Electroacupuncture at Zusanli Alleviates Sepsis by Regulating the TLR4-MyD88-NF-Kappa B Pathway and Diversity of Intestinal Flora

Abstract

Background. Electroacupuncture (EA) at the Zusanli acupoint (ST36) has shown therapeutic potential for sepsis due to its ability to limit inflammation and to regulate gastrointestinal tract symptoms. However, the mechanisms contributing to the effects of EA at ST36 on sepsis and connections with the intestinal flora remain unclear. This study was designed to explore the effects of EA at ST36 on Toll-like receptor 4 signaling and the intestinal flora. Methods. ICR mice were randomly divided into 4 groups: control group, model group, EA group, and sham EA group. EA at ST36 was performed at 2.5 mA and 2 to 100 Hz, and the 30 min of dense wave was achieved over 5 days. A sepsis model was built by intraperitoneal injection of lipopolysaccharide (LPS, 10 mg/mL). The levels of expression of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), and IL-10 were detected by enzyme-linked immunosorbent assays, and lactate dehydrogenase (LDH) levels in serum were measured by biochemical tests. Expression levels of Bax, Bcl2, cleaved caspase-3, Toll-like receptor (TLR4), nuclear factor-kappa B (NF-κB), and myeloid differentiation factor 88 (MyD88) were assessed by the Western blotting. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining was used to evaluate apoptosis. The intestinal microecology was assessed via 16S rRNA gene sequencing. Results. EA at ST36 reduced the expression of IL-1β, IL-6, and TNF-α and increased the expression of IL-10 to inhibit the inflammatory response. EA at ST36 also inhibited apoptosis, as measured by TUNEL staining, and decreased the Bax/Bcl2 ratio and levels of caspase-3 and cleaved caspase-3, as well as LDH release. Our results suggest that alleviation of sepsis may correlate with the downregulation of levels of TLR4, NF-κB, and MyD88. Importantly, EA at ST36 improved the diversity of the intestinal flora and increased the abundance of Firmicutes and Actinobacteria. Conclusion. EA at ST36 prevented sepsis from worsening by inhibiting inflammation and apoptosis, which correlated with the regulation of the TLR4/NF-κB/MyD88 signaling axis and modulation of the intestinal flora.

Electroacupuncture targeting the immune system to alleviate sepsis

“…Degradation of IκB allows the NF-κB complex to reach the nucleus and initiate transcription of genes encoding inflammatory factors [109] . By downregulating the TLR4/MyD88/NF-κB signaling axis, Zhan et al [110] further demonstrated that EA at “Zusanli (ST36)” could reduce the production of inflammatory factors such as IL-1β, IL-6, and TNF-α, consequently inhibiting the inflammatory response and stopping the progression of sepsis. Huang et al [111] identified another upstream molecule STING.…”

Comprehensive landscape-style investigation of the molecular mechanism of acupuncture at ST36 single acupoint on different systemic diseases

“…Evidence suggests [ 81 ] that electroacupuncture at ST36 can activate the MAPK signaling pathway by modulating gut flora in a model of colitis, affecting ERK1/2 and JNK subfamily signaling molecules, upregulating the expression of intercellular junction complex proteins zona occludens 1 (ZO-1), Occludin, E-Cadherin, Mucin 2 (MUC2), and reduce apoptosis and oxidative stress in intestinal epithelial cells (IECs) to protect intestinal barrier integrity, and reduce disease activity index (DAI) and histological scores in chronic colitis. Studies have found [ 82 , 83 ] that the overall structure of the intestinal flora was adjusted with the improvement of the degree of intestinal inflammation. Electroacupuncture at ST36 modulates and recognizes TLR on the IEC, which are channeled through the TLR4/myeloid differentiation factor 88 (MyD88) signaling pathway to induce activation of immune cell responses, while activation of the TLR4/MyD88 signaling pathway can affect the downstream NF-κB signaling pathway, modulating inflammatory signaling cascades and inhibition of the secretion of pro-inflammatory mediators C-reactive protein (CRP), interferon-γ (IFN-γ), TNF-α, IL-6, and Influence the overall structure of Lactobacillus reuteri, Lactobacillus vaginalis, Bacteroidales, and Firmicutes , and reduce colonic mucosal damage.…”