Insights into cognitive deficits caused by low-dose toxic heavy metal mixtures and their remediation through a postnatal enriched environment in rats

The heavy metals, namely lead (Pb), cadmium (Cd), and mercury (Hg), have been studied extensively in various independent studies. It has been seen that these metals are usually detected simultaneously in the human blood at low levels. However, it is unknown whether exposure to these heavy metal mixtures (MM) can induce neurological damages at these low levels. Therefore, we investigated the influence of the Pb, Cd, and Hg mixture on the nervous system in rats at exposure doses equivalent to those normally found in the human blood. After pregnant rats being exposed to MM via drinking water throughout the gestation and lactation, their offspring were followed-up till adulthood. MM caused cognitive deficits and impairments in a dose-dependent manner. Furthermore, MM disrupted dendritic spines, the structural basis of learning and memory, and induced changes in spine-related pathways. Meanwhile, we explored an early and safe way to remedy these impairments through a postnatal enriched environment. The enriched environment ameliorated MM-impaired cognitive function, synaptic plasticity, and spine-related pathways. This study demonstrated that low-dose co-exposure to Pb, Cd, and Hg can cause cognitive and synaptic plasticity deficits and timely intervention through the enriched environment has a certain corrective effect.

RyRs mediate lead-induced neurodegenerative disorders through calcium signaling pathways

Heavy metal lead (Pb) is widely distributed in the environment and can induce neurodegeneration. Accumulating evidence has shown that ryanodine receptors (RyRs) play vital roles in neurodegenerative brain. However, whether aberrant RyRs levels contribute to Pb-induced neurodegeneration has largely remained unknown. In the present study, we report the important role of elevated levels of RyRs in Pb-induced neurodegeneration. Pb was found to upregulate the levels of RyRs in the rat hippocampal tissues and rat pheochromocytoma (PC12) cells. Furthermore, exposure to Pb induced neurodegenerative cognitive impairment in rats, depressed the long-term potentiation (LTP) in the rat brain slices, increased the neuronal intracellular free calcium concentration ([Ca²⁺]i), inhibited the phosphorylation of Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) and cyclic adenosine 3',5'-monophosphate (cAMP) response element binding protein (CREB) as well as the expression of anti-apoptotic protein B-cell lymphoma 2 (Bcl2), and activated the phosphorylation of extracellular regulated protein kinases (Erk) protein both in vitro and in vivo. In addition, the knockdown of RyR3 in PC12 cells significantly decreased the [Ca²⁺]i levels, increased the CaMKIIα and CREB phosphorylation, decrease the phosphorylation of Erk, and elongated the cognitive function-related neurite outgrowth after exposure to Pb. Moreover, treatment with a RyRs agonist showed the involvement of RyRs in Pb-induced depression in LTP in the rat brain slices. In summary, we determined that Pb-mediated upregulation of RyRs led to neurodegeneration via high levels of free calcium, depression of the calcium-dependent CaMKIIα/CREB mnemonic signaling pathway, and activation of the calcium-dependent Erk/Bcl2 apoptotic signaling pathway. These findings on the impact of Pb on the levels of RyRs could further improve our understanding of Pb-induced neurotoxicity and provide a promising molecular target to antagonize Pb-induced neurodegenerative diseases.

Excessive daytime sleepiness with snoring or witnessed apnea is associated with handgrip strength: a population-based study

BACKGROUND

Sarcopenia is emerging as an important public health problem, and evidences have determined that poor sleep is associated with muscle strength, but the potential effects of excessive daytime sleepiness (EDS), snoring and witnessed apnea on handgrip strength have not been evaluated.

AIM

We aimed to examine the association between EDS, snoring, witnessed apnea and muscle strength in an adult population.

DESIGN

Cross-sectional study.

METHODS

This cross-sectional study comprised 19 434 adults. Handgrip strength was measured using a handheld digital dynamometer. EDS was assessed by Epworth Sleepiness Scale, snoring and witnessed apnea during sleep were reported through simple yes/no questions. Analysis of covariance was carried out to determine the association between EDS with snoring or witnessed apnea and muscle strength.

