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Weber CM, Moiz B, Clyne AM. Brain microvascular endothelial cell metabolism and its ties to barrier function. VITAMINS AND HORMONES 2024; 126:25-75. [PMID: 39029976 DOI: 10.1016/bs.vh.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2024]
Abstract
Brain microvascular endothelial cells, which lie at the interface between blood and brain, are critical to brain energetics. These cells must precisely balance metabolizing nutrients for their own demands with transporting nutrients into the brain to sustain parenchymal cells. It is essential to understand this integrated metabolism and transport so that we can develop better diagnostics and therapeutics for neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis, and traumatic brain injury. In this chapter, we first describe brain microvascular endothelial cell metabolism and how these cells regulate both blood flow and nutrient transport. We then explain the impact of brain microvascular endothelial cell metabolism on the integrity of the blood-brain barrier, as well as how metabolites produced by the endothelial cells impact other brain cells. We detail some ways that cell metabolism is typically measured experimentally and modeled computationally. Finally, we describe changes in brain microvascular endothelial cell metabolism in aging and neurodegenerative diseases. At the end of the chapter, we highlight areas for future research in brain microvascular endothelial cell metabolism. The goal of this chapter is to underscore the importance of nutrient metabolism and transport at the brain endothelium for cerebral health and neurovascular disease treatment.
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Affiliation(s)
- Callie M Weber
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Bilal Moiz
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Alisa Morss Clyne
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States.
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Latif S, Kang YS. Blood-Brain Barrier Solute Carrier Transporters and Motor Neuron Disease. Pharmaceutics 2022; 14:2167. [PMID: 36297602 PMCID: PMC9608738 DOI: 10.3390/pharmaceutics14102167] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/22/2022] [Accepted: 10/04/2022] [Indexed: 01/21/2024] Open
Abstract
Defective solute carrier (SLC) transporters are responsible for neurotransmitter dysregulation, resulting in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). We provided the role and kinetic parameters of transporters such as ASCTs, Taut, LAT1, CAT1, MCTs, OCTNs, CHT, and CTL1, which are mainly responsible for the transport of essential nutrients, acidic, and basic drugs in blood-brain barrier (BBB) and motor neuron disease. The affinity for LAT1 was higher in the BBB than in the ALS model cell line, whereas the capacity was higher in the NSC-34 cell lines than in the BBB. Affinity for MCTs was lower in the BBB than in the NSC-34 cell lines. CHT in BBB showed two affinity sites, whereas no expression was observed in ALS cell lines. CTL1 was the main transporter for choline in ALS cell lines. The half maximal inhibitory concentration (IC50) analysis of [3H]choline uptake indicated that choline is sensitive in TR-BBB cells, whereas amiloride is most sensitive in ALS cell lines. Knowledge of the transport systems in the BBB and motor neurons will help to deliver drugs to the brain and develop the therapeutic strategy for treating CNS and neurological diseases.
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Affiliation(s)
| | - Young-Sook Kang
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women’s University, 100 Cheongpa-ro 47-gil, Yongsan-gu, Seoul 04310, Korea
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Luo S, He J, Huang S, Wang X, Su Y, Li Y, Chen Y, Yang G, Huang B, Guo S, Zhou L, Luo X. Emodin targeting the colonic metabolism via PPARγ alleviates UC by inhibiting facultative anaerobe. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2022; 104:154106. [PMID: 35728384 DOI: 10.1016/j.phymed.2022.154106] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 04/01/2022] [Accepted: 04/14/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Emodin is an active ingredient of traditional Chinese medicine Rheum palmatum L. and Polygonum cuspidatum, which possesses anti-inflammatory and intestinal mucosal protection effects. Our previous study found that emodin significantly alleviated ulcerative colitis induced by sodium dextran sulfate (DSS). In this study, we found the underlying mechanism of emodin on ulcerative colitis (UC). PURPOSE We aimed to further explore the mechanism of emodin in the treatment of ulcerative colitis from the perspective of metabolism and intestinal flora. METHODS Ulcerative colitis was induced by 3% sodium dextran sulfate (DSS) on mice, and the mice were respectively treated with mesalazine, rosiglitazone, emodin, and emodin combined with GW9662 (PPARγ inhibitor) simultaneously. Weight changes, the disease activity index (DAI), colonic length, and pathologic changes in colon were used to evaluate the efficacy of emodin. LC-MS/MS was performed for metabolomics analysis of colon. In addition, intestinal flora was assessed using 16S rDNA sequencing. A vector-based short hairpin RNA (shRNA) method was used to silence PPARγ gene expression in Caco-2 cells. RESULTS Emodin binds to the active site of PPARγ protein and forms hydrogen bond interaction with ARG288 and CYS285 amino acids. Furthermore, Emodin significantly promotes the protein expression of PPARγ, while inhibiting iNOS and NF-kB p65 in UC mice, however, this effect is hardly shown when it is combined with GW9662 (the inhibitor of PPARγ). Meanwhile, emodin suppresses the expression of iNOS in Caco-2 cells induced with IFNγ and IL-22, but has no effect on its expression in shPPARγ-Caco-2 cells. In addition, through activating PPARγ signal pathway, emodin is capable of regulating colonic metabolism including oxidative phosphorylation and citrulline metabolism and effecting luminal availability of oxygen and nitrate. This promotes the recovery of anoxic environment of colon epithelial cells, which strains the growth and expansion of Enterobacteriaceae. CONCLUSION The mechanism of Emodin in the treatment of ulcerative colitis relies on its regulation of PPARγ signal pathway, which could modulate colonic metabolism and restore intestinal homeostasis.
