Lipopolysaccharide activation of the MEK-ERK1/2 pathway in human monocytic cells mediates tissue factor and tumor necrosis factor alpha expression by inducing Elk-1 phosphorylation and Egr-1 expression

Macropinocytosis regulates cytokine expression through Erk signaling in LPS-stimulated macrophages

Macropinocytosis, a type of large-scale endocytosis process, is induced in macrophages by extracellular stimuli, including lipopolysaccharide (LPS). In addition to uptake function, emerging evidence supports a link between macropinocytosis and LPS-induced signal transduction. Following LPS stimulation, membrane ruffles are induced to form cup-like structures known as macropinocytic cups, a necessary precursory step for macropinocytosis. We have recently shown that Akt is activated at the cups and is an upstream regulator of the Iκ-B/NF-κB pathway implicated in the production of IL-1α and IL-6. Here, we further investigated the molecular mechanisms and show that the macropinocytic cups also regulated the Ras/Mek/Erk/c-Fos pathway to modulate IL-1β expression independently of the Akt pathway. In addition, we observed that the cup-dependent Akt pathway downregulated the expression of IL-10, in which the activation of the Erk pathway was critical. Taken together, we propose that macropinocytic cups separately modulate the Akt and Erk pathways in cytokine expression.Key words: macropinocytosis, Erk, IL-1β, IL-10.

Early Growth Response 1 Plays an Essential Role in Proinflammatory and Osteoclastogenic Activities of Lipopolysaccharide-Stimulated Osteoblasts

Lipopolysaccharide (LPS) of Gram-negative bacteria in oral plaque is the major cause of periodontal disease. It is involved in the induction of inflammation and alveolar bone resorption at least partly by directly reacting to Toll-like receptor (TLR) 4 on osteoblasts. LPS induces osteoblasts to express proinflammatory cytokines, chemokines, and prostaglandins, as well as macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL), which directly activate adjacent osteoclasts toward bone resorption. However, the regulator mechanisms have not been fully revealed at the molecular level. Here, we have demonstrated that LPS rapidly induces expression of early growth response 1 (EGR1), a zinc-finger transcription factor, and analyzed its physiological functions in osteoblasts. In both primary osteoblasts and an osteoblast cell line, LPS induced expression of EGR1 mRNA and protein within 30 min and 60 min, respectively, which were relatively slower than in macrophages. Inhibition of EGR1 by siRNA significantly inhibited LPS-induced mRNA expression of the tumor necrosis factor (TNF), interleukin-6 (IL-6), chemokines, cyclooxygenase-2 (COX2), matrix metalloproteinase-13 (MMP13), M-CSF, and RANKL in osteoblasts. Moreover, forced overexpression of EGR1 by the inducible expression system was sufficient to increase mRNA expression levels of TNF, IL-6, COX2, MMP13, and RANKL without LPS stimulation. As for the intracellular signal transduction, LPS-induced EGR1 expression in osteoblasts was dependent on the unique c-Jun N-terminal kinase (JNK)-extracellular signal-regulated kinase (ERK) activation pathway. Our data suggest an essential role of EGR1 in osteoblast responses to LPS-inducing tissue inflammation and osteolysis, providing new insights into the pathogenesis of periodontal disease.

Beyond coagulation: Coagulation protease factor VIIa in cytoprotective response

Blood coagulation, the tightly regulated biological process prevents bleeding upon injury to the blood vessels. Vessel injury exposes the sub-endothelial tissue factor (TF) to the blood stream, thereby leading to the binding of coagulation protease, factor VII/activated VII with TF, and thus initiating the extrinsic pathway of blood coagulation. Apart from coagulation, FVIIa also promotes intracellular signaling via the activation of a unique class of G-protein-coupled receptor (GPCR) family protein, protease-activated receptor 1 (PAR1), thereby promoting anti-inflammation and endothelial barrier protection. Blood coagulation and inflammation are intrinsically connected, the activation of one process often leads to the activation of the other. The present review highlights the mechanisms by which FVIIa contributes to cytoprotective responses, either by direct action or through the release of extracellular vesicles (EVs) from vascular endothelium. FVIIa, due to its well-known ability to promote coagulation, is also used as a hemostatic agent in the treatment of several hyper bleeding disorders like hemophilia, thrombocytopenia etc. In addition to its hemostatic role, the topics discussed in the present review open a new therapeutic off-label effect of FVIIa, i.e., providing anti-inflammatory and vascular protective responses in several bleeding disorders and beyond.

The Relationship Between CSF1R Signaling, Monocyte-Macrophage Differentiation, and Susceptibility to Inflammatory Bowel Disease

More than 300 genomic loci have been associated with increased susceptibility to inflammatory bowel disease (IBD) through genome-wide association studies. A major challenge in the translation of genome-wide association studies to mechanistic insights lies in connecting noncoding variants to function. For example, single-nucleotide variants (SNVs) in the vicinity of the gene encoding the transcription factor ETS2 on human chromosome 21 are associated with the risk of developing IBD in Europeans. The peak of SNV association lies within a distal enhancer that may regulate ETS2 transcription. The interpretation of this and many other SNV associations with IBD depends on a model linking variation in transcriptional regulation to the likelihood of developing chronic intestinal inflammation. One model for the ETS2 locus is that overexpression in monocytes is causally associated with the risk allele, which in turn leads to a hyperinflammatory state. Here we summarize evidence for an alternative mechanism focused on negative regulators of monocyte-macrophage activation. We argue that IBD susceptibility arises from dysregulation of monocyte adaptation in the intestinal milieu to form resident intestinal macrophages that are anergic to inflammatory stimuli. This process depends on signals initiated by macrophage colony-stimulating factor (CSF1) binding to its receptor (CSF1R). Within this framework, ETS2 is a myeloid-specific transcription factor, expressed in pluripotent and committed progenitors and monocytes, and is down-regulated by CSF1, in common with many genes associated with IBD susceptibility, including NOD2. ETS2 is also both a downstream target and a mediator of the CSF1/CSF1R signaling pathway. Therapeutic targeting of ETS2 and its upstream regulators has the potential to prevent CSF1-dependent monocyte differentiation toward a prorepair resident macrophage phenotype and consequently exacerbate intestinal inflammation.

Erbin Regulates Tissue Factors Through Ras/Raf Pathway in Coagulation Disorders in Sepsis

Background

Sepsis, as a clinically critical disease, usually induces coagulation disorders. It has been reported that ERBB2 Interacting Protein (Erbin) is involved in the development of various inflammatory diseases, and macrophages are involved in the regulation of coagulation disorders in sepsis. However, the role of Erbin in coagulation disorders in sepsis and the relationship between Erbin and macrophage regulation of coagulation function are still unclear.

Methods

At the cellular level, macrophages were treated with lipopolysaccharide (LPS) or MEK inhibitor (PD98059), protein expression levels were detected by Western blot, co-immunoprecipitation (Co-IP), and immunofluorescence, mRNA expression levels were detected by quantitative real-time polymerase chain reaction (qPCR), and the concentration of tissue factor (TF) in cell supernatant was detected by enzyme linked immunosorbent assay (ELISA). At the animal level, the cecal ligation and perforation (CLP) model was constructed in mice, and the inflammatory response and coagulation disorder of mice were observed by hematoxylin-eosin (HE) staining, immunohistochemistry, ELISA, and automatic hemagglutination analyzer. The protein and mRNA expression level were detected by Western blot and qPCR. Pearson linear correlation analysis was used to analyze the correlation between the inflammation index and the coagulation function index.

Results

We confirmed that the Erbin is involved in the regulation of coagulation function by macrophages and plays a role in the coagulation disorder of sepsis. In vivo studies have shown that mice with Erbin deletion have more obvious enhanced coagulation function, and in vitro studies have shown that Erbin knockout mediated macrophage secretion of TF by activating the Ras/Raf pathway.

Conclusion

Erbin reduces the coagulation activation by inhibiting TF release from macrophages.

Decreased neurotensin induces ovulatory dysfunction via the NTSR1/ERK/EGR1 axis in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the predominant cause of subfertility in reproductive-aged women; however, its pathophysiology remains unknown. Neurotensin (NTS) is a member of the gut-brain peptide family and is involved in ovulation; its relationship with PCOS is unclear. Here, we found that NTS expression in ovarian granulosa cells and follicular fluids was markedly decreased in patients with PCOS. In the in vitro culture of cumulus-oocyte complexes, the neurotensin receptor 1 (NTSR1) antagonist SR48692 blocked cumulus expansion and oocyte meiotic maturation by inhibiting metabolic cooperation and damaging the mitochondrial structure in oocytes and surrounding cumulus cells. Furthermore, the ERK1/2-early growth response 1 pathway was found to be a key downstream mediator of NTS/NTSR1 in the ovulatory process. Animal studies showed that in vivo injection of SR48692 in mice reduced ovulation efficiency and contributed to irregular estrus cycles and polycystic ovary morphology. By contrast, NTS partially ameliorated the ovarian abnormalities in mice with dehydroepiandrosterone-induced PCOS. Our findings highlighted the critical role of NTS reduction and consequent abnormal NTSR1 signaling in the ovulatory dysfunction of PCOS, suggesting a potential strategy for PCOS treatment.

