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Baohong Cao

Publications and source records attributed to Baohong Cao.

11 recordsLinked to original sources
PubMed2006

Mouse adipose-derived stem cells undergo multilineage differentiation in vitro but primarily osteogenic and chondrogenic differentiation in vivo.

Human, rat, and mouse studies have demonstrated the existence of a population of adipose-derived adult stem (ADAS) cells that can undergo multilineage differentiation in vitro. However, it remains unclear whether these cells maintain their multilineage potential in vivo. The aim of this study was to examine the in vitro and in vivo characteristics and behavior of a potential population of murine ADAS (muADAS) cells isolated from the visceral fat of the abdominal cavity of C57BL/10J mice. We used flow cytometry to examine the cells' expression of CD29, CD31, CD45, CD34, CD44, CD144, CD146, Flk1, and Sca-1. The isolated cell population was CD45 negative, which precludes contamination by hematopoietic cells, but was partially positive for Sca-1 and CD34: 2 stem-cell markers. After induction in conditioned medium, the muADAS cells gained the ability to undergo adipogenic, osteogenic, chondrogenic, myogenic, and hematopoietic differentiation in vitro. The muADAS cells readily differentiated to form bone and cartilage in vivo for up to 24 weeks, but their ability to regenerate muscle or reconstitute bone marrow was found to be limited.

Adipose Tissue↗
PubMed2004

Ex vivo gene transfer to mature skeletal muscle by using adenovirus helper cells.

BACKGROUND: Adenoviral gene transfer to adult skeletal muscle is hindered by several major limitations, including host immune responses and maturation-dependent loss of myofiber infectivity. Ex vivo gene delivery is more efficient than direct viral injection in surmounting maturation-dependent adenoviral transduction. Here we investigated the use of helper cells to improve the efficiency of ex vivo gene transfer to adult mouse skeletal muscle. METHODS: New producer cells carrying the E1 gene of adenovirus type 5 (E32 cells) were developed using primary myoblasts from mdx mice. The E32 cells and 293 cells were infected with an E1-deleted first-generation adenovirus carrying the LacZ gene. These transduced helper cells were injected into the skeletal muscle of adult mdx and SCID mice. RESULTS: LacZ-positive mature myofibers were detected in the skeletal muscle of adult mice sacrificed 5 days post-injection. The gene transfer efficiency using 293 cells and E32 cells was 6.2 and 3.6 times higher than myoblast-mediated gene transfer, respectively. Ex vivo gene transfer of these cell types led to a better outcome than did direct adenoviral injection. CONCLUSIONS: We achieved more efficient adenoviral gene transduction by using 293 and E32 helper cells than by myoblast-mediated gene transfer and direct viral injection. These helper cells also enabled adenoviral gene transfer to mature myofibers. The mechanisms by which this method facilitated adenoviral gene transfer to mature myofibers remains unclear; however, we hypothesize that the in vivo occurrence of cytopathic effects (CPE) in the transduced 293 and E32 helper cell populations facilitated the improved adenoviral transduction of myofibers.

Adenoviridae↗
PubMed2004

Gene transfer to skeletal muscle using herpes simplex virus-based vectors.

Type 1 herpes simplex virus (HSV-1)-based vectors, which are naturally capable of carrying large DNA fragments like the 14 kb dystrophin cDNA, have been studied for their ability to transduce muscle cells. These vectors can persist in the host cell in a nonintegrated state and can be prepared at adequately high titers (10(7)-10(9) PFU/mL). They also infect myoblasts, myotubes, and immature myofibers efficiently. The major disadvantage of the first-generation HSV vectors is their relatively high cytotoxicity, which hampers long-term transgene expression. Second-generation mutants defective for multiple immediate early (IE) genes (e.g., ICP4, ICP22, and ICP27) display substantially reduced cytotoxicity in vitro, which improves the duration of transgene expression (6-11). In this chapter, we describe a new method of gene delivery using second-generation HSV-1 vectors. This procedure should enable an investigator to transduce normal mouse muscle cells, both in vitro and in vivo. We explain the conditions for muscle cell isolation, transduction in vitro and in vivo, and the technique for evaluating transduction efficiency (beta-galactosidase; beta-gal) using histology or the beta-gal assay (ONPG) method.

