TNF-stimulated MAP kinase activation mediated by a Rho family GTPase signaling pathway

Inflammatory gene regulation by Cdc42 in airway epithelial cells

Cytokine release from airway epithelial cells is a key immunological process that coordinates an immune response in the lungs. We propose that the Rho GTPase, Cdc42, regulates both transcription and trafficking of cytokines, ultimately affecting the essential process of cytokine release and subsequent inflammation in the lungs. Here, we examined the pro-inflammatory transcriptional profile that occurs in bronchial epithelial cells (BEAS-2B) in response to TNF-α using RNA-Seq and differential gene expression analysis. To interrogate the role of Cdc42 in inflammatory gene expression, we used a pharmacological inhibitor of Cdc42, ML141, and determined changes in the transcriptomic profile induced by Cdc42 inhibition. Our results indicated that Cdc42 inhibition with ML141 resulted in a unique inflammatory phenotype concomitant with increased gene expression of ER stress genes, Golgi membrane and vesicle transport genes. To further interrogate the inflammatory pathways regulated by Cdc42, we made BEAS-2B knockdown strains for the signaling targets TRIB3, DUSP5, SESN2 and BMP4, which showed high differential expression in response to Cdc42 inhibition. Depletion of DUSP5 and TRIB3 reduced the pro-inflammatory response triggered by Cdc42 inhibition as shown by a reduction in cytokine transcript levels. Depletion of SESN2 and BMP4 did not affect cytokine transcript level, however, Golgi fragmentation was reduced. These results provide further evidence that in airway epithelial cells, Cdc42 is part of a signaling network that controls inflammatory gene expression and secretion by regulating Golgi integrity. Summary sentence:We define the Cdc42-regulated gene networks for inflammatory signaling in airway epithelial cells which includes regulation of ER stress response and vesicle trafficking pathways.

Coenzyme Q10 mitigates cadmium cardiotoxicity by downregulating NF-κB/NLRP3 inflammasome axis and attenuating oxidative stress in mice

Coenzyme Q10 (CoQ10) occurs naturally in the body and possesses antioxidant and cardioprotective effects. Cardiotoxicity has emerged as a serious effect of the exposure to cadmium (Cd). This study investigated the curative potential of CoQ10 on Cd cardiotoxicity in mice, emphasizing the involvement of oxidative stress (OS) and NF-κB/NLRP3 inflammasome axis. Mice received a single intraperitoneal dose of CdCl2 (6.5 mg/kg) and a week after, CoQ10 (100 mg/kg) was supplemented daily for 14 days. Mice that received Cd exhibited cardiac injury manifested by the elevated circulating cardiac troponin T (cTnT), CK-MB, LDH and AST. The histopathological and ultrastructural investigations supported the biochemical findings of cardiotoxicity in Cd-exposed mice. Cd administration increased cardiac MDA, NO and 8-oxodG while suppressed GSH and antioxidant enzymes. CoQ10 decreased serum CK-MB, LDH, AST and cTnT, ameliorated histopathological and ultrastructural changes in the heart of mice, decreased cardiac MDA, NO, and 8-OHdG and improved antioxidants. CoQ10 downregulated NF-κB p65, NLRP3 inflammasome, IL-1β, MCP-1, JNK1, and TGF-β in the heart of Cd-administered mice. Moreover, in silico molecular docking revealed the binding potential between CoQ10 and NF-κB, ASC1 PYD domain, NLRP3 PYD domain, MCP-1, and JNK. In conclusion, CoQ10 ameliorated Cd cardiotoxicity by preventing OS and inflammation and modulating NF-κB/NLRP3 inflammasome axis in mice. Therefore, CoQ10 exhibits potent therapeutic benefits in safeguarding cardiac tissue from the harmful consequences of exposure to Cd.

TNF-alpha promotes cilia elongation via mixed lineage kinases signaling in mouse fibroblasts and human RPE-1 cells

The primary cilium is a characteristic feature of most non-immune cells and functions as an environmental signal transduction sensor. The defects in primary cilium have profound effects on the developmental program, including the maturation of retinal epithelium. The ciliary length is tightly regulated during ciliogenesis, but the impact of inflammation on ciliary length remains elusive. The current study investigates the outcome of inflammatory stimuli for the primary cilium length in retinal epithelium cells and mouse embryonic fibroblasts. Here, we report that exposure to the pro-inflammatory cytokine TNF-alpha elongates cilia in a mixed-lineage kinase (MLK)-dependent manner. Pro-inflammatory stimuli such as bacterial LPS and interferon-gamma have similar effects on ciliary length. In contrast, febrile condition-mimicking heat stress dramatically reduced the number of ciliated cells regardless of TNF-alpha exposure but did not shorten TNF-induced elongation, suggesting distinct but rapid effects of inflammatory stresses on ciliogenesis.

TNF-α can promote membrane invasion by activating the MAPK/MMP9 signaling pathway through autocrine in bone-invasive pituitary adenoma

AIMS

A bone-invasive pituitary adenoma exhibits aggressive behavior, leading to a worse prognosis. We have found that TNF-α promotes bone invasion by facilitating the differentiation of osteoclasts, however, before bone-invasive pituitary adenoma invades bone tissue, it needs to penetrate the dura mater, and this mechanism is not yet clear.

METHODS

We performed transcriptome microarrays on specimens of bone-invasive pituitary adenomas (BIPAs) and noninvasive pituitary adenomas (NIPAs) and conducted differential expressed gene analysis and enrichment analysis. We altered the expression of TNF-α through plasmids, then validated the effects of TNF-α on GH3 cells and verified the efficacy of the TNF-α inhibitor SPD304. Finally, the effects of TNF-α were validated in in vivo experiments.

RESULTS

Pathway act work showed that the MAPK pathway was significantly implicated in the pathway network. The expression of TNF-α, MMP9, and p-p38 is higher in BIPAs than in NIPAs. Overexpression of TNF-α elevated the expression of MAPK pathway proteins and MMP9 in GH3 cells, as well as promoted proliferation, migration, and invasion of GH3 cells. Flow cytometry indicated that TNF-α overexpression increased the G2 phase ratio in GH3 cells and inhibited apoptosis. The expression of MMP9 was reduced after blocking the P38 MAPK pathway; overexpression of MMP9 promoted invasion of GH3 cells. In vivo experiments confirm that the TNF-α overexpression group has larger tumor volumes. SPD304 was able to suppress the effects caused by TNF-α overexpression.

CONCLUSION

Bone-invasive pituitary adenoma secretes higher levels of TNF-α, which then acts on itself in an autocrine manner, activating the MAPK pathway and promoting the expression of MMP9, thereby accelerating the membrane invasion process. SPD304 significantly inhibits the effect of TNF-α and may be applied in the clinical treatment of bone-invasive pituitary adenoma.

Differential co-expression network analysis elucidated genes associated with sensitivity to farnesyltransferase inhibitor and prognosis of acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease and the most common form of acute leukemia with a poor prognosis. Due to its complexity, the disease requires the identification of biomarkers for reliable prognosis. To identify potential disease genes that regulate patient prognosis, we used differential co-expression network analysis and transcriptomics data from relapsed, refractory, and previously untreated AML patients based on their response to treatment in the present study. In addition, we combined functional genomics and transcriptomics data to identify novel and therapeutically potential systems biomarkers for patients who do or do not respond to treatment. As a result, we constructed co-expression networks for response and non-response cases and identified a highly interconnected group of genes consisting of SECISBP2L, MAN1A2, PRPF31, VASP, and SNAPC1 in the response network and a group consisting of PHTF2, SLC11A2, PDLIM5, OTUB1, and KLRD1 in the non-response network, both of which showed high prognostic performance with hazard ratios of 4.12 and 3.66, respectively. Remarkably, ETS1, GATA2, AR, YBX1, and FOXP3 were found to be important transcription factors in both networks. The prognostic indicators reported here could be considered as a resource for identifying tumorigenesis and chemoresistance to farnesyltransferase inhibitor. They could help identify important research directions for the development of new prognostic and therapeutic techniques for AML.

