Proventive and Therapentic Effects of Endothelial Progenitor Cells on Monocrotaline-Induced Hepatic Vein Occlusion Disease / 中国实验血液学杂志

OBJECTIVE@#To investigate the preventive and therapeutic effects of endothelial progenitor cells on monocrotaline-induced hepatic vein occlusion disease in mice.@*METHODS@#C57BL/6 mice were randomly divided into 3 groups: saline group (n=15), monocrotaline group (n=15), and endothelial progenitor cell infusion group (n=15). Liver function (TBIL, ALT, AST), liver index, and serum levels of TNF-α and IL-6 were measured on the 8 day after intragastric administration. Hepatic sinusoidal endothelial cells, hepatic central venous endothelial cells and hepatocytes were observed by both HE and immunohistochemical staining. Hepatic fibrosis was observed by Masson's trichrome staining.@*RESULTS@#By the light microscopy, the liver of the monocrotaline group showed moderate to the severe injuries of hepatic sinusoidal and central venous endothelial cells, and hepatic venous congestion. Masson staining showed moderate to severe hepatic fibrosis of central vein and hepatic sinus. In the endothelial progenitor cell group, hepatic sinusoidal and central venous endothelial cell injuries, and the fibrosis of central hepatic vein and hepatic sinus were mild to moderate. Hepatic venous congestion was reduced in comparison with that in the mice of the monocrotaline group. Compared with the endothelial progenitor cell group, the liver index was higher, the liver function was more abnormal, and the serum expression levels of TNF-α and IL-6 were higher in the monocrotaline group.@*CONCLUSION@#The monocrotaline-induced damage of hepatic sinusoidal and central venous endothelial cells is an linitiating factor for hepatic vein occlusive disease. Infusion of endothelial progenitor cells can play a role in preventing and treating hepatic vein occlusion.

Research Progress on role of Abnormal Tryptophan Metabolism in Immune Thrombocytopenia / 中国实验血液学杂志

Immune thrombocytopenia (ITP) is a common acquired autoimmune hematological disorders. Platelet autoantibodies lead to the decrease of platelet production and (or) increase of its destruction. The latest researches showed that the abnormal tryptophan metabolism mediated by indoleamine-2, 3-dioxygenase(IDO) is related with the pathogenesis of ITP. The patients with ITP show less expression of IDO, reduction of Treg cells and increase of autoreactive T cells and autoantibodies. CTLA-4-Ig can improve the expression of IDO in the patients with ITP, which also can inhibit the proliferation and activation of self-reactive T cells. Thus, clarifying the abnormal tryptophan metabolism mediated by IDO may provide a new idea for improving the understand of the pathogenesis and treatment of ITP. This review focuses on reasearch progress of the tryptophan metabolism mediated by IDO and ITP.

Role of dendritic cells and their Toll-like receptor 4 in the pathogenesis of idiopathic thrombocytopenic purpura / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the surface antigen of the dendritic cells (DC) and their Toll-like receptor 4 (TLR4) expression in patients with idiopathic thrombocytopenic purpura (ITP), and to explore their role in ITP pathogenesis.</p><p><b>METHODS</b>The peripheral blood mononuclear cells isolated from complete remission patients (CR), non-complete remission patients (n-CR) and normal controls were stimulated by rhGM-CSF and rhIL-4. The surface antigen of the DC was analyzed by flow cytometry. The level of IL-12p70 in the supernatant was detected by enzyme linked immunosorbent assay. The expression of TLR4 mRNA of DC was detected by real time PCR.</p><p><b>RESULTS</b>In the 21 CR ITP patients, the expression of both CD80 and CD86 in DC was significantly increased compared with that in normal controls \[(51.60 ± 13.47)% vs (36.03 ± 15.43)%, (61.50 ± 15.93)% vs (40.28 ± 11.49)%, respectively\] (P < 0.01). The expression of CD80 and CD86 in n-CR group was also significantly increased \[(53.29 ± 19.49)% and (62.91 ± 18.43)%, respectively\] (P < 0.01). After HD-DXM treatment, both CD80 and CD86 in CR patients were decreased (P < 0.01). There was no difference between the DXM treatment patients and the normal controls. In n-CR group, there was no difference in CD80 and CD86 expression before and after DXM therapy \[(52.30 ± 20.98% and (49.79 ± 20.28)%, respectively\] (P > 0.05). CD80 was still higher than normal (P < 0.05), while CD86 was not changed. The level of IL-12p70 in CR ITP patients before treatment was significantly higher \[(67.52 ± 14.43) pg/ml\] than that of the controls \[(39.78 ± 10.03) pg/ml\](P < 0.01), and after treatment, was significantly decreased to (43.90 ± 8.49) pg/ml, being no difference from that in control. In n-CR group, IL-12p70 was lower after treatment \[(48.45 ± 9.68) pg/ml\] than that before treatment \[(65.35 ± 12.52) pg/ml\] (P < 0.01), but still higher than that in control (P < 0.05). The TLR4 mRNA level in DCs of CR ITP patients before treatment were significantly higher 0.69 ± 0.17 than that of controls (0.31 ± 0.09) (P < 0.01) and after treatment, was reduced to 0.35 ± 0.11, being no difference from that in control. In n-CR group, TLR4 mRNA was decreased from 0.65 ± 0.09 to 0.52 ± 0.21 after treatment (P < 0.01), but still higher than normal (P < 0.01).</p><p><b>CONCLUSION</b>DC may play an important role in ITP by their Toll-like receptor and cytokine secretion.</p>

