Applicability of Adipose-Derived Stem Cells in Type 1 Diabetes Mellitus

The efficiency of stem cell differentiation into functional beta cells for treating insulin-requiring diabetes: Recent advances and current challenges

In recent years, the potential of stem cells (SCs) to differentiate into various types of cells, including β-cells, has led to a significant boost in development. The efficiency of this differentiation process and the functionality of the cells post-transplantation are crucial factors for the success of stem cell therapy in diabetes. Herein, this article reviews the current advances and challenges faced by stem cell differentiation into functional β-cells for diabetes treatment. In vitro, researchers have sought to enhance the differentiation efficiency of functional β-cells by mimicking the normal pancreatic development process, using gene manipulation, pharmacological and culture conditions stimulation, three-dimensional (3D) and organoid culture, or sorting for functional β-cells based on mature islet cell markers. Furthermore, in vivo studies have also looked at suitable transplantation sites, the enhancement of the transplantation microenvironment, immune modulation, and vascular function reconstruction to improve the survival rate of functional β-cells, thereby enhancing the treatment of diabetes. Despite these advancements, developing stem cells to produce functional β-cells for efficacious diabetes treatment is a continuous research endeavor requiring significant multidisciplinary collaboration, for the stem-cell-derived beta cells to evolve into an effective cellular therapy.

Advancements in culture technology of adipose-derived stromal/stem cells: implications for diabetes and its complications

Stem cell-based therapies exhibit considerable promise in the treatment of diabetes and its complications. Extensive research has been dedicated to elucidate the characteristics and potential applications of adipose-derived stromal/stem cells (ASCs). Three-dimensional (3D) culture, characterized by rapid advancements, holds promise for efficacious treatment of diabetes and its complications. Notably, 3D cultured ASCs manifest enhanced cellular properties and functions compared to traditional monolayer-culture. In this review, the factors influencing the biological functions of ASCs during culture are summarized. Additionally, the effects of 3D cultured techniques on cellular properties compared to two-dimensional culture is described. Furthermore, the therapeutic potential of 3D cultured ASCs in diabetes and its complications are discussed to provide insights for future research.

Towards standardization of human adipose-derived stromal cells secretomes

The secretome of adipose-derived stromal cells (ASC) is a heterogeneous mixture of components with a beneficial influence on cellular microenvironments. As such, it represents a cell-free alternative in regenerative medicine therapies. Pathophysiological conditions increase the therapeutic capacity of ASC and, with this, the benefits of the secretome. Such conditions can be partially mimicked in vitro by adjusting culturing conditions. Secretomics, the unbiased analysis of a cell secretome by mass spectrometry, is a powerful tool to describe the composition of ASC secretomes. In this proteomics databases review, we compared ASC secretomic studies to retrieve persistently reported proteins resulting from the most explored types of culturing conditions used in research, i.e., exposure to normoxia, hypoxia, or cytokines. Our comparisons identified only eight common proteins within ASC normoxic secretomes, no commonalities within hypoxic ASC secretomes, and only nine within secretomes of ASC exposed to proinflammatory cytokines. Within these, and regardless of the culturing condition that stimulated secretion, a consistent presence of extracellular matrix-related pathways associated with such proteins was identified. Confounders such as donors' age, sex, body mass index, the anatomical area where ASC were harvested, secretome collection method, data description, and how the data is shared with the scientific community are discussed as factors that might explain our outcomes. We conclude that standardization is imperative as the currently available ASC secretomic studies do not facilitate solid conclusions on the therapeutic value of different ASC secretomes.

