scholarly journals Mitochondrial dysfunction, UPRmt signaling, and targeted therapy in metastasis tumor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rajendiran Keerthiga ◽  
De-Sheng Pei ◽  
Ailing Fu
Keyword(s):  
Targeted Therapy ◽  
Mitochondrial Dysfunction ◽  
Tumor Cells ◽  
Hypoxia Inducible Factor ◽  
Retrograde Signaling ◽  
Protein Accumulation ◽  
Mtdna Mutation ◽  
Unfolded Protein ◽  
Denatured Protein ◽  
Activating Transcription Factor

AbstractIn modern research, mitochondria are considered a more crucial energy plant in cells. Mitochondrial dysfunction, including mitochondrial DNA (mtDNA) mutation and denatured protein accumulation, is a common feature of tumors. The dysfunctional mitochondria reprogram molecular metabolism and allow tumor cells to proliferate in the hostile microenvironment. One of the crucial signaling pathways of the mitochondrial dysfunction activation in the tumor cells is the retrograde signaling of mitochondria-nucleus interaction, mitochondrial unfolded protein response (UPRmt), which is initiated by accumulation of denatured protein and excess ROS production. In the process of UPRmt, various components are activitated to enhance the mitochondria-nucleus retrograde signaling to promote carcinoma progression, including hypoxia-inducible factor (HIF), activating transcription factor ATF-4, ATF-5, CHOP, AKT, AMPK. The retrograde signaling molecules of overexpression ATF-5, SIRT3, CREB, SOD1, SOD2, early growth response protein 1 (EGR1), ATF2, CCAAT/enhancer-binding protein-d, and CHOP also involved in the process. Targeted blockage of the UPRmt pathway could obviously inhibit tumor proliferation and metastasis. This review indicates the UPRmt pathways and its crucial role in targeted therapy of metastasis tumors.

Endoplasmic reticulum stress signal impairs erythropoietin production: a role for ATF4

2013 ◽  
Vol 304 (4) ◽  
pp. C342-C353 ◽  
Author(s):  
Chih-Kang Chiang ◽  
Masaomi Nangaku ◽  
Tetsuhiro Tanaka ◽  
Takao Iwawaki ◽  
Reiko Inagi
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Transcriptional Activity ◽  
Target Genes ◽  
Hypoxia Inducible Factor ◽  
Enhancer Activity ◽  
Unfolded Protein ◽  
Stress Signal ◽  
Liver And Kidney ◽  
Activating Transcription Factor

Hypoxia upregulates the hypoxia-inducible factor (HIF) pathway and the endoplasmic reticulum (ER) stress signal, unfolded protein response (UPR). The cross talk of both signals affects the pathogenic alteration by hypoxia. Here we showed that ER stress induced by tunicamycin or thapsigargin suppressed inducible (CoCl2or hypoxia) transcription of erythropoietin (EPO), a representative HIF target gene, in HepG2. This suppression was inversely correlated with UPR activation, as estimated by expression of the UPR regulator glucose-regulated protein 78, and restored by an ER stress inhibitor, salubrinal, in association with normalization of the UPR state. Importantly, the decreased EPO expression was also observed in HepG2 overexpressing UPR activating transcription factor (ATF)4. Overexpression of mutated ATF4 that lacks the transcriptional activity did not alter EPO transcriptional regulation. Transcriptional activity of the EPO 3′-enhancer, which is mainly regulated by HIF, was abolished by both ER stressors and ATF4 overexpression, while nuclear HIF accumulation or expression of other HIF target genes was not suppressed by ER stress. Chromatin immunoprecipitation analysis identified a novel ATF4 binding site (TGACCTCT) within the EPO 3′-enhancer region, suggesting a distinct role for ATF4 in UPR-dependent suppression of the enhancer. Induction of ER stress in rat liver and kidney by tunicamycin decreased the hepatic and renal mRNA and plasma level of EPO. Collectively, ER stress selectively impairs the transcriptional activity of EPO but not of other HIF target genes. This effect is mediated by suppression of EPO 3′-enhancer activity via ATF4 without any direct effect on HIF, indicating that UPR contributes to oxygen-sensing regulation of EPO.

scholarly journals Role of the mitochondrial stress response in human cancer progression

