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  1. Article ; Online: A guanidine-rich regulatory oligodeoxynucleotide improves type-2 diabetes in obese mice by blocking T-cell differentiation.

    Cheng, Xiang / Wang, Jing / Xia, Ni / Yan, Xin-Xin / Tang, Ting-Ting / Chen, Han / Zhang, Hong-Jian / Liu, Juan / Kong, Wen / Sjöberg, Sara / Folco, Eduardo / Libby, Peter / Liao, Yu-Hua / Shi, Guo-Ping

    EMBO molecular medicine

    2012  Volume 4, Issue 10, Page(s) 1112–1125

    Abstract: T lymphocytes exhibit pro-inflammatory or anti-inflammatory activities in obesity and diabetes ... without affecting Th2 and regulatory T cells. ODNR01 improves glucose tolerance and insulin sensitivity in both diet ... and insulin sensitivity in CD4(+) T-cell-reconstituted Rag1-deficient DIO mice, suggesting ...

    Abstract T lymphocytes exhibit pro-inflammatory or anti-inflammatory activities in obesity and diabetes, depending on their subtypes. Guanidine-rich immunosuppressive oligodeoxynucleotides (ODNs) effectively control Th1/Th2-cell counterbalance. This study reveals a non-toxic regulatory ODN (ODNR01) that inhibits Th1- and Th17-cell polarization by binding to STAT1/3/4 and blocking their phosphorylation without affecting Th2 and regulatory T cells. ODNR01 improves glucose tolerance and insulin sensitivity in both diet-induced obese (DIO) and genetically generated obese (ob/ob) mice. Mechanistic studies show that ODNR01 suppresses Th1- and Th17-cell differentiation in white adipose tissue, thereby reducing macrophage accumulation and M1 macrophage inflammatory molecule expression without affecting M2 macrophages. While ODNR01 shows no effect on diabetes in lymphocyte-free Rag1-deficient DIO mice, it enhances glucose tolerance and insulin sensitivity in CD4(+) T-cell-reconstituted Rag1-deficient DIO mice, suggesting its beneficial effect on insulin resistance is T-cell-dependent. Therefore, regulatory ODNR01 reduces obesity-associated insulin resistance through modulation of T-cell differentiation.
    MeSH term(s) Animals ; Cell Differentiation/drug effects ; Diabetes Mellitus, Type 2/drug therapy ; Disease Models, Animal ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Obese ; Oligodeoxyribonucleotides/administration & dosage ; Phosphorylation/drug effects ; STAT1 Transcription Factor/antagonists & inhibitors ; STAT3 Transcription Factor/antagonists & inhibitors ; STAT4 Transcription Factor/antagonists & inhibitors ; Th1 Cells/drug effects ; Th17 Cells/drug effects ; Treatment Outcome
    Chemical Substances Oligodeoxyribonucleotides ; STAT1 Transcription Factor ; STAT3 Transcription Factor ; STAT4 Transcription Factor ; Stat1 protein, mouse ; Stat3 protein, mouse ; Stat4 protein, mouse
    Language English
    Publishing date 2012-09-30
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2467145-9
    ISSN 1757-4684 ; 1757-4676
    ISSN (online) 1757-4684
    ISSN 1757-4676
    DOI 10.1002/emmm.201201272
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Vascular derived endothelin receptor A controls endothelin-induced retinal ganglion cell death.

    Marola, Olivia J / Howell, Gareth R / Libby, Richard T

    Cell death discovery

    2022  Volume 8, Issue 1, Page(s) 207

    Abstract: Endothelin (EDN, also known as ET) signaling has been suggested to be an important mediator of retinal ganglion cell (RGC) death in glaucoma. Antagonism of EDN receptors (EDNRA and EDNRB, also known as ET-A and ET-B) prevented RGC death in mouse models ... ...

