0000000001314789

AUTHOR

Christof Hiebel

showing 10 related works from this author

Cannabinoid receptor 1 modulates the autophagic flux independent of mTOR- and BECLIN1-complex

2013

Cannabinoid Receptor 1 (CB1) has been initially described as the receptor for Delta-9-Tetrahydrocannabinol in the central nervous system (CNS), mediating retrograde synaptic signaling of the endocannabinoid system. Beside its expression in various CNS regions, CB1 is ubiquituous in peripheral tissues, where it mediates, among other activities, the cell's energy homeostasis. We sought to examine the role of CB1 in the context of the evolutionarily conserved autophagic machinery, a main constituent of the regulation of the intracellular energy status. Manipulating CB1 by siRNA knockdown in mammalian cells caused an elevated autophagic flux, while the expression of autophagy-related genes rema…

Cannabinoid receptorMorpholinesGreen Fluorescent ProteinsDown-RegulationmTORC1NaphthalenesBiochemistryMiceCellular and Molecular NeurosciencePiperidinesReceptor Cannabinoid CB1RimonabantAutophagymedicineAnimalsHumansEnzyme InhibitorsCannabinoid Receptor AntagonistsCells CulturedPI3K/AKT/mTOR pathwayAdenine NucleotidesChemistryTOR Serine-Threonine KinasesAutophagyMembrane ProteinsCalcium Channel BlockersEmbryo MammalianEndocannabinoid systemBenzoxazinesCell biologyMice Inbred C57BLnervous systemAstrocytesPyrazolesBeclin-1lipids (amino acids peptides and proteins)MacrolidesSynaptic signalingRimonabantApoptosis Regulatory ProteinsFlux (metabolism)medicine.drugJournal of Neurochemistry
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BAG3 Proteomic Signature under Proteostasis Stress

2020

The multifunctional HSP70 co-chaperone BAG3 (BCL-2-associated athanogene 3) represents a key player in the quality control of the cellular proteostasis network. In response to stress, BAG3 specifically targets aggregation-prone proteins to the perinuclear aggresome and promotes their degradation via BAG3-mediated selective macroautophagy. To adapt cellular homeostasis to stress, BAG3 modulates and functions in various cellular processes and signaling pathways. Noteworthy, dysfunction and deregulation of BAG3 and its pathway are pathophysiologically linked to myopathies, cancer, and neurodegenerative disorders. Here, we report a BAG3 proteomic signature under proteostasis stress. To elucidat…

ProteomicsautophagyCell signalingCellular homeostasisinteractomeBiologyBAG3InteractomeArticleStress PhysiologicalHumansddc:610Protein Interaction Mapsprotein quality controllcsh:QH301-705.5Adaptor Proteins Signal TransducingProto-Oncogene Proteins c-yesproteostasisBAG3AutophagyMolecular Sequence Annotationstress responseGeneral MedicineCell biologyGene OntologyHEK293 CellsAggresomeProteostasislcsh:Biology (General)Multivariate AnalysisSignal transductionApoptosis Regulatory ProteinsProteasome InhibitorsProtein BindingCells
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Enhanced autophagic-lysosomal activity and increased BAG3-mediated selective macroautophagy as adaptive response of neuronal cells to chronic oxidati…

2019

Oxidative stress and a disturbed cellular protein homeostasis (proteostasis) belong to the most important hallmarks of aging and of neurodegenerative disorders. The proteasomal and autophagic-lysosomal degradation pathways are key measures to maintain proteostasis. Here, we report that hippocampal cells selected for full adaptation and resistance to oxidative stress induced by hydrogen peroxide (oxidative stress-resistant cells, OxSR cells) showed a massive increase in the expression of components of the cellular autophagic-lysosomal network and a significantly higher overall autophagic activity. A comparative expression analysis revealed that distinct key regulators of autophagy are upregu…

