ABSTRACT
The potential of natural products as pharmaceutical and agricultural agents is based on their large structural diversity, resulting in part from modifications of the backbone structure by tailoring enzymes during biosynthesis. Flavin-dependent monooxygenases (FMOs), as one such group of enzymes, play an important role in the biosynthesis of diverse natural products, including cyclodipeptide (CDP) derivatives. The FMO PboD was shown to catalyze C-3 hydroxylation at the indole ring of cyclo-l-Trp-l-Leu in the biosynthesis of protubonines, accompanied by pyrrolidine ring formation. PboD substrate promiscuity was investigated in this study by testing its catalytic activity toward additional tryptophan-containing CDPs in vitro and biotransformation in Aspergillus nidulans transformants bearing a truncated protubonine gene cluster with pboD and two acetyltransferase genes. High acceptance of five CDPs was detected for PboD, especially of those with a second aromatic moiety. Isolation and structure elucidation of five pyrrolidine diketopiperazine products, with two new structures, proved the expected stereospecific hydroxylation and pyrrolidine ring formation. Determination of kinetic parameters revealed higher catalytic efficiency of PboD toward three CDPs consisting of aromatic amino acids than of its natural substrate cyclo-l-Trp-l-Leu. In the biotransformation experiments with the A. nidulans transformant, modest formation of hydroxylated and acetylated products was also detected.
Subject(s)
Aspergillus , Diketopiperazines , Aspergillus/enzymology , Aspergillus/chemistry , Aspergillus nidulans/enzymology , Aspergillus nidulans/metabolism , Diketopiperazines/chemistry , Diketopiperazines/metabolism , Flavins/metabolism , Hydroxylation , Mixed Function Oxygenases/metabolism , Mixed Function Oxygenases/chemistry , Molecular Structure , Peptides, Cyclic/chemistry , Peptides, Cyclic/metabolism , Substrate SpecificityABSTRACT
Preeclampsia (PE) is a pregnancy-specific syndrome with complex pathogenesis. The present study aimed to explore the role of heat shock protein B8 (HSPB8) and c-Myc in trophoblast cell dysfunction using a hypoxia/reoxygenation (H/R)-treated HTR8/SVneo cell model. HSPB8 expression in tissues of patients with PE was analyzed using the Gene Expression Omnibus database. Following detection of HSPB8 expression in H/R-stimulated HTR8/SVneo cells, HSPB8 was overexpressed by transfection of the gene with a HSPB8-specific plasmid. Cell Counting Kit-8, wound healing and Transwell assays were used to evaluate the proliferation, migration and invasion of HTR8/SVneo cells exposed to H/R conditions. Reactive oxygen species (ROS) were determined by 2,7-dichlorodihydrofluorescein diacetate staining. 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbo-cyanine iodide (JC-1) staining was applied to assess mitochondrial membrane potential. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were detected using the corresponding commercial kits. In addition, the induction of apoptosis was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Moreover, the Biogrid database predicted that HSPB8 was bound to c-Myc, and a co-immunoprecipitation (Co-IP) assay was used to verify this interaction. Subsequently, c-Myc expression was silenced to conduct rescue experiments in HTR8/SVneo cells exposed to H/R conditions and upregulated HSPB8 expression. Notably, reduced HSPB8 expression was noted in PE tissues and H/R-stimulated HTR8/SVneo cells. HSPB8 enforced expression promoted the proliferation, migration and invasion of HTR8/SVneo cells. Moreover, H/R caused an increase in ROS and MDA levels as well as in TUNEL staining and a decrease in aggregated JC-1 fluorescence and SOD activity levels, which were restored following HSPB8 overexpression. Co-IP confirmed the interaction between HSPB8 and c-Myc. Moreover, knockdown of c-Myc expression compromised the effects of HSPB8 upregulation on trophoblast cell dysfunction following induction of H/R. Collectively, the data indicated that HSPB8 could improve mitochondrial oxidative stress by binding to c-Myc to alleviate trophoblast cell dysfunction. The findings may provide new insights into the pathogenesis of PE and highlight the role of HSPB8/c-Myc in the prevention and treatment of PE in the future.
