Guan J

Autophagy level of bone marrow mononuclear cells in patients with myelodysplastic syndromes

目的 研究骨髓增生异常综合征（MDS）患者骨髓单个核细胞（BMMNC）自噬水平的变化，探讨细胞自噬在MDS中的作用。 方法 以38例MDS患者为实验组，以26例巨幼细胞贫血患者为对照组，抽取骨髓并分离BMMNC。应用透射电镜观察自噬情况；采用单丹（磺）酰戊二胺（MDC）染色法检测自噬泡水平；采用RT-PCR、免疫荧光技术及蛋白免疫印迹法检测微管相关蛋白轻链3（LC3）、Beclin1 mRNA及蛋白的表达水平。 结果 MDS患者BMMNC内易见自噬泡；MDC染色显示MDS患者BMMNC含自噬泡细胞数量显著高于对照组[（9.75±2.63）%对（2.90±0.89）%，P<0.05]；MDS患者BMMNC LC3阳性细胞比例显著高于对照组[（6.13±1.03）%对（1.50±0.58）%，P<0.05]。低危/中危-1 MDS患者BMMNC Beclin1及LC3A mRNA表达水平显著高于对照组（3.61±3.02对1.55±1.03，P<0.05；6.56±3.97对1.21±0.95，P<0.05）；低危/中危-1 MDS患者BMMNC自噬负性调控基因-哺乳动物雷帕霉素靶点（mTOR）mRNA水平显著低于对照组（0.39±0.37对1.50±1.03，P<0.05）；中危-2/高危MDS患者BMMNC Beclin1、LC3和mTOR mRNA表达水平与对照组比较差异均无统计学意义（P值均>0.05）。蛋白免疫印迹法显示低危/中危-1患者BMMNC Beclin1蛋白表达（1.257±0.197）高于对照组（0.528±0.086）及中危-2/高危（0.622±0.118），差异均有统计学意义（P<0.05）。中危-2/高危组和对照组比较差异无统计学意义（P>0.05）。 结论 低危/中危-1 MDS患者BMMNC自噬水平升高，中危-2/高危MDS组患者BMMNC自噬水平无明显改变，自噬对MDS患者可能起保护性作用，自噬水平相对不足可能与MDS的进展有关。OBJECTIVE To investigate the change of autophagy level of bone marrow mononuclear cells（BMMNCs）in patients with myelodysplastic syndromes（MDS）. METHODS Thirty- eight patients with MDS and 26 megaloblastic anemia patients were enrolled in this study. The autophagic vacuoles were observed by transmission electron microscopy （TEM） and the quantity of autophagic vacuoles was detected by monodansylcadaverine （MDC） staining. The LC3 protein positive cells were counted by immunofluorescence assays. The expression of Beclin 1, LC3A, mTOR mRNA were measured by real time PCR. The expression of Beclin 1 proteins were detected by Western blotting. RESULTS The autophgic vacuoles of double membrane that surrounds lysosomes appeared in MDS patients. The percentage of MDC positive cells was significantly higher in MDS patients［（9.75±2.63）%］than that of controls［（2.90± 0.89）%, P＜0.05）. The percentage of LC3 protein cells was also increased in MDS patients（6.13±1.03）% vs（1.5±0.58）%, P＜0.05）. The expression of Beclin 1 and LC3A mRNA in low-risk and intermediate-1 MDS were higher compared with controls （3.61 ± 3.02 vs 1.55 ± 1.03 and 6.56 ± 3.97 vs 1.21 ± 0.95 respectively, both P＜0.05）. The expression of mTOR mRNA was down- regulated in low- risk and intermediate-1 MDS compared with controls（0.39±0.37 vs 1.50±1.03, P＜0.05）. There were no significant difference in expression of Beclin 1, LC3 and mTOR mRNA among intermediate-2 and high-risk MDS and controls. Beclin 1 protein expression was higher in low- risk and intermediate- 1 MDS patients（1.257 ± 0.197）than that of controls（0.528±0.086）and inermediate-2 and high-risk MDS patients（0.622±0.118）. CONCLUSION The autophagy levels were increased in low- risk and intermediate- 1 MDS, while not enhanced in intermediate-2 MDS. Autophagy might be considered as a cell protective mechanism in MDS. The relatively defective autophagy in intermediate- 2 and high- risk MDS might contribute to diseases progression.

