Distribution of hepatic stellate cells and their role in the development of parasitic fibrosis and liver cirrhosis in domestic animals

Abstract

Increasing of the extracellular matrix in rats, as well as in humans, occurs as a consequence of hepatic stellate cells (HSCs) activity. The objective of this work was to investigation the role of these cells in the development of fibrosis and liver cirrhosis which occurs as a consequence of infection of sheep and goats with large (Fasciola hepatica) and small (Dicrocoelium dendriticum) fluke. Liver samples taken from 12 cattle and 10 sheep infected under natural conditions with large and small fluke were fixed in formalin and embedded in paraffin. Paraffin clips were stained with hematoxylin- eosin and masson trichrome method, and immunohistochemical method for α-smooth muscle actin (α-SMA). All tested samples were divided into three groups according to histological criteria: livers of infected animals with the first degree of fibrosis, livers of infected animals with the second degree of fibrosis, and livers of infected animals with cirrhosis. Distribution of HSCs depended on the degree of liver fibrosis. Immunohistochemically reactive HSCs were predominantly placed in perisinusoidal space. In liver samples with cirrhosis, HSCs were placed on the periphery of pseudolobulus. Cells of a different shape and size were positive to α-SMA. HSCs play an important role in synthesis of components of extracellular matrix during the development of parasitic fibrosis and liver cirrhosis in domestic animals.

Povećanje ekstracelularnog matriksa kod pacova, kao i kod ljudi, nastaje kao posledica aktivacije zvezdastih ćelija jetre (HSCs). Cilj ovog rada je izučavanje uloge ovih ćelija u razvoju fibroze i ciroze jetre koje nastaju kao posledice infekcija ovaca i goveda velikim (Fasciola hepatica) i malim (Dicrocoelium dendriticum) metiljem. Uzorci jetri 12 goveda i 10 ovaca koje su u prirodinim uslovima inficirane velikim i malim metiljem su fiksirani u formalinu i uklopljeni u parafin. Parafinski isečci su bojeni hematoksilin-eozinom i Mason-trihromnom metodom, kao i imunohistohemijskom metodom za α-glatko-mišićni aktin (α-SMA). Svi ispitani uzorci su prema histološkim kriterijumima podeljeni u tri grupe: jetre inficiranih životinja sa I stepenom fibroze, jetre inficiranih životinja sa II stepenom fibroze i jetre inficiranih životinja sa cirozom. Distribucija HSCs je zavisila od stepena fibroze jetre. Imunohistohemijski reaktivne HSCs su bile predominantno smeštene u perisinusoidnim prostorima. U uzorcima jetre sa cirozom HSCs su bile smeštene na periferiji pseudolobulusa. Ćelije različitog oblika i veličine su bile pozitivne na α-SMA. HSCs igraju važnu ulogu u sintezi komponenti ekstracelularnog matriksa tokom razvoja parazitske fibroze i ciroze jetre kod domaćih životinja.