Functional characterization of two novel NKX2-1 frameshift variants that cause pulmonary surfactant dysfunction.

BACKGROUND: We aim to report two unrelated patients with pulmonary surfactant dysfunction (PSD) that carried two novel NKX2-1 frameshift variants, and evaluated the impact of these variants in vitro. METHODS: We enrolled children with PSD and NKX2-1 variants, and collected their clinical information and follow-up data. We constructed wild-type (WT) and variant NKX2-1 plasmids and transfected them into A549 and HEK293T cells. The functional characterization of variants was then evaluated by qRT-PCR, western blot, immunofluorescence, electrophoretic mobility shift assay, and dual-luciferase reporter assay. RESULTS: Two novel heterozygous frameshift variants of NKX2-1, i.e., c.705delC (Gly236Alafs*29) and c.313_316 dup (Asn106Lysfs*304), were identified in children from two unrelated families. We discerned attenuated mRNA and protein expression in the Asn106Lysfs*304 variant, and reduced DNA -binding as well as transcriptional activation capabilities in both variants. While the Asn106Lysfs*304 variant lost its synergistic interactions with PAX8 and TAZ, the Gly236Alafs*29 variant partially retained its residual transcriptional activation capabilities and synergistic interactions with PAX8 and TAZ. CONCLUSIONS: We reported on two children with two novel NKX2-1 frameshift variants. In vitro experiments revealed that the two frameshift variants have common and different mechanisms based on the loss or conservation of domains, which partially explained the phenotypical heterogeneity. IMPACT: Pulmonary surfactant dysfunction is a rare heterogeneous disease that exhibits a great burden on children's quality of life. We reported two novel NKX2-1 frameshift variants carried by two children with different clinical phenotypes, thus broadening our knowledge base of gene variations and phenotypes in NKX2-1. We performed an in vitro study and uncovered different pathogenic mechanisms underlying the actions of two novel variants, and thereby partially explained the mechanisms of phenotypical heterogeneity caused by NKX2-1 variants.

circS100A11 enhances M2a macrophage activation and lung inflammation in children with asthma.

BACKGROUND: Dysregulation of circRNAs is associated with a variety of human diseases; however, its role in childhood asthma is undefined. METHODS: The differential expression profiles of circRNAs were analyzed by microarray. The effects and mechanisms by which circRNAs influence macrophage activation were detected by quantitative real-time PCR, RNA immunoprecipitation assay, and chromatin immunoprecipitation assay, among others. The roles of circRNA and its host gene in asthma were tested in a cockroach allergen extract (CRE)-induced murine asthma model. RESULTS: We identified 372 circRNAs that were differentially expressed in PBMCs of children with asthma as compared with healthy controls. A circRNA with unknown function, circS100A11, was dominantly expressed in monocytes and significantly upregulated in children with asthma. circS100A11 facilitated M2a macrophage activation by enhancing translation of its host gene, S100A11, and exacerbated lung inflammation in a CRE-induced murine asthma model with macrophage-specific overexpression of circS100A11. Mechanistically, circS100A11 promoted S100A11 translation by competitively binding to CAPRIN1 to decrease the suppression of CAPRIN1 upon S100A11 translation. Then, S100A11 liberated SP3 from nucleolin and promoted SP3 binding to the STAT6 promoter to enhance STAT6 expression and M2a macrophage activation. Macrophage-specific knockdown of S100A11 could alleviate lung inflammation in a CRE-induced murine asthma model in vivo. CONCLUSIONS: circS100A11 and S100A11 promote M2a macrophage activation and lung inflammation in asthma model and may serve as potential therapeutic and diagnostic targets in children with asthma.

[Congenital pulmonary alveolar proteinosis in a neonate]. / æ–°ç”Ÿå„¿å ˆå¤©æ€§è‚ºæ³¡è›‹ç™½æ²‰ç§¯ç—‡1例.

