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Duan LJ, Jiang Y, Fong GH. Endothelial HIF2α suppresses retinal angiogenesis in neonatal mice by upregulating NOTCH signaling. Development 2024; 151:dev202802. [PMID: 38770916 PMCID: PMC11190433 DOI: 10.1242/dev.202802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/01/2024] [Indexed: 05/22/2024]
Abstract
Prolyl hydroxylase domain (PHD) proteins are oxygen sensors that use intracellular oxygen as a substrate to hydroxylate hypoxia-inducible factor (HIF) α proteins, routing them for polyubiquitylation and proteasomal degradation. Typically, HIFα accumulation in hypoxic or PHD-deficient tissues leads to upregulated angiogenesis. Here, we report unexpected retinal phenotypes associated with endothelial cell (EC)-specific gene targeting of Phd2 (Egln1) and Hif2alpha (Epas1). EC-specific Phd2 disruption suppressed retinal angiogenesis, despite HIFα accumulation and VEGFA upregulation. Suppressed retinal angiogenesis was observed both in development and in the oxygen-induced retinopathy (OIR) model. On the other hand, EC-specific deletion of Hif1alpha (Hif1a), Hif2alpha, or both did not affect retinal vascular morphogenesis. Strikingly, retinal angiogenesis appeared normal in mice double-deficient for endothelial PHD2 and HIF2α. In PHD2-deficient retinal vasculature, delta-like 4 (DLL4, a NOTCH ligand) and HEY2 (a NOTCH target) were upregulated by HIF2α-dependent mechanisms. Inhibition of NOTCH signaling by a chemical inhibitor or DLL4 antibody partially rescued retinal angiogenesis. Taken together, our data demonstrate that HIF2α accumulation in retinal ECs inhibits rather than stimulates retinal angiogenesis, in part by upregulating DLL4 expression and NOTCH signaling.
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Affiliation(s)
- Li-Juan Duan
- Center for Vascular Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Yida Jiang
- Center for Vascular Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Guo-Hua Fong
- Center for Vascular Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
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2
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Lin WC, Jordan BK, Scottoline B, Ostmo SR, Coyner AS, Singh P, Kalpathy-Cramer J, Erdogmus D, Chan RP, Chiang MF, Campbell JP. Oxygenation Fluctuations Associated with Severe Retinopathy of Prematurity: Insights from a Multimodal Deep Learning Approach. OPHTHALMOLOGY SCIENCE 2024; 4:100417. [PMID: 38059124 PMCID: PMC10696464 DOI: 10.1016/j.xops.2023.100417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 09/27/2023] [Accepted: 10/18/2023] [Indexed: 12/08/2023]
Abstract
Purpose Retinopathy of prematurity (ROP) is one of the leading causes of blindness in children. Although the role of oxygen in the pathophysiology of ROP is well established, a precise understanding of the dynamic relationship between oxygen exposure ROP incidence and severity is lacking. The purpose of this study was to evaluate the correlation between time-dependent oxygen variables and the onset of ROP. Design Retrospective cohort study. Participants Two hundred thirty infants who were born at a single academic center and met the inclusion criteria were included. Infants are mainly born between January 2011 and October 2022. Methods Patient data were extracted from electronic health records (EHRs), with sufficient time-dependent oxygen data. Clinical outcomes for ROP were recorded as none/mild or moderate/severe (defined as type II or worse). Mixed-effects linear models were used to compare the 2 groups in terms of dynamic oxygen variables, such as daily average and the coefficient of variation (COV) fraction of inspired oxygen (FiO2). Support vector machine (SVM) and long-short-term memory (LSTM)-based multimodal models were trained with fivefold cross-validation to predict which infants would develop moderate/severe ROP. Gestational age (GA), birth weight, and time-dependent oxygen variables were used to develop predictive models. Main Outcome Measures Model cross-validation performance was evaluated by computing the mean area under the receiver operating characteristic (AUROC) curve, precision, recall, and F1 score. Results We found that both daily average and COV of FiO2 were associated with more severe ROP (adjusted P < 0.001). With fivefold cross-validation, the multimodal LSTM models had higher performance than the best static models (SVM using GA and 3 average FiO2 features) and SVM models trained on GA alone (mean AUROC = 0.89 ± 0.04 vs. 0.86 ± 0.05 vs. 0.83 ± 0.04). Conclusions The development of severe ROP might not only be influenced by oxygen exposure but also by its fluctuation, which provides direction for future study of pathophysiological factors associated with severe ROP development. Additionally, we demonstrated that multimodal neural networks can be a method to extract useful information from time-series data, which may be a valuable methodology for the investigation of other diseases using EHR data. Financial Disclosures Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Wei-Chun Lin
- Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon
| | - Brian K. Jordan
- Department of Neonatology, Oregon Health and Science University, Portland, Oregon
| | - Brian Scottoline
- Department of Neonatology, Oregon Health and Science University, Portland, Oregon
