Most cited article - PubMed ID 26799652
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
Doxorubicin (DOX) is a cytostatic agent belonging to anthracycline group. Important role in mechanism associated with negative effects of DOX plays an oxidative stress. Heat shock proteins (HSPs) are part of mechanisms initiated in response to stressful stimuli and play an important role in cellular responses to oxidative stress through interaction with components of redox signaling. The present work was aimed to study the role of HSPs and autophagy in mechanisms underlying effects of sulforaphane (SFN), a potential activator of Nrf-2, on doxorubicin-induced toxicity in human kidney HEK293 cells. We investigated effects of SFN and DOX on proteins associated with regulation of heat shock response, redox signaling, and autophagy. Results show that SFN significantly reduced cytotoxic effects of DOX. The positive effects of SFN on DOX-induced changes were associated with up-regulation of Nrf-2 and HSP60 protein levels. In the case of another heat shock protein HSP40, SFN increased its levels when was administered alone but not in conditions when cells were exposed to the effects of DOX. Sulforaphane also reversed negative effects of DOX on activities of superoxide dismutases (SODs) and up-regulation of autophagy markers (LC3A/B-II, Atg5, and Atg12). In conclusion, the changes observed in HSP60 are of particular importance in terms of protecting cells from the effects of DOX. Finding that under conditions where SFN reduced cytotoxic effects of DOX were significantly increased protein levels of both Nrf-2 and HSP60 point to the role of HSP60 in mechanisms of redox signaling underlying effects of SFN on DOX-induced toxicity in HEK293 cells. Moreover, data confirmed an important role of autophagy in effects of SFN on DOX-induced toxicity.
- MeSH
- Apoptosis MeSH
- Autophagy MeSH
- Doxorubicin * toxicity MeSH
- HEK293 Cells MeSH
- Humans MeSH
- Oxidative Stress MeSH
- Heat-Shock Proteins * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Doxorubicin * MeSH
- Heat-Shock Proteins * MeSH
- sulforaphane MeSH Browser
With Alzheimer's disease (AD) exhibiting reduced ability of neural stem cell renewal, we hypothesized that de novo mutations controlling embryonic development, in the form of brain somatic mutations instigate the disease. A leading gene presenting heterozygous dominant de novo autism-intellectual disabilities (ID) causing mutations is activity-dependent neuroprotective protein (ADNP), with intact ADNP protecting against AD-tauopathy. We discovered a genomic autism ADNP mutation (c.2188C>T) in postmortem AD olfactory bulbs and hippocampi. RNA-Seq of olfactory bulbs also identified a novel ADNP hotspot mutation, c.2187_2188insA. Altogether, 665 mutations in 596 genes with 441 mutations in AD patients (389 genes, 38% AD-exclusive mutations) and 104 genes presenting disease-causing mutations (OMIM) were discovered. OMIM AD mutated genes converged on cytoskeletal mechanisms, autism and ID causing mutations (about 40% each). The number and average frequencies of AD-related mutations per subject were higher in AD subjects compared to controls. RNA-seq datamining (hippocampus, dorsolateral prefrontal cortex, fusiform gyrus and superior frontal gyrus-583 subjects) yielded similar results. Overlapping all tested brain areas identified unique and shared mutations, with ADNP singled out as a gene associated with autism/ID/AD and presenting several unique aging/AD mutations. The large fusiform gyrus library (117 subjects) with high sequencing coverage correlated the c.2187_2188insA ADNP mutation frequency to Braak stage (tauopathy) and showed more ADNP mutations in AD specimens. In cell cultures, the ADNP-derived snippet NAP inhibited mutated-ADNP-microtubule (MT) toxicity and enhanced Tau-MT association. We propose a paradigm-shifting concept in the perception of AD whereby accumulating mosaic somatic mutations promote brain pathology.
- MeSH
- Alzheimer Disease * genetics MeSH
- Autistic Disorder * genetics MeSH
- Homeodomain Proteins genetics MeSH
- Humans MeSH
- Intellectual Disability * MeSH
- Brain metabolism MeSH
- Mutation MeSH
- Nerve Tissue Proteins genetics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- ADNP protein, human MeSH Browser
- Homeodomain Proteins MeSH
- Nerve Tissue Proteins MeSH
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.
