The phosphatidylinositol 3-kinase/Akt and c-Jun N-terminal kinase signaling in cancer: Alliance or contradiction? (Review)

Prevention of age-related neuromuscular junction degeneration in sarcopenia by low-magnitude high-frequency vibration

Neuromuscular junction (NMJ) degeneration is one of pathological factors of sarcopenia. Low-magnitude high-frequency vibration (LMHFV) was reported effective in alleviating the sarcopenia progress. However, no previous study has investigated treatment effects of LMHFV targeting NMJ degeneration in sarcopenia. We first compared morphological differences of NMJ between sarcopenic and non-sarcopenic subjects, as well as young and old C57BL/6 mice. We then systematically characterized the age-related degeneration of NMJ in SAMP8 against its control strain, SAMR1 mice, from 3 to 12 months old. We also investigated effects of LMHFV in SAMP8 on the maintenance of NMJ during the onset of sarcopenia with respect to the Agrin-LRP4-MuSK-Dok7 pathway and investigated the mechanism related to ERK1/2 signaling. We observed sarcopenic/old NMJ presented increased acetylcholine receptors (AChRs) cluster fragmentation and discontinuity than non-sarcopenic/young NMJ. In SAMP8, NMJ degeneration (morphologically at 6 months and functionally at 8 months) was observed associated with the sarcopenia onset (10 months). SAMR1 showed improved NMJ morphology and function compared with SAMP8 at 10 months. Skeletal muscle performance was improved at Month 4 post-LMHFV treatment. Vibration group presented improved NMJ function at Months 2 and 6 posttreatment, accompanied with alleviated morphological degeneration at Month 4 posttreatment. LMHFV increased Dok7 expression at Month 4 posttreatment. In vitro, LMHFV could promote AChRs clustering in myotubes by increasing Dok7 expression through suppressing ERK1/2 phosphorylation. In conclusion, NMJ degeneration was observed associated with the sarcopenia onset in SAMP8. LMHFV may attenuate NMJ degeneration and sarcopenia progression by increasing Dok7 expression through suppressing ERK1/2 phosphorylation.

Current state of knowledge of triclosan (TCS)-dependent reactive oxygen species (ROS) production

Triclosan (TCS) is widely used in a number of industrial and personal care products. This molecule can induce reactive oxygen species (ROS) production in various cell types, which results in diverse types of cell responses. Therefore, the aim of the present study was to summarize the current state of knowledge of TCS-dependent ROS production and the influence of TCS on antioxidant enzymes and pathways. To date, the TCS mechanism of action has been widely investigated in non-mammalian organisms that may be exposed to contaminated water and soil, but there are also in vivo and in vitro studies on plants, algae, mammalians, and humans. This literature review has revealed that mammalian organisms are more resistant to TCS than non-mammalian organisms and, to obtain a toxic effect, the effective TCS dose must be significantly higher. The TCS-dependent increase in the ROS level causes damage to DNA, protein, and lipids, which together with general oxidative stress leads to cell apoptosis or necrosis and, in the case of cancer cells, faster oncogenesis and even initiation of oncogenic transformation in normal human cells. The review presents the direct and indirect TCS action through different receptor pathways.

BMPR2 Loss Activates AKT by Disrupting DLL4/NOTCH1 and PPARγ Signaling in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive cardiopulmonary disease characterized by pathologic vascular remodeling of small pulmonary arteries. Endothelial dysfunction in advanced PAH is associated with proliferation, apoptosis resistance, and endothelial to mesenchymal transition (EndoMT) due to aberrant signaling. DLL4, a cell membrane associated NOTCH ligand, plays a pivotal role maintaining vascular integrity. Inhibition of DLL4 has been associated with the development of pulmonary hypertension, but the mechanism is incompletely understood. Here we report that BMPR2 silencing in pulmonary artery endothelial cells (PAECs) activated AKT and suppressed the expression of DLL4. Consistent with these in vitro findings, increased AKT activation and reduced DLL4 expression was found in the small pulmonary arteries of patients with PAH. Increased NOTCH1 activation through exogenous DLL4 blocked AKT activation, decreased proliferation and reversed EndoMT. Exogenous and overexpression of DLL4 induced BMPR2 and PPRE promoter activity, and BMPR2 and PPARG mRNA in idiopathic PAH (IPAH) ECs. PPARγ, a nuclear receptor associated with EC homeostasis, suppressed by BMPR2 loss was induced and activated by DLL4/NOTCH1 signaling in both BMPR2-silenced and IPAH ECs, reversing aberrant phenotypic changes, in part through AKT inhibition. Directly blocking AKT or restoring DLL4/NOTCH1/PPARγ signaling may be beneficial in preventing or reversing the pathologic vascular remodeling of PAH.

Review: The PI3K-AKT-mTOR signal transduction pathway in canine cancer

Tumors in dogs and humans share many similar molecular and genetic features, incentivizing a better understanding of canine neoplasms not only for the purpose of treating companion animals, but also to facilitate research of spontaneously developing tumors with similar biologic behavior and treatment approaches in an immunologically competent animal model. Multiple tumor types of both species have similar dysregulation of signal transduction through phosphatidylinositol 3-kinase (PI3K), protein kinase B (PKB; AKT), and mechanistic target of rapamycin (mTOR), collectively known as the PI3K-AKT-mTOR pathway. This review aims to delineate the pertinent aspects of the PI3K-AKT-mTOR signaling pathway in health and in tumor development. It will then present a synopsis of current understanding of PI3K-AKT-mTOR signaling in important canine cancers and advancements in targeted inhibitors of this pathway.

A role for TGFβ signaling in Gli1+ tendon and enthesis cells

The development of musculoskeletal tissues such as tendon, enthesis, and bone relies on proliferation and differentiation of mesenchymal progenitor cells. Gli1+ cells have been described as putative stem cells in several tissues and are presumed to play critical roles in tissue formation and maintenance. For example, the enthesis, a fibrocartilage tissue that connects tendon to bone, is mineralized postnatally by a pool of Gli1+ progenitor cells. These cells are regulated by hedgehog signaling, but it is unclear if TGFβ signaling, necessary for tenogenesis, also plays a role in their behavior. To examine the role of TGFβ signaling in Gli1+ cell function, the receptor for TGFβ, TbR2, was deleted in Gli1-lineage cells in mice at P5. Decreased TGFβ signaling in these cells led to defects in tendon enthesis formation by P56, including defective bone morphometry underlying the enthesis and decreased mechanical properties. Immunohistochemical staining of these Gli1+ cells showed that loss of TGFβ signaling reduced proliferation and increased apoptosis. In vitro experiments using Gli1+ cells isolated from mouse tail tendons demonstrated that TGFβ controls cell proliferation and differentiation through canonical and non-canonical pathways and that TGFβ directly controls the tendon transcription factor scleraxis by binding to its distant enhancer. These results have implications in the development of treatments for tendon and enthesis pathologies.

ABT199/venetoclax synergism with thiotepa enhances the cytotoxicity of fludarabine, cladribine and busulfan in AML cells

ABT199/venetoclax, an inhibitor of the pro-survival BCL-2 protein, has improved AML treatment. Its efficacy in hematopoietic stem cell transplantation (HSCT), when combined with other chemotherapeutic drugs, has not been thoroughly investigated. The present study demonstrates the synergistic cytotoxicity of ABT199/venetoclax with the DNA alkylator thiotepa (Thio) in AML cells. Cleavage of Caspase 3, PARP1 and HSP90, as well as increased Annexin V positivity, suggest potent activation of apoptosis by this two-drug combination; increased levels of γ-H2AX, P-CHK1 (S317), P-CHK2 (S19) and P-SMC1 (S957) indicate an enhanced DNA damage response. Likewise, the increased level of P-SAPK/JNK (T183/Y185) and decreased P-PI3Kp85 (Y458) suggest enhanced activation of stress signaling pathways. These molecular readouts were synergistically enhanced when ABT199/venetoclax and Thio were combined with fludarabine, cladribine and busulfan. The five-drug combination decreased the levels of BCL-2, BCL-xL and MCL-1, suggesting its potential clinical relevance in overcoming ABT199/venetoclax resistance. Moreover, this combination is active against P53-negative and FLT3-ITD-positive cell lines. Enhanced activation of apoptosis was observed in leukemia patient-derived cell samples exposed to the five-drug combination, suggesting a clinical relevance. The results provide a rationale for clinical trials using these two- and five-drug combinations as part of a conditioning regimen for AML patients undergoing HSCT.

