Islet-like Cell Research Articles

Formation of Re-Aggregated Neonatal Porcine Islet Clusters Improves In Vitro Function and Transplantation Outcome.

Neonatal porcine islet-like cell clusters (NPICCs) are a promising source for islet cell transplantation. Excellent islet quality is important to achieve a cure for type 1 diabetes. We investigated formation of cell clusters from dispersed NPICCs on microwell cell culture plates, evaluated the composition of re-aggregated porcine islets (REPIs) and compared in vivo function by transplantation into diabetic NOD-SCID IL2rγ-/- (NSG) mice with native NPICCs. Dissociation of NPICCs into single cells and re-aggregation resulted in the formation of uniform REPI clusters. A higher prevalence of normoglycemia was observed in diabetic NSG mice after transplantation with a limited number (n = 1500) of REPIs (85.7%) versus NPICCs (n = 1500) (33.3%) (p < 0.05). Transplanted REPIs and NPICCs displayed a similar architecture of endocrine and endothelial cells. Intraperitoneal glucose tolerance tests revealed an improved beta cell function after transplantation of 1500 REPIs (AUC glucose 0-120min 6260 ± 305.3) as compared to transplantation of 3000 native NPICCs (AUC glucose 0-120min 8073 ± 536.2) (p < 0.01). Re-aggregation of single cells from dissociated NPICCs generates cell clusters with excellent functionality and improved in vivo function as compared to native NPICCs.

Transcription and splicing regulation by NLRC5 shape the interferon response in human pancreatic β cells.

IFNα is a key regulator of the dialogue between pancreatic β cells and the immune system in early type 1 diabetes (T1D). IFNα up-regulates HLA class I expression in human β cells, fostering autoantigen presentation to the immune system. We observed by bulk and single-cell RNA sequencing that exposure of human induced pluripotent-derived islet-like cells to IFNα induces expression of HLA class I and of other genes involved in antigen presentation, including the transcriptional activator NLRC5. We next evaluated the global role of NLRC5 in human insulin-producing EndoC-βH1 and human islet cells by RNA sequencing and targeted gene/protein determination. NLRC5 regulates expression of HLA class I, antigen presentation–related genes, and chemokines. NLRC5 also mediates the effects of IFNα on alternative splicing, a generator of β cell neoantigens, suggesting that it is a central player of the effects of IFNα on β cells that contribute to trigger and amplify autoimmunity in T1D.

Deducing Insulin-Producing Cells from Goat Adipose Tissue-Derived Mesenchymal Stem Cells.

Mesenchymal stem cell is a potent tool for regenerative medicine against control of incurable diseases in human and animals. Diabetes mellitus is one such condition marked with the blood glucose is high due to lack of insulin (INS) hormone secreted by the pancreatic cells. Rare, but sporadic, cases of dysfunctional pancreatic cells in goat as well as the promises of stem cell therapy as an off-the-shelf medicine prompted us to explore the potential of adipose-derived goat mesenchymal stem cells (AD-MSCs) to transdifferentiate into pancreatic islet-like cells. We isolated, in vitro cultured, and characterized the AD-MSCs by expression of MSC-specific markers and differentiation into multiple mesodermal lineage cells. The characterized AD-MSCs were in vitro transdifferentiated into INS-producing islet-like cells using a cocktail of glucose, nicotinamide, activin-A, exendin-4, pentagastrin, retinoic acid, and mercaptoethanol in 3 weeks. The transdifferentiated islet-like cells demonstrated the expression of pancreatic endoderm-specific transcripts PDX1, NGN3, PAX6, PAX4, ISL1, and GLUT2 as well as protein expression of pancreatic and duodenal homeobox 1 (PDX1), INS, and Islets 1 (ISL1). The islet-like cells also demonstrated the significant glucose-dependent INS release with respect to the course of transdifferentiation regime. The study envisaged to create the building material for basic research into mechanism of glucose homeostasis, which may pave road for developments in diabetes drug discovery and regenerative therapies.