ABSTRACT
BACKGROUND: Poststroke spasticity (PSS) is a common complication of stroke. Current PSS treatments have been linked to high costs, lack of long-term effectiveness, and undesirable side effects. Vibrational and heated stone-needle therapy (VHS) has not been utilized to treat PSS, and its safety and effectiveness have yet to be proven by high-quality clinical research. OBJECTIVE: The aim of this study was to determine the effectiveness of VHS combined with meridian dredging exercise (MDE) in patients with PSS. METHODS: One hundred participants with stroke were included and randomly assigned to a treatment group (VHS plus MDEs) and a control group (MDEs alone). Patients in both groups were treated for 4 weeks. The primary outcome measures were the Modified Ashworth Scale (MAS) and Fugl-Meyer Assessment (FMA), while the secondary outcome measures were the Activity of Daily Living (ADL) Scale and Stroke-Specific Quality of Life Scale (SS-QOL). The evaluations were at baseline (T0) at 4 weeks of treatment (T1) and at 12 weeks of follow-up without treatment (T2). RESULTS: At T1 and T2, there were significant differences in MAS between the two groups (p = 0.001). From the perspective of distribution, the VHS plus MDE group had significant changes, and the group-time interactions of upper and lower extremities in FMA, ADL, and SS-QOL were statistically significant (p < 0.001), indicating that patients' symptoms improved after treatment. But the overall effect size is small, especially the effect size of improvement in SS-QOL at T1. CONCLUSION: VHS in combination with MDE can consistently alleviate PSS, enhance limb function, and improve the quality of life of patients with PSS. But we need to optimize the device further and observe the improvement of patients for a more extended period.
Subject(s)
Meridians , Quality of Life , Humans , Animals , Mice , Physical Therapy ModalitiesABSTRACT
Studies have demonstrated that exercise benefits executive function. However, it remains unclear which type of exercise is optimal for preserving executive function among young adults and the cerebral blood flow (CBF) mechanisms that underlie exercise-induced cognitive benefits. Therefore, this study aims to compare the intervention effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on executive function and the CBF mechanism. This was a double-blinded, randomized, controlled trial study conducted between October 2020 and January 2021 (ClinicalTrials.gov identifier: NCT04830059). Ninety-three healthy young adults (25.23 ± 2.18 years old; 49.82% male) were randomized into the HIIT (N = 33), MICT (N = 32), and control (N = 28) groups. Participants in exercise groups were guided to perform 40 min of HIIT and MICT three times a week for 12 weeks, while the control group received health education for the same period. The primary outcomes, changes in executive function assessed by the trail-making test (TMT), and CBF measured by transcranial Doppler flow analyzer (EMS-9WA), were evaluated before and after the interventions. The time taken to complete the TMT task improved significantly in the MICT group compared to the control group [ß = -10.175, 95%, confidence interval (CI) = -20.320, -0.031]. Additionally, the MICT group showed significant improvements in the pulsatility index (PI) (ß = 0.120, 95% CI = 0.018, 0.222), resistance index (RI) (ß = 0.043, 95% CI = 0.005, 0.082), and peak-systolic/end-diastolic velocity (S/D) (ß = 0.277, 95% CI = 0.048, 0.507) of CBF compared to the control group. The time taken to complete the TMT was associated with the velocity of peak-systolic (F = 5.414, P = 0.022), PI (F = 4.973, P = 0.012), and RI (F = 5.845, P = 0.006). Furthermore, the accuracy of TMT was associated with PI (F = 4.797, P = 0.036), RI (F = 5.394, P = 0.024), and S/D (F = 4.312, P = 0.05) of CBF. A 12-week MICT intervention improved CBF and executive function more effectively than HIIT among young adults. Furthermore, the findings suggest that CBF was one of the potential mechanisms underlying the cognitive benefits of exercise in young people. These results provide practical evidence supporting the promotion of regular exercise to maintain executive function and improve brain health.