Disruption of DLL4/NOTCH1 Causes Dysregulated PPARγ/AKT Signaling in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive cardiopulmonary disease characterized by vascular remodeling of small pulmonary arteries. Endothelial dysfunction in advanced PAH is associated with proliferation, apoptosis resistance, and endothelial to mesenchymal transition (EndoMT) due to aberrant signaling. DLL4, a cell membrane associated NOTCH ligand, activates NOTCH1 signaling and plays a pivotal role maintaining vascular integrity. Inhibition of DLL4 has been associated with the development of pulmonary hypertension, but the mechanism is incompletely understood. Here we report that BMPR2 silencing in PAECs activated AKT and decreased DLL4 expression. DLL4 loss was also seen in lungs of patients with IPAH and HPAH. Over-expression of DLL4 in PAECs induced BMPR2 promoter activity and exogenous DLL4 increased BMPR2 mRNA through NOTCH1 activation. Furthermore, DLL4/NOTCH1 signaling blocked AKT activation, decreased proliferation and reversed EndoMT in BMPR2-silenced PAECs and ECs from IPAH patients. PPARγ, suppressed by BMPR2 loss, was induced and activated by DLL4/NOTCH1 signaling in both BMPR2-silenced and IPAH PAECs, reversing aberrant phenotypic changes, in part through AKT inhibition. Finally, leniolisib, a well-tolerated oral PI3Kδ/AKT inhibitor, decreased cell proliferation, induced apoptosis and reversed markers of EndoMT in BMPR2-silenced PAECs. Restoring DLL4/NOTCH1/PPARγ signaling and/or suppressing AKT activation may be beneficial in preventing or reversing the pathologic vascular remodeling of PAH.

Genetic, Epigenetic and Transcriptome Alterations in Liposarcoma for Target Therapy Selection

Liposarcoma (LPS) is one of the most common adult soft-tissue sarcomas (STS), characterized by a high diversity of histopathological features as well as to a lesser extent by a spectrum of molecular abnormalities. Current targeted therapies for STS do not include a wide range of drugs and surgical resection is the mainstay of treatment for localized disease in all subtypes, while many LPS patients initially present with or ultimately progress to advanced disease that is either unresectable, metastatic or both. The understanding of the molecular characteristics of liposarcoma subtypes is becoming an important option for the detection of new potential targets and development novel, biology-driven therapies for this disease. Innovative therapies have been introduced and they are currently part of preclinical and clinical studies. In this review, we provide an analysis of the molecular genetics of liposarcoma followed by a discussion of the specific epigenetic changes in these malignancies. Then, we summarize the peculiarities of the key signaling cascades involved in the pathogenesis of the disease and possible novel therapeutic approaches based on a better understanding of subtype-specific disease biology. Although heterogeneity in liposarcoma genetics and phenotype as well as the associated development of resistance to therapy make difficult the introduction of novel therapeutic targets into the clinic, recently a number of targeted therapy drugs were proposed for LPS treatment. The most promising results were shown for CDK4/6 and MDM2 inhibitors as well as for the multi-kinase inhibitors anlotinib and sunitinib.

Tetrahydroalstonine possesses protective potentials on palmitic acid stimulated SK-N-MC cells by suppression of Aβ1-42 and tau through regulation of PI3K/Akt signaling pathway

Alzheimer's disease (AD) is the most common neurodegenerative disease. The morbidity of Alzheimer's disease is currently on the rise worldwide, but no effective treatment is available. Cornus officinalis is an herb and edible plant used in traditional Chinese medicine, whose extract has neuroprotective properties. In this investigation, we endeavored to refine a systems pharmacology strategy combining bioinformatics analysis, drug prediction, network pharmacology, and molecular docking to screen tetrahydroalstonine (THA) from Cornus officinalis as a therapeutic component for AD. Subsequent in vitro experiments were validated using MTT assay, Annexin V-PI flow cytometry, Western blotting, and immunofluorescence analysis. In Palmitate acid-induced SK-N-MC cells, THA restored the impaired PI3K/AKT signaling pathway, regulated insulin resistance, and attenuated BACE1 and GSK3β activity. In addition, THA significantly reduced cell apoptosis rate, down-regulated relative levels of p-JNK/JNK, Bax/Bcl-2, cytochrome C, active caspase-3 and caspase-3, and attenuated Palmitate acid-induced Aβ1-42 and Tau generation. THA may regulate the phenotype of AD and reduce cell apoptosis by modulating the PI3K/AKT signaling pathway. This systematic analysis provides new ramifications concerning the therapeutic utility of tetrahydroalstonine for AD.

Acryl-3,5-bis(2,4-difluorobenzylidene)-4-piperidone targeting cellular JUN proto-oncogene, AP-1 transcription factor subunit inhibits head and neck squamous cell carcinoma progression

Aim

Head and neck squamous cell carcinoma (HNSCC) is the seventh most common cancer worldwide with a survival rate below fifty percent. Addressing meager therapeutic options, a series of small molecule inhibitors were screened for antitumor efficacy. The most potent analog, acryl-3,5-bis(2,4-difluorobenzylidene)-4-piperidone (DiFiD; A-DiFiD), demonstrated strong cellular JUN proto-oncogene, activator protein 1 (AP-1) transcription factor subunit (JUN, c-Jun) antagonism. c-Jun, an oncogenic transcription factor, promotes cancer progression, invasion, and adhesion; high (JUN) mRNA expression correlates with poorer HNSCC survival.

Methods

Four new small molecules were generated for cytotoxicity screening in HNSCC cell lines. A-DiFiD-treated HNSCC cells were assessed for cytotoxicity, colony formation, invasion, migration, and adhesion. Dot blot array was used to identify targets. Phospho-c-Jun (p-c-Jun) expression was analyzed using immunoblotting. The Cancer Genome Atlas (TCGA) head and neck cancer datasets were utilized to determine overall patient survival. The Clinical Proteomic Tumor Analysis Consortium (CPTAC) datasets interfaced with University of Alabama at Birmingham Cancer Data Analysis Portal (UALCAN) were analyzed to determine protein levels of c-Jun in HNSCC patients and correlate levels with patient.

Results

Of the small molecules tested, A-DiFiD was the most potent in HNSCC lines, while demonstrating low half-maximal drug inhibitory concentration (IC50) in non-malignant Het-1A cells. Additionally, A-DiFiD abrogated cell invasion, migration, and colony formation. Phospho-kinase in vitro array demonstrated A-DiFiD reduced p-c-Jun. Likewise, a time dependent reduction in p-c-Jun was observed starting at 3 min post A-DiFiD treatment. TCGA Firehose Legacy vs. recurrent and metastatic head and neck cancer reveal a nearly 3% DNA amplification in recurrent/metastatic tumor compared to below 1% in primary tumors that had no lymph node metastasis. CPTAC analysis show higher tumor c-Jun levels compared to normal. Patients with high JUN expression had significantly reduced 3-year survival.

Conclusions

A-DiFiD targets c-Jun, a clinical HNSCC driver, with potent anti-tumor effects.

Pharmacological Akt and JNK Kinase Inhibitors 10-DEBC and SP600125 Potentiate Anti-Glioblastoma Effect of Menadione and Ascorbic Acid Combination in Human U251 Glioblastoma Cells

Glioblastoma multiforme (GBM) is the most lethal primary brain tumor in adults, characterized by a highly invasive nature and therapy resistance. Combination of menadione and ascorbic acid (AA+MD) exerts strong ROS-mediated anti-GBM activity in vitro. The objective of this study was to improve AA+MD anti-GBM potential by modulating the activity of Akt and c-Jun N-terminal kinase (JNK), molecules with an important role in GBM development. The effects of Akt and JNK modulation on AA+MD toxicity in U251 human glioblastoma cells were assessed by cell viability assays, flow cytometry, RNA interference and plasmid overexpression, and immunoblot analysis. The AA+MD induced severe oxidative stress, an early increase in Akt phosphorylation followed by its strong inhibition, persistent JNK activation, and U251 cell death. Small molecule Akt kinase inhibitor 10-DEBC enhanced, while pharmacological and genetic Akt activation decreased, AA+MD-induced toxicity. The U251 cell death potentiation by 10-DEBC correlated with an increase in the combination-induced autophagic flux and was abolished by genetic autophagy silencing. Additionally, pharmacological JNK inhibitor SP600125 augmented combination toxicity toward U251 cells, an effect linked with increased ROS accumulation. These results indicate that small Akt and JNK kinase inhibitors significantly enhance AA+MD anti-GBM effects by autophagy potentiation and amplifying deleterious ROS levels.

