Antithymocyte Globulin for Matched Sibling Donor Transplantation in Patients With Hematologic Malignancies: A Multicenter, Open-Label, Randomized Controlled Study.

PURPOSE: The role of antithymocyte globulin (ATG) in preventing acute graft-versus-host disease (aGVHD) after HLA-matched sibling donor transplantation (MSDT) is still controversial. PATIENTS AND METHODS: We performed a prospective, multicenter, open-label, randomized controlled trial (RCT) across 23 transplantation centers in China. Patients ages 40-60 years with standard-risk hematologic malignancies with an HLA-matched sibling donor were randomly assigned to an ATG group (4.5 mg/kg thymoglobulin plus cyclosporine [CsA], methotrexate [MTX], and mycophenolate mofetil [MMF]) and a control group (CsA, MTX, and MMF). The primary end point of this study was grade 2-4 aGVHD on day 100. RESULTS: From November 2013 to April 2018, 263 patients were enrolled. The cumulative incidence rate of grade 2-4 aGVHD was significantly reduced in the ATG group (13.7%; 95% CI, 13.5% to 13.9%) compared with the control group (27.0%; 95% CI, 26.7% to 27.3%; P = .007). The ATG group had significantly lower incidences of 2-year overall chronic GVHD (27.9% [95% CI, 27.6% to 28.2%] v 52.5% [95% CI, 52.1% to 52.9%]; P < .001) and 2-year extensive chronic GVHD (8.5% [95% CI, 8.4% to 8.6%] v 23.2% [95% CI, 22.9% to 23.5%]; P = .029) than the control group. There were no differences between the ATG and control groups with regard to cytomegalovirus reactivation, Epstein-Barr virus reactivation, 3-year nonrelapse mortality (NRM), 3-year cumulative incidence of relapse (CIR), 3-year overall survival, or 3-year leukemia-free survival. Three-year GVHD relapse-free survival was significantly improved in the ATG group (38.7%; 95% CI, 29.9% to 47.5%) compared with the control group (24.5%; 95% CI, 16.9% to 32.1%; P = .003). CONCLUSION: Our study is the first prospective RCT in our knowledge to demonstrate that ATG can effectively decrease the incidence of aGVHD after MSDT in the CsA era without affecting the CIR or NRM.

Current Treatment Patterns of Aplastic Anemia in China: A Prospective Cohort Registry Study.

Aplastic anemia (AA) is a hematologic disease characterized by pancytopenia and hypocellular bone marrow, potentially leading to chronic anemia, hemorrhage, and infection. The China Aplastic Anemia Committee and British Committee for Standards in Haematology guidelines recommend hematopoietic stem-cell transplantation (HSCT) or immunosuppressive therapy (IST) comprising antithymocyte globulin (ATG) with cyclosporine (CsA) as initial treatment for AA patients. With limited epidemiological data on the clinical management of AA in Asia, a prospective cohort registry study involving 22 AA treatment centers in China was conducted to describe the disease characteristics of newly diagnosed AA patients and investigate real-world treatment patterns and patient outcomes. Of 340 AA patients, 72.9, 12.6, and 3.5% were receiving IST, traditional Chinese medicine, and HSCT, respectively, at baseline; only 22.2% of IST-treated patients received guideline-recommended ATG with CsA initially. Almost all patients received supportive care (95.6%) as blood transfusion (97.8%), antibiotics (63.7%), and/or hematopoietic growth factors (58.2%). Overall, 64.8% achieved a partial or complete response, and 0.9% experienced relapse. No new safety concerns were identified; serious adverse events were largely unrelated to the treatment regimen. These results demonstrate the need to identify and minimize treatment barriers to standardize and align AA management in China with treatment guideline recommendations and further improve patient outcomes.

Notch Signaling Modulates Macrophage Polarization and Phagocytosis Through Direct Suppression of Signal Regulatory Protein α Expression.

