Publications by authors named "Yee Kwan Chan"

Strategies to enhance autophagy flux have been suggested to improve outcomes in cardiac ischemic models. We explored the role of adiponectin in mediating cardiac autophagy under ischemic conditions induced by permanent coronary artery ligation. We studied the molecular mechanisms underlying adiponectin's cardio-protective effects in adiponectin knockout (Ad-KO) compared with wild-type (WT) mice subjected to ischemia by coronary artery ligation and H9c2 cardiomyocyte cell line exposed to hypoxia.

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The dynamics of the tripartite relationship between the host, gut bacteria and diet in the gut is relatively unknown. An imbalance between harmful and protective gut bacteria, termed dysbiosis, has been linked to many diseases and has most often been attributed to high-fat dietary intake. However, we recently clarified that the type of fat, not calories, were important in the development of murine colitis.

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Background: Atherosclerosis appears to have multifactorial causes - microbial component like lipopolysaccharides (LPS) and other pathogen associated molecular patterns may be plausible factors. The gut microbiota is an ample source of such stimulants, and its dependent metabolites and altered gut metagenome has been an established link to atherosclerosis. In this exploratory pilot study, we aimed to elucidate whether microbial intervention with probiotics L.

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Lipocalin-2 (Lcn2; also termed neutrophil gelatinase-associated lipocalin (NGAL)) levels correlate positively with heart failure (HF) yet mechanisms via which Lcn2 contributes to the pathogenesis of HF remain unclear. In this study, we used coronary artery ligation surgery to induce ischemia in wild-type (wt) mice and this induced a significant increase in myocardial Lcn2. We then compared wt and Lcn2 knockout (KO) mice and observed that wt mice showed greater ischemia-induced caspase-3 activation and DNA damage measured by TUNEL than Lcn2KO mice.

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Atherosclerosis results from chronic inflammation potentially caused by translocation of bacterial components from the oro-gastrointestinal tract to circulation. Specific probiotics have anti-inflammatory effects and may reduce bacterial translocation. We thereby tested whether a probiotic mixture with documented anti-inflammatory potential could reduce atherosclerosis.

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Lipocalin-2 (Lcn2; also known as neutrophil gelatinase associated lipocalin, NGAL) levels are increased in obesity and diabetes and associate with insulin resistance. Correlations exist between Lcn2 levels and various forms or stages of heart failure. Insulin resistance and autophagy both play well-established roles in cardiomyopathy.

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Dietary lipids modulate immunity, yet the means by which specific fatty acids affect infectious disease susceptibility remains unclear. Deciphering lipid-induced immunity is critical to understanding the balance required for protecting against pathogens while avoiding chronic inflammatory diseases. To understand how specific lipids alter susceptibility to enteric infection, we fed mice isocaloric, high-fat diets composed of corn oil (rich in n-6 polyunsaturated fatty acids [n-6 PUFAs]), olive oil (rich in monounsaturated fatty acids), or milk fat (rich in saturated fatty acids) with or without fish oil (rich in n-3 PUFAs).

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Neutrophil gelatinase-associated lipocalin (NGAL) has recently become established as an important contributor to the pathophysiology of cardiovascular disease. Accordingly, it is now viewed as an attractive candidate as a biomarker for various disease states, and in particular has recently become regarded as one of the best diagnostic biomarkers available for acute kidney injury. Nevertheless, the precise physiological effects of NGAL on the heart and the significance of their alterations during the development of heart failure are only now beginning to be characterized.

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Accumulating evidence supports that the intestinal microbiome is involved in Type 1 diabetes (T1D) pathogenesis through the gut-pancreas nexus. Our aim was to determine whether the intestinal microbiota in the non-obese diabetic (NOD) mouse model played a role in T1D through the gut. To examine the effect of the intestinal microbiota on T1D onset, we manipulated gut microbes by: (1) the fecal transplantation between non-obese diabetic (NOD) and resistant (NOR) mice and (2) the oral antibiotic and probiotic treatment of NOD mice.

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The association between obesity and heart failure is well documented and recent studies have indicated that understanding the physiological role of autophagy will be of great significance. Cardiomyocyte apoptosis is one component of cardiac remodeling which leads to heart failure and in this study we used palmitate-treated H9c2 cells as an in vitro model of lipotoxicity to investigate the role of autophagy in cell death. Temporal analysis revealed that palmitate (100 μM) treatment induced a gradual increase of intracellular lipid accumulation as well as apoptotic cell death.

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Peroxynitrite (ONOO(-)), the product of a radical combination reaction of nitric oxide and superoxide, is a potent biological oxidant involved in a broad spectrum of physiological and pathological processes. Herein we report the development, characterization, and biological applications of a new fluorescent probe, HKGreen-4, for peroxynitrite detection and imaging. HKGreen-4 utilizes a peroxynitrite-triggered oxidative N-dearylation reaction to achieve an exceptionally sensitive and selective fluorescence turn-on response toward peroxynitrite in chemical systems and biological samples.

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Various disease states are associated with an imbalance of protective and pathogenic bacteria in the gut, termed dysbiosis. Current evidence reveals that dietary factors affect the microbial ecosystem in the gut. Changes to community structure of the intestinal microbiota are not without consequence considering the wide effects that the microbes have on both local and systemic immunity.

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Background: Adiponectin regulates glucose and fatty-acid metabolism but its role in chronic graft rejection mediated by Th2 cytokines remains ill-defined.

Methodology/principal Findings: Wild type and adiponectin-null mice were used as graft recipients in mouse MHC class II disparate cardiac transplantation (bm12 toB6) and the graft rejection was monitored. In adiponectin-null mice we observed that the cellular infiltrate of eosinophils, CD4(+) and CD8(+) T cells was reduced in grafts compared to the controls as was collagen deposition and vessel occlusion.

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Background: Melamine-tainted food can induce kidney stones both in humans and animals and in domestic animals, severe cases caused acute kidney failure and death. Although increasing water intake can ameliorate kidney stone formation, its effect on melamine (Mel)-induced kidney stones has not been studied.

Methods: We have analysed the effect of restricted ingestion of drinking water on melamine stone formation in mice.

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