Diosgenin restores memory function via SPARC-driven axonal growth from the hippocampus to the PFC in Alzheimer's disease model mice

Central nervous system axons have minimal capacity to regenerate in adult brains, hindering memory recovery in Alzheimer's disease (AD). Although recent studies have shown that damaged axons sprouted in adult and AD mouse brains, long-distance axonal re-innervation to their targets has not been achieved. We selectively visualized axon-growing neurons in the neural circuit for memory formation, from the hippocampus to the prefrontal cortex, and showed that damaged axons successfully extended to their native projecting area in mouse models of AD (5XFAD) by administration of an axonal regenerative agent, diosgenin. In vivo transcriptome analysis detected the expression profile of axon-growing neurons directly isolated from the hippocampus of 5XFAD mice. Secreted protein acidic and rich in cysteine (SPARC) was the most expressed gene in axon-growing neurons. Neuron-specific overexpression of SPARC via adeno-associated virus serotype 9 delivery in the hippocampus recovered memory deficits and axonal projection to the prefrontal cortex in 5XFAD mice. DREADDs (Designer receptors exclusively activated by designer drugs) analyses revealed that SPARC overexpression-induced axonal growth in the 5XFAD mouse brain directly contributes to memory recovery. Elevated levels of SPARC on axonal membranes interact with extracellular rail-like collagen type I to promote axonal remodeling along their original tracings in primary cultured hippocampal neurons. These findings suggest that SPARC-driven axonal growth in the brain may be a promising therapeutic strategy for AD and other neurodegenerative diseases.

Targeting fibrotic signaling pathways by EGCG as a therapeutic strategy for uterine fibroids

Fibrosis is characterized by excessive accumulation of extracellular matrix, which is a key feature of uterine fibroids. Our prior research supports the tenet that inhibition of fibrotic processes may restrict fibroid growth. Epigallocatechin gallate (EGCG), a green tea compound with powerful antioxidant properties, is an investigational drug for uterine fibroids. An early phase clinical trial showed that EGCG was effective in reducing fibroid size and its associated symptoms; however, its mechanism of action(s) has not been completely elucidated. Here, we probed effects of EGCG on key signaling pathways involved in fibroid cell fibrosis. Viability of myometrial and fibroid cells was not greatly affected by EGCG treatment (1-200 µM). Cyclin D1, a protein involved in cell cycle progression, was increased in fibroid cells and was significantly reduced by EGCG. EGCG treatment significantly reduced mRNA or protein levels of key fibrotic proteins, including fibronectin (FN1), collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1), connective tissue growth factor (CTGF), and actin alpha 2, smooth muscle (ACTA2) in fibroid cells, suggesting antifibrotic effects. EGCG treatment altered the activation of YAP, β-catenin, JNK and AKT, but not Smad 2/3 signaling pathways involved in mediating fibrotic process. Finally, we conducted a comparative study to evaluate the ability of EGCG to regulate fibrosis with synthetic inhibitors. We observed that EGCG displayed greater efficacy than ICG-001 (β-catenin), SP600125 (JNK) and MK-2206 (AKT) inhibitors, and its effects were equivalent to verteporfin (YAP) or SB525334 (Smad) for regulating expression of key fibrotic mediators. These data indicate that EGCG exhibits anti-fibrotic effects in fibroid cells. These results provide insight into mechanisms behind the observed clinical efficacy of EGCG against uterine fibroids.

N-(2-ozoazepan-3-yl)-pyrrolidine-2-carboxamide, a novel Octopus vulgaris ink-derived metabolite, exhibits a pro-apoptotic effect on A549 cancer cell line and inhibits pro-inflammatory markers

This research aimed to chemically synthesize and evaluate the antiproliferative and anti-inflammatory potential of ozopromide (OPC), a novel compound recently isolated from O. vulgaris ink. After chemical synthesis, OPC structural characterization was confirmed by COSY2D, FTIR, and C-/H-NMR. OPC inhibited the growth of human breast (MDA-MB-231), prostate (22Rv1), cervix (HeLa), and lung (A549) cancerous cells, being the highest effect on the latter (IC₅₀: 53.70 μM). As confirmed by flow cytometry, OPC induced typical apoptosis-derived morphological features on A549 cells, mostly at early and late apoptosis stages. OPC generated a dose-dependent effect inhibiting IL-6 and IL-8 on LPS-stimulated peripheral mononuclear cells (PBMCs). A major affinity of OPC to Akt-1 and Bcl-2 proteins in silico agreed with the observed pro-apoptotic mechanisms. Results suggested that OPC has the potential to alleviate inflammation and be further studied for anticancer activity. Marine-derived food products such as ink contains bioactive metabolites exhibiting potential health benefits.

Natural compounds regulate the PI3K/Akt/GSK3β pathway in myocardial ischemia-reperfusion injury

The PI3K/Akt/GSK3β pathway is crucial in regulating cardiomyocyte growth and survival. It has been shown that activation of this pathway alleviates the negative impact of ischemia-reperfusion. Glycogen synthase kinase-3 (GSK3β) induces apoptosis through stimulation of transcription factors, and its phosphorylation has been suggested as a new therapeutic target for myocardial ischemia-reperfusion injury (MIRI). GSK3β regulatory role is mediated by the reperfusion injury salvage kinase (RISK) pathway, and its inhibition by Akt activation blocks mitochondrial permeability transition pore (mPTP) opening and enhances myocardial survival. The present article discusses the involvement of the PI3K/Akt/GSK3β pathway in cardioprotective effects of natural products against MIRI.Abbreviations: Akt: protein kinase B; AMPK: AMP-activated protein kinase; ATP: adenosine triphosphate; Bad: bcl2-associated agonist of cell death; Bax: bcl2-associated x protein; Bcl-2: B-cell lymphoma 2; CK-MB: Creatine kinase-MB; CRP: C-reactive-protein; cTnI: cardiac troponin I; EGCG: Epigallocatechin-3-gallate; Enos: endothelial nitric oxide synthase; ER: endoplasmic reticulum; ERK ½: extracellular signal‑regulated protein kinase ½; GSK3β: glycogen synthase kinase-3; GSRd: Ginsenoside Rd; GSH: glutathione; GSSG: glutathione disulfide; HO-1: heme oxygenase-1; HR: hypoxia/reoxygenation; HSYA: Hydroxysafflor Yellow A; ICAM-1: Intercellular Adhesion Molecule 1; IKK-b: IκB kinase; IL: interleukin; IPoC: Ischemic postconditioning; IRI: ischemia-reperfusion injury; JNK: c-Jun N-terminal kinase; Keap1: kelch-like ECH-associated protein- 1; LDH: lactate dehydrogenase; LVEDP: left ventricular end diastolic pressure; LVP: left ventricle pressure; LVSP: left ventricular systolic pressure; MAPK: mitogen-activated protein kinase; MDA: malondialdehyde; MIRI: myocardial ischemia-reperfusion injury; MnSOD: manganese superoxide dismutase; mPTP: mitochondrial permeability transition pore; mtHKII: mitochondria-bound hexokinase II; Nrf-1: nuclear respiratory factor 1; Nrf2: nuclear factor erythroid 2-related factor; NO: nitric oxide; PGC-1α: peroxisome proliferator‑activated receptor γ coactivator‑1α; PI3K: phosphoinositide 3-kinases; RISK: reperfusion injury salvage kinase; ROS: reactive oxygen species; RSV: Resveratrol; SOD: superoxide dismutase; TFAM: transcription factor A mitochondrial; TNF-α: tumor necrosis factor-alpha; VEGF-B: vascular endothelial growth factor B.

In Vitro Anticancer Activity of Novel Ciprofloxacin Mannich Base in Lung Adenocarcinoma and High-Grade Serous Ovarian Cancer Cell Lines via Attenuating MAPK Signaling Pathway

Novel drugs are desperately needed in order to combat a significant challenge due to chemo-therapeutic resistance and bad prognosis. This research aimed to assess the anticancer activity of a newly synthesized ciprofloxacin Mannich base (CMB) on ovarian cancer (OVCAR-3) and lung cancer (A-549) cell lines and to investigate probable involved molecular mechanisms. The cytotoxic and pro-apoptotic impact of CMB on both cell lines was investigated using MTT assay, Annexin V assay, and cell cycle analysis, as well as caspase-3 activation. Western blotting was carried out to evaluate downstream targets of the MAPK pathway, while qRT PCR was used to evaluate the gene expression pattern of the p53/Bax/Bcl2 pathway. CMB treatment showed significantly reduced cell proliferation in both OVCAR-3 and A-549 cells with half maximum inhibitory concentration (IC₅₀) = 11.60 and 16.22 µg/mL, respectively. CMB also induced apoptosis, S phase cell cycle arrest, and up-regulated expression of p53, p21, and Bax while down-regulated Bcl2 expression. CMB also halted cell proliferation by deactivating the MAPK pathway. In conclusion, CMB may be regarded as a potential antiproliferative agent for lung and ovarian cancers due to anti-proliferative and pro-apoptotic actions via inhibition of the MAPK pathway and p53/Bax/Bcl2.

Alpha-B-Crystallin overexpression is sufficient to promote tumorigenesis and metastasis in mice

BACKGROUND

αB-Crystallin is a heat shock chaperone protein which binds to misfolded proteins to prevent their aggregation. It is overexpressed in a wide-variety of cancers. Previous studies using human cancer cell lines and human xenograft models have suggested potential tumor promoter (oncogene) roles for αB-Crystallin in a wide-spectrum of cancers.

