Displaying publications 21 - 40 of 172 in total

Abstract:
Sort:
  1. Clarke K, Ricciardi S, Pearson T, Bharudin I, Davidsen PK, Bonomo M, et al.
    Cell Rep, 2017 Nov 07;21(6):1507-1520.
    PMID: 29117557 DOI: 10.1016/j.celrep.2017.10.040
    Regular endurance training improves muscle oxidative capacity and reduces the risk of age-related disorders. Understanding the molecular networks underlying this phenomenon is crucial. Here, by exploiting the power of computational modeling, we show that endurance training induces profound changes in gene regulatory networks linking signaling and selective control of translation to energy metabolism and tissue remodeling. We discovered that knockdown of the mTOR-independent factor Eif6, which we predicted to be a key regulator of this process, affects mitochondrial respiration efficiency, ROS production, and exercise performance. Our work demonstrates the validity of a data-driven approach to understanding muscle homeostasis.
    Matched MeSH terms: Mice, Inbred C57BL
  2. Subramaniam S, Ong KC, Sabaratnam V, Chua KH, Kuppusamy UR
    Int J Med Mushrooms, 2023;25(4):27-42.
    PMID: 37075082 DOI: 10.1615/IntJMedMushrooms.2023047595
    Ganoderma neo-japonicum Imazeki is a medicinal mushroom consumed by the indigenous people in Malaysia as a remedy for diabetes. This study aims to validate the efficacy of G. neo-japonicum polysaccharides (GNJP) on obesity-induced type 2 diabetes mellitus (T2DM) in C57BL/6J mice. Mice were divided into seven groups; normal diet (ND)-control, high-fat-diet (HFD)-control, HFDGNJP-treated (50, 100, 200 mg/kg b.w.), HFDMET (metformin 50 mg/kg; positive-control) and ND-GNJP (200 mg/kg b.w.). Mice were administered GNJP or metformin orally for 10 weeks (thrice/week) and sacrificed after an oral glucose tolerance test. Body weight, serum biochemicals, liver histology, adipocyte gene expressions, glucose and insulin levels were measured. HFD caused obesity, dyslipidemia, and diabetes in the untreated groups. GNJP (50 mg/kg b.w.) supplementation prevented weight gain and liver steatosis, improved serum lipid profile and glucose tolerance and attenuated hyperglycemia and hyperinsulinemia more effectively when compared with the other treatment groups. The prevention of obesity and lipid dysregulation is plausibly attributed to the increased hormone-sensitive lipase and reduced Akt-1 and Ppary gene expressions while the up-regulation of AdipoQ (adiponectin), Prkag2 and Slc2a4 genes served to sensitize insulin and improve glucose uptake. Thus, supplementation with an appropriate dose of GNJP has promising efficacies in preventing HFD aka obesity-induced T2DM and associated metabolic abnormalities.
    Matched MeSH terms: Mice, Inbred C57BL
  3. O'Rielly R, Li H, Lim SM, Yazbeck R, Kritas S, Ullrich SS, et al.
    Nutrients, 2020 Aug 14;12(8).
    PMID: 32823899 DOI: 10.3390/nu12082446
    Chronic isoleucine supplementation prevents diet-induced weight gain in rodents. Acute-isoleucine administration improves glucose tolerance in rodents and reduces postprandial glucose levels in humans. However, the effect of chronic-isoleucine supplementation on body weight and glucose tolerance in obesity is unknown. This study aimed to investigate the impact of chronic isoleucine on body weight gain and glucose tolerance in lean and high-fat-diet (HFD) induced-obese mice. Male C57BL/6-mice, fed a standard-laboratory-diet (SLD) or HFD for 12 weeks, were randomly allocated to: (1) Control: Drinking water; (2) Acute: Drinking water with a gavage of isoleucine (300 mg/kg) prior to the oral-glucose-tolerance-test (OGTT) or gastric-emptying-breath-test (GEBT); (3) Chronic: Drinking water with 1.5% isoleucine, for a further six weeks. At 16 weeks, an OGTT and GEBT was performed and at 17 weeks metabolic monitoring. In SLD- and HFD-mice, there was no difference in body weight, fat mass, and plasma lipid profiles between isoleucine treatment groups. Acute-isoleucine did not improve glucose tolerance in SLD- or HFD-mice. Chronic-isoleucine impaired glucose tolerance in SLD-mice. There was no difference in gastric emptying between any groups. Chronic-isoleucine did not alter energy intake, energy expenditure, or respiratory quotient in SLD- or HFD-mice. In conclusion, chronic isoleucine supplementation may not be an effective treatment for obesity or glucose intolerance.