TLR-4: a promising target for chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) affects a significant majority of cancer patients, with up to 80% experiencing this severe and dose-limiting side effect while undergoing anti-cancer treatment. CIPN can be induced by a variety of drugs commonly employed in the management of both solid tumors and hematologic cancers. The inadequacies in comprehending the pharmacological interventions associated with CIPN and the subsequent signaling pathways have significantly contributed to the disappointing outcomes of several drugs in clinical trials. Recent investigations in pain research have demonstrated a growing inclination toward addressing neuro-inflammation as a strategy for managing chronic pain conditions. Notably, toll-like receptor-4 (TLR-4) has emerged as a key player in immune system activation and is undergoing extensive research. In this review, we emphasize the potential role of TLR-4 in neuropathic pain, highlighting its promise as a target for CIPN treatment. Furthermore, we explore and analyse the intricate interplay between TLR-4, diverse immune cells, downstream pathways, and receptors within the context of CIPN. A comprehensive exploration of these interactions provides valuable insights into the central role of TLR-4 in CIPN development, paving the way for potential ground-breaking therapeutic approaches to alleviate this debilitating condition.

MEK1/2- and ERK1/2-Mediated Lung Endothelial Injury and Altered Hemostasis Promote Diffuse Alveolar Hemorrhage in Murine Lupus

OBJECTIVE

About 3% of patients with lupus develop severe diffuse alveolar hemorrhage (DAH) with pulmonary vasculitis. C57BL/6 (B6) mice with pristane-induced lupus also develop DAH, but BALB/c mice are resistant. DAH is independent of Toll-like receptor signaling and other inflammatory pathways. This study examined the role of the MEK1/2 pathway (MEK1/2-ERK1/2, JNK, p38).

METHODS

B6 and BALB/c mice were treated with pristane with or without inhibitors of MEK1/2 (trametinib/GSK1120212 [GSK]), ERK1/2 (SCH772984 [SCH]), JNK, or p38. Effects on lung hemorrhage and hemostasis were determined.

RESULTS

GSK and SCH abolished DAH, whereas JNK and p38 inhibitors were ineffective. Apoptotic cells were present in lung samples from pristane-treated mice but not in mice receiving pristane and GSK, and endothelial dysfunction was normalized. Expression of the ERK1/2-regulated transcription factor early growth response 1 increased in pristane-treated B6, but not BALB/c, mice and was normalized by GSK. Pristane also increased expression of the anticoagulant genes Tfpi and Thbd in B6 mice. The ratio of Tfpi to tissue factor (F3) to Tfpi increased in B6 (but not BALB/c) mice and was normalized by GSK. Circulating thrombomodulin protein levels increased in B6 mice and returned to normal after GSK treatment. Consistent with augmented endothelial anticoagulant activity, pristane treatment increased tail bleeding in B6 mice.

CONCLUSION

Pristane treatment promotes lung endothelial injury and DAH in B6 mice by activating the MEK1/2-ERK1/2 pathway and impairing hemostasis. The hereditary factors determining susceptibility to lung injury and bleeding in pristane-induced lupus are relevant to the pathophysiology of life-threatening DAH in systemic lupus erythematosus and may help to optimize therapy.

Myeloperoxidase-deficient mice exposed to Zymosan exhibit severe neutrophilia and anemia with enhanced granulopoiesis and reduced erythropoiesis, accompanied by pulmonary inflammation

We previously reported that myeloperoxidase-deficient (MPO-/-) mice develop more severe neutrophil-rich lung inflammation than wild-type mice following intranasal Zymosan administration. Interestingly, we found that these mutant mice with severe lung inflammation also displayed pronounced neutrophilia and anemia, characterized by increased granulopoiesis and decreased erythropoiesis in the bone marrow, compared to wild-type mice. This condition was associated with higher concentrations of granulocyte-colony stimulating factor (G-CSF) in both the lungs and serum, a factor known to enhance granulopoiesis. Neutrophils accumulating in the lungs of MPO-/- mice produced greater amounts of G-CSF than those in wild-type mice, indicating that they are a significant source of G-CSF. In vitro experiments using signal transduction inhibitors and Western blot analysis revealed that MPO-/- neutrophils express higher levels of G-CSF mRNA in response to Zymosan, attributed to the upregulation of the IκB kinase/nuclear factor (NF)-κB pathway and the extracellular-signal-regulated kinase/NF-κB pathway. These findings highlight MPO as a critical regulator of granulopoiesis and erythropoiesis in inflamed tissues.

MEK1/2 and ERK1/2 mediated lung endothelial injury and altered hemostasis promote diffuse alveolar hemorrhage in murine lupus

Objective

About 3% of lupus patients develop severe diffuse alveolar hemorrhage (DAH) with pulmonary vasculitis. B6 mice with pristane-induced lupus also develop DAH, but BALB/c mice are resistant. DAH is independent of TLR signaling and other inflammatory pathways. This study examined the role of the mitogen-activated protein kinase pathway (MEK1/2-ERK1/2, JNK, p38).

Methods

B6 and BALB/c mice were treated with pristane ± inhibitors of MEK1/2 (trametinib/GSK1120212, "GSK"), ERK1/2 (SCH772984, "SCH"), JNK, or p38. Effects on lung hemorrhage and hemostasis were determined.

Results

GSK and SCH abolished DAH, whereas JNK and p38 inhibitors were ineffective. Apoptotic cells were present in lung from pristane-treated mice, but not mice receiving pristane+GSK and endothelial dysfunction was normalized. Expression of the ERK1/2-regulated transcription factor Egr1 increased in pristane-treated B6, but not BALB/c, mice and was normalized by GSK. Pristane also increased expression of the anticoagulant genes Tfpi (tissue factor pathway inhibitor) and Thbd (thrombomodulin) in B6 mice. The ratio of tissue factor ( F3 ) to Tfpi increased in B6 (but not BALB/c) mice and was normalized by GSK. Circulating Thbd protein increased in B6 mice and returned to normal after GSK treatment. Consistent with augmented endothelial anticoagulant activity, pristane treatment increased tail bleeding in B6 mice.

Conclusion

Pristane treatment promotes lung endothelial injury and DAH in B6 mice by activating the MEK1/2-ERK1/2 pathway and impairing hemostasis. The hereditary factors determining susceptibility to lung injury and bleeding in pristane-induced lupus are relevant to the pathophysiology of life-threatening DAH in SLE and may help to optimize therapy.

Glycolytic reprogramming fuels myeloid cell-driven hypercoagulability

BACKGROUND

Myeloid cell metabolic reprogramming is a hallmark of inflammatory disease; however, its role in inflammation-induced hypercoagulability is poorly understood.

OBJECTIVES

We aimed to evaluate the role of inflammation-associated metabolic reprogramming in regulating blood coagulation.

METHODS

We used novel myeloid cell-based global hemostasis assays and murine models of immunometabolic disease.

RESULTS

Glycolysis was essential for enhanced activated myeloid cell tissue factor expression and decryption, driving increased cell-dependent thrombin generation in response to inflammatory challenge. Similarly, inhibition of glycolysis enhanced activated macrophage fibrinolytic activity through reduced plasminogen activator inhibitor 1 activity. Macrophage polarization or activation markedly increased endothelial protein C receptor (EPCR) expression on monocytes and macrophages, leading to increased myeloid cell-dependent protein C activation. Importantly, inflammation-dependent EPCR expression on tissue-resident macrophages was also observed in vivo. Adipose tissue macrophages from obese mice fed a high-fat diet exhibited significantly enhanced EPCR expression and activated protein C generation compared with macrophages isolated from the adipose tissue of healthy mice. Similarly, the induction of colitis in mice prompted infiltration of EPCR+ innate myeloid cells within inflamed colonic tissue that were absent from the intestinal tissue of healthy mice.

CONCLUSION

Collectively, this study identifies immunometabolic regulation of myeloid cell hypercoagulability, opening new therapeutic possibilities for targeted mitigation of thromboinflammatory disease.

Monocyte Tissue Factor Expression: Lipopolysaccharide Induction and Roles in Pathological Activation of Coagulation

The coagulation system is a part of the mammalian host defense system. Pathogens and pathogen components, such as bacterial lipopolysaccharide (LPS), induce tissue factor (TF) expression in circulating monocytes that then activates the coagulation protease cascade. Formation of a clot limits dissemination of pathogens, enhances the recruitment of immune cells, and facilitates killing of pathogens. However, excessive activation of coagulation can lead to thrombosis. Here, we review studies on the mechanism of LPS induction of TF expression in monocytes and its contribution to thrombosis and disseminated intravascular coagulation. Binding of LPS to Toll-like receptor 4 on monocytes induces a transient expression of TF that involves activation of intracellular signaling pathways and binding of various transcription factors, such as c-rel/p65 and c-Fos/c-Jun, to the TF promoter. Inhibition of TF in endotoxemia and sepsis models reduces activation of coagulation and improves survival. Studies with endotoxemic mice showed that hematopoietic cells and myeloid cells play major roles in the activation of coagulation. Monocyte TF expression is also increased after surgery. Activated monocytes release TF-positive extracellular vesicles (EVs) and levels of circulating TF-positive EVs are increased in endotoxemic mice and in patients with sepsis. More recently, it was shown that inflammasomes contribute to the induction of TF expression and activation of coagulation in endotoxemic mice. Taken together, these studies indicate that monocyte TF plays a major role in activation of coagulation. Selective inhibition of monocyte TF expression may reduce pathologic activation of coagulation in sepsis and other diseases without affecting hemostasis.

RhoA balances microglial reactivity and survival during neuroinflammation

Microglia are the largest myeloid cell population in the brain. During injury, disease, or inflammation, microglia adopt different functional states primarily involved in restoring brain homeostasis. However, sustained or exacerbated microglia inflammatory reactivity can lead to brain damage. Dynamic cytoskeleton reorganization correlates with alterations of microglial reactivity driven by external cues, and proteins controlling cytoskeletal reorganization, such as the Rho GTPase RhoA, are well positioned to refine or adjust the functional state of the microglia during injury, disease, or inflammation. Here, we use multi-biosensor-based live-cell imaging approaches and tissue-specific conditional gene ablation in mice to understand the role of RhoA in microglial response to inflammation. We found that a decrease in RhoA activity is an absolute requirement for microglial metabolic reprogramming and reactivity to inflammation. However, without RhoA, inflammation disrupts Ca2+ and pH homeostasis, dampening mitochondrial function, worsening microglial necrosis, and triggering microglial apoptosis. Our results suggest that a minimum level of RhoA activity is obligatory to concatenate microglia inflammatory reactivity and survival during neuroinflammation.