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Affiliation(s)
- Shuang Luo
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China; The fourth Clinical Medical College of Guangzhou University of Chinese Medicine, China
| | - Jinrong He
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China
| | - Shaowei Huang
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China
| | - Xiaojing Wang
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China
| | - Yulin Su
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China
| | - Yanyang Li
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China
| | - Yanping Chen
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China
| | - Guanghua Yang
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China
| | - Bin Huang
- The fourth Clinical Medical College of Guangzhou University of Chinese Medicine, China
| | - Shaoju Guo
- The fourth Clinical Medical College of Guangzhou University of Chinese Medicine, China
| | - Lian Zhou
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China.
| | - Xia Luo
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Room C206, Pharmaceutical building, No. 232 Outer Ring Road, Panyu District, Guangzhou City, Guang Dong Province, China.
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Latif S, Kang YS. Differences of Transport Activity of Arginine and Regulation on Neuronal Nitric Oxide Synthase and Oxidative Stress in Amyotrophic Lateral Sclerosis Model Cell Lines. Cells 2021; 10:cells10123554. [PMID: 34944061 PMCID: PMC8700480 DOI: 10.3390/cells10123554] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/10/2021] [Accepted: 12/15/2021] [Indexed: 01/09/2023] Open
Abstract
L-Arginine, a semi-essential amino acid, was shown to delay dysfunction of motor neurons and to prolong the lifespan, upon analysis of transgenic mouse models of amyotrophic lateral sclerosis (ALS). We investigated the transport function of arginine and neuronal nitric oxide synthase (nNOS) expression after pretreatment with L-arginine in NSC-34 hSOD1WT (wild-type, WT) and hSOD1G93A (mutant-type, MT) cell lines. [3H]L-Arginine uptake was concentration-dependent, voltage-sensitive, and sodium-independent in both cell lines. Among the cationic amino acid transporters family, including system y+, b0,+, B0,+, and y+L, system y+ is mainly involved in [3H]L-arginine transport in ALS cell lines. System b0,+ accounted for 23% of the transport in both cell lines. System B0,+ was found only in MT, and whereas, system y+L was found only in WT. Lysine competitively inhibited [3H]L-arginine uptake in both cell lines. The nNOS mRNA expression was significantly lower in MT than in WT. Pretreatment with arginine elevated nNOS mRNA levels in MT. Oxidizing stressor, H2O2, significantly decreased their uptake; however, pretreatment with arginine restored the transport activity in both cell lines. In conclusion, arginine transport is associated with system y+, and neuroprotection by L-arginine may provide an edge as a possible therapeutic target in the treatment of ALS.
