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Chowdari Gurram P, Satarker S, Nampoothiri M. Recent advances in the molecular signaling pathways of Substance P in Alzheimer's disease: Link to neuroinflammation associated with toll-like receptors. Biochem Biophys Res Commun 2024; 733:150597. [PMID: 39197195 DOI: 10.1016/j.bbrc.2024.150597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Revised: 08/20/2024] [Accepted: 08/22/2024] [Indexed: 09/01/2024]
Abstract
A significant quantity of substance P (SP) and its receptor, the neurokinin 1 (NK1) receptors are found in the brain. SP is a neuropeptide distributed in the central nervous system and functions as a neurotransmitter, neuromodulator, and neurotrophic factor. The concentrations of SP in the brain and cerebrospinal fluid fluctuate in individuals with Alzheimer's disease (AD). SP is an endogenous ligand for NK1 receptor, enhancing the expression of toll-like receptors (TLR) and vice versa. So, both pathways are interconnected, where activation of one pathway activates the second pathway. Researchers have observed the interaction of TLR with SP in the pathophysiology of AD. Thus, this review discusses various TLRs involved in regulating amyloid processing and its interaction with SP in AD. Further, in AD pathology, SP can regulate the non-amyloidogenic pathway. Recent studies have also demonstrated the capacity of SP in regulating voltage-gated potassium channel currents, emphasizing SP's neuroprotective ability. Therefore, we corroborate the findings linking the SP, NK1R, and TLRs in AD.
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Affiliation(s)
- Prasada Chowdari Gurram
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, 576104, India; KL College of Pharmacy, Koneru Lakshmaiah Education Foundation, Green Fields, Vaddeswaram, A.P, 522302, India
| | - Sairaj Satarker
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Madhavan Nampoothiri
- Department of Pharmacology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, 576104, India.
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Kriska T, Natarajan J, Herrnreiter A, Park SK, Pfister SL, Thomas MJ, Widiapradja A, Levick SP, Campbell WB. Cellular metabolism of substance P produces neurokinin-1 receptor peptide agonists with diminished cyclic AMP signaling. Am J Physiol Cell Physiol 2024; 327:C151-C167. [PMID: 38798270 PMCID: PMC11371325 DOI: 10.1152/ajpcell.00103.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 05/01/2024] [Accepted: 05/17/2024] [Indexed: 05/29/2024]
Abstract
Substance P (SP) is released from sensory nerves in the arteries and heart. It activates neurokinin-1 receptors (NK1Rs) causing vasodilation, immune modulation, and adverse cardiac remodeling. The hypothesis was tested: SP and SP metabolites activate different second messenger signaling pathways. Macrophages, endothelial cells, and fibroblasts metabolized SP to N- and C-terminal metabolites to varying extents. SP 5-11 was the most abundant metabolite followed by SP 1-4, SP 7-11, SP 6-11, SP 3-11, and SP 8-11. In NK1R-expressing human embryonic kidney 293 (HEK293) cells, SP and some C-terminal SP metabolites stimulate the NK1R, promoting the dissociation of several Gα proteins, including Gαs and Gαq from their βγ subunits. SP increases intracellular calcium concentrations ([Ca]i) and cyclic 3',5'-adenosine monophosphate (cAMP) accumulation with similar -log EC50 values of 8.5 ± 0.3 and 7.8 ± 0.1 M, respectively. N-terminal metabolism of SP by up to five amino acids and C-terminal deamidation of SP produce peptides that retain activity to increase [Ca]i but not to increase cAMP. C-terminal metabolism results in the loss of both activities. Thus, [Ca]i and cAMP signaling are differentially affected by SP metabolism. To assess the role of N-terminal metabolism, SP and SP 6-11 were compared with cAMP-mediated activities in NK1R-expressing 3T3 fibroblasts. SP inhibits nuclear factor κB (NF-κB) activity, cell proliferation, and wound healing and stimulates collagen production. SP 6-11 had little or no activity. Cyclooxygenase-2 (COX-2) expression is increased by SP but not by SP 6-11. Thus, metabolism may select the cellular response to SP by inhibiting or redirecting the second messenger signaling pathway activated by the NK1R.NEW & NOTEWORTHY Endothelial cells, macrophages, and fibroblasts metabolize substance P (SP) to N- and C-terminal metabolites with SP 5-11 as the most abundant metabolite. SP activates neurokinin-1 receptors to increase intracellular calcium and cyclic AMP. In contrast, SP metabolites of N-terminal metabolism and C-terminal deamidation retain the ability to increase calcium but lose the ability to increase cyclic AMP. These new insights indicate that the metabolism of SP directs cellular functions by regulating specific signaling pathways.
