Displaying publications 41 - 60 of 9014 in total

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  1. Kinetic modeling of hydrogen production rate by photoautotrophic cyanobacterium A. variabilis ATCC 29413 as a function of both CO2 concentration and oxygen production rate
    Salleh SF, Kamaruddin A, Uzir MH, Mohamed AR, Shamsuddin AH
    Prep Biochem Biotechnol, 2017 Feb 07;47(2):111-115.
    PMID: 27143318 DOI: 10.1080/10826068.2016.1181085
    Hydrogen production by cyanobacteria could be one of the promising energy resources in the future. However, there is very limited information regarding the kinetic modeling of hydrogen production by cyanobacteria available in the literature. To provide an in-depth understanding of the biological system involved during the process, the Haldane's noncompetitive inhibition equation has been modified to determine the specific hydrogen production rate (HPR) as a function of both dissolved CO2 concentration (CTOT) and oxygen production rate (OPR). The highest HPR of 15 [Formula: see text] was found at xCO2 of 5% vol/vol and the rate consequently decreased when the CTOT and OPR were 0.015 k mol m(-3) and 0.55 mL h(-1), respectively. The model provided a fairly good estimation of the HPR with respect to the experimental data collected.
    Matched MeSH terms: Carbon Dioxide/metabolism*; Hydrogen/metabolism*; Oxygen/metabolism*; Anabaena/metabolism*
  2. A case of renal tubular rickets with absorption defect of glucose and phosphorus
    Paramaesvaran N
    Med J Malaya, 1965 Mar;19(3):224-8.
    PMID: 4220475
    Matched MeSH terms: Glucose/metabolism*; Phosphorus Metabolism Disorders*; Renal Osteodystrophy/metabolism*
  3. Fulltext Understanding the Role of ztor in Aging-related Diseases Using the Zebrafish Model
    Khor ES, Noor SM, Wong PF
    In Vivo, 2019 10 31;33(6):1713-1720.
    PMID: 31662495 DOI: 10.21873/invivo.11661
    The mammalian target of rapamycin (mTOR), a 289 kDa serine/threonine protein kinase of the phosphoinositide 3-kinase (PI3K)-related family is known for its role in regulating lifespan and the aging process in humans and rodents. Aging in zebrafish very much resembles aging in humans. Aged zebrafish often manifest with spinal curvature, cataracts and cognitive frailty, akin to human age-related phenotypical effects such as osteoarthritis, dwindling vision and cognitive dysfunction. However, the role of the zebrafish orthologue of mTOR, ztor, is less defined in these areas. This review paper discusses the tale of growing old in the zebrafish, the physiological roles of ztor in normal developmental processes and its involvement in the pathogenesis of aging-related diseases such as metabolic disorders and cancers.
    Matched MeSH terms: Aging/metabolism*; Neoplasms/metabolism; Zebrafish/metabolism*; TOR Serine-Threonine Kinases/metabolism*
  4. Bacteria consortia enhanced hydrocarbon degradation of waxy crude oil
    Rahman RNZRA, Latip W, Adlan NA, Sabri S, Ali MSM
    Arch Microbiol, 2022 Nov 12;204(12):701.
    PMID: 36370212 DOI: 10.1007/s00203-022-03316-8
    Waxy crude oil is a problem to the oil and gas industry because wax deposition in pipelines reduces the quality of the crude oil. Currently, the industry uses chemicals to solve the problem but it is not environmentally friendly. As an alternative, the biodegradation approach is one of the options. Previously eleven thermophilic bacteria were isolated and exhibited high ability to degrade hydrocarbon up to 70% of waxy crude oil. However, despite the successful study on these single bacteria strains, it is believed that biodegradation of paraffin wax requires more than a single species. Five consortia were developed based on the biodegradation efficiency of 11 bacterial strains. Consortium 3 showed the highest biodegradation (77.77%) with more long-chain alkane degraded throughout the incubation compared to other consortia. Enhancement of hydrocarbon degradation was observed for all consortia especially in long chain alkane (C18-C40). Consortium 3 exhibited higher alkane monooxygenase, alcohol dehydrogenase, lipase, and esterase activities. Moreover, the dominant bacteria in the consortia were determined by denaturing gradient gel electrophoresis (DGGE), which showed the domination of genera Geobacillus, Parageobacillus, and Anoxybacillus. It can be concluded that the bacterial consortia showed higher biodegradation and improved degrading more long-chain hydrocarbon compared to a single isolate.
