Displaying publications 1 - 20 of 173 in total

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  1. Tang W, Liu H, Li X, Ooi TC, Rajab NF, Cao H, et al.
    Aging (Albany NY), 2022 Nov 14;14(21):8688-8699.
    PMID: 36375474 DOI: 10.18632/aging.204380
    BACKGROUND: A complex of Zn and carnosine, called Zinc-L-carnosine (ZnC), enjoys a wide application as part of a Zn supplement therapeutic method as well as in treating peptic ulcers. However, researches fail to confirm the biological functions possessed by ZnC as well as tumor immune microenvironment in colorectal cancer (CRC).

    METHODS: Cell counting kit 8(CCK8), 5-ethynyl-2'-deoxyuridine (EdU), transwell and wound healing assays were conducted to study the influence of ZnC in the proliferating, invading and migrating processes of CRC cell lines (HCT116, LOVO) in vitro. The antitumor activity ZnC as well as its effects on tumor immune microenvironment were then assessed using CRC subcutaneous tumors in the C57BL/6 mouse model.

    RESULTS: According to CCK8, EdU, transwell and wound healing assays, ZnC inhibited CRC cell lines in terms of proliferation, invasion and migration. ZnC could inhibit miR-570 for up-regulating PD-L1 expression. In vivo experiments showed that gavage (100 mg/kg, once every day) of ZnC inhibited the tumor growth of CRC, and the combination of ZnC and anti-PD1 therapy significantly improved the efficacy exhibited by anti-PD1 in treating CRC. In addition, mass cytometry results showed that immunosuppressive cells including regulatory T cells (tregs), bone marrow-derived suppressor cells (MDSC), and M2 macrophages decreased whereas CD8+ T cells elevated after adding ZnC.

    CONCLUSIONS: The present study reveals that ZnC slows the progression of CRC by inhibiting CRC cells in terms of proliferation, invasion and migration, meanwhile up-regulating PD-L1 expression via inhibiting miR-570. The ZnC-anti-PD1 co-treatment assists in synergically increasing anti-tumor efficacy in CRC therapy.

