Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs

Reactivating silenced γ-globin expression through the disruption of repressive regulatory domains offers a therapeutic strategy for treating β-hemoglobinopathies. Here, we used transformer base editor (tBE), a recently developed cytosine base editor with no detectable off-target mutations, to disrupt transcription-factor-binding motifs in hematopoietic stem cells. By performing functional screening of six motifs with tBE, we found that directly disrupting the BCL11A-binding motif in HBG1/2 promoters triggered the highest γ-globin expression. Via a side-by-side comparison with other clinical and preclinical strategies using Cas9 nuclease or conventional BEs (ABE8e and hA3A-BE3), we found that tBE-mediated disruption of the BCL11A-binding motif at the HBG1/2 promoters triggered the highest fetal hemoglobin in healthy and β-thalassemia patient hematopoietic stem/progenitor cells while exhibiting no detectable DNA or RNA off-target mutations. Durable therapeutic editing by tBE persisted in repopulating hematopoietic stem cells, demonstrating that tBE-mediated editing in HBG1/2 promoters is a safe and effective strategy for treating β-hemoglobinopathies.

Dual Functions of MDP Monomer with De- and Remineralizing Ability

Methacryloyloxydecyl dihydrogen phosphate (MDP) has been speculated to induce mineralization, but there has been no convincing evidence of its ability to induce intrafibrillar mineralization. Polymers play a critical role in biomimetic mineralization as stabilizers/inducers of amorphous precursors. Hence, MDP-induced biomimetic mineralization without polymer additives has not been fully verified or elucidated. By combining 3-dimensional stochastic optical reconstruction microscopy, surface zeta potentials, contact angle measurements, inductively coupled plasma-optical emission spectroscopy, transmission electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy with circular dichroism, we show that amphiphilic MDP can not only demineralize dentin by releasing protons as an acidic functional monomer but also infiltrate collagen fibrils (including dentin collagen), unwind the triple helical structure by breaking hydrogen bonds, and finally immobilize within collagen. MDP-bound collagen functions as a huge collagenous phosphoprotein (HCPP), in contrast to chemical phosphorylation modifications. HCPP can induce biomimetic mineralization itself without polymer additives by alternatively attracting calcium and phosphate through electrostatic attraction. Therefore, we herein propose the dual functions of amphiphilic MDP monomer with de- and remineralizing ability. MDP in the free state can demineralize dentin substrates by releasing protons, whereas MDP in the collagen-bound state as HCPP can induce intrafibrillar mineralization. The dual functions of MDP monomer with de- and remineralization properties might create a new epoch in adhesive dentistry and preventive dentistry.

A highly sensitive strain sensor with a sandwich structure composed of two silver nanoparticles layers and one silver nanowires layer for human motion detection

The fabrication of strain sensors with high sensitivity, large sensing range and excellent stability is highly desirable because of their promising applications in human motion detection, human-machine interface and electric skin, etc. Herein, by introducing a highly conductive silver nanowire (AgNW) layer between two serried silver nanoparticle (AgNP) layers, forming a sandwich structure, a strain sensor with high sensitivity (a large gauge factor of 2.8 × 10⁵), large sensing range (up to 80% strain) and excellent stability (over 1000 cycles) can be achieved. A combination of experimental and mechanism studies shows that the high performance of the obtained strain sensor is ascribed to the synergy of the highly conductive AgNW layer, astatic AgNP layers and the presence of large cracks in stretching. As a proof-of-concept application, the obtained strain sensor can be used for highly effective human motion detection ranging from large scale motions, i.e. kneel bending and wrist flexion, to subtle scale motions, i.e. pulse and swallowing.

POS0664 A MULTICENTER RANDOMIZED STUDY IN RHEUMATOID ARTHRITIS TO COMPARE IGURATIMOD, METHOTREXATE, OR COMBINATION: 52 WEEK EFFICACY AND SAFETY RESULTS OF THE SMILE TRIAL

Background:

Iguratimod (IGU) has demonstrated efficacy and safety for active rheumatoid arthritis (RA) patients in double-blind clinical trials in China and Japan as a new disease-modifying anti-rheumatic drug (DMARD). There are no studies evaluating the radiographic progression of structural joint damage of IGU for the treatment of RA using the mTSS as the primary endpoint.

Objectives:

Our study was to evaluate the efficacy and safety of IGU monotherapy and IGU combined methotrexate (MTX) compared with MTX monotherapy, including the inhibitory effects of joint destruction.

Methods:

This randomized, double-blind, parallel-controlled, multicenter study in patients with active RA who have not previously used MTX and biological DMARDs (bDMARDs) (ClinicalTrials.gov Identifier NCT01548001) was carried out in China. Patients were randomized 1:1:1 to receive IGU 25 mg twice a day (bid), MTX 10mg once a week(qw) for the first 4 weeks and 15 mg once a week(qw) for week 5 to 52, or IGU combined MTX (IGU+MTX) for 52 weeks. The primary endpoints were to assess and compare American College of Rheumatology 20% (ACR20) response and the change of modified total Sharp scoring (mTSS) score over 52 weeks (Intention-to-treat, ITT analysis). The non-inferiority test was used to analyze the difference of ACR20 response at 52 weeks between the IGU monotherapy and the MTX monotherapy arms, and the non-inferiority limit value was 10%. The difference test was used for the comparison between the IGU+MTX and MTX monotherapy arms. Two-way ANOVA was used to analyze the difference of the changes of mTSS score of each arm compared with baseline value (0 week).