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Affiliation(s)
- Tamas Kriska
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Jayashree Natarajan
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Anja Herrnreiter
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Sang-Kyu Park
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Sandra L Pfister
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michael J Thomas
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Alexander Widiapradja
- Robert C. Byrd Health Sciences Center, Department of Physiology and Pharmacology, West Virginia University, Morgantown, Virginia, United States
| | - Scott P Levick
- Robert C. Byrd Health Sciences Center, Department of Physiology and Pharmacology, West Virginia University, Morgantown, Virginia, United States
| | - William B Campbell
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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Schreiber U, Engl C, Bayer M, König S. Labeled substance P as a neuropeptide reporter substance for enzyme activity. J Pharm Biomed Anal 2020; 178:112953. [PMID: 31718985 DOI: 10.1016/j.jpba.2019.112953] [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: 08/08/2019] [Revised: 10/18/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
Recently, we developed a bradykinin reporter assay and demonstrated the differing protease activity in Complex Regional Pain Syndrome patients vs. controls. In order to further characterize CRPS pathophysiology, the neuropeptide substance P was evaluated as possible reporter substance, here. It was labeled with a chromophore at the lysine residue and generated two major fragments following incubation with serum (amino acid residues 3-8 and 3-11) which were reproducibly separated by thin-layer chromatography. Dabsylated substance P was shown to be a substrate of angiotensin-converting enzyme. The combination of both bradykinin and substance P reporter substances with specific enzyme inhibitors will shed more light on biochemical pathways in inflammatory processes and pain. Comparative clinical studies are now needed to define the application range of both assays in more detail.
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Affiliation(s)
- Ulrich Schreiber
- Core Unit Proteomics, Interdisciplinary Center for Clinical Research, Medical Faculty, University of Münster, Germany
| | - Christian Engl
- Core Unit Proteomics, Interdisciplinary Center for Clinical Research, Medical Faculty, University of Münster, Germany
| | - Malte Bayer
- Core Unit Proteomics, Interdisciplinary Center for Clinical Research, Medical Faculty, University of Münster, Germany
| | - Simone König
- Core Unit Proteomics, Interdisciplinary Center for Clinical Research, Medical Faculty, University of Münster, Germany.
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Clayson MS, Devereaux MEM, Pamenter ME. Neurokinin-1 receptor activation is sufficient to restore the hypercapnic ventilatory response in the Substance P-deficient naked mole-rat. Am J Physiol Regul Integr Comp Physiol 2020; 318:R712-R721. [PMID: 31967860 DOI: 10.1152/ajpregu.00251.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Naked mole-rats (NMRs) live in large colonies within densely populated underground burrows. Their collective respiration generates significant metabolic carbon dioxide (CO2) that diffuses slowly out of the burrow network, creating a hypercapnic environment. Currently, the physiological mechanisms that underlie the ability of NMRs to tolerate environmental hypercapnia are largely unknown. To address this, we used whole-body plethysmography and respirometry to elucidate the hypercapnic ventilatory and metabolic responses of awake, freely behaving NMRs to 0%-10% CO2. We found that NMRs have a blunted hypercapnic ventilatory response (HCVR): ventilation increased only in 10% CO2. Conversely, metabolism was unaffected by hypercapnia. NMRs are insensitive to cutaneous acid-based pain caused by modified substance P (SP)-mediated peripheral neurotransmission, and SP is also an important neuromodulator of ventilation. Therefore, we re-evaluated physiological responses to hypercapnia in NMRs after an intraperitoneal injection of exogenous substance P (2 mg/kg) or a long-lived isoform of substance P {[pGlu5-MePhe8-MeGly9]SP(5-11), DiMe-C7; 40-400 μg/kg}. We found that both drugs restored hypercapnia sensitivity and unmasked an HCVR in animals breathing 2%-10% CO2. Taken together, our findings indicate that NMRs are remarkably tolerant of hypercapnic environments and have a blunted HCVR; however, the signaling network architecture required for a "normal" HCVR is retained but endogenously inactive. This muting of chemosensitivity likely suits the ecophysiology of this species, which presumably experiences hypercapnia regularly in their underground niche.
