1
|
Alves LDF, Moore JB, Kell DB. The Biology and Biochemistry of Kynurenic Acid, a Potential Nutraceutical with Multiple Biological Effects. Int J Mol Sci 2024; 25:9082. [PMID: 39201768 PMCID: PMC11354673 DOI: 10.3390/ijms25169082] [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: 07/19/2024] [Revised: 08/16/2024] [Accepted: 08/19/2024] [Indexed: 09/03/2024] Open
Abstract
Kynurenic acid (KYNA) is an antioxidant degradation product of tryptophan that has been shown to have a variety of cytoprotective, neuroprotective and neuronal signalling properties. However, mammalian transporters and receptors display micromolar binding constants; these are consistent with its typically micromolar tissue concentrations but far above its serum/plasma concentration (normally tens of nanomolar), suggesting large gaps in our knowledge of its transport and mechanisms of action, in that the main influx transporters characterized to date are equilibrative, not concentrative. In addition, it is a substrate of a known anion efflux pump (ABCC4), whose in vivo activity is largely unknown. Exogeneous addition of L-tryptophan or L-kynurenine leads to the production of KYNA but also to that of many other co-metabolites (including some such as 3-hydroxy-L-kynurenine and quinolinic acid that may be toxic). With the exception of chestnut honey, KYNA exists at relatively low levels in natural foodstuffs. However, its bioavailability is reasonable, and as the terminal element of an irreversible reaction of most tryptophan degradation pathways, it might be added exogenously without disturbing upstream metabolism significantly. Many examples, which we review, show that it has valuable bioactivity. Given the above, we review its potential utility as a nutraceutical, finding it significantly worthy of further study and development.
Collapse
Affiliation(s)
- Luana de Fátima Alves
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Building 220, Søltofts Plads, 2800 Kongens Lyngby, Denmark
| | - J. Bernadette Moore
- School of Food Science & Nutrition, University of Leeds, Leeds LS2 9JT, UK;
- Department of Biochemistry, Cell & Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
| | - Douglas B. Kell
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Building 220, Søltofts Plads, 2800 Kongens Lyngby, Denmark
- Department of Biochemistry, Cell & Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown St., Liverpool L69 7ZB, UK
| |
Collapse
|
2
|
Tan X, Li X, Li R, Meng W, Xie Z, Li J, Pang Y, Huang G, Li L, Li H. β-hydroxybutyrate alleviates neurological deficits by restoring glymphatic and inflammation after subarachnoid hemorrhage in mice. Exp Neurol 2024; 378:114819. [PMID: 38763355 DOI: 10.1016/j.expneurol.2024.114819] [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: 03/01/2024] [Revised: 05/07/2024] [Accepted: 05/16/2024] [Indexed: 05/21/2024]
Abstract
BACKGROUND Both glymphatic system dysfunction and inflammatory response aggravate neurological dysfunction after subarachnoid hemorrhage (SAH). Studies have shown that β-hydroxybutyrate (BHB) may mitigate painful diabetic neuropathy (PDN) by upregulating SNTA1 expression and reinstating AQP4 polarity. However, the potential of BHB to ameliorate glymphatic system function and inflammatory response in SAH mice remains uncertain. METHODS The SAH models were constructed by injection of arterial blood into cisterna Magana. Three groups of C57 mice were randomly assigned: Sham, SAH, and BHB. All mice were subjected to neurological function assessment, western blot, immunofluorescence double staining, and RNA-seq. Glymphatic system function was examined with tracer and immunofluorescence double staining, and the differential genes were examined with RNA-seq. In addition, the expression of related inflammation was detected. RESULTS Compared with the SAH group, BHB reinstated AQP4 polarization by upregulating SNTA1 protein to enhance the glymphatic system. According to RNA-seq, the different genes were primarily connected to microglia activation, astrocytes, and inflammation. Western blot and immunofluorescence further confirmed that the related inflammatory protein expression levels were upregulated. BHB attenuated neuroinflammation after SAH. Ultimately, it can mitigate the neurological deficits in SAH mice. CONCLUSION The study reveals a novel mechanism that BHB treatment mitigates neurologic impairment in SAH mice. We propose that BHB may play a neuroprotective effect by enhancing glymphatic system function and attenuating neuroinflammatory subarachnoid hemorrhage.
Collapse
Affiliation(s)
- Xiaoli Tan
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Xiaohong Li
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Ruhua Li
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Weiting Meng
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Zhuoxi Xie
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Jing Li
- Department of Cardiology, The 924th Hospital of Chinese People's Liberation Army Joint Service Support Force, Guilin, China
| | - Yeyu Pang
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Guilan Huang
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China
| | - Li Li
- State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, China.
| | - Hao Li
- Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin 541001, China.
| |
Collapse
|
3
|
Ribeiro KS, Karmakar E, Park C, Garg R, Kung GP, Kadakia I, Gopianand JS, Arun T, Kisselev O, Gnana-Prakasam JP. Iron Regulates Cellular Proliferation by Enhancing the Expression of Glucose Transporter GLUT3 in the Liver. Cells 2024; 13:1147. [PMID: 38994998 PMCID: PMC11240476 DOI: 10.3390/cells13131147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/13/2024] Open
Abstract
Iron is often accumulated in the liver during pathological conditions such as cirrhosis and cancer. Elevated expression of glucose transporters GLUT1 and GLUT3 is associated with reduced overall survival in patients with hepatocellular carcinoma. However, it is not known whether iron can regulate glucose transporters and contribute to tumor proliferation. In the present study, we found that treatment of human liver cell line HepG2 with ferric ammonium citrate (FAC) resulted in a significant upregulation of GLUT3 mRNA and protein in a dose-dependent manner. Similarly, iron accumulation in mice fed with high dietary iron as well as in mice injected intraperitoneally with iron dextran enhanced the GLUT3 expression drastically in the liver. We demonstrated that iron-induced hepatic GLUT3 upregulation is mediated by the LKB1/AMPK/CREB1 pathway, and this activation was reversed when treated with iron chelator deferiprone. In addition, inhibition of GLUT3 using siRNA prevented iron-mediated increase in the expression of cell cycle markers and cellular hyperproliferation. Furthermore, exogenous sodium beta-hydroxybutyrate treatment prevented iron-mediated hepatic GLUT3 activation both in vitro and in vivo. Together, these results underscore the importance of iron, AMPK, CREB1 and GLUT3 pathways in cell proliferation and highlight the therapeutic potential of sodium beta-hydroxybutyrate in hepatocellular carcinoma with high GLUT3 expression.
Collapse
Affiliation(s)
- Kleber S Ribeiro
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Eshani Karmakar
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Christine Park
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Richa Garg
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - George P Kung
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Isha Kadakia
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | | | - Tejas Arun
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Oleg Kisselev
- School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | | |
Collapse
|
4
|
Yamagishi H, Kirai N, Morita A, Kashihara T, Nakahara T. Role of monocarboxylate transporters in AMPK-mediated protection against excitotoxic injury in the rat retina. Eur J Pharmacol 2024; 970:176510. [PMID: 38493917 DOI: 10.1016/j.ejphar.2024.176510] [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: 12/15/2023] [Revised: 03/04/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
Activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathway protects against N-methyl-D-aspartic acid (NMDA)-induced excitotoxic retinal injury. AMPK activation enhances fatty acid metabolism and ketone body synthesis. Ketone bodies are transported into neurons by monocarboxylate transporters (MCTs) and exert neuroprotective effects. In this study, we examined the distribution and expression levels of MCT1 and MCT2 in the retina and analyzed the effects of pharmacological inhibition of MCTs on the protective effects of metformin and 5-aminoimidazole-4-carboxamide (AICAR), activators of AMPK, against NMDA-induced retinal injury in rats. MCT1 was expressed in the blood vessels, processes of astrocytes and Müller cells, and inner segments of photoreceptors in the rat retina, whereas MCT2 was expressed in neuronal cells in the ganglion cell layer (GCL) and in astrocyte processes. The expression levels of MCT2, but not MCT1, decreased one day after intravitreal injection of NMDA (200 nmol). Intravitreal injection of NMDA decreased the number of cells in the GCL compared to the vehicle seven days after injection. Simultaneous injection of metformin (20 nmol) or AICAR (50 nmol) with NMDA attenuated NMDA-induced cell loss in the GCL, and these protective effects were attenuated by AR-C155858 (1 pmol), an inhibitor of MCTs. AR-C155858 alone had no significant effect on the retinal structure. These results suggest that AMPK-activating compounds protect against NMDA-induced excitotoxic retinal injury via mechanisms involving MCTs in rats. NMDA-induced neurotoxicity may be associated with retinal neurodegenerative changes in glaucoma and diabetic retinopathy. Therefore, AMPK-activating compounds may be effective in managing these retinal diseases.
