title: Expression of Hsf1, Hsf2, and Phlda1 in cells undergoing cryptorchid-induced apoptosis in rat testes.
abstract: Surgery-induced cryptorchidism, in which the testes are prevented from descending into the scrotal sac, results in testicular germ cell death, and it is commonly used as an experimental tool in the study of spermatogenesis. However, the molecular events underlying the activation of germ cell death remain poorly understood. In the present study, we investigate selective cell loss from cryptorchid rat testis by using DNA flow cytometry and by determining protein and mRNA expression of Hsf1, Hsf2, and Phlda1. The hypo-haploid cell fraction is significantly decreased as early as 3 days after surgical induction of cryptorchidism (from 42.01 ± 5.74% to 15.98 ± 3.88%), followed by a significant decrease in the haploid cell fraction at Day 7. At the latter time point, an apoptotic peak of spermatocytes appears in DNA histograms just before the tetraploid peak; the percentage of aneuploid cells between diploid and tetraploid rises as high as 14.05 ± 2.98% of the total cells in 7-day cryptorchid testis, suggesting that a large number of spermatocytes are undergoing apoptosis. The expression of Phlda1 mRNA is significantly elevated 3 days after induction of cryptorchidism. After 7 days of cryptorchidism, Hsf1 and Phlda1 are strongly expressed in the nucleus and cytoplasm, respectively, of primary spermatocytes. Numerous apoptotic spermatocytes are also observed at this time point. These results suggest that the Hsf1/Phlda1 pathway plays an important role in the apoptosis of primary spermatocytes in cryptorchid testis. We present evidence suggesting that Hsf2 is also involved in germ cell removal in cryptorchid testis.
authors.affiliation: Department of Anatomy, Histology and Embryology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Zeng-Lu
authors.initials: ZL
authors.lastname: Xu
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Qian
authors.forename: Wen-Ying
authors.initials: WY
authors.lastname: Qiu
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D003456:Cryptorchidism / Q000209:etiology / Q000235:genetics / Q000503:physiopathology; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004195:Disease Models, Animal; D005434:Flow Cytometry; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013090:Spermatocytes / Q000473:pathology / Q000502:physiology*; D013091:Spermatogenesis / Q000502:physiology; D013737:Testis / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D057891:Tetraploidy; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; C000619709:Hsf1 protein, rat; C568775:Hsf2 protein, rat; C568776:Phlda1 protein, rat; D014157:Transcription Factors