Biomedical subjects

Yuehua Jiang

Publications and source records attributed to Yuehua Jiang.

15 recordsLinked to original sources

PubMed2007

Hematopoietic reconstitution by multipotent adult progenitor cells: precursors to long-term hematopoietic stem cells.

For decades, in vitro expansion of transplantable hematopoietic stem cells (HSCs) has been an elusive goal. Here, we demonstrate that multipotent adult progenitor cells (MAPCs), isolated from green fluorescent protein (GFP)-transgenic mice and expanded in vitro for >40-80 population doublings, are capable of multilineage hematopoietic engraftment of immunodeficient mice. Among MAPC-derived GFP+CD45.2+ cells in the bone marrow of engrafted mice, HSCs were present that could radioprotect and reconstitute multilineage hematopoiesis in secondary and tertiary recipients, as well as myeloid and lymphoid hematopoietic progenitor subsets and functional GFP+ MAPC-derived lymphocytes that were functional. Although hematopoietic contribution by MAPCs was comparable to control KTLS HSCs, approximately 10(3)-fold more MAPCs were required for efficient engraftment. Because GFP+ host-derived CD45.1+ cells were not observed, fusion is not likely to account for the generation of HSCs by MAPCs.

Animals↗

PubMed2006

Isolation and characterization of kidney-derived stem cells.

Acute kidney injury is followed by regeneration of damaged renal tubular epithelial cells. The purpose of this study was to test the hypothesis that renal stem cells exist in the adult kidney and participate in the repair process. A unique population of cells that behave in a manner that is consistent with a renal stem cell were isolated from rat kidneys and were termed multipotent renal progenitor cells (MRPC). Features of these cells include spindle-shaped morphology; self-renewal for >200 population doublings without evidence for senescence; normal karyotype and DNA analysis; and expression of vimentin, CD90 (thy1.1), Pax-2, and Oct4 but not cytokeratin, MHC class I or II, or other markers of more differentiated cells. MRPC exhibit plasticity that is demonstrated by the ability of the cells to be induced to express endothelial, hepatocyte, and neural markers by reverse transcriptase-PCR and immunohistochemistry. The cells can differentiate into renal tubules when injected under the capsule of an uninjured kidney or intra-arterially after renal ischemia-reperfusion injury. Oct4 expression was seen in some tubular cells in the adult kidney, suggesting these cells may be candidate renal stem cells. It is proposed that MRPC participate in the regenerative response of the kidney to acute injury.

Animals↗

PubMed2006

Sequential exposure to cytokines reflecting embryogenesis: the key for in vitro differentiation of adult bone marrow stem cells into functional hepatocyte-like cells.

Differentiation of adult bone marrow stem cells (BMSC) into hepatocyte-like cells is commonly performed by continuous exposure to a cytokines-cocktail. Here, it is shown that the differentiation efficacy in vitro can be considerably enhanced by sequential addition of liver-specific factors (fibroblast growth factor-4, hepatocyte growth factor, insulin-transferrin-sodium selenite, and dexamethasone) in a time-dependent order that closely resembles the secretion pattern during in vivo liver embryogenesis. Quantitative RT-PCR analysis and immunocytochemistry showed that, upon sequential exposure to liver-specific factors, different stages of hepatocyte differentiation, as seen during liver embryogenesis, can be mimicked. Indeed, expression of the early hepatocyte markers alpha-fetoprotein and hepatocyte nuclear factor (HNF)3beta decreased as differentiation progressed, whereas levels of the late liver-specific markers albumin (ALB), cytokeratin (CK)18, and HNF1alpha were gradually upregulated. In contrast, cocktail treatment did not significantly alter the expression pattern of the hepatic markers. Moreover, sequentially exposed cells featured highly differentiated hepatic functions, including ALB secretion, glycogen storage, urea production, and inducible cytochrome P450-dependent activity, far more efficiently compared to the cocktail condition. In conclusion, sequential induction of the differentiation process, analogous to in vivo liver development, is crucial for in vitro differentiation of adult rat BMSC into functional hepatocyte-like cells. This model may not only be applicable for in vitro studies of endoderm differentiation but it also provides a "virtually unlimited" source of functional hepatocytes, suitable for preclinical pharmacological research and testing, and cell and organ development.

