[Dynamics of Proliferation and Differentiation after Transplantation of Hematopoietic Cells in Mouse].

OBJECTIVE: To observe the dynamic changes of hematopoietic reconstitution and multiple lineages differentiation at early phase after transplantation. METHODS: Whole bone marrow mononuclear cells (wBMMNC, 5×106) and enriched c-Kit+ hematopoietic stem/progenitor cells (HSPC, 3×105) from the BM of B6-Ly5.1 mice were transplanted into lethally irradiated B6-Ly5.2 mice, the frequencies and absolute numbers of donor-derived cells (including LKS- and LKS+) were detected by flow cytometry. The multiple lineages differentiation of donor-derived cells was also monitored by flow cytometry. The homing and early phase proliferations of donor-derived cells were observed by two-photon microscope. RESULTS: The donor-derived cells started to proliferation from 5-7 days after transplantation and reached the peak value at 2-3 weeks after wBMMNC transplantation. The donor-derived cells proliferated from 1-2 weeks and maintained until 4 weeks after c-kit+HSPC transplantation. At 1 week after transplantation, the donor-derived cells mainly differentiated into myeloid cells with a few lymphoid cells production (B cells) but the production of T cells was not observed at most in wBMMNC transplanted group, while myeloid cells occupied the majority of donor-derived cells at 2-4 weeks; donor-derived cells almost totally differentiated into myeloid cells at 1-3 weeks after transplantation in c-Kit+ transplanted group and donor-derived B cells appeared at 4 weeks. The absolute number of donor-derived LKS- and LKS+ cells in the BM of c-Kit+ transplanted group were much higher than that of wBMMNC group (P＜0.001) at 2 weeks respectively. The clustering proliferation of cKit+ cells at 4-5 days after transplantation was observed by two photon microscope. CONCLUSION: The dynamical rate of proliferation and reconstitution of donor-derived cells are much earlier and quicker in c-Kit+ group than those of wBMMNC group. c-Kit+ cells mainly differentiate into myeloid cells within 1-3 weeks and the lymphoid cell differentiation starts at 4 weeks after transplantation. The immediate proliferation and differentiation of c-Kit+ cells within 1 week maybe due to the urgent needs of hematopoietic regeneration under the myeloablated hosts.

Dual lanthanide-doped complexes: the development of a time-resolved ratiometric fluorescent probe for anthrax biomarker and a paper-based visual sensor.

In this work, a novel time-resolved ratiometric fluorescent probe based on dual lanthanide (Tb: terbium, and Eu: europium)-doped complexes (Tb/DPA@SiO2-Eu/GMP) has been designed for detecting anthrax biomarker (dipicolinic acid, DPA), a unique and major component of anthrax spores. In such complexes-based probe, Tb/DPA@SiO2 can serve as a stable reference signal with green fluorescence and Eu/GMP act as a sensitive response signal with red fluorescence for ratiometric fluorescent sensing DPA. Additionally, the probe exhibits long fluorescence lifetime, which can significantly reduce the autofluorescence interferences from biological samples by using time-resolved fluorescence measurement. More significantly, a paper-based visual sensor for DPA has been devised by using filter paper embedded with Tb/DPA@SiO2-Eu/GMP, and we have proved its utility for fluorescent detection of DPA, in which only a handheld UV lamp is used. In the presence of DPA, the paper-based visual sensor, illuminated by a handheld UV lamp, would result in an obvious fluorescence color change from green to red, which can be easily observed with naked eyes. The paper-based visual sensor is stable, portable, disposable, cost-effective and easy-to-use. The feasibility of using a smartphone with easy-to-access color-scanning APP as the detection platform for quantitative scanometric assays has been also demonstrated by coupled with our proposed paper-based visual sensor. This work unveils an effective method for accurate, sensitive and selective monitoring anthrax biomarker with backgroud-free and self-calibrating properties.

Decreased expression of interleukin-27 in immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is an immune-mediated disorder in which disturbed cytokine profiles have been found. Interleukin-27 (IL27) has been shown to bear both proinflammatory and anti-inflammtory effects. In the present study, plasma levels of IL27, interferon gamma (IFNG), IL4, and IL17A were determined by enzyme-linked immunosorbent assay in 23 active ITP patients, 20 patients in remission and 20 healthy controls. mRNA expression levels of IL27, EBI3, IL27 receptor (IL27RA), IL17A and RAR-related orphan receptor C (RORC) were determined by real-time quantitative polymerase chain reaction. Significantly lower levels of plasma IL27, IL4, mRNA expression of IL27, EBI3 and higher levels of plasma IFNG as well as mRNA expression of IL17A, RORC were observed in active ITP patients compared with healthy controls or patients in remission. No statistical difference was found in IL27RA mRNA expression or plasma IL17A levels among active ITP patients and controls. A negative correlation was found between the IL27 and RORC mRNA expression levels in active ITP patients. Our data demonstrated that active ITP patients had decreased plasma and mRNA expression levels of IL27, suggesting that it might be involved in the pathophysiological process of ITP.

Determination of platelet-bound glycoprotein-specific autoantibodies by flow cytometric immunobead assay in primary immune thrombocytopenia.

