The RAS-signaling-pathway-mutation-related prognosis in B-cell acute lymphoblastic leukemia: A report from South China children's leukemia group.

The next-generation sequencing technologies application discovers novel genetic alterations frequently in pediatric acute lymphoblastic leukemia (ALL). RAS signaling pathway mutations at the time of relapse ALL frequently appear as small subclones at the time of onset, which are considered as the drivers in ALL relapse. Whether subclones alterations in the RAS signaling pathway should be considered for risk group stratification of ALL treatment is not decided yet. In this work, we investigate the RAS signaling pathway mutation spectrum and the related prognosis in pediatric ALL. We employed an NGS panel comprising 220 genes. NGS results were collected from 202 pediatric ALL patients. 155 patients (76.7%) harbored at least one mutation. The incidences of RAS signaling pathway mutations are different significantly between T-ALL and B-ALL. In B-ALL, the RAS pathway is mostly involved, and NRAS (17.6%), KRAS (22.7%), and PTPN11 (7.7%) were the three most frequently mutated genes. Co-occurring mutations of CREBBP and NRAS, FLT3, or PTPN11 (p = 0.002, p = 0.009, and p = 0.003, respectively) were found in this cohort. The 3-year RFS rates for the RAS signaling pathway mutation-positive and negative cases was 76.5 % versus 89.7 % (p = 0.012). Four cases relapsed in the lately 3 years were RAS signaling pathway mutation-positive. RAS signaling pathway mutation is an important biomarker for poorer relapse-free survival in pediatric B-ALL patients despite good early MRD levels.

[Relationship between MTHFR Gene Polymorphism(C677T) and Adverse Reactions of High-Dose Methotrexate in Pediatric Patients with Acute Lymphoblastic Leukemia].

OBJECTIVE: To explore the effects of methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism on the adverse reactions of high-dose methotrexate (MTX) in pediatric patients with acute lymphoblastic leukemia (ALL). METHODS: A total of 69 children with ALL admitted to the department of Pediatrics of Sun Yat-sen Memorial Hospital of Sun Yat-sen University from November 2018 to October 2020 were included in this study. The clinical data of the children were collected, leukocytes were isolated from their peripheral blood, and MTHFR genotyping was performed by digital fluorescence molecular hybridization techniques. The adverse reactions and plasma drug concentration of MTX were monitored during the chemotherapy. Moreover, the effect of MTHFR gene polymorphism on MTX adverse reactions and plasma drug concentration were analyzed. RESULTS: Among the middle and high risk children, compared with the wildtype group (CC genotype), patients with MTHFR C677T mutations (CT+TT genotypes) had a higher risk of leukopenia (OR=2.38), neutropenia (OR=2.2), anemia (OR=1.83) and hepatoxicity (OR=1.98). However, no significant difference was found in the MTX plasma concentration between the MTHFR C677T mutantion group and the wildtype group at different timepoints (24 h, 48 h and 72 h). Multivariate analysis revealed that the plasma concentration of MTX (48 h), clinical risk level of ALL and MTHFR C677T gene polymorphism were independent factors for the adverse reactions of high-dose MTX. CONCLUSION: The MTHFR C677T mutations may be associated with myelosuppression and hepatotoxicity in children with ALL after high-dose MTX treatment.

Analysis of clinical characteristics and prognostic factors associated with EBV-associated HLH in children.

Purpose Our aim is to analyze the clinical characteristics and prognostic factors of Epstein-Barr (EB) virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) in children. Methods Children with newly diagnosed HLH were retrospectively analyzed. Results Finally, a total of 95 children with HLH were enrolled in this study, including 43 (45.3%) with EBV-HLH and 52 (54.7%) with non-EBV-HLH. Laboratory tests showed that the levels of absolute neutrophil count (ANC) decrease (P = 0.031) and triglycerides (TG) increase (P = 0.036) in the EBV-HLH group were statistically significant compared with those in the non-EBV-HLH group, respectively. We found that the remission rate during induction period in the EBV-HLH group and non-EBV-HLH group was 75.8% and 89.3%, respectively. The correlation analysis showed that the elevated degree of total bilirubin (TBIL) (P = 0.042), triglyceride (TG) (P = 0.009), serum ferritin (SF) (P = 0.008) and interleukin-8 (IL-8) (P = 0.004) were related with the remission rate during induction in the EBV-HLH group. Further univariate analysis showed that the elevated degree of TBIL (P = 0.048) and TG (P = 0.019) were significant risk factors for the remission rate during induction in the EBV-HLH group. In the multivariate analysis, we observed that there was statistical significance for the degree of TG elevation (P = 0.015) between the two groups. The correlation analysis showed that the elevated degree of TBIL (P = 0.030), the elevated degree of SF (P = 0.020) and the elevated degree of interleukin-6 (P = 0.010) were related to the induction mortality of children with EBV-HLH. Conclusion TBIL and TG are valid indicators to assess the efficacy and prognosis of EVBHLH among children in induction period.

