1
|
Briançon-Marjollet A, Netchitaïlo M, Fabre F, Belaidi E, Arnaud C, Borel AL, Levy P, Pépin JL, Tamisier R. Intermittent hypoxia increases lipid insulin resistance in healthy humans: A randomized crossover trial. J Sleep Res 2024:e14243. [PMID: 38866393 DOI: 10.1111/jsr.14243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/25/2024] [Accepted: 05/05/2024] [Indexed: 06/14/2024]
Abstract
Sympathetic overactivity caused by chronic intermittent hypoxia is a hallmark of obstructive sleep apnea. A high sympathetic tone elicits increases in plasma free fatty acid and insulin. Our objective was to assess the impact of 14 nights of chronic intermittent hypoxia exposure on sympathetic activity, glucose control, lipid profile and subcutaneous fat tissue remodelling in non-obese healthy humans. In this prospective, double-blinded crossover study, 12 healthy subjects were randomized, among them only nine underwent the two phases of exposures of 14 nights chronic intermittent hypoxia versus air. Sympathetic activity was measured by peroneal microneurography (muscle sympathetic nerve activity) before and after each exposure. Fasting glucose, insulin, C-peptide and free fatty acid were assessed at rest and during a multisampling oral glucose tolerance test. We assessed histological remodelling, adrenergic receptors, lipolysis and lipogenesis genes expression and functional changes of the adipose tissue. Two weeks of exposure of chronic intermittent hypoxia versus ambient air significantly increased sympathetic activity (p = 0.04). Muscle sympathetic nerve activity increased from 24.5 [18.9; 26.8] before to 21.7 [13.8; 25.7] after ambient air exposure, and from 20.6 [17.4; 23.9] before to 28.0 [24.4; 31.5] bursts per min after exposure to chronic intermittent hypoxia. After chronic intermittent hypoxia, post-oral glucose tolerance test circulating free fatty acid area under the curve increased (p = 0.05) and free fatty acid sensitivity to insulin decreased (p = 0.028). In adipocyte tissue, intermittent hypoxia increased expression of lipolysis genes (adipocyte triglyceride lipase and hormone-sensitive lipase) and lipogenesis genes (fatty acid synthase; p < 0.05). In this unique experimental setting in healthy humans, chronic intermittent hypoxia induced high sympathetic tone, lipolysis and decreased free fatty acid sensitivity to insulin. This might participate in the trajectory to systemic insulin resistance and diabetes for patients with obstructive sleep apnea.
Collapse
Affiliation(s)
| | - Marie Netchitaïlo
- Univ. Grenoble Alpes, HP2; Inserm U1300, Grenoble, France
- Service de physiologie respiratoire et de l'exercice, CHU Rouen Normandie, Rouen, France
| | - Fanny Fabre
- Univ. Grenoble Alpes, HP2; Inserm U1300, Grenoble, France
- Service anesthésie, Centre Hospitalier de Mayotte (Pôle BACS), Mamoudzou, France
| | - Elise Belaidi
- Univ. Grenoble Alpes, HP2; Inserm U1300, Grenoble, France
- Laboratoire de Biologie Tissulaire et Ingénierie thérapeutique UMR5305, Lyon, France
| | - Claire Arnaud
- Univ. Grenoble Alpes, HP2; Inserm U1300, Grenoble, France
| | - Anne-Laure Borel
- Univ. Grenoble Alpes, HP2; Inserm U1300, Grenoble, France
- CHU Grenoble Alpes, Endocrinology, Diabetology, Nutrition, Grenoble, France
| | - Patrick Levy
- Univ. Grenoble Alpes, HP2; Inserm U1300, Grenoble, France
- CHU Grenoble Alpes, Clinique Universitaire de Pneumologie et Physiologie, Pole Thorax et Vaisseaux, Grenoble, France
| | - Jean-Louis Pépin
- Univ. Grenoble Alpes, HP2; Inserm U1300, Grenoble, France
- CHU Grenoble Alpes, Clinique Universitaire de Pneumologie et Physiologie, Pole Thorax et Vaisseaux, Grenoble, France
| | - Renaud Tamisier
- Univ. Grenoble Alpes, HP2; Inserm U1300, Grenoble, France
- CHU Grenoble Alpes, Clinique Universitaire de Pneumologie et Physiologie, Pole Thorax et Vaisseaux, Grenoble, France
| |
Collapse
|
2
|
