Intercellular communication within the rat anterior pituitary: relationship between LH-RH neurons and folliculo-stellate cells in the pars tuberalis

The distribution of LH-RH-positive nerve fibers in the median eminence was demonstrated in the 1970s and 1980s. A few LH-RH fibers have been reported to be present in the adjacent pars tuberalis of the pituitary, but their functional significance has not been clarified and still remains enigmatic. Adult male Wistar-Imamichi rats were separated into two groups: one for immunohistochemistry of LH-RH and S-100 protein (for the identification of folliculo-stellate cells) and the other for electron microscopy. For both immunohistochemistry and electron microscopy, the specimens obtained contained the pituitary gland connected with the hypothalamus. Numerous LH-RH-positive fibers were observed as tiny lines with several varicosities both on the primary vascular plexus and in the hypothalamus corresponding to the posterior half of the portal vein area. LH-RH-positive fibers were also noted around S-100-positive cells in the pars tuberalis. Weakly reactive S-100 cells were scattered in the pars tuberalis in the midsagittal plane, while clusters of strong reactive elements occurred 100–300 m from the center. Similar observations were made using fluorescence immunohistochemistry for LH-RH and S-100, and at the electron-microscopic level. At the posterior portion of the portal vein system, bundles of the LH-RH-immunoreactive fibers invaded the pars tuberalis and terminated on agranular cells. Gap junctions were clearly seen among agranular cells corresponding to folliculo-stellate cells. It is postulated that the LH-RH message might be transmitted not only by the established hypophyseal portal vein system but also via the folliculo-stellate cells in the pars tuberalis to aid in the modulation of LH release.     

Control of MAP kinase signaling to the nucleus

MAP kinase (MAPK) signaling is among central signaling pathways that regulate cell proliferation, cell differentiation and apoptosis. As MAPK should transmit extracellular signals to proper regions or compartments in cells, controlling subcellular localization of MAPK is important for regulating fidelity and specificity of MAPK signaling. The ERK1/2-type of MAPK is the best characterized member of the MAPK family. In response to extracellular stimulus, ERK1/2 translocates from the cytoplasm to the nucleus by passing through the nuclear pore by several independent mechanisms. Sef (similar expression to fgf genes), a transmembrane protein, has been shown to be a regulator of subcellular distribution of ERK1/2. Sef binds to activated MEK1/2, the specific activator of ERK1/2, and tethers the activated MEK1/2/activated ERK1/2 complex to the Golgi apparatus and the plasma membrane. Thus, Sef blocks ERK1/2 signaling to the nucleus and allows signaling to the cytoplasm. Here we review recent findings on spatial regulation of MAPK, especially on nucleocytoplasmic trafficking of ERK1/2.     

Mode of action of cellulases on dyed cotton with a reactive dye

Cotton woven fabrics which were previously dyed with a reactive dye were treated with a commercial cellulase preparation. Dyeing with a reactive dye for cotton apparently inhibited the weight loss activity and saccharification activity of cellulase. In addition, dyed cotton was treated with highly purified cellulases which were exo-type cellulases (Cellobiohydrolase I (CBH I) and Cellobiohydrolase II (CBH II)) and endo-type cellulase (Endoglucanase II (EG II)). Exo-type cellulases were inhibited more than endo-type cellulase by dyeing in the case of saccharification activity. CBH I was severely inhibited by dyeing as compared with CBH II or EG II from the viewpoint of morphological changes in the fiber surface. Dyes on the cellulose substrates severely influenced CBH I in spite of the rare modification, because CBH I hydrolyzed cellulose with true-processive action. The change in the activity of each cellulase component on dyed cotton can affect the synergistic action of cellulases.     

HB-EGF promotes epithelial cell migration in eyelid development

Heparin-binding EGF-like growth factor (HB-EGF) is a member of the EGF family of growth factors that binds to and activates the EGF receptor (EGFR) and ERBB4. Here, we show that HB-EGF-EGFR signaling is involved in eyelid development. HB-EGF expression is restricted to the tip of the leading edge of the migrating epithelium during eyelid closure in late gestation mouse embryos. Both HB-EGF null (HB(del/del)) and secretion-deficient (HB(uc/uc)) mutant embryos exhibited delayed eyelid closure, owing to slower leading edge extension and reduced actin bundle formation in migrating epithelial cells. No changes in cell proliferation were observed in these embryos. In addition, activation of EGFR and ERK was decreased in HB(del/del) eyelids. Crosses between HB(del/del) mice and waved 2 mice, a hypomorphic EGFR mutant strain, indicate that HB-EGF and EGFR interact genetically in eyelid closure. Together with our data showing that embryos treated with an EGFR-specific kinase inhibitor phenocopy HB(del/del) embryos, these data indicate that EGFR mediates HB-EGF-dependent eyelid closure. Finally, analysis of eyelid closure in TGFalpha-null mice and in HB-EGF and TGFalpha double null mice revealed that HB-EGF and TGFalpha contribute equally to and function synergistically in this process. These results indicate that soluble HB-EGF secreted from the tip of the leading edge activates the EGFR and ERK pathway, and that synergy with TGFalpha is required for leading edge extension in epithelial sheet migration during eyelid closure.     

