Compromised MAPK signaling in human diseases: an update. Arch Toxicol. 2015;89:867-882. [PMID: 25690731 DOI: 10.1007/s00204-015-1472-2]

Expression and potential mechanism of metabolism-related genes and CRLS1 in non-small cell lung cancer

Cardiolipin (CL) is a phospholipid localized in the mitochondria, which is essential for mitochondrial structure and function. Human cardiolipin synthase 1 (CRLS1) is important in regulating phosphatidylglycerol (PG) remodeling and CL biosynthesis. However, the expression and distinct prognostic value of CRLS1 in neoplasms, including non-small cell lung cancer (NSCLC), is not well established. In the present study, the mRNA expression of CRLS1 was investigated using Oncomine analysis and the prognostic value was assessed using the Kaplan-Meier plotter database for patients with NSCLC. The results of the analyses indicated that the expression of CRLS1 in lung cancer was lower, compared with that in normal lung tissues. Notably, a high expression of CRLS1 was found to be associated with improved overall survival (OS) in all patients with NSCLC and lung adenocarcinoma (Ade). However, this was not observed in patients with squamous cell carcinoma (SCC). The results also demonstrated an association between the mRNA expression of CRLS1 and the clinicopathological parameters of patients with NSCLC, including sex, smoking status, tumor grade, clinical stage, lymph node status and chemotherapy. These results indicated that CRLS1 was associated with improved prognosis in patients with NSCLC, particularly at an early stage (T1N1M0). In addition, it was revealed that CRLS1 was co-expressed with well-known genes associated with metabolism using Gene Ontology term enrichment analysis. Kyoto Encyclopedia of Genes and Genomes pathway analysis also showed that tumor-related metabolism and the mitogen-activated protein kinase (MAPK) signaling pathways were enriched with CRLS1-co-expression genes. The results of the present study suggested that CRLS1 may be a novel tumor suppressor involved in regulating lipid and seleno-amino acid metabolism in the tumor microenvironment, and suppressing the MAPK signaling pathway during tumorigenesis and development. Comprehensive evaluation of the expression, prognosis and potential mechanism of CRLS1 is likely to promote an improved understanding of the complexity of the molecular biology of NSCLC.

miRNA-21 Expression in the Serum of Elderly Patients with Acute Myocardial Infarction

BACKGROUND The aims of this study were to examine the expression of miRNA-21 in the serum of elderly patients (>65 years) with acute myocardial infarction (AMI) and to investigate the potential role of serum miRNA-21 as a marker of early cardiac myocyte damage. MATERIAL AND METHODS Thirty-eight elderly patients with recent AMI, 27 elderly patients with unstable angina pectoris, and 25 healthy elderly individuals were included in the study. Serum miRNA-21 expression was determined following total RNA extraction and reverse-transcribed into cDNA, followed by reverse transcription-polymerase chain reaction (RT-PCR). Serum creatine kinase MB isoenzyme (CK-MB) and cardiac troponin I (cTnI) levels were analyzed by electrochemiluminescence. Apoptosis of human cardiac myocytes (HCM) was analyzed using fluorescence-activated cell sorting (FACS), and protein expression of caspase-3 was detected using Western blot. RESULTS Expression levels of miRNA-21 in the serum of elderly patients with AMI were positively correlated with serum levels of CK-MB (r=0.3683, P=0.0229) and cTnI (r=0.5128, P=0.009). Following tumor necrosis factor (TNF)-α induction, the apoptosis rates of HCM transfected with the miRNA-21 mimic short hairpin RNA (shRNA) were downregulated by 39.1% compared with control HCM cells, and protein expression of c-Jun N-terminal kinases (JNK) and p38 were unchanged (P>0.05); protein expression of p-JNK, p-p38 and caspase-3 were downregulated by 37.1%, 35.8%, and 36.0%, respectively. CONCLUSIONS Expression of miRNA-21 was upregulated in the serum of elderly patients with AMI, which inhibited TNF-a induced apoptosis in HCM by activating the JNK/p38/caspase-3 signaling pathway.

HOXC10 up-regulation promotes gastric cancer cell proliferation and metastasis through MAPK pathway

OBJECTIVE

As an important regulator of embryonic morphogenesis, homeodomain-containing gene 10 (HOXC10) has been found to promote progression of human cancers and its expression indicates poor survival outcome. However, very few studies are available on the role of HOXC10 in gastric carcinoma. Therefore, the aim of this study was to determine the role of HOXC10 in gastric cancer and the potential mechanism underlying its function for cancer biology.

METHODS

A primary gastric cancer mouse model was obtained via intra-gastric wall injection of gastric cancer cells and was used to evaluate the function of HOXC10 during gastric cancer progression in vivo. Immunohistochemistry was performed to visualize and measure HOXC10 protein expression in gastric cancer tissue. Cells were transfected with plasmids to increase the expression of HOXC10, and siRNA transfection was performed to suppress HOXC10 expression. Reverse transcription polymerase chain reaction (RT-PCR) and western blotting were utilized to measure mRNA and protein expression, respectively. Proliferation, migration, and invasion were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, wound healing assay, and matrigel invasion assay in vitro, respectively.

RESULTS

HOXC10 expression was significantly increased in gastric cancer tissues compared to matched normal tissues. HOXC10 up-regulation significantly increased tumor volumes in nude mice. Plasmid transfection significantly increased HOXC10 protein and mRNA expressions and effectively promoted cell proliferation. Moreover, HOXC10 up-regulation significantly promoted migration and invasion of gastric cancer cells. Mechanistic investigation showed that HOXC10 up-regulation significantly increased mRNA and protein expression of mitogen-activated protein kinase (MAPK) signaling related genes, including c-myc, c-jun and p53, while also modulating the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and P38 but not their total protein levels.

CONCLUSIONS

This study demonstrated the tight link between HOXC10 and gastric cancer cell proliferation and metastasis via involvement of the MAPK pathway.

Functional analyses of major cancer-related signaling pathways in Alzheimer's disease etiology

Alzheimer's disease (AD) is an aging-related neurodegenerative disease and accounts for majority of human dementia. The hyper-phosphorylated tau-mediated intracellular neurofibrillary tangle and amyloid β-mediated extracellular senile plaque are characterized as major pathological lesions of AD. Different from the dysregulated growth control and ample genetic mutations associated with human cancers, AD displays damage and death of brain neurons in the absence of genomic alterations. Although various biological processes predominately governing tumorigenesis such as inflammation, metabolic alteration, oxidative stress and insulin resistance have been associated with AD genesis, the mechanistic connection of these biological processes and signaling pathways including mTOR, MAPK, SIRT, HIF, and the FOXO pathway controlling aging and the pathological lesions of AD are not well recapitulated. Hence, we performed a thorough review by summarizing the physiological roles of these key cancer-related signaling pathways in AD pathogenesis, comprising of the crosstalk of these pathways with neurofibrillary tangle and senile plaque formation to impact AD phenotypes. Importantly, the pharmaceutical investigations of anti-aging and AD relevant medications have also been highlighted. In summary, in this review, we discuss the potential role that cancer-related signaling pathways may play in governing the pathogenesis of AD, as well as their potential as future targeted strategies to delay or prevent aging-related diseases and combating AD.

Identification of hub miRNA biomarkers for bladder cancer by weighted gene coexpression network analysis

Bladder cancer (BC) is a common urinary system tumor with high aggressiveness, and it results in relatively high mortality due to a lack of precise and suitable biomarkers. In this study, we applied the weighted gene coexpression network analysis method to miRNA expression data from BC patients, and screened for network modules associated with BC progression. Hub miRNAs were selected, followed by functional enrichment analyses of their target genes for the most closely related module. These hub miRNAs were found to be involved in several functional pathways including pathway in cancer, regulation of actin cytoskeleton, PI3K-Akt signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, Wnt signaling pathway, proteoglycans in cancer, focal adhesion and p53 signaling pathway via regulating target genes. Finally, their prognostic significance was tested using analyses of overall survival. A few novel prognostic miRNAs were identified based on expression profiles and related survival data. In conclusion, several miRNAs that were critical in BC initiation and progression have been identified in this study. These miRNAs, which may contribute to a comprehensive understanding of the pathogenesis of BC, could serve as potential biomarkers for BC prognosis or as new therapeutic targets.