Collapse
Affiliation(s)
- Honoka Yamagishi
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Nozomu Kirai
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Akane Morita
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Toshihide Kashihara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Tsutomu Nakahara
- Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan.
| |
Collapse
|
5
|
Bhartiya S. The Metabolic Shift: Unraveling the Potential of the Ketogenic Diet in Glaucoma Management. J Curr Glaucoma Pract 2024; 18:43-44. [PMID: 39144735 PMCID: PMC11320763 DOI: 10.5005/jp-journals-10078-1435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2024] Open
Abstract
How to cite this article: Bhartiya S. The Metabolic Shift: Unraveling the Potential of the Ketogenic Diet in Glaucoma Management. J Curr Glaucoma Pract 2024;18(2):43-44.
Collapse
Affiliation(s)
- Shibal Bhartiya
- Glaucoma Services, Department of Ophthalmology, Fortis Memorial Research Institute, Gurugram, Haryana, India
| |
Collapse
|
6
|
Pervaiz I, Mehta Y, Sherill K, Patel D, Al-Ahmad AJ. Ketone bodies supplementation restores the barrier function, induces a metabolic switch, and elicits beta-hydroxybutyrate diffusion across a monolayer of iPSC-derived brain microvascular endothelial cells. Microvasc Res 2023; 150:104585. [PMID: 37437687 DOI: 10.1016/j.mvr.2023.104585] [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: 04/04/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/14/2023]
Abstract
Glucose constitutes the main source of energy for the central nervous system (CNS), its entry occurring at the blood-brain barrier (BBB) via the presence of glucose transporter 1 (GLUT1). However, under food intake restrictions, the CNS can utilize ketone bodies (KB) as an alternative source of energy. Notably, the relationship between the BBB and KBs and its effect on their glucose metabolism remains poorly understood. In this study, we investigated the effect of glucose deprivation on the brain endothelium in vitro, and supplementation with KBs using induced pluripotent stem cell (iPSC)-derived brain microvascular endothelial cell-like cells (iBMECs). Glucose-free environment significantly decreased cell metabolic activity and negatively impacted the barrier function. In addition, glucose deprivation did not increase GLUT1 expression but also resulted in a decrease in glucose uptake and glycolysis. Supplementation of glucose-deprived iBMECs monolayers with KB showed no improvement and even worsened upon treatment with acetoacetate. However, under a hypoglycemic condition in the presence of KBs, we noted a slight improvement of the barrier function, with no changes in glucose uptake. Notably, hypoglycemia and/or KB pre-treatment elicited a saturable beta-hydroxybutyrate diffusion across iBMECs monolayers, such diffusion occurred partially via an MCT1-dependent mechanism. Taken together, our study highlights the importance of glucose metabolism and the reliance of the brain endothelium on glucose and glycolysis for its function, such dependence is unlikely to be covered by KBs supplementation. In addition, KB diffusion at the BBB appeared induced by KB pre-treatment and appears to involve an MCT1-dependent mechanism.
Collapse
Affiliation(s)
- Iqra Pervaiz
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America.
| | - Yash Mehta
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America
| | - Kinzie Sherill
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America
| | - Dhavalkumar Patel
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America
| | - Abraham J Al-Ahmad
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America.
| |
Collapse
|
7
|
Venanzi AW, Carmy-Bennun T, Marino FS, Ribeiro M, Hackam AS. Context-Dependent Effects of the Ketogenic Diet on Retinal Ganglion Cell Survival and Axonal Regeneration After Optic Nerve Injury. J Ocul Pharmacol Ther 2023; 39:509-518. [PMID: 37172141 PMCID: PMC10616950 DOI: 10.1089/jop.2023.0001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/06/2023] [Indexed: 05/14/2023] Open
Abstract
Purpose: There is increasing interest in nonpharmacologic approaches to protect retinal ganglion cells (RGCs) after injury and enhance the efficacy of therapeutic molecules. Accumulating evidence demonstrates neuroprotection by the high-fat low-carbohydrate ketogenic diet (KD) in humans and animal models of neurologic diseases. However, no studies to date have examined whether the KD protects RGCs and promotes axonal regrowth after traumatic injury to the optic nerve (ON) or whether it increases efficacy of experimental proregenerative molecules. In this study, we investigated whether the KD promoted RGC survival and axonal regeneration after ON injury in the presence and absence of neuroprotective Wnt3a ligand. Methods: Adult mice were placed on a KD or control diet before ON crush injury and remained on the diet until the end of the experiment. Nutritional ketosis was confirmed by measuring serum beta-hydroxybutyrate levels. Mice were intravitreally injected with Wnt3a ligand or phosphate-buffered saline (PBS), and RGC survival, function, axonal regeneration, and inflammatory responses were measured. Results: Mice fed the KD showed increased RGC survival and reduced inflammatory cells in PBS-injected mice. Also, mice fed the KD had increased RGC functional responses but not increased RGC numbers in the presence of Wnt3a, indicating that the KD did not enhance the prosurvival effect of Wnt3a. The KD did not promote axonal regeneration in the presence or absence of Wnt3a. Conclusions: The KD has a complex protective effect after ON injury and cotreatment with Wnt3a. This work sets the foundation for studies identifying underlying molecular mechanisms.
Collapse
Affiliation(s)
- Alexander W. Venanzi
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Tal Carmy-Bennun
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Felicia S. Marino
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Marcio Ribeiro
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Abigail S. Hackam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| |
Collapse
|
8
|
Kuang G, Halimitabrizi M, Edziah AA, Salowe R, O’Brien JM. The potential for mitochondrial therapeutics in the treatment of primary open-angle glaucoma: a review. Front Physiol 2023; 14:1184060. [PMID: 37601627 PMCID: PMC10433652 DOI: 10.3389/fphys.2023.1184060] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/21/2023] [Indexed: 08/22/2023] Open
Abstract
Glaucoma, an age-related neurodegenerative disease, is characterized by the death of retinal ganglion cells (RGCs) and the corresponding loss of visual fields. This disease is the leading cause of irreversible blindness worldwide, making early diagnosis and effective treatment paramount. The pathophysiology of primary open-angle glaucoma (POAG), the most common form of the disease, remains poorly understood. Current available treatments, which target elevated intraocular pressure (IOP), are not effective at slowing disease progression in approximately 30% of patients. There is a great need to identify and study treatment options that target other disease mechanisms and aid in neuroprotection for POAG. Increasingly, the role of mitochondrial injury in the development of POAG has become an emphasized area of research interest. Disruption in the function of mitochondria has been linked to problems with neurodevelopment and systemic diseases. Recent studies have shown an association between RGC death and damage to the cells' mitochondria. In particular, oxidative stress and disrupted oxidative phosphorylation dynamics have been linked to increased susceptibility of RGC mitochondria to secondary mechanical injury. Several mitochondria-targeted treatments for POAG have been suggested, including physical exercise, diet and nutrition, antioxidant supplementation, stem cell therapy, hypoxia exposure, gene therapy, mitochondrial transplantation, and light therapy. Studies have shown that mitochondrial therapeutics may have the potential to slow the progression of POAG by protecting against mitochondrial decline associated with age, genetic susceptibility, and other pathology. Further, these therapeutics may potentially target already present neuronal damage and symptom manifestations. In this review, the authors outline potential mitochondria-targeted treatment strategies and discuss their utility for use in POAG.
