[Cellular and molecular mechanisms of anti-inflammatory effect of peroxisome proliferator-activated receptor α]

Objective: To investigate the cellular and molecular mechanisms of the anti-inflammatory effect of peroxisome proliferator-activated receptor α (PPARα). Methods: Firstly, bone marrow-derived macrophages (BMDMs) were randomly divided into control group, LPS group, WY14643 10 μmol/L group, WY14643 25 μmol/L group, and WY14643 50 μmol/L group using a random number table. Secondly, BMDMs were randomly divided into LPS group, WY14643+LPS group, and 3-MA+WY14643+LPS group. Primary BMDMs were stimulated by LPS (20 ng/ml) to establish the cellular model of inflammation. The selective agonist of PPARα WY14643 was administered at doses of 10, 25, and 50 μmol/L (50 μmol/L for the second part of the experiment) at 2 hours before model establishment. The autophagy inhibitor 3-MA was administered at a dose of 10 mmol/L at 2 hours before model establishment. The cells in the control group were treated with dimethylsulfoxide (DMSO) at the same dose. The cells were transfected with GFP-LC3 plasmids at 24 hours before model establishment. The cells were harvested at 6 hours after LPS stimulation and related tests were performed. Green fluorescent protein was measured under a fluorescence microscope to evaluate autophagy activity. Quantitative real-time PCR was used to measure tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and mRNA expression of chemokine-1 (CXCL-1) and chemokine-10 (CXCL-10). Western blot was used to measure PPARα and autophagy-related proteins LC3, ATG-5, ATG-7, and LAMP-1. A one-way analysis of variance was used for comparison between groups, and the LSD-t test was used for comparison between any two groups. Results: In vitro, PPARα activation inhibited LPS-induced inflammatory response in primary macrophages in a dose-dependent manner. The results of gene expression showed that the relative expression of TNF-α, IL-1β, IL-6, CXCL-1, and CXCL-10 was as follows in the control group, LPS group, WY14643 10 μmol group, WY14643 25 μmol group, and WY14643 50 μmol group: TNF-α (0.085±0.009, 4.065±0.544, 3.281±0.368, 1.780±0.293, and 0.781±0.303, P < 0.01), IL-1β (0.081±0.017, 0.776±0.303, 0.225±0.154, 0.161±0.068, and 0.101±0.025, P < 0.05), IL-6 (0.041±0.011, 0.189±0.014, 0.144±0.033, 0.126±0.013, and 0.048±0.015, P < 0.01), CXCL-1 (0.051±0.011, 0.515±0.145, 0.356±0.078, 0.257±0.068, and 0.069±0.030, P < 0.01), and CXCL-10 (0.126±0.068, 0.831±0.093, 0.508±0245, 0.474±0.047, and 0.204±0.021, P < 0.05). In vitro, PPARα activation promoted autophagy in vitro in a dose-dependent manner. The results of Western blot and fluorescence microscopy in the control group, LPS group, WY14643 10 μmol group, WY14643 25 μmol group, and WY14643 50 μmol group showed that the expression of autophagy-related proteins and autophagosome formation gradually increased with the increasing concentration of WY14643. In vitro, WY14643 inhibited autophagy, promoted inflammatory response in primary macrophages, and reversed the anti-inflammatory effect of PPARα. The results of gene expression showed that the relative expression of TNF-α, IL-1β, IL-6, CXCL-1, and CXCL-10 was as follows in the LPS group, WY14643+LPS group, and 3-MA+WY14643+LPS group: TNFα (4.327±0.478, 1.218±0.424, and 3.901±0.447, P < 0.05), IL-1β (4.277±0.407, 1.418±0.424, and 3.029±0.192, P < 0.01), IL-6 (4.175±0.549, 1.373±0.499, and 4.031±0.475, P < 0.05), CXCL-1 (8.199±1.149, 2.024±0.547, and 5.973±0.843, P < 0.05), and CXCL-10 (1.208±0.148, 0.206±0.069, and 0.798±0.170, P < 0.05). Conclusion: PPARα can promote cell autophagy and inhibit inflammatory response and may become a new therapeutic target for clinical prevention and treatment of inflammatory disease.

