Sympathetic hyperinnervation drives abdominal aortic aneurysm development by promoting vascular smooth muscle cell phenotypic switching.

INTRODUCTION: Sympathetic hyperinnervation plays an important role in modulating the vascular smooth muscle cell (VSMC) phenotype and vascular diseases, but its role in abdominal aortic aneurysm (AAA) is still unknown. OBJECTIVES: This study aimed to investigate the role of sympathetic hyperinnervation in promoting AAA development and the underlying mechanism involved. METHODS: Western blotting and immunochemical staining were used to detect sympathetic hyperinnervation. We performed sympathetic denervation through coeliac ganglionectomy (CGX) and 6-OHDA administration to understand the role of sympathetic hyperinnervation in AAA and investigated the underlying mechanisms through transcriptome and functional studies. Sema4D knockout (Sema4D-/-) mice were utilized to determine the involvement of Sema4D in inducing sympathetic hyperinnervation and AAA development. RESULTS: We observed sympathetic hyperinnervation, the most important form of sympathetic neural remodeling, in both mouse AAA models and AAA patients. Elimination of sympathetic hyperinnervation by CGX or 6-OHDA significantly inhibited AAA development and progression. We further revealed that sympathetic hyperinnervation promoted VSMC phenotypic switching in AAA by releasing extracellular ATP (eATP) and activating eATP-P2rx4-p38 signaling. Moreover, single-cell RNA sequencing revealed that Sema4D secreted by osteoclast-like cells induces sympathetic nerve diffusion and hyperinnervation through binding to Plxnb1. We consistently observed that AAA progression was significantly ameliorated in Sema4D-deficient mice. CONCLUSIONS: Sympathetic hyperinnervation driven by osteoclast-like cell-derived Sema4D promotes VSMC phenotypic switching and accelerates pathological aneurysm progression by activating the eATP/P2rx4/p38 pathway. Inhibition of sympathetic hyperinnervation emerges as a potential novel therapeutic strategy for preventing and treating AAA.

Clearance of Stress-Induced Premature Senescent Cells Alleviates the Formation of Abdominal Aortic Aneurysms.

Abdominal aortic aneurysm (AAA) is a multifactorial disease characterized by various pathophysiological processes, including chronic inflammation, oxidative stress, and proteolytic activity in the aortic wall. Stress-induced premature senescence (SIPS) has been implicated in regulating these pathophysiological processes, but whether SIPS contributes to AAA formation remains unknown. Here, we detected SIPS in AAA from patients and young mice. The senolytic agent ABT263 prevented AAA development by inhibiting SIPS. Additionally, SIPS promoted the transformation of vascular smooth muscle cells (VSMCs) from a contractile phenotype to a synthetic phenotype, whereas inhibition of SIPS by the senolytic drug ABT263 suppressed VSMC phenotypic switching. RNA sequencing and single-cell RNA sequencing analysis revealed that fibroblast growth factor 9 (FGF9), secreted by stress-induced premature senescent VSMCs, was a key regulator of VSMC phenotypic switching and that FGF9 knockdown abolished this effect. We further showed that the FGF9 level was critical for the activation of PDGFRß/ERK1/2 signaling, facilitating VSMC phenotypic change. Taken together, our findings demonstrated that SIPS is critical for VSMC phenotypic switching through the activation of FGF9/PDGFRß/ERK1/2 signaling, promoting AAA development and progression. Thus, targeting SIPS with the senolytic agent ABT263 may be a valuable therapeutic strategy for the prevention or treatment of AAA.

Association of long-term time in target range for systolic blood pressure with cardiovascular risk in the elderly: a Chinese veteran cohort study.