OBJECTIVES: Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by premature platelet destruction induced by autoantibodies directed against platelet glycoproteins (GPs). Despite being a clinically important disorder, ITP lacks a feasible diagnostic assay for routine clinical use. This study was meant to evaluate a newly developed flow cytometric immunobead assay for determination of platelet-bound GP-specific autoantibodies in comparison with indirect monoclonal antibody-specific immobilization of platelet antigen (MAIPA) in the diagnosis of ITP. METHODS: Platelet-bound and plasma GPIIb/IIIa and GPIb/IX autoantibodies were determined by flow cytometric immunobead assay and indirect modified MAIPA, respectively. The average fluorescence level for platelet-bound, GP-specific autoantibodies was given as a ratio to three normal controls tested simultaneously. RESULTS: The median value of platelet-bound GPIIb/IIIa and GPIb/IX autoantibodies in ITP group were 3.09 (range 0.78, 30.2) and 3.09 (range 0.72, 19.2), respectively, which were significantly higher than non-ITP group [1.01 (0.67, 5.59) and 1.01 (0.79, 5.56), respectively, P<0.001] and normal controls [1.02 (0.72, 1.76) and 1.03 (0.79, 1.73), respectively, P<0.001]. The receiver-operating characteristics curve analysis showed an area under the curve of 0.895 for GPIIb/IIIa autoantibody and 0.859 for GPIb/IX autoantibody, respectively. Combined detection of GPIIb/IIIa or GPIb/IX autoantibodies by flow cytometric immunobead assay showed a sensitivity of 82.11% for ITP diagnosis. CONCLUSION: This study demonstrated that determination of platelet-bound, GP-specific autoantibodies by flow cytometric immunobead assay was a convenient, sensitive, and specific test for the differential diagnosis of thrombocytopenic patients.

High-dose dexamethasone shifts the balance of stimulatory and inhibitory Fcgamma receptors on monocytes in patients with primary immune thrombocytopenia.

The human Fcγ receptor (FcγR) system is composed of 2 opposing families, the activating FcγRs (FcγRI, FcγRIIa, and FcγRIII) and the inhibitory FcγR (FcγRIIb). The disturbed balance of the activating and inhibitory FcγRs has been implicated in the pathogenesis of many autoimmune diseases. In this study, the expression of FcγRs on monocytes was determined in 23 patients with primary immune thrombocytopenia (ITP) before and after high-dose dexamethasone (HD-DXM) treatment. The FcγRI expression was significantly higher in ITP patients and decreased after HD-DXM treatment. The ratio of FcγRIIa/IIb mRNA expression on monocytes was significantly higher in untreated patients than in healthy controls. After HD-DXM therapy, the ratio decreased and the increased expression of FcγRIIb mRNA and protein coincided with a remarkable decrease in the expression of FcγRIIa, FcγRI, and monocyte phagocytic capacity. There was no significant difference in FcγRIII expression on monocytes between patients and controls. In vitro cell-culture experiments showed that DXM could induce FcγRIIa and FcγRIIb expression in monocytes from ITP patients, with FcγRIIb at higher amplitudes. These findings suggested that the disturbed FcγR balance might play a role in the pathogenesis of ITP, and that HD-DXM therapy could shift monocyte FcγR balance toward the inhibitory FcγRIIb in patients with ITP.

[Correlation of insulin-like growth factor-1 (IGF-1) to angiogenesis of breast cancer in IGF-1-deficient mice].

BACKGROUND & OBJECTIVE: Insulin-like growth factors (IGFs) play important roles in the development and progression of tumors. But the mechanism of tumorigenesis in relation to IGF-1 is unclear yet. This study was to explore the correlation of circulating IGF-1 level to the angiogenesis of breast cancer in IGF-1-deficient mice. METHODS: The liver-specific IGF-1-deficient (LID) mice and control mice were injected with 7,12-dimethybenz(a)anthracene (DMBA) to develop breast cancer. Ginsenoside Rg3 was used to intervene tumor growth. The occurrence rates of breast cancer were compared. The expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) was detected by immunohistochemistry. RESULTS: The occurrence rate of breast cancer was 66.67% in untreated control mice, 33.33% in untreated LID mice, 36.00% in Rg3-treated control mice, and 12.00% in Rg3-treated LID mice. The tumor size was (0.79+/-0.20) cm in untreated control mice, (0.37+/-0.08) cm in untreated LID mice, (0.32+/-0.08) cm in Rg3-treated control mice, and (0.15+/-0.05) cm in Rg3-treated LID mice. The average light density and positive rate of VEGF were the highest in untreated control mice (0.34+/-0.10 and 0.04+/-0.02, P<0.05), and the lowest in Rg3-treated LID mice (0.13+/-0.03 and 0.01+/-0.00, P<0.05). The MVD was 31.9+/-5.3 in untreated control mice, 26.8+/-4.9 in untreated LID mice, 20.1+/-4.9 in Rg3-treated control mice, and 14.4+/-4.9 in Rg3-treated LID mice. CONCLUSIONS: Circulating IGF-1 plays a role in the onset and development of breast cancer. Degrading serum IGF-1 level could inhibit angiogenesis and growth of breast cancer. Rg3 could promote this effect.