Tushar A. Shah

Echocardiographic detection of pulmonary hypertension in extremely low birth weight infants with bronchopulmonary dysplasia requiring prolonged positive pressure ventilation.

Objective:The goal of this study was to delineate the epidemiology of echocardiographically diagnosed pulmonary hypertension (PH) in extremely low birth weight (ELBW) infants with bronchopulmonary dysplasia (BPD) requiring prolonged positive pressure ventilation (PPV), and to determine the independent relationship between PH and mortality in these patients.Study Design:Our retrospective cohort included ELBW infants, with BPD requiring prolonged PPV, hospitalized in Cincinnati, Ohio during 2003–2009, as recorded in the National Institute of Child Health and Human Development Neonatal Research Network Database. Following chart review, a logistic regression model was constructed to understand the contribution of PH to mortality in infants with BPD requiring prolonged PPV.Result:We identified 216 patients (19%) with BPD requiring prolonged PPV among 1156 ELBW infants. Of these patients, 41% received echocardiography after 4 weeks of life, with 37% showing evidence of PH. Logistic regression analysis demonstrated that infants with BPD requiring prolonged PPV, with PH detectable by echocardiogram, were four times more likely to die (adjusted odds ratio): 4.6, 95% confidence interval: 1.3–16.5) when compared with infants with BPD requiring prolonged PPV without echocardiographic evidence of PH.Conclusion:Pulmonary hypertension appears to be an important, independent determinant of death in infants with BPD requiring prolonged PPV.

Sudden Infant Death Syndrome and Reported Maternal Smoking During Pregnancy

We investigated the effect of maternal smoking during pregnancy on the relative risk of sudden infant death syndrome (SIDS) by linking data from Georgia birth and death certificates from 1997 to 2000. We estimated the effect of misclassifying smokers as non-smokers and the effect of being misclassified on SIDS rates, and we calculated the fraction of cases caused by exposure. Of all SIDS cases, 21% were attributable to maternal smoking; among smokers, 61% of SIDS cases were attributable to maternal smoking. Maternal smoking during pregnancy is associated with a significantly increased risk of SIDS.

FOXM1 Promotes Allergen-Induced Goblet Cell Metaplasia and Pulmonary Inflammation

ABSTRACT Chronic airway disorders, including chronic obstructive pulmonary disease (COPD), cystic fibrosis, and asthma, are associated with persistent pulmonary inflammation and goblet cell metaplasia and contribute to significant morbidity and mortality worldwide. While the molecular pathogenesis of these disorders is actively studied, little is known regarding the transcriptional control of goblet cell differentiation and mucus hyperproduction. Herein, we demonstrated that pulmonary allergen sensitization induces expression of FOXM1 transcription factor in airway epithelial and inflammatory cells. Conditional deletion of the Foxm1 gene from either airway epithelium or myeloid inflammatory cells decreased goblet cell metaplasia, reduced lung inflammation, and decreased airway resistance in response to house dust mite allergen (HDM). FOXM1 induced goblet cell metaplasia and Muc5AC expression through the transcriptional activation of Spdef. FOXM1 deletion reduced expression of CCL11, CCL24, and the chemokine receptors CCR2 and CX3CR1, resulting in decreased recruitment of eosinophils and macrophages to the lung. Deletion of FOXM1 from dendritic cells impaired the uptake of HDM antigens and decreased cell surface expression of major histocompatibility complex II (MHC II) and costimulatory molecule CD86, decreasing production of Th2 cytokines by activated T cells. Finally, pharmacological inhibition of FOXM1 by ARF peptide prevented HDM-mediated pulmonary responses. FOXM1 regulates genes critical for allergen-induced lung inflammation and goblet cell metaplasia.