Collapse
Affiliation(s)
- Grace Kuang
- Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, United States
- Penn Medicine Center for Genetics in Complex Diseases, University of Pennsylvania, Philadelphia, PA, United States
| | - Mina Halimitabrizi
- Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, United States
- Penn Medicine Center for Genetics in Complex Diseases, University of Pennsylvania, Philadelphia, PA, United States
| | - Amy-Ann Edziah
- Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, United States
- Penn Medicine Center for Genetics in Complex Diseases, University of Pennsylvania, Philadelphia, PA, United States
| | - Rebecca Salowe
- Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, United States
- Penn Medicine Center for Genetics in Complex Diseases, University of Pennsylvania, Philadelphia, PA, United States
| | - Joan M. O’Brien
- Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, United States
- Penn Medicine Center for Genetics in Complex Diseases, University of Pennsylvania, Philadelphia, PA, United States
| |
Collapse
|
9
|
Favorable Effects of Virgin Coconut Oil on Neuronal Damage and Mortality after a Stroke Incidence in the Stroke-Prone Spontaneously Hypertensive Rat. LIFE (BASEL, SWITZERLAND) 2022; 12:life12111857. [PMID: 36430992 PMCID: PMC9694050 DOI: 10.3390/life12111857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/04/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022]
Abstract
Stroke is consistently one of the top ten causes of morbidity and mortality globally, whose outcomes are quite variable, necessitating case-specific management. Prophylactic diets before the onset of stroke have been implicated to work. In this research, the effects of virgin coconut oil (VCO) on stroke were evaluated using a stroke-prone spontaneously hypertensive rat (SHRSP) model. Eight-week-old SHRSPs were subjected to the repeated oral administration (5 mL/kg/day) of either 1% Tween 80 (group A) or VCO (group B). An early stroke onset was observed due to hypertension that was aggravation by the administration of 1% NaCl in water ad libitum. The following data were collected: the days until stroke occurred, the survival rate until the animal died, and blood pressure (BP) every two weeks using the tail-cuff method. After necropsy, the organs were harvested, and the brain was processed for a routine histopathological analysis. VCO delayed the incidence of it and prolonged their survival. Compared to group A, group B showed a significantly lowered BP by 20 mmHg at four weeks after the start of VCO treatment. Lastly, the brain histopathology showed that the structurally damaged areas were smaller in group B than they were in group A. The VCO could have protective effects on the brain before and even after stroke incidence.
Collapse
|
10
|
Wang FX, Xu CL, Su C, Li J, Lin JY. β-Hydroxybutyrate Attenuates Painful Diabetic Neuropathy via Restoration of the Aquaporin-4 Polarity in the Spinal Glymphatic System. Front Neurosci 2022; 16:926128. [PMID: 35898407 PMCID: PMC9309893 DOI: 10.3389/fnins.2022.926128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Waste removal is essential for maintaining homeostasis and the normal function of the central nervous system (CNS). The glymphatic system based on aquaporin-4 (AQP4) water channels on the endfeet of astrocytes is recently discovered as the excretion pathway for metabolic waste products of CNS. In the CNS, α-syntrophin (SNTA1) directly or indirectly anchors AQP4 in astrocyte membranes facing blood vessels. Studies have indicated that β-hydroxybutyrate (BHB) can raise the expression of SNTA1 and thus restoring AQP4 polarity in mice models with Alzheimer’s disease. The study aims to evaluate the neuroprotective mechanism of BHB in rats with painful diabetic neuropathy (PDN). PDN rats were modeled under a high-fat and high-glucose diet with a low dose of streptozotocin. Magnetic resonance imaging (MRI) was applied to observe the clearance of contrast to indicate the functional variability of the spinal glymphatic system. Mechanical allodynia was assessed by paw withdrawal threshold. The expressions of SNTA1 and AQP4 were tested, and the polarity reversal of AQP4 protein was measured. As demonstrated, PDN rats were manifested with deceased contrast clearance of the spinal glymphatic system, enhanced mechanical allodynia, lower expression of SNTA1, higher expression of AQP4, and reversed polarity of AQP4 protein. An opposite change in the above characteristics was observed in rats being treated with BHB. This is the first study that demonstrated the neuroprotective mechanism of BHB to attenuate PDN via restoration of the AQP4 polarity in the spinal glymphatic system and provides a promising therapeutic strategy for PDN.
Collapse
Affiliation(s)
- Fei-xiang Wang
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Chi-liang Xu
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Can Su
- Department of Medical Imaging, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Jiang Li
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Jing-yan Lin
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China
- *Correspondence: Jing-yan Lin,
| |
Collapse
|
11
|
Abdelrahman AA, Powell FL, Jadeja RN, Jones MA, Thounaojam MC, Bartoli M, Al-Shabrawey M, Martin PM. Expression and activation of the ketone body receptor HCAR2/GPR109A promotes preservation of retinal endothelial cell barrier function. Exp Eye Res 2022; 221:109129. [DOI: 10.1016/j.exer.2022.109129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/02/2022] [Accepted: 05/23/2022] [Indexed: 11/30/2022]
|
12
|
Gough SM, Casella A, Ortega KJ, Hackam AS. Neuroprotection by the Ketogenic Diet: Evidence and Controversies. Front Nutr 2021; 8:782657. [PMID: 34888340 PMCID: PMC8650112 DOI: 10.3389/fnut.2021.782657] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 10/18/2021] [Indexed: 12/22/2022] Open
Abstract
The ketogenic diet (KD) is a high-fat low-carbohydrate diet that has been used for decades as a non-pharmacologic approach to treat metabolic disorders and refractory pediatric epilepsy. In recent years, enthusiasm for the KD has increased in the scientific community due to evidence that the diet reduces pathology and improves various outcome measures in animal models of neurodegenerative disorders, including multiple sclerosis, stroke, glaucoma, spinal cord injury, retinal degenerations, Parkinson's disease and Alzheimer's disease. Clinical trials also suggest that the KD improved quality of life in patients with multiple sclerosis and Alzheimer's disease. Furthermore, the major ketone bodies BHB and ACA have potential neuroprotective properties and are now known to have direct effects on specific inflammatory proteins, transcription factors, reactive oxygen species, mitochondria, epigenetic modifications and the composition of the gut microbiome. Neuroprotective benefits of the KD are likely due to a combination of these cellular processes and other potential mechanisms that are yet to be confirmed experimentally. This review provides a comprehensive summary of current evidence for the effectiveness of the KD in humans and preclinical models of various neurological disorders, describes molecular mechanisms that may contribute to its beneficial effects, and highlights key controversies and current gaps in knowledge.
Collapse
Affiliation(s)
- Sarah M Gough
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Alicia Casella
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Kristen Jasmin Ortega
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Abigail S Hackam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| |
Collapse
|
13
|
Sridharan B, Lee MJ. Ketogenic diet: A promising neuroprotective composition for managing Alzheimer's diseases and its pathological mechanisms. Curr Mol Med 2021; 22:640-656. [PMID: 34607541 DOI: 10.2174/1566524021666211004104703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 11/22/2022]
Abstract
Ketogenic diet and ketone bodies gained significant attention in recent years due to their ability to influence the specific energy metabolism and restoration of mitochondrial homeostasis that can help in hindering the progression of many metabolic diseases including diabetes and neurodegenerative diseases. Ketogenic diet consists of high fat and low carbohydrate contents which makes the body glucose deprived and rely on alternative sources (ketone bodies) for energy. It has been initially designed and supplemented for the treatment of epilepsy and later its influence on many energy-deriving biochemical pathways made it a highly sorted food supplement for many metabolic diseases and even by healthy individuals for body building and calorie restriction. Among the reported therapeutic action over a range of diseases, neurodegenerative disorders especially Alzheimer's disease gained the attention of many researchers and clinicians because of its potency and its easier supplementation as a food additive. Complex pathology and multiple influencing factors of Alzheimer's disease make exploration of its therapeutic strategies a demanding task. It was a common phenomenon that energy deprivation in neurological disorders including Alzheimer's disease, to progress rapidly. The ability of ketone bodies to stabilize the mitochondrial energy metabolism makes it a suitable intervening agent. In this review, we will discuss various research progress made with regards to ketone bodies/ketogenic diet for management of Alzheimer's disease and elaborate in detail about the mechanisms that are influenced during their therapeutic action.
