Secretory Phenotype in Peripheral Blood Mononuclear Cells of Elderly Patients with Rheumatoid Arthritis.

This study aims to investigate the expression differences of peripheral blood mononuclear cells (PBMCs) in patients with elderly rheumatoid arthritis (ERA). Differentially expressed genes (DEGs) of PBMCs between young patients with RA (RA_Y) and elderly patients with RA (RA_A) were identified by RNA sequencing using the DESeq2 package, followed by bioinformatics analysis. The overlapped targets of the current DEGs and proteomic differentially expressed proteins (another set of unpublished data) were identified and further validated. The bioinformatics analysis revealed significant transcriptomic heterogeneity between RA_A and RA_Y. A total of 348 upregulated and 363 downregulated DEGs were identified. Gene functional enrichment analysis indicated that the DEGs, which represented senescence phenotype for patients with ERA, were enriched in pathways such as Phosphatidylinositol3 kinase/AKT serine-threonine protein kinase (PI3K/Akt) signaling, Mitogen-activated protein kinases (MAPK) signaling, toll-like receptor family, neutrophil degranulation, and immune-related pathways. Gene set enrichment analysis further confirmed the activation of humoral immune response pathways in RA_A. Quantitative polymerase chain reaction validated the expression of five representative DEGs such as SPTA1, SPTB, VNN1, TNXB, and KRT1 in PBMCs of patients with ERA. Patients with ERA have significant senescence phenotype differences versus the young patients. The DEGs identified may facilitate exploring the biomarkers of senescence in RA.

Genetic characteristics of classical astroviruses in Shenzhen, China, 2016-2019.

Human astrovirus (HAstV) is a single-stranded, positive-sense RNA virus and is the leading cause of viral gastroenteritis. However, despite its prevalence, astroviruses still remain one of the least studied enteroviruses. In this study, we sequenced 11 classical astrovirus strains from clinical samples collected in Shenzhen, China from 2016 to 2019, analyzed their genetic characteristics, and deposited them into GenBank. We conducted phylogenetic analysis using IQ-TREE software, with references to astrovirus sequences worldwide. The phylogeographic analysis was performed using the Bayesian Evolutionary Analysis Sampling Trees program, through Bayesian Markov Chain Monte Carlo sampling. We also conducted recombination analysis with the Recombination Detection Program. The newly sequenced strains were categorized as HAstV genotype 1, which is the predominant genotype in Shenzhen. Phylogeographic reconstruction indicated that HAstV-1 may have migrated from the United States to China, followed by frequent transmission between China and Japan. The recombination analysis revealed recombination events within and across genotypes, and identified a recombination-prone region that produced relatively uniform recombination breakpoints and fragment lengths. The genetic analysis of HAstV strains in Shenzhen addresses the current lack of astrovirus data in the region of Shenzhen and provides key insights to the evolution and transmission of astroviruses worldwide. These findings highlight the importance of improving surveillance of astroviruses.

Gancao Nourishing-Yin decoction combined with methotrexate in treatment of aging CIA mice: a study based on DIA proteomic analysis.

BACKGROUND: Elderly rheumatoid arthritis (ERA) population faces multiple treatment dilemma. Here we aim to investigate if Gancao Nourishing-Yin decoction (GCNY) added to methotrexate (MTX) exhibit better effects in an ERA mice model. METHODS: ERA mice model was established by adding D-galactose (Dgal) to collagen-induced arthritis (CIA) mice. The model was then assigned into control group (CIA + Dgal), MTX treatment group (MTX), GCNY treatment group (GCNY), and integrative treatment group (MTX + GCNY). Pathological scoring was performed to evaluate the severity between the groups. Proteomic analysis was applied to investigate the secretory phenotype of the ERA mouse model and the underlying mechanism of GCNY, MTX and their combination. Representative cytokines related to proteomic results were further validated by ELISAs. RESULTS: CIA + Dgal mice showed more aggressive joints damage than the CIA mice. Besides changes in the inflammatory pathway such as Pi3k-Akt signaling pathway in both model, differential expressed proteins (DEPs) indicated metabolism-related pathways were more obvious in CIA + Dgal mice. Low-dose MTX failed to show pathological improvement in CIA + Dgal mice, while GCNY improved joints damage significantly. Besides down-regulated inflammation-related targets, GCNY-regulated DEPs (such as Apoc1 ~ 3, Grk2 and Creb3l3) were broadly enriched in metabolism-related pathways. MTX + GCNY showed the best therapeutic effect, and the DEPs enriched in a variety of inflammatory,metabolism and osteoclast differentiation signaling pathway. Notably, MTX + GCNY treatment up-regulated Dhfr, Cbr1, Shmt1 involved in folic acid biosynthesis and anti-folate resistance pathways indicated a coincidence synergic action. ELISAs confirmed CPR and Akt that elevated in CIA + Dgal mice were significantly ameliorated by treatments, and adding on GCNY elevated folic acid levels and its regulator Dhfr. CONCLUSION: Aging aggravated joints damage in CIA, which probably due to metabolic changes rather than more severe inflammation. GCNY showed significant effects in the ERA mice model especially when integrated with MTX to obtain a synergic action.