L-theanine attenuates LPS-induced motor deficit in experimental rat model of Parkinson's disease: emphasis on mitochondrial activity, neuroinflammation, and neurotransmitters

RATIONALE

Parkinson's disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons. The pathogenesis of PD includes oxidative stress, mitochondrial dysfunction, neuroinflammation, and neurotransmitter dysregulation. L-theanine is found in green tea and has antioxidant, anti-inflammatory, and neuroprotective effects with a high blood brain barrier permeability.

OBJECTIVE

The objective of this study was to investigate the possible neuroprotective effect of L-theanine in lipopolysaccharide (LPS) induced motor deficits and striatal neurotoxicity in a rat model of PD.

METHODS

LPS was infused at a dose of 5 μg/5 μl PBS stereotaxically into SNpc of rats. Treatment with L-theanine (50 and 100 mg/kg; po) and Sinemet (36 mg/kg; po) was given from day 7 to 21 in of LPS injected rat. On a weekly basis all behavioral parameters were assessed, and animals were sacrificed on day 22. The striatum tissue of brain was isolated for biochemicals (Nitrite, GSH, catalase, SOD, mitochondrial complexes I and IV), neuroinflammatory markers, and neurotransmitters (serotonin, dopamine, norepinephrine, GABA, and glutamate) estimations.

RESULTS

Results revealed that L-theanine dose-dependently and significantly reversed motor deficits, assessed through locomotor and rotarod activity. Moreover, L-theanine attenuated biochemical markers, reduced oxidative stress, and neurotransmitters dysbalance in the brain. L-theanine treatment at 100 mg/kg; po substantially reduced these pathogenic events by increasing mitochondrial activity, restoring neurotransmitter levels, and inhibiting neuroinflammation.

CONCLUSIONS

These data suggest that the positive effects of L-theanine on motor coordination may be mediated by the suppression of NF-κB induced by LPS. Therefore, L-theanine would have a new therapeutic potential for PD.

Early growth response-1: Key mediators of cell death and novel targets for cardiovascular disease therapy

Significance

Cardiovascular diseases are seen to be a primary cause of death, and their prevalence has significantly increased across the globe in the past few years. Several studies have shown that cell death is closely linked to the pathogenesis of cardiovascular diseases. Furthermore, many molecular and cellular mechanisms are involved in the pathogenesis of the cardiac cell death mechanism. One of the factors that played a vital role in the pathogenesis of cardiac cell death mechanisms included the early growth response-1 (Egr-1) factor.

Recent Advances

Studies have shown that abnormal Egr-1 expression is linked to different animal and human disorders like heart failure and myocardial infarction. The biosynthesis of Egr-1 regulates its activity. Egr-1 can be triggered by many factors such as serum, cytokines, hormones, growth factors, endotoxins, mechanical injury, hypoxia, and shear stress. It also displays a pro-apoptotic effect on cardiac cells, under varying stress conditions. EGR1 mediates a broad range of biological responses to oxidative stress and cell death by combining the acute changes occurring in the cellular environment with sustained changes in gene expression.

Future Directions

The primary regulatory role played by the Egr-1-targeting DNAzymes, microRNAs, and oligonucleotide decoy strategies in cardiovascular diseases were identified to provide a reference to identify novel therapeutic targets for cardiovascular diseases.

Mice with double knockout of Egr-1 and RCAN1 exhibit reduced inflammation during Pseudomonas aeruginosa lung infection

Pseudomonas aeruginosa represents one of the major opportunistic pathogens, which causes nosocomial infections in immunocompromised individuals. The molecular mechanisms controlling the host immune response to P. aeruginosa infections are not completely understood. In our previous study, early growth response 1 (Egr-1) and regulator of calcineurin 1 (RCAN1) were found to positively and negatively regulate the inflammatory responses, respectively, during P. aeruginosa pulmonary infection, and both of them had an impact on activating NF-κB pathway. Herein, we examined the inflammatory responses of Egr-1/RCAN1 double knockout mice using a mouse model of P. aeruginosa acute pneumonia. As a result, the Egr-1/RCAN1 double knockout mice showed reduced production of proinflammatory cytokines (IL-1β, IL-6, TNF and MIP-2), diminished inflammatory cell infiltration and decreased mortality, which were similar to those of Egr-1-deficienct mice but different from those of RCAN1-deficient mice. In vitro studies demonstrated that Egr-1 mRNA transcription preceded RCAN1 isoform 4 (RCAN1.4) mRNA transcription in macrophages, and the macrophages with Egr-1 deficiency exhibited decreased RCAN1.4 mRNA levels upon P. aeruginosa LPS stimulation. Moreover, Egr-1/RCAN1 double-deficient macrophages had reduced NF-κB activation compared to RCAN1-deficient macrophages. Taken together, Egr-1 predominates over RCAN1 in regulating inflammation during P. aeruginosa acute lung infection, which influences RCAN1.4 gene expression.

VALPROIC ACID INHIBITS CLASSICAL MONOCYTE-DERIVED TISSUE FACTOR AND ALLEVIATES HEMORRHAGIC SHOCK-INDUCED ACUTE LUNG INJURY IN RATS

ABSTRACT

Background: Monocytes and monocyte-derived tissue factor (TF) promote the development of sepsis-induced acute lung injury (ALI). Classical monocytes (C-Mcs) can be induced to express TF. Valproic acid (VPA) alleviates hemorrhagic shock (HS)-induced ALI (HS/ALI) and inhibits TF expression in monocytes. We hypothesized that C-Mcs and C-Mc-derived TF promoted HS/ALI and that VPA could inhibit C-Mc-derived TF expression and attenuate HS/ALI. Methods: Wistar rats and THP-1 cells were used to evaluate our hypothesis. Monocyte subtypes were analyzed by flow cytometry; mRNA expression was measured by fluorescence quantitative polymerase chain reaction; protein expression was measured by Western blotting, immunofluorescence, or immunohistology; inflammatory cytokines levels were measured by enzyme-linked immunosorbent assay; and ALI scores were used to determine the degree of ALI. Results: The blood %C-Mcs and C-Mcs/non-C-Mcs ratios, monocyte TF levels, serum and/or lung inflammatory cytokine levels, and ALI scores of HS rats were significantly increased ( P < 0.05). After monocyte depletion and thrombin inhibition, the inflammatory cytokine levels and ALI scores were significantly decreased ( P < 0.05). VPA reduced the %C-Mcs and C-Mc/non-C-Mc ratios, TF expression, inflammatory cytokine levels, and ALI scores during HS ( P < 0.05) and inhibited HS-induced monocyte Egr-1 and p-ERK1/2 expression ( P < 0.05). VPA inhibited hypoxia-induced TF expression in THP-1 cells by regulating the p-ERK1/2-Egr-1 axis. Conclusion: C-Mcs and C-Mc-derived TF accelerate the development of HS/ALI by increasing thrombin production. VPA inhibits HS-induced C-Mc production of TF by regulating the p-ERK1/2-Egr-1 axis and alleviates HS/ALI.

Connectivity Mapping Using a Novel sv2a Loss-of-Function Zebrafish Epilepsy Model as a Powerful Strategy for Anti-epileptic Drug Discovery

Synaptic vesicle glycoprotein 2A (SV2A) regulates action potential-dependent neurotransmitter release and is commonly known as the primary binding site of an approved anti-epileptic drug, levetiracetam. Although several rodent knockout models have demonstrated the importance of SV2A for functional neurotransmission, its precise physiological function and role in epilepsy pathophysiology remains to be elucidated. Here, we present a novel sv2a knockout model in zebrafish, a vertebrate with complementary advantages to rodents. We demonstrated that 6 days post fertilization homozygous sv2a^–/– mutant zebrafish larvae, but not sv2a^+/– and sv2a^+/+ larvae, displayed locomotor hyperactivity and spontaneous epileptiform discharges, however, no major brain malformations could be observed. A partial rescue of this epileptiform brain activity could be observed after treatment with two commonly used anti-epileptic drugs, valproic acid and, surprisingly, levetiracetam. This observation indicated that additional targets, besides Sv2a, maybe are involved in the protective effects of levetiracetam against epileptic seizures. Furthermore, a transcriptome analysis provided insights into the neuropathological processes underlying the observed epileptic phenotype. While gene expression profiling revealed only one differentially expressed gene (DEG) between wildtype and sv2a^+/– larvae, there were 4386 and 3535 DEGs between wildtype and sv2a^–/–, and sv2a^+/– and sv2a^–/– larvae, respectively. Pathway and gene ontology (GO) enrichment analysis between wildtype and sv2a^–/– larvae revealed several pathways and GO terms enriched amongst up- and down-regulated genes, including MAPK signaling, synaptic vesicle cycle, and extracellular matrix organization, all known to be involved in epileptogenesis and epilepsy. Importantly, we used the Connectivity map database to identify compounds with opposing gene signatures compared to the one observed in sv2a^–/– larvae, to finally rescue the epileptic phenotype. Two out of three selected compounds rescued electrographic discharges in sv2a^–/– larvae, while negative controls did not. Taken together, our results demonstrate that sv2a deficiency leads to increased seizure vulnerability and provide valuable insight into the functional importance of sv2a in the brain in general. Furthermore, we provided evidence that the concept of connectivity mapping represents an attractive and powerful approach in the discovery of novel compounds against epilepsy.

