1
|
Ghaffari MH, Daniel JB, Sadri H, Schuchardt S, Martín-Tereso J, Sauerwein H. Longitudinal characterization of the metabolome of dairy cows transitioning from one lactation to the next: Investigations in blood serum. J Dairy Sci 2024; 107:1263-1285. [PMID: 37777004 DOI: 10.3168/jds.2023-23841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 09/07/2023] [Indexed: 10/02/2023]
Abstract
The objective of this study was to characterize changes in the serum metabolome and various indicators of oxidative balance in dairy cows starting 2 wk before dry-off and continuing until wk 16 of lactation. Twelve Holstein dairy cows (body weight 745 ± 71 kg, body condition score 3.43 ± 0.66; mean ± SD) were housed in a tiestall barn from 10 wk before to 16 wk after parturition. Cows were dried off 6 wk before the expected calving date (mean dry period length = 42 d). From 8 wk before calving to 16 wk after calving, blood samples were taken weekly to study redox metabolism by determining antioxidant capacity, measured as the ferric-reducing ability of plasma, reactive oxidative metabolites, oxidative stress index, oxidative damage of lipids, measured as thiobarbituric acid reactive substances, and glutathione peroxidase activity. According to these results, dairy cows had the lowest serum antioxidant capacity and greater levels of oxidative stress during the dry-off period and the early postpartum period. For metabolomics, a subset of serum samples including wk -7 (before dry-off), -5 (after dry-off), -1, 1, 5, 10, and 15 relative to calving were used. A targeted metabolomics approach was performed using liquid chromatography and flow injection with electrospray ionization triple quadrupole mass spectrometry using the MxP Quant 500 kit (Biocrates Life Sciences AG). A total of 240 metabolites in serum were used in the final data analysis. Principal component analysis revealed a clear separation by days of sampling, indicating a remarkable shift in metabolic phenotype between the dry period and late and early lactation. Changes in many non-lipid metabolites associated with one-carbon metabolism, the tricarboxylic acid cycle, the urea cycle, and AA catabolism were observed in the study, with changes in AA serum concentrations likely related to factors such as energy and nitrogen balance, digestive efficiency, and changing diets. The study confirmed an extensive remodeling of the serum lipidome in peripartum dairy cows, highlighting the importance of changes in acylcarnitine (acylCN), phosphatidylcholines (PC), and triacylglycerols (TG), as they play a crucial role in lipid metabolism. Results showed that short-chain acylCN increased after dry-off and decreased thereafter, whereas lipid-derived acylCN increased around parturition, suggesting that more fatty acids could enter mitochondria. Phospholipids and sphingolipids in serum showed changes during lactation. In particular, concentrations of sphingomyelins, PC, and lysoPC decreased around calving but increased in mid- and late lactation. In contrast, concentrations of TG remained consistently low after parturition. The serum concentrations of bile acids fluctuated during the dry period and lactation, with glycocholic acid, cholic acid, glycodeoxycholic acid, and taurocholic acid showing the greatest concentrations. These changes are likely due to the interplay of diet, liver function, and the ability of the gut microbiota to convert primary to secondary bile acids. Overall, these descriptive results may aid in hypothesis generation and in the design and interpretation of future metabolite-based studies in dairy cows. Furthermore, they contribute to our understanding of the physiological ranges in serum metabolites relative to the lactation cycle of the dairy cow.
Collapse
Affiliation(s)
- M H Ghaffari
- Institute of Animal Science, Physiology Unit, University of Bonn, 53115 Bonn, Germany.
| | - J B Daniel
- Trouw Nutrition R&D, 3800 AG, Amersfoort, the Netherlands.
| | - H Sadri
- Department of Clinical Science, Faculty of Veterinary Medicine, University of Tabriz, 5166616471 Tabriz, Iran
| | - S Schuchardt
- Fraunhofer Institute for Toxicology and Experimental Medicine, 30625 Hannover, Germany
| | | | - H Sauerwein
- Institute of Animal Science, Physiology Unit, University of Bonn, 53115 Bonn, Germany
| |
Collapse
|
2
|
Chen S, Shao Q, Chen J, Lv X, Ji J, Liu Y, Song Y. Bile acid signalling and its role in anxiety disorders. Front Endocrinol (Lausanne) 2023; 14:1268865. [PMID: 38075046 PMCID: PMC10710157 DOI: 10.3389/fendo.2023.1268865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/06/2023] [Indexed: 12/18/2023] Open
Abstract
Anxiety disorder is a prevalent neuropsychiatric disorder that afflicts 7.3%~28.0% of the world's population. Bile acids are synthesized by hepatocytes and modulate metabolism via farnesoid X receptor (FXR), G protein-coupled receptor (TGR5), etc. These effects are not limited to the gastrointestinal tract but also extend to tissues and organs such as the brain, where they regulate emotional centers and nerves. A rise in serum bile acid levels can promote the interaction between central FXR and TGR5 across the blood-brain barrier or activate intestinal FXR and TGR5 to release fibroblast growth factor 19 (FGF19) and glucagon-like peptide-1 (GLP-1), respectively, which in turn, transmit signals to the brain via these indirect pathways. This review aimed to summarize advancements in the metabolism of bile acids and the physiological functions of their receptors in various tissues, with a specific focus on their regulatory roles in brain function. The contribution of bile acids to anxiety via sending signals to the brain via direct or indirect pathways was also discussed. Different bile acid ligands trigger distinct bile acid signaling cascades, producing diverse downstream effects, and these pathways may be involved in anxiety regulation. Future investigations from the perspective of bile acids are anticipated to lead to novel mechanistic insights and potential therapeutic targets for anxiety disorders.
Collapse
Affiliation(s)
| | | | | | | | | | - Yan Liu
- College of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Yuehan Song
- College of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| |
Collapse
|
3
|
Harnisch LO, Neugebauer S, Mihaylov D, Eidizadeh A, Zechmeister B, Maier I, Moerer O. Quantification of Bile Acids in Cerebrospinal Fluid: Results of an Observational Trial. Biomedicines 2023; 11:2947. [PMID: 38001948 PMCID: PMC10669160 DOI: 10.3390/biomedicines11112947] [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: 09/17/2023] [Revised: 10/26/2023] [Accepted: 10/30/2023] [Indexed: 11/26/2023] Open
Abstract
(1) Background: Bile acids, known as aids in intestinal fat digestion and as messenger molecules in serum, can be detected in cerebrospinal fluid (CSF), although the blood-brain barrier is generally an insurmountable obstacle for bile acids. The exact mechanisms of the occurrence, as well as possible functions of bile acids in the central nervous system, are not precisely understood. (2) Methods: We conducted a single-center observational trial. The concentrations of 15 individual bile acids were determined using an in-house LC-MS/MS method in 54 patients with various acute and severe disorders of the central nervous system. We analyzed CSF from ventricular drainage taken within 24 h after placement, and blood samples were drawn at the same time for the presence and quantifiability of 15 individual bile acids. (3) Results: At a median time of 19.75 h after a cerebral insult, the concentration of bile acids in the CSF was minute and almost negligible. The CSF concentrations of total bile acids (TBAs) were significantly lower compared to the serum concentrations (serum 0.37 µmol/L [0.24, 0.89] vs. 0.14 µmol/L [0.05, 0.43]; p = 0.033). The ratio of serum-to-CSF bile acid levels calculated from the respective total concentrations were 3.10 [0.94, 14.64] for total bile acids, 3.05 for taurocholic acid, 14.30 [1.11, 27.13] for glycocholic acid, 0.0 for chenodeoxycholic acid, 2.19 for taurochenodeoxycholic acid, 1.91 [0.68, 8.64] for glycochenodeoxycholic acid and 0.77 [0.0, 13.79] for deoxycholic acid; other bile acids were not detected in the CSF. The ratio of CSF-to-serum S100 concentration was 0.01 [0.0, 0.02]. Serum total and conjugated (but not unconjugated) bilirubin levels and serum TBA levels were significantly correlated (total bilirubin p = 0.031 [0.023, 0.579]; conjugated bilirubin p = 0.001 [0.193, 0.683]; unconjugated p = 0.387 [-0.181, 0.426]). No correlations were found between bile acid concentrations and age, delirium, intraventricular blood volume, or outcome measured on a modified Rankin scale. (4) Conclusions: The determination of individual bile acids is feasible using the current LC-MS/MS method. The results suggest an intact blood-brain barrier in the patients studied. However, bile acids were detected in the CSF, which could have been achieved by active transport across the blood-brain barrier.
Collapse
Affiliation(s)
- Lars-Olav Harnisch
- Department of Anaesthesiology, University Medical Center, University of Göttingen, Robert-Koch-Str. 40, D-37075 Göttingen, Germany;
| | - Sophie Neugebauer
- Institute of Clinical Chemistry and Laboratory Diagnostics, University Hospital Jena, Am Klinikum 1, D-07747 Jena, Germany; (S.N.); (D.M.)
| | - Diana Mihaylov
- Institute of Clinical Chemistry and Laboratory Diagnostics, University Hospital Jena, Am Klinikum 1, D-07747 Jena, Germany; (S.N.); (D.M.)
| | - Abass Eidizadeh
- Interdisciplinary UMG Laboratories, University Medical Center, University of Göttingen, Robert-Koch-Str. 40, D-37075 Göttingen, Germany; (A.E.); (B.Z.)
| | - Bozena Zechmeister
- Interdisciplinary UMG Laboratories, University Medical Center, University of Göttingen, Robert-Koch-Str. 40, D-37075 Göttingen, Germany; (A.E.); (B.Z.)
| | - Ilko Maier
- Department of Neurology, University Medical Center, University of Göttingen, Robert-Koch-Str. 40, D-37075 Göttingen, Germany;
| | - Onnen Moerer
- Department of Anaesthesiology, University Medical Center, University of Göttingen, Robert-Koch-Str. 40, D-37075 Göttingen, Germany;
| |
Collapse
|
4
|
Tempra C, Brkljača Z, Vazdar M. Why do polyarginines adsorb at neutral phospholipid bilayers and polylysines do not? An insight from density functional theory calculations and molecular dynamics simulations. Phys Chem Chem Phys 2023; 25:27204-27214. [PMID: 37791394 DOI: 10.1039/d3cp02411c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Adsorption of cell-penetrating peptides (CPPs) at cellular membranes is the first and necessary step for their subsequent translocation across cellular membranes into the cytosol. It has been experimentally shown that CPPs rich in arginine (Arg) amino acid penetrate across phospholipid bilayers more effectively than their lysine (Lys) rich counterparts. In this work, we aim to understand the differences in the first translocation step, adsorption of Arg9 and Lys9 peptides at fully hydrated neutral phosphatidylcholine (PC) and phosphatidylethanolamine (PE) lipid bilayers and evaluate in detail the energetics of the process using molecular dynamics (MD) simulations and free energy calculations of adsorption of the single peptide. We show that the adsorption of Arg9 is energetically feasible, with the free energy of adsorption being ∼-5.0 kcal mol-1 at PC and ∼-5.5 kcal mol-1 at PE bilayers. In contrast, adsorption of Lys9 is not observed at PC bilayers, and their adsorption at PE bilayers is very weak, being ∼-0.5 kcal mol-1. We show by energy decomposition and analysis of peptide hydration along the membrane that significantly stronger electrostatic interactions of Arg9 with lipid phosphate groups, together with the greater loss of peptide hydration (and in turn stronger hydrophobic interactions) along the membrane translocation path, are the main driving factors governing the adsorption of Arg-rich peptides at neutral lipid bilayers in contrast to Lys-rich peptides. Finally, we also compare the energetics in lipid/bilayer systems with the density functional theory (DFT) calculations of the corresponding model systems in the continuum water model and reveal the energetic differences in different environments.
