Airway epithelial overexpressed cathepsin K induces airway remodelling through epithelial-mesenchymal trophic unit activation in asthma.

BACKGROUND AND PURPOSE: Airway epithelial cells (AECs) regulate the activation of epithelial-mesenchymal trophic units (EMTUs) during airway remodelling through secretion of signalling mediators. However, the major trigger and the intrinsic pathogenesis of airway remodelling is still obscure. EXPERIMENTAL APPROACH: The differing expressed genes in airway epithelia related to airway remodelling were screened and verified by RNA-sequencing and signalling pathway analysis. Then, the effects of increased cathepsin K (CTSK) in airway epithelia on airway remodelling and EMTU activation were identified both in vitro and in vivo, and the molecular mechanism was elucidated in the EMTU model. The potential of CTSK as an an effective biomarker of airway remodelling was analysed in an asthma cohort of differing severity. Finally, an inhibitor of CTSK was administered for potential therapeutic intervention for airway remodelling in asthma. KEY RESULTS: The expression of CTSK in airway epithelia increased significantly along with the development of airway remodelling in a house dust mite (HDM)-stressed asthma model. Increased secretion of CTSK from airway epithelia induced the activation of EMTUs by activation of the PAR2-mediated pathway. Blockade of CTSK inhibited EMTU activation and alleviated airway remodelling as an effective intervention target of airway remodelling. CONCLUSION AND IMPLICATIONS: Increased expression of CTSK in airway epithelia is involved in the development of airway remodelling in asthma through EMTU activation, mediated partly through the PAR2-mediated signalling pathway. CTSK is a potential biomarker for airway remodelling, and may also be a useful intervention target for airway remodelling in asthma patients.

Misdiagnosis of primary mucosa-associated lymphoid tissue lymphoma of the pleura: case report and literature review.

Background: Mucosa-associated lymphoid tissue (MALT) lymphoma is an indolent B cell lymphoma. Its occurrence in the pleura is rare, with atypical clinical manifestations. MALT of the pleura is easily misdiagnosed. This is the first case report of pleural MALT lymphoma in China. Case Description: We report the case of a 54-year-old Chinese man with no notable medical history who complained of cough, sputum, and shortness of breath for 3 months. He had a positive purified protein derivative (PPD) test. An initial misdiagnosis of pleural tuberculosis was corrected, after 3 thoracoscopic biopsies and tests, to primary pleural MALT lymphoma. He received treatments of R-CHOP (rituximab, cyclophosphamide, epirubicin, vindesine and prednisolone) and traditional Chinese medicine. The patient was followed for 3 years until June 2022, with no obvious respiratory symptoms. Pleural MALT lymphoma is extremely rare, with only a few cases reported. This article describes our case, and includes an overview of 15 previously reported cases to summarize the characteristics, treatments, and prognosis of primary pleural MALT lymphoma. Conclusions: Pleural MALT lymphoma is rare, and a correct diagnosis depends on tissue biopsy, immunohistochemical staining, and detection of gene rearrangement. Thoracoscopy is important to diagnose this disease. Multiple thoracoscopic biopsies may be necessary.

A Risk Model Composed of Complete Blood Count, BRAF V600E and MAP2K1 Predicts Inferior Prognosis of Langerhans Cell Histiocytosis in Children.

BACKGROUND: In children, Langerhans cell histiocytosis (LCH), which is the most prevalent histiocytic disorder, exhibits a wide variety of manifestations and outcomes. There is no standard prognosis evaluation system for LCH. We investigated the combined predictive significance of complete blood counts (CBCs), BRAF V600E and MAP2K1 in childhood LCH. METHODS: A cohort of 71 childhood LCH patients was retrospectively studied. The prognosis predictive significance of platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), systemic inflammation response index (SIRI), systemic immune inflammation index (SII), BRAF V600E, and MAP2K1 were analyzed. RESULTS: Histiocyte Society (HS) classification of LCH patients was correlated with NLR, SIRI, and progression free survival (PFS), bone involvement was correlated with SIRI, liver involvement was correlated with NLR, SII, SIRI, and PFS, spleen involvement was correlated with SIRI, lung involvement was correlated with NLR and PFS, CNS involvement was correlated with PFS, while BRAF V600E was correlated with PLR, NLR, SIRI, SII, PFS, and OS (p <0.05). MAP2K1 was correlated with NLR, SIRI, PFS, and OS (p <0.05). Elevated NLR, PLR SIRI, and SII predicted inferior PFS and OS (p <0.05). PLR, NLE, SIRI, SII, BRAF V600E, and MAP2K1 were used to establish a risk model for stratifying the LCH patients into 3 different risk groups. Respective median PFS for low-, mediate-, and high-risk groups were not reached, 26, and 14 months (p <0.001), and all median OS were not reached (p <0.001). CONCLUSION: The risk model combined with CBCs, BRAF V600E, and MAP2K1 might be a promising prognostic system for LCH in children.

