Profiling of HAT1-mediated Lysine Acetylation Modification in Liver Cancer / 中国生物化学与分子生物学报

Lysine acetylation has emerged as one of the most important post-translational modifications that participates in various biological and pathological processes. Histone acetyltransferase 1 (HAT1) as the first identified protein ε-amino lysine acetyltransferase is able to regulate the acetylation of histones and non-histone proteins. However‚ the acetylation substrates and sites mediated by HAT1 in liver cancer are poorly understood. In this study‚ we demonstrated that HAT1 was highly expressed in the liver cancer tissues‚ which was negatively associated with the prognosis of patients. Based on the establishment of the HAT1-knockout HepG2 cell line‚ we employed a quantitative proteomics approach to study the profiling of acetylation mediated by HAT1 in HepG2 cells. Interestingly‚ we identified a total of 858 Kac sites on 547 proteins in the HepG2 cell line‚ in which HAT1 mediated the levels of Kac of 74 sites on 68 proteins. The pathways and metabolic processes that were affected by HAT1-dependent acetylation modification were analyzed by bioinformatics. The results show that Kac regulates disease development‚ RNA biology‚ spliceosome and nucleosome assembly‚ oxidative stress‚ various signaling pathways and metabolic pathways‚ etc.. Moreover‚ we verified that the HAT1-mediated acetylation modification could promote abnormal lipid metabolism. CCK8 assays‚ clone formation and Edu assays revealed that HAT1 could remarkably enhance the cell proliferation of liver cancer in vitro. Thus‚ our finding explored the profiling of HAT1-mediated protein acetylation in HepG2 cells‚ which provides new insights into the underlying mechanism by which HAT1 mediates the development of liver cancer. Clinically‚ the HAT1-mediated acetylation sites could be used for the precise targets of drug development.

PCNA Confers the Conversion of Hepatitis B Virus Relaxed Circular DNA to Covalently Closed Circular DNA by Its DNA Binding Domain / 中国生物化学与分子生物学报

Chronic hepatitis B virus (HBV) infection is a primary cause for liver cancer. And the main challenge of curing hepatitis B is the elimination of the stable covalently closed circular DNA (cccDNA) of the viral genome. The formation of HBV cccDNA requires the filling of single-stranded region and the ligation of nicks in relaxed circular DNA (rcDNA) strands. Previously, our group reported that proliferating cell nuclear antigen (PCNA) was involved in the formation of HBV cccDNA. However, the underlying mechanism of the conversion of HBV rcDNA to cccDNA is poorly understood. In the present study, we aim to explore the mechanism by which PCNA contributes to the conversion of HBV rcDNA to cccDNA. Our data showed that PCNA was involved in the process of HBV rcDNA repair. The knockout of PCNA by the CRISPR/Cas9 system remarkably blocked the conversion of HBV rcDNA to cccDNA, while the ectopic expression of PCNA could effectively rescue the event (P<0. 001). Knockout of PCNA significantly slowed down the conversion kinetics of HBV rcDNA to cccDNA (P<0. 01). Mechanically, the DNA binding domain of PCNA was required for the process of HBV rcDNA repair to cccDNA (P<0. 01). Thus, we conclude that PCNA confers the conversion of HBV rcDNA to cccDNA by its DNA binding domain. Clinically, PCNA might serve as a novel target for antiviral therapy.

A new method to solve anophthalmic contracted socket in embedding orbital implant in 114 cases / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To perform a new method for orbital implant and contracted socket through one time and its results. ·METHODS:Totally 114 patients 114 eyes, from January 2008 to June 2014, with contracted socket participated in this study. We incised the bulbar conjunctiva horizontally and excised scar tissue, then implanted the hydroxyapatite in the four extraocular muscles and tightly sutured the Tenon ' capsule. After that, we put the superior and inferior conjunctival petals backwards and sutured them to the Tenon ' s capsule. All the patients were divided into four groups according to the vertical diameter length of the conjunctival defect area:GroupⅠ:≤5mm; Group Ⅱ: 6-10mm; Group Ⅲ: 11-15mm; and Group Ⅳ: ≥16mm. These patients were followed up for 6mo to 3y to observe the conjunctival sac shaping and growth of conjunctiva. ·RESULTS:There were 64 cases in GroupⅠ, 31 cases in Group Ⅱ, 16 cases in Group Ⅲ and 3 cases in Group Ⅳ. All patients ' conjunctival defect was covered by new conjunctiva and scar tissue 4 to 6wk after surgeries. Ten cases had contracted socket; 2 cases had orbital implant exposure, requiring reoperation. Of the 114 cases, 8 had contracted socket and could use a smaller conformer, 106 could use a normal size conformer. ·CONCLUSION: When the conjunctival defect was ≤15mm, this new method can address the orbital implant and contracted socket at the same time. While it was ≥16mm, flap transplantation is necessary.

