FAK mediates LPS-induced inflammatory lung injury through interacting TAK1 and activating TAK1-NFκB pathway

Noncanonical functions of adhesion proteins in inflammation

Cell adhesion proteins localize to epithelial and endothelial cell membranes to form junctional complexes between neighboring cells or between cells and the underlying basement membrane. The structural and functional integrities of these junctions are critical to establish cell polarity and maintain tissue barrier function, while also facilitating leukocyte migration and adhesion to sites of inflammation. In addition to their adhesive properties, however, junctional proteins can also serve important noncanonical functions in inflammatory signaling and transcriptional regulation. Intriguingly, recent work has unveiled novel roles for cell adhesion proteins as both signaling initiators and downstream targets during inflammation. In this review, we discuss both the traditional functions of junction proteins in cell adhesion and tissue barrier function as well as their noncanonical signaling roles that have been implicated in facilitating diverse inflammatory pathologies.

Defactinib inhibits FAK phosphorylation and regulates psoriasis via attenuating hyperproliferation of keratinocytes

Excessive proliferation of keratinocytes is a crucial pathological risk feature of psoriasis. Focal adhesion kinase (FAK) is a non-receptor protein that primarily regulates cell proliferation and migration. However, the expression and regulatory mechanism of FAK in psoriasis remains unclear. This study aimed to investigate the regulation of FAK in psoriasis and examined the potential impact of FAK inhibitor on psoriasis. A small molecular selective FAK inhibitor, defactinib, was used to evaluate the effect of FAK on psoriasis in in vitro and in vivo functional assays. In our experiments, imiquimod (IMQ)-induced psoriasis mice and human keratinocytes cells were used to study the potential roles and mechanisms of FAK in psoriasis. FAK phosphorylation has been weakly detected in normal intact skin and is markedly elevated upon IMQ treatment. By reducing FAK phosphorylation (p-FAK), defactinib treatment could attenuate psoriasiform inflammation and epidermal hyperplasia in IMQ-treated mice compared with IMQ-induced mice treated with the vehicle. In in vitro studies, resiquimod (R848) increased (p-FAK) and promoted cell proliferation in human keratinocytes cells, while defactinib reversed this effect. Mechanistically, defactinib can alleviate the proliferation via JNK/YB1 pathway in vitro and in vivo. Defactinib significantly attenuates psoriasiform inflammation and epidermal hyperproliferation through the inhibition of the FAK-mediated axis. The downregulation of phosphorylated FAK then suppressed the activation of JNK/YB1 protein signaling pathway in psoriasis. Our work highlights targeting FAK as a potentially effective strategy for the treatment of psoriasis.

Proteomics reveals the pharmacological mechanism of flavonoids from Astragali Complanati Semen in preventing chronic liver injury

BACKGROUND

Total flavonoids from Astragali Complanati Semen (TFACS), the main active ingredients in Astragali Complanati Semen (ACS), have been shown to have a protective effect on chronic liver injury (CLI), but the hepatoprotective targets and signalling pathways involved are unclear.

PURPOSE

The aim of our study was to identify the anti-CLI targets and signalling pathways of TFACS and to comprehensively elucidate its mechanism of action via proteomics analysis combined with in vivo and in vitro experiments.

METHODS

A CLI mouse model was generated via intraperitoneal injection of carbon tetrachloride (CCl4) (CCl4: olive oil = 1:4, 2 ml/kg, twice a week for 6 weeks). The hepatoprotective effect of TFACS was assessed by observing the pathological structure of the liver and analysing indicators of liver function. The key pathways and targets related to the hepatoprotective effect of TFACS were identified via 4D-label-free quantitative proteomics technology and further verified via in vivo indicator validation and in vitro cell experiments.

RESULTS

TFACS administration significantly normalized the histopathological structure and function of the liver, decreased the levels of inflammatory factors and oxidative stress indicators, and reduced the iron staining area and the levels of hepcidin and iron in the liver compared with those in the CLI model. A total of 424 differentially expressed proteins (DEPs) were identified between the TFACS and model groups, and these DEPs were enriched in the focal adhesion, PI3K-Akt, and ferroptosis pathways. Akt1, Pik3ca, NF-κB p65, Itga5, Itgb5, Itga6, Prkca, Fn1, Tfrc, and Vdac3 were identified as key targets of TFACS. TFACS administration significantly reversed the changes in the gene and protein expression of the key targets compared with those in the model group. In addition, TFACS treatment significantly reduced the levels of inflammatory cytokines and inhibited Akt1, NF-κB p65 and FAK activation in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. In an erastin-induced l-O2 ferroptosis cell model, treatment with TFACS normalized the mitochondrial structure, reduced the protein levels of Tfrc and Vdac3, inhibited lipid peroxidation, and reduced the amount of Fe2+ in the mitochondria.

CONCLUSION

TFACS protected against CLI, and its mechanism of action may be related to inhibition of the focal adhesion, PI3K/Akt and ferroptosis signalling pathways.

