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Biomedical subjects

Lisheng Wang

Publications and source records attributed to Lisheng Wang.

At least 19 recordsLinked to original sources
PubMed2025

Chromosomal instability by low-coverage whole-genome sequencing assay predicts prognosis in bladder cancer patients underwent radical cystectomy.

PURPOSE: To investigate chromosomal instability (CIN) in tumor tissue from radical bladder resection and to evaluate whether it can be used as a biomarker for the molecular typing of (BC). METHODS: DNA was extracted from formalin-fixed paraffin-embedded samples of 50 BC patients who were followed up to March 23 2023 using the Qiagen nucleic acid kits. We analyzed CIN in tumor of bladder by low-coverage whole genome sequencing (LC-WGS). Kaplan-Meier log-rank test was used to perform survival analysis. The association between variables and overall and progression-free survival was analyzed using the Cox proportional hazards model. RESULTS: There were 44 genome segments with statistically significant changes in copy number. CIN was significantly correlated with tumor stage, lymph node metastasis, relapse and survival status. Patients with high CIN were found to have a worse survival, with a median overall survival (OS) of 15 months. In addition, patients with high CIN were more likely to relapse, with a median progression-free survival (PFS) of 7 months. Patients with low CIN showed better OS and PFS. However, there was no significant difference in OS and PFS between T2 and T3-T4 patients. Multivariate cox regression analysis showed that high CIN was an independent predictor of OS, and high CIN and muscle invasion were independent predictors of PFS. Furthermore, patients with abnormal copy number of a single chromosome also had a poor prognosis, with a median survival of 14-30 months for OS and 5-10 months for PFS, while negative patients had a better prognosis. CONCLUSION: CIN was significantly correlated with tumor stage, lymph node metastasis, relapse and survival status of BC. Patients with high CIN or abnormal copy numbers of a single chromosome have a poor prognosis. CIN might be better than T stage in predicting the prognosis of patients with BC. Molecular typing of CIN can be used as an independent prognostic factor for BC.

Humans↗
PubMed2006

Adenoviral-mediated gene expression of hepatocyte growth factor prevents postoperative peritoneal adhesion in a rat model.

BACKGROUND: Mesothelial cell proliferation and migration play important roles in reducing formation of postoperative peritoneal adhesions. Hepatocyte growth factor (HGF) is a multifunctional cytokine that stimulates proliferation and migration of various cell types, including mesothelial cells. METHODS: We investigated the effect of adenovirus-mediated HGF gene expression on the proliferation and migration of mesothelial cells and evaluated its preventive effects on postoperative formation of peritoneal adhesions. Rat mesothelial cells were isolated and characterized by expression of cytokeratin and vimentin. RESULTS: Immunohistochemical staining showed that these cells expressed c-Met, the receptor for HGF. Adenoviral-mediated HGF gene transfer into mesothelial cells resulted in high expression of HGF and enhanced migration. To evaluate the preventive effects of adenoviral-mediated HGF gene transfer on the formation of postoperative peritoneal adhesion, we employed a rat model of cecum abrasion-induced adhesion formation in which 80% of the rats developed postoperative peritoneal adhesions. Local application of recombinant adenovirus carrying the HGF gene reduced adhesion formation in 16 of 20 control rats compared with 7 of 20 treated rats in this model. CONCLUSIONS: These results suggest that adenoviral-mediated HGF gene transfer may be a novel strategy for preventing postoperative peritoneal adhesions.

Adenoviridae↗
PubMed2006

Endothelial and hematopoietic cell fate of human embryonic stem cells.

The endothelial cells, lining the inside of blood vessels, and the blood-forming hematopoietic cells play crucial roles in vasculogenesis. The establishment of human embryonic stem cells (hESCs) provides a unique tool to study the early development of endothelial and hematopoietic cells, opening new avenues of research to explore organ vascularization and regeneration. The current study demonstrates that a population of intermediate-stage precursors, which possesses primitive endothelial properties during hESC differentiation, is capable of giving rise to endothelial and hematopoietic cells. Single cell analysis reveals that these primitive endothelial-like precursors contain rare bipotent cells with hemangioblast properties, responsible for both endothelial and hematopoietic cell fates. These findings will facilitate the further study of cellular commitment, lineage restriction, and terminal differentiation of endothelial and hematopoietic compartments and may lead to novel regenerative therapies.

Animals↗
PubMed2006

Derivation and characterization of hematopoietic cells from human embryonic stem cells.