Clinical diagnosis and treatment of intraorbital wooden foreign bodies / 中华创伤杂志(英文版)

<p><b>PURPOSE</b>The intraorbital wooden foreign body is often misdiagnosed or missed on computed tomog- raphy (CT) scan, due to the invisible or unclear images. The residual foreign bodies often occur during surgical removal. The clinical manifestations, imaging features and treatment of intraorbital wooden foreign bodies were discussed in this study.</p><p><b>METHOD</b>We retrospectively analyzed 14 cases of intraorbital wooden foreign bodies managed at our hospital between January 2007 and May 2015. All patients underwent orbital CT examination before surgery, and surgery was performed under general anesthesia with orbital wound debridement and suture, as well as exploration and removal of wooden foreign bodies.</p><p><b>RESULTS</b>At first, 11 cases underwent removal of foreign bodies, including 1 case with incomplete removal and then receiving a secondary surgery. Foreign bodies were not found in three cases with preoperative misdiagnosis and orbital MRI found residual foreign bodies in the orbit. Operations were performed via primary wound approach in eight cases, conjunctival approach in two cases, and anterior orbitotomy in four cases. Postoperatively, one case was complicated with eye injuries, three cases with ocular muscle injuries, eight cases with visual loss, and eight cases with orbital abscess. The length of foreign bodies ranged from 1.8 cm to 11.0 cm. The maximum of four foreign bodies were removed at the same time.</p><p><b>CONCLUSION</b>Because the imaging of orbital wooden foreign bodies is complex and varied, MRI should be combined when they are invisible on CT scan. At the same time injuries trajectory and clinical mani- festations of patients should be taken into account. Surgical exploration should be extensive and thor- ough, and foreign bodies and orbital abscess must be cleared.</p>

Development of the human/rat chimera model with neonatal rats / 中国实验血液学杂志

The purpose of this study was to transplant neonatal rat with human cord blood Lin(-) cells to test the possibility of this xenograft model. The Lin(-) cells were purified from human cord blood (CB) using negative selection strategy based on different lineage-specific antigens. The Lin(-) cells were injected into the liver of neonatal rats using a microinjector at an average of 5 x 10(5) cells for each. Peripheral blood (PB) and spleen were collected at 2,4 and 8 weeks after injection. Flow cytometry was performed to detect human cells in the rat PB, PCR was used to detect human cells in PB as well as spleen. The results showed that a definite proportion of human cells existed in peripheral blood of chimeric rat and the human specific beta2 microglobulin gene fragments were detected in spleen genomic DNA of chimeric rat. It is concluded that human/rat chimera model can be developed with neonatal rats. Human/rat xenograft model may provide a useful and convenient method for human hematopoietic stem cell assay in vivo.

Migration and differentiation of human bone marrow mesenchymal stem cells in the rat brain / 生理学报

Bone marrow mesenchymal stem cells (MSCs) are multipotent tissue stem cells that can be induced in vitro to differentiate into a variety of cells such as osteoblasts, chondrocytes and adipocytes. MSCs are useful vehicles for both cell and gene therapy for a variety of diseases. Here, we injected human MSCs with enhanced green fluorescent protein (EGFP) into the striatum of Parkinson disease (PD) rat and examined their survival, migration, differentiation, and the behavior changes in PD rats, which will provide a theoretical foundation and technical method for clinic PD therapy by stem cells. The results showed that human bone marrow MSCs can survive in rat brain for a long time (exceeding 70 d). MSCs were found in multiple areas of the rat brain including the striatum, the corpus callosum, contralateral cortex and even the brain vascular wall. Immunocytochemical staining suggested that implanted cells expressed human neurofilament (NF), neuron-specific enolase (NSE) and glial fibrillary acid protein (GFAP). At the same time, remission in abnormal behavior of the PD rats appeared. Rotation scores decreased gradually from 8.86+/-2.09 r/min pre-transplantation to 4.87+/-2.06 r/min 90 d post-transplantation (statistic result showed P<0.05).

Study on granulocytes derived from induction of committed differentiation of hematopoietic stem/progenitor cells ex vivo / 中国实验血液学杂志

To evaluated the feasibility of preventing infection after high dose chemotherapy and radiotherapy using the granulocytes derived from differentiated from hematopoietic stem/progenitor cells ex vivo, human CD34-positive cells were isolated from umbilical cord blood by using a high-gradient magnetic cell sorting system (MACS), and the cells committedly differentiated with hematopoietic cytokines (SCF + IL-3 + IL-6 + G-CSF) in a liquid culture system. The expanded cell number, ratio of the viable cells, chromosome and phenotype of the differentiated cells and safety analysis of expanded cells were detected by using cell count, trypan blue exclusion test, karyotype analysis, flow cytometry and tumorigenic model of nude mice, respectively. The results showed that the combination of cytokines increased cell number by (1006.4 +/- 103.2) folds and flow cytometric analysis showed myeloid marker CD11b expressed in the about 60% cells. The growth peak of differentiated cells was at 14 days of culture and decreased at about 33 days. No abnormality was found in the karyotype analysis of expanded cells. No tumor was found in the nude mice injected with expanded cells after 35 days and the expanded cells had the ability of phagocytizing bacteria. It is concluded that the cells, differentiated from CD34(+) cells, expanded ex vivo possess the function of granulocyte and it was safe for clinical trial.