Comprehensive analysis of proton range uncertainties related to stopping-power-ratio estimation using dual-energy CT imaging

The dual-energy CT-based (DECT) approach holds promise in reducing the overall uncertainty in proton stopping-power-ratio (SPR) estimation as compared to the conventional stoichiometric calibration approach. The objective of this study was to analyze the factors contributing to uncertainty in SPR estimation using the DECT-based approach and to derive a comprehensive estimate of the range uncertainty associated with SPR estimation in treatment planning. Two state-of-the-art DECT-based methods were selected and implemented on a Siemens SOMATOM Force DECT scanner. The uncertainties were first divided into five independent categories. The uncertainty associated with each category was estimated for lung, soft and bone tissues separately. A single composite uncertainty estimate was eventually determined for three tumor sites (lung, prostate and head-and-neck) by weighting the relative proportion of each tissue group for that specific site. The uncertainties associated with the two selected DECT methods were found to be similar, therefore the following results applied to both methods. The overall uncertainty (1σ) in SPR estimation with the DECT-based approach was estimated to be 3.8%, 1.2% and 2.0% for lung, soft and bone tissues, respectively. The dominant factor contributing to uncertainty in the DECT approach was the imaging uncertainties, followed by the DECT modeling uncertainties. Our study showed that the DECT approach can reduce the overall range uncertainty to approximately 2.2% (2σ) in clinical scenarios, in contrast to the previously reported 1%.

[Effect of menopausal status on onset of impaired fasting glucose and type 2 diabetes mellitus]

Objective: To investigate the relationship between menopausal status at different FPG levels and the risk of new onset of impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM). Methods: Female subjects were selected from the females who joined in the epidemiological survey between May and September in 2009 in six counties of Guanlin Village and Xushe Village in Yixing City in Jiangsu Province by cluster sampling method. Subjects with diabetes at baseline or pre-menopause with age above 65 years old or surgical menopause were excluded. Finally there were 2 084 eligible subjects included in this study. According to FPG at baseline, subjects were categorized into two groups as normal FPG group (FPG<5.6 mmol/L) and IFG group (5.6≤FPG≤6.9 mmol/L). Follow-up study was conducted from May in 2014 to January in 2016. Cox regression model was used to investigate the association between menopausal factors and IFG and T2DM among groups based on FPG. Results: The average age of subjects at baseline was 58.08 (51.74-65.82) years old, and the number of post-menopausal women was 1 631 (78.3%). The number of subjects in normal FPG group was 1 569 (75.3%), and in IFG group was 515 (24.7%). There were 104 subjects with new onset T2DM among which 34 subjects from normal FPG group and 70 subjects from IFG group. And there were 199 subjects with new onset IFG in normal FPG group. Among subjects with normal FPG, the incidence density of IFG in post-menopausal women (2 752/100 000 person-years) was statistically higher than that in premenopausal women (1 670/100 000 person-years) (P<0.001). After age and BMI adjusted, post-menopausal women had a higher risk of having IFG in normal FPG subjects with hazard ratio (HR) at 2.60 (P<0.001). Among subjects with normal FPG, the risk of new onset IFG decreased in post-menopausal women with menopause age increasing after age and BMI adjusted, with HR at 0.96 (P=0.046). No statistical association was found between menopausal factors and risk of T2DM either in the overall subjects or in the subgroups(P>0.05). Conclusion: Menopause can increase the risk of IFG incidence in subjects with normal FPG. The incidence of IFG decreases with the menopause age increasing.

Spin-polarized charge trapping cell based on a topological insulator quantum dot

We demonstrate theoretically that a topological insulator quantum dot can be formed via double topological insulator constrictions (TICs), and can be used as a charge and/or spin carrier trap memory element.

