scholarly journals Role of Glycosylation in Corin Zymogen Activation

2007 ◽  
Vol 282 (38) ◽  
pp. 27728-27735 ◽  
Author(s):  
Xudong Liao ◽  
Wei Wang ◽  
Shenghan Chen ◽  
Qingyu Wu
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Cysteine Proteases ◽  
Biologically Active ◽  
Zymogen Activation ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Neonatal Cardiomyocytes ◽  
293 Cells ◽  
Atrial Natriuretic

The cardiac serine protease corin is the pro-atrial natriuretic peptide convertase. Corin is made as a zymogen, which is activated by proteolytic cleavage. Previous studies showed that recombinant human corin expressed in HEK 293 cells was biologically active, but activated corin fragments were not detectable, making it difficult to study corin activation. In this study, we showed that recombinant rat corin was activated in HEK 293 cells, murine HL-1 cardiomyocytes, and rat neonatal cardiomyocytes. In these cells, activated corin represented a small fraction of the total corin molecules. The activation of recombinant rat corin was inhibited by small molecule trypsin inhibitors but not inhibitors for matrix metalloproteinases or cysteine proteases, suggesting that a trypsin-like protease activated corin in these cells. Glycosidase digestion showed that rat and human corin proteins contained substantial N-glycans but little O-glycans. Treatment of HEK 293 cells expressing rat corin with tunicamycin prevented corin activation and inhibited its pro-atrial natriuretic peptide processing activity. Similar effects of tunicamycin on endogenous corin activity were found in HL-1 cells. Mutations altering the two N-glycosylation sites in the protease domain of rat corin prevented its activation in HEK 293 and HL-1 cells. Our results indicate that N-linked oligosaccharides play an important role in corin activation.

scholarly journals Expression and Secretion of an Atrial Natriuretic Peptide in Beige-Like 3T3-L1 Adipocytes

2019 ◽  
Vol 20 (24) ◽  
pp. 6128 ◽  
Author(s):  
In-Seon Bae ◽  
Sang Hoon Kim
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Peptide Hormone ◽  
Brown Adipocyte ◽  
Omega 3 ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Beige Adipocytes ◽  
Atrial Natriuretic

The browning of white adipose tissue (beige adipocytes) stimulates energy expenditure. Omega-3 fatty acids have been shown to induce thermogenic action in adipocytes via G-protein coupled receptor 120 (GPR120). Atrial natriuretic peptide (ANP) is a peptide hormone that plays the role of maintaining normal blood pressure in kidneys to inhibit Na+ reuptake. Recently, ANP was found to induce adipocyte browning by binding to NPR1, an ANP receptor. However, the expression of ANP in adipocytes has not yet been studied. Therefore, in this study, we investigate the expression of ANP in beige-like adipocytes induced by docosahexaenoic acids (DHA), T3, or a PPAR agonist, rosiglitazone. First, we found that brown adipocyte-specific genes were upregulated in beige-like adipocytes. DHA promoted ANP expression in beige-like cells, whereas DHA-induced ANP expression was abolished by GPR120 knockout. ANP secretion of beige-like adipocytes was increased via PKC/ERK1/2 signaling in the GPR120 pathway. Furthermore, ANP secreted from beige-like adipocytes acted on HEK-293 cells, the recipient cells, leading to increased cGMP activity. After the NPR1 knockdown of HEK-293 cells, cGMP activity was not changed. Taken together, our findings indicate that beige-like adipocytes induce ANP secretion, which may contribute to improving obesity-associated metabolic disease.