Animals↗

PubMed2006

Multipotent adult progenitor cell isolation and culture procedures.

We describe methods for isolation of multipotent adult progenitor cells (MAPCs) from newborn to 6-week-old mice and rats. The maintenance of these cells, including their culture, media formulas, and quality control procedures, are also explained. Additionally, ways to identify MAPCs including their phenotype and morphology are discussed.

Animals↗

PubMed2005

Thymidine analogs are transferred from prelabeled donor to host cells in the central nervous system after transplantation: a word of caution.

Thymidine analogs, including bromodeoxyuridine, chlorodeoxyuridine, iododeoxyuridine, and tritiated thymidine, label dividing cells by incorporating into DNA during S phase of cell division and are widely employed to identify cells transplanted into the central nervous system. However, the potential for transfer of thymidine analogs from grafted cells to dividing host cells has not been thoroughly tested. We here demonstrate that graft-derived thymidine analogs can become incorporated into host neural precursors and glia. Large numbers of labeled neurons and glia were found 3-12 weeks after transplantation of thymidine analog-labeled live stem cells, suggesting differentiation of grafted cells. Remarkably, however, similar results were obtained after transplantation of dead cells or labeled fibroblasts. Our findings reveal for the first time that thymidine analog labeling may not be a reliable means of identifying transplanted cells, particularly in highly proliferative environments such as the developing, neurogenic, or injured brain.

Animals↗

PubMed2005

Transmembrane voltage induced on a cell membrane in suspensions exposed to an alternating field: a theoretical analysis.

We present analytical equations for the transmembrane voltage (DeltaPsi) induced by an alternating field on spherical cells arranged in orderly suspensions. For physiologically normal cells, the cell membrane was assumed to be non-conductive. With increasing alternating field frequency, capacitive property of the cytoplasm and the external medium become increasingly important and thus must be accounted for. Considering the symmetry of the arrayed cells and the tiny volume of the unit cell compared to that of the suspensions, the influence exerted on a unit cell by other cells was posited to be approximately symmetrical with respect to the symmetrical axis. This implies that the shape of the equipotential plane of spherical cells in the suspensions is similar to that of the single cell exposed to the external field, though the value of the potential of both cells should be different. Therefore, the internal field of the cytoplasm and the equivalent body of a unit cell in the suspensions should be approximately constant. This allows for calculating the effective average field in the equivalent body with Maxwell-Wagner and Bruggeman-Hanai equations for low and high cell concentrations, respectively. We investigated the conditions, under which the local electric field of a unit cells in suspension is approximately equal to that of a single cell. Under these conditions the analytical solution for DeltaPsi induced by alternating fields on cells in suspensions can be derived from that of the single cell.

Cell Membrane↗

PubMed2005

Real-time in vivo imaging of stem cells following transgenesis by transposition.

Previous studies have identified Sleeping Beauty transposons as efficient vectors for nonviral gene delivery in mammalian cells. However, studies demonstrating the usefulness of transposons as gene delivery vehicles into adult stem cells are lacking. Multipotent adult progenitor cells (MAPC) are nonhematopoietic stem cells with the capacity to form most, if not all, cell types of the body and as such hold great therapeutic potential. The whole-body biodistribution and persistence of MAPC are unknown, and such data would help direct clinical applications. We have nucleofected murine MAPC with two plasmid-based Sleeping Beauty transposons encoding the red fluorescent protein (DsRed2) and firefly luciferase. Transgenic euploid MAPC clones maintained their characteristic multilineage differentiation potential in vitro. DsRed2 and luciferase expression allowed for MAPC detection in vivo and in tissue sections. To confirm that transgenesis occurred by transposition into the genome of MAPC, we mapped Sleeping Beauty transposon integration sites in two MAPC clones using splinkerette PCR. This novel dual-reporter imaging approach based on the transgenesis of MAPC with Sleeping Beauty transposons sheds light on the homing patterns of MAPC and paves the way for quantification of MAPC engraftment in real time in vivo.

Animals↗

PubMed2003

Neuroectodermal differentiation from mouse multipotent adult progenitor cells.

