In this study, using a meta-analysis approach, we examined the correlation between serum levels of lysophosphastidic acid (LPA) and ovarian cancer (OC).
Relevant published studies were identified from multiple scientific literature databases by using a pre-determined electronic and manual search strategy. The search results were screened through a multi-step process to select high-quality case–control studies suitable for the present meta-analysis. Mean values and standardized mean differences (SMD) were calculated for plasma LPA levels. Two investigators independently extracted the data from the studies and performed data analysis using STATA software version 12.0 (Stata Corp, College Station, TX, USA).
Nineteen case–control studies met our selection criteria and contained a total of 980 OC patients, 872 benign controls and 668 healthy controls. Our meta-analysis results revealed that the plasma levels of LPA in OC patients were significantly higher than benign controls (SMD = 2.36, 95 % CI: 1.61–3.10, P <0.001) and healthy controls (SMD = 2.32, 95 % CI: 1.77–2.87, P <0.001). Subgroup analysis by ethnicity showed that the plasma LPA levels in OC patients were significantly higher than the benign controls only in Asian populations (SMD = 2.52, 95 % CI: 1.79–3.25, P <0.001). However, a comparison between healthy controls and OC patients revealed that, in both Asians and Caucasians, the OC patients displayed significantly higher plasma LPA levels compared to healthy controls (all P <0.05).
Our meta-analysis showed strong evidence that a significantly higher plasma LPA levels are present in OC patients, compared to benign controls and healthy controls, and plasma LPA levels may be used as a biomarker or target of OC.
Lysophosphatidic acid; Ovarian cancer; Bioactive phospholipid; Meta-analysis
There are limited data regarding the relationship between depression and mortality in hemodialysis patients.
Among 323 maintenance hemodialysis patients, depression symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale, with a score of ≥16 consistent with depression. Adjusted Cox proportional hazards models, with additional analyses incorporating antidepressant medication use, were used to evaluate the association between depression and mortality. Baseline CES-D scores were used for primary analyses, while secondary time dependent analyses incorporated subsequent CES-D results.
Mean age was 62.9 ± 16.5 years, 46% were women and 22% African American. Mean baseline CES-D score was 10.7 ± 8.3, and 83 (26%) participants had CES-D scores ≥16. During median (25th, 75th) follow-up of 25 (13, 43) months, 154 participants died. After adjusting for age, sex, race, primary cause of kidney failure, dialysis vintage and access, baseline depression was associated with an increased risk of all-cause mortality [HR (95% CI)=1.51 (1.06, 2.17)]. This attenuated with further adjustment for cardiovascular disease, smoking, Kt/V, serum albumin, log CRP and antidepressant use [HR=1.21 (0.82, 1.80)]. When evaluating time-dependent CES-D, depression remained associated with increased mortality risk in the fully adjusted model [HR=1.44 (1.00, 2.06)].
Greater symptoms of depression are associated with an increased risk of mortality in hemodialysis patients, particularly when accounting for the most proximate assessment. This relationship was attenuated with adjustment for comorbid conditions, suggesting a complex relationship between clinical characteristics and depression symptoms. Future studies should evaluate whether treatment for depression impacts mortality among HD patients.
All-cause mortality; antidepressant medication use; depression; hemodialysis
Bronchiectasis is prevalent in patients with COPD. The objective of this study was to assess the clinical characteristics and prognostic value of bronchiectasis in patients with COPD in China. Data from patients diagnosed with COPD at the Shanghai Pulmonary Hospital between January 2009 and December 2013 were retrospectively collected and analyzed. SPSS statistical software was used to analyze the data. Data from 896 patients with COPD were analyzed. Bronchiectasis was present in 311 patients. The isolation of pseudomonas aeruginosa (PA) from sputum was the variable most significantly associated with the presence of bronchiectasis in patients with COPD (hazard ratio (HR), 2.93; 95% confidence interval (CI), 1.35–6.37; P = 0.007). During follow-up (median of 21 months; interquartile range: 10-39 months), there were 75 deaths, of which 39 were in the bronchiectasis group. The presence of bronchiectasis (HR, 1.77; 95% CI, 1.02–3.08; P = 0.043) was associated with an increase in all-cause mortality in patients with COPD. These results suggest that bronchiectasis in patients with COPD was associated with the isolation of PA from the sputum. Bronchiectasis was an independent risk factor for all-cause mortality in patients with COPD.
Glomerular filtration rate (GFR) estimating equations using the combination of creatinine and cystatin C (eGFRcr-cys) are more accurate than equations using either alone (eGFRcr or eGFRcys). New guidelines suggest measuring cystatin C as a confirmatory test when eGFRcr may be inaccurate, but do not specify demographic or clinical conditions in which eGFRcys or eGFRcr-cys are more accurate than eGFRcr nor which estimate to use in such circumstances.
