Stem cell therapy holds immense promise for treating a wide range of diseases and injuries, offering hope for regenerating damaged tissues. But what if our bodies already held a key to potent, natural repair, a “super-healer” stem cell with unique abilities? Emerging research is spotlighting Human Multilineage-differentiating Stress-Enduring (Muse) cells as a revolutionary player in regenerative medicine.
A recent review article by Mari Dezawa in Frontiers in Bioengineering and Biotechnology highlights just how unique and effective Muse cells are, distinguishing them from other known somatic stem cells.
What Makes Muse Cells So Special? The “Dual Nature” of a Natural Healer
Muse cells are not just any stem cells; they possess a remarkable dual identity that makes them exceptionally effective at tissue repair. As Dezawa (2025) explains, they are both “pluripotent-like and macrophage-like.”
- Pluripotent-like: This means they have the ability to self-renew and differentiate into various cell types found in the body, including ectodermal, endodermal, and mesodermal lineages. This allows them to seamlessly integrate and become the specific cells needed for repair.
- Macrophage-like: Like macrophages, the body’s immune clean-up crew, Muse cells can “phagocytose damaged/apoptotic cells” (Dezawa, 2025). This dual action means they can both clear out unhealthy cells and then replace them with healthy ones.
Found naturally throughout the body – in bone marrow, peripheral blood, and organs, even umbilical cord and amnion – Muse cells are truly “endogenous reparative stem cells” (Dezawa, 2025). Crucially, they are “non-tumorigenic,” meaning they don’t form tumors, a significant safety advantage over some other pluripotent stem cell types.
How Do They Find and Fix Damage? A Precise Healing Mechanism
What truly sets Muse cells apart is their remarkable ability to actively seek out and repair areas of injury through a sophisticated, multi-step mechanism:
- Smart Homing to Damage: Unlike many other stem cells that can get trapped in organs like the lungs when injected, Muse cells exhibit an impressive migratory ability. They “selectively migrate to damaged sites by sensing one of the universal tissue damage signals, sphingosine-1-phosphate (S1P)” (Dezawa, 2025). This means they intelligently navigate to where they’re needed most.
- Clean-up & Direct Replacement: Once at the injury site, Muse cells get to work. They engulf and clear out damaged or dead cells. But they don’t stop there. Instead of just cleaning up, they “differentiate into the same cell type as the phagocytosed cells” (Dezawa, 2025), effectively replacing unhealthy tissue with healthy, functioning cells. This rapid, direct replacement is a cornerstone of their reparative power.
- Immune Privilege: Perhaps one of the most exciting characteristics for clinical application is their unique immune profile. Muse cells possess specific “immunosuppressive and immunotolerant mechanism[s]” (Dezawa, 2025). This is a game-changer, as it means they can be used “without human leukocyte antigen (HLA) matching or immunosuppressant treatment” (Dezawa, 2025), eliminating a major hurdle in cell therapies.
Beyond Other Stem Cells: What Sets Muse Cells Apart?
The review emphasizes that Muse cells are distinctly different from other well-known somatic stem cells, including mesenchymal stem cells (MSCs), very small embryonic-like (VSEL) stem cells, and marrow-isolated adult multi-lineage inducible (MIAMI) cells.
Traditional MSCs, while valuable, often face challenges like poor homing and limited differentiation capabilities. The paper highlights that MSCs can be “trapped in the lung after intravenous injection, preventing them from reaching the damaged tissues, and they disappear from the body within several weeks” (Dezawa, 2025). Muse cells, in contrast, “remain in the homed tissue as part of the tissue component for an extended period due to a specific immunotolerance mechanism” (Dezawa, 2025).
Furthermore, Muse cells maintain their pluripotency in a unique way that avoids the tumorigenic risks associated with embryonic and induced pluripotent stem cells. This is attributed to a specific intracellular mechanism involving the let-7 microRNA, rather than the oncogenic LIN28 (Dezawa, 2025).
Real-World Impact: Promising Clinical Trials
The promise of Muse cells is not just theoretical; it’s being tested and proven in various human clinical trials across a spectrum of challenging conditions:
- Acute Myocardial Infarction (AMI)
- Subacute Ischemic Stroke
- Epidermolysis Bullosa (EB)
- Amyotrophic Lateral Sclerosis (ALS)
- Cervical Spinal Cord Injury
- Neonatal Hypoxic-Ischemic Encephalopathy (HIE)
- COVID-19 Acute Respiratory Distress Syndrome
A common thread through these trials is the safety and therapeutic efficacy demonstrated with simple intravenous injections. Dezawa (2025) states that these trials “involved the intravenous injection of ~1.5 × 10^7 donor Muse cells without human leukocyte antigen (HLA) matching or immunosuppressant treatment, and they demonstrated safety and therapeutic efficacy.”
For instance, in ischemic stroke trials, Muse cell-treated patients showed “statistically meaningful functional recovery” that was “maintained for up to 52 weeks” (Dezawa, 2025). For patients with Epidermolysis Bullosa, Muse cell treatment resulted in “rapid wound healing, slower expansion of the affected area, and sustained deposition of hCOL7 and hCOL17 in the BMZ for more than 6 months without immunosuppressants” (Dezawa, 2025).
The Future of Regenerative Medicine
This unique combination of smart homing, direct repair, and immune tolerance positions Muse cells as a potential game-changer. The fact that Muse cell treatment “does not require gene manipulation, differentiation induction, or surgical intervention” (Dezawa, 2025) simplifies the therapeutic process considerably, making it more accessible and reducing regulatory hurdles.
As research progresses, Muse cells offer a compelling vision of a future where our bodies’ innate healing power can be harnessed more effectively, revolutionizing how we approach tissue repair and disease treatment.
References:
Dezawa, M. (2025). Macrophage- and pluripotent-like reparative Muse cells are unique endogenous stem cells distinct from other somatic stem cells. Frontiers in Bioengineering and Biotechnology, 13:1553382. DOI: 10.3389/fbioe.2025.1553382