Effects of N-Acetyl Cysteine on the Expression of Matrix Metalloproteinases 2 and 9 in the Lung Tissue of Rats Exposed to Cadmium

Abstract

Objectives: This study aimed to investigate the effect of cadmium (Cd) on the matrix metalloproteinases (MMPs) -2 and -9 expression in the lung, and the role of N-acetylcysteine (NAC) in preserving the lung cells against Cd toxicity. Methods: The rats were randomly divided into five groups of G1 (control), G2 (single dose of Cd), G3 (continuous dose of Cd), G4 (single dose of Cd+NAC), and G5 (continuous dose of Cd+NAC). The level of Cd in the blood and lung tissue was measured by atomic absorption spectroscopy. Moreover, the expression of MMP2 and MMP9 genes was considered using RT-PCR. Results: Single and continuous exposure to Cd caused a significant increase in serum and the lung tissue of Cd in G2 (0.23±0.04 mg/L and 0.35±0.047 μg/g tissue) and G3 (0.50±0.068 mg/L and 0.81±0.063 μg/g tissue) groups, compared to other groups (P<0.001). The NAC supplementation significantly decreased Cd levels in the serum and lung tissue samples of rats exposed to single or continuous Cd (P<0.001). Furthermore, exposure to a single and continuous dose of Cd caused a significant increase in the MMP2 expression by 3.24-fold (P=0.003) and 11.9-fold (P<0.001), respectively. Additionally, single and continuous dose treatment of Cd led to a significant increase in the MMP9 expression by 3.20-fold (P=0.004) and 7.54-fold (P<0.001), respectively. The NAC treatments decreased the expression of MMP2 and MMP9 in the lung of rats exposed to single or continuous Cd. Conclusion: The Cd exposure was strongly associated with the accumulation of Cd and overexpression of MMP2 and MMP9 in the lung tissue. Moreover, the NAC can protect the lungs against Cd toxicity by decreasing Cd and down-regulating MMPs.