Limits...
Involvement of Cyclic Guanosine Monophosphate-Dependent Protein Kinase I in Renal Antifibrotic Effects of Serelaxin.

Wetzl V, Schinner E, Kees F, Hofmann F, Faerber L, Schlossmann J - Front Pharmacol (2016)

Bottom Line: The profibrotic connective tissue growth factor as well as myofibroblast differentiation were reduced and matrix metalloproteinases-2 and -9 were positively modulated after treatment.Moreover, Smad2 as well as extracellular signal-regulated kinase 1 (ERK1) phosphorylation were decreased, whereas phosphodiesterase (PDE) 5a phosphorylation was increased.However, these effects were not observed in cGKI-KO.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Toxicology, University of RegensburgRegensburg, Germany; Novartis Pharma GmbHNuremberg, Germany.

ABSTRACT

Introduction: Kidney fibrosis has shown to be ameliorated through the involvement of cyclic guanosine monophosphate (cGMP) and its dependent protein kinase I (cGKI). Serelaxin, the recombinant form of human relaxin-II, increases cGMP levels and has shown beneficial effects on kidney function in acute heart failure patients. Antifibrotic properties of serelaxin are supposed to be mediated via relaxin family peptide receptor 1 and subsequently enhanced nitric oxide/cGMP to inhibit transforming growth factor-β (TGF-β) signaling. This study examines the involvement of cGKI in the antifibrotic signaling of serelaxin.

Methods and results: Kidney fibrosis was induced by unilateral ureteral obstruction in wildtype (WT) and cGKI knock-out (KO) mice. After 7 days, renal antifibrotic effects of serelaxin were assessed. Serelaxin treatment for 7 days significantly increased cGMP in the kidney of WT and cGKI-KO. In WT, renal fibrosis was reduced through decreased accumulation of collagen1A1, total collagen, and fibronectin. The profibrotic connective tissue growth factor as well as myofibroblast differentiation were reduced and matrix metalloproteinases-2 and -9 were positively modulated after treatment. Moreover, Smad2 as well as extracellular signal-regulated kinase 1 (ERK1) phosphorylation were decreased, whereas phosphodiesterase (PDE) 5a phosphorylation was increased. However, these effects were not observed in cGKI-KO.

Conclusion: Antifibrotic renal effects of serelaxin are mediated via cGMP/cGKI to inhibit Smad2- and ERK1-dependent TGF-β signaling and increased PDE5a phosphorylation.

No MeSH data available.


Related in: MedlinePlus

Determination of (A) cGMP levels and (B) protein kinase activity of cGKI, determined by VASP phosphorylation (Ser239) in healthy or fibrotic kidney tissue of WT mice 7 days after UUO; mice were untreated or treated with serelaxin for 7 days during UUO. As described in methods increase of renal cGMP levels was quantified with ELISA according to manufacturer’s instructions. VASP phosphorylation at Ser 239 was determined by western blotting (50 μg protein) after normalization to GAPDH; cGMP, cyclic guanosine monophosphate; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; P-VASP, phospho-vasodilator- stimulating phosphoprotein; RLX, serelaxin; UUO, unilateral ureteral obstruction; ∗∗∗p < 0.001.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4940422&req=5

Figure 1: Determination of (A) cGMP levels and (B) protein kinase activity of cGKI, determined by VASP phosphorylation (Ser239) in healthy or fibrotic kidney tissue of WT mice 7 days after UUO; mice were untreated or treated with serelaxin for 7 days during UUO. As described in methods increase of renal cGMP levels was quantified with ELISA according to manufacturer’s instructions. VASP phosphorylation at Ser 239 was determined by western blotting (50 μg protein) after normalization to GAPDH; cGMP, cyclic guanosine monophosphate; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; P-VASP, phospho-vasodilator- stimulating phosphoprotein; RLX, serelaxin; UUO, unilateral ureteral obstruction; ∗∗∗p < 0.001.

Mentions: cGMP levels were investigated in kidney tissue. Figure 1A shows that cGMP was higher in fibrotic tissue 7 days after UUO than in the contralateral kidney (42.8 ± 5.7 vs. 25.9 ± 5.2 pmol/g). After RLX treatment cGMP levels of fibrotic kidneys further increased significantly (95.0 ± 12.5 pmol/g).


