scholarly journals Islet organoid as a promising model for diabetes

2021 ◽  
Author(s):  
Xiaofei Zhang ◽  
Zhuo Ma ◽  
Eli Song ◽  
Tao Xu

AbstractStudies on diabetes have long been hampered by a lack of authentic disease models that, ideally, should be unlimited and able to recapitulate the abnormalities involved in the development, structure, and function of human pancreatic islets under pathological conditions. Stem cell-based islet organoids faithfully recapitulate islet development in vitro and provide large amounts of three-dimensional functional islet biomimetic materials with a morphological structure and cellular composition similar to those of native islets. Thus, islet organoids hold great promise for modeling islet development and function, deciphering the mechanisms underlying the onset of diabetes, providing an in vitro human organ model for infection of viruses such as SARS-CoV-2, and contributing to drug screening and autologous islet transplantation. However, the currently established islet organoids are generally immature compared with native islets, and further efforts should be made to improve the heterogeneity and functionality of islet organoids, making it an authentic and informative disease model for diabetes. Here, we review the advances and challenges in the generation of islet organoids, focusing on human pluripotent stem cell-derived islet organoids, and the potential applications of islet organoids as disease models and regenerative therapies for diabetes.

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  

BackgroundAdoptive cell therapies have shown great promise in hematological malignancies but have yielded little progress in the context of solid tumors. We have developed T cell receptor fusion construct (TRuC®) T cells, which are equipped with an engineered T cell receptor that utilizes the full complement of TCR signaling subunits and recognizes tumor-associated antigens independent of HLA. In clinical trials, mesothelin (MSLN)-targeting TRuC-T cells (TC-210 or gavo-cel) have shown unprecedented results in patients suffering from advanced mesothelioma and ovarian cancer. To potentially increase the depth of response, we evaluated strategies that can promote intra-tumoral T cell persistence and function. Among the common ??-chain cytokines, IL-15 uniquely supports the differentiation and maintenance of memory T cell subsets by limiting terminal differentiation and conferring resistance to IL-2 mediated activation-induced cell death (AICD). In the studies described here, we evaluated the potential of IL-15 as an enhancement to TRuC-T cell phenotype, persistence and function against MSLN+ targets.MethodsPrimary human T cells were activated and transduced with a lentiviral vector encoding an anti-MSLN binder fused to CD3ε alone or co-expressed with a membrane-tethered IL-15rα/IL-15 fusion protein (IL-15fu). Transduced T cells were expanded for 9 days and characterized for expression of the TRuC, IL-15rα and memory phenotype before subjecting them to in vitro functional assays to evaluate cytotoxicity, cytokine production, and persistence. In vivo efficacy was evaluated in MHC class I/II deficient NSG mice bearing human mesothelioma xenografts.ResultsIn vitro, co-expression of the IL-15fu led to similar cytotoxicity and cytokine production as TC-210, but notably enhanced T-cell expansion and persistence upon repeated stimulation with MSLN+ cell lines. Furthermore, the IL-15fu-enhanced TRuC-T cells sustained a significantly higher TCF-1+ population and retained a stem-like phenotype following activation. Moreover, the IL-15fu-enhanced TRuCs demonstrated robust in vivo expansion and intra-tumoral accumulation as measured by ex vivo analysis of TRuC+ cells in the tumor and blood, with a preferential expansion of CD8+ T cells. Finally, IL-15fu-enhanced TRuC-T cells could be observed in the blood long after the tumors were cleared.ConclusionsThese pre-clinical studies suggest that the IL-15fu can synergize with TC-210 to increase the potency and durability of response in patients with MSLN+ tumors.Ethics ApprovalAll animal studies were approved by the respective Institutional Animal Care and Use Committees.


2019 ◽  
Vol 125 (10) ◽  
Author(s):  
Gary Gintant ◽  
Paul Burridge ◽  
Lior Gepstein ◽  
Sian Harding ◽  
Todd Herron ◽  
...  

