Cross-talk between KLF4 and STAT3 regulates axon regeneration.
Ontology highlight
ABSTRACT:
SUBMITTER: Qin S
PROVIDER: S-EPMC3867821 | biostudies-literature | 2013
REPOSITORIES: biostudies-literature
Publications
Cross-talk between KLF4 and STAT3 regulates axon regeneration.
Qin Song S Zou Yuhua Y Zhang Chun-Li CL
Nature communications 20130101
Cytokine-induced activation of signal transducer and activator of transcription 3 (STAT3) promotes the regrowth of damaged axons in the adult central nervous system (CNS). Here we show that KLF4 physically interacts with STAT3 upon cytokine-induced phosphorylation of tyrosine 705 (Y705) on STAT3. This interaction suppresses STAT3-dependent gene expression by blocking its DNA-binding activity. The deletion of KLF4 in vivo induces axon regeneration of adult retinal ganglion cells (RGCs) via Janus ...[more]
Similar Datasets
Project description:Axonal regeneration after spinal cord injury (SCI) is intrinsically and extrinsically inhibited by multiple factors. One major factor contributing to intrinsic regeneration failure is the inability of mature neurons in the central nervous system (CNS) to activate regeneration-associated transcription factors (TFs) post-injury. A prior study identified TFs overexpressed in neurons of the peripheral nervous system (PNS) compared to the CNS; some of these could be involved in the ability of PNS neurons to regenerate. Of these, signal transducer and activator of transcription 3 (STAT3), as well its downstream regeneration-associated targets, showed a significant upregulation in PNS neurons relative to CNS neurons, and a constitutively active variant of Stat3 (Stat3CA) promoted neurite growth when expressed in cerebellar neurons (Lerch et al., 2012; Smith et al., 2011). To further enhance STAT3's neurite outgrowth enhancing activity, Stat3CA was fused with a viral activation domain (VP16). VP16 hyperactivates TFs by recruiting transcriptional co-factors to the DNA binding domain (Hirai et al., 2010). Overexpression of this VP16-Stat3CA chimera in primary cortical neurons led to a significant increase of neurite outgrowth as well as Stat3 transcriptional activity in vitro. Furthermore, in vivo transduction of retinal ganglion cells (RGCs) with AAV constructs expressing VP16-Stat3CA resulted in regeneration of optic nerve axons after injury, to a greater degree than for those expressing Stat3CA alone. These findings confirm and extend the concept that overexpression of hyperactivated transcription factors identified as functioning in PNS regeneration can promote axon regeneration in the CNS.
| S-EPMC4888791 | biostudies-literature
Project description:Despite effective antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) are found in nearly one-third of patients. Using a cellular co-culture system including neurons and human microglia infected with HIV (h?glia/HIV), we investigated the hypothesis that HIV-dependent neurological degeneration results from the periodic emergence of HIV from latency within microglial cells in response to neuronal damage or inflammatory signals. When a clonal h?glia/HIV population (HC69) expressing HIV, or HIV infected human primary and iPSC-derived microglial cells, were cultured for a short-term (24 h) with healthy neurons, HIV was silenced. The neuron-dependent induction of latency in HC69 cells was recapitulated using induced pluripotent stem cell (iPSC)-derived GABAergic cortical (iCort) and dopaminergic (iDopaNer), but not motor (iMotorNer), neurons. By contrast, damaged neurons induce HIV expression in latently infected microglial cells. After 48-72 h co-culture, low levels of HIV expression appear to damage neurons, which further enhances HIV expression. There was a marked reduction in intact dendrites staining for microtubule associated protein 2 (MAP2) in the neurons exposed to HIV-expressing microglial cells, indicating extensive dendritic pruning. To model neurotoxicity induced by methamphetamine (METH), we treated cells with nM levels of METH and suboptimal levels of poly (I:C), a TLR3 agonist that mimics the effects of the circulating bacterial rRNA found in HIV infected patients. This combination of agents potently induced HIV expression, with the METH effect mediated by the ?1 receptor (?1R). In co-cultures of HC69 cells with iCort neurons, the combination of METH and poly(I:C) induced HIV expression and dendritic damage beyond levels seen using either agent alone, Thus, our results demonstrate that the cross-talk between healthy neurons and microglia modulates HIV expression, while HIV expression impairs this intrinsic molecular mechanism resulting in the excessive and uncontrolled stimulation of microglia-mediated neurotoxicity.
| S-EPMC6953890 | biostudies-literature
Project description:OBJECTIVE:To investigate the function of discoidin domain receptor 1 (DDR1) in hepatocellular carcinoma (HCC) and to further clarify the underlying mechanism. RESULTS:DDR1 was significantly increased in HCC tissues and cells, which was related to clinical staging and prognosis of HCC. Upregulation of DDR1 promoted EMT and glutamine metabolism in HCC cells, while loss of DDR1 showed the opposite effects. STAT3 bound with the promoter of DDR1, and facilitated the phosphorylation of STAT3. In turn, activation of STAT3 increased the expression of DDR1. Silencing of STAT3 removed the promoting effect of DDR1 on proliferation, migration and invasion of HCC cells. The in vivo tumor growth assay showed that the cross-talk between DDR1 and STAT3 promoted HCC tumorigenesis. CONCLUSIONS:Our research revealed the positive feedback of DDR1 and STAT3 promoted EMT and glutamine metabolism in HCC, which provided some experimental basis for clinical treatment or prevention of HCC. MATERIALS AND METHODS:The mRNA expression of DDR1 was detected by qRT-PCR. CCK8 assay, wound healing assay and transwell assay were used to detect the DDR1/ STAT3 function on proliferation, migration and invasion in HCC cells. Western blot was used to calculate protein level of DDR1, STAT3, epithelial-mesenchymal transition (EMT) related proteins.