| | - Susan R. Ostmo
- Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon
| | - Aaron S. Coyner
- Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon
| | - Praveer Singh
- Department of Ophthalmology, University of Colorado (CU) School of Medicine, Denver, Colorado
| | | | - Deniz Erdogmus
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts
| | - R.V. Paul Chan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois
| | - Michael F. Chiang
- National Eye Institute, National Institutes of Health, Bethesda, Maryland
- National Library of Medicine, National Institutes of Health, Bethesda, Maryland
| | - J. Peter Campbell
- Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon
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3
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Chen X, Sun X, Ge Y, Zhou X, Chen JF. Targeting adenosine A 2A receptors for early intervention of retinopathy of prematurity. Purinergic Signal 2024:10.1007/s11302-024-09986-x. [PMID: 38329708 DOI: 10.1007/s11302-024-09986-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/16/2024] [Indexed: 02/09/2024] Open
Abstract
Retinopathy of prematurity (ROP) continues to pose a significant threat to the vision of numerous children worldwide, primarily owing to the increased survival rates of premature infants. The pathologies of ROP are mainly linked to impaired vascularization as a result of hyperoxia, leading to subsequent neovascularization. Existing treatments, including anti-vascular endothelial growth factor (VEGF) therapies, have thus far been limited to addressing pathological angiogenesis at advanced ROP stages, inevitably leading to adverse side effects. Intervention to promote physiological angiogenesis during the initial stages could hold the potential to prevent ROP. Adenosine A2A receptors (A2AR) have been identified in various ocular cell types, exhibiting distinct densities and functionally intricate connections with oxygen metabolism. In this review, we discuss experimental evidence that strongly underscores the pivotal role of A2AR in ROP. In particular, A2AR blockade may represent an effective treatment strategy, mitigating retinal vascular loss by reversing hyperoxia-mediated cellular proliferation inhibition and curtailing hypoxia-mediated neovascularization in oxygen-induced retinopathy (OIR). These effects stem from the interplay of endothelium, neuronal and glial cells, and novel molecular pathways (notably promoting TGF-β signaling) at the hyperoxia phase. We propose that pharmacological targeting of A2AR signaling may confer an early intervention for ROP with distinct therapeutic benefits and mechanisms than the anti-VEGF therapy.
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Affiliation(s)
- Xuhao Chen
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Xiaoting Sun
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Yuanyuan Ge
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Xuzhao Zhou
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China.
| | - Jiang-Fan Chen
- The Molecular Neuropharmacology Laboratory and the Eye-Brain Research Center, The State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China.
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, China.
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Derbyshire ML, Akula S, Wong A, Rawlins K, Voura EB, Brunken WJ, Zuber ME, Fuhrmann S, Moon AM, Viczian AS. Loss of Tbx3 in Mouse Eye Causes Retinal Angiogenesis Defects Reminiscent of Human Disease. Invest Ophthalmol Vis Sci 2023; 64:1. [PMID: 37126314 PMCID: PMC10155871 DOI: 10.1167/iovs.64.5.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Purpose Familial exudative vitreoretinopathy (FEVR) and Norrie disease are examples of genetic disorders in which the retinal vasculature fails to fully form (hypovascular), leading to congenital blindness. While studying the role of a factor expressed during retinal development, T-box factor Tbx3, we discovered that optic cup loss of Tbx3 caused the retina to become hypovascular. The purpose of this study was to characterize how loss of Tbx3 affects retinal vasculature formation. Methods Conditional removal of Tbx3 from both retinal progenitors and astrocytes was done using the optic cup-Cre recombinase driver BAC-Dkk3-Cre and was analyzed using standard immunohistochemical techniques. Results With Tbx3 loss, the retinas were hypovascular, as seen in patients with retinopathy of prematurity (ROP) and FEVR. Retinal vasculature failed to form the stereotypic tri-layered plexus in the dorsal-temporal region. Astrocyte precursors were reduced in number and failed to form a lattice at the dorsal-temporal edge. We next examined retinal ganglion cells, as they have been shown to play a critical role in retinal angiogenesis. We found that melanopsin expression and Islet1/2-positive retinal ganglion cells were reduced in the dorsal half of the retina. In previous studies, the loss of melanopsin has been linked to hyaloid vessel persistence, which we also observed in the Tbx3 conditional knockout (cKO) retinas, as well as in infants with ROP or FEVR. Conclusions To the best of our knowledge, these studies are the first demonstration that Tbx3 is required for normal mammalian eye formation. Together, the results provide a potential genetic model for retinal hypovascular diseases.