Intercellular communications within the rat anterior pituitary XI: an immunohistochemical study of distributions of S-100 positive cells in the anterior pituitary of the rat

The distribution of the S-100 protein cell (folliculo-stellate cell) is very important to our understanding of the regulation of the anterior pituitary. In this study, 10 intact 60-day-old male Wistar-Imamichi rats, were separated equally into two groups. One was used for immunohistochemical study, and the other for electron microscopic analysis. Immunostained pituitary sections with S-100 protein antibody were photographed using a CCD camera equipped with a computer. The S-100 protein cells were then measured using NIH image software, and the three-dimensional distribution of the cells was analyzed. The distribution of the cells observed in each serial section showed that S-100 protein cells were dense at the basal zone of the gland and at the "transitional zone" where the pars tuberalis adjoined the anterior and intermediate lobes, where they represented over 50% of the total cell population. They then decreased in number with distance from this region to mid-way towards the sagittal axis before increasing again in the tail of the gland. The population of cells also decreased with increasing distance from the "transitional zone" to the wing and with distance from the basal zone. Portal vessels entered the anterior lobe through the "transitional zone" as thick capillaries, ran through the basal surface and penetrated into the central area of the anterior lobe. In all planes, S-100 protein cells encircled the capillaries. Ultrastructural observations confirmed the light microscopic findings indicating that clusters of agranular cells were densely located at the "transitional zone" and in the pars tuberalis. The distribution pattern of the folliculo-stellate cells and the capillaries showed good agreement and the spatial relationship between these two is detailed so as to better understand hypophyseal histophysiology.     

The type III secretion system-dependent repression of NF-kappaB activation to the intracellular growth of Edwardsiella tarda in human epithelial cells.

Edwardsiella tarda is a pathogen with a broad host range infecting animals and humans. We have reported recently that the type III secretion system (TTSS) is essential for intracellular replication of the bacterium in murine macrophages. The present study shows that the TTSS is also needed for intracellular growth of the bacterium in human epithelial cells (HEp-2). However, different from the previous microarray analyses on murine macrophages, upregulation of the mRNA expression level of NF-kappaB target genes was not detected in the infected HEp-2 cells. The wild-type E. tarda, but not its TTSS mutant, actually repressed the tumor necrosis factor alpha-dependent NF-kappaB activation in an NF-kappaB reporter gene assay. These results suggest TTSS-dependent repression of the NF-kappaB activation in HEp-2 cells infected with E. tarda.     

Estimating the maximum sustainable yield of snow crab (Chionoecetes opilio) off Tohoku,Japan via a state-space stock assessment model with time-varying natural mortality

A maximum sustainable yield (MSY) obtained by maintaining or restoring fish stock levels is a tangible benefit of ecosystem services. Snow crab (Chionoecetes opilio) off Tohoku, Japan has been managed by a total allowable catch since 1996, although the abundance has not increased. Surprisingly, there was no increase after 2011, when fishing pressure was greatly reduced because of the Great East Japan earthquake. This implies that some of the crab's biological characteristics, such as recruits, natural mortality coefficient (M) and terminal molting probabilities (p), might have changed. We developed “just another state-space stock assessment model” to estimate the MSY of the snow crab off Tohoku considering interannual variations in M and p. The multimodel inference revealed that M increased from 0.2 in 1997 to 0.59 in 2018, although it did not vary according to instars, sex or terminal molt. The parameter p also increased by 1.34–2.46 times depending on the instar growth stages from 1997 to 2018. We estimated the MSYs in three scenarios, which changed drastically if M and p were set as they were in the past or at the current values estimated from this study. This result indicated that the MSY of snow crab would also vary with time based on their time-varying biological characteristics.     

Women’s Preference for a Male Acquaintance Enhances Social Reward Processing of Material Goods in the Anterior Cingulate Cortex

Men, like the male of many animal species, use gifts to build satisfactory relationships with a desired woman. From the woman’s perspective, all gifts are not always equally rewarding; the reward value of a gift depends on two factors: (1) the giver and (2) the type of the gift (the gift’s social meaning). In this study, we investigated how these two factors interactively determine the reward value of a gift. Specifically, we examined how the neural processing for understanding a gift’s social meaning is modulated by preferences for the giver. We performed a functional magnetic resonance imaging (fMRI) study in which a female participant was asked to judge a gift from a male she was acquainted with in real life. We examined the interactive effects between (1) the female participant’s attitude toward the male acquaintance (liked vs. uninteresting) and (2) the type of the gift (romantic [e.g., bouquet, earrings, and perfumes] vs. non-romantic [e.g., pencils, memo pad, and moneybox]). We found that preference for an acquaintance selectively modulated activity in the anterior cingulate cortex (ACC) in response to romantic gifts, compared to non-romantic gifts. In contrast, if the woman was indifferent toward an acquaintance, no activity modulation was observed in this area for the same gifts. In addition, the ACC showed functional connectivity with the supplementary motor area/dorsal ACC (SMA/dACC), an area within the dorsal mediofrontal cortex, suggesting that it integrates action monitoring and emotional and cognitive processing in decision-making. These results suggest that attitude toward an opposite sex member has a modulatory role in recognizing the social meaning of material goods—preference for the member is a powerful modulator of social reward processing.