Mesenchymal stem cells (MSCs) are a type of adult stem cell known for their ability to regenerate, modulate the immune system, reduce inflammation, and communicate through signaling. They are pivotal in the body's capacity to produce specialised cells for various tissues and organs. MSCs possess a remarkable ability to replicate and transform into multiple cell types found in specific tissues or organs.

These versatile cells can be obtained from several sources, including adipose tissue (fat), bone marrow, the umbilical cord, blood, liver, dental pulp, and skin. This discussion will specifically highlight mesenchymal stem cells derived from adipose tissue (ADSCs), bone marrow (BMSCs), and umbilical cord tissue (UC-MSCs), showcasing their unique properties and potential applications in regenerative medicine.

Mesenchymal stem cells (MSCs) hold significant potential in treating a range of diseases, thanks to their abilities to regenerate, differentiate, reduce inflammation, and modulate the immune system. Research conducted both in vitro (within a lab environment) and in vivo (within a living organism) has advanced our comprehension of how MSC therapies work, their safety, and their effectiveness in clinical settings.

A notable study in 2018 by Crigna and colleagues highlights the application and impact of MSC therapy in the medical field.

Adipose tissue-derived mesenchymal stem cells (ADSCs) 

Adipose tissue-derived mesenchymal stem cells (ADSCs) are harvested from subcutaneous fat and can be collected in abundant quantities with high vitality through liposuction.

ADSCs tend to exhibit higher viability when sourced from younger donors, which may pose challenges for older patients undergoing autologous treatments (where the patient's own cells are used), as aged cells might not thrive as well long-term. Despite this, ADSCs from younger individuals show increased proliferation rates (ability to survive post-transplant) compared to those from older donors. Nonetheless, their capacity to differentiate, even with age, remains consistent, offering benefits over bone marrow-derived mesenchymal stem cells (BM-MSCs).

ADSCs are particularly noted for their ability to transform into cells of mesodermal origin, their low immunogenicity, and immunomodulatory properties. A minimal percentage display the HLA-DR protein, contributing to their immunosuppressive capabilities and making them favourable for use in allogeneic transplants and treatments for stubborn immune disorders.

ADSCs are recognized for their broad therapeutic potential, including orthopaedic applications. They are effectively used in treating conditions such as spinal cord injuries, arthritis, localised joint inflammation, knee pain, and various musculoskeletal disorders.

Nonetheless, implementing ADSCs clinically faces hurdles like age-related proliferative limitations, restricted differentiation potential, and the need for standardised protocols.

This perspective is further supported by research from Mazini et al., indicating ongoing exploration and refinement in the field.

 Bone marrow-derived mesenchymal stem cells (BM-MSCs) 

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent adult stem cells renowned for their roles in treating various diseases through their capabilities for self-renewal, differentiation, and immune system modulation.

Research both in the lab and in living organisms has backed the understanding of the mechanisms, safety, and effectiveness of BM-MSC therapy in medical applications. Although the pace of phase I/II clinical trials is increasing, challenges such as limited participant numbers, regulatory hurdles, and the need for standardised procedures for preparation, transportation, and administration of BM-MSCs contribute to variations in treatment outcomes.

BM-MSCs are a scarce component of the stromal cell population, making up only 0.002%, with isolation success depending on the patient's health status and the amount of material collected.

Like ADSCs, the quantity and quality of bone marrow stem cells decrease with age. Younger donors typically yield more viable BM-MSCs for allogeneic treatments, highlighting challenges for older patients in autologous procedures, where the diminished fitness of aged cells may impact their long-term effectiveness in the recipient. This issue has been documented by Chu et al. in a 2020 study.

Umbilical cord tissue-derived mesenchymal stem cells (UC-MSCs) 

Umbilical cord tissue-derived mesenchymal stem cells (UC-MSCs) are harvested from various parts of the umbilical cord, such as Wharton’s Jelly, the cord lining, and the peri-vascular area. This source is particularly valuable because it is non-invasive and utilises tissue that is typically discarded, offering a rich supply of mesenchymal stromal cells. UC-MSCs stand out for their high differentiation capability and are noted for their superior proliferation rate compared to adipose and bone marrow-derived stem cells.

Like their counterparts from adipose tissue and bone marrow, UC-MSCs release growth factors, cytokines, and chemokines that enhance cellular repair mechanisms, contributing to their anti-inflammatory and immunomodulatory effects.

The collection of UC-MSCs is non-invasive, involving no patient extraction but rather the use of ethically donated umbilical cord material. These cells demonstrate a higher proliferative potential than both BMSCs and ADSCs, making them more efficient in vitro for producing large numbers of cells.

Research indicates that genes associated with cell proliferation, the PI3K-NFkB signalling pathway, and neurogenesis are more active in UC-MSCs compared to BM-MSCs, showcasing their enhanced regenerative capabilities.

In summary, mesenchymal stem cells (MSCs) from adipose tissue, bone marrow, and umbilical cord tissue are pivotal in regenerative medicine, each with distinct advantages. ADSCs are easily accessible and ideal for various treatments, BM-MSCs offer strong self-renewal and differentiation despite collection challenges, and UC-MSCs stand out for their non-invasive procurement and superior regenerative properties. These cell types collectively highlight the potential of stem cell therapy to advance medical treatments and improve patient outcomes, underscoring the importance of ongoing research and clinical trials in harnessing their full therapeutic capabilities.

Reference: 

1.  Mazini, L., Rochette, L., Amine, M., & Malka, G. (2019, May 22). Regenerative Capacity of Adipose-Derived Stem Cells (ADSCs), Comparison with Mesenchymal Stem Cells (MSCs). International journal of molecular sciences. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566837/.
2.  Chu, D.-T., Phuong, T. N. T., Tien, N. L. B., Tran, D. K., Thanh, V. V., Quang, T. L., … Kushekhar, K. (2020, January 21). An Update on the Progress of Isolation, Culture, Storage, and Clinical Application of Human Bone Marrow Mesenchymal Stem/Stromal Cells. International journal of molecular sciences. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7037097/.
3. Jin, H. J., Bae, Y. K., Kim, M., Kwon, S.-J., Jeon, H. B., Choi, S. J., Kim, S. W., Yang, Y. S., Oh, W., & Chang, J. W. (2013, September 3). Comparative analysis of human mesenchymal stem cells from bone marrow, adipose tissue, and umbilical cord blood as sources of cell therapy. International journal of molecular sciences. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3794764/.
4. Walker, J. T., Keating, A., & Davies, J. E. (2020, May 28). Stem Cells: Umbilical Cord/Wharton’s Jelly Derived. Cell Engineering and Regeneration. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7992171/.
5. Arutyunyan, I., Elchaninov, A., Makarov, A., & Fatkhudinov, T. (2016). Umbilical Cord as Prospective Source for Mesenchymal Stem Cell-Based Therapy. Stem cells international. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5019943/.