cAMP/PKA Signaling Pathway Induces Apoptosis by Inhibited NF-κB in Aluminum Chloride-Treated Lymphocytes In Vitro.

To explore the apoptosis mechanism in lymphocytes of rats induced by aluminum chloride (AlCl3) by activating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway, the splenic lymphocytes of rats were cultured and exposed to different concentrations of AlCl3 for 24 h. The final concentrations of AlCl3 (AlCl3 · 6H2O) in supernatant were 0 (control group, CG), 0.3 mmol/L (low-dose group, LG), 0.6 mmol/L (mid-dose group, MG), and 1.2 mmol/L (high-dose group, HG), respectively. Lymphocytes Apoptosis rate, intracellular cAMP content, PKA, survivin, B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2-associated X protein (Bax) mRNA expressions, and the mRNA and protein expressions of nuclear factor-κ-gene binding (NF-κB, p65) were detected, respectively. The results showed that apoptosis index of lymphocytes, cAMP content in intracellular and PKA mRNA expression were significantly upregulated, whereas NF-κB and survivin mRNA expressions, nuclear NF-κB (p65) protein expression, and the ratio of Bcl-2 and Bax mRNA expression were downregulated in the AlCl3-treated groups compared with those in CG. The results indicated that the activated cAMP/PKA signaling pathway induces apoptosis by inhibited NF-κB in AlCl3-treated lymphocytes in vitro.