Biology subjects

Notoh, H.

Publications and source records attributed to Notoh, H..

3 recordsLinked to original sources

bioRxiv2024

PDPN/CLEC-2 axis modulates megakaryocyte subtypes in a hematopoietic stem cell-regulating megakaryocyte-dominant manner

IntroductionMegakaryocytes are classified into several subtypes including LSP1-positive immune-skewed, MYLK4-positive hematopoietic stem cell (HSC)-regulating, and BMAL1-positive platelet-producing megakaryocytes. Podoplanin (PDPN)-expressing stromal cells generate a microenvironment that promotes megakaryopoiesis in the bone marrow. In this context, PDPN interacts with C-type lectin-like receptor-2 (CLEC-2) on megakaryocyte progenitors, which induces megakaryocyte proliferation. However, the megakaryocyte subtypes developed by the regulation of the PDPN/CLEC-2 axis have not yet been elucidated. Materials and MethodsWe established an immortalized bone marrow PDPN-expressing stromal cell line and a PDPN-knockout line (PDPN WT and KO feeder cells, respectively). Bone marrow hematopoietic progenitors were committed to megakaryocytes in co-culture with PDPN WT or KO feeder cells. The number and ploidy of megakaryocytes, resultant platelets, and the polarization of megakaryocyte subtypes were investigated. ResultsThe number of megakaryocytes was significantly increased in the co-culture with PDPN WT feeder cells compared to that with PDPN KO feeder cells. The megakaryocytes on the PDPN WT and KO feeders showed their main ploidy at 16N[~]32N and 8N[~]16N, respectively. The number of platelets decreased in the co-culture with the PDPN WT feeder compared to those in the co-culture with the PDPN KO feeder. Megakaryocyte subtypes were immunocytochemically detected in in vitro differentiated CD41-positive megakaryocytes. For each megakaryocyte subtype, the percentage of MYLK4-positive megakaryocytes significantly increased and the percentage of BMAL1-positive megakaryocytes significantly decreased when co-cultured with the PDPN WT feeder. ConclusionThe PDPN/CLEC-2 axis modulates megakaryocyte subtype differentiation, with a predominance of HSC-regulating megakaryocytes.

cell biology↗

bioRxiv2024

Tissue growth associated transition of podoplanin-expressing stromal cells in the postnatal mouse femur

In vertebral long bones, such as the femur, bone formation involves endochondral ossification. Endochondral ossification first occurs in the central region of the fetal diaphysis, the primary ossification center. Podoplanin (PDPN) is a transmembrane mucin-like glycoprotein, and PDPN-positive cells play key roles in various organ/tissue development. In adult mice, osteolineage PDPN-positive cells are associated with femoral microarchitecture. However, specific roles of PDPN in fetal bone development remain unclear. Therefore, in this study, we aimed to investigate the spatiotemporal dynamics and physiological functions of PDPN-positive cells during fetal femur development. In the fetal femur, PDPN-positive cells first emerged in the primitive cortical bone, termed the bone collar, concurrently with primary ossification center initiation. Several PDPN-positive cells in the bone collar migrated to the marrow cavity and populated the metaphyseal trabecular bone. Most PDPN-positive cells in both the bone collar and trabeculae exhibited osteolineage features, such as osterix expression. Pdpn knockout fetuses exhibited abnormal recruitment of osterix-positive cells and mineral deposition in the dorsal bone collar. Overall, our results suggest that PDPN-positive cells constitute a spatially regulated osteolineage population that contributes to coordinated fetal femur development.

cell biology↗

bioRxiv2023

Basement membrane extract potentiates the endochondral ossification phenotype of bone marrow-derived mesenchymal stem cell-based cartilage organoids

Endochondral ossification is a developmental process in the skeletal system and bone marrow of vertebrates. During endochondral ossification, primitive cartilaginous anlages derived from mesenchymal stem cells (MSCs) undergo vascular invasion and ossification. In vitro regeneration of endochondral ossification is beneficial for research on the skeletal system and bone marrow development as well as their clinical aspects. However, to achieve the regeneration of endochondral ossification, a stem cell-based artificial cartilage (cartilage organoid, Cart-Org) that possesses an endochondral ossification phenotype is required. Here, we modified a conventional 3D culture method to create stem cell-based Cart-Org by mixing it with a basement membrane extract (BME) and further characterized its chondrogenic and ossification properties. BME enlarged and matured the bone marrow MSC-based Cart-Orgs without any shape abnormalities. Histological analysis using Alcian blue staining showed that the production of cartilaginous extracellular matrices was enhanced in Cart-Org treated with BME. Transcriptome analysis using RNA sequencing revealed that BME altered the gene expression pattern of Cart-Org to a dominant chondrogenic state. BME triggered the activation of the SMAD pathway and inhibition of the NK-{kappa}B pathway, which resulted in the upregulation of SOX9, COL2A1, and ACAN in Cart-Org. BME also facilitated the upregulation of genes associated with hypertrophic chondrocytes (IHH, PTH1R, and COL10A1) and ossification (SP7, ALPL, and MMP13). Our findings indicate that BME promotes cartilaginous maturation and further ossification of bone marrow MSC-based Cart-Org, suggesting that Cart-Org treated with BME possesses the phenotype of endochondral ossification. HighlightsO_LIBasement membrane extract (BME) enlarges MSC-based Cart-Org. C_LIO_LIBME activates the SMAD pathway and inhibits the NK-kB pathway of the Cart-Org. C_LIO_LIBME promotes cartilaginous maturation and further ossification of Cart-Org. C_LI

cell biology↗