Foxq1 Promotes Alveolar Epithelial Cell Death through Tle1-mediated Inhibition of the NF-κB Signaling Pathway

Acute lung injury (ALI) is a common respiratory disease characterized by diffuse alveolar injury and interstitial edema, as well as a hyperinflammatory response, lung cell damage, and oxidative stress. Foxq1, a member of the FOX family of transcription factors, is expressed in various tissues, such as the lungs, liver, and kidneys, and contributes to various biological processes, such as stress, metabolism, cell cycle arrest, and aging-related apoptosis. However, the role of Foxq1 in ALI is unknown. We constructed ex vivo and in vivo ALI models by LPS tracheal perfusion of ICR mice and conditioned medium stimulation of injured MLE-12 cells. Foxq1 expression was increased, and its localization was altered, in our ALI model. In normal or injured MLE-12 cells, knockdown of Foxq1 promoted cell survival, and overexpression had the opposite effect. This regulatory effect was likely mediated by Tle1 and the NF-κB/Bcl2/Bax signaling pathway. These data suggest a potential link between Foxq1 and ALI, indicating that Foxq1 can be used as a biomarker for the diagnosis of ALI. Targeted inhibition of Foxq1 expression could promote alveolar epithelial cell survival and may provide a strategy for mitigating ALI.

Injectable hybrid hydrogels enable enhanced combination chemotherapy and roused anti-tumor immunity in the synergistic treatment of pancreatic ductal adenocarcinoma

Chemotherapy and immunotherapy have shown no significant outcome for unresectable pancreatic ductal adenocarcinoma (PDAC). Multi-drug combination therapy has become a consensus in clinical trials to explore how to arouse anti-tumor immunity and meanwhile overcome the poorly tumoricidal effect and the stroma barrier that greatly hinders drug penetration. To address this challenge, a comprehensive strategy is proposed to fully utilize both the ferroptotic vulnerability of PDAC to potently irritate anti-tumor immunity and the desmoplasia-associated focal adhesion kinase (FAK) to wholly improve the immunosuppressive microenvironment via sustained release of drugs in an injectable hydrogel for increasing drug penetration in tumor location and averting systematic toxicity. The injectable hydrogel ED-M@CS/MC is hybridized with micelles loaded with erastin that exclusively induces ferroptosis and a FAK inhibitor defactinib for inhibiting stroma formation, and achieves sustained release of the drugs for up to 12 days. With only a single intratumoral injection, the combination treatment with erastin and defactinib produces further anti-tumor performance both in xenograft and KrasG12D-engineered primary PDAC mice and synergistically promotes the infiltration of CD8+ cytotoxic T cells and the reduction of type II macrophages. The findings may provide a novel promising strategy for the clinical treatment of PDAC.

Clinical effect of perioperative stellate ganglion block on mechanical ventilation and respiratory function of elderly patients with septic shock

BACKGROUND

Here we investigated the effect of a stellate ganglion block on the perioperative mechanical ventilation and postoperative recovery of respiratory function of elderly patients with infectious shock.

METHODS

Thirty-six elderly patients with septic shock who underwent emergency general anesthesia at our hospital were randomly divided into treatment (T) and control (C) groups (n = 18 each). Group T received a preoperative stellate ganglion block, whereas group C received normal saline. Procalcitonin and C-reactive protein levels were compared preoperatively and at 1 and 7 days postoperative. Mean arterial pressure, oxygen saturation, and mean pulmonary artery pressure were measured preoperative and postoperative as well as at 1 and 7 days later. A blood gas analysis was performed preoperatively, at the end of the operation, during extubation, and at 1 and 7 days postoperative. Intubation under general anesthesia, the completion of anesthesia, and spontaneous respiratory recovery involve pulmonary dynamic compliance, plateau pressure, and mechanical ventilation.

RESULTS

General condition did not differ significantly between groups (P > .05). However, mean arterial pressure at the end of surgery and at 1 and 7 days postoperative were significantly higher in group T versus C (P < .05). Furthermore, mean oxygen saturation at the end of surgery and at 1 and 7 days postoperative was significantly lower in group T versus C (P < .05), while procalcitonin and C-reactive protein levels were significantly lower at 1 and 7 days postoperative. Group T had significantly better arterial partial pressure of carbon dioxide, partial pressure of oxygen, and partial pressure of oxygen/fraction of inspired oxygen than group C at the end of surgery, during extubation, and at 1 and 7 days postoperative (P < .05).

CONCLUSION

Group T exhibited superior inflammatory responses and respiratory function. Stellate ganglion block in elderly patients with septic shock reduces inflammation, improves mechanical ventilation perioperatively, and promotes postoperative recovery and respiratory function.