    Matched MeSH terms: Mice, Inbred C57BL
  2. Mohamad M, Mitchell SJ, Wu LE, White MY, Cordwell SJ, Mach J, et al.
    Aging Cell, 2016 08;15(4):706-15.
    PMID: 27095270 DOI: 10.1111/acel.12481
    While age-related insulin resistance and hyperinsulinemia are usually considered to be secondary to changes in muscle, the liver also plays a key role in whole-body insulin handling and its role in age-related changes in insulin homeostasis is largely unknown. Here, we show that patent pores called 'fenestrations' are essential for insulin transfer across the liver sinusoidal endothelium and that age-related loss of fenestrations causes an impaired insulin clearance and hyperinsulinemia, induces hepatic insulin resistance, impairs hepatic insulin signaling, and deranges glucose homeostasis. To further define the role of fenestrations in hepatic insulin signaling without any of the long-term adaptive responses that occur with aging, we induced acute defenestration using poloxamer 407 (P407), and this replicated many of the age-related changes in hepatic glucose and insulin handling. Loss of fenestrations in the liver sinusoidal endothelium is a hallmark of aging that has previously been shown to cause deficits in hepatic drug and lipoprotein metabolism and now insulin. Liver defenestration thus provides a new mechanism that potentially contributes to age-related insulin resistance.
    Matched MeSH terms: Mice, Inbred C57BL
  3. Cogger VC, Mohamad M, Solon-Biet SM, Senior AM, Warren A, O'Reilly JN, et al.
    Am J Physiol Heart Circ Physiol, 2016 05 01;310(9):H1064-70.
    PMID: 26921440 DOI: 10.1152/ajpheart.00949.2015
    Fenestrations are pores within the liver sinusoidal endothelial cells (LSECs) that line the sinusoids of the highly vascularized liver. Fenestrations facilitate the transfer of substrates between blood and hepatocytes. With pseudocapillarization of the hepatic sinusoid in old age, there is a loss of fenestrations. LSECs are uniquely exposed to gut-derived dietary and microbial substrates delivered by the portal circulation to the liver. Here we studied the effect of 25 diets varying in content of macronutrients and energy on LSEC fenestrations using the Geometric Framework method in a large cohort of mice aged 15 mo. Macronutrient distribution rather than total food or energy intake was associated with changes in fenestrations. Porosity and frequency were inversely associated with dietary fat intake, while fenestration diameter was inversely associated with protein or carbohydrate intake. Fenestrations were also linked to diet-induced changes in gut microbiome, with increased fenestrations associated with higher abundance of Firmicutes and reduced abundance of Bacteroidetes Diet-induced changes in levels of several fatty acids (C16:0, C19:0, and C20:4) were also significantly inversely associated with fenestrations, suggesting a link between dietary fat and modulation of lipid rafts in the LSECs. Diet influences fenestrations and these data reflect both the key role of the LSECs in clearing gut-derived molecules from the vascular circulation and the impact these molecules have on LSEC morphology.
    Matched MeSH terms: Mice, Inbred C57BL
  4. Rajandram R, Ong TA, Razack AH, MacIver B, Zeidel M, Yu W
    Am J Physiol Renal Physiol, 2016 05 01;310(9):F885-94.
    PMID: 26911853 DOI: 10.1152/ajprenal.00483.2015
    Ketamine is a popular choice for young drug abusers. Ketamine abuse causes lower urinary tract symptoms, with the underlying pathophysiology poorly understood. Disruption of urothelial barrier function has been hypothesized to be a major mechanism for ketamine cystitis, yet the direct evidence of impaired urothelial barrier function is still lacking. To address this question, 8-wk-old female C57BL/6J mice were injected intraperitoneally with 30 mg·kg(-1)·day(-1) ketamine for 12 wk to induce ketamine cystitis. A spontaneous voiding spot assay showed that ketamine-treated mice had increased primary voiding spot numbers and smaller primary voiding spot sizes than control mice (P < 0.05), indicating a contracted bladder and bladder overactivity. Consistently, significantly increased voiding frequency was observed in ketamine-treated mice on cystometrograms. These functional experiments indicate that ketamine induces voiding dysfunction in mice. Surprisingly, urothelial permeability in ketamine-treated mice was not changed when measured using an Ussing chamber system with isotopic urea and water. Mouse urothelial structure was also not altered, and intact umbrella cell structure was observed by both transmission and scanning electron microscopy. Furthermore, immunostaining and confocal microscopy confirmed the presence of a well-defined distribution of zonula occuldens-1 in tight junctions and uroplakin in umbrella cells. In conclusion, these data indicate that ketamine injection induces voiding dysfunction in mice but does not necessarily disrupt mouse bladder barrier function. Disruption of urothelial barrier function may not be the major mechanism in ketamine cystitis.
    Matched MeSH terms: Mice, Inbred C57BL
  5. Stephenson AJ, Hunter B, Shaw PN, Kassim NSA, Trengove R, Takechi R, et al.
    Anal Bioanal Chem, 2023 Mar;415(7):1357-1369.
    PMID: 36705732 DOI: 10.1007/s00216-023-04527-8
    Despite its critical role in neurodevelopment and brain function, vitamin D (vit-D) homeostasis, metabolism, and kinetics within the central nervous system remain largely undetermined. Thus, it is of critical importance to establish an accurate, highly sensitive, and reproducible method to quantitate vit-D in brain tissue. Here, we present a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) method and for the first time, demonstrate detection of seven major vit-D metabolites in brain tissues of C57BL/6J wild-type mice, namely 1,25(OH)2D3, 3-epi-1,25(OH)2D3, 1,25(OH)2D2, 25(OH)D3, 25(OH)D2, 24,25(OH)2D3, and 24,25(OH)2D2. Chromatographic separation was achieved on a pentaflurophenyl column with 3 mM ammonium formate water/methanol [A] and 3 mM ammonium formate methanol/isopropanol [B] mobile phase components. Detection was by positive ion electrospray tandem mass spectrometry with the EVOQ elite triple quadrupole mass spectrometer with an Advance ultra-high-performance liquid chromatograph and online extraction system. Calibration standards of each metabolite prepared in brain matrices were used to validate the detection range, precision, accuracy, and recovery. Isotopically labelled analogues, 1,25(OH)2D3-d3, 25(OH)D3-c5, and 24,25(OH)2D3-d6, served as the internal standards for the closest molecular-related metabolite in all measurements. Standards between 1 fg/mL and 10 ng/mL were injected with a resulting linear range between 0.001 and 1 ng, with an LLOD and LLOQ of 1 pg/mL and 12.5 pg/mL, respectively. The intra-/inter-day precision and accuracy for measuring brain vit-D metabolites ranged between 0.12-11.53% and 0.28-9.11%, respectively. Recovery in acetonitrile ranged between 99.09 and 106.92% for all metabolites. Collectively, the sensitivity and efficiency of our method supersedes previously reported protocols used to measure vit-D and to our knowledge, the first protocol to reveal the abundance of 25(OH)D2, 1,25(OH)D2, and 24,25(OH)2D2, in brain tissue of any species. This technique may be important in supporting the future advancement of pre-clinical research into the function of vit-D in neurophysiological and neuropsychiatric disorders, and neurodegeneration.
    Matched MeSH terms: Mice, Inbred C57BL
  6. Abu Bakar MH, Azmi MN, Shariff KA, Tan JS
    Appl Biochem Biotechnol, 2019 May;188(1):241-259.
    PMID: 30417321 DOI: 10.1007/s12010-018-2920-2
    Withaferin A (WA), a bioactive constituent derived from Withania somnifera plant, has been shown to exhibit many qualifying properties in attenuating several metabolic diseases. The current investigation sought to elucidate the protective mechanisms of WA (1.25 mg/kg/day) on pre-existing obese mice mediated by high-fat diet (HFD) for 12 weeks. Following dietary administration of WA, significant metabolic improvements in hepatic insulin sensitivity, adipocytokines with enhanced glucose tolerance were observed. The hepatic oxidative functions of obese mice treated with WA were improved via augmented antioxidant enzyme activities. The levels of serum pro-inflammatory cytokines and hepatic mRNA expressions of toll-like receptor (TLR4), nuclear factor κB (NF-κB), tumor necrosis factor-α (TNF-α), chemokine (C-C motif) ligand-receptor, and cyclooxygenase 2 (COX2) in HFD-induced obese mice were reduced. Mechanistically, WA increased hepatic mRNA expression of peroxisome proliferator-activated receptors (PPARs), cluster of differentiation 36 (CD36), fatty acid synthase (FAS), carnitine palmitoyltransferase 1 (CPT1), glucokinase (GCK), phosphofructokinase (PFK), and phosphoenolpyruvate carboxykinase (PCK1) that were associated with enhanced lipid and glucose metabolism. Taken together, these results indicate that WA exhibits protective effects against HFD-induced obesity through attenuation of hepatic inflammation, oxidative stress, and insulin resistance in mice.
    Matched MeSH terms: Mice, Inbred C57BL
  7. Nallappan D, Ong KC, Palanisamy UD, Chua KH, Kuppusamy UR
    Arch Physiol Biochem, 2023 Feb;129(1):186-197.
    PMID: 32813560 DOI: 10.1080/13813455.2020.1808019
    AIM: A high-fat diet (HFD) can lead to obesity and related metabolic disorders. This study evaluated the preventive efficacy of myricetin derivative-rich fraction (MD) from Syzygium malaccense leaf extract against HFD-induced obesity, hyperglycaemia, and oxidative stress in C57BL/6J mice.

