There are currently over 3,000 clinical studies in progress investigating the use of adult stem cells for treating degenerative diseases, healing bodily tissues, and combating aging [1]. Bone marrow-derived mesenchymal stem cells (MSCs) have demonstrated exceptionally promising therapeutic results in treating neurological diseases, including Parkinson’s disease, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), spinal cord injury, through promoting neural regeneration. Clinical trials studying bone marrow-derived MSCs in other diseases associated with aging, including macular degeneration and osteoarthritis, have also demonstrated how stem cells can be used to fight the effects of aging.

Parkinson’s disease

Parkinson’s disease is a neurodegenerative disease characterized by a rapid loss of midbrain dopaminergic neurons that leads to deterioration of motor activities. Approximately 10 million people are affected by Parkinson's disease worldwide [2].

Bone marrow-derived MSCs have demonstrated exceptionally promising therapeutic results in treating Parkinson’s disease through promoting neural regeneration [3]. Multiple clinical studies in humans have been conducted in the past decade to study the potential for bone marrow-derived autologous MSCs to reduce Parkinson’s disease progression, and more clinical trials are planned to definitively demonstrate the efficacy of this approach [4, 5].

ALS

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that leads to degeneration of the motor neurons, causing paralysis and muscle weakness. The majority of ALS patients are diagnosed between the ages of 40 and 70, and 90% of people diagnosed with ALS have no family history of ALS or genetic mutation linked to ALS [6]. There is currently no cure for ALS, and disease progression typically leads to death in two to four years [7].

Multiple phase 1 and phase 2 clinical studies in human ALS patients have demonstrated that injections of autologous bone marrow-derived MSCs can slow down progression of the disease [3, 7, 8]. A phase 3 randomized, controlled clinical trial is currently underway for autologous bone marrow derived MSCs, and is expected to complete in 2026 [9].

MS

Multiple sclerosis (MS) is a debilitating autoimmune disease of the central nervous system. Researchers are exploring whether stem cell therapy may halt disease progression by counteracting the inflammatory process that causes the demyelination and axonal damage. In addition, studies are investigating the possibility of reversing neural damage through stem cells promoting regrowth of neural tissues [1].

A phase 1/2 randomized controlled clinical trial demonstrated potential efficacy of autologous bone marrow-derived MSCs as a treatment for primary or secondary progressive MS. Patients receiving MSCs in the study exhibited improvements in disease activity, relapse rate, mobility tests, cognitive tests, and MRI activity [10].

Spinal cord injury

Approximately 40 to 80 million people suffer from spinal cord injuries every year, which results in permanent neurological damage [11].

Studies underway are exploring the use of bone marrow derived mesenchymal stem cells to repair spinal cord injuries through promoting growth of axons and neural connections after preclinical studies demonstrated the promise of this therapy [1]. Multiple clinical trials of bone marrow derived MSCs in humans with spinal cord injuries have demonstrated that the treatment leads to improvements in functional and motor abilities [11].

Furthermore, a stem-cell treatment has already been approved in Japan for treating spinal cord injuries based on a human clinical trial that demonstrated that injecting stem cells from a spinal cord patients’ bone marrow led to improvements in the patients’ sensation and mobility [1, 12].

Macular degeneration

Researchers are exploring stem cell-based therapies that may improve the eyesight of patients suffering from macular degeneration. In a recently published human study conducted in Japan, autologous stem cells induced to differentiate into pigment epithelial cells of the retina demonstrated the feasibility of this treatment for macular degeneration [13].

Osteoarthritis

Osteoarthritis is a chronic joint disease that affects approximately 250 million people and is a leading cause of disability in older adults. Osteoarthritis is typically diagnosed in midlife after a gradual progression of symptoms, such as chronic pain, stiffness, reduced mobility, and joint tenderness [14].

Bone marrow-derived MSCs have shown great promise in treating osteoarthritis due to their ability to stimulate cartilage formation, vascularization, anti-inflammation, and immunoregulation. Multiple clinical trials have demonstrated the potential efficacy of MSCs derived from bone marrow in the treatment of osteoarthritis [14]. Recently, a phase 1/2 randomized controlled clinical trial demonstrated that bone marrow-derived MSCs combined with hyaluronic acid results in a clinical and functional improvement of knee osteoarthritis [15].