Pulmonary vasoconstriction in response to alveolar hypoxia (HPV) is frequently impaired in patients with sepsis or acute respiratory distress syndrome or in animal models of endotoxemia. Pulmonary vasodilation due to overproduction of nitric oxide (NO) by NO synthase 2 (NOS2) may be responsible for this impaired HPV after administration of endotoxin (LPS). We investigated the effects of acute nonspecific (N(G)-nitro-L-arginine methyl ester, L-NAME) and NOS2-specific [L-N6-(1-iminoethyl)lysine, L-NIL] NOS inhibition and congenital deficiency of NOS2 on impaired HPV during endotoxemia. The pulmonary vasoconstrictor response and pulmonary vascular pressure-flow (P-Q) relationship during normoxia and hypoxia were studied in isolated, perfused, and ventilated lungs from LPS-pretreated and untreated wild-type and NOS2-deficient mice with and without L-NAME or L-NIL added to the perfusate. Compared with lungs from untreated mice, lungs from LPS-challenged wild-type mice constricted less in response to hypoxia (69 +/- 17 vs. 3 +/- 7%, respectively, P < 0.001). Perfusion with L-NAME or L-NIL restored this blunted HPV response only in part. In contrast, LPS administration did not impair the vasoconstrictor response to hypoxia in NOS2-deficient mice. Analysis of the pulmonary vascular P-Q relationship suggested that the HPV response may consist of different components that are specifically NOS isoform modulated in untreated and LPS-treated mice. These results demonstrate in a murine model of endotoxemia that NOS2-derived NO production is critical for LPS-mediated development of impaired HPV. Furthermore, impaired HPV during endotoxemia may be at least in part mediated by mechanisms other than simply pulmonary vasodilation by NOS2-derived NO overproduction.
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Viruses
December 2024
Laboratory of Virology, National Institute for Infectious Diseases "Lazzaro Spallanzani" (IRCCS), 00149 Rome, Italy.
Persistence is a strategy used by many viruses to evade eradication by the immune system, ensuring their permanence and transmission within the host and optimizing viral fitness. During persistence, viruses can trigger various phenomena, including target organ damage, mainly due to an inflammatory state induced by infection, as well as cell proliferation and/or immortalization. In addition to immune evasion and chronic inflammation, factors contributing to viral persistence include low-level viral replication, the accumulation of viral mutants, and, most importantly, maintenance of the viral genome and reliance on viral oncoprotein production.
View Article and Find Full Text PDFVaccines (Basel)
December 2024
Department of Infectious Diseases, University Medical Centre Utrecht, 3584 CX Utrecht, The Netherlands.
Background: In recent decades, the number of immunocompromised patients (ICPs) has increased significantly. ICPs have an impaired immune system, making them susceptible to complicated infections. To protect them from infections, ICPs are eligible to receive several medically indicated vaccines.
View Article and Find Full Text PDFJ Thorac Oncol
December 2024
Moores Cancer Center, University of California San Diego, La Jolla, CA 92037, USA; Department of Medicine, University of California San Diego, La Jolla, CA 92037, USA; Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Introduction: Copy-number (CN) loss of chromosome 9p, or parts thereof, impair immune response and confer ICT resistance by direct elimination of immune-regulatory genes on this arm, notably IFNγ genes at 9p24.1, and type-I interferon (IFN-I) genes at 9p21.3.
View Article and Find Full Text PDFFront Immunol
December 2024
Department of Pathology, Stavanger University Hospital, Stavanger, Norway.
Human papilloma virus (HPV) infections vary in their oncogenic potential, and whether an infection progresses to cervical intraepithelial neoplasia (CIN) also depends on the immune response. Therefore, the aim of the present study was to explore biomarkers related to the immune system and cell proliferation, in combination with HPV classified as having high (HOP) or low oncogenic potential (LOP), that can possibly guide a more accurate identification of women following cervical cancer screening programmes in need for immediate follow-up with a biopsy. A next-generation sequencing transcriptomic immune profile analysis applied to 28 persistent CIN3 lesions and 14 normal biopsies identified four genes, the immune markers and and the tumour markers and , as possible markers for differentiating between CIN3 and normal tissue.
View Article and Find Full Text PDFCureus
November 2024
Research, Siddha Pharmacology, Siddha Central Research Institute, Chennai, IND.
Verrucae vulgaris are infectious keratotic lesions caused by the human papillomavirus (HPV), frequently impairing an individual's quality of life, mainly when situated on the facial region. Verruca vulgaris constitutes a prevalent dermatological issue with diverse repercussions for those affected. The interaction among HPV, the immune system, and treatment methods requires a sophisticated comprehension of this illness.
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