c-Jun N-terminal Kinase Signaling Research Articles

HDAC Inhibitor LBH589 Suppresses the Proliferation but Enhances the Antileukemic Effect of Human γδT Cells

γδT cells have potent effects on hematological malignancies, and their functions can be regulated by anti-tumor agents. Histone deacetylase inhibitors (HDACis) not only have antileukemic activity on leukemia but also affect immune cells during therapeutic application. In this in vitro study, we showed that LBH589, a pan-HDACi, impaired the proliferation of human γδT cells, as well as their proportions in peripheral blood mononuclear cells (PBMCs). At the specific concentration, LBH589 induced significant antileukemic activity of γδT cells against the HL-60 cells and Kasumi cells in a dose-dependent manner. However, the expression levels of activating receptor and molecules, as well as interferon-γ (IFN-γ) expression on γδT cells, were not affected by LBH589. After treatment with LBH589 for indicated times, extracellular-regulated protein kinase (ERK), Akt, and c-Jun N-terminal kinase (JNK) signaling pathways in γδT cells were not activated. In contrast, a stronger expression of Notch was observed and sustained for 72 h. Inhibition of Notch signaling by FLI-06, the γ-secretase inhibitor, significantly reversed the enhanced antileukemic ability of γδT cells induced by LBH589. For the first time, our investigations demonstrate that LBH589 can inhibit proliferation of γδT cells but facilitate their antileukemic effects via activation of Notch signaling.

D-serine Ameliorates Motor and Cognitive Impairments in β-amyloid 1-42 Injected Mice by Inhibiting JNK Signaling Pathway

The senile plaque formed by β-amyloid (Aβ) deposition in the brain is one of the main pathological features of Alzheimer’s disease (AD), and the c-Jun N-terminal kinase (JNK) signaling pathway plays an important role in the pathogenesis of AD. This study aimed to investigate that D-serine may ameliorate motor and cognitive impairment in Aβ injected mice by inhibiting JNK signaling pathway. Firstly, Kunming mice were injected intrahippocampally with Aβ1-42 to build AD model. The mice were injected intraperitoneally with saline, D-serine, D-amino acid oxidase (DAAO), and Sodium benzoate (BE) for 10 consecutive days, respectively. Subsequently, the motor and cognitive functions of mice were detected by behavioral tests. The silver staining and immunohistochemical methods were used to detect the distributions of Aβ in the hippocampus of mice. 18F-2-Fluro-D-deoxy-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) scans were performed to detected glucose metabolism of Aβ1-42 induced lesions. The expressions of relative JNK factors were detected by immunohistochemistry and Western blot methods. These results showed that Aβ severely impaired the motor and memory abilities of mice. The expressions of glial fibrillary acidic protein (GFAP), tumor necrosis factor (TNF-α), N-methyl-D-aspartate receptor 1 (NMDAR1), phospho-JNK (p-JNK), p-c-Jun and activating transcription factor 2 (ATF2) increased significantly. After D-serine treatment, the abilities of movement and memory of mice were improved, and the clearance rate of Aβ was accelerated. The expressions of GFAP, TNF-α, NMDAR1, p-JNK, p-c-Jun and ATF2 decreased significantly. DAAO and BE were administered to further validate these results. Therefore, this study showed that D-serine could alleviate the cognitive impairment of Aβ1-42 injected mice by inhibiting JNK signaling pathway. These results provide more evidences for the effect of D-serine on AD and relevant mechanism to treat AD.

Parthenolide Has Negative Effects on In Vitro Enhanced Osteogenic Phenotypes by Inflammatory Cytokine TNF-α via Inhibiting JNK Signaling.

