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Yaoguang Zhang

Publications and source records attributed to Yaoguang Zhang.

7 recordsLinked to original sources
PubMed2025

Validation of caprine H11 and the Rosa26 platform for transgene integration via CRISPR-based system: investigations on stable transgene expression and genetic biosafety.

CRISPR/Cas9 technology is an efficient tool for site-specific livestock gene editing. However, to minimize potential disruption of host genome function, exogenous genes should be integrated into well-characterized genomic loci, such as H11 or Rosa26, which have been empirically validated for stable transgene expression. This study established a multi-dimensional assessment system to evaluate the biological applicability of the H11 locus and the widely used Rosa26 targeting platform as sites for targeted integration of exogenous genes in goats. Donor cells carrying the enhanced green fluorescent protein (EGFP) reporter gene at the H11 and Rosa26 loci were generated via CRISPR/Cas9-mediated homology-directed repair; this was followed by somatic cell nuclear transfer to produce transgenic cloned embryos and healthy offspring. Multi-dimensional analyses revealed the following. At the cellular level, there was stable and efficient EGFP expression at integration sites, with donor cells maintaining normal cell cycle progression, proliferation capacity, and apoptosis levels, and with no alterations in the transcriptional integrity of adjacent genes. At the embryonic level, there was sustained EGFP expression across pre-implantation embryonic stages, with developmental metrics statistically indistinguishable from wild-type embryos. Finally, at the individual level, cloned offspring exhibited growth phenotypes consistent with wild-type counterparts, and EGFP showed broad-spectrum expression in eight tissues. This study establishes the first CRISPR/Cas9-based crossscale (cellular-embryonic-individual) validation in goats, demonstrating that the H11 and Rosa26 loci support efficient and stable transgene integration in goats. These results provide a precise and predictable technical framework for livestock genetic improvement.

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PubMed2005

Maximizing ventricular function with multimodal cell-based gene therapy.

BACKGROUND: Angiogenesis is enhanced after transplantation of vascular endothelial growth factor (VEGF)-expressing cells into a myocardial scar. Insulin-like growth factor I (IGF-I) may induce hypertrophy and inhibit apoptosis. We evaluated the effect of cell-based IGF-I and VEGF multigene therapy on left ventricular (LV) function, cell survival, and apoptosis after bone marrow cell (BMC) transplantation. METHODS AND RESULTS: Female Lewis rats underwent left anterior descending ligation 3 weeks before transplantation with male donor BMC, BMC transfected with VEGF (BMC+VEGF), IGF-I (BMC+IGF-I), VEGF and IGF-I (BMC+VEGF+IGF-I), or medium without cells (control) (n=4 per group x 5 groups x 4 time points). Three days and 1, 2, and 4 weeks after transplantation, VEGF and IGF-I expression was quantitated by real-time polymerase chain reaction, cell survival by polymerase chain reaction for sry2, apoptosis by TUNEL staining, LV function by echocardiography and myosin heavy chain, and light chain and troponin I by Western blot. One week after transplantation, IGF-I expression in the scar and border zone was greatest in BMC+IGF-I and BMC+VEGF+IGF-I rats (P<0.05). VEGF expression in the scar and border zone was greatest in BMC+VEGF and BMC+VEGF+IGF-I hearts (P<0.05). Transplanted cell survival was lowest in BMC, intermediate in BMC+VEGF and BMC+IGF-I, and greatest in BMC+VEGF+IGF-I (P<0.05). Apoptotic indices were significantly reduced in BMC+VEGF+IGF-I, BMC+VEGF, and BMC+IGF-I (P<0.05). Two and 4 weeks after transplantation, LV ejection fraction was lowest in control, intermediate in BMC, BMC+VEGF, and BMC+IGF-I, and greatest in BMC+VEGF+IGF-I (P<0.05). CONCLUSIONS: Transplantation of VEGF- and IGF-I-expressing BMC reduced apoptosis, maximized transplanted cell survival, and enhanced LV function. Multimodal cell-based gene therapy may maximize the benefits of cell transplantation.

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PubMed2005

Vascular endothelial growth factor receptor upregulation in response to cell-based angiogenic gene therapy.

BACKGROUND: We have previously reported that transplantation of vascular endothelial growth factor transfected cells into myocardial scar enhances angiogenesis. We evaluated the effect of transplanted cell type, time, and region of the heart on expression of the vascular endothelial growth factor receptors fms-like tyrosine kinase-1 (flt-1) and fetal liver kinase-1 (flk-1). METHODS: Lewis rats underwent myocardial cryoinjury 3 weeks before transplantation with heart cells (a mixed culture of cardiomyocytes, smooth muscle cells, endothelial cells, and fibroblasts), vascular endothelial growth factor transfected heart cells, skeletal myoblasts, vascular endothelial growth factor transfected skeletal myoblasts, or medium (controls) (N = 13 each). Flt-1 and flk-1 expression in the scar, border zone, and normal myocardium were evaluated at 3 days and 1, 2, and 4 weeks by quantitative polymerase chain reaction. Transplanted cells, vascular endothelial growth factor, flt-1, and flk-1 were identified by immunohistology. RESULTS: Flt-1 and flk-1 levels were low in all areas of control hearts. Upregulation of flt-1 and flk-1 after cell transplantation occurred primarily in host cells in the border zone rather than the scar (zone, p < 0.0001). Flt-1 and flk-1 expression was doubled by heart cells and skeletal myoblasts and increased eightfold by vascular endothelial growth factor transfected heart cells and skeletal myoblasts (group, p < 0.0001). Flk-1 expression peaked at 1 week, whereas flt-1 peaked at 2 weeks (time, p < 0.0001). CONCLUSIONS: Flk-1 and flt-1 upregulation may mediate the angiogenic effect of cell transplantation and are augmented by vascular endothelial growth factor transgene expression, perhaps through a paracrine effect. Optimizing the angiogenic response to cell transplantation may maximize the benefit of cell transplantation strategies.