[Clinical Characteristic, Diagnosis and Treatment of Acute Lymphoblastic Leukemia Combined with Pneumocystis Carinii Pneumonia in Children].

OBJECTIVE: To investigate the clinical characteristics and treatment of pneumocystis carinii pneumonia (PCP) in children with acute lymphoblastic leukemia (ALL), in order to improve the early diagnosis and effective treatment. METHODS: Clinical data of five children with ALL developing PCP in the post-chemotherapy granulocyte deficiency phase were analyzed retrospectively. The clinical manifestations, laboratory tests, imaging findings, treatment methods and effect were summarized. RESULTS: The male-to-female ratio of the five children was 1∶4, and the median age was 5.5 (2.9-8) years old. All patients developed PCP during granulocyte deficiency phase after induction remission chemotherapy. The clinical manifestations were generally non-specific, including high fever, tachypnea, dyspnea, non-severe cough, and rare rales in two lungs (wet rales in two patients). Laboratory tests showed elevated C-reactive protein (CRP), serum procalcitonin (PCT), (1,3)-ß-D-glucan (BDG), lactate dehydrogenase (LDH) and inflammatory factors including IL-2R, IL-6 and IL-8. Chest CT showed diffuse bilateral infiltrates with patchy hyperdense shadows. Pneumocystis carinii(PC) was detected in bronchoalveolar lavage fluid (BALF) or induced sputum by high-throughput sequencing in all patients. When PCP was suspected, chemotherapy was discontinued immediately, treatment of trimethoprim-sulfame thoxazole (TMP-SMX) combined with caspofungin against PC was started, and adjunctive methylprednisolone was used. Meanwhile, granulocyte-stimulating factor and gammaglobulin were given as the supportive treatment. All patients were transferred to PICU receiving mechanical ventilation due to respiratory distress during treatment. Four children were cured and one died. CONCLUSION: PCP should be highly suspected in ALL children with high fever, dyspnea, increased LDH and BDG, and diffuse patchy hyperdense shadow or solid changes in lung CT. The pathogen detection of respiratory specimens should be improved as soon as possible. TMP/SMZ is the first-line drug against PCP, and the combination of Caspofungin and TMP/SMZ treatment for NH-PCP may have a better efficacy. Patients with moderate and severe NH-PCP may benefit from glucocorticoid.

Evaluation of Poly(ADP-ribose) Polymerase Inhibitor, Pamiparib (BGB-290) in Treating Acute Myeloid Leukemia and the Characterization of Its Nanocarrier.

Despite the continuous improvement of leukemia treatment in the clinic, the overall 5-year disease-free survival of acute myeloid leukemia (AML) is only approximately 30%-60% due to relapse and the refractoriness of AML after traditional chemotherapy. Inhibition of poly(ADP-ribose) polymerase (PARP), a member of the DNA damage repair complex, has a strong antitumor effect in solid tumors. However, the role of PARP in AML remains unclear. We found that high levels of PARP1 and PARP2 were positively related to chemotherapy resistance and poor prognosis in patients with AML. Doxorubicin (DOX)-resistant AML cells highly expressed PAPR1 and PARP2. Knockdown of PARP1 and PARP2, or pharmaceutical inhibition of PARP by the PARP inhibitor (PARPi) BGB-290, significantly enhanced the cytotoxicity of DOX in AML cells due to increased DNA damage. PLGA-loading BGB-290 was properly self-assembled into stable BGB-290@PLGA nanoparticles (NPs), which is uniform particle size and good stability. BGB-290@PLGA is easily uptake by AML cell lines and stays for a long time. Combined with DOX, BGB-290@PLGA can significantly improve the chemosensitivity of AML cell lines. Furthermore, BGB-290 and DOX combination treatment dramatically repressed the onset of leukemia and prolonged the survival of THP-1 xenografted mice. Overall, this study demonstrated that PARPi with traditional chemotherapy could be an efficient therapeutic strategy for AML.

