Detección de macroenzimas después de la precipitación con polietilenglicol: búsqueda de la población de referencia en el caso particular de las aminotransferasas / Detection of macroenzymes for aminotransferases after polyethylene glycol precipitation: search for the reference population / Detecção de macroenzimas após a precipitação com polietilenoglicol: busca da população de referência no caso particular das aminotransferases

Resumen Las macroenzimas son complejos de elevado peso molecular que podrían incrementar la actividad enzimática sérica en ausencia de signos y síntomas. Se pueden detectar al ser precipitadas con polietilenglicol. El objetivo del trabajo fue determinar la actividad de las aminotransferasas por el método IFCC, calcular y comparar la media del porcentaje de actividad precipitable (x̄), su intervalo de confianza del 95% (IC95%) y el desvío estándar (DE). Se trabajó con individuos con (n=42) y sin hipertransaminasemia (n=22). Los resultados para uno y otro fueron: porcentaje de actividad precipitable con polietilenglicol (%PPA) (x̄, DE, IC95%) = (28%; 1,82; 27,45%-28,55% y 44%; 24,52; 32,84%-55,16%) y (15%; 13,03; 11,01%-18,99% y 25%; 9,1; 20,96%-29,04%) para ALT y AST, respectivamente (p=0,003 y p=0,001; p<0,05). En conclusión, la estimación de la media poblacional podría ser más precisa en individuos con hipertransaminasemia.

Abstract Macroenzymes are high-molecular-mass complexes that might increase the serum enzymatic activity in the absence of symptoms. An easy-touse method to detect them is the polyethylene glycol precipitation. The aim of this study was to determine aminotransferases activity using the IFCC method, and to calculate the mean percentage of precipitable activity (x̄), its 95% confidence interval (CI95%), and the standard deviation (SD). The study included individuals with (n=42) and without hypertransaminasemia (n=22). The results were: percentaje of precipitable activity (%PPA) (x̄, SD, CI95%) = (28%; 1.82; 27.45%-28.55% and 44%; 24.52; 32.84%-55.16%) and (15%; 13.03; 11.01%-18.99% and 25%; 9.1; 20.96%-29.04%) for ALT and AST, respectively (p=0.003 and p=0.001; p<0.05). In conclusion, the estimation of the population mean could be more precise in individuals with hypertransaminasemia.

Resumo As macroenzimas são complexos de alto peso molecular que poderiam aumentar a atividade enzimática sérica na ausência de sinais e sintomas. Podem ser detectadas ao precipitar com polietilenoglicol. O objetivo do trabalho foi determinar a atividade das aminotransferases pelo método IFCC, calcular e comparar a média da porcentagem de atividade precipitável (x̄), seu intervalo de confiança de 95% (IC95%) e o desvio padrão (DP). O trabalho foi realizado com indivíduos com (n=42) e sem hipertransaminasemia (n=22). Os resultados para os dois foram: porcentagem de atividade precipitável com polietilenoglicol (%PPA) (x̄, DP, IC95%)=(28%; 1,82; 27,45%- 28,55% e 44%; 24,52; 32,84%- 55,16%) e (15%; 13,03; 11,01%-18,99% e 25%; 9,1; 20,96%-29,04%) para ALT e AST, respectivamente (p=0,003 e p=0,001; p<0,05). Concluindo, a estimativa da média populacional poderia ser mais precisa em indivíduos com hipertransaminasemia.

Screening of UBE2S interacting protein and construction of prognostic model in hepatocellular carcinoma / 吉林大学学报(医学版)

