Aging exacerbates murine lung ischemia-reperfusion injury by excessive inflammation and impaired tissue repair response.

Donor shortage is a major problem in lung transplantation (LTx), and the use of lungs from elderly donors is one of the possible solutions in a rapidly aging population. However, the utilization of organs from donors aged >65 years has remained infrequent and may be related to a poor outcome. To investigate the molecular events in grafts from elderly donors early after LTx, the left lungs of young and old mice were subjected to 1 hour of ischemia and subsequent reperfusion. The left lungs were collected at 1 hour, 1 day, and 3 days after reperfusion and subjected to wet-to-dry weight ratio measurement, histological analysis, and molecular biological analysis, including RNA sequencing. The lungs in old mice exhibited more severe and prolonged pulmonary edema than those in young mice after ischemia reperfusion, which was accompanied by upregulation of the genes associated with inflammation and impaired expression of cell cycle-related genes. Apoptotic cells increased and proliferating type 2 alveolar epithelial cells decreased in the lungs of old mice compared with young mice. These factors could become conceptual targets for developing interventions to ameliorate lung ischemia-reperfusion injury after LTx from elderly donors, which may serve to expand the old donor pool.

Quantitative Evaluation of Changes in Three-Dimensional CT Density Distributions in Pulmonary Alveolar Proteinosis after GM-CSF Inhalation.

BACKGROUND: A previous clinical trial for autoimmune pulmonary alveolar proteinosis (APAP) demonstrated that granulocyte-macrophage colony-stimulating factor (GM-CSF) inhalation reduced the mean density of the lung field on computed tomography (CT) across 18 axial slice planes at a two-dimensional level. In contrast, in this study, we challenged three-dimensional analysis for changes in CT density distribution using the same datasets. METHODS: As a sub-study of the trial, CT data of 31 and 27 patients who received GM-CSF and placebo, respectively, were analyzed. To overcome the difference between various shooting conditions, a newly developed automatic lung field segmentation algorithm was applied to CT data to extract the whole lung volume, and the accuracy of the segmentation was evaluated by five pulmonary physicians independently. For normalization, the percent pixel (PP) in a certain density range was calculated as a percentage of the total number of pixels from -1,000 to 0 HU. RESULTS: The automatically segmented images revealed that the lung field was accurately extracted except for 7 patients with minor deletion or addition. Using the change in PP from baseline to week 25 (ΔPP) as the vertical axis, we created a histogram with 143 HU bins set for each patient. The most significant difference in ΔPP between GM-CSF and placebo groups was observed in two ranges: from -1,000 to -857 and -143 to 0 HU. CONCLUSION: Whole lung extraction followed by density histogram analysis of ΔPP may be an appropriate evaluation method for assessing CT improvement in APAP.

Metabolic and Epigenetic Regulation of SMAD7 by STC1 Ameliorates Lung Fibrosis.

As shown in our previous studies, the intratracheal-administration of STC1 (stanniocalcin-1) ameliorates pulmonary fibrosis by reducing oxidative and endoplasmic reticulum stress through the uncoupling of respiration in a bleomycin-treated mouse model. However, the overall effect of STC1 on metabolism was not examined. Therefore, we first conducted a comprehensive metabolomics analysis to screen the overall metabolic changes induced by STC1 in an alveolar epithelial cell line using capillary electrophoresis time-of-flight mass spectrometry. The results were subsequently validated in multiple alveolar epithelial and fibroblast cell lines by performing precise analyses of each substance. STC1 stimulated glycolysis, acetyl-CoA synthesis, and the methionine and cysteine-glutathione pathways, which are closely related to the uncoupling of respiration, modulation of epigenetics, and reduction in oxidative stress. These results are consistent with our previous study. Subsequently, we focused on the inhibitory factor SMAD7, which exerts an antifibrotic effect and is susceptible to epigenetic regulation. STC1 upregulates SMAD7 in an uncoupling protein 2-dependent manner, induces demethylation of the SMAD7 promoter region and acetylation of the SMAD7 protein in human alveolar epithelial and fibroblast cell lines and a bleomycin-treated mouse model, and subsequently attenuates fibrosis. The antifibrotic effects of STC1 may partially depend on the regulation of SMAD7. In the evaluation using lung tissue from patients with idiopathic pulmonary fibrosis, SMAD7 expression and acetylation were high in the alveolar structure-preserving region and low in the fibrotic region. The intratracheal administration of STC1 may prevent the development of pulmonary fibrosis by regulating the metabolism-mediated epigenetic modification of SMAD7 in patients.

