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The renin-angiotensin system is a highly characterized integrative pathway in mammalian homeostasis whose clinical spectrum has been expanded to lung disorders such as chronic obstructive pulmonary disease (COPD)-emphysema, idiopathic pulmonary fibrosis (IPF), and COVID pathogenesis. Despite this widespread interest, specific localization of this receptor family in the mammalian lung is limited, partially due to the imprecision of available antibody reagents. In this study, we establish the expression pattern of the two predominant angiotensin receptors in the human lung, AGTR1 and AGTR2 , using complementary and comprehensive bulk and single-cell RNA-sequence datasets that are publicly available. We show these two receptors have distinct localization patterns and developmental trajectories in the human lung, pericytes for AGTR1 and a subtype of alveolar epithelial type 2 cells for AGTR2 . In the context of disease, we further pinpoint AGTR2 localization to the COPD-associated subpopulation of alveolar epithelial type 2 (AT2 B ) and AGTR1 localization to fibroblasts, where their expression is upregulated in individuals with COPD, but not in individuals with IPF. Finally, we examine the genetic variation of the angiotensin receptors, finding AGTR2 associated with lung phenotype (i.e., cystic fibrosis) via rs1403543. Together, our findings provide a critical foundation for delineating this pathway's role in lung homeostasis and constructing rational approaches for targeting specific lung disorders., Competing Interests: Competing interest The authors declare no competing interests.

The connection between aging-related immune dysfunction and the lung manifestations of aging is poorly understood. A detailed characterization of the aging IL10-deficient murine lung, a model of accelerated aging and frailty, reconciles features of both immunosenescence and lung aging in a coherent model. Airspace enlargement developed in the middle-aged (12 months old) and aged (20-22 months old) IL10-deficient lung punctuated by an expansion of macrophages and alveolar cell apoptosis. Compared to wild-type (WT) controls, the IL10-deficient lungs from young (4-month-old) mice showed increased oxidative stress which was enhanced in both genotypes by aging. Active caspase 3 staining was increased in the alveolar epithelial cells of aged WT and mutant lungs but was greater in the IL10-deficient milieu. Lung macrophages were increased in the aged IL10-deficient lungs with exuberant expression of MMP12. IL10 treatment of naïve and M2-polarized bone marrow-derived WT macrophages reduced MMP12 expression. Conditioned media studies demonstrated the secretome of aged mutant macrophages harbors reduced AECII prosurvival factors, specifically keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF), promotes cell death, and reduces survival of primary alveolar epithelial cells. Compared to WT controls, aged IL10-deficient mice have increased parenchymal lymphoid collections comprised of a reduced number of apoptotic cells and B cells. We establish that IL10 is a key modulator of airspace homeostasis and lymphoid morphogenesis in the aging lung enabling macrophage-mediated alveolar epithelial cell survival and B-cell survival within tertiary lymphoid structures., (© 2020 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.)

Chronic obstructive pulmonary disease (COPD) is a prevalent smoking-related disease for which no disease-altering therapies currently exist. As dysregulated TGF-β signaling associates with lung pathology in patients with COPD and in animal models of lung injury induced by chronic exposure to cigarette smoke (CS), we postulated that inhibiting TGF-β signaling would protect against CS-induced lung injury. We first confirmed that TGF-β signaling was induced in the lungs of mice chronically exposed to CS as well as in COPD patient samples. Importantly, key pathological features of smoking-associated lung disease in patients, e.g., alveolar injury with overt emphysema and airway epithelial hyperplasia with fibrosis, accompanied CS-induced alveolar cell apoptosis caused by enhanced TGF-β signaling in CS-exposed mice. Systemic administration of a TGF-β-specific neutralizing antibody normalized TGF-β signaling and alveolar cell death, conferring improved lung architecture and lung mechanics in CS-exposed mice. Use of losartan, an angiotensin receptor type 1 blocker used widely in the clinic and known to antagonize TGF-β signaling, also improved oxidative stress, inflammation, metalloprotease activation and elastin remodeling. These data support our hypothesis that inhibition of TGF-β signaling through angiotensin receptor blockade can attenuate CS-induced lung injury in an established murine model. More importantly, our findings provide a preclinical platform for the development of other TGF-β-targeted therapies for patients with COPD.

