Amino-terminal phosphorylation of c-Jun regulates stress-induced apoptosis and cellular proliferation

An unscheduled switch to endocycles induces a reversible senescent arrest that impairs growth of the Drosophila wing disc

A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogaster wing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer.

Identification of inhibitors for neurodegenerative diseases targeting dual leucine zipper kinase through virtual screening and molecular dynamics simulations

Neurodegenerative diseases lead to a gradual decline in cognitive and motor functions due to the progressive loss of neurons in the central nervous system. The role of dual leucine zipper kinase (DLK) in regulating stress responses and neuronal death pathways highlights its significance as a target against neurodegenerative diseases. The non-availability of FDA-approved drugs emphasizes a need to identify novel DLK-inhibitors. We screened NPAtlas (Natural products) and MedChemExpress (FDA-approved) libraries to identify potent ATP-competitive DLK inhibitors. ADMET analyses identified four compounds (two natural products and two FDA-approved) with favourable features. Subsequently, we performed molecular dynamics simulations to examine the binding-stability and ligand-induced conformational dynamics. Molecular mechanics Poisson Boltzmann surface area (MM-PBSA) calculations demonstrated CID139591660, dithranol, and danthron having greater affinity, while CID156581477 showed lower affinity than control sunitinib. PCA and network analysis results indicated structural and network alteration post-ligand binding. Furthermore, we identified an analogue of CID156581477 using the deep learning-based web server DeLA Drug which demonstrated a higher affinity than its parent compound and the control and identified several crucial interacting residues. Overall, our study provides significant theoretical guidance for designing potent novel DLK inhibitors and compounds that could emerge as promising drug candidates against DLK following laboratory validation.

Systematic identification of a synthetic lethal interaction in brain-metastatic lung adenocarcinoma

Metastatic lung adenocarcinoma (LuAC) presents a significant clinical challenge due to the short latency and the lack of efficient treatment options. Therefore, identification of molecular vulnerabilities in metastatic LuAC holds great importance in the development of therapeutic drugs against this disease. In this study, we performed a genome-wide siRNA screening using poorly and highly brain-metastatic LuAC cell lines. Using this approach, we discovered that compared to poorly metastatic LuAC (LuAC-Par) cells, brain-metastatic LuAC (LuAC-BrM) cells exhibited a significantly higher vulnerability to c-FLIP (an inhibitor of caspase-8)-depletion-induced apoptosis. Furthermore, in vivo studies demonstrated that c-FLIP knockdown specifically inhibited growth of LuAC-BrM, but not the LuAC-Par, tumors, suggesting the addiction of LuAC-BrM to the function of c-FLIP for their survival. Our in vitro and in vivo analyses also demonstrated that LuAC-BrM is more sensitive to c-FLIP-depletion due to ER stress-induced activation of the c-JUN and subsequent induction of stress genes including ATF4 and DDIT3. Finally, we found that c-JUN not only sensitized LuAC-BrM to c-FLIP-depletion-induced cell death but also promoted brain metastasis in vivo, providing strong evidence for c-JUN's function as a double-edged sword in LuAC-BrM. Collectively, our findings not only reveal a novel link between c-JUN, brain metastasis, and c-FLIP addiction in LuAC-BrM but also present an opportunity for potential therapeutic intervention.

An unscheduled switch to endocycles induces a reversible senescent arrest that impairs growth of the Drosophila wing disc

A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogasterwing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer.

Exome sequencing reveals PPEF2 variant associated with high myopia

High myopia (HM) is a serious blinding eye disease, and genetic factors play an important role in the development of HM. In this study, whole exome sequencing (WES) was used to identify a novel variant c.A875G of the PPEF2 for a large Uyghur family with nonsyndromic HM. The variant was verified to cosegregate with HM in the family using Sanger sequencing. Another novel variant c.1959C > G in PPEF2 was identified in one of 100 sporadic cases of HM by multiplex PCR targeted amplicon sequencing (MTA-seq). The Ppef2 was verified that mainly expressed in the retinal pigment epithelium (RPE), choroid and retina tissues. Immunofluorescence (IF) and immunohistochemistry (IHC) assays showed that the PPEF2 was strongly expressed in the inner segment layer formed by photoreceptor protrusions, as well as in the outer nuclear layer. Compared with the wild-type, the c.A875G resulted in reduced protein levels but had no effect on protein subcellular localization in cells. In addition, the c.A875G variant resulted in a decreased migratory and proliferative capacity but promoted apoptosis in cells. In summary, PPEF2 was identified as a novel HM-causing gene, and this variant in PPEF2 might cause HM by regulating the migration, proliferation and apoptosis of myopia-related cells.

Impact of Complex Apoptotic Signaling Pathways on Cancer Cell Sensitivity to Therapy

Anticancer drugs induce apoptotic and non-apoptotic cell death in various cancer types. The signaling pathways for anticancer drug-induced apoptotic cell death have been shown to differ between drug-sensitive and drug-resistant cells. In atypical multidrug-resistant leukemia cells, the c-Jun/activator protein 1 (AP-1)/p53 signaling pathway leading to apoptotic death is altered. Cancer cells treated with anticancer drugs undergo c-Jun/AP-1-mediated apoptotic death and are involved in c-Jun N-terminal kinase activation and growth arrest- and DNA damage-inducible gene 153 (Gadd153)/CCAAT/enhancer-binding protein homologous protein pathway induction, regardless of the p53 genotype. Gadd153 induction is associated with mitochondrial membrane permeabilization after anticancer drug treatment and involves a coupled endoplasmic reticulum stress response. The induction of apoptosis by anticancer drugs is mediated by the intrinsic pathway (cytochrome c, Cyt c) and subsequent activation of the caspase cascade via proapoptotic genes (e.g., Bax and Bcl-xS) and their interactions. Anticancer drug-induced apoptosis involves caspase-dependent and caspase-independent pathways and occurs via intrinsic and extrinsic pathways. The targeting of antiapoptotic genes such as Bcl-2 enhances anticancer drug efficacy. The modulation of apoptotic signaling by Bcl-xS transduction increases the sensitivity of multidrug resistance-related protein-overexpressing epidermoid carcinoma cells to anticancer drugs. The significance of autophagy in cancer therapy remains to be elucidated. In this review, we summarize current knowledge of cancer cell death-related signaling pathways and their alterations during anticancer drug treatment and discuss potential strategies to enhance treatment efficacy.

The Role of the Dysregulated JNK Signaling Pathway in the Pathogenesis of Human Diseases and Its Potential Therapeutic Strategies: A Comprehensive Review

JNK is named after c-Jun N-terminal kinase, as it is responsible for phosphorylating c-Jun. As a member of the mitogen-activated protein kinase (MAPK) family, JNK is also known as stress-activated kinase (SAPK) because it can be activated by extracellular stresses including growth factor, UV irradiation, and virus infection. Functionally, JNK regulates various cell behaviors such as cell differentiation, proliferation, survival, and metabolic reprogramming. Dysregulated JNK signaling contributes to several types of human diseases. Although the role of the JNK pathway in a single disease has been summarized in several previous publications, a comprehensive review of its role in multiple kinds of human diseases is missing. In this review, we begin by introducing the landmark discoveries, structures, tissue expression, and activation mechanisms of the JNK pathway. Next, we come to the focus of this work: a comprehensive summary of the role of the deregulated JNK pathway in multiple kinds of diseases. Beyond that, we also discuss the current strategies for targeting the JNK pathway for therapeutic intervention and summarize the application of JNK inhibitors as well as several challenges now faced. We expect that this review can provide a more comprehensive insight into the critical role of the JNK pathway in the pathogenesis of human diseases and hope that it also provides important clues for ameliorating disease conditions.

