ABSTRACT
To investigate apoptosis mechanisms in lymphocytes induced by aluminum trichloride (AlCl3) through the mitochondria-caspase dependent pathway, the spleen lymphocytes of rats were cultured with RPMI-1640 medium and exposed to AlCl3·6H2O in the final concentrations of 0 (control group, CG), 0.3 (low-dose group, LG), 0.6 (mid-dose group, MG), and 1.2 (high-dose group, HG) mmol·L(-1) for 24 h, respectively. Mitochondrial transmembrane potential (ΔΨm), cytochrome C (Cyt C) protein expression in cytoplasm, Caspase-3 and Caspase-9 activity, Bcl-2, Bax, Caspase-3 and Caspase-9 mRNA expressions, DNA ladder and lymphocytes apoptosis index were detected. The results showed that Cyt C protein expression in cytoplasm, Caspase-3 and Caspase-9 activity, Bcl-2, Bax, Caspase-3 and Caspase-9 mRNA expressions, the ratio of Bcl-2 and Bax mRNA expression, lymphocytes apoptosis index increased, while ΔΨm decreased in the AlCl3-treated groups compared with those in CG. The results indicate that AlCl3 induces lymphocyte apoptosis in rats through the mitochondria-caspase dependent pathway.
Subject(s)
Aluminum Compounds/toxicity , Apoptosis/drug effects , Caspase 3/metabolism , Caspase 9/metabolism , Chlorides/toxicity , Lymphocytes/drug effects , Mitochondria/metabolism , Aluminum Chloride , Animals , Apoptosis/physiology , Caspase 3/genetics , Caspase 9/genetics , Cells, Cultured , Cytochromes c/metabolism , Lymphocytes/metabolism , Membrane Potential, Mitochondrial/drug effects , Proto-Oncogene Proteins c-bcl-2/genetics , RNA, Messenger/metabolism , Rats, Wistar , Signal Transduction/drug effects , Spleen/cytology , bcl-2-Associated X Protein/geneticsABSTRACT
The aim of this study was to investigate the effect of norepinephrine (NE) on spleen lymphocytes exposed to aluminum trichloride (AlCl3). In this experiment, lymphocytes were isolated from spleens of healthy Wistar rats weighing about 130 g and cultured with RPMI-1640 medium containing the final concentration of 0.552 mmol/L AlCl3. NE was added to the cultured cells at the final concentrations of 0 (control group), 0.1 (low-dose group), 1 (mid-dose group), and 10 (high-dose group) nmol/L. No addition of both AlCl3 and NE serviced as blank (BG). The T lymphocyte proliferation; the contents of IL-2, TNF-α, and T lymphocyte subsets; immunoglobulin G (IgG) and intracellular cyclic adenosine monophosphate (cAMP) concentrations; and ß2-adrenergic receptor (ß2-AR) density were measured at the end of the culture. The result showed that NE decreased T lymphocyte proliferation and the contents of IL-2, TNF-α, and T lymphocyte subsets whereas increased the concentrations of IgG and intracellular cAMP and ß2-AR density of the lymphocyte exposed to AlCl3. AlCl3 exposure without adding NE showed the similar impacts on these measures compared with BG. The results suggested that NE aggravated AlCl3 immunotoxicity on the lymphocytes and disordered the immune functions of the lymphocyte through the ß2-AR-cAMP signal pathway.