We compared the performance of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in 1119 subjects in the CKD-EPI cystatin C external validation dataset. Subgroups were defined by eGFRcr, age, sex, diabetes status and body mass index (BMI). The reference test was GFR measured using urinary or plasma clearance of exogenous filtration markers. Cystatin C and creatinine assays were traceable to primary reference materials. Accuracy was defined as the absolute difference in eGFR compared with mGFR.
The mean mGFR was 70 ± 41 (SD) mL/min/1.73 m2. eGFRcys was more accurate than eGFRcr at lower BMI and less accurate at higher BMI, especially at higher levels of eGFRcr. There were small differences in accuracy in people according to the diabetes status. eGFRcr-cys was as accurate or more accurate than eGFRcr or eGFRcys in these and all other subgroups.
eGFRcr-cys, but not eGFRcys, is more accurate than eGFRcr in most subgroups we studied, suggesting preferential use of eGFRcr-cys when serum cystatin C is measured as a confirmatory test to obtain more accurate eGFR. Further studies are necessary to evaluate diagnostic strategies for using eGFRcys and eGFRcr-cys.
CKD-EPI; cystatin C; diagnostic test accuracy; estimated GFR
Although cognitive impairment is common in hemodialysis patients, the etiology of and risk factors for its development remain unclear. Fibroblast growth factor 23 (FGF-23) levels are elevated in hemodialysis patients and are associated with increased mortality and left ventricular hypertrophy. Despite FGF-23 being found within the brain, there are no prior studies assessing whether FGF-23 levels are associated with cognitive performance. We measured FGF-23 in 263 prevalent hemodialysis patients in whom comprehensive neurocognitive testing was also performed. The cross-sectional association between patient characteristics and FGF-23 levels was assessed. Principal factor analysis was used to derive two factors from cognitive test scores, representing memory and executive function, which carried a mean of 0 and a standard deviation of 1. Multivariable linear regression adjusting for age, sex, education status, and other relevant covariates was used to explore the relationship between FGF-23 and each factor. Mean age was 63 years, 46% were women and 22% were African American. The median FGF-23 level was 3098 RU/mL. Younger age, lower prevalence of diabetes, longer dialysis vintage, and higher calcium and phosphorus were independently associated with higher FGF-23 levels. Higher FGF-23 was independently associated with a lower memory score (per doubling of FGF-23, β = −0.08 SD [95% confidence interval, CI: −0.16, −0.01]) and highest quartile vs. lowest quartile (β = −0.42 SD [−0.82, −0.02]). There was no definite association of FGF 23 with executive function when examined as a continuous variable (β = −0.03 SD [−0.10, 0.04]); however, there was a trend in the quartile analysis (β = −0.28 SD [−0.63, 0.07], P = 0.13, for 4th quartile vs. 1st quartile). FGF-23 was associated with worse performance on a composite memory score, including after adjustment for measures of mineral metabolism. High FGF-23 levels in hemodialysis patients may contribute to cognitive impairment.
Cognition; FGF-23; hemodialysis
A new lateral flow immunoassay (LFA) for the detection of cryptococcal antigen was developed.
We aimed to systematically review all relevant studies to evaluate the diagnostic accuracy of the cryptococcal antigen LFA on serum, CSF and urine specimens.
We searched public databases including PubMed, Web of Science, Elsevier Science Direct and Cochrane Library for the English-language literature published up to September 2014. We conducted meta-analyses of sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratios (DOR) and SROC of LFA in serum and CSF, respectively. The sensitivity of LFA in urine was also analyzed. Subgroup analyses were carried out to analyze the potential heterogeneity.
12 studies were included in this study. The pooled sensitivity and specificity values of LFA in serum were 97.6% (95% CI, 95.6% to 98.9%) and 98.1% (95% CI, 97.4% to 98.6%), respectively. The average PLR of LFA in serum was 43.787 (95% CI, 22.60–84.81) and the NLR was 0.03 (95% CI, 0.01–0.09). The pooled DOR was 2180.30 (95% CI, 868.92–5471.00) and the AUC was 0.9968. The pooled sensitivity and specificity values of LFA in CSF were 98.9% (95% CI, 97.9% to 99.5%) and 98.9% (95% CI, 98.0% to 99.5%), respectively. The average PLR of LFA in serum was 48.83 (95% CI, 21.59–110.40) and the NLR was 0.02 (95% CI, 0.01–0.04). The pooled DOR was 2931.10 (95% CI, 1149.20–7475.90) and the AUC was 0.9974. The pooled sensitivity value of LFA in urine was 85.0% (95% CI, 78.7% to 90.1%)
The study demonstrates a very high accuracy of LFA in serum and CSF for the diagnosis of cryptococcosis in patients at risk. LFA in urine can be a promising sample screening tool for early diagnosis of cryptococcosis.
Malignant melanoma’s (MM) incidence is rising faster than that of any other cancer in the US and the overall survival at 5 years is less than 10%. B cell associated protein 31 (BAP31) is overexpressed in most MMs and might be a promising target for immunotherapy of this disease.