Cold Stress Induces Apoptosis in Silver Pomfret via DUSP-JNK Pathway

We cultured silver pomfret for 20 days, decreasing water temperature from 18 to 8 ℃, and sampled muscle every 5 days. Muscle fiber degeneration and apoptosis began to increase at 13 ℃ detected by HE and TUNEL staining. Further analysis of transcriptome revealed that several apoptosis-related pathways were highly enriched by differentially expressed genes (DEGs). We analyzed 10 DEGs from these pathways by RT-qPCR during the temperature-decreasing process. JNK1, PIDD, CytC, Casp 3, and GADD45 were up-regulated after 15 and 20 days, while DUSP3, JNK2, and PARP genes were down-regulated after 15 and 20 days. DUSP5 was up-regulated from 10 to 20 days, and C-JUN was up-regulated after 20 days. We analyzed apoptosis in PaM cells under different temperatures (26 ℃, 23 ℃, 20 ℃, 17 ℃, and 14 ℃). The cell viability significantly declined from 14 to 20 ℃; the TUNEL and IHC results showed that the apoptosis signal increased with the temperature dropping, especially in 17 ℃ and 14 ℃; DUSP5, JNK1, CytC, C-JUN, Casp 3, and GADD45 were up-regulated at 17 ℃ and 14 ℃, and PIDD was up-regulated at 20 ℃, 17 ℃, and 14 ℃. DUSP3 was up-regulated at 20 ℃ but down-regulated at 17 ℃ and 14 ℃, and PARP was down-regulated at 17 ℃ and 14 ℃. JNK2 was up-regulated at 20 ℃ but down-regulated at 17 ℃ and 14 ℃. Our results suggest that DUSP could help inhibit apoptosis in the initial stage of cold stress, but low temperature could down-regulate it and up-regulate JNK-C-JUN, inducing apoptosis in a later stage. These data provide a basis for the study of the response mechanism of fish to cold.

Loss of DJ-1 function contributes to Parkinson's disease pathogenesis in mice via RACK1-mediated PKC activation and MAO-B upregulation

Parkinson's disease (PD) is a common neurodegenerative motor disorder characterized by a dramatic reduction in pars compacta of substantia nigra dopaminergic neurons and striatal dopamine (DA) levels. Mutations or deletions in the PARK7/DJ-1 gene are associated with an early-onset familial form of PD. DJ-1 protein prevents neurodegeneration via its regulation of oxidative stress and mitochondrial function as well as its roles in transcription and signal transduction. In this study, we investigated how loss of DJ-1 function affected DA degradation, ROS generation and mitochondrial dysfunction in neuronal cells. We showed that loss of DJ-1 significantly increased the expression of monoamine oxidase (MAO)-B but not MAO-A in both neuronal cells and primary astrocytes. In DJ-1-knockout (KO) mice, MAO-B protein levels in the substantia nigra (SN) and striatal regions were significantly increased. We demonstrated that the induction of MAO-B expression by DJ-1 deficiency depended on early growth response 1 (EGR1) in N2a cells. By coimmunoprecipitation omics analysis, we found that DJ-1 interacted with receptor of activated protein C kinase 1 (RACK1), a scaffolding protein, and thus inhibited the activity of the PKC/JNK/AP-1/EGR1 cascade. The PKC inhibitor sotrastaurin or the JNK inhibitor SP600125 completely inhibited DJ-1 deficiency-induced EGR1 and MAO-B expression in N2a cells. Moreover, the MAO-B inhibitor rasagiline inhibited mitochondrial ROS generation and rescued neuronal cell death caused by DJ-1 deficiency, especially in response to MPTP stimulation in vitro and in vivo. These results suggest that DJ-1 exerts neuroprotective effects by inhibiting the expression of MAO-B distributed at the mitochondrial outer membrane, which mediates DA degradation, ROS generation and mitochondrial dysfunction. This study reveals a mechanistic link between DJ-1 and MAO-B expression and contributes to understanding the crosslinks among pathogenic factors, mitochondrial dysfunction and oxidative stress in PD pathogenesis.

Plant derived active compounds of ayurvedic neurological formulation, Saraswatharishta as a potential dual leucine zipper kinase inhibitor: an in-silico study

Recent findings have highlighted the essential role of dual leucine zipper kinase (DLK) in neuronal degeneration. Saraswatharishta (SWRT), an ayurvedic formulation utilized in traditional Indian medicine, has demonstrated effectiveness in addressing neurodegenerative diseases. Herein, we aim to delve into the atomistic details of the mode of action of phytochemicals present in SWRT against DLK. Our screening process encompassed over 500 distinct phytochemicals derived from the main ingredients of the SWRT formulation. Through a comparative analysis of docking scores and relative poses, we successfully identified four novel compounds, which underwent further investigation via 2 × 500 ns long molecular dynamics (MD) simulations. Among the top four compounds, CID16066851 sourced from the Acorus calamus displayed the most stable complex with DLK. The molecular mechanics Poisson - Boltzmann surface area (MM-PBSA) calculations highlighted the significance of electrostatic and van der Waals interactions in the binding recognition process. Additionally, we identified key residues, namely Phe192, Leu243, Val139, and Leu141, as hotspots that predominantly govern the DLK-inhibitor interaction. Notably, the leading compounds are sourced from the Acorus calamus, Syzygium aromaticum, Zingiber officinale, and Anethum sowa plants present in the SWRT formulation. Overall, the findings of our study hold promise for future drug development endeavors combating neurodegenerative conditions.Communicated by Ramaswamy H. Sarma.

Breast cancer stem cells tolerate chromosomal instability during tumor progression via c-Jun/AXL stress signaling

Chromosomal instability (CIN) is critical for tumor evolution, yet its relationship with stemness is unclear. Here, we describe CIN as a key stress induced during tumor initiation that is uniquely tolerated by breast cancer stem cells in an activated signaling state (aCSCs). While we noted elevated CIN specifically in tumors from aCSCs, this was not intrinsic to these cells, as baseline levels were similar to non-stem cell types. This suggests that CIN is induced during tumor initiation, and that aCSCs can better tolerate this stress. Further, this increased CIN may be transient, as it was only in low-burden aCSC tumors, with levels diminishing in more established disease. Phospho-array profiling revealed specific activation of c-Jun stress signaling in aCSCs, which we hypothesized could induce genes responsible for CIN tolerance. Indeed, we identified AXL as a c-Jun dependent gene enriched in aCSCs that enhances resistance to this stress. Thus, CIN tolerance mediated by c-Jun/AXL signaling may be a defining feature of stemness, contributing to breast cancer progression.

Dynamic mapping of proteome trafficking within and between living cells by TransitID

The ability to map trafficking for thousands of endogenous proteins at once in living cells would reveal biology currently invisible to both microscopy and mass spectrometry. Here, we report TransitID, a method for unbiased mapping of endogenous proteome trafficking with nanometer spatial resolution in living cells. Two proximity labeling (PL) enzymes, TurboID and APEX, are targeted to source and destination compartments, and PL with each enzyme is performed in tandem via sequential addition of their small-molecule substrates. Mass spectrometry identifies the proteins tagged by both enzymes. Using TransitID, we mapped proteome trafficking between cytosol and mitochondria, cytosol and nucleus, and nucleolus and stress granules (SGs), uncovering a role for SGs in protecting the transcription factor JUN from oxidative stress. TransitID also identifies proteins that signal intercellularly between macrophages and cancer cells. TransitID offers a powerful approach for distinguishing protein populations based on compartment or cell type of origin.