Objective:To screen the interacting protein of ubiquitin-conjugating enzyme E2S(UBE2S)and construct the hepatocellular carcinoma(HCC)based on UBE2S interacting protein prognosis model(UIPM),and to discuss the value of UIPM in assessing the prognosis of the HCC patients.Methods:Co-immunoprecipitation(Co-IP)was used to screen the protein complexes binding to Flag-UBE2S.After validation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE)and Western blotting methods;liquid chromatography-mass spectrometer(LC-MS)was used to identify the UBE2S interacting proteins;Gene Ontology(GO)functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway enrichment analysis were conducted on these proteins;the prognosis-related proteins from The Cancer Genome Atlas(TCGA)were cross-referenced with UBE2S interacting proteins by survival package of R software;the key proteins were extracted through LASSO regression analysis to build the UIPM;the prognostic model risk scoring formula was established.The HCC patients in TCGA were divided into high risk group and low risk group based on median value of the risk scores.The predictive accuracy of UIPM was evaluated by receiver operating characteristic curve(ROC),and the predictive accuracy was further validated by International Cancer Genome Consortium(ICGC)Database;univariate regression analysis and multivariate Cox regression analysis were used to detect whether the UIPM risk score was an independent prognostic factor for HCC.Furthermore,the nomogram model was built.Results:A total of 97 UBE2S interacting proteins were identified through Co-IP combined with LC-MS analysis.The GO functional enrichment analysis and KEGG signaling pathway enrichment analysis results showed that the interacting proteins were closely associated with cysteine-type endopeptidase activity,oxidative stress,and cell death.The TCGA revealed 5 163 HCC prognosis-related proteins;after intersecting with UBE2S interacting proteins,40 prognosis-related interacting proteins were found.Seven key proteins were determined through LASSO regression analysis,including UBE2S,heat shock protein family A member 8(HSPA8),heterogeneous nuclear ribonucleoprotein H1(HNRNPH1),chaperonin containing TCP1 subunit 3(CCT3),eukaryotic translation initiation factor 2 subunit 1(EIF2S1),receptor for activated C kinase 1(RACK1),and actin related protein 2/3 complex subunit 4(ARPC4),and the UIPM was constructed.There was significant difference in survival rate of the patients between high risk group and low risk group(P<0.05).The ROC curve analysis results showed the area under ROC curve(AUC)values of UIPM for predicting 1-year,2-year,and 3-year survival risk scores of the HCC patients were all greater than 0.7,indicating the model had high predictive accuracy.This was also confirmed by ICGC Database data.The univariate and multivariate Cox regression analysis results showed that the UIPM risk score was an independent prognostic risk factor for the HCC patients(P<0.05).The nomogram results showed good consistency between predicted survival rate and actual survival rate of the patient.Conclusion:A total of 97 interacting proteins that interact with UBE2S may promote the occurence and devolopment of HCC through oxidative stress and dysregulation of ferroptosis pathways.The UIPM risk score is an independent risk factor for the prognosis of HCC and can be used to predict the outcomes of the patients.UBE2S,HSPA8,HNRNPH1,CCT3,EIF2S1,RACK1,and ARPC4 could be regarded as the new biomarkers and therapeutic targets for HCC.

Expression pattern and signification of Cx43,beta-catenin and Smo in the second heart field / 中国组织工程研究

BACKGROUND:The second heart field is crucial for the development of the embryonic heart.Abnormal development of the second heart field can result in multiple cardiac malformations.After Cx43 gene knockout,reduced formation and proliferation of cells of the second heart field can be observed,but the specific reason remains unclear. OBJECTIVE:(1)To determine whether β-catenin,Smo and Cx43 were co-expressed in the second heart field and the endoderm,we observed the expression patterns of these proteins.(2)To explore whether Cx43 interacts with the Wnt/β-catenin pathway or the Shh pathway in the development of the second heart field. METHODS:Serial paraffin sections of the mouse embryos at embryonic days 10-12 were selected for immunohistochemical staining,hematoxylin-eosin staining and immunofluorescence staining.The primitive gut of mouse embryos at embryonic day 11 was separated for western blot assay and co-immunoprecipitation. RESULTS AND CONCLUSION:(1)Cx43 and Isl1 were co-expressed in some mesenchymal cells on the ventral side of the foregut and dorsal wall of the pericardial cavity of mouse embryos at embryonic days 10-12;Isl1 positive cells increased while Cx43 positive cells increased.(2)Cx43 and β-catenin were co-expressed in the ventral part of the endoderm at embryonic days 10-12.(3)Cx43 and Smo were co-expressed in the endoderm at embryonic days 10-12.(4)The co-immunoprecipitation results confirmed that there was an interaction between Cx43 and β-catenin,which suggested that Cx43 interacted with β-catenin to participate in the development of the second heart field.