The male patient was referred to the hospital at 44 days old due to dyspnea after birth and inability to wean off oxygen. His brother died three days after birth due to respiratory failure. The main symptoms observed were respiratory failure, dyspnea, and hypoxemia. A chest CT scan revealed characteristic reduced opacity in both lungs with a "crazy-paving" appearance. The bronchoalveolar lavage fluid (BALF) showed periodic acid-Schiff positive proteinaceous deposits. Genetic testing indicated a compound heterozygous mutation in the ABCA3 gene. The diagnosis for the infant was congenital pulmonary alveolar proteinosis (PAP). Congenital PAP is a significant cause of challenging-to-treat respiratory failure in full-term infants. Therefore, congenital PAP should be considered in infants experiencing persistently difficult-to-treat dyspnea shortly after birth. Early utilization of chest CT scans, BALF pathological examination, and genetic testing may aid in early diagnosis.

Size-segregated particle number concentrations and outpatient-department visits for pediatric respiratory diseases in Shanghai, China.

BACKGROUND: Few studies have simultaneously explored which size of particles has the greatest impact on the risk for pediatric asthma, bronchitis and upper respiratory tract infections (URTIs). OBJECTIVES: To investigate the short-term association between size-segregated particle number concentrations (PNCs) and outpatient-department visits (ODVs) for major pediatric respiratory diseases. METHODS: Daily counts of pediatric ODVs for asthma, bronchitis and URTIs were obtained from 66 hospitals in Shanghai, China, from 2016 to 2018. Pollutant effects were estimated using Poisson generalized additive models combined with polynomial distributed lag models. We also fitted co-pollutant cumulative effects models included six criteria air pollutants and conducted stratifying analyses by gender, age, season and geographic distances. RESULTS: We identified a total of 430,103 patients with asthma, 1,547,013 patients with bronchitis, and 2,155,738 patients with URTIs from the hospitals. Effect estimates increased with decreasing particle size. Ultrafine particle (UFP) and PNCs of 0.10-0.40 µm particles (PNC0.10-0.40) were associated with increased ODVs for asthma, bronchitis and URTIs at cumulative lags up to 3d. Associations tended to appear stable after adjusting for criteria air pollutants. At the cumulative lag 0-2d, each interquartile range increase in UFP was associated with increased ODVs due to asthma (relative risk 1.21, 95% CI: 1.07, 1.38), bronchitis (1.20, 95% CI: 1.07, 1.34) and URTI (1.17, 95% CI: 1.06, 1.30), whereas the associations for PNC0.10-0.40 remained significant but attenuated in magnitude. CONCLUSIONS: UFP may be a leading contributor to the adverse respiratory effects of particulate air pollution and the effects increased with decreasing particle size.

lnc-BAZ2B promotes M2 macrophage activation and inflammation in children with asthma through stabilizing BAZ2B pre-mRNA.

BACKGROUND: Dysregulation of long noncoding RNAs (lncRNAs) is associated with a variety of human diseases; however, whether they have a role in childhood asthma is unknown. OBJECTIVE: We sought to determine the differential expression profiles of lncRNAs in PBMCs of children with asthma and the mechanisms underlying the effects of lncRNAs on the pathogenesis of asthma. METHODS: The differential expression profiles of lncRNAs were analyzed by transcriptome microarray. The effects and mechanisms by which lncRNAs influence macrophage activation were detected by real-time quantitative PCR, Western blot, RNase protection assay, and chromatin immunoprecipitation assay. The roles played by lncRNAs in asthma were tested in a cockroach allergen extract (CRE)-induced mouse model. RESULTS: We identified 719 lncRNAs that were differentially expressed in PBMCs of children with asthma, 502 of which were upregulated and 217 were downregulated. An lncRNA of unknown function, lnc-BAZ2B, was dominantly expressed in monocytes and significantly upregulated in children with asthma. lnc-BAZ2B promotes M2 macrophage activation by enhancing BAZ2B expression and exacerbated lung inflammation in an M2 macrophage-associated CRE-induced asthma model. Mechanistically, lnc-BAZ2B promoted the expression of its cis target gene BAZ2B by stabilizing its pre-mRNA. BAZ2B, a reader of H3K14ac modification, enhanced the transcription of IRF4 and promoted M2 macrophage activation. lnc-BAZ2B expression was correlated with that of BAZ2B in PBMCs from children with asthma. Baz2b knockdown could alleviate asthma severity in a CRE-induced asthma model. CONCLUSION: lnc-BAZ2B promotes M2 macrophage activation and inflammation in children with asthma and may serve as a potential therapeutic and diagnostic target in children with asthma.