Kudo T, Zhao ML, Jeknić S, Kovary KM, LaGory EL, Covert MW, Teruel MN. Context-dependent regulation of lipid accumulation in adipocytes by a HIF1α-PPARγ feedback network. Cell Syst 2023; 14:1074-1086.e7. [PMID: 37995680 PMCID: PMC11251692 DOI: 10.1016/j.cels.2023.10.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 12/03/2022] [Accepted: 10/26/2023] [Indexed: 11/25/2023]
Abstract
Hypoxia-induced upregulation of HIF1α triggers adipose tissue dysfunction and insulin resistance in obese patients. HIF1α closely interacts with PPARγ, the master regulator of adipocyte differentiation and lipid accumulation, but there are conflicting results regarding how this interaction controls the excessive lipid accumulation that drives adipocyte dysfunction. To directly address these conflicts, we established a differentiation system that recapitulated prior seemingly opposing observations made across different experimental settings. Using single-cell imaging and coarse-grained mathematical modeling, we show how HIF1α can both promote and repress lipid accumulation during adipogenesis. Our model predicted and our experiments confirmed that the opposing roles of HIF1α are isolated from each other by the positive-feedback-mediated upregulation of PPARγ that drives adipocyte differentiation. Finally, we identify three factors: strength of the differentiation cue, timing of hypoxic perturbation, and strength of HIF1α expression changes that, when considered together, provide an explanation for many of the previous conflicting reports.
Collapse
Affiliation(s)
- Takamasa Kudo
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - Michael L Zhao
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - Stevan Jeknić
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Kyle M Kovary
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - Edward L LaGory
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Markus W Covert
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
| | - Mary N Teruel
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Biochemistry and the Drukier Institute of Children's Health, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA.
| |
Collapse
|
3
|
Muscle Lipid Oxidation Is Not Affected by Obstructive Sleep Apnea in Diabetes and Healthy Subjects. Int J Mol Sci 2023; 24:ijms24065308. [PMID: 36982383 PMCID: PMC10048979 DOI: 10.3390/ijms24065308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/05/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
The molecular mechanisms linking obstructive sleep apnea (OSA) with type 2 diabetes mellitus (T2DM) remain unclear. This study investigated the effect of OSA on skeletal muscle lipid oxidation in nondiabetic controls and in type 2 diabetes (T2DM) patients. Forty-four participants matched for age and adiposity were enrolled: nondiabetic controls (control, n = 14), nondiabetic patients with severe OSA (OSA, n = 9), T2DM patients with no OSA (T2DM, n = 10), and T2DM patients with severe OSA (T2DM + OSA, n = 11). A skeletal muscle biopsy was performed; gene and protein expressions were determined and lipid oxidation was analyzed. An intravenous glucose tolerance test was performed to investigate glucose homeostasis. No differences in lipid oxidation (178.2 ± 57.1, 161.7 ± 22.4, 169.3 ± 50.9, and 140.0 ± 24.1 pmol/min/mg for control, OSA, T2DM, and T2DM+OSA, respectively; p > 0.05) or gene and protein expressions were observed between the groups. The disposition index, acute insulin response to glucose, insulin resistance, plasma insulin, glucose, and HBA1C progressively worsened in the following order: control, OSA, T2DM, and T2DM + OSA (p for trend <0.05). No association was observed between the muscle lipid oxidation and the glucose metabolism variables. We conclude that severe OSA is not associated with reduced muscle lipid oxidation and that metabolic derangements in OSA are not mediated through impaired muscle lipid oxidation.
