bims-cemest 2024-12-08 papers

bims-cemest

Biomed News

on Cell metabolism and stress

Issue of 2024–12–08
nine papers selected by
Jessica Rosarda, Uniformed Services University

Taurine Protects Irinotecan-induced Muscle Dysfunction by Modulating Oxidative Stress and Endoplasmic Reticulum Stress in Human Skeletal Muscle Cells.
Temporal control of acute protein aggregate turnover by UBE3C and NRF1-dependent proteasomal pathways.
Protective Effects of NRF2 Activator Sulforaphane in Polyinosinic:Polycytidylic Acid-Induced In Vitro and In Vivo Model.
Photodynamic therapy photosensitizers and photoactivated chemotherapeutics exhibit distinct bioenergetic profiles to impact ATP metabolism.
Skeletal muscle-derived musclin attenuates glycolysis, oxidative stress, and pulmonary hypertension through the NPR3/AKT/mTORC1 pathway.
Mito-TEMPO Ameliorates Sodium Palmitate Induced Ferroptosis in MIN6 Cells through PINK1/Parkin-Mediated Mitophagy.
Mammalian mitochondrial inorganic polyphosphate (polyP) and cell signaling: Crosstalk between PolyP and the activity of AMPK.
Nicotinamide riboside targets mitochondrial unfolded protein response to reduce alcohol-induced damage in Kupffer cells.
Amino Acid and Glucose Fermentation Maintain ATP Content in Mouse and Human Malignant Glioma Cells.

Anticancer Res. 2024 Dec;44(12): 5371-5378

Taurine Protects Irinotecan-induced Muscle Dysfunction by Modulating Oxidative Stress and Endoplasmic Reticulum Stress in Human Skeletal Muscle Cells.

Chih-I Chen, Yu-Chi Chen, Yi-Kai Kao, Chia-Hung Chen, Po-Wen Yang, Pin-Chun Chen, Ling-Chiao Song, Kai Lung Tsai.

   BACKGROUND/AIM: Irinotecan is a key component of standard first-line treatment for metastatic colorectal cancer. However, irinotecan-induced muscle dysfunction is a contributing factor to cancer cachexia. Here, we present the protective effect of taurine, a conditionally essential amino acid with great antioxidant properties, in attenuating muscle dysfunction induced by irinotecan.
MATERIALS AND METHODS: Irinotecan (20 μg/ml) was added to human skeletal muscle cells (HSkMCs) with or without pre-treatment of taurine (5 mM). The effects of taurine and irinotecan on the viability, cytotoxicity, and differentiation ability of HSkMC myoblasts were examined. The intracellular reactive oxygen species (ROS) and endoplasmic reticulum stress (ERS) were also monitored.
RESULTS: Irinotecan caused cytotoxicity of HSkMCs, while taurine pretreatment increased cell viability and inhibited adenylate kinase release significantly in both myoblasts and myotubes. During differentiation, taurine increased ROS clearance and preserved the myotube differentiation ability impaired by irinotecan. Irinotecan exposure resulted in the up-regulation of CCAAT/enhancer-binding protein homologous protein (CHOP) and glucose-regulated protein 78 (GRP78). Taurine pretreatment could combat such irinotecan-induced ERS.
CONCLUSION: The current in vitro study provides molecular evidence that taurine plays a beneficial role in protecting against irinotecan-induced muscle dysfunction by modulating oxidative stress and endoplasmic reticulum stress.

Keywords:  Taurine; cancer cachexia; endoplasmic reticulum stress; irinotecan; oxidative stress

DOI:  https://doi.org/10.21873/anticanres.17364
Proc Natl Acad Sci U S A. 2024 Dec 10. 121(50): e2417390121

Temporal control of acute protein aggregate turnover by UBE3C and NRF1-dependent proteasomal pathways.

Kelsey L Hickey, Alexandra Panov, Enya Miguel Whelan, Tillman Schäfer, Arda Mizrak, Ron R Kopito, Wolfgang Baumeister, Rubén Fernández-Busnadiego, J Wade Harper.

