USP18 mitigates lipopolysaccharide-induced oxidative stress and inflammation in human pulmonary microvascular endothelial cells through the TLR4/NF-κB/ROS signaling

Esculin alleviates lipopolysaccharide (LPS)-induced pneumonia by regulating the USP7/MAPK14 axis

Pneumonia is a serious and life-threatening lung inflammation with high morbidity and mortality. Accumulating evidence has suggested that esculin, a derivative of coumarin, possesses potent anti-inflammatory effects. This study is designed to explore the pharma role and underlying mechanism of esculin against lipopolysaccharides (LPS)-induced pneumonia. TC-1 cells were stimulated by LPS to mimic the inflammatory injury model in vitro. Cell viability, proliferation, and apoptosis were determined using MTT assay, 5-ethynyl-2'-deoxyuridine assay, and flow cytometry. Interleukin-1β and tumor necrosis factor α levels were analyzed using an enzyme-linked immunosorbent assay. Reactive oxygen species and superoxide dismutase were examined using special assay kits. Macrophage polarization was detected using flow cytometry. Mitogen-activated protein kinase 14 (MAPK14) level was detected by real-time quantitative polymerase chain reaction. MAPK14 and ubiquitin-specific protease 7 (USP7) protein levels were determined using western blot assay. After Ubibrowser database prediction, the interaction between USP7 and MAPK14 was verified using a Co-immunoprecipitation assay. The biological role of esculin was verified in LPS-challenged ALI mice in vivo. Here, we found that esculin significantly relieved LPS-induced TC-1 cell proliferation inhibition, and apoptosis, inflammatory response, oxidative stress, and M1-type macrophage polarization promotion. MAPK14 and USP7 expressions were enhanced in LPS-treated TC-1 cells, which was partly abolished by esculin treatment. Overexpressing MAPK14 attenuated the repression of esculin on LPS-triggered TC-1 cell injury. At the molecular level, USP7 interacted with MAPK14 and maintained its stability by removing ubiquitin. Moreover, esculin repressed the progression of pneumonia in vivo by regulating MAPK14. Taken together, esculin exposure could mitigate LPS-induced TC-1 cell injury partly by targeting the USP7/MAPK14 axis, providing a better understanding of the role of esculin in the anti-inflammatory therapeutics for pneumonia.

Exploring the Anti-Inflammatory Effect of Tryptanthrin by Regulating TLR4/MyD88/ROS/NF-κB, JAK/STAT3, and Keap1/Nrf2 Signaling Pathways

Tryptanthrin (TRYP) is the main active ingredient in Indigo Naturalis. Studies have shown that TRYP had excellent anti-inflammatory activity, but its specific mechanism has been unclear. In this work, the differentially expressed proteins resulting from TRYP intervention in LPS-stimulated RAW264.7 cells were obtained based on tandem mass tag proteomics technology. The anti-inflammatory mechanism of TRYP was further validated by a combination of experiments using the LPS-induced RAW264.7 cell model in vitro and the DSS-induced UC mouse model (free drinking 2.5% DSS) in vivo. The results demonstrated that TRYP could inhibit levels of NO, IL-6, and TNF-α in LPS-induced RAW264.7 cells. Twelve differential proteins were screened out. And the results indicated that TRYP could inhibit upregulated levels of gp91phox, p22phox, FcεRIγ, IKKα/β, and p-IκBα and reduce ROS levels in vitro. Besides, after TRYP treatment, the health conditions of colitis mice were all improved. Furthermore, TRYP inhibited the activation of JAK/STAT3, nuclear translocation of NF-κB p65, and promoted the nuclear expression of Nrf2 in vitro and in vivo. This work preliminarily indicated that TRYP might suppress the TLR4/MyD88/ROS/NF-κB and JAK/STAT3 signaling pathways to exert anti-inflammatory effects. Additionally, TRYP could achieve antioxidant effects by regulating the Keap1/Nrf2 signaling pathway.