Inhaled GM-CSF for Pulmonary Alveolar Proteinosis.

BACKGROUND: Pulmonary alveolar proteinosis is a disease characterized by abnormal accumulation of surfactant in the alveoli. Most cases are autoimmune and are associated with an autoantibody against granulocyte-macrophage colony-stimulating factor (GM-CSF) that prevents clearing of pulmonary surfactant by alveolar macrophages. An open-label, phase 2 study showed some therapeutic efficacy of inhaled recombinant human GM-CSF in patients with severe pulmonary alveolar proteinosis; however, the efficacy in patients with mild-to-moderate disease remains unclear. METHODS: We conducted a double-blind, placebo-controlled trial of daily inhaled recombinant human GM-CSF (sargramostim), at a dose of 125 µg twice daily for 7 days, every other week for 24 weeks, or placebo in 64 patients with autoimmune pulmonary alveolar proteinosis who had a partial pressure of arterial oxygen (Pao2) while breathing ambient air of less than 70 mm Hg (or <75 mm Hg in symptomatic patients). Patients with severe pulmonary alveolar proteinosis (Pao2 <50 mm Hg) were excluded to avoid possible exacerbation of the disease in patients who were assigned to receive placebo. The primary end point was the change in the alveolar-arterial oxygen gradient between baseline and week 25. RESULTS: The change in the mean (±SD) alveolar-arterial oxygen gradient was significantly better in the GM-CSF group (33 patients) than in the placebo group (30 patients) (mean change from baseline, -4.50±9.03 mm Hg vs. 0.17±10.50 mm Hg; P = 0.02). The change between baseline and week 25 in the density of the lung field on computed tomography was also better in the GM-CSF group (between-group difference, -36.08 Hounsfield units; 95% confidence interval, -61.58 to -6.99, calculated with the use of the Mann-Whitney U test and the Hodges-Lehmann estimate of confidence intervals for pseudo-medians). Serious adverse events developed in 6 patients in the GM-CSF group and in 3 patients in the placebo group. CONCLUSIONS: In this randomized, controlled trial, inhaled recombinant human GM-CSF was associated with a modest salutary effect on the laboratory outcome of arterial oxygen tension, and no clinical benefits were noted. (Funded by the Japan Agency for Medical Research and Development and the Ministry of Health, Labor, and Welfare of Japan; PAGE ClinicalTrials.gov number, NCT02835742; Japan Medical Association Center for Clinical Trials number, JMA-IIA00205.).

Improvement of native pulmonary alveolar proteinosis after contralateral single living-donor lobar lung transplantation: A case report.

PAP is a rare disease characterized by the accumulation of surfactant materials in the alveolar spaces due to the imbalance of surfactant homeostasis (production and clearance). We herein report a case of an 8-year-old girl who developed PAP after BMT from her mother for the treatment of DBA. The anemia was improved by BMT; however, respiratory dysfunction due to graft-versus-host disease gradually progressed. She eventually underwent right single LDLLT from her mother when she was 14 years old. A pathological examination of the excised lung confirmed the finding of diffuse bronchiolitis obliterans and unexpectedly revealed widespread alveolar proteinosis. Interestingly, the GGO of her native left lung on chest X-ray was improved after LDLLT. We present the very unique clinical course of this patient and discuss the mechanisms underlying the development of PAP after BMT and its improvement after LDLLT from the same donor.

Bone marrow mesenchymal stromal cells protect allograft lung transplants from acute rejection via the PD-L1/IL-17A axis.