JNK signaling pathway regulates sorbitol-induced Tau proteolysis and apoptosis in SH-SY5Y cells by targeting caspase-3

Growing evidence suggests that Diabetes Mellitus increases the risk of developing Alzheimer's disease. It is well known that hyperglycemia, a key feature of Diabetes Mellitus, may induce plasma osmolarity disturbances. Both hyperglycemia and hyperosmolarity promote the altered post-translational regulation of microtubule-associated protein Tau. Interestingly, abnormal hyperphosphorylation and cleavage of Tau have been proven to lead to the genesis of filamentous structures referred to as neurofibrillary tangles, the main pathological hallmark of Alzheimer's disease. We have previously described that hyperosmotic stress induced by sorbitol promotes Tau proteolysis and apoptosis in SH-SY5Y cells via caspase-3 activation. In order to gain insights into the regulatory mechanisms of such processes, in this work we explored the intracellular signaling pathways that regulate these events. We found that sorbitol treatment significantly enhanced the activation of conventional families of MAPK in SH-SY5Y cells. Tau proteolysis was completely prevented by JNK inhibition but not affected by either ERK1/2 or p38 MAPK blockade. Moreover, inhibition of JNK, but not ERK1/2 or p38 MAPK, efficiently prevented sorbitol-induced apoptosis and caspase-3 activation. In summary, we provide evidence that JNK signaling pathway is an upstream regulator of hyperosmotic stress-induced Tau cleavage and apoptosis in SH-SY5Y through the control of caspase-3 activation.

The analgesic effects of triptolide in the bone cancer pain rats via inhibiting the upregulation of HDACs in spinal glial cells

Background

Bone cancer pain (BCP) severely compromises the quality of life, while current treatments are still unsatisfactory. Here, we tested the antinociceptive effects of triptolide (T10), a substance with considerable anti-tumor efficacies on BCP, and investigated the underlying mechanisms targeting the spinal dorsal horn (SDH).

Methods

Intratibial inoculation of Walker 256 mammary gland carcinoma cells was used to establish a BCP model in rats. T10 was intrathecally injected, and mechanical allodynia was tested by measuring the paw withdrawal thresholds (PWTs). In mechanism study, the activation of microglia, astrocytes, and the mitogen-activated protein kinase (MAPK) pathways in the SDH were evaluated by immunofluorescence staining or Western blot analysis of Iba-1, GFAP, p-ERK, p-p38, and p-JNK. The expression and cellular localization of histone deacetylases (HDACs) 1 and 2 were also detected to investigate molecular mechanism.

Results

Intrathecal injection of T10 inhibited the bone cancer-induced mechanical allodynia with an ED₅₀ of 5.874 μg/kg. This effect was still observed 6 days after drug withdrawal. Bone cancer caused significantly increased expression of HDAC1 in spinal microglia and neurons, with HDAC2 markedly increased in spinal astrocytes, which were accompanied by the upregulation of MAPK pathways and the activation of microglia and astrocytes in the SDH. T10 reversed the increase of HDACs, especially those in glial cells, and inhibited the glial activation.

Conclusions

Our results suggest that the upregulation of HDACs contributes to the pathological activation of spinal glial cells and the chronic pain caused by bone cancer, while T10 help to relieve BCP possibly via inhibiting the upregulation of HDACs in the glial cells in the SDH and then blocking the neuroinflammation induced by glial activation.

Vagus nerve stimulation inhibits trigeminal nociception in a rodent model of episodic migraine

INTRODUCTION

Although neck muscle tension is considered a risk factor for migraine, pungent odors can act as a trigger to initiate an attack in sensitized individuals. Although noninvasive vagus nerve stimulation (nVNS) is now an approved treatment for chronic migraine, how it functions to inhibit trigeminal nociception in an episodic migraine model is not known.

OBJECTIVES

The objectives of this study were to determine if nVNS could inhibit trigeminal nociception in a novel model of episodic migraine and investigate changes in the expression of proteins implicated in peripheral and central sensitization.

METHODS

Sprague-Dawley male rats were injected with an inflammatory agent in the trapezius muscle before exposure to pungent volatile compounds, which was used to initiate trigeminal nociceptor activation. The vagus nerve was stimulated transdermally by a 1-ms pulse of 5 kHz sine waves, repeated at 25 Hz for 2 minutes. Nocifensive head withdrawal response to von Frey filaments was determined and immunoreactive protein levels in the spinal cord and trigeminal ganglion (TG) were investigated.

RESULTS

Exposure to the pungent odor significantly increased the number of nocifensive withdrawals in response to mechanical stimulation of sensitized TG neurons mediated by neck muscle inflammation. Noninvasive vagus nerve stimulation inhibited nociception and repressed elevated levels of P-ERK in TG, Iba1 in microglia, and GFAP in astrocytes from sensitized animals exposed to the pungent odor.

CONCLUSION

Our findings demonstrate that nVNS inhibits mechanical nociception and represses expression of proteins associated with peripheral and central sensitization of trigeminal neurons in a novel rodent model of episodic migraine.

Bile Acids and Cancer: Direct and Environmental-Dependent Effects

Bile acids (BAs) regulate the absorption of fat-soluble vitamins, cholesterol and lipids but have also a key role as singalling molecules and in the modulation of epithelial cell proliferation, gene expression and metabolism. These homeostatic pathways, when disrupted, are able to promote local inflammation, systemic metabolic disorders and, ultimately, cancer. The effect of hydrophobic BAs, in particular, can be linked with cancer in several digestive (mainly oesophagus, stomach, liver, pancreas, biliary tract, colon) and extra-digestive organs (i.e. prostate, breast) through a complex series of mechanisms including direct oxidative stress with DNA damage, apoptosis, epigenetic factors regulating gene expression, reduced/increased expression of nuclear receptors (mainly farnesoid X receptor, FXR) and altered composition of gut microbiota, also acting as a common interface between environmental factors (including diet, lifestyle, exposure to toxics) and the molecular events promoting cancerogenesis. Primary prevention strategies (i.e. changes in dietary habits and lifestyle, reduced exposure to environmental toxics) mainly able to modulate gut microbiota and the epigenome, and the therapeutic use of hydrophilic BAs to counterbalance the negative effects of the more hydrophobic BAs might be, in the near future, part of useful tools for cancer prevention and management.

Cilostazol Suppresses Aβ-induced Neurotoxicity in SH-SY5Y Cells through Inhibition of Oxidative Stress and MAPK Signaling Pathway

Alzheimer's disease (AD) is a slowly progressive form of dementia, characterized by memory impairment and cognitive dysfunction. AD is mainly characterized by the deposition of amyloid β (Aβ) plaques and intracellular neurofibrillary tangles in the brain, along with neuronal degeneration and high levels of oxidative stress. Cilostazol (CSZ) was recently found to suppress the progression of cognitive decline in patients with stable AD receiving acetylcholinesterase inhibitors. This present study aimed to clarify the mechanism by which CSZ protects neurons from degeneration associated with Aβ(1-42). We used Aβ(1-42) to induce neurotoxicity in human neuroblastoma SH-SY5Y cells. Cells were pretreated with CSZ before co-treatment with Aβ. To evaluate the effect of CSZ on oxidative stress, we examined levels of reactive oxygen species (ROS), nicotinamide adenine dinucleotide phosphate oxidase (Nox) activity, mRNA expression of NOX4, and Cu/Zn-Superoxide Dismutase (SOD), as well as apoptosis biomarkers [MTT, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), caspase-3 and -9 activities and staining of annexin V]. We also assayed the activity of mitogen-activated protein kinases (MAPK): p38 MAPK and extracellular signal-regulated kinase1/2 (ERK1/2), and biomarkers of mitochondrial function (Bcl-2 and Bax), and cyclic adenosine monophosphate response element-binding protein (CREB). Aβ-induced oxidative stress (ROS, NOX4 activity, and expression of NOX mRNA), caspase activation (caspase-3 and -9), and p38 MAPK phosphorylation were suppressed by co-treatment with CSZ, but not by ERK1/2 activation. In addition, pretreatment with CSZ suppressed Aβ-induced apoptosis and increased cell viability via suppression of Bax (a proapoptotic protein), upregulation of Bcl-2 (an antiapoptotic protein) and Cu/Zn-SOD (a superoxide scavenging enzyme), and phosphorylation of CREB. These findings suggested that CSZ could counteract neurotoxicity through multiple mechanisms, one mechanism involving the attenuation of oxidative stress by suppressing NOX activity and Nox mRNA expression in Aβ-induced neurotoxicity and another involving the anti-neurotoxic effect via the ERK1/2/phosphorylated CREB pathway.

The Anti-Inflammatory Activity of Toonaciliatin K against Adjuvant Arthritis

Toonaciliatin K is a natural limonoid purified from the Toona ciliata Roem. var. ciliata (Meliaceae). This study is to reveal the inflammatory suppression effect of toonaciliatin K and further the intrinsic mechanism. Firstly, anti-inflammatory effect of toonaciliatin K was evaluated in lipopolysaccharide- (LPS-) induced RAW264.7 cells. RT-PCR results indicated that the mRNA expressions of TNF-α, IL-6, and IL-1β were downregulated by toonaciliatin K. The toonaciliatin K inhibited TNF-α, IL-6, and IL-1β levels stimulated by LPS. Furthermore, LPS elicited the excess iNOS and COX-2 mRNA and protein production and toonaciliatin K attenuated the excess production. Western blot assay demonstrated that MAPK and NF-κB signaling pathways play critical roles in the toonaciliatin K's anti-inflammatory activity. Secondly, toonaciliatin K inhibited carrageenan-induced paw edema in rats. Thirdly, toonaciliatin K alleviated the paw swelling and improved arthritis clinical scores in the adjuvant arthritis rats. Toonaciliatin K decreased the proinflammatory cytokines levels and Mankin scores in adjuvant arthritis rats. The HE staining, safranin O-fast green, and toluidine blue staining results demonstrated that toonaciliatin K alleviated the histological changes of paw, for example, pannus formation, focal loss of cartilage, bone erosion, and presence of extra-articular inflammation. Hence, toonaciliatin K is a promising agent for treatment of arthritis.