    Abstract Endothelin (EDN, also known as ET) signaling has been suggested to be an important mediator of retinal ganglion cell (RGC) death in glaucoma. Antagonism of EDN receptors (EDNRA and EDNRB, also known as ET-A and ET-B) prevented RGC death in mouse models of chronic ocular hypertension, and intravitreal injection of EDN ligand was sufficient to drive RGC death. However, it remains unclear which cell types EDN ligands directly affect to elicit RGC death. Multiple cell types in the retina and optic nerve express EDNRA and EDNRB and thus could respond to EDN ligands in the context of glaucoma. Here, we systematically deleted Edn receptors from specific cell types to identify the critical EDN receptor mediating RGC death in vivo. Deletion of both Ednra and Ednrb from retinal neurons (including RGCs) and macroglia did not prevent RGC loss after exposure to EDN1 ligands, suggesting EDN1 ligands cause RGC death via an indirect mechanism involving a secondary cell type. Deletion of Ednra from the full body, and then specifically from vascular mural cells, prevented EDN1-induced vasoconstriction and RGC death. Together, these data suggest EDN ligands cause RGC death via a mechanism initiated by vascular mural cells. It is possible RGC death is a consequence of vascular mural cell-induced vasoconstriction and its pathological sequelae. These results highlight the potential importance of neurovascular dysfunction in glaucoma.
    Language English
    Publishing date 2022-04-16
    Publishing country United States
    Document type Journal Article
    ISSN 2058-7716
    ISSN 2058-7716
    DOI 10.1038/s41420-022-00985-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Microglia Depletion leads to Increased Susceptibility to Ocular Hypertension-Dependent Glaucoma.

    Diemler, Cory A / MacLean, Michael / Heuer, Sarah E / Hewes, Amanda A / Marola, Olivia J / Libby, Richard T / Howell, Gareth R

    bioRxiv : the preprint server for biology

    2024  

    Abstract: In recent years, microglia have been highlighted for playing integral roles in neurodegenerative diseases, like glaucoma. To better understand the role of microglia during chronic ocular hypertension, we depleted microglia from aged (9-12 months old) DBA/ ...

    Abstract In recent years, microglia have been highlighted for playing integral roles in neurodegenerative diseases, like glaucoma. To better understand the role of microglia during chronic ocular hypertension, we depleted microglia from aged (9-12 months old) DBA/2J (D2) mice, which exhibit age-related increases in intraocular pressure, using a dietary CSF1R antagonist, PLX5622. Retinal ganglion cell (RGC) somas were counted, and optic nerve cross-sections stained and assessed for glaucomatous damage. Sustained administration of dietary PLX5622 significantly reduced the numbers of retinal microglia. Dietary PLX5622 did not lead to changes in intraocular pressure in D2 or normotensive DBA/2J-
    Language English
    Publishing date 2024-03-10
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2024.03.05.583529
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: BclX

    Marola, Olivia J / Yablonski, Sarah E R / Shrager, Peter G / Nickells, Robert W / Libby, Richard T

    Cell death discovery

    2022  Volume 8, Issue 1, Page(s) 331

    Language English
    Publishing date 2022-07-22
    Publishing country United States
    Document type Journal Article
    ISSN 2058-7716
    ISSN 2058-7716
    DOI 10.1038/s41420-022-01111-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Transcriptional control of retinal ganglion cell death after axonal injury.

    Syc-Mazurek, Stephanie B / Yang, Hongtian Stanley / Marola, Olivia J / Howell, Gareth R / Libby, Richard T

    Cell death & disease

    2022  Volume 13, Issue 3, Page(s) 244

    Abstract: Injury to the axons of retinal ganglion cells (RGCs) is a key pathological event in glaucomatous neurodegeneration. The transcription factors JUN (the target of the c-Jun N-terminal kinases, JNKs) and DDIT3/CHOP (a mediator of the endoplasmic reticulum ... ...

    Abstract Injury to the axons of retinal ganglion cells (RGCs) is a key pathological event in glaucomatous neurodegeneration. The transcription factors JUN (the target of the c-Jun N-terminal kinases, JNKs) and DDIT3/CHOP (a mediator of the endoplasmic reticulum stress response) have been shown to control the majority of proapoptotic signaling after mechanical axonal injury in RGCs and in other models of neurodegeneration. The downstream transcriptional networks controlled by JUN and DDIT3, which are critical for RGC death, however, are not well defined. To determine these networks, RNA was isolated from the retinas of wild-type mice and mice deficient in Jun, Ddit3, and both Jun and Ddit3 three days after mechanical optic nerve crush injury (CONC). RNA-sequencing data analysis was performed and immunohistochemistry was used to validate potential transcriptional signaling changes after axonal injury. This study identified downstream transcriptional changes after injury including both neuronal survival and proinflammatory signaling that were attenuated to differing degrees by loss of Ddit3, Jun, and Ddit3/Jun. These data suggest proinflammatory signaling in the retina might be secondary to activation of pro-death pathways in RGCs after acute axonal injury. These results determine the downstream transcriptional networks important for apoptotic signaling which may be important for ordering and staging the pro-degenerative signals after mechanical axonal injury.
    MeSH term(s) Animals ; Axons/metabolism ; Disease Models, Animal ; Mice ; Mice, Inbred C57BL ; Optic Nerve Injuries/metabolism ; RNA/metabolism ; Retinal Ganglion Cells/metabolism
    Chemical Substances RNA (63231-63-0)
    Language English
    Publishing date 2022-03-16
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2541626-1
    ISSN 2041-4889 ; 2041-4889
    ISSN (online) 2041-4889
    ISSN 2041-4889
    DOI 10.1038/s41419-022-04666-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: BAX activation in mouse retinal ganglion cells occurs in two temporally and mechanistically distinct steps.

