1
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Hon KW, Naidu R. Synergistic Mechanisms of Selected Polyphenols in Overcoming Chemoresistance and Enhancing Chemosensitivity in Colorectal Cancer. Antioxidants (Basel) 2024; 13:815. [PMID: 39061884 PMCID: PMC11273411 DOI: 10.3390/antiox13070815] [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: 06/03/2024] [Revised: 06/29/2024] [Accepted: 07/03/2024] [Indexed: 07/28/2024] Open
Abstract
Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. Despite significant advances in medical treatment, chemotherapy as monotherapy can lead to substantial side effects and chemoresistance. This underscores the need for therapeutic approaches that are not only pharmacologically safe but also modulate multiple potent signaling pathways and sensitize cancer cells to overcome resistance to standard drugs. In recent years, scientists have been searching for natural compounds that can be used as chemosensitizers in addition to conventional medications for the synergistic treatment of CRC. Polyphenols represent a diverse group of natural compounds that can target multiple signaling pathways in cancer cells to induce anti-cancer effects. Additionally, polyphenols have been shown to work synergistically with chemotherapeutics and other natural compounds in cancer cells. This review aims to provide a comprehensive insight into the synergistic mechanisms of selected polyphenols as chemosensitizers in CRC cells. Further research and clinical trials are warranted to fully harness the synergistic mechanisms of selected polyphenols combined with chemotherapy or natural compounds in improving cancer treatment outcomes.
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Affiliation(s)
| | - Rakesh Naidu
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor Darul Ehsan, Malaysia;
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2
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Pochini L, Galluccio M, Console L, Scalise M, Eberini I, Indiveri C. Inflammation and Organic Cation Transporters Novel (OCTNs). Biomolecules 2024; 14:392. [PMID: 38672410 PMCID: PMC11048549 DOI: 10.3390/biom14040392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024] Open
Abstract
Inflammation is a physiological condition characterized by a complex interplay between different cells handled by metabolites and specific inflammatory-related molecules. In some pathological situations, inflammation persists underlying and worsening the pathological state. Over the years, two membrane transporters namely OCTN1 (SLC22A4) and OCTN2 (SLC22A5) have been shown to play specific roles in inflammation. These transporters form the OCTN subfamily within the larger SLC22 family. The link between these proteins and inflammation has been proposed based on their link to some chronic inflammatory diseases such as asthma, Crohn's disease (CD), and rheumatoid arthritis (RA). Moreover, the two transporters show the ability to mediate the transport of several compounds including carnitine, carnitine derivatives, acetylcholine, ergothioneine, and gut microbiota by-products, which have been specifically associated with inflammation for their anti- or proinflammatory action. Therefore, the absorption and distribution of these molecules rely on the presence of OCTN1 and OCTN2, whose expression is modulated by inflammatory cytokines and transcription factors typically activated by inflammation. In the present review, we wish to provide a state of the art on OCTN1 and OCTN2 transport function and regulation in relationships with inflammation and inflammatory diseases focusing on the metabolic signature collected in different body districts and gene polymorphisms related to inflammatory diseases.
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Affiliation(s)
- Lorena Pochini
- Laboratory of Biochemistry, Molecular Biotechnology and Molecular Biology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (M.G.); (L.C.); (M.S.)
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council (CNR), Via Amendola 122/O, 70126 Bari, Italy
| | - Michele Galluccio
- Laboratory of Biochemistry, Molecular Biotechnology and Molecular Biology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (M.G.); (L.C.); (M.S.)
| | - Lara Console
- Laboratory of Biochemistry, Molecular Biotechnology and Molecular Biology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (M.G.); (L.C.); (M.S.)
| | - Mariafrancesca Scalise
- Laboratory of Biochemistry, Molecular Biotechnology and Molecular Biology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (M.G.); (L.C.); (M.S.)
| | - Ivano Eberini
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milan, Italy;
| | - Cesare Indiveri
- Laboratory of Biochemistry, Molecular Biotechnology and Molecular Biology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (M.G.); (L.C.); (M.S.)
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council (CNR), Via Amendola 122/O, 70126 Bari, Italy
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3
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Walker MA, Chen H, Yadav A, Ritterhoff J, Villet O, McMillen T, Wang Y, Purcell H, Djukovic D, Raftery D, Isoherranen N, Tian R. Raising NAD + Level Stimulates Short-Chain Dehydrogenase/Reductase Proteins to Alleviate Heart Failure Independent of Mitochondrial Protein Deacetylation. Circulation 2023; 148:2038-2057. [PMID: 37965787 PMCID: PMC10842390 DOI: 10.1161/circulationaha.123.066039] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/04/2023] [Indexed: 11/16/2023]
Abstract
BACKGROUND Strategies to increase cellular NAD+ (oxidized nicotinamide adenine dinucleotide) level have prevented cardiac dysfunction in multiple models of heart failure, but molecular mechanisms remain unclear. Little is known about the benefits of NAD+-based therapies in failing hearts after the symptoms of heart failure have appeared. Most pretreatment regimens suggested mechanisms involving activation of sirtuin, especially Sirt3 (sirtuin 3), and mitochondrial protein acetylation. METHODS We induced cardiac dysfunction by pressure overload in SIRT3-deficient (knockout) mice and compared their response with nicotinamide riboside chloride treatment with wild-type mice. To model a therapeutic approach, we initiated the treatment in mice with established cardiac dysfunction. RESULTS We found nicotinamide riboside chloride improved mitochondrial function and blunted heart failure progression. Similar benefits were observed in wild-type and knockout mice. Boosting NAD+ level improved the function of NAD(H) redox-sensitive SDR (short-chain dehydrogenase/reductase) family proteins. Upregulation of Mrpp2 (mitochondrial ribonuclease P protein 2), a multifunctional SDR protein and a subunit of mitochondrial ribonuclease P, improves mitochondrial DNA transcripts processing and electron transport chain function. Activation of SDRs in the retinol metabolism pathway stimulates RXRα (retinoid X receptor α)/PPARα (proliferator-activated receptor α) signaling and restores mitochondrial oxidative metabolism. Downregulation of Mrpp2 and impaired mitochondrial ribonuclease P were found in human failing hearts, suggesting a shared mechanism of defective mitochondrial biogenesis in mouse and human heart failure. CONCLUSIONS These findings identify SDR proteins as important regulators of mitochondrial function and molecular targets of NAD+-based therapy. Furthermore, the benefit is observed regardless of Sirt3-mediated mitochondrial protein deacetylation, a widely held mechanism for NAD+-based therapy for heart failure. The data also show that NAD+-based therapy can be useful in pre-existing heart failure.
