Effects of histone acetyltransferase MYST2 on pancreatic cancer / 中华消化杂志

Objective:To investigate the expression at protein level and diagnostic value of histone acetyltransferase MYST2 in pancreatic cancer.Methods:From December 1st, 2017 to June 30th, 2020, at Peking Union Medical College Hospital, a total of 54 cases of pancreatic cancer tissues and corresponding paracancerous pancreatic tissues (>5 cm from the surgical margin) resected and confirmed by pathology were collected. ASPC1 and BXPC3 pancreatic cancer cell lines were knocked down (ASPC1 and BXPC3 knockdown group), CFPAC1 and SW1990 pancreatic cancer cell lines were overexpressed (CFPAC1 and SW1990 overexpression group), the untreated ASPC1, BXPC3, CFPAC1 and SW1990 were set as blank vector control group. The expression at protein level of MYST2 was detected by Western blotting in patients with different degrees of pathological differentiation, human normal pancreatic duct epithelial cell line HPDE, human pancreatic cancer cell lines ASPC1, BXPC3, CFPAC1 and SW1990, knockdown group, overexpression group and blank vector control group. The cell proliferation, migration, invasion and colony formation ability of the knockdown group, overexpression group and blank vector control group were determined by real-time cellular analysis, Transwell migration and invasion test, and plate colony formation assay. MYST2 immunohistochemical scoring was performed on pancreatic cancer tissues and para cancer tissues. Receiver operating characteristic curve was drawn to analyze the value of different MYST2 protein expression levels in the diagnosis of pancreatic cancer. Independent sample t test and variance analysis were used for statistical analysis. Results:Among the pathological slides of 54 cases of pancreatic cancer, 13 cases were highly differentiated, 24 cases were moderately differentiated, 15 cases were poorly differentiated and 2 cases were undifferentiated, the MYST2 expression at protein level in pancreatic cancer cells was 3.12±1.67, 2.87±1.59, 2.12±1.03 and 1.08±0.34, respectively, and the difference was statistically significant ( F=1.241, P<0.05). The MYST2 expression levels of ASPC1, BXPC3, CFPAC1 and SW1990 were all higher than that of normal pancreatic ductal epithelial cell lines HPDE (1.41±0.47, 1.40±0.93, 1.13±0.62 and 1.71±0.46 vs. 0.82±0.25), and the differences were statistically significant( t=1.625, 1.577, 1.319 and 1.832, all P<0.05). The MYST2 expression level of BXPC3 knockdown group was lower than that of BXPC3 blank vector control group (0.39±0.12 vs. 0.75±0.34); that of ASPC1 knockdown group was lower than that of ASPC1 blank vector control group (0.43±0.22 vs. 0.82±0.48); that of CFPAC1 overexpression group was higher than that of CFPAC1 blank vector control group (1.38±0.45 vs. 0.82±0.37); that of SW1990 overexpression group was higher than that of SW1990 blank vector control group (1.34±0.65 vs. 0.51±0.22), and the differences were statistically significant ( t=1.414, 1.378, 1.319 and 1.934, all P<0.05). The cell proliferation of ASPC1 knockdown group was slower than that of ASPC1 blank vector control group, and the proliferation peak at 80 h was lower than that of blank vector control group (1.02±0.77 vs. 4.31±2.45); the cell proliferation of BXPC3 knockdown group was slower than that of BXPC3 blank vector control group, and the proliferation peak at 80 h was lower than that of blank vector control group (0.91±0.24 vs. 2.84±0.53); the proliferation of pancreatic cancer cells in SW1990 overexpression group was faster than that of SW1990 blank vector control group, and the proliferation peak at 80 h was higher than that of blank vector control group (3.10±0.67 vs. 1.04±0.17); the proliferation of pancreatic cancer cells in CFPAC1 overexpression group was faster than that that of CFPAC1 blank vector control group, and the proliferation peak at 80 h was higher than that of blank vector control group (5.45±1.13 vs. 1.01±0.29), and the differences were statistically significant ( t=1.427, 1.316, 1.292 and 1.501, all P<0.05). In the test of migration ability, the number of cells passed through the Transwell chamber of ASPC1 knockdown group was less than that of ASPC1 blank vector control group (34.08±17.62 vs. 118.76±5.31); that of BXPC3 knockdown group was less than that of BXPC3 blank vector control group (18.62±9.64 vs. 57.90±12.67); that of SW1990 overexpression group was more than that of SW1990 blank vector control group (134.84±24.65 vs. 37.82±6.73); that of CFPAC1 overexpression group was more than that of CFPAC1 blank vector control group (65.79±27.46 vs. 11.68±5.13), and the differences were statistically significant ( t=1.475, 1.322, 1.437 and 1.219, all P<0.05). In the test of invasion ability, the number of cells passed through the Transwell chamber of ASPC1 knockdown group was less than that of ASPC1 blank vector control group (9.79±5.75 vs. 45.76±12.71); that of BXPC3 knockdown group was less than that of BXPC3 blank vector control group (23.46±11.13 vs. 84.92±17.65); that of SW1990 overexpression group was more than that of SW1990 blank vector control group (156.42±34.50 vs. 42.13±22.17); that of CFPAC1 overexpression group was more than that of CFPAC1 blank vector control group (112.64±47.82 vs. 39.09±17.23), and the differences were statistically significant ( t=1.324, 1.635, 1.423 and 1.119, all P<0.05). The number of colony formation of the ASPC1 knockdown group was less than that of ASPC1 blank vector control group (13.15±6.42 vs. 86.79±35.17); that of BXPC3 knockdown group was less than that of BXPC3 blank vector control group (14.93±9.30 vs. 52.93±15.76); that of SW1990 overexpression group was more than that of SW1990 blank vector control group (129.10±57.31 vs. 62.42±37.43); that of CFPAC1 overexpression group was more than that of CFPAC1 blank vector control group (157.98±66.45 vs. 74.35±34.69), and the differences were statistically significant ( t=1.148, 1.290, 1.274 and 1.462, all P<0.05). The MYST2 score of pancreatic cancer tissues was higher than that of adjacent paracancerous pancreatic tissues (3.04±2.23 vs. 1.32 ± 0.70), and the difference was statistically significant ( t=3.479, P<0.05). When the total immunohistochemistry score of MYST2 was 3 point, the area under the curve was the largest (0.888, 95% confidence interval 0.827 to 0.948), and the Youden index was 0.56. Conclusion:MYST2 is associated with the proliferation, invasion and migration of pancreatic cancer cells, and promotes the development of pancreatic cancer.