Diagnostic and clinical utility of next-generation sequencing in children born with multiple congenital anomalies in the China neonatal genomes project.

Multiple congenital anomalies (MCAs) at birth have emerged as an important cause of neonatal morbidity and mortality. This study aimed to investigate the genetic causes and characteristics of clinical outcomes in a large cohort of neonates with MCAs. Clinical exome sequencing/exome sequencing/genome sequencing were undertaken from December 1, 2016 to December 1, 2019 to detect single nucleotide variations (SNVs) and copy number variations (CNVs) simultaneously in individuals who met the inclusion criteria. A total of 588 neonates with MCAs were enrolled. One hundred sixty-one patients received diagnosis, with 71 CNVs and 90 SNVs detected, the overall diagnostic rate being 27.38%. Cardiovascular malformation was the most common anomaly (60%) and accounted for the top symptomatic proportion in both CNVs and SNVs. As the number of involved system increased from 2 to 3-4, and then to ≥5, the overall diagnostic rate increased gradually from 23.1% to 30.5%, and then to 52.2%, respectively. Patients who received genetic diagnoses were offered better clinical management or were referred to the specific disease clinic. In conclusion, this large cohort study demonstrates that both CNVs and SNVs contribute to the genetic causes of MCAs, and earlier genetic assertion may lead to better clinical management for patients.

Respiratory symptoms as initial manifestations of interstitial lung disease in clinically amyopathic juvenile dermatomyositis: a case report with literature review.

BACKGROUND: Clinically amyopathic juvenile dermatomyositis (CAJDM) is a clinical subgroup of juvenile dermatomyositis (JDM), characterized by JDM rashes with little or no clinically evident muscle weakness. Interstitial lung disease (ILD) is an uncommon but potentially fatal complication of juvenile dermatomyositis (JDM). While adults with dermatomyositis-associated ILD usually present respiratory symptoms before or at the same time as skin muscle manifestations, only a few studies have covered the onset of respiratory symptoms of ILD in JDM patients, especially CAJDM. There is currently no clear effective treatment regime or any prognostic factors for CAJDM-associated ILD. CASE PRESENTATION: Here, we report the first case of a CAJDM patient who presented with respiratory symptoms as the initial manifestation. A 10-year-old male patient presented to the hospital with a complaint of progressive cough and chest pain. Violaceous macule and papules appeared a few days later and he was positive for anti-Ro-52 antibodies. Imaging showed diffuse interstitial infiltration in both lungs and lung function tests showed restrictive and obstructive ventilatory dysfunction. Muscular abnormalities were excluded by thigh magnetic resonance imaging (MRI) and electromyography. Skin biopsy showed pathognomonic findings consistent with DM. Lung biopsy indicated chronic inflammation of the mucosa. This patient was finally diagnosed with CAJDM complicated by ILD and prescribed methylprednisolone, immunoglobulin, prednisolone and mycophenolate mofetil (MMF) for treatment. The patient's cutaneous and respiratory manifestations were largely improved. We retrospectively reviewed this and another six cases with CAJDM-associated ILD reported previously to better understand its clinical characteristics and effective management. CONCLUSIONS: Initial respiratory symptoms with rapid progression in patients presenting Gottron papules should be considered manifestations of CAJDM-associated ILD. We also found a combination of corticosteroids, IVIG and MMF to be an effective method of arresting the progress of CAJDM-associated ILD and improving the prognosis of the patients.

Characteristics of childhood allergic diseases in outpatient and emergency departments in Shanghai, China, 2016-2018: a multicenter, retrospective study.

