Research progress in effects of microRNA -15a and microRNA -16 on fibrotic diseases / 中南大学学报(医学版)

MicroRNA (miR) is a class of highly conserved non-coding single-stranded RNA widely existing in mammals, which can negatively regulate the expression of targeting genes after transcription. As a key regulator, miR negatively regulates the expression of the targeting genes and disrupts important molecular signaling pathways, leading to the imbalance of multiple pathways such as tissue repair and inflammation involved in the fibrotic process. Among them, miR-15a/16 can participate in regulating and controlling the fibrotic process of various organs, including liver, lung, heart, kidney and other fibrotic diseases by acting on cell proliferation and transformation, extracellular matrix proteins production and degradation, inflammation and other important cell functions. It has potential diagnostic and therapeutic value. Clarifying the biological function of miR-15a/16 and its mechanism for action and therapeutic application prospects in various fibrotic lesions are of great significance for the molecular targeted treatment of fibrotic diseases.

Expression of intronic miRNAs and their host gene Igf2 in a murine unilateral ureteral obstruction model

The objective of this study was to determine the expression of miR-483 and miR-483* and the relationship among them, their host gene (Igf2), and other cytokines in a murine model of renal fibrosis. The extent of renal fibrosis was visualized using Masson staining, and fibrosis was scored 3 days and 1 and 2 weeks after unilateral ureteral obstruction (UUO). Expression of miR-483, miR-483* and various cytokine mRNAs was detected by real-time polymerase chain reaction (PCR). Expression of miR-483 and miR-483* was significantly upregulated in the UUO model, particularly miR-483 expression was the greatest 2 weeks after surgery. Additionally, miR-483 and miR-483* expression negatively correlated with Bmp7 expression and positively correlated with Igf2, Tgfβ, Hgf, and Ctgf expression, as determined by Pearson's correlation analysis. Hgf expression significantly increased at 1 and 2 weeks after the surgery compared to the control group. This study showed that miR-483 and miR-483* expression was upregulated in a murine UUO model. These data suggest that miR-483 and miR-483* play a role in renal fibrosis and that miR-483* may interact with miR-483 in renal fibrosis. Thus, these miRNAs may play a role in the pathogenesis of renal fibrosis and coexpression of their host gene Igf2.

Superoxide overproduction and kidney fibrosis: a new animal model / Produção aumentada de superóxido e fibrose renal: novo modelo animal

Objective To establish whether the mutation in the Immp2L gene induces renal fibrosis and whether aging exacerbates renal morphology in mice. Methods Female mutant mice with mutation in the inner mitochondrial membrane peptidase 2-like protein at 3 and 18 months of age were used. Renal fibrosis was analyzed using classic fibrosis score, Masson’s trichrome staining, and analysis of profibrotic markers using real time polymerase chain reaction (superoxide dismutase 1, metalloproteinase-9, erythropoietin, transforming growth factor beta), and immunostaining (fibroblasts and Type IV collagen). Oxidative stress markers were determined by immunohistochemistry. The number of renal apoptotic cells was determined. Renal function was estimated by serum creatinine. Results Young mutant mice had significantly more glomerulosclerosis than age-matched mice (p=0.034). Mutant mice had more tubular casts (p=0.025), collagen deposition (p=0.019), and collagen type IV expression (p<0.001). Superoxide dismutase 1 expression was significantly higher in young mutants (p=0.038). Old mutants exhibited significantly higher expression of the fibroblast marker and macrophage marker (p=0.007 and p=0.012, respectively). The real time polymerase chain reaction of metalloproteinase-9 and erythropoietin were enhanced 2.5- and 6-fold, respectively, in old mutants. Serum creatinine was significantly higher in old mutants (p<0.001). Conclusion This mutation altered renal architecture by increasing the deposition of extracellular matrix, oxidative stress, and inflammation, suggesting a protective role of Immp2L against renal fibrosis. .

Objetivo Estabelecer se a mutação no gene Immp2L induz à fibrose renal e se o envelhecimento exacerba a morfologia renal em camundongos. Métodos Foram usadas fêmeas de camundongos mutantes para proteína semelhante à peptidase 2 da camada interna da mitocôndria, com 3 e 18 meses de idade. Para analisar a fibrose renal, foram usados o escore clássico de fibrose, a coloração com tricrômio de Masson, e a análise de marcadores profibróticos, por meio da reação em cadeia de polimerase em tempo real (superóxido dismutase 1, metalonoproteinase-9, eritropoietina e fator transformador de crescimento beta), e a imunocoloração (fibroblastos e colágeno IV). Marcadores de estresse oxidativo foram determinados por imuno-histoquímica. O número de células apoptóticas renais foi analisado. A função renal foi estimada por creatinina sérica. Resultados Camundongos mutantes jovens apresentaram glomeruloesclerose em quantidade significativamente maior que animais da mesma idade (p=0,034). Os mutantes mostraram maior formação de cilindros tubulares (p=0,025), deposição de colágeno (p=0,019) e maior expressão de colágeno do tipo IV (p<0,001). A expressão de superóxido dismutase 1 foi maior em mutantes jovens (p=0,038). Mutantes idosas exibiram maior expressão dos marcadores de fibroblastos e macrófagos (p=0,007 e p=0,012, respectivamente). As reações da cadeia de polimerase em tempo real da metalanoproteinase-9 e da eritropoietina estavam aumentadas em 2,5 e 6 vezes, respectivamente, em mutantes idosas. A creatinina sérica foi significantemente maior em animais idosos mutantes (p<0,001). Conclusão Essa mutação alterou a arquitetura renal pelo aumento da deposição de matriz extracelular, estresse oxidativo e inflamação, sugerindo papel de proteção de Immp2L contra a fibrose renal. .

