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Hwang CH. Targeted Delivery of Erythropoietin Hybridized with Magnetic Nanocarriers for the Treatment of Central Nervous System Injury: A Literature Review. Int J Nanomedicine 2020; 15:9683-9701. [PMID: 33311979 PMCID: PMC7726550 DOI: 10.2147/ijn.s287456] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 11/21/2020] [Indexed: 12/15/2022] Open
Abstract
Although the incidence of central nervous system injuries has continued to rise, no promising treatments have been elucidated. Erythropoietin plays an important role in neuroprotection and neuroregeneration as well as in erythropoiesis. Moreover, the current worldwide use of erythropoietin in the treatment of hematologic diseases allows for its ready application in patients with central nervous system injuries. However, erythropoietin has a very short therapeutic time window (within 6–8 hours) after injury, and it has both hematopoietic and nonhematopoietic receptors, which exhibit heterogenic and phylogenetic differences. These differences lead to limited amounts of erythropoietin binding to in situ erythropoietin receptors. The lack of high-quality evidence for clinical use and the promising results of in vitro/in vivo models necessitate fast targeted delivery agents such as nanocarriers. Among current nanocarriers, noncovalent polymer-entrapping or polymer-adsorbing erythropoietin obtained by nanospray drying may be the most promising. With the incorporation of magnetic nanocarriers into an erythropoietin polymer, spatiotemporal external magnetic navigation is another area of great interest for targeted delivery within the therapeutic time window. Intravenous administration is the most readily used route. Manufactured erythropoietin nanocarriers should be clearly characterized using bioengineering analyses of the in vivo size distribution and the quality of entrapment or adsorption. Further preclinical trials are required to increase the therapeutic bioavailability (in vivo biological identity alteration, passage through the lung capillaries or the blood brain barrier, and timely degradation followed by removal of the nanocarriers from the body) and decrease the adverse effects (hematological complications, neurotoxicity, and cytotoxicity), especially of the nanocarrier.
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Affiliation(s)
- Chang Ho Hwang
- Department of Physical and Rehabilitation Medicine, Chungnam National University Sejong Hospital, Chungnam National University College of Medicine, Sejong, Republic of Korea
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Beltrão-Braga PCB, Koh IHJ, Silva MRR, Gutierrez PS, Han SW. Vascular Adventitia is a Suitable Compartment to Transplant Transduced Vascular Smooth Muscle Cells for Ex Vivo Gene Expression. Cell Transplant 2017. [DOI: 10.3727/000000002783985486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Vascular smooth muscle cells (VSMC) are ideal for systemic gene therapy because of their proximity to blood vessels and they have demonstrated long-term exogenous gene expression in vivo. However, the procedure generally followed to seed the transduced VSMC onto arteries denuded of endothelial cells usually induces stenosis and thrombosis, with a consequent high risk for use in humans. We demonstrate here that the vascular adventitia is a suitable place to introduce transduced VSMC and to secrete therapeutic proteins into the blood stream by a simple procedure, avoiding postoperative vascular complications. Transduced VSMC, with the retroviral vectors carrying the human growth hormone gene (hGH), were seeded into the adventitia of the rat abdominal aorta by single injection of a cell suspension. Based on the hGH and anti-hGH production in serum and on histological analysis of the removed aortas, we demonstrated hGH production over the 2-month experimental period. None of the animals used in the experiment showed stenosis, thrombosis, or other vascular or visible physiological abnormalities.