0301 basic medicineClinical BiochemistryLFQ Label-free quantificationLETM Leucine zipper and EF-hand containing transmembrane proteinmedicine.disease_causeBiochemistryCHX Cycloheximide0302 clinical medicineBNIP3 Bcl-2 interacting protein 3RAPA RapamycinPIK3C3 Class III PI3‐kinasePhosphorylationlcsh:QH301-705.5Neuronslcsh:R5-920PolyUB PolyubiquitinChemistryBAG3OPA1 Optic atrophy 1TOR Serine-Threonine KinasesWIPI1 WD repeat domain phosphoinositide-interacting protein 1ATG Autophagy relatedTFEB Transcription factor EBCell biologyMitochondriasiRNA Small interfering RNADLP1 Dynamin-like protein 1LAMP1 Lysosomal‐associated membrane protein 1PURO Puromycinlcsh:Medicine (General)Protein homeostasisResearch PaperBafA1 Bafilomycin A1LAMP2 Lysosomal‐associated membrane protein 2Proteasome Endopeptidase ComplexRAB18 Member RAS oncogeneTUB TubulinLC3 Light chain 3 proteinOxidative phosphorylationBAG3CTSD Cathepsin DModels BiologicalCell Line03 medical and health sciencesDownregulation and upregulationMacroautophagymedicineAutophagyHumansAdaptationBAG1 Bcl-2-associated athanogene 1BECN1 Beclin1PI3K/AKT/mTOR pathwayAdaptor Proteins Signal TransducingTEM Transmission electron microscopyHsp70 Heat shock protein 70Organic ChemistryAutophagyAutophagosomesmTOR Mammalian target of rapamycinHsp70Oxidative Stress030104 developmental biologyProteostasislcsh:Biology (General)CV CanavanineBAG3 Bcl-2-associated athanogene 3MTT (3-(45-Dimethylthiazol-2-yl)-25-Diphenyltetrazolium Bromide)Apoptosis Regulatory ProteinsLysosomes030217 neurology & neurosurgeryOxidative stressRedox Biology
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Estrogen receptor α regulates non-canonical autophagy that provides stress resistance to neuroblastoma and breast cancer cells and involves BAG3 func…

2015

AbstractBreast cancer is a heterogeneous disease and approximately 70% of newly diagnosed breast cancers are estrogen receptor (ER) positive. Out of the two ER types, α and β, ERα is the only ER that is detectable by immunohistochemistry in breast cancer biopsies and is the predominant subtype expressed in breast tumor tissue. ER-positive tumors are currently treated with anti-hormone therapy to inhibit ER signaling. It is well known that breast cancer cells can develop endocrine resistance and resistance to anti-hormone therapy and this can be facilitated via the autophagy pathway, but so far the description of a detailed autophagy expression profile of ER-positive cancer cells is missing.…

Cancer ResearchProgrammed cell deathImmunologyEstrogen receptorBreast NeoplasmsBiologyBAG3Cellular and Molecular NeuroscienceNeuroblastomaBreast cancermedicineAutophagyEstrogen Receptor betaHumansPrecision MedicineEstrogen receptor betaPI3K/AKT/mTOR pathwayAdaptor Proteins Signal TransducingEstrogen Replacement TherapyEstrogen Receptor alphaCell Biologymedicine.disease3. Good healthCell biologyGene Expression Regulation NeoplasticCancer cellMCF-7 CellsOriginal ArticleFemaleApoptosis Regulatory ProteinsEstrogen receptor alphaSignal TransductionCell Death & Disease
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The Cleavage Product of Amyloid-β Protein Precursor sAβPPα Modulates BAG3-Dependent Aggresome Formation and Enhances Cellular Proteasomal Activity

2015

Alzheimer's disease (AD) is the major age-associated form of dementia characterized by gradual cognitive decline. Aberrant cleavage of the amyloid-β protein precursor (AβPP) is thought to play an important role in the pathology of this disease. Two principal AβPP processing pathways exist: amyloidogenic cleavage of AβPP resulting in production of the soluble N-terminal fragment sAβPPβ, amyloid-β (Aβ), which accumulates in AD brain, and the AβPP intracellular domain (AICD) sAβPPα, p3 and AICD are generated in the non-amyloidogenic pathway. Prevalence of amyloidogenic versus non-amyloidogenic processing leads to depletion of sAβPPα and an increase in Aβ. Although sAβPPα is a well-accepted neu…