Subject(s)
Cerebrovascular Circulation , Executive Function , Exercise , Humans , Male , Female , Young Adult , Adult , High-Intensity Interval TrainingABSTRACT
Cardiac fibrosis is the main pathological basis of diabetic cardiomyopathy (DCM), and endothelial-to-meschenymal transition (EndMT) is a key driver to cardiac fibrosis and plays an important role in the pathogenesis of DCM. Asymmetric dimethylarginine (ADMA), a crucial pathologic factor in diabetes mellitus, is involved in organ fibrosis. This study aims to evaluate underlying mechanisms of ADMA in DCM especially for EndMT under diabetic conditions. A diabetic rat model was induced by streptozotocin (STZ) injection, and human cardiac microvascular endothelial cells (HCMECs) were stimulated with high glucose to induce EndMT. Subsequently, the role of ADMA in EndMT was detected either by exogenous ADMA or by over-expressing dimethylarginine dimethylaminohydrolase 1 (DDAH1, degradation enzyme for ADMA) before high glucose stimulation. Furthermore, the relationships among forkhead box protein O1 (FoxO1), DDAH1 and ADMA were evaluated by FoxO1 over-expression or FoxO1 siRNA. Finally, we examined the roles of LncRNA DANCR in FoxO1/DDAH1/ADMA pathway and EndMT of HCMECs. Here, we found that EndMT in HCMECs was induced by high glucose, as evidenced by down-regulated expression of CD31 and up-regulated expression of FSP-1 and collagen â . Importantly, ADMA induced EndMT in HCMECs, and over-expressing DDAH1 protected from developing EndMT by high glucose. Furthermore, we demonstrated that over-expression of FoxO1-ADA with mutant phosphorylation sites of T24A, S256D, and S316A induced EndMT of HCMECs by down-regulating of DDAH1 and elevating ADMA, and that EndMT of HCMECs induced by high glucose was reversed by FoxO1 siRNA. We also found that LncRNA DANCR siRNA induced EndMT of HCMECs, activated FoxO1, and inhibited DDAH1 expression. Moreover, over-expression of LncRNA DANCR could markedly attenuated high glucose-mediated EndMT of HCMECs by inhibiting the activation of FoxO1 and increasing the expression of DDAH1. Collectively, our results indicate that LncRNA DANCR deficiency promotes high glucose-induced EndMT in HCMECs by regulating FoxO1/DDAH1/ADMA pathway.
Subject(s)
Endothelial Cells , RNA, Long Noncoding , Animals , Humans , Rats , Amidohydrolases/genetics , Amidohydrolases/metabolism , Arginine/metabolism , Endothelial Cells/metabolism , Fibrosis , Forkhead Box Protein O1/genetics , Forkhead Box Protein O1/metabolism , Glucose/pharmacology , RNA, Long Noncoding/genetics , Signal TransductionABSTRACT
Heparin has been documented to reduce myocardial injury caused by ischemia/reperfusion (I/R), but its clinical application is limited due to its strong intrinsic anticoagulant property. Some desulfated derivatives of heparin display low anticoagulant activity and may have potential value as therapeutic agents for myocardial I/R injury. In this study, we observed that 6-O-desulfated heparin, a desulfated derivative of heparin, shortened the activated partial thromboplastin time and exhibited lower anticoagulant activity compared with heparin or 2-O-desulfated heparin (another desulfated derivative of heparin). Then, we explored whether 6-O-desulfated heparin could protect against myocardial I/R injury, and elucidated its possible mechanisms. Administration of 6-O-desulfated heparin significantly reduced creatine kinase activity, myocardial infarct size and cell apoptosis in mice subjected to 30 min of myocardial ischemia following 2 h of reperfusion, accompanied by a reverse in miR-199a-5p elevation, klotho downregulation and reactive oxygen species (ROS) accumulation. In cultured H9c2 cells, the mechanism of 6-O-desulfated heparin against myocardial I/R injury was further explored. Consistent with the results in vivo, 6-O-desulfated heparin significantly ameliorated hypoxia/reoxygenation-induced injury, upregulated klotho and decreased miR-199a-5p levels and ROS accumulation, and these effects were reversed by miR-199a-5p mimics. In conclusion, these results suggested that 6-O-desulfated heparin with lower anticoagulant activity attenuated myocardial I/R injury through miR-199a-5p/klotho and ROS signaling. Our study may also indicate that 6-O-desulfated heparin, as an excellent heparin derivative, is a potential therapeutic agent for myocardial I/R injury.
