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  1. Teah YF, Abduraman MA, Amanah A, Adenan MI, Sulaiman SF, Tan ML
    Food Chem Toxicol, 2017 Sep;107(Pt A):293-301.
    PMID: 28689918 DOI: 10.1016/j.fct.2017.07.011
    Elephantopus scaber Linn and its major bioactive component, deoxyelephantopin are known for their medicinal properties and are often reported to have various cytotoxic and antitumor activities. This plant is widely used as folk medicine for a plethora of indications although its safety profile remains unknown. Human ether-a-go-go-related gene (hERG) encodes the cardiac IKr current which is a determinant of the duration of ventricular action potentials and QT interval. The hERG potassium channel is an important antitarget in cardiotoxicity evaluation. This study investigated the effects of deoxyelephantopin on the current, mRNA and protein expression of hERG channel in hERG-transfected HEK293 cells. The hERG tail currents following depolarization pulses were insignificantly affected by deoxyelephantopin in the transfected cell line. Current reduction was less than 40% as compared with baseline at the highest concentration of 50 μM. The results were consistent with the molecular docking simulation and hERG surface protein expression. Interestingly, it does not affect the hERG expression at both transcriptional and translational level at most concentrations, although higher concentration at 10 μM caused protein accumulation. In conclusion, deoxyelephantopin is unlikely a clinically significant hERG channel and Ikr blocker.
    Matched MeSH terms: Myocardium/metabolism*; Potassium/metabolism*; Ether-A-Go-Go Potassium Channels/metabolism; Delayed Rectifier Potassium Channels/metabolism
  2. Baba WN, Mudgil P, Kamal H, Kilari BP, Gan CY, Maqsood S
    J Dairy Sci, 2021 Feb;104(2):1364-1377.
    PMID: 33309363 DOI: 10.3168/jds.2020-19271
    This study explores the inhibitory properties of camel whey protein hydrolysates (CWPH) toward α-amylase (AAM) and α-glucosidase (AG). A general full factorial design (3 × 3) was applied to study the effect of temperature (30, 37, and 45°C), time (120, 240, and 360 min), and enzyme (pepsin) concentration (E%; 0.5, 1, and 2%). The results showed that maximum degree of hydrolysis was obtained when hydrolysis was carried out at higher temperature (45°C; P < 0.05), compared with lower temperatures of 30 and 37°C. Electrophoretic pattern displays degradation of all protein bands upon hydrolysis by pepsin at various hydrolysis conditions applied. All the 27 CWPH generated showed significant AAM and AG inhibitory potential as indicated by their lower IC50 values (mg/mL) compared with intact whey proteins. In total 196 peptides were identified from selected hydrolysates and 15 potential peptides (PepSite score > 0.8; http://pepsite2.russelllab.org/) were explored via in silico approach. Novel peptides PAGNFLMNGLMHR, PAVACCLPPLPCHM, MLPLMLPFTMGY, and PAGNFLPPVAAAPVM were identified as potential inhibitors for both AAM and AG due to their high number of binding sites and highest binding probability toward the target enzymes. CCGM and MFE, as well as FCCLGPVPP were identified as AG and AAM inhibitory peptides, respectively. This is the first study that reports novel AG and AAM inhibitory peptides from camel whey proteins. The future direction for this research involves synthesis of these potential AG and AAM inhibitory peptides in a pure form and investigate their antidiabetic properties in the in vitro, as well as in vivo models. Thus, CWPH can be considered for potential applications in glycaemic regulation.
    Matched MeSH terms: alpha-Glucosidases/metabolism; Pepsin A/metabolism; Peptides/metabolism; Glycoside Hydrolase Inhibitors/metabolism
  3. Kosaisavee V, Suwanarusk R, Chua ACY, Kyle DE, Malleret B, Zhang R, et al.
    Blood, 2017 09 14;130(11):1357-1363.
    PMID: 28698207 DOI: 10.1182/blood-2017-02-764787
    Two malaria parasites of Southeast Asian macaques, Plasmodium knowlesi and P cynomolgi, can infect humans experimentally. In Malaysia, where both species are common, zoonotic knowlesi malaria has recently become dominant, and cases are recorded throughout the region. By contrast, to date, only a single case of naturally acquired P cynomolgi has been found in humans. In this study, we show that whereas P cynomolgi merozoites invade monkey red blood cells indiscriminately in vitro, in humans, they are restricted to reticulocytes expressing both transferrin receptor 1 (Trf1 or CD71) and the Duffy antigen/chemokine receptor (DARC or CD234). This likely contributes to the paucity of detectable zoonotic cynomolgi malaria. We further describe postinvasion morphologic and rheologic alterations in P cynomolgi-infected human reticulocytes that are strikingly similar to those observed for P vivax These observations stress the value of P cynomolgi as a model in the development of blood stage vaccines against vivax malaria.
