Interleukin-7 is decreased and maybe plays a pro-inflammatory function in primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is an autoimmune disease with many immune dysfunctions, including over-proliferation and apoptosis resistance of auto-reactive lymphocytes. This study aimed to determine the effects of interleukin (IL)-7 on the cytokine production and survival of peripheral blood mononuclear cells and bone marrow mononuclear cells from ITP patients. We found that the plasma IL-7 levels in peripheral blood from ITP patients were lower than that of the normal controls, and it had positive correlation with platelet counts. However, the levels of IL-7 did not change in bone marrow serum of ITP patients compared with that of normal controls. The result of further stimulation experiments in vitro showed that IL-7 up-regulated the apoptosis of autologous platelets, promoted the proliferation and secretion of interferon-γ, tumor necrosis factor-α as well as IL-10 of lymphocyte both from peripheral blood and bone marrow. As the role of IL-7 in apoptosis-resistance and stimulation of pro-inflammatory cytokines, we speculated that decreased IL-7 in peripheral blood, maybe, is a consequence of the negative feedback of the pro-inflammatory function in ITP patients.

[Stable Expression of Coagulation Factors by RPS6 Promoter].

OBJECTIVE: To screen better promoters and provide more powerful tools for basic research and gene therapy of hemophilia. METHODS: Bioinformatics methods were used to analyze the promoters expressing housekeeping genes with high abundance, so as to select potential candidate promoters. The GFP reporter gene vector was constructed, and the packaging efficiency of the novel promoter was investigated with EF1 α promoter as control, and the transcription and activities of the reporter gene were investigated too. The activity of the candidate promoter was investigated by loading F9 gene. RESULTS: The most potential RPS6 promoter was obtained by screening. There was no difference in lentiviral packaging between EF1 α-LV and RPS6-LV, and their virus titer were consistent. In 293T cells, the transduction efficiency and mean fluorescence intensity of RPS6pro-LV and EF1 αpro-LV were proportional to the lentiviral dose. The transfection efficiency of both promoters in different types of cells was in the following order: 293T>HEL>MSC; Compared with EF1 αpro-LV, RPS6pro-LV could obtain a higher fluorescence intensity in MSC cells, and RPS6pro-LV was more stable in long-term cultured HEL cells infected with two lentiviruses respectively. The results of RT-qPCR, Western blot and FIX activity (FIX∶C) detection of K562 cell culture supernatant showed that FIX expression in the EF1 α-F9 and RPS6-F9 groups was higher than that in the unloaded control group, and there was no significant difference in FIX expression between the EF1 α-F9 and RPS6-F9 groups. CONCLUSION: After screening and optimization, a promoter was obtained, which can be widely used for exogenous gene expression. The high stability and viability of the promoter were confirmed by long-term culture and active gene expression, which providing a powerful tool for basic research and clinical gene therapy of hemophilia.

CD72 gene expression in immune thrombocytopenia.

To explore the role of CD72 in the pathogenesis of immune thrombocytopenia (ITP), we detected CD72, Sema4D, IL-2, IL-4, and IFN-γ mRNA expressions and the levels of plasma Sema4D, IL-2, IL-4, IL-6, and IFN-γ in ITP patients (n = 39) and controls (n = 23). The levels of plasma IL-2, IL-4, and IL-6 were assayed by radioimmunoassay, and the levels of plasma IFN-γ and Sema4D were analyzed by enzyme-linked immunosorbent assay. Sema4D, CD72, IL-2, IFN-γ, and IL-4mRNA expressions were analyzed by real-time quantitative reverse-transcription polymerase chain reaction. The expression of CD72 mRNA in ITP patients (n = 23) with active disease was significantly lower than that in patients in remission (p = 0.029) (n = 16) and controls (p = 0.0296) (n = 23). The IFN-γ/IL-4 mRNA (Th1/Th2) expression in ITP patients with active disease and in remission was significantly higher than that in controls (p = 0.0023, p = 0.0125, respectively). The expression of IL-2 mRNA in ITP patients with active disease was significantly lower than that in patients in remission (p = 0.0418) and controls (p = 0.004). The level of plasma IL-2 in ITP patients with active disease was significantly lower than that in patients in remission (p = 0.0029) and controls (p = 0.0101). The levels of plasma IL-4 in ITP patients with active disease and in remission were significantly higher than that of controls (p = 0.0093, p = 0.0053, respectively). CD72 mRNA expression level might correlate with Sema4D mRNA expression in peripheral blood mononuclear cells and level of plasma IL-2 in active ITP patients (p = 0.024 and p = 0.036). Our findings suggest that CD72 might be involved in the pathophysiological process of the ITP disease by increasing B-cell receptor signals.