Principle and Application of Ultraviolet Crosslinking Immunoprecipitation Technology / 生物化学与生物物理进展

The UV cross-linking immunoprecipitation (CLIP) technique was first established in 2003. Sequences of target RNAs and binding sites of specific RNA-binding proteins (RBPs) were identified within the entire transcriptome by UV cross-linking, immunoprecipitation, reverse transcription, and subsequent high-throughput sequencing. Over the last 20 years, CLIP has been continuously modified and improved. Advanced operability and accuracy have extended its application category. Currently, the widely used CLIP technologies include high-throughput sequencing with crosslinking-immunoprecipitation (HITS-CLIP), photoactivatable-ribonucleoside-enhanced CLIP (PAR-CLIP), individual nucleotide resolution CLIP (iCLIP), enhanced CLIP (eCLIP), infrared-CLIP (irCLIP), etc. HITS-CLIP combines high-throughput sequencing with UV cross-linking immunoprecipitation. The 254 nm UV cross-linking and RNAase digestion steps allow the technology to capture transient intracellular RBP-RNA interactions. However, there are limitations in the efficiency of UV cross-linking, with low resolution and high intrinsic background noise. For PAR-CLIP, photoactivatable ribonucleoside was incorporated into RNA molecules, and RBP cross-linked with RNA by 365 nm UV light to improve cross-linking efficiency and resolution. Cross-linking mediated single-base mutations provide more accurate binding site information and reduce interference from background sequences. Long-term alternative nucleotide incorporation, on the other hand, can be cytotoxic and may skew experimental results. iCLIP can identify RBP-RNA cross-linking sites at the single nucleotide level through cDNA circularization and subsequent re-linearization steps, but it has more experimental procedures, and partial cDNAs lost in the circularization step are inevitable. eCLIP discards the radioisotope labeling procedure and reduces RNA loss by ligating adaptors in two separate steps, greatly improving the library-building efficiency, and reducing bias associated with PCR amplification; however, the efficiency of immunoprecipitation cannot be visually assessed at the early stage of the experiment. The irCLIP technique replaces radioisotopes with infrared dyes and greatly reduces the initial number of cells required for the experiment; however, an infrared imaging scanner is essential for the irCLIP application. To address more particular scientific issues, derivative CLIP-related techniques such as PAPERCLIP, cTag-PAPERCLIP, hiCLIP, and tiCLIP have also been developed in recent years. In practice, the aforementioned CLIP approaches have their advantages and disadvantages. When deciding on a technical strategy, we should take into account our experimental objectives and conditions, such as whether we need to precisely define the RNA site for binding to RBP; whether we have the necessary experimental conditions for working with radioisotopes or performing infrared imaging; the amount of initial sample size, and so on. In addition, the CLIP technique has a relatively large number of procedures and can be divided into several successive experimental modules. We can try to combine modules from different mainstream CLIP technologies to meet our experimental requirements, which also gives us more opportunities to improve and refine them and to build more targeted derivative CLIP technologies according to our research objectives.

Map of benzoapyrene metabolites-DNA adducts in human bronchial epithelial-like cells: Based on chromatin immunoprecipitation followed by sequencing technology / 环境与职业医学