AIMS: Short-term blood pressure (BP) time in target range (TTR) independently predicts cardiovascular (CV) outcomes in adults. However, there are limited data regarding long-term TTR for BP among elderly participants. We aimed to determine whether future CV risk varies for those who can maintain a long-term systolic BP (SBP) target range by assessing TTR in elderly individuals with hypertension. METHODS AND RESULTS: The Chinese veteran cohort study included 943 elderly participants with hypertension aged over 75 years. The primary outcome was the first occurrence of CV events during annual visits. Time in target range was estimated over 15 years of follow-up using linear interpolation. The target range was defined as 120-140 mmHg according to guidelines. The association between SBP TTR and CV outcomes was estimated using multivariable Cox proportional hazards models. During the 15 year follow-up, the probability of CV events gradually decreased with increasing TTR for SBP. After multivariable adjustment for traditional CV risk factors and mean BP, comparing the highest vs. lowest quartiles of TTR for SBP, the hazard ratios (HRs) [95% confidence intervals (CIs)] were 0.424 (0.289-0.624) for the primary outcome. For each 1 SD increase in TTR, the risk of the primary outcome decreased by 25.4% (HR: 0.746; 95% CI: 0.666-0.834). Consistent findings were observed in sensitivity analyses. CONCLUSION: Greater long-term TTR for SBP was associated with a decreased risk of CV events in elderly individuals independent of mean BP, suggesting that SBP TTR might serve as a modifiable risk factor for future CV health in elderly patients with hypertension. LAY SUMMARY: This ongoing Chinese veteran cohort study adds to the understanding of the relationship between higher long-term systolic blood pressure (SBP) time in target range (TTR) and cardiovascular benefits among elderly individuals with hypertension.

Higher long-term systolic blood pressure (SBP) time in target range (TTR) is associated with a significantly decreased risk of cardiovascular events independent of mean SBP, suggesting that TTR might serve as an essential measure for monitoring BP status. It might be helpful for lowering the risk of cardiovascular events when the time in SBP target range is maintained after antihypertensive therapy.

Extracellular vesicle-derived CircWhsc1 promotes cardiomyocyte proliferation and heart repair by activating TRIM59/STAT3/Cyclin B2 pathway.

INTRODUCTION: Extracellular vesicles (EVs)-mediated cell-to-cell communication is crucial for hypoxia-induced cell proliferation and tissue repair, but its function in endogenous cardiac regeneration is still unknown. OBJECTIVES: Herein, we aimed to determine whether hypoxia-inducible circWhsc1 in endothelial EVs promoted cardiomyocyte (CM) proliferation and cardiac regeneration. METHODS: RNA-sequence data was used to identify EV circRNAs that were involved into endogenous cardiac regeneration. Quantitative polymerase chain reactions were conducted to determine circRNA expression in tissue, cells and EVs. Gain- and loss-of-function assays were performed to explore the function of EV-derived circWhsc1 during cardiac regeneration. Western blotting and RNA pulldown assays were used to investigate its underlying mechanism. RESULTS: We found that circWhsc1 was enriched in neonatal mouse hearts, particularly in cardiac ECs, and was further upregulated both in ECs and EC-derived EVs under hypoxic conditions. When cocultured with hypoxia-preconditioned neonatal ECs or their secreted EVs, both neonatal and adult CMs exhibited an increased proliferation rate and G2/M ratio, which could be attenuated by knockdown of circWhsc1 in ECs. In vivo, EC-restricted overexpression of circWhsc1 and EV-mediated delivery of circWhsc1 induced CM proliferation, alleviated cardiac fibrosis and restored cardiac function following myocardial infarction in adult mice. Mechanistic studies revealed that EV-derived circWhsc1 activated TRIM59 by enhancing its phosphorylation, thereby reinforcing the binding of TRIM59 to STAT3, phosphorylating STAT3 and inducing CM proliferation. CONCLUSION: The current study demonstrated that hypoxia-inducible circWhsc1 in EC-derived EVs induces CM proliferation and heart regeneration. EC-CM communication mediated by EV-derived circWhsc1 might represent a prospective therapeutic target for inducing cardiac repair post-myocardial infarction.

miRNA-mRNA network regulation in the skeletal muscle fiber phenotype of chickens revealed by integrated analysis of miRNAome and transcriptome.

Skeletal muscle fibers are primarily categorized into oxidative and glycolytic fibers, and the ratios of different myofiber types are important factors in determining livestock meat quality. However, the molecular mechanism for determining muscle fiber types in chickens was hardly understood. In this study, we used RNA sequencing to systematically compare mRNA and microRNA transcriptomes of the oxidative muscle sartorius (SART) and glycolytic muscle pectoralis major (PMM) of Chinese Qingyuan partridge chickens. Among the 44,705 identified mRNAs in the two types of muscles, 3,457 exhibited significantly different expression patterns, including 2,364 up-regulated and 1,093 down-regulated mRNAs in the SART. A total of 698 chicken miRNAs were identified, including 189 novel miRNAs, among which 67 differentially expressed miRNAs containing 42 up-regulated and 25 down-regulated miRNAs in the SART were identified. Furthermore, function enrichment showed that the differentially expressed mRNAs and miRNAs were involved in energy metabolism, muscle contraction, and calcium, peroxisome proliferator-activated receptor (PPAR), insulin and adipocytokine signaling. Using miRNA-mRNA integrated analysis, we identified several candidate miRNA-gene pairs that might affect muscle fiber performance, viz, gga-miR-499-5p/SOX6 and gga-miR-196-5p/CALM1, which were supported by target validation using the dual-luciferase reporter system. This study revealed a mass of candidate genes and miRNAs involved in muscle fiber type determination, which might help understand the molecular mechanism underlying meat quality traits in chickens.

