Upregulation of PRMT6 by LPS suppresses Klotho expression through interaction with NF-κB in glomerular mesangial...

Area of Science:

• Cellular Biology
• Immunology
• Epigenetics

Background:

• Gram-negative bacteria release lipopolysaccharide (LPS), activating immune responses.
• Epigenetic modifications, including DNA and protein methylation, influence immune gene expression.
• Previous studies showed LPS decreased Klotho protein in rats, but cellular effects were unclear.

Purpose of the Study:

• To investigate the effect of LPS on Klotho expression in glomerular mesangial MES-13 cells.
• To explore the role of epigenetic modifications, specifically methylation, in LPS-induced changes.
• To identify molecular mechanisms linking LPS, methylation, and Klotho regulation.

Main Methods:

• Treatment of MES-13 cells with LPS.
• Assessment of global DNA and protein methylation levels.
• Analysis of enzyme expression, including protein arginine methyltransferase 6 (PRMT6).
• Evaluation of Klotho protein expression using specific inhibitors (5-Aza-2'-dc, AMI-1, PDTC, AdOx).
• Investigation of NF-κB interaction with PRMT6 and its nuclear translocation.

Main Results:

• LPS induced global DNA and protein methylation in MES-13 cells.
• LPS upregulated PRMT6 expression and decreased Klotho protein levels.
• Klotho expression was restored by 5-Aza-2'-dc, AMI-1, and PDTC, but not AdOx.
• NF-κB was identified as an arginine-methylated substrate interacting with PRMT6.
• PRMT inhibition blocked LPS-induced NF-κB nuclear translocation.

Conclusions:

• LPS triggers epigenetic alterations, including PRMT6 upregulation and subsequent Klotho downregulation in kidney mesangial cells.
• NF-κB, regulated by PRMT6, plays a key role in the negative regulation of Klotho expression following LPS exposure.
• These findings elucidate a novel epigenetic pathway influencing innate immunity and Klotho regulation.