The Notch pathway plays critical roles in the development and functional modulation of myeloid cells. Previous studies have demonstrated that Notch activation promotes M1 polarization and phagocytosis of macrophages; however, the downstream molecular mechanisms mediating Notch signal remain elusive. In an attempt to identify Notch downstream targets in bone marrow-derived macrophages (BMDMs) using mass spectrometry, the signal regulatory protein α (SIRPα) appeared to respond to knockout of recombination signal-binding protein Jk (RBP-J), the critical transcription factor of Notch pathway, in macrophages. In this study, we validated that Notch activation could repress SIRPα expression likely via the Hes family co-repressors. SIRPα promoted macrophage M2 polarization, which was dependent on the interaction with CD47 and mediated by intracellular signaling through SHP-1. We provided evidence that Notch signal regulated macrophage polarization at least partially through SIRPα. Interestingly, Notch signal regulated macrophage phagocytosis of tumor cells through SIRPα but in a SHP-1-independent way. To access the translational value of our findings, we expressed the extracellular domains of the mouse SIRPα (mSIRPαext) to block the interaction between CD47 and SIRPα. We demonstrated that the soluble mSIRPαext polypeptides could promote M1 polarization and increase phagocytosis of tumor cells by macrophages. Taken together, our results provided new insights into the molecular mechanisms of notch-mediated macrophage polarization and further validated SIRPα as a target for tumor therapy through modulating macrophage polarization and phagocytosis.

Three-year Follow-up on the Safety and Effectiveness of Rituximab Plus Chemotherapy as First-Line Treatment of Diffuse Large B-Cell Lymphoma and Follicular Lymphoma in Real-World Clinical Settings in China: A Prospective, Multicenter, Noninterventional Study.

BACKGROUND: Prospective real-life data on the safety and effectiveness of rituximab in Chinese patients with diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma (FL) are limited. This real-world study aimed to evaluate long-term safety and effectiveness outcomes of rituximab plus chemotherapy (R-chemo) as first-line treatment in Chinese patients with DLBCL or FL. Hepatitis B virus (HBV) reactivation management was also investigated. METHODS: A prospective, multicenter, single-arm, noninterventional study of previously untreated CD20-positive DLBCL or FL patients receiving first-line R-chemo treatment at 24 centers in China was conducted between January 17, 2011 and October 31, 2016. Enrolled patients underwent safety and effectiveness assessments after the last rituximab dose and were followed up for 3 years. Effectiveness endpoints included progression-free survival (PFS) and overall survival (OS). Safety endpoints were adverse events (AEs), serious AEs, drug-related AEs, and AEs of special interest. We also reported data on the incidence of HBV reactivation. RESULTS: In total, 283 previously untreated CD20-positive DLBCL and 31 FL patients from 24 centers were enrolled. Three-year PFS was 59% (95% confidence interval [CI]: 50-67%) for DLBCL patients and 46% (95% CI: 20-69%) for FL patients. For DLBCL patients, multivariate analyses showed that PFS was not associated with international prognostic index, tumor maximum diameter, HBV infection status, or number of rituximab treatment cycles, and OS was only associated with age >60 years (P < 0.05). R-chemo was well tolerated. The incidence of HBV reactivation in hepatitis B surface antigen (HBsAg)-positive and HBsAg-negative/hepatitis B core antibody-positive patients was 13% (3/24) and 4% (3/69), respectively. CONCLUSIONS: R-chemo is effective and safe in real-world clinical practice as first-line treatment for DLBCL and FL in China, and that HBV reactivation during R-chemo is manageable with preventive measures and treatment. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01340443; https://clinicaltrials.gov/ct2/show/NCT01340443.

Protective roles and mechanisms of polysaccharides from Dendrobium officinal on natural aging-induced premature ovarian failure.