2020 ◽  
Vol 245 (10) ◽  
pp. 861-878 ◽  
Author(s):  
Sheng-Fan Wang ◽  
Shiuan Chen ◽  
Ling-Ming Tseng ◽  
Hsin-Chen Lee
Keyword(s):  
Stress Response ◽  
Mitochondrial Dysfunction ◽  
Cancer Progression ◽  
Stress Responses ◽  
Retrograde Signaling ◽  
Cancer Targeting ◽  
Mitochondrial Stress ◽  
Unfolded Protein ◽  
Protein Response ◽  
Mitochondrial Unfolded Protein Response

Mitochondria are important organelles that are responsible for cellular energy metabolism, cellular redox/calcium homeostasis, and cell death regulation in mammalian cells. Mitochondrial dysfunction is involved in various diseases, such as neurodegenerative diseases, cardiovascular diseases, immune disorders, and cancer. Defective mitochondria and metabolism remodeling are common characteristics in cancer cells. Several factors, such as mitochondrial DNA copy number changes, mitochondrial DNA mutations, mitochondrial enzyme defects, and mitochondrial dynamic changes, may contribute to mitochondrial dysfunction in cancer cells. Some lines of evidence have shown that mitochondrial dysfunction may promote cancer progression. Here, several mitochondrial stress responses, including the mitochondrial unfolded protein response and the integrated stress response, and several mitochondrion-derived molecules (reactive oxygen species, calcium, oncometabolites, and others) are reviewed; these pathways and molecules are considered to act as retrograde signaling regulators in the development and progression of cancer. Targeting these components of the mitochondrial stress response may be an important strategy for cancer treatment. Impact statement Dysregulated mitochondria often occurred in cancers. Mitochondrial dysfunction might contribute to cancer progression. We reviewed several mitochondrial stresses in cancers. Mitochondrial stress responses might contribute to cancer progression. Several mitochondrion-derived molecules (ROS, Ca2+, oncometabolites, exported mtDNA, mitochondrial double-stranded RNA, humanin, and MOTS-c), integrated stress response, and mitochondrial unfolded protein response act as retrograde signaling pathways and might be critical in the development and progression of cancer. Targeting these mitochondrial stress responses may be an important strategy for cancer treatment.

scholarly journals Mitochondrial retrograde signaling regulates neuronal function

2015 ◽  
Vol 112 (44) ◽  
pp. E6000-E6009 ◽  
Author(s):  
Umut Cagin ◽  
Olivia F. Duncan ◽  
Ariana P. Gatt ◽  
Marc S. Dionne ◽  
Sean T. Sweeney ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
Hypoxia Inducible Factor ◽  
Leigh Syndrome ◽  
Retrograde Signaling ◽  
Neuronal Function ◽  
Mitochondrial Retrograde Signaling ◽  
Factor Alpha ◽  
Familial Parkinson’S Disease ◽  
Mitochondrial Defect

Mitochondria are key regulators of cellular homeostasis, and mitochondrial dysfunction is strongly linked to neurodegenerative diseases, including Alzheimer’s and Parkinson’s. Mitochondria communicate their bioenergetic status to the cell via mitochondrial retrograde signaling. To investigate the role of mitochondrial retrograde signaling in neurons, we induced mitochondrial dysfunction in the Drosophila nervous system. Neuronal mitochondrial dysfunction causes reduced viability, defects in neuronal function, decreased redox potential, and reduced numbers of presynaptic mitochondria and active zones. We find that neuronal mitochondrial dysfunction stimulates a retrograde signaling response that controls the expression of several hundred nuclear genes. We show that the Drosophila hypoxia inducible factor alpha (HIFα) ortholog Similar (Sima) regulates the expression of several of these retrograde genes, suggesting that Sima mediates mitochondrial retrograde signaling. Remarkably, knockdown of Sima restores neuronal function without affecting the primary mitochondrial defect, demonstrating that mitochondrial retrograde signaling is partly responsible for neuronal dysfunction. Sima knockdown also restores function in a Drosophila model of the mitochondrial disease Leigh syndrome and in a Drosophila model of familial Parkinson’s disease. Thus, mitochondrial retrograde signaling regulates neuronal activity and can be manipulated to enhance neuronal function, despite mitochondrial impairment.

scholarly journals IRE1 Alpha/XBP1 Axis Sustains Primary Effusion Lymphoma Cell Survival by Promoting Cytokine Release and STAT3 Activation