Results:

A total of 895 patients were randomized to IGU 25mg bid (n =297), MTX 10-15mg qw(n=293), and IGU+MTX (n=305). Baseline characteristics were comparable between the arms (Table 1).

Table 1.

Demographic and Other Baseline Characteristics (SAS)

IGUMTXIGU+MTXNumber of Subjects297293305Age, mean (SD) years46.87(10.67)47.63(10.70)48.37(10.69)Female/male, %77.44/22.5679.18/20.8278.03/21.97Duration of RA, mean(SD) years11.67±7.1611.60±7.9811.67±7.27CRP, mean(SD) mg/L222.32±35.4720.67±26.6119.74±31.38Tender joint count, mean (SD)14.59±9.1614.83±9.3014.93±9.88Swollen joint count, mean (SD)9.81±6.639.73±7.209.51±6.22DAS28-CRP, mean (SD)5.084±0.9945.102±0.9795.103±0.956HAQ score, mean (SD)15.82±11.2515.24±10.9316.06±10.92

SAS: Safety Analysis Set; CRP: C-reactive protein;

DAS28: disease activity score; HAQ: Health Assessment Questionnaire

The study met its primary endpoints. More concretely, IGU monotherapy and IGU+MTX were found to be superior to MTX at week 52 with a higher ACR20 response of 77.44%(230/297, P=0.0019) and 77.05%(235/305, P=0.0028) versus 65.87%(193/293) (fig 1). As shown in fig 1, the structural remission (ΔmTSS≤0.5) was statistically significant for IGU monotherapy (57.4%, P=0.0308) but not for IGU+MTX arm (55%) versus MTX monotherapy (47.8%).

Overall incidence of the adverse events (AEs) leading to study discontinuation were reported in 13.8% (41/297) in IGU monotherapy arm, 11.26% (33/293) in MTX monotherapy arm and 11.51% (35/305) patients in IGU+MTX arm. The incidence of adverse drug reactions (ADR) leading to study discontinuation were 11.45% (34/297), 8.53% (25/293) and 9.21% (28/305), respectively. There was no one death and no significant difference in all the safety indicators among the three arms.

Conclusion:

Iguratimod alone or in combination with MTX demonstrated superior efficacy with acceptable safety compared to MTX for patients with active RA who have not previously used MTX bDMARDs.

Disclosure of Interests:

None declared

Pyrrolidinedithiocarbamic Acid Ammonium Salt Inhibits Apoptosis and Phenotypic Transformation of Co-Culture of Myeloma Cells and Renal Tubular Epithelial Cells by Reducing the Secretion of Light Chain Protein

Background:

We investigate the effects of NFϰB inhibitor pyrrolidinedithiocarbamic acid ammonium salt (PDTC) on the viability, apoptosis and cell phenotype of HK-2 cells in the co-culture system of myeloma cells in renal tubular epithelial cells.

Methods:

This study was performed in Qiqihar Medical University, Qiqihar, China from Jun 2018 to Jan 2019. RPMI-8226 cells and HK-2 cells were inoculated in the co-culture chamber and cultured to establish the co-culture system. An immunoturbidimetric assay was performed to detect ϰ light chain and λ light chain in RPMI-8226 cells. The effect of PDTC on the secretion of ϰ light chain and λ light chain of RPMI-8226 cells was detected by immunoturbidimetry and the ratio was calculated.

Results:

PDTC significantly increased the viability of HK-2 cells. PDTC reduced the apoptosis of renal tubular epithelial cells. After PDTC treatment, the expression of cell surface marker E-cadherin decreased, and the expression of α-SMA increased, which induced the renal interstitial fibrosis. The secretion of ϰ light chain and λ light chain of RPMI-8226 cells was significantly decreased after the addition of PDTC, but the ratio was not changed.

Conclusion:

PDTC can inhibit the cell activity, promote apoptosis, and reduce the secretion of secretion of ϰ light chain and λ light chain through inhibiting the NF-ϰB pathway activation of myeloma cell RPMI-8226.

Effects of dexmedetomidine on sepsis-induced liver injury in rats

OBJECTIVE

To explore the effect of dexmedetomidine (DEX) on sepsis-induced liver injury in rats and the mechanism of action, providing certain references for the prevention and treatment of sepsis-induced liver injury in clinical practice.

MATERIALS AND METHODS

A total of 60 male Sprague Dawley (SD) rats were randomly divided into 3 groups, namely sham operation group (Sham group, n=20), sepsis-induced liver injury group [lipopolysaccharides (LPS) group, n=20], and sepsis-induced liver injury + DEX group (LPS + DEX group, n=20) using a random number table. Rat models of sepsis-induced liver injury were established by intraperitoneal injection of LPS (10 mg/kg), and at the same time, DEX was intragastrically injected at a dose of 50 μg/kg. After 24 h, the survival analysis curves of each group of rats were plotted. Meanwhile, the levels of liver function indexes and oxidative stress markers were measured at 12 h in each group of rats. Hematoxylin-eosin (H&E) staining assay was carried out to detect the morphological changes of rat liver cells in each group. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) staining assay was performed to detect the apoptosis level in rat liver tissues in each group. In addition, the expression level of Caspase 3 in three groups of rats was measured through immunohistochemical staining assay. Lastly, the effect of DEX on the protein expression of extracellular signal-regulated kinases 1/2 (ERK1/2) in liver tissues was detected via Western blotting.