The motility of esophageal sphincters during liquid and solid bolus swallows: a multicenter normative value study of high-resolution manometry in China

BACKGROUND

It is gradually accepted that solid bolus swallow needs to be added to the procedure of manometry. The motility differences in the upper esophageal sphincter (UES) and lower esophageal sphincter (LES) were not well described. Sierra Scientific Instruments solid-state high-resolution manometry (HRM) system, the most popular HRM system in China, lacks the Chinese normative values for both liquid and solid bolus swallow parameters.

METHODS

The esophageal HRM data of 88 healthy volunteers were analyzed. The parameters of both sphincters in resting stage were summarized and those during solid and liquid swallows were compared.

KEY RESULTS

Normative HRM values of sphincter parameters in solid and liquid bolus swallows in China were established. The UES residual pressure of solid bolus swallows was lower than that of liquid bolus (0.3±5.5 mm Hg vs 4.8±5.9 mm Hg, P=.000). The time parameters of UES relaxation between two types of bolus swallows were similar. In solid bolus swallows, the intrabolus pressure (IBP) (13.8±5.1 mm Hg vs 10.9±5.7 mm Hg, P=.000) and LES relaxation time (11.0±2.1 seconds vs 8.7±1.3 seconds, P=.000) were higher. The 4-second integrated relaxation pressure between both bolus swallows was similar.

CONCLUSIONS & INFERENCES

The function of the UES and LES between solid and liquid bolus swallows is different. Chinese HRM parameters are different from the Chicago Classification (http://www.chictr.org.cn, Number ChiCTR-EOC-15007147).

Effect of CaF2 Content on Rate of Fluoride Release from Filled Resins

Information on the time-dependent release of fluoride from filled resins containing fluoride particles as a function of particle content and solution pH is limited. This study characterized the fluoride ion release from filled resins containing CaF2 particles as a function of filler content and pH. Urethane dimethacrylate and triethylene glycol dimethacrylate resins were used to make filled-resin disks containing 9.09, 23.08, or 33.33 mass% CaF2 filler. Fluoride ion release for the 9.09 mass% concentration was independent of pH. Increasing the filler content from 9.09 to 33.33 mass% increased the fluoride release rate in pH 4.0 buffer solution, because of greater surface degradation. Fluoride ion release from disks stored in pH 6.0 buffer solutions occurred mainly by diffusion from disk surfaces, while fluoride release from disks in pH 4.0 buffers was controlled by diffusion from disk surfaces and degeneration of the resin matrix, which exposed more CaF2 particle surface area.

Adenylate cyclase 3: a new target for anti-obesity drug development

Obesity has become epidemic worldwide, and abdominal obesity has a negative impact on health. Current treatment options on obesity, however, still remain limited. It is then of importance to find a new target for anti-obesity drug development based upon recent molecular studies in obesity. Adenylate cyclase 3 (ADCY3) is the third member of adenylyl cyclase family and catalyses the synthesis of cAMP from ATP. Genetic studies with candidate gene and genome-wide association study approaches have demonstrated that ADCY3 genetic polymorphisms are associated with obesity in European and Chinese populations. Epigenetic studies have indicated that increased DNA methylation levels in the ADCY3 gene are involved in the pathogenesis of obesity. Furthermore, biological analyses with animal models have implicated that ADCY3 dysfunction resulted in increased body weight and fat mass, while reduction of body weight is partially explained by ADCY3 activation. In this review, we describe genomic and biological features of ADCY3, summarize genetic and epigenetic association studies of the ADCY3 gene with obesity and discuss dysfunction and activation of ADCY3. Based upon all data, we suggest that ADCY3 is a new target for anti-obesity drug development. Further investigation on the effectiveness of ADCY3 activator and its delivery approach to treat abdominal obesity has been taken into our consideration.