    Matched MeSH terms: Alkanes/metabolism; Bacteria/metabolism; Hydrocarbons/metabolism; Waxes/metabolism
  5. Fulltext Zonula occludens-1 expression is reduced in nasal epithelial cells of allergic rhinitis patients
    Siti Sarah CO, Nur Husna SM, Md Shukri N, Wong KK, Mohd Ashari NS
    PeerJ, 2022;10:e13314.
    PMID: 35480562 DOI: 10.7717/peerj.13314
    Allergic rhinitis (AR) is a common allergic disease characterized by disruption of nasal epithelial barrier. In this study, we investigated the mRNA expression of zonula occludens-1 (ZO-1), ZO-2 and ZO-3 and histone deacetylase 1 (HDAC1) and HDAC2 in AR patients compared to healthy controls. RNA samples were extracted from nasal epithelial cells of house dust mites (HDMs)-sensitized AR patients and healthy controls (n = 28 in each group). The RNAs were reverse transcribed into cDNAs for measurement of ZO-1, ZO-2, ZO-3, HDAC1 and HDAC2 expression levels by quantitative PCR. The mRNA expression of ZO-1 was significantly decreased in AR patients compared to healthy controls (p = 0.010). No significant difference was observed in the expression levels of ZO-2, ZO-3, HDAC1 and HDAC2 in AR patients compared to healthy controls. We found significant associations of higher HDAC2 levels in AR patients with lower frequency of changing bedsheet (p = 0.043) and with AR patients sensitized to Dermatophagoides farinae (p = 0.041). Higher expression of ZO-2 was observed in AR patients who had pets (p = 0.007). In conclusion, our data indicated that ZO-1 expression was lower in AR patients contributing to decreased integrity of nasal epithelial barrier integrity, and HDAC2 may be involved in the pathogenesis of the disease.
    Matched MeSH terms: Epithelial Cells/metabolism; Nasal Mucosa/metabolism; RNA, Messenger/metabolism; Tight Junctions/metabolism
  6. Fulltext Lysosomal dysfunction induced cytosolic vacuolation and increased intracellular amyloid-beta 42 (Aβ42) in human brain endothelial cells (HBEC-5i)
    Laili IN, Nasir MHM, Jufri NF, Ibrahim FW, Hamid A
    Biomed Pharmacother, 2023 May;161:114501.
    PMID: 36931027 DOI: 10.1016/j.biopha.2023.114501
    Lysosome is a primary degradative organelle and is crucial in cellular homeostasis. A reduction in its function due to ageing has been associated with the development of Alzheimer's disease (AD), a common neurodegenerative disorder characterised by the deposition of neurotoxic amyloid plaque in the brain and cerebral vessel walls. The breakdown of the blood-brain barrier (BBB) plays a vital role in the pathogenesis of AD. However, the impact of lysosomal dysfunction on brain endothelial cells, the key component of the BBB, in the disease progression is yet to be fully understood. In this study, human brain endothelial cells (HBEC-5i) were exposed to a lysosomotropic compound, chloroquine (CQ) for 24 h. Cell viability was assessed with the 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay to determine the inhibitory concentration (IC) at IC10 (17.5 µM), IC25 (70.5 µM), and IC50 (125 µM). The morphological changes observed include vacuoles arrested in the cytosols and cell shrinkage that were more prominent at IC25 and IC50. Lysosomal dysfunction was evaluated by measuring the lysosomal-associated membrane protein-1 (LAMP-1) and microtubule-associated protein light chain 3-II (LC3-II) using the capillary-based immunoassay. LC3-II was significantly increased at IC25 and IC50 (p 
    Matched MeSH terms: Brain/metabolism; Cytosol/metabolism; Lysosomes/metabolism; Amyloid beta-Peptides/metabolism
  7. Magnesium oxide nanoparticles improved vegetative growth and enhanced productivity, biochemical potency and storage stability of harvested mustard seeds
    Gautam A, Sharma P, Ashokhan S, Yaacob JS, Kumar V, Guleria P
    Environ Res, 2023 Jul 15;229:116023.