    Matched MeSH terms: Duffy Blood-Group System/metabolism*; Receptors, Cell Surface/metabolism*; Receptors, Transferrin/metabolism*; Antigens, CD/metabolism*
  4. Ismail NA, Dom NC, Ismail R, Ahmad AH, Zaki A, Camalxaman SN
    J Am Mosq Control Assoc, 2015 Dec;31(4):305-12.
    PMID: 26675451 DOI: 10.2987/moco-31-04-305-312.1
    A study was conducted to establish polymorphic variation of the mitochondrial DNA encoding the cytochrome oxidase subunit 1 (CO1) gene in Aedes albopictus isolated from 2 hot spot dengue-infested areas in the Subang Jaya District, Malaysia. A phylogenetic analysis was performed with the use of sequences obtained from USJ6 and Taman Subang Mas (TSM). Comparison of the local CO1 sequences with a laboratory strain (USM), alongside reference strains derived from the GenBank database revealed low genetic variation in terms of nucleotide differences and haplotype diversity. Four methods were used to construct a phylogenetic tree and illustrate the genetic relationship of the 37 Ae. albopictus populations based on the CO1 sequences, namely neighbor-joining (NJ), maximum parsimony (MP), maximum likelihood (ML), and Bayesian method, which revealed a distinct relationship between isolates from USJ6 and TSM. Our findings provide new information regarding the genetic diversity among morphologically similar Ae. albopictus, which has not been reported to date.
    Matched MeSH terms: Electron Transport Complex IV/metabolism; Insect Vectors/metabolism; Insect Proteins/metabolism; Mitochondrial Proteins/metabolism
  5. Taha H, Arya A, Paydar M, Looi CY, Wong WF, Vasudeva Murthy CR, et al.
    Food Chem Toxicol, 2014 Apr;66:295-306.
    PMID: 24518542 DOI: 10.1016/j.fct.2014.01.054
    The current study aimed to ascertain the antidiabetic potential of Pseuduvaria monticola bark methanolic extract (PMm) using in vitro mechanistic study models. In particular, the study determined the effect of PMm on cellular viability, 2-NBDG glucose uptake, insulin secretion, and NF-κB translocation in mouse pancreatic insulinoma cells (NIT-1). Furthermore, in vivo acute toxicity and antidiabetic studies were performed using streptozotocin (STZ)-induced type 1 and STZ-nicotinamide-induced type 2 diabetic rat models to evaluate various biochemical parameters and markers of oxidative stress and pro-inflammatory cytokines. Five isoquinoline alkaloids and three phenolic compounds were tentatively identified in the PMm by LC/MS Triple TOF. The study results showed that PMm is non-toxic to NIT-1 cells and significantly increased the glucose uptake and insulin secretion without affecting the translocation of NF-κB. Moreover, the non-toxic effects of PMm were confirmed through an in vivo acute toxicity study, which revealed that the serum insulin and C-peptide levels were significantly upregulated in type 2 diabetic rats and that no significant changes were observed in type 1 diabetic rats. Similarly, PMm was found to downregulate the levels of oxidative stress and pro-inflammatory cytokines in type 2 diabetic rats by alleviating hyperglycemia. Therefore, we conclude that PMm may be developed as an antidiabetic agent for the treatment of type 2 diabetes-associated conditions.
    Matched MeSH terms: Diabetes Mellitus, Type 2/metabolism*; Insulin/metabolism*; Cytokines/metabolism*; Inflammation Mediators/metabolism
  6. Tan HT, Chek MF, Lakshmanan M, Foong CP, Hakoshima T, Sudesh K
    Int J Biol Macromol, 2020 Sep 15;159:250-257.