Viability and Functionality of Neonatal Porcine Islet-like Cell Clusters Bioprinted in Alginate-Based Bioinks

The transplantation of pancreatic islets can prevent severe long-term complications in diabetes mellitus type 1 patients. With respect to a shortage of donor organs, the transplantation of xenogeneic islets is highly attractive. To avoid rejection, islets can be encapsulated in immuno-protective hydrogel-macrocapsules, whereby 3D bioprinted structures with macropores allow for a high surface-to-volume ratio and reduced diffusion distances. In the present study, we applied 3D bioprinting to encapsulate the potentially clinically applicable neonatal porcine islet-like cell clusters (NICC) in alginate-methylcellulose. The material was additionally supplemented with bovine serum albumin or the human blood plasma derivatives platelet lysate and fresh frozen plasma. NICC were analysed for viability, proliferation, the presence of hormones, and the release of insulin in reaction to glucose stimulation. Bioprinted NICC are homogeneously distributed, remain morphologically intact, and show a comparable viability and proliferation to control NICC. The number of insulin-positive cells is comparable between the groups and over time. The amount of insulin release increases over time and is released in response to glucose stimulation over 4 weeks. In summary, we show the successful bioprinting of NICC and could demonstrate functionality over the long-term in vitro. Supplementation resulted in a trend for higher viability, but no additional benefit on functionality was observed.

301-OR: Modeling the Type 2 Diabetes–Associated ABCC8 Arg1420 His Mutation using iPSC–Derived Pancreatic Islet-Like Cells

Genetic studies in American Indians from Arizona previously identified a population specific Arg1420 His mutation in ABCC8 which causes hyperinsulinemic hypoglycemia in infancy. The His allele is carried by 3% of this population and associates with increased birthweight, suggesting increased insulin secretion in-utero, and doubles the risk of type 2 diabetes, a disease characterized by reduced insulin secretion. To model the contrary effects of this mutation, we used gene-edited induced pluripotent stem cell (iPSC) derived pancreatic islet-like cells. An iPS cell line created from an American Indian heterozygous for the mutation was gene-edited using CRISPR-CAS9 to generate iPSCs homozygous for the risk (His) and the non-risk (Arg) allele. Multiple iPSC lines for each genotype were differentiated towards pancreatic islet-like cells using a seven-stage differentiation protocol and the effect of the mutation on islet function were assessed. Higher insulin secretion was observed from the His-allele carrying islet-like cells when stimulated with low glucose (2mM) after 1 and 2 weeks of maturation, consistent with a clinical phenotype of hyperinsulinemia in His-allele carriers. Stimulation with 20mM glucose resulted in increased insulin secretion after 2 weeks of maturation only in the Arg-allele (non-risk) carrying islets while no increase was seen in the His-allele carrying islets, consistent with its role in T2D risk. Treatment with diazoxide significantly reduced insulin secretion with no difference between the genotypes. Single cell RNA sequencing of islet-like cells cultured for an extended time (4 weeks) identified many differentially expressed genes in cells with the mutant vs. reference allele that could potentially reveal the mechanism of the increased future T2D risk including G6PC2, a known negative regulator of glucose-stimulated insulin secretion, in beta-like cells and CRH, which has been linked to increased T2D risk, in alpha-like cells. Disclosure A.K.Nair: None. M.Traurig: None. J.Sutherland: Stock/Shareholder; Bristol-Myers Squibb Company, Johnson &amp; Johnson, Pfizer Inc. R.G.Nelson: None. C.Bogardus: None. L.Baier: None. Funding NIH Intramural

The microenvironment of silk/gelatin nanofibrous scaffold improves proliferation and differentiation of Wharton’s jelly-derived mesenchymal cells into islet-like cells