Occurrence and Health Risks of Heavy Metals in Drinking Water of Self-Supplied Wells in Northern China.

Self-supplied wells, an important water resource in remote and scattered regions, are commonly deteriorated by environmental pollution and human activity. In this study, 156 self-supplied well-water samples were collected from remote and scattered areas of Inner Mongolia (NMG), Heilongjiang (HLJ), and the suburbs of Beijing (BJ) in Northern China. Twenty-four heavy metals were identified by using the inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES), and the associated human health risks were assessed by using standards of the US Environmental Protection Agency (US EPA). The concentrations of four heavy metals (As, Fe, Mn, and Tl) in HLJ, one heavy metal (Tl) in BJ, and ten heavy metals (Al, As, B, Cr, Fe, Mn, Mo, Se, Tl, and Zn) in NMG exceeded the limits set by China or the World Health Organization (WHO). The total carcinogenic risk (TCR) and total non-carcinogenic risk (THQ) exceeding set limits mainly occurred in NMG, compared to HLJ and BJ. Moreover, As accounted for 97.87% and 60.06% of the TCR in HLJ and BJ, respectively, while Cr accounted for 70.83% of the TCR in NMG. The TCR caused by Cd in all three areas had a negligible hazard (<10-4). As accounted for 51.11%, 32.96%, and 40.88% of the THQ in HLJ, BJ, and NMG, respectively. According to the results of the principal component analysis, heavy metals in well water from HLJ and NMG mainly originated from mixed natural processes and anthropogenic sources, whereas, in BJ, most heavy metals probably originated from natural sources. In the future, long-term monitoring of heavy metals in water from self-supplied wells should be conducted for an extensive range of well-water sites, and well water with high As contamination should be monitored more and fully assessed before being used as a drinking-water source.

TRIM46 upregulates Wnt/ß-catenin signaling by inhibiting Axin1 to mediate hypoxia-induced epithelial-mesenchymal transition in HK2 cells.

Hypoxia can cause Epithelial-mesenchymal transition (EMT) in renal tubular cells, and in turn, renal fibrosis. We tested the expression of TRIM46, a member of tripartite motif-containing (TRIM) family proteins, and mesenchymal markers under hypoxia. Our results showed that hypoxia significantly enhanced expression of TRIM46 in HK2 human renal proximal tubular epithelial cells. Our data further showed that hypoxia led to upregulated expression of mesenchymal markers including α-smooth muscle actin, vimentin, and Snail, and downregulated expression of epithelial marker E-cadherin, coupled with an increased abundance of nuclear ß-catenin. However, such effects were reversed when TRIM46 expression was knocked down. TRIM46 overexpression had similar effects as hypoxia exposure, and such effects were reversed when cells were treated with XAV-939, a selective inhibitor for ß-catenin. Furthermore, we found that TRIM46 promoted ubiquitination and proteasomal degradation of Axin1 protein, a robust negative regulator of Wnt/ß-catenin signaling activity. Finally, increased TRIM46 coupled with decreased Axin1 was observed in a rat renal fibrosis model. These data suggest a novel mechanism contributing to EMT that mediates hypoxia-induced renal fibrosis. Our results suggest that selectively inhibiting this pathway that activates fibrosis in human kidney may lead to development of a novel therapeutic approach for managing this disease.

Dissemination of blaNDM-5 in Escherichia coli through the IncX3 Plasmid from Different Regions in China.