This study was designed to investigate the pharmacological effects and mechanisms of polysaccharides from Dendrobium officinal (DOP) on premature ovarian failure (POF) in natural aging mice. Fifteen months old female mice (n  =  28) and young adult female mice (n  =  14, 6 weeks) were used. DOP (70 mg/kg) was administrated to mice by oral gavage for 10 weeks and the protection effects of DOP on ovaries were investigated in vivo. The results showed that DOP reduced body weight, ovary and uterus/body weight parameters to normal level and alleviated ovarian pathological damage. Moreover, DOP could reduce pro-inflammatory cytokines (TNF-α, IL-6) and MDA levels and improve estradiol, SOD, GSH-Px, T-AOC and IL-10 levels in serum. These results suggested that DOP may alleviate the damage caused by aging through the inhibition of the nuclear factor -κB (NF-κB) and p53/Bcl-2-mediate signaling pathways. Moreover, we found that DOP can increase the numbers of mitochondria and endoplasmic reticulum. Moreover, DOP increased the numbers of different stages of follicular cells and improved mitochondrial membrane potential in ovaries. These results indicated that DOP may relieve ovarian damage through the protection of mitochondria in the ovaries. These findings suggest that DOP may be a promising drug for treating POF caused by natural aging in females.

[Prokaryotic Expression and Purification of the Notch Ligand and Its Effect on Hematopoiesis after Carbon Tetrachloride Damage].

OBJECTIVE: To express and purify the mouse endothelial cell-targeted recombinant Notch ligand protein mD1R, and to investigate its effect on hematopoiesis after carbon tetrachloride damage. METHODS: PCR was performed to clone and construct the expression vector pET22b(+)-mD1R. The mD1R successfully transformed into E. coli was induced by IPTG, and purified with Ni2+-beads affinity chromatography. The target protein was detected by SDS-PAGE. The fluorescence-activated cell sorting analysis (FACS), cell adhesion test, immunofluorescence staining and quantitative real-time PCR were employed to detect the endothelial cell-targeted and Notch signaling-activated biological characteristics of mD1R. The carbon tetrachloride mouse model was established to observe the effects of mD1R on the hematopoietic stem cell (HSC), myeloid cells and lymphoid cells by flow cytometry. The Lin-Scal-1+c-Kit+ cells were sorted by magnetic bead, FACS was performed to analyze the cell cycle, and RT-PCR was employed to observe the expression of interleukin (IL)-10. RESULTS: The prokaryotic expression vector was successfully cloned and constructed. The purity and the activity were confirmed in mD1R recombinant protein. The purified mD1R activated the Notch signaling pathway of hematopoietic stem cells in carbon tetrachloride damaged mouse, and internally elevated the number of HSC and long-term HSC to 2.96-fold and 6.18-fold. In addition, mD1R improved the amplification of the myeloid progenitor cells and the myeloid-derived suppressor cells, particularly the granulocyte/monocyte into blood. Mechanistically, the further analyses suggested that Notch pathway could increase the proliferation of HSC and enhance expression of IL-10 after stress injury. CONCLUSIONS: A new and activated recombinant Notch ligand protein has been obtained successfully to communicate hematopoietic stem cells and hematopoietic microenvironment. The Notch- mediated intrinsic hematopoiesis has been regulated by the anti-inflammatory factor after stress injury.

Recent advance on genome editing for therapy of ß-hemoglobinopathies.

ß-hemoglobinopathies are one of six groups of common illnesses affecting human health. Although the genetic mechanisms have been elucidated for several decades, curable treatment options, other than allogeneic bone marrow transplantation, are still lacking. In recent years, rapid development in genome editing technologies and their clinical applications have opened up new directions for treatment of ß-hemoglobinopathies. Genome editing technologies, as applied in autologous CD34 + hematopoietic stem and progenitor cells, represents a promising remedial means for the ß-globin disorders. Hemoglobin gene mutations could be corrected with homologous recombination-mediated DNA repair pathway to repair the genetic defects, while the nonhomologous end-joining pathway may be used to silence the key repressor of fetal globin expression and reactivate fetal hemoglobin expression, thereby alleviating the clinical symptoms of ß-hemoglobinopathies in patients. This review summarizes the recent advances on genome editing of ß-hemoglobinopathies from the bench design to the establishment of clinical translational platforms, thereby providing critical insights and references on the application of genome editing technologies for the development of therapeutic strategies for ß-hemoglobinopathies.

