Immunomodulation of dendritic cells differentiated in the presence of nicotine with lipopolysaccharide from Porphyromonas gingivalis

Tobacco smoking is a significant risk factor for periodontal diseases. Nicotine, one of the most studied constituents in cigarette smoke, is thought to modify immune responses. Dendritic cells (DCs), which are key mediators between innate and adaptive immunity, stimulate naive T cells to differentiate to effector T‐cell subsets that may be actively involved in the immunopathogenesis of periodontal diseases. In this study, we evaluated the effects of nicotine and lipopolysaccharide (LPS) from Porphyromonas gingivalis, alone and in combination, on the functions of human monocyte‐derived DCs to elucidate the mechanism of tissue destruction of smoking‐associated periodontal diseases. P. gingivalis LPS‐stimulated DCs differentiated with nicotine (NiDCs) induced lower T‐cell proliferation and human leukocyte antigen (HLA)‐DR expression, but elevated expression of programmed cell death ligand 1. Additionally, NiDCs impaired interferon‐γ production but maintained interleukin (IL)‐5 and IL‐10 production in co‐cultured T cells. Furthermore, NiDCs produced lower levels of proinflammatory cytokines compared with DCs differentiated in the absence of nicotine. Interestingly, NiDCs preferentially produced the T helper 2 (Th2)‐type chemokines macrophage chemotactic protein‐1 and macrophage‐derived chemokine. These results suggest that the presence of nicotine during differentiation of DCs modulates the immunoregulatory functions of P. gingivalis LPS‐stimulated DCs.     

Activation of proprotein convertase in the mouse habenula causes depressive-like behaviors through remodeling of extracellular matrix

The lateral habenula (LHb) attracts a growing interest as a regulator of monoaminergic activity which were frequently reported to be defective in depression. Here we found that chronic social defeat stress (CSDS) increased production of pro-inflammatory cytokines in LHb associated with mobilization of monocytes and remodeling of extracellular matrix by increased matrix metalloproteinase (MMP) activity. RNA-seq analysis identified proprotein convertase Pcsk5 as an upstream regulator of MMP activation, with upregulation in LHb neurons of mice with susceptibility to CSDS. PCSK5 facilitated motility of microglia in vitro by converting inactive pro-MMP14 and pro-MMP2 to their active forms, highlighting its role in mobilization of microglia and monocytes in neuroinflammation. Suppression of Pcsk5 expression via small interfering RNA (siRNA) ameliorated depressive-like behaviors and pathological mobilization of monocytes in mice with susceptibility to CSDS. PCSK5-MMPs signaling pathway could be a target for development of the antidepressants targeting the inflammatory response in specific brain regions implicated in depression.Subject terms: Cellular neuroscience, Gene expression analysis     

Elucidation of demographic,clinical and trichoscopic features for early diagnosis of self-healing acute diffuse and total alopecia

The term “acute diffuse and total alopecia” (ADTA) has been often used as a synonym for self-regressing severe alopecia areata (AA). However, ADTA is originally defined as a rapidly-progressive subtype of AA (RP-AA) with short recovery time and favorable prognosis irrespective of interventions. Indeed, a subpopulation of ADTA recovers spontaneously. We focused on this unique subset of AA, which we coined as “self-healing ADTA” (sADTA). Prompt and accurate differentiation of sADTA from other RP-AA is important to avoid unnecessary treatments, which is still challenging due to the lack of predictive diagnostic hallmarks. In this study, 18 sADTA patients were retrospectively analyzed to delineate their demographics and clinical features, including gentle hair pull test and trichoscopic findings, followed by statistical comparison with those of RP-AA. All sADTA cases were female and the average age was 38.1 ± 15.9 years. The progression of hair loss areas peaked at 3.6 ± 1.5 months, and complete hair regrowth was achieved in 7.9 ± 1.7 months. The identified factors supporting the diagnosis of sADTA included being female; the absence of scalp pain and itch; the absence of extra-scalp hair loss; club hair predominance in hair pull test; predominant short vellus hairs; and increase in vacant follicular ostia on trichoscopy. Subsequently, a scoring system for early diagnosis of sADTA was developed by counting the number of six identified factors present in a tested case. When analyzed by the developed system, all sADTA cases, including an additional four cases, had scores of 4 or above, while all RP-AA cases had scores below 3 except one case. Therefore, the system successfully differentiated sADTA from RP-AA (P < 0.01). Despite some technical limitations, the current study suggested that sADTA is a distinctive entity with unique pathophysiology and that early diagnosis before intervention is feasible based on the characteristics.     

Comparing treatments for basal cell carcinoma in terms of long‐term treatment‐failure: a network meta‐analysis

Although many variations of guidelines have been released, there is limited research that compares multiple treatment strategies for basal cell carcinoma (BCC). The aim of this study was to systematically review the studies reporting on multiple treatments for BCC with systematic review and network meta‐analyses. Search formulas for databases, such as PubMed, EMBASE, Web of Science Core Collection and Cochrane Central Register of Controlled Trials, were created with the support of Cochrane Japan. The patient‐level and tumour‐level meta‐analyses were performed for both the long‐term treatment‐failure and treatment‐success. Of the 1464 studies identified from the database and hand searches, 14 met our inclusion criteria. These 14 studies included 2524 patients and 1738 tumours. Our study indicated that the incidence of treatment‐failure of invasive treatments such as surgery and Mohs micrographic surgery was significantly lower than that of superficial therapies such as cryotherapy, photodynamic therapy, radiotherapy or topical therapies, in the patient‐level and the tumour‐level analyses, despite histological‐type and pretreatment. Relapse of BCC may be a low life‐threatening risk, and there are merits of non‐surgical treatment. However, the significant difference in the recurrence rate is essential. Our study can provide useful guidance to clinicians in selecting treatment options for BCC.