Premium
Structure‐Dependent β 2 Adrenergic Receptor Agonists Induce Mitochondrial Biogenesis through the G βγ ‐Akt‐eNOS‐cGMP Pathway
Author(s) -
Cameron Robert,
Beeson Craig,
Schnellmann Rick
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.1190.4
Subject(s) - formoterol , clenbuterol , protein kinase b , enos , mitochondrial biogenesis , chemistry , pharmacology , phosphorylation , mitochondrion , endocrinology , medicine , nitric oxide , nitric oxide synthase , biochemistry , budesonide , corticosteroid
Acute kidney injury (AKI) occurs in hospitalized patients and carries a high morbidity and mortality with no treatments beyond renal replacement therapy. AKI is characterized by mitochondrial dysfunction, particularly in the renal proximal tubule cell (RPTC). The induction of mitochondrial biogenesis (MB) is a therapeutic target for AKI. Our group has shown that formoterol, a βγ 2 adrenoceptor agonist, can induce MB in vitro and in vivo, and stimulate recovery of mitochondrial and renal function following AKI in mice. In contrast the β 2 adenoceptor agonist clenbuterol does not induce MB. Our goal was to elucidate the signaling pathway by which formoterol induces MB and examine why clenbuterol does not. RPTC were treated with 30 nM formoterol or 30 nM clenbuterol following pretreatment with DMSO, 100 nM gallein, 10 mM L‐NAME, 100 nM MK2206, or 5 mM ODQ for 30 min. Oxygen consumption rates (OCR) were measured using the Seahorse XF‐96 analyzer. Protein phosphorylation was assessed by immunoblot analsis. Formoterol, but not clenbuterol increased Akt phosphorylation in RPTC at 30 min, and this increase was attenuated by pretreatment with the G βγ inhibitor gallein. Pretreatment of RPTC with gallein also attenuated formoterol‐induced increases in FCCP‐uncoupled oxygen consumption rate (FCCP‐OCR), a biomarker of MB. eNOS is a downstream target of Akt and was measured following formoterol or clenbuterol treatment with and without the Akt inhibitor MK2206 (100 nM). Formoterol, but not clenbuterol increased eNOS phosphorylation at 1 hr, and this increase was attenuated by pretreatment with MK2206. Additionally, pretreatment with either the NOS‐inhibitor L‐NAME or the guanylate cyclase inhibitor ODQ attenuated formoterol‐induced increases in FCCP‐OCR. These results show that formoterol induces MB through a G βγ ‐Akt‐eNOS‐cGMP‐dependent pathway, while clenbuterol does not activate Akt to initiate this pathway. This study is the first to associate G βγ ‐and cGMP‐dependent signaling with β 2 ‐adrenoceptor induced MB. Support or Funding Information This study was supported by R01 GM084147 to RGS, F30 DK104550 to RBC, and by the Biomedical Laboratory Research and Development Program of the Department of Veterans Affairs (BX‐000851).