51
|
Rossi E, Smadja DM, Boscolo E, Langa C, Arevalo MA, Pericacho M, Gamella-Pozuelo L, Kauskot A, Botella LM, Gaussem P, Bischoff J, Lopez-Novoa JM, Bernabeu C. Endoglin regulates mural cell adhesion in the circulatory system. Cell Mol Life Sci 2016; 73:1715-39. [PMID: 26646071 PMCID: PMC4805714 DOI: 10.1007/s00018-015-2099-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 02/06/2023]
Abstract
The circulatory system is walled off by different cell types, including vascular mural cells and podocytes. The interaction and interplay between endothelial cells (ECs) and mural cells, such as vascular smooth muscle cells or pericytes, play a pivotal role in vascular biology. Endoglin is an RGD-containing counter-receptor for β1 integrins and is highly expressed by ECs during angiogenesis. We find that the adhesion between vascular ECs and mural cells is enhanced by integrin activators and inhibited upon suppression of membrane endoglin or β1-integrin, as well as by addition of soluble endoglin (SolEng), anti-integrin α5β1 antibody or an RGD peptide. Analysis of different endoglin mutants, allowed the mapping of the endoglin RGD motif as involved in the adhesion process. In Eng (+/-) mice, a model for hereditary hemorrhagic telangectasia type 1, endoglin haploinsufficiency induces a pericyte-dependent increase in vascular permeability. Also, transgenic mice overexpressing SolEng, an animal model for preeclampsia, show podocyturia, suggesting that SolEng is responsible for podocytes detachment from glomerular capillaries. These results suggest a critical role for endoglin in integrin-mediated adhesion of mural cells and provide a better understanding on the mechanisms of vessel maturation in normal physiology as well as in pathologies such as preeclampsia or hereditary hemorrhagic telangiectasia.
Collapse
MESH Headings
- Animals
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Cell Adhesion/physiology
- Cell Line, Tumor
- Disease Models, Animal
- Endoglin
- Endothelium, Vascular/metabolism
- Female
- Human Umbilical Vein Endothelial Cells/metabolism
- Humans
- Integrin beta1/genetics
- Jurkat Cells
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Nude
- Mice, Transgenic
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/metabolism
- Neovascularization, Pathologic/metabolism
- Pericytes/metabolism
- Podocytes/metabolism
- Pre-Eclampsia/genetics
- Pre-Eclampsia/pathology
- Pregnancy
- Protein Binding
- RNA Interference
- RNA, Small Interfering
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Retina/metabolism
- Telangiectasia, Hereditary Hemorrhagic/genetics
- Telangiectasia, Hereditary Hemorrhagic/pathology
Collapse
Affiliation(s)
- Elisa Rossi
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), c/Ramiro de Maeztu 9, 28040, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040, Madrid, Spain
- Paris Descartes University, Sorbonne Paris Cite, Paris, France
- Hematology Department, AP-HP, Hôpital Européen Georges Pompidou, Paris, France
| | - David M Smadja
- Hematology Department, AP-HP, Hôpital Européen Georges Pompidou, Paris, France
- Faculté de Pharmacie, Inserm UMR-S1140, Paris, France
| | - Elisa Boscolo
- Department of Surgery, Harvard Medical School, Children's Hospital, Boston, MA, 02115, USA
| | - Carmen Langa
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), c/Ramiro de Maeztu 9, 28040, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040, Madrid, Spain
| | - Miguel A Arevalo
- Departamento de Anatomía e Histología Humanas, Facultad de Medicina, Universidad de Salamanca, 37007, Salamanca, Spain
- Instituto de Investigaciones Biomédicas de Salamanca (IBSAL), 37007, Salamanca, Spain
| | - Miguel Pericacho
- Instituto de Investigaciones Biomédicas de Salamanca (IBSAL), 37007, Salamanca, Spain
- Departamento de Fisiología y Farmacología, Unidad de Fisiopatología Renal y Cardiovascular, Universidad de Salamanca, 37007, Salamanca, Spain
