Genetic variants in HSP40 co-chaperones modulate ischemic heart disease risk

The chaperoning system, which is responsible for protein homeostasis, plays a significant role in cardiovascular diseases. Among molecular chaperones or heat shock proteins (HSPs), the HSP40 family, the main co-chaperone of HSP70, remains largely underexplored, especially in ischemic heart disease (IHD) risk.

We genotyped 834 IHD patients and 1,328 healthy controls for three SNPs (rs2034598 and rs7189628 DNAJA2 and rs4926222 DNAJB1) using probe-based real-time PCR. We observed that SNP rs7189628 DNAJA2 was associated with increased IHD risk in smokers (effect allele [EA] T, OR = 1.65, 95%CI 1.01-2.71, p = 0.036), while SNP rs2034598 DNAJA2 was associated with increased IHD risk in non-smokers (EA A, OR = 1.22, 95%CI 1.02-1.47, p = 0.036). Oppositely, SNP rs4926222 DNAJB1 was associated with reduced IHD risk in patients under 62 years old (EA G, OR = 0.73, 95%CI 0.54-0.98, p = 0.02). These SNPs also modulated clinical parameters: rs7189628 was associated with higher platelet counts in the entire group (p = 0.03) and males (p = 0.02), while rs2034598 was associated with lower platelet counts in the same groups accordingly (p = 0.03 and p = 0.047), earlier IHD onset in males (p = 0.03), and reduced activated partial thromboplastin time in smokers (p = 0.01); rs4926222 DNAJB1 was Linked to elevated prothrombin index in patients aged 62 and higher (p = 0.04) and lower BMI in smokers (p = 0.005) and males (p = 0.02).

Our findings suggest that genetic variants in the HSP40 family influence IHD risk and clinical features in a context-specific manner.