| S-EPMC7425490 | biostudies-literature
Project description:ObjectiveT cells and level of the cytokine interferon-γ (IFN-γ) are increased in adipose tissue in obesity. Hedgehog (Hh) signaling has been shown to potently inhibit white adipocyte differentiation. In light of recent findings in neurons that IFN-γ and Hh signaling cross-talk, we examined their potential interaction in the context of adipogenesis.Research design and methodsWe used Hh reporter cells, cell lines, and primary adipocyte differentiation models to explore costimulation of IFN-γ and Hh signaling. Genetic dissection using Ifngr1(-/-) and Stat1(-/-) mouse embryonic fibroblasts, and ultimately, anti-IFN-γ neutralization and expression profiling in obese mice and humans, respectively, were used to place the findings into the in vivo context.ResultsT-cell supernatants directly inhibited hedgehog signaling in reporter and 3T3-L1 cells. Intriguingly, using blocking antibodies, Ifngr1(-/-) and Stat1(-/-) cells, and simultaneous activation of Hh and IFN-γ signaling, we showed that IFN-γ directly suppresses Hh stimulation, thus rescuing adipogenesis. We confirmed our findings using primary mouse and primary human (pre)adipocytes. Importantly, robust opposing signals for Hh and T-cell pathways in obese human adipose expression profiles and IFN-γ depletion in mice identify the system as intact in adipose tissue in vivo.ConclusionsThese results identify a novel antagonistic cross-talk between IFN-γ and Hh signaling in white adipose tissue and demonstrate IFN-γ as a potent inhibitor of Hh signaling.
| S-EPMC3114396 | biostudies-literature
Project description:The Myc bHLH-ZIP transcription factor is deregulated by most cancers. As a heterodimer with the bHLH-ZIP protein Max, Myc regulates target genes that contribute to metabolism and proliferation. This “Myc Network” cross-talks with the “Mlx Network” comprised of the Myc-like bHLH-ZIP proteins MondoA and ChREBP and the Max-like bHLH-ZIP protein Mlx. This “Extended Myc Network” regulates genes with both common and distinct functions. We have generated hepatocytes lacking Mlx (mlxKO) or Mlx+Myc (double KO or DKO) and quantified their abilities to replace dying hepatocytes in a murine model of Type I tyosinemia. We find that this function deteriorates as the Extended Myc Network is progressively dismantled. Genes dysregulated in mlxKO and DKO hepatocytes include those involved in translation and mitochondrial function. The Myc and Mlx Networks thus cross-talk with the latter playing a disproportionate role. mycKO and mlxKO mice also develop age-dependent non-alcoholic fatty liver disease and mlxKO and DKO mice develop extensive hepatic adenomatosis not observed in wild-type, mycKO, chrebpKO or mycKOxchrebpKO mice. In addition to demonstrating cooperation between the Myc and Mlx Networks, this study reveals the latter to be more important in maintaining metabolic and translational homeostasis, while concurrently serving as a suppressor of benign tumorigenesis.
2022-05-05 | GSE181371 | GEO
Project description:The transcription factor STAT3 has been implicated in axon regeneration. Here we investigate a role for STAT3 in sympathetic nerve sprouting after myocardial infarction (MI) - a common injury in humans. We show that NGF stimulates serine phosphorylation (S727) of STAT3 in sympathetic neurons via ERK1/2, in contrast to cytokine phosphorylation of Y705. Maximal sympathetic axon regeneration in vitro requires phosphorylation of both S727 and Y705. Furthermore, cytokine signaling is necessary for NGF-induced sympathetic nerve sprouting in the heart after MI. Transfection studies in neurons lacking STAT3 suggest two independent pools of STAT3, phosphorylated on either S727 or Y705, that regulate sympathetic regeneration via both transcriptional and non-transcriptional means. Additional data identify STAT3-microtubule interactions that may complement the well-characterized role of STAT3 stimulating regeneration associated genes. These data show that STAT3 is critical for sympathetic axon regeneration in vitro and in vivo, and identify a novel non-transcriptional mode of action.