In vitro, the aggregation of pluripotent human embryonic stem cells (hESC) into cell clusters termed embryoid bodies (EB) allows for the spontaneous differentiation of hESC into progeny representing endoderm, mesoderm, and ectoderm lineages. During human EB (hEB) differentiation, stochastic emergence of hematopoietic cells can be enhanced by a combination of hematopoietic cytokines and the ventral mesoderm inducer bone morphogenetic protein (BMP)-4. Dependent on the presence of hematopoietic cytokines and BMP-4, vascular endothelial growth factor (VEGF-A165) selectively promotes erythropoietic development toward the primitive lineage. The effects of VEGF-A165 can be augmented by erythropoietin (EPO). Hematopoietic cells are derived from a rare subpopulation of hemogenic precursors during hEB development. These hemogenic precursors lack CD45, but express PECAM-1, Flk-1, and VE-cadherin (hereinafter CD45(neg)PFV) and are solely responsible for hematopoietic cell fate. Human ESC-derived hematopoietic cells have similar colony and cellular morphologies to those derived from committed adult hematopoietic tissues, and also show repopulating capacity in immune deficient mice after intrabone marrow transplantation. In this chapter, we describe methods that have been successfully applied in our laboratory, including (1) generation of hematopoietic cells by EB formation; (2) augmentation of hematopoiesis by use of hematopoietic cytokines and BMP-4; (3) promotion of erythropoietic development by addition of VEGF-A165 and EPO; (4) isolation of CD45(neg)PFV hemogenic precursors and generation of hematopoietic cells from these precursors; and (5) characterization of hESC-derived hematopoietic cells in vitro and in vivo.

Animals↗
PubMed2006

Retroviral transduction of hematopoietic progenitors derived from human embryonic stem cells.

It has been recently identified that cytokines and BMP-4 promote hematopoiesis from human embryonic stem cells (hESC) and that, before hematopoietic commitment, a rare subpopulation of cells lacking CD45, but expressing PECAM-1, Flk-1, and VE-cadherin (hereinafter termed CD45(neg)PFV precursors), are exclusively responsible for hematopoietic cell fate on cytokine stimulation. Efficient strategies to stably transduce these hematopoietic precursors specifically generated from hESCs would provide a novel and desirable tool to study hematopoietic development through the introduction and characterization of candidate genes suspected to regulate self-renewal processes of hESC-derived hematopoietic cells or dynamically track hESC-derived hematopoietic stem cells in vivo. To date, only transient transfection and stable transduction using lentiviral vectors have been reported in undifferentiated hESC followed by random and spontaneous differentiation into different cell types. However, protocols for stable transduction of hematopoietic progenitors prospectively derived from hESC need to be developed yet. In the present chapter, we described detailed methods on the recently characterized and optimized GALV-pseudotyped retroviral gene transfer strategy to stably transduce the hematopoietic progenitor cells prospectively derived from CD45(neg)PFV hemogenic precursors as a vital tool to study hematopoietic development and to characterize candidate genes suspected to eventually confer robust and sustained repopulating ability to hESC-derived hematopoietic cells.

Antigens, CD↗
PubMed2005

Effects of exogenous FGF-1 treatment on regeneration of the lens and the neural retina in the newt, Notophthalmus viridescens.

Experiments were designed to compare the effects of recombinant newt fibroblast growth factor-1 (rnFGF-1) and recombinant human glial growth factor (rhGGF) on lens and retina regeneration in the eyes of adult newts. Both eyes were retinectomized and lentectomized. Beginning 3 days after the operation, one eye was given either 0.1 microg of rnFGF-1 or 0.1 microg of rhGGF in 1 microl of phosphate-buffered saline (PBS) per injection, three per week. Contralateral operated eyes served as controls and were treated with PBS alone or were not injected. In eyes that were not injected, injected with PBS alone, or with PBS containing rhGGF, regeneration of both the retina and the lens proceeded normally as described in the literature. In these control eyes, the entire retinal pigmented epithelium (RPE) depigmented/dedifferentiated and a retina rudiment formed from which a new retina regenerated by the end of the experiment at day 41 post-operation. Likewise, only a small area of dorsal iris depigmented/dedifferentiated and formed a lens vesicle from which a lens subsequently regenerated. The vitreous remained relatively free of loose cells. In eyes given rnFGF-1, the RPE depigmented/dedifferentiated and formed what appeared to be a retina rudiment but a new retina did not regenerate. Instead, vesicles were seen associated with the retina rudiment. In eyes given rnFGF-1, both the dorsal iris and ventral iris depigmented/dedifferentiated and lens regeneration occurred but the new lenses had abnormal fiber cells and the lens epithelium was very thin or absent. In addition, ectopic lenses usually regenerated in rnFGF-1-treated eyes. An abundance of loose cells were present in the vitreous of rnFGF-1-treated eyes associated largely with the RPE and the dorsal and ventral irises. The results are consistent with the view that the timely expression of FGFs is involved in the depigmentation/dedifferentiation of the RPE and dorsal iris and is necessary for proper regeneration of the lens and neural retina. Continued presence of FGF results in continued and excessive dedifferentiation, resulting in the lack of retina regeneration and abnormal lens regeneration.