Nuclear factor kappa B (NF-κB) regulates inflammatory gene expression and represents a likely target for novel disease treatment approaches, including skeletal disorders. Several plant-derived sesquiterpene lactones can inhibit the activation of NF-κB. Parthenolide (PTL) is an abundant sesquiterpene lactone, found in Mexican Indian Asteraceae family plants, with reported anti-inflammatory activity, through the inhibition of a common step in the NF-κB activation pathway. This study examined the effects of PTL on the enhanced, in vitro, osteogenic phenotypes of human periosteum-derived cells (hPDCs), mediated by the inflammatory cytokine tumor necrosis factor (TNF)-α. PTL had no significant effects on hPDC viability or osteoblastic activities, whereas TNF-α had positive effects on the in vitro osteoblastic differentiation of hPDCs. c-Jun N-terminal kinase (JNK) signaling played an important role in the enhanced osteoblastic differentiation of TNF-α-treated hPDCs. Treatment with 1 µM PTL did not affect TNF-α-treated hPDCs; however, 5 and 10 µM PTL treatment decreased the histochemical detection and activity of alkaline phosphatase (ALP), alizarin red-positive mineralization, and the expression of ALP and osteocalcin mRNA. JNK phosphorylation decreased significantly in TNF-α-treated hPDCs pretreated with PTL. These results suggested that PTL exerts negative effects on the increased osteoblastic differentiation of TNF-α-treated hPDCs by inhibiting JNK signaling.

Phanginin R Induces Cytoprotective Autophagy via JNK/c-Jun Signaling Pathway in Non-Small Cell Lung Cancer A549 Cells.

Cassane-type diterpenoids are widely distributed in the medical plants of genus Caesalpinia. To date, plenty of cassane diterpenoids have been isolated from the genus Caesalpinia, and some of them were documented to exhibit multiple biological activities. However, the effects of these compounds on autophagy have never been reported. To investigate the effects and mechanisms of the cassane diterpenoids including Phanginin R (PR) on autophagy in Non-Small Cell Lung Cancer (NSCLC) A549 cells. Western blot analysis and immunofluorescence assay were performed to investigate the effects of the compounds on autophagic flux in A549 cells. The pathway inhibitor and siRNA interference were used to investigate the mechanism of PR. MTT assay was performed to detect cell viability. PR treatment upregulated the expression of phosphatidylethanolamine-modified microtubule-associated protein Light-Chain 3 (LC3-II) in A549 cells. Immunofluorescence assay showed that PR treatment increased the production of red-fluorescent puncta in mRFP-GFP-LC3 plasmid-transfected cells, indicating PR promoted autophagic flux in A549 cells. PR treatment activated the c-Jun N-terminal Kinase (JNK) signaling pathway while it did not affect the classical Akt/mammalian Target of Rapamycin (mTOR) pathway. Pretreatment with the JNK inhibitor SP600125 or siRNA targeting JNK or c-Jun suppressed PR-induced autophagy. In addition, cotreatment with the autophagy inhibitor Chloroquine (CQ) or inhibition of the JNK/c-Jun signaling pathway increased PR-induced cytotoxicity. PR induced cytoprotective autophagy in NSCLC A549 cells via the JNK/c-Jun signaling pathway, and autophagy inhibition could further improve the anti-cancer potential of PR.

Regulation of Mitogen-Activated Protein Kinase Signaling Pathway and Proinflammatory Cytokines by Ursolic Acid in Murine Macrophages Infected with Mycobacterium avium

Mycobacterium avium, one of the closest relatives of Mycobacterium tuberculosis (MTB), offers an advantage in studying MTB because of its tuberculosis-like effect in humans and host immune tolerance. This study examined the antimycobacterial action of ursolic acid and its regulation in macrophages during infection. Colonyforming units of the bacteria were determined in the cell lysate of macrophages and in the supernatant. The effect of ursolic acid on macrophages during infection was determined by analyzing the phosphorylation of the mitogen-activated protein kinase signaling pathway and the concentrations of tumor necrosis factor-α, interleukin-1β, interleukin-6, and nitrite. The colony-forming units analysis demonstrated that ursolic acid reduced the presence of Mycobacterium avium both intracellularly (in macrophages) and extracellularly. It decreased the levels of tumor necrosis factor- α and interleukin-6 but increased the concentrations of interleukin-1β and nitrite during infection. It also inhibited the phosphorylation of ERK1/2 but phosphorylated the C-Jun N-terminal kinase signaling pathway. The antimycobacterial effect of ursolic acid correlated with its ability to regulate the activation of macrophages. This dual ability made the ursolic acid-related elimination of the mycobacteria more effective.

JNK inhibition alleviates oxidative DNA damage, germ cell apoptosis, and mitochondrial dysfunction in testicular ischemia reperfusion injury.

