Huntingtons disease (HD) is a neurodegenerative disorder that is caused by an expansion of a polyglutamine (polyQ) domain in the protein of huntingtin (htt). PolyQ expansion above 35–40 results in disease associated with htt aggregation into inclusion bodies. The recent studies have shown that the illness arises not only in neurons, but also in non-neuronal cells. Purpose of this study was to investigate the expression of selected HD markers (on htt and their aggregates, ferritin and ubiquitin) in corneas of minipig transgenic for the human mutated huntingtin and compare them with corneas of wild type (WT) minipig.Methods
In this study we used WT minipigs and minipigs transgenic for N-terminal part of the human mutated huntingtin (both F2 generation, age 24 months). HD markers were examined on cryostat sections immunohistochemically by using the following primary antibodies: anti-polyglutamines, anti-polyglutamine-expansion diseases marker, MW8 marker, anti-ferritin and anti-ubiguitin.Results
Immunohistochemical examination on huntingtin demonstrated the increased expression of this protein in corneal epithelium and keratocytes of transgenic minipig in comparison with wild type cornea. The expression of ferritin detected in epithelial cells was very low in both studied corneas without significant difference between them. No nuclear inclusions or ubiquitous proteins were found in the cornea of transgenic minipig.Conclusion
This study showed that preclinical (silent) stages of HD are characterized by an elevated level of mutagenic huntingtin without formation of nuclear inclusions and ubiquitination of proteins. Supported by CHDI Foundation (A-5378 and A-5379), TA01011466, CZ.1.05./2.1.00/03.0124 and RVO: 67985904.