    PMID: 32417540 DOI: 10.1016/j.ijbiomac.2020.05.064
    Among the various types of polyhydroxyalkanoate (PHA), poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] [P(3HB-co-3HHx)] has a high potential to serve as commercial bioplastic due to its striking resemblance to petroleum-based plastics. In this study, five different genotypes of Cupriavidusnecator transformants harbouring the phaCBP-M-CPF4 gene (including PHB¯4/pBBR1-CBP-M-CPF4) were developed to evaluate the efficiency of 3HHx monomer incorporation. The fraction of 3-hydroxyhexanoate (3HHx) monomer that was incorporated into the PHA synthesized by these C. necator transformants using palm oil as the sole carbon source, was examined. Overall, co-expression of enoyl-CoA hydratase gene (phaJ1) from Pseudomonas aeruginosa, along with PHA synthase (PhaC), increased the 3HHx composition in the PHA copolymer. The differences in the enzyme activities of β-ketothiolase (PhaACn) and NADPH-dependent acetoacetyl-CoA reductase (PhaBCn) of the C. necator mutant hosts used in this study, were observed to alter the 3HHx composition and molecular weight of the PHA copolymer produced. The 3HHx fractions in the P(3HB-co-3HHx) produced by these C. necator transformants ranged between 1 and 18 mol%, while the weight-average molecular weight ranged from 0.7 × 106 to 1.8 × 106 Da. PhaCBP-M-CPF4 displayed a typical initial lag-phase and a relatively low synthase activity in the in vitro enzyme assay, which is thought to be the reason for the higher molecular weights of PHA obtained in this study.
    Matched MeSH terms: Acyltransferases/metabolism*; Plant Oils/metabolism*; Polymers/metabolism; Cupriavidus necator/metabolism*
  7. Wong CY, Chang YM, Tsai YS, Ng WV, Cheong SK, Chang TY, et al.
    BMC Genomics, 2020 Jul 07;21(1):467.
    PMID: 32635896 DOI: 10.1186/s12864-020-06868-5
    BACKGROUND: Mesangial cells play an important role in the glomerulus to provide mechanical support and maintaine efficient ultrafiltration of renal plasma. Loss of mesangial cells due to pathologic conditions may lead to impaired renal function. Mesenchymal stem cells (MSC) can differentiate into many cell types, including mesangial cells. However transcriptomic profiling during MSC differentiation into mesangial cells had not been studied yet. The aim of this study is to examine the pattern of transcriptomic changes during MSC differentiation into mesangial cells, to understand the involvement of transcription factor (TF) along the differentiation process, and finally to elucidate the relationship among TF-TF and TF-key gene or biomarkers during the differentiation of MSC into mesangial cells.

    RESULTS: Several ascending and descending monotonic key genes were identified by Monotonic Feature Selector. The identified descending monotonic key genes are related to stemness or regulation of cell cycle while ascending monotonic key genes are associated with the functions of mesangial cells. The TFs were arranged in a co-expression network in order of time by Time-Ordered Gene Co-expression Network (TO-GCN) analysis. TO-GCN analysis can classify the differentiation process into three stages: differentiation preparation, differentiation initiation and maturation. Furthermore, it can also explore TF-TF-key genes regulatory relationships in the muscle contraction process.

    CONCLUSIONS: A systematic analysis for transcriptomic profiling of MSC differentiation into mesangial cells has been established. Key genes or biomarkers, TFs and pathways involved in differentiation of MSC-mesangial cells have been identified and the related biological implications have been discussed. Finally, we further elucidated for the first time the three main stages of mesangial cell differentiation, and the regulatory relationships between TF-TF-key genes involved in the muscle contraction process. Through this study, we have increased fundamental understanding of the gene transcripts during the differentiation of MSC into mesangial cells.

    Matched MeSH terms: Transcription Factors/metabolism; Biomarkers/metabolism; Mesangial Cells/metabolism*; Mesenchymal Stromal Cells/metabolism*
  8. Tan JW, Israf DA, Md Hashim NF, Cheah YK, Harith HH, Shaari K, et al.
    Biochem Pharmacol, 2017 Nov 15;144:132-148.
    PMID: 28813645 DOI: 10.1016/j.bcp.2017.08.010
    Mast cells play a central role in the pathogenesis of allergic reaction. Activation of mast cells by antigens is strictly dependent on the influx of extracellular calcium that involves a complex interaction between signalling molecules located within the cells. We have previously reported that tHGA, an active compound originally isolated from a local shrub known as Melicope ptelefolia, prevented IgE-mediated mast cell activation and passive systemic anaphylaxis by suppressing the release of interleukin-4 (IL-4) and tumour necrosis factor (TNF)-α from activated rat basophilic leukaemia (RBL)-2H3 cells. However, the mechanism of action (MOA) as well as the molecular target underlying the mast cell stabilising effect of tHGA has not been previously investigated. In this study, DNP-IgE-sensitised RBL-2H3 cells were pre-treated with tHGA before challenged with DNP-BSA. To dissect the MOA of tHGA in IgE-mediated mast cell activation, the effect of tHGA on the transcription of IL-4 and TNF-α mRNA was determined using Real Time-Polymerase Chain Reaction (qPCR) followed by Calcium Influx Assay to confirm the involvement of calcium in the activation of mast cells. The protein lysates were analysed by using Western Blot to determine the effect of tHGA on various important signalling molecules in the LAT-PLCγ-MAPK and PI3K-NFκB pathways. In order to identify the molecular target of tHGA in IgE-mediated mast cell activation, the LAT and LAT2 genes in RBL-2H3 cells were knocked-down by using RNA interference to establish a LAT/LAT2 competition model. The results showed that tHGA inhibited the transcription of IL-4 and TNF-α as a result of the suppression of calcium influx in activated RBL-2H3 cells. The results from Western Blot revealed that tHGA primarily inhibited the LAT-PLCγ-MAPK pathway with partial inhibition on the PI3K-p65 pathway without affecting Syk. The results from RNAi further demonstrated that tHGA failed to inhibit the release of mediators associated with mast cell degranulation under the LAT/LAT2 competition model in the absence of LAT. Collectively, this study concluded that the molecular target of tHGA could be LAT and may provide a basis for the development of a mast cell stabiliser which targets LAT.