  A hallmark of neurodegenerative diseases (NDs) is the progressive loss of proteostasis, leading to the accumulation of misfolded proteins or protein aggregates, with subsequent cytotoxicity. To combat this toxicity, cells have evolved degradation pathways (ubiquitin-proteasome system and autophagy) that detect and degrade misfolded proteins. However, studying the underlying cellular pathways and mechanisms has remained a challenge, as formation of many types of protein aggregates is asynchronous, with individual cells displaying distinct kinetics, thereby hindering rigorous time-course studies. Here, we merge a kinetically tractable and synchronous agDD-GFP system for aggregate formation with targeted gene knockdowns, to uncover degradation mechanisms used in response to acute aggregate formation. We find that agDD-GFP forms amorphous aggregates by cryo-electron tomography at both early and late stages of aggregate formation. Aggregate turnover occurs in a proteasome-dependent mechanism in a manner that is dictated by cellular aggregate burden, with no evidence of the involvement of autophagy. Lower levels of misfolded agDD-GFP, enriched in oligomers, utilizes UBE3C-dependent proteasomal degradation in a pathway that is independent of RPN13 ubiquitylation by UBE3C. Higher aggregate burden activates the NRF1 transcription factor to increase proteasome subunit transcription and subsequent degradation capacity of cells. Loss or gain of NRF1 function alters the turnover of agDD-GFP under conditions of high aggregate burden. Together, these results define the role of UBE3C in degradation of this class of misfolded aggregation-prone proteins and reveals a role for NRF1 in proteostasis control in response to widespread protein aggregation.

Keywords:  protein aggregates; protein quality control; protein turnover; ubiquitin-proteasome system

DOI:  https://doi.org/10.1073/pnas.2417390121
J Biochem Mol Toxicol. 2024 Dec;38(12): e70086

Protective Effects of NRF2 Activator Sulforaphane in Polyinosinic:Polycytidylic Acid-Induced In Vitro and In Vivo Model.

Shailesh Vilas Matsagar, Rakesh Kumar Singh.

  NRF2 is a nuclear transcription factor involved in the cellular protection against oxidative stress and inflammatory signaling. Sulforaphane is a known NRF2 activator used for its strong antioxidant and anti-inflammatory activity through regulation of Keap-1-HO-1 pathway. However, there is a limited exploration about the role of NRF2 activator, sulforaphane in regulation of poly(I:C)-induced oxidative stress, inflammation and injury in lung. Therefore, we aimed to evaluate the therapeutic effect of sulforaphane in poly(I:C)-induced responses using in vitro as well as in vivo model. We evaluated oxidative stress and inflammatory cytokines in poly(I:C)-induced RAW264.7 cells. We also employed in vivo animal study to evaluate tissue oxidative-antioxidative balance along with expression of NRF2, Keap-1, histopathological assessment by hematoxylin-eosin staining and picrosirius red staining to explore the protective mechanisms of sulforaphane in poly(I:C)-induced mouse model. Our results indicated that sulforaphane increased the expression of NRF2 and its downstream proteins. In addition, sulforaphane alleviated poly(I:C)-induced activation of the oxidative and pro-inflammatory pathways, histopathological changes, depleted expression of GSH and superoxide dismutase in lung tissue. This study suggested that sulforaphane may be one of the useful therapeutic alternatives for poly(I:C) induced lung injury and inflammation.

Keywords:  NRF2; histology; lung inflammation; oxidative stress; poly(I:C); sulforaphane

DOI:  https://doi.org/10.1002/jbt.70086
Chem Sci. 2024 Nov 21.

Photodynamic therapy photosensitizers and photoactivated chemotherapeutics exhibit distinct bioenergetic profiles to impact ATP metabolism.

Richard J Mitchell, Dmytro Havrylyuk, Austin C Hachey, David K Heidary, Edith C Glazer.