[Clinical and laboratory investigation of patients with hematologic malignancies harboring der(1;7)(q10;p10)].

OBJECTIVE: To investigate the clinical and laboratory characteristics of patients with various hematological malignancies harboring der(1;7)(q10;p10). METHODS: Bone marrow samples were collected and undergone short-time unstimulated culture and R-banding, and karyotyped by conventional cytogenetic assay (CCA). Megalokaryocytes were detected by streptavidin-AKP (SAP). Retrospective analyses including the clinical and laboratory data were performed. RESULTS: Nineteen of the 21 patients were male. Most of the patients are of older age. Thirteen cases (61.9%) were der(1;7)(q10;p10) without additional aberrations, 8(38.1%) patients had additional aberrations. Sixteen out of the 18 cases (88.9%) who underwent SAP analysis had diminutive megalokaryocyte, and lymphoid megalokaryocyte was found in 10 cases (55.6%). The der(1;7) patients manifested poor response to treatment. CONCLUSION: The der(1;7) patients demonstrated distinct male predominance, older age at diagnosis, and some clinically distinctive features. These patients showed poor prognosis. The cytogenetic abnormality, i.e., der(1;7)(q10;p10), can be used as a prognostic indicator.

[Clinical Analysis of Hospitalized Children with Primary Immune Thrombocytopenia].

OBJECTIVE: To investigate the factors affecting the chronicity of childhood primary immune thrombo-cytopenia (ITP) and compare the efficiency of different first-line treatment regimens. METHODS: Children with ITP hospitalized in our hospital from September 2013 to October 2018 were retrospectively analyzed. RESULTS: Three hundred and one children (150 males and 151 females) were included in this study, with a median age of 8 (0.17-17) years old, and 110 (36.5%), 92 (30.6%), and 99 (32.9%) cases were grouped into newly diagnosed, persistent, and chronic ITP, respectively. The median of follow-up was 41.92 (1.07-74.03) months. At the end of the follow-up (October 2019), among the 202 newly diagnosed/persistent ITP children, 79 cases (59 newly diagnosed and 20 persistent ITP) achieved remission within 1 year after initial diagnosis, with a remission rate of 39.3%; 122 cases (50 newly diagnosed and 72 persistent ITP) developed chronic disease, with a chronicity rate of 60.7%; one case underwent splenectomy. In 99 cases with chronic ITP, 5 cases underwent splenectomy. Multivariable logistic regression analysis showed that, the insidious onset of symptoms (OR=3.754, 95%CI: 1.882-7.488, P=0.000) increased the risk of chronicity, while the positive antibody to anti-platelet membrane glycoprotein (OR=0.446, 95%CI: 0.224-0.888, P=0.021) might reduce the risk of chronicity. And no difference was found by the analysis of subtype of anti-platelet membrane glycoprotein (P=0.305). The efficacy of the first-line treatment of intravenous immunoglobulin (IVIG) alone or combined with steroid was better than that of steroid alone (P=0.028, 0.028), however, the efficiency was not significantly different between IVIG alone and combined with steroid (P=0.086). CONCLUSION: Insidious onset of symptoms in pediatric ITP increases the risk of chronicity, while the positive titer of anti-platelet membrane glycoprotein may reduce the risk. In the first-line treatment for the newly diagnosed/persistent children. The efficacy of IVIG alone or combined with steroid is better than that of steroid alone.

[The role of DNA methylation in the pathogenesis of adult idiopathic thrombocytopenic purpura].

