Role of Toll-Like Receptor 2 in Regulation of T-Helper Immune Response in Chronic Obstructive Pulmonary Disease

Targeted V-type peptide-decorated nanoparticles prevent colitis by inhibiting endosomal TLR signaling and modulating intestinal macrophage polarization

Inflammatory bowel disease (IBD) has become a serious and challenging health problem globally without curative medical treatments. Mounting evidence suggests that intestinal macrophages and their phenotypes are key players in the pathogenesis of IBD. Modulating the phenotypes and functions of intestinal macrophages through targeted interventions could be a promising approach to manage detrimental gut inflammation in IBD. In this study, we rationally design and fabricate a novel class of V-type peptide-decorated nanoparticles, VP-NP, with potent anti-inflammatory activity. Such a design allows two functional motifs FFD in a single peptide molecule to enhance the bioactivity of the nanoparticles. As expected, VP-NP exhibits a strong inhibitory activity on endosomal Toll-like receptor (TLR) signaling. Surprisingly, VP-NP can inhibit M1 polarization while facilitating M2 polarization in mouse bone marrow-derived macrophages through regulating the key transcription factors NF-κB, STAT1 and PPAR-γ. Mechanistically, VP-NP is internalized by macrophages in the endosomes, where it blocks endosomal acidification to inhibit endosomal TLR signaling; the transcriptomic analysis reveals that VP-NP potently down-regulates many genes in TLR, NF-κB, JAK-STAT, and cytokine/chemokine signaling pathways associated with inflammatory responses. In a colitis mouse model, the intraperitoneally administered VP-NP effectively alleviates the disease activities by decreasing colon inflammation and injuries, pro-inflammatory cytokine production, and myeloid cell infiltration in the gut. Furthermore, VP-NP primarily targets intestinal macrophages and alters their phenotypes from inflammatory M1-type toward the anti-inflammatory M2-type. This study provides a new nanotherapeutic strategy to specifically regulate macrophage activation and phenotypes through a dual mechanism to control gut inflammation, which may augment current clinical treatments for IBD.

Phenotypes of regulatory T cells in different stages of COPD

BACKGROUND

Previous studies have shown that failure to control inflammatory processes mediated by regulatory T (Treg) cells contributes to chronic obstructive pulmonary disease (COPD) development and progression. The activity of Treg cells depends on their phenotypic characteristics: resting Treg (rTreg, CD3+CD4+CD25+FOXP3+CD25++CD45RA+) and activated Treg (aTreg, CD3+CD4+CD25+FOXP3+CD25+++CD45RA-) cells exhibit immunosuppressive activity, while cytokine-secreting T cells (FrIII, CD3+CD4+CD25+FOXP3+CD25++CD45RA-) exhibit proinflammatory activity. Previous findings have shown an increased density of cytokine-secreting T cells in COPD patients experiencing exacerbation. However, the methods for evaluating COPD under stable conditions are lacking.

AIM

To evaluate Treg cell phenotypes in patients with different stages of COPD under stable conditions.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from non-obstructed smokers and ex-smokers (NOS group, n = 19) and COPD patients at different stages (COPD I-II group, n = 25; COPD III-IV group, n = 25). The phenotypic characteristics of Treg cells and Th17 cells and their respective intracellular cytokines were analyzed by flow cytometry.

RESULTS

Both obstructed groups showed an increase in the proportion of rTregs, while the COPD III-IV group showed additional increases in total Treg and Th17 cells and in IL-10+ cells. There was an increase in proinflammatory mediators (CD3+CD4+IL-17+ cells; CD3+CD4+RORγt+ cells) in the COPD I-II group. In contrast, the NOS group demonstrated high proportions of proinflammatory Treg cells and proinflammatory CD8+ T cells (CD3+CD8+IL-17+).

CONCLUSION

Despite the increase in both total Treg cells and the rTreg phenotype from the early stages of COPD, there was a decrease in cells expressing IL-10, suggesting a failure in controlling the inflammatory process. These events precede the progression of the inflammatory process mediated by Th17 cells.

Exploring the mechanism of Lianhuaqingwen (LHQW) in treating chronic bronchitis based on network pharmacology and experimental validation

BACKGROUND

Lianhuaqingwen (LHQW) has been used in the treatment of chronic bronchitis, but the precise mechanism through which LHQW exhibits its anti-inflammatory effects in this context is not yet fully understood. The aim of this study was to investigate the active ingredients and signaling pathways responsible for LHQW's effectiveness in managing chronic bronchitis.

METHODS

The research leveraged the TCMSP database to determine the active compounds and drug targets of LHQW. In parallel, the GeneCards, DrugBank, and PharmGkb databases were used to uncover targets pertinent to chronic bronchitis. To discern the potential mechanisms by which LHQW's active ingredients might treat chronic bronchitis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. Network pharmacology facilitated the construction of a drug-active ingredient-disease target network, aiding in forecasting the core targets for chronic bronchitis treatment by LHQW. Subsequently, molecular docking techniques alongside in vitro experiments were applied to confirm the interactions between the active ingredients and the primary targets.