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Affiliation(s)
| | - Ivan H. J. Koh
- Department of Pediatrics, UNIFESP-EPM, São Paulo, 04023-062, Brazil
| | | | | | - Sang W. Han
- Department of Biophysics, UNIFESP-EPM, São Paulo, 04023-062, Brazil
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Induction of erythropoiesis using human vascular networks genetically engineered for controlled erythropoietin release. Blood 2011; 118:5420-8. [PMID: 21937702 DOI: 10.1182/blood-2011-08-372946] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
For decades, autologous ex vivo gene therapy has been postulated as a potential alternative to parenteral administration of recombinant proteins. However, achieving effective cellular engraftment of previously retrieved patient cells is challenging. Recently, our ability to engineer vasculature in vivo has allowed for the introduction of instructions into tissues by genetically modifying the vascular cells that build these blood vessels. In the present study, we genetically engineered human blood-derived endothelial colony-forming cells (ECFCs) to express erythropoietin (EPO) under the control of a tetracycline-regulated system, and generated subcutaneous vascular networks capable of systemic EPO release in immunodeficient mice. These ECFC-lined vascular networks formed functional anastomoses with the mouse vasculature, allowing direct delivery of recombinant human EPO into the bloodstream. After activation of EPO expression, erythropoiesis was induced in both normal and anemic mice, a process that was completely reversible. This approach could relieve patients from frequent EPO injections, reducing the medical costs associated with the management of anemia. We propose this ECFC-based gene-delivery strategy as a viable alternative technology when routine administration of recombinant proteins is needed.
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Murua A, Orive G, Hernández RM, Pedraz JL. Emerging technologies in the delivery of erythropoietin for therapeutics. Med Res Rev 2011; 31:284-309. [PMID: 19967731 DOI: 10.1002/med.20184] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Deciphering the function of proteins and their roles in signaling pathways is one of the main goals of biomedical research, especially from the perspective of uncovering pathways that may ultimately be exploited for therapeutic benefit. Over the last half century, a greatly expanded understanding of the biology of the glycoprotein hormone erythropoietin (Epo) has emerged from regulator of the circulating erythrocyte mass to a widely used therapeutic agent. Originally viewed as the renal hormone responsible for erythropoiesis, recent in vivo studies in animal models and clinical trials demonstrate that many other tissues locally produce Epo independent of its effects on red blood cell mass. Thus, not only its hematopoietic activity but also the recently discovered nonerythropoietic actions in addition to new drug delivery systems are being thoroughly investigated in order to fulfill the specific Epo release requirements for each therapeutic approach. The present review focuses on updating the information previously provided by similar reviews and recent experimental approaches are presented to describe the advances in Epo drug delivery achieved in the last few years and future perspectives.
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Affiliation(s)
- Ainhoa Murua
- Laboratory of Pharmacy and Pharmaceutical Technology, Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine, CIBER-BBN, SLFPB-EHU, Faculty of Pharmacy, University of the Basque Country, 01006, Vitoria-Gasteiz, Spain
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Moralejo D, Yanay O, Kernan K, Bailey A, Lernmark A, Osborne W. Sustained glucagon-like peptide 1 expression from encapsulated transduced cells to treat obese diabetic rats. J Biosci Bioeng 2011; 111:383-7. [PMID: 21216666 DOI: 10.1016/j.jbiosc.2010.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/29/2010] [Accepted: 12/07/2010] [Indexed: 12/25/2022]
Abstract
Obesity and type 2 diabetes (T2D) are two prevalent chronic diseases that have become a major public health concern in industrialized countries. T2D is characterized by hyperglycemia and islet beta cell dysfunction. Glucagon-like peptide 1 (GLP-1) promotes β cell proliferation and neogenesis and has a potent insulinotropic effect. Leptin receptor deficient male rats are obese and diabetic and provide a model of T2D. We hypothesized that their treatment by sustained expression of GLP-1 using encapsulated cells may prevent or delay diabetes onset. Vascular smooth muscle cells (VSMC) retrovirally transduced to secrete GLP-1 were seeded into TheraCyte(TM) encapsulation devices, implanted subcutaneously and rats were monitored for diabetes. Rats that received cell implants showed mean plasma GLP-1 level of 119.3 ± 10.2pM that was significantly elevated over control values of 32.4 ± 2.9pM (P<0.001). GLP-1 treated rats had mean insulin levels of 45.9 ± 2.3ng/ml that were significantly increased over control levels of 7.3±1.5ng/ml (P<0.001). In rats treated before diabetes onset elevations in blood glucose were delayed and rats treated after onset became normoglycemic and showed improved glucose tolerance tests. Untreated diabetic rats possess abnormal islet structures characterized by enlarged islets with α-cell infiltration and multifocal vacuolization. GLP-1 treatment induced normalization of islet structures including a mantle of α-cells and increased islet mass. These data suggest that encapsulated transduced cells may offer a potential long term treatment of patients.
