Increase in the prevalence of the MTHFR 677 TT polymorphism in women born since 1959: potential implications for folate requirements

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Tackling dipeptidyl peptidase IV in neurological disorders

© 2018, Medknow Publications. All rights reserved. Dipeptidyl peptidase IV (DPP-IV) is a serine protease best known for its role in inactivating glucagon-like peptide-1 (GLP-1), pituitary adenylate cyclase-activating polypeptide (PACAP) and glucose-dependent insulinotropic peptide (GIP), three stimulators of pancreatic insulin secretion with beneficial effects on glucose disposal. Owing to the relationship between DPP-IV and these peptides, inhibition of DPP-IV enzyme activity is considered as an attractive treatment option for diabetic patients. Nonetheless, increasing studies support the idea that DPP-IV might also be involved in the development of neurological disorders with a neuroinflammatory component, potentially through its non-incretin activities on immune cells. In this review article, we aim at highlighting recent literature describing the therapeutic value of DPP-IV inhibitors for the treatment of such neurological conditions. Finally, we will illustrate some of the promising results obtained using berberine, a plant extract with potent inhibitory activity on DPP-IV

Identification of dysregulated microRNA networks in schwann cell-like cultures exposed to immune challenge: Potential crosstalk with the protective VIP/PACAP neuropeptide system

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Following peripheral nerve injury, dysregulations of certain non-coding microRNAs (miRNAs) occur in Schwann cells. Whether these alterations are the result of local inflammation and/or correlate with perturbations in the expression profile of the protective vasoactive intestinal peptide (VIP)/pituitary adenylate cyclase-activating polypeptide (PACAP) system is currently unknown. To address these issues, we aimed at profiling the expression of selected miRNAs in the rat RT4 Schwann cell line. Cells exposed to lipopolysaccharide (LPS), to mimic the local inflammatory milieu, were appraised by real-time qPCR, Western blot and ELISAs. We found that upon LPS treatment, levels of pro-inflammatory cytokines (IL-1β, -6, -18, -17A, MCP-1 and TNFα) increased in a time-dependent manner. Unexpectedly, the expression levels of VIP and PACAP were also increased. Conversely, levels of VPAC1 and VPAC2 receptors were reduced. Downregulated miRNAs included miR-181b, -145, -27a, -340 and -132 whereas upregulated ones were miR-21, -206, -146a, -34a, -155, -204 and -29a, respectively. Regression analyses revealed that a subset of the identified miRNAs inversely correlated with the expression of VPAC1 and VPAC2 receptors. In conclusion, these findings identified a novel subset of miRNAs that are dysregulated by immune challenge whose activities might elicit a regulatory function on the VIP/PACAP system

Ameliorative effects of PACAP against cartilage degeneration. Morphological, immunohistochemical and biochemical evidence from in vivo and in vitro models of rat osteoarthritis

© 2015 by the authors; licensee MDPI, Basel, Switzerland. Osteoarthritis (OA); the most common form of degenerative joint disease, is associated with variations in pro-inflammatory growth factor levels, inflammation and hypocellularity resulting from chondrocyte apoptosis. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide endowed with a range of trophic effects in several cell types; including chondrocytes. However; its role in OA has not been studied. To address this issue, we investigated whether PACAP expression is affected in OA cartilage obtained from experimentally-induced OA rat models, and then studied the effects of PACAP in isolated chondrocytes exposed to IL-1β in vitro to mimic the inflammatory milieu of OA cartilage. OA induction was established by histomorphometric and histochemical analyses. Changes in PACAP distribution in cartilage, or its concentration in synovial fluid (SF), were assessed by immunohistochemistry and ELISA. Results showed that PACAP abundance in cartilage tissue and SF was high in healthy controls. OA induction decreased PACAP levels both in affected cartilage and SF. In vitro, PACAP prevented IL-1β-induced chondrocyte apoptosis, as determined by MTT assay; Hoechst staining and western blots of apoptotic-related proteins. These changes were also accompanied by decreased i-NOS and COX-2 levels, suggesting an anti-inflammatory effect. Altogether, these findings support a potential role for PACAP as a chondroprotective agent for the treatment of OA