The Role of Mesenchymal Stem Cells in the Treatment of Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic disease characterized by inadequate or absent insulin production due to the autoimmune destruction of beta (β) cells in the pancreas. It was once called "juvenile diabetes" since the disease frequently occurs in children, but it can also develop in adults. According to the International Diabetes Federation, an estimated 700 million adults will suffer from diabetes by 2045. Although the exact cause of diabetes remains unknown, it is hypothesized that genetic factors, environmental factors, and exposure to certain viruses play a role in the development of T1D. To date, exogenous insulin is the most common treatment for T1D. However, it is not a cure for the disease. Islet cell transplantation and pancreatic transplantation are two additional treatments that have gained popularity in recent years, but their clinical application may be limited by the need for high doses of immunosuppressants, the rarity of human cadaveric islets, and the need for extensive surgery in pancreatic transplantation. Mesenchymal stem cells (MSCs) are a highly promising novel treatment for T1D and their discovery has advanced biological sciences by allowing for modification of cell fate and the development of higher-order cellular structures. They play an essential role in lowering levels of fasting blood sugar, hemoglobin A1c, and C-peptide, and in treating microvascular complications associated with T1D. However, some of the disadvantages of its use in clinical practice are limited to its method of collection, proliferation rate, cell activity with age, and the risk of tumour formation identified in some studies. Large-scale studies are required to discover the mechanism of action of MSCs after administration as well as the optimal route, dose, and timing to maximize the benefits to patients. This article focuses primarily on the role of MSCs in the treatment of T1D and compares the feasibility, benefits, and drawbacks of MSCs in the treatment of T1D. 

A One-Step, Monolayer Culture and Chemical-Based Approach to Generate Insulin-Producing Cells From Human Adipose-Derived Stem Cells to Mitigate Hyperglycemia in STZ-Induced Diabetic Rats

The global population of individuals afflicted with diabetes mellitus has been increasing year by year, and this disease poses a serious threat to human health as well as the economies worldwide. Pancreatic or islet transplantations provide one of the most effective and long-term therapies available to treat diabetes, but the scarcity and quality of pancreatic islets limit their use in treatments. Here, we report the development of a one-step, monolayer culture, and chemical-based protocol that efficiently mediates the differentiation of human adipose-derived stem cells (hADSCs) into insulin-producing cells (IPCs). Our data indicate that hADSCs in monolayer culture that are allowed to differentiate into IPCs are superior to those in suspension cultures with respect to insulin secretion capacity (213-fold increase), cell viability (93.5 ± 3.27% vs. 41.67 ± 13.17%), and response to glucose stimulation. Moreover, the expression of genes associated with pancreatic lineage specification, such as PDX1, ISL1, and INS (encoding insulin), were expressed at significantly higher levels during our differentiation protocol (6-fold for PDX1 and ISL1, 11.5-fold for INS). Importantly, in vivo studies demonstrated that transplantation with IPCs significantly mitigated hyperglycemia in streptozotocin-induced diabetic rats. Our results indicate that this one-step, rapid protocol increases the efficiency of IPC generation and that the chemical-based approach for IPC induction may reduce safety concerns associated with the use of IPCs for clinical applications, thereby providing a safe and effective cell-based treatment for diabetes.

Immunomodulatory Effect of Adipose-Derived Stem Cells: The Cutting Edge of Clinical Application

Adipose-derived stem cells (ASCs) represent a promising tool for soft tissue engineering as well as for clinical treatment of inflammatory and autoimmune pathologies. The well-characterized multi-differentiation potential and self-renewal properties of ASCs are coupled with their immunomodulatory ability in providing therapeutic efficacy. Yet, their impact in immune or inflammatory disorders might rely both on cell contact-dependent mechanisms and paracrine effects, resulting in the release of various soluble factors that regulate immune cells functions. Despite the widespread use of ASCs in clinical trials addressing several pathologies, the pathophysiological mechanisms at the basis of their clinical use have been not yet fully investigated. In particular, a thorough analysis of ASC immunomodulatory potential is mandatory. Here we explore such molecular mechanisms involved in ASC immunomodulatory properties, emphasizing the relevance of the milieu composition. We review the potential clinical use of ASC secretome as a mediator for immunomodulation, with a focus on in vitro and in vivo environmental conditions affecting clinical outcome. We describe some potential strategies for optimization of ASCs immunomodulatory capacity in clinical settings, which act either on adult stem cells gene expression and local microenvironment. Finally, we discuss the limitations of both allogeneic and autologous ASC use, highlighting the issues to be fixed in order to significantly improve the efficacy of ASC-based cell therapy.

