Hypoxic preconditioning induces epigenetic changes and modifies swine
mesenchymal stem cell angiogenesis and senescence in experimental
atherosclerotic renal artery stenosis.
Authors Isik B, Thaler R, Goksu BB, Conley SM, Al-Khafaji H, Mohan A, Afarideh M,
Abumoawad AM, Zhu XY, Krier JD, Saadiq IM, Tang H, Eirin A, Hickson LJ, van
Wijnen AJ, Textor SC, Lerman LO, Herrmann SM
Submitted By LaTonya Hickson on 5/5/2021
Status Published
Journal Stem cell research & therapy
Year 2021
Date Published
Volume : Pages 12 : 240
PubMed Reference 33853680
Abstract Atherosclerotic renal artery stenosis (ARAS) is a risk factor for ischemic and
hypertensive kidney disease (HKD) for which autologous mesenchymal stem cell
(MSC) appears to be a promising therapy. However, MSCs from ARAS patients
exhibit impaired function, senescence, and DNA damage, possibly due to
epigenetic mechanisms. Hypoxia preconditioning (HPC) exerts beneficial effects
on cellular proliferation, differentiation, and gene and protein expression. We
hypothesized that HPC could influence MSC function and senescence in ARAS by
epigenetic mechanisms and modulating gene expression of chromatin-modifying
enzymes., Adipose-derived MSC harvested from healthy control (N =?8) and ARAS
(N =?8) pigs were cultured under normoxia (20%O2) or hypoxia (1%O2) conditions.
MSC function was assessed by migration, proliferation, and cytokine release in
conditioned media. MSC senescence was evaluated by SA-ß-gal activity. Specific
pro-angiogenic and senescence genes were assessed by reverse transcription
polymerase chain reaction (RT-PCR). Dot blotting was used to measure global
genome 5-hydroxymethylcytosine (5hmC) levels on DNA and Western blotting of
modified histone 3 (H3) proteins to quantify tri-methylated lysine-4 (H3K4me3),
lysine-9 (H3K9me3), and lysine-27 (H3K27me3) residues., Specific pro-angiogenic
genes in ARAS assessed by RT-PCR were lower at baseline but increased under HPC,
while pro-senescence genes were higher in ARAS at baseline as compared healthy
MSCs. ARAS MSCs under basal conditions, displayed higher H3K4me3, H3K27me3, and
5hmC levels compared to healthy MSCs. During HPC, global 5hmC levels were
decreased while no appreciable changes occurred in histone H3 tri-methylation.
ARAS MSCs cultured under HPC had higher migratory and proliferative capacity as
well as increased vascular endothelial growth factor and epidermal growth factor
expression compared to normoxia, and SA-ß-gal activity decreased in both animal
groups., These data demonstrate that swine ARAS MSCs have decreased angiogenesis
and increased senescence compared to healthy MSCs and that HPC mitigates MSC
dysfunction, senescence, and DNA hydroxymethylation in ARAS MSC. Thus, HPC for
MSCs may be considered for their optimization to improve autologous cell therapy
in patients with nephropathies.

Investigators with authorship
LaTonya HicksonMayo Clinic Jacksonville