LOX-1 is involved in IL-1β production and extracellular matrix breakdown in dental peri-implantitis

PURPOSE

To explore whether lectin-type oxidized LDL receptor 1 (LOX-1), interleukin 1 beta (IL-1β), matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) are involved in the nosogenesis of human dental peri-implantitis and determine the role of LOX-1 in IL-1β, MMP2 and MMP9 production in response to Porphyromonas gingivalis.

METHODS

Peri-implant crevicular fluid (PICF) was collected from ten patients with healthy implants and ten patients with peri-implantitis. The LOX-1 protein in PICF was detected by Western-blot, and the expression of LOX-1 in superficial gingiva of peri-implantitis patients was detected by immunofluorescence staining. The IL-1β, MMP2 and MMP9 proteins in PICF were detected by enzyme-linked immunosorbent assay (ELISA). THP-1 macrophages were pretreated with neutralizing antibody (LOX-1) and inhibitors (LOX-1 and c-Jun N-terminal kinase, JNK) to evaluate the role of LOX-1 and JNK in IL-1β production, as well as the role of LOX-1 in MMP2 and MMP9 production in response to P. gingivalis by quantitative polymerase chain reaction (RT-PCR) and Western-blot.

RESULTS

LOX-1, IL-1β, MMP2 and MMP9 increased in PICF of peri-implantitis patients and in THP-1 macrophages on P. gingivalis stimulation. IL-1β, MMP2 and MMP9 production in response to P. gingivalis in THP-1 macrophages was dependent on LOX-1. JNK was responsible for LOX-1 induced IL-1β production as a result of P. gingivalis infection.

CONCLUSION

LOX-1 is involved in IL-1β production and extracellular matrix breakdown is a novel inflammatory pathway trigger and potential drug target in human dental peri-implantitis.

Formin 2 links neuropsychiatric phenotypes at young age to an increased risk for dementia

Age-associated memory decline is due to variable combinations of genetic and environmental risk factors. How these risk factors interact to drive disease onset is currently unknown. Here we begin to elucidate the mechanisms by which post-traumatic stress disorder (PTSD) at a young age contributes to an increased risk to develop dementia at old age. We show that the actin nucleator Formin 2 (Fmn2) is deregulated in PTSD and in Alzheimer's disease (AD) patients. Young mice lacking the Fmn2 gene exhibit PTSD-like phenotypes and corresponding impairments of synaptic plasticity, while the consolidation of new memories is unaffected. However, Fmn2 mutant mice develop accelerated age-associated memory decline that is further increased in the presence of additional risk factors and is mechanistically linked to a loss of transcriptional homeostasis. In conclusion, our data present a new approach to explore the connection between AD risk factors across life span and provide mechanistic insight to the processes by which neuropsychiatric diseases at a young age affect the risk for developing dementia.

Galectin-3 induced by hypoxia promotes cell migration in thyroid cancer cells

Background

The aim of this study is to investigate the role of Galectin-3 in human thyroid cancer migration.

Methods

The expression of Galectin-3 in surgical specimens was investigated using immunohistochemistry and western blot. A papillary thyroid cancer cell line (B-cpap) and an anaplastic thyroid cancer cell line (8305c) were transfected with short-hairpin RNA against Galectin-3 (Gal-3-shRNA). Low-molecular citrus pectin (LCP) was also used to antagonize Galectin-3. The migration and invasion of the cell lines were examined. The related signaling pathways were investigated to explore the Galectin-3 mechanism of action.

Results

Galectin-3 was highly expressed in metastasized thyroid cancers. Knocking down and antagonizing Galectin-3 significantly suppressed the migration of thyroid cancer cells. Knocking down Galectin-3 inhibited the activity of Wnt, MAPK, Src and Rho signaling pathways. Galectin-3 was up-regulated via HIF-1α in a hypoxic environment. Galectin-3 knockdown could reduce cell motility in hypoxic environments.

Conclusion

This study suggests that Galectin-3 could act as a modulator of thyroid cancer migration, especially in hypoxic microenvironments. This regulation function of Galectin-3 may work through multiple signaling pathways.

KATP channel block inhibits the Toll-like receptor 2-mediated stimulation of NF-κB by suppressing the activation of Akt, mTOR, JNK and p38-MAPK

Changes in the K_ATP channel activity have been shown to regulate inflammation and immune responses. Using human keratinocytes, we investigated the effect of K_ATP channel inhibition on inflammatory mediator production in relation to the Toll like receptor-2-mediated-Akt, mTOR and NF-κB pathways, as well as JNK and p38-MAPK, which regulate the transcription genes involved in immune and inflammatory responses. 5-Hydroxydecanoate (a selective K_ATP channel blocker), glibenclamide (a cell surface and mitochondrial K_ATP channel inhibitor), the Akt inhibitor, rapamycin, Bay 11-7085 and N-acetylcysteine reduced the lipoteichoic acid- or peptidoglycan-induced production of cytokines and chemokines, and production of reactive oxygen species and increased the levels and activities of Kir 6.2, NF-κB, phosphorylated-Akt and mTOR, and the activation of JNK and p38-MAPK in keratinocytes. Inhibitors of c-JNK (SP600125) and p38-MAPK (SB203580) attenuated the lipoteichoic acid- or peptidoglycan-induced production of inflammatory mediators, the activation of the JNK and p38-MAPK, and the production of reactive oxygen species in keratinocytes. The results show that K_ATP channel blockers may reduce the bacterial component-stimulated production of inflammatory mediators in keratinocytes by suppressing the Toll-like receptor-2-mediated activation of the Akt, mTOR and NF-κB pathways, as well as JNK and p38-MAPK. The suppressive effect of K_ATP channel blockers appears to be achieved by the inhibition of reactive oxygen species production.

Dectin-1 is essential for IL-1β production through JNK activation and apoptosis in Aspergillus fumigatus keratitis

PURPOSE

To investigate the role of phosphorylated JNK in Dectin-1-induced IL-1β production and the role of Dectin-1 in apoptosis in mouse Aspergillus fumigatus (A. fumigatus) keratitis.

METHODS

Mice corneas were pretreated with Dectin-1 siRNA or SP600125 (the inhibitor of JNK) before A. fumigatus infection. THP-1 macrophages were preincubated with SP600125 before the stimulation of A. fumigatus conidia. Dectin-1, IL-1β, JNK, Bax, Bcl-2, cytochrome-c (cyt-c), caspase-9, caspase-8 and caspase-3 expressions were tested by PCR, Western blot, or Immunofluorescence staining.

RESULTS

Pretreatment with Dectin-1 siRNA significantly decreased A. fumigatus-induced IL-1β production and JNK phosphorylation compared with scrambled control in C57BL/6 mice corneas. SP600125 treatment before infection significantly inhibited IL-1β production compared with DMSO control both in mice corneas and THP-1 macrophages. Furthermore, Dectin-1 deficiency resulted in increased ratio of Bax/Bcl-2, release of cyt-c, activation of caspase-9 and caspase-3 in mouse A. fumigatus keratitis. However, Dectin-1 deficiency didn't affect the activation of caspase-8.

CONCLUSIONS

Being an important inflammatory PRR to mediate host inflammatory response, Dectin-1 induced IL-1β production is JNK dependent in mouse A. fumigatus keratitis, and suppressed apoptosis mediated anti-inflammatory response.

