The role of neuronal NLRP1 inflammasome in Alzheimer's disease : bringing neurons into the neuroinflammation game

The innate immune system and inflammatory response in the brain have critical impacts on the pathogenesis of many neurodegenerative diseases including Alzheimer’s disease (AD). In the central nervous system (CNS), the innate immune response is primarily mediated by microglia. However, non-glial cells such as neurons could also partake in inflammatory response independently through inflammasome signalling. The NLR family pyrin domain-containing 1 (NLRP1) inflammasome in the CNS is primarily expressed by pyramidal neurons and oligodendrocytes. NLRP1 is activated in response to amyloid-β (Aβ) aggregates, and its activation subsequently cleaves caspase-1 into its active subunits. The activated caspase-1 proteolytically processes interleukin-1β (IL-1β) and interleukin-18 (IL-18) into maturation whilst co-ordinately triggers caspase-6 which is responsible for apoptosis and axonal degeneration. In addition, caspase-1 activation induces pyroptosis, an inflammatory form of programmed cell death. Studies in murine AD models indicate that the Nlrp1 inflammasome is indeed upregulated in AD and neuronal death is observed leading to cognitive decline. However, the mechanism of NLRP1 inflammasome activation in AD is particularly elusive, given its structural and functional complexities. In this review, we examine the implications of the human NLRP1 inflammasome and its signalling pathways in driving neuroinflammation in AD

Agrobacterium-mediated gene delivery and transient expression in the red macroalga Chondrus crispus

Molecular resources and transgenic studies in red algae are lagging behind those for green algae. The Agrobacterium-mediated gene-transfer method routinely used in plant transformation has not been fully utilised in the red algae, which, as an important source of phycocolloids, warrant more studies. In this regard, a stepwise methodology was developed for Agrobacterium-mediated transformation of the carrageenophyte Chondrus crispus using pCAMBIA 1301 and a construct featuring a codon-optimized beta-glucuronidase (GUS) reporter gene driven by the endogenous Chondrus actin promoter. The effects of several factors on transformation efficiency were investigated. An intimate association of Chondrus and bacterial cells was observed using scanning electron microscopy. GUS transient expression within Chondrus cortical and medullary cells with both expression cassettes testified to the amenability of Chondrus to Agrobacterium-mediated transformation. Darker staining, indicative of higher GUS activity, was observed with the Chondrus-specific construct, suggesting its superiority over the pCAMBIA 1301. Presence of acetosyringone, the wounding method and the type of co-cultivation medium significantly affected the transformation outcome and efficiency. The Agrobacterium-mediated transient expression presented here constitutes a first step towards tailoring a transformation strategy for Chondrus, which can serve to facilitate further transgenic studies in this important red alga

Development of a transformation system for Gracilaria changii (Gracilariales, Rhodophyta), a Malaysian red alga via microparticle bombardment

Of the seaweed phycocolloids, agar has the higher price in the world market and is mostly extracted from red seaweeds. Critchley (1993) reported the world market value of agar as US $200 million. Hurtado-Ponce and Umezaki (1988) reported that the world's commercial agar comes mostly from gracilaroids

Interleukins, laminin and epstein - barr virus latent membrane protein 1 (EBV LMP1) Promote metastatic phenotype in nasopharyngeal carcinoma