    Matched MeSH terms: Mast Cells/metabolism*; Membrane Proteins/metabolism*; Phosphoproteins/metabolism*; Adaptor Proteins, Signal Transducing/metabolism*
  9. Konuri A, Bhat KMR, Rai KS, Gourishetti K, Phaneendra M YS
    Anat Sci Int, 2021 Mar;96(2):197-211.
    PMID: 32944877 DOI: 10.1007/s12565-020-00574-8
    Cognitive impairment due to natural or surgical menopause is always associated with estrogen deficiency leading to reduced brain-derived neurotrophic factor (BDNF). Reduced BDNF levels in menopause affect neuronal maturation, survival, axonal and dendritic arborization and the maintenance of dendritic spine density. Conventional long-term estrogen replacement therapy reported causing the risk of venous thromboembolism and breast cancer. To overcome these undesirable effects, phytoestrogens have been used in menopause-induced condition without the risk of side effects. Therefore, the aim of the present study was to investigate the effect of dietary supplementation of fenugreek seed extract (FG) either alone or in combination with choline-DHA on BDNF and dendritic arborization of pyramidal neurons in CA1 and CA3 regions of the hippocampus in ovariectomized rats. Female Wistar rats of 9-10 months old were divided into six groups as normal control (NC); ovariectomy (OVX); OVX + FG; OVX + choline-DHA; OVX + FG + choline-DHA; and OVX + estradiol. All the groups, except NC, were ovariectomized. After 2 weeks of ovariectomy, dietary supplementation was initiated for a period of 30 days. After supplementation, behavioral studies, BDNF levels and dendritic arborization were estimated. Ovariectomized (OVX) rats showed reduced BDNF levels, dendritic branching points and dendritic intersections of pyramidal neurons in CA1 and CA3 regions of the hippocampus. OVX rats supplemented with FG with choline-DHA showed significantly improved BDNF levels, dendritic branching points and dendritic intersections. These results are demonstrating that FG with choline-DHA supplementation can be an alternative for estrogen replacement therapy to modulate menopause-induced learning and memory deficits.
    Matched MeSH terms: Hippocampus/metabolism; Memory Disorders/metabolism; Neurons/metabolism; Brain-Derived Neurotrophic Factor/metabolism*
  10. Basri RS, Rahman RNZRA, Kamarudin NHA, Ali MSM
    Int J Biol Macromol, 2020 Dec 01;164:3155-3162.
    PMID: 32841666 DOI: 10.1016/j.ijbiomac.2020.08.162
    The conversion of aldehydes to valuable alkanes via cyanobacterial aldehyde deformylating oxygenase is of great interest. The availability of fossil reserves that keep on decreasing due to human exploitation is worrying, and even more troubling is the combustion emission from the fuel, which contributes to the environmental crisis and health issues. Hence, it is crucial to use a renewable and eco-friendly alternative that yields compound with the closest features as conventional petroleum-based fuel, and that can be used in biofuels production. Cyanobacterial aldehyde deformylating oxygenase (ADO) is a metal-dependent enzyme with an α-helical structure that contains di‑iron at the active site. The substrate enters the active site of every ADO through a hydrophobic channel. This enzyme exhibits catalytic activity toward converting Cn aldehyde to Cn-1 alkane and formate as a co-product. These cyanobacterial enzymes are small and easy to manipulate. Currently, ADOs are broadly studied and engineered for improving their enzymatic activity and substrate specificity for better alkane production. This review provides a summary of recent progress in the study of the structure and function of ADO, structural-based engineering of the enzyme, and highlight its potential in producing biofuels.