It is now well recognized that many lifesaving oncology drugs may adversely affect the heart and cardiovascular system, including causing irreversible cardiac injury that can result in reduced quality of life. These effects, which may manifest in the short term or long term, are mechanistically not well understood. Research is hampered by the reliance on whole-animal models of cardiotoxicity that may fail to reflect the fundamental biology or cardiotoxic responses of the human myocardium. The emergence of human induced pluripotent stem cell–derived cardiomyocytes as an in vitro research tool holds great promise for understanding drug-induced cardiotoxicity of oncological drugs that may manifest as contractile and electrophysiological dysfunction, as well as structural abnormalities, making it possible to deliver novel drugs free from cardiac liabilities and guide personalized therapy. This article briefly reviews the challenges of cardio-oncology, the strengths and limitations of using human induced pluripotent stem cell–derived cardiomyocytes to represent clinical findings in the nonclinical research space, and future directions for their further use.


2020 ◽  
Vol 21 (19) ◽  
pp. 6997 ◽  
Author(s):  
Davide Rovina ◽  
Elisa Castiglioni ◽  
Francesco Niro ◽  
Sara Mallia ◽  
Giulio Pompilio ◽  
...  

The ultimate goal of precision disease modeling is to artificially recreate the disease of affected people in a highly controllable and adaptable external environment. This field has rapidly advanced which is evident from the application of patient-specific pluripotent stem-cell-derived precision therapies in numerous clinical trials aimed at a diverse set of diseases such as macular degeneration, heart disease, spinal cord injury, graft-versus-host disease, and muscular dystrophy. Despite the existence of semi-adequate treatments for tempering skeletal muscle degeneration in dystrophic patients, nonischemic cardiomyopathy remains one of the primary causes of death. Therefore, cardiovascular cells derived from muscular dystrophy patients’ induced pluripotent stem cells are well suited to mimic dystrophin-associated cardiomyopathy and hold great promise for the development of future fully effective therapies. The purpose of this article is to convey the realities of employing precision disease models of dystrophin-associated cardiomyopathy. This is achieved by discussing, as suggested in the title echoing William Shakespeare’s words, the settlements (or “leagues”) made by researchers to manage the constraints (“betwixt mine eye and heart”) distancing them from achieving a perfect precision disease model.


2018 ◽  
Vol 15 (145) ◽  
pp. 20180388 ◽  
Author(s):  
Hannah Donnelly ◽  
Manuel Salmeron-Sanchez ◽  
Matthew J. Dalby

Mesenchymal stem cells, characterized by their ability to differentiate into skeletal tissues and self-renew, hold great promise for both regenerative medicine and novel therapeutic discovery. However, their regenerative capacity is retained only when in contact with their specialized microenvironment, termed the stem cell niche . Niches provide structural and functional cues that are both biochemical and biophysical, stem cells integrate this complex array of signals with intrinsic regulatory networks to meet physiological demands. Although, some of these regulatory mechanisms remain poorly understood or difficult to harness with traditional culture systems. Biomaterial strategies are being developed that aim to recapitulate stem cell niches, by engineering microenvironments with physiological-like niche properties that aim to elucidate stem cell-regulatory mechanisms, and to harness their regenerative capacity in vitro . In the future, engineered niches will prove important tools for both regenerative medicine and therapeutic discoveries.


2013 ◽  
Vol 45 (23) ◽  
pp. 1123-1135 ◽  
Author(s):  
David A. Brafman

Within the adult organism, stem cells reside in defined anatomical microenvironments called niches. These architecturally diverse microenvironments serve to balance stem cell self-renewal and differentiation. Proper regulation of this balance is instrumental to tissue repair and homeostasis, and any imbalance can potentially lead to diseases such as cancer. Within each of these microenvironments, a myriad of chemical and physical stimuli interact in a complex (synergistic or antagonistic) manner to tightly regulate stem cell fate. The in vitro replication of these in vivo microenvironments will be necessary for the application of stem cells for disease modeling, drug discovery, and regenerative medicine purposes. However, traditional reductionist approaches have only led to the generation of cell culture methods that poorly recapitulate the in vivo microenvironment. To that end, novel engineering and systems biology approaches have allowed for the investigation of the biological and mechanical stimuli that govern stem cell fate. In this review, the application of these technologies for the dissection of stem cell microenvironments will be analyzed. Moreover, the use of these engineering approaches to construct in vitro stem cell microenvironments that precisely control stem cell fate and function will be reviewed. Finally, the emerging trend of using high-throughput, combinatorial methods for the stepwise engineering of stem cell microenvironments will be explored.


