Dovhal H. V., Dovhal M. A., Romanenko O. A., Zharikov M. Yu., Romanenko K. L.
The aim of the study was to determine the expression of the spectrum of immunohistochemical markers in the liver in the prenatal period of rats after exposure to lead acetate during pregnancy. From the first day of pregnancy, female Wistar rats were exposed to lead acetate in an aqueous solution at a dose of 20 mg/kg per os daily. The liver of rat fetuses underwent the immunohistochemical analysis on the 14th, 16th and 18th day of prenatal life; the control was the liver of intact rat fetuses. The RUNX2 marker showed a clear but not uniform expression. More than half of the hepatocytes actively accumulated dye granules. High intensity of reaction to this marker was observed in endothelial cells of the liver. Thus, RUNX2 expression is detected in cell types other than osteoblasts and endotheliocytes, as previously described. The expression of the MMP2 was detected as very small granules accumulation, unevenly distributed in the cytoplasm of epithelial cells of the parenchyma, which allowed to estimate it as very weak. In liver endothelial cells, the concentration of the dye was more pronounced, but did not reach the moderate level of intensity. The accumulation of granules, which reflected the expression intensity of the marker p21, occurred in hepatocytes mainly in the peripheral regions of the cytoplasm. In the central regions of the liver the intensity of the reaction was moderate, while in the areas under the liver capsule the number of granules in hepatocytes was slightly higher. Endothelial cells that covered the liver beams showed the uniform high intensity of the reaction. Hematopoietic islets also showed a positive moderate response to this marker. The CYD1 was not significantly expressed in the liver parenchyma. It was detected in the cytoplasm of hepatocytes, but in some epithelial cells, we did not observe CYD1 marker. Endothelial cells also showed weak binding to the CYD1. After exposure to the toxicant, we observed the decrease in the expression of the marker RUNX2 in the cytoplasm of hepatocytes compared to normal liver. In the cytoplasm of hepatocytes were found small but noticeable positive reaction for MMP2, granules occupying areas near the cytolemma. The number of such granules fluctuated, we estimated such intensity of reaction in a hepatic epithelium as weak. Ubiquitously in the organ, hepatocytes showed the moderate reaction with the marker CYD1. Hepatocytes, which entered the path of mitosis and showed a metaphase plate, looked noticeably more stained. Thus, the toxicant does not significantly affect the expression of factors that regulate cytokinesis. The reaction with the marker CYD1 seemed to be intact in the liver endothelial cells. Hepatocytes showed heterogeneity in the degree of expression of the p21 marker in both central and peripheral parts of the organ. Generally, the hepatic epithelium showed a significant decrease in expression of this marker, but the liver endothelial cells only a slight decrease. It is possible that the toxicant inhibits the regenerative capacity of the liver, which is associated with regulation through factor p21. We conclude that during 14-18 days of the prenatal period in rats, the active expression of RUNX2 normally occurs in hepatocytes and endotheliocytes of the liver with a tendency to increase. The MMP2 showed a weak response in hepatocytes and endothelial cells with almost no dynamics. The p21 marker showed the moderate reaction in hepatocytes with a tendency to increase, and high expression – in the endothelial cells. CYD1 was poorly expressed in hepatocytes and endothelial cells, disappearance of expression in the hepatic epithelium occurred by day 18, but it was found in stellate liver cells. After exposure to lead acetate during the prenatal period, the expression of RUNX2 and p21 in hepatocytes decreases. The toxicant has almost no effect on the level of RUNX2 and CYD1 synthesis in liver endothelial cells, whereas the expression of p21 decreases in both cell types.
liver, prenatal period, rats, immunohistochemical markers, lead acetate.
«Bulletin of problems biology and medicine» Issue 3 (161), 2021 year, 253-258 pages, index UDK 611.36: 611.136.41:611.013]-092.9