    PMID: 37121351 DOI: 10.1016/j.envres.2023.116023
    A field study was conducted to investigate the influence of MgO-NPs priming on growth and development of mustard. Priming of mustard seeds before sowing with MgO-NPs at concentration 10, 50, 100, and 150 μg/ml enhanced the vegetative parameters of plants, with considerable increase in leaf area. MgO-NPs exposure increased the photosynthetic pigment accumulation in mustard that led to increase in biomass, carbohydrate content, and the yield in terms of total grain yield. Increased chlorophyll has simultaneously increased the oxidative stress in plants, and hence stimulated their antioxidant potential. A consistent increase was observed in the content of mustard polyphenols and activity of SOD, CAT, and APX on MgO-NPs exposure. MgO-NPs induced oxidative stress further reduced the protein content and bioavailability in mustard. We further, evaluated the influence of MgO-NPs on the quality of mustard harvested seeds. The seeds harvested from nanoprimed mustard possessed increased antioxidant potential and reduced oxidative stress. The carbohydrate and protein accumulation was significantly enhanced in response to nanopriming. Reduced chlorophyll content in seeds obtained from nanoprimed mustard indicated their potential for disease resistance and stability on long term storage. Therefore, the seeds harvested from MgO-NPs primed mustard were biochemically rich and more stable. Therefore, MgO-NPs priming can be potentially used as a novel strategy for growth promotion in plants where leaves are economically important and a strategy to enhance the seed quality under long term storage conditions.
    Matched MeSH terms: Antioxidants/metabolism; Chlorophyll/metabolism; Mustard Plant/metabolism; Seeds/metabolism
  8. Expression of His-tagged NADPH-dependent acetoacetyl-CoA reductase in recombinant Escherichia coli BL-21(DE3)
    Kee PE, Chiang YC, Ng HS, Lan JC
    J Biosci Bioeng, 2023 Oct;136(4):312-319.
    PMID: 37500302 DOI: 10.1016/j.jbiosc.2023.07.001
    Poly-3-hydroxybutyrate (P(3HB)), a member of the polyhydroxyalkanoate (PHA) family, is a biodegradable polyester with diverse industrial applications. NADPH-dependent acetoacetyl-CoA reductase (phaB) is the enzyme which plays an essential role in P(3HB) synthesis by catalyzing the conversion of the intermediates. The expression of phaB enzyme using the recombinant Escherichia coli BL-21(DE3) and the purification of the synthesized enzyme were studied. The pET-B3 plasmid harbouring the phaB gene derived from Ralstonia eutropha H16, was driven by the lac promoter in E. coli BL-21(DE3). The enzyme was expressed with different induction time, temperatures and cell age. Results showed that the cell age of 4 h, induction time of 12 h at 37°C were identified as the optimal conditions for the enzyme reductase expression. A specific activity of 0.151 U mg-1 protein and total protein concentration of 0.518 mg mg-1 of dry cell weight (DCW) were attained. Affinity chromatography was performed to purify the His-tagged phaB enzyme, in which enhanced the specific activity (14.44 U mg-1) and purification fold (38-fold), despite relative low yield (44.6%) of the enzyme was obtained. The purified phaB showed an optimal enzyme activity at 30°C and pH 8.0. The findings provide an alternative for the synthesis of the reductase enzyme which can be used in the industrial-scale production of the biodegradable polymers.
    Matched MeSH terms: Alcohol Oxidoreductases/metabolism; Hydroxybutyrates/metabolism; NADP/metabolism; Polyesters/metabolism
  9. Fulltext TRPM4 blocking antibody reduces neuronal excitotoxicity by specifically inhibiting glutamate-induced calcium influx under chronic hypoxia
    Poore CP, Hazalin NAMN, Wei S, Low SW, Chen B, Nilius B, et al.
    Neurobiol Dis, 2024 Feb;191:106408.