Blood ◽  
2010 ◽  
Vol 116 (11) ◽  
pp. 1857-1866 ◽  
Author(s):  
Ilaria Visigalli ◽  
Silvia Ungari ◽  
Sabata Martino ◽  
Hyejung Park ◽  
Martina Cesani ◽  
...  

Abstract The balance between survival and death in many cell types is regulated by small changes in the intracellular content of bioactive sphingolipids. Enzymes that either produce or degrade these sphingolipids control this equilibrium. The findings here described indicate that the lysosomal galactocerebrosidase (GALC) enzyme, defective in globoid cell leukodystrophy, is involved in the maintenance of a functional hematopoietic stem/progenitor cell (HSPC) niche by contributing to the control of the intracellular content of key sphingolipids. Indeed, we show that both insufficient and supraphysiologic GALC activity—by inherited genetic deficiency or forced gene expression in patients' cells and in the disease model—induce alterations of the intracellular content of the bioactive GALC downstream products ceramide and sphingosine, and thus affect HSPC survival and function and the functionality of the stem cell niche. Therefore, GALC and, possibly, other enzymes for the maintenance of niche functionality and health tightly control the concentration of these sphingolipids within HSPCs.


2012 ◽  
Vol 46 (2) ◽  
pp. 75-80
Author(s):  
Shamoli Bhattacharyya

ABSTRACT Mesenchymal stem cells have shown great promise as the source of adult stem cells for regenerative medicine. Present research efforts are directed at isolating these cells from various sources, growing them in vitro and maintaining their pluripotency as well as capacity for self renewal. It is crucial to identify the regulatory molecules which directly or indirectly control the proliferative status or influence the niche microenvironment. The main challenge is to understand the basic biology of the stem cells and manipulate them for further therapeutic applications. Considering their malignant potential, stem cells may be a double edged sword. While the benefits of these cells need to be harnessed judiciously, a significant amount of research is required before embarking on widespread use of this tool for the benefit of humanity. How to cite this article Bhattacharyya S. Advances and Applications in Stem Cell Biology. J Postgrad Med Edu Res 2012;46(2):75-80.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 716-716
Author(s):  
Joanne C. Mountford ◽  
Diane Gilmour ◽  
Susan M. Graham ◽  
Niove E. Jordanides ◽  
Siobhan McMillan ◽  
...  