Echinatin attenuates acute lung injury and inflammatory responses via TAK1-MAPK/NF-κB and Keap1-Nrf2-HO-1 signaling pathways in macrophages

Echinatin is an active ingredient in licorice, a traditional Chinese medicine used in the treatment of inflammatory disorders. However, the protective effect and underlying mechanism of echinatin against acute lung injury (ALI) is still unclear. Herein, we aimed to explore echinatin-mediated anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated ALI and its molecular mechanisms in macrophages. In vitro, echinatin markedly decreased the levels of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated murine MH-S alveolar macrophages and RAW264.7 macrophages by suppressing inducible nitric oxide synthase and cyclooxygenase-2 (COX-2) expression. Furthermore, echinatin reduced LPS-induced mRNA expression and release of interleukin-1β (IL-1β) and IL-6 in RAW264.7 cells. Western blotting and CETSA showed that echinatin repressed LPS-induced activation of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways through targeting transforming growth factor-beta-activated kinase 1 (TAK1). Furthermore, echinatin directly interacted with Kelch-like ECH-associated protein 1 (Keap1) and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway to enhance heme oxygenase-1 (HO-1) expression. In vivo, echinatin ameliorated LPS-induced lung inflammatory injury, and reduced production of IL-1β and IL-6. These findings demonstrated that echinatin exerted anti-inflammatory effects in vitro and in vivo, via blocking the TAK1-MAPK/NF-κB pathway and activating the Keap1-Nrf2-HO-1 pathway.

Saikosaponin F ameliorates depression-associated dry eye disease by inhibiting TRIM8-induced TAK1 ubiquitination

AIMS

Saikosaponin F (SsF) is one of the major active ingredients of Radix Bupleuri, an herb widely used in the treatment of depression. Studies have shown that dry eye disease often occurs together with depression. The aim of this study is to investigate whether SsF can improve depression-associated dry eye disease and explore the underlying mechanism.

METHODS

Behavioral test was used to verify the effect of SsF on CUMS-induced depression-like behaviors in mice. Corneal fluorescein staining, phenol red cotton thread test and periodic acid-Schiff (PAS) staining were used to observe the effect of SsF on depression-associated dry eye disease. Western blot (WB) was performed to observe the expression of TAK1 protein and key proteins of NF-κB and MAPK (P38) inflammatory pathways in the hippocampus and cornea. Immunohistochemical staining was used to observe the expression of microglia, and immunoprecipitation was used to observe K63-linked TAK1 ubiquitination. Subsequently, we constructed a viral vector sh-TAK1 to silence TAK1 protein to verify whether SsF exerted its therapeutic effect based on TAK1. The expression of inflammatory factors such as IL-1β, TNF-α and IL-18 in hippocampus and cornea were detected by ELISA. Overexpression of TRIM8 (OE-TRIM8) by viral vector was used to verify whether SsF improved depression-associated dry eye disease based on TRIM8.

RESULTS

SsF treatment significantly improved the depression-like behavior, increased tear production and restored corneal injury in depression-related dry eye model mice. SsF treatment downregulated TAK1 expression and TRIM8-induced K63-linked TAK1 polyubiquitination, while inhibiting the activation of NF-κB and MAPK (P38) inflammatory pathways and microglial expression. In addition, selective inhibition of TAK1 expression ameliorated depression-associated dry eye disease, while overexpression of TRIM8 attenuated the therapeutic effect of SsF on depression-associated dry eye disease.

CONCLUSION

SsF inhibited the polyubiquitination of TAK1 by acting on TRIM8, resulting in the downregulation of TAK1 expression, inhibition of inflammatory response, and improvement of CUMS-induced depression-associated dry eye disease.

Annual review of PROTAC degraders as anticancer agents in 2022

Following nearly two decades of development, significant advancements have been achieved in PROTAC technology. As of the end of 2022, more than 20 drugs have entered clinical trials, with ARV-471 targeting estrogen receptor (ER) showing remarkable progress by entering phase III clinical studies. In 2022, significant progress has been made on multiple targets. The first reversible covalent degrader designed to target the KRASG12C mutant protein, based on cyclopropionamide, has been reported. Additionally, the activity HDCA1 degrader surpassed submicromolar levels during the same year. A novel FEM1B covalent ligand called EN106 was also discovered, expanding the range of available ligands. Furthermore, the first PROTAC drug targeting SOS1 was reported. Additionally, the first-in-class degraders that specifically target BRD4 isoforms (BRD4 L and BRD4 S) have recently been reported, providing a valuable tool for further investigating the biological functions of these isoforms. Lastly, a breakthrough was also achieved with the first degrader targeting both CDK9 and Cyclin T1. In this review, we aimed to update the PROTAC degraders as potential anticancer agents covering articles published in 2022. The design strategies, degradation effects, and anticancer activities were highlighted, which might provide an updated sight to develop novel PROTAC degraders with great potential as anticancer agents as well as favorable drug-like properties.

Targeting thrombospondin-2 retards liver fibrosis by inhibiting TLR4-FAK/TGF-β signaling

Background & Aims

Thrombospondin-2 (THBS2) expression is associated with liver fibrosis regardless of etiology. However, the role of THBS2 in the pathogenesis of liver fibrosis has yet to be elucidated.

Methods

The in vivo effects of silencing Thbs2 in hepatic stellate cells (HSCs) were examined using an adeno-associated virus vector (serotype 6, AAV6) containing short-hairpin RNAs targeting Thbs2, under the regulatory control of cytomegalovirus, U6 or the α-smooth muscle promoter, in mouse models of carbon tetrachloride or methionine-choline deficient (MCD) diet-induced liver fibrosis. Crosstalk between THBS2 and toll-like receptor 4 (TLR4), as well as the cascaded signaling, was systematically investigated using mouse models, primary HSCs, and human HSC cell lines.

