Aging promotes pro-fibrotic matrix production and increases fibrocyte recruitment during acute lung injury.

Fibrotic lung diseases increase with age. Previously we determined that senescence increases tissue expression of fibronectin EDA (Fn-EDA) and decreases fibroblast expression of Thy-1, and that fibrocytes contribute to fibrosis following bleomycin-induced lung injury in mice. In this study we hypothesized that fibroblasts lacking Thy-1 expression produce an extracellular matrix that promotes fibrocyte retention and myofibroblast transdifferentiation, thereby promoting fibrogenesis. Young and old mice were treated with bleomycin intratracheally; fibrocytes in the bone marrow, blood, and lungs were quantified, and lung fibroblast Thy-1 expression assessed. Bone marrow-derived fibrocytes were cultured on matrices derived from Thy-1(+) or Thy-1(-) fibroblasts ± the pro-fibrotic cytokine TGFβ1. Older mice had more fibrocytes in their bone marrows at baseline and more fibrocytes in their lungs following bleomycin treatment. In parallel, lung fibroblasts in older mice had lower expression of Thy-1 at baseline that increased transiently 7 days after bleomycin treatment but then rapidly waned such that 14 days after bleomycin treatment Thy-1 expression was again markedly lower. Fibrocytes cultured on matrices derived from Thy-1(-) fibroblasts + TGFβ1 had increased gene expression for collagen type 1, fibronectin, Fn-EDA, and α-smooth muscle actin. In parallel, whereas the matrices derived from Thy-1(-) fibroblasts stimulated phosphorylation of Akt in cultured fibrocytes, the matrices derived from Thy-1(+) fibroblasts induced apoptosis. These findings suggest that senescence increases fibrocyte recruitment to the lung following injury and that loss of Thy-1 expression by lung fibroblasts promotes fibrocyte retention and myofibroblast trans-differentiation that renders the "aging lung" susceptible to fibrosis

Effect of Bone Marrow-Derived Mesenchymal Stem Cells on Endotoxin-Induced Oxidation of Plasma Cysteine and Glutathione in Mice

Bone marrow-derived mesenchymal stem cells (BMDMSC) are emerging as a therapeutic modality in various inflammatory disease states, including acute lung injury (ALI). A hallmark of inflammation, and a consistent observation in patients with ALI, is a perturbation in the systemic redox environment. However, little is known about the effects of BMDMSC on the systemic redox status. The objective of the present study was to determine whether exogenously infused BMDMSC protect against endotoxin-induced oxidation of plasma cysteine (Cys) and glutathione (GSH) redox states. To determine the effect on the redox state if BMDMSC, mice received endotoxin intraperitoneally (1 mg/kg), followed by intravenous infusion of either 5 × 105 BMDMSC or an equal volume of saline solution. Control mice received intraperitoneal endotoxin followed by 5 × 105 lung fibroblasts given intravenously. Cys, cystine (CySS), GSH, and glutathione disulfide (GSSG) concentrations were determined by HPLC. Results showed sequential preservation of plasma Cys and GSH levels in response to BMDMSC infusion. The data show that BMDMSC infusion leads to a more reducing Cys and GSH redox state. The findings are the first to demonstrate that BMDMSC have antioxidant effects in vivo, and add to our understanding of the systemic effects of BMDMSC in lung injury

A Complex Cell Division Machinery Was Present in the Last Common Ancestor of Eukaryotes