Background The active metabolite of benzo[a]pyrene (BaP), 7,8-dihydroxy-9,10-epoxybenzo[a]pyrene (BPDE), can form adducts with DNA, but the spectrum of BPDE-DNA adducts is unclear. Objective To identify the distribution of BPDE adduct sites and associated genes at the whole-genome level by chromatin immunoprecipitation followed by sequencing (ChIP-Seq), and serve as a basis for further exploring the toxicological mechanisms of BaP. Methods Human bronchial epithelial-like cells (16HBE) were cultured to the fourth generation inthe logarithmic growth phase. Cells were harvested and added to chromatin immunoprecipitation lysis buffer. The lysate was divided into experimental and control groups. The experimental group received a final concentration of 20 μmol·L−1 BPDE solution, while the control group received an equivalent volume of dimethyl sulfoxide solution. The cells were then incubated at 37 °C for 24 h. Chromatin fragments of 100-500 bp were obtained through sonication. BPDE-specific antibody (anti-BPDE 8E11) was used to enrich DNA fragments with BPDE adducts. High-throughput sequencing was conducted to detect BPDE adduct sites. The top 1000 peak sequences were subjected to motif analysis using MEME and DREME software. BPDE adduct target genes at the whole-genome level were annotated, and Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of BPDE adduct target genes were conducted using bioinformatics techniques. Results The high-throughput sequencing detected a total of 842 BPDE binding sites, distributed across various chromosomes. BPDE covalently bound to both coding and non-coding regions of genes, with 73.9% binding sites located in intergenic regions, 19.6% in intronic regions, and smaller proportions in upstream 2 kilobase, exonic, downstream 2 kilobase, and 5' untranslated regions. Regarding the top 1000 peak sequences, four reliable motifs were identified, revealing that sites rich in adenine (A) and guanine (G) were prone to binding. Through the enrichment analysis of binding sites, a total of 199 BPDE-adduct target genes were identified, with the majority located on chromosomes 1, 5, 7, 12, 17, and X. The GO analysis indicated that these target genes were mainly enriched in nucleic acid and protein binding, participating in the regulation of catalytic activity, transport activity, translation elongation factor activity, and playing important roles in cell division, differentiation, motility, substance transport, and information transfer. The KEGG analysis revealed that these target genes were primarily enriched in pathways related to cardiovascular diseases, cancer, and immune-inflammatory responses. Conclusion Using ChIP-Seq, 199 BPDE adduct target genes at genome-wide level are identified, impacting biological functions such as cell division, differentiation, motility, substance transport, and information transfer. These genes are closely associated with cardiovascular diseases, tumors, and immune-inflammatory responses.

Effects of host proteins interacting with non-structural protein nsp9 of porcine epidemic diarrhea virus on viral replication / 生物工程学报

Porcine epidemic diarrhea virus (PEDV) is a highly pathogenic virus that can cause acute intestinal infectious diseases in both piglets and fattening pigs. The virus encodes at least 16 non-structural proteins, including nsp9, which has been shown to bind to single-stranded RNA. However, its function and mechanism remain unclear. In this study, we aimed to identify potential host proteins that interact with PEDV nsp9 using immunoprecipitation combined with mass spectrometry. The interactions were then confirmed by co-immunoprecipitation (Co-IP) and confocal laser scanning fluorescence techniques. The results showed that nsp9 interacts with HSPA8, Tollip, HSPA9 and TOMM70. Among them, overexpression of HSPA8 resulted in caused first upregulated and then down-regulated expression of nsp9, and promoted the proliferation of PEDV. Overexpression of Tollip significantly upregulated the expression of nsp9 and inhibited the proliferation of PEDV. Overexpression of TOMM70 significantly reduced the expression of nsp9, but did not show significant effect on the proliferation of PEDV. Overexpression of HSPA9 did not show significant effect on the expression of nsp9 and the proliferation of PEDV. These findings may facilitate further investigating the role of nsp9-interacting proteins in PEDV infection.