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 118
Author(s):  
Roberta Gonnella ◽  
Maria Saveria Gilardini Montani ◽  
Luisa Guttieri ◽  
Maria Anele Romeo ◽  
Roberta Santarelli ◽  
...  
Keyword(s):  
Primary Effusion Lymphoma ◽  
B Cell Lymphoma ◽  
Vascular Endothelial ◽  
Unfolded Protein ◽  
Oncogenic Pathways ◽  
Activating Transcription Factor ◽  
High Level ◽  
Protein Response ◽  
Endothelial Growth Factor ◽  
Constitutive Phosphorylation

Primary Effusion Lymphoma (PEL) is a highly aggressive B cell lymphoma associated with Kaposi’s Sarcoma-associated Herpesvirus (KSHV). It is characterized by a high level of basal Endoplasmic Reticulum (ER) stress, Unfolded Protein Response (UPR) activation and constitutive phosphorylation of oncogenic pathways such as the Signal Transducer and activator of Transcription (STAT3). In this study, we found that the inositol requiring kinase (IRE) 1alpha/X-box binding protein (XBP1) axis of UPR plays a key role in the survival of PEL cells, while double stranded RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor (ATF) 6 slightly influence it, in correlation with the capacity of the IRE1alpha/XBP1 axis to induce the release of interleukin (IL)-6, IL-10 and Vascular-Endothelial Growth Factor (VEGF). Moreover, we found that IRE1alpha/XBP1 inhibition reduced STAT3 Tyr705 phosphorylation and induced a pro-survival autophagy in PEL cells. In conclusion, this study suggests that targeting the IRE1alpha/XBP1 axis represents a promising strategy against PEL cells and that the cytotoxic effect of this treatment may be potentiated by autophagy inhibition.

The biochemistry and cell biology of aging: metabolic regulation through mitochondrial signaling

2014 ◽  
Vol 306 (6) ◽  
pp. E581-E591 ◽  
Author(s):  
Yun Chau Long ◽  
Theresa May Chin Tan ◽  
Inoue Takao ◽  
Bor Luen Tang
Keyword(s):  
Cell Biology ◽  
Metabolic Regulation ◽  
Nutrient Sensing ◽  
Cellular Aging ◽  
Retrograde Signaling ◽  
Unfolded Protein ◽  
Mitochondrial Retrograde Signaling ◽  
Long Time ◽  
Biology Of Aging ◽  
Protein Response

Cellular and organ metabolism affects organismal lifespan. Aging is characterized by increased risks for metabolic disorders, with age-associated degenerative diseases exhibiting varying degrees of mitochondrial dysfunction. The traditional view of the role of mitochondria generated reactive oxygen species (ROS) in cellular aging, assumed to be causative and simply detrimental for a long time now, is in need of reassessment. While there is little doubt that high levels of ROS are detrimental, mounting evidence points toward a lifespan extension effect exerted by mild to moderate ROS elevation. Dietary caloric restriction, inhibition of insulin-like growth factor-I signaling, and inhibition of the nutrient-sensing mechanistic target of rapamycin are robust longevity-promoting interventions. All of these appear to elicit mitochondrial retrograde signaling processes (defined as signaling from the mitochondria to the rest of the cell, for example, the mitochondrial unfolded protein response, or UPRmt). The effects of mitochondrial retrograde signaling may even spread to other cells/tissues in a noncell autonomous manner by yet unidentified signaling mediators. Multiple recent publications support the notion that an evolutionarily conserved, mitochondria-initiated signaling is central to the genetic and epigenetic regulation of cellular aging and organismal lifespan.

Are cachexia-associated tumors transmitTERS of ER stress?

2021 ◽  
Author(s):  
Ana Sayuri Yamagata ◽  
Paula Paccielli Freire
Keyword(s):  
Er Stress ◽  
Tumor Cells ◽  
Cancer Cachexia ◽  
Genotoxic Stress ◽  
Unfolded Protein ◽  
Response To Chemotherapy ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Associated Tumors

