Dataset Information

TCF7L2 regulates pancreatic ?-cell function through PI3K/AKT signal pathway.

ABSTRACT: Background:Transcription factor 7-like 2 (TCF7L2), which previously known as TCF-4, is a major form of transcription factor involved in the downstream WNT signaling and exhibits the strongest association to diabetes susceptibility. Although we still do not know mechanistically how TCF7L2 exerts its physiological functions on pancreatic endocrine cells, it had been suggested that TCF7L2 may directly affect ?-cell function by regulating the activation of PI3K/AKT signaling pathway. Methods:MIN6 cells were transfected with TCF7L2 knockdown virus or lenti-TCF7L2 virus for 48 h to evaluate the contribution of TCF7L2 to the PI3K/AKT signaling pathway and pancreatic ?-cell function. This was confirmed by measuring the expression of PI3K p85 and p-Akt by western blotting and insulin secretion by enzyme-linked immunosorbent assay (ELISA), respectively. Chromatin immunoprecipitation (ChIP) and polymerase chain reaction (PCR) experiments were performed to explore the genomic distribution of TCF7L2-binding sites in the promoter of PIK3R1, the affinity between which was analyzed by the luciferase reporter assay. Results:In the present study, we strikingly identified that TCF7L2 could profoundly inhibit the expression of PIK3R1 gene and its encoding protein PI3K p85, which then could lead to the activation of PI3K/AKT signaling and stimulate insulin secretion in pancreatic ?-cells. However, the integrity and stability of evolutionarily conserved TCF7L2-binding motif plays a very crucial role in the binding events between transcription factor TCF7L2 and its candidate target genes. We also found that the affinity of TCF7L2 to the promoter region of PIK3R1 alters upon the specific binding sites, which further provides statistical validation to the necessity of TCF7L2-binding motif. Conclusions:This study demonstrated that TCF7L2 is closely bound to the specific binding regions of PIK3R1 promoter and prominently controls the transcription of its encoding protein p85, which further affects the activation of PI3K/AKT signaling pathway and insulin secretion.

SUBMITTER: Wu HH

PROVIDER: S-EPMC6612183 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

TCF7L2 regulates pancreatic β-cell function through PI3K/AKT signal pathway.

Wu Hui-Hui HH Li Yan-Liang YL Liu Nai-Jia NJ Yang Zhen Z Tao Xiao-Ming XM Du Yan-Ping YP Wang Xuan-Chun XC Lu Bin B Zhang Zhao-Yun ZY Hu Ren-Ming RM Wen Jie J

Diabetology & metabolic syndrome 20190705

<h4>Background</h4>Transcription factor 7-like 2 (TCF7L2), which previously known as TCF-4, is a major form of transcription factor involved in the downstream WNT signaling and exhibits the strongest association to diabetes susceptibility. Although we still do not know mechanistically how TCF7L2 exerts its physiological functions on pancreatic endocrine cells, it had been suggested that TCF7L2 may directly affect β-cell function by regulating the activation of PI3K/AKT signaling pathway.<h4>Meth ...[more]

PMID: 31312258

Similar Datasets

Project description:Background: Maspin (SERPINB5) is a potential tumor suppressor gene with pleiotropic biological activities, including regulation of cell proliferation, death, adhesion, migration and gene expression. Several studies indicate that nuclear localization is essential for maspin tumor suppression activity. We have previously shown that the EGFR activation leads to maspin nuclear localization in MCF-10A cells. The present study investigated which EGFR downstream signaling molecules are involved in maspin nuclear localization and explored a possible role of cell-cell contact in this process. Methods: MCF-10A cells were treated with pharmacological inhibitors against EGFR downstream pathways followed by EGF treatment. Maspin subcellular localization was determined by immunofluorescence. To investigate the role of cell-cell contact these cells were either treated with chelating agents or plated on different cell densities. Maspin and E-cadherin subcellular localization was determined by immunofluorescence. In addition, proteomic and interactome analyses were conducted in order to identify molecular partners which interact with maspin in EGF-treated cells only. Results: EGFR activation regulates cell behavior via de extracellular signal–related kinase (ERK)/MAP kinase, phosphatidyl-inositol-3 (PI 3) kinase- AKT and Jak-STAT pathways. Using pharmacological inhibitors against key components of these signaling pathways we found that PI3K-AKT and Jak-STAT, but not MAP kinase pathway, regulate EGF-induced maspin nuclear accumulation in MCF-10A cells. Interestingly, we observed that maspin is predominantly nuclear in sparse cell culture, but it is redistributed to the cytoplasm in confluent cells even in the presence of EGF. Proteomic and interactome results suggest a role of maspin on post-transcriptional and translation regulation, protein folding and cell-cell adhesion.Conclusions: Maspin nuclear accumulation is determined by an interplay between EGFR (via PI3K-AKT and Jak-STAT pathways) and cell-to-cell contact.

Dataset Information

TCF7L2 regulates pancreatic ?-cell function through PI3K/AKT signal pathway.

Publications

TCF7L2 regulates pancreatic β-cell function through PI3K/AKT signal pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure