Advances in Stem Cell Therapy for Type 2 Diabetes Mellitus

Elie Bterrani¹, Gilles Saleh¹, Grace Wehbe², Tarek Wehbe¹*

1. University of Balamand Faculty of Medicine, Lebanon and Notre Dame University Hospital, Lebanon
2. Sabis International Educational System
   Email: [email protected]

OPEN ACCESS

PUBLISHED: 31 December 2024

CITATION: Bterrani, E., Saleh, G., et al., 2024. Advances in Stem Cell Therapy for Type 2 Diabetes Mellitus. Medical Research Archives, online 12(12).
https://doi.org/10.18103/mra.v12.6174

COPYRIGHT: © 2024 European Society of Medicine. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

DOI https://doi.org/10.18103/mra.v12.6174

ISSN 2375-1924

ABSTRACT

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder marked by insulin resistance and impaired insulin secretion, resulting in hyperglycemia and microvascular complications. Conventional treatments, such as lifestyle changes and pharmacotherapy, often fail to provide optimal glycemic control or prevent complications.

Recent advances in stem cell therapy, particularly involving mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs), have shown promise in reducing blood glucose levels, improving glycated hemoglobin (HbA1c), and addressing microvascular and macrovascular complications without promising a cure for this chronic illness.

Many biotechnological advances have set up T2DM among its targeted conditions. To mention a few, 3D bioprinting and gene therapy are being exploited to enhance stem cell applications.

Though a cure for diabetes remains out of sight, significant progress has been made through these novel approaches. Early clinical trials demonstrate improved glycemic control, insulin independence, and enhanced beta-cell survival all leading a path to control the devastations of T2DM complications.

Advanced stem cell therapies, including the differentiation or reprogramming of embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), MSCs, and marrow-derived stem cells (MDSCs) into beta islet cells, offer other innovative avenues.

In addition to reviewing the recent advances in stem cell therapies in this field, we explore the impact of stem cell differentiation on diabetic complications like nephropathy, neuropathy, retinopathy, and cardiovascular diseases, and the challenges of scalability, safety, and regulatory hurdles. The role of gene editing with CRISPR-Cas9 and the potential of 3D bioprinting, the mechanisms implicated such as direct differentiation, immune modulation, tissue repair, and paracrine effects are also examined.

Keywords: Type 2 diabetes Mellitus, Mesenchymal Stem Cells, Hematopoietic Stem cells, Bioprinting, Gene therapy.

1. Introduction

The global prevalence of T2DM is on the rise, affecting over 463 million people worldwide¹. The major damage of chronic hyperglycemia is its association with long-term complications to various organs including retinopathy, nephropathy, and neuropathy, as well as cardiovascular disease with underlying micro and macrovascular destructions. The pathobiology of T2DM involves primary insulin resistance and ultimately loss of islet β-cell insulin production²–⁴.

Despite advancements in pharmacological treatments, a significant proportion of patients do not achieve adequate glycemic control, and many remain at risk for serious health complications. Consequently, there is a pressing need for innovative therapeutic approaches that can address both the symptoms and underlying causes of T2DM⁵–⁶.

Stem cell therapy has promised cures for many diseases including T2DM by replacing damaged cells, relieving the atrocities of autoimmunity and replenishing the injured beta cells and endothelium of the affected blood vessels. Stem cells emerged as a potential alternative for T2DM, aiming not only to restore normal glucose levels but also to reverse the complications associated with the disease⁷–¹⁰.

The next generation of challenges evolve around turning the stem cells into adjustable, glucose sensing cells that turn on insulin production on demand. In order to avoid using immunosuppressors and deal with their major side effects, it is important to employ stem cell carrying auto-antigens of the person treated or to use stealthy cells like mesenchymal stem cells.

Reprogrammed cells of self-origin may offer this opportunity but their use also requires overcoming several difficulties. Those cells have to be reproducible in sufficient numbers and produce a metered dose of insulin to normalize glucose.

The difficulty in dealing with T2DM emanates from the fact that this disease is not only due to beta cell malfunction but it also has several other facets including autoimmune, insulin resistance, microvascular and inflammatory aspects. The mesenchymal stem cells, being excellent immune modulators, are major players in fixing a number of these pathobiologic defects leading to the diabetic pathology¹⁰.

2. Stem cell therapy overview

Stem cells possess unique properties, including the ability to differentiate into various cell types and self-renewal. Mesenchymal stem cells (MSCs), derived from various tissues such as bone marrow, adipose tissue, and umbilical cords, have shown promise in T2DM therapy by immunomodulatory effects, ability to secrete anti-inflammatory cytokines, and potential to regenerate damaged tissues¹¹–¹³.

In contrast, hematopoietic stem cells (HSCs), primarily derived from bone marrow and peripheral blood, are crucial in hematopoiesis but have also been investigated for their regenerative capabilities in the context of diabetes. It has been demonstrated that stem cells of various sources may promote insulin sensitivity, enhance pancreatic β-cell function, reduce inflammation, and improve endothelial function, all of which contribute to better glycemic control and reduction of T2DM complications¹⁴–¹⁶.

3. Types of stem cells used in therapy

MESENCHYMAL STEM CELLS (MSCs):
MSCs have garnered attention for their regenerative properties and ability to modulate immune responses. They can differentiate into various cell types, including adipocytes, chondrocytes, and osteoblasts, and secrete growth factors that facilitate tissue repair. In T2DM, MSCs can enhance insulin sensitivity and support the regeneration of pancreatic β-cells, thereby improving insulin secretion. In addition to their regenerative potential those cells have multiple effects on different arms of the immune system. Studies have demonstrated that MSCs can reduce systemic inflammation and promote vascular health, which are critical in managing diabetes-related complications. The source of MSCs, whether from bone marrow, adipose tissue, or umbilical cord, may influence their therapeutic efficacy and safety profile, making them a versatile option for clinical applications¹⁶–²⁰.

HEMATOPOIETIC STEM CELLS (HSCs):
HSCs, while traditionally associated with blood formation, have shown potential in regenerative medicine for their ability to differentiate into various blood cell types and support tissue repair. In the context of T2DM, HSCs can contribute to the restoration of normal immune function, thereby addressing inflammation that exacerbates insulin resistance. Additionally, HSCs can influence the microenvironment of pancreatic islets, potentially improving β-cell function and survival. Research indicates that HSC transplantation may lead to better metabolic control and a decrease in diabetes-related complications. However, the mechanisms through which HSCs exert their beneficial effects in T2DM require further investigation²¹–²³.

4. Recent clinical trials and comparative studies

Recent clinical trials have investigated the efficacy of MSCs and HSCs in managing T2DM, revealing promising outcomes. The following table provides a comparative overview of these studies:

Table 1: Recently published studies on stem cell use

These studies demonstrate the potential of stem cells to significantly improve glycemic control, as indicated by reductions in blood glucose and HbA1c levels. Notably, the combined use of MSCs and HSCs appears to offer enhanced benefits, addressing both glycemic control and complication management²⁴–²⁸.

5. Effects of stem cells on blood glucose and HbA1c levels

Multiple studies have confirmed that MSC therapy leads to significant reductions in fasting blood glucose levels and HbA1c. For instance, Wang et al. reported a 30% reduction in blood glucose among patients receiving MSCs, alongside notable decrease in HbA1c levels. This effect is attributed to improved insulin sensitivity and enhanced β-cell function, potentially driven by the anti-inflammatory cytokines secreted by MSCs.

HSCs have also demonstrated efficacy, albeit with varying results compared to MSCs, showing a 25% reduction in blood glucose, highlighting the potential of HSCs in managing T2DM. The effectiveness of these therapies may vary based on the source of stem cells and the method of administration. Additionally, the timing and frequency of treatment could play critical roles in achieving optimal outcomes²⁹–³¹.

6. Impact on micro and macrovascular complications

Stem cell therapy has shown promise in alleviating both microvascular and macrovascular complications associated with T2DM.