Phellinus merrillii extracts induce apoptosis of vascular smooth muscle cells via intrinsic and extrinsic pathways

Restenosis frequently occurs after balloon angioplasty. Percutaneous coronary intervention (PCI)-induced artery damage is a significant part of triggering restenosis of the vascular smooth muscles (VSMC). This study aimed to study how ethanol extract of Phellinus merrillii (EPM) affected balloon injury-induced overgrowth of VSMC, indicating neointima formation. Firstly, our results demonstrated that EPM notably decreased VSMC viability. A fragmentation assay and Annexin V/Propidium Iodide apoptosis assay showed that higher doses of EPM significantly induced the apoptosis of VSMC after 24 h of exposure. Total protein extracted from VSMC treated with EPM in various time and concentration periods was then conducted in Western blotting analysis. Our data demonstrated that EPM substantially elevated the p53, p21, Fas, Bax, p-p38, and active caspase-3 protein expressions. The results indicated that EPM induces VSMC apoptosis via intrinsic and extrinsic pathways. Also, our results demonstrated that EPM effectively attenuated the balloon injury-induced neointima formation. In conclusion, the information offers a mechanism of EPM in inducing the VSMC apoptosis, thus as a potential interference for restenosis.

Therapeutic potential of natural products in inflammation: underlying molecular mechanisms, clinical outcomes, technological advances, and future perspectives

Chronic inflammation is a common underlying factor in many major diseases, including heart disease, diabetes, cancer, and autoimmune disorders, and is responsible for up to 60% of all deaths worldwide. Metformin, statins, and corticosteroids, and NSAIDs (non-steroidal anti-inflammatory drugs) are often given as anti-inflammatory pharmaceuticals, however, often have even more debilitating side effects than the illness itself. The natural product-based therapy of inflammation-related diseases has no adverse effects and good beneficial results compared to substitute conventional anti-inflammatory medications. In this review article, we provide a concise overview of present pharmacological treatments, the pathophysiology of inflammation, and the signaling pathways that underlie it. In addition, we focus on the most promising natural products identified as potential anti-inflammatory therapeutic agents. Moreover, preclinical studies and clinical trials evaluating the efficacy of natural products as anti-inflammatory therapeutic agents and their pragmatic applications with promising outcomes are reviewed. In addition, the safety, side effects and technical barriers of natural products are discussed. Furthermore, we also summarized the latest technological advances in the discovery and scientific development of natural products-based medicine.

USP14 promotes colorectal cancer progression by targeting JNK for stabilization

MAPK/JNK signaling is pivotal in carcinogenesis. However, ubiquitin-mediated homeostasis of JNK remains to be verified. Here, with results from RNA sequencing (RNA-seq) and luciferase reporter pathway identification, we show that USP14 orchestrates MAPK/JNK signaling and identify USP14 as a deubiquitinase that interacts and stabilizes JNK. USP14 is elevated in colorectal cancer patients and is positively associated with JNK protein and downstream gene expression. USP14 ablation reduces cancer cell proliferation in vitro and colorectal tumorigenesis in vivo by downregulating MAPK/JNK pathway activation. Moreover, USP14 expression is induced by TNF-α, forming a feedback loop with JNK and leading to tumor amplification. Our study suggests that elevated expression of USP14 promotes MAPK/JNK signaling by stabilizing JNK, which in turn augments colorectal carcinogenesis, indicating a potential therapeutic target for colorectal cancer patients with increased USP14 expression.

Role of Oxidative Stress in Liver Disorders

Oxygen is vital for life as it is required for many different enzymatic reactions involved in intermediate metabolism and xenobiotic biotransformation. Moreover, oxygen consumption in the electron transport chain of mitochondria is used to drive the synthesis of ATP to meet the energetic demands of cells. However, toxic free radicals are generated as byproducts of molecular oxygen consumption. Oxidative stress ensues not only when the production of reactive oxygen species (ROS) exceeds the endogenous antioxidant defense mechanism of cells, but it can also occur as a consequence of an unbalance between antioxidant strategies. Given the important role of hepatocytes in the biotransformation and metabolism of xenobiotics, ROS production represents a critical event in liver physiology, and increasing evidence suggests that oxidative stress contributes to the development of many liver diseases. The present review, which is part of the special issue “Oxidant stress in Liver Diseases”, aims to provide an overview of the sources and targets of ROS in different liver diseases and highlights the pivotal role of oxidative stress in cell death. In addition, current antioxidant therapies as treatment options for such disorders and their limitations for future trial design are discussed.

Mixed lineage kinase 3 requires a functional CRIB domain for regulation of blood pressure, cardiac hypertrophy, and left ventricular function

Mixed lineage kinase 3 (MLK3) modulates blood pressure and left ventricular function, but the mechanisms governing these effects remain unclear. In the current study, we therefore investigated the role of the MLK3 Cdc42/Rac interactive binding (CRIB) domain in cardiovascular physiology. We examined baseline and left ventricular pressure overload responses in a MLK3 CRIB mutant (MLK3C/C) mouse, which harbors point mutations in the CRIB domain to disrupt MLK3 activation by Cdc42. Male and female MLK3C/C mice displayed increased invasively measured blood pressure compared with wild-type (MLK3+/+) littermate controls. MLK3C/C mice of both sexes also developed left and right ventricular hypertrophy but normal baseline LV function by echocardiography and invasive hemodynamics. In LV tissue from MLK3C/C mice, map3k11 mRNA, which encodes MLK3, and MLK3 protein were reduced by 74 ± 6% and 73 ± 7%, respectively. After 1-wk LV pressure overload with 25-gauge transaortic constriction (TAC), male MLK3C/C mice developed no differences in LV hypertrophy but displayed reduction in the LV systolic indices ejection fraction and dP/dt normalized to instantaneous pressure. JNK activation was also reduced in LV tissue of MLK3C/C TAC mice. TAC induced MLK3 translocation from cytosolic fraction to membrane fraction in LV tissue from MLK3+/+ but not MLK3C/C mice. These findings identify a role of the MLK3 CRIB domain in MLK3 regulation of basal blood pressure and cardiac morphology, and in promoting the compensatory LV response to pressure overload.NEW & NOTEWORTHY Here, we identified that the presence of two discrete point mutations within the Cdc42/Rac interaction and binding domain of the protein MLK3 recapitulates the effects of whole body MLK3 deletion on blood pressure, cardiac hypertrophy, and left ventricular compensation after pressure overload. These findings implicate the CRIB domain, and thus MLK3 activation by this domain, as critical for maintenance of cardiovascular homeostasis.

Associations of Prior Chronic Use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and Glucocorticoids With Cachexia Incidence and Survival

Background

Cachexia is an inflammatory and metabolic syndrome of unintentional weight loss through depletion of muscle and adipose tissue. There is limited knowledge of how chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids affect cachexia development. The purpose of this study was to investigate associations between prior long-term use of NSAIDs or glucocorticoids with cachexia incidence and post-diagnosis weight loss progression in a retrospective cancer patient cohort.

Methods

Of 3,802 lung or gastrointestinal cancer patient records, 3,180 comprised our final cohort. Patient demographic information, tumor qualities, medication histories, and comorbidities were assessed. Cachexia was defined as having developed prior to oncologic treatment. Statistical evaluations included categorical, multivariate logistic regression, and log-rank survival analyses. Development of substantial post-diagnosis weight loss was calculated and interpreted for patients without cachexia at diagnosis.