RESULTS

The means (95% confidence interval) for average handgrip strength/body weight (kg/kg) across symptoms categories were 0.396 (0.333-0.472), 0.393 (0.330-0.467), 0.396 (0.333-0.471) and 0.386 (0.325-0.460) (P < 0.0001), respectively. Similar results were observed with maximal handgrip strength/body weight (kg/kg).

CONCLUSIONS

Self-reported EDS accompanied with snoring or apnea is associated with lowest handgrip strength, independently of confounding factors. Whether improvement of EDS, snoring and apnea, can ameliorate age-associated decline in muscle strength warrants further studies.

[Expression changes of miRNA-29b-3p and miRNA-34c-3p in lung tissue of rats exposed to silica and A549 cells]

Objective: To investigate the role of microRNA-29b-3p (miRNA-29b-3p) and miRNA-34c-3p in the process of pulmonary fibrosis, we detected the expression levels of miRNA-29b-3p and miRNA-34c-3p in the lung tissue of rats exposed to silica and A549 cells. Methods: SPF male Wistar rats were randomly divided into 1, 7, 14, 21, 28 d control group and silica (SiO(2)) dusting group, with 6 rats in each group. One-time non-exposure method was used to infuse 1ml SiO(2) suspension. The rat SiO(2) dusting group was established in the liquid, and the control rats were intratracheally injected with 1 ml of sterile physiological saline in the same manner. The lung tissues of each group were collected at the corresponding time points after dusting. Three of the rats were taken out for pathological observation, and the other three were used to screen differentially expressed miRNAs in lung tissue by miRNA microarray technology. A549 cells were cultured at the in vitro cell level and divided into control group, SiO(2) stimulation group and TGF-β(1) stimulation group, and cells were collected at 12, 24 and 48 h after treatment. The expression levels of miRNA-29b-3p and miRNA-34c-3p in rat lung tissue and A549 cells were verified by real-time PCR (qRT-PCR), target gene prediction of miRNA-29b-3p and miRNA-34c-3p and perform GO enrichment analysis and KEGG pathway analysis. Results: The weight growth rate of the control group was significantly higher than that of the SiO(2) dusting group. Compared with the control group, the lung mass and lung coefficient of the SiO(2) dusting group were significantly increased (P<0.05). The inflammatory response of the lungs in the control group was significantly reduced at 21 and 28 days, and the inflammatory cells infiltrated in the lung tissue of the SiO2 group. The rats in the control group had a small amount of collagen at 21 and 28 days. A large amount of collagen fiber deposition began to appear in the lung tissue of rats exposed to SiO(2) for 21 days. Compared with the control group, the expression levels of miRNA-29b-3p and miRNA-34c-3p in the SiO(2) dusting group were significantly down-regulated, and there was significant difference compared with the control group (P<0.05). The expression levels of miRNA-29b-3p and miRNA-34c-3p in A549 cells treated with SiO(2) and human recombinant TGF-β1 were significantly lower than those in the control group at 24 h and 48 h, and the difference was statistically significant (P<0.05). Conclusion: Down-regulation of miRNA-29b-3p and miR-34c-3p in rat lung tissue A549 cells may be associated with the development of early silicosis and is expected to be an indicator of early silicosis diagnosis and prognosis.

The association between prenatal cadmium exposure and birth weight: A systematic review and meta-analysis of available evidence

We conducted a meta-analysis to evaluate the association between prenatal cadmium (Cd) exposure and birth weight. PubMed, Embase, China National Knowledge Infrastructure (CNKI), and Wanfang databases were searched for studies published before March 2019. We used a model-based method, standardizing effect size from linear regression models to include a maximum number of studies during our quantitative evaluations. As a result, 11 articles from the general population, containing 10 birth cohorts and one cross-sectional study, were included. Our meta-analysis demonstrated that a 50% increase of maternal urine Cd (UCd) would be associated with a 6.15 g decrease in neonatal birth weight (β = -6.15 g, 95% CI: -10.81, -1.49) as well as a 50% increase of maternal blood Cd (BCd) would be associated with an 11.57 g decrease (β = -11.57 g; 95% CI: -18.85, -4.30). Stratified analysis of UCd data indicated that the results of female newborns were statistically significant (β = -8.92 g, 95% CI: -17.51, -0.34), as was the first trimester (β = -11.34 g, 95% CI: -19.54, -3.14). Furthermore, increased UCd levels were associated with a higher rate of low birth weight (LBW) risk (OR = 1.12, 95% CI: 1.03, 1.22). This meta-analysis demonstrated that elevated maternal Cd levels are associated with decreased birth weight and higher LBW risk.