Study of a humanized anti-platelet GP VI single chain Fv phage antibody / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the anti-platelet GPVI single chain Fv phage antibody which can inhibit the aggregation function of platelet by using phage antibody library technology.</p><p><b>METHODS</b>ITP patients with anti-platelet GPVI autoantibody that could inhibit the aggregation function of platelet were screened by MAIPA assay and platelet aggregation test. The gene fragments of heavy chain and light chain variable region (VH and VL) of immunoglobulin were amplified by RT-PCR from peripheral blood lymphocytes mRNA of the screened patients. The VH and and VL fragments were linked through a DNA linker encoding the peptide (Gly4Ser)3 to construct single chain Fv (ScFv) gene. The ScFv gene was digested with SfiI/NotI restriction enzymes and cloned into the pHEN2 phage display vector, then electrically transformed to E. coli TG1. The TG1 containing ScFv-pHEN2 was rescued by helper phage M13K07 to produce ScFv phage antibody. The anti-platelet GPVI phage ScFv antibody was enriched and purified. The effect of the phage antibody on platelet aggregation function was studied.</p><p><b>RESULTS</b>Of 806 chronic ITP patients, 11 (1.36%) were positive for anti-platelet GPVI autoantibody and 2 (0.24%) patients'plasma significantly inhibited the collagen induced platelet aggregation. The length of VH and VL fragments was about 380 to 400 bp, and were successfully formed ScFv fragments of about 800 bp by DNA linker. After cloning ScFv to phagemid vector pHEN2 and transforming ScFv-pHEN2 to TG1, 4.1x10(7) clones were obtained. After M13K07 rescue, 2.62x10(10) cfu/ml ScFv phage antibodies were produced. The purified anti-platelet GPVI ScFv phage antibody inhibited the collagen induced platelet aggregation.</p><p><b>CONCLUSION</b>Anti-platelet GPVI ScFv phage antibody produced by phage antibody library technology can inhibit the aggregation function of platelet.</p>

Advances in the studies of platelet glycoprotein VI (GPVI): review / 中国实验血液学杂志

Platelet glycoprotein VI (GPVI) is a major receptor for collagen on the platelet surface. It mediates the initial platelet contact with collagen, generates intracellular signals, increases the affinity of integrin receptor, and causes platelet aggregation and thrombosis. Suppression of GPVI function can significantly inhibit collagen-induced platelet adhesion, aggregation and thrombosis, so GPVI has become a novel target for antiplatelet therapy. Within the last few years, major advances have been made in understanding platelet-collagen interactions. In this paper, the advances of study on GPVI, including composition of GPVI, functions of GPVI, factors related with functions of GPVI, GPVI and clinic were summarized.

The immunoreactivity of IgG and its fragments from ITP patients and their effects on platelet aggregation function / 中华血液学杂志

<p><b>OBJECTIVE</b>To prepare ITP plasma IgG and its F(ab')2 fragments and investigate their immunoreactivity to platelet GPIIb/IIIa and/or GPIb/IX and their effects on platelet aggregation function.</p><p><b>METHODS</b>The ITP patients having inhibitory autoantibody to the platelet aggregation were selected by modified MAIPA and platelet aggregation test with turbidimetry. Plasma IgG and its F(ab')2 fragments were prepared by streptococcal protein A affinity column and pepsin digestion. The immunoreactivity and the effects on platelet aggregation function of the whole antibody and its fragments were detected by modified MAIPA and platelet aggregation test, respectively.</p><p><b>RESULTS</b>(1) Anti-platelet GPIIb/IIIa and/or GPIb/IX autoantibodies were detected in 34 of 68 (53.6%) ITP patients' plasmas and that from 5 patients significantly inhibited the platelet aggregation induced by ADP or ristocetin. (2) By using protein A column combined with protease digestion, pure IgG and its F(ab')2 fragments were successfully obtained. (3) The purified IgG and its F(ab')2 fragments retained the ability to bind to their respective glycoproteins and inhibited the platelet aggregation function, whereas the IgG depleted plasma lost the ability of binding to the platelet GPs.</p><p><b>CONCLUSIONS</b>F(ab')2 fragment of the IgG antibody is a functional fragment, which not only has the binding ability to the platelet GPs but also inhibits the platelet aggregation function in a dose-dependent manner.</p>

Advances in the studies of humanized anti-platelet antibody--review / 中国实验血液学杂志

Platelet plays an important role in bleeding and thrombotic diseases. Humanized anti-platelet antibodies have great clinical effects in treatment of ITP and preventing thrombosis. The important role of platelet in bleeding and thrombotic diseases, the present status of development on study of humanized anti-platelet antibody and its application in treatment of bleeding and thrombotic diseases were summarized in this review.