1
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Islam MM, Gaska I, Oshinowo O, Otumala A, Shekhar S, Au Yong N, Myers DR. Single-pericyte nanomechanics measured by contraction cytometry. APL Bioeng 2024; 8:036109. [PMID: 39131206 PMCID: PMC11316606 DOI: 10.1063/5.0213761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 07/02/2024] [Indexed: 08/13/2024] Open
Abstract
Pericytes line the microvasculature throughout the body and play a key role in regulating blood flow by constricting and dilating vessels. However, the biophysical mechanisms through which pericytes transduce microenvironmental chemical and mechanical cues to mediate vessel diameter, thereby impacting oxygen and nutrient delivery, remain largely unknown. This knowledge gap is clinically relevant as numerous diseases are associated with the aberrant contraction of pericytes, which are unusually susceptible to injury. Here, we report the development of a high-throughput hydrogel-based pericyte contraction cytometer that quantifies single-cell contraction forces from murine and human pericytes in different microvascular microenvironments and in the presence of competing vasoconstricting and vasodilating stimuli. We further show that murine pericyte survival in hypoxia is mediated by the mechanical microenvironment and that, paradoxically, pre-treating pericytes to reduce contraction increases hypoxic cell death. Moreover, using the contraction cytometer as a drug-screening tool, we found that cofilin-1 could be applied extracellularly to release murine pericytes from hypoxia-induced contractile rigor mortis and, therefore, may represent a novel approach for mitigating the long-lasting decrease in blood flow that occurs after hypoxic injury.
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Affiliation(s)
| | - Ignas Gaska
- Departments of Physics, Cell Biology and Biochemistry, Emory University, Atlanta, Georgia 30322, USA
| | | | | | - Shashank Shekhar
- Departments of Physics, Cell Biology and Biochemistry, Emory University, Atlanta, Georgia 30322, USA
| | | | - David R. Myers
- Author to whom correspondence should be addressed:. Tel.: 404-727-0401
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2
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Newman M, Rasiah PK, Kusunose J, Rex TS, Mahadevan-Jansen A, Hardenburger J, Jansen ED, Millis B, Caskey CF. Ultrasound Modulates Calcium Activity in Cultured Neurons, Glial Cells, Endothelial Cells and Pericytes. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:341-351. [PMID: 38087717 DOI: 10.1016/j.ultrasmedbio.2023.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 10/27/2023] [Accepted: 11/03/2023] [Indexed: 01/23/2024]
Abstract
OBJECTIVE Ultrasound is being researched as a method to modulate the brain. Studies of the interaction of sound with neurons support the hypothesis that mechanosensitive ion channels play an important role in ultrasound neuromodulation. The response of cells other than neurons (e.g., astrocytes, pericytes and endothelial cells) have not been fully characterized, despite playing an important role in brain function. METHODS To address this gap in knowledge, we examined cultured murine primary cortical neurons, astrocytes, endothelial cells and pericytes in an in vitro widefield microscopy setup during application of a 500 ms burst of 250 kHz focused ultrasound over a pressure range known to elicit neuromodulation. We examined cell membrane health in response to a range of pulses and used optical calcium indicators in conjunction with pharmacological antagonists to selectively block different groups of thermo- and mechanosensitive ion channels known to be responsive to ultrasound. RESULTS All cell types experienced an increase in calcium fluorescence in response to ultrasound. Gadolinium (Gad), 2-aminoethoxydiphenyl borate (2-APB) and ruthenium red (RR) reduced the percentage of responding neurons and magnitude of response. The percentage of astrocytes responding was significantly lowered only by Gad, whereas both 2-APB and Gad decreased the amplitude of the fluorescence response. 2-APB decreased the percentage of responding endothelial cells, whereas only Gad reduced the magnitude of responses. Pericytes exposed to RR or Gad were less likely to respond to stimulation. RR had no detectable effect on the magnitude of the pericyte responses while 2-APB and Gad significantly decreased the fluorescence intensity, despite not affecting the percentage responding. CONCLUSION Our study highlights the role of non-neuronal cells during FUS neuromodulation. All of the investigated cell types are sensitive to mechanical ultrasound stimulation and rely on mechanosensitive ion channels to undergo ultrasound neuromodulation.
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Affiliation(s)
- Malachy Newman
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Pratheepa Kumari Rasiah
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt Biophotonics Center, Nashville, TN, USA
| | - Jiro Kusunose
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA; Department of Radiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Tonia S Rex
- Department of Opthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Anita Mahadevan-Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt Biophotonics Center, Nashville, TN, USA
| | - Jacob Hardenburger
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt Biophotonics Center, Nashville, TN, USA
| | - E Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt Biophotonics Center, Nashville, TN, USA
| | - Bryan Millis
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt Biophotonics Center, Nashville, TN, USA
| | - Charles F Caskey
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Department of Radiology, Vanderbilt University Medical Center, Nashville, TN, USA.
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3
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Milani SZ, Rezabakhsh A, Karimipour M, Salimi L, Mardi N, Narmi MT, Sadeghsoltani F, Valioglu F, Rahbarghazi R. Role of autophagy in angiogenic potential of vascular pericytes. Front Cell Dev Biol 2024; 12:1347857. [PMID: 38380339 PMCID: PMC10877016 DOI: 10.3389/fcell.2024.1347857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/24/2024] [Indexed: 02/22/2024] Open
Abstract
The vasculature system is composed of a multiplicity of juxtaposed cells to generate a functional biological barrier between the blood and tissues. On the luminal surface of blood vessels, endothelial cells (ECs) are in close contact with circulating cells while supporting basal lamina and pericytes wrap the abluminal surface. Thus, the reciprocal interaction of pericytes with ECs is a vital element in the physiological activity of the vascular system. Several reports have indicated that the occurrence of pericyte dysfunction under ischemic and degenerative conditions results in varied micro and macro-vascular complications. Emerging evidence points to the fact that autophagy, a conserved self-digestive cell machinery, can regulate the activity of several cells like pericytes in response to various stresses and pathological conditions. Here, we aim to highlight the role of autophagic response in pericyte activity and angiogenesis potential following different pathological conditions.
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Affiliation(s)
- Soheil Zamen Milani
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Aysa Rezabakhsh
- Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Karimipour
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Leila Salimi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Narges Mardi
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | | | - Ferzane Valioglu
- Technology Development Zones Management CO., Sakarya University, Sakarya, Türkiye
| | - Reza Rahbarghazi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Applied Cellular Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
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4
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Mechanisms of the "No-Reflow" Phenomenon After Acute Myocardial Infarction: Potential Role of Pericytes. JACC Basic Transl Sci 2023; 8:204-220. [PMID: 36908667 PMCID: PMC9998747 DOI: 10.1016/j.jacbts.2022.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/13/2022] [Accepted: 06/13/2022] [Indexed: 11/20/2022]
Abstract
Pericytes contract during myocardial ischemia resulting in capillary constriction and no reflow. Reversing pericyte contraction pharmacologically reduces no reflow and infarct size. These findings open up an entire new venue of research aimed at altering pericyte function in myocardial ischemia and infarction.
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5
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Goswami AG, Basu S, Huda F, Pant J, Ghosh Kar A, Banerjee T, Shukla VK. An appraisal of vascular endothelial growth factor (VEGF): the dynamic molecule of wound healing and its current clinical applications. Growth Factors 2022; 40:73-88. [PMID: 35584274 DOI: 10.1080/08977194.2022.2074843] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Angiogenesis is a critical step of wound healing, and its failure leads to chronic wounds. The idea of restoring blood flow to the damaged tissues by promoting neo-angiogenesis is lucrative and has been researched extensively. Vascular endothelial growth factor (VEGF), a key dynamic molecule of angiogenesis has been investigated for its functions. In this review, we aim to appraise its biology, the comprehensive role of this dynamic molecule in the wound healing process, and how this knowledge has been translated in clinical application in various types of wounds. Although, most laboratory research on the use of VEGF is promising, its clinical applications have not met great expectations. We discuss various lacunae that might exist in making its clinical application unsuccessful for commercial use, and provide insight to the foundation for future research.
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Affiliation(s)
- Aakansha Giri Goswami
- Department of General surgery, All India Institute of Medical Sciences, Rishikesh, India
| | - Somprakas Basu
- Department of General surgery, All India Institute of Medical Sciences, Rishikesh, India
| | - Farhanul Huda
- Department of General surgery, All India Institute of Medical Sciences, Rishikesh, India
| | - Jayanti Pant
- Department of Physiology, All India Institute of Medical Sciences, Rishikesh, India
| | - Amrita Ghosh Kar
- Department of Pathology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Tuhina Banerjee
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Vijay Kumar Shukla
- Department of General Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
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6
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Le DE, Zhao Y, Kaul S. Persistent Coronary Vasomotor Tone During Myocardial Ischemia Occurs at the Capillary Level and May Involve Pericytes. Front Cardiovasc Med 2022; 9:930492. [PMID: 35811707 PMCID: PMC9263193 DOI: 10.3389/fcvm.2022.930492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 05/23/2022] [Indexed: 11/24/2022] Open
Abstract
Background There is persistent coronary vasomotor tone during myocardial ischemia, despite ongoing coronary arteriolar dilatation. The mechanism underlying this vasodilatory tone, which can be unmasked by coronary vasodilators, is unclear. We hypothesized that persistent microvascular resistance during myocardial ischemia occurs at the level of capillaries and may be caused by pericytes. Methods We studied nine instrumented dogs where coronary blood flow and coronary driving pressure were reduced to half by placement of stenoses. Myocardial blood flow and myocardial blood volume were measured with myocardial contrast echocardiography before and during adenosine administration. In three animals, the heart was perfusion-fixed under these conditions for electron microscopic assessment of capillary and pericyte size. Results During ischemia, myocardial blood volume decreased and myocardial vascular resistance remained unchanged. Adenosine administration reversed the decline in myocardial blood volume and decreased myocardial vascular resistance. Electron microscopy showed larger capillaries in ischemic beds receiving adenosine than ischemic beds not receiving adenosine. Pericytes in beds receiving adenosine also tended to be larger. Conclusion Capillaries are the site of persistent vasomotor tone during myocardial ischemia; any other site of vascular regulation (arterioles or venules) cannot explain these myocardial contrast echocardiography findings, which are confirmed on post-mortem electron microscopic examination. The decrease in capillary size is likely caused by pericyte contraction in an attempt to maintain a constant capillary hydrostatic pressure. Adenosine relaxes pericytes, restores myocardial blood volume, reduces myocardial vascular resistance, and improves regional function during ischemia. These findings could have important therapeutic implications.