[Preliminary analysis of differential expression of miRNA-423-5p and miRNA-26a-5p in lung tissue of early silicotic rats]

Objective: To screen the changes of microRNA (miRNA) expression profiles in lung tissues of early silicosis rats, and provide a basis for functional analysis of differential microRNA. Methods: SPF Wistar male rats were randomly divided into a negative control group and SiO(2)-exposed groups, with 30 rats in each group. The model of silicosis in rats was established by intratracheal instillation of 1 ml SiO(2) suspension, and the control rats were treated with 1mL in the same way to sterilize normal saline. The lung tissues of two group were collected at the 1, 7, 14, 21, 28 d after SiO(2)-exposed. Three of the rat lung tissues were used for pathological observation, and the other three were used to screen differentially expressed miRNAs in lung tissue by miRNA microarray technology. miRNA chip screening and RT-qPCR were used to verify the expression levels of miRNA-423-5p and miRNA-26a-5p in the two groups. miRNA-423-5p and miRNA-26a-5p are predicted by target genes and analyzed by GO (gene ontology) enrichment analysis and KEGG (kyoto encyclopedia of genes and genomes) pathway analysis. Results: In the control group, the inflammatory response of lung tissue 21 and 28 days was significantly reduced compared with 1, 7 and 14 days, and the inflammatory cells infiltrated in the lung tissue of the SiO(2)-exposed rats. The rats in the control group had a small amount of collagen at 21 and 28 days, but a large amount of collagen fiber deposition began to appear in the lung tissue of rats exposed to SiO(2) after 21 days. Compared with the control group, the expression levels of micro RNA-423-5p was significantly up-regulated and the expression of microRNA-26a-5p was significantly down-regulated in the SiO(2)-exposed rats lung tissues dust at different time points (P<0.05) . Conclusion: The up-regulation of miRNA-423-5p and the down-regulation of miRNA-26a-5p in lung tissues of early silicotic rats may be related to the occurrence and development of early silicosis.

[Repair effect of adipose-derived mesenchymal stem cells on lung injury in rats exposed to silica]

Objective: To observe the repairing effect of adipose mesenchymal stem cells (ADSCs) on lung injury induced by silica in rats. Methods: Primary ADSCs-GFP was obtained from rats. ADSCs-GFP was injected into tail vein of silicosis model rats. The expression of green fluorescence in lungs was observed regularly to determine the homing ability of ADSCs. Primary ADSCs of rats were obtained and randomly divided into control group, exposure group, vehicle group and ADSCs group. Silicosis rat model was established by non-exposed tracheal drip method. 24 hours after silica exposure, rats in ADSCs group were injected with ADSCs of 1×10(6)/kg body weight through tail vein, and the pathological changes of lung tissue were observed and evaluated 28 days after intervention. To explore the early intervention mechanism of ADSCs on pulmonary fibrosis in silicosis model rats, apoptosis-related proteins were detected by immunohistochemistry. Results: 28 days after exposure to silica, rats in the exposure group showed obvious pulmonary fibrosis. Compared with exposure group and vehicle group, ADSCs group showed less pulmonary inflammation, less silica nodules and less collagen deposition area. Immunohistochemical results showed that the expression of Caspase-3 and cytochrome C protein decreased and Bcl-2 protein increased after ADSCs transplantation. Conclusion: ADSCs infusion has an obvious intervention effect on postponing early silicosis fibrosis in rats exposed to silica, and its mechanism is related to the regulation of apoptotic process.

Correction to: Rehmanniae Radix Preparata suppresses bone loss and increases bone strength through interfering with canonical Wnt/β-catenin signaling pathway in OVX rats

There was a mistake in the part of OVX rats model and RRP intervention in the original publication.

Rehmanniae Radix Preparata suppresses bone loss and increases bone strength through interfering with canonical Wnt/β-catenin signaling pathway in OVX rats

Rehmanniae Radix Preparata (RRP) improves bone quality in OVX rats through the regulation of bone homeostasis via increasing osteoblastogenesis and decreasing osteoclastogenesis, suggesting it has a potential for the development of new anti-osteoporotic drugs.