Corin, a Transmembrane Cardiac Serine Protease, as a Pro-Atrial Natriuretic Peptide Convertase

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 709-710
Author(s):  
Wei Yan ◽  
Faye Wu ◽  
John Morser ◽  
Qingyu Wu
Keyword(s):  
Blood Pressure ◽  
Atrial Natriuretic Peptide ◽  
Serine Protease ◽  
Natriuretic Peptide ◽  
Transmembrane Protein ◽  
Biologically Active ◽  
Expression Vectors ◽  
Sequence Specificity ◽  
293 Cells ◽  
Atrial Natriuretic

P92 Atrial natriuretic peptide (ANP) is a cardiac hormone that reduces high blood pressure by promoting salt excretion, decreasing blood volume and relaxing vessel tension. It is implicated in major cardiovascular diseases such as hypertension and congestive heart failure. In cardiomyocytes, ANP is synthesized as a precursor, pro-ANP, that is converted to biologically active ANP by an unknown membrane-associated serine protease. Recently, we cloned a novel cardiac serine protease, corin, that has the predicted structure of a type II transmembrane protein. Northern and in situ hybridization detected corin mRNA in the heart where its expression was most abundant in cardiomyocytes of the atrium. Corin mRNA was also detected in developing kidney and bones. The overall expression pattern of corin mRNA was very similar to that of ANP, leading to our hypothesis that corin is the pro-ANP convertase. To test this hypothesis, we constructed expression vectors for both human corin and pro-ANP. Recombinant corin and pro-ANP were expressed in human 293 cells. Effects of corin on pro-ANP processing was examined by western analysis. The results showed that human corin, but not control proteases prothrombin and hepsin, converted pro-ANP to ANP in the cell-based experiments. To determine sequence specificity of corin-mediated cleavage in pro-ANP, we constructed a mutant pro-ANP R98G in which the predicted cleave site residue Arg98 was replaced with a Gly. In co-transfection experiments, corin processed wild-type pro-ANP but not mutant pro-ANP R98G, indicating that corin-mediated cleavage in pro-ANP is highly sequence specific. We also examined effects of protease inhibitors on processing of pro-ANP by corin. Our results showed that the activity of corin was inhibited by aprotinin, benzamidine and leupeptin but not soybean trypsin inhibitor. Similar effects of these proteases on pro-ANP processing were reported previously. Thus, corin matches all known characteristics of the long-sought pro-ANP convertase. Identification of corin as the pro-ANP convertase suggests a new regulatory mechanism for the ANP-mediated pathway that is important for controlling blood pressure.

Cells expressing unique Na+/Ca2+ exchange (NCX1) splice variants exhibit different susceptibilities to Ca2+ overload

2006 ◽  
Vol 290 (5) ◽  
pp. H2155-H2162 ◽  
Author(s):  
Cecilia Hurtado ◽  
Michele Prociuk ◽  
Thane G. Maddaford ◽  
Elena Dibrov ◽  
Nasrin Mesaeli ◽  
...  
Keyword(s):  
Splice Variant ◽  
Cardiac Glycosides ◽  
Splice Variants ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Neonatal Cardiomyocytes ◽  
Simulated Ischemia ◽  
293 Cells ◽  
Intracellular Ca ◽  
Specific Alternative

The Na+/Ca2+ exchanger (NCX) NCX1 exhibits tissue-specific alternative splicing. Such NCX splice variants as NCX1.1 and NCX1.3 are also differentially regulated by Na+ and Ca2+, although the physiological implications of these regulatory characteristics are unclear. On the basis of their distinct regulatory profiles, we hypothesized that cells expressing these different splice variants might exhibit unique responses to conditions promoting Ca2+ overload, such as during exposure to cardiac glycosides or simulated ischemia. NCX1.1 or NCX1.3 was expressed in human embryonic kidney (HEK)-293 cells or rat neonatal ventricular cardiomyocytes (NVC), and expression was confirmed by Western blotting and immunocytochemical analyses. HEK-293 cells lacked NCX1 protein before transfection. With use of adenoviral vectors, neonatal cardiomyocytes were induced to overexpress the NCX1.1 splice variant by nearly twofold, whereas the NCX1.3 isoform was expressed on the endogenous NCX1.1 background. Total expression was comparable for NCX1.1 and NCX1.3. Exposure of NVC to ouabain induced a significant increase in cellular Ca2+, an effect that was exaggerated in cells overexpressing NCX1.1, but not NCX1.3. The increase in intracellular Ca2+ was inhibited by 5 μM KB-R7943. Cardiomyocytes overexpressing NCX1.1 also exhibited a greater accumulation of intracellular Ca2+ in response to simulated ischemia than did cells expressing NCX1.3. Similar responses were observed in HEK-293 cells where NCX1.1 was expressed. We conclude that expression of the NCX1.3 splice variant protects against severe Ca2+ overload, whereas NCX1.1 promotes Ca2+ overload in response to cardiac glycosides and ischemic challenges. These results highlight the importance of ionic regulation in controlling NCX1 activity under conditions that promote Ca2+ overload.