Subject(s)
Heparin , Klotho Proteins , MicroRNAs , Myocardial Reperfusion Injury , Animals , Mice , Apoptosis , Disease Models, Animal , Heparin/pharmacology , Heparin/therapeutic use , Klotho Proteins/metabolism , MicroRNAs/genetics , Myocardial Reperfusion Injury/drug therapy , Myocardial Reperfusion Injury/metabolism , Signal TransductionABSTRACT
Six new glucosyloxybenzyl 2-hydroxy-2-isobutylsuccinates, pleionesides A-F (1-6), along with two known compounds (7, 8) were obtained from the pseudobulbs of Pleione grandiflora (Rolfe) Rolfe. The structures and absolute configurations of new compounds were established by HRESIMS and NMR data, along with acidic hydrolysis and alkaline hydrolysis experiments. Compounds 1-6 were tested for their anti-inflammatory activities on LPS-induced BV2 microglial cells. Amoung them, 2, 4 and 5 showed moderate activities with IC50 values of 73.4, 32.8 and 57.1 µM, respectively, compared with the positive control quercetin with an IC50 value of 28.3 µM.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Microglia/drug effects , Orchidaceae/chemistry , Animals , Anti-Inflammatory Agents/isolation & purification , Cell Line , China , Mice , Molecular Structure , Phytochemicals/isolation & purification , Phytochemicals/pharmacology , Plant Roots/chemistryABSTRACT
Thirteen compounds were isolated and purified from the leaves of Cinnamomum camphora by the macroporous resin,silica gel,and Sephadex LH-20 column chromatographies. Those compounds were further identified by IR,UV,MS,and NMR techniques:( 2 S)-1-( 3â³,4â³-methylenedioxy phenyl)-3-( 2',6'-dimethoxy-4'-hydroxyphenyl)-propan-2-ol( 1),( 2 R,3 R)-5,7-dimethoxy-3',4'-methylenedioxy flavanol( 2),9-hydroxysesamin( 3),sesamin( 4),piperitol( 5),kobusin( 6),(-)-aptosimon( 7),acuminatolide( 8),1ß,11-dihydroxy-5-eudesmene( 9),lasiodiplodin( 10),vanillin( 11),p-hydroxybenzaldehyde( 12),and p-hydroxybenzoic acid ethyl ester( 13). Compound 1 was a novel compound,and compounds 2,6,7,9 and 10 were isolated from Cinnamomum plants for the first time. Compounds 4,7 and 10 were found to possess good inhibitory effect on IL-6 production in LPS-induced BV2 cells at a concentration of 20 µmol·L-1 in the in vitro bioassay,with inhibition rates of 51. 26% ± 4. 13%,67. 82% ± 3. 77% and85. 81%±1. 19%,respectively.
Subject(s)
Cinnamomum camphora , Cinnamomum , Anti-Inflammatory Agents/pharmacology , Plant LeavesABSTRACT
Endothelial cell dysfunction is a prominent feature of diabetic cardiovascular complications, and endothelial cell senescence is considered to be an important contributor to endothelial dysfunction. Discoidin domain receptor 1 (DDR1) has been reported to be involved in atherogenesis and cerebral ischemia/reperfusion injury. In this study, we aimed to explore the role of DDR1 in endothelial cell senescence under diabetic conditions and elucidate the underlying mechanisms. A diabetic rat model was established by a single intraperitoneal injection of streptozocin (STZ) (60 mg/kg), which showed an increase in senescence-associated ß-galactosidase (SA-ß-gal) staining signal of thoracic aortic endothelium, impaired vascular structure and function, accompanied by an up-regulation of DDR1. Next, we verified the role of DDR1 in endothelial senescence and the underlying mechanisms in high glucose-treated human umbilical vein endothelial cells (HUVECs). Consistent with the in vivo findings, high glucose induced endothelial senescence, impaired endothelial function and elevated DDR1 expression, accompanied by the elevation of senescence-related genes p53 and p21 expression, and these effects were reversed by DDR1 siRNA. DDR1 has been documented to be a potential target of miR-199a-3p. Here, we found that miR-199a-3p was down-regulated by high glucose in the aorta tissue and HUVECs, while miR-199a-3p mimic significantly suppressed increased endothelial senescence and elevated DDR1 induced by high glucose. In conclusion, our data demonstrated that miR-199a-3p/DDR1/p53/p21 signaling pathway was involved in endothelial senescence under diabetic conditions, and therapeutic targeting DDR1 would be exploited to inhibit endothelial senescence owing to high glucose exposure.
Subject(s)
Discoidin Domain Receptor 1 , MicroRNAs , Animals , Cellular Senescence , Human Umbilical Vein Endothelial Cells , Humans , Rats , Signal TransductionABSTRACT
ABSTRACT: The SARS-CoV-2 pandemic has presented new challenges to food manufacturers. During the early phase of the pandemic, several large outbreaks of coronavirus disease 2019 (COVID-19) occurred in food manufacturing plants resulting in deaths and economic loss, with approximately 15% of personnel diagnosed as asymptomatic for COVID-19. Spread by asymptomatic and presymptomatic individuals has been implicated in large outbreaks of COVID-19. In March 2020, we assisted in implementation of environmental monitoring programs for SARS-CoV-2 in zones 3 and 4 of 116 food production facilities. All participating facilities had already implemented measures to prevent symptomatic personnel from coming to work. During the study period, from 17 March to 3 September 2020, 1.23% of the 22,643 environmental samples tested positive for SARS-CoV-2, suggesting that infected individuals were actively shedding virus. Virus contamination was commonly found on frequently touched surfaces such as doorknobs, handles, table surfaces, and sanitizer dispensers. Most processing plants managed to control their environmental contamination when they became aware of the positive findings. Comparisons of positive test results for plant personnel and environmental surfaces in one plant revealed a close correlation. Our work illustrates that environmental monitoring for SARS-CoV-2 can be used as a surrogate for identifying the presence of asymptomatic and presymptomatic personnel in workplaces and may aid in controlling infection spread.