[Study on C5b-9 deposited on the membrane of platelets and its dysfunction in patients with paroxysmal nocturnal hemoglobinuria].

目的 通过检测阵发性睡眠性血红蛋白尿症（PNH）伴或不伴再生障碍性贫血（AA）患者血小板膜补体复合物（C5b-9）、血小板活化分子（CD62p）表达及血清可溶性C5b-9(sC5b-9）水平探究PNH血栓形成的病理机制。 方法 用ELISA方法检测25例PNH/PNH-AA患者血清sC5b-9、补体C3和C4水平，并以30名健康志愿者作为正常对照；采用流式细胞术检测PNH/PNH-AA患者与正常人血小板PNH克隆数（CD59−CD61+/CD61+）、血小板膜C5b-9沉积率（C5b-9+CD61+/CD61+）以及血小板活化标志分子CD62p表达率（CD62p+CD61+/CD61+），并进行相关性分析。 结果 ①PNH/PNH-AA组患者血清sC5b-9水平为390.27（265.73~676.87）µg/L，显著低于正常对照组的540.39（344.20~1 576.78）µg/L（P<0.01）。②PNH/PNH-AA组患者血小板PNH克隆数[50.58（23.29~81.60）%]显著高于正常对照组[23.57（15.58~29.02）%]（P<0.01）；PNH/PNH-AA组患者PNH克隆血小板膜C5b-9沉积率[（17.53± 6.27）%]与患者正常血小板[（11.33±5.03）%]及正常对照组血小板[（10.88±3.58）%]相比均显著增高（P<0.01）。③PNH/PNH-AA组患者PNH克隆血小板CD62p表达率[（61.98±11.71）%]与患者正常血小板[（43.76±11.30）%]及正常对照组血小板[（38.23±8.07）%]相比均显著升高（P<0.01）；PNH/PNH-AA组患者正常血小板膜CD62p表达率比正常对照组血小板显著增高（P<0.05）。④血小板膜C5b-9沉积率与CD62p表达率呈显著正相关（r=0.449，P=0.002）。 结论 PNH/PNH-AA患者血小板锚连蛋白（CD59）缺失导致补体复合物C5b-9沉积于异常血小板膜并使其激活，这一过程可能参与PNH血栓的形成。OBJECTIVE To explore the expression levels of terminal complement complex (C5b-9) and CD62p on platelets and the soluble C5b-9 (sC5b-9) level in serum in patients with PNH or PNH-aplastic anemia (AA). METHODS Serum levels of sC5b-9, complement C3 and C4 were detected by using ELISA in 25 patients with PNH/PNH-AA. The quantities of C5b-9 and CD62p on the membrane of platelets were detected by flow cytometry. RESULTS ①In PNH/PNH-AA group, the serum sC5b-9 level [390.27(265.73-676.87) μg/L] was lower than that in control group [540.39(344.20-1 576.78) μg/L] (P<0.01). ②The platelet PNH clone (CD59⁻CD61⁺/CD61⁺) size [50.58(23.29-81.60)%] was bigger in the PNH/PNH-AA group than that [23.57(15.58-29.02)%] in control group (P<0.01). The percentages of C5b-9 deposition (C5b-9⁺CD61⁺/CD61⁺) were higher on the PNH clone platelets (CD59⁻CD61⁺) in the PNH/PNH-AA group [(17.53 ± 6.27)%] than those on the normal platelets (CD59⁺CD61⁺) in PNH patients 11.33±5.03）%］ and control [(10.88±3.58)%] group (P<0.01). ③ The expression of CD62p (CD62p⁺CD61⁺/CD61⁺) on PNH clone platelets in PNH patients [(61.98 ± 11.71)%] was higher than that on the normal platelets in PNH patients [(43.76±11.30)%] and control group [(38.23±18.07)%] (P<0.01). In addition, the expression of CD62p on normal platelets was higher in PNH patients than control (P<0.05). ④The deposition of C5b-9 positively correlated with the expression of CD62p on the platelets (r=0.559, P=0.002). CONCLUSION Deficiency of CD59 antigen on platelets in PNH patients may lead to the deposition of C5b-9 on its membrane and its dysfunction, which may contribute to thrombosis events in PNH.