Iodine-Biofortified Lettuce Can Promote Mitochondrial Dependent Pathway of Apoptosis in Human Gastrointestinal Cancer Cells

Previously, our research provided evidence that exposure of gastric and colon cancer cells to extracts from iodine-biofortified lettuce leads to a reduction of cell viability and proliferation through cell cycle arrest and upregulation of pro-apoptotic genes. The aim of the present study was to determine the potential cellular mechanisms of induction of cell death in human gastrointestinal cancer cell lines after treatment with iodine-biofortified lettuce. We demonstrated that extracts from lettuce enriched with iodine induce apoptosis in gastric AGS and colon HT-29 cancer cells and the mechanism of programmed cell death may be triggered and executed through different signaling pathways, depending on the type of cells. Western blot analysis revealed that iodine-fortified lettuce leads to cell death through the release of cytochrome c to the cytosolic fraction and activation of the primary drivers of apoptosis: caspase-3, caspase-7, and caspase-9. Furthermore, we have reported that apoptotic effects of lettuce extracts may be mediated by poly (ADP-ribose) polymerase (PARP) and activation of pro-apoptotic Bcl-2 family proteins such as Bad, Bax, and BID. We also observed mitochondrial dysfunction with the dissipation of the mitochondrial membrane potential in cells exposed to lettuce extracts. Taken together, these results indicate that the organic form of iodine such as 5-ISA and 3,5-diISA is an important factor in the activation of intrinsic mitochondrial apoptotic pathway in AGS and HT-29 cancer cells in a p53-independent manner.

Identification of Key Ferroptosis-Related Genes in the Peripheral Blood of Patients with Relapsing-Remitting Multiple Sclerosis and Its Diagnostic Value

Multiple sclerosis (MS) is a neurodegenerative disease with a complex pathogenesis. Re-lapsing-remitting multiple sclerosis (RRMS) is the most common subset of MS, accounting for approximately 85% of cases. Recent studies have shown that ferroptosis may contribute to the progression of RRMS, but the underlying mechanism remains to be elucidated. Herein, this study intended to explore the molecular network of ferroptosis associated with RRMS and establish a predictive model for efficacy diagnosis. Firstly, RRMS-related module genes were identified using weighted gene co-expression network analysis (WGCNA). Secondly, the optimal machine learning model was selected from four options: the generalized linear model (GLM), random forest model (RF), support vector machine model (SVM), and extreme gradient boosting model (XGB). Subsequently, the predictive efficacy of the diagnostic model was evaluated using receiver operator characteristic (ROC) analysis. Finally, a SVM diagnostic model based on five genes (JUN, TXNIP, NCOA4, EIF2AK4, PIK3CA) was established, and it demonstrated good predictive performance in the validation dataset. In summary, our study provides a systematic exploration of the complex relationship between ferroptosis and RRMS, which may contribute to a better understanding of the role of ferroptosis in the pathogenesis of RRMS and provide promising diagnostic strategies for RRMS patients.

Dynamic mapping of proteome trafficking within and between living cells by TransitID

The ability to map trafficking for thousands of endogenous proteins at once in living cells would reveal biology currently invisible to both microscopy and mass spectrometry. Here we report TransitID, a method for unbiased mapping of endogenous proteome trafficking with nanometer spatial resolution in living cells. Two proximity labeling (PL) enzymes, TurboID and APEX, are targeted to source and destination compartments, and PL with each enzyme is performed in tandem via sequential addition of their small-molecule substrates. Mass spectrometry identifies the proteins tagged by both enzymes. Using TransitID, we mapped proteome trafficking between cytosol and mitochondria, cytosol and nucleus, and nucleolus and stress granules, uncovering a role for stress granules in protecting the transcription factor JUN from oxidative stress. TransitID also identifies proteins that signal intercellularly between macrophages and cancer cells. TransitID introduces a powerful approach for distinguishing protein populations based on compartment or cell type of origin.

Canopy Homolog 2 contributes to liver oncogenesis by promoting unfolded protein response-dependent destabilization of tumor protein P53

BACKGROUD AND AIMS

Abnormalities in the tumor protein P53 (p53) gene and overexpression of mouse double minute 2 homolog (MDM2), a negative regulator of p53, are commonly observed in cancers. p53 destabilization is regulated by endoplasmic reticulum (ER) stress and unfolded protein response (UPR) in cancer. However, the mechanisms remain enigmatic. Canopy homolog 2 (CNPY2) is a key UPR initiator that primarily involved in ER stress and is highly expressed in the liver, but its functional role in regulating liver carcinogenesis is poorly understood. Therefore, we aimed to investigate the role of CNPY2 in hepartocarcinogenesis through URP-dependent p53 destabilization.

APPROACH AND RESULTS

Here, we showed that CNPY2 expression is up-regulated in HCC and negatively correlated with survival rate in liver cancer patients. Deletion of Cnpy2 obliterates diethylnitrosamine (DEN)-induced HCC in mice. Mechanistic studies demonstrated that CNPY2 binds and prevents ribosome proteins from inhibiting MDM2 and enhances the UPR activity of protein kinase RNA-like endoplasmic reticulum kinase and inositol-requiring transmembrane kinase endoribonuclease-1α, leading to p53 destabilization and cell-cycle progression. In addition, transcriptome analyses uncovered that CNPY2 is also required for DEN-induced expression of oncogenes, including c-Jun and fibroblast growth factor 21. Intratumoral injection of nanoparticle-based CRISPR single-guide RNA/CRISPR-associated protein 9 mRNA against Cnpy2 has antitumor effects in HCC.

CONCLUSIONS

These findings demonstrate that CNPY2 is crucial for liver oncogenesis through UPR-dependent repression of p53 and activation of oncogenes, providing insights into the design of a therapeutic target for HCC.

An intrinsic temporal order of c-JUN N-terminal phosphorylation regulates its activity by orchestrating co-factor recruitment

Protein phosphorylation is a major regulatory mechanism of cellular signalling. The c-JUN proto-oncoprotein is phosphorylated at four residues within its transactivation domain (TAD) by the JNK family kinases, but the functional significance of c-JUN multisite phosphorylation has remained elusive. Here we show that c-JUN phosphorylation by JNK exhibits defined temporal kinetics, with serine63 and serine73 being phosphorylated more rapidly than threonine91 and threonine93. We identify the positioning of the phosphorylation sites relative to the kinase docking motif, and their primary sequence, as the main factors controlling phosphorylation kinetics. Functional analysis reveals three c-JUN phosphorylation states: unphosphorylated c-JUN recruits the MBD3 repressor, serine63/73 doubly-phosphorylated c-JUN binds to the TCF4 co-activator, whereas the fully phosphorylated form disfavours TCF4 binding attenuating JNK signalling. Thus, c-JUN phosphorylation encodes multiple functional states that drive a complex signalling response from a single JNK input.

