Requirement of the F‐actin‐binding activity of l‐afadin for enhancing the formation of adherens and tight junctions

The apical junctional complex consists of adherens junctions (AJs) and tight junctions (TJs) in polarized epithelial cells, which are attached to each other to form a sheet. Actin filaments (F‐actin) are associated with AJs and TJs and required for the formation and maintenance of this complex. l‐Afadin is an F‐actin‐binding protein, which is localized at AJs through binding to the cell adhesion molecule nectin, and regulates the formation of AJs and TJs. However, the role of the F‐actin‐binding activity of l‐afadin for the formation of the apical junctional complex remains unknown. We generated here the cultured EpH4 mouse mammary epithelial cells in which afadin was genetically ablated. In the Ca²⁺ switch assay, the formation of both AJs and TJs was markedly impaired in the afadin‐deficient cells. Re‐expression of l‐afadin in the afadin‐deficient cells fully restored the formation of both AJs and TJs, but the re‐expression of the l‐afadin mutant lacking the FAB domain did not completely restore the formation of AJs or TJs. These results indicate that the F‐actin‐binding activity of l‐afadin is required for enhancing the formation of both AJs and TJs.     

Cytoplasmic Maspin Expression Correlates with Poor Prognosis of Patients with Adenocarcinoma of the Uterine Cervix

Background

Maspin is known to be a tumor suppressor protein and its prognostic significance in patients with several types of cancer has been reported. To date, however, no study has focused on the association between maspin expression and the prognosis of patients with adenocarcinoma of the uterine cervix. We explored the prognostic value of maspin expression with particular reference to its subcellular localization in patients with adenocarcinoma of the uterine cervix.

Methods

Paraffin-embedded tissue samples from 46 patients diagnosed as adenocarcinoma of the uterine cervix were immunohistochemically analyzed using an antibody for maspin. The patients were followed up for 3 to 165 months (median: 64.2 months) and the prognostic value was evaluated by the log-rank test and the Cox regression hazard model.

Results

A sample was considered maspin-positive if maspin was expressed in only the cytoplasm; 69.6% (32 cases) of the specimens were maspin-positive, and there was significant correlation between positivity and recurrence (P = 0.022). Maspin-positive patients had both shorter disease free survival and shorter overall survival by the log-rank test (P = 0.023, P = 0.043, respectively). By Cox’s multivariate analysis, the International Federation of Obstetrics and Gynecology (FIGO) status was the only independent prognostic factor for disease free survival and overall survival in patients with adenocarcinoma of the uterine cervix.

Conclusion

This is the first report to reveal an association between cytoplasmic maspin expression and the prognosis of patients with adenocarcinoma of the uterine cervix. Although further studies with a larger series of patients and a longer follow up period are necessary, the present results suggest that cytoplasmic maspin expression could be an indicator of unfavorable prognosis in patients with adenocarcinoma of the uterine cervix.     

Implication of core beliefs about negative-self in neuroticism

Abstract

Objective: Core beliefs about negative-self are beliefs about self-deficiencies in basic aspects of human adaptation. Meanwhile, neuroticism is a personality trait characterised by negative emotionality, i.e., a tendency to react to stress with negative emotions. The present study tested the hypothesis that core beliefs about negative-self are implicated in neuroticism.

Methods: The subjects were 309 Japanese healthy volunteers. Core beliefs about negative-self were evaluated by the Brief Core Schema Scales, and neuroticism was evaluated by the NEO Personality Inventory-Revised.

Results: In both multiple regression analysis and structural equation modelling, higher neuroticism was strongly predicted by higher levels of core beliefs about negative-self.

Limitations: The present study cannot determine the causal relationship between core beliefs about negative-self and neuroticism, because of its cross sectional design.

Conclusions: The present study suggests that core beliefs about negative-self are deeply implicated in neuroticism.

• Key Points

• Implication of core beliefs about negative-self in neuroticism was examined.

