Displaying publications 101 - 120 of 9224 in total

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  1. Recent advances in production of succinic acid from lignocellulosic biomass
    Akhtar J, Idris A, Abd Aziz R
    Appl Microbiol Biotechnol, 2014 Feb;98(3):987-1000.
    PMID: 24292125 DOI: 10.1007/s00253-013-5319-6
    Production of succinic acid via separate enzymatic hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) are alternatives and are environmentally friendly processes. These processes have attained considerable positions in the industry with their own share of challenges and problems. The high-value succinic acid is extensively used in chemical, food, pharmaceutical, leather and textile industries and can be efficiently produced via several methods. Previously, succinic acid production via chemical synthesis from petrochemical or refined sugar has been the focus of interest of most reviewers. However, these expensive substrates have been recently replaced by alternative sustainable raw materials such as lignocellulosic biomass, which is cheap and abundantly available. Thus, this review focuses on succinic acid production utilizing lignocellulosic material as a potential substrate for SSF and SHF. SSF is an economical single-step process which can be a substitute for SHF - a two-step process where biomass is hydrolyzed in the first step and fermented in the second step. SSF of lignocellulosic biomass under optimum temperature and pH conditions results in the controlled release of sugar and simultaneous conversion into succinic acid by specific microorganisms, reducing reaction time and costs and increasing productivity. In addition, main process parameters which influence SHF and SSF processes such as batch and fed-batch fermentation conditions using different microbial strains are discussed in detail.
    Matched MeSH terms: Lignin/metabolism*; Succinic Acid/metabolism*
  2. Distribution of Kiss2 receptor in the brain and its localization in neuroendocrine cells in the zebrafish
    Ogawa S, Sivalingam M, Anthonysamy R, Parhar IS
    Cell Tissue Res, 2020 Feb;379(2):349-372.
    PMID: 31471710 DOI: 10.1007/s00441-019-03089-5
    Kisspeptin is a hypothalamic neuropeptide, which acts directly on gonadotropin-releasing hormone (GnRH)-secreting neurons via its cognate receptor (GPR54 or Kiss-R) to stimulate GnRH secretion in mammals. In non-mammalian vertebrates, there are multiple kisspeptins (Kiss1 and Kiss2) and Kiss-R types. Recent gene knockout studies have demonstrated that fish kisspeptin systems are not essential in the regulation of reproduction. Studying the detailed distribution of kisspeptin receptor in the brain and pituitary is important for understanding the multiple action sites and potential functions of the kisspeptin system. In the present study, we generated a specific antibody against zebrafish Kiss2-R (=Kiss1Ra/GPR54-1/Kiss-R2/KissR3) and examined its distribution in the brain and pituitary. Kiss2-R-immunoreactive cell bodies are widely distributed in the brain including in the dorsal telencephalon, preoptic area, hypothalamus, optic tectum, and in the hindbrain regions. Double-labeling showed that not all but a subset of preoptic GnRH3 neurons expresses Kiss2-R, while Kiss2-R is expressed in most of the olfactory GnRH3 neurons. In the posterior preoptic region, Kiss2-R immunoreactivity was seen in vasotocin cells. In the pituitary, Kiss2-R immunoreactivity was seen in corticotropes, but not in gonadotropes. The results in this study suggest that Kiss2 and Kiss2-R signaling directly serve non-reproductive functions and indirectly subserve reproductive functions in teleosts.
    Matched MeSH terms: Brain/metabolism*; Gonadotropin-Releasing Hormone/metabolism; Neurons/metabolism; Neuropeptides/metabolism; Pituitary Gland/metabolism; Pyrrolidonecarboxylic Acid/metabolism; Zebrafish/metabolism*; Zebrafish Proteins/metabolism*; Neuroendocrine Cells/metabolism*; Kisspeptins/metabolism*; Cell Body/metabolism
  3. Protein adaptors assemble functional proteins on DNA scaffolds
    Ngo TA, Dinh H, Nguyen TM, Liew FF, Nakata E, Morii T
    Chem Commun (Camb), 2019 Oct 15;55(83):12428-12446.