MMP-12 polarizes neutrophil signalome towards an apoptotic signature

While macrophages are well-known to polarize across the inflammatory spectrum, neutrophils have only recently been found to activate in a similar fashion in response to pro- or anti-inflammatory stimuli. Matrix metalloproteinase (MMP)-12 mediates neutrophil physiology with direct signaling mechanisms yet to be investigated. We hypothesized MMP-12 may modify neutrophil signaling. Bone marrow neutrophils were stimulated with interleukin (IL-1β; pro-inflammatory), IL-4 (anti-inflammatory), or MMP-12. The secretome was mapped by multi-analyte profiling and intracellular signaling evaluated by array. IL-1β induced a cytokine-mediated inflammatory LPS-like signalome, with upregulation of pro-inflammatory cytokines such as interferon gamma (IFNγ,15.2-fold,p = 0.001), chemokine (C-X-C motif) ligand 1 (CXCL1,8.4-fold,p = 0.005), and tumor necrosis factor alpha (TNFα,11.2-fold,p = 0.004). IL-4 induced strong intracellular signaling with upregulation of mitogen-activated protein kinase kinase (MEK1;1.9-fold,p = 0.0005) and downregulation of signal transducer and activator of transcription 4 (STAT4;0.77-fold,0.001). MMP-12 increased IL-4 secretion 20-fold and induced a robust apoptotic neutrophil signalome with upregulation of forkhead box O1 (FOXO1;1.4-fold,p < 0.0001) and downregulation of WNT signaling with MMP-12 cleavage of the adherens junction components β-catenin, cahderin-3, and catenin-α2. In conclusion, neutrophils shifted phenotype by stimuli, with MMP-12 inducing a unique apoptotic signalome with higher resemblance to the anti-inflammatory signalome. SIGNIFICANCE: This study revealed that neutrophils demonstrate unique polarization signaling responses to specific stimuli, with the matrix metalloproteinase (MMP)-12 signalome showing similarity to the IL-4 signalome. MMP-12 polarized neutrophils towards a strong apoptotic signature by upregulating FOXO1 and downregulating WNT signaling. Our results highlight that neutrophils display more plasticity than previously appreciated.

Tanshinol suppresses osteosarcoma by specifically inducing apoptosis of U2-OS cells through p53-mediated mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Salviae miltiorrhizae (also called Danshen in traditional Chinese medicine) is a famous herbal medicine, which has been frequently used to treat blood stasis syndrome including osteosarcoma (OS) in traditional Chinese medicine. Main components of Danshen have been assumed to exhibit anti-OS capacity. Nevertheless, tanshinol (TS, main component of Danshen)'s efficacy and mechanism in OS hasn't been clearly described ever since. This drew our attention, since OS is the most frequent primary bone carcinomas in children and adolescents, with a high incidence and fatality rate. Unfortunately, chemotherapy for OS has faced many clinical challenges due to the increasing chemoresistance and recurrence. This study was then designed to deeply explore TS's role in OS therapy.

AIM OF THE STUDY

To explore the anti-OS efficacy and mechanism of TS, we conducted in vivo and in vitro experiments by using a zebrafish xenograft model and U2-OS cells.

MATERIALS AND METHODS

CCK-8 assay, DAPI and γ-H2A.X immunofluorescence staining, and flow cytometry (apoptosis verification) were employed to determine the anti-proliferative and pro-apoptotic effects of TS. qPCR and Western blot were used to examine TS's molecular actions and mechanism on apoptosis of U2-OS cells.

RESULTS

The in vivo data showed that TS significantly inhibited U2-OS tumor growth in larval zebrafish from 2 to 20 ng/mL. In vitro data indicated that TS exerted significant anti-proliferative and pro-apoptotic effects on U2-OS cells in a dose-dependent manner. Moreover, TS has no inhibitory effect on bMSCs, suggesting its safety on normal bone-forming cells. Molecular data illustrated that TS obviously activated the p53 signaling-related proteins (p-p53, Bax, CASP3, CASP9) and its upstream JNK (p-JNK, p-c-JUN) and ATM (p-ATM) signaling molecules through phosphorylation and cleavage, followed by up-regulation of the pro-apoptotic genes, NOXA, PUMA, TP53, BAX, and BIM, and down-regulation of Bcl-2 protein.

CONCLUSION

In sum, TS specifically induced apoptosis of U2-OS cells by activating p53 signaling pathways, indicating TS as a promising candidate for OS treatment.

Green tea-derived theabrownin suppresses human non-small cell lung carcinoma in xenograft model through activation of not only p53 signaling but also MAPK/JNK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

According to the theory and practice of traditional Chinese medicine (TCM), the pathogenesis of lung carcinoma is associated with many syndromes, such as "sputum stasis", "cough", "lung fever", "lung toxin", and "hemoptysis", which should be removed for therapeutic purpose. Tea is not only a world-wide beverage, but also a TCM herb, possessing activities against the above syndromes. Recently, green tea extract exerted inhibitory effects on a variety of tumor cells. As a pigment active substance of green tea, theabrownin (TB) has been found to inhibit many cancer cells.

AIM OF THE STUDY

This study focused on the efficacy and mechanism of TB on non-small cell lung cancer (NSCLC) cell lines. The in vivo efficacy of TB on p53-deficient NSCLC (H1299) cells and p53-wild type NSCLC (A549) cells NSCLC cells were determined, and its mechanism of action was explored.

MATERIALS AND METHODS

In vivo, two lung cancer cell lines, H1299 (p53-deficient) and A549 (p53-wild type) were selected to establish xenograft models of larval zebrafish, respectively. For in vitro experiments, wound healing assay, DAPI staining, TUNEL assay, immunofluorescence assay, and flow cytometry were conducted in these two cell lines. RNA sequencing (RNAseq), real time PCR (qPCR) and Western blot (WB) were performed for the mechanism study.

RESULTS

The in vivo results showed that TB significantly inhibited the H1299 and the A549 xenograft tumor growth in larval zebrafish (dosage ranged from 2.13 to 21.3 μg/ml). Wound healing assay results showed that TB suppressed the migration of H1299 cells. DAPI staining, TUNEL assay, and immunofluorescence assay results showed that TB inhibited the growth of H1299 cells by inducing apoptosis. RNAseq, qPCR and WB data showed that TB significantly up-regulated the MAPK/JNK pathway-related proteins (ASK-1, JNK and c-JUN) through phosphorylation activation, accompanying with down-regulation of the epithelial-mesenchymal transition (EMT)-associated genes (N-CADHERIN, SLUG, FIBROWNECTIN and ZEB1) and anti-apoptotic molecules (BCL-2), and up-regulation of the metastasis-related gene HSPA6 and the pro-apoptotic molecules (BIM, BAX, PARP, c-PARP, γ-H2A.X, c-CASP3, c-CASP8, c-CASP9, DDIT3 and DUSP8).

CONCLUSION

This study determined the in vivo efficacy of green tea-derived TB on p53-deficient NSCLC (H1299) cells and p53-wild type NSCLC (A549) cells and clarified its p53-independent mechanism mediated by the activation of MAPK/JNK signaling pathway.