Results

THBS2 was predominantly expressed in activated HSCs and dynamically increased with liver fibrosis progression and decreased with regression. Selective interference of Thbs2 in HSCs retarded intrahepatic inflammatory infiltration, steatosis accumulation, and fibrosis progression following carbon tetrachloride challenge or in a dietary model of metabolic dysfunction-associated steatohepatitis. Mechanically, extracellular THBS2, as a dimer, specifically recognized and directly bound to TLR4, activating HSCs by stimulating downstream profibrotic focal adhesion kinase (FAK)/transforming growth factor beta (TGF-β) pathways. Disruption of the THBS2-TLR4-FAK/TGF-β signaling axis notably alleviated HSC activation and liver fibrosis aggravation.

Conclusions

THBS2 plays a crucial role in HSC activation and liver fibrosis progression through TLR4-FAK/TGF-β signaling in an autocrine manner, representing an attractive potential therapeutic target for liver fibrosis.

Impact and implications

Thrombospondin-2 (THBS2) is emerging as a factor closely associated with liver fibrosis regardless of etiology. However, the mechanisms by which THBS2 is involved in liver fibrosis remain unclear. Here, we showed that THBS2 plays a prominent role in the pathogenesis of liver fibrosis by activating the TLR4-TGF-β/FAK signaling axis and hepatic stellate cells in an autocrine manner, providing a potential therapeutic target for the treatment of liver fibrosis.

[Protective effect of FAK inhibitor PF-562271 against human umbilical vein endothelial cell injury induced by aging platelets]

OBJECTIVE

To investigate the protective effect of PF-562271, a FAK inhibitor, against aging platelet-induced injury in human umbilical vein endothelial cells (HUVECs).

METHODS

Cultured HUVECs were treated with vehicle, lipopolysaccharide (LPS), LPS+aging platelets, or LPS+aging platelets+PF-562271. The changes in protein expressions of FAK, pFAK and PECAM-1 in the treated cells were detected using Western blotting and immunofluorescence assay, and the level of reactive oxygen species (ROS) was detected with flow cytometry. The changes of barrier function of the cells were assessed with cell permeability test and transendothelial cell resistance test. RT-qPCR was used to analyze mRNA expressions of inflammatory factors, and pro-inflammatory cytokine levels in the culture supernatants was determined with enzyme-linked immunosorbent assay. Immunofluorescence assay was used to examine the effect of the ROS inhibitor vitamin C on PECAM-1 expression in the cells with different treatments.

RESULTS

Treatment of HUVECs with LPS and aging platelets significantly increased cellular protein expressions of FAK, pFAK and PECAM-1, which were effectively lowered by addition of PF-562271 (P < 0.05). LPS and aged platelets obviously enhanced ROS production in the cells, which was inhibited by the addition of PF-562271 (P < 0.001). PF-562271 significantly alleviated the damage of endothelial cell barrier function of the cells caused by LPS and aging platelets (P < 0.01). The expressions of TNF-α, IL-6 and IL-8 in HUVECs increased significantly after exposure to LPS and aging platelets, and were obviously lowered after treatment with PF-562271 (P < 0.05). Treatment with vitamin C significantly decreased the expression of PECAM-1 protein in the cells (P < 0.01).

CONCLUSION

The FAK inhibitor PF-562271 alleviates endothelial cell damage induced by LPS and aging platelets by lowering cellular oxidative stress levels and reducing inflammatory responses.

Loss of 15-Lipoxygenase in Retinodegenerative RCS Rats

Retinitis pigmentosa (RP) is a retinal degenerative disease associated with a diversity of genetic mutations. In a natural progression study (NPS) evaluating the molecular changes in Royal College of Surgeons (RCS) rats using lipidomic profiling, RNA sequencing, and gene expression analyses, changes associated with retinal degeneration from p21 to p60 were evaluated, where reductions in retinal ALOX15 expression corresponded with disease progression. This important enzyme catalyzes the formation of specialized pro-resolving mediators (SPMs) such as lipoxins (LXs), resolvins (RvDs), and docosapentaenoic acid resolvins (DPA RvDs), where reduced ALOX15 corresponded with reduced SPMs. Retinal DPA RvD2 levels were found to correlate with retinal structural and functional decline. Retinal RNA sequencing comparing p21 with p60 showed an upregulation of microglial inflammatory pathways accompanied by impaired damage-associated molecular pattern (DAMP) clearance pathways. This analysis suggests that ALXR/FPR2 activation can ameliorate disease progression, which was supported by treatment with an LXA4 analog, NAP1051, which was able to promote the upregulation of ALOX12 and ALOX15. This study showed that retinal inflammation from activated microglia and dysregulation of lipid metabolism were central to the pathogenesis of retinal degeneration in RP, where ALXR/FPR2 activation was able to preserve retinal structure and function.