METHODS

To determine the causal relationship between CRYAB overexpression and cancer, we generated a Cryab overexpression knock-in mouse model and monitor them for development of spontaneous and carcinogen (DMBA)-induced tumorigenesis. In order to investigate the mechanism of malignancies observed in this model multiple techniques were used such as immunohistochemical characterizations of tumors, bioinformatics analysis of publically available human tumor datasets, and generation of mouse embryonic fibroblasts (MEFs) for in vitro assays (clonogenic survival and migration assays and proteome analysis by mass-spectrometry).

RESULTS

This model revealed that constitutive overexpression of Cryab results in the formation of a variety of lethal spontaneous primary and metastatic tumors in mice. In vivo, the overexpression of Cryab correlated with the upregulation of epithelial-to-mesenchymal (EMT) markers, angiogenesis and some oncogenic proteins including Basigin. In vitro, using E1A/Ras transformed MEFs, we observed that the overexpression of Cryab led to the promotion of cell survival via upregulation of Akt signaling and downregulation of pro-apoptotic pathway mediator JNK, with subsequent attenuation of apoptosis as assessed by cleaved caspase-3 and Annexin V staining.

CONCLUSIONS

Overall, through the generation and characterization of Cryab overexpression model, we provide evidence supporting the role of αB-Crystallin as an oncogene, where its upregulation is sufficient to induce tumors, promote cell survival and inhibit apoptosis.

Pentraxin 3 regulates tyrosine kinase inhibitor-associated cardiomyocyte contraction and mitochondrial dysfunction via ERK/JNK signalling pathways

BACKGROUND

Hepatocellular carcinoma (HCC) patients suffer varying degrees of heart dysfunction after tyrosine kinase inhibitor (TKI) treatment. Interestingly, HCC patients often have higher levels of pentraxin 3 (PTX3), and PTX3 inhibition was found to improve left ventricular dysfunction in animal models.

OBJECTIVES

We sought to assess the therapeutic potential of PTX3 inhibition on TKI-associated cardiotoxicity.

METHODS

We used a human embryonic stem cell line, RUES2, to generate cardiomyocyte cultures (RUES2-CM) for functional testing. We also assessed heart function and PTX3 expression levels in 16 HCC patients who received TKI treatment, 3 HCC patients who did not receive TKIs, and 7 healthy volunteers.

RESULTS

Significantly higher PTX3 expression was noted in HCC patients with TKI treatment versus those without, and 38% of male and 33% of female patients had QTc prolongation after TKI treatment. Treatment of cardiomyocyte cultures with sorafenib also increased PTX3 expression and induced cytoskeletal remodelling, contraction reduction, sodium current inhibition, and mitochondrial respiratory dysfunction. PTX3 colocalised with CD44 in cardiomyocytes, and cardiomyocyte contraction, mitochondrial respiratory function, and regular cytoskeletal and apoptotic protein expression were restored with PTX3 inhibition. CD44 knockdown confirmed PTX3/CD44 signalling. These results suggest a possible mechanism in which sorafenib treatment increases PTX3 expression, thereby resulting in reduced extracellular signal-regulated kinase (ERK) 1/2 expression that affects cardiomyocyte contraction, while also activating c-Jun N-terminal kinase (JNK) downstream pathways to disrupt mitochondrial respiration and trigger apoptosis.

CONCLUSIONS

TKI-induced cardiotoxicity may be partly mediated by the upregulation of PTX3, and thus PTX3 inhibition has potential as a therapeutic strategy.

A PRMT5 inhibitor protects against noise-induced hearing loss by alleviating ROS accumulation

The aim of this study was to investigate the effect of LLY-283, a selective inhibitor of protein arginine methyltransferase 5 (PRMT5), on a noise-induced hearing loss (NIHL) mouse model and to identify a potential target for a therapeutic intervention against NIHL. Eight-week-old male C57BL/6 mice were used. The auditory brainstem response was measured 2 days after noise exposure. The apoptosis of hair cells (HCs) was detected by caspase-3/7 staining, whereas the accumulation of reactive oxygen species (ROS) was measured by 4-HNE staining. We demonstrated that the death of HCs and loss of cochlear synaptic ribbons induced by noise exposure could be significantly reduced by the presence of LLY-283. LLY-283 pretreatment before noise exposure notably decreased 4-HNE and caspase-3/7 levels in the cochlear HCs. We also noticed that the number of spiral ganglion neurons (SGNs) was notably increased after LLY-283 pretreatment. Furthermore, we showed that LLY-283 could increase the expression level of p-AKT in the SGNs. The underlying mechanism involves alleviation of ROS accumulation and activation of the PI3K/AKT pathway, indicating that LLY-283 might be a potential candidate for therapeutic intervention against NIHL.

Using Network Pharmacology and Molecular Docking Technology to Explore the Mechanism of Modified Pulsatilla Decoction in the Treatment of Ulcerative Colitis

Objective: Using network pharmacology and molecular docking technology, our aim was to clarify the biological activity, key targets, and potential pharmacological mechanisms of modified Pulsatilla decoction (MPD) in the treatment of ulcerative colitis (UC). Materials and Methods: The main active ingredients of MPD were screened using the traditional Chinese medicine systems pharmacology platform. UC targets were obtained from the GeneCard, OMIM, DisGeNET, PharmGkb, and DrugBank databases. The common genes of MPD in the treatment of UC were identified by Venn diagram. The visual interactive network diagram of “active ingredient-target-disease” was constructed using the software Cytoscape. We used the STRING database to construct a protein–protein interaction network and analyze the correlation in protein interaction. We conducted gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis for common genes using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) database and R software. Subsequently, the molecular docking verification of ingredients and targets was conducted through Discovery Studio. Last, in vivo experiments were conducted to further verify the findings. Results: A total of 51 active ingredients were screened, involving 141 common genes. The top 5 ingredients in MPD were quercetin, β-sitosterol, luteolin, kaempferol, and stigmasterol. Pathways involved in the treatment of UC include the advanced glycation end products-receptor for advanced glycation end products (AGE-RAGE) signaling pathway, the interleukin-17 (IL-17) signaling pathway, the tumor necrosis factor (TNF) signaling pathway, viral infection-related signaling pathways, and some cancer pathways. Molecular docking showed that the important ingredients of MPD were well docked with mitogen-activated protein kinase 1 (MAPK1), mitogen-activated protein kinase 8 (MAPK8), RAC-alpha serine (AKT1), vascular endothelial growth factor-A (VEGFA), transcription factor AP-1 (JUN), and interleukin-6 (IL-6). Animal experiments showed that MPD could ameliorate the injury and colitis in dextran sulfate sodium (DSS)-induced colitic rats. MPD inhibited the expression of p-p38A and p-MLC in UC rats. Conclusions: MPD has the characteristics of a multisystem, multi-ingredient, and multitarget in the treatment of UC. The possible mechanisms include inhibition of inflammation, apoptosis, oxidation, and tumor gene transcription. MPD may have a protective effect in the treatment of UC.

β-Arrestin2 Is Critically Involved in the Differential Regulation of Phosphosignaling Pathways by Thyrotropin-Releasing Hormone and Taltirelin

In recent years, thyrotropin-releasing hormone (TRH) and its analogs, including taltirelin (TAL), have demonstrated a range of effects on the central nervous system that represent potential therapeutic agents for the treatment of various neurological disorders, including neurodegenerative diseases. However, the molecular mechanisms of their actions remain poorly understood. In this study, we investigated phosphosignaling dynamics in pituitary GH1 cells affected by TRH and TAL and the putative role of β-arrestin2 in mediating these effects. Our results revealed widespread alterations in many phosphosignaling pathways involving signal transduction via small GTPases, MAP kinases, Ser/Thr- and Tyr-protein kinases, Wnt/β-catenin, and members of the Hippo pathway. The differential TRH- or TAL-induced phosphorylation of numerous proteins suggests that these ligands exhibit some degree of biased agonism at the TRH receptor. The different phosphorylation patterns induced by TRH or TAL in β-arrestin2-deficient cells suggest that the β-arrestin2 scaffold is a key factor determining phosphorylation events after TRH receptor activation. Our results suggest that compounds that modulate kinase and phosphatase activity can be considered as additional adjuvants to enhance the potential therapeutic value of TRH or TAL.