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Affiliation(s)
- Matthew A. Walker
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
| | - Hongye Chen
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
| | - Aprajita Yadav
- Department of Pharmaceutics, School of Pharmacy, University
of Washington, Seattle, WA 98195
| | - Julia Ritterhoff
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
| | - Outi Villet
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
| | - Tim McMillen
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
| | - Yuliang Wang
- Department of Computer Science & Engineering,
University of Washington, Seattle, WA 98195
| | - Hayley Purcell
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
| | - Danijel Djukovic
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
| | - Daniel Raftery
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
| | - Nina Isoherranen
- Department of Pharmaceutics, School of Pharmacy, University
of Washington, Seattle, WA 98195
| | - Rong Tian
- Mitochondria and Metabolism Center, Department of
Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
98109
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4
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Papierniak-Wyglądała A, Lamch W, Jurewicz E, Nałęcz KA. The activity and surface presence of organic cation/carnitine transporter OCTN2 (SLC22A5) in breast cancer cells depends on AKT kinase. Arch Biochem Biophys 2023; 742:109616. [PMID: 37187422 DOI: 10.1016/j.abb.2023.109616] [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: 02/16/2023] [Revised: 04/06/2023] [Accepted: 04/26/2023] [Indexed: 05/17/2023]
Abstract
l-carnitine is indispensable for transfer of fatty acids to mitochondria for the process of β-oxidation, a process, whose significance in cancer has drawn attention in recent years. In humans majority of carnitine is delivered by diet and enters the cell due to activity of solute carriers (SLCs), mainly by ubiquitously expressed organic cation/carnitine transporter (OCTN2/SLC22A5). In control and cancer human breast epithelial cell lines the major fraction of OCTN2 is present as a not matured non-glycosylated form. Studies on overexpressed OCTN2 demonstrated an exclusive interaction with SEC24C, as the cargo-recognizing subunit of coatomer II in transporter exit from endoplasmic reticulum. Co-transfection with SEC24C dominant negative mutant completely abolished presence of the mature form of OCTN2, pointing to a possibility of trafficking regulation. SEC24C was previously shown to be phosphorylated by serine/threonine kinase AKT, known to be activated in cancer. Further studies on breast cell lines showed that inhibition of AKT with MK-2206 in control and cancer lines decreased level of OCTN2 mature form. Proximity ligation assay showed that phosphorylation of OCTN2 on threonine was significantly abolished by AKT inhibition with MK-2206. Carnitine transport was positively correlated with the level of OCTN2 phosphorylated by AKT on threonine moiety. The observed regulation of OCTN2 by AKT places this kinase in the center of metabolic control. This points to both proteins, AKT and OCTN2, as druggable targets, in particular in a combination therapy of breast cancer.
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Affiliation(s)
- Anna Papierniak-Wyglądała
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland.
| | - Weronika Lamch
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland.
| | - Ewelina Jurewicz
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland.
| | - Katarzyna A Nałęcz
- Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland.
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5
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Pike B, Zhao J, Hicks JA, Wang F, Hagen R, Liu HC, Odle J, Lin X. Intestinal Carnitine Status and Fatty Acid Oxidation in Response to Clofibrate and Medium-Chain Triglyceride Supplementation in Newborn Pigs. Int J Mol Sci 2023; 24:ijms24076066. [PMID: 37047049 PMCID: PMC10094207 DOI: 10.3390/ijms24076066] [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: 02/28/2023] [Revised: 03/13/2023] [Accepted: 03/15/2023] [Indexed: 04/14/2023] Open
Abstract
To investigate the role of peroxisome proliferator-activated receptor alpha (PPARα) in carnitine status and intestinal fatty acid oxidation in neonates, a total of 72 suckled newborn piglets were assigned into 8 dietary treatments following a 2 (±0.35% clofibrate) × 4 (diets with: succinate+glycerol (Succ), tri-valerate (TC5), tri-hexanoate (TC6), or tri-2-methylpentanoate (TMPA)) factorial design. All pigs received experimental milk diets with isocaloric energy for 5 days. Carnitine statuses were evaluated, and fatty acid oxidation was measured in vitro using [1-14C]-palmitic acid (1 mM) as a substrate in absence or presence of L659699 (1.6 µM), iodoacetamide (50 µM), and carnitine (1 mM). Clofibrate increased concentrations of free (41%) and/or acyl-carnitine (44% and 15%) in liver and plasma but had no effects in the intestine. The effects on carnitine status were associated with the expression of genes involved in carnitine biosynthesis, absorption, and transportation. TC5 and TMPA stimulated the increased fatty acid oxidation rate induced by clofibrate, while TC6 had no effect on the increased fatty acid oxidation induced by clofibrate (p > 0.05). These results suggest that dietary clofibrate improved carnitine status and increased fatty acid oxidation. Propionyl-CoA, generated from TC5 and TMPA, could stimulate the increased fatty acid oxidation rate induced by clofibrate as anaplerotic carbon sources.