    Matched MeSH terms: Mice, Inbred C57BL
  4. Kusamoto A, Harada M, Azhary JMK, Kunitomi C, Nose E, Koike H, et al.
    FASEB J, 2021 11;35(11):e21971.
    PMID: 34653284 DOI: 10.1096/fj.202101051R
    It has been recently recognized that prenatal androgen exposure is involved in the development of polycystic ovary syndrome (PCOS) in adulthood. In addition, the gut microbiome in adult patients and rodents with PCOS differs from that of healthy individuals. Moreover, recent studies have suggested that the gut microbiome may play a causative role in the pathogenesis of PCOS. We wondered whether prenatal androgen exposure induces gut microbial dysbiosis early in life and is associated with the development of PCOS in later life. To test this hypothesis, we studied the development of PCOS-like phenotypes in prenatally androgenized (PNA) female mice and compared the gut microbiome of PNA and control offspring from 4 to 16 weeks of age. PNA offspring showed a reproductive phenotype from 6 weeks and a metabolic phenotype from 12 weeks of age. The α-diversity of the gut microbiome of the PNA group was higher at 8 weeks and lower at 12 and 16 weeks of age, and the β-diversity differed from control at 8 weeks. However, a significant difference in the composition of gut microbiome between the PNA and control groups was already apparent at 4 weeks. Allobaculum and Roseburia were less abundant in PNA offspring, and may therefore be targets for future interventional studies. In conclusion, abnormalities in the gut microbiome appear as early as or even before PCOS-like phenotypes develop in PNA mice. Thus, the gut microbiome in early life is a potential target for the prevention of PCOS in later life.
    Matched MeSH terms: Mice, Inbred C57BL
  5. Liu G, Haw TJ, Starkey MR, Philp AM, Pavlidis S, Nalkurthi C, et al.
    Nat Commun, 2023 Nov 14;14(1):7349.
    PMID: 37963864 DOI: 10.1038/s41467-023-42913-z
    Toll-like receptor 7 (TLR7) is known for eliciting immunity against single-stranded RNA viruses, and is increased in both human and cigarette smoke (CS)-induced, experimental chronic obstructive pulmonary disease (COPD). Here we show that the severity of CS-induced emphysema and COPD is reduced in TLR7-deficient mice, while inhalation of imiquimod, a TLR7-agonist, induces emphysema without CS exposure. This imiquimod-induced emphysema is reduced in mice deficient in mast cell protease-6, or when wild-type mice are treated with the mast cell stabilizer, cromolyn. Furthermore, therapeutic treatment with anti-TLR7 monoclonal antibody suppresses CS-induced emphysema, experimental COPD and accumulation of pulmonary mast cells in mice. Lastly, TLR7 mRNA is increased in pre-existing datasets from patients with COPD, while TLR7+ mast cells are increased in COPD lungs and associated with severity of COPD. Our results thus support roles for TLR7 in mediating emphysema and COPD through mast cell activity, and may implicate TLR7 as a potential therapeutic target.
    Matched MeSH terms: Mice, Inbred C57BL
  6. Bukhari SNA, Hussain F, Thu HE, Hussain Z
    J Integr Med, 2019 Jan;17(1):38-45.
    PMID: 30139656 DOI: 10.1016/j.joim.2018.08.003
    OBJECTIVE: The present study explored the effects of the combined herbal therapy consisting of curcumin (CUR) and Fructus Ligustri Lucidi (FLL) on aspects of bone regeneration.

    METHODS: Prior to analyzing the ability of this novel combined herbal therapy to promote aspects of bone regeneration, its cytotoxicity was determined using MC3T3-E1 cells (pre-osteoblast model). Cell proliferation was evaluated using phase-contrast microscopy and cell differentiation was estimated using alkaline phosphatase activity. The effect of the combined herbal therapy (CUR + FLL) was also assessed in terms of mineralization in the extracellular matrix (ECM) of cultured cells. Further, to explore the molecular mechanisms of bone formation, time-dependent expression of bone-regulating protein biomarkers was also evaluated.

