Affiliation:
1. Renmin Hospital of Wuhan University: Wuhan University Renmin Hospital
2. Wuhan University
Abstract
Abstract
Activated inflammation and pyroptosis in macrophage are closely
associated with acute lung injury (ALI). Histone deacetylase 3
(HDAC3) serves as an important enzyme that could repress gene
expression by mediating chromatin remodeling. Here, we aim to
explore the role and potential molecular basis of HDAC3 in
lipopolysaccharide (LPS)-induced ALI. We found that HDAC3 was
highly expressed in lung tissues of LPS-treated mice and in
LPS-induced macrophages. Lung tissues from macrophage
HDAC3-deficient mice stimulated with LPS showed alleviative lung
pathological injury and inflammatory response. HDAC3 silence by
small interfering RNA (siRNA) significantly blocked the activation
of cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes
(STING) pathway while HDAC3 overexpression by adenovirus
transfection significantly promoted the activation of cGAS/STING
pathway and aggravated pyroptosis in LPS-induced macrophage.
However, HDAC3 silence or overexpression at baseline showed no
effects on the level of mitochondrial DNA (mt-DNA) and the
activation of cGAS/STING pathway. But HDAC3 at baseline could
change the mRNA and protein levels of cGAS. Additionally, autophagy
or proteasome inhibition in LPS-induced macrophages transfected
with Hdac3 siRNA did not affect the protein level of cGAS.
Mechanistically, cGAS was a direct target gene of miR-4767 in
macrophage. LPS could recruit HDAC3 and H3K9Ac to the miR-4767 gene
promoter, which repressed the expression of miR-4767 by decreasing
histone acetylation of the miR-4767 gene promoter. To this end,
intratracheal administration of liposomes loaded with
Hdac3siRNA prevented mice from LPS-induced lung injury and
inflammation. Taken together, our findings demonstrated that HDAC3
played a pivotal role in mediating pyroptosis in macrophage and ALI
by activating cGAS/STING pathway through decreasing histone
acetylation of the miR-4767 gene promoter. Targeting HDAC3 in
macrophage may provide a new therapeutic target for the prevention
of LPS-induced ALI.
Publisher
Research Square Platform LLC