Functions of JNK stresskinases in neuronal apoptosis and differentiation

The c-Jun N-terminal kinases (JNKs), a subfamily of the mitogen-activated protein kinases (MAPKs), are considered as essential signalling molecules for neurodegeneration in the mammalian brain. However, they also have physiological functions such as in development, differentiation, proliferation and neuroregeneration. The aims of the present study were to determine the physiological and pathological roles of JNK isoforms in PC12 cells and in primary neurons. 6-OHDA enhanced total JNK activity in the cytoplasm, nucleus and at the mitochondria in PC12 cells. Inhibition of JNKs by SP600125 or transfection with dominant negative JNK2 (dnJNK2) but not dnJNK1, substantially attenuated 6-OHDA-induced cell death. JNK2 translocated into the nucleus and mitochondria following 6-OHDA and mediates cytochrome c release and caspase-3 activation. In primary neurons JNKs also mediate death. Glutamate and 6-OHDA induced death and caspase-3 activation in primary hippocampal and cortical neurons, respectively. Inhibition of JNKs with SP600125 rescued these otherwise dying cells and inhibited caspase-3 activation, indicating JNK-mediated death. Besides neurodegenerative and pro-apoptotic functions, the family of JNKs has also been implicated in neuronal differentiation and development. Therefore the role of JNKs in neuronal differentiation were also analysed in this study. Inhibition of JNKs by SP600125 prevented neurite elongation in primary hippocampal neurons. These results provide evidence that JNKs have apoptotic effects after an excitotoxic stimulus but in parallel to their apoptotic effects they have also physiological functions on neurite formation and elongation in vitro during neuritogenesis

Metabolism within the tumor microenvironment and its implication on cancer progression: an ongoing therapeutic target

Since reprogramming energy metabolism is considered a new hallmark of cancer, tumor metabolism is again in the spotlight of cancer research. Many studies have been carried out and many possible therapies have been developed in the last years. However, tumor cells are not alone. A series of extracellular components and stromal cells, such as endothelial cells, cancer-associated fibroblasts, tumor-associated macrophages and tumor-infiltrating T cells, surround tumor cells in the so-called tumor microenvironment. Metabolic features of these cells are being studied in deep in order to find relationships between metabolism within the tumor microenvironment and tumor progression. Moreover, it cannot be forgotten that tumor growth is able to modulate host metabolism and homeostasis, so that tumor microenvironment is not the whole story. Importantly, the metabolic switch in cancer is just a consequence of the flexibility and adaptability of metabolism and should not be surprising. Treatments of cancer patients with combined therapies including anti-tumor agents with those targeting stromal cell metabolism, anti-angiogenic drugs and/or immunotherapy are being developed as promising therapeutics.Mª Carmen Ocaña is recipient of a predoctoral FPU grant from the Spanish Ministry of Education, Culture and Sport. Supported by grants BIO2014-56092-R (MINECO and FEDER), P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript

JNK Isoforms Differentially Regulate Neurite Growth and Regeneration in Dopaminergic Neurons In Vitro

Parkinson’s disease is characterized by selective and progressive loss of midbrain DAergic neurons (MDN) in the substantia nigra and degeneration of its nigrostriatal projections. Whereas the cellular pathophysiology has been closely linked to an activation of c-Jun N-terminal kinases (JNKs) and c-Jun, the involvement of JNKs in regenerative processes of the nigrostriatal pathway is controversially discussed. In our study, we utilized a mechanical scratch lesion paradigm of midbrain DAergic neurons in vitro and studied regenerative neuritic outgrowth. After a siRNA-mediated knockdown of each of the three JNK isoforms, we found that JNKs differentially regulate neurite regeneration. Knockdown of JNK3 resulted in the most prominent neurite outgrowth impairment. This effect was attenuated again by plasmid overexpression of JNK3. We also evaluated cell survival of the affected neurons at the scratch border. JNK3 was found to be also relevant for survival of MDN which were lesioned by the scratch. Our data suggest that JNK isoforms are involved in differential regulation of cell death and regeneration in MDN depending on their neurite integrity. JNK3 appears to be required for regeneration and survival in the case of an environment permissive for regeneration. Future therapeutic approaches for the DAergic system may thus require isoform specific targeting of these kinases