An Injured Psittacosaurus (Dinosauria: Ceratopsia) From the Yixian Formation (Liaoning, China): Implications for Psittacosaurus Biology

We describe a Psittacosaurus specimen from the Lujiatun beds of the Yixian Formation in Liaoning, China with an abnormality on its left fibula. Although a large number of Psittacosaurus specimens are known, only a single example of a pathologic Psittacosaurus has been previously noted. The specific pathology in the current specimen is believed to be a healed fibular fracture as assessed through a combination of gross morphology, microcomputed tomography (microCT), and histology data. The fracture can be identified using microCT, but the degree of remodeling and the stage of fracture repair are best determined histologically. The fracture callus is made up of radially oriented spokes of woven bone in a cartilage matrix and the original cortical bone prior to the fracture has been largely eroded. A transverse histologic section taken at the level of the fracture shows the displacement of the proximal and distal parts of the fibula. The Psittacosaurus appears to have survived the break considering the deposition of circumferential non-pathologic bone at the periosteal surface outside of the callus. The combination of gross morphological description, microCT data, and histologic data allowed for a full diagnosis of the abnormality. While some previous authors have preferred gross morphological description above other methods for assessing paleopathologies, it is evident based on this specimen that an amalgam of techniques provides greater clarity to paleopathology diagnoses. Although this Psittacosaurus lived in an environment with many predators, it was able to survive with a fracture on its hindlimb, which undoubtedly would have impacted its locomotion. Anat Rec, 299:897-906, 2016. © 2016 Wiley Periodicals, Inc.

Dendritic cells revisited in human allergic rhinitis and asthma

The role of dendritic cells (DCs) in airway allergy has been studied for 15 years; recent data has highlighted the cross talk with airway epithelial cells and environmental factors (allergens, virus) during the inception and exacerbation of allergic asthma. Although murine models have provided key information, it remains uncertain to what extent these basic mechanisms take place in human allergic disease, notably with regard to different clinical phenotypes. In the present review, we discuss new evidence regarding mechanisms of DC regulation in the mouse which could be important in human asthma. Finally, after discussing the effects of current therapies on DC biology, we focus on pathways that could represent targets for future therapies.

In situ dispersion of oil-based Ag nanocolloids by microdroplet coalescence and their applications in SERS detection

Monodispersity and size uniformity of the nanoparticles coated on film-like nanosensors are critical for detection efficiency.

Selective removal of copper with polystyrene–1,3-diaminourea chelating resin: synthesis and adsorption studies

In this study, green chloromethylated polystyrene bead–1,3-diaminourea (PS–DU) which was intended to adsorb copper ions was synthesized from chloromethylated polystyrene (PS-Cl) and 1,3-diaminourea (DU).

Autophagy protects chondrocytes from glucocorticoids-induced apoptosis via ROS/Akt/FOXO3 signaling

OBJECTIVE

Glucocorticoids (GCs) have been widely used in the management of osteoarthritis (OA) and rheumatoid arthritis (RA). Nevertheless, there has been some concern about their ability of increasing reactive oxygen species (ROS) in the cartilage. Forkhead-box class O (FOXO) transcription factors have been proved to have a protective role in chondrocytes through regulation of autophagy and defending oxidative stress. The objective of this study was to investigate the role of FOXO3 in Dex-induce up-regulation of ROS.

DESIGN

Healthy cartilages debris from six patients were used for chondrocytes culture. After the treatment of dexamethasone (Dex), the ROS levels, autophagic flux, the expression of FOXO3 in chondrocytes were measured. RNA interference technique was also used to determine the role of FOXO3 in Dex-induced autophagy. The metabolism of the extra-cellular matrix was also investigated.

THE RESULTS

Dex increased intracellular ROS level, the expression of Akt, FOXO3 as well as autophagy flux in human chondrocytes. The expression of aggrecanases also increased after the treatment of Dex. Catalase, the ROS scavenger, suppressed Dex-induced up-regulation of autophagy flux and expression of aggrecanases and Akt. MK-2206 and LY294002, the PI3K/Akt inhibitors, repressed Dex-induced up-regulation of FOXO3. Silencing FOXO3 resulted in down-regulation of Dex-induced autophagy. Moreover, knockdown of FOXO3 increased Dex-induced apoptosis as well as ROS levels in chondrocytes. In addition, up-regulation of autophagy by Rapamycin resulted in decreasing ROS level in chondrocytes.

