Overexpression of chicken Klf2 promotes klf7 transcription and inhibits adipocyte differentiation / 生物工程学报

Overexpression of Krüppel like factor 2 (Klf2) or Klf7 inhibits adipocyte formation. However, it remains unclear whether Klf2 regulates klf7 expression in adipose tissue. In this study, oil red O staining and Western blotting were employed to study the effect of Klf2 overexpression on the differentiation of chicken preadipocytes. The results showed that Klf2 overexpression inhibited the differentiation of chicken preadipocytes induced by oleate and the expression of pparγ, while promoted klf7 expression in chicken preadipocytes. Spearman correlation analysis was used to study the correlation between the expression data of klf2 and klf7 in the adipose tissue of both human and chicken. The results showed that there was a significantly positive correlation between the expression of klf2 and klf7 in adipose tissues (r > 0.1). Luciferase reporter assay showed that overexpression of Klf2 significantly promoted the activity of chicken klf7 promoter (-241/-91, -521/-91, -1 845/-91, -2 286/-91, -1 215/-91; P < 0.05). In addition, the activity of klf7 promoter (-241/-91) reporter in chicken preadipocytes was significantly positively correlated with the amount of klf2 overexpression plasmid transfected (Tau=0.917 66, P=1.074×10-7). Moreover, Klf2 overexpression significantly promoted the mRNA expression of klf7 in chicken preadipocytes (P < 0.05). In conclusion, upregulation of klf7 expression might be one of the pathways that Klf2 inhibits chicken adipocyte differentiation, and the sequence from -241 bp to -91 bp upstream chicken klf7 translation start site might mediate the regulation of Klf2 on klf7 transcription.

KLF9 regulates hepatic lipid metabolism via inducing CD36 expression / 生理学报

The development of nonalcoholic fatty liver disease (NAFLD) is closely related to the fatty acid (FA) uptake. This study aimed to investigate the effect of Krüppel-like factor 9 (KLF9) on CD36 (typical fatty acid translocase), hepatocellular lipid metabolism as well as the development and progression of nonalcoholic fatty liver. High-fat diet-induced obese C57BL/6J mice and db/db mice were used to test the expression levels of Klf9 and Cd36 in the livers. The primary hepatocytes were isolated from C57BL/6J mice, treated with Ad-GFP, Ad-Klf9, Ad-shCtrl or Ad-shKlf9, and then incubated with oleic acid and palmitic acid for 24 h. Liver-specific knockout of Klf9 mice were established. The protein levels and relative mRNA levels were examined by Western blot and real-time PCR, respectively. Triglyceride content was determined by using an assay kit. Lipid content was determined by Oil Red O staining. The results showed that: (1) Klf9 expression levels were increased in the livers of high-fat diet-induced obese mice and db/db mice, compared to their respective control mice. (2) Adenovirus-mediated overexpression of Klf9 in primary hepatocytes increased Cd36 expression and cellular triglyceride contents. (3) In contrast, adenovirus-mediated knockdown of Klf9 expression in primary hepatocytes by Ad-shKlf9 decreased Cd36 expression and cellular triglyceride contents. (4) Finally, Klf9 deficiency decreased liver Cd36 expression and alleviated fatty liver phenotype of high-fat diet-induced obese mice. These results suggest that KLF9 can regulate hepatic lipid metabolism and development of NAFLD by promoting the expression of CD36.

Papel de KLF6, como factor de predicción precoz en cáncer colorrectal humano / Role of KLF6 as early predictor in human colorectal cancer

El cáncer colorrectal (CCR) constituye el segundo tipo de cáncer más frecuente en la población europea. Actualmente no existe biomarcadores moleculares que se pueden utilizar para la detección temprana del cáncer de CCR. KLF6 es un supresor tumoral relacionado con varios tipos de cánceres. Nuestra hipótesis plantea que KLF6 puede ser un excelente marcador en el diagnóstico precoz de CCR. Para estudiar la implicancia de KLF6 en el CCR, se seleccionaron 15 biopsias de cada estadio (T1,T2 y T3) de los archivos del Servicio de Anatomía Patológica del Hospital Central de la Defensa Gómez-Ulla, las cuales presentaban áreas de tejido afectado (tumor) y áreas sin afectación (no tumorales). Para ello se realizó un estudio histológico, inmunohistoquímico y RT-PCR, basada en la expresión de 3 genes, Ki67 y p53 como marcadores positivos y KLF6 como marcador en estudio. Los resultados mostraron que la expresión de KLF6 está directamente relacionada con el aumento de la malignidad celular en los adenocarcinomas, corroboradas por las RT-PCR, observándose la aparición progresiva de formas de procesado alternativo, no correspondiente a KLF6. Esta proteína, se expresó tanto a nivel citoplasmático como nuclear en los primeros estadios T1 y T2, para desaparecer a nivel nuclear en el estadio más avanzado (T3). Concluimos que KLF6 es un buen marcador tumoral de CCR, debido a que muestra patrones crecientes de expresión a nivel citoplasmático y decrecientes a nivel nuclear...

Colorectal cancer (CRC) is the second most common type of cancer in the European population. Currently there molecular biomarkers that can be used for early detection of cancer of CRC. Is a tumor suppressor KLF6 associated with several types of cancers. Our hypothesis is that KLF6 can be an excellent marker for the early diagnosis of CRC. To study the implication of KLF6 in CRC, we selected 15 biopsies of each stage (T1, T2 and T3) from the archives of the Pathology Department of Defense Central Hospital Gómez-Ulla, which had areas of affected tissue (tumor) and unaffected areas (non-tumor). This study was performed histological, immunohistochemical and RT-PCR, based on the expression of three genes, markers Ki67 and p53 as positive and as a marker in KLF6 study. The results showed that the expression of KLF6 is directly related to increased malignancy cell adenocarcinomas, corroborated by RT-PCR, showing the gradual emergence of alternative forms processing, corresponding to no KLF6. This protein was expressed both cytoplasmic and nuclear in the early stages T1 and T2, disappearing at the nuclear level in the most advanced stage (T3). KLF6 conclude that a good CRC tumor marker because it shows patterns of expression level increased cytoplasmic and nuclear level decreasing...