Atrial natriuretic peptide inhibits cell cycle activity of embryonic cardiac progenitor cells via its NPRA receptor signaling axis

2015 ◽  
Vol 308 (7) ◽  
pp. C557-C569 ◽  
Author(s):  
Adam Hotchkiss ◽  
Tiam Feridooni ◽  
Mark Baguma-Nibasheka ◽  
Kathleen McNeil ◽  
Sarita Chinni ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Progenitor Cells ◽  
Natriuretic Peptide ◽  
Biological Effects ◽  
Active Form ◽  
Specific Inhibitor ◽  
Ventricular Myocardium ◽  
Biologically Active ◽  
Cardiac Progenitor Cells ◽  
Atrial Natriuretic

The biological effects of atrial natriuretic peptide (ANP) are mediated by natriuretic peptide receptors (NPRs), which can either activate guanylyl cyclase (NPRA and NPRB) or inhibit adenylyl cyclase (NPRC) to modulate intracellular cGMP or cAMP, respectively. During cardiac development, ANP serves as an early maker of differentiating atrial and ventricular chamber myocardium. As development proceeds, expression of ANP persists in the atria but declines in the ventricles. Currently, it is not known whether ANP is secreted or the ANP-NPR signaling system plays any active role in the developing ventricles. Thus the primary aims of this study were to 1) examine biological activity of ANP signaling systems in embryonic ventricular myocardium, and 2) determine whether ANP signaling modulates proliferation/differentiation of undifferentiated cardiac progenitor cells (CPCs) and/or cardiomyocytes. Here, we provide evidence that ANP synthesized in embryonic day (E)11.5 ventricular myocytes is actively secreted and processed to its biologically active form. Notably, NPRA and NPRC were detected in E11.5 ventricles and exogenous ANP stimulated production of cGMP in ventricular cell cultures. Furthermore, we showed that exogenous ANP significantly decreased cell number and DNA synthesis of CPCs but not cardiomyocytes and this effect could be reversed by pretreatment with the NPRA receptor-specific inhibitor A71915. ANP treatment also led to a robust increase in nuclear p27 levels in CPCs compared with cardiomyocytes. Collectively, these data provide evidence that in the developing mammalian ventricles ANP plays a local paracrine role in regulating the balance between CPC proliferation and differentiation via NPRA/cGMP-mediated signaling pathways.

scholarly journals Processing of Pro–B-Type Natriuretic Peptide: Furin and Corin as Candidate Convertases2

2010 ◽  
Vol 56 (7) ◽  
pp. 1166-1176 ◽  
Author(s):  
Alexander G Semenov ◽  
Natalia N Tamm ◽  
Karina R Seferian ◽  
Alexander B Postnikov ◽  
Natalia S Karpova ◽  
...  
Keyword(s):  
Heart Failure ◽  
Natriuretic Peptide ◽  
Spectrometric Analysis ◽  
Precursor Molecule ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Lovo Cells ◽  
Interfering Rna

