Search results for " Transgenic"
showing 10 items of 522 documents
Oligodendrocytes control potassium accumulation in white matter and seizure susceptibility
2018
Oligodendrocytes Control Potassium Accumulation in White Matter and Seizure Susceptibility.Larson VA, Mironova Y, Vanderpool KG, Waisman A, Rash JE, Agarwal A, Bergles DE. Elife. 2018 Mar 29;7. pii: e34829. doi: 10.7554/eLife.34829.The inwardly rectifying K+ channel Kir4.1 is broadly expressed by central nervous system glia and deficits in Kir4.1 lead to seizures and myelin vacuolization. However, the role of oligodendrocyte Kir4.1 channels in controlling myelination and K+ clearance in white matter has not been defined. Here, we show that selective deletion of Kir4.1 from oligodendrocyte progenitors or mature oligodendrocytes did not impair their development or disrupt the structure of mye…
Dermal CD207-Negative Migratory Dendritic Cells Are Fully Competent to Prime Protective, Skin Homing Cytotoxic T-Lymphocyte Responses
2018
Dendritic cells (DCs) are important inducers and regulators of T-cell responses. They are able to activate and modulate the differentiation of CD4+ and CD8+ T cells. In the skin, there are at least five phenotypically distinct DC subpopulations that can be distinguished by differential expression of the cell surface markers CD207, CD103, and CD11b. Previous studies have suggested that dermal CD11b−CD207+ conventional type 1 DCs are indispensable for the priming of a skin homing cytotoxic T-lymphocyte response. However, conventional type 1 DCs are also the only skin DC subset capable of cross-presenting exogenous antigens on major histocompatibility complex class I. Thus, it remained unclear…
Selective AhR knockout in langerin-expressing cells abates Langerhans cells and polarizes Th2/Tr1 in epicutaneous protein sensitization
2020
The aryl hydrocarbon receptor (AhR) represents an environmental sensor regulating immune responses. In the skin, AhR is expressed in several cell types, including keratinocytes, epidermal Langerhans cells (LC), and dermal dendritic cells (DC). The mechanisms how AhR activates or inhibits cutaneous immune responses remain controversial, owing to differences in the cell-specific functions of AhR and the different activating ligands. Therefore, we sought to investigate the role of AhR in LC and langerin(+) and negative DC in the skin. To this aim, we generated Langerin-specific and CD11c-specific knockout ((−/−)) mice lacking AhR, respectively, in LC and Langerin(+) dermal DC and in all CD11c(…
GRIP1 Binds to ApoER2 and EphrinB2 to Induce Activity-Dependent AMPA Receptor Insertion at the Synapse
2017
Summary Regulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor trafficking in response to neuronal activity is critical for synaptic function and plasticity. Here, we show that neuronal activity induces the binding of ephrinB2 and ApoER2 receptors at the postsynapse to regulate de novo insertion of AMPA receptors. Mechanistically, the multi-PDZ adaptor glutamate-receptor-interacting protein 1 (GRIP1) binds ApoER2 and bridges a complex including ApoER2, ephrinB2, and AMPA receptors. Phosphorylation of ephrinB2 in a serine residue (Ser-9) is essential for the stability of such a complex. In vivo, a mutation on ephrinB2 Ser-9 in mice results in a complete disruption…
Cannabinoid Control of Learning and Memory through HCN Channels
2016
The mechanisms underlying the effects of cannabinoids on cognitive processes are not understood. Here we show that cannabinoid type-1 receptors (CB1Rs) control hippocampal synaptic plasticity and spatial memory through the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that underlie the h-current (Ih), a key regulator of dendritic excitability. The CB1R-HCN pathway, involving c-Jun-N-terminal kinases (JNKs), nitric oxide synthase, and intracellular cGMP, exerts a tonic enhancement of Ih selectively in pyramidal cells located in the superficial portion of the CA1 pyramidal cell layer, whereas it is absent from deep-layer cells. Activation of the CB1R-HCN pathway impairs d…
