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SenthilKumar G, Katunaric B, Zirgibel Z, Lindemer B, Jaramillo-Torres MJ, Bordas-Murphy H, Schulz ME, Pearson PJ, Freed JK. Necessary Role of Acute Ceramide Formation in The Human Microvascular Endothelium During Health and Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.02.543341. [PMID: 37333082 PMCID: PMC10274701 DOI: 10.1101/2023.06.02.543341] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Elevated plasma ceramides independently predict adverse cardiac events and we have previously shown that exposure to exogenous ceramide induces microvascular endothelial dysfunction in arterioles from otherwise healthy adults (0-1 risk factors for heart disease). However, evidence also suggests that activation of the shear-sensitive, ceramide forming enzyme neutral sphingomyelinase (NSmase) enhances vasoprotective nitric oxide (NO) production. Here we explore a novel hypothesis that acute ceramide formation through NSmase is necessary for maintaining NO signaling within the human microvascular endothelium. We further define the mechanism through which ceramide exerts beneficial effects and discern key mechanistic differences between arterioles from otherwise healthy adults and patients with coronary artery disease (CAD). Methods Human arterioles were dissected from otherwise discarded surgical adipose tissue (n=123), and vascular reactivity to flow and C2-ceramide was assessed. Shear-induced NO production was measured in arterioles using fluorescence microscopy. Hydrogen peroxide (H2O2) fluorescence was assessed in isolated human umbilical vein endothelial cells. Results Inhibition of NSmase in arterioles from otherwise healthy adults induced a switch from NO to H2O2-mediated flow-induced dilation within 30 minutes. In endothelial cells, NSmase inhibition acutely increased H2O2 production. Endothelial dysfunction in both models was prevented by treatment with C2-ceramide, S1P, and an agonist of S1P-receptor 1 (S1PR1), while the inhibition of S1P/S1PR1 signaling axis induced endothelial dysfunction. Ceramide increased NO production in arterioles from healthy adults, an effect that was diminished with inhibition of S1P/S1PR1/S1PR3 signaling. In arterioles from patients with CAD, inhibition of NSmase impaired dilation to flow. This effect was not restored with exogenous S1P. Although, inhibition of S1P/S1PR3 signaling impaired normal dilation to flow. Acute ceramide administration to arterioles from patients with CAD also promoted H2O2 as opposed to NO production, an effect dependent on S1PR3 signaling. Conclusion These data suggest that despite key differences in downstream signaling between health and disease, acute NSmase-mediated ceramide formation and its subsequent conversion to S1P is necessary for proper functioning of the human microvascular endothelium. As such, therapeutic strategies that aim to significantly lower ceramide formation may prove detrimental to the microvasculature.
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Affiliation(s)
- Gopika SenthilKumar
- Department of Physiology, Medical College of Wisconsin
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | | | - Zachary Zirgibel
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Brian Lindemer
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Maria J. Jaramillo-Torres
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Henry Bordas-Murphy
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Mary E. Schulz
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Paul J. Pearson
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin
| | - Julie K. Freed
- Department of Physiology, Medical College of Wisconsin
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
