1
|
Edman NI, Phal A, Redler RL, Schlichthaerle T, Srivatsan SR, Ehnes DD, Etemadi A, An SJ, Favor A, Li Z, Praetorius F, Gordon M, Vincent T, Marchiano S, Blakely L, Lin C, Yang W, Coventry B, Hicks DR, Cao L, Bethel N, Heine P, Murray A, Gerben S, Carter L, Miranda M, Negahdari B, Lee S, Trapnell C, Zheng Y, Murry CE, Schweppe DK, Freedman BS, Stewart L, Ekiert DC, Schlessinger J, Shendure J, Bhabha G, Ruohola-Baker H, Baker D. Modulation of FGF pathway signaling and vascular differentiation using designed oligomeric assemblies. Cell 2024:S0092-8674(24)00534-8. [PMID: 38861993 DOI: 10.1016/j.cell.2024.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/14/2024] [Accepted: 05/13/2024] [Indexed: 06/13/2024]
Abstract
Many growth factors and cytokines signal by binding to the extracellular domains of their receptors and driving association and transphosphorylation of the receptor intracellular tyrosine kinase domains, initiating downstream signaling cascades. To enable systematic exploration of how receptor valency and geometry affect signaling outcomes, we designed cyclic homo-oligomers with up to 8 subunits using repeat protein building blocks that can be modularly extended. By incorporating a de novo-designed fibroblast growth factor receptor (FGFR)-binding module into these scaffolds, we generated a series of synthetic signaling ligands that exhibit potent valency- and geometry-dependent Ca2+ release and mitogen-activated protein kinase (MAPK) pathway activation. The high specificity of the designed agonists reveals distinct roles for two FGFR splice variants in driving arterial endothelium and perivascular cell fates during early vascular development. Our designed modular assemblies should be broadly useful for unraveling the complexities of signaling in key developmental transitions and for developing future therapeutic applications.
Collapse
Affiliation(s)
- Natasha I Edman
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA; Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA; Medical Scientist Training Program, University of Washington, Seattle, WA 98195, USA
| | - Ashish Phal
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA; Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Rachel L Redler
- Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - Thomas Schlichthaerle
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Sanjay R Srivatsan
- Institute for Protein Design, University of Washington, Seattle, WA 98195, USA; Medical Scientist Training Program, University of Washington, Seattle, WA 98195, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Devon Duron Ehnes
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA
| | - Ali Etemadi
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA; Medical Biotechnology Department, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Seong J An
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Andrew Favor
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Zhe Li
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Florian Praetorius
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Max Gordon
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA
| | - Thomas Vincent
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA; Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Silvia Marchiano
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA
| | - Leslie Blakely
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA
| | - Chuwei Lin
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Wei Yang
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Brian Coventry
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Derrick R Hicks
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Longxing Cao
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Neville Bethel
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Piper Heine
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Analisa Murray
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Stacey Gerben
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Lauren Carter
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Marcos Miranda
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Babak Negahdari
- Medical Biotechnology Department, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Sangwon Lee
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Cole Trapnell
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA; Allen Discovery Center for Cell Lineage Tracing, Seattle, WA 98109, USA
| | - Ying Zheng
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA; Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, Seattle WA 98109, USA
| | - Charles E Murry
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA; Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Center for Cardiovascular Biology, University of Washington, Seattle WA 98109, USA; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA; Department of Medicine/Cardiology, University of Washington, Seattle WA 98195, USA
| | - Devin K Schweppe
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Benjamin S Freedman
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA; Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98109, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA; Kidney Research Institute, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Lance Stewart
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Damian C Ekiert
- Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA; Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Joseph Schlessinger
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA; Allen Discovery Center for Cell Lineage Tracing, Seattle, WA 98109, USA
| | - Gira Bhabha
- Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - Hannele Ruohola-Baker
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA; Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA.
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|
2
|
Zhang Q, Yan X, Han H, Wang Y, Sun J. Pericyte in retinal vascular diseases: A multifunctional regulator and potential therapeutic target. FASEB J 2024; 38:e23679. [PMID: 38780117 DOI: 10.1096/fj.202302624r] [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: 12/19/2023] [Revised: 04/17/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024]
Abstract
Retinal vascular diseases (RVDs), in particular diabetic retinopathy, retinal vein occlusion, and retinopathy of prematurity, are leading contributors to blindness. The pathogenesis of RVD involves vessel dilatation, leakage, and occlusion; however, the specific underlying mechanisms remain unclear. Recent findings have indicated that pericytes (PCs), as critical members of the vascular mural cells, significantly contribute to the progression of RVDs, including detachment from microvessels, alteration of contractile and secretory properties, and excessive production of the extracellular matrix. Moreover, PCs are believed to have mesenchymal stem properties and, therefore, might contribute to regenerative therapy. Here, we review novel ideas concerning PC characteristics and functions in RVDs and discuss potential therapeutic strategies based on PCs, including the targeting of pathological signals and cell-based regenerative treatments.
Collapse
Affiliation(s)
- Quan Zhang
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Air Force Medical University, Xi'an, China
- State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China
| | - Xianchun Yan
- State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China
| | - Hua Han
- State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China
| | - Yusheng Wang
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Jiaxing Sun
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Air Force Medical University, Xi'an, China
- Department of Neurobiology, Air Force Medical University, Xi'an, China
| |
Collapse
|
3
|
Joulia R, Puttur F, Stölting H, Traves WJ, Entwistle LJ, Voitovich A, Garcia Martín M, Al-Sahaf M, Bonner K, Scotney E, Molyneaux PL, Hewitt RJ, Walker SA, Yates L, Saglani S, Lloyd CM. Mast cell activation disrupts interactions between endothelial cells and pericytes during early life allergic asthma. J Clin Invest 2024; 134:e173676. [PMID: 38487999 PMCID: PMC10940085 DOI: 10.1172/jci173676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 01/23/2024] [Indexed: 03/18/2024] Open
Abstract
Allergic asthma generally starts during early life and is linked to substantial tissue remodeling and lung dysfunction. Although angiogenesis is a feature of the disrupted airway, the impact of allergic asthma on the pulmonary microcirculation during early life is unknown. Here, using quantitative imaging in precision-cut lung slices (PCLSs), we report that exposure of neonatal mice to house dust mite (HDM) extract disrupts endothelial cell/pericyte interactions in adventitial areas. Central to the blood vessel structure, the loss of pericyte coverage was driven by mast cell (MC) proteases, such as tryptase, that can induce pericyte retraction and loss of the critical adhesion molecule N-cadherin. Furthermore, spatial transcriptomics of pediatric asthmatic endobronchial biopsies suggests intense vascular stress and remodeling linked with increased expression of MC activation pathways in regions enriched in blood vessels. These data provide previously unappreciated insights into the pathophysiology of allergic asthma with potential long-term vascular defects.
