Regional expression of tyrosinase in central catecholaminergic systems of colored mice

Abstract

A relationship between coat color and behavioral characteristics has been reported for numerous species. We previously indicated that particular behavioral traits contributing to the genotype at the agouti locus manifest only when possessing a wild-type allele at the albino (i.e., tyrosinase: Tyr) locus. The present study was performed to investigate tyrosinase expression with marked activity in central nervous systems. The whole brain of male B10 and B10-c mice, a B10 congenic strain of the albino locus from BALB/c at 8 to 9 weeks of age, was removed and we obtained several regions of brain, especially catecholaminergic. Comparatively large amounts of Tyr mRNA and its translation products of approximately 68 kDa were found in the regions obtained, and definitely possessed the enzyme activity for the oxidation of L-tyrosine. The present results indicate the possibility that the amount of catecholamines produced in albino mice is higher than that of colored mice due to the deficit in tyrosinase heritably.

A Preclinical Model for Parkinson’s Disease Based on Transcriptional Gene Activation via KEAP1/NRF2 to Develop New Antioxidant Therapies

“…In the case of overexpression of tyrosinase in astrocytes, this enzyme can also oxidize dopamine, since this type of glial cell can take up dopamine released during neurotransmission; (iii) the triggering agent of the neurodegenerative process in this preclinical model is not a neurotoxin that can be the target of new pharmacological drugs attempting to stop the degenerative process, but rather it is tyrosinase, which is not expressed in the human substantia nigra. However, there are some reports that suggest its expression in this tissue [ 60 ], but if it were true that tyrosinase is normally expressed in neuromelanin-containing dopaminergic neurons, the presence of the pigment would be observed from an early age in children. Several studies have indeed shown that tyrosinase is not present in the human substantia nigra, even using highly specific and sensitive mass spectroscopy [ 61 , 62 ] (Zucca et al, 2018; Tribl et al, 2007).…”

Tyrosinase deficiency impairs social novelty preference in mice

“…Although the expression and enzymatic activity of tyrosinase have been detected in differentiated melanocytes distributed in the skin and retinal pigment epithelium, we and other researchers also reported tyrosinase enzymatic activity in the central nervous system, particularly in the midbrain substantia nigra of mammals [6–10]. Although the functional role of tyrosinase in the brain remains largely unknown, we have previously reported that tyrosinase activity prevented oxidative stress-induced protein damage in the mouse substantia nigra [11].…”