OBJECTIVE: To explore the role of DNA methylation in pathogenesis of adult idiopathic thrombocytopenic purpura (ITP). METHODS: We measured DNA methyltransferases (DNMTs) 1, 3A and 3B mRNA expression in peripheral blood mononuclear cells of 48 adult ITP patients and 36 normal controls using real-time polymerase chain reaction, as well as the plasma levels of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) with reversed phase high performance liquid chromatography (HPLC). Furthermore, we determined the expression of CD(11a)/LFA-1 on CD(4)(+) or CD(8)(+) T cells by three-color flow cytometry. RESULTS: The mRNA expression of two DNA methyltransferases (DNMT3A and DNMT3B) was significantly lower when comparing ITP patients with healthy controls (P < 0.01). Although there were decreased tendency when comparing expression of DNMT1 of ITP patients with healthy controls, no significant differences were found (P > 0.05). The SAH concentration in the plasma of ITP patients was significantly elevated than that in the healthy controls (P < 0.05). However we found significant differences of SAM and SAM/SAH ratio in the plasma of ITP patients when compared with the healthy subjects (both P > 0.05). In addition, CD(11a)/LFA-1 expression on CD(8)(+) T lymphocytes increased in ITP patients compared with the control group (P < 0.01), whereas CD(11a)/LFA-1 expression on CD(4)(+) T lymphocytes and CD(4)(+)CD(11a)(+)/CD(8)(+)CD(11a)(+) ratio was significantly decreased in ITP patients than that in control group (both P < 0.01). CONCLUSION: Aberrant DNA methylation in peripheral blood and CD(11a)/LFA-1 expression on T cell surface may play an important role in the pathogenesis of ITP, although the underlying mechanisms still await further investigation.

[Symptomatic Profiles of 173 Chinese Patients with Essential Thrombocythemia].

OBJECTIVE: To explore the symptomatic burden of patients with essential thrombocythemia (ET) and its relation with clinical characteristics including the mutation status, therapeutic protocols and sex. METHODS: Total of 173 Chinese ET patients were selected and grouped on the basis of disease characteristics (mutation status, therapeutic pro to- cols, and sex). RESULTS: All the groups showed low-to-high symptom burden, with the highest in the Hu (hydroxyurea)-group (total symptom score [TSS], 14.7; range, 7.6-14.7). In the JAK2V617F-positive, Hu-treated, and female groups TSS and independent symptom scores were higher than those in the control group. The CALR-positive and IFN-α-treated groups had lower overall and individual scores as compared with groups lacking the corresponding characteristics. As the number of characteristics (JAK2V617F-positive, Hu-treated, and female) increases, the severity of symptoms gradually increased. CONCLUSION: The different characteristics have various effects on symptom burden in ET patients. The accumulation of certain characteristics will lead to more severe symptom burden, thus the patient＇s symptom burden should be considered comprehensively when making up the treatment schemes and prognosis.

[Clinical Characteristic of "triple-negative" Essential Thrombocythaemia Patients and Mutation Analysis by Targeted Sequencing].

BACKGROUND: Essential thrombocythemia is a subgroup of myeloproliferative neoplasms. Previous studies identified mutations of JAK2, CALR, and MPL that are closely related with the pathogenesis of myeloproliferative neoplasms. All these mutations contribute to the hyperactivation of JAK2/STAT pathway. However, a small proportion of essential thrombocythemia patients does not display such mutations. The pathogenesis of "triple-negative" form of essential thrombocythemia remains unknown. OBJECTIVE: To investigate the clinical characteristics of triple-negative essential thrombocythemia and related mutation genes. METHODS: To identify the mutations associated with triple-negative essential thrombocythemia, next-generation sequencing was used to conduct targeted sequencing of 360 genes in samples from 68 patients. RESULTS: At least one missense mutation was detected in all the patients and all the detected genes. After screening the data, it was observed that 10 genes with the 10 highest mutation were follows: FLT3, SH2B3, ASXL1, ADAMTS1, TET2, TP53, EGFR, CUX1, GATA2, and MPL.When only rare genes (i.e., with a frequency in Asian populations lower than 5%, as estimated by the 1000 Genomes Project) were analyzed, the most frequently mutated genes in the patients were TET2 (33.82%), SH2B3(29.41%), and ASXL1 (23.53%). Our study identified some mutations that did not previously reported. Although all these mutations need further validation, high incidence rates may indicate relevance of the respective mutations to essential thrombocythemia pathogenesis. Some of the detected mutations have been previously reported; these mutations were also found in a large proportion of our subjects. CONCLUSION: whole-exon sequencing can provide a higher level of accuracy for gene mutation analysis and assist in identifying mutations that contribute to illustrate the pathogenesis of essential thrombocythemia.

