Ex vivo expansion of functional human UCB-HSCs/HPCs by coculture with AFT024-hkirre cells.

Kiaa1867 (human Kirre, hKirre) has a critical role in brain development and/or maintenance of the glomerular slit diaphragm in kidneys. Murine homolog of this gene, mKirre expressed in OP9 and AFT024 cells could support hematopoietic stem cells/hematopoietic progenitor cells (HSC/HPC) expansion in vitro. HKirre is also expressed in human FBMOB-hTERT cell line and fetal liver fibroblast-like cells but its function has remained unclear.

Microgravity inhibits resting T cell immunity in an exposure time-dependent manner.

Background: Decline immune function is well documented after spaceflights. Microgravity is one of the key factors directly suppressing the function of immune system. Though T cell immune response was inhibited by microgravity, it is not clearly whether activation would be inhibited after a pre-exposure of microgravity on T lymphocytes at the resting state.

Microgravity inhibition of lipopolysaccharide-induced tumor necrosis factor-α expression in macrophage cells.

Objective And Design: Microgravity environments in space can cause major abnormalities in human physiology, including decreased immunity. The underlying mechanisms of microgravity-induced inflammatory defects in macrophages are unclear.

Material Or Subjects: RAW264.

MiR-17 partly promotes hematopoietic cell expansion through augmenting HIF-1α in osteoblasts.

Background: Hematopoietic stem cell (HSC) regulation is highly dependent on interactions with the marrow microenvironment, of which osteogenic cells play a crucial role. While evidence is accumulating for an important role of intrinsic miR-17 in regulating HSCs and HPCs, whether miR-17 signaling pathways are also necessary in the cell-extrinsic control of hematopoiesis hereto remains poorly understood.

Methodology/principal Findings: Using the immortalized clone with the characteristics of osteoblasts, FBMOB-hTERT, in vitro expansion, long-term culture initiating cell (LTC-IC) and non-obese diabetic/severe combined immunodeficient disease (NOD/SCID) mice repopulating cell (SRC) assay revealed that the ectopic expression of miR-17 partly promoted the ability of FBMOB-hTERT to support human cord blood (CB) CD34(+) cell expansion and maintain their multipotency.

Labeling of hematopoietic stem cells by Tat peptide conjugated quantum dots for cell tracking in mouse body.

Fluorescent quantum dots have great potential to act as labeling tools in biological research, especially cellular tracking and imaging. Tat peptide conjugated quantum dots were introduced into living human hematopoietic stem cells (HSCs). The internalized quantum dots were assessed by laser confocal microscope and flow cytometer.

Applications of fluorescent quantum dots to stem cell tracing in vivo.

Fluorescent quantum dots have great potential to act as labels in biological research, especially cellular tracking in vivo. Here, small thiol molecules-capped CdSe/ZnS quantum dots attached to Tat peptide were used for label agents, and introduced into living stem cells. The stem cells labeled with quantum dots were intravenously injected into the tail veins of NOD/SCID beta2M null mice, and whose tissue sections of major organs of null mice were examined with fluorescence microscope to assess the distribution of transplanted stem cells.

[Laser tweezers Raman spectroscopy analysis of liver cancer tissue].

Single cell laser tweezers Raman spectroscopy (LTRS) has been applied to biology field. In the present article, the authors measured the spectra of liver cancer cells, para-cancer cells and normal hepatocytes using single cell laser tweezer Raman spectroscopy (LTRS) system and compared their average spectra changes. The results showed that the laser tweezers Raman spectroscopy could differentiate specimens of different pathological changes from liver tissue studied.

Human leukocyte antigen-G1 inhibits natural killer cytotoxicity through blocking the activating signal transduction pathway and formation of activating immunologic synapse.

Nonclassical major histocompatibility complex (MHC) class I molecule human leukocyte antigen (HLA)-G is normally expressed on the placental cells, especially fetal endothelial cells and invasive cytotrophoblast cells at the maternal-fetal interface. This antigen meditates immune tolerance in pregnancy through interaction with immune cells including natural killer (NK) cells. In this study, we investigated the mechanisms underlying HLA-G1-mediated inhibition of NK cytotoxicity using HLA-G1-transfected K562 cells and NK92 cells.

Applications of mesenchymal stem cells labeled with Tat peptide conjugated quantum dots to cell tracking in mouse body.

Fluorescent quantum dots have great potential in cellular labeling and tracking. Here, PEG encapsulated CdSe/ZnS quantum dots have been conjugated with Tat peptide, and introduced into living mesenchymal stem cells. The Tat peptide conjugated quantum dots in mesenchymal stem cells were assessed by fluorescent microscopy, laser confocal microscope and.

NIR Raman spectroscopic investigation of single mitochondria trapped by optical tweezers.