Revisited role of TRAF2 and TRAF2 C-terminal domain in endoplasmic reticulum stress-induced autophagy in HAP1 leukemia cells

The scaffold protein Tumor Necrosis Factor Receptor-Associated Factor 2 (TRAF2) has been reported to play a key role in the endoplasmic reticulum (ER) stress-induced activation of c-Jun N-terminal Kinase (JNK) and hence autophagy. Autophagy is a highly conserved catabolic process, whose dysregulation is involved in the pathogenesis of various human diseases, including cancer. We investigated the involvement of TRAF2 in autophagy regulation in the human leukemic HAP1 cell line, under both basal and ER stress conditions. In TRAF2-knockout HAP1 cell line (KO), the basal autophagic flux was higher than in the parental cell line (WT). Moreover, tunicamycin-induced ER stress stimulated JNK activation and autophagy both in WT and KO HAP1. On the other hand, re-expression of a TRAF2 C-terminal fragment (residues ,310-501), in a TRAF2-KO cellular background, rendered HAP1 cells unable to activate both JNK and autophagy upon ER stress induction. Of note, this apparent dominant negative effect of the C-terminal fragment was observed even in the absence of the endogenous, full-length TRAF2 molecule. Furthermore, the expression of the C-terminal fragment resulted in both protein kinase B (AKT) pathway activation and increased resistance to the toxic effects induced by prolonged ER stress conditions. These findings indicate that TRAF2 is dispensable for the activation of both JNK and autophagy in HAP1 cells, while the TRAF2 C-terminal domain may play an autonomous role in regulating the cellular response to ER stress.

Morpholino-driven blockade of Dkk-1 in osteosarcoma inhibits bone damage and tumour expansion by multiple mechanisms

Background

Osteosarcoma (OS) is the most common primary bone malignancy. Chemotherapy plays an essential role in OS treatment, potentially doubling 5-year event-free survival if tumour necrosis can be stimulated. The canonical Wnt inhibitor Dickkopf-1 (Dkk-1) enhances OS survival in part through upregulation of aldehyde-dehydrogenase-1A1 which neutralises reactive oxygen species originating from nutritional stress and chemotherapeutic challenge.

Methods

A vivo morpholino (DkkMo) was employed to block the expression of Dkk-1 in OS cells. Cell mitosis, gene expression and bone destruction were measured in vitro and in vivo in the presence and absence of doxorubicin (DRB).

Results

DkkMo reduced the expression of Dkk-1 and Aldh1a1, reduced expansion of OS tumours, preserved bone volume and architecture and stimulated tumour necrosis. This was observed in the presence or absence of DRB.

Conclusion

These results indicate that administration of DkkMo with or without chemotherapeutics can substantially improve OS outcome with respect to tumour expansion and osteolytic corruption of bone in experimental OS model.

Metadherin (AEG-1/MTDH/LYRIC) expression: Significance in malignancy and crucial role in colorectal cancer

Metadherin (AEG-1/MTDH/LYRIC) is a 582-amino acid transmembrane protein, encoded by a gene located at chromosome 8q22, and distributed throughout the cytoplasm, peri-nuclear region, nucleus, and nucleolus as well as the endoplasmic reticulum (ER). It contains several structural and interacting domains through which it interacts with transcription factors such as nuclear factor-κB (NF-κB), promyelocytic leukemia zinc finger (PLZF), staphylococcal nuclease domain containing 1 (SND1) and lung homing domain (LHD). It is regulated by miRNAs and mediates its oncogenic function via activation of cell proliferation, survival, migration and metastasis, as well as, angiogenesis and chemoresistance via phosphatidylinositol-3-kinase/AKT (PI3K/AKT), NF-κB, mitogen-activated protein kinase (MAPK) and Wnt signaling pathways. In this chapter, metadherin is reviewed highlighting its role in mediating growth, metastasis and chemoresistance in colorectal cancer (CRC). Metadherin, as well as its variants, and antibodies are associated with CRC progression, poorer prognosis, decreased survival and advanced clinico-pathology. The potential of AEG-1/MTDH/LYRIC as a diagnostic and prognostic marker as well as a therapeutic target in CRC is explored.

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

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

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

Smart Nanoparticles as Advanced Anti-Akt Kinase Delivery Systems for Pancreatic Cancer Therapy

Pancreatic cancer is one of the deadliest cancers partly due to late diagnosis, poor drug delivery to the target site, and acquired resistance to therapy. Therefore, more effective therapies are urgently needed to improve the outcome of patients. In this work, we have tested self-assembling genetically engineered polymeric nanoparticles formed by elastin-like recombinamers (ELRs), carrying a small peptide inhibitor of the protein kinase Akt, in both PANC-1 and patient-derived pancreatic cancer cells (PDX models). Nanoparticle cell uptake was measured by flow cytometry, and subcellular localization was determined by confocal microscopy, which showed a lysosomal localization of these nanoparticles. Furthermore, metabolic activity and cell viability were significantly reduced after incubation with nanoparticles carrying the Akt inhibitor in a time- and dose-dependent fashion. Self-assembling 73 ± 3.2 nm size nanoparticles inhibited phosphorylation and consequent activation of Akt protein, blocked the NF-κB signaling pathway, and triggered caspase 3-mediated apoptosis. Furthermore, in vivo assays showed that ELR-based nanoparticles were suitable devices for drug delivery purposes with long circulating time and minimum toxicity. Hence, the use of these smart nanoparticles could lead to the development of more effective treatment options for pancreatic cancer based on the inhibition of Akt.

Claudin 14/15 play important roles in early wallerian degeneration after rat sciatic nerve injury

PURPOSE

Wallerian degeneration (WD) is an antegrade degenerative process distal to peripheral nerve injury. Numerous genes are differentially regulated in response to the process. However, the underlying mechanism is unclear, especially the early response. We aimed at investigating the effects of sciatic nerve injury on WD via CLDN 14/15 interactions in vivo and in vitro.

METHODS

Using the methods of molecular biology and bioinformatics analysis, we investigated the molecular mechanism by which claudin 14/15 participate in WD. Our previous study showed that claudins 14 and 15 trigger the early signal flow and pathway in damaged sciatic nerves. Here, we report the effects of the interaction between claudin 14 and claudin 15 on nerve degeneration and regeneration during early WD.

RESULTS

It was found that claudin 14/15 were upregulated in the sciatic nerve in WD. Claudin 14/15 promoted Schwann cell proliferation, migration and anti-apoptosis in vitro. PKCα, NT3, NF2, and bFGF were significantly upregulated in transfected Schwann cells. Moreover, the expression levels of the β-catenin, p-AKT/AKT, p-c-jun/c-jun, and p-ERK/ERK signaling pathways were also significantly altered.

CONCLUSION

Claudin 14/15 affect Schwann cell proliferation, migration, and anti-apoptosis via the β-catenin, p-AKT/AKT, p-c-jun/c-jun, and p-ERK/ERK pathways in vitro and in vivo. The results of this study may help elucidate the molecular mechanisms of the tight junction signaling pathway underlying peripheral nerve degeneration.

De Novo Hepatocellular Carcinoma in Hepatitis C-Related Cirrhosis: Are Advanced Glycation End Products a Key Driver?

Background and Purpose

The advanced glycation end products (AGEs) have been implicated in different diseases’ pathogenesis, but their role in hepatocellular carcinoma (HCC) is still a matter of debate. This study aims to investigate the association of AGEs with HCC development in patients with hepatitis C-related cirrhosis.

Methods

Only 153 of the 181 non-diabetic patients with cirrhosis were consecutively involved in this pilot cohort prospective study, along with 34 healthy control participants. Demographic characteristics, biochemical parameters, clinical data, and AGEs levels in all subjects at the starting point and every year after that for two years were assessed. Multivariable Cox regression analysis was used to settle variables that could predict HCC development within this period.

Results

HCC developed in 13 (8.5%) patients. Univariate Cox regression analysis reported that body mass index (P=0.013), homeostatic model assessment-insulin resistance (P=0.006), alpha-fetoprotein (P <0.001), and AGEs levels (P <0.001) were related to HCC development. After adjusting multiple confounders, the multivariable Cox regression model has revealed that AFP and AGEs were the powerful parameters related to the HCC occurrence (all P<0.05). AGEs at a cutoff value of more than 79.6 ng/ml had 100% sensitivity, 96.4% specificity, and 0.999 area under the curve (all P<0.001), using the receiver operating characteristic curve, for prediction of HCC development.

Conclusion

This work suggests that AGEs are associated with an increased incidence of HCC, particularly in cirrhosis, which is encouraging in decreasing the risk of HCC in these patients.

The Role of Formyl Peptide Receptors in Neurological Diseases via Regulating Inflammation

Formyl peptide receptors (FPRs) are a group of G protein-coupled cell surface receptors that play important roles in host defense and inflammation. Owing to the ubiquitous expression of FPRs throughout different cell types and since they interact with structurally diverse chemotactic agonists, they have a dual function in inflammatory processes, depending on binding with different ligands so that accelerate or inhibit key intracellular kinase-based regulatory pathways. Neuroinflammation is closely associated with the pathogenesis of neurodegenerative diseases, neurogenic tumors and cerebrovascular diseases. From recent studies, it is clear that FPRs are important biomarkers for neurological diseases as they regulate inflammatory responses by monitoring glial activation, accelerating neural differentiation, regulating angiogenesis, and controlling blood brain barrier (BBB) permeability, thereby affecting neurological disease progression. Given the complex mechanisms of neurological diseases and the difficulty of healing, we are eager to find new and effective therapeutic targets. Here, we review recent research about various mechanisms of the effects generated after FPR binding to different ligands, role of FPRs in neuroinflammation as well as the development and prognosis of neurological diseases. We summarize that the FPR family has dual inflammatory functional properties in central nervous system. Emphasizing that FPR2 acts as a key molecule that mediates the active resolution of inflammation, which binds with corresponding receptors to reduce the expression and activation of pro-inflammatory composition, govern the transport of immune cells to inflammatory tissues, and restore the integrity of the BBB. Concurrently, FPR1 is essentially related to angiogenesis, cell proliferation and neurogenesis. Thus, treatment with FPRs-modulation may be effective for neurological diseases.