Chinese guidelines for treatment of adult primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is a bleeding disorder commonly encountered in clinical practice. The International Working Group (IWG) on ITP has published several landmark papers on terminology, definitions, outcome criteria, bleeding assessment, diagnosis, and management of ITP. The Chinese consensus reports for diagnosis and management of adult ITP have been updated to the 4th edition. Based on current consensus positions and new emerging clinical evidence, the thrombosis and hemostasis group of the Chinese Society of Hematology issued Chinese guidelines for management of adult ITP, which aim to provide evidence-based recommendations for clinical decision making.

[Role of antiapoptotic Bcl-X(L) in megakaryocyte differentiation and maturation].

OBJECTIVE: To investigate the role of antiapoptotic Bcl-x(L) protein in megakaryocyte differentiation and maturation. METHODS: RNA interference was used to block the expression of Bcl-x(L) when K562 cells were induced to differentiate into megakaryocyte (CD61 + cells) by PDBu, and the expression of Bcl-x(L) was evaluated with flow cytometry and reverse transcription polymerase chain reaction (RT-PCR). The CD34 + cell fraction was positively isolated by using the MiniMACS system from normal bone marrow. Immunochemical staining and flow cytometry were used to detect the expression of Bcl-x(L) in the differentiation (CD41 + cells) of CD34 + cells induced by trombopoietin (TPO). RESULTS: Among K562 cells induced by PDBu, the percentage of CD6L + cells rapidly increased in 24 hours and maintained at a high positive level in 72 hours. When exposured to si-Bcl-x(L), the percentage of CD6 1 + cells only slightly increased in 72 hours. The expression of Bcl-x(L) mRNA was significantly decreased after transfection compared with that of control group, and Bcl-x(L) protein expression decreased correspondingly. After the CD34 + bone marrow cells having been treated with TPO for 5 days to 20 days, the Bcl-x(L)-megakaryocytes increased as the culture time prolonged, and there was a strong expression of Bcl-x(L) in immature megakaryocyte and an obviously decreased expression in degenerating megakaryocytes maturation. CONCLUSIONS: Increased expression of antiapoptotic Bcl-x(L) may be essential to mature megakaryocyte. The down-regulation of antiapoptotic Bcl-x(L) in mature megakaryocyte may be crucial to platelets formation.

[Clinical Characteristics and Long-Term Outcome of 125 Chinese Young Patients with Essential Thrombocythemia].

OBJECTIVE: To investigate the clinical characteristics and long-term outcome of Chinese young patients (≤40 years) with essential thrombocythemia(ET), and to develop a thrombosis predicting model specific for young patients with ET, so as to provide a new evidence for risk stratification and treatment. METHODS: Medical records of 125 Chinese young patients with newly diagnosed of ET were retrospectively analyzed. RESULTS: The median age at diagnosis was 32 (18-40) years old, with 37 males and 88 females. During follow-up, 18 patients (14.4%) experienced major thrombotic events. JAK2 V617F (HR=8.895, P=0.001), history of thrombosis (HR=8.001, P<0.001) and WBC≥12.0×109/L (HR=5.225, P=0.002) were independent risk factors for thrombosis. The incidence of thrombosis and risk factors in young patients were different from that in general ET population, so a thrombosis predicting model specific for young patients with ET was developed. In this model, JAK2 V617F (score 2), history of thrombosis (score 2) and WBC≥12.0×109/L (score 1) were used to divide the patients into low risk (score 0), intermediate risk (score 1-2) and high risk (score≥3) groups. These 3 groups exhibited significantly different thrombosis-free survival (χ2=32.223, P<0.001). Antiplatelet treatment could prevent the occurrence of thrombosis (HR=0.081, P<0.001), while cytoreductive agents significantly decreased the risk of thrombosis only in intermediate and high risk groups (14.3% vs 36.4%, χ2=4.416, P=0.036). Seven patients (5.6%) evolved to myelofibrosis, and one of them finally progressed in to acute leukemia. The only risk factor for evolution was WBC≥15.0×109/L (χ2=5.434, P=0.020). Neither antiplatelet treatment nor cytoreductive agents could prevent disease progression. CONCLUSION: The incidence of thrombosis and risk factors in young patients with ET are different from that in general ET population. The thrombosis-predicting model specific for young patients with ET is useful for guiding therapeutic decisions.