Oxidative stress regulates mitogen‑activated protein kinases and c‑Jun activation involved in heat stress and lipopolysaccharide‑induced intestinal epithelial cell apoptosis

Heat stress and gut‑derived endotoxinemia are common causes of multiple organ dysfunction syndrome in heat stroke patients. Evidence has demonstrated that cell apoptosis in the small intestine serves an important role in the pathogenesis of heatstroke, which leads to increased intestinal permeability to endotoxin or lipopolysaccharides (LPS) from the gut entering the circulation. However, little is known about the potential underlying mechanisms mediating heat stress combined with LPS‑induced intestinal epithelial cell apoptosis. In the present study, LPS combined with heat stress induced production of reactive oxygen species (ROS), mitochondrial membrane potential disruption and cell apoptosis, which eventually led to increased intestinal permeability and reduced epithelial resistance in the IEC‑6 cell line. Inductions in ROS, mitochondrial membrane potential disruption and cell apoptosis were detected by using an ROS assay kit, 5,5',6,6'‑tetrachloro‑1,1',3,3'tetraethylbenzimidazo carbocyanine iodide dye kit and annexin V‑fluorescein isothiocyanate apoptosis kit, respectively. The effect of ROS on mitogen activated protein kinases (MAPKs) and c‑Jun activation was investigated using the antioxidant drug, butylated hydroxyanisole (BHA) by western blotting. The results of the present study demonstrated that ROS is essential to activate p38, extracellular signal‑regulated kinase (ERK) and c‑Jun, but not c‑Jun N‑terminal kinase (JNK), in LPS combined with heat stress treated cells. Furthermore, ROS, and activation of p38, JNK and c‑Jun, were revealed to serve pro‑apoptosis roles which aggravated damage to epithelial barrier integrity, as assessed by flow cytometry using Annexin V‑fluorescein isothiocyanate staining and pretreatment of cells with specific inhibitors of ROS, JNK, p38 and c‑Jun (BHA, SP600125, SB203580 and c‑Jun peptide, respectively). Transepithelial electrical resistance and horseradish peroxidase permeability were detected in cells treated with LPS combined with heat stress, which revealed that ERK serves an anti‑apoptosis role, as determined by pretreatment of cells with PD98059, a specific inhibitor of ERK. In conclusion, these findings suggested a novel role of the ROS signaling pathway which involved activation of MAPKs and c‑Jun, following LPS combined with heat stress‑induced IEC‑6 cell apoptosis and impairment of the epithelial barrier. These results may facilitate understanding of pathological conditions involving ROS, such as heat stroke.

Autophagy-related genes are induced by histone deacetylase inhibitor suberoylanilide hydroxamic acid via the activation of cathepsin B in human breast cancer cells

Autophagy is involved in modulating tumor cell motility and invasion, resistance to epithelial-to-mesenchymal transition, anoikis, and escape from immune surveillance. We have previous shown that SAHA is capable to induce several apoptosis and autophagy-related gene expression in breast cancers. However, the exact mechanisms of autophagy activation in this context have not been fully identified. Our results showed that the expression and the activity of Cathepsin B (CTSB), one of the major lysosomal cysteine proteases, were significantly increased in MDA-MB- 231 and MCF-7 cells upon SAHA treatment. We confirmed that Cystatin C, a protease inhibitor, significantly inhibited the expression of CTSB induced by SAHA on breast cancer cells. We demonstrated that SAHA is able to promote the expression of LC3II, a key member in the maturation of the autophagosome, the central organelle of autophagy in breast cancer cells. However, SAHA induced LC3II expression is effectively suppressed after the addition of Cystatin C to the cell culture. In addition, we identified a number of genes, as well as the mitogen-activated protein kinase (MAPK) signaling that is potentially involved in the action of SAHA and CTSB in the breast cancer cells. Overall, our results revealed that the autophagy-related genes are induced by SAHA via the activation of CTSB in breast cancer cells. An improved understanding of SAHA molecular mechanisms in breast cancer may facilitate SAHA clinical use and the selection of suitable combinations.

Sphingosine-1-phosphate suppresses chondrosarcoma metastasis by upregulation of tissue inhibitor of metalloproteinase 3 through suppressing miR-101 expression

Chondrosarcoma is the second most common primary malignancy form of bone cancer, exhibiting resistance to chemotherapy and radiation therapy as well as developing high metastasis ability in late‐stage tumors. Thus, understanding the metastatic processes of chondrosarcoma is considered a strategy for the treatment of this disease. Sphingosine 1‐phosphate (S1P), a bioactive sphingolipid, is produced intracellularly by sphingosine kinase (SphK) and is regarded as a second signaling molecule that regulates inflammation, proliferation, angiogenesis, and metastasis. However, the effect of S1P on chondrosarcoma remains uncertain. As demonstrated by the transwell, immunoblotting, and real‐time PCR analyses, we found that S1P inhibited cell migration and MMP‐2 expression through the upregulation of the tissue inhibitor of metalloproteinase‐3 (TIMP‐3) expression in human chondrosarcoma cells. Additionally, we also showed that microRNA (miRNA)‐101, which targets the 3′ untranslated region (3′UTR) of TIMP‐3, decreased significantly following S1P treatment. After transfection with miR‐101 mimics, the S1P‐regulated cell migration and TIMP‐3 expression were both reversed. Furthermore, we also showed that the S1P‐inhibited cell migration is mediated through the c‐Src/MEK/ERK signaling axis. Meanwhile, the in vivo study indicated that overexpression of SphK1 decreases chondrosarcoma metastasis to the lungs. Our results illustrate the clinical significance between SphK1, TIMP‐3, and miR‐101 in human chondrosarcoma patients. Taken together, our results suggest that S1P and miR‐101 may prove to be potential therapeutic targets for future chondrosarcoma treatment.

Peptide GC31 inhibits chemokines and ICAM-1 expression in corneal fibroblasts exposed to LPS or poly(I:C) by blocking the NF-κB and MAPK pathways

In keratitis, keratocytes play a vital role by releasing inflammatory cytokines and expressing intercellular cell adhesion molecule-1(ICAM-1). GC31 is a peptide derived from thrombomodulin, an endogenous protein with potential anti-inflammation properties. We evaluated the protective effect of GC31 in LPS- or poly(I:C)-induced corneal fibroblasts. Cultured keratocytes were treated with either LPS or poly(I:C); The mRNA and protein expressions of IL-6, IL-8, MCP-1, and IFN-γ were determined by real-time RT-PCR and ELISA. The expression level of ICAM-1 was estimated by real-time RT-PCR, immunofluorescence, and western blot. The underlying pathways were investigated by detecting NF-κB p65 translocation and phosphorylation of IκBα, p65, p38, JNK, and ERK. The MTS assay was used to measure cell viability of keratocytes after GC31 incubation. The elevation of IL-6, IL-8, MCP-1, and IFN-γ expression induced by LPS or poly(I:C) was significantly inhibited by GC31 in a dose-dependent manner at both mRNA and protein levels. GC31 also reduced the expression of ICAM-1 in keratocytes after LPS or poly(I:C) stimulation. LPS or poly(I:C) induced p65 translocation and phosphorylation of IκBα, p65, p38, and JNK were suppressed by GC31.GC31 is not only an effective inhibitor of LPS-induced inflammatory response, but it also inhibits poly(I:C)-induced release of inflammatory cytokines and ICAM-1 expression by blocking the NF-κB and MAPK (p38 and JNK) pathways. This suggested that GC31 may exert a protective effect in attenuating corneal inflammation by suppressing the immune response of the fibroblasts.

Plumbagin suppresses chronic periodontitis in rats via down-regulation of TNF-α, IL-1β and IL-6 expression

Chronic periodontitis (CP) is one of the most common oral diseases, which causes alveolar bone absorption and tooth loss in adults. In this study we aimed to investigate the potential of plumbagin (PL), a widely-investigated active compound extracted from the traditional Chinese herb Plumbago zeylanica L in treating CP. Human periodontal ligament stem cells (PDLSCs) were used for in vitro studies, whereas an animal model of CP was established in SD rats by ligation+Porphyromonas gingivalis (Pg) stimulation. The rats were injected with PL (2, 4, and 6 mg·kg^-1·d^-1, ip) for 4 weeks. Treatment of PDLSCs with TNF-α (10 ng/mL) markedly stimulated the expression of the proinflammatory cytokines TNF-α, IL-1β and IL-6, as well as the chemokines CCL-2 and CCL-5, which were dose-dependently suppressed by co-treatment with PL (1.25-5 μmol/L). Furthermore, PL (3.75 μmol/L) markedly suppressed TNF-α-induced activation of the MAPK, NF-κB and JAK/STAT signaling pathways in PDLSCs. In consistence with the in vitro studies, PL administration significantly decreased the expression of TNF-α, IL-1β and IL-6 in gingiva of the rat with CP, with the dosage 4 mg·kg^-1·d^-1 showing the best anti-inflammatory effect. Moreover, PL administration decelerated bone destruction in the rat with CP, evidenced by the aveolar bone loss (ABL) and H&E staining results. In conclusion, PL suppresses CP progression in rats by downregulating the expressions of TNF-α, IL-1β and IL-6 and inhibiting the MAPK, NF-κB and JAK/STAT signaling pathways.

TNFα affects CREB-mediated neuroprotective signaling pathways of synaptic plasticity in neurons as revealed by proteomics and phospho-proteomics

Neuroinflammation is a hallmark of Alzheimer's disease and TNFα as the main inducer of neuroinflammation has neurodegenerative but also pro-regenerative properties, however, the dose-dependent molecular changes on signaling pathway level are not fully understood. We performed quantitative proteomics and phospho-proteomics to target this point.

In HT22 cells, we found that TNFα reduced mitochondrial signaling and inhibited mTOR protein translation signaling but also led to induction of neuroprotective MAPK-CREB signaling. Stimulation of human neurons with TNFα revealed similar cellular mechanisms. Moreover, a number of synaptic plasticity-associated genes were altered in their expression profile including CREB.