[Telomere length of peripheral lymphocytes in patients with immuno-related pancytopenia].

OBJECTIVE To investigate the changes of relative telomere length (RTL) of peripheral blood (PB) CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺T lymphocytes, CD19⁺B lymphocytes and bone marrow (BM) CD34⁺ cells and its association with disease severity in untreated patients with immuno-related pancytopenia (IRP). METHODS The PB CD3⁺ , CD3⁺ CD4⁺ , CD3⁺ CD8⁺ T lymphocytes, CD19⁺ B lymphocytes, and BM CD34⁺ cells were purified by magnetic activated cell sorting (MACS), and RTL were measured with flow-fluorescence in situ hybridization (FLOW-FISH). RESULTS The RTL of CD3⁺, CD3⁺CD4⁺ , and CD3⁺CD8⁺T lymphocytes in untreated IRP patients were (27.754 ± 16.323)%, (7.526 ± 3.745)% and (25.854 ± 14.789)%, respectivly, which were significantly shorter than those in healthy-controls (54.555 ± 19.782)%, (12.096 ± 2.805)%, and (38.367 ± 4.626)% (P<0.05). The RTL of CD19⁺ lymphocytes in untreated IRP patients was (22.136 ± 16.142)%, which was significantly shorter than that in healthy controls (42.846 ± 16.353)% (P<0.01). There was no significant difference of BM CD34⁺ cells RTL between the untreated IRP patients (22.528 ± 21.601)% and the healthy controls (23.936 ± 19.822)% (P>0.05). There were significantly positive correlations between the RTL of B lymphocytes and the count of white blood cell (r=0.706, P=0.015). There were negative correlations between RTL of B lymphocytes and the clinical symptoms (r=-0.613, P=0.045) and positive correlations with therapeutic effect (r=0.775, P=0.005). CONCLUSION The shorter RTL of CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺, CD19⁺ lymphocytes, and the normal RTL of BM CD34⁺ cells in untreated IRP patients were identified, which might imply that IRP is a type of acquired autoimmune diseases.

Abnormal WT1 gene expression in paroxysmal nocturnal hemoglobinuria

OBJECTIVE To explore the pathogenesis of abnormal WT1 expression in paroxysmal nocturnal hemoglobinuria (PNH). METHODS The expression of WT1 mRNA in CD59⁻ and CD59⁺ bone marrow mononuclear cells (BMMNC) were measured by semi-quantitative reverse transcription PCR. After WT1 gene silence by RNA interference (RNAi) technology, biological characteristics of BMMNC were investigated by flow cytometry. RESULTS The relative expression of WT1 mRNA in PNH CD59⁻ BMMNC (1.06 ± 0.12) was significantly higher than that in PNH CD59⁺ BMMNC (0.90 ± 0.12) and normal BMMNC (0.86 ± 0.05, P<0.05), but there was no significant difference between PNH CD59⁺ BMMNC and normal BMMNC (P>0.05). WT1 mRNA expression in PNH was positively correlated with the proportion of CD59⁻ cells (r²=0.490, P=0.016), but had no relationship with the proportion of CD59⁺ cells. After WT1 gene silence by siRNA in PNH CD59⁻ BMMNC, WT1 mRNA expression was decreased. The proportions of G0/G1 phase in PNH CD59⁻ cell blank control group and siRNA-scr transfected group were (92.73 ± 3.71)% and (93.06 ± 4.14)%, and the proportions of S phase were (6.99 ± 3.61)% and (6.73 ± 4.08)%, respectively. The proportions of G0/G1 and S phase in siRNA-WT1 transfected group was (94.46 ± 3.71)% and (5.40 ± 3.55)%, respectively. There were significant differences in the proportions of G0/G1 phase and S phase among the controls, siRNA-WT1 transfected group and siRNA-scr transfected group (P<0.05). The rate of apoptosis in siRNA-WT1 transfected group [(35.91 ± 22.36)%] was significantly higher than those in controls [(26.12 ± 17.10)%] and siRNA-scr transfected group [(27.39 ± 18.99)%] (P<0.05). CONCLUSION siRNA-WT1 could effectively suppress the WT1 gene expression of CD59⁻ clone in PNH patients, inhibit its proliferation, and promote its apoptosis. WT1 gene expression might contribute to PNH clone proliferation.

