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Published on: May 13, 2016
MEHP promotes liver fibrosis by down-regulating STAT5A in BRL-3A hepatocytes
Yuezhu Zhang1, Ju Hui1, Yan Xu1
1Department of Occupational and Environmental Health, School of Public Health, Jilin University, Changchun, China.
Objective:
As an environmental endocrine disruptor, mono-2-ethylhexyl phthalate (MEHP) can interfere with liver metabolism and lead to liver diseases. We aimed to investigate the role of MEHP in liver fibrosis and its molecular mechanism.
Methods:
BRL-3A hepatocytes were exposed to MEHP (0, 10, 50, 100 and 200 μM) for 24 h. STAT5A gene was overexpressed by lentivirus transfection. The reactive oxygen species (ROS) was tested by the flow cytometer. The malondialdehyde (MDA), glutathione peroxidase (GSH-PX), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were detected by commercial kits. Real-Time PCR and Western blot were performed to test the relative mRNA and proteins levels, respectively.
Results:
MEHP exposure significantly induced oxidative damage in BRL-3A cells, which inhibited the expression of STAT5A and promoted the expression of fibrosis related proteins MMP2, MMP9, TIMP2 and CTGF. After over-expression of STAT5A gene in BRL-3A cells, the elevated expression levels of CTGF, MMP2, MMP9 and TIMP2 induced by MEHP exposure were significantly reversed.
Conclusion:
This study demonstrated that MEHP exposure inhibited the expression of STAT5A by causing oxidative damage in BRL-3A hepatocytes, thus accelerating the expression of key molecules in fibrosis and promoting the occurrence of liver fibrosis.
Insights
Mono-2-ethylhexyl phthalate (MEHP) causes liver fibrosis by inducing oxidative damage and inhibiting STAT5A expression. Restoring STAT5A levels reverses these fibrosis-promoting effects, highlighting its protective role.
Area of Science:
- Hepatology
- Toxicology
- Molecular Biology
Background:
- Mono-2-ethylhexyl phthalate (MEHP) is an environmental endocrine disruptor linked to liver metabolic dysfunction and disease.
- Understanding the molecular mechanisms underlying MEHP-induced liver injury is crucial for developing targeted interventions.
Purpose of the Study:
- To investigate the role of MEHP in promoting liver fibrosis.
- To elucidate the molecular mechanisms by which MEHP affects liver cells, focusing on oxidative stress and STAT5A signaling.
Main Methods:
- BRL-3A hepatocytes were exposed to varying concentrations of MEHP.
- Reactive oxygen species (ROS) and oxidative stress markers (MDA, GSH-PX) were measured.
- Gene and protein expression of STAT5A, CTGF, MMP2, MMP9, and TIMP2 were analyzed using Real-Time PCR and Western blot.
- STAT5A gene overexpression was achieved via lentivirus transfection.
Main Results:
- MEHP exposure induced significant oxidative damage in hepatocytes.
- MEHP inhibited STAT5A expression while upregulating fibrosis-related proteins (MMP2, MMP9, TIMP2, CTGF).
- Overexpression of STAT5A reversed the MEHP-induced increases in fibrosis markers.
Conclusions:
- MEHP promotes liver fibrosis by inducing oxidative damage, which suppresses STAT5A expression.
- STAT5A plays a protective role against MEHP-induced liver fibrosis.
- Targeting the MEHP-STAT5A pathway may offer therapeutic strategies for liver fibrosis.