Abstract We have previously described a population of deeply, but reversibly, quiescent stem cells (qSC) found in patients with chronic phase (CP) CML at diagnosis. In vitro studies have proven this population to be highly insensitive to imatinib mesylate (IM; Gleevec, STI571) induced killing, and more worryingly shown that qSC are accumulated after CML CD34+ cells are treated with IM. As it is likely that CML qSC closely resemble normal HSC, we hypothesise that they too may express the stem cell-associated ABCG2 and have therefore examined the expression and function of this drug efflux pump on CML cells. In agreement with other studies we show the interaction between ABCG2 and IM. Using ABCG2 over-expressing cells (AML6.2 and HL60-BCRP) we found that ≥0.5μM IM reduced efflux of the ABCG2 substrate BODIPY-Prazosin by a similar degree as the inhibitor fumitremorgin C (FTC; 10μM). We have now examined expression and function of ABCG2 on primary CML cells taken from patients in chronic phase (CP) and prior to any treatment. Quantitative Taqman analysis of 8 CD34+ enriched (≥90%+) CML samples revealed that the level of expression is 2.46 fold higher than that in normal mobilised CD34+ cells (n=8 CML, n=4 normal). In addition, we undertook microarray analysis of normal or CML CP CD34+ cells fractionated according to cell cycle using Hoechst-Pyronin (G0, G1 and G2/S/M). These analyses (n=3 normal, n=5 CML) show that at all stages of the cycle CML cells express more ABCG2 than normal cells and that G0 CML cells express 2.48 fold more than those in G1 , confirming both the over-expression in CML and relationship to the most primitive subset of cells. Using the antibody BXP21 we found that 8 of 9 samples contain ABCG2+ve cells (5 of 9 ≥60% of cells ABCG2+). We also examined the function of ABCG2 on CML CD34+ cells by performing efflux assays, 4 of 6 showed efflux that was inhibited by 10μM FTC or ≥0.5μM IM, and this efflux capacity correlated with BXP21 staining. We therefore considered whether the combination of IM therapy and ABCG2 inhibition would overcome the accumulation of CML qSCs we have previously reported after treatment with IM. Using CFSE to track cell division we treated CD34+ enriched CML samples with 5μM IM +/− FTC or with 10μM FTC alone for 3 days. In comparison to untreated controls 5μM IM reduced the total number of cells to 31.9±9.2 % and the number of CD34+ cells to 43.2±17.6%. However, the non-cycling qSC significantly increased to 318±75.8% of control. In contrast, the ABCG2 inhibitor FTC did not effect a reduction in total cells (99.5±11.9%) but gave a significant reduction of CD34+ cells (58.6±8.4%; p=0.02) and no accumulation of qSC (104.6±33.8%) when used alone. We saw no cumulative effect when IM and FTC were given concurrently. These data suggest strongly that FTC may be used to deplete CD34+ ‘stem cells’ from CML, as the total cell number is unchanged it is likely that this depletion is by the induction of differentiation. We propose that the expression of ABCG2 may be clinically significant in CP CML and that inhibition of this pump may result in a ‘stem cell targeted therapy’ that could be followed by IM treatment to reduce the tumor load. Such reduction of CML stem cells would result in elimination of minimal residual disease and effect a lasting remission.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ning Zhang ◽  
Chi-Wen Lo ◽  
Takeshi Utsunomiya ◽  
Masahiro Maruyama ◽  
Ejun Huang ◽  
...  

Abstract Background Mesenchymal stem cell (MSC)-based therapy has the potential for immunomodulation and enhancement of tissue regeneration. Genetically modified MSCs that over-express specific cytokines, growth factors, or chemokines have shown great promise in pre-clinical studies. In this regard, the anti-inflammatory cytokine interleukin (IL)-4 converts pro-inflammatory M1 macrophages into an anti-inflammatory M2 phenotype; M2 macrophages mitigate chronic inflammation and enhance osteogenesis by MSC lineage cells. However, exposure to IL-4 prematurely inhibits osteogenesis of MSCs in vitro; furthermore, IL-4 overexpressing MSCs inhibit osteogenesis in vivo during the acute inflammatory period. Platelet-derived growth factor (PDGF)-BB has been shown to enhance osteogenesis of MSCs with a dose-dependent effect. Methods In this study, we generated a lentiviral vector that produces PDGF-BB under a weak promoter (phosphoglycerate kinase, PGK) and lentiviral vector producing IL-4 under a strong promoter (cytomegalovirus, CMV). We infected MSCs with PDGF-BB and IL-4-producing lentiviral vectors separately or in combination to investigate cell proliferation and viability, protein expression, and the capability for osteogenesis. Results PDGF-BB and IL-4 co-overexpression was observed in the co-infected MSCs and shown to enhance cell proliferation and viability, and osteogenesis compared to IL-4 overexpressing MSCs alone. Conclusions Overexpression of PDGF-BB together with IL-4 mitigates the inhibitory effect of IL-4 on osteogenesis by IL-4 overexpressing MSCS. PDGF-BB and IL-4 overexpressing MSCs may be a potential strategy to facilitate osteogenesis in scenarios of both acute and chronic inflammation.


Sign in / Sign up

Export Citation Format

Share Document