    PMID: 38199274 DOI: 10.1016/j.nbd.2024.106408
    Excitotoxicity arises from unusually excessive activation of excitatory amino acid receptors such as glutamate receptors. Following an energy crisis, excitotoxicity is a major cause for neuronal death in neurological disorders. Many glutamate antagonists have been examined for their efficacy in mitigating excitotoxicity, but failed to generate beneficial outcome due to their side effects on healthy neurons where glutamate receptors are also blocked. In this study, we found that during chronic hypoxia there is upregulation and activation of a nonselective cation channel TRPM4 that contributes to the depolarized neuronal membrane potential and enhanced glutamate-induced calcium entry. TRPM4 is involved in modulating neuronal membrane excitability and calcium signaling, with a complex and multifaceted role in the brain. Here, we inhibited TRPM4 using a newly developed blocking antibody M4P, which could repolarize the resting membrane potential and ameliorate calcium influx upon glutamate stimulation. Importantly, M4P did not affect the functions of healthy neurons as the activity of TRPM4 channel is not upregulated under normoxia. Using a rat model of chronic hypoxia with both common carotid arteries occluded, we found that M4P treatment could reduce apoptosis in the neurons within the hippocampus, attenuate long-term potentiation impairment and improve the functions of learning and memory in this rat model. With specificity to hypoxic neurons, TRPM4 blocking antibody can be a novel way of controlling excitotoxicity with minimal side effects that are common among direct blockers of glutamate receptors.
    Matched MeSH terms: Anoxia/metabolism; Calcium/metabolism; Neurons/metabolism; Receptors, Glutamate/metabolism
  10. Fulltext Enzyme-Assisted Discovery of Antioxidant Peptides from Edible Marine Invertebrates: A Review
    Chai TT, Law YC, Wong FC, Kim SK
    Mar Drugs, 2017 Feb 16;15(2).
    PMID: 28212329 DOI: 10.3390/md15020042
    Marine invertebrates, such as oysters, mussels, clams, scallop, jellyfishes, squids, prawns, sea cucumbers and sea squirts, are consumed as foods. These edible marine invertebrates are sources of potent bioactive peptides. The last two decades have seen a surge of interest in the discovery of antioxidant peptides from edible marine invertebrates. Enzymatic hydrolysis is an efficient strategy commonly used for releasing antioxidant peptides from food proteins. A growing number of antioxidant peptide sequences have been identified from the enzymatic hydrolysates of edible marine invertebrates. Antioxidant peptides have potential applications in food, pharmaceuticals and cosmetics. In this review, we first give a brief overview of the current state of progress of antioxidant peptide research, with special attention to marine antioxidant peptides. We then focus on 22 investigations which identified 32 antioxidant peptides from enzymatic hydrolysates of edible marine invertebrates. Strategies adopted by various research groups in the purification and identification of the antioxidant peptides will be summarized. Structural characteristic of the peptide sequences in relation to their antioxidant activities will be reviewed. Potential applications of the peptide sequences and future research prospects will also be discussed.
    Matched MeSH terms: Antioxidants/metabolism*; Invertebrates/metabolism*; Peptides/metabolism*; Aquatic Organisms/metabolism*
  11. Fulltext Linking Diabetes to Alzheimer's Disease: Potential Roles of Glucose Metabolism and Alpha-Glucosidase
    Wee AS, Nhu TD, Khaw KY, Tang KS, Yeong KY
    Curr Neuropharmacol, 2023;21(10):2036-2048.
    PMID: 36372924 DOI: 10.2174/1570159X21999221111102343
    Alzheimer's disease (AD) and type 2 diabetes mellitus (DM) are more prevalent with ageing and cause a substantial global socio-economic burden. The biology of these two conditions is well elaborated, but whether AD and type 2 DM arise from coincidental roots in ageing or are linked by pathophysiological mechanisms remains unclear. Research findings involving animal models have identified mechanisms shared by both AD and type 2 DM. Deposition of β-amyloid peptides and formation of intracellular neurofibrillary tangles are pathological hallmarks of AD. Type 2 DM, on the other hand, is a metabolic disorder characterised by hyperglycaemia and insulin resistance. Several studies show that improving type 2 DM can delay or prevent the development of AD, and hence, prevention and control of type 2 DM may reduce the risk of AD later in life. Alpha-glucosidase is an enzyme that is commonly associated with hyperglycaemia in type 2 DM. However, it is uncertain if this enzyme may play a role in the progression of AD. This review explores the experimental evidence that depicts the relationship between dysregulation of glucose metabolism and AD. We also delineate the links between alpha-glucosidase and AD and the potential role of alpha-glucosidase inhibitors in treating AD.
    Matched MeSH terms: alpha-Glucosidases/metabolism; Brain/metabolism; Glucose/metabolism; Amyloid beta-Peptides/metabolism
  12. Fulltext Metabolite Profiling of the Microalgal Diatom Chaetoceros Calcitrans and Correlation with Antioxidant and Nitric Oxide Inhibitory Activities via ¹H NMR-Based Metabolomics
    Azizan A, Ahamad Bustamam MS, Maulidiani M, Shaari K, Ismail IS, Nagao N, et al.