Peroxidase from foxtail millet bran exerts anti-colorectal cancer activity via targeting cell-surface GRP78 to inactivate STAT3 pathway

Molecular targeted therapy has become an emerging promising strategy in cancer treatment, and screening the agents targeting at cancer cell specific targets is very desirable for cancer treatment. Our previous study firstly found that a secretory peroxidase of class III derived from foxtail millet bran (FMBP) exhibited excellent targeting anti-colorectal cancer (CRC) activity in vivo and in vitro, whereas its underlying target remains unclear. The highlight of present study focuses on the finding that cell surface glucose-regulated protein 78 (csGRP78) abnormally located on CRC is positively correlated with the anti-CRC effects of FMBP, indicating it serves as a potential target of FMBP against CRC. Further, we demonstrated that the combination of FMBP with the nucleotide binding domain (NBD) of csGRP78 interfered with the downstream activation of signal transducer and activator of transcription 3 (STAT3) in CRC cells, thus promoting the intracellular accumulation of reactive oxygen species (ROS) and cell grown inhibition. These phenomena were further confirmed in nude mice tumor model. Collectively, our study highlights csGRP78 acts as an underlying target of FMBP against CRC, uncovering the clinical potential of FMBP as a targeted agent for CRC in the future.

WSB1 regulates c-Myc expression through β-catenin signaling and forms a feedforward circuit

The dysregulation of transcription factors is widely associated with tumorigenesis. As the most well-defined transcription factor in multiple types of cancer, c-Myc can transform cells by transactivating various downstream genes. Given that there is no effective way to directly inhibit c-Myc, c-Myc targeting strategies hold great potential for cancer therapy. In this study, we found that WSB1, which has a highly positive correlation with c-Myc in 10 cancer cell lines and clinical samples, is a direct target gene of c-Myc, and can positively regulate c-Myc expression, which forms a feedforward circuit promoting cancer development. RNA sequencing results from Bel-7402 cells confirmed that WSB1 promoted c-Myc expression through the β-catenin pathway. Mechanistically, WSB1 affected β-catenin destruction complex-PPP2CA assembly and E3 ubiquitin ligase adaptor β-TRCP recruitment, which inhibited the ubiquitination of β-catenin and transactivated c-Myc. Of interest, the effect of WSB1 on c-Myc was independent of its E3 ligase activity. Moreover, overexpressing WSB1 in the Bel-7402 xenograft model could further strengthen the tumor-driven effect of c-Myc overexpression. Thus, our findings revealed a novel mechanism involved in tumorigenesis in which the WSB1/c-Myc feedforward circuit played an essential role, highlighting a potential c-Myc intervention strategy in cancer treatment.

Long non-coding RNA SAP30-2:1 is downregulated in congenital heart disease and regulates cell proliferation by targeting HAND2 / 医学前沿

Congenital heart disease (CHD) is the most common birth defect worldwide. Long non-coding RNAs (lncRNAs) have been implicated in many diseases. However, their involvement in CHD is not well understood. This study aimed to investigate the role of dysregulated lncRNAs in CHD. We used Gene Expression Omnibus data mining, bioinformatics analysis, and analysis of clinical tissue samples and observed that the novel lncRNA SAP30-2:1 with unknown function was significantly downregulated in damaged cardiac tissues from patients with CHD. Knockdown of lncRNA SAP30-2:1 inhibited the proliferation of human embryonic kidney and AC16 cells and decreased the expression of heart and neural crest derivatives expressed 2 (HAND2). Moreover, lncRNA SAP30-2:1 was associated with HAND2 by RNA immunoprecipitation. Overall, these results suggest that lncRNA SAP30-2:1 may be involved in heart development through affecting cell proliferation via targeting HAND2 and may thus represent a novel therapeutic target for CHD.

SMYD3-PARP16 axis accelerates unfolded protein response and mediates neointima formation

Neointimal hyperplasia after vascular injury is a representative complication of restenosis. Endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) is involved in the pathogenesis of vascular intimal hyperplasia. PARP16, a member of the poly(ADP-ribose) polymerases family, is correlated with the nuclear envelope and the ER. Here, we found that PERK and IRE1

Pharmacologically targeting molecular motor promotes mitochondrial fission for anti-cancer

Mitochondrial shape rapidly changes by dynamic balance of fusion and fission to adjust to constantly changing energy demands of cancer cells. Mitochondrial dynamics balance is exactly regulated by molecular motor consisted of myosin and actin cytoskeleton proteins. Thus, targeting myosin-actin molecular motor is considered as a promising strategy for anti-cancer. In this study, we performed a proof-of-concept study with a natural-derived small-molecule J13 to test the feasibility of anti-cancer therapeutics