Effect of Modified Wuzi Yanzong Pill () on Tip60-Mediated Apoptosis in Testis of Male Rats after Microwave Radiation / 中国结合医学杂志

OBJECTIVE@#To investigate the effect of a modified Wuzi Yanzong Pill (, WZYZP) on the male rats' testis after microwave radiation, as well as its potential mechanism.@*METHODS@#Forty-five male rats were randomly assigned to three groups: the control group, the radiation group, and the WZYZP group. The rats in the radiation group and WZYZP group were exposed to microwave radiation for 15 min once, while the rats in the control group were not exposed to any radiation. The rats in the WZYZP group were given a modified of WZYZP by gavage daily for 7 days. Apoptosis in the testis was evaluated using terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) assay. Histopathological alterations of the testis were observed by haematoxylin-eosin (HE) staining. Tat-interactive protein, 60kD (Tip60) and p53 expressions were determined by Western blotting.@*RESULTS@#The apoptosis index (AI) in the radiation group was higher than that of the WZYZP group and control group on day 1 (D1), day 7 (D7) day 14 (D14) after radiation (P<0.05). The seminiferous tubules were of normal morphology in the control group. In the radiation group, the partial seminiferous tubules were collapsed, basement membranes of the seminiferous epithelia became detached. WZYZP could restore the morphological changes. There was no expression of Tip60 among the three groups on D7 and D14. The expression of p53 was higher in the radiation group than in the control group (P<0.05). WZYZP could down-regulate the rising p53 induced by radiation on D7 and D14 (P<0.05).@*CONCLUSION@#A modified WZYZP may affect germ cells, and its protective effects may partly result from its ability to intervene in Tip60 mediated apoptosis.

Free fatty acid-induced histone acetyltransferase activity accelerates lipid accumulation in HepG2 cells

BACKGROUND/OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is a common metabolic disease triggered by epigenetic alterations, including lysine acetylation at histone or non-histone proteins, affecting the stability or transcription of lipogenic genes. Although various natural dietary compounds have anti-lipogenic effects, their effects on the acetylation status and lipid metabolism in the liver have not been thoroughly investigated. MATERIALS/METHODS: Following oleic-palmitic acid (OPA)-induced lipid accumulation in HepG2 cells, the acetylation status of histone and non-histone proteins, HAT activity, and mRNA expression of representative lipogenic genes, including PPARγ, SREBP-1c, ACLY, and FASN, were evaluated. Furthermore, correlations between lipid accumulation and HAT activity for 22 representative natural food extracts (NExs) were evaluated. RESULTS: Non-histone protein acetylation increased following OPA treatment and the acetylation of histones H3K9, H4K8, and H4K16 was accelerated, accompanied by an increase in HAT activity. OPA-induced increases in the mRNA expression of lipogenic genes were down-regulated by C-646, a p300/CBP-specific inhibitor. Finally, we detected a positive correlation between HAT activity and lipid accumulation (Pearson's correlation coefficient = 0.604) using 22 NExs. CONCLUSIONS: Our results suggest that NExs have novel applications as nutraceutical agents with HAT inhibitor activity for the prevention and treatment of NAFLD.

