EGCG induces G-CSF expression and neutrophilia in experimental sepsis

A novel prognosis evaluation indicator of patients with sepsis created by integrating six microfluidic-based neutrophil chemotactic migration parameters

Impaired neutrophil migration in sepsis is associated with a poor prognosis. The potential of utilizing neutrophil chemotaxis to assess immune function, disease severity, and patient prognosis in sepsis remains underexplored. This study employed an innovative approach by integrating a multi-tip pipette with a Six-Unit microfluidic chip (SU6-chip) to establish gradients in six microchannels, thereby analyzing neutrophil chemotaxis in sepsis patients. We compared chemotactic parameters between healthy controls (NH = 20) and sepsis patients (NS1 = 25), observing significant differences in gradient perception time (GP), migration distance (MD), peak velocity (Vmax), chemotactic index (CI), reverse migration rate (RM), and stop migration number (SM). A novel composite indicator, the Sepsis Neutrophil Migration Evaluation (SNME) index, was developed by integrating these six chemotactic migration parameters. The SNME index and individual chemotaxis parameters showed significant correlations with the Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE II) score, hypersensitivity C-reactive protein (hs-CRP), and heparin-binding protein (HBP). Moreover, the SNME index demonstrated potential for monitoring sepsis progression, with ROC analysis confirming its predictive accuracy (area under the curve [AUC] = 0.895, cutoff value = 31.5, specificity = 86.73 %, sensitivity = 86.71 %), outperforming individual neutrophil chemotactic parameters. In conclusion, the SNME index represents a promising new tool for adjunctive diagnosis and prognosis assessment in patients with sepsis.

Integrated Network Pharmacology and Molecular Docking to Elucidate the Efficacy and Potential Mechanisms of Tea Ingredients in Sepsis Treatment

Sepsis, a critical health condition induced by an overactive innate immune response and reactive oxygen species (ROS)-driven host damage through apoptosis and ferroptosis, continues to pose a significant mortality risk. Despite accumulating evidence of the potential therapeutic properties of tea ingredients, their specific anti-sepsis potential remains inadequately explored. This study comprehensively investigates the targeted genes of tea ingredients, notably epigallocatechin 3-gallate (EGCG), and their correlation with sepsis signature genes. Our findings elucidate that tea ingredients, especially EGCG, exhibit substantial potential in mitigating inflammation and sepsis-induced damage. Through the inhibition of the MAPK cascade and macrophage activation and by impeding the transcriptional activity of RELA (transcription factor p65) in sepsis, EGCG demonstrates significant anti-sepsis efficacy. Molecular docking analysis further underpins this by revealing the close proximity of EGCG and (-)-catechin gallate binding sites to that of RELA on DNA. Subsequent in vitro assays illuminated EGCG's instrumental role in modulating macrophage M2 polarization, balancing M1 and M2 differentiation of bone marrow-derived macrophages (BMDMs), curtailing inflammatory factor secretion, and inhibiting ROS production. Moreover, EGCG effectively suppresses the expression of ferroptosis/apoptosis markers in LPS-induced macrophages during their early stages. Our study advances our understanding of sepsis prevention and treatment strategies, suggesting that tea ingredients such as EGCG could play a pivotal role in developing future sepsis therapies due to their protective effects.

Neuron-immunity communication: mechanism of neuroprotective effects in EGCG

Epigallocatechin gallate (EGCG), a naturally occurring active ingredient unique to tea, has been shown to have neuroprotective potential. There is growing evidence of its potential advantages in the prevention and treatment of neuroinflammation, neurodegenerative diseases, and neurological damage. Neuroimmune communication is an important physiological mechanism in neurological diseases, including immune cell activation and response, cytokine delivery. EGCG shows great neuroprotective potential by modulating signals related to autoimmune response and improving communication between the nervous system and the immune system, effectively reducing the inflammatory state and neurological function. During neuroimmune communication, EGCG promotes the secretion of neurotrophic factors into the repair of damaged neurons, improves intestinal microenvironmental homeostasis, and ameliorates pathological phenotypes through molecular and cellular mechanisms related to the brain-gut axis. Here, we discuss the molecular and cellular mechanisms of inflammatory signaling exchange involving neuroimmune communication. We further emphasize that the neuroprotective role of EGCG is dependent on the modulatory role between immunity and neurology in neurologically related diseases.