Relationship between DEAD-box helicase 5, transcription factor 12 and amyotrophic lateral sclerosis / 解剖学报

Objective To explore the relationship between the expression of DEAO-box helicase 5(DDX5) and transcription factor 12(TCF12) with amyotrophic lateral sclerosis ( ALS ) hippocampal lesions by detecting the expressions and the interaction of DDX5 and TCF12 in the hippocampus of SOD1-G93A mutant ALS transgenic mice. Methods Forty- two pairs of SOD1-G93A mutant ALS transgenic mice and wild-type mice were divided into three groups at the age of 95 days (early onset stage), 108 days (middle onset stage) and 122 days (late onset stage). RT-PCR, Western blotting and double immunofluorescence labeled technique were used to detect the expressions of DDX5 and TCF12 in the hippocampus. Co-immunoprecipitation assasy was used to detect the interaction between DDX5 and TCF12. Results Compared with the wild-type mice of the same age, DDX5 and TCF12 mRNA in the hippocampus of SOD1-G93A mutant ALS transgenic mice were unchanged, but DDX5 and TCF12 protein were up-regulated significantly at day 95, 108 and 122. DDX5 and TCF12 positive cells were found in both DG area and hippocampus proper, and DDX5 and TCF12 were co-localized with neurons. The immunoreactivities of DDX5 and TCF12 in the hippocampus of SOD1-G93A mutant transgenic mice were elevated compared with wild-type mice at the same time point. Co-immunoprecipitation assasys confirmed that there existed interactions between DDX5 and TCF12 protein. Conclusion DDX5 and TCF12 protein are up-regulated in the hippocampal tissues of SOD1-G93A mutant ALS transgenic mice. The abnormal expressions of DDX5 and TCF12 are involved in the hippocampal lesions of ALS.

Three-dimensional chromosome conformation capture and its derived technologies / 生物工程学报

Linear chromatin is compacted into eukaryotic nucleus through a complex and multi-layered architecture. Consequently, chromatin conformation in a local or long-distance manner is strongly correlated with gene expression. Chromosome conformation capture (3C) technology, together with its variants like 4C/5C/Hi-C, has been well developed to study chromatin looping and whole genome structure. In this review, we introduce new technologies including chromosome capture combined with immunoprecipitation, nuclei acid-based hybridization, single cell and genome sequencing, as well as their application.

Eukaryotic expression, Co-IP and MS identify BMPR-1B protein-protein interaction network

BACKGROUND: BMPR-1B is part of the transforming growth factor ß super family and plays a pivotal role in ewe litter size. Functional loss of exon-8 mutations in the BMPR-1B gene (namely the FecB gene) can increase both the ewe ovulation rate and litter size. RESULTS: This study constructed a eukaryotic expression system, prepared a monoclonal antibody, and characterized BMPR-1B/FecB protein-protein interactions (PPIs). Using Co-immunoprecipitation coupled to mass spectrometry (Co-IP/MS), 23 proteins were identified that specifically interact with FecB in ovary extracts of ewes. Bioinformatics analysis of selected PPIs demonstrated that FecB associated with several other BMPs, primarily via signal transduction in the ovary. FecB and its associated interaction proteins enriched the reproduction process via BMP2 and BMP4 pathways. Signal transduction was identified via Smads proteins and TGF-beta signaling pathway by analyzing the biological processes and pathways. Moreover, other target proteins (GDF5, GDF9, RhoD, and HSP 10) that interact with FecB and that are related to ovulation and litter size in ewes were identified. CONCLUSIONS: In summary, this research identified a novel pathway and insight to explore the PPi network of BMPR-1B.