BACKGROUND: The prevalence of allergic diseases (ADs), such as asthma and allergic rhinitis (AR), is increasing worldwide in both adults and children. Although ADs are common and frequently coexist in outpatient care, city-level data regarding the characteristics of childhood AD remain limited in China. This study aimed to assess the profile and characteristics of ADs in the city of Shanghai. METHODS: A multicenter retrospective study was designed to collect routine administrative data from outpatient and emergency departments from 66 hospitals in Shanghai, China, from 2016 to 2018. Children with asthma, AR, allergic conjunctivitis (AC), and allergic skin diseases were investigated. Demographic characteristics, patients visit pattern, spectrum of diagnosis, and comorbidities were analyzed. RESULTS: A total of 2,376,150 outpatient and emergency visits for ADs were included in the period from 2016 to 2018. Allergic skin diseases accounted for 38.9%, followed by asthma (34.8%), AR (22.9%), and AC (3.3%), with a male predominance in all four diseases. Asthma and allergic skin diseases were most frequent in the 1 to < 4 years of age group, while AR and AC were more common in the 4 to < 7 years of age group. Asthma accounted for the greatest number of annual and emergency visits. The most frequent comorbidity of asthma was lower respiratory tract infection (LRTI) (49.3%), followed by AR (20.5%) and upper respiratory tract infection (14.1%). The most common comorbidities of AR were otitis media (23.4%), adenoid hypertrophy/obstructive sleep apnea (22.1%), followed by LRTI (12.1%), asthma (9.4%) and chronic pharyngitis (8.9%). CONCLUSIONS: Asthma and allergic skin diseases were the most common ADs in outpatient and emergency departments in the study period. Respiratory tract infection was the most common comorbidity of asthma in children. More attention should be devoted to the treatment of comorbidities to improve childhood AD outcomes with a better understanding of the characteristics of ADs in outpatient care.

Temperature changes between neighboring days and childhood asthma: a seasonal analysis in Shanghai, China.

Few evidences are available about the impact of temperature variation on childhood asthma in different seasons. This study aimed to assess the influence of temperature changes between neighboring days (TCN) on the exacerbation of asthma among children. Daily outpatient visits for childhood asthma (DOVCA) were collected from 17 main hospitals in Shanghai, China, from 2016 to 2018. A quasi-Poisson regression combined with distributed lagged nonlinear models was employed to estimate the association between TCN and asthma visits in cool or warm seasons, after controlling for short- and long-term trends, day of week, holidays, daily mean temperature, daily mean relative humidity, and air pollutants. The TCN varied from - 9.6 to 6.7 °C. The relationship between TCN and DOVCA greatly varied by season. In warm seasons, positive TCN (temperature rise) was associated with higher risks of asthma outpatient visits and negative TCN (temperature drop) was associated with lower risks; the associations were present on lag 1 day and lasted for 2 weeks; the cumulative relative risk of childhood asthma over 0 to 14 days was 1.98 (95% confidence interval: 1.42, 2.76) and 0.31 (95% confidence intervals: 0.21, 0.44) comparing a TCN of 2.5 °C (5th percentile) and - 3.2 °C (95th percentile) with 0 °C, respectively. In cool seasons, neither negative nor positive TCN showed significant risks. In conclusion, temperature rise might increase the risk of childhood asthma exacerbation and temperature drop might decrease the risks in warm seasons. There were no statistically significant influences in cool seasons.

Erythropoietin prevents necrotizing enterocolitis in very preterm infants: a randomized controlled trial.