Subject(s)
COVID-19 , SARS-CoV-2 , Environmental Monitoring , Humans , Plants, Edible , PrevalenceABSTRACT
Two new alkaloids, named hositisines A (1) and B (2), with two known alkaloids (3 and 4) were isolated from the stems of Ormosia hosiei Hemsl. et Wils. Their structures were confirmed by UV, HRESIMS, NMR spectra. The absolute configurations of 1 and 2 were determined by quantum ECD calculation and ECD, respectively. Compounds 1-3 could significantly reduce the LDH release at the concentration 50 µM, which showed they could strongly protect the PC12 cells exposed to oxygen and glucose deprivation/reoxygenation (OGD/R) injury.
Subject(s)
Alkaloids/isolation & purification , Fabaceae/chemistry , Plant Stems/chemistry , Alkaloids/chemistry , Animals , Carbon-13 Magnetic Resonance Spectroscopy , Glucose/deficiency , L-Lactate Dehydrogenase/metabolism , Oxygen/pharmacology , PC12 Cells , Proton Magnetic Resonance Spectroscopy , RatsABSTRACT
Blood-retinal barrier breakdown is the main pathological characteristics of diabetic retinopathy (DR). Asymmetric dimethylarginine (ADMA) was reported to be elevated in DR patients. In this study, we observed the dynamic profile of ADMA, retinal morphology and permeability of BRB at 2, 4 or 8 week of diabetic rats induced by a single intraperitoneal injection of streptozocin (60 mg/kg) and in cultured rat retinal pericytes pretreated with D-glucose (30 mM) for 1, 3, 5 and 7 days or ADMA (3, 10, 30 µM) for 24, 48 and 72 h, trying to explore the effects of ADMA on blood-retinal barrier in DR. Gap junction intercellular communication (GJIC) and the expression of blood-retinal barrier-specific component connexin 43 (Cx43) were examined in diabetic rats or cultured retinal pericytes to elucidate whether ADMA impacted blood-retinal barrier function via damaging Cx43-GJIC. The results showed that with increasing duration of diabetes, the ultrastructure of blood-retinal barrier of diabetic rats appeared cell junction damage, apoptosis of retinal pericytes and breakdown of barrier successively. The increases in retinal permeability, ADMA levels and Cx43 expression, and abnormal GJIC were observed in diabetic rats and retinal pericytes exposed to D-glucose (30 mM). A glucose-like effect was seen using ADMA or another L-arginine analogue NG-monomethyl-L-arginine or dimethylarginine dimethylaminohydrolases (DDAHs) siRNA, implicating that ADMA aggravated the breakdown of blood-retinal barrier via damaging Cx43-GJIC.
Subject(s)
Arginine/analogs & derivatives , Blood-Retinal Barrier/pathology , Diabetes Mellitus, Experimental/pathology , Diabetic Retinopathy/pathology , Pericytes/pathology , Animals , Apoptosis , Arginine/metabolism , Blood-Retinal Barrier/metabolism , Cell Communication , Cell Membrane Permeability , Cells, Cultured , Connexin 43/metabolism , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/metabolism , Diabetic Retinopathy/chemically induced , Diabetic Retinopathy/metabolism , Gap Junctions/pathology , Glucose/metabolism , Male , Pericytes/metabolism , Rats , Rats, Sprague-Dawley , Streptozocin/administration & dosage , Streptozocin/toxicityABSTRACT
Background: Previous studies have conflicting results on the association between socioeconomic status and stroke outcomes. Thus, this study aimed to investigate whether socioeconomic status is associated with the prognosis of ischemic stroke in Guangzhou, South China. Methods: A total of 622 patients with ischemic stroke who were admitted in the neurology department of five general hospitals in Guangzhou from May 2014 to October 2014 were included in the study. Socioeconomic status was measured based on education, income, caregiver, and insurance. The modified Rankin scale was used to evaluate the two years prognosis of patients with stroke. A multivariate logistic regression model was performed to determine the association between socioeconomic status and ischemic stroke prognosis. Results: In 2 years follow-up, 542 ischemic stroke patients were interviewed by telephone. Age ranged from 31 to 96 years, 65.5% of the patients were male. 33.9% of patients with ischemic stroke had a poor prognosis. After adjustment for age, sex, cardiovascular disease, behavior lifestyle, and severity of stroke, odds ratio for poor prognosis in patients with low income was 1.84 (95%CI 1.05-3.22), family caregiver 3.19 (95%CI 1.05-9.70), and no insurance 1.68 (95%CI 1.02-2.77). Conclusions: Patients with low income, family caregiver, and no insurance have a poorer prognosis after ischemic stroke that can be partly explained by intermediate variable in the patients' demographic characteristics, cardiovascular disease, behavior lifestyle, and stroke severity. Abbreviations: DALYs: disability-adjusted life years; SES: socioeconomic status; FMC: free medical care; MIUR: medical insurance for urban residents; MIUE: medical insurance for urban employees; NCMS: new rural cooperative medical scheme ; NIHSS: National Institute of Health Stroke Scale ; mRS: modified Rankin scale; OR: odds ratios; CI: confidence interval.