    PMID: 31576822 DOI: 10.1039/c9cc04661e
    DNA is an attractive molecular building block to construct nanoscale structures for a variety of applications. In addition to their structure and function, modification the DNA nanostructures by other molecules opens almost unlimited possibilities for producing functional DNA-based architectures. Among the molecules to functionalize DNA nanostructures, proteins are one of the most attractive candidates due to their vast functional variations. DNA nanostructures loaded with various types of proteins hold promise for applications in the life and material sciences. When loading proteins of interest on DNA nanostructures, the nanostructures by themselves act as scaffolds to specifically control the location and number of protein molecules. The methods to arrange proteins of interest on DNA scaffolds at high yields while retaining their activity are still the most demanding task in constructing usable protein-modified DNA nanostructures. Here, we provide an overview of the existing methods applied for assembling proteins of interest on DNA scaffolds. The assembling methods were categorized into two main classes, noncovalent and covalent conjugation, with both showing pros and cons. The recent advance of DNA-binding adaptor mediated assembly of proteins on the DNA scaffolds is highlighted and discussed in connection with the future perspectives of protein assembled DNA nanoarchitectures.
    Matched MeSH terms: DNA/metabolism*; Proteins/metabolism*
  4. Fulltext Kisspeptin-1 regulates forebrain dopaminergic neurons in the zebrafish
    Abdul Satar NM, Ogawa S, Parhar IS
    Sci Rep, 2020 11 09;10(1):19361.
    PMID: 33168887 DOI: 10.1038/s41598-020-75777-0
    The habenula is a phylogenetically conserved epithalamic structure, which conveys negative information via inhibition of mesolimbic dopamine neurons. We have previously shown the expression of kisspeptin (Kiss1) in the habenula and its role in the modulation of fear responses in the zebrafish. In this study, to investigate whether habenular Kiss1 regulates fear responses via dopamine neurons in the zebrafish, Kiss1 peptides were intracranially administered close to the habenula, and the expression of dopamine-related genes (th1, th2 and dat) were examined in the brain using real-time PCR and dopamine levels using LC-MS/MS. th1 mRNA levels and dopamine levels were significantly increased in the telencephalon 24-h and 30-min after Kiss1 administration, respectively. In fish administered with Kiss1, expression of neural activity marker gene, npas4a and kiss1 gene were significantly decreased in the ventral habenula. Application of neural tracer into the median raphe, site of habenular Kiss1 neural terminal projections showed tracer-labelled projections in the medial forebrain bundle towards the telencephalon where dopamine neurons reside. These results suggest that Kiss1 negatively regulates its own neuronal activity in the ventral habenula via autocrine action. This, in turn affects neurons of the median raphe via interneurons, which project to the telencephalic dopaminergic neurons.
    Matched MeSH terms: Dopamine/metabolism; Interneurons/metabolism; Neurons/metabolism; Raphe Nuclei/metabolism; RNA, Messenger/metabolism; Telencephalon/metabolism; Prosencephalon/metabolism*; Habenula/metabolism*; Zebrafish Proteins/metabolism*; Dopaminergic Neurons/metabolism*; Kisspeptins/metabolism*
  5. A review on bio-electrochemical systems (BESs) for the syngas and value added biochemicals production
    Kumar G, Saratale RG, Kadier A, Sivagurunathan P, Zhen G, Kim SH, et al.
    Chemosphere, 2017 Jun;177:84-92.
    PMID: 28284119 DOI: 10.1016/j.chemosphere.2017.02.135
    Bio-electrochemical systems (BESs) are the microbial systems which are employed to produce electricity directly from organic wastes along with some valuable chemicals production such as medium chain fatty acids; acetate, butyrate and alcohols. In this review, recent updates about value-added chemicals production concomitantly with the production of gaseous fuels like hydrogen and methane which are considered as cleaner for the environment have been addressed. Additionally, the bottlenecks associated with the conversion rates, lower yields and other aspects have been mentioned. In spite of its infant stage development, this would be the future trend of energy, biochemicals and electricity production in greener and cleaner pathway with the win-win situation of organic waste remediation. Henceforth, this review intends to summarise and foster the progress made in the BESs and discusses its challenges and outlook on future research advances.
