Anti-heat shock protein 70 autoantibody epitope changes and BD091 promotes atherosclerosis in rats

Abstract

It has been previously reported that the plasma levels of autoantibodies against heat shock protein 70 (HSP70) are elevated in atherosclerosis. The aim of the present study was to elucidate whether anti-HSP70 antibodies are involved in the pathogenesis of atherosclerosis. To determine this, we chose rats as an atherosclerosis model. Titers of plasma anti-HSP70 autoantibody were determined by ELISA. After the intravenous administration of antibody into the tail, the damaged areas of aorta were stained with Evans Blue, atheromatous plaque were stained by Oil Red O, and then they were measured and quantified with AxioVision computer software. The number of macrophages (M 6 ), smooth muscle cells (SMCs), and T cells were determined by immunocytochemistry. The level of anti-HSP70 IgG1 antibody was apparently increased in the AS group at the tenth week, and one hybridoma of HSP70 antibody (BD091, IgG1, recognizing C-terminal) had the same binding epitope as plasma anti-HSP70 autoantibodies. After intravenous administration, the lesion area of aorta with BD091 was significantly larger than those of IgG mouse and SPA-810. Moreover, injection of BD091 resulted in significant endothelium damage, followed by a greater accumulation of M 6 , T cells, and SMCs in lesions than in the control. In conclusion, BD091 reaction with HSP70 expressed on arterial endothelial cells inducing endothelium damage triggers the inflammatory response in the vessel wall that accelerates atherosclerosis in rats. BD091 shares the same binding epitope with HSP70 autoantibodies. These data indicated that a specific epitope of anti-HSP70 autoantibody participated in the pathogenesis of atherosclerosis.

Diet-induced elevation of circulating HSP70 may trigger cell adhesion and promote the development of atherosclerosis in rats

“…As in our previous studies (Leng et al 2010(Leng et al , 2013, we successfully induced atherosclerotic pathological changes in rats' thoracic aorta accompanied by a significant elevation of plasma TC, LDL, Hcy, and most importantly by circulating HSP70. The increased plasma HSP70 probably derived from multiple cells.…”

Darapladib, a Lipoprotein-Associated Phospholipase A2 Inhibitor, Reduces Rho Kinase Activity in Atherosclerosis

“…Twelve rats given a normal diet were designated as a sham group, and the other 36 rats were fed with a high-cholesterol diet for 10 weeks to induce atherosclerosis. 14 15 The high-cholesterol diet contained 3% cholesterol, 0.5% cholic acid, 0.2% 6-propyl 2-thiouracil, 5% sucrose, and 3% lard. Subsequently, the 36 hyperlipidemic rats were randomly and evenly assigned to three groups: a control group that was administered normal saline, a low-dose darapladib group that received darapladib by gavage (25 mg·kg -1 ·d -1 , reconstituted in normal saline), and a high-dose darapladib group that received darapladib by gavage (50 mg·kg -1 ·d -1 , reconstituted in normal saline).…”

Evidence of a role for both anti-Hsp70 antibody and endothelial surface membrane Hsp70 in atherosclerosis

“…To analyze whether Hsp70 was present within the membrane preparation, the PVDF membranes were blocked for 2 h at room temperature with 3 % gelatin in Tris-buffered saline (500 mmol/L NaCl and 20 mmol/L Tris, pH8.0), and then incubated with mAb against Hsp70 (BD091, 1:80 in Tris-buffered saline containing 1 % gelatin and 0.05 % Tween 20) (Leng et al, 2010), HSC70 (SPA-815, Stressgen) for overnight at 4°C. The purity of the fractions was tested using HSC70 antibody which detected HSC70 in the cytoplasmic fraction but not in the membrane fraction.…”

“…We have previously shown that anti-Hsp70 antibody (BD091) promotes atherosclerosis in rats (Leng et al 2010). An important question that remains unanswered is how does BD091 promote atherosclerosis?…”