MicroRNA-221 promotes proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) by targeting tissue inhibitor of metalloproteinases-3 (TIMP3)

Erratum to microRNA-221 promotes proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) by targeting tissue inhibitor of metalloproteinases-3 (TIMP3)

[This corrects the article DOI: 10.21037/cdt-20-328.].

Administration of A. muciniphila ameliorates pulmonary arterial hypertension by targeting miR-208a-3p/NOVA1 axis

Pulmonary arterial hypertension (PH) is a chronic disease induced by a progressive increase in pulmonary vascular resistance and failure of the right heart function. A number of studies show that the development of PH is closely related to the gut microbiota, and lung-gut axis might be a potential therapeutic target in the PH treatment. A. muciniphila has been reported to play a critical role in treating cardiovascular disorders. In this study we evaluated the therapeutic effects of A. muciniphila against hypoxia-induced PH and the underlying mechanisms. Mice were pretreated with A. muciniphila suspension (2 × 108 CFU in 200 μL sterile anaerobic PBS, i.g.) every day for 3 weeks, and then exposed to hypoxia (9% O2) for another 4 weeks to induce PH. We showed that A. muciniphila pretreatment significantly facilitated the restoration of the hemodynamics and structure of the cardiopulmonary system, reversed the pathological progression of hypoxia-induced PH. Moreover, A. muciniphila pretreatment significantly modulated the gut microbiota in hypoxia-induced PH mice. miRNA sequencing analysis reveals that miR-208a-3p, a commensal gut bacteria-regulated miRNA, was markedly downregulated in lung tissues exposed to hypoxia, which was restored by A. muciniphila pretreatment. We showed that transfection with miR-208a-3p mimic reversed hypoxia-induced abnormal proliferation of human pulmonary artery smooth muscle cells (hPASMCs) via regulating the cell cycle, whereas knockdown of miR-208a-3p abolished the beneficial effects of A. muciniphila pretreatment in hypoxia-induced PH mice. We demonstrated that miR-208a-3p bound to the 3'-untranslated region of NOVA1 mRNA; the expression of NOVA1 was upregulated in lung tissues exposed to hypoxia, which was reversed by A. muciniphila pretreatment. Furthermore, silencing of NOVA1 reversed hypoxia-induced abnormal proliferation of hPASMCs through cell cycle modulation. Our results demonstrate that A. muciniphila could modulate PH through the miR-208a-3p/NOVA1 axis, providing a new theoretical basis for PH treatment.

Critical miRNAs in regulating pulmonary hypertension: A focus on Signaling pathways and therapeutic Targets

Pulmonary hypertension (PH) is complex disease as a result of obstructive pulmonary arterial remodeling, which in turn results in elevated pulmonary arterial pressure (PAP) and subsequent right ventricular heart failure, eventually leading to premature death. However, there is still a lack of a diagnostic blood-based biomarker and therapeutic target for PH. Because of the difficulty of diagnosis, new and more easily accessible prevention and treatment strategy are being explored. New target and diagnosis biomarkers should also allow for early diagnosis. In biology, miRNAs are short endogenous RNA molecules that are not coding. It is known that miRNAs can regulate gene expression and affect a variety of biological processes. Besides, miRNAs have been proven to be a crucial factor in PH pathogenesis. miRNAs have various effects on pulmonary vascular remodeling and are expressed differentially in various pulmonary vascular cells. Nowadays, it has been shown to be critical in the functions of different miRNAs in the pathogenesis of PH. Therefore, clarifying the mechanism of miRNAs regulating pulmonary vascular remodeling is of great importance to explore new therapeutic targets of PH and improve the survival qualify and time of patients. This review is focused on the role, mechanism, and potential therapeutic targets of miRNAs in PH and puts forward possible clinical treatment strategies.

Hypoxia activates GPR146 which participates in pulmonary vascular remodeling by promoting pyroptosis of pulmonary artery endothelial cells

BACKGROUND

Hypoxia is a risk factor of pulmonary hypertension (PH) and may induce pulmonary artery endothelial cells (PAECs) injury and inflammation. Pyroptosis is a form of cell death through maturation and secretion of inflammatory mediators. However, the mechanistic association of pyroptosis, PAECs injury, and inflammation remain unknown. Here, we explored in detail the effects of hypoxia on pyroptosis of PAECs.

EXPERIMENTAL APPROACH

Using RNA sequencing, we screened differentially expressed genes in pulmonary artery tissue of a Sugen5416/hypoxia-induced (SuHx) rat PH model. We examined the role of the differentially expressed gene G-protein coupled receptor 146 (GPR146) in PAECs through immunohistochemistry, immunofluorescence, CCK-8 assays, western blotings, real-time PCR, detection of reactive oxygen species, and lactate dehydrogenase release experiments.

KEY RESULTS

According to RNA sequencing, GPR146 was 11.64-fold increased in the SuHx-induced PH model, compared to the controls. Further, GPR146 was highly expressed in pulmonary arterial hypertension human lung tissue and SuHx-induced rat PH lung tissues. Our results suggested that the expression of pyroptosis-related proteins was markedly increased under hypoxia, both in vivo and in vitro, which was inhibited by silencing GPR146. Moreover, inhibiting NLRP3 or caspase-1 effectively suppressed cleavage of caspase-1, production of interleukin (IL)-1β, IL-6, and IL-18 in PAECs by hypoxia and overexpression of GPR146.

CONCLUSION

Our results indicated that GPR146 induced pyroptosis and inflammatory responses through the NLRP3/caspase-1 signaling axis, thus triggering endothelial injury and vascular remodeling. Hypoxia may promote PAECs pyroptosis through upregulation of GPR146 and thereby facilitate the progression of PH. Taken together, these insights may help identify a novel target for the treatment of PH.