The use of umbilical cord-derived mesenchymal stem cells along with three-dimensional (3D) scaffolds in pancreatic tissue engineering can be considered as a treatment for diabetes. This study aimed to investigate the differentiation of Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) into pancreatic islet-insulin producing cells (IPCs) on silk/gelatin nanofibers as a 3D scaffold. Mesenchymal markers were evaluated at the mesenchymal stem cells (MSCs) level by flow cytometry. WJ-MSCs were then cultured on 3D scaffolds and treated with a differential medium. Immunocytochemical assays showed efficient differentiation of WJ-MSCs into IPCs. Also, Real-time PCR results showed a significant increase in the expression of pancreatic genes in the 3D culture group compared to the two-dimensional (2D) culture group. Despite these cases, the secretion of insulin and C-peptide in response to different concentrations of glucose in the 3D group was significantly higher than in the 2D culture. The results of our study showed that silk/gelatin scaffold with WJ-MSCs could be a good option in the production of IPCs in regenerative medicine and pancreatic tissue engineering.

Generation of Isogenic hiPSCs with Targeted Edits at Multiple Intronic SNPs to Study the Effects of the Type 2 Diabetes Associated KCNQ1 Locus in American Indians.

The top genetic association signal for type 2 diabetes (T2D) in Southwestern American Indians maps to intron 15 of KCNQ1, an imprinted gene. We aim to understand the biology whereby variation at this locus affects T2D specifically in this genomic background. To do so, we obtained human induced pluripotent stem cells (hiPSC) derived from American Indians. Using these iPSCs, we show that imprinting of KCNQ1 and CDKN1C during pancreatic islet-like cell generation from iPSCs is consistent with known imprinting patterns in fetal pancreas and adult islets and therefore is an ideal model system to study this locus. In this report, we detail the use of allele-specific guide RNAs and CRISPR to generate isogenic hiPSCs that differ only at multiple T2D associated intronic SNPs at this locus which can be used to elucidate their functional effects. Characterization of these isogenic hiPSCs identified a few aberrant cell lines; namely cell lines with large hemizygous deletions in the putative functional region of KCNQ1 and cell lines hypomethylated at the KCNQ1OT1 promoter. Comparison of an isogenic cell line with a hemizygous deletion to the parental cell line identified CDKN1C and H19 as differentially expressed during the endocrine progenitor stage of pancreatic-islet development.

A novel hybrid polymer of PCL/fish gelatin nanofibrous scaffold improves proliferation and differentiation of Wharton's jelly-derived mesenchymal cells into islet-like cells.

Using a different source of stem cells to compensate for the lost beta cells is a promising way to cure diabetic patients. Besides, the best efficiency of insulin-producing cells (IPCs) will appear when we culture them in an environment similar to inside the body. Hence, three-dimensional (3D) culture ameliorates the differentiation of diverse kinds of stem cells into IPCs compared to those differentiated in two-dimensional (2D) culture. In this study, we aim to create an ideal differentiation environment by using PCL/Fish gelatin nanofibrous scaffolds to differentiate Wharton's jelly-derived mesenchymal cells (WJ-MSCs) to IPCs and compare them with a 2D cultured group. The evaluation of cellular, molecular, and functional properties of differentiated cells on the 3D and 2D cultures was investigated by several assays such as electron microscopy, quantitative PCR, immunochemistry, western blotting, and ELISA. The in vitro studies showed that WJ-MSCs differentiated in the 3D culture have strong properties of IPCs such as islet-like cells. The expression of pancreatic-specific genes at both RNA and protein levels showed higher differentiation efficacy of 3D culture. Besides, the results of the ELISA tests demonstrate that in both groups the differentiated cells are functional and secreted C-peptide and insulin in glucose stimulation, but the secretion of C-peptide and insulin in the 3D culture group was higher than those cultured in 2D groups. Our findings showed the use of PCL/Fish gelatin nanofibrous scaffolds with optimized differentiation protocols can promote the differentiation of IPCs from WJ-MSCs compared to the 2D culture group.