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Affiliation(s)
- Maxwell S Clayson
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.,University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada
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Substance P receptor in the rat indusium griseum during postnatal development. Neurosci Res 2018; 130:23-38. [DOI: 10.1016/j.neures.2017.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/09/2017] [Accepted: 08/18/2017] [Indexed: 11/21/2022]
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Lyczko M, Pruszynski M, Majkowska-Pilip A, Lyczko K, Was B, Meczynska-Wielgosz S, Kruszewski M, Szkliniarz K, Jastrzebski J, Stolarz A, Bilewicz A. 211At labeled substance P (5-11) as potential radiopharmaceutical for glioma treatment. Nucl Med Biol 2017; 53:1-8. [PMID: 28683361 DOI: 10.1016/j.nucmedbio.2017.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 04/18/2017] [Accepted: 05/21/2017] [Indexed: 02/03/2023]
Abstract
INTRODUCTION The purposes of the present work were to label substance P (5-11) with 211At using a rhodium(III) complex with a bifunctional ligand-2-(1,5,9,13-tetrathiacyclohexadecan-3-yloxy)acetic acid ([16aneS4]-COOH) and to assess the in vitro stability and toxicity of the obtained radiobioconjugate. METHODS Two approaches were evaluated to obtain 131I/211At-Rh[16aneS4]-SP5-11 radiobioconjugates, based on 2-step and 1-step syntheses. In the first method 131I/211At-Rh[16aneS4]-COOH complexes were obtained that required further coupling to a biomolecule. In the second approach, the bioconjugate [16aneS4]-SP5-11 was synthesized and further labeled with 131I and 211At through the utilization of a Rh(III) metal cation bridge. The synthesized compounds were analyzed by HPLC, TLC and paper electrophoresis. RESULTS The 131I/211At-Rh[16aneS4]-COOH complexes were obtained in high yield and possessed good stability in PBS and CSF. Preliminary studies on coupling of 131I-Rh[16aneS4]-COOH to substance P (5-11) in 2-step synthesis showed that this procedure was too long with respect to 211At half-life, prompting us to improve it by finally using a 1-step synthesis. This strategy not only shortened the labeling time, but also increased final yield of 131I/211At-Rh[16aneS4]-SP5-11 radiobioconjugates. The stability of both compounds in PBS and CSF was high. Toxicity studies with the 211At-Rh[16aneS4]-SP5-11 demonstrated that radiobioconjugate significantly reduced T98G cell viability in a dose dependent manner reaching 20% of survival at the highest radioactivity 1200kBq/mL. CONCLUSIONS The radiobioconjugate 211At-Rh[16aneS4]-SP5-11 revealed its potential in killing glioma T98G cells during in vitro studies; therefore further animal studies to are required to determine its in vivo stability and treatment potential in normal and xenografted mice.
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Affiliation(s)
- Monika Lyczko
- Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Poland.
| | - Marek Pruszynski
- Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Poland
| | - Agnieszka Majkowska-Pilip
- Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Poland
| | - Krzysztof Lyczko
- Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Poland
| | - Bogdan Was
- Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Cracow, Poland
| | - Sylwia Meczynska-Wielgosz
- Centre For Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Poland
| | - Marcin Kruszewski
- Centre For Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Poland; Faculty of Medicine, University of Information Technology and Management in Rzeszów, 35-225 Rzeszów, Poland; Department of Molecular Biology and Translational Research, Institute of Rural Health, 20-090 Lublin, Poland
| | | | | | - Anna Stolarz
- Heavy Ion Laboratory, University of Warsaw, 02-093 Warsaw, Poland
| | - Aleksander Bilewicz
- Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Poland
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Wagner L, Kaestner F, Wolf R, Stiller H, Heiser U, Manhart S, Hoffmann T, Rahfeld JU, Demuth HU, Rothermundt M, von Hörsten S. Identifying neuropeptide Y (NPY) as the main stress-related substrate of dipeptidyl peptidase 4 (DPP4) in blood circulation. Neuropeptides 2016; 57:21-34. [PMID: 26988064 DOI: 10.1016/j.npep.2016.02.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/21/2016] [Accepted: 02/25/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Dipeptidyl peptidase 4 (DPP4; EC 3.4.14.5; CD26) is a membrane-bound or shedded serine protease that hydrolyzes dipeptides from the N-terminus of peptides with either proline or alanine at the penultimate position. Substrates of DPP4 include several stress-related neuropeptides implicated in anxiety, depression and schizophrenia. A decline of DPP4-like activity has been reported in sera from depressed patient, but not fully characterized regarding DPP4-like enzymes, therapeutic interventions and protein. METHODS Sera from 16 melancholic- and 16 non-melancholic-depressed patients were evaluated for DPP4-like activities and the concentration of soluble DPP4 protein before and after treatment by anti-depressive therapies. Post-translational modification of DPP4-isoforms and degradation of NPY, Peptide YY (PYY), Galanin-like peptide (GALP), Orexin B (OrxB), OrxA, pituitary adenylate cyclase-activating polypeptide (PACAP) and substance P (SP) were studied in serum and in ex vivo human blood. N-terminal truncation of biotinylated NPY by endothelial membrane-bound DPP4 versus soluble DPP4 was determined in rat brain perfusates and spiked sera. RESULTS Lower DPP4 activities in depressed patients were reversed by anti-depressive treatment. In sera, DPP4 contributed to more than 90% of the overall DPP4-like activity and correlated with its protein concentration. NPY displayed equal degradation in serum and blood, and was equally truncated by serum and endothelial DPP4. In addition, GALP and rat OrxB were identified as novel substrates of DPP4. CONCLUSION NPY is the best DPP4-substrate in blood, being truncated by soluble and membrane DPP4, respectively. The decline of soluble DPP4 in acute depression could be reversed upon anti-depressive treatment. Peptidases from three functional compartments regulate the bioactivity of NPY in blood.
