosis in diabetic cardiomyopathy.

ETHNOPHARMACOLOGICAL RELEVANCE: Triptolide is a most important active ingredient extracted from traditional Chinese medicine Tripterygium, which has been widely used to treat glomerulonephritis as well as immune-mediated disorders, likely for its immunosuppressive, anti-proliferative and anti-inflammatory effects. AIM OF THE STUDY: In this study, we have investigated the potential protective effects of triptolide against diabetic cardiomyopathy (DCM) by regulating immune system, attenuating inflammatory response, thus resulting in decreased cardiac fibrosis and improved left ventricle function. MATERIALS AND METHODS: Sprague-Dawley rats were randomly divided into 5 groups: normal group, diabetic group and diabetic rats treated with triptolide (50, 100, or 200µg/kg/day resp) for 8 weeks. Cardiac function was performed by echocardiography and histopathology of the hearts was examined with HE, Masson staining and scanning electron microscopy. Immune regulation mediator, macrophage infiltration, inflammatory response and cardiac fibrosis related cytokines were measured by RT-PCR, Western blot and Immunohistochemistry staining. RESULTS: In the diabetic group, the expressions of TLR4 and NF-κB p65 were both up-regulated, which was associated with increased pro-inflammatory cytokines, coupled with cardiac fibrosis and impaired left ventricular function. Interestingly, pathological structure and function of left ventricle were both significantly improved in the triptolide treated groups. Furthermore, the immune mediator TLR4, downstream activator NF-κB p65, macrophage infiltration (CD68+), pro-inflammatory cytokines (TNF-α, IL-1ß), cell adhesion molecule (VCAM-1) and chemokine (MCP-1) were significantly suppressed when treated with medium and high dosage triptolide compared with the diabetic group. Moreover, cardiac fibrosis pathway including α-SMA, TGF-ß1, vimentin and collagen accumulations were observed significantly decreased in the triptolide treated groups. CONCLUSIONS: Our data demonstrated that the protective effects of triptolide against DCM might attribute to inhibition of TLR4-induced NF-κB/IL-1ß immune pathway, suppression of NF-κB/TNF-α/VCAM-1 inflammatory pathway and down-regulation of TGF-ß1/α-SMA/Vimentin fibrosis pathway.

Protective Effects of Celastrol on Diabetic Liver Injury via TLR4/MyD88/NF-κB Signaling Pathway in Type 2 Diabetic Rats.

Immune and inflammatory pathways play a central role in the pathogenesis of diabetic liver injury. Celastrol is a potent immunosuppressive and anti-inflammatory agent. So far, there is no evidence regarding the mechanism of innate immune alterations of celastrol on diabetic liver injury in type 2 diabetic animal models. The present study was aimed at investigating protective effects of celastrol on the liver injury in diabetic rats and at elucidating the possible involved mechanisms. We analyzed the liver histopathological and biochemical changes and the expressions of TLR4 mediated signaling pathway. Compared to the normal control group, diabetic rats were found to have obvious steatohepatitis and proinflammatory cytokine activities were significantly upregulated. Celastrol-treated diabetic rats show reduced hepatic inflammation and macrophages infiltration. The expressions of TLR4, MyD88, NF-κB, and downstream inflammatory factors IL-1ß and TNFα in the hepatic tissue of treated rats were downregulated in a dose-dependent manner. We firstly found that celastrol treatment could delay the progression of diabetic liver disease in type 2 diabetic rats via inhibition of TLR4/MyD88/NF-κB signaling cascade pathways and its downstream inflammatory effectors.

The Four-Herb Chinese Medicine Formula Tuo-Li-Xiao-Du-San Accelerates Cutaneous Wound Healing in Streptozotocin-Induced Diabetic Rats through Reducing Inflammation and Increasing Angiogenesis.

Impaired wound healing in diabetic patients is a serious complication that often leads to amputation or even death with limited effective treatments. Tuo-Li-Xiao-Du-San (TLXDS), a traditional Chinese medicine formula for refractory wounds, has been prescribed for nearly 400 years in China and shows good efficacy in promoting healing. In this study, we explored the effect of TLXDS on healing of diabetic wounds and investigated underlying mechanisms. Four weeks after intravenous injection of streptozotocin, two full-thickness excisional wounds were created with a 10 mm diameter sterile biopsy punch on the back of rats. The ethanol extract of TLXDS was given once daily by oral gavage. Wound area, histological change, inflammation, angiogenesis, and collagen synthesis were evaluated. TLXDS treatment significantly accelerated healing of diabetic rats and improved the healing quality. These effects were associated with reduced neutrophil infiltration and macrophage accumulation, enhanced angiogenesis, and increased collagen deposition. This study shows that TLXDS improves diabetes-impaired wound healing.