Polymorphisms in ERCC1 and susceptibility to childhood acute lymphoblastic leukemia in a Chinese population.

Excision repair cross-complementation group 1 (ERCC1) is important in repairing DNA damage and genomic instability, and polymorphisms in ERCC1 may play a role in human tumors. In this study, the relationship of two ERCC1 polymorphisms, 8092C>A and 19007G>A, with susceptibility to acute lymphoblastic leukemia (ALL) was investigated in 183 childhood patients. For the ERCC1 8092C>A polymorphism, individuals carrying the ERCC1 8092CC genotype had a significantly higher risk when compared with those carrying at least one A allele gene (AA/AC). Analysis after stratification for sex showed that the males carrying ERCC1 8092CC genotype were associated with highly significant increased risk of ALL (1.94-fold) but not females. There was no association between ERCC1 19007G>A polymorphism and ALL risk when all patients as a group were analyzed. However, the males carrying ERCC119007A allele were associated with highly significant increased risk of ALL (2.36-fold). For the ERCC1 8092C>A polymorphism, individuals under 8 years old (median age) carrying CC genotype had significantly higher risk. However, the 19007G>A polymorphism was not associated with such age-related ALL risk. These results suggest that the ERCC1 8092C>A polymorphism may be related to the occurrence of childhood ALL in a Chinese population.

[The effects of different post-remission treatment on long-term survival of acute promyelocytic leukemia].

OBJECTIVE: To Summarize and compare the effects of the different post-remission treatment on long-term survival in acute promyelocytic leukemia (APL) patients. METHODS: The long-term survival and relapse of 111 APL patients with different post-remission treatment were retrospectively analyzed. The patients were divided into four groups. Group 1: All-trans-retinoic acid (ATRA) + As(2)O(3) + chemotherapy; Group 2: ATRA + chemotherapy; Group 3: As(2)O(3) + chemotherapy; Group 4: chemotherapy alone. The median follow-up time was 32 (6 - 185) months. RESULTS: A total of 85 patients survived without diseases, 18 patients died and 8 patients dropped out. In the four groups, the patients survived without disease were (36/40, 23/30, 21/26, 5/15), respectively. The cases of patients survived over 3 years were (16/40, 12/30, 11/26, 1/15), respectively. The patients died were (3/40, 5/30, 5/26, 5/15), respectively. The estimated 5-year overall survival (OS) and relapse-free survival (RFS) were (78.3 +/- 4.9)%, (76.9 +/- 5.1)%, respectively. There were 21 patients relapsed. CONCLUSION: The APL patients receiving combined post-remission therapy had better OS and RFS those receiving chemotherapy alone. Sequential therapy combining ATRA, As(2)O(3) and chemotherapy is the best post-remission therapy for long-term survival of APL patients.

[Profiles of type 1 and type 2 T cells in chronic idiopathic thrombocytopenic purpura].