    Matched MeSH terms: Bacterial Proteins/metabolism; Enzymes, Immobilized/metabolism; Mixed Function Oxygenases/metabolism*; 3,4-Dihydroxyphenylacetic Acid/metabolism
  11. Yiau SK, Lee C, Mohd Tohit ER, Chang KM, Abdullah M
    J Recept Signal Transduct Res, 2019 Jun;39(3):276-282.
    PMID: 31509041 DOI: 10.1080/10799893.2019.1660899
    Acute myeloid leukemia (AML) constitutively express growth factors and cytokines for survival. Chemotherapy alters these signals to induce cell death. However, drug resistance in AML remains a major hindrance to successful treatment and early warning is unavailable. Modulation of signaling pathways during chemotherapy may provide a window to detect response and predict treatment outcome. Blood samples collected from AML patients before and at day-3 of induction therapy were compared for changes in expression of CD117, CD34, pro-inflammatory cytokines and mediators of Akt and MAPK pathways, using multi-color flow cytometry. Nine patients were diagnosed as drug-resistant and seven sensitive to chemotherapy. Twelve were paired. Average percentages of CD34 (66.8 ± 11.7% vs. 26.2 ± 5.8%, p = 0.033) and pBAD (66.9 ± 8.2% vs. 28.9 ± 8.2%, p = 0.016) were significantly increased in chemo-resistant (N = 9) compared to chemo-sensitive (N = 5) samples. Percentages of CD34 were strongly correlated with pBAD (R = 0.785; p = 0.001; N = 14) and pFKHR (R = 0.755; p = 0.002; N = 14) at day-3 induction. Chemo-sensitive cases expressed significantly higher percentages of IL-18Rα (71.9 ± 9.6% vs. 29.8 ± 5.8%, p = 0.016). Though not significantly different in the outcome, IL-1β was strongly associated with activated Akt-S473, IL-6 with phosphorylated JNK and FKHR while TNF-α appeared to trigger Bim, in treated samples. These preliminary results suggested AML cells resistant to chemotherapy increased expression of CD34 and may signal through pBAD while cells sensitive to chemotherapy-induced IL18Rα expression. These were observed early during induction therapy. Identifying CD34 is interesting as it is a convenient marker to monitor drug-resistance in AML patients. Inhibition of CD34 and pBAD signaling may be important in treating drug-resistant AML.
    Matched MeSH terms: Leukemia, Myeloid, Acute/metabolism*; Cytokines/metabolism; Antigens, CD34/metabolism*; bcl-Associated Death Protein/metabolism*
  12. Low END, Mokhtar NM, Wong Z, Raja Ali RA
    J Crohns Colitis, 2019 May 27;13(6):755-763.
    PMID: 30954025 DOI: 10.1093/ecco-jcc/jjz002
    BACKGROUND AND AIMS: Patients with ulcerative colitis [UC] with long disease duration have a higher risk of developing colitis-associated cancer [CAC] compared with patients with short-duration UC. The aim of this study was to identify transcriptomic differences associated with the duration of UC disease.

    METHODS: We conducted transcriptome profiling on 32 colonic biopsies [11 long-duration UC, ≥20 years; and 21 short-duration UC, ≤5 years] using Affymetrix Human Transcriptome Array 2.0. Differentially expressed genes [fold change > 1.5, p < 0.05] and alternative splicing events [splicing index > 1.5, p < 0.05] were determined using the Transcriptome Analysis Console. KOBAS 3.0 and DAVID 6.8 were used for KEGG and GO analysis. Selected genes from microarray analysis were validated using qPCR.

    RESULTS: There were 640 differentially expressed genes between both groups. The top ten upregulated genes were HMGCS2, UGT2A3 isoforms, B4GALNT2, MEP1B, GUCA2B, ADH1C, OTOP2, SLC9A3, and LYPD8; the top ten downregulated genes were PI3, DUOX2, VNN1, SLC6A14, GREM1, MMP1, CXCL1, TNIP3, TFF1, and LCN2. Among the 123 altered KEGG pathways, the most significant were metabolic pathways; fatty acid degradation; valine, leucine, and isoleucine degradation; the peroxisome proliferator-activated receptor signalling pathway; and bile secretion, which were previously linked with CAC. Analysis showed that 3560 genes exhibited differential alternative splicing between long- and short-duration UC. Among them, 374 were differentially expressed, underscoring the intrinsic relationship between altered gene expression and alternative splicing.

    CONCLUSIONS: Long-duration UC patients have altered gene expressions, pathways, and alternative splicing events as compared with short-duration UC patients, and these could be further validated to improve our understanding of the pathogenesis of CAC.

