Viral Insulin/IGF-like Peptides Inhibit IGF-1 Receptor Signaling to Enhance Viral Replication
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PROVIDER: PRJNA1285935 | ENA |
REPOSITORIES: ENA
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Project description:The insulin/IGF system plays a central role in regulating metabolism and growth. We identified viral insulin/IGF1-like peptides (VILPs) in Iridoviridae and investigated their role in host-virus interactions. Using Grouper Iridovirus (GIV) on grouper and zebrafish cells, we show that VILPs are early viral genes and are secreted during infection. VILPs activate insulin receptor (IR) and IGF-1 receptor (IGF1R) phosphorylation and stimulate the PI3K pathway. Supernatants from infected cells trigger dose and time-dependent signaling with GIV-VILP selectively interacts with IGF1R. Functionally, IR inhibition suppresses GIV replication, whereas IGF1R inhibition enhances it, and IGF-1 stimulation reduces replication. During infection, GIV-VILP competes with IGF-1, attenuating IGF1R signaling and reducing proliferation. Transcriptome analysis confirms negative regulation of cell cycle pathways. Using a zebrafish infection model, we demonstrate VILP expression and IGF-1 signaling inhibition. Our findings reveal a viral mimicry mechanism that modulates host IGF-1 signaling to promote viral replication.
2025-07-08 | GSE301660 | GEO
Project description:Human mesenchymal stem cells (MSCs) have demonstrated promise when delivered to damaged tissue or tissue defects for their cytokine secretion and inflammation modulation behaviors that can promote repair. Insulin-like growth factor 1 (IGF-1) has been shown to augment MSCs’ viability and survival and promote their secretion of cytokines that signal to endogenous cells, in the treatment of myocardial infarction, wound healing, and age-related diseases. Biomaterial cell carriers can be functionalized with growth factor-mimetic peptides to enhance MSC function while promoting cell retention and minimizing off-target effects seen with direct administration of soluble growth factors. Here, we functionalized alginate hydrogels with three distinct IGF-1 peptide mimetics and the integrin-binding peptide, cyclic RGD. One IGF-1 peptide mimetic (IGM-3) was found to activate Akt signaling and support survival of serum-deprived MSCs. MSCs encapsulated in alginate hydrogels that presented both IGM-3 and cRGD showed a significant reduction in pro-inflammatory cytokine secretion when challenged with interleukin-1β. Finally, MSCs cultured within the cRGD/IGM-3 hydrogels were able to blunt pro-inflammatory gene expression of human primary cells from degenerated intervertebral discs. These studies indicate the potential to leverage cell adhesive and IGF-1 growth factor peptide mimetics together to control therapeutic secretory behavior of MSCs.
2025-07-16 | GSE275505 | GEO
Project description:Novel factors of viral origin inhibit TOR pathway gene expression
| PRJEB29401 | ENA
Project description:The important role of IGF-1R in cancers has been well established. Classical model involves IGF-1/2 binding to IGF-1R, following activation of the PI3K/Akt pathway, thereby promoting cell proliferation, apoptosis inhibition and treatment resistance. While IGF-1R has become a promising target for cancer therapy, clinical disclosures subsequently have been less encouraging. The question is whether targeting IGF/IGF-1R still holds therapeutic potential. Here we show a novel mechanism that knockdown IGF-1R surprisingly triggers cytoplasmic viral RNA sensors MDA5 and RIG-1, leading to mitochondrial apoptosis in cancer. We analyzed MDA5 and RIG-1 in the intestinal epithelium of IGF-1R knockdown mice. Igf1r+/- mice demonstrated higher MDA5 and RIG-1 than WT mice. IGF-1R knockdown-triggered MDA5 and RIG-1 was further analyzed in human cancer and normal cells. Increased MDA5 and RIG-1 were clearly seen in the cytoplasm identified by immunofluoresce in the cells silenced IGF-1R. Block off IGF-1R downstream PI3K/Akt did not impact on MDA5 and RIG-1 expression. IGF-1R knockdown-triggered MDA5 and RIG-1 and their signaling pathways were similar to those of viral RNA mimetic poly(I:C) had. IGF-1R knockdown-triggered MDA5 and RIG-1 led to cancer apoptosis through activation of the mitochondrial pathway. In vivo assay, Igf1r+/- mice strongly resisted AOM-induced colonic tumorigenesis through triggering MDA¬5- and RIG-1-mediated apoptosis. Notably, RIG-I and MDA5-mediated proapoptotic signaling pathway is preferential active in cancer cells. These data suggest that targeting IGF-1R-triggered MDA5 and RIG-1 might have therapeutic potential for cancer treatment.
2019-11-30 | GSE122534 | GEO
Project description:This study, using a growth hormone (GH)-deficient dwarf animal model and peripheral GH replacement, investigated the effects of circulating IGF-1 during adolescence on IGF-1 levels in the brain. Our results demonstrated that hippocampal IGF-1 protein concentrations during adolescence are highly regulated by circulating IGF-1, which were reduced by GH deficiency and restored by systematic GH replacement. In contrast, IGF-1 levels in the CSF were decreased by GH deficiency but not restored by GH replacement. Furthermore, analysis of gene expression using microarrays and RT-PCR indicated that circulating IGF-1 levels did not modify the transcription of IGF-1 or its receptor in the hippocampus but did regulate genes that are involved in microvascular structure and function, brain development, and synaptic plasticity, which potentially support brain structures involved in cognitive function during this important developmental period.