    Matched MeSH terms: Hydrogen/metabolism*; Methane/metabolism*
  6. Bio-cellulose Production by Beijerinckia fluminensis WAUPM53 and Gluconacetobacter xylinus 0416 in Sago By-product Medium
    Voon WWY, Muhialdin BJ, Yusof NL, Rukayadi Y, Meor Hussin AS
    Appl Biochem Biotechnol, 2019 Jan;187(1):211-220.
    PMID: 29915916 DOI: 10.1007/s12010-018-2807-2
    Bio-cellulose is the microbial extracellular cellulose that is produced by growing several microorganisms on agriculture by-products, and it is used in several food applications. This study aims to utilize sago by-product, coconut water, and the standard medium Hestrin-Schramm as the carbon sources in the culture medium for bio-cellulose production. The bacteria Beijerinkia fluminensis WAUPM53 and Gluconacetobacter xylinus 0416 were selected based on their bio-cellulose production activity. The structure was determined by Fourier transform infrared spectroscopy and scanning electron microscopy, while the toxicity safety was evaluated by brine shrimp lethality test. The results of Fourier transform infrared spectroscopy showed that the bio-cellulose produced by B. fluminensis cultivated in sago by-products was of high quality. The bio-cellulose production by B. fluminensis in the sago by-product medium was slightly higher than that in the coconut water medium and was comparable with the production in the Hestrin-Schramm medium. Brine shrimp lethality test confirmed that the bio-cellulose produced by B. fluminensis in the sago by-product medium has no toxicity, which is safe for applications in the food industry. This is the first study to determine the high potential of sago by-product to be used as a new carbon source for the bio-cellulose production.
    Matched MeSH terms: Gluconacetobacter xylinus/metabolism*; Beijerinckiaceae/metabolism*
  7. Fulltext Phosphate Dysregulation and Metabolic Syndrome
    Mironov N, Haque M, Atfi A, Razzaque MS
    Nutrients, 2022 Oct 25;14(21).
    PMID: 36364739 DOI: 10.3390/nu14214477
    Phosphorus is one of the most abundant minerals in the human body. It is essential for almost all biochemical activities through ATP formation, intracellular signal transduction, cell membrane formation, bone mineralization, DNA and RNA synthesis, and inflammation modulation through various inflammatory cytokines. Phosphorus levels must be optimally regulated, as any deviations may lead to substantial derangements in glucose homeostasis. Clinical studies have reported that hyperphosphatemia can increase an individual's risk of developing metabolic syndrome. High phosphate burden has been shown to impair glucose metabolism by impairing pancreatic insulin secretion and increasing the risk of cardiometabolic disorders. Phosphate toxicity deserves more attention as metabolic syndrome is being seen more frequently worldwide and should be investigated further to determine the underlying mechanism of how phosphate burden may increase the cardiometabolic risk in the general population.
    Matched MeSH terms: Insulin/metabolism; Phosphates/metabolism
  8. An evidence-based review of neuronal cholesterol role in dementia and statins as a pharmacotherapy in reducing risk of dementia
    Dutta S, Rahman S, Ahmad R, Kumar T, Dutta G, Banerjee S, et al.
    Expert Rev Neurother, 2021 12;21(12):1455-1472.
    PMID: 34756134 DOI: 10.1080/14737175.2021.2003705
    INTRODUCTION: Dementia is a progressive neurodegenerative disorder impairing memory and cognition. Alzheimer's Disease, followed by vascular dementia - the most typical form. Risk factors for vascular dementia include diabetes, cardiovascular disease, hyperlipidemia. Lipids' levels are significantly associated with vascular changes in the brain.

    AREAS COVERED: The present article reviews the cholesterol metabolism in the brain, which includes: the synthesis, transport, storage, and elimination process. Additionally, it reviews the role of cholesterol in the pathogenesis of dementia and statin as a therapeutic intervention in dementia. In addition to the above, it further reviews evidence in support of as well as against statin therapy in dementia, recent updates of statin pharmacology, and demerits of use of statin pharmacotherapy.