BACKGROUND: Necrotizing enterocolitis (NEC) is one of the most severe complications in very preterm infants, but there are currently no accepted methods to prevent NEC. Studies have shown that erythropoietin (EPO) has the potential to prevent NEC or improve outcomes of preterm NEC. This study aimed to determine whether recombinant human EPO (rhEPO) could protect against NEC in very preterm infants. METHODS: The study was a prospective randomized clinical trial performed among four NICU centers. A total of 1327 preterm infants with gestational age ≤ 32 weeks were admitted to the centers, and 42 infants were excluded leaving 1285 eligible infants to be randomized to the rhEPO or control group. Infants in the rhEPO group were given 500 IU/kg rhEPO intravenously every other day for 2 weeks, while the control group was given the same volume of saline. The primary outcome was the incidence of NEC in very preterm infants at 36 weeks of corrected gestational age. RESULTS: A total of 1285 infants were analyzed at 36 weeks of corrected age for the incidence of NEC. rhEPO treatment significantly decreased the incidence of NEC (stage I, II and III) (12.0% vs. 17.1%, p = 0.010), especially confirmed NEC (stage II and III) (3.0% vs. 5.4%, p = 0.027). Meanwhile, rhEPO treatment significantly reduced the number of red blood cells transfusion in the confirmed NEC cases (1.2 ± 0.4 vs. 2.7 ± 1.0, p = 0.004). Subgroup analyses showed that rhEPO treatment significantly decreased the incidence of confirmed NEC at gestational age < 28 weeks (p = 0.019), and the incidence of all stages NEC in preterm infants with hemoglobin < 90 g/l (p = 0.000) and 5 min Apgar score > 5 (p = 0.028). CONCLUSION: Repeated low-dose rhEPO treatment is beneficial against NEC in very preterm infants. Trial registration The protocol was registered retrospectively at ClinicalTrials.gov (NCT03919500) on April 18, 2019. https://clinicaltrials.gov/ct2/show/NCT03919500.

Clinical and Genetic Spectrum of Children with Primary Ciliary Dyskinesia in China.

OBJECTIVE: To report detailed knowledge about the clinical manifestations, ciliary phenotypes, genetic spectrum as well as phenotype/genotype correlation in primary ciliary dyskinesia (PCD) in Chinese children. STUDY DESIGN: We recruited 50 Chinese children with PCD. Extensive clinical assessments, nasal nitric oxide, high-speed video analysis, transmission electron microscopy, and genetic testing were performed to characterize the phenotypes and genotypes of these patients. RESULTS: Common clinical features included chronic wet cough (85.4%), laterality defects (70.0%), and neonatal respiratory distress (55.8%). A high prevalence of congenital abnormalities (30.2%, 13/43), observed in patients who underwent comprehensive examination for comorbidities, included thoracic deformity (11.6%, 5/43), congenital heart disease (9.3%, 4/43), and sensorineural deafness (2.3%, 1/43). For 24 children age >6 years, the mean predicted values of forced expiratory volume in 1 second were 87.2%. Bronchiectasis evident on high-resolution computed tomography was reported in 38.1% of patients (16/42). Biallelic mutations (81 total; 57 novel) were identified in 13 genes: DNAAF3, DNAAF1, DNAH5, DNAH11, CCDC39, CCDC40, CCDC114, CCDC103, HYDIN, CCNO, DNAI1, OFD1, and SPAG1. Overall, ciliary ultrastructural and beat pattern correlated well with the genotype. However, variable phenotypes were also observed in CCDC39 and DNAH5 mutant cilia. CONCLUSIONS: This large PCD cohort in China broadens the clinical, ciliary phenotypes, and genetic characteristics of children with PCD. Our findings are roughly consistent with previous studies besides some peculiarities such as high prevalence of associated abnormalities.

Clinical and genetic analysis of patients with primary ciliary dyskinesia caused by novel DNAAF3 mutations.

Primary ciliary dyskinesia (PCD) is a rare phenotypically and genetically heterogeneous disorder resulting from abnormal cilia ultrastructure and function. Few studies have reported the phenotype and genetic characteristics of PCD caused by mutations in DNAAF3. In this study, four PCD patients with DNAAF3 mutations underwent extensive clinical assessments, cilia ultrastructural and motion evaluations. All patients presented with situs inversus totalis, neonatal respiratory distress, and sinusitis; however, they did not have recurrent infections of the lower airways. The nasal nitric oxide level of these patients was markedly reduced. The respiratory cilia were found to be uniformly immotile, with their dynein arms defects. A total of 7 (5 novel) variants in DNAAF3 were identified and cosegregated in their families by Trio-based whole-exome sequencing. As the first report on DNAAF3 mutations in PCD patients in China, our study not only contributes to a deeper appreciation of the phenotypic characteristics of patients with DNAAF3 mutations but also expands the spectrum of DNAAF3 mutations and may contribute to the genetic diagnosis of and counseling for PCD.

