Hypoxia activates GPR146 which participates in pulmonary vascular
remodeling by promoting pyroptosis of pulmonary artery endothelial cells
Abstract
Background and Purpose:Hypoxia, as a risk factor for pulmonary
hypertension (PH), was an inducing factor for pulmonary artery
endothelial cells (PAECs) injury and inflammation. Pyroptosis induced
cell death along with the maturation and secretion of the inflammatory
mediators. However, the correlation among pyroptosis, PAECs injury and
inflammation remain unknown. Here, we explored, in detail, the effect of
hypoxia on pyroptosis of PAECs. Experimental approach:Using RNA-seq
sequencing method, we screened differentially expressed genes in
pulmonary artery in SU5416-induced hypoxia PH model. Next, we verified
the role and mechanism of the differentially expressed gene GPR146 in
PAECs by immunohistochemistry, immunofluorescence, CCK8, western
blotting, realtime PCR, and LDH release experiments. Key Results: Our
results showed that GPR146 was highly expressed in PH human lung tissue
and Sugen5416/hypoxia (SuHx) induced rat PAH lung tissues. Meanwhile,
our data suggested the expression of pyroptosis-related proteins was
remarkably increased under hypoxia both in vivo and in vitro, which were
inhibited by silencing GPR146. Moreover, inhibiting NLRP3 or caspase-1
effectively suppressed cleavage of caspase-1, production of interleukin
(IL)-1β and IL-18 in PAECs by hypoxia and overexpression of GPR146.
Conclusion and Implications: Our results indicated that GPR146 induced
pyroptosis and inflammatory responses through the NLRP3/caspase-1
signaling axis, triggering endothelial injury and vascular remodeling.
Hypoxia could promote PAECs pyroptosis through upregulation of GPR146 to
affect the progression of PH, which might provide novel targets for
treatment of PH.