SiRNA-mediated knockdown of CREB in human neurons prior to TNFα stimulation led to a reduced number of protein/phospho-protein hits compared to siRNA-mediated knockdown of CREB or TNFα stimulation alone and countermeasured the reduced CREB signaling. In vivo data of TNFα knockout mice showed that learning ability did not depend on TNFα per se but that TNFα was essential for preserving the learning ability after episodes of lipopolysaccharide-induced neuroinflammation. This may be based on modulation of CREB/CREB signaling as revealed by the in vitro / in vivo data.

Our data show that several molecular targets and signaling pathways induced by TNFα in neurons resemble those seen in Alzheimer's disease pathology.

Technological advances for interrogating the human kinome

There is increasing appreciation among researchers and clinicians of the value of investigating biology and pathobiology at the level of cellular kinase (kinome) activity. Kinome analysis provides valuable opportunity to gain insights into complex biology (including disease pathology), identify biomarkers of critical phenotypes (including disease prognosis and evaluation of therapeutic efficacy), and identify targets for therapeutic intervention through kinase inhibitors. The growing interest in kinome analysis has fueled efforts to develop and optimize technologies that enable characterization of phosphorylation-mediated signaling events in a cost-effective, high-throughput manner. In this review, we highlight recent advances to the central technologies currently available for kinome profiling and offer our perspectives on the key challenges remaining to be addressed.

Candidate SNP Markers of Familial and Sporadic Alzheimer's Diseases Are Predicted by a Significant Change in the Affinity of TATA-Binding Protein for Human Gene Promoters

While year after year, conditions, quality, and duration of human lives have been improving due to the progress in science, technology, education, and medicine, only eight diseases have been increasing in prevalence and shortening human lives because of premature deaths according to the retrospective official review on the state of US health, 1990-2010. These diseases are kidney cancer, chronic kidney diseases, liver cancer, diabetes, drug addiction, poisoning cases, consequences of falls, and Alzheimer's disease (AD) as one of the leading pathologies. There are familial AD of hereditary nature (~4% of cases) and sporadic AD of unclear etiology (remaining ~96% of cases; i.e., non-familial AD). Therefore, sporadic AD is no longer a purely medical problem, but rather a social challenge when someone asks oneself: “What can I do in my own adulthood to reduce the risk of sporadic AD at my old age to save the years of my lifespan from the destruction caused by it?” Here, we combine two computational approaches for regulatory SNPs: Web service SNP_TATA_Comparator for sequence analysis and a PubMed-based keyword search for articles on the biochemical markers of diseases. Our purpose was to try to find answers to the question: “What can be done in adulthood to reduce the risk of sporadic AD in old age to prevent the lifespan reduction caused by it?” As a result, we found 89 candidate SNP markers of familial and sporadic AD (e.g., rs562962093 is associated with sporadic AD in the elderly as a complication of stroke in adulthood, where natural marine diets can reduce risks of both diseases in case of the minor allele of this SNP). In addition, rs768454929, and rs761695685 correlate with sporadic AD as a comorbidity of short stature, where maximizing stature in childhood and adolescence as an integral indicator of health can minimize (or even eliminate) the risk of sporadic AD in the elderly. After validation by clinical protocols, these candidate SNP markers may become interesting to the general population [may help to choose a lifestyle (in childhood, adolescence, and adulthood) that can reduce the risks of sporadic AD, its comorbidities, and complications in the elderly].

Food-Derived Antioxidant Polysaccharides and Their Pharmacological Potential in Neurodegenerative Diseases

Oxidative stress is known to impair architecture and function of cells, which may lead to various chronic diseases, and therefore therapeutic and nutritional interventions to reduce oxidative damages represent a viable strategy in the amelioration of oxidative stress-related disorders, including neurodegenerative diseases. Over the past decade, a variety of natural polysaccharides from functional and medicinal foods have attracted great interest due to their antioxidant functions such as scavenging free radicals and reducing oxidative damages. Interestingly, these antioxidant polysaccharides are also found to attenuate neuronal damages and alleviate cognitive and motor decline in a range of neurodegenerative models. It has recently been established that the neuroprotective mechanisms of polysaccharides are related to oxidative stress-related pathways, including mitochondrial function, antioxidant defense system and pathogenic protein aggregation. Here, we first summarize the current status of antioxidant function of food-derived polysaccharides and then attempt to appraise their anti-neurodegeneration activities.

Genistein Protects Genioglossus Myoblast Against Hypoxia-induced Injury through PI3K-Akt and ERK MAPK Pathways

Obstructive sleep apnea and hypopnea syndrome (OSAHS) is a clinical syndrome characterized by recurrent episodes of obstruction of the upper airway during sleep that leads to a hypoxic condition. Genioglossus, an important pharyngeal muscle, plays an important role in maintaining an open upper airway for effective breathing. Our previous study found that genistein (a kind of phytoestrogen) protects genioglossus muscle from hypoxia-induced oxidative injury. However, the underlying mechanism is still unknown. In the present study, we examined the effects of hypoxia on genioglossus myoblast proliferation, viability and apoptosis, and the protective effect of genistein and its relationship with the PI3K/Akt and ERK MAPK pathways. Cell viability and Bcl-2 were reduced under hypoxic condition, while ROS generation, caspase-3, MDA, and DNA damage were increased following a hypoxia exposure. However, the effects of hypoxia were partially reversed by genistein in an Akt- and ERK- (but not estrogen receptor) dependent manner. In conclusion, genistein protects genioglossus myoblasts against hypoxia-induced oxidative injury and apoptosis independent of estrogen receptor. The PI3K-Akt and ERK1/2 MAPK signaling pathways are involved in the antioxidant and anti-apoptosis effect of genistein on genioglossus myoblasts.

Protective effect of crocin on BPA-induced liver toxicity in rats through inhibition of oxidative stress and downregulation of MAPK and MAPKAP signaling pathway and miRNA-122 expression

Bisphenol A (BPA) is an artificial environmental endocrine disrupting chemical and commonly used as a monomer of polycarbonate plastics and epoxy resins. The aim of the present study is to investigate the hepatoprotective effects of crocin, a constituent of saffron, against BPA-induced liver toxicity. We showed that treatment of male Wistar rats with 0.5 mg/kg BPA for 30 days increased the level of 8-isoprostane, decreased the level of reduced glutathione, elevated serum levels of aspartate aminotransferase, lactate dehydrogenase, triglyceride, and glucose, and induced periportal inflammation. Western blot results revealed that BPA increased the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK1/2), and mitogen-activated protein kinase-activated protein kinase (MAPKAPK), but not p38. BPA also reduced the Akt signaling activation and upregulated microRNA (miR-122) expression. Moreover, we showed here that crocin 20 mg/kg administration ameliorated liver damage and improved elevated levels of TG and liver enzymes of BPA-treated rats possibly though antioxidant activity, downregulation of miR-122 transcript level and lowering the phosphorylation of JNK, ERK1/2, and MAPKAPK and subsequently their activities. Overall, the findings suggest that crocin possesses hepatoprotective effects against BPA-induced liver toxicity by enhancing the antioxidative defense system and regulation of important signaling pathway activities and miR-122 expression.

Matrine inhibits the metastatic properties of human cervical cancer cells via downregulating the p38 signaling pathway

Matrine is a traditional Chinese herbal medicine that shows antitumor efficacy for many types of cancer. The present study evaluated the antitumor efficacy of matrine on cervical cancer and to investigate the underlying mechanisms. We performed MTT assays, and in vitro invasion and migration assays, and P1 L6 found that matrine significantly inhibited cervical cancer cell growth by inducing apoptosis, and suppressed the invasion and migration ability of cervical cancer cells in vitro in a concentration-dependent manner. Mechanistically, we found that matrine decreased the expression and activity of the extracellular matrix factors, matrix metalloproteinases-2 (MMP-2) and MMP-9 via the suppression of p38 signaling pathway. In addition, when cervical cancer cells were grown as xenografts in nude mice, intraperitoneal (i.p.) injection of matrine induced a significant dose-dependent decrease in tumor growth. Taken together, these findings suggest that a potential mechanism by which matrine inhibits the growth and metastasis of cervical cancer through downregulating the p38 signaling pathway.