MiRNA-363-3p/DUSP10/JNK axis mediates chemoresistance by enhancing DNA damage repair in diffuse large B-cell lymphoma

Anthracycline-based chemotherapy resistance represents a major challenge in diffuse large B-cell lymphoma (DLBCL). MiRNA and gene expression profiles (n = 47) were determined to uncover potential chemoresistance mechanisms and therapeutic approaches. An independent correlation between high expression of miRNA-363-3p and chemoresistance was observed and validated in a larger cohort (n = 106). MiRNA-363-3p was shown to reduce doxorubicin-induced apoptosis and tumor shrinkage in in vitro and in vivo experiments by ectopic expression and CRISPR/Cas9-mediated knockout in DLBCL cell lines. DNA methylation was found to participate in transcriptional regulation of miRNA-363-3p. Further investigation revealed that dual specificity phosphatase 10 (DUSP10) is a target of miRNA-363-3p and its suppression promotes the phosphorylation of c-Jun N-terminal kinase (JNK). The miRNA-363-3p/DUSP10/JNK axis was predominantly associated with negative regulation of homologous recombination (HR) and DNA repair pathways. Ectopic expression of miRNA-363-3p more effectively repaired doxorubicin-induced double-strand break (DSB) while enhancing non-homologous end joining repair and reducing HR repair. Targeting JNK and poly (ADP-ribose) polymerase 1 significantly inhibited doxorubicin-induced DSB repair, increased doxorubicin-induced cell apoptosis and tumor shrinkage, and improved the survival of tumor-bearing mice. In conclusion, the miRNA-363-3p/DUSP10/JNK axis is a novel chemoresistance mechanism in DLBCL that may be reversed by targeted therapy.

Genetic Control of MAP3K1 in Eye Development and Sex Differentiation

The MAP3K1 is responsible for transmitting signals to activate specific MAP2K-MAPK cascades. Following the initial biochemical characterization, genetic mouse models have taken center stage to elucidate how MAP3K1 regulates biological functions. To that end, mice were generated with the ablation of the entire Map3k1 gene, the kinase domain coding sequences, or ubiquitin ligase domain mutations. Analyses of the mutants identify diverse roles that MAP3K1 plays in embryonic survival, maturation of T/B cells, and development of sensory organs, including eye and ear. Specifically in eye development, Map3k1 loss-of-function was found to be autosomal recessive for congenital eye abnormalities, but became autosomal dominant in combination with Jnk and RhoA mutations. Additionally, Map3k1 mutation increased eye defects with an exposure to environmental agents such as dioxin. Data from eye developmental models reveal the nexus role of MAP3K1 in integrating genetic and environmental signals to control developmental activities. Here, we focus the discussions on recent advances in understanding the signaling mechanisms of MAP3K1 in eye development in mice and in sex differentiation from human genomics findings. The research works featured here lead to a deeper understanding of the in vivo signaling network, the mechanisms of gene-environment interactions, and the relevance of this multifaceted protein kinase in disease etiology and pathogenesis.

Integration of Transcriptomics and Metabolomics to Reveal the Molecular Mechanisms Underlying Rhodium Nanoparticles-Based Photodynamic Cancer Therapy

Rhodium nanoparticles have recently been described as promising photosensitizers due to their low toxicity in the absence of near-infrared irradiation, but their high cytotoxicity when irradiated. Irradiation is usually carried out with a laser source, which allows the treatment to be localized in a specific area, thus avoiding undesirable side effects on healthy tissues. In this study, a multi-omics approach based on the combination of microarray-based transcriptomics and mass spectrometry-based untargeted and targeted metabolomics has provided a global picture of the molecular mechanisms underlying the anti-tumoral effect of rhodium nanoparticle-based photodynamic therapy. The results have shown the ability of these nanoparticles to promote apoptosis by suppressing or promoting anti- and pro-apoptotic factors, respectively, and by affecting the energy machinery of tumor cells, mainly blocking the β-oxidation, which is reflected in the accumulation of free fatty acids and in the decrease in ATP, ADP and NAD+ levels.

Intake of Products Containing Anthocyanins, Flavanols, and Flavanones, and Cognitive Function: A Narrative Review

The purpose of this review is to examine human research studies published within the past 6 years which evaluate the role of anthocyanin, flavanol, and flavanone consumption in cognitive function, and to discuss potential mechanisms of action underlying any observed benefits. Evidence to date suggests the consumption of flavonoid-rich foods, such as berries and cocoa, may have the potential to limit, or even reverse, age-related declines in cognition. Over the last 6 years, the flavonoid subgroups of anthocyanins, flavanols, and flavanones have been shown to be beneficial in terms of conferring neuroprotection. The mechanisms by which flavonoids positively modulate cognitive function are yet to be fully elucidated. Postulated mechanisms include both direct actions such as receptor activation, neurotrophin release and intracellular signaling pathway modulation, and indirect actions such as enhancement of cerebral blood flow. Further intervention studies conducted in diverse populations with sufficient sample sizes and long durations are required to examine the effect of consumption of flavonoid groups on clinically relevant cognitive outcomes. As populations continue to focus on adopting healthy aging strategies, dietary interventions with flavonoids remains a promising avenue for future research. However, many questions are still to be answered, including identifying appropriate dosage, timeframes for intake, as well as the best form of flavonoids, before definitive conclusions can be drawn about the extent to which their consumption can protect the aging brain.

Protein Phosphorylation in Cancer: Role of Nitric Oxide Signaling Pathway

Nitric oxide (NO), a free radical, plays a critical role in a wide range of physiological and pathological processes. Due to its pleiotropic function, it has been widely investigated in various types of cancers and is strongly associated with cancer development. Mounting pieces of evidence show that NO regulates various cancer-related events, which mainly depends on phosphorylating the key proteins in several signaling pathways. However, phosphorylation of proteins modulated by NO signaling pathway may lead to different effects in different types of cancer, which is complex and remains unclear. Therefore, in this review, we focus on the effect of protein phosphorylation modulated by NO signaling pathway in different types of cancers including breast cancer, lung cancer, prostate cancer, colon cancer, gastric cancer, pancreatic cancer, ovarian cancer, and neuroblastoma. Phosphorylation of key proteins, including p38 MAPK, ERK, PI3K, STAT3, and p53, modified by NO in various signaling pathways affects different cancer-related processes including cell apoptosis, proliferation, angiogenesis, metastasis, and several cancer therapies. Our review links the NO signaling pathway to protein phosphorylation in cancer development and provides new insight into potential targets and cancer therapy.

JunD, not c-Jun, is the AP-1 transcription factor required for Ras-induced lung cancer

The AP-1 transcription factor c-Jun is required for Ras-driven tumorigenesis in many tissues and is considered as a classical proto-oncogene. To determine the requirement for c-Jun in a mouse model of K-RasG12D-induced lung adenocarcinoma, we inducibly deleted c-Jun in the adult lung. Surprisingly, we found that inactivation of c-Jun, or mutation of its JNK phosphorylation sites, actually increased lung tumor burden. Mechanistically, we found that protein levels of the Jun family member JunD were increased in the absence of c-Jun. In c-Jun-deficient cells, JunD phosphorylation was increased, and expression of a dominant-active JNKK2-JNK1 transgene further increased lung tumor formation. Strikingly, deletion of JunD completely abolished Ras-driven lung tumorigenesis. This work identifies JunD, not c-Jun, as the crucial substrate of JNK signaling and oncogene required for Ras-induced lung cancer.