Collapse
Affiliation(s)
- Carmelo Tempra
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 16000 Prague, Czech Republic
| | - Zlatko Brkljača
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Mario Vazdar
- Department of Mathematics, Informatics, and Cybernetics, University of Chemistry and Technology, Technická 5, 16628 Prague, Czech Republic.
| |
Collapse
|
5
|
Zhu G, Zhao J, Zhang H, Wang G, Chen W. Gut Microbiota and its Metabolites: Bridge of Dietary Nutrients and Alzheimer's Disease. Adv Nutr 2023; 14:819-839. [PMID: 37075947 PMCID: PMC10334159 DOI: 10.1016/j.advnut.2023.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/29/2023] [Accepted: 04/14/2023] [Indexed: 04/21/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive impairment and neuroinflammation. Recent research has revealed the crucial role of gut microbiota and microbial metabolites in modulating AD. However, the mechanisms by which the microbiome and microbial metabolites affect brain function remain poorly understood. Here, we review the literature on changes in the diversity and composition of the gut microbiome in patients with AD and in animal models of AD. We also discuss the latest progress in understanding the pathways by which the gut microbiota and microbial metabolites from the host or diet regulate AD. By understanding the effects of dietary components on brain function, microbiota composition, and microbial metabolites, we examine the potential for manipulation of the gut microbiota through dietary intervention to delay the progression of AD. Although it is challenging to translate our understanding of microbiome-based approaches to dietary guidelines or clinical therapies, these findings provide an attractive target for promoting brain function.
Collapse
Affiliation(s)
- Guangsu Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; College of Food Science and Technology, Henan University of Technology, Zhengzhou, Henan, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; (Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, Jiangsu, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; (Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, Jiangsu, China; National Engineering Center for Functional Food, Jiangnan University, Wuxi, Jiangsu, China
| | - Gang Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; (Yangzhou) Institute of Food Biotechnology, Jiangnan University, Yangzhou, Jiangsu, China.
| | - Wei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; National Engineering Center for Functional Food, Jiangnan University, Wuxi, Jiangsu, China
| |
Collapse
|
6
|
Samartsev VN, Khoroshavina EI, Pavlova EK, Dubinin MV, Semenova AA. Bile Acids as Inducers of Protonophore and Ionophore Permeability of Biological and Artificial Membranes. MEMBRANES 2023; 13:membranes13050472. [PMID: 37233533 DOI: 10.3390/membranes13050472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/26/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023]
Abstract
It is now generally accepted that the role of bile acids in the organism is not limited to their participation in the process of food digestion. Indeed, bile acids are signaling molecules and being amphiphilic compounds, are also capable of modifying the properties of cell membranes and their organelles. This review is devoted to the analysis of data on the interaction of bile acids with biological and artificial membranes, in particular, their protonophore and ionophore effects. The effects of bile acids were analyzed depending on their physicochemical properties: namely the structure of their molecules, indicators of the hydrophobic-hydrophilic balance, and the critical micelle concentration. Particular attention is paid to the interaction of bile acids with the powerhouse of cells, the mitochondria. It is of note that bile acids, in addition to their protonophore and ionophore actions, can also induce Ca2+-dependent nonspecific permeability of the inner mitochondrial membrane. We consider the unique action of ursodeoxycholic acid as an inducer of potassium conductivity of the inner mitochondrial membrane. We also discuss a possible relationship between this K+ ionophore action of ursodeoxycholic acid and its therapeutic effects.
Collapse
Affiliation(s)
- Victor N Samartsev
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Ekaterina I Khoroshavina
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Evgeniya K Pavlova
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Mikhail V Dubinin
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Alena A Semenova
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| |
Collapse
|
7
|
Kiriyama Y, Nochi H. Role of Microbiota-Modified Bile Acids in the Regulation of Intracellular Organelles and Neurodegenerative Diseases. Genes (Basel) 2023; 14:825. [PMID: 37107583 PMCID: PMC10137455 DOI: 10.3390/genes14040825] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 04/29/2023] Open
Abstract
Bile acids (BAs) are amphiphilic steroidal molecules generated from cholesterol in the liver and facilitate the digestion and absorption of fat-soluble substances in the gut. Some BAs in the intestine are modified by the gut microbiota. Because BAs are modified in a variety of ways by different types of bacteria present in the gut microbiota, changes in the gut microbiota can affect the metabolism of BAs in the host. Although most BAs absorbed from the gut are transferred to the liver, some are transferred to the systemic circulation. Furthermore, BAs have also been detected in the brain and are thought to migrate into the brain through the systemic circulation. Although BAs are known to affect a variety of physiological functions by acting as ligands for various nuclear and cell-surface receptors, BAs have also been found to act on mitochondria and autophagy in the cell. This review focuses on the BAs modified by the gut microbiota and their roles in intracellular organelles and neurodegenerative diseases.
Collapse
Affiliation(s)
- Yoshimitsu Kiriyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Kagawa 769-2193, Japan
- Institute of Neuroscience, Tokushima Bunri University, Kagawa 769-2193, Japan
| | - Hiromi Nochi
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Kagawa 769-2193, Japan
| |
Collapse
|
8
|
Truong JK, Li J, Li Q, Pachura K, Rao A, Gumber S, Fuchs CD, Feranchak AP, Karpen SJ, Trauner M, Dawson PA. Active enterohepatic cycling is not required for the choleretic actions of 24-norUrsodeoxycholic acid in mice. JCI Insight 2023; 8:e149360. [PMID: 36787187 PMCID: PMC10070106 DOI: 10.1172/jci.insight.149360] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 02/07/2023] [Indexed: 02/15/2023] Open
Abstract
The pronounced choleretic properties of 24-norUrsodeoxycholic acid (norUDCA) to induce bicarbonate-rich bile secretion have been attributed to its ability to undergo cholehepatic shunting. The goal of this study was to identify the mechanisms underlying the choleretic actions of norUDCA and the role of the bile acid transporters. Here, we show that the apical sodium-dependent bile acid transporter (ASBT), organic solute transporter-α (OSTα), and organic anion transporting polypeptide 1a/1b (OATP1a/1b) transporters are dispensable for the norUDCA stimulation of bile flow and biliary bicarbonate secretion. Chloride channels in biliary epithelial cells provide the driving force for biliary secretion. In mouse large cholangiocytes, norUDCA potently stimulated chloride currents that were blocked by siRNA silencing and pharmacological inhibition of calcium-activated chloride channel transmembrane member 16A (TMEM16A) but unaffected by ASBT inhibition. In agreement, blocking intestinal bile acid reabsorption by coadministration of an ASBT inhibitor or bile acid sequestrant did not impact norUDCA stimulation of bile flow in WT mice. The results indicate that these major bile acid transporters are not directly involved in the absorption, cholehepatic shunting, or choleretic actions of norUDCA. Additionally, the findings support further investigation of the therapeutic synergy between norUDCA and ASBT inhibitors or bile acid sequestrants for cholestatic liver disease.
Collapse
Affiliation(s)
- Jennifer K. Truong
- Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology and Nutrition, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Jianing Li
- Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology and Nutrition, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Qin Li
- Department of Pediatrics, University of Pittsburgh Medical Center Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kimberly Pachura
- Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology and Nutrition, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Anuradha Rao
- Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology and Nutrition, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Sanjeev Gumber
- Division of Pathology and Laboratory Medicine, Yerkes National Research Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Claudia Daniela Fuchs
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Andrew P. Feranchak
- Department of Pediatrics, University of Pittsburgh Medical Center Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Saul J. Karpen
- Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology and Nutrition, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Michael Trauner
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Paul A. Dawson
- Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology and Nutrition, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| |
Collapse
|
9
|
Lai Y, Dhingra R, Zhang Z, Ball LM, Zylka MJ, Lu K. Toward Elucidating the Human Gut Microbiota-Brain Axis: Molecules, Biochemistry, and Implications for Health and Diseases. Biochemistry 2022; 61:2806-2821. [PMID: 34910469 PMCID: PMC10857864 DOI: 10.1021/acs.biochem.1c00656] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In recent years, a substantial amount of data have supported an active role of gut microbiota in mediating mammalian brain function and health. Mining gut microbiota and their metabolites for neuroprotection is enticing but requires that the fundamental biochemical details underlying such microbiota-brain crosstalk be deciphered. While a neuronal gut-brain axis (through the vagus nerve) is not disputable, accumulating studies also point to a humoral route (via blood/lymphatic circulation) by which innumerable microbial molecular cues translocate from local gut epithelia to circulation with potentials to further cross the blood-brain barrier and reach the brain. In this Perspective, we review a realm of gut microbial molecules to evaluate their fate, function, and neuroactivities in vivo as mediated by microbiota. We turn to seminal studies of neurophysiology and neurologic disease models for the elucidation of biochemical pathways that link microbiota to gut-brain signaling. In addition, we discuss opportunities and challenges for advancing the microbiota-brain axis field while calling for high-throughput discovery of microbial molecules and studies for resolving the interspecies, interorgan, and interclass interaction among these neuroactive microbial molecules.
Collapse
Affiliation(s)
- Yunjia Lai
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Campus Box 7431, Chapel Hill, North Carolina 27599, United States
| | - Radhika Dhingra
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Campus Box 7431, Chapel Hill, North Carolina 27599, United States
- Institute of Environmental Health Solutions, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Zhenfa Zhang
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Campus Box 7431, Chapel Hill, North Carolina 27599, United States
| | - Louise M Ball
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Campus Box 7431, Chapel Hill, North Carolina 27599, United States
| | - Mark J Zylka
- UNC Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Carolina Institute for Developmental Disabilities, The University of North Carolina at Chapel Hill, Carrboro, North Carolina 27510, United States
- Department of Cell and Molecular Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Kun Lu
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Campus Box 7431, Chapel Hill, North Carolina 27599, United States
- Curriculum in Toxicology and Environmental Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| |
Collapse
|
10
|
Qing Y, Wang P, Cui G, Zhang J, Liang K, Xia Z, Wang P, He L, Jia W. Targeted metabolomics reveals aberrant profiles of serum bile acids in patients with schizophrenia. SCHIZOPHRENIA 2022; 8:65. [PMID: 35982185 PMCID: PMC9388515 DOI: 10.1038/s41537-022-00273-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/01/2022] [Indexed: 11/21/2022]
Abstract
Emerging evidence indicates that bile acids (BAs), which are signaling molecules that regulate metabolism and inflammation, appear to be dysregulated in schizophrenia (SZ). Further investigation is warranted to comprehensively characterize BA profiles in SZ. To address this, we analyzed serum BA profiles in 108 drug-free patients with SZ and in 108 healthy controls (HCs), divided into a discovery set (n = 119) and a validation set (n = 97), using ultraperformance liquid chromatography triple quadrupole mass spectrometry. Forty serum BAs were detected and absolutely quantified using calibration curves. Global BA profiling showed differences in SZ and HC groups in both discovery and validation sets. The concentrations of chenodeoxycholic acid, ursodeoxycholic acid, 3β-chenodeoxycholic acid, 7-ketolithocholic acid, 3-dehydrocholic acid, total BAs, and unconjugated BAs were significantly lower in patients with SZ compared with HCs in the two sample sets. The BA deconjugation potentials by gut microbiota and the affinity index of the farnesoid X receptor (FXR) were notably decreased in SZ patients compared to those of HCs. Conjugated BAs and BA deconjugation potentials differed in SZ patients with first versus recurrent episodes, although similar BA profiles were observed in both groups. In addition, a panel of 8 BA variables acted as a potential auxiliary diagnostic biomarker in discriminating SZ patients from HCs, with area under the curve values for receiver operating characteristic curves of 0.758 and 0.732 and for precision-recall curves of 0.750 and 0.714 in the discovery and validation sets, respectively. This study has provided compelling evidence of comprehensive characteristics of circulating BA metabolism in patients with SZ and promoted a deeper understanding of the role of BAs in the pathophysiology of this disease, possibly via the gut microbiota-FXR signaling pathway.