    Mar Drugs, 2018 May 07;16(5).
    PMID: 29735927 DOI: 10.3390/md16050154
    Microalgae are promising candidate resources from marine ecology for health-improving effects. Metabolite profiling of the microalgal diatom, Chaetoceros calcitrans was conducted by using robust metabolomics tools, namely ¹H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate data analysis (MVDA). The unsupervised data analysis, using principal component analysis (PCA), resolved the five types of extracts made by solvents ranging from polar to non-polar into five different clusters. Collectively, with various extraction solvents, 11 amino acids, cholesterol, 6 fatty acids, 2 sugars, 1 osmolyte, 6 carotenoids and 2 chlorophyll pigments were identified. The fatty acids and both carotenoid pigments as well as chlorophyll, were observed in the extracts made from medium polar (acetone, chloroform) and non-polar (hexane) solvents. It is suggested that the compounds were the characteristic markers that influenced the separation between the clusters. Based on partial least square (PLS) analysis, fucoxanthin, astaxanthin, violaxanthin, zeaxanthin, canthaxanthin, and lutein displayed strong correlation to 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and nitric oxide (NO) inhibitory activity. This metabolomics study showed that solvent extractions are one of the main bottlenecks for the maximum recovery of bioactive microalgal compounds and could be a better source of natural antioxidants due to a high value of metabolites.
    Matched MeSH terms: Amino Acids/metabolism; Antioxidants/metabolism*; Carotenoids/metabolism; Chlorophyll/metabolism; Cholesterol/metabolism; Fatty Acids/metabolism; Nitric Oxide/metabolism*; Solvents/metabolism; Diatoms/metabolism*; Microalgae/metabolism*
  13. Anaerobic fermentation of gelatinized sago starch-derived sugars to acetone-1-butanol-ethanol solvent by Clostridium acetobutylicum
    Madihah MS, Ariff AB, Khalil MS, Suraini AA, Karim MI
    Folia Microbiol (Praha), 2001;46(3):197-204.
    PMID: 11702403
    A study of the kinetics and performance of solvent-yielding batch fermentation of individual sugars and their mixture derived from enzymic hydrolysis of sago starch by Clostridium acetobutylicum showed that the use of 30 g/L gelatinized sago starch as the sole carbon source produced 11.2 g/L total solvent, i.e. 1.5-2 times more than with pure maltose or glucose used as carbon sources. Enzymic pretreatment of gelatinized sago starch yielding maltose and glucose hydrolyzates prior to the fermentation did not improve solvent production as compared to direct fermentation of gelatinized sago starch. The solvent yield of direct gelatinized sago starch fermentation depended on the activity and stability of amylolytic enzymes produced during the fermentation. The pH optima for alpha-amylase and glucoamylase were found to be at 5.3 and 4.0-4.4, respectively. alpha-Amylase showed a broad pH stability profile, retaining more than 80% of its maximum activity at pH 3.0-8.0 after a 1-d incubation at 37 degrees C. Since C. acetobutylicum alpha-amylase has a high activity and stability at low pH, this strain can potentially be employed in a one-step direct solvent-yielding fermentation of sago starch. However, the C. acetobutylicum glucoamylase was only stable at pH 4-5, maintaining more than 90% of its maximum activity after a 1-d incubation at 37 degrees C.
    Matched MeSH terms: Acetone/metabolism*; Ethanol/metabolism*; Amylases/metabolism; Carbon/metabolism; Clostridium/metabolism*; Glucan 1,4-alpha-Glucosidase/metabolism; Solvents/metabolism; Starch/metabolism*; 1-Butanol/metabolism*; Carbohydrate Metabolism
  14. Soil-to-root vegetable transfer factors for (226)Ra, (232)Th, (40)K, and (88)Y in Malaysia
    Asaduzzaman Kh, Khandaker MU, Amin YM, Bradley DA, Mahat RH, Nor RM
    J Environ Radioact, 2014 Sep;135:120-7.
