Transient receptor potential melastatin 7 aggravates necrotizing enterocolitis by promoting an inflammatory response in children

Transl Pediatr. 2022 Dec;11(12):2030-2039. doi: 10.21037/tp-22-633.

Abstract

Background: As a rare disease in children, necrotizing enterocolitis (NEC) leads to high morbidity and mortality. However, its pathophysiology is largely unclear. Transient receptor potential melastatin 7 (TRPM7) is a membrane protein, which plays key roles in the inflammatory response. This study sought to examine the promoting effect of TRPM7 on NEC in children and explore the therapeutic effect of a TRPM7 inhibitor NS8593.

Methods: First, we detected TRPM7 and NLR family pyrin domain containing 3 (NLRP3) expression and the state of inflammation in children with NEC through quantitative real-time polymerase chain reaction (RT-PCR), Western blot, and enzyme-linked immunosorbent assays. Next, Human intestinal epithelial cell lines were induced to NEC by lipopolysaccharides (LPSs). The level of cytokines and reactive oxygen species (ROS) were tested by RT-PCR and flow cytometry. The TRPM7 mediated calcium flux were determined by fluorescence. In addition, we used the TRPM7 inhibitor NS8593 to treat the in vivo rat model. The mRNA and protein expression were determined by real-time PCR and Elisa analysis, respectively.

Results: TRPM7 and NLRP3 expression was more increased in the samples from children with NEC compared to the control samples. Additionally, the elevated secretion of interleukin-1β, interleukin-6, and tumor necrosis factor alpha was also detected in the serum of children with NEC. These results showed that TRPM7 had a promoting effect on NEC development, possibly via the activation of NLRP3. To test our hypothesis, the TRPM7 inhibitor NS8593 was used to treat the LPS-stimulated IEC-6 cells. We found that the TRPM7 inhibitor NS8593 inhibited LPS-induced cytokine production and exhibited an anti-inflammatory effect by alleviating TRPM7-mediated NLRP3 inflammasome activation. Through in-vivo experiments, we found that TRPM7 was involved in the occurrence of NEC, and its inhibitor NS8593 played a certain therapeutic role in the rat model.

Conclusions: Our study revealed TRPM7 inhibitors attenuated LPS-induced ROS and reduced the release of pro-inflammatory cytokines. It also exhibited protective effects on the NEC model.

Keywords: NLR family pyrin domain containing 3 (NLRP3); NS8593; inflammation; necrotizing enterocolitis (NEC); transient receptor potential melastatin 7 (TRPM7).