CONCLUSION

Dex could advance the degenerative process in cartilage. Autophagy was induced in response to Dex-induced up-regulation of ROS via ROS/Akt/FOXO3 signal pathway.

Epidemiological transition and distribution of stroke incidence in Tianjin, China, 1988-2010

OBJECTIVES

To examine the trends in epidemiological transition of stroke over the last two decades in Tianjin, and investigate the subtypes of stroke.

STUDY DESIGN

A population-based epidemiological study using data from the Stroke Incidence Surveillance System of the Tianjin Centres for Disease Control and Prevention from 1988 to 2010.

METHODS

Almost 500,000 cases were analysed to examine changes in the incidence of stroke between 1988 and 2010 by age, sex, subtype, year and urban/rural status.

RESULTS

The incidence of stroke amongst males increased from 136.8/100,000 in 1988 to 387.0/100,000 in 2010, and the incidence amongst females increased from 65.9/100,000 in 1988 to 249.7/100,000 in 2010. Over the study period, the proportion of haemorrhagic strokes decreased and the proportion of ischaemic strokes increased sharply in both men and woman; the differences were significant.

CONCLUSION

The distribution of stroke subtypes changed dramatically over the study period. Changes in trend and subtypes of stroke have raised new challenges and there is a need for adjustment for stroke prevention in Tianjin.

Genome-wide differential expression of synaptic long noncoding RNAs in autism spectrum disorder

A genome-wide differential expression of long noncoding RNAs (lncRNAs) was identified in blood specimens of autism spectrum disorder (ASD). A total of 3929 lncRNAs were found to be differentially expressed in ASD peripheral leukocytes, including 2407 that were upregulated and 1522 that were downregulated. Simultaneously, 2591 messenger RNAs (mRNAs), including 1789 upregulated and 821 downregulated, were also identified in ASD leukocytes. Functional pathway analysis of these lncRNAs revealed neurological pathways of the synaptic vesicle cycling, long-term depression and long-term potentiation to be primarily involved. Thirteen synaptic lncRNAs, including nine upregulated and four downregulated, and 19 synaptic mRNAs, including 12 upregulated and seven downregulated, were identified as being differentially expressed in ASD. Our identification of differential expression of synaptic lncRNAs and mRNAs suggested that synaptic vesicle transportation and cycling are important for the delivery of synaptosomal protein(s) between presynaptic and postsynaptic membranes in ASD. Finding of 19 lncRNAs, which are the antisense, bi-directional and intergenic, of HOX genes may lead us to investigate the role of HOX genes involved in the development of ASD. Discovery of the lncRNAs of SHANK2-AS and BDNF-AS, the natural antisense of genes SHANK2 and BDNF, respectively, indicates that in addition to gene mutations, deregulation of lncRNAs on ASD-causing gene loci presents a new approach for exploring possible epigenetic mechanisms underlying ASD. Our study also opened a new avenue for exploring the use of lncRNA(s) as biomarker(s) for the early detection of ASD.

Importance of the Bulk Viscosity of QCD in Ultrarelativistic Heavy-Ion Collisions

We investigate the consequences of a nonzero bulk viscosity coefficient on the transverse momentum spectra, azimuthal momentum anisotropy, and multiplicity of charged hadrons produced in heavy ion collisions at LHC energies. The agreement between a realistic 3D hybrid simulation and the experimentally measured data considerably improves with the addition of a bulk viscosity coefficient for strongly interacting matter. This paves the way for an eventual quantitative determination of several QCD transport coefficients from the experimental heavy ion and hadron-nucleus collision programs.