Evolution of ASC Immunophenotypical Subsets During Expansion In Vitro

Adipose-derived stromal/stem cells (ASCs) are currently being considered for clinical use for a number of indications. In order to develop standardized clinical protocols, it is paramount to have a full characterization of the stem cell preparations. The surface marker expression of ASCs has previously been characterized in multiple studies. However, most of these studies have provided a cross-sectional description of ASCs in either earlier or later passages. In this study, we evaluate the dynamic changes of 15 different surface molecules during culture. Using multichromatic flow cytometry, ASCs from three different donors each in passages 1, 2, 4, 6, and 8 were analyzed for their co-expression of markers associated with mesenchymal stem cells, wound healing, immune regulation, ASC markers, and differentiation capacity, respectively. We confirmed that at an early stage, ASC displayed a high heterogeneity with a plethora of subpopulations, which by culturing became more homogeneous. After a few passages, virtually all ASCs expressed CD29, CD166 and CD201, in addition to canonical markers CD73, CD90, and CD105. However, even at passage 8, there were several predominant lineages that differed with respect to the expression of CD34, CD200 and CD271. Although the significance of remaining subpopulations still needs to be elucidated, our results underscore the necessity to fully characterize ASCs prior to clinical use.

Adipose-derived stem cell-conditioned medium protects fibroblasts at different senescent degrees from UVB irradiation damages

Adipose-derived stem cells (ADSCs) and their derivatives have aroused intense interest in fields of dermatological and aesthetic medicine. As a major component detected in ADSCs secretome, platelet-derived growth factor AA (PDGF-AA) has been reported mediating extracellular matrix deposition and remodeling, thus might contribute to its anti-aging effect. On the basis of establishing an experimental model that simulate actual skin aging by exposing HDFs to both intrinsic and extrinsic aging factors, we pretreated human dermal fibroblasts (HDFs) with ADSC-conditioned medium (ADSC-CM) before being irradiated, aiming at exploring preventive effects of ADSCs secretome against aging damages. 48 h after irradiation, we detected cellular proliferation; β-galactosidase stain; mRNA expressions of MMP-1, MMP-9, and TIMP-1; and protein expressions of collagen I, collagen III, and elastin. Moreover, we detected related protein expression of PI3K/Akt signal pathway, which can be activated by PDGF-AA and was newly found to promote extracellular matrix protein synthesis. Concentration of PDGF-AA in the prepared ADSC-CM decreased over time and maintained excellent bioactivity at low temperature until the 11th week. ADSC-CM pretreatment can slightly or significantly improve cellular proliferative activity and reduce cellular senescence in irradiated HDFs. Besides, ADSC-CM pretreatment increased collagen I, collagen III, elastin, and TIMP-1 expressions but decreased MMP-1 and MMP-9 expressions both in irradiated and nonirradiated HDFs. ADSC-CM pretreatment significantly increased pAkt protein expression, and ECM protein expression greatly decreased in case of LY294002 application. The results were similar in three generations of HDFs, yet varied with different degrees. Generally, ADSC-CM we prepared demonstrates a certain degree of positive role in preventing HDFs from intrinsic and extrinsic aging damages and that PDGF-AA may contribute to making it become effective with some other components in ADSC-CM.

lncRNA MALAT1 Accelerates Wound Healing of Diabetic Mice Transfused with Modified Autologous Blood via the HIF-1α Signaling Pathway

