708 research outputs found
Ureaplasma-Driven Neuroinflammation in Neonates: Assembling the Puzzle Pieces
Ureaplasma species (spp.) are commonly regarded as lowvirulence colonizers of the genitourinary tract. Intrauterine
Ureaplasma infection, however, has been associated with
chorioamnionitis and preterm birth. The overall impact of a
neonatal Ureaplasma colonization is yet to be understood.
High pathogen prevalence and frequent neurological morbidities particularly in immature preterm infants call for an
assessment of the significance of Ureaplasma spp. in neonatal neuroinflammation. This narrative review summarizes
clinical data, animal studies, and in vitro results to elucidate
potential Ureaplasma-associated neurological morbidities
as well as underlying mechanisms. Increasing evidence indicates an involvement of Ureaplasma spp. in invasive central
nervous system infections, suggesting a meticulous ability
of Ureaplasma spp. to interfere with immune defense mechanisms. Ultimately, Ureaplasma spp. should be considered as
relevant pathogens in neonatal neuroinflammation
IFN-Ī³ and TNF-Ī± synergize to inhibit CTGF expression in human lung endothelial cells.
Connective tissue growth factor (CTGF/CCN2) is an angiogenetic and profibrotic factor, acting downstream of TGF-Ī², involved in both airway- and vascular remodeling. While the T-helper 1 (Th1) cytokine interferon-gamma (IFN-Ī³) is well characterized as immune-modulatory and anti-fibrotic cytokine, the role of IFN-Ī³ in lung endothelial cells (LEC) is less defined. Tumour necrosis factor alpha (TNF-Ī±) is another mediator that drives vascular remodeling in inflammation by influencing CTGF expression. In the present study we investigated the influence of IFN-Ī³ and TNF-Ī± on CTGF expression in human LEC (HPMEC-ST1.6R) and the effect of CTGF knock down on human LEC. IFN-Ī³ and TNF-Ī± down-regulated CTGF in human LEC at the promoter-, transcriptional- and translational-level in a dose- and time-dependent manner. The inhibitory effect of IFN-Ī³ on CTGF-expression could be almost completely compensated by the Jak inhibitor AG-490, showing the involvement of the Jak-Stat signaling pathway. Besides the inhibitory effect of IFN-Ī³ and TNF-Ī± alone on CTGF expression and LEC proliferation, these cytokines had an additive inhibitory effect on proliferation as well as on CTGF expression when administered together. To study the functional role of CTGF in LEC, endogenous CTGF expression was down-regulated by a lentiviral system. CTGF silencing in LEC by transduction of CTGF shRNA reduced cell proliferation, but did not influence the anti-proliferative effect of IFN-Ī³ and TNF-Ī±. In conclusion, our data demonstrated that CTGF was negatively regulated by IFN-Ī³ in LEC in a Jak/Stat signaling pathway-dependent manner. In addition, an additive effect of IFN-Ī³ and TNF-Ī± on inhibition of CTGF expression and cell proliferation could be found. The inverse correlation between IFN-Ī³ and CTGF expression in LEC could mean that screwing the Th2 response to a Th1 response with an additional IFN-Ī³ production might be beneficial to avoid airway remodeling in asthma
Recommended from our members
Familial Pulmonary Capillary Hemangiomatosis Early in Life
Background: Pulmonary capillary hemangiomatosis (PCH) is a rare disease, especially in infancy. Four infants have been reported up to the age of 12 months. So far, no familial patients are observed at this age. Patients: We report three siblings, two female newborns and a foetus of 15-week gestation of unrelated, healthy parents suffering from histologically proven PCH. The first girl presented with increased O2 requirements shortly after birth and patent ductus arteriosus (PDA). She subsequently developed progressive respiratory failure and pulmonary hypertension and died at the age of five months. The second girl presented with clinical signs of bronchial obstruction at the age of three months. The work-up showed a PDAāwhich was surgically closedāpulmonary hypertension, and bronchial wall instability with stenosis of the left main bronchus. Transient oxygen therapy was required with viral infections. The girl is now six years old and clinically stable without additional O2 requirements. Failure to thrive during infancy and a somewhat delayed development may be the consequence of the disease itself but also could be attributed to repeated episodes of respiratory failure and a long-term systemic steroid therapy. The third pregnancy ended as spontaneous abortion. The foetus showed histological signs of PCH. Conclusion: Despite the differences in clinical course, the trias of PCH, PDA, and pulmonary hypertension in the two life born girls suggests a genetic background