High-throughput kinase inhibitor screening reveals roles for Aurora and Nuak kinases in neurite initiation and dendritic branching

Kinases are essential regulators of a variety of cellular signaling processes, including neurite formation—a foundational step in neurodevelopment. Aberrant axonal sprouting and failed regeneration of injured axons are associated with conditions like traumatic injury, neurodegenerative disease, and seizures. Investigating the mechanisms underlying neurite formation will allow for identification of potential therapeutics. We used a kinase inhibitor library to screen 493 kinase inhibitors and observed that 45% impacted neuritogenesis in Neuro2a (N-2a) cells. Based on the screening, we further investigated the roles of Aurora kinases A, B, and C and Nuak kinases 1 and 2. The roles of Aurora and Nuak kinases have not been thoroughly studied in the nervous system. Inhibition or overexpression of Aurora and Nuak kinases in primary cortical neurons resulted in various neuromorphological defects, with Aurora A regulating neurite initiation, Aurora B and C regulating neurite initiation and elongation, all Aurora kinases regulating arborization, and all Nuak kinases regulating neurite initiation and elongation and arborization. Our high-throughput screening and analysis of Aurora and Nuak kinases revealed their functions and may contribute to the identification of therapeutics.

AP-1 subunits converge promiscuously at enhancers to potentiate transcription

The AP-1 transcription factor (TF) dimer contributes to many biological processes and environmental responses. AP-1 can be composed of many interchangeable subunits. Unambiguously determining the binding locations of these subunits in the human genome is challenging because of variable antibody specificity and affinity. Here, we definitively establish the genome-wide binding patterns of five AP-1 subunits by using CRISPR to introduce a common antibody tag on each subunit. We find limited evidence for strong dimerization preferences between subunits at steady state and find that, under a stimulus, dimerization patterns reflect changes in the transcriptome. Further, our analysis suggests that canonical AP-1 motifs indiscriminately recruit all AP-1 subunits to genomic sites, which we term AP-1 hotspots. We find that AP-1 hotspots are predictive of cell type–specific gene expression and of genomic responses to glucocorticoid signaling (more so than super-enhancers) and are significantly enriched in disease-associated genetic variants. Together, these results support a model where promiscuous binding of many AP-1 subunits to the same genomic location play a key role in regulating cell type–specific gene expression and environmental responses.

Sex-Dependent Molecular Mechanisms of Lipotoxic Injury in Brain Microvasculature: Implications for Dementia

Cardiovascular risk factors and biologic sex play a role in vascular dementia which is characterized by progressive reduction in cognitive function and memory. Yet, we lack understanding about the role sex plays in the molecular mechanisms whereby lipid stress contributes to cognitive decline. Five-week-old low-density lipoprotein deficient (LDL-R -/-) male and female mice and C57BL/6J wild types (WT) were fed a control or Western Diet for 8 weeks. Differential expression of protein coding and non-protein coding genes (DEG) were determined in laser captured hippocampal microvessels using genome-wide microarray, followed by bioinformatic analysis of gene networks, pathways, transcription factors and sex/gender-based analysis (SGBA). Cognitive function was assessed by Y-maze. Bioinformatic analysis revealed more DEGs in females (2412) compared to males (1972). Hierarchical clusters revealed distinctly different sex-specific gene expression profiles irrespective of diet and genotype. There were also fewer and different biologic responses in males compared to females, as well as different cellular pathways and gene networks (favoring greater neuroprotection in females), together with sex-specific transcription factors and non-protein coding RNAs. Hyperlipidemic stress also resulted in less severe cognitive dysfunction in females. This sex-specific pattern of differential hippocampal microvascular RNA expression might provide therapeutic targets for dementia in males and females.

Theabrownin Induces Apoptosis and Tumor Inhibition of Hepatocellular Carcinoma Huh7 Cells Through ASK1-JNK-c-Jun Pathway

Purpose

Theabrownin (TB), a main pigment and bioactive component of tea, has been shown anti-tumor activities against carcinomas, but its effects on hepatocellular carcinoma (HCC) remain unclear.

Methods

Hepatocellular carcinoma Huh7 cells were used for analyses. Cell viability assay was performed to determine TB′s anti-proliferative effect, and flow cytometry with annexin V-FITC/PI double staining and DAPI staining were performed to determine its pro-apoptotic effect. Real-time PCR and Western blot assays were conducted to detect the molecular actions of TB. And a xenograft model of zebrafishes was established to evaluate the in vivo effect of TB. SP600125 (JNK inhibitor) was in vivo and in vitro used to verify the regulatory role of the JNK signaling pathway in the anti-hepatic carcinoma mechanism of TB.

Results

TB exerted significant anti-proliferative and pro-apoptotic effects on Huh7 cells in a dose-dependent manner. The molecular data showed that TB up-regulated the gene expressions of NOXA, PUMA, P21, Bax, and Bim and up-regulated the protein expressions of ASK-1, Bax, phosphorylated JNK, and phosphorylated c-Jun with down-regulation of Bcl-2. The in vivo data showed that TB exerted significant tumor-inhibitory effect which was even stronger than that of cis-platinum. Furthermore, the JNK inhibitor significantly weakened TB′s effects both in vivo and in vitro and blocked the related molecular pathway.

Conclusion

TB exerts anti-proliferative, pro-apoptotic, and tumor-inhibitory effects on Huh7 cells through activation of the JNK signaling pathway. For the first time, this study provides new evidence of anti-HCC effects and mechanism of TB.

The c-Jun signaling pathway has a protective effect on nucleus pulposus cells in patients with intervertebral disc degeneration

Among a range of diverse clinical symptoms, intervertebral disc degeneration (IDD) contributes mostly to the onset of lower back pain. The present study aimed to investigate the effects of c-Jun on nucleus pulposus (NP) cells of IDD and its regulation on molecular mechanisms. Intervertebral disc (IVD) tissues were collected from patients suffering from IDD disease, and NP cells were subsequently isolated and cultured. By overexpressing c-Jun in NP cells, expression levels of mRNAs and proteins of IDD-related genes and inflammatory cytokines were subjected to reverse transcription-quantitative PCR, western blot and ELISA assays. Additional transforming growth factor-β (TGF-β) antibodies were administrated to suppress the function of TGF-β. Cell proliferation and apoptosis were determined via Cell Counting Kit-8 and TUNEL assays, respectively. The results demonstrated that the overexpression of c-Jun robustly upregulated both mRNA and protein expression of TGF-β, TIMP metallopeptidase inhibitor 3, aggrecan and collagen type II alpha 1 chain and simultaneously downregulated the expression of the inflammatory cytokines TNF-α, interleukin (IL)-1β, IL-6 and IL-17. Furthermore, following c-Jun overexpression, survival rates of NP cells were increased while apoptosis rates were decreased. However, the addition of a TGF-β antibody significantly promoted apoptosis and restricted cell survival, which differed from the results of the c-Jun overexpression group. The present study hypothesized therefore that c-Jun may positively regulate TGF-β expression within NP cells of IDD, which could promote the proliferation of IDD-NP cells and accelerate cell viability via reducing apoptosis and the inflammatory response.