Collapse
Affiliation(s)
- Badrinathan Sridharan
- Department of Applied Chemistry, Chaoyang University of Technology, 168 Jifeng East Road, Taichung. Taiwan
| | - Meng-Jen Lee
- Department of Applied Chemistry, Chaoyang University of Technology, 168 Jifeng East Road, Taichung. Taiwan
| |
Collapse
|
14
|
The Aneugenicity of Ketone Bodies in Colon Epithelial Cells Is Mediated by Microtubule Hyperacetylation and Is Blocked by Resveratrol. Int J Mol Sci 2021; 22:ijms22179397. [PMID: 34502304 PMCID: PMC8430621 DOI: 10.3390/ijms22179397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 01/23/2023] Open
Abstract
Diabetes mellitus (DM) is considered to be associated with an increased risk of colorectal cancer. Recent studies have also revealed that tubulin hyperacetylation is caused by a diabetic status and we have reported previously that, under microtubule hyperacetylation, a microtubule severing protein, katanin-like (KL) 1, is upregulated and contributes to tumorigenesis. To further explore this phenomenon, we tested the effects of the ketone bodies, acetoacetate and β-hydroxybutyrate, in colon and fibroblast cells. Both induced microtubule hyperacetylation that responded differently to a histone deacetylase 3 knockdown. These two ketone bodies also generated intracellular reactive oxygen species (ROS) and hyperacetylation was commonly inhibited by ROS inhibitors. In a human fibroblast-based microtubule sensitivity test, only the KL1 human katanin family member showed activation by both ketone bodies. In primary cultured colon epithelial cells, these ketone bodies reduced the tau protein level and induced KL1- and α-tubulin acetyltransferase 1 (ATAT1)-dependent micronucleation. Resveratrol, known for its tumor preventive and tubulin deacetylation effects, inhibited this micronucleation. Our current data thus suggest that the microtubule hyperacetylation induced by ketone bodies may be a causal factor linking DM to colorectal carcinogenesis and may also represent an adverse effect of them that needs to be controlled if they are used as therapeutics.
Collapse
|
15
|
Tribble JR, Hui F, Jöe M, Bell K, Chrysostomou V, Crowston JG, Williams PA. Targeting Diet and Exercise for Neuroprotection and Neurorecovery in Glaucoma. Cells 2021; 10:295. [PMID: 33535578 PMCID: PMC7912764 DOI: 10.3390/cells10020295] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/15/2021] [Accepted: 01/28/2021] [Indexed: 12/11/2022] Open
Abstract
Glaucoma is a leading cause of blindness worldwide. In glaucoma, a progressive dysfunction and death of retinal ganglion cells occurs, eliminating transfer of visual information to the brain. Currently, the only available therapies target the lowering of intraocular pressure, but many patients continue to lose vision. Emerging pre-clinical and clinical evidence suggests that metabolic deficiencies and defects may play an important role in glaucoma pathophysiology. While pre-clinical studies in animal models have begun to mechanistically uncover these metabolic changes, some existing clinical evidence already points to potential benefits in maintaining metabolic fitness. Modifying diet and exercise can be implemented by patients as an adjunct to intraocular pressure lowering, which may be of therapeutic benefit to retinal ganglion cells in glaucoma.
Collapse
Affiliation(s)
- James R. Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 171 64 Stockholm, Sweden; (J.R.T.); (M.J.)
| | - Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC 3002, Australia; (F.H.); (J.G.C.)
- Department of Optometry & Vision Sciences, The University of Melbourne, Melbourne, VIC 3053, Australia
| | - Melissa Jöe
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 171 64 Stockholm, Sweden; (J.R.T.); (M.J.)
| | - Katharina Bell
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 168751, Singapore; (K.B.); (V.C.)
| | - Vicki Chrysostomou
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 168751, Singapore; (K.B.); (V.C.)
- Duke-NUS Medical School, Singapore 169857, Singapore
| | - Jonathan G. Crowston
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC 3002, Australia; (F.H.); (J.G.C.)
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 168751, Singapore; (K.B.); (V.C.)
- Duke-NUS Medical School, Singapore 169857, Singapore
| | - Pete A. Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 171 64 Stockholm, Sweden; (J.R.T.); (M.J.)
| |
Collapse
|
16
|
Hanyuda A, Rosner BA, Wiggs JL, Willett WC, Tsubota K, Pasquale LR, Kang JH. Low-carbohydrate-diet scores and the risk of primary open-angle glaucoma: data from three US cohorts. Eye (Lond) 2020; 34:1465-1475. [PMID: 32123310 PMCID: PMC7470850 DOI: 10.1038/s41433-020-0820-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND/OBJECTIVES To assess the long-term association between low-carbohydrate dietary patterns and incident primary open-angle glaucoma (POAG), and POAG subtypes defined by highest untreated intraocular pressure (IOP) and by pattern of visual field (VF) loss at diagnosis. SUBJECTS/METHODS We followed 185,638 participants of three large US prospective cohorts biennially (1976-2016, 1986-2016 and 1991-2017). Deciles of three low-carbohydrate-diet scores were calculated to represent adherence to diets lower in carbohydrate and higher in protein and fat from any source, animal sources or plant sources. We confirmed POAG cases (n = 2112) by medical record review and used Cox proportional hazards models to estimate multivariable-adjusted relative risks (MVRRs) and 95% confidence intervals (CIs). RESULTS There was no association between the three types of low-carbohydrate-diet scores and POAG: the MVRR for POAG in the highest vs. lowest deciles was 1.13 (95% CI, 0.91-1.39; Ptrend = 0.40) for the overall score; 1.10 (95% CI, 0.89-1.35; Ptrend = 0.38) for the animal score and 0.96 (95% CI, 0.79-1.18; Ptrend = 0.88) for the vegetable score. No differential associations by IOP level was found (Pheterogeneity ≥ 0.06). However, the vegetable score showed a suggestive inverse association with early paracentral VF loss (highest vs. lowest decile MVRR = 0.78 [95% CI, 0.55-1.10]; Ptrend = 0.12) but not with peripheral VF loss only (MVRR = 1.09 [95% CI, 0.83-1.44]; Ptrend = 0.14; Pheterogeneity = 0.03). CONCLUSIONS Low-carbohydrate diets were not associated with risk of POAG. Our data suggested that higher consumption of fat and protein from vegetable sources substituting for carbohydrates was associated with lower risk of the POAG subtype with initial paracentral VF loss.
Collapse
Affiliation(s)
- Akiko Hanyuda
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
- Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan.
| | - Bernard A Rosner
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Walter C Willett
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Louis R Pasquale
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jae H Kang
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
17
|
Fiedorowicz M, Choragiewicz T, Thaler S, Schuettauf F, Nowakowska D, Wojtunik K, Reibaldi M, Avitabile T, Kocki T, Turski WA, Kaminska A, Grieb P, Zrenner E, Rejdak R, Toro MD. Tryptophan and Kynurenine Pathway Metabolites in Animal Models of Retinal and Optic Nerve Damage: Different Dynamics of Changes. Front Physiol 2019; 10:1254. [PMID: 31632294 PMCID: PMC6781742 DOI: 10.3389/fphys.2019.01254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 09/13/2019] [Indexed: 12/16/2022] Open
Abstract
Kynurenines, products of tryptophan (TRP) metabolism, display neurotoxic (e.g., 3-hydroxykynurenine; 3-HK), or neuroprotective (e.g., kynurenic acid; KYNA) properties. Imbalance between the enzymes constituting the kynurenine pathway (KP) plays a role in several disease, including neurodegeneration. In this study, we track changes in concentrations of tryptophan and its selected metabolites after damage to retinal ganglion cells and link this data with expression of KP enzymes. Brown-Norway rats were subjected to intravitreal N-methyl-D-aspartate (NMDA) injection or partial optic nerve crush (PONC). Retinas were collected 2 and 7 days after the completion of PONC or NMDA injection. Concentrations of TRP, kynurenine (KYN), and KYNA were determined by high performance liquid chromatography (HPLC). Data on gene expression in the rat retina were extracted from GEO, public microarray experiments database. Two days after NMDA injection concentration of TRP decreased, while KYN and KYNA increased. At day 7 compared to day 2 decrease of KYN, KYNA and further reduction of TRP concentration were observed, but on day 7 KYN concentration was still elevated when compared to controls. At day 2 and 7 after NMDA injection no statistically significant alterations of 3-HK were observed. TRP and 3-HK concentration was higher in PONC group than in controls. However, both KYN and KYNA were lower. At day seven concentration of TRP, 3-HK, and KYN was higher, whereas concentration of KYNA declined. In vivo experiments showed that retinal damage or optic nerve lesion affect TRP metabolism via KP. However, the pattern of changes in metabolite concentrations was different depending on the model. In particular, in PONC KYNA and KYN levels were decreased and 3-HK elevated. These observations correspond with data on expression of genes encoding KP enzymes assessed after optic nerve crush or transection. After intraorbital optic nerve crush downregulation of KyatI and KyatIII between 24 h and 3 days after procedure was observed. Kmo expression was transiently upregulated (12 h after the procedures). After intraorbital optic nerve transsection (IONT) Kmo expression was upregulated after 48 h and 7 days, KyatI and KyatIII were downregulated after 12, 48 h, 7 days and upregulated after 15 days. Collected data point to the conclusion that development of therapeutic strategies targeting the KP could be beneficial in diseases involving retinal neurodegeneration.