Integrative profiling analysis identifies the oncogenic long noncoding RNA DUXAP8 in oral cancer.

A growing number of studies have revealed the critical roles of long noncoding RNAs (lncRNAs) in the tumorigenesis and cancer progression. Recently, next-generation sequencing technologies combined with bioinformatic have demonstrated that a great number of dysregulated lncRNAs are associated with diverse cancers. However, lots of lncRNAs' function and their underlying molecular mechanisms in oral carcinoma (OC) cancer remain unclear. In this study, we performed integrative lncRNA profiling analysis using the TCGA RNA sequencing data and gene microarray data from Gene Expression Omnibus to identify more OC associated lncRNAs. A total of 619 differentially expressed lncRNAs were identified between the five data sets, and only the double homeobox A pseudogene 8 (DUXAP8) was screened among the up-regulated lncRNAs in all the five groups. Meanwhile, univariate Cox regression analyses disclosed that some lncRNAs are associated with the outcome of OC patients, such as DUXAP8, LINC00152, MIR4435-2HG and LINC00582. Furthermore, we uncovered that silenced DUXAP8 expression exerted suppressive impact on the proliferation of OC cells through interacting with histone-lysine N-methyltransferase enzyme Enhancer of zeste homolog 2 (EZH2) and repressing KLF2 expression. In a word, we identified a lot of unreported OC associated lncRNAs, which may provide a useful resource of lncRNAs for other studies.

Effects of Soil Properties and Land Use Types on the Bioaccessibility of Cd, Pb, Cr, and Cu in Dongguan City, China.

In order to determine the potential heavy metal contamination in soil across Dongguan City, 124 soil samples from seven land use types were collected, four heavy metals (Cd, Pb, Cr, and Cu) were analyzed. Total Cd, Cr, and Cu contents were significantly higher than the background values for Guangdong Province. Lead bioaccessibility in urban green land was lower than that in industrial and abandoned districts. The bioaccessibility of heavy metals was affected by total metal concentrations, soil properties, and land use types. The results showed that there was a negative correlation between the bioaccessibility of heavy metals (except for Cu) and their total concentrations. Soil pH and organic matter were the main factors affecting the bioaccessibility of Cd, Cr, Pb, and Cu in most land use types. Furthermore, sand, P, and clay also affected Pb, Cr, and Cu bioaccessibility. With the exception of the industrial zone periphery and urban green land, the bioaccessibility of heavy metals was mainly affected by clay.

Identification of multiple dysregulated metabolic pathways by GC-MS-based profiling of liver tissue in mice with OVA-induced asthma exposed to PM2.5.

Particulate matter (PM) exposure increases the risk of asthma. However, the effect of PM2.5 exposure on liver metabolism in mice with asthma symptoms remains unclear. We established an ovalbumin (OVA)-induced asthma model in mice and divided the animals into four groups: control group (C), PM2.5 exposure group (P), OVA-induced asthma group (O) and OVA-induced asthma PM2.5 exposure group (OP). Gas chromatography-mass spectrometry (GC-MS) was used to identify the metabolite markers and related perturbed metabolic pathways in mouse liver tissue after PM2.5 exposure. Multivariate analysis showed 9 and 12 potential metabolite markers in the P and OP groups, respectively, after PM2.5 exposure that were significantly correlated with lipid peroxidation indices. PM2.5 exposure perturbed 5 and 7 metabolic pathways in the P and OP groups, respectively. These metabolic pathways mainly involve the lipid metabolism, amino acid metabolism, carbohydrate metabolism, and nucleotide metabolism. These results highlight the potential to study PM2.5-triggered alterations via liver tissue in normal and OVA-induced asthmatic mice to gain a more realistic appraisal of the resulting early toxicity events. Additionally, these results revealed potential metabolite markers of early antioxidant defense events triggered by PM2.5 and indicated that metabolite markers are more sensitive than antioxidant indicators.