Characterization and reduction of non-endocrine cells accompanying islet-like endocrine cells differentiated from human iPSC

The differentiation of pancreatic endocrine cells from human pluripotent stem cells has been thoroughly investigated for their application in cell therapy against diabetes. Although non-endocrine cells are inevitable contaminating by-products of the differentiation process, a comprehensive profile of such cells is lacking. Therefore, we characterized non-endocrine cells in iPSC-derived pancreatic islet cells (iPIC) using single-cell transcriptomic analysis. We found that non-endocrine cells consist of (1) heterogeneous proliferating cells, and (2) cells with not only pancreatic traits but also liver or intestinal traits marked by FGB or AGR2. Non-endocrine cells specifically expressed FGFR2, PLK1, and LDHB. We demonstrated that inhibition of pathways involving these genes selectively reduced the number of non-endocrine cells in the differentiation process. These findings provide useful insights into cell purification approaches and contribute to the improvement of the mass production of endocrine cells for stem cell-derived cell therapy for diabetes.

Chromatin Immunoprecipitation in Human Pluripotent Stem Cell-Derived 3D Organoids to Analyze DNA-Protein Interactions.

Chromatin immunoprecipitation (ChIP) is a technique that has been widely used to interrogate DNA-protein interactions in cells. In recent years, human pluripotent stem cell (hPSC)-derived 3D organoids have emerged as a powerful model to understand human development and diseases. Performing ChIP in hPSC-derived 3D organoids is a useful approach to dissect the roles of transcription factors or co-factors and to understand the epigenetic landscape in human development and diseases. However, performing ChIP in 3D organoids is more challenging than monolayer cultures, and an optimized protocol is needed for interpretable data. Hence, in this chapter, we describe in detail a protocol for performing ChIP in hPSC-derived islet-like cells as an example, from organoid harvest to ChIP-qPCR data analysis. This chapter also highlights potential pitfalls and provides recommendations for troubleshooting.

209.4: Characterizing the Therapeutic Potential of Human Pluripotent Stem Cell-derived Islet-like Cells Lacking Cell-Surface HLA Expression

Introduction: While islet or pancreas transplantation remains the optimal way of restoring physiologic blood glucose control in patients with Type 1 diabetes, these therapies are limited by a scarcity of organs available for transplantation and the requirement for immunosuppression to prevent rejection. Recently, effective methods to generate functional islet-like cells (ILCs) from human pluripotent stem cells (hPSCs) have been developed, which opens the possibility for organ replacement without the limitation of scarcity. However, hPSC-derived ILCs would still be expected to be rejected without immunosuppression, which would increase the toxicity associated with this therapy. Because HLA proteins are considered to be primary triggers of allorecognition and rejection, we sought to determine whether hPSCs deficient for cell-surface HLA class I and II expression could differentiate into ILCs less prone to allorejection. Methods: We differentiated HLA-control and HLA-deficient hPSCs into ILCs using an optimized 23 day differentiation protocol. Cells were characterized for pancreatic islet markers, cell surface HLA antigens, and co-stimulatory ligands by flow cytometry. The allo-immunogenicity of control and HLA-deficient ILCs was determined by their ability to induce proliferation, as assessed by CFSE dilution, in allogeneic CD4+ and CD8+ T cells isolated from healthy donor peripheral blood mononuclear cells. Results: We found that HLA-deficient hPSCs exhibited no impairment in their differentiation into ILCs, with both control and HLA-deficient hPSCs generating populations with >90% expression of the endocrine marker Chromogranin A, as assessed by flow cytometry (Figure 1). Unexpectedly, HLA-deficient hPSCs contained a higher proportion of NKX6.1+CPEP+ beta-like cells compared with control hPSCs (p = 0.03). HLA-control ILCs, HLA-deficient ILCs, and primary human islets had similar cell-surface expression of immunomodulatory ligands, with the notable exception that only HLA-deficient ILCs did not express any HLA class I. Upon co-culture with primary allogeneic T cells, control ILCs induced robust activation of CD8+ T cells isolated from 3 out of 4 healthy donors, while HLA-deficient ILCs were not able to induce activation in any of the 4 donors (Figure 2).Discussion/Conclusion: We have found that HLA-deficient hPSCs exhibit no impairment in the ability to differentiate into ILC, and that HLA-deficient ILCs have advantageous immunologic properties. This suggests that patients treated with these cells may not require as much immunosuppression to avoid allorejection. HLA-deficient ILCs may thus be superior candidates for clinical translation for the treatment of type 1 diabetes.

