Figure 21.

HSP70 can induce cardiomyocyte hypertrophy and proliferation of fibroblasts and vascular endothelial cells via TLR2. A, Cell surface areas of cardiomyocytes after 48‐hour stimulation by human recombinant HSP70 or vehicle under treatment of anti–TLR2 antibodies (Ab) or control antibodies. Cell surface areas of 25 cardiomyocytes were measured in specimens with anti‐sarcomeric α‐actinin staining in each group. Scale bars=20 μm. B, Expression levels of atrial natriuretic factor (Anf) and β‐myosin heavy chain (β‐Mhc) in cardiomyocytes after 48‐hour stimulation by human recombinant HSP70 or vehicle under treatment of anti‐TLR2 antibodies or control antibodies. Three samples were obtained from cells cultured in 6‐well plates in each group. Expression levels of each gene were normalized to those of GAPDH (Gapdh). C and D, Proliferation of fibroblasts (C) and vascular endothelial cells (D) after 24‐hour stimulation by human recombinant HSP70 or vehicle under treatment of anti‐TLR2 antibodies or control antibodies. Cell proliferation was assessed by means of dimethylthiazol‐carboxymethoxyphenyl‐sulfophenyl‐tetrazolium assay and was expressed as the percentage of the absorbance to the well with cells treated by vehicle and control antibodies. Data were obtained from 5 independent experiments. *P<0.05 vs vehicle; ^†P<0.05 vs control antibodies. HSP indicates heat shock protein; GAPDH, glyceraldehyde‐3‐phosphate dehydrogenase; TLR, Toll‐like receptor.