OBJECTIVE: To explore the profiles of type 1 and type 2 T cells in chronic idiopathic thrombocytopenic purpura (ITP) patients. METHODS: Samples of peripheral blood were collected from 30 chronic ITP patients, 8 males and 22 females, aged 34, 20 being in the active stage, and 10 in the remission stage, and 20 healthy persons, 7 males and 13 females, aged 31. Peripheral blood mononuclear cells (PBMCs) were isolated, cultured, and activated with PMA/ionomycin. Flow cytometry was used to measure the intracellular cytokines interferon (IFN)-gamma and interleukin (IL)-4 in the PBMCs so as to identify the Th1 cells (IFN-gamma(+) IL-4(+) CD4(+) cells), Th2 cells (IFN-gamma(-) IL-4(+) CD4(+) cells), Tc1 cells (IFN-gamma+ IL-4(-) CD8(+) cells), and Tc2 cells (IFN-gamma(-) IL-4(+) CD8(+) cells). The ratios of Th2/Tc2, Th1/Th2, and Tc1/Tc2 were calculated. Samples of spleen tissue were collected from 8 patients with chronic ITP, 3 males and 5 females, aged 30, and 6 patients with hereditary spherocytosis (HS), 3 males and 3 females, aged 35, who underwent splenectomy. Splenocytes were isolated, cultured, and activated with PMA/ionomycin. Real-time PCR was used to detect the mRNA expression of T-bet and GATA-3 in the PBMCs and splenocytes. RESULTS: The Th1/Th2 ratio of the patients in active stage was 25.62, significantly higher than those of the patients in remission stage (9.86) and the control (8.29, both P < 0.01), and the Tc1/Tc2 ratio of the patients in active stage was 30.23, significantly higher than those of the patients in remission stage (10.10) and the controls (12.58, both P < 0.01). The Th1/Th2 ratio of the splenocytes of the patients in active stage was 41.46, significantly higher than that of the controls (16.30, P < 0.01), and the Tc1/Tc2 ratio of the splenocytes of the active ITP patients was 35.80, not significantly higher than that of the controls (16.30, P = 0.082). The GATA-3 mRNA expression level of the PBMCs of the active ITP patients was one-fifth of that of the controls (P < 0.05) and the GATA-3 mRNA expression level of the splenocytes of the ITP patients was 0.34 of that of the HS patients (P < 0.05), however, there was no difference in the T-bet expression among the 3 groups. The T-bet/GATA-3 ratio of the PBMCs of the active ITP patients was 5.85 times that of the controls and the T-bet/GATA-3 ratio of the splenocytes of the active ITP patients was 2.68 times that of the controls (both P < 0.01). CONCLUSION: ITP is a T1 cells (Th1 and Tc1) predominant disease. The T-bet/GATA-3 ratio may provide a surrogate marker of T1/T2 cytokine balance. Shifting the cytokine patterns from T1 to T2 may be a potential immunotherapy for ITP.

Multi-dysfunctional pathophysiology in ITP.

Idiopathic thrombocytopenic purpura (ITP) is an organ-specific autoimmune disorder characterized by a low platelet count and mucocutaneous bleeding. The decrease of platelets is caused by increased autoantibodies against self-antigens, particularly IgG antibodies against GPIIb/IIIa. The production of these autoantibodies by B cells depends on a number of cellular mechanisms that form a network of modulation, with T cells playing a pivotal role in pathophysiology. Delineation of the dysfunction of cellular immunity has recently been attempted. This review will focus on these recent advances applicable to ITP and to highlight how these may translate into novel approaches to treatment in the future. Multi-dysfunction in these networks may include a failure of self-antigen recognition and tolerance, involvement of abnormal cell surface molecules, altered Th1/Th2 cytokine profiles, impaired megakaryocytopoiesis and impaired cell-mediated cytotoxicity. In ITP, multi-step dysfunctions in these networks may take place that finally lead to the occurrence of the disease. Therefore, unveiling these dysfunctions is vital in understanding the pathophysiology of ITP and will finally lead to the development of new therapies to fight the disease.

Chronic idiopathic thrombocytopenic purpura in adult Chinese patients: a retrospective single-centered analysis of 1791 cases.