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Affiliation(s)
- Daniel Moralejo
- Department of Comparative Medicine, University of Washington, Seattle, WA 98195, USA
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Epo delivery by genetically engineered C2C12 myoblasts immobilized in microcapsules. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 670:54-67. [PMID: 20384218 DOI: 10.1007/978-1-4419-5786-3_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
ver the last half century, the use of erythropoietin (Epo) in the management of malignancies has been extensively studied. Originally viewed as the renal hormone responsible for red blood cell production, many recent in vivo and clinical approaches demonstrate that various tissues locally produce Epo in response to physical or metabolic stress. Thus, not only its circulating erythrocyte mass regulator activity but also the recently discovered nonhematological actions are being thoroughly investigated in order to fulfill the specific Epo delivery requirements for each therapeutic approach.
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Oh TK, Quan GH, Kim HY, Park F, Kim ST. Correction of anemia in uremic rats by intramuscular injection of lentivirus carrying an erythropoietin gene. Am J Nephrol 2006; 26:326-34. [PMID: 16825758 DOI: 10.1159/000094401] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Accepted: 06/07/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND Anemia is an inevitable consequence of chronic renal failure. Gene therapy using lentiviral vector (LV) would be an effective tool to treat anemia associated with renal failure. METHODS A LV carrying the erythropoietin (EPO) cDNA was administered to skeletal muscle of partially nephrectomized rats, which is a model of uremia. The red blood cell production and serum EPO levels were temporally monitored in these rats. Polymerase chain reaction assays were done to validate the presence of the LV in the experimental rats. RESULTS After a single intramuscular injection of LV at a dose of 55 microg p24 Gag antigen (approximately 5 x 10(7) transducing units), blood hematocrit (Hct) levels increased and peaked at 3 weeks (47.8 +/- 4.2%, p < 0.01, n = 8) with the levels being maintained for at least 20 weeks (duration of study; 44.9 +/- 3.3%, p < 0.01, n = 3). The control rats receiving LV expressing lacZ had Hct levels of 36.9 +/- 4.1% (n = 8) at 3 weeks and 33.1 +/- 3.7% (n = 4) at 20 weeks, respectively. The serum EPO levels in the rats injected with the LV expression EPO significantly increased (p < 0.01) to 156.3 +/- 3.0 mU/ml compared to the control rats (63.9 +/- 1.7 mU/ml). Polymerase chain reaction analysis of the isolated genomic DNA from the LV-injected rats showed specific positive detection of the LV in only the skeletal muscle tissue at the site of injection, whereas the other tissues, including the liver, spleen, and kidney, were negative. CONCLUSIONS This study demonstrates that intramuscular injection of LV can produce highly efficient and sustained EPO secretion in uremic rats, and suggests that this approach could be an effective tool to deliver secretable proteins at therapeutic levels in various animal disease models.
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Affiliation(s)
- Tae Keun Oh
- Department of Internal Medicine, Chungbuk National University College of Medicine, Hungdok-Gu, Cheongju, Korea
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Palmquist RE. Shared thoughts on foreign body migration and extrusion . . . . Linking consumer trust with the prosperity of the profession . . . . Importance of public engagement found through involvement in Horse Slaughter Bill . . . . Seasoned professional seeks veteran qualities in younger colleagues. J Am Vet Med Assoc 2005; 226:345-6. [PMID: 15702678 DOI: 10.2460/javma.2005.226.345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Barry S, Brzezinski M, Yanay O, Seppen JE, Osborne WRA. Sustained elevation of neutrophils in rats induced by lentivirus-mediated G-CSF delivery. J Gene Med 2005; 7:1510-6. [PMID: 16041689 DOI: 10.1002/jgm.807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Patients with severe chronic and cyclic neutropenia, characterized by neutrophil numbers <500 cells/microl, are treated daily with recombinant granulocyte colony-stimulating factor (G-CSF). As an alternative delivery approach we investigated the ability of lentivirus vectors to provide sustained G-CSF expression. METHODS Fischer rats were injected intramuscularly (IM) with vesicular stomatitis virus G (VSV-G)-pseudotyped lentivirus pRRL-CMV-G-CSF-SIN that encoded rat G-CSF cDNA regulated by the human cytomegalovirus (CMV) promoter and incorporated a self-inactivating (SIN) construct in the 3' long terminal repeat (LTR). Control rats received normal saline or lentivirus encoding the enhanced green fluorescent protein (eGFP). Rats were serially monitored for blood cell production and tissues assayed for provirus distribution. RESULTS Rats receiving a single IM injection of lentivirus exhibited elevated neutrophil counts for 14 months. Virus administration of 6 x 10(7) infectious units induced sustained levels of neutrophil production