Subject(s)
Recovery of Function , Social Class , Stroke , Adult , Aged , Aged, 80 and over , China , Female , Humans , Male , Middle Aged , Prognosis , Risk FactorsABSTRACT
BACKGROUND: The association between socioeconomic status (SES) and stroke risk remains controversial around the world. It is not clear that the effect of SES on stroke in China due to the lack of relevant research. We aimed to assess the association between SES and risks of first-ever ischemic stroke in Guangzhou, China. METHODS: Cases were recruited from neurology department in the First Affiliated Hospital of Guangdong Pharmaceutical University during September 2016-October 2017. Age- and sex-matched controls were derived from surgical departments, over the same period. SES was assessed based on education, occupation, and income. Education was divided into ≤6 years, 6-9 years, 10-12 years, and > 12 years. Family monthly income per capita was categorized into ≤¥1000, ¥1001-3000, ¥3001-5000, and > ¥5001. Occupation was stratified into manual, non-manual, no job, and retired. A multivariate logistic regression model was used to determine the association between SES and risk of ischemic stroke. RESULTS: In total, 347 ischemic stroke patients and 347 controls were recruited, with mean ages of 60.54 ± 13.13 and 60.56 ± 13.07 years, respectively. After adjusting for confounding factors, odds ratio (OR) for 6-9 years of education was 2.63 (95% confidence interval [CI] 1.45-4.75); > 12 years, 2.18 (1.25-3.82) compared with those for < 6 years of education. ORs for the second lowest, third lowest, and highest incomes were 1.96 (1.21-3.15), 4.16 (2.39-7.22), and 2.83(1.25-6.39), respectively, compared with those for the lowest income. ORs for manual workers and non-manual workers were 1.95 (1.23-3.07) and 1.87 (1.05-3.33), compared with individuals without jobs. CONCLUSIONS: Higher SES is positively related with risks of ischemic stroke, explained by cardiovascular diseases and unhealthy lifestyles in Guangzhou, China. Thus, effective strategies such as extensive health education, promoting a healthy lifestyle, screening for risk factors to prevent stroke should be implemented to reduce ischemic stroke incidences among the high SES group.
Subject(s)
Brain Ischemia/epidemiology , Health Status Disparities , Social Class , Stroke/epidemiology , Aged , Case-Control Studies , China/epidemiology , Female , Humans , Incidence , Logistic Models , Male , Middle Aged , Multivariate Analysis , Risk AssessmentABSTRACT
Vascular calcification is highly associated with cardiovascular disease mortality, particularly in high-risk patients with diabetes and chronic kidney diseases (CKD). In blood vessels, intimal calcification is associated with atherosclerosis, whereas medial calcification is a nonocclusive process which leads to increased vascular stiffness and reduced vascular compliance. In the valves, calcification of the leaflets can change the mechanical properties of the tissue and result in stenosis. For many decades, vascular calcification has been noted as a consequence of aging. Studies now confirm that vascular calcification is an actively regulated process and shares many features with bone development and metabolism. This review provides an update on the mechanisms of vascular calcification including the emerging roles of the RANK/RANKL/OPG triad, osteoclasts, and microRNAs. Potential treatments adapted from osteoporosis and CKD treatments that are under investigation for preventing and/or regressing vascular calcification are also reviewed.