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Affiliation(s)
- Leona Wagner
- Deutschsprachige Selbsthilfegruppe für Alkaptonurie (DSAKU) e,V., Stuttgart, Germany; Probiodrug AG, Halle, Germany; Universitätsklinikum Erlangen, Department of Experimental Therapy, Erlangen, Germany.
| | - Florian Kaestner
- Department of Psychiatry, University of Münster, Münster, Germany
| | - Raik Wolf
- Center for Clinical Chemistry, Microbiology and Transfusion, Klinikum St. Georg gGmbH, Germany; Probiodrug AG, Halle, Germany
| | | | | | | | - Torsten Hoffmann
- Center for Clinical Chemistry, Microbiology and Transfusion, Klinikum St. Georg gGmbH, Germany
| | - Jens-Ulrich Rahfeld
- Fraunhofer-Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, 06120 Halle, Germany
| | - Hans-Ulrich Demuth
- Fraunhofer-Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, 06120 Halle, Germany
| | - Matthias Rothermundt
- Department of Psychiatry, University of Münster, Münster, Germany; St. Rochus-Hospital Telgte, 48291 Telgte, Germany
| | - Stephan von Hörsten
- Universitätsklinikum Erlangen, Department of Experimental Therapy, Erlangen, Germany.
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Mosher RA, Coetzee JF, Allen PS, Havel JA, Griffith GR, Wang C. Effects of sample handling methods on substance P concentrations and immunoreactivity in bovine blood samples. Am J Vet Res 2014; 75:109-16. [DOI: 10.2460/ajvr.75.2.109] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Pailleux F, Vachon P, Lemoine J, Beaudry F. Targeted liquid chromatography quadrupole ion trap mass spectrometry analysis of tachykinin related peptides reveals significant expression differences in a rat model of neuropathic pain. Neuropeptides 2013; 47:261-71. [PMID: 23490005 DOI: 10.1016/j.npep.2013.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 02/07/2013] [Accepted: 02/14/2013] [Indexed: 12/26/2022]
Abstract
Animal models are widely used to perform basic scientific research in pain. The rodent chronic constriction injury (CCI) model is widely used to study neuropathic pain. Animals were tested prior and after CCI surgery using behavioral tests (von Frey filaments and Hargreaves test) to evaluate pain. The brain and the lumbar enlargement of the spinal cord were collected from neuropathic and normal animals. Tachykinin related peptides were analyzed by high performance liquid chromatography quadrupole ion trap mass spectrometry. Our results reveal that the β-tachykinin₅₈₋₇₁, SP and SP₃₋₁₁ up-regulation are closely related to pain behavior. The spinal β-tachykinin₅₈₋₇₁, SP and SP₃₋₁₁ concentrations were significantly up-regulated in neuropathic animals compared with normal animals (p<0.001; p<0.001 and p<0.05, respectively). In contrast, the spinal SP5₅₋₁₁ concentration in neuropathic animals revealed a significant down-regulation compared with normal animals (p<0.05). The brain β-tachykinin₅₈₋₇₁ and SP concentrations were significantly up-regulated (p<0.05 and p<0.001, respectively). Interestingly, no significant concentration differences were observed in the spinal cord and brain for NKA, β-tachykinin₅₈₋₇₁, SP₁₋₇ and SP₆₋₁₁ (p>0.05). The β-tachykinin₅₈₋₇₁, SP and C-terminal SP metabolites could potentially serve as biomarkers in early drug discovery.
