Syngeneic central nervous system transplantation of genetically transduced mature, adult astrocytes

Selkirk, SM; Greenberg, SJ; Plunkett, RJ; Barone, TA; Lis, Agnieszka; Spence, PO

doi:10.1038/sj.gt.3301643

Cited by 28 publications

(18 citation statements)

References 29 publications

(34 reference statements)

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“…In accordance with a previous report (Selkirk et al, 2002), the ability of transplanted astrocytes to migrate was limited, but with increasing time the transplanted cells were attracted by Ab deposits. Hippocampal Ab burden was decreased by about 70% in the vicinity of transplanted astrocytes in 12-month-old APdE9 mice and much less, by about 40%, when astrocytes were transplanted into very old APdE9 mice.…”

Section: Discussionsupporting

confidence: 90%

Multiple cellular and molecular mechanisms Are involved in human Aβ clearance by transplanted adult astrocytes

Pihlaja

Koistinaho

Kauppinen

et al. 2011

Glia

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Astrocytes and microglia are able to degrade potentially neurotoxic β-amyloid (Aβ) deposits typical for Alzheimer's disease (AD) pathology. Contrary to microglia, astrocytes degrade human Aβ from tissue sections in vitro without any additional stimulation, but it has remained unclear whether transplanted astrocytes are able to clear deposited human Aβ in vivo. We transplanted adult mouse astrocytes into the hippocampi of transgenic mice mimicking AD and observed their fate, effects on microglial responses, and Aβ clearance. After 2-months follow-up time, we discovered a significant reduction in Aβ burden compared with AD mice infused with PBS only. The remaining Aβ deposits were fragmented and most of the Aβ immunoreactivity was seen within the transplanted astrocytes. Concomitant to Aβ reduction, both CD68 and CD45 immunoreactivities were significantly upregulated but phagocytic microglia were often surrounding and engulfing Aβ burdened, TUNEL-positive astrocytes rather than co-localizing with Aβ alone. Astrocytes are known to degrade Aβ also by secreting proteases involved in Aβ catabolism. To study the contribution of neprilysin (NEP), angiotensin-converting enzyme-1 (ACE-1), and endothelin-converting enzyme-2 (ECE-2) in human Aβ clearance, we utilized an ex vivo assay to demonstrate that adult astrocytes respond to human Aβ by upregulating NEP expression. Further, incubation of adult astrocytes with known inhibitors of NEP, ACE-1, or ECE-2 significantly inhibited the removal of human Aβ from the tissue suggesting an important role for these proteases in Aβ clearance by adult astrocytes ex vivo.

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Section: Discussionsupporting

confidence: 90%

Multiple cellular and molecular mechanisms Are involved in human Aβ clearance by transplanted adult astrocytes

Pihlaja

Koistinaho

Kauppinen

et al. 2011

Glia

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“…GFP-encoding amphotropic retrovirus producing cells (kindly provided by Dr. Steven J. Greenberg, Roswell Park Cancer Institute, Buffalo, NY) 33 were produced by transfection of murine fibroblast derived PA317 packaging cells with the LXCGN retroviral vector. 34,35 Retrovirus was harvested from producer cells as described previously.…”

Section: Fibroblast Migration On Collagen Threadsmentioning

confidence: 99%

Crosslinking of discrete self‐assembled collagen threads: Effects on mechanical strength and cell–matrix interactions

Cornwell

Lei

Andreadis

et al. 2006

J Biomedical Materials Res

135

111

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Bundles of threads extruded from type I collagen have been researched extensively as scaffolds to promote the repair and regeneration of torn tendons and ligaments. The success of these scaffolds has been limited by insufficient tissue ingrowth from the wound margin, which may be inhibited by the chemical or physical crosslinking treatment used to increase the mechanical properties and decrease the degradation rate of these scaffolds. Recently, self-assembled collagen threads extruded from solutions of type I collagen molecules were shown to possess ultimate tensile strengths and structural properties comparable to native tendon fibers; however the tissue response to these threads has yet to be determined. The goal of this study was to investigate the effects of various crosslinking techniques on the mechanical properties as well as the in vitro rate of new tissue ingrowth on these threads. Our findings indicate that the physical crosslinking techniques, dehydrothermal (DHT) or ultraviolet light (UV), most significantly improve the mechanical strengths of the threads, but most significantly decrease the rate of cell migration. In contrast, carbodiimide (EDC) crosslinking achieved sub-optimal strength generation, but demonstrated improved cell migration rates. Future studies will investigate the design of threads with surface biochemistries that maximize tissue ingrowth while maintaining the mechanical stability of the scaffold.

