1
|
Balczon R, Lin MT, Voth S, Nelson AR, Schupp JC, Wagener BM, Pittet JF, Stevens T. Lung endothelium, tau, and amyloids in health and disease. Physiol Rev 2024; 104:533-587. [PMID: 37561137 PMCID: PMC11281824 DOI: 10.1152/physrev.00006.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 06/26/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023] Open
Abstract
Lung endothelia in the arteries, capillaries, and veins are heterogeneous in structure and function. Lung capillaries in particular represent a unique vascular niche, with a thin yet highly restrictive alveolar-capillary barrier that optimizes gas exchange. Capillary endothelium surveys the blood while simultaneously interpreting cues initiated within the alveolus and communicated via immediately adjacent type I and type II epithelial cells, fibroblasts, and pericytes. This cell-cell communication is necessary to coordinate the immune response to lower respiratory tract infection. Recent discoveries identify an important role for the microtubule-associated protein tau that is expressed in lung capillary endothelia in the host-pathogen interaction. This endothelial tau stabilizes microtubules necessary for barrier integrity, yet infection drives production of cytotoxic tau variants that are released into the airways and circulation, where they contribute to end-organ dysfunction. Similarly, beta-amyloid is produced during infection. Beta-amyloid has antimicrobial activity, but during infection it can acquire cytotoxic activity that is deleterious to the host. The production and function of these cytotoxic tau and amyloid variants are the subject of this review. Lung-derived cytotoxic tau and amyloid variants are a recently discovered mechanism of end-organ dysfunction, including neurocognitive dysfunction, during and in the aftermath of infection.
Collapse
Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Mike T Lin
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Sarah Voth
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Monroe, Louisiana, United States
| | - Amy R Nelson
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Jonas C Schupp
- Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University, New Haven, Connecticut, United States
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- German Center for Lung Research (DZL), Hannover, Germany
| | - Brant M Wagener
- Department of Anesthesiology and Perioperative Medicine, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| |
Collapse
|
2
|
Gwin MS, Alexeyev MF, Geurts AM, Lee JY, Zhou C, Yang XM, Cohen MV, Downey JM, Barrington RA, Spadafora D, Audia JP, Frank DW, Voth S, Pastukh VV, Bell J, Ayers L, Tambe DT, Nelson AR, Balczon R, Lin MT, Stevens T. Gamma secretase activating protein promotes end-organ dysfunction after bacterial pneumonia. Am J Physiol Lung Cell Mol Physiol 2023; 325:L174-L189. [PMID: 37366533 PMCID: PMC10396227 DOI: 10.1152/ajplung.00018.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 06/28/2023] Open
Abstract
Pneumonia elicits the production of cytotoxic beta amyloid (Aβ) that contributes to end-organ dysfunction, yet the mechanism(s) linking infection to activation of the amyloidogenic pathway that produces cytotoxic Aβ is unknown. Here, we tested the hypothesis that gamma-secretase activating protein (GSAP), which contributes to the amyloidogenic pathway in the brain, promotes end-organ dysfunction following bacterial pneumonia. First-in-kind Gsap knockout rats were generated. Wild-type and knockout rats possessed similar body weights, organ weights, circulating blood cell counts, arterial blood gases, and cardiac indices at baseline. Intratracheal Pseudomonas aeruginosa infection caused acute lung injury and a hyperdynamic circulatory state. Whereas infection led to arterial hypoxemia in wild-type rats, the alveolar-capillary barrier integrity was preserved in Gsap knockout rats. Infection potentiated myocardial infarction following ischemia-reperfusion injury, and this potentiation was abolished in knockout rats. In the hippocampus, GSAP contributed to both pre- and postsynaptic neurotransmission, increasing the presynaptic action potential recruitment, decreasing neurotransmitter release probability, decreasing the postsynaptic response, and preventing postsynaptic hyperexcitability, resulting in greater early long-term potentiation but reduced late long-term potentiation. Infection abolished early and late long-term potentiation in wild-type rats, whereas the late long-term potentiation was partially preserved in Gsap knockout rats. Furthermore, hippocampi from knockout rats, and both the wild-type and knockout rats following infection, exhibited a GSAP-dependent increase in neurotransmitter release probability and postsynaptic hyperexcitability. These results elucidate an unappreciated role for GSAP in innate immunity and highlight the contribution of GSAP to end-organ dysfunction during infection.NEW & NOTEWORTHY Pneumonia is a common cause of end-organ dysfunction, both during and in the aftermath of infection. In particular, pneumonia is a common cause of lung injury, increased risk of myocardial infarction, and neurocognitive dysfunction, although the mechanisms responsible for such increased risk are unknown. Here, we reveal that gamma-secretase activating protein, which contributes to the amyloidogenic pathway, is important for end-organ dysfunction following infection.
Collapse
Affiliation(s)
- Meredith S Gwin
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Mikhail F Alexeyev
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Ji Young Lee
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Chun Zhou
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Xi-Ming Yang
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Michael V Cohen
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - James M Downey
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Robert A Barrington
- Department of Microbiology and Immunology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Domenico Spadafora
- Department of Microbiology and Immunology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Jonathon P Audia
- Department of Microbiology and Immunology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Dara W Frank
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Sarah Voth
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Monroe, Louisiana, United States
| | - Viktoriya V Pastukh
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Jessica Bell
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Linn Ayers
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Dhananjay T Tambe
- Department of Mechanical, Aerospace, and Biomedical Engineering, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Amy R Nelson
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Ron Balczon
- Department of Biochemistry and Molecular Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Mike T Lin
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Troy Stevens
- Department of Physiology and Cell Biology, Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| |
Collapse
|
3
|
Cytotoxic tau released from lung microvascular endothelial cells upon infection with Pseudomonas aeruginosa promotes neuronal tauopathy. J Biol Chem 2021; 298:101482. [PMID: 34896150 PMCID: PMC8718960 DOI: 10.1016/j.jbc.2021.101482] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 11/23/2022] Open
Abstract
Patients who recover from nosocomial pneumonia oftentimes exhibit long-lasting cognitive impairment comparable with what is observed in Alzheimer’s disease patients. We previously hypothesized that the lung endothelium contributes to infection-related neurocognitive dysfunction, because bacteria-exposed endothelial cells release a form(s) of cytotoxic tau that is sufficient to impair long-term potentiation in the hippocampus. However, the full-length lung and endothelial tau isoform(s) have yet to be resolved and it remains unclear whether the infection-induced endothelial cytotoxic tau triggers neuronal tau aggregation. Here, we demonstrate that lung endothelial cells express a big tau isoform and three additional tau isoforms that are similar to neuronal tau, each containing four microtubule-binding repeat domains, and that tau is expressed in lung capillaries in vivo. To test whether infection elicits endothelial tau capable of causing transmissible tau aggregation, the cells were infected with Pseudomonas aeruginosa. The infection-induced tau released from endothelium into the medium-induced neuronal tau aggregation in reporter cells, including reporter cells that express either the four microtubule-binding repeat domains or the full-length tau. Infection-induced release of pathological tau variant(s) from endothelium, and the ability of the endothelial-derived tau to cause neuronal tau aggregation, was abolished in tau knockout cells. After bacterial lung infection, brain homogenates from WT mice, but not from tau knockout mice, initiated tau aggregation. Thus, we conclude that bacterial pneumonia initiates the release of lung endothelial-derived cytotoxic tau, which is capable of propagating a neuronal tauopathy.
Collapse
|