ACE2 improves endothelial cell function and reduces acute lung injury by downregulating FAK expression

Endothelial cell (EC) barrier dysfunction and increased adhesion of immune inflammatory cells to ECs crucially contribute to acute lung injury (ALI). Angiotensin-converting enzyme 2 (ACE2) is an essential regulator of the renin-angiotensin system (RAS) and exerts characteristic vasodilatory and anti-inflammatory effects. SARS-COV-2 infects the lungs by binding to ACE2, which can lead to dysregulation of ACE2 expression, further leading to ALI with predominantly vascular inflammation and eventually to more severe acute respiratory distress syndrome (ARDS). Therefore, restoration of ACE2 expression represents a valuable therapeutic approach for SARS-COV-2-related ALI/ARDS. In this study, we used polyinosinic-polycytidylic acid (Poly(I:C)), a double-stranded RNA analog, to construct a mouse ALI model that mimics virus infection. After Poly(I:C) exposure, ACE2 was downregulated in mouse lung tissues and in cultured ECs. Treatment with DIZE, an ACE2-activating compound, upregulated ACE2 expression and relieved ALI in mice. DIZE also improved barrier function and reduced the number of THP-1 monocytes adhering to cultured ECs. Focal adhesion kinase (FAK) and phosphorylated FAK (p-FAK) levels were increased in lung tissues of ALI mice as well as in Poly(I:C)-treated ECs in vitro. Both DIZE and the FAK inhibitor PF562271 decreased FAK/p-FAK expression in both ALI models, attenuating ALI severity in vivo and increasing barrier function and reducing monocyte adhesion in cultured ECs. Furthermore, in vivo experiments using ANG 1-7 and the MAS inhibitor A779 corroborated that DIZE-mediated ACE2 activation stimulated the activity of the ANG 1-7/MAS axis, which inhibited FAK/p-FAK expression in the mouse lung. These findings provide further evidence that activation of ACE2 in ECs may be a valuable therapeutic strategy for ALI.

Rosavin Alleviates LPS-Induced Acute Lung Injure by Modulating the TLR-4/NF-κB/MAPK Singnaling Pathways

Acute lung injury (ALI) is a serious inflammatory disease with high morbidity and mortality. Rosavin is an anti-inflammatory and antioxidant phenylpropanoid and glucoside, which is isolated from Rhodiola rosea L. However, its potential molecular mechanisms and whether it has protective effects against lipopolysaccharide (LPS)-induced ALI remain to be elucidated. To assess the in vitro anti-inflammatory effects and anti-lung injury activity of rosavin, RAW264.7 and A549 cells were stimulated using 1 μg/mL LPS. Rosavin attenuated LPS-induced activation of the TLR-4/NF-κB signaling pathway in RAW264.7 cells and inhibited LPS-induced release of inflammatory factors in A549 cells. A mouse model of acute lung injury was constructed by intraperitoneal injection of 5 mg/kg LPS to observe the therapeutic effect of rosavin. Transcriptomics analysis and Western blot assays were utilized to verify the molecular mechanism, rosavin (20, 40, and 80 mg/kg) dose-dependently ameliorated histopathological alterations, reduced the levels of inflammatory factors, and inhibited the TLR-4/NF-κB/MAPK signaling pathway and apoptosis activation. Rosavin is a promising therapeutic candidate for acute lung injury by inhibiting the TLR-4/NF-κB/MAPK pathway.

Xuanbai Chengqi Decoction alleviates acute lung injury by inhibiting NLRP3 inflammasome

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a prevalent critical respiratory disorder caused mostly by infection and other factors. However, effective drug therapies are currently lacking. Xuanbai Chengqi Decoction (XCD), a traditional Chinese medicine (TCM) prescription, is commonly employed to treat lung diseases. It has been recommended by Chinese health authorities as one of the TCM prescriptions for COVID-19. Nonetheless, its underlying mechanism for the treatment of ALI has not been fully understood.

AIM OF THE STUDY

The study aims to investigate the therapeutic effect of XCD on lipopolysaccharide (LPS) -induced ALI in mice and explore its anti-inflammatory mechanism involving pyroptosis.

MATERIALS AND METHODS

Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was employed to identify the active compounds of XCD, and quantitative analysis of the main compounds was conducted. Male C57BL/6J mice were given different doses of XCD (4.5 and 9.0 g/kg/day) or dexamethasone (5 mg/kg/day) by oral gavage for 5 consecutive days. Subsequently, ALI was induced by injecting LPS (20 mg/kg) intraperitoneally 2 h after the last administration, and serum and lung tissues were collected 8 h later. J774A.1 cells were pretreated with different doses of XCD (100, 200, 400 μg/ml) for 12 h, then incubated with LPS (1 μg/ml) for 4 h and ATP (1 mM) for 2 h to induce pyroptosis. Supernatant and cells were collected. Moreover, J774A.1 cells were transfected with an NLRP3 overexpression plasmid for 24 h, followed by subsequent experiments with XCD (400 μg/ml). Lung histopathological changes were evaluated using hematoxylin and eosin (HE) staining. To assess the efficacy of XCD on ALI/ARDS, the levels of inflammatory factors, chemokines, and proteins associated with NLRP3 inflammasome signaling pathway were evaluated.