Dual role of autophagy on docetaxel-sensitivity in prostate cancer cells

Prostate cancer (PC) is one of the leading causes of death in males. Available treatments often lead to the appearance of chemoresistant foci and metastases, with mechanisms still partially unknown. Within tumour mass, autophagy may promote cell survival by enhancing cancer cells tolerability to different cell stresses, like hypoxia, starvation or those triggered by chemotherapic agents. Because of its connection with the apoptotic pathways, autophagy has been differentially implicated, either as prodeath or prosurvival factor, in the appearance of more aggressive tumours. Here, in three PC cells (LNCaP, PC3, and DU145), we tested how different autophagy inducers modulate docetaxel-induced apoptosis. We selected the mTOR-independent disaccharide trehalose and the mTOR-dependent macrolide lactone rapamycin autophagy inducers. In castration-resistant PC (CRPC) PC3 cells, trehalose specifically prevented intrinsic apoptosis in docetaxel-treated cells. Trehalose reduced the release of cytochrome c triggered by docetaxel and the formation of aberrant mitochondria, possibly by enhancing the turnover of damaged mitochondria via autophagy (mitophagy). In fact, trehalose increased LC3 and p62 expression, LC3-II and p62 (p62 bodies) accumulation and the induction of LC3 puncta. In docetaxel-treated cells, trehalose, but not rapamycin, determined a perinuclear mitochondrial aggregation (mito-aggresomes), and mitochondria specifically colocalized with LC3 and p62-positive autophagosomes. In PC3 cells, rapamycin retained its ability to activate autophagy without evidences of mitophagy even in presence of docetaxel. Interestingly, these results were replicated in LNCaP cells, whereas trehalose and rapamycin did not modify the response to docetaxel in the ATG5-deficient (autophagy resistant) DU145 cells. Therefore, autophagy is involved to alter the response to chemotherapy in combination therapies and the response may be influenced by the different autophagic pathways utilized and by the type of cancer cells

PO-078 Role of the ER stress-autophagy axis and mitochondrial metabolism reprogramming in the apoptosis induced by δ-TOCOTRIENOL in prostate cancer

Introduction Castration resistant prostate cancer (CRPC) is an aggressive tumour with still limited therapeutic outcomes. Tocotrienols (TT), vitamin E derivatives, were reported to exert anticancer activity in different tumours. The aim of this study was to assess the effects of δ-TT on human CRPC cells growth and the molecular mechanisms associated with its activity. Material and methods In human normal prostate (RWPE-1) and CRPC (PC3 and DU145) cell lines the effect of δ-TT on cell viability was evaluated by MTT assay; in PC3 and DU145 cells Trypan blue exclusion and colony formation assays were also performed. The expression of apoptosis-, ER stress- and autophagy-related proteins was analysed by Western blot and immunofluorescence assays, and the cytotoxic effect of δ-TT was also assessed using specific inhibitors of these pathways. The effect on mitochondrial metabolism was evaluated analysing the expression of the OXPHOS complexes (Western blot), the mitochondrial activity and mass (flow cytometry), the oxygen consumption (Clark-type oxygen electrode) and the ATP production (colorimetric assay). Results and discussions We demonstrated that δ-TT exerts a cytotoxic effect on PC3 and DU145 but not on RWPE-1 cells. In particular, δ-TT induces caspase 3 and PARP cleavage and cytochrome c release from mitochondria, and its cytotoxic effect is partially blocked by co-treatment with the pan-caspase inhibitor z-VAD-FMK, confirming that δ-TT exerts a pro-apoptotic effect on CRPC cells. We also observed that δ-TT significantly increases the expression of ER stress (BiP, IRE1α, PERK, pEIF2α, ATF4 and CHOP) and autophagy mediators (LC3-II and p62). Using the ER stress inhibitors salubrinal and 4-phenylbutyrate (4-PBA) and the autophagic flux inhibitors 3-methyladenine and chloroquine, we confirmed that the effect of δ-TT is mediated by both these mechanisms. In addition, treatment with salubrinal or 4-PBA impairs δ-TT-induced LC3-II expression, demonstrating that this compound triggers the ER stress-autophagy axis. Finally, we observed that δ-TT severely alters mitochondrial metabolism: the expression of the OXPHOS protein complexes, the mitochondrial activity/mass ratio, the oxygen consumption and the ATP production were significantly reduced after δ-TT treatment. Conclusion These results demonstrate that δ-TT exerts a selective pro-apoptotic effect on human CRPC cells through the activation of the ER stress-autophagy axis and the rewiring of mitochondrial metabolism

