Cerebellar Expression of Copper Chaperone for Superoxide,Cytosolic Cu/Zn-Superoxide Dismutase, 4-Hydroxy-2-Nonenal,Acrolein and Heat Shock Protein 32 in Patients with Menkes Kinky Hair Disease: Immunohistochemical Study

Background

To clarify the pathogenesis of cerebellar Purkinje cell death inpatients with Menkes kinky hair disease (MD), a disorder of copper absorption, weinvestigated the morphological and functional abnormalities of residual Purkinje cells inMD patients and the mechanism of cell death.

Methods

Seven MD patients and 39 neurologically normal autopsy cases werestudied. We performed histopathological and quantitative analyses of the Purkinje cells.In addition, we used immunohistochemistry to detect copper-dependent enzymes [cytosolicCu/Zn-superoxide dismutase (SOD1) and copper chaperone for superoxide dismutase (CCS)],oxidative stress markers [4-hydroxy-2-nonenal (HNE) and acrolein] and heat shock protein32 (hsp 32).

Results

The surviving MD Purkinje cells showed abnormal development, such assomatic sprouts and heterotopic location. Due to maldevelopment and degeneration,dendrites showed the cactus and weeping willow patterns. Axonal degeneration led to theformation of torpedoes. Quantitative analysis revealed loss of approximately 50% of thePurkinje cells in MD patients. Almost all of the normal Purkinje cells were positive forimmunostaining by anti-CCS and anti-SOD1 antibodies, with staining of the cell bodies,dendrites and axons. Normal Purkinje cells were not stained by antibodies for HNE,acrolein or hsp 32. In MD patients, the majority of Purkinje cells were positive for CCS,but the positive rate for SOD1 was only about 23%. Approximately 56%, 42% and 40% of thePurkinje cells of MD patients were positive for HNE, acrolein and hsp 32,respectively.

Conclusion

In MD patients, about 50% of the Purkinje cells have been lostdue to maldevelopment and degeneration. In the residual Purkinje cells, CCS expressionseems to be nearly normal as a protective response to decreased SOD1 activity due tocopper deficiency. Because oxidative stress is elevated secondary to decreased SOD1activity, hsp 32 is induced as another protective mechanism.