Combined Administration of Curcumin and Chondroitin Sulfate Alleviates Cartilage Injury and Inflammation via NF-κB Pathway in Knee Osteoarthritis Rats

Objective: Osteoarthritis (OA) is a degenerative chronic disease that most often occurs in the knee joint. Studies have shown that some food supplements, such as curcumin and chondroitin sulfate, are effective in treating knee osteoarthritis (KOA) by exhibiting different protective effects. In this study, we further investigated the combined therapeutic effects of curcumin and chondroitin sulfate on cartilage injury in rats with arthritis. Methods: An experimental KOA model was induced by monosodium iodoacetate (MIA) in rats. All rats were randomly divided into five groups: Ctrl (control), model (saline), Cur (20 mg/kg curcumin in saline), CS (100 mg/kg chondroitin sulfate in saline), and CA (20 mg/kg curcumin and 100 mg/kg chondroitin sulfate in saline); drugs were given 2 weeks after MIA injection. The histomorphological changes of cartilage were observed by safranin fast green staining, H&E staining, and micro-CT scanning. Also, the levels of PGE2, TNF-α and IL-1β in the arthral fluid and serum were determined by the ELISA kits. The activities of SOD, CAT, COMP, MMP-3, and type II collagen were detected by biochemical kits. The expressions of TLR4, p-NF-κB, NF-κB, and COX-2 in cartilage were detected by Western blot. Results: Data show that serum levels of IL-1β (p < 0.05), SOD (p < 0.0001), and MMP-3 (p < 0.001) were downregulated significantly in the CA group when compared to those in the model group. Meanwhile, obvious repair of cartilage with higher contains collagen II (p < 0.0001) could be observed in the CA group than the ones in Cur or CS group. In addition, significant downregulation of the expression of p-p65/p65 (p < 0.05) was found in the CA group. Conclusion: Our findings showed that combined administration of curcumin and chondroitin sulfate could exert better repair for KOA in rat models. This may hold great promise for discovering potential drugs to treat KOA and may improve treatment options for it.

Anti-Inflammatory Effects of (3S)-Vestitol on Peritoneal Macrophages

The isoflavone (3S)-vestitol, obtained from red propolis, has exhibited anti-inflammatory, antimicrobial, and anti-caries activity; however, few manuscripts deal with its anti-inflammatory mechanisms in macrophages. The objective is to elucidate the anti-inflammatory mechanisms of (3S)-vestitol on those cells. Peritoneal macrophages of C57BL6 mice, stimulated with lipopolysaccharide, were treated with 0.37 to 0.59 µM of (3S)-vestitol for 48 h. Then, nitric oxide (NO) quantities, macrophages viability, the release of 20 cytokines and the transcription of several genes related to cytokine production and inflammatory response were evaluated. The Tukey–Kramer variance analysis test statistically analyzed the data. (3S)-vestitol 0.55 µM (V55) lowered NO release by 60% without altering cell viability and diminished IL-1β, IL-1α, G-CSF, IL-10 and GM-CSF levels. V55 reduced expression of Icam-1, Wnt5a and Mmp7 (associated to inflammation and tissue destruction in periodontitis) and Scd1, Scd2, Egf1 (correlated to atherosclerosis). V55 increased expression of Socs3 and Dab2 genes (inhibitors of cytokine signaling and NF-κB pathway), Apoe (associated to atherosclerosis control), Igf1 (encoder a protein with analogous effects to insulin) and Fgf10 (fibroblasts growth factor). (3S)-vestitol anti-inflammatory mechanisms involve cytokines and NF-κB pathway inhibition. Moreover, (3S)-vestitol may be a candidate for future in vivo investigations about the treatment/prevention of persistent inflammatory diseases such as atherosclerosis and periodontitis.

Soy Phospholipids Exert a Renoprotective Effect by Inhibiting the Nuclear Factor Kappa B Pathway in Macrophages

Complications associated with chronic kidney disease (CKD), which involves kidney inflammation, are a major health problem. Soy protein isolate (SPI) reportedly inhibits CKD exacerbation; however, its detailed action mechanism remains obscure. Therefore, the role of the polar lipid component of SPI in suppressing inflammation was investigated. Zucker fatty rats were divided into three groups and fed a diet containing casein, SPI, or casein + SPI ethanol extract (SPIEE) for 16 weeks. The isoflavones and phospholipids of SPIEE were evaluated for their anti-inflammatory effects. Rats in the SPI and casein + SPIEE groups showed reduced levels of the urinary N-acetyl-β-d-glucosaminidase and renal IL-1β mRNA (an inflammatory marker) compared with those in the casein group. In proximal tubular cells, genistein significantly inhibited monocyte chemoattractant protein-1 (MCP-1) expression induced by an IL-1β stimulus. In macrophages, soybean phospholipids suppressed lipopolysaccharide-induced IL-1β gene expression by inhibiting the phosphorylation of inhibitor κB and p65. Phosphatidylinositol (PI) was found to be essential for inhibition of IL-1β expression. SPIEE inhibited the exacerbation of kidney disease. Genistein and soybean phospholipids, especially soybean-specific phospholipids containing PI, effectively inhibited the inflammatory spiral in vitro. Hence, daily soybean intake may be effective for inhibiting chronic inflammation and slowing kidney disease progression.

Protease-activated receptor 2 enhances innate and inflammatory mechanisms induced by lipopolysaccharide in macrophages from C57BL/6 mice

OBJECTIVE

This study was conducted to investigate the effects of the synthetic PAR2 agonist peptide (PAR2-AP) SLIGRL-NH₂ on LPS-induced inflammatory mechanisms in peritoneal macrophages.

METHODS

Peritoneal macrophages obtained from C57BL/6 mice were incubated with PAR2-AP and/or LPS, and the phagocytosis of zymosan fluorescein isothiocyanate (FITC) particles; nitric oxide (NO), reactive oxygen species (ROS), and cytokine production; and inducible NO synthase (iNOS) expression in macrophages co-cultured with PAR-2-AP/LPS were evaluated.

RESULTS

Co-incubation of macrophages with PAR2AP (30 µM)/LPS (100 ng/mL) enhanced LPS-induced phagocytosis; production of NO, ROS, and the pro-inflammatory cytokines interleukin (IL)-1β, tumour necrosis factor (TNF)-α, IL-6, and C-C motif chemokine ligand (CCL)2; and iNOS expression and impaired the release of the anti-inflammatory cytokine IL-10 after 4 h of co-stimulation. In addition, PAR2AP increased the LPS-induced translocation of the p65 subunit of the pro-inflammatory transcription factor nuclear factor kappa B (NF-κB) and reduced the expression of inhibitor of NF-κB.

CONCLUSION

This study provides evidence of a role for PAR2 in macrophage response triggered by LPS enhancing the phagocytic activity and NO, ROS, and cytokine production, resulting in the initial and adequate macrophage response required for their innate response mechanisms.

APE1/Ref-1 Role in Inflammation and Immune Response

Apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional enzyme that is essential for maintaining cellular homeostasis. APE1 is the major apurinic/apyrimidinic endonuclease in the base excision repair pathway and acts as a redox-dependent regulator of several transcription factors, including NF-κB, AP-1, HIF-1α, and STAT3. These functions render APE1 vital to regulating cell signaling, senescence, and inflammatory pathways. In addition to regulating cytokine and chemokine expression through activation of redox sensitive transcription factors, APE1 participates in other critical processes in the immune response, including production of reactive oxygen species and class switch recombination. Furthermore, through participation in active chromatin demethylation, the repair function of APE1 also regulates transcription of some genes, including cytokines such as TNFα. The multiple functions of APE1 make it an essential regulator of the pathogenesis of several diseases, including cancer and neurological disorders. Therefore, APE1 inhibitors have therapeutic potential. APE1 is highly expressed in the central nervous system (CNS) and participates in tissue homeostasis, and its roles in neurodegenerative and neuroinflammatory diseases have been elucidated. This review discusses known roles of APE1 in innate and adaptive immunity, especially in the CNS, recent evidence of a role in the extracellular environment, and the therapeutic potential of APE1 inhibitors in infectious/immune diseases.

Molecular Mechanisms of Lipopolysaccharide (LPS) Induced Inflammation in an Immortalized Ovine Luteal Endothelial Cell Line (OLENDO)

Escherichia coli (E. coli) is the most common Gram-negative bacterium causing infection of the uterus or mammary gland and is one of the major causes of infertility in livestock. In those animals affected by E. coli driven LPS-mediated infections, fertility problems occur in part due to disrupted follicular and luteal functionality. However, the molecular mechanisms by which LPS induces inflammation, and specifically, the role of LPS in the disruption of capillary morphogenesis and endothelial barrier function remain unclear. Here, we hypothesized that LPS may lead to alterations in luteal angiogenesis and vascular function by inducing inflammatory reactions in endothelial cells. Accordingly, OLENDO cells were treated with LPS followed by evaluation of the expression of selected representative proinflammatory cytokines: NF-kB, IL6, IL8, TNFα, and ICAM 1. While TNFα was not affected by treatment with LPS, transcripts of NF-kB, IL6, and IL8 were affected in a dosage-dependent manner. Additionally, the activity of TLR2 and TLR4 was blocked, resulting in suppression of the LPS-induced expression of ICAM 1, NF-kB, IL6, and IL8. Inhibition of the PKA or MAPK/ERK pathways suppressed the LPS-stimulated expression of NF-kB, IL6, and IL8, whereas blocking the PKC pathway had the opposite effect. Furthermore, LPS-induced phosphorylation of Erk1 and Erk2 was inhibited when the TLR4 or MAPK/ERK pathways were blocked. Finally, LPS seems to induce inflammatory processes in OLENDO cells via TLR2 and TLR4, utilizing different signaling pathways.