Animals↗
PubMed2004

Muscle-derived stem cells.

Researchers have identified 2 types of stem cells in skeletal muscle: satellite cells and multipotent stem cells (MPSCs). The latter category includes different cell populations isolated by various researchers using several techniques. The methods used to isolate these cells appear to influence the stem cell characteristics of the MPSCs. Although MPSCs and satellite cells could represent different stages of maturation of the same progenitor cells, they also could represent distinct populations of stem cells that exist in skeletal muscle. This article summarizes the recent developments in muscle-derived stem cell research.

Animals↗
PubMed2003

Dystrophin delivery in dystrophin-deficient DMDmdx skeletal muscle by isogenic muscle-derived stem cell transplantation.

Duchenne's muscular dystrophy (DMD) is a lethal muscle disease caused by a lack of dystrophin expression at the sarcolemma of muscle fibers. We investigated retroviral vector delivery of dystrophin in dystrophin-deficient DMD(mdx) (hereafter referred to as mdx) mice via an ex vivo approach using mdx muscle-derived stem cells (MDSCs). We generated a retrovirus carrying a functional human mini-dystrophin (RetroDys3999) and used it to stably transduce mdx MDSCs obtained by the preplate technique (MD3999). These MD3999 cells expressed dystrophin and continued to express stem cell markers, including CD34 and Sca-1. MD3999 cells injected into mdx mouse skeletal muscle were able to deliver dystrophin. Though a relatively low number of dystrophin-positive myofibers was generated within the gastrocnemius muscle, these fibers persisted for up to 24 weeks postinjection. The injection of cells from additional MDSC/Dys3999 clones into mdx skeletal muscle resulted in varying numbers of dystrophin-positive myofibers, suggesting a differential regenerating capacity among the clones. At 2 and 4 weeks postinjection, the infiltration of CD4- and CD8-positive lymphocytes and a variety of cytokines was detected within the injected site. These data suggest that the transplantation of retrovirally transduced mdx MDSCs can enable persistent dystrophin restoration in mdx skeletal muscle; however, the differential regenerating capacity observed among the MDSC/Dys3999 clones and the postinjection immune response are potential challenges facing this technology.

Animals↗
PubMed2003

Muscle-derived stem cells: potential for muscle regeneration.

Duchenne muscular dystrophy (DMD) is a devastating X-linked muscle disease characterized by progressive muscle weakness caused by the lack of dystrophin expression at the sarcolemma of muscle fibers. Although various approaches to delivering dystrophin in dystrophic muscle have been investigated extensively (e.g., cell and gene therapy), there is still no treatment that alleviates the muscle weakness in this common inherited muscle disease. The transplantation of myoblasts can enable transient delivery of dystrophin and improve the strength of injected dystrophic muscle, but this approach has various limitations, including immune rejection, poor cellular survival rates, and the limited spread of the injected cells. The isolation of muscle cells that can overcome these limitations would enhance the success of myoblast transplantation significantly. The efficiency of cell transplantation might be improved through the use of stem cells, which display unique features, including (1) self-renewal with production of progeny, (2) appearance early in development and persistence throughout life, and (3) long-term proliferation and multipotency. For these reasons, the development of muscle stem cells for use in transplantation or gene transfer (ex vivo approach) as treatment for patients with muscle disorders has become more attractive in the past few years. In this paper, we review the current knowledge regarding the isolation and characterization of stem cells isolated from skeletal muscle by highlighting their biological features and their relationship to satellite cells as well as other populations of stem cells derived from other tissues. We also describe the remarkable ability of stem cells to regenerate skeletal muscle and their potential use to alleviate the muscle weakness associated with DMD.

Animals↗
PubMed2003

Muscle stem cells differentiate into haematopoietic lineages but retain myogenic potential.

Muscle-derived stem cells (MDSCs) can differentiate into multiple lineages, including haematopoietic lineages. However, it is unknown whether MDSCs preserve their myogenic potential after differentiation into other lineages. To address this issue, we isolated from dystrophic muscle a population of MDSCs that express stem-cell markers and can differentiate into various lineages. After systemic delivery of three MDSC clones into lethally irradiated mice, we found that differentiation of the donor cells into various lineages of the haematopoietic system resulted in repopulation of the recipients' bone marrow. Donor-derived bone-marrow cells, isolated from these recipients by fluorescence-activated cell sorting (FACS), also repopulated the bone marrow of secondary, lethally irradiated, recipients and differentiated into myogenic cells both in vitro and in vivo in normal mdx mice. These findings demonstrate that MDSC clones retain their myogenic potential after haematopoietic differentiation.