RESULTS

DEX significantly improved liver dysfunction induced by LPS and raised the 24 h-survival rates of rats (p<0.05). Besides, H&E staining results showed that DEX clearly relieved the pathological damage of rat liver cells caused by LPS. In comparison with LPS group, LPS + DEX group displayed more neatly arranged liver cells, less degradation and necrosis, and evidently attenuated cellular edema. Immunohistochemistry results revealed that DEX significantly reversed the increase in Caspase 3 expression resulting from LPS. The results of the TUNEL staining assay showed that DEX clearly inhibited the apoptosis of rat liver cells induced by LPS. The results of Western blotting revealed that DEX notably reversed the decrease of phosphorylated ERK1/2 (p-ERK1/2) in rat liver tissues compared with LPS group.

CONCLUSIONS

DEX is able to markedly relieve LPS-induced liver injury in rats and the underlying mechanism may be related to the activation of the ERK1/2 signaling pathway.

Wearable electronics for heating and sensing based on a multifunctional PET/silver nanowire/PDMS yarn

Stretchable and flexible electronics built from multifunctional fibres are essential for devices in human-machine interactions, human motion monitoring and personal healthcare. However, the combination of stable heating and precision sensing in a single conducting yarn has yet to be achieved. Herein, a yarn comprising poly(ethylene terephthalate) (PET), silver nanowires (AgNWs), and polydimethylsiloxane (PDMS) was designed and prepared. The PET/AgNW/PDMS yarn exhibited high electrical conductivity at ≈3 Ω cm-1 and a large tolerance to tensile strain up to 100% its own length. Only a negligible loss of electromechanical performance was observed after 1700 strain cycles. And an excellent response to applied strain was also achieved across a huge stretching range. The PET/AgNW/PDMS yarn displayed excellent heating performance and outstanding breathability when used in a heating fabric, and excellent sensitivity for monitoring both gross and fine movements in humans when used as a sensor.

A comparison of open, laparoscopic and robotic total mesorectal excision: trial sequential analysis and network meta-analysis

AIM

Total mesorectal excision (TME) for rectal cancer can be achieved by employing open (OpTME), laparoscopic (LaTME) and robotic (RoTME) approaches but which of these has the best outcome? The aim of present study is to identify the most effective technique for rectal cancer by comparing all outcomes.

METHODS

Randomized controlled trials (RCTs) which compared at least two TME strategies were identified by literature search of electronic databases of articles published to June 2018. Network meta-analysis with trial sequential analysis was performed using a frequentist approach with random-effects meta-analysis. Data collection and analysis We conducted a systematic search of PubMed, EmBase, the Cochrane Library, CNKI, and Web of Science. Titles and abstracts of the retrieved publications were independently and blindly assessed by two authors.

RESULTS

Twenty-two RCTs with 4882 rectal cancer patients were included in this analysis. The trial sequential analysis demonstrated that the cumulative Z-curve crossed either the traditional boundary or the trial sequential monitoring boundaries, suggesting that OpTME resulted in a more complete TME specimen than LaTME (relative risk 1.05, 95% confidence interval 1.01-1.08). Network meta-analysis showed there was no significant difference in the other comparisons. Based on the P score of completeness of the TME specimen and circumferential resection margin positivity, the best technique was OpTME, followed by RoTME and then LaTME. However, this order was reversed when complications and mortality were considered. RoTME led to better lymph node harvest.

CONCLUSIONS

Although OpTME may give better pathological specimens, minimally invasive techniques may have advantages when considering lymph node harvest, complications and mortality. More RCTs are needed to determine which technique actually gives the best chance of survival.

Water-Based Purification of Ultrathin Silver Nanowires toward Transparent Conductive Films with a Transmittance Higher than 99

Ultrathin silver nanowires (UTAgNWs) are indispensable to achieve transparent conductive films (TCFs) with overall optoelectronic performance exceeding that of the state-of-the-art indium tin oxide films. Impurities in raw UTAgNW products severely impair the optical properties of TCFs. Unfortunately, highly effective and environment-friendly approaches for purification of UTAgNWs are still lacking. Herein, we report the purification of UTAgNWs using deionized water along with a small amount of surfactants as the purifying agent. TCFs coated with the purified UTAgNWs exhibit a light transmittance of 97.9% and a haze of 1.22% at a sheet resistance of 36.3 Ω sq^-1 or a light transmittance of 99.8% and a haze of 0.47% at a sheet resistance of 187.3 Ω sq^-1. Both the transmittance and the haze are among the best reported values for AgNW TCFs in the literature. The purification process does not involve any toxic or hazardous chemicals and is both scalable and cost-effective.