Energy is essential for all life, and mammalian cells generate and store energy in the form of ATP by mitochondrial (oxidative phosphorylation) and non-mitochondrial (glycolysis) metabolism. These processes can now be evaluated by extracellular flux analysis (EFA), which has proven to be an indispensable tool in cell biology, providing previously inaccessible information regarding the bioenergetic landscape of cell lines, complex tissues, and in vivo models. Recently, EFA demonstrated its utility as a screening tool in drug development, both by providing insights into small molecule-organelle interactions, and by revealing the peripheral and potentially undesired off-target effects small molecules have within cells. Surprisingly, technologies to quantify cellular bioenergetics have not been systematically applied in phototherapy development, leaving open several questions about how the mechanism of action of a compound can impact essential cellular functions. Here, we utilized the Seahorse analyzer to address this question for photosensitizers (PSs) for photodynamic therapy (PDT) and contrast these systems to molecules that photo-release a ligand and thus act as photocages or photoactivated chemotherapeutics (PACT), intending to understand the influence these two classes of compounds have on cellular bioenergetics. EFA results show that acute treatment of A549 lung adenocarcinoma cells with PDT agents induces a quiescent bioenergetic response as a result of mitochondrial respiration shutdown. The loss of oxidative phosphorylation is followed by disruption of glycolysis, which occurs after an initial increase in glycolytic respiration is unable to compensate for the interruption of the electron transport chain (ETC). In contrast, the PACT agents tested had little impact on cellular respiration, and the minor inhibition of these metabolic processes was not related to the mechanism of action, as reflected by a lack of correlation with photoejection efficiency. Notably, a system capable of both generating 1O2 and photo-releasing a ligand exhibited the dominant profile of a PDT agent and induced the quiescent bioenergetic state, indicating potential implications on cellular bioenergetics for so-called dual-action agents. These findings are presented with the aim to provide the necessary groundwork for expanding the application and utility of EFA to phototherapeutics and to highlight the role of metabolic alterations in PDT.

DOI: https://doi.org/10.1039/d4sc05393a
Acta Biochim Biophys Sin (Shanghai). 2024 Dec 05.

Skeletal muscle-derived musclin attenuates glycolysis, oxidative stress, and pulmonary hypertension through the NPR3/AKT/mTORC1 pathway.

Xiongshan Sun, Jia Wang, Yi Xiao, De Li, Qiang Wang, Wei Guo, Yongjian Yang.

  Exercise ameliorates pulmonary hypertension (PH) progression. However, the underlying mechanisms are largely unclear. Musclin is an exercise-responsive myokine that exerts protective effects on cardiovascular diseases. The current study aims to explore the role of musclin in the development of PH. A monocrotaline (MCT)-induced mouse PH model is established. Adeno-associated virus serotype 6 (AAV6)-mediated gene transfer is used to induce musclin overexpression in skeletal muscle. Ultrasound and morphological analyses are utilized to assess the severity of PH. Cell viability assay, Ki-67 immunofluorescence staining, wound healing assay, and transwell assay are used to evaluate the proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs). We find that the musclin levels in both plasma and skeletal muscle are decreased in MCT-treated mice. The external expression of musclin in skeletal muscle ameliorates pulmonary arterial remodeling and right ventricular dysfunction. In vitro, musclin treatment suppresses hypoxia-induced glycolysis, oxidative stress, proliferation, and migration. Further experiments reveal that musclin inhibits mechanistic target of rapamycin complex 1 (mTORC1) activity in hypoxia-stimulated PASMCs and pulmonary arteries of MCT-treated mice. Reactivating mTORC1 abolishes the protective role of musclin against PH. Additionally, musclin enhances its interaction with natriuretic peptide receptor 3 (NPR3) in PASMCs. Silencing of NPR3 reverses the inhibitory effects of musclin on AKT phosphorylation, mTORC1 activity, glycolysis, oxidative stress, proliferation, and migration in hypoxia-challenged PASMCs. In conclusion, our study highlights the inhibitory role of musclin in the proliferation and migration of PASMCs and PH progression, thereby providing a novel potent therapeutic strategy for treating PH and partly clarifying the mechanism of exercise-mediated protection against PH.

Keywords:  NPR3; PASMC; PH; glycolysis; mTORC1; musclin; oxidative stress

DOI:  https://doi.org/10.3724/abbs.2024214
Biomed Environ Sci. 2024 Oct 20. 37(10): 1128-1141

Mito-TEMPO Ameliorates Sodium Palmitate Induced Ferroptosis in MIN6 Cells through PINK1/Parkin-Mediated Mitophagy.

Baolei Chang, Yanyu Su, Tingting Li, Yanxia Zheng, Ruirui Yang, Heng Lu, Hao Wang, Yusong Ding.

