A Study on Project-Based Learning from the Viewpoint of Organizational Knowledge Creation Theory

アクティブラーニングの1 つとしてPBL（problem/project-based learning）がある。PBL には問題解決学習（problem based learning）とプロジェクト学習（project based learning）の2 つがある。これまでPBL を対象とする研究は着実に蓄積されてきたが，PBL の理論的枠組みは未だ脆弱であることが指摘されている。そこで，本研究ではこの問題を克服するために，大学教育でのプロジェクト学習について，組織的知識創造理論から考察する。本研究の第1 の目的は，組織的知識創造理論がプロジェクト学習においても適用できることを確認することである。第2 の目的は，プロジェクト学習における教員の役割について，組織的知識創造理論から示唆を得ることである。本研究では，以下の3 ステップを踏む。まず，本研究の鍵概念である組織的知識創造理論を紹介する。次に，3 つのプロジェクト学習の事例を紹介し，組織的知識創造理論から分析する。最後に，組織的知識創造理論がプロジェクト学習においても適用できることについて，また，示唆されたプロジェクト学習における教員の役割について議論する。One form of active learning is PBL. There are two types of PBL: “problem-based learning” and “project-based learning.” Although a large number of studies have been on PBL, few studies have been conducted using surveys based on academic theories. Therefore, this paper discusses “project-based learning” from the viewpoint of organizational knowledge creation theory. The primary objective of this study is to apply organizational knowledge creation theory in the field of “project-based learning.” The secondary objective is to recommend teachers’ roles in “project-based learning” from the standpoint of organizational knowledge creation theory. The analysis includes three steps: first, a review of organizational knowledge creation theory; second, an examination of three case studies; and finally, a discussion on applying the theory to “project-based learning”, and suggesting teachers’ roles from this viewpoint

Association of circulating exosomal miR-122 levels with BAT activity in healthy humans

Brown adipose tissue (BAT) plays an important role in body fat accumulation and the regulation of energy expenditure. Since the role of miRNAs in the pathogenesis of obesity and related metabolic diseases is contentious, we analyzed exosomal miRNAs in serum of healthy subjects with special references to BAT activity and body fat level. Forty male volunteers aged 20-30 years were recruited. Their BAT activity was assessed by fluorodeoxyglucose positron emission tomography and computed tomography after 2 h of cold exposure and expressed as a maximal standardized uptake value (SUVmax). Exosomal miRNA levels was analyzed using microarray and real-time PCR analyses. The miR-122-5p level in the high BAT activity group (SUV >= 3) was 53% lower than in the low BAT activity group (SUVmax <3). Pearson's correlation analysis revealed that the serum miR-122-5p level correlated negatively with BAT activity and the serum HDL-cholesterol, and it correlated positively with age, BMI, body fat mass, and total cholesterol and trig lyceride serum levels. Multivariate regression analysis revealed that BAT activity was associated with the serum miR-122-5p level independently of the other parameters. These results reveal the serum exosomal miR-122-5p level is negatively associated with BAT activity independently of obesity

Adipocytes and Stromal Cells Regulate Brown Adipogenesis Through Secretory Factors During the Postnatal White-to-Brown Conversion of Adipose Tissue in Syrian Hamsters

Brown adipose tissue (BAT) is a specialized tissue that regulates non-shivering thermogenesis. In Syrian hamsters, interscapular adipose tissue is composed primarily of white adipocytes at birth, which is converted to BAT through the proliferation and differentiation of brown adipocyte progenitors and the simultaneous disappearance of white adipocytes. In this study, we investigated the regulatory mechanism of brown adipogenesis during postnatal BAT formation in hamsters. Interscapular adipose tissue of a 10-day-old hamster, which primarily consists of brown adipocyte progenitors and white adipocytes, was digested with collagenase and fractioned into stromal-vascular (SV) cells and white adipocytes. SV cells spontaneously differentiated into brown adipocytes that contained multilocular lipid droplets and expressed uncoupling protein 1 (Ucp1), a marker of brown adipocytes, without treatment of adipogenic cocktail such as dexamethasone and insulin. The spontaneous differentiation of SV cells was suppressed by co-culture with adipocytes or by the addition of white adipocyte-conditioned medium. Conversely, the addition of SV cell-conditioned medium increased the expression of Ucp1. These results indicate that adipocytes secrete factors that suppress brown adipogenesis, whereas SV cells secrete factors that promote brown adipogenesis. Transcriptome analysis was conducted; however, no candidate suppressing factors secreted from adipocytes were identified. In contrast, 19 genes that encode secretory factors, including bone morphogenetic protein (BMP) family members, BMP3B, BMP5, and BMP7, were highly expressed in SV cells compared with adipocytes. Furthermore, the SMAD and MAPK signaling pathways, which represent the major BMP signaling pathways, were activated in SV cells, suggesting that BMPs secreted from SV cells induce brown adipogenesis in an autocrine manner through the SMAD/MAPK signaling pathways. Treatment of 5-day-old hamsters with type I BMP receptor inhibitor, LDN-193189, for 5 days reduced p38 MAPK phosphorylation and drastically suppressed BAT formation of interscapular adipose tissue. In conclusion, adipocytes and stromal cells regulate brown adipogenesis through secretory factors during the postnatal white-to-brown conversion of adipose tissue in Syrian hamsters

Positive Effects of Oral Antibiotic Administration in Murine Chronic Graft-Versus-Host Disease

Chronic graft-versus-host disease (cGVHD) is one of the most frequent complications experienced after allogeneic hematopoietic stem cell transplantation. Reportedly, dysbiosis and severe damage to the microbiome are also closely associated with GVHD. Herein, we aimed to elucidate the positive and negative effects of the administration of various antibiotics in a murine model of cGVHD. For allogeneic bone marrow transplantation (allo-BMT), bone marrow from B10.D2 mice were transplanted in BALB/c mice to induce cGVHD. The cGVHD mice were orally administered ampicillin, gentamicin (GM), fradiomycin, vancomycin, or the solvent vehicle (control group). Among the antibiotic-treated mice, the systemic cGVHD phenotypes and ocular cGVHD manifestations were suppressed significantly in GM-treated mice compared to that in control mice. Inflammatory cell infiltration and fibrosis in cGVHD-targeted organs were significantly attenuated in GM-treated mice. Although regulatory T cells were retained at greater levels in GM-treated mice, there were significantly fewer Th17 cells and interleukin (IL)-6-producing macrophages in cGVHD-targeted organs in these mice. Collectively, our results revealed that orally administered GM may exert positive effects in a cGVHD mouse model

Asperuloside Improves Obesity and Type 2 Diabetes through Modulation of Gut Microbiota and Metabolic Signaling

Asperuloside (ASP) is an iridoid glycoside that is extracted from Eucommia leaves. Eucommia is used in traditional Chinese medicine and has a long history of benefits on health and longevity. Here, we investigated the impact of ASP on obesity-related metabolic disorders and show that ASP reduces body weight gain, glucose intolerance, and insulin resistance effectively in mice fed with a high-fat diet (HFD). Intestinal dysbiosis is closely linked with metabolic disorders. Our data indicate that ASP achieves these benefits on metabolic homeostasis by reversing HFD-induced gut dysbiosis and by changing gut-derived secondary metabolites and metabolic signaling. Our results indicate that ASP may be used to regulate gut microbiota for the treatment of obesity and type 2 diabetes