    PMID: 24814722 DOI: 10.1016/j.jenvrad.2014.04.009
    Soil-to-plant transfer factors (TFs) are of fundamental importance in assessing the environmental impact due to the presence of radioactivity in soil and agricultural crops. Tapioca and sweet potato, both root crops, are popular foodstuffs for a significant fraction of the Malaysian population, and result in intake of radionuclides. For the natural field conditions experienced in production of these foodstuffs, TFs and the annual effective dose were evaluated for the natural radionuclides (226)Ra, (232)Th, (40)K, and for the anthropogenic radionuclide (88)Y, the latter being a component of fallout. An experimental tapioca field was developed for study of the time dependence of plant uptake. For soil samples from all study locations other than the experimental field, it has been shown that these contain the artificial radionuclide (88)Y, although the uptake of (88)Y has only been observed in the roots of the plant Manihot esculenta (from which tapioca is derived) grown in mining soil. The estimated TFs for (226)Ra and (232)Th for tapioca and sweet potato are very much higher than that reported by the IAEA. For all study areas, the annual effective dose from ingestion of tapioca and sweet potato are estimated to be lower than the world average (290 μSv y(-1)).
    Matched MeSH terms: Potassium Radioisotopes/metabolism; Radium/metabolism; Soil Pollutants, Radioactive/metabolism*; Thorium/metabolism; Vegetables/metabolism*; Plant Roots/metabolism*
  15. Fulltext The relationship between phenolics and flavonoids production with total non structural carbohydrate and photosynthetic rate in Labisia pumila Benth. under high CO2 and nitrogen fertilization
    Ibrahim MH, Jaafar HZ, Rahmat A, Rahman ZA
    Molecules, 2010 Dec 29;16(1):162-74.
    PMID: 21191319 DOI: 10.3390/molecules16010162
    A factorial split plot 4 × 3 experiment was designed to examine and characterize the relationship among production of secondary metabolites (total phenolics, TP; total flavonoids, TF), carbohydrate content and photosynthesis of three varieties of the Malaysian medicinal herb Labisia pumila Benth. namely the varieties alata, pumila and lanceolata under CO(2) enrichment (1,200 µmol mol(-1)) combined with four levels of nitrogen fertilization (0, 90, 180 and 270 kg N ha(-1)). No varietal differences were observed, however, as the levels of nitrogen increased from 0 to 270 kg N ha(-1), the production of TP and TF decreased in the order leaves>roots>stems. The production of TP and TF was related to increased total non structural carbohydrate (TNC), where the increase in starch content was larger than that in sugar concentration. Nevertheless, the regression analysis exhibited a higher influence of soluble sugar concentration (r(2) = 0.88) than starch on TP and TF biosynthesis. Photosynthesis, on the other hand, displayed a significant negative relationship with TP and TF production (r(2) = -0.87). A decrease in photosynthetic rate with increasing secondary metabolites might be due to an increase in the shikimic acid pathway that results in enhanced production of TP and TF. Chlorophyll content exhibited very significant negative relationships with total soluble sugar, starch and total non structural carbohydrate.
    Matched MeSH terms: Carbon Dioxide/metabolism*; Nitrogen/metabolism*; Phenols/metabolism*; Primulaceae/metabolism*; Carbohydrate Metabolism*
  16. Pathogenic responses of bradykinin system in chronic inflammatory rheumatoid disease
    Sharma JN, Buchanan WW
    Exp. Toxicol. Pathol., 1994 Dec;46(6):421-33.
    PMID: 7703672 DOI: 10.1016/S0940-2993(11)80053-9
    Excessive release of kinin (BK) in the synovial fluid can produce oedema, pain and loss of functions due to activation of B1 and B2 kinin receptors. Activation of the kinin forming system could be mediated via injury, trauma, coagulation pathways (Hageman factor and thrombin) and immune complexes. The activated B1 and B2 receptors might cause release of other powerful non-cytokine and cytokine mediators of inflammation, e.g., PGE2, PGI2, LTs, histamine, PAF, IL-1 and TNF, derived mainly from polymorphonuclear leukocytes, macrophages, endothelial cells and synovial tissue. These mediators are capable of inducing bone and cartilage damage, hypertrophic synovitis, vessel proliferation, inflammatory cell migration and, possibly, angiogenesis in pannus formation. These pathological changes, however, are not yet defined in the human model of chronic inflammation. The role of kinins and their interacting inflammatory mediators would soon start to clarify the detailed questions they revealed in clinical and experimental models of chronic inflammatory diseases. Several B1 and B2 receptor antagonists are being synthesized in an attempt to study the molecular functions of kinins in inflammatory processes, such as rheumatoid arthritis, periodontitis, inflammatory diseases of the gut and osteomyelitis. Future development of specific potent and stable B1 and B2 receptor antagonists or combined B1 and B2 antagonists with y-IFN might serve as a pharmacological basis for more effective treatment of joint inflammatory and related diseases.