Vitamin E δ-tocotrienol triggers endoplasmic reticulum stress-mediated apoptosis in human melanoma cells

Malignant melanoma is the leading cause of death from skin cancer. Drug toxicity and resistance represent a serious challange for melanoma treatments. Evidence demonstrates that natural compounds may play a crucial role in cancer prevention, growth and progression. Vitamin E tocotrienols (TT) were shown to possess antitumor activity. Here, we analyzed the effects of \u3b4-TT on melanoma cell growth and the involvement of the endoplasmic reticulum (ER) stress in this activity. The experiments were performed on human melanoma cell lines, BLM and A375. \u3b4-TT exerted a significant proapoptotic effect on both cell lines, involving the intrinsic apoptosis pathway; importantly, this compound did not affect the viability of normal human melanocytes. In melanoma cells, \u3b4-TT exerted its antitumor effect through activation of the PERK/p-eIF2\u3b1/ATF4/CHOP, IRE1\u3b1 and caspase-4 ER stress-related branches. Salubrinal, an inhibitor of the ER stress, counteracted the cytotoxic activity of \u3b4-TT. In vivo experiments performed in nude mice bearing A375 xenografts evidenced that \u3b4-TT reduces tumor volume and tumor mass; importantly, tumor progression was significantly delayed by \u3b4-TT treatment. In conclusion, \u3b4-TT exerts a proapoptotic activity on melanoma cells, through activation of the ER stress-related pathways. \u3b4-TT might represent an effective option for novel chemopreventive/therapeutic strategies for melanoma

Fear expression is suppressed by tyrosine administration

Animal studies have demonstrated that catecholamines regulate several aspects of fear conditioning. In humans, however, pharmacological manipulations of the catecholaminergic system have been scarce, and their primary focus has been to interfering with catecholaminergic activity after fear acquisition or expression had taken place, using L-Dopa, primarily, as catecholaminergic precursor. Here, we sought to determine if putative increases in presynaptic dopamine and norepinephrine by tyrosine administered before conditioning could affect fear expression. Electrodermal activity (EDA) of 46 healthy participants (24 placebo, 22 tyrosine) was measured in a fear instructed task. Results showed that tyrosine abolished fear expression compared to placebo. Importantly, tyrosine did not affect EDA responses to the aversive stimulus (UCS) or alter participants' mood. Therefore, the effect of tyrosine on fear expression cannot be attributed to these factors. Taken together, these findings provide evidence that the catecholaminergic system influences fear expression in humans

Private trade and monopoly structures : the East India Companies and the commodity trade to Europe in the eighteenth century

Our research is about the trade in material goods from Asia to Europe over this period, and its impact on Europe’s consumer and industrial cultures. It entails a comparative study of Europe’s East India Companies and the private trade from Asia over the period. The commodities trade was heavily dependent on private trade. The historiography to date has left a blind spot in this area, concentrating instead on corruption and malfeasance. Taking a global history approach we investigate the trade in specific consumer goods in many qualities and varieties that linked merchant communities and stimulated information flows. We set out how private trade functioned alongside and in connection with the various European East India companies; we investigate how this changed over time, how it drew on the Company infrastructure, and how it took the risks and developed new and niche markets for specific Asian commodities that the Companies could not sustain