Bacillus cereus CwpFM induces colonic tissue damage and inflammatory responses through oxidative stress and the NLRP3/NF-κB pathway

Bacillus cereus (B. cereus) from cow milk poses a threat to public health, causing food poisoning and gastrointestinal disorders in humans. We identified CwpFM, an enterotoxin from B. cereus, caused oxidative stress and inflammatory responses in mouse colon and colonic epithelial cells. Colon proteomics revealed that CwpFM elevated proteins associated with inflammation and oxidative stress. Notably, CwpFM induced activation of the NLRP3/NF-κB signaling, but suppressed antioxidant NFE2L2/HO-1 expression in the intestine and epithelial cells. Consistently, CwpFM exposure led to cytotoxicity and ROS accumulation in Caco-2 cells in a dose-dependent manner. Further, NAC (ROS inhibitor) treatment abolished NLRP3/NF-κB activation due to CwpFM. Moreover, overexpression of Nfe2l2 or activation of NFE2L2 by NK-252 reduced ROS production and inhibited activation of the NLRP3/NF-κB pathway. Inhibition of NF-κB by ADPC and/or suppression of NLRP3 by MCC950 attenuated CwpFM-induced inflammatory responses in Caco-2 cells. Collectively, CwpFM induced oxidative stress and NLRP3/NF-κB activation by inhibiting the NFE2L2/HO-1 signaling and ROS accumulation, leading to the development of intestinal inflammation. Our data elucidate the role of oxidative stress and innate immunity in CwpFM enterotoxicity and contribute to developing diagnostic and therapeutic products for B. cereus-related food safety issues.

Cadmium promoted LPS-induced inflammation through TLR4/IκBα/NFκ-B signaling by increasing ROS-mediated incomplete autophagy

Cadmium (Cd) exposure is considered as non-infectious stressor to human and animal health. Recent studies suggest that the immunotoxicity of low dose Cd is not directly apparent, but disrupts the immune responses when infected with some bacteria or virus. But how Cd alters the adaptive immunity organ and cells remains unclear. In this study, we applied lipopolysaccharide (LPS, infectious stressor) to induced inflammation in spleen tissues and T cells, and investigated the effects after Cd exposure and the underlying mechanism. Cd exposure promoted LPS-induced the expressions of the inflammatory factors, induced abnormal initiation of autophagy, but blocked autophagic flux. The effects Cd exposure under LPS activation were reversed by the autophagy promoter Rapamycin. Under LPS activation conditions, Cd also induced oxidative stress by increasing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and reducing total antioxidant capacity (T-AOC) activity. The increased superoxide dismutase (SOD) activity after Cd exposure might be a negative feedback or passive adaptive regulation of oxidative stress. Cd-increased autophagic flux inhibition and TNF-α expression were reversed by ROS scavenger α-tocopherol (TCP). Furthermore, under LPS activation condition, Cd promoted activation of toll-like receptor 4 (TLR4)/IκBα/NFκ-B signaling pathway and increased TLR4 protein stability, which were abolished by the pretreatment of Rapamycin. The present study confirmed that, by increasing ROS-mediated inhibiting autophagic degradation of TLR4, Cd promoted LPS-induced inflammation in spleen T cells. This study identified the mechanism of autophagy in Cd-aggravated immunotoxicity under infectious stress, which could arouse public attention to synergistic toxicity of Cd and bacterial or virus infection.

USP18 Curbs the Progression of Metabolic Hypertension by Suppressing JAK/STAT Pathway

