Pei-Ying Pai
China Medical University,Taiwan, School of Medicine, Faculty Member
Cardiovascular diseases in post-menopausal women are on a rise. Oxidative stress is the main contributing factor to the etiology and pathogenesis of cardiovascular diseases. Diosgenin, a member of steroidal sapogenin, is structurally... more
Cardiovascular diseases in post-menopausal women are on a rise. Oxidative stress is the main contributing factor to the etiology and pathogenesis of cardiovascular diseases. Diosgenin, a member of steroidal sapogenin, is structurally similar to estrogen and has been shown to have antioxidant effects. Therefore, we aimed to investigate the effects of diosgenin in preventing oxidation-induced cardiomyocyte apoptosis and assessed its potential as a substitute substance for estrogen in post-menopausal women. Apoptotic pathways and mitochondrial membrane potential were measured in H9c2 cardiomyoblast cells and neonatal cardiomyocytes treated with diosgenin for 1[Formula: see text]h prior to hydrogen peroxide (H2O2) stimulation. H2O2-stimulated H9c2 cardiomyoblast cells displayed cytotoxicity and apoptosis via the activation of both Fas-dependent and mitochondria-dependent pathways. Additionally, it led to the instability of the mitochondrial membrane potential. However, the H2O2-induced ...
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We report a rare case of stenotic double-orifice mitral valve of incomplete bridge-type in a 40 year-old female. Transthoracic two-dimensional echocardiography revealed a double-orifice . mitral valve at the leaflet level, with... more
We report a rare case of stenotic double-orifice mitral valve of incomplete bridge-type in a 40 year-old female. Transthoracic two-dimensional echocardiography revealed a double-orifice . mitral valve at the leaflet level, with anterolateral and posteromedial orifices which measured 0.6 and 1.1 cm2 by planimetry, respectively. Color Doppler examination showed separate diastolic flows and trivial regurgitation through each orifice. The fibrous bridge tissue between the leaflets was successfully split using percutaneous Inoue-balloon valvuloplasty with stepwise dilations applied only to the posteromedial orifice. The mitral valve area after the procedure measured 3.0 cm2, Transesophageal echocardiograms with three-dimensional reconstruction also confirmed the presence of a double-orifice mitral valve before and an enlarged single mitral orifice after the valvuloplasty( Mid Taiwan J Med 2002;7:59-64)
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1. Lobbedez T, Crand A, Le Roy F, Landru I, Quéré C, Ryckelynck JP. Transfer from chronic haemodialysis to peritoneal dialysis. Nephrol Ther 2005; 1:38–43. 2. Shea M, Hmiel SP, Beck AM. Use of tissue plasminogen activator for thrombolysis... more
1. Lobbedez T, Crand A, Le Roy F, Landru I, Quéré C, Ryckelynck JP. Transfer from chronic haemodialysis to peritoneal dialysis. Nephrol Ther 2005; 1:38–43. 2. Shea M, Hmiel SP, Beck AM. Use of tissue plasminogen activator for thrombolysis in occluded peritoneal dialysis catheters in children. Adv Perit Dial 2001; 17:249–52. 3. Casonato A, Pontara E, Vertolli UP, Steffan A, Durante C, De Marco L, et al. Plasma and platelet von Willebrand factor abnormalities in patients with uremia: lack of correlation with uremic bleeding. Clin Appl Thromb Hemost 2001; 7:81–6. 4. Couch P, Stumpf JL. Management of uremic bleeding. Clin Pharm 1990; 9:673–81. 5. Kaplan GG, Manns B, McLaughlin K. Heparin induced thrombocytopaenia secondary to intraperitoneal heparin exposure. Nephrol Dial Transplant 2005; 20:2561–2. doi:10.3747/pdi.2009.00204
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Cardiomyopathy involves changes in myocardial ultrastructure and cardiac hypertrophy. Angiotensin II (AngII) has previously been shown to stimulate the expression of IGF-2 and IGF-2R in H9c2 cardiomyoblasts and increase of blood pressure,... more
Cardiomyopathy involves changes in myocardial ultrastructure and cardiac hypertrophy. Angiotensin II (AngII) has previously been shown to stimulate the expression of IGF-2 and IGF-2R in H9c2 cardiomyoblasts and increase of blood pressure, and cardiac hypertrophy. Estrogen receptors (ERs) exert protective effects, such as anti-hypertrophy in cadiomyocytes. Tanshinone IIA (TSN), a main active ingredient from a Chinese medical herb, Salvia miltiorrhiza Bunge (Danshen), was shown to protect cardiomyocytes hypertrophy by different stress signals. We aimed to investigate whether TSN protected H9c2 cardiomyocytes from AngII-induced activation of IGF-2R pathway and hypertrophy by mediating through ERs. AngII resulted in H9c2 cardiomyoblast hypertrophy and increased inflammatory molecular markers. These were down-regulated by TSN via estrogen receptors. AngII resulted in elevation in MAPKs, IGF-2R and hypertrophic protein markers. These, again, were reduced by addition of the phytoestrogen with activation of ERs. Finally, AngII induced phosphorylation of heat shock factor-1 (HSF1) and decreased sirtuin-1 (SIRT1). In addition, AngII also caused an increase in distribution of IGF-2R molecules on cell membrane. In contrast, TSN reduced HSF1 phosphorylation and cell surface IGF-2R while elevating SIRT1 via ERs. TSN was capable of attenuating AngII-induced IGF-2R pathway and hypertrophy through ERs in H9c2 cardiomyoblast cells.