    METHODS: HFD-fed mice were administered MD (50 mg/kg, 100 mg/kg, and 150 mg/kg) or 2 mg/kg metformin (positive control) orally for 16 weeks. Normal diet and HFD-fed control groups received normal saline.

    RESULTS: MD dose of 50 mg/kg was better than 100 mg/kg and 150 mg/kg in significantly reducing weight-gain, glucose intolerance, insulin resistance, lipid accumulation in liver and kidney, and improving the serum lipid profile. Lowered protein carbonyls and lipid hydroperoxides in urine and tissue homogenates and elevated reduced glutathione, ferric reducing antioxidant power (FRAP), and Trolox equivalent antioxidant capacity (TEAC) levels in tissue homogenates indicated amelioration of oxidative stress.

    CONCLUSION: MD has therapeutic value in the prevention and management of obesity, hyperglycaemia, and oxidative stress.

    Matched MeSH terms: Mice, Inbred C57BL
  8. Yu EPK, Reinhold J, Yu H, Starks L, Uryga AK, Foote K, et al.
    Arterioscler Thromb Vasc Biol, 2017 12;37(12):2322-2332.
    PMID: 28970293 DOI: 10.1161/ATVBAHA.117.310042
    OBJECTIVE: Mitochondrial DNA (mtDNA) damage is present in murine and human atherosclerotic plaques. However, whether endogenous levels of mtDNA damage are sufficient to cause mitochondrial dysfunction and whether decreasing mtDNA damage and improving mitochondrial respiration affects plaque burden or composition are unclear. We examined mitochondrial respiration in human atherosclerotic plaques and whether augmenting mitochondrial respiration affects atherogenesis.