Molecular Mechanisms of the Anti-Inflammatory Effects of Epigallocatechin 3-Gallate (EGCG) in LPS-Activated BV-2 Microglia Cells

Chronic neuroinflammation is associated with many neurodegenerative diseases, such as Alzheimer's. Microglia are the brain's primary immune cells, and when activated, they release various proinflammatory cytokines. Several natural compounds with anti-inflammatory and antioxidant properties, such as epigallocatechin 3-gallate (EGCG), may provide a promising strategy for inflammation-related neurodegenerative diseases involving activated microglia cells. The objective of the current study was to examine the molecular targets underlying the anti-inflammatory effects of EGCG in activated microglia cells. BV-2 microglia cells were grown, stimulated, and treated with EGCG. Cytotoxicity and nitric oxide (NO) production were evaluated. Immunoassay, PCR array, and WES™ Technology were utilized to evaluate inflammatory, neuroprotective modulators as well as signaling pathways involved in the mechanistic action of neuroinflammation. Our findings showed that EGCG significantly inhibited proinflammatory mediator NO production in LPS-stimulated BV-2 microglia cells. In addition, ELISA analysis revealed that EGCG significantly decreases the release of proinflammatory cytokine IL-6 while it increases the release of TNF-α. PCR array analysis showed that EGCG downregulated MIF, CCL-2, and CSF2. It also upregulated IL-3, IL-11, and TNFS10. Furthermore, the analysis of inflammatory signaling pathways showed that EGCG significantly downregulated mRNA expression of mTOR, NF-κB2, STAT1, Akt3, CCL5, and SMAD3 while significantly upregulating the expression of mRNA of Ins2, Pld2, A20/TNFAIP3, and GAB1. Additionally, EGCG reduced the relative protein expression of NF-κB2, mTOR, and Akt3. These findings suggest that EGCG may be used for its anti-inflammatory effects to prevent neurodegenerative diseases.

EGCG Induces Pro-inflammatory Response in Macrophages to Prevent Bacterial Infection through the 67LR/p38/JNK Signaling Pathway

Extensive studies focused on the therapeutic efficacy of epigallocatechin-3-gallate (EGCG) against bacterial infection. However, little is known about its prophylactic efficacy against bacterial infection. Herein, we found that EGCG showed an effective prophylactic efficacy against bacterial infection with a broad spectrum, including Gram-negative, Gram-positive, and drug-resistant bacteria. Pretreatment with EGCG through intraperitoneal injection, intravenous injection, or intragastric administration significantly reduced the bacterial load, inflammatory response, and mortality in mouse abdominal infection models induced by bacterial inoculation or cecal ligation and puncture. Pretreatment with EGCG by intraperitoneal injection significantly increased the numbers of neutrophils and monocytes/macrophages in the abdominal cavity and peripheral blood of mice, and depletion of neutrophils and monocytes/macrophages by specific antibodies or chemical drugs obviously increased the bacterial load in mice. Of note, EGCG did not directly induce neutrophil and macrophage migration, and it just induced phagocyte migration in the presence of macrophages in a co-cultured system, implying that EGCG-induced phagocyte migration relies on its immunoregulatory effects on macrophages. EGCG markedly induced the production of cytokines and chemokines in macrophages and mouse peritoneal lavage, including tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1β), IL-6, CXC chemokine ligands 1 and 2 (CXCL1 and 2), and monocyte chemotactic protein-1 (MCP-1). EGCG significantly induced the phosphorylation of p38 and JNK mitogen-activated protein kinases (MAPKs) in macrophages, and inhibition of p38 and JNK MAPKs markedly reduced EGCG-induced chemokine and cytokine production. Anti-67-kDa laminin receptor (67LR) antibody treatment significantly reduced EGCG-induced chemokine production and p38 and JNK phosphorylation in macrophages. Together, EGCG showed an obvious prophylactic efficacy against bacterial infection by inducing a pro-inflammatory response in macrophages through the 67LR/p38/JNK signaling pathway, supporting the further development of EGCG as a potent prophylaxis for bacterial infection and providing new clues to understand the healthcare function of green tea.