Protective effects of paeoniflorin on TNBS-induced ulcerative colitis through inhibiting NF-kappaB pathway and apoptosis in mice

Paeoniflorin is traditionally used to treat inflammatory disorders. In our laboratory, we have scientifically validated the anti-inflammatory effect of paeoniflorin. In this study, it has been aimed to evaluate in vivo anti-inflammatory effect of paeoniflorin isolated from the dried peeled root of Paeonia lactiflora Pall. It was further intended to find out the probable mechanism of anti-inflammatory effect of paeoniflorin. The anti-inflammatory effect of paeoniflorin (15, 30 and 45mg/kg) was measured employing TNBS-induced ulcerative colitis model of acute inflammation. The TNBS injection resulted significant colitis formation when compared with un-injected mice. The anti-inflammatory effects of paeoniflorin for ulcerative colitis were assessed by body weight, colonic weight and length, macroscopic scores, and histopathological examinations. In addition, the colonic tissue levels of inflammation markers, including myeloperoxidase (MPO), IL-2, IL-6, IL-10, IL-12, IL-1β, TNF-α and IFN-γ were also determined to assess the effect of paeoniflorin. In addition, western blot demonstrated that paeoniflorin inhibited NF-kappaB signaling pathway and apoptosis in TNBS-induced ulcerative colitis tissues. In conclusion, all the findings of this study suggested that paeoniflorin has the anti-inflammatory effect in ulcerative colitis via inhibiting MAPK/NF-kappaB pathway and apoptosis in mice.

Baicalein exerts anti-neuroinflammatory effects to protect against rotenone-induced brain injury in rats

Baicalein, a major bioactive flavone constituent isolated from Scutellaria baicalensis Georgi, has been shown to be neuroprotective in several Parkinson's disease (PD) animal models. Since neuroinflammation has been known to play a critical role in the pathogenesis of PD, potential explanation for the neuroprotective action of anti-PD compounds involves among others reduced inflammation. Our study investigated that one of the mechanisms of protection afforded by baicalein in rotenone-induced parkinsonian rats was associated with anti-inflammatory action and explored its underlying mechanism in vivo and in vitro. The results showed that baicalein treatment improved motor impairments, attenuated brain damage, suppressed the production of proinflammatory cytokines (tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6)), modulated the astrocytes and microglia activation, and blocked the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signals in rotenone-induced rats of PD. Furthermore, treatment of baicalein prominently suppressed the generation of nitric oxide (NO) and the expression of inducible NO synthase (iNOS) protein by blocking LPS-induced IκBα phosphorylation and NF-κB translocation, and downregulated the Toll-like receptor 4 (TLR4) which functions in the upstream of NF-κB signal in the activated BV₂ microglia. In conclusion, our studies suggest that baicalein may be effective in the treatment of PD through anti-neuroinflammation.

Gene networks in neurodegenerative disorders

Three neurodegenerative diseases [Amyotrophic Lateral Sclerosis (ALS), Parkinson's disease (PD) and Alzheimer's disease (AD)] have many characteristics like pathological mechanisms and genes. In this sense some researchers postulate that these diseases share the same alterations and that one alteration in a specific protein triggers one of these diseases. Analyses of gene expression may shed more light on how to discover pathways, pathologic mechanisms associated with the disease, biomarkers and potential therapeutic targets. In this review, we analyze four microarrays related to three neurodegenerative diseases. We will systematically examine seven genes (CHN1, MDH1, PCP4, RTN1, SLC14A1, SNAP25 and VSNL1) that are altered in the three neurodegenerative diseases. A network was built and used to identify pathways, miRNA and drugs associated with ALS, AD and PD using Cytoscape software an interaction network based on the protein interactions of these genes. The most important affected pathway is PI3K-Akt signalling. Thirteen microRNAs (miRNA-19B1, miRNA-107, miRNA-124-1, miRNA-124-2, miRNA-9-2, miRNA-29A, miRNA-9-3, miRNA-328, miRNA-19B2, miRNA-29B2, miRNA-124-3, miRNA-15A and miRNA-9-1) and four drugs (Estradiol, Acetaminophen, Resveratrol and Progesterone) for new possible treatments were identified.

Aspergillus fumigatus-induced early inflammatory response in pulmonary microvascular endothelial cells: Role of p38 MAPK and inhibition by silibinin

Human invasive pulmonary aspergillosis (IPA) is a serious infectious disease mainly caused by Aspergillus fumigatus (A. fumigatus). Pulmonary microvascular endothelial cells (PMVECs) are important ones in the human lung tissue. However, it remains unclear about the role of PMVECs in IPA. In the present study, we cocultured PMVECs with A. fumigatus. We observed that A. fumigatus induced dose- and time-dependent increases of interleukin 6 (IL-6), interleukin 1β (IL-1β) and intercellular adhesion molecule 1 (ICAM-1) concentration in the cultures. Significant increases in IL-6, IL-1β, E-selectin, and ICAM-1 mRNA expression were also observed in the cultures treated with A. fumigatus. While preincubation with SB203580 (10μM) did not cause significant changes in IL-6, IL-1β and ICAM-1 concentration in the cocultures, significant IL-6, IL-1β and ICAM-1 concentration decreases were observed in the cocultures preincubated with SB203580 (20μM). Neither SP600125 (10-20μM) nor PD98059 (10-20μM) caused significant changes in IL-6, IL-1β and ICAM-1 concentration in the cocultures. PCR results also showed that SB203580 (20μM) (neither SP600125 (20μM) nor PD98059 (20μM)) preincubation significantly decreased IL-6, IL-1β, E-selectin and ICAM-1 mRNA expression in the cocultures. In addition, significant p38 MAPK phosphorylation increase was observed in the PMVECs cultures treated with A. fumigatus. Furthermore, silibinin pre-treatment and post-treatment were observed to significantly down-regulate mRNA and protein expression of proinflammatory factors and adhesion molecules in the cocultures. Finally, we observed that silibinin significantly inhibited A. fumigatus-induced p38 MAPK activation in PMVECs. Our results indicated that PMVECs might participate in IPA early inflammation which is mediated by p38 MAPK. Silibinin may inhibit A. fumigatus-induced inflammation in PMVECs through p38 MAPK.

Dab1 Contributes to Angiotensin II-Induced Apoptosis via p38 Signaling Pathway in Podocytes

Numerous studies have found that angiotensin II (Ang II) participates in podocyte apoptosis and exacerbates progression of end-stage kidney disease (ESKD). However, its underlying mechanism remains largely unexplored. As a homolog of Drosophila disabled (Dab) protein, Dab1 plays a vital role in cytoskeleton, neuronal migration, and proliferation. In the present study, our data revealed that Ang II-infused rats developed hypertension, proteinuria, and podocyte injury accompanied by Dab1 phosphorylation and increased reelin expression in kidney. Moreover, Ang II induced podocyte apoptosis in vitro. Dab1 phosphorylation and reelin expression in podocytes were increased after exposure to Ang II. Conversely, Dab1 small interfering RNA (siRNA) exerted protective effects on Ang II-induced podocyte apoptosis, resulting in decreased p38 phosphorylation and reelin expression. These results indicated that Dab1 mediated Ang II-induced podocyte apoptosis via p38 signaling pathway.

Resveratrol inhibits urban particulate matter-induced COX-2/PGE2 release in human fibroblast-like synoviocytes via the inhibition of activation of NADPH oxidase/ROS/NF-κB

Human fibroblast-like synoviocytes (FLSs) play a role in joint synovial inflammation in rheumatoid arthritis (RA). Some evidence indicates that particulate matter (PM) in air pollution could contribute to the progression of RA. However, more research is needed to clarify this relationship. Up-regulation of cyclooxygenase (COX)-2 and its metabolite prostaglandin E₂ (PGE₂) are implicated in various inflammatory diseases. Resveratrol, a polyphenol found mainly in grapes and red wine, has antioxidant and anti-inflammatory activities. In the present study, we demonstrated that resveratrol reduced PM-induced COX-2/PGE₂ expression in human FLSs, and attenuated PM-enhanced NADPH oxidase activity and ROS generation. In addition, PM induced Akt, ERK1/2, or p38 MAPK activation, which was inhibited by resveratrol. Finally, we demonstrated that PM enhanced NF-κB p65 phosphorylation and the NF-κB promoter activity, which were reduced by pretreatment with a ROS inhibitor or resveratrol. Thus, we concluded that resveratrol functions as a suppressor of PM-induced inflammatory signaling pathways by inhibiting COX-2/PGE₂ expression.

The Role of Unfolded Protein Response and Mitogen-Activated Protein Kinase Signaling in Neurodegenerative Diseases with Special Focus on Prion Diseases

Prion diseases are neurodegenerative pathologies characterized by the accumulation of a protease-resistant form of the cellular prion protein named prion protein scrapie (PrP^Sc) in the brain. PrP^Sc accumulation in the endoplasmic reticulum (ER) result in a dysregulated calcium (Ca²⁺) homeostasis and subsequent initiation of unfolded protein response (UPR) leading to neuronal dysfunction and apoptosis. The molecular mechanisms for the transition between adaptation to ER stress and ER stress-induced apoptosis are still unclear. Mitogen-activated protein kinases (MAPKs) are serine/threonine protein kinases that rule the signaling of many extracellular stimuli from plasma membrane to the nucleus. However the identification of numerous points of cross talk between the UPR and MAPK signaling pathways may contribute to our understanding of the consequences of ER stress in prion diseases. Indeed the MAPK signaling network is known to regulate cell cycle progression and cell survival or death responses following a variety of stresses including misfolded protein response stress. In this article, we review the UPR signaling in prion diseases and discuss the triad of MAPK signaling pathways. We also describe the role played by MAPK signaling cascades in Alzheimer’s (AD) and Parkinson’s disease (PD). We will also overview the mechanisms of cell death and the role of MAPK signaling in prion disease progression and highlight potential avenues for therapeutic intervention.

