Project description:The decline of endothelial autophagy is closely related to vascular senescence and disease, although the molecular mechanisms connecting these outcomes in vascular endothelial cells (VECs) remain unclear. Here, we identify a crucial role for CD44, a multifunctional adhesion molecule, in controlling autophagy and aging in VECs. The CD44 intercellular domain (CD44ICD) negatively regulates autophagy by reducing PIK3R4 and PIK3C3 levels and disrupting STAT3-dependent PtdIns3K complexes. CD44 and its homologue clec-31 are increased in aging vascular endothelium and Caenorhabditis elegans, respectively, suggesting that an age-dependent increase in CD44 induces autophagy decline and aging phenotypes. Accordingly, CD44 knockdown ameliorates age-associated phenotypes in VECs. The endothelium-specific CD44ICD knock-in mouse is shorter-lived, with VECs exhibiting obvious premature aging characteristics associated with decreased basal autophagy. Autophagy activation suppresses the premature aging of human and mouse VECs overexpressing CD44ICD, function conserved in the CD44 homologue clec-31 in C. elegans. Our work describes a mechanism coordinated by CD44 function bridging autophagy decline and aging.
Project description:The decline of endothelial autophagy is closely related to vascular senescence and disease, although the molecular mechanisms connecting these outcomes in vascular endothelial cells (VECs) remain unclear. Here, we identify a crucial role for CD44, a multifunctional adhesion molecule, in controlling autophagy and ageing in VECs. The CD44 intercellular domain (CD44ICD) negatively regulates autophagy by reducing PIK3R4 and PIK3C3 levels and disrupting STAT3-dependent PtdIns3K complexes. CD44 and its homologue clec-31 are increased in ageing vascular endothelium and Caenorhabditis elegans, respectively, suggesting that an age-dependent increase in CD44 induces autophagy decline and ageing phenotypes. Accordingly, CD44 knockdown ameliorates age-associated phenotypes in VECs. The endothelium-specific CD44ICD knock-in mouse is shorter-lived, with VECs exhibiting obvious premature ageing characteristics associated with decreased basal autophagy. Autophagy activation suppresses the premature ageing of human and mouse VECs overexpressing CD44ICD, function conserved in the CD44 homologue clec-31 in C. elegans. Our work describes a mechanism coordinated by CD44 function bridging autophagy decline and ageing.
Project description:To identify genes that are differentially expressed between CD44+ and CD44- cells in colonospheres, we have employed whole genome microarray expression profiling as a discovery platform. Colonospheres from four colon cancer patients were sorted into CD44+ and CD44- cells using the FACS Aria II Cell Sorter, and total RNA extracted from the cells were labeled with Cy3 and used for microarray analyses with Agilent Whole Human Genome Oligo Microarrays. Gene expression in fluorescence-activated cell-sorted CD44+ and CD44- cells derived from four colon cancer patients was measured.
Project description:To investigate the significance of CD44+ hepatocellular carcinoma (HCC) HuH7 cells, gene expression profiles of CD44-positive HuH7, CD44-negative HuH7, and human nomal hepatocyes were analyzed. Results provide the insight into the significance of CD44-positive HCC cells as the liver CSCs.
Project description:To investigate the significance of CD44+ hepatocellular carcinoma (HCC) HuH7 cells, microRNA (miRNA) expression profiles of CD44-positive HuH7, CD44-negative HuH7, and human nomal hepatocyes were analyzed. Results provide the insight into the significance of CD44-positive HCC cells as the liver CSCs.
Project description:The differentiation of human embryonic stem cells to hematopoietic lineages initiates with the specification of hemogenic endothelium, a transient specialized endothelial precursor of all blood cells.Unfortunately, absence of hemogenic endothelium-specific markers as well as lack of consensus in the timing of hemogenic potential analysis and methodologies used to study the hematopoietic potential of this precursor prevents reaching clear and definite conclusions. Here, we demonstrate that the hemogenic potential of the endothelium precursor population sharply decline over the course of the differentiation process. Poly(A) RNA-sequencing on CD31+CD144+ population at day 6, day 8 and day 10 of EB diffferentiation with or without the addition of cytokines. Comparasion with hematopoietic committed population CD31+CD144- from day 10 of EB differentiation.
Project description:Accumulation of senescent cells affects organismal aging and the prevalence of age-associated disease. Emerging evidence suggests that activation of autophagy protects against age-associated diseases and promotes longevity, but the roles and regulatory mechanisms of autophagy in cellular senescence are not well understood. Here we identified the transcription factor, MondoA, as a novel regulator of cellular senescence, autophagy and mitochondrial homeostasis. MondoA protected against cellular senescence by activating autophagy partly through the suppression of an autophagy negative regulator, Rubicon. In addition, we identified peroxiredoxin 3 (Prdx3) as another downstream regulator of MondoA essential for mitochondrial homeostasis and autophagy. Rubicon and Prdx3 worked independently to regulate senescence. Furthermore, we found that MondoA knockout mice had exacerbated senescence during ischemic acute kidney injury (AKI), and a decrease of MondoA in the nucleus was correlated with human aging and ischemic AKI. Our results suggest that retaining MondoA activity protects from senescence and age-associated disease.
Project description:To identify genes that are differentially expressed between CD44+ and CD44- cells in colonospheres, we have employed whole genome microarray expression profiling as a discovery platform. Colonospheres from four colon cancer patients were sorted into CD44+ and CD44- cells using the FACS Aria II Cell Sorter, and total RNA extracted from the cells were labeled with Cy3 and used for microarray analyses with Agilent Whole Human Genome Oligo Microarrays.