Collapse
|
11
|
Microbial-derived metabolites as a risk factor of age-related cognitive decline and dementia. Mol Neurodegener 2022; 17:43. [PMID: 35715821 PMCID: PMC9204954 DOI: 10.1186/s13024-022-00548-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/30/2022] [Indexed: 02/06/2023] Open
Abstract
A consequence of our progressively ageing global population is the increasing prevalence of worldwide age-related cognitive decline and dementia. In the absence of effective therapeutic interventions, identifying risk factors associated with cognitive decline becomes increasingly vital. Novel perspectives suggest that a dynamic bidirectional communication system between the gut, its microbiome, and the central nervous system, commonly referred to as the microbiota-gut-brain axis, may be a contributing factor for cognitive health and disease. However, the exact mechanisms remain undefined. Microbial-derived metabolites produced in the gut can cross the intestinal epithelial barrier, enter systemic circulation and trigger physiological responses both directly and indirectly affecting the central nervous system and its functions. Dysregulation of this system (i.e., dysbiosis) can modulate cytotoxic metabolite production, promote neuroinflammation and negatively impact cognition. In this review, we explore critical connections between microbial-derived metabolites (secondary bile acids, trimethylamine-N-oxide (TMAO), tryptophan derivatives and others) and their influence upon cognitive function and neurodegenerative disorders, with a particular interest in their less-explored role as risk factors of cognitive decline.
Collapse
|
12
|
Metzendorf NG, Lange LM, Lainer N, Schlüter R, Dittmann S, Paul LS, Troitzsch D, Sievers S. Destination and Specific Impact of Different Bile Acids in the Intestinal Pathogen Clostridioides difficile. Front Microbiol 2022; 13:814692. [PMID: 35401433 PMCID: PMC8989276 DOI: 10.3389/fmicb.2022.814692] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 02/09/2022] [Indexed: 01/05/2023] Open
Abstract
The anaerobic bacterium Clostridioides difficile represents one of the most problematic pathogens, especially in hospitals. Dysbiosis has been proven to largely reduce colonization resistance against this intestinal pathogen. The beneficial effect of the microbiota is closely associated with the metabolic activity of intestinal microbes such as the ability to transform primary bile acids into secondary ones. However, the basis and the molecular action of bile acids (BAs) on the pathogen are not well understood. We stressed the pathogen with the four most abundant human bile acids: cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA) and lithocholic acid (LCA). Thin layer chromatography (TLC), confocal laser scanning microscopy (CLSM), and electron microscopy (EM) were employed to track the enrichment and destination of bile acids in the bacterial cell. TLC not only revealed a strong accumulation of LCA in C. difficile, but also indicated changes in the composition of membrane lipids in BA-treated cells. Furthermore, morphological changes induced by BAs were determined, most pronounced in the virtually complete loss of flagella in LCA-stressed cells and a flagella reduction after DCA and CDCA challenge. Quantification of both, protein and RNA of the main flagella component FliC proved the decrease in flagella to originate from a change in gene expression on transcriptional level. Notably, the loss of flagella provoked by LCA did not reduce adhesion ability of C. difficile to Caco-2 cells. Most remarkably, extracellular toxin A levels in the presence of BAs showed a similar pattern as flagella expression. That is, CA did not affect toxin expression, whereas lower secretion of toxin A was determined in cells stressed with LCA, DCA or CDCA. In summary, the various BAs were shown to differentially modify virulence determinants, such as flagella expression, host cell adhesion and toxin synthesis. Our results indicate differences of BAs in cellular localization and impact on membrane composition, which could be a reason of their diverse effects. This study is a starting point in the elucidation of the molecular mechanisms underlying the differences in BA action, which in turn can be vital regarding the outcome of a C. difficile infection.
Collapse
Affiliation(s)
| | - Lena Melanie Lange
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Nina Lainer
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Rabea Schlüter
- Imaging Center of the Department of Biology, University of Greifswald, Greifswald, Germany
| | - Silvia Dittmann
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Lena-Sophie Paul
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Daniel Troitzsch
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Susanne Sievers
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
- *Correspondence: Susanne Sievers,
| |
Collapse
|
13
|
Qu Y, Su C, Zhao Q, Shi A, Zhao F, Tang L, Xu D, Xiang Z, Wang Y, Wang Y, Pan J, Yu Y. Gut Microbiota-Mediated Elevated Production of Secondary Bile Acids in Chronic Unpredictable Mild Stress. Front Pharmacol 2022; 13:837543. [PMID: 35321330 PMCID: PMC8936594 DOI: 10.3389/fphar.2022.837543] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 01/25/2022] [Indexed: 01/04/2023] Open
Abstract
A growing body of evidence suggests that gut microbiota could participate in the progression of depression via the microbiota–gut–brain axis. However, the detailed microbial metabolic profile changes in the progression of depression is still not fully elucidated. In this study, a liquid chromatography coupled to mass spectrometry-based untargeted serum high-throughput metabolomics method was first performed to screen for potential biomarkers in a depressive-like state in a chronic unpredictable mild stress (CUMS)-induced mouse model. Our results identified that the bile acid and energy metabolism pathways were significantly affected in CUMS progression. The detailed bile acid profiles were subsequently quantified in the serum, liver, and feces. The results showed that CUMS significantly promoted the deconjugation of conjugated bile acid and secondary bile acid biosynthesis. Furthermore, 16S rRNA gene sequencing revealed that the increased secondary bile acid levels in the feces positively correlated with Ruminococcaceae_UCG-010, Ruminococcus, and Clostridia_UCG-014 abundance. Taken together, our study suggested that changes in family Ruminococcaceae abundance following chronic stress increased biosynthesis of deoxycholic acid (DCA), a unconjugated secondary bile acid in the intestine. Aberrant activation of secondary bile acid biosynthesis pathway thereby increased the hydrophobicity of the bile acid pool, which might, in turn, promoted metabolic disturbances and disease progression in CUMS mice.
Collapse
Affiliation(s)
- Yuchen Qu
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Cunjin Su
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Qinhong Zhao
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Aiming Shi
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Fenglun Zhao
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Liuxing Tang
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Delai Xu
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Zheng Xiang
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Yang Wang
- College of Pharmaceutical Science, Soochow University, Suzhou, China
| | - Yueyuan Wang
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Jie Pan
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Yunli Yu, ; Jie Pan,
| | - Yunli Yu
- Department of Pharmacy, The Second Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Yunli Yu, ; Jie Pan,
| |
Collapse
|
14
|
Kiriyama Y, Nochi H. Physiological Role of Bile Acids Modified by the Gut Microbiome. Microorganisms 2021; 10:68. [PMID: 35056517 PMCID: PMC8777643 DOI: 10.3390/microorganisms10010068] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/21/2021] [Accepted: 12/29/2021] [Indexed: 12/13/2022] Open
Abstract
Bile acids (BAs) are produced from cholesterol in the liver and are termed primary BAs. Primary BAs are conjugated with glycine and taurine in the liver and then released into the intestine via the gallbladder. After the deconjugation of glycine or taurine by the gut microbiome, primary BAs are converted into secondary BAs by the gut microbiome through modifications such as dehydroxylation, oxidation, and epimerization. Most BAs in the intestine are reabsorbed and transported to the liver, where both primary and secondary BAs are conjugated with glycine or taurine and rereleased into the intestine. Thus, unconjugated primary Bas, as well as conjugated and unconjugated secondary BAs, have been modified by the gut microbiome. Some of the BAs reabsorbed from the intestine spill into the systemic circulation, where they bind to a variety of nuclear and cell-surface receptors in tissues, whereas some of the BAs are not reabsorbed and bind to receptors in the terminal ileum. BAs play crucial roles in the physiological regulation of various tissues. Furthermore, various factors, such as diet, age, and antibiotics influence BA composition. Here, we review recent findings regarding the physiological roles of BAs modified by the gut microbiome in the metabolic, immune, and nervous systems.
Collapse
Affiliation(s)
- Yoshimitsu Kiriyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Sanuki 769-2193, Kagawa, Japan;
- Laboratory of Neuroendocrinology, Institute of Neuroscience, Tokushima Bunri University, Shido 1314-1, Sanuki 769-2193, Kagawa, Japan
| | - Hiromi Nochi
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Sanuki 769-2193, Kagawa, Japan;
| |
Collapse
|
15
|
Pei Y, Cheng F, Li W, Yu Q, Ma C, Zou Y, Xu T, Liu S, Zhang S, Wang Q. Enhancement of anti-inflammatory effect of cattle bile by fermentation and its inhibition of neuroinflammation on microglia by inhibiting NLRP3 inflammasome. J Biosci Bioeng 2021; 133:146-154. [PMID: 34887181 DOI: 10.1016/j.jbiosc.2021.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/01/2021] [Accepted: 11/08/2021] [Indexed: 11/20/2022]
Abstract
As a kind of animal medicine, cattle bile has anti-inflammatory, antipyretic and cholagogic effects. The fermentation process of cattle bile is included in the application of many traditional Chinese medicines. In this study, we fermented cattle bile singly and investigated the impact of fermentation on the anti-inflammatory effect of cattle bile, as well as the mechanism of fermented cattle bile on microglia cells. After high temperature sterilization, cattle bile was fermented with Massa Medicata Fermentata (medicated leaven, Shen Qu). We used ultra-high performance liquid chromatography-mass spectrometry/mass spectrometry (UHPLC-MS/MS) to analyze the bile acids of cattle bile and fermented cattle bile. The results showed that 3-dehydrocholic acid, 7-ketolithocholic acid, 12-dehydrocholic acid, 12-Ketolithocholic acid, ursodeoxycholic acid and dehydrolithocholic acid increased more significantly than others; glycocholic acid and glycochenodeoxycholic acid decreased more significantly than others. After fermentation, cattle bile significantly reduced the release of NO and inflammatory factors (TNF-α and IL-1β). Furthermore, the protein expression of TNF-α, IL-1β and iNOS were decreased. In addition, we found that fermented cattle bile could have an anti-inflammatory effect through attenuating the activation of NLRP3 inflammasome. Thus, fermentation can enhance the anti-inflammatory effect of cattle bile. Fermented cattle bile has an anti-inflammatory effect by inhibiting the NLRP3 inflammasome pathway, which can expand the clinical application of cattle bile and provide new thoughts and methods for the application of cattle bile.