Infection of Human Coronary Artery Endothelial Cells by Group B Streptococcus Contributes to Dysregulation of Apoptosis, Hemostasis, and Innate Immune Responses
Early onset sepsis due to group B streptococcus leads to neonatal morbidity, increased mortality, and long-term neurological deficencies. Interaction between septicemic GBS and confluent monolayers of human coronary artery endothelial cells (HCAECs) was analyzed by genome wide expression profiling. In total, 124 genes were differentially expressed (89 upregulated, 35 downregulated) based on a more than 3-fold difference to control HCAEC. Regulated genes are involved in apoptosis, hemostasis, oxidative stress response, infection, and inflammation. Regulation of selected genes and proteins identified in the gene array analysis was confirmed by Real-time RT-PCR assay (granulocyte chemotactic protein 2), ELISA (urokinase, cyclooxygenase 2, granulocyte chemotactic protein 1), and western blotting (Heme oxygenase1, BCL2 interacting protein) at various time points between 4 and 24 hours. These results indicate that GBS infection might influence signalling pathways leading to impaired function of the innate immune system and hemorrhagic and inflammatory complications during GBS sepsis
Poractant alfa (CurosurfĀ®) increases phagocytosis of apoptotic neutrophils by alveolar macrophages in vivo
<p>Abstract</p> <p>Background</p> <p>Clearance of apoptotic neutrophils in the lung is an essential process to limit inflammation, since they could become a pro-inflammatory stimulus themselves. The clearance is partially mediated by alveolar macrophages, which phagocytose these apoptotic cells. The phagocytosis of apoptotic immune cells by monocytes in vitro has been shown to be augmented by several constituents of pulmonary surfactant, e.g. phospholipids and hydrophobic surfactant proteins. In this study, we assessed the influence of exogenous poractant alfa (Curosurf<sup>Ā®</sup>) instillation on the in vivo phagocytosis of apoptotic neutrophils by alveolar macrophages.</p> <p>Methods</p> <p>Poractant alfa (200 mg/kg) was instilled intratracheally in the lungs of three months old adult male C57/Black 6 mice, followed by apoptotic neutrophil instillation. Bronchoalveloar lavage was performed and alveolar macrophages and neutrophils were counted. Phagocytosis of apoptotic neutrophils was quantified by determining the number of apoptotic neutrophils per alveolar macrophages.</p> <p>Results</p> <p>Exogenous surfactant increased the number of alveolar macrophages engulfing apoptotic neutrophils 2.6 fold. The phagocytosis of apoptotic neutrophils was increased in the presence of exogenous surfactant by a 4.7 fold increase in phagocytosed apoptotic neutrophils per alveolar macrophage.</p> <p>Conclusions</p> <p>We conclude that the anti-inflammatory properties of surfactant therapy may be mediated in part by increased numbers of alveolar macrophages and increased phagocytosis of apoptotic neutrophils by alveolar macrophages.</p
Familial Pulmonary Capillary Hemangiomatosis Early in Life
Background. Pulmonary capillary hemangiomatosis (PCH) is a rare disease, especially in infancy. Four infants have been reported up to the age of 12 months. So far, no familial patients are observed at this age. Patients. We report three siblings, two female newborns and a foetus of 15-week gestation of unrelated, healthy parents suffering from histologically proven PCH. The first girl presented with increased O(2) requirements shortly after birth and patent ductus arteriosus (PDA). She subsequently developed progressive respiratory failure and pulmonary hypertension and died at the age of five months. The second girl presented with clinical signs of bronchial obstruction at the age of three months. The work-up showed a PDAāwhich was