Collapse
Affiliation(s)
- Régis Joulia
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - Franz Puttur
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - Helen Stölting
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - William J. Traves
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - Lewis J. Entwistle
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - Anastasia Voitovich
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - Minerva Garcia Martín
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - May Al-Sahaf
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
- Department of Thoracic Surgery, Hammersmith Hospital, London, UK
| | - Katie Bonner
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
- Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, UK
| | - Elizabeth Scotney
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
- Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, UK
| | - Philip L. Molyneaux
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
- Royal Brompton and Harefield Hospitals, Guy’s and St. Thomas’ NHS Foundation Trust, London, UK
| | - Richard J. Hewitt
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
- Royal Brompton and Harefield Hospitals, Guy’s and St. Thomas’ NHS Foundation Trust, London, UK
| | - Simone A. Walker
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - Laura Yates
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| | - Sejal Saglani
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
- Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, UK
| | - Clare M. Lloyd
- National Heart and Lung Institute (NHLI), Imperial College London, London, United Kingdom (UK)
| |
Collapse
|
4
|
Ikegami K. Circadian rhythm of intraocular pressure. J Physiol Sci 2024; 74:14. [PMID: 38431563 PMCID: PMC10908160 DOI: 10.1186/s12576-024-00905-8] [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: 11/09/2023] [Accepted: 02/04/2024] [Indexed: 03/05/2024]
Abstract
Intraocular pressure (IOP) plays a crucial role in glaucoma development, involving the dynamics of aqueous humor (AH). AH flows in from the ciliary body and exits through the trabecular meshwork (TM). IOP follows a circadian rhythm synchronized with the suprachiasmatic nucleus (SCN), the circadian pacemaker. The SCN resets peripheral clocks through sympathetic nerves or adrenal glucocorticoids (GCs). IOP's circadian rhythm is governed by circadian time signals, sympathetic noradrenaline (NE), and GCs, rather than the local clock. The activity of Na+/K+-ATPase in non-pigmented epithelial cells in the ciliary body can influence the nocturnal increase in IOP by enhancing AH inflow. Conversely, NE, not GCs, can regulate the IOP rhythm by suppressing TM macrophage phagocytosis and AH outflow. The activation of the β1-adrenergic receptor (AR)-mediated EPAC-SHIP1 signal through the ablation of phosphatidylinositol triphosphate may govern phagocytic cup formation. These findings could offer insights for better glaucoma management, such as chronotherapy.
Collapse
Affiliation(s)
- Keisuke Ikegami
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-Ku, Fukuoka, 819-0395, Japan.
| |
Collapse
|
5
|
Li G, Gao J, Ding P, Gao Y. The role of endothelial cell-pericyte interactions in vascularization and diseases. J Adv Res 2024:S2090-1232(24)00029-8. [PMID: 38246244 DOI: 10.1016/j.jare.2024.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
BACKGROUND Endothelial cells (ECs) and pericytes (PCs) are crucial components of the vascular system, with ECs lining the inner layer of blood vessels and PCs surrounding capillaries to regulate blood flow and angiogenesis. Intercellular communication between ECs and PCs is vital for the formation, stability, and function of blood vessels. Various signaling pathways, such as the vascular endothelial growth factor/vascular endothelial growth factor receptor pathway and the platelet-derived growth factor-B/platelet-derived growth factor receptor-β pathway, play roles in communication between ECs and PCs. Dysfunctional communication between these cells is associated with various diseases, including vascular diseases, central nervous system disorders, and certain types of cancers. AIM OF REVIEW This review aimed to explore the diverse roles of ECs and PCs in the formation and reshaping of blood vessels. This review focused on the essential signaling pathways that facilitate communication between these cells and investigated how disruptions in these pathways may contribute to disease. Additionally, the review explored potential therapeutic targets, future research directions, and innovative approaches, such as investigating the impact of EC-PCs in novel systemic diseases, addressing resistance to antiangiogenic drugs, and developing novel antiangiogenic medications to enhance therapeutic efficacy. KEY SCIENTIFIC CONCEPTS OF REVIEW Disordered EC-PC intercellular signaling plays a role in abnormal blood vessel formation, thus contributing to the progression of various diseases and the development of resistance to antiangiogenic drugs. Therefore, studies on EC-PC intercellular interactions have high clinical relevance.
Collapse
Affiliation(s)
- Gan Li
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Institute of Microsurgery on Extremities, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Junjie Gao
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Institute of Microsurgery on Extremities, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Shanghai Sixth People's Hospital Fujian, No. 16, Luoshan Section, Jinguang Road, Luoshan Street, Jinjiang City, Quanzhou, Fujian, China
| | - Peng Ding
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Institute of Microsurgery on Extremities, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.
| | - Youshui Gao
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China; Institute of Microsurgery on Extremities, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.
| |
Collapse
|
6
|
Alarcon-Martinez L, Shiga Y, Villafranca-Baughman D, Cueva Vargas JL, Vidal Paredes IA, Quintero H, Fortune B, Danesh-Meyer H, Di Polo A. Neurovascular dysfunction in glaucoma. Prog Retin Eye Res 2023; 97:101217. [PMID: 37778617 DOI: 10.1016/j.preteyeres.2023.101217] [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: 07/24/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Retinal ganglion cells, the neurons that die in glaucoma, are endowed with a high metabolism requiring optimal provision of oxygen and nutrients to sustain their activity. The timely regulation of blood flow is, therefore, essential to supply firing neurons in active areas with the oxygen and glucose they need for energy. Many glaucoma patients suffer from vascular deficits including reduced blood flow, impaired autoregulation, neurovascular coupling dysfunction, and blood-retina/brain-barrier breakdown. These processes are tightly regulated by a community of cells known as the neurovascular unit comprising neurons, endothelial cells, pericytes, Müller cells, astrocytes, and microglia. In this review, the neurovascular unit takes center stage as we examine the ability of its members to regulate neurovascular interactions and how their function might be altered during glaucomatous stress. Pericytes receive special attention based on recent data demonstrating their key role in the regulation of neurovascular coupling in physiological and pathological conditions. Of particular interest is the discovery and characterization of tunneling nanotubes, thin actin-based conduits that connect distal pericytes, which play essential roles in the complex spatial and temporal distribution of blood within the retinal capillary network. We discuss cellular and molecular mechanisms of neurovascular interactions and their pathophysiological implications, while highlighting opportunities to develop strategies for vascular protection and regeneration to improve functional outcomes in glaucoma.