Identification of multiple dysregulated metabolic pathways by GC-MS-based profiling of lung tissue in mice with PM2.5-induced asthma.

The risk of development of asthma, a multi-faceted chronic disease, increases as a result of exposure to PM2.5. However, the mechanism underlying asthma-related metabolic changes caused by PM2.5 exposure is unclear. Here, we investigated the major metabolic changes, metabolic pathways involved, and underlying molecular mechanisms in mice with PM2.5 exposure-induced asthma. Forty-eight adult female mice were randomly assigned to control (C), low concentration-PM2.5 exposure: 0.50 mg kg-1 (L), medium concentration-PM2.5 exposure: 1.58 mg kg-1 (M), and high concentration-PM2.5 exposure: 4.98 mg kg-1 (H) groups. M and H groups presented significantly higher IL-4, IL-8, IL-1ß, IL-5, IL-13, and OVA-specific IgE levels, and significantly lower IFN-γ levels, than the C group, as well as significantly increased eosinophil count and MUC5AC expression in the lung tissue. These findings indicate that exposure to medium and high concentrations of PM2.5 induced asthma in mice. Statistical analyses identified 13 asthma-related major metabolites, which were analyzed by gas chromatography-mass spectrometry (GC-MS). Meta Mapp Software revealed 4 major metabolic pathways. PM2.5-induced ATP requirement and oxidative stress may perturb metabolic processes in asthma. The present findings increase our understanding of the toxic effect of PM2.5 in the development of asthma and identify potentially useful biomarkers.

Inhibition of miR­21 promotes cell apoptosis in oral squamous cell carcinoma by upregulating PTEN.

MicroRNA­21 (miR­21) has been identified as an oncogene and confirmed to serve an important role in carcinogenesis in various types of cancer. However, the effect and mechanism of miR­21 in oral squamous cell carcinoma (OSCC) has not been fully elucidated. In the present study, miR­21 inhibitor and empty vector were transfected into OSCC cells, and non­transfected cells were used as a blank control. The results indicated that when compared with the control and scramble groups, miR­21 inhibitor suppressed the expression of miR­21. Conversely, phosphatase and tensin homolog deletion on chromosome 10 (PTEN) was markedly upregulated, and a dual luciferase reporter assay revealed PTEN to be a target gene of miR­21. Furthermore, miR­21 inhibitor decreased the proliferation and invasion and enhanced the apoptosis of OSCC cells. There was no significant difference in cell proliferation, invasion and apoptosis between the control and scramble groups. The present data suggested that there may be a regulatory loop between miR­21 and PTEN, and that miR­21 inhibition affected the proliferative, invasive and apoptotic abilities of OSCC cells. These findings indicate that miR­21 may be a possible novel target in the treatment of OSCC.

[Subclavian artery stenosis combined with vertebral artery stenosis may lead to compensatory blood flow changes in the contralateral vertebral artery].

OBJECTIVE: To investigate the severity of blood steal and the hemodynamic profiles in patients with subclavian artery stenosis combined with vertebral artery stenosis. METHODS: A retrospective analysis was performed of transcranial Doppler (TCD) data from patients with subclavian artery stenosis (SAS) and concomitant unilateral/bilateral vertebral artery stenosis (VAS, >50%) or occlusion in our institution between February, 2014 and July, 2018.Thirty-seven patients with SAS combined with VAS (SAS+VAS) were reviewed for types of blood steal, peak systolic velocities of blood flow in affected subclavian artery and the contralateral vertebral artery, and the findings of hyperemia testing.These data were also reviewed for 39 SAS patients without VAS (control group) for comparison of blood steal and hemodynamic profiles. RESULTS: In SAS+VAS group, 5 patients showed no blood steal; blood steal in stage Ⅰ was found in 22 patients, stage Ⅱ in 7, and stage Ⅲ in 3, as compared to the numbers of 17, 12 and 10 in the control group, respectively (H=9.431, P=0.002).The peak systolic velocity of the contralateral vertebral artery was 43.91±17.43 cm/s in SAS+VAS group, significantly lower than that in the control group (53.56±17.45 cm/s; t= 629.5, P=0.006).Hyperemia testing showed a significant difference in the negative rate between SAS+VAS group and the control group[35.1%(13/37) vs 7.7%(3/39);χ2=8.603, P=0.003). CONCLUSIONS: SAS combined with VAS may lead to reduced compensatory blood flow in the contralateral vertebral artery to lessen the severity of subclavian steal syndrome.