Impaired wound healing is a debilitating complication of diabetes. The long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been recognized to be differentially expressed in various diseases. However, its underlying mechanism in diabetes has not been fully understood. Notably, we aim to examine the expression of MALAT1 in diabetic mice and its role in wound healing involving the hypoxia-inducible factor-1α (HIF-1α) signaling pathway with a modified autologous blood preservative solution reported. A mouse model of diabetes was established. MALAT1 was identified to promote the activation of the HIF-1α signaling pathway and to be enriched in autologous blood through modified preservation, which might facilitate the improvement of physiological function of blood cells. Through gain- or loss-of-function approaches, viability of fibroblasts cultured in high glucose, wound healing of mice, and collagen expression in wound areas were enhanced by MALAT1 and HIF-1α. Taken together, the present study demonstrated that the physiological status of mouse blood was effectively improved by modified autologous blood preservation, which exhibited upregulated MALAT1, thereby accelerating the fibroblast activation and wound healing in diabetic mice via the activation of the HIF-1α signaling pathway. The upregulation of MALAT1 activating the HIF-1α signaling pathway provides a novel insight into drug targets against diabetes.

Isolation and Characterization of Pancreatic Canine Fetal Cells at the Final Stage of Gestation

The incidence of diabetes mellitus in dogs is increasing in recent years, mainly because of genetic and/or environmental factors, including endocrine disorders (like in humans); failure of suitable control of blood sugar levels, which triggers hyperglycemia; glycosuria and weight loss, which demands the development of innovative treatments to cure or treat this complex disease in dogs. The present study established for the first time a protocol to obtain and characterize cells derived from pancreas of canine fetuses. Those fetuses do not have a defined breed and were at the final stage of gestation. The protocol aims to provide morphological data to enable future applications of these cells for therapeutic approaches. In cell culture, pancreatic cells showed a fibroblast-like appearance with a mono-layered growth pattern and were not tumorigenic. They exhibited a positive expression for the pluripotent proliferation markers NANOG and PCNA and expressed PDX1, a transcription factor that is important for activation of the insulin gene promoter. In addition, Tyrosine Hydroxylase-positive (TH+) sympathetic nerve fibers were identified. Histologically, the pancreatic epithelium was developed, pancreatic glands in the fetuses were like those in the parenchyma of postconception dogs and pancreatic islets were unevenly distributed and organized in small clusters along the glands close to the vasculature. Staining with dithizone indicated the presence of insulin in the cells. A large number of beta cells were confirmed by immunofluorescence. In conclusion, the canine fetal pancreas cells could be an alternative and adequate source of cell lineages for stem cell therapies for diabetes treatment. Anat Rec, 302:1409-1418, 2019. © 2018 Wiley Periodicals, Inc.

Gene therapy and type 1 diabetes mellitus

BACKGROUND

Type 1 diabetes mellitus (T1DM) is an autoimmune disorder characterized by T cell-mediated self-destruction of insulin-secreting islet β cells. Management of T1DM is challenging and complicated especially with conventional medications. Gene therapy has emerged as one of the potential therapeutic alternatives to treat T1DM. This review primarily focuses on the current status and the future perspectives of gene therapy in the management of T1DM. A vast number of the studies which are reported on gene therapy for the management of T1DM are done in animal models and in preclinical studies. In addition, the safety of such therapies is yet to be established in humans. Currently, there are several gene level interventions that are being investigated, notably, overexpression of genes and proteins needed against T1DM, transplantation of cells that express the genes against T1DM, stem-cells mediated gene therapy, genetic vaccination, immunological precursor cell-mediated gene therapy and vectors.

METHODS

We searched the current literature through searchable online databases, journals and other library sources using relevant keywords and search parameters. Only relevant publications in English, between the years 2000 and 2018, with evidences and proper citations, were considered. The publications were then analyzed and segregated into several subtopics based on common words and content. A total of 126 studies were found suitable for this review.

