Enhanced Glycogen Metabolism Supports the Survival and Proliferation of HPV-Infected Keratinocytes in Condylomata Acuminata

Abstract

Condylomata acuminata (CA) is caused by human papillomavirus (HPV) infections of keratinocytes and is a common sexually transmitted disease. The main clinical feature and risk of CA is the high recurrence of genital warts formed by infected keratinocytes. Metabolic reprogramming of most types of mammalian cells including keratinocytes can provide energy and intermediates essential for their survival. Here, we report that HPV infection develops a hypoxic microenvironment in CA warts by inducing the accumulation of glycogen and increased glycogen metabolism in the infected keratinocytes in a hypoxia-inducible factor 1α (HIF-1α) -dependent pathway. Our in vitro studies show that the increased glycogen metabolism is essential for the survival and proliferation of keratinocytes. Regarding its mechanism of action, glycogenolysis generates glucose-1-phosphate that fluxes into the pentose phosphate pathway and, then, generates abundant nicotinamide adenine dinucleotide phosphate, thereby ensuring high levels of glutathione in keratinocytes under hypoxia. The abrogation of glycogen synthesis and glycogenolysis decreases the ratio of glutathione and glutathione disulfide and increases the level of ROS, further resulting in the impairment of keratinocyte survival. Collectively, our work offers an insight into the metabolic reprogramming in the development of CA and implies that the intervention of glycogen metabolism would be a promising therapeutic target for CA.