TNF-α/TNFR1 regulates the polarization of Kupffer cells to mediate trichloroethylene-induced liver injury

We have previously shown trichloroethylene (TCE) induced immune liver injury, and TNF-alpha/TNER1 pathway as a probably mechanism underlying the immune damage, but the pathogenic mechanism is still unclear. The study aims to investigate whether TNF-alpha and its receptors regulate Kupffer cell polarization and downstream inflammation signaling pathways during TCE sensitization, to clarify the mechanism of TCE-mediated immune liver injury. 6-8 weeks old SPF BALB/c female mice were used to establish a TCE sensitization model. We found that in the TCE sensitization positive group, liver injury was aggravated, Kupffer cells activated and polarized to M1 type. The expression of M1 Kupffer cell marker proteins CD11c and CD16/32 increased in the TCE positive group, so did TNF-alpha and TNFR1 in liver. The expression of P-IKK protein, PP65 protein and P-STAT3 protein increased in the TCE sensitization positive group, and the downstream inflammatory factors IL-1 beta and IL-6 also increased in the TCE sensitization positive group. After using the TNFR1 inhibitor R7050, we found that M1 Kupffer cell polarization, TNF-alpha expression, signal pathway expression and inflammatory factors IL-1 beta and IL-6 expression declined, and the liver damage relieved. Briefly, the use of R7050 to inhibit TNF-alpha/TNER1 changing the polarization of liver M1 Kupffer cell, thereby inhibiting the activation of related downstream signaling pathways and reducing the secretion of inflammatory factors. TNF-alpha/TNER1 regulates the polarization of M1 Kupffer cells inflammatory play an important role in liver immune damage.

Automated summary

This study aimed to investigate the role of TNF-alpha and its receptors in regulating Kupffer cell polarization and downstream inflammation pathways during TCE sensitization, in order to clarify the mechanism of TCE-mediated immune liver injury. The results showed that TCE sensitization led to exacerbated liver injury, activation and polarization of M1 type Kupffer cells, increased expression of TNF-alpha and its receptors, and upregulation of downstream inflammatory factors. Inhibition of TNF-alpha/TNER1 pathway with R7050 reduced M1 Kupffer cell polarization, downstream signaling pathway activation, and inflammatory factor secretion, alleviating liver damage.