Clinical Outcome of Acquired Post-Immunosuppressive-Therapy Aplastic Anemia in Pediatric Patients: A 13-Year Experience in Two Southern China Tertiary Care Centers.

OBJECTIVE: The aim of the present study is to evaluate the efficacy, complications, and contributing factors of immunosuppressive therapy (IST) response in children with acquired aplastic anemia (AA) and to explore optimal therapeutic methods for different clinical AA types. METHODS: A total of 130 children diagnosed with acquired AA underwent IST in the Department of Pediatrics at Sun Yat-sen Memorial Hospital and the Department of Pediatrics at Seventh Affiliated Hospital, Sun Yat-sen University, between January 1, 2006, and July 15, 2020. The overall survival (OS), response rates, complications, and response predictors were analyzed. The response rates were compared according to clinical AA type. RESULTS: All 130 children with AA were followed up with for a median of 50.6 months. Among the patients, 25 had non-severe AA (NSAA), 64 had severe AA (SAA), and 41 had very severe AA (VSAA). All patients initially received IST. In 13 patients, the IST failed; these patients received an allo-hematopoietic stem cell transplant as a salvage regimen. The OS rate was 90.3% ± 2.8%, and the response rates at 3, 6, 9, and 12 months were 34.19%, 39.32%, 49.57%, and 66.67%, respectively. The prolonged follow-up period might have led to higher response rates, especially in patients with SAA and VSAA. A multivariate logistic regression analysis of prognostic factors was conducted; the results showed that high red blood cell (RBC) and platelet (PLT) counts were associated with a high overall response rate and that the RBC count at diagnosis is a major contributing factor. CONCLUSION: With the use of rabbit anti-thymocyte globulin, proper cyclosporine management, and a prolonged IST follow-up period, a higher number of patients with acquired AA than normal achieved response. Proportionally, the number of patients who achieved remission within 12 months was higher in the SAA group (38.18%→63.64%) and VSAA group (28.95%→65.79%) than in the NSAA group (58.33%→75%). Higher RBC and PLT counts at diagnosis can predict a favorable outcome.

[Analysis of Clinical Characteristics and Prognosis in Children with Acute Megakaryoblastic Leukemia without Down Syndrome].

OBJECTIVE: To analyze the clinical characteristics and treatment effects of children with acute megakaryoblastic leukemia without down syndrome (non-DS-AMKL). METHODS: The clinical data of 19 children with non-DS-AMKL treated in the Pediatric Hematology Ward in Sun Yat-sen Memorial Hospital of Sun Yat-sen University from May 2008 to April 2018 were analyzed retrospectively. The clinical characteristics, laboratory test and treatment methods of the children were concluded. All patients were followed up to evaluate the effect of treatment. RESULTS: The 19 cases of children included nine male and ten female, the median age of onset was 2 years old. The clinical manifestations showed nonspecific. The median white blood cell of peripheral blood was 15.88×109/L, the median hemoglobin was 67 g/L and median platelet was 16×109/L. An increase of primitive and naive megakaryocytes was found in the bone marrow sample. The immunophenotypes of bone marrow detected by flow cytometry in 19 children were all positive expressed for CD41, CD61. Genetic tests showed that five cases carrying EVI1, including one complicating with MLL/AF10, one patient carrying HOX11, one carrying GATA1, IKZF1 and DDX11 mutations, one patient carrying missense mutation of NRAS, one with missense mutation of KRAS and two cases with high expression of WT1. Karyotype analysis were performed in 11 cases of children, including four with normal karyotype, four with complex karyotypes, one with trisomy 8, one with 7/13 trisomy 21 without Down syndrome manifestations (considered as abnormal somatic karyotype) and one Robertsonian translocation carrier involving chromosomes 14 and 21. Ten children received treatment, including three cases with allogeneic hematopoietic stem cell transplantation (allo-HSCT) after complete remission (CR), two cases with complete donor implantation, and one without implanted but hematopoietic recovered, these three children were followed up for 26, 15 and 12 months respectively and the minimal residual disease (MRD) were all less than 10-4. Another three cases achieving CR after chemotherapy but relapsed in 5, 10 and 12 months after the onset respectively, and all the three children were died eventually. One children died of pulmonary hemorrhage during chemotherapy and three children died from discontinuation of treatment after non remission. The remaining nine children died because of without chemotherapy treatment. CONCLUSION: Non-DS-AMKL was rare in children and difficult to be diagnosed. Determination of MICM classification as early as possible was helpful for diagnosis, and genetic testing played an important role for diagnosis and prognosis evaluation. Early hematopoietic stem cell transplantation in patients with CR after chemotherapy might be an effective way to cure AMKL.

