Heat shock protein 90 alpha and 14-3-3η in postmenopausal osteoporotic rats with varying levels of serum FSH.

Purpose: This study compared the severity of osteoporosis and screened differentially expressed proteins in postmenopausal osteoporotic rats with varying levels of serum follicle stimulating hormone (FSH).

Methods: Thirty-six Sprague Dawley female rats were divided into four groups: sham operation (sham) group, ovariectomy (OVX) group, FSH and ovariectomy (OVX + FSH) group, and Leuprorelin (LE) and ovariectomy group (OVX + LE). Body weight, serum estradiol, FSH, tartrate-resistant acid phosphatase, alkaline phosphatase, and bone mineral density were measured. We randomly selected six rats each from the OVX and OVX + FSH groups to detect differentially expressed proteins by data-independent acquisition, and we verified the results in the remaining six rats by enzyme-linked immunosorbent assay (ELISA).

Results: Nineteen proteins were upregulated and 36 proteins were downregulated in the OVX + FSH group. The expression of heat shock protein 90 alpha (Hsp90α) and 14-3-3η protein was significantly different between the OVX and OVX + FSH groups, and both were linearly correlated with bone trabecular area. Results were verified by ELISA and were found to be consistent with the results of data-independent acquisition.

Discussion: In rats with high serum FSH, expression of Hsp90α protein was increased and expression of 14-3-3η protein was decreased. Both changes in protein expression were strongly correlated with bone trabecular area.