The improvewment of DNA library construction in non-crosslinked chromatin immunoprecipitation coupled with next-generation sequencing / 南方医科大学学报

OBJECTIVE@#To optimize DNA library construction in non-crosslinked chromatin immunoprecipitation coupled with next-generation sequencing (Native ChIP-seq) to obtain high-quality Native ChIP-seq data.@*METHODS@#Human nasopharyngeal carcinoma HONE1 cell lysate was digested with MNase for release of the nucleosomes, and the histone-DNA complexes were immunoprecipitated with specific antibodies. The protein component in the precipitate was digested with proteinase K followed by DNA purification; the DNA library was constructed for sequence analysis.@*RESULTS@#Compared with the conventional DNA library construction, Tn5 transposase method allowed direct enrichment of the target DNA after Tn5 fragmentation, which was simple, time-saving and more efficient. The IGV visualized map showed that the information obtained by the two library construction methods was consistent. The sequencing data obtained by the two methods revealed more signal enrichment with Tn5 transposase library construction than with the conventional approach. H3K4me3 ChIP results showed a good reproducibility after Tn5 transposase library construction with a signal-to-noise ratio above 50%.@*CONCLUSIONS@#Tn5 transposase method improves the efficiency of DNA library construction and the results of subsequent sequence analysis, and is especially suitable for detecting histone modification in the DNA to provide a better technical option for epigenetic studies.

Isolation and identification of Oct4 RNA-binding proteins / 上海交通大学学报（医学版）

Objective: To identify the RNA binding proteins of Oct4, a key factor of embryonic stem cells. Methods: Total RNA was extracted from mouse embryonic stem cells (R1), which was reverse-transcribed into cDNA. Then PCR product of Oct4 mRNA were transcribed into Oct4 mRNA. Finally the candidate RNA-binding proteins were eluted applying the streptomycin affinity chromatography, and submitted for high-performance liquid chromatography combined with the mass spectrometry. The identified RNA binding proteins were further confirmed by RNA immunoprecipitation (RIP). Results: 121 RNA binding proteins of Oct4 3' untranslated region (UTR) and Oct4 5' UTR were identified with liquid chromatography / mass spectrometry. There were 11 proteins with the number of peptide spectrum matches more or equal to 2, and 7 of them were selected for additional confirmation using RIP method. RIP results showed that Oct4 interacted with DSP, SOD1, LMNA, NPM1, PSIP1, NCL and HDGF. Among them, HDGF had the strongest binding ability to Oct4 mRNA. Conclusion: Identification of Oct4 RNA binding proteins will provide a theoretical basis for the regulation mechanism of Oct4, and will be a basis for the further study of its function.

Regulatory effect of grainyhead-like 2 gene on proliferation of epithelial ovarian cancer cells by nuclear factor erythroid-2-related factor 2 transcription / 解剖学报

Objective: To study the effect of nuclear factor erythroid-2-related factor 2(Nrf2) and the downstream gene grainyhead-like 2(GRHL2) on epithelial ovarian cancer cell lines and the interaction of Nrf2 and GRHL2. Methods: We conducted ChlP-PCR assay to test the binding of Nrf2 with six candidate genes including GRHL2. Furthermore, we proved whether Nrf2 could bind with the GRHL2 promoter and transcriptionally activate the GRHL2 gene or not. Moreover, if the overexpression and knockdown of Nrf2 could increase and decrease the GRHL2 protein respectively. Results: We discovered that fallopian tube epithelial cells taken from epithelial ovarian cancer patients and ovarian cancer cell lines highly expressed the Nrf2 and GRHL2 at mRNA level. The overexpression and knockdown of Nrf2 could increase and decrease the cells activity, respectively. However, the knockdown of GRHL2 could inhibit the influence of Nrf2 overexpression. Conclusion: Nrf2 promotes the activity of epithelial ovarian cancer cells via modulating the GRHL2 gene transcriptionally.