| | - Luis Gamella-Pozuelo
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), c/Ramiro de Maeztu 9, 28040, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040, Madrid, Spain
- Departamento de Fisiología y Farmacología, Unidad de Fisiopatología Renal y Cardiovascular, Universidad de Salamanca, 37007, Salamanca, Spain
| | - Alexandre Kauskot
- Inserm UMR-S1176, Le Kremlin Bicêtre, Paris, France
- Université Paris Sud, Le Kremlin Bicêtre, Paris, France
| | - Luisa M Botella
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), c/Ramiro de Maeztu 9, 28040, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040, Madrid, Spain
| | - Pascale Gaussem
- Hematology Department, AP-HP, Hôpital Européen Georges Pompidou, Paris, France
- Faculté de Pharmacie, Inserm UMR-S1140, Paris, France
| | - Joyce Bischoff
- Department of Surgery, Harvard Medical School, Children's Hospital, Boston, MA, 02115, USA
| | - José M Lopez-Novoa
- Instituto de Investigaciones Biomédicas de Salamanca (IBSAL), 37007, Salamanca, Spain
- Departamento de Fisiología y Farmacología, Unidad de Fisiopatología Renal y Cardiovascular, Universidad de Salamanca, 37007, Salamanca, Spain
| | - Carmelo Bernabeu
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), c/Ramiro de Maeztu 9, 28040, Madrid, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28040, Madrid, Spain.
| |
Collapse
|
52
|
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.
Collapse
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
| |
Collapse
|
53
|
Ma Z, Shou K, Li Z, Jian C, Qi B, Yu A. Negative pressure wound therapy promotes vessel destabilization and maturation at various stages of wound healing and thus influences wound prognosis. Exp Ther Med 2016; 11:1307-1317. [PMID: 27073441 PMCID: PMC4812564 DOI: 10.3892/etm.2016.3083] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/20/2016] [Indexed: 12/14/2022] Open
Abstract
Negative pressure wound therapy (NPWT) has been observed to accelerate the wound healing process in humans through promoting angiogenesis. However, the potential biological effect and relevant molecular mechanisms, including microvessel destabilization, regression and endothelial cell proliferation in the early stage (1–3 days), and the neovascular stabilization and maturation in the later stage (7–15 days), have yet to be fully elucidated. The current study aimed to research the potential effect of NPWT on angiogenesis and vessel maturation, and investigate relevant association between mature microvessels and wound prognosis, as well as the regulatory mechanisms in human wound healing. Patients in the present study (n=48) were treated with NPWT or a petrolatum gauze, and relevant growth factors and vessel changes were detected using various experimental methods. NPWT increased the expression levels of angiogenin-2 (Ang-2), and decreased the expression levels of Ang-1 and ratios of Ang-1/Ang-2 in the initial stages of wound healing. However, in the latter stages of wound healing, NPWT increased the expression levels of Ang-1 and ratios of Ang-1/Ang-2, as well as the phosphorylation level of tyrosine kinase receptor-2. Consequently, microvessel pericyte coverage was gradually elevated, and the basement membrane was gradually supplied with new blood at the later stage of wound healing. In conclusion, NPWT may preferentially stimulate microvessel destabilization and regression in the early stage of wound healing, and as a consequence, increase angiogenesis. Subsequently, in the later stage of wound healing, NPWT may preferentially promote microvessel stabilization, thereby promoting microvessel maturation in human wounds through the angiogenin/tyrosine kinase receptor-2 signaling pathway. The results of the present study results demonstrated that NPWT was able to accelerate wound healing speed, and thus influence wound prognosis, as a result of an abundance of mature microvessels in human wounds.
