Epidermal loss of Bcl6 exacerbates MC903-induced atopic dermatitis-like skin inflammation.

Atopic dermatitis (AD) is a chronic inflammatory skin disease where Th2-type immune responses are dominant. In the lesional skin of AD, keratinocytes show differentiation defects and secrete proinflammatory cytokines and chemokines, amplifying Th2-type responses in AD. We previously reported that inducible loss of B-cell lymphoma 6 (Bcl6), a transcription repressor and a master transcriptional regulator of follicular helper T cells and germinal center B cells, in the whole body results in upregulation of Th2-related cytokines in mouse skin. However, the role of Bcl6 in keratinocytes remains to be clarified. Here, we observed that BCL6 positively regulates the expression of keratinocyte differentiation markers and plasma membrane localization of adherence junctional proteins in keratinocyte cell culture. Although keratinocyte-specific loss of Bcl6 alone did not induce AD-like skin inflammation, it aggravates MC903-induced AD-like skin inflammation in mice. In addition, Bcl6 expression is decreased in the epidermis of lesional skin from MC903-induced AD-like skin inflammation in mice. These results strongly suggest that Bcl6 downregulation in keratinocytes contributes to the development and aggravation of AD-like skin inflammation in mice.

Ethylenediaminetetraacetic acid (EDTA) enhances cAMP production in human TDAG8-expressing cells.

Ethylenediaminetetraacetic acid (EDTA) is a chelating agent that binds tightly to metal ions. We found that cAMP response element (CRE)-driven promoter activity by protons was enhanced by EDTA in human T-cell death-associated gene 8 (TDAG8)-overexpressed HEK293T cells. The enhancing action by EDTA was also detected by proton-induced cAMP production that is located upstream from the CRE-driven promoter activity even at physiological proton concentration pH7.4. The proton-induced CRE-driven promoter activity was not enhanced by other chelating agents, ethylene glycol tetraacetic acid (EGTA) and sodium citrate. The enhanced CRE-driven promoter activity by EDTA was not attenuated by increasing the extracellular calcium ion concentration. These results indicate that the EDTA-enhancing action may not be due to its chelating action but might rather be another EDTA-specific effect. Enhanced cAMP production by EDTA was also detected in a human leukemia cell line HL-60, in which TDAG8 and OGR1 (ovarian cancer G-protein-coupled receptor 1) were endogenously expressed, suggesting that the medical use of EDTA would influence the physiological and pathophysiological functions of hematopoietic cells.

[Effects of polypharmacy and anticholinergic/sedative drugs on the physical/cognitive/mental related outcomes of community-dwelling elderly people: The Kawasaki Wellbeing Project].

AIM: To assess the burdens of polypharmacy and the drug burden index in community-dwelling elder people. METHODS: The survey was conducted on 396 participants who participated in The Kawasaki Wellbeing Project from March to December 2017. We investigated the associations between the drug burden and the physical/cognitive/mental outcomes. The drug burden was determined by calculating the number of medications and the drug burden index (DBI) based on the use of anticholinergic and sedative drugs. A multivariate regression analysis was conducted for the outcome measures ADL, IADL, MMSE, J-CHS, and EQ5D5L after adjusting for the sex, age, number of diseases, education level, smoking history, and alcohol history. RESULTS: A total of 389 subjects were analyzed, the mean age of the population was 86 years old, and 187 people (48%) were male. Polypharmacy was reported in 243 people (62%), and DBI exposure was reported for 142 people (36.5%). We found that this population was physically healthy, with a median ADL of 100, and had high quality of life, with a median EQ5D5L of 0.895. Polypharmacy was found to be related to the J-CHS (ß: 0.04) and EQ5D5L (-0.01). The DBI was also related to the EQ5D5L (-0.04). CONCLUSION: These results showed that even though this population was healthier than the general Japanese elderly population, the drug burden of polypharmacy and high dosages of anticholinergic/sedative drugs exerted significant negative effects on frailty and the quality of life. Additional research should be conducted to investigate the long-term effects of polypharmacy and anticholinergic/sedative drugs on elderly people.

Development of a direct point electron beam exposure system to investigate the biological functions of subcellular domains in a living biological cell.

Electron microscopy studies have demonstrated that the diameter of a focused electron beam is small enough to probe or manipulate subcellular domains of a single biological cell. Here, we report the development of a direct point electron beam irradiation system to investigate the biological functions of subcellular domains in a living cell. Subcellular structures of a single living cell cultured on a thin film can be selectively irradiated by the point electron beam generated by our system. We have demonstrated controlled beam positioning capability to selectively irradiate 500 nm size structure with a point electron beam. We determined beam irradiation parameters that did not cause irreversible plasma membrane perforation after beam exposure and the irradiation caused intracellular Ca2+ elevation in an irradiated neuronal cell. Since the neuronal cell express fine subcellular structures such as neurites, we tried to position a beam on the structure and observed a Ca2+ wave originated from the intended point, which showed that our system had enough selectivity to target a subcellular structure. Point electron beam exposure is expected to be employed for various cellular stimulation protocols, and this enables the investigation of the biological functions of subcellular domains.