Stereological evaluation of liver of rabbit fetuses after transplantation of human Wharton’s jelly-derived mesenchymal stromal/stem cells

Abstract

In utero xenotransplantation of stem cells in the abnormal fetuses is effectively used to treat several genetic illnesses. The current research was aimed to evaluate structural and morphological alterations in the liver of rabbit fetuses following xenotransplantation of human Wharton’s jelly-derived mesenchymal stromal/stem cells (hWJ-MSCs), using a stereological technique. hWJ-MSCs were isolated from human umbilical cord and their authenticity was established by flow-cytometry and differentiation. At gestational day 14, the rabbits were anesthetized and hWJ-MSCs were injected into uteri of 24 fetuses. 22 fetuses were born successfully. Ten rabbit liver specimens were prepared from injected fetuses including eight rabbits on day 3 following birth and two rabbits on the 21^st post-natal day. The non-injected fetuses were considered as positive controls. The livers of the control and hWJ-MSCs-treated rabbits were fixed, processed, stained, and examined through stereological approaches. In the hWJ-MSCs-treated group, the mean of liver weight and volume enhanced ~42% and ~78% comparing with the control ones. The total volume of the hepatocytes increased ~63% and that of sinusoids almost triplicated in the treated rabbits. The total volume of the central veins increased ~70%. The total number corresponding to hepatocytes in the experimental group enhanced ~112% in comparing with control rabbits. The total volume of the hepatocyte nuclei in the experimental group enhanced ~117% in comparing with control rabbits. In conclusion, after xenotransplantation of human MSCs, host tissue microenvironments (here the rabbit liver) altered quantitative factors corresponding to the liver tissue and hepatocyte morphometric indices.