These studies suggest that S1PL is a novel endogenous suppressor of pulmonary fibrosis in human IPF and animal models.

Background: Previous work determined that early life exposure to low-dose Bisphenol A (BPA) increased rat prostate cancer risk with aging. Herein, we report on prostate-specific results from CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity), which aims to resolve uncertainties regarding BPA toxicity. Objectives: We sought to a ) reassess whether a range of BPA exposures drives prostate pathology and/or alters prostatic susceptibility to hormonal carcinogenesis, and b ) test whether chronic low-dose BPA targets prostate epithelial stem and progenitor cells. Methods: Sprague-Dawley rats were gavaged daily with vehicle, ethinyl estradiol (EE) or BPA/kg-BW during development or chronically, and prostate pathology was assessed at one year. One developmentally exposed cohort was given testosterone plus estradiol ( ) implants at day 90 to promote carcinogenesis with aging. Epithelial stem and progenitor cells were isolated by prostasphere (PS) culture from dorsolateral prostates (DLP) of rats continuously exposed for six months to BPA/kg-BW. Gene expression was analyzed by quantitative real time reverse transcription polymerase chain reaction (qRT-PCR). Results: Exposure to BPA alone at any dose did not drive prostate pathology. However, rats treated with EE, 2.5, 250, or BPA/kg-BW plus showed greater severity of lateral prostate intraepithelial neoplasia (PIN), and DLP ductal adenocarcinoma multiplicity was markedly elevated in tumor-bearing rats exposed to -BW. DLP stem cells, assessed by PS number, doubled with chronic EE and exposures. PS size, reflecting progenitor cell proliferation, was greater at 25 and BPA doses, which also shifted lineage commitment toward basal progenitors while reducing luminal progenitor cells. Conclusions: Together, these results confirm and extend previous evidence using a rat model and human prostate epithelial cells that low-dose BPA augments prostate cancer susceptibility and alters adult prostate stem cell homeostasis. Therefore, we propose that BPA exposures may contribute to the increased carcinogenic risk in humans that occurs with aging. https://doi.org/10.1289/EHP3953

Using primary cultures of normal human prostate epithelial cells, we developed a novel prostasphere-based, label-retention assay that permits identification and isolation of stem cells at a single cell level. Their bona fide stem cell nature was corroborated using in vitro and in vivo regenerative assays and documentation of symmetric/asymmetric division. Robust WNT10B and KRT13 levels without E-cadherin or KRT14 staining distinguished individual stem cells from daughter progenitors in spheroids. Following FACS to isolate label-retaining stem cells from label-free progenitors, RNA-seq identified unique gene signatures for the separate populations which may serve as useful biomarkers. Knockdown of KRT13 or PRAC1 reduced sphere formation and symmetric self-renewal highlighting their role in stem cell maintenance. Pathways enrichment identified ribosome biogenesis and membrane estrogen-receptor signaling in stem cells with NF-κB signaling enriched in progenitors; activities that were biologically confirmed. Further, bioassays identified heightened autophagy flux and reduced metabolism in stem cells relative to progenitors. These approaches similarly identified stem-like cells from prostate cancer specimens and prostate, breast and colon cancer cell lines suggesting wide applicability. Together, the present studies isolate and identify unique characteristics of normal human prostate stem cells and uncover processes that maintain stem cell homeostasis in the prostate gland.

