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

Autophagy Improves Inflammatory Response in Sepsis Accompanied by Changes in Gut Microbiota

Background: Sepsis is defined as a life-threatening disease. Autophagy and the microbiome are increasingly connected with sepsis. The aim of this study was to investigate the protective effect of autophagy and the possible mechanisms. Methods: The septic rat model was established by cecal ligation perforation (CLP). Rapamycin (Rap), 3-methyladenine (3-MA), and chloroquine (CQ) were administered to interfere autophagy. Western blot (WB) was used to detect the expression of key proteins in autophagy. Hematoxylin and eosin (H&E) staining and enzyme-linked immunosorbent assays (ELISAs) were used to identify the effect of autophagy on various organs. 16S ribosomal RNA gene sequencing was used to analyze the changes of the gut microbiota. Results: Rap significantly upregulated the expression of key autophagy proteins, and 3-MA reduced the relative expression compared to the CLP group. The autophagic flux showed a corresponding trend. Interestingly, the autophagy inducer significantly decreased the mortality and the lipopolysaccharide (LPS) level in serum compared with the CLP group. Autophagy activation significantly improves the inflammatory response in sepsis. Histopathological sections showed that CLP destroyed the tight junctions between ileal epithelial cells, while autophagy induction reversed the damage. The sequencing results showed that autophagy activation increased the alpha diversity and alterted the composition and structure of gut microbiota. The abundance of Proteobacteria was markedly decreased in the Rap group, whereas Bacteroidetes was notably increased compared with the CLP group. Additionally, the protective effect of autophagy further changed the biomarkers in the microbial community. The top 35 functions in each sample were analyzed to obtain 18 genes including RNA synthesis, ATP binding and transport, chromosome assignment, osmotic polysaccharide transport, transcytosis, and methylation. Conclusion: Autophagy is able to improve inflammation and may directly or indirectly regulate the microbiota of septic rats. Autophagy may be an important target for future clinical interventions in the treatment of sepsis.

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

The principle of acupoint stimulation efficacy is based on traditional meridian theory. However, the molecular mechanisms underlying the therapeutic effects of acupoints in treating diseases remain unclear in modern scientific understanding. In this study, we selected the ST36 acupoint for investigation and summarized all relevant literature from the PubMed database over the past 10 years. The results indicate that stimulation of ST36 single acupoints has therapeutic effects mainly in models of respiratory, neurological, digestive, endocrine and immune system diseases. And it can affect the inflammatory state, oxidative stress, respiratory mucus secretion, intestinal flora, immune cell function, neurotransmitter transmission, hormone secretion, the network of Interstitial Cells of Cajal (ICC) and glucose metabolism of the organism in these pathological states. Among them, acupuncture at the ST36 single point has the most prominent function in regulating the inflammatory state, which can mainly affect the activation of MAPK signaling pathway and drive the "molecular-cellular" mode involving macrophages, T-lymphocytes, mast cells (MCs) and neuroglial cells as the core to trigger the molecular level changes of the acupuncture point locally or in the target organ tissues, thereby establishing a multi-system, multi-target, multi-level molecular regulating mechanism. This article provides a comprehensive summary and discussion of the molecular mechanisms and effects of acupuncture at the ST36 acupoint, laying the groundwork for future in-depth research on acupuncture point theory.

Mycobacterium tuberculosis virulence protein ESAT-6 influences M1/M2 polarization and macrophage apoptosis to regulate tuberculosis progression

BACKGROUND

Tuberculosis (TB) is an infectious disease caused by infection with Mycobacterium tuberculosis (Mtb), and it remains one of the major threats to human health worldwide. To our knowledge, the polarization of M1/M2 macrophages were critical innate immune cells which play important roles in regulating the immune response during TB progression.

OBJECTIVE

We aimed to explore the potential mechanisms of M1/M2 macrophage polarization in TB development.

METHODS

THP-1 macrophages were treated with early secreted antigenic target of 6 kDa (ESAT-6) protein for an increasing time. The polarization profiles, apoptosis levels of M1 and M2 macrophages were detected by RT-qPCR, immunofluorescence, Western blot and flow cytometry.

RESULTS

ESAT-6 initially promoted the generation of pro-inflammatory M1-polarized macrophages in THP-1 cells within 24 h, which were suppressed by further ESAT-6 treatment at 30-42 h. Interestingly, ESAT-6 continuously promoted M2 polarization of THP-1 cells, thereby maintaining the anti-inflammatory response in a time-dependent manner. In addition, ESAT-6 promoted apoptotic cell death in M1-polarized macrophages, which had little effects on apoptosis of M2-phenotype of macrophages. Then, the potential underlying mechanisms were uncovered, and we verified that ESAT-6 increased the protein levels of TLR4, MyD88 and NF-κB to activate the TLR4/MyD88/NF-κB pathway within 24 h, and this signal pathway was significantly inactivated at 36 h post-treatment. Interestingly, the following experiments confirmed that ESAT-6 TLR4/MyD88/NF-κB pathway-dependently regulated M1/M2 polarization and apoptosis of macrophage in THP-1 cells.

CONCLUSION

Our study investigated the detailed effects and mechanisms of M1/M2 macrophages in regulating innate responses during TB development, which provided a new perspective on the development of treatment strategies for this disease.