    RESULTS: Combined herbal therapy (CUR + FLL) significantly upregulated the viability, proliferation and differentiation of MC3T3-E1 cells compared to the monotherapy of CUR or FLL. The magnitude of ECM mineralization (calcium deposition) was also higher in MC3T3-E1 cells treated with combined therapy. The time-dependent expression of bone-forming protein biomarkers revealed that the tendency of expression of these bone-regulating proteins was remarkably higher in cells treated with combined therapy.

    CONCLUSION: The co-administration of CUR and FLL had superior promotion of elements of bone regeneration in cultured cells, thus could be a promising alternative herbal therapy for the management of bone erosive disorders such as osteoporosis.

    Matched MeSH terms: Mice, Inbred C57BL
  7. Mot YY, Othman I, Sharifah SH
    Stem Cell Res Ther, 2017 01 23;8(1):5.
    PMID: 28114965 DOI: 10.1186/s13287-016-0457-2
    BACKGROUND: Mesenchymal stromal cells (MSCs) and Ophiophagus hannah L-amino acid oxidase (Oh-LAAO) have been reported to exhibit antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Published data have indicated that synergistic antibacterial effects could be achieved by co-administration of two or more antimicrobial agents. However, this hypothesis has not been proven in a cell- and protein-based combination. In this study, we investigate if co-administration of adipose-derived MSCs and Oh-LAAO into a mouse model of MRSA-infected wounds would be able to result in a synergistic antibacterial effect.

    METHODS: MSCs and Oh-LAAO were isolated and characterized by standard methodologies. The effects of the experimental therapies were evaluated in C57/BL6 mice. The animal study groups consisted of full-thickness uninfected and MRSA-infected wound models which received Oh-LAAO, MSCs, or both. Oh-LAAO was administered directly on the wound while MSCs were delivered via intradermal injections. The animals were housed individually with wound measurements taken on days 0, 3, and 7. Histological analyses and bacterial enumeration were performed on wound biopsies to determine the efficacy of each treatment.

    RESULTS: Immunophenotyping and differentiation assays conducted on isolated MSCs indicated expression of standard cell surface markers and plasticity which corresponds to published data. Characterization of Oh-LAAO by proteomics, enzymatic, and antibacterial assays confirmed the identity, purity, and functionality of the enzyme prior to use in our subsequent studies. Individual treatments with MSCs and Oh-LAAO in the infected model resulted in reduction of MRSA load by one order of magnitude to the approximate range of 6 log10 colony-forming units (CFU) compared to untreated controls (7.3 log10 CFU). Similar wound healing and improvements in histological parameters were observed between the two groups. Co-administration of MSCs and Oh-LAAO reduced bacterial burden by approximately two orders of magnitude to 5.1 log10 CFU. Wound closure measurements and histology analysis of biopsies obtained from the combinational therapy group indicated significant enhancement in the wound healing process compared to all other groups.

    CONCLUSIONS: We demonstrated that co-administration of MSCs and Oh-LAAO into a mouse model of MRSA-infected wounds exhibited a synergistic antibacterial effect which significantly reduced the bacterial count and accelerated the wound healing process.

    Matched MeSH terms: Mice, Inbred C57BL
  8. Dups J, Middleton D, Long F, Arkinstall R, Marsh GA, Wang LF
    Virol J, 2014;11:102.
    PMID: 24890603 DOI: 10.1186/1743-422X-11-102
    Nipah virus and Hendra virus are closely related and following natural or experimental exposure induce similar clinical disease. In humans, encephalitis is the most serious outcome of infection and, hitherto, research into the pathogenesis of henipavirus encephalitis has been limited by the lack of a suitable model. Recently we reported a wild-type mouse model of Hendra virus (HeV) encephalitis that should facilitate detailed investigations of its neuropathogenesis, including mechanisms of disease recrudescence. In this study we investigated the possibility of developing a similar model of Nipah virus encephalitis.
    Matched MeSH terms: Mice, Inbred C57BL
  9. Lee YY, Tang TK, Phuah ET, Karim NAA, Alitheen NBM, Tan CP, et al.
    Food Res Int, 2018 01;103:200-207.