BACKGROUND: Adult chronic idiopathic thrombocytopenic purpura (ITP) is a common hematologic disease characterized by persistent thrombocytopenia. So far, there were only a few reports on adult Chinese patients with chronic ITP. This study aimed at defining the treatment outcome and prognostic factors for chronic ITP based on a large cohort of Chinese patients followed up for over 25 years at a single center. METHODS: The medical records of 1791 patients aged 14 years or older who were diagnosed as having chronic ITP at our hospital from 1974 to 1999 were retrospectively analyzed. RESULTS: The female-to-male ratio was 2:1, with a median age of 34 years (ranging from 14 to 80 years), median platelet count of 38 x 10(9)/L [range (1-99) x 10(9)/L], and median follow-up of 36 months (range 1-220 months). Steroids were used in 689 patients, among them 209 (30.3%) achieved complete remission (CR). A splenectomy was performed in 124 patients, and response to steroid pre-splenectomy was not available in 14 patients. The CR rate after a splenectomy was lower in steroid nonresponders (29 of 90, 32.2%) than in those who relapsed after successful steroid treatment (12 of 20, 60.0%) (P < 0.05). In comparison with patients negative for antinuclear antibody (ANA), those who were ANA positive had similar responses to steroids, but a significantly shorter remission period after a splenectomy (P < 0.01). CONCLUSIONS: Adult Chinese chronic ITP patients can have long-term remission after steroid therapy and splenectomies. Primary steroid refractoriness is a prognostic factor predicting poor subsequent response to a splenectomy.

[Expression of alternatively spliced isoforms of platelet endothelial cell adhesion molecule-1 of embryonic stem cells during vasculogenesis and angiogenesis].

OBJECTIVE: To study the expression of alternatively spliced isoforms of platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) of embryonic stem cells (ES cells) during vasculogenesis and angiogenesis. METHODS: Mouse ES cells of the line J1 were cultured. Another ES cells were cultured in differentiation medium to induce the formation of embryonic bodies (EBs). Then the ES cells with PECAM-1 and EBs were inoculated with methylcellulose into Petri dish, containing cell growth factor, VEGF, bFGF, EPO, and IL-6 and the ES cells cultured for 11 days were inoculated in the Petri dish with collagen for 72 hours so as to induce sprouting angiogenesis. Immunofluorescence analysis, RT-PCR, and flow cytometry were used to detect the expression of PECAM-1, Oct-4, and stage-specific embryonic antigen (SSEA)-1 in the undifferentiated ES cells, EBs, and EB sprouting. In order to delineate the alternatively spliced cytoplasmic domain isoforms of PECAM-1 specific primers were designed to span the exon-exon junctions in the regions of alternative splicing. In order to amplify the cytoplasmic domains of all possible PECAM-1 isoforms a sense primer spanning the border of exons 9 and 10 within the cytoplasmic domain and an antisense primer spanning the border of exon 16 and 3'-untranslated region were used. Then the PCR products of the cytoplasmic domain underwent subsequent sequencing to analyze the expression of the 8 known alternatively splice isoforms of PECAM-1. RESULTS: The ES cells expressed high level PECAM-1 that was mainly located at the cell-cell junctions. The SSEA-1 and Oct-4 levels rapidly decreased along with the differentiation of the ES cells. All 8 known alternatively splice isoforms of PECAM-1 were expressed in the ES cells and the EB sprouting, the expression of Delta14%15 and Delta12&14&15 being the highest. The expression level of Delta12&14&15 increased markedly and the expression of Delta15 decreased along with the differentiation of ES cells. CONCLUSION: PECAM-1 is a constitutive feature of undifferentiated ES cells. Its changes in splice form mark the differentiation and may participate in vasculogenesis and angiogenesis.

[In vitro vasculogenesis and angiogenesis of mouse embryonic stem cells].