Modulation of Interleukin-1 Transcriptional Response by the Interaction between VRK2 and the JIP1 Scaffold Protein

Background. Cellular biological responses to specific stimulation are determined by a balance among signaling pathways. Protein interactions are likely to modulate these pathways. Vaccinia-related kinase-2 (VRK2) is a novel human kinase that can modulate different signaling pathways. Principal findings. We report that in vivo, the activity of JIP1-JNK complexes is downregulated by VRK2 in response to interleukin-1β. Also the reduction of endogenous VRK2 with shRNA increases the transcriptional response to IL-1β. The JIP1 scaffold protein assembles three consecutive members of a given MAPK pathway forming signaling complexes and their signal can be modulated by interactions with regulatory proteins that remain to be identified. Knocking-down JIP1 with siRNA resulted in elimination of the AP1 transcriptional response to IL-1β. VRK2, a member of novel Ser-Thr kinase family, is able to stably interact with JIP1, TAK1 and MKK7, but not JNK, and can be isolated forming oligomeric complexes with different proportions of TAK1, MKK7β1 and JNK. JIP1 assembles all these proteins in an oligomeric signalosome. VRK2 binding to the JIP1 signalosome prevents the association of JNK and results in a reduction in its phosphorylation and downregulation of AP1-dependent transcription. Conclusions/Significance. This work suggests that the intracellular level of VRK2 protein can modulate the flow through a signaling pathway and alter the response from a receptor that can be distributed by more than one pathway, and thus contribute to the cellular specificity of the response by forming alternative signaling complexes. Furthermore, the effect might be more general and affect other signaling routes assembled on the JIP1 scaffold protein for which a model is proposed.S.B., M. S-G, and C.R.S. have predoctoral fellowships from Ministerio de Educación y Ciencia, CSIC (Spain) and Fundação para a Ciência e a Tecnologia (Portugal) respectively. This work was funded by grants from Ministerio de Educación y Ciencia (SAF2004-02900, SAF2007-60242 and Consolider CSD-2007-0017), Fundación de Investigación Médica MM and Federación de Cajas de Ahorro de Castilla y León to P.A.L.Peer reviewe

Transcription factor NRF2 as a therapeutic target for chronic diseases: a systems medicine approach

Systems medicine has a mechanism-based rather than a symptom- or organ-based approach to disease and identifies therapeutic targets in a nonhypothesis-driven manner. In this work, we apply this to transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) by cross-validating its position in a protein-protein interaction network (the NRF2 interactome) functionally linked to cytoprotection in low-grade stress, chronic inflammation, metabolic alterations, and reactive oxygen species formation. Multiscale network analysis of these molecular profiles suggests alterations of NRF2 expression and activity as a common mechanism in a subnetwork of diseases (the NRF2 diseasome). This network joins apparently heterogeneous phenotypes such as autoimmune, respiratory, digestive, cardiovascular, metabolic, and neurodegenerative diseases, along with cancer. Importantly, this approach matches and confirms in silico several applications for NRF2-modulating drugs validated in vivo at different phases of clinical development. Pharmacologically, their profile is as diverse as electrophilic dimethyl fumarate, synthetic triterpenoids like bardoxolone methyl and sulforaphane, protein-protein or DNA-protein interaction inhibitors, and even registered drugs such as metformin and statins, which activate NRF2 and may be repurposed for indications within the NRF2 cluster of disease phenotypes. Thus, NRF2 represents one of the first targets fully embraced by classic and systems medicine approaches to facilitate both drug development and drug repurposing by focusing on a set of disease phenotypes that appear to be mechanistically linked. The resulting NRF2 drugome may therefore rapidly advance several surprising clinical options for this subset of chronic diseases

