Role for miR-204 in human pulmonary arterial hypertension

Abstract

Pulmonary arterial hypertension (PAH) is characterized by enhanced proliferation and reduced apoptosis of pulmonary artery smooth muscle cells (PASMCs). Because microRNAs have been recently implicated in the regulation of cell proliferation and apoptosis, we hypothesized that these regulatory molecules might be implicated in the etiology of PAH. In this study, we show that miR-204 expression in PASMCs is down-regulated in both human and rodent PAH. miR-204 down-regulation correlates with PAH severity and accounts for the proliferative and antiapoptotic phenotypes of PAH-PASMCs. STAT3 activation suppresses miR-204 expression, and miR-204 directly targets SHP2 expression, thereby SHP2 up-regulation, by miR-204 down-regulation, activates the Src kinase and nuclear factor of activated T cells (NFAT). STAT3 also directly induces NFATc2 expression. NFAT and SHP2 were needed to sustain PAH-PASMC proliferation and resistance to apoptosis. Finally, delivery of synthetic miR-204 to the lungs of animals with PAH significantly reduced disease severity. This study uncovers a new regulatory pathway involving miR-204 that is critical to the etiology of PAH and indicates that reestablishing miR-204 expression should be explored as a potential new therapy for this disease. role of miR-204 in the etiology of PAH. Interestingly, using in silico and microarray gene expression analyses, we observed that among the 461 predicted targets of miR-204 (TargetScan 5.1), only 165 were increased by artificial miR-204 inhibition in control human PASMCs (n = 2 patients; Fig. S1 C). In accordance with the pro-proliferative and antiapoptotic phenotypes seen in PAH, several Src-STAT3-and NFAT-related genes were identified (Fig. S1 C). miR-204 expression is decreased in human PAH and correlates with PAH severityTo investigate the expression pattern of miR-204 in normal and pulmonary hypertensive lungs, we examined miR-204 expression levels in (a) lung biopsies from 8 individuals with nonfamilial PAH compared with biopsies from 8 individuals without pulmonary hypertension, (b) lungs from 6 mice with hypoxia-induced pulmonary hypertension compared with 5 control littermates, and (c) lungs from 5 rats with monocrotaline (MCT)-induced pulmonary hypertension compared with 10 control littermates ( Fig. 1 A). We found decreased levels of miR-204 in human and rodent pulmonary hypertensive lung tissues compared with normotensive lung samples. To characterize whether down-regulated miR-204 levels were specific to the lung in rats with pulmonary hypertension, we compared organ-specific levels of miR-204 between normal and pulmonary hypertensive rats (Fig. 1 B). Even if we were able to detect minimal amounts of miR-204 in most organs, miR-204 levels were only down-regulated in the lung and PAs but not in the aorta, liver, heart, and kidney in rats 3 wk after MCT injection (pulmonary hypertensive rats) compared with non-pulmonary hypertensive rats (Fig. 1 B).To test whether miR-204 down-regulation correlated with disease progression, we studied humans, mice, a...

Down‐regulation of miRNA‐204 by LMP‐1 enhances CDC42 activity and facilitates invasion of EBV‐associated nasopharyngeal carcinoma cells

“…Recently, this LMP-1-mediated Stat-3 activation was confirmed in a transgenic mouse model with specific epithelial expression of LMP-1 [26]. Results from a previous study suggest that activation of Stat-3 in pulmonary arterial hypertension suppresses miR-204 expression [9]. We speculated that LMP-1 might regulate the expression of miR-204 through the Stat-3 pathway.…”

“…It has been well known that LMP-1 can activate the Stat-3 signaling pathway [12,13]. In a previous study it has been documented that the expression of miR-204 was controlled by Stat-3 [9]. We then asked whether Stat-3 also regulated miR-204 in NPC.…”

“…The precipitated DNA was subjected to qPCR analysis by using specific primers to amplify across the miR-204 promoter region. The primers used in the PCR reactions were previously described [9]. Finally, the data were analyzed using the 2 À44Ct method [10].…”

Translational Advances in the Field of Pulmonary Hypertension.Translating MicroRNA Biology in Pulmonary Hypertension. It Will Take More Than “miR” Words

“…Reduced expression of miR-204 in PAH-PASMCs secondary to STAT3 (signal transducer and activator of transcription 3) activation was observed to enhance STAT3 (creating a positive feedback loop) and BRD4 (bromodomain containing 4) expression, leading to the overactivation of NFAT (nuclear factor of activated T cells), HIF-1a (hypoxia inducible factor-1a) (16), and RUNX2 (runt-related transcription factor 2) (17), all of which contribute to metabolic dysfunction, exaggerated proliferation, and often calcification. The critical implication of miR-204 dysregulation in PH was further supported by experiments in two animal models of PAH, in which restoration of miR-204 expression reversed remodeling and improved hemodynamics (15,16). Two additional miRNAs expressed by PAECs, miR-424 and miR-503, were found to be down-regulated in human PAH (18).…”

“…Highlighting additional similarities to tumor progression, miR-204 has been found to act as a tumor suppressor with a pivotal role in PAH (15). Reduced expression of miR-204 in PAH-PASMCs secondary to STAT3 (signal transducer and activator of transcription 3) activation was observed to enhance STAT3 (creating a positive feedback loop) and BRD4 (bromodomain containing 4) expression, leading to the overactivation of NFAT (nuclear factor of activated T cells), HIF-1a (hypoxia inducible factor-1a) (16), and RUNX2 (runt-related transcription factor 2) (17), all of which contribute to metabolic dysfunction, exaggerated proliferation, and often calcification.…”