Subject(s)
Calcinosis/metabolism , Vascular Calcification/metabolism , Vascular Calcification/therapy , Animals , Antibodies, Monoclonal, Humanized/chemistry , Atherosclerosis/pathology , Calcinosis/therapy , Calcium/metabolism , Chelating Agents/chemistry , Denosumab , Diphosphonates/chemistry , Humans , Mice , MicroRNAs/metabolism , Osteoclasts/cytology , Osteoclasts/metabolism , Osteoporosis/therapy , Osteoprotegerin/metabolism , RANK Ligand/metabolism , Receptor Activator of Nuclear Factor-kappa B/metabolism , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/therapy , Teriparatide/chemistry , Tunica Intima/pathology , Tunica Media/pathology , Vascular Diseases/complicationsABSTRACT
Osteoclasts are bone-resorbing cells that are critical for the normal formation and maintenance of teeth and skeleton. Osteoclast deficiency can contribute to heterotopic ossification (HO), a pathology that is particularly detrimental to the mechanical functions of joints, valves and blood vessels. On the other hand, osteoclast over-activity is a major cause of osteoporosis. A reliable method for controlled generation of osteoclasts would be useful as a potential autologous cell therapy for HO, as well as high-throughput drug screening for anti-osteoporotic drugs. In this report, we describe the development of a cell engineering approach to control monocytic precursor cell differentiation to osteoclasts. Oligomerization of receptor activator of nuclear factor κB (RANK) is known to be essential for osteoclast differentiation from monocyte/macrophage precursors. We engineered a murine monocytic cell line, RAW264.7 to express a fusion protein comprising the intracellular RANK signaling domain and FK506-derived dimerization domains that bind to a small molecule chemical inducer of dimerization (CID). Virally infected cells expressing this fusion protein were treated with CID and dose-dependent induction of tartrate-resistant acid phosphatase activity, as well as multinucleated osteoclast formation were observed. Furthermore, NF-κB signaling was upregulated in a CID-dependent fashion, demonstrating effective RANK intracellular signaling. Functionally CID-induced osteoclasts had robust mineral resorptive activity in both two-dimensional and three-dimensional in vitro resorption assays. In addition, the CID-induced osteoclasts have the same life span as native RANKL-induced osteoclasts. Most importantly and crucially, the engineered cells differentiated into osteoclasts that were resistant to the potent osteoclast inhibitor, osteoprotegerin. Taken together, these studies are the first to describe a method for inducible control of monocytic precursor differentiation to osteoclasts that may be useful for future development of an engineered autologous cell therapy as well as high-throughput drug testing systems to treat diseases of osteoclast over-activity that are independent of osteoprotegerin.
Subject(s)
Cell Differentiation , Myeloid Progenitor Cells/metabolism , NF-kappa B/metabolism , Osteoclasts/metabolism , RANK Ligand/metabolism , Animals , Cell Line , Myeloid Progenitor Cells/cytology , NF-kappa B/genetics , Osteoclasts/cytology , RANK Ligand/geneticsABSTRACT
Trypanosomatids, such as the sleeping sickness parasite Trypanosoma brucei, contain a â¼ 20S RNA-editing complex, also called the editosome, which is required for U-insertion/deletion editing of mitochondrial mRNAs. The editosome contains a core of 12 proteins including the large interaction protein A1, the small interaction protein A6, and the editing RNA ligase L2. Using biochemical and structural data, we identified distinct domains of T. brucei A1 which specifically recognize A6 and L2. We provide evidence that an N-terminal domain of A1 interacts with the C-terminal domain of L2. The C-terminal domain of A1 appears to be required for the interaction with A6 and also plays a key role in RNA binding by the RNA-editing ligase L2 in trans. Three crystal structures of the C-terminal domain of A1 have been elucidated, each in complex with a nanobody as a crystallization chaperone. These structures permitted the identification of putative dsRNA recognition sites. Mutational analysis of conserved residues of the C-terminal domain identified Arg703, Arg731 and Arg734 as key requirements for RNA binding. The data show that the editing RNA ligase activity is modulated by a novel mechanism, i.e. by the trans-acting RNA binding C-terminal domain of A1.
Subject(s)
Carbon-Oxygen Ligases/chemistry , Mitochondrial Proteins/chemistry , Protozoan Proteins/chemistry , Trypanosoma brucei brucei , Binding Sites , Carbon-Oxygen Ligases/metabolism , Mitochondrial Proteins/metabolism , Models, Molecular , Protein Interaction Domains and Motifs , Protozoan Proteins/metabolism , RNA Editing , RNA, Double-Stranded/metabolism , Trypanosoma brucei brucei/geneticsABSTRACT
The neuromedin B receptor (Nmbr) is an important physiological regulator of spontaneous activities and stress responses through different cascades as well as its autocrine and paracrine effects. Previous studies have revealed that neuromedin B (Nmb) and its receptor signal via the Rela (also known as p65)/Il6 pathway in a mouse model of pregnancy. This study investigated the mechanism of Nmbr signaling via the Rela/p65-Il6 pathway and regulation of the concentration of intracellular free calcium ([Ca(2+)](i)) during the onset of labor in primary mouse myometrial cell cultures isolated from mice in term labor. Data demonstrated Nmbr agonist-mediated upregulation of the DNA binding activity of Rela/p65, Il6 expression, and [Ca(2+)](i) in a concentration-dependent manner. Furthermore, a significant correlation was observed between DNA binding activity of Rela/p65 and Il6 expression. Moreover, this up-regulation was blocked by Nmbr and Rela/p65 knockdown, achieved by RNA interference (RNAi) technology. No significant differences were identified in the inhibition of Il6 expression as a result of Nmbr or Rela/p65 knockdown. However, significant differences were observed between the [Ca(2+)](i) in Rela/p65-specific group and that in the Nmbr-specific small interfering RNA (siRNA)-treated groups. These data demonstrated that the Nmb/Nmbr interaction in pregnant myometrial primary cells in vitro predominantly influenced uterine activity through regulation of Il6 expression via the Rela/p65 pathway, although the effects of Nmbr on [Ca(2+)](i) involved several pathways that remain to be elucidated.