INTRODUCTION

Determine the anti-osteoporotic effect of RRP in ovariectomized (OVX) rats and identify the signaling pathway involved in this process.

METHODS

OVX rats were treated with RRP aqueous extract for 14 weeks. The serum levels of tartrate-resistant acid phosphatase (TRAP), receptor activator of nuclear factor kappa-Β ligand (RANKL), alkaline phosphatase (ALP), and osteoprotegerin (OPG) were determined by ELISA. Bone histopathological alterations were evaluated by H&E, Alizarin red S, and Safranin O staining. Bone mineral density (BMD) and bone microstructure in rat femurs and lumbar bones were determined by dual-energy X-ray absorptiometry and micro-computed tomography. Femoral bone strength was detected by a three-point bending assay. The expression of Phospho-glycogen synthase kinase 3 beta (p-GSK-3β), GSK-3β, Dickkopf-related protein 1 (DKK1), cathepsin K, OPG, RANKL, IGF-1, Runx2, β-catenin, and p-β-catenin was determined by western blot and/or immunohistochemical staining.

RESULTS

Treatment of OVX rats with RRP aqueous extract rebuilt bone homeostasis demonstrated by increasing the levels of OPG as well as decreasing the levels of TRAP, RANKL, and ALP in serum. Furthermore, RRP treatment preserved BMD and mechanical strength by increasing cortical bone thickness and epiphyseal thickness as well as improving trabecular distribution in the femurs of OVX rats. In addition, RRP downregulated the expression of DKK1, sclerostin, RANKL, cathepsin K, and the ratio of p-β-catenin to β-catenin, along with upregulating the expression of IGF-1, β-catenin, and Runx2 and the ratio of p-GSK-3β to GSK-3β in the tibias and femurs of OVX rats. Echinacoside, jionoside A1/A2, acetoside, isoacetoside, jionoside B1, and jionoside B2 were identified in the RRP aqueous extract.

CONCLUSION

RRP attenuates bone loss and improves bone quality in OVX rats partly through its regulation of the canonical Wnt/β-catenin signaling pathway, suggesting that RRP has the potential to provide a new source of anti-osteoporotic drugs.

[Serum levels of periostin and their influencing factors in the beta-lactam antibiotic enterprise workers]

Objective: To observe serum levels of periostin, ECP, IgE in the antibiotic enterprise workers, and study the role of periostin, ECP, IgE in the development of allergic inflammation. Methods: 90 cases with asthma or rhinitis were enrolled as disease group, another 117 workers exposed to 7-ACA、6-APA dust without suffering from allergic illness, are chosen as group of dust exposed, and 192 healthy workers who didn't contact dust were chosen as control group. Questionnaires were used to learn their basic information.Lung function was determined with a portable spirometer.The expression levels of periostin、ECP and IgE in serum were measured by enzyme-linked immuno sorbent assay. Results: The exposure group and disease group had significantly lower forced vital capacity (FVC) , forced expiratory volume in 1 second (FEV(l.0)) , and FEV(l.0)/FVC ratio than the control group (P<0.05) . The disease group had significantly higher eosinophil than the control group (P<0.05) . Compared with the control group, the exposure group, the disease group, asthma subgroup, rhinitis subgroup of serum periostin and IgE increased, the differences are statistically significant (P<0.05) . Serum levels of ECP in the workers of asthma subgroup were significantly higher than that in control group (P<0.05) . Serum expression levels of periostin were positively correlated with IgE, ECP in workers (P<0.001) , serum levels of periostin were negatively correlated with FEV(1.0) in workers (P<0.05) . Multiple logistics regression analysis found that exposure to 7-ACA or 6-APA (OR=3.09, 95%CI: 1.83-5.21) , age>47years (OR=2.53, 95%CI: 1.22-5.26) , higher ECP (OR=1.04, 95%CI: 1.01-1.06) were risk factors for increased serum periostin level. Conclusion: Occupational exposure to 7-ACA or 6-APA can result in higher serum periostin level, exposure to 7-ACA or 6-APA, age>47 years, higher ECP are risk factors for increased serum periostin level.