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Affiliation(s)
- Mark L Derbyshire
- Ophthalmology and Visual Sciences Department, Upstate Medical University, Syracuse, New York, United States
- College of Medicine, Upstate Medical University, Syracuse, New York, United States
| | - Sruti Akula
- Ophthalmology and Visual Sciences Department, Upstate Medical University, Syracuse, New York, United States
- College of Medicine, Upstate Medical University, Syracuse, New York, United States
| | - Austin Wong
- Ophthalmology and Visual Sciences Department, Upstate Medical University, Syracuse, New York, United States
- College of Medicine, Upstate Medical University, Syracuse, New York, United States
| | - Karisa Rawlins
- Ophthalmology and Visual Sciences Department, Upstate Medical University, Syracuse, New York, United States
| | - Evelyn B Voura
- Ophthalmology and Visual Sciences Department, Upstate Medical University, Syracuse, New York, United States
| | - William J Brunken
- Ophthalmology and Visual Sciences Department, Upstate Medical University, Syracuse, New York, United States
| | - Michael E Zuber
- Ophthalmology and Visual Sciences Department, Upstate Medical University, Syracuse, New York, United States
| | - Sabine Fuhrmann
- Ophthalmology and Visual Sciences Department, Vanderbilt Eye Institute, Vanderbilt University, Nashville, Tennessee, United States
| | - Anne M Moon
- Department of Molecular and Functional Genomics, Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States
- The Mindich Child Health and Development Institute, Hess Center for Science and Medicine at Mount Sinai, New York, New York, United States
| | - Andrea S Viczian
- Ophthalmology and Visual Sciences Department, Upstate Medical University, Syracuse, New York, United States
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Jin Z, Guo Q, Wang Z, Wu X, Hu W, Li J, Li H, Zhu S, Zhang H, Chen Z, Xu H, Shi L, Yang L, Wang Y. Andrographolide suppresses hypoxia-induced embryonic hyaloid vascular system development through HIF-1a/VEGFR2 signaling pathway. Front Cardiovasc Med 2023; 10:1090938. [PMID: 36844722 PMCID: PMC9944699 DOI: 10.3389/fcvm.2023.1090938] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 01/04/2023] [Indexed: 02/11/2023] Open
Abstract
Introduction Ocular abnormalities and the development of retinal vasculature may cause postnatal retinopathy. In the past decade, tremendous progress has been made in identifying the mechanisms that regulate retina vasculature. However, the means of regulating embryonic hyaloid vasculature development is largely unknown. This study aims to determine whether and how andrographolide regulates embryonic hyaloid vasculature development. Methods Murine embryonic retinas were used in this study. Whole mount isolectin B4 (IB4) staining, hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and immunofluorescence staining (IF) were performed to determine whether andrographolide is critical for embryonic hyaloid vasculature development. BrdU incorporation assay, Boyden chamber migration assay, spheroid sprouting assay, and Matrigel-based tube formation assay were performed to evaluate whether andrographolide regulates the proliferation and migration of vascular endothelial cells. Molecular docking simulation and Co-immunoprecipitation assay were used to observe protein interaction. Results Hypoxia conditions exist in murine embryonic retinas. Hypoxia induces HIF-1a expression; high-expressed HIF-1a interacts with VEGFR2, resulting in the activation of the VEGF signaling pathway. Andrographolide suppresses hypoxia-induced HIF-1a expression and, at least in part, interrupts the interaction between HIF-1a and VEGFR2, causing inhibiting endothelial proliferation and migration, eventually inhibiting embryonic hyaloid vasculature development. Conclusion Our data demonstrated that andrographolide plays a critical role in regulating embryonic hyaloid vasculature development.