Protective Effect of a Bispecific Fc-Fusion Protein on the Barrier of Human Retinal Pigment Epithelial Cells.

INTRODUCTION: The aim of the study was to evaluate the protective effects of IBI302, a bispecific Fc-fusion protein that theoretically can bind vascular endothelial growth factor (VEGF), complement C3b, and C4b in the barrier of the cultured human retinal pigment epithelial (hRPE) cells. METHODS: Primary hRPE cells were isolated and cultured to monolayer barrier. hRPE monolayers were divided into the PBS control group, VEGF-Trap group, complement receptor 1 (CR1) group, and IBI302 group. Identification of hRPE cells, barrier function, inflammation factors, and immune response products was tested by immunofluorescent staining, transepithelial resistance (TER), and ELISA. RESULTS: IBI302 treatment significantly improved the TER of the barrier of hRPE cells after complement-activated oxidative stress compared with the PBS control group, VEGF-Trap group, and CR1 group. The maximum effect of IBI302 on protecting hRPE cell viability was observed at the concentration of 1 µg/mL. The elevated expression of VEGF, chemokine (C-C Motif) ligand 2, C3a, C5a, and membrane attack complex was reduced by IBI302. CONCLUSION: IBI302 could protect the barrier function of hRPE cells. IBI302 might be a potentially effective drug for the RPE barrier-associated ocular diseases.

Roles of regulatory T cells in the pathogenesis of pediatric aplastic anemia.

The pathogenesis of aplastic anemia (AA) in children is not clear. This study was conducted to investigate the changes in the proportion and function of regulatory T cells (Tregs) in pediatric AA. The proportion of Tregs, mRNA levels of transcription factors, and concentrations of cytokines were measured by flow cytometry, reverse transcription-PCR, and enzyme-linked immunosorbent assay, respectively. Tregs were co-cultured with effector T cells (Teff) to evaluate the function of Tregs. The proportion of Tregs after immunosuppressive therapy (IST) in pediatric AA was monitored dynamically. Compared to the control, the proportions of Tregs in peripheral blood and bone marrow lymphocytes of the untreated AA group were lower (1.31% ± 0.73% vs. 3.16% ± 0.92%, 1.49% ± 0.81% vs. 3.06% ± 0.82%, respectively, p < 0.001). The mRNA levels of FOXP3 and STAT3 in the AA group were lower (p = 0.014; p < 0.001). However, the mRNA levels of T-BET did not significantly differ between groups. The concentration of interferon-γ and interleukin-17 in the AA group were higher (p = 0.004; p = 0.003), whereas the concentration of TGF-ß decreased (p = 0.044). The immunosuppressive function of Tregs was impaired in the AA group. After IST, the proportion of Tregs was significantly lower than that in the control. The proportion of Tregs at the time of diagnosis in the nonresponsive group was lower than that in the responsive group, but the difference was not significant. Treg levels were significantly decreased and were functionally impaired at the time of diagnosis of pediatric AA. However, there was no significant change in Tregs at the resolution of AA.

Evaluation of Insulin-mediated Regulation of AKT Signaling in Childhood Acute Lymphoblastic Leukemia.

