Immunohistochemical study of galectin-3 in mature and immature bull testis and epididymis.

Galectin-3, a member of the beta-galactoside-binding protein family, has been implicated in mammalian sperm maturation. We examined galectin-3 expression in the testis and epididymis of sexually mature and immature bulls. Western blot analysis showed varying levels of galectin-3 in the bull testis and epididymis, and galectin-3 immunoreactivity was higher in the mature testis and epididymis than in immature organs. Galectin-3 was primarily localized in interstitial cells of the immature bull testis and in the peritubular myoid and interstitial cells of the mature testis. In the immature epididymis head, galectin-3 was primarily in the principal and basal cells of the epithelium. In the mature epididymis head, moderate levels of galectin-3 were detected in the sperm, while low levels were found in the stereocilia, epithelium and connective tissue. In the immature epididymis body, moderate protein levels were detected in the principal cells, while lower levels were found in the basal cells. The mature epididymis body showed moderate levels of galectin-3 immunostaining in the stereocilia and epithelium, but low levels in the connective tissue. In the immature epididymis tail, only low levels of galectin-3 staining were found in the epithelium, whereas the mature epididymis tail showed high levels of galectin-3 in the principal cells, moderate levels in the basal cells and low levels in connective tissue. These findings suggest that galectin-3 expression plays a role in the maturation and activation of sperm in bulls.

Immunohistochemical localization of galectin-3 in the reproductive organs of the cow.

The protein levels and immunohistochemical localization of galectin-3, which is a beta-galactoside-binding protein, were studied in the cow reproductive organs. Using Western blot analysis, galectin-3 was detected at low levels in the ovary and oviduct, at moderate levels in the uterus, and at high levels in the cervix. Using immunohistochemistry, galectin-3 was immunolocalized in macrophages in the interstitium, in cells in the atretic follicles, and in luteal cells in the regressing corpus luteum, but not in the growing follicles in the ovary. In the oviduct, galectin-3 was detected in some macrophages in the lamina propria, submucosa and muscle layers, as well as in some cells in the covering epithelium. In the uterus, galectin-3 was immunolocalized in some epithelial cells and in some macrophages in the submucosa, but not in the endometrial glands at the non-pregnant stage. In the cervix, galectin-3 was immunolocalized in many mucus-secreting cells in the mucosa and in a few macrophages in the submucosa and muscle layers. Based on its localization, we postulate that galectin-3 in the covering epithelium is involved in the mucosal defense system, and that galectin-3-positive macrophages in all tissues are involved in either cell survival or death. In addition, galectin-3 plays an important role in the regression of follicles and the corpus luteum.

Expression of nitric oxide synthase isoforms in the porcine ovary during follicular development.

The expression of nitric oxide synthase (NOS) isoforms in the ovaries of pigs was examined to study the involvement of nitric oxide, a product of NOS activity, in the function of the ovary. Western blot analysis detected three types of NOS in the ovary, including constitutive neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS); eNOS immunoreactivity was more intense compared with that of iNOS or nNOS. Immunohistochemical studies demonstrated the presence of nNOS and eNOS in the surface epithelium, stroma, oocytes, thecal cells, and endothelial cells of blood vessels. Positive immunoreactions for nNOS and iNOS were detected in the granulosa cells from multilaminar and antral follicles, but not in those of unilaminar follicles. iNOS was detected in the surface epithelium, oocytes, and theca of multilaminar and antral follicles. Taking all of the findings into consideration, the observed differential expression of the three NOS isoforms in the ovary suggests a role for nitric oxide in modulating reproduction in pigs.

Upregulation of phospholipase D1 in the spinal cords of rats with clip compression injury.

This study examined phospholipase D 1 (PLD1) expression in the central nervous system following clip compression spinal cord injury (SCI) in Sprague-Dawley rats. After inducing SCI with a vascular clip, the expression of PLD1 in the affected spinal cord was analyzed by Western blot and immunohistochemistry. Western blot analysis showed that the expression of PLD1 gradually increased in the spinal cord on days 0.5, 1, 2, and 4 post injury. Immunohistochemistry showed that some cells, including neurons, astrocytes, and some inflammatory cells, were positive for PLD1 in the lesions at days 1 and 2 post injury. At day 4, the number of PLD1-positive cells in SCI lesions increased, largely matching the increases in ED1-positive macrophages and glial fibrillary acidic protein-positive astrocytes. At this time, macrophages expressed proliferating cell nuclear antigen in addition to PLD1. These results suggest that PLD1 expression is increased in injured spinal cords, and might be involved in the activation and proliferation of macrophages and astrocytes in SCI.