The aim of this study is to determine whether the c-Jun N-terminal kinase (JNK) signaling is a regulator of oxidative DNA damage, germ cell apoptosis (GCA), and mitochondrial dysfunction during testicular ischemia reperfusion injury (tIRI) using the JNK inhibitor SP600125. Male Sprague Dawley rats (n = 36) were equally divided into three groups: sham, tIRI only, and tIRI + SP600125 (15mg/kg). Testicular ischemia was induced for 1h followed by 4h of reperfusion prior to animal sacrifice. Spermatogenesis was evaluated by light microscopy, while expression of oxidative stress and GCA-related mRNAs and proteins were evaluated by real-time polymerase chain reaction and colorimetric assays, respectively. Expressions of JNK, p53, and survivin were detected by immunofluorescence (IF) staining. Indicators of mitochondrial dysfunction were examined by western blot analysis and colorimetric assay. In comparison to sham, the tIRI testes showed a significant increase in lipid and protein oxidation products. Oxidative DNA damage was reflected by a significant increase in the number of DNA strand breaks, increased concentration of 8-OHdG, and elevated poly (ADP-ribose) polymerase activity. Spermatogenic damage was associated with the activation of caspase 3 and elevated Bax to Bcl2 ratio. This was also accompanied by a significantly heightened IF expression of the phosphorylated forms of JNK and p53 paralled with the suppression of survivin. Mitochondrial dysfunction was reflected by NAD+ depletion, overexpression of uncoupling protein 2, and increased level of cytochrome c. Such tIRI-induced modulations were all attenuated by SP600125 treatment prior to reperfusion. In conclusion, JNK signaling regulates oxidative DNA damage, GCA, and mitochondrial dysfunction through activation of p53 and suppression of survivin during tIRI.

Combination therapy of BCR-ABL-positive B cell acute lymphoblastic leukemia by tyrosine kinase inhibitor dasatinib and c-JUN N-terminal kinase inhibition

BackgroundThe Philadelphia chromosome (Ph), which leads to the creation and expression of the fusion gene product BCR-ABL, underlines the pathogenesis of chronic myelogenous leukemia (CML) and a fraction of adult and pediatric acute B-lymphoblastic leukemia (B-ALL). The BCR-ABL tyrosine kinase inhibitors (TKIs) have shown a remarkable clinical activity in patients with CML, but their efficacy in treating Ph+ B-ALL is limited. Identifying additional therapeutic targets is important for the effective treatment of Ph+ B-ALL.MethodsActivation of the JNK signaling pathway in human and mouse BCR-ABL+ B-ALL cells with or without dasatinib treatment was analyzed by Western blotting. JNK was inhibited either by RNA interference or chemical inhibitors, such as JNK-IN-8. The effect of JNK inhibition with or without BCR-ABL TKI dasatinib on BCR-ABL+ B-ALL cells was analyzed by the CellTiter-Glo® Luminescent Cell Viability Assay. The in vivo effects of JNK-IN-8 and dasatinib alone or in combination were tested using a BCR-ABL induced B-ALL mouse model.ResultsWe found that the c-JUN N-terminal kinase (JNK) signaling pathway is abnormally activated in both human and mouse BCR-ABL+ B-ALL cells, but the BCR-ABL TKI does not inhibit JNK activation in these cells. Inhibition of JNK, either by RNAi-mediated downregulation or by JNK inhibitors, could significantly reduce viability of Ph+ B-ALL cells. JNK inhibition by RNAi-mediated downregulation or JNK inhibitors also showed a synergistic effect with the BCR-ABL TKI, dasatinib, in killing Ph+ B-ALL cells in vitro. Furthermore, a potent JNK inhibitor, JNK-IN-8, in combination with dasatinib markedly improved the survival of mice with BCR-ABL induced B-ALL, as compared to the treatment with dasatinib alone.ConclusionsOur findings indicate that simultaneously targeting both BCR-ABL and JNK kinase might serve as a promising therapeutic strategy for Ph+ B-ALL.

Roles of JNK/Nrf2 Pathway on Hemin-Induced Heme Oxygenase-1 Activation in MCF-7 Human Breast Cancer Cells.

