Activation of Lung p53 by Nutlin-3a Prevents and Reverses Experimental Pulmonary Hypertension

作者：Mouraret Nathalie; Marcos Elisabeth; Abid Shariq; Gary Bobo Guillaume; Saker Mirna; Houssaini Amal; Dubois Rande Jean Luc; Boyer Laurent; Boczkowski Jorge; Derumeaux Genevieve; Amsellem Valerie; Adnot Serge^*

来源：Circulation, 2013, 127(16): 1664-+.

DOI：10.1161/CIRCULATIONAHA.113.002434

• cell aging
• hypertension
• muscles
• pulmonary artery
• ventricular remodeling

Background-Induction of cellular senescence through activation of the p53 tumor suppressor protein is a new option for treating proliferative disorders. Nutlins prevent the ubiquitin ligase MDM2 (murine double minute 2), a negative p53 regulator, from interacting with p53. We hypothesized that cell senescence induced by Nutlin-3a exerted therapeutic effects in pulmonary hypertension (PH) by limiting the proliferation of pulmonary artery smooth muscle cells (PA-SMCs).
Methods and Results-Nutlin-3a treatment of cultured human PA-SMCs resulted in cell growth arrest with the induction of senescence but not apoptosis; increased phosphorylated p53 protein levels; and expression of p53 target genes including p21, Bax, BTG2, and MDM2. Daily intraperitoneal Nutlin-3a treatment for 3 weeks dose-dependently reduced PH, right ventricular hypertrophy, and distal pulmonary artery muscularization in mice exposed to chronic hypoxia or SU5416/hypoxia. Nutlin-3a treatment also partially reversed PH in chronically hypoxic or transgenic mice overexpressing the serotonin-transporter in SMCs (SM22-5HTT(+) mice). In these mouse models of PH, Nutlin-3a markedly increased senescent p21-stained PA-SMCs; lung p53, p21, and MDM2 protein levels; and p21, Bax, PUMA, BTG2, and MDM2 mRNA levels; but induced only minor changes in control mice without PH. Marked MDM2 immunostaining was seen in both mouse and human remodeled pulmonary vessels, supporting the use of Nutlins as a PH-targeted therapy. PH prevention or reversal by Nutlin-3a required lung p53 stabilization and increased p21 expression, as indicated by the absence of Nutlin-3a effects in hypoxia-exposed p53(-/-) and p21(-/-) mice.
Conclusions-Nutlin-3a may hold promise as a prosenescence treatment targeting PA-SMCs in PH. (Circulation. 2013; 127:1664-1676.)

• 出版日期2013-4-23