Results

Chronic prior use of any NSAID or glucocorticoid medication was associated with approximate absolute and relative reductions in cachexia incidence at diagnosis of 10 and 25 percent (P<0.0001). In multivariate analyses, NSAID medications demonstrated a 23 percent reduction in cachexia incidence likelihood (OR=0.770; 95% CI=0.594, 0.998; P=0.0481). Patients without cachexia at diagnosis were significantly more likely to develop substantial post-diagnosis weight loss from pre-diagnosis use groups of glucocorticoids (OR= 1.452; 95% CI=1.065, 1.979; P=0.0183) or NSAIDs (OR=1.411; 95% CI=1.082, 1.840; P=0.011).

Conclusions

Our findings suggest a protective effect of prior anti-inflammatory medications, primarily NSAIDs, against manifestations of the cachexia phenotype at cancer diagnosis. These observations support further exploration of potential therapeutic benefits from anti-inflammatory medications early in cancer management.

Mitogen-activated protein kinase kinase 7 in inflammatory, cancer, and neurological diseases

Stress-activated mitogen-activated protein kinase kinase 7 (MKK7) is a member of the dual-specificity mitogen-activated protein kinase family. In the human body, MKK7 controls essential physiological processes, including but not limited to proliferation and differentiation in multiple tissues and organs. MKK7, along with the MKK4 pathway, has been implicated in stress-activated activities and biological events that are mediated by c-Jun N-terminal kinase (JNK) signaling. Although numerous studies have been performed to identify the role of JNK in multiple biological processes, there are limited publications that focus on dissecting the independent role of MKK7. Recent research findings have spurred testing via in vivo genetically deficient models, uncovering previously undocumented JNK-independent functions of MKK7. Here we discuss both JNK-dependent and-independent functions of MKK7 in vivo. This review summarizes the role of MKK7 in inflammation, cytokine production, cancer, and neurological diseases.

Hilaire C, Schulz E, Kröller-Schön S, Keaney JF. PGC1α Regulates the Endothelial Response to Fluid Shear Stress via Telomerase Reverse Transcriptase Control of Heme Oxygenase-1

OBJECTIVE

Fluid shear stress (FSS) is known to mediate multiple phenotypic changes in the endothelium. Laminar FSS (undisturbed flow) is known to promote endothelial alignment to flow, which is key to stabilizing the endothelium and rendering it resistant to atherosclerosis and thrombosis. The molecular pathways responsible for endothelial responses to FSS are only partially understood. In this study, we determine the role of PGC1α (peroxisome proliferator gamma coactivator-1α)-TERT (telomerase reverse transcriptase)-HMOX1 (heme oxygenase-1) during shear stress in vitro and in vivo. Approach and Results: Here, we have identified PGC1α as a flow-responsive gene required for endothelial flow alignment in vitro and in vivo. Compared with oscillatory FSS (disturbed flow) or static conditions, laminar FSS (undisturbed flow) showed increased PGC1α expression and its transcriptional coactivation. PGC1α was required for laminar FSS-induced expression of TERT in vitro and in vivo via its association with ERRα(estrogen-related receptor alpha) and KLF (Kruppel-like factor)-4 on the TERT promoter. We found that TERT inhibition attenuated endothelial flow alignment, elongation, and nuclear polarization in response to laminar FSS in vitro and in vivo. Among the flow-responsive genes sensitive to TERT status, HMOX1 was required for endothelial alignment to laminar FSS.

CONCLUSIONS

These data suggest an important role for a PGC1α-TERT-HMOX1 axis in the endothelial stabilization response to laminar FSS.

c-Jun N-terminal kinase (JNK) signaling contributes to cystic burden in polycystic kidney disease

Polycystic kidney disease is an inherited degenerative disease in which the uriniferous tubules are replaced by expanding fluid-filled cysts that ultimately destroy organ function. Autosomal dominant polycystic kidney disease (ADPKD) is the most common form, afflicting approximately 1 in 1,000 people. It primarily is caused by mutations in the transmembrane proteins polycystin-1 (Pkd1) and polycystin-2 (Pkd2). The most proximal effects of Pkd mutations leading to cyst formation are not known, but pro-proliferative signaling must be involved for the tubule epithelial cells to increase in number over time. The c-Jun N-terminal kinase (JNK) pathway promotes proliferation and is activated in acute and chronic kidney diseases. Using a mouse model of cystic kidney disease caused by Pkd2 loss, we observe JNK activation in cystic kidneys and observe increased nuclear phospho c-Jun in cystic epithelium. Genetic removal of Jnk1 and Jnk2 suppresses the nuclear accumulation of phospho c-Jun, reduces proliferation and reduces the severity of cystic disease. While Jnk1 and Jnk2 are thought to have largely overlapping functions, we find that Jnk1 loss is nearly as effective as the double loss of Jnk1 and Jnk2. Jnk pathway inhibitors are in development for neurodegeneration, cancer, and fibrotic diseases. Our work suggests that the JNK pathway should be explored as a therapeutic target for ADPKD.

Autosomal dominant polycystic kidney disease is a leading cause of end stage renal disease requiring dialysis or kidney transplant. During disease development, the cells lining the kidney tubules proliferate. This proliferation transforms normally small diameter tubules into fluid-filled cysts that enlarge with time, eventually destroying all kidney function. Despite decades of research, polycystic kidney disease remains incurable. Furthermore, the precise signaling events involved in cyst initiation and growth remain unclear. The c-Jun N-terminal kinase (JNK), is a major pathway regulating cellular proliferation and differentiation but its importance to polycystic kidney disease was not known. We show that JNK activity is elevated in cystic kidneys and that reducing JNK activity decreases cyst growth pointing to JNK inhibition as a therapeutic strategy for treating polycystic kidney disease.

Mitogen Kinase Kinase (MKK7) Controls Cytokine Production In Vitro and In Vivo in Mice

Mitogen kinase kinase 4 (MKK4) and mitogen kinase kinase 7 (MKK7) are members of the MAP2K family that can activate downstream mitogen-activated protein kinases (MAPKs). MKK4 has been implicated in the activation of both c-Jun N-terminal kinase (JNK) and p38 MAPK, while MKK7 has been reported to activate only JNK in response to different stimuli. The stimuli, as well as the cell type determine which MAP2K member will mediate a given response. In various cell types, MKK7 contributes to the activation of downstream MAPKs, JNK, which is known to regulate essential cellular processes, such as cell death, differentiation, stress response, and cytokine secretion. Previous studies have also implicated the role of MKK7 in stress signaling pathways and cytokine production. However, little is known about the degree to which MKK4 and MKK7 contribute to innate immune responses in macrophages or during inflammation in vivo. To address this question and to elucidate the role of MKK4 and MKK7 in macrophage and in vivo, we developed MKK4- and MKK7-deficient mouse models with tamoxifen-inducible Rosa26 CreERT. This study reports that MKK7 is required for JNK activation both in vitro and in vivo. Additionally, we demonstrated that MKK7 in macrophages is necessary for lipopolysaccharide (LPS)-induced cytokine production, M1 polarization, and migration, which appear to be a major contributor to the inflammatory response in vivo. Conversely, MKK4 plays a significant, but minor role in cytokine production in vivo.

Vav2 is required for Netrin-1 receptor-class-specific spinal motor axon guidance

BACKGROUND

Proper guidance of neuronal axons to their targets is required to assemble neural circuits during the development of the nervous system. However, the mechanism by which the guidance of axonal growth cones is regulated by specific intermediaries activated by receptor signaling pathways to mediate cytoskeleton dynamics is unclear. Vav protein members have been proposed to mediate this process, prompting us to investigate their role in the limb selection of the axon trajectory of spinal lateral motor column (LMC) neurons.