    PMID: 29389606 DOI: 10.1016/j.foodres.2017.10.022
    Medium-and-Long Chain Triacylglycerol (MLCT) is a type of structured lipid that is made up of medium chain, MCFA (C8-C12) and long chain, LCFA (C16-C22) fatty acid. Studies claimed that consumption of MLCT has the potential in reducing visceral fat accumulation as compared to long chain triacylglycerol, LCT. This is mainly attributed to the rapid metabolism of MCFA as compared to LCFA. Our study was designed to compare the anti-obesity effects of a enzymatically interesterified MLCT (E-MLCT) with physical blend of palm kernel and palm oil (B-PKOPO) having similar fatty acid composition and a commercial MLCT (C-MLCT) made of rapeseed/soybean oil on Diet Induced Obesity (DIO) C57BL/6J mice for a period of four months in low fat, LF (7%) and high fat, HF (30%) diet. The main aim was to determine if the anti-obesity effect of MLCT was contributed solely by its triacylglycerol structure alone or its fatty acid composition or both. Out of the three types of MLCT, mice fed with Low Fat, LF (7%) E-MLCT had significantly (P<0.05) lower body weight gain (by ~30%), body fat accumulation (by ~37%) and hormone leptin level as compared to both the LF B-PKOPO and LF C-MLCT. Histological examination further revealed that dietary intake of E-MLCT inhibited hepatic lipid accumulation. Besides, analysis of serum profile also demonstrated that consumption of E-MLCT was better in regulating blood glucose compared to B-PKOPO and C-MLCT. Nevertheless, both B-PKO-PO and E-MLCT which contained higher level of myristic acid was found to be hypercholesterolemic compared to C-MLCT. In summary, our finding showed that triacylglycerol structure, fatty acid composition and fat dosage play a pivotal role in regulating visceral fat accumulation. Consumption of E-MLCT in low fat diet led to a significantly lesser body fat accumulation. It was postulated that the MLM/MLL/LMM/MML/LLM types of triacylglycerol and C8-C12 medium chain fatty acids were the main factors that contributed to the visceral fat suppressing effect of MLCT. Despite being able to reduce body fat, the so called healthful functional oil E-MLCT when taken in high amount do resulted in fat accumulation. In summary, E-MLCT when taken in moderation can be used to manage obesity issue. However, consumption of E-MLCT may lead to higher total cholesterol and LDL level.
    Matched MeSH terms: Mice, Inbred C57BL
  10. Gouk SW, Cheng SF, Ong AS, Chuah CH
    Br J Nutr, 2014 Apr 14;111(7):1174-80.
    PMID: 24286356 DOI: 10.1017/S0007114513003668
    In the present study, we investigated the effect of long-acyl chain SFA, namely palmitic acid (16:0) and stearic acid (18:0), at sn-1, 3 positions of TAG on obesity. Throughout the 15 weeks of the experimental period, C57BL/6 mice were fed diets fortified with cocoa butter, sal stearin (SAL), palm mid fraction (PMF) and high-oleic sunflower oil (HOS). The sn-1, 3 positions were varied by 16:0, 18:0 and 18:1, whilst the sn-2 position was preserved with 18:1. The HOS-enriched diet was found to lead to the highest fat deposition. This was in accordance with our previous postulation. Upon normalisation of total fat deposited with food intake to obtain the fat:feed ratio, interestingly, mice fed the SAL-enriched diet exhibited significantly lower visceral fat/feed and total fat/feed compared with those fed the PMF-enriched diet, despite their similarity in SFA-unsaturated fatty acid-SFA profile. That long-chain SFA at sn-1, 3 positions concomitantly with an unsaturated FA at the sn-2 position exert an obesity-reducing effect was further validated. The present study is the first of its kind to demonstrate that SFA of different chain lengths at sn-1, 3 positions exert profound effects on fat accretion.
    Matched MeSH terms: Mice, Inbred C57BL
  11. Chow WZ, Ong LK, Kluge MG, Gyawali P, Walker FR, Nilsson M
    Sci Rep, 2020 Nov 11;10(1):19545.
    PMID: 33177588 DOI: 10.1038/s41598-020-76560-x
    For many chronic stroke survivors, persisting cognitive dysfunction leads to significantly reduced quality of life. Translation of promising therapeutic strategies aimed at improving cognitive function is hampered by existing, disparate cognitive assessments in animals and humans. In this study, we assessed post-stroke cognitive function using a comparable touchscreen-based paired-associate learning task in a cross-sectional population of chronic stroke survivors (≥ 5 months post-stroke, n = 70), age-matched controls (n = 70), and in mice generated from a C57BL/6 mouse photothrombotic stroke model (at six months post-stroke). Cognitive performance of stroke survivors was analysed using linear regression adjusting for age, gender, diabetes, systolic blood pressure and waist circumference. Stroke survivors made significantly fewer correct choices across all tasks compared with controls. Similar cognitive impairment was observed in the mice post-stroke with fewer correct choices compared to shams. These results highlight the feasibility and potential value of analogous modelling of clinically meaningful cognitive impairments in chronic stroke survivors and in mice in chronic phase after stroke. Implementation of validated, parallel cross-species test platforms for cognitive assessment offer the potential of delivering a more useful framework for evaluating therapies aimed at improving long-term cognitive function post-stroke.