A dual-targeted molecular therapy of PP242 and cetuximab plays an anti-tumor effect through EGFR downstream signaling pathways in colorectal cancer

Background

Epidermal growth factor receptor (EGFR) and its downstream Ras-mitogen-activated protein kinase kinase (MAPKK, MEK)-extracellular regulated protein kinase (ERK) signaling pathway and phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling pathway play important roles in the pathogenesis of colorectal cancer (CRC). The combination therapy of anti-EGFR and anti-mTOR needs to be explored.

Methods

Here we combined the anti-EGFR monoclonal antibody cetuximab (CTX) with the mTOR inhibitor PP242 in CRC cell lines and mouse xenograft models and discussed the changes of EGFR downstream signaling pathways of CRC cell lines.

Results

In HT-29 cells and Caco-2 cells, combined application of CTX and PP242 significantly inhibited the proliferation of CRC cells in vivo and in vitro. In BRAF wild-type Caco-2 cells, combined application of CTX and PP242 inhibited the activation of the EGFR and its downstream signaling pathways.

Conclusions

Our research further demonstrates the effectiveness of the combined application of CTX and PP242 in inhibiting CRC cell lines from the perspective of cell proliferation, cell cycle, apoptosis, and mouse xenografts. We revealed that the combined application of CTX and PP242 can inhibit tumor growth and proliferation by inhibiting the phosphorylation of key molecules in EGFR downstream MEK-ERK and MEK 4/7 (MKK)-c-Jun N-terminal kinase (JNK) signaling pathways in BRAF wild-type CRC cells. In addition, we found that in BRAF mutant CRC cells, the monotherapy of PP242 resulted in negative feedback increased EGFR phosphorylation rates, accompanied by significant up-regulation of downstream MEK and ERK phosphorylation.

Identification of Molecules Responsible for Therapeutic Effects of Extracellular Vesicles Produced from iPSC-Derived MSCs on Sjo¨gren's Syndrome

Recent research indicated that extracellular vesicles (EVs) derived from mesenchymal stem/stromal cells (MSCs) are a promising alternative to MSCs for immunomodulatory therapy. However, the contents of MSC-EVs would change as their parent MSCs change, hence the therapeutic efficacy of MSC-derived EVs (MSC-EVs) would largely depend on donors, tissue sources and culture conditions of MSCs. To overcome limitations of tissue-derived MSCs, we previously used MSCs derived from human induced pluripotent stem cells (iMSCs) to produce EVs and demonstrated their therapeutic potential in a mouse model of secondary Sjo¨gren's Syndrome. Here, we further found that EVs from early-passage iMSCs had better immunomodulatory potency than EVs from late-passage iMSCs in TLR4-stimulated splenocytes and in a mouse model of primary Sjögren's syndrome. Comparative molecular profiling using proteomics and microRNA sequencing revealed distinctive molecular profiles of iMSC-EVs with or without immunomodulation capacity. Amongst them, manipulation of TGF-β1, miR-21 and miR-125b levels in iMSC-EVs significantly affected their immunosuppressive effects. These findings would help improve our understanding of the molecular mechanism underlying iMSC-EV-mediated immunomodulation and further provide strategies to improve regulatory function of EVs for the treatment of immune-mediated diseases.

Overexpressed HGF promotes metastasis of squamous cell carcinoma of the head and neck through the PI3K/Akt and JNK signaling pathways

Background: The role of HGF in squamous cell carcinoma of the head and neck (SCCHN) is not clear. Methods: Reverse transcription PCR, western blotting, gelatin zymography, immunohistochemistry, actin polymerization, chemotaxis and migration assays were used in the authors' study. Results: HGF expression level was upregulated in SCCHN cells, which was associated with clinical stage; tumor, node, metastasis classification; and lymphatic invasion. SCCHN cells with high Met expression were sensitive to cell invasion, which was blocked by inhibiting PI3K/Akt and JNK. HGF induced MMP9 expression and enhanced its activity. Akt induced the activation of JNK through the PI3K/Akt and JNK signaling pathways. Conclusion: HGF upregulates MMP9 through the activation of the PI3K/Akt and JNK signaling pathways in SCCHN cells.

Understanding Abnormal c-JNK/p38MAPK Signaling Overactivation Involved in the Progression of Multiple Sclerosis: Possible Therapeutic Targets and Impact on Neurodegenerative Diseases

Demyelination, immune dysregulation, and neuroinflammation are the most common triggers of motor neuron disorders such as multiple sclerosis (MS). MS is a chronic demyelinating neurodegenerative disease of the central nervous system caused by abnormal immune activation, which causes myelin sheath damage. Cell signal transduction pathways are required for a variety of physiological and pathological processes in the brain. When these signaling systems become overactive, they can lead to disease progression. In various physiological conditions, abnormal mitogen-activated protein kinase (MAPK) activation is associated with several physiological dysfunctions that cause neurodegeneration. Previous research indicates that c-JNK and p38MAPK signaling play critical roles in neuronal growth and differentiation. c-JNK/p38MAPK is a member of the MAPK family, which regulates metabolic pathways, cell proliferation, differentiation, and apoptosis that control certain neurological activities. During brain injuries, c-JNK/p38MAPK also affects neuronal elastic properties, nerve growth, and cognitive processing. This review systematically linked abnormal c-JNK/p38MAPK signaling activation to multiple neuropathological pathways in MS and related neurological dysfunctions. MS progression is linked to genetic defects, oligodendrocyte destruction, glial overactivation, and immune dysregulation. We concluded that inhibiting both the c-JNK/p38MAPK signaling pathways can promote neuroprotection and neurotrophic effects against the clinical-pathological presentation of MS and influence other neurological disorders. As a result, the potential benefits of c-JNK/p38MAPK downregulation for the development of disease-modifying treatment interventions in the future could include MS prevention and related neurocomplications.

Klotho Protein and Cardio-Vascular System

Klotho protein affects a number of metabolic pathways essential for pathogenesis of cardio-vascular diseases and their prevention. It inhibits lipid peroxidation and inflammation, as well as prevents endothelial injury and calcification of blood vessels. Klotho decreases rigidity of blood vessels and suppresses development of the heart fibrosis. Low level of its expression is associated with a number of diseases. Cardioprotective effect of klotho is based on its ability to interact with multiple receptors and ion channels. Being a pleiotropic protein, klotho could be a useful target for therapeutic intervention in the treatment of cardio-vascular diseases. In this review we present data on pharmaceuticals that stimulate klotho expression and suggest some promising research directions.

Downregulation of glob1 suppresses pathogenesis of human neuronal tauopathies in Drosophila by regulating tau phosphorylation and ROS generation

Human tauopathies represent a group of neurodegenerative disorders, characterized by abnormal hyperphosphorylation and aggregation of tau protein, which ultimately cause neurodegeneration. The aberrant tau hyperphosphorylation is mostly attributed to the kinases/phosphatases imbalance, which is majorly contributed by the generation of reactive oxygen species (ROS). Globin(s) represent a well-conserved group of proteins which are involved in O₂ management, regulation of cellular ROS in different cell types. Similarly, Drosophila globin1 (a homologue of human globin) with its known roles in oxygen management and development of nervous system exhibits striking similarities with the mammalian neuroglobin. Several recent evidences support the hypothesis that neuroglobins are associated with Alzheimer's disease pathogenesis. We herein noted that targeted expression of human-tau induces the cellular level of Glob1 protein in Drosophila tauopathy models. Subsequently, RNAi mediated restored level of Glob1 restricts the pathogenic effect of human-tau by minimizing its hyperphosphorylation via GSK-3β/p-Akt and p-JNK pathways. In addition, it also activates the Nrf2-keap1-ARE cascade to stabilize the tau-mediated increased level of ROS. These two parallel cellular events provide a significant rescue against human tau-mediated neurotoxicity in the fly models. For the first time we report a direct involvement of an oxygen sensing globin gene in tau etiology. In view of the fact that human genome encodes for the multiple Globin proteins including a nervous system specific neuroglobin; and therefore, our findings may pave the way to investigate if the conserved oxygen sensing globin gene(s) can be exploited in devising novel therapeutic strategies against tauopathies.

