Abstract

1. We evaluated, in vitro, the interactions between cadmium (Cd) and zinc (Zn) during the proliferation and differentiation process using bone MC3T3-E1 cell line.

2. Cells were treated with CdCl₂ and/or ZnCl₂ for 24 and 48 h and 5 µM CdCl₂ was found as low cytotoxic dose and 25 µM ZnCl₂ as the best Zn treatment for cell proliferation. Gene expression of some bone markers (Runx2, collagen α1 (Colα1), osteocalcin (Oc), alkaline phosphatase (ALP) and bone sialoprotein (BSP)) was studied at 24, 48 and 72 h.

3. Treatment by CdCl₂ depressed Runx2, Colα1, and BSP mRNA levels after 24 h. Oc and ALP gene expression was found to be decreased after 72 h.

4. CdCl₂ -exposure decreased ALP activity and Ca deposit in matrix. In concomitant treatment by CdCl₂ and ZnCl₂, gene expression of osteoblastic markers was found to be up-regulated (p < 0, 05) compared to CdCl₂ treated cells, ALP staining and mineralization were increased.

5. Our results show that Zn could prevent Cd-induced toxicity on MC3T3-E1 cells, probably through the restoration of Runx2, col α1, BSP, ALP and Oc and gene expression inhibited by Cd.

摘要

1. 我们在体外使用骨 MC3T3-E1 细胞系评估了增殖和分化过程中镉 (Cd) 和锌 (Zn) 之间的相互作用。

2. 细胞用 CdCl ₂和/或 ZnCl ₂处理 24 和 48 小时，发现5  µM CdCl ₂是低细胞毒性剂量，25  µM ZnCl ₂是细胞增殖的最佳锌处理。在 24、48 和 72 小时研究了一些骨标记物（Runx2、胶原蛋白 α1（Colα1）、骨钙素（Oc）、碱性磷酸酶（ALP）和骨唾液蛋白（BSP））的基因表达。

3. 24小时后，CdCl ₂处理降低了 Runx2、Colα1 和 BSP mRNA 水平 。发现 Oc 和 ALP 基因表达在 72 小时后降低。

4. CdCl ₂暴露降低了基质中的ALP活性和Ca沉积。在同时用 CdCl ₂和 ZnCl _{2 处理时}，发现与 CdCl ₂处理的细胞相比，成骨细胞标志物的基因表达上调（p  <  0, 05），ALP 染色和矿化增加。

5. 我们的结果表明，Zn 可以防止 Cd 对 MC3T3-E1 细胞的毒性，可能是通过恢复 Runx2、col α1、BSP、ALP 和 Oc 以及受 Cd 抑制的基因表达。