Bir kırmızı, bir sarı gül ve Gülbaba

Taha Toros Arşivi, Dosya Adı: Galatasarayİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Differentiation of hypertrophic chondrocytes from human iPSCs for the in vitro modeling of chondrodysplasias

iPS細胞から肥大軟骨細胞への誘導法を確立し、成長板疾患の病態再現に成功. 京都大学プレスリリース. 2021-02-26.Reprogramming children's cells to study cartilage diseases. 京都大学プレスリリース. 2021-02-26.Chondrodysplasias are hereditary diseases caused by mutations in the components of growth cartilage. Although the unfolded protein response (UPR) has been identified as a key disease mechanism in mouse models, no suitable in vitro system has been reported to analyze the pathology in humans. Here, we developed a three-dimensional culture protocol to differentiate hypertrophic chondrocytes from induced pluripotent stem cells (iPSCs) and examine the phenotype caused by MATN3 and COL10A1 mutations. Intracellular MATN3 or COL10 retention resulted in increased ER stress markers and ER size in most mutants, but activation of the UPR was dependent on the mutation. Transcriptome analysis confirmed a UPR with wide-ranging changes in bone homeostasis, extracellular matrix composition, and lipid metabolism in the MATN3 T120M mutant, which further showed altered cellular morphology in iPSC-derived growth-plate-like structures in vivo. We then applied our in vitro model to drug testing, whereby trimethylamine N-oxide led to a reduction of ER stress and intracellular MATN3

A Japanese predicate argument structure analysis using decision lists

Maintaining high annotation consistency in large corpora is crucial for statistical learning; however, such work is hard, especially for tasks containing semantic elements. This paper describes predi-cate argument structure analysis using transformation-based learning. An advan-tage of transformation-based learning is the readability of learned rules. A dis-advantage is that the rule extraction pro-cedure is time-consuming. We present incremental-based, transformation-based learning for semantic processing tasks. As an example, we deal with Japanese pred-icate argument analysis and show some tendencies of annotators for constructing a corpus with our method.

Density-dependent induction of TNF-α release from human monocytes by immobilized P-selectin

AbstractP-selectin purified from human platelets, when immobilized on a solid surface, induced monocytes to release tumor necrosis factor-α (TNF-α). The induction of TNF-α release was dependent on the concentration of P-selectin used for the immobilization, and the maximal stimulation was observed when the plate was coated with 0.3 μg/ml of P-selectin. Use of either a higher or a lower concentration of P-selectin for the plate-coating was found to elicit less TNF-α release, although the higher concentration of P-selectin caused a stronger adhesion of HL-60 leukemic cells. The expression of mRNA for TNF-α roughly paralleled the TNF-α secretion, as assessed by RT-PCR. These results indicate that monocytes are activated by immobilized P-selectin in a density-dependent manner

An mTOR Signaling Modulator Suppressed Heterotopic Ossification of Fibrodysplasia Ossificans Progressiva

FOPにおける骨化を抑える新たな候補物質の同定 --治療法探索へ新しい戦略への可能性を拓く--. 京都大学プレスリリース. 2018-11-02.Fibrodysplasia ossificans progressiva (FOP) is a rare and intractable disorder characterized by extraskeletal bone formation through endochondral ossification. FOP patients harbor gain-of-function mutations in ACVR1 (FOP-ACVR1), a type I receptor for bone morphogenetic proteins. Despite numerous studies, no drugs have been approved for FOP. Here, we developed a high-throughput screening (HTS) system focused on the constitutive activation of FOP-ACVR1 by utilizing a chondrogenic ATDC5 cell line that stably expresses FOP-ACVR1. After HTS of 5, 000 small-molecule compounds, we identified two hit compounds that are effective at suppressing the enhanced chondrogenesis of FOP patient-derived induced pluripotent stem cells (FOP-iPSCs) and suppressed the heterotopic ossification (HO) of multiple model mice, including FOP-ACVR1 transgenic mice and HO model mice utilizing FOP-iPSCs. Furthermore, we revealed that one of the hit compounds is an mTOR signaling modulator that indirectly inhibits mTOR signaling. Our results demonstrate that these hit compounds could contribute to future drug repositioning and the mechanistic analysis of mTOR signaling

3D osteogenic differentiation of human iPSCs reveals the role of TGFβ signal in the transition from progenitors to osteoblasts and osteoblasts to osteocytes

Abstract Although the formation of bone-like nodules is regarded as the differentiation process from stem cells to osteogenic cells, including osteoblasts and osteocytes, the precise biological events during nodule formation are unknown. Here we performed the osteogenic induction of human induced pluripotent stem cells using a three-dimensional (3D) culture system using type I collagen gel and a rapid induction method with retinoic acid. Confocal and time-lapse imaging revealed the osteogenic differentiation was initiated with vigorous focal proliferation followed by aggregation, from which cells invaded the gel. Invading cells changed their morphology and expressed osteocyte marker genes, suggesting the transition from osteoblasts to osteocytes. Single-cell RNA sequencing analysis revealed that 3D culture-induced cells with features of periosteal skeletal stem cells, some of which expressed TGFβ-regulated osteoblast-related molecules. The role of TGFβ signal was further analyzed in the transition from osteoblasts to osteocytes, which revealed that modulation of the TGFβ signal changed the morphology and motility of cells isolated from the 3D culture, suggesting that the TGFβ signal maintains the osteoblastic phenotype and the transition into osteocytes requires down-regulation of the TGFβ signal