    Maes, Margaret E / Donahue, Ryan J / Schlamp, Cassandra L / Marola, Olivia J / Libby, Richard T / Nickells, Robert

    Research square

    2023  

    Abstract: Background Pro-apoptotic BAX is a central mediator of retinal ganglion cell (RGC) death after optic nerve damage. BAX activation occurs in two stages including translocation of latent BAX to the mitochondrial outer membrane (MOM) and then ... ...

    Abstract Background Pro-apoptotic BAX is a central mediator of retinal ganglion cell (RGC) death after optic nerve damage. BAX activation occurs in two stages including translocation of latent BAX to the mitochondrial outer membrane (MOM) and then permeabilization of the MOM to facilitate the release of apoptotic signaling molecules. As a critical component of RGC death, BAX is an attractive target for neuroprotective therapies and an understanding of the kinetics of BAX activation and the mechanisms controlling the two stages of this process in RGCs is potentially valuable in informing the development of a neuroprotective strategy. Methods The kinetics of BAX translocation were assessed by both static and live-cell imaging of a GFP-BAX fusion protein introduced into RGCs using AAV2-mediated gene transfer in mice. Activation of BAX was achieved using an acute optic nerve crush (ONC) protocol. Live-cell imaging of GFP-BAX was achieved using explants of mouse retina harvested 7 days after ONC. Kinetics of translocation in RGCs were compared to GFP-BAX translocation in 661W tissue culture cells. Permeabilization of GFP-BAX was assessed by staining with the 6A7 monoclonal antibody, which recognizes a conformational change in this protein after MOM insertion. Assessment of individual kinases associated with both stages of activation was made using small molecule inhibitors injected into the vitreous either independently or in concert with ONC surgery. The contribution of the Dual Leucine Zipper-JUN-N-Terminal Kinase cascade was evaluated using mice with a double conditional knock-out of both
    Language English
    Publishing date 2023-05-15
    Publishing country United States
    Document type Preprint
    DOI 10.21203/rs.3.rs-2846437/v1
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: BAX activation in mouse retinal ganglion cells occurs in two temporally and mechanistically distinct steps.

    Maes, Margaret E / Donahue, Ryan J / Schlamp, Cassandra L / Marola, Olivia J / Libby, Richard T / Nickells, Robert W

    Molecular neurodegeneration

    2023  Volume 18, Issue 1, Page(s) 67

    Abstract: Background: Pro-apoptotic BAX is a central mediator of retinal ganglion cell (RGC) death after optic nerve damage. BAX activation occurs in two stages including translocation of latent BAX to the mitochondrial outer membrane (MOM) and then ... ...