Upregulation of long noncoding RNA ZEB1-AS1 promotes tumor metastasis and predicts poor prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. Despite progress in diagnostics and treatment of HCC, its prognosis remains poor. Emerging studies showed that long noncoding RNAs (lncRNAs) have crucial regulatory roles in cancer biology. In the current study, differentially expressed lncRNAs between HCC and paired non-tumor tissues were identified using microarrays. The effects of a specific differentially expressed lncRNA (termed ZEB1-AS1) on tumor progression were investigated in vitro and in vivo. We found that ZEB1-AS1 is frequently upregulated in HCC samples, especially in metastatic tumor tissues. DNA methylation analysis shows a tumor-specific ZEB1-AS1 promoter hypomethylation. Aberrant methylation is tightly correlated with overexpression of ZEB1-AS1 in HCC. Patients with ZEB1-AS1 hypomethylation or with high ZEB1-AS1 expression have poor recurrence-free survival. Functionally, ZEB1-AS1 promotes tumor growth and metastasis, acts as an oncogene in HCC. The ZEB1-AS1 gene is located in physical contiguity with ZEB1 and positively regulates the ZEB1 expression. ZEB1 inhibition partially abrogates ZEB1-AS1-induced epithelial to mesenchymal transition (EMT) and cancer metastasis. Our results provide novel insights into the function of lncRNA-driven hepatocarcinogenesis, highlight the important role of ZEB1-AS1 and ZEB1 in HCC progression, and indicate that ZEB1-AS1 may be served as a valuable prognostic biomarker for HCC.

Interleukin-1β increases Angptl4 (FIAF) expression via the JNK signaling pathway in osteoblastic MC3T3-E1 cells

Angiopoietin-like protein 4 (Angptl4), also known as fasting-induced adiopogenic factor (FIAF), has recently been reported to influence bone metabolism. However, there have been few studies on regulatory factors other than hypoxia for Angptl4 in bone, and particularly in osteoblasts. Expression of interleukin-1β (IL-1β), a proinflammatory cytokine, is increased in serum or bone microenvironments in inflammatory bone diseases or estrogen deficient-conditions. The present study was conducted to determine whether Angptl4 expression in osteoblasts is affected by IL-1β and investigate its involvement in MAP kinase signaling pathways. Angptl4 RNA levels were increased by IL-1β treatment in murine MC3T3-E1 osteoblastic cells. Western blotting and immunofluorescent staining showed a corresponding increase in Angptl4 protein. IL-1β treatment of osteoblasts induced phosphorylation of mitogen-activated protein kinases (MAPKs) including extracellular regulated kinases (ERKs), p38, and c-Jun N-terminal kinase (JNK). Furthermore, SP600125, an inhibitor of JNK, significantly blocked the upregulation of Angptl4 by IL-1β. In contrast, treatment with an inhibitor of p38 MAP kinase (SB203580) or an ERK inhibitor (PD98059) produced responses similar to those seen with the DMSO control. Taken together, these results suggest that IL-1β increases Angptl4 expression through a mechanism dependent on the JNK-MAPK signaling pathway in MC3T3-E1 cells.

Regular aspirin use and stomach cancer risk in China

OBJECTIVE

Epidemiological studies on aspirin and stomach cancer have been inconclusive. The purpose of our study was to investigate the association between aspirin and stomach cancer in China.

METHOD

A 1:2 matched case-control study was conducted in four large medical centers. A self-designed questionnaire was used to collect information. Unconditional logistic regression was used to compute crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs).

RESULT

Our study indicated that risk of stomach cancer was greatly reduced for regular aspirin user (OR = 0.62; 95% CI 0.42-0.80). Specifically, dosage and tablet-years of use were associated with lower risk (OR = 0.54; 95% CI 0.29-0.84 for ≥7 tabs/week; OR = 0.47; 95% CI 0.32-0.81 for ≥10 tablet years, respectively). Furthermore, the finding was strengthened by stratified studies of gender, smoking status, body mass index (BMI) and helicobacter pylori.

CONCLUSION

Our study confirmed that regular aspirin use is a protective factor to stomach cancer.