2011-07-21 | GSE29512 | GEO
Project description:We characterize the different TILs populations reactive against a panel of MHC-I restricted viral peptides using single-molecule-based sequencing technology. They exhibit a stunning diversity in terms of both reactivity and transcriptome profile. This study provides new insights into the correlation between transcriptome markers expressed by these cells and immune specificity to viral epitopes.
2021-04-24 | GSE173165 | GEO
Project description:Blattella germanica Insulin-like Peptides (ILPs)
| PRJEB23932 | ENA
Project description:Gametogenesis involves active protein synthesis and heavily relies on proteostasis. How animals regulate germline proteostasis at the organismal level is poorly understood. Our recent work in C. elegans indicates that germline development requires coordinated activities between insulin/IGF-1 signaling and HSF-1, the transcriptional activator of many molecular chaperones in stress and physiological conditions. In this study, we show that HSF-1 is important for germline proteostasis at ambient temperature. Depletion of HSF-1 from germ cells impairs chaperone gene expression, causing protein degradation and aggregation and, consequently, declines in fecundity and gamete quality. Reduced insulin/IGF-1 signaling confers germ cells' tolerance to limited protein folding capacity and proteotoxic stress by lowering ribosome biogenesis and translation. Interestingly, regulation of germline proteostasis by insulin/IGF-1 signaling occurs non-cell-autonomously. Our data suggest that insulin/IGF-1 signaling controls the expression of the evolutionarily conserved intestinal peptide transporter PEPT-1 via its downstream transcription factor FOXO/DAF-16, therefore allowing dietary proteins to be incorporated into an amino acid pool that fuels ribosomal biogenesis and translation in the germline. We propose that this pathway plays a critical role in regulating germline protein synthesis, which must be at balance with HSF-1-dependent protein folding to achieve proteostasis in gametogenesis.
2024-05-20 | GSE256186 | GEO
Project description:This study, using a growth hormone (GH)-deficient dwarf animal model and peripheral GH replacement, investigated the effects of circulating IGF-1 during adolescence on IGF-1 levels in the brain. Our results demonstrated that hippocampal IGF-1 protein concentrations during adolescence are highly regulated by circulating IGF-1, which were reduced by GH deficiency and restored by systematic GH replacement. In contrast, IGF-1 levels in the CSF were decreased by GH deficiency but not restored by GH replacement. Furthermore, analysis of gene expression using microarrays and RT-PCR indicated that circulating IGF-1 levels did not modify the transcription of IGF-1 or its receptor in the hippocampus but did regulate genes that are involved in microvascular structure and function, brain development, and synaptic plasticity, which potentially support brain structures involved in cognitive function during this important developmental period. GH-deficient dwarf (dw/dw) and heterozygous (HZ) rats were identified at postnatal day 33-34. Starting from d35, dw/dw rats received subcutaneous injection of either 300µg GH (dw/dw+GH) or saline (dw/dw+sal) for 7d or 30d. HZ animals received saline for the same periods as controls. Animals (n=4/group for each time point) were sacrificed, the hippocampi were dissected, and total RNA were isolated for subsequent transcriptomic profiling.
2011-07-20 | E-GEOD-29512 | biostudies-arrayexpress
Project description:Viruses are the most abundant biological entities and carry a wide variety of genetic material, including the ability to encode host-like proteins. Here we show that viruses carry sequences with significant homology to several human peptide hormones including insulin, insulin-like growth factors (IGF)-1 and -2, FGF-19 and -21, endothelin-1, inhibin, adiponectin, and resistin. Among the strongest homologies were those for four viral insulin/IGF-1-like peptides (VILPs), each encoded by a different member of the family Iridoviridae VILPs show up to 50% homology to human insulin/IGF-1, contain all critical cysteine residues, and are predicted to form similar 3D structures. Chemically synthesized VILPs can bind to human and murine IGF-1/insulin receptors and stimulate receptor autophosphorylation and downstream signaling. VILPs can also increase glucose uptake in adipocytes and stimulate the proliferation of fibroblasts, and injection of VILPs into mice significantly lowers blood glucose. Transfection of mouse hepatocytes with DNA encoding a VILP also stimulates insulin/IGF-1 signaling and DNA synthesis. Human microbiome studies reveal the presence of these Iridoviridae in blood and fecal samples. Thus, VILPs are members of the insulin/IGF superfamily with the ability to be active on human and rodent cells, raising the possibility for a potential role of VILPs in human disease. Furthermore, since only 2% of viruses have been sequenced, this study raises the potential for discovery of other viral hormones which, along with known virally encoded growth factors, may modify human health and disease.
| S-EPMC5877943 | biostudies-literature