記述言語：英語   掲載種別：研究論文（学術雑誌）  

Development of the mammalian telencephalon, which is the most complex region of the central nervous system, is precisely orchestrated by many signaling molecules. Wnt signaling derived from the cortical hem, a signaling center, is crucial for telencephalic development including cortical patterning and the induction of hippocampal development. Secreted protein R-spondin (Rspo) 1-4 and their receptors, leucine-rich repeat-containing G-protein-coupled receptor (Lgr) 4-6, act as activators of Wnt signaling. Although Rspo expression in the hem during the early stages of cortical development has been reported, comparative expression analysis of Rspos and Lgr4-6 has not been performed. In this study, we examined the detailed spatiotemporal expression patterns of Rspo1-4 and Lgr4-6 in the embryonic and postnatal telencephalon to elucidate their functions. In the embryonic day (E) 10.5-14.5 telencephalon, Rspo1-3 were prominently expressed in the cortical hem. Among their receptors, Lgr4 was observed in the ventral telencephalon, and Lgr6 was highly expressed throughout the telencephalon at the same stages. This suggests that Rspo1-3 and Lgr4 initially regulate telencephalic development in restricted regions, whereas Lgr6 functions broadly. From the late embryonic stage, the expression areas of Rspo1-3 and Lgr4-6 dramatically expanded; their expression was found in the neocortex and limbic system, such as the hippocampus, amygdala, and striatum. Increased Rspo and Lgr expression from the late embryonic stages suggests broad roles of Rspo signaling in telencephalic development. Furthermore, the Lgr+ regions were located far from the Rspo+ regions, especially in the E10.5-14.5 ventral telencephalon, suggesting that Lgrs act via a Rspo-independent pathway.

DOI： 10.1016/j.gep.2023.119333

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Aberrant osteoclast formation and activation are the hallmarks of osteolytic metastasis. Extracellular vesicles (EVs), released from bone metastatic tumor cells, play a pivotal role in the progression of osteolytic lesions. However, the mechanisms through which tumor cell-derived EVs regulate osteoclast differentiation and function have not been fully elucidated. In this study, we found that 4T1 bone metastatic mouse mammary tumor cell-derived EVs (4T1-EVs) are taken up by mouse bone marrow macrophages to facilitate osteoclastogenesis. Furthermore, treatment of mature osteoclasts with 4T1-EVs promoted bone resorption, which was accompanied by enhanced survival of mature osteoclasts through the negative regulation of caspase-3. By comparing the miRNA content in 4T1-EVs with that in 67NR nonmetastatic mouse mammary tumor cell-derived EVs (67NR-EVs), miR-92a-3p was identified as one of the most enriched miRNAs in 4T1-EVs, and its transfer into mature osteoclasts significantly reduced apoptosis. Bioinformatic and Western blot analyses revealed that miR-92a-3p directly targeted phosphatase and tensin homolog (PTEN) in mature osteoclasts, resulting in increased levels of phospho-Akt. Our findings provide novel insights into the EV-mediated regulation of osteoclast survival through the transfer of miR-92a-3p, which enhances mature osteoclast survival via the Akt survival signaling pathway, thus promoting bone resorption.

DOI： 10.1111/cas.15557

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The epithelial basal lamina of the small intestine has numerous fenestrations for intraepithelial migration of leukocytes. We have reported dynamic changes of fenestrations in dietary conditions. To investigate this phenomenon, we performed statistical analyses using scanning electron microscopy images of the epithelial basal lamina of rat intestinal villi after removal of the villous epithelium by osmium maceration. We examined structural changes in the number and size of fenestrations in the rat jejunum and ileum under fasted and fed states for 24 h. Our findings revealed that, in the jejunum, the number of free cells migrating into the epithelium through fenestrations increased from 2 h after feeding, resulting in an increase in the fenestration size of intestinal villi; the number of free cells then tended to decrease at 6 h after feeding, and the fenestration size also gradually decreased. By contrast, the increase in the fenestration size by feeding was not statistically significant in the ileum. These findings indicate that the number of migrating cells increases in the upper part of the small intestine under dietary conditions, which may influence the absorption efficiency of nutrients including lipids, as well as the induction of nutrient-induced inflammation.

DOI： 10.2220/biomedres.43.11

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.archoralbio.2020.104956

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

To elucidate the underlying mechanism of secretory leukocyte protease inhibitor (SLPI)-induced cell migration, we compared SLPI-deleted human gingival carcinoma Ca9-22 (ΔSLPI) cells and original (wild-type: wt) Ca9-22 cells using several microscopic imaging methods and gene expression analysis. Our results indicated reduced migration of ΔSLPI cells compared to wtCa9-22 cells. The lamellipodia/dorsal ruffles were smaller and moved slower in ΔSLPI cells compared to wtCa9-22 cells. Furthermore, well-developed intermediate filament bundles were observed at the desmosome junction of ΔSLPI cells. In addition, Galectin4 was strongly expressed in ΔSLPI cells, and its forced expression suppressed migration of wtCa9-22 cells. Taken together, SLPI facilitates cell migration by regulating lamellipodia/ruffles and desmosomes, in which Galectin4 plays an important role.