PURPOSE: Using a rat model of allograft lung transplantation, we investigated the effectiveness of mesenchymal stromal cells (MSCs) as prophylactic and therapeutic agents against the acute rejection of lung grafts. METHODS: Lung grafts were harvested from donor rats and transplanted orthotopically into major histocompatibility complex-mismatched rats. MSCs were administered to the recipients once (on day 0) or twice (on days 0 and 3) after transplantation. The grade of acute rejection was evaluated both macroscopically and microscopically 6 days after transplantation. To elucidate the related mechanism, mRNA levels of inflammatory cytokines and immunomodulatory receptors in the transplanted grafts were measured using quantitative RT-PCR. RESULTS: The lung graft tissue from the rats that received MSCs post-surgically was protected from acute rejection significantly better than that from the untreated controls. Notably, the rats administered MSCs twice after surgery exhibited the least signs of rejection, with a markedly upregulated mRNA level of PD-L1 and a downregulated mRNA level of IL-17A. CONCLUSION: This study assessed MSC protection of lung allografts from acute rejection by modulating T cell activity via enforced expression of PD-L1 in transplants and downregulation of IL-17A.

Exome sequencing deciphers a germline MET mutation in familial epidermal growth factor receptor-mutant lung cancer.

Lung cancer accompanied by somatic activating mutations in the epidermal growth factor receptor (EGFR) gene, which is associated with a significant clinical response to the targeted therapy, is frequently found in never-smoking Asian women with adenocarcinoma. Although this implies genetic factors underlying the carcinogenesis, the etiology remains unclear. To gain insight into the pathogenic mechanisms, we sequenced the exomes in the peripheral-blood DNA from six siblings, four affected and two unaffected siblings, of a family with familial EGFR-mutant lung adenocarcinoma. We identified a heterozygous missense mutation in MET proto-oncogene, p.Asn375Lys, in all four affected siblings. Combined with somatic loss of heterozygosity for MET, the higher allele frequency in a Japanese sequencing database supports a causative role of the MET mutation in EGFR-mutant lung cancer. Functional assays showed that the mutation reduces the binding affinity of MET for its ligand, hepatocyte growth factor, and damages the subsequent cellular processes, including proliferation, clonogenicity, motility and tumorigenicity. The MET mutation was further observed to abrogate the ERBB3-mediated AKT signal transduction, which is shared downstream by EGFR. These findings provide an etiological view that the MET mutation is involved in the pathogenesis of EGFR-mutant lung cancer because it generates oncogenic stress that induces compensatory EGFR activation. The identification of MET in a family with familial EGFR-mutant lung cancer is insightful to explore the pathogenic mechanism of not only familial, but also sporadic EGFR-mutant lung cancer by underscoring MET-related signaling molecules.

Mesenchymal stem cells attenuate ischemia-reperfusion injury after prolonged cold ischemia in a mouse model of lung transplantation: a preliminary study.

PURPOSE: Mesenchymal stem cells (MSCs) suppress inflammation and immune responses. We conducted this study to find out if MSCs attenuate ischemia-reperfusion injury in a mouse model of lung transplantation. METHODS: C57BL/6J mouse lungs perfused with low-potassium dextran glucose solution were preserved at 4 °C for 18 h. Human MSCs were slowly injected into the left pulmonary artery of the lung grafts, and orthotopic left lung transplantation was then performed. The lung isografts were reperfused for 6 h, and bronchoalveolar lavage fluid (BALF) from the left lung graft was collected. We measured the protein concentration, cell count, and proinflammatory cytokine concentrations in the BALF. RESULTS: The protein concentration and cell count in the BALF were significantly lower in the MSC-administered grafts than in the PBS-administered controls. Concentrations of proinflammatory cytokines, including IL-1ß, IL-17A, and TNF-α, in BALF tended to be lower in the MSC-administered grafts than in the controls, but the difference was not significant. CONCLUSION: The pre-transplant administration of MSCs via the pulmonary artery of the lung graft attenuated ischemia-reperfusion injury after prolonged cold ischemia in this mouse model of lung transplantation.