Hypertension is a pathological state of the metabolic syndrome that increases the risk of cardiovascular disease. Managing hypertension is challenging, and we aimed to identify the pathogenic factors and discern therapeutic targets for metabolic hypertension (MHR). An MHR rat model was established with the combined treatment of a high-sugar, high-fat diet and ethanol. Histopathological observations were performed using hematoxylin-eosin and Sirius Red staining. Transcriptome sequencing was performed to screen differentially expressed genes. The role of ubiquitin-specific protease 18 (USP18) in the proliferation, apoptosis, and oxidative stress of HUVECs was explored using Cell Counting Kit-8, flow cytometry, and enzyme-linked immunosorbent assays. Moreover, USP18 downstream signaling pathways in MHR were screened, and the effects of USP18 on these signaling pathways were investigated by western blotting. In the MHR model, total cholesterol and low-density lipoprotein levels increased, while high-density lipoprotein levels decreased. Moreover, high vessel thickness and percentage of collagen were noted along with increased malondialdehyde, decreased superoxide dismutase and catalase levels. The staining results showed that the MHR model exhibited an irregular aortic intima and disordered smooth muscle cells. There were 78 differentially expressed genes in the MHR model, and seven hub genes, including USP18, were identified. USP18 overexpression facilitated proliferation and reduced apoptosis and oxidative stress in HUVECs treated with Ang in vitro. In addition, the JAK/STAT pathway was identified as a USP18 downstream signaling pathway, and USP18 overexpression inhibited the expression of JAK/STAT pathway-related proteins. Conclusively, USP18 restrained MHR progression by promoting cell proliferation, reversing apoptosis and oxidative stress, and suppressing the JAK/STAT pathway.

Global research progress of endothelial cells and ALI/ARDS: a bibliometric analysis

Background

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe respiratory conditions with complex pathogenesis, in which endothelial cells (ECs) play a key role. Despite numerous studies on ALI/ARDS and ECs, a bibliometric analysis focusing on the field is lacking. This study aims to fill this gap by employing bibliometric techniques, offering an overarching perspective on the current research landscape, major contributors, and emerging trends within the field of ALI/ARDS and ECs.

Methods

Leveraging the Web of Science Core Collection (WoSCC) database, we conducted a comprehensive search for literature relevant to ALI/ARDS and ECs. Utilizing Python, VOSviewer, and CiteSpace, we performed a bibliometric analysis on the corpus of publications within this field.

Results

This study analyzed 972 articles from 978 research institutions across 40 countries or regions, with a total of 5,277 authors contributing. These papers have been published in 323 different journals, spanning 62 distinct research areas. The first articles in this field were published in 2011, and there has been a general upward trend in annual publications since. The United States, Germany, and China are the principal contributors, with Joe G. N. Garcia from the University of Arizona identified as the leading authority in this field. American Journal of Physiology-Lung Cellular and Molecular Physiology has the highest publication count, while Frontiers in Immunology has been increasingly focusing on this field in recent years. "Cell Biology" stands as the most prolific research area within the field. Finally, this study identifies endothelial glycocalyx, oxidative stress, pyroptosis, TLRs, NF-κB, and NLRP3 as key terms representing research hotspots and emerging frontiers in this field.

Conclusion

This bibliometric analysis provides a comprehensive overview of the research landscape surrounding ALI/ARDS and ECs. It reveals an increasing academic focus on ALI/ARDS and ECs, particularly in the United States, Germany, and China. Our analysis also identifies several emerging trends and research hotspots, such as endothelial glycocalyx, oxidative stress, and pyroptosis, indicating directions for future research. The findings can guide scholars, clinicians, and policymakers in targeting research gaps and setting priorities to advance the field.

Macrophage Tim-3 maintains intestinal homeostasis in DSS-induced colitis by suppressing neutrophil necroptosis