Heme oxygenase-1 (HO-1) is highly induced in various human disease states, including cancer, indicating that HO-1 is an emerging target of cancer therapy. In this study, we investigated that the mechanisms of hemin-induced HO-1 expression and its signaling pathways in human breast cancer cell. We used MCF-7 cells, a human breast cancer cell line. Hemin increased HO-1 expression in MCF-7 cells in a dose- and time-dependent manner. Hemin enhanced HO-1 expression through the activation of c-Jun N-terminal kinases (JNK) signaling pathway. Hemin also induced activation of Nrf2, a major transcription factor of HO-1 expression. These responses in MCF-7 cells were completely blocked by pretreatment with brazilin, a HO-1 regulator. These results indicated that brazilin inhibits hemin-induced HO-1 expressions through inactivation of JNK/Nrf2 in MCF-7 cells. Thus, our findings suggest that HO-1 is an important anticancer-target of brazilin in human breast cancer.

Activation of JNK signaling promotes all-trans-retinal–induced photoreceptor apoptosis in mice

Disrupted clearance of all-trans-retinal (atRAL), a component of the visual (retinoid) cycle in the retina, may cause photoreceptor atrophy in autosomal recessive Stargardt disease (STGD1) and dry age-related macular degeneration (AMD). However, the mechanisms underlying atRAL-induced photoreceptor loss remain elusive. Here, we report that atRAL activates c-Jun N-terminal kinase (JNK) signaling at least partially through reactive oxygen species production, which promoted mitochondria-mediated caspase- and DNA damage-dependent apoptosis in photoreceptor cells. Damage to mitochondria in atRAL-exposed photoreceptor cells resulted from JNK activation, leading to decreased expression of Bcl2 apoptosis regulator (Bcl2), increased Bcl2 antagonist/killer (Bak) levels, and cytochrome c (Cyt c) release into the cytosol. Cytosolic Cyt c specifically provoked caspase-9 and caspase-3 activation and thereby initiated apoptosis. Phosphorylation of JNK in atRAL-loaded photoreceptor cells induced the appearance of γH2AX, a sensitive marker for DNA damage, and was also associated with apoptosis onset. Suppression of JNK signaling protected photoreceptor cells against atRAL-induced apoptosis. Moreover, photoreceptor cells lacking Jnk1 and Jnk2 genes were more resistant to atRAL-associated cytotoxicity. The Abca4-/-Rdh8-/- mouse model displays defects in atRAL clearance that are characteristic of STGD1 and dry AMD. We found that JNK signaling was activated in the neural retina of light-exposed Abca4-/-Rdh8-/- mice. Of note, intraperitoneal administration of JNK-IN-8, which inhibits JNK signaling, effectively ameliorated photoreceptor degeneration and apoptosis in light-exposed Abca4-/-Rdh8-/- mice. We propose that pharmacological inhibition of JNK signaling may represent a therapeutic strategy for preventing photoreceptor loss in retinopathies arising from atRAL overload.

JNK Signaling Pathway Suppresses LPS-Mediated Apoptosis of HK-2 Cells by Upregulating NGAL.

Objective To explore the role of the c-Jun N-terminal kinase (JNK) signaling pathway in upregulated NGAL expression and its antiapoptotic mechanism in lipopolysaccharide (LPS)-mediated renal tubular epithelial cell injury. Methods In vitro, HK-2 cells were divided into five groups (Con, LPS 1 h, LPS 3 h, LPS 6 h, and LPS 12 h groups) based on the time of LPS (10 μM) treatment. NGAL and caspase-3 gene expression levels were detected by RT-PCR to assess dynamic changes. HK-2 cells were pretreated with SP600125 (20 μM) for 2 hours, followed by LPS (10 μM) stimulation for 3 hours. NGAL and caspase-3 gene expression levels were then determined. Results NGAL mRNA was increased significantly within 6 hours, and caspase-3 mRNA was increased within 3 hours after treatment (P < 0.05). Correlation analysis showed a high correlation between their expression (r = 0.448, P < 0.05). After pretreatment with SP600125, mRNA expression of NGAL in the LPS group was inhibited, while that of caspase-3 was increased significantly. The NGAL mRNA expression level in the SB + LPS group was decreased significantly compared with that in the LPS group, but it was slightly higher than that in the SP group (∼1.5 times of that in the Con group). However, caspase-3 mRNA expression was increased significantly in the SB + LPS group (P < 0.001) (3.5 times of that in the Con group). It also showed a significant increase compared with SP and LPS groups (P < 0.001 vs. SB group; P < 0.05 vs. LPS group). We also found that NGAL and caspase 3 proteins were increased significantly in LPS and SP + LPS groups, but SP600125 decreased the NGAL level by almost 35% and increased the caspase 3 level by 50% in the SP + LPS group compared with the LPS group (P < 0.05). Conclusions The JNK signaling pathway inhibits LPS-mediated apoptosis of renal tubular epithelial cells by upregulating NGAL.