Animals↗
PubMed2005

Mycobacterium tuberculosis regulates CD1 antigen presentation pathways through TLR-2.

Mycobacterium tuberculosis remains a major pathogen of worldwide importance, which releases lipid Ags that are presented to human T cells during the course of tuberculosis infections. Here we report that cellular infection with live M. tuberculosis or exposure to mycobacterial cell wall products converted CD1- myeloid precursors into competent APCs that expressed group 1 CD1 proteins (CD1a, CD1b, and CD1c). The appearance of group 1 CD1 proteins at the surface of infected or activated cells occurred via transcriptional regulation, and new CD1 protein synthesis and was accompanied by down-regulation of CD1d transcripts and protein. Isolation of CD1-inducing factors from M. tuberculosis using normal phase chromatography, as well as the use of purified natural and synthetic compounds, showed that this process involved polar lipids that signaled through TLR-2, and we found that TLR-2 was necessary for the up-regulation of CD1 protein expression. Thus, mycobacterial cell wall lipids provide two distinct signals for the activation of lipid-reactive T cells: lipid Ags that activate T cell receptors and lipid adjuvants that activate APCs through TLR-2. These dual activation signals may represent a system for selectively promoting the presentation of exogenous foreign lipids by those myeloid APCs, which come into direct contact with pathogens.

Animals↗
PubMed2005

Synthesis of nano/micro zinc oxide rods and arrays by thermal evaporation approach on cylindrical shape substrate.

Nano and micro ZnO rods and arrays have been synthesized by a simple thermal evaporation approach on a cylindrical shape substrate. Most of the synthesized ZnO products are single crystalline with a hexagonal structure and grow along the [0001] direction. Individual protrusive ZnO rods and well-aligned arrays are two typical products in our work. The individual protrusive ZnO rods have diameters of 25 nm approximately 2.1 microm and lengths from several hundred nanometers to 40 microm, while in the well-aligned arrays, the diameter and length of each ZnO rod range from 60 nm to 1.2 microm and from 4 microm to 6 microm, respectively. The heating temperature and deposition position are two key points to control the diameters of the rods. The growth mechanism is discussed and proposed. The perfect crystalline ZnO rods with different scales from nanometer to micrometer are good models for the investigation of the size effect of physical and chemical properties of one-dimensional material.

Journal Article↗
PubMed2005

Generation of hematopoietic repopulating cells from human embryonic stem cells independent of ectopic HOXB4 expression.

Despite the need for alternative sources of human hematopoietic stem cells (HSCs), the functional capacity of hematopoietic cells generated from human embryonic stem cells (hESCs) has yet to be evaluated and compared with adult sources. Here, we report that somatic and hESC-derived hematopoietic cells have similar phenotype and in vitro clonogenic progenitor activity. However, in contrast with somatic cells, hESC-derived hematopoietic cells failed to reconstitute intravenously transplanted recipient mice because of cellular aggregation causing fatal emboli formation. Direct femoral injection allowed recipient survival and resulted in multilineage hematopoietic repopulation, providing direct evidence of HSC function. However, hESC-derived HSCs had limited proliferative and migratory capacity compared with somatic HSCs that correlated with a distinct gene expression pattern of hESC-derived hematopoietic cells that included homeobox (HOX) A and B gene clusters. Ectopic expression of HOXB4 had no effect on repopulating capacity of hESC-derived cells. We suggest that limitations in the ability of hESC-derived HSCs to activate a molecular program similar to somatic HSCs may contribute to their atypical in vivo behavior. Our study demonstrates that HSCs can be derived from hESCs and provides an in vivo system and molecular foundation to evaluate strategies for the generation of clinically transplantable HSC from hESC lines.

Animals↗
PubMed2005

Human embryonic stem cells maintained in the absence of mouse embryonic fibroblasts or conditioned media are capable of hematopoietic development.