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Affiliation(s)
- D. Elizabeth Le
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
- Cardiology Section, Department of Hospital and Specialty Medicine, Veterans Administration Portland Health Care System, Portland, OR, United States
- *Correspondence: D. Elizabeth Le
| | - Yan Zhao
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
| | - Sanjiv Kaul
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
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7
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Akbarian M, Bertassoni LE, Tayebi L. Biological aspects in controlling angiogenesis: current progress. Cell Mol Life Sci 2022; 79:349. [PMID: 35672585 PMCID: PMC10171722 DOI: 10.1007/s00018-022-04348-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/01/2022] [Accepted: 05/03/2022] [Indexed: 12/25/2022]
Abstract
All living beings continue their life by receiving energy and by excreting waste products. In animals, the arteries are the pathways of these transfers to the cells. Angiogenesis, the formation of the arteries by the development of pre-existed parental blood vessels, is a phenomenon that occurs naturally during puberty due to certain physiological processes such as menstruation, wound healing, or the adaptation of athletes' bodies during exercise. Nonetheless, the same life-giving process also occurs frequently in some patients and, conversely, occurs slowly in some physiological problems, such as cancer and diabetes, so inhibiting angiogenesis has been considered to be one of the important strategies to fight these diseases. Accordingly, in tissue engineering and regenerative medicine, the highly controlled process of angiogenesis is very important in tissue repairing. Excessive angiogenesis can promote tumor progression and lack of enough angiogensis can hinder tissue repair. Thereby, both excessive and deficient angiogenesis can be problematic, this review article introduces and describes the types of factors involved in controlling angiogenesis. Considering all of the existing strategies, we will try to lay out the latest knowledge that deals with stimulating/inhibiting the angiogenesis. At the end of the article, owing to the early-reviewed mechanical aspects that overshadow angiogenesis, the strategies of angiogenesis in tissue engineering will be discussed.
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Affiliation(s)
- Mohsen Akbarian
- Department of Chemistry, National Cheng Kung University, Tainan, 701, Taiwan
| | - Luiz E Bertassoni
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA
| | - Lobat Tayebi
- Marquette University School of Dentistry, Milwaukee, WI, 53233, USA.
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8
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Angiogenic Effects and Crosstalk of Adipose-Derived Mesenchymal Stem/Stromal Cells and Their Extracellular Vesicles with Endothelial Cells. Int J Mol Sci 2021; 22:ijms221910890. [PMID: 34639228 PMCID: PMC8509224 DOI: 10.3390/ijms221910890] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/02/2021] [Accepted: 10/04/2021] [Indexed: 12/13/2022] Open
Abstract
Adipose-derived mesenchymal stem/stromal cells (ASCs) are an adult stem cell population able to self-renew and differentiate into numerous cell lineages. ASCs provide a promising future for therapeutic angiogenesis due to their ability to promote blood vessel formation. Specifically, their ability to differentiate into endothelial cells (ECs) and pericyte-like cells and to secrete angiogenesis-promoting growth factors and extracellular vesicles (EVs) makes them an ideal option in cell therapy and in regenerative medicine in conditions including tissue ischemia. In recent angiogenesis research, ASCs have often been co-cultured with an endothelial cell (EC) type in order to form mature vessel-like networks in specific culture conditions. In this review, we introduce co-culture systems and co-transplantation studies between ASCs and ECs. In co-cultures, the cells communicate via direct cell-cell contact or via paracrine signaling. Most often, ASCs are found in the perivascular niche lining the vessels, where they stabilize the vascular structures and express common pericyte surface proteins. In co-cultures, ASCs modulate endothelial cells and induce angiogenesis by promoting tube formation, partly via secretion of EVs. In vivo co-transplantation of ASCs and ECs showed improved formation of functional vessels over a single cell type transplantation. Adipose tissue as a cell source for both mesenchymal stem cells and ECs for co-transplantation serves as a prominent option for therapeutic angiogenesis and blood perfusion in vivo.
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9
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Dessalles CA, Babataheri A, Barakat AI. Pericyte mechanics and mechanobiology. J Cell Sci 2021; 134:134/6/jcs240226. [PMID: 33753399 DOI: 10.1242/jcs.240226] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pericytes are mural cells of the microvasculature, recognized by their thin processes and protruding cell body. Pericytes wrap around endothelial cells and play a central role in regulating various endothelial functions, including angiogenesis and inflammation. They also serve as a vascular support and regulate blood flow by contraction. Prior reviews have examined pericyte biological functions and biochemical signaling pathways. In this Review, we focus on the role of mechanics and mechanobiology in regulating pericyte function. After an overview of the morphology and structure of pericytes, we describe their interactions with both the basement membrane and endothelial cells. We then turn our attention to biophysical considerations, and describe contractile forces generated by pericytes, mechanical forces exerted on pericytes, and pericyte responses to these forces. Finally, we discuss 2D and 3D engineered in vitro models for studying pericyte mechano-responsiveness and underscore the need for more evolved models that provide improved understanding of pericyte function and dysfunction.
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Affiliation(s)
- Claire A Dessalles
- LadHyX, CNRS, Ecole polytechnique, Institut polytechnique de Paris, 91120, Palaiseau, France
| | - Avin Babataheri
- LadHyX, CNRS, Ecole polytechnique, Institut polytechnique de Paris, 91120, Palaiseau, France
| | - Abdul I Barakat
- LadHyX, CNRS, Ecole polytechnique, Institut polytechnique de Paris, 91120, Palaiseau, France
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10
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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: 14] [Impact Index Per Article: 4.7] [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.
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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
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11
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Hohberger B, Lucio M, Schlick S, Wollborn A, Hosari S, Mardin C. OCT-angiography: Regional reduced macula microcirculation in ocular hypertensive and pre-perimetric glaucoma patients. PLoS One 2021; 16:e0246469. [PMID: 33571215 PMCID: PMC7877568 DOI: 10.1371/journal.pone.0246469] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/19/2021] [Indexed: 12/22/2022] Open
Abstract
PURPOSE OCT-angiography (OCT-A) offers a non-invasive method to visualize retinochoroidal microvasculature. As glaucoma disease affects retinal ganglion cells in the macula, macular microcirculation is of interest. The purpose of the study was to investigate regional macular vascular characteristics in patients with ocular hypertension (OHT), pre-perimetric primary open-angle glaucoma (pre-POAG) and controls by OCT-A in three microvascular layers. MATERIAL AND METHODS 180 subjects were recruited from the Erlangen Glaucoma Registry, the Department of Ophthalmology, University of Erlangen and residents: 38 OHT, 20 pre-POAG, 122 controls. All subjects received an ophthalmological examination including measurements of retinal nerve fibre layer (RNFL), retinal ganglion cell layer (RGC), inner nuclear layer (INL), and Bruch's Membrane Opening-Minimum Rim Width (BMO-MRW). Macular vascular characteristics (vessel density, VD, foveal avascular zone, FAZ) were measured by OCT-A (Spectralis OCT II) in superficial vascular plexus (SVP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP). RESULTS With age correction of VD data, type 3 tests on fixed effects showed a significant interaction between diagnosis and sectorial VD in SVP (p = 0.0004), ICP (p = 0.0073), and DCP (p = 0.0003). Moreover, a significance in sectorial VD was observed within each layer (p<0.0001) and for the covariate age (p<0.0001). FAZ differed significantly between patients' groups only in ICP (p = 0.03), not in SVP and DCP. For VD the AUC values of SVP, ICP, and DCP were highest among diagnostic modalities (AUC: 0.88, 95%-CI: 0.75-1.0, p<0.001). CONCLUSION Regional reduced macula VD was observed in all three retinal vascular layers of eyes with OHT and pre-POAG compared to controls, indicating localized microvascular changes as early marker in glaucoma pathogenesis.
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Affiliation(s)
- Bettina Hohberger
- Department of Ophthalmology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Marianna Lucio
- Helmholtz Zentrum München - German Research Center for Environmental Health, Research Unit Analytical BioGeoChemistry, Neuherberg, Germany
| | - Sarah Schlick
- Department of Ophthalmology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Antonia Wollborn
- Department of Ophthalmology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Sami Hosari
- Department of Ophthalmology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Christian Mardin
- Department of Ophthalmology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
- * E-mail:
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12
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Lee LL, Khakoo AY, Chintalgattu V. Cardiac pericytes function as key vasoactive cells to regulate homeostasis and disease. FEBS Open Bio 2020; 11:207-225. [PMID: 33135334 PMCID: PMC7780101 DOI: 10.1002/2211-5463.13021] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/24/2020] [Accepted: 10/30/2020] [Indexed: 01/13/2023] Open
Abstract
Pericytes (PCs)—mural cells that envelop endothelial cells (ECs) of microvessels—regulate tissue‐specific vasculature development as well as maturation and maintenance of endothelial barrier integrity. However, little is known about their tissue‐specific function in the heart. Specifically, the mechanism by which cardiac PCs constrict coronary capillaries remains undetermined. To gain insights into the function of cardiac PCs at the cellular level, we isolated NG2+ PDGFRβ+ CD146+ CD34− CD31− CD45− PCs for detailed characterization. Functionally, we provide evidence that these PCs increased transepithelial electrical resistance and decreased endothelial permeability. We show for the first time that this population of PCs express contractile proteins, are stimulated by adrenergic signaling, and demonstrate stereotypical contraction and relaxation. Furthermore, we also studied for the first time, the PCs in in vitro models of disease. PCs in hypoxia activated the hypoxia‐inducible factor 1 alpha pathway, increased secretion of angiogenic factors, and caused cellular apoptosis. Supraphysiological levels of low‐density lipoprotein decreased PC proliferation and induced lipid droplet accumulation. Elevated glucose levels triggered a proinflammatory response. Taken together, our study characterizes cardiac PCs under in vitro disease conditions and supports the hypothesis that cardiac PCs are key vasoactive cells that can regulate blood flow in the heart.