MICROVASCULAR COMPLICATIONS:
Studies have indicated that MSC treatment can lead to

improvements in diabetic nephropathy and retinopathy. For instance, Lee et al. (2023) demonstrated significant improvements in renal function among patients treated with MSCs, correlating with reduced proteinuria and enhanced glomerular filtration rates. The ability of MSCs to secrete growth factors and cytokines may contribute to the repair of damaged endothelial cells and the improvement of microvascular circulation³²–³³.

MACROVASCULAR COMPLICATIONS: The effects of stem cells on cardiovascular health are also noteworthy. Research by Kim et al. (2020) suggested that MSC therapy may reduce the incidence of cardiovascular events in T2DM patients, likely through improved endothelial function and reduced arterial stiffness. The anti-inflammatory properties of stem cells play a crucial role in mitigating atherosclerosis and enhancing overall cardiovascular health³⁴–³⁷.

7. Advances in stem cell technologies

Recent technological advancements have further enhanced the applicability of stem cell therapies in T2DM.

3D BIOPRINTING: This innovative technology allows for the creation of complex tissue structures that can replicate the functionality of pancreatic β-cells. Bioprinted tissues have shown potential in preclinical studies, providing a platform for testing stem cell therapies in a controlled environment. This method can potentially yield personalized tissues that closely match patient-specific conditions, improving the success rates of transplantation.

GENE THERAPY: The integration of gene therapy with stem cell treatment represents a novel approach to enhance the efficacy of interventions. Techniques such as CRISPR/Cas9 have been explored to modify stem cells to express insulin or other therapeutic agents, potentially offering long-term solutions for glycemic control. By correcting genetic defects or enhancing the regenerative capacity of stem cells, gene therapy may significantly improve patient outcomes and reduce the need for lifelong pharmacotherapy³⁸–⁴².

8. Challenges and future directions

Despite the promising results, several challenges remain for stem cell therapy for T2DM. Issues related to the sourcing of stem cells, ethical considerations, and the variability of patient responses pose significant hurdles. The cost of stem cell therapies and the need for specialized facilities can also limit accessibility for many patients.

Future research should focus on standardizing protocols, understanding the long-term effects of stem cell therapies, and exploring the combination of these therapies with traditional pharmacological treatments. Additionally, larger-scale clinical trials are essential to validate the findings of smaller studies and to assess the safety and efficacy of stem cell therapies in diverse populations⁴³.

9. Conclusion

Many completed and ongoing clinical trials have shown tremendous potentials that need further clarifications and unlocking. The controversies remain numerous as well and many debates remain unresolved about the potentials, the ethics, the promises and conditions to use these nearly magic tools.

The ethical dilemmas about the use of human embryos not an easy obstacle to work around. Induced Pluripotent stem cells (iPSCs) may help avoid using embryonic stem cells but also are hurled with major technical difficulties. The unlimited differentiation potential of iPSCs may correlate with malignant transformation as a major safety issue⁴⁴.

Mesenchymal stem cells (MSCs) may be the easiest to use and that explains their frequent use in most published clinical data. We also have a better idea about these cells and what they can do such as the benefit of autoimmune regulation and ease of administration with minor or no hypersensitivity reactions. This review, we hope, provided a good round of information on the field.

Stem cell therapy presents a novel and promising avenue for managing T2DM, with significant

potential to improve glycemic control and reduce complications. As research advances and technologies such as 3D bioprinting and gene therapy evolve, the future of T2DM treatment may be transformed through innovative applications of stem cell science combined with other modalities such as gene therapy and bioprinting to replace damaged tissue.

By tackling the underlying mechanisms of the disease and its complications, stem cell therapy may offer a more comprehensive and effective approach to T2DM management as more targeted, personalized approaches possibly guided by artificial superintelligence are being employed⁴⁵. The road is long and the challenges many but there is no doubt that the tremendous potential of the stem cells is being unlocked as we move into the future of medicine where newer tools are needed and use of every resource is of ultimate importance.

Conflict of Interest:

None.

Funding Statement:

None.

Acknowledgements:

None.

References