α-Bisabolol suppresses the inflammatory response and ECM catabolism in advanced glycation end products-treated chondrocytes and attenuates murine osteoarthritis

As a chronic musculoskeletal degeneration disease, osteoarthritis (OA) clinically manifests as joint pain, stiffness and a limited range of movement. OA has affected the life quality of at least one-tenth of the population but lacks satisfactory treatments. α-Bisabolol (BISA) is a small oily sesquiterpene alcohol widely found in essential oils of chamomile (Matricaria recutita), salvia and wood of Candeia and has multiple biological properties, particularly an anti-inflammatory effect. The purpose of this study is to assess the anti-inflammatory and chondroprotective effect of BISA in OA progression and explore its underlying mechanism. We isolated human chondrocytes and treated them with advanced glycation end products (AGEs) to imitate OA progression in vitro. BISA pretreatment suppressed the AGE-induced inflammatory reaction and extracellular matrix (ECM) degeneration by blocking nuclear factor kappa B (NF-κB), p38 and c-Jun N-terminal kinase (JNK) signaling. Moreover, a mouse destabilization of the medial meniscus (DMM) model was established by surgery to investigate BISA protection in vivo. BISA administration attenuated DMM-induced radiological and histopathological changes relative to the DMM group and resulted in lower OARSI scores. Taken together, the results of our study indicate the potential of BISA in OA therapy.

Mst1 knockdown alleviates cardiac lipotoxicity and inhibits the development of diabetic cardiomyopathy in db/db mice

Diabetic cardiomyopathy (DCM) accounts for increasing deaths of diabetic patients, and effective therapeutic targets are urgently needed. Myocardial lipotoxicity, which is caused by cardiac non-oxidative metabolic fatty acids and cardiotoxic fatty acid metabolites accumulation, has gained more attention to explain the increasing prevalence of DCM. However, whether mammalian Ste20-like kinase 1 (Mst1) plays a role in lipotoxicity in type 2 diabetes-induced cardiomyopathy has not yet been illustrated. Here, we found that Mst1 expression was elevated transcriptionally in the hearts of type 2 diabetes mellitus mice and palmitic acid-treated neonatal rat ventricular myocytes. Adeno-associated virus 9 (AAV9)-mediated Mst1 silencing in db/db mouse hearts significantly alleviated cardiac dysfunction and fibrosis. Notably, Mst1 knockdown in db/db mouse hearts decreased lipotoxic apoptosis and inflammatory response. Mst1 knockdown exerted protective effects through inactivation of MAPK/ERK kinase kinase 1 (MEKK1)/c-Jun N-terminal kinase (JNK) signaling pathway. Moreover, lipotoxicity induced Mst1 expression through promoting the binding of forkhead box O3 (FoxO3) and Mst1 promoter. Conclusively, we elucidated for the first time that Mst1 expression is regulated by FOXO3 under lipotoxicity stimulation and downregulation of Mst1 protects db/db mice from lipotoxic cardiac injury through MEKK1/JNK signaling inhibition, indicating that Mst1 abrogation may be a potential treatment strategy for DCM in type 2 diabetic patients.

Vestigial suppresses apoptosis and cell migration in a manner dependent on the level of JNK-Caspase signaling in the Drosophila wing disc.