• Neuroticism was predicted by higher levels of these core beliefs.

• These core beliefs may be involved in negative emotionality of neuroticism.

     

Aging‐dependent expression of synapse‐related proteins in the mouse brain

A synapse is a cell adhesion structure that permits a neuron to pass a chemical or electrical signal to another neuron. They connect neurons and form neural networks that are essential for brain functions, such as learning and memory. At a chemical synapse, the presynapse and the postsynapse are connected by cell adhesion molecules. The presynapse contains synaptic vesicles and their release machinery, whereas the postsynapse contains postsynaptic densities and receptors for the neurotransmitters. Many proteins constituting a synapse have been identified, but their life‐span expression profiles remain elusive. Here, we investigated the expression levels of representative synapse‐related proteins by Western blot using the extranuclear supernatant fraction of the brains of mice at various ages. These proteins were classified into seven groups depending on their expression profiles during the embryonic stage, those from postnatal day 6 (P6) to P30, and those after P90. The expression levels of the majority of the proteins were gradually increased from the embryonic stage and then decreased at P14 or P30. After P90, the expression levels were not markedly changed or, in some proteins, increased. These results indicate that the expression levels of the synapse‐related proteins are regulated orderly in an aging‐dependent manner.     

NGL‐3‐induced presynaptic differentiation of hippocampal neurons in an afadin‐dependent,nectin‐1‐independent manner

A hippocampal mossy fiber synapse, which is implicated in learning and memory, has a complex structure. We have previously shown using afadin‐deficient mice that afadin plays multiple roles in the structural and functional differentiations of this synapse. We investigated here using a co‐culture system with cultured hippocampal neurons and non‐neuronal COS‐7 cells expressing synaptogenic cell adhesion molecules (CAMs) whether afadin is involved in the presynaptic differentiation of hippocampal synapses. Postsynaptic CAMs NGL‐3 (alias, a Lrrc4b gene product) and neuroligin induced presynaptic differentiation by trans‐interacting with their respective presynaptic binding CAMs LAR (alias, a Ptprf gene product) and neurexin. This activity of NGL‐3, but not neuroligin, was dependent on afadin, but not the afadin‐binding presynaptic CAM nectin‐1. The afadin‐binding postsynaptic CAM nectin‐3 did not induce presynaptic differentiation. Immunofluorescence and immunoelectron microscopy analyses showed that afadin was localized mainly at puncta adherentia junctions, but partly at synaptic junctions, of the mossy fiber synapse. β‐Catenin and γ‐catenin known to bind to LAR were co‐immunoprecipitated with afadin from the lysate of mouse brain. These results suggest that afadin is involved in the NGL‐3‐LAR system‐induced presynaptic differentiation of hippocampal neurons cooperatively with β‐catenin and γ‐catenin in a nectin‐1‐independent manner.     

Correlations between both the expression levels of inflammatory mediators and growth factor in medial perimeniscal synovial tissue and the severity of medial knee osteoarthritis

An enhanced expression of the inflammatory mediators in the perimeniscal synovium in knee osteoarthritis (OA) has been suggested to contribute to progressive cartilage degeneration. However, whether the expression levels of these molecules correlated with the severity of OA still remained unclear. Medial perimeniscal synovial samples were obtained from 23 patients with Kellgren-Lawrence (K/L) grades 2 to 4 of medial knee OA. Immunohistochemical analysis of the synovium revealed that the MMP-1, COX-2 and IL-1β expression of the patients with K/L 4 to be significantly reduced in comparison to those with either K/L 2 or 3, while the TGF-β expression showed the opposite. The synovial expression of MMP-1 and IL-1β showed a significant negative correlation with the severity of OA, while that of TGF-β again showed the opposite. In conclusion, although synovial inflammation remained active, the MMP-1, COX-2 and IL-1β expression in synovium decreased depending upon the severity of OA, while the TGF-β expression increased.