Synergistic activity and immunomodulatory potential of levofloxacin and Synoeca-MP peptide against multi-resistant strains of Klebsiella pneumoniae

The purpose of this article is to study the isolated and combined effect of the peptides Synoeca-MP and IDR-1018 against multi-resistant clinical isolates of K. pneumoniae (Kp2177569 - LACEN) in vitro. The bactericidal activity of the peptide Synoeca-MP in combination with three different classes of commercial antimicrobials and its immunomodulatory potential was also evaluated. Synoeca-MP showed better antimicrobial activity than IDR-1018 and presented synergistic action combined with levofloxacin. Therefore, Synoeca-MP and levofloxacin, and the combination of both, were used in subsequent analyses. In the presence of heat-killed antigens, cellular viability and TNF-α levels was maintained, the production of NO increased and a reduction in IL-10 production was observed. The synergistic antibacterial effect between Synoeca-MP and levofloxacin was effective against multidrug-resistant strains of K. pneumoniae. The association of Synoeca-MP and levofloxacin may present a low modulating action of pro and anti-inflammatory mediators, based on these results.

Cytokine-like protein 1-induced survival of monocytes suggests a combined strategy targeting MCL1 and MAPK in CMML

Mouse models of chronic myeloid malignancies suggest that targeting mature cells of the malignant clone disrupts feedback loops that promote disease expansion. Here, we show that in chronic myelomonocytic leukemia (CMML), monocytes that accumulate in the peripheral blood show a decreased propensity to die by apoptosis. BH3 profiling demonstrates their addiction to myeloid cell leukemia-1 (MCL1), which can be targeted with the small molecule inhibitor S63845. RNA sequencing and DNA methylation pattern analysis both point to the implication of the mitogen-activated protein kinase (MAPK) pathway in the resistance of CMML monocytes to death and reveal an autocrine pathway in which the secreted cytokine-like protein 1 (CYTL1) promotes extracellular signal-regulated kinase (ERK) activation through C-C chemokine receptor type 2 (CCR2). Combined MAPK and MCL1 inhibition restores apoptosis of monocytes from patients with CMML and reduces the expansion of patient-derived xenografts in mice. These results show that the combined inhibition of MCL1 and MAPK is a promising approach to slow down CMML progression by inducing leukemic monocyte apoptosis.

Icariside II: Anticancer Potential and Molecular Targets in Solid Cancers

Icariside II, an active flavonoid, is extracted from the traditional Chinese medicinal herb Epimedii. It possesses multiple biological and pharmacological properties, including anti-inflammatory, anticancer, and anti-osteoporotic properties. In recent years, apoptosis has become the hot spot in anticancer therapies. Icariside II exerts positive effects on inducing apoptosis and inhibiting proliferation in various cancers. The antitumorigenic activity of Icariside II was also proven through cell cycle arrest, triggering autophagy, reducing cellular metabolism, and inhibiting cancer metastasis and tumor-associated angiogenesis. Additionally, Icariside II, as a natural product, contributed to a synergistic effect alongside chemotherapeutic drugs. Due to its poor aqueous solubility and permeability, more strategies were developed to improve its therapeutic effects. This review aimed to summarize the chemopreventive properties of Icariside II in solid tumors and reveal its underlying molecular mechanisms.

Inhibition of extracellular signal-regulated kinase/calpain-2 pathway reduces neuroinflammation and necroptosis after cerebral ischemia-reperfusion injury in a rat model of cardiac arrest

BACKGROUND

Cerebral ischemia-reperfusion injury (CIRI) is the leading cause of poor neurological prognosis after cardiopulmonary resuscitation (CPR). We previously reported that the extracellular signal-regulated kinase (ERK) activation mediates CIRI. Here, we explored the potential ERK/calpain-2 pathway role in CIRI using a rat model of cardiac arrest (CA).

METHODS

Adult male Sprague-Dawley rats suffered from CA/CPR-induced CIRI, received saline, DMSO, PD98059 (ERK1/2 inhibitor, 0.3 mg/kg), or MDL28170 (calpain inhibitor, 3.0 mg/kg) after spontaneous circulation recovery. The survival rate and the neurological deficit score (NDS) were utilized to assess the brain function. Hematoxylin stain, Nissl staining, and transmission electron microscopy were used to evaluate the neuron injury. The expression levels of p-ERK, ERK, calpain-2, neuroinflammation-related markers (GFAP, Iba1, IL-1β, TNF-α), and necroptosis proteins (TNFR1, RIPK1, RIPK3, p-MLKL, and MLKL) in the brain tissues were determined by western blotting and immunohistochemistry. Fluorescent multiplex immunohistochemistry was used to analyze the p-ERK, calpain-2, and RIPK3 co-expression in neurons, and RIPK3 expression levels in microglia or astrocytes.

RESULTS

At 24 h after CA/CPR, the rats in the saline-treated and DMSO groups presented with injury tissue morphology, low NDS, ERK/calpain-2 pathway activation, and inflammatory cytokine and necroptosis protein over-expression in the brain tissue. After PD98059 and MDL28170 treatment, the brain function was improved, while inflammatory response and necroptosis were suppressed by ERK/calpain-2 pathway inhibition.

CONCLUSION

Inflammation activation and necroptosis involved in CA/CPR-induced CIRI were regulated by the ERK/calpain-2 signaling pathway. Inhibition of that pathway can reduce neuroinflammation and necroptosis after CIRI in the CA model rats.

ERK1/2 Has Divergent Roles in LPS-Induced Microvascular Endothelial Cell Cytokine Production and Permeability

ABSTRACT

Endothelial cells play a major role in inflammatory responses to infection and sterile injury. Endothelial cells express Toll-like receptor 4 (TLR4) and are activated by LPS to express inflammatory cytokines/chemokines, and to undergo functional changes, including increased permeability. The extracellular signal-regulated kinase 1/2 (ERK1/2) mediates pro-inflammatory signaling in monocytes and macrophages, but the role of ERK1/2 in LPS-induced activation of microvascular endothelial cells has not been defined. We therefore studied the role of ERK1/2 in LPS-induced inflammatory activation and permeability of primary human lung microvascular endothelial cells (HMVEC). Inhibition of ERK1/2 augmented LPS-induced IL-6 and vascular cell adhesion protein (VCAM-1) production by HMVEC. ERK1/2 siRNA knockdown also augmented IL-6 production by LPS-treated HMVEC. Conversely, ERK1/2 inhibition abrogated permeability and restored cell-cell junctions of LPS-treated HMVEC. Consistent with the previously described pro-inflammatory role for ERK1/2 in leukocytes, inhibition of ERK1/2 reduced LPS-induced cytokine/chemokine production by primary human monocytes. Our study identifies a complex role for ERK1/2 in TLR4-activation of HMVEC, independent of myeloid differentiation primary response gene (MyD88) and TIR domain-containing adaptor inducing IFN-β (TRIF) signaling pathways. The activation of ERK1/2 limits LPS-induced IL-6 production by HMVEC, while at the same time promoting HMVEC permeability. Conversely, ERK1/2 activation promotes IL-6 production by human monocytes. Our results suggest that ERK1/2 may play an important role in the nuanced regulation of endothelial cell inflammation and vascular permeability in sepsis and injury.

Regulation of early growth response-1 (Egr-1) gene expression by Stat1-independent type I interferon signaling and respiratory viruses

Respiratory virus infection is one of the leading causes of death in the world. Activation of the Jak-Stat pathway by Interferon-alpha/beta (IFN-α/β) in lung epithelial cells is critical for innate immunity to respiratory viruses. Transcriptional factor profiling in the transcriptome and RNA analysis revealed that Early growth response-1 (EGR1/Egr-1) was rapidly induced by IFN-α/β and Toll-like receptor (TLR) ligands in multiple cell types. Studies in mutant cell lines lacking components of the interferon-stimulated gene factor complex (ISGF-3) revealed that IFN-β induction of Egr-1 was independent of Stat1, Stat2, or Irf9. Activation of the Mek/Erk-1/2 pathway was implicated in the rapid induction of Egr-1 by IFN-β in serum-starved mouse lung epithelial cells. Interrogation of multiple microarray datasets revealed that respiratory viruses including coronaviruses induced IFN-β and regulated Egr-1 expression in human lung cell lines. Furthermore, bioinformatic analysis revealed that type I interferon-stimulated genes and Egr-1 inducible genes including transcription factors, mediators of cell growth, and chemokines were differentially regulated in the human lung cell lines after coronavirus infection, and in the lung biopsies of COVID-19 patients.

Targeting fibroblast growth factor 23-responsive pathways uncovers controlling genes in kidney mineral metabolism

Fibroblast Growth Factor 23 (FGF23) is a bone-derived hormone that reduces kidney phosphate reabsorption and 1,25(OH)2 vitamin D synthesis via its required co-receptor alpha-Klotho. To identify novel genes that could serve as targets to control FGF23-mediated mineral metabolism, gene array and single-cell RNA sequencing were performed in wild type mouse kidneys. Gene array demonstrated that heparin-binding EGF-like growth factor (HBEGF) was significantly up-regulated following one-hour FGF23 treatment of wild type mice. Mice injected with HBEGF had phenotypes consistent with partial FGF23-mimetic activity including robust induction of Egr1, and increased Cyp24a1 mRNAs. Single cell RNA sequencing showed overlapping HBEGF and EGF-receptor expression mostly in the proximal tubule, and alpha-Klotho expression in proximal and distal tubule segments. In alpha-Klotho-null mice devoid of canonical FGF23 signaling, HBEGF injections significantly increased Egr1 and Cyp24a1 with correction of basally elevated Cyp27b1. Additionally, mice placed on a phosphate deficient diet to suppress FGF23 had endogenously increased Cyp27b1 mRNA, which was rescued in mice receiving HBEGF. In HEK293 cells with stable alpha-Klotho expression, FGF23 and HBEGF increased CYP24A1 mRNA expression. HBEGF, but not FGF23 bioactivity was blocked with EGF-receptor inhibition. Thus, our findings support that the paracrine/autocrine factor HBEGF could play novel roles in controlling genes downstream of FGF23 via targeting common signaling pathways.