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Latif S, Kang YS. Change in Cationic Amino Acid Transport System and Effect of Lysine Pretreatment on Inflammatory State in Amyotrophic Lateral Sclerosis Cell Model. Biomol Ther (Seoul) 2021; 29:498-505. [PMID: 33935047 PMCID: PMC8411026 DOI: 10.4062/biomolther.2021.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 11/21/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a lethal neurological disorder characterized by the deterioration of motor neurons. The aim of this study was to investigate alteration of cationic amino acid transporter (CAT-1) activity in the transport of lysine and the pretreatment effect of lysine on pro-inflammatory states in an amyotrophic lateral sclerosis cell line. The mRNA expression of cationic amino acid transporter 1 was lower in NSC-34/hSOD1G93A (MT) than the control cell line (WT), lysine transport is mediated by CAT-1 in NSC-34 cell lines. The uptake of [3H]L-lysine was Na+-independent, voltage-sensitive, and strongly inhibited by inhibitors and substrates of cationic amino acid transporter 1 (system y+). The transport process involved two saturable processes in both cell lines. In the MT cell line, at a high-affinity site, the affinity was 9.4-fold higher and capacity 24-fold lower than that in the WT; at a low-affinity site, the capacity was 2.3-fold lower than that in the WT cell line. Donepezil and verapamil competitively inhibited [3H]L-lysine uptake in the NSC-34 cell lines. Pretreatment with pro-inflammatory cytokines decreased the uptake of [3H]L-lysine and mRNA expression levels in both cell lines; however, the addition of L-lysine restored the transport activity in the MT cell lines. L-Lysine exhibited neuroprotective effects against pro-inflammatory states in the ALS disease model cell lines. In conclusion, studying the alteration in the expression of transporters and characteristics of lysine transport in ALS can lead to the development of new therapies for neurodegenerative diseases.
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Affiliation(s)
- Sana Latif
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Young-Sook Kang
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women's University, Seoul 04310, Republic of Korea
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Pammi N, Bhukya KK, Lunavath RK, Bhukya B. Bioprospecting of Palmyra Palm ( Borassus flabellifer) Nectar: Unveiling the Probiotic and Therapeutic Potential of the Traditional Rural Drink. Front Microbiol 2021; 12:683996. [PMID: 34262545 PMCID: PMC8274697 DOI: 10.3389/fmicb.2021.683996] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/04/2021] [Indexed: 01/27/2023] Open
Abstract
The present study investigates the therapeutic and probiotic attributes of traditional Toddy Palm Nectar (TPN). Glucose was found to be the highest with 4.37 mg/ml and arabinose was the least with 2.85 mg/ml. The average ethanol concentration of fresh TPN was found to be 0.3 mg/ml. The nutritional profile of TPN revealed 18 volatile fatty acids, the major one being hexadecenoic acid (M/Z 74). Amino acid profiling showed 26 amino acids, with OH-lysine-2 the highest (12.86%). About 120 morphologically distinct lactic acid bacteria (LAB) were isolated from 26 TPN samples, based on differential growth and in vitro probiotic characteristics. After 16S rRNA sequencing, four indigenous LAB strains were identified as Lactobacillus plantarum group OUBN1, Enterococcus faecium OUBN3, Pediococcus acidilactici OUBN4, and Pediococcus pentosaceous OUBN5 and their sequences were deposited to NCBI. Microbiological safety evaluation studies showed the absence of hemolytic, gelatinolytic and proteolytic activity. The bacterial isolate OUBN3 showed a maximum survival rate of 6.91 ± 0.04 log cfu/ml at acidic pH 2.5 and isolate OUBN5 showed 6.94 ± 0.02 log cfu/ml at pH 3.0. Similarly, the isolate OUBN5 showed 7.92 ± 0.03 log cfu/ml to 0.3% ox-bile after 4 h and 8.94 ± 0.03 log cfu/ml to simulated gastric juice after 3 h of treatments. OUBN1 expressed the highest autoaggregation (81.76 ± 1.25%), cell surface hydrophobicity (79.71 ± 3.42%), and displayed the maximum coaggregation with E. coli MTCC452 (76.96%), K. pneumoniae MTCC109 (75.62%), and S. aureus MTCC902 (70.69%). All strains showed significant antibiotic and antimicrobial activity. Isolate OUBN1 displayed hydroxyl radical scavenging activity (68.71 ± 1.0%) with an IC50 value of 75.62 μg/ml and the highest anti-cancer activity (percentage inhibition of 88.55) against HT-29 cells. Based on the characteristics observed, L. plantarum group OUBN1 and P. pentosaceous OUBN5 were found to be potential isolates to employ as probiotic microbiota in food and forage preparations. These findings reinforce the fact that LAB isolated from TPN could be exploited as an alternative means toward potential therapeutic applications.
