ABSTRACT
Ionizing radiation induces brain inflammation and the impairment of neurogenesis by activating microglia and inducing apoptosis in neurogenic zones. However, the causal relationship between microglial activation and the impairment of neurogenesis as well as the relevant molecular mechanisms involved in microRNA (miR) remain unknown. In the present study, we employed immunohistochemistry and real-time RT-PCR to study the microglial activation and miRNA expression in mouse brains. Real-time RT-PCR, western blot, ELISA, cell proliferation and cytotoxicity assay were used in BV2 and mouse neural stem cells (NSCs). In the mouse model, we found the acute activation of microglia at 1 day and an increased number of microglial cells at 1, 7 and 120 days after irradiation at postnatal day 3 (P3), day 10 (P10) and day 21 (P21), respectively. In cell models, the activation of BV2, a type of microglial cell line, was observed after gamma irradiation. Real-time RT-PCR analysis revealed a deceased expression of miR-181b-2-3p and an increased expression of its target SRY-related high-mobility group box transcription factor 21 (SOX21) in a dose- and time-dependent fashion. The results of the luciferase reporter assay confirmed that SOX21 was the target of miR-181b-2-3p. Furthermore, SOX21 knockdown by siRNA inhibited the activation of microglia, thereby suggesting that the direct interaction of 181b-2-3p with SOX21 might be involved in radiation-induced microglial activation and proliferation. Interestingly, the gamma irradiation of NSCs increased miR-181b-2-3p expression but decreased SOX21 mRNA, which was the opposite of irradiation-induced expression in BV2 cells. As irradiation reduced the viability and proliferation of NSCs, whereas the overexpression of SOX21 restored the impaired cell viability and promoted the proliferation of NSCs, the findings suggest that the radiation-induced interaction of miR-181b-2-3p with SOX21 may play dual roles in microglia and NSCs, respectively, leading to the impairment of brain neurogenesis.
Subject(s)
MicroRNAs , Neural Stem Cells , Mice , Animals , Microglia/metabolism , MicroRNAs/genetics , Cell Line , RNA, Small Interfering/metabolism , Neural Stem Cells/metabolismABSTRACT
Acute kidney injury (AKI) is known as a sudden episode of kidney injury, which happens suddenly within a few hours or a few days. Quercetin (3,3',4',5,7-pentahydroxyflavone) is a flavonoid found in plants. Quercetin is known to have several biological activities, such as anti-oxidant, anti-inflammatory, and anti-carcinogenic effects. However, low water solubility and bioavailability are the limitations of quercetin for its clinical applications. Moreover, ischemia/reperfusion (I/R) injury is a common cause of AKI. There are no satisfactory strategies for I/R-induced AKI. Developing suitable preventive or therapeutic intervention for AKI is an important and urgent issue. We investigated the benefit effect of synthesized polyethylene glycol (PEG) conjugated polyethyleneimine (PEI) nanoparticles for targeted delivery of quercetin on AKI in a mouse model. An I/R-induced AKI mouse model was used to evaluate the therapeutic effect of quercetin polymeric nanoparticles by intravenous injection. Biochemical changes for renal function in blood samples were analyzed. Histological and immunohistochemical changes were also analyzed. The biochemical changes of blood urea nitrogen (BUN), creatinine, and cystatin C were significantly increased in I/R-induced AKI mice, which could be significantly reversed by quercetin polymeric nanoparticles. Quercetin polymeric nanoparticles could also significantly decrease the histological lesions, positive staining for 3-nitrotyrosine and cyclooxygenase-2, and lipid peroxidation in the kidneys of I/R-induced AKI mice. These results demonstrate for the first time that quercetin polymeric nanoparticles possess therapeutic potential for the treatment of I/R-induced AKI in vivo.
