Search results for "gene knockdown"
showing 10 items of 174 documents
The Cytoskeletal Adaptor Obscurin-Like 1 Interacts with the Human Papillomavirus 16 (HPV16) Capsid Protein L2 and Is Required for HPV16 Endocytosis.
2016
ABSTRACT The human papillomavirus (HPV) capsid protein L2 is essential for viral entry. To gain a deeper understanding of the role of L2, we searched for novel cellular L2-interacting proteins. A yeast two-hybrid analysis uncovered the actin-depolymerizing factor gelsolin, the membrane glycoprotein dysadherin, the centrosomal protein 68 (Cep68), and the cytoskeletal adaptor protein obscurin-like 1 protein (OBSL1) as putative L2 binding molecules. Pseudovirus (PsV) infection assays identified OBSL1 as a host factor required for gene transduction by three oncogenic human papillomavirus types, HPV16, HPV18, and HPV31. In addition, we detected OBSL1 expression in cervical tissue sections and no…
Nuclear Translocation of RELB Is Increased in Diseased Human Liver and Promotes Ductular Reaction and Biliary Fibrosis in Mice.
2019
Background & Aims Cholangiocyte proliferation and ductular reaction contribute to the onset and progression of liver diseases. Little is known about the role of the transcription factor nuclear factor-κB (NF-κB) in this process. We investigated the activities of the RELB proto-oncogene NF-κB subunit in human cholangiocytes and in mouse models of liver disease characterized by a ductular reaction. Methods We obtained liver tissue samples from patients with primary sclerosing cholangitis, primary biliary cholangitis, hepatitis B or C virus infection, autoimmune hepatitis, alcoholic liver disease, or without these diseases (controls) from a tissue bank in Germany. Tissues were analyzed by immu…
ERK3/MAPK6 controls IL-8 production and chemotaxis
2020
ERK3 is a ubiquitously expressed member of the atypical mitogen activated protein kinases (MAPKs) and the physiological significance of its short half-life remains unclear. By employing gastrointestinal 3D organoids, we detect that ERK3 protein levels steadily decrease during epithelial differentiation. ERK3 is not required for 3D growth of human gastric epithelium. However, ERK3 is stabilized and activated in tumorigenic cells, but deteriorates over time in primary cells in response to lipopolysaccharide (LPS). ERK3 is necessary for production of several cellular factors including interleukin-8 (IL-8), in both, normal and tumorigenic cells. Particularly, ERK3 is critical for AP-1 signaling…
Arrestin-β-1 Physically Scaffolds TSH and IGF1 Receptors to Enable Crosstalk
2019
Endogenously expressed TSH receptors (TSHRs) on orbital fibroblasts of patients with Graves ophthalmopathy (GO) use crosstalk with IGF1 receptors (IGF1R) to synergistically stimulate secretion of hyaluronan (HA), a major component of GO pathology. We previously showed crosstalk occurred upstream of mitogen-activated protein kinase (ERK) phosphorylation. Because other G protein-coupled receptors engage arrestin-β-1 (ARRB1) and ERK, we tested whether ARRB1 was a necessary component of TSHR/IGF1R crosstalk. HA secretion was stimulated by the TSHR-stimulating monoclonal antibodies M22 and KSAb1, or immunoglobulins from patients with GO (GO-Igs). Treatment with M22, as previously shown, resulted…
ESCRT Requirements for Murine Leukemia Virus Release
2016
The Murine Leukemia Virus (MLV) is a gammaretrovirus that hijack host components of the endosomal sorting complex required for transport (ESCRT) for budding. To determine the minimal requirements for ESCRT factors in MLV viral and viral-like particles (VLP) release, an siRNA knockdown screen of ESCRT(-associated) proteins was performed in MLV-producing human cells. We found that MLV VLPs and virions primarily engage the ESCRT-I factor Tsg101 and marginally the ESCRT-associated adaptors Nedd4-1 and Alix to enter the ESCRT pathway. Conversely, the inactivation of ESCRT-II had no impact on VLP and virion egress. By analyzing the effects of individual ESCRT-III knockdowns, VLP and virion releas…
NUPR1, a new target in liver cancer: implication in controlling cell growth, migration, invasion and sorafenib resistance
2016
AbstractSorafenib, an oral multikinase inhibitor, is the only approved agent for the treatment of advanced hepatocellular carcinoma (HCC). However, its benefits are modest, and as its mechanisms of action remain elusive, a better understanding of its anticancer effects is needed. Based on our previous study results, we investigated here the implication of the nuclear protein 1 (NUPR1) in HCC and its role in sorafenib treatment. NUPR1 is a stress-inducible protein that is overexpressed in various malignancies, but its role in HCC is not yet fully understood. We found that NUPR1 expression was significantly higher in primary human HCC samples than in the normal liver. Knockdown of NUPR1 signi…
Targeting aurora kinase B alleviates spinal microgliosis and neuropathic pain in a rat model of peripheral nerve injury.
2019
Peripheral nerve injury elicits spinal microgliosis, contributing to neuropathic pain. The aurora kinases A (AURKA), B (AURKB), and C (AURKC) are potential therapeutic targets in proliferating cells. However, their role has not been clarified in microglia. The aim of this study was to examine the regulation of aurora kinases and their roles and druggability in spinal microgliosis and neuropathic pain. Sprague-Dawley rats received chronic constriction injury (CCI). Gene expression of aurora kinases A-C was evaluated by quantitative RT-PCR and western blot, respectively, in spinal cords at 1, 3, 7, and 14 days after CCI. AURKB gene and protein expression was up-regulated concomitantly with th…
Knockdown of Drosophila hemoglobin suggests a role in O2 homeostasis.
2016
Almost all insects are equipped with a tracheal system, which appears to be sufficient for O2 supply even in phases of high metabolic activity. Therefore, with the exception of a few species dwelling in hypoxic habitats, specialized respiratory proteins had been considered unnecessary in insects. The recent discovery and apparently universal presence of intracellular hemoglobins in insects has remained functionally unexplained. The fruitfly Drosophila melanogaster harbors three different globin genes (referred to as glob1-3). Glob1 is the most highly expressed globin and essentially occurs in the tracheal system and the fat body. To better understand the functions of insect globins, the lev…
Vitellogenin-like A–associated shifts in social cue responsiveness regulate behavioral task specialization in an ant
2018
Division of labor and task specialization explain the success of human and insect societies. Social insect colonies are characterized by division of labor, with workers specializing in brood care early and foraging later in life. Theory posits that this task switching requires shifts in responsiveness to task-related cues, yet experimental evidence is weak. Here, we show that a Vitellogenin (Vg) ortholog identified in an RNAseq study on the ant T. longispinosus is involved in this process: using phylogenetic analyses of Vg and Vg-like genes, we firstly show that this candidate gene does not cluster with the intensively studied honey bee Vg but falls into a separate Vg-like A cluster. Second…
Neuronal Excitability And Spontaneous Synaptic Transmission In The Entorhinal Cortex Of Bdnf Heterozygous Mice
2018
Abstract Brain Derived Neurotropic Factor (BDNF) is a neutrophic factor that is required for the normal neuronal development and function. BDNF is involved in regulation of synapses as well as neuronal excitability. Entorhinal Cortex (EC) is a key brain area involved in many physiological and pathological processes. In this study we investigated the effects of chronically reduced BDNF levels on layer 3 pyramidal neurons of EC. We aimed to assess the effects of reduced levels of BDNF on firing properties, spontaneous synaptic currents and excitation/inhibition balance from acute brain slices. Patch clamp recordings were obtained from pyramidal neurons of Entorhinal Cortex Layer 3. Findings o…