The complete mitochondrial genome sequence of Colossoma macropomum (Characiformes: Serrasalmidae).

Colossoma macropomum (Cuvier, 1816) is the largest characin of South America. This species and its congeners mainly feed on zooplankton, insects, snails and decaying plants. In this paper, we sequenced and annotated the complete mitogenome of C. macropomum. The total length is 16,703 bp, and it typically consist of 37 genes, including 13 protein-coding genes, two rRNAs, 22 tRNA, a light-strand replication origin (OL) and a large control region (D-loop). The overall base composition is 29.9%, 24.6%, 29.5% and 15.9% for A, T, C and G, respectively, with a slight bias on AT content (54.6%). All protein-coding genes share the start codon ATG, except for COI, which begins with GTG. Most of them have TAA or TAG as the stop codon, except COII, ND4 use AGA and COI, Cytb use an incomplete stop codon T. This information could provide useful molecular data and contribute to further phylogenetic studies of Characiformes and Serrasalmidae.

Mitochondrial damage: an important mechanism of ambient PM2.5 exposure-induced acute heart injury in rats.

Epidemiological studies suggested that ambient fine particulate matter (PM2.5) exposure was associated with cardiovascular disease. However, the underlying mechanism, especially the mitochondrial damage mechanism, of PM2.5-induced heart acute injury is still unclear. In this study, the alterations of mitochondrial morphology and mitochondrial fission/fusion gene expression, oxidative stress, calcium homeostasis and inflammation in hearts of rats exposed to PM2.5 with different dosages (0.375, 1.5, 6.0 and 24.0mg/kg body weight) were investigated. The results indicated that the PM2.5 exposure induced pathological changes and ultra-structural damage in hearts such as mitochondrial swell and cristae disorder. Furthermore, PM2.5 exposure significantly increased specific mitochondrial fission/fusion gene (Fis1, Mfn1, Mfn2, Drp1 and OPA1) expression in rat hearts. These changes were accompanied by decreases of activities of superoxide dismutase (SOD), Na(+)K(+)-ATPase and Ca(2+)-ATPase and increases of levels of malondialdehyde (MDA), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) as well as levels of pro-inflammatory mediators including TNF-α, IL-6 and IL-1ß in rat hearts. The results implicate that mitochondrial damage, oxidative stress, cellular homeostasis imbalance and inflammation are potentially important mechanisms for the PM2.5-induced heart injury, and may have relations with cardiovascular disease.

Effect of ambient PM(2.5) on lung mitochondrial damage and fusion/fission gene expression in rats.

Exposure to ambient fine particulate matter (PM2.5) increases the risk of respiratory disease. Although previous mitochondrial research has provided new information about PM toxicity in the lung, the exact mechanism of PM2.5-mediated structural and functional damage of lung mitochondria remains unclear. In this study, changes in lung mitochondrial morphology, expression of mitochondrial fission/fusion markers, lipid peroxidation, and transport ATPase activity in SD rats exposed to ambient PM2.5 at different dosages were investigated. Also, the release of reactive oxygen species (ROS) via the respiratory burst in rat alveolar macrophages (AMs) exposed to PM2.5 was examined by luminol-dependent chemiluminescence (CL). The results showed that (1) PM2.5 deposited in the lung and induced pathological damage, particularly causing abnormal alterations of mitochondrial structure, including mitochondrial swelling and cristae disorder or even fragmentation in the presence of higher doses of PM2.5; (2) PM2.5 significantly affected the expression of specific mitochondrial fission/fusion markers (OPA1, Mfn1, Mfn2, Fis1, and Drp1) in rat lung; (3) PM2.5 inhibited Mn superoxide dismutase (MnSOD), Na(+)K(+)-ATPase, and Ca(2+)-ATPase activities and elevated malondialdehyde (MDA) content in rat lung mitochondria; and (4) PM2.5 induced rat AMs to produce ROS, which was inhibited by about 84.1% by diphenyleneiodonium chloride (DPI), an important ROS generation inhibitor. It is suggested that the pathological injury observed in rat lung exposed to PM2.5 is associated with mitochondrial fusion-fission dysfunction, ROS generation, mitochondrial lipid peroxidation, and cellular homeostasis imbalance. Damage to lung mitochondria may be one of the important mechanisms by which PM2.5 induces lung injury, contributing to respiratory diseases.