[Establishment and Identification of SCL-tTA/BCR-ABL Transgenic Mouse Model with Chronic Myeloid Leukemia].

OBJECTIVE: To establish transgenic mouse model with chronic myeloid leukemia(CML) by tetracycline withdrawal, so as to provide the experimental tool for studying pathogenesis of CML and searching new therapeutic method for this disease. METHODS: The BCR-ABL expression in stem and progenitor cells in SCL-tTA/BCR-ABL transgenic mice was induced by tetracycline withdrawal in drinking water; and the peripheral hemogram and spleen index were examined after identifying genotypes in mice; the distribution of hematopoietic lineage in bone marrow, spleen and peripheral blood was detected by flow cytometry. RESULTS: As compared with the control mice, the peripheral hemogram showed the obvious increase of neutrophile granulocyte count and spleen index in BCR-ABL transgenic mice. All induced double transgenic mice showed a severe myeloid cell expansion (Gr-1+Mac-1+) and reduction in T (CD3+) and B(B220+) cell lineages in bone marrow, spleen and peripheral blood. CONCLUSION: A mouse model to induce BCR-ABL expression is successfully set up by tetracycline withdrawal, which resembles chronic phase CML.

Effect of Dendrobium officinale on D-galactose-induced aging mice.

OBJECTIVE: To examine the effect of Dendrobium officinale (DO) on D-galactose-induced aging mice. METHODS: Aging mice was induced by D-galactose at 0.125 g/kg for 10 weeks through subcutaneous injection except for the negative control group. After 10 days, according to complete random design, the aging modeling mice were randomized into 4 groups: aging control group (10 ML·kg-1·d-1) of distilled water), positive control group (vitamin B6 and ganodema lucidum tablets with a dose of 1 tablet/kg), DO-1 treatment group (DO juice with a dose of 1 g/kg), DO-2 treatment group (DO Polysaccharide with a dose of 0.32 g/kg), 14 mice in each group. All the animals were orally medicated daily for 9 weeks. Cognitive function assessment was performed using the maze test and step-down test. At the end of experiment, the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) levels in the serum, the SOD, GSH-Px and nitric oxide (NO) levels in the cerebrum, the SOD and catalase (CAT) levels in the liver, the SOD and NO levels in the heart, and the SOD level in the kidney, were determined using commercial kits. The spleen, liver, heart, cerebrum and kidney were excised for histological study. RESULTS: Compared to aging control group, DO shortened the time of passing through the maze and prolong the step-down latency of aging mice (P <0.05 or P<0.01). DO markedly up-regulated serum levels of SOD, GSH-Px and T-AOC, and restored SOD levels in the heart, liver, kidney and cerebrum to normal status (P<0.05 or P<0.01). DO at the dose of 1 g/kg also signififi cantly improved the degree of spleen lesions (P<0.01). CONCLUSIONS: DO had marked anti-aging effect on D-galactose-induced model of aging. The underlying mechanism could be related to modulation on antioxidation system and immune system. The results indicated that DO could potentially be used as natural drugs or functional foods for preventing aging.

The long-term outcome of reduced-intensity allogeneic stem cell transplantation from a matched related or unrelated donor, or haploidentical family donor in patients with leukemia: a retrospective analysis of data from the China RIC Cooperative Group.