Collapse
Affiliation(s)
- Luis Alarcon-Martinez
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada; Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
| | - Yukihiro Shiga
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Deborah Villafranca-Baughman
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Jorge L Cueva Vargas
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Isaac A Vidal Paredes
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Heberto Quintero
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Healthy, Portland, OR, USA
| | - Helen Danesh-Meyer
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Adriana Di Polo
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada.
| |
Collapse
|
7
|
Fu J, Liang H, Yuan P, Wei Z, Zhong P. Brain pericyte biology: from physiopathological mechanisms to potential therapeutic applications in ischemic stroke. Front Cell Neurosci 2023; 17:1267785. [PMID: 37780206 PMCID: PMC10536258 DOI: 10.3389/fncel.2023.1267785] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 08/30/2023] [Indexed: 10/03/2023] Open
Abstract
Pericytes play an indispensable role in various organs and biological processes, such as promoting angiogenesis, regulating microvascular blood flow, and participating in immune responses. Therefore, in this review, we will first introduce the discovery and development of pericytes, identification methods and functional characteristics, then focus on brain pericytes, on the one hand, to summarize the functions of brain pericytes under physiological conditions, mainly discussing from the aspects of stem cell characteristics, contractile characteristics and paracrine characteristics; on the other hand, to summarize the role of brain pericytes under pathological conditions, mainly taking ischemic stroke as an example. Finally, we will discuss and analyze the application and development of pericytes as therapeutic targets, providing the research basis and direction for future microvascular diseases, especially ischemic stroke treatment.
Collapse
Affiliation(s)
- Jiaqi Fu
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
- Department of Neurology, Shidong Hospital, Yangpu District, Shanghai, China
| | - Huazheng Liang
- Monash Suzhou Research Institute, Suzhou, Jiangsu, China
| | - Ping Yuan
- Department of Cardio-Pulmonary Circulation, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Zhenyu Wei
- Department of Neurology, Shidong Hospital, Yangpu District, Shanghai, China
| | - Ping Zhong
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
- Department of Neurology, Shidong Hospital, Yangpu District, Shanghai, China
| |
Collapse
|
8
|
Gurler G, Belder N, Beker MC, Sever-Bahcekapili M, Uruk G, Kilic E, Yemisci M. Reduced folate carrier 1 is present in retinal microvessels and crucial for the inner blood retinal barrier integrity. Fluids Barriers CNS 2023; 20:47. [PMID: 37328777 DOI: 10.1186/s12987-023-00442-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 05/18/2023] [Indexed: 06/18/2023] Open
Abstract
BACKGROUND Reduced folate carrier 1 (RFC1; SLC19a1) is the main responsible transporter for the B9 family of vitamins named folates, which are essential for normal tissue growth and development. While folate deficiency resulted in retinal vasculopathy, the expression and the role of RFC1 in blood-retinal barrier (BRB) are not well known. METHODS We used whole mount retinas and trypsin digested microvessel samples of adult mice. To knockdown RFC1, we delivered RFC1-targeted short interfering RNA (RFC1-siRNA) intravitreally; while, to upregulate RFC1 we delivered lentiviral vector overexpressing RFC1. Retinal ischemia was induced 1-h by applying FeCl3 to central retinal artery. We used RT-qPCR and Western blotting to determine RFC1. Endothelium (CD31), pericytes (PDGFR-beta, CD13, NG2), tight-junctions (Occludin, Claudin-5 and ZO-1), main basal membrane protein (Collagen-4), endogenous IgG and RFC1 were determined immunohistochemically. RESULTS Our analyses on whole mount retinas and trypsin digested microvessel samples of adult mice revealed the presence of RFC1 in the inner BRB and colocalization with endothelial cells and pericytes. Knocking down RFC1 expression via siRNA delivery resulted in the disintegration of tight junction proteins and collagen-4 in twenty-four hours, which was accompanied by significant endogenous IgG extravasation. This indicated the impairment of BRB integrity after an abrupt RFC1 decrease. Furthermore, lentiviral vector-mediated RFC1 overexpression resulted in increased tight junction proteins and collagen-4, confirming the structural role of RFC1 in the inner BRB. Acute retinal ischemia decreased collagen-4 and occludin levels and led to an increase in RFC1. Besides, the pre-ischemic overexpression of RFC1 partially rescued collagen-4 and occludin levels which would be decreased after ischemia. CONCLUSION In conclusion, our study clarifies the presence of RFC1 protein in the inner BRB, which has recently been defined as hypoxia-immune-related gene in other tissues and offers a novel perspective of retinal RFC1. Hence, other than being a folate carrier, RFC1 is an acute regulator of the inner BRB in healthy and ischemic retinas.
Collapse
Affiliation(s)
- Gokce Gurler
- The Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Nevin Belder
- Biotechnology Institute, Ankara University, Ankara, Turkey
| | | | | | - Gokhan Uruk
- The Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Ertugrul Kilic
- Neuroscience and Neurotechnology Center of Excellence (NÖROM), Ankara, Turkey
- Physiology, Istanbul Medeniyet University, Istanbul, Turkey
| | - Muge Yemisci
- The Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
- Faculty of Medicine, Department of Neurology, Hacettepe University, Ankara, Turkey.