Expression of telomerase during induction of committed differentiation of human cord blood hematopoietic stem/progenitor cells in vitro / 中国实验血液学杂志

To investigate the expression of telomerase in cord blood hematopoietic stem/progenitor cells during their committed differentiation in vitro and provide an index of monitoring the proliferating potential of the hematopoietic stem/progenitor cells and security for clinical application. Human CD34 positive cells were isolated from umbilical cord blood by using magnetic cell sorting system (MACS), and were induced to differentiation with hematopoietic growth factors (SCF + IL3 + IL6 + GCSF and SCF + IL3 + IL6 + EPO) in a liquid culture system. The telomerase activity and the cytalytic subunit of telomerase (hTERT) of the cells were analysed during different periods of culture by using TRAP-PCR, TRAP-ELISA, Western blot and RT-PCR techniques, respectively. The results showed that a peak of cell growth was achieved on day 14 - 21 during induction of differentiation in vitro. Total cell number could increase 1006.4 +/- 103.2 times and could not increase there after. Telomerase activity and hTERT expression were low in freshly isolated cord blood CD34(+) cells and increased after about 7 days of culture in addition of cytokine combinations of SCF + IL3 + IL6 + GCSF and SCF + IL3 + IL6 + EPO, respectively. The telomerase activity and hTERT decreased after 14 days of culture and were not detected after 28 days of culture. It was concluded that the hematopoietic stem/progenitor cells can be expanded in large number in vitro and do not have the character of immortality and the telomerase activity could be a useful index in hematopoiesis regulation.

Establishment of a Human Umbilical Vein Endothelial Cell Line Supporting Hematopoiesis In Vitro / 中国实验血液学杂志

Endothelial cells are the critical cell component of hematopoietic microenvironment. For the purpose of facilitating the study on modulating effect of endothelial cells in hematopoiesis, a human umbilical vein cell line, IEC, was established. Primary human umbilical vein endothelial cells were transfected with the plasmid pSV(3neo) carried SV40 large T antigen by lipofection. The IEC cells expressed factor VIII and the UEA I-binding ratio was about 97%. The chromosome variation was existed in the cell line, with the karyotype 45, XX, -18, 18q(+). The cell line retained the proliferative capacity at least 25 passages. IEC cells stimulated the growth of granulocyte-macrophage progenitor cells in coculture of cord blood CD34(+) cells with IEC cells. It is concluded that IEC cell line possessed the biological features of endothelial cell and supported hematopoiesis in vitro.

Human umbilical vein endothelial cells support hematopoiesis and expansion of hematopoietic stem/progenitor cells in vitro / 军事医学科学院院刊

Objective: To investigate the role of human umbilical vein endothelial cells (HUVEC) in supporting hematopoiesis and the expansion of hematopoietic stem/progenitor cells in vitro. Methods: According to the fact that HUVEC supernatant has colony stimulating activity shown by methylcellulose colony-forming assay and HUVEC can maintain the survival of mononuclear cells for at least four weeks in vitro, CD34+ cells from umbilical cord blood were seeded with (HUVEC group) or without (control group) HUVEC monolayer. Every week cells were collected and counted, the frequency of CFU-GM was measured by using methylcellulose colony-forming assay, and the percentage of CD34+ and CD41a+ cells was measured by flow cytometry. Results: In control group，all the CD34+ cells died in two weeks. However, in HUVEC group,most nucleated cells and CD34+ cells were expanded by 68.1±14.8 fold and 6.6±1.4 fold，respectively at the third week while CFU-GM expansion reached its peak (5.7±2.1 fold) at the week 2. Moreover, the percentage of CD41a+ cells was enhanced significantly, reaching a maximum (15.6%) at the week 3. Conclusions:HUVEC can support hematopoiesis in vitro and expand the hematopoietic progenitor cells and CD41a+ cells in direct contact coculture.

The Presence of Endothelial Cell Precursors in Blood Circulation / 中国实验血液学杂志

In the present study, an attempt was made to prove the question whether endothelial cell precursors exist in blood circulation during postnatal period. CD34(+) cells were harvested from G-CSF mobilized adult blood and umbilical cord blood and incubated onto fibronectin/gelatin-coated Petric dishes in the presence of recombinant human vascular endothelial cell growth factor(rhVEGF) and basic fibroblast growth factor(rhbFGF). Endothelial cell lineage was identified by von Willebrand factor(vWF) expression and Ulex europous agglutinin I(UEA-I) binding capacity. The results showed that a firmly adherent cell monolayer formed when CD34(+) cells, but not CD34(-) cells, were cultured for 5 - 6 weeks as described before. Immunocytochemistry and flow cytometry analysis showed that almost all of the adherent cells were vWF-positive and around 90% were able to bind UEA-I specifically. These findings demonstrate that angioblasts exist in the circulation during postnatal life and therefore, vasculogenesis might occur in adults.