Pyrroloquinoline quinone protects nucleus pulposus cells from hydrogen peroxide-induced apoptosis by inhibiting the mitochondria-mediated pathway. - Yang L; Rong Z; Zeng M; Cao Y; Gong X; Lin L; Chen Y; Cao W; Zhu L; Dong W (European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 2015)