Menin mediates Tat-induced neuronal apoptosis in brain frontal cortex of SIV-infected macaques and in Tat-treated cells.

The molecular mechanisms involved in human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) remain poorly understood. It has been recently reported that HIV-1 Tat transactivation requires menin, suggesting that menin may be involved in HAND pathogenesis. But the role of menin is not clear. Here, we found that protein level of menin was increased in simian-human immunodeficiency chimeric virus (SHIV)-SF162.P4 and simian immunodeficiency virus (SIV) sm543-3-infected rhesus macaques compared with the controls by immunohistochemistry (IHC) and western blot. Menin mainly expressed in the frontal cortex neurons of the brain, more importantly, the number of menin-staining cells was positively correlated with cleaved-caspase-3-positive cells while it was negatively correlated with a neuron-specific nuclear protein NeuN-positive cells, suggesting that expression of menin may induce neuronal apoptosis. Further studies showed that menin level was significantly increased during Tat-induced apoptosis, while downregulation of menin by pll3.7-MEN1-shRNA attenuated the Tat-induced cleavage of caspase-3 and caspase-8 in SY5Y cells and primary neuron cultures. Together, our findings reveal a pro-apoptotic role of menin in the brains of the SIV-infected macaques and the cultured neurons, indicating that targeting menin may be potential to block the HIV-1 Tat induced neuronal damage in HAND.

Epitope selection to male specific antigens for sex selection in swine.

Immunological approaches to gender selection have been contemplated since the discovery of the family of male-specific H-Y antigens found only on the surface of male cells. H-Y antigens are able to elicit an immune reaction when cells or tissues from a male donor are grafted to a female recipient. We describe here the development and testing of an inexpensive approach using polyclonal antibodies against four specific H-Y outer membrane proteins male enhanced antigen 1 (MEA 1), male enhanced antigen 2 (MEA 2), sex determining region Y (SRY) and testis determining factor (TDF). Epitopes based on hydrophilic primary sequences of the proteins were synthesized, N-terminal biotin-labeled, linked to streptavidin and mixed with a Ribi adjuvant prior to immunization in rabbits. The antiserum was tested to determine affinity to swine spermatozoa using anti-motility, flow cytometry and motility and sedimentation chambers. Fluorescent microscopy and fluorescent in situ hybridization (FISH) was used to identify the percentage of motile spermatozoa that contained the Y chromosome. We found that the polyclonal antibodies had high affinity to the spermatozoa leading to a cessation of motility. Furthermore, the majority of these non-motile spermatozoa contained the Y chromosome. We conclude that the use of polyclonal antiserum against synthetic H-Y peptide antigens may be an inexpensive and simple means to inhibit the motility of swine spermatozoa bearing the Y chromosome.

Multifunctional cells in human pituitary adenomas: implications for paradoxical secretion and tumorigenesis.

Pituitary adenomas are very common in humans. They are of monoclonal origin, very heterogeneous, and produce frequently paradoxical secretion. The normal anterior pituitary (AP) contains some unorthodox multifunctional cells able to store more than one AP hormone (polyhormonal) and/or to express multiple hypothalamic-releasing hormone receptors (multiresponsive). Multifunctional AP cells seem to be involved in plasticity processes such as transdifferentiation or paradoxical secretion. Here, we have characterized the single-cell phenotypes of 15 human pituitary tumors, including prolactinomas, nonfunctioning adenomas, and adenomas from multiple endocrine neoplasia type I (MEN-I) and pituitary Cushing's disease patients. Individual tumor cells were typed according to expression of AP hormones and hypothalamic-releasing hormone receptors by combination of calcium imaging and multiple sequential immunocytochemistry in the same cells. We found a large heterogeneity among the different tumors. In eight of the 15 tumors studied, more than 80% of the cells presented a multifunctional phenotype. This may explain the occurrence of paradoxical secretion. In addition, our results suggest that human pituitary adenomas might derive from multifunctional cells. This is consistent with the existence of a link between pituitary plasticity and tumorigenesis.