BACKGROUND: Imatinib has a significant pro-apoptosis effect on chronic myelogenous leukemia (CML), but there are still some patients being resistant to it. Human umbilical cord mesenchymal stem cells (hUC-MSCs) affect the apoptosis of a variety of hematologic malignancies. However, the impacts of hUC-MSCs on the apoptosis of CML cells induced by imatinib remain unclear.OBJECTIVE: To investigate whether hUC-MSCs have an influence on the apoptosis of K562 cells induced by imatinib and to reveal the possible underlying mechanism.METHODS: K562 cells were cultured with hUC-MSCs or/and imatinib. Cellular apoptosis was measured with Annexin-V and PI staining by flow cytometry analysis. The protein expressions of Bax, Bcl-2, caspase-3, caspase-9 and cleaved-PARP in K562 cells were detected by western blot assay. Pan-caspase inhibitor Z-VAD-FMK was used to block apoptosis in each group, and during this process the effect of caspase apoptosis signaling pathway was detected.RESULTS AND CONCLUSION: The apoptosis of K562 cells was enhanced, when imatinib was combined with hUC-MSCs. Western blot analysis showed that the expression of pro-apoptotic protein Bax was enhenced and the expression of anti-apoptotic protein Bcl-2 was suppressed. Furthermore, the cleaved forms of caspase-9, caspase-3 and PARP in K562 cell were higher in the hUC-MSCs+imatinib group than in the imatinib group. The apoptosis of K562 cells induced by the hUC-MSCs combined with imatinib was significantly inhibited by Z-VAD-FMK. In conclusion, these findings indicate that hUC-MSCs can enhance imatinib-induced apoptosis of K562 cells by activating caspase apoptosis signaling pathway.

OBJECTIVETo analyze the ultra microstructures and the expression of platelet peroxidase (PPO) of megakaryocytes from bone marrow, their clinical manifestations and laboratory characteristics in patients with acute megakaryoblastic leukemia (AMKL).

METHODSKaryocytes from bone marrow of 22 AMKL patients were divided into two parts by lymphocyte separation liquid, one part was used to prepare the ordinary transmission electron microscope specimens to observe the morphological structures of megakaryocytes, the other was used to prepare the histochemical specimens of platelet peroxidase to analyze the positive reaction of PPO in AMKL, which were coupled with the patients' data of with bone marrow morphology, cell chemistry, and chromosome karyotype examination.

RESULTSMegakaryocytes from 17 of 22 patients were in the first stage, less than 20 µm in diameter, the nucleis were round, the cytoplasm contained microtubules, membranous vesicles and minute dense granules, no demarcation membrane system and surface-connected canalicular system, less dense granules and α-granules; Megakaryocytes in 5 cases were mainly in the first stage, while containing second and third stage megakaryocytes; the positive rate of PPO in megakaryocytes of 22 patients was 0-80%. The primitive and naive megakaryocytes were found in bone marrow smears of 22 cases, CD41 staining of the megakaryocytes was detected in the primitive and naive megakaryocytes, and more complex chromosome karyotype anomalies were observed.

CONCLUSIONThe majority of megakaryocytes in AMKL patients were the first stage ones, the rest were second and third stage ones, and the positive PPO reaction was significantly different. CD41 staining of the megakaryocytes was specific with complex chromosome karyotypeswere.

Blood Platelets ; enzymology ; Bone Marrow ; pathology ; Cell Count ; Chromosome Aberrations ; Chromosome Disorders ; Humans ; Karyotyping ; Leukemia, Megakaryoblastic, Acute ; diagnosis ; pathology ; Megakaryocytes ; pathology ; Peroxidase ; metabolism ; Staining and Labeling

OBJECTIVETo investigate the distribution characteristics of blood cells autophagy in hematologic diseases, as well as their possible pathomechanism.

METHODSRetrospective analysis of electron microscopy specimens of 3 277 patients with hematological diseases were performed. The blood cells autophagy was observed by transmission electron microscopy, and its distribution characteristics were analyzed. The pathomechanism of blood cell autophagy was explored in combination with clinical examination and diagnosis.

RESULTSThere were 15 samples were found to have mature granulocytes or nucleated erythrocytes autophagy. Of them, 6 cases were myelodysplastic syndrome (MDS), 2 acute leukemia, 1 in each of aplastic anemia, pure red cell aplastic anemia, thalassemia, iron deficiency anemia, lymphoma, multiple myeloma and polycythemia vera. Among 15 cases, 11 cases were found to have mature granulocytes autophagy, 4 cases nucleated erythrocytes autophagy. Besides autophagy, apoptosis occurred in 9 cases, cytolysis in 6 cases, megaloblastic change in 5 cases.

CONCLUSIONMature granulocytes or nucleated erythrocytes autophagy occurred more frequently in MDS among hematologic diseases, dyshaematopoiesis including apoptosis, cytolysis and megaloblastic change could induce autophagy function enhancement.

