Lead-induced changes of cytoskeletal protein is involved in the pathological basis in mice brain

Area of Science:

• Neuroscience
• Toxicology
• Geochemistry

Background:

• Lead poisoning is a geochemical disease with known liver, kidney, and carcinogenic effects.
• Lead can cross the blood-brain barrier, impairing cognitive functions like learning and memory and damaging brain structures.

Purpose of the Study:

• To investigate the neurotoxic mechanisms of lead (Pb2+) exposure.
• To examine the dose-dependent effects of lead on mouse brain cells and function.

Main Methods:

• Exposure of 4-week-old Kunming mice to varying Pb2+ concentrations (0, 2.4, 4.8, 9.6 mM) for 9 days.
• Analysis of pathological and ultrastructural brain cell changes, including mitochondrial, chromatin, and nuclear damage.
• Quantification of blood lead levels using atomic absorption spectroscopy.
• Determination of lead distribution in nerve cells via transmission electron microscopy with energy dispersive spectroscopy.
• Assessment of microtubule-associated protein 2 (MAP2) mRNA and protein expression using real-time PCR and Western blotting.

Main Results:

• Pathological and ultrastructural damage to mitochondria, chromatin, and nuclei in brain cells of treated mice.
• Increased blood lead concentrations correlating with higher lead acetate doses.
• Presence of lead within nerve cell nucleopores, chromatin, and nuclear membranes, increasing with dose.
• Dose-dependent reduction in both MAP2 mRNA and protein expression in the mouse brain.

Conclusions:

• Acute lead poisoning induces significant, dose-dependent toxic effects on mouse brain function.
• Lead accumulation in nerve cells, particularly within the nucleus, is associated with observed neurotoxicity.
• Reduced MAP2 expression indicates potential disruption of neuronal structure and function following lead exposure.