Rational modification, synthesis and biological evaluation of 3,4-dihydroquinoxalin-2(1H)-one derivatives as potent and selective c-Jun N-terminal kinase 3 (JNK3) inhibitors

The c-Jun N-terminal kinase 3 (JNK3) plays key roles in a wide range of diseases, including neurodegeneration diseases, inflammation diseases, cancers, cardiovascular diseases, and metabolic disorders. Previously, we have identified a lead compound, (Z)-3-(2-(naphthalen-1-yl)-2-oxoethylidene)-3,4-dihydroquinoxalin-2(1H)-one (J46), which contains a 3,4-dihydroquinoxalin-2(1H)-one core structure as a key fragment to inhibit JNK3. However, compound J46 displayed high DDR1 and EGFR (T790M, L858R) inhibition and poor physicochemical properties, especially clogD and water-solubility, in its biological studies. Herein, we optimized compound J46 by structure-based drug design and exploiting the selectivity and physicochemical properties of various warhead groups to obtain compound J46-37, which not only exhibited a potent inhibition against JNK3 but also showed more than 50-fold potency better than DDR1 and EGFR (T790M, L858R). Furthermore, the selectivity and structure-activity relationship of novel synthesized 3,4-dihydroquinoxalin-2(1H)-one derivatives were analyzed by molecular docking and molecular dynamics simulation. Overall, compound J46-37, as a highly selective inhibitor of JNK3 with well physicochemical properties, is worth developing as therapies for the treatment of diseases related to JNK3.

A Driver Never Works Alone-Interplay Networks of Mutant p53, MYC, RAS, and Other Universal Oncogenic Drivers in Human Cancer

The knowledge accumulating on the occurrence and mechanisms of the activation of oncogenes in human neoplasia necessitates an increasingly detailed understanding of their systemic interactions. None of the known oncogenic drivers work in isolation from the other oncogenic pathways. The cooperation between these pathways is an indispensable element of a multistep carcinogenesis, which apart from inactivation of tumor suppressors, always includes the activation of two or more proto-oncogenes. In this review we focus on representative examples of the interaction of major oncogenic drivers with one another. The drivers are selected according to the following criteria: (1) the highest frequency of known activation in human neoplasia (by mutations or otherwise), (2) activation in a wide range of neoplasia types (universality) and (3) as a part of a distinguishable pathway, (4) being a known cause of phenotypic addiction of neoplastic cells and thus a promising therapeutic target. Each of these universal oncogenic factors—mutant p53, KRAS and CMYC proteins, telomerase ribonucleoprotein, proteasome machinery, HSP molecular chaperones, NF-κB and WNT pathways, AP-1 and YAP/TAZ transcription factors and non-coding RNAs—has a vast network of molecular interrelations and common partners. Understanding this network allows for the hunt for novel therapeutic targets and protocols to counteract drug resistance in a clinical neoplasia treatment.

Protein kinases: master regulators of neuritogenesis and therapeutic targets for axon regeneration

Proper neurite formation is essential for appropriate neuronal morphology to develop and defects at this early foundational stage have serious implications for overall neuronal function. Neuritogenesis is tightly regulated by various signaling mechanisms that control the timing and placement of neurite initiation, as well as the various processes necessary for neurite elongation to occur. Kinases are integral components of these regulatory pathways that control the activation and inactivation of their targets. This review provides a comprehensive summary of the kinases that are notably involved in regulating neurite formation, which is a complex process that involves cytoskeletal rearrangements, addition of plasma membrane to increase neuronal surface area, coupling of cytoskeleton/plasma membrane, metabolic regulation, and regulation of neuronal differentiation. Since kinases are key regulators of these functions during neuromorphogenesis, they have high potential for use as therapeutic targets for axon regeneration after injury or disease where neurite formation is disrupted.

Colorectal cancer (CRC) as a multifactorial disease and its causal correlations with multiple signaling pathways

Colorectal cancer (CRC) is the third most common malignancy and one of the leading causes of cancer-related death among men worldwide. CRC is a multifactor digestive pathology, which is a huge problem faced not only by clinicians but also by researchers. Importantly, a unique feature of CRC is the dysregulation of molecular signaling pathways. To date, a series of reviews have indicated that different signaling pathways are disordered and have potential as therapeutic targets in CRC. Nevertheless, an overview of the function and interaction of multiple signaling pathways in CRC is needed. Therefore, we summarized the pathways, biological functions and important interactions involved in CRC. First, we investigated the involvement of signaling pathways, including Wnt, PI3K/Akt, Hedgehog, ErbB, RHOA, Notch, BMP, Hippo, AMPK, NF-κB, MAPK and JNK. Subsequently, we discussed the biological function of these pathways in pathophysiological aspects of CRC, such as proliferation, apoptosis and metastasis. Finally, we summarized important interactions among these pathways in CRC. We believe that the interaction of these pathways could provide new strategies for the treatment of CRC.

Cell Death and Neurodegeneration

Neurodegenerative disease is characterized by the progressive deterioration of neuronal function caused by the degeneration of synapses, axons, and ultimately the death of nerve cells. An increased understanding of the mechanisms underlying altered cellular homeostasis and neurodegeneration is critical to the development of effective treatments for disease. Here, we review what is known about neuronal cell death and how it relates to our understanding of neurodegenerative disease pathology. First, we discuss prominent molecular signaling pathways that drive neuronal loss, and highlight the upstream cell biology underlying their activation. We then address how neuronal death may occur during disease in response to neuron intrinsic and extrinsic stressors. An improved understanding of the molecular mechanisms underlying neuronal dysfunction and cell death will open up avenues for clinical intervention in a field lacking disease-modifying treatments.

Crosstalk between NLRP12 and JNK during Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), a leading cause of cancer-related death, is initiated and promoted by chronic inflammation. Inflammatory mediators are transcriptionally regulated by several inflammatory signaling pathways, including nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK). cJun N-terminal kinase (JNK), a member of the MAPK family, plays a central role in HCC pathogenesis. Pathogen-associated molecular patterns (PAMPs) activate JNK and other MAPK upon recognition by toll-like receptors (TLRs). Apart from TLRs, PAMPs are sensed by several other pattern recognition receptors, including cytosolic NOD-like receptors (NLRs). In a recent study, we demonstrated that the NLR member NLRP12 plays a critical role in suppressing HCC via negative regulation of the JNK pathway. This article briefly reviews the crosstalk between NLRP12 and JNK that occurs during HCC.

TRPV6 as A Target for Cancer Therapy

Two decades ago a class of ion channels, hitherto unsuspected, was discovered. In mammals these Transient Receptor Potential channels (TRPs) have not only expanded in number (to 26 functional channels) but also expanded the view of our interface with the physical and chemical environment. Some are heat and cold sensors while others monitor endogenous and/or exogenous chemical signals. Some TRP channels monitor osmotic potential, and others measure cell movement, stretching, and fluid flow. Many TRP channels are major players in nociception and integration of pain signals. One member of the vanilloid sub-family of channels is TRPV6. This channel is highly selective for divalent cations, particularly calcium, and plays a part in general whole-body calcium homeostasis, capturing calcium in the gut from the diet. TRPV6 can be greatly elevated in a number of cancers deriving from epithelia and considerable study has been made of its role in the cancer phenotype where calcium control is dysfunctional. This review compiles and updates recent published work on TRPV6 as a promising drug target in a number of cancers including those afflicting breast, ovarian, prostate and pancreatic tissues.