Collapse
|
4
|
Timon R, Martinez-Guardado I, Brocherie F. Effects of Intermittent Normobaric Hypoxia on Health-Related Outcomes in Healthy Older Adults: A Systematic Review. SPORTS MEDICINE - OPEN 2023; 9:19. [PMID: 36843041 PMCID: PMC9968673 DOI: 10.1186/s40798-023-00560-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 02/05/2023] [Indexed: 02/27/2023]
Abstract
BACKGROUND Aging is a degenerative process that is associated with an increased risk of diseases. Intermittent hypoxia has been investigated in reference to performance and health-related functions enhancement. This systematic review aimed to summarize the effect of either passive or active intermittent normobaric hypoxic interventions compared with normoxia on health-related outcomes in healthy older adults. METHODS Relevant studies were searched from PubMed and Web of Science databases in accordance with PRISMA guidelines (since their inceptions up until August 9, 2022) using the following inclusion criteria: (1) randomized controlled trials, clinical trials and pilot studies; (2) Studies involving humans aged > 50 years old and without any chronic diseases diagnosed; (3) interventions based on in vivo intermittent systemic normobaric hypoxia exposure; (4) articles focusing on the analysis of health-related outcomes (body composition, metabolic, bone, cardiovascular, functional fitness or quality of life). Cochrane Collaboration recommendations were used to assess the risk of bias. RESULTS From 509 articles initially found, 17 studies were included. All interventions were performed in moderate normobaric hypoxia, with three studies using passive exposure, and the others combining intermittent hypoxia with training protocols (i.e., using resistance-, whole body vibration- or aerobic-based exercise). CONCLUSIONS Computed results indicate a limited effect of passive/active intermittent hypoxia (ranging 4-24 weeks, 2-4 days/week, 16-120 min/session, 13-16% of fraction of inspired oxygen or 75-85% of peripheral oxygen saturation) compared to similar intervention in normoxia on body composition, functional fitness, cardiovascular and bone health in healthy older (50-75 years old) adults. Only in specific settings (i.e., intermediate- or long-term interventions with high intensity/volume training sessions repeated at least 3 days per week), may intermittent hypoxia elicit beneficial effects. Further research is needed to determine the dose-response of passive/active intermittent hypoxia in the elderly. TRIAL REGISTRATION SYSTEMATIC REVIEW REGISTRATION PROSPERO 2022 CRD42022338648.
Collapse
Affiliation(s)
- Rafael Timon
- Sport Sciences Faculty, Universidad de Extremadura, Av/ Universidad s/n, 10004, Cáceres, Spain.
| | - Ismael Martinez-Guardado
- grid.464701.00000 0001 0674 2310BRABE Group. Faculty of Life and Nature Sciences, Universidad de Nebrija, Madrid, Spain
| | - Franck Brocherie
- grid.418501.90000 0001 2163 2398Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport (INSEP), Paris, France
| |
Collapse
|
5
|
Meszaros M, Bikov A. Obstructive Sleep Apnoea and Lipid Metabolism: The Summary of Evidence and Future Perspectives in the Pathophysiology of OSA-Associated Dyslipidaemia. Biomedicines 2022; 10:2754. [PMID: 36359273 PMCID: PMC9687681 DOI: 10.3390/biomedicines10112754] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 10/27/2022] [Accepted: 10/27/2022] [Indexed: 09/29/2023] Open
Abstract
Obstructive sleep apnoea (OSA) is associated with cardiovascular and metabolic comorbidities, including hypertension, dyslipidaemia, insulin resistance and atherosclerosis. Strong evidence suggests that OSA is associated with an altered lipid profile including elevated levels of triglyceride-rich lipoproteins and decreased levels of high-density lipoprotein (HDL). Intermittent hypoxia; sleep fragmentation; and consequential surges in the sympathetic activity, enhanced oxidative stress and systemic inflammation are the postulated mechanisms leading to metabolic alterations in OSA. Although the exact mechanisms of OSA-associated dyslipidaemia have not been fully elucidated, three main points have been found to be impaired: activated lipolysis in the adipose tissue, decreased lipid clearance from the circulation and accelerated de novo lipid synthesis. This is further complicated by the oxidisation of atherogenic lipoproteins, adipose tissue dysfunction, hormonal changes, and the reduced function of HDL particles in OSA. In this comprehensive review, we summarise and critically evaluate the current evidence about the possible mechanisms involved in OSA-associated dyslipidaemia.