Mesenchymal stem cells correct inappropriate epithelial-mesenchyme relation in pulmonary fibrosis using stanniocalcin-1.

Current hypotheses suggest that aberrant wound healing has a critical role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). In these hypotheses, continuous TGF-ß1 secretion by alveolar epithelial cells (AECs) in abnormal wound healing has a critical role in promoting fibroblast differentiation into myofibroblasts. Mesenchymal stem cells (MSCs) home to the injury site and reduce fibrosis by secreting multifunctional antifibrotic humoral factors in IPF. In this study, we show that MSCs can correct the inadequate-communication between epithelial and mesenchymal cells through STC1 (Stanniocalcin-1) secretion in a bleomycin-induced IPF model. Inhalation of recombinant STC1 shows the same effects as the injection of MSCs. Using STC1 plasmid, it was possible to enhance the ability of MSCs to ameliorate the fibrosis. MSCs secrete large amounts of STC1 in response to TGF-ß1 in comparison to AECs and fibroblasts. The antifibrotic effects of STC1 include reducing oxidative stress, endoplasmic reticulum (ER) stress, and TGF-ß1 production in AECs. The STC1 effects can be controlled by blocking uncoupling protein 2 (UCP2) and the secretion is affected by the PI3/AKT/mTORC1 inhibitors. Our findings suggest that STC1 tends to correct the inappropriate epithelial-mesenchymal relationships and that STC1 plasmid transfected to MSCs or STC1 inhalation could become promising treatments for IPF.

A mathematical model to predict protein wash out kinetics during whole-lung lavage in autoimmune pulmonary alveolar proteinosis.

Whole-lung lavage (WLL) remains the standard therapy for pulmonary alveolar proteinosis (PAP), a process in which accumulated surfactants are washed out of the lung with 0.5-2.0 l of saline aliquots for 10-30 wash cycles. The method has been established empirically. In contrast, the kinetics of protein transfer into the lavage fluid has not been fully evaluated either theoretically or practically. Seventeen lungs from patients with autoimmune PAP underwent WLL. We made accurate timetables for each stage of WLL, namely, instilling, retaining, draining, and preparing. Subsequently, we measured the volumes of both instilled saline and drained lavage fluid, as well as the concentrations of proteins in the drained lavage fluid. We also proposed a mathematical model of protein transfer into the lavage fluid in which time is a single variable as the protein moves in response to the simple diffusion. The measured concentrations of IgG, transferrin, albumin, and ß2-microglobulin closely matched the corresponding theoretical values calculated through differential equations. Coefficients for transfer of ß2-microglobulin from the blood to the lavage fluid were two orders of magnitude higher than those of IgG, transferrin, and albumin. Simulations using the mathematical model showed that the cumulative amount of eliminated protein was not affected by the duration of each cycle but dependent mostly on the total time of lavage and partially on the volume instilled. Although physicians have paid little attention to the transfer of substances from the lung to lavage fluid, WLL seems to be a procedure that follows a diffusion-based mathematical model.

Outcome of corticosteroid administration in autoimmune pulmonary alveolar proteinosis: a retrospective cohort study.

BACKGROUND: Although no report has demonstrated the efficacy of corticosteroid therapy for autoimmune pulmonary alveolar proteinosis (aPAP), we sometimes encounter patients who have received this therapy for various reasons. However, as corticosteroids can suppress alveolar macrophage function, corticosteroid therapy might worsen disease severity and increase the risk of infections. METHODS: For this retrospective cohort study, we sent a screening form to 165 institutions asking for information on aPAP patients treated with corticosteroids. Of the resulting 45 patients screened, 31 were enrolled in this study. We collected demographic data and information about corticosteroid treatment period, dose, disease severity score (DSS) over the treatment period, and complications. RESULTS: DSS deteriorated during corticosteroid therapy in 23 cases (74.1 %) and the estimated overall cumulative worsening rate was 80.8 % for the total observation period. The worsening rate was significantly higher in patients treated with high-dose prednisolone (>18.9 mg/day, n = 16) than treated with low-dose prednisolone (≤18.9 mg/day, n = 15) divided by median daily dose (p < 0.02). Of patients with worsening, one died of disseminated aspergillosis and another of respiratory failure. Infections newly emerged in 6 cases during corticosteroid therapy (p < 0.05). Median serum granulocyte/macrophage colony-stimulating factor (GM-CSF) autoantibody levels were similar to previously reported data in a large cohort study. CONCLUSION: The results demonstrate that corticosteroid therapy may worsen DSS of aPAP, increasing the risk for infections.