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Affiliation(s)
- Linda L Lee
- Department of Cardiometabolic Disorders, Amgen Research and Discovery, Amgen Inc., South San Francisco, CA, USA
| | - Aarif Y Khakoo
- Department of Drug Development, Calico Labs, South San Francisco, CA, USA
| | - Vishnu Chintalgattu
- Department of Cardiometabolic Disorders, Amgen Research and Discovery, Amgen Inc., South San Francisco, CA, USA
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13
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Kureli G, Yilmaz-Ozcan S, Erdener SE, Donmez-Demir B, Yemisci M, Karatas H, Dalkara T. F-actin polymerization contributes to pericyte contractility in retinal capillaries. Exp Neurol 2020; 332:113392. [DOI: 10.1016/j.expneurol.2020.113392] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/15/2020] [Accepted: 06/25/2020] [Indexed: 01/24/2023]
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14
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Vaeyens MM, Jorge-Peñas A, Barrasa-Fano J, Shapeti A, Roeffaers M, Van Oosterwyck H. Actomyosin-dependent invasion of endothelial sprouts in collagen. Cytoskeleton (Hoboken) 2020; 77:261-276. [PMID: 32588525 DOI: 10.1002/cm.21624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/11/2020] [Accepted: 06/22/2020] [Indexed: 12/30/2022]
Abstract
During sprouting angiogenesis-the growth of blood vessels from the existing vasculature-endothelial cells (ECs) adopt an elongated invasive form and exert forces at cell-cell and cell-matrix interaction sites. These cell shape changes and cellular tractions require extensive reorganizations of the actomyosin network. However, the respective roles of actin and myosin for endothelial sprouting are not fully elucidated. In this study, we further investigate these roles by treating 2D-migrating and 3D-sprouting ECs with chemical compounds targeting either myosin or actin. These treatments affected the endothelial cytoskeleton drastically and reduced the invasive response in a compound-specific manner; pointing toward a tight control of the actin and myosin activity during sprouting. Clusters in the data further illustrate that endothelial sprout morphology is sensitive to the in vitro model mechanical microenvironment and directs future research toward mechanical substrate guidance as a strategy for promoting engineered tissue vascularization. In summary, our results add to a growing corpus of research highlighting a key role of the cytoskeleton for sprouting angiogenesis.
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Affiliation(s)
- Marie-Mo Vaeyens
- Biomechanics Section (BMe), Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Alvaro Jorge-Peñas
- Biomechanics Section (BMe), Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Jorge Barrasa-Fano
- Biomechanics Section (BMe), Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Apeksha Shapeti
- Biomechanics Section (BMe), Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Maarten Roeffaers
- Department of Microbial and Molecular Systems (M2S), Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Leuven, Belgium
| | - Hans Van Oosterwyck
- Biomechanics Section (BMe), Department of Mechanical Engineering, KU Leuven, Leuven, Belgium.,Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
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15
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Yu H, Kalogeris T, Korthuis RJ. Reactive species-induced microvascular dysfunction in ischemia/reperfusion. Free Radic Biol Med 2019; 135:182-197. [PMID: 30849489 PMCID: PMC6503659 DOI: 10.1016/j.freeradbiomed.2019.02.031] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 02/26/2019] [Accepted: 02/26/2019] [Indexed: 12/13/2022]
Abstract
Vascular endothelial cells line the inner surface of the entire cardiovascular system as a single layer and are involved in an impressive array of functions, ranging from the regulation of vascular tone in resistance arteries and arterioles, modulation of microvascular barrier function in capillaries and postcapillary venules, and control of proinflammatory and prothrombotic processes, which occur in all segments of the vascular tree but can be especially prominent in postcapillary venules. When tissues are subjected to ischemia/reperfusion (I/R), the endothelium of resistance arteries and arterioles, capillaries, and postcapillary venules become dysfunctional, resulting in impaired endothelium-dependent vasodilator and enhanced endothelium-dependent vasoconstrictor responses along with increased vulnerability to thrombus formation, enhanced fluid filtration and protein extravasation, and increased blood-to-interstitium trafficking of leukocytes in these functionally distinct segments of the microcirculation. The number of capillaries open to flow upon reperfusion also declines as a result of I/R, which impairs nutritive perfusion. All of these pathologic microvascular events involve the formation of reactive species (RS) derived from molecular oxygen and/or nitric oxide. In addition to these effects, I/R-induced RS activate NLRP3 inflammasomes, alter connexin/pannexin signaling, provoke mitochondrial fission, and cause release of microvesicles in endothelial cells, resulting in deranged function in arterioles, capillaries, and venules. It is now apparent that this microvascular dysfunction is an important determinant of the severity of injury sustained by parenchymal cells in ischemic tissues, as well as being predictive of clinical outcome after reperfusion therapy. On the other hand, RS production at signaling levels promotes ischemic angiogenesis, mediates flow-induced dilation in patients with coronary artery disease, and instigates the activation of cell survival programs by conditioning stimuli that render tissues resistant to the deleterious effects of prolonged I/R. These topics will be reviewed in this article.
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Affiliation(s)
- Hong Yu
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Ted Kalogeris
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Ronald J Korthuis
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, 1 Hospital Drive, Columbia, MO 65212, USA; Dalton Cardiovascular Research Center, University of Missouri, 134 Research Park Drive, Columbia, MO 65211, USA.
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16
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Pellowe AS, Sauler M, Hou Y, Merola J, Liu R, Calderon B, Lauridsen HM, Harris MR, Leng L, Zhang Y, Tilstam PV, Pober JS, Bucala R, Lee PJ, Gonzalez AL. Endothelial cell-secreted MIF reduces pericyte contractility and enhances neutrophil extravasation. FASEB J 2019; 33:2171-2186. [PMID: 30252532 PMCID: PMC6338650 DOI: 10.1096/fj.201800480r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/27/2018] [Indexed: 12/14/2022]
Abstract
Dysregulated neutrophil extravasation contributes to the pathogenesis of many inflammatory disorders. Pericytes (PCs) have been implicated in the regulation of neutrophil transmigration, and previous work demonstrates that endothelial cell (EC)-derived signals reduce PC barrier function; however, the signaling mechanisms are unknown. Here, we demonstrate a novel role for EC-derived macrophage migration inhibitory factor (MIF) in inhibiting PC contractility and facilitating neutrophil transmigration. With the use of micro-ELISAs, RNA sequencing, quantitative PCR, and flow cytometry, we found that ECs secrete MIF, and PCs upregulate CD74 in response to TNF-α. We demonstrate that EC-derived MIF decreases PC contractility on 2-dimensional silicone substrates via reduction of phosphorylated myosin light chain. With the use of an in vitro microvascular model of the human EC-PC barrier, we demonstrate that MIF decreases the PC barrier to human neutrophil transmigration by increasing intercellular PC gap formation. For the first time, an EC-specific MIF knockout mouse was used to investigate the effects of selective deletion of EC MIF. In a model of acute lung injury, selective deletion of EC MIF decreases neutrophil infiltration to the bronchoalveolar lavage and tissue and simultaneously decreases PC relaxation by increasing myosin light-chain phosphorylation. We conclude that paracrine signals from EC via MIF decrease PC contraction and enhance PC-regulated neutrophil transmigration.-Pellowe, A. S., Sauler, M., Hou, Y., Merola, J., Liu, R., Calderon, B., Lauridsen, H. M., Harris, M. R., Leng, L., Zhang, Y., Tilstam, P. V., Pober, J. S., Bucala, R., Lee, P. J., Gonzalez, A. L. Endothelial cell-secreted MIF reduces pericyte contractility and enhances neutrophil extravasation.
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Affiliation(s)
- Amanda S. Pellowe
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Maor Sauler
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Yue Hou
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Jonathan Merola
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Rebecca Liu
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Brenda Calderon
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Holly M. Lauridsen
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Mariah R. Harris
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Lin Leng
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Yi Zhang
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Pathricia V. Tilstam
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jordan S. Pober
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Richard Bucala
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Patty J. Lee
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Anjelica L. Gonzalez
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
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17
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Lee LL, Chintalgattu V. Pericytes in the Heart. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1122:187-210. [PMID: 30937870 DOI: 10.1007/978-3-030-11093-2_11] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mural cells known as pericytes envelop the endothelial layer of microvessels throughout the body and have been described to have tissue-specific functions. Cardiac pericytes are abundantly found in the heart, but they are relatively understudied. Currently, their importance is emerging in cardiovascular homeostasis and dysfunction due to their pleiotropism. They are known to play key roles in vascular tone and vascular integrity as well as angiogenesis. However, their dysfunctional presence and/or absence is critical in the mechanisms that lead to cardiac pathologies such as myocardial infarction, fibrosis, and thrombosis. Moreover, they are targeted as a therapeutic potential due to their mesenchymal properties that could allow them to repair and regenerate a damaged heart. They are also sought after as a cell-based therapy based on their healing potential in preclinical studies of animal models of myocardial infarction. Therefore, recognizing the importance of cardiac pericytes and understanding their biology will lead to new therapeutic concepts.
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Affiliation(s)
- Linda L Lee
- Department of CardioMetabolic Disorders, Amgen Research and Discovery, Amgen Inc., South San Francisco, CA, USA
| | - Vishnu Chintalgattu
- Department of CardioMetabolic Disorders, Amgen Research and Discovery, Amgen Inc., South San Francisco, CA, USA.
