Simultaneous accumulation of Hyaluronan binding protein 1 (HABP1/p32/gC1qR) and apoptotic induction of germ cells in Cryptorchid testis

Abstract

In the experimentally cryptorchid rat, spermatogenic arrest is associated with the formation of multinuclear giant cells leading to large scale apoptosis and elimination of germ cells from the seminiferous epithelium. Using this model, the role of HABP1 was examined which expresses stage specifically during spermatogenesis. Cryptorchidism induced complete arrest of spermatogenesis by 2 days and by 3-5 days many large and small multinucleated giant cells populated the affected tubules. Ultra-structure of the giant cells revealed both single and multiple chromatin aggregation, some less compact, distorted and others broken down into tiny fragments. These cells along with other germ cells were stained TUNEL positive demonstrating strong expression of Bax and Heat Shock Protein (hsp) 70. Simultaneously, there was an upregulation of the pro-protein form of HABP1 in these cells and a decrease in the mature form of protein. The above findings indicate a possible role of HABP1 proprotein in apoptosis induction of germ cells in the cryptorchid testes.