    Matched MeSH terms: Cell Transformation, Neoplastic/metabolism; Colitis, Ulcerative/metabolism; Colon/metabolism; Intestinal Mucosa/metabolism
  13. Chan EWL, Yeo ETY, Wong KWL, See ML, Wong KY, Gan SY
    Curr Alzheimer Res, 2019;16(3):251-260.
    PMID: 30819080 DOI: 10.2174/1567205016666190228124630
    BACKGROUND: Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder that eventually leads to severe cognitive impairment. Although the exact etiologies of AD still remain elusive, increasing evidence suggests that neuroinflammation cascades mediated by microglial cells are associated with AD. Piper sarmentosum Roxb. (PS) is a medicinal plant reported to possess various biological properties, including anti-inflammatory, anti-psychotic and anti-oxidant activity. However, little is known about the anti-inflammatory activity of PS roots despite their traditional use to treat inflammatory- mediated ailments.

    OBJECTIVE: This study aimed to evaluate the anti-inflammatory and neuroprotective properties of extracts obtained from the roots of PS against beta-amyloid (Aβ)-induced microglial toxicity associated with the production of pro-inflammatory mediators.

    METHOD: BV2 microglial cells were treated with hexane (RHXN), dichloromethane (RDCM), ethyl acetate (REA) and methanol (RMEOH) extracts of the roots of PS prior to activation by Aβ. The production and mRNA expression of pro-inflammatory mediators were evaluated by Griess reagent, ELISA kits and RT-qPCR respectively. The phosphorylation status of p38α MAPK was determined via western blot assay. BV2 conditioned medium was used to treat SH-SY5Y neuroblastoma cells and the neuroprotective effect was assessed using MTT assay.

    RESULTS: PS root extracts, in particular RMEOH significantly attenuated the production and mRNA expression of IL-1β, IL-6 and TNF-α in Aβ-induced BV2 microglial cells. In addition, RHXN, REA and RMEOH extracts significantly reduced nitric oxide (NO) level and the inhibition of NO production was correlated with the total phenolic content of the extracts. Further mechanistic studies suggested that PS root extracts attenuated the production of cytokines by regulating the phosphorylation of p38α MAPK in microglia. Importantly, PS root extracts have protective effects against Aβ-induced indirect neurotoxicity either by inhibiting the production of NO, IL-1β, IL-6, and TNF-α in BV2 cells or by protecting SHSY5Y cells against these inflammatory mediators.

    CONCLUSIONS: These findings provided evidence that PS root extracts confer neuroprotection against Aβ- induced microglial toxicity associated with the production of pro-inflammatory mediators and may be a potential therapeutic agent for inflammation-related neurological conditions including Alzheimer's disease (AD).

    Matched MeSH terms: Inflammation/metabolism; Cytokines/metabolism*; Amyloid beta-Peptides/metabolism*; Microglia/metabolism
  14. Irvine F, Wallace AV, Sarawak SR, Houslay MD
    Biochem. J., 1993 Jul 01;293 ( Pt 1):249-53.
    PMID: 8392336
    Absence of physiological concentrations of extracellular Ca2+ in the Krebs-Henseleit incubation buffer did not affect the ability of 10 nM glucagon (< 5%) to increase hepatocyte intracellular cyclic AMP concentrations, but severely ablated (by approximately 70%) the ability of 10 nM insulin to decrease these elevated concentrations. Cyclic AMP metabolism is determined by production by adenylate cyclase and degradation by cyclic AMP phosphodiesterase (PDE). In the absence of added extracellular Ca2+ (2.5 mM), insulin's ability to activate PDE activity was selectively compromised, showing a failure of insulin to activate two of the three insulin-stimulated activities, namely the 'dense-vesicle' and peripheral plasma-membrane (PPM) PDEs. In the absence of added Ca2+, insulin's ability to inhibit adenylate cyclase activity in intact hepatocytes was decreased dramatically. Vasopressin and adrenaline (+ propranolol) failed to elicit the activation of either the 'dense-vesicle' or the PPM-PDEs. The presence of physiological concentrations of extracellular Ca2+ in the incubation medium is shown to be important for the appropriate generation of insulin's actions on cyclic AMP metabolism.
    Matched MeSH terms: Cyclic AMP/metabolism*; Adenylyl Cyclases/metabolism; Liver/metabolism*; 3',5'-Cyclic-AMP Phosphodiesterases/metabolism
  15. Liew CC, Lau YL, Fong MY, Cheong FW
    Am J Trop Med Hyg, 2020 05;102(5):1068-1071.