RESULTS

We found Vav2 and Vav3 expression in LMC neurons when motor axons grew into the limb. Vav2, but not Vav3, loss-of-function perturbed LMC pathfinding, while Vav2 gain-of-function exhibited the opposite effects, demonstrating that Vav2 plays an important role in motor axon growth. Vav2 knockdown also attenuated the redirectional phenotype of LMC axons induced by Dcc, but not EphA4, in vivo and lateral LMC neurite growth preference to Netrin-1 in vitro. This study showed that Vav2 knockdown and ectopic nonphosphorylable Vav2 mutant expression abolished the Src-induced stronger growth preference of lateral LMC neurites to Netrin-1, suggesting that Vav2 is downstream of Src in this context.

CONCLUSIONS

Vav2 is essential for Netrin-1-regulated LMC motor axon pathfinding through Src interaction.

Bioinformatic analysis of RHO family of GTPases identifies RAC1 pharmacological inhibition as a new therapeutic strategy for hepatocellular carcinoma

OBJECTIVE

The RHO family of GTPases, particularly RAC1, has been linked with hepatocarcinogenesis, suggesting that their inhibition might be a rational therapeutic approach. We aimed to identify and target deregulated RHO family members in human hepatocellular carcinoma (HCC).

DESIGN

We studied expression deregulation, clinical prognosis and transcription programmes relevant to HCC using public datasets. The therapeutic potential of RAC1 inhibitors in HCC was study in vitro and in vivo. RNA-Seq analysis and their correlation with the three different HCC datasets were used to characterise the underlying mechanism on RAC1 inhibition. The therapeutic effect of RAC1 inhibition on liver fibrosis was evaluated.

RESULTS

Among the RHO family of GTPases we observed that RAC1 is upregulated, correlates with poor patient survival, and is strongly linked with a prooncogenic transcriptional programme. From a panel of novel RAC1 inhibitors studied, 1D-142 was able to induce apoptosis and cell cycle arrest in HCC cells, displaying a stronger effect in highly proliferative cells. Partial rescue of the RAC1-related oncogenic transcriptional programme was obtained on RAC1 inhibition by 1D-142 in HCC. Most importantly, the RAC1 inhibitor 1D-142 strongly reduce tumour growth and intrahepatic metastasis in HCC mice models. Additionally, 1D-142 decreases hepatic stellate cell activation and exerts an anti-fibrotic effect in vivo.

CONCLUSIONS

The bioinformatics analysis of the HCC datasets, allows identifying RAC1 as a new therapeutic target for HCC. The targeted inhibition of RAC1 by 1D-142 resulted in a potent antitumoural effect in highly proliferative HCC established in fibrotic livers.

Adjunctive Raloxifene and Isradipine Improve Cognitive Functioning in Patients With Schizophrenia: A Pilot Study

BACKGROUND

Cognitive impairment is the most important feature of schizophrenia leading to severe functional disability. To identify pathways that improve pathophysiological neurocognition in schizophrenia is a current challenge for the development of goal-directed clinical interventions. In the present study, we investigated the effects of raloxifene (a selective estrogen modulator) and isradipine (a voltage-gated L-type calcium channel blocker) on cognitive deficits in patients with schizophrenia.

METHOD

We designed a double-blind, randomized, parallel, placebo-controlled trial. We randomized 60 patients with schizophrenia into 3 groups including isradipine 5 mg, raloxifine 60 mg, and placebo for 6 consequent weeks, all in the same shape capsules, 2 times a day, along with treatment as usual. The initial and final results of blood tests, electrocardiograms, and cognitive tests in specific domains, such as attention, processing speed, executive function, and verbal memory were evaluated.

RESULTS

Our findings revealed a remarkable association between adjunctive raloxifene treatment and the alleviation of verbal memory deficits. Isradipine treatment significantly improved the verbal memory and attention dysfunction in some variables of the Stroop test, compared with the placebo. However, no effect was observed in processing speed and executive function deficits.

CONCLUSIONS

To the best of our knowledge, this study provides the first evidence that isradipine is a novel therapy option improving verbal memory and attention, both related to its activity in the hippocampus and the cerebellum. Further investigations are necessary to elucidate the mechanisms of action for both drugs in schizophrenia.

A systems-based analysis to explore the multiple mechanisms of Shan Zha for treating human diseases

Shan Zha has garnered increasing attention in the field of functional foods and medicines due to its widely reported healing effects. However, the potential mechanisms of Shan Zha for human health benefits have not been fully interpreted. Therefore, in the current study, a systems-based method that integrates ADME evaluation, target fishing, gene ontology enrichment analysis, network pharmacology, and pathway analysis is proposed to clarify the underlying pharmacological mechanisms of Shan Zha. As a result, 45 active components of Shan Zha that interacted with 161 protein targets were screened and identified. Moreover, gene ontology enrichment, network and pathway analysis indicated that Shan Zha is beneficial for the treatment of cardiovascular system diseases, digestive system diseases, immune system diseases, inflammatory diseases, cancer, and other diseases through multiple mechanisms. Our study not only proposed an integrated method to comprehensively elucidate the complicated mechanisms of Shan Zha for the treatment of various disorders at the system level, but also provided a reference approach for the mechanistic research of other functional foods.

Ribosome Collisions Trigger General Stress Responses to Regulate Cell Fate

Problems arising during translation of mRNAs lead to ribosome stalling and collisions that trigger a series of quality control events. However, the global cellular response to ribosome collisions has not been explored. Here, we uncover a function for ribosome collisions in signal transduction. Using translation elongation inhibitors and general cellular stress conditions, including amino acid starvation and UV irradiation, we show that ribosome collisions activate the stress-activated protein kinase (SAPK) and GCN2-mediated stress response pathways. We show that the MAPKKK ZAK functions as the sentinel for ribosome collisions and is required for immediate early activation of both SAPK (p38/JNK) and GCN2 signaling pathways. Selective ribosome profiling and biochemistry demonstrate that although ZAK generally associates with elongating ribosomes on polysomal mRNAs, it specifically auto-phosphorylates on the minimal unit of colliding ribosomes, the disome. Together, these results provide molecular insights into how perturbation of translational homeostasis regulates cell fate.

Rac1 Inhibition Via Srgap2 Restrains Inflammatory Osteoclastogenesis and Limits the Clastokine, SLIT3

The Rac1-specific guanosine triphosphatase (GTPase)-activating protein Slit-Robo GAP2 (Srgap2) is dramatically upregulated during RANKL-induced osteoclastogenesis. Srgap2 interacts with the cell membrane to locally inhibit activity of Rac1. In this study, we determined the role of Srgap2 in the myeloid lineage on bone homeostasis and the osteoclastic response to TNFα treatment. The bone phenotype of mice specifically lacking Srgap2 in the myeloid lineage (Srgap2 ^f/f :LysM-Cre; Srgap2 conditional knockout [cKO]) was investigated using histomorphometric analysis, in vitro cultures and Western blot analysis. Similar methods were used to determine the impact of TNFα challenge on osteoclast formation in Srgap2 cKO mice. Bone parameters in male Srgap2 cKO mice were unaffected. However, female cKO mice displayed higher trabecular bone volume due to increased osteoblast surface and bone formation rate, whereas osteoclastic parameters were unaltered. In vitro, cells from Srgap2 cKO had strongly enhanced Rac1 activation, but RANKL-induced osteoclast formation was unaffected. In contrast, conditioned medium from Srgap2 cKO osteoclasts promoted osteoblast differentiation and had increased levels of the bone anabolic clastokine SLIT3, providing a possible mechanism for increased bone formation in vivo. Rac1 is rapidly activated by the inflammatory cytokine TNFα. Supracalvarial injection of TNFα caused an augmented osteoclastic response in Srgap2 cKO mice. In vitro, cells from Srgap2 cKO mice displayed increased osteoclast formation in response to TNFα. We conclude that Srgap2 plays a prominent role in limiting osteoclastogenesis during inflammation through Rac1, and restricts expression of the paracrine clastokine SLIT3, a positive regulator of bone formation. © 2019 American Society for Bone and Mineral Research.