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Affiliation(s)
| | | | | | - Bhima Bhukya
- Centre for Microbial and Fermentation Technology, Department of Microbiology, University College of Science, Osmania University, Hyderabad, India
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Gyawali A, Hyeon SJ, Ryu H, Kang YS. The Alteration of L-Carnitine Transport and Pretreatment Effect under Glutamate Cytotoxicity on Motor Neuron-Like NSC-34 Lines. Pharmaceutics 2021; 13:pharmaceutics13040551. [PMID: 33919926 PMCID: PMC8070968 DOI: 10.3390/pharmaceutics13040551] [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: 03/15/2021] [Revised: 04/07/2021] [Accepted: 04/12/2021] [Indexed: 12/04/2022] Open
Abstract
L-Carnitine (LC) is essential for transporting fatty acids to the mitochondria for β-oxidation. This study was performed to examine the alteration of the LC transport system in wild type (WT, NSC-34/hSOD1WT) and mutant type (MT, NSC-34/hSOD1G93A) amyotrophic lateral sclerosis (ALS) models. The uptake of [3H]L-carnitine was dependent on time, temperature, concentration, sodium, pH, and energy in both cell lines. The Michaelis–Menten constant (Km) value as well as maximum transport velocity (Vmax) indicated that the MT cell lines showed the higher affinity and lower capacity transport system, compared to that of the WT cell lines. Additionally, LC uptake was inhibited by organic cationic compounds but unaffected by organic anions. OCTN1/slc22a4 and OCTN2/slc22a5 siRNA transfection study revealed both transporters are involved in LC transport in NSC-34 cell lines. Additionally, slc22a4 and slc22a5 was significantly decreased in mouse MT models compared with that in ALS WT littermate models in the immune-reactivity study. [3H]L-Carnitine uptake and mRNA expression pattern showed the pretreatment of LC and acetyl L-carnitine (ALC) attenuated glutamate induced neurotoxicity in NSC-34 cell lines. These findings indicate that LC and ALC supplementation can prevent the neurotoxicity and neuro-inflammation induced by glutamate in motor neurons.
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Affiliation(s)
- Asmita Gyawali
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women’s University, Seoul 04310, Korea;
| | - Seung Jae Hyeon
- Laboratory for Brain Gene Regulation and Epigenetics, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea; (S.J.H.); (H.R.)
| | - Hoon Ryu
- Laboratory for Brain Gene Regulation and Epigenetics, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea; (S.J.H.); (H.R.)
| | - Young-Sook Kang
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women’s University, Seoul 04310, Korea;
- Correspondence: ; Tel.: +82-2-710-9562; Fax: +82-2-710-9871
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Citrulline supplementation attenuates the development of non-alcoholic steatohepatitis in female mice through mechanisms involving intestinal arginase. Redox Biol 2021; 41:101879. [PMID: 33550112 PMCID: PMC7868995 DOI: 10.1016/j.redox.2021.101879] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is by now the most prevalent liver disease worldwide. The non-proteogenic amino acid l-citrulline (L-Cit) has been shown to protect mice from the development of NAFLD. Here, we aimed to further assess if L-Cit also attenuates the progression of a pre-existing diet-induced NAFLD and to determine molecular mechanisms involved. Female C57BL/6J mice were either fed a liquid fat-, fructose- and cholesterol-rich diet (FFC) or control diet (C) for 8 weeks to induce early stages of NASH followed by 5 more weeks with either FFC-feeding +/- 2.5 g L-Cit/kg bw or C-feeding. In addition, female C57BL/6J mice were either pair-fed a FFC +/- 2.5 g L-Cit/kg bw +/- 0.01 g/kg bw i.p. N(ω)-hydroxy-nor-l-arginine (NOHA) or C diet for 8 weeks. The protective effects of supplementing L-Cit on the progression of a pre-existing NAFLD were associated with an attenuation of 1) the increased translocation of bacterial endotoxin and 2) the loss of tight junction proteins as well as 3) arginase activity in small intestinal tissue, while no marked changes in intestinal microbiota composition were prevalent in small intestine. Treatment of mice with the arginase inhibitor NOHA abolished the protective effects of L-Cit on diet-induced NAFLD. Our results suggest that the protective effects of L-Cit on the development and progression of NAFLD are related to alterations of intestinal arginase activity and intestinal permeability. l-citrulline diminished progression of non-alcoholic fatty liver disease (NAFLD). l-citrulline protects from fructose-induced small intestinal barrier dysfunction. NASH development is associated with a loss of arginase activity in small intestine. l-citrulline improves intestinal arginase activity in diet-induced NAFLD. Arginase inhibitor attenuates effects of l-citrulline on NAFLD development.