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“…LXCGN encodes an enhanced green fluorescence protein (GFP)-neomycin phosphotransferase fusion protein (EGFP-Neo r ) transcriptionally controlled by the cytomegalovirus-derived promoter. GFP-encoding amphotropic retrovirus-producing cells (kindly provided by Steven J. Greenberg, Roswell Park Cancer Institute) (35) were produced by transfection of PA317 packaging cells (25) with the LXCGN retroviral vector. The BAG retroviral vector encodes ␤-galactosidase under the control of the viral long terminal repeat (32).…”

Section: Retroviral Vectors and Packaging Cellsmentioning

confidence: 99%

Retrovirus-Associated Heparan Sulfate Mediates Immobilization and Gene Transfer on Recombinant Fibronectin

Lei

Bajaj

Andreadis

2002

J Virol

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Recombinant retroviruses have been shown to bind to fibronectin (FN) and increase the efficiency of gene transfer to a variety of cell types. Despite recent work to optimize gene transfer on recombinant FN, the mechanism of retrovirus binding to FN and the interactions of target cells with the bound virus remain elusive. We investigated the roles of virus surface glycoprotein (gp70), cell-conditioned medium, and proteoglycans in mediating retrovirus binding to FN. We also examined the role of Polybrene (PB) in these interactions. We found that gp70 is not involved in retrovirus binding to FN. Immobilization of the virus, however, does not overcome its receptor requirement, and gp70 is still needed for successful gene transfer. Our results clearly show that retrovirus binds FN through virus-associated heparan sulfate (HS) and that binding is necessary for transduction without PB. Two distinct modes of gene transfer occur depending on PB: (i) in the presence of PB, retrovirus interacts directly with the target cells; and (ii) in the absence of PB, retrovirus binds to FN and target cells interact with the immobilized virus. PB may promote the former mode by interacting with the virus HS and reducing the negative charge of the viral particles. Interestingly, the latter mode is more efficient, leading to significantly enhanced gene transfer. A better understanding of these interactions may provide insight into virus-cell interactions and lead to a more rational design of transduction protocols.The ability of retrovirus to bind to fibronectin (FN) has been utilized to transfer genes by colocalization of virus and target cells (17). This method, termed FN-assisted gene transfer (16,17), improved retroviral transduction to T lymphocytes (10, 31) and hematopoietic stem cells (7,9,19,29). Two clinical trials that employed this protocol showed promising initial results (1, 6).Immobilization of recombinant retrovirus yielded significantly increased efficiency of gene transfer compared to transduction with retrovirus in solution (3). The amount of immobilized retrovirus was maximized by long times and low temperatures of incubation that preserve its biological activity. In addition, binding of concentrated virus to FN eliminated the effects of transduction inhibitors and toxic metabolic by-products, enhancing gene transfer by more than 10-fold (3).The substrates most commonly employed to immobilize retrovirus are poly-L-lysine (2, 18) and peptides containing a highaffinity heparin-binding domain (1,6,7,9,10,16,17,19,29,31). Poly-L-lysine binds the negatively charged retrovirus most likely through electrostatic interactions. FN binds retrovirus through a high-affinity heparin-binding domain and target cells via two cell-binding domains. One domain is made up of type III repeats containing the RGD and PHSRN sequences that bind integrins ␣5␤1 and ␣3␤1. The other domain contains the IIICS segment and binds integrin ␣4␤1. Recombinant FN fragments used in transduction protocols contain the heparin-binding domain and one (CH271) or...

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Syngeneic central nervous system transplantation of genetically transduced mature, adult astrocytes

Cited by 28 publications

References 29 publications

Multiple cellular and molecular mechanisms Are involved in human Aβ clearance by transplanted adult astrocytes

Multiple cellular and molecular mechanisms Are involved in human Aβ clearance by transplanted adult astrocytes

Crosslinking of discrete self‐assembled collagen threads: Effects on mechanical strength and cell–matrix interactions

Retrovirus-Associated Heparan Sulfate Mediates Immobilization and Gene Transfer on Recombinant Fibronectin

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