Cartilage has little intrinsic capacity for repair, so transplantation of exogenous cartilage cells is considered a realistic option for cartilage regeneration. We explored whether human-induced... Show moreCartilage has little intrinsic capacity for repair, so transplantation of exogenous cartilage cells is considered a realistic option for cartilage regeneration. We explored whether human-induced pluripotent stem cells (hiPSCs) could represent such unlimited cell sources for neo-cartilage comparable to human primary articular chondrocytes (hPACs) or human bone marrow-derived mesenchymal stromal cells (hBMSCs). For this, chondroprogenitor cells (hiCPCs) and hiPSC-derived mesenchymal stromal cells (hiMSCs) were generated from two independent hiPSC lines and characterized by morphology, flow cytometry, and differentiation potential. Chondrogenesis was compared to hBMSCs and hPACs by histology, immunohistochemistry, and RT-qPCR, while similarities were estimated based on Pearson correlations using a panel of 20 relevant genes. Our data show successful differentiations of hiPSC into hiMSCs and hiCPCs. Characteristic hBMSC markers were shared between hBMSCs and hiMSCs, with the exception of CD146 and CD45. However, neo-cartilage generated from hiMSCs showed low resemblances when compared to hBMSCs (53%) and hPACs (39%) characterized by lower collagen type 2 and higher collagen type 1 expression. Contrarily, hiCPC neo-cartilage generated neo-cartilage more similar to hPACs (65%), with stronger expression of matrix deposition markers. Our study shows that taking a stepwise approach to generate neo-cartilage from hiPSCs via chondroprogenitor cells results in strong similarities to neo-cartilage of hPACs within 3 weeks following chondrogenesis, making them a potential candidate for regenerative therapies. Contrarily, neo-cartilage deposited by hiMSCs seems more prone to hypertrophic characteristics compared to hPACs. We therefore compared chondrocytes derived from hiMSCs and hiCPCs with hPACs and hBMSCs to outline similarities and differences between their neo-cartilage and establish their potential suitability for regenerative medicine and disease modelling. Show less
Barnhoorn, M.C.; Wasser, M.N.J.M.; Roelofs, H.; Maljaars, P.W.J.; Molendijk, I.; Bonsing, B.A.; ... ; Meulen-de Jong, A.E. van der 2020
Background and Aims: The long-term safety and efficacy of allogeneic bone marrow-derived mesenchymal stromal cell [bmMSC] therapy in perianal Crohn's disease [CD] fistulas is unknown. We aimed to... Show moreBackground and Aims: The long-term safety and efficacy of allogeneic bone marrow-derived mesenchymal stromal cell [bmMSC] therapy in perianal Crohn's disease [CD] fistulas is unknown. We aimed to provide a 4-year clinical evaluation of allogeneic bmMSC treatment of perianal CD fistulas.Methods: A double-blind dose-finding study for local bmMSC therapy in 21 patients with refractory perianal fistulising Crohn's disease was performed at the Leiden University Medical Center in 2012-2014. All patients treated with bmMSCs [1 x 10(7) bmMSCs cohort 1, n = 5; 3 x 10(7) bmMSCs cohort 2, n = 5; 9 x 10(7) bmMSCs cohort 3, n = 5] were invited for a 4-year evaluation. Clinical events were registered, fistula closure was evaluated, and anti-human leukocyte antigen [HLA] antibodies were assessed. Patients were also asked to undergo a pelvic magnetic resonance imaging [MRI] and rectoscopy.Results: Thirteen out of 15 patients [87%] treated with bmMSCs were available for long-term follow-up. Two non-MSC related malignancies were observed. No serious adverse events thought to be related to bmMSC therapy were found. In cohort 2 [n = 4], all fistulas were closed 4 years after bmMSC therapy. In cohort 1 [n = 4] 63%, and in cohort 3 [n = 5] 43%, of the fistulas were closed, respectively. In none of the patients anti-HLA antibodies could be detected 24 weeks and 4 years after therapy. Pelvic MRI showed significantly smaller fistula tracts after 4 years.Conclusions: Allogeneic bmMSC therapy for CD-associated perianal fistulas is also in the long-term a safe therapy. In bmMSC-treated patients, fistulas with closure at Week 24 were still closed after 4 years. Show less
Trento, C.; Bernardo, M.E.; Nagler, A.; Kuci, S.; Bornhauser, M.; Kohl, U.; ... ; Dazzi, F. 2018
Mesenchymal stromal cells (MSCs) support hematopoiesis in the bone marrow, are involved in tissue repair and modulate immune responses. The aim of this thesis is to study the function of MSC... Show moreMesenchymal stromal cells (MSCs) support hematopoiesis in the bone marrow, are involved in tissue repair and modulate immune responses. The aim of this thesis is to study the function of MSC derived from children suffering from childhood malignant diseases (Myelodysplastic syndrome (MDS) and Juvenile myelomonocytic leukemia (JMML)) or from systemic juvenile idiopathic arthritis. The MSCs form children with MDS and JMML have an altered RNA expression profile with marked differences in e.g. immunomodulatory genes. These alterations were reversible after hematopoietic stem cell transplantation (HSCT). Our data support the hypothesis that malignant cells profit from the altered bone-marrow microenvironment by escaping the immune defense and occupying the hematopoietic niche. In the future, these mechanisms will be possible targets for therapy. In addition, the impact of MSCs on virus-specific immune recovery and acute graft-versus-host disease (aGvHD) after pediatric allogeneic HSCT has been investigated. We show in the studies described that biopsies of the intestinal tract are essential at diagnosis but also to monitor treatment after experimental therapy. Our data support early treatment with MSCs in steroid refractory aGvHD irrespective of ongoing viral reactivations. These data were used for the design of a multi-center randomized controlled trial with MSCs. Show less
This thesis describes the clinical use and laboratory findings of bone marrow (BM) derived, ex-vivo expanded human Mesenchymal Stromal Cells (MSCs) in pediatric stem cell transplantation. Advances... Show moreThis thesis describes the clinical use and laboratory findings of bone marrow (BM) derived, ex-vivo expanded human Mesenchymal Stromal Cells (MSCs) in pediatric stem cell transplantation. Advances in transplant technologies have permitted the use of __alternative donors__, i.e. haploidentical peripheral blood stem cells and umbilical cord blood, as a source of donor hematopoietic stem cells. MSCs located in the bone marrow form the stromal network, essential for the support of normal hematopoietic stem cell growth and development. Methods to expand MSCs sufficient for clinical uses have recently become available. In vitro experiments show MSCs interact with various cells of both the innate and adaptive immune system, which overall results in the induction of an anti-inflammatory state. The ability of MSCs to support hematopoietic stem cell growth coupled with their potent immune suppressive effects mean that they are ideal candidate cells to explore in the context of overcoming some of the problems specifically associated with the use of alternative donors. In this thesis, we therefore attempted to address the most relevant of these issues that, given the known properties of MSCs, would allow us to assess the possible usefulness of MSCs as an innovative strategy to resolve them. Show less