surgically closedāpulmonary hypertension, and bronchial wall instability with stenosis of the left main bronchus. Transient oxygen therapy was required with viral infections. The girl is now six years old and clinically stable without additional O(2) requirements. Failure to thrive during infancy and a somewhat delayed development may be the consequence of the disease itself but also could be attributed to repeated episodes of respiratory failure and a long-term systemic steroid therapy. The third pregnancy ended as spontaneous abortion. The foetus showed histological signs of PCH. Conclusion. Despite the differences in clinical course, the trias of PCH, PDA, and pulmonary hypertension in the two life born girls suggests a genetic background
A first-in-human clinical study of a new SP-B and SP-C enriched synthetic surfactant (CHF5633) in preterm babies with respiratory distress syndrome
Objective CHF5633 (Chiesi Farmaceutici S.p.A., Parma, Italy) is the first fully synthetic surfactant enriched by peptide analogues of two human surfactant proteins. We planned to assess safety and tolerability of CHF5633 and explore preliminary efficacy. Design Multicentre cohort study. Patients Forty infants from 27+0 to 33+6 weeks gestation with respiratory distress syndrome requiring fraction of inspired oxygen (FiO2) ā„0.35 were treated with a single dose of CHF5633 within 48āhours after birth. The first 20 received 100 mg/kg and the second 20 received 200āmg/kg. Outcome measures Adverse events (AEs) and adverse drug reactions (ADRs) were monitored with complications of prematurity considered AEs if occurring after dosing. Systemic absorption and immunogenicity were assessed. Efficacy was assessed by change in FiO2 after dosing and need for poractant-alfa rescue. Results Rapid and sustained improvements in FiO2 were observed in 39 (98%) infants. One responded neither to CHF5633 nor two poractant-alfa doses. A total of 79 AEs were experienced by 19 infants in the 100āmg/kg cohort and 53 AEs by 20 infants in the 200āmg/kg cohort. Most AEs were expected complications of prematurity. Two unrelated serious AEs occurred in the second cohort. One infant died of necrotising enterocolitis and another developed viral bronchiolitis after discharge. The single ADR was an episode of transient endotracheal tube obstruction following a 200āmg/kg dose. Neither systemic absorption, nor antibody development to either peptide was detected. Conclusions Both CHF5633 doses were well tolerated and showed promising clinical efficacy profile. These encouraging data provide a basis for ongoing randomised controlled trials
ŠŃŠ¾Š±ŠµŠ½Š½Š¾ŃŃŠø ŃŠøŠ»Š¾ŃŠ¾ŃŃŠŗŠ¾Š³Š¾ Š¼ŠøŃŠ¾Š²Š¾Š·Š·ŃŠµŠ½ŠøŃ Š®Š¶Š½Š¾Š³Š¾ Š”ŃŠ“Š°Š½Š°
Bronchopulmonary dysplasia (BPD), associated with chorioamnionitis, results from the simultaneous effects of disrupted lung development, lung injury, and repair superimposed on the developing lung. Caveolins (Cavs) are implicated as major modulators of lung injury and remodeling by multiple signaling pathways, although Cavs have been minimally studied in the injured developing lung. We hypothesized that chorioamnionitis-associated antenatal lung inflammation would decrease the expression of Cav-1 in preterm fetal lungs. We tested whether changes occurred in the transcription factors Smad2/3, Smad1/5, Stat3, and Stat1, and we also studied the activation of acid-sphingomyelinase (a-SMase) with the generation of ceramide, along with changes in the expression of heme oxygenaseā1 (HO-1) as indicators of possible Cav-1āmediated effects. Fetal sheep were exposed to 10 mg of intra-amniotic endotoxin or saline for 2, 7, or 2 + 7 days before preterm delivery at 124 days of gestation. The expression of Cav-1 and HO-1 and the phosphorylation of Smad and Stat were evaluated by real-time PCR, Western blotting, and/or immunohistochemistry. The activity of a-SMase and the concentrations of ceramide were measured. Intra-amniotic endotoxin decreased Cav-1 mRNA and protein expression in the lungs, with a maximum reduction of Cav-1 mRNA to 50% Ā± 7% of the control value (P < 0.05), and of Cav-1 protein expression to 20% Ā± 5% of the control value (P < 0.05). Decreased concentrations of Cav-1 were associated with the elevated phosphorylation of Smad2/3, Stat3, and Stat1, but not of Smad1/5. The expression of HO-1, a-SMase activity, and ceramide increased. Antenatal inflammation decreased the expression of Cav-1 in the preterm fetal lung. The decreased expression of Cav-1 was associated with the activation of the Smad2/3, Stat, and a-SMase/ceramide pathways, and with the increased expression of HO-1. The decreased concentrations of Cav-1 and changes in other signaling pathways may contribute to BPD
