RESUMO
BACKGROUND: Tubular injury is considered as a crucial pathological feature of diabetic nephropathy. LncRNA MALAT1 is involved in diabetic complications. Hence the role of MALAT1 in high glucose-induced renal tubular epithelial cells (HK-2) injury deserves investigation. METHODS: The diabetic mice model was established with streptozotocin (STZ) injection. The expression of NEAT1, SIRT1, and Foxo1 mRNA and protein was determined with qRT-PCR and western blot, respectively. The serum creatinine and urinary albumin were examined by enzyme linked immunosorbent assay (ELISA). Interaction between MALAT1 and Foxo1 was detected with RIP and RNA pull-down assay, respectively. Dual luciferase reporter assay was used to evaluate the binding between Foxo1 and SIRT1. RESULTS: LncRNA MALAT1 was up-regulated in kidney tissues of diabetic mice and in HK-2â¯cells treated with high glucose, while the expression of SIRT1 was decreased. Interaction between MALAT1 and Foxo1 was observed in HK-2â¯cells and the interaction was promoted by high glucose treatment. Foxo1 activated SIRT1 transcription by binding to its promoter, and MALAT1 repressed SIRT1 expression through targeting Foxo1. CONCLUSION: LncRNA MALAT1 interacts with transcription factor Foxo1 to represses SIRT1 transcription in high glucose incubated HK-2â¯cells, which promotes high glucose-induced HK-2â¯cells injury.
Assuntos
Células Epiteliais/efeitos dos fármacos , Proteína Forkhead Box O1/genética , Regulação da Expressão Gênica , Glucose/farmacologia , RNA Longo não Codificante/genética , Sirtuína 1/genética , Animais , Linhagem Celular , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Células Epiteliais/metabolismo , Proteína Forkhead Box O1/metabolismo , Humanos , Túbulos Renais Proximais/citologia , Masculino , Camundongos Endogâmicos C57BL , Ligação Proteica/efeitos dos fármacos , RNA Longo não Codificante/metabolismo , Sirtuína 1/metabolismoRESUMO
OBJECTIVE: Diabetic nephropathy (DN) is a serious complication that commonly confronted by diabetic patients. A common theory for the pathogenesis of this renal dysfunction in diabetes is cell injury, inflammation as well as oxidative stress. In this content, the detailed molecular mechanism underlying high glucose induced renal tubular epithelial injury was elaborated. METHODS: An in vivo rat model of diabetes by injecting streptozotocin (STZ) and an in vitro high glucose incubated renal tubular epithelial cell (HK-2) model were used. Expression levels of Keap1, nuclear Nrf2 and p65 were determined by western blotting. Level of microR-29 (miR-29) was assessed using quantitative RT-PCR. Combination of p65 and miR-29 promotor was assessed using chromatin immunoprecipitation. Keap1 3'-UTR activity was detected using luciferase reporter gene assay. Cell viability was determined using MTT assay. RESULTS: In diabetic rat, miR-29 was downregulated and its expression is negatively correlated with both of serum creatinine and creatinine clearance. In high glucose incubated HK-2 cell, deacetylases activity of Sirt1 was attenuated that leads to decreased activity of nuclear factor kappa B (NF-κB). NF-κB was demonstrated to regulate miR-29 expression by directly binding to its promotor. The data of luciferase assay showed that miR-29 directly targets to Keap1 mRNA. While high glucose induced down regulation of miR-29 contributed to enhancement of Keap1 expression that finally reduced Nrf2 content by ubiquitinating Nrf2. Additionally, overexpression of miR-29 effectively relieved high glucose-reduced cell viability. CONCLUSION: High glucose induces renal tubular epithelial injury via Sirt1/NF-κB/microR-29/Keap1 signal pathway.
Assuntos
Células Epiteliais/metabolismo , Glucose/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Túbulos Renais/patologia , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Sirtuína 1/metabolismo , Regiões 3' não Traduzidas , Animais , Sobrevivência Celular , Imunoprecipitação da Cromatina , Creatinina/sangue , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Nefropatias Diabéticas/metabolismo , Modelos Animais de Doenças , Proteína 1 Associada a ECH Semelhante a Kelch , Túbulos Renais/citologia , Masculino , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais , UbiquitinaçãoRESUMO
Photodynamic therapy (PDT) started in the People's Republic of China in the early 1980s after hematoporphyrin derivative (HpD) was used in China as PDT photosensitizer in clinical PDT for the treatment of various cancers. Since then, numerous domestic photosensitizers have been synthesized and evaluated. In general, the research and development of PDT photosensitizers in China can be divided into two stages. Firstly, attention was focused on the development of mixed porphyrin preparations similar to HpD and Photofrin II, and the second stage was searching for new photosensitizers with definite structures. In the past 2 decades three mixed porphyrin preparations and a series of new photosensitizers with different structures were developed and entered into formal clinical trials in China. This manuscript will introduce past research and development activities in China and present published preclinical and clinical data of some promising photosensitizers.