Subject(s)
Acute Kidney Injury , Nanoparticles , Reperfusion Injury , Acute Kidney Injury/drug therapy , Acute Kidney Injury/etiology , Animals , Disease Models, Animal , Female , Humans , Ischemia/pathology , Kidney/pathology , Male , Mice , Quercetin/pharmacology , Reperfusion , Reperfusion Injury/complications , Reperfusion Injury/drug therapy , Reperfusion Injury/pathologyABSTRACT
Tumor necrosis factor (TNF)-α activates a diverse array of signaling pathways in vascular endothelial cells (ECs), leading to the inflammatory phenotype that contributes to the vascular dysfunction and neutrophil emigration in patients with sepsis. To date, it is not well understood what key regulator might coordinate signaling pathways to achieve inflammatory response in TNF-α-stimulated ECs. This study investigated the role of dual specificity phosphatase-6 (DUSP6) in the regulation of endothelial inflammation. Using knockout mice, we found that DUSP6 is important for TNF-α-induced endothelial intercellular adhesion molecule-1 (ICAM-1) expression in aorta and in vein. Moreover, genetic deletion of Dusp6 in pulmonary circulation significantly alleviated the susceptibility of mice to lung injury caused by neutrophil recruitment during experimental sepsis induced by TNF-α or lipopolysaccharide (LPS). The role of DUSP6 was further investigated in primary human umbilical vein endothelial cells (HUVECs). Employing RNAi approach in which endogenous DUSP6 was ablated, we showed a critical function of DUSP6 to facilitate TNF-α-induced ICAM-1 expression and endothelial leukocyte interaction. Interestingly, DUSP6-promoted endothelial inflammation is independent of extracellular signaling-regulated kinase (ERK) signaling. On the other hand, inducible DUSP6 leads to activation of canonical nuclear factor (NF)-κB-mediated transcription of ICAM-1 gene in TNF-α-stimulated human ECs. These results are the first to demonstrate a positive role of DUSP6 in endothelial inflammation-mediated pathological process and the underlying mechanism through which DUSP6 promotes NF-κB signaling in the inflamed ECs. Our findings suggest that manipulation of DUSP6 holds great potential for the treatment of acute inflammatory diseases.
Subject(s)
Dual Specificity Phosphatase 6/physiology , Endothelium, Vascular/enzymology , Gene Expression Regulation/physiology , Intercellular Adhesion Molecule-1/biosynthesis , Acute Lung Injury/physiopathology , Acute Lung Injury/prevention & control , Adoptive Transfer , Animals , Aorta , Cell Adhesion , Chemotaxis, Leukocyte , Dual Specificity Phosphatase 6/deficiency , Dual Specificity Phosphatase 6/genetics , Endothelium, Vascular/pathology , Extracellular Signal-Regulated MAP Kinases/physiology , Genes, Reporter , Human Umbilical Vein Endothelial Cells , Humans , Inflammation , Intercellular Adhesion Molecule-1/genetics , Lipopolysaccharides/pharmacology , Mice , NF-kappa B/metabolism , Neutrophil Infiltration , Tumor Necrosis Factor-alpha/pharmacology , U937 Cells , Vena Cava, Inferior , Whole-Body IrradiationABSTRACT
Berberine, an isoquinoline alkaloid isolated from several traditional Chinese herbal medicines, has been shown to suppress growth and induce apoptosis in some tumor cell lines. However, berberine has also been reported to attenuate H2 O2 -induced oxidative injury and apoptosis. The basis for these ambiguous effects of berberine-triggering or preventing apoptosis-has not been well characterized to date. In the current investigation, we examined whether berberine exerts cytotoxic effects on mouse embryos at the blastocyst stage and affects subsequent embryonic development in vitro and in vivo. Treatment of blastocysts with berberine (2.5-10 µM) induced a significant increase in apoptosis and a corresponding decrease in trophectoderm cell number. Moreover, the implantation success rate of blastocysts pretreated with berberine was lower than that of their control counterparts. Pretreatment with berberine was also associated with increased resorption of postimplantation embryos and decreased fetal weight. In an animal model, intravenous injection of berberine (2, 4, or 6 mg/kg body weight/d) for 4 days resulted in apoptosis of blastocyst cells and early embryonic developmental injury. Berberine-induced injury of mouse blastocysts appeared to be attributable to oxidative stress-triggered intrinsic apoptotic signaling processes that impaired preimplantation and postimplantation embryonic development. Taken together, our results clearly demonstrate that berberine induces apoptosis and retards early preimplantation and postimplantation development of mouse embryos, both in vitro and in vivo.
Subject(s)
Apoptosis/drug effects , Berberine/toxicity , Embryonic Development/drug effects , Oxidative Stress , Animals , Blastocyst/cytology , Blastocyst/drug effects , Cell Count , Embryo Implantation/drug effects , Female , Mice , Mice, Inbred ICR , Pregnancy , Signal TransductionABSTRACT
Recent studies have reported that osteoarthritis (OA) is related to inflammation and atherosclerosis. Studies on the relationship between OA and acute coronary syndrome (ACS) are scant. We evaluated the risk of ACS in OA patients of an Asian population. This longitudinal, population-based cohort study investigated the incidence and risk of ACS in 46,042 patients with newly diagnosed OA and 46,042 controls selected randomly from the general population and frequency matched according to age, sex, and entry year (2002-2003). The follow-up period ranged from the entry date until the date of an ACS event, loss to follow-up, or the end of 2010. We employed Cox proportional hazard models to estimate the effects of OA on the risk of ACS. The OA patients showed a 15 % higher risk of ACS than did the controls after adjustment for covariates (adjusted hazard ratio [aHR] = 1.15, 95 % confidence interval [CI] = 1.08-1.23). The risk of ACS in the OA patients was the greatest in young adults (aHR = 2.0, 95 % CI = 1.44-2.78), followed by middle-aged (aHR = 1.15, 95 % CI = 1.01-1.31) and older adults (aHR = 1.11, 95 % CI = 1.03-1.20). The risk of ACS was 1.96-fold in young adults with mild to moderate OA and 3.51-fold in young adults with severe OA compared with their counterparts without OA. OA carries an increased risk of ACS, particularly in young adults with severe OA. Clinicians should employ proactive strategies for preventing ACS occurrence in these patients.