Background: Respiratory dysfunction is a major contributor to morbidity and mortality in aged populations. The susceptibility to pulmonary insults is attributed to "low pulmonary reserve", ostensibly reflecting a combination of age-related musculoskeletal, immunologic and intrinsic pulmonary dysfunction., Methods/principal Findings: Using a murine model of the aging lung, senescent DBA/2 mice, we correlated a longitudinal survey of airspace size and injury measures with a transcriptome from the aging lung at 2, 4, 8, 12, 16 and 20 months of age. Morphometric analysis demonstrated a nonlinear pattern of airspace caliber enlargement with a critical transition occurring between 8 and 12 months of age marked by an initial increase in oxidative stress, cell death and elastase activation which is soon followed by inflammatory cell infiltration, immune complex deposition and the onset of airspace enlargement. The temporally correlative transcriptome showed exuberant induction of immunoglobulin genes coincident with airspace enlargement. Immunohistochemistry, ELISA analysis and flow cytometry demonstrated increased immunoglobulin deposition in the lung associated with a contemporaneous increase in activated B-cells expressing high levels of TLR4 (toll receptor 4) and CD86 and macrophages during midlife. These midlife changes culminate in progressive airspace enlargement during late life stages., Conclusion/significance: Our findings establish that a tissue-specific aging program is evident during a presenescent interval which involves early oxidative stress, cell death and elastase activation, followed by B lymphocyte and macrophage expansion/activation. This sequence heralds the progression to overt airspace enlargement in the aged lung. These signature events, during middle age, indicate that early stages of the aging immune system may have important correlates in the maintenance of tissue morphology. We further show that time-course analyses of aging models, when informed by structural surveys, can reveal nonintuitive signatures of organ-specific aging pathology.

Background: Nocardia infection occurs in 2.1-3.5% of lung transplant recipients, and may involve cavitary nodular pulmonary lesions, soft tissue infection, or other sites of dissemination. Nocardiosis can pose challenging clinical problems in the areas of diagnosis and treatment. Diagnostic delays may occur, and adverse reactions to therapy are common. This study reviews clinical and epidemiological aspects of nocardiosis in lung transplant recipients, with special attention to pitfalls in management. Clinicians should be alert for these possibilities in order to institute prompt therapy and to achieve successful outcomes., Methods: A retrospective cohort study was conducted of 577 lung transplant recipients from January 1991 to May 2007. Demographics, reason for transplant, recent rejection, time from transplantation, site of infection, hypogammaglobulinemia, and/or neutropenia shortly before onset, Pneumocystis jiroveci prophylaxis, Nocardia species, radiographic findings, extrapulmonary lesions, nature and duration of treatment, adverse reactions, and outcomes were recorded., Result: Nocardia infection occurred in 1.9% (11/577). Mean onset was 14.3 months after transplant (range 1.5-39 months). N. asteroides was isolated in 55% (6/11). Emphysema was the most common reason for transplant (7/11, 64%). Six patients were receiving trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis at the time of diagnosis. Three patients had immune globulin G levels <400 mg/dL and 2 were neutropenic in the 3 months preceding diagnosis. Diagnosis was made by bronchoalveolar lavage (55%), skin abscess culture (18%), open lung biopsy (9%), pleural fluid (9%), and sputum culture (9%). Definitive diagnosis required a median of 9 days and a mean of 13.6 days (range 3-35 days) from the time of diagnostic sampling. Soft tissue lesions occurred in 3 and central nervous system involvement in 1 patient. Adverse reactions to therapy occurred in 9/10 (90%) of patients for whom information was available. Nocardia-related mortality occurred in 2/11 patients (18%)., Conclusions: Nocardiosis occurred in 1.9% of lung transplant recipients and was associated with a mean of nearly 2 weeks to diagnosis and frequent adverse effects on therapy. TMP-SMX prophylaxis on a thrice weekly basis did not prevent all episodes of nocardiosis. Despite utilization of protocol bronchoscopies with cultures for Nocardia, this organism remains a source of clinical complexity in the lung transplant population.