Collapse
Affiliation(s)
- Yuying Pei
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Fafeng Cheng
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Wei Li
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Qiaoyu Yu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Chongyang Ma
- School of Chinese Medicine, Capital Medical University, Beijing 100069, China
| | - Yan Zou
- Shineway Pharmaceutical Group Ltd., Shijiazhuang 051430, China
| | - Tian Xu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Shuling Liu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Shuang Zhang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Qingguo Wang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China.
| |
Collapse
|
16
|
Ohnishi S, Kamiya K. Formation of Giant Lipid Vesicle Containing Dual Functions Facilitates Outer Membrane Phospholipase. ACS Synth Biol 2021; 10:1837-1846. [PMID: 34258991 DOI: 10.1021/acssynbio.0c00468] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Giant lipid vesicles are used to study artificial cell models, as well as the encapsulation of biomolecules, and the reconstitution of membrane proteins on these vesicles. Recently, complex reactions in giant vesicles have been controlled by reconstituting numerous kinds of biomolecules. However, it is challenging to generate giant lipid vesicles containing a diverse set of proteins at concentrations sufficient to ensure proper functioning. Here, we describe an artificial cell model showing dual functions of small molecule transportation and small vesicle budding, using a dual functional membrane protein (transportation and phosphatase activity) called the outer membrane phospholipase (OmpLA). To the best of our knowledge, we have revealed for the first time the transportation of ions or small molecules through OmpLA on the charged lipid bilayer. The lipid composition controlled the orientation of OmpLA through proteinase K digestion. Finally, OmpLA enzyme activity of phospholipid hydrolysis caused the budding of small vesicles.
Collapse
Affiliation(s)
- Seren Ohnishi
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Koki Kamiya
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| |
Collapse
|
17
|
Varma VR, Wang Y, An Y, Varma S, Bilgel M, Doshi J, Legido-Quigley C, Delgado JC, Oommen AM, Roberts JA, Wong DF, Davatzikos C, Resnick SM, Troncoso JC, Pletnikova O, O’Brien R, Hak E, Baak BN, Pfeiffer R, Baloni P, Mohmoudiandehkordi S, Nho K, Kaddurah-Daouk R, Bennett DA, Gadalla SM, Thambisetty M. Bile acid synthesis, modulation, and dementia: A metabolomic, transcriptomic, and pharmacoepidemiologic study. PLoS Med 2021; 18:e1003615. [PMID: 34043628 PMCID: PMC8158920 DOI: 10.1371/journal.pmed.1003615] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/06/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND While Alzheimer disease (AD) and vascular dementia (VaD) may be accelerated by hypercholesterolemia, the mechanisms underlying this association are unclear. We tested whether dysregulation of cholesterol catabolism, through its conversion to primary bile acids (BAs), was associated with dementia pathogenesis. METHODS AND FINDINGS We used a 3-step study design to examine the role of the primary BAs, cholic acid (CA), and chenodeoxycholic acid (CDCA) as well as their principal biosynthetic precursor, 7α-hydroxycholesterol (7α-OHC), in dementia. In Step 1, we tested whether serum markers of cholesterol catabolism were associated with brain amyloid accumulation, white matter lesions (WMLs), and brain atrophy. In Step 2, we tested whether exposure to bile acid sequestrants (BAS) was associated with risk of dementia. In Step 3, we examined plausible mechanisms underlying these findings by testing whether brain levels of primary BAs and gene expression of their principal receptors are altered in AD. Step 1: We assayed serum concentrations CA, CDCA, and 7α-OHC and used linear regression and mixed effects models to test their associations with brain amyloid accumulation (N = 141), WMLs, and brain atrophy (N = 134) in the Baltimore Longitudinal Study of Aging (BLSA). The BLSA is an ongoing, community-based cohort study that began in 1958. Participants in the BLSA neuroimaging sample were approximately 46% male with a mean age of 76 years; longitudinal analyses included an average of 2.5 follow-up magnetic resonance imaging (MRI) visits. We used the Alzheimer's Disease Neuroimaging Initiative (ADNI) (N = 1,666) to validate longitudinal neuroimaging results in BLSA. ADNI is an ongoing, community-based cohort study that began in 2003. Participants were approximately 55% male with a mean age of 74 years; longitudinal analyses included an average of 5.2 follow-up MRI visits. Lower serum concentrations of 7α-OHC, CA, and CDCA were associated with higher brain amyloid deposition (p = 0.041), faster WML accumulation (p = 0.050), and faster brain atrophy mainly (false discovery rate [FDR] p = <0.001-0.013) in males in BLSA. In ADNI, we found a modest sex-specific effect indicating that lower serum concentrations of CA and CDCA were associated with faster brain atrophy (FDR p = 0.049) in males.Step 2: In the Clinical Practice Research Datalink (CPRD) dataset, covering >4 million registrants from general practice clinics in the United Kingdom, we tested whether patients using BAS (BAS users; 3,208 with ≥2 prescriptions), which reduce circulating BAs and increase cholesterol catabolism, had altered dementia risk compared to those on non-statin lipid-modifying therapies (LMT users; 23,483 with ≥2 prescriptions). Patients in the study (BAS/LMT) were approximately 34%/38% male and with a mean age of 65/68 years; follow-up time was 4.7/5.7 years. We found that BAS use was not significantly associated with risk of all-cause dementia (hazard ratio (HR) = 1.03, 95% confidence interval (CI) = 0.72-1.46, p = 0.88) or its subtypes. We found a significant difference between the risk of VaD in males compared to females (p = 0.040) and a significant dose-response relationship between BAS use and risk of VaD (p-trend = 0.045) in males.Step 3: We assayed brain tissue concentrations of CA and CDCA comparing AD and control (CON) samples in the BLSA autopsy cohort (N = 29). Participants in the BLSA autopsy cohort (AD/CON) were approximately 50%/77% male with a mean age of 87/82 years. We analyzed single-cell RNA sequencing (scRNA-Seq) data to compare brain BA receptor gene expression between AD and CON samples from the Religious Orders Study and Memory and Aging Project (ROSMAP) cohort (N = 46). ROSMAP is an ongoing, community-based cohort study that began in 1994. Participants (AD/CON) were approximately 56%/36% male with a mean age of 85/85 years. In BLSA, we found that CA and CDCA were detectable in postmortem brain tissue samples and were marginally higher in AD samples compared to CON. In ROSMAP, we found sex-specific differences in altered neuronal gene expression of BA receptors in AD. Study limitations include the small sample sizes in the BLSA cohort and likely inaccuracies in the clinical diagnosis of dementia subtypes in primary care settings. CONCLUSIONS We combined targeted metabolomics in serum and amyloid positron emission tomography (PET) and MRI of the brain with pharmacoepidemiologic analysis to implicate dysregulation of cholesterol catabolism in dementia pathogenesis. We observed that lower serum BA concentration mainly in males is associated with neuroimaging markers of dementia, and pharmacological lowering of BA levels may be associated with higher risk of VaD in males. We hypothesize that dysregulation of BA signaling pathways in the brain may represent a plausible biologic mechanism underlying these results. Together, our observations suggest a novel mechanism relating abnormalities in cholesterol catabolism to risk of dementia.
Collapse
Affiliation(s)
- Vijay R. Varma
- Clinical and Translational Neuroscience Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, United States of America
| | - Youjin Wang
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Yang An
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, United States of America
| | - Sudhir Varma
- HiThru Analytics, Laurel, Maryland, United States of America
| | - Murat Bilgel
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, United States of America
| | - Jimit Doshi
- Section for Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | | | - João C. Delgado
- College of Medicine and Health, University of Exeter, Exeter, United Kingdom
| | - Anup M. Oommen
- Glycoscience Group, NCBES National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Jackson A. Roberts
- Clinical and Translational Neuroscience Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, United States of America
| | - Dean F. Wong
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Christos Davatzikos
- Section for Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Susan M. Resnick
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, United States of America
| | - Juan C. Troncoso
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Olga Pletnikova
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Richard O’Brien
- Department of Neurology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Eelko Hak
- Groningen Research Institute of Pharmacy, University of Groningen, Groningen, the Netherlands
| | - Brenda N. Baak
- Groningen Research Institute of Pharmacy, University of Groningen, Groningen, the Netherlands
| | - Ruth Pfeiffer
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Priyanka Baloni
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - Siamak Mohmoudiandehkordi
- Department of Psychiatry and Behavioral Sciences, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Kwangsik Nho
- Department of Radiology and Imaging Sciences and the Indiana Alzheimer Disease Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Rima Kaddurah-Daouk
- Department of Psychiatry and Behavioral Sciences, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Shahinaz M. Gadalla
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Madhav Thambisetty
- Clinical and Translational Neuroscience Section, Laboratory of Behavioral Neuroscience, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
18
|
Sesorova IS, Dimov ID, Kashin AD, Sesorov VV, Karelina NR, Zdorikova MA, Beznoussenko GV, Mirоnоv AA. Cellular and sub-cellular mechanisms of lipid transport from gut to lymph. Tissue Cell 2021; 72:101529. [PMID: 33915359 DOI: 10.1016/j.tice.2021.101529] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 02/26/2021] [Accepted: 03/11/2021] [Indexed: 12/14/2022]
Abstract
Although the general structure of the barrier between the gut and the blood is well known, many details are still missing. Here, we analyse the literature and our own data related to lipid transcytosis through adult mammalian enterocytes, and their absorption into lymph at the tissue level of the intestine. After starvation, the Golgi complex (GC) of enterocytes is in a resting state. The addition of lipids in the form of chyme leads to the initial appearance of pre-chylomicrons (ChMs) in the tubules of the smooth endoplasmic reticulum, which are attached at the basolateral plasma membrane, immediately below the 'belt' of the adhesive junctions. Then pre-ChMs move into the cisternae of the rough endoplasmic reticulum and then into the expansion of the perforated Golgi cisternae. Next, they pass through the GC, and are concentrated in the distensions of the perforated cisternae on the trans-side of the GC. The arrival of pre-ChMs at the GC leads to the transition of the GC to a state of active transport, with formation of intercisternal connections, attachment of cis-most and trans-most perforated cisternae to the medial Golgi cisternae, and disappearance of COPI vesicles. Post-Golgi carriers then deliver ChMs to the basolateral plasma membrane, fuse with it, and secret ChMs into the intercellular space between enterocytes at the level of their interdigitating contacts. Finally, ChMs are squeezed out into the interstitium through pores in the basal membrane, most likely due to the function of the actin-myosin 'cuff' around the interdigitating contacts. These pores appear to be formed by protrusions of the dendritic cells and the enterocytes per se. ChMs are absorbed from the interstitium into the lymphatic capillaries through the special oblique contacts between endothelial cells, which function as valves through the contraction-relaxation of bundles of smooth muscle cells in the interstitium. Lipid overloading of enterocytes results in accumulation of cytoplasmic lipid droplets, an increase in diameter of ChMs, inhibition of intra-Golgi transport, and fusion of ChMs in the interstitium. Here, we summarise and analyse recent findings, and discuss their functional implications.
