Project description:The purpose of this study is to learn how types of fat profiles differ between lean and obese individuals, and how they differ between racial groups. We are also interested in learning about the relationship of fat profiles with natriuretic peptide hormones, which are hormones produced by the heart. We will measure this by collecting tissue, blood and urine samples, energy expenditure measurements using the metabolic cart, and a DXA to assess the amount of bone, fat and muscle in the body from a single study visit.
Project description:Two natriuretic peptides, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) act through the common receptor, guanylyl cyclase-A (GC-A) to lower blood pressure, induce diuresis/natriuresis and dilate blood vessels. Recently, we discovered that the excessive cardiac hypertrophy accompanied with cardiac dysfunction was induced in the lactating natriuretic peptide receptor 1 (Npr1, which encodes GC-A)-deficient mice. To clarify the cause of lactation-induced cardic hypertrophy in Npr1-/-, we performed the gene expressions analysis using nulliparous (NP) or postpartum lactating wild-type (Npr1+/+) and Npr1-/- mice. Numerous genes were altered in the postpartum lactating period both in Npr1+/+ and Npr1-/-. Additionally, the involvement of inflammatory responce in the cardiac hypertrophy in lactating-Npr1-/- mice was clarified bythe gene ontology analysis.
Project description:The cardiac natriuretic peptide (NPs) plays an important role in the regulation of cardiovascular and renal function. We examined the miRNAs that could be regulating NPs by subjecting the cardiomyocytes, HCMa cells, to hypoxia.
Project description:Beige fat cells dissipate energy through mitochondrial uncoupling protein UCP1 defending against obesity and can be activated by thermogenic stimuli in white adipose tissue. Here, we provide candidate molecules involved in beige fat activation induced the TZD, rosiglitazone.
Project description:Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are not only important biological markers, but also regulators of cardiac functions. The natriuretic peptide A receptor (NPRA), also called NPR1 or guanylyl cyclase A (GC-A), binds with ANP or BNP ligand and fulfils transmembrane signalling transduction by elevating the intracellular levels of cGMP. However, the comprehensive effects and mechanisms downstream to NPRA are still largely to be elucidated. Here, the cardiac expressing profiles of mRNA in the mice with myocardium-specific deletion of NPRA were analyzed. It was found that differently expressed mRNAs were detected and proved by Gene Ontology (GO) and pathway analysis to be mainly related to the metabolic process. Moreover, circular RNAs (circRNAs) were scrutinized, and subsequently a possible regulatory network consisting of circRNAs- MicroRNAs (miRNAs) -mRNAs was predicted and constructed by ceRNA (competing endogenous RNA) analysis. In conclusion, NPRA plays possible roles in cardiac metabolism, which might be mediated by circRNAs via endogenous competition mechanisms.
Project description:Here we show that synthesis of the mitochondrial phospholipid cardiolipin is an indispensable driver of thermogenic fat function. Cardiolipin biosynthesis is robustly induced in brown and beige adipose upon cold exposure. Mimicking this response by overexpressing cardiolipin synthase (Crls1) enhances energy consumption in mouse and human adipocytes. Crls1 deficiency diminishes mitochondrial uncoupling in brown and beige adipocytes and elicits a nuclear transcriptional response through ER stress-mediated retrograde communication. Cardiolipin depletion in brown and beige fat abolishes adipose thermogenesis and glucose uptake and renders animals strikingly insulin resistant. We further identify a rare human CRLS1 variant associated with insulin resistance and show that adipose CRLS1 levels positively correlate with insulin sensitivity. Thus, adipose cardiolipin is a powerful regulator of organismal energy homeostasis through thermogenic fat bioenergetics.