JNK-Dependent cJun Phosphorylation Mitigates TGFβ- and EGF-Induced Pre-Malignant Breast Cancer Cell Invasion by Suppressing AP-1-Mediated Transcriptional Responses

Transforming growth factor-β (TGFβ) has both tumor-suppressive and tumor-promoting effects in breast cancer. These functions are partly mediated through Smads, intracellular transcriptional effectors of TGFβ. Smads form complexes with other DNA-binding transcription factors to elicit cell-type-dependent responses. Previously, we found that the collagen invasion and migration of pre-malignant breast cancer cells in response to TGFβ and epidermal growth factor (EGF) critically depend on multiple Jun and Fos components of the activator protein (AP)-1 transcription factor complex. Here we report that the same process is negatively regulated by Jun N-terminal kinase (JNK)-dependent cJun phosphorylation. This was demonstrated by analysis of phospho-deficient, phospho-mimicking, and dimer-specific cJun mutants, and experiments employing a mutant version of the phosphatase MKP1 that specifically inhibits JNK. Hyper-phosphorylation of cJun by JNK strongly inhibited its ability to induce several Jun/Fos-regulated genes and to promote migration and invasion. These results show that MEK-AP-1 and JNK-phospho-cJun exhibit distinct pro- and anti-invasive functions, respectively, through differential regulation of Smad- and AP-1-dependent TGFβ target genes. Our findings are of importance for personalized cancer therapy, such as for patients suffering from specific types of breast tumors with activated EGF receptor-Ras or inactivated JNK pathways.

Claudin-2: Roles beyond Permeability Functions

Claudin-2 is expressed in the tight junctions of leaky epithelia, where it forms cation-selective and water permeable paracellular channels. Its abundance is under fine control by a complex signaling network that affects both its synthesis and turnover in response to various environmental inputs. Claudin-2 expression is dysregulated in many pathologies including cancer, inflammation, and fibrosis. Claudin-2 has a key role in energy-efficient ion and water transport in the proximal tubules of the kidneys and in the gut. Importantly, strong evidence now also supports a role for this protein as a modulator of vital cellular events relevant to diseases. Signaling pathways that are overactivated in diseases can alter claudin-2 expression, and a good correlation exists between disease stage and claudin-2 abundance. Further, loss- and gain-of-function studies showed that primary changes in claudin-2 expression impact vital cellular processes such as proliferation, migration, and cell fate determination. These effects appear to be mediated by alterations in key signaling pathways. The specific mechanisms linking claudin-2 to these changes remain poorly understood, but adapters binding to the intracellular portion of claudin-2 may play a key role. Thus, dysregulation of claudin-2 may contribute to the generation, maintenance, and/or progression of diseases through both permeability-dependent and -independent mechanisms. The aim of this review is to provide an overview of the properties, regulation, and functions of claudin-2, with a special emphasis on its signal-modulating effects and possible role in diseases.

Bridging the Gap Between Diabetes and Stroke in Search of High Clinical Relevance Therapeutic Targets

Diabetes affects more than 425 million people worldwide, a scale approaching pandemic proportion. Diabetes represents a major risk factor for stroke, and therefore is actively addressed for stroke prevention. However, how diabetes affects stroke severity has not yet been extensively considered, which is surprising given the evident but understudied common mechanistic features of both pathologies. The increase in number of diabetic people, incidence of stroke in the presence of this specific risk factor, and the exacerbation of ischemic brain damage in diabetic conditions (at least in animal models) warrants the need to integrate this comorbidity in preclinical studies of brain ischemia to develop novel therapeutic approaches. Therefore, a better understanding of the commonalties involved in the course of both diseases would offer the promise of discovering novel neuroprotective pathways that would be more appropriated to clinical scenarios. In this article, we will review the relevant mechanisms that have been identified as common traits of both pathologies and that could be, to our knowledge, potential targets in both pathologies.

CDC25A Facilitates Chemo-resistance in Ovarian Cancer Multicellular Spheroids by Promoting E-cadherin Expression and Arresting Cell Cycles

Peritoneal metastasis is the most common pathway for the spread of ovarian cancer and one of the major causes of cancer death. Ovarian cancer cells in ascites prefer to aggregate into the multicellular spheroids (MCS) with an inadequate response to chemotherapy. In this study, gene expression analysis implicated that ovarian cancer MCS had its unique expression pattern and the cell cycle-related pathways were prominently altered in MCS cells compared to the monolayer adherent cells. Flow cytometry and western blots confirmed the cell cycle stagnancy in MCS. Among the cell cycle-related proteins, we found that expression of CDC25A was upregulated in MCS and displayed a time-dependent decrease during the transition from MCS to monolayer adherent cells. Loss-of-function studies showed that CDC25A promoted cisplatin-resistance and paclitaxel-resistance and inhibited the drug-induced apoptosis in ovarian cancer MCS. Mechanically, CDC25A impeded cell cycle progression in MCS cells, enhanced their structure integrity, and maintained upregulation of E-cadherin in MCS cells. Accordingly, addition of NSC95397, a small molecular inhibitor of CDC25A, sensitized the ovarian cancer MCS to chemotherapeutic agents. This provides us a novel strategy for the treatment of ovarian cancer peritoneal metastasis and may help improve the overall survival of ovarian cancer patients.

Transcriptional profiling of macrophages infected with Fonsecaea monophora

Fonsecaea monophora is a member of dematiaceous fungi capable of causing chromoblastomycosis through traumatic injury. However, little is known about the pathogenesis and early interactions between F. monophora and host. The aim of this study was to explore the potential mechanism of macrophages against F. monophora, especially the role of melanin during the pathogenic process. We carried out RNA sequencing based on the Illumina system. It showed that according to melanin contents, different strains of F. monophora induced different transcriptional profilings in macrophages. Functional analyses suggested the biological functions of differentially expressed genes were closely related to immune response, and the melanin might affect the interactions by regulating the MAPK signalling pathway of macrophages. Our results provide insights into the pathogenesis of infection by F. monophora conidia.

Acute immune stress improves cell resistance to chemical poison damage in SP600125-induced polyploidy of fish cells in vitro

Previous research has indicated that the small compound, SP600125, could induce polyploidy of fish cells, and has established a stable tetraploid cell line from diploid fish cells. In order to explore how fish cells maintain homeostasis under SP600125-stress in vitro, this study investigates impacts of SP600125-stress on intracellular pathways, as well as on regulation of the cellular homeostasis feedback in fish cells. Transcriptomes are obtained from the SP600125-treated cells. Compared with unigenes expressed in control group (crucial carp fin cells), a total of 2670 and 1846 unigenes are significantly upregulated and downregulated in these cells, respectively. Differentially expressed genes are found, which are involved in innate defense, inflammatory pathways and cell adhesion molecules-related pathways. The SP600125-stress enhances cell-mediated immunity, characterized by significantly increasing expression of multiple immune genes. These enhanced immune genes include the pro-inflammatory cytokines (IL-1β, TNF-ɑ, IL-6R), the adaptor signal transducers (STAT, IκBɑ), and the integrins (ɑ2β1, ɑMβ2). Furthermore, mitochondria are contributed to the cellular homeostasis regulation upon the SP600125-stress. The results show that acute inflammation is an adaptive and controlled response to the SP600125-stress, which is beneficial for alleviating toxicity by SP600125. They provide a potential way of breeding fish polyploidy induced by SP600125 in the future research.

MAPK and PI3K signaling: At the crossroads of neural crest development

Receptor tyrosine kinase-mediated growth factor signaling is essential for proper formation and development of the neural crest. The many ligands and receptors implicated in these processes signal through relatively few downstream pathways, frequently converging on the MAPK and PI3K pathways. Despite decades of study, there is still considerable uncertainty about where and when these signaling pathways are required and how they elicit particular responses. This review summarizes our current understanding of growth factor-induced MAPK and PI3K signaling in the neural crest.