having a mean +/- standard deviation (SD) of 5650 +/- 900 cells/microl and rats that received a 10-fold lower dose of virus showed mean neutrophil counts of 3340 +/- 740 cells/microl. These were significantly higher than the mean of control animals receiving saline or control lentivirus (1,760 +/- 540 cells/microl, P < 0.0001). White blood cell (WBC) counts were significantly elevated in treated over control animals (P < 0.0001). Hematocrits (P > 0.3), lymphocytes (P > 0.2) and platelets (P > 0.1) were not significantly different between control and treated animals. Genomic DNA from muscle at the injection sites was positive for provirus, whereas lung, spleen, liver, kidney and non-injected muscle samples were all negative, suggesting lack of virus spread. CONCLUSIONS These studies indicate that lentivirus vectors administered IM provide sustained, therapeutic levels of neutrophils and suggest this approach to treat patients with severe and cyclic neutropenia.
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Affiliation(s)
- Simon Barry
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA
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Eliopoulos N, Lejeune L, Martineau D, Galipeau J. Human-compatible collagen matrix for prolonged and reversible systemic delivery of erythropoietin in mice from gene-modified marrow stromal cells. Mol Ther 2004; 10:741-8. [PMID: 15451458 DOI: 10.1016/j.ymthe.2004.07.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2004] [Accepted: 07/04/2004] [Indexed: 10/26/2022] Open
Abstract
Bone marrow stromal cells (MSCs) can be exploited therapeutically in transgenic cell therapy approaches. Our aim was to determine if gene-modified MSCs sequestered within a clinically approved, bovine type I collagen-based viscous bulking material could serve as a retrievable implant for systemic delivery of erythropoietin (Epo). To test this hypothesis, we embedded Epo-secreting MSCs in viscous collagen (Contigen) and determined the pharmacological effect following implantation in normal mice. Primary MSCs from C57Bl/6 mice were retrovirally engineered to express murine Epo (mEpo) and 10(7) cells of a clonal population secreting 3 U of mEpo/10(6) cells/24 h were implanted subcutaneously in normal C57Bl/6 mice with and without viscous collagen. Without matrix support, Hct rose to >70% for <25 days and returned to baseline by 60 days. However, in mice implanted with viscous collagen-embedded MSCs, the Hct rose to >70% up to 203 days postimplantation (P < 0.0001). In parallel, plasma Epo concentration was significantly increased (P < 0.05) for >145 days. Moreover, surgical removal of the viscous collagen organoid 24 days after implantation led to reduction of Hct to baseline levels within 14 days. In conclusion, this investigation demonstrates that mEpo(+) MSCs embedded in a human-compatible viscous collagen matrix offers a potent, durable, and reversible approach for delivery of plasma-soluble therapeutic proteins.
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Affiliation(s)
- Nicoletta Eliopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
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Yanay O, Barry SC, Flint LY, Brzezinski M, Barton RW, Osborne WRA. Long-Term Erythropoietin Gene Expression from Transduced Cells in Bioisolator Devices. Hum Gene Ther 2003; 14:1587-93. [PMID: 14633401 DOI: 10.1089/104303403322542239] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recombinant erythropoietin (EPO) is widely administered for long-term treatment of anemia associated with renal failure and other chronic diseases. The ability to deliver EPO by gene therapy would have clinical and economic benefit. We compared autologous and allogeneic transduced primary vascular smooth muscle cells for their ability to provide sustained EPO gene expression when encapsulated in TheraCyte devices implanted subcutaneously (SQ) or intraperitoneally (IP) in rats. Cells were transduced with retrovirus vector LrEpSN encoding rat EPO cDNA. Rats that received either autologous or allogeneic transduced cells showed elevated hematocrits (HCTs) ranging from 50 to 79% that were sustained for more than 12 months. The HCT of control rats remained at baseline (45.8%). Rats that received second SQ implants of either autologous or allogeneic cells showed elevations in hematocrit that were sustained for up to 12 months, suggesting the absence of immunological responses to transduced cells or implant material. All experimental groups had statistically significant elevated HCT (p < 0.001) when compared with controls. Both SQ and IP implantation were equally effective in delivering EPO long term. There were no significant differences in white blood cell (WBC) or platelet (PLT) values between treated and control animals. Implantation of TheraCyte devices was well tolerated and histological evaluation of the devices up to 12 months after surgery revealed a high degree of vascularization and no evidence of host immune response. TheraCyte devices offer a simple and safe gene delivery system that provides sustained therapeutic gene expression, permit removal and implantation of new devices, and do not require immunosuppression of the host.