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Affiliation(s)
- Zhong Jin
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Qiru Guo
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Zheng Wang
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiao Wu
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Wangming Hu
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jiali Li
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Hongfei Li
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Song Zhu
- Chengdu University of Traditional Chinese Medicine, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Haidi Zhang
- Chengdu University of Traditional Chinese Medicine, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Zixian Chen
- School of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Huan Xu
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Liangqin Shi
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Lan Yang
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yong Wang
- College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Yong Wang, ✉ ; ✉
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Duan LJ, Jiang Y, Shi Y, Fong GH. Tailless and hypoxia inducible factor-2α cooperate to sustain proangiogenic states of retinal astrocytes in neonatal mice. Biol Open 2023; 12:286421. [PMID: 36625299 PMCID: PMC9867894 DOI: 10.1242/bio.059684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 10/31/2022] [Indexed: 01/11/2023] Open
Abstract
Tailless (TLX, an orphan nuclear receptor) and hypoxia inducible factor-2α (HIF2α) are both essential for retinal astrocyte and vascular development. Tlx-/- mutation and astrocyte specific Hif2α disruption in Hif2αf/f/GFAPCre mice are known to cause defective astrocyte development and block vascular development in neonatal retinas. Here we report that TLX and HIF2α support retinal angiogenesis by cooperatively maintaining retinal astrocytes in their proangiogenic states. While Tlx+/- and Hif2αf/+/GFAPCre mice are phenotypically normal, Tlx+/-/Hif2αf/+/GFAPCre mice display precocious retinal astrocyte differentiation towards non-angiogenic states, along with significantly reduced retinal angiogenesis. In wild-type mice, TLX and HIF2α coexist in the same protein complex, suggesting a cooperative function under physiological conditions. Furthermore, astrocyte specific disruption of Phd2 (prolyl hydroxylase domain protein 2), a manipulation previously shown to cause HIF2α accumulation, did not rescue retinal angiogenesis in Tlx-/- background, which suggests functional dependence of HIF2α on TLX. Finally, the expression of fibronectin and VEGF-A is significantly reduced in retinal astrocytes of neonatal Tlx+/-/Hif2αf/+/GFAPCre mice. Overall, these data indicate that TLX and HIF2α cooperatively support retinal angiogenesis by maintaining angiogenic potential of retinal astrocytes.
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Affiliation(s)
- Li-Juan Duan
- Center for Vascular Biology, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Yida Jiang
- Center for Vascular Biology, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA,Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Yanhong Shi
- Department of Stem Cell Biology and Regenerative Medicine, City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Guo-Hua Fong
- Center for Vascular Biology, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA,Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA,Author for correspondence ()
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Gao L, Pan X, Zhang JH, Xia Y. Glial cells: an important switch for the vascular function of the central nervous system. Front Cell Neurosci 2023; 17:1166770. [PMID: 37206667 PMCID: PMC10188976 DOI: 10.3389/fncel.2023.1166770] [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: 02/15/2023] [Accepted: 04/13/2023] [Indexed: 05/21/2023] Open
Abstract
In this review, we first describe the current understanding of glial-mediated vascular function affecting the role of the blood-brain barrier (BBB) in central nervous system (CNS) disorders. BBB, mainly composed of glial and endothelial cells (ECs), is the protective structure that orchestrates the transport of substances, including ions, molecules, and cells from brain vessels into or out of the CNS. Then, we display the multiple communication between glial and vascular function based on angiogenesis, vascular wrapping, and blood perfusion in the brain. Glial can support microvascular ECs to form a blood network connecting to neurons. Astrocytes, microglia, and oligodendrocytes are the common types of glial surrounding the brain vessel. Glial-vessel interaction is required for the permeability and integrity of BBB. Glial cells surrounding the cerebral blood vessels can transmit communication signals to ECs and regulate the activity of vascular endothelial growth factor (VEGF) or Wnt-dependent endothelial angiogenesis mechanism. In addition, these glial cells monitor the blood flow in the brain via Ca2+/K+-dependent pathways. Finally, we provide a potential research direction for the glial-vessel axis in CNS disorders. Microglial activation can trigger astrocyte activation, which suggests that microglia-astrocyte interaction may play a key role in monitoring cerebral blood flow. Thus, microglia-astrocyte interaction can be the key point of follow-up studies focusing on the microglia-blood mechanism. More investigations focus on the mechanism of how oligodendrocyte progenitor cells communicate and interact with ECs. The direct role of oligodendrocytes in modulating vascular function needs to be explored in the future.