Therapeutic potential of targeting mixed lineage kinases in cancer and inflammation

Dysregulation of intracellular signaling pathways is a key attribute of diseases associated with chronic inflammation, including cancer. Mitogen activated protein kinases have emerged as critical conduits of intracellular signal transmission, yet due to their ubiquitous roles in cellular processes, their direct inhibition may lead to undesired effects, thus limiting their usefulness as therapeutic targets. Mixed lineage kinases (MLKs) are mitogen-activated protein kinase kinase kinases (MAP3Ks) that interact with scaffolding proteins and function upstream of p38, JNK, ERK, and NF-kappaB to mediate diverse cellular signals. Studies involving gene silencing, genetically engineered mouse models, and small molecule inhibitors suggest that MLKs are critical in tumor progression as well as in inflammatory processes. Recent advances indicate that they may be useful targets in some types of cancer and in diseases driven by chronic inflammation including neurodegenerative diseases and metabolic diseases such as nonalcoholic steatohepatitis. This review describes existing MLK inhibitors, the roles of MLKs in various aspects of tumor progression and in the control of inflammatory processes, and the potential for therapeutic targeting of MLKs.

Neural JNK3 regulates blood flow recovery after hindlimb ischemia in mice via an Egr1/Creb1 axis

Diseases related to impaired blood flow such as peripheral artery disease (PAD) impact nearly 10 million people in the United States alone, yet patients with clinical manifestations of PAD (e.g., claudication and limb ischemia) have limited treatment options. In ischemic tissues, stress kinases such as c-Jun N-terminal kinases (JNKs), are activated. Here, we show that inhibition of the JNK3 (Mapk10) in the neural compartment strikingly potentiates blood flow recovery from mouse hindlimb ischemia. JNK3 deficiency leads to upregulation of growth factors such as Vegfa, Pdgfb, Pgf, Hbegf and Tgfb3 in ischemic muscle by activation of the transcription factors Egr1/Creb1. JNK3 acts through Forkhead box O3 (Foxo3a) to suppress the activity of Egr1/Creb1 transcription regulators in vitro. In JNK3-deficient cells, Foxo3a is suppressed which leads to Egr1/Creb1 activation and upregulation of downstream growth factors. Collectively, these data suggest that the JNK3-Foxo3a-Egr1/Creb1 axis coordinates the vascular remodeling response in peripheral ischemia.

Stress kinases are activated in peripheral ischemic tissues in the presence of vascular diseases. Here the authors show that inhibition of the neural JNK3 kinase improves recovery from hind limb ischemia in animals through activation of the transcription factors Egr1/Creb1 and upregulation of growth factors.

High-Throughput Screening Identifies Mixed-Lineage Kinase 3 as a Key Host Regulatory Factor in Zika Virus Infection

The Zika virus (ZIKV) life cycle involves multiple steps and requires interactions with host factors. However, the inability to systematically identify host regulatory factors for ZIKV has hampered antiviral development and our understanding of pathogenicity. Here, using a bioactive compound library with 2,659 small molecules, we applied a high-throughput and imaging-based screen to identify host factors that modulate ZIKV infection. The screen yielded hundreds of hits that markedly inhibited or potentiated ZIKV infection in SNB-19 glioblastoma cells. Among the hits, URMC-099, a mixed-lineage kinase 3 (MLK3) inhibitor, significantly facilitated ZIKV replication in both SNB-19 cells and the neonatal mouse brain. Using gene silencing and overexpression, we further confirmed that MLK3 was a host restriction factor against ZIKV. Mechanistically, MLK3 negatively regulated ZIKV replication through induction of the inflammatory cytokines interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha (TNF-α), and monocyte chemoattractant protein 1 (MCP-1) but did not modulate host interferon-related pathways. Importantly, ZIKV activated the MLK3/MKK7/Jun N-terminal protein kinase (JNK) pathway in both SNB-19 cells and neonatal mouse brain. Together, these findings reveal a critical role for MLK3 in regulating ZIKV infection and facilitate the development of anti-ZIKV therapeutics by providing a number of screening hits.IMPORTANCE Zika fever, an infectious disease caused by the Zika virus (ZIKV), normally results in mild symptoms. Severe infection can cause Guillain-Barré syndrome in adults and birth defects, including microcephaly, in newborns. Although ZIKV was first identified in Uganda in 1947 in rhesus monkeys, a widespread epidemic of ZIKV infection in South and Central America in 2015 and 2016 raised major concerns. To date, there is no vaccine or specific medicine for ZIKV. The significance of our research is the systematic discovery of small molecule candidates that modulate ZIKV infection, which will allow the development of antiviral therapeutics. In addition, we identified MLK3, a key mediator of host signaling pathways that can be activated during ZIKV infection and limits virus replication by inducing multiple inflammatory cytokines. These findings broaden our understanding of ZIKV pathogenesis.

The second generation mixed lineage kinase-3 (MLK3) inhibitor CLFB-1134 protects against neurotoxin-induced nigral dopaminergic neuron loss

Dopaminergic neurons express mixed lineage kinases which regulate the expression of cell death genes. In Parkinson's disease, cell death via apoptosis is prevalent, and previous work testing mixed lineage kinase inhibitors in animal models suggested the inhibitors had some neuroprotective potential. CLFB-1134 is a new, brain-penetrant inhibitor specific for MLK3, tested here in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of dopaminergic depletion and nigral neuron death in mice. After ensuring that treatment with CLFB-1134 did not alter conversion of MPTP to MPP+, we demonstrated CLFB-1134's inhibition of MLK3 and neuroprotective efficacy. Specifically we evaluated the integrity of the nigrostriatal dopamine system following MPTP by assessing protein expression, high performance liquid chromatography, and immunohistology with stereology. We found that CLFB-1134 achieves protection of striatal dopaminergic terminals and nigral cell bodies when dosed simultaneously or following MPTP treatment. By preventing phosphorylation of JNK and other downstream targets of MLK3, CLFB-1134 protects against the neurotoxin MPTP. Inhibition of MLK3 may be a valid target for future work investigating treatment of Parkinson's disease.

JNK and cardiometabolic dysfunction

Cardiometabolic syndrome (CMS) describes the cluster of metabolic and cardiovascular diseases that are generally characterized by impaired glucose tolerance, intra-abdominal adiposity, dyslipidemia, and hypertension. CMS currently affects more than 25% of the world’s population and the rates of diseases are rapidly rising. These CMS conditions represent critical risk factors for cardiovascular diseases including atherosclerosis, heart failure, myocardial infarction, and peripheral artery disease (PAD). Therefore, it is imperative to elucidate the underlying signaling involved in disease onset and progression. The c-Jun N-terminal Kinases (JNKs) are a family of stress signaling kinases that have been recently indicated in CMS. The purpose of this review is to examine the in vivo implications of JNK as a potential therapeutic target for CMS. As the constellation of diseases associated with CMS are complex and involve multiple tissues and environmental triggers, carefully examining what is known about the JNK pathway will be important for specificity in treatment strategies.