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Affiliation(s)
- Brandon Pike
- Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Jinan Zhao
- Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Julie A Hicks
- Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Feng Wang
- Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Rachel Hagen
- Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Hsiao-Ching Liu
- Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Jack Odle
- Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Xi Lin
- Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA
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6
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PGC-1α and MEF2 Regulate the Transcription of the Carnitine Transporter OCTN2 Gene in C2C12 Cells and in Mouse Skeletal Muscle. Int J Mol Sci 2022; 23:ijms232012304. [PMID: 36293168 PMCID: PMC9604316 DOI: 10.3390/ijms232012304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 11/05/2022] Open
Abstract
OCTN2 (SLC22A5) is a carnitine transporter whose main function is the active transport of carnitine into cells. In skeletal muscle and other organs, the regulation of the SLC22A5 gene transcription has been shown to depend on the nuclear transcription factor PPAR-α. Due to the observation that the muscle OCTN2 mRNA level is maintained in PPAR-α knock-out mice and that PGC-1α overexpression in C2C12 myoblasts increases OCTN2 mRNA expression, we suspected additional regulatory pathways for SLC22A5 gene transcription. Indeed, we detected several binding sites of the myocyte-enhancing factor MEF2 in the upstream region of the SLC22A5 gene, and MEF2C/MEF2D stimulated the activity of the OCTN2 promoter in gene reporter assays. This stimulation was increased by PGC-1α and was blunted for a SLC22A5 promoter fragment with a mutated MEF2 binding site. Further, we demonstrated the specific binding of MEF2 to the SLC22A5 gene promoter, and a supershift of the MEF2/DNA complex in electrophoretic mobility shift assays. In immunoprecipitation experiments, we could demonstrate the interaction between PGC-1α and MEF2. In addition, SB203580, a specific inhibitor of p38 MAPK, blocked and interferon-γ stimulated the transcriptional activity of the SLC22A5 gene promoter. Finally, mice with muscle-specific overexpression of OCTN2 showed an increase in OCTN2 mRNA and protein expression in skeletal muscle. In conclusion, we detected and characterized a second stimulatory pathway of SLC22A5 gene transcription in skeletal muscle, which involves the nuclear transcription factor MEF2 and co-stimulation by PGC-1α and which is controlled by the p38 MAPK signaling cascade.
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7
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Zhou S, Shu Y. Transcriptional Regulation of Solute Carrier (SLC) Drug Transporters. Drug Metab Dispos 2022; 50:DMD-MR-2021-000704. [PMID: 35644529 PMCID: PMC9488976 DOI: 10.1124/dmd.121.000704] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 05/02/2022] [Accepted: 05/16/2022] [Indexed: 09/03/2023] Open
Abstract
Facilitated transport is necessitated for large size, charged, and/or hydrophilic drugs to move across the membrane. The drug transporters in the solute carrier (SLC) superfamily, mainly including organic anion-transporting polypeptides (OATPs), organic anion transporters (OATs), organic cation transporters (OCTs), organic cation/carnitine transporters (OCTNs), peptide transporters (PEPTs), and multidrug and toxin extrusion proteins (MATEs), are critical facilitators of drug transport and distribution in human body. The expression of these SLC drug transporters is found in tissues throughout the body, with high abundance in the epithelial cells of major organs for drug disposition, such as intestine, liver, and kidney. These SLC drug transporters are clinically important in drug absorption, metabolism, distribution, and excretion. The mechanisms underlying their regulation have been revealing in recent years. Epigenetic and nuclear receptor-mediated transcriptional regulation of SLC drug transporters have particularly attracted much attention. This review focuses on the transcriptional regulation of major SLC drug transporter genes. Revealing the mechanisms underlying the transcription of those critical drug transporters will help us understand pharmacokinetics and pharmacodynamics, ultimately improving drug therapeutic effectiveness while minimizing drug toxicity. Significance Statement It has become increasingly recognized that solute carrier (SLC) drug transporters play a crucial, and sometimes determinative, role in drug disposition and response, which is reflected in decision-making during not only clinical drug therapy but also drug development. Understanding the mechanisms accounting for the transcription of these transporters is critical to interpret their abundance in various tissues under different conditions, which is necessary to clarify the pharmacological response, adverse effects, and drug-drug interactions for clinically used drugs.
