Immunosuppressant MPA Modulates Tight Junction through Epigenetic Activation of MLCK/MLC-2 Pathway via p38MAPK

Abstract

Background: Mycophenolic acid (MPA) is an important immunosuppressive drug (ISD) prescribed to prevent graft rejection in the organ transplanted patients, however, its use is also associated with adverse side effects like sporadic gastrointestinal (GI) disturbances. Recently, we reported the MPA induced tight junctions (TJs) deregulation which involves MLCK/MLC-2 pathway. Here, we investigated the global histone acetylation as well as gene-specific chromatin signature of several genes associated with TJs regulation in Caco-2 cells after MPA treatment.Results: The epigenetic analysis shows that MPA treatment increases the global histone acetylation levels as well as the enrichment for transcriptional active histone modification mark (H3K4me3) at promoter regions of p38MAPK, ATF-2, MLCK, and MLC-2. In contrast, the promoter region of occludin was enriched for transcriptional repressive histone modification mark (H3K27me3) after MPA treatment. In line with the chromatin status, MPA treatment increased the expression of p38MAPK, ATF-2, MLCK, and MLC-2 both at transcriptional and translational level, while occludin expression was negatively influenced. Interestingly, the MPA induced gene expression changes and functional properties of Caco-2 cells could be blocked by the inhibition of p38MAPK using a chemical inhibitor (SB203580).Conclusions: Collectively, our results highlight that MPA disrupts the structure of TJs via p38MAPK-dependent activation of MLCK/MLC-2 pathway that results in decreased integrity of Caco-2 monolayer. These results led us to suggest that p38MAPK-mediated lose integrity of epithelial monolayer could be the possible cause of GI disturbance (barrier dysfunction) in the intestine, leading to leaky style diarrhea observed in the organ-transplanted patients treated with MPA.

The Immunosuppressant Mycophenolic Acid Alters Nucleotide and Lipid Metabolism in an Intestinal Cell Model

“…Two follow up studies showed that the disruption of intestinal tight junctions was associated with chromatin histone modifications, including an increase in midkine concentrations2829. In contrast to these targeted studies, as aforementioned, in the present study, we took a comprehensive, non-targeted, unique combined proteo-metabolomic approach that resulted in a much more complete picture of the time- and dose-dependent effects of mycophenolic acid on intestinal cell protein concentrations and cell metabolism at various levels of guanosine supplementation.…”

miR-200b inhibits TNF-α-induced IL-8 secretion and tight junction disruption of intestinal epithelial cells in vitro

“…TEER was considered as an indicator of the intact TJ. We used a Millicell-ERS voltohmmeter (Millipore, Bedford, MA) to detect the value of TEER group according to previously reported (23). The monolayer wells with TEER Ͼ400 ⍀·cm 2 were chosen to treat with or without TNF-␣ (10 ng/ml) in the basolateral side of the Transwell chamber.…”

“…Therefore, it makes sense to inhibit IL-8 expression to relieve the acute onset of IBD and prevent the advancement of the inflammation-associated colonic carcinoma. It is acknowledged that IL-8 transcription is regulated by the JNK/c-Jun/AP-1 pathway(23,33). TNF-␣ results in a high level of active phosphorylated c-Jun NH 2terminal kinase (p-JNK), which could phosphorylate c-Jun.…”

“…TNF-␣ results in a high level of active phosphorylated c-Jun NH 2terminal kinase (p-JNK), which could phosphorylate c-Jun. Phosphorylated c-Jun (p-c-Jun) combines with the FOS protein to form the AP-1 complex, thereby contributing to the secretion of immunoregulators such as IL-6 and IL-8(18,23).…”

Petri Net-Based Model of Helicobacter pylori Mediated Disruption of Tight Junction Proteins in Stomach Lining during Gastric Carcinoma

“…The biological effects on activation on these inflammatory cytokines lead to the recruitment and activation of kinases favoring the phosphorylation-dependent disruption of TJ proteins (Figure 3 ). Other major mediators of H. pylori- induced pathogenesis include Protein kinase C (PKC) (Tohidpour, 2016 ), mitogen-activated protein kinase (MAPK) (Ding et al, 2008 ), p38, extracellular signal-regulated kinases (ERK) (Seo et al, 2013 ), and myosin light chain (MLC) (Khan et al, 2015 ). Interplay of these modulators has been shown in the designed model and thus their overall inhibitory effect on TJ proteins has been revealed.…”