T-cell immunoglobulin domain and mucin domain-3 (Tim-3) is a versatile immunomodulator that protects against intestinal inflammation. Necroptosis is a type of cell death that regulates intestinal homeostasis and inflammation. The mechanism(s) underlying the protective role of macrophage Tim-3 in intestinal inflammation is unclear; thus, we investigated whether specific Tim-3 knockdown in macrophages drives intestinal inflammation via necroptosis. Tim-3 protein and mRNA expression were assessed via double immunofluorescence staining and single-cell RNA sequencing (sc-RNA seq), respectively, in the colonic tissues of patients with inflammatory bowel disease (IBD) and healthy controls. Macrophage-specific Tim3-knockout (Tim-3M-KO) mice were generated to explore the function and mechanism of Tim-3 in dextran sodium sulfate (DSS)-induced colitis. Necroptosis was blocked by pharmacological inhibitors of receptor-interacting protein kinase (RIP)1, RIP3, and reactive oxygen species (ROS). Additionally, in vitro experiments were performed to assess the mechanisms of neutrophil necroptosis induced by Tim-3 knockdown macrophages. Although Tim-3 is relatively inactive in macrophages during colon homeostasis, it is highly active during colitis. Compared to those in controls, Tim-3M-KO mice showed increased susceptibility to colitis, higher colitis scores, and increased pro-inflammatory mediator expression. Following the administration of RIP1/RIP3 or ROS inhibitors, a significant reduction in intestinal inflammation symptoms was observed in DSS-treated Tim-3M-KO mice. Further analysis indicated the TLR4/NF-κB pathway in Tim-3 knockdown macrophages mediates the TNF-α-induced necroptosis pathway in neutrophils. Macrophage Tim-3 regulates neutrophil necroptosis via intracellular ROS signaling. Tim-3 knockdown macrophages can recruit neutrophils and induce neutrophil necroptosis, thereby damaging the intestinal mucosal barrier and triggering a vicious cycle in the development of colitis. Our results demonstrate a protective role of macrophage Tim-3 in maintaining gut homeostasis by inhibiting neutrophil necroptosis and provide novel insights into the pathogenesis of IBD.

Transcriptome sequencing promotes insights on the molecular mechanism of SKP-SC-EVs mitigating denervation-induced muscle atrophy

BACKGROUND

Complex pathophysiological changes accompany denervation-induced skeletal muscle atrophy, but no effective treatment strategies exist. Our previous study indicated that extracellular vesicles derived from skin-derived precursors-derived Schwann cells (SKP-SC-EVs) can effectively mitigate denervation-induced muscle atrophy. However, the specific molecular mechanism remains unclear.

METHODS AND RESULTS

In this study, we used bioinformatics methods to scrutinize the impact of SKP-SC-EVs on gene expression in denervation-induced skeletal muscle atrophy. We found that SKP-SC-EVs altered the expression of 358 genes in denervated skeletal muscles. The differentially expressed genes were predominantly participated in biological processes, including cell cycle, inflammation, immunity, and adhesion, and signaling pathways, such as FoxO and PI3K.Using the Molecular Complex Detection (MCODE) plugin, we identified the two clusters with the highest score: cluster 1 comprised 37 genes, and Cluster 2 consisted of 24 genes. Then, fifty hub genes were identified using CytoHubba. The intersection of Hub genes and genes obtained by MCODE showed that all 23 genes related to the cell cycle in Cluster 1 were hub genes, and 5 genes in Cluster 2 were hub genes and associated with inflammation.

CONCLUSIONS

Overall, the differentially expressed genes in denervated skeletal muscle following SKP-SC-EVs treatment are primarily linked to the cell cycle and inflammation. Consequently, promoting proliferation and inhibiting inflammation may be the critical process in which SKP-SC-EVs delay denervation-induced muscle atrophy. Our findings contribute to a better understanding of the molecular mechanism of SKP-SC-EVs delaying denervation-induced muscle atrophy, offering a promising new avenue for muscle atrophy treatment.

Asprosin Exacerbates Endothelium Inflammation Induced by Hyperlipidemia Through Activating IKKβ-NF-κBp65 Pathway

Vascular endothelium dysfunction caused by endothelium inflammation is a trigger of numerous cardiovascular diseases. Vascular endothelium inflammation often occurs in patients with obesity. Asprosin (ASP) derived from white adipose tissue plays important roles in maintaining glucose homeostasis. However, effect of ASP on the vascular endothelium inflammation induced by hyperlipidemia and its underlying mechanism remains largely unclear. In this study, models of vascular endothelium inflammation were established to investigate the effect of ASP on the endothelium inflammation both in vivo and in vitro. Our data in vivo showed that recombinant ASP or high-fat diet (HFD) significantly increased the circulating levels of IL-6 and TNF-α and enhanced the adhesion of macrophages to endothelia characterized by the expression increase of CD68, ICAM-1, and VCAM-1 in rats. However, neutralization of ASP with an ASP specific antibody (AASP) significantly antagonized the changes induced by HFD. Similarly, our data in vitro also showed that ASP treatment elevated the expressions of IL-6, TNF-α, and ICAM-1 as well as VCAM-1. More important, our data revealed that the pro-inflammation effect of ASP was achieved by activating the IKKβ-NF-κBp65 pathway other than the oxidative stress pathway both in vivo and in vitro. In conclusion, our results demonstrate that ASP is a pro-inflammation player in the obesity-associated endothelium dysfunction. The findings would provide a novel target for the prevention and treatment of obesity-related cardiovascular diseases.