Collapse
Affiliation(s)
- Irina S Sesorova
- Department of Anatomy, Saint Petersburg State Paediatric Medical University, S. Petersburg, Russia
| | - Ivan D Dimov
- Department of Anatomy, Ivanovo State Medical Academy, Ivanovo, Russia
| | - Alexandre D Kashin
- Department of Anatomy, Saint Petersburg State Paediatric Medical University, S. Petersburg, Russia
| | - Vitaly V Sesorov
- Department of Anatomy, Saint Petersburg State Paediatric Medical University, S. Petersburg, Russia
| | | | - Maria A Zdorikova
- Department of Anatomy, Saint Petersburg State Paediatric Medical University, S. Petersburg, Russia
| | | | | |
Collapse
|
19
|
Zhang T, Han X, Zhang X, Chen Z, Mi Y, Gou X. Dietary Fatty Acid Factors in Alzheimer's Disease: A Review. J Alzheimers Dis 2020; 78:887-904. [PMID: 33074226 DOI: 10.3233/jad-200558] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is an irreversible neurodegenerative disease characterized by brain function disorder and chronic cognitive function impairment. The onset of AD is complex and is mostly attributed to interactions between genetic factors and environmental factors. Lifestyle, dietary habits, and food consumption are likely to play indispensable functions in aged-related neurodegenerative diseases in elderly people. An increasing number of epidemiological studies have linked dietary fatty acid factors to AD, raising the point of view that fatty acid metabolism plays an important role in AD initiation and progression as well as in other central nervous system disorders. In this paper, we review the effects of the consumption of various dietary fatty acids on AD onset and progression and discuss the detrimental and beneficial effects of some typical fatty acids derived from dietary patterns on the pathology of AD. We outline these recent advances, and we recommend that healthy dietary lifestyles may contribute to preventing the occurrence and decreasing the pathology of AD.
Collapse
Affiliation(s)
- Tianying Zhang
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, PR China
| | - Xiaojuan Han
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, PR China
| | - Xiaohua Zhang
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, PR China
| | - Zhi Chen
- College of Animal Science and Technology, Yangzhou University, Yangzhou, PR China
| | - Yajing Mi
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, PR China
| | - Xingchun Gou
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, PR China
| |
Collapse
|
20
|
Ardham VR, Zoni V, Adamowicz S, Campomanes P, Vanni S. Accurate Estimation of Membrane Capacitance from Atomistic Molecular Dynamics Simulations of Zwitterionic Lipid Bilayers. J Phys Chem B 2020; 124:8278-8286. [PMID: 32856913 DOI: 10.1021/acs.jpcb.0c03145] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Lipid membranes are indispensable to life, and they regulate countless cellular processes. To investigate the properties of membranes under controlled conditions, numerous reconstitution methods have been developed over the last few decades. Several of these methods result in the formation of lipid bilayers containing residual hydrophobic molecules between the two monolayers. These contaminants might alter membrane properties, including bilayer thickness, that is usually inferred from measurements of membrane capacitance assuming a simple slab model. However, recent measurements on solvent-free bilayers raised significant questions on the reliability of this approach. To reconcile the observed discrepancies, we developed a protocol to predict membrane capacitance from the dielectric profile of lipid bilayers computed from molecular dynamics simulations. Our methodology shows excellent agreement against available data on solvent-free noncharged bilayers, and it confirms that the uniform slab model is a reliable approximation from which to infer membrane capacitance. We find that the effective electrical thickness contributing to membrane capacitance is different from the hydrophobic thickness inferred from X-ray scattering form factors. We apply our model to estimate the concentration of residual solvent in reconstituted systems, and we propose that our protocol could be used to infer membrane properties in the presence of hydrophobic solvents.
Collapse
Affiliation(s)
- Vikram Reddy Ardham
- Chemin du Musée 10, Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Valeria Zoni
- Chemin du Musée 10, Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Sylvain Adamowicz
- Chemin du Musée 10, Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Pablo Campomanes
- Chemin du Musée 10, Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Stefano Vanni
- Chemin du Musée 10, Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| |
Collapse
|
21
|
Jay AG, Simard JR, Huang N, Hamilton JA. SSO and other putative inhibitors of FA transport across membranes by CD36 disrupt intracellular metabolism, but do not affect FA translocation. J Lipid Res 2020; 61:790-807. [PMID: 32102800 DOI: 10.1194/jlr.ra120000648] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/19/2020] [Indexed: 12/19/2022] Open
Abstract
Membrane-bound proteins have been proposed to mediate the transport of long-chain FA (LCFA) transport through the plasma membrane (PM). These proposals are based largely on reports that PM transport of LCFAs can be blocked by a number of enzymes and purported inhibitors of LCFA transport. Here, using the ratiometric pH indicator (2',7'-bis-(2-carboxyethyl)-5-(and-6-)-carboxyfluorescein and acrylodated intestinal FA-binding protein-based dual fluorescence assays, we investigated the effects of nine inhibitors of the putative FA transporter protein CD36 on the binding and transmembrane movement of LCFAs. We particularly focused on sulfosuccinimidyl oleate (SSO), reported to be a competitive inhibitor of CD36-mediated LCFA transport. Using these assays in adipocytes and inhibitor-treated protein-free lipid vesicles, we demonstrate that rapid LCFA transport across model and biological membranes remains unchanged in the presence of these purported inhibitors. We have previously shown in live cells that CD36 does not accelerate the transport of unesterified LCFAs across the PM. Our present experiments indicated disruption of LCFA metabolism inside the cell within minutes upon treatment with many of the "inhibitors" previously assumed to inhibit LCFA transport across the PM. Furthermore, using confocal microscopy and a specific anti-SSO antibody, we found that numerous intracellular and PM-bound proteins are SSO-modified in addition to CD36. Our results support the hypothesis that LCFAs diffuse rapidly across biological membranes and do not require an active protein transporter for their transmembrane movement.
Collapse
Affiliation(s)
- Anthony G Jay
- Department of Physiology and Biomedical Engineering,Mayo Clinic, Rochester, MN 55905; Departments of Biochemistry,Boston University School of Medicine, Boston, MA 02118. mailto:
| | - Jeffrey R Simard
- Physiology and Biophysics,Boston University School of Medicine, Boston, MA 02118; Pharmacology and Experimental Therapeutics,Boston University School of Medicine, Boston, MA 02118
| | - Nasi Huang
- Section of Infectious Diseases Department of Medicine,Boston University School of Medicine, Boston, MA 02118
| | - James A Hamilton
- Physiology and Biophysics,Boston University School of Medicine, Boston, MA 02118
| |
Collapse
|
22
|
Cheng V, Kimball DR, Conboy DJC. Determination of the Rate-Limiting Step in Fatty Acid Transport. J Phys Chem B 2019; 123:7157-7168. [DOI: 10.1021/acs.jpcb.9b05162] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Victoria Cheng
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Dylan R. Kimball
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Dr. John C. Conboy
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| |
Collapse
|
23
|
The Biosynthesis, Signaling, and Neurological Functions of Bile Acids. Biomolecules 2019; 9:biom9060232. [PMID: 31208099 PMCID: PMC6628048 DOI: 10.3390/biom9060232] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 12/13/2022] Open
Abstract
Bile acids (BA) are amphipathic steroid acids synthesized from cholesterol in the liver. They act as detergents to expedite the digestion and absorption of dietary lipids and lipophilic vitamins. BA are also considered to be signaling molecules, being ligands of nuclear and cell-surface receptors, including farnesoid X receptor and Takeda G-protein receptor 5. Moreover, BA also activate ion channels, including the bile acid-sensitive ion channel and epithelial Na+ channel. BA regulate glucose and lipid metabolism by activating these receptors in peripheral tissues, such as the liver and brown and white adipose tissue. Recently, 20 different BA have been identified in the central nervous system. Furthermore, BA affect the function of neurotransmitter receptors, such as the muscarinic acetylcholine receptor and γ-aminobutyric acid receptor. BA are also known to be protective against neurodegeneration. Here, we review recent findings regarding the biosynthesis, signaling, and neurological functions of BA.
Collapse
|
24
|
Škulj S, Vazdar M. Calculation of apparent pK a values of saturated fatty acids with different lengths in DOPC phospholipid bilayers. Phys Chem Chem Phys 2019; 21:10052-10060. [PMID: 31046041 DOI: 10.1039/c9cp01204d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We performed all-atom molecular dynamics simulations and calculated free energy profiles and apparent pKa values for neutral and anionic forms of single myristic (C14:0), palmitic (C16:0) and stearic (C18:0) fatty acid embedded in a DOPC bilayer and explicit water solvent. We showed that the neutral forms of the fatty acids are stabilized inside the bilayer by hydrogen bonding of a fatty acid carboxylic group with DOPC phosphate and carbonyl groups. In contrast to the neutral form, the anionic forms of the fatty acids are shifted towards the water-membrane interface and are instead stabilized by hydrogen bonding to interfacial water. By using umbrella sampling simulations, we calculated free energies of stabilization and revealed that the free energy of stabilization inside the bilayer increases with the chain length for both the neutral and deprotonated forms. On the other hand, the free energies of flip-flop of both the neutral and anionic forms are constant upon the prolongation of the fatty acid. Based on the free energy curves, we also calculated apparent fatty acid pKa,app values in the bilayer, which are 7.0, 7.2 and 6.3 for myristic, palmitic and stearic acid and are increased by several pKa units compared to the corresponding pKa values in water. By further analysis of the calculated curves we found that spontaneous protonation of fatty acid anions takes place in the bilayer interior at ca. 1.4 nm from the bilayer center for all studied fatty acids.
Collapse
Affiliation(s)
- Sanja Škulj
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb, Croatia.
| | | |
Collapse
|
25
|
Ogunbona OB, Claypool SM. Emerging Roles in the Biogenesis of Cytochrome c Oxidase for Members of the Mitochondrial Carrier Family. Front Cell Dev Biol 2019; 7:3. [PMID: 30766870 PMCID: PMC6365663 DOI: 10.3389/fcell.2019.00003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 01/10/2019] [Indexed: 12/11/2022] Open
Abstract
The mitochondrial carrier family (MCF) is a group of transport proteins that are mostly localized to the inner mitochondrial membrane where they facilitate the movement of various solutes across the membrane. Although these carriers represent potential targets for therapeutic application and are repeatedly associated with human disease, research on the MCF has not progressed commensurate to their physiologic and pathophysiologic importance. Many of the 53 MCF members in humans are orphans and lack known transport substrates. Even for the relatively well-studied members of this family, such as the ADP/ATP carrier and the uncoupling protein, there exist fundamental gaps in our understanding of their biological roles including a clear rationale for the existence of multiple isoforms. Here, we briefly review this important family of mitochondrial carriers, provide a few salient examples of their diverse metabolic roles and disease associations, and then focus on an emerging link between several distinct MCF members, including the ADP/ATP carrier, and cytochrome c oxidase biogenesis. As the ADP/ATP carrier is regarded as the paradigm of the entire MCF, its newly established role in regulating translation of the mitochondrial genome highlights that we still have a lot to learn about these metabolite transporters.