- Neuroscience and Neurotechnology Center of Excellence (NÖROM), Ankara, Turkey.
| |
Collapse
|
9
|
Maher S, Bayachou M, Fu P, Hijaz A, Liu G. Focal adhesion kinase activation is involved in contractile stimulation-induced detrusor muscle contraction in mice. Eur J Pharmacol 2023:175807. [PMID: 37236435 DOI: 10.1016/j.ejphar.2023.175807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 05/28/2023]
Abstract
Recent studies suggested smooth muscle contraction may involve mechanisms besides the myosin regulatory light chain (MLC) phosphorylation-induced actomyosin crossbridge cycling. This study aims to determine if focal adhesion kinase (FAK) activation is involved in mouse detrusor muscle contraction. The mouse detrusor muscle strips were preincubated with PF-573228 (2 μM), latrunculin B (1 μM), or the same volume of vehicle (DMSO) for 30 min. The contractile responses to KCl (90 mM), electrical field stimulation (EFS, 2-32 Hz), or carbachol (CCh, 10-7.5-10-4.5 M) were measured. In a separate experiment, the phosphorylated FAK (p-FAK) and MLC (p-MLC) levels were measured in the detrusor strips stimulated with CCh (10 μM) after incubation with PF-573228 or vehicle (DMSO) compared to those with vehicle incubation but without CCh stimulation. KCl-induced contractile responses decreased significantly after incubation with PF-573228 or latrunculin B compared to the corresponding vehicle-treated strips (p < 0.0001). The contractile responses induced by EFS were markedly inhibited by preincubation with PF-573228 at 8, 16, and 32 Hz (p < 0.05) or latrunculin B at 16 and 32 Hz (p < 0.01). Following the application of PF-573228 or Latrunculin B, CCh-induced dose-response contractions were lower than the corresponding vehicle group (p = 0.0021 and 0.0003, respectively). Western blot examination showed that CCh stimulation enhanced the expression of p-FAK and p-MLC, while preincubation with PF-573228 prevented the increase of p-FAK but not p-MLC. In conclusion, FAK activation involves tension development induced by contractile stimulation in the mouse detrusor muscle. This effect is likely caused by promoting actin polymerization rather than elevating MLC phosphorylation.
Collapse
Affiliation(s)
- Shaimaa Maher
- Department of Surgery, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA; Department of Chemistry, Cleveland State University, Cleveland, OH, USA
| | - Mekki Bayachou
- Department of Chemistry, Cleveland State University, Cleveland, OH, USA; Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Pingfu Fu
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Adonis Hijaz
- Department of Urology, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH, USA
| | - Guiming Liu
- Department of Surgery, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
10
|
Sargent SM, Bonney SK, Li Y, Stamenkovic S, Takeno M, Coelho-Santos V, Shih AY. Endothelial structure contributes to heterogeneity in brain capillary diameter. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538503. [PMID: 37163126 PMCID: PMC10168366 DOI: 10.1101/2023.04.26.538503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The high metabolic demand of brain tissue is supported by a constant supply of blood through dense microvascular networks. Capillaries are the smallest class of vessels and vary in diameter between ∼2 to 5 μm in the brain. This diameter range plays a significant role in the optimization of blood flow resistance, blood cell distribution, and oxygen extraction. The control of capillary diameter has largely been ascribed to pericyte contractility, but it remains unclear if endothelial wall architecture also contributes to capillary diameter heterogeneity. Here, we use public, large-scale volume electron microscopy data from mouse cortex (MICrONS Explorer, Cortical MM^3) to examine how endothelial cell number, endothelial cell thickness, and pericyte coverage relates to microvascular lumen size. We find that transitional vessels near the penetrating arteriole and ascending venule are composed of 2 to 5 interlocked endothelial cells, while the numerous capillary segments intervening these zones are composed of either 1 or 2 endothelial cells, with roughly equal proportions. The luminal area and diameter is on average slightly larger with capillary segments composed of 2 interlocked endothelial cells versus 1 endothelial cell. However, this difference is insufficient to explain the full range of capillary diameters seen in vivo. This suggests that both endothelial structure and other influences, such as pericyte tone, contribute to the basal diameter and optimized perfusion of brain capillaries.
Collapse
|
11
|
Sun X, Wang Y, Zhao Y, Xu X, Lu W, Li Y, Bian F, Xiang L, Zhou L. Activation of the Epac/Rap1 signaling pathway alleviates blood-brain barrier disruption and brain damage following cerebral ischemia/reperfusion injury. Int Immunopharmacol 2023; 117:110014. [PMID: 36931001 DOI: 10.1016/j.intimp.2023.110014] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/04/2023] [Accepted: 03/06/2023] [Indexed: 03/17/2023]
Abstract
Blood brain barrier (BBB) destruction plays a key role in ischemia stroke, including promoting BBB leakage and brain edema, and leads to unfavorable patient prognosis. Epac/Rap1 signaling pathway is important in mediating endothelial cell barrier function. This study will investigate the regulatory role of Epac/Rap1 signaling pathway in BBB disruption after cerebral ischemia/reperfusion (CI/R) injury. CI/R model was induced by 90 min of transient middle cerebral artery occlusion (MCAO) in male C57BL/6J mice. Injection of Epac/Rap1 signaling pathway agonist was performed half an hour before the MCAO operation. The results showed that CI/R injured the tight connection of BBB and evoked the suppression of the Epac/Rap1 signaling pathway. Based on Epac activation with a cAMP analogue, 8-CPT could improve BBB disfunction by increasing the expression of tight junction protein and reducing the formation of stress fibers. In addition, 8-CPT could ameliorate neurobehavioral disorders, cerebral edema, and cerebral infarction volume in MCAO mice. Moreover, inhibition of Epac pathway with Rap1 inhibitor GGTI298 and Rac1 inhibitor NSC23766 could aggravate the damage of BBB and cerebral injury accordingly. Our results indicate that, the activation of Epac/Rap1 signaling pathway has neuroprotective effects on CI/R damaged brain, through the recovery of BBB.
Collapse
Affiliation(s)
- Xuemei Sun
- School of Medical Technology and Nursing, Shenzhen Polytechnic, Shenzhen 518055, China; The Third Affiliated Hospital of Soochow University, The First People's Hospital of Changzhou, 213000, China
| | - Yingnan Wang
- School of Medical Technology and Nursing, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Yuchen Zhao
- Department of Mathematics, University of California, Los Angeles, CA 90095, USA
| | - Xinyi Xu
- School of Medical Technology and Nursing, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Wenjie Lu
- Department of Pharmacology, School of Basic Medical Science, Anhui Medical University, Hefei 230032, China
| | - Yuying Li
- School of Medical Technology and Nursing, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Fei Bian
- School of Medical Technology and Nursing, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Lan Xiang
- School of Medical Technology and Nursing, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Lanlan Zhou
- School of Medical Technology and Nursing, Shenzhen Polytechnic, Shenzhen 518055, China.