Baseline concentration of misfolded α-synuclein aggregates in cerebrospinal fluid predicts risk of cognitive decline in Parkinson's disease

BACKGROUND

The prognostic significance of misfolded α-synuclein (α-Syn) aggregates in Parkinson's disease (PD) has not been well investigated. The aim of this study was to reveal the relationship between misfolded α-Syn aggregate concentration in cerebrospinal fluid (CSF) and cognitive decline risk in PD.

METHODS

A total of 278 patients with PD were retrospectively included. They were diagnosed between 2011 and 2013. The end-point was 2016, and the follow-up period was 54.3 ± 10.0 months. Cognitive decline was defined as a 4-point decrease in the Mini-Mental State Examination score during follow-up. Misfolded α-Syn aggregate concentration in baseline CSF was measured using the protein misfolding cyclic amplification (PMCA) technique. Time to reach 50% of the maximum fluorescence value was recorded.

RESULTS

The PMCA technique successfully detected the level of misfolded α-Syn aggregates in CSF with a sensitivity of 85.3% and a specificity of 91.4%. The time to reach 50% of the maximum fluorescence value was shorter in the patients with cognitive decline than in the patients without cognitive decline (190.7 ± 40.1 h vs. 240.8 ± 45.6 h, P < 0.001). Multifactorial Cox regression analysis revealed that reaching 50% of the maximum fluorescence value in ≤219 h at baseline was associated with increased risk of cognitive decline during the follow-up (HR: 4.90, 95% CI: 2.75-8.74, P < 0.001).

CONCLUSION

Baseline concentration of misfolded α-Syn aggregates in CSF measured by the PMCA technique predicts risk of cognitive decline in PD.

[Distributed lag effects on the relationship between daily mean temperature and the incidence of bacillary dysentery in Lanzhou city]

OBJECTIVE

To discuss the lag effects of daily average temperature on the daily cases of bacillary dysentery in Lanzhou city.

METHODS

The data of daily cases of bacillary dysentery were collected during 2008 and 2015 in the city, and the meteorological data at the same period was integrated. The distributed lag non-linear model was used to analyze the relevance between daily average temperature and the daily cases of bacillary dysentery.

RESULTS

The exposure response relationship between the daily temperature and the incidence of bacillary dysentery was "J" type, the lowest incidence temperature was 17 °C, and the effect of high temperature on different gender and age groups was higher than that of the intermediate effect. The effect of high temperature and intermediate effect on the male and female groups showed an acute effect, the effect of the day was the highest, followed by fluctuations in temperature, and the greater the impact on women. In different age groups, high temperature effect and the intermediate effect of bacterial dysentery in 0-3 years old groups were the biggest; the effects of high and intermediate temperature on people aged 0-3 and 19-64 year all showed acute effects, which were the maximum value at the day, then decreased volatility; and for people aged over 65 years, the day after the onset, decreases and then increases slowly. There were obviously increasing risks of bacillary dysentery both the high temperature (32 °C) and the middle temperature (26 °C) with respect to 17 °C. The accumulative effects were highest at lag14 days, and the RR (95%CI) values of middle temperature was 2.30 (1.53-3.13), 2.45 (1.65-3.30), 2.41 (1.59-3.28), 2.54 (1.40-3.79), 1.82 (0.41-3.43), 1.98 (1.11-2.93), and 1.73 (0.68-2.88) among the males, females, 0-3 years old, 4-11 years old, 12-18 years old, 19-64 years old and over 65 years old people, respectively; while the high temperature was 2.93 (1.38-4.69), 3.08 (1.48- 4.90), 3.26 (1.60-5.16), 3.12 (1.06-5.56), 1.94 (0.73-5.39), 2.31 (0.54-4.36), and 2.06 (0.02-4.51), respectively.

CONCLUSION

The high temperature may increase risks of bacillary dysentery, and the females and younger people were the sensitive population. Meteorological factors play an important role in the occurrence and development of bacillary dysentery in Lanzhou. The incidence of bacillary dysentery is affected by multiple meteorological factors, but the primary one is high temperature. The temperature has not a direct effect on the incidence of bacillary dysentery, but an indirect influence in different populations through the impacts of various aspects of the incidence of bacterial dysentery (residents living habits, communication channels and the habits of the susceptible population).