[Memory B (CD5⁺ CD19⁺ CD27⁺) lymphocyte in patients with immune-related pancytopenia].

OBJECTIVE To detect memory B lymphocyte (Bm) in peripheral blood (PB) of immune-related pancytopenia (IRP). METHODS 86 patients with IRP and 11 health volunteers were enrolled in this study. Bm (CD5⁺ CD19⁺ CD27⁺) and bone marrow mononucleated cell antibodies (BMMNC-Ab) were determined via fluorescence-activated cell sorting, and clinical outcomes of these patients were analyzed. RESULTS (1)43 initial patients achieved obvious remission in all 52 initial cases after conventional immunosuppression therapy. 16 relapsed patients with IRP received Rituximab (RTX) and 14 cases achieved obvious remission, among which 7 cases were refractory to conventional immunosuppression therapy, 5 cases exhibited obvious remission, and 2 cases did not respond. Other 18 relapsed cases received conventional immunosuppression therapy and 13 cases achieved obvious remission. (1)The level of Bm in PB in 52 initial patients with IRP was(1.81 ± 0.97)%, and no significant difference was observed between the initial patients and health volunteers (1.75 ± 0.55)% (P>0.05). The level of Bm in PB in 34 relapsed patients with IRP was obviously higher than that in the initial IRP patients and health volunteers (P<0.05). Significant difference was observed in the level of Bm in PB in 16 relapsed IRP patients between pre-therapy and post-therapy with RTX (P<0.05). No statistical difference was found between the remission and no-response groups in relapsed patients treated with RTX. RTX regimen produced more effective outcome than conventional immunosuppression therapy, which better eliminated Bm than the latter (P<0.05). Initial patients with IRP who relapsed within a two-year follow-up period had a lower level of Bm in PB compared with un-relapsed patients (P<0.05). Majority of BMMNC- Ab antibodies in relapsed patients were IgG (82.4%) and IgM (69.2%) autoantibodies in patients with initial IRP. CONCLUSION The level of Bm in PB was associated with relapsed patients with IRP. Bm did not respond to conventional immunosuppression therapy,but responded to RTX.

Effect of CCL3 on osteoblast in myeloma bone disease

OBJECTIVE To culture osteoblast in vitro and evaluate CCL3 receptor CCR1 expression in patients with multiple myeloma (MM). METHODS Bone marrow osteoblasts from MM patients were cultured in vitro with dexamethasone, β-sodium glycerophosphate and vitamin C, which were identified by alkaline phosphatase staining, Von Kossas staining. The CCL3 receptor expression was evaluated by flow cytometry. The morphology and quantity of osteoblast were observed after exposure to CCL3. RESULTS Bone marrow osteoblasts from MM patients could be cultured in vitro and be identified by positive staining of alkaline phosphatase and Von Kossas. MM-derived osteoblasts expressed higher levels of CCR1 (74.48 ± 7.31)%, compared with normal controls (48.35 ± 8.81)%. Calcium deposition of osteoblasts after exposure to CCL3 was less than that of controls. CONCLUSION Bone marrow osteoblasts could be cultured in vitro from MM Patients. CCL3 may contribute to the development of myeloma bone disease.

[Preliminary study on the quantity and function of T follicular helper cells in the cytopenic patients with positive BMMNC-Coombs test].