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Hypertension-induced cardiac hypertrophy and attenuated cardiac function are the major characteristics of early stage heart failure. Cardiomyocyte death in pathological cardiac conditions is the primary cause of heart failure and... more
Hypertension-induced cardiac hypertrophy and attenuated cardiac function are the major characteristics of early stage heart failure. Cardiomyocyte death in pathological cardiac conditions is the primary cause of heart failure and mortality. Our previous studies found that heat shock factor 1 (HSF1) protected cardiomyocytes from death by suppressing the IGF-IIR signaling pathway, which is critical for hypertensive angiotensin II-induced cardiomyocyte apoptosis. However, the role of heat shock factor 2 (HSF2) in hypertension-induced cardiac hypertrophy is unknown. We identified HSF2 as a miR-18 target for cardiac hypertrophy. p53 activation in angiotensin II (ANG II)-stimulated NRVMs is responsible for miR-18 downregulation both in vitro and in vivo, which triggers HSF2 expression and the activation of IGF-IIR-induced cardiomyocyte hypertrophy. Finally, we provide genetic evidence that miR-18 is required for cardiomyocyte functions in the heart based on the gene transfer of cardiac-sp...
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Doxorubicin (DOX) is one of the most effective antitumor drugs, but its cardiotoxicity has been a major concern for its use in cancer therapy for decades. Although DOX-induced cardiotoxicity has been investigated, the underlying... more
Doxorubicin (DOX) is one of the most effective antitumor drugs, but its cardiotoxicity has been a major concern for its use in cancer therapy for decades. Although DOX-induced cardiotoxicity has been investigated, the underlying mechanisms responsible for this cardiotoxicity have not been completely elucidated. Here, we found that the insulin-like growth factor receptor II (IGF-IIR) apoptotic signaling pathway was responsible for DOX-induced cardiotoxicity via proteasome-mediated heat shock transcription factor 1 (HSF1) degradation. The carboxyl-terminus of Hsp70 interacting protein (CHIP) mediated HSF1 stability and nuclear translocation through direct interactions via its tetratricopeptide repeat domain to suppress IGF-IIR expression and membrane translocation under physiological conditions. However, DOX attenuated the HSF1 inhibition of IGF-IIR expression by diminishing the CHIP-HSF1 interaction, removing active nuclear HSF1 and triggering HSF1 proteasomal degradation. Overexpres...
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Exposure to second-hand tobacco smoke (SHS) has been epidemiologically linked to heart disease among non-smokers. However, the molecular mechanism behind SHS-induced cardiac disease is not well known. This study found that SD rats exposed... more
Exposure to second-hand tobacco smoke (SHS) has been epidemiologically linked to heart disease among non-smokers. However, the molecular mechanism behind SHS-induced cardiac disease is not well known. This study found that SD rats exposed to cigarette smoke at a dose of 10 cigarettes for 30 min twice a day for 1 month had a reduced left ventricle-to-tibia length ratio (mg/mm), increased cardiomyocyte apoptosis by TUNEL assay and a wider interstitial space by H&E staining. However, lumbrokinase and dilong both reversed the effects of SHS. Western blotting demonstrated significantly increased expression of the pro-apoptotic protein caspase-3 in the hearts of the rats exposed to SHS. Elevated protein expression levels of Fas, FADD and the apoptotic initiator activated caspase-8, a molecule in the death-receptor-dependent pathway, coupled with increased t-Bid and apoptotic initiator activated caspase-9 were found. Molecules in the mitochondria-dependent pathway, which disrupts mitochond...
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Objective: Combination therapy with angiotensin-converting enzyme inhibitors (ACE inhibitors) and angiotensin II receptor blockers (ARB) has been stressed for its comprehensive blocking of the renin-angiotensin-aldosterone (RAAS) system,... more
Objective: Combination therapy with angiotensin-converting enzyme inhibitors (ACE inhibitors) and angiotensin II receptor blockers (ARB) has been stressed for its comprehensive blocking of the renin-angiotensin-aldosterone (RAAS) system, but evidence is lacking in settings like population-based follow-up studies in the real world. Design and Method: This study compared the effectiveness of ACE inhibitors and ARB on stroke prevention in patients with hypertension and type 2 diabetes mellitus. Using Taiwan's National Health Insurance claims data, we identified 5445 subjects aged 18 years and older who had newly diagnosed hypertension in 1997-2010 and then developed type 2 diabetes during the screening period. Among them, 2161 patients took ACE inhibitors, 1703 ARBs alone, 165 both, and 1416 neither. Results: During the follow-up period, stroke incidence rate was lowest (23.02 per 1000 person-years) in the ARB group, followed by the Neither group, the ACEI group and the Both group (24.06, 30.23, and 37.86 per 1000 person-years, respectively). Compared with patients in the Neither group, the adjusted hazard ratios (HRs) were 1.27 (95% CI 1.02–1.58) in the ACEI group, 0.95 (95% CI 0.74–1.22) in the ARB group, and 1.56 (95% CI 0.99–2.47) in the Both group. In a dosage-effect sub-analysis, greater reduction in stroke risk was observed in patients treated with high dosage ARBs (adjusted HR = 0 42, 95% CI 0 24–0 75) as compared with those in the Neither group. Conclusions: ARBs may be considered as a first-line antihypertensive drug for patients with both hypertension and diabetes. As compared with those in the ACEI group, patients in the ARB group had a significant 25% lower stroke hazard, whereas this benefit was not seen in the Both group. Thus, the addition of ACE inhibitors to ARBs may offer no additional benefit or even neutralize it with respect to stroke prevention in patients with hypertension and diabetes.