| |
Collapse
|
12
|
Cao R, Yang ZS, Hu SL, Liang SJ, Zhang SM, Zhu SQ, Lu L, Long CH, Yao ST, Ma YJ, Liang XH. Molecular Mechanism of Mouse Uterine Smooth Muscle Regulation on Embryo Implantation. Int J Mol Sci 2022; 23:ijms232012494. [PMID: 36293350 PMCID: PMC9604262 DOI: 10.3390/ijms232012494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 10/01/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022] Open
Abstract
Myometrium plays critical roles in multiple processes such as embryo spacing through peristalsis during mouse implantation, indicating vital roles of smooth muscle in the successful establishment and quality of implantation. Actin, a key element of cytoskeleton structure, plays an important role in the movement and contraction of smooth muscle cells (SMCs). However, the function of peri-implantation uterine smooth muscle and the regulation mechanism of muscle tension are still unclear. This study focused on the molecular mechanism of actin assembly regulation on implantation in smooth muscle. Phalloidin is a highly selective bicyclic peptide used for staining actin filaments (also known as F-actin). Phalloidin staining showed that F-actin gradually weakened in the CD-1 mouse myometrium from day 1 to day 4 of early pregnancy. More than 3 mice were studied for each group. Jasplakinolide (Jasp) used to inhibit F-actin depolymerization promotes F-actin polymerization in SMCs during implantation window and consequently compromises embryo implantation quality. Transcriptome analysis following Jasp treatment in mouse uterine SMCs reveals significant molecular changes associated with actin assembly. Tagln is involved in the regulation of the cell cytoskeleton and promotes the polymerization of G-actin to F-actin. Our results show that Tagln expression is gradually reduced in mouse uterine myometrium from day 1 to 4 of pregnancy. Furthermore, progesterone inhibits the expression of Tagln through the progesterone receptor. Using siRNA to knock down Tagln in day 3 SMCs, we found that phalloidin staining is decreased, which confirms the critical role of Tagln in F-actin polymerization. In conclusion, our data suggested that decreases in actin assembly in uterine smooth muscle during early pregnancy is critical to optimal embryo implantation. Tagln, a key molecule involved in actin assembly, regulates embryo implantation by controlling F-actin aggregation before implantation, suggesting moderate uterine contractility is conducive to embryo implantation. This study provides new insights into how the mouse uterus increases its flexibility to accommodate implanting embryos in the early stage of pregnancy.
Collapse
|
13
|
Balaratnasingam C, An D, Hein M, Yu P, Yu DY. Studies of the retinal microcirculation using human donor eyes and high-resolution clinical imaging: Insights gained to guide future research in diabetic retinopathy. Prog Retin Eye Res 2022; 94:101134. [PMID: 37154065 DOI: 10.1016/j.preteyeres.2022.101134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 09/18/2022] [Accepted: 10/03/2022] [Indexed: 11/06/2022]
Abstract
The microcirculation plays a key role in delivering oxygen to and removing metabolic wastes from energy-intensive retinal neurons. Microvascular changes are a hallmark feature of diabetic retinopathy (DR), a major cause of irreversible vision loss globally. Early investigators have performed landmark studies characterising the pathologic manifestations of DR. Previous works have collectively informed us of the clinical stages of DR and the retinal manifestations associated with devastating vision loss. Since these reports, major advancements in histologic techniques coupled with three-dimensional image processing has facilitated a deeper understanding of the structural characteristics in the healthy and diseased retinal circulation. Furthermore, breakthroughs in high-resolution retinal imaging have facilitated clinical translation of histologic knowledge to detect and monitor progression of microcirculatory disturbances with greater precision. Isolated perfusion techniques have been applied to human donor eyes to further our understanding of the cytoarchitectural characteristics of the normal human retinal circulation as well as provide novel insights into the pathophysiology of DR. Histology has been used to validate emerging in vivo retinal imaging techniques such as optical coherence tomography angiography. This report provides an overview of our research on the human retinal microcirculation in the context of the current ophthalmic literature. We commence by proposing a standardised histologic lexicon for characterising the human retinal microcirculation and subsequently discuss the pathophysiologic mechanisms underlying key manifestations of DR, with a focus on microaneurysms and retinal ischaemia. The advantages and limitations of current retinal imaging modalities as determined using histologic validation are also presented. We conclude with an overview of the implications of our research and provide a perspective on future directions in DR research.
Collapse
Affiliation(s)
- Chandrakumar Balaratnasingam
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia; Department of Ophthalmology, Sir Charles Gairdner Hospital, Western Australia, Australia.
| | - Dong An
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
| | - Martin Hein
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
| | - Paula Yu
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
| | - Dao-Yi Yu
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
| |
Collapse
|
14
|
Guo RB, Dong YF, Yin Z, Cai ZY, Yang J, Ji J, Sun YQ, Huang XX, Xue TF, Cheng H, Zhou XQ, Sun XL. Iptakalim improves cerebral microcirculation in mice after ischemic stroke by inhibiting pericyte contraction. Acta Pharmacol Sin 2022; 43:1349-1359. [PMID: 34697419 PMCID: PMC9160281 DOI: 10.1038/s41401-021-00784-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/23/2021] [Indexed: 02/07/2023] Open
Abstract
Pericytes are present tight around the intervals of capillaries, play an essential role in stabilizing the blood-brain barrier, regulating blood flow and immunomodulation, and persistent contraction of pericytes eventually leads to impaired blood flow and poor clinical outcomes in ischemic stroke. We previously show that iptakalim, an ATP-sensitive potassium (K-ATP) channel opener, exerts protective effects in neurons, and glia against ischemia-induced injury. In this study we investigated the impacts of iptakalim on pericytes contraction in stroke. Mice were subjected to cerebral artery occlusion (MCAO), then administered iptakalim (10 mg/kg, ip). We showed that iptakalim administration significantly promoted recovery of cerebral blood flow after cerebral ischemia and reperfusion. Furthermore, we found that iptakalim significantly inhibited pericytes contraction, decreased the number of obstructed capillaries, and improved cerebral microcirculation. Using a collagen gel contraction assay, we demonstrated that cultured pericytes subjected to oxygen-glucose deprivation (OGD) consistently contracted from 3 h till 24 h during reoxygenation, whereas iptakalim treatment (10 μM) notably restrained pericyte contraction from 6 h during reoxygenation. We further showed that iptakalim treatment promoted K-ATP channel opening via suppressing SUR2/EPAC1 complex formation. Consequently, it reduced calcium influx and ET-1 release. Taken together, our results demonstrate that iptakalim, targeted K-ATP channels, can improve microvascular disturbance by inhibiting pericyte contraction after ischemic stroke. Our work reveals that iptakalim might be developed as a promising pericyte regulator for treatment of stroke.