Circulating NK cell subsets and NKT‑like cells in renal transplant recipients with acute T‑cell‑mediated renal allograft rejection

Emerging evidence indicates that natural killer (NK) cells and NKT-like cells may affect allograft outcomes following solid organ transplantation. However, the roles of these cells in allograft acceptance and dysfunction are controversial. To assess the changes in NK cell and CD3⁺CD56⁺ NKT-like cell frequency and phenotype in renal allograft recipients and to explore their associations with acute T-cell-mediated renal allograft rejection (ACR), longitudinal changes in NK and NKT-like cell frequency and phenotype were characterized using flow cytometry and immunohistochemistry in the peripheral blood and kidney allograft tissues in 142 recipients undergoing kidney transplantation. The serum concentrations of NK cell-associated cytokines were also detected by cytokine multiplex immunoassay. In contrast to the healthy controls, recipients with stable graft function exhibited increased proportions of CD56^brightCD16^dim subsets and decreased proportions of NKT-like cells in their peripheral blood mononuclear cells (PBMCs). Patients with ACR demonstrated increased proportions of NK cells, which were associated with increased CD3⁻CD56^bright subsets and decreased CD3⁻CD56^dim subsets, an increase in the CD56^bright/CD56^dim ratio in PBMCs and increased CD56⁺ NK cell infiltration in the kidney allograft, compared with the stable controls. In addition, there was a decreased proportion of NKT-like cells in patients with ACR, and an increased ratio of CD56^bright/NKT-like cells compared with the stable controls. These differences appeared to be consistent with the increase in the serum concentrations of C-C motif chemokine 19 and the decrease in the serum concentrations of interleukin-15. These data indicate that CD56^bright NK cells may promote the development of ACR, and that NKT-like cells may have immunoregulatory function. The results also imply that the CD56^bright/CD56^dim ratio may affect the ACR signatures.

Ectopic expression of E3 ubiquitin-protein ligase 2 in glioma and enhances resistance to apoptosis through activating nuclear factor κ-light-chain-enhancer of B cells

Nuclear factor κ-light-chain-enhancer of B cells (NF-κB) is one of the most important tumorigenic factors. Although it has been established that NF-κB is overly activated in human glioma cells, the molecular mechanisms that lead to the signal transduction to NF-κB and thereby the induction of resistance to apoptosis remain poorly understood. The present study demonstrated that mRNA and protein levels of E3 ubiquitin-protein ligase 2 (MIB2) were markedly upregulated in glioma cell lines and clinical samples. Immunohistochemical analysis also revealed high levels of MIB2 expression in glioma specimens. Ectopic overexpression of MIB2 was established in glioma cell lines to investigate its fundamental roles in the response of human glioma to apoptotic inducers. The results indicated that ultraviolet irradiation-induced cell apoptosis was inhibited with MIB2 overexpression in glioma cells. Notably, knockdown of MIB2 using RNA interference was able to increase the sensitivity of glioma cells to the pro-apoptotic agents. The present study identified that MIB2 induces NF-κB activation and facilitates the resistance of glioma cell to apoptosis. It was proposed that MIB2 may not only be an important hallmark to glioma disease progression, but that it may also offer novel clinical strategies to overcome resistance to cancer therapies.

Exosome-Modified Tissue Engineered Blood Vessel for Endothelial Progenitor Cell Capture and Targeted siRNA Delivery

Instability and poor targeting causes the long-term patency of RNA-modified tissue engineering blood vessels (TEBVs) remaining unsatisfactory. RNA can be enriched in exosome and then delivered into targeted cells while whether exosome-modified TEBVs achieve RNA targeted delivery is unclear. Here, to promote the expression of klotho protein on the mesenchymal stem cell (MSC)-derived exosomes, klotho plasmids are first transfected into MSCs, and adenosine kinase (ADK) siRNA is then loaded into exosome (klotho/ADK siRNA-exosome) using electrotransfection. Flow chamber results show that klotho/ADK siRNA-exosome can effectively capture circulating endothelial progenitor cells (EPCs). Besides, the captured EPCs can endocytose this exosome, and then decompose it into klotho protein and ADK siRNA. Moreover, ADK siRNA promotes the paracrine of proangiogenic factors and adenosine from EPCs, which further facilitate proliferation and migration of endothelial cells. Based on polyethyleneimine-capped gold nanoparticles, exosome-modified TEBVs are constructed through layer-by-layer assembly. Animal experimental results show that klotho/ADK siRNA-exosome-modified TEBVs can maintain the patency up to one month, and good endothelialization is observed. In short, one exosome-modified TEBV is constructed, capture molecules on the surface of exosome capture the circulating EPCs, and the loaded RNA achieves its purpose of accurate treatment depending on the needs of patients.

Efficacy and safety of duloxetine in Chinese patients with chronic pain due to osteoarthritis: a randomized, double-blind, placebo-controlled study

OBJECTIVE

We assessed the efficacy and safety of duloxetine (60 mg, once daily), compared with placebo, during a 13-week treatment period in Chinese patients with chronic pain due to osteoarthritis (OA).

DESIGN

Patients were at least 40 years old (male or female) who met American College of Rheumatology clinical and radiographic criteria for the diagnosis of OA of the knee or hip. The primary efficacy measure in this phase 3, randomized, double-blind, placebo-controlled clinical trial was assessment of pain severity by the Brief Pain Inventory (BPI) 24-h Average Pain rating. The clinical trial was conducted at 17 study centers. Statistical approaches included mixed-effects model repeated measures and analysis of covariance. A Fisher exact test was applied to categorical variables.

RESULTS

Of 407 patients randomized (duloxetine: N = 205; placebo: N = 202), 166 (81.0%) patients from the duloxetine group and 176 (87.1%) patients from the placebo group completed the 13-week treatment phase. The majority (76.4%) of patients was female; mean age was 60.5 years. Duloxetine-treated patients reported significant pain reduction, compared with placebo treatment, on the BPI 24-h Average Pain rating (least-squares mean (LS Mean) change from baseline to endpoint [95% confidence interval (CI)], duloxetine: -2.23; placebo: -1.73; difference = -0.50 [-0.80, -0.20]; P = 0.001). The incidence of discontinuations due to adverse events was 9.0% in duloxetine-treated patients and 4.5% in placebo-treated patients (P = 0.109).