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The purpose of this study was to investigate whether or not angiotensin II type 1 receptor blocker irbesartan (ARB) with a partial agonist of PPAR-γ could protect against chronic nocturnal intermittent hypoxia (CIH)–induced cardiac... more
The purpose of this study was to investigate whether or not angiotensin II type 1 receptor blocker irbesartan (ARB) with a partial agonist of PPAR-γ could protect against chronic nocturnal intermittent hypoxia (CIH)–induced cardiac Fas/FasL-mediated to mitochondria-mediated apoptosis. Sprague–Dawley rats were in a normoxic control group (CON-G), or rats were in a chronic nocturnal intermittent hypoxia group (HP-G, from 3 to 7% oxygen versus 21% oxygen per forty seconds cycle, nocturnally 8 h per day for 1 month), or rats were in a chronic nocturnal intermittent hypoxia group pretreated with ARB (50 mg/kg/day, S.C.) (ARB-HP-G). Echocardiography, H&E staining, TUNEL staining, and Western blotting were measured in the left ventricle. Hypoxia-induced SIRT1 degradation, Fas receptors, FADD, active caspase-8 and caspase-3 (Fas/FasL apoptotic pathway) and Bax, tBid, active caspase-9 and -3 (mitochondrial apoptotic pathway) and TUNEL-positive apoptosis were reduced in ARB-HP-G when compared with HP-G. IGF-I, IGF1 receptor, p-PI3k, p-Akt, Bcl2, and Bcl-XL (IGF1/PI3K/AKT pro-survival pathway) were increased in ARB-HP-G compared to HP-G. Our findings suggest that the ARB may prevent cardiac Fas/FasL to mitochondrial apoptotic pathways and enhance cardiac IGF1/PI3K/AKT pro-survival pathway in the sleep apnea model associated with JNK de-activation and SIRT1 upregulation. ARB prevents chronic sleep apnea–enhanced cardiac apoptosis via enhancing survival pathways.
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The heart is a very dynamic pumping organ working perpetually to maintain a constant blood supply to the whole body to transport oxygen and nutrients. Unfortunately, it is also subjected to various stresses based on physiological or... more
The heart is a very dynamic pumping organ working perpetually to maintain a constant blood supply to the whole body to transport oxygen and nutrients. Unfortunately, it is also subjected to various stresses based on physiological or pathological conditions, particularly more vulnerable to damages caused by oxidative stress. In this study, we investigate the molecular mechanism and contribution of IGF-IIRα in endoplasmic reticulum stress induction in the heart under doxorubicin-induced cardiotoxicity. Using in vitro H9c2 cells, in vivo transgenic rat cardiac tissues, siRNAs against CHOP, chemical ER chaperone PBA, and western blot experiments, we found that IGF-IIRα overexpression enhanced ER stress markers ATF4, ATF6, IRE1α, and PERK which were further aggravated by DOX treatment. This was accompanied by a significant perturbation in stress-associated MAPKs such as p38 and JNK. Interestingly, PARKIN, a stress responsive cellular protective mediator was significantly downregulated by IGF-IIRα concomitant with decreased expression of ER chaperone GRP78. Furthermore, ER stress-associated pro-apoptotic factor CHOP was increased considerably in a dose-dependent manner followed by elevated c-caspase-12 and c-caspase-3 activities. Conversely, treatment of H9c2 cells with chemical ER chaperone PBA or siRNA against CHOP abolished the IGF-IIRα-induced ER stress responses. Altogether, these findings suggested that IGF-IIRα contributes to ER stress induction and inhibits cellular stress coping proteins while increasing pro-apoptotic factors feeding into a cardio myocyte damage program that eventually paves the way to heart failure.
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Elevated plasma concentration of total homocysteine is a pathological condition that causes vascular endothelial injury and subsequently leads to the progression of endothelial apoptosis in atherosclerosis. Epigallocatechin gallate... more
Elevated plasma concentration of total homocysteine is a pathological condition that causes vascular endothelial injury and subsequently leads to the progression of endothelial apoptosis in atherosclerosis. Epigallocatechin gallate (EGCG), a well-known anti-oxidant in green tea, has been reported with benefits on metabolic and cardiovascular diseases. This study aimed to explore that EGCG ameliorates homocysteine-induced endothelial cell apoptosis through enhancing the sirtuin 1 (SIRT1)/AMP-activated protein kinase (AMPK) survival signaling pathway. Human umbilical endothelial cells were treated with homocysteine in the presence or absence of EGCG. We found that EGCG significantly increased the activities of SIRT1 and AMPK. EGCG diminished homocysteine-mediated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation by inhibiting protein kinase C activation as well as reactive oxygen species (ROS) generation and recovered the activity of the endogenous antioxidant enz...
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It has been well‐documented that the consumption of deep sea water (DSW) has beneficial effects on myocardial hypertrophy and cardiac apoptosis induced by hypercholesterolemia. However, the molecular mechanisms for the anti‐inflammatory... more
It has been well‐documented that the consumption of deep sea water (DSW) has beneficial effects on myocardial hypertrophy and cardiac apoptosis induced by hypercholesterolemia. However, the molecular mechanisms for the anti‐inflammatory effects of DSW on diabetic cardiomyopathy are still largely unclear. The main purpose of this present study was to test the hypothesis that DSW exerts anti‐inflammatory effects through the suppression of the TNF‐α‐mediated signaling pathways. IP injection of streptozotocin (STZ) at the dose of 65 mg/kg was used to establish a diabetes rat model. DSW mineral extracts that diluted in desalinated water were prepared in three different dosages and administered to the rats through gavages for 4 weeks. These dosages are DSW‐1X (equivalent to 37 mg Mg2+/kg/day), 2X (equivalent to 74 mg Mg2+/kg/day) and 3X (equivalent to 111 mg Mg2+ mg/kg/day). Immunofluorescence staining and Western blot showed that the protein expression level of TNF‐α was markedly higher in the STZ‐induced diabetic rat hearts than in the control group. Consequently, the phosphorylation levels of the TNF‐α‐modulated downstream signaling molecules and P38 mitogen‐activated protein kinases (MAPKs) were notably elevated in heart tissues of STZ‐induced diabetes. These higher phosphorylation levels subsequently upregulated NF‐κB‐modulated inflammatory mediators, such as cyclooxygenase (COX)‐II and inducible nitric oxide synthase (iNOS). However, treatment with DSW as well as MgSO4, the main mineral in DSW, significantly reversed all the alterations. These findings suggest that DSW has potential as a therapeutic agent for preventing diabetes‐related cardiovascular diseases.