In vitro Induction of Human Dental Pulp Stem Cells Toward Pancreatic Lineages.

As of 2000, the success of pancreatic islet transplantation using the Edmonton protocol to treat type I diabetes mellitus still faced some obstacles. These include the limited number of cadaveric pancreas donors and the long-term use of immunosuppressants. Mesenchymal stem cells (MSCs) have been considered to be a potential candidate as an alternative source of islet-like cell generation. Our previous reports have successfully illustrated the establishment of induction protocols for differentiating human dental pulp stem cells (hDPSCs) to insulin-producing cells (IPCs). However, the induction efficiency varied greatly. In this paper, we demonstrate the comparison of hDPSCs pancreatic induction efficiency via integrative (microenvironmental and genetic manipulation) and non-integrative (microenvironmental manipulation) induction protocols for delivering hDPSC-derived IPCs (hDPSC-IPCs). The results suggest distinct induction efficiency for both the induction approaches in terms of 3-dimensional colony structure, yield, pancreatic mRNA markers, and functional property upon multi-dosage glucose challenge. These findings will support the future establishment of a clinically applicable IPCs and pancreatic lineage production platform.

Far-red light-activated human islet-like designer cells enable sustained fine-tuned secretion of insulin for glucose control

Diabetes affects almost half a billion people, and all individuals with type 1 diabetes (T1D) and a large portion of individuals with type 2 diabetes rely on self-administration of the peptide hormone insulin to achieve glucose control. However, this treatment modality has cumbersome storage and equipment requirements and is susceptible to fatal user error. Here, reasoning that a cell-based therapy could be coupled to an external induction circuit for blood glucose control, as a proof of concept we developed far-red light (FRL)-activated human islet-like designer (FAID) cells and demonstrated how FAID cell implants achieved safe and sustained glucose control in diabetic model mice. Specifically, by introducing a FRL-triggered optogenetic device into human mesenchymal stem cells (hMSCs), which we encapsulated in poly-(l-lysine)-alginate and implanted subcutaneously under the dorsum of T1D model mice, we achieved FRL illumination-inducible secretion of insulin that yielded improvements in glucose tolerance and sustained blood glucose control over traditional insulin glargine treatment. Moreover, the FAID cell implants attenuated both oxidative stress and development of multiple diabetes-related complications in kidneys. This optogenetics-controlled "living cell factory" platform could be harnessed to develop multiple synthetic designer therapeutic cells to achieve long-term yet precisely controllable drug delivery.

Comparison on the curative effect of human placenta-derived mesenchymal stem cells and induced islet-like cells in gestational diabetes mellitus rats

Comparison on the curative effect of human placenta-derived mesenchymal stem cells and induced islet-like cells in gestational diabetes mellitus rats

Differentiation of Human-Induced Pluripotent Stem Cell-Derived Endocrine Progenitors to Islet-like Cells Using a Dialysis Suspension Culture System.