- Keywords
- Autophagosome, LC3, cancer, flux, lysosome, macroautophagy, neurodegeneration, phagophore, stress, vacuole,
- MeSH
- Autophagy * physiology MeSH
- Autophagosomes MeSH
- Biomarkers MeSH
- Biological Assay standards MeSH
- Humans MeSH
- Lysosomes MeSH
- Autophagy-Related Proteins metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Guideline MeSH
- Names of Substances
- Biomarkers MeSH
- Autophagy-Related Proteins MeSH
Cells succumbing to stress via regulated cell death (RCD) can initiate an adaptive immune response associated with immunological memory, provided they display sufficient antigenicity and adjuvanticity. Moreover, multiple intracellular and microenvironmental features determine the propensity of RCD to drive adaptive immunity. Here, we provide an updated operational definition of immunogenic cell death (ICD), discuss the key factors that dictate the ability of dying cells to drive an adaptive immune response, summarize experimental assays that are currently available for the assessment of ICD in vitro and in vivo, and formulate guidelines for their interpretation.
- Keywords
- immunology, molecular biology, oncology,
- MeSH
- Immunogenic Cell Death genetics MeSH
- Consensus MeSH
- Humans MeSH
- Molecular Biology methods MeSH
- Guidelines as Topic MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
There is growing epidemiological evidence indicating an association between diabetes mellitus and the increased incidence of colorectal cancer (CRC). The preferred initial and most widely used pharmacological agent for the treatment of type 2 diabetes is metformin, which in parallel reduces the risk of CRC and improves patient prognosis. AMP-activated protein kinase (AMPK) appears to be tightly associated with the beneficial metabolic effects of metformin, serving as a cellular energy sensor activated in response to a variety of conditions that deplete cellular energy levels. Such conditions include nutrient starvation (particularly glucose), hypoxia and exposure to toxins that inhibit the mitochondrial respiratory chain complex. The aim of the present study was to determine the effect of metformin on CRC cell lines, with different levels of anterior gradient 2 (AGR2) expression, exposed to 5-fluorouracil (5-FU) and oxaliplatin, alone or in combination with metformin. AGR2 has recently emerged as a factor involved in colon carcinogenesis. In AGR2-knockout cells, markedly higher levels of phosphorylated-AMPK were observed in comparison with control cells transfected with GFP-scrambled guide RNA, which indicated that the presence of AGR2 may interfere with the metformin-dependent activation of AMPK. In addition, metformin in combination with 5-FU and oxaliplatin induced ROS production and attenuated autophagy. This effect was enhanced in AGR2-knockout cells.
- Keywords
- AGR2, AMPK, ROS, autophagy, colorectal cancer, diabetes mellitus,
- Publication type
- Journal Article MeSH
These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.
Anterior gradient 2 (AGR2) is a dimeric protein disulfide isomerase family member involved in the regulation of protein quality control in the endoplasmic reticulum (ER). Mouse AGR2 deletion increases intestinal inflammation and promotes the development of inflammatory bowel disease (IBD). Although these biological effects are well established, the underlying molecular mechanisms of AGR2 function toward inflammation remain poorly defined. Here, using a protein-protein interaction screen to identify cellular regulators of AGR2 dimerization, we unveiled specific enhancers, including TMED2, and inhibitors of AGR2 dimerization, that control AGR2 functions. We demonstrate that modulation of AGR2 dimer formation, whether enhancing or inhibiting the process, yields pro-inflammatory phenotypes, through either autophagy-dependent processes or secretion of AGR2, respectively. We also demonstrate that in IBD and specifically in Crohn's disease, the levels of AGR2 dimerization modulators are selectively deregulated, and this correlates with severity of disease. Our study demonstrates that AGR2 dimers act as sensors of ER homeostasis which are disrupted upon ER stress and promote the secretion of AGR2 monomers. The latter might represent systemic alarm signals for pro-inflammatory responses.
- Keywords
- AGR2, TMED2, endoplasmic reticulum, inflammation, proteostasis,
- MeSH
- Endoplasmic Reticulum genetics metabolism MeSH
- HEK293 Cells MeSH
- Proteostasis * MeSH
- Humans MeSH
- Mucoproteins genetics metabolism MeSH
- Protein Multimerization * MeSH
- Mice MeSH
- Oncogene Proteins genetics metabolism MeSH
- Endoplasmic Reticulum Stress * MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- AGR2 protein, human MeSH Browser
- Agr2 protein, mouse MeSH Browser
- Mucoproteins MeSH
- Oncogene Proteins MeSH
Chemoresistance has been found in all malignant tumors including colorectal carcinoma (CRC). Nowadays chemoresistance is understood as a major reason for therapy failure, with consequent tumor growth and spreading leading ultimately to the patient's premature death. The chemotherapy-related resistance of malignant colonocytes may be manifested in diverse mechanisms that may exist both prior to the onset of the therapy or after it. The ultimate function of this chemoresistance is to ensure the survival of malignant cells through continuing adaptation within an organism, therefore, the nature and spectrum of cell-survival strategies in CRC represent a highly significant target of scientific inquiry. Among these survival strategies employed by CRC cells, three unique but significantly linked phenomena stand out-epithelial-to-mesenchymal transition (EMT), autophagy, and cell death. In this mini-review, current knowledge concerning all three mechanisms including their emergence, timeline, regulation, and mutual relationships will be presented and discussed.