DOI： 10.1080/19336918.2020.1829264

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

In bone tissues, gap junctions form direct links between the cytoplasm of an osteocyte and another adjacent osteocyte or osteoblast, which underlie both bone formation and bone resorption. We have previously demonstrated that alkaline phosphatase (ALP) and bone sialoprotein (BSP), which are osteoblast markers, were induced in mesenchymal stem cells (MSCs) co-cultured with osteoblast-like cell line. However, the molecular mechanism of this process has not been fully addressed. Furthermore, few advances have been made toward elucidating the communication networks that link the status of committed cells such as (pre-) adipocytes that differentiated from MSCs as well as osteoblasts. Therefore, the objective of the present study was to investigate the mechanism underlying the communication network between pre-adipocytes and osteoblasts. We evaluated the effect of co-culture with osteoblast on the cell status of pre-adipocytes using murine osteoblast-like cell line, MLO-A5, and pre-adipocyte-like cell line, 3T3-L1, respectively. The results presented here demonstrated that osteoblasts and pre-adipocytes communicate via gap junctions, and the ensuing drastic increase in ALP and BSP transcription in co-cultured pre-adipocytes was induced, at least partly, via heat shock protein family B member 1 (Hspb1). In addition, terminal differentiation into adipocytes was suppressed in pre-adipocytes during co-culture with osteoblast without loss of adipogenic differentiation ability. Interestingly, after co-culture with osteoblasts, isolated co-cultured pre-adipocytes were able to differentiate to adipocytes as well as original pre-adipocytes. These results suggest that gap junctional communication with osteoblasts suppressed adipogenic differentiation of pre-adipocytes without loss of adipogenic differentiation ability.

DOI： 10.1016/j.bone.2020.115596

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Considering the increase in cases of non-alcoholic steatohepatitis (NASH), the use of appropriate animal model of NASH is essential to understand the underlying pathogenesis mechanism. To date, several mice models have been used; however, significant differences in the etiologies and food administered affected the results, with inconsistent conclusions. Therefore, it is necessary to understand these models and their differences to be able to choose appropriate models. Inspired by the fact that mitochondrial (mt)DNA content is changed in non-alcoholic fatty liver disease in humans, we investigated the mtDNA copy number in the NASH mice models induced by high-fat diet (HFD) and methionine/choline-deficient diet (MCD) to understand the differences between these models. Megamitochondria were observed in both MCD and HFD groups. However, the MCD group showed significant decrease in liver mtDNA content compared with that in the HFD group. These changes were associated with significant upregulation of mitochondrial biogenesis- and degradation-related genes in MCD model than in HFD model. Thus, stability of mtDNA is associated with the differences between MCD and HFD-induced NASH models often used in studies; these findings could help in choosing appropriate models for studies on NASH.

DOI： 10.1016/j.bbrc.2020.03.180

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記述言語：日本語   出版者・発行元：(NPO)日本歯周病学会  

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記述言語：日本語   出版者・発行元：(NPO)日本歯周病学会  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The basal lamina of the villous epithelium in the small intestine has numerous fenestrations, which are produced by leukocytes for their intraepithelial migration. We previously showed that these fenestrations change due to the dynamics of migrating leukocytes in response to dietary conditions and suggested the possibility that this change is related to the regulation of the absorption of large-sized nutrients such as chylomicrons. The present study was, thus, designed to investigate structural changes in basal lamina fenestrations in response to a high-fat diet. The ultrastructure of the intestinal villi in the rat upper jejunum was investigated by electron microscopy of tissue sections in both the normal and the high-fat diet groups, and the fenestrations in the villous epithelium of rat upper jejunum were studied by scanning electron microscopy of osmium macerated/ ultrasonicated tissues. The present study showed that free cells adhering to the fenestrations increased in the upper jejunum two hours after feeding high-fat diet and the size of the fenestrations in this region also increased after feeding high-fat diet for 2 days. This enlargement of fenestrations may play an important role in increasing the efficiency of lipid absorption by facilitating the movement of chylomicrons from the intercellular space to the lamina propria.

DOI： 10.2220/biomedres.40.57

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jphs.2018.10.002

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature Publishing Group  

DOI： 10.1038/s41598-018-27408-y

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Biomedical Research Foundation  

DOI： 10.2220/biomedres.39.65

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Public Library of Science  

DOI： 10.1371/journal.pone.0189726

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2220/biomedres.38.239

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/jmicro/dfv031

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jplph.2014.06.008

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s10265-012-0494-6

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/jmicro/dfr095

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