Perinatal Ureaplasma Exposure Is Associated With Increased Risk of Late Onset Sepsis and Imbalanced Inflammation in Preterm Infants and May Add to Lung Injury
Background: Controversy remains concerning the impact of Ureaplasma on preterm neonatal morbidity.Methods: Prospective single-center study in very low birth weight infants <30 weeks' gestation. Cord blood and initial nasopharyngeal swabs were screened for Ureaplasma parvum and U. urealyticum using culture technique and polymerase chain reaction. Neonatal outcomes were followed until death or discharge. Multi-analyte immunoassay provided cord blood levels of inflammatory markers. Using multivariate regression analyses, perinatal Ureaplasma exposure was evaluated as risk factor for the development of bronchopulmonary dysplasia (BPD), other neonatal morbidities until discharge and systemic inflammation at admission.Results: 40/103 (39%) infants were positive for Ureaplasma in one or both specimens, with U. parvum being the predominant species. While exposure to Ureaplasma alone was not associated with BPD, we found an increased risk of BPD in Ureaplasma-positive infants ventilated ā„5 days (OR 1.64; 95% CI 0.12ā22.98; p = 0.009). Presence of Ureaplasma was associated with a 7-fold risk of late onset sepsis (LOS) (95% CI 1.80ā27.39; p = 0.014). Moreover, Ureaplasma-positive infants had higher I/T ratios (b 0.39; 95% CI 0.08ā0.71; p = 0.014), increased levels of interleukin (IL)-17 (b 0.16; 95% CI 0.02ā0.30; p = 0.025) and matrix metalloproteinase 8 (b 0.77; 95% CI 0.10ā1.44; p = 0.020), decreased levels of IL-10 (b ā0.77; 95% CI ā1.58 to ā0.01; p = 0.043) and increased ratios of Tumor necrosis factor-Ī±, IL-8, and IL-17 to anti-inflammatory IL-10 (p = 0.003, p = 0.012, p < 0.001).Conclusions: Positive Ureaplasma screening was not associated with BPD. However, exposure contributed to BPD in infants ventilated ā„5 days and conferred an increased risk of LOS and imbalanced inflammatory cytokine responses
Ureaplasma-driven neonatal neuroinflammation: novel insights from an ovine model
Ureaplasma species (spp.) are considered commensals of the adult genitourinary tract, but have been associated with chorioamnionitis, preterm birth, and invasive infections in neonates, including meningitis. Data on mechanisms involved in Ureaplasma-driven neuroinflammation are scarce. The present study addressed brain inflammatory responses in preterm lambs exposed to Ureaplasma parvum (UP) in utero. 7 days after intra-amniotic injection of UP (nā=ā10) or saline (nā=ā11), lambs were surgically delivered at gestational day 128ā129. Expression of inflammatory markers was assessed in different brain regions using qRT-PCR and in cerebrospinal fluid (CSF) by multiplex immunoassay. CSF was analyzed for UP presence using ureB-based real-time PCR, and MRI scans documented cerebral white matter area and cortical folding. Cerebral tissue levels of atypical chemokine receptor (ACKR) 3, caspases 1-like, 2, 7, and CāXāC chemokine receptor (CXCR) 4 mRNA, as well as CSF interleukin-8 protein concentrations were significantly increased in UP-exposed lambs. UP presence in CSF was confirmed in one animal. Cortical folding and white matter area did not differ among groups. The present study confirms a role of caspases and the transmembrane receptors ACKR3 and CXCR4 in Ureaplasma-driven neuroinflammation. Enhanced caspase 1-like, 2, and 7 expression may reflect cell death. Increased ACKR3 and CXCR4 expression has been associated with inflammatory central nervous system (CNS) diseases and impaired bloodābrain barrier function. According to these data and previous in vitro findings from our group, we speculate that Ureaplasma-induced caspase and receptor responses affect CNS barrier properties and thus facilitate neuroinflammation
- ā¦