RESULTS

A total of 157 active ingredients, 225 potential drug targets, and 594 bronchitis-related targets were derived from various databases. Following this, 76 potential gene targets were pinpointed by integrating drug and related targets. GO and KEGG enrichment analyses were employed to identify key pathways involved in LHQW's mechanism for treating chronic bronchitis. By constructing a protein-protein interaction (PPI) network for the 76 potential gene targets, four core targets (TNF, IL6, IFNG, and STAT3) were identified as primarily involved in responses to lipopolysaccharide, the TNF pathway, and the JAK-STAT pathway. Molecular docking results revealed a favorable affinity between multiple active ingredients of LHQW and the four core targets, suggesting that the therapeutic effects are mediated through the inhibition of inflammatory responses and signaling pathways. Interestingly, quercetin, an active ingredient of LHQW, was observed to bind to all four core targets simultaneously. Furthermore, cell experiment and western blot analysis indicated that both LHQW and quercetin exhibit anti-inflammatory effects by targeting the four core proteins and the JAK-STAT pathways.

CONCLUSION

This research emphasizes the diverse active ingredients, targets, channels, and pathways of LHQW in the treatment of chronic bronchitis, providing important perspectives for the creation of novel therapeutic drugs and clinical uses.

Data driven analysis reveals prognostic genes and immunological targets in human sepsis-associated acute kidney injury

BACKGROUND

The molecular mechanism of sepsis-associated acute kidney injury (SA-AKI) is unclear. We analyzed co-differentially expressed genes (co-DEGs) to elucidate the underlying mechanism and intervention targets of SA-AKI.

METHODS

The microarray datasets GSE65682, GSE30718, and GSE174220 were downloaded from the Gene Expression Omnibus (GEO) database. We identified the co-DEGs and constructed a gene co-expression network to screen the hub genes. We analyzed immune correlations and disease correlations and performed functional annotation of the hub genes. We also performed single-cell and microenvironment analyses and investigated the enrichment pathways and the main transcription factors. Finally, we conducted a correlation analysis to evaluate the role of the hub genes.

RESULTS

Interleukin 32 (IL32) was identified as the hub gene in SA-AKI, and the main enriched signaling pathways were associated with hemopoiesis, cellular response to cytokine stimulus, inflammatory response, and regulation of kidney development. Additionally, IL32 was significantly associated with mortality in SA-AKI patients. Monocytes, macrophages, T cells, and NK cells were closely related to IL32 and were involved in the immune microenvironment in SA-AKI patients. IL32 expression increased significantly in the kidney of septic mouse. Toll-like receptor 2 (TLR2) was significantly and negatively correlated with IL32.

CONCLUSION

IL32 is the key gene involved in SA-AKI and is significantly associated with prognosis. TLR2 and relevant immune cells are closely related to key genes.

Associations Of Fatty Acid Composition In Leukocyte Membranes With Systemic Inflammation In Chronic Obstructive Pulmonary Disease Progression

Background — The development of systemic inflammation is a key pathogenetic mechanism in progression of chronic obstructive pulmonary disease (COPD). Fatty acids (FAs) and their oxidized derivatives serve as essential regulators of inflammation. The relationship between systemic inflammation and FA metabolism in COPD is poorly understood. In our research, we focused on examining the FA composition of the leukocyte membrane in COPD and the FA metabolism in association with systemic inflammation. Objective — We examined 137 patients with mild, moderate, or severe COPD. The control group comprised 32 healthy non-smokers. Methods — Blood cytokines and immune cell subpopulations were evaluated by flow cytometry. The FA composition of the leukocyte membranes was analyzed by gas chromatography. The concentrations of eicosanoids (thromboxane B2 (TXB2), leukotriene B4 (LTB4)) in plasma were measured by ELISA. Results — Our results implied systemic inflammation in all patients with COPD. The analysis of the FA composition of leukocyte membrane demonstrated increased level of saturated FAs and n-6 polyunsaturated fatty acids (PUFAs), along with reduced levels of monounsaturated FAs and n-3 PUFAs, in patients with COPD. The TXB2 and LTB4 content was increasing in COPD patients. We established a significant correlation with n-6 PUFAs, immune cells, and cytokines, which was indicative of an important role of FAs in the progress of systemic inflammation in COPD. Conclusion — Thus, FA modification of immune cells in patients with chronic pathologies of the bronchopulmonary system leads not only to disruption of the cell membrane structure, but also to the pathology of immune response regulation, and contributes to the development of the inflammatory process. The latter is a decisive factor in the pathogenesis of COPD.