    Matched MeSH terms: Mice, Inbred C57BL
  12. Lee YY, Tang TK, Ab Karim NA, Alitheen NB, Lai OM
    Food Funct, 2014 Jan;5(1):57-64.
    PMID: 24247642 DOI: 10.1039/c3fo60358j
    Structured lipid medium- and long-chain triacylglycerols (MLCT) are claimed to be able to manage obesity. The present study investigated the body fat influence of enzymatically interesterifed palm-based medium- and long-chain triacylglycerols (P-MLCT) on diet-induced obesity (DIO) C57BL/6J mice compared with commercial MLCT oil (C-MLCT) and a control, which was the non enzymatically modified palm kernel and palm oil blend (PKO-PO blend). It also investigated the low fat and high fat effects of P-MLCT. DIO C57BL/6J mice were fed ad libitum with low fat (7%) and high fat (30%) experimental diets for 8 weeks before being sacrificed to obtain blood serum for analysis. From the results, there is a trend that P-MLCT fed mice were found to have the lowest body weight, body weight gain, total fat pad accumulation (perirenal, retroperitoneal, epididymal and mesenteric), total triglyceride levels and efficiency in controlling blood glucose level, compared with C-MLCT and the PKO-PO blend in both low fat and high fat diets. Nevertheless, the PKO-PO blend and P-MLCT caused significantly (P < 0.05) higher total cholesterol levels compared to C-MLCT. P-MLCT present in low fat and high fat dosage were shown to be able to suppress body fat accumulation. This effect is more prominent with the low fat dosage.
    Matched MeSH terms: Mice, Inbred C57BL
  13. Chen L, Jiang Q, Jiang C, Lu H, Hu W, Yu S, et al.
    Food Funct, 2023 Mar 20;14(6):2870-2880.
    PMID: 36883533 DOI: 10.1039/d2fo02524h
    Obesity has been reported to be associated with dysbiosis of gut microbiota. Sciadonic acid (SC) is one of the main functional components of Torreya grandis "Merrillii" seed oil. However, the effect of SC on high-fat diet (HFD)-induced obesity has not been elucidated. In this study, we evaluated the effects of SC on lipid metabolism and the gut flora in mice fed with a high-fat diet. The results revealed that SC activates the PPARα/SREBP-1C/FAS signaling pathway and reduces the levels of total cholesterol (TC), triacylglycerols (TG), and low-density lipoprotein cholesterol (LDL-C), but increases the level of high-density lipoprotein cholesterol (HDL-C) and inhibits weight gain. Among them, high-dose SC was the most effective; the TC, TG and LDL-C levels were reduced by 20.03%, 28.40% and 22.07%, respectively; the HDL-C level was increased by 8.55%. In addition, SC significantly increased glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels by 98.21% and 35.17%, respectively, decreased oxidative stress, and ameliorated the pathological damage to the liver caused by a high-fat diet. Furthermore, SC treatment altered the composition of the intestinal flora, promoting the relative abundance of beneficial bacteria such as Lactobacillus and Bifidobacterium, while simultaneously decreasing the relative abundance of potentially harmful bacteria such as Faecalibaculum, norank_f_Desulfovibrionaceae, and Romboutsia. Spearman's correlation analysis indicated that the gut microbiota was associated with SCFAs and biochemical indicators. In summary, our results suggested that SC can improve lipid metabolism disorders and regulate the gut microbial structure.
    Matched MeSH terms: Mice, Inbred C57BL
  14. Yao S, Lu H, Zhou T, Jiang Q, Jiang C, Hu W, et al.
    Food Funct, 2024 Apr 22;15(8):4490-4502.
