Effect of Intranasally Administered Stem Cell-Derived Exosomes on Rat's Olfactory Bulb Histological Structure After...

Area of Science:

• Neuroscience
• Toxicology
• Regenerative Medicine

Background:

• Lead is a ubiquitous heavy metal with known toxic effects.
• Lead-oxide nanoparticles (PbO-NPs) pose a potential risk due to their small size and widespread use.
• The olfactory bulb (OB) is a critical brain region for sensory processing, susceptible to environmental toxins.

Purpose of the Study:

• To investigate the neurotoxic effects of intranasal lead-oxide nanoparticles (PbO-NPs) on the rat olfactory bulb (OB).
• To evaluate the therapeutic efficacy of stem cell-derived exosomes (EXOs) in mitigating PbO-NP-induced OB damage.

Main Methods:

• Male rats were exposed intranasally to PbO-NPs for 3 weeks.
• Treatment groups received either PbO-NPs alone, recovery period, or PbO-NPs followed by EXOs.
• Olfactory function was assessed behaviorally, and OBs were analyzed histologically and immunohistochemically for structural and molecular changes.

Main Results:

• PbO-NP exposure led to significant olfactory dysfunction, reduced OB layer thickness, and decreased glomeruli diameter.
• Histological analysis revealed damage to mitral cells and reduced synaptophysin (SYP) expression.
• PbO-NP exposure increased markers of neuroinflammation, including Iba-1 and GFAP.
• Exosome treatment (EXO) significantly reversed these behavioral and histological deficits, restoring OB structure and function.

Conclusions:

• Intranasal administration of PbO-NPs induces significant neurotoxicity in the rat olfactory bulb.
• Stem cell-derived exosomes demonstrate a notable therapeutic effect, ameliorating PbO-NP-induced olfactory bulb damage and dysfunction.
• EXOs represent a promising therapeutic strategy for neurotoxicity induced by heavy metal nanoparticles.