Collapse
Affiliation(s)
- Ruo-bing Guo
- grid.89957.3a0000 0000 9255 8984Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, 211166 China
| | - Yin-feng Dong
- grid.410745.30000 0004 1765 1045Nanjing University of Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, 210029 China
| | - Zhi Yin
- grid.412676.00000 0004 1799 0784The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Zhen-yu Cai
- grid.89957.3a0000 0000 9255 8984Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, 211166 China
| | - Jin Yang
- grid.89957.3a0000 0000 9255 8984Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, 211166 China
| | - Juan Ji
- grid.89957.3a0000 0000 9255 8984Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, 211166 China
| | - Yu-qin Sun
- grid.89957.3a0000 0000 9255 8984Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, 211166 China
| | - Xin-xin Huang
- grid.412676.00000 0004 1799 0784The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Teng-fei Xue
- grid.89957.3a0000 0000 9255 8984Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, 211166 China
| | - Hong Cheng
- grid.412676.00000 0004 1799 0784The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Xi-qiao Zhou
- grid.410745.30000 0004 1765 1045Nanjing University of Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, 210029 China
| | - Xiu-lan Sun
- grid.89957.3a0000 0000 9255 8984Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, 211166 China ,grid.410745.30000 0004 1765 1045Nanjing University of Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, 210029 China
| |
Collapse
|
15
|
Zhu WM, Neuhaus A, Beard DJ, Sutherland BA, DeLuca GC. Neurovascular coupling mechanisms in health and neurovascular uncoupling in Alzheimer's disease. Brain 2022; 145:2276-2292. [PMID: 35551356 PMCID: PMC9337814 DOI: 10.1093/brain/awac174] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/05/2022] [Accepted: 05/07/2022] [Indexed: 11/25/2022] Open
Abstract
To match the metabolic demands of the brain, mechanisms have evolved to couple neuronal activity to vasodilation, thus increasing local cerebral blood flow and delivery of oxygen and glucose to active neurons. Rather than relying on metabolic feedback signals such as the consumption of oxygen or glucose, the main signalling pathways rely on the release of vasoactive molecules by neurons and astrocytes, which act on contractile cells. Vascular smooth muscle cells and pericytes are the contractile cells associated with arterioles and capillaries, respectively, which relax and induce vasodilation. Much progress has been made in understanding the complex signalling pathways of neurovascular coupling, but issues such as the contributions of capillary pericytes and astrocyte calcium signal remain contentious. Study of neurovascular coupling mechanisms is especially important as cerebral blood flow dysregulation is a prominent feature of Alzheimer’s disease. In this article we will discuss developments and controversies in the understanding of neurovascular coupling and finish by discussing current knowledge concerning neurovascular uncoupling in Alzheimer’s disease.
Collapse
Affiliation(s)
- Winston M Zhu
- Oxford Medical School, University of Oxford, Oxford, UK
| | - Ain Neuhaus
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Daniel J Beard
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
| | - Brad A Sutherland
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Gabriele C DeLuca
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| |
Collapse
|
16
|
Suppression of trabecular meshwork phagocytosis by norepinephrine is associated with nocturnal increase in intraocular pressure in mice. Commun Biol 2022; 5:339. [PMID: 35396348 PMCID: PMC8993819 DOI: 10.1038/s42003-022-03295-y] [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: 11/11/2021] [Accepted: 03/17/2022] [Indexed: 11/18/2022] Open
Abstract
Intraocular pressure (IOP) is an important factor in glaucoma development, which involves aqueous humor (AH) dynamics, with inflow from the ciliary body and outflow through the trabecular meshwork (TM). IOP has a circadian rhythm entrained by sympathetic noradrenaline (NE) or adrenal glucocorticoids (GCs). Herein, we investigated the involvement of GC/NE in AH outflow. Pharmacological prevention of inflow/outflow in mice indicated a diurnal outflow increase, which was related to TM phagocytosis. NE showed a non-self-sustained inhibition in phagocytosis of immortalized human TM cells, but not GC. The pharmacological and reverse genetic approaches identified β1-adrenergic receptor (AR)-mediated exchange proteins directly activated by cyclic adenosine monophosphate (EPAC)-SHIP1 signal activation by ablation of phosphatidylinositol triphosphate, regulating phagocytic cup formation. Furthermore, we revealed the phagocytosis involvement in the β1-AR-EPAC-SHIP1-mediated nocturnal IOP rise in mice. These suggest that TM phagocytosis suppression by NE can regulate IOP rhythm through AH outflow. This discovery may aid glaucoma management. Intraocular pressure, which can cause glaucoma, is found to be affected by nocturnal sympathetic noradrenaline, which inhibits phagocytosis in trabecular meshwork cells through β1-aderenergic receptor mediated cAMP-EPAC-SHIP1 activation.
Collapse
|
17
|
Erdener ŞE, Küreli G, Dalkara T. Contractile apparatus in CNS capillary pericytes. NEUROPHOTONICS 2022; 9:021904. [PMID: 35106320 PMCID: PMC8785978 DOI: 10.1117/1.nph.9.2.021904] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Significance: Whether or not capillary pericytes contribute to blood flow regulation in the brain and retina has long been debated. This was partly caused by failure of detecting the contractile protein α -smooth muscle actin ( α -SMA) in capillary pericytes. Aim: The aim of this review is to summarize recent developments in detecting α -SMA and contractility in capillary pericytes and the relevant literature on the biology of actin filaments. Results: Evidence suggests that for visualization of the small amounts of α -SMA in downstream mid-capillary pericytes, actin depolymerization must be prevented during tissue processing. Actin filaments turnover is mainly based on de/re-polymerization rather than transcription of the monomeric form, hence, small amounts of α -SMA mRNA may evade detection by transcriptomic studies. Similarly, transgenic mice expressing fluorescent reporters under the α -SMA promoter may yield low fluorescence due to limited transcriptional activity in mid-capillary pericytes. Recent studies show that pericytes including mid-capillary ones express several actin isoforms and myosin heavy chain type 11, the partner of α -SMA in mediating contraction. Emerging evidence also suggests that actin polymerization in pericytes may have a role in regulating the tone of downstream capillaries. Conclusions: With guidance of actin biology, innovative labeling and imaging techniques can reveal the molecular machinery of contraction in pericytes.
