Depiction of molecular mechanism and signaling pathways of estrogen in CRS. The molecular mechanism of mitochondrial dysfunction in CRS is involved in PGC-1, NRF 1/2, CREB, and PPARs signaling pathways. Estrogen increases PGC-1 expression and prevents the development of CRS via its receptors and NO/cGMP signaling pathways. Abbreviations: PGC-1, peroxisome proliferators activated receptor gamma coactivator 1; NRF, nuclear respiratory factors, PPARs, peroxisome proliferators activated receptors; CREB, cyclic AMP response element binding protein; NO, nitric oxide; cGMP, cyclic guanosine monophosphate.