Collapse
Affiliation(s)
- Martina Meszaros
- Department of Pulmonology and Sleep Disorders Centre, University Hospital Zurich, 8091 Zurich, Switzerland
- Department of Pulmonology, Semmelweis University, 1083 Budapest, Hungary
| | - Andras Bikov
- North West Lung Centre, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester M23 9LT, UK
- Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester M13 9MT, UK
| |
Collapse
|
6
|
Intermittent Hypoxia as a Therapeutic Tool to Improve Health Parameters in Older Adults. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095339. [PMID: 35564732 PMCID: PMC9103404 DOI: 10.3390/ijerph19095339] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/21/2022] [Accepted: 04/26/2022] [Indexed: 12/23/2022]
Abstract
Aging is associated with metabolic alterations, and with a loss of strength, muscle and bone mass. Moderate intermittent hypoxia has been proposed as a new tool to enhance health-related function. The aim of this study was to evaluate the effect of moderate intermittent hypoxia exposures on parameters related to cardiovascular and bone health in older adults. A total of 38 healthy older adults (aged 65-75 years) were divided into two groups: control group (C), and hypoxia group (H) that was subjected to an intermittent hypoxia exposure (at simulated altitude of 2500 m asl) during a 24-week period (3 days/week). Body composition, blood pressure, metabolic parameters (Cholesterol, triglycerides and glucose), C-reactive protein (CRP), vascular cell adhesion molecule-1 (VCAM-1), interleukin 8 (IL-8), interleukin 10 (IL-10), N-terminal propeptide of type I procollagen (PINP) and beta C-terminal telopeptide of collagen bone formation (b-CTX) were analyzed before and after the intervention. A repeated measures analysis of variance was performed to evaluate between-group differences. The results showed that the hypoxia group achieved after the intervention a decrease in fat mass, CRP (pro-inflammatory biomarker) and b-CTX (bone resorption biomarker), as well as an increase in PINP (bone formation biomarker). In conclusion, the intermittent hypoxia might be a useful therapeutic tool to deal with problems associated with aging, such as the increase in body fat, the loss of bone mass or low-grade inflammation.
Collapse
|
7
|
Yang XD, Ge XC, Jiang SY, Yang YY. Potential lipolytic regulators derived from natural products as effective approaches to treat obesity. Front Endocrinol (Lausanne) 2022; 13:1000739. [PMID: 36176469 PMCID: PMC9513423 DOI: 10.3389/fendo.2022.1000739] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
Epidemic obesity is contributing to increases in the prevalence of obesity-related metabolic diseases and has, therefore, become an important public health problem. Adipose tissue is a vital energy storage organ that regulates whole-body energy metabolism. Triglyceride degradation in adipocytes is called lipolysis. It is closely tied to obesity and the metabolic disorders associated with it. Various natural products such as flavonoids, alkaloids, and terpenoids regulate lipolysis and can promote weight loss or improve obesity-related metabolic conditions. It is important to identify the specific secondary metabolites that are most effective at reducing weight and the health risks associated with obesity and lipolysis regulation. The aims of this review were to identify, categorize, and clarify the modes of action of a wide diversity of plant secondary metabolites that have demonstrated prophylactic and therapeutic efficacy against obesity by regulating lipolysis. The present review explores the regulatory mechanisms of lipolysis and summarizes the effects and modes of action of various natural products on this process. We propose that the discovery and development of natural product-based lipolysis regulators could diminish the risks associated with obesity and certain metabolic conditions.