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Affiliation(s)
- Shiwei Zhou
- Pharmaceutical Sciences, University of Maryland, United States
| | - Yan Shu
- Pharmaceutical Sciences, University of Maryland, United States
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8
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Erythrocyte transglutaminase-2 combats hypoxia and chronic kidney disease by promoting oxygen delivery and carnitine homeostasis. Cell Metab 2022; 34:299-316.e6. [PMID: 35108516 PMCID: PMC9380699 DOI: 10.1016/j.cmet.2021.12.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 09/29/2021] [Accepted: 12/21/2021] [Indexed: 02/03/2023]
Abstract
Due to lack of nuclei and de novo protein synthesis, post-translational modification (PTM) is imperative for erythrocytes to regulate oxygen (O2) delivery and combat tissue hypoxia. Here, we report that erythrocyte transglutminase-2 (eTG2)-mediated PTM is essential to trigger O2 delivery by promoting bisphosphoglycerate mutase proteostasis and the Rapoport-Luebering glycolytic shunt for adaptation to hypoxia, in healthy humans ascending to high altitude and in two distinct murine models of hypoxia. In a pathological hypoxia model with chronic kidney disease (CKD), eTG2 is critical to combat renal hypoxia-induced reduction of Slc22a5 transcription and OCNT2 protein levels via HIF-1α-PPARα signaling to maintain carnitine homeostasis. Carnitine supplementation is an effective and safe therapeutic approach to counteract hypertension and progression of CKD by enhancing erythrocyte O2 delivery. Altogether, we reveal eTG2 as an erythrocyte protein stabilizer orchestrating O2 delivery and tissue adaptive metabolic reprogramming and identify carnitine-based therapy to mitigate hypoxia and CKD progression.
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9
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Iliceto M, Stensen M, Andersen J, Haugen T, Witczak O. Levels of L-carnitine in human seminal plasma are associated with sperm fatty acid composition. Asian J Androl 2022; 24:451-457. [PMID: 35017387 PMCID: PMC9491039 DOI: 10.4103/aja2021107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The fatty acid composition of spermatozoa has been shown to be important for their function, and L-carnitine is crucial for fatty acid metabolism. Its levels in the seminal plasma positively correlate with semen quality, whereas high body mass index (BMI) is associated with both reduced semen quality and altered sperm fatty acid composition. Here, we examined the associations between free seminal L-carnitine levels and sperm fatty acid composition as well as BMI. Semen samples were collected and analyzed from 128 men with unknown fertility status and with BMI ranging from 19 kg m−2 to 63 kg m−2. Sperm fatty acid composition was assessed by gas chromatography, while free seminal L-carnitine analysis was performed using high-performance liquid chromatography. Multiple linear regression analysis showed a positive correlation of free seminal L-carnitine levels with the amount of sperm palmitic acid (β = 0.21; P = 0.014), docosahexaenoic acid (DHA; β = 0.23; P = 0.007), and total n-3 polyunsaturated fatty acids (β = 0.23; P = 0.008) and a negative correlation of free seminal L-carnitine levels with lignoceric acid (β = −0.29; P = 0.001) and total n-6 polyunsaturated fatty acids (β = −0.24; P = 0.012) when adjusted for covariates. There was no relationship between free seminal L-carnitine levels and BMI. Since free seminal L-carnitine levels are associated with semen quality, the absence of a correlation with BMI suggests that reduced semen quality in obese men is independent of seminal L-carnitine.
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10
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Comprehensive assessment of the effectiveness of l-carnitine and transresveratrol in rats with diet-induced obesity. Nutrition 2021; 95:111561. [PMID: 34999386 DOI: 10.1016/j.nut.2021.111561] [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: 04/07/2021] [Revised: 11/05/2021] [Accepted: 11/28/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVES Transresveratrol (Res) and l-carnitine (l-Car) are proposed to alleviate metabolic and immune disorders and increase physical activity in obese individuals. This study aims to estimate the effect of Res and l-Car in rats with diet-induced obesity. METHODS Male Wistar rats were fed a diet with excess fat and fructose (high-fat high-carbohydrate diet [HFCD]) supplemented with Res and l-Car at doses of 25 and 300 mg/kg of body weight, respectively, for 63 d. An assessment of grip strength, behavioral reactions, as well as biochemical, morphological, and immunological parameters, was performed. RESULTS Res supplementation did not affect energy consumption, but l-Car increased when animals had free access to feed. Body weight gains were the highest in animals fed the HFCD, lowest in rats receiving the control balanced diet, and intermediate in animals receiving Res and l-Car. Feeding with Res and l-Car canceled the decrease in long-term memory in rats fed the HFCD, as well as reduced anxiety and increased mobility. With both supplements, bilirubin, triglycerides, and low-density lipoprotein levels in the blood plasma returned to normal values, but only l-Car increased the ratio of aspartic and alanine transaminases. In addition, l-Car lowered the levels of leptin and ghrelin and increased transforming growth factor beta 1 in the blood plasma, and consumption of Res was accompanied by a decrease in interleukin-17A and increase in interferon gamma in spleen lysates. Moreover, l-Car reduced the number of cells with lipid inclusions in the liver. CONCLUSIONS The consumption of Res and l-Car leads to a significant reduction in dyslipidemia and inflammation with potentially favorable changes in behavioral responses.