Anti-DLBCL efficacy of DCZ0825 in vitro and in vivo: involvement of the PI3K‒AKT‒mTOR/JNK pathway

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, characterized by high heterogeneity. The poor outcome of a portion of patients who suffer relapsing or resistant to conventional treatment impels the development of novel agents for DLBCL. DCZ0825 is a novel compound derived from pterostilbene and osalmide, whose antitumor activities have drawn our attention. In this study, we found that DCZ0825 exhibited high cytotoxicity toward DLBCL cell lines in a dose- and time-dependent manner, as revealed by cell counting kit-8 assay. Flow cytometry and western blot analysis results showed that DCZ0825 also promoted cell apoptosis via both extrinsic and intrinsic apoptosis pathways mediated by caspase. In addition, DCZ0825 induced cell cycle arrest in the G2/M phase by downregulating Cdc25C, CDK1, and Cyclin B1, thus interfering with cell proliferation. Further investigation showed the involvement of the phosphatidylinositol 3-kinase (PI3K)‒AKT‒mTOR/JNK pathway in the efficacy of DCZ0825 against DLBCL. Remarkably, DCZ0825 also exerted notable cytotoxic effects in vivo as well, with low toxicity to important internal organs such as the liver and kidney. Our results suggest that DCZ0825 may have the potential to become a novel anti-DLBCL agent or to replenish the conventional therapeutic scheme of DLBCL.

Phyllanthin inhibits MOLT-4 leukemic cancer cell growth and induces apoptosis through the inhibition of AKT and JNK signaling pathway

Among cancers, leukemia is a multistep progression that involves genetic modifications of normal hematopoietic progenitor cells to cancerous cells. In recent times, leukemia cases and their mortality rate have increased rapidly. Therefore, the immense need for a therapeutic approach is crucial that can control this type of cancer. Phyllanthin is a lignan compound constituent from the Phyllanthus species and has numerous beneficial effects as a dietary component. The present study aims to determine the impact of phyllanthin on the MOLT-4 cytotoxic effect. MOLT-4 cells and MS-5 cells were cultured at different concentrations of phyllanthin (5, 10, 25, 50, 75, and 100 μM/ml), and the viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The level of reactive oxygen species, the membrane potential of mitochondria, apoptosis by 2',7'-dichlorofluorescin-diacetate (DCF-DA), rhodamine, acridine orange (AO)/ethidium bromide (EB), 4',6-diamidino-2-phenylindole (DAPI)/propidium iodide (PI) staining, gene expression of signaling molecules, and protein levels were assessed by reverse-transcription polymerase chain reaction and western blot analysis. Phyllanthin did not show toxicity toward MS-5 cells and significantly decreased the cell viability of MOLT-4 cells with an IC₅₀ value of 25 µM/ml. Also, phyllanthin induced the production of reactive oxygen species and led to the loss of mitochondrial membrane potential. AO/EB and DAPI/PI staining fluorescent image confirmed the induction of apoptosis by phyllanthin treatment. The messenger RNA (mRNA) expression of cell cycle regulator cyclin D1, antiapoptotic gene Bcl-2, NF-κB, and TNF-α decreased, but the proapoptotic Bax mRNA expression was increased. The phosphorylated protein levels of p-PI3K1/2, p-ERK1/2, and p-AKT were decreased, whereas the levels of p-p38 and p-JNKT1/2 increased. Our results confirmed that phyllanthin inhibits the MOLT-4 cells, increases apoptosis, and inhibits MOLT-4 migration and cell invasion. Therefore, phyllanthin can be used as a potential target for leukemia treatment.

Stress kinases in the development of liver steatosis and hepatocellular carcinoma

Non-alcoholic fatty liver disease (NAFLD) is an important component of metabolic syndrome and one of the most prevalent liver diseases worldwide. This disorder is closely linked to hepatic insulin resistance, lipotoxicity, and inflammation. Although the mechanisms that cause steatosis and chronic liver injury in NAFLD remain unclear, a key component of this process is the activation of stress-activated kinases (SAPKs), including p38 and JNK in the liver and immune system. This review summarizes findings which indicate that the dysregulation of stress kinases plays a fundamental role in the development of steatosis and are important players in inducing liver fibrosis. To avoid the development of steatohepatitis and liver cancer, SAPK activity must be tightly regulated not only in the hepatocytes but also in other tissues, including cells of the immune system. Possible cellular mechanisms of SAPK actions are discussed.

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Hepatic JNK triggers steatosis and insulin resistance, decreasing lipid oxidation and ketogenesis in HFD-fed mice.

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Decreased liver expression of p38α/β in HFD increases lipogenesis.

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Hepatic p38γ/δ drive insulin resistance and inhibit autophagy, which may lead to steatosis.

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Macrophage p38α/β promote cytokine production and M1 polarization, leading to lipid accumulation in hepatocytes.

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Myeloid p38γ/δ contribute to cytokine production and neutrophil migration, protecting against steatosis, diabetes and NAFLD.

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JNK1 and p38γ induce HCC while p38α blocks it. However, deletion of hepatic JNK1/2 induces cholangiocarcinoma.

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SAPK are potential therapeutic target for metabolic disorders, steatohepatitis and liver cancer.

Synergism between the phosphatidylinositol 3-kinase p110β isoform inhibitor AZD6482 and the mixed lineage kinase 3 inhibitor URMC-099 on the blockade of glioblastoma cell motility and focal adhesion formation

Background

Glioblastoma multiforme, the most aggressive and malignant primary brain tumor, is characterized by rapid growth and extensive infiltration to neighboring normal brain parenchyma. Our previous studies delineated a crosstalk between PI3K/Akt and JNK signaling pathways, and a moderate anti-glioblastoma synergism caused by the combined inhibition of PI3K p110β (PI3Kβ) isoform and JNK. However, this combination strategy is not potent enough. MLK3, an upstream regulator of ERK and JNK, may replace JNK to exert stronger synergism with PI3Kβ.

Methods

To develop a new combination strategy with stronger synergism, the expression pattern and roles of MLK3 in glioblastoma patient’s specimens and cell lines were firstly investigated. Then glioblastoma cells and xenografts in nude mice were treated with the PI3Kβ inhibitor AZD6482 and the MLK3 inhibitor URMC-099 alone or in combination to evaluate their combination effects on tumor cell growth and motility. The combination effects on cytoskeletal structures such as lamellipodia and focal adhesions were also evaluated.

Results

MLK3 protein was overexpressed in both newly diagnosed and relapsing glioblastoma patients’ specimens. Silencing of MLK3 using siRNA duplexes significantly suppressed migration and invasion, but promoted attachment of glioblastoma cells. Combined inhibition of PI3Kβ and MLK3 exhibited synergistic inhibitory effects on glioblastoma cell proliferation, migration and invasion, as well as the formation of lamellipodia and focal adhesions. Furthermore, combination of AZD6482 and URMC-099 effectively decreased glioblastoma xenograft growth in nude mice. Glioblastoma cells treated with this drug combination showed reduced phosphorylation of Akt and ERK, and decreased protein expression of ROCK2 and Zyxin.

Conclusion

Taken together, combination of AZD6482 and URMC-099 showed strong synergistic anti-tumor effects on glioblastoma in vitro and in vivo. Our findings suggest that combined inhibition of PI3Kβ and MLK3 may serve as an attractive therapeutic approach for glioblastoma multiforme.

Chemopreventive effect of α-hederin/carboplatin combination against experimental colon hyperplasia and impact on JNK signaling

Colon cancer is the commonest cancer worldwide. α-Hederin is a monodesmosidic triterpenoid saponin possessing diverse pharmacological activities. The running experiment was designed to test the chemopreventive activity of α-hederin when used as an adjuvant to carboplatin in an experimental model of mouse colon hyperplasia induced by 1,2-dimethylhydrazine (DMH). Fifty male Swiss albino mice were classified into five groups: group (I): saline group, group (II): DMH-induced colon hyperplasia control group, group (III): DMH + carboplatin (5 mg/kg) group, group (IV): DMH + α-hederin (80 mg/kg) group, and group (V): DMH + carboplatin (5 mg/kg)+α-hederin (80 mg/kg) group. Analyzing of colonic tissue indicated that the disease control group showed higher colon levels of phospho-PI3K to total-PI3K, phospho-AKT to total-AKT and cyclin D1 concurrent with lower phospho-JNK/total JNK ratio and caspase 3. However, treatment with α-hederin, in combination with carboplatin, favorably ameliorated phosphorylation of PI3K/AKT/JNK proteins, increased colon caspase 3 and downregulated cyclin D1. Microscopically, α-hederin, in combination with carboplatin, produced the most reduction in the histologic hyperplasia score, enhanced the goblet cell survival in periodic acid Schiff staining and reduced proliferation (Ki-67 immunostaining) in the current colon hyperplasia model. Collectively, the current study highlighted for the first time that using α-hederin as an adjuvant to carboplatin enhanced its chemopreventive activity, improved JNK signaling and increased apoptosis. Hence, further studies are warranted to test α-hederin as a promising candidate with chemotherapeutic agents in treating colon cancer.