FINDINGS

Generally, the pros and cons of each of the gene-based therapies have been discussed based on the results collected from the literature. However, there are certain interventions that require further detailed studies to ensure their effectiveness. We have also highlighted the future direction and perspectives in gene therapy, which, researchers could benefit from.

Therapeutic Potential of Adipose Stem Cells

Adipose stem cells (ASCs) have gained attention in the fields of stem cells regenerative medicine due to their multifaceted therapeutic capabilities. Promising preclinical evidence of ASCs has supported the substantial interest in the use of these cells as therapy for human disease. ASCs are an adult stem cell resident in adipose tissue with the potential to differentiation along mesenchymal lineages. They also are known to be recruited to sites of inflammation where they exhibit strong immunomodulatory capabilities to promote wound healing and regeneration. ASCs can be isolated from adipose tissue at a relatively high yield compared to their mesenchymal cell counterparts: bone marrow-derived mesenchymal stem cells (BM-MSCs). Like BM-MSCs, ASCs are easily culture expanded and have a reduced immunogenicity or are perhaps immune privileged, making them attractive options for cellular therapy. Additionally, the heterogeneous cellular product obtained after digestion of adipose tissue, called the stromal vascular fraction (SVF), contains ASCs and several populations of stromal and immune cells. Both the SVF and culture expanded ASCs have the potential to be therapeutic in various diseases. This review will focus on the preclinical and clinical evidence of SVF and ASCs, which make them potential candidates for therapy in regenerative medicine and inflammatory disease processes.

Dicaffeoylquinic Acid-Enriched Fraction of Cichorium glandulosum Seeds Attenuates Experimental Type 1 Diabetes via Multipathway Protection

Chicory has a major geographical presence in Europe and Asia. Cichorium glandulosum Boiss. et Huet, a genus Cichorium, is used for medicinal and food purposes in Asia. In this study, a dicaffeoylquinic acid-enriched fraction of C. glandulosum seeds n-BuOH fraction (CGSB) could ameliorate type 1 diabetes mellitus (T1DM) in streptozotocin (STZ)-induced diabetic mice with continuous administration for 2 weeks. CGSB treatment showed significantly higher plasma insulin levels but lower free fatty acids in adipose tissue and liver. Moreover, CGSB improved pancreatic islet mass. In vitro, different fractions of C. glandulosum seed (CGS) induced the differentiation of 3T3-L1 preadipocytes. The mRNA level for peroxisome proliferator-activated receptor alpha increased in high glucose treatment group in HepG2 cells, while CGSB significantly down-regulated the mRNA expression. The main compound of CGSB, 3,5-dicaffeoylquinic acid, was isolated and identified, which exhibited α-glucosidase inhibitory activity. These findings demonstrated that CGSB attenuated experimental T1DM via multipathway protection.

A Method for Performing Islet Transplantation Using Tissue-Engineered Sheets of Islets and Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are known to have a protective effect on islet cells. Cell sheets developed using tissue engineering help maintain the function of the cells themselves. This study describes a tissue engineering approach using islets with MSC sheets to improve the therapeutic effect of islet transplantation. MSCs were obtained from Fischer 344 rats and engineered into cell sheets using temperature-responsive culture dishes. The islets obtained from Fischer 344 rats were seeded onto MSC sheets, and the islets with MSC sheets were harvested by low-temperature treatment after coculture. The functional activity of the islets with MSC sheets was confirmed by a histological examination, insulin secretion assay, and quantification of the levels of cytokines. The therapeutic effects of the islets with MSC sheets were investigated by transplanting the sheets at subcutaneous sites in severe combined immunodeficiency (SCID) mice with streptozotocin-induced diabetes. Improvement of islet function and viability was shown in situ on the MSC sheet, and the histological examination showed that the MSC sheet maintained adhesion factor on the surface. In the recipient mice, normoglycemia was maintained for at least 84 days after transplantation, and neovascularization was observed. These results demonstrated that islet transplantation in a subcutaneous site would be possible by using the MSC sheet as a scaffold for islets.