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18
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Alarcon-Martinez L, Yilmaz-Ozcan S, Yemisci M, Schallek J, Kılıç K, Can A, Di Polo A, Dalkara T. Capillary pericytes express α-smooth muscle actin, which requires prevention of filamentous-actin depolymerization for detection. eLife 2018; 7:e34861. [PMID: 29561727 PMCID: PMC5862523 DOI: 10.7554/elife.34861] [Citation(s) in RCA: 171] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 02/12/2018] [Indexed: 01/12/2023] Open
Abstract
Recent evidence suggests that capillary pericytes are contractile and play a crucial role in the regulation of microcirculation. However, failure to detect components of the contractile apparatus in capillary pericytes, most notably α-smooth muscle actin (α-SMA), has questioned these findings. Using strategies that allow rapid filamentous-actin (F-actin) fixation (i.e. snap freeze fixation with methanol at -20°C) or prevent F-actin depolymerization (i.e. with F-actin stabilizing agents), we demonstrate that pericytes on mouse retinal capillaries, including those in intermediate and deeper plexus, express α-SMA. Junctional pericytes were more frequently α-SMA-positive relative to pericytes on linear capillary segments. Intravitreal administration of short interfering RNA (α-SMA-siRNA) suppressed α-SMA expression preferentially in high order branch capillary pericytes, confirming the existence of a smaller pool of α-SMA in distal capillary pericytes that is quickly lost by depolymerization. We conclude that capillary pericytes do express α-SMA, which rapidly depolymerizes during tissue fixation thus evading detection by immunolabeling.
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Affiliation(s)
- Luis Alarcon-Martinez
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
- Centre de Recherche du Centre Hospitalier de l’Université de MontréalUniversité de Montréal, MontréalQuébecCanada
- Department of NeuroscienceUniversité de Montréal, MontréalQuébecCanada
| | - Sinem Yilmaz-Ozcan
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
| | - Muge Yemisci
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
- Department of NeurologyFaculty of Medicine, Hacettepe UniversityAnkaraTurkey
| | - Jesse Schallek
- Center for Visual ScienceUniversity of RochesterNew YorkUnited States
- Flaum Eye InstituteUniversity of RochesterNew YorkUnited States
| | - Kıvılcım Kılıç
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
| | - Alp Can
- Department of Histology and EmbryologySchool of Medicine, Ankara UniversityAnkaraTurkey
| | - Adriana Di Polo
- Centre de Recherche du Centre Hospitalier de l’Université de MontréalUniversité de Montréal, MontréalQuébecCanada
- Department of NeuroscienceUniversité de Montréal, MontréalQuébecCanada
| | - Turgay Dalkara
- Institute of Neurological Sciences and PsychiatryHacettepe UniversityAnkaraTurkey
- Department of NeurologyFaculty of Medicine, Hacettepe UniversityAnkaraTurkey
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19
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Harrell CR, Simovic Markovic B, Fellabaum C, Arsenijevic A, Djonov V, Volarevic V. Molecular mechanisms underlying therapeutic potential of pericytes. J Biomed Sci 2018; 25:21. [PMID: 29519245 PMCID: PMC5844098 DOI: 10.1186/s12929-018-0423-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 02/21/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Pericytes are multipotent cells present in every vascularized tissue in the body. Despite the fact that they are well-known for more than a century, pericytes are still representing cells with intriguing properties. This is mainly because of their heterogeneity in terms of definition, tissue distribution, origin, phenotype and multi-functional properties. The body of knowledge illustrates importance of pericytes in the regulation of homeostatic and healing processes in the body. MAIN BODY In this review, we summarized current knowledge regarding identification, isolation, ontogeny and functional characteristics of pericytes and described molecular mechanisms involved in the crosstalk between pericytes and endothelial or immune cells. We highlighted the role of pericytes in the pathogenesis of fibrosis, diabetes-related complications (retinopathy, nephropathy, neuropathy and erectile dysfunction), ischemic organ failure, pulmonary hypertension, Alzheimer disease, tumor growth and metastasis with the focus on their therapeutic potential in the regenerative medicine. The functions and capabilities of pericytes are impressive and, as yet, incompletely understood. Molecular mechanisms responsible for pericyte-mediated regulation of vascular stability, angiogenesis and blood flow are well described while their regenerative and immunomodulatory characteristics are still not completely revealed. Strong evidence for pericytes' participation in physiological, as well as in pathological conditions reveals a broad potential for their therapeutic use. Recently published results obtained in animal studies showed that transplantation of pericytes could positively influence the healing of bone, muscle and skin and could support revascularization. However, the differences in their phenotype and function as well as the lack of standardized procedure for their isolation and characterization limit their use in clinical trials. CONCLUSION Critical to further progress in clinical application of pericytes will be identification of tissue specific pericyte phenotype and function, validation and standardization of the procedure for their isolation that will enable establishment of precise clinical settings in which pericyte-based therapy will be efficiently applied.
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Affiliation(s)
- C. Randall Harrell
- Regenerative Processing Plant, LLC, 34176 US Highway 19 N Palm Harbor, Palm Harbor, Florida USA
| | - Bojana Simovic Markovic
- Department of Microbiology and immunology, Center for Molecular Medicine and Stem Cell Research, University of Kragujevac, Serbia, Faculty of Medical Sciences, 69 Svetozar Markovic Street, Kragujevac, 34000 Serbia
| | - Crissy Fellabaum
- Regenerative Processing Plant, LLC, 34176 US Highway 19 N Palm Harbor, Palm Harbor, Florida USA
| | - Aleksandar Arsenijevic
- Department of Microbiology and immunology, Center for Molecular Medicine and Stem Cell Research, University of Kragujevac, Serbia, Faculty of Medical Sciences, 69 Svetozar Markovic Street, Kragujevac, 34000 Serbia
| | - Valentin Djonov
- University of Bern, Institute of Anatomy, Baltzerstrasse 2, Bern, Switzerland
| | - Vladislav Volarevic
- Department of Microbiology and immunology, Center for Molecular Medicine and Stem Cell Research, University of Kragujevac, Serbia, Faculty of Medical Sciences, 69 Svetozar Markovic Street, Kragujevac, 34000 Serbia
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20
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Lacolley P, Regnault V, Segers P, Laurent S. Vascular Smooth Muscle Cells and Arterial Stiffening: Relevance in Development, Aging, and Disease. Physiol Rev 2017; 97:1555-1617. [DOI: 10.1152/physrev.00003.2017] [Citation(s) in RCA: 332] [Impact Index Per Article: 47.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 05/15/2017] [Accepted: 05/26/2017] [Indexed: 12/18/2022] Open
Abstract
The cushioning function of large arteries encompasses distension during systole and recoil during diastole which transforms pulsatile flow into a steady flow in the microcirculation. Arterial stiffness, the inverse of distensibility, has been implicated in various etiologies of chronic common and monogenic cardiovascular diseases and is a major cause of morbidity and mortality globally. The first components that contribute to arterial stiffening are extracellular matrix (ECM) proteins that support the mechanical load, while the second important components are vascular smooth muscle cells (VSMCs), which not only regulate actomyosin interactions for contraction but mediate also mechanotransduction in cell-ECM homeostasis. Eventually, VSMC plasticity and signaling in both conductance and resistance arteries are highly relevant to the physiology of normal and early vascular aging. This review summarizes current concepts of central pressure and tensile pulsatile circumferential stress as key mechanical determinants of arterial wall remodeling, cell-ECM interactions depending mainly on the architecture of cytoskeletal proteins and focal adhesion, the large/small arteries cross-talk that gives rise to target organ damage, and inflammatory pathways leading to calcification or atherosclerosis. We further speculate on the contribution of cellular stiffness along the arterial tree to vascular wall stiffness. In addition, this review provides the latest advances in the identification of gene variants affecting arterial stiffening. Now that important hemodynamic and molecular mechanisms of arterial stiffness have been elucidated, and the complex interplay between ECM, cells, and sensors identified, further research should study their potential to halt or to reverse the development of arterial stiffness.
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Affiliation(s)
- Patrick Lacolley
- INSERM, U1116, Vandœuvre-lès-Nancy, France; Université de Lorraine, Nancy, France; IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium; Department of Pharmacology, European Georges Pompidou Hospital, Assistance Publique Hôpitaux de Paris, France; PARCC INSERM, UMR 970, Paris, France; and University Paris Descartes, Paris, France
| | - Véronique Regnault
- INSERM, U1116, Vandœuvre-lès-Nancy, France; Université de Lorraine, Nancy, France; IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium; Department of Pharmacology, European Georges Pompidou Hospital, Assistance Publique Hôpitaux de Paris, France; PARCC INSERM, UMR 970, Paris, France; and University Paris Descartes, Paris, France
| | - Patrick Segers
- INSERM, U1116, Vandœuvre-lès-Nancy, France; Université de Lorraine, Nancy, France; IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium; Department of Pharmacology, European Georges Pompidou Hospital, Assistance Publique Hôpitaux de Paris, France; PARCC INSERM, UMR 970, Paris, France; and University Paris Descartes, Paris, France
| | - Stéphane Laurent
- INSERM, U1116, Vandœuvre-lès-Nancy, France; Université de Lorraine, Nancy, France; IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium; Department of Pharmacology, European Georges Pompidou Hospital, Assistance Publique Hôpitaux de Paris, France; PARCC INSERM, UMR 970, Paris, France; and University Paris Descartes, Paris, France
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21
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Zeiger AS, Liu FD, Durham JT, Jagielska A, Mahmoodian R, Van Vliet KJ, Herman IM. Static mechanical strain induces capillary endothelial cell cycle re-entry and sprouting. Phys Biol 2016; 13:046006. [PMID: 27526677 DOI: 10.1088/1478-3975/13/4/046006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Vascular endothelial cells are known to respond to a range of biochemical and time-varying mechanical cues that can promote blood vessel sprouting termed angiogenesis. It is less understood how these cells respond to sustained (i.e., static) mechanical cues such as the deformation generated by other contractile vascular cells, cues which can change with age and disease state. Here we demonstrate that static tensile strain of 10%, consistent with that exerted by contractile microvascular pericytes, can directly and rapidly induce cell cycle re-entry in growth-arrested microvascular endothelial cell monolayers. S-phase entry in response to this strain correlates with absence of nuclear p27, a cyclin-dependent kinase inhibitor. Furthermore, this modest strain promotes sprouting of endothelial cells, suggesting a novel mechanical 'angiogenic switch'. These findings suggest that static tensile strain can directly stimulate pathological angiogenesis, implying that pericyte absence or death is not necessarily required of endothelial cell re-activation.
