CONICET | Buscador de Institutos y Recursos Humanos

Purpose The primary cause for neuronal death in sporadic amyotrophic lateral sclerosis (sALS) remains unclear. There is evidence for increased oxygen radical damage in brain tissue of patients with sALS. Abnormal mitochondria in motor neurons in human cases of sALS were reported previously; also, mitochondrial abnormalities were found in liver and peripheral blood lymphocytes from individuals with sALS. Our purpose was to determine whether skin´s mitochondria of sALS patients show abnormalities. Method We performed skin biopsies in 5 sALS patients and 3 healthy controls. Biopsies were observed and photographed with electron microscope. Mitochondrial features were analyzed using a computerized image analyzer (OPTIMAS 6.02). Results We observed 112 mitochondria of sALS patients and 81 of controls. The average mitochondrial major axis length was 0.36 (± 0.15) microns in patients and 0.44 (± 0.17) microns (p <0.001) in controls. The average mitochondrial area was 0.08 (± 0.06) microns2 in patients and 0.11 (± 0.08) microns2 (p <0.001) in controls. The average mitochondrial perimeter was 1.11 (± 0.45) microns in patients and 1.35 (± 0.5) microns (p <0.0001) in controls. We found 5 (4.46%) mitochondria with the external membrane broken in sALS patients, none in controls. Conclusions Mitochondria of the skin of this group of sALS patients were smaller than those found in healthy controls. While it is possible that oxidative stress also involves the skin of patients, only motor neurons are clinically affected, due to their own features