Collapse
Affiliation(s)
- Oluwaseun B. Ogunbona
- Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
- Department of Pathology & Laboratory Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - Steven M. Claypool
- Department of Physiology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| |
Collapse
|
26
|
Jay AG, Hamilton JA. The enigmatic membrane fatty acid transporter CD36: New insights into fatty acid binding and their effects on uptake of oxidized LDL. Prostaglandins Leukot Essent Fatty Acids 2018; 138:64-70. [PMID: 27288302 DOI: 10.1016/j.plefa.2016.05.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/11/2016] [Indexed: 12/15/2022]
Abstract
The scavenger receptor CD36 binds numerous small biomolecules, including fatty acids, and even large ligands such as oxidized LDL, for which it is considered a receptor. Although CD36 has often been postulated to "transport" fatty acids across the plasma membrane, fatty acids translocation (mass transport or kinetics) was not affected by expression of CD36 in HEK293 cells; however, esterification of fatty acids (cellular uptake) was increased. These recent results from our lab are consistent with the established mechanism of fatty acid entry into cells by passive diffusion (flip-flop) and also with the well-documented enhancement of uptake of fatty acids by CD36 in other cell types. A fascinating new discovery is that CD36 has multiple fatty acid binding sites on the extracellular domain of CD36. As illuminated by new methodologies that we have applied, these sites have high affinity and exhibit rapid exchange with the medium. In an initial study of functional consequences of binding, several dietary fatty acids enhanced uptake of oxidized LDL into HEK293 cells expressing CD36. This is the first established link between physical binding of fatty acids and a function of CD36, and has implications for obesity and atherosclerosis. New methods as those used in our study could also be applied to elucidate other functional roles of fatty acid binding to CD36.
Collapse
Affiliation(s)
- Anthony G Jay
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, United States; Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, United States
| | - James A Hamilton
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, United States.
| |
Collapse
|
27
|
Allen AC, Romero-Mangado J, Adams S, Flynn M, Chen B, Zhang JZ. Detection of Saturated Fatty Acids Associated with a Self-Healing Synthetic Biological Membrane Using Fiber-Enhanced Surface Enhanced Raman Scattering. J Phys Chem B 2018; 122:8396-8403. [PMID: 30137989 DOI: 10.1021/acs.jpcb.8b06994] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Synthetic Biological Membrane (SBM) project at NASA Ames developed a portable, self-repairing wastewater purification system. The self-repair process relies upon secreted fatty acids from a genetically engineered organism. However, solubilized fatty acids are difficult to detect using conventional methods. Surface-enhanced Raman scattering (SERS) was used to successfully detect solubilized fatty acids with the following limits of detection: 10-9, 10-8, 10-9, and 10-6 M for decanoic acid, myristic acid, palmitic acid, and stearic acid, respectively. Additionally, hollow core photonic crystal fiber (HCPCF) was applied as the sampling device together with SERS to develop in situ surveillance of the production of fatty acids. Using SERS + HCPCF yielded an 18-fold enhancement in SERS signal for the CH2 twist peak at 1295 cm-1 as compared to SERS alone. The results will help the SBM project to integrate a self-healing wastewater purification membrane into future water recycling systems.
Collapse
Affiliation(s)
- A'Lester C Allen
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Jaione Romero-Mangado
- NASA Ames Research Center , Moffett Field, Mountain View , California 94035 , United States.,Science & Technology Corporation , NASA Ames Research Park , Moffett Field, Mountain View , California 94035 , United States
| | - Staci Adams
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Michael Flynn
- NASA Ames Research Center , Moffett Field, Mountain View , California 94035 , United States
| | - Bin Chen
- NASA Ames Research Center , Moffett Field, Mountain View , California 94035 , United States
| | - Jin Z Zhang
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| |
Collapse
|
28
|
Ježek P, Holendová B, Garlid KD, Jabůrek M. Mitochondrial Uncoupling Proteins: Subtle Regulators of Cellular Redox Signaling. Antioxid Redox Signal 2018; 29:667-714. [PMID: 29351723 PMCID: PMC6071544 DOI: 10.1089/ars.2017.7225] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
SIGNIFICANCE Mitochondria are the energetic, metabolic, redox, and information signaling centers of the cell. Substrate pressure, mitochondrial network dynamics, and cristae morphology state are integrated by the protonmotive force Δp or its potential component, ΔΨ, which are attenuated by proton backflux into the matrix, termed uncoupling. The mitochondrial uncoupling proteins (UCP1-5) play an eminent role in the regulation of each of the mentioned aspects, being involved in numerous physiological events including redox signaling. Recent Advances: UCP2 structure, including purine nucleotide and fatty acid (FA) binding sites, strongly support the FA cycling mechanism: UCP2 expels FA anions, whereas uncoupling is achieved by the membrane backflux of protonated FA. Nascent FAs, cleaved by phospholipases, are preferential. The resulting Δp dissipation decreases superoxide formation dependent on Δp. UCP-mediated antioxidant protection and its impairment are expected to play a major role in cell physiology and pathology. Moreover, UCP2-mediated aspartate, oxaloacetate, and malate antiport with phosphate is expected to alter metabolism of cancer cells. CRITICAL ISSUES A wide range of UCP antioxidant effects and participations in redox signaling have been reported; however, mechanisms of UCP activation are still debated. Switching off/on the UCP2 protonophoretic function might serve as redox signaling either by employing/releasing the extra capacity of cell antioxidant systems or by directly increasing/decreasing mitochondrial superoxide sources. Rapid UCP2 degradation, FA levels, elevation of purine nucleotides, decreased Mg2+, or increased pyruvate accumulation may initiate UCP-mediated redox signaling. FUTURE DIRECTIONS Issues such as UCP2 participation in glucose sensing, neuronal (synaptic) function, and immune cell activation should be elucidated. Antioxid. Redox Signal. 29, 667-714.
Collapse
Affiliation(s)
- Petr Ježek
- 1 Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences , Prague, Czech Republic
| | - Blanka Holendová
- 1 Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences , Prague, Czech Republic
| | - Keith D Garlid
- 2 UCLA Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA , Los Angeles, California
| | - Martin Jabůrek
- 1 Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences , Prague, Czech Republic
| |
Collapse
|
29
|
Li J, Dawson PA. Animal models to study bile acid metabolism. Biochim Biophys Acta Mol Basis Dis 2018; 1865:895-911. [PMID: 29782919 DOI: 10.1016/j.bbadis.2018.05.011] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 12/19/2022]
Abstract
The use of animal models, particularly genetically modified mice, continues to play a critical role in studying the relationship between bile acid metabolism and human liver disease. Over the past 20 years, these studies have been instrumental in elucidating the major pathways responsible for bile acid biosynthesis and enterohepatic cycling, and the molecular mechanisms regulating those pathways. This work also revealed bile acid differences between species, particularly in the composition, physicochemical properties, and signaling potential of the bile acid pool. These species differences may limit the ability to translate findings regarding bile acid-related disease processes from mice to humans. In this review, we focus primarily on mouse models and also briefly discuss dietary or surgical models commonly used to study the basic mechanisms underlying bile acid metabolism. Important phenotypic species differences in bile acid metabolism between mice and humans are highlighted.
Collapse
Affiliation(s)
- Jianing Li
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, Emory University, Atlanta, GA 30322, United States
| | - Paul A Dawson
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, Emory University, Atlanta, GA 30322, United States.
| |
Collapse
|
30
|
Mertens KL, Kalsbeek A, Soeters MR, Eggink HM. Bile Acid Signaling Pathways from the Enterohepatic Circulation to the Central Nervous System. Front Neurosci 2017; 11:617. [PMID: 29163019 PMCID: PMC5681992 DOI: 10.3389/fnins.2017.00617] [Citation(s) in RCA: 170] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/23/2017] [Indexed: 12/14/2022] Open
Abstract
Bile acids are best known as detergents involved in the digestion of lipids. In addition, new data in the last decade have shown that bile acids also function as gut hormones capable of influencing metabolic processes via receptors such as FXR (farnesoid X receptor) and TGR5 (Takeda G protein-coupled receptor 5). These effects of bile acids are not restricted to the gastrointestinal tract, but can affect different tissues throughout the organism. It is still unclear whether these effects also involve signaling of bile acids to the central nervous system (CNS). Bile acid signaling to the CNS encompasses both direct and indirect pathways. Bile acids can act directly in the brain via central FXR and TGR5 signaling. In addition, there are two indirect pathways that involve intermediate agents released upon interaction with bile acids receptors in the gut. Activation of intestinal FXR and TGR5 receptors can result in the release of fibroblast growth factor 19 (FGF19) and glucagon-like peptide 1 (GLP-1), both capable of signaling to the CNS. We conclude that when plasma bile acids levels are high all three pathways may contribute in signal transmission to the CNS. However, under normal physiological circumstances, the indirect pathway involving GLP-1 may evoke the most substantial effect in the brain.
Collapse
Affiliation(s)
- Kim L Mertens
- Master's Program in Biomedical Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Andries Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Laboratory of Endocrinology, Department Clinical Chemistry, Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands.,Department of Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, Netherlands
| | - Maarten R Soeters
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Hannah M Eggink
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Department of Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, Netherlands
| |
Collapse
|
31
|
Sannasiddappa TH, Lund PA, Clarke SR. In Vitro Antibacterial Activity of Unconjugated and Conjugated Bile Salts on Staphylococcus aureus. Front Microbiol 2017; 8:1581. [PMID: 28878747 PMCID: PMC5572772 DOI: 10.3389/fmicb.2017.01581] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/03/2017] [Indexed: 12/12/2022] Open
Abstract
Bile salts are potent antimicrobial agents and are an important component of innate defenses in the intestine, giving protection against invasive organisms. They play an important role in determining microbial ecology of the intestine and alterations in their levels can lead to increased colonization by pathogens. We have previously demonstrated survival of the opportunistic pathogen Staphylococcus aureus in the human colonic model. Thus investigating the interaction between S. aureus and bile salts is an important factor in understanding its ability to colonize in the host intestine. Harnessing bile salts may also give a new avenue to explore in the development of therapeutic strategies to control drug resistant bacteria. Despite this importance, the antibacterial activity of bile salts on S. aureus is poorly understood. In this study, we investigated the antibacterial effects of the major unconjugated and conjugated bile salts on S. aureus. Several concentration-dependent antibacterial mechanisms were found. Unconjugated bile salts at their minimum inhibitory concentration (cholic and deoxycholic acid at 20 and 1 mM, respectively) killed S. aureus, and this was associated with increased membrane disruption and leakage of cellular contents. Unconjugated bile salts (cholic and deoxycholic acid at 8 and 0.4 mM, respectively) and conjugated bile salts (glycocholic and taurocholic acid at 20 mM) at their sub inhibitory concentrations were still able to inhibit growth through disruption of the proton motive force and increased membrane permeability. We also demonstrated that unconjugated bile salts possess more potent antibacterial action on S. aureus than conjugated bile salts.
Collapse
Affiliation(s)
| | - Peter A Lund
- Institute of Microbiology and Infection, School of Biosciences, University of BirminghamBirmingham, United Kingdom
| | - Simon R Clarke
- School of Biological Sciences, University of ReadingReading, United Kingdom
| |
Collapse
|
32
|
Watanabe M, Fukiya S, Yokota A. Comprehensive evaluation of the bactericidal activities of free bile acids in the large intestine of humans and rodents. J Lipid Res 2017; 58:1143-1152. [PMID: 28404640 DOI: 10.1194/jlr.m075143] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/03/2017] [Indexed: 01/01/2023] Open
Abstract
In addition to functioning as detergents that aid digestion of dietary lipids in the intestine, some bile acids have been shown to exhibit antimicrobial activity. However, detailed information on the bactericidal activities of the diverse molecular species of bile acid in humans and rodents is largely unknown. Here, we investigated the toxicity of 14 typical human and rodent free bile acids (FBAs) by monitoring intracellular pH, membrane integrity, and viability of a human intestinal bacterium, Bifidobacterium breve Japan Collection of Microorganisms (JCM) 1192T, upon exposure to these FBAs. Of all FBAs evaluated, deoxycholic acid (DCA) and chenodeoxycholic acid displayed the highest toxicities. Nine FBAs common to humans and rodents demonstrated that α-hydroxy-type bile acids are more toxic than their oxo-derivatives and β-hydroxy-type epimers. In five rodent-specific FBAs, β-muricholic acid and hyodeoxycholic acid showed comparable toxicities at a level close to DCA. Similar trends were observed for the membrane-damaging effects and bactericidal activities to Blautia coccoides JCM 1395T and Bacteroides thetaiotaomicron DSM 2079T, commonly represented in the human and rodent gut microbiota. These findings will help us to determine the fundamental properties of FBAs and better understand the role of FBAs in the regulation of gut microbiota composition.