    PMID: 38566566 DOI: 10.1039/d3fo04527g
    High-fat diet (HFD) has been associated with certain negative bone-related outcomes, such as bone metabolism disruption and bone loss. Sciadonic acid (SC), one of the main nutritional and functional components of Torreya grandis seed oil, is a unique Δ5-unsaturated-polymethylene-interrupted fatty acid (Δ5-UPIFA) that has been claimed to counteract such disorders owing to some of its physiological effects. However, the role of SC in ameliorating bone metabolism disorders due to HFD remains unclear. In the present investigation, we observed that SC modulates the OPG/RANKL/RANK signaling pathway by modifying the lipid metabolic state and decreasing inflammation in mice. In turn, it could balance bone resorption and formation as well as calcium and phosphorus levels, enhance bone strength and bone mineral density (BMD), and improve its microstructure. In addition, SC could inhibit fat vacuoles in bone, reverse the phenomenon of reduced numbers and poor continuity of bone trabeculae, and promote orderly arrangement of collagen fibers and cartilage repair. This study provides some theoretical basis for SC as a dietary intervention agent to enhance bone nutrition.
    Matched MeSH terms: Mice, Inbred C57BL*
  15. Xu X, Yi C, Feng T, Ge Y, Liu M, Wu C, et al.
    Clin Immunol, 2023 Aug;253:109685.
    PMID: 37406980 DOI: 10.1016/j.clim.2023.109685
    Inducing tumor-specific T cell responses and regulating suppressive tumor microenvironments have been a challenge for effective tumor therapy. CpG (ODN), the Toll-like receptor 9 agonist, has been widely used as adjuvants of cancer vaccines to induce T cell responses. We developed a novel adjuvant to improve the targeting of lymph nodes. CpG were modified with lipid and glycopolymers by the combination of photo-induced RAFT polymerization and click chemistry, and the novel adjuvant was termed as lipid-glycoadjuvant@AuNPs (LCpG). OVA protein was used as model antigen and melanoma model was established to test the immunotherapy effect of the adjuvant. In tumor model, the antitumor effect and mechanism of LCpG on the response of CTLs were examined by flow cytometry and cell cytotoxicity assay. The effects of LCpG on macrophage polarization and Tregs differentiation in tumor microenvironment were also studied by cell depletion assay and cytokine neutralization assay. We also tested the therapeutic effect of the combination of the adjuvant and anti-PD-1 treatment. LCpG could be rapidly transported to and retained longer in the lymphoid nodes than unmodified CpG. In melanoma model, LCpG controlled both primary tumor and its metastasis, and established long-term memory. In spleen and tumor draining lymphoid nodes, LCpG activated tumor-specific Tc1 responses, with increased CD8+ T-cell proliferation, antigen-specific Tc1 cytokine production and specific-tumor killing capacity. In tumor microenvironments, antigen-specific Tc1 induced by the LCpG promoted CTL infiltration, skewed tumor associated macrophages to M1 phenotype, regulated Treg and induced proinflammatory cytokines production in a CTL-derived IFN-γ-dependent manner. In vivo cell depletion and adoptive transfer experiments confirmed that antitumor activity of LCpG included vaccine was mainly dependent on CTL-derived IFN-γ. The anti-tumor efficacy of LCpG was dramatically enhanced when combined with anti-PD1 immunotherapy. LCpG was a promising adjuvant for vaccine formulation which could augment tumor-specific Tc1 activity, and regulate tumor microenvironments.
    Matched MeSH terms: Mice, Inbred C57BL
  16. Housseau F, Wu S, Wick EC, Fan H, Wu X, Llosa NJ, et al.
    Cancer Res, 2016 04 15;76(8):2115-24.
    PMID: 26880802 DOI: 10.1158/0008-5472.CAN-15-0749
    IL17-producing Th17 cells, generated through a STAT3-dependent mechanism, have been shown to promote carcinogenesis in many systems, including microbe-driven colon cancer. Additional sources of IL17, such as γδ T cells, become available under inflammatory conditions, but their contributions to cancer development are unclear. In this study, we modeled Th17-driven colon tumorigenesis by colonizing Min(Ap) (c+/-) mice with the human gut bacterium, enterotoxigenic Bacteroides fragilis (ETBF), to investigate the link between inflammation and colorectal cancer. We found that ablating Th17 cells by knocking out Stat3 in CD4(+) T cells delayed tumorigenesis, but failed to suppress the eventual formation of colonic tumors. However, IL17 blockade significantly attenuated tumor formation, indicating a critical requirement for IL17 in tumorigenesis, but from a source other than Th17 cells. Notably, genetic ablation of γδ T cells in ETBF-colonized Th17-deficient Min mice prevented the late emergence of colonic tumors. Taken together, these findings support a redundant role for adaptive Th17 cell- and innate γδT17 cell-derived IL17 in bacteria-induced colon carcinogenesis, stressing the importance of therapeutically targeting the cytokine itself rather than its cellular sources. Cancer Res; 76(8); 2115-24. ©2016 AACR.
