RESUMO
The purpose of this study was to explore the functional implication of microRNA-218 (miR-218) in diabetic nephropathy (DN) through high-glucose-stimulated renal proximal tubule impairment. Biological function experiments showed that miR-218 and inflammatory factors TNF-α and IL-1ß were highly expressed in renal proximal tubule under high-glucose conditions. Inhibiting miR-218 alleviated renal tubular cell injury, which was represented by miR-218 inhibitor facilitating renal tubular cell vitality whilst reducing its apoptosis and levels of inflammation factors. In addition, we confirmed that miR-218 directly targeted GPRC5A and negatively regulated its expression. Co-transfection assay showed that overexpression of GPRC5A accentuated the mitigated action of miR-218 inhibitor on renal proximal tubule cell injury induced by high-glucose. Accordingly, these data indicated that downregulation of miR-218 can assuage high-glucose-resulted renal tubular cell damage, and its ameliorative effect was achieved by negative regulation of GPRC5A, which provides a novel direction for unearthing the pathogenesis and even further biological treatment of DN.
Assuntos
Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/complicações , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/metabolismo , Regulação para Baixo/genética , Glucose/efeitos adversos , Túbulos Renais/lesões , MicroRNAs/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Células Cultivadas , Nefropatias Diabéticas/urina , Humanos , Interleucina-1beta/metabolismo , Túbulos Renais/citologia , MicroRNAs/genética , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transfecção , Fator de Necrose Tumoral alfa/metabolismoRESUMO
OBJECTIVE: To investigate the feasibility of monitoring therapeutic effect of adenovirus vector containing IL12-IRES-CKb gene on a rabbit VX2 liver tumor model by using phosphorous-31 magnetic resonance spectroscopy (31P MRS). METHODS: A total of 18 healthy New Zealand White rabbits were used to generate animal models by implanting VX2 tumor chips into livers through laparotomy. Tumor-bearing animals were randomly divided into three groups and were injected with AdCMVIL12-IRES-CKb, AdCMV-Empty and saline respectively via ear veins. 31P MRS scan was performed after animals were fed with creatine solution for five days. Animals were euthanized thereafter and tumors were removed for pathological examination, immunohistochemistry (IHC) staining and protein analysis (Western blot). RESULTS: The intrahepatic and seral expressions of creatine kinase (CKb) and IL-12 were detected only in AdCMVIL12-IRES-CKb group. Tumor diameters pre- and post- treatment in three groups were 1.63+/-0.04 vs 1.62+/-0.03 in AdCMVIL12-IRES-CKb group (P = 0.229), 1.59+/-0.05 vs 1.84+/-0.11 in AdCMV-Empty group (P = 0.003) and 1.60+/-0.02 vs 2.07+/-0.12 in saline group (P = 0.001), respectively. Pcr Changes between pre- and post- treatment among the three groups were compared (F = 6.235, P value is less than 0.05). PCr increased significantly in AdCMVIL12-IRES-CKb group as compared to AdCMV-Empty (P = 0.004) and saline group (P = 0.049), whereas no change found between AdCMV-Empty and saline group (P = 0.153). CONCLUSION: 31P MRS, an effective and non-invasive functional imaging method, can be used to monitor the therapeutic effect of adenovirus vector containing IL12-IRES-CKb gene on rabbit VX2 liver tumor model through detecting metabolic product of imaging reporter gene CKb (pCr).
