Haipeng Guo

Taxifolin protects against cardiac hypertrophy and fibrosis during biomechanical stress of pressure overload

Cardiac hypertrophy is a key pathophysiological component to biomechanical stress, which has been considered to be an independent and predictive risk factor for adverse cardiovascular events. Taxifolin (TAX) is a typical plant flavonoid, which has long been used clinically for treatment of cardiovascular and cerebrovascular diseases. However, very little is known about whether TAX can influence the development of cardiac hypertrophy. In vitro studies, we found that TAX concentration-dependently inhibited angiotensin II (Ang II) induced hypertrophy and protein synthesis in cardiac myocytes. Then we established a mouse model by transverse aortic constriction (TAC) to further confirm our findings. It was demonstrated that TAX prevented pressure overload induced cardiac hypertrophy in mice, as assessed by ventricular mass/body weight, echocardiographic parameters, myocyte cross-sectional area, and the expression of ANP, BNP and β-MHC. The excess production of reactive oxygen species (ROS) played critical role in the development of cardiac hypertrophy. TAX arrested oxidative stress and decreased the expression of 4-HNE induced by pressure overload. Moreover, TAX negatively modulated TAC-induced phosphorylation of ERK1/2 and JNK1/2. Further studies showed that TAX significantly attenuated left ventricular fibrosis and collagen synthesis through abrogating the phosphorylation of Smad2 and Smad2/3 nuclear translocation. These results demonstrated that TAX could inhibit cardiac hypertrophy and attenuate ventricular fibrosis after pressure overload. These beneficial effects were at least through the inhibition of the excess production of ROS, ERK1/2, JNK1/2 and Smad signaling pathways. Therefore, TAX might be a potential candidate for the treatment of cardiac hypertrophy and fibrosis.

The epidemiology, antifungal use and risk factors of death in elderly patients with candidemia: a multicentre retrospective study

BackgroundThe elderly patients affected by candidemia are growing in proportion to inpatients, but available data are limited. We aimed to determine the epidemiology, antifungal management and clinical risk factors of death in the elderly population with candidemia in China.MethodsThis retrospective study included 63 elderly (≥65 years) and 84 younger patients (16–60 years) at 4 tertiary hospitals. Multivariable logistic regression model was used to identify independent risk factors of death in elderly patients.ResultsThe distribution of Candida species did not differ between elderly and younger patients (p >0.05). Resistance to fluconazole and voriconazole for non-Candida albicans species in elderly patients was approximately double that in younger patients. Host-related risk factors (e.g., underlying solid tumour, diabetes mellitus and chronic renal failure) and hospital-related factors (e.g., prior stay in an intensive care unit, mechanical ventilation, central vascular and urethral catheters placement) were identified more common in elderly patients. Elderly patients less often received triazoles and were less likely to receive antifungal therapies mostly because elderly or their guardians quit antifungal therapies. APACHE II scores and 30-day mortality were higher for elderly than younger patients (31.7% vs. 16.7%, p =0.032). For elderly patients, antifungal therapy administered before microbiological documentation was the only protective factor for death, whereas absence of antifungal therapies, receipt of mechanical ventilation and APACHE II score ≥20 were independent predictors of death.ConclusionsElderly patients with candidemia had poor prognoses characterized by certain host and hospital-related risk factors and special pathogen resistance features. More awareness of the burden of this disease is required, and the absence of antifungal therapies should be avoided to improve the prognoses of elderly patients with this severe infection.

Isorhynchophylline protects against pulmonary arterial hypertension and suppresses PASMCs proliferation

Increased pulmonary arterial smooth muscle cells (PASMCs) proliferation is a key pathophysiological component of pulmonary vascular remodeling in pulmonary arterial hypertension (PAH). Isorhynchophylline (IRN) is a tetracyclic oxindole alkaloid isolated from the Chinese herbal medicine Uncaria rhynchophylla. It has long been used clinically for treatment of cardiovascular and cerebrovascular diseases. However, very little is known about whether IRN can influence the development of PAH. Here we examined the effect of IRN on monocrotaline (MCT) induced PAH in rats. Our data demonstrated that IRN prevented MCT induced PAH in rats, as assessed by right ventricular (RV) pressure, the weight ratio of RV to (left ventricular+septum) and RV hypertrophy. IRN significantly attenuated the percentage of fully muscularized small arterioles, the medial wall thickness, and the expression of smooth muscle α-actin (α-SMA) and proliferating cell nuclear antigen (PCNA). In vitro studies, IRN concentration-dependently inhibited the platelet-derived growth factor (PDGF)-BB-induced proliferation of PASMCs. Fluorescence-activated cell-sorting analysis showed that IRN caused G0/G1 phase cell cycle arrest. IRN-induced growth inhibition was associated with downregulation of Cyclin D1 and CDK6 as well as an increase in p27Kip1 levels in PDGF-BB-stimulated PASMCs. Moreover, IRN negatively modulated PDGF-BB-induced phosphorylation of PDGF-Rβ, ERK1/2, Akt/GSK3β, and signal transducers and activators of transcription 3 (STAT3). These results demonstrate that IRN could inhibit PASMCs proliferation and attenuate pulmonary vascular remodeling after MCT induction. These beneficial effects were at least through the inhibition of PDGF-Rβ phosphorylation and its downstream signaling pathways. Therefore, IRN might be a potential candidate for the treatment of PAH.