2-Hydroxy-4-Methylbenzoic Anhydride Inhibits Neuroinflammation in Cellular and Experimental Animal Models of Parkinson's Disease

Microglia-mediated neuroinflammation is one of the key mechanisms involved in acute brain injury and chronic neurodegeneration. This study investigated the inhibitory effects of 2-hydroxy-4-methylbenzoic anhydride (HMA), a novel synthetic derivative of HTB (3-hydroxy-4-trifluoromethylbenzoic acid) on neuroinflammation and underlying mechanisms in activated microglia in vitro and an in vivo mouse model of Parkinson’s disease (PD). In vitro studies revealed that HMA significantly inhibited lipopolysaccharide (LPS)-stimulated excessive release of nitric oxide (NO) in a concentration dependent manner. In addition, HMA significantly suppressed both inducible NO synthase and cyclooxygenase-2 (COX-2) at the mRNA and protein levels in LPS-stimulated BV-2 microglia cells. Moreover, HMA significantly inhibited the proinflammatory cytokines such as interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha in LPS-stimulated BV-2 microglial cells. Furthermore, mechanistic studies ensured that the potent anti-neuroinflammatory effects of HMA (0.1, 1.0, and 10 μM) were mediated by phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) in LPS-stimulated BV-2 cells. In vivo evaluations revealed that intraperitoneal administration of potent neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 20 mg/kg, four times a 1 day) in mice resulted in activation of microglia in the brain in association with severe behavioral deficits as assessed using a pole test. However, prevention of microglial activation and attenuation of Parkinson’s disease (PD)-like behavioral changes was obtained by oral administration of HMA (30 mg/kg) for 14 days. Considering the overall results, our study showed that HMA exhibited strong anti-neuroinflammatory effects at lower concentrations than its parent compound. Further work is warranted in other animal and genetic models of PD for evaluating the efficacy of HMA to develop a potential therapeutic agent in the treatment of microglia-mediated neuroinflammatory disorders, including PD.

LPS Induces GM-CSF Production by Breast Cancer MDA-MB-231 Cells via Long-Chain Acyl-CoA Synthetase 1

Granulocyte–macrophage colony-stimulating factor (GM-CSF) is a monomeric glycoprotein that has been implicated in the tumor growth and progression of different types of cancer. GM-CSF is produced by various non-immune cells including MDA-MB-231 in response to various stimuli. However, the role of lipopolysaccharide (LPS) in the regulation of GM-CSF in MDA-MB-231 breast cancer cells so far remains unclear. Herein, we asked whether LPS could induce GM-CSF production in MDA-MB-231 cells, and if so, which signaling pathway was involved. MDA-MB-231 cells were treated with LPS or tumor necrosis factor alpha (TNF-α; positive control), and GM-CSF expression levels were determined by qRT-PCR, ELISA, and confocal microscopy. Phosphorylation of the mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-kB) signaling proteins were evaluated by flow cytometry. Our results show that LPS induces GM-CSF expression at both mRNA and protein levels in MDA-MBA-231 cells. Inhibition of acyl-CoA synthetase 1 (ACSL1) activity in the cells with triacsin C significantly reduces the secretion of GM-CSF. Furthermore, the inhibition of ACSL1 activity significantly blocks the LPS-mediated phosphorylation of p38 MAPK, MEK1/2, extracellular signal-regulated kinase (ERK)1/2, c-Jun NH2-terminal kinase (JNK), and nuclear factor-κB (NF-kB) in the cells. These findings provide the first evidence that LPS induces ACSL1-dependent GM-CSF gene expression in MDA-MB-231 breast cancer cells, which requires the activation of p38 MAPK, MEK1/2, ERK1/2, JNK, and NF-kB.

Inhibition of miRNA-34a Promotes M2 Macrophage Polarization and Improves LPS-Induced Lung Injury by Targeting Klf4

Acute respiratory distress syndrome (ARDS) is an outcome of an accelerated immune response that starts initially as a defensive measure, however, due to non-canonical signaling, it later proves to be fatal not only to the affected tissue but to the whole organ system. microRNAs are known for playing a decisive role in regulating the expression of genes involved in diverse functions such as lung development, repair, and inflammation. In-silico analyses of clinical data and microRNA databases predicted a probable interaction between miRNA-34a (miR-34a), mitogen-activated protein kinase 1 (ERK), and kruppel like factor 4 (Klf4). Parallel to in silico results, here, we show that intra-tracheal instillation of lipopolysaccharides (LPS) to mice enhanced miR-34a expression in lung macrophages. Inhibition of miR-34a significantly improved lung histology, whereas over-expression of miR-34a worsened the lung injury phenotype. miR-34a over-expression in macrophages were also demonstrated to favour pro-inflammatory M1 phenotype and inhibition of M2 polarization. In a quest to confirm this likely interaction, expression profiles of Klf4 as the putative target were analyzed in different macrophage polarizing conditions. Klf4 expression was found to be prominent in the miR-34a inhibitor-treated group but down-regulated in the miR-34a mimic treated group. Immuno-histopathological analyses of lung tissue from the mice treated with miR-34a inhibitor also showed reduced inflammatory M1 markers as well as enhanced cell proliferation. The present study indicates that miR-34a intensified LPS-induced lung injury and inflammation by regulating Klf4 and macrophage polarization, which may serve as a potential therapeutic target for acute lung injury/ARDS.

Ubiquitin Ligase COP1 Suppresses Neuroinflammation by Degrading c/EBPβ in Microglia

Dysregulated microglia are intimately involved in neurodegeneration, including Alzheimer's disease (AD) pathogenesis, but the mechanisms controlling pathogenic microglial gene expression remain poorly understood. The transcription factor CCAAT/enhancer binding protein beta (c/EBPβ) regulates pro-inflammatory genes in microglia and is upregulated in AD. We show expression of c/EBPβ in microglia is regulated post-translationally by the ubiquitin ligase COP1 (also called RFWD2). In the absence of COP1, c/EBPβ accumulates rapidly and drives a potent pro-inflammatory and neurodegeneration-related gene program, evidenced by increased neurotoxicity in microglia-neuronal co-cultures. Antibody blocking studies reveal that neurotoxicity is almost entirely attributable to complement. Remarkably, loss of a single allele of Cebpb prevented the pro-inflammatory phenotype. COP1-deficient microglia markedly accelerated tau-mediated neurodegeneration in a mouse model where activated microglia play a deleterious role. Thus, COP1 is an important suppressor of pathogenic c/EBPβ-dependent gene expression programs in microglia.

Lipopolysaccharide treatment stimulates Pocillopora coral genotype-specific immune responses but does not alter coral-associated bacteria communities

Corals are comprised of a coral host and associated microbes whose interactions are mediated by the coral innate immune system. The diversity of immune factors identified in the Pocillopora damicornis genome suggests that immunity is linked to maintaining microbial symbioses while also being able to detect pathogens. However, it is unclear which immune factors respond to specific microbe-associated molecular patterns and how these immune reactions simultaneously affect coral-associated bacteria. To investigate this, fragments of P. damicornis and P. acuta colonies from Taiwan were subjected to lipopolysaccharide (LPS) treatment to stimulate immune responses and measure bacteria community shifts. RNA-seq revealed genotype-specific immune responses to LPS involving the upregulation of immune receptors, transcription factors, and pore-forming toxins. Bacteria 16S sequencing revealed significantly different bacteria communities between coral genotypes but no differences in bacteria communities were caused by LPS. Our findings confirm that Pocillopora corals activate conserved immune factors in response to LPS and identify transcription factors coordinating Pocillopora corals' immune responses. Additionally, the strong effect of coral genotype on gene expression and bacteria communities highlights the importance of coral genotype in the investigation of coral host-microbe interactions.

Enzymatic Synthesis of Chondroitin Sulfate E to Attenuate Bacteria Lipopolysaccharide-Induced Organ Damage

Chondroitin sulfate E (CS-E) is a sulfated polysaccharide that contains repeating disaccharides of 4,6-disulfated N-acetylgalactosamine and glucuronic acid residues. Here, we report the enzymatic synthesis of three homogeneous CS-E oligosaccharides, including CS-E heptasaccharide (CS-E 7-mer), CS-E tridecasaccharide (CS-E13-mer), and CS-E nonadecasaccharide (CS-E 19-mer). The anti-inflammatory effect of CS-E 19-mer was investigated in this study. CS-E 19-mer neutralizes the cytotoxic effect of histones in a cell-based assay and in mice. We also demonstrate that CS-E 19-mer treatment improves survival and protects against organ damage in a mouse model of endotoxemia induced by bacterial lipopolysaccharide (LPS). CS-E19-mer directly interacts with circulating histones in the plasma from LPS-challenged mice. CS-E 19-mer does not display anticoagulant activity nor react with heparin-induced thrombocytopenia antibodies isolated from patients. The successful synthesis of CS-E oligosaccharides provides structurally defined carbohydrates for advancing CS-E research and offers a potential therapeutic agent to treat life-threatening systemic inflammation.