Firstly, we investigated the expression profiles of human BAP31 (hBAP31) and mouse BAP31 (mBAP31) in human and mouse normal tissues, respectively. The expression level of hBAP31 in human MMs and mBAP31 in B16 melanoma cells was also analyzed. Then we constructed novel mBAP31 DNA vaccines and tested there ability to stimulate mBAP31-specific immune responses and antitumor immunity in B16 melanoma-bearing mice.
For the first time, we found that protein expression of hBAP31 were dramatically upregulated in human MMs when compared with human normal tissues. Predominant protein expression of mBAP31 was found in mouse B16 melanoma cells but not in mouse important organs. When mice were immunized with mBAP31 DNA vaccines, strong cellular response to mBAP31 was observed in the vaccinated mice. CTLs isolated from immunized mice could effectively kill mBAP31-positive target mouse B16 melanoma tumor cells in vitro and vaccination with mBAP31 DNA vaccines had potent anti-tumor activity in therapeutic model using B16 melanoma cells.
These are the first data supporting a vaccine targeting BAP31 that is capable of inducing effective immunity against BAP31-expressing MMs and will be applicable to human MMs and hBAP31 DNA vaccine warrants investigation in human clinical trials.
Electronic supplementary material
The online version of this article (doi:10.1186/s13046-015-0153-6) contains supplementary material, which is available to authorized users.
Malignant melanomas; Cancer immunotherapy; BAP31; DNA vaccine; LAMP
Land-use change has a crucial influence on soil respiration, which further affects soil nutrient availability and carbon stock. We monitored soil respiration rates under different land-use types (tea gardens with three production levels, adjacent woodland, and a vegetable field) in Eastern China at weekly intervals over a year using the dynamic closed chamber method. The relationship between soil respiration and environmental factors was also evaluated. The soil respiration rate exhibited a remarkable single peak that was highest in July/August and lowest in January. The annual cumulative respiration flux increased by 25.6% and 20.9% in the tea garden with high production (HP) and the vegetable field (VF), respectively, relative to woodland (WL). However, no significant differences were observed between tea gardens with medium production (MP), low production (LP), WL, and VF. Soil respiration rates were significantly and positively correlated with organic carbon, total nitrogen, and available phosphorous content. Each site displayed a significant exponential relationship between soil respiration and soil temperature measured at 5 cm depth, which explained 84–98% of the variation in soil respiration. The model with a combination of soil temperature and moisture was better at predicting the temporal variation of soil respiration rate than the single temperature model for all sites. Q10 was 2.40, 2.00, and 1.86–1.98 for VF, WL, and tea gardens, respectively, indicating that converting WL to VF increased and converting to tea gardens decreased the sensitivity of soil respiration to temperature. The equation of the multiple linear regression showed that identical factors, including soil organic carbon (SOC), soil water content (SWC), pH, and water soluble aluminum (WSAl), drove the changes in soil respiration and Q10 after conversion of land use. Temporal variations of soil respiration were mainly controlled by soil temperature, whereas spatial variations were influenced by SOC, SWC, pH, and WSAl.
Patients with diabetes in the aging population are at high risk of Alzheimer's disease (AD), and reduction of sirtuin 1 (SIRT1) activity occurs simultaneously with the accumulation of hyperphosphorylated tau in the AD-affected brain. It is not clear, however, whether SIRT1 is a suitable molecular target for the treatment of AD. Here, we employed a rat model of brain insulin resistance with intracerebroventricular injection of streptozotocin (ICV-STZ; 3 mg/kg, twice with an interval of 48 h). The ICV-STZ-treated rats were administrated with resveratrol (RSV; SIRT1-specific activator) or a vehicle via intraperitoneal injection for 8 weeks (30 mg/kg, once per day). In ICV-STZ-treated rats, the levels of phosphorylated tau and phosphorylated extracellular signal-regulated kinases 1 and 2 (ERK1/2) at the hippocampi were increased significantly, whereas SIRT1 activity was decreased without change of its expression level. The capacity of spatial memory was also significantly lower in ICV-STZ-treated rats compared with age-matched control. RSV, a specific activator of SIRT1, which reversed the ICV-STZ-induced decrease in SIRT1 activity, increases in ERK1/2 phosphorylation, tau phosphorylation, and impairment of cognitive capability in rats. In conclusion, SIRT1 protects hippocampus neurons from tau hyperphosphorylation and prevents cognitive impairment induced by ICV-STZ brain insulin resistance with decreased hippocampus ERK1/2 activity.
SIRT1; Tau phosphorylation; ERK1/2; Streptozotocin
Background: SMYD2 is a methyltransferase whose role in cancer is poorly understood and is lacking cell-active chemical tools.
Results: We describe LLY-507, a small molecule inhibitor of SMYD2.
Conclusion: LLY-507 is potent, selective, cell-active, and binds SMYD2 in a high resolution co-crystal.
Significance: LLY-507 is a first-in-class cell-potent chemical probe that will be valuable in dissecting SMYD2 biology.