The spread of NDM-5-producing Escherichia coli has become a severe challenge in clinical therapy, which necessitates reliable detection and surveillance methods. However, limited information is available regarding the prevalence and dissemination of the blaNDM-5 gene in E. coli in China. Therefore, we investigated the dissemination of the blaNDM-5 gene in carbapenem-resistant E. coli isolates from different regions. A total of 1,180 carbapenem-resistant enterobacteriaceae strains were obtained from patients admitted to the 20 sentinel hospitals in 8 cities. Strains positive for blaNDM-5 were detected using the Vitek 2 compact system, 16S ribosomal RNA (rRNA) gene sequencing, polymerase chain reaction, the S1 pulsed-field gel electrophoresis assay, and Southern blot hybridization. The horizontal-transfer capability of the blaNDM gene was assessed by filter mating with a standard E. coli J53 azide-resistant strain as the recipient. Genotyping, susceptibility testing, and whole genome sequencing were performed. Seven strains of blaNDM-5-positive E. coli were detected in 1,180 clinical strains from different regions in China. The blaNDM-5-carrying strains showed resistance to multiple tested antibiotics and belonged to two widespread sequence types, sequence type (ST)167 and ST405. Antimicrobial resistance genes, including blaCTX-M, blaOXA, blaCMY, and two novel blaTEM variants (blaTEM-230 and blaTEM-231) were also identified. Southern blotting located the blaNDM-5 gene on 46 kb IncX3 plasmids in all isolates, which showed only two single nucleotide differences between EJN003 and the other strains. This study further confirms the increasing occurrence of blaNDM-5-carrying IncX3 plasmids and the dissemination of carbapenem resistance in E. coli isolates using the plasmid from different parts in China, which warrants stringent surveillance and control measures.

The Expression of TRIM6 Activates the mTORC1 Pathway by Regulating the Ubiquitination of TSC1-TSC2 to Promote Renal Fibrosis.

Renal fibrosis is considered as the final pathway of all types of kidney diseases, which can lead to the progressive loss of kidney functions and eventually renal failure. The mechanisms behind are diversified, in which the mammalian target of rapamycin (mTOR) pathway is one of the most important regulatory pathways that accounts for the disease. Several processes that are regulated by the mTOR pathway, such as autophagy, epithelial-mesenchymal transition (EMT), and endoplasmic reticulum (ER) stress, are tightly associated with renal fibrosis. In this study, we have reported that the expression of tripartite motif-containing (TRIM) protein 6, a member of TRIM family protein, was highly expressed in renal fibrosis patients and positively correlated with the severity of renal fibrosis. In our established in vitro and in vivo renal fibrosis models, its expression was upregulated by the Angiotensin II-induced nuclear translocation of nuclear factor-κB (NF-κB) p50 and p65. In HK2 cells, the expression of TRIM6 promoted the ubiquitination of tuberous sclerosis proteins (TSC) 1 and 2, two negative regulators of the mTORC1 pathway. Moreover, the knockdown of TRIM6 was found efficient for alleviating renal fibrosis and inhibiting the downstream processes of EMT and ER in both HK2 cells and 5/6-nephrectomized rats. Clinically, the level of TRIM6, TSC1/2, and NF-κB p50 was found closely related to renal fibrosis. As a result, we have presented the first study on the role of TRIM6 in the mTORC1 pathway in renal fibrosis models and our findings suggested that TRIM6 may be a potential target for the treatment of renal fibrosis.

LncRNA NEAT1 Promotes High Glucose-Induced Mesangial Cell Hypertrophy by Targeting miR-222-3p/CDKN1B Axis.

Glomerular hypertrophy is an early morphological alteration in diabetic nephropathy. Cyclin-Dependent Kinases have been shown to be required for high glucose (HG)-induced hypertrophy; however, the upstream regulators of CDKN1B in glomerular hypertrophy remain unclear. Herein we describe a novel pathway in which Long noncoding RNA (lncRNA) NEAT1 regulates the progression of mesangial cell hypertrophy via a competing endogenous RNA (ceRNA) mechanism. Real-time PCR was performed to detect the relative NEAT1 and miR-222-3p expressions and further confirmed the relationship between NEAT1 and miR-222-3p. Cell cycle was evaluated by flow cytometry. The related mechanisms were explored by Western blot, RNA immunoprecipitation and chromatin immunoprecipitation assay. We show that NEAT1 forms double stranded RNA (dsRNA) with miR-222-3p, thus limiting miR-222-3p's binding with CDKN1B. This release of CDKN1B mRNA leads to elevated CDKN1B protein expression, resulting in hypertrophy. In addition, we demonstrated that STAT3 which is activated by HG induces the transcription of NEAT1 by binding to its promoter. Our findings underscore an unexpected role of lncRNAs on gene regulation and introduce a new mode of proliferation regulation in mesangial cells.