Phase angle as an indicator of sarcopenia and malnutrition in patients with chronic obstructive pulmonary disease.

BACKGROUND: Phase angle (PhA), which is measured using bioelectrical impedance analysis, is an indicator of muscle quality and malnutrition. PhA has been shown to be correlated with sarcopenia and malnutrition; however, studies on patients with chronic obstructive pulmonary disease (COPD) are limited. In this study, we investigated the correlation between PhA and sarcopenia and malnutrition and determined the cutoff values of PhA for those in patients with COPD. METHODS: This study included 105 male patients with COPD (mean age 75.7 ± 7.7 years, mean forced expiratory volume in 1s % predicted [%FEV1] 57.0 ± 20.1%) and 12 male controls (mean age 74.1 ± 3.8 years) who were outpatients between December 2019 and March 2024. PhA was measured using the InBody S10, and its correlation with sarcopenia and malnutrition was assessed. The cutoff PhA values for sarcopenia and malnutrition were determined using receiver operating characteristic curves. RESULTS: The prevalence rates of sarcopenia and malnutrition were 31% and 22%, respectively, in patients with COPD. PhA significantly correlated with sarcopenia- and malnutrition-related indicators. Multivariate logistic regression analysis independently correlated PhA with sarcopenia and malnutrition. The cutoff values of the PhA for sarcopenia and malnutrition were 4.75° (AUC = 0.78, 95% CI = 0.68-0.88) and 4.25° (AUC = 0.75, 95% CI = 0.63-0.86), respectively. CONCLUSIONS: PhA was significantly correlated with sarcopenia and malnutrition in Japanese patients with COPD and may be a useful diagnostic indicator.

Mesenchymal stromal cells protect cancer cells from ROS-induced apoptosis and enhance the Warburg effect by secreting STC1.

Previous studies have demonstrated that mesenchymal stromal cells (MSCs) enhance cell survival through upregulation and secretion of stanniocalcin-1 (STC1). This study shows that MSC-derived STC1 promotes survival of lung cancer cells by uncoupling oxidative phosphorylation, reducing intracellular reactive oxygen species (ROS), and shifting metabolism towards a more glycolytic metabolic profile. MSC-derived STC1 upregulated uncoupling protein 2 (UCP2) in injured A549 cells in an STC1-dependent manner. Knockdown of UCP2 reduced the ability of MSCs and recombinant STC1 (rSTC1) to reduce cell death in the A549 population. rSTC1-treated A549 cells displayed decreased levels of ROS, mitochondrial membrane potential (MMP), and increased lactate production, all of which were dependent on the upregulation of UCP2. Our data suggest that MSCs can promote cell survival by regulating mitochondrial respiration via STC1.

A case report of Indium lung with progressive emphysema and fibrosis underwent lung unilateral transplantation 20 years after the end of the exposure.

BACKGROUND: Indium lung is characterized by interstitial pneumonia and/or emphysema which occurs in indium-tin oxide (ITO) workers. Indium lung is now known to progress after stopping exposure to ITO, but the long-term influences of ITO remain unclear. CASE PRESENTATION: Forty seven years old, a never-smoker, who had been engaged in an ITO manufacturing process for 8 years. Emphysema was indicated by the medical check-up for ex-ITO workers, and he was diagnosed with indium lung. He underwent partial lung resections for pneumothorax two times, and obstructive pulmonary dysfunction had progressed through the years. He underwent right single lung transplant 20 years after ITO exposure. Pathologically, his lung showed severe distal acinar emphysema and honeycomb change. Fibrosis and destruction of the lung tissue significantly progressed compared to the previous partial resections. Scanning electron microscopy combined with energy dispersive spectroscopy revealed that the deposited particles contained indium and tin. After the transplantation, his respiratory function was improved. CONCLUSIONS: In this case, ITO resided in the lung tissue for 20 years, and lung tissue destruction kept progressing. Careful medical follow-up is recommended for ITO-workers even if they are asymptomatic.