Apoptosis ; Autophagy ; Erythroblasts ; Granulocytes ; Hematologic Diseases ; Humans ; Microscopy, Electron, Transmission ; Retrospective Studies

Objective:To explore the laboratory characteristics and diagnostic methods for therapy-related acute megakaryocytic leukemia (t-AMKL).Methods:The data of one child with acute lymphoblastic leukemia (ALL) in the Blood Disease Hospital of Chinese Academy of Medical Sciences & Peking Union Medical College in September 2014 was retrospectively analyzed. After inducing remission for more than 43 months, the child was diagnosed as t-AMKL.Results:After the diagnosis of ALL, the child was given chemotherapy with standard childhood ALL regimen. After 43 months, t-AMKL was diagnosed by comprehensive morphology, cytogenetics, and molecular biology. Bone marrow morphology showed that the proportion of primitive cells was 0.44; flow cytometry showed the phenotype was abnormal myeloid primitive cells; the pathology result showed that the abnormal cells weakly expressed CD42b and CD61; the electron microscopy showed platelet peroxidase (PPO)-positive and myeloperoxidase (MPO)-negative; the bone marrow immunohistochemistry showed the positive rate of CD41 was 34%; the child had a complex karyotype. After reviewing his medical history, he was diagnosed as t-AMKL.Conclusion:The t-AMKL is relatively rare, and it is helpful to improve the prognosis of patients by completing the relevant examinations for early diagnosis.

Objective: To enrich the gene mutation sites and accumulate treatment experience of congenital dyserythropoietic anemia (CDA) type Ⅱ by reporting one case of CDA patient with new mutation site of SEC23B and was successfully treated by homozygous allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: The mutation within SEC23B gene in a child case with the reduced hemoglobin for more than 3 months, and his family were analyzed in combination with literatures review. Results: A 3-day 5-month female child was admitted due to "decreasing hemoglobin for more than 3 months" , blood routine test showed HGB 44 g/L, positive for acid hemolysis test (Ham test) . Bone marrow showed that the proportion of erythroid line was 69%, mainly middle and late juvenile erythrocytes, binuclear and odd nucleated erythrocytes could be observed, and nuclear fragmentation and nuclear budding could be seen occasionally in nucleated erythrocytes, transmission electron microscopy disclosed that bone marrow harbored the typical double-layer membrane structure of nuclear erythrocytes. There were two unreported new mutation sites in the SEC23B gene, including 1504 G>C/wt and c. 2254-2255 insert A/wt. The two mutations were derived from the father and mother of the child respectively. At the late stage, the child was successfully treated with allo-HSCT, the original mutation turned negative. Conclusion This study reported the mutation type of SEC23B gene insertion for the first time in China. Allo-HSCT could be utilized as a treatment for CDA.

OBJECTIVETo clarify the role of endothelial cells (ECs) injury induced by anti-endothelial cell antibody (AECA) in allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODSSerum immunoglobulin (IgG) from allo-HSCT recipients were purified and incubated with human umbilical vein vascular endothelium (HUVEC) in vitro, then the functional changes and cell apoptosis were tested.

RESULTSAfter incubation with AECA positive IgG, soluble adhesion molecules significantly elevated in culture supernatant. When concentration of IgG was 160, 320, and 640 μg/ml, concentrations of soluble intercellular adhesion molecule-1 in supernatant were statistically higher in AECA positive groups [(117.10 ± 12.82) vs (78.17 ± 4.90) pg/ml, (151.30 ± 15.35) vs (89.46 ± 6.02) pg/ml, (239.00 ± 32.53) vs (127.80 ± 13.86) pg/ml, P<0.01)]. When concentration of IgG was 40, 80, 160, 320, and 640 μg/ml, concentrations of soluble vascular cell adhesion molecule-1 in supernatant were also statistically higher in AECA positive groups [(38.51 ± 3.76) vs (24.78 ± 2.59) pg/ml, (61.34 ± 6.99) vs (38.20 ± 3.17) pg/ml, (135.60 ± 24.46) vs (63.73 ± 5.08) pg/ml, (221.30 ± 29.40) vs (112.80 ± 8.91) pg/ml, (420.90 ± 31.70) vs (224.40 ± 20.79) pg/ml, P<0.01]. Clotting activity factors also elevated in culture supernatant after incubation with AECA positive IgG. When concentration of IgG was 80, 160, 320, and 640 μg/ml, concentrations of von Willebrand factor were statistically higher in AECA positive groups [(19.51 ± 0.72) vs (17.17 ± 0.60) ng/ml, P=0.0193; (22.97 ± 1.18) vs (18.27 ± 0.61) ng/ml, (26.40 ± 1.54) vs (19.53 ± 0.70) ng/ml, (34.35 ± 1.60) vs (23.81 ± 0.92) ng/ml, P<0.01]. When concentration of IgG was 320 and 640 μg/ml, concentrations of thrombomodulin were statistically higher in AECA positive groups [(57.50 ± 4.50) vs (40.31 ± 4.39) pg/ml, P=0.0132; (59.18 ± 4.11) vs (38.84 ± 5.16) pg/ml, P<0.01]. However, inflammatory factors (IL-1β, IL-6, IL-8 and ANG2) were not statistically different in AECA positive and negative groups (P>0.05). Moreover, IgG from AECA positive samples did not change the proliferation or cell apoptosis.

CONCLUSIONAECA from allo-HSCT recipients dysregulates ECs' function in vitro, but do not induce apoptosis, which is valuable in the pathophysiology of graft-versus-host disease (GVHD) and other complications after allo-HSCT.

Allografts ; Autoantibodies ; Endothelial Cells ; Endothelium, Vascular ; Graft vs Host Disease ; Hematopoietic Stem Cell Transplantation ; Humans ; Intercellular Adhesion Molecule-1 ; Interleukin-6 ; Umbilical Veins ; von Willebrand Factor