Insulin-Like Growth Factor 1 Regulates Acute Inflammatory Lung Injury Mediated by Influenza Virus Infection.

The acute inflammatory lung injury is an important cause of death due to influenza A virus (IAV) infection. Insulin-like growth factor 1 (IGF1) played an important role in the regulation of inflammation in the immune system. To investigate the role of IGF1 in IAV-mediated acute inflammatory lung injury, the expression of IGF1 and inflammatory cytokines was tested after IAV A/Puerto Rico/8/1934 (H1N1; abbreviated as PR8) infection in A549 cells. Then, a BALB/c mouse model of PR8 infection was established. On days 3, 5, 7, and 9 post-infection, the mice lung tissue was collected to detect the expression changes in IGF1 mRNA and protein. The mice were divided into four groups: (1) PBS (abbreviation of phosphate buffered saline); (2) PR8 + PBS; (3) PR8 + IGF1; and (4) PR8 + PPP (abbreviation of picropodophyllin, the IGF1 receptor inhibitor). The body weight and survival rate of the mice were monitored daily, and the clinical symptoms of the mice were recorded. On day 5 post-infection, the mice were sacrificed to obtain the serum and lung tissues. The expression of inflammatory cytokines in the serum was detected by enzyme linked immunosorbent assay; lung injury was observed by hematoxylin-eosin staining; the viral proliferation in the lung was detected by real-time quantitative PCR; and the protein expression of the main molecules in the phosphatidylinositol-3-kinases/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase (MAPK) signaling pathways was detected by Western blot. It was found that IGF1 expression is upregulated in A549 cells and BALB/c mice infected with PR8, whereas IGF1 regulated the expression of inflammatory cytokines induced by PR8 infection. Overexpression of IGF1 aggravated the IAV-mediated inflammatory response, whereas the inhibition of IGF1 receptor reduced such inflammatory response. The phosphorylation of IGF1 receptor triggered the PI3K/AKT and MAPK signaling pathways to induce an inflammatory response after IAV infection. Therefore, IGF1 plays an important immune function in IAV-mediated acute inflammatory lung injury. IGF1 may provide a therapeutic target for humans in response to an influenza outbreak, and inhibition of IGF1 or IGF1 receptor may represent a novel approach to influenza treatment.

Thermal debinding behavior of a low-toxic DMAA polymer for gelcast ceramic parts based on TG-FTIR and kinetic modeling.

In this work, the pyrolysis characteristics of a low-toxic N,N-dimethylacrylamide (DMAA) gel polymer was investigated through nonisothermal thermogravimetry (TG) and TG-FTIR analyses. Moreover, the thermal debinding kinetics of gelcast SiAlON ceramic parts was studied through three different kinetic models: the Coats-Redfern (C-R) method, distributed activation energy model (DAEM) and three-Gaussian-DAEM-reaction model (3-DAEM). The rationality and adaptability of the three models to the thermal debinding kinetics study were analyzed by comparison with experimental data. The results showed that three mass loss zones were observed in the temperature ranges of 100-320 °C, 320-520 °C and 520-600 °C, respectively, and the main pyrolysis gas products were CO2, H2O and CH4. The conversion rate (α) curves calculated by 3-DAEM were more consistent with the experimental values than those calculated with the C-R and DAEM methods. The fitting quality parameter (Fit%) was less than 2.63%, and the reaction rate (dα/dT) curves calculated by 3-DAEM were bimodal distribution curves, which were in good agreement with the experimental results. The kinetic parameters (E 0,i , k 0,i and σ i ) of the global thermal debinding process calculated by 3-DAEM were 116.00-145.79 kJ mol-1, 1.10 × 109 s-1 and 1.67-43.25 kJ mol-1, respectively. It is anticipated that the study achievements can be used to help predict the thermal debinding behavior and design a reasonable debinding technology for the gelcasting of ceramic parts.