- Keywords
- apoptosis, autophagy, chemoresistance, colorectal carcinoma (CRC), epithelial-to-mesenchymal transition (EMT),
- MeSH
- Apoptosis * MeSH
- Autophagy * MeSH
- Drug Resistance, Neoplasm * MeSH
- Epithelial-Mesenchymal Transition * MeSH
- Phenotype MeSH
- Colorectal Neoplasms pathology MeSH
- Humans MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Ageing constitutes the most important risk factor for all major chronic ailments, including malignant, cardiovascular and neurodegenerative diseases. However, behavioural and pharmacological interventions with feasible potential to promote health upon ageing remain rare. Here we report the identification of the flavonoid 4,4'-dimethoxychalcone (DMC) as a natural compound with anti-ageing properties. External DMC administration extends the lifespan of yeast, worms and flies, decelerates senescence of human cell cultures, and protects mice from prolonged myocardial ischaemia. Concomitantly, DMC induces autophagy, which is essential for its cytoprotective effects from yeast to mice. This pro-autophagic response induces a conserved systemic change in metabolism, operates independently of TORC1 signalling and depends on specific GATA transcription factors. Notably, we identify DMC in the plant Angelica keiskei koidzumi, to which longevity- and health-promoting effects are ascribed in Asian traditional medicine. In summary, we have identified and mechanistically characterised the conserved longevity-promoting effects of a natural anti-ageing drug.
- MeSH
- Angelica chemistry MeSH
- Autophagy drug effects MeSH
- Cell Death drug effects MeSH
- Cell Line drug effects MeSH
- Caenorhabditis elegans drug effects MeSH
- Longevity drug effects physiology MeSH
- Drosophila melanogaster drug effects MeSH
- Flavonoids administration & dosage pharmacology MeSH
- Myocardial Ischemia drug therapy MeSH
- Humans MeSH
- Mechanistic Target of Rapamycin Complex 1 metabolism MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- Cation Transport Proteins genetics MeSH
- Gene Expression Regulation drug effects MeSH
- Plant Extracts pharmacology MeSH
- Saccharomyces cerevisiae Proteins genetics MeSH
- Saccharomyces cerevisiae drug effects metabolism MeSH
- Signal Transduction MeSH
- Sirolimus pharmacology MeSH
- Aging drug effects physiology MeSH
- Medicine, East Asian Traditional MeSH
- GATA Transcription Factors drug effects MeSH
- Transcription Factors drug effects genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Flavonoids MeSH
- GLN3 protein, S cerevisiae MeSH Browser
- MEP2 protein, S cerevisiae MeSH Browser
- Mechanistic Target of Rapamycin Complex 1 MeSH
- Cation Transport Proteins MeSH
- Plant Extracts MeSH
- Saccharomyces cerevisiae Proteins MeSH
- Sirolimus MeSH
- GATA Transcription Factors MeSH
- Transcription Factors MeSH
Autophagy is a major catabolic process whereby autophagosomes deliver cytoplasmic content to the lytic compartment for recycling. Autophagosome formation requires two ubiquitin-like systems conjugating Atg12 with Atg5, and Atg8 with lipid phosphatidylethanolamine (PE), respectively. Genetic suppression of these systems causes autophagy-deficient phenotypes with reduced fitness and longevity. We show that Atg5 and the E1-like enzyme, Atg7, are rate-limiting components of Atg8-PE conjugation in Arabidopsis. Overexpression of ATG5 or ATG7 stimulates Atg8 lipidation, autophagosome formation, and autophagic flux. It also induces transcriptional changes opposite to those observed in atg5 and atg7 mutants, favoring stress resistance and growth. As a result, ATG5- or ATG7-overexpressing plants exhibit increased resistance to necrotrophic pathogens and oxidative stress, delayed aging and enhanced growth, seed set, and seed oil content. This work provides an experimental paradigm and mechanistic insight into genetic stimulation of autophagy in planta and shows its efficiency for improving plant productivity.
- MeSH
- Arabidopsis genetics physiology MeSH
- Autophagy-Related Protein 5 genetics metabolism MeSH
- Autophagy genetics MeSH
- Genetic Fitness * MeSH
- Arabidopsis Proteins genetics metabolism MeSH
- Autophagy-Related Protein 8 Family genetics metabolism MeSH
- Signal Transduction genetics MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- APG7 protein, Arabidopsis MeSH Browser
- Atg5 protein, Arabidopsis MeSH Browser
- Autophagy-Related Protein 5 MeSH
- ATG8 protein, Arabidopsis MeSH Browser
- Arabidopsis Proteins MeSH
- Autophagy-Related Protein 8 Family MeSH