The Differences in the Epidemiology and Predictors of Death between Candidemia Acquired in Intensive Care Units and Other Hospital Settings

OBJECTIVE The burden of candidemia is shifting from intensive care units (ICU) to non-ICU settings. This study aimed to define the differences in epidemiology and predictors of death between ICU-acquired candidemia (ICUAC) and non-ICUAC. METHODS We conducted a retrospective study of 80 patients with ICUAC and 147 patients with non-IUCAC at five hospitals. RESULTS The distribution of Candida species and resistance to antifungal agents did not differ between the ICUAC and non-ICUAC groups. ICUAC patients received more echinocandins and less triazoles, as well as more adequate antifungal therapy than non-ICUAC patients (all p<0.05). ICUAC patients had a significantly higher average acute physiology and chronic health evaluation (APACHE) II score (21.0±7.9 vs. 17.8±8.6; p<0.01), Sequential Organ Failure Assessment score (9.2±5.5 vs. 7.4±3.9; p<0.05) and day-90 mortality rate (52.5% vs. 36.7%; p<0.05) when compared to non-ICUAC patients. Using a multivariate logistic analysis, adequate antifungal therapy was found to be the only protective factor for death in both groups. Respiratory failure supported with invasive mechanical ventilation, renal failure supported with replacement therapy and an APACHE II score ≥20 were independent predictors of death in ICUAC patients, while age ≥60 years, concurrent bacteremia and APACHE II score ≥20 were independent predictors of death in non-ICUAC patients. CONCLUSION The Candida species and antifungal resistance profiles in patients with ICUAC were similar to non-ICUAC patients, but led to worse outcomes. The protective and risk factors for death may therefore be relevant for the clinical management of patients with candidemia in ICU and non-ICU settings.

Notch1 inhibition reduces low shear stress-induced plaque formation

Low shear stress (LSS) contributes to the pathogenesis of inflammatory diseases, such as atherosclerosis. Notch1 is a type I transmembrane receptor that critically determines the growth, differentiation, and survival of various cell types, but its role and mechanism in LSS-induced inflammatory response remains undetermined. Apolipoprotein E-deficient (ApoE(-/-)) mice were fed with high fat diet and administered intraperitoneally with DAPT (a γ-secretase inhibitor). Perivascular shear stress modifiers were placed around the right carotid arteries to induce LSS. The left carotid arteries with undisturbed shear stress (USS) were used as the control. LSS increased Delta-like 1 (DLL-1) protein expression and the expression of Notch1 and NICD, while DAPT administration reduced NICD expression. Compared with the LSS group, DAPT reduced LSS-induced plaque formation and intercellular adhesion molecule 1 (ICAM-1) expression. Human umbilical vein endothelial cells (HUVECs) were exposure to undisturbed shear stress (USS, 1Pa) or LSS (0.4Pa). Notch1 was inhibited by siRNA or DAPT. RT-PCR and western blotting analysis showed that LSS upregulated the expression of Notch1 in a time-dependent manner. Caveolin-1 (CAV1) inhibition by siRNA could reduce Notch1 and NICD expression. Compared with USS, LSS increased inflammatory response, including IL-1β and IL-6 secretion, ICAM-1 and inducible nitric oxide synthase (iNOS) expression, and THP-1 cells adhesion. Notch1 inhibition by siRNA or DAPT could reduce these inflammatory responses by reduction of NF-κB phosphorylation, upregulation of IkBα expression, and inhibition of nuclear translocation of NF-κB, while Notch1 activation by DLL-4 had an adverse effect. The Notch signaling system is therefore a potential target for modulating LSS-induced inflammation response during atherosclerosis.

