Ling-song Li

Peking University Third Hospital, Peping, Beijing, China

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Publications (9)5.85 Total impact

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    ABSTRACT: To investigate the survival, migration and differentiation of the cultured human mesenchymal stem cells derived from bone marrow (hMSCs) after transplanted onto the alkaline burn rabbit cornea. Alkaline burn on rabbit corneas was induced with NaOH solution. One month later, hMSCs cultured with a feeding of amniotic membrane were transplanted onto the surface of alkaline burn rabbit corneas. Amniotic membrane alone transplantation was used at the same time as control group. One month after transplantation, the changes of corneal morphology were analyzed by clinical observations and HE staining. Immunohistochemistry was carried out with the antibodies against human nuclei and cytokeratin 12 to investigate the distribution and differentiation of hMSCs. The rabbit cornea became totally opaque one month after alkaline burn. Blood vessels could be seen within the superficial layer and stroma. The surface of cornea was rough and dry. There were many goblet cells found in the corneal epithelial layer. One month after transplantation of hMSCs, the surface of alkaline burn cornea became smoother. The amount of the new blood vessels of the cornea reduced and the goblet cells disappeared. Anti-human nuclei antibody staining showed positive cells on the surface layer and superficial stroma while cytokeratin 12 positive cells were only present in the epithelium layer. In the amniotic membrane transplantation control group, no clinical improvement of the cornea was found. Goblet cells were still seen on the corneal surface. Both anti-human nuclei antibody and cytokeratin 12 staining were negative. hMSCs survive and migrate to stroma after transplanted onto the surface of alkaline burn rabbit cornea. No rejection is detected. hMSCs on the corneal surface differentiate to corneal epithelium, where those migrated to the stroma differentiate to cells other than epithelium. hMSCs transplantation decrease corneal conjunctivization after alkaline burn.
    [Zhonghua yan ke za zhi] Chinese journal of ophthalmology 04/2006; 42(3):246-50.
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    ABSTRACT: To verify the hypothesis that selected nestin positive cells derived from human fetal pancreas (according as medical ethnics) have surface markers similar to bone marrow mesenchymal stem cells (MSCs), and that these cells have multilineage potential. The cell surface markers were determined by flow cytometry, and then the potential that these cells might be differentiated into adipocytes and osteoplasts were explored. These cells have similar surface markers as MSCs of bone marrow origin. These cells was induced to differentiate into adipocytes and osteoplasts. Selected nestin positive cells derived from human fetal pancreas have certain characteristics of MSCs.
    Zhongguo yi xue ke xue yuan xue bao. Acta Academiae Medicinae Sinicae 01/2006; 27(6):683-7.
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    ABSTRACT: To examine the expression of nestin and neurogenin 3 (Ngn3), the markers of pancreatic stem cells, in the human fetal pancreas. The human fetal pancreas tissue of 12 and 14 weeks were examined for the expression of nestin and Ngn3 using the techniques of immunofluorescence dye and RT-PCR. Both nestin and Ngn3 expressed widely in 12 and 14 weeks before in human fetal pancreatic tissue. In these positive cells there was no co-expressing insulin or glucagon. There were nestin and Ngn3 co-expressing cells in ducts but not in the islets. The results of RT-PCR also indicated the expression of nestin and Ngn3. There was no expression of the markers of mature endocrine cells in the nestin and Ngn3 positive cells, and they were the marks of no-differentiation cells in the human fetal pancreatic tissue.
    Zhonghua wai ke za zhi [Chinese journal of surgery] 01/2006; 43(23):1537-40.
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    ABSTRACT: The side population (SP) phenotype might represent a common molecular feature for a wide variety of stem cells. The aim of this study was to investigate whether monoclonal SP progenitor cells were established from human fetal pancreas. Islet-like cell clusters (ICCs) were isolated from human fetal pancreas. Monolayer epithelium-like cells were obtained from the ICCs and passaged thereafter. Single SP or non-SP cells were sorted from these cells at the sixth passage. The rate of clone formation was about 2.7% for the SP cells, whereas there was no clone formation for the non-SP cells. The SP cell clones were further expanded for more than 15 passages and induced for differentiation into cells with characteristics of pancreatic beta-cells. We show for the first time that the monoclonal SP progenitors are established from human fetal pancreas. Therefore, this study may offer a novel method to purify pancreatic progenitor cells from human tissues.
    Biochemical and Biophysical Research Communications 08/2005; 333(2):603-8. · 2.41 Impact Factor
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    ABSTRACT: To isolate nestin-positive progenitor cells from human fetal pancreas and to detect their surface markers and their capability of proliferation and differentiation into pancreatic islet endocrine cells in vitro. Islet-like cell clusters (ICCs) were isolated from human fetal pancreas by using collagenase digestion. The free-floating ICCs were handpicked and cultured in a new dish. After the ICCs developed into monolayer epithelium-like cells, they were passaged and induced for differentiation. Reverse transcription polymerase chain reaction (RT-PCR), immunofluorescence stain, fluorescence-activated cell sorting (FACS) and radioimmunoassay (RIA) were used to detect the expression of cell markers. (1) The monolayer epithelium-like cells had highly proliferative potential and could be passaged more than 16 times in vitro; (2) RT-PCR analysis and immunofluorescence stain showed that these cells expressed both nestin and ABCG2, two of stem cell markers; (3) FACS analysis revealed that CD44, CD90 and CD147 were positive, whereas CD34, CD38, CD45, CD71, CD117, CD133 and HLA-DR were negative on the nestin-positive cells; (4) RT-PCR analysis showed that the mRNA expression of insulin, glucagon and pancreatic-duodenal homeobox gene-1 was detected, whereas the expression of nestin and neurogenin 3 disappeared in these cells treated with serum-free media supplemented with the cocktail of growth factors. Furthermore, the intra-cellular insulin content was detected by RIA after the induction culture. Nestin-positive cells isolated from human fetal pancreas possess the characteristics of pancreatic progenitor cells since they have highly proliferative potential and the capability of differentiation into insulin-producing cells in vitro. Interestingly, the nestin-positive pancreatic progenitor cells share many phenotypic markers with mesenchymal stem cells derived from bone marrow.