RESULTS

XCD was found to ameliorate lung inflammation injury in ALI mice, and reduce the protein expression of TNF-α, IL-1β, and IL-6 in both mouse serum and J774A.1 cell supernatant. Meanwhile, XCD significantly decreased the mRNA levels of IL-1β, pro-IL-1β, CXCL1, CXCL10, TNF-α, NLRP3, NF-κB P65, and the protein expression of NLRP3, Cleaved-Caspase1, and GSDMD-N in the lung and J774A.1 cells. These effects were consistent with the NLRP3 inhibitor MCC950. Furthermore, overexpression of NLRP3 reversed the anti-inflammatory effect of XCD.

CONCLUSION

The therapeutic mechanism of XCD in ALI treatment may involve alleviating inflammatory responses in lung tissues by inhibiting the activation of the NLRP3 inflammasome-mediated pyroptosis in macrophages.

Analysis of abnormal expression of signaling pathways in PQ-induced acute lung injury in SD rats based on RNA-seq technology

Background: Paraquat (PQ) plays an important role in agricultural production due to its highly effective herbicidal effect. However, it has led to multiple organ failure in those who have been poisoned, with damage most notable in the lungs and ultimately leading to death. Because of little research has been performed at the genetic level, and therefore, the specific genetic changes caused by PQ exposure are unclear.Methods: Paraquat poisoning model was constructed in Sprague Dawley (SD) rats, and SD rats were randomly divided into Control group, paraquat (PQ) poisoning group and Anthrahydroquinone-2,6-disulfonate (AH2QDS) treatment group. Then, the data was screened and quality controlled, compared with reference genes, optimized gene structure, enriched at the gene expression level, and finally, signal pathways with significantly different gene enrichment were screened.Results: This review reports on lung tissues from paraquat-intoxicated Sprague Dawley (SD) rats that were subjected to RNA-seq, the differentially expressed genes were mainly enriched in PI3K-AKT, cGMP-PKG, MAPK, Focal adhesion and other signaling pathways.Conclusion: The signaling pathways enriched with these differentially expressed genes are summarized, and the important mechanisms mediated through these pathways in acute lung injury during paraquat poisoning are outlined to identify important targets for AH2QDS treatment of acute lung injury due to paraquat exposure, information that will be used to support a subsequent in-depth study on the mechanism of PQ action.

Prevotella copri promotes vascular calcification via lipopolysaccharide through activation of NF-κB signaling pathway

Emerging evidence indicates that alteration of gut microbiota plays an important role in chronic kidney disease (CKD)-related vascular calcification (VC). We aimed to investigate the specific gut microbiota and the underlying mechanism involved in CKD-VC. We identified an increased abundance of Prevotella copri (P. copri) in the feces of CKD rats (induced by using 5/6 nephrectomy followed by a high calcium and phosphate diet) with aortic calcification via amplicon sequencing of 16S rRNA genes. In patients with CKD, we further confirmed a positive correlation between abundance of P. copri and aortic calcification scores. Moreover, oral administration of live P. copri aggravated CKD-related VC and osteogenic differentiation of vascular smooth muscle cells in vivo, accompanied by intestinal destruction, enhanced expression of Toll-like receptor-4 (TLR4), and elevated lipopolysaccharide (LPS) levels. In vitro and ex vivo experiments consistently demonstrated that P. copri-derived LPS (Pc-LPS) accelerated high phosphate-induced VC and VSMC osteogenic differentiation. Mechanistically, Pc-LPS bound to TLR4, then activated the nuclear factor κB (NF-κB) and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome signals during VC. Inhibition of NF-κB reduced NLRP3 inflammasome and attenuated Pc-LPS-induced VSMC calcification. Our study clarifies a novel role of P. copri in CKD-related VC, by the mechanisms involving increased inflammation-regulating metabolites including Pc-LPS, and activation of the NF-κB/NLRP3 signaling pathway. These findings highlight P. copri and its-derived LPS as potential therapeutic targets for VC in CKD.

Inhibition of focal adhesion kinase 2 results in a macrophage polarization shift to M2 which attenuates local and systemic inflammation and reduces heterotopic ossification after polysystem extremity trauma

Introduction

Heterotopic ossification (HO) is a complex pathology often observed in combat injured casualties who have sustained severe, high energy polytraumatic extremity injuries. Once HO has developed, prophylactic therapies are limited outside of surgical excision. Tourniquet-induced ischemia injury (IR) exacerbates trauma-mediated musculoskeletal tissue injury, inflammation, osteogenic progenitor cell development and HO formation. Others have shown that focal adhesion kinase-2 (FAK2) plays a key role in regulating early inflammatory signaling events. Therefore, we hypothesized that targeting FAK2 prophylactically would mitigate extremity trauma induced IR inflammation and HO formation.

Methods

We tested whether the continuous infusion of a FAK2 inhibitor (Defactinib, PF-573228; 6.94 µg/kg/min for 14 days) can mitigate ectopic bone formation (HO) using an established blast-related extremity injury model involving femoral fracture, quadriceps crush injury, three hours of tourniquet-induced limb ischemia, and hindlimb amputation through the fracture site. Tissue inflammation, infiltrating cells, osteogenic progenitor cell content were assessed at POD-7. Micro-computed tomography imaging was used to quantify mature HO at POD-56.