Tripterygium Glycosides Tablet Ameliorates Renal Tubulointerstitial Fibrosis via the Toll-Like Receptor 4/Nuclear Factor Kappa B Signaling Pathway in High-Fat Diet Fed and Streptozotocin-Induced Diabetic Rats.

Tripterygium glycosides tablet (TGT) is a Chinese traditional medicine that has been shown to protect podocytes from injury and reduce the proteinuria. The aim of this study was to assess the effect of TGT on renal tubulointerstitial fibrosis and its potential mechanism in high-fat diet fed and STZ-induced diabetic rats. Rats were randomly divided into normal control rats (NC group), diabetic rats without drug treatment (DM group), and diabetic rats treated with TGT (1, 3, or 6 mg/kg/day, respectively) for 8 weeks. The results showed that 24 h proteinuria and urinary N-acetyl-glucosaminidase (NAG) in diabetic rats were decreased by TGT treatment without affecting blood glucose. Masson's trichrome stains showed that apparent renal tubulointerstitial fibrosis was found in DM group, which was ameliorated by TGT treatment. The expression of α-SMA was significantly decreased, accompanied by increased expression of E-cadherin in TGT-treated rats, but not in untreated DM rats. Further studies showed that TGT administration markedly reduced expression of TLR4, NF-κB, IL-1ß, and MCP-1 in TGT-treated diabetic rats. These results showed that TGT could ameliorate renal tubulointerstitial fibrosis, the mechanism which may be at least partly associated with the amelioration of EMT through suppression of the TLR4/NF-κB pathway.

Association between eNOS 4b/a polymorphism and the risk of diabetic retinopathy in type 2 diabetes mellitus: a meta-analysis.

Many studies have assessed the association between eNOS-4b/a polymorphism and the risk of diabetic retinopathy (DR) among type 2 diabetic subjects. However, the results are inconsistent. In order to derive a more precise estimation of the association, a meta-analysis was conducted. Fifteen studies with 3, 183 cases and 3, 410 controls were enrolled by searching the databases of Pubmed, Embase, China National Knowledge Infrastructure (CNKI), and Chinese Wanfang Database. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. The main analysis indicated no significant association between eNOS-4b/a polymorphism and the risk of DR in overall population [allelic model: OR = 0.94 (0.79-1.11); additive model: OR = 0.91 (0.73-1.14); recessive model: OR = 1.01 (0.81-1.25); dominant model: OR = 0.91 (0.75-1.09)]. Subgroup analysis by ethnicity also indicated no significant association. In conclusion, the current meta-analysis did not observe any association between the polymorphism of eNOS 4b/a and the risk of DR among type 2 diabetic subjects. However, larger well-designed studies are required to confirm this finding.

Endothelial nitric oxide synthase (eNOS) 4b/a polymorphism and the risk of diabetic nephropathy in type 2 diabetes mellitus: A meta-analysis.

Many studies have accessed the association between eNOS-4b/a polymorphism and the risk of diabetic nephropathy (DN) among type 2 diabetic subjects. However, the results are conflicting and inconclusive. The aim of current meta-analysis was to more precisely estimate the relationship. Pubmed, Embase, the China National Knowledge Infrastructure and the Wanfang Database were searched for articles published up to May 26th, 2013 that addressed eNOS-4b/a polymorphism and the risk of DN among type 2 diabetic subjects. 18 studies were included in this meta-analysis. eNOS-4b/a polymorphisms were associated with an overall significantly increased risk of DN (allele model: OR = 1.44, 95% CI = 1.14-1.82; additive model: OR = 2.03, 95% CI = 1.14-3.62; dominant model: OR = 1.34, 95% CI = 1.07-1.68; recessive model: OR = 2.01, 95% CI = 1.12-3.61). Subgroup analysis revealed a significant association between the eNOS-4b/a polymorphism and DN in Asian population, especially in Chinese population, but not in non Asian populations. Our meta-analysis supported an association between the 4b/a polymorphism of eNOS gene and increased risk of DN in type 2 diabetes among Asians, especially in Chinese population.