    Matched MeSH terms: Arthritis, Rheumatoid/metabolism*; Bradykinin/metabolism*; Kallidin/metabolism; Kallikreins/metabolism; Kinins/metabolism*; Inflammation Mediators/metabolism
  17. Fulltext The glyoxylate cycle and alternative carbon metabolism as metabolic adaptation strategies of Candida glabrata: perspectives from Candida albicans and Saccharomyces cerevisiae
    Chew SY, Chee WJY, Than LTL
    J Biomed Sci, 2019 Jul 13;26(1):52.
    PMID: 31301737 DOI: 10.1186/s12929-019-0546-5
    BACKGROUND: Carbon utilization and metabolism are fundamental to every living organism for cellular growth. For intracellular human fungal pathogens such as Candida glabrata, an effective metabolic adaptation strategy is often required for survival and pathogenesis. As one of the host defence strategies to combat invading pathogens, phagocytes such as macrophages constantly impose restrictions on pathogens' access to their preferred carbon source, glucose. Surprisingly, it has been reported that engulfed C. glabrata are able to survive in this harsh microenvironment, further suggesting alternative carbon metabolism as a potential strategy for this opportunistic fungal pathogen to persist in the host.

    MAIN TEXT: In this review, we discuss alternative carbon metabolism as a metabolic adaptation strategy for the pathogenesis of C. glabrata. As the glyoxylate cycle is an important pathway in the utilization of alternative carbon sources, we also highlight the key metabolic enzymes in the glyoxylate cycle and its necessity for the pathogenesis of C. glabrata. Finally, we explore the transcriptional regulatory network of the glyoxylate cycle.

    CONCLUSION: Considering evidence from Candida albicans and Saccharomyces cerevisiae, this review summarizes the current knowledge of the glyoxylate cycle as an alternative carbon metabolic pathway of C. glabrata.

    Matched MeSH terms: Candida albicans/metabolism; Candidiasis/metabolism*; Carbon/metabolism*; Glyoxylates/metabolism*; Saccharomyces cerevisiae/metabolism; Candida glabrata/metabolism*
  18. Overexpression of AtWRKY50 is correlated with enhanced production of sinapic derivatives in Arabidopsis
    Hussain RMF, Kim HK, Khurshid M, Akhtar MT, Linthorst HJM
    Metabolomics, 2018 01 31;14(3):25.
    PMID: 30830336 DOI: 10.1007/s11306-018-1317-0
    INTRODUCTION: WRKY proteins belong to a plant-specific class of transcription factors. Seventy-four WKRY genes have been identified in Arabidopsis and many WRKY proteins are known to be involved in responses to stress, especially to biotic stress. They may act either as transcriptional activators or as repressors of genes that play roles in the stress response. A number of studies have proposed the connection of Arabidopsis WRKY transcription factors in induced pathogenesis-related (PR) gene expression, although no direct evidence has been presented for specific WRKY-PR promoter interactions.

    OBJECTIVE: We previously identified AtWRKY50 as a transcriptional activator of SAR gene PR1. Although PR1 accumulates to high levels in plants after attack by pathogens, its function is still elusive. Here we investigated the effects of overexpression of several WRKY proteins, including AtWRKY50, on the metabolome of Arabidopsis thaliana.

    METHODS: The influence of overexpression of WRKY proteins on the metabolites of Arabidopsis was investigated by using an NMR spectroscopy-based metabolomic approach. The 1H NMR data was analysed using the multivariate data analysis methods, such as principal component analysis, hierarchical cluster analysis and partial least square-discriminant analysis.

    RESULTS: The results showed that the metabolome of transgenic Arabidopsis seedlings overexpressing AtWRKY50 was different from wild type Arabidopsis and transgenic Arabidopsis overexpressing other WRKY genes. Amongst other metabolites, sinapic acid and 1-O-sinapoyl-β-D-glucose especially appeared to be the most prominent discriminating metabolites, accumulating to levels 2 to 3 times higher in the AtWRKY50 overexpressor lines.