Mechanism research of Bu-Shen-Huo-Xue formula against renal fibrosis in rats with 5/6 nephrectomy via E-cadherin, α-SMA, and TGF-ß1
.

OBJECTIVE: Renal fibrosis generally results in renal failure during the end stage of chronic renal diseases. There are many cell factors including E-cadherin, α-SMA, and TGF-ß1 influencing deposition of extracellular matrix and leading to renal fibrosis. As the most important and widely-used therapy for various diseases in China for thousands of years, traditional Chinese medicine (TCM) provides a novel treatment for renal fibrosis. For clinical application, we explore the effect of Bu-Shen-Huo-Xue formula (BSHX), a traditional Chinese herbal formula, on E-cadherin and α-SMA in rats with 5/6 nephrectomy. MATERIALS AND METHODS: Sprague-Dawley rats were subjected to 5/6 nephrectomy to induce chronic renal failure (CRF); they were divided into three groups including a CRF control group, a BSHX group, and a Cozaar group, and compared with a normal control group. After 8 weeks of therapy with the respective drug, E-cadherin, α-SMA, and TGF were detected by immunohistochemistry assays in renal tissues. RESULTS: As the immunohistochemistry assays indicated, BSHX could significantly enhance the expression of E-cadherin and depress the levels of α-SMA and TGF-ß1 expression in rats' renal tissues with 5/6 nephrectomy. CONCLUSION: BSHX can effectively relieve the renal fibrosis in rats with 5/6 nephrectomy via the change of cell factor levels including enhancement of the expression of E-cadherin and depression of the levels of α-SMA and TGF-ß1 expression.
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Berberine protects HK-2 cells from hypoxia/reoxygenation induced apoptosis via inhibiting SPHK1 expression.

Renal ischemia reperfusion injury (RIRI) refers to the irreversible damage for renal function when blood perfusion is recovered after ischemia for an extended period, which is common in clinical surgeries and has been regarded as a major risk for acute renal failures (ARF) that is accompanied with unimaginably high morbidity and mortality. Hypoxia during ischemia followed by reoxygenation via reperfusion serves as a major event contributing to cell apoptosis, which has been widely accepted as the vital pathogenesis in RIRI. Preventing apoptosis in renal tubular epithelial cell has been considered as effective method for blocking RIRI. In this paper, we established a hypoxia/reoxygenation (H/R) injury model in human proximal tubular epithelial HK-2 cells. Here, we found increased SPHK1 levels in H/R injured HK-2 cells, which could be significantly down regulated after berberine treatment. Berberine has been reported to exert a protective effect on H/R-induced apoptosis of HK-2 cells. So, in our present study, we planned to investigate whether SPHK1 participated in the anti-apoptosis process of berberine in H/R injured HK-2 cells. Our study confirmed the protective effect of berberine against H/R-induced apoptosis in HK-2 cells through promoting cells viability, inhibiting cells apoptosis, and down-regulating p-P38, caspase-3, caspase-9 as well as SPHK1, while up regulating the ratio of Bcl-2/Bax. However, SPHK1 overexpression in HK-2 cells induced severe apoptosis, which can be significantly ameliorated with additional berberine treatment. We concluded that berberine could remarkably prevent H/R-induced apoptosis in HK-2 cells through down-regulating SPHK1 expression levels, and the mechanisms included the suppression of p38 MAPK activation and mitochondrial stress pathways.

A Multicenter Study Evaluating Ceftriaxone and Benzathine Penicillin G as Treatment Agents for Early Syphilis in Jiangsu, China.

BACKGROUND: The aim of this study was to assess the efficacy of ceftriaxone and benzathine penicillin G (BPG) in nonpregnant, immunocompetent adults with early syphilis because there is a lack of clinical evidence supporting ceftriaxone as an alternative treatment for early syphilis without an human immunodeficiency virus coinfection. METHODS: A randomized, open-label controlled study evaluating the efficacy of ceftriaxone and BPG was conducted in 4 hospitals in Jiangsu Province. Treatment comprised either ceftriaxone (1.0 g, given intravenously, once daily for 10 days) or BPG (2.4 million units, given intramuscularly, once weekly for 2 weeks). A serological response was defined as a ≥4-fold decline in the rapid plasma reagin (RPR) titer. RESULTS: In all, 301 patients with early syphilis were enrolled in this study; 230 subjects completed the follow-ups. The serological response at 6 months of follow up was observed in 90.2% in ceftriaxone group and 78.0% in BPG group (P = .01). There was no significant difference between treatment groups in patients with primary or early latent syphilis, but among patients with secondary syphilis the difference was highly significant (95.8% vs 76.2%; P < .01). Moreover, patients exhibiting a Jarisch-Herxheimer reaction after treatment might have a shorter period before a serological response (P = .03). CONCLUSIONS: In this study, ceftriaxone regimen was noninferior to the BPG regimen in nonpregnant, immunocompetent patients with early syphilis. CLINICAL TRIALS REGISTRATION: ChiCTR-TQR-13003624.