The activation trajectory of plasmacytoid dendritic cells in vivo during a viral infection

Plasmacytoid dendritic cells (pDCs) are a major source of type I interferon (IFN-I). What other functions pDCs exert in vivo during viral infections is controversial, and more studies are needed to understand their orchestration. In the present study, we characterize in depth and link pDC activation states in animals infected by mouse cytomegalovirus by combining Ifnb1 reporter mice with flow cytometry, single-cell RNA sequencing, confocal microscopy and a cognate CD4 T cell activation assay. We show that IFN-I production and T cell activation were performed by the same pDC, but these occurred sequentially in time and in different micro-anatomical locations. In addition, we show that pDC commitment to IFN-I production was marked early on by their downregulation of leukemia inhibitory factor receptor and was promoted by cell-intrinsic tumor necrosis factor signaling. We propose a new model for how individual pDCs are endowed to exert different functions in vivo during a viral infection, in a manner tightly orchestrated in time and space.

Nuclear Factor Kappa B Signaling Complexes in Acute Inflammation

Significance: Nuclear factor kappa B (NF-κB) is a master regulator of the inflammatory response and represents a key regulatory node in the complex inflammatory signaling network. In addition, selective NF-κB transcriptional activity on specific target genes occurs through the control of redox-sensitive NF-κB interactions. Recent Advances: The selective NF-κB response is mediated by redox-modulated NF-κB complexes with ribosomal protein S3 (RPS3), Pirin (PIR). cAMP response element-binding (CREB)-binding protein (CBP)/p300, peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), activator protein-1 (AP-1), signal transducer and activator of transcription 3 (STAT3), early growth response protein 1 (EGR-1), and SP-1. NF-κB is cooperatively coactivated with AP-1, STAT3, EGR-1, and SP-1 during the inflammatory process, whereas NF-κB complexes with CBP/p300 and PGC-1α regulate the expression of antioxidant genes. PGC-1α may act as selective repressor of phospho-p65 toward interleukin-6 (IL-6) in acute inflammation. p65 and nuclear factor erythroid 2-related factor 2 (NRF2) compete for binding to coactivator CBP/p300 playing opposite roles in the regulation of inflammatory genes. S-nitrosylation or tyrosine nitration favors the recruitment of specific NF-κB subunits to κB sites. Critical Issues: NF-κB is a redox-sensitive transcription factor that forms specific signaling complexes to regulate selectively the expression of target genes in acute inflammation. Protein-protein interactions with coregulatory proteins, other transcription factors, and chromatin-remodeling proteins provide transcriptional specificity to NF-κB. Furthermore, different NF-κB subunits may form distinct redox-sensitive homo- and heterodimers with distinct affinities for κB sites. Future Directions: Further research is required to elucidate the whole NF-κB interactome to fully characterize the complex NF-κB signaling network in redox signaling, inflammation, and cancer.

MAP Kinase driven actomyosin rearrangement is a crucial regulator of monocyte to macrophage differentiation

Rearrangement of actin cytoskeleton correlates significantly with the immune responses as the perturbation of cytoskeletal dynamics leads to many immune deficiencies. Mechanistic insights into this correlation remain unknown. Cellular spreading, the most characteristic phenotype associated with monocyte to macrophage differentiation, led us to investigate the contribution of actomyosin dynamics in monocyte differentiation. Our observation revealed that actomyosin reorganization intrinsically governs the process of monocyte to macrophage differentiation. Further, we established that the MAPK-driven signaling pathways regulate the cellular actomyosin dynamics that direct monocyte to macrophage differentiation. We also identified P42/44 Mitogen-Activated Protein Kinase (P42/44 MAPK), P38 Mitogen-Activated Protein Kinase (P38 MAPK), MAP Kinase Activated Protein Kinase 2 (MK-2), Heat Shock Protein 27 (Hsp-27), Lim Kinase (Lim K), non-muscle cofilin (n-cofilin), Myosin Light Chain Kinase (MLCK) and Myosin Light Chain (MLC) as critical components of the signaling network. Moreover, we have shown the involvement of the same signaling cascade in 3D gel-like microenvironment induced spontaneous monocyte to macrophage differentiation and in human blood-derived PBMC differentiation. Our study reveals new mechanistic insights into the process of monocyte to macrophage differentiation.

lnc003875/miR-363/EGR1 regulatory network in the carcinoma -associated fibroblasts controls the angiogenesis of human placental site trophoblastic tumor (PSTT)

The rare gestational trophoblastic neoplasia placental site trophoblastic tumor (PSTT) frequently demonstrates a high degree of vascularization, which may facilitate the tumor metastasis. However, the underlying mechanisms remain largely unknown. In the present study, we found that early growth response 1 (EGR1) was highly expressed in the carcinoma-associated fibroblasts (CAFs) of PSTT tissues. Further data showed that miR-363 down-regulated EGR1 expression whereas long non-coding RNA NONHSAT003875 (lnc003875) up-regulated EGR1 expression in PSTT derived CAFs. lnc003875 exerted no effect on miR-363 expression, but it recovered the decrease of EGR1 caused by miR-363 mimic. The conditioned media from PSTT CAFs treated with miR-363 mimic abrogated the tube formation capacity of human umbilical vein endothelial cells (HUVECs), which can be partially restored by lnc003875 over-expression. Moreover, over-expression of EGR1 promoted the secretion of Angiopoietin-1 (Ang-1) in PSTT derived CAFs and improved the tube formation of HUVECs, which could be effectively abrogated by Ang-1 siRNAs. In vivo vasculogenesis assay demonstrated that lnc003875/EGR1 in PSTT derived CAFs promoted the vasculogenesis of HUVECs in C57BL/6 mice. Collectively, these findings indicated that lnc003875/miR-363/EGR1/Ang-1 in CAFs may be crucial for the angiogenesis of PSTT.

IgE Contributes to Atherosclerosis and Obesity by Affecting Macrophage Polarization, Macrophage Protein Network, and Foam Cell Formation

OBJECTIVE

By binding to its high-affinity receptor FcεR1, IgE activates mast cells, macrophages, and other inflammatory and vascular cells. Recent studies support an essential role of IgE in cardiometabolic diseases. Plasma IgE level is an independent predictor of human coronary heart disease. Yet, a direct role of IgE and its mechanisms in cardiometabolic diseases remain incompletely understood. Approach and Results: Using atherosclerosis prone Apoe^-/- mice and IgE-deficient Ige^-/- mice, we demonstrated that IgE deficiency reduced atherosclerosis lesion burden, lesion lipid deposition, smooth muscle cell and endothelial cell contents, chemokine MCP (monocyte chemoattractant protein)-1 expression and macrophage accumulation. IgE deficiency also reduced bodyweight gain and increased glucose and insulin sensitivities with significantly reduced plasma cholesterol, triglyceride, insulin, and inflammatory cytokines and chemokines, including IL (interleukin)-6, IFN (interferon)-γ, and MCP-1. From atherosclerotic lesions and peritoneal macrophages from Apoe^-/-Ige^-/- mice that consumed an atherogenic diet, we detected reduced expression of M1 macrophage markers (CD68, MCP-1, TNF [tumor necrosis factor]-α, IL-6, and iNOS [inducible nitric oxide synthase]) but increased expression of M2 macrophage markers (Arg [arginase]-1 and IL-10) and macrophage-sterol-responsive-network molecules (complement C3, lipoprotein lipase, LDLR [low-density lipoprotein receptor]-related protein 1, and TFR [transferrin]) that suppress macrophage foam cell formation. These IgE activities can be reproduced in bone marrow-derived macrophages from wild-type mice, but muted in cells from FcεR1-deficient mice, or blocked by anti-IgE antibody or complement C3 deficiency.

CONCLUSIONS

IgE deficiency protects mice from diet-induced atherosclerosis, obesity, glucose tolerance, and insulin resistance by regulating macrophage polarization, macrophage-sterol-responsive-network gene expression, and foam cell formation.

Trametinib alleviates lipopolysaccharide-induced acute lung injury by inhibiting the MEK-ERK-Egr-1 pathway

Acute lung injury (ALI) is a devastating clinical disorder with a high mortality rate and for which there is no effective treatment. The main characteristic of ALI is uncontrolled inflammation, and macrophages play a critical role in the development of this disorder. Trametinib, an inhibitor of MAPK/ERK kinase (MEK) activity that possesses anti-inflammatory properties, has been approved for clinical use. Herein, the influence of trametinib and its underlying mechanism were investigated using a lipopolysaccharide (LPS)-induced murine ALI model. We found that trametinib treatment prevented the LPS-facilitated expression of proinflammatory mediators in macrophages, and this anti-inflammatory action was closely correlated with suppression of the MEK-ERK-early growth response (Egr)-1 pathway. Furthermore, trametinib treatment alleviated LPS-induced ALI in mice, and attenuated edema, proinflammatory mediator production, and neutrophil infiltration. Trametinib pretreatment also attenuated the MEK-ERK-Egr-1 pathway in lung tissues. In conclusion, these data demonstrate that trametinib pretreatment suppresses inflammation in LPS-activated macrophages in vitro and protects against murine ALI established by LPS administration in vivo through inhibition of the MEK-ERK-Egr-1 pathway. Therefore, trametinib might have therapeutic potential for ALI.