Effect of acetylation modification on microenvironment adaptability of mesenchymal stem cells / 解放军医学杂志

Objective To study the changes of acetylation level of smooth muscle marker gene after the differentiation of bone marrow mesenchymal stem cells (BMSCs) in smooth muscle microenvironment, and explore the role and mechanism of histone acetylation modification in the differentiation of stem cells. Methods BMSCs and bladder smooth muscle cells (BSMCs) were cultured in vitro. The third generation BMSCs of the same batch were selected, and BMSCs co-cultured with BSMCs for 3 days were set as the experimental group and the BMSCs without co-culture as the control group. RT-PCR was performed to compare the expression abundance between the two groups of α-smooth muscle actin (α-SMA), calponin and smooth muscle myosin heavy chain (SM-MHC) in BMSCs. Ultrasound of power 80%, 20 times, 0.5 s and 8 cycles were used to break the BMSCs DNA of both experimental and control group. Antibody H3K9 was used to bind to the specific acetylation sites. The acetylation site genes of histone in BMSCs were precipitated by chromatin immunoprecipitation (ChIP). The genes obtained was amplified by adaptor PCR. The expression levels of the three kinds of target genes (α-SMA, calponin, SM-MHC) were detected by Real-time PCR. Results RT-PCR showed that the expression levels of mRNA of smooth muscle marker genes (α-SMA, calponin, SM-MHC) in BMSCs were significantly higher in experimental group than in control group (0.176±0.003 vs. 0.070±0.002; 0.079±0.002 vs. 0.051±0.003 and 0.091±0.004 vs. 0.034±0.001, respectively) with significant differences. Test results of spectrophotometer showed that the amount of DNA obtained by precipitation of H3K9 acetylated antibody was higher than that of IgG antibody, and was higher in experimental group than in control group (P<0.05). Real-time PCR used to analyze the acetylation level of H3K9 before and after the differentiation of BMSCs showed that the mRNA transcription levels of smooth muscle marker genes (α-SMA, calponin, SM-MHC) were significantly higher in experimental group than in the control group (9.26±5.03 vs. 1.01±0.05, 2.33±0.65 vs. 0.99±0.05, 2.63±0.37 vs. 1.00±0.03, respectively) after BMSCs differentiation with statistically significant differences. Conclusion The increase of acetylation level of H3K9 specific site of BSMCs in smooth muscle microenvironment promotes the differentiation of BMSCs into BSMCs.

Aurone derivatives as Vps34 inhibitors that modulate autophagy

We report in this study the identification of a natural product-like antagonist () of Vps34 as a potent autophagy modulator structure-based virtual screening. Aurone derivative strongly inhibited Vps34 activity in cell-free and cell-based assays. Significantly, prevents autophagy in human cells induced either by starvation or by an mTOR inhibitor. modeling and kinetic data revealed that could function as an ATP-competitive inhibitor of Vps34. Moreover, it suppressed autophagy and without inducing heart or liver damage in mice. could be utilized as a new motif for more selective and efficacious antagonists of Vps34 for the potential treatment of autophagy-related human diseases.

Screening of S-phase kinase-assuciated protein 2 in the cervical carcinoma HeLa cell / 中国肿瘤生物治疗杂志

@#[Abstract] Objective： ：The co-immunoprecipitation and mass spectrometric analysis was carried out to obtain the S-phase kinase-associated protein 2 (SKP2)-binding proteins in HeLa cells, and the biological functions of these binding proteins were forecast. Methods: The co-immunoprecipitation system was established by co-immunoprecipitation and Western blotting assay; the specific protein gel of SKP2-binding proteins was obtained by SDS-PAGE and silver staining assay; the potential SKP2-binding proteins was identified by mass spectrometric analysis; and the GO (Gene ontology) analysis and KEGG analysis was carried out by bioinformatics technique. Results: The expression level of SKP2 protein in HeLa cells was high enough for co-immunoprecipitation assay; the co-immunoprecipitation system was established successfully, and SKP2-binding proteins was obtained; a total of 563 proteins were identified by mass spectrometric analysis, and 270 proteins with high credibility were obtained after screening. The GO analysis and KEGG analysis was carried out for the 270 proteins to forecast their functions and pathways. Conclusion: The SKP2-binding proteins were screened successfully, and it was the foundation for the subsequent screening of target-binding proteins and the search for targeting drugs.