To date, hematopoietic development of human embryonic stem cells (hESCs) has been limited to cell lines cultured in the presence of either mouse embryonic fibroblasts (MEFs) or MEF-conditioned media (MEF-CM). Anonymous xenogenic factors from MEFs or MEF-CM complicate studies of hESC self-renewal and also raise concerns for the potential clinical applications of generating primitive hematopoietic cells from hESC lines maintained under these ambiguous conditions. Here, we demonstrate that hESCs can be cultured over 30 passages in defined conditions in the absence of MEFs or MEF-CM using only serum replacement (SR) media and high concentrations of basic fibroblast growth factor (SR-bFGF). Similar to hESCs cultured in MEF-CM, hESCs cultured in SR-bFGF sustained characteristics of undifferentiated hESCs, proliferative potential, normal karyotype, in vitro and in vivo 3 germ-layer specification and gave rise to hemogenic-endothelial precursors required for subsequent primitive hematopoietic development. Our report demonstrates that anonymous factors produced by feeder cells are not necessary for hESC maintenance and subsequent hematopoietic specification, thereby providing a defined system for studies of hESC self-renewal and hESC-derived hematopoiesis.

Alkaline Phosphatase↗
PubMed2005

Hematopoietic development from human embryonic stem cell lines.

The most common human cell-based therapy applied today is hematopoietic stem cell (HSC) transplantation. Currently, human bone marrow, mobilized peripheral blood, and umbilical cord blood represent the major sources of transplantable HSCs, but their availability for use is limited by both compatibility between donor and recipient and required quantity. Although increasing evidence suggests that somatic HSCs can be expanded to meet current needs, their in vivo potential is concomitantly compromised after ex vivo culture. In contrast, human embryonic stem cells (hESC) possess indefinite proliferative capacity in vitro and have been shown to differentiate into the hematopoietic cell fate, giving rise to erythroid, myeloid, and lymphoid lineages using a variety of differentiation procedures. Human ESC-derived hematopoietic cells emerge from a subset of embryonic endothelium expressing PECAM-1, Flk-1, and VE-Cadherin, but lacking CD45 (CD45negPFV). These CD45negPFV precursors are exclusively responsible for hematopoietic potential of differentiated hESCs. hESC-derived hematopoietic cells show similar clonogenic capacity and primitive phenotype to somatic sources of hematopoietic progenitors and possess limited in vivo repopulating capacity in immunodeficient mice, suggestive of HSC function. Here, we will review current progress in studies of hESC-derived hematopoietic cells and discuss the potential precincts and applications.

Cell Culture Techniques↗
PubMed2005

Human embryonic stem cells: potential tool for achieving immunotolerance?

The derivation of human embryonic stem cells (hESCs), whose in vitro differentiation might be directed toward different cell types, has raised the hope for cell replacement therapies. Despite the emerging reports to differentiate hESCs into specific lineages and then to distinct mature cell subsets, there are still several issues that need to be resolved before transplantation of these cells can be realized. In this context, immune rejection by the host immune system has been considered to be one of the greatest hurdles for cellular transplantation. However, recent data support the concept that hESCs and/or their differentiated derivatives possess immune-privileged properties, suggesting that cells derived from hESC may provide a potential tool for induction of immunetolerance. Currently, our understanding of the tolerogenic potential of hESCs is limited to assessment by in vitro assays or xenogenic transplantation approaches in vivo. Human ESCs express low levels of major histocompatability complex (MHC)-I antigens and lack expression of MHC-II antigens and costimulatory molecules, and are not recognized by natural killer cells and inhibit T-cell induced-stimulation by third-party antigen-presenting cells. Upon injection into immunocompetent mice, hESCs are unable to induce an immune response as demonstrated by their inability to induce an inflammatory response. Based on these initial observations, further studies in hESCs immunobiology are warranted and may reveal unique mechanisms that account for the immunological properties of hESCs. Here, we explore the prospect of using hESCs and their derivatives for immunomodulation and tolerance induction.

Animals↗
PubMed2005

Genetic manipulation of human embryonic stem cells: a system to study early human development and potential therapeutic applications.

The successful derivation of human embryonic stem cell (hESC) lines by Thomson and colleagues [Thomson et al., 1998] provided a new area of investigation in both regenerative medicine and early human development. Fundamental study of the molecular and cellular mechanisms responsible for normal lineage development will rely on reproducible protocols to direct the differentiation of hESCs into specific lineages of interest and genetically manipulate both hESCs and their derivatives. Identifying standards for maintenance of hESCs, methods for controlled differentiation and genetic manipulation of hESCs and their derivatives will provide a foundation to explore their potential therapeutic use in cell and gene therapy. In the present review, our goal is to outline the latest advances in the field with particular focus on how hESCs and their derivatives can be genetically altered, how this may be useful in better understanding the cellular and molecular events of lineage differentiation, and how deregulation of these cellular processes may lead to abnormal development and disease.