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Cardiovascular diseases have a high prevalence worldwide and constitute the leading causes of mortality. Recently, malfunctioning of β-catenin signaling has been addressed in hypertensive heart condition. Ang-II is an important mediator... more
Cardiovascular diseases have a high prevalence worldwide and constitute the leading causes of mortality. Recently, malfunctioning of β-catenin signaling has been addressed in hypertensive heart condition. Ang-II is an important mediator of cardiovascular remodeling processes which not only regulates blood pressure but also leads to pathological cardiac changes. However, the contribution of Ang-II/β-catenin axis in hypertrophied hearts is ill-defined. Employing in vitro H9c2 cells and in vivo spontaneously hypertensive rats (SHR) cardiac tissue samples, western blot analysis, luciferase assays, nuclear-cytosolic protein extracts, and immunoprecipitation assays, we found that under hypertensive condition β-catenin gets abnormally induced that co-activated LEF1 and lead to cardiac hypertrophy changes by up-regulating the IGF-IIR signaling pathway. We identified putative LEF1 consensus binding site on IGF-IIR promoter that could be regulated by β-catenin/LEF1 which in turn modulate the ...
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Doxorubicin (DOX) is an anthracycline antibiotic commonly employed for the treatment of various cancers. However, its therapeutic uses are hampered by side effects associated with cumulative doses during the course of treatment. Whereas... more
Doxorubicin (DOX) is an anthracycline antibiotic commonly employed for the treatment of various cancers. However, its therapeutic uses are hampered by side effects associated with cumulative doses during the course of treatment. Whereas deregulation of autophagy in the myocardium has been involved in a variety of cardiovascular diseases, the role of autophagy in DOX-induced cardiomyopathy remains debated. Our earlier studies have shown that DOX treatment in a rat animal model leads to increased expression of the novel stress-inducible protein insulin-like growth factor II receptor-α (IGF-IIRα) in cardiac tissues, which exacerbated the cardiac injury by enhancing oxidative stress and p53-mediated mitochondria-dependent cardiac apoptosis. Through this study, we investigated the contribution of IGF-IIRα to dysregulation of autophagy in heart using both in vitro H9c2 cells (DOX treated, 1 µM) and in vivo transgenic rat models (DOX treated, 5 mg/kg ip for 6 wk) overexpressing IGF-IIRα sp...
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We previously reported that deep sea water (DSW) prolongs the life span of streptozotocin (STZ)-induced diabetic rats by the compensatory augmentation of the insulin like growth factor (IGF)-I survival signaling and inhibition of... more
We previously reported that deep sea water (DSW) prolongs the life span of streptozotocin (STZ)-induced diabetic rats by the compensatory augmentation of the insulin like growth factor (IGF)-I survival signaling and inhibition of apoptosis. Here, we investigated the effects of DSW on cardiac hypertrophy in diabetic rats. Cardiac hypertrophy was induced in rats by using STZ (65 mg/kg) administered via IP injection. DSW was prepared by mixing DSW mineral extracts and desalinated water. Different dosages of DSW-1X (equivalent to 37 mg Mg2+·kg−1·day−1), 2X (equivalent to 74 mg Mg2+·kg−1·day−1) and 3X (equivalent to 111 mg Mg2+·kg−1·day−1) were administered to the rats through gavage for 4 wk. Cardiac hypertrophy was evaluated by the heart weight-to-body weight ratio and the cardiac tissue cross-sectional area after hematoxylin and eosin staining. The protein levels of the cardiac hypertrophy signaling molecules were determined by Western blot. Our results showed that the suppressive eff...
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Cardiotoxicity by doxorubicin hampers its therapeutic potential as an anticancer drug, but mechanisms leading to cardiotoxicity remain contentious. Through this study, the functional contribution of insulin‐like growth factor receptor... more
Cardiotoxicity by doxorubicin hampers its therapeutic potential as an anticancer drug, but mechanisms leading to cardiotoxicity remain contentious. Through this study, the functional contribution of insulin‐like growth factor receptor type II α (IGF‐IIRα) which is a novel stress‐inducible protein was explored in doxorubicin‐induced cardiac stress. Employing both in vitro H9c2 cells and in vivo transgenic rat models (SD‐TG [IGF‐IIRα]) overexpressing IGF‐IIRα specifically in heart, we found that IGF‐IIRα leads to cardiac structural abnormalities and functional perturbations that were severely aggravated by doxorubicin‐induced cardiac stress. Overexpression of IGF‐IIRα leads to cumulative elevation of stress associated cardiac hypertrophy and apoptosis factors. There was a significant reduction of survival associated proteins p‐Akt and estrogen receptor β/α, and abnormal elevation of cardiac hypertrophy markers such as atrial natriuretic peptide, cardiac troponin‐I, and apoptosis‐inducing agents such as p53, Bax, and cytochrome C, respectively. IGF‐IIRα also altered the expressions of AT1R, ERK1/2, and p38 proteins. Besides, IGF‐IIRα also increased the reactive oxygen species production in H9c2 cells which were markedly aggravated by doxorubicin treatment. Together, we showed that IGF‐IIRα is a novel stress‐induced protein that perturbed cardiac homeostasis and cumulatively exacerbated the doxorubicin‐induced cardiac injury that perturbed heart functions and ensuing cardiomyopathy.