CXCR7 Reactivates ERK Signaling to Promote Resistance to EGFR Kinase Inhibitors in NSCLC
2019
Abstract Although EGFR mutant–selective tyrosine kinase inhibitors (TKI) are clinically effective, acquired resistance can occur by reactivating ERK. We show using in vitro models of acquired EGFR TKI resistance with a mesenchymal phenotype that CXCR7, an atypical G protein-coupled receptor, activates the MAPK–ERK pathway via β-arrestin. Depletion of CXCR7 inhibited the MAPK pathway, significantly attenuated EGFR TKI resistance, and resulted in mesenchymal-to-epithelial transition. CXCR7 overexpression was essential in reactivation of ERK1/2 for the generation of EGFR TKI–resistant persister cells. Many patients with non–small cell lung cancer (NSCLC) harboring an EGFR kinase domain mutatio…
NT3/TrkC Pathway Modulates the Expression of UCP-1 and Adipocyte Size in Human and Rodent Adipose Tissue
2021
Neurotrophin-3 (NT3), through activation of its tropomyosin-related kinase receptor C (TrkC), modulates neuronal survival and neural stem cell differentiation. It is widely distributed in peripheral tissues (especially vessels and pancreas) and this ubiquitous pattern suggests a role for NT3, outside the nervous system and related to metabolic functions. The presence of the NT3/TrkC pathway in the adipose tissue (AT) has never been investigated. Present work studies in human and murine adipose tissue (AT) the presence of elements of the NT3/TrkC pathway and its role on lipolysis and adipocyte differentiation. qRT-PCR and immunoblot indicate that NT3 (encoded by NTF3) was present in human re…
Imatinib spares cKit-expressing prostate neuroendocrine tumors, whereas kills seminal vesicle epithelial-stromal tumors by targeting PDGFR-β
2017
Abstract Prostate cancer is a leading cause of cancer-related death in males worldwide. Indeed, advanced and metastatic disease characterized by androgen resistance and often associated with neuroendocrine (NE) differentiation remains incurable. Using the spontaneous prostate cancer TRAMP model, we have shown that mast cells (MCs) support in vivo the growth of prostate adenocarcinoma, whereas their genetic or pharmacologic targeting favors prostate NE cancer arousal. Aiming at simultaneously targeting prostate NE tumor cells and MCs, both expressing the cKit tyrosine kinase receptor, we have tested the therapeutic effect of imatinib in TRAMP mice. Imatinib-treated TRAMP mice experience a pa…
Cross-Talk between Myeloid-Derived Suppressor Cells and Mast Cells Mediates Tumor-Specific Immunosuppression in Prostate Cancer.
2018
Abstract Immunotherapy, including the use of checkpoint inhibitors, is a potent therapeutic approach for some cancers, but has limited success with prostate tumors, in which immune suppression is instigated by the tumor. The immunosuppressive capacity of mast cells, which promote adenocarcinoma development in the prostate, prompted our investigation on whether mast cells promote tolerance to SV40 Large-T antigen, the transforming oncogene in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice. The incidence of adenocarcinoma was reduced in the offspring of a cross between TRAMP mice and mast cell–deficient KitWsh mice. TRAMP mice are tolerant to the SV40 Large T antigen, which is o…
General control non-derepressible 2 (GCN2) in T cells controls disease progression of autoimmune neuroinflammation.
2016
Relapsing-remitting multiple sclerosis (MS)(2) is characterized by phases of acute neuroinflammation followed by spontaneous remission. Termination of inflammation is accompanied by an influx of regulatory T cells (Tregs).(3) The molecular mechanisms responsible for directing Tregs into the inflamed CNS tissue, however, are incompletely understood. In an MS mouse model we show that the stress kinase general control non-derepressible 2 (GCN2),(4) expressed in T cells, contributes to the resolution of autoimmune neuroinflammation. Failure to recover from acute inflammation was associated with reduced frequencies of CNS-infiltrating Tregs. GCN2 deficient Tregs displayed impaired migration to a…