Paracrine factors of multipotent stromal cells ameliorate lung injury in an elastase-induced emphysema model.

Multipotent stromal cells (MSCs) ameliorate several types of lung injury. The differentiation of MSCs into specific cells at the injury site has been considered as the important process in the MSC effect. However, although MSCs reduce destruction in an elastase-induced lung emphysema model, MSC differentiation is relatively rare, suggesting that MSC differentiation into specific cells does not adequately explain the recuperation observed. Humoral factors secreted by MSCs may also play an important role in ameliorating emphysema. To confirm this hypothesis, emphysema was induced in the lungs of C57BL/6 mice by intratracheal elastase injection 14 days before intratracheal MSC or phosphate-buffered saline (PBS) administration. Thereafter, lungs were collected at several time points and evaluated. Our results showed that MSCs reduced the destruction in elastase-induced emphysema. Furthermore, double immunofluorescence staining revealed infrequent MSC engraftment and differentiation into epithelial cells. Real-time PCR showed increased levels of hepatocyte growth factor (HGF) and epidermal growth factor (EGF). Real-time PCR and western blotting showed enhanced production of secretory leukocyte protease inhibitor (SLPI) in the lung. In-vitro coculture studies confirmed the in vivo observations. Our findings suggest that paracrine factors derived from MSCs is the main mechanism for the protection of lung tissues from elastase injury.

A Novel Development of Sarcoidosis Following COVID-19 Vaccination and a Literature Review.

BNT162b2 (Pfizer/BioNTech) is a coronavirus disease 2019 (COVID-19) vaccine containing nucleoside-modified messenger RNA encoding the severe acute respiratory syndrome coronavirus 2 spike glycoprotein. Recently, ocular complications of mRNA vaccines have been reported increasingly frequently. However, immunological adverse events due to mRNA vaccines in real-world settings are not fully known. We herein report the novel development of sarcoidosis manifested as uveitis, bilateral hilar lymphadenopathy, angiotensin-converting enzyme elevation, and epithelioid and giant cell granuloma formation in the lung soon after the first BNT162b2 injection and review the current literature, including three reported cases of sarcoid-like reaction following COVID-19 vaccination.

Targeting stanniocalcin-1-expressing tumor cells elicits efficient antitumor effects in a mouse model of human lung cancer.

Lung cancer is the most common cause of cancer-related death in developed countries; therefore, the generation of effective targeted therapeutic regimens is essential. Recently, gene therapy approaches toward malignant cells have emerged as attractive molecular therapeutics. Previous studies have indicated that stanniocalcin-1 (STC-1), a hormone involved in calcium and phosphate homeostasis, positively regulates proliferation, apoptosis resistance, and glucose metabolism in lung cancer cell lines. In this study, we investigated if targeting STC-1 in tumor cells could be a promising strategy for lung cancer gene therapy. We confirmed that STC-1 levels in peripheral blood were higher in lung cancer patients than in healthy donors and that STC-1 expression was observed in five out of eight lung cancer cell lines. A vector expressing a suicide gene, uracil phosphoribosyltransferase (UPRT), under the control of the STC-1 promoter, was constructed (pPSTC-1 -UPRT) and transfected into three STC-1-positive cell lines, PC-9, A549, and H1299. When stably transfected, we observed significant cell growth inhibition using 5-fluorouracil (5-FU) treatment. Furthermore, growth of the STC-1-negative lung cancer cell line, LK-2 was significantly arrested when combined with STC-1-positive cells transfected with pPSTC-1 -UPRT. We believe that conferring cytotoxicity in STC-1-positive lung cancer cells using a suicide gene may be a useful therapeutic strategy for lung cancer.