Collapse
Affiliation(s)
- Şefik E. Erdener
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Gülce Küreli
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| | - Turgay Dalkara
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey
| |
Collapse
|
18
|
Freitas F, Attwell D. Pericyte-mediated constriction of renal capillaries evokes no-reflow and kidney injury following ischaemia. eLife 2022; 11:74211. [PMID: 35285797 PMCID: PMC8947765 DOI: 10.7554/elife.74211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 03/09/2022] [Indexed: 12/12/2022] Open
Abstract
Acute kidney injury is common, with ~13 million cases and 1.7 million deaths/year worldwide. A major cause is renal ischaemia, typically following cardiac surgery, renal transplant or severe haemorrhage. We examined the cause of the sustained reduction in renal blood flow ('no-reflow'), which exacerbates kidney injury even after an initial cause of compromised blood supply is removed. Adult male Sprague-Dawley rats, or NG2-dsRed male mice were used in this study. After 60 min kidney ischaemia and 30-60 min reperfusion, renal blood flow remained reduced, especially in the medulla, and kidney tubule damage was detected as Kim-1 expression. Constriction of the medullary descending vasa recta and cortical peritubular capillaries occurred near pericyte somata, and led to capillary blockages, yet glomerular arterioles and perfusion were unaffected, implying that the long-lasting decrease of renal blood flow contributing to kidney damage was generated by pericytes. Blocking Rho kinase to decrease pericyte contractility from the start of reperfusion increased the post-ischaemic diameter of the descending vasa recta capillaries at pericytes, reduced the percentage of capillaries that remained blocked, increased medullary blood flow and reduced kidney injury. Thus, post-ischaemic renal no-reflow, contributing to acute kidney injury, reflects pericytes constricting the descending vasa recta and peritubular capillaries. Pericytes are therefore an important therapeutic target for treating acute kidney injury.
Collapse
Affiliation(s)
- Felipe Freitas
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - David Attwell
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| |
Collapse
|
19
|
Zhang S, Liao XJ, Wang J, Shen Y, Shi HF, Zou Y, Ma CY, Wang XQ, Wang QG, Wang X, Xu MY, Cheng FF, Bai WZ. Temporal alterations in pericytes at the acute phase of ischemia/reperfusion in the mouse brain. Neural Regen Res 2022; 17:2247-2252. [PMID: 35259845 PMCID: PMC9083170 DOI: 10.4103/1673-5374.336876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Pericytes, as the mural cells surrounding the microvasculature, play a critical role in the regulation of microcirculation; however, how these cells respond to ischemic stroke remains unclear. To determine the temporal alterations in pericytes after ischemia/reperfusion, we used the 1-hour middle cerebral artery occlusion model, which was examined at 2, 12, and 24 hours after reperfusion. Our results showed that in the reperfused regions, the cerebral blood flow decreased and the infarct volume increased with time. Furthermore, the pericytes in the infarct regions contracted and acted on the vascular endothelial cells within 24 hours after reperfusion. These effects may result in incomplete microcirculation reperfusion and a gradual worsening trend with time in the acute phase. These findings provide strong evidence for explaining the "no-reflow" phenomenon that occurs after recanalization in clinical practice.
Collapse
Affiliation(s)
- Shuang Zhang
- Beijing Key Laboratory, School of Basic Medical Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Xue-Jing Liao
- Beijing Key Laboratory, School of Basic Medical Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Jia Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yi Shen
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Han-Fen Shi
- Beijing Key Laboratory, School of Basic Medical Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Yan Zou
- Shineway Pharmaceutical Group Ltd., Shijiazhuang, Hebei Province, China
| | - Chong-Yang Ma
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Xue-Qian Wang
- Beijing Key Laboratory, School of Basic Medical Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Qing-Guo Wang
- Beijing Key Laboratory, School of Basic Medical Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Xu Wang
- Beijing Key Laboratory, School of Basic Medical Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Ming-Yang Xu
- Beijing Key Laboratory, School of Basic Medical Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Fa-Feng Cheng
- Beijing Key Laboratory, School of Basic Medical Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Wan-Zhu Bai
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| |
Collapse
|
20
|
Rungta RL, Zuend M, Aydin AK, Martineau É, Boido D, Weber B, Charpak S. Diversity of neurovascular coupling dynamics along vascular arbors in layer II/III somatosensory cortex. Commun Biol 2021; 4:855. [PMID: 34244604 PMCID: PMC8270975 DOI: 10.1038/s42003-021-02382-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 06/10/2021] [Indexed: 11/08/2022] Open
Abstract
The spatial-temporal sequence of cerebral blood flow (CBF), cerebral blood volume (CBV) and blood velocity changes triggered by neuronal activation is critical for understanding functional brain imaging. This sequence follows a stereotypic pattern of changes across different zones of the vasculature in the olfactory bulb, the first relay of olfaction. However, in the cerebral cortex, where most human brain mapping studies are performed, the timing of activity evoked vascular events remains controversial. Here we utilized a single whisker stimulation model to map out functional hyperemia along vascular arbours from layer II/III to the surface of primary somatosensory cortex, in anesthetized and awake Thy1-GCaMP6 mice. We demonstrate that sensory stimulation triggers an increase in blood velocity within the mid-capillary bed and a dilation of upstream large capillaries, and the penetrating and pial arterioles. We report that under physiological stimulation, response onset times are highly variable across compartments of different vascular arbours. Furthermore, generating transfer functions (TFs) between neuronal Ca2+ and vascular dynamics across different brain states demonstrates that anesthesia decelerates neurovascular coupling (NVC). This spatial-temporal pattern of vascular events demonstrates functional diversity not only between different brain regions but also at the level of different vascular arbours within supragranular layers of the cerebral cortex.
Collapse
Affiliation(s)
- Ravi L Rungta
- INSERM U1128, Laboratory of Neurophysiology and New Microscopy, Université Paris Descartes, Paris, France.
- Faculté de Médecine Dentaire, Université de Montréal, Montréal, QC, Canada.
- Centre Interdisciplinaire de Recherche sur le Cerveau et l'Apprentissage, Université de Montréal, Montréal, QC, Canada.