Impaired ICOSL in human myeloid dendritic cells promotes Th2 responses in patients with allergic rhinitis and asthma

BACKGROUND

Myeloid dendritic cells (mDCs) and costimulatory molecules such as ICOSL/B7H2 play a pivotal role in murine experimental asthma, while little is known in human allergic disease. The aim of this study was to characterize the phenotype and ICOSL expression of mDCs from allergic rhinitis patients (AR) and their functional correlates on mDC regulation of T cell responses.

METHODS

Human blood myeloid, CD1c(+) DCs were isolated from AR or healthy controls. Expression of costimulatory molecules inducible costimulatory ligand (ICOSL) and programmed death ligand 1 (PD-L1) was analysed in blood mDCs by flow cytometry and in nasal tissue biopsies by dual immunostaining. Blood mDCs were cocultured with (allogeneic) CD4(+) T cells before immunoassays for cytokine responses.

RESULTS

mDCs from AR patients expressed a lower level of ICOSL, in both blood and nasal tissue. mDCs from AR were constitutively primed to induce Th2 cytokines and TNF in allogeneic CD4(+) T cells, while no difference was observed for IFN-γ or IL-10. Production of IL-10 and IL-12 did not differ between AR and control mDCs. Blockade of ICOSL in control DCs up-regulated IL-13 but not IFN-γ in cocultures with T cells, while PD-L1 blockade up-regulated both IL-13 and IFN-γ.

CONCLUSIONS

Our data show that mDCs from patients with AR display impaired expression of ICOSL, and this defect licenses mDCs to promote aberrant IL-13- and IL-5-producing Th2 cell responses.

Plasma FGF23 levels and heart rate variability in patients with stage 5 CKD

Fibroblast growth factor 23(FGF23) is a bone-derived hormone which regulates mineral homeostasis but may also have a role in cardiovascular disease. Here, we found that higher plasma FGF23 was independently associated with decreased heart rate variability in stage 5 CKD patients and parathyroidectomy may reverse these abnormal indicators.

INTRODUCTION

Lower heart rate variability (HRV) in patients with chronic kidney disease (CKD) compared with healthy controls is associated with increased risk of cardiovascular disease (CVD). Higher levels of plasma FGF23 also predict higher risk of CVD. Here, we aimed to evaluate the relationship between plasma FGF23 levels and HRV in patients with stage 5 CKD and to investigate longitudinal changes of them together with the correlation between their changes in two severe secondary hyperparathyroidism (SHPT) subgroups with successful parathyroidectomy (PTX) and persistent SHPT.

METHODS

This cross-sectional study included 100 stage 5 CKD patients, 78 controls, and a prospective study in two PTX subgroups classified as successful PTX (n = 24) and persistent SHPT (n = 4) follow-up. Blood examination and 24-h Holter monitoring for HRV were measured.

RESULTS

Most HRV indices were lower in stage 5 CKD patients than in healthy controls, and plasma FGF23 levels were higher. In multivariate stepwise regression models, levels of plasma FGF23 and serum parathyroid hormone (PTH) were correlated with HRV. The successful PTX subgroup had significant improvements over baseline in HRV indices. Persistent SHPT subgroup had numerically similar changes in HRV indices. However, plasma FGF23 levels decreased in both subgroups.

CONCLUSIONS

Plasma FGF23 levels were higher in CKD patients than in controls, much higher in patients with severe SHPT. FGF23 was independently associated with decreased HRV in stage 5 CKD. Successful PTX may reverse these abnormal indicators and contribute to decreases in the risk of cardiovascular disease.

Oxidative status in the macula densa modulates tubuloglomerular feedback responsiveness in angiotensin II-induced hypertension

AIM

Tubuloglomerular feedback (TGF) is an important mechanism in control of signal nephron glomerular filtration rate. The oxidative stress in the macula densa, primarily determined by the interactions between nitric oxide (NO) and superoxide (O2-), is essential in maintaining the TGF responsiveness. However, few studies examining the interactions between and amount of NO and O2- generated by the macula densa during normal and hypertensive states.