OBJECTIVE: Hyperglycemia increases the risk of early recurrence and high mortality in some adult blood cancers. In response to increased glucose levels, insulin is secreted, and several studies have shown that insulin-induced AKT signaling can regulate tumor cell proliferation and apoptosis. The AKT pathway is aberrantly activated in adult acute lymphoblastic leukemia (ALL), but the mechanisms underlying this activation and its impact in pediatric patients with ALL are unclear. MATERIALS AND METHODS: We evaluated the insulin-induced chemoresistance and AKT pathway activation by measuring cell proliferation, apoptosis, and other parameters in ALL cell lines (Jurkat and Reh cells), as well as in primary pediatric leukemic cell samples, after culture with insulin, the chemotherapeutic drugs daunorubicin (DNR), vincristine (VCR), and L-asparaginase (L-Asp), or anti-insulin-like growth factor-1 receptor (IGF-1R) monoclonal antibody. RESULTS: DNR, VCR, and L-Asp-induced toxicity in Jurkat and Reh cells was reduced in the presence of insulin. DNR promoted cell proliferation, whereas DNR, VCR, and L-Asp all reduced apoptosis in both cell lines cotreated with insulin compared with that in cell lines treated with chemotherapeutics alone (P<0.05). Furthermore, addition of an anti-IGF-1R monoclonal antibody promoted apoptosis, downregulated IGF-1R expression, and decreased the phosphorylation of AKT, P70S6K, and mTOR intracellular signaling pathway proteins in both cell lines, as well as in primary cultures (P<0.05). CONCLUSIONS: Our results suggest that insulin-induced chemoresistance and activation of the AKT signaling pathway in pediatric ALL cells.

[Clinical Charcteristics and Prognostic Analysis of 28 cases of Pediatric Myelodysplastic Syndrome].

OBJECTIVE: To analyze the clinical features and prognosis of 28 children with myelodysplastic syndrome (MDS) and to screen the high risk factors affecting the prognosis so as to provide the new ideas for standard of clinical diagnosis and therapy. METHODS: The clinical data of 28 children with newly diagnosed MDS treated in our hospital from March 1994 to July 2016 were analyzed retrospectively, the features of disease onset and the results of laboratory examination were summarized, all MDS children were followed up, the prognosis and the high risk factors affecting the prognosis were evaluated. RESULTS: In all 28 MDS children, the ratio of male to female was 1.8∶1, the incidence of MDS was observed in boys, while the low incidence of MDS was found in older children. The clinical manifestations were mainly the decrease of three series blood cells in 16 cases (57.14%), other cases presented simple anemia (7.1%), simple thrombocytopenia (7.1%), neutropenia with anemia (14.29%), and anemia with thrombocytopenia (14.28%).The bone marrow image showed mainly hyperplasia (82.14%), and the pathological hematopoiesis, moreover the manifistation of pathological hematopoiesis was different in forma and degree; the bone marrow biopsy showed the typical abnormal localization of immature precursor(ALIP) accepted for 33.33%; the chromosome karyotype detection showed the detected rate of chronosome abnormality was 41.18%. The median follow-up time was 1.75 years. 5 children with MDS received the hematopoietic stem cell transplantation (HSCT), among them 1 dead and 4 maintained CCR; Out of other 23 patients no-received HSCT, 7 cases given up treatment after confirmed diagnosis, 16 cases received the chemotherapy (2 cases given up treatment after CR, 5 cases transformed into AML, 3 cases relapsed, 3 cases maintained CCR), 11 cases dead, 9 cases failed to be followed up. The 5-years OS rate and EFS rate in all patients were predicted as (38.2±11.3)% and (35.3±11.3)%,respectively, among them, the OS and EFS rates of patients received the HSCT allo superior to those of patients did not received HSCT ï¼»(80.0±17.9）% vs.(22.8±11.5）%ï¼½ (P<0.05) and ï¼»(80.0±17.9)% vs (17.5±11.1)%ï¼½(P<0.05). Analysis showed that in addition to receiving the HSCT(P<0.05), platelet decrease in peripheral blood(P<0.01), the age, sex, existance of micromegakaryocytes in bone marrow and progressive MDS or no influenced not on the prognosis(P>0.05). CONCLUSION: The children MDS is rare and easy to be misdiagnosis, moreover displays more high heterogeneity and poor prognosis, thereby the early diagnosis is crucial, in addition, the system of prognosis evaluation is imperative to be perfected. The HSCT may be the effective method for curative treatment of childhood MDS.

IGF-1-Mediated Survival from Induced Death of Human Primary Cultured Retinal Pigment Epithelial Cells Is Mediated by an Akt-Dependent Signaling Pathway.