    EXPERT OPINION: Amyloid-β peptides and intraneuronal neurofibrillary tangles are markers of Alzheimer's disease. Evidence shows cholesterol modulates the functioning of enzymes associated with Amyloid-β peptide processing and synthesis. Lowering cholesterol using statin may help prevent or delay the progression of dementia. This paper reviews the role of statin in dementia and recommends extensive future studies, including genetic research, to obtain a precise medication approach for patients with dementia.

    Matched MeSH terms: Brain/metabolism; Amyloid beta-Peptides/metabolism
  9. Biodegradation of Mordant orange-1 using newly isolated strain Trichoderma harzianum RY44 and its metabolite appraisal
    Hadibarata T, Syafiuddin A, Al-Dhabaan FA, Elshikh MS, Rubiyatno
    Bioprocess Biosyst Eng, 2018 May;41(5):621-632.
    PMID: 29349549 DOI: 10.1007/s00449-018-1897-0
    Herein, we systematically reported the capability of T. harzianum RY44 for decolorization of Mordant orange-1. The fungi strains were isolated from the Universiti Teknologi Malaysia tropical rain forest. For initial screening, the decolorization was conducted using 50 strains of the fungi for 20 days incubation time and the best performance was selected. Then, the decolorization capability and fungal biomass were evaluated using different dye concentrations, namely, 0, 50, 75 and 100 ppm. Effects of the carbon sources (fructose, glucose, and galactose), nitrogen sources (ammonium nitrate, ammonium sulfate and yeast extract), surfactant (tween 80), aromatic compounds (benzoic acid, catechol and salicylic acid), and pH on the decolorization efficiency were examined. This study has found that the employed carbon sources, nitrogen sources, and aromatic compounds strongly enhance the decolorization efficiency. In addition, increasing the surfactant volume and pH generally decreased the decolorization efficiencies from 19.5 to 9.0% and 81.7 to 60.5%, respectively. In the mechanism philosophy, the present work has found that Mordant orange-1 were initially degraded by T. harzianum RY44 to benzoic acid and finally transformed into salicylic acid.
    Matched MeSH terms: Azo Compounds/metabolism*; Trichoderma/metabolism*
  10. Melatonin treatment delays postharvest senescence of broccoli with regulation of carotenoid metabolism
    Lou J, Wu C, Wang H, Cao S, Wei Y, Chen Y, et al.
    Food Chem, 2023 May 15;408:135185.
    PMID: 36525725 DOI: 10.1016/j.foodchem.2022.135185
    The effect of melatonin treatment on the carotenoid metabolism in broccoli florets during storage was explored. The results indicated that 100 µmol/L of melatonin maintained the sensory quality of broccoli florets, which retarded the increase of the L* value and the decrease of the H value. Melatonin treatment increased the activities of tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), serotonin N-acetyltransferase (SNAT) and N-acetylserotonin methyltransferase (ASMT), leading to the enrichment of endogenous melatonin content in broccoli florets. Meanwhile, the treatment inhibited the concentrations of β-carotene, β-cryptoxanthin, zeaxanthin and lutein, which was beneficial in delaying the yellowing of broccoli. In addition, a series of carotenoid biosynthetic genes such as BoPSY, BoPDS, BoZDS, BoLCYβ and BoZEP was also suppressed by melatonin. Further analysis revealed that the lower carotenoid content and the down-regulated BoNCED expression in treated broccoli resulted in less accumulation of abscisic acid precursors, inhibiting abscisic acid production during the yellowing process.
    Matched MeSH terms: Abscisic Acid/metabolism; Carotenoids/metabolism
  11. Fulltext CD36-Fatty Acid-Mediated Metastasis via the Bidirectional Interactions of Cancer Cells and Macrophages
    Zaidi NE, Shazali NAH, Leow TC, Osman MA, Ibrahim K, Cheng WH, et al.
    Cells, 2022 Nov 10;11(22).
