Histone 3.3 participates in a self-sustaining cascade of apoptosis that contributes to the progression of chronic obstructive pulmonary disease

TitleHistone 3.3 participates in a self-sustaining cascade of apoptosis that contributes to the progression of chronic obstructive pulmonary disease
Publication TypeJournal Article
Year of Publication2013
AuthorsBarrero CA, Perez-Leal O, Aksoy M, Moncada C, Ji R, Lopez Y, Mallilankaraman K, Madesh M, Criner GJ, Kelsen SG, Merali S
JournalAm J Respir Crit Care Med
Volume188
Issue6
Pagination673-83
Date Published2013 Sep 15
ISSN1535-4970
KeywordsAcetylation, Apoptosis, Disease Progression, Histones, Humans, In Vitro Techniques, Lung, Pulmonary Disease, Chronic Obstructive
Abstract

RATIONALE: Shifts in the gene expression of nuclear protein in chronic obstructive pulmonary disease (COPD), a progressive disease that is characterized by extensive lung inflammation and apoptosis, are common; however, the extent of the elevation of the core histones, which are the major components of nuclear proteins and their consequences in COPD, has not been characterized, which is important because extracellular histones are cytotoxic to endothelial and airway epithelial cells.

OBJECTIVES: To investigate the role of extracellular histones in COPD disease progression.

METHODS: We analyzed the nuclear lung proteomes of ex-smokers with and without the disease. Further studies on the consequences of H3.3 were also performed.

MEASUREMENTS AND MAIN RESULTS: A striking finding was a COPD-specific eightfold increase of hyperacetylated histone H3.3. The hyperacetylation renders H3.3 resistant to proteasomal degradation despite ubiquitination; when combined with the reduction in proteasome activity that is known for COPD, this resistance helps account for the increased levels of H3.3. Using anti-H3 antibodies, we found H3.3 in the airway lumen, alveolar fluid, and plasma of COPD samples. H3.3 was cytotoxic to lung structural cells via a mechanism that involves the perturbation of Ca(2+) homeostasis and mitochondrial toxicity. We used the primary human airway epithelial cells and found that the antibodies to either the C or N terminus of H3 could partially reverse H3.3 toxicity.

CONCLUSIONS: Our data indicate that there is an uncontrolled positive feedback loop in which the damaged cells release acetylated H3.3, which causes more damage, adds H3.3 release, and contributes toward the disease progression.

DOI10.1164/rccm.201302-0342OC
Alternate JournalAm. J. Respir. Crit. Care Med.
PubMed ID23924319
PubMed Central IDPMC3826185
Grant ListR03-HL095437 / HL / NHLBI NIH HHS / United States
R03-HL095450 / HL / NHLBI NIH HHS / United States
RC2-HL101713 / HL / NHLBI NIH HHS / United States