Comprehensive Analysis of Universal Stress Protein Family Genes and Their Expression in Fusarium oxysporum Response of Populus davidiana × P. alba var. pyramidalis Louche Based on the Transcriptome

Universal stress proteins (USPs) are typical stress-inducible proteins that function directly in a variety of biotic or abiotic stresses and effectively protect plants from complex, adverse environments. However, the expression patterns of USP genes under pathogen stress and their molecular mechanisms in stress resistance have not been reported in detail. In this study, 46 USP genes were identified from Populus trichocarpa (PtrUSPs), and their biological characteristics were comprehensively analyzed based on phylogeny, physicochemical properties of proteins, and gene structures. The promoter regions of PtrUSPs contain a variety of cis-acting elements related to hormone and stress response. The results of a collinearity analysis showed that PtsrUSPs were highly conserved with homologous genes from four other representative species (Arabidopsis thaliana, Eucalyptus grandis, Glycine max, and Solanum lycopersicum). Furthermore, RNA-Seq analysis showed that the expression of 46 USPs from P. davidiana × P. alba var. pyramidalis Louche (PdpapUSPs) was significantly induced by Fusarium oxysporum. The co-expression network and gene ontology analysis of PtrUSPs showed that they participated in the response to stress and response to stimulus through precise coordination. The results of this paper systematically revealed the biological characteristics of PtrUSPs and the characteristics of their response to F. oxysporum stress, which will lay a theoretical foundation for improving genetic traits and the breeding of poplar disease-resistant varieties in subsequent studies.

Multiple anti-inflammatory mechanisms of Zedoary Turmeric Oil Injection against lipopolysaccharides-induced acute lung injury in rats elucidated by network pharmacology combined with transcriptomics

BACKGROUND

Prospects for the drug treatment of acute lung injury (ALI) is unpromising. Managing inflammation can prevent ALI from progressing and minimize further deterioration. Zedoary turmeric oil injection (ZTOI), a patented traditional Chinese medicine (TCM) that has been used against ALI, has shown significant anti-inflammatory effects. However, the mechanisms underlying these effects remain unclear.

PURPOSE

Elucidate the anti-inflammatory mechanism by which ZTOI acts against ALI in rats using an ingredients-targets-pathways (I-T-P) interaction network.

STUDY DESIGN AND METHODS

The key ingredients of ZTOI were characterized using UPLC-MS/MS combined with literature mining. The target profiles of each ingredient were established using drug-target databases. The anti-inflammatory activity of ZTOI against lipopolysaccharides (LPS)-induced rat ALI was validated using histopathology and inflammatory factor assessments. The therapeutic targets of ZTOI were screened by integrating transcriptomic results of lung tissues with protein-protein interaction (PPI) expansion. Using KEGG pathway enrichment, an I-T-P network was established to determine the essential interactions among ingredients, targets, and pathways of ZTOI against lung inflammation in ALI. Molecular docking and immunofluorescence staining were utilized to confirm the accuracy of the I-T-P network.