Cell Differentiation↗
PubMed2005

[Study of the relative recovery of sinomenine microdialysis system and it's influential factor].

OBJECTIVE: (1) To study the effect of concentration and flow rate on relative recovery (RR); (2) To study the difference Of relative recovery between probes; (3) To study the relationship between relative recovery and relative loss (RL). METHODS: HPLC. RESULTS: (1) The sinomenine concentration has no obvious effect on RR in the same flow rate. (2) RR is reduced by exponent law as the flow rate increases. (3) There is significent difference between probes. CONCLUSION: The RR isn't affected by sinomenine concentration as the flow rate is same. The flow rate has notable effect on RR as the sinomenine concentration is same. The RR of every probe should be assayed. We can take RL as RR to do in-vivo study.

Chromatography, High Pressure Liquid↗
PubMed2004

Endothelial and hematopoietic cell fate of human embryonic stem cells originates from primitive endothelium with hemangioblastic properties.

The cellular organization and relationships among precursors that initiate embryonic angiogenesis and hematopoiesis in the human have yet to be characterized. Here, we identify a subpopulation of primitive endothelial-like cells derived from human embryonic stem cells (hESCs) that express PECAM-1, Flk-1, and VE-cadherin, but not CD45 (CD45negPFV cells), and that are uniquely responsible for endothelial and hematopoietic development. Molecular profiling of CD45negPFV cells is consistent with endothelial and hematopoietic competency. Clonal isolation demonstrates that the CD45negPFV population includes bipotent cells with endothelial and hematopoietic capacity. We suggest that human hematopoiesis and endothelial maturation originate exclusively from a subset of embryonic endothelium that possesses hemangioblastic properties and offers a model system to study these lineage relationships in the human.

Antigens, CD↗
PubMed2004

Retroviral transduction of hematopoietic cells differentiated from human embryonic stem cell-derived CD45(neg)PFV hemogenic precursors.

Human embryonic stem cells (hESCs) provide a unique opportunity to study molecular mechanisms that regulate specification of the hematopoietic lineage in the human. Exploitation of this model using transgenic strategies depends on the ability to target cells of the hematopoietic lineage effectively and establish stable transgene expression. Here, a recently defined subpopulation of endothelial-like precursors derived from hESCs that is exclusively responsible for hematopoietic cell fate (CD45(neg)PFV) is shown to express GALVR-1 receptor and be efficiently transduced with GALV-pseudotyped retrovirus. Retroviral transduction, measured by enhanced green fluorescent protein, of hESC-derived CD45(+) cells differentiated from isolated CD45(neg)PFV precursors was 26.5 +/- 13% with 5.6 +/- 4% of these cells coexpressing CD34. An average of 17.5% of clonogenic hematopoietic progenitors derived from CD45(neg)PFV precursors expressed the retroviral transgene. Addition of serum to cultures after retroviral exposure supported transgene expression in resulting hematopoietic cells derived from hemogenic CD45(neg)PFV precursors. Our study represents the first report to demonstrate that retroviral transduction systems, similar to those used currently in clinical gene therapy protocols, are capable of efficient transduction of hematopoietic progenitors derived from hESCs.

Animals↗
PubMed2004

Spectral properties of the association nanoparticle system of ciprofloxacin-phloxine and its application to fluorescence analysis.

There is a fluorescence peak at 570 nm, and a maximum absorption peak at 560 nm for phloxine (PHLO) in a pH 7 water solution. Under these conditions, the ciprofloxacin cation (CPFX+) and PHLO- combine into hydrophobic CPFX-PHLO association molecule by means of static gravitation. There are stronger van der Waals forces and hydrophobic forces among the CPFX-PHLO molecules. Thus, they aggregate automatically to the (CPFX-PHLO)n association nanoparticle in red-violet color. That was characterized by scan electron microscopy (SEM), hyperfiltration and dialysis tests. In 0.04 M HCl, the red-violet nanoparticles exhibited a Rayleigh scattering peak at 470 nm, a resonance scattering peak at 580 nm, a maximum absorption wavelength at 565 nm, and a fluorescence peak at 450 nm. The fluorescence analytical conditions of CPFX have been considered. The CPFX concentration in the range of 1.0 x 10(-6)-4.0 x 10(-5) M is linear to the fluorescence intensity, F450nm. The detection limit was achieved at 4.0 x 10(-7) M CPFX. The CPFX in real samples was determined with satisfactory results.

Microscopy, Electron, Scanning↗