Subject(s)
Acute Coronary Syndrome/epidemiology , Osteoarthritis/epidemiology , Adult , Age Factors , Aged , Comorbidity , Female , Humans , Incidence , Male , Middle Aged , Retrospective Studies , Risk , Sex Factors , Taiwan/epidemiology , Young AdultABSTRACT
Diabetes mellitus may cause vascular endothelial damage via endothelial matrix metalloproteinase-2 (MMP-2). The role of endothelial autophagy in MMP-2-mediated cell injury in response to high-glucose (HG) stimulation was rarely described. In this study, we used HG-treated human umbilical vein endothelial cells (HUVECs) to investigate the effect of autophagy on MMP-2-induced cell transmigration and apoptosis. THP-1 transmigration was detected by the transmigration assay. Light chain 3 (LC3, representing autophagy), MMP-2, and poly (ADP-ribose) polymerase (PARP, representing apoptosis) of HG (33 mM)-treated HUVECs were evaluated by western blot analysis. The MMP-2 activity was also examined by gelatin zymography. We used GM6001 (10 µM, an MMP-2 inhibitor) to investigate the relationship of MMP-2 and THP-1 transmigration. Using 3-methyladenine (3MA, 5 mM, an LC3 inhibitor), we explored the effects of autophagy on MMP-2 expression, THP-1 transmigration, and apoptosis. Our results showed that HG increased LC3-II expression, MMP-2 activity, THP-1 transmigration, and cleaved PARP expression in a time-dependent manner (0-48 h); among them, LC3-II appeared earlier (0-24 h) than the others (24-48 h). GM6001 suppressed MMP-2 activity and ameliorated THP-1 transmigration. 3MA suppressed LC3-II expression and increased MMP-2 expression, THP-1 transmigration, and cleaved PARP expression. From these sequential findings, we demonstrated that autophagy plays a protective role in MMP-2-mediated cell transmigration and cell death in HG-stimulated HUVECs.
Subject(s)
Apoptosis/physiology , Autophagy/physiology , Cell Movement/physiology , Glucose/pharmacology , Human Umbilical Vein Endothelial Cells/metabolism , Matrix Metalloproteinase 2/metabolism , Adenine/analogs & derivatives , Adenine/metabolism , Cell Line , Diabetes Mellitus/pathology , Dipeptides/pharmacology , Endothelium, Vascular/cytology , Endothelium, Vascular/pathology , Glucose/metabolism , Humans , Matrix Metalloproteinase Inhibitors/pharmacology , Poly(ADP-ribose) Polymerases/metabolismABSTRACT
Alzheimer dementia (AD) is the commonest form of dementia. Although illiteracy is associated with high prevalence of dementia of the Alzheimer type (DAT), their relationship is still unclear. Nevertheless, mild DAT in illiterate participants seems to be due to brain atrophy.In this study, we compared the impact of brain metabolism efficiency in healthy participants and less-educated patients with mild DAT using 2-fluoro-2-deoxy-D-glucose (F-FDG-PET) positron emission tomography. Out of 43 eligible less-educated participants with dementia, only 23 (14 women and 9 men) met Diagnostic and Statistical Manual (DSM)-III-R or DSM-IV criteria for DAT and AD and were included. Participants with intracranial insults were excluded by brain magnetic resonance imaging and participants with metabolic or systemic conditions were excluded by blood sampling. In addition, 16 cognitively normal elderly (age >70 years), including 7 women and 9 men, were enrolled in the sham group. The PET imaging data were analyzed using statistical parametric mapping (SPM8) to determine reliability and specificity.Glucose metabolic rate was low in the DAT group, especially in the middle temporal gyrus, middle frontal gyrus, superior frontal gyrus, inferior frontal gyrus, posterior cingulate gyrus, angular gyrus, parahippocampal gyrus, middle occipital gyrus, rectal gyrus, and lingual gyrus.Our results showed that DAT patients with less education not only have prominent clinical signs and symptoms related to dementia but also decreased gray matter metabolism.