SMYD2 is a lysine methyltransferase that catalyzes the monomethylation of several protein substrates including p53. SMYD2 is overexpressed in a significant percentage of esophageal squamous primary carcinomas, and that overexpression correlates with poor patient survival. However, the mechanism(s) by which SMYD2 promotes oncogenesis is not understood. A small molecule probe for SMYD2 would allow for the pharmacological dissection of this biology. In this report, we disclose LLY-507, a cell-active, potent small molecule inhibitor of SMYD2. LLY-507 is >100-fold selective for SMYD2 over a broad range of methyltransferase and non-methyltransferase targets. A 1.63-Å resolution crystal structure of SMYD2 in complex with LLY-507 shows the inhibitor binding in the substrate peptide binding pocket. LLY-507 is active in cells as measured by reduction of SMYD2-induced monomethylation of p53 Lys370 at submicromolar concentrations. We used LLY-507 to further test other potential roles of SMYD2. Mass spectrometry-based proteomics showed that cellular global histone methylation levels were not significantly affected by SMYD2 inhibition with LLY-507, and subcellular fractionation studies indicate that SMYD2 is primarily cytoplasmic, suggesting that SMYD2 targets a very small subset of histones at specific chromatin loci and/or non-histone substrates. Breast and liver cancers were identified through in silico data mining as tumor types that display amplification and/or overexpression of SMYD2. LLY-507 inhibited the proliferation of several esophageal, liver, and breast cancer cell lines in a dose-dependent manner. These findings suggest that LLY-507 serves as a valuable chemical probe to aid in the dissection of SMYD2 function in cancer and other biological processes.
cancer biology; crystal structure; enzyme inhibitor; epigenetics; protein methylation; SMYD2; chemical probe; methyltransferase
The purpose of this study was to evaluate the clinical benefits and safety of the long-term use of macrolides in patients with non-cystic fibrosis (non-CF) bronchiectasis.
Embase, Pubmed, the Cochrane Library and Web of Science databases were searched from inception up to March 2014. The primary outcome was the improvement of exacerbations of bronchiectasis. Secondary endpoints included changes of microbiology, lung function, quality of life, sputum volume, adverse events and macrolide resistance.
The literature search yielded 139 studies, ten of which containing 601 patients were included in this meta-analysis. Macrolides showed a statistically-significant improvement in reducing acute exacerbations per patient during follow-up treatment (RR = 0.55, 95% CI: 0.47, 0.64, P < 0.001), increasing the number of patients free from exacerbations (OR = 2.81, 95% CI: 1.85, 4.26, P < 0.001), and prolonging time to a first exacerbation (HR = 0.38, 95% CI: 0.28, 0.53, P < 0.001). Macrolides maintenance treatment was superior to control with respect to attenuating FEV1 decline (p = 0.02), improving sputum volume (p = 0.009) and SGRQ total scores (p = 0.02), but showed a higher risk of adverse events, especially diarrhea (OR = 5.36; 95% CI: 2.06, 13.98, P = 0.0006). Eradication of pathogens was improved in the macrolide group (OR = 1.76, 95% CI: 0.91, 3.41, P = 0.09), while pathogen resistance caused by macrolides dramatically increased (OR = 16.83, 95% CI: 7.26, 38.99, P < 0.001). The new appearance of a microbiologic profile or participant withdrawal due to adverse events showed no significant differences between the two groups.
In patients with non-CF bronchiectasis, macrolide maintenance treatment can effectively reduce frequency of exacerbations, attenuate lung function decline, decrease sputum volume, improve quality of life, but may be accompanied with increased adverse events (especially diarrhea) and pathogen resistance.
Electronic supplementary material
The online version of this article (doi:10.1186/s12879-015-0872-5) contains supplementary material, which is available to authorized users.
Shiraia bambusicola P. Henn. is a pathogenic fungus of bamboo, and its fruiting bodies are regarded as folk medicine. We determined and analyzed its complete mitochondrial DNA sequence (circular DNA molecule of 39,030 bp, G + C content of 25.19%). It contains the typical genes encoding proteins involved in electron transport and coupled oxidative phosphorylation (nad1-6 and nad4L, cob and cox1-3), one ATP synthase subunit (atp6), 4 hypothetical proteins, and two genes for large and small rRNAs (rnl and rns). There is a set of 32 tRNA genes comprising all 20 amino acids, and these genes are evenly distributed on the two strands. Phylogenetic analyses based on concatenated mitochondrial proteins indicated that S. bambusicola clustered with members of the order Pleosporales, which is in agreement with previous results. The gene arrangements of Dothideomycetes species contained three regions of gene orders partitioned in their mitochondrial genomes, including block 1 (nad6-atp6), block 2 (nad1-cox3) and block 3 (genes around rns). S. bambusicola displayed unique special features that differed from the other Pleosporales species, especially in the coding regions around rns (trnR-trnY). Moreover, a comparison of gene orders in mitochondrial genomes from Pezizomycotina revealed that although all encoded regions are located on the same strand in most Pezizomycotina mtDNAs, genes from Dothideomycetes species had different orientations, as well as diverse positions and colocalization of genes (such as cox3, cox1-cox2 and nad2–nad3); these distinctions were regarded as class-specific features. Interestingly, two incomplete copies of the atp6 gene were found on different strands of the mitogenomic DNA, a finding that has not been observed in the other analyzed fungal species. In our study, mitochondrial genomes from Dothideomycetes species were comprehensively analyzed for the first time, including many species that have not appeared in previous reports.