    World Journal of Gastroenterology 06/2005; 11(19):2906-11. · 2.55 Impact Factor
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    ABSTRACT: Mutations in PAX6 gene have been shown to be the genetic cause of aniridia, which is a severe panocular eye disease characterised by iris hypoplasia. However, there is no study to do genetic analysis of aniridia, although there are several case reports in China. Here, we describe a mutation analysis of PAX6 in a large Chinese family with aniridia. Genomic DNA from venous blood samples was prepared. Haplotype analysis was performed with two genetic markers (D11S904 and D11S935). Fourteen exons of the PAX6 gene were amplified from genomic DNA. Polymerase chain reaction (PCR) products of each exon were analysed by single strand conformational polymorphism (SSCP). The PCR products having an abnormal pattern were sequenced to confirm the mutation. Significant evidence for allele sharing in affected patients was detected suggesting that PAX6 mutation links to aniridia in this family. An extra band corresponding to exon 9 in PAX6 was found by single strand conformational polymorphism analysis in all the aniridia patients in this family, but not detected in the unaffected members. A mutation of C to T was detected by sequencing at the nucleotide 1080 that converts the Arg codon (CGA) to the termination codon (TGA). Aniridia is caused by a nonsense mutation of PAX6 gene in the large Chinese kindred. Genetic test is important to prevent the transmission of aniridia to their offsprings in the kindred by prenatal diagnosis.
    Chinese medical journal 03/2005; 118(4):302-6. · 0.90 Impact Factor
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    ABSTRACT: To investigate the association between PAX6 mutation and brain abnormalities. The brain structures of 18 affected patients and 6 normal controls in a large pedigree with a PAX6 mutation (c1080C-->T)were scanned with MRI assessing. Most of the affected patients showed brain abnormalities such as corpus callosum degeneration, broad cerebral ventricle grooves and broad olfactory grooves. Genetic defect of PAX6 gene may result in brain abnormalities.
    Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences 02/2005; 37(1):48-50.
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    ABSTRACT: To investigate the association of cytochrome p450 gene (CYP1A1)MSP1 polymorphisms with preterm delivery. Between July 1999 and June 2001, we conducted a case-control study using infant-parent triads including 247 families with full-term infants and 249 families with preterm delivery infants in Anqing, China. We extracted DNA from umbilical cord blood of the infants and vein blood of their parents,and performed PCR followed by restriction enzyme MspI digestion for genotyping the CYP1A1 gene MSP1 polymorphism. We used log-linear modeling to analyze the association of CYP1A1 gene polymorphism with the risk of preterm delivery. CYP1A1 gene C/C6235 increased the risk of preterm delivery both in infants (RR=1.80, 95% CI=1.02-3.18) and in their mothers (RR=1.82, 95% CI=1.11-2.98) significantly. There was no interaction between mothers' and children's CYP1A1 MSP1 genotypes. The variant alleles of CYP1A1 MSP1 of control triads accorded with Mendelian transmissions. Both infant and maternal CYP1A1 C/C6235 genotype both can increase the risk of preterm delivery in our study population, which suggests a possible role of human cytochrome P450 variability in the etiology of preterm delivery.
    Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences 01/2005; 36(6):595-9.
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    ABSTRACT: To determine transferrin receptor (TfR) expression of human mesenchymal stem cells (MSCs) in vitro and after transplantation in rabbit spinal cord,and to detect implanted MSCs by in vitro autoradiography. Human mesenchymal stem cells (hMSCs) were isolated from fetal blood. Flow cytometry assay, immuno-fluorescent staining and receptor binding assay were used to determine TfR expression of hMSCs. Radioiodinated transferrin saturated with iron [(125)I-Tf(Fe)(2)] was used as tracer. The hMSCs transplanted in rabbit spinal cord was tracked by in vitro autoradiography. Diffusion of (125)I-Tf(Fe)(2) in spinal cord was examined with autoradiography. TfR expression of MSCs was demonstrated by flow cytometry assay, immuno-fluorescent staining and receptor binding assay in vitro. (125)I-Tf(Fe)(2) bound to hMSCs with a equilibrium dissociation constant (KD) of (0.98+/-0.12) nmol/L and a maximal density of binding sites (B(max)) of (107 702+/-6 226) sites per cell. Immuno-fluorescent staining showed that TfRs were expressed on hMSCs on the 2nd day but not be expressed on the 10th day post transplantation. Autoradiography showed distinct accumulation of (125)I-Tf(Fe)(2) but not (125)I-HSA at hMSCs implantation sites of spinal cord sections on the 2nd day post transplantation. (125)I-Tf(Fe)(2) had diffused into spinal cord 16 hours after incubation. Implanted hMSCs could be detected by in vitro autoradiography with (125)I-Tf(Fe)(2) on the 2nd day after being transplanted in spinal cord. To track implanted hMSCs with radionuclide imaging techniques in vivo, TfR was a suitable target for imaging and radioiodinated Tf(Fe)(2) was a feasible tracer.
    Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences 07/2004; 36(3):276-80.