Reduced beta2-glycoprotein I protects macrophages from ox-LDL-induced foam cell formation and cell apoptosis.

BACKGROUND: Reduced beta2-glycoprotein I (beta2-GPI) is a free thiol-containing form of beta2-GPI that displays a powerful effect in protecting endothelial cells from oxidative stress-induced cell death. The present study aims to investigate the effect of beta2-GPI or reduced beta2-GPI on ox-LDL-induced foam cell formation and on cell apoptosis and to determine the possible mechanisms. METHODS: The RAW264.7 macrophage cell line was selected as the experimental material. Oil red O staining and cholesterol measurement were used to detect cholesterol accumulation qualitatively and quantitatively, respectively. Flow cytometry was used to detect cell apoptosis. Real-time quantitative PCR was used to detect the mRNA expression of the main proteins that are associated with the transport of cholesterol, such as CD36, SRB1, ABCA1 and ABCG1. Western blot analysis was used to detect the protein expression of certain apoptosis-related proteins, such as caspase-9, caspase-3, p38 MAPK/p-p38 MAPK and JNK/p-JNK. RESULTS: Beta2-GPI or reduced beta2-GPI decreased ox-LDL-induced cholesterol accumulation (96.45 ± 8.51 µg/mg protein vs. 114.35 ± 10.38 µg/mg protein, p < 0.05;74.44 ± 5.27 µg/mg protein vs. 114.35 ± 10.38 µg/mg protein, p < 0.01) and cell apoptosis (30.00 ± 5.10% vs. 38.70 ± 7.76%, p < 0.05; 20.66 ± 2.50% vs. 38.70 ± 7.76%, p < 0.01), and there are significant differences between beta2-GPI and reduced beta2-GPI (p < 0.05). Reduced beta2-GPI decreased the ox-LDL-induced expression of CD36 mRNA and ABCA1 mRNA (p < 0.05), as well as CD36, cleaved caspase-9, cleaved caspase-3, p-p38 MAPK and p-JNK proteins (p < 0.05 or p < 0.01). Beta2-GPI did not significantly decrease the expression of ABCA1 mRNA and the p-p38 MAPK protein. CONCLUSIONS: Both beta2-GPI and reduced beta2-GPI inhibit ox-LDL-induced foam cell formation and cell apoptosis, and the latter exhibits a stronger inhibition effect. Both of these glycoproteins reduce the lipid intake of macrophages by downregulating CD36 as well as protein expression. Reduced beta2-GPI inhibits cell apoptosis by reducing the ox-LDL-induced phosphorylation of p38 MAPK and JNK, and the amount of cleaved caspase-3 and caspase-9. Beta2-GPI does not inhibit the ox-LDL-induced phosphorylation of p38 MAPK.

Association of the HLA-DQA1 and HLA-DQB1 Alleles in Type 2 Diabetes Mellitus and Diabetic Nephropathy in the Han Ethnicity of China.

HLA gene system is one of the most polymorphic regions of the human genome. The association of HLA class II genes in T1DM pathogenesis has been reported for several ethnicities. Associations of HLA class II genes with T2DM have revealed inconsistent results. Moreover, correlations between DN and HLA alleles remain unclear. We carried out DNA typing chip by specific medium resolution typing probes in 310 T2DM subjects (including 210 patients with DN and 100 patients without DN) in addition to 100 healthy controls. Differences were found between patients with T2DM and the control group in the frequencies of the HLA-DQA1∗0301 (15.5% versus 8.0%, P < 0.01) and the HLA-DQA1∗0501 alleles (16.6% versus 8.5%, P < 0.01). Differences were found between patients with DN and without DN in the frequencies of the HLA-DQA1∗0302 (6.9% versus 13.5%, P < 0.01) and HLA-DQB1∗0501 alleles (5.8% versus 14.5%, P < 0.01). Diabetes duration and systolic blood pressure were independent risk factors associated with DN (OR = 2.277 and 1.366, resp., P < 0.05), whereas the HLA-DQB1∗0501 llele had a protective effect on DN (OR = 0.53, P < 0.05). These data suggest the HLA-DQA1∗0301 and HLA-DQA1∗0501 alleles are markers of susceptibility for T2DM, and the HLA-DQB1∗0501 allele is associated with a protective effect on DN in Han ethnicity of China.