Project description:Natriuretic peptide receptor-A (NPR-A) is the principal receptor for the natriuretic peptides ANP and BNP. Targeted deletion of NPR-A in mouse glomerular podocytes significantly enhances renal injury in vivo in the DOCA-salt experimental model. It was therefore hypothesized that natriuretic peptides exert a direct protective effect on glomerular barrier integrity through activation of NPR-A and modulation of gene expression patterns in podocytes. RNA-seq analysis revealed a total of 158 DEGs with 81 downregulated DEGs and 77 upregulated DEGs in Npr1 deficient podocytes. Among the downregulated genes were protein S and semaphorin 3G, which are known to have a protective effect in podocytes. Protein S was also expressed in and secreted from isolated human glomeruli. GO enrichment analysis revealed that the upregulated DEGs in NPR-A deficient podocytes were associated with cell migration and motility. In line, BNP significantly decreased podocyte outgrowth from cultured glomeruli.
Project description:Deficit of oxygen and nutrients in the tumor microenvironment (TME) triggers abnormal angiogenesis that produces dysfunctional and leaky blood vessels, which fail to adequately perfuse tumor tissues. Resulting hypoxia, exacerbation of metabolic problems and generation of immunosuppressive TME undermine the efficacy of cancer treatment. These problems can be partially alleviated by angiogenesis inhibitors. Here we propose an alternative agonist-based normalization approach utilizing a derivative of the C-type natriuretic peptide (dCNP). This well-tolerated agent stimulated formation of highly functional tumor blood vessels to reduce hypoxia. Administration of dCNP also inhibited stromagenesis and reinvigorated the anti-tumor immune responses. Treatment with dCNP decelerated growth of primary tumors and suppressed their metastases. Moreover, inclusion of dCNP into the chemo-, radio- or immune-therapeutic regimens increased their efficacy against solid tumors. These results demonstrate the proof of principle for using activators of normalized angiogenesis to improve therapies against solid tumors and characterize dCNP as the first in class amongst such agents.
Project description:C-type natriuretic peptide (CNP) has been recently identified as an important anabolic regulator of endochondral bone growth, but the molecular mechanism mediating these effects are not completely understood. Here we demonstrate that CNP activates the p38 MAP kinase pathway in chondrocytes and that pharmacological inhibition of p38 blocks the anabolic effects of CNP in a tibia organ culture system. We further show that CNP stimulates endochondral bone growth largely through expansion of the hypertrophic zone of the growth plate, while delaying mineralization. Both effects are reversed by p38 inhibition. We performed Affymetrix microarray analyses to identify CNP target genes in the organ culture system. These studies confirmed that hypertrophic chondrocytes are the main targets of CNP signaling in the growth plate, potentially because cGMP-dependent kinases I and II, important transducers of CNP signaling and are expressed at much higher levels in these cells than in other areas of the tibia. One of the genes most strongly induced by CNP was the Ptgs2 gene, encoding Cox2. Real-time PCR confirmed that Cox2 expression was induced by CNP in hypertrophic chondrocytes, but surprisingly in a p38-independent manner. Moreover, Cox2 inhibition â in contrast to p38 inhibition - did not block the anabolic effects of CNP. In summary, our data identify novel target genes of CNP and demonstrate that the p38 pathway is a novel, essential mediator of CNP effects on endochondral ossification, with potential implications for numerous skeletal diseases. Experiment Overall Design: Tibiae from E15.5 day old embryonic mice were isolated and cultured in minimal media in the presence of vehicle, BSA/HCl (1mM), or C-type natriuretic peptide, CNP (10-6M). On the sixth day of treatment cultured tibias were micro-dissected into the resting/proliferating, hypertrophic, and mineralized areas. Distinct zones from approximately 24 bones were pooled together, from which RNA was isolated using the Qiagen RNeasy Lipid Extraction Kit. Once the quality of total RNA from three independent trials was determined using the Agilent 2100 bioanalyzer, microarray analyses were performed at the London Regional Genomics Centre using MOE430_2.0 Affymetrix arrays. Results were analyzed using GeneSpring 7.2 software.