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Vásquez-Londoño CA, Howes MJR, Costa GM, Arboleda G, Rojas-Cardozo MA. Scutellaria incarnata Vent. root extract and isolated phenylethanoid glycosides are neuroprotective against C 2-ceramide toxicity. JOURNAL OF ETHNOPHARMACOLOGY 2023; 307:116218. [PMID: 36738946 DOI: 10.1016/j.jep.2023.116218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 01/13/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Neuronal death is a central process in neurodegenerative diseases and represents a therapeutic challenge for their prevention and treatment. Scutellaria incarnata Vent. roots are used traditionally in Colombia for central nervous system conditions including those affecting cognitive functions, but their chemistry and neuroprotective action remain to be explored to understand the scientific basis for their medicinal uses. In this study, S. incarnata roots are investigated to assess whether they have neuroprotective effects that could provide some explanation for their traditional use in neurodegenerative diseases. AIM OF THE STUDY To evaluate the neuroprotective effect of S. incarnata roots and its chemical constituents against C2-ceramide-induced cell death in Cath.-a-differentiated (CAD) cells. MATERIALS AND METHODS S. incarnata root ethanol extract was fractionated and compounds were isolated by column chromatography; their structures were elucidated by nuclear magnetic resonance spectroscopy, mass spectrometry and infrared spectroscopy. The cytotoxic and neuroprotective effects against C2-ceramide of S. incarnata root extract, fractions and isolated compounds were assessed in CAD cells. RESULTS S. incarnata root extract and its n-butanol fraction were not cytotoxic but showed neuroprotective effects against C2-ceramide toxicity in CAD cells. The phenylethanoid glycosides incarnatoside (isolated for the first time) and stachysoside C (12.5, 25 and 50 μg/mL) from S. incarnata roots also protected CAD cells against C2-ceramide without inducing cytotoxic effects. CONCLUSION The observed neuroprotective effects of S. incarnata root extract and isolated phenylethanoid glycosides in CAD cells provide an ethnopharmacological basis for the traditional use of this species in Colombia for central nervous system disorders.
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Affiliation(s)
- Carlos A Vásquez-Londoño
- Universidad Nacional de Colombia-Sede Bogotá, Faculty of Sciences, Department of Pharmacy, GIFFUN, Bogotá, 111321, Colombia.
| | | | - Geison M Costa
- Pontificia Universidad Javeriana, Faculty of Sciences, Department of Pharmacy, Bogotá, 110231, Colombia
| | - Gonzalo Arboleda
- Universidad Nacional de Colombia-Sede Bogotá, Faculty of Medicine, Department of Pathology - Genetic Institute, Bogotá, 111231, Colombia
| | - Maritza A Rojas-Cardozo
- Universidad Nacional de Colombia-Sede Bogotá, Faculty of Sciences, Department of Pharmacy, GIFFUN, Bogotá, 111321, Colombia.
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Fan C, Tian Y, Zhang Y, Teng J, Zhao X. Ceramide induces macrophage migration inhibitory factor -mediated parthanatos in mouse neurons by increasing ROS levels. Neurosci Lett 2022; 788:136862. [PMID: 36075319 DOI: 10.1016/j.neulet.2022.136862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 11/30/2022]
Abstract
Ceramides, the key component of sphingolipid metabolism and second messengers, have been associated with neurodegenerative diseases progression and pathology, and can induce neuronal apoptosis and necrosis, but the effect of ceramide on parthanatos has not been fully elucidated. In this study, we investigated the ceramide-mediated parthanatos pathway and the role of macrophage inhibitory factor (MIF) in parthanatos. We found that ceramide significantly diminished the viability and induced the death of primary cortical neurons. These effects were not prevented by treatment with the pan-caspase inhibitor Z-VAD-FMK treatment; in contrast, treatment with the poly (ADP ribosyl) polymerase-1 (PARP-1) inhibitor ABT-888 prevented these ceramide-mediated effects. Specifically, ceramide induced PARP-1 overactivation, increased PAR polymer levels, facilitated apoptosis-inducing factor (AIF) and MIF nuclear translocation and induced DNA damage. Knockdown of MIF with an adenovirus carrying a MIF short hairpin RNA (shRNA) inhibited ceramide-induced DNA damage and neuronal death, but nuclear translocation of AIF was unaffected. Furthermore, ceramide increased reactive oxygen species (ROS) levels, and N-acetyl cysteine (NAC) significantly inhibited PAR production and neuronal death. These findings suggested that ceramide induced neuronal parthanatos by increasing ROS levels and that MIF might be downstream of AIF in the ceramide-mediated parthanatos pathway. In conclusion, our results suggest that knocking down MIF expression may be a potential therapeutic strategy for nervous system diseases.