Subject(s)
Alzheimer Disease/diagnostic imaging , Brain Diseases, Metabolic/diagnostic imaging , Brain/metabolism , Fluorodeoxyglucose F18 , Glucose/metabolism , Positron-Emission Tomography/methods , Aged , Aged, 80 and over , Alzheimer Disease/etiology , Alzheimer Disease/metabolism , Brain/diagnostic imaging , Brain Diseases, Metabolic/complications , Brain Diseases, Metabolic/metabolism , Female , Humans , Male , Prognosis , Radiopharmaceuticals , Reproducibility of Results , Severity of Illness IndexABSTRACT
Nicotine is the major component in cigarette smoke and has been recognized as a risk factor for various cardiovascular diseases such as atherosclerosis. However, the definite pathogenesis of nicotine-mediated endothelial dysfunction remains unclear because hemodynamic factor in most of prior in vitro studies was excluded. To understand how nicotine affects endothelium in the dynamic environment, human umbilical vein endothelial cells were treated by different laminar shear stresses (LSS; 0, 6, 8, and 12 dynes cm(-2)) with and without 10(-4) M nicotine for 12 h in a parallel plate flow system, following detections of cellular morphology and apoptotic level. Our results showed that cells sheared by 12 dynes cm(-2) LSS with nicotine excessively elongated and aligned with the flow direction, and exhibited significant apoptosis as compared to the groups with nicotine or LSS alone. We reasoned that the irregular morphological rearrangement and elevated apoptosis were resulted from the interruption of mechanostasis due to cytoskeletal collapse. Furthermore, all the impaired responses can be rescued by treatment with free radical scavenger ascorbic acid (10(-4) M), indicating oxidative stress was likely mediated with the impairments. In summary, our findings demonstrated an essential role of LSS in nicotine-mediated endothelial injury occurring in the physiological environment.
Subject(s)
Apoptosis/drug effects , Cytoskeleton/metabolism , Hemodynamics , Human Umbilical Vein Endothelial Cells/metabolism , Nicotine/pharmacology , Shear Strength/drug effects , Humans , Nicotine/adverse effectsABSTRACT
OBJECTIVE: The present study investigates the relationship between BMI and all-cause mortality among middle-aged and older adults with or without pre-existing diseases. DESIGN: A population-based cohort study. SETTING: The Taiwan Longitudinal Study on Aging is a nationwide prospective cohort study comprising a representative random sample of middle-aged and older adults. The study period was 1996-2007. SUBJECTS: We followed 4145 middle-aged and older adults, totalling 42,353 person-years. RESULTS: Overweight and mildly obese participants showed a 16% and 30% decrease in the risk of death, respectively, compared with those of normal weight after adjusting for potential covariates (e.g. demographic characteristics, health behaviour, co-morbidities and physical function). Underweight adults showed a 1.36-fold increased adjusted hazard ratio of death compared with normal-weight adults. Adults with a BMI of 27.0-28.0 kg/m(2) showed a significantly lower adjusted hazard ratio of all-cause mortality rate compared with adults who had normal BMI values when they had coexisting hypertension or diabetes (adjusted hazard ratio = 0.50; 95% CI 0.30, 0.81 for hypertension and adjusted hazard ratio=0.41; 95% CI 0.18, 0.89 for diabetes). CONCLUSIONS: The study demonstrates that underweight people have a higher risk of death, and overweight and mildly obese people have a lower risk of death, compared with people of normal weight among middle-aged and older adults. An optimal BMI may be based on the individual, who exhibits pre-existing diseases or not.
Subject(s)
Body Mass Index , Cause of Death , Obesity/mortality , Thinness/mortality , Aged , Diabetes Mellitus , Female , Humans , Hypertension/complications , Male , Middle Aged , Overweight/mortality , Prospective Studies , Reference Values , Risk Factors , Taiwan/epidemiologyABSTRACT
BACKGROUND: We conducted a nationwide population-based cohort study to investigate the effects of asthma on the risk of stroke development in an Asian population. MATERIALS AND METHODS: Newly diagnosed asthmatic patients aged ≥ 18 years were identified, and asthma-free controls were randomly selected from the general population and frequency matched according to age, sex and index year using records obtained from the National Health Insurance Research Database between 2000 and 2010. Both cohorts were followed up until the end of 2011 to measure the incidence of stroke. The risk of stroke was analysed using Cox proportional hazard regression models, including factors such as sex, age and comorbidities. RESULTS: We followed the asthmatic patients for 104 697 person-years and followed the nonasthmatic people for 426 729 person-years. The incidence density rate of stroke increased in all of the groups of asthmatic patients compared with that of the controls when stratified according to sex, age and comorbidities. The hazard ratio (HR) of stroke was 1·37-fold greater for the asthmatic cohort, compared with that for the nonasthmatic cohort, after adjusting for sex, age and comorbidities. The adjusted HR of developing stroke substantially increased with older age and the increased frequency of asthmatic exacerbation and hospitalization. The patients receiving beta-2 agonists as a treatment exhibited a significantly greater risk of stroke compared with the patients receiving only inhaled corticosteroids, after adjusting for covariates. CONCLUSION: Asthma may be an independent risk factor for stroke, and its severity exhibits a dose response of stroke development.