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Affiliation(s)
- A S Zeiger
- Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139. BioSystems & Micromechanics Interdisciplinary Research Group (BioSyM), Singapore-MIT Alliance in Research & Technology (SMART), Singapore 138602
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22
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Bodnar RJ, Satish L, Yates CC, Wells A. Pericytes: A newly recognized player in wound healing. Wound Repair Regen 2016; 24:204-14. [PMID: 26969517 DOI: 10.1111/wrr.12415] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/28/2016] [Indexed: 12/26/2022]
Abstract
Pericytes have generally been considered in the context of stabilizing vessels, ensuring the blood barriers, and regulating the flow through capillaries. However, new reports suggest that pericytes may function at critical times to either drive healing with minimal scarring or, perversely, contribute to fibrosis and ongoing scar formation. Beneficially, pericytes probably drive much of the vascular involution that occurs during the transition from the regenerative to the resolution phases of healing. Pathologically, pericytes can assume a fibrotic phenotype and promote scarring. This perspective will discuss pericyte involvement in wound repair and the relationship pericytes form with the parenchymal cells of the skin. We will further evaluate the role pericytes may have in disease progression in relation to chronic wounds and fibrosis.
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Affiliation(s)
- Richard J Bodnar
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania.,McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania.,Veterans Affairs Medical Center, Pittsburgh, Pennsylvania
| | - Latha Satish
- McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania.,Department of Plastic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Cecelia C Yates
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania.,McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania.,Veterans Affairs Medical Center, Pittsburgh, Pennsylvania.,Department of Health Promotions and Development, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Alan Wells
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania.,McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania.,Veterans Affairs Medical Center, Pittsburgh, Pennsylvania
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23
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Wouters OY, Ploeger DTA, van Putten SM, Bank RA. 3,4-Dihydroxy-L-Phenylalanine as a Novel Covalent Linker of Extracellular Matrix Proteins to Polyacrylamide Hydrogels with a Tunable Stiffness. Tissue Eng Part C Methods 2016; 22:91-101. [PMID: 26779898 DOI: 10.1089/ten.tec.2015.0312] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cells acquire mechanical information from their surrounding and convert this into biochemical activity. The concept and mechanism behind this cellular mechanosensing and mechanotransduction are often studied by means of two-dimensional hydrogels. Polyacrylamide hydrogels (PAAMs) offer chemical, mechanical, and optical advantages but due to their inert surface do not allow protein and cell adherence. Several cross-linkers have been used to functionalize the surface of PAAMs with extracellular matrix (ECM) proteins to enable cell culture. However, the most commonly used cross-linkers are either unstable, expensive, or laborious and often show heterogeneous coating or require PAAM modification. Here, we introduce 3,4-dihydroxy-l-phenylalanine (L-DOPA) as a novel cross-linker that can functionalize PAAMs with ECM without the above-mentioned disadvantages. A homogenous collagen type I and fibronectin coating was observed after L-DOPA functionalization. Fibroblasts responded to differences in PAAMs' stiffness; morphology, cell area, and protein localization were all affected as expected, in accordance with literature where other cross-linkers were used. In conclusion, L-DOPA can be used as a cross-linker between PAAMs and ECM and represents a novel, straightforward, nonlaborious, and robust method to functionalize PAAMs for cell culture to study cell mechanosensing.
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Affiliation(s)
- Olaf Y Wouters
- 1 Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands
| | - Diana T A Ploeger
- 1 Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands
| | - Sander M van Putten
- 1 Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands .,2 Synvolux Therapeutics , Groningen, The Netherlands
| | - Ruud A Bank
- 1 Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands
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24
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Durham JT, Dulmovits BM, Cronk SM, Sheets AR, Herman IM. Pericyte chemomechanics and the angiogenic switch: insights into the pathogenesis of proliferative diabetic retinopathy? Invest Ophthalmol Vis Sci 2015; 56:3441-59. [PMID: 26030100 DOI: 10.1167/iovs.14-13945] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To establish the regulatory roles that pericytes have in coordinating retinal endothelial cell (EC) growth and angiogenic potential. METHODS Pericytes were derived from donor diabetic (DHuRP) or normal (NHuRP) human retinae, and characterized using vascular markers, coculture, contraction, morphogenesis, and proliferation assays. To investigate capillary "cross-talk," pericyte-endothelial coculture growth, and connexin-43 (Cx43) expression assays were performed. Paracrine effects were examined via treating EC with pericyte-derived conditioned media (CM) in proliferation, angiogenesis, and angiocrine assays. The effects of sphingosine 1-phosphate (S1P) were assessed using receptor antagonists. RESULTS The DHuRP exhibit unique proliferative and morphologic properties, reflecting distinctive cytoskeletal and isoactin expression patterns. Unlike NHuRP, DHuRP are unable to sustain EC growth arrest in coculture and display reduced Cx43 expression. Further, CM from DHuRP (DPCM) markedly stimulates EC proliferation and tube formation. Treatment with S1P receptor antagonists mitigates DPCM growth-promotion in EC and S1P-mediated pericyte contraction. Angiocrine assays on normal and diabetic pericyte secretomes reveal factors involved in angiogenic control, inflammation, and metabolism. CONCLUSIONS Effects from the diabetic microenvironment appear sustainable in cell culture: pericytes derived from diabetic donor eyes seemingly possess a "metabolic memory" in vitro, which may be linked to original donor health status. Diabetes- and pericyte-dependent effects on EC growth and angiogenesis may reflect alterations in bioactive lipid, angiocrine, and chemomechanical signaling. Altogether, our results suggest that diabetes alters pericyte contractile phenotype and cytoskeletal signaling, which ultimately may serve as a key, initiating event required for retinal endothelial reproliferation, angiogenic activation, and the pathological neovascularization accompanying proliferative diabetic retinopathy.
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25
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Kent D. The stereotypical molecular cascade in neovascular age-related macular degeneration: the role of dynamic reciprocity. Eye (Lond) 2015; 29:1416-26. [PMID: 26228288 DOI: 10.1038/eye.2015.140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 06/22/2015] [Indexed: 12/15/2022] Open
Abstract
This review summarises our current understanding of the molecular basis of subretinal neovascularisation (SRNV) in age-related macular degeneration (AMD). The term neovascular AMD (NVAMD) is derived from the dominant early clinical features of haemorrhage, fluid, and lipid in the subretinal space (SRS) and the historical role of fluorescein angiography in detecting the presence of NV tissue. However, at the cellular level, SRNV resembles an aberrant but stereotypical tissue repair response that incorporates both an early inflammatory phase and a late fibrotic phase in addition to the neovascular (NV) component that dominates the early clinical presentation. This review will seek not only to highlight the important molecules involved in each of these components but to demonstrate that the development of SRNV has its origins in the earliest events in non-NV AMD pathogenesis. Current evidence suggests that this early-stage pathogenesis is characterised by complement-mediated immune dysregulation, leading to a state of chronic inflammation in the retinal pigment epithelium/Bruch's membrane/choriocapillaris complex. These initial events can be seamlessly and inextricably linked to late-stage development of SRNV in AMD by the process of dynamic reciprocity (DyR), the ongoing bidirectional communication between cells, and their surrounding matrix. Moreover, this correlation between disease onset and eventual outcome is reflected in the temporal and spatial correlation between chronic inflammation, NV, and fibrosis within the reparative microenvironment of the SRS. In summary, the downstream consequences of the earliest dysfunctional molecular events in AMD can result in the late-stage entity we recognize clinically as SRNV and is characterized by a spectrum of predictable, related, and stereotypical processes referred to as DyR.
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Affiliation(s)
- D Kent
- The Vision Clinic, Kilkenny, Ireland.,Faculty of Health and Life Sciences, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
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26
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Roy S, Bae E, Amin S, Kim D. Extracellular matrix, gap junctions, and retinal vascular homeostasis in diabetic retinopathy. Exp Eye Res 2015; 133:58-68. [PMID: 25819455 DOI: 10.1016/j.exer.2014.08.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 08/19/2014] [Accepted: 08/20/2014] [Indexed: 12/15/2022]
Abstract
The vascular basement membrane (BM) contains extracellular matrix (ECM) proteins that assemble in a highly organized manner to form a supportive substratum for cell attachment facilitating myriad functions that are vital to cell survival and overall retinal homeostasis. The BM provides a microenvironment in which bidirectional signaling through integrins regulates cell attachment, turnover, and functionality. In diabetic retinopathy, the BM undergoes profound structural and functional changes, and recent studies have brought to light the implications of such changes. Thickened vascular BM in the retinal capillaries actively participate in the development and progression of characteristic changes associated with diabetic retinopathy. High glucose (HG)-induced compromised cell-cell communication via gap junctions (GJ) in retinal vascular cells may disrupt homeostasis in the retinal microenvironment. In this review, the role of altered ECM synthesis, compromised GJ activity, and disturbed retinal homeostasis in the development of retinal vascular lesions in diabetic retinopathy are discussed.
