Background:
Increasing evidence suggests that long noncoding RNAs play significant roles in vascular biology and disease development. One such long noncoding RNA,
PSMB8-AS1
, has been implicated in the development of tumors. Nevertheless, the precise role of
PSMB8-AS1
in cardiovascular diseases, particularly atherosclerosis, has not been thoroughly elucidated. Thus, the primary aim of this investigation is to assess the influence of
PSMB8-AS1
on vascular inflammation and the initiation of atherosclerosis.
Methods:
We generated
PSMB8-AS1
knockin and
Apoe
(Apolipoprotein E) knockout mice (
Apoe
−/−
PSMB8-AS1
KI
) and global
Apoe
and proteasome subunit-β type-9 (
Psmb9
) double knockout mice (
Apoe
−/−
Psmb9
−/−
). To explore the roles of
PSMB8-AS1
and
Psmb9
in atherosclerosis, we fed the mice with a Western diet for 12 weeks.
Results:
Long noncoding RNA
PSMB8-AS1
is significantly elevated in human atherosclerotic plaques. Strikingly,
Apoe
−/−
PSMB8-AS1
KI
mice exhibited increased atherosclerosis development, plaque vulnerability, and vascular inflammation compared with
Apoe
−/−
mice. Moreover, the levels of VCAM1 (vascular adhesion molecule 1) and ICAM1 (intracellular adhesion molecule 1) were significantly upregulated in atherosclerotic lesions and serum of
Apoe
−/−
PSMB8-AS1
KI
mice. Consistently, in vitro gain- and loss-of-function studies demonstrated that
PSMB8-AS1
induced monocyte/macrophage adhesion to endothelial cells and increased VCAM1 and ICAM1 levels in a PSMB9-dependent manner. Mechanistic studies revealed that
PSMB8-AS1
induced
PSMB9
transcription by recruiting the transcription factor NONO (non-POU domain-containing octamer-binding protein) and binding to the
PSMB9
promoter. PSMB9 (proteasome subunit-β type-9) elevated VCAM1 and ICAM1 expression via the upregulation of ZEB1 (zinc finger E-box-binding homeobox 1).
Psmb9
deficiency decreased atherosclerotic lesion size, plaque vulnerability, and vascular inflammation in
Apoe
−/−
mice in vivo. Importantly, endothelial overexpression of
PSMB8-AS1
-increased atherosclerosis and vascular inflammation were attenuated by
Psmb9
knockout.
Conclusions:
PSMB8-AS1
promotes vascular inflammation and atherosclerosis via the NONO
/
PSMB9/ZEB1 axis. Our findings support the development of new long noncoding RNA–based strategies to counteract atherosclerotic cardiovascular disease.