Isoquercitrin protects against pulmonary hypertension via inhibiting PASMCs proliferation

Pulmonary vascular remodelling is a common feature among the heterogeneous disorders that cause pulmonary arterial hypertension (PAH), and pulmonary arterial smooth muscle cells (PASMCs) proliferation impact the long‐term prognosis of the patient. Isoquercitrin (IQC) is a flavonoid with anti‐oxidative, anti‐inflammatory and anti‐proliferative activations. This study aimed to investigate whether IQC could prevent PASMCs proliferation and vascular remodelling in monocrotaline (MCT) induced PAH. Male Wistar rats were administered with Vehicle or 0.1% IQC maintain feed after MCT (40 mg/kg) injection. Haemodynamic changes, right ventricular hypertrophy and lung morphological features were assessed 3 weeks later. MCT‐induced PAH, pulmonary vascular remodelling and PASMCs proliferation in Vehicle‐treated rats. IQC reduced the right ventricle systolic pressure (RVSP), the ratio of RV/LV+S and the RV hypertrophy. IQC significantly alleviated the expression of proliferating cell nuclear antigen (PCNA), smooth muscle α‐actin (α‐SMA), and the percentage of fully muscularized small arterioles. In vitro studies, PASMCs were pretreated with IQC and stimulated with platelet‐derived growth factor (PDGF)‐BB (20 ng/mL). IQC suppressed PDGF‐BB‐induced PASMCs proliferation and caused G0/G1 phase cell cycle arrest. IQC downregulated the expression of Cyclin D1 and CDK4 as well as inhibited p27Kip1 degradation. Meanwhile, IQC negatively modulated PDGF‐BB‐induced phosphorylation of PDGF‐Rβ, Akt/GSK3β and ERK1/2. IQC ameliorated MCT‐induced pulmonary vascular remodelling via suppressing PASMCs proliferation and blocking PDGF‐Rβ signalling pathway.

Ischemia-modified albumin is a predictor of short-term mortality in patients with severe sepsis

Purpose: One of the most important events leading to morbidity and mortality in patients with severe sepsis is the development of global tissue hypoperfusion and oxidative damage. Ischemia‐modified albumin (IMA), an albumin generated under ischemic and oxidative conditions, is a marker of oxidative stress and hypoperfusion. Here, we investigated whether IMA level could predict short‐term mortality with severe sepsis. Methods: A prospective cohort study was conducted from April 2014 to October 2014 in intensive care units in a tertiary hospital. At the onset of severe sepsis, serum IMA level was measured, and baseline and laboratory data, infection sources, and underlying diseases were recorded; Sequential Organ Failure Assessment and Acute Physiology and Chronic Health Evaluation II scores were calculated. Multivariate logistic regression and receiver operating characteristic curve analyses were used to evaluate predictors of mortality. Kaplan‐Meier analysis was used to compare survival at day 28. Results: A total of 117 patients with severe sepsis were included (overall 28‐day mortality, 24.8%). The IMA level was higher in nonsurvivors than in survivors (P < .05). It was a strong predictor of 28‐day mortality (area under the receiver operating characteristic curve, 0.742; P < .001), and the optimal cutoff for IMA level maximizing sensitivity and specificity was 110 U/mL. On multivariate logistic regression, Acute Physiology and Chronic Health Evaluation II score and IMA level were independent risk factors for death. Survival rate was reduced with very high IMA level (≥110 U/mL; P < .05). Conclusions: The IMA level, especially at least 110 U/mL, may be a useful predictor of death for patients with severe sepsis.

Comparison of quantitative computed tomography analysis and single-indicator thermodilution to measure pulmonary edema in patients with acute respiratory distress syndrome

ObjectiveTo compare quantitative computed tomography (CT) analysis and single-indicator thermodilution to measure pulmonary edema in patients with acute respiratory distress syndrome (ARDS).MethodTen patients with ARDS were included. All underwent spiral CT of the thorax for estimating gas content of lung (GVCT), tissue volume of lung (TVCT), tissue volume index (TVI), mean radiographic attenuation (CTmean) for the whole lung and gas-to-tissue ratio (g/t). Pulmonary thermal volume (PTV) and extravascular lung water index (ELWI) were determined by the PiCCO plus system. CT or single-indicator thermodilution variables were correlated with respiratory system compliance (Crs), PaO2/FiO2, and Acute Physiology And Chronic Health EvaluationII (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores.Results1) TVCT and PTV were positively correlated (r =0.8878; P = 0.0006; equation of regression line: PTV = 1.0793 × TVCT + 179.8) as were TVI and ELWI (r =0.9459; P < 0.0001; equation of regression line: ELWI = 1.4506 × TVI-8.7792). The bias between TVCT and PTV as well as TVI and ELWI was -277 ± 217 and 0.62 ± 4.56, respectively. 2) ELWI and CT distribution of lung-tissue compartments were not correlated. 3) CT or single-indicator thermodilution variables were not correlated with Crs, PaO2/FiO2 or APACHE II or SOFA score.ConclusionQuantitative CT analysis and single-indicator thermodilution showed good agreement in measuring pulmonary edema.