The expression pattern of the 70-kDa heat shock protein Hspa2 in mouse tissues

Abstract

The highest expression level of a 70-kDa heat shock protein family member Hspa2 is detected specifically in meiotic and post-meiotic male germ cells, which is reflected by original name of this protein, i.e., testis-specific Hsp70. However, this chaperon protein could be also detected in certain somatic tissues. Here, the extra-testicular expression pattern of mouse Hspa2 was analyzed. We found expression of Hspa2 in various epithelial cells including lining of bronchioles and oviduct, columnar epithelium of endometrium, epithelial reticular cells of thymus, transitional epithelium of the urinary bladder, or ependymal cells covering walls of the ventricular system of the brain. Surprisingly, Hspa2 was a putative secretory protein in intestine, endometrial glands and subcommissural organ. Hspa2 was detected in central and peripheral nervous system: in neuron's bodies and fiber tracts, in the subventricular zone of the lateral ventricles, in the dentate gyrus of the hippocampus, in enteric ganglia of the gastrointestinal tract. Hspa2 was also expressed in smooth muscles and at low level in immune system (in germinal centers associated with B-lymphocyte production). In addition to somatic tissues listed above, Hspa2 was detected in oocytes arrested at diplotene of the first meiotic division.

Identification of a new mouse sperm acrosome-associated protein

“…The Hspa2 gene is expressed at a high level in spermatocytes and spermatids (Krawczyk et al 1988), and Hspa2 promoter fragment used in this study (1133-bp long) can drive EGFP reporter gene expression mainly into the testis (Vydra et al 2009). To overcome possible position effects, we introduced insulator sequences from the chicken b-globin locus into the transgene (Recillas-Targa et al 2002).…”

“…Transgenic founders were screened by PCR using genomic DNA isolated from tail biopsies and primers complementary to the Spaca7 and EGFP coding sequences (Table 1). Transgenic mice containing 1133 bp KpnI-DraII fragment of the rat Hspa2 promoter linked to EGFP gene (pHST(1195/62)-EGFPCINS transgene, here designated as pHspa2-EGFP transgene) were described in detail elsewhere (Rupik et al 2006, Vydra et al 2009). The animals were maintained under controlled environmental conditions with a 12 h light:12 h darkness cycle and were …”

Effects of chronic heat stress on the expressions of heat shock proteins 60, 70, 90, A2, and HSC70 in the rabbit testis

“…HSPA2 is developmentally regulated and is specifically expressed in spermatogenic cells. HSPA2 was specifically detected in meiotic and postmeiotic male germ cells, mainly in pachytene spermatocytes and round spermatids (Vydra et al 2009;Wu et al 2011).…”

Extending the knowledge in histochemistry and cell biology

“…The expression pattern of HSPa2 in mouse tissues was addressed by Vydra et al (2009). In accordance to its original name and origin (testis-speciWc HSP70), high amounts of HSPa2 were found in germ cells by Western blotting or immunohistochemical studies.…”