Clinical features and molecular genetic analysis of thanatophoric dysplasia type I in a neonate with a de novo c.2419 T > C (p. Ter807Arg) (X807R) mutation in FGFR3.

We present a case report that entails prenatal ultrasonography, postnatal characteristics, and molecular genetic analysis of a newborn who presented with thanatophoric dysplasia type I (TDI) with a mutation in the fibroblast growth factor receptor 3 gene (FGFR3). A malformed newborn with tachypnea, delivered by caesarean at the gestational age of 39 weeks, was the first child of nonconsanguineous parents by a spontaneous pregnancy. Features in prenatal ultrasonography and postnatal radiography were consistent with the diagnosis of TDI, presenting with short body length (38 cm, <3rd percentile), redundant skin folds, a narrow thorax with a bust of 29.5 cm (3-5th percentile), and macrocephaly with a head circumference of 36 cm (>97th percentile). The proposita had postnatal dyspnea and unfortunately died of respiratory failure at the age of 13 days. Molecular genetic analysis revealed a mutation of c.2419 T > C (p. Ter807Arg) (X807R) in FGFR3. Live-born infants with TDI are exceedingly rare, and we hereby report a newborn with a c.2419 T > C mutation in FGFR3, emphasizing phenotype with clinical characteristics and ultrasonographic and X-ray findings, to raise awareness about the heterogeneous patterns of TD.

A novel surfactant protein C mutation resulting in aberrant protein processing and altered subcellular localization causes infantile interstitial lung disease.

BACKGROUND: Mutations in the surfactant protein C gene (SFTPC) result in interstitial lung disease (ILD). Our objective was to report a novel SFTPC mutation and evaluate the effect of this mutant on protein synthesis and processing. METHODS: Genomic DNA was extracted from whole blood of a Chinese infant with ILD and candidate genes associated with ILD were sequenced by next-generation sequencing. Subclones of wild-type and mutant SFTPC were transiently transfected into A549 cells. The functional characterization of mutant surfactant protein C (SP-C) was evaluated by Western blotting, transmission electron microscopy, and immunofluorescence. RESULTS: A novel heterozygous mutation SFTPC: c.337T>T/C, p.Y113H was identified in this ILD infant. Neither of the parents carries this mutation. Using A549 cells expressing wild-type and mutant SP-C isoforms, Western blotting revealed a significant reduction of proSP-C and a band with abnormal molecular weight in the mutant SP-C compared to the wild-type. Ultrastructural analysis showed abnormal cytoplasmic organelles. Immunofluorescence demonstrated mutant SP-C was scarcely trafficked to lamellar bodies but localized well to early endosomes, which was in marked contrast to the wild type protein. CONCLUSION: We detected a novel mutation in SFTPC causing ILD in infancy. The mutation results in aberrant proSP-C processing and altered subcellular localization.

Reference data for BabyBody-plethysmographic measurements in Chinese neonates and infants.