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The effects of Gynura bicolor aqueous extract (GAE) upon glycemic control, coagulation disorder, lipid accumulation, and glycative, oxidative, and inflammatory stresses in diabetic mice were investigated. Mice were treated with... more
The effects of Gynura bicolor aqueous extract (GAE) upon glycemic control, coagulation disorder, lipid accumulation, and glycative, oxidative, and inflammatory stresses in diabetic mice were investigated. Mice were treated with streptozotocin to induce type 1 diabetes. Diabetic mice were divided into four groups, consumed GAE at 0%, 0.25%, 0.5%, or 1%. Normal group consumed standard mouse basal diet. After 8-week treatments, mice were sacrificed after overnight fasting. Results showed that GAE supplement at 0.5% and 1% decreased plasma glucose level and increased plasma insulin level. Diabetes lowered plasma level of protein C and anti-thrombin III; and raised plasminogen activator inhibitor-1 activity and fibrinogen level in plasma. GAE supplement at 0.5% and 1% reversed these alterations. Histological data, assayed by Oil Red O stain, indicated that GAE supplement decreased lipid accumulation in liver. GAE supplement at 0.5% and 1% reduced aldose reductase activity in heart and kidney; and lowered the levels of carboxymethyllysine and pentosidine in plasma and two organs. Diabetes decreased glutathione content, and increased reactive oxygen species, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α production in heart and kidney. GAE supplement at three test doses reversed these changes. Diabetes upregulated the mRNA expression of p38 and nuclear factor kappa (NF-κ)B in heart and kidney. GAE supplement suppressed the mRNA expression of both p38 and NF-κB. These novel findings suggest that Gynura bicolor is a potent functional food for diabetic prevention or alleviation.
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IGF‐IIR activation regulates cardiac remodeling leading to apoptosis. Here, we identified the novel IGF‐IIRα (150 KDa), a truncated IGF‐IIR transcript enhances cardiac apoptosis under high‐salt uptake in transgenic rat model.... more
IGF‐IIR activation regulates cardiac remodeling leading to apoptosis. Here, we identified the novel IGF‐IIRα (150 KDa), a truncated IGF‐IIR transcript enhances cardiac apoptosis under high‐salt uptake in transgenic rat model. Echocardiographic analysis revealed decline in ejection fraction and fractional shortening percentage in IGF‐IIRα (TG) rats. We found that IGF‐IIRα TG rats developed severe apoptosis and fibrosis as identified through TUNEL assay and Masson's trichrome staining. Importantly, the heart functioning, apoptosis, and fibrosis were significantly affected under high‐salt conditions in IGF‐IIRα (TG) rats. Significant upregulation of apoptosis was evident from decreased Bcl‐2, p‐AKT, and p‐PI3K expressions with concomitant increase in Bad, cytochrome C, cleaved caspase 3 levels. We found that, IGF‐IIRα highly induced tissue fibrosis through collagen accumulation (col I, col III) and up regulated various fibrotic markers such as tPA, uPA, TGF‐β, and vimentin expressions. The observed upregulation of fibrosis were significantly regulated under high‐salt conditions and their over regulation under IGF‐IIRα over expressions shows the key role of IGF‐IIRα in promoting high‐salt induced fibrosis. During IGF‐IIRα over expression induced cardiotoxicity, under high salt condition, and it destroys the interaction between CHIP and HSF1, which promotes the degradation of HSF1 and results in upregulation of IGF‐IIR/IGF‐IIRα expressions. Altogether, the study unveils novel IGF‐IIRα in the regulation of cardiac apoptosis and fibrosis under high‐salt diet.
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Mitochondrial dysfunction is a major contributor to myocyte loss and the development of heart failure. Myocytes have quality control mechanisms to retain functional mitochondria by removing damaged mitochondria via specialized autophagy,... more
Mitochondrial dysfunction is a major contributor to myocyte loss and the development of heart failure. Myocytes have quality control mechanisms to retain functional mitochondria by removing damaged mitochondria via specialized autophagy, i.e., mitophagy. The underlying mechanisms of fission affect the survival of cardiomyocytes, and left ventricular function in the heart is poorly understood. Here, we demonstrated the direct effect and potential mechanisms of mitochondrial functional defects associated with abnormal mitochondrial dynamics in heart failure. We observed that IGF-IIR signaling produced significant changes in mitochondrial morphology and function; such changes were associated with the altered expression and distribution of dynamin-related protein (Drp1) and mitofusin (Mfn2). IGF-IIR signaled extracellular signal-regulated kinase (ERK) activation to promote Drp1 phosphorylation and translocation to mitochondria for mitochondrial fission and mitochondrial dysfunction. Mor...
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Mitochondria dysfunction is the major characteristic of mitophagy, which is essential in mitochondrial quality control. However, excessive mitophagy contributes to cell death in a number of diseases, including ischemic stroke and... more
Mitochondria dysfunction is the major characteristic of mitophagy, which is essential in mitochondrial quality control. However, excessive mitophagy contributes to cell death in a number of diseases, including ischemic stroke and hepatotoxicity. Insulin-like growth factor II (IGF-II) and its receptor (IGF-IIR) play vital roles in the development of heart failure during hypertension. We found that IGF-II triggers IGF-IIR receptor activation, causing mitochondria dysfunction, resulting in mitophagy, and cardiomyocyte cell death. These results indicated that IGF-IIR activation triggers mitochondria fragmentation, leading to autophagosome formation, and loss of mitochondria content. These results are associated with Parkin-dependent mitophagy. Additionally, autophagic proteins Atg5, and Atg7 deficiency did not suppress IGF-IIR-induced mitophagy. However, Rab9 knockdown reduced mitophagy and maintained mitochondrial function. These constitutive mitophagies through IGF-IIR activation trig...