OBJECTIVE To study the quantity and function of bone marrow (BM) T follicular helper (Tfh) cells of the cytopenia patients with positive bone marrow mononuclear cells (BMMNC)- Coombs test (also known as immuno-related pancytopenia, IRP), and explore the role of Tfh cells in the pathogenesis of IRP. METHODS Forty- three untreated IRP patients, 47 recovered IRP patients and 25 healthy donors were enrolled in this study. The percentages of Tfh cells, Tfh-related molecules ICOS, CD40L, IL-21 and Bcl-6 in BM were investigated by flow cytometry and semiquantitive RT-PCR. RESULTS The ratio of CD4⁺CXCR5⁺/CD4⁺ cells of untreated IRP patients [(28.79 ± 19.70)%] was significantly higher than that of recovered IRP patients [(21.15 ± 12.81)% ] and normal controls ([ 13.42 ± 6.72)% ](P<0.05). The ratio of CD4⁺CXCR5⁺ICOS⁺/CD4⁺CXCR5⁺ cells of untreated IRP patients [(5.05 ± 4.71)% ] was significantly higher than that of recovered IRP patients [(2.96 ± 2.89)% ] and normal controls [(2.99 ± 2.23)% ] (P<0.05). The ratio of CD4⁺CXCR5⁺CD40L⁺/CD4⁺CXCR5⁺ cells of untreated IRP patients [(5.87 ± 4.14)%] and recovered IRP patients [(6.52±5.47)%] were significantly higher than that of normal controls [(2.93 ± 2.92)%] (P<0.05). The ratio of intracytoplasmic CD4⁺CXCR5⁺IL-21⁺/CD4⁺CXCR5⁺ cells of untreated IRP patients [(8.20 ± 7.41)% ] and recovered IRP patients [(6.30 ± 6.03)% ] were significantly higher than that of normal controls [(3.43 ± 3.40)%] (P<0.05). The relative expressions of Bcl-6 mRNA in BMMNC were 0.625 ± 0.248, 0.485 ± 0.253, 0.306 ± 0.210 in three groups, respectively. The differences between untreated IRP patients, recovered IRP patients and normal controls were significant (P<0.05). CONCLUSION There exists increased quantity and hyperfunction of Tfh cells in the IRP patients, they may play important role in the pathogenesis of IRP. Tfh cells and their related effector molecules could be a potential therapeutic target for the disease.

[The mechanisms underlying bone marrow damage by iron overload in pancytopenic patients with positive BMMNC-Coombs test].

OBJECTIVE To investigate the mechanisms underlying bone marrow damage by iron overload in pancytopenic patients with positive BMMNC-Coombs test (IRP). METHODS Twenty-one iron overloading, 26 non-iron overloading IRP patients and 10 normal controls were enrolled in this study. The expressions of ROS, Bcl-2, Caspase-3 and apoptosis of BMMNC were analyzed by flow cytometry (FCM). Antioxidants were added to iron overloading IRP BMMNC, and then the changes of indices above were detected by FCM. The number and apoptosis of T lymphocytes of IRP patients were also detected. RESULTS ROS and apoptosis of BMMNC, myelocytes, erythrocytes and stem cells of iron overloading IRP patients were significantly higher than that of non-iron overloading IRP ones and normal controls (P < 0.05). The expressions of Bcl-2 on BMMNC, erythrocytes and stem cells of iron overloading IRP patients were significantly lower than those of non-iron overloading IRP ones (P < 0.05). The levels of Caspase-3 on myelocytes, erythrocytes and stem cells of iron overloading IRP patients were significantly higher than those of non-iron overloading IRP ones and normal controls (P < 0.05). After treatment with antioxidants, the expressions of ROS, Caspase-3 and apoptosis of iron overloading IRP BMMNC significantly decreased, but opposite for Bcl-2. The percentages of CD4(+) lymphocytes [ ( 40.86 ± 8.74）%] and CD4(+)/CD8(+) (1.44 ± 0.36) in PB of iron overloading IRP patients were significantly higher than that of non-iron overloading IRP ones [(35.96 ± 7.03)% and 1.14 ± 0.37] and normal controls [(28.00 ± 6.73)% and 0.79 ± 0.21], respectively (P < 0.05), as opposite for CD8(+) lymphocytes (P < 0.05). The apoptosis of CD8(+) lymphocytes [(27.35 ± 10.76)%] and the ratio of CD8(+) apoptosis/CD4(+) apoptosis (2.51 ± 0.81) in BM of iron overloading IRP patients were significantly higher than those of non-iron overloading IRP ones [(15.47 ± 8.99)%] and normal controls (1.39 ± 0.47), respectively (P < 0.05). The apoptosis of erythrocytes and stem cells coated with auto-antibodies in BM of iron overloading IRP patients were significantly higher than those of non-iron overloading IRP and normal controls. CONCLUSION Mechanisms underlying bone marrow damage by iron overload might be through the follows: ①The increased ROS induced by excessive iron deposition affected the expressions of Caspase-3 and Bcl-2, which caused more BMMNC apoptosis; ②The abnormal number and ratio of T lymphocytes caused by iron overload aggravated the abnormality of immunity of IRP; ③Iron overload may increase the damage to erythrocytes and stem cells coated with auto-antibodies.