ABSTRACT
Objective To investigate the etiologic roles of apoptosis-associated genes,environmental factors and their interactions in lumbar disc herniation (LDH).Methods A case-control trial was conducted.We recruited 128 outpatients with LDH as case group and 132 normal people matched by age and gender as control group.Peripheral venous blood samples were collected and DNA was extracted from leukocytes.By using a modified Brucker Autoflex MALDI-TOF mass spectrometer,we analyzed 3 genes with 9 polymorphic sites,namely,Fas-1377G/A rs2234767,Fas-670G/A rs1800682,Fas rs2147420,Fas rs2296603,Fas rs7901 656,Fas rs1 57101 9,FasL-844C/T rs7631 10,CASP-9-1263A > G rs4645978,and CASP-9-712C > T rs4645981.The correlations between polymorphism of Fas,FasL and CASP-9 genes and the risk of LDH were evaluated by non-conditional Logistic regression model.Multiple Logistic regression model was performed to assess the interaction between apoptosis-associated genes and environment factors,such as lumbar vertebral loads,bed type,spare-time exercises and spare-time activities. Results There were preferable balances in case and control groups in age and gender without significant differences.However,the two groups differed significantly (P G (rs4645978),and FasL-844C/T TT and CASP-9-1263A>G GG genotypes might be the high risk genotypes of LDH.The gene-environment interaction analysis revealed that super-multiplicative and sub-multiplicative interactions respectively between FasL-844TT genotype and lumbar vertebral loads (3-4 level),and between CASP-9-rs4645978 GG and lumbar vertebral loads (3-4 level).Conclusion FasL,CASP-9 genes and lumbar vertebral loads and their interactions play important roles in the pathogenesis of LDH.It suggests that the risk of LDH may be codetermined by environmental factors and inherited susceptibility genes,and that the mechanisms of interactions vary in different genotypes and the same or different environmental factors.