Effects of cell-to-cell communication and histone acetyltransferase on the change of osteogenic differentiation ability among single-cell clones from healthy periodontium with heterogeneity of osteogenic differentiation abilities / 中华口腔医学杂志

Objective@#To investigate the effect of cell-to-cell communication amongst single-cell clones from healthy periodontium with different osteogenic differentiation potentials on change of osteogenic differentiation capabilities and the role histone acetyltransferase partaken in this process.@*Methods@#In order to research the change of osteogenic differentiation ability via cell-to-cell communication, indirect co-culture method was used by placing two single-cell clones with different osteogenesis potentials in each of the 6-well plates. Blank control, weak and strong osteogenic groups were set up, corresponding to Transwell chambers with blank, cells of weak osteogenesis ability and cells of strong osteogenesis ability, respectively. Each group was made in triplicate. After co-culture for four days, Transwell chamber was removed. Quantitative real-time PCR (qPCR) and alizarin red staining were employed to detect the change of osteogenic differentiation ability. The acetylation level of H3 was measured by using Western blotting. Histone acetyltransferases were detected by qPCR.@*Results@#Single-cell clones were ensured from mesenchymal stem cells by flow cytometer, the positive expression of CD29, CD90, CD105, CD146 was (99.80±0.02)%, (99.36±0.18)%, (99.41±0.05)% and (95.10±2.11)%, respectively. And CD31 and CD34 expression were (0.29±0.11)% and (0.22±0.13)%, respectively. Alizarin red and oil red O staining confirmed that single-cell clones had the abilities of adipogenesis and osteogenesis. Alkaline phosphatase (ALP) and alizarin red staining indicated that different single-cell clones were heterogeneity in osteogenesis differentiation. Indirect co-culture indicated that the mRNA expression of osteocalcin (OCN) were 14.24±5.60 and 4.78±2.90, respectively and Runt-related transcription factor 2 (RUNX2) were 2.75±1.44 and 1.61±0.44, respectively, in strong and weak osteogenic groups. They were significantly higher compared to the blank group (the mRNA expression of OCN and RUNX2 were 1.00±0.47 and 1.00±0.39, respectively). The expression of OCN and RUNX2 were also higher in strong osteogenic group than that in weak osteogenic group (P<0.05). The mean gray level of the acetylation of H3 in strong osteogenic group (0.76±0.09) and weak osteogenic group (0.54±0.12) were also higher than that in the blank group (0.30±0.04)(P<0.05). qPCR results showed that KAT6A in strong osteogenic group exhibiting higher expression (P<0.05) compared to weak osteogenic group and the blank group, which were corresponding to the changes of acetylation levels.@*Conclusions@#Single-cell clones from healthy periodontium showed heterogeneity in osteogenic differentiation abilities. Single-cell clones with strong osteogenesis abilities had an advantage over others by promoting others' osteogenesis differentiation and this change mediated by cell-to-cell communication might be caused by modulating KAT6A to affect the acetylation level of histone.

Identificación de genes que codifican enzimas modificadoras de aminoglucósidos en cepas intrahospitalarias de Klebsiella pneumoniae / Identification of genes encoding aminoglycoside-modifying enzymes of Klebsiella pneumoniae nosocomial isolates

Las infecciones por Klebsiella pneumoniae, constituyen un problema creciente en los centros hospitalarios. El objetivo de la presente investigación fue evaluar la resistencia a los aminoglucósidos, así como la presencia de genes que codifican enzimas modificadoras de aminoglucósidos (EMA) en aislados intrahospitalarios de Klebsiella pneumoniae. Se analizaron 56 cepas provenientes de pacientes con diagnóstico de infección intrahospitalaria del Hospital Universitario “Antonio Patricio de Alcalá”, durante el periodo enero-septiembre de 2008. Se determinó la susceptibilidad antimicrobiana mediante los métodos de difusión y dilución en agar, siguiendo los lineamientos del Instituto de Estándares Clínicos y de Laboratorio. Se empleó la técnica de la reacción en cadena de la polimerasa (PCR) para detectar los genes que codifican EMA. Se encontró resistencia a gentamicina y tobramicina en el 33,9% y 35,7%, respectivamente. Los fenotipos de resistencia a aminoglucósidos más frecuentes fueron I (ANGMKTob) y II (GMKTob). Se identificaron los genes aadA (21,4%), aac(3)-IIa (16,1%), aadB (14,3%), aac (6`)-Ib (3,6%) y aph (3`)-Ia (1,8%). En 10 cepas se observó la presencia de más de un gen y en 13 cepas se correlacionó el fenotipo con los genes encontrados. La resistencia a los aminoglucósidos en los aislados evaluados se debe, principalmente, a enzimas de tipo acetiltransferasas.

