High-pressure and high-temperature synthesis of heavy lanthanide sesquisulfides Ln2S3 ( Ln=Yb and Lu)

Detailed pressure-temperature phase diagrams of heavy lanthanide sesquisulfides Ln2S3 (Ln = Yb and Lu) have been investigated by in-situ x-ray diffraction experiments under high pressure and high temperature using synchrotron radiation and multi-anvil press. Based on the results of the in-situ observation, the single γ-phase (Th3P4-type structure, I3d) samples of Ln2S3 (Ln = Yb and Lu) have been synthesized under high pressure. The physical properties of the compounds were studied by electrical resistivity, specific heat, and magnetic susceptibility measurements between 2 K and 300 K

Stump problems in traumatic amputation.

Stump problems in amputations resulting from employment related injuries were investigated in 397 cases in the Chugoku and Shikoku districts of Japan between 1987 and 1991. Ninety-seven patients (24%) had stump problems which interfered the prosthetic fitting. Stump problems of the upper extremity were seen in about 9% (17 amputees), two thirds of which were skin troubles. Stump problems of the lower extremity were seen in about 37% (80 amputees). Certain complaints were associated with specific methods of amputation; abnormal keratosis in Syme's amputation, equinus deformity in Chopart's amputation, reduced muscle power in above the knee (A/K) amputation and joint dysfunction in below the knee (B/K) amputation. Adequate prosthetic fitting was achieved by the modification of the socket and alignment in almost all amputees with stump problems. In only two cases, Chopart's amputation required subsequent Syme's amputation due to equinus deformity with abnormal keratosis. In almost every case, stump problems are avoidable by means of surgeons' deliberate evaluation of the affected limb and adequate choice of the amputation level.</p

Screening of factors inducing alveolar type 1 epithelial cells using human pluripotent stem cells.

ヒトiPS細胞由来肺胞スフェロイドの"on-gel培養法"による化合物スクリーニング --I型肺胞上皮細胞の分化を促進するシグナル経路を同定--. 京都大学プレスリリース. 2024-03-29.Constructing "on-gel" alveolar organoids as a new screening platform. 京都大学プレスリリース. 2024-03-29.Alveolar type 2 (AT2) epithelial cells are tissue stem cells capable of differentiating into alveolar type 1 (AT1) cells for injury repair and maintenance of lung homeostasis. However, the factors involved in human AT2-to-AT1 cell differentiation are not fully understood. Here, we established SFTPCGFP and AGERmCherry-HiBiT dual-reporter induced pluripotent stem cells (iPSCs), which detected AT2-to-AT1 cell differentiation with high sensitivity and identified factors inducing AT1 cell differentiation from AT2 and their progenitor cells. We also established an "on-gel" alveolar epithelial spheroid culture suitable for medium-throughput screening. Among the 274 chemical compounds, several single compounds, including LATS-IN-1, converted AT1 cells from AT2 and their progenitor cells. Moreover, YAP/TAZ signaling activation and AKT signaling suppression synergistically recapitulated the induction of transcriptomic, morphological, and functionally mature AT1 cells. Our findings provide novel insights into human lung development and lung regenerative medicine

Modeling of lung phenotype of Hermansky–Pudlak syndrome type I using patient-specific iPSCs

iPS細胞を用いてヘルマンスキー・パドラック症候群の肺病態の解析に成功 --研究が困難な遺伝性疾患の治療薬開発の足がかりに--. 京都大学プレスリリース. 2021-11-15.[Background] Somatic cells differentiated from patient-specific human induced pluripotent stem cells (iPSCs) could be a useful tool in human cell-based disease research. Hermansky–Pudlak syndrome (HPS) is an autosomal recessive genetic disorder characterized by oculocutaneous albinism and a platelet dysfunction. HPS patients often suffer from lethal HPS associated interstitial pneumonia (HPSIP). Lung transplantation has been the only treatment for HPSIP. Lysosome-related organelles are impaired in HPS, thereby disrupting alveolar type 2 (AT2) cells with lamellar bodies. HPSIP lungs are characterized by enlarged lamellar bodies. Despite species differences between human and mouse in HPSIP, most studies have been conducted in mice since culturing human AT2 cells is difficult. [Methods] We generated patient-specific iPSCs from patient-derived fibroblasts with the most common bi-allelic variant, c.1472_1487dup16, in HPS1 for modeling severe phenotypes of HPSIP. We then corrected the variant of patient-specific iPSCs using CRISPR-based microhomology-mediated end joining to obtain isogenic controls. The iPSCs were then differentiated into lung epithelial cells using two different lung organoid models, lung bud organoids (LBOs) and alveolar organoids (AOs), and explored the phenotypes contributing to the pathogenesis of HPSIP using transcriptomic and proteomic analyses. [Results] The LBOs derived from patient-specific iPSCs successfully recapitulated the abnormalities in morphology and size. Proteomic analysis of AOs involving iPSC-derived AT2 cells and primary lung fibroblasts revealed mitochondrial dysfunction in HPS1 patient-specific alveolar epithelial cells. Further, giant lamellar bodies were recapitulated in patient-specific AT2 cells. [Conclusions] The HPS1 patient-specific iPSCs and their gene-corrected counterparts generated in this study could be a new research tool for understanding the pathogenesis of HPSIP caused by HPS1 deficiency in humans

