Learning from Peers in Community Japanese Language Classrooms ： Teacher Involvement Patterns in Peer Learning

本論文では、地域ボランティア日本語教室における学習者間学習への教師の関与について会話分析の手法を用いて分析した。　現在までに教室の中で行われる会話について会話分析やその隣接分野における多数の論文が発表されている。また、日本語教育の場で行われるピア・ラーニングについても教師の役割やピア・ラーニングの可能性、意義などについて多くの研究が行われている。しかしながら、現在のところ、従来型の教師中心の教室で時折みられる学習者間学習をミクロのレベルで分析した研究は、少なくとも会話分析やその隣接分野の研究ではみられない。そこで本論文では、従来型の教師中心の教室で時折みられる学習者間学習への教師の関与について会話分析の手法を用いて詳細に検証した

Complete remission of diabetes with a transient HDAC inhibitor and insulin in streptozotocin mice

Despite the growing epidemic worldwide, diabetes is an incurable disease. We have been focusing on why diabetes manifests refractoriness to any therapy. We recently found that abnormal bone marrow-derived cells (BMDCs), namely, Vcam-1+ST-HSCs, was a key mechanism for diabetic complications. We then hypothesize that those aberrant BMDCs sustainedly impair pancreatic β cells. Here we show that eliminating abnormal BMDCs using bone marrow transplantation results in controlling serum glucose in diabetic mice, in which normoglycemia is sustained even after cessation of insulin therapy. Alternatively, abnormal BMDCs exhibiting epigenetic alterations are treated with an HDAC inhibitor, givinostat, in diabetic mice. As a result, those mice are normoglycemic along with restored insulin secretion even following the cessation of both insulin and givinostat. Diabetic cell fusion between abnormal BMDCs and resident cells is significantly blocked by the combination therapy in the pancreatic islets and thymus while surgical ablation of the thymus completely eliminates therapeutic protection in diabetic mice. In conclusion, diabetes is an epigenetic stem cell disorder with thymic disturbances. The combination may be applied to patients aiming at complete remission from diabetes in clinical medicine.journal articl

GLT1 gene delivery based on bone marrow-derived cells ameliorates motor function and survival in a mouse model of ALS.

Amyotrophic lateral sclerosis (ALS) is an intractable neurodegenerative disease. CD68-positive bone marrow (BM)-derived cells (BMDCs) accumulate in the pathological lesion in the SOD1(G93A) ALS mouse model after BM transplantation (BMT). Therefore, we investigated whether BMDCs can be applied as gene carriers for cell-based gene therapy by employing the accumulation of BMDCs. In ALS mice, YFP reporter signals were observed in 12-14% of white blood cells (WBCs) and in the spinal cord via transplantation of BM after lentiviral vector (LV) infection. After confirmation of gene transduction by LV with the CD68 promoter in 4-7% of WBCs and in the spinal cord of ALS mice, BM cells were infected with LVs expressing glutamate transporter (GLT) 1 that protects neurons from glutamate toxicity, driven by the CD68 promoter, which were transplanted into ALS mice. The treated mice showed improvement of motor behaviors and prolonged survival. Additionally, interleukin (IL)-1β was significantly suppressed, and IL-4, arginase 1, and FIZZ were significantly increased in the mice. These results suggested that GLT1 expression by BMDCs improved the spinal cord environment. Therefore, our gene therapy strategy may be applied to treat neurodegenerative diseases such as ALS in which BMDCs accumulate in the pathological lesion by BMT

Hyperglycemia Induces Skin Barrier Dysfunctions with Impairment of Epidermal Integrity in Non-Wounded Skin of Type 1 Diabetic Mice.

Diabetes causes skin complications, including xerosis and foot ulcers. Ulcers complicated by infections exacerbate skin conditions, and in severe cases, limb/toe amputations are required to prevent the development of sepsis. Here, we hypothesize that hyperglycemia induces skin barrier dysfunction with alterations of epidermal integrity. The effects of hyperglycemia on the epidermis were examined in streptozotocin-induced diabetic mice with/without insulin therapy. The results showed that dye leakages were prominent, and transepidermal water loss after tape stripping was exacerbated in diabetic mice. These data indicate that hyperglycemia impaired skin barrier functions. Additionally, the distribution of the protein associated with the tight junction structure, tight junction protein-1 (ZO-1), was characterized by diffuse and significantly wider expression in the diabetic mice compared to that in the control mice. In turn, epidermal cell number was significantly reduced and basal cells were irregularly aligned with ultrastructural alterations in diabetic mice. In contrast, the number of corneocytes, namely, denucleated and terminally differentiated keratinocytes significantly increased, while their sensitivity to mechanical stress was enhanced in the diabetic mice. We found that cell proliferation was significantly decreased, while apoptotic cells were comparable in the skin of diabetic mice, compared to those in the control mice. In the epidermis, Keratin 5 and keratin 14 expressions were reduced, while keratin 10 and loricrin were ectopically induced in diabetic mice. These data suggest that hyperglycemia altered keratinocyte proliferation/differentiation. Finally, these phenotypes observed in diabetic mice were mitigated by insulin treatment. Reduction in basal cell number and perturbation of the proliferation/differentiation process could be the underlying mechanisms for impaired skin barrier functions in diabetic mice

A novel role for bone marrow-derived cells to recover damaged keratinocytes from radiation-induced injury.