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Affiliation(s)
- Floriane Pailleux
- Groupe de Recherche en Pharmacologie Animal du Québec-GREPAQ, Département de Biomédecine Vétérinaire, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Québec, Canada
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Pailleux F, Lemoine J, Beaudry F. Investigation of the metabolic biotransformation of substance P in liver microsomes by liquid chromatography quadrupole ion trap mass spectrometry. Biomed Chromatogr 2012; 27:39-47. [DOI: 10.1002/bmc.2746] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 03/14/2012] [Accepted: 03/14/2012] [Indexed: 11/11/2022]
Affiliation(s)
| | - Jérôme Lemoine
- UMR 5280 CNRS Université de Lyon 1, Institut des Sciences Analytiques; Université de Lyon; 69622; Villeurbanne cedex; France
| | - Francis Beaudry
- Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Département de biomedicine vétérinaire, Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe; Québec; Canada
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Kuhnline Sloan CD, Nandi P, Linz TH, Aldrich JV, Audus KL, Lunte SM. Analytical and biological methods for probing the blood-brain barrier. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2012; 5:505-31. [PMID: 22708905 PMCID: PMC3744104 DOI: 10.1146/annurev-anchem-062011-143002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The blood-brain barrier (BBB) is an important interface between the peripheral and central nervous systems. It protects the brain against the infiltration of harmful substances and regulates the permeation of beneficial endogenous substances from the blood into the extracellular fluid of the brain. It can also present a major obstacle in the development of drugs that are targeted for the central nervous system. Several methods have been developed to investigate the transport and metabolism of drugs, peptides, and endogenous compounds at the BBB. In vivo methods include intravenous injection, brain perfusion, positron emission tomography, and microdialysis sampling. Researchers have also developed in vitro cell-culture models that can be employed to investigate transport and metabolism at the BBB without the complication of systemic involvement. All these methods require sensitive and selective analytical methods to monitor the transport and metabolism of the compounds of interest at the BBB.
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Perry M, Li Q, Kennedy RT. Review of recent advances in analytical techniques for the determination of neurotransmitters. Anal Chim Acta 2009; 653:1-22. [PMID: 19800472 PMCID: PMC2759352 DOI: 10.1016/j.aca.2009.08.038] [Citation(s) in RCA: 248] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 08/25/2009] [Accepted: 08/27/2009] [Indexed: 12/18/2022]
Abstract
Methods and advances for monitoring neurotransmitters in vivo or for tissue analysis of neurotransmitters over the last five years are reviewed. The review is organized primarily by neurotransmitter type. Transmitter and related compounds may be monitored by either in vivo sampling coupled to analytical methods or implanted sensors. Sampling is primarily performed using microdialysis, but low-flow push-pull perfusion may offer advantages of spatial resolution while minimizing the tissue disruption associated with higher flow rates. Analytical techniques coupled to these sampling methods include liquid chromatography, capillary electrophoresis, enzyme assays, sensors, and mass spectrometry. Methods for the detection of amino acid, monoamine, neuropeptide, acetylcholine, nucleoside, and soluble gas neurotransmitters have been developed and improved upon. Advances in the speed and sensitivity of these methods have enabled improvements in temporal resolution and increased the number of compounds detectable. Similar advances have enabled improved detection at tissue samples, with a substantial emphasis on single cell and other small samples. Sensors provide excellent temporal and spatial resolution for in vivo monitoring. Advances in application to catecholamines, indoleamines, and amino acids have been prominent. Improvements in stability, sensitivity, and selectivity of the sensors have been of paramount interest.
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Affiliation(s)
- Maura Perry
- University of Michigan, Department of Chemistry, 930 N. University, Ann Arbor, MI 48109-1055, USA
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Pottiez G, Flahaut C, Cecchelli R, Karamanos Y. Understanding the blood-brain barrier using gene and protein expression profiling technologies. ACTA ACUST UNITED AC 2009; 62:83-98. [PMID: 19770003 DOI: 10.1016/j.brainresrev.2009.09.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 08/31/2009] [Accepted: 09/12/2009] [Indexed: 12/24/2022]
Abstract
The blood-brain barrier (BBB) contributes to the brain homeostasis by regulating the passage of endogenous and exogenous compounds. This function is in part due to well-known proteins such as tight junction proteins, plasma membrane transporters and metabolic barrier proteins. Over the last decade, genomics and proteomics have emerged as supplementary tools for BBB research. The development of genomic and proteomic technologies has provided several means to extend the BBB knowledge and to investigate additional routes for the bypass of this barrier. These profiling technologies have been used on BBB models to decipher the physiological characteristics and, under stress conditions, to understand the molecular mechanisms of brain diseases. In this review, we will report and discuss the genomic and proteomic studies recently carried out to enhance the understanding of BBB features.
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