Subject(s)
Asthma/complications , Stroke/etiology , Adult , Aged , Asthma/epidemiology , Case-Control Studies , Female , Hospitalization/statistics & numerical data , Humans , Male , Middle Aged , Prognosis , Risk Factors , Stroke/epidemiology , Taiwan/epidemiology , Young AdultABSTRACT
In this work, the hemocompatibility of polyampholyte copolymers from the mixed-charge copolymerization of negatively charged 3-sulfopropyl methacrylate (SA) and positively charged [2-(methacryloyloxy)ethyl] trimethylammonium (TMA) was studied. Charge-bias variation of the prepared poly(SA-co-TMA) copolymers can be controlled using the regulated SA and TMA monomer ratio via homogeneous free radical copolymerization. A systematic study of how charge-bias variations in poly(SA-co-TMA) copolymers affect the hemocompatibility in human blood plasma was reported. The hydrodynamic size of prepared polymers and copolymers is determined to illustrate the correlations between intermolecular cationic/anionic associations and the blood compatibility of polySA, poly(SA-co-TMA), and polyTMA suspensions in human blood plasma. It was found that the protein resistance and hydration capability of prepared copolymers can be effectively controlled by regulating the charge balance of the SA/TMA compositions in poly(SA-co-TMA). The results suggest that polyampholyte copolymers of poly(SA-co-TMA) with overall charge neutrality have a high hydration capability and the best antifouling, anticoagulant, and antihemolytic activities as well as zwitterionic sulfobetaine-based homopolymers when in contact with blood plasma at human body temperature.
Subject(s)
Biocompatible Materials/chemistry , Polymers/chemistry , Biocompatible Materials/adverse effects , Humans , Methacrylates/chemistry , Polymers/adverse effectsABSTRACT
WJ1376-1 and WJ1398-1 are new synthetic compounds developed based on the structure of the Chinese herbal medicine osthole. Previously, we reported that WJ1376-1 and WJ1398-1 can induce cell-cycle arrest by activating ATR kinase (ataxia telangiectasia and rad3 related kinase) and inhibiting the phosphorylation of Aurora A kinase. In this study, we determined that WJ1376-1 and WJ1398-1 strongly inhibited the migration and invasion in human colorectal cancer cells at concentrations as low as 1µM. In the transforming growth factor (TGF)-ß-induced epithelial-mesenchymal transition model, WJ1376-1 and WJ1398-1 potently downregulated the transcription factor Snail1, the mesenchymal protein vimentin, and matrix metalloprotease-9, but upregulated the epithelial protein E-cadherin. WJ1376-1 and WJ1398-1 also inhibited the TGF-ß-induced phosphorylation of Smad2 and of Akt at Ser 473, and the nuclear translocation of Smad2 was substantially lower in WJ1376-1- and WJ1398-1-treated cells than it was in control cells. In transient transfection experiments, we observed that WJ1376-1 and WJ1398-1 strongly inhibited TGF-ß-stimulated activity of a Smad reporter. Finally, WJ1376-1 and WJ1398-1 blocked TGF-ß-induced phosphorylation of the TGF-ß Type I receptor (TGF-ßRI). These results suggest that WJ1376-1 and WJ1398-1 inhibit cell migration and invasion by suppressing TGF-ßRI phosphorylation and subsequently hindering both Smad2 and phosphatidylinositol 3-kinase/Akt signaling pathways.
Subject(s)
Adenocarcinoma/drug therapy , Cell Movement/drug effects , Colorectal Neoplasms/drug therapy , Coumarins/pharmacology , Hydroxamic Acids/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Smad2 Protein/metabolism , Adenocarcinoma/genetics , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Cell Survival/drug effects , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Epithelial-Mesenchymal Transition/drug effects , HCT116 Cells , Humans , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-akt/genetics , RNA/chemistry , RNA/genetics , Receptor, Transforming Growth Factor-beta Type I , Receptors, Transforming Growth Factor beta/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Smad2 Protein/genetics , Transforming Growth Factor beta/metabolismABSTRACT
Studies on the association between asthma and pulmonary thromboembolism are considerably limited. We investigated whether pulmonary embolism is associated with asthma using a nationwide cohort study. We identified 31,356 patients with newly diagnosed asthma in 2002-2008 and 125,157 individuals without asthma randomly selected from the general population, frequency matched by age, sex and index year using the National Health Insurance Research Database. Both cohorts were followed-up until the end of 2010 to measure the incidence of pulmonary embolism. Cox proportional hazards regression analysis was used to measure the hazard ratio of pulmonary embolism for the asthmatic cohort, compared with the nonasthmatic cohort. We followed 186,182 person-years for asthmatic patients and 743,374 person-years for nonasthmatic subjects. The hazard ratio of pulmonary embolism was 3.24 for the asthmatic cohort, compared with the nonasthmatic cohort after adjusting for sex, age, comorbidities and oestrogen supplementation. The risk of developing pulmonary embolism significantly increased with the increased frequency of asthma exacerbation and hospitalisation. This nationwide cohort study suggests that the risk of developing pulmonary embolism is significantly increased in asthmatic patients compared to the general population. Frequent asthma exacerbation and hospitalisation are significantly associated with pulmonary embolism risk.
