Bone marrow stromal cells increase oligodendrogenesis after stroke

Area of Science:

• Neuroscience
• Regenerative Medicine
• Cell Biology

Background:

• Oligodendrocytes are vulnerable to ischemic injury, impacting brain function.
• The Sonic hedgehog (Shh) pathway, with Gli1 as its effector, plays a key role in generating new oligodendrocytes.
• Bone marrow stromal cells (BMSCs) show promise in improving functional recovery after stroke.

Purpose of the Study:

• To investigate the impact of BMSC treatment on oligodendrogenesis and Shh/Gli1 pathway activation following stroke in a rat model.
• To determine if BMSCs stimulate the production of oligodendrocytes and myelin in the affected brain regions.
• To elucidate the role of the Shh/Gli1 pathway in mediating the effects of BMSCs post-stroke.

Main Methods:

• Middle cerebral artery occlusion (MCAo) model in rats to induce stroke.
• BMSC transplantation (3 x 10(6) cells) initiated 1 day post-MCAo.
• Immunohistochemistry and gene expression analysis (mRNA and protein) of oligodendrocytes, myelin, Shh, and Gli1 at 2 and 14 days post-MCAo.
• In vitro study using N20.1 oligodendrocyte precursor cells treated with BMSCs and a Shh inhibitor (cyclopamine).

Main Results:

• BMSC treatment significantly increased the number of oligodendrocytes (O4+), myelin basic protein (MBP) expression, and oligodendrocyte progenitor cells (BrdU+, NG2+, BrdU+-NG2+) in the stroke-affected brain.
• BMSC administration upregulated both mRNA and protein expression of Shh and Gli1 in the ipsilateral hemisphere post-MCAo.
• In vitro, BMSCs enhanced N20.1 cell proliferation and Gli1 expression, effects blocked by cyclopamine, confirming Shh pathway involvement.

Conclusions:

• BMSC treatment effectively stimulates oligodendrogenesis and remyelination after ischemic stroke in rats.
• The therapeutic benefits of BMSCs in stroke appear to be mediated, at least in part, by the activation of the Shh/Gli1 signaling pathway.
• Targeting the Shh/Gli1 pathway with BMSCs represents a potential therapeutic strategy for stroke recovery.