Tadalafil Integrates Nitric Oxide-Hydrogen Sulfide Signaling to Inhibit High Glucose-induced Matrix Protein Synthesis in Podocytes.
Diabetes-induced kidney cell injury involves an increase in matrix protein expression that is only partly alleviated by current treatment, prompting a search for new modalities. We have previously shown that hydrogen sulfide (H2S) inhibits high glucose-induced protein synthesis in kidney podocytes. We tested whether tadalafil, a phosphodiesterase 5 inhibitor used to treat erectile dysfunction, ameliorates high glucose stimulation of matrix proteins by generating H2S in podocytes. Tadalafil abrogated high glucose stimulation of global protein synthesis and matrix protein laminin γ1. Tadalafil inhibited high glucose-induced activation of mechanistic target of rapamycin complex 1 and laminin γ1 accumulation in an AMP-activated protein kinase (AMPK)-dependent manner. Tadalafil increased AMPK phosphorylation by stimulating calcium-calmodulin kinase kinase β. Tadalafil rapidly increased the expression and activity of the H2S-generating enzyme cystathionine γ-lyase (CSE) by promoting its translation. dl-Propargylglycine, a CSE inhibitor, and siRNA against CSE inhibited tadalafil-induced AMPK phosphorylation and abrogated the tadalafil effect on high glucose stimulation of laminin γ1. In tadalafil-treated podocytes, we examined the interaction between H2S and nitric oxide (NO). N(ω)-Nitro-L-arginine methyl ester and 1H-[1,2,4]-oxadiazolo-[4,3-a]-quinoxalin-1-one, inhibitors of NO synthase (NOS) and soluble guanylyl cyclase, respectively, abolished tadalafil induction of H2S and AMPK phosphorylation. Tadalafil rapidly augmented inducible NOS (iNOS) expression by increasing its mRNA, and siRNA for iNOS and 1400W, an iNOS blocker, inhibited tadalafil stimulation of CSE expression and AMPK phosphorylation. We conclude that tadalafil amelioration of high glucose stimulation of synthesis of proteins including matrix proteins in podocytes requires integration of the NO-H2S-AMPK axis leading to the inhibition of high glucose-induced mechanistic target of rapamycin complex 1 activity and mRNA translation.
From the Department of Medicine, University of Texas Health Science Center and South Texas Veterans Healthcare System, San Antonio, Texas 78229.
Hak Joo
HJ
Lee
From the Department of Medicine, University of Texas Health Science Center and.
Denis
D
Feliers
From the Department of Medicine, University of Texas Health Science Center and South Texas Veterans Healthcare System, San Antonio, Texas 78229.
Meenalakshmi M
MM
Mariappan
From the Department of Medicine, University of Texas Health Science Center and.
Kavithalakshmi
K
Sataranatarajan
From the Department of Medicine, University of Texas Health Science Center and South Texas Veterans Healthcare System, San Antonio, Texas 78229.
Goutam Ghosh
GG
Choudhury
From the Department of Medicine, University of Texas Health Science Center and.
Yves
Y
Gorin
From the Department of Medicine, University of Texas Health Science Center and South Texas Veterans Healthcare System, San Antonio, Texas 78229 Kasinath@uthscsa.edu.
Balakuntalam S
BS
Kasinath
D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000737:chemistry; D002243:Carbolines / Q000737:chemistry*; D003928:Diabetic Nephropathies / Q000188:drug therapy / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005786:Gene Expression Regulation; D005947:Glucose / Q000737:chemistry*; D006862:Hydrogen Sulfide / Q000737:chemistry*; D007668:Kidney / Q000166:cytology; D000076222:Mechanistic Target of Rapamycin Complex 1; D051379:Mice; D046912:Multiprotein Complexes / Q000378:metabolism; D009569:Nitric Oxide / Q000737:chemistry*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors; D058986:Phosphodiesterase 5 Inhibitors / Q000737:chemistry; D010766:Phosphorylation; D050199:Podocytes / Q000166:cytology / Q000378:metabolism*; D011132:Polyribosomes / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D000068581:Tadalafil
D002243:Carbolines; D046912:Multiprotein Complexes; D058986:Phosphodiesterase 5 Inhibitors; D009569:Nitric Oxide; D000068581:Tadalafil; D052247:Nitric Oxide Synthase Type II; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D005947:Glucose; D002118:Calcium; D006862:Hydrogen Sulfide
AMP-activated kinase (AMPK); diabetes; fibrosis; kidney; mammalian target of rapamycin (mTOR)