Degeneration of the human retinal pigmented epithelium (hRPE) is involved in several eye disorders such as age-related macular degeneration (AMD). In this study, we investigated the protective effect of IGF-1 on human primary cultured RPE cells and its underlying mechanism. IGF-1 dose- and time-dependently promoted the survival of RPE cells from serum deprivation. Western blot showed that IGF-1 stimulated the activation of the PI3K/Akt and MAPK pathways in hRPE. Inhibition of the PI3K/Akt pathway by the PI3K-specific inhibitor, LY294002 or inhibition of Akt by Akt-specific inhibitors Akt inhibitor VIII or SN-38, or downregulation Akt with siRNA specific for Akt blocked the effect of IGF-1 on hRPE. In contrast, blockade of the MAPK pathway with a specific inhibitor PD98059 had no effect. Interestingly, vitreous IGF-1 injection reversed the inhibitory effect of light exposure (a dry AMD model) on both a wave and b wave. Immunocytochemistry showed that vitreous IGF-1 injections promoted the survival of RPE cells in rat retina and the expression of RPE65 in RPE cells from light injury. These results indicate that IGF-1 is able to protect hRPE cell from different insults in vivo and in vitro. Further detailed studies may lead the way to a therapeutic intervention for retinal diseases in which cell death is an underlying contributory mechanism.

Forkhead box protein O3 suppresses uveal melanoma development by increasing the expression of Bcl­2­like protein 11 and cyclin­dependent kinase inhibitor 1B.

Forkhead box protein O3 (FoxO3a) is a forkhead box family transcription factor which serves an important role in a number of biological functions, including tumor growth. A previous study indicated that FoxO3a serves a role in insulin like growth factor­induced growth, migration and invasion of uveal melanoma (UM) cells; however, whether FoxO3a is associated with the development and formation of UM remains unknown. In the present study, the role of FoxO3a in UM development and formation was investigated by modulating the expression of FoxO3a in a human UM cell line. The results of the present study demonstrated that FoxO3a overexpression in UM cells inhibited cell proliferation and promoted cellular apoptosis, leading to an accumulation of cells at the G1 cell cycle phase. Western blot analysis demonstrated that FoxO3a overexpression increased the transcription and protein expression of Bcl­2­like protein 11 and cyclin­dependent kinase inhibitor 1B, and inhibited cyclin D1 transcription and expression. The opposite effects were observed when FoxO3a was knocked down in UM cells. The results of the present study indicated that FoxO3a may exhibit a negative role in UM development and formation, which is consistent with its role as a tumor suppressor.

Enhanced Depth SD-OCT Images Reveal Characteristic Choroidal Changes in Patients With Vogt-Koyanagi-Harada Disease.

BACKGROUND AND OBJECTIVE: To identify characteristic choroidal changes of patients with Vogt-Koyanagi-Harada (VKH) disease at different stages. PATIENTS AND METHODS: Fifty-four patients with VKH in the acute uveitic or convalescent stages, 24 patients with central serous chorioretinopathy (CSC), and 54 normal participants were enrolled in this prospective, observational study. Enhanced depth imaging spectral-domain optical coherence tomography scans were captured for all subjects to allow for comparison of choroidal morphological findings. RESULTS: Numerous round or oval hyperreflective profiles with hyporeflective cores, corresponding to choroidal vessels, were observed in the choroid of control participants and patients with CSC; whereas the numbers of these profiles were markedly decreased in the choroid of VKH patients in both the acute uveitic and convalescent stages. CONCLUSION: A reduction in vascular profiles in the choroid is observed in VKH and may aid in the differentiation with disorders such as CSC. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:1004-1012.].

Mitochondria-Targeted Antioxidant Peptide SS31 Protects Cultured Human Lens Epithelial Cells against Oxidative Stress.

PURPOSE: To investigate the effects of the mitochondria-targeted peptide, SS31, on cultured human lens epithelial cells (HLECs) under conditions of oxidative stress. METHODS: Optimal concentrations of SS31 were determined by MTT assay. HLEB-3 cells were first treated with SS31 for 2 h and then with 500 µM t-BHP for 6 h. Cell apoptosis was revealed by Annexin V/PI staining. Morphological changes in nuclei were observed by fluorescence microscopy after Hoechest 33258 fluorescent staining. Reactive oxygen species (ROS) were measured by MitoSOX staining. Changes in mitochondrial membrane potential (ΔΨm) were detected using the JC-1 fluorescent dye. Activation of p38 and c-Jun N-terminal kinases (JNKs) were quantified by Western Blot analysis. RESULTS: SS31 protected HLEB-3 cells against t-BHP-induced cell apoptosis, reduced ROS, maintained ΔΨms, and inhibited activation of JNK and p38 pathways. CONCLUSIONS: SS31 was able to protect HLEB-3 cells against oxidative damage and, thus, represents a potential new treatment modality for preventing the formation of cataracts and other age-related disorders.