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11
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Kawase A, Chuma T, Irie K, Kazaoka A, Kakuno A, Matsuda N, Shimada H, Iwaki M. Increased penetration of diphenhydramine in brain via proton-coupled organic cation antiporter in rats with lipopolysaccharide-induced inflammation. Brain Behav Immun Health 2020; 10:100188. [PMID: 34589723 PMCID: PMC8474606 DOI: 10.1016/j.bbih.2020.100188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/30/2020] [Accepted: 12/03/2020] [Indexed: 01/18/2023] Open
Abstract
Uptake transporters in brain microvascular endothelial cells (BMECs) are involved in the penetration of basic (cationic) drugs such as diphenhydramine (DPHM) into the brain. Lipopolysaccharide (LPS)-induced inflammation alters the expression levels and activities of uptake transporters, which change the penetration of DPHM into the brain. A brain microdialysis study showed that the unbound brain-to-plasma partition coefficient (Kp,uu,brain) for DPHM in LPS rats was approximately two times higher than that in control rats. The transcellular transport of DPHM to BMECs was increased when BMECs were cultured with serum from LPS rats. Compared with control rats or BMECs, the brain uptake of DPHM in LPS rats was increased and the intracellular accumulation of DPHM was increased under a high intracellular pH in BMECs from LPS rats, respectively. Treatment of BMECs with transporter inhibitors or inflammatory cytokines had little impact on the intracellular accumulation of DPHM in BMECs. This study suggests that LPS-induced inflammation promotes unidentified proton-coupled organic cation (H+/OC) antiporters that improve the penetration of DPHM into rat brain via the blood-brain barrier. The unbound brain-to-plasma partition coefficient for diphenhydramine (DPHM) was increased in lipopolysaccharide-induced inflammation in rats. The uptake of DPHM to brain microvascular endothelial cells (BMECs) was promoted by treatments of serum from rats with inflammation. Treatment of BMECs with transporter inhibitors or inflammatory cytokines had little impact on the intracellular accumulation of DPHM in BMECs. LPS-induced inflammation promotes unidentified proton-coupled organic cation antiporters that improve the brain penetration of DPHM.
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Affiliation(s)
- Atsushi Kawase
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Osaka, Japan
- Corresponding author. 3-4-1 Kowakae, Higashi-Osaka, Osaka, 577-8502, Japan.
| | - Taihei Chuma
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Osaka, Japan
| | - Kota Irie
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Osaka, Japan
| | - Akira Kazaoka
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Osaka, Japan
| | - Asuka Kakuno
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Osaka, Japan
| | - Naoya Matsuda
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Osaka, Japan
| | - Hiroaki Shimada
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Osaka, Japan
| | - Masahiro Iwaki
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Osaka, Japan
- Pharmaceutical Research and Technology Institute, Kindai University, Osaka, Japan
- Antiaging Center, Kindai University, Osaka, Japan
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12
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Juraszek B, Nałęcz KA. SLC22A5 (OCTN2) Carnitine Transporter-Indispensable for Cell Metabolism, a Jekyll and Hyde of Human Cancer. Molecules 2019; 25:molecules25010014. [PMID: 31861504 PMCID: PMC6982704 DOI: 10.3390/molecules25010014] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/12/2019] [Accepted: 12/14/2019] [Indexed: 12/26/2022] Open
Abstract
Oxidation of fatty acids uses l-carnitine to transport acyl moieties to mitochondria in a so-called carnitine shuttle. The process of β-oxidation also takes place in cancer cells. The majority of carnitine comes from the diet and is transported to the cell by ubiquitously expressed organic cation transporter novel family member 2 (OCTN2)/solute carrier family 22 member 5 (SLC22A5). The expression of SLC22A5 is regulated by transcription factors peroxisome proliferator-activated receptors (PPARs) and estrogen receptor. Transporter delivery to the cell surface, as well as transport activity are controlled by OCTN2 interaction with other proteins, such as PDZ-domain containing proteins, protein phosphatase PP2A, caveolin-1, protein kinase C. SLC22A5 expression is altered in many types of cancer, giving an advantage to some of them by supplying carnitine for β-oxidation, thus providing an alternative to glucose source of energy for growth and proliferation. On the other hand, SLC22A5 can also transport several chemotherapeutics used in clinics, leading to cancer cell death.
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Hausner EA, Elmore SA, Yang X. Overview of the Components of Cardiac Metabolism. Drug Metab Dispos 2019; 47:673-688. [PMID: 30967471 PMCID: PMC7333657 DOI: 10.1124/dmd.119.086611] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/26/2019] [Indexed: 12/20/2022] Open
Abstract
Metabolism in organs other than the liver and kidneys may play a significant role in how a specific organ responds to chemicals. The heart has metabolic capability for energy production and homeostasis. This homeostatic machinery can also process xenobiotics. Cardiac metabolism includes the expression of numerous organic anion transporters, organic cation transporters, organic carnitine (zwitterion) transporters, and ATP-binding cassette transporters. Expression and distribution of the transporters within the heart may vary, depending on the patient’s age, disease, endocrine status, and various other factors. Several cytochrome P450 (P450) enzyme classes have been identified within the heart. The P450 hydroxylases and epoxygenases within the heart produce hydroxyeicosatetraneoic acids and epoxyeicosatrienoic acids, metabolites of arachidonic acid, which are critical in regulating homeostatic processes of the heart. The susceptibility of the cardiac P450 system to induction and inhibition from exogenous materials is an area of expanding knowledge, as are the metabolic processes of glucuronidation and sulfation in the heart. The susceptibility of various transcription factors and signaling pathways of the heart to disruption by xenobiotics is not fully characterized but is an area with implications for disruption of normal postnatal development, as well as modulation of adult cardiac health. There are knowledge gaps in the timelines of physiologic maturation and deterioration of cardiac metabolism. Cross-species characterization of cardiac-specific metabolism is needed for nonclinical work of optimum translational value to predict possible adverse effects, identify sensitive developmental windows for the design and conduct of informative nonclinical and clinical studies, and explore the possibilities of organ-specific therapeutics.
