ABSTRACT
Objective · To investigate the regulatory effects of inflammatory signaling pathway on the expression of G protein-coupled receptor class C group 5 member A (GPRC5A).Methods· Nuclear factor κB (NF-κB)-driven luciferase mice were intraperitoneally injected with lipopolysaccharide (LPS) to evaluate the activation of NF-κB in lungs.GPRC5A expression in lungs was assessed by Western blotting in the C57BL/6J mice injected with LPS.In vitro tests,human lung tumor cell lines Calu-1 and H322,and human embryonic kidney cell line HEK293T were administered with tumor nccrosis factor α (TNF-α) or transfected with p65 expression plasmid;Western blotting,RT-PCR,luciferase reporter gene experiment and immunofluorescence assay were used to analyze the effect of inflammation on GPRC5A expression.Results · Intraperitoneal injection of LPS induced activation of NF-κB pathway in lung tissues,which suppressed the expression of GPRC5A in mice lungs.In Calu-1 cells,TNF-α treatment greatly suppressed the expression of GPRC5A protein and mRNA.In HEK293T cells,transfection of p65 subunit of NF-κB suppressed the expression of GPRC5A promoter-driven luciferase reporter.The H322 cells transfected with green fluorescent protein-p65 almost did not express GPRC5A.Conclusion · NF-κB pathway acts at the promoter of GPRC5A and suppresses its mRNA and protein expression.
ABSTRACT
<p><b>UNLABELLED</b>objective: To investigate effects of buyang huanwu decoction (BYHWD) on the rats' myocardial hypertrophic model induced by abdominal aortic constriction, and to clarify the molecular regulatory mechanisms for sarcoplasmic reticulum calcium uptake.</p><p><b>METHODS</b>Hypertrophic myocardium rat model was induced by abdominal aorta constriction (AAC). Four weeks after modeling, rats were randomly divided into the sham-operation group (Group S), the AAC model group (Group M), the Enalapril group (Group E), and the BYHWD treatment group (Group BYHWD), respectively. The left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), + dp/dtmax,-dp/dtmax, cardiac output (CO), heart mass index (HMI), and left ventricular mass index (LVMI) were observed in each group after 12-week medication. The serum contents of the atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were detected using ELISA. The SERCA2a activity, the ex- pressions of SERCA2a, phospholamban (PLN), and PLN phosphorylation were observed finally.</p><p><b>RESULTS</b>Compared with Group S, LVSP and LVEDP significantly increased,-dp/dtmax and CO obviously decreased, the myocardial tissue was obviously thickened, the serum contents of ANP and BNP increased, the activity and expression of SERCA2a decreased, the SERCA2a/PLN ratio and PLN phosphorylation degree decreased in Group M (all P <0.05). Compared with Group M, LVEDP obviously decreased, -dp/dtmax and CO obviously increased, the hypertrophy myocardial tissue was obviously lessened, the serum contents of ANP and BNP decreased, the activity of SERCA2a increased, the relative expression contents of SERCA2a, Ser16, and Thrl7 were elevated in Group BYHWD (all P <0.05). BYHWD had significant roles in elevating the SERCA2a/PLN ratio and PLN phosphorylation degree (P <0.05).</p><p><b>CONCLUSION</b>BYHWD could significantly improve hemodynamics of heart failure rats, elevate CO, lessen cardiac hypertrophy, and improve the capabilities for sarcoplasmic reticulum calcium uptake.</p>