Browsing by Subject "Pulmonology"

Now showing 1 - 3 of 3
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    17β-Estradiol and estrogen receptor α protect right ventricular function in pulmonary hypertension via BMPR2 and apelin
    (American Society for Clinical Investigation, 2021-03-15) Frump, Andrea L.; Albrecht, Marjorie; Yakubov, Bakhtiyor; Breuils-Bonnet, Sandra; Nadeau, Valérie; Tremblay, Eve; Potus, Francois; Omura, Junichi; Cook, Todd; Fisher, Amanda; Rodriguez, Brooke; Brown, R. Dale; Stenmark, Kurt R.; Rubinstein, C. Dustin; Krentz, Kathy; Tabima, Diana M.; Li, Rongbo; Sun, Xin; Chesler, Naomi C.; Provencher, Steeve; Bonnet, Sebastien; Lahm, Tim; Medicine, School of Medicine
    Women with pulmonary arterial hypertension (PAH) exhibit better right ventricular (RV) function and survival than men; however, the underlying mechanisms are unknown. We hypothesized that 17β-estradiol (E2), through estrogen receptor α (ER-α), attenuates PAH-induced RV failure (RVF) by upregulating the procontractile and prosurvival peptide apelin via a BMPR2-dependent mechanism. We found that ER-α and apelin expression were decreased in RV homogenates from patients with RVF and from rats with maladaptive (but not adaptive) RV remodeling. RV cardiomyocyte apelin abundance increased in vivo or in vitro after treatment with E2 or ER-α agonist. Studies employing ER-α–null or ER-β–null mice, ER-α loss-of-function mutant rats, or siRNA demonstrated that ER-α is necessary for E2 to upregulate RV apelin. E2 and ER-α increased BMPR2 in pulmonary hypertension RVs and in isolated RV cardiomyocytes, associated with ER-α binding to the Bmpr2 promoter. BMPR2 is required for E2-mediated increases in apelin abundance, and both BMPR2 and apelin are necessary for E2 to exert RV-protective effects. E2 or ER-α agonist rescued monocrotaline pulmonary hypertension and restored RV apelin and BMPR2. We identified what we believe to be a novel cardioprotective E2/ER-α/BMPR2/apelin axis in the RV. Harnessing this axis may lead to novel RV-targeted therapies for PAH patients of either sex.
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    Frataxin deficiency promotes endothelial senescence in pulmonary hypertension
    (The American Society for Clinical Investigation, 2021-06-01) Culley, Miranda K.; Zhao, Jingsi; Tai, Yi Yin; Tang, Ying; Perk, Dror; Negi, Vinny; Yu, Qiujun; Woodcock, Chen-Shan C.; Handen, Adam; Speyer, Gil; Kim, Seungchan; Lai, Yen-Chun; Satoh, Taijyu; Watson, Annie M.M.; Al Aaraj, Yassmin; Sembrat, John; Rojas, Mauricio; Goncharov, Dmitry; Goncharova, Elena A.; Khan, Omar F.; Anderson, Daniel G.; Dahlman, James E.; Gurkar, Aditi U.; Lafyatis, Robert; Fayyaz, Ahmed U.; Redfield, Margaret M.; Gladwin, Mark T.; Rabinovitch, Marlene; Gu, Mingxia; Bertero, Thomas; Chan, Stephen Y.; Medicine, School of Medicine
    The dynamic regulation of endothelial pathophenotypes in pulmonary hypertension (PH) remains undefined. Cellular senescence is linked to PH with intracardiac shunts; however, its regulation across PH subtypes is unknown. Since endothelial deficiency of iron-sulfur (Fe-S) clusters is pathogenic in PH, we hypothesized that a Fe-S biogenesis protein, frataxin (FXN), controls endothelial senescence. An endothelial subpopulation in rodent and patient lungs across PH subtypes exhibited reduced FXN and elevated senescence. In vitro, hypoxic and inflammatory FXN deficiency abrogated activity of endothelial Fe-S–containing polymerases, promoting replication stress, DNA damage response, and senescence. This was also observed in stem cell–derived endothelial cells from Friedreich’s ataxia (FRDA), a genetic disease of FXN deficiency, ataxia, and cardiomyopathy, often with PH. In vivo, FXN deficiency–dependent senescence drove vessel inflammation, remodeling, and PH, whereas pharmacologic removal of senescent cells in Fxn-deficient rodents ameliorated PH. These data offer a model of endothelial biology in PH, where FXN deficiency generates a senescent endothelial subpopulation, promoting vascular inflammatory and proliferative signals in other cells to drive disease. These findings also establish an endothelial etiology for PH in FRDA and left heart disease and support therapeutic development of senolytic drugs, reversing effects of Fe-S deficiency across PH subtypes.
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    Simultaneous pancreas and kidney transplant after bilateral lung transplant for a recipient with cystic fibrosis
    (Elsevier, 2021) Fridell, Jonathan A.; Lutz, Andrew J.; Powelson, John A.; Surgery, School of Medicine
    Cystic fibrosis (CF) is an inherited autosomal recessive disorder. Despite optimized therapy, the majority of affected individuals ultimately die of respiratory failure. Lung transplantation is the only available therapy that deals definitively with the end-stage pulmonary disease and has become the treatment of choice for some of these patients. As patients with CF are living longer, extrapulmonary manifestations may develop including pancreatic failure, which manifests as exocrine insufficiency and CF-related diabetes (CFRD). Both of these can be managed through pancreas transplantation. We have previously reported our series of three simultaneous lung and pancreas transplants in patients with CF, which were complicated by surgical issues for both the thoracic and abdominal portions, rejection and resistant infections with disappointing long-term survival. Based on these results, a sequential approach was adopted: first, the thoracic transplant; and second, once the patient has recovered, the abdominal transplants. This is the first reported case of pancreas and kidney transplantation performed after a lung transplant in a patient with CF. It demonstrates a successful approach to treating CF with a lung transplant, and in an effort to improve the patient's long-term outcome, treating CFRD and pancreatic enzyme insufficiency, with a subsequent pancreas transplant.