Rotundarpene inhibits TNF-α-induced activation of the Akt, mTOR, and NF-κB pathways, and the JNK and p38 associated with production of reactive oxygen species

Ilex Rotunda Thunb has been shown to have anti-inflammatory and antioxidant effects. In human keratinocytes, we investigated the effect of rotundarpene (4-caffeoyl-3-methyl-but-2-ene-1,4-diol) on the TNF-α-stimulated production of inflammatory mediators in relation to the Akt, mTOR, and NF-κB pathways, and the JNK and p38-MAPK. Rotundarpene, Akt inhibitor, Bay 11-7085, rapamycin, and N-acetylcysteine inhibited the TNF-α-stimulated production of cytokines and chemokines, increase in the levels of p-Akt and mTOR, activation of NF-κB, and production of reactive oxygen species in keratinocytes. TNF-α treatment induced phosphorylation of the JNK and p38-MAPK. Inhibitors of the c-JNK (SP600125) and p38-MAPK (SB203580) reduced the TNF-α-induced production of inflammatory mediators, binding of NF-κB to DNA, and activation of the JNK and p38-MAPK in keratinocytes. The results show that rotundarpene may reduce the TNF-α-stimulated inflammatory mediator production by suppressing the reactive oxygen species-dependent activation of the Akt, mTOR, and NF-κB pathways, and activation of the JNK and p38-MAPK in human keratinocytes. Additionally, rotundarpene appears to attenuate the Akt, mTOR, and NF-κB pathways and the JNK and p38-MAPK-mediated inflammatory skin diseases.

Reduction-oxidation pathways involved in cancer development: a systematic review of literature reviews

Oxidative stress results from an imbalance of the reactive oxygen species/reactive nitrogen species (ROS/RNS) production and the oxidants defense system. Extensive research during the last decades has revealed that oxidative stress can mediate cancer initiation and development by leading not only to molecular damage but also to a disruption of reduction-oxidation (redox) signaling. In order to provide a global overview of the redox signaling pathways, which play a role in cancer formation, we conducted a systematic literature search in PubMed and ISI Web of Science and identified 185 relevant reviews published in the last 10 years. The 20 most frequently described pathways were selected to be presented in this systematic review and could be categorized into 3 groups: Intracellular ROS/RNS generating organelles and enzymes, signal transduction cascades kinases/phosphatases and transcription factors. Intracellular ROS/RNS generation organelles are mitochondria, endoplasmic reticulum and peroxisomes. Enzymes, including NOX, COX, LOX and NOS, are the most prominent enzymes generating ROS/RNS. ROS/RNS act as redox messengers of transmembrane receptors and trigger the activation or inhibition of signal transduction kinases/phosphatases, such as the family members of protein tyrosine kinases and protein tyrosine phosphatases. Furthermore, these reactions activate downstream signaling pathways including protein kinase of the MAPK cascade, PI3K and PKC. The kinases and phosphatases regulate the phosphorylation status of transcription factors including APE1/Ref-1, HIF-1α, AP-1, Nrf2, NF-κB, p53, FOXO, STAT, and β-catenin. Finally, we briefly discuss cancer prevention and treatment opportunities, which address redox pathways and further research needs.

Liraglutide Improves Water Maze Learning and Memory Performance While Reduces Hyperphosphorylation of Tau and Neurofilaments in APP/PS1/Tau Triple Transgenic Mice

The purpose of this study was to explore how liraglutide affects AD-like pathology and cognitive function in APP/PS1/Tau triple transgenic (3 × Tg) Alzheimer disease (AD) model mice. Male 3 × Tg mice and C57BL/6 J mice were treated for 8 weeks with liraglutide (300 μg/kg/day, subcutaneous injection) or saline. Levels of phosphorylated tau, neurofilaments (NFs), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) in brain tissues were assessed with western blots. Fluoro-Jade-B labeling were applied to detect pathological changes. The Morris water maze (MWM) was used to assess the spatial learning and memory. Liraglutide decreased levels of hyperphosphorylated tau and NFs in 3 × Tg liraglutide-treated (Tg + LIR) mice, increased ERK phosphorylation, and decreased JNK phosphorylation. Liraglutide also decreased the number of degenerative neurons in the hippocampus and cortex of Tg + LIR mice, and shortened their escape latencies and increased their hidden platform crossings in the MWM task. Liraglutide did not significantly affect the animals' body weight (BW) or fasting blood glucose. Liraglutide can reduce hyperphosphorylation of tau and NFs and reduce neuronal degeneration, apparently through alterations in JNK and ERK signaling, which may be related to its positive effects on AD-like learning and memory impairment.

Heliangin inhibited lipopolysaccharide-induced inflammation through signaling NF-κB pathway on LPS-induced RAW 264.7 cells

The heliangin is a natural agent mainly isolated from Helianthus tuberosus L. (Asteraceae). In order to investigate the anti-inflammatory effect of heliangin, several typical models in vivo and in vitro were performed. The RAW264.7 mouse macrophages cells were employed in vitro and dexamethasone were conducted as positive. The cytotoxicity results of heliangin on RAW 264.7 cells provided the safety in vitro for further study. The mRNA of TNF-α, IL-6, iNOS and COX-2 were degraded under heliangin exposure in LPS-stimulated RAW 264.7 cells. The protein expression of iNOS, COX-2 were decreased via heliangin exposure in a dose-dependent manner. Heliangin inhibited TNF-α, NO, IL-6 and PGE2 expression levels in macrophage cells lysate. The immunocytochemistry assay showed the fluorescence image of heliangin treatment intercepted the p65 translocation process from outside to inside of nuclei triggered by LPS. Moreover, we founded that MAPK and NF-κB signaling pathway play important roles in heliangin's activity on RAW264.7 cells. Secondly, the acute toxic study results of heliangin manifested the safety in vivo. Heliangin exerted anti-inflammation effect in a xylene-induced ear swelling in BALB/C mice and carrageenan-induced paw edema model in SD rats. The cytokines levels (TNF-α, IL-6 and PGE2) were decreased. The paw tissue immunochemistry assay demonstrated the IL-6 protein level changes in carrageenan-induced paw edema model under heliangin administration.

Toxic effects of TiO2 nanoparticles in primary cultured rat sertoli cells are mediated via a dysregulated Ca2+ /PKC/p38 MAPK/NF-κB cascade

Although numerous studies have demonstrated that titanium dioxide nanoparticles (TiO₂ NPs) can be accumulated in various animal organs and can cause toxicity, there is currently only limited data regarding reproductive toxicity especially on the toxic mechanisms of TiO₂ NPs in Sertoli cells. In order to investigate the mechanism of reproductive toxicity, primary cultured rat Sertoli cells were exposed to 5, 15, or 30 μg/mL TiO₂ NPs for 24 h, and TiO₂ NPs internalization, expression of PKC (p-PKC) and p38 MAPK (p-p38 MAPK) as well as calcium homeostasis were examined. Our findings demonstrated that TiO₂ NPs crossed the membrane into the cytoplasm or nucleus, and significantly suppressed cell viability of primary cultured rat Sertoli cells in a concentration-dependent manner. Furthermore, immunological dysfunction caused by TiO₂ NPs was involved in the increased expression of NF-κB, TNF-α, and IL-1β, and decreased IκB expression. TiO₂ NPs significantly decreased Ca²⁺ -ATPase and Ca²⁺ /Mg²⁺ -ATPase activity and enhanced intracellular Ca²⁺ levels, and up-regulated the expression of p-PKC and p-p38 MAPK in a dose-dependent manner in primary cultured rat Sertoli cells. Taken together, these findings indicate that TiO₂ NPs may induce immunological dysfunction of primary cultured rat Sertoli cells by stimulating the Ca²⁺ /PKC/p38 MAPK cascade, which triggers NF-κB activation and ultimately induces the expression of inflammatory cytokines in primary cultured rat Sertoli cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1374-1382, 2017.

MicroRNA regulation in an animal model of acute ocular hypertension

Purpose

To analyse miRNA regulation in a rat model of acute ocular hypertension (AOH).

Methods

Acute ocular hypertension (AOH) was induced in the left eye of adult albino rats by inserting a cannula connected with a saline container into the anterior chamber. The contralateral eye served as a control. Seven days later, animals were killed. Retinas were used either for quantitative analysis of retinal ganglion cells (RGCs) and microglial cells or for miRNA array hybridization, qRT‐PCR and Western blotting.