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Affiliation(s)
- Ling Gao
- Department of Neurosurgery, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou, China
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Xuezhen Pan
- Department of Neurosurgery, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou, China
| | - John H. Zhang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
- John H. Zhang,
| | - Ying Xia
- Department of Neurosurgery, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou, China
- *Correspondence: Ying Xia,
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8
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Engelbrecht E, Kooistra T, Knipe RS. The Vasculature in Pulmonary Fibrosis. CURRENT TISSUE MICROENVIRONMENT REPORTS 2022; 3:83-97. [PMID: 36712832 PMCID: PMC9881604 DOI: 10.1007/s43152-022-00040-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/23/2022] [Indexed: 02/02/2023]
Abstract
Purpose of Review The current paradigm of idiopathic pulmonary fibrosis (IPF) pathogenesis involves recurrent injury to a sensitive alveolar epithelium followed by impaired repair responses marked by fibroblast activation and deposition of extracellular matrix. Multiple cell types are involved in this response with potential roles suggested by advances in single-cell RNA sequencing and lung developmental biology. Notably, recent work has better characterized the cell types present in the pulmonary endothelium and identified vascular changes in patients with IPF. Recent Findings Lung tissue from patients with IPF has been examined at single-cell resolution, revealing reductions in lung capillary cells and expansion of a population of vascular cells expressing markers associated with bronchial endothelium. In addition, pre-clinical models have demonstrated a fundamental role for aging and vascular permeability in the development of pulmonary fibrosis. Summary Mounting evidence suggests that the endothelium undergoes changes in the context of fibrosis, and these changes may contribute to the development and/or progression of pulmonary fibrosis. Additional studies will be needed to further define the functional role of these vascular changes.
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Affiliation(s)
| | - Tristan Kooistra
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Rachel S. Knipe
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
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Characterization of Astrocytes in the Minocycline-Administered Mouse Photothrombotic Ischemic Stroke Model. Neurochem Res 2022; 47:2839-2855. [PMID: 35907114 DOI: 10.1007/s11064-022-03703-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/10/2022] [Accepted: 07/16/2022] [Indexed: 10/16/2022]
Abstract
Astrocytes, together with microglia, play important roles in the non-infectious inflammation and scar formation at the brain infarct during ischemic stroke. After ischemia occurs, these become highly reactive, accumulate at the infarction, and release various inflammatory signaling molecules. The regulation of astrocyte reactivity and function surrounding the infarction largely depends on intercellular communication with microglia. However, the mechanisms involved remain unclear. Furthermore, recent molecular biological studies have revealed that astrocytes are highly divergent under both resting and reactive states, whereas it has not been well reported how the communication between microglia and astrocytes affects astrocyte divergency during ischemic stroke. Minocycline, an antibiotic that reduces microglial activity, has been used to examine the functional roles of microglia in mice. In this study, we used a mouse photothrombotic ischemic stroke model to examine the characteristics of astrocytes after the administration of minocycline during ischemic stroke. Minocycline increased astrocyte reactivity and affected the localization of astrocytes in the penumbra region. Molecular characterization revealed that the induced expression of mRNA encoding the fatty acid binding protein 7 (FABP7) by photothrombosis was enhanced by the minocycline administration. Meanwhile, minocycline did not significantly affect the phenotype or class of astrocytes. The expression of Fabp7 mRNA was well correlated with that of tumor-necrosis factor α (TNFα)-encoding Tnf mRNA, indicating that a correlated expression of FABP7 from astrocytes and TNFα is suppressed by microglial activity.