Diversity of New Delhi metallo-beta-lactamase-producing bacteria in China.

OBJECTIVES: The prevalence and dissemination of diverse NDM-producing bacteria in China was investigated. METHODS: We collected 1,162 isolates from 8 cities during December 2013∼May 2015 in China. The NDM-positive strains as well as the NDM genotypes in these sample were detected via Vitek 2 compact system (bioMérieux, France), 16S rRNA gene sequencing, PCR and an S1- pulsed-field gel electrophoresis assay and Southern blot hybridization. The horizontal-transfer capability of the blaNDM gene was assessed by filter mating by using a standard E.coli J53 azide-resistant strain as the recipient. RESULTS: Three genotypes (NDM-1, NDM-3 and NDM-5) of NDM-producing bacteria were identified, among which the NDM-1-positive isolates were the most frequent one. For the first time, we found NDM-5-produing S.typhimurium and NDM-3-produing E.coli in China. We also found that the NDM-positive (especially NDM-3 and NDM-5) strains were completely resistant to nearly all of the antimicrobial drugs utilized and blaNDM was mostly located on diverse plasmids with sizes ranging from 30 to 670kb. CONCLUSION: Various species of bacteria especially the enteric pathogens with diverse NDM genotypes had spread in China. Hence, an ongoing surveillance of their dissemination is essential to prevent and control the spread of these organisms.

Relationship between Antibiotic Resistance, Biofilm Formation, and Biofilm-Specific Resistance in Acinetobacter baumannii.

In this study, we aimed to examine the relationships between antibiotic resistance, biofilm formation, and biofilm-specific resistance in clinical isolates of Acinetobacter baumannii. The tested 272 isolates were collected from several hospitals in China during 2010-2013. Biofilm-forming capacities were evaluated using the crystal violet staining method. Antibiotic resistance/susceptibility profiles to 21 antibiotics were assessed using VITEK 2 system, broth microdilution method or the Kirby-Bauer disc diffusion method. The minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) to cefotaxime, imipenem, and ciprofloxacin were evaluated using micro dilution assays. Genetic relatedness of the isolates was also analyzed by pulsed-field gel electrophoresis (PFGE) and plasmid profile. Among all the 272 isolates, 31 were multidrug-resistant (MDR), and 166 were extensively drug-resistant (XDR). PFGE typing revealed 167 pattern types and 103 clusters with a similarity of 80%. MDR and XDR isolates built up the main prevalent genotypes. Most of the non-MDR isolates were distributed in a scattered pattern. Additionally, 249 isolates exhibited biofilm formation, among which 63 were stronger biofilm formers than type strain ATCC19606. Population that exhibited more robust biofilm formation likely contained larger proportion of non-MDR isolates. Isolates with higher level of resistance tended to form weaker biofilms. The MBECs for cefotaxime, imipenem, and ciprofloxacin showed a positive correlation with corresponding MICs, while the enhancement in resistance occurred independent of the quantity of biofilm biomass produced. Results from this study imply that biofilm acts as a mechanism for bacteria to get a better survival, especially in isolates with resistance level not high enough. Moreover, even though biofilms formed by isolates with high level of resistance are always weak, they could still provide similar level of protection for the isolates. Further explorations genetically would improve our understanding of these processes and provide novel insights in the therapeutics and prevention against A. baumannii biofilm-related infections.

Peripheral blood mononuclear cell traffic plays a crucial role in mother-to-infant transmission of hepatitis B virus.

