NLRP3 and obesity due to melanocortin 4 receptor deficiency: To further clarify the correlations which lead to insufficient T synthesis in obesity between the disorders of cholesterol metabolism and pyroptosis of LCs, elucidating the mechanism of PQQ improving male reproductive dysfunction, the expression of PCSK9 and NLRP3 that subsequently trigger to pyroptosis [27, 28] has been determined in testes at first.