BACKGROUND AND OBJECTIVE: Population-specific pulmonary function reference data are essential to identify the nature and severity of respiratory diseases. However, there is a lack of reference data for Chinese neonates and infants. The objective of this study was to develop reference data for tidal breathing and plethysmographic measurements for Chinese subjects during the first 2 years of life. METHODS: Data of tidal breathing and plethysmography from healthy Chinese neonates (≤28 days) and infants (1-24 months) using the Jaeger MasterScreen BabyBody were collated. All subjects were sedated for the tests. Multivariable analyses were performed to determine predictive variables for the pulmonary function parameters. Reference equations for outcomes were constructed using multilevel modelling and the LMS (lambda-mu-sigma) method was used for establishing smoothed reference percentiles. RESULTS: Four hundred and ten healthy subjects were tested. Acceptable measurements of tidal breathing analysis and plethysmography outcomes were obtained in 396 (96.6%) and 370 (90.4%) subjects, respectively. Normal reference percentiles and equations for the main parameters of tidal breathing and plethysmography were derived from test occasions of 211 neonates and 185 infants. Body weight, crown-heel length and age were significantly associated with lung function, of which length was the strongest predictor. CONCLUSION: This study provides reference data of BabyBody-plethysmographic measurements for healthy Chinese subjects in their first 2 years of life. Weight and length are the strongest predictors for neonatal and infant lung function, respectively.

Exhaled nitric oxide is associated with postnatal adaptation to hypoxia in Tibetan and non-Tibetan newborn infants.

AIM: This Chinese study assessed partial pressure of exhaled nitric oxide (PeNO) in healthy Tibetan and non-Tibetan newborn infants born at a very high altitude. METHODS: Full-term Tibetan and non-Tibetan neonates born in Lhasa, 3658 metres above sea level, were compared to non-Tibetan neonates born in Kunming (1891 m) and Huai'an (16 m). The chemiluminiscence technique was used to measure the fraction of exhaled nitric oxide during spontaneous tidal breathing and this was then converted to partial pressure of exhaled nitric oxide (PeNO). RESULTS: In their first week, Tibetan and non-Tibetan neonates born in Lhasa had persistently higher PeNO levels than non-Tibetan neonates born in Kunming and Huai'an, which was further verified by partial pressure of inspired oxygen adjustment. However, the non-Tibetans born in Lhasa required short-term oxygen therapy to improve their early postnatal oxygenation. The temporal changes of PeNO and cardio-respiratory function measurements demonstrated that Tibetan and non-Tibetan newborns in Lhasa initially needed to adapt to attain homoeostasis in oxygenation and gas exchange. CONCLUSION: Tibetan and non-Tibetan newborn infants living at the same high altitude demonstrated comparable PeNO levels during postnatal adaptation to hypobaric hypoxia, which warrants further investigation of the mechanism of endogenous nitric oxide and hypoxic tolerance.

Combined iNO and endothelial progenitor cells improve lung alveolar and vascular structure in neonatal rats exposed to prolonged hyperoxia.

BACKGROUND: Stem cells or inhaled nitric oxide (iNO) are reported to improve lung structures in bronchopulmonary dysplasia (BPD) models. We hypothesized that combined iNO and transplanted endothelial progenitor cells (EPCs) might restore lung structure in rats after neonatal hyperoxia. METHODS: Litters were separated into eight groups: room air, hyperoxia, hyperoxia + iNO, hyperoxia + iNO + L-NAME, hyperoxia + EPCs, hyperoxia + EPCs + L-NAME, hyperoxia + EPCs + iNO, and hyperoxia + EPCs + iNO + L-NAME. Litters were exposed to hyperoxia from the 21st day, then, sacrificed. EPCs were injected on the 21st day. L-NAME was injected daily for 7 d from the 21st day. Serum vascular endothelial growth factor (VEGF), radial alveolar count (RAC), VIII factor, EPCs engraftment, lung VEGF, VEGFR2, endothelial nitric oxide (eNOS) and SDF-1 expression, and NO production were examined. RESULTS: Hyperoxia exposure led to air space enlargement, loss of lung capillaries, and low expression of VEGF and eNOS. Transplanted EPCs, when combined with iNO, had significantly increased engraftment in lungs, compared to EPCs alone, upon hyperoxia exposure. There was improvement in alveolarization, microvessel density, and upregulation of VEGF and eNOS proteins in the hyperoxia-exposed EPCs with iNO group, compared to hyperoxia alone. CONCLUSION: Combined EPCs and iNO improved lung structures after neonatal hyperoxia. This was associated with the upregulation of VEGF and eNOS expression.

The role of eNOS in the migration and proliferation of bone-marrow derived endothelial progenitor cells and in vitro angiogenesis.

