Adducin- and ouabain-related gene variants predict the antihypertensive activity of rostafuroxin, part 1: experimental studies.
Essential hypertension is a complex, multifactorial disease associated with a high cardiovascular risk and whose genetic-molecular basis is heterogeneous and largely unknown. Although multiple antihypertensive therapies are available, the large individual variability in drug response results in only a modest reduction of the cardiovascular risk and unsatisfactory control of blood pressure in the hypertensive population as a whole. Two mechanisms, among others, are associated with essential hypertension and related organ damage: mutant α-adducin variants and high concentrations of endogenous ouabain. An antihypertensive agent, rostafuroxin, selectively inhibits these mechanisms in rodents. We investigated the molecular and functional effects of mutant α-adducin, ouabain, and rostafuroxin in hypertensive rats, human cells, and cell-free systems and demonstrated that both mutant α-adducin variants and the ouabain-Na,K-ATPase (Na(+)- and K(+)-dependent adenosine triphosphatase) complex can interact with the Src-SH2 (Src homology 2) domain, increasing Src activity and the Src-dependent Na,K-ATPase phosphorylation and activity. Wild-type α-adducin or Na,K-ATPase in the absence of ouabain showed no interaction with the Src-SH2 domain. Rostafuroxin disrupted the interactions between the Src-SH2 domain and mutant α-adducin or the ouabain-Na,K-ATPase complex and blunted Src activation and Na,K-ATPase phosphorylation, resulting in blood pressure normalization in the hypertensive rats. We have also shown the translatability of these data to humans in a pharmacogenomic clinical trial, as described in the companion paper.
Prassis sigma-tau Research Institute, Settimo Milanese, Milan 20019, Italy.
Mara
M
Ferrandi
Isabella
I
Molinari
Lucia
L
Torielli
Gloria
G
Padoani
Sergio
S
Salardi
Maria Pia
MP
Rastaldi
Patrizia
P
Ferrari
Giuseppe
G
Bianchi
D000732:Androstanols / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002148:Calmodulin-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D002474:Cell-Free System; D004789:Enzyme Activation / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D008297:Male; D050505:Mutant Proteins / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014162:Transfection; D018909:src Homology Domains; D019061:src-Family Kinases / Q000737:chemistry / Q000378:metabolism; D000099291:Adducins
D000732:Androstanols; D000959:Antihypertensive Agents; D002148:Calmodulin-Binding Proteins; D050505:Mutant Proteins; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D019061:src-Family Kinases; D000099291:Adducins; C106263:rostafuroxin