Subject(s)
Asthma/complications , Pulmonary Embolism/complications , Adult , Aged , Asthma/diagnosis , Asthma/epidemiology , Cohort Studies , Comorbidity , Female , Health Surveys , Humans , Incidence , Kaplan-Meier Estimate , Male , Middle Aged , Proportional Hazards Models , Pulmonary Embolism/diagnosis , Pulmonary Embolism/epidemiology , Risk Factors , Taiwan/epidemiology , Treatment OutcomeABSTRACT
In this work, the hemocompatibility of zwitterionic polypropylene (PP) fibrous membranes with varying grafting coverage of poly(sulfobetaine methacrylate) (PSBMA) via plasma-induced surface polymerization was studied. Charge neutrality of PSBMA-grafted layers on PP membrane surfaces was controlled by the low-pressure and atmospheric plasma treatment in this study. The effects of grafting composition, surface hydrophilicity, and hydration capability on blood compatibility of the membranes were determined. Protein adsorption onto the different PSBMA-grafted PP membranes from human fibrinogen solutions was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. Blood platelet adhesion and plasma clotting time measurements from a recalcified platelet-rich plasma solution were used to determine if platelet activation depends on the charge bias of the grafted PSBMA layer. The charge bias of PSBMA layer deviated from the electrical balance of positively and negatively charged moieties can be well-controlled via atmospheric plasma-induced interfacial zwitterionization and was further tested with human whole blood. The optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and keeps its original blood-inert property of antifouling, anticoagulant, and antithrmbogenic activities when it comes into contact with human blood. This work suggests that the hemocompatible nature of grafted PSBMA polymers by controlling grafting quality via atmospheric plasma treatment gives a great potential in the surface zwitterionization of hydrophobic membranes for use in human whole blood.
Subject(s)
Betaine/analogs & derivatives , Biocompatible Materials/chemistry , Membranes, Artificial , Plasma/chemistry , Polypropylenes/chemistry , Adsorption , Anticoagulants/chemistry , Anticoagulants/pharmacology , Betaine/chemistry , Biocompatible Materials/pharmacology , Blood Proteins/chemistry , Humans , Hydrophobic and Hydrophilic Interactions , Methacrylates/chemistry , Platelet Adhesiveness/drug effects , Surface PropertiesABSTRACT
PKC plays a pivotal role in mediating monocyte adhesion; however, the underlying mechanisms of PKC-mediated cell adhesion are still unclear. In this study, we elucidated the signaling network of phorbol ester PMA-stimulated human monocyte adhesion. Our results with pharmacological inhibitors suggested the involvement of AMPK, Syk, Src and ERK in PKC-dependent adhesion of THP-1 monocytes to culture plates. Biochemical analysis further confirmed the ability of PMA to activate these kinases, as well as the involvement of AMPK-Syk-Src signaling in this event. Direct protein interaction between AMPK and Syk, which requires the kinase domain of AMPK and linker region of Syk, was observed following PMA stimulation. Notably, we identified Syk as a novel downstream target of AMPK; AICAR can induce Syk phosphorylation at Ser178 and activation of this kinase. However, activation of AMPK alone, either by stimulation with AICAR or by overexpression, is not sufficient to induce monocyte adhesion. Studies further demonstrated that PKC-mediated ERK signaling independent of AMPK activation is also involved in cell adhesion. Moreover, AMPK, Syk, Src and ERK signaling were also required for PMA to induce THP-1 cell adhesion to endothelial cells as well as to induce adhesion response of human primary monocytes. Taken together, we propose a bifurcated kinase signaling pathway involved in PMA-mediated adhesion of monocytes. PKC can activate LKB1/AMPK, leading to phosphorylation and activation of Syk, and subsequent activation of Src and FAK. In addition, PKC-dependent ERK activation induces a coordinated signal for cytoskeleton rearrangement and cell adhesion. For the first time we demonstrate Syk as a novel substrate target of AMPK, and shed new light on the role of AMPK in monocyte adhesion, in addition to its well identified functions in energy homeostasis.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , MAP Kinase Signaling System/physiology , Monocytes/enzymology , Protein Kinase C/metabolism , Protein-Tyrosine Kinases/metabolism , AMP-Activated Protein Kinase Kinases , Carcinogens/pharmacology , Cell Adhesion/drug effects , Cell Adhesion/physiology , Cell Line , Cytoskeleton/metabolism , Energy Metabolism/drug effects , Energy Metabolism/physiology , Enzyme Activation/drug effects , Enzyme Activation/physiology , Humans , MAP Kinase Signaling System/drug effects , Monocytes/cytology , Protein Serine-Threonine Kinases/metabolism , Syk Kinase , Tetradecanoylphorbol Acetate/pharmacology , src-Family Kinases/metabolismABSTRACT