Collapse
Affiliation(s)
- Michal Fiedorowicz
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Tomasz Choragiewicz
- Department of General Ophthalmology and Pediatric Ophthalmology Service, Medical University of Lublin, Lublin, Poland
| | - Sebastian Thaler
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Frank Schuettauf
- Department of Ophthalmology, University Medical Center, Hamburg-Eppendorf, Hamburg, Germany
| | - Dominika Nowakowska
- Department of General Ophthalmology and Pediatric Ophthalmology Service, Medical University of Lublin, Lublin, Poland
| | - Kamila Wojtunik
- Department of General Ophthalmology and Pediatric Ophthalmology Service, Medical University of Lublin, Lublin, Poland
| | | | | | - Tomasz Kocki
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Waldemar A Turski
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Lublin, Poland
| | - Agnieszka Kaminska
- Faculty of Medicine, Collegium Medicum, Cardinal Stefan Wyszynski University, Warsaw, Poland
| | - Pawel Grieb
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Eberhart Zrenner
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Robert Rejdak
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.,Department of General Ophthalmology and Pediatric Ophthalmology Service, Medical University of Lublin, Lublin, Poland
| | - Mario Damiano Toro
- Department of General Ophthalmology and Pediatric Ophthalmology Service, Medical University of Lublin, Lublin, Poland.,Eye Clinic, University of Catania, Catania, Italy
| |
Collapse
|
18
|
Vidali S, Aminzadeh-Gohari S, Vatrinet R, Iommarini L, Porcelli AM, Kofler B, Feichtinger RG. Lithium and Not Acetoacetate Influences the Growth of Cells Treated with Lithium Acetoacetate. Int J Mol Sci 2019; 20:ijms20123104. [PMID: 31242642 PMCID: PMC6628210 DOI: 10.3390/ijms20123104] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 06/21/2019] [Indexed: 01/06/2023] Open
Abstract
The ketogenic diet (KD), a high-fat/low-carbohydrate/adequate-protein diet, has been proposed as a treatment for a variety of diseases, including cancer. KD leads to generation of ketone bodies (KBs), predominantly acetoacetate (AcAc) and 3-hydroxy-butyrate, as a result of fatty acid oxidation. Several studies investigated the antiproliferative effects of lithium acetoacetate (LiAcAc) and sodium 3-hydroxybutyrate on cancer cells in vitro. However, a critical point missed in some studies using LiAcAc is that Li ions have pleiotropic effects on cell growth and cell signaling. Thus, we tested whether Li ions per se contribute to the antiproliferative effects of LiAcAc in vitro. Cell proliferation was analyzed on neuroblastoma, renal cell carcinoma, and human embryonic kidney cell lines. Cells were treated for 5 days with 2.5, 5, and 10 mM LiAcAc and with equimolar concentrations of lithium chloride (LiCl) or sodium chloride (NaCl). LiAcAc affected the growth of all cell lines, either negatively or positively. However, the effects of LiAcAc were always similar to those of LiCl. In contrast, NaCl showed no effects, indicating that the Li ion impacts cell proliferation. As Li ions have significant effects on cell growth, it is important for future studies to include sources of Li ions as a control.
Collapse
Affiliation(s)
- Silvia Vidali
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, 5020 Salzburg, Austria.
| | - Sepideh Aminzadeh-Gohari
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, 5020 Salzburg, Austria.
| | - Renaud Vatrinet
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy.
| | - Luisa Iommarini
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy.
| | - Anna Maria Porcelli
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, 40126 Bologna, Italy.
| | - Barbara Kofler
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, 5020 Salzburg, Austria.
| | - René Günther Feichtinger
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, 5020 Salzburg, Austria.
| |
Collapse
|
19
|
Changes in tryptophan and kynurenine pathway metabolites in the blood of children treated with ketogenic diet for refractory epilepsy. Seizure 2019; 69:265-272. [PMID: 31129366 DOI: 10.1016/j.seizure.2019.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 04/27/2019] [Accepted: 05/07/2019] [Indexed: 01/01/2023] Open
Abstract
PURPOSE There is growing evidence to support the role of the kynurenine pathway in the anticonvulsant efficacy of ketogenic diets (KDs) in refractory epilepsy. The aim of the present study was to measure blood levels of tryptophan (TRP) and its kynurenine derivatives and correlate them with seizure reduction after starting the KD in children with refractory epilepsy. METHODS Sixteen children (9 F/7 M; 7.1 ± 5.1 years) with refractory epilepsy were treated with the KDs. Clinical efficacy and metabolic ketosis were monitored throughout the study; blood levels of TRP, kynurenine (KYN), kynurenic acid (KYNA), and 3-OH-kynurenine (3-OH-KYN) were measured at 3, 6, and 12 months on the diet and compared to the pre-KD levels. RESULTS Out of 16 children, 14 attained a ≥50% reduction (responders) in seizure frequency 3 months after starting the KD. In the 14 responders, TRP levels decreased numerically (18-25%) but not significantly (P = 0.077) compared to the pre-KD control values. KYN levels decreased significantly (30-57%; P = 0.001) compared to the pre-KD control levels while KYNA levels significantly increased (38-96%; P < 0.001). KYNA/KYN ratios significantly increased (100-323%; P = 0.003) while 3-OH-KYN levels (P = 0.680) and KYN/TRP ratios (P = 0.385) remained unchanged. Higher concentrations of KYNA and lower concentrations of KYN (P < 0.05) were found in patients who attained a higher reduction in seizure frequencies on the KD. CONCLUSIONS We report a pattern of changes in the blood level of kynurenines in patients with refractory epilepsy who started the KD. The results of this study further support the role of specific kynurenines (e.g. KYNA) in the efficacy of the KD in refractory epilepsy.
Collapse
|
20
|
Bai YP, Han LS. Nicorandil alleviated cardiac hypoxia/reoxygenation-induced cytotoxicity via upregulating ketone body metabolism and ACAT1 activity. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2019; 23:37-45. [PMID: 30627008 PMCID: PMC6315096 DOI: 10.4196/kjpp.2019.23.1.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 05/02/2018] [Accepted: 05/23/2018] [Indexed: 11/15/2022]
Abstract
To study the effect of nicorandil pretreatment on ketone body metabolism and Acetyl-CoA acetyltransferase (ACAT1) activity in hypoxia/reoxygenation (H/R)-induced cardiomyocytes. In our study, we applied H9c2 cardiomyocytes cell line to evaluate the cardioprotective effects of nicorandil. We detected mitochondrial viability, cellular apoptosis, reactive oxygen species (ROS) production and calcium overloading in H9c2 cells that exposed to H/R-induced cytotoxicity. Then we evaluated whether nicorandil possibly regulated ketone body, mainly β-hydroxybutyrate (BHB) and acetoacetate (ACAC), metabolism by regulating ACAT1 and Succinyl-CoA:3-keto-acid coenzyme A transferase 1 (OXCT1) protein and gene expressions. Nicorandil protected H9c2 cardiomyocytes against H/R-induced cytotoxicity dose-dependently by mitochondria-mediated anti-apoptosis pathway. Nicorandil significantly decreased cellular apoptotic rate and enhanced the ratio of Bcl-2/Bax expressions. Further, nicorandil decreased the production of ROS and alleviated calcium overloading in H/R-induced H9c2 cells. In crucial, nicorandil upregulated ACAT1 and OXCT1 protein expressions and either of their gene expressions, contributing to increased production of cellular BHB and ACAC. Nicorandil alleviated cardiomyocytes H/R-induced cytotoxicity through upregulating ACAT1/OXCT1 activity and ketone body metabolism, which might be a potential mechanism for emerging study of nicorandil and other KATP channel openers.
