The accumulation of irreparable cellular damage restricts healthy lifespan after acute stress or natural aging. Senescent cells are thought to impair tissue function and their genetic clearance can successfully delay features of aging. Identifying how senescent cells avoid apoptosis would allow for the prospective design of anti-senescence compounds to address whether homeostasis can be restored. Here, we identify FOXO4 as a pivot in the maintenance of senescent cell viability. We designed a FOXO4-based peptide which selectively competes for interaction of FOXO4 with p53. In senescent cells, this results in p53 nuclear exclusion and cell-intrinsic apoptosis. Importantly, under conditions where it was well tolerated, the FOXO4 peptide restored liver function after Doxorubicin-induced chemotoxicity. Moreover, in fast aging XpdTTD/TTD, as well as in naturally aged mice the FOXO4 peptide could counteract the loss of fitness, fur density and renal function. Thus, it is possible to therapeutically target senescent cells and thereby effectively counteract senescence-associated loss of tissue homeostasis. Overall design: mRNA expression levels are compared between IR-induced senescent and proliferating IMR90 cells in triplicate
Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging.
Specimen part, Cell line, Subject
View SamplesPrevious reports have shown low vitamin D serum levels and polymorphisms in the vitamin D receptor (VDR) to be associated with increased risk for TB. Given that 1,25-dihydroxyvitamin D3 has a role in lipid metabolism control, we tested whether the link between 1,25-dihydroxyvitamin D3 and tuberculosis involves macrophage lipid metabolism. Since formation of lipid droplets (LD) is a hallmark of lipid dysregulation in M. tuberculosis-infected macrophages, we measured LD content as a readout of altered lipid metabolism in infected THP-1 cells. Induction of LD, which peaked by 24 hours post-infection was prevented by addition of 1,25-dihydroxyvitamin D3 at the time of infection. To investigate the mechanism of 1,25-dihydroxyvitamin D3 modulation of LD formation, we analyzed the transcriptome of M. tuberculosis-infected THP-1 cells with and without 1,25-dihydroxyvitamin D3 treatment.
Cutting edge: Vitamin D regulates lipid metabolism in Mycobacterium tuberculosis infection.
Cell line, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Loss of <i>FAM46C</i> Promotes Cell Survival in Myeloma.
Specimen part, Cell line
View SamplesFAM46C is one of the most recurrently mutated genes in multiple myeloma (MM), however its role in disease pathogenesis is not determined. Here we demonstrate that wild type (WT) FAM46C overexpression induces substantial cytotoxicity in MM cells. In contrast, FAM46C mutations found in MM patients abrogate this cytotoxicity indicating a MM survival advantage conferred by the FAM46C mutant phenotype. WT FAM46C overexpression downregulated IRF4, CEBPB, MYC and upregulated immunoglobulin (Ig) light chain and HSPA5/BIP. Furthermore, pathway analysis suggests that enforced FAM46C expression activates the unfolded protein response (UPR) pathway and induces mitochondrial dysfunction. In contrast, endogenous CRISPR FAM46C depletion enhanced MM cell growth and notably decreasing Ig light chain and BIP expression, activating of ERK and anti-apoptotic signaling and conferring relative resistance to dexamethasone and lenalidomide treatment. The genes altered in FAM46C depleted cells are enriched for signaling pathways regulating estrogen, glucocorticoid, B cell receptor signaling and ATM signaling. Together these results implicate FAM46C in myeloma cell growth and survival. FAM46C mutation contributes to myeloma pathogenesis and disease progression by perturbation in plasma cell differentiation and endoplasmic reticulum homeostasis.
Loss of <i>FAM46C</i> Promotes Cell Survival in Myeloma.
Specimen part, Cell line
View SamplesAutophagy genes play an important role in the T cell activation and proliferation. We examined the role of ATG7 during the process of CD8 T cell memory formation. In the absence of ATG7, antigen-specific CD8 T cells failed to survive past the contraction phase and failed to give rise to memory cells.
Autophagy is essential for effector CD8(+) T cell survival and memory formation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cereblon expression is required for the antimyeloma activity of lenalidomide and pomalidomide.
Cell line
View SamplesThe precise molecular mechanism of action and targets through which thalidomide and related immunomodulatory drugs (IMiDs) exert their anti-tumor effects remains unclear. We investigated the role of cereblon (CRBN), a primary teratogenic target of thalidomide, in the anti-myeloma activity of IMiDs. CRBN depletion is initially cytotoxic to human myeloma cells but surviving cells with stable CRBN depletion become highly resistant to both lenalidomide and pomalidomide, but not to the unrelated drugs bortezomib, dexamethasone and melphalan. Acquired deletion of CRBN was found to be the primary genetic event differentiating isogenic MM1.S cell lines cultured to be sensitive or resistant to lenalidomide and pomalidomide. Gene expression changes induced by lenalidomide were dramatically suppressed in the presence of CRBN depletion further demonstrating that CRBN is required for lenalidomide activity. Downstream targets of CRBN include interferon regulatory factor 4 (IRF4) previously reported to also be a target of lenalidomide. Patients exposed to and putatively resistant to lenalidomide had lower CRBN levels in paired samples before and after therapy. In summary, CRBN is an essential requirement for IMiD activity, and a possible biomarker for the clinical assessment of anti-myeloma efficacy.
Cereblon expression is required for the antimyeloma activity of lenalidomide and pomalidomide.
Cell line
View SamplesType-I (/) and -II () interferons (IFN), through an incompletely understood combination of redundant and unique mechanisms, are essential for host resistance to viral infection. We report a requirement for the Atg5-Atg12/Atg16L1 autophagosome elongation complex in IFN-mediated control of murine norovirus in macrophages. We use microarrays to compare transcriptional changes induced in control and Atg5 deficient macrophages by IFN treatment.
Nondegradative role of Atg5-Atg12/ Atg16L1 autophagy protein complex in antiviral activity of interferon gamma.
Treatment
View SamplesCD70TG mice are a model for sterile chronic immune activation and develop Anemia of Inflammation, which is dependent on the production of Ifng by effector CD4 and CD8 T cells.
Chronic IFN-γ production in mice induces anemia by reducing erythrocyte life span and inhibiting erythropoiesis through an IRF-1/PU.1 axis.
Specimen part
View SamplesThe overarching goal of this study was to explore the antitumor activity of Z-endoxifen, a tamoxifen metabolite, with first-line endocrine therapies tamoxifen and letrozole in the letrozole-sensitive MCF7 aromatase expressing model (MCF7AC1), and with second-line endocrine therapies including tamoxifen, fulvestrant, exemestane, and exemestane plus everolimus, in letrozole-resistant MCF7 model (MCF7LR) in vivo.
Antitumor activity of Z-endoxifen in aromatase inhibitor-sensitive and aromatase inhibitor-resistant estrogen receptor-positive breast cancer.
Cell line, Treatment
View Samples