Effects of 2-amino-1-methyl-6-phenylimidazo [4, 5-b] pyridine (PhIP) on histopathology, oxidative stress, and expression of c-fos, c-jun and p16 in rat stomachs.

2-Amino-1-methyl-6-phenylimidazo [4, 5-b] pyridine (PhIP) is one of the most abundant heterocyclic amines (HCAs) generated from overcooking meat at high temperatures. To understand the possible mechanism of PhIP-associated stomach cancer, the effects of PhIP on morphology, oxidative stress, gene expression of c-fos, c-jun and p16 in rat stomachs were investigated. The results showed that (1) 15mg/kg body weight PhIP induced obvious histopathological changes in gastric mucosa; (2) PhIP (10 and/or 15mg/kg) significantly decreased superoxide dismutase (SOD) and glutathioneperoxidase (GPx) activities, while increased catalase (CAT) activity compared with the control. With the elevated doses of PhIP, malondialdehyde (MDA) contents, protein carbonyl (PCO) contents and DNA-protein crosslinks (DPC) coefficients were significantly raised in a dose-dependent manner; (3) PhIP at the doses of 10mg/kg and/or 15mg/kg significantly inhibited p16 mRNA and protein expression, whereas enhanced c-fos and c-jun expression relative to control. The data indicated that PhIP could cause stomach injury, oxidative stress in rat stomachs as well as the activation of c-fos and c-jun and inactivation of p16, which may play a role in the pathogenesis of PhIP-associated stomach cancer.

[Lipid peroxidation in different tissues of rats treated with 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine].

OBJECTIVE: To study the effects of 2-amino-1-methyl-6-phenylimidazo [4, 5-b] pyridine (PhIP) (a kind of heterocyclic amines) on lipid peroxidation in the heart, lung, liver and kidney of rats. METHODS: Rats were divided into a normal control group and three PhIP groups exposed to different doses of PhIP (5, 10 and 15 mg/kg body weight) by gavage. The indexes of lipid peroxidation were measured 24 hours after gavaging. RESULTS: In comparison with the control group, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were increased in hearts and lungs while were significantly inhibited in livers of rats in PhIP groups at the doses of 10 and 15 mg/kg body weight (P < 0.05 or P < 0.01). There was no significant change in kidneys. Moreover, malondialdehyde (MDA) levels in the tissues of rats increased with a dose-dependent manner for PhIP exposure. CONCLUSION: PhIP could cause lipid peroxidation in the heart, lung, liver and kidney of rats, and such effects were varied in different organs.

Effects of sulfur dioxide on expressions of p53, bax and bcl-2 in lungs of asthmatic rats.

Inhibition of cell apoptosis is an increasingly important factor in modulating airway inflammation in asthma, which is related to environmental pollutants. To investigate the effects of sulfur dioxide (SO(2)) on the mRNA and protein expressions of apoptosis-related genes in lungs from asthmatic rats, male Wistar rats were challenged by ovalbumin (OVA) or SO(2) (2 ppm) inhalation alone or together. Examinations were performed 24 h after the last treatment. The mRNA and protein levels of p53, bax, and bcl-2 were analyzed in lungs using real-time reverse transcription-polymerase chain reaction (RT-PCR) assay and Western blot analysis, respectively. The results indicated that increases of bcl-2 or decreases of p53 and bax mRNA and protein levels were not significant in lungs of rats exposed to SO(2) alone, compared with controls, but elevated or reduced levels of these genes appeared in lungs of asthmatic rats exposed to SO(2) plus OVA, compared with controls, suggesting that SO(2) exposure could result in OVA-induced increases or decreases of transcription and translation levels of these apoptosis-related genes in rat lungs, and may have relations to airway inflammation in asthma. The regulation mechanism of apoptosis in asthma disease exposure to SO(2) needs further study.

Effects of sulfur dioxide on the expressions of EGF, EGFR, and COX-2 in airway of asthmatic rats.