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Affiliation(s)
- Chenghe Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China; Henan Medical College of Zhengzhou University, No.50 Zhongyuan Road, Erqi District, Zhengzhou 450052, China
| | - Yu Tian
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China; Henan Medical College of Zhengzhou University, No.50 Zhongyuan Road, Erqi District, Zhengzhou 450052, China
| | - Yilin Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China; Henan Medical College of Zhengzhou University, No.50 Zhongyuan Road, Erqi District, Zhengzhou 450052, China
| | - Junfang Teng
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China; Henan Medical College of Zhengzhou University, No.50 Zhongyuan Road, Erqi District, Zhengzhou 450052, China; Department of Neurological Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China.
| | - Xinyu Zhao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China; Henan Medical College of Zhengzhou University, No.50 Zhongyuan Road, Erqi District, Zhengzhou 450052, China; Department of Neurological Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China.
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Fan C, Zhang Y, Tian Y, Zhao X, Teng J. Phloretin enhances autophagy by impairing AKT activation and inducing JNK-Beclin-1 pathway activation. Exp Mol Pathol 2022; 127:104814. [PMID: 35878674 DOI: 10.1016/j.yexmp.2022.104814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 05/16/2022] [Accepted: 07/16/2022] [Indexed: 12/01/2022]
Abstract
Phloretin is a type of dihydrochalcone that is primarily found in apples and has been reported to possess various potent biological activities, such as anticancer, antioxidant and anti-inflammatory effects. Our previous study has shown that phloretin induces apoptosis in human glioblastoma. In this study, we found that phloretin induced autophagy in SH-SY5Y cells by decreasing p-AKT and p-mTOR levels in the AKT/mTOR pathway and increasing the activation of JNK, the phosphorylation of c-Jun and the expression of Beclin-1. Moreover, the upregulation of Beclin-1 was decreased by SP600125 or a siRNA against c-Jun. Furthermore, SP600125 and siRNAs against c-Jun and Beclin-1 inhibited phloretin-induced autophagy. In addition, inhibition of phloretin-induced autophagy by cotreatment with phloretin and 3-MA decreased phloretin-induced cytotoxicity to SH-SY5Y cells. In conclusion, our results suggest that the AKT/mTOR pathway and JNK-mediated Beclin-1 expression are involved in phloretin-induced autophagy. Phloretin can be used to protect neurons during phloretin treatment of glioblastoma.
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Affiliation(s)
- Chenghe Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China
| | - Yilin Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China
| | - Yu Tian
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China
| | - Xinyu Zhao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China.
| | - Junfang Teng
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1 Jianshe East Road, Erqi District, Zhengzhou 450052, China.
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Zhang Z, Sun X, Wang K, Yu Y, Zhang L, Zhang K, Gu J, Yuan X, Song G. Hydrogen-saturated saline mediated neuroprotection through autophagy via PI3K/AKT/mTOR pathway in early and medium stages of rotenone-induced Parkinson's disease rats. Brain Res Bull 2021; 172:1-13. [PMID: 33838212 DOI: 10.1016/j.brainresbull.2021.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 03/20/2021] [Accepted: 04/02/2021] [Indexed: 02/07/2023]
Abstract
Some cardiovascular symptoms in the early stage of Parkinson's disease (PD) were related to degeneration of the rostral ventrolateral medulla (RVLM) catecholaminergic neurons. To date, little is known about the effects of hydrogen water on early stage of PD. Here, protective actions of hydrogen-saturated saline (HS) on rotenone-induced PD rats, as well as its underlying mechanisms were investigated. HS was used to treat PD rats at three general stages; early, medium and late, which were represented by rotenone induced rats for 0, 7 and 14 days. HS treatment significantly alleviated the cardiovascular and motor symptoms in rotenone-induced PD rats, improved the survival number of RVLM catecholaminergic neurons and nigral dopamine neurons only in early and medium stages of PD rats. Decreased levels of reactive oxygen species (ROS) and alpha-synuclein (α-Syn), transformation of microtubule associated protein 1 light chain 3 (LC3)-I/II and degradation of sequestosome 1 (p62) were detected, as well as increased expression level of autophagy related protein 5 (ATG5) and B-cell lymphoma-2 interacting protein 1 (Beclin-1) in the RVLM and substantia nigra (SN) after HS treatment in early and medium stages of PD rats. In addition, phosphorylation levels of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt) and mammalian rapamycin target protein (mTOR) decreased after HS treatment in early and medium stages of PD rats. The results suggested that HS treatment exerted beneficial effects in early and medium stages before motor impairments emerged but not in the late stage of rotenone-induced PD rats. It exerted neuroprotection with RVLM catecholaminergic neurons and nigral dopamine neurons, mediated in part by decreasing levels of ROS and α-Syn through increasing autophagy machinery which were partly via inhibiting PI3K-Akt-mTOR pathway.