Combined Interventions for Severe Novel Coronavirus Disease (COVID-19): Experience from 350 Patients.

PURPOSE: To summarize the clinical features and effective therapy of severe COVID-19 patients. PATIENTS AND METHODS: In this retrospective, multicenter study, the medical records of COVID-19 patients in Hunan, from January 21, 2020 to February 19, 2020 were reviewed. RESULTS: Of the 350 COVID-19 patients, 13.7% were severe cases. On admission, compared with non-severe patients, more severe patients had a neutrophil/lymphocyte ratio > 3 (58.3% vs 33.8%, P=0.001), D-dimer > 1 mg/L (41.7% vs 13.6%, P<0.0001), higher level of CRP (39.1 mg/L, IQR18.1-75.9 vs 13.4 mg/L, IQR5.0-32.8, P<0.0001), and multiple pneumonia on CT (77.1% vs 18.2%, P<0.0001). All severe patients received oxygen support. 95.8% of them received antivirals, and the most frequent therapy was lopinavir and ritonavir plus human interferon-α2b. Moxifloxacin was used in 70.8% severe patients. The total dosage of methylprednisolone sodium succinate was 640 mg (IQR 360-960) in severe patients, and the duration of use was 8.5 days (IQR 6.8-11.3). The total dosage of immunoglobulin was 80 g (IQR, 60-140) in severe patients, and the duration was 8.0 days (IQR, 6.0-11.5). As of March 15, 2020, 95.8% of the severe patients had been discharged and only two deaths occurred. CONCLUSION: The rate of severe cases and mortality of COVID-19 in Hunan are lower than those in Wuhan. In addition to antivirals and oxygen support, timely interventions including corticosteroids, immunoglobulin, and antibiotics, contribute to improving the prognosis of severe COVID-19 patients.

Corticosteroid Use in the Treatment of COVID-19: A Multicenter Retrospective Study in Hunan, China.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has developed into a worldwide pandemic. This study aimed to retrospectively describe the use of corticosteroids in treating COVID-19. METHODS: For this multicenter retrospective study, medical records from 488 symptomatic COVID-19 patients were reviewed. Patients were divided into severe and nonsevere groups. Baseline characteristics, signs and symptoms, laboratory findings, treatments, and disease outcomes were compared. Specific data for corticosteroid treatment were further analyzed. RESULTS: Four hundred fifty COVID-19 patients were included in this study, including 82 severe patients and 368 nonsevere cases. Out of the 450 patients, 126 (28.0%) received corticosteroid treatment. In the 126 patients treated with corticosteroids, the median daily dose of corticosteroid therapy was 56.6 [interquartile range (IQR): 40.0-78.4] mg and median corticosteroid therapy duration was 5.0 (IQR: 3.0-7.0) days. Among nonsevere cases, patients treated with corticosteroids were significantly older in comparison with patients who did not receive corticosteroid treatment (p<0.01); the proportion of patients receiving antibiotic therapy in the corticosteroid group was significantly higher than that in the noncorticosteroid group (p<0.001); hospitalization length and duration of viral shedding were significantly longer in patients in the corticosteroid group than in the noncorticosteroid group after adjusting for age, sex, and comorbidities (p<0.05). In severe cases, patients treated with corticosteroids were significantly older and comorbidities at admission were significantly more common in patients receiving corticosteroid treatment (p<0.05); the proportion of patients receiving antibiotic therapy in the corticosteroid group was significantly higher than that in the noncorticosteroid group (p<0.001); no significant difference in hospitalization length or viral shedding duration was found between two groups after adjusting for age, sex, and comorbidities (p>0.05). CONCLUSION: Our study indicates that corticosteroids are regarded as one of treatments in the general clinical practice of COVID-19. However, corticosteroid use may be accompanied by increased use of antibiotics, longer hospitalization, and prolonged viral shedding.