The role of endothelial nitric oxide synthase (eNOS) in the activities of endothelial progenitor cells (EPCs) including migration, proliferation, and tube formation in vitro was investigated. EPCs were obtained from rat bone mononuclear cells by culturing for 7-10 days in EGM-2MV and identified by their capacity for FITC-UEA-1 binding and acetylated low-density lipoprotein (Dil-ac-LDL) intake using fluorescence microscopy. Migration, proliferation and tube formation activities were assessed in the presence or absence of N(ω)-nitro-L-argininemethylester (L-NAME), an eNOS inhibitor. mRNA and protein expression of CXCR4, CXCR7, VEGFR2, and eNOS were detected by real-time PCR and western blotting in the presence or absence of L-NAME. Nitric oxide production was detected by nitrate reductase in the presence or absence of L-NAME. Typical spindle-shaped cells appeared on the 7(th)-10(th) day and confluence reached about 80%. The percentage of FITC-UEA-1 and Dil-ac-LDL double-stained cells was about 85%. Cell migration, proliferation, and tube formation were significantly weakened after eNOS was inhibited (P < 0.05), and the expressions of CXCR4 and eNOS were significantly reduced (P < 0.05, respectively), but there was little change in CXCR7 and VEGFR2. NO production was dramatically decreased after eNOS was inhibited (P < 0.05). In summary, L-NAME significantly reduced the expression of eNOS and NO production by EPCs and inhibited migration, proliferation and tube formation by these cells, suggesting that eNOS affects EPC activities; CXCR4 may be implicated in the action of eNOS.

Molecular Dynamic Simulation To Reveal the Mechanism Underlying MGL-3196 Resistance to Thyroxine Receptor Beta.

Thyroxine receptor beta (TRß) is a ligand-dependent nuclear receptor that participates in regulating multiple biological processes, particularly playing an important role in lipid metabolism regulation. TRß is currently a popular therapeutic target for nonalcoholic steatohepatitis (NASH), while no drugs have been approved to treat this disease. MGL-3196 (Resmetirom) is the first TRß agonist that has succeeded in phase III clinical trials for the treatment of NASH; therefore, studying its molecular mechanism of action is of great significance. In this study, we employed molecular dynamic simulation to investigate the interaction mode between MGL-3196 and TRß at the all-atom level. More importantly, by comparing the binding patterns of MGL-3196 in several prevalent TRß mutants, it was identified that the mutations R243Q and H435R located, respectively, around and within the ligand-binding pocket of TRß cause TRß to be insensitive to MGL-3196. This indicates that patients with NASH carrying these two mutations may exhibit resistance to the medication of MGL-3196, thereby highlighting the potential impact of TRß mutations on TRß-targeted treatment of NASH and beyond.

Distinct functional organizations for processing different motion signals in V1, V2, and V4 of macaque.

Motion perception is qualitatively invariant across different objects and forms, namely, the same motion information can be conveyed by many different physical carriers, and it requires the processing of motion signals consisting of direction, speed, and axis or trajectory of motion defined by a moving object. Compared with the representation of orientation, the cortical processing of these different motion signals within the early ventral visual pathway of the primate remains poorly understood. Using drifting full-field noise stimuli and intrinsic optical imaging, along with cytochrome-oxidase staining, we found that the orientation domains in macaque V1, V2, and V4 that processed orientation signals also served to process motion signals associated with the axis and speed of motion. In contrast, direction domains within the thick stripes of V2 demonstrated preferences that were independent of motion speed. The population responses encoding the orientation and motion axis could be precisely reproduced by a spatiotemporal energy model. Thus, our observation of orientation domains with dual functions in V1, V2, and V4 directly support the notion that the linear representation of the temporal series of retinotopic activations may serve as another motion processing strategy in primate ventral visual pathway, contributing directly to fine form and motion analysis. Our findings further reveal that different types of motion information are differentially processed in parallel and segregated compartments within primate early visual cortices, before these motion features are fully combined in high-tier visual areas.