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Deep vein thrombosis (DVT) is a potentially catastrophic condition because thrombosis, left untreated, can result in detrimental pulmonary embolism. Yet in the absence of thrombosis, anticoagulation increases the risk of bleeding. In the... more
Deep vein thrombosis (DVT) is a potentially catastrophic condition because thrombosis, left untreated, can result in detrimental pulmonary embolism. Yet in the absence of thrombosis, anticoagulation increases the risk of bleeding. In the existing literature, knowledge about the epidemiology of DVT is primarily based on investigations among Caucasian populations. There has been little information available about the epidemiology of DVT in Taiwan, and it is generally believed that DVT is less common in Asian patients than in Caucasian patients. However, DVT is a multifactorial disease that represents the interaction between genetic and environmental factors, and the majority of patients with incident DVT have either inherited thrombophilia or acquired risk factors. Furthermore, DVT is often overlooked. Although symptomatic DVT commonly presents with lower extremity pain, swelling and tenderness, diagnosing DVT is a clinical challenge for physicians. Such a diagnosis of DVT requires a ...
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Combination therapy with angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) has been stressed for its comprehensive blocking of the renin-angiotensin-aldosterone system, but the evidence for their... more
Combination therapy with angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) has been stressed for its comprehensive blocking of the renin-angiotensin-aldosterone system, but the evidence for their respective safety and efficacy, in particular with stroke prevention, is still insufficient in population-based follow-up studies in the real world. Using Taiwan's National Health Insurance claims data, we identified 5445 subjects aged 18years and older who had newly diagnosed hypertension in 1997-2010, from them diagnosed type 2 diabetes later. Among them, 2161 patients took ACEI, 1703 patients took ARB, 165 patients took both ACEI and ARB, and 1416 patients had neither. During the follow-up period, the stroke incidence density was the lowest (23.02 per 1000person-years) in ARB group, followed by the group with neither medication, the ACEI group, and ARB/ACEI combination group (24.06, 30.23, and 37.86 per 1000person-years, respectively). Compare...
Research Interests: Cardiology, Adolescent, Stroke, Humans, Hypertension, and 15 moreTaiwan, Female, Male, Young Adult, Brain Ischemia, Aged, Middle Aged, Adult, Retrospective Studies, Combination drug therapy, Type 2 Diabetes Mellitus, Angiotensin Converting Enzyme Inhibitors, Cohort Studies, Cardiovascular medicine and haematology, and Population surveillance
Doxorubicin (Dox) is an effective anticancer agent. However, its effectiveness is limited by its cardiotoxic effects. It has also been reported that the mitogen-activated protein kinase family and NF-κB can be activated by Dox treatment.... more
Doxorubicin (Dox) is an effective anticancer agent. However, its effectiveness is limited by its cardiotoxic effects. It has also been reported that the mitogen-activated protein kinase family and NF-κB can be activated by Dox treatment. DATS has been shown to be a potent antioxidant with cardioprotective effects. We investigate whether Dox induces cardiac apoptosis through JNK- and ERK-dependent NF-κB upregulation that can be reduced by DATS treatment. H9c2 cells were treated with 0.5-1.5 μM Dox for 24 hours. Dox promoted apoptosis and ROS generation and inhibited viability in a dose-dependent manner. Then, the phosphorylation levels of JNK, ERK, and NF-κB evaluated by western blot were elevated. We used inhibitors of JNK, ERK, and NF-κB to determine which of these proteins were involved in Dox-induced apoptosis. Furthermore, Dox-exposed cells were treated with DATS at doses of 1, 5, and 10 μM, and the data demonstrated that ROS generation and apoptotic proteins were decreased and ...
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Cardiac hypertrophy is a major characteristic of early-stage hypertension-related heart failure. We have found that the insulin-like growth factor receptor II (IGF-IIR) signaling was critical for hypertensive angiotensin II-induced... more
Cardiac hypertrophy is a major characteristic of early-stage hypertension-related heart failure. We have found that the insulin-like growth factor receptor II (IGF-IIR) signaling was critical for hypertensive angiotensin II-induced cardiomyocyte hypertrophy and apoptosis. Moreover, this IGF-IIR signaling was elegantly modulated by the heat shock transcription factors (HSFs) during heart failure. However, the detailed mechanism by which HSFs regulates IGF-IIR during hypertension-induced cardiac hypertrophy remains elusive. In this study, we found that heat shock transcription factor 2 (HSF2) activated IGF-IIR to induce cardiac hypertrophy for hypertension-induced heart failure. The transcriptional activity of HSF2 appeared to be primarily mediated by SUMOylation via conjugation with small ubiquitin-like modifier-1 (SUMO-1). The SUMOylation of HSF2 was severely attenuated by MEL18 (also known as polycomb group ring finger 2 or PCGF2) in the heart of spontaneously hypertensive rats (SH...
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In association with the published article "Inhibition of HSF2 SUMOylation MEL18 upregulates IGF-IIR and leads to hypertension-induced cardiac hypertrophy" (Huang et al., 2017) [1], this data article contains information about... more
In association with the published article "Inhibition of HSF2 SUMOylation MEL18 upregulates IGF-IIR and leads to hypertension-induced cardiac hypertrophy" (Huang et al., 2017) [1], this data article contains information about deSUMOylation of HSF2 on lysine 82 on angiotensin II (ANG II) -induced cardiac hypertrophy, which is mediated by MEL18. Isolated adult human whole heart tissue showed MEL18-mediated HSF2-IGF-IIR pathway is upregulated in hypertension human heart, compared to health human heart.