Blood and Bronchoalveolar Lavage Fluid Metagenomic Next-Generation Sequencing in Pneumonia.

BACKGROUND: Metagenomic next-generation sequencing (mNGS) has made a revolution in the mode of pathogen identification. We decided to explore the diagnostic value of blood and bronchoalveolar lavage fluid (BALF) as mNGS samples in pneumonia. METHODS: We retrospectively reviewed 467 mNGS results and assessed the diagnostic performance of paired blood and BALF mNGS in 39 patients with pneumonia. RESULTS: For bacteria and fungi, 16 patients had culture-confirmed pathogen diagnosis, while 13 patients were culture-negative. BALF mNGS was more sensitive than blood mNGS (81.3% vs. 25.0%, p=0.003), and the specificity in BALF and blood mNGS was not statistically significant different (76.9% vs. 84.6%, p=0.317). For 10 patients without culture test, treatments were changed in 2 patients. For viruses, Epstein-Barr virus was positive in blood mNGS in 9 patients. Human adenovirus was detected in both BALF and blood mNGS in 3 patients. CONCLUSION: Our study suggests that BALF mNGS is more sensitive than blood mNGS in detecting bacteria and fungi, but blood also has advantages to identify the pathogens of pneumonia, especially for some viruses.

Airway epithelial integrin ß4 suppresses allergic inflammation by decreasing CCL17 production.

Airway epithelial cells (AECs) play a key role in asthma susceptibility and severity. Integrin ß4 (ITGB4) is a structural adhesion molecule that is down-regulated in the airway epithelium of asthma patients. Although a few studies hint toward the role of ITGB4 in asthmatic inflammation pathogenesis, their specific resultant effects remain unexplored. In the present study, we determined the role of ITGB4 of AECs in the regulation of Th2 response and identified the underpinning molecular mechanisms. We found that ITGB4 deficiency led to exaggerated lung inflammation and AHR with higher production of CCL17 in house dust mite (HDM)-treated mice. ITGB4 regulated CCL17 production in AECs through EGFR, ERK and NF-κB pathways. EFGR-antagonist treatment or the neutralization of CCL17 both inhibited exaggerated pathological marks in HDM-challenged ITGB4-deficient mice. Together, these results demonstrated the involvement of ITGB4 deficiency in the development of Th2 responses of allergic asthma by down-regulation of EGFR and CCL17 pathway in AECs.

Tracheobronchopathia osteochondroplastica: A case report and literature review. / éª¨åŒ–æ€§æ°”ç®¡æ”¯æ°”ç®¡ç— 1ä¾‹åŠæ–‡çŒ®å¤ä¹ .

Tracheobronchopathia osteochondroplastica (TBO) is a rare disease with unknown etiology characterized by ossifying nodules in the trachea and bronchial walls without involvement of the posterior wall of trachea. A 35-year-old woman admitted to Second Xiangya Hospital, Central South University, in August 2018 was diagnosed as TBO. She complained of dyspnea for over two years, worsening in autumn and winter, and was detected with tracheal ossification via bronchoscopy and biopsy. The patient received no special treatment, and no improvement or deterioration of symptoms was observed during the 3-month follow-up. We reviewed 60 TBO cases and found that 60% of them were female, with ages of 20-80 (53.62±15.97) years. The involved lesion sites were from the vocal cords to the bronchial segments, mainly in the trachea and bilateral main trachea, and the lower part of the trachea was more common. Combined respiratory symptoms were common. The diagnosis mainly depends on bronchoscopy and biopsy. Symptomatic treatment is the main strategy for symptomatic TBO patients, including endoscopic intervention and surgery. It is generally believed that the short-term prognosis of TBO is good, but the long-term prognosis still needs to be further studied.

Characteristic Electrocardiographic Manifestations in Patients With COVID-19.