    PMID: 36428985 DOI: 10.3390/cells11223556
    Tumour heterogeneity refers to the complexity of cell subpopulations coexisting within the tumour microenvironment (TME), such as proliferating tumour cells, tumour stromal cells and infiltrating immune cells. The bidirectional interactions between cancer and the surrounding microenvironment mark the tumour survival and promotion functions, which allow the cancer cells to become invasive and initiate the metastatic cascade. Importantly, these interactions have been closely associated with metabolic reprogramming, which can modulate the differentiation and functions of immune cells and thus initiate the antitumour response. The purpose of this report is to review the CD36 receptor, a prominent cell receptor in metabolic activity specifically in fatty acid (FA) uptake, for the metabolic symbiosis of cancer-macrophage. In this review, we provide an update on metabolic communication between tumour cells and macrophages, as well as how the immunometabolism indirectly orchestrates the tumour metastasis.
    Matched MeSH terms: Macrophages/metabolism; Antigens, CD36/metabolism
  12. The significance of CD14 in clear cell renal cell carcinoma progression and survival prognosis
    Yap NY, Ong TA, Pailoor J, Gobe G, Rajandram R
    Biomarkers, 2023 Feb;28(1):24-31.
    PMID: 36315054 DOI: 10.1080/1354750X.2022.2142292
    Purpose: CD14-positive tumour and immune cells have been implicated in cancer progression. This study evaluated the prognostic significance of CD14 immunostaining in clear cell renal cell carcinoma (ccRCC) compared to the adjacent non-cancer kidney, and serum soluble CD14 (sCD14) levels in patients versus controls.Methods: Immunohistochemistry was performed for CD14 on ccRCC and the corresponding adjacent non-cancer kidney tissue from 88 patients. Staining intensity was determined using Aperio ImageScope morphometry. Serum sCD14 was evaluated for 39 ccRCC patients and 38 non-cancer controls using ELISA. CD14 levels were compared with tumour characteristics and survival status.Results: CD14 overall and nuclear immunostaining was higher in ccRCC compared to the adjacent non-cancer kidney tissue. CD14 nuclear immunostaining in the adjacent non-cancer kidney was significantly associated with advanced stage and adverse RCC survival prognosis. Serum sCD14 concentration was elevated in ccRCC patients compared to non-cancer controls and was also significantly associated with tumour stage and worse survival prognosis. Higher CD14 expression, in particular CD14 positive immune cell infiltrates found in the adjacent non-RCC kidney tissue, were associated with tumour progression and poorer prognosis.Conclusion: The levels of CD14 in non-RCC adjacent kidney and serum could be potential prognostic indicators.
    Matched MeSH terms: Kidney/metabolism; Biomarkers, Tumor/metabolism
  13. Insights from insulin resistance pathways: Therapeutic approaches against Alzheimer associated diabetes mellitus
    Fauzi A, Thoe ES, Quan TY, Yin ACY
    J Diabetes Complications, 2023 Nov;37(11):108629.
    PMID: 37866274 DOI: 10.1016/j.jdiacomp.2023.108629
    Alzheimer Associated Diabetes Mellitus, commonly known as Type 3 Diabetes Mellitus (T3DM) is a distinct subtype of diabetes with a pronounced association with Alzheimer's disease (AD). Insulin resistance serves as a pivotal link between these two conditions, leading to diminished insulin sensitivity, hyperglycemia, and impaired glucose uptake. The brain, a vital organ in AD context, is also significantly impacted by insulin resistance, resulting in energy deficits and neuronal damage, which are hallmark features of the neurodegenerative disorder. To pave the way for potential therapeutic interventions targeting the insulin resistance pathway, it is crucial to comprehend the intricate pathophysiology of T3DM and identify the overlapped features between diabetes and AD. This comprehensive review article aims to explore various pathway such as AMPK, PPARγ, cAMP and P13K/Akt pathway as potential target for management of T3DM. Through the analysis of these complex mechanisms, our goal is to reveal their interdependencies and support the discovery of innovative therapeutic strategies. The review extensively discusses several promising pharmaceutical candidates that have demonstrated dual drug action mechanisms, addressing both peripheral and cerebral insulin resistance observed in T3DM. These candidates hold significant promise for restoring insulin function and mitigating the detrimental effects of insulin resistance on the brain. The exploration of these therapeutic options contributes to the development of innovative interventions that alleviate the burden of T3DM and enhance patient care.
