The Apoptosis and Expression of Bcl-2, Bcl-xS, Bax Proteins in Fetal Brain after Treating Pregnant Mice with Endotoxin

PURPOSE: Apoptosis is active cell death which plays an important role in developing normal tissues. Various conditions such as genetic defects, drugs, ischemia or infections are known to induce apoptosis. We studied the effect of maternal infection on fetal brain development during pregnancy. METHODS: We treated 46 C3H pregnant mice with lipopolysaccharide (LPS) or phosphat-buffered saline and observed the changes in apoptosis and expression of bcl-2, bcl-xS, bax. The fetal brain tissues were removed 1-48 hours after LPS treatment. The number of apoptosis per 100 neurons and glial cells was counted in H&E stained tissue and was analyzed statistically. Immunohistochemical staining with primary antibodies of bcl-2, bcl-xS, bax was done and their expression was classified by the degree of staining. RESULTS: The number of apoptosis was increased significantly in both neurons and glial cells of LPS-treated group and its degree of staining was more remarkable in glial cells. Immunohisto chemistry for bcl-2, bcl-xS, bax oncoprotein revealed mildly decreased expression of bcl-2 and markedly increased expression of bax in both neurons and glial cells, but it was more remarkable in glial cells. Immunochemistry for bcl-xS revealed no expression in neurons and minimal expression of bcl-xS in glial cells in both study groups. CONCLUSOIN: We observed an increase in the number of apoptosis, mildly decreased expression of bcl-2 and markedly increased expression of bax in both neurons and glial cells of fetal brain after treating pregnant mice with LPS. Maternal infection during pregnancy may have profound effects on developing fetal brain.

Comparison Study between Immunohistochemical Staining and Enzyme Linked Immunosorbent Assay in Metalloproteinases and Tissue inhibitor of Metalloproteinases in Virus induced Myocarditis

PURPOSE: Most tissue disruption of extracellular matrix is mediated by extracellular proteinases. Matrix metalloproteinases(MMP) and tissue inhibitor of matrix metalloproteinases(TIMP) are associated with wound healing and repair. There has been no study done on MMP and TIMP in myocarditis. METHODS: Coxsackie B virus(4,000 plaque forming unit) was injected into Balb/c mice by intraperitoneal injection. Histopathological finding was observed by H-E staining. Immunohistochemical staining was performed using the Labelled Streptavidin Biotin(LSAB) kit for MMP-2, TIMP-2, and Interleukin(IL) 6. The results were compared to the serum levels by ELISA method. RESULTS: MMP-2 was strongly expressed in complicated myocarditis such as calcification, severe fibrosis, thrombosis, or dilated cardiomyopathy compared to normal or uncomplicated myocarditis. TIMP-2 expression was decreased in severe myocarditis. Serum MMP-2 levels were significantly higher in complicated myocarditis, but TIMP-2 levels were significantly lower. There was significant correlation between the grade of immunohistochemical staining and serum MMP-2 or TIMP-2 level by ELISA method. IL-6 was strongly expressed in immunohistochemical staining according to the severity of inflammation. CONCLUSION: There was significant correlation between grade of immunohistochemical staining and serum levels of MMP or TIMP by ELISA method. Accurate estimations of serum MMP and TIMP levels would be useful for the diagnosis and follow up of myocarditis.

The Role of Apoptosis in Adriamycin Induced Cardiotoxicity and Preventive Effect of L-carnitine in Rat

PURPOSE: Adriamycin is very important in cancer chemotherapy. Unfortunately, the drug shows cumulative dose dependent cardiotoxicity. The precise mechanism of this remains unclear. It has been shown that adriamycin induces programmed cell death or apoptosis in many tissues. But the role of apoptosis in adriamycin induced cardiotoxicity is uncertain. METHODS: Sprague-Dawley rats were divided into four groups of ten animals each. All four groups were given intraperitoneal injections for 4 weeks. The first group was given 0.9% normal saline. The second group was injected twice a week with adriamycin (5mg/kg), the third group with adriamycin (5mg/kg) and L-carnitine (200mg/kg). The fourth group was injected with only L-carnitine. Cell morphology was evaluated by light and electron-microscopy. Apoptosis was detected by labelling nicked ends of DNA fragments using Tunnel staining kit. RESULTS: There was no difference of the left ventricular internal dimension and ventricular septal thickness among the four groups. Apoptosis was significantly increased in the adriamycin treated group compared to the control group (P<0.05). Addition of L-carnitine to adriamycin induced apoptosis compared significantly to apoptosis in the adriamycin only group (P<0.05). CONCLUSION: Apoptosis may play an important role in adriamycin induced cardiomyopathy. L- carnitine reduces adriamycin induced apoptosis.