OBJECTIVETo explore the expression of Toll like receptor 4 (TLR4) on the pulp cells and the change of related signaling molecules under the condition of concomitant lipopolysaccharide (LPS) and transforming growth factor-beta 1 (TGF-beta 1) during the course of pulpitis.

METHODSAfter treated by LPS and TGF-beta 1, the expression of TLR4 on pulp cells was detected by flow cytometry (FCM). The expressions of signaling molecules evolutionarily conserved signaling intermediate in Toll pathways (ECSIT) and nuclear factor-kappaB (NF-kappaB) were detected by real-time polymerase chain reaction (real-time PCR) and Western blot. The secretion of interleukin-6 (IL-6) was detected by enzyme-linked immunosorbent assay (ELISA). Furthermore, the change of corresponding targets in inflamed pulp cells from clinical samples were detected by real-time PCR.

RESULTSAfter treated by LPS and TGF-beta 1 in vitro, there was no change in the expression of TLR4 on pulp cells, but the secretion of proinflammatory cytokines IL-6 increased. LPS and TGF-beta 1 could also increase the expression of signal downstream ECSIT and actived NF-kappaB. Furthermore, the expression of TLR4 mRNA had no increase in inflamed pulp cells from clinical samples, while the expression of TGF-beta 1, ECSIT and IL-6 mRNA increased through real-time PCR.

CONCLUSIONDuring the course of pulpitis, although the expression of TLR4 on pulp cells was inhibited by increased expression of TGF-beta 1, the TLR4 pathway was still activated. This effect could be caused through activation of ECSIT mediated by LPS, which might inhibit the TGF-beta 1 pathway.

Dental Pulp ; Epithelial Cells ; Humans ; Interleukin-6 ; Lipopolysaccharides ; NF-kappa B ; Signal Transduction ; Toll-Like Receptor 4 ; Transforming Growth Factor beta ; Transforming Growth Factor beta1

Objective:To explore the characteristics of gut microbiota in the preoperative, short-term postoperative and long-term postoperative period at (15.61±4.51) months in children with ventricular septal defect (VSD) of congenital heart disease (CHD) treated with cardiopulmonary bypass (CPB).Methods:A prospective study was conducted.In Guangzhou Women and Children′s Medical Center, 13 patients with VSD who were scheduled for CPB and additional 10 age- and gender-matched healthy infants as pre-CPB control group from January 2021 to January 2022 were enrolled.Fecal samples were collected at pre- and early post-CPB.Meanwhile, 18 gender- and CHD diagnosis and operation-matched patients at (15.61±4.51) months after CPB and 8 healthy age- and gender-matched children as long-term control group after CPB were also enrolled, and fecal samples were collected.16S rRNA sequencing of fecal samples from all subjects were performed and comparing the differences in gut microbiota between two groups via comparing alpha and beta diversity, parameter test or nonparametric test, and LEfSe analysis.Results:Compared with those of pre-CPB control group, there was a significant difference in the composition of gut microbiota in the preoperative period of VSD children, with significantly increased abundances of Enterobacteriaceae and Shigella, and decreased abundance of Bifidobacterium (all P<0.05). The diversity of gut microbiota was comparable in VSD children before CPB and in the short period time after CPB (all P>0.05), except for the abundances of Clostridium and Streptococcus (all P<0.05), and there was no significant difference in the relative abundances of other highly abundant gut bacteria between the two periods (all P>0.05). Compared with that in VSD children in the short period time after CPB, the abundances of short-chain fatty acids-producing microbes were significantly higher at (15.61±4.51) months postoperatively (all P<0.05), and the gut bacteria profile was similar to that of the long-term control group after CPB (all P>0.05). Conclusions:Gut microbiota imbalance exists in VSD children before CPB.The gut microbiota profile is not influenced by CPB, which returns normal at (15.61±4.51) months postoperatively.