Cardiac involvement has been reported in patients with COVID-19, which may be reflected by electrocardiographic (ECG) changes. Two COVID-19 cases in our report exhibited different ECG manifestations as the disease caused deterioration. The first case presented temporary SIQIIITIII morphology followed by reversible nearly complete atrioventricular block, and the second demonstrated ST-segment elevation accompanied by multifocal ventricular tachycardia. The underlying mechanisms of these ECG abnormalities in the severe stage of COVID-19 may be attributed to hypoxia and inflammatory damage incurred by the virus.

PKR suppress NLRP3-pyroptosis pathway in lipopolysaccharide-induced acute lung injury model of mice.

To explore the effect of double-stranded RNA-dependent kinase (PKR) in acute lung injury (ALI) and resultant acute respiratory distress syndrome (ARDS). A mouse model of lipopolysaccharide (LPS)-induced ALI was used to evaluate the levels of phosphorylated (p)-PKR and NLRP3 in lung tissue, and the protective effects of a PKR inhibitor on lung injury. And in vitro, macrophages were incubated with LPS, with or without PKR inhibitor pre-treatment. It was observed that the levels of p-PKR protein and NLRP3 protein were significantly increased compared with those in control tissues after LPS administration. Meanwhile, treatment with PKR inhibitor decreased inflammation, injury score, wet/dry weight ratio, bronchoalveolar lavage fluid (BALF) protein levels, neutrophil count in BALF, myeloperoxidase activity and expression of high-mobility group box1(HMGB1) and interleukin(IL)-1ß in the lungs of LPS-challenged mice. In vitro, we demonstrated that the levels of p-PKR and NLRP3, and cell mortality rate were increased in macrophages which were incubated with LPS compared with those without LPS administration, and PKR inhibitor significantly suppressed the level of NLRP3, caspase-1, HMGB1 and IL-1ß. These results indicate that PKR plays a key role in ALI through NLRP3-pyrotosis pathway and pharmacological inhibition of PKR may have potential therapeutic effects in the treatment of patients with ALI and ARDS.

Conventional Treatments plus Acupuncture for Asthma in Adults and Adolescent: A Systematic Review and Meta-Analysis.

OBJECTIVES: The efficacy of conventional treatments plus acupuncture for asthma in adult and adolescent is uncertain. Literature reports are conflicting; therefore, the aim of this study was to determine the efficacy of conventional treatments plus acupuncture versus conventional treatments alone using a meta-analysis of all published randomized clinical trials (RCTs). METHODS: Two reviewers independently performed a comprehensive literature search from multiple electronic sources (1990-2018), including PubMed, EMBASE, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, and WanFang databases. RCTs in which adult and adolescent patients with asthma (age ≥12 years) were divided into conventional treatments plus acupuncture and conventional treatments alone were included. RESULTS: Nine studies were included. The results showed that conventional treatments plus acupuncture as a complementary therapy could improve the symptom response rate (OR = 7.87, 95% CI = [4.13, 14.99], p < 0.00001) and significantly decrease interleukin-6 (IL-6) levels (MD = -11.42; 95% CI = [-15.28, -7.56], p < 0.00001). However, indices of pulmonary function, including the forced expiratory volume in one second (FEV1) (MD = 0.22, 95% CI = [-0.11, 0.56], p = 0.19) and FEV1/forced vital capacity (FVC) (MD = 8.62, 95% CI = [-0.35, 17.59], p = 0.06), failed to be improved with conventional treatments plus acupuncture. CONCLUSION: Conventional treatments plus acupuncture are associated with significant benefits for adult and adolescent patients with asthma. Therefore, we suggest the use of conventional treatments plus acupuncture for asthma patients.

Redistribution of adrenomedullary nicotinic acetylcholine receptor subunits and the effect on circulating epinephrine levels in a murine model of acute asthma.