    PMID: 32189613 DOI: 10.4269/ajtmh.19-0836
    Invasion of human erythrocytes by merozoites of Plasmodium knowlesi involves interaction between the P. knowlesi Duffy binding protein alpha region II (PkDBPαII) and Duffy antigen receptor for chemokines (DARCs) on the erythrocytes. Information is scarce on the binding level of PkDBPαII to different Duffy antigens, Fya and Fyb. This study aims to measure the binding level of two genetically distinct PkDBPαII haplotypes to Fy(a+b-) and Fy(a+b+) human erythrocytes using erythrocyte-binding assay. The binding level of PkDBPαII of Peninsular Malaysian and Malaysian Borneon haplotypes to erythrocytes was determined by counting the number of rosettes formed in the assay. Overall, the Peninsular Malaysian haplotype displayed higher binding activity than the Malaysian Borneon haplotype. Both haplotypes exhibit the same preference to Fy(a+b+) compared with Fy(a+b-), hence justifying the vital role of Fyb in the binding to PkDBPαII. Further studies are needed to investigate the P. knowlesi susceptibility on individuals with different Duffy blood groups.
    Matched MeSH terms: Antigens, Protozoan/metabolism; Receptors, Cell Surface/metabolism; Protozoan Proteins/metabolism; Plasmodium knowlesi/metabolism*
  16. Muralitharan RR, Jama HA, Xie L, Peh A, Snelson M, Marques FZ
    Hypertension, 2020 12;76(6):1674-1687.
    PMID: 33012206 DOI: 10.1161/HYPERTENSIONAHA.120.14473
    There is increasing evidence of the influence of the gut microbiota on hypertension and its complications, such as chronic kidney disease, stroke, heart failure, and myocardial infarction. This is not surprising considering that the most common risk factors for hypertension, such as age, sex, medication, and diet, can also impact the gut microbiota. For example, sodium and fermentable fiber have been studied in relation to both hypertension and the gut microbiota. By combining second- and, now, third-generation sequencing with metabolomics approaches, metabolites, such as short-chain fatty acids and trimethylamine N-oxide, and their producers, have been identified and are now known to affect host physiology and the cardiovascular system. The receptors that bind these metabolites have also been explored with positive findings-examples include known short-chain fatty acid receptors, such as G-protein coupled receptors GPR41, GPR43, GPR109a, and OLF78 in mice. GPR41 and OLF78 have been shown to have inverse roles in blood pressure regulation, whereas GPR43 and GPR109A have to date been demonstrated to impact cardiac function. New treatment options in the form of prebiotics (eg, dietary fiber), probiotics (eg, Lactobacillus spp.), and postbiotics (eg, the short-chain fatty acids acetate, propionate, and butyrate) have all been demonstrated to be beneficial in lowering blood pressure in animal models, but the underlying mechanisms remain poorly understood and translation to hypertensive patients is still lacking. Here, we review the evidence for the role of the gut microbiota in hypertension, its risk factors, and cardiorenal complications and identify future directions for this exciting and fast-evolving field.
    Matched MeSH terms: Cardiovascular System/metabolism; Fatty Acids, Volatile/metabolism*; Hypertension/metabolism; Receptors, G-Protein-Coupled/metabolism*
  17. Wong SF, Lai LC
    Pathology, 2001 Feb;33(1):85-92.
    PMID: 11280615
    Transforming growth factor beta (TGFbeta) is secreted as a large latent precursor from both normal and transformed cells which needs to be activated for biological activity. The active TGFbeta binds either directly to TbetaR-II or indirectly by binding to beta-glycan which then presents the TGFbeta to TbetaR-II. Formation of the TGFbeta-TbetaR-II complex rapidly leads to phosphorylation of TbetaR-I. TbetaR-I, in turn, phosphorylates receptor-specific Smads and induces their translocation into the nucleus. TGFbeta is able to act as a growth stimulator or inhibitor and elicits a broad spectrum of biological effects on various cell types. However, these cells may lose their sensitivity and responsiveness to TGFbeta. Down-regulation or loss of functional receptors, aberrant signal transduction pathways due to Smad mutations, loss of the cell's ability to activate latent TGFbeta, loss of the peptide itself or functional genes that control the transcription and translation of TGFbeta may contribute to development of cancer.
    Matched MeSH terms: DNA-Binding Proteins/metabolism; Neoplasms/metabolism*; Trans-Activators/metabolism; Receptors, Transforming Growth Factor beta/metabolism
  18. Cheah PL, Looi LM
    Pathology, 1996 Aug;28(3):229-31.