We recently showed that a rare cell from murine bone marrow, which we termed multipotent adult progenitor cells (MAPCs), can be expanded for >120 population doublings. Mouse (m)MAPCs differentiate into mesenchymal lineage cells as well as endothelium and endoderm, and, when injected in the blastocyst, mMAPCs contribute to most if not all somatic cell lineages including the different cell types of the brain. Our results, reported herein, demonstrate that mMAPCs can also be induced to differentiate into cells having anatomical and electrophysiological characteristics similar to those of midbrain neurons. Differentiation to a neuronal phenotype was achieved by coculturing mMAPCs with astrocytes, suggesting that neuronal differentiation may require astrocyte-derived factors similar to what is required for the differentiation of embryonic stem cells and neural stem cells to neurons. Differentiation of mMAPCs to neuron-like cells follows similar developmental steps as described for embryonic stem cells and neural stem cells. MAPCs therefore may constitute a source of cells for treatment of central nervous system disorders.

Animals↗

PubMed2003

Neural differentiation and incorporation of bone marrow-derived multipotent adult progenitor cells after single cell transplantation into blastocyst stage mouse embryos.

Previously we reported the characterization of multipotent adult progenitor cells (MAPCs) isolated from the bone marrow of rodents. In that study, single murine MAPCs derived from ROSA-26, beta-galactosidase (beta-Gal)-positive transgenic mice were injected into E3.5 C57/B16 mouse blastocysts. The resultant chimeric blastocysts were then implanted into pseudopregnant females and were allowed to develop naturally through birth and into adulthood. Chimeric mice were sacrificed 6 to 20 weeks after birth, and were processed for histological analysis. Beta-galactosidase activity was identified in all organs and tissues examined, and tissue-specific differentiation and engraftment was confirmed by colabeling with antibodies that recognize beta-Gal and tissue-specific markers. In the present study we have examined neural engraftment derived from the clonal expansion of a single MAPC during rodent development, and characterized the neural phenotype of MAPCs in the resultant chimeric animals. Donor cell-derived beta-Gal activity was evident throughout the brain. Double and triple immunofluorescent labeling studies revealed MAPC-derived neurons (NeuN/beta-Gal) and astrocytes (GFAP/beta-Gal) in the cortex, striatum, medial septal nucleus, hippocampus, cerebellum, substantia nigra, and thalamus. More specifically, donor-derived neurons contributed to each of the cellular layers of the cortex; the pyramidal and granule cell layers, as well as the hilus, of the hippocampus; Purkinje and granule cell layers in the cerebellum; and GABAergic cells in the caudate and putamen. This study characterizes the potential for MAPCs to differentiate into specific neuronal and glial phenotypes, and to integrate normally during development, after implantation into blastocysts, and provides additional evidence that MAPCs exhibit properties similar to embryonic stem cells.

Animals↗

PubMed2002

[Association analysis of childhood absence epilepsy by microsatellite DNA].

OBJECTIVE: To investigate whether or not the gamma-aminobutyric acid GABA receptor subtype Alpha genes GABRA5 and GABRB3 are associated with childhood absence epilepsy CAE . METHODS: Five microsatellite DNA 69CA 85CA 155CA1 155CA2 and A55CA1 adjacent to chromosome 15q11-15q13 were used as genetic markers. Fluorescence-based semi-automated genotyping technique was used in 90 CAE patients and 100 normal controls to conduct genotyping. Case-control study was used to do association analysis. RESULTS: In Chinese normal population the allele frequencies of the five microsatellite DNAs were in good agreement with Hardy- Weinberg equilibrium. The polymorphism information content PIC of the five microsatellite DNA were 0.47 0.82 0.66 0.86, and 0.86 respectively. The frequencies of some alleles of the 5 microsatellite DNAs in CAE patients were significantly higher than those in normal controls. CONCLUSION: Four of the five microsatellite DNAs are good genetic markers. GABA subtype Alpha genes GABRA5 and GABRB3 may be associated with the pathogenic mechanism of CAE.

Adolescent↗

PubMed2002

Pluripotency of mesenchymal stem cells derived from adult marrow.