Photonic methods of radio-frequency waveform generation and processing can provide performance advantages and flexibility over electronic methods due to the ultrawide bandwidth offered by the optical carriers. However, bulk optics implementations suffer from the lack of integration and slow reconfiguration speed. Here we propose an architecture of integrated photonic radio-frequency generation and processing and implement it on a silicon chip fabricated in a semiconductor manufacturing foundry. Our device can generate programmable radio-frequency bursts or continuous waveforms with only the light source, electrical drives/controls and detectors being off-chip. It modulates an individual pulse in a radio-frequency burst within 4 ns, achieving a reconfiguration speed three orders of magnitude faster than thermal tuning. The on-chip optical delay elements offer an integrated approach to accurately manipulating individual radio-frequency waveform features without constraints set by the speed and timing jitter of electronics, and should find applications ranging from high-speed wireless to defence electronics.
Performing radio-frequency arbitrary waveform generation in the optical domain offers advantages over electronic-based methods but suffers from lack of integration and slow speed. Here, Wang et al. propose a fast-reconfigurable, radio-frequency arbitrary waveform generator fully integrated in a silicon chip.
Current guidelines recommend under 2g/day sodium intake in chronic kidney disease, but there are few studies relating sodium intake to long-term outcomes. Here we evaluated the association of mean baseline 24-hour urinary sodium excretion with kidney failure and a composite outcome of kidney failure or all-cause mortality using Cox regression in 840 participants enrolled in the Modification of Diet in Renal Disease Study. Mean 24-hour urinary sodium excretion was 3.46 g/day. Kidney failure developed in 617 and the composite outcome was reached in 723. In the primary analyses there was no association between 24-hour urine sodium and kidney failure [HR 0.99 (95% CI 0.91–1.08)] nor on the composite outcome [HR 1.01 (95% CI 0.93–1.09),] each per 1g/day higher urine sodium. In exploratory analyses there was a significant interaction of baseline proteinuria and sodium excretion with kidney failure. Using a 2-slope model, when urine sodium was under 3g/day, higher urine sodium was associated with increased risk of kidney failure in those with baseline proteinuria under 1g/day, and lower risk of kidney failure in those with baseline proteinuria of 1g/day or more. There was no association between urine sodium and kidney failure when urine sodium was 3g/day or more. Results were consistent using first baseline and time-dependent urine sodium. Thus, we noted no association of urine sodium with kidney failure. Results of the exploratory analyses need to be verified in additional studies and the mechanism explored.
24-h urinary sodium excretion; kidney failure; CKD
To investigate the effects of probucol combined with atorvastatin on the serum oxidation index and lipid levels in patients diagnosed with acute coronary syndrome (ACS).
We randomly assigned 126 ACS patients (77 males and 49 females) to the control group (atorvastatin 20 mg/day, n=62) or the treatment group (atorvastatin 20 mg/day and probucol 750 mg/day, n=64). All the patients were followed up for 12 weeks. As oxidization indices, we measured the serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), oxidized LDL (ox-LDL), and paraoxonase-1 (PON1) before and after treatment. We also monitored the adverse effects of the drugs during the treatment.
At baseline, there were no obvious differences (P>0.05) between the two groups (including age, gender, etc.). After 12 weeks of treatment, the ox-LDL levels in the treatment group were significantly lower while PON1 levels were significantly higher than those in the control group. There were no statistically significant difference between the two groups with respect to the side effects (P<0.05).
The combined use of atorvastatin and probucol in ACS patients could reduce ox-LDL expression and increase PON1 expression more effectively than use atorvastatin alone.
Probucol; atorvastatin; acute coronary syndrome (ACS); paraoxonase-1 (PON1); oxidized low-density lipoprotein (ox-LDL)
The expression of CD133 decreases with differentiation of tumor cell, indicating that CD133 is a specific marker for isolation and identification of CSCs. In the present study the effect of Ursolic acid chalcone (UAC) on CD133+ hepatocellular carcinoma cell (HCC CSCs) differentiation, their self-renewal, tumorigenic capacity and sensitivity to chemotherapeutic drugs was studied. The results demonstrated that UAC inhibits the expression of CD133+ in a dose and time-dependent manner in PLC/PRF/5 and Huh7 HCC cells. The inhibition was significant at 50 μM and on day 8. The percentage of CD133+ cells decreased from an initial 59.3% in PLC/PRF/5 to 37.1% and 78.2% in Huh7 to 59.2% on treatment with UAC. There was inhibition of Oct4, Tert, Bmi1, β-catenin, ABCG2, and tumor sphere-related gene Ep300. In addition it also decreased number of CK19-positive cells and increased number of CK8/18-positive cells. UAC treatment caused a decrease in self-renewal capability and increase in sensitivity to doxorubicin and vincristine drugs in CD133+ HCC CSCs. Therefore, UAC can be a potent therapeutic agent to target differentiation of CSC in HCC.