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Shatanawi A, Momani MS, Al-Aqtash R, Hamdan MH, Gharaibeh MN. L-Citrulline Supplementation Increases Plasma Nitric Oxide Levels and Reduces Arginase Activity in Patients With Type 2 Diabetes. Front Pharmacol 2020; 11:584669. [PMID: 33414716 PMCID: PMC7783447 DOI: 10.3389/fphar.2020.584669] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is becoming a major contributor to cardiovascular disease. One of the early signs of T2DM associated cardiovascular events is the development of vascular dysfunction. This dysfunction has been implicated in increasing the morbidity and mortality of T2DM patients. One of the important characteristics of vascular dysfunction is the impaired ability of endothelial cells to produce nitric oxide (NO). Additionally, decreases in the availability of NO is also a major contributor of this pathology. NO is produced by the activity of endothelial NO synthase (eNOS) on its substrate, L-arginine. Reduced availability of L-arginine to eNOS has been implicated in vascular dysfunction in diabetes. Arginase, which metabolizes L-arginine to urea and ornithine, competes directly with NOS for L-arginine. Hence, increases in arginase activity can decrease arginine levels, reducing its availability to eNOS and decreasing NO production. Diabetes has been linked to elevated arginase and associated vascular endothelial dysfunction. We aimed to determine levels of plasma NO and arginase activity in (T2DM) patients and the effects of L-citrulline supplementation, a natural arginase inhibitor, on inhibiting arginase activity in these patients. Levels of arginase correlated with HbA1c levels in diabetic patients. Twenty-five patients received L-citrulline supplements (2000 mg/day) for 1 month. Arginase activity decreased by 21% in T2DM patients after taking L-citrulline supplements. Additionally, plasma NO levels increased by 38%. There was a modest improvement on H1Ac levels in these patients, though not statistically significant. The effect of L-citrulline on arginase activity was also studied in bovine aortic endothelial cells (BAECs) grown in high glucose (HG) conditions. HG (25 mM, 72 h) caused a 2-fold increase in arginase activity in BAECs and decreased NO production by 30%. L-citrulline (2.5 mM) completely prevented the increase in arginase activity and restored NO production levels. These data indicate that L-citrulline can have therapeutic benefits in diabetic patients through increasing NO levels and thus maintaining vascular function possibly through an arginase inhibition related pathway.
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Affiliation(s)
- Alia Shatanawi
- Department of Pharmacology, School of Medicine, The University of Jordan, Amman, Jordan
| | - Munther S Momani
- Department of Internal Medicine, School of Medicine, The University of Jordan, Amman, Jordan
| | - Ruaa Al-Aqtash
- Department of Pharmacology, School of Medicine, The University of Jordan, Amman, Jordan
| | - Mohammad H Hamdan
- Department of Pharmacology, School of Medicine, The University of Jordan, Amman, Jordan.,Department of Neurosurgery, Saarland University Hospital, Homburg, Germany
| | - Munir N Gharaibeh
- Department of Pharmacology, School of Medicine, The University of Jordan, Amman, Jordan
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Gyawali A, Kim MH, Kang YS. A novel organic cation transporter involved in paeonol transport across the inner blood-retinal barrier and changes in uptake in high glucose conditions. Exp Eye Res 2020; 202:108387. [PMID: 33301773 DOI: 10.1016/j.exer.2020.108387] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 11/06/2020] [Accepted: 12/01/2020] [Indexed: 12/29/2022]
Abstract