Klebsiella pneumoniae infection is a growing problem in hospitals. The objective of this study was to evaluate resistance to aminoglycosides and detection of genes encoding for aminoglycoside modifying enzymes (AME) in hospital isolates of K. pneumoniae. Fifty-six isolates from patients with diagnosis of nosocomial infection at the University Hospital Antonio Patricio de Alcala, during the period January to September 2008 were included for study. Antimicrobial susceptibility was determined by the methods of diffusion and agar dilution, following the Institute for Clinical and Laboratory Standards Guidelines. Genes encoding AME were determined by the polymerase chain reaction procedure. Resistance results for Gentamycin were 33.9% and for Tobramycin 35.7%. Aminoglycoside resistance phenotypes most frequently identified were I (ANGMKTob) and II (GMKTob). The genes involved were aadA (21.4%), aac(3)-IIa (16.1%), aadB (14.3%), aac (6`)-Ib (3.6%) y aph (3`)-Ia (1.8%) For 10 of the isolates studied more than one gene was identified. In 13 isolates the phenotype corresponded to the genes found. Aminoglycoside resistance in the isolates studied is mainly due to the presence of acetyltransferase enzymes.

Expression and clinical significance of ELOVL6 gene in high-grade serous ovarian carcinoma / 中华妇产科杂志

Objective To investigate the expression of elongation of very long-chain fatty acids family member 6 (ELOVL6) in high-grade serous ovarian carcinoma (HSOC), and explore the correlation between its expression and clinical prognosis in these patients. Methods The expression of ELOVL6 at mRNA and protein levels were respectively detected by reverse transcription (RT)-PCR and immune histochemistry method in 12 cases with normal ovarian tissues and 172 cases with HSOC from primary tumor site, forty of which had paired peritoneal metastatic tissues. Results (1) The results tested by RT-PCR showed that ELOVL6 expression in normal ovarian tissue was 4.8±1.1, while 1.2±0.7 in primary tumors and 1.8 ± 0.9 peritoneal metastatic sites in HSOC. Compared with normal ovarian tissue, the level of ELOVL6 mRNA was significantly lower in HSOC (P0.05). The total median survival was 52 months in ELOVL6-positive group and 44 months in ELOVL6-negative group (P>0.05). Conclusion Low expression of ELOVL6 may correlate with the poor differentiation and drug resistance in HSOC.

Establishment of interfering RNA library of acetyltransferase genes and its infection of HepG2.2.15 cells / 中华传染病杂志

Objective To construct lentivirus vectors carrying 16 short hairpin RNA (shRNA) expression cassettes targeting histone acetyltransferases and provide a powerful research approach to explore the mechanism of epigenetic genes in regulating hepatitis B virus (HBV).Methods Following the rule of short shRNA primer design,eight-pair primers (A ~ H )for each gene,which had stable interfering efficiency,were designed.The annealed primers were connected to the empty lentiviral vectors of shRNA for transformation.In order to confirm the positive clones,clones were analyzed by real-time polymerase chain reaction (RT-PCR ).Then, qualified plasmids were verified by enzyme digestion technology.Four shRNA lentivirus plasmids against the same gene were mixed to build lentivirus respectively.After the virus transfected into 293T cells for 48 and 72 hours,supernatants were collected to infect HepG2.2.15 cells.The percentage of fluorescent cells were observed and assessed by microscope 72 hours after infection.Results One hundred and twenty-eight lentiviral vectors of RNA interference (RNAi)library were constructed against 16 histone acetyltransferases and more than 80% of HepG2.2.15 cells were infected with lentivirus 72 hours after infection.Conclusions Sixteen shRNA lentivirus vectors against histone acetyltransferase are successfully constructed.Thus,a solid foundation for the study of the effect of human histone deacetylase on HBV replication is established.

Relationship between N-acetyltransferase-2 alleles polymorphism and type 2 diabetes mellitus / 中国医师进修杂志