Lung resection provides the best chance of cure for individuals with early-stage non-small-cell lung cancer. Lung resection will lead to a decrease in lung function. The population that develops lung cancer often has concomitant lung disease and a reduced ability to tolerate further losses in lung function. The goal of the preoperative pulmonary assessment of individuals with resectable lung cancer is to identify those individuals whose short- and long-term morbidity and mortality would be unacceptably high if surgical resection were to occur. Pulmonary function measures such as the forced expiratory volume in 1 second (FEV1) and the diffusing capacity for carbon monoxide (DLCO) are useful predictors of postoperative outcome. When lung function in not normal, the prediction of postoperative lung function from preoperative results, and the assessment of exercise capacity, can help to clarify the risks. Testing algorithms and published guidelines help to direct the order of testing. Interventions that allow us to consider resection outside of the guidelines, or to maximize the potential to tolerate lung resection, help us to offer potentially curative treatment to as many as possible. Knowledge of alternative treatment options will help to guide those deemed unfit for resection.

The present study was designed to test the hypothesis that aromatization is involved in the maintenance by testosterone of the appetitive component of male sexual behavior. We measured appetitive sexual behavior by administering behavioral tests in bilevel chambers and quantifying anticipatory level changes during a 5-min period prior to introduction of a stimulus female. In addition, we recorded standard measures of consummatory male sexual behavior after the female was introduced. Following 3 weekly tests, level-changing behavior reached a plateau and remained stable for up to 10 weeks. After 10 bilevel tests, rats were given subcutaneous testosterone capsules to clamp circulating androgen at physiological levels. Rats were tested and divided into two groups that were matched for measures of sexual behavior. One group was then treated with the nonsteroidal aromatase inhibitor, Fadrozole (2.5 mg/kg/day), given subcutaneously in beta-cyclodextrin and the other group was treated with vehicle. Within 1 week of Fadrozole treatment, the number of anticipatory levels changes was significantly reduced, but not the latency to begin searching. Fadrozole treatment also significantly reduced all measures of copulatory behavior over the period of treatment and increased latencies to first mount, intromission, and ejaculation. After 8 weeks, both treatment groups were given an additional Silastic capsule filled with estradiol and tested for 4 additional weeks. Estrogen treatment partially restored level-changing behavior, mounts, and intromissions but had little effect on ejaculations. These results support the view that aromatization is important for maintaining both the appetitive and the consummatory aspects of sexual behavior in male rats.

PC-SPES, a proprietary mixture composed of eight different herbs, is used worldwide as an alternative treatment by prostate cancer patients. It has been suggested that the clinical and in vitro antitumor activity exhibited by PC-SPES may be due to estrogenic activity, which in turn may be mediated by the presence of undeclared prescription drug contaminants. Here, we evaluated the in vivo effects of two different commercial lots of PC-SPES in male and female rats. Our high-pressure liquid chromatography analysis coupled with gas chromatography/mass spectrometry analysis by an independent laboratory suggested that PC-SPES lot 5430125 was contaminated with diethylstilbestrol (DES), whereas lot 5431249 was not. Treatment of male rats with PC-SPES lot 5430125 or DES alone reduced the weight of androgen target organs and decreased circulating levels of sex steroids and luteinizing hormone, whereas lot 5431249 was without effect. In addition, lot 5430125 and DES, but not lot 5431249 increased uterine weight in female rats. These results suggest that the inhibitory effects on androgen targets are mediated through suppression of the hypothalamic-pituitary axis and this suppression is probably due to DES contamination. We assessed the effects of both lots of PC-SPES and DES on hepatic cytochrome P450 expression and activity. Both lots of PC-SPES and DES reduced CYP3A activity and protein levels. Because the response of CYP3A to PC-SPES was not dependent on whether it contained DES, a phytochemical component of PC-SPES is most likely responsible for this effect. Inhibition of CYP3A has important implications for potential herbal-drug interactions.