[Pollution characteristics and health risk assessment of heavy metals in PM(2.5) in Lanzhou]

Objective: To understand the pollution characteristics and assess the pollution health risks of heavy metals in atmospheric PM(2.5) in Lanzhou. Methods: According to the regional characteristics of air pollution and industrial distribution characteristics in Lanzhou, atmospheric PM(2.5) was sampled monthly in Chengguan and Xigu Districts from January, 2015 to December, 2016. Detected the concentration of PM(2.5) and 12 kinds of elements (Sb, Al, As, Be, Cd, Cr, Hg, Pb, Mn, Ni, Se and Tl) by weighing method and inductively coupled plasma mass spectrometry. Enrichment factor and geo-accumulation index were used to describe the pollution characteristics, while health risk assessment was conducted using the recommended United States Environmental Protection Agency (USA EPA) model. The health risks of non-carcinogens were evaluated by non-cancer hazard quotient (HQ), the non-carcinogenic risk was considered to be negligible when HQ<1, HQ>1 meant a health risk. With a single contaminant cancer Risk value to evaluate the health risks of carcinogens, when the Risk value between 10(-6) to10(-4) as an acceptable level. Results: The daily average concentrations of PM(2.5) was 83.0 μg/m(3), 77.0 μg/m(3) in Chengguan and Xigu Districts, respectively, during the sampling periods, and the concentration of PM(2.5) in winter/spring was higher than summer/fall in both districts. The concentration of Al in PM(2.5) was the highest and other elements in descending order: Pb, Mn, As, Sb/Cd, Tl in both districts. Enrichment factor results showed that Al and Mn were mainly affected by natural factors, the rest of five elements were all typical man-made pollution elements and according to geo-accumulation index pollution level of Cd was the strongest in the winter. The results of health risk assessment showed that Mn had the highest non-cancer risks (HQ>1) and affected the health of the children seriously. HQ reached up to 2.44 and 1.79 in Chengguan and Xigu Districts, respectively. Pb, As, Sb, Cd had slight health impact (HQ<1), could be negligible. The cancer risks range of As, Cr were 6.33×10(-6) to 6.46×10(-5) between the acceptable level of risk (10(-6) to 10(-4)), which indicated that As and Cd had potential cancer-risks. Conclusions: The pollution level of atmospheric PM(2.5) and the heavy metals in it was still grim;the non-cancer risks caused by multiple metals on children deserved attention. Although the cancer risks of As and Cd were between the acceptable level of risk, the potential cancer risk still shall not be ignored.

Quantitative structure-activity relationship of anti-HIV integrase and reverse transcriptase inhibitors using norm indexes

The development of new and safe anti-human immunodeficiency virus (anti-HIV) drugs has been an urgent task for medical research recently. Herein, based on the norm-index descriptors proposed in this work and previous works, a couple of models were developed for investigating the quantitative structure-activity/toxicity relationship (QSAR/QSTR) of dual-target anti-HIV integrase (IN) and reverse transcriptase (RT) inhibitors. The validation results proved that the developed models were stable and reliable, both in statistical quality and predictive capacity. Moreover, potential dual-target inhibitors with high activity and low toxicity were deduced from the developed models; molecular docking results indicated that these inhibitors could interact with some important residues of HIV IN and RT through H-bonding. Accordingly, the norm indexes descriptors proposed by this work might be helpful for the research and development of dual-target anti-HIV drugs.

dbMDEGA: a database for meta-analysis of differentially expressed genes in autism spectrum disorder

Background

Autism spectrum disorders (ASD) are hereditary, heterogeneous and biologically complex neurodevelopmental disorders. Individual studies on gene expression in ASD cannot provide clear consensus conclusions. Therefore, a systematic review to synthesize the current findings from brain tissues and a search tool to share the meta-analysis results are urgently needed.

Methods

Here, we conducted a meta-analysis of brain gene expression profiles in the current reported human ASD expression datasets (with 84 frozen male cortex samples, 17 female cortex samples, 32 cerebellum samples and 4 formalin fixed samples) and knock-out mouse ASD model expression datasets (with 80 collective brain samples). Then, we applied R language software and developed an interactive shared and updated database (dbMDEGA) displaying the results of meta-analysis of data from ASD studies regarding differentially expressed genes (DEGs) in the brain.