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, QC, Canada.
| | - Marc Zuend
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Ali-Kemal Aydin
- INSERM U1128, Laboratory of Neurophysiology and New Microscopy, Université Paris Descartes, Paris, France
- INSERM, CNRS, Institut de la Vision, Sorbonne Université, Paris, France
| | - Éric Martineau
- Faculté de Médecine Dentaire, Université de Montréal, Montréal, QC, Canada
- Centre Interdisciplinaire de Recherche sur le Cerveau et l'Apprentissage, Université de Montréal, Montréal, QC, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, QC, Canada
| | - Davide Boido
- INSERM U1128, Laboratory of Neurophysiology and New Microscopy, Université Paris Descartes, Paris, France
- NeuroSpin, Bat. 145, Commissariat à l'Energie Atomique ' Saclay Center, Gif-sur-Yvette, France
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Serge Charpak
- INSERM U1128, Laboratory of Neurophysiology and New Microscopy, Université Paris Descartes, Paris, France.
- INSERM, CNRS, Institut de la Vision, Sorbonne Université, Paris, France.
| |
Collapse
|
21
|
Affiliation(s)
- Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
| |
Collapse
|
22
|
Brain capillary pericytes exert a substantial but slow influence on blood flow. Nat Neurosci 2021; 24:633-645. [PMID: 33603231 PMCID: PMC8102366 DOI: 10.1038/s41593-020-00793-2] [Citation(s) in RCA: 163] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 12/23/2020] [Indexed: 01/30/2023]
Abstract
The majority of the brain's vasculature is composed of intricate capillary networks lined by capillary pericytes. However, it remains unclear whether capillary pericytes influence blood flow. Using two-photon microscopy to observe and manipulate brain capillary pericytes in vivo, we find that their optogenetic stimulation decreases lumen diameter and blood flow, but with slower kinetics than similar stimulation of mural cells on upstream pial and precapillary arterioles. This slow vasoconstriction was inhibited by the clinically used vasodilator fasudil, a Rho-kinase inhibitor that blocks contractile machinery. Capillary pericytes were also slower to constrict back to baseline following hypercapnia-induced dilation, and slower to dilate towards baseline following optogenetically induced vasoconstriction. Optical ablation of single capillary pericytes led to sustained local dilation and a doubling of blood cell flux selectively in capillaries lacking pericyte contact. These data indicate that capillary pericytes contribute to basal blood flow resistance and slow modulation of blood flow throughout the brain.
Collapse
|
23
|
Grubb S, Lauritzen M, Aalkjær C. Brain capillary pericytes and neurovascular coupling. Comp Biochem Physiol A Mol Integr Physiol 2021; 254:110893. [DOI: 10.1016/j.cbpa.2020.110893] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/28/2020] [Accepted: 12/28/2020] [Indexed: 12/23/2022]
|
24
|
Alarcon-Martinez L, Yemisci M, Dalkara T. Pericyte morphology and function. Histol Histopathol 2021; 36:633-643. [PMID: 33595091 DOI: 10.14670/hh-18-314] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The proper delivery of blood is essential for healthy neuronal function. The anatomical substrate for this precise mechanism is the neurovascular unit, which is formed by neurons, glial cells, endothelia, smooth muscle cells, and pericytes. Based on their particular location on the vessel wall, morphology, and protein expression, pericytes have been proposed as cells capable of regulating capillary blood flow. Pericytes are located around the microvessels, wrapping them with their processes. Their morphology and protein expression substantially vary along the vascular tree. Their contractibility is mediated by a unique cytoskeleton organization formed by filaments of actin that allows pericyte deformability with the consequent mechanical force transferred to the extracellular matrix for changing the diameter. Pericyte ultrastructure is characterized by large mitochondria likely to provide energy to regulate intracellular calcium concentration and fuel contraction. Accordingly, pericytes with compromised energy show a sustained intracellular calcium increase that leads to persistent microvascular constriction. Pericyte morphology is highly plastic and adapted for varying contractile capability along the microvascular tree, making pericytes ideal cells to regulate the capillary blood flow in response to local neuronal activity. Besides the vascular regulation, pericytes also play a role in the maintenance of the blood-brain/retina barrier, neovascularization and angiogenesis, and leukocyte transmigration. Here, we review the morphological and functional features of the pericytes as well as potential specific markers for the study of pericytes in the brain and retina.
Collapse
Affiliation(s)
- Luis Alarcon-Martinez
- Department of Neuroscience and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, QC, Canada.
| | - Muge Yemisci
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
| |
Collapse
|
25
|
Mai-Morente SP, Marset VM, Blanco F, Isasi EE, Abudara V. A nuclear fluorescent dye identifies pericytes at the neurovascular unit. J Neurochem 2020; 157:1377-1391. [PMID: 32974913 DOI: 10.1111/jnc.15193] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/27/2020] [Accepted: 09/14/2020] [Indexed: 11/26/2022]
Abstract
Perivascular pericytes are key regulators of the blood-brain barrier, vascular development, and cerebral blood flow. Deciphering pericyte roles in health and disease requires cellular tracking; yet, pericyte identification remains challenging. A previous study reported that the far-red fluorophore TO-PRO-3 (642/661), usually employed as a nuclear dye in fixed tissue, was selectively captured by live pericytes from the subventricular zone. Herein, we validated TO-PRO-3 as a specific pericyte tracer in the nervous system (NS). Living pericytes from ex vivo murine hippocampus, cortex, spinal cord, and retina robustly incorporated TO-PRO-3. Classical pericyte immunomarkers such as chondroitin sulphate proteoglycan neuron-glial antigen 2 (NG2) and platelet-derived growth factor receptor beta antigen (PDGFrβ) and the new pericyte dye NeuroTrace 500/525 confirmed cellular specificity of dye uptake. The TO-PRO-3 signal enabled quantification of pericytes density and morphometry; likewise, TO-PRO-3 labeling allowed visualization of pericytes associated with other components of the neurovascular unit. A subset of TO-PRO-3 stained cells expressed the contractile protein α-SMA, indicative of their ability to control the capillary diameter. Uptake of TO-PRO-3 was independent of connexin/pannexin channels but was highly sensitive to temperature and showed saturation, suggesting that a yet unidentified protein-mediated active transport sustained dye incorporation. We conclude that TO-PRO-3 labeling provides a reliable and simple tool for the bioimaging of pericytes in the murine NS microvasculature.
Collapse
Affiliation(s)
- Sandra P Mai-Morente
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Virginia M Marset
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Fabiana Blanco
- Departamento de Biofísica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Eugenia E Isasi
- Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Verónica Abudara
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| |
Collapse
|