This study compared 6-year follow-up data from patients undergoing reduced-intensity conditioning (RIC) transplantation with an HLA-matched related donor (MRD), an HLA-matched unrelated donor (MUD), or an HLA-haploidentical donor (HID) for leukemia. Four hundred and twenty-seven patients from the China RIC Cooperative Group were enrolled, including 301 in the MRD, 79 in the HID, and 47 in the MUD groups. The conditioning regimen involved fludarabine combined with anti-lymphocyte globulin and cyclophosphamide. Graft-versus-host disease (GVHD) prophylaxis was administered using cyclosporin A (CsA) and mycophenolate mofetil (MMF). Four hundred and nineteen patients achieved stable donor chimerism. The incidence of stage II-IV acute GVHD in the HID group was 44.3 %, significantly higher than that in the MRD (23.6 %) and MUD (19.1 %) groups. The 1-year transplantation-related mortality (TRM) rates were 44.3, 17.6, and 21.3, respectively. Event-free survival (EFS) at 6 years in the HID group was 36.7 %, significantly lower than that of the MRD and MUD groups (59.1 and 66.0 %, P < 0.001 and P = 0.001, respectively). For advanced leukemia, the relapse rate of the HID group was 18.5 %, lower than that of the MRD group (37.5 %, P = 0.05), but the EFS at 6 years was 31.7 and 30.4 % (P > 0.05), respectively. RIC transplantation with MRD and MUD had similar outcome in leukemia which is better than that with HID. RIC transplantation with HID had lower relapsed with higher TRM and GVHD rate, particularly in advanced leukemias. RIC transplantation with MRD and MUD had similar outcomes in leukemia and they were better than those with HID. RIC transplantation with HID had a lower relapse rate but higher TRM and GVHD rates, particularly in cases of advanced leukemia.

Genomic Profiling of Adult and Pediatric B-cell Acute Lymphoblastic Leukemia.

Genomic landscapes of 92 adult and 111 pediatric patients with B-cell acute lymphoblastic leukemia (B-ALL) were investigated using next-generation sequencing and copy number alteration analysis. Recurrent gene mutations and fusions were tested in an additional 87 adult and 93 pediatric patients. Among the 29 newly identified in-frame gene fusions, those involving MEF2D and ZNF384 were clinically relevant and were demonstrated to perturb B-cell differentiation, with EP300-ZNF384 inducing leukemia in mice. Eight gene expression subgroups associated with characteristic genetic abnormalities were identified, including leukemia with MEF2D and ZNF384 fusions in two distinct clusters. In subgroup G4 which was characterized by ERG deletion, DUX4-IGH fusion was detected in most cases. This comprehensive dataset allowed us to compare the features of molecular pathogenesis between adult and pediatric B-ALL and to identify signatures possibly related to the inferior outcome of adults to that of children. We found that, besides the known discrepancies in frequencies of prognostic markers, adult patients had more cooperative mutations and greater enrichment for alterations of epigenetic modifiers and genes linked to B-cell development, suggesting difference in the target cells of transformation between adult and pediatric patients and may explain in part the disparity in their responses to treatment.

Hyperglycemia-induced PATZ1 negatively modulates endothelial vasculogenesis via repression of FABP4 signaling.

Vascular endothelial dysfunction, a central hallmark of diabetes, predisposes diabetic patients to numerous cardiovascular complications. The POZ/BTB and AT-hook-containing zinc finger protein 1 (PATZ1), is an important transcriptional regulatory factor and regulates divergent pathways depending on the cellular context, but its role in endothelial cells remains poorly understood. Herein, we report for the first time that endothelial PATZ1 expression was abnormally upregulated in diabetic endothelial cells (ECs) regardless of diabetes classification. This stimulatory effect was further confirmed in the high glucose-treated human umbilical vein endothelial cells (HUVECs). From a functional standpoint, transgenic overexpression of PATZ1 in endothelial colony forming cells (ECFCs) blunted angiogenesis in vivo and rendered endothelial cells unresponsive to established angiogenic factors. Mechanistically, PATZ1 acted as a potent transcriptional corepressor of fatty acid-binding protein 4 (FABP4), an essential convergence point for angiogenic and metabolic signaling pathways in ECs. Taken together, endothelial PATZ1 thus potently inhibits endothelial function and angiogenesis via inhibition of FABP4 expression, and abnormal induction of endothelial PATZ1 may contribute to multiple aspects of vascular dysfunction in diabetes.