Paeonol exerts various pharmacological effects owing to its antiangiogenic, antioxidant, and antidiabetic activities. We aimed to investigate the transport mechanism of paeonol across the inner blood-retinal barrier both in vitro and in vivo. The carotid artery single injection method was used to investigate the retina uptake index of paeonol. The retina uptake index (RUI) value of [³H]paeonol was dependent on both concentration and pH. This value decreased significantly in the presence of imperatorin, tramadol, and pyrilamine when compared to the control. However, para-aminohippuric acid, choline, and taurine had no effect on the RUI value. Conditionally immortalized rat retina capillary endothelial cells (TR-iBRB cell lines) were used as an in vitro model of the inner blood-retinal barrier (iBRB). The uptake of [³H]paeonol by the TR-iBRB cell lines was found to be time-, concentration-, and pH-dependent. However, the uptake was unaffected by the absence of sodium or by membrane potential disruption. Moreover, in vitro structural analog studies revealed that [³H]paeonol uptake was inhibited in the presence of organic cationic compounds including imperatorin, clonidine and tramadol. This is consistent with the results obtained in vivo. In addition, transfections with OCTN1, 2 or plasma membrane monoamine transporter (PMAT) small interfering RNA did not affect paeonol uptake in TR-iBRB cell lines. Upon pre-incubation of these cell lines with high glucose (HG) media, [3H]paeonol uptake decreased and mRNA expression levels of angiogenetic factors, such as hypoxia inducible factor-1 (HIF-1) and vascular endothelial growth factor (VEGF) increased. However, after the pretreatment of unlabeled paeonol in HG conditions, the mRNA levels of VEGF and HIF-1 were comparatively reduced, and the [3H]paeonol uptake rate was restored. After being exposed to inflammatory conditions induced by glutamate, TNF-α, and LPS, paeonol and propranolol pretreatment significantly increased the uptake of both [3H]paeonol and [3H]propranolol in TR-iBRB cell lines compared to their respective controls. Our results demonstrate that the transport of paeonol to the retina across the iBRB may involve the proton-coupled organic cation antiporter system, and the uptake of paeonol is changed by HG conditions.
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Affiliation(s)
- Asmita Gyawali
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women's University, Chungpa-dong 2-ga, Yongsan-gu, Seoul, 140-742, Republic of Korea
| | - Myung-Hee Kim
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women's University, Chungpa-dong 2-ga, Yongsan-gu, Seoul, 140-742, Republic of Korea
| | - Young-Sook Kang
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women's University, Chungpa-dong 2-ga, Yongsan-gu, Seoul, 140-742, Republic of Korea.
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11
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Eyob W, George AK, Homme RP, Stanisic D, Sandhu H, Tyagi SC, Singh M. Regulation of the parental gene GRM4 by circGrm4 RNA transcript and glutamate-mediated neurovascular toxicity in eyes. Mol Cell Biochem 2020; 476:663-673. [PMID: 33074445 DOI: 10.1007/s11010-020-03934-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/07/2020] [Indexed: 01/30/2023]
Abstract
Epigenetic memory plays crucial roles in gene regulation. It not only modulates the expression of specific genes but also has ripple effects on transcription as well as translation of other genes. Very often an alteration in expression occurs either via methylation or demethylation. In this context, "1-carbon metabolism" assumes a special significance since its dysregulation by higher levels of homocysteine; Hcy (known as hyperhomocysteinemia; HHcy), a byproduct of "1-Carbon Metabolism" during methionine biosynthesis leads to serious implications in cardiovascular, renal, cerebrovascular systems, and a host of other conditions. Currently, the circular RNAs (circRNAs) generated via non-canonical back-splicing events from the pre-mRNA molecules are at the center stage for their essential roles in diseases via their epigenetic manifestations. We recently identified a circular RNA transcript (circGRM4) that is significantly upregulated in the eye of cystathionine β-synthase-deficient mice. We also discovered a concurrent over-expression of the mGLUR4 receptor in the eyes of these mice. In brief, circGRM4 is selectively transcribed from its parental mGLUR4 receptor gene (GRM4) functions as a "molecular-sponge" for the miRNAs and results into excessive turnover of the mGLUR4 receptor in the eye in response to extremely high circulating glutamate concentration. We opine that this epigenetic manifestation potentially predisposes HHcy people to retinovascular malfunctioning.