The production of functional islet-like cells from human-induced pluripotent stem cells (hiPSCs) is a promising strategy for the therapeutic use and disease modeling for type 1 diabetes. However, the production cost of islet-like cells is extremely high due to the use of expensive growth factors for differentiation. In a conventional culture method, growth factors and beneficial autocrine factors remaining in the culture medium are removed along with toxic metabolites during the medium change, and it limits the efficient utilization of those factors. In this study, we demonstrated that the dialysis suspension culture system is possible to reduce the usage of growth factors to one-third in the differentiation of hiPSC-derived endocrine progenitor cells to islet-like cells by reducing the medium change frequency with the refinement of the culture medium. Furthermore, the expression levels of hormone-secretion-related genes and the efficiency of differentiation were improved with the dialysis suspension culture system, possibly due to the retaining of autocrine factors. In addition, we confirmed several improvements required for the further study of the dialysis culture system. These findings showed the promising possibility of the dialysis suspension culture system for the low-cost production of islet-like cells.

The Feasibility and Applicability of Stem Cell Therapy for the Cure of Type 1 Diabetes.

Stem cell therapy using islet-like insulin-producing cells derived from human pluripotent stem cells has the potential to allow patients with type 1 diabetes to withdraw from insulin therapy. However, several issues exist regarding the use of stem cell therapy to treat type 1 diabetes. In this review, we will focus on the following topics: (1) autoimmune responses during the autologous transplantation of stem cell-derived islet cells, (2) a comparison of stem cell therapy with insulin injection therapy, (3) the impact of the islet microenvironment on stem cell-derived islet cells, and (4) the cost-effectiveness of stem cell-derived islet cell transplantation. Based on these various viewpoints, we will discuss what is required to perform stem cell therapy for patients with type 1 diabetes.

A new shortened protocol to obtain islet-like cells from hESC-derived ductal cells.

Conventional methods for obtaining pancreatic β cells are based on simulating the embryonic development phase of endocrine cells via hierarchical differentiation of pluripotent stem cells (PSCs). Accordingly, we attempted to modify the protocols for obtaining insulin-secreting cells (ISCs) by sequential differentiation of a human embryonic stem cell (hESC), using the HS181 cell line. Furthermore, we hypothesize that actual pancreatic endocrine cells may arise from trans-differentiation of mature ductal cells after the embryonic developmental stage and throughout the rest of life. According to the hypothesis, ductal cells are trans-differentiated into endocrine and exocrine cells, undergoing a partial epithelial to mesenchymal transition (EMT). To address this issue, we developed two new protocols based on hESC differentiation to obtain ductal cells and then induce EMT in cells to obtain hormone-secreting islet-like cells (HSCs). The ductal (pre-EMT exocrine) cells were then induced to undergo partial EMT by treating with Wnt3a and activin A, in hypoxia. The cell derived from the latter method significantly expressed the main endocrine cell-specific markers and also β cells, in particular. These experiments not only support our hypothetical model but also offer a promising approach to develop new methods to compensate β cell depletion in patients with type 1 diabetes mellitus (T1DM). Although this protocol of generating islet-like cells from ductal cells has a potential to treat T1DM, this strategy may be exploited to optimize the function of these cells in an animal model and future clinical applications.

MicroRNA-365-3p inhibits bone marrow mesenchymal stem cell differentiation into islet-like cell clusters via targeting Pax6 and inhibiting the MEK/ERK pathway.