The lack of circulating epinephrine (EPI) in the pathogenesis of asthma has long been attributed to the lack of adrenergic nerves in human airways. However, in this study we considered that EPI levels are regulated by EPI release in addition to synthesis. Nicotinic acetylcholine receptors (nAChRs) have been shown to control EPI release, and we hypothesized that redistribution of nAChR subunits modulates EPI release and circulating EPI levels. Using a mouse model of asthma, circulating EPI levels were measured by enzyme-linked immunosorbent assays. Changes in the expression of nAChR subunits in the adrenal medulla were observed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Expression of phenylethanolamine N-methyltransferase, tyrosine hydroxylase and galanin was detected by RT-qPCR. Lung pathology, airway resistance (RL) and EPI levels were also assessed after treatment with an α7 nAChR agonist or antagonist. α7 nAChR mRNA expression in the adrenal medulla was increased by more than 2-fold (P<0.05), and circulating EPI levels increased rapidly after treatment with the α7 nAChR agonist. These results indicated that increased EPI release, which was caused by the overexpression of α7 nAChR, was responsible for elevated circulating EPI levels. After treatment with an agonist of α7 nAChR, RL was significantly decreased. Serum corticosterone levels in individual mice were measured to rule out glucocorticoid as the main mediator of changes in EPI levels. On the whole, redistribution of nAChR subunits, primarily α7 nAChR, occurs in the adrenal medulla in asthmatic mice. Increased α7 nAChR expression can rapidly increase serum EPI levels and decrease airway responsiveness.

Interferon Regulatory Factor-1 Mediates Alveolar Macrophage Pyroptosis During LPS-Induced Acute Lung Injury in Mice.

Previously, we demonstrated that pyroptosis in alveolar macrophages (AMs) plays an essential role in lipopolysaccharide (LPS)-induced acute lung injury. However, the underlying mechanism remains largely unclear. Here, we show that the absence of interferon regulatory factor 1 (IRF-1) in genetic knock-out mice strongly abrogates pyroptosis in AMs and alleviates the LPS-induced lung injury and systemic inflammation. Our study demonstrates that IRF-1 contributes to caspase-1 activation and apoptosis-associated speck-like protein containing a caspase activation and recruitment domain pyroptosome formation in AMs and leads to downstream inflammatory cytokine release, including that of IL-1ß, IL-18, and HMGB1. The nuclear translocation of IRF-1 is linked to the presence of toll-like receptor 4 (TLR4). Our findings suggest that pyroptosis and the downstream inflammatory response in AMs induced by LPS is a process that is dependent on TLR4-mediated up-regulation of IRF-1. In summary, IRF-1 plays a key role in controlling caspase-1-dependent pyroptosis and inflammation.

Lung dendritic cells undergo maturation and polarization towards a T helper type 2-stimulating phenotype in a mouse model of asthma: Role of nerve growth factor.

Nerve growth factor (NGF) and dendritic cells (DCs) have been hypothesized to modulate T cell responses in a mouse model of asthma. However, whether NGF plays a role in regulating the maturation and polarization of lung DCs remains unclear. In the present study, the effect of NGF inhibition on the maturation and phenotype of lung DCs was investigated in a mouse model of asthma. BALB/c mice were sensitized and challenged with ovalbumin (OVA), and subsequently received anti-NGF treatment. At 24 h following the last challenge, airway responsiveness and inflammation were examined. The concentrations of NGF, interferon (IFN)-γ and interleukin (IL)-4 were analyzed. In addition, maturation and CD103 expression in the lung DCs were investigated. Anti-NGF treatment was found to significantly reduce airway hyperreactivity and inflammation in asthmatic mice. In addition, a subdued T helper 2 (Th2) response was observed, characterized by the downregulation of IL-4 and the upregulation of IFN-γ. Furthermore, the expression of the DC surface molecules, CD80, CD86 and major histocompatibility complex class II, as well as the proportion of lung CD103+ DCs, decreased in the OVA-sensitized and challenged mice. The proportion of lung CD103+ DCs also exhibited a positive correlation with the levels of plasma NGF in the mice. These results may provide an explanation for the role of NGF in amplifying the Th2 response in allergic diseases. Therefore, NGF may promote the maturation and polarization towards a Th2-stimulating phenotype of activated DCs, contributing to an amplification of the Th2 response in asthma.

Low-intensity aerobic exercise mitigates exercise-induced bronchoconstriction by improving the function of adrenal medullary chromaffin cells in asthmatic rats.