Results

In comparison to vehicle control-treated rats, FAK2 administration resulted in no marked wound healing complications or weight loss. FAK2 treatment decreased HO by 43%. At POD-7, marked reductions in tissue proinflammatory gene expression and assayable osteogenic progenitor cells were measured, albeit no significant changes in expression patterns of angiogenic, chondrogenic and osteogenic genes. At the same timepoint, injured tissue from FAK-treated rats had fewer infiltrating cells. Additionally, gene expression analyses of tissue infiltrating cells resulted in a more measurable shift from an M1 inflammatory to an M2 anti-inflammatory macrophage phenotype in the FAK2 inhibitor-treated group.

Discussion

Our findings suggest that FAK2 inhibition may be a novel strategy to dampen trauma-induced inflammation and attenuate HO in patients at high risk as a consequence of severe musculoskeletal polytrauma.

Qinhuo Shanggan oral solution resolves acute lung injury by down-regulating TLR4/NF-κB signaling cascade and inhibiting NLRP3 inflammasome activation

Acute lung injury (ALI) is a common condition, particularly in the COVID-19 pandemic, which is distinguished by sudden onset of respiratory insufficiency with tachypnea, oxygen-refractory cyanosis, reduced lung compliance and diffuse infiltration of pulmonary alveoli. It is well-established that increasing activity of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling axis and the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation are associated with the pathogenesis of ALI. Since ALI poses a huge challenge to human health, it is urgent to tackle this affliction with therapeutic intervention. Qinhuo Shanggan oral solution (QHSG), a traditional Chinese herbal formula, is clinically used for effective medication of various lung diseases including ALI, with the action mechanism obscure. In the present study, with the rat model of lipopolysaccharide (LPS)-induced ALI, QHSG was unveiled to ameliorate ALI by alleviating the pathological features, reversing the alteration in white blood cell profile and impeding the production of inflammatory cytokines through down-regulation of TLR4/NF-κB signaling cascade and inhibition of NLRP3 inflammasome activation. In LPS-stimulated RAW264.7 mouse macrophages, QHSG was discovered to hinder the generation of inflammatory cytokines by lessening TLR4/NF-κB signaling pathway activity and weakening NLRP3 inflammasome activation. Taken together, QHSG may resolve acute lung injury, attributed to its anti-inflammation and immunoregulation by attenuation of TLR4/NF-κB signaling cascade and inhibition of NLRP3 inflammasome activation. Our findings provide a novel insight into the action mechanism of QHSG and lay a mechanistic foundation for therapeutic intervention in acute lung injury with QHSG in clinical practice.

Design, synthesis and anti-inflammatory activity study of lansiumamide analogues for treatment of acute lung injury

Acute lung injury (ALI) is an inflammation-mediated respiratory disease with a high mortality rate. Medications with anti-inflammatory small molecules have been demonstrated in phase I and II clinical trials to considerably reduce the ALI mortality. In this study, two series of lansiumamide analogues were designed, synthesized, and evaluated for anti-inflammatory activity for ALI treatment. We found that compound 8n exhibited the best anti-inflammatory activity through inhibiting LPS-induced expression of the proinflammatory cytokines interleukin-6 (IL-6) and interleukin-1β (IL-1β) in Raw264.7 cells and activating the Nrf2/HO-1 pathway. Furthermore, we discovered in a LPS-induced ALI mice model that compound 8n significantly reduced the infiltration of inflammatory cells into lung tissue to achieve the effect of protecting lung tissues and improving ALI. Additionally, our mice model study revealed that compound 8n had a good expectorant effect. These results consistently support that lansiumamide analogue 8n represents a new class of anti-inflammatory agents with potential as a lead compound for further development into a therapeutic drug for ALI treatment.

Pharmacological inhibition of TAK1 prevents and induces regression of experimental organ fibrosis

Multiorgan fibrosis in systemic sclerosis (SSc) accounts for substantial mortality and lacks effective therapies. Lying at the crossroad of TGF-β and TLR signaling, TGF-β-activated kinase 1 (TAK1) might have a pathogenic role in SSc. We therefore sought to evaluate the TAK1 signaling axis in patients with SSc and to investigate pharmacological TAK1 blockade using a potentially novel drug-like selective TAK1 inhibitor, HS-276. Inhibiting TAK1 abrogated TGF-β1 stimulation of collagen synthesis and myofibroblasts differentiation in healthy skin fibroblasts, and it ameliorated constitutive activation of SSc skin fibroblasts. Moreover, treatment with HS-276 prevented dermal and pulmonary fibrosis and reduced the expression of profibrotic mediators in bleomycin-treated mice. Importantly, initiating HS-276 treatment even after fibrosis was already established prevented its progression in affected organs. Together, these findings implicate TAK1 in the pathogenesis of SSc and identify targeted TAK1 inhibition using a small molecule as a potential strategy for the treatment of SSc and other fibrotic diseases.