    Matched MeSH terms: Mice, Inbred C57BL
  17. Ahmad S, Valli H, Smyth R, Jiang AY, Jeevaratnam K, Matthews HR, et al.
    J Cell Physiol, 2019 Apr;234(4):3921-3932.
    PMID: 30146680 DOI: 10.1002/jcp.27183
    Peroxisome proliferator-activated receptor-γ coactivator-1 deficient (Pgc-1β-/- ) murine hearts model the increased, age-dependent, ventricular arrhythmic risks attributed to clinical conditions associated with mitochondrial energetic dysfunction. These were accompanied by compromised action potential (AP) upstroke rates and impaired conduction velocities potentially producing arrhythmic substrate. We tested a hypothesis implicating compromised Na+ current in these electrophysiological phenotypes by applying loose patch-clamp techniques in intact young and aged, wild-type (WT) and Pgc-1β-/- , ventricular cardiomyocyte preparations for the first time. This allowed conservation of their in vivo extracellular and intracellular conditions. Depolarising steps elicited typical voltage-dependent activating and inactivating inward Na+ currents with peak amplitudes increasing or decreasing with their respective activating or preceding inactivating voltage steps. Two-way analysis of variance associated Pgc-1β-/- genotype with independent reductions in maximum peak ventricular Na+ currents from -36.63 ± 2.14 (n = 20) and -35.43 ± 1.96 (n = 18; young and aged WT, respectively), to -29.06 ± 1.65 (n = 23) and -27.93 ± 1.63 (n = 20; young and aged Pgc-1β-/- , respectively) pA/μm2 (p 
    Matched MeSH terms: Mice, Inbred C57BL
  18. Valli H, Ahmad S, Fraser JA, Jeevaratnam K, Huang CL
    Exp Physiol, 2017 12 01;102(12):1619-1634.
    PMID: 28960529 DOI: 10.1113/EP086589
    NEW FINDINGS: What is the central question of this study? Can we experimentally replicate atrial pro-arrhythmic phenotypes associated with important chronic clinical conditions, including physical inactivity, obesity, diabetes mellitus and metabolic syndrome, compromising mitochondrial function, and clarify their electrophysiological basis? What is the main finding and its importance? Electrocardiographic and intracellular cardiomyocyte recording at progressively incremented pacing rates demonstrated age-dependent atrial arrhythmic phenotypes in Langendorff-perfused murine Pgc1β-/- hearts for the first time. We attributed these to compromised action potential conduction and excitation wavefronts, whilst excluding alterations in recovery properties or temporal electrophysiological instabilities, clarifying these pro-arrhythmic changes in chronic metabolic disease. Atrial arrhythmias, most commonly manifesting as atrial fibrillation, represent a major clinical problem. The incidence of atrial fibrillation increases with both age and conditions associated with energetic dysfunction. Atrial arrhythmic phenotypes were compared in young (12-16 week) and aged (>52 week) wild-type (WT) and peroxisome proliferative activated receptor, gamma, coactivator 1 beta (Ppargc1b)-deficient (Pgc1β-/- ) Langendorff-perfused hearts, previously used to model mitochondrial energetic disorder. Electrophysiological explorations were performed using simultaneous whole-heart ECG and intracellular atrial action potential (AP) recordings. Two stimulation protocols were used: an S1S2 protocol, which imposed extrasystolic stimuli at successively decremented intervals following regular pulse trains; and a regular pacing protocol at successively incremented frequencies. Aged Pgc1β-/- hearts showed greater atrial arrhythmogenicity, presenting as atrial tachycardia and ectopic activity. Maximal rates of AP depolarization (dV/dtmax ) were reduced in Pgc1β-/- hearts. Action potential latencies were increased by the Pgc1β-/- genotype, with an added interactive effect of age. In contrast, AP durations to 90% recovery (APD90 ) were shorter in Pgc1β-/- hearts despite similar atrial effective recovery periods amongst the different groups. These findings accompanied paradoxical decreases in the incidence and duration of alternans in the aged and Pgc1β-/- hearts. Limiting slopes of restitution curves of APD90 against diastolic interval were correspondingly reduced interactively by Pgc1β-/- genotype and age. In contrast, reduced AP wavelengths were associated with Pgc1β-/- genotype, both independently and interacting with age, through the basic cycle lengths explored, with the aged Pgc1β-/- hearts showing the shortest wavelengths. These findings thus implicate AP wavelength in possible mechanisms for the atrial arrhythmic changes reported here.
