Association of liver and kidney functions with Klotho gene methylation in a population environment exposed to cadmium in China

ABSTRACT

Exposure to the heavy metal cadmium has adverse effects on human health, including DNA methylation. This study aimed to investigate the effects of cadmium on liver and kidney functions and Klotho gene methylation and to explore the relationship of methylation level with indicators of liver and kidney functions. Graphite furnace atomic absorption spectrometry was conducted to determine urinary cadmium, and an automatic biochemical analyzer was used to detect indices of liver and kidney functions. PCR pyrosequencing was performed to detect the methylation rate of Klotho. One-way ANOVA was adopted to compare the differences between groups, and the linear correlation to variables was analyzed. Cadmium exposure was negatively correlated with albumin level (r=-0.143, p=0.021) and positively correlated with urinary β₂-microglobulin level (r=0.229, p<0.001). However, the methylation levels of Klotho gene was decreased and increased by low and high doses of cadmium exposure, respectively. And Klothomethylation levels were negatively correlated with albumin levels and positively correlated with β₂-microglobulin levels.In this study, cadmium exposure affects liver and kidney functions as well as Klotho methylation levels, but the effect on Klotho methylation levels is not linear. Klotho methylation levels also influence liver and kidney functions.

KEYWORDS:

• Cadmium exposure
• liver function
• kidney function
• albumin (ALB)
• β₂-microglobulin (B2M)
• Klotho methylation levels

Additional information

Funding

This study was funded by two grants from the National Natural Science Foundation of China [grant No. 81660528]; The Fundamental Research Funds for Young and Middle-aged Teachers by the Education Department of Guangxi government [KY2016YB076].