Risk prediction for new-onset atrial fibrillation using the Minnesota code electrocardiography classification system.

BACKGROUND: Few risk models are available to predict future onset of atrial fibrillation (AF) in workers. We aimed to develop risk prediction models for new-onset AF, using annual health checkup (HC) data with electrocardiogram findings. METHODS AND RESULTS: We retrospectively included 56,288 factory or office workers (mean age = 51.5 years, 33.0% women) who underwent a HC at a medical center and fulfilled the following criteria; age ≥ 40 years, no history of AF, and greater than 1 annual follow-up HC in 2013-2016. Using Cox models with the Akaike information criterion, we developed and compared prediction models for new-onset AF with and without the Minnesota code information. We externally validated the discrimination accuracy of the models in a general Japanese population cohort, the Hisayama cohort. During the median 3.0-year follow-up, 209 (0.37%) workers developed AF. Age, sex, waist circumference, blood pressure, LDL cholesterol, and γ-GTP were associated with new-onset of AF. Using the Minnesota code information, the AUC significantly improved from 0.82 to 0.84 in the derivation cohort and numerically improved from 0.78 to 0.79 in the validation cohort, and from 0.77 to 0.79 in the Hisayama cohort. The NRI and IDI significantly improved in all and male subjects in both the derivation and validation cohorts, and in female subjects in both the validation and the Hisayama cohorts. CONCLUSIONS: We developed useful risk model with Minnesota code information for predicting new-onset AF from large worker population validated in the original and external cohorts, although study interpretation is limited by small improvement of AUC.

Genetic determinants of risk in autoimmune pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a devastating lung disease caused by abnormal surfactant homeostasis, with a prevalence of 6-7 cases per million population worldwide. While mutations causing hereditary PAP have been reported, the genetic basis contributing to autoimmune PAP (aPAP) has not been thoroughly investigated. Here, we conducted a genome-wide association study of aPAP in 198 patients and 395 control participants of Japanese ancestry. The common genetic variant, rs138024423 at 6p21, in the major-histocompatibility-complex (MHC) region was significantly associated with disease risk (Odds ratio [OR] = 5.2; P = 2.4 × 10-12). HLA fine-mapping revealed that the common HLA class II allele, HLA-DRB1*08:03, strongly drove this signal (OR = 4.8; P = 4.8 × 10-12), followed by an additional independent risk allele at HLA-DPß1 amino acid position 8 (OR = 0.28; P = 3.4 × 10-7). HLA-DRB1*08:03 was also associated with an increased level of anti-GM-CSF antibody, a key driver of the disease (ß = 0.32; P = 0.035). Our study demonstrated a heritable component of aPAP, suggesting an underlying genetic predisposition toward an abnormal antibody production.

Multipotent stromal cells are activated to reduce apoptosis in part by upregulation and secretion of stanniocalcin-1.

Multipotent stromal cells (MSCs) have been shown to reduce apoptosis in injured cells by secretion of paracrine factors, but these factors were not fully defined. We observed that coculture of MSCs with previously UV-irradiated fibroblasts reduced apoptosis of the irradiated cells, but fresh MSC conditioned medium was unable reproduce the effect. Comparative microarray analysis of MSCs grown in the presence or absence of UV-irradiated fibroblasts demonstrated that the MSCs were activated by the apoptotic cells to increase synthesis and secretion of stanniocalcin-1 (STC-1), a peptide hormone that modulates mineral metabolism and has pleiotrophic effects that have not been fully characterized. We showed that STC-1 was required but not sufficient for reduction of apoptosis of UV-irradiated fibroblasts. In contrast, we demonstrated that MSC-derived STC-1 was both required and sufficient for reduction of apoptosis of lung cancer epithelial cells made apoptotic by incubation at low pH in hypoxia. Our data demonstrate that STC-1 mediates the antiapoptotic effects of MSCs in two distinct models of apoptosis in vitro.