Endoplasmic reticulum (ER) stress is induced in infectious and inflammatory conditions, but its role in inflammatory responses still remains elusive. In this study we found tunicamycin (TM) and brefeldin A (BFA), two ER stressors, could attenuate lipopolysaccharide (LPS)-elicited inducible nitric oxide synthase (iNOS) gene expression in murine RAW264.7 macrophages, and this effect was not resulting from the effects on IKK or MAPKs activation. However, ER stressors could block NF-κB binding to the iNOS promoter in late-phase signaling evoked by LPS. Results indicated that inhibition of RelB nuclear translocation and p300 expression are involved in the anti-inflammatory actions of ER stressors. We also found that ER stressors could block LPS- and IFN (α, ß, and γ)-mediated STAT1 phosphorylation. Our results suggest that activation of MKP-1 via a Ca/calmodulin/calcineurin pathway accounts for the inhibitory effect of ER stressors on IFN signaling. MKP-1 was downregulated by IFN-γ and is a newly identified protein phosphatase targeting STAT1. Taken together, these results indicate that multiple mechanisms are involved in the inhibition of LPS-induced iNOS gene expression by ER stressors. These include downregulation of RelB and p300, upregulation of MKP-1, and inhibition of the JAK/STAT signaling pathway.
Subject(s)
Endoplasmic Reticulum Stress/drug effects , Lipopolysaccharides/pharmacology , Nitric Oxide Synthase Type II/antagonists & inhibitors , Animals , Anti-Bacterial Agents/pharmacology , Brefeldin A/pharmacology , Cell Line , Down-Regulation/drug effects , Dual Specificity Phosphatase 1/metabolism , Histones/metabolism , Interferon-gamma/pharmacology , Janus Kinases/metabolism , Mice , NF-kappa B/metabolism , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type II/metabolism , Phosphorylation , Promoter Regions, Genetic , Protein Binding , STAT1 Transcription Factor/metabolism , Signal Transduction/drug effects , Transcription Factor RelB/metabolism , Tunicamycin/pharmacology , p300-CBP Transcription Factors/metabolismABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: The Ger-Gen-Chyn-Lian-Tang (GGCLT), an officially standardized mixture of Chinese herbal medicines, consists of Puerariae Radix, Scutellariae Radix, Coptidis Rhizoma and Glycyrrhizae Radix in a ratio of 8:3:3:2. In this study, we evaluated the benefits of GGCLT in atherosclerotic progression. METHODS: The major constituents of GGCLT were analyzed by HPLC. ApoE-/- mice taken 0.15% cholesterol diet were orally given vehicle or GGCLT (2 g/kg/day) for 12 weeks. Serum levels of lipid and glucose were analyzed, and atherosclerosis was examined by histological analyses. Cultures of vascular smooth muscle cells, hepatocytes and bone marrow-derived macrophages were used to investigate the action mechanisms of GGCLT. RESULTS: Our quantitation results indicated that GGCLT contains puerarin, daidzin, daidzein, baicalin, baicalein, wogonin, palmatine, coptisine, berberine and glycyrrhizin. GGCLT decreased serum levels of total cholesterol and LDL, but not TG and HDL in ApoE-/- mice. In parallel, GGCLT treatment reduced atherosclerotic lesions and collagen expression in atheroma plaques. In vascular smooth muscle cells, GGCLT could reduce cell migration, but failed to affect cell viability and proliferation. In hepatocytes, GGCLT can reduce lipid accumulation, and this action was accompanied by the activation of AMPK, upregulation of PPARs, and downregulation of FAS. Pharmacological approach indicated that the latter two events contributing to the anti-lipogenesis is resulting from AMPK pathway, and the lipid lowering effect of GGCLT in hepatocytes is mediated by AMPK and PPARα pathways. Meanwhile, two of the major components of GGCLT, berberine and puerarin, also activated AMPK and decreased lipid accumulation in hepatocytes with berberine of higher efficacy. Besides in hepatocytes, AMPK signaling was also activated by GGCLT in vascular smooth muscle cells and macrophages. CONCLUSIONS: These results demonstrate the anti-atherosclerotic action of Chinese medicine mixture GGCLT in ApoE-/- atherosclerotic mouse model. Mechanistic study suggests that activation of AMPK and PPARα in hepatocytes leading to a decrease of lipid formation contributes to the beneficial action of GGCLT in atherosclerosis treatment.