The Decapentaplegic (Dpp) and Wingless (Wg) signal pathways play important roles in numerous biological processes in Drosophila. The Drosophila vestigial (vg) gene is selectively required for wing imaginal disc cell proliferation, which is essential for the formation of the adult wing and halter structures, and is regulated by Dpp and Wg signaling. Using a Drosophila invasion model of wing epithelium, we showed herein that inhibition of Dpp or Wg signaling promoted cells to migrate across the cell lineage restrictive anterior/posterior (A/P) compartment boundary. Being downstream of both Dpp and Wg signaling, vg can block cell migration induced by loss of either pathway. In addition, suppression of vg is sufficient to induce cell migration across the A/P boundary. Transcriptomic analysis revealed potential downstream genes involved in the cell migration after suppressing vg in the wing disc. We further demonstrated that the c-Jun N-terminal kinase (JNK) signaling promoted cell migration induced by vg suppression by upregulating Caspase activity. Taken together, our results revealed the requirement of Vg for suppressing cell migration and clarified how developmental signals collaborate to stabilize cells along the compartment boundary.

Piceatannol attenuates fat accumulation and oxidative stress in steatosis-induced HepG2 cells

Non-alcoholic fatty liver disease (NAFLD), which affects over 20% of the adult population, is the most common liver disease worldwide and can progress to inflammatory hepatitis, cirrhosis and liver cancer. The need to alleviate NAFLD is imperative, but there are limited pharmacological therapies available. Based on previous reports that piceatannol, a stilbenoid metabolite of resveratrol, exhibits anti-obesity, antioxidant and anti-inflammatory effects, the goal of this study was to determine the efficacy of piceatannol on prevention and/or treatment of NAFLD. The results showed that piceatannol significantly decreased fat accumulation and suppressed lipogenesis and fatty acids (FAs) uptake by decreasing sterol regulatory element-binding protein 1 (SREBP1) and cluster of differentiation 36 (CD36) in steatosis-induced HepG2 hepatocytes. Piceatannol treatment also promoted FAs β-oxidation by increasing farnesoid X receptor (FXR), peroxisome proliferator-activated receptor α (PPARα), and carnitine palmitoyltransferase 1α (CPT1α) under steatosis conditions. Moreover, piceatannol significantly suppressed FA-induced oxidative stress and inhibited phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal–regulated kinases 1/2 (ERK1/2). Overall, it is suggested that piceatannol reduced fat accumulation in steatosis-induced HepG2 cells by suppressing lipogenesis (SREBP1 and ACC) and FA uptake (CD36), and promoting FAs oxidation (FXR, PPARα and CPT1α).

Research on mechanism of sevoflurane in alleviating cerebral ischemia-reperfusion injury in rats through JNK signaling pathway.

To explore the specific mechanism of sevoflurane in alleviating cerebral ischemia-reperfusion injury (CIRI) in rats through the c-Jun N-terminal kinase (JNK) signaling pathway. A total of 60 male specific pathogen-free Sprague-Dawley rats were randomly divided into sham group (n=20), model group (n=20), and sevoflurane group (n=20). In the sevoflurane group, sevoflurane (2.5%) was inhaled for 60 min at 24 h before the blockage of cerebral blood supply. The CIRI model was established using the suture method in the model group and sevoflurane group, while the right common carotid artery and external carotid artery were separated and ligated only, without suture placement, in the sham group. At 24 h after reperfusion, the neurological deficit score in each group was calculated, the water content in brain tissues in each group was detected based on dry-wet weight ratio, the infarction volume of brain tissues in each group was detected via 2,3,5-triphenyltetrazolium chloride (TTC) staining, and the apoptosis rate of brain cells in each group was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Moreover, the protein levels of JNK, p-JNK, B-cell lymphoma-2 (Bcl-2), and the Bcl-2 associated X protein (Bax) in brain tissues were determined using Western blotting, and the gene expressions of Bax and Bcl-2 in brain tissues were determined through fluorescence quantitative Polymerase Chain Reaction (qPCR). It was found that the water content in brain tissues and the cerebral infarction volume were significantly increased in the model group compared with those in the sham group (p<0.01, p<0.01), while they were notably decreased in the sevoflurane group compared with those in the model group (p<0.05, p<0.01). The neurological deficit score was significantly higher in the model group than that in the sham group (p<0.01), while it was remarkably lower in the sevoflurane group than that in the model group (p<0.01). According to the results of the TUNEL assay, the model group had an evidently higher apoptosis rate of brain cells than the sham group (p<0.01), while the sevoflurane group had a lower apoptosis rate of brain cells than the model group (p<0.05). Besides, the results of Western blotting revealed that the model group exhibited remarkably increased protein levels of JNK, p-JNK, and Bax (p<0.05, p<0.01, p<0.01) and a remarkably decreased protein level of Bcl-2 (p<0.01) compared with the sham group. Sevoflurane group had decreased protein levels of JNK, p-JNK, and Bax (p<0.05, p<0.01, p<0.01) and an increased protein level of Bcl-2 (p<0.05) in comparison with the model group. In addition, the gene expression of Bcl-2 significantly declined (p<0.01), and that of Bax remarkably rose (p<0.01) in the model group compared with those in the sham group, while the contrary is the case in the sevoflurane group compared with those in the model group (p<0.05, p<0.01). Sevoflurane can regulate the protein and gene expressions of Bax and Bcl-2 and reduce apoptosis in CIRI by regulating the JNK signaling pathway, thereby exerting a protective effect on brain tissues and improving the symptoms of neurological deficit.