CONCLUSIONS

This study demonstrated the efficacy of duloxetine in Chinese patients with chronic pain due to OA. The safety profile of duloxetine observed in this study was consistent with that in previous duloxetine trials. This trial is registered with ClinicalTrials.gov (NCT01931475).

Genetic polymorphisms in ERCC1 and ERCC2 genes are associated with response to chemotherapy in osteosarcoma patients among Chinese population: a meta-analysis

BACKGROUND

There existed controversies about the association between the response to chemotherapy for osteosarcoma (OS) patients and the genetic polymorphisms in excision repair cross-complementation group (ERCC1 and ERCC2) genes. We aimed to perform a meta-analysis to comprehensively evaluate the association.

METHOD

We searched multiple databases for literature retrieval including the PubMED (1966 ∼ 2017), Embase (1980 ∼ 2017), and the Web of science (1945 ∼ 2017). The overall odds ratios(OR) and their corresponding 95% confidence interval (CI) were calculated for the three polymorphisms under the dominant, recessive, and allelic models.

RESULTS

From six eligible articles in our study, we found that for ERCC1 rs11615 polymorphism, a significant association was detected between the chemotherapy response and the polymorphism under all three models (dominant model: OR = 2.015, P = 0.005; recessive model: OR = 1.791, P = 0.003; allelic model: OR = 1.677, P = 0.003), and OS patients carrying C allele in rs11615 polymorphism were more likely to response to chemotherapy. In terms of ERCC2 rs1799793 polymorphism, this polymorphism was significantly associated with the response to chemotherapy for OS patients under recessive model (OR = 1.337, P = 0.036), and patients with AG + AA genotype in rs1799793 polymorphism were more appropriate to receive chemotherapy. With respect to ERCC2 rs13181 polymorphism, this polymorphism was not correlated with the response to chemotherapy for OS patients under all three models.

CONCLUSIONS

Our meta-analysis suggested that among Chinese population, the rs11615 and rs1799793 polymorphisms were significantly correlated with the response to chemotherapy for patients with OS, and patients with CC or TC + CC genotypes in ERCC1 rs11615 polymorphism or AG + AA genotype in ERCC2 rs1799793 polymorphism were more suitable for chemotherapy.

Epithelial Microvesicles Promote an Inflammatory Phenotype in Fibroblasts

Microvesicles (MVs) are extracellular vesicles secreted by various cell types that are involved in intercellular communication. We hypothesized that in human periodontal disease, the pocket epithelium releases MVs, which then modulate gene expression in the underlying fibroblasts to control periodontal inflammation. MVs were isolated from culture medium of gingival epithelial cells (GECs) treated with oral bacterial biofilm extract or left untreated. Biofilm treatment significantly increased MV release from the GECs. Mass spectrometry of GEC-MVs identified a total of 2,173 proteins, of which about 80% were detected in MVs from both control and biofilm-treated GECs. Among 80 signature genes of human gingival fibroblasts, 20 were significantly regulated ( P < 0.05) by MVs from control and biofilm-treated GECs in a similar manner. Matrix metalloproteinase 1 and 3 and interleukin 6 and 8 showed the strongest regulation at the mRNA and protein levels. Several cellular signaling pathways were activated by GEC-MVs in human gingival fibroblasts, including Smad and mitogen-activated protein kinase–associated pathways ERK1/2, JNK, and p38. However, ERK1/2 signaling dominated in the MV-induced gene expression changes. The results demonstrate that GEC-MVs have a strong regulatory effect on the expression of fibroblast genes associated with inflammation and matrix degradation and that bacterial biofilm stimulates the generation of GEC-MVs. This suggests that bacterial biofilms can contribute to the initiation and progression of periodontal disease by promoting a tissue-destructive phenotype in gingival fibroblasts via the enhanced secretion of epithelial MVs.

Mutations of glucocerebrosidase gene and susceptibility to Parkinson's disease: An updated meta-analysis in a European population

This meta-analysis aims to investigate the association between mutations of glucocerebrosidase (GBA) gene and susceptibility to Parkinson's disease (PD) in a European population. Several electronic databases were extensively searched. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association. In total, fourteen published papers screening L444P, N370S and other GBA variants were identified. The GBA mutations were significantly associated with PD in the European population. Subgroup analysis stratified by the age of onset (AAO) revealed that the association between GBA mutations and PD existed in the patients with age at onset ⩽50 years but did not exist in the patients with age at onset >50 years. Furthermore, the associations between N370S, and L444P with PD were also analyzed to explore the roles of the two most frequent GBA mutations in the development of PD. The results showed that significant associations between N370S, and L444P with PD were observed, respectively. Overall, the study supported that GBA mutations were a risk factor for PD in the European population. Patients with early-onset were more likely to carry GBA mutations than those with late-onset. Moreover, both L444P and N370S were associated with increased PD risk.

Chinese SLE Treatment and Research group (CSTAR) registry VII: prevalence and clinical significance of serositis in Chinese patients with systemic lupus erythematosus

Objectives

To investigate both the prevalence and clinical characteristics of serositis in Chinese patients with systemic lupus erythematosus (SLE) in a large cohort in the Chinese SLE Treatment and Research group (CSTAR) database.