The JNK Inhibitor XG-102 Protects against TNBS-Induced Colitis

The c-Jun N-terminal kinase (JNK)-inhibiting peptide D-JNKI-1, syn. XG-102 was tested for its therapeutic potential in acute inflammatory bowel disease (IBD) in mice. Rectal instillation of the chemical irritant trinitrobenzene sulfonic acid (TNBS) provoked a dramatic acute inflammation in the colon of 7–9 weeks old mice. Coincident subcutaneous application of 100 µg/kg XG-102 significantly reduced the loss of body weight, rectal bleeding and diarrhoea. After 72 h, the end of the study, the colon was removed and immuno-histochemically analysed. XG-102 significantly reduced (i) pathological changes such as ulceration or crypt deformation, (ii) immune cell pathology such as infiltration and presence of CD3- and CD68-positive cells, (iii) the production of tumor necrosis factor (TNF)-α in colon tissue cultures from TNBS-treated mice, (iv) expression of Bim, Bax, FasL, p53, and activation of caspase 3, (v) complexation of JNK2 and Bim, and (vi) expression and activation of the JNK substrate and transcription factor c-Jun. A single application of subcutaneous XG-102 was at least as effective or even better depending on the outcome parameter as the daily oral application of sulfasalazine used for treatment of IBD

Women, Water Resource Management, and Sustainable Development: The Turkey-North Cyprus Water Pipeline Project

Women’s role in water resource management is recognized, yet the implementation of methods and strategies to get beyond gender-based obstacles to women’s equal participation in water resource management related projects remain vague. Mainstream considerations on the gender aspects of development and environment focus on women as having an intrinsic relationship with the environment. Women are perceived as a natural reflection of their responsibilities for the household and the comfort and security of future generations. Contrary to mainstream environmental and political ecology research, this paper sees gender as relevant within policy and practice across multiple levels, and within institutions related to natural resource governance. Based on this, the paper looks at the sustainable development and water governance issues with the help of a specific case: the Turkey-North Cyprus Water Pipeline Project. Through broad reviews of project documentation, interviews with people who were directly involved with the project and with women’s organizations the paper draws insights on the gender aspect of the decision-making mechanisms related to water governance. The results indicate that participation by women in resource management is marginal in North Cyprus. The paper discusses that this is a reflection of a broader problem, which is gender inequality. In conclusion, one can argue that future water projects need to realize more sustainable outcomes and greater effects on gender equality in North Cyprus

Kıbrıs hidrokarbon tartışmasının Kıbrıs problemi ile ilişkili olarak politik bağlamının incelenmesi.

The discovery of new energy sources around Cyprus has created an interest in questioning the role of these resources; whether they will promote peace or exacerbate the existing tensions in the region. On that axis where energy and politics intersect, the Cyprus problem now holds a significant energy dimension which deserves to be explored carefully. With this understanding, this thesis is exploring Cyprus hydrocarbons issue by looking at energy related developments and related parties policies towards eastern Mediterranean on energy issues and the ways in which these policies are related to the Cyprus problem. The aim is to understand what the recent hydrocarbon related developments tell us about the geopolitics of energy in eastern Mediterranean and the dynamics of the Cyprus problem within that new geopolitical reality. This thesis maintains the significance of examining the contexts in which hydrocarbons debate emerge in Cyprus. It eventually argues that viewing the link between the Cyprus problem and the Cyprus hydrocarbons issue requires looking at sovereignty and territoriality dimensions of the conflict in Cyprus. The positions of Turkey, the RoC and TRNC, and the international community towards the oil and gas efforts around Cyprus reveal the predominance of these concepts in shaping the course of the energy developments in the region. In terms of whether the findings will excarbete the existing conflict in Cyprus or will create the grounds for cooperation; this thesis noticed that analysed arguments and positions on Cyprus hydrocarbons debate almost completely overlap with related actors‘ existing conflictual positions.Ph.D. - Doctoral Progra