Self-renewal; therapeutic agent; hepatocellular carcinoma; cell differentiation
The present study established a model of RyR2 knockdown cardiomyocytes and elucidated the role of RyR2 in aconitine-induced arrhythmia. Cardiomyocytes were obtained from hearts of neonatal Sprague–Dawlay rats. siRNAs were used to down-regulate RyR2 expression. Reduction of RyR2 expression was documented by RT-PCR, western blot, and immunofluorescence. Ca2+ signals were investigated by measuring the relative intracellular Ca2+ concentration, spontaneous Ca2+ oscillations, caffeine-induced Ca2+ release, and L-type Ca2+ currents. In normal cardiomyocytes, steady and periodic spontaneous Ca2+ oscillations were observed, and the baseline [Ca2+]i remained at the low level. Exposure to 3 μM aconitine increased the frequency and decreased the amplitude of Ca2+ oscillations; the baseline [Ca2+]i and the level of caffeine-induced Ca2+ release were increased but the L-type Ca2+ currents were inhibited after application of 3 μM aconitine for 5 min. In RyR2 knockdown cardiomyocytes, the steady and periodic spontaneous Ca2+ oscillations almost disappeared, but were re-induced by aconitine without affecting the baseline [Ca2+]i level; the level of caffeine-induced Ca2+ release was increased but L-type Ca2+ currents were inhibited. Alterations of RyR2 are important consequences of aconitine-stimulation and activation of RyR2 appear to have a direct relationship with aconitine-induced arrhythmias. The present study demonstrates a potential method for preventing aconitine-induced arrhythmias by inhibiting Ca2+ leakage through the sarcoplasmic reticulum RyR2 channel.
RyR2; Knockdown; Aconitine; Arrhythmia; Excitation–contraction coupling
AIM: To investigate the expression of zinc finger protein 139 (ZNF139) in gastric cancer (GC), and to analyze its clinical significance.
METHODS: A total of 108 patients who were diagnosed with GC and underwent surgery between January 2005 and March 2007 were enrolled in this study. Gastric tumor specimens and paired tumor-adjacent tissues were collected and paraffin-embedded, and the clinicopathologic characteristics and prognosis were recorded. The expression of ZNF139, Bcl-2, Bax, and caspase-3 were determined by immunohistochemistry, and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling. SPSS 13.0 software was used for data processing and analyses, and signiﬁcance was determined at P < 0.05.
RESULTS: The expression of ZNF139 was stronger in tumors than in tumor-adjacent tissues (66.67% vs 44.44%; P < 0.01). Overexpression of ZNF139 correlated with tumor differentiation, invasion depth, clinical stage, lymphatic metastasis, and blood vessel invasion (all Ps < 0.05). Patients with overexpression of ZNF139 had a poorer prognosis (P < 0.01), and overexpression of ZNF139 was an independent factor for the prognosis of GC patients by a Cox survival analysis (P = 0.02). A negative relationship between ZNF139 and the apoptosis index was observed (r = -0.686; P < 0.01). The expression of Bcl-2 in GC was stronger than in tumor-adjacent tissues (66.67% vs 41.67%), whereas the expression levels of Bax and caspase-3 were lower in primary tumors (54.63% and 47.22%, respectively) than in tumor-adjacent tissues (73.15% and 73.15%, respectively) (all Ps < 0.05). The expression of ZNF139 negatively correlated with caspase-3 (r = -0.370; P < 0.01). The expressions of Bcl-2 and Bax were also negatively correlated (r = -0.231; P = 0.02). The expressions of caspase-3 and Bax protein were positively correlated (r = 0.217; P = 0.024).
CONCLUSION: ZNF139 is related to clinicopathologic characteristics and prognosis of GC. Furthermore, it is overexpressed and involved in apoptosis in GC tissues by regulating caspase-3.
Apoptosis; Clinicopathologic characteristics; Gastric cancer; Prognosis; Zinc finger protein 139
Angioedema (AE) is idiopathic in the majority of cases. We studied patients with AE for genetic variants of proteins involved with bradykinin generation and biodisposition.
One hundred sixty one patients with AE were recruited at a university hospital clinic. Patients were categorized according to the proposed pathogenesis of AE: low C1 inhibitor (C1-INH) and C4 levels, autoimmune disease, cancer, angiotensin-converting enzyme (ACE) inhibitor-induced, nonsteroidal antiinflammatory drug (NSAID)-induced, or idiopathic. In addition, each patient had a blood sample analyzed for a complement profile and enzymes (C1-INH and C4). Fifty-two of the patients were tested for genetic variants in factor XII, plasminogen-activator inhibitor-1 (PAI-1), ACE, and aminopeptidase P (APP).
