Project description:STIM1 is a Ca2+ sensor of intracellular Ca2+ stores and essentially activates the Ca2+ entry channels of the plasma membrane. STIM1 is predicted to activate transient receptor potential canonical (TRPC) channels and Orai channels, and has a critical role in promoting the development of cardiac hypertrophy. Gene array experiments were performed to analyze the effects of STIM1 deficiency using total RNA from the left ventricles of WT sham, WT TAC, STIM1KO sham and STIM1KO TAC 4 weeks after the operation.
Project description:PGC1b transgenic mice were generated to selectively over-express PGC1b in skeletal muscles using human skeletal alpha-actin gene promoter. The gene expression profiles were collected from Tibialis anterior (TA) muscles of wild type (WT) and PGC1b transgenic (TG) mice. Tibialis anterior muscles from three month old WT and PGC1b transgenic male mice.
Project description:STIM1 is an endoplasmic reticulum (ER) calcium (Ca2+) sensor that serves to replenish ER Ca2+ stores in response to ER Ca2+ depletion through gating of plasmalemmal Orai1 channels in a process known as store operated calcium entry (SOCE). Previously, we have shown that SOCE is impaired in the diabetic pancreatic β cell; however, the consequences of reduced β cell SOCE have not been well studied. To test this, we generated mice with pancreatic β cell specific deletion of STIM1 (STIM1Δβ). Our results revealed a striking sexual dimorphism in metabolic phenotypes when STIM1Δβ mice were challenged with high fat diet for 8 weeks. Male STIM1Δβ mice showed no differences in total weight, lean or fat mass, or glucose tolerance compared to WT littermate controls. In contrast, female STIM1Δβ mice displayed significantly increased total body weight, fat mass, and reduced glucose tolerance, in vivo glucose-stimulated insulin secretion and β cell mass compared to WT littermate controls, while insulin sensitivity, food intake, and energy expenditure were unchanged. To investigate mechanisms underlying these findings, RNA sequencing was performed in isolated islets and revealed altered 17-beta estradiol (E2) signaling, lipid metabolism, epithelial cell differentiation and decreased noncanonical estradiol receptor GPER. Consistent with this, alpha cell mass was increased in female STIM1Δβ, while proteomics and immunoblot analysis of STIM1 knockout (STIM1KO) INS-1 beta cells revealed reduce insulin expression and increased glucagon expression, suggesting STIM1 may be required for the maintenance of β cell identity. To this end, we show that a reduction of a noncanonical estradiol receptor GPER in STIM1 deficient islets contributes to the marked sexual dimorphism observed during beta cell dysfunction in female STIM1Δβ mice. This present study delineates a sexually dimorphic regulation of STIM1 in the maintenance of pancreatic beta cell identity through GPER and may expand the field of therapeutic approaches to diabetes. Our findings demonstrate the importance of STIM1 and GPER expression stability in the anti-diabetogenic response from estradiol.
Project description:The goal of this study is to characterize the genetic changes that occur in muscle of mice carrying a mutant allele for STIM1 (D84G)
Project description:To investigate the altered glucose and lipid metabolism genes after STIM1 knockout (STIM1 KO) or STIM1 knockout plus Snail1 OE (STIM1 KO+Snail1 OE) in SMMC7721 cells. STIM1 KO-SMMC7721 cells were constructed by CRISPR/Cas9, and STIM1 KO+Snail1 OE-SMMC7721 cells was established via lentiviral Infection of Snail1 overexpression in STIM1 KO-SMMC7721 cells. The cells mentioned above were cultured in DMEM supplemented with 10% (v/v) FBS at 37 °C in 5% CO2. When the cells grow to 60~70% confluent, total RNA was extracted by using Trizol (TAKARA, Japan). Reverse transcription was performed from 1μg total RNA using PrimeScript™ RT reagent Kit with gDNA Eraser (TAKARA), Quantitative real-time PCR were performed (CFX386, BioRad) with 40 cycles at 95 °C for 10 seconds, 59 °C for 20 seconds and 72 °C for 30 seconds.
Project description:DNA damage represents a challenge for cells as this damage must be eliminated to preserve cell viability and the transmission of genetic information. To reduce or eliminate unscheduled chemical modifications in genomic DNA, an extensive signaling network, known as the DNA damage response (DDR) pathway, ensures this repair. In this work, and by means of a proteomic analysis aimed at the study of the STIM1 protein interactome, we have found that STIM1 is closely related to the protection from endogenous DNA damage, replicative stress, as well as in the response to interstrand crosslinks (ICLs). Here we show that STIM1 has a nuclear localization signal (NLS) that mediates its translocation to the nucleus, and that this translocation and the association of STIM1 to chromatin is enhanced in response to mitomycin C (MMC), an ICL-inducing agent. Consequently, STIM1-deficient cell lines show a higher level of basal DNA damage, replicative stress, and a higher sensitivity to MMC. We show that STIM1 normalizes FANCD2 protein levels in the nucleus, explaining the increased sensitivity to MMC in STIM1-KO cells. Our results show for the first time a nuclear function for the endoplasmic reticulum protein STIM1 and increase the number of genes involved in DNA repair.
Project description:We report comprehensive miRNA expression profiles by miRNA-seq analysis in tibialis anterior muscle and serum of a disuse-induced atrophy model, compared with young (6 months) and old (24 months) mice.
Project description:Influence of STIM1 on the transcriptome of CD4+ T cell subsets STIM1 is critical for the regulation of the intracellular Ca2+ homeostasis in CD4+ T cell. Loss of function mutations in STIM1 in patients result in severe immuno deficiency and recurrent infections. Using conditional knock out mice for STIM1, we investigated the role of STIM1 in T cells during chronic infections by in-vivo and in-vitro experiments. We found that STIM1 is required for T cell-mediated immunity to chronic infection with Mycobacterium tuberculosis (Mtb) as STIM1-deficient mice succumb to infection faster than littermate controls, have increased mycobacterial burdens and severe pulmonary infiltration with myeloid and lymphoid cells .Using the Affymetrix Mouse Exon 1.0 platform, we analyzed the influence of STIM1 expression on the transcriptom of CD4+T cells in-vitro. We found that STIM1 is required for the regulation of apoptosis related genes after TCR stimulation as well as for the induction of a transcriptonal program that polarizes naive CD4+ T cells into inducible CD4+ T regulatory cells (iTreg). Together with our in-vivo findings, these experiments reveal that STIM1 is essential for immune regulation to prevent an injurious inflammatory response during chronic infection.
Project description:Utilizing glycerol intramuscular injections in M. musculus provide a models of skeletal muscle damage followed by skeletal muscle regeneration. In particular, glycerol-induced muscle injury triggers accute activation of skeletal muscle stem cells, called satellite cells. However, aging dramatically impairs the regenerative capacity of satellite cells. We characterized genome-wide expression profiles of young and old satellite cells in the non-proliferative and activated state, freshly isolated to non-injured or damaged muscles, respectively. Our goal was to uncover new regulatory signaling specific to satellite cells entry into the activation and myogenic program that are affected with age. Satellite cells were isolated in either quiescent / non-proliferative or activated state from uninjured or 3 days after glycerol-induced injury of tibialis anterior, gastrocnemius and quadriceps, respectively. Young (2-4 months old) and old (20-24 months old) wildtype C57BL/6J male were used, with five to six biological replicates per group.