Objective To explore the relationship between N-acetyltransferase-2(NAT2)alleles polymorphism and type 2 diabetes mellitus(T2DM).Methods Polymerase chain reaction and sequence determination technique were used to identify NAT2 alleles in 174 patients with T2DM(T2DM group)and 174 unrelated healthy individuals(control group).Results Compared with control group,the allelic frequency of NAT2 mutation was no significant difference in T21DM group(x2=7.38,P＞0.05).The frequencies of the NAT2 genotypes(Wt/Wt,Wt/M1,Wt/M2,Wt/M3,M1/M1,M1/M2,M1/M3,M2/M2,M2/M3,M3/M3)were 39.08％(68/174),3.45％(6/174),22.99％(40/174),14.94％(26/174),0.57％(1/174),2.30％(4/174),1.15％(2/174),4.60％(8/174),9.20％(16/174),1.72％(3/174)and 44.83％(78/174),2.60％(8/174),27.59％(48/174),17.24％(30/174),0.57％(1/174),0.57％(1/174),0.57％(1/174),1.15％(21174),2.30％(4/174),0.57％(1/174)respectively,and significant differences showed between T2DM group and control group(x2=13.92,P＜0.01).The proportion of fast acetylate in T2DM group was significantly higher than that in control group[94.25％(164/174)vs.80.46％(140/174)],and the propoaion of slow acetylate in T2DM group was significantly lower than that in control group[5.75％(10/174)vs.19.54％(34/174)](P＜0.05),The risk of T2DM in people who were fast acetylate had 3.98 times(95％ CI:1.90-8.35)more than that in people who were slow acetylate.Conclusion It shows that the fast acetylate may be one of the genetic factors that influencing the susceptibility to T2DM,and slow acetylate may be one of the protecting factors.

The biological characteristics of p300/CBP-associated factor and relationship with disease / 国际儿科学杂志

p300/CBP-associated factor (PCAF)is an important histone acetyltransferase in eukaryotic cells. PCAF can acetylizes histone and non-histone. PCAF participates in various biological processes of cells and in the interaction between virus and cells. The imbalance of PCAF would lead to abnormal development of various organs, and related to the development of some tumors.

The Histone Acetyltransferase hMOF is Overexpressed in Non-small Cell Lung Carcinoma

BACKGROUND: One of the histone acetyltransferases (HATs) family of proteins, human MOF (hMOF, MYST1), is involved in histone H4 acetylation, particularly at lysine 16 (H4K16Ac), an epigenetic mark of active genes. Dysregulation of the epigenetic mark influences cellular biology and possibly leads to oncogenesis. We examined the involvement of hMOF and H4K16Ac in primary non-small cell lung cancer (NSCLC). METHODS: Reverse transcription polymerase chain reaction using fresh-frozen lung cancer tissues and lung cancer cell lines and immunohistochemistry for hMOF and H4K16Ac via tissue microarray of 551 formalin-fixed paraffin-embedded NSCLC tissue blocks were conducted. RESULTS: hMOF mRNA was frequently overexpressed in lung cancer tissues, compared with normal lung tissues (10/20, 50%). NSCLC tissues were positive for hMOF in 37.6% (184/489) and H4K16Ac in 24.7% (122/493) of cases. hMOF protein expression was tightly correlated with the H4K16Ac level in tumors (p<0.001). Knockdown of hMOF mRNA with siRNA led to a significant inhibition of growth in the Calu-6 cell line. CONCLUSIONS: hMOF was frequently expressed in NSCLC and was correlated with H4K16Ac. To our knowledge, this is the first study that has focused on the expression status of HATs and hMOF in NSCLC. Our results clearly suggest a potential oncogenic role of the gene and support its utility as a potential therapeutic target.

The relationship between polymorphisms of N-acetyltransferase 2 genes and anti-tuberculosis drug induced hepatic-injury / 中华传染病杂志

Objective To investigate the relationship between polymorphisms of N-acetyltransferase 2(NAT2)genes and anti-tuberculosis drug induced hepatic-injury(ADIH).Methods A 1:1 matched case-control study was conducted.One hundred and six cases fulfilling the criteria of ADIH were selected as ADIH group from the patients who received anti-tuberculosis therapy.whereas those patients without any hepatic inj ury related elinical symptoms during three months of follow-up period were selected as control.The genetic polymorphisms of the loci,NAT2481C/T,NAT2-590G/A and NAT2-857G/A,were determined by polymerase chain reaction and restriction fragment length polymorphism technique(PCR-RFLP)in patients who received antituberculosis therapy.The major environmental factors and genotypes were analyzed by univariate and multivariate conditional Logistic analyses.Results The T,AA allele frequencies of NAT2-481C/T,NAT2-590G/A and NAT2-857G/A were 7.5%,28.8%and 17.9%respectively in ADIH group,and 6.6%,18.9%and 17.5%,respectively in the control group.Univariate analysis demonstrated that the frequency of NAT2 slow acetylation genotype in ADIH group was significantly higher than that in control group with a crude OR(95%CI)of 2.250(1.140-4.441).Among 6 potential risk factors,i.e.education level,occupation,body mass index(BMI),smoking,drinking and the type of tuberculosis,the low BMI and drinking were two risk factors for ADIH.In multivariate analysis,ADIH remained associated with acetylation genotype after adjusting for BMI and drinking status.The adjusted OR(95%CI)was 2.246(1.086-4.644).Conclusion NAT2 slow acetylation genotype may be associated with the occurrence of ADIH.