Abstract Background: B-type natriuretic peptide (BNP) and its N-terminal fragment (NT-proBNP) are the products of the enzyme-mediated cleavage of their precursor molecule, proBNP. The clinical significance of proBNP-derived peptides as biomarkers of heart failure has been explored thoroughly, whereas little is known about the mechanisms of proBNP processing. We investigated the role of 2 candidate convertases, furin and corin, in human proBNP processing. Methods: We measured proBNP expression in HEK 293 and furin-deficient LoVo cells. We used a furin inhibitor and a furin-specific small interfering RNA (siRNA) to explore the implication of furin in proBNP processing. Recombinant proBNPs were incubated with HEK 293 cells transfected with the corin-expressing plasmid. We applied mass spectrometry to analyze the products of furin- and corin-mediated cleavage. Results: Reduction of furin activity significantly impaired proBNP processing in HEK 293 cells. Furin-deficient LoVo cells were unable to process proBNP, whereas coexpression with furin resulted in effective proBNP processing. Mass spectrometric analysis revealed that the furin-mediated cleavage of proBNP resulted in BNP 1–32, whereas corin-mediated cleavage led to the production of BNP 4–32. Some portion of proBNP in the plasma of heart failure patients was not glycosylated in the cleavage site region and was susceptible to furin-mediated cleavage. Conclusions: Both furin and corin are involved in the proBNP processing pathway, giving rise to distinct BNP forms. The significance of the presence of unprocessed proBNP in circulation that could be cleaved by the endogenous convertases should be further investigated for better understanding BNP physiology.

Cytosolic Ca2+ during atrial natriuretic peptide secretion from cultured neonatal cardiomyocytes

1990 ◽  
Vol 73 (2-3) ◽  
pp. 153-163 ◽  
Author(s):  
Paavo A. Uusimaa ◽  
Heikki Ruskoaho ◽  
Juhani Leppäluoto ◽  
Ilmo E. Hassinen
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Neonatal Cardiomyocytes ◽  
Peptide Secretion ◽  
Atrial Natriuretic

HCaRG is a novel regulator of renal epithelial cell growth and differentiation causing G2M arrest

2003 ◽  
Vol 284 (4) ◽  
pp. F753-F762 ◽  
Author(s):  
Alison M. Devlin ◽  
Nicolas Solban ◽  
Sandra Tremblay ◽  
Jolanta Gutkowska ◽  
Walter Schürch ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Epithelial Cell ◽  
Atrial Natriuretic Peptide ◽  
Cell Size ◽  
Natriuretic Peptide ◽  
Renal Epithelial Cell ◽  
Hek 293 ◽  
Cell Growth And Differentiation ◽  
Atrial Natriuretic

We recently identified a novel calcium-regulated gene, HCaRG, that is highly expressed in the kidney and maps to a chromosomal locus determining kidney weight in rats. The mRNA levels of HCaRG negatively correlate with the proliferative status of the kidney cells. To investigate its role in renal epithelial cellular growth directly, we studied the human embryonic kidney cell line (HEK-293) stably transfected with either plasmid alone or plasmid containing rat HCaRG. [3H]thymidine incorporation was significantly lower in HCaRG clones. Although HCaRG clones exhibited some enhanced susceptibility to cell death, this was not the primary mechanism of reduced proliferation. Cell cycle analysis revealed a G2M phase accumulation in HCaRG clones that was associated with upregulation of p21Cip1/WAF1 and downregulation of p27Kip1. HCaRG clones had a greater protein content, larger cell size, and released 4.5- to 8-fold more of an atrial natriuretic peptide-like immunoreactivity compared with controls. In addition, HCaRG clones demonstrated the presence of differentiated junctions and a lower incidence of mitotic figures. Genistein treatment of wild-type HEK-293 cells mimicked several phenotypic characteristics associated with HCaRGoverexpresssion, including increased cell size and increased release of atrial natriuretic peptide. Taken together, our results suggest that HCaRG is a regulator of renal epithelial cell growth and differentiation causing G2M cell cycle arrest.

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