Directed induction of alveolar type I cells derived from pluripotent stem cells via Wnt signaling inhibition

iPS細胞を用いて肺胞上皮細胞の分化評価に成功 --肺の障害研究への足がかりに--. 京都大学プレスリリース. 2020-12-14.Alveologenesis is a developmental step involving the expansion of the lung surface area which is essential for gas exchange. The gas exchange process is mediated by alveolar type I (AT1) cells, which are known to be differentiated from alveolar type II (AT2) or bipotent cells. Due to the difficulty of isolating and culturing primary AT1 cells, the mechanism underlying their differentiation is not completely understood. We performed single‐cell RNA sequencing (scRNA‐seq) of fibroblast‐dependent alveolar organoids (FD‐AOs), including human induced pluripotent stem cell (hiPSC)‐derived epithelial cells and fetal lung fibroblasts, and identified hiPSC‐derived AT1 (iAT1) cells. A comparison of the FD‐AOs and fibroblast‐free alveolar organoids showed that iAT1 cells were mainly present in the FD‐AOs. Importantly, the transcriptomes of iAT1 cells were remarkably similar to those of primary AT1 cells. Additionally, XAV‐939, a tankyrase inhibitor, increased iAT1 cells in passaged FD‐AOs, suggesting that these cells were differentiated from hiPSC‐derived AT2 (iAT2) cells through the inhibition of canonical Wnt signaling. Consequently, our scRNA‐seq data allowed us to define iAT1 cells and identify FD‐AOs as a useful model for investigating the mechanism underlying human AT1 cell differentiation from AT2 cells in vitro

Core-shell hydrogel microfiber-expanded pluripotent stem cell-derived lung progenitors applicable to lung reconstruction in vivo

ヒトiPS細胞由来肺前駆細胞の拡大培養とマウス肺への移植・生着に成功 --肺再生医療の実現へ大きな一歩--. 京都大学プレスリリース. 2021-07-30.Lung transplantation is the only treatment available for end-stage lung diseases; however, donor shortage is a global issue. The use of human pluripotent stem cells (hPSCs) for organ regeneration is a promising approach. Nevertheless, methods for the expansion of isolated hPSC-derived lung progenitors (hLPs) for transplantation purposes have not yet been reported. Herein, we established an expansion system of hLPs based on their three-dimensional culture in core-shell hydrogel microfibers, that ensures the maintenance of their bipotency for differentiation into alveolar and airway epithelial cells including alveolar type II (AT2) cells. Further, we developed an efficient in vivo transplantation method using an endoscope-assisted transtracheal administration system; the successful engraftment and in vivo differentiation of hLPs into alveolar epithelial cells (incorporated into the alveoli) was observed. Importantly, expanded hLPs in the context of microfibers were successfully transplanted into the murine lungs, opening avenues for cell-based therapies of lung diseases. Therefore, our novel method has potential regenerative medicine applications; additionally, the high-quality hLPs and AT2 cells generated via the microfiber-based technology are valuable for drug discovery purposes

iPSC-derived mesenchymal cells that support alveolar organoid development

肺胞オルガノイドをつくることができるヒトiPS細胞由来間葉細胞の作成. 京都大学プレスリリース. 2022-10-12.Mesenchymal cells are necessary for organ development. In the lung, distal tip fibroblasts contribute to alveolar and airway epithelial cell differentiation and homeostasis. Here, we report a method for generating human induced pluripotent stem cell (iPSC)-derived mesenchymal cells (iMESs) that can induce human iPSC-derived alveolar and airway epithelial lineages in organoids via epithelial-mesenchymal interaction, without the use of allogenic fetal lung fibroblasts. Through a transcriptome comparison of dermal and lung fibroblasts with their corresponding reprogrammed iPSC-derived iMESs, we found that iMESs had features of lung mesenchyme with the potential to induce alveolar type 2 (AT2) cells. Particularly, RSPO2 and RSPO3 expressed in iMESs directly contributed to AT2 cell induction during organoid formation. We demonstrated that the total iPSC-derived alveolar organoids were useful for characterizing responses to the influenza A (H1N1) virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, demonstrating their utility for disease modeling

Disease modeling of pulmonary fibrosis using human pluripotent stem cell-derived alveolar organoids

iPS細胞を用いて作製した肺胞オルガノイドで間質性肺炎の病態再現に成功 --治療満足度の低い間質性肺炎の治療薬開発に向けて前進--. 京都大学プレスリリース. 2021-11-19.Although alveolar epithelial cells play a critical role in the pathogenesis of pulmonary fibrosis, few practical in vitro models exist to study them. Here, we established a novel in vitro pulmonary fibrosis model using alveolar organoids consisting of human pluripotent stem cell-derived alveolar epithelial cells and primary human lung fibroblasts. In this human model, bleomycin treatment induced phenotypes such as epithelial cell-mediated fibroblast activation, cellular senescence, and presence of alveolar epithelial cells in abnormal differentiation states. Chemical screening performed to target these abnormalities showed that inhibition of ALK5 or blocking of integrin αVβ6 ameliorated the fibrogenic changes in the alveolar organoids. Furthermore, organoid contraction and extracellular matrix accumulation in the model recapitulated the pathological changes observed in pulmonary fibrosis. This human model may therefore accelerate the development of highly effective therapeutic agents for otherwise incurable pulmonary fibrosis by targeting alveolar epithelial cells and epithelial-mesenchymal interactions