Collapse
Affiliation(s)
- Yan Ping Bai
- Department of Cardiology, The Affiliated Hospital of Yan'an University, Yan'an 716000, China
| | - Lei Sen Han
- Department of Cardiology, The Forth Renmin Hospital of Xi'an, Shanxi Province 710004, China
| |
Collapse
|
21
|
Antioxidants prevent inflammation and preserve the optic projection and visual function in experimental neurotrauma. Cell Death Dis 2018; 9:1097. [PMID: 30367086 PMCID: PMC6203845 DOI: 10.1038/s41419-018-1061-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 09/06/2018] [Accepted: 09/10/2018] [Indexed: 12/31/2022]
Abstract
We investigated the role of oxidative stress and the inflammasome in trauma-induced axon degeneration and vision loss using a mouse model. The left eyes of male mice were exposed to over-pressure air waves. Wild-type C57Bl/6 mice were fed normal, high-vitamin-E (VitE), ketogenic or ketogenic-control diets. Mice lacking the ability to produce vitamin C (VitC) were maintained on a low-VitC diet. Visual evoked potentials (VEPs) and retinal superoxide levels were measured in vivo. Tissue was collected for biochemical and histological analysis. Injury increased retinal superoxide, decreased SOD2, and increased cleaved caspase-1, IL-1α, IL-1β, and IL-18 levels. Low-VitC exacerbated the changes and the high-VitE diet mitigated them, suggesting that oxidative stress led to the increase in IL-1α and activation of the inflammasome. The injury caused loss of nearly 50% of optic nerve axons at 2 weeks and astrocyte hypertrophy in mice on normal diet, both of which were prevented by the high-VitE diet. The VEP amplitude was decreased after injury in both control-diet and low-VitC mice, but not in the high-VitE-diet mice. The ketogenic diet also prevented the increase in superoxide levels and IL-1α, but had no effect on IL-1β. Despite this, the ketogenic diet preserved optic nerve axons, prevented astrocyte hypertrophy, and preserved the VEP amplitude. These data suggest that oxidative stress induces priming and activation of the inflammasome pathway after neurotrauma of the visual system. Further, blocking the activation of the inflammasome pathway may be an effective post-injury intervention.
Collapse
|
22
|
Järgen P, Dietrich A, Herling AW, Hammes HP, Wohlfart P. The role of insulin resistance in experimental diabetic retinopathy-Genetic and molecular aspects. PLoS One 2017; 12:e0178658. [PMID: 28575111 PMCID: PMC5456117 DOI: 10.1371/journal.pone.0178658] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/16/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Diabetic retinopathy is characterized by defects in the retinal neurovascular unit. The underlying mechanisms of impairment-including reactive intermediates and growth-factor dependent signalling pathways and their possible interplay are incompletely understood. This study aims to assess the relative role of hyperglycemia and hyperinsulinemia alone or in combination on the gene expression patterning in the retina of animal models of diabetes. MATERIAL AND METHODS As insulinopenic, hyperglycemic model reflecting type 1 diabetes, male STZ-Wistar rats (60mg/kg BW; i.p. injection at life age week 7) were used. Male obese ZDF rats (fa/fa) were used as type-2 diabetes model characterized by persisting hyperglycemia and transient hyperinsulinemia. Male obese ZF rats (fa/fa) were used reflecting euglycemia and severe insulin resistance. All groups were kept till an age of 20 weeks on respective conditions together with appropriate age-matched controls. Unbiased gene expression analysis was performed per group using Affymetrix gene arrays. Bioinformatics analysis included analysis for clustering and differential gene expression, and pathway and upstream activator analysis. Gene expression differences were confirmed by microfluidic card PCR technology. RESULTS The most complex genetic regulation in the retina was observed in ZDF rats with a strong overlap to STZ-Wistar rats. Surprisingly, systemic insulin resistance alone in ZF rats without concomitant hyperglycemia did not induce any significant change in retinal gene expression pattern. Pathway analysis indicate an overlap between ZDF rats and STZ-treated rats in pathways like complement system activation, acute phase response signalling, and oncostatin-M signalling. Major array gene expression changes could be confirmed by subsequent PCR. An analysis of upstream transcriptional regulators revealed interferon-γ, interleukin-6 and oncostatin-M in STZ and ZDF rats. CONCLUSIONS: Systemic hyperinsulinaemia without hyperglycemia does not result in significant gene expression changes in retina. In contrast, persistent systemic hyperglycemia boosts much stronger expression changes with a limited number of known and new key regulators.
Collapse
Affiliation(s)
- Patrick Järgen
- 5 Medical Department, Universitätsmedizin Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Axel Dietrich
- Sanofi Aventis Deutschland GmbH, R&D Lead Generation Candidate Realization, Structure, Design and Informatics, Industriepark Höchst, Frankfurt, Germany
| | - Andreas W. Herling
- Sanofi Aventis Deutschland GmbH, TA Diabetes R&D, Industriepark Höchst, Frankfurt, Germany
| | - Hans-Peter Hammes
- 5 Medical Department, Universitätsmedizin Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Paulus Wohlfart
- Sanofi Aventis Deutschland GmbH, TA Diabetes R&D, Industriepark Höchst, Frankfurt, Germany
- * E-mail:
| |
Collapse
|
23
|
Ketogenic diet improves the spatial memory impairment caused by exposure to hypobaric hypoxia through increased acetylation of histones in rats. PLoS One 2017; 12:e0174477. [PMID: 28355243 PMCID: PMC5371359 DOI: 10.1371/journal.pone.0174477] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/09/2017] [Indexed: 12/28/2022] Open
Abstract
Exposure to hypobaric hypoxia causes neuron cell damage, resulting in impaired cognitive function. Effective interventions to antagonize hypobaric hypoxia-induced memory impairment are in urgent need. Ketogenic diet (KD) has been successfully used to treat drug-resistant epilepsy and improves cognitive behaviors in epilepsy patients and other pathophysiological animal models. In the present study, we aimed to explore the potential beneficial effects of a KD on memory impairment caused by hypobaric hypoxia and the underlying possible mechanisms. We showed that the KD recipe used was ketogenic and increased plasma levels of ketone bodies, especially β-hydroxybutyrate. The results of the behavior tests showed that the KD did not affect general locomotor activity but obviously promoted spatial learning. Moreover, the KD significantly improved the spatial memory impairment caused by hypobaric hypoxia (simulated altitude of 6000 m, 24 h). In addition, the improving-effect of KD was mimicked by intraperitoneal injection of BHB. The western blot and immunohistochemistry results showed that KD treatment not only increased the acetylated levels of histone H3 and histone H4 compared to that of the control group but also antagonized the decrease in the acetylated histone H3 and H4 when exposed to hypobaric hypoxia. Furthermore, KD-hypoxia treatment also promoted PKA/CREB activation and BDNF protein expression compared to the effects of hypoxia alone. These results demonstrated that KD is a promising strategy to improve spatial memory impairment caused by hypobaric hypoxia, in which increased modification of histone acetylation plays an important role.
Collapse
|
24
|
Maciejak P, Szyndler J, Turzyńska D, Sobolewska A, Kołosowska K, Krząścik P, Płaźnik A. Is the interaction between fatty acids and tryptophan responsible for the efficacy of a ketogenic diet in epilepsy? The new hypothesis of action. Neuroscience 2016; 313:130-48. [DOI: 10.1016/j.neuroscience.2015.11.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/10/2015] [Accepted: 11/13/2015] [Indexed: 01/09/2023]
|
25
|
Sabokdast M, Habibi-Rezaei M, Moosavi-Movahedi AA, Ferdousi M, Azimzadeh-Irani E, Poursasan N. Protection by beta-Hydroxybutyric acid against insulin glycation, lipid peroxidation and microglial cell apoptosis. Daru 2015; 23:42. [PMID: 26311627 PMCID: PMC4551523 DOI: 10.1186/s40199-015-0126-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 08/18/2015] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Diabetes mellitus is characterized jointly by hyperglycemia and hyperinsulinemia that make insulin more prone to be glycated and evolve insulin advanced glycation end products (Insulin- AGE). Here, we report the effect of beta-hydroxy butyrate (BHB) (the predominant ketone body) on the formation of insulin-AGE, insulin glycation derived liposomal lipid peroxidation and insulin-AGE toxicity in microglial cells. METHODS The inhibitory effect of BHB was monitored as a result of insulin incubation in the presence of glucose or fructose using AGE-dependent fluorescence, Tyr fluorescence as well as anilinonaphthalenesulfonate (ANS) andthioflavin T (ThT) binding, and circular dichroism (CD) investigations. To study lipid peroxidation induced by insulin glycation, thiobarbituric acid (TBA) assay and thiobarbituric acid reactive substance (TBARS) monitoring were used. The effect of insulin-AGE on microglial viability was investigated by 3-(4, 5 dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide (MTT) cell assay and Annexin V/propidium iodide (PI) staining. RESULTS Here we are reporting the inhibitory effect of BHB on insulin glycation and generation of insulin-AGE as a possible explanation for insulin resistance. Moreover, the protective effect of BHB on consequential glycation derived liposomal lipid peroxidation as a causative event in microglial apoptosis is reported. CONCLUSION The reduced insulin fibril formation, structural inertia to glycation involved conformational changes, anti-lipid peroxidation effect, and increasing microglia viability indicated the protective effect of BHB that disclose insight on the possible preventive effect of BHB on Alzheimer's disease.