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MESH Headings
- Anemia/therapy
- Animals
- Blood Platelets/metabolism
- Cells, Cultured
- DNA, Complementary/metabolism
- Erythropoietin/biosynthesis
- Erythropoietin/genetics
- Gene Expression
- Genetic Therapy/methods
- Genetic Vectors
- Hematocrit
- Leukocytes/metabolism
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Rats
- Rats, Inbred F344
- Rats, Wistar
- Retroviridae/genetics
- Time Factors
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Affiliation(s)
- Ofer Yanay
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
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Eliopoulos N, Al-Khaldi A, Crosato M, Lachapelle K, Galipeau J. A neovascularized organoid derived from retrovirally engineered bone marrow stroma leads to prolonged in vivo systemic delivery of erythropoietin in nonmyeloablated, immunocompetent mice. Gene Ther 2003; 10:478-89. [PMID: 12621452 DOI: 10.1038/sj.gt.3301919] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Marrow stromal cells (MSCs) are postnatal progenitor cells that can be easily cultured ex vivo to large amounts. This feature is attractive for cell therapy applications where genetically engineered MSCs could serve as an autologous cellular vehicle for the delivery of therapeutic proteins. The usefulness of MSCs in transgenic cell therapy will rely upon their potential to engraft in nonmyeloablated, immunocompetent recipients. Further, the ability to deliver MSCs subcutaneously - as opposed to intravenous or intraperitoneal infusions - would enhance safety by providing an easily accessible, and retrievable, artificial subcutaneous implant in a clinical setting. To test this hypothesis, MSCs were retrovirally engineered to secrete mouse erythropoietin (Epo) and their effect was ascertained in nonmyeloablated syngeneic mice. Epo-secreting MSCs when administered as 'free' cells by subcutaneous or intraperitoneal injection, at the same cell dose, led to a significant - yet temporary - hematocrit increase to over 70% for 55+/-13 days. In contrast, in mice implanted subcutaneously with Matrigel trade mark -embedded MSCs, the hematocrit persisted at levels >80% for over 110 days in four of six mice (P<0.05 logrank). Moreover, Epo-secreting MSCs mixed in Matrigel elicited and directly participated in blood vessel formation de novo reflecting their mesenchymal plasticity. MSCs embedded in human-compatible bovine collagen matrix also led to a hematocrit >70% for 75+/-8.9 days. In conclusion, matrix-embedded MSCs will spontaneously form a neovascularized organoid that supports the release of a soluble plasma protein directly into the bloodstream for a sustained pharmacological effect in nonmyeloablated recipients.