    Abstract Background: Pro-apoptotic BAX is a central mediator of retinal ganglion cell (RGC) death after optic nerve damage. BAX activation occurs in two stages including translocation of latent BAX to the mitochondrial outer membrane (MOM) and then permeabilization of the MOM to facilitate the release of apoptotic signaling molecules. As a critical component of RGC death, BAX is an attractive target for neuroprotective therapies and an understanding of the kinetics of BAX activation and the mechanisms controlling the two stages of this process in RGCs is potentially valuable in informing the development of a neuroprotective strategy.
    Methods: The kinetics of BAX translocation were assessed by both static and live-cell imaging of a GFP-BAX fusion protein introduced into RGCs using AAV2-mediated gene transfer in mice. Activation of BAX was achieved using an acute optic nerve crush (ONC) protocol. Live-cell imaging of GFP-BAX was achieved using explants of mouse retina harvested 7 days after ONC. Kinetics of translocation in RGCs were compared to GFP-BAX translocation in 661W tissue culture cells. Permeabilization of GFP-BAX was assessed by staining with the 6A7 monoclonal antibody, which recognizes a conformational change in this protein after MOM insertion. Assessment of individual kinases associated with both stages of activation was made using small molecule inhibitors injected into the vitreous either independently or in concert with ONC surgery. The contribution of the Dual Leucine Zipper-JUN-N-Terminal Kinase cascade was evaluated using mice with a double conditional knock-out of both Mkk4 and Mkk7.
    Results: ONC induces the translocation of GFP-BAX in RGCs at a slower rate and with less intracellular synchronicity than 661W cells, but exhibits less variability among mitochondrial foci within a single cell. GFP-BAX was also found to translocate in all compartments of an RGC including the dendritic arbor and axon. Approximately 6% of translocating RGCs exhibited retrotranslocation of BAX immediately following translocation. Unlike tissue culture cells, which exhibit simultaneous translocation and permeabilization, RGCs exhibited a significant delay between these two stages, similar to detached cells undergoing anoikis. Translocation, with minimal permeabilization could be induced in a subset of RGCs using an inhibitor of Focal Adhesion Kinase (PF573228). Permeabilization after ONC, in a majority of RGCs, could be inhibited with a broad spectrum kinase inhibitor (sunitinib) or a selective inhibitor for p38/MAPK14 (SB203580). Intervention of DLK-JNK axis signaling abrogated GFP-BAX translocation after ONC.
    Conclusions: A comparison between BAX activation kinetics in tissue culture cells and in cells of a complex tissue environment shows distinct differences indicating that caution should be used when translating findings from one condition to the other. RGCs exhibit both a delay between translocation and permeabilization and the ability for translocated BAX to be retrotranslocated, suggesting several stages at which intervention of the activation process could be exploited in the design of a therapeutic strategy.
    MeSH term(s) Animals ; Mice ; Retinal Ganglion Cells ; bcl-2-Associated X Protein ; Optic Nerve ; Antibodies, Monoclonal ; Apoptosis
    Chemical Substances bcl-2-Associated X Protein ; Antibodies, Monoclonal
    Language English
    Publishing date 2023-09-26
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2244557-2
    ISSN 1750-1326 ; 1750-1326
    ISSN (online) 1750-1326
    ISSN 1750-1326
    DOI 10.1186/s13024-023-00659-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Axon injury signaling and compartmentalized injury response in glaucoma.

    Syc-Mazurek, Stephanie B / Libby, Richard T

    Progress in retinal and eye research

    2019  Volume 73, Page(s) 100769

    Abstract: Axonal degeneration is an active, highly controlled process that contributes to beneficial processes, such as developmental pruning, but also to neurodegeneration. In glaucoma, ocular hypertension leads to vision loss by killing the output neurons of the ...

    Abstract Axonal degeneration is an active, highly controlled process that contributes to beneficial processes, such as developmental pruning, but also to neurodegeneration. In glaucoma, ocular hypertension leads to vision loss by killing the output neurons of the retina, the retinal ganglion cells (RGCs). Multiple processes have been proposed to contribute to and/or mediate axonal injury in glaucoma, including: neuroinflammation, loss of neurotrophic factors, dysregulation of the neurovascular unit, and disruption of the axonal cytoskeleton. While the inciting injury to RGCs in glaucoma is complex and potentially heterogeneous, axonal injury is ultimately thought to be the key insult that drives glaucomatous neurodegeneration. Glaucomatous neurodegeneration is a complex process, with multiple molecular signals contributing to RGC somal loss and axonal degeneration. Furthermore, the propagation of the axonal injury signal is complex, with injury triggering programs of degeneration in both the somal and axonal compartment. Further complicating this process is the involvement of multiple cell types that are known to participate in the process of axonal and neuronal degeneration after glaucomatous injury. Here, we review the axonal signaling that occurs after injury and the molecular signaling programs currently known to be important for somal and axonal degeneration after glaucoma-relevant axonal injuries.
    MeSH term(s) Animals ; Axons/physiology ; Glaucoma/physiopathology ; Humans ; Intraocular Pressure ; Optic Nerve Injuries/physiopathology ; Retinal Ganglion Cells/physiology ; Signal Transduction/physiology
    Language English
    Publishing date 2019-07-10
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 1182683-6
    ISSN 1873-1635 ; 1350-9462
    ISSN (online) 1873-1635
    ISSN 1350-9462
    DOI 10.1016/j.preteyeres.2019.07.002
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Age- and glaucoma-induced changes to the ocular glymphatic system.

    Wang, Xiaowei / Delle, Christine / Peng, Weiguo / Plá, Virginia / Giannetto, Michael / Kusk, Peter / Sigurdsson, Björn / Sakurai, Shinya / Sweeney, Amanda / Sun, Qian / Du, Ting / Libby, Richard T / Nedergaard, Maiken

    Neurobiology of disease

    2023  Volume 188, Page(s) 106322

    Abstract: The ocular glymphatic system supports bidirectional fluid transport along the optic nerve, thereby removes metabolic wastes including amyloid-β. To better understand this biological process, we examined the distributions of intravitreally and ... ...