Background: The midbody is a transient complex structure containing proteins involved in cytokinesis. Up to now, it has been described only in Metazoa. Other eukaryotes present a variety of structures implied in the last steps of cell division, such as the septum in fungi or the phragmoplast in plants. However, it is unclear whether these structures are homologous (derive from a common ancestral structure) or analogous (have distinct evolutionary origins). Recently, the proteome of the hamster midbody has been characterized and 160 proteins identified. Methodology/Principal Findings: Using phylogenomic approaches, we show here that nearly all of these 160 proteins (95%) are conserved across metazoan lineages. More surprisingly, we show that a large part of the mammalian midbody components (91 proteins) were already present in the last common ancestor of all eukaryotes (LECA) and were most likely involved in the construction of a complex multi-protein assemblage acting in cell division. Conclusions/Significance: Our results indicate that the midbodies of non-mammalian metazoa are likely very similar to the mammalian one and that the ancestor of Metazoa possessed a nearly modern midbody. Moreover, our analyses support the hypothesis that the midbody and the structures involved in cytokinesis in other eukaryotes derive from a large and complex structure present in LECA, likely involved in cytokinesis. This is an additional argument in favour of the idea of a comple

A Pilot Study of IL-2Rα Blockade during Lymphopenia Depletes Regulatory T-cells and Correlates with Enhanced Immunity in Patients with Glioblastoma

Preclinical studies in mice have demonstrated that the prophylactic depletion of immunosuppressive regulatory T-cells (T(Regs)) through targeting the high affinity interleukin-2 (IL-2) receptor (IL-2Rα/CD25) can enhance anti-tumor immunotherapy. However, therapeutic approaches are complicated by the inadvertent inhibition of IL-2Rα expressing anti-tumor effector T-cells.To determine if changes in the cytokine milieu during lymphopenia may engender differential signaling requirements that would enable unarmed anti-IL-2Rα monoclonal antibody (MAbs) to selectively deplete T(Regs) while permitting vaccine-stimulated immune responses.A randomized placebo-controlled pilot study was undertaken to examine the ability of the anti-IL-2Rα MAb daclizumab, given at the time of epidermal growth factor receptor variant III (EGFRvIII) targeted peptide vaccination, to safely and selectively deplete T(Regs) in patients with glioblastoma (GBM) treated with lymphodepleting temozolomide (TMZ).Daclizumab treatment (n = 3) was well-tolerated with no symptoms of autoimmune toxicity and resulted in a significant reduction in the frequency of circulating CD4+Foxp3+ TRegs in comparison to saline controls (n = 3)( p = 0.0464). A significant (p<0.0001) inverse correlation between the frequency of TRegs and the level of EGFRvIII specific humoral responses suggests the depletion of TRegs may be linked to increased vaccine-stimulated humoral immunity. These data suggest this approach deserves further study.ClinicalTrials.gov NCT00626015

Dapsone-induced Hemolytic Anemia in Lung Allograft Recipients

Background: Ling transplant (LT) recipients often receive dapsone for Pneumocystis jirovecii pneumonia (PCP) prophylaxis. However, the prevalence of dapsone-induced hematologic toxicity in LT recipients is unknown. We report it high prevalence of hemolytic anemia (HA) associated with dapsone use in LT patients when compared with other patients described in the literature who have been prescribed dapsone prophylaxis. Methods: We performed a retrospective chart review on all LT recipients who received dapsone prophylaxis between 2004 and 2006. Demographics, ideal body weight (IBW), severity of anemia, transfusion requirements, laboratory evidence of hemolysis, serum creatinine and glucose-6-phosphate dehydrogenase (G6PD) enzyme levels were collected. Results: Forty-three patients received dapsone. Ten (22.7%) patients had HA, despite normal G6PD levels. The mean drop in hemoglobin from baseline was 2.7 g/dl (95% confidence interval [CI] 1.9 to 3.5, p < 0.0001). Of those patients with HA, 6 had elevated serum creatinine from baseline. The odds ratio for hemolysis was 4.75 for each 1.0-mg/dl increase in creatinine (95% CI 1.07 to 21-03, P = 0.04). Mean IBW for the HA group was 58.4 kg. A dapsone close of 100 mg/day orally resulted in a mean dose of 1.7 mg/kg. Conclusions: The prevalence of dapsone-induced HA in LT recipients is 5-fold higher than the reported rate in the population of human immunodeficiency virus (HIV) patients. Individuals with renal failure or tow body weight and for whom dose exceeds 1.5 mg/kg may be at increased risk for clapsone-induced HA. Although current CDC guidelines do not recommend adjusting dose by IBW or renal function, We Suggest that consideration should be given to these dosing strategies. J Heart Lung Transplant 2008;27:1198-202. (C) 2008 Published by Elsevier Inc. on behalf of the International Society for Heart and Lung Transplantation