Echinacea Polyphenols Inhibit NLRP3-Dependent Pyroptosis, Apoptosis, and Necroptosis via Suppressing NO Production during Lipopolysaccharide-Induced Acute Lung Injury

PANoptosis is an intricate programmed death pathway that involves the interaction between pyroptosis, apoptosis, and necroptosis. We systematically explored the protective effect of Echinacea polyphenols (EPP) against the lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the underlying mechanisms both in vitro and in vivo. We noted that EPP pretreatment could significantly alleviate LPS-induced lung tissue injury and pulmonary edema. EPP inhibited the PANoptosis by regulating the expression of nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome, gasdermin D, caspase-8, caspase-3, and mixed lineage kinase domain-like protein. Meanwhile, a comparative study of EPP and inducible nitric oxide synthase inhibitor S-methylisothiourea sulfate indicated that EPP may play a preprotective role in inhibiting PANoptosis via reducing the activity of inducible nitric oxide synthase and the production of nitric oxide (NO) during ALI. Our results clearly indicated that PANoptosis existed in LPS-induced ALI, and EPP pretreatment could provide obvious protective effects to LPS-induced ALI by inhibiting PANoptosis, which may be related to NO production.

Discovery of 4-oxo-N-phenyl-1,4-dihydroquinoline-3-carboxamide derivatives as novel anti-inflammatory agents for the treatment of acute lung injury and sepsis

Acute lung injury (ALI) and sepsis, characterized by systemic inflammatory response syndrome, remain the major causes of death in severe patients. Inhibiting the release of proinflammatory cytokines is considered to be a promising method for the treatment of inflammation-related diseases. In this study, a total of 28 4-oxo-N-phenyl-1,4-dihydroquinoline-3-carboxamide derivatives were designed and synthesized and their anti-inflammatory activities in J774A.1 were evaluated. Among them, derivative 13a was found to significantly inhibit lipopolysaccharide (LPS)-induced expression of the proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) on J774A.1, THP-1 and LX-2 cells, and inhibited the activation of the NF-κB pathway. Furthermore, administration of 13ain vivo significantly improved the symptoms in LPS-induced ALI mice, including alleviation of pathological changes in the lung tissue, reduction of pulmonary edema, and inhibition of macrophage infiltration. Moreover, the administration of 13ain vivo significantly promoted survival in LPS-induced sepsis mice. 13a demonstrated favorable pharmacokinetic properties with T_1/2 value of 11.8 h and F value of 36.3%. Therefore, this study has identified a novel 4-oxo-N-phenyl-1,4-dihydroquinoline-3-carboxamide derivative, 13a, which is an effective anti-inflammatory agent. The findings have laid a foundation for the further development of agents to treat ALI and sepsis.

ICOS-Fc as innovative immunomodulatory approach to counteract inflammation and organ injury in sepsis

Inducible T cell co-stimulator (ICOS), an immune checkpoint protein expressed on activated T cells and its unique ligand, ICOSL, which is expressed on antigen-presenting cells and non-hematopoietic cells, have been extensively investigated in the immune response. Recent findings showed that a soluble recombinant form of ICOS (ICOS-Fc) can act as an innovative immunomodulatory drug as both antagonist of ICOS and agonist of ICOSL, modulating cytokine release and cell migration to inflamed tissues. Although the ICOS-ICOSL pathway has been poorly investigated in the septic context, a few studies have reported that septic patients have reduced ICOS expression in whole blood and increased serum levels of osteopontin (OPN), that is another ligand of ICOSL. Thus, we investigated the pathological role of the ICOS-ICOSL axis in the context of sepsis and the potential protective effects of its immunomodulation by administering ICOS-Fc in a murine model of sepsis. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP) in five-month-old male wild-type (WT) C57BL/6, ICOS-/-, ICOSL-/- and OPN-/- mice. One hour after the surgical procedure, either CLP or Sham (control) mice were randomly assigned to receive once ICOS-Fc, F119SICOS-Fc, a mutated form uncapable to bind ICOSL, or vehicle intravenously. Organs and plasma were collected 24 h after surgery for analyses. When compared to Sham mice, WT mice that underwent CLP developed within 24 h a higher clinical severity score, a reduced body temperature, an increase in plasma cytokines (TNF-α, IL-1β, IL-6, IFN-γ and IL-10), liver injury (AST and ALT) and kidney (creatinine and urea) dysfunction. Administration of ICOS-Fc to WT CLP mice reduced all of these abnormalities caused by sepsis. Similar beneficial effects were not seen in CLP-mice treated with F119SICOS-Fc. Treatment of CLP-mice with ICOS-Fc also attenuated the sepsis-induced local activation of FAK, P38 MAPK and NLRP3 inflammasome. ICOS-Fc seemed to act at both sides of the ICOS-ICOSL interaction, as the protective effect was lost in septic knockout mice for the ICOS or ICOSL genes, whereas it was maintained in OPN knockout mice. Collectively, our data show the beneficial effects of pharmacological modulation of the ICOS-ICOSL pathway in counteracting the sepsis-induced inflammation and organ dysfunction.