Candidate genes of hypertension with defective environmental expression

Abstract

Previous studies in our laboratory have demonstrated that the thermosensitivity locus cosegregates with blood pressure and that the elevated expression and restriction fragment length polymorphism of HSP70 gene are associated with hypertension. Cell protection against environmental stressors such as heat and chemicals is often accompanied by up-regulated expression of a wide spectrum of heat shock genes(HSP). To further investigate the interrelation between HSP expression and blood pressure regulation, we employed an effective method of cloning 2 potential hypertension-related HSPs. Synthetic oligonucleotides corresponding either to a highly-conserved region of the known HSP family or a repetitive sequence in the protein encoding gene were used as target primers for polymerase chain reaction (PCR). cDNA prepared from heat-stressed and non-stressed vascular smooth muscle cells (VSMC) of Brown Norway rats (BN.lx) and spontaneously hypertensive rats (SHRp) respectively served as template in the reaction. The PCR products were subsequently analyzed in a single-stranded conformational polymorphism (SSCP) electrophoresing system. Differential gene expression in BN. lx and SHRp was seen on autoradiographs of SSCP gel by comparing the migration patterns of PCR-amplified DNA fragments. Using this technique, we also found that HSP27 and a new member of the large HSP gene family were differentially expressed in BN.1x and SHRp VSMC.