Diabetes has severe impacts on the health of patients. The differentiation of mesenchymal stem cells (MSCs) into islet-like cell clusters (ICCs) is an effective protocol for the treatment of diabetes. microRNAs (miRs) regulate multiple cellular processes including cell differentiation. This study sought to identify the mechanism of miR-365-3p in the differentiation of bone marrow MSCs (bMSCs) into ICCs. Initially, the differentiation of bMSCs into ICCs was induced. Then, the miR-365-3p expression pattern in the bMSCs and ICCs was detected. Next, the miR-365-3p expression pattern was silenced in bMSCs to assess the effect on differentiation efficiency and measure the expressions of ICC marker genes during the differentiation of bMSCs into ICCs. The miR-365-3p downstream target genes were predicted and verified. Paired box protein 6 (Pax6) was downregulated in bMSCs with silenced miR-365-3p to evaluate the differentiation of bMSCs into ICCs. Furthermore, the Pax6 downstream pathway was evaluated. The differentiation of bMSCs into ICCs was successfully induced. The miR-365-3p expression in bMSCs was higher than that in ICCs. miR-365-3p downregulation in bMSCs facilitated the differentiation of bMSCs into ICCs, as evidenced by elevated releases of insulin and C-peptide in ICCs and elevated expressions of ICC marker genes. Our findings denoted that miR-365-3p targeted Pax6. Inhibition of Pax6 expression annulled the promotion of miR-365-3p downregulation on the differentiation of bMSCs into ICCs. Increased phosphorylation levels of MEK and ERK were identified in ICCs after downregulation of miR-365-3p however they were decreased after downregulation of Pax6. This study supported that miR-365-3p inhibited the differentiation of bMSCs into ICCs via targeting Pax6 and inhibiting the MEK/ERK pathway.

An in vitro Perfused Macroencapsulation Device to Study Hemocompatibility and Survival of Islet-Like Cell Clusters.

Transplantation of hydrogel-encapsulated pancreatic islets is a promising long-term treatment for type 1 diabetes that restores blood glucose regulation while providing graft immunoprotection. Most human-scale islet encapsulation devices that rely solely on diffusion fail to provide sufficient surface area to meet islet oxygen demands. Perfused macroencapsulation devices use blood flow to mitigate oxygen limitations but increase the complexity of blood-device interactions. Here we describe a human-scale in vitro perfusion system to study hemocompatibility and performance of islet-like cell clusters (ILCs) in alginate hydrogel. A cylindrical perfusion device was designed for multi-day culture without leakage, contamination, or flow occlusion. Rat blood perfusion was assessed for prothrombin time and international normalized ratio and demonstrated no significant change in clotting time. Ex vivo perfusion performed with rats showed patency of the device for over 100 min using Doppler ultrasound imaging. PET-CT imaging of the device successfully visualized metabolically active mouse insulinoma 6 ILCs. ILCs cultured for 7 days under static conditions exhibited abnormal morphology and increased activated caspase-3 staining when compared with the perfused device. These findings reinforce the need for convective transport in macroencapsulation strategies and offer a robust and versatile in vitro system to better inform preclinical design.

Human Liver Stem Cells: A Liver-Derived Mesenchymal Stromal Cell-Like Population With Pro-regenerative Properties.

Human liver stem cells (HLSCs) were described for the first time in 2006 as a new stem cell population derived from healthy human livers. Like mesenchymal stromal cells, HLSCs exhibit multipotent and immunomodulatory properties. HLSCs can differentiate into several lineages under defined in vitro conditions, such as mature hepatocytes, osteocytes, endothelial cells, and islet-like cell organoids. Over the years, HLSCs have been shown to contribute to tissue repair and regeneration in different in vivo models, leading to more than five granted patents and over 15 peer reviewed scientific articles elucidating their potential therapeutic role in various experimental pathologies. In addition, HLSCs have recently completed a Phase 1 study evaluating their safety post intrahepatic injection in infants with inherited neonatal onset hyperammonemia. Even though a lot of progress has been made in understanding HLSCs over the past years, some important questions regarding the mechanisms of action remain to be elucidated. Among the mechanisms of interaction of HLSCs with their environment, a paracrine interface has emerged involving extracellular vesicles (EVs) as vehicles for transferring active biological materials. In our group, the EVs derived from HLSCs have been studied in vitro as well as in vivo. Our attention has mainly been focused on understanding the in vivo ability of HLSC–derived EVs as modulators of tissue regeneration, inflammation, fibrosis, and tumor growth. This review article aims to discuss in detail the role of HLSCs and HLSC-EVs in these processes and their possible future therapeutic applications.