Collapse
Affiliation(s)
- Zhanjun Ma
- Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Kangquan Shou
- Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Zonghuan Li
- Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Chao Jian
- Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Baiwen Qi
- Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Aixi Yu
- Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| |
Collapse
|
54
|
Wells A, Nuschke A, Yates CC. Skin tissue repair: Matrix microenvironmental influences. Matrix Biol 2015; 49:25-36. [PMID: 26278492 DOI: 10.1016/j.matbio.2015.08.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 08/11/2015] [Accepted: 08/12/2015] [Indexed: 12/31/2022]
Abstract
The process of repair of wounded skin involves intricate orchestration not only between the epidermal and dermal compartments but also between the resident and immigrant cells and the local microenvironment. Only now are we beginning to appreciate the complex roles played by the matrix in directing the outcome of the repair processes, and how this impacts the signals from the various cells. Recent findings speak of dynamic and reciprocal interactions that occurs among the matrix, growth factors, and cells that underlies this integrated process. Further confounding this integration are the physiologic and pathologic situations that directly alter the matrix to impart at least part of the dysrepair that occurs. These topics will be discussed with a call for innovative model systems of direct relevance to the human situation.
Collapse
Affiliation(s)
- Alan Wells
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213 USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213 USA; McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15213 USA.
| | - Austin Nuschke
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213 USA; McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15213 USA
| | - Cecelia C Yates
- Department of Health Development and Promotion, University of Pittsburgh, Pittsburgh, PA 15213 USA; McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15213 USA
| |
Collapse
|
55
|
Barbe L, Alini M, Verrier S, Herrmann M. In Vitro Models to Mimic the Endothelial Barrier. Altern Lab Anim 2015; 43:P34-6. [PMID: 26256399 DOI: 10.1177/026119291504300314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Microfluidic technologies permit the replication in vitro of geometrical features essential for the homeostasis of all vascularised tissues in vivo, including the contribution of pericytes to the endothelial barrier
Collapse
Affiliation(s)
| | - Mauro Alini
- AO Research Institute, Davos Platz, Switzerland
| | | | | |
Collapse
|
56
|
Combined effects of pericytes in the tumor microenvironment. Stem Cells Int 2015; 2015:868475. [PMID: 26000022 PMCID: PMC4427118 DOI: 10.1155/2015/868475] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 02/28/2015] [Indexed: 12/25/2022] Open
Abstract
Pericytes are multipotent perivascular cells whose involvement in vasculature development is well established. Evidences in the literature also suggest that pericytes display immune properties and that these cells may serve as an in vivo reservoir of stem cells, contributing to the regeneration of diverse tissues. Pericytes are also capable of tumor homing and are important cellular components of the tumor microenvironment (TME). In this review, we highlight the contribution of pericytes to some classical hallmarks of cancer, namely, tumor angiogenesis, growth, metastasis, and evasion of immune destruction, and discuss how collectively these hallmarks could be tackled by therapies targeting pericytes, providing a rationale for cancer drugs aiming at the TME.
Collapse
|
57
|
Zhang J, Chen S, Hou Z, Cai J, Dong M, Shi X. Lipopolysaccharide-induced middle ear inflammation disrupts the cochlear intra-strial fluid-blood barrier through down-regulation of tight junction proteins. PLoS One 2015; 10:e0122572. [PMID: 25815897 PMCID: PMC4376743 DOI: 10.1371/journal.pone.0122572] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 02/16/2015] [Indexed: 12/20/2022] Open
Abstract
Middle ear infection (or inflammation) is the most common pathological condition that causes fluid to accumulate in the middle ear, disrupting cochlear homeostasis. Lipopolysaccharide, a product of bacteriolysis, activates macrophages and causes release of inflammatory cytokines. Many studies have shown that lipopolysaccharides cause functional and structural changes in the inner ear similar to that of inflammation. However, it is specifically not known how lipopolysaccharides affect the blood-labyrinth barrier in the stria vascularis (intra-strial fluid–blood barrier), nor what the underlying mechanisms are. In this study, we used a cell culture-based in vitro model and animal-based in vivo model, combined with immunohistochemistry and a vascular leakage assay, to investigate lipopolysaccharide effects on the integrity of the mouse intra-strial fluid–blood barrier. Our results show lipopolysaccharide-induced local infection significantly affects intra-strial fluid–blood barrier component cells. Pericytes and perivascular-resident macrophage-like melanocytes are particularly affected, and the morphological and functional changes in these cells are accompanied by substantial changes in barrier integrity. Significant vascular leakage is found in the lipopolysaccharide treated-animals. Consistent with the findings from the in vivo animal model, the permeability of the endothelial cell monolayer to FITC-albumin was significantly higher in the lipopolysaccharide-treated monolayer than in an untreated endothelial cell monolayer. Further study has shown the lipopolysaccharide-induced inflammation to have a major effect on the expression of tight junctions in the blood barrier. Lipopolysaccharide was also shown to cause high frequency hearing loss, corroborated by previous reports from other laboratories. Our findings show lipopolysaccharide-evoked middle ear infection disrupts inner ear fluid balance, and its particular effects on the intra-strial fluid–blood barrier, essential for cochlear homeostasis. The barrier is degraded as the expression of tight junction-associated proteins such as zona occludens 1, occludin, and vascular endothelial cadherin are down-regulated.