Calycosin induces mitochondrial-dependent apoptosis and cell cycle arrest, and inhibits cell migration through a ROS-mediated signaling pathway in HepG2 hepatocellular carcinoma cells

Calycosin is one of the main ingredients extracted from the Chinese medical herb, Radix astragali (RA). It has been shown to inhibit cell proliferation and induce apoptosis in several cancer cell lines, but the underlying mechanism remains unclear. The effects of calycosin on the proliferation and apoptosis of hepatocellular carcinoma (HCC) cells, as well as its mechanism, were investigated in this study. Cell Counting Kit-8 assay results suggested that calycosin had anti-proliferation effects on HCC in dose- and time-dependent manners, and had less cytotoxicity in normal cells. Hoechst/PI double staining and flow cytometry results showed cellular morphological changes and apoptosis after treatment of HepG2 cells with calycosin. The western blot assay showed calycosin decreased the expression of Bcl-2 and increased the expression of Bax, caspase-3, and PARP. Calycosin induced the activation of MAPK, STAT3, NF-κB, apoptosis-related proteins, and induced cell cycle arrest in the G0/G1 phase by regulating AKT. In addition, calycosin reduced the expression of TGF-β1, SMAD2/3, SLUG, and vimentin. Furthermore, phosphorylation, apoptosis, and cell migration induced by calycosin were mediated by the production of reactive oxygen species. These events could be inhibited by pretreatment with N-acetyl-L-cysteine. Calycosin resisted HCC by activating ROS-mediated MAPK, STAT3, and NF-κB signaling pathways.

IgA Triggers Cell Death of Neutrophils When Primed by Inflammatory Mediators

IVIG preparations consisting of pooled IgG are increasingly used for the treatment of autoimmune diseases. IVIG is known to regulate the viability of immune cells, including neutrophils. We report that plasma-derived IgA efficiently triggers death of neutrophils primed by cytokines or TLR agonists. IgA-mediated programmed neutrophil death was PI3K-, p38 MAPK-, and JNK-dependent and evoked anti-inflammatory cytokines in macrophage cocultures. Neutrophils from patients with acute Crohn's disease, rheumatoid arthritis, or sepsis were susceptible to both IgA- and IVIG-mediated death. In contrast to IVIG, IgA did not promote cell death of quiescent neutrophils. Our findings suggest that plasma-derived IgA might provide a therapeutic option for the treatment of neutrophil-associated inflammatory disorders.

Negative regulation of interleukin 1β expression in response to DnaK from Pseudomonas aeruginosa via the PI3K/PDK1/FoxO1 pathways

Interleukin (IL)-1β is crucial for a wide range of inflammatory responses. Previously, we reported that IL-1β is produced in response to Pseudomonas aeruginosa-derived DnaK via NF-κB and JNK pathways; however, the signaling pathways that counter the process to maintain IL-1β homeostasis are unknown. Here, we show that DnaK-mediated expression of IL1β is increased markedly in macrophages upon blockade of PI3K/PDK1. This was verified by measuring released IL-1β protein. The negative effect of PI3K on IL-1β production was dependent on suppression of both NF-κB and JNK activation. Intriguingly, PDK1 (an underlying mediator of PI3K) acted as an upstream regulator for the activation of NF-κB, but downregulated JNK activation. Furthermore, production of IL-1β and activation of JNK were triggered by inhibition of phosphorylated FoxO1; phosphorylation of FoxO1 was controlled by PDK1 signaling in response to DnaK. Thus, IL-1β production is modulated by P. aeruginosa-derived DnaK via cross-talk between JNK and PI3K/PDK1/FoxO1 pathways.

MicroRNA-294 Promotes Cell Proliferation, Migration and Invasion in SMMC-7721 Hepatoma Carcinoma Cells by Activating the JNK/ERK Signaling Pathway

BACKGROUND

It has been reported that miR-294 is highly expressed in hepatocellular carcinoma (HCC) tissues and cells. However, the potential role of miR-294 in the pathogenesis of HCC remains unclear. This study aimed to explore the role of miR-294 in HCC and the potential mechanism involved in this process.

MATERIALS AND METHODS

Reverse transcription polymerase chain reaction was performed to determine the expression of miR-294 in HCC tissues and cell lines. Following the overexpression or knockdown of miR-294, the proliferation, migration, and invasion abilities of cells were determined using Cell Counting Kit-8 (CCK-8), wound healing and transwell assays, respectively. The phosphorylation of JNK and ERK was determined through western blotting. Furthermore, HCC cells were treated with JNK inhibitor SP600125 or ERK inhibitor U0126 and transfected with miR-294 mimics or negative control. Subsequently, the phosphorylation of JNK and ERK was evaluated and the proliferation, migration and invasion abilities of HCC cells were also determined.

RESULTS

The expression of miR-294 was significantly increased in HCC tissues and cell lines. Following the overexpression of miR-294, proliferation, migration, and invasion were promoted in the SSMC-7721 cell line, and the phosphorylation of JNK and ERK was increased, while silencing of miR-294 led to the opposite result. Use of the JNK or ERK inhibitor to treat SSMC-7721 cells transfected with miR-294 mimics decreased the phosphorylation of JNK and ERK and inhibited the proliferation, migration and invasion abilities of cells.

CONCLUSIONS

miR-294 is important for the development of HCC in terms of the biological activities of cells, and may be a novel therapeutic target for HCC.

Etlingera pavieana extract attenuates TNF-α induced vascular adhesion molecule expression in human endothelial cells through NF-κB and Akt/JNK pathways

The aim of this study was to determine whether ethanol extracts of Etlingera pavieana rhizomes (EPE) can inhibit the expression of ICAM-1 and VCAM-1 in TNF-α-stimulated human vascular endothelial cells. EPE significantly reduced ICAM-1 and VCAM-1 expression in a concentration-dependent manner. EPE also suppressed phospho-IκB level and nuclear translocation of NF-κB. EPE significantly inhibited phosphorylation of JNK and c-Jun, a major component of AP-1, but had no effects on ERK and p38 MAPK pathways. Akt phosphorylation was increased in the presence of EPE, and wortmannin and SP600125 reversed the inhibitory effects of EPE on ICAM-1 and VCAM-1 expression. Furthermore, the active EPE constituents 4-methoxycinnamyl p-coumarate and trans-4-methoxycinnamaldehyde attenuated TNF-α-induced expression of ICAM-1 and VCAM-1. Taken together, our data indicate that EPE protects against vascular inflammation in endothelial cells, in part via NF-κB and Akt/JNK signalings. In future studies, E. pavieana may be developed as a therapeutic agent or dietary supplement for treating and preventing inflammatory diseases.

Synthesis, anticancer activity, and molecular modeling of 1,4-naphthoquinones that inhibit MKK7 and Cdc25

Cell division cycle 25 (Cdc25) and mitogen-activated protein kinase kinase 7 (MKK7) are enzymes involved in intracellular signaling but can also contribute to tumorigenesis. We synthesized and characterized the biological activity of 1,4-naphthoquinones structurally similar to reported Cdc25 and(or) MKK7 inhibitors with anticancer activity. Compound 7 (3-[(1,4-dioxonaphthalen-2-yl)sulfanyl]propanoic acid) exhibited high binding affinity for MKK7 (K_d = 230 nM), which was greater than the affinity of NSC 95397 (K_d = 1.1 μM). Although plumbagin had a lower binding affinity for MKK7, this compound and sulfur-containing derivatives 4 and 6-8 were potent inhibitors of Cdc25A and Cdc25B. Derivative 22e containing a phenylamino side chain was selective for MKK7 versus MKK4 and Cdc25 A/B, and its isomer 22f was a selective inhibitor of Cdc25 A/B. Docking studies performed on several naphthoquinones highlighted interesting aspects concerning the molecule orientation and hydrogen bonding interactions, which could help to explain the activity of the compounds toward MKK7 and Cdc25B. The most potent naphthoquinone-based inhibitors of MKK7 and/or Cdc25 A/B were also screened for their cytotoxicity against nine cancer cell lines and primary human mononuclear cells, and a correlation was found between Cdc25 A/B inhibitory activity and cytotoxicity of the compounds. Quantum chemical calculations using BP86 and ωB97X-D3 functionals were performed on 20 naphthoquinone derivatives to obtain a set of molecular electronic properties and to correlate these properties with cytotoxic activities. Systematic theoretical DFT calculations with subsequent correlation analysis indicated that energy of the lowest unoccupied molecular orbital E(LUMO), vertical electron affinity (VEA), and reactivity index ω of these molecules were important characteristics related to their cytotoxicity. The reactivity index ω was also a key characteristic related to Cdc25 A/B phosphatase inhibitory activity. Thus, 1,4-naphthoquinones displaying sulfur-containing and phenylamino side chains with additional polar groups could be successfully utilized for further development of efficacious Cdc25 A/B and MKK7 inhibitors with anticancer activity.