Vascular cell functionality is critical to blood vessel homeostasis. Constitutive NF-κB activation in vascular cells results in chronic vascular inflammation, leading to various cardiovascular diseases. However, how NF-κB regulates human blood vessel homeostasis remains largely elusive. Here, using CRISPR/Cas9-mediated gene editing, we generated RelA knockout human embryonic stem cells (hESCs) and differentiated them into various vascular cell derivatives to study how NF-κB modulates human vascular cells under basal and inflammatory conditions. Multi-dimensional phenotypic assessments and transcriptomic analyses revealed that RelA deficiency affected vascular cells via modulating inflammation, survival, vasculogenesis, cell differentiation and extracellular matrix organization in a cell type-specific manner under basal condition, and that RelA protected vascular cells against apoptosis and modulated vascular inflammatory response upon tumor necrosis factor α (TNFα) stimulation. Lastly, further evaluation of gene expression patterns in IκBα knockout vascular cells demonstrated that IκBα acted largely independent of RelA signaling. Taken together, our data reveal a protective role of NF-κB/RelA in modulating human blood vessel homeostasis and map the human vascular transcriptomic landscapes for the discovery of novel therapeutic targets.
Blood Vessels ; cytology ; metabolism ; CRISPR-Cas Systems ; Embryonic Stem Cells ; cytology ; Gene Knockout Techniques ; Homeostasis ; Humans ; NF-kappa B ; deficiency ; metabolism ; Transcription Factor RelA ; deficiency ; metabolism

Hutchinson-Gilford progeria syndrome (HGPS) and Werner syndrome (WS) are two of the best characterized human progeroid syndromes. HGPS is caused by a point mutation in lamin A (LMNA) gene, resulting in the production of a truncated protein product-progerin. WS is caused by mutations in WRN gene, encoding a loss-of-function RecQ DNA helicase. Here, by gene editing we created isogenic human embryonic stem cells (ESCs) with heterozygous (G608G/+) or homozygous (G608G/G608G) LMNA mutation and biallelic WRN knockout, for modeling HGPS and WS pathogenesis, respectively. While ESCs and endothelial cells (ECs) did not present any features of premature senescence, HGPS- and WS-mesenchymal stem cells (MSCs) showed aging-associated phenotypes with different kinetics. WS-MSCs had early-onset mild premature aging phenotypes while HGPS-MSCs exhibited late-onset acute premature aging characterisitcs. Taken together, our study compares and contrasts the distinct pathologies underpinning the two premature aging disorders, and provides reliable stem-cell based models to identify new therapeutic strategies for pathological and physiological aging.
Aging ; genetics ; physiology ; DNA Helicases ; genetics ; Human Embryonic Stem Cells ; metabolism ; physiology ; Humans ; Kinetics ; Lamin Type A ; genetics ; Mesenchymal Stem Cells ; metabolism ; physiology ; Mutation ; Progeria ; genetics ; physiopathology ; Werner Syndrome ; genetics ; physiopathology

Cell Differentiation ; Humans ; Hyperthermia, Induced ; Stem Cells

Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders, the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown. Here, we report that the expression of 4E-BP1 decreases along with the senescence of human mesenchymal stem cells (hMSCs). Genetic inactivation of 4E-BP1 in hMSCs compromises mitochondrial respiration, increases mitochondrial reactive oxygen species (ROS) production, and accelerates cellular senescence. Mechanistically, the absence of 4E-BP1 destabilizes proteins in mitochondrial respiration complexes, especially several key subunits of complex III including UQCRC2. Ectopic expression of 4E-BP1 attenuates mitochondrial abnormalities and alleviates cellular senescence in 4E-BP1-deficient hMSCs as well as in physiologically aged hMSCs. These f indings together demonstrate that 4E-BP1 functions as a geroprotector to mitigate human stem cell senescence and maintain mitochondrial homeostasis, particularly for the mitochondrial respiration complex III, thus providing a new potential target to counteract human stem cell senescence.
Mesenchymal Stem Cells/physiology* ; Cellular Senescence ; Homeostasis ; Cell Cycle Proteins/metabolism* ; Adaptor Proteins, Signal Transducing/metabolism* ; Mitochondria/metabolism* ; Electron Transport Complex III/metabolism* ; Humans ; Cells, Cultured

Circadian Clocks/genetics* ; Reactive Oxygen Species ; Methionine ; Gastrointestinal Microbiome ; Gastrointestinal Tract ; Racemethionine ; Gene Expression

Humans ; RNA, Long Noncoding/genetics* ; MicroRNAs/genetics* ; Cell Line, Tumor ; Inflammation/genetics* ; Apolipoproteins E ; Apoptosis