Collapse
Affiliation(s)
- Xi-Ding Yang
- Department of Pharmacy, Second Xiangya Hospital of Central South University, Changsha, China
- Phase I Clinical Trial Center, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Xing-Cheng Ge
- Xiangxing College, Hunan University of Chinese Medicine, Changsha, China
| | - Si-Yi Jiang
- Department of Pharmacy, Medical College, Yueyang Vocational Technical College, YueYang, China
| | - Yong-Yu Yang
- Department of Pharmacy, Second Xiangya Hospital of Central South University, Changsha, China
- Hunan Provincial Engineering Research Central of Translational Medical and Innovative Drug, The Second Xiangya Hospital of Central South University, Changsha, China
- *Correspondence: Yong-Yu Yang,
| |
Collapse
|
8
|
Butyric acid alleviated chronic intermittent hypoxia-induced lipid formation and inflammation through up-regulating HuR expression and inactivating AMPK pathways. Biosci Rep 2021; 41:228420. [PMID: 33876818 PMCID: PMC8220371 DOI: 10.1042/bsr20203639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 04/09/2021] [Accepted: 04/15/2021] [Indexed: 11/24/2022] Open
Abstract
To investigate whether butyric acid could alleviate chronic intermittent hypoxia (CIH)-induced lipid formation in human preadipocytes-subcutaneous (HPA-s) through accumulation of human antigen R (HuR) and inactivation of AMP-activated protein kinase (AMPK) pathway, HPA-s were obtained and divided into three groups: Control group: cells were cultured under normal conditions; CIH group: cells were cultured in a three-gas incubator (10% O2); Butyric acid group: 10 mmol/l butyric acid added into cell culture medium. HuR-siRNA was futher transfected into CIH group for verification the function of HuR. Oil Red O was implemented for observation of lipid droplets within cells. Cell Counting Kit-8 (CCK8) assay was used for detecting cell viability. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labeling (TUNEL) assay as well as flow cytometry analysis was employed for determining cell apoptosis. Western blotting was used for measurement of protein expression levels. RT-qPCR analysis was used for detecting mRNA expression. CIH treatment increased adipocytes proliferation, while butyric acid inhibited cell proliferation and promoted cell apoptosis. The treatment of butyric acid in CIH group down-regulated expression of inflammatory factors and increased cell apoptotic rate. Butyric acid treatment increased HuR expression in both cytoplasm and nucleus and decreased the level of p-AMPK and p-ACC, while transfection of AMPK activator or HuR-siRNA would down-regulate HuR expression. Moreover, butyric acid alleviated CIH-induced cell proliferation, lipid formation and inflammatory status and promoted cell apoptosis through regulating related genes including p21, PPARγ, C/EBPa, IL-1β, IL-6, TLR4, caspase-8 and caspase-3. In conclusion, butyric acid could alleviate CIH-induced inflammation, cell proliferation and lipid formation through accumulation of HuR and inactivation of AMPK pathway.
Collapse
|
9
|
Obstructive sleep apnoea increases lipolysis and deteriorates glucose homeostasis in patients with type 2 diabetes mellitus. Sci Rep 2021; 11:3567. [PMID: 33574418 PMCID: PMC7878919 DOI: 10.1038/s41598-021-83018-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 01/25/2021] [Indexed: 12/26/2022] Open
Abstract
Obstructive sleep apnoea (OSA) is associated with type 2 diabetes mellitus (T2DM). However, mechanisms mediating association between these two conditions remain unclear. This study investigated, whether the OSA-associated changes in adipose tissue lipolysis might contribute to impaired glucose homeostasis in patient with T2DM. Thirty-five matched subjects were recruited into three groups: T2DM + severe OSA (T2DM + OSA, n = 11), T2DM with mild/no OSA (T2DM, n = 10) and healthy controls (n = 14). Subcutaneous abdominal adipose tissue microdialysis assessed spontaneous, epinephrine- and isoprenaline-stimulated lipolysis. Glucose metabolism was assessed by intravenous glucose tolerance test. Spontaneous lipolysis was higher in the T2DM + OSA compared with the T2DM (60.34 ± 23.40 vs. 42.53 ± 10.16 μmol/L, p = 0.013), as well as epinephrine-stimulated lipolysis (236.84 ± 103.90 vs. 167.39 ± 52.17 µmol/L, p < 0.001). Isoprenaline-stimulated lipolysis was unaffected by the presence of OSA (p = 0.750). The α2 anti-lipolytic effect was decreased in T2DM + OSA by 59% and 315% compared with T2DM and controls (p = 0.045 and p = 0.007, respectively). The severity of OSA (AHI) was positively associated with spontaneous (p = 0.037) and epinephrine-stimulated (p = 0.026) lipolysis. The α2-adrenergic anti-lipolytic effect (p = 0.043) decreased with increasing AHI. Spontaneous lipolysis was positively associated with Insulin resistance (r = 0.50, p = 0.002). Epinephrine-stimulated lipolysis was negatively associated with the Disposition index (r = - 0.34, p = 0.048). AHI was positively associated with Insulin resistance (p = 0.017) and negatively with the Disposition index (p = 0.038). Severe OSA in patients with T2DM increased adipose tissue lipolysis, probably due to inhibition of the α2-adrenergic anti-lipolytic effect. We suggest that dysregulated lipolysis might contribute to OSA-associated impairments in insulin secretion and sensitivity.