Results

Anatomically, AOH caused axonal degeneration, a significant loss of RGCs and a significant increase in microglial cells in the ganglion cell layer. The miRNAs microarray analysis revealed 31 differentially expressed miRNAs in the AOH versus control group, and the regulation of 12 selected microRNAs was further confirmed by qRT‐PCR. Bioinformatic analysis indicates that several signalling pathways are putatively regulated by the validated miRNAs. Of particular interest was the inflammatory pathway signalled by mitogen‐activated protein kinases (MAPKs). In agreement with the in silico analysis, p38 MAP kinase, tumour necrosis factor‐alpha (TNF‐α) and iNOS proteins were significantly upregulated in the AOH retinas.

Conclusions

Acute IOP elevation led to changes in the expression of miRNAs, whose target genes were associated with the regulation of microglia‐mediated neuroinflammation or neural apoptosis. Addressing miRNAs in the process of retinal ischaemia and optic nerve damage in association with high IOP elevation may open new avenues in preventing retinal ganglion cell apoptosis and may serve as target for future therapeutic regimen in acute ocular hypertension and retinal ischaemic conditions.

Knockdown of NIK and IKKβ-Binding Protein (NIBP) Reduces Colorectal Cancer Metastasis through Down-Regulation of the Canonical NF-κΒ Signaling Pathway and Suppression of MAPK Signaling Mediated through ERK and JNK

BACKGROUND

Despite the identification of many signaling pathways involved in colorectal cancer (CRC) tumorigenesis, metastatic CRC still remains one of the major causes of cancer related death. NIK and IKKβ-binding protein (NIBP) is one of the key regulators of the NF-κB signaling pathway, which has been implicated in CRC metastasis. The aim of this study was to investigate the possible role of NIBP in CRC metastasis through its regulation of NF-κΒ and extracellular regulated kinase/c-Janus kinase (ERK/JNK) signaling pathways.

METHODS

In this study NIBP, phosphorylated (p)-p65, p-ERK1/2, and p-JNK1/2 expression was examined in 130 CRC, and 25 adenoma tissue samples were studied by immunohistochemistry. NIBP shRNA knockdown was performed in HCT116 cells, and NF-κB and ERK/JNK pathway activity was measured after TNF-α stimulation in vitro and in vivo.

RESULTS

We found that NIBP, p-p65, p-ERK1/2, and p-JNK1/2 expression was higher in late stages of CRC compared to early stages or adenomas. Expression of p-p65, p-IκBα, p-IκBβ, p-ERK1/2, and p-JNK1/2 was inhibited in TNF-α stimulated HCT116 cells following NIBP knockdown. Nevertheless, p-ERK1/2 expression in un-transfected and NIBP knockdown HCT116 cells remained the same in the absence of TNF-α stimulation. Furthermore, cell motility and invasion were reduced in HCT116 cells following NIBP knockdown even after TNF-α treatment. Finally, primary tumor weight and liver metastasis were reduced in nude mice with orthotopically transplanted NIBP knockdown of HCT116 cells.

CONCLUSION

In conclusion, we demonstrated that NIBP knockdown reduces colorectal cancer metastasis through down-regulation of canonical NF-κΒ signaling and suppression of ERK and JNK signaling.

Everolimus is better than rapamycin in attenuating neuroinflammation in kainic acid-induced seizures

Background

Microglia is responsible for neuroinflammation, which may aggravate brain injury in diseases like epilepsy. Mammalian target of rapamycin (mTOR) kinase is related to microglial activation with subsequent neuroinflammation. In the present study, rapamycin and everolimus, both as mTOR inhibitors, were investigated in models of kainic acid (KA)-induced seizure and lipopolysaccharide (LPS)-induced neuroinflammation.

Methods

In vitro, we treated BV2 cells with KA and LPS. In vivo, KA was used to induce seizures on postnatal day 25 in B6.129P-Cx3cr1^tm1Litt/J mice. Rapamycin and everolimus were evaluated in their modulation of neuroinflammation detected by real-time PCR, Western blotting, and immunostaining.

Results

Everolimus was significantly more effective than rapamycin in inhibiting iNOS and mTOR signaling pathways in both models of neuroinflammation (LPS) and seizure (KA). Everolimus significantly attenuated the mRNA expression of iNOS by LPS and nitrite production by KA and LPS than that by rapamycin. Only everolimus attenuated the mRNA expression of mTOR by LPS and KA treatment. In the present study, we also found that the modulation of mTOR under LPS and KA treatment was not mediated by Akt pathway but was primarily mediated by ERK phosphorylation, which was more significantly attenuated by everolimus. This inhibition of ERK phosphorylation and microglial activation in the hippocampus by everolimus was also confirmed in KA-treated mice.

Conclusions

Rapamycin and everolimus can block the activation of inflammation-related molecules and attenuated the microglial activation. Everolimus had better efficacy than rapamycin, possibly mediated by the inhibition of ERK phosphorylation. Taken together, mTOR inhibitor can be a potential pharmacological target of anti-inflammation and seizure treatment.

Neuronal Cell Death and Degeneration through Increased Nitroxidative Stress and Tau Phosphorylation in HIV-1 Transgenic Rats

The underlying mechanisms for increased neurodegeneration and neurocognitive deficits in HIV-infected people are unclear. Therefore, this study was aimed to investigate the mechanisms of increased neurodegeneration in 5-month old male HIV-1 Transgenic (Tg) rats compared to the age- and gender-matched wild-type (WT) by evaluating histological changes and biochemical parameters of the key proteins involved in the cell death signaling and apoptosis. Histological and immunohistochemical analyses revealed decreased neuronal cells with elevated astrogliosis in HIV-1 Tg rats compared to WT. Mechanistic studies revealed that increased levels of nitroxidative stress marker proteins such as NADPH-oxidase, cytochrome P450-2E1 (CYP2E1), inducible nitric oxide synthase (iNOS), the stress-activated mitogen-activated protein kinases such as JNK and p38K, activated cell-cycle dependent CDK5, hypoxia-inducible protein-1α, nitrated proteins, hyperphosphorylated tau, and amyloid plaques in HIV-Tg rats were consistently observed in HIV-1 Tg rats. Confocal microscopy and cell viability analyses showed that treatment with an antioxidant N-acetylcysteine or a specific inhibitor of iNOS 1400W significantly prevented the increased apoptosis of neuro-2A cells by HIV-1 Tat or gp120 protein, demonstrating the causal role of HIV-1 mediated nitroxidative stress and protein nitration in promoting neuronal cell death. Immunoprecipitation and immunoblot analysis confirmed nitration of Hsp90, evaluated as an example of nitrated proteins, suggesting possible involvement of nitrated proteins in neuronal damage. Further, activated p-JNK directly binds tau and phosphorylates multiple amino acids, suggesting an important role of p-JNK in tau hyperphosphorylation and tauopathy. These changes were accompanied with elevated levels of many apoptosis-related proteins Bax and cleaved (activated) caspase-3 as well as proinflammatory cytokines including TNF-α, IL-6 and MCP-1. Collectively, these results indicate that raised nitroxidative stress accompanied by elevated inflammation, cell death signaling pathway including activated p-JNK, C-terminal C99 amyloid fragment formation and tau hyperphosphorylation are responsible for increased apoptosis of neuronal cells and neurodegeneration in 5-month old HIV-Tg rats.

JNK activation is essential for activation of MEK/ERK signaling in IL-1β-induced COX-2 expression in synovial fibroblasts

The proinflammatory cytokine interleukin 1β (IL-1β) induces prostaglandin E₂ (PGE₂) production via upregulation of cyclooxygenase-2 (COX-2) expression in synovial fibroblasts. This effect of IL-1β is involved in osteoarthritis. We investigated MAPK signaling pathways in IL-1β-induced COX-2 expression in feline synovial fibroblasts. In the presence of MAPK inhibitors, IL-1β-induced COX-2 expression and PGE₂ release were both attenuated. IL-1β induced the phosphorylation of p38, JNK, MEK, and ERK1/2. A JNK inhibitor prevented not only JNK phosphorylation but also MEK and ERK1/2 phosphorylation in IL-1β-stimulated cells, but MEK and ERK1/2 inhibitors had no effect on JNK phosphorylation. A p38 inhibitor prevented p38 phosphorylation, but had no effect on MEK, ERK1/2, and JNK phosphorylation. MEK, ERK1/2, and JNK inhibitors had no effect on p38 phosphorylation. We also observed that in IL-1β-treated cells, phosphorylated MEK, ERK1/2, and JNK were co-precipitated with anti-phospho-MEK, ERK1/2, and JNK antibodies. The silencing of JNK1 in siRNA-transfected fibroblasts prevented IL-1β to induce phosphorylation of MEK and ERK1/2 and COX-2 mRNA expression. These observations suggest that JNK1 phosphorylation is necessary for the activation of the MEK/ERK1/2 pathway and the subsequent COX-2 expression for PGE₂ release, and p38 independently contributes to the IL-1β effect in synovial fibroblasts.