The cause of angioedema was identified in 59/161 (37%) of the cases: 3 (2%) patients had a low plasma C1-INH and C4; 20 (12%) were ACE inhibitor-induced; 12 (7%) were associated with autoimmune disorders; 7 (4%) were associated with malignancy; and 17 (11%) were associated with NSAIDs. In the remaining 102 (63%) patients the cause of angioedema was idiopathic. Of 52 patients with genetic analysis, 13 (25%) had a genetic variant in APP, 10 (19%) in ACE, 13 (25%) in PAI-1, and 0 in Factor XII.
In addition to related diseases and medications causing AE, certain genetic variants encoding proteins involved in bradykinin generation and/or catabolism pathways may be involved in the pathogenesis of AE.
Angioedema; Plasminogen-activator inhibitor-1; Aminopeptidase P; Angiotensin-converting enzyme; Factor XII
The allosteric regulation of substrate channeling in tryptophan synthase involves ligand-mediated allosteric signaling that switches the α- and β-subunits between open (low activity) and closed (high activity) conformations. This switching prevents the escape of the common intermediate, indole, and synchronizes the α- and β-catalytic cycles. 19F NMR studies of bound α-site substrate analogues, N-(4’-trifluoromethoxybenzoyl)-2-aminoethyl phosphate (F6) and N-(4’-trifluoromethoxybenzenesulfonyl)-2-aminoethyl phosphate (F9), were found to be sensitive NMR probes of β-subunit conformation. Both the internal and external aldimine F6 complexes gave a single bound peak at the same chemical shift, while α-aminoacrylate and quinonoid F6 complexes all gave a different bound peak shifted by +1.07 ppm. The F9 complexes exhibited similar behavior, but with a corresponding shift of -0.12 ppm. X-ray crystal structures show the F6 and F9 CF3 groups located at the α-β subunit interface and report changes in both the ligand conformation and the surrounding protein microenvironment. Ab initio computational modeling suggests that the change in 19F chemical shift results primarily from changes in the α-site ligand conformation. Structures of α-aminoacrylate F6 and F9 complexes and quinonoid F6 and F9 complexes show the α- and β-subunits have closed conformations wherein access of ligands into the α- and β-sites from solution is blocked. Internal and external aldimine structures show the α- and β-subunits with closed and open global conformations, respectively. These results establish that β-subunits exist in two global conformation states, designated open, where the β-sites are freely accessible to substrates, and closed, where the β-site portal into solution is blocked. Switching between these conformations is critically important for the αβ-catalytic cycle.
Previously we reported that the expression of promyelocytic leukemia (PML)-retinoic acid receptor alpha (RARα) fusion gene, which is caused by specific translocation (15;17) in acute promyelocytic leukemia, can enhance constitutive autophagic activity in leukemic and nonleukemic cells, and PML overexpression can sequestrate part of microtubule-associated protein light chain 3 (LC3) protein in PML nuclear bodies, suggesting that LC3 protein also distributes into nuclei although it is currently thought to function primarily in the cytoplasm, the site of autophagosomal formation. However, its potential significance of nucleoplasmic localizations remains greatly elusive. Here we demonstrate that PML interacts with LC3 in a cell type-independent manner as assessed by Co-IP assay and co-localization observation. Overexpressed PML significantly coprecipitates with endogenous and nuclear LC3 protein. Furthermore, a fraction of endogenous PML protein is found to be co-localized with LC3 protein under steady state condition, which is further enhanced by IFNα induction, indicating that PML up-regulation potentiates this interaction. Additionally, DsRed-PML associates with EGFP-LC3 during telophase and G1 phase but not in metaphase and anaphase. Two potential LC3-interacting region (LIR) motifs in PML are required for interaction of PML with LC3 while this association is independent of autophagic activity. Finally, we show that interaction between PML and LC3 contributes to cell growth inhibition function of PML. Considering that PML is an important tumor suppressor, we propose that nuclear portion of LC3 protein may associate with PML to control cell growth for prevention and inhibition of cancer occurrence and development.
Continuous ambulatory peritoneal dialysis (CAPD) patients with diabetes are at increased risk of mortality and high peritoneal transporters appear to contribute to poor survival. However, little is known about the combined impacts of high peritoneal transporters and diabetes on mortality.
This was a prospective observational cohort study. 776 incident CAPD patients were enrolled. Unadjusted and adjusted Cox proportional regression models were used to evaluate the association and interaction of peritoneal transport and diabetic status with mortality
In the entire cohort, high peritoneal transport status was associated with an increased risk of all-cause mortality in unadjusted model [hazard ratio (HR) 2.35, 95% confidence interval (CI) 1.30 to 4.25, P = 0.01], but this association was not significant in multivariable model. There was an interaction between peritoneal membrane transport status and diabetes (P = 0.028). Subgroup analyses showed that compared to low and low average transporters, high transporters was associated with a higher risk of all-cause mortality (adjusted HR 1.78, 95% CI 1.07 to 4.70, P = 0.04) in CAPD patients without diabetes, but not in those with diabetes (adjusted HR 0.79, 95%CI 0.33 to 1.89, P = 0.59). Results were similar when transport status was assessed as a continuous variable.
