Plasmid-based short hairpin RNA against connective tissue growth factor attenuated monocrotaline-induced pulmonary vascular remodeling in rats

Abstract

Pulmonary hypertension is a life-threatening medical condition, and a growing body of evidence shows that the expression of connective tissue growth factor (CTGF) is significantly associated with its pathogenesis, making it an attractive therapeutic target. Our earlier work revealed that plasmid-based CTGF-specific short hairpin RNA (shRNA) could attenuate pulmonary artery smooth muscle cell (PASMC) proliferation and pulmonary vascular remodeling in rats exposed to cigarette smoke. In this study, we explored the therapeutic role of this shRNA plasmid in the treatment of monocrotaline-induced pulmonary vascular remodeling in rats, and demonstrated that the upregulation of CTGF in PASMCs following a single injection of monocrotaline could be attenuated by administration of the shRNA. Accordingly, this shRNA was found to repress monocrotaline-induced pulmonary vascular remodeling, as evidenced by its ability to reduce the percentage of muscularized vessels and the wall thickness of pulmonary vessels. We concluded that plasmid-based shRNA against CTGF attenuated pulmonary vascular remodeling in monocrotaline-treated rats. CTGF might be a potential target for the treatment of pulmonary vascular remodeling and pulmonary hypertension.

MicroRNA-26b attenuates monocrotaline-induced pulmonary vascular remodeling via targeting connective tissue growth factor (CTGF) and cyclin D1 (CCND1)

“…In our previous studies, we showed that intratracheal administration of CTGF or CCND1 shRNA could significantly, but only partially, restore monocrotaline-induced pulmonary artery remodeling [28, 29]. In the present study, we found that downregulation of miR-26b was responsible for the upregulation of CTGF and CCND1 in monocrotaline-induced pulmonary artery remodeling, and intratracheal administration of miR-26b could almost completely restore the pulmonary artery remodeling in monocrotaline-treated rats.…”

“…The expression patterns were analyzed and compared between the two groups, and no pattern was identified specific to monocrotaline treatment. Furthermore, the most significantly down-regulated miRNAs, miR-26b, was selected for further functional analysis due to its well documented role in regulating human cell proliferation [30, 31], as well as the predicted function to suppress the expression of CTGF and CCND1(www.targetscan.org), upregulation of which have both been reported to contribute to the development of PAH in our previous studies [29, 32, 33]. The following confirmatory real-time PCR showed mRNA expression levels of rPASMCs isolated from monocrotaline-treated rats and the controls for selected miRNA (Figure 2A, *P<0.01), and a comparable change were identified compared with our precedent microarray experiment.…”

“…Our previous studies have shown that downregulation of CTGF and CCND1 by intratracheally administered plasmid-based shRNA could significantly, but only partially, restore the monocrotaline-induced pulmonary artery remodeling by suppressing the target gene, respectively [28,29]. Considering the reports that the upregulation of CTGF and CCND1 substantially contributes to the development of pulmonary vascular remodeling, as well as the observation that miR-26b significantly suppresses CTGF and CCND1 expression, we next evaluated its effect on monocrotaline-induced pulmonary vascular remodeling, and determined the influence of miR-26b/EXGEN500 complex on the expression of CTGF and CCND1 in parallel with CTGF and CCND1 shRNAs in monocrotaline-treated rats.…”

“…In our previous study, we showed plasmid-based CTGF specific shRNA decelerated the proliferation of rPASMCs and attenuate monocrotaline-induced pulmonary artery remodeling via suppressing the expression of CTGF [29]. In another study, we demonstrated that knockdown of CCND1 with plasmid-based shRNA could significantly suppress the rPASMCs proliferation induced by smoke extract in vitro and ameliorated the pulmonary vascular remodeling in rats exposed to cigarette smoke in vivo [28].…”

A Time- and Compartment-Specific Activation of Lung Macrophages in Hypoxic Pulmonary Hypertension

“…While little is known regarding LXR’s in PH, macrophage specific LXR signaling is important in inhibiting macrophage activation and is anti-fibrotic via inhibition of macrophage recruitment and macrophage-induced IL6 release (30–33). While hypoxic mice demonstrate only mild pulmonary vascular remodeling, we found that connective tissue grown factor (CTGF), a well-established mediator of pulmonary vascular remodeling in PH, was activated in day 14 IM’s relative to day 4 IM’s (34, 35). We hypothesize that the coordinated “anti-inflammatory” and “pro-reparative” programming state in IM’s in hypoxic mice limits progressive perivascular remodeling seen in other animal models of PH.…”