RESUMO
OBJECTIVE: To investigate the role of microRNA-15b in diabetic retinopathy and its underlying mechanism. MATERIALS AND METHODS: Diabetes rat model was established by streptozotocin injection. The mRNA expression of microRNA-15b in retinal capillary endothelial cells and pericytes of diabetic rats was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The mRNA and protein expressions of vascular endothelial growth factor A (VEGFA) were detected by qRT-PCR and Western blot, respectively. MicroRNA-15b mimics or inhibitor were transfected into retinal capillary endothelial cells and pericytes of diabetic rats, respectively. The mRNA expressions of microRNA-15b and VEGFA were detected by qRT-PCR. Cell counting kit-8 (CCK-8) assay was used to detect the proliferation of capillary endothelial cells and pericytes. Dual-Luciferase reporter gene assay was conducted to verify the binding condition of microRNA-15b and VEGFA. RNA immunoprecipitation (RIP) assay was performed to determine whether microRNA-15b could bind to AGO2. Rescue experiments were finally carried out by detecting the proliferation of retinal capillary endothelial cells and pericytes after downregulation or overexpression of microRNA-15b and VEGFA. RESULTS: The expression of microRNA-15b decreased, whereas VEGFA expression increased in retinal capillary endothelial cells and pericytes of diabetic rats. High expression of microRNA-15b in retinal capillary endothelial cells and pericytes resulted in VEGFA down-regulation and decreased proliferation. RIP assay results indicated that microRNA-15b could interact with AGO2. Additionally, Dual-Luciferase reporter gene assay showed that VEGFA is a direct target gene of microRNA-15b. VEGFA overexpression could reverse the inhibited proliferation of retinal capillary endothelial cells and pericytes induced by microRNA-15b overexpression. Similarly, VEGFA knockdown could reverse the effect of the low expression of microRNA-15b on the proliferation of retinal capillary endothelial cells and pericytes. CONCLUSIONS: Low expression of microRNA-15b in retinal capillary endothelial cells and pericytes of diabetic rats promotes the development of diabetic retinopathy by up-regulating VEGFA.
Assuntos
Diabetes Mellitus Experimental/complicações , Retinopatia Diabética/genética , MicroRNAs/genética , Pericitos/citologia , Vasos Retinianos/citologia , Fator A de Crescimento do Endotélio Vascular/genética , Animais , Proliferação de Células , Células Cultivadas , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Retinopatia Diabética/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Células Endoteliais/química , Células Endoteliais/citologia , Pericitos/química , Ratos , Vasos Retinianos/química , Estreptozocina , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
OBJECTIVE: Long non-coding RNAs are an emerging special class of regulatory RNAs with more than 200 nucleotides that play vital roles in gene regulation, metabolism, drug resistance, cell differentiation, and other processes. These RNAs were also reported to be dysregulated in human disease, especially malignant tumors. However, the underlying mechanisms remain elusive. HOXD cluster antisense RNA 1 (HOXD-AS1), a recently discovered long non-coding RNA, is overexpressed in many cancers. We now review recent advances in understanding the function, role, regulation, and oncogenic properties of HOXD-AS1. MATERIALS AND METHODS: A systematic literature review in PubMed of HOXD-AS1 and cancer-related articles in English, published until June 2018, was conducted. RESULTS: The literature suggests that HOXD-AS1 is an oncogene that regulates diverse physiological and cellular processes such as proliferation, apoptosis, migration, invasion, metastasis, chemoresistance, epithelial to mesenchymal transition, and stem cell formation by interacting with various regulatory proteins and sequestering several microRNAs such as miR-608, miR-130a, and miR-217. CONCLUSIONS: HOXD-AS1 may be a prognostic biomarker and potential therapeutic target for various tumor diagnosis and treatment.
Assuntos
Carcinogênese/metabolismo , Regulação Neoplásica da Expressão Gênica , Oncogenes/fisiologia , RNA Longo não Codificante/biossíntese , Animais , Apoptose/fisiologia , Carcinogênese/genética , Linhagem Celular Tumoral , Proliferação de Células , Transição Epitelial-Mesenquimal/fisiologia , Humanos , RNA Longo não Codificante/genéticaRESUMO
Pregnancy in cattle and sheep can be diagnosed by the presence of a conceptus-derived antigen in maternal serum that is secreted by trophoblast and placental tissue primarily as an acidic component of Mr 67,000. Molecular cloning of its cDNA reveals that the antigen belongs to the aspartic proteinase family and has greater than 50% amino acid sequence identity to pepsin, cathepsin D, and cathepsin E. The inferred sequences of the ovine and bovine polypeptides show approximately 73% identity to each other. Critical amino acid substitutions at the active site regions suggest that both proteins are enzymatically inactive. The antigen is a product of trophoblast binucleate cells that invade maternal endometrium at implantation sites.