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Affiliation(s)
- Zhaoqiang Zhang
- Department of Physiology, Basic Medical College of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, China
| | - Xiao Sun
- Department of Nephrology, Taian City Central Hospital, Taian, 271000, China
| | - Kun Wang
- Postdoctoral Workstation, Taian City Central Hospital, Taian, 271000, China
| | - Yang Yu
- Life Science Research Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, China
| | - Li Zhang
- Department of Electrocardiogram, Taian Traditional Chinese Medicine Hospital, Taian, 271000, China
| | - Keping Zhang
- Department of Physiology, Basic Medical College of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, China
| | - Jinglongfei Gu
- Department of Physiology, Basic Medical College of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, China
| | - Xiaofan Yuan
- Department of Physiology, Basic Medical College of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, China
| | - Guohua Song
- Life Science Research Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271000, China.
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Iessi E, Marconi M, Manganelli V, Sorice M, Malorni W, Garofalo T, Matarrese P. On the role of sphingolipids in cell survival and death. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 351:149-195. [PMID: 32247579 DOI: 10.1016/bs.ircmb.2020.02.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Sphingolipids, universal components of biological membranes of all eukaryotic organisms, from yeasts to mammals, in addition of playing a structural role, also play an important part of signal transduction pathways. They participate or, also, ignite several fundamental subcellular signaling processes but, more in general, they directly contribute to key biological activities such as cell motility, growth, senescence, differentiation as well as cell fate, i.e., survival or death. The sphingolipid metabolic pathway displays an intricate network of reactions that result in the formation of multiple sphingolipids, including ceramide, and sphingosine-1-phosphate. Different sphingolipids, that have key roles in determining cell fate, can induce opposite effects: as a general rule, sphingosine-1-phosphate promotes cell survival and differentiation, whereas ceramide is known to induce apoptosis. Furthermore, together with cholesterol, sphingolipids also represent the basic lipid component of lipid rafts, cholesterol- and sphingolipid-enriched membrane microdomains directly involved in cell death and survival processes. In this review, we briefly describe the characteristics of sphingolipids and lipid membrane microdomains. In particular, we will consider the involvement of various sphingolipids per se and of lipid rafts in apoptotic pathway, both intrinsic and extrinsic, in nonapoptotic cell death, in autophagy, and in cell differentiation. In addition, their roles in the most common physiological and pathological contexts either as pathogenetic elements or as biomarkers of diseases will be considered. We would also hint how the manipulation of sphingolipid metabolism could represent a potential therapeutic target to be investigated and functionally validated especially for those diseases for which therapeutic options are limited or ineffective.