The association between high peritoneal transport and all-cause mortality was likely to vary with diabetes status. High peritoneal transport was associated with an elevated risk of death among CAPD patients without diabetes, but not in those with diabetes.
Objective: To investigate the expression and clinical significance of annexin A7 in the differentiation and lymphatic metastasis of gastric cancer (GC). Methods: The clinical and pathological data were recorded for analysis. Immunohistochemical staining and Western blot were performed to analyze the expression of ANXA 7 in primary GC tissues. Logistic regression analyses were conducted to evaluate the associations between annexin A7 expression levels and differentiations of GC. Analyses of the ROC were conducted to determine the cut-off value of the ratio of pixel density of annexin A7 for predicting lymphatic metastasis of GC. Results: A total of 162 GC patients were enrolled in this study, and expression rate of annexin A7 was 65.4% in GC. The survival rate of patients with positive expression of annexin A7 was lower than that in patients with negative expression (P=0.000). The results of COX regression showed that the positive expression of annexin A7, submucosal confinement and pathological stage of GC were associated with poor clinical outcomes. The ratio of pixel density value of primary GC tissues with PN 1-3 lymphatic spread was significantly higher than those in tissues with PN 0 lymphatic spread (0.56±0.09 vs. 0.42±0.07, P < 0.05). ROC analysis showed a high area under the curve for the ratio of pixel density value of annexin A7 in primary GC tissues. At a cut-off level of > 0.505, the ratio of pixel density value of annexin A7 exhibited 76.7% sensitivity and 88.3% specificity for detecting lymphatic metastasis of GC. Conclusion: High annexin A7 expression is associated with poor differentiation in GC patients, and it may be a predictor for lymphatic metastasis of GC.
Annexin A7; gastric cancer; cancer differentiation; lymphatic metastasis; predictor
To investigate the correlation between the serum resistin level and carotid artery atherosclerosis in elderly Chinese males.
The study enrolled 235 elderly Chinese males [median age 76 (range 60–97) years] scheduled for ultrasound examination of carotid artery plaque and determination of carotid artery intima-media thickness (CIMT). They were divided into carotid atherosclerotic plaque (CAP) and carotid atherosclerotic plaque-free (CAP-free) groups according to the ultrasound results. Their clinical profiles were collected, and the serum resistin and other blood biochemistry levels were determined.
The CAP group was older and had a thicker mean CIMT than the CAP-free group. However, there was no difference in the serum resistin level between the groups. CIMT was positively correlated with age (r = 0.299, P < 0.001). The serum resistin level was not correlated with CIMT, even after controlling for age. Multiple linear regression analysis revealed that age (β = 0.001, P < 0.001) and body mass index (β = 0.002, P = 0.015) were significantly and positively correlated with the mean CIMT. Only age [odds ratio (OR): 1.159; 95% confidence interval (CI): 1.078–1.183, P < 0.001] was associated with the presence of carotid artery atherosclerotic plaque. The serum resistin level was not correlated with the mean CIMT or associated with the presence of carotid artery atherosclerotic plaque.
The results suggest that resistin might not be a risk factor for atherosclerosis in elderly Chinese males.
Resistin; Intima-media thickness; Atherosclerosis; The elderly
Regorafenib is an inhibitor of multiple protein kinases which exerts antitumor and antimetastatic activities in metastatic colorectal cancer (CRC). SH2 domain-containing phosphatase 1 (SHP-1) is reported to have tumor suppressive potential because it acts as a negative regulator of p-STAT3Tyr705 signaling. However, little is known about the mechanism regarding regorafenib affects SHP-1 tyrosine phosphatase activity and leads to apoptosis and tumor suppression in CRC. Here, we found that regorafenib triggered apoptotic cell death and significantly enhanced SHP-1 activity, which dramatically decreased the phosphorylated form of STAT3 at Tyr705 (p-STAT3Tyr705). Importantly, regorafenib augmented SHP-1 activity by direct disruption of the association between N-SH2 and catalytic PTP domain of SHP-1. Deletion of the N-SH2 domain (dN1) or point mutation (D61A) of SHP-1 blocked the effect of regorafenib-induced SHP-1 activity, growth inhibition and a decrease of p-STAT3Tyr705 expression, suggesting that regorafenib triggers a conformational change in SHP-1 by relieving its autoinhibition. In vivo assay showed that regorafenib significantly inhibited xenograft growth and decreased p-STAT3Tyr705 expression but induced higher SHP-1 activity. Collectively, regorafenib is a novel SHP-1 agonist exerts superior anti-tumor effects by enhancing SHP-1 activity that directly targets p-STAT3Tyr705. Small molecule-enhancement of SHP-1 activity may be a promising therapeutic approach for CRC treatment.
SHP-1; Regorafenib; Colorectal cancer; STAT3; Apoptosis