Doxorubicin (DOX), one useful chemotherapeutic agent, is limited in clinical use because of its serious cardiotoxicity. Growing evidence suggests that angiotensin receptor blockers (ARBs) have cardioprotective effects in DOX-induced... more
Doxorubicin (DOX), one useful chemotherapeutic agent, is limited in clinical use because of its serious cardiotoxicity. Growing evidence suggests that angiotensin receptor blockers (ARBs) have cardioprotective effects in DOX-induced cardiomyopathy. However, the detailed mechanisms underlying the action of ARBs on the prevention of DOX-induced cardiomyocyte cell death have yet to be investigated. Our results showed that angiotensin II receptor type I (AT1 R) plays a critical role in DOX-induced cardiomyocyte apoptosis. We found that MAPK signaling pathways, especially ERK1/2, participated in modulating AT1 R gene expression through DOX-induced mitochondrial ROS release. These results showed that several potential heat shock binding elements (HSE), which can be recognized by heat shock factors (HSFs), located at the AT1 R promoter region. HSF2 markedly translocated from the cytoplasm to the nucleus when cardiomyocytes were damaged by DOX. Furthermore, the DNA binding activity of HSF2 ...
Research Interests: Transcription Factors, Apoptosis, Signal Transduction, RNA interference, Cell line, and 12 moreReactive Oxygen Species, Animals, Cellular Physiology, Medical Physiology, Mitogen Activated Protein Kinase, Doxorubicin, Heat Shock Proteins, Transfection, Cardiotoxicity, Sumoylation, Heart Diseases, and binding sites
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The study was aimed to investigate the relationship between the 24-hour blood pressure and neurohormonal change in patients with secondary hypertension. Circadian blood pressure variation was studied in patients with chronic renal failure... more
The study was aimed to investigate the relationship between the 24-hour blood pressure and neurohormonal change in patients with secondary hypertension. Circadian blood pressure variation was studied in patients with chronic renal failure and primary aldosteronism. Ambulatory blood pressure was monitored every 10 minutes during daytime and every 30 minutes during nighttime. The daytime and nighttime systolic/diastolic blood pressures (SBP/DBP) in patients with primary hyperaldosteronism were significantly higher than those with primary hypertension (SBP:147 16 vs 125 11 mmHg, daytime; 142 23 vs 118 13 mmHg, nighttime; DBP: 96 18 vs 85 8 mmHg, daytime; 91 24 vs 81 9 mmHg, nighttime). In the renal form of secondary hypertension, the blood pressure did not reveal a significant difference with diurnal change in comparison with primary hypertension. The reduction in nocturnal blood pressure was less in primary hyperaldosteronism than in primary hypertension. Insufficient decrease of bloo...
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The goal of this study is to determine if Rhodiola Crenulata (RC) has protective effects on mice hearts with severe sleep apnea model. Sixty-four C57BL/6 J mice 5-6 months old were distributed into 4 groups i.e. Control group (21 % O2,... more
The goal of this study is to determine if Rhodiola Crenulata (RC) has protective effects on mice hearts with severe sleep apnea model. Sixty-four C57BL/6 J mice 5-6 months old were distributed into 4 groups i.e. Control group (21 % O2, 24 h per day, 8 weeks, n = 16); Hypoxia group (Hypoxia: 7 % O2 60 s, 20 % O2 alternating 60 s, 8 h per day, 8 weeks, n = 16); Hypoxia + 90RC and Hypoxia + 270RC group (Hypoxia for 1st 4 weeks and hypoxia pretreated 90 mg/Kg and 270 mg/Kg Rhodiola Crenulata by oral gavage per day for 2nd 4 weeks, each n = 16). Excised hearts from 4 groups of mice were analyzed for heart weight index changes using H&E staining, TUNEL-positive assays and Western Blotting protein. Cardiac widely dispersed TUNEL-positive apoptotic cells in mice hearts were less in Hypoxia + RC90 and Hypoxia + RC270 than those in Hypoxia. Compared with Hypoxia, the protein levels of Fas ligand, Fas death receptors, Fas-Associated Death Domain (FADD), activated caspase 8, and activated caspase 3 (Fas dependent apoptotic pathways) were decreased in Hypoxia + RC90, Hypoxia + RC270. The protein levels of Bad, Bax, t-Bid, activated caspase 9, activated caspase 3 (mitochondria dependent apoptotic pathway) were less in Hypoxia + RC90, Hypoxia + RC270 than those in hypoxia. The protein levels of Bcl2, Bcl-xL, p-Bad (Bcl2-realted anti-apoptotic pathway) and VEGF, p-PI3k, p-AKT (VEGF-related pro-survival pathway) were higher in Hypoxia + RC90, Hypoxia + RC270 than those in hypoxia. Our findings suggest that Rhodiola Crenulata have protective effects on chronic intermittent hypoxia-induced cardiac widely dispersed apoptosis via Fas-dependent and mitochondria-dependent apoptotic and VEGF-related pro-survival pathway.
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Cirrhotic cardiomyopathy (CCM) is a common cardiac dysfunction in patients waiting for orthotopic liver transplantation (OLT). Carbon tetrachloride (CCl₄) intraperitoneal (IP) injection has been reported as successful in a... more
Cirrhotic cardiomyopathy (CCM) is a common cardiac dysfunction in patients waiting for orthotopic liver transplantation (OLT). Carbon tetrachloride (CCl₄) intraperitoneal (IP) injection has been reported as successful in a cirrhosis-induced CCM model. In this work, we used the same assay for CCM induction using CCl₄ (0.2 mg/kg) IP injection twice per day for 14 days during the cardiac protection drugs treatment process. The cardiac protection drugs were silymarin (100 mg/kg/day), baicalein (30 mg/kg/day), San Huang Shel Shin Tang (SHSST, 30 mg/kg/day) and β-cyclodextrin modified SHSST (SHSSTc, 30 mg/kg/day and 300 mg/kg/day). After 4 weeks of treatment, the SHSSTc cardiac protection effects were determined through activation of the IGF1R cell survival pathway and inhibition of Fas-FADD death domain induced-apoptosis. SHSSTc cardiac protection was enhanced through β-cyclodextrin modification, which increased bio-availability, and displayed stronger protective effects than silymarin a...