   Objective: Mitochondrial reactive oxygen species (mtROS) could cause damage to pancreatic β-cells, rendering them susceptible to oxidative damage. Hence, investigating the potential of the mitochondria-targeted antioxidant (Mito-TEMPO) to protect pancreatic β-cells from ferroptosis by mitigating lipid peroxidation becomes crucial.
Methods: MIN6 cells were cultured in vitro with 100 μmol/L sodium palmitate (SP) to simulate diabetes. FerroOrange was utilized for the detection of Fe 2+ fluorescence staining, BODIPY581/591C11 for lipid reactive oxygen species, and MitoSox-Red for mtROS. Alterations in mitophagy levels were assessed through the co-localization of lysosomal and mitochondrial fluorescence. Western blotting was employed to quantify protein levels of Acsl4, GPX4, FSP1, FE, PINK1, Parkin, TOMM20, P62, and LC3. Subsequently, interventions were implemented using Mito-TEMPO and Carbonyl cyanide 3-chlorophenylhydrazone (CCCP) to observe changes in ferroptosis and mitophagy within MIN6 cells.
Results: We found that SP induced a dose-dependent increase in Fe 2+ and lipid ROS in MIN6 cells while decreasing the expression levels of GPX4 and FSP1 proteins. Through bioinformatics analysis, it has been uncovered that mitophagy assumes a crucial role within the ferroptosis pathway associated with diabetes. Additionally, SP decreased the expression of mitophagy-related proteins PINK1 and Parkin, leading to mtROS overproduction. Conversely, Mito-TEMPO effectively eliminated mtROS while activating the mitophagy pathways involving PINK1 and Parkin, thereby reducing the occurrence of ferroptosis in MIN6 cells. CCCP also demonstrated efficacy in reducing ferroptosis in MIN6 cells.
Conclusion: In summary, Mito-TEMPO proved effective in attenuating mtROS production and initiating mitophagy pathways mediated by PINK1 and Parkin in MIN6 cells. Consequently, this decreased iron overload and lipid peroxidation, ultimately safeguarding the cells from ferroptosis.

Keywords:  Bioinformatical analysis; Ferroptosis; MIN6; Mitophagy; MtROS; Type 2 diabetes

DOI:  https://doi.org/10.3967/bes2024.111
Mol Metab. 2024 Nov 30. pii: S2212-8778(24)00208-4. [Epub ahead of print] 102077

Mammalian mitochondrial inorganic polyphosphate (polyP) and cell signaling: Crosstalk between PolyP and the activity of AMPK.

Renata T Da Costa, Anna Nichenko, Matheus M Perez, Malgorzata Tokarska-Schlattner, Sheida Kavehmoghaddam, Vedangi Hambardikar, Ernest R Scoma, Erin L Seifert, Uwe Schlattner, Joshua C Drake, Maria E Solesio.

  Inorganic polyphosphate (polyP) is an evolutionary ancient polymer composed by orthophosphate units linked by phosphoanhydride bonds. In mammalian cells, polyP shows a high localization in mammalian mitochondria, and its regulatory role in various aspects of bioenergetics has already been demonstrated, via molecular mechanism(s) yet to be fully elucidated. In recent years, a role for polyP in signal transduction, from brain physiology to bloodstream, has also emerged. The intriguing possibility is that the effects of polyP on signal transduction could be mechanistically linked to those exerted on bioenergetics. Here, using a combination of cellular and animal models, we demonstrate for the first time the intimate crosstalk between the levels of polyP and the activation status of the AMPK signaling pathway, via a mechanism involving free phosphate homeostasis. AMPK is a key player in mammalian cell signaling, and a crucial regulator of cellular and mitochondrial homeostasis. Our results show that the depletion of mitochondrial polyP in mammalian cells downregulates the activity of AMPK. Moreover, increased levels of polyP activate AMPK. Accordingly, the genetic downregulation of AMPKα1 impairs polyP levels in both SH-SY5Y cells and in the brains of female mice. Our findings shed new light on the regulation of AMPK and position polyP as a potent regulator of mammalian cell physiology beyond mere bioenergetics, paving the road for using its metabolism as an innovative pharmacological target in pathologies characterized by dysregulated bioenergetics.

Keywords:  AMPK; Bioenergetics; Cell signaling; Inorganic polyphosphate; Mammalian cells; Mitochondria

DOI:  https://doi.org/10.1016/j.molmet.2024.102077
J Pathol. 2024 Dec 03.

Nicotinamide riboside targets mitochondrial unfolded protein response to reduce alcohol-induced damage in Kupffer cells.

Jaeeun Lee, Hayoung Woo, Hyunju Kang, Young-Ki Park, Ji-Young Lee.