    Matched MeSH terms: Brain/metabolism; Insulin/metabolism
  14. REST in the Road Map of Brain Development
    Lam XJ, Maniam S, Cheah PS, Ling KH
    Cell Mol Neurobiol, 2023 Oct;43(7):3417-3433.
    PMID: 37517069 DOI: 10.1007/s10571-023-01394-w
    Repressor element-1 silencing transcription factor (REST) or also known as neuron-restrictive silencing factor (NRSF), is the key initiator of epigenetic neuronal gene-expression modification. Identification of a massive number of REST-targeted genes in the brain signifies its broad involvement in maintaining the functionality of the nervous system. Additionally, REST plays a crucial role in conferring neuroprotection to the neurons against various stressors or insults during injuries. At the cellular level, nuclear localisation of REST is a key determinant for the functional transcriptional regulation of REST towards its target genes. Emerging studies reveal the implication of REST nuclear mislocalisation or dysregulation in several neurological diseases. The expression of REST varies depending on different types of neurological disorders, which has created challenges in the discovery of REST-targeted interventions. Hence, this review presents a comprehensive summary on the physiological roles of REST throughout brain development and its implications in neurodegenerative and neurodevelopmental disorders, brain tumours and cerebrovascular diseases. This review offers valuable insights to the development of potential therapeutic approaches targeting REST to improve pathologies in the brain. The important roles of REST as a key player in the nervous system development, and its implications in several neurological diseases.
    Matched MeSH terms: Brain/metabolism; Repressor Proteins/metabolism
  15. Fulltext Depolymerisation of the Klebsiella pneumoniae Capsular Polysaccharide K21 by Klebsiella Phage K5
    Lukianova AA, Shneider MM, Evseev PV, Egorov MV, Kasimova AA, Shpirt AM, et al.
    Int J Mol Sci, 2023 Dec 09;24(24).
    PMID: 38139119 DOI: 10.3390/ijms242417288
    Klebsiella pneumoniae is a pathogen associated with various infection types, which often exhibits multiple antibiotic resistance. Phages, or bacterial viruses, have an ability to specifically target and destroy K. pneumoniae, offering a potential means of combatting multidrug-resistant infections. Phage enzymes are another promising therapeutic agent that can break down bacterial capsular polysaccharide, which shields K. pneumoniae from the immune response and external factors. In this study, Klebsiella phage K5 was isolated; this phage is active against Klebsiella pneumoniae with the capsular type K21. It was demonstrated that the phage can effectively lyse the host culture. The adsorption apparatus of the phage has revealed two receptor-binding proteins (RBPs) with predicted polysaccharide depolymerising activity. A recombinant form of both RBPs was obtained and experiments showed that one of them depolymerised the capsular polysaccharide K21. The structure of this polysaccharide and its degradation fragments were analysed. The second receptor-binding protein showed no activity on capsular polysaccharide of any of the 31 capsule types tested, so the substrate for this enzyme remains to be determined in the future. Klebsiella phage K5 may be considered a useful agent against Klebsiella infections.
    Matched MeSH terms: Klebsiella pneumoniae/metabolism; Polysaccharides, Bacterial/metabolism
  16. Mitochondria and diabetes: insights and potential therapies
    Moorthy R, Bhattamisra SK, Pandey M, Mayuren J, Kow CS, Candasamy M
    Expert Rev Endocrinol Metab, 2024 Mar;19(2):141-154.
    PMID: 38347803 DOI: 10.1080/17446651.2024.2307526
    INTRODUCTION: Type 2 diabetes (T2D) presents significant global health and economic challenges, contributing to complications such as stroke, cardiovascular disease, kidney dysfunction, and cancer. The current review explores the crucial role of mitochondria, essential for fuel metabolism, in diabetes-related processes.