Resveratrol Preincubation Enhances the Therapeutic Efficacy of hUC-MSCs by Improving Cell Migration and Modulating Neuroinflammation Mediated by MAPK Signaling in a Mouse Model of Alzheimer's Disease.

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are promising for the treatment of Alzheimer’s disease (AD). However, their low rate of migration and survival in the brain limit their clinical applicability. This study is designed to improve the therapeutic potential of hUC-MSCs by preincubating them with resveratrol, a natural polyphenol capable of regulating cell destiny. Herein, we demonstrate that resveratrol preincubation enhances the migration of hUC-MSCs in vitro, as well as their survival and homing into the hippocampus of AD mice in vivo. Moreover, resveratrol-primed MSCs were better able to inhibit amyloid-β peptide (Aβ) deposition, Tau hyperphosphorylation, and oxidative stress, all while improving learning and memory. Notably, we found that hUC-MSCs inhibited neuroinflammation by reacting with astrocytes and microglial cells and suppressing mitogen-activated protein kinases (MAPKs), extracellular signal kinases (ERK), p38 kinases (p38), and c-Jun N-terminal kinases (JNK) signaling pathways in the hippocampus of AD mice. Furthermore, resveratrol pretreatment enhanced these effects. Conclusively, the current study revealed that resveratrol preconditioning protected hUC-MSCs against the hostile microenvironment characteristic of AD and enhanced their viability and homing into the brain of AD mice. The use of resveratrol-pretreated hUC-MSCs is thereby proposed to be a promising therapy for AD.

Sickle Cell Anemia Mediates Carotid Artery Expansive Remodeling That Can Be Prevented by Inhibition of JNK (c-Jun N-Terminal Kinase).

Sickle cell anemia (SCA) causes chronic inflammation and multiorgan damage. Less understood are the arterial complications, most evident by increased strokes among children. Proteolytic mechanisms, biomechanical consequences, and pharmaceutical inhibitory strategies were studied in a mouse model to provide a platform for mechanistic and intervention studies of large artery damage due to sickle cell disease. Approach and Results: Townes humanized transgenic mouse model of SCA was used to test the hypothesis that elastic lamina and structural damage in carotid arteries increased with age and was accelerated in mice homozygous for SCA (sickle cell anemia homozygous genotype [SS]) due to inflammatory signaling pathways activating proteolytic enzymes. Elastic lamina fragmentation observed by 1 month in SS mice compared with heterozygous littermate controls (sickle cell trait heterozygous genotype [AS]). Positive immunostaining for cathepsin K, a powerful collagenase and elastase, confirmed accelerated proteolytic activity in SS carotids. Larger cross-sectional areas were quantified by magnetic resonance angiography and increased arterial compliance in SS carotids were also measured. Inhibiting JNK (c-jun N-terminal kinase) signaling with SP600125 significantly reduced cathepsin K expression, elastin fragmentation, and carotid artery perimeters in SS mice. By 5 months of age, continued medial thinning and collagen degradation was mitigated by treatment of SS mice with JNK inhibitor. Arterial remodeling due to SCA is mediated by JNK signaling, cathepsin proteolytic upregulation, and degradation of elastin and collagen. Demonstration in Townes mice establishes their utility for mechanistic studies of arterial vasculopathy, related complications, and therapeutic interventions for large artery damage due to SCA.