| S-EPMC3791163 | biostudies-literature
Project description:Hyperphosphorylation at the Y705 residue of signal transducer and activator of transcription 3 (STAT3) is implicated in tumorigenesis of leukemia and some solid tumors. However, its role in the development of colorectal cancer is not well defined. To rigorously test the impact of this phosphorylation on colorectal tumorigenesis, we engineered a STAT3 Y705F knock-in to interrupt STAT3 activity in HCT116 and RKO colorectal cancer cells. These STAT3 Y705F mutant cells fail to respond to cytokine stimulation and grow slower than parental cells. These mutant cells are also greatly diminished in their abilities to form colonies in culture, to exhibit anchorage-independent growth in soft agar, and to grow as xenografts in nude mice. These observations strongly support the premise that STAT3 Y705 phosphorylation is crucial in colorectal tumorigenesis. Although it is generally believed that STAT3 functions as a transcription factor, recent studies indicate that transcription-independent functions of STAT3 also play an important role in tumorigenesis. We show here that wild-type STAT3, but not STAT3 Y705F mutant protein, associates with phospholipase C?1 (PLC?1). PLC?1 is a central signal transducer of growth factor and cytokine signaling pathways that are involved in tumorigenesis. In STAT3 Y705F mutant colorectal cancer cells, PLC?1 activity is reduced. Moreover, overexpression of a constitutively active form of PLC?1 rescues the transformation defect of STAT3 Y705F mutant cells. In aggregate, our study identifies previously unknown cross-talk between STAT3 and the PLC? signaling pathways that may play a critical role in colorectal tumorigenesis.
| S-EPMC3196678 | biostudies-literature
Project description:Developmental arrest, a critical component of the life cycle in animals as diverse as nematodes (dauer state), insects (diapause), and vertebrates (hibernation), results in dramatic depression of the metabolic rate and a profound extension in longevity. Although many details of the hormonal systems controlling developmental arrest are well-known, we know little about the interactions between metabolic events and the hormones controlling the arrested state. Here, we show that diapause is regulated by an interplay between blood-borne metabolites and regulatory centers within the brain. Gene expression in the fat body, the insect equivalent of the liver, is strongly suppressed during diapause, resulting in low levels of tricarboxylic acid (TCA) intermediates circulating within the blood, and at diapause termination, the fat body becomes activated, releasing an abundance of TCA intermediates that act on the brain to stimulate synthesis of regulatory peptides that prompt production of the insect growth hormone ecdysone. This model is supported by our success in breaking diapause by injecting a mixture of TCA intermediates and upstream metabolites. The results underscore the importance of cross-talk between the brain and fat body as a regulator of diapause and suggest that the TCA cycle may be a checkpoint for regulating different forms of animal dormancy.
| S-EPMC3437847 | biostudies-other
Project description:Adult stem cells, which exist throughout the body, multiply by cell division to replenish dying cells or to promote regeneration to repair damaged tissues. To perform these functions during the lifetime of organs or tissues, stem cells need to maintain their populations in a faithful distribution of their epigenetic states, which are susceptible to stochastic fluctuations during each cell division, unexpected injury, and potential genetic mutations that occur during many cell divisions. However, it remains unclear how the three processes of differentiation, proliferation, and apoptosis in regulating stem cells collectively manage these challenging tasks. Here, without considering molecular details, we propose a genetic optimal control model for adult stem cell regeneration that includes the three fundamental processes, along with cell division and adaptation based on differential fitnesses of phenotypes. In the model, stem cells with a distribution of epigenetic states are required to maximize expected performance after each cell division. We show that heterogeneous proliferation that depends on the epigenetic states of stem cells can improve the maintenance of stem cell distributions to create balanced populations. A control strategy during each cell division leads to a feedback mechanism involving heterogeneous proliferation that can accelerate regeneration with less fluctuation in the stem cell population. When mutation is allowed, apoptosis evolves to maximize the performance during homeostasis after multiple cell divisions. The overall results highlight the importance of cross-talk between genetic and epigenetic regulation and the performance objectives during homeostasis in shaping a desirable heterogeneous distribution of stem cells in epigenetic states.
| S-EPMC3956188 | biostudies-literature
Project description:Central nervous system (CNS) axons lose their intrinsic ability to regenerate upon maturity, whereas peripheral nervous system (PNS) axons do not. A key difference between these neuronal types is their ability to transport integrins into axons. Integrins can mediate PNS regeneration, but are excluded from adult CNS axons along with their Rab11 carriers. We reasoned that exclusion of the contents of Rab11 vesicles including integrins might contribute to the intrinsic inability of CNS neurons to regenerate, and investigated this by performing laser axotomy. We identify a novel regulator of selective axon transport and regeneration, the ARF6 guanine-nucleotide-exchange factor (GEF) EFA6 (also known as PSD). EFA6 exerts its effects from a location within the axon initial segment (AIS). EFA6 does not localise at the AIS in dorsal root ganglion (DRG) axons, and in these neurons, ARF6 activation is counteracted by an ARF GTPase-activating protein (GAP), which is absent from the CNS, ACAP1. Depleting EFA6 from cortical neurons permits endosomal integrin transport and enhances regeneration, whereas overexpressing EFA6 prevents DRG regeneration. Our results demonstrate that ARF6 is an intrinsic regulator of regenerative capacity, implicating EFA6 as a focal molecule linking the AIS, signalling and transport.This article has an associated First Person interview with the first author of the paper.
| S-EPMC5702059 | biostudies-literature