Early Growth Response 1 Deficiency Protects the Host against Pseudomonas aeruginosa Lung Infection

Pseudomonas aeruginosa is an opportunistic pathogen that is a common cause of nosocomial infections. The molecular mechanisms governing immune responses to P. aeruginosa infection remain incompletely defined. Early growth response 1 (Egr-1) is a zinc-finger transcription factor that controls inflammatory responses. Here, we characterized the role of Egr-1 in host defense against P. aeruginosa infection in a mouse model of acute bacterial pneumonia. Egr-1 expression was rapidly and transiently induced in response to P. aeruginosa infection. Egr-1-deficient mice displayed decreased mortality, reduced levels of proinflammatory cytokines (tumor necrosis factor [TNF], interleukin-1β [IL-1β], IL-6, IL-12, and IL-17), and enhanced bacterial clearance from the lung. Egr-1 deficiency caused diminished NF-κB activation in P. aeruginosa-infected macrophages independently of IκBα phosphorylation. A physical interaction between Egr-1 and NF-κB p65 was found in P. aeruginosa-infected macrophages, suggesting that Egr-1 could be required for assembly of heterodimeric transcription factors that direct synthesis of inflammatory mediators. Interestingly, Egr-1 deficiency had no impact on neutrophil recruitment in vivo due to its differential effects on chemokine production, which included diminished accumulation of KC (CXCL1), MIP2 (CXCL2), and IP-10 (CXCL10) and increased accumulation of LIX (CXCL5). Importantly, Egr-1-deficient macrophages and neutrophils displayed significant increases in nitric oxide production and bacterial killing ability that correlated with enhanced bacterial clearance in Egr-1-deficient mice. Together, these findings suggest that Egr-1 plays a detrimental role in host defense against P. aeruginosa acute lung infection by promoting systemic inflammation and negatively regulating the nitric oxide production that normally assists with bacterial clearance.

In vivo anti-inflammatory efficacy of the combined Bowman-Birk trypsin inhibitor and genistein isoflavone, two biological compounds from soybean

Soybean Bowman-Birk protease inhibitor (BBI) and genistein, two biological compounds from soybean, are well-known for their anti-inflammatory, antioxidant, and anticancer activities. The aim of this study was designing a BBI-genistein conjugate and then investigating its protective effect on lipopolysaccharide (LPS)-induced inflammation in BALB/c mice, compared with the effects of combination of BBI and genistein. BBI was purified from soybean and the BBI-genistein conjugate was synthesized. The BALB/c mice were intraperitoneally treated 2 hours before LPS induction. Our results showed that treatment with the combination of BBI and genistein greatly led to more reduced serum levels of tumor necrosis factor (TNF)-α and interferon (IFN)-γ compared with the treatments of BBI alone, the BBI-genistein conjugate, and genistein alone, respectively. Moreover, the expression of TNF-α and IFN-γ in the splenocytes was significantly downregulated along with improving host survival against the LPS-induced lethal endotoxemia in the same way. Our data support a new combined therapy using BBI and genistein, as natural anti-inflammatory agents, to develop a new drug for inflammatory diseases.

Activation of Galectin-3 (LGALS3) Transcription by Injurious Stimuli in the Liver Is Commonly Mediated by BRG1

Galectin-3 (encoded by LGALS3) is a glycan-binding protein that regulates a diverse range of pathophysiological processes contributing to the pathogenesis of human diseases. Previous studies have found that galectin-3 levels are up-regulated in the liver by a host of different injurious stimuli. The underlying epigenetic mechanism, however, is unclear. Here we report that conditional knockout of Brahma related gene (BRG1), a chromatin remodeling protein, in hepatocytes attenuated induction of galectin-3 expression in several different animal models of liver injury. Similarly, BRG1 depletion or pharmaceutical inhibition in cultured hepatocytes suppressed the induction of galectin-3 expression by treatment with LPS plus free fatty acid (palmitate). Further analysis revealed that BRG1 interacted with AP-1 to bind to the proximal galectin-3 promoter and activate transcription. Mechanistically, DNA demethylation surrounding the galectin-3 promoter appeared to be a rate-limiting step in BRG1-mediated activation of galectin-3 transcription. BRG1 recruited the DNA 5-methylcytosine dioxygenase TET1 to the galectin-3 to promote active DNA demethylation thereby activating galectin-3 transcription. Finally, TET1 silencing abrogated induction of galectin-3 expression by LPS plus palmitate in cultured hepatocytes. In conclusion, our data unveil a novel epigenetic pathway that contributes to injury-associated activation of galectin-3 transcription in hepatocytes.

Sustained Egr-1 Response via p38 MAP Kinase Signaling Modulates Early Immune Responses of Dendritic Cells Parasitized by Toxoplasma gondii

As a response to a diverse array of external stimuli, early growth response protein 1 (Egr-1) plays important roles in the transcriptional regulation of inflammation and the cellular immune response. However, a number of intracellular pathogens colonize immune cells and the implication of Egr-1 in the host-pathogen interplay has remained elusive. Here, we have characterized the Egr-1 responses of primary murine and human dendritic cells (DCs) upon challenge with the obligate intracellular parasite Toxoplasma gondii. We report that live intracellular parasites induce a sustained high expression of Egr-1 in DCs, different from the immediate-early Egr-1 response to parasite lysates, inactivated parasites or LPS. Moreover, a distinct nuclear localization of elevated amounts of Egr-1 protein was detected in infected DCs, but not in by-stander DCs. The ERK1/2 MAPK signaling pathway mediated the canonical immediate-early Egr-1 response to soluble antigens in a MyD88/TLR-dependent fashion. In contrast, a non-canonical extended Egr-1 response that relied primarily on p38 MAPK signaling was induced by intracellular parasites and was exhibited similarly by MyD88-deficient and wildtype DCs. The extended phase Egr-1 response was dramatically reduced upon challenge of DCs with T. gondii parasites deficient in GRA24, a secreted p38-interacting protein. Further, Egr-1-silenced primary DCs maintained their migratory responses upon T. gondii challenge. Importantly, Egr-1 silencing led to elevated expression of co-stimulatory molecules (CD40, CD80) in Toxoplasma-infected DCs and in LPS-challenged immature DCs, indicating that Egr-1 responses suppressed maturation of DCs. Moreover, the IL-12 and IL-2 responses of Toxoplasma-challenged DCs were modulated in a GRA24-dependent fashion. Jointly, the data show that the Egr-1 responses of DCs to microbial external stimuli and intracellular stimuli can be selectively mediated by ERK1/2 or p38 MAPK signaling, and that Egr-1 can act as an intrinsic negative modulator of maturation in primary DCs.

Identification of phenothiazine as an ETV1‑targeting agent in gastrointestinal stromal tumors using the Connectivity Map

Gastrointestinal stromal tumors (GISTs) are gastrointestinal tract sarcomas that commonly contain a mutation in the tyrosine kinases, KIT and platelet‑derived growth factor receptor A (PDGFRA). Imatinib, sunitinib and regorafenib are all effective tyrosine kinase inhibitors; however, acquired resistance is inevitable. The E26 variant 1 (ETV1) pathway has been found to be a key downstream effector of KIT and is therefore a reasonable therapeutic target for this disease. In this study, we explored the potential agents targeting ETV1 in GISTs by uploading an ETV1 knockout gene signature of GIST cell lines to the pattern‑matching software 'Connectivity Map'. The activity and mechanisms of identified agents were examined using an in vitro model. Four drugs were identified: Suberanilohydroxamic acid and trichostatin [two histone deacetylase inhibitors (HDACIs)] and trifluoperazine and thioridazine (two phenothiazine‑class drugs). Western blot analysis demonstrated that all four drugs had ETV1‑downregulating effects. As HDACIs have been previously studied in GISTs, we focused on phenothiazine. Phenothiazine was found to exert cytotoxicity and to induce apoptosis and autophagy in GISTs. Treatment with phenothiazine had little effect on the KIT/AKT/mammalian target of rapamycin (mTOR) pathway, but instead upregulated extracellular‑signal‑regulated kinase (ERK) activity. A combination of phenothiazine and a MEK inhibitor had a synergistic cytotoxic effect on GISTs. Western blot analysis indicated that ELK1 and early growth response 1 (EGR1) were activated/upregulated following phenothiazine treatment, and the MEK inhibitor/phenothiazine combination downregulated the ERK/ELK1/EGR1 pathway, resulting in diminished autophagy, as well as enhanced apoptosis. On the whole, the findings of this study established phenothiazine as a novel class of therapeutic agents in GIST treatment and demonstrate that a combination of phenothiazine and MEK inhibitor has great potential for use in the treatment of GISTs.

Effects of SHINBARO2 on Rat Models of Lumbar Spinal Stenosis

Lumbar spinal stenosis (LSS) is a major cause of chronic low back pain; however, only a few therapies which have been used in clinics still have limited effects on functional recovery. SHINBARO2 is a refined traditional formulation for inflamed lesions and relieve pain of muscular skeletal disease. This study aimed at investigating the effects of SHINBARO2 on LSS and at determining its underlying molecular mechanism in rat models. The LSS rat models were set up by surgical operations in 6-week-old male Sprague-Dawley rats. SHINBARO2 was orally or intraperitoneally administered for 14 days. The motor and sensory ability of rats were evaluated using the activity cage and hot plate method. On the termination day, total vertebrae including the disc and spinal cord were excised for ex vivo study. SHINBARO2 improved locomotor functions and pain sensitivity in LSS rat models. Mechanism study suggested that SHINBARO2 inhibited the production of nitric oxide and prostaglandin E₂ in tissues from LSS-induced rats. SHINBARO2 also suppressed the expression of proinflammatory cytokines including tumor necrosis factor-α and interleukin-1β. The activation of NF-κB by LSS surgery was effectively reduced by SHINBARO2, which coincided with the inhibition of IκB degradation. In addition, brain-derived neurotrophic factor (BDNF), a potent promoter of neurite growth, and its downstream ERK signaling were also regulated by SHINBARO2. These findings suggest that the effect of SHINBARO2 might be associated in part with the anti-inflammation and pain control in LSS rat models.