    AREAS COVERED: Mitochondrial deficits impact insulin-resistant skeletal muscles, adipose tissue, liver, and pancreatic β-cells, affecting glucose and lipid balance. Exercise emerges as a key factor in enhancing mitochondrial function, thereby reducing insulin resistance. Additionally, the therapeutic potential of mitochondrial uncoupling, which generates heat instead of ATP, is discussed. We explore the intricate link between mitochondrial function and diabetes, investigating genetic interventions to mitigate diabetes-related complications. We also cover the impact of insulin deficiency on mitochondrial function, the role of exercise in addressing mitochondrial defects in insulin resistance, and the potential of mitochondrial uncoupling. Furthermore, a comprehensive analysis of Mitochondrial Replacement Therapies (MRT) techniques is presented.

    EXPERT OPINION: MRTs hold promise in preventing the transmission of mitochondrial disease. However, addressing ethical, regulatory, and technical considerations is crucial. Integrating mitochondrial-based treatments requires a careful balance between innovation and safety. Ethical dimensions and regulatory aspects of MRT are examined, emphasizing collaborative efforts for the responsible advancement of human health.

    Matched MeSH terms: Glucose/metabolism; Mitochondria/metabolism
  17. Fulltext Social stress-induced serotonin dysfunction activates spexin in male Nile tilapia (Oreochromis Niloticus)
    Lim CH, Soga T, Parhar IS
    Proc Natl Acad Sci U S A, 2023 Jan 17;120(3):e2117547120.
    PMID: 36623187 DOI: 10.1073/pnas.2117547120
    Social disturbance in interpersonal relationships is the primary source of stress in humans. Spexin (SPX, SPX1a in cichlid), an evolutionarily conserved neuropeptide with diverse physiological functions, is up-regulated in the brain during chronic social defeat stress in teleost. On the other hand, repeated exposure to social stress can lead to dysregulation of the monoaminergic system and increase the vulnerability of developing depression. Since dysfunction of the serotonin (5-hydroxytryptamine, 5-HT) system is associated with social stress and the pathophysiology of depression, the present study investigated the regulatory relationship between the central 5-HT system and SPX1a in the male teleost, Nile tilapia (Oreochromis niloticus). To identify stress factors that regulate SPX1a gene expression, cortisol, dexamethasone (DEX), and 5-HT were used to treat tilapia brain primary cultures. Our study shows cortisol and DEX treatment had no effect on SPX1a gene expression, but SPX1a gene expression was down-regulated following 5-HT treatment. Anatomical localization showed a close association between 5-HT immunoreactive projections and SPX1a neurons in the semicircular torus. In addition, 5-HT receptors (5-HT2B) were expressed in SPX1a neurons. SPX1a immunoreactive neurons and SPX1a gene expression were significantly increased in socially defeated tilapia. On the other hand, citalopram (antidepressant, 5-HT antagonist) treatment to socially defeated tilapia normalized SPX1a gene expression to control levels. Taken together, the present study shows that 5-HT is an upstream regulator of SPX1a and that the inhibited 5-HT activates SPX1a during social defeat.
    Matched MeSH terms: Brain/metabolism; Hydrocortisone/metabolism
  18. Unravelling bacterial virulence factors in yeast: From identification to the elucidation of their mechanisms of action
    Wong Z, Ong EBB
    Arch Microbiol, 2024 Jun 15;206(7):303.
    PMID: 38878203 DOI: 10.1007/s00203-024-04023-2
    Pathogenic bacteria employ virulence factors (VF) to establish infection and cause disease in their host. Yeasts, Saccharomyces cerevisiae and Saccharomyces pombe, are useful model organisms to study the functions of bacterial VFs and their interaction with targeted cellular processes because yeast processes and organelle structures are highly conserved and similar to higher eukaryotes. In this review, we describe the principles and applications of the yeast model for the identification and functional characterisation of bacterial VFs to investigate bacterial pathogenesis. The growth inhibition phenotype caused by the heterologous expression of bacterial VFs in yeast is commonly used to identify candidate VFs. Then, subcellular localisation patterns of bacterial VFs can provide further clues about their target molecules and functions during infection. Yeast knockout and overexpression libraries are also used to investigate VF interactions with conserved eukaryotic cell structures (e.g., cytoskeleton and plasma membrane), and cellular processes (e.g., vesicle trafficking, signalling pathways, and programmed cell death). In addition, the yeast growth inhibition phenotype is also useful for screening new drug leads that target and inhibit bacterial VFs. This review provides an updated overview of new tools, principles and applications to study bacterial VFs in yeast.