Asociación entre polimorfismos en los genes PNPLA3 y TM6SF2 y presencia de fibrosis en pacientes con infección crónica por virus hepatitis C / The association between polymorphisms in the genes PNPLA3 and TM6SF2 and the presence of fibrosis in patients with chronic hepatitis C virus infection

Hepatitis C virus (HCV) is a globally prevalent pathogen and a leading cause of death and morbidity. The most recent estimates of disease burden show an increase in seroprevalence over the last 15 years to 2.8 percent, equating to >185 million infections worldwide. Persistent hepatitis C infection is associated with the development of liver cirrhosis, hepatocellular cancer, liver failure and death. The magnitude of disease progression in chronic infection varies significantly among individuals. Several factors have been recognized as being associated with the progression of HCV-related liver fibrosis and with clinical outcomes. As liver fibrosis progression remains variable between individuals with similar environmental or virological risks, host genetic predispositions have been suggested as another critical determinant. The single nucleotide polymorphisms in Patatin-like phospholipase domain-containing 3 (PNPLA3) and Transmembrane 6 Superfamily Member 2 (TM6SF2) genes are genetic determinants of nonalcoholic fatty liver disease, in terms of inflammation and fibrosis. The possible action of the PNPLA3 and TM6SF2 polymorphisms on fibrosis development in chronic hepatis C is being studied, with controversial results.

El aumento de la expresión del ARNm de la enzima convertidora de angiotensina I homóloga (ECA-2) inducido por atorvastatina se asocia a menor fibrosis e hipertrofia ventricular izquierda en un modelo de cardiomiopatía diabética / Atorvastatin induced increase in homologous angiotensin i converting enzyme (ACE2) mRNA is associated to decreased fibrosis and decreased left ventricular hypertrophy in a rat model of diabetic cardiomyopathy

Objetivos. Evaluar el efecto de atorvastatina sobre la progresión del remodelado cardiaco y la expresión de ECA-2 en el miocardio de ratas diabéticas. Materiales y métodos. La diabetes fue inducida en ratas Holtzman con una inyección intraperitoneal de estreptozotocina. Los animales fueron divididos en tres grupos: (1) ratas control, (2) ratas diabéticas y (3) ratas diabéticas tratadas con atorvastatina (50 mg/kg/día). Después de ocho semanas de tratamiento, los corazones fueron extraídos para el análisis morfométrico, la cuantificación de colágeno y la determinación de los niveles de ARNm de ECA y ECA-2. Resultados. El índice de hipertrofia ventricular y el depósito de colágeno se incrementaron significativamente en las ratas diabéticas. La administración de atorvastatina previno estos cambios sin modificar los niveles de colesterol. La hiperglicemia produjo un incremento significativo en los niveles del ARNm de ECA y una marcada disminución en la expresión de ECA-2 en el miocardio de ratas diabéticas. La administración de atorvastatina indujo la expresión del ARNm de ECA-2 e inhibió la sobreexpresión del ARNm de ECA en el miocardio de las ratas diabéticas. Conclusiones. Nuestros resultados indican que la atorvastatina, independientemente de su capacidad para disminuir el colesterol, normaliza la relación de la expresión de ECA/ECA-2 y atenúa el desarrollo del remodelado adverso en el corazón diabético.

Objectives. This study has investigated the effect of atorvastatin on the progression of cardiac remodelling and ACE- 2 expression in diabetic myocardium in rats. Materials and Methods. Diabetes was induced in Holtzman rats with an intraperitoneal injection of streptozotocin. The animals were divided into 3 groups: (1) normal control rats, (2) diabetic rats and (3) diabetic rats treated orally with atorvastatin (50 mg/kg/day). After eight weeks of treatment, the hearts were removed for morphometric studies, collagen content assay and genetic expressions of ACE and ACE2 mRNA. Results. Myocardial hypertrophy index and collagen deposition were increased in diabetic rats, but not in the treated-diabetic rats, without producing changes in cholesterol levels. Myocardial ACE mRNA levels were increased while ACE2 mRNA levels were decreased in diabetic rats. Atorvastatin administration attenuated overexpression of ACE mRNA and overexpression of ACE-2 mRNA in diabetic rats. Conclusions. Our results indicate that atorvastatin, independently of its cholesterol-lowering capacity, lowers the ACE/ACE2 ratio to normal values and attenuates the development of adverse remodeling in the diabetic heart.