Exposure to moderate doses of ionizing radiation (IR), which is sufficient for causing skin injury, can occur during radiation therapy as well as in radiation accidents. Radiation-induced skin injury occasionally recovers, although its underlying mechanism remains unclear. Moderate-dose IR is frequently utilized for bone marrow transplantation in mice; therefore, this mouse model can help understand the mechanism. We had previously reported that bone marrow-derived cells (BMDCs) migrate to the epidermis-dermis junction in response to IR, although their role remains unknown. Here, we investigated the role of BMDCs in radiation-induced skin injury in BMT mice and observed that BMDCs contributed to skin recovery after IR-induced barrier dysfunction. One of the important mechanisms involved the action of CCL17 secreted by BMDCs on irradiated basal cells, leading to accelerated proliferation and recovery of apoptosis caused by IR. Our findings suggest that BMDCs are key players in IR-induced skin injury recovery

Bone marrow-derived vasculogenesis leads to scarless regeneration in deep wounds with periosteal defects

Deep skin wounds with periosteal defects, frequently caused by traffic accidents or radical dissection, are refractory. Transplant surgery is frequently performed, but patients are subjected to stress for long operation periods, the sacrifice of donor regions, or several complications, such as flap necrosis or intractable ulcers. Even if the defects are covered, a scar composed of fibrous tissue remains in the body, which can cause itching, dysesthesia, or repeated ulcers because of the lack of distribution of peripheral nerves or hair follicles. Thus, treatments with the aim of regenerating lost tissue for deep wounds with periosteal defects are needed. Here, we show that the use of gelatin sponges (GS), which have been used as haemostatic materials in clinical practice, allowed the regeneration of heterogeneous tissues, including periosteum, skin, and skin appendages, when used as scaffolds in deep wounds with periosteal defects in rats. Bone marrow transplantation in rats revealed the mechanism by which the microenvironment provided by GS enabled bone marrow-derived cells (BMDCs) to form a vascular niche, followed by regeneration of the periosteum, skin, or skin appendages such as hair follicles by local cells. Our findings demonstrated that vascular niche formation provided by BMDCs is crucial for heterogeneous tissue regeneration

Protective role of podocyte autophagy against glomerular endothelial dysfunction in diabetes.

To examine the cell-protective role of podocyte autophagy against glomerular endothelial dysfunction in diabetes, we analyzed the renal phenotype of tamoxifen (TM)-inducible podocyte-specific Atg5-deficient (iPodo-Atg5-/-) mice with experimental endothelial dysfunction. In both control and iPodo-Atg5-/- mice, high fat diet (HFD) feeding induced glomerular endothelial damage characterized by decreased urinary nitric oxide (NO) excretion, collapsed endothelial fenestrae, and reduced endothelial glycocalyx. HFD-fed control mice showed slight albuminuria and nearly normal podocyte morphology. In contrast, HFD-fed iPodo-Atg5-/- mice developed massive albuminuria accompanied by severe podocyte injury that was observed predominantly in podocytes adjacent to damaged endothelial cells by scanning electron microscopy. Although podocyte-specific autophagy deficiency did not affect endothelial NO synthase deficiency-associated albuminuria, it markedly exacerbated albuminuria and severe podocyte morphological damage when the damage was induced by intravenous neuraminidase injection to remove glycocalyx from the endothelial surface. Furthermore, endoplasmic reticulum stress was accelerated in podocytes of iPodo-Atg5-/- mice stimulated with neuraminidase, and treatment with molecular chaperone tauroursodeoxycholic acid improved neuraminidase-induced severe albuminuria and podocyte injury. In conclusion, podocyte autophagy plays a renoprotective role against diabetes-related structural endothelial damage, providing an additional insight into the pathogenesis of massive proteinuria in diabetic nephropathy

Malfunctioning CD106-positive, short-term hematopoietic stem cells trigger diabetic neuropathy in mice by cell fusion.

Diabetic neuropathy is an incurable disease. We previously identified a mechanism by which aberrant bone marrow-derived cells (BMDCs) pathologically expressing proinsulin/TNF-α fuse with residential neurons to impair neuronal function. Here, we show that CD106-positive cells represent a significant fraction of short-term hematopoietic stem cells (ST-HSCs) that contribute to the development of diabetic neuropathy in mice. The important role for these cells is supported by the fact that transplantation of either whole HSCs or CD106-positive ST-HSCs from diabetic mice to non-diabetic mice produces diabetic neuronal dysfunction in the recipient mice via cell fusion. Furthermore, we show that transient episodic hyperglycemia produced by glucose injections leads to abnormal fusion of pathological ST-HSCs with residential neurons, reproducing neuropathy in nondiabetic mice. In conclusion, we have identified hyperglycemia-induced aberrant CD106-positive ST-HSCs underlie the development of diabetic neuropathy. Aberrant CD106-positive ST-HSCs constitute a novel therapeutic target for the treatment of diabetic neuropathy