Human iPS cell-derived cartilaginous tissue spatially and functionally replaces nucleus pulposus

The loss of nucleus pulposus (NP) precedes the intervertebral disk (IVD) degeneration that causes back pain. Here, we demonstrate that the implantation of human iPS cell-derived cartilaginous tissue (hiPS-Cart) restores this loss by replacing lost NP spatially and functionally. NP cells consist of notochordal NP cells and chondrocyte-like NP cells. Single cell RNA sequencing (scRNA-seq) analysis revealed that cells in hiPS-Cart corresponded to chondrocyte-like NP cells but not to notochordal NP cells. The implantation of hiPS-Cart into a nuclectomized space of IVD in nude rats prevented the degeneration of the IVD and preserved its mechanical properties. hiPS-Cart survived and occupied the nuclectomized space for at least six months after implantation, indicating spatial and functional replacement of lost NP by hiPS-Cart. Further scRNA-seq analysis revealed that hiPS-Cart cells changed their profile after implantation, differentiating into two lineages that are metabolically distinct from each other. However, post-implanted hiPS-Cart cells corresponded to chondrocyte-like NP cells only and did not develop into notochordal NP cells, suggesting that chondrocyte-like NP cells are nearly sufficient for NP function. The data collectively indicate that hiPS-Cart is a candidate implant for regenerating NP spatially and functionally and preventing IVD degeneration.Kamatani T., Hagizawa H., Yarimitsu S., et al. Human iPS cell-derived cartilaginous tissue spatially and functionally replaces nucleus pulposus. Biomaterials 284, 121491 (2022); https://doi.org/10.1016/j.biomaterials.2022.121491

Human iPS cell-derived cartilaginous tissue spatially and functionally replaces nucleus pulposus

iPS細胞から作った軟骨様髄核により椎間板を再生 --椎間板変性に伴う腰痛疾患を治療しうる新技術--. 京都大学プレスリリース. 2022-04-18.The loss of nucleus pulposus (NP) precedes the intervertebral disk (IVD) degeneration that causes back pain. Here, we demonstrate that the implantation of human iPS cell-derived cartilaginous tissue (hiPS-Cart) restores this loss by replacing lost NP spatially and functionally. NP cells consist of notochordal NP cells and chondrocyte-like NP cells. Single cell RNA sequencing (scRNA-seq) analysis revealed that cells in hiPS-Cart corresponded to chondrocyte-like NP cells but not to notochordal NP cells. The implantation of hiPS-Cart into a nuclectomized space of IVD in nude rats prevented the degeneration of the IVD and preserved its mechanical properties. hiPS-Cart survived and occupied the nuclectomized space for at least six months after implantation, indicating spatial and functional replacement of lost NP by hiPS-Cart. Further scRNA-seq analysis revealed that hiPS-Cart cells changed their profile after implantation, differentiating into two lineages that are metabolically distinct from each other. However, post-implanted hiPS-Cart cells corresponded to chondrocyte-like NP cells only and did not develop into notochordal NP cells, suggesting that chondrocyte-like NP cells are nearly sufficient for NP function. The data collectively indicate that hiPS-Cart is a candidate implant for regenerating NP spatially and functionally and preventing IVD degeneration

Characterization of Peripheral Blood TCR in Patients with Type 1 Diabetes Mellitus by BD RhapsodyTM VDJ CDR3 Assay

The sequence of complementarity-determining region 3 of the T-cell receptor (TCR) varies widely due to the insertion of random bases during V-(D)-J recombination. In this study, we used single-cell VDJ sequencing using the latest technology, BD Rhapsody, to identify the TCR sequences of autoreactive T-cells characteristic of Japanese type 1 diabetes mellitus (T1DM) and to clarify the pairing of TCR of peripheral blood mononuclear cells from four patients with T1DM at the single-cell level. The expression levels of the TCR alpha variable (TRAV) 17 and TRAV21 in T1DM patients were higher than those in healthy Japanese subjects. Furthermore, the Shannon index of CD8+ T cells and FOXP3+ cells in T1DM patients was lower than that of healthy subjects. The gene expression of PRF1, GZMH, ITGB2, NKG7, CTSW, and CST7 was increased, while the expression of CD4, CD7, CD5, HLA-A, CD27, and IL-32 was decreased in the CD8+ T cells of T1DM patients. The upregulated gene expression was IL4R and TNFRSF4 in FOXP3+ cells of T1DM patients. Overall, these findings demonstrate that TCR diversity and gene expression of CD8+ and FOXP3+ cells are different in patients with T1DM and healthy subjects