<p>Abstract</p> <p>Background</p> <p>Nasopharyngeal carcinoma (NPC) is a type of neoplasm that is highly prevalent in East Asia and Africa with Epstein-Barr virus (EBV), genetic, and dietary factors implicated as possible aetiologic factors. Previous studies suggested the association of certain cytokines with the invasion and metastatic properties of NPC. The present study examined the roles of EBV latent membrane protein-1 (LMP1), interleukin-6 (IL-6), interleukin-10 (IL-10), transforming growth factor-beta 1 (TGF-β1) and laminin in the regulation of matrix-metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) in NPC. The effects of these factors on <it>bmi-1</it>, an oncogene, and <it>ngx6</it>, a tumour suppressor gene, were also investigated.</p> <p>Methods</p> <p>TW01 cells expressing LMP1 (TW01-LMP1) were established via transfection with the B95.8 EBV LMP1 gene. Both TW01 and TW01-LMP1 cells were treated with 100 pg/ml IL-6, 1000 pg/ml IL-10 and 100 pg/ml TGF-β1, separately and also in combination at their respective concentration for 48 hours. Treated cells were subjected to laminin adherence assay. The cells were also cultured with and without laminin and assayed for MMP-3, MMP-9 and VEGF production using enzyme-linked immunosorbent assay (ELISA). The cellular apoptotic property was analysed using caspase-3 apoptosis assay. The expression of <it>bmi-1 </it>and <it>ngx6 </it>gene was investigated using real time reverse transcriptase polymerase chain reaction.</p> <p>Results</p> <p>LMP1 was found to reduce the adherence of NPC cells towards laminin (p < 0.05) as compared to control. Treatment with IL-6 at 100 pg/ml enhanced the production of MMP-9 in both TW01 and TW01-LMP1 cells (p < 0.05). When cultured on laminin, the levels of MMP-3 and VEGF were significantly increased (p < 0.05) in TW01-LMP1 cells. TW01-LMP1 cells had relatively greater resistance to apoptosis as compared to TW01 cells (p < 0.05). Laminin, IL-6 and LMP1 were found to up-regulate the expression of <it>bmi-1 </it>and suppressed the expression of <it>ngx6</it>.</p> <p>Conclusions</p> <p>We conclude that IL-6 reduced cell adherence towards laminin and increased MMP-9 production in NPC cells. Our data suggested that EBV LMP1 was able to confer resistance of apoptosis and increased MMP-9 production in NPC cells. When cultured on laminin, TW01 cells expressing the EBV LMP1 (TW0-LMP1) that were treated with IL-6 at 100 pg/ml displayed increased MMP-9 production, up-regulation of <it>bmi-1 </it>oncogene expression and down-regulation of <it>ngx6 </it>tumour suppressor gene expression. These findings implicate the roles of EBV LMP1, laminin and IL-6 in the promotion of invasion and metastasis in NPC.</p

The Effect of Cytokines on MicroRNA Expression in TW01 Nasopharyngeal Carcinoma Cells

Aims: To determine the effect of cytokines, namely transforming growth factor-beta one (TGF-β1), and interleukin-6 (IL-6) on the expression of 88 cancer-related microRNAs (miRNAs) in TW01 nasopharyngeal carcinoma (NPC) cells with or without the presence of Epstein-Barr virus latent membrane protein 1 (LMP1). Methodology: TW01 and TW01-LMP1 cells were treated with cytokines. MicroRNAs were isolated from treated and untreated TW01/TW01-LMP1 cells and were subjected to RT-PCR array of 88 cancer-related microRNAs. The threshold cycle (Ct) data were analysed and fold-change in the level of gene expression was calculated based on ΔΔCt using two endogenous controls, SNORD 47 and SNORD 44. Data obtained from each treatment were compared with the data obtained from the respective control group (untreated TW01/ TW01-LMP1). Results: TGF-β1 down-regulated miR-143 in TW01 NPC cells. In TW01 cells that expressed the EBV LMP1 gene (TW01-LMP1), approximately 97% of the 88 miRNAs were up-regulated by TGF-β1. Among them was miR-181c a well-known repressor of NOTCH2/4 and KRAS and has important role in cell differentiation. IL-6 up-regulated approximately 65% of the miRNAs in TW01 cells but in less than four-fold. In TW0- LMP1 cells, eight miRNAs; namely, miR-15b, miR-155, miR-16, miR-215, miR-23b, miR-25, miR-9 and miR-98 were significantly up-regulated by IL-6. Among these, miR- 15b, miR-155 and miR-25 had been reported to be elevated in NPC tissues. Conclusion: This study provides a preliminary perspective on the effects of cytokines on the expression of miRNAs in TW01 NPC cells

Gene expression profile of marine Chlorella strains from different latitudes: stress and recovery under elevated temperatures