Collapse
Affiliation(s)
- Manijheh Sabokdast
- School of Biology, College of Science, University of Tehran, Tehran, Iran.
- Present address: Department of agronomy, and plant breeding, College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.
| | - Mehran Habibi-Rezaei
- School of Biology, College of Science, University of Tehran, Tehran, Iran.
- Nano-Biomedicine Center of Excellence, Nanoscience and Nanotechnology Research Center, University of Tehran, Tehran, Iran.
| | - Ali Akbar Moosavi-Movahedi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
- Center of Excellence in Biothermodynamics, University of Tehran, Tehran, Iran.
| | - Maryam Ferdousi
- School of Biology, College of Science, University of Tehran, Tehran, Iran.
| | | | - Najmeh Poursasan
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
| |
Collapse
|
26
|
Zarnowski T, Choragiewicz TJ, Schuettauf F, Zrenner E, Rejdak R, Gasior M, Zarnowska I, Thaler S. Ketogenic Diet Attenuates NMDA-Induced Damage to Rat's Retinal Ganglion Cells in an Age-Dependent Manner. Ophthalmic Res 2015; 53:162-7. [DOI: 10.1159/000379753] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 02/08/2015] [Indexed: 11/19/2022]
|
27
|
Singh R, Devi S, Gollen R. Role of free radical in atherosclerosis, diabetes and dyslipidaemia: larger-than-life. Diabetes Metab Res Rev 2015; 31:113-26. [PMID: 24845883 DOI: 10.1002/dmrr.2558] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 04/17/2014] [Accepted: 04/29/2014] [Indexed: 02/02/2023]
Abstract
During the past few decades, there have been numerous studies related to free radical chemistry. Free radicals including reactive oxygen species (ROS) and reactive nitrogen species are generated by the human body by various endogenous systems, exposure to different physiochemical conditions, or pathological states, and have been implicated in the pathogenesis of many diseases. These free radicals are also the common by-products of many oxidative biochemical reactions in cells. When free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress ensues. They adversely alter lipids, proteins, and DNA, which trigger a number of human diseases. In a number of pathophysiological conditions, the delicate equilibrium between free radical production and antioxidant capability is distorted, leading to oxidative stress and increased tissue injury. ROS which are mainly produced by vascular cells are implicated as possible underlying pathogenic mechanisms in a progression of cardiovascular diseases including ischemic heart disease, atherosclerosis, cardiac arrhythmia, hypertension, and diabetes. This review summarizes the key roles played by free radicals in the pathogenesis of atherosclerosis, diabetes, and dyslipidaemia. Although not comprehensive, this review also provides a brief perspective on some of the current research being conducted in this area for a better understanding of the role free radicals play in the pathogenesis of atherosclerosis, diabetes, and dyslipidaemia.
Collapse
Affiliation(s)
- Randhir Singh
- MM College of Pharmacy, Maharishi Markandeshwar University, Mullana, Ambala, India
| | | | | |
Collapse
|
28
|
Thaler S, Haritoglou C, Schuettauf F, Choragiewicz T, May CA, Gekeler F, Fischer MD, Langhals H, Schatz A. In vivo biocompatibility of a new cyanine dye for ILM peeling. Eye (Lond) 2014; 29:428-35. [PMID: 25523205 DOI: 10.1038/eye.2014.295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 10/02/2014] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To investigate the biocompatibility of the new cyanine dye: 3,3'-Di-(4-sulfobutyl)-1,1,1',1'-tetramethyl-di-1H-benz[e]indocarbocyanine (DSS) as a vital dye for intraocular application in an in vivo rat model and to evaluate the effects of this dye on retinal structure and function. METHODS DSS at a concentration of 0.5% was applied via intravitreal injections to adult Brown Norway rats with BSS serving as a control. Retinal toxicity was assessed 7 days later by means of retinal ganglion cell (RGC) counts, light microscopy, optical coherence tomography (OCT), and electroretinography (ERG). RESULTS No significant decrease in RGC numbers was observed. No structural changes of the central retina were observed either in vivo (OCT) or under light microscopy. ERGs detected a temporary reduction of retinal function 7 days after injection; this was no longer evident 14 days after injection. CONCLUSIONS DSS showed good biocompatibility in a well-established experimental in vivo setting and may be usable for intraocular surgery as an alternative to other cyanine dyes. In contrast to indocyanine green, it additionally offers fluorescence in the visual spectrum. Further studies with other animal models are needed before translation into clinical application.
Collapse
Affiliation(s)
- S Thaler
- Eye Clinic and Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - C Haritoglou
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - F Schuettauf
- Eye Clinic and Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - T Choragiewicz
- 1] Eye Clinic and Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany [2] 1st Eye Hospital, Medical University of Lublin, Lublin, Poland
| | - C A May
- Department of Anatomy, Medical Faculty 'Carl Gustav Carus', Technical University of Dresden, Dresden, Germany
| | - F Gekeler
- Eye Clinic and Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - M D Fischer
- Eye Clinic and Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - H Langhals
- Department of Chemistry, Ludwig-Maximilians-University, Munich, Germany
| | - A Schatz
- Eye Clinic and Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| |
Collapse
|
29
|
Nakamura S, Hisamura R, Shimoda S, Shibuya I, Tsubota K. Fasting mitigates immediate hypersensitivity: a pivotal role of endogenous D-beta-hydroxybutyrate. Nutr Metab (Lond) 2014; 11:40. [PMID: 25302070 PMCID: PMC4190937 DOI: 10.1186/1743-7075-11-40] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 07/25/2014] [Indexed: 12/22/2022] Open
Abstract
Background Fasting is a rigorous type of dietary restriction that is associate with a number of health benefits. During fasting, ketone bodies significantly increase in blood and become major body fuels, thereby sparing glucose. In the present study, we investigated effects of fasting on hypersensitivity. In addition, we also investigated the possible role of D-beta-hydroxybutyrate provoked by fasting in the attenuation of immediate hypersensitivity by fasting. Methods Effects of fasting on systemic anaphylaxis were examined using rat model of toluene 2, 4-diisocyanate induced nasal allergy. In addition to food restriction, a ketogenic high-fat and low-carbohydrate diet that accelerates fatty acid oxidation and systemic instillation of D-beta-hydroxybutyrate were employed to elevate internal D-beta-hydroxybutyrate concentration. We assessed relationship between degranulation of rat peritoneal mast cells and internal D-beta-hydroxybutyrate concentration in each treatment. Changes in [Ca2+]i responses to compound 48/80 were analyzed in fura 2-loaded rat peritoneal mast cells derived from the ketogenic diet and fasting. Results Immediate hypersensitivity reaction was significantly suppressed by fasting. A significant reduction in mast cells degranulation, induced by mast cell activator compound 48/80, was observed in rat peritoneal mast cells delivered from the 24 hours fasting treatment. In addition, mast cells delivered from a ketogenic diet and D-beta-hydroxybutyrate infusion treatment also had reduced mast cell degranulation and systemic D-beta-hydroxybutyrate concentrations were elevated to similar extent as the fasting state. The peak increase in [Ca2+]i was significantly lower in the ketogenic diet and fasting group than that in the control diet group. Conclusions The results of the present study demonstrates that fasting suppress hypersensitivity reaction, and indicate that increased level of D-beta-hydroxybutyrate by fasting plays an important role, via the stabilization of mast cells, in suppression of hypersensitivity reaction.