[Correlation between Plasma microRNA Expression and Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To investigate the microRNA (miRNA) expression in plasma of patients with aGVHD and without aGVHD after allo-hematopoietic stem cell transplantation (allo-HSCT). METHODS: The miRNAs (miR-423, mirR199a-3p, miR93*, miR377) expression levels in peripheral blood plasma of 25 patients before and after allo-HSCT were detected by real-time PCR. RESULTS: miR-423, miR199a-3p and miR-93* in aGVHD group were significantly upregulated (P<0.05); miR-377 expression was not significantly different between aGVHD and non-aGVHD (P>0.05). CONCLUSION: The expression of miR-423, miR-199a-3p, miR-93* are upregulated in aGVHD group, which can be used as biomarkes to monitor and to diagnose aGVHD.

Disruption of Notch signaling aggravates irradiation-induced bone marrow injury, which is ameliorated by a soluble Dll1 ligand through Csf2rb2 upregulation.

Physical and chemical insult-induced bone marrow (BM) damage often leads to lethality resulting from the depletion of hematopoietic stem and progenitor cells (HSPCs) and/or a deteriorated BM stroma. Notch signaling plays an important role in hematopoiesis, but whether it is involved in BM damage remains unclear. In this study, we found that conditional disruption of RBP-J, the transcription factor of canonical Notch signaling, increased irradiation sensitivity in mice. Activation of Notch signaling with the endothelial cell (EC)-targeted soluble Dll1 Notch ligand mD1R promoted BM recovery after irradiation. mD1R treatment resulted in a significant increase in myeloid progenitors and monocytes in the BM, spleen and peripheral blood after irradiation. mD1R also enhanced hematopoiesis in mice treated with cyclophosphamide, a chemotherapeutic drug that induces BM suppression. Mechanistically, mD1R increased the proliferation and reduced the apoptosis of myeloid cells in the BM after irradiation. The ß chain cytokine receptor Csf2rb2 was identified as a downstream molecule of Notch signaling in hematopoietic cells. mD1R improved hematopoietic recovery through up-regulation of the hematopoietic expression of Csf2rb2. Our findings reveal the role of Notch signaling in irradiation- and drug-induced BM suppression and establish a new potential therapy of BM- and myelo-suppression induced by radiotherapy and chemotherapy.

Endothelium-targeted human Delta-like 1 enhances the regeneration and homing of human cord blood stem and progenitor cells.

BACKGROUND: Umbilical cord blood (UCB) is becoming an alternative cell source for hematopoietic stem cell transplantation (HSCT). However, umbilical cord blood transplantation (UCBT) has been severely limited by low and finite numbers of hematopoietic stem cells and their delayed engraftment. New strategies are needed to improve ex vivo expansion efficiency and in vivo haematopoietic recovery. METHODS: We produced an endothelium-targeted soluble Notch ligand, the Delta-Serrate-Lag-2 (DSL) domain of human Delta-like 1 fused with a RGD motif (hD1R), and tested the effects of this protein on human umbilical cord blood hematopoietic stem and progenitor cell (UCB-HSPC) ex vivo and in vivo. RESULTS: hD1R-mediated ex vivo expansion system was able to significantly increase the absolute number of UCB-HSPCs. The hD1R-expanded cells had the enhanced homing and maintained long-term hematopoietic stem cell repopulation capacity in the bone marrow of immunodeficient nonobese diabetic-severe combined immunodeficient (NOD/SCID) mice. Moreover, systemic administration of hD1R promoted the in vivo regeneration of donor cells in recipient mice and accelerated hematopoietic recovery, particularly in settings wherein the HSPCs dose was limiting. CONCLUSIONS: Our results indicated that hD1R might be applied in improving hematopoietic recovery and HSC engraftment in human UCBT.