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Affiliation(s)
- Elizabeth A Hausner
- United States Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland (E.A.H., X.Y.); and National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina (S.A.E.)
| | - Susan A Elmore
- United States Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland (E.A.H., X.Y.); and National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina (S.A.E.)
| | - Xi Yang
- United States Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland (E.A.H., X.Y.); and National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina (S.A.E.)
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Bai M, Zeng Q, Chen Y, Chen M, Li P, Ma Z, Sun D, Zhou H, Zheng C, Zeng S, Jiang H. Maternal Plasma l-Carnitine Reduction During Pregnancy Is Mainly Attributed to OCTN2-Mediated Placental Uptake and Does Not Result in Maternal Hepatic Fatty Acid β-Oxidation Decline. Drug Metab Dispos 2019; 47:582-591. [PMID: 30918014 DOI: 10.1124/dmd.119.086439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 03/22/2019] [Indexed: 12/25/2022] Open
Abstract
l-Carnitine (l-Car) plays a crucial role in fatty acid β-oxidation. However, the plasma l-Car concentration in women markedly declines during pregnancy, but the underlying mechanism and its consequences on maternal hepatic β-oxidation have not yet been clarified. Our results showed that the plasma l-Car level in mice at gestation day (GD) 18 was significantly lower than that in nonpregnant mice, and the mean fetal-to-maternal plasma l-Car ratio in GD 18 mice was 3.0. Carnitine/organic cation transporter 2 (OCTN2) was highly expressed in mouse and human placenta and upregulated as gestation proceeds in human placenta, whereas expressions of carnitine transporter (CT) 1, CT2, and amino acid transporter B0,+ were extremely low. Further study revealed that renal peroxisome proliferator-activated receptor α (PPARα) and OCTN2 were downregulated and the renal l-Car level was reduced, whereas the urinary excretion of l-Car was lower in late pregnant mice than in nonpregnant mice. Meanwhile, progesterone (pregnancy-related hormone) downregulated the expression of renal OCTN2 via PPARα-mediated pathway, and inhibited the activity of OCTN2, but estradiol, corticosterone, and cortisol did not. Unexpectedly, the maternal hepatic level of l-Car and β-hydroxybutyrate (an indicator of mitochondrial β-oxidation), and mRNA levels of several enzymes involved in fatty acid β-oxidation in GD 18 mice were higher than that in nonpregnant mice. In conclusion, OCTN2 mediated l-Car transfer across the placenta played a major role in maternal plasma l-Car reduction during pregnancy, which did not subsequently result in maternal hepatic fatty acid β-oxidation decrease.
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Affiliation(s)
- Mengru Bai
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Qingquan Zeng
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Yingchun Chen
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Mingyang Chen
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Ping Li
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Zhiyuan Ma
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Dongli Sun
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Hui Zhou
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Caihong Zheng
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Su Zeng
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
| | - Huidi Jiang
- Laboratory of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences (M.B., Y.C., M.C., P.L., Z.M., H.Z., S.Z., H.J.) and Women's Hospital, School of Medicine (Q.Z., D.S., C.Z.), Zhejiang University, Hangzhou, People's Republic of China
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Xue Y, Ma C, Hanna I, Pan G. Intestinal Transporter-Associated Drug Absorption and Toxicity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1141:361-405. [DOI: 10.1007/978-981-13-7647-4_8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Pochini L, Galluccio M, Scalise M, Console L, Indiveri C. OCTN: A Small Transporter Subfamily with Great Relevance to Human Pathophysiology, Drug Discovery, and Diagnostics. SLAS DISCOVERY 2018; 24:89-110. [PMID: 30523710 DOI: 10.1177/2472555218812821] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OCTN is a small subfamily of membrane transport proteins that belongs to the larger SLC22 family. Two of the three members of the subfamily, namely, OCTN2 and OCTN1, are present in humans. OCTN2 plays a crucial role in the absorption of carnitine from diet and in its distribution to tissues, as demonstrated by the occurrence of severe pathologies caused by malfunctioning or altered expression of this transporter. These findings suggest avoiding a strict vegetarian diet during pregnancy and in childhood. Other roles of OCTN2 are related to the traffic of carnitine derivatives in many tissues. The role of OCTN1 is still unclear, despite the identification of some substrates such as ergothioneine, acetylcholine, and choline. Plausibly, the transporter acts on the control of inflammation and oxidative stress, even though knockout mice do not display phenotypes. A clear role of both transporters has been revealed in drug interaction and delivery. The polyspecificity of the OCTNs is at the base of the interactions with drugs. Interestingly, OCTN2 has been recently exploited in the prodrug approach and in diagnostics. A promising application derives from the localization of OCTN2 in exosomes that represent a noninvasive diagnostic tool.