    Matched MeSH terms: Bacterial Proteins/metabolism; Schizosaccharomyces/metabolism
  19. Fulltext Effects of poly(3-hydroxybutyrate) [P(3HB)] coating on the bacterial communities of artificial structures
    Chai YJ, Syauqi TA, Sudesh K, Ee TL, Ban CC, Kar Mun AC, et al.
    PLoS One, 2024;19(4):e0300929.
    PMID: 38635673 DOI: 10.1371/journal.pone.0300929
    The expanding urbanization of coastal areas has led to increased ocean sprawl, which has had both physical and chemical adverse effects on marine and coastal ecosystems. To maintain the health and functionality of these ecosystems, it is imperative to develop effective solutions. One such solution involves the use of biodegradable polymers as bioactive coatings to enhance the bioreceptivity of marine and coastal infrastructures. Our study aimed to explore two main objectives: (1) investigate PHA-degrading bacteria on polymer-coated surfaces and in surrounding seawater, and (2) comparing biofilm colonization between surfaces with and without the polymer coating. We applied poly(3-hydroxybutyrate) [P(3HB)) coatings on concrete surfaces at concentrations of 1% and 6% w/v, with varying numbers of coating cycles (1, 3, and 6). Our findings revealed that the addition of P(3HB) indeed promoted accelerated biofilm growth on the coated surfaces, resulting in an occupied area approximately 50% to 100% larger than that observed in the negative control. This indicates a remarkable enhancement, with the biofilm expanding at a rate roughly 1.5 to 2 times faster than the untreated surfaces. We observed noteworthy distinctions in biofilm growth patterns based on varying concentration and number of coating cycles. Interestingly, treatments with low concentration and high coating cycles exhibited comparable biofilm enhancements to those with high concentrations and low coating cycles. Further investigation into the bacterial communities responsible for the degradation of P(3HB) coatings identified mostly common and widespread strains but found no relation between the concentration and coating cycles. Nevertheless, this microbial degradation process was found to be highly efficient, manifesting noticeable effects within a single month. While these initial findings are promising, it's essential to conduct tests under natural conditions to validate the applicability of this approach. Nonetheless, our study represents a novel and bio-based ecological engineering strategy for enhancing the bioreceptivity of marine and coastal structures.
    Matched MeSH terms: Bacteria/metabolism; 3-Hydroxybutyric Acid/metabolism
  20. Fulltext Unearthing the role of septins in viral infections
    Khairat JE, Hatta MNA, Abdullah N, Azman AS, Calvin SYM, Syed Hassan S
    Biosci Rep, 2024 Mar 29;44(3).
    PMID: 38372298 DOI: 10.1042/BSR20231827
    Septin proteins are a subfamily of closely related GTP-binding proteins conserved in all species except for higher plants and perform essential biological processes. Septins self-assemble into heptameric or octameric complexes and form higher-order structures such as filaments, rings, or gauzes by end-to-end binding. Their close association with cell membrane components makes them central in regulating critical cellular processes. Due to their organisation and properties, septins function as diffusion barriers and are integral in providing scaffolding to support the membrane's curvature and stability of its components. Septins are also involved in vesicle transport and exocytosis through the plasma membrane by co-localising with exocyst protein complexes. Recently, there have been emerging reports of several human and animal diseases linked to septins and abnormalities in their functions. Most of our understanding of the significance of septins during microbial diseases mainly pertains to their roles in bacterial infections but not viruses. This present review focuses on the known roles of septins in host-viral interactions as detailed by various studies.
    Matched MeSH terms: Cytoplasm/metabolism; Cytoskeleton/metabolism
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