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

Reduction Rate and Crushing Strength of a Carbon-Containing Pellet Prepared by the Impregnation Method of COG Tar

The crushing strength and reduction rate of a carbon-containing pellet (composite) prepared from a cold-bonded pellet (CP) and coke oven gas (COG) tar are examined. The peak of the pore size distribution profile, at approximately 2 nm, observed in the as-prepared CP decreases with the increase in the mixture ratio of tar to CP and completely disappears for the composites prepared above a mixture ratio of 1.0, and the <i>S</i>_BET and <i>V</i>_BJH values are <1 m²/g and <0.01 cm³/g, respectively. The crushing strength of the composites increases with the increase in the mixture ratio of tar to CP and becomes 10 daN from 1.0 daN, above a mixture ratio of 2.0. Carbonaceous material derived from tar is detected on the surface of the composite particle, as well as inside the particle, and the C content in the composite is 22 mass%-C. When the composites are heated in He and 55%H₂/He, the evolution of CO, CO₂, and H₂O starts at approximately 400 and 500 °C, respectively, and the formation profiles indicate a large peak at approximately 800–900 °C. The extent of reduction of the composites at 1000 °C is 85–95%. The crushing strength of the dehydrated-CP decreases drastically up to a reduction extent of 50%, whereas the strength of the composites is maintained at a reduction rate up to 50% and then decreases with the increase in the reduction rate

Preparation of Carbon-Containing Iron Ore with Enhanced Crushing Strength from Limonite by Impregnation and Vapor Deposition of Tar Recovered from Coke Oven Gas

The optimum conditions for preparing carbon-containing iron ore (composites), in which coke-oven-gas-tar-derived carbonaceous materials completely filled the pores in Indonesian limonite (IL), are investigated using impregnation (IM) and vapor deposition (VD). A peak around 2 nm is observed in the pore size distribution profiles for the as-received IL and IL absolutely heated to a predetermined temperature. The intensity of the peak decreased with increasing ratio of tar to IL (tar/IL) for the IM-prepared composites, and it completely disappeared for the composites prepared with tar/IL > 1.0; the corresponding <i>S</i>_BET and <i>V</i>_BJH are <1 m²/g and <0.01 cm³/g, respectively. The peak at 2 nm in the pore size distribution profiles for the VD-prepared composites almost disappears for treatment times longer than 60 min for any combination of conditions for tar pyrolysis temperature (TPT) and VD temperature (VDT). The composite prepared using a combination of TPT–VDT of 700–350 °C for 60 min shows the highest carbon content and crushing strength. The C content and crushing strength of the IM- and VD-prepared composites increase with increasing tar/IL and VD time. The composite prepared with tar/IL = 3.0 and VD time of 240 min shows a C content and crushing strength of 48–50 wt %-dry and 10 daN, respectively. The cross-sectional analyses of composite particles prepared using both methods show that the tar-derived carbonaceous materials has completely filled the pores

Myelin protein zero (P0)- and Wnt1-Cre marked muscle resident neural crest-derived mesenchymal progenitor cells give rise to heterotopic ossification in mouse models

進行性骨化性線維異形成症の異所性骨は神経堤細胞から作られる. 京都大学プレスリリース. 2023-06-07.Unveiling the Origins of Ectopic Bones: Insights from Neural Crest Cell Research. 京都大学プレスリリース. 2023-06-12

Interferon-γ Produced by EBV-Positive Neoplastic NK-Cells Induces Differentiation into Macrophages and Procoagulant Activity of Monocytes, Which Leads to HLH

Epstein–Barr virus (EBV)-positive T- or NK-cell neoplasms show progressive systemic inflammation and abnormal blood coagulation causing hemophagocytic lymphohistiocytosis (HLH). It was reported that inflammatory cytokines were produced and secreted by EBV-positive neoplastic T- or NK-cells. These cytokines can induce the differentiation of monocytes into macrophages leading to HLH. To clarify which products of EBV-positive neoplastic T- or NK-cells have effects on monocytes, we performed a co-culture assay of monocytes with the supernatants of EBV-positive T- or NK-cell lines. The expression of differentiation markers, the phagocytosis ability, and the mRNA expression of the inflammatory cytokines of THP-1, a monocytic cell line, clearly increased after culturing with the supernatants from EBV-NK-cell lines. Co-culturing with the supernatants promoted the expression of CD80 and CD206 as well as M1 and M2 macrophage markers in human monocytes. Co-culturing with the supernatants of EBV-NK-cell lines significantly enhanced the procoagulant activity and the tissue factor expression of monocytes. Interferon (IFN)-γ was elevated extremely not only in the supernatant of EBV-NK-cell lines but also in the plasma of EBV-positive NK-cell neoplasms patients accompanying HLH. Finally, we confirmed that IFN-γ directly enhanced the differentiation into M1-like macrophages and the procoagulant activity of monocytes. Our findings suggest that IFN-γ may potentially serve as a therapeutic target to regulate HLH in EBV-positive NK-cell neoplasms

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

Impact of the COVID-19 epidemic at a high-volume facility in gynecological oncology in Tokyo, Japan: a single-center experience

Abstract Background The number of cases of novel coronavirus disease 2019 (COVID-19) in Japan have risen since the first case was reported on January 24, 2020, and 6225 infections have been reported as of June 30, 2020. On April 8, 2020, our hospital began screening patients via pre-admission reverse transcriptase-polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and chest computed tomography (CT). Although no patients exhibited apparent pneumonia, treatment delay or changes in treatment plans were required for a few patients based on the results of screening tests. During an emerging infectious disease pandemic, the likelihood of being infected, as well as the disease itself, affects clinical decision making in several ways. We summarized and presented our experience. Case presentation After the introduction of pre-admission screening, RT-PCR and CT were performed in 200 and 76 patients, respectively, as of June 30, 2020. The treatment of five patients, including two patients with cervical cancer, two patients with ovarian tumors, and one patient with ovarian cancer, was affected by the results. Two asymptomatic RT-PCR-positive patients did not develop COVID-19, but their treatment was delayed until the confirmation of negative results. The other three patients were RT-PCR-negative, but abnormal CT findings suggested the possibility of COVID-19, which delayed treatment. The patients receiving first-line preoperative chemotherapy for ovarian cancer had clinically evident exacerbations because of the treatment delay. Conclusion During the epidemic phase of an emerging infectious disease, we found that COVID-19 has several other effects besides its incidence. The postponing treatment was the most common, therefore, treatment of ovarian tumors and ovarian cancer was considered to be the most likely to be affected among gynecological diseases. Protocols that allow for easy over-diagnosis can be disadvantageous, mainly because of treatment delays, and therefore, the protocols must be developed in light of the local infection situation