Involvement of Cyclic Guanosine Monophosphate-Dependent Protein Kinase I in Renal Antifibrotic Effects of Serelaxin.

Wetzl V, Schinner E, Kees F, Hofmann F, Faerber L, Schlossmann J - Front Pharmacol (2016)

Determination of (A) cGMP levels and (B) protein kinase activity of cGKI, determined by VASP phosphorylation (Ser239) in healthy or fibrotic kidney tissue of WT mice 7 days after UUO; mice were untreated or treated with serelaxin for 7 days during UUO. As described in methods increase of renal cGMP levels was quantified with ELISA according to manufacturer’s instructions. VASP phosphorylation at Ser 239 was determined by western blotting (50 μg protein) after normalization to GAPDH; cGMP, cyclic guanosine monophosphate; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; P-VASP, phospho-vasodilator- stimulating phosphoprotein; RLX, serelaxin; UUO, unilateral ureteral obstruction; ∗∗∗p < 0.001.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940422&req=5

Figure 1: Determination of (A) cGMP levels and (B) protein kinase activity of cGKI, determined by VASP phosphorylation (Ser239) in healthy or fibrotic kidney tissue of WT mice 7 days after UUO; mice were untreated or treated with serelaxin for 7 days during UUO. As described in methods increase of renal cGMP levels was quantified with ELISA according to manufacturer’s instructions. VASP phosphorylation at Ser 239 was determined by western blotting (50 μg protein) after normalization to GAPDH; cGMP, cyclic guanosine monophosphate; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; P-VASP, phospho-vasodilator- stimulating phosphoprotein; RLX, serelaxin; UUO, unilateral ureteral obstruction; ∗∗∗p < 0.001.
Mentions: cGMP levels were investigated in kidney tissue. Figure 1A shows that cGMP was higher in fibrotic tissue 7 days after UUO than in the contralateral kidney (42.8 ± 5.7 vs. 25.9 ± 5.2 pmol/g). After RLX treatment cGMP levels of fibrotic kidneys further increased significantly (95.0 ± 12.5 pmol/g).

Bottom Line: The profibrotic connective tissue growth factor as well as myofibroblast differentiation were reduced and matrix metalloproteinases-2 and -9 were positively modulated after treatment.Moreover, Smad2 as well as extracellular signal-regulated kinase 1 (ERK1) phosphorylation were decreased, whereas phosphodiesterase (PDE) 5a phosphorylation was increased.However, these effects were not observed in cGKI-KO.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Toxicology, University of RegensburgRegensburg, Germany; Novartis Pharma GmbHNuremberg, Germany.

ABSTRACT

Introduction: Kidney fibrosis has shown to be ameliorated through the involvement of cyclic guanosine monophosphate (cGMP) and its dependent protein kinase I (cGKI). Serelaxin, the recombinant form of human relaxin-II, increases cGMP levels and has shown beneficial effects on kidney function in acute heart failure patients. Antifibrotic properties of serelaxin are supposed to be mediated via relaxin family peptide receptor 1 and subsequently enhanced nitric oxide/cGMP to inhibit transforming growth factor-β (TGF-β) signaling. This study examines the involvement of cGKI in the antifibrotic signaling of serelaxin.

Methods and results: Kidney fibrosis was induced by unilateral ureteral obstruction in wildtype (WT) and cGKI knock-out (KO) mice. After 7 days, renal antifibrotic effects of serelaxin were assessed. Serelaxin treatment for 7 days significantly increased cGMP in the kidney of WT and cGKI-KO. In WT, renal fibrosis was reduced through decreased accumulation of collagen1A1, total collagen, and fibronectin. The profibrotic connective tissue growth factor as well as myofibroblast differentiation were reduced and matrix metalloproteinases-2 and -9 were positively modulated after treatment. Moreover, Smad2 as well as extracellular signal-regulated kinase 1 (ERK1) phosphorylation were decreased, whereas phosphodiesterase (PDE) 5a phosphorylation was increased. However, these effects were not observed in cGKI-KO.

Conclusion: Antifibrotic renal effects of serelaxin are mediated via cGMP/cGKI to inhibit Smad2- and ERK1-dependent TGF-β signaling and increased PDE5a phosphorylation.

No MeSH data available.


Related in: MedlinePlus