Transcriptomic responses of Caco-2 cells to Lactobacillus rhamnosus GG and Lactobacillus plantarum J26 against oxidative stress

Oxidative stress is the basic reason for aging and age-related diseases. In this study, we investigated the protective effect of 2 strains of lactic acid bacteria (LAB), Lactobacillus rhamnosus GG and L. plantarum J26, against oxidative stress in Caco-2 cells, and gave an overview of the mechanisms of lactic acid bacteria antioxidant activity using digital gene expression profiling. The 2 LAB strains provided significant protection against hydrogen peroxide (H₂O₂)-induced reduction in superoxide dismutase activity and increase in glutathione peroxidase activity in Caco-2 cells. However, inactive bacteria had little effect on alleviating oxidation stress in Caco-2 cells. Eight genes related to oxidative stress-FOSB, TNF, PPP1R15A, NUAK2, ATF3, TNFAIP3, EGR2, and FBN2-were significantly upregulated in H₂O₂-induced Caco-2 cells compared with untreated Caco-2 cells. After incubation of the H₂O₂-induced Caco-2 cells with L. rhamnosus GG and L. plantarum J26, 5 genes (TNF, EGR2, NUAK2, FBN2, and TNFAIP3) and 2 genes (NUAK2 and FBN2) were downregulated, respectively. In addition, the Kyoto Encyclopedia of Genes and Genomes indicated that some signaling pathways associated with inflammation, immune response, and apoptosis, such as Janus kinase/signal transducers and activators of transcription (Jak-STAT), mitogen-activated protein kinase (MAPK), nuclear factor-κB, and tumor necrosis factor, were all negatively modulated by the 2 strains, especially L. rhamnosus GG. In this paper, we reveal the mechanism of LAB in relieving oxidative stress and provide a theoretical basis for the rapid screening and evaluation of new LAB resources.

Endothelial permeability, LDL deposition, and cardiovascular risk factors-a review

Early atherosclerosis features functional and structural changes in the endothelial barrier function that affect the traffic of molecules and solutes between the vessel lumen and the vascular wall. Such changes are mechanistically related to the development of atherosclerosis. Proatherogenic stimuli and cardiovascular risk factors, such as dyslipidaemias, diabetes, obesity, and smoking, all increase endothelial permeability sharing a common signalling denominator: an imbalance in the production/disposal of reactive oxygen species (ROS), broadly termed oxidative stress. Mostly as a consequence of the activation of enzymatic systems leading to ROS overproduction, proatherogenic factors lead to a pro-inflammatory status that translates in changes in gene expression and functional rearrangements, including changes in the transendothelial transport of molecules, leading to the deposition of low-density lipoproteins (LDL) and the subsequent infiltration of circulating leucocytes in the intima. In this review, we focus on such early changes in atherogenesis and on the concept that proatherogenic stimuli and risk factors for cardiovascular disease, by altering the endothelial barrier properties, co-ordinately trigger the accumulation of LDL in the intima and ultimately plaque formation.

Broad Spectrum Mixed Lineage Kinase Type 3 Inhibition and HIV-1 Persistence in Macrophages

Mixed lineage kinases (MLKs) are a group of serine-threonine kinases that evolved in part to respond to endogenous and exogenous insults that result in oxidative stress and pro-inflammatory responses from innate immune cells. Human immunodeficiency virus type 1 (HIV-1) thrives in these conditions and is associated with the development of associated neurocognitive disorders (HAND). As part of a drug discovery program to identify new therapeutic strategies for HAND, we created a library of broad spectrum MLK inhibitors with drug-like properties. Serendipitously, the lead compound, URMC-099 has proved useful not only in reversing damage to synaptic architecture in models of HAND, but also serves to restore autophagy as a protective response when given in concert with nanoformulated antiretroviral therapy (nanoART) in persistently infected macrophages. These findings are reviewed in the context of MLK3 biology and cellular signaling pathways relevant to new HIV-1 therapies. Graphical abstract.

Tumor Necrosis Factor-Alpha as Differential Diagnostic Marker for Patients with Fever of Unknown Origin

Febrile conditions of unidentified origin are still unknown in modern medicine despite the development of diagnostic procedures. There are various agents of long-term temperature encompassing numerous infectious or non-infectious diseases.

The aim of this study was to determine if there was a statistically significant difference in the values of proinflammatory cytokines (IL-1, TNFα, IL-6) in patients who meet the criteria for febrile conditions of unidentified origin, between the group of infectious, malignant, rheumatic, “other” diseases and undiagnosed patients.

The study was conducted in the Immunology laboratory of the Center for Molecular Medicine and Stem Cells Research of the Faculty of Medical Sciences in Kragujevac. Blood samples were taken from patients tested at the Clinic for Infectious Diseases, of the Clinical Center of Kragujevac, in the period from 2014 to 2016. The study included 70 patients.

The measured values of the level of TNFα showed significantly higher values in a group of malignant diseases than in the group of infectious diseases, while the values of IL-1 and IL-6 did not show statistical significance.

TNFα can improve diagnosing in case of patients with an unknown febrile condition, which can shorten the length of the hospital stay and reduce the volume of performance of diagnostic procedures.

The role of TCPTP on leptin effects on astrocyte morphology

Leptin and LPS has been implicated in the development of hypothalamic astrogliosis in rodents. Astrocytes, which are interconnected by gap junction proteins, have emerged as important players in the control of energy homeostasis exerted by the hypothalamus. To investigate the hypothesis of action of T-cell protein tyrosine phosphatase (TCPTP) on the astrocyte morphology, astrocytes from the hypothalamus of one-day-old rats were stimulated with leptin and LPS (used as a positive control). Leptin and LPS induced a marked increase in astrocyte size, an increase in Ptpn2 (TCPTP gene) and gap junction alpha-1 protein, - Gja1 (connexin 43 - CX43 gene) mRNA expression and a decrease in gap junction protein, alpha 6 - Gja6 (CX30 gene) mRNA expression. Remarkably, these effects on astrocytes morphology and connexins were prevented by Ptpn2 siRNA. Astrocytes are known to produce cytokines; here we show that TCPTP acts as an important regulator of the cytokines and it possesses a reciprocal interplay with protein tyrosine phosphatase 1B (PTP1B). Our findings demonstrate that leptin and LPS alter astrocyte morphology by increasing TCPTP, which in turn modulates connexin 30 (CX30) and connexin 43 (CX43) expression. TCPTP and PTP1B seem to act in the regulation of cytokine production in astrocytes.

The Role of Tumor Necrosis Factor α in the Biology of Uterine Fibroids and the Related Symptoms

Uterine fibroids (UFs) are the most common benign tumors of the female genital tract. The incidence of UFs has been estimated at 25⁻80% depending on selected population. The pathophysiology of UFs remains poorly understood. The transformation of smooth muscle cells of the uterus into abnormal, immortal cells, capable of clonal division, is the main component of all pathways leading to UF tumor formation and tumor necrosis factor α (TNF-α) is believed to be one of the key factors in this field. TNF-α is a cell signaling protein involved in systemic inflammation and is one of the cytokines responsible for the acute phase reaction. This publication presents current data about the role of tumor necrosis factor α in the biology of UFs and the related symptoms. TNF-α is an extremely important cytokine associated with the biology of UFs, UF-related symptoms and complaints. Its concentration has been proven to be elevated in women with clinically symptomatic UFs. The presented data suggest the presence of an "inflammation-like" state in women with UFs where TNF-α is a potent inflammation inducer. The origin of numerous symptoms reported by women with UFs can be traced back to the TNF-α influence. Nevertheless, our knowledge on this subject remains limited and TNF-α dependent pathways in UF pathophysiology should be investigated further.

