Abstract:

Objective To analyze the role of peroxisome proliferator-activated receptors （PPAR-γ） expression in P. acnes-induced pyroptosis， cell proliferation and apoptosis in human keratinocytes （HaCaT） so as to provide a new theoretical basis for clinical treatment. Methods Expression patterns of PPAR-γ in acne and normal skin tissues were evaluated using IHC. By lentiviral transfection， PPAR-γ was upregulated in HaCaT cells， and the expression of PPAR-γ was verified by Western blot. ELISA was performed to analyze the levels of P. acnes-induced pyroptotic-associated inflammatory factors IL-1β and IL-18. EdU assay and flow cytometry were used to detect the cell proliferation and apoptosis ability. Western blot was used to determine the levels of NLR family pyrin domain containing 3 （NLRP3）， cysteinyl aspartate specific proteinase-1 （caspase-1）， Gasdermin D （GSDMD） and PPAR-γ expression． Results PPAR-γ expression was significantly decreased in acne （P < 0.05）. Compared with the control， the P. acnes-induced pyroptotic-associated inflammatory factors IL-1β and IL-18 were increased （P < 0.01）， the pyroptotic-associated proteins were increased significantly （P < 0.05）. After treatment with P. acnes， the up-regulated PPAR-γ reduced the expression of IL-1β and IL-18 and HaCaT cell apoptosis， promoted the cell proliferation， up-regulated the expression of NLRP3， Caspase-1 and GSDMD in human keratinocytes all in a statistically significant way （all P < 0.05）. Conclusion PPAR-γ can effectively regulate P. acnes-induced pyroptosis， cell proliferation and apoptosis in human keratinocytes.

Key words: peroxisome proliferator-activated receptors?γ, pyroptosis, inflammation, keratinocyte, acne, cell proliferation, apoptosis