[Comparison between two different dose of r-ATG combined with CsA for treating children with severe aplastic anemia].

This study was purposed to compare the efficacy and safety of two different doses of rabbit anti-thymocyte globulin (r-ATG) combined with cyclosporine (CsA) for treating children with severe aplastic anemia (SAA). From January 2005 to July 2010, a total of 95 children with SAA accepted intensive immunosuppressive therapy (IIST) in our department, out of them 55 cases were treated with r-ATG 2.5 mg/(kg·d) for 5 days in combination with CsA (group I) and other 40 cases were treated with r-ATG 3.5 mg/(kg·d) for 5 days in combination with CsA (group II). The responsive rate, adverse reactions, early mortality, relapse and clonal disease were analyzed retrospectively and results between the two groups were compared. Out of 95 patients 43 were boys and 52 were girls, their ages were from 1 to 16 years. The sex, age, severity and course of the disease were comparable between the two groups. The results showed that after treating for 3 and 6 months, the response of patients in group II was higher than that of patients in group I (50% vs 32.1%, P = 0.08 and 65% vs 45.3%, P = 0.059), at 9 and 12 months the response rate of patients in group II and group I did not show significant difference (70.0% vs 71.1%,P = 0.904 and 82.5% vs 80.8%,P = 0.832); at 12 months of treatment, the complete response rate of patients in group II was significantly higher than that of patients in group I (40.0% vs 23.1%,P = 0.08); at 3, 6, 9 months of treatment, the complete response rate of 2 groups showed no obvious difference. The incidence of serum disease, early infection and early mortality did not show statistical difference between two groups. There was no statistical difference in 2 year overall survival rate of two groups. In group I 39 patients were followed-up for more than 2 years, among them 3 patients relapsed, 1 patient died and 1 patient was diagnosed as acute monocytic leukemia (M5). In group II 15 patients were followed up for more than 2 years, there were no relapse, death and clonal disease. It is concluded that the r-ATG combined with CsA is an effective and safe therapeutic regimen for the SAA children. The effect of r-ATG 3.5 mg/(kg·d) is better than the 2.5 mg/(kg·d). The early safety is comparable between the two groups. However, the long-term effect, complications and survival rate need longer follow-up study to evaluate.

Effects of 5-aza-2'-deoxycytidine and trichostatin A on high glucose- and interleukin-1ß-induced secretory mediators from human retinal endothelial cells and retinal pigment epithelial cells.

PURPOSE: We aimed to elucidate the effects of two epigenetic inhibitors, 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A (TSA), on several key secretory mediators of diabetic retinopathy (DR) in human retinal endothelial cells (HRECs) and human retinal pigment epithelial (HRPE) cells treated with high glucose or interleukin-1ß (IL-1ß). METHODS: HRECs and HRPE cells were incubated in 30 mM D-glucose or 10 ng/ml IL-1ß with or without the presence of various concentrations of 5-aza-dC or TSA. The production of pigment epithelium derived factor (PEDF), vascular endothelial cell growth factor (VEGF), intercellular cell adhesion molecule-1 (ICAM-1), IL-1ß, and matrix metalloproteinase 2 (MMP2) was evaluated at the mRNA and protein levels using real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: In the 30 mM D-glucose and the 10 ng/ml IL-1ß condition, the expression of VEGF, ICAM-1, IL-1ß, and MMP2 was induced in the HRECs and the HRPE cells. PEDF was downregulated in the HRPE cells but upregulated in the HRECs. However, the PEDF-to-VEGF ratio, which is thought to be critical in DR, was downregulated in both cell types. 5-aza-dC dose-dependently alleviated VEGF, ICAM-1, IL-1ß, and MMP2 and reversed PEDF or the PEDF/VEGF ratio in both cell types. TSA had similar effects as 5-aza-dC on the target mediators. However, ICAM-1 production was aggravated in the HRECs while remaining unchanged in the HRPE cells after TSA was administered. CONCLUSIONS: Our results demonstrated that 5-aza-dC and TSA enhance the protective PEDF and the PEDF/VEGF ratio and ameliorate the adverse effects of diabetic stimuli in vitro, suggesting that these two drugs may be of potential therapeutic value in DR.