Methods

A prospective cross-sectional study of patients with SLE was conducted based on the data from the CSTAR registry. Serositis was defined according to the 1999 revised American College of Rheumatology (ACR) criteria for SLE – that is, pleuritis/pleural effusion and/or pericarditis/pericardial effusion detected by echocardiography, chest X-ray or chest computerized tomography (CT) scan. Peritonitis/peritoneal effusion were confirmed by abdominal ultrasonography. We analysed the prevalence and clinical associations of serositis with demographic data, organ involvements, laboratory findings and SLE disease activity.

Results

Of 2104 patients with SLE, 345 were diagnosed with serositis. The prevalence of lupus nephritis (LN), interstitial lung disease and pulmonary arterial hypertension, as well as the presence of leukocytopenia, thrombocytopenia, hypocomplementemia and anti-dsDNA antibodies was significantly higher in patients with serositis ( P < 0.05). Significantly higher SLE disease activity scores were found in patients with serositis compared to those patients without serositis ( P < 0.05). Lupus-related peritonitis had similar clinical manifestations and laboratory profiles as serositis caused by SLE.

Conclusions

There is a significant association of nephropathy, interstitial lung disease, pulmonary arterial hypertension, hypocomplementemia, leukocytopenia, thrombocytopenia and elevated anti-dsDNA antibodies with serositis. The results suggest that higher SLE disease activity contributes to serositis development, and should be treated aggressively.

A rat model designed for the continuous intraarterial infusion of cyclosporine

BACKGROUND

Limb allotransplantation is not a life-saving treatment. However, large doses of immunosuppressive agents are needed. There is an urgent need to increase the selectivity and targeting of drugs.

METHODS

We designed a rat model for intraarterial infusion of cyclosporine (CSA) based on the hindlimb replanted model to simulate the limb allotransplantation. To investigate whether intraartery infusion could improve the drug's distribution, we infused CSA 4.0 mg/kg per day continuously into either the superficial epigastric artery (IA group) or superficial epigastric vein (IV group) of Lewis rats.

RESULTS

On day 10, CSA concentrations were measured in skin, muscle, and bone tissues of hindlimb. Samples were taken from different parts of the bilateral hindlimbs in the IA group and right hindlimb only in the IV group. Tissue concentrations of the perfusion side were much higher in IA group. Systemic concentrations of IA group were higher than IV group.

CONCLUSIONS

These results warrant further research in our next limb allotransplantation model.

Toll-like receptor 4 confers inflammatory response to Suilysin

Streptococcus suis serotype 2 (SS2) is an emerging human pathogen worldwide. A large outbreak occurred in the summer of 2005 in China. Serum samples from this outbreak revealed that levels of the main proinflammatory cytokines were significantly higher in patients with streptococcal toxic-shock-like syndrome (STSLS) than in patients with meningitis only. However, the mechanism underlying the cytokine storm in STSLS caused by SS2 remained unclear. In this study, we found that suilysin (SLY) is the main protein inflammatory stimulus of SS2 and that native SLY (nSLY) stimulated cytokines independently of its haemolytic ability. Interestingly, a small amount of SLY (Å Mol/L) induced strong, long-term TNF-α release from human PBMCs. We also found that nSLY stimulated TNF-α in wild-type macrophages but not in macrophages from mice that carried a spontaneous mutation in TLR4 (P712H). We demonstrated for the first time that SLY stimulates immune cells through TLR4. In addition, the Myd88 adaptor-p38-MAPK pathway was involved in this process. The present study suggested that the TLR4-dependent inflammatory responses induced by SLY in host might contribute to the STSLS caused by SS2 and that p38-MAPK could be used as a target to control the release of excess TNF-α induced by SS2.

Chinese SLE Treatment and Research group (CSTAR) registry: V. gender impact on Chinese patients with systemic lupus erythematosus

Introduction

Many studies have shown that differences were observed between male and female lupus patients. Although systemic lupus erythematosus (SLE) affects mostly females (female:male ratio 9:1), male SLE patients show higher mortality due to kidney and neurological disease. Currently there are limited epidemiological data concerning lupus in the Chinese population. As such, the Chinese SLE Treatment and Research group (CSTAR) developed the first online registry of Chinese lupus patients in 2009, and represents a multicenter observational study that attempts to describe and compile the major clinical characteristics of lupus in Chinese patients.

Objective

To investigate the effect of gender on the phenotypes of Chinese SLE patients.

Patients and methods

Data for 2104 SLE patients were prospectively collected and included in the CSTAR registry. Patients fulfilled the 1997 American College of Rheumatology (ACR) SLE classification criteria. We conducted a cross-sectional case-control study to analyze patient clinical and laboratory data at onset and at enrollment. SLE disease activity scores (SLEDAI) were also measured at enrollment.

Results

This study included 1914 women and 190 men. Males and females showed no differences in mean ages at onset, delay of diagnosis and disease duration. Males presented more frequently with fever ( p = 0.003), while musculoskeletal involvement ( p = 0.001) and cytopenia ( p = 0.017) was more common in females as the initial manifestation at onset of SLE. For manifestations at enrollment, males presented more frequently with fever ( p = 0.005), renal disease ( p = 0.019), vasculitis ( p = 0.032) and neuropsychiatric lupus ( p = 0.007). For cumulative manifestations at enrollment, males presented more frequently with discoid rash ( p < 0.001) and neuropsychiatric lupus ( p = 0.036), while less frequently with arthritis ( p = 0.011). However, the laboratory data showed no significant differences between the two groups at enrollment. Males also had higher SLEDAI scores at enrollment ( p = 0.002).