Subject(s)
Atherosclerosis/drug therapy , Cardiotonic Agents/therapeutic use , Drugs, Chinese Herbal/therapeutic use , AMP-Activated Protein Kinases/metabolism , Animals , Aorta, Thoracic/cytology , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Atherosclerosis/metabolism , Cardiotonic Agents/pharmacology , Cell Cycle/drug effects , Cell Movement/drug effects , Cell Proliferation/drug effects , Cell Survival/drug effects , Cells, Cultured , Coptis chinensis , Drugs, Chinese Herbal/pharmacology , Glycyrrhiza , Hepatocytes/drug effects , Hepatocytes/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Myocytes, Smooth Muscle/drug effects , Myocytes, Smooth Muscle/physiology , Peroxisome Proliferator-Activated Receptors/metabolism , Pueraria , Rats , Rats, Wistar , Scutellaria baicalensisABSTRACT
OBJECTIVES: Although the application of cardiac implantable electronic devices (CIED) has greatly increased over the past few decades, CIED endocarditis is becoming a challenging scenario in clinical practice. Recently, Staphylococcus lugdunensis has emerged as a pathogen in CIED endocarditis. However, a detailed phenotypic characterization has not been addressed. METHODS: We conducted a systematic literature review covering the period between 1989 and 2011 using the PubMed, Medline, Cochrane, and Embase databases. All cases included had a CIED in use and met the modified Duke criteria for infective endocarditis, and all had isolates of S. lugdunensis. The clinical features, predisposing conditions, echocardiographic findings, and therapeutic strategies/outcomes were evaluated. Polymorphonuclear neutrophil functions were examined to test whether the defect of innate immunity may play a permissive role in host susceptibility to tissue destruction in S. lugdunensis endocarditis. RESULTS: Eleven patients with CIED endocarditis caused by S. lugdunensis were identified. Their mean age was 61.7±11.2 years, and there was a male preponderance (72.7%). Six patients (54.5%) had undergone re-manipulation of the pacing system within a few months to years before the occurrence of clinical symptoms. The median time of symptoms before the diagnosis of CIED endocarditis was 60 days. On echocardiography, vegetations in the CIED were detected in nine cases (81.8%). Nine patients (81.8%) underwent surgical removal of the entire device, and one patient received medical treatment alone. The overall mortality rate was 18.2%. One patient had a septic perforation of the ventricular septum, with a high serum level of N-terminal prohormone of brain natriuretic peptide (NT-pro-BNP) in the absence of pump failure. The assessment of polymorphonuclear neutrophil (PMN) functions revealed normal PMN responses to the various stimuli and normal oxidative burst responses. CONCLUSIONS: Identification and differentiation of staphylococcal species in a timely manner would allow us to intervene more aggressively at an earlier stage to prevent unfavorable outcomes. Clinicians should never consider the isolation of S. lugdunensis as contamination. In selected individuals, therapeutic abstention may be preferable to exposing patients to a high risk of S. lugdunensis CIED endocarditis due to re-manipulation of the pacing system. The prognostic value of NT-pro-BNP warrants further investigations.
Subject(s)
Endocarditis, Bacterial/microbiology , Pacemaker, Artificial/adverse effects , Prosthesis-Related Infections/microbiology , Staphylococcal Infections/microbiology , Staphylococcus lugdunensis/isolation & purification , Aged , Device Removal , Echocardiography/methods , Endocarditis, Bacterial/blood , Endocarditis, Bacterial/diagnostic imaging , Female , Humans , Natriuretic Peptide, Brain/blood , Neutrophils/immunology , Peptide Fragments/blood , Prosthesis-Related Infections/blood , Prosthesis-Related Infections/diagnostic imaging , Reoperation , Risk Factors , Staphylococcal Infections/blood , Staphylococcal Infections/diagnostic imaging , Time Factors , Ultrasonography, Doppler, ColorABSTRACT
The management of life-threatening complications in HIV-associated immune reconstitution syndrome is becoming a challenging scenario in emergency practice, especially in the era of highly active antiretroviral therapy paralleled by increased worldwide incidence of HIV infection. Here, we described a 37-year-old woman with acute hypoxic respiratory failure, acute renal failure, and hypercalcemic crisis as the presenting features of HIV-associated immune reconstitution syndrome. In this patient, the restored granulomatous host response toward isolated pulmonary Mycobacterium avium complex infection led to a near-fatal catastrophe. This report reinforces the importance of introducing a rapid, systematic approach of hypercalcemia at the emergency department and the need for clinicians to maintain awareness of this distinct manifestation.