The pathogenesis of asthma involves a combination of genetic and environmental factors. The epidemiology studies have shown that SO(2)might play an important role in the initiation or exacerbation of the asthma disease. To investigate the asthmatic molecular mechanisms exposed to SO(2), male Wistar rats were divided randomly into four equal groups of six animals each: (1) SO(2) group, (2) ovalbumin (OVA) group (asthma group), (3) SO(2)plus OVA group, and (4) control group. The rats were challenged by ovalbumin (OVA) or SO(2) (5.6 mg/m(3)) inhalation alone or together. The mRNA and protein levels of asthma-related genes (EGF, EGFR, and COX-2) were analyzed in lungs and tracheas using real-time reverse transcription-polymerase chain reaction assay, radioimmunoassay method, and Western blot analysis, respectively. The results showed that inhaled SO(2) alone increased the mRNA and protein expressions of three tested genes in lung and trachea tissues, but only the mRNA levels of EGFR and COX-2 in tracheas were significantly increased compared with the control. However, OVA exposure significantly induced the mRNA and protein expressions of EGF, EGFR, and COX-2 compared with the control. Meanwhile, OVA plus SO(2) inhalation enhanced the mRNA and protein levels of these genes in rat airways, versus exposure to OVA alone. These results suggested that SO(2) could increase the expressions of EGF, EGFR, and COX-2 on the transcription and translation levels in the lungs and tracheas from asthmatic rats, which might be one of the possible mechanisms by which SO(2) pollution aggravates asthma disease.

Effects of sulfur dioxide derivatives on four asthma-related gene expressions in human bronchial epithelial cells.

Sulfur dioxide (SO(2)) is a common air pollutant, and inhaled SO(2) in airway epithelium easily forms its soluble derivatives in vivo (bisulfite and sulfite), which are toxic to the respiratory system and related to the exacerbation of asthma. In order to study the possible asthmatic molecular mechanism of SO(2) and its derivatives, the dose-response and time-response relationships of SO(2) derivatives on gene expressions of some asthma-related genes in human bronchial epithelial cells (BEP2D) were investigated. The mRNA and protein levels of EGF, EGFR, ICAM-1 and COX-2 were analyzed in BEP2D cells using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) assay, radio-immunoassay (RIA) method and Western blot analysis, respectively. The results showed that SO(2) derivatives caused the dose-dependent inductive expressions of four gene mRNA and protein in BEP2D cells. Moreover, SO(2) derivatives significantly increased the mRNA and protein levels at 0, 0.5, 1, 4 and 24h post-exposure, along with the highest inductions at 0.5h post-exposure for EGFR and COX-2 and at 4h post-exposure for EGF and ICAM-1. It was suggested that SO(2) derivatives could increase the expressions of EGF, EGFR, ICAM-1 and COX-2 on the transcription and translation levels in BEP2D cells, and result in mucus over-production and inflammation responses. This might be one of the possible mechanisms that SO(2) aggravates asthma disease.

Protein oxidation and DNA-protein crosslink induced by sulfur dioxide in lungs, livers, and hearts from mice.

In this article, protein oxidative damage and DNA-protein crosslinks (DPC) induced by sulfur dioxide (SO(2)) in lungs, livers, and hearts of mice were studied. The protein carbonyl (PCO) content was measured using spectrophotometric DNPH assay to reflect the degree of protein oxidative damage, and the DPC coefficient was measured by using a KCl-sodium dodecyl sulfate (SDS) assay to show the degree of DNA damage in lungs, livers, and hearts from mice exposed to SO(2) at various concentrations (0, 14, 28, and 56 mg-m(- 3)) for 6 h per day for 7 days. The results indicate that SO(2) caused an increase of PCO and DPC level in all organs tested from mice in a concentration-dependent manner. The concentration-response relationships in all organs tested of both female and male mice could be fitted well with monolinear regression equations. The adjusted coefficient R squared of all equations is more than 0.9. These results lead to a conclusion that SO(2) may cause an increase of protein oxidation damage and DNA-protein crosslinking in lungs, livers, and hearts from mice. The rank order of absolute increase in PCO contents and DPC coefficient in three organs from mice compared with controls was lung > liver > heart. Our results also indicated the regulation of PCO and that of DPC induced by SO(2) were conformed to each other; this implies that the protein oxidative damage may be associated with the emergence of DPC.