Collapse
Affiliation(s)
- Shigeru Nakamura
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjyuku, Tokyo 160-8582, Japan
| | - Ryuji Hisamura
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjyuku, Tokyo 160-8582, Japan
| | | | - Izumi Shibuya
- Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjyuku, Tokyo 160-8582, Japan ; Health Science Laboratory, Keio Research Institute at SFC, Keio University, Kanagawa, Japan
| |
Collapse
|
30
|
Abstract
AbstractMemory consolidation is the process by which relevant information is selected and transferred from a short-term, fragile state, into a stable, longer term domain from which it can be recalled. Effective memory underpins our ability to carry out everyday activities. When memory consolidation fails, such as in Alzheimer’s disease, the consequences can be devastating. Understanding the neurobiology of memory will help develop treatments for patients with memory loss. Here we describe the myriad processes involved in memory consolidation, including cholinergic and dopaminergic neurotransmission predominantly in hippocampal networks. We discuss established therapies as well as potential novel strategies for boosting cognition. Future approaches to enhancement of memory consolidation include not only pharmacological and neurosurgical treatments, but also lifestyle interventions — for example, modifications to sleep, exercise and diet.
Collapse
|
31
|
Hui L, Chen X, Bhatt D, Geiger NH, Rosenberger TA, Haughey NJ, Masino SA, Geiger JD. Ketone bodies protection against HIV-1 Tat-induced neurotoxicity. J Neurochem 2012; 122:382-91. [PMID: 22524563 DOI: 10.1111/j.1471-4159.2012.07764.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
HIV-1-associated neurocognitive disorder (HAND) is a syndrome that ranges clinically from subtle neuropsychological impairments to profoundly disabling HIV-associated dementia. Not only is the pathogenesis of HAND unclear, but also effective treatments are unavailable. The HIV-1 transactivator of transcription protein (HIV-1 Tat) is strongly implicated in the pathogenesis of HAND, in part, because of its well-characterized ability to directly excite neurons and cause neurotoxicity. Consistent with previous findings from others, we demonstrate here that HIV-1 Tat induced neurotoxicity, increased intracellular calcium, and disrupted a variety of mitochondria functions, such as reducing mitochondrial membrane potential, increasing levels of reactive oxygen species, and decreasing bioenergetic efficiency. Of therapeutic importance, we show that treatment of cultured neurons with ketone bodies normalized HIV-1 Tat induced changes in levels of intracellular calcium, mitochondrial function, and neuronal cell death. Ketone bodies are normally produced in the body and serve as alternative energy substrates in tissues including brain and can cross the blood-brain barrier. Ketogenic strategies have been used clinically for treatment of neurological disorders and our current results suggest that similar strategies may also provide clinical benefits in the treatment of HAND.
Collapse
Affiliation(s)
- Liang Hui
- Department of Pharmacology, Physiology and Therapeutics, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, USA
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Wang R, Luan X, Mu Y, Jia H, Xu J. Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist inhibits apoptosis of retinal ganglion cells in a rabbit model of optic nerve injury. Neural Regen Res 2012; 7:731-5. [PMID: 25737694 PMCID: PMC4345653 DOI: 10.3969/j.issn.1673-5374.2012.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 02/11/2012] [Indexed: 11/30/2022] Open
Abstract
A rabbit model of traumatic optic nerve injury, established by occlusion of the optic nerve using a vascular clamp, was used to investigate the effects of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist GYKI 52466 on apoptosis of retinal ganglion cells following nerve injury. Hematoxylin-eosin staining and a terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that retinal ganglion cells gradually decreased with increasing time of optic nerve injury, while GYKI 52466 could inhibit this process. The results demonstrate that following acute optic nerve injury, apoptosis of retinal ganglion cells is a programmed process, which can be inhibited by the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist.
Collapse
Affiliation(s)
- Ruijia Wang
- Department of Neurosurgery, Second Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China
| | - Xinping Luan
- Department of Neurosurgery, Second Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China
| | - Yiti Mu
- Department of Neurosurgery, Second Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China
| | - Hongyu Jia
- Department of Neurosurgery, Second Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China
| | - Jingxuan Xu
- Department of Neurosurgery, Second Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China
| |
Collapse
|
33
|
Zarnowski T, Tulidowicz-Bielak M, Kosior-Jarecka E, Zarnowska I, A. Turski W, Gasior M. A ketogenic diet may offer neuroprotection in glaucoma and mitochondrial diseases of the optic nerve. MEDICAL HYPOTHESIS, DISCOVERY & INNOVATION OPHTHALMOLOGY JOURNAL 2012; 1:45-9. [PMID: 24600621 PMCID: PMC3939735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Glaucoma is a chronic optic nerve disease in which the primary damage occurs to the retinal ganglion cell axons. Therapies that prevent the death of retinal ganglion cells should be theoretically beneficial. Despite promising preclinical studies, however, almost all clinical studies with pharmacological approaches for neuroprotection in neurologic and eye diseases, including glaucoma, have so far failed to show efficacy. As the evidence supporting the neuroprotective efficacy of a ketogenic diet (KD) in a number of neurodegenerative diseases continues to grow, it is conceivable that this metabolic approach might be useful in chronic glaucoma. Putative cellular mechanisms underlying the neuroprotective activity of the KD have been identified in neurological studies, including effects on energy metabolism, the GABA system, glutamate-mediated toxicity, antioxidant mechanisms, programmed cell death, anti-inflammatory mechanisms, and the production of kynurenic acid. Of note, the same mechanisms are thought to be involved in glaucoma. Given these mechanistic similarities, testing the KD for its efficacy in neurodegenerative diseases of the eye is proposed.
Collapse
Affiliation(s)
| | | | | | | | - Waldemar A. Turski
- Department of Experimental and Clinical Pharmacology, Medical University, Lublin, Poland
| | - Maciej Gasior
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelpia, USA
| |
Collapse
|
34
|
Żarnowski T, Chorągiewicz T, Tulidowicz-Bielak M, Thaler S, Rejdak R, Żarnowski I, Turski WA, Gasior M. Ketogenic diet increases concentrations of kynurenic acid in discrete brain structures of young and adult rats. J Neural Transm (Vienna) 2011; 119:679-84. [PMID: 22200857 PMCID: PMC3359463 DOI: 10.1007/s00702-011-0750-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Accepted: 12/01/2011] [Indexed: 12/31/2022]
Abstract
Targeting mechanisms that result in increased concentrations of kynurenic acid (KYNA) in the brain has been considered as a therapeutic approach for the treatment of epilepsy and certain neurodegenerative disorders. Recently, KYNA has been implicated in the effects produced by the high-fat and low-protein/carbohydrate ketogenic diet (KD) in a report demonstrating an increased production of KYNA in vitro by one of the ketone bodies, β-hydroxybutyrate, elevated by the KD. To further explore this association, brain concentrations of KYNA were compared in young (3 weeks old) and adult (8–10 weeks old) rats that were chronically exposed to the KD and regular diet. Exposure to the KD resulted in the anticipated elevations of β-hydroxybutyrate with accompanying decreases in glucose concentrations. In comparison to rats fed the regular diet, KYNA concentrations were significantly (p < 0.05) increased in the hippocampus (256 and 363% increase in young and adult rats, respectively) and in the striatum (381 and 191% increase in young and adult rats, respectively) in KD-fed rats. KD-induced increases in KYNA concentrations in young versus adult rats in the hippocampus and striatum were comparable (p > 0.05). Exposure to the KD had no effect on KYNA concentrations in the cortex of young and adult rats (p > 0.05). In summary, chronic exposure to the KD resulted in several-fold increases in KYNA concentrations in discrete brain structures in the rats. Thus, the relevant clinical question for further exploration is whether KD-induced increases in KYNA concentrations can translate into clinically significant improvements in neuropsychiatric diseases associated with KYNA hypofunction.
Collapse
|
35
|
Schuettauf F, Stein T, Choragiewicz TJ, Rejdak R, Bolz S, Zurakowski D, Varde MA, Laties AM, Thaler S. Caspase inhibitors protect against NMDA-mediated retinal ganglion cell death. Clin Exp Ophthalmol 2011; 39:545-54. [DOI: 10.1111/j.1442-9071.2010.02486.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|