Proteasome Endopeptidase ComplexTime FactorsCell SurvivalLeupeptinsGreen Fluorescent ProteinsCysteine Proteinase InhibitorsProtein degradationProtein aggregationBiologyTransfectionBAG3Rats Sprague-DawleyAmyloid beta-Protein PrecursorAnimalsHumansRNA MessengerRNA Small InterferingProtein precursorCells CulturedAdaptor Proteins Signal TransducingNeuronsAmyloid beta-PeptidesDose-Response Relationship DrugGeneral NeuroscienceHEK 293 cellsBrainGeneral MedicineFibroblastsEmbryo MammalianRatsCell biologyPsychiatry and Mental healthClinical PsychologyHEK293 CellsProteostasisAggresomeGene Expression RegulationBiochemistryProteasomeProteolysisAmyloid Precursor Protein SecretasesGeriatrics and GerontologyApoptosis Regulatory ProteinsJournal of Alzheimer's Disease
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RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy

2014

Macroautophagy is a degradative pathway that sequesters and transports cytosolic cargo in autophagosomes to lysosomes, and its deterioration affects intracellular proteostasis. Membrane dynamics accompanying autophagy are mostly elusive and depend on trafficking processes. RAB GTPase activating proteins (RABGAPs) are important factors for the coordination of cellular vesicle transport systems, and several TBC (TRE2-BUB2-CDC16) domain-containing RABGAPs are associated with autophagy. Employing C. elegans and human primary fibroblasts, we show that RAB3GAP1 and RAB3GAP2, which are components of the TBC domain-free RAB3GAP complex, influence protein aggregation and affect autophagy at basal an…

GTPase-activating proteinlipid dropletsrab3 GTP-Binding ProteinsATG16L1DMSO dimethyl sulfoxideFEZ20302 clinical medicineATG autophagy-relatedPhagosomesDAPI 4’ 6-diamidino-2-phenylindoleSQSTM1 sequestosome 1ATG16L1MAP1LC3 microtubule-associated protein 1 light chain 3GFP green fluorescent protein0303 health sciencesGABARAP GABA(A) receptor-associated proteinGTPase-Activating ProteinsCell biologyRAB3GAP1RAB3GAP2RABGAP RAB GTPase activating proteinATG3autophagyCALCOCO2 calcium binding and coiled-coil domain 2Basic Research PaperseV empty vectorATG8ATG5PBS phosphate-buffered salineBiologyPE phosphatidylethanolamineTBC domain TRE2-BUB2-CDC16 domainBAG3GEF guanine nucleotide exchange factor03 medical and health sciencesC. elegans Caenorhabditis elegansAnimalsHumansCaenorhabditis elegansMolecular Biology030304 developmental biologySirolimusDPH 1 6-diphenyl-1 3 5-hexatrieneproteostasisAutophagyBiological TransportCell BiologyFEZ1Bafi bafilomycin A1FEZ fasciculation and elongation protein zetaNBR1 neighbor of BRCA1 gene 1ProteostasissiRNA small interfering RNABSA bovine serum albuminRabLysosomes030217 neurology & neurosurgeryAutophagy
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The complex modulation of lysosomal degradation pathways by cannabinoid receptors 1 and 2

2015

The two main receptors of the endocannabinoid system, cannabinoid receptors 1 (CB1R) and 2 (CB2R), were described in the early 1990s. Since then, different physiological functions have been revealed that are linked to the activity of these two G-protein-coupled receptors. CB1R and CB2R activities influence signal cascades, which are known to play a role in the regulation of the cellular "self-digestion" process called autophagy. A variety of these signaling pathways are integrated by the mammalian target of rapamycin complex 1 (mTORC1) that acts as an inhibitor of autophagy. Others, like AMP-activated protein kinase dependent signaling pathway, are able to bypass mTORC1 to modulate the auto…