The role of thyroid hormone metabolism in clinical outcomes of the critically ill remains unclear. Using preclinical models of acute lung injury (ALI), we assessed the gene and protein expression of type 2 deiodinase (DIO2), a key driver for synthesis of biologically active triiodothyronine, and addressed potential association of DIO2 genetic variants with ALI in a multiethnic cohort. DIO2 gene and protein expression levels in murine lung were validated by microarrays and immunoblotting. Lung injury was assessed by levels of bronchoalveolar lavage protein and leukocytes. Single-nucleotide polymorphisms were genotyped and ALI susceptibility association assessed. Significant increases in both DIO2 gene and D2 protein expression were observed in lung tissues from murine ALI models (LPS-and ventilator-induced lung injury), with expression directly increasing with the extent of lung injury. Mice with reduced levels of DIO2 expression (by silencing RNA) demonstrated reduced thyroxine levels in plasma and increased lung injury (increased bronchoalveolar lavage protein and leukocytes), suggesting a protective role for DIO2 in ALI. The G (Ala) allele of the Thr92Ala coding single-nucleotide polymorphism (rs225014) was protective in severe sepsis and severe sepsis-associated ALI after adjustments for age, sex, and genetic ancestry in a logistic regression model in European Americans. Our studies indicate that DIO2 is a novel ALI candidate gene, the nonsynonymous Thr92Ala coding variant of which confers ALI protection. Increased DIO2 expression may dampen the ALI inflammatory response, thereby strengthening the premise that thyroid hormone metabolism is intimately linked to the integrated response to inflammatory injury in critically ill patients.Keywords: acute respiratory distress syndrome; hypothyroidism; mechanical ventilation; sepsis Acute lung injury (ALI) is one of the major causes of acute respiratory failure that usually develops in response to major insults, such as sepsis, trauma, pneumonia, and multiple transfusions (1). Although mechanical ventilation (MV) is indispensable for the survival of patients with ALI (2), clinical trials have shown that improperly delivered MV causes or worsens lung injury, a syndrome known as ventilator-induced lung injury (VILI). ALI and VILI are characterized by augmented capillary leakage, acute inflammation, and increases in inflammatory cytokine expression (3, 4). Microarray analyses have identified a number of ALI-associated candidate genes correlated with the outcome of both ALI and VILI (5-8). Case-control association studies further support that genetic variants in these genes contribute to susceptibility and survival of sepsis and ALI (8-12). Despite these increasing insights into ALI/VILI pathobiology, ALI continues to carry an unacceptably high mortality (.30%), and the basis for the increased ALI morbidity/mortality remains poorly understood.Clinicians have had a long-standing interest in the enigmatic role of thyroid hormones (THs) in critically ill patients (13) who e...

Microvascular injury and increased vascular leakage are prominent features of radiation-induced lung injury (RILI), and often follow cancer-associated thoracic irradiation. Our previous studies demonstrated that polymorphisms in the gene (MIF) encoding macrophage migratory inhibition factor (MIF), a multifunctional pleiotropic cytokine, confer susceptibility to acute inflammatory lung injury and increased vascular permeability, particularly in senescent mice. In this study, we exposed wild-type and genetically engineered mif 2/2 mice to 20 Gy single-fraction thoracic radiation to investigate the agerelated role of MIF in murine RILI (mice were aged 8 wk, 8 mo, or 16 mo). Relative to 8-week-old mice, decreased MIF was observed in bronchoalveolar lavage fluid and lung tissue of 8-to 16-month-old wild-type mice. In addition, radiated 8-to 16-month-old mif 2/2 mice exhibited significantly decreased bronchoalveolar lavage fluid total antioxidant concentrations with progressive age-related decreases in the nuclear expression of NF-E2-related factor-2 (Nrf2), a transcription factor involved in antioxidant gene up-regulation in response to reactive oxygen species. This was accompanied by decreases in both protein concentrations (NQO1, GCLC, and heme oxygenase-1) and mRNA concentrations (Gpx1, Prdx1, and Txn1) of Nrf2-influenced antioxidant gene targets. In addition, MIF-silenced (short, interfering RNA) human lung endothelial cells failed to express Nrf2 after oxidative (H 2 O 2 ) challenge, an effect reversed by recombinant MIF administration. However, treatment with an antioxidant (glutathione reduced ester), but not an Nrf2 substrate (N-acetyl cysteine), protected aged mif 2/2 mice from RILI. These findings implicate an important role for MIF in radiation-induced changes in lung-cell antioxidant concentrations via Nrf2, and suggest that MIF may contribute to age-related susceptibility to thoracic radiation.