Conclusions

Renal disease, vasculitis and neuropsychiatric lupus are more common in male SLE patients with higher SLEDAI scores compared to female SLE patients in China.

INHIBITORY EFFECT OF TETRAMETHYLPYRAZINE ON HEPATOCELLULAR CARCINOMA: POSSIBLE ROLE OF APOPTOSIS AND CELL CYCLE ARREST

Hepatocellular carcinoma (HCC) is the fifth most common cancer. An important approach to control HCC is chemoprevention. This study aims at investigating the antitumor effect of Tetramethylpyrazine (TMP). Rats were injected with N-Nitrosodiethylamine (DEN) to establish HCC. Tumor development was observed. Liver function was evaluated. Apoptosis and cell cycle arrest-related makers and signaling cascades were determined by Western blot, RT-PCR and flow cytometric analysis. The administration of TMP could significantly inhibit tumor development in DEN-induced HCC rats, shown by reduced incidence of tumor, decreased number of tumor nodules and reduced maximal size of tumor. DEN-induced increase of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and alkaline phosphatase activities were significantly inhibited by TMP. TMP exhibited inhibitory effect on HCC through induction of apoptosis and cell cycle arrest in rats. TMP induced apoptosis through increasing Bax, decreasing Bcl-2, increasing the release of cytochrome c, and activating caspase, which consisted of the mitochondrial apoptotic pathway. TMP induced G2/M cell cycle arrest through down-regulation of cyclin B1/cdc2. In addition, inhibition of Akt and ERK signaling and the antioxidant activities of TMP may also contribute to its antitumor effect. These data provide new insight into the mechanisms underlying the antitumor effect of TMP.

Disturbance of hippocampal H2S generation contributes to CUMS-induced depression-like behavior: involvement in endoplasmic reticulum stress of hippocampus

The chronic unpredictable mild stress (CUMS) model is a widely used experimental model of depression. Exogenous stress-induced neuronal cell death in the hippocampus is closely associated with the pathogenesis of depression. Excessive and prolonged endoplasmic reticulum (ER) stress triggers cell death. Hydrogen sulfide (H2S), the third endogenous signaling gasotransmitter, plays an important role in brain functions as a neuromodulator and a neuroprotectant. We hypothesized that the disturbance of endogenous H2S generation and ER stress in the hippocampus might be involved in CUMS-induced depression-like behaviors. Thus, the present study focused on whether CUMS disturbs the generation of endogenous H2S and up-regulates ER stress in the hippocampus and whether exogenous H2S prevents CUMS-induced depressive-like behaviors. Results showed that CUMS-treated rats exhibit depression-like behavior and hippocampal ER stress responses including up-regulated levels of glucose-regulated protein 78, CCAAT/enhancer binding protein homologous protein, and cleaved caspase-12 expression, while the endogenous generation of H2S in the hippocampus is suppressed in CUMS-treated rats. Furthermore, exogenous H2S prevents CUMS-induced depression-like behavior. These data indicated that CUMS-induced depression-like behaviors are related to the disturbance of endogenous H2S generation and ER stress in the hippocampus and suggested that endogenous H2S and ER stress are novel treatment targets of depression.

Increased production of suilysin contributes to invasive infection of the Streptococcus suis strain 05ZYH33

Streptococcus suis serotype 2 (SS2) is widely recognized in the veterinary world as the cause of rapidly progressive and fatal sepsis in infant pigs, manifested with meningitis, polyarthritis and pneumonia. It has evolved into a highly infectious strain, and caused two large-scale outbreaks of human epidemic in China, characterized bytypical toxic-shock syndrome and invasive infection. However, the molecular basis of virulence of this emerging zoonotic pathogen is still largely unknown. The present study shows that the sequence type (ST)7 epidemic strain S. suis 05ZYH33 causes higher mortality, higher necrosis of polymorphonuclear neutrophils and a significantly higher damage to human umbilical vein endothelial cells compared to the non-epidemic strain S. suis 1940. These differences appear to associate with the enhanced secretion of suilysin (sly) by S. suis 05ZYH33 compared to the non-epidemic strain 1940. Inclusion of additional strains confirmed that the epidemic ST7 strains produce more sly protein (mean, 1.49 g/ml; range, 0.76–1.91 g/ml) than non-epidemic strains (mean, 0.33 g/ml; range, 0.07–0.94 g/ml), and this difference is significant (P<0.001). The nonpolar mutant strain S. suis Δsly, constructed from the epidemic ST7 strain S. suis 05ZYH33 confirmed the role of sly on the enhanced virulence of S. suis ST7 strains. These findings suggest that increased sly production in S. suis 05ZYH33 facilitates penetration to the epithelium and its survival in the bloodstream, thereby contributing to the invasive infection.

Gene expression profile of type II spinal cord decompression sickness

STUDY DESIGN

This study was an experimental, controlled, animal study.

OBJECTIVE

This study was to determine the changes of molecular pathology in spinal cord decompression sickness (SC-DCS) based on a rabbit model of SC-DCS with the aid of an all-gene expression profile chip.

SETTING

Qingdao, Shandong Province, China.

METHODS

A gene expression profile chip containing 43 803 genes was used to compare the gene expressions in the spinal cords of four male New Zealand white rabbits in the SC-DCS and control groups, respectively. Selected differentially expressed genes were identified with quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry.