Forkhead Box M1 Transcription Factor Is Required for Macrophage Recruitment during Liver Repair

ABSTRACT Acute liver injury results from exposure to toxins, pharmacological agents, or viral infections, contributing to significant morbidity and mortality worldwide. While hepatic inflammation is critical for liver repair, the transcriptional mechanisms required for the recruitment of inflammatory cells to the liver are not understood. Forkhead box M1 (Foxm1) transcription factor is a master regulator of hepatocyte proliferation, but its role in inflammatory cells remains unknown. In this study, we generated transgenic mice in which Foxm1 was deleted from myeloid-derived cells, including macrophages, monocytes, and neutrophils. Carbon tetrachloride liver injury was used to demonstrate that myeloid-specific Foxm1 deletion caused a delay in liver repair. Although Foxm1 deficiency did not influence neutrophil infiltration into injured livers, the total numbers of mature macrophages were dramatically reduced. Surprisingly, Foxm1 deficiency did not influence the proliferation of macrophages or their monocytic precursors but impaired monocyte recruitment during liver repair. Expression of L-selectin and the CCR2 chemokine receptor, both critical for monocyte recruitment to injured tissues, was decreased. Foxm1 induced transcriptional activity of the mouse CCR2 promoter in cotransfection experiments. Adoptive transfer of monocytes to Foxm1-deficient mice restored liver repair and rescued liver function. Foxm1 is critical for liver repair and is required for the recruitment of monocytes to the injured liver.

Foxm1 Regulates Resolution of Hyperoxic Lung Injury in Newborns

Current treatments for inflammation associated with bronchopulmonary dysplasia (BPD) fail to show clinical efficacy. Foxm1, a transcription factor of the Forkhead box family, is a critical mediator of lung development and carcinogenesis, but its role in BPD-associated pulmonary inflammation is unknown. Immunohistochemistry and RNA analysis were used to assess Foxm1 in lung tissue from hyperoxia-treated mice and patients with BPD. LysM-Cre/Foxm1(-/-) mice, in which Foxm1 was deleted from myeloid-derived inflammatory cells, including macrophages, monocytes, and neutrophils, were exposed to neonatal hyperoxia, causing lung injury and remodeling. Measurements of lung function and flow cytometry were used to evaluate the effects of Foxm1 deletion on pulmonary inflammation and repair. Increased Foxm1 expression was observed in pulmonary macrophages of hyperoxia-exposed mice and in lung tissue from patients with BPD. After hyperoxia, deletion of Foxm1 from the myeloid cell lineage decreased numbers of interstitial macrophages (CD45(+)CD11b(+)Ly6C(-)Ly6G(-)F4/80(+)CD68(-)) and impaired alveologenesis and lung function. The exaggerated BPD-like phenotype observed in hyperoxia-exposed LysM-Cre/Foxm1(-/-) mice was associated with increased expression of neutrophil-derived myeloperoxidase, proteinase 3, and cathepsin g, all of which are critical for lung remodeling and inflammation. Our data demonstrate that Foxm1 influences pulmonary inflammatory responses to hyperoxia, inhibiting neutrophil-derived enzymes and enhancing monocytic responses that limit alveolar injury and remodeling in neonatal lungs.

Symptomatic nephrolithiasis in prolonged survivors of Duchenne muscular dystrophy

In this study, we describe the association between Duchenne muscular dystrophy (DMD) and symptomatic nephrolithiasis. The DMD patients were matched to non-ambulatory control patients with non-DMD neurological diagnoses via retrospective chart review. All patients with DMD and symptomatic nephrolithiasis were over 20 years old. We found that six of the 29 at-risk DMD patients had nephrolithiasis (20.7%) while only one of the 68 control patients had nephrolithiasis (1.5%) (p<0.0001). Controlling for duration of immobilization with stratified analysis, the risk ratio for nephrolithiasis among DMD patients compared with controls was 9.94. Using rate-based estimates of renal stone development per 10,000 patient-years, the ratio of stone development among DMD patients compared with controls was 18.5. On logistic regression analysis, the corrected odds ratio for nephrolithiasis comparing DMD patients to controls was 14.26. We conclude that, in our study group, DMD was an independent risk factor for symptomatic nephrolithiasis.