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Affiliation(s)
- Wintana Eyob
- College of Arts and Sciences, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH, 44106, USA
| | - Akash K George
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Rubens P Homme
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Dragana Stanisic
- Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Harpal Sandhu
- Department of Ophthalmology and Visual Sciences and Kentucky Lions Eye Center, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Suresh C Tyagi
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Mahavir Singh
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
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12
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Bicker J, Alves G, Fonseca C, Falcão A, Fortuna A. Repairing blood-CNS barriers: Future therapeutic approaches for neuropsychiatric disorders. Pharmacol Res 2020; 162:105226. [PMID: 33007420 DOI: 10.1016/j.phrs.2020.105226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 12/19/2022]
Abstract
Central nervous system (CNS) drug development faces significant difficulties that translate into high rates of failure and lack of innovation. The pathophysiology of neurological and psychiatric disorders often results in the breakdown of blood-CNS barriers, disturbing the CNS microenvironment and worsening disease progression. Therefore, restoring the integrity of blood-CNS barriers may have a beneficial influence in several CNS disorders and improve treatment outcomes. In this review, pathways that may be modulated to protect blood-CNS barriers from neuroinflammatory and oxidative insults are featured. First, the participation of the brain endothelium and glial cells in disruption processes is discussed. Then, the relevance of regulatory systems is analysed, specifically the hypothalamic-pituitary axis, the renin-angiotensin system, sleep and circadian rhythms, and glutamate neurotransmission. Lastly, compounds of endogenous and exogenous origin that are known to mediate the repair of blood-CNS barriers are presented. We believe that enhancing the protection of blood-CNS barriers is a promising therapeutic strategy to pursue in the future.
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Affiliation(s)
- Joana Bicker
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal; University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal.
| | - Gilberto Alves
- CICS-UBI, Health Sciences Research Center, University of Beira Interior, Covilhã, Portugal
| | - Carla Fonseca
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal
| | - Amílcar Falcão
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal; University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal
| | - Ana Fortuna
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal; University of Coimbra, Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra, Portugal
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13
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Riggle BA, Miller LH, Pierce SK. Desperately Seeking Therapies for Cerebral Malaria. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 204:327-334. [PMID: 31907275 PMCID: PMC6951433 DOI: 10.4049/jimmunol.1900829] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/10/2019] [Indexed: 02/07/2023]
Abstract
Malaria is a deadly infectious disease caused by parasites of the Plasmodium spp. that takes an estimated 435,000 lives each year, primarily among young African children. For most children, malaria is a febrile illness that resolves with time, but in ∼1% of cases, for reasons we do not understand, malaria becomes severe and life threatening. Cerebral malaria (CM) is the most common form of severe malaria, accounting for the vast majority of childhood deaths from malaria despite highly effective antiparasite chemotherapy. Thus, CM is one of the most prevalent lethal brain diseases, and one for which we have no effective therapy. CM is, in part, an immune-mediated disease, and to fully understand CM, it is essential to appreciate the complex relationship between the malarial parasite and the human immune system. In this study, we provide a primer on malaria for immunologists and, in this context, review progress identifying targets for therapeutic intervention.
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Affiliation(s)
- Brittany A Riggle
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852; and
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - Susan K Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852; and
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14
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Eshreif A, Al Batran R, Jamieson KL, Darwesh AM, Gopal K, Greenwell AA, Zlobine I, Aburasayn H, Eaton F, Mulvihill EE, Campbell JE, Seubert JM, Ussher JR. l-Citrulline supplementation improves glucose and exercise tolerance in obese male mice. Exp Physiol 2020; 105:270-281. [PMID: 31802553 DOI: 10.1113/ep088109] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 12/03/2019] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the central question of the study? Does the action of l-citrulline, which has been shown to augment performance in animals and athletes, possibly via increasing mitochondrial function, translate to obese animals, and does this improve glycaemia? What is the main finding and its importance? Chronic supplementation with l-citrulline improves not only exercise capacity, but also glycaemia in obese mice, which would be beneficial as obese individuals are at increased risk for type 2 diabetes. However, l-citrulline supplementation also caused a mild impairment in insulin signalling and insulin tolerance in obese mice. ABSTRACT: l-Citrulline is an organic α-amino acid that has been shown to have a number of salutary actions on whole-body physiology, including reducing muscle wasting and augmenting exercise and muscle performance. The latter has been suggested to arise from elevations in mitochondrial function. Because enhancing mitochondrial function has been proposed as a novel strategy to mitigate insulin resistance, our goal was to determine whether supplementation with l-citrulline could also improve glycaemia in an experimental mouse model of obesity. We hypothesized that l-citrulline treatment would improve glycaemia in obese mice, and this would be associated with elevations in skeletal muscle mitochondrial function. Ten-week-old C57BL/6J mice were fed either a low-fat (10% kcal from lard) or a high-fat (60% kcal from lard) diet, while receiving drinking water supplemented with either vehicle or l-citrulline (0.6 g l-1 ) for 15 weeks. Glucose homeostasis was assessed via glucose/insulin tolerance testing, while in vivo metabolism was assessed via indirect calorimetry, and forced exercise treadmill testing was utilized to assess endurance. As expected, obese mice supplemented with l-citrulline exhibited an increase in exercise capacity, which was associated with an improvement in glucose tolerance. Consistent with augmented mitochondrial function, we observed an increase in whole body oxygen consumption rates in obese mice supplemented with l-citrulline. Surprisingly, l-citrulline supplementation worsened insulin tolerance and reduced insulin signalling in obese mice. Taken together, although l-citrulline supplementation improves both glucose tolerance and exercise capacity in obese mice, caution must be applied with its broad use as a nutraceutical due to a potential deterioration of insulin sensitivity.