RESULTS

The chip hybridization results showed that the SC-DCS group had nine upregulated and seventeen downregulated genes, compared with the control group. These genes were mainly related to inflammation, ion channels, the cell cycle, material transfer and apoptosis. The qRT-PCR results showed that parathyroid hormone and tumor necrosis factor alpha (TNF-α) genes were upregulated compared with the control group (P<0.01). However, the acyl-CoA synthetase and voltage-gated channel genes were downregulated (P<0.05). The immunohistochemical staining results confirmed that there were significantly greater expression levels of TNF-α in the spinal cord tissues of the SC-DCS group compared with the control group.

CONCLUSIONS

The spinal cord lesions of SC-DCS involve multiple gene changes in the rabbit; however, the significance of these findings needs further research. Meanwhile, the gene expression profile chip results provide us with a better understanding of the pathogenesis of DCS.

Abstract P5-03-14: Expression of ALDH1 in metastasizing axillary lymphnodes in breast cancer

Background: There is increasing evidences that a wide variety of malignancies, including breast cancer, may be driven by a small subset of ‘tumor-initiating cells’ or ‘cancer stem cells’ (CSC) which are able to form tumors in immunocompromised mice as well as to generate the phenotypic heterogeneity of the initial tumor. Enzyme aldehyde dehydrogenase (ALDH1) has been reported as a possible marker for mammary CSC. These cells are a source of tumor recurrence and metastasis, and are resistant to chemotherapy, radiotherapy and hormone therapy.

Objective: Assuming that the detection of CSC in axillary lymph nodes is more effective to predicting cancer outcome than the widely used detection of cancer cells in axillary lymph nodes, we measure ALDH1 levels to predict their presence into axillary lymph nodes on development of cancer and anticipate outcomes.

Methods: ALDH1 protein was detected by an immunohistochemical technique in 229 cases of breast cancer diagnosed from 2002 to 2011 Follow-up ranged from 11.5 months to 96.9 months, with a mean of 73.9 months. A survival assay was used to determine the relationship between distant metastatic rate and survival rate.

Results: ALDHl expression was detected in 79cases and the Positive rate in metastatic axillary lymph nodes was 34.5%. Negative ER, PR status were related to the ALDH1 positive cases(P = 0.012). See Table 1. Mortality rate between ALDH1 positive cases (50.8%) and negative cases (28.8%) were significantly different (P = 0.001). See Table 2. Further, survival analysis of recurrence-free survivals (RFS) and survival rate decreased significantly between ALDHl positive and negative cases (P = 0.001) (see table 2) and COX analysis shows that ALDH1 expression is an independent predictor of poor outcome in breast cancer(P = 0.011).

Discussion: What cancer stem cells migrate to the axillary nodes have more important prediction than that the matastesis of normal cancar cells in axillary node. It might be a role resulting in dying in breast cancer.

Mitigation of thoron exposure by application of wallpaper as a diffusion barrier

Increasing attention has been paid in recent years to the radioactive gas thoron ((220)Rn), which can cause a significant exposure and increase of lung cancer risk in some regions worldwide. Some experiments were designed to examine whether different types of wall decoration in the room, from ordinary newsprint to commercial wallpaper, can mitigate the concentrations of indoor thoron decay products. Decoration with coated paper was very effective in decreasing the thoron decay products concentration, thus reducing the effective dose by 90 %, while newsprint decoration, which is common in many rural parts of the world, was found to have a smaller but still significant effect in reducing the thoron decay products concentration when applied to the same house.

Baifuzi reduces transient ischemic brain damage through an interaction with the STREX domain of BKCa channels

Stroke is a long-term disability and one of the leading causes of death. However, no successful therapeutic intervention is available for the majority of stroke patients. In this study, we explored a traditional Chinese medicine Baifuzi (Typhonium giganteum Engl.). We show, at first, that the ethanol extract of Baifuzi exerts neuroprotective effects against brain damage induced by transient global or focal cerebral ischemia in rats and mice. Second, the extract activated large-conductance Ca(2+)-activated K(+) channel (BK(Ca)) channels, and BK(Ca) channel blockade suppressed the neuroprotection of the extract, suggesting that the BK(Ca) is the molecular target of Baifuzi. Third, Baifuzi cerebroside (Baifuzi-CB), purified from its ethanol extract, activated BK(Ca) channels in a manner similar to that of the extract. Fourth, the stress axis hormone-regulated exon (STREX) domain of the BK(Ca) channel directly interacted with Baifuzi-CB, and its deletion suppressed channel activation by Baifuzi-CB. These results indicate that Baifuzi-CB activated the BK(Ca) channel through its direct interaction with the STREX domain of the channel and suggests that Baifuzi-CB merits exploration as a potential therapeutic agent for treating brain ischemia.

Development of a new thoron progeny detector based on SSNTD and the collection by an electric field

The importance of (220)Rn (thoron) progeny for human exposure has been widely recognised in the past decades. Since no stable equilibrium factor was found between indoor thoron and its progeny, and the concentration of thoron progeny varies with time, it is necessary to develop detectors for long-term measurement that directly sample and detect thoron progeny. However, power supply of this kind of detectors has always been a problem. In this study, a set of device that is suitable for long-term measurement is introduced. A high-voltage electric field was formed for the collection of charged aerosols attached by (222