Spatiotemporal expression patterns of histone acetyltransferase steroid receptor coactivator-1 in developing mouse heart / 第二军医大学学报

Objective: To study the spatiotemporal expression pattern of histone acetyltransferase steroid receptor coactivator-1 (SRC1) in developing mouse heart, so as to explore the relationship of SRC1 with heart development. Methods: The normal mouse hearts were collected at E7.5-E18 and 1 day and 3 months after birth; 9 specimens were chosen for each time point to observe the spatial expression of SRC1 by immunohistochemistry technique, and 6 specimens of each time point were used to examine the temporal expression of SRC1 protein by Western blotting technique and to plot the time-dose curve. Results Immunohistochemistry showed no expression of SRC1 in the heart primordium at E7.5; only very weak SRC1 expression was found in the cardiac tube at E8. 5-E9.5. Weak SRC1 expression was found in the trabeculae after E10.5 and relatively strong and widespread expression was found in other heart regions. Western blotting results demonstrated that SRC1 protein expression at E10.5 was significantly lower than those at E11.5 and E12.5 (P0.05). SRC1 expression reached the peak at E11. 5-E12.5, and there was no significant difference between the two time points (P>0.05). SRC1 expression gradually decreased after Ell. 5-E12.5 till the adulthood, and there were no significant differences in the expression after E13.5 (P>0.05). Conclusion: Widespread distribution of SRCl is present in the developing mouse heart after ES. 5, and the expression is in a dynamical spatiotemporal pattern, suggesting that SRC1 may take part in the overall regulation of the heart development, and it might has a closer relationship with the early induction of the heart septa.

Repression of TNF-alpha-induced IL-8 expression by the glucocorticoid receptor-beta involves inhibition of histone H4 acetylation

Increased expression of a number of proinflammatory genes, including IL-8, is associated with inflammatory conditions such as asthma. Glucocorticoid receptor (GR)beta, one of the GR isoforms, has been suggested to be upregulated in asthma associated with glucocorticoid insensitivity and to work as a dominant negative inhibitor of wild type GRalpha. However, recent data suggest that GRbeta is not a dominant negative inhibitor of GRalpha in the transrepressive process and has its own functional role. We investigated the functional role of GRbeta expression in the suppressive effect of glucocorticoids on tumor necrosis factor (TNF)-alpha-induced IL-8 release in an airway epithelial cell line. GRbeta expression was induced by treatment of epithelial cells with either dexamethasone or TNF-alpha. GRbeta was able to inhibit glucocorticoid-induced transcriptional activation mediated by binding to glucocorticoid response elements (GREs). The suppressive effect of dexamethasone on TNF-alpha-induced IL-8 transcription was not affected by GRbeta overexpression, rather GRbeta had its own weak suppressive activity on TNF-alpha-induced IL-8 expression. Overall histone deacetylase activity and histone acetyltransferase activity were not changed by GRbeta overexpression, but TNF-alpha-induced histone H4 acetylation at the IL-8 promoter was decreased with GRbeta overexpression. This study suggests that GRbeta overexpression does not affect glucocorticoid-induced suppression of IL-8 expression in airway epithelial cells and GRbeta induces its own histone deacetylase activity around IL-8 promoter site.

Repression of TNF-alpha-induced IL-8 expression by the glucocorticoid receptor-beta involves inhibition of histone H4 acetylation

Increased expression of a number of proinflammatory genes, including IL-8, is associated with inflammatory conditions such as asthma. Glucocorticoid receptor (GR)beta, one of the GR isoforms, has been suggested to be upregulated in asthma associated with glucocorticoid insensitivity and to work as a dominant negative inhibitor of wild type GRalpha. However, recent data suggest that GRbeta is not a dominant negative inhibitor of GRalpha in the transrepressive process and has its own functional role. We investigated the functional role of GRbeta expression in the suppressive effect of glucocorticoids on tumor necrosis factor (TNF)-alpha-induced IL-8 release in an airway epithelial cell line. GRbeta expression was induced by treatment of epithelial cells with either dexamethasone or TNF-alpha. GRbeta was able to inhibit glucocorticoid-induced transcriptional activation mediated by binding to glucocorticoid response elements (GREs). The suppressive effect of dexamethasone on TNF-alpha-induced IL-8 transcription was not affected by GRbeta overexpression, rather GRbeta had its own weak suppressive activity on TNF-alpha-induced IL-8 expression. Overall histone deacetylase activity and histone acetyltransferase activity were not changed by GRbeta overexpression, but TNF-alpha-induced histone H4 acetylation at the IL-8 promoter was decreased with GRbeta overexpression. This study suggests that GRbeta overexpression does not affect glucocorticoid-induced suppression of IL-8 expression in airway epithelial cells and GRbeta induces its own histone deacetylase activity around IL-8 promoter site.