Complement inhibition significantly decreases red blood cell lysis in a rat model of acute intravascular hemolysis

Prevention of acute hemolytic transfusion reactions is a worldwide concern. The objective of this study was to develop a simple rat model of complement‐mediated acute intravascular hemolysis.

Peptide inhibitor of complement C1 modulates acute intravascular hemolysis of mismatched red blood cells in rats

Acute hemolytic transfusion reactions have a broad clinical presentation from mild and transitory signs and symptoms to shock, disseminated intravascular coagulation, renal failure, and death. We have recently developed a rat model of acute intravascular hemolysis showing that the classical complement pathway mediates antibody‐dependent hemolysis. The objective of this study was to evaluate the role of the classical pathway inhibitor peptide inhibitor of complement C1 (PIC1) in this animal model.

Complement Effectors of Inflammation in Cystic Fibrosis Lung Fluid Correlate with Clinical Measures of Disease

In cystic fibrosis (CF), lung damage is mediated by a cycle of obstruction, infection, and inflammation. Here we explored complement inflammatory effectors in CF lung fluid. In this study soluble fractions (sols) from sputum samples of 15 CF patients were assayed for complement effectors and analyzed with clinical measurements. The pro-inflammatory peptide C5a was increased 4.8-fold (P = 0.04) in CF sols compared with controls. Incubation of CF sols with P. aeruginosa or S. aureus increased C5a concentration 2.3-fold (P = 0.02). A peptide inhibitor of complement C1 (PIC1) completely blocked the increase in C5a concentration from P. aeruginosa in CF sol in vitro (P = 0.001). C5a concentration in CF sol correlated inversely with body mass index (BMI) percentile in children (r = -0.77, P = 0.04). C3a, which has anti-inflammatory effects, correlated positively with FEV1% predicted (rs = 0.63, P = 0.02). These results suggest that complement effectors may significantly impact inflammation in CF lung fluid.

Clinical hypothermia temperatures increase complement activation and cell destruction via the classical pathway.

BackgroundTherapeutic hypothermia is a treatment modality that is increasingly used to improve clinical neurological outcomes for ischemia-reperfusion injury-mediated diseases. Antibody-initiated classical complement pathway activation has been shown to contribute to ischemia-reperfusion injury in multiple disease processes. However, how therapeutic hypothermia affects complement activation is unknown. Our goal was to measure the independent effect of temperature on complement activation, and more specifically, examine the relationship between clinical hypothermia temperatures (31–33°C), and complement activation.MethodsAntibody-sensitized erythrocytes were used to assay complement activation at temperatures ranging from 0-41°C. Individual complement pathway components were assayed by ELISA, Western blot, and quantitative dot blot. Peptide Inhibitor of complement C1 (PIC1) was used to specifically inhibit activation of C1.ResultsAntibody-initiated complement activation resulting in eukaryotic cell lysis was increased by 2-fold at 31°C compared with 37°C. Antibody-initiated complement activation in human serum increased as temperature decreased from 37°C until dramatically decreasing at 13°C. Quantitation of individual complement components showed significantly increased activation of C4, C3, and C5 at clinical hypothermia temperatures. In contrast, C1s activation by heat-aggregated IgG decreased at therapeutic hypothermia temperatures consistent with decreased enzymatic activity at lower temperatures. However, C1q binding to antibody-coated erythrocytes increased at lower temperatures, suggesting that increased classical complement pathway activation is mediated by increased C1 binding at therapeutic hypothermia temperatures. PIC1 inhibited hypothermia-enhanced complement-mediated cell lysis at 31°C by up to 60% (P = 0.001) in a dose dependent manner.ConclusionsIn summary, therapeutic hypothermia temperatures increased antibody-initiated complement activation and eukaryotic cell destruction suggesting that the benefits of therapeutic hypothermia may be mediated via other mechanisms. Antibody-initiated complement activation has been shown to contribute to ischemia-reperfusion injury in several animal models, suggesting that for diseases with this mechanism hypothermia-enhanced complement activation may partially attenuate the benefits of therapeutic hypothermia.