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Cannon 2021 Respir Physiol Neurobiol

From Bioblast
Publications in the MiPMap
Cannon DT, Nogueira L, Gutierrez-Gonzalez AK, Gilmore NK, Bigby TD, Breen EC (2021) Role of IL-33 receptor (ST2) deletion in diaphragm contractile and mitochondrial function in the Sugen5416/hypoxia model of pulmonary hypertension. Respir Physiol Neurobiol 295:103783.

» PMID: 34508866 Open Access

Cannon Daniel T, Nogueira Leonardo, Gutierrez-Gonzalez Alma K, Gilmore Natalie K, Bigby Timothy D, Breen Ellen C (2021) Respir Physiol Neurobiol

Abstract: Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature that leads to right ventricular failure. Skeletal muscle maladaptations limit physical activity and may contribute to disease progression. The role of alarmin/inflammatory signaling in PAH respiratory muscle dysfunction is unknown. We hypothesized that diaphragm mitochondrial and contractile functions are impaired in SU5416/hypoxia-induced pulmonary hypertension due to increased systemic IL-33 signaling. We induced pulmonary hypertension in adult C57Bl/6 J (WT) and ST2 (IL1RL1) gene ablated mice by SU5416/hypoxia (SuHx). We measured diaphragm fiber mitochondrial respiration, inflammatory markers, and contractile function ex vivo. SuHx reduced coupled and uncoupled permeabilized myofiber respiration by ∼40 %. During coupled respiration with complex I substrates, ST2-/- attenuated SuHx inhibition of mitochondrial respiration (genotype × treatment interaction F[1,67] = 3.3, p = 0.07, η2 = 0.04). Flux control ratio and coupling efficiency were not affected by SuHx or genotype. A higher substrate control ratio for succinate was observed in SuHx fibers and attenuated in ST2-/- fibers (F[1,67] = 5.3, p < 0.05, η2 = 0.07). Diaphragm TNFα, but not IL-33 or NFkB, was increased in SuHx vs. DMSO in both genotypes (F[1,43] = 4.7, p < 0.05, η2 = 0.1). Diaphragm force-frequency relationships were right-shifted in SuHx vs. WT (F[3,440] = 8.4, p < 0.05, η2 = 0.0025). There was no effect of ST2-/- on the force-frequency relationship. Force decay during a fatigue protocol at 100 Hz, but not at 40 Hz, was attenuated by SuHx vs. DMSO in both genotypes (F[1,41] = 5.6, p < 0.05, η2 = 0.11). SuHx mice exhibit a modest compensation in diaphragm contractility and mitochondrial dysfunction during coupled respiration; the latter partially regulated through ST2 signaling. Keywords: Diaphragm, Mitochondria, Pulmonary hypertension, Respirometry, SU5416 Bioblast editor: Plangger M O2k-Network Lab: US CA San Diego Cannon DT, US CA La Jolla Hogan MC

Labels: MiParea: Respiration  Pathology: Cardiovascular 

Organism: Mouse  Tissue;cell: Skeletal muscle  Preparation: Permeabilized tissue 

Coupling state: LEAK, OXPHOS, ET  Pathway: N, S, NS, ROX  HRR: Oxygraph-2k