OBJECTIVE: To explore an optional condition to induce mouse embryonic stem (ES) cells to differentiate into endothelial cells and to establish in vitro models of vasculogenesis and angiogenesis. METHODS: Mouse ES cells were cultured in differentiation medium containing a cocktail of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), interleukin-6 (IL-6) and erythropoietin (EPO) in 1% methylcellulose to induce formation of embryoid bodies (EBs). At day 11, EBs were harvested and suspended in rat-tail collagen type I with the same cocktail of cytokines cultured for three additional days. The differentiation of ES cells into endothelial cells, processes of vasculogenesis and angiogenesis were examined using immunostaining of EBs slices and whole-mount immunocytochemistry of EBs with monoclonal antibodies (mAbs) against platelet endothelial cell adhesion molecule-1 (PECAM-1) and alpha-smooth muscle actin (SMA). RESULTS: Under appropriate culture conditions; ES cells spontaneously differentiated and formed EBs containing vascular structures and tubular channels, which were positive for PECAM-1 co-differentiated with smooth muscle. When not treated with angiogenic growth factors, PECAM-1-positive cells could not organize into vascular structures of 11-day-old EBs. In the presence of angiogenic factors 11-day old EBs embedded into type I collagen, and rapidly developed an endothelial networks. Whole-mount immunocytochemistry of collagen gel with anti-PECAM-1 antibody showed the formation of primary vascular structures sprouting from EBs. Quantitative analysis revealed that 100 microg/ml thalidomide significantly reduced the number and length of EBs endothelial sprouting. CONCLUSIONS: Mouse ES cells can differentiate into endothelial cells combined with smooth muscle differentiation during EBs formation and further develop endothelial outgrowths after EBs embedded into collagen, which respectively recapitulate vasculogenesis, angiogenesis, and arteriogenesis processes in vivo. The models provide a useful tool to investigate vasculogenesis, angiogenesis, and arteriogenesis mechanisms and evaluate the effects of angiogenic and angiostatic agents.

Inhibition of K562 leukemia angiogenesis and growth by expression of antisense vascular endothelial growth factor (VEGF) sequence.

Vascular endothelial growth factor (VEGF), a major angiogenic factor, plays a key role in the growth of solid tumor. Recently, expression of VEGF and its receptors has been found on leukemic cells as well as on endothelial cells. VEGF may fulfill a fundamental role in promoting tumor angiogenesis and proliferation by stimulating both endothelial cells and leukemic cells. To investigate the role of VEGF in the angiogenesis and growth of leukemic cell, we used an antisense strategy to downregulate VEGF expression in K562 cells, a human erythroleukemia cell line. Expression of antisense-VEGF in K562 cells reduced the secretion of VEGF protein and inhibited cell survival. The proliferation and migration of human umbilical vein endothelial cells were decreased in response to the conditioned medium (CM) from K562 cells expressed antisense-VEGF, compared to CM from K562 cells transfected with vector control. Moreover, subcutaneous injection of nude mice with antisense-VEGF K562 cells inhibited tumor growth with a reduction of the density of microvessels and an increased apoptosis in those tumors, compared to vector control K562 cells. These results suggest that the efficient downregulation of the VEGF production in leukemic cells using antisense-VEGF may constitute a novel strategy of treatment in leukemia.

Autologous transplantation of peripheral blood stem cells as an effective therapeutic approach for severe arteriosclerosis obliterans of lower extremities.

Treatment of severe arteriosclerosis obliterans of lower extremities (ASOLE) remains a clinical challenge. To develop a more effective approach, we evaluated the clinical efficacy of autologous transplantation of mobilized peripheral blood stem cells (PBSCs) in 5 patients with ASOLE. The patients received recombinant human granulocyte colony-stimulating factor (rhG-CSF, 600 micro g/day) for 5 consecutive days. On day 5, PBSCs were collected, sorted from blood circulation of patients, and then intramuscularly injected into their ischemic lower limbs. A significant improvement of clinical manifestations including severe pain, skin temperature and ulcer, was observed, without obvious adverse effect. The patient's limb was successfully saved. Satisfactory remission was obtained 3 months after transplantation as shown by significant improvement in ankle-brachial pressure index (ABI), blood flow in personal vascular laboratory (PVL), laser Doppler blood perfusion, and the angio-graphic scores. Our data suggest for the first time that autologous transplantation of mobilized PBSCs provides a practical, safe, and effective method of treatment for lower limb ischemia.