Collapse
Affiliation(s)
- Masamichi Watanabe
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan
| | - Satoru Fukiya
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan
| | - Atsushi Yokota
- Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan
| |
Collapse
|
33
|
Wellen BA, Lach EA, Allen HC. Surface pKa of octanoic, nonanoic, and decanoic fatty acids at the air–water interface: applications to atmospheric aerosol chemistry. Phys Chem Chem Phys 2017; 19:26551-26558. [DOI: 10.1039/c7cp04527a] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Surface-pKa of medium-chain fatty acids, determined by surface tension titration, is different from the bulk value.
Collapse
Affiliation(s)
- Bethany A. Wellen
- Department of Chemistry & Biochemistry
- The Ohio State University
- Columbus
- Ohio 43210
- USA
| | - Evan A. Lach
- Department of Chemistry & Biochemistry
- The Ohio State University
- Columbus
- Ohio 43210
- USA
| | - Heather C. Allen
- Department of Chemistry & Biochemistry
- The Ohio State University
- Columbus
- Ohio 43210
- USA
| |
Collapse
|
34
|
Calcium Enhances Bile Salt-Dependent Virulence Activation in Vibrio cholerae. Infect Immun 2016; 85:IAI.00707-16. [PMID: 27849180 DOI: 10.1128/iai.00707-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/04/2016] [Indexed: 12/17/2022] Open
Abstract
Vibrio cholerae is the causative bacteria of the diarrheal disease cholera, but it also persists in aquatic environments, where it displays an expression profile that is distinct from that during infection. Upon entry into the host, a tightly regulated circuit coordinates the induction of two major virulence factors: cholera toxin and a toxin-coregulated pilus (TCP). It has been shown that a set of bile salts, including taurocholate, serve as host signals to activate V. cholerae virulence through inducing the activity of the transmembrane virulence regulator TcpP. In this study, we investigated the role of calcium, an abundant mental ion in the gut, in the regulation of virulence. We show that whereas Ca2+ alone does not affect virulence, Ca2+ enhances bile salt-dependent virulence activation for V. cholerae The induction of TCP by murine intestinal contents is counteracted when Ca2+ is depleted by the high-affinity calcium chelator EGTA, suggesting that the calcium present in the gut is a relevant signal for V. cholerae virulence induction in vivo We further show that Ca2+ enhances virulence by promoting bile salt-induced TcpP-TcpP interaction. Moreover, fluorescence recovery after photobleaching (FRAP) analysis demonstrated that exposure to bile salts and Ca2+ together decreases the recovery rate for fluorescently labeled TcpP, but not for another inner membrane protein (TatA). Together, these data support a model in which physiological levels of Ca2+ may result in altered bile salt-induced TcpP protein movement and activity, ultimately leading to an increased expression of virulence.
Collapse
|
35
|
A Review of the Evidence Supporting the Taste of Non‐esterified Fatty Acids in Humans. J AM OIL CHEM SOC 2016. [DOI: 10.1007/s11746-016-2885-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
36
|
Cansev M. Synaptogenesis: Modulation by Availability of Membrane Phospholipid Precursors. Neuromolecular Med 2016; 18:426-40. [DOI: 10.1007/s12017-016-8414-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 05/24/2016] [Indexed: 10/21/2022]
|
37
|
Hay AJ, Zhu J. In Sickness and in Health: The Relationships Between Bacteria and Bile in the Human Gut. ADVANCES IN APPLIED MICROBIOLOGY 2016; 96:43-64. [PMID: 27565580 DOI: 10.1016/bs.aambs.2016.07.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Colonization of a human host with a commensal microbiota has a complex interaction in which bacterial communities provide numerous health benefits to the host. An equilibrium between host and microbiota is kept in check with the help of biliary secretions by the host. Bile, composed primarily of bile salts, promotes digestion. It also provides a barrier between host and bacteria. After bile salts are synthesized in the liver, they are stored in the gallbladder to be released after food intake. The set of host-secreted bile salts is modified by the resident bacteria. Because bile salts are toxic to bacteria, an equilibrium of modified bile salts is reached that allows commensal bacteria to survive, yet rebuffs invading pathogens. In addition to direct toxic effects on cells, bile salts maintain homeostasis as signaling molecules, tuning the immune system. To cause disease, gram-negative pathogenic bacteria have shared strategies to survive this harsh environment. Through exclusion of bile, efflux of bile, and repair of bile-induced damage, these pathogens can successfully disrupt and outcompete the microbiota to activate virulence factors.
Collapse
Affiliation(s)
- A J Hay
- University of Pennsylvania, Philadelphia, PA, United States
| | - J Zhu
- University of Pennsylvania, Philadelphia, PA, United States
| |
Collapse
|
38
|
Zhou X, Zeitz JO, Meile L, Kreuzer M, Schwarm A. Influence of pH and the degree of protonation on the inhibitory effect of fatty acids in the ruminal methanogen Methanobrevibacter ruminantium strain M1. J Appl Microbiol 2015; 119:1482-93. [PMID: 26394014 DOI: 10.1111/jam.12955] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 09/09/2015] [Accepted: 09/11/2015] [Indexed: 11/30/2022]
Abstract
AIMS To investigate the relationship between the protonation of medium-chain fatty acids (MCFA) and their inhibitory effect on a ruminal methanogen species. METHODS AND RESULTS Cell suspensions of Methanobrevibacter ruminantium M1 in 1 mg dry matter (DM) ml(-1) were supplemented with lauric acid (C12 ) and myristic acid (C14 ) at a concentration of 8 μg ml(-1) with different pH levels of the potassium-free buffer, where the calculated degrees of protonation of C12 and C14 varied from 0·3 to 50% and from 1 to 76% respectively. Methane formation, ATP efflux, potassium leakage and cell viability were monitored 15, 30 and 45 min after the reaction started. Declining methane formation rate, increasing ATP efflux and potassium leakage, and decreasing survival of M. ruminantium were observed with increasing degrees of protonation, i.e. with decreasing pH. CONCLUSIONS The inhibition of methanogenesis by C12 and C14 is more efficient at a pH of 5-6 as compared to pH 7. SIGNIFICANCE AND IMPACT OF THE STUDY Methane mitigation strategies in ruminants which use supplementation of feed with MCFA such as C12 and C14 may be more effective in a low rumen pH environment. This finding is helpful in designing diets to effectively decrease methane emissions by ruminants.
Collapse
Affiliation(s)
- X Zhou
- ETH Zurich, Institute of Agricultural Sciences, Zurich, Switzerland
| | - J O Zeitz
- ETH Zurich, Institute of Agricultural Sciences, Zurich, Switzerland.,Justus Liebig University Giessen, Institute of Animal Nutrition and Nutritional Physiology, Giessen, Germany
| | - L Meile
- ETH Zurich, Institute of Food, Nutrition and Health, Zurich, Switzerland
| | - M Kreuzer
- ETH Zurich, Institute of Agricultural Sciences, Zurich, Switzerland
| | - A Schwarm
- ETH Zurich, Institute of Agricultural Sciences, Zurich, Switzerland
| |
Collapse
|
39
|
Kamat NP, Tobé S, Hill IT, Szostak JW. Electrostatic Localization of RNA to Protocell Membranes by Cationic Hydrophobic Peptides. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505742] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
40
|
Kamat NP, Tobé S, Hill IT, Szostak JW. Electrostatic Localization of RNA to Protocell Membranes by Cationic Hydrophobic Peptides. Angew Chem Int Ed Engl 2015. [PMID: 26223820 PMCID: PMC4600236 DOI: 10.1002/anie.201505742] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cooperative interactions between RNA and vesicle membranes on the prebiotic earth may have led to the emergence of primitive cells. The membrane surface offers a potential platform for the catalysis of reactions involving RNA, but this scenario relies upon the existence of a simple mechanism by which RNA could become associated with protocell membranes. Here, we show that electrostatic interactions provided by short, basic, amphipathic peptides can be harnessed to drive RNA binding to both zwitterionic phospholipid and anionic fatty acid membranes. We show that the association of cationic molecules with phospholipid vesicles can enhance the local positive charge on a membrane and attract RNA polynucleotides. This phenomenon can be reproduced with amphipathic peptides as short as three amino acids. Finally, we show that peptides can cross bilayer membranes to localize encapsulated RNA. This mechanism of polynucleotide confinement could have been important for primitive cellular evolution.
Collapse
Affiliation(s)
- Neha P Kamat
- Department of Molecular Biology, Howard Hughes Medical Institute and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114 (USA)
| | - Sylvia Tobé
- Department of Molecular Biology, Howard Hughes Medical Institute and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114 (USA).,Ra Pharmaceuticals, Cambridge, MA 02139 (USA)
| | - Ian T Hill
- Department of Molecular Biology, Howard Hughes Medical Institute and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114 (USA).,Massachusetts General Hospital Cancer Center and Department of Medicine, Harvard Medical School, Charlestown, MA 02129 (USA)
| | - Jack W Szostak
- Department of Molecular Biology, Howard Hughes Medical Institute and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA 02114 (USA).
| |
Collapse
|
41
|
Belov GA. Modulation of lipid synthesis and trafficking pathways by picornaviruses. Curr Opin Virol 2014; 9:19-23. [PMID: 25240228 DOI: 10.1016/j.coviro.2014.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 08/28/2014] [Indexed: 01/28/2023]
Abstract
Picornaviruses include rapidly replicating viruses that may complete their infectious cycle within a few hours. During this short time the massive development of viral replication organelles completely transforms the cellular membrane landscape. The origin of these structures and mechanism(s) underlying their rapid expansion are still poorly understood. Recent studies revealed profound reorganization of synthesis and distribution of major structural lipids in infected cells. These data show that the lipid composition of the replication organelles is significantly different from that of preexisting cellular membranes. The apparently universal activation of specific lipid syntheses by diverse picornaviruses and at least some other (+)RNA viruses suggests that the mechanism(s) of replication organelle development may be conserved among distantly related viruses.
Collapse
Affiliation(s)
- George A Belov
- Department of Veterinary Medicine, University of Maryland, and Virginia-Maryland Regional College of Veterinary Medicine, College Park, MD 20742, United States.
| |
Collapse
|
42
|
Dawson PA, Karpen SJ. Intestinal transport and metabolism of bile acids. J Lipid Res 2014; 56:1085-99. [PMID: 25210150 DOI: 10.1194/jlr.r054114] [Citation(s) in RCA: 329] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Indexed: 12/17/2022] Open
Abstract
In addition to their classical roles as detergents to aid in the process of digestion, bile acids have been identified as important signaling molecules that function through various nuclear and G protein-coupled receptors to regulate a myriad of cellular and molecular functions across both metabolic and nonmetabolic pathways. Signaling via these pathways will vary depending on the tissue and the concentration and chemical structure of the bile acid species. Important determinants of the size and composition of the bile acid pool are their efficient enterohepatic recirculation, their host and microbial metabolism, and the homeostatic feedback mechanisms connecting hepatocytes, enterocytes, and the luminal microbiota. This review focuses on the mammalian intestine, discussing the physiology of bile acid transport, the metabolism of bile acids in the gut, and new developments in our understanding of how intestinal metabolism, particularly by the gut microbiota, affects bile acid signaling.