Standardized fluorescence in situ hybridization testing based on an appropriate panel of probes more effectively identifies common cytogenetic abnormalities in myelodysplastic syndromes than conventional cytogenetic analysis: a multicenter prospective study of 2302 patients in China.

In an attempt to establish the advantages of fluorescence in situ hybridization (FISH) studies over conventional cytogenetic (CC) analysis, a total of 2302 de novo MDS patients from 31 Chinese institutions were prospectively selected in the present study for both CC and standardized FISH analysis for +8, -7/7q-, -5/5q-, 20q- and-Y chromosomal abnormalities. CC analysis was successful in 94.0% of the patients; of these patients, 35.9% of the cases were abnormal. FISH analysis was successful in all 2302 patients and detected at least one type of common cytogenetic abnormality in 42.7% of the cases. The incidences of +8, -7/7q-, -5/5q-, 20q- and-Y chromosomal abnormalities by FISH were 4.1% to 8.7% higher than those by CC. FISH identified abnormalities in 23.6% of the patients exhibiting normal CC results and revealed that 20.7% of the patients with adequate normal metaphases (≥20) had abnormal clones. FISH identified cytogenetic abnormalities in 50.4% of the patients with failed CC analysis. In summary, our multicenter studies emphasised and confirmed the importance of applying standardized FISH testing based on an appropriate panel of probes to detect common cytogenetic abnormalities in Chinese de novo MDS patients, particularly those with normal or failed CC results.

[Construction and expression of fusion protein TRX-hJagged1 in E.coli BL21].

This study was purposed to construct prokaryotic expression vector and to investigate the expression of Notch ligand Jagged1 in E.coli. An expression vector pET-hJagged1 was constructed, which can be inserted in Jagged1 with different lengths, but the DSL domain of human Jagged1 should be contained. Then the recombinant plasmids were transformed into the competent cell of E.coli BL21, and the expression of the fusion protein was induced by IPTG. Fusion protein was purified from the supernatant of cell lysates via the Nickel affinity chromatography. The results showed that prokaryotic expression vectors pET-hJagged1 (Bgl II), pET-hJagged1 (Hind I) and pET-hJagged1 (Stu I) were successfully constructed, but only pET-hJagged1 (Stu I) could express the soluble TRX-hJagged1. The purified TRX-Jagged1 protein could be obtained via the Nickel affinity chromatography, and then confirmed by Western Blot. It is concluded that prokaryotic expression vector pET-hJagged1 is successfully constructed, but only pET-hJagged1 (Stu I) can express the soluble TRX-hJagged1 and the TRX-Jagged1 fusion protein is obtained through the prokaryotic expression system, which laid a solid foundation for further to explore the effects of Jagged1 in hematopoietic and lymphoid system.

FHL1C induces apoptosis in Notch1-dependent T-ALL cells through an interaction with RBP-J.