Exercise is one of the most common triggers of bronchoconstriction in patients with asthma. The low levels of circulating epinephrine produced by the adrenal medullary chromaffin cells (AMCCs) are associated with exercise-induced bronchoconstriction (EIB) in asthmatics. In the present study, we tested the hypothesis that low-intensity aerobic exercise may ameliorate EIB using a rat model of asthma. Male Sprague-Dawley rats at 7 weeks of age, sensitized with ovalbumin or treated with saline, were subjected to low or moderate exercise training (50 or 75% of maximum velocity) for one hour in a treadmill 30 min after ovalbumin or saline inhalation. The exercise capacity, airway responsiveness, lung morphology, the morphological changes and endocrine function of AMCCs were measured in both groups of rats after exercise training for 6 weeks. Either low-intensity or moderate-intensity exercise mitigated EIB and increased exercise capacity in ovalbumin-sensitized (asthmatic) rats. Low-intensity aerobic exercise reduced the vacuolar degeneration degrees, lipid contents, neuronal peripherin and neurofilament-68 expression, demolished neurites, but increased the chromaffin granule density, endocrine chromogranin A and phenylethanolamine N-methyltransferase expression in the adrenal medullary tissues, accompanied by increased levels of circulating epinephrine and corticosterone, but decreased nerve growth factor in asthmatic rats. Finally, low-intensity aerobic exercise significantly reduced the relative levels of phosphorylated extracellular signal-regulated kinase and phosphorylated cAMP responsive element-binding protein and the relative mRNA expression levels of downstream molecules, including c-FOS and c-JUN in the adrenal medullary of asthmatic rats. We suggest that low-intensity aerobic exercise improves the endocrine dysfunction of AMCCs and mitigates EIB.

Low-intensity aerobic exercise training attenuates airway inflammation and remodeling in a rat model of steroid-resistant asthma.

BACKGROUND: Aerobic exercise can improve symptoms, reduce airway inflammation, and even ameliorate airway remodeling in asthmatic animals and patients. However, previous studies have focused mainly on the effect of aerobic exercise on steroid-sensitive asthma (SSA). The goals of this study were to determine the effect of low-intensity aerobic exercise training on airway hyperresponsiveness, inflammation, and remodeling in a rat model of steroid-resistant asthma (SRA) and to identify the potential mechanisms underlying these effects. METHODS: Endotoxin-free ovalbumin with or without lipopolysaccharide were applied to establish rat models of SRA and SSA, respectively. Airway hyperresponsiveness, inflammation, remodeling, expression of interleukin (IL)-25, IL-33, thymic stromal lymphopoietin (TSLP), high mobility group box-1 (HMGB1), and IL-17 in bronchoalveolar lavage fluid (BALF), and the role of dexamethasone (DXM) were compared between these two asthmatic rat models. The effect of low-intensity aerobic exercise training and anti-HMGB1 treatment on airway hyperresponsiveness, inflammation, and remodeling in SRA rats also was evaluated. RESULTS: SRA rats developed neutrophil-dominated airway inflammation ((29.5±4.1)% of the total cell numbers in BALF), whereas SSA rats developed eosinophil-dominated airway inflammation ((24.0±6.1)% of the total cell numbers in BALF). Compared with SSA rats, SRA rats had more severe airway hyperresponsiveness, lower levels of IL-25 ((33.6±10.3) vs. (104.8±24.9) pg/ml), IL-33 ((87.5±25.0) vs. (226.6±40.7) pg/ml), and TSLP ((1 933.2±899.5) vs. (7 224.0±992.1) pg/ml), and higher levels of HMGB1 ((21.2±4.5) vs. (5.4±1.6) ng/ml) and IL-17 ((780.5±261.7) vs. (291.4±76.4) pg/ml) in BALF (all P < 0.05). However, there was no significant difference in goblet cell hyperplasia, subepithelial collagen thickness, and airway smooth muscle remodeling between the two groups. Compared with control SSA rats, airway hyperresponsiveness, inflammation, and remodeling in SRA rats were less sensitive to DXM treatment. Anti-HMGB1 treatment attenuated airway hyperresponsiveness, inflammation, and remodeling in SRA rats to a certain extent and was accompanied by lower levels of IL-17 ((369.2±126.7) vs. (780.5±261.7) pg/ml in control SRA rats) in BALF (P < 0.05). Low-intensity aerobic exercise training decreased the expression of both HMGB1 ((14.1±2.9) vs. (21.2±4.5) ng/ml in control SRA rats) and IL-17 ((545.3±148.6) vs. (780.5±261.7) pg/ml in control SRA rats) in BALF (all P < 0.05) and was accompanied by improved airway hyperresponsiveness, inflammation, and remodeling in SRA rats (all P < 0.05). CONCLUSIONS: Low-intensity aerobic exercise training attenuated airway hyperresponsiveness, inflammation, and remodeling in a rat model of SRA. Decreased HMGB1 and IL-17 levels in BALF by aerobic exercise training at least partly contributed to the improvements of SRA.