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Consumption of deep sea minerals (DSM), such as magnesium, calcium, and potassium, is known to reduce hypercholesterolemia-induced myocardial hypertrophy and cardiac-apoptosis and provide protection against cardiovascular diseases. Heart... more
Consumption of deep sea minerals (DSM), such as magnesium, calcium, and potassium, is known to reduce hypercholesterolemia-induced myocardial hypertrophy and cardiac-apoptosis and provide protection against cardiovascular diseases. Heart diseases develop as a lethal complication among diabetic patients usually due to hyperglycemia-induced cardiac-apoptosis that causes severe cardiac-damages, heart failure, and reduced life expectancy. In this study, we investigated the potential of DSM and its related cardio-protection to increase the life expectancy in diabetic rats. In this study, a heart failure rat model was developed by using streptozotocin (65 mg kg(-1) ) IP injection. Different doses of DSM-1× (37 mg kg(-1) day(-1) ), 2× (74 mg kg(-1) day(-1) ) and 3× (111 mg kg(-1) day(-1) ), were administered to the rats through gavages for 4 weeks. The positive effects of DSM on the survival rate of diabetes rats were determined with respect to the corresponding effects of MgSO4 . Further, to understand the mechanism by which DSM enhances the survival of diabetic rats, their potential to regulate cardiac-apoptosis and control cardiac-dysfunction were examined. Echocardiogram, tissue staining, TUNEL assay, and Western blotting assay were used to investigate modulations in the myocardial contractile function and related signaling protein expression. The results showed that DSM regulate apoptosis and complement the cardiomyocyte proliferation by enhancing survival mechanisms. Moreover DSM significantly reduced the mortality rate and enhanced the survival rate of diabetic rats. Experimental results show that DSM administration can be an effective strategy to improve the life expectancy of diabetic subjects by improving cardiac-cell proliferation and by controlling cardiac-apoptosis and associated cardiac-dysfunction. © 2014 Wiley Periodicals, Inc. Environ Toxicol, 2014.
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Cardiovascular disease is the second leading cause of death (9.1 %) in Taiwan. Heart function deteriorates with age at a rate of 1 % per year. As society ages, we must study the serious problem of cardiovascular disease. SIRT1 regulates... more
Cardiovascular disease is the second leading cause of death (9.1 %) in Taiwan. Heart function deteriorates with age at a rate of 1 % per year. As society ages, we must study the serious problem of cardiovascular disease. SIRT1 regulates important cellular processes, including anti-apoptosis, neuronal protection, cellular senescence, aging, and longevity. In our previous studies, rats with obesity, high blood pressure, and diabetes exhibiting slowed myocardial performance and induced cell apoptosis were reversed via sports training through IGF1 survival signaling compensation. This study designed a set of experiments with rats, in aging and exercise groups, to identify changes in myocardial cell signaling transduction pathways. Three groups of three different aged rats, 3, 12, and 18 months old, were randomly divided into aging groups (C3, A12, and A18) and exercise groups (E3, AE12, and AE18). The exercise training consisted of swimming five times a week with gradual increases from the first week from 20 to 60 min for 12 weeks. After the sports training process was completed, tissue sections were taken to observe cell organization (hematoxylin and eosin (H&E) stain) and apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays) and to observe any changes in the myocardial tissues and proteins (Western blotting). The experimental results show that cardiomyocyte apoptotic pathway protein expression increased with age in the aging groups (C3, A12, and A18), with improvement in the exercise group (E3, AE12, and AE18). However, the expression of the pro-survival p-Akt protein decreased significantly with age and reduced performance. The IGF1R/PI3K/Akt survival pathway in the heart of young rats can indeed be increased through exercise training. As rats age, this pathway loses its original function, even with increasing upstream IGF1. However, levels of SIRT1 and its downstream target PGC-1α were found to increase with age and compensatory performance. Moreover, exercise training enhanced the SIRT longevity pathway compensation instead of IGF1 survival signaling to improve cardiomyocyte survival.
Research Interests: Aging, Apoptosis, Biopsy, Western blotting, Signal Transduction, and 7 moreBiological Sciences, Longevity, Age, Animals, Rats, Myocardium, and Sirtuin
Exercise training is considered a benefit to heart function, but the benefit in aging hearts remains unknown. Activation of the PI3K-Akt survival pathway and suppression of Fas/FADD/caspase-8 apoptotic signaling by exercise training in... more
Exercise training is considered a benefit to heart function, but the benefit in aging hearts remains unknown. Activation of the PI3K-Akt survival pathway and suppression of Fas/FADD/caspase-8 apoptotic signaling by exercise training in hearts from young subjects have been described in our previous studies. However, the mechanisms are still unclear and need to be explored in aging hearts. Thus, 18-month-old rats were used as a model and underwent swimming exercise training, resveratrol treatment (15 mg/kg/day), or exercise training with resveratrol treatment for 1 month. The results showed that heart function in each group improved. However, the 18-month-old rats in the exercise-only group experienced the slightly inevitable impact of increased TNF-α, cell apoptosis, and fibrosis. In the protein analysis, the PI3K-Akt pathway was slightly increased with exercise training and resveratrol treatment, but Sirtuin 1 (SIRT1) was only highly activated with resveratrol treatment in the aged rat hearts. Moreover, the exercise training plus resveratrol group benefited from SIRT1 and PI3K-Akt dual pathways and blocked FOXO3 accumulation. Our experimental results strongly suggest that resveratrol treatment improves the beneficial effects of exercise training in aging rat hearts.