Cannabinoid receptorAutophagyContext (language use)General MedicinemTORC1BiologyEndocannabinoid systemGeneral Biochemistry Genetics and Molecular BiologyCell biologyReceptor Cannabinoid CB2Receptor Cannabinoid CB1AutophagyAnimalsHumansGeneral Pharmacology Toxicology and PharmaceuticsSignal transductionLysosomesProtein kinase AReceptorLife Sciences
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Cannabinoid receptor 1 deficiency in a mouse model of Alzheimer's disease leads to enhanced cognitive impairment despite of a reduction in amyloid de…

2012

Alzheimer's disease (AD) is characterized by amyloid-beta deposition in amyloid plaques, neurofibrillary tangles, inflammation, neuronal loss, and cognitive deficits. Cannabinoids display neuromodulatory and neuroprotective effects and affect memory acquisition. Here, we studied the impact of cannabinoid receptor type 1 (CB1) deficiency on the development of AD pathology by breeding amyloid precursor protein (APP) Swedish mutant mice (APP23), an AD animal model, with CB1-deficient mice. In addition to the lower body weight of APP23/CB1(-/-) mice, most of these mice died at an age before typical AD-associated changes become apparent. The surviving mice showed a reduced amount of APP and its …

Agingmedicine.medical_specialtyPathologyCannabinoid receptormedicine.medical_treatmentMutantMice TransgenicInflammationDiseaseNeuroprotectionAmyloid beta-Protein PrecursorMiceReceptor Cannabinoid CB1Alzheimer DiseaseCell Line TumorInternal medicinemental disordersmedicineAmyloid precursor proteinAnimalsHumansMaze LearningCognitive impairmentAmyloid beta-Peptidesbiologybusiness.industryGeneral NeuroscienceBody WeightAge FactorsBrainPeptide FragmentsDisease Models AnimalEndocrinologyGene Expression RegulationMutationbiology.proteinlipids (amino acids peptides and proteins)MicrogliaNeurology (clinical)CannabinoidGeriatrics and Gerontologymedicine.symptomCognition DisordersbusinessDevelopmental BiologyNeurobiology of Aging
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Arginine Depletion in Combination with Canavanine Supplementation Induces Massive Cell Death in Myeloma Cells By Interfering with Their Protein Metab…

2018

Abstract Introduction Although the therapeutic armamentarium against multiple myeloma has tremendously increased in recent years, it still remains an incurable disease. A highly promising novel anti-tumoral treatment strategy is to target specific non-redundant metabolic achilles heels of individual cancer entities. The semi-essential amino acid arginine can be synthesized from citrulline in most physiological tissues due to expression of the rate-limiting enzyme argininosuccinate synthetase 1 (ASS1). Various tumor entities do not express ASS1, therefore depend on the exogenous availability of arginine and pharmacological approaches to systemically deplete arginine are in phase I-III clinic…

Programmed cell deathArgininebiologyBortezomibChemistryImmunologyArgininosuccinate synthaseCaspase 3Cell BiologyHematologyBiochemistryCell biologychemistry.chemical_compoundCell culturemedicinebiology.proteinCitrullineCanavaninemedicine.drugBlood
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RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy

2015

Macroautophagy is a degradative pathway that sequesters and transports cytosolic cargo in autophagosomes to lysosomes, and its deterioration affects intracellular proteostasis. Membrane dynamics accompanying autophagy are mostly elusive and depend on trafficking processes. RAB GTPase-activating proteins (RABGAPs) are important factors for the coordination of cellular vesicle transport systems, and several TBC (TRE2-BUB2-CDC16) domain-containing RABGAPs are associated with autophagy. Employing C. elegans and human primary fibroblasts, we show that RAB3GAP1 and RAB3GAP2, which are components of the TBC domain-free RAB3GAP complex, influence protein aggregation and affect autophagy at basal an…

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