Impairment of the cell destruction process in horses, triggered by bovine papillomaviruses, could be the driver of sarcoid development, researchers believe.
Manuela Martano and her fellow researchers, writing in the journal Animals, said it is well known that bovine papillomaviruses can interfere with the survival and proliferation of cells by regulating autophagy.
Autophagy is a normal physiological process that deals with the turnover of cells in the body, including the reuse of some cellular material.
Researchers from the University of Naples study set out to evaluate the expression level of some of the main proteins involved in the autophagic pathway, such as Beclin 1, LC3 and P62, in equine sarcoids and normal skin.
Dysfunctions of these autophagy-related proteins have been implicated in many disorders, they said.
They tested 35 sarcoid samples and five healthy skin samples from horses. The sarcoids all tested positive for either bovine papillomavirus 1 or bovine papillomavirus 2.
The results of their immunohistochemical and biochemical analysis of equine sarcoids suggested an alteration of the autophagic process which could lead to a predominance of a particular population of fibroblast.
Fibroblasts are the most common type of cell found in connective tissue. They secrete collagen proteins that are crucial in maintaining a structural framework in many tissues.
Their results, they said, point to the activation of the initial phase of autophagy in equine sarcoids, and its impairment during the following steps.
“The impairment of autophagy could lead to a selection of a quiescent (temporarily inactive) population of fibroblasts,” they said.
“Those fibroblasts could survive longer in a hypoxic microenvironment and produce more and/or altered collagen, giving an origin to the equine sarcoid.”
The study team noted that, despite many treatment options for equine sarcoids, not all are totally effective. There are frequent recurrences.
The study, they said, paves the way for additional laboratory work which may contribute to a better understanding of autophagic processes in equine sarcoids and the possible role of bovine papillomavirus 1 and 2 in its regulation.
It may also give rise to new ideas for possible therapeutic strategies, they said.
Martano, M.; Altamura, G.; Power, K.; Liguori, P.; Restucci, B.; Borzacchiello, G.; Maiolino, P. Beclin 1, LC3 and P62 Expression in Equine Sarcoids. Animals 2022, 12, 20. https://doi.org/10.3390/ani12010020