Collapse
Affiliation(s)
- Paul A Dawson
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, Emory University, Atlanta, GA 30322
| | - Saul J Karpen
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, Emory University, Atlanta, GA 30322
| |
Collapse
|
43
|
Yang L, Feng F, Fawcett JP, Tucker IG. Kinetic and equilibrium studies of bile salt-liposome interactions. J Liposome Res 2014; 25:58-66. [PMID: 24960448 DOI: 10.3109/08982104.2014.928888] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Research has suggested that exposure to sub-micellar concentrations of bile salts (BS) increases the permeability of lipid bilayers in a time-dependent manner. In this study, incubation of soy phosphatidylcholine small unilamellar vesicles (liposomes) with sub-micellar concentrations of cholate (C), deoxycholate (DC), 12-monoketocholate (MKC) or taurocholate (TC) in pH 7.2 buffer increased membrane fluidity and negative zeta potential in the order of increasing BS liposome-pH 7.2 buffer distribution coefficients (MKC < C ≈ TC < DC). In liposomes labeled with the dithionite-sensitive fluorescent lipid N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine (NBD-PE) in both leaflets and equilibrated with sub-micellar concentrations of BS, fluorescence decline during continuous exposure to dithionite was biphasic involving a rapid initial phase followed by a slower second phase. Membrane permeability to dithionite as measured by the rate of the second phase increased in the order control < MKC < TC ∼ C < DC. In liposomes labeled with NBD-PE in the inner leaflet only and incubated with the same concentrations of C, DC and MKC, membrane permeability to dithionite initially increased very rapidly in the order MKC < C < DC before impermeability to dithionite was restored after which fluorescence decline was consistent with NBD-PE flip-flop. For liposomes incubated with TC, membrane permeability to dithionite was only slightly increased and the decline in fluorescence was mainly the result of NBD-PE flip-flop. These results provide evidence that BS interact with lipid bilayers in a time-dependent manner that is different for conjugated and unconjugated BS. MKC appears to cause least disturbance to liposomal membranes but, when the actual MKC concentration in liposomes is taken into account, MKC is actually the most disruptive.
Collapse
Affiliation(s)
- Lin Yang
- School of Pharmacy, University of Otago , Dunedin , New Zealand
| | | | | | | |
Collapse
|
44
|
Abstract
Viruses are obligatory intracellular parasites and utilize host elements to support key viral processes, including penetration of the plasma membrane, initiation of infection, replication, and suppression of the host's antiviral defenses. In this review, we focus on picornaviruses, a family of positive-strand RNA viruses, and discuss the mechanisms by which these viruses hijack the cellular machinery to form and operate membranous replication complexes. Studies aimed at revealing factors required for the establishment of viral replication structures identified several cellular-membrane-remodeling proteins and led to the development of models in which the virus used a preexisting cellular-membrane-shaping pathway "as is" for generating its replication organelles. However, as more data accumulate, this view is being increasingly questioned, and it is becoming clearer that viruses may utilize cellular factors in ways that are distinct from the normal functions of these proteins in uninfected cells. In addition, the proteincentric view is being supplemented by important new studies showing a previously unappreciated deep remodeling of lipid homeostasis, including extreme changes to phospholipid biosynthesis and cholesterol trafficking. The data on viral modifications of lipid biosynthetic pathways are still rudimentary, but it appears once again that the viruses may rewire existing pathways to generate novel functions. Despite remarkable progress, our understanding of how a handful of viral proteins can completely overrun the multilayered, complex mechanisms that control the membrane organization of a eukaryotic cell remains very limited.
Collapse
|
45
|
Tucker RM, Mattes RD, Running CA. Mechanisms and effects of "fat taste" in humans. Biofactors 2014; 40:313-26. [PMID: 24591077 DOI: 10.1002/biof.1162] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 02/18/2014] [Indexed: 12/11/2022]
Abstract
Evidence supporting a "taste" cue from fat in the oral cavity continues to accrue. The proposed stimuli for fat taste, non-esterified fatty acids (NEFA), are released from food through hydrolytic rancidity and lipase activity derived from foods or saliva. NEFA must then be released from the food matrix, negotiate the aqueous environment to reach taste cell surfaces, and interact with receptors such as CD36 and GPR120 or diffuse across cell membranes to initiate a taste signal. Knowledge of these processes in non-gustatory tissues should inform understanding of taste responses to NEFA. Additionally, downstream effects of oral triglyceride exposure have been observed in numerous studies. Data specific to effects of NEFA versus triglyceride are scarce, but modified sham feeding trials with triglyceride document cephalic phase responses including elevations in serum lipids and insulin as well as potential, but debated, effects on gut peptides, appetite, and thermogenesis. In this review, we highlight the mechanisms by which NEFA migrate to and interact with taste cells, and then we examine physiological responses to oral fat exposure.
Collapse
Affiliation(s)
- Robin M Tucker
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | | | | |
Collapse
|
46
|
Paul S, Alegre KO, Holdsworth SR, Rice M, Brown JA, McVeigh P, Kelly SM, Law CJ. A single-component multidrug transporter of the major facilitator superfamily is part of a network that protects Escherichia coli from bile salt stress. Mol Microbiol 2014; 92:872-84. [PMID: 24684269 PMCID: PMC4235344 DOI: 10.1111/mmi.12597] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2014] [Indexed: 01/16/2023]
Abstract
Resistance to high concentrations of bile salts in the human intestinal tract is vital for the survival of enteric bacteria such as Escherichia coli. Although the tripartite AcrAB-TolC efflux system plays a significant role in this resistance, it is purported that other efflux pumps must also be involved. We provide evidence from a comprehensive suite of experiments performed at two different pH values (7.2 and 6.0) that reflect pH conditions that E. coli may encounter in human gut that MdtM, a single-component multidrug resistance transporter of the major facilitator superfamily, functions in bile salt resistance in E. coli by catalysing secondary active transport of bile salts out of the cell cytoplasm. Furthermore, assays performed on a chromosomal ΔacrB mutant transformed with multicopy plasmid encoding MdtM suggested a functional synergism between the single-component MdtM transporter and the tripartite AcrAB-TolC system that results in a multiplicative effect on resistance. Substrate binding experiments performed on purified MdtM demonstrated that the transporter binds to cholate and deoxycholate with micromolar affinity, and transport assays performed on inverted vesicles confirmed the capacity of MdtM to catalyse electrogenic bile salt/H(+) antiport.
Collapse
Affiliation(s)
- Stephanie Paul
- Institute for Global Food Security, School of Biological Sciences, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Singh J, Lai AJ, Alaee Y, Ranganathan R. Partitioning of lysolipids, fatty acids and their mixtures in aqueous lipid bilayers: solute concentration/composition effects. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:348-54. [PMID: 24099742 DOI: 10.1016/j.bbamem.2013.09.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 09/14/2013] [Accepted: 09/25/2013] [Indexed: 11/19/2022]
Abstract
Distributions of lysopalmitoylphosphatidylcholine (LPPC), palmitic acid (PA) and their 1:1 mixtures between water and dipalmitoylphosphatidylcholine (DPPC) bilayer were determined using a fluorescence probe that selectively detects only the solutes in water. Water solute concentrations were obtained at each of several lipid concentrations. Dynamic Light Scattering experiments confirmed that the lipid/solute aggregates were vesicles in the concentration range investigated. Lipid concentration dependence of the solute component in water was fit to a thermodynamic model of solute distribution between two coexisting solvents. Water/bilayer partition coefficient and the free energy of transfer, for each of these solutes were determined from the fit. Main findings are: (1) Water/bilayer partition coefficient of solute is greater for 2 to 10% solute mole fraction than for 0 to 2%, signaling solute induced bilayer perturbation that increases bilayer solubility, beginning at 2% solute mole fraction. (2) Partition coefficients are in the order LPPC<PA<LPPC+PA at 37°C and LPPC+PA≤LPPC<PA at 50°C. This signifies synergism toward increased solute solubility in the bilayer-gel phase and lack of it in the bilayer-liquid phase when LPPC and PA are present together. Implications of the solute concentration/composition and bilayer phase dependences of the partition coefficients to the reported solute induced enhancements in transmembrane permeability are discussed.
Collapse
Affiliation(s)
- Jasmeet Singh
- Department of Physics and the Center for Supramolecular Studies, California State University Northridge, CA 91330-8268, USA
| | | | | | | |
Collapse
|
48
|
Xu S, Jay A, Brunaldi K, Huang N, Hamilton JA. CD36 Enhances Fatty Acid Uptake by Increasing the Rate of Intracellular Esterification but Not Transport across the Plasma Membrane. Biochemistry 2013; 52:7254-61. [DOI: 10.1021/bi400914c] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Su Xu
- Department
of Physiology and Biophysics, Boston University, 700 Albany Street, Boston, Massachusetts 02118, United States
| | - Anthony Jay
- Department
of Physiology and Biophysics, Boston University, 700 Albany Street, Boston, Massachusetts 02118, United States
| | - Kellen Brunaldi
- Department
of Physiology and Biophysics, Boston University, 700 Albany Street, Boston, Massachusetts 02118, United States
| | - Nasi Huang
- Department
of Physiology and Biophysics, Boston University, 700 Albany Street, Boston, Massachusetts 02118, United States
| | - James A. Hamilton
- Department
of Physiology and Biophysics, Boston University, 700 Albany Street, Boston, Massachusetts 02118, United States
| |
Collapse
|
49
|
Samartsev VN, Rybakova SR, Dubinin MV. Interaction of free fatty acids with mitochondria during uncoupling of oxidative phosphorylation. Biophysics (Nagoya-shi) 2013. [DOI: 10.1134/s0006350913030147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
50
|
O'Byrne SM, Blaner WS. Retinol and retinyl esters: biochemistry and physiology. J Lipid Res 2013; 54:1731-43. [PMID: 23625372 PMCID: PMC3679378 DOI: 10.1194/jlr.r037648] [Citation(s) in RCA: 220] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 04/24/2013] [Indexed: 12/23/2022] Open
Abstract
By definition, a vitamin is a substance that must be obtained regularly from the diet. Vitamin A must be acquired from the diet, but unlike most vitamins, it can also be stored within the body in relatively high levels. For humans living in developed nations or animals living in present-day vivariums, stored vitamin A concentrations can become relatively high, reaching levels that can protect against the adverse effects of insufficient vitamin A dietary intake for six months, or even much longer. The ability to accumulate vitamin A stores lessens the need for routinely consuming vitamin A in the diet, and this provides a selective advantage to the organism. The molecular processes that underlie this selective advantage include efficient mechanisms to acquire vitamin A from the diet, efficient and overlapping mechanisms for the transport of vitamin A in the circulation, a specific mechanism allowing for vitamin A storage, and a mechanism for mobilizing vitamin A from these stores in response to tissue needs. These processes are considered in this review.
Collapse
Affiliation(s)
- Sheila M. O'Byrne
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - William S. Blaner
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| |
Collapse
|