Animals↗
PubMed2002

The role of CD34 expression and cellular fusion in the regeneration capacity of myogenic progenitor cells.

Characterization of myogenic subpopulations has traditionally been performed independently of their functional performance following transplantation. Using the preplate technique, which separates cells based on their variable adhesion characteristics, we investigated the use of cell surface proteins to potentially identify progenitors with enhanced regeneration capabilities. Based on previous studies, we used cell sorting to investigate stem cell antigen-1 (Sca-1) and CD34 expression on myogenic populations with late adhesion characteristics. We compared the regeneration efficiency of these sorted progenitors, as well as those displaying early adhesion characteristics, by quantifying their ability to regenerate skeletal muscle and restore dystrophin following transplantation into allogenic dystrophic host muscle. Identification and utilization of late adhering populations based on CD34 expression led to differential regeneration, with CD34-positive populations exhibiting significant improvements in dystrophin restoration compared with both their CD34-negative counterparts and early adhering cell populations. Regenerative capacity was found to correspond to the level of myogenic commitment, defined by myogenic regulatory factor expression, and the rate and degree of induced cell differentiation and fusion. These results demonstrate the ability to separate definable subpopulations of myogenic progenitors based on CD34 expression and reveal the potential implications of defining myogenic cell behavioral and phenotypic characteristics in relation to their regenerative capacity in vivo.

Animals↗
PubMed2002

Adenovirus mediated gene transfer to skeletal muscle.

Transfer of therapeutic genes into muscle tissue has promise for the treatment of a variety of muscular dystrophies. Various vectors have been used to deliver genes to skeletal muscle but their application has faced several major limitations including: (1) the lack of transgene persistence caused by the immune rejection of transduced myofibers and/or vector toxicity, and (2) the maturation dependence of viral transduction. While the immunorejection and/or cytotoxic problems are being overcome with the development of new vectors, maturation-dependent viral transduction is still a major hurdle in gene transfer to skeletal muscle. Poor adenoviral transduction in mature myofibers has been attributed to: (1) the extracellular matrix of mature myofibers may form a physical barrier and prevent the passage of large viral particles; (2) viral receptors are down-regulated with muscle maturation; and (3) loss of myoblasts with muscle maturation, which serve as intermediaries in the viral transduction. In this review, we will focus on recent developments in overcoming those hurdles of gene therapy in skeletal muscle, especially to adenovirus (Ad), including: (1) new mutant vectors lacking all viral genes to decrease immunogenicity, and hence, improve persistence of transgene expression in muscle in vivo; (2) using tissue specific promoters to evade immunorejection; (3) permeabilization of the extracellular matrix; (4) modifying the viral receptors in mature myofibers; and (5) myoblast or muscle stem cell mediated ex vivo gene transfer.

Adenoviridae↗
PubMed2002

Identification of a novel population of muscle stem cells in mice: potential for muscle regeneration.

Three populations of myogenic cells were isolated from normal mouse skeletal muscle based on their adhesion characteristics and proliferation behaviors. Although two of these populations displayed satellite cell characteristics, a third population of long-time proliferating cells expressing hematopoietic stem cell markers was also identified. This third population comprises cells that retain their phenotype for more than 30 passages with normal karyotype and can differentiate into muscle, neural, and endothelial lineages both in vitro and in vivo. In contrast to the other two populations of myogenic cells, the transplantation of the long-time proliferating cells improved the efficiency of muscle regeneration and dystrophin delivery to dystrophic muscle. The long-time proliferating cells' ability to proliferate in vivo for an extended period of time, combined with their strong capacity for self-renewal, their multipotent differentiation, and their immune-privileged behavior, reveals, at least in part, the basis for the improvement of cell transplantation. Our results suggest that this novel population of muscle-derived stem cells will significantly improve muscle cell-mediated therapies.

Animals↗