We report here that cells co-purifying with mesenchymal stem cells--termed here multipotent adult progenitor cells or MAPCs--differentiate, at the single cell level, not only into mesenchymal cells, but also cells with visceral mesoderm, neuroectoderm and endoderm characteristics in vitro. When injected into an early blastocyst, single MAPCs contribute to most, if not all, somatic cell types. On transplantation into a non-irradiated host, MAPCs engraft and differentiate to the haematopoietic lineage, in addition to the epithelium of liver, lung and gut. Engraftment in the haematopoietic system as well as the gastrointestinal tract is increased when MAPCs are transplanted in a minimally irradiated host. As MAPCs proliferate extensively without obvious senescence or loss of differentiation potential, they may be an ideal cell source for therapy of inherited or degenerative diseases.

Aging↗

PubMed2002

Multipotent progenitor cells can be isolated from postnatal murine bone marrow, muscle, and brain.

OBJECTIVE: Recent studies have shown that cells from bone marrow (BM), muscle, and brain may have greater plasticity than previously known. We have identified multipotent adult progenitor cells (MAPC) in postnatal human and rodent BM that copurify with mesenchymal stem cells (MSC). BM MAPC proliferate without senescence and differentiate into mesodermal, neuroectodermal, and endodermal cell types. We hypothesized that cells with characteristics similar to BM MAPC can be selected and cultured from tissues other than BM. MATERIALS AND METHODS: BM, whole brain, and whole muscle tissue was obtained from mice. Cells were plated on Dulbecco modified Eagle medium supplemented with 2% fetal calf serum and 10 ng/mL epidermal growth factor (EGF), 10 ng/mL platelet-derived growth factor (PDGF-BB), and 1000 units/mL leukemia inhibitory factor (LIF) for more than 6 months. Cells were maintained between 0.5 and 1.5 x 10(3) cells/cm(2). At variable time points, we tested cell phenotype by FACS and evaluated their differentiation into endothelial cells, neuroectodermal cells, and endodermal cells in vitro. We also compared the expressed gene profile in BM, muscle, and brain MAPC by Affimetrix gene array analysis. RESULTS: Cells could be cultured from BM, muscle, and brain that proliferated for more than 70 population doublings (PDs) and were negative for CD44, CD45, major histocompatibility complex class I and II, and c-kit. Cells from the three tissues differentiated to cells with morphologic and phenotypic characteristics of endothelium, neurons, glia, and hepatocytes. The expressed gene profile of cells derived from the three tissues was identical (r(2) > 0.975). CONCLUSIONS: This study shows that cells with MAPC characteristics can be isolated not only from BM, but also from brain and muscle tissue. Whether MAPC originally derived from BM are circulating or all organs contain stem cells with MAPC characteristics currently is being studied. Presence of MAPC in multiple tissues may help explain the "plasticity" found in multiple adult tissues.

Animals↗

PubMed2002

Multipotent adult progenitor cells from bone marrow differentiate into functional hepatocyte-like cells.

We have derived from normal human, mouse, and rat postnatal bone marrow primitive, multipotent adult progenitor cells (MAPCs) that can differentiate into most mesodermal cells and neuroectodermal cells in vitro and into all embryonic lineages in vivo. Here, we show that MAPCs can also differentiate into hepatocyte-like cells in vitro. Human, mouse, and rat MAPCs, cultured on Matrigel with FGF-4 and HGF, differentiated into epithelioid cells that expressed hepatocyte nuclear factor-3beta (HNF-3beta), GATA4, cytokeratin 19 (CK19), transthyretin, and alpha-fetoprotein by day 7, and expressed CK18, HNF-4, and HNF-1alpha on days 14-28. Virtually all human, as well as a majority of rodent cells stained positive for albumin and CK18 on day 21; 5% (rodent) to 25% (human) cells were binucleated by day 21. These cells also acquired functional characteristics of hepatocytes: they secreted urea and albumin, had phenobarbital-inducible cytochrome p450, could take up LDL, and stored glycogen. MAPCs, which can be expanded in vitro and maintained in an undifferentiated state for more than 100 population doublings, can thus differentiate into cells with morphological, phenotypic, and functional characteristics of hepatocytes. MAPCs may therefore be an ideal cell for in vivo therapies for liver disorders or for use in bioartificial liver devices.

Adult↗

PubMed2002

[Low-penetrance retinoblastoma due to exons 24 and 25 deletions in the Rb1 gene].