    PMID: 8912350
    Eight histologically-confirmed cases of clear cell sarcoma of the kidney (CCSK) were studied for possible mutations in the p53 tumor suppressor gene by the immunohistochemical demonstration of mutant p53 proteins using a monoclonal (DO7: Dako) and a polyclonal (AB565: Chemicon) antibody to p53 protein. All cases exhibited p53 protein nuclear immunopositivity, although in varying numbers of tumor cells and with different staining intensities. p53 protein (DO7 or AB565) was expressed in < 25% of the tumor cells in four (50%) of the cases, including the one case with a known long term survival of 13 years from the time of diagnosis. The other tumors showed p53 protein immunopositivity in > 25% of the tumor cells when stained with either DO7 or AB565 or both. The intensity of staining, graded on visual impression into weak, moderate or strong, did not correlate well with the ratio of positive staining tumor cells. While this study is unable to clarify the relative prevalence and importance of p53 mutational events in the pathogenesis of this aggressive renal tumor of childhood, it is reasonably suggestive that alterations in the p53 tumor suppressor gene do occur in CCSK.
    Matched MeSH terms: Kidney Neoplasms/metabolism*; Wilms Tumor/metabolism; Tumor Suppressor Protein p53/metabolism*; Sarcoma, Clear Cell/metabolism*
  19. Abdul Mutalib NE, Mat Isa N, Alitheen NB, Song AA, Rahim RA
    Plasmid, 2014 May;73:26-33.
    PMID: 24780699 DOI: 10.1016/j.plasmid.2014.04.003
    Plasmid DNAs isolated from lactic acid bacteria (LAB) such as Lactococcus lactis (L. lactis) has been gaining more interests for its positive prospects in genetic engineering-related applications. In this study, the lactococcal plasmid, pNZ8048 was modified so as to be able to express multiple genes in the eukaryotic system. Therefore, a cassette containing an internal ribosome entry site (IRES) was cloned between VP2 gene of a very virulent infectious bursal disease (vvIBDV) UPM 04190 of Malaysian local isolates and the reporter gene, green fluorescent protein (GFP) into pNZ:CA, a newly constructed derivative of pNZ8048 harboring the cytomegalovirus promoter (Pcmv) and polyadenylation signal. The new bicistronic vector, denoted as pNZ:vig was subjected to in vitro transcription/translation system followed by SDS-PAGE and Western blot analysis to rapidly verify its functionality. Immunoblotting profiles showed the presence of 49 and 29kDa bands that corresponds to the sizes of the VP2 and GFP proteins respectively. This preliminary result shows that the newly constructed lactococcal bicistronic vector can co-express multiple genes in a eukaryotic system via the IRES element thus suggesting its feasibility to be used for transfection of in vitro cell cultures and vaccine delivery.
    Matched MeSH terms: Genetic Vectors/metabolism; Ribosomes/metabolism*; Viral Structural Proteins/metabolism*; Green Fluorescent Proteins/metabolism*
  20. Anwar F, Saleem U, Ahmad B, Ashraf M, Rehman AU, Froeyen M, et al.
    Comput Biol Chem, 2020 Dec;89:107378.
    PMID: 33002716 DOI: 10.1016/j.compbiolchem.2020.107378
    Neurodegenerative diseases have complex etiology and pose a challenge to scientists to develop simple and cost-effective synthetic compounds as potential drug candidates for such diseases. Here, we report an extension of our previously published in silico screening, where we selected four new compounds as AChE inhibitors. Further, based on favorable binding possess, MD simulation and MMGBSA, two most promising compounds (3a and 3b) were selected, keeping in view the ease of synthesis and cost-effectiveness. Due to the critical role of BChE, LOX and α-glucosidase in neurodegeneration, the selected compounds were also screened against these enzymes. The IC50 values of 3a against AChE and BChE found to be 12.53 and 352.42 μM, respectively. Moderate to slight inhibitions of 45.26 % and 28.68 % were presented by 3a against LOX and α-glucosidase, respectively, at 0.5 mM. Insignificant inhibitions were observed with 3b against the four selected enzymes. Further, in vivo trial demonstrated that 3a could significantly diminish AChE levels in the mice brain as compared to the control. These findings were in agreement with the histopathological analysis of the brain tissues. The results corroborate that selected compounds could serve as a potential lead for further development and optimization as AChE inhibitors to achieve cost-effective anti-Alzheimer's drugs.
    Matched MeSH terms: Acetylcholinesterase/metabolism*; Butyrylcholinesterase/metabolism; Cholinesterase Inhibitors/metabolism; Naphthalenes/metabolism
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