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Affiliation(s)
- Elisabetta Iessi
- Center for Gender-Specific Medicine, Oncology Unit, Istituto Superiore di Sanità, Rome, Italy
| | - Matteo Marconi
- Center for Gender-Specific Medicine, Oncology Unit, Istituto Superiore di Sanità, Rome, Italy
| | | | - Maurizio Sorice
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Walter Malorni
- Center for Gender-Specific Medicine, Oncology Unit, Istituto Superiore di Sanità, Rome, Italy; Department of Biology, University of Rome Tor Vergata, Rome, Italy.
| | - Tina Garofalo
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Paola Matarrese
- Center for Gender-Specific Medicine, Oncology Unit, Istituto Superiore di Sanità, Rome, Italy
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Jin S, Gao J, Qi Y, Hao Y, Li X, Liu Q, Liu J, Liu D, Zhu L, Lin B. TGF-β1 fucosylation enhances the autophagy and mitophagy via PI3K/Akt and Ras-Raf-MEK-ERK in ovarian carcinoma. Biochem Biophys Res Commun 2020; 524:970-976. [PMID: 32059847 DOI: 10.1016/j.bbrc.2020.02.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 02/04/2020] [Indexed: 12/23/2022]
Abstract
Transforming growth factor-β, a cell secretion factor of the TGF-β superfamily, is involved in the regulation of cell proliferation, differentiation, cytoskeleton formation, migration, invasion and other biological behaviors. Autophagy and mitophagy play an important role in tumor progression by regulating self-digestion, and degradation and reuse of cells and mitochondria. In this study, changes in autophagy and mitophagy processes in ovarian cancer cells under TGF-β1 treatment were detected via Western blot and immunofluorescence, as well as the role of fucosylation modification. Changes in mitochondrial membrane potential in response to TGF-β1 and fucosylation were detected via immunofluorescence. The effects of TGF-β1 and its fucosylation on autophagic flux were further determined by transient transfection of cells with Ad-mRFP-GFP-LC3 adenovirus. TGF-β1 clearly promoted autophagy and mitophagy in ovarian cancer cells. TGF-β1 fucosylation stimulated these regulatory effects on ovarian cancer cells via modulation of PI3K/Akt and Ras-Raf-MEK-ERK pathways through TAK1. Our collective data support the physiological significance of TGF-β1 and provide a novel direction for targeted therapy for ovarian cancer.
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Affiliation(s)
- Shan Jin
- Shengjing Hospital of China Medical University, China
| | - Jian Gao
- Shengjing Hospital of China Medical University, China
| | - Yue Qi
- Shengjing Hospital of China Medical University, China
| | - Yingying Hao
- Shengjing Hospital of China Medical University, China
| | - Xiao Li
- Shengjing Hospital of China Medical University, China
| | - Qing Liu
- Shengjing Hospital of China Medical University, China
| | - Juanjuan Liu
- Shengjing Hospital of China Medical University, China
| | - Dawo Liu
- Shengjing Hospital of China Medical University, China
| | - Liancheng Zhu
- Shengjing Hospital of China Medical University, China
| | - Bei Lin
- Shengjing Hospital of China Medical University, China.
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Inhibition of protein phosphatase 1 stimulates noncanonical ER stress eIF2α activation to enhance fisetin-induced chemosensitivity in HDAC inhibitor-resistant hepatocellular carcinoma cells. Cancers (Basel) 2019; 11:cancers11070918. [PMID: 31261976 PMCID: PMC6678694 DOI: 10.3390/cancers11070918] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/14/2019] [Accepted: 06/28/2019] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a common fatal type of malignant tumor that has highly metastatic and recurrent properties. Fisetin is a natural flavonoid found in various vegetables and fruits which exhibits anti-cancer and anti-inflammatory properties, as well as other effects. Thus, we hypothesized that fisetin can act as an adjuvant therapy in cancer or drug-resistant cancer cells, and further investigated the molecular mechanisms underlying the development of drug-resistance in HCC cells. We found that fisetin effectively inhibited the cell viability of not only parental cells but also histone deacetylase inhibitors-resistant (HDACis-R) cells and enhanced the chemosensitivity of HCC cells. Interestingly, fisetin did not induce cell apoptosis through the activation of the endoplasmic reticulum (ER) stress sensor of protein kinase R (PKR)-like endoplasmic reticulum kinase, but rather through the non-canonical pathway of the protein phosphatase 1 (PP1)-mediated suppression of eIF2α phosphorylation. Moreover, fisetin-induced cell apoptosis was reversed by treatment with PP1 activator or eIF2α siRNA in HCC cells. Based on these observations, we suggest that PP1-eIF2α pathways are significantly involved in the effect of fisetin on HCC apoptosis. Thus, fisetin may act as a novel anticancer drug and new chemotherapy adjuvant which can improve the efficacy of chemotherapeutic agents and diminish their side-effects.
