Project description:Dipeptidyl peptidase-4 (Dpp4) inhibitors are used worldwide to combat diabetes, however, their roles in cardiovascular disorders are yet to be defined. Here we show that a DPP4 inhibitor, linagliptin, contributes for the suppression of capillary rarefaction in cardiac tissues of dietary obese mice model. Imposing a high fat diet into mice induced capillary rarefaction and cardiac dysfunction. These pathologies associated with high DPP4 level in circulation, and the administration of linagliptin into dietary obese mice suppressed the development of capillary rarefaction and ameliorated cardiac dysfunction. Early growth response protein 1 (EGR1), known as an angiogenic transcription factor, is significantly reduced in the cardiac tissue upon metabolic stress, and this suppression was inhibited by the administration of linagliptin.
Project description:Effect of expression of dipeptidyl peptidase-IV (DPP-IV) in U373 cell line on uncontrolled cell proliferation and aberrant interactions with the brain extracellular matrix.
Project description:Tubulointerstitial injury plays an important role in diabetic nephropathy (DN) progression; however, no reliable urinary molecule has been used to predict tubulointerstitial injury and renal outcome of DN clinically. In this study, based on tubulointerstitial transcriptome, we identified secretory leukocyte peptidase inhibitor (SLPI) as the molecule associated with renal fibrosis and prognosis of DN. In tubular cells, high glucose could upregulate SLPI, which bound with β-catenin and GSK-3β reciprocally, abolished the interaction between β-catenin and GSK-3β, diminished GSK-3β-regulated β-catenin phosphorylation and the subsequent ubiquitination and degradation, thus led to β-catenin signaling activation and renal fibrosis. Db/db mice injected with adenovirus carrying Slpi-3xflag-GFP (Ad-Slpi-GFP) developed β-catenin signaling activation in the proximal tubule, worse albuminuria and tubulointerstitial fibrosis. Conversely, Slpi knockout (KO) mice with STZ-induced DN developed less albuminuria, tubulointerstitial fibrosis and β-catenin signaling activation. Furthermore, clinical studies showed that urinary SLPI protein level (uSLPI/Cr) had significant correlation with intrarenal SLPI mRNA and interstitial fibrosis. In an independent prospective cohort enrolled 711 patients with biopsy proven DN, uSLPI/Cr level was significantly associated with eGFR slope and improved the prediction value of renal outcome. Together, our study identified SLPI as a novel critical regulator for the progression of tubulointerstitial injury, which may be used as an independent risk predictor of DN progression.
Project description:Signal peptide peptidase (SPP) plays an essential role in among all eukaryotes. The knock out lines of A. thaliana SPP (AtSPP) is lethal and the substrates of AtSPP are not identified. Based on the situation, we constructed the plants with AtSPP over-expressed and knock down to investigate the role of AtSPP. We also used the data to find the candidate substrates of AtSPP, which regulates intermembrane proteolysis, would have crucial physiological functions as well as control the gene expression encoding the substrates.
Project description:Secretory Leukocyte Peptidase Inhibitor (SLPI) is a Novel Predictor of Tubulointerstitial Injury and Renal Outcome in Patients with Diabetic Nephropathy
Project description:We report that the PRC1 component polycomb group ring finger 6 (Pcgf6) is required to maintain embryonic stem cell (ESC) identity. In contrast to canonical PRC1, Pcgf6 acts as a positive regulator of transcription and binds predominantly to promoters bearing active chromatin marks. Pcgf6 is expressed at high levels in ESCs, and knockdown reduces the expression of the core ESC regulators Oct4,Sox2, and Nanog. Conversely, Pcgf6 overexpression prevents downregulation of these factors and impairs differentiation. In addition, Pcgf6 enhanced reprogramming in both mouse and human somatic cells. The genomic binding profile of Pcgf6 is highly similar to that of trithorax group proteins, but not of PRC1 or PRC2 complexes, suggesting that Pcgf6 functions atypically in ESCs. Our data reveal novel roles for Pcgf6 in directly regulating Oct4, Nanog, Sox2, and Lin28 expression to maintain ESC identity. To identify Pcgf6-bound genomic DNA regions in mouse embryonic stem cells, we fixed mouse ESCs and isolated Pcgf6-bound genomic DNA regions for deep sequencing analysis.