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Affiliation(s)
- Sayon Roy
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA; Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA.
| | - Edward Bae
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA; Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA
| | - Shruti Amin
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA; Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA
| | - Dongjoon Kim
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA; Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA
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Kelly-Goss MR, Sweat RS, Stapor PC, Peirce SM, Murfee WL. Targeting pericytes for angiogenic therapies. Microcirculation 2015; 21:345-57. [PMID: 24267154 DOI: 10.1111/micc.12107] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/19/2013] [Indexed: 12/18/2022]
Abstract
In pathological scenarios, such as tumor growth and diabetic retinopathy, blocking angiogenesis would be beneficial. In others, such as myocardial infarction and hypertension, promoting angiogenesis might be desirable. Due to their putative influence on endothelial cells, vascular pericytes have become a topic of growing interest and are increasingly being evaluated as a potential target for angioregulatory therapies. The strategy of manipulating pericyte recruitment to capillaries could result in anti- or proangiogenic effects. Our current understanding of pericytes, however, is limited by knowledge gaps regarding pericyte identity and lineage. To use a music analogy, this review is a "mash-up" that attempts to integrate what we know about pericyte functionality and expression with what is beginning to be elucidated regarding their regenerative potential. We explore the lingering questions regarding pericyte phenotypic identity and lineage. The expression of different pericyte markers (e.g., SMA, Desmin, NG2, and PDGFR-β) varies for different subpopulations and tissues. Previous use of these markers to identify pericytes has suggested potential phenotypic overlaps and plasticity toward other cell phenotypes. Our review chronicles the state of the literature, identifies critical unanswered questions, and motivates future research aimed at understanding this intriguing cell type and harnessing its therapeutic potential.
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Affiliation(s)
- Molly R Kelly-Goss
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
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Durham JT, Surks HK, Dulmovits BM, Herman IM. Pericyte contractility controls endothelial cell cycle progression and sprouting: insights into angiogenic switch mechanics. Am J Physiol Cell Physiol 2014; 307:C878-92. [PMID: 25143350 DOI: 10.1152/ajpcell.00185.2014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Microvascular stability and regulation of capillary tonus are regulated by pericytes and their interactions with endothelial cells (EC). While the RhoA/Rho kinase (ROCK) pathway has been implicated in modulation of pericyte contractility, in part via regulation of the myosin light chain phosphatase (MLCP), the mechanisms linking Rho GTPase activity with actomyosin-based contraction and the cytoskeleton are equivocal. Recently, the myosin phosphatase-RhoA-interacting protein (MRIP) was shown to mediate the RhoA/ROCK-directed MLCP inactivation in vascular smooth muscle. Here we report that MRIP directly interacts with the β-actin-specific capping protein βcap73. Furthermore, manipulation of MRIP expression influences pericyte contractility, with MRIP silencing inducing cytoskeletal remodeling and cellular hypertrophy. MRIP knockdown induces a repositioning of βcap73 from the leading edge to stress fibers; thus MRIP-silenced pericytes increase F-actin-driven cell spreading twofold. These hypertrophied and cytoskeleton-enriched pericytes demonstrate a 2.2-fold increase in contractility upon MRIP knockdown when cells are plated on a deformable substrate. In turn, silencing pericyte MRIP significantly affects EC cycle progression and angiogenic activation. When MRIP-silenced pericytes are cocultured with capillary EC, there is a 2.0-fold increase in EC cycle entry. Furthermore, in three-dimensional models of injury and repair, silencing pericyte MRIP results in a 1.6-fold elevation of total tube area due to EC network formation and increased angiogenic sprouting. The pivotal role of MRIP expression in governing pericyte contractile phenotype and endothelial growth should lend important new insights into how chemomechanical signaling pathways control the "angiogenic switch" and pathological angiogenic induction.
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Affiliation(s)
- Jennifer T Durham
- Graduate Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Department of Developmental, Molecular, and Chemical Biology, Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, Boston, Massachusetts
| | - Howard K Surks
- Graduate Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Department of Developmental, Molecular, and Chemical Biology, Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, Boston, Massachusetts
| | - Brian M Dulmovits
- Graduate Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Department of Developmental, Molecular, and Chemical Biology, Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, Boston, Massachusetts
| | - Ira M Herman
- Graduate Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Department of Developmental, Molecular, and Chemical Biology, Center for Innovations in Wound Healing Research, School of Medicine, Tufts University, Boston, Massachusetts
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29
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Martinelli R, Zeiger AS, Whitfield M, Sciuto TE, Dvorak A, Van Vliet KJ, Greenwood J, Carman CV. Probing the biomechanical contribution of the endothelium to lymphocyte migration: diapedesis by the path of least resistance. J Cell Sci 2014; 127:3720-34. [PMID: 25002404 DOI: 10.1242/jcs.148619] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Immune cell trafficking requires the frequent breaching of the endothelial barrier either directly through individual cells ('transcellular' route) or through the inter-endothelial junctions ('paracellular' route). What determines the loci or route of breaching events is an open question with important implications for overall barrier regulation. We hypothesized that basic biomechanical properties of the endothelium might serve as crucial determinants of this process. By altering junctional integrity, cytoskeletal morphology and, consequently, local endothelial cell stiffness of different vascular beds, we could modify the preferred route of diapedesis. In particular, high barrier function was associated with predominantly transcellular migration, whereas negative modulation of junctional integrity resulted in a switch to paracellular diapedesis. Furthermore, we showed that lymphocytes dynamically probe the underlying endothelium by extending invadosome-like protrusions (ILPs) into its surface that deform the nuclear lamina, distort actin filaments and ultimately breach the barrier. Fluorescence imaging and pharmacologic depletion of F-actin demonstrated that lymphocyte barrier breaching efficiency was inversely correlated with local endothelial F-actin density and stiffness. Taken together, these data support the hypothesis that lymphocytes are guided by the mechanical 'path of least resistance' as they transverse the endothelium, a process we term 'tenertaxis'.
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Affiliation(s)
- Roberta Martinelli
- Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA Department of Cell Biology, Institute of Ophthalmology, UCL, 11-43 Bath Street, London EC1V 9EL, UK
| | - Adam S Zeiger
- Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew Whitfield
- Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tracey E Sciuto
- Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Ann Dvorak
- Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Krystyn J Van Vliet
- Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - John Greenwood
- Department of Cell Biology, Institute of Ophthalmology, UCL, 11-43 Bath Street, London EC1V 9EL, UK
| | - Christopher V Carman
- Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
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Stapor PC, Sweat RS, Dashti DC, Betancourt AM, Murfee WL. Pericyte dynamics during angiogenesis: new insights from new identities. J Vasc Res 2014; 51:163-74. [PMID: 24853910 DOI: 10.1159/000362276] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 03/11/2014] [Indexed: 12/13/2022] Open
Abstract
Therapies aimed at manipulating the microcirculation require the ability to control angiogenesis, defined as the sprouting of new capillaries from existing vessels. Blocking angiogenesis would be beneficial in many pathologies (e.g. cancer, retinopathies and rheumatoid arthritis). In others (e.g. myocardial infarction, stroke and hypertension), promoting angiogenesis would be desirable. We know that vascular pericytes elongate around endothelial cells (ECs) and are functionally associated with regulating vessel stabilization, vessel diameter and EC proliferation. During angiogenesis, bidirectional pericyte-EC signaling is critical for capillary sprout formation. Observations of pericytes leading capillary sprouts also implicate their role in EC guidance. As such, pericytes have recently emerged as a therapeutic target to promote or inhibit angiogenesis. Advancing our basic understanding of pericytes and developing pericyte-related therapies are challenged, like in many other fields, by questions regarding cell identity. This review article discusses what we know about pericyte phenotypes and the opportunity to advance our understanding by defining the specific pericyte cell populations involved in capillary sprouting.
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Affiliation(s)
- Peter C Stapor
- Department of Biomedical Engineering, Tulane University, Lindy Boggs Center, New Orleans, La., USA
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31
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Jamison J, Wang JHC, Wells A. PKCδ regulates force signaling during VEGF/CXCL4 induced dissociation of endothelial tubes. PLoS One 2014; 9:e93968. [PMID: 24699667 PMCID: PMC3974837 DOI: 10.1371/journal.pone.0093968] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 03/12/2014] [Indexed: 12/26/2022] Open
Abstract
Wound healing requires the vasculature to re-establish itself from the severed ends; endothelial cells within capillaries must detach from neighboring cells before they can migrate into the nascent wound bed to initiate angiogenesis. The dissociation of these endothelial capillaries is driven partially by platelets' release of growth factors and cytokines, particularly the chemokine CXCL4/platelet factor-4 (PF4) that increases cell-cell de-adherence. As this retraction is partly mediated by increased transcellular contractility, the protein kinase c-δ/myosin light chain-2 (PKCδ/MLC-2) signaling axis becomes a candidate mechanism to drive endothelial dissociation. We hypothesize that PKCδ activation induces contractility through MLC-2 to promote dissociation of endothelial cords after exposure to platelet-released CXCL4 and VEGF. To investigate this mechanism of contractility, endothelial cells were allowed to form cords following CXCL4 addition to perpetuate cord dissociation. In this study, CXCL4-induced dissociation was reduced by a VEGFR inhibitor (sunitinib malate) and/or PKCδ inhibition. During combined CXCL4+VEGF treatment, increased contractility mediated by MLC-2 that is dependent on PKCδ regulation. As cellular force is transmitted to focal adhesions, zyxin, a focal adhesion protein that is mechano-responsive, was upregulated after PKCδ inhibition. This study suggests that growth factor regulation of PKCδ may be involved in CXCL4-mediated dissociation of endothelial cords.