METHODS

In this study, we used isolated perfused juxtaglomerular apparatus to directly measure the amount and also studied the interactions between NO and O2- in macula densa in both physiological and slow pressor Angiotensin II (Ang II)-induced hypertensive mice.

RESULTS

We found that slow pressor Ang II at a dose of 600 ng kg(-1) min(-1) for two weeks increased mean arterial pressure by 26.1 ± 5.7 mmHg. TGF response increased from 3.4 ± 0.2 μm in control to 5.2 ± 0.2 μm in hypertensive mice. We first measured O2- generation by the macula densa and found it was undetectable in control mice. However, O2- generation by the macula densa increased to 21.4 ± 2.5 unit min(-1) in Ang II-induced hypertensive mice. We then measured NO generation and found that NO generation by the macula densa was 138.5 ± 9.3 unit min(-1) in control mice. The NO was undetectable in the macula densa in hypertensive mice infused with Ang II.

CONCLUSIONS

Under physiological conditions, TGF response is mainly controlled by the NO generated in the macula densa; in Ang II induced hypertension, the TGF response is mainly controlled by the O2- generated by the macula densa.

Cohort Profile: Hong Kong Department of Health Elderly Health Service Cohort

The Department of Health Elderly Health Service Cohort in Hong Kong was set up to promote understanding of ageing in a global context, to exploit the role of Hong Kong as a sentinel for populations currently experiencing very rapid economic development, to provide a developed non-Western 'social laboratory' where empirically derived hypotheses can be tested and to leverage the different patterns of common chronic diseases between East and West to generate novel hypotheses about their determinants. The initial cohort enrolled from July 1998 to the end of December 2001 includes 66 820 people aged 65 years or older, forming about 9% of the population of this age. A comprehensive health assessment was made at enrollment and then repeated regularly on an ongoing basis. The health assessment included a comprehensive assessment of lifestyle, social circumstances, physical health and mental health, including an assessment of cognition and depressive symptoms. Health services use and deaths have been obtained by record linkage and confirmed, where necessary, by telephone interview. Currently, the data are not publicly available; we would welcome collaborations and research proposals.

Calreticulin promotes angiogenesis via activating nitric oxide signalling pathway in rheumatoid arthritis

Calreticulin (CRT) is a multi-functional endoplasmic reticulum protein implicated in the pathogenesis of rheumatoid arthritis (RA). The present study was undertaken to determine whether CRT was involved in angiogenesis via the activating nitric oxide (NO) signalling pathway. We explored the profile of CRT expression in RA (including serum, synovial fluid and synovial tissue). In order to investigate the role of CRT on angiogenesis, human umbilical vein endothelial cells (HUVECs) were isolated and cultured in this study for in-vitro experiments. Our results showed a significantly higher concentration of CRT in serum (5·4 ± 2·2 ng/ml) of RA patients compared to that of osteoarthritis (OA, 3·6 ± 0·9 ng/ml, P < 0·05) and healthy controls (HC, 3·7 ± 0·6 ng/ml, P < 0·05); and significantly higher CRT in synovial fluid (5·8 ± 1·2 ng/ml) of RA versus OA (3·7 ± 0·3 ng/ml, P < 0·05). High levels of CRT are expressed in synovial membrane localized predominantly to inflammatory cells and synovial perivascular areas in both the lining and sublining layers of RA synovial tissue (RAST). Increased nitric oxide (NO) production and phosphorylation level of endothelial nitric oxide synthase (eNOS) were measured in HUVECs following CRT stimulation, while the total eNOS expression was not significantly changed. Furthermore, CRT promoted the proliferation, migration and tube formation of HUVECs, which were significantly inhibited by a specific eNOS inhibitor. These findings suggested that CRT may be involved in angiogenesis events in RA through NO signalling pathways, which may provide a potential therapeutic target in the treatment of RA.