OBJECTIVE: Identification of Rb1 mutations permits accurate genetic counseling. Characterization of the causative mutation in a large low penetrance family is likely to provide important information for tumorigenesis of retinoblastoma(RB). METHODS: Quantitative fluorescent multiplex PCR QFM-PCR technique was used for mutation detection. Long fragment PCR, reverse transcriptase-PCR, subcloning, direct sequencing and Western blotting techniques were used for characterizing the mutation. RESULTS: A deletion covering exons 24 and 25 of Rb gene was found in a large family with 122 members in four generations. Of the 18 carries in the family, only 11 were delivered to either unilateral or bilateral RB. The family has much low-penetrance retinoblastoma, compared with the usual, high-penetrance RB (95%). An extent of 4 kb fragment deletion was detected in genomic deletion of the mutation. cDNA and sequence data showed a 174 bp shorter than the wild type message RNA resulting in an in-frame loss of 58 residues. Further analysis demonstrated the truncated protein expression of 6000 Da shorter than wild type RB1 protein. CONCLUSION: QFM-PCR technique has enabled the investigators to identify a large deletion covering entire exons 24 and 25 of the Rb1 gene. It is the largest deletion ever found in low penetrance RB families. The characterizations of the mutation in genomic DNA, RNA and protein have provided new evidences which enhance credence to the idea that low penetrance retinoblastoma is caused by only partially functional disable of Rb1. The data will be useful in genetic counseling, particularly significant for the unaffected carriers in RB low penetrance families.

Exons↗

PubMed2002

[Examining consecutively serum leptin levels in normal pregnant and pregnancy-induced hypertension women].

OBJECTIVE: To detect successsively serum leptin levels in normal, pregnancy-induced hypertension (PIH) pregnant women. METHODS: Levels of serum leptin were measured in the 16-20, 24-28, 32-36 weeks of gestation, at the delivery time in 50 healthy, 14 PIH pregnant women and their newborns and in 40 healthy non-pregnant women by Immuno-radioassay method. Serum leptin levels were correlated with body weight, body mass index (BMI), blood pressure and placental weight. RESULTS: (1) The serum leptin levels were increased gradually during the normal (14.1 +/- 2.2)-(25.4 +/- 2.7) micro g/L and the PIH pregnancy [(13.4 +/- 3.0)-(21.4 +/- 3.7)] micro g/L, especially in the PIH women. It was found that leptin concentrations rose markedly from 28 to 36 weeks of gestation, but increased slightly before the 28 weeks of gestation and after the 36 weeks of gestation in normals, and in contrast to the normal pregnancy, consistently higher until to the delivery time in the PIH. (2) The positive correlations were significant between the levels of serum leptin with their body weight and BMI in the normal pregnant and non-pregnant women (r = 0.478-0.639, P < 0.05 or P < 0.01), but not significant in the PIH pregnant (r = 0.035-0.379, P > 0.05). (3) The positive correlations were significant between the serum leptin concentrations and the systolic blood pressure, diastolic blood pressure and mean artery pressure in the PIH women after 20 weeks of gestation (r = 0.639-0.852, P < 0.05), but not significant in the normal pregnant, the PIH before 20 weeks of gestation and the non-pregnant women (r = 0.113-0.498, P > 0.05). (4) Before the delivery time, the positive correlation between the serum leptin concentrations of the pregnant women and that of the newborns was not significant, and also not significant between the puerperas' serum leptin levels and the placental weight in the normal pregnant (r = 0.132, 0.097, P > 0.05). But it was interesting that significant positive correlation was found between the puerperas' serum leptin concentrations and the cord serum leptin levels (r = 0.792, P < 0.01) and significant negative correlation was detected between the puerperas' serum leptin levels and the placental weight in the PIH women (r = -0.819, P < 0.01). (5) The leptin levels of cord blood were positively correlated with the body weight and BMI of newborns in both of the normal and PIH pregnancy (r = 0.520-0.655, P < 0.05 or P < 0.01). CONCLUSION: The characteristic change of serum leptin levels and correlations between the serum leptin concentrations and the related pregnant signs was different in normal and PIH pregnancy.

Blood Pressure↗