EspH Suppresses Erk by Spatial Segregation from CD81 Tetraspanin Microdomains

Enteropathogenic Escherichia coli (EPEC) belongs to a group of enteric human pathogens known as attaching-and-effacing (A/E) pathogens, which utilize a type III secretion system (T3SS) to translocate a battery of effector proteins from their own cytoplasm into host intestinal epithelial cells. Here we identified EspH to be an effector that prompts the recruitment of the tetraspanin CD81 to infection sites. EspH was also shown to be an effector that suppresses the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (Erk) signaling pathway at longer infection times. The inhibitory effect was abrogated upon deletion of the last 38 amino acids located at the C terminus of the protein. The efficacy of EspH-dependent Erk suppression was higher in CD81-deficient cells, suggesting that CD81 may act as a positive regulator of Erk, counteracting Erk suppression by EspH. EspH was found within CD81 microdomains soon after infection but was largely excluded from these domains at a later time. Based on our results, we propose a mechanism whereby CD81 is initially recruited to infection sites in response to EspH translocation. At a later stage, EspH moves out of the CD81 clusters to facilitate effective Erk inhibition. Moreover, EspH selectively inhibits the tumor necrosis factor alpha (TNF-α)-induced Erk signaling pathway. Since Erk and TNF-α have been implicated in innate immunity and cell survival, our studies suggest a novel mechanism by which EPEC suppresses these processes to promote its own colonization and survival in the infected gut.

A Protein Scaffold Coordinates SRC-Mediated JNK Activation in Response to Metabolic Stress

Obesity is a major risk factor for the development of metabolic syndrome and type 2 diabetes. How obesity contributes to metabolic syndrome is unclear. Free fatty acid (FFA) activation of a non-receptor tyrosine kinase (SRC)-dependent cJun NH₂-terminal kinase (JNK) signaling pathway is implicated in this process. However, the mechanism that mediates SRC-dependent JNK activation is unclear. Here, we identify a role for the scaffold protein JIP1 in SRC-dependent JNK activation. SRC phosphorylation of JIP1 creates phosphotyrosine interaction motifs that bind the SH2 domains of SRC and the guanine nucleotide exchange factor VAV. These interactions are required for SRC-induced activation of VAV and the subsequent engagement of a JIP1-tethered JNK signaling module. The JIP1 scaffold protein, therefore, plays a dual role in FFA signaling by coordinating upstream SRC functions together with downstream effector signaling by the JNK pathway.

Simvastatin and nanofibrous poly(l-lactic acid) scaffolds to promote the odontogenic potential of dental pulp cells in an inflammatory environment

In this study, we investigated the anti-inflammatory, odontogenic and pro-angiogenic effects of integrating simvastatin and nanofibrous poly(l-lactic acid) (NF-PLLA) scaffolds on dental pulp cells (DPCs). Highly porous NF-PLLA scaffolds that mimic the nanofibrous architecture of extracellular matrix were first fabricated, then seeded with human DPCs and cultured with 0.1 μM simvastatin and/or 10 μg/mL pro-inflammatory stimulator lipopolysaccharide (LPS). The gene expression of pro-inflammatory mediators (TNF-α, IL-1β and MMP-9 mRNA) and odontoblastic markers (ALP activity, calcium content, DSPP, DMP-1 and BMP-2 mRNA) were quantified after long-term culture in vitro. In addition, we evaluated the scaffold's pro-angiogenic potential after 24 h of in vitro co-culture with endothelial cells. Finally, we assessed the combined effects of simvastatin and NF-PLLA scaffolds in vivo using a subcutaneous implantation mouse model. The in vitro studies demonstrated that, compared with the DPC/NF-PLLA scaffold constructs cultured only with pro-inflammatory stimulator LPS, adding simvastatin significantly repress the expression of pro-inflammatory mediators. Treating LPS+ DPC/NF-PLLA constructs with simvastatin also reverted the negative effects of LPS on expression of odontoblastic markers in vitro and in vivo. Western blot analysis demonstrated that these effects were related to a reduction in NFkBp65 phosphorylation and up-regulation of PPARγ expression, as well as to increased phosphorylation of pERK1/2 and pSmad1, mediated by simvastatin on LPS-stimulated DPCs. The DPC/NF-PLLA constructs treated with LPS/simvastatin also led to an increase in vessel-like structures, correlated with increased VEGF expression in both DPSCs and endothelial cells. Therefore, the combination of low dosage simvastatin and NF-PLLA scaffolds appears to be a promising strategy for dentin regeneration with inflamed dental pulp tissue, by minimizing the inflammatory reaction and increasing the regenerative potential of resident stem cells.

STATEMENT OF SIGNIFICANCE

The regeneration potential of stem cells is dependent on their microenvironment. In this study, we investigated the effect of the microenvironment of dental pulp stem cells (DPSCs), including 3D structure of a macroporous and nanofibrous scaffold, the inflammatory stimulus lipopolysaccharide (LPS) and a biological molecule simvastatin, on their regenerative potential of mineralized dentin tissue. The results demonstrated that LPS upregulated inflammatory mediators and suppressed the odontogenic potential of DPSCs. Known as a lipid-lowing agent, simvastatin was excitingly found to repress the expression of pro-inflammatory mediators, up-regulate odontoblastic markers, and exert a pro-angiogenic effect on endothelial cells, resulting in enhanced vascularization and mineralized dentin tissue regeneration in a biomimetic 3D tissue engineering scaffold. This novel finding is significant for the fields of stem cells, inflammation and dental tissue regeneration.

Stress-activated MAPKs and CRM1 regulate the subcellular localization of Net1A to control cell motility and invasion

The neuroepithelial cell transforming gene 1A (Net1A, an isoform of Net1) is a RhoA subfamily guanine nucleotide exchange factor (GEF) that localizes to the nucleus in the absence of stimulation, preventing it from activating RhoA. Once relocalized in the cytosol, Net1A stimulates cell motility and extracellular matrix invasion. In the present work, we investigated mechanisms responsible for the cytosolic relocalization of Net1A. We demonstrate that inhibition of MAPK pathways blocks Net1A relocalization, with cells being most sensitive to JNK pathway inhibition. Moreover, activation of the JNK or p38 MAPK family pathway is sufficient to elicit Net1A cytosolic localization. Net1A relocalization stimulated by EGF or JNK activation requires nuclear export mediated by CRM1. JNK1 (also known as MAPK8) phosphorylates Net1A on serine 52, and alanine substitution at this site prevents Net1A relocalization caused by EGF or JNK activation. Glutamic acid substitution at this site is sufficient for Net1A relocalization and results in elevated RhoA signaling to stimulate myosin light chain 2 (MLC2, also known as MYL2) phosphorylation and F-actin accumulation. Net1A S52E expression stimulates cell motility, enables Matrigel invasion and promotes invadopodia formation. These data highlight a novel mechanism for controlling the subcellular localization of Net1A to regulate RhoA activation, cell motility, and invasion.

Perturbation-response genes reveal signaling footprints in cancer gene expression

Aberrant cell signaling can cause cancer and other diseases and is a focal point of drug research. A common approach is to infer signaling activity of pathways from gene expression. However, mapping gene expression to pathway components disregards the effect of post-translational modifications, and downstream signatures represent very specific experimental conditions. Here we present PROGENy, a method that overcomes both limitations by leveraging a large compendium of publicly available perturbation experiments to yield a common core of Pathway RespOnsive GENes. Unlike pathway mapping methods, PROGENy can (i) recover the effect of known driver mutations, (ii) provide or improve strong markers for drug indications, and (iii) distinguish between oncogenic and tumor suppressor pathways for patient survival. Collectively, these results show that PROGENy accurately infers pathway activity from gene expression in a wide range of conditions.