[Construction of recombinant adenovirus expressing shRNA targeting human leukocyte-derived arginine aminopeptidase gene].

AIM: To construct the recombinant adenovirus expressing small hairpin RNA (shRNA) targeting human leukocyte-derived arginine aminopeptidase (LRAP) gene and silence the expression of LRAP in human retinal microvascular endothelial cells (HRMECs). METHODS: Three pairs of oligonucleotides coding for shRNAs targeting human LRAP gene were designed and synthesized, and were cloned into the shuttle vector pRNAT-H1.1/Adeno after annealing. The three constructed shuttle plasmids, through homologous recombination with adenoviral backbone vector pAdEasy-1, were transformed into E.coli BJ5183-AD- to produce recombinant adenoviral plasmids. And then the recombinants linearized with Pac I were transfected into 293a cells to package adenoviruses. After amplification and titter determination, the recombinant adenoviruses were used to infect the primary HRMECs. Quantitative real-time PCR was taken to determine the relative amount of LRAP mRNA to screen the adenovirus with the highest silencing efficiency. The level of LRAP protein after RNA interference in HRMECs was further determined by Western blotting. RESULTS: PCR, restriction digestion and DNA sequencing confirmed that the purpose shRNA-coding sequences were correctly inserted into the shuttle vectors and adenoviral plasmids, and the recombinant adenoviruses were packaged successfully in 293a cells. The most effective adenovirus with the silencing efficiency up to 79% was selected by quantitative real-time PCR, which significantly lowered the expression of LRAP in HRMECs. CONCLUSION: The recombinant adenovirus expressing shRNA effectively silencing LRAP gene was constructed successfully, which would facilitate further study of the role that LRAP plays in the development of diabetic retinopathy.

Phosphomannopentaose sulfate (PI-88) suppresses angiogenesis by downregulating heparanase and vascular endothelial growth factor in an oxygen-induced retinal neovascularization animal model.

PURPOSE: Vascular endothelial growth factor (VEGF) is the most potent angiogenic mitogen, and has been associated with angiogenesis. Heparanase is an endoglycosidase that specifically cleaves heparan sulfate side chains, which can induce VEGF expression. The aims of the present study were to evaluate the heparanase expression and its relationship with VEGF in the retina of oxygen-induced retinopathy (OIR) mice, and to investigate the effect of the heparanase inhibitor phosphomannopentaose sulfate (PI-88) in the OIR retinas. METHODS: Seventy-seven newborn C57BL/6 mice were involved in this study. On postnatal day 7 (P7), pups were exposed to a hyperoxia condition (75% oxygen) for 5 days, and on P12, the mice were returned to room air. Control mice were exposed to room air from birth until P17, with normally developing retinal vasculature. PI-88 was administered intraperitoneally to OIR mice at a dose of 35.7 mg/kg/day for 5 consecutive days. The expression level of heparanase and VEGF in the retinas was assayed using immunohistochemistry, Q-RT-PCR, and western blot. RESULTS: The expression levels of heparanase and VEGF were increased in the OIR retinas compared with the control mice. The Q-RT-PCR results showed that the mRNA expression levels of heparanase and VEGF in OIR retina were increased 1.71 fold (p<0.0001) and 4.34 fold (p<0.0001), respectively. The western blot results showed that the protein expression levels of heparanase and VEGF were increased 1.49 fold (p<0.0001) and 1.72 fold (p<0.0001), respectively, in the OIR retinas compared with the normal retinas. The immunohistochemistry analysis revealed that the heparanase and VEGF signals were intense in the retinal vascular endothelia of the OIR mice but faint in those of the normal controls. The increased protein and mRNA expression levels of heparanase and VEGF in the mouse retinas were significantly decreased by PI-88 administration (p<0.0001). CONCLUSIONS: Heparanase expression was upregulated and correlated with an increase in VEGF expression in the OIR mouse retinas, and might be involved in the progress of retinopathy of prematurity. Inhibition of heparanase expression by PI-88 could be used as a novel therapeutic method for retinopathy of prematurity.