    APPROACH AND RESULTS: Human atherosclerotic plaques showed marked mitochondrial dysfunction, manifested as reduced mtDNA copy number and oxygen consumption rate in fibrous cap and core regions. Vascular smooth muscle cells derived from plaques showed impaired mitochondrial respiration, reduced complex I expression, and increased mitophagy, which was induced by oxidized low-density lipoprotein. Apolipoprotein E-deficient (ApoE-/-) mice showed decreased mtDNA integrity and mitochondrial respiration, associated with increased mitochondrial reactive oxygen species. To determine whether alleviating mtDNA damage and increasing mitochondrial respiration affects atherogenesis, we studied ApoE-/- mice overexpressing the mitochondrial helicase Twinkle (Tw+/ApoE-/-). Tw+/ApoE-/- mice showed increased mtDNA integrity, copy number, respiratory complex abundance, and respiration. Tw+/ApoE-/- mice had decreased necrotic core and increased fibrous cap areas, and Tw+/ApoE-/- bone marrow transplantation also reduced core areas. Twinkle increased vascular smooth muscle cell mtDNA integrity and respiration. Twinkle also promoted vascular smooth muscle cell proliferation and protected both vascular smooth muscle cells and macrophages from oxidative stress-induced apoptosis.

    CONCLUSIONS: Endogenous mtDNA damage in mouse and human atherosclerosis is associated with significantly reduced mitochondrial respiration. Reducing mtDNA damage and increasing mitochondrial respiration decrease necrotic core and increase fibrous cap areas independently of changes in reactive oxygen species and may be a promising therapeutic strategy in atherosclerosis.