    Abstract The ocular glymphatic system supports bidirectional fluid transport along the optic nerve, thereby removes metabolic wastes including amyloid-β. To better understand this biological process, we examined the distributions of intravitreally and intracisternally infused tracers in full-length optic nerves from different age groups of mice. Aging was linked to globally impaired ocular glymphatic fluid transport, similar to what has seen previously in the brain. Aging also reduced the pupillary responsiveness to light stimulation and abolished light-induced facilitation in anterograde ocular glymphatic flow. In contrast to normal aging, in the DBA/2 J model of glaucoma, we found a pathological increase of glymphatic fluid transport to the anterior optic nerve that was associated with dilation of the perivascular spaces. Thus, aging and glaucoma have fundamentally different effects on ocular glymphatic fluid transport. Manipulation of glymphatic fluid transport might therefore present a new target for the treatment of glaucoma.
    MeSH term(s) Animals ; Mice ; Mice, Inbred DBA ; Glymphatic System ; Glaucoma ; Face ; Aging
    Language English
    Publishing date 2023-10-12
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1211786-9
    ISSN 1095-953X ; 0969-9961
    ISSN (online) 1095-953X
    ISSN 0969-9961
    DOI 10.1016/j.nbd.2023.106322
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: TNF-α and NF-κB signaling play a critical role in cigarette smoke-induced epithelial-mesenchymal transition of retinal pigment epithelial cells in proliferative vitreoretinopathy.

    Wang, Victor / Heffer, Alison / Roztocil, Elisa / Feldon, Steven E / Libby, Richard T / Woeller, Collynn F / Kuriyan, Ajay E

    PloS one

    2022  Volume 17, Issue 9, Page(s) e0271950

    Abstract: Proliferative vitreoretinopathy (PVR) is characterized by the growth and contraction of cellular membranes within the vitreous cavity and on both surfaces of the retina, resulting in recurrent retinal detachments and poor visual outcomes. Proinflammatory ...

    Abstract Proliferative vitreoretinopathy (PVR) is characterized by the growth and contraction of cellular membranes within the vitreous cavity and on both surfaces of the retina, resulting in recurrent retinal detachments and poor visual outcomes. Proinflammatory cytokines like tumor necrosis factor alpha (TNFα) have been associated with PVR and the epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells. Cigarette smoke is the only known modifiable risk factor for PVR, but the mechanisms are unclear. The purpose of this study was to examine the impact of cigarette smoke on the proinflammatory TNFα/NF-κB/Snail pathway in RPE cells to better understand the mechanisms through which cigarette smoke increases the risk of PVR. Human ARPE-19 cells were exposed to cigarette smoke extract (CSE), for 4 to 24-hours and TNFα, Snail, IL-6, IL-8, and α-SMA levels were analyzed by qPCR and/or Western blot. The severity of PVR formation was assessed in a murine model of PVR after intravitreal injection of ARPE-19 cells pre-treated with CSE or not. Fundus imaging, OCT imaging, and histologic analysis 4 weeks after injection were used to examine PVR severity. ARPE-19 cells exposed to CSE expressed higher levels of TNFα, SNAIL, IL6 and IL8 mRNA as well as SNAIL, Vimentin and α-SMA protein. Inhibition of TNFα and NF-κB pathways blocked the effect of CSE. In vivo, intravitreal injection of ARPE-19 cells treated with CSE resulted in more severe PVR compared to mice injected with untreated RPE cells. These studies suggest that the TNFα pathway is involved in the mechanism whereby cigarette smoke increases PVR. Further investigation into the role of TNFα/NF-κB/Snail in driving PVR and pharmacological targeting of these pathways in disease are warranted.
    MeSH term(s) Animals ; Cigarette Smoking/adverse effects ; Epithelial Cells/metabolism ; Epithelial-Mesenchymal Transition ; Humans ; Mice ; NF-kappa B/metabolism ; Retinal Pigment Epithelium/metabolism ; Nicotiana/adverse effects ; Tumor Necrosis Factor-alpha/metabolism ; Vitreoretinopathy, Proliferative/metabolism
    Chemical Substances NF-kappa B ; Tumor Necrosis Factor-alpha
    Language English
    Publishing date 2022-09-01
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2267670-3
    ISSN 1932-6203 ; 1932-6203
    ISSN (online) 1932-6203
    ISSN 1932-6203
    DOI 10.1371/journal.pone.0271950
    Database MEDical Literature Analysis and Retrieval System OnLINE

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