The role of peripheral blood mononuclear cells (PBMCs) in HBV intrauterine infection is not fully defined. Particularly the origin of PBMCs in HBV-infected neonates remains to be addressed. We carried out a population-based nested case-control study by enrolling 312 HBsAg-positive mothers and their babies. PBMC HBV DNA as well as serum HBsAg and HBV DNA was tested in cohort entry samples. Totally, 45.5% (142/312) of the newborns were found to be infected with HBV in perinatal transmission. 119 mother-infant pairs were identified to be different in the genetic profile of maternal and fetal PBMCs by AS-PCR and hemi-nested PCR. Among them, 57.1% (68/119) of the maternal PBMCs in index cases were positive for HBV DNA while 83.8% (57/68) of the HBV DNA positive maternal PBMCs passed the placental barrier and entered the fetus. Furthermore, maternal PBMC HBV infection was significantly associated with newborn infants HBV infection. PBMC traffic from mother to fetus resulted in a 9.5-fold increased risk of HBV infection in PBMC HBV DNA positive newborn infants. These data indicate that maternal PBMCs infected with HBV contribute to HBV intrauterine infection of newborn infants via PBMC traffic from mother to fetus.

Pokemon (FBI-1) interacts with Smad4 to repress TGF-ß-induced transcriptional responses.

Pokemon, an important proto-oncoprotein, is a transcriptional repressor that belongs to the POK (POZ and Krüppel) family. Smad4, a key component of TGF-ß pathway, plays an essential role in TGF-ß-induced transcriptional responses. In this study, we show that Pokemon can interact directly with Smad4 both in vitro and in vivo. Overexpression of Pokemon decreases TGF-ß-induced transcriptional activities, whereas knockdown of Pokemon increases these activities. Interestingly, Pokemon does not affect activation of Smad2/3, formation of Smads complex, or DNA binding activity of Smad4. TGF-ß1 treatment increases the interaction between Pokemon and Smad4, and also enhances the recruitment of Pokemon to Smad4-DNA complex. In addition, we also find that Pokemon recruits HDAC1 to Smad4 complex but decreases the interaction between Smad4 and p300/CBP. Taken together, all these data suggest that Pokemon is a new partner of Smad4 and plays a negative role in TGF-ß pathway.

[Construction and expression of a eukaryotic expression vector containing human CR2-Fc fusion protein].

OBJECTIVE: To construct a eukaryotic expression vector containing human complement receptor 2 (CR2)-Fc and express the CR2-Fc fusion protein in Chinese hamster ovary (CHO) cells. METHODS: The extracellular domain of human CR2 and IgG1 Fc were respectively amplified, ligated and inserted into the eukaryotic expression vector PCI-neo. After verified by restriction enzyme digestion and sequencing, the recombinant plasmid was transfected into CHO K1 cells. The ones with stable expression of the fusion protein were obtained by means of G418 selection. The expression of the CR2-Fc fusion protein was detected and confirmed by SDS-PAGE and Western blotting. RESULTS: Restriction enzyme digestion and sequencing demonstrated that the recombinant plasmid was valid. SDS-PAGE showed that relative molecular mass (Mr;) of the purified product was consistent with the expected value. Western blotting further proved the single band at the same position. CONCLUSION: We constructed the eukaryotic expression vector of CR2-Fc/PCI-neo successfully. The obtained fusion protein was active and can be used for the further study of the role in HIV control.

Higher isolation of NDM-1 producing Acinetobacter baumannii from the sewage of the hospitals in Beijing.

Multidrug resistant microbes present in the environment are a potential public health risk. In this study, we investigate the presence of New Delhi metallo-ß-lactamase 1 (NDM-1) producing bacteria in the 99 water samples in Beijing City, including river water, treated drinking water, raw water samples from the pools and sewage from 4 comprehensive hospitals. For the bla NDM-1 positive isolate, antimicrobial susceptibility testing was further analyzed, and Pulsed Field Gel Electrophoresis (PFGE) was performed to determine the genetic relationship among the NDM-1 producing isolates from sewage and human, as well as the clinical strains without NDM-1. The results indicate that there was a higher isolation of NDM-1 producing Acinetobacter baumannii from the sewage of the hospitals, while no NDM-1 producing isolates were recovered from samples obtained from the river, drinking, or fishpond water. Surprisingly, these isolates were markedly different from the clinical isolates in drug resistance and pulsed field gel electrophoresis profiles, suggesting different evolutionary relationships. Our results showed that the hospital sewage may be one of the diffusion reservoirs of NDM-1 producing bacteria.