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PubMed2005

Increasing transplanted cell survival with cell-based angiogenic gene therapy.

BACKGROUND: The majority of cells transplanted into infarcted myocardium do not survive. Maximizing cell survival should maximize the efficacy of cell transplantation for myocardial repair. We evaluated the role of apoptosis in cell loss after transplantation and the effect of angiogenesis on apoptosis and overall cell survival. METHODS: Female Lewis rats underwent myocardial cryoinjury 3 weeks before transplantation with male heart cells (a mixed culture of cardiomyocytes, smooth muscle cells, endothelial cells, and fibroblasts), vascular endothelial growth factor-transfected heart cells, skeletal myoblasts, vascular endothelial growth factor-transfected skeletal myoblasts (n = 6 each), or medium (control, n = 5). One week later, transplanted cell survival and apoptosis were quantitated by real-time polymerase chain reaction for Y chromosomal deoxyribonucleic acid, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay and deoxyribonucleic acid fragmentation. RESULTS: Approximately one third of heart cells and skeletal myoblasts survived 1 week after transplantation, and one half of vascular endothelial growth factor-transfected heart cells and skeletal myoblasts survived to this time (p < 0.05). Apoptosis was greatest in heart cell and skeletal myoblast-transplanted hearts (p < 0.05), reduced in the vascular endothelial growth factor-transfected groups (p < 0.05) and lowest in controls. CONCLUSIONS: Ischemia and apoptosis both contribute to cell loss after transplantation. Transfection with vascular endothelial growth factor induced angiogenesis, which reduced both ischemic and apoptotic cell death. Our findings suggest that further strategies to reduce apoptosis may enhance the efficacy of cell transplantation in myocardial repair.

Animals↗
PubMed2005

Phylogeny and biogeography of Chinese sisorid catfishes re-examined using mitochondrial cytochrome b and 16S rRNA gene sequences.

The family Sisoridae is one of the largest and most diverse Asiatic catfish families, most species occurring in the water systems of the Qinhai-Tibetan Plateau and East Himalayas. To date published morphological and molecular phylogenetics hypotheses of sisorid catfishes are part congruent, and there are some areas of significant disagreement with respect to intergeneric relationships. We used mitochondrial cytochrome b and 16S rRNA gene sequences to clarify existing gaps in phylogenetics and to test conflicting vicariant and dispersal biogeographical hypotheses of Chinese sisorids using dispersal-vicariance analysis and weighted ancestral area analysis in combination with palaeogeographical data as well as molecular clock calibration. Our results suggest that: (1) Chinese sisorid catfishes form a monophyletic group with two distinct clades, one represented by (Gagata (Bagarius, Glyptothorax)) and the other by (glyptosternoids, Pseudecheneis); (2) the glyptosternoid is a monophyletic group and Glyptosternum, Glaridoglanis, and Exostoma are three basal species having a primitive position among it; (3) a hypothesis referring to Pseudecheneis as the sister group of the glyptosternoids, based on morphological evidence, is supported; (4) the genus Pareuchiloglanis, as presently defined, is not monophyletic; (5) congruent with previous hypotheses, the uplift of Qinghai-Tibetan Plateau played a primary role in the speciation and radiation of the Chinese sisorids; and (6) an evolutionary scenario combining aspects of both vicariance and dispersal theory is necessary to explain the distribution pattern of the glyptosternoids. In addition, using a cytochrome b substitution rate of 0.91% per million years and 0.23% for 16S rRNA, we tentatively date that the glyptosternoids most possibly originated in Oligocene-Miocene boundary (19-24Myr), and radiated from Miocene to Pleistocene, along with a center of origin in the Irrawaddy-Tsangpo drainages and several rapid speciation in a relatively short time.

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PubMed2004

Phylogenetic relationships of glyptosternoid fishes (Siluriformes: Sisoridae) inferred from mitochondrial cytochrome b gene sequences.

To explore phylogenetic relationships among glyptosternoid fishes, we determined nucleotide sequences of the complete mitochondrial cytochrome b gene region (1138 base pair). Thirteen species of glyptosternoid fishes and six species of non-glyptosternoids represent 10 sisorid genera were examined. Molecular phylogenetic trees were constructed using the maximum parsimony, minimum evolution, maximum likelihood, and Bayesian methods. Bayesian and maximum likelihood analyses support the monophyly of glyptosternoids, but our hypothesis of internal relationships differs from previous hypothesis. Results indicated that glyptosternoid is a monophyletic group and genera Glyptosternum and Exostoma are two basal species having a primitive position among it. Genera Euchiloglanis and Pareuchiloglanis form a sister-group. Then they form a sister-group with Pseudexostoma plus Oreoglanis. Our result also found that Pareuchiloglanis anteanalis might be considered as the synonyms of Parechiloglanis sinensis, and genus Euchiloglanis might have only one valid species, Euchiloglanis davidi.

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