Purpose Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease in neonates, with high death rate. The pathogenesis of NEC is particularly complex, mainly involving inflammation and hypoxic damage. In vitro cell model is an indispensable tool to study the pathogenesis of NEC. This study explored the effects of different stress factors on intestinal injury in vitro. Methods IEC-6 cells were stimulated by exposure to different stressors, including lipopolysaccharide (LPS), cobalt chloride (CoCl2), and a combination of both. Cell viability was detected by CCK-8 assay. The expression of inflammatory cytokines (IL-6 and TNFα) at the gene and protein levels were measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and enzyme-linked immune-sorbent assay (ELISA). While the expression of tight junction proteins (Claudin-1 and zonula occludens [ZO]-1) were evaluated by qRT-PCR and western blotting, respectively. Results The decrease in IEC-6 cell viability was observed after stimulation by CoCl2 alone or in combination with LPS, but not after stimulation with LPS alone. The expression of IL-6 and TNFα increased in each group, especially in the combined stimulation group. After stimulation with CoCl2 alone or in combination with LPS, a decrease in Claudin-1 was observed, but an increase was detected after stimulation with LPS alone. ZO-1 decreased in both mRNA and protein levels after combined stimulation. Conclusion The combined stimulation of CoCl2 and LPS on IEC-6 cells could simultaneously induce severe inflammation and barrier damage, which may better simulate the pathological process of NEC. Further research is needed to determine whether this in vitro model can be used to study the pathogenesis of NEC.

Background: Neonatal sepsis is a systemic inflammatory response syndrome in neonates. The molecular mechanism of neonatal sepsis remains incompletely clarified. The purpose of this study was to explore the potential value of receptor interacting protein 3 (RIP3) in neonatal sepsis.Methods: 93 neonates with sepsis and 93 neonates without infectious diseases were enrolled in this study from September 2019 to March 2021. Plasma RIP3 was detected by enzyme-linked immunosorbent assay (ELISA) and assessed along with whole blood hypersensitive C-reactive protein (hs-CRP) and platelet count (PLT). Differences of RIP3, hs-CRP and PLT between the two groups were compared. Changes of the three indicators in sepsis were also observed after treatment. The diagnostic value of indicators for neonatal sepsis was evaluated by receiver operating characteristic (ROC) curve.Results: In sepsis group, RIP3 and hs-CRP levels were significantly higher than those in control group (RIP3, p ＜ 0.0001; hs-CRP, p ＜ 0.0001), and PLT level was significantly lower than that in control group (p＜0.0001). After treatment, RIP3 and hs-CRP levels among septic survivors had a significant decrease (p＜0.0001) and PLT level had a significant improvement (p=0.0028). With RIP3＞15464.72 pg/mL, CRP>3.24 mg/L, PLT<205.00×109 /L as the positive criteria, the sensitivity of the three indicators in the diagnosis of neonatal sepsis was 68.8%, 64.5%, 59.1%, and the specificity was 91.4%, 82.8%, 79.6%, respectively. The combination of RIP3, CRP and PLT showed 76.3% sensitivity and 94.6% sensitivity.Conclusions: RIP3 may attribute to the early diagnosis and understanding therapeutic effect of neonatal sepsis. The combined detection of RIP3, CRP and PLT may be more effective than individual ones in the diagnosis of neonatal sepsis.

Background Late-onset sepsis (LOS) is a systemic inflammatory response syndrome in neonates, and the molecular mechanism of LOS is incompletely characterized. The purpose of this study was to explore the potential value of receptor interacting protein 3 (RIP3) in LOS. Methods 63 neonates with LOS supported by positive culture and 79 neonates without sepsis were enrolled in this study from September 2019 to March 2021. Plasma RIP3 was detected by enzyme-linked immunosorbent assay (ELISA) and assessed along with the whole blood hypersensitive C-reactive protein (hs-CRP) level and platelet count (PLT). Differences in RIP3, hs-CRP and PLT between the two groups were compared. Changes in the three indicators in sepsis were also observed after treatment. The diagnostic value of indicators for LOS was evaluated by receiver operating characteristic (ROC) curve analysis. Results In the sepsis group, RIP3 and hs-CRP levels were significantly higher than those in the control group (RIP3, p < 0.0001; hs-CRP, p < 0.0001), and PLT was significantly lower than that in the control group (p < 0.0001). After treatment, RIP3 and hs-CRP levels among septic survivors were significantly decreased (p < 0.0001) and PLT significantly improved (p = 0.0216). With RIP3 > 15,845.19 pg/mL, hs-CRP > 5.00 mg/L, and PLT < 204.00 × 109/L as the positive criteria, the sensitivity values of the three indicators in the diagnosis of LOS were 69.8%, 60.3%, 60.3%, respectively, and the specificity values were 92.4%, 96.2%, 79.8%, respectively. The combination of RIP3, hs-CRP and PLT had a sensitivity of 77.8% and specificity of 97.5%. Conclusions RIP3 may contribute to the early diagnosis of LOS and monitoring of treatment effect. The combined detection of RIP3, hs-CRP and PLT may be more effective than individual detection in the diagnosis of LOS.