Raman spectroscopy is a vibration spectroscopic technique that has been widely used to probe biochemical changes of biological sample such as tumor tissue, blood cells, bacteria and yeast. Here, we applied near-infrared Raman spectroscopy to analyze the chemical composition changes of intact or swollen mitochondria induced by calcium ions. We used a confocal Laser Tweezers Raman Spectroscopy (LTRS) system that combined optical trapping and near infrared Raman spectroscopy to confine a single mitochondrion and consequently measure its Raman spectra following the addition of calcium ion solution.

Gastric cancer cells in collagen gel matrix: three-dimensional growth and differential expression of adhesion molecules (CD44s, CD54, E-cadherin).

To characterize the growth of human gastric cancer cells in collagen gel matrix and adhesive status of the cells in comparison with conventional monolayer cells. Three kinds of human gastric cancer cell lines (BGC823, SGC7901, and MKN28) were cultured alone or co-cultured with normal human fibroblasts in collagen gel matrix, and their cell cycle, metabolic function, and the expression of adhesive molecules (CD44s, CD54, and E-cadherin) were analyzed by flow cytometry or other methods. Two of three cell lines (BGC823 and SGC7901) and their co-cultures showed multilayer growth in collagen gel matrix, and their growth and metabolism rate became slow and the cell adhesion molecules (CAMs) expression was down regulated.

Establishment and characterization of a human telomerase catalytic subunit-transduced fetal bone marrow-derived osteoblastic cell line.

The fate of human hematopoietic stem cells (HSCs)/progenitor cells (HPCs) is influenced by bone marrow (BM) stromal cells. To investigate the role of stromal cells in the hematopoietic support, we have transduced human fetal BM stromal cells (FBMSCs) with a human telomerase catalytic subunit (hTERT). One of the resultant cell lines was identified as osteoblasts, because it contained mineral deposits and constitutively expressed osteogenic genes osteocalcin, osteopontin, collagen type I, osteoblast marker alkaline phosphatase, but not marrow stromal cell marker STRO-1 and CD105.

[Three-dimensional spheroid model for cultivating WB-F344 cells in simulated microgravity].

Three-dimensional (3D) culture of cells could closely mimic the in vivo situation with regard to cell function and microenvironment compared with plane monolayer cultured cells. In this paper, we established 3D culture of rat WB-F344 cells with rotary cell culture system (RCCS) to simulate microgravity environment, and examined cells proliferation, morphology, microstructure, E-cadherin protein quantity and mRNA expression of adhesion molecules by count the number of cells, optical microscope, transmission electron microscope and reverse transcriptase-polymerase chain reaction (RT-PCR). The results demonstrated that cells were polyhedron with lots of micovilli and mitochondria, which grow well and packed together densely to form irregular aggregates.

Rapid production of human KIR2DL4 extracellular domain and verification of its interaction with HLA-G.

Killer cell immunoglobulin-like receptor (KIR) 2DL4 is the only KIR member reported to be expressed by all human natural killer (NK) cells. It differs from other KIR members in both structure and function. Its specific interaction with HLA-G, a non-classical MHC class I molecule, has been suggested to play an important role in regulating NK cell-mediated cytotoxicity.

Improved performance of primary rat hepatocytes on blended natural polymers.

Alginate (Alg), chitosan (Chi), collagen (Col), gelatin (Gel), and the mixtures of every two of them were screened to determine their suitability for hepatocyte culture. The test materials were fabricated as films and then evaluated on the basis of their abilities to promote the attachment and functions of rat hepatocytes cultured on them. Cellular attachment on Col and Gel was favorable.

The existence of epithelial-to-mesenchymal cells with the ability to support hematopoiesis in human fetal liver.

The fetal liver is the major hematopoietic organ during mid-gestation, and it is also a source of stem cells that exist in a complex environment. In this study, we isolated a population of actively replicating cells with the characteristic of the epithelial-to-mesenchymal transition (EMT) from fetal liver. These cells were identified with the epithelial markers, including alpha-fetoprotein (AFP), albumin (ALB), cytokeratins (CK) 7, and CK18, as well as the mesenchymal markers, such as alpha-smooth muscle actin (ASMA), CD29, CD44, CD49, CD54, collagen I and osteopontin (OPN).

Chitosan/gelatin composite microcarrier for hepatocyte culture.

Solid and porous chitosan/gelatin (CG) composite microcarriers were prepared by a water-in-oil emulsion process with additional freezing and lyophilization. Adult rat hepatocytes (10(6) cells ml(-1)) attached on CG microcarriers maintained at least 15 d of viability and differentiated functions. Over 15 d, unimmobilized hepatocytes released 1.

[Major role of stromal cell derived factor and its receptor CXCR4 in the mobilization and homing of hematopoietic stem/progenitor cells - review].

Stromal cell derived factor (SDF), expressing on bone marrow stromal cells is a CXC-type chemokine, which specifically chemoattracts hematopoietic stem cells (HSCs) expressing CXCR4. SDF plays important roles in homing and mobilizing of HSCs. In this paper the regulatory mechanism of SDF/CXCR4 in the HSC migration process is mainly reviewed.