Subject(s)
Interleukin-6/biosynthesis , Myometrium/physiology , Neurokinin B/analogs & derivatives , Receptors, Bombesin/physiology , Transcription Factor RelA/physiology , Animals , Calcium/physiology , Cells, Cultured , Female , Labor Onset/physiology , Mice , Mice, Inbred BALB C , Neurokinin B/physiology , Pregnancy , RNA Interference/physiology , Signal Transduction/physiology , Up-Regulation/physiologyABSTRACT
The parasite Trypanosoma brucei, the causative agent of sleeping sickness across sub-Saharan Africa, depends on a remarkable U-insertion/deletion RNA editing process in its mitochondrion. A approximately 20 S multi-protein complex, called the editosome, is an essential machinery for editing pre-mRNA molecules encoding the majority of mitochondrial proteins. Editosomes contain a common core of twelve proteins where six OB-fold interaction proteins, called A1-A6, play a crucial role. Here, we report the structure of two single-strand nucleic acid-binding OB-folds from interaction proteins A3 and A6 that surprisingly, form a heterodimer. Crystal growth required the assistance of an anti-A3 nanobody as a crystallization chaperone. Unexpectedly, this anti-A3 nanobody binds to both A3(OB) and A6, despite only ~40% amino acid sequence identity between the OB-folds of A3 and A6. The A3(OB)-A6 heterodimer buries 35% more surface area than the A6 homodimer. This is attributed mainly to the presence of a conserved Pro-rich loop in A3(OB). The implications of the A3(OB)-A6 heterodimer, and of a dimer of heterodimers observed in the crystals, for the architecture of the editosome are profound, resulting in a proposal of a 'five OB-fold center' in the core of the editosome.
Subject(s)
Mitochondrial Proteins/chemistry , Protozoan Proteins/chemistry , RNA-Binding Proteins/chemistry , Single-Chain Antibodies/chemistry , Amino Acid Sequence , Cross Reactions , Crystallography, X-Ray , Dimerization , Mitochondrial Proteins/immunology , Models, Molecular , Molecular Sequence Data , Protein Multimerization , Protein Structure, Tertiary , Protozoan Proteins/immunology , RNA Editing , RNA-Binding Proteins/immunology , Single-Chain Antibodies/immunologyABSTRACT
Several major global diseases are caused by single-cell parasites called trypanosomatids. These organisms exhibit many unusual features including a unique and essential U-insertion/deletion RNA editing process in their single mitochondrion. Many key RNA editing steps occur in â¼20S editosomes, which have a core of 12 proteins. Among these, the "interaction protein" KREPA6 performs a central role in maintaining the integrity of the editosome core and also binds to ssRNA. The use of llama single domain antibodies (VHH domains) accelerated crystal growth of KREPA6 from Trypanosoma brucei dramatically. All three structures obtained are heterotetramers with a KREPA6 dimer in the center, and one VHH domain bound to each KREPA6 subunit. Two of the resultant heterotetramers use complementarity determining region 2 (CDR2) and framework residues to form a parallel pair of beta strands with KREPA6 - a mode of interaction not seen before in VHH domain-protein antigen complexes. The third type of VHH domain binds in a totally different manner to KREPA6. Intriguingly, while KREPA6 forms tetramers in solution adding either one of the three VHH domains results in the formation of a heterotetramer in solution, in perfect agreement with the crystal structures. Biochemical solution studies indicate that the C-terminal tail of KREPA6 is involved in the dimerization of KREPA6 dimers to form tetramers. The implications of these crystallographic and solution studies for possible modes of interaction of KREPA6 with its many binding partners in the editosome are discussed.