High-intensity training induces EIB in rats through neuron transdifferentiation of adrenal medulla chromaffin cells.

A high prevalence of exercise-induced bronchoconstriction (EIB) can be found in elite athletes, but the underlying mechanisms remain elusive. Airway responsiveness, NGF and epinephrine (EPI) levels, and chromaffin cell structure in high- (HiTr) and moderate-intensity training (MoTr) rats with or without ovalbumin (OVA) sensitization were measured in a total of 120 male Sprague-Dawley rats. The expression of NGF-associated genes in rat adrenal medulla was tested. Both HiTr and OVA intervention significantly increased airway resistance to aerosolized methacholine measured by whole body plethysmography. HiTr significantly increased inflammatory reaction in the lung with a major increase in peribronchial lymphocyte infiltration, whereas OVA significantly increased the infiltration of various inflammatory cells with an over 10-fold increase in eosinophil level in bronchoalveolar lavage. Both HiTr and OVA intervention upregulated circulating NGF level and peripherin level in adrenal medulla, but downregulated phenylethanolamine N-methyl transferase level in adrenal medulla and circulating EPI level. HiTr + OVA and HiTr + ExhEx (exhaustive exercise) interventions significantly enhanced most of the HiTr effects. The elevated NGF level was significantly associated with neuronal conversion of adrenal medulla chromaffin cells (AMCC). The levels of p-Erk1/2, JMJD3, and Mash1 were significantly increased, but the levels of p-p38 and p-JNK were significantly decreased in adrenal medulla in HiTr and OVA rats. Injection of NGF antiserum and moderate-intensity training reversed these changes observed in HiTr and/or OVA rats. Our study suggests that NGF may play a vital role in the pathogenesis of EIB by inducing neuron transdifferentiation of AMCC via MAPK pathways and subsequently decreasing circulating EPI.

[Transcription factors in spinal dorsal root ganglion in rats recurrently infected with respiratory syncytial virus].

OBJECTIVE: To elucidate intracellular transcription factor activation of C(7) approximately T(5) dorsal root ganglia in rats recurrently infected with respiratory syncytial virus (RSV). METHODS: Eighty 1 approximately 2 weeks old Sprague-Dawley rats were randomly divided into 2 groups: a control group and a RSV-infection group. The rats in the RSV-infection group were infected with 5 x 10(5) U/mL RSV once a week and the rats in the control group were treated with culture medium without RSV. Airway response was measured after 8 weeks. Lung tissue was submitted for HE staining and in situ hybridization. The C(7) approximately T(5) dorsal root ganglia were obtained for the preliminary screening of the intracellular transcription factors by TranSignal protein/DNA combo array. Nuclear protein of C(7) approximately T(5) dorsal root ganglia were extracted and submitted to Western blot. RESULTS: Airway response in the RSV-infection group was higher than that in the control group (P<0.05). HE staining showed inflammatory cell infiltration, and in situ hybridization demonstrated positive RSV RNA in the RSV-infection rat lung which was not present in the control group, thus validating the efficacy of our model. TranSignal protein/DNA combo array screening showed that 55 transcription factors increased by at least 2 folds in the C(7) approximately T(5) DRG cells of the RSV-infection group. The transcription factors Smad and interferon regulatory factor (1 or 2) were the 2 most upregulated transcription factors identified by combo array screening (59 and 43 fold increase compared with the control, respectively). Western blot confirmed Smad(1/2/3) and IRF-1 upregulate while IRF-2 remained unchanged. CONCLUSION: Respiratory syncytial virus infection results in airway hyperresponsiveness and transcription factor activation in C(7) approximately T(5) spinal adorsal root ganglia in rats, which may contribute to airway nerve network dysfunction and airway hyperresponsiveness.