Hydrogen sulfide alleviates hyperoxia effects on mitochondria in human developing airway smooth muscle
Colleen M. Bartman, Michael Thompson, Samantha K. Hamrick, Niyati A. Borkar, Daniel Pfeffer-Kleemann, Preetham Ravi, Marta Schiliro, Yak Nak, Christian Vivar Ramon, Li Drake, Y.S. Prakash, Christina Pabelick
Colleen M. Bartman, Michael Thompson, Samantha K. Hamrick, Niyati A. Borkar, Daniel Pfeffer-Kleemann, Preetham Ravi, Marta Schiliro, Yak Nak, Christian Vivar Ramon, Li Drake, Y.S. Prakash, Christina Pabelick
View: Text | PDF
Research Article Cell biology Pulmonology Therapeutics

Hydrogen sulfide alleviates hyperoxia effects on mitochondria in human developing airway smooth muscle

Abstract

Moderate hyperoxia (30%–60% O2) in premature infants promotes bronchial airway hyperresponsiveness (AHR) via airway smooth muscle (ASM), a key regulator of bronchoconstriction, bronchodilation, and remodeling. Understanding how O2 exposure drives long-term bronchial changes in prematurity is critical for developing therapies for airway disease across the lifespan. Premature lungs have immature antioxidant defenses, potentially due to disrupted mitochondrial dynamics, increasing susceptibility to O2-induced oxidative stress. Thus, mitochondrial homeostasis is highly relevant to ASM dysfunction and airway disease. We propose that hyperoxia in prematurity promotes mitochondrial dysfunction, and that the gasotransmitter hydrogen sulfide (H2S) mitigates O2-induced mitochondrial damage in developing ASM. Human fetal ASM (fASM) cells were exposed to moderate hyperoxia to investigate the effects of exogenous H2S donors (GYY4137, AP39) and stabilization of cystathionine β-synthase (CBS), an H2S biosynthetic enzyme, on mitochondrial structure and function. Hyperoxia impaired fASM cell mitochondrial integrity, while H2S donors in particular, or CBS stabilization attenuated adverse O2 effects on mitochondrial morphology, ROS, respiration, calcium regulation, and contractility. These findings highlight the therapeutic potential of H2S in the premature lung exposed to moderate hyperoxia.

Authors

Colleen M. Bartman, Michael Thompson, Samantha K. Hamrick, Niyati A. Borkar, Daniel Pfeffer-Kleemann, Preetham Ravi, Marta Schiliro, Yak Nak, Christian Vivar Ramon, Li Drake, Y.S. Prakash, Christina Pabelick

×

Figure 4

CBS stabilization via AdoMet attenuates effects of O2 on calcium signaling.

Options: View larger image (or click on image) Download as PowerPoint
CBS stabilization via AdoMet attenuates effects of O2 on calcium signali...
(A) Untransduced fASM cells were exposed to 21% or 40% O2 prior to mitochondrial stress test using a Seahorse Bioanalyzer as described in Figure 3A. Time courses of mitochondrial stress tests. O, oligomycin; F, FCCP = carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone; R/AA, rotenone/antimycin A. (B) Basal respiration and maximal respiration were calculated. Data are represented as fold change from each fASM line control (vehicle in 21% O2). **P < 0.01; ****P < 0.0001 by unpaired t test. Data are represented as mean ± SEM; n = 5 fASM lines/group. (C) Untransduced fASM cells were treated with 1 mM AdoMet or vehicle control and exposed to 21% or 40% O2 for 48 hours prior to live cell fluorescent imaging of [Ca2+]c response to 10 µm histamine (Fura-2/AM). (D) Untransduced fASM cells were treated with 1 mM AdoMet or vehicle control and exposed to 21% or 40% O2 for 48 hours prior to live cell fluorescent imaging of [Ca2+]m response to 10 µm histamine (Rhod-2) and response was calculated between the background-adjusted baseline (background fluorescence subtraction) to maximum peak [Ca2+]m response (F/F0). In C and D, representative tracings are shown (1 from 5–6 fASM lines). *P < 0.05; **P < 0.01 by 2-way ANOVA with Bonferroni’s correction for multiple comparisons (C and D). Data are represented as mean ± SEM; n = 5–6 fASM lines/group.