    Matched MeSH terms: Mice, Inbred C57BL
  19. Jiang Y, Zhao L, Ma J, Yang Y, Zhang B, Xu J, et al.
    Phytomedicine, 2024 Jan;123:155229.
    PMID: 38006804 DOI: 10.1016/j.phymed.2023.155229
    BACKGROUND: Triphala (TLP), as a Chinese Tibetan medicine composing of Emblica officinalis, Terminalia chebula and Terminalia bellirica (1.2:1.5:1), exhibited hepatoprotective, hypolipidemic and gut microbiota modulatory effects. Nonetheless, its roles in prevention of high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) and the related mechanistic insights involving the interplay of gut microbiota and hepatic inflammation are not known.

    PURPOSE: The present study seeks to determine if TLP would prevent HFD-induced NAFLD in vivo and its underlying mechanisms from the perspectives of gut microbiota, metabolites, and hepatic inflammation.

    METHODS: TLP was subjected to extraction and chemo-profiling, and in vivo evaluation in HFD-fed rats on hepatic lipid and inflammation, intestinal microbiota, short-chain fatty acids (SCFAs) and permeability, and body weight and fat content profiles.

    RESULTS: The TLP was primarily constituted of gallic acid, corilagin and chebulagic acid. Orally administered HFD-fed rats with TLP were characterized by the growth of Ligilactobacillus and Akkermansia, and SCFAs (acetic/propionic/butyric acid) secretion which led to increased claudin-1 and zonula occludens-1 expression that reduced the mucosal permeability to migration of lipopolysaccharides (LPS) into blood and liver. Coupling with hepatic cholesterol and triglyceride lowering actions, the TLP mitigated both inflammatory (ALT, AST, IL-1β, IL-6 and TNF-α) and pro-inflammatory (TLR4, MYD88 and NF-κB P65) activities of liver, and sequel to histopathological development of NAFLD in a dose-dependent fashion.

    CONCLUSION: TLP is promisingly an effective therapy to prevent NAFLD through modulating gut microbiota, mucosal permeability and SCFAs secretion with liver fat and inflammatory responses.

    Matched MeSH terms: Mice, Inbred C57BL
  20. Samuvel DJ, Nguyen NT, Jaeschke H, Lemasters JJ, Wang X, Choo YM, et al.
    J Nat Prod, 2022 Jul 22;85(7):1779-1788.
    PMID: 35815804 DOI: 10.1021/acs.jnatprod.2c00324
    Oxidative stress plays an important role in acetaminophen (APAP)-induced hepatotoxicity. Platanosides (PTSs) isolated from the American sycamore tree (Platanus occidentalis) represent a potential new four-molecule botanical drug class of antibiotics active against drug-resistant infectious disease. Preliminary studies have suggested that PTSs are safe and well tolerated and have antioxidant properties. The potential utility of PTSs in decreasing APAP hepatotoxicity in mice in addition to an assessment of their potential with APAP for the control of infectious diseases along with pain and pyrexia associated with a bacterial infection was investigated. On PTS treatment in mice, serum alanine aminotransferase (ALT) release, hepatic centrilobular necrosis, and 4-hydroxynonenal (4-HNE) were markedly decreased. In addition, inducible nitric oxide synthase (iNOS) expression and c-Jun-N-terminal kinase (JNK) activation decreased when mice overdosed with APAP were treated with PTSs. Computational studies suggested that PTSs may act as JNK-1/2 and Keap1-Nrf2 inhibitors and that the isomeric mixture could provide greater efficacy than the individual molecules. Overall, PTSs represent promising botanical drugs for hepatoprotection and drug-resistant bacterial infections and are effective in protecting against APAP-related hepatotoxicity, which decreases liver necrosis and inflammation, iNOS expression, and oxidative and nitrative stresses, possibly by preventing persistent JNK activation.
    Matched MeSH terms: Mice, Inbred C57BL
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links