Effects of polymorphisms of heat shock protein 70 gene on ischemic stroke, and interaction with smoking in China

BackgroundHeat shock protein 70 (HSP70) plays a key role in up-regulating stress responses, and it may be involved in the pathogenesis of ischemic stroke (IS). However, whether HSP70 polymorphisms are a risk factor for IS is still controversial.MethodsThree polymorphisms of HSP70 gene (+ 190G/C, + 1267A/G, and + 2437T/C) were analyzed by PCR-RFLP in Chinese patients with IS (n = 116) and elderly subjects without IS (n = 116).ResultsThe genotype distribution of HSP70-2 and HSP70-hom was not different significantly, but the genotype distribution of HSP70-1 at + 190 was different significantly between the patients and controls. The allele frequency of HSP70-1 b2 was significantly higher in the patients (36.64%) than the controls (21.99%, P < 0.001). The frequency of HSP70-1 b1b2 genotype was higher in the patients (64.66%) than the controls (37.07%; OR, 3.62). Conditional logistic regression revealed that + 190 b2b2 + b1b2 genotypes was an independent risk factor for IS (OR, 5.41). After adjustment for other risk factors, the interaction between the HSP70-1 genotype and smoking was confirmed (I(AB),2.78).ConclusionsHSP70-1 + 190G/C may affect susceptibility to IS and smoking along with HSP70-1+190G/C may increase the risk of IS.