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10
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Jiang Y, Duan LJ, Fong GH. Oxygen-sensing mechanisms in development and tissue repair. Development 2021; 148:273632. [PMID: 34874450 DOI: 10.1242/dev.200030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Under normoxia, hypoxia inducible factor (HIF) α subunits are hydroxylated by PHDs (prolyl hydroxylase domain proteins) and subsequently undergo polyubiquitylation and degradation. Normal embryogenesis occurs under hypoxia, which suppresses PHD activities and allows HIFα to stabilize and regulate development. In this Primer, we explain molecular mechanisms of the oxygen-sensing pathway, summarize HIF-regulated downstream events, discuss loss-of-function phenotypes primarily in mouse development, and highlight clinical relevance to angiogenesis and tissue repair.
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Affiliation(s)
- Yida Jiang
- Center for Vascular Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Li-Juan Duan
- Center for Vascular Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Guo-Hua Fong
- Center for Vascular Biology, University of Connecticut Health Center, Farmington, CT 06030, USA.,Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
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Li G, Liu J, Guan Y, Ji X. The role of hypoxia in stem cell regulation of the central nervous system: From embryonic development to adult proliferation. CNS Neurosci Ther 2021; 27:1446-1457. [PMID: 34817133 PMCID: PMC8611781 DOI: 10.1111/cns.13754] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/28/2021] [Accepted: 10/03/2021] [Indexed: 12/12/2022] Open
Abstract
Hypoxia is involved in the regulation of various cell functions in the body, including the regulation of stem cells. The hypoxic microenvironment is indispensable from embryonic development to the regeneration and repair of adult cells. In addition to embryonic stem cells, which need to maintain their self-renewal properties and pluripotency in a hypoxic environment, adult stem cells, including neural stem cells (NSCs), also exist in a hypoxic microenvironment. The subventricular zone (SVZ) and hippocampal dentate gyrus (DG) are the main sites of adult neurogenesis in the brain. Hypoxia can promote the proliferation, migration, and maturation of NSCs in these regions. Also, because most neurons in the brain are non-regenerative, stem cell transplantation is considered as a promising strategy for treating central nervous system (CNS) diseases. Hypoxic treatment also increases the effectiveness of stem cell therapy. In this review, we firstly describe the role of hypoxia in different stem cells, such as embryonic stem cells, NSCs, and induced pluripotent stem cells, and discuss the role of hypoxia-treated stem cells in CNS diseases treatment. Furthermore, we highlight the role and mechanisms of hypoxia in regulating adult neurogenesis in the SVZ and DG and adult proliferation of other cells in the CNS.
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Affiliation(s)
- Gaifen Li
- Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Institute of Brain DisordersCapital Medical UniversityBeijingChina
- Department of NeurosurgeryXuanwu HospitalCapital Medical UniversityBeijingChina
| | - Jia Liu
- Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Institute of Brain DisordersCapital Medical UniversityBeijingChina
| | - Yuying Guan
- Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Institute of Brain DisordersCapital Medical UniversityBeijingChina
- Department of NeurosurgeryXuanwu HospitalCapital Medical UniversityBeijingChina
| | - Xunming Ji
- Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Institute of Brain DisordersCapital Medical UniversityBeijingChina
- Department of NeurosurgeryXuanwu HospitalCapital Medical UniversityBeijingChina
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12
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Paisley CE, Kay JN. Seeing stars: Development and function of retinal astrocytes. Dev Biol 2021; 478:144-154. [PMID: 34260962 DOI: 10.1016/j.ydbio.2021.07.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 02/06/2023]
Abstract
Throughout the central nervous system, astrocytes adopt precisely ordered spatial arrangements of their somata and arbors, which facilitate their many important functions. Astrocyte pattern formation is particularly important in the retina, where astrocytes serve as a template that dictates the pattern of developing retinal vasculature. Thus, if astrocyte patterning is disturbed, there are severe consequences for retinal angiogenesis and ultimately for vision - as seen in diseases such as retinopathy of prematurity. Here we discuss key steps in development of the retinal astrocyte population. We describe how fundamental developmental forces - their birth, migration, proliferation, and death - sculpt astrocytes into a template that guides angiogenesis. We further address the radical changes in the cellular and molecular composition of the astrocyte network that occur upon completion of angiogenesis, paving the way for their adult functions in support of retinal ganglion cell axons. Understanding development of retinal astrocytes may elucidate pattern formation mechanisms that are deployed broadly by other axon-associated astrocyte populations.
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Affiliation(s)
- Caitlin E Paisley
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Jeremy N Kay
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC, 27710, USA.
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