Minimal Residual Disease Detected by the 7NB-mRNAs ddPCR Assay Is Associated with Disease Progression in High-Risk Neuroblastoma Patients: A Prospective Multicenter Observational Study in Japan

High-risk neuroblastoma (HR-NB) patients remain far from obtaining optimal outcomes, with more than 50% relapse/regrowth rate despite current intensive multimodal therapy. This originated from the activation/proliferation of chemoresistant minimal residual disease (MRD). MRD with a significant prognostic was reported by several quantitative PCR (qPCR) or droplet digital PCR (ddPCR) assays quantitating different sets of NB-associated mRNAs (NB-mRNAs). The 7NB-mRNAs ddPCR assay quantitating CRMP1, DBH, DDC, GAP43, ISL1, PHOX2B, and TH mRNAs was reported to outperform other qPCR assays by a retrospective in-house observational study. In the present study, the Japan Children’s Cancer Group (JCCG) Neuroblastoma Committee conducted a prospective multicenter observational study aimed at evaluating a prognostic value of MRD in bone marrow (BM-MRD) and peripheral blood (PB-MRD) detected by 7NB-mRNAs ddPCR assay. Between August 2018 and August 2022, 7 HR-NB patients who registered for JCCG clinical trials (JN-H-11 and JN-H-15) were enrolled. A total of 19 BM and 19 PB samples were collected, and 4/15 BM and 4/15 PB samples were classified as progressive disease (PD)/non-PD samples. BM-MRD and PB-MRD estimated area under curve (AUC) of 0.767 and 0.800 with a significant accuracy (AUC > 0.7). The present study validated a prognostic value of BM-MRD obtained by a previous study (AUC 0.723) and revealed the significant accuracy of PB-MRD as well as BM-MRD

Secondary cancers after a childhood cancer diagnosis: a nationwide hospital-based retrospective cohort study in Japan

BackgroundThe epidemiology of secondary cancers in childhood cancer survivors has been unknown in Asian countries. Our aim is to assess the incidence and risk factors for secondary cancers through a nationwide survey in Japan.\nMethodsA retrospective cohort study comprising 10,069 children who were diagnosed with cancer between 1980 and 2009 was conducted in 15 Japanese hospitals. The cumulative incidence rate was calculated using death as the competing risk and compared by the Gray method. The standardized incidence ratio (SIR) was defined as the ratio of the number of observed cancers divided by the number of expected cancers. The risk factors were analyzed using Cox regression analysis.\nResultsOne hundred and twenty-eight patients (1.3 %) developed secondary cancers within a median follow-up of 8.4 years. The cumulative incidence rate was 1.1 % (95 % confidence interval [CI] 0.9–1.4) at 10 years and 2.6 % (95 % CI 2.1–3.3) at 20 years after primary cancer diagnosis. Sensitivity analysis, limited to 5-year survivors (n = 5,387), confirmed these low incidence rates. The SIR of secondary cancers was 12.1 (95 % CI 10.1–14.4). In the Cox analysis, the hazard ratios for secondary cancers were 3.81 (95 % CI 1.53–9.47) for retinoblastoma, 2.78 (95 % CI 1.44–5.38) for bone/soft tissue sarcomas, and 1.81 (95 % CI 1.16–2.83) for allogeneic stem cell transplantation.\nConclusionsThe cumulative incidence of secondary cancers in children in Japan was not high; however, the SIR was relatively high. Retinoblastoma or sarcoma in addition to allogeneic stem cell transplantation were significant risk factors for secondary cancers