Upregulation of Matrix Metalloproteinase-9 in Primary Cultured Rat Astrocytes Induced by 2-Chloroethanol Via MAPK Signal Pathways

2-Chloroethanol (2-CE) is one of the reactive metabolites of 1,2-DCE in vivo, which might contribute to brain edema formation induced by 1,2-dichloroethane (1,2-DCE) poisoning. Thus, the purpose of this study was to explore the roles of mitogen-activated protein kinase (MAPK) signal pathways in upregulation of matrix metalloproteinase-9 (MMP-9) in 2-CE exposed rat astrocytes. Expression of p38 MAPK (p38), extracellular signal regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK) and MMP-9 at both protein and gene levels in rat astrocytes were determined using western blot and real-time RT-PCR methods. The results showed that both protein and mRNA levels of MMP-9 in 2-CE exposed astrocytes significantly increased. Meanwhile, protein levels of phosphorylated p38 (p-p38), ERK1/2 (p-ERK1/2) and JNK1/2 (p-JNK1/2) in 2-CE exposed astrocytes also significantly increased. In addition, both protein and mRNA levels of MMP-9 significantly decreased in response to reduced protein levels of p-p38, p-ERK1/2 and p-JNK1/2 achieved by supplement with their specific inhibitors, indicating that activation of MAPK signal pathways might play an important role in upregulation of MMP-9 expression at the transcriptional level in 2-CE exposed astrocytes. Furthermore, since pretreatment of n-acetyl-l-cysteine (NAC), a powerful antioxidant amino acid, could attenuate the elevated levels of MMP-9, p-p38, p-ERK2 and p-JNK1/2 in 2-CE exposed astrocytes, activation of MAPK signal pathways in 2-CE exposed astrocytes could be mediated partially by reactive oxygen species (ROS), which was most likely generated in the metabolism of 2-CE.

TNFα alters occludin and cerebral endothelial permeability: Role of p38MAPK

Occludin is a key tight junction (TJ) protein in cerebral endothelial cells (CECs) playing an important role in modulating blood-brain barrier (BBB) functions. This protein (65kDa) has been shown to engage in many signaling pathways and phosphorylation by both tyrosine and threonine kinases. Despite yet unknown mechanisms, pro-inflammatory cytokines and endotoxin (lipopolysaccharides, LPS) may alter TJ proteins in CECs and BBB functions. Here we demonstrate the responses of occludin in an immortalized human cerebral endothelial cell line (hCMEC/D3) to stimulation by TNFα (10 ng/mL), IL-1β (10 ng/mL) and LPS (100 ng/mL). Exposing cells to TNFα resulted in a rapid and transient upward band-shift of occludin, suggesting of an increase in phosphorylation. Exposure to IL-1β produced significantly smaller effects and LPS produced almost no effects on occludin band-shift. TNFα also caused transient stimulation of p38MAPK and ERK1/2 in hCMEC/D3 cells, and the occludin band-shift induced by TNFα was suppressed by SB202190, an inhibitor for p38MAPK, and partly by U0126, the MEK1/2-ERK1/2 inhibitor. Cells treated with TNFα and IL-1β but not LPS for 24 h resulted in a significant (p < 0.001) decrease in the expression of occludin, and the decrease could be partially blocked by SB202190, the inhibitor for p38MAPK. Treatment with TNFα also altered cell morphology and enhanced permeability of the CEC layer as measured by the FITC-dextran assay and the trans-endothelial electrical resistances (TEER). However, treatment with SB202190 alone could not effectively reverse the TNFα -induced morphology changes or the enhanced permeability changes. These results suggest that despite effects of TNFα on p38MAPK-mediated occludin phosphorylation and expression, these changes are not sufficient to avert the TNFα-induced alterations on cell morphology and permeability.

2-Chloroethanol Induced Upregulation of Matrix Metalloproteinase-2 in Primary Cultured Rat Astrocytes Via MAPK Signal Pathways

This study was to explore the mechanisms underlying 1,2-dichloroethane (1,2-DCE) induced brain edema by focusing on alteration of matrix metalloproteinase-2 (MMP-2) in rat astrocytes induced by 2-chloroethanol (2-CE), an intermediate metabolite of 1,2-DCE in vivo. Protein and mRNA levels of MMP-2, and the phosphorylated protein levels of p38 MAPK (p-p38), extracellular signal regulated protein kinase (p-ERK1/2) and c-Jun N-terminal kinase (p-JNK1/2) in astrocytes were examined by immunostaining, western blot or real-time RT-PCR analysis. Findings from this study disclosed that protein levels of MMP-2 were upregulated by 2-CE in astrocytes. Meanwhile, protein levels of p-p38, p-ERK1/2 and p-JNK1/2 were also increased apparently in the cells treated with 2-CE. Moreover, pretreatment of astrocytes with SB202190 (inhibitor of p38 MAPK), U0126 (inhibitor of ERK1/2) or SP600125 (inhibitor of JNK1/2) could suppress the upregulated expression of p-p38, p-ERK1/2, and p-JNK1/2. In response to suppressed protein levels of p-p38 and p-JNK1/2, the protein levels of MMP-2 also decreased significantly, indicating that activation of MAPK signal pathways were involved in the mechanisms underlying 2-CE-induced upregulation of MMP-2 expression.

Serum TNF-α levels in children with congenital heart disease undergoing cardiopulmonary bypass: A cohort study in China and a meta-analysis of the published literature

OBJECTIVE

To investigate the changes in tumor necrosis factor alpha (TNF-α) serum levels after cardiopulmonary bypass (CPB) in children with congenital heart disease (CHD), followed by a meta-analysis to analyze the clinical value of TNF-α in CPB.

METHODS

Our cohort study enrolled 67 CHD children, assigned into off-pump group (n=32) and CPB group (n=35). The TNF-α serum levels in two groups were detected by ELISA before the operation (T1), at the end of the operation (0 hour, T2), and after 24 hours of the operation (T3). For meta-analysis, literature search was conducted to identify published case-control articles about the changes of TNF-α serum levels with CPB of CHD.

RESULTS

The TNF-α levels in CPB group were lower than that in the off-pump group at T3 (P=.006). TNF-α level at T3 was significantly lower than that at T1 and T2 (all P<.05). Meta-analysis results further confirmed that the TNF-α levels of CHD children were dramatically decreased at T3 as compared to that at T1 and T2 (both P<.001).

CONCLUSION

The TNF-α serum levels showed a transient and dramatic decline after 24 hours of CPB, and it may act as an important biological indicator for monitoring the efficacy of CPB in CHD children.

Cell Signaling and Stress Responses

Stress-signaling pathways are evolutionarily conserved and play an important role in the maintenance of homeostasis. These pathways are also critical for adaptation to new cellular environments. The endoplasmic reticulum (ER) unfolded protein response (UPR) is activated by biosynthetic stress and leads to a compensatory increase in ER function. The JNK and p38 MAPK signaling pathways control adaptive responses to intracellular and extracellular stresses, including environmental changes such as UV light, heat, and hyperosmotic conditions, and exposure to inflammatory cytokines. Metabolic stress caused by a high-fat diet represents an example of a stimulus that coordinately activates both the UPR and JNK/p38 signaling pathways. Chronic activation of these stress-response pathways ultimately causes metabolic changes associated with obesity and altered insulin sensitivity. Stress-signaling pathways, therefore, represent potential targets for therapeutic intervention in the metabolic stress response and other disease processes.

Suppression of ischemia in arterial occlusive disease by JNK-promoted native collateral artery development

Arterial occlusive diseases are major causes of morbidity and mortality. Blood flow to the affected tissue must be restored quickly if viability and function are to be preserved. We report that disruption of the mixed-lineage protein kinase (MLK) - cJun NH2-terminal kinase (JNK) signaling pathway in endothelial cells causes severe blockade of blood flow and failure to recover in the murine femoral artery ligation model of hindlimb ischemia. We show that the MLK-JNK pathway is required for the formation of native collateral arteries that can restore circulation following arterial occlusion. Disruption of the MLK-JNK pathway causes decreased Dll4/Notch signaling, excessive sprouting angiogenesis, and defects in developmental vascular morphogenesis. Our analysis demonstrates that the MLK-JNK signaling pathway is a key regulatory mechanism that protects against ischemia in arterial occlusive disease.