    Matched MeSH terms: Mice, Inbred C57BL
  9. Sakihama H, Lee GR, Chin BY, Csizmadia E, Gallo D, Qi Y, et al.
    Arterioscler Thromb Vasc Biol, 2021 Jun;41(6):1915-1927.
    PMID: 33853347 DOI: 10.1161/ATVBAHA.120.315558
    [Figure: see text].
    Matched MeSH terms: Mice, Inbred C57BL
  10. Abdullah F, Khan Nor-Ashikin MN, Agarwal R, Kamsani YS, Abd Malek M, Bakar NS, et al.
    Asian J Androl, 2021 1 22;23(3):281-287.
    PMID: 33473013 DOI: 10.4103/aja.aja_81_20
    Diabetes mellitus (DM) is known to cause reproductive impairment. In men, it has been linked to altered sperm quality and testicular damage. Oxidative stress (OS) plays a pivotal role in the development of DM complications. Glutathione (GSH) is a part of a nonenzymatic antioxidant defense system that protects lipid, protein, and nucleic acids from oxidative damage. However, the protective effects of exogenous GSH on the male reproductive system have not been comprehensively examined. This study determined the impact of GSH supplementation in ameliorating the adverse effect of type 1 DM on sperm quality and the seminiferous tubules of diabetic C57BL/6NTac mice. GSH at the doses of 15 mg kg-1 and 30 mg kg-1 was given intraperitoneally to mice weekly for 6 consecutive weeks. The mice were then weighed, euthanized, and had their reproductive organs excised. The diabetic (D Group) showed significant impairment of sperm quality and testicular histology compared with the nondiabetic (ND Group). Diameters of the seminiferous lumen in diabetic mice treated with 15 mg kg-1 GSH (DGSH15) were decreased compared with the D Group. Sperm motility was also significantly increased in the DGSH15 Group. Improvement in testicular morphology might be an early indication of the protective roles played by the exogenous GSH in protecting sperm quality from effects of untreated type 1 DM or diabetic complications. Further investigation using different doses and different routes of GSH is necessary to confirm this suggestion.
    Matched MeSH terms: Mice, Inbred C57BL
  11. George A, Ng CP, O'Callaghan M, Jensen GS, Wong HJ
    PMID: 24886679 DOI: 10.1186/1472-6882-14-161
    Polygonum minus Huds.is a culinary flavouring that is common in South East Asian cuisine and as a remedy for diverse maladies ranging from indigestion to poor eyesight. The leaves of this herb have been reported to be high in antioxidants. Flavonoids which have been associated with memory, cognition and protection against neurodegeneration were found in P. minus.
    Matched MeSH terms: Mice, Inbred C57BL
  12. Kanagasabapathy G, Kuppusamy UR, Abd Malek SN, Abdulla MA, Chua KH, Sabaratnam V
    PMID: 23259700 DOI: 10.1186/1472-6882-12-261
    BACKGROUND: Pleurotus sajor-caju (P. sajor-caju) has been extremely useful in the prevention of diabetes mellitus due to its low fat and high soluble fiber content for thousands of years. Insulin resistance is a key component in the development of diabetes mellitus which is caused by inflammation. In this study, we aimed to investigate the in vivo efficacy of glucan-rich polysaccharide of P. sajor-caju (GE) against diabetes mellitus and inflammation in C57BL/6J mice fed a high-fat diet.
    METHODS: Diabetes was induced in C57BL/6J mice by feeding a high-fat diet. The mice were randomly assigned to 7 groups (n=6 per group). The control groups in this study were ND (for normal diet) and HFD (for high-fat diet). The treated groups were ND240 (for normal diet) (240 mg/kg b.w) and HFD60, HFD120 and HFD240 (for high-fat), where the mice were administrated with three dosages of GE (60, 120, 240 mg GE/kg b.w respectively). Metformin (2 mg/kg b.w) served as positive control. The glucose tolerance test, glucose and insulin levels were measured at the end of 16 weeks. Expressions of genes for inflammatory markers, GLUT-4 and adiponectin in the adipose tissue of the mice were assessed. One-way ANOVA and Duncan's multiple range tests (DMRT) were used to determine the significant differences between groups.
    RESULTS: GE treated groups improved the glucose tolerance, attenuated hyperglycemia and hyperinsulinemia in the mice by up-regulating the adiponectin and GLUT-4 gene expressions. The mice in GE treated groups did not develop insulin resistance. GE also down-regulated the expression of inflammatory markers (IL-6, TNF-α, SAA2, CRP and MCP-1) via attenuation of nuclear transcription factors (NF-κB).
    CONCLUSION: Glucan-rich polysaccharide of P. sajor-caju can serve as a potential agent for prevention of glucose intolerance, insulin resistance and inflammation.
    Matched MeSH terms: Mice, Inbred C57BL
  13. Ling KH, Hewitt CA, Tan KL, Cheah PS, Vidyadaran S, Lai MI, et al.
    BMC Genomics, 2014;15:624.
    PMID: 25052193 DOI: 10.1186/1471-2164-15-624
    The Ts1Cje mouse model of Down syndrome (DS) has partial triplication of mouse chromosome 16 (MMU16), which is partially homologous to human chromosome 21. These mice develop various neuropathological features identified in DS individuals. We analysed the effect of partial triplication of the MMU16 segment on global gene expression in the cerebral cortex, cerebellum and hippocampus of Ts1Cje mice at 4 time-points: postnatal day (P)1, P15, P30 and P84.
    Matched MeSH terms: Mice, Inbred C57BL
  14. Movahed E, Cheok YY, Tan GMY, Lee CYQ, Cheong HC, Velayuthan RD, et al.
    BMC Immunol, 2018 Nov 08;19(1):32.
    PMID: 30409128 DOI: 10.1186/s12865-018-0269-5
    BACKGROUND: IL-17A has emerged as a key player in the pathologies of inflammation, autoimmune disease, and immunity to microbes since its discovery two decades ago. In this study, we aim to elucidate the activity of IL-17A in the protection against Cryptococcus neoformans, an opportunistic fungus that causes fatal meningoencephalitis among AIDS patients. For this purpose, we examined if C. neoformans infection triggers IL-17A secretion in vivo using wildtype C57BL/6 mice. In addition, an enhanced green fluorescence protein (EGFP) reporter and a knockout (KO) mouse models were used to track the source of IL-17A secretion and explore the protective function of IL-17A, respectively.

    RESULTS: Our findings showed that in vivo model of C. neoformans infection demonstrated induction of abundant IL-17A secretion. By examining the lung bronchoalveolar lavage fluid (BALF), mediastinal lymph node (mLN) and spleen of the IL-17A-EGFP reporter mice, we showed that intranasal inoculation with C. neoformans promoted leukocytes lung infiltration. A large proportion (~ 50%) of the infiltrated CD4+ helper T cell population secreted EGFP, indicating vigorous TH17 activity in the C. neoformans-infected lung. The infection study in IL-17A-KO mice, on the other hand, revealed that absence of IL-17A marginally boosted fungal burden in the lung and accelerated the mouse death.