Disulfiram/copper markedly induced myeloma cell apoptosis through activation of JNK and intrinsic and extrinsic apoptosis pathways

Disulfiram (DSF) is an FDA approved anti-alcoholism drug in use for more than 60 years. Recently, antitumor activity of the DSF/copper (DSF/Cu) complex has been identified. Its anti-multiple myeloma activity, however, has barely been investigated. In the present study, our results demonstrated that the DSF/Cu complex induced apoptosis of MM cells and MM primary cells. The results indicated that DSF/Cu significantly induced cell cycle arrest at the G2/M phase in MM.1S and RPMI8226 cells. Moreover, JC-1 and Western blot results showed that DSF/Cu disrupted mitochondrial membrane integrity and cleaved caspase-8 in MM cells, respectively, suggesting that it induced activation of extrinsic and intrinsic apoptosis pathways. Interestingly, DSF/Cu induced caspase-3 activation was partly blocked by Z-VAD-FMK (zVAD), a pan-caspase inhibitor, indicating at caspase-dependent and -independent paths involved in DSF/Cu induced myeloma cell apoptosis machinery. Additionally, activation of the c-Jun N-terminal kinase (JNK) signaling pathway was observed in DSF/Cu treated MM cells. More importantly, our results demonstrated that DSF/Cu significantly reduced tumor volumes and prolonged overall survival of MM bearing mice when compared with the controls. Taken together, our novel findings showed that DSF/Cu has potent anti-myeloma activity in vitro and in vivo highlighting valuable clinical potential of DSF/Cu in MM treatment.

XRP44X Enhances the Cytotoxic Activity of Natural Killer Cells by Activating the c-JUN N-Terminal Kinase Signaling Pathway.

Natural killer (NK) cells are innate lymphocytes that play an essential role in preventing cancer development by performing immune surveillance to eradicate abnormal cells. Since ex vivo expanded NK cells have cytotoxic activity against various cancers, including breast cancers, their clinical potential as immune-oncogenic therapeutics has been widely investigated. Here, we report that the pyrazole chemical XRP44X, an inhibitor of Ras/ERK activation of ELK3, stimulates NK-92MI cells to enhance cytotoxic activity against breast cancer cells. Under XRP44X stimulation, NK cells did not show notable apoptosis or impaired cell cycle progression. We demonstrated that XRP44X enhanced interferon gamma expression in NK-92MI cells. We also elucidated that potentiation of the cytotoxic activity of NK-92MI cells by XRP44X is induced by activation of the c-JUN N-terminal kinase (JNK) signaling pathway. Our data provide insight into the evaluation of XRP44X as an immune stimulant and that XRP44X is a potential candidate compound for the therapeutic development of NK cells.

11-Methoxytabersonine Induces Necroptosis with Autophagy through AMPK/mTOR and JNK Pathways in Human Lung Cancer Cells.

Aspidosperma alkaloids, a subclass of monoterpenoid indole alkaloids rich in the Apocynaceae plants, possess remarkable antitumor activities, but the underlying mechanisms have rarely been reported. In the current project, 11-methoxytabersonine (11-MT), an aspidosperma-type alkaloid isolated from Tabernaemontana bovina, significantly inhibited the viability of two human lung cancer cell lines A549 and H157, and the molecular mechanisms were thus investigated. The results showed that 11-MT killed lung cancer cells via induction of necroptosis in an apoptosis-independent manner. In addition, 11-MT strongly induced autophagy in the two cell lines, which played a protective role against 11-MT-induced necroptosis. Finally, the autophagy caused by 11-MT was found to be via activation of the AMP activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) and the c-Jun N-terminal kinase (JNK) signaling pathways in both cells. Taken together, 11-MT exhibited an antitumor mechanism different from that of previously reported analogues and could have the potential to serve as a lead compound for the development of new chemotherapy for lung cancer.