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Affiliation(s)
- N Eliopoulos
- Lady Davis Institute for Medical Research, McGill University, Montreal, Canada
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Seppen J, Barry SC, Harder B, Osborne WR. Lentivirus administration to rat muscle provides efficient sustained expression of erythropoietin. Blood 2001; 98:594-6. [PMID: 11468155 DOI: 10.1182/blood.v98.3.594] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A lentivirus pseudotyped with vesicular stomatitis virus G protein (VSV-G) encoding rat erythropoietin (EPO) complementary DNA was administered to rat skeletal muscle and red blood cell production was serially monitored. After a single intramuscular injection hematocrit values increased and reached a plateau at about 35 days and were sustained for at least 14 months. Virus doses of 6 x 10(7) infectious units and 6 x 10(6) infectious units produced significantly increased mean hematocrit values of 68.5% +/- 2.1% (P <.001, n = 4) and 52.7% +/- 1.3% (P <.001, n = 3), respectively, over values of control animals receiving normal saline (46.2% +/- 1.5%, n = 2). A polymerase chain reaction (PCR) assay for vector sequences in genomic DNA showed muscle tissue at the site of injection was positive and undetectable in liver, spleen, kidney, and lung. The intramuscular administration of lentivirus provided a dose-responsive, highly efficient and sustained EPO gene delivery, suggesting these vectors may be applied generally to the systemic delivery of proteins such as hormones and clotting factors. (Blood. 2001;98:594-596)
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Affiliation(s)
- J Seppen
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA
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Barry SC, Harder B, Brzezinski M, Flint LY, Seppen J, Osborne WR. Lentivirus vectors encoding both central polypurine tract and posttranscriptional regulatory element provide enhanced transduction and transgene expression. Hum Gene Ther 2001; 12:1103-8. [PMID: 11399231 DOI: 10.1089/104303401750214311] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Incorporation of a central polypurine tract (cPPT) and a posttranscriptional regulatory element (PRE) into lentivirus vectors provides increased transduction efficiency and transgene expression. We compared the effects of these elements individually and together on transduction efficiency and gene expression, using lentivirus vectors pseudotyped with vesicular stomatitis virus G protein (VSV-G) and encoding enhanced green fluorescent protein (GFP) and rat erythropoietin (EPO). The transduction efficiency was greater than 2-fold higher in the vector containing the PRE element, 3-fold higher in vector encoding the cPPT element, and 5-fold increased in the GFP virus containing both cPPT and PRE elements relative to the parent virus. In comparison with parent vector the mean fluorescence intensity (MFI) of GFP expression was 7-fold higher in cells transduced with virus containing PRE, 6-fold increased in cells transduced with virus containing cPPT, and 42-fold increased in GFP-virus containing both cPPT and PRE elements. EPO-virus containing a PRE element showed a nearly 5-fold increase in EPO secretion over the parent vector, and the vector encoding both PRE and cPPT showed a 65-fold increase. Thus, lentivirus vectors incorporating both PRE and cPPT showed expression levels significantly increased over the sum of the components alone, suggesting a synergistic effect.
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Affiliation(s)
- S C Barry
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
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Barry SC, Ramesh N, Lejnieks D, Simonson WT, Kemper L, Lernmark A, Osborne WR. Glucose-regulated insulin expression in diabetic rats. Hum Gene Ther 2001; 12:131-9. [PMID: 11177550 DOI: 10.1089/104303401750061195] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Retroviral vectors encoding glucose-responsive promoters driving furin expression may provide an amplified, glucose-regulated secretion of insulin. We constructed LhI*TFSN virus to encode a glucose-regulatable transforming growth factor alpha promoter controlling furin expression with a viral LTR promoter driving constitutive expression of furin-cleavable human proinsulin. Autologous BB rat vascular smooth muscle cells transduced with LhI*TFSN virus and cultured in 1.7 and 16.7 mM glucose secreted 50.7 +/- 3.2 and 136.0 +/- 11.0 microU (mean +/- SD) of insulin per 10(6) cells per day, respectively. After the onset of diabetes spontaneously diabetic congenic DR lyp/lyp BB rats received stomach implants containing 2 x 10(6) LhI*TFSN-transduced primary rat vascular smooth muscle cells. In eight treated rats there was a major reduction in insulin requirement to as low as 25% of pretreatment level for up to 3 months and one rat became insulin free without hypoglycemia. Intraperitoneal glucose tolerance tests (IPGTTs) in diabetic rats receiving control implants did not show the characteristic decline in blood glucose of normal rats after glucose administration. In contrast, diabetic rats receiving LhI*TFSN-transduced cells showed significant clearances of blood glucose. These data suggest clinically significant levels of glucose-regulated insulin delivery from implanted vascular smooth muscle cells transduced with LhI*TFSN vector.
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Affiliation(s)
- S C Barry
- Department of Pediatrics, Seattle, WA 98195, USA
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