AKT3
RAC-gamma serine/threonine-protein kinase (EC 2.7.11.1) (Protein kinase Akt-3) (Protein kinase B gamma) (PKB gamma) (RAC-PK-gamma) (STK-2) [PKBG]
Publications[править]
Uterine leiomyomas (ULM) grow under high oxidative stress due to a hypoxic microenvironment and defects in redox metabolism. AKT is one major pathway activated by reactive oxygen species (ROS) that maintains ULM growth and survival. We previously reported that AKT inactivated by AKT inhibitors can significantly induce cellular senescence in ULM cells. Since some miRNAs are induced by AKT inhibitors in an ROS-dependent manner, we proposed that these miRNAs may modulate AKT function and cellular senescence in ULM. We therefore established ex vivo models of a three-dimensional ULM spheroid culture system to study the role of miRNAs in cellular senescence. Four miRNAs, miR-29b, miR-181a, miR-182, and miR-200c, were found to induce cellular senescence in primary ULM and myometrium spheroid cultures when stably overexpressed. miR-181a and miR-182 were found to repress AKT3 and CCND2, respectively. Correspondingly, RNAi of AKT3 or CCND2 also induced cellular senescence and G0/G1 arrest. Thus, miR-181a and miR-182 may drive cellular senescence in ULM by repressing AKT3 and CCND2 activity, respectively. We further demonstrated that senescent ULM cells can be effectively removed by BH3 mimetic ABT263, which provides a new therapeutic venue for the treatment of ULM. Our findings suggest that miRNAs are potent modulators in regulating the ROS-AKT-cell cycle axis in uterine leiomyoma. A subset of oxidative stress-induced miRNAs is involved in AKT signaling in uterine leiomyoma. Overexpression of miR-181a and miR-182 resulted in cellular senescence in leiomyoma through repression of AKT3 and CCND2, respectively. Silencing of AKT3 and CCND2 drives leiomyoma cell into senescence and cycle arrest. Application of our newly developed 3D leiomyoma spheroids can provide a quick and reliable ex vivo model for cytopathologic and functional analysis. BH3 mimetics can effectively reduce the viability of miRNA-mediated senescent cells in leiomyoma.
MeSH Terms
- Cellular Senescence
- Female
- Humans
- Leiomyoma
- MicroRNAs
- Oxidative Stress
- Proto-Oncogene Proteins c-akt
- Signal Transduction
- Uterine Neoplasms
Keywords
- AKT3
- CCND2
- Leiomyoma
- Senescence
- miR-181a
- miR-182
Endothelial progenitor cells (EPCs) play an important role in postnatal neovascularization. The number and function of EPCs declines as part of aging-associated senescence, thereby potentially contributing to vascular pathologies. Here, we investigated the significance and molecular mechanisms of microRNA-22 (miR-22) governing EPC senescence. EPCs were isolated from human circulating mononuclear cells from healthy young and aged volunteers. Cell senescence, proliferation, migration and tube formation ability were detected by SA-β-gal staining assay, MTT assay, transwell assay and Matrigel-based angiogenesis assay. Gene and protein expression were analyzed by qRT-PCR and Western blot respectively. We found that miR-22 was upregulated in aged EPCs. Overexpression of miR-22 in young EPCs induced cell senescence, decreased proliferation and migration, and impaired angiogenesis in vitro. Conversely, silencing of endogenous miR-22 led to decreased cell senescence, increased proliferation and migration, and improved angiogenesis. AKT3 was identified as a direct target of miR-22, and restoration of AKT3 expression attenuated the effects of miR-22 in young EPCs. Our results indicate that miR-22 induces EPC senescence by downregulating AKT3 expression, providing a potential novel target for the reversal of EPC dysfunction in angiogenesis.
MeSH Terms
- Adult
- Aged
- Aging
- Cell Movement
- Cell Proliferation
- Cells, Cultured
- Cellular Senescence
- Down-Regulation
- Endothelial Progenitor Cells
- Humans
- MicroRNAs
- Neovascularization, Pathologic
- Proto-Oncogene Proteins c-akt
- Up-Regulation
- Young Adult
In genome-wide association studies (GWAS) of complex traits, single SNP analysis is still the most applied approach. However, the identified SNPs have small effects and provide limited biological insight. A more appropriate approach to interpret GWAS data of complex traits is to analyze the combined effect of a SNP set grouped per pathway or gene region. We used this approach to study the joint effect on human longevity of genetic variation in two candidate pathways, the insulin/insulin-like growth factor (IGF-1) signaling (IIS) pathway and the telomere maintenance (TM) pathway. For the analyses, we used genotyped GWAS data of 403 unrelated nonagenarians from long-lived sibships collected in the Leiden Longevity Study and 1,670 younger population controls. We analyzed 1,021 SNPs in 68 IIS pathway genes and 88 SNPs in 13 TM pathway genes using four self-contained pathway tests (PLINK set-based test, Global test, GRASS and SNP ratio test). Although we observed small differences between the results of the different pathway tests, they showed consistent significant association of the IIS and TM pathway SNP sets with longevity. Analysis of gene SNP sets from these pathways indicates that the association of the IIS pathway is scattered over several genes (AKT1, AKT3, FOXO4, IGF2, INS, PIK3CA, SGK, SGK2, and YWHAG), while the association of the TM pathway seems to be mainly determined by one gene (POT1). In conclusion, this study shows that genetic variation in genes involved in the IIS and TM pathways is associated with human longevity.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Female
- Genome-Wide Association Study
- Genotype
- Humans
- Insulin
- Insulin-Like Growth Factor I
- Longevity
- Male
- Middle Aged
- Polymorphism, Single Nucleotide
- Signal Transduction
- Telomere