  The pathogenesis of alcohol-related liver disease (ALD) is closely linked to mitochondrial dysfunction and impaired cellular energy metabolism. In this study, we explored how ethanol triggers inflammation, oxidative stress, and mitochondrial dysfunction in Kupffer cells, i.e.hepatic resident macrophages, primarily focusing on the mitochondrial unfolded protein response (UPRmt) using immortalized mouse Kupffer cells (ImKCs) and mouse primary KCs. The UPRmt is a cellular defense mechanism activated in response to the perturbation of mitochondrial proteostasis to maintain mitochondrial integrity and function by upregulating the expression of mitochondrial chaperones and proteases. We also determined whether nicotinamide riboside (NR), a NAD+ precursor, could mitigate ethanol-triggered cellular damage. When ImKCs were exposed to 80 mm ethanol for 72 h, they displayed inflammation, oxidative stress, and impaired mitochondrial function with decreased mitochondrial content and deformed mitochondrial crista structure. NR, however, counteracted the effects of ethanol. Furthermore, ethanol increased mRNA and protein levels of UPRmt genes, such as mitochondrial chaperones and proteases, which were attenuated by NR. Notably, the ethanol-induced shift in the entry of activating transcription factor 5 (ATF5), a putative transcriptional regulator of UPRmt, to the nucleus from the mitochondria was abolished by NR. The induction of UPRmt genes by ethanol was significantly repressed when Atf5 was knocked down, indicating the role of ATF5 in the induction of UPRmt genes in ImKCs exposed to ethanol. We also confirmed the induction of UPRmt gene expression in mouse and human livers exposed to alcohol. Our findings demonstrate the ability of NR to alleviate ethanol-induced oxidative stress, inflammation, and mitochondrial dysfunction, partly by modulating the ATF5-dependent UPRmt pathway in ImKCs, suggesting its potential for ALD therapy. © 2024 The Pathological Society of Great Britain and Ireland.

Keywords:  Kupffer cells; ethanol metabolism; mitochondrial unfolded protein response; nicotinamide riboside

DOI:  https://doi.org/10.1002/path.6372
ASN Neuro. 2024 ;16(1): 2422268

Amino Acid and Glucose Fermentation Maintain ATP Content in Mouse and Human Malignant Glioma Cells.

Derek C Lee, Linh Ta, Purna Mukherjee, Tomas Duraj, Marek Domin, Bennett Greenwood, Srada Karmacharya, Niven R Narain, Michael Kiebish, Christos Chinopoulos, Thomas N Seyfried.

  Energy is necessary for tumor cell viability and growth. Aerobic glucose-driven lactic acid fermentation is a common metabolic phenotype seen in most cancers including malignant gliomas. This metabolic phenotype is linked to abnormalities in mitochondrial structure and function. A luciferin-luciferase bioluminescence ATP assay was used to measure the influence of amino acids, glucose, and oxygen on ATP content and viability in mouse (VM-M3 and CT-2A) and human (U-87MG) glioma cells that differed in cell biology, genetic background, and species origin. Oxygen consumption was measured using the Resipher system. Extracellular lactate and succinate were measured as end products of the glycolysis and glutaminolysis pathways, respectively. The results showed that: (1) glutamine was a source of ATP content irrespective of oxygen. No other amino acid could replace glutamine in sustaining ATP content and viability; (2) ATP content persisted in the absence of glucose and under hypoxia, ruling out substantial contribution through either glycolysis or oxidative phosphorylation (OxPhos) under these conditions; (3) Mitochondrial complex IV inhibition showed that oxygen consumption was not an accurate measure for ATP production through OxPhos. The glutaminase inhibitor, 6-diazo-5-oxo-L-norleucine (DON), reduced ATP content and succinate export in cells grown in glutamine. The data suggests that mitochondrial substrate level phosphorylation in the glutamine-driven glutaminolysis pathway contributes to ATP content in these glioma cells. A new model is presented highlighting the synergistic interaction between the high-throughput glycolysis and glutaminolysis pathways that drive malignant glioma growth and maintain ATP content through the aerobic fermentation of both glucose and glutamine.

Keywords:  Fermentation; glioblastoma; glutaminolysis; mitochondrial substrate level phosphorylation; succinate

DOI:  https://doi.org/10.1080/17590914.2024.2422268