Collapse
Affiliation(s)
- Jinhui Zhang
- Department of Otolaryngology/Head and Neck Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Oregon Hearing Research Center, Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Songlin Chen
- Oregon Hearing Research Center, Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Zhiqiang Hou
- Oregon Hearing Research Center, Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Jing Cai
- Oregon Hearing Research Center, Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Mingmin Dong
- Department of Otolaryngology/Head and Neck Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xiaorui Shi
- Oregon Hearing Research Center, Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
| |
Collapse
|
58
|
Structural changes in thestrial blood-labyrinth barrier of aged C57BL/6 mice. Cell Tissue Res 2015; 361:685-96. [PMID: 25740201 DOI: 10.1007/s00441-015-2147-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/17/2014] [Indexed: 12/20/2022]
Abstract
Tight control over cochlear blood flow (CoBF) and the blood-labyrinth barrier (BLB) in the striavascularis is critical for maintaining the ionic, fluid and energy balance necessary for hearing function. Inefficient CoBF and disruption of BLB integrity have long been considered major etiologic factors in a variety of hearing disorders. In this study, we investigate structural changes in the BLB of the striavascularis in age-graded C57BL/6 mice (1 to 21 months) with a focus on changes in two blood barrier accessory cells, namely pericytes (PCs) and perivascular-resident macrophage-like melanocytes (PVM/Ms). Decreased capillary density was detectable at 6 months, with significant capillary degeneration seen in 9- to 21-month-old mice. Reduced capillary density was highly correlated with lower numbers of PCs and PVM/Ms. "Drop-out" of PCs and "activation" of PVM/Ms were seen at 6 months, with drastic changes being observed by 21 months. With newly established in vitro three-dimensional cell-based co-culture models, we demonstrate that PCs and PVM/Ms are essential for maintaining cochlear vascular architecture and stability.
Collapse
|
59
|
Trembley MA, Velasquez LS, de Mesy Bentley KL, Small EM. Myocardin-related transcription factors control the motility of epicardium-derived cells and the maturation of coronary vessels. Development 2015; 142:21-30. [PMID: 25516967 DOI: 10.1242/dev.116418] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
An important pool of cardiovascular progenitor cells arises from the epicardium, a single layer of mesothelium lining the heart. Epicardium-derived progenitor cell (EPDC) formation requires epithelial-to-mesenchymal transition (EMT) and the subsequent migration of these cells into the sub-epicardial space. Although some of the physiological signals that promote EMT are understood, the functional mediators of EPDC motility and differentiation are not known. Here, we identify a novel regulatory mechanism of EPDC mobilization. Myocardin-related transcription factor (MRTF)-A and MRTF-B (MKL1 and MKL2, respectively) are enriched in the perinuclear space of epicardial cells during development. Transforming growth factor (TGF)-β signaling and disassembly of cell contacts leads to nuclear accumulation of MRTFs and the activation of the motile gene expression program. Conditional ablation of Mrtfa and Mrtfb specifically in the epicardium disrupts cell migration and leads to sub-epicardial hemorrhage, partially stemming from the depletion of coronary pericytes. Using lineage-tracing analyses, we demonstrate that sub-epicardial pericytes arise from EPDCs in a process that requires the MRTF-dependent motile gene expression program. These findings provide novel mechanisms linking EPDC motility and differentiation, shed light on the transcriptional control of coronary microvascular maturation and suggest novel therapeutic strategies to manipulate epicardium-derived progenitor cells for cardiac repair.