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Affiliation(s)
- Lorena Pochini
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Michele Galluccio
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Lara Console
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Cesare Indiveri
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy.,2 CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnology, Bari, Italy
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Ringseis R, Keller J, Eder K. Basic mechanisms of the regulation of L-carnitine status in monogastrics and efficacy of L-carnitine as a feed additive in pigs and poultry. J Anim Physiol Anim Nutr (Berl) 2018; 102:1686-1719. [PMID: 29992642 DOI: 10.1111/jpn.12959] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/20/2018] [Accepted: 06/22/2018] [Indexed: 12/19/2022]
Abstract
A great number of studies have investigated the potential of L-carnitine as feed additive to improve performance of different monogastric and ruminant livestock species, with, however, discrepant outcomes. In order to understand the reasons for these discrepant outcomes, it is important to consider the determinants of L-carnitine status and how L-carnitine status is regulated in the animal's body. While it is a long-known fact that L-carnitine is endogenously biosynthesized in certain tissues, it was only recently recognized that critical determinants of L-carnitine status, such as intestinal L-carnitine absorption, tissue L-carnitine uptake, endogenous L-carnitine synthesis and renal L-carnitine reabsorption, are regulated by specific nutrient sensing nuclear receptors. This review aims to give a more in-depth understanding of the basic mechanisms of the regulation of L-carnitine status in monogastrics taking into account the most recent evidence on nutrient sensing nuclear receptors and evaluates the efficacy of L-carnitine as feed additive in monogastric livestock by providing an up-to-date overview about studies with L-carnitine supplementation in pigs and poultry.
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Affiliation(s)
- Robert Ringseis
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Gießen, Gießen, Germany
| | - Janine Keller
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Gießen, Gießen, Germany
| | - Klaus Eder
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Gießen, Gießen, Germany
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Ringseis R, Keller J, Eder K. Regulation of carnitine status in ruminants and efficacy of carnitine supplementation on performance and health aspects of ruminant livestock: a review. Arch Anim Nutr 2018; 72:1-30. [PMID: 29313385 DOI: 10.1080/1745039x.2017.1421340] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Carnitine has long been known to play a critical role for energy metabolism. Due to this, a large number of studies have been carried out to investigate the potential of supplemental carnitine in improving performance of livestock animals including ruminants, with however largely inconsistent results. An important issue that has to be considered when using carnitine as a feed additive is that the efficacy of supplemental carnitine is probably dependent on the animal's carnitine status, which is affected by endogenous carnitine synthesis, carnitine uptake from the gastrointestinal tract and carnitine excretion. The present review aims to summarise the current knowledge of the regulation of carnitine status and carnitine homeostasis in ruminants, and comprehensively evaluate the efficacy of carnitine supplementation on performance and/or health in ruminant livestock by comparing the outcomes of studies with carnitine supplementation in dairy cattle, growing and finishing cattle and sheep. While most of the studies show that supplemental carnitine, even in ruminally unprotected form, is bioavailable in ruminants, its effect on either milk or growth performance is largely disappointing. However, supplemental carnitine appears to be a useful strategy to offer protection against ammonia toxicity caused by consumption of high levels of non-protein N or forages with high levels of soluble N both, in cattle and sheep.
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Affiliation(s)
- Robert Ringseis
- a Institute of Animal Nutrition and Nutrition Physiology , Justus-Liebig-University Gießen , Gießen , Germany
| | - Janine Keller
- a Institute of Animal Nutrition and Nutrition Physiology , Justus-Liebig-University Gießen , Gießen , Germany
| | - Klaus Eder
- a Institute of Animal Nutrition and Nutrition Physiology , Justus-Liebig-University Gießen , Gießen , Germany
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19
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Adeva-Andany MM, Calvo-Castro I, Fernández-Fernández C, Donapetry-García C, Pedre-Piñeiro AM. Significance of l-carnitine for human health. IUBMB Life 2017; 69:578-594. [PMID: 28653367 DOI: 10.1002/iub.1646] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/24/2017] [Indexed: 12/29/2022]
Abstract
Carnitine acyltransferases catalyze the reversible transfer of acyl groups from acyl-coenzyme A esters to l-carnitine, forming acyl-carnitine esters that may be transported across cell membranes. l-Carnitine is a wáter-soluble compound that humans may obtain both by food ingestion and endogenous synthesis from trimethyl-lysine. Most l-carnitine is intracellular, being present predominantly in liver, skeletal muscle, heart and kidney. The organic cation transporter-2 facilitates l-carnitine uptake inside cells. Congenital dysfunction of this transporter causes primary l-carnitine deficiency. Carnitine acetyltransferase is involved in the export of excess acetyl groups from the mitochondria and in acetylation reactions that regulate gene transcription and enzyme activity. Carnitine octanoyltransferase is a peroxysomal enzyme required for the complete oxidation of very long-chain fatty acids and phytanic acid, a branched-chain fatty acid. Carnitine palmitoyltransferase-1 is a transmembrane protein located on the outer mitochondrial membrane where it catalyzes the conversion of acyl-coenzyme A esters to acyl-carnitine esters. Carnitine acyl-carnitine translocase transports acyl-carnitine esters across the inner mitochondrial membrane in exchange for free l-carnitine that exits the mitochondrial matrix. Carnitine palmitoyltransferase-2 is anchored on the matrix side of the inner mitochondrial membrane, where it converts acyl-carnitine esters back to acyl-coenzyme A esters, which may be used in metabolic pathways, such as mitochondrial β-oxidation. l-Carnitine enhances nonoxidative glucose disposal under euglycemic hyperinsulinemic conditions in both healthy individuals and patients with type 2 diabetes, suggesting that l-carnitine strengthens insulin effect on glycogen storage. The plasma level of acyl-carnitine esters, primarily acetyl-carnitine, increases during diabetic ketoacidosis, fasting, and physical activity, particularly high-intensity exercise. Plasma concentration of free l-carnitine decreases simultaneously under these conditions. © 2017 IUBMB Life, 69(8):578-594, 2017.