The mechanism study of plasmid-mediated quinolone resistance in clinical isolates of Enterobacteriaceae from nine teaching hospitals in China / 中华检验医学杂志

Objective To investigate the prevalence of plasmid-mediated quinolone resistance qnr and aac(6')-Ib-cr in Enterobacteriaceac in Chiha.Methods A total of 197 clinical isolates with ciprofloxacin≥0.25μg/ml,cefotaxime≥2.0μg/ml and ceftriaxone≥2.0 μg/ml were screened from the 421 non-repetitive clinical isolates of Enterobac teriaceae(Escherichia coli,Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae)from the nine teaching hospitals in China.qnrA,qnrB,qnrS and aac(6')-Ib gene were detected by PCR.aac(6')-Ib-cr gene was further identified by the digestion with BtsCI followed by sequencing.Conjugation experiments were done.The MIC of ciprofloxacin and other antibacterial agents in donor strain and acceptor strain were determined by agar dilution.Results Qnr was present in 42%(83/197)of isolares,and among these,17 isolates carried qnrA(9%),46 isolates carried qnrB(23%),24 isolates carried qnrS(12%),2 isolates carried qnrA and qnrB,and 2 isolates carried qnrB and qnrS.aac(6')-Ib was present in 46%(90/197)of isolates,40%(36/90)of which carried the cr variant responsible for low-level ciprofloxacin resistance.18 isolates carried qnr and aac(6')-Ib-cr.Qnr wag present in 66% of Enterobacter cloacae isolates,66% of Klebsiella pneumoniae isolates,63% of Citrobacter freundii isolates,and 6% of Escheriehia coil isolates,respectively,aac(6')-Ib-cr was present in 9% of Enterobacter cloacae isolates,22% of Klebsiella pneumoniae isolates,27% of Citrohacter freundii isolates,and 17% of Escherichia coil isolates,respectively,qnr and aac(6')-Ib-cr were present in 20% (83/421)and 9% (36/421) of all isolates respectively. The 13 transconjugants showed 16 to 125 fold increases in the MICs of ciprofloxacin and 16 to 31 fold increases in the MICs of levofloxacin relative to that of the recipient Conclusion Transferable plasmid-medlated low level quinolone resistance associated with qnr and aac(6')-Ib-cr widely exists in the enterobacteriaceae strains and perhaps this may contribute to the rapid increase of bacterial resistance to quinolones in China.

Prevalence of aac(6')-Ib-cr in clinical isolates of Klebsiella pneumoniae / 中华检验医学杂志

Objective To investigate the prevalence of aac(6')-Ib-cr in clinical isolates of Klebsiella pneumoniae.Methods A total of 337 isolates of Klebsiella pneumoniae were isolated from clinical specimens in our hospital from Jan,2006 to Sep,2007.Gentamycin,amikacin or tobramicin was used to screen the isolated with aac(6')-Ib-cr.aac(6')-Ib and class 1 interase gene(intl1)was determined by PcR All PCR products of aac(6')-Ib were sequenced for determination of aac(6')-Ib-cr. MICs of antibiotics were determined by agar dilution method.The ESBLs-producing isolates were determined by the CLSI-recommended confirmatory tests.Conjugation test was used to detect the transfer of plasmid.Results Of the 337 clinical isolates of Klebsiella pneumoniae,64(19.0%),28(8.3%)and 55(16.3%)isolates were resistant to gentamycin,amikacin and tobramycin,respectively.Among 64 gentamycin-resistant isolates,24(37.5%)were positive for aac(6')-Ib-cr,including 13 ciprofloxacin-resistant isolates and 11 ciprofloxacinsusceptible isolates.The prevalence of aac(6')-Ib-cr in ciprofloxacin-resistant and-susceptible isolates were 54.2%(13/24)and 27.5%(11/40).The positive rates of ESBLs and intl1 in the 24 isolates carrying aac(6')-Ib-cr were 79.2%(19/24)and 91.7%(22/24).Plasmids carrying aac(6')-Ib-cr of 13 isolates were successfully transferred to E.coli J53.Plasmids of all transconjugants were positive for aac(6')-Ib-cr and intl1.All transconjugants were ESBL producing strains.Conclusions aac(6')-Ib-cr exists widely in clinical isolates of Klebsiella pneumoniae.aac(6')-Ib-cr and ESBL gene usually coexist in a selftransmissible conjugative plasmid by class 1 integron.