Collapse
|
10
|
Ascenção K, Dilek N, Augsburger F, Panagaki T, Zuhra K, Szabo C. Pharmacological induction of mesenchymal-epithelial transition via inhibition of H2S biosynthesis and consequent suppression of ACLY activity in colon cancer cells. Pharmacol Res 2021; 165:105393. [PMID: 33484818 DOI: 10.1016/j.phrs.2020.105393] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/12/2020] [Accepted: 12/12/2020] [Indexed: 02/07/2023]
Abstract
Hydrogen sulfide (H2S) is an important endogenous gaseous transmitter mediator, which regulates a variety of cellular functions in autocrine and paracrine manner. The enzymes responsible for the biological generation of H2S include cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST). Increased expression of these enzymes and overproduction of H2S has been implicated in essential processes of various cancer cells, including the stimulation of metabolism, maintenance of cell proliferation and cytoprotection. Cancer cell identity is characterized by so-called "transition states". The progression from normal (epithelial) to transformed (mesenchymal) state is termed epithelial-to-mesenchymal transition (EMT) whereby epithelial cells lose their cell-to-cell adhesion capacity and gain mesenchymal characteristics. The transition process can also proceed in the opposite direction, and this process is termed mesenchymal-to-epithelial transition (MET). The current project was designed to determine whether inhibition of endogenous H2S production in colon cancer cells affects the EMT/MET balance in vitro. Inhibition of H2S biosynthesis in HCT116 human colon cancer cells was achieved either with aminooxyacetic acid (AOAA) or 2-[(4-hydroxy-6-methylpyrimidin-2-yl)sulfanyl]-1-(naphthalen-1-yl)ethan-1-one (HMPSNE). These inhibitors induced an upregulation of E-cadherin and Zonula occludens-1 (ZO-1) expression and downregulation of fibronectin expression, demonstrating that H2S biosynthesis inhibitors can produce a pharmacological induction of MET in colon cancer cells. These actions were functionally reflected in an inhibition of cell migration, as demonstrated in an in vitro "scratch wound" assay. The mechanisms involved in the action of endogenously produced H2S in cancer cells in promoting (or maintaining) EMT (or tonically inhibiting MET) relate, at least in part, in the induction of ATP citrate lyase (ACLY) protein expression, which occurs via upregulation of ACLY mRNA (via activation of the ACLY promoter). ACLY in turn, regulates the Wnt-β-catenin pathway, an essential regulator of the EMT/MET balance. Taken together, pharmacological inhibition of endogenous H2S biosynthesis in cancer cells induces MET. We hypothesize that this may contribute to anti-cancer / anti-metastatic effects of H2S biosynthesis inhibitors.
Collapse
Affiliation(s)
- Kelly Ascenção
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| | - Nahzli Dilek
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| | - Fiona Augsburger
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| | - Theodora Panagaki
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| | - Karim Zuhra
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| | - Csaba Szabo
- Chair of Pharmacology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| |
Collapse
|