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van Echten-Deckert G, Alam S. Sphingolipid metabolism - an ambiguous regulator of autophagy in the brain. Biol Chem 2019; 399:837-850. [PMID: 29908127 DOI: 10.1515/hsz-2018-0237] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 05/25/2018] [Indexed: 01/12/2023]
Abstract
In mammals, the brain exhibits the highest lipid content in the body next to adipose tissue. Complex sphingolipids are characteristic compounds of neuronal membranes. Vital neural functions including information flux and transduction occur along these membranes. It is therefore not surprising that neuronal function and survival is dependent on the metabolism of these lipids. Autophagy is a critical factor for the survival of post-mitotic neurons. On the one hand, it fulfils homeostatic and waste-recycling functions and on the other hand, it constitutes an effective strategy to eliminate harmful proteins that cause neuronal death. A growing number of experimental data indicate that several sphingolipids as well as enzymes catalyzing their metabolic transformations efficiently but very differently affect neuronal autophagy and hence survival. This review attempts to elucidate the roles and mechanisms of sphingolipid metabolism with regard to the regulation of autophagy and its consequences for brain physiology and pathology.
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Affiliation(s)
- Gerhild van Echten-Deckert
- LIMES Institute, Unit Membrane Biology and Lipid Biochemistry, Kekulé-Institute of the University Bonn, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany
| | - Shah Alam
- LIMES Institute, Unit Membrane Biology and Lipid Biochemistry, Kekulé-Institute of the University Bonn, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany
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Prado Spalm FH, Vera MS, Dibo MJ, Simón MV, Politi LE, Rotstein NP. Ceramide Induces the Death of Retina Photoreceptors Through Activation of Parthanatos. Mol Neurobiol 2018; 56:4760-4777. [DOI: 10.1007/s12035-018-1402-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/17/2018] [Indexed: 01/02/2023]
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Abstract
Macroautophagy (herein referred to as autophagy) is a highly conserved stress response that engulfs damaged proteins, lipids, and/or organelles within double-membrane vesicles called autophagosomes for lysosomal degradation. Dysregulated autophagy is a hallmark of cancer; and thus, there is great interest in modulating autophagy for cancer therapy. Sphingolipids regulate each step of autophagosome biogenesis with roles for sphingolipid metabolites and enzymes spanning from the initial step of de novo ceramide synthesis to the sphingosine-1-phosphate lyase 1-mediated exit from the sphingolipid pathway. Notably, sphingolipid metabolism occurs at several of the organelles that contribute to autophagosome biogenesis to suggest that local changes in sphingolipids may regulate autophagy. As sphingolipid metabolism is frequently dysregulated in cancer, a molecular understanding of sphingolipids in stress-induced autophagy may provide insight into the mechanisms driving tumor development and progression. On the contrary, modulation of sphingolipid metabolites and/or enzymes can induce autophagy-dependent cell death for cancer therapy. This chapter will overview the major steps in mammalian autophagy, discuss the regulation of each step by sphingolipid metabolites, and describe the functions of sphingolipid-mediated autophagy in cancer. While our understanding of the signaling and biophysical properties of sphingolipids in autophagy remains in its infancy, the unique cross talk between the two pathways is an exciting area for further development, particularly in the context of cancer therapy.
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Affiliation(s)
- Megan M Young
- Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Hong-Gang Wang
- Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA, United States
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