Bilateral Lung Transplant With Pulmonary Thromboendarterectomy for Eisenmenger’s Syndrome

Patients with secondary pulmonary hypertension frequently present for evaluation for lung transplantation. In some of these patients, Eisenmenger’s syndrome has developed from chronic left to right intracardiac shunts. A smaller group of these patients will also have associated pulmonary artery aneurysms. There is a paucity of literature discussing this topic, however, and currents reports have suggested the need to replace the abnormal pulmonary artery. This paper discusses a patient in whom Eisenmenger’s syndrome developed from an atrial septal defect, and resultant pulmonary artery aneurysms and mural thrombi, who underwent successful bilateral lung transplantation with thromboendarterectomy and atrial septal defect closure

Access to

Bone marrow-derived mesenchymal stem cells (BMDMSC) are emerging as a therapeutic modality in various inflammatory disease states, including acute lung injury (ALI). A hallmark of inflammation, and a consistent observation in patients with ALI, is a perturbation in the systemic redox environment. However, little is known about the effects of BMDMSC on the systemic redox status. The objective of the present study was to determine whether exogenously infused BMDMSC protect against endotoxininduced oxidation of plasma cysteine (Cys) and glutathione (GSH) redox states. To determine the effect on the redox state if BMDMSC, mice received endotoxin intraperitoneally (1 mg/kg), followed by intravenous infusion of either 5 × 10 5 BMDMSC or an equal volume of saline solution. Control mice received intraperitoneal endotoxin followed by 5 × 10 5 lung fibroblasts given intravenously. Cys, cystine (CySS), GSH, and glutathione disulfide (GSSG) concentrations were determined by HPLC. Results showed sequential preservation of plasma Cys and GSH levels in response to BMDMSC infusion. The data show that BMDMSC infusion leads to a more reducing Cys and GSH redox state. The findings are the first to demonstrate that BMDMSC have antioxidant effects in vivo, and add to our understanding of the systemic effects of BMDMSC in lung injury

Bilateral Lung Transplantation Offers Better Long-Term Survival, Compared With Single-Lung Transplantation, for Younger Patients With Idiopathic Pulmonary Fibrosis

Single-lung transplantation (SLT) and bilateral lung transplantation (BLT) are both good options for patients with end-stage lung disease secondary to idiopathic pulmonary fibrosis. It is, however, unclear whether BLT offers any survival advantage over SLT. The purpose of our study was to evaluate a large group of patients to determine if either SLT or BLT officered a long-term survival advantage for patients with IPF. This was an Institutional Review Board-approved retrospective analysis of the United Network of Organ Sharing database from 1987 to 2008. Survival was determined using Kaplan-Meir estimates and the effect of laterality was determined by Cox proportional hazards and propensity analyses. Lung transplantation for idiopathic pulmonary fibrosis was performed in 3,860 patients (2,431 SLTs and 1429 BLTs). Multivariate and propensity analysis failed to show any survival advantage for BLT (hazard ratio = 0.90, 95% confidence interval = 0.78 to 1.0, p = 0.11). One-year conditional survival favored BLT (hazard ratio 0.73, 95% confidence interval 0.60 to 0.87, p = 0.00064). Risk factors for early death included recipient age over 57 and donor age over 36 years. Bilateral lung transplantation should be considered for younger patients with idiopathic pulmonary fibrosis and results may be optimized when younger donors are used