    CONCLUSION: Therefore, our data suggest that IL-17A is released predominantly from TH17 cells in vivo, which plays a supporting role in the protective immunity against C. neoformans infection.

    Matched MeSH terms: Mice, Inbred C57BL
  15. Li L, Su Y, Li F, Wang Y, Ma Z, Li Z, et al.
    BMC Microbiol, 2020 03 24;20(1):65.
    PMID: 32209070 DOI: 10.1186/s12866-020-01754-2
    BACKGROUND: It has recently been reported that intermittent fasting shapes the gut microbiota to benefit health, but this effect may be influenced to the exact fasting protocols. The purpose of this study was to assess the effects of different daily fasting hours on shaping the gut microbiota in mice. Healthy C57BL/6 J male mice were subjected to 12, 16 or 20 h fasting per day for 1 month, and then fed ad libitum for an extended month. Gut microbiota was analyzed by 16S rRNA gene-based sequencing and food intake was recorded as well.

    RESULTS: We found that cumulative food intake was not changed in the group with 12 h daily fasting, but significantly decreased in the 16 and 20 h fasting groups. The composition of gut microbiota was altered by all these types of intermittent fasting. At genus level, 16 h fasting led to increased level of Akkermansia and decreased level of Alistipes, but these effects disappeared after the cessation of fasting. No taxonomic differences were identified in the other two groups.

    CONCLUSIONS: These data indicated that intermittent fasting shapes gut microbiota in healthy mice, and the length of daily fasting interval may influence the outcome of intermittent fasting.