Results

This database, dbMDEGA (https://dbmdega.shinyapps.io/dbMDEGA/), is a publicly available web-portal for manual annotation and visualization of DEGs in the brain from data from ASD studies. This database uniquely presents meta-analysis values and homologous forest plots of DEGs in brain tissues. Gene entries are annotated with meta-values, statistical values and forest plots of DEGs in brain samples. This database aims to provide searchable meta-analysis results based on the current reported brain gene expression datasets of ASD to help detect candidate genes underlying this disorder.

Conclusion

This new analytical tool may provide valuable assistance in the discovery of DEGs and the elucidation of the molecular pathogenicity of ASD. This database model may be replicated to study other disorders.

Electronic supplementary material

The online version of this article (10.1186/s12859-017-1915-2) contains supplementary material, which is available to authorized users.

[Effect of mitogen-activated protein kinase signaling pathway on apoptosis induced by chloroacetic acid in human normal bronchial epithelial 16HBE cells]

Objective: The aim of this study was to investigate the effect of mitogen-activated protein kinase (MAPK) signaling pathway on apoptosis induced by chloroacetic acid in human normal bronchial epithelial 16HBE cells. Methods: 16HBE cells were exposed to 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 mmol/L chloroacetic acid for 24 h in vitro. The cytotoxicity induced by chloroacetic acid was assessed by CCK-8 and LDH assays. Cell apoptosis was detected by Annexin V-FITC and PI staining. The protein expression levels of phosphorylation of p38, ERK1/2 and JNK were determined by western blotting. 16HBE cells were pretreated with MAPK signaling pathway specific inhibitors including SB203580, U0126 and SP600125 for 1 h, and these cells were subsequently treated with 2.5 mmol/L chloroacetic acid for 24 h. The expressions of p-p38, p-ERK1/2 and p-JNK as well as the changes of cell viability and apoptosis were measured after pretreated with inhibitors for 1 h. Results: The cell viability by CCK-8 and LDH methods gradually reduced in a dose-dependent manner when chloroacetic acid concentrations elevated (P<0.05) , and their correlation coefficients were -0.902 and -0.825, respectively. The detection efficiency of CCK-8 assay significantly increased compared with LDH assay (P<0.05) . The cell apoptosis rates, which were (17.2±4.0) %, (24.6± 4.2) %, (39.3 ± 5.7) % in 1.5, 2.0, 2.5 mmol/L chloroacetic acid-treated groups, were higher than that of the control group[ (5.6 ± 3.0) %] (P<0.05) . There was a time-or dose-dependent change in the protein expressions of p-p38, p-ERK1/2 and p-JNK. Compared with the control, the levels of p-p38 had 2.1 and 2.6-fold increases in 16 and 24 h treated groups (P<0.01) , while the levels of p-ERK1/2 distinctly decreased by 37% and 52% (P<0.01) . In comparison with the control group, the expressions of p-p38 had 1.9 and 2.6-fold increases in 1.5 and 2.5 mmol/L treatment groups (P<0.01) , whereas the expressions of p-ERK1/2 significantly decreased by 40% and 50% (P<0.01) . No significant change was observed in p-JNK protein expression between the chloroacetic acid-treated and control groups. In comparison with the vehicle control and the exposed group, p-p38, p-ERK1/2, p-JNK protein expressions significantly declined in the inhibitor controls and inhibitor groups. Compared with the controls, the cell survival rates had significant reductions of 28%, 18%, 36% and 26% respectively in chloroacetic acid treated group, SB203580 group, U0126 group and SP600125 group, and the apoptosis rates in the abovementioned groups were 7, 4, 8 and 7 times. Compared with chloroacetic acid-treated group, the cell viability increased by 14% in SB203580 group and decreased by 11% in U0126 group, and the cell apoptosis rates decreased by 36% in SB203580 group and increased by 18% in U0126 group (P<0.05) . But no significant changes were observed in cell viability and apoptosis between SP600125 and chloroacetic acid-treated group. Conclusion: Chloroacetic acid might activate p38 MAPK signaling pathway and inhibit ERK1/2 MAPK signaling pathway. The signaling pathways of p38 and ERK1/2 MAPK are involved in 16HBE cell apoptosis induced by chloroacetic acid, but JNK is not involved in chloroacetic acid-induced 16HBE cell apoptosis.