A Simple Reliable Fluorescent Assay Method for Histone Acetyltransferase (HAT) Inhibitors / 生物化学与生物物理进展

Histone acetyltransferases (HATs) are involved in the regulation of gene transcription in eukaryotic cells and their inhibitors could be a promising class of drugs due to their ability to modulate transcription and exert antiviral, anti-inflammatory as well as antioxidant effects. Nonradioactive spectrophotometric HAT assay is an alternative method to the widespread radioactive assay but suffers from drawbacks as lack of sensitivity and accuracy. A simple, non-radioactive fluorescent assay that measures the production of CoASH was established by its facile reaction with O-phthalaldehyde and 2-amino-ethanol. This method gives much higher accuracy compared to spectrophotometric assay, and allows screening of various compounds with potential HAT inhibition. The novel assay should be a valuable tool in transcriptional research and especially drug discovery.

Expression of the RERG Gene is Gender-Dependent in Hepatocellular Carcinoma and Regulated by Histone Deacetyltransferases

Ras-related, estrogen-regulated, and growth-inhibitory gene (RERG) is a novel gene that was first reported in breast cancer. However, the functions of RERG are largely unknown in other tumor types. In this study, RERG expression was analyzed in hepatocellular carcinomas of human patients using reverse transcriptase PCR analysis. In addition, the possible regulation of RERG expression by histone deacetyltransferases (HDACs) was studied in several cell lines. Interestingly, the expression of RERG gene was increased in hepatocellular carcinoma (HCC) of male patients (57.9%) but decreased in HCC of females (87.5%) comparison with paired peri-tumoral tissues. Moreover, RERG gene expression was increased in murine hepatoma Hepa1-6 cells, human breast tumor MDA-MB-231 cells, and mouse normal fibroblast NIH3T3 cells after treated by HDAC inhibitor, trichostatin A. Our results suggest that RERG may function in a gender-dependent manner in hepatic tumorigenesis and that the expression of this gene may be regulated by an HDAC-related signaling pathway.

Screening and identification of interaction proteins of human TIP60? by yeast two- hybrid system / 第三军医大学学报

Objective To construct a yeast expression vector containing human TIP60? gene (a spliced form of HIV-1 tat interactive protein,HTATIP,60?103) and screen its interaction proteins by yeast two-hybrid. Methods Human TIP60? gene fragment was amplified by RT-PCR and cloned into pGBKT7 vector. Using TIP60? as bait,the proteins interacting with TIP60? were screened from a human liver cDNA library. The positive clones were analyzed by bioinformatic methods. Results Human TIP60? cDNA was successfully amplified and cloned into the pGBKT7 vector and indentified by double enzyme digestion and DNA sequencing. Using yeast two-hybrid,32 clones were screened from a human liver cDNA library,and 9 positive clones including histone deacetylase 7A (HDAC7A),mouse double minute 2 (DMD2),B-cell CLL/lymphoma 3 (BCL3),endothelin receptor type A (EDNRA),androgen receptor (AR),PHD finger protein 17 (PHF17),Ataxia Telangiectasia Mutated (ATM),CAMP responsive element binding protein 1 (CREB1),orphan steroid receptor BD73 were verified after sequencing. Conclusion The screened interaction proteins with TIP60? by yeast two-hybrid may be involved in the roles of transcriptional regulation of TIP60?.

Correlation between phenotype and polymorphism of Chinese Han's gene encoding N-acetyltransferase 1 / 中国药理学通报

Aim To establish the method of detecting the Arylamine N-acetyltransferase-1(NAT1) genotype and its distribution of polymorphism,and analyze the correlation between the genotype and the phenotype in a Chinese Hans population.Methods The peripheral blood samples from 140 Han people were collected and analyzed for NAT1 genotypes by multiple PCR and PCR-RFLP method.The NAT1 enzyme kinetics in leukocytes in 32 persons with different genotypes from 140 Han people,were determinated for NAT1 phenotype by HPLC,the values of intrinsic clearance(Clint) and V_(max) and Michaelis constant(K_m) of NAT1 were calculated for evaluation of para-aminobenozic acid as a specific substrate.Results The NAT1 genotype of Chinese Hans population was distinguished accurately by multiple PCR and PCR-RFLP methods,and was not interfered by the interaction of several restriction endonucleases.The allelic frequencies of NAT1~*3,NAT1~*4,NAT1~*10 and NAT1~*11 from 140 Han people,were 0.082,0.496,0.40 and 0.022,respectively.The frequency of NAT1~*4 allele was significantly lower than that of Caucasian populations,but higher than that of Southeast Asia and African.Frequencies of NAT1~*3 and NAT1~*11 allele were comparable with those of many Asian populations,but the frequency of NAT1~*10 allele was higher than that of in Europe and America populations.Compared with the activity of wild genotype NAT1 ~*4/~*4,activities of the homozygote or heterozygote NAT1~*10 genotypes which include the NAT1 ~*4/~*10,the NAT1 ~*10/~*10 and the NAT1 ~*10/~*3 were higher significantly(P