RESULTS

A total of 11 sesquiterpenes, whose target profiles may characterize the potential function of ZTOI, were identified as key ingredients. In the ALI rat model, ZTOI can alleviate lung inflammation by decreasing the levels of C-reactive protein, interleukin-6, interleukin-1β, and tumor necrosis factor α both in serum and lung tissues. Based on our biological samples, transcriptomics, PPI network expansion, and KEGG pathway enrichment, 11 ingredients, 174 targets, and 8 signaling pathways were linked in the I-T-P networks. From these results, ZTOI could be inferred to exert multiple anti-inflammatory effects against ALI through Toll-like receptor, NF-kappa B, RIG-I-like receptor, TNF, NOD-like receptor, IL-17, MAPK, and the Toll and Imd signaling pathways. In addition, two significantly regulated targets in the transcriptome, Usp18 and Map3k7, could be the essential anti-inflammatory targets of ZTOI.

CONCLUSION

By integrating network pharmacology with ingredient identification and transcriptomics, we show the multiple anti-inflammatory mechanisms by which ZTOI acts against ALI on an I-T-P level. This work also provides a methodological reference for related research into TCM.

Knockdown of triggering receptor expressed on myeloid cells 1 (TREM1) inhibits endoplasmic reticulum stress and reduces extracellular matrix degradation and the apoptosis of human nucleus pulposus cells

According to the linear model of microarray data analysis, triggering receptor expressed on myeloid cells 1 (TREM1) has been shown to have a significantly different expression profile between intervertebral disc degeneration (IDD) samples and associated control samples. The purpose of the present study was to explore the probable role and underlying mechanism of TREM1 in IDD. To accomplish this, an in vitro model of IDD was established by using IL-1β to stimulate human nucleus pulposus cells (NPCs). After the level of TREM1 had been determined, its functions in terms of the viability of the NPCs, extracellular matrix (ECM) degradation, inflammation, apoptosis and endoplasmic reticulum stress (ERS) were assessed. The downstream target of TREM1 was predicted to be Toll-like receptor-4 (TLR-4) and its roles were then studied, incorporating experiments featuring an ERS agonist. IL-1β was found to elevate the level of TREM1 in NPCs. TREM1 knockdown reversed the observed effects of IL-1β on cell viability, ECM degradation, inflammation, apoptosis of NPCs, ERS and TLR4/NF-κB signaling. Subsequently, the TLR4 and ERS agonists were found to reverse the effect of TREM1 knockdown on NPCs, indicating that the TLR4/NF-κB signaling pathway and ERS were responsible for mediating the regulation of TREM1. In conclusion, the present study showed that TREM1 knockdown blocked the TLR4/NF-κB signaling pathway, inhibited ERS and reduced the levels of ECM degradation and apoptosis of NPCs induced by IL-1β.

Glaucocalyxin A alleviates lipopolysaccharide‑induced inflammation and apoptosis in pulmonary microvascular endothelial cells and permeability injury by inhibiting STAT3 signaling

Glaucocalyxin A (GLA), an ent-kauranoid diterpene derived from Rabdosia japonica var. glaucocalyx, possesses antibacterial, anti-oxidative and anti-neuroinflammatory properties. The present study aimed to investigate the potential mechanisms underlying GLA in the pathogenesis of pneumonia. Human pulmonary microvascular endothelial cells (hPMVECs) treated with lipopolysaccharide (LPS) were treated with GLA, followed by the detection of cell viability, inflammation, apoptosis and cell permeability. Furthermore, the protein expression levels of apoptosis- and permeability-associated proteins were determined using western blot analysis. Following treatment with a signal transducer and activator of transcription 3 (STAT3) activator, the protein expression levels of STAT3 and endoplasmic reticulum stress-associated proteins were determined, to confirm whether STAT3 signaling was mediated by GLA. Lastly, the mRNA expression level of inflammatory cytokines, apoptosis and permeability injury were also determined following treatment with a STAT3 activator. The results revealed that GLA ameliorated inflammation, apoptosis and permeability injury in LPS-induced hPMVECs. Following treatment with a STAT3 activator, the therapeutic effects of GLA on LPS-induced hPMVECs were abrogated. In conclusion, GLA alleviated LPS-induced inflammation, apoptosis and permeability injury in hPMVECs by inhibiting STAT3 signaling, which highlighted the potential therapeutic value of GLA in the treatment of pneumonia.