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Affiliation(s)
- Joshua Jamison
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - James H-C. Wang
- Department of Orthopedic Surgery, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Alan Wells
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Ezquer F, Ezquer M, Arango-Rodriguez M, Conget P. Could donor multipotent mesenchymal stromal cells prevent or delay the onset of diabetic retinopathy? Acta Ophthalmol 2014; 92:e86-95. [PMID: 23773776 DOI: 10.1111/aos.12113] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Diabetes mellitus is a complex metabolic disease that has become a global epidemic with more than 285 million cases worldwide. Major medical advances over the past decades have substantially improved its management, extending patients' survival. The latter is accompanied by an increased risk of developing chronic macro- and microvascular complications. Amongst them, diabetic retinopathy (DR) is the most common and frightening. Furthermore, during the past two decades, it has become the leading cause of visual loss. Irrespective of the type of diabetes, DR follows a well-known clinical and temporal course characterized by pericytes and neuronal cell loss, formation of acellular-occluded capillaries, occasional microaneurysms, increased leucostasis and thickening of the vascular basement membrane. These alterations progressively affect the integrity of retinal microvessels, leading to the breakdown of the blood-retinal barrier, widespread haemorrhage and neovascularization. Finally, tractional retinal detachment occurs leading to blindness. Nowadays, there is growing evidence that local inflammation and oxidative stress play pivotal roles in the pathogenesis of DR. Both processes have been associated with pericytes and neuronal degeneration observed early during DR progression. They may also be linked to sustained retinal vasculature damage that results in abnormal neovascularization. Currently, DR therapeutic options depend on highly invasive surgical procedures performed only at advanced stages of the disease, and which have proved to be ineffective to restore visual acuity. Therefore, the availability of less invasive and more effective strategies aimed to prevent or delay the onset of DR is highly desirable. Multipotent mesenchymal stromal cells, also referred to as mesenchymal stem cells (MSCs), are promising healing agents as they contribute to tissue regeneration by pleiotropic mechanisms, with no evidence of significant adverse events. Here, we revise the pathophysiology of DR to identify therapeutic targets for donor MSCs. Also, we discuss whether an MSC-based therapy could prevent or delay the onset of DR.
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Affiliation(s)
- Fernando Ezquer
- Institute of Science, Faculty of Medicine Clinica Alemana Universidad del Desarrollo, Lo Barnechea, Santiago, Chile
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33
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Mechanical Cues Direct Focal Adhesion Dynamics. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 126:103-34. [DOI: 10.1016/b978-0-12-394624-9.00005-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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34
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Kelly-Goss MR, Sweat RS, Azimi MS, Murfee WL. Vascular islands during microvascular regression and regrowth in adult networks. Front Physiol 2013; 4:108. [PMID: 23720632 PMCID: PMC3655287 DOI: 10.3389/fphys.2013.00108] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 04/27/2013] [Indexed: 11/30/2022] Open
Abstract
Objective: Angiogenesis is the growth of new vessels from pre-existing vessels and commonly associated with two modes: capillary sprouting and capillary splitting. Previous work by our laboratory suggests vascular island incorporation might be another endothelial cell dynamic involved in microvascular remodeling. Vascular islands are defined as endothelial cell segments disconnected from nearby networks, but their origin remains unclear. The objective of this study was to determine whether vascular islands associated with microvascular regression are involved in network regrowth. Methods: Mesenteric tissues were harvested from adult male Wistar rats according to the experimental groups: unstimulated, post stimulation (10 and 70 days), and 70 days post stimulation + restimulation (3 and 10 days). Stimulation was induced by mast cell degranulation via intraperitoneal injections of compound 48/80. Tissues were immunolabeled for PECAM (endothelial cells), neuron-glial antigen 2 (NG2) (pericytes), collagen IV (basement membrane), and BrdU (proliferation). Results: Percent vascular area per tissue area and length density increased by day 10 post stimulation compared to the unstimulated group. At day 70, vascular area and length density were then decreased, indicating vascular regression compared to the day 10 levels. The number of vascular islands at day 10 post stimulation was dramatically reduced compared to the unstimulated group. During regression at day 70, the number of islands increased. The disconnected endothelial cells were commonly bridged to surrounding networks by collagen IV labeling. NG2-positive pericytes were observed both along the islands and the collagen IV tracks. At 3 days post restimulation, vascular islands contained BrdU-positive cells. By day 10 post restimulation, when vascular area and length density were again increased, and the number of vascular islands was dramatically reduced. Conclusion: The results suggest that vascular islands originating during microvascular regression are capable of undergoing proliferation and incorporation into nearby networks during network regrowth.
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Affiliation(s)
- Molly R Kelly-Goss
- Department of Biomedical Engineering, Tulane University New Orleans, LA, USA
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35
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Taddei ML, Giannoni E, Comito G, Chiarugi P. Microenvironment and tumor cell plasticity: an easy way out. Cancer Lett 2013; 341:80-96. [PMID: 23376253 DOI: 10.1016/j.canlet.2013.01.042] [Citation(s) in RCA: 177] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 01/23/2013] [Accepted: 01/24/2013] [Indexed: 12/12/2022]
Abstract
Cancer cells undergo genetic changes allowing their adaptation to environmental changes, thereby obtaining an advantage during the long metastatic route, disseminated of several changes in the surrounding environment. In particular, plasticity in cell motility, mainly due to epigenetic regulation of cancer cells by environmental insults, engage adaptive strategies aimed essentially to survive in hostile milieu, thereby escaping adverse sites. This review is focused on tumor microenvironment as a collection of structural and cellular elements promoting plasticity and adaptive programs. We analyze the role of extracellular matrix stiffness, hypoxia, nutrient deprivation, acidity, as well as different cell populations of tumor microenvironment.
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Affiliation(s)
- Maria Letizia Taddei
- Department of Biochemical Sciences, University of Florence, Viale Morgagni 50, 50134 Firenze, Italy
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36
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McGrail DJ, McAndrews KM, Dawson MR. Biomechanical analysis predicts decreased human mesenchymal stem cell function before molecular differences. Exp Cell Res 2012; 319:684-96. [PMID: 23228958 DOI: 10.1016/j.yexcr.2012.11.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 11/19/2012] [Accepted: 11/22/2012] [Indexed: 12/13/2022]
Abstract
Multipotent human mesenchymal stem cells (hMSCs) are uniquely suited for the growing field of regenerative medicine due to their ease of isolation, expansion, and transplantation. However, during ex vivo expansion necessary to obtain clinically relevant cell quantities, hMSCs undergo fundamental changes culminating in cellular senescence. The molecular changes as hMSCs transition into senescence have been well characterized, but few studies have focused on the mechanical properties that govern many processes necessary for therapeutic efficacy. We show that before detectable differences in classical senescence markers emerge, single-cell mechanical and cytoskeletal properties reveal a subpopulation of 'non-functioning' hMSCs that appears after even limited expansion. This subpopulation, characterized by a loss of dynamic cytoskeletal stiffening and morphological flexibility in response to chemotactic signals grows with extended culture resulting in overall decreased hMSC motility and ability to contract collagen gels. These changes were mitigated with cytoskeletal inhibition. Finally, a xenographic wound healing model was used to demonstrate that these in vitro differences correlate with decreased ability of hMSCs to aid in wound closure in vivo. These data illustrate the importance of analyzing not only the molecular markers, but also mechanical markers of hMSCs as they are investigated for potential therapeutics.
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Affiliation(s)
- Daniel J McGrail
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, United States
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37
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Dulmovits BM, Herman IM. Microvascular remodeling and wound healing: a role for pericytes. Int J Biochem Cell Biol 2012; 44:1800-12. [PMID: 22750474 DOI: 10.1016/j.biocel.2012.06.031] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 12/20/2022]
Abstract
Physiologic wound healing is highly dependent on the coordinated functions of vascular and non-vascular cells. Resolution of tissue injury involves coagulation, inflammation, formation of granulation tissue, remodeling and scarring. Angiogenesis, the growth of microvessels the size of capillaries, is crucial for these processes, delivering blood-borne cells, nutrients and oxygen to actively remodeling areas. Central to angiogenic induction and regulation is microvascular remodeling, which is dependent upon capillary endothelial cell and pericyte interactions. Despite our growing knowledge of pericyte-endothelial cell crosstalk, it is unclear how the interplay among pericytes, inflammatory cells, glia and connective tissue elements shape microvascular injury response. Here, we consider the relationships that pericytes form with the cellular effectors of healing in normal and diabetic environments, including repair following injury and vascular complications of diabetes, such as diabetic macular edema and proliferative diabetic retinopathy. In addition, pericytes and stem cells possessing "pericyte-like" characteristics are gaining considerable attention in experimental and clinical efforts aimed at promoting healing or eradicating ocular vascular proliferative disorders. As the origin, identification and characterization of microvascular pericyte progenitor populations remains somewhat ambiguous, the molecular markers, structural and functional characteristics of pericytes will be briefly reviewed.
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Affiliation(s)
- Brian M Dulmovits
- Sackler School of Graduate Biomedical Sciences Program in Cellular and Molecular Physiology, Department of Molecular Physiology and Pharmacology and the Center for Innovation in Wound Healing Research, Tufts University, 150 Harrison Avenue, Boston, MA 02111, USA
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Microcapillary-like structures prompted by phospholipase A2 activation in endothelial cells and pericytes co-cultures on a polyhydroxymethylsiloxane thin film. Biochimie 2012; 94:1860-70. [PMID: 22575274 DOI: 10.1016/j.biochi.2012.04.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 04/24/2012] [Indexed: 01/04/2023]
Abstract
A thin film of poly(hydroxymethylsiloxane) (PHMS) has been deposited on glass dishes and tested as artificial support material for vascularization from mixed cultures of endothelial cells (EC) and pericytes (PC). The EC/PC co-cultures adhered massively on PHMS, with the formation of net-like microcapillary structures. Such evidence was not found on control glass substrates in the same co-culture conditions neither on PHMS for EC and PC in monocultures. The physicochemical characterization of PHMS and control glass surface by time-of-flight secondary ion mass spectrometry, X-ray photoelectron spectroscopy, water contact angle and atomic force microscopy, pointed to the main role of the polymer hydrophobilicy to explain the observed cellular behavior. Moreover, enhanced intercellular cross-talk was evidenced by the up-regulation and activation of cytoplasmic and Ca(2+)-independent phospholipase A(2) (cPLA(2) and iPLA(2)) expression and cPLA(2) phosphorylation, leading to the cell proliferation and microcapillary formation on the PHMS surface, as evidenced by confocal microscopy analyses. Co-cultures, established with growth-arrested PCs by treatment with mitomycin C, showed an increase in EC proliferation on PHMS. AACOCF(3) or co-transfection with cPLA(2) and iPLA(2)siRNA reduced cell proliferation. The results highlight the major role played by EC/PC cross-talk as well as the hydrophobic character of the substrate surface, to promote microcapillary formation. Our findings suggest an attractive strategy for vascular tissue engineering and provide new details on the interplay of artificial substrates and capillary formation.