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Warren JS, Oka SI, Zablocki D, Sadoshima J. Metabolic reprogramming via PPARα signaling in cardiac hypertrophy and failure: From metabolomics to epigenetics. Am J Physiol Heart Circ Physiol 2017. [PMID: 28646024 DOI: 10.1152/ajpheart.00103.2017] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Studies using omics-based approaches have advanced our knowledge of metabolic remodeling in cardiac hypertrophy and failure. Metabolomic analysis of the failing heart has revealed global changes in mitochondrial substrate metabolism. Peroxisome proliferator-activated receptor-α (PPARα) plays a critical role in synergistic regulation of cardiac metabolism through transcriptional control. Metabolic reprogramming via PPARα signaling in heart failure ultimately propagates into myocardial energetics. However, emerging evidence suggests that the expression level of PPARα per se does not always explain the energetic state in the heart. The transcriptional activities of PPARα are dynamic, yet highly coordinated. An additional level of complexity in the PPARα regulatory mechanism arises from its ability to interact with various partners, which ultimately determines the metabolic phenotype of the diseased heart. This review summarizes our current knowledge of the PPARα regulatory mechanisms in cardiac metabolism and the possible role of PPARα in epigenetic modifications in the diseased heart. In addition, we discuss how metabolomics can contribute to a better understanding of the role of PPARα in the progression of cardiac hypertrophy and failure.
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Affiliation(s)
- Junco Shibayama Warren
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah; .,Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Shin-Ichi Oka
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Daniela Zablocki
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey
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Amacher DE. The regulation of human hepatic drug transporter expression by activation of xenobiotic-sensing nuclear receptors. Expert Opin Drug Metab Toxicol 2016; 12:1463-1477. [PMID: 27548410 DOI: 10.1080/17425255.2016.1223626] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION If a drug is found to be an inducer of hepatic drug metabolizing enzymes via activation of nuclear receptors such as pregnane X receptor (PXR) or constitutive androstane receptor (CAR), it is likely that drug transporters regulated through these same receptors will be induced as well. This review highlights what is currently known about the molecular mechanisms that regulate transporter expression and where the research is directed. Areas covered: This review is focused on publications that describe the role of activated hepatic nuclear receptors in the subsequent regulation of drug uptake and/or efflux transporters following exposure to xenobiotics. Expert opinion: Many of the published studies on the role of nuclear receptors in the regulation of drug transporters involve non-human test animals. But due to species response differences, these associations are not always applicable to humans. For this reason, some relevant human in vitro models have been developed, such as primary or cryopreserved human hepatocytes, human liver slices, or HepG2 or HuH7 cell lines transiently or stably transfected with PXR expression and reporter constructs as well as in vivo models such as PXR-humanized mice. These human-relevant test systems will continue to be developed and applied for the testing of investigational drugs.
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Zhou X, Ringseis R, Wen G, Eder K. The pro-inflammatory cytokine tumor necrosis factor α stimulates expression of the carnitine transporter OCTN2 (novel organic cation transporter 2) and carnitine uptake via nuclear factor-κB in Madin-Darby bovine kidney cells. J Dairy Sci 2015; 98:3840-8. [PMID: 25892691 DOI: 10.3168/jds.2014-9044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 03/13/2015] [Indexed: 01/22/2023]
Abstract
Carnitine uptake into tissues is mediated mainly by the novel organic cation transporter 2 (OCTN2), whose expression is upregulated in the liver of early-lactating dairy cows. It has been shown recently that pro-inflammatory cytokines, including tumor necrosis factor α (TNFα), stimulate OCTN2 expression and carnitine uptake in intestinal cells and inflamed intestinal mucosa. Given that many early-lactating dairy cows show typical signs of hepatic and systemic inflammation, such as elevated concentrations of circulating TNFα and activation of the key regulator of inflammation, nuclear factor κB (NF-κB), in tissues, it is possible that upregulation of OCTN2 and increase of carnitine uptake by TNFα is mediated by NF-κB, a mechanism that might contribute to the upregulation of OCNT2 in the liver of early-lactating dairy cows. Thus, in the present study, we tested the hypothesis that TNFα stimulates OCTN2 gene expression and carnitine uptake via NF-κB in the bovine Madin-Darby bovine kidney (MDBK) cell line. Treatment with TNFα caused activation of NF-κB, increased the mRNA and protein concentration of OCTN2, and stimulated the uptake of carnitine in MDBK cells. In contrast, combined treatment of MDBK cells with TNFα and the NF-κB inhibitor BAY 11-7085 completely blocked the effect of TNFα on OCTN2 mRNA and protein concentration and uptake of carnitine. These findings suggest that the bovine OCTN2 gene and carnitine uptake are regulated by NF-κB. Future studies are required to show the in vivo relevance of this regulatory mechanism in cattle.
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Affiliation(s)
- X Zhou
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 26-32, D-35392 Gießen, Germany
| | - R Ringseis
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 26-32, D-35392 Gießen, Germany
| | - G Wen
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 26-32, D-35392 Gießen, Germany
| | - K Eder
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 26-32, D-35392 Gießen, Germany.
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