Collapse
Affiliation(s)
- Michael A Trembley
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA
| | - Lissette S Velasquez
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA
| | - Karen L de Mesy Bentley
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA
| | - Eric M Small
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA
| |
Collapse
|
60
|
Chamberlain MD, West MED, Lam GC, Sefton MV. In vivo remodelling of vascularizing engineered tissues. Ann Biomed Eng 2014; 43:1189-200. [PMID: 25297985 DOI: 10.1007/s10439-014-1146-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 09/27/2014] [Indexed: 12/15/2022]
Abstract
A critical aspect of creating vascularized tissues is the remodelling that occurs in vivo, driven in large part by the host response to the tissue construct. Rather than a simple inflammatory response, a beneficial tissue remodelling response results in the formation of vascularised tissue. The characteristics and dynamics of this response are slowly being elucidated, especially as they are modulated by the complex interaction between the biomaterial and cellular components of the tissue constructs and the host. This process has elements that are similar to both wound healing and tumour development, and its features are illustrated by reference to the bottom-up generation of a tissue using modular constructs. These modular constructs consist of mesenchymal stromal cells (MSC) embedded in endothelial cell (EC)-covered collagen gel rods that are a few hundred microns in size. Particular attention is paid to the role of hypoxia and macrophage recruitment, as well as the paracrine effects of the MSC and EC in this host response.
Collapse
Affiliation(s)
- M Dean Chamberlain
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College St., Toronto, ON, M5S 3G9, Canada
| | | | | | | |
Collapse
|
61
|
Rao VR, Ruiz AP, Prasad VR. Viral and cellular factors underlying neuropathogenesis in HIV associated neurocognitive disorders (HAND). AIDS Res Ther 2014; 11:13. [PMID: 24894206 PMCID: PMC4043700 DOI: 10.1186/1742-6405-11-13] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 05/08/2014] [Indexed: 11/11/2022] Open
Abstract
As the HIV-1 epidemic enters its fourth decade, HIV-1 associated neurological disorders (HAND) continue to be a major concern in the infected population, despite the widespread use of anti-retroviral therapy. Advancing age and increased life expectancy of the HIV-1 infected population have been shown to increase the risk of cognitive dysfunction. Over the past 10 years, there has been a significant progress in our understanding of the mechanisms and the risk factors involved in the development of HAND. Key events that lead up to neuronal damage in HIV-1 infected individuals can be categorized based on the interaction of HIV-1 with the various cell types, including but not limited to macrophages, brain endothelial cells, microglia, astrocytes and the neurons. This review attempts to decipher these interactions, beginning with HIV-1 infection of macrophages and ultimately resulting in the release of neurotoxic viral and host products. These include: interaction with endothelial cells, resulting in the impairment of the blood brain barrier; interaction with the astrocytes, leading to metabolic and neurotransmitter imbalance; interactions with resident immune cells in the brain, leading to release of toxic cytokines and chemokines. We also review the mechanisms underlying neuronal damage caused by the factors mentioned above. We have attempted to bring together recent findings in these areas to help appreciate the viral and host factors that bring about neurological dysfunction. In addition, we review host factors and viral genotypic differences that affect phenotypic pathological outcomes, as well as recent advances in treatment options to specifically address the neurotoxic mechanisms in play.
Collapse
|