Global warming, as a consequence of climate change, poses a critical threat to marine life, including algae. Studies on algal response at the molecular level to temperature stress have been significantly improved by advances in omics technologies. Algae are known to employ various strategies in response to heat stress. For example, algae regulate starch synthesis to provide energy for the cell or rebuild the damaged subunits of photosystems to regain photosynthetic activity. The aim of the present study is to examine the expression of selected photosynthesis-related genes of marine Chlorella originating from different latitudes, in response to heat stress and during the recovery period. In this study, marine Chlorella strains from the Antarctic, temperate region, and the tropics were grown at their ambient and stress-inducing temperatures. The maximum quantum efficiency (F v /F m ) photosynthetic parameter was used to assess their stress levels. When subjected to heat stress, the F v /F m began to decline and when it reached ~ 0.2, the cultures were transferred to their respective ambient temperature for recovery. Total RNA was isolated from these cultures at F v /F m ~ 0.4, 0.2, and when it regained 0.4 during recovery. The expression of four genes including psbA, psaB, psbC, and rbcL was analyzed using RT-PCR. The housekeeping gene, histone subunit three (H3) was used for data normalization. Studying the genes involved in the adaptation mechanisms would enhance our knowledge on algal adaptation pathways and pave the way for genetic engineers to develop more tolerant strains

Genes associated with amyloid-beta-induced inflammasome-mediated neuronal death identified using functional gene trap mutagenesis approach

Alzheimer's disease is an irreversible neurodegenerative disease, which accounts for most dementia cases. Neuroinflammation is increasingly recognised for its roles in Alzheimer's disease pathogenesis which, in part, links amyloid-beta to neuronal death. Neuroinflammatory signalling can be exhibited by neurons themselves, potentially leading to widespread neuronal cell death, although neuroinflammation is commonly associated with glial cells. The presence of the inflammasomes such as nucleotide-binding leucine-rich repeat receptors protein 1 in neurons accelerates amyloid-beta -induced neuroinflammation and has been shown to trigger neuronal pyroptosis in murine Alzheimer's disease models. However, the pathways involved in amyloid-beta activation of inflammasomes have yet to be elucidated. In this study, a gene trap mutagenesis approach was utilised to resolve the genes functionally involved in inflammasome signalling within neurons, and the mechanism behind amyloid-beta-induced neuronal death. The results indicate that amyloid-beta significantly accelerated neuroinflammatory cell death in the presence of a primed inflammasome (the NLR family pyrin domain-containing 1). The mutagenesis screen discovered the atypical mitochondrial Ras homolog family member T1 as a significant contributor to amyloid-beta-induced inflammasome -mediated neuronal death. The mutagenesis screen also identified two genes involved in transforming growth factor beta signalling, namely Transforming Growth Factor Beta Receptor 1 and SNW domain containing 1. Additionally, a gene associated with cytoskeletal reorganisation, SLIT-ROBO Rho GTPase Activating Protein 3 was found to be neuroprotective. In conclusion, these genes could play important roles in inflammasome signalling in neurons, which makes them promising therapeutic targets for future drug development against neuroinflammation in Alzheimer's disease

A two-stage optimization method for Vehicle to Grid coordination considering building and Electric Vehicle user expectations

The formulation of the Vehicle to Grid (V2G) scheme should ideally consider both Electric Vehicle (EV) and building owners’ viewpoints. From the building owner’s viewpoint, the EVs should be present in the building and participate consistently to deliver the required power. From the EV owners’ viewpoint, participating in the V2G scheme should provide economic incentives while not compromising their travel needs. However, those proposed V2G algorithms up to this point in time had not considered any corrections required in response to unplanned changes in the EV travel plan. In this paper, a Two-stage optimization technique is proposed to determine the charging and discharging schedule for EVs participating in a vehicle-to-grid (V2G) programme at an office building. The EV owners’ travel convenience is focused with more attention in the proposed model by giving them two V2G options. Firstly, day-ahead optimization (DAO) is applied, based on the expected building load profile and EV behaviour, the optimal charging or discharging control of the EVs is obtained in order to save electricity bills by minimizing the maximum demand of the building. Subsequently, a real-time optimization (RTO) is performed to adjust the V2G operation based on actual vehicle behaviours which usually deviate from their estimations. Simulations are conducted and the preliminary results show that the proposed technique is able to adjust the EV charging or discharging in real-time with the aid of the day-ahead stage. The proposed model manages to capture a new ideal optimal maximum demand point and maintain the EV SOC profile as planned from the DAO stage in real-time when prediction deviation occurs. In addition, a comprehensive cost–benefit analysis in utilizing V2G in peak load reduction is also performed to gain insight into the potential savings and discharging rewards attributable to the building and EV owner respectively