    Matched MeSH terms: Mice, Inbred C57BL
  16. Bala U, Tan KL, Ling KH, Cheah PS
    BMC Res Notes, 2014;7:714.
    PMID: 25304607 DOI: 10.1186/1756-0500-7-714
    Over the past several decades, many studies concerning peripheral nerve damage or regeneration have been performed. Mice have been widely used for many of these studies, with the sciatic nerve being the most targeted and preferred nerve. Therefore, techniques for harvesting mouse sciatic nerves of a maximum length that is sufficient for different analyses will be highly valuable. Here we describe a simple step-by-step guide for harvesting the maximum length of mouse sciatic nerve and compare the length of the harvested nerves gathered with the proposed method with nerves obtained using a conventional mid-thigh incision approach.
    Matched MeSH terms: Mice, Inbred C57BL
  17. Rahmah N, Khairul Anuar A
    Biochem Biophys Res Commun, 1992 Dec 15;189(2):640-4.
    PMID: 1472034
    Mice were chronically infected with cysts of ME49 strain of Toxoplasma gondii. At different periods post-infection, their spleens were removed and single cell suspensions were made. Lymphocyte transformation experiments were performed on the lymphocyte suspensions using three different kinds of antigens of ME49 strain of T. gondii, namely soluble, excretory/secretory and cystic forms. The results showed that the pattern of lymphocyte responsiveness was dependent on the kind of antigen employed for induction of the blastogenesis. Using soluble and cystic forms of the antigen, different periods of lymphocyte suppression and lymphocyte proliferation were demonstrated. However, with the use of excretory/secretory antigen, no significant suppression of lymphocyte stimulation was noted throughout the course of infection. Thus excretory/secretory antigen may be the best form of antigen for stimulation of the cell-mediated immune response and hence it appears to be a good candidate for vaccine in toxoplasmosis.
    Matched MeSH terms: Mice, Inbred C57BL
  18. Rahmah N, Anuar AK
    Biochem Biophys Res Commun, 1992 Aug 31;187(1):294-8.
    PMID: 1520310
    C57BL/6 mice were orally infected with different doses of cysts of ME49 strain of Toxoplasma gondii to produce groups of acutely and chronically infected mice. Sera were obtained at different periods post-infection. SDS-PAGE was ran with excretory/secretory antigens of ME49 and RH strains of T. gondii, followed by Western blot analyses using the above sera and anti- IgA, IgM, IgG as conjugates. The SDS-PAGE profiles of the two antigens were similar. However the antigenic bands showed variations in all blots, most evidently in IgA blots of chronic sera. IgG blots showed greatest similarities in reactive bands. In IgM blots, more common bands were shown in chronic sera than in acute sera. Variations and similarities in prominence of some bands and time of their appearance were also noted, especially in IgM and IgG blots of chronic sera. Thus antigenic variations and similarities are present in excretory/secretory products of different strains of T. gondii.
    Matched MeSH terms: Mice, Inbred C57BL
  19. Choy KW, Mustafa MR, Lau YS, Liu J, Murugan D, Lau CW, et al.
    Biochem Pharmacol, 2016 09 15;116:51-62.
    PMID: 27449753 DOI: 10.1016/j.bcp.2016.07.013
    Endoplasmic reticulum (ER) stress in endothelial cells often leads to endothelial dysfunction which underlies the pathogenesis of cardiovascular diseases. Paeonol, a major phenolic component extracted from Moutan Cortex, possesses various medicinal benefits which have been used extensively in traditional Chinese medicine. The present study investigated the protective mechanism of paeonol against tunicamycin-induced ER stress in isolated mouse aortas and human umbilical vein endothelial cells (HUVECs). Vascular reactivity in aorta was measured using a wire myograph. The effects of paeonol on protein expression of ER stress markers, reactive oxygen species (ROS) production, nitric oxide (NO) bioavailability and peroxisome proliferator-activated receptor δ (PPARδ) activity in the vascular wall were assessed by Western blot, dihydroethidium fluorescence (DHE) or lucigenin enhanced-chemiluminescence, 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM DA) and dual luciferase reporter assay, respectively. Ex vivo treatment with paeonol (0.1μM) for 16h reversed the impaired endothelium-dependent relaxations in C57BJ/6J and PPARδ wild type (WT) mouse aortas following incubation with tunicamycin (0.5μg/mL). Elevated ER stress markers, oxidative stress and reduction of NO bioavailability induced by tunicamycin in HUVECs, C57BJ/6J and PPARδ WT mouse aortas were reversed by paeonol treatment. These beneficial effects of paeonol were diminished in PPARδ knockout (KO) mouse aortas. Paeonol increased the expression of 5' adenosine monophosphate-activated protein kinase (AMPK) and PPARδ expression and activity while restoring the decreased phosphorylation of eNOS. The present study delineates that paeonol protects against tunicamycin-induced vascular endothelial dysfunction by inhibition of ER stress and oxidative stress, thus elevating NO bioavailability via the AMPK/PPARδ signaling pathway.
    Matched MeSH terms: Mice, Inbred C57BL
  20. Ling WC, Liu J, Lau CW, Murugan DD, Mustafa MR, Huang Y
    Biochem Pharmacol, 2017 Jul 15;136:76-85.
    PMID: 28396195 DOI: 10.1016/j.bcp.2017.04.007
    Salvianolic acid B (Sal B) is one of the most abundant phenolic acids derived from the root of Danshen with potent anti-oxidative properties. The present study examined the vasoprotective effect of Sal B in hypertensive mice induced by angiotensin II (Ang II). Sal B (25mg/kg/day) was administered via oral gavage for 11days to Ang II (1.2mg/kg/day)-infused C57BL/6J mice (8-10weeks old). The vascular reactivity (both endothelium-dependent relaxations and contractions) in mouse arteries was examined by wire myography. The production of reactive oxygen species (ROS), protein level and localization of angiotensin AT1 receptors and the proteins involved in ROS formation were evaluated using dihydroethidium (DHE) fluorescence, lucigenin-enhanced chemiluminescence, immunohistochemistry and Western blotting, respectively. The changes of ROS generating proteins were also assessed in vitro in human umbilical vein endothelial cells (HUVECs) exposed to Ang II with and without co-treatment with Sal B (0.1-10nM). Oral administration of Sal B reversed the Ang II-induced elevation of arterial systolic blood pressure in mice, augmented the impaired endothelium-dependent relaxations and attenuated the exaggerated endothelium-dependent contractions in both aortas and renal arteries of Ang II-infused mice. In addition, Sal B treatment normalized the elevated levels of AT1 receptors, NADPH oxidase subunits (NOx-2 and NOx-4) and nitrotyrosine in arteries of Ang II-infused mice or in Ang II-treated HUVECs. In summary, the present study provided additional evidence demonstrating that Sal B treatment for 11days reverses the impaired endothelial function and with a marked inhibition of AT1 receptor-dependent vascular oxidative stress. This vasoprotective and anti-oxidative action of Sal B most likely contributes to the anti-hypertensive action of the plant-derived compound.
    Matched MeSH terms: Mice, Inbred C57BL
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