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Affiliation(s)
- Amina Eshreif
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Rami Al Batran
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - K Lockhart Jamieson
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Ahmed M Darwesh
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Keshav Gopal
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Amanda A Greenwell
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Igor Zlobine
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Hanin Aburasayn
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Farah Eaton
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Erin E Mulvihill
- Department of Biochemistry, Microbiology & Immunology, University of Ottawa, Ottawa, ON, Canada.,University of Ottawa Heart Institute, University of Ottawa, Ottawa, ON, Canada
| | | | - John M Seubert
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - John R Ussher
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
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15
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Krystofova J, Pathipati P, Russ J, Sheldon A, Ferriero D. The Arginase Pathway in Neonatal Brain Hypoxia-Ischemia. Dev Neurosci 2019; 40:437-450. [PMID: 30995639 PMCID: PMC6784534 DOI: 10.1159/000496467] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/20/2018] [Indexed: 12/11/2022] Open
Abstract
Brain damage after hypoxia-ischemia (HI) occurs in an age-dependent manner. Neuroprotective strategies assumed to be effective in adults might have deleterious effects in the immature brain. In order to create effective therapies, the complex pathophysiology of HI in the developing brain requires exploring new mechanisms. Critical determinants of neuronal survival after HI are the extent of vascular dysfunction, inflammation, and oxidative stress, followed later by tissue repair. The key enzyme of these processes in the human body is arginase (ARG) that acts via the bioavailability of nitric oxide, and the synthesis of polyamines and proline. ARG is expressed throughout the brain in different cells. However, little is known about the effect of ARG in pathophysiological states of the brain, especially hypoxia-ischemia. Here, we summarize the role of ARG during neurodevelopment as well as in various brain pathologies.
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Affiliation(s)
- Jana Krystofova
- Department of Pediatrics, University of California San Francisco, San Francisco, California, USA,
| | - Praneeti Pathipati
- Department of Pediatrics, University of California San Francisco, San Francisco, California, USA
| | - Jeffrey Russ
- Department of Pediatrics, University of California San Francisco, San Francisco, California, USA
| | - Ann Sheldon
- Department of Pediatrics, University of California San Francisco, San Francisco, California, USA
| | - Donna Ferriero
- Department of Pediatrics, University of California San Francisco, San Francisco, California, USA
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16
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MRI demonstrates glutamine antagonist-mediated reversal of cerebral malaria pathology in mice. Proc Natl Acad Sci U S A 2018; 115:E12024-E12033. [PMID: 30514812 DOI: 10.1073/pnas.1812909115] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The deadliest complication of Plasmodium falciparum infection is cerebral malaria (CM), with a case fatality rate of 15 to 25% in African children despite effective antimalarial chemotherapy. No adjunctive treatments are yet available for this devastating disease. We previously reported that the glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON) rescued mice from experimental CM (ECM) when administered late in the infection, a time by which mice had already suffered blood-brain barrier (BBB) dysfunction, brain swelling, and hemorrhaging. Herein, we used longitudinal MR imaging to visualize brain pathology in ECM and the impact of a new DON prodrug, JHU-083, on disease progression in mice. We demonstrate in vivo the reversal of disease markers in symptomatic, infected mice following treatment, including the resolution of edema and BBB disruption, findings usually associated with a fatal outcome in children and adults with CM. Our results support the premise that JHU-083 is a potential adjunctive treatment that could rescue children and adults from fatal CM.
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