Cancer cachexia is associated with deficient response to chemotherapy. On the other hand, the tumors of cachectic patients remarkably express more chemokines and have higher immune infiltration. For immunogenicity, a strong induction of the unfolded protein response (UPR) is necessary. UPR followed by cell surface exposure of calreticulin on the dying tumor cell is essential for its engulfment by macrophages and dendritic cells. However, some tumor cells upon endoplasmic reticulum (ER) stress can release factors that induce ER stress to other cells, in the so-called transmissible ER stress (TERS). The cells that received TERS produce more interleukin 6 (IL-6) and chemokines and acquire resistance to subsequent ER stress, nutrient deprivation, and genotoxic stress. Since ER stress enhances the release of extracellular vesicles (EVs), we suggest they can mediate TERS. It was found that ER stressed cachexia-inducing tumor cells transmit factors that trigger ER stress in other cells. Therefore, considering the role of EVs in cancer cachexia, the release of exosomes can possibly play a role in the process of blunting the immunogenicity of the cachexia-associated tumors. We propose that TERS can cause an inflammatory and immunosuppressive phenotype in cachexia-inducing tumors.

scholarly journals Activating Transcription Factor 4 Is Translationally Regulated by Hypoxic Stress

2004 ◽  
Vol 24 (17) ◽  
pp. 7469-7482 ◽  
Author(s):  
Jaime D. Blais ◽  
Vasilisa Filipenko ◽  
Meixia Bi ◽  
Heather P. Harding ◽  
David Ron ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Microarray Analysis ◽  
Initiation Factor ◽  
Hypoxic Stress ◽  
Unfolded Protein ◽  
Activating Transcription Factor 4 ◽  
Activating Transcription Factor ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Transcription Factor 4

ABSTRACT Hypoxic stress results in a rapid and sustained inhibition of protein synthesis that is at least partially mediated by eukaryotic initiation factor 2α (eIF2α) phosphorylation by the endoplasmic reticulum (ER) kinase PERK. Here we show through microarray analysis of polysome-bound RNA in aerobic and hypoxic HeLa cells that a subset of transcripts are preferentially translated during hypoxia, including activating transcription factor 4 (ATF4), an important mediator of the unfolded protein response. Changes in mRNA translation during the unfolded protein response are mediated by PERK phosphorylation of the translation initiation factor eIF2α at Ser-51. Similarly, PERK is activated and is responsible for translational regulation under hypoxic conditions, while inducing the translation of ATF4. The overexpression of a C-terminal fragment of GADD34 that constitutively dephosphorylates eIF2α was able to attenuate the phosphorylation of eIF2α and severely inhibit the induction of ATF4 in response to hypoxic stress. These studies demonstrate the essential role of ATF4 in the response to hypoxic stress, define the pathway for its induction, and reveal that GADD34, a target of ATF4 activation, negatively regulates the eIF2α-mediated inhibition of translation. Taken with the concomitant induction of additional ER-resident proteins identified by our microarray analysis, this study suggests an important integrated response between ER signaling and the cellular adaptation to hypoxic stress.

scholarly journals Retrograde Control of Cytosolic Translation Targets Synthesis of Plastid Localized Proteins and Nuclear Responses for Efficient Light Acclimation

2021 ◽  
Author(s):  
Marten Moore ◽  
Aaron Smith ◽  
Corinna Wesemann ◽  
Sonja Schmidtpott ◽  
Melanie Wegener ◽  
...  
Keyword(s):  
Transcriptional Response ◽  
Transcript Abundance ◽  
Protein Translation ◽  
Retrograde Signaling ◽  
Just In Time ◽  
Protein Accumulation ◽  
Translation Efficiency ◽  
Multiple Components ◽  
Associated Proteins ◽  
Nuclear Responses

AbstractCanonical retrograde signaling is the transmission of information from organelles to the nucleus. Discrepancies between protein accumulation and transcript abundance in response to oxidative stress were suggestive of protein translation responding to retrograde signaling. Here we uncover multiple components of a translation-dependent retrograde signaling pathway that impact translation efficiency and gene expression, including the kinases, MPK6 and the SnRK1 subunit, AKIN10. Global ribosome foot-printing demonstrated rapid differential loading of 939 of transcripts from polyribosomes within 10 min after transfer from Low to High-light. Translationally regulated transcripts shared motifs in their 5’-UTR that act as binding sites for RBPs such as GAPC. The Stress Associated Proteins 2 and 3 carry such motifs in their UTRs and interact with the calcium sensor Calmodulin-like 49, relocating to the nucleus to co-regulate a translation-dependent transcriptional response. Translation dependent retrograde signaling bifurcates into a direct translational circuit and a translation-reliant nuclear circuit synchronizing translation, nuclear and anterograde response pathways, which may serve as a just in time-provision of needed proteins to the plastids.

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