Kisspeptins inhibit human airway smooth muscle proliferation

Sex and gender disparity in asthma is recognized and suggests a modulatory role for sex steroids, particularly estrogen. However, there is a dichotomous role for estrogen in airway remodeling, making it unclear whether sex hormones are protective or detrimental in asthma and suggesting a need to explore mechanisms upstream or independent of estrogen. We hypothesize that kisspeptin (Kp)/KISS1R signaling serves this role. Airway smooth muscle (ASM) is a key structural cell type that contributes to remodeling in asthma. We explored the role of Kp/KISS1R in regulating ASM proliferation. We report potentially novel data indicating that Kp and KISS1R are expressed in human airways, especially ASM, with lower expression in ASM from women compared with men and lower in patients with asthma compared with people without asthma. Proliferation studies showed that cleaved forms of Kp, particularly Kp-10, mitigated POGF-induced ASM proliferation. Pharmacological inhibition and shRNA knockdown of KISS1R increased basal ASM proliferation, which was further amplified by PDGF. The antiproliferative effect of Kp-10 in ASM was mediated by inhibition of MAPK/ERK/Akt pathways, with altered expression of PCNA, C/EBP-alpha, Ki-67, cyclin D1, and cyclin E leading to cell cycle arrest at G(0)/G(1) phase. Overall, we demonstrate the importance of Kp/KISS1R signaling in regulating ASM proliferation and a potential therapeutic avenue to blunt remodeling in asthma.

Automated summary

Sex and gender disparities in asthma are influenced by sex steroids, particularly estrogen. This study explores the role of kisspeptin (Kp)/KISS1R signaling in regulating airway smooth muscle (ASM) proliferation, an important process in asthma remodeling. The findings suggest that lower expression of Kp/KISS1R in ASM may contribute to increased proliferation in patients with asthma. Kp-10 shows potential as a therapeutic target to inhibit ASM proliferation through inhibition of MAPK/ERK/Akt pathways.