RESUMEN
Renal interstitial fibrosis, a pathological feature of diabetic nephropathy, is closely related to endothelial-to-mesenchymal transition (EMT). This study aimed to explore the effect of H-1-2, a polysaccharide of Pseudostellaria heterophylla, on high glucose (HG) induced-podocyte EMT in vivo and ex vivo. DBA/2 mice were given five consecutive days of streptozotocin injection to induce the diabetic nephropathy model. H-1-2 treatment effectively attenuated general states (bodyweight and blood glucose level) and reduced oral glucose tolerance, insulin tolerance, kidney index, as well as the level of serum urine nitrogen, serum creatinine, and urinary albumin excretion rate in diabetic nephropathy mice. The injury and EMT of podocytes in diabetic nephropathy mice were restrained by H-1-2. After exposing podocytes to HG, the impaired cell viability, apoptosis, the downregulation of nephrin, synaptopodin, sirtuin 1 (SIRT1) and P-cadherin, and the upregulation of N-cadherin were observed in podocytes. H-1-2 treatment could reverse these effects induced by HG. To uncover the mechanism underlying H-1-2 suppressing EMT, small interference RNA for SIRT1 was transfected into podocytes. Mechanically, silencing SIRT1 largely restrained the protective effect of H-1-2 on HG-induced podocytes. In conclusion, H-1-2 exerts a potential role in alleviating HG-induced dysfunction and EMT of podocytes in vivo and ex vivo via SIRT1.
Asunto(s)
Nefropatías Diabéticas , Podocitos , Ratones , Animales , Podocitos/patología , Nefropatías Diabéticas/tratamiento farmacológico , Sirtuina 1/farmacología , Ratones Endogámicos DBA , Glucosa/toxicidad , Transición Epitelial-MesenquimalRESUMEN
OBJECTIVE: To study the effects of Qiwei Granule (QWG) on the protein and mRNA expressions of renal tissue transforming growth factor beta1 (TGF-beta1) in KK-Ay mice with spontaneous type 2 diabetes mellitus (T2DM). METHODS: Spontaneous T2DM KK-Ay mice model was adopted. Forty-five male mice were randomly divided into three groups, i. e., the model group, the Chinese medicine group, and the Western medicine group, 15 in each group. Fifteen male C57BL/6J mice were set up as the normal control group. The mice in the Chinese medicine group and the Western medicine group were administered intragastrically with QWG (at the daily dose of 20 g/kg) and valsartan (at the daily dose of 10 mg/kg), and the treatment lasted for 12 successive weeks. The pathological changes of the kidney were observed using HE staining, PAS, and Masson staining. The protein and mRNA expressions of TGF-beta1, were detected using immunohistochemical method and Real-time fluorescent quantitative PCR. RESULTS: The renal pathological changes of mice in the model group showed hypertrophic glomeruli, widened mesenteric matrix, increased mesangial cells, vacuolar renal tubular epithelial cells, tubular ectasia, and foci atrophy. Necrosis was occasionally seen. More protein cast, mesenchymal infiltration of inflammatory cells, and interstitial fibrosis could be seen. The protein and mRNA expressions of TGF-beta1 increased more in the model group than in the normal control group. After treatment by QWG and valsartan, the renal pathological changes were obviously alleviated, and the protein and mRNA expressions of TGF-beta1 were obviously lowered (P<0.05). CONCLUSION: By inhibiting the protein and mRNA expressions of TGF-beta1, QWG could play a role in preventing and curing diabetic nephropathy.
Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Medicamentos Herbarios Chinos/farmacología , Riñón/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Animales , Medicamentos Herbarios Chinos/uso terapéutico , Masculino , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/metabolismoRESUMEN
MicroRNAs (miRs) play important roles in initiation and progression of many pathologic processes. However, the roles of miRs in diabetic nephropathy remain unclear. This study was to determine whether miR-21 was involved in diabetic nephropathy and to explore the relationship between miR-21 and MMP9/TIMP1 expression in diabetic nephropathy. In situ hybridization studies showed that miR-21 was primarily localized and distributed in cortical glomerular and renal tubular cells in diabetic kk-ay kidney. Real-time quantitative RT-PCR demonstrated that the expression of miR-21 was significantly increased in kk-ay mice, compared with control C57BL mice. Interestingly, miR-21 expression positively correlated with urine albumin creatine ratio (ACR), TIMP1, collagen IV (ColIV), and fibronectin (FN); while negatively correlated with creatine clearance ratio (Ccr) and MMP-9 protein. Importantly, antagomir-21 not only ameliorated Ccr and ACR but also decreased TIMP1, ColIV, and FN proteins. In conclusion, our data demonstrate that miR-21 contributes to renal fibrosis by mediating MMP9/TIMP1 and that inhibition of miR-21 may be a novel target for diabetic nephropathy.
Asunto(s)
Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/patología , Riñón/patología , Metaloproteinasa 9 de la Matriz/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Albuminuria/complicaciones , Animales , Colágeno Tipo IV/metabolismo , Creatina/orina , Nefropatías Diabéticas/genética , Nefropatías Diabéticas/orina , Fibronectinas/metabolismo , Fibrosis/genética , Fibrosis/metabolismo , Regulación Enzimológica de la Expresión Génica , Masculino , Metaloproteinasa 9 de la Matriz/genética , Ratones , Ratones Endogámicos C57BL , Inhibidor Tisular de Metaloproteinasa-1/genéticaRESUMEN
Diabetic peripheral neuropathy (DPN) is a common microvascular complication of diabetes associated with high disability rate and low quality of life. Tang-Luo-Ning (TLN) is an effective traditional Chinese medicine for the treatment of DPN. To illustrate the underlying neural protection mechanisms of TLN, the effect of TLN on electrophysiology and sciatic nerve morphology was investigated in a model of streptozotocin-induced DPN, as well as the underlying mechanism. Sciatic motor nerve conduction velocity and digital sensory nerve conduction velocity were reduced in DPN and were significantly improved by TLN or α -lipoic acid at 10 and 20 weeks after streptozotocin injection. It was demonstrated that TLN intervention for 20 weeks significantly alleviated pathological injury as well as increased the phosphorylation of ErbB2, Erk, Bad (Ser112), and the mRNA expression of neuregulin 1 (Nrg1), GRB2-associated binding protein 1 (Gab1), and mammalian target of rapamycin (Mtor) in injured sciatic nerve. These novel therapeutic properties of TLN to promote Schwann cell survival may offer a promising alternative medicine for the patients to delay the progression of DPN. The underlying mechanism may be that TLN exerts neural protection effect after sciatic nerve injury through Nrg1/ErbB2âErk/Bad Schwann cell survival signaling pathway.