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Chen P, Jiang L, Han D. In situ imaging of multiphase bio-interfaces at the micro-/nanoscale. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2011; 7:2825-2835. [PMID: 21932246 DOI: 10.1002/smll.201100039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 04/04/2011] [Indexed: 05/31/2023]
Abstract
The multiphase bio-interfacial system constituted by biological surfaces and their surrounding environment is usually considered to be an essential clue for exploring the mysterious relationship between surface architecture and function. As a visualizing method to understand these systems, in situ imaging of multiphase interfaces (e.g., air/liquid/solid and oil/water/solid systems) at the micro-/nanoscale, still remains a huge challenge, as a result of their heterogeneity and complexity. Here, recent progress on real-space micro-/nanoscale imaging of multiphase bio-interfacial systems is reviewed; this includes several techniques and imaging results on bio-interfaces, such as the lotus leaf, fish scale, living cell's surface, and fresh tissue surface. The results evidently show that interfacial structures have a significant impact on the state of the microscopic multiphase interface, further influencing specific functions. Based on this research, technical innovations, some more complicated multiphase interface systems, and structure-function coupling mechanism are proposed.
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Affiliation(s)
- Peipei Chen
- National Center for Nanoscience and Technology, Beijing, People's Republic of China
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40
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Abstract
Patients struggling with diabetes are at elevated risks for several sight-threatening diseases, including proliferative diabetic retinopathy (DR). DR manifests in two stages: first, the retinal microvasculature is compromised and capillary degeneration occurs; subsequently, an over-compensatory angiogenic response is initiated. Early changes in the retinal microcirculation include disruptions in blood flow, thickening of basement membrane, eventual loss of mural cells, and the genesis of acellular capillaries. Endothelial apoptosis and capillary dropout lead to a hypoxic inner retina, alterations in growth factors, and upregulation of inflammatory mediators. With disease progression, pathologic angiogenesis generates abnormal preretinal microvessels. Current therapies, which include panretinal photocoagulation and vitrectomy, have remained unaltered for several decades. With several exciting preclinical advances, emergent technologies and innovative cellular targets may offer newfound hope for developing "next-generation" interventional or preventive clinical approaches that will significantly advance current standards of care and clinical outcomes.
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Affiliation(s)
- Jennifer T Durham
- Sackler School of Graduate Biomedical Sciences, Program in Cellular and Molecular Physiology, Department of Molecular Physiology and Pharmacology and the Center for Innovation in Wound Healing Research, Tufts University, 150 Harrison Avenue, Boston, MA 02111, USA.
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41
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Schultz GS, Davidson JM, Kirsner RS, Bornstein P, Herman IM. Dynamic reciprocity in the wound microenvironment. Wound Repair Regen 2011; 19:134-48. [PMID: 21362080 DOI: 10.1111/j.1524-475x.2011.00673.x] [Citation(s) in RCA: 308] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Here, we define dynamic reciprocity (DR) as an ongoing, bidirectional interaction among cells and their surrounding microenvironment. In this review, we posit that DR is especially meaningful during wound healing as the DR-driven biochemical, biophysical, and cellular responses to injury play pivotal roles in regulating tissue regenerative responses. Such cell-extracellular matrix interactions not only guide and regulate cellular morphology, but also cellular differentiation, migration, proliferation, and survival during tissue development, including, e.g., embryogenesis, angiogenesis, as well as during pathologic processes including cancer, diabetes, hypertension, and chronic wound healing. Herein, we examine DR within the wound microenvironment while considering specific examples across acute and chronic wound healing. This review also considers how a number of hypotheses that attempt to explain chronic wound pathophysiology may be understood within the DR framework. The implications of applying the principles of DR to optimize wound care practice and future development of innovative wound healing therapeutics are also briefly considered.
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Affiliation(s)
- Gregory S Schultz
- Department of Obstetrics and Gynecology, University of Florida, Gainesville, Florida, USA
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Menon S, Beningo KA. Cancer cell invasion is enhanced by applied mechanical stimulation. PLoS One 2011; 6:e17277. [PMID: 21359145 PMCID: PMC3040771 DOI: 10.1371/journal.pone.0017277] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Accepted: 01/27/2011] [Indexed: 02/04/2023] Open
Abstract
Metastatic cells migrate from the site of the primary tumor, through the stroma, into the blood and lymphatic vessels, finally colonizing various other tissues to form secondary tumors. Numerous studies have been done to identify the stimuli that drive the metastatic cascade. This has led to the identification of multiple biochemical signals that promote metastasis. However, information on the role of mechanical factors in cancer metastasis has been limited to the affect of compliance. Interestingly, the tumor microenvironment is rich in many cell types including highly contractile cells that are responsible for extensive remodeling and production of the dense extracellular matrix surrounding the cancerous tissue. We hypothesize that the mechanical forces produced by remodeling activities of cells in the tumor microenvironment contribute to the invasion efficiency of metastatic cells. We have discovered a significant difference in the extent of invasion in mechanically stimulated verses non-stimulated cell culture environments. Furthermore, this mechanically enhanced invasion is dependent upon substrate protein composition, and influenced by topography. Finally, we have found that the protein cofilin is needed to sense the mechanical stimuli that enhances invasion. We conclude that other types of mechanical signals in the tumor microenvironment, besides the rigidity, can enhance the invasive abilities of cancer cells in vitro. We further propose that in vivo, non-cancerous cells located within the tumor micro-environment may be capable of providing the necessary mechanical stimulus during the remodeling of the extracellular matrix surrounding the tumor.
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Affiliation(s)
- Shalini Menon
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America
| | - Karen A. Beningo
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America
- * E-mail:
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Maloney JM, Nikova D, Lautenschläger F, Clarke E, Langer R, Guck J, Van Vliet KJ. Mesenchymal stem cell mechanics from the attached to the suspended state. Biophys J 2011; 99:2479-87. [PMID: 20959088 DOI: 10.1016/j.bpj.2010.08.052] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 08/18/2010] [Accepted: 08/20/2010] [Indexed: 01/01/2023] Open
Abstract
Human mesenchymal stem cells (hMSCs) are therapeutically useful cells that are typically expanded in vitro on stiff substrata before reimplantation. Here we explore MSC mechanical and structural changes via atomic force microscopy and optical stretching during extended passaging, and we demonstrate that cytoskeletal organization and mechanical stiffness of attached MSC populations are strongly modulated over >15 population doublings in vitro. Cytoskeletal actin networks exhibit significant coarsening, attendant with decreasing average mechanical compliance and differentiation potential of these cells, although expression of molecular surface markers does not significantly decline. These mechanical changes are not observed in the suspended state, indicating that the changes manifest themselves as alterations in stress fiber arrangement rather than cortical cytoskeleton arrangement. Additionally, optical stretching is capable of investigating a previously unquantified structural transition: remodeling-induced stiffening over tens of minutes after adherent cells are suspended. Finally, we find that optically stretched hMSCs exhibit power-law rheology during both loading and recovery; this evidence appears to be the first to originate from a biophysical measurement technique not involving cell-probe or cell-substratum contact. Together, these quantitative assessments of attached and suspended MSCs define the extremes of the extracellular environment while probing intracellular mechanisms that contribute to cell mechanical response.
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Affiliation(s)
- John M Maloney
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, USA
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Kotecki M, Zeiger AS, Van Vliet K, Herman IM. Calpain- and talin-dependent control of microvascular pericyte contractility and cellular stiffness. Microvasc Res 2010; 80:339-48. [PMID: 20709086 PMCID: PMC2981705 DOI: 10.1016/j.mvr.2010.07.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 07/26/2010] [Accepted: 07/30/2010] [Indexed: 01/09/2023]
Abstract
Pericytes surround capillary endothelial cells and exert contractile forces modulating microvascular tone and endothelial growth. We previously described pericyte contractile phenotype to be Rho GTPase- and α-smooth muscle actin (αSMA)-dependent. However, mechanisms mediating adhesion-dependent shape changes and contractile force transduction remain largely equivocal. We now report that the neutral cysteine protease, calpain, modulates pericyte contractility and cellular stiffness via talin, an integrin-binding and F-actin associating protein. Digital imaging and quantitative analyses of living cells reveal significant perturbations in contractile force transduction detected via deformation of silicone substrata, as well as perturbations of mechanical stiffness in cellular contractile subdomains quantified via atomic force microscope (AFM)-enabled nanoindentation. Pericytes overexpressing GFP-tagged talin show significantly enhanced contractility (~two-fold), which is mitigated when either the calpain-cleavage resistant mutant talin L432G or vinculin are expressed. Moreover, the cell-penetrating, calpain-specific inhibitor termed CALPASTAT reverses talin-enhanced, but not Rho GTP-dependent, contractility. Interestingly, our analysis revealed that CALPASTAT, but not its inactive mutant, alters contractile cell-driven substrata deformations while increasing mechanical stiffness of subcellular contractile regions of these pericytes. Altogether, our results reveal that calpain-dependent cleavage of talin modulates cell contractile dynamics, which in pericytes may prove instrumental in controlling normal capillary function or microvascular pathophysiology.
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Affiliation(s)
- Maciej Kotecki
- Department of Physiology, and The Center for Innovations in Wound Healing Research, Tufts University School of Medicine, 150 Harrison Avenue, Boston, MA 02111 USA
| | - Adam S. Zeiger
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 USA
| | - Krystyn Van Vliet
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 USA
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 USA
| | - Ira M. Herman
- Department of Physiology, and The Center for Innovations in Wound Healing Research, Tufts University School of Medicine, 150 Harrison Avenue, Boston, MA 02111 USA
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