    CONCLUSION: Our results indicate a possible involvement of AtWRKY50 in secondary metabolite production in Arabidopsis, in particular of hydroxycinnamates such as sinapic acid and 1-O-sinapoyl-β-D-glucose.

    Matched MeSH terms: Cinnamates/metabolism*; Coumaric Acids/metabolism*; Glucosides/metabolism*; Transcription Factors/metabolism*; Arabidopsis/metabolism*; Arabidopsis Proteins/metabolism*
  19. Fulltext Twitching motility of Stenotrophomonas maltophilia under iron limitation: In-silico, phenotypic and proteomic approaches
    V K, Neela VK
    Virulence, 2020 Dec;11(1):104-112.
    PMID: 31957553 DOI: 10.1080/21505594.2020.1713649
    This study investigates the twitching ability of 28 clinical and five environmental strains of S. maltophilia grown under iron-depleted condition through in-silico, phenotypic and proteomics approaches. Rapid Annotations using Subsystem Technology (RAST) analysis revealed the presence of 21 targets of type IV pilus shared across S. maltophilia strains K279a, R551-3, D457 and JV3. The macroscopic twitching assay showed that only clinical isolates produced a zone of twitching with a mean of 22.00 mm under normal and 25.00 mm under iron-depleted conditions. (p = 0.002). Environmental isolates did not show any significant twitching activity in both conditions tested. Isobaric Tags for Relative and Absolute Quantification (ITRAQ) analysis showed altered expression of twitching motility protein PilT (99.08-fold change), flagellar biosynthesis protein FliC (20.14-fold change), and fimbrial protein (0.70-fold change) in response to iron-depleted condition. Most of the strains that have the ability to twitch under the normal condition, exhibit enhanced twitching during iron limitation.
    Matched MeSH terms: Bacterial Proteins/metabolism; Iron/metabolism*; Fimbriae, Bacterial/metabolism; Pseudomonas aeruginosa/metabolism; Stenotrophomonas maltophilia/metabolism*; Fimbriae Proteins/metabolism
  20. Functional transcriptome reveals hepatopancreatic lipid metabolism during the molting cycle of the Chinese mitten crab Eriocheir sinensis
    Li Z, Zhang G, Pan K, Niu X, Shu-Chien AC, Chen T, et al.
    Comp Biochem Physiol A Mol Integr Physiol, 2023 Oct;284:111474.
    PMID: 37406959 DOI: 10.1016/j.cbpa.2023.111474
    Crustacean molting is highly related to energy and lipid metabolism. This study was conducted to detect the changes of total lipids (TL), triacylglyceride (TAG), phospholipid (PL) and lipid droplets in hepatopancreas, and then to investigate the gene expression patterns related to hepatopancreatic lipid metabolism during the molting cycle of Chinese mitten crab Eriocheir sinensis. Hepatopancreatic TL and TAG increased significantly from post-molt stage to pre-molt stage, then decreased significantly from pre-molt stage to ecdysis stage, which is consistent to the changes of neutral lipid-rich adipocytes in hepatopancreas. By transcriptomic analysis, 65,325 transcripts were sequenced and assembled, and 28,033 transcripts were annotated. Most genes were related to energy metabolism, and the enriched genes were involved in carbohydrate and lipid metabolism and biosynthesis, especially in de novo synthesis of fatty acids and TAG, and ketone body production. Compared to the inter-molt stages, acetyl-CoA carboxylase, fatty acid synthase and other genes related to the synthesis of fatty acids were upregulated in the pre-molt stage. TAG synthesis related genes, including Glycerol-3-phosphate acyltransferase and 1-acylglycerol-3-phosphate acyltransferases, were upregulated in the post-molt stage compared to the inter-molt stage. The expression of ketone body-related genes had no significant changes during the molting cycle. Compared to the TAG synthetic pathway, ketone body biosynthesis may contribute less/secondarily to fatty acid metabolic processes, which could be involved in the other physiological processes or metabolism. In conclusion, these results showed that TAG is the major lipid deposition during inter- and pre-molt stages, and the most genes are related to the fatty acids and TAG metabolism in the hepatopancreas during the molting cycle of E. sinensis.
    Matched MeSH terms: Fatty Acids/metabolism; Ketones/metabolism; Phosphates/metabolism; Hepatopancreas/metabolism; Lipid Metabolism/genetics
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