BACKGROUND: Aberrantly activated Notch signaling has been found in more than 50% of patients with T-cell acute lymphoblastic leukemia (T-ALL). Current strategies that employ γ-secretase inhibitors (GSIs) to target Notch activation have not been successful. Many limitations, such as non-Notch specificity, dose-limiting gastrointestinal toxicity and GSI resistance, have prompted an urgent need for more effective Notch signaling inhibitors for T-ALL treatment. Human four-and-a-half LIM domain protein 1C (FHL1C) (KyoT2 in mice) has been demonstrated to suppress Notch activation in vitro, suggesting that FHL1C may be new candidate target in T-ALL therapy. However, the role of FHL1C in T-ALL cells remained unclear. METHODS: Using RT-PCR, we amplified full-length human FHL1C, and constructed full-length and various truncated forms of FHL1C. Using cell transfection, flow cytometry, transmission electron microscope, real-time RT-PCR, and Western blotting, we found that overexpression of FHL1C induced apoptosis of Jurkat cells. By using a reporter assay and Annexin-V staining, the minimal functional sequence of FHL1C inhibiting RBP-J-mediated Notch transactivation and inducing cell apoptosis was identified. Using real-time PCR and Western blotting, we explored the possible molecular mechanism of FHL1C-induced apoptosis. All data were statistically analyzed with the SPSS version 12.0 software. RESULTS: In Jurkat cells derived from a Notch1-associated T-ALL cell line insensitive to GSI treatment, we observed that overexpression of FHL1C, which is down-regulated in T-ALL patients, strongly induced apoptosis. Furthermore, we verified that FHL1C-induced apoptosis depended on the RBP-J-binding motif at the C-terminus of FHL1C. Using various truncated forms of FHL1C, we found that the RBP-J-binding motif of FHL1C had almost the same effect as full-length FHL1C on the induction of apoptosis, suggesting that the minimal functional sequence in the RBP-J-binding motif of FHL1C might be a new drug candidate for T-ALL treatment. We also explored the molecular mechanism of FHL1C overexpression-induced apoptosis, which suppressed downstream target genes such as Hes1 and c-Myc and key signaling pathways such as PI3K/AKT and NF-κB of Notch signaling involved in T-ALL progression. CONCLUSIONS: Our study has revealed that FHL1C overexpression induces Jurkat cell apoptosis. This finding may provide new insights in designing new Notch inhibitors based on FHL1C to treat T-ALL.

Endothelium-targeted Delta-like 1 promotes hematopoietic stem cell expansion ex vivo and engraftment in hematopoietic tissues in vivo.

BACKGROUND: Notch ligands enhance ex vivo expansion of hematopoietic stem cells (HSCs). But to use Notch ligands in HSC therapies of human diseases, efforts are required to improve ex vivo expansion efficiency and in vivo transplant engraftment. DESIGN AND METHODS: We designed and produced an endothelium-targeted soluble Notch ligand, the DSL domain of Delta-like 1 fused with a RGD motif (D1R), and examined the effects of this protein on HSCs ex vivo and in vivo. RESULTS: D1R efficiently promoted ex vivo expansion of both mouse bone marrow (BM) and human umbilical cord blood HSCs. HSCs expanded with D1R up-regulated many of the stemness-related genes, and showed high BM engraftment efficacy with long-term repopulation capacity after transplantation. Moreover, in vivo administration of D1R increased the number of BM HSCs in mice, and facilitated BM recovery of mice after irradiation. Injection of D1R significantly improved HSC engraftment and myeloid recovery after BM transplantation in irradiated mice. D1R enhanced HSC engraftment not only in BM, but also in the liver and spleen after BM transplantation in mice. D1R induced the formation of compact cell clusters containing the transplanted HSCs in close contact with endothelial cells, reminiscent of HSC niches, in the liver and spleen. CONCLUSIONS: D1R might be applied in improving both HSC expansion ex vivo and HSC engraftment in vivo in transplantation.

Deletion of RBP-J in dendritic cells compromises TLR-mediated DC activation accompanied by abnormal cytoskeleton reorganization.

Dendritic cells (DCs) are professional antigen presenting cells that activate and modulate immune responses, but the mechanisms underlying DC activation have not been fully understood. In this study, we investigated the role of Notch signaling in DC activation by using murine bone marrow-derived DCs. Triggering of Toll-like receptors (TLRs) of DCs led to upregulated expression of Notch ligands. Disruption of Notch signaling by the deletion of RBP-J, the critical transcription factor mediating the canonical signaling from all Notch receptors, resulted in a reduced capacity of DCs in activating T cells. Moreover, RBP-J deficiency altered the polarization of T cell activation, as manifested by downregulated interferon-γ and upregulated interleukin-4 and -10 expressions after LPS or Poly(I:C) stimulation. Furthermore, we found that RBP-J(-/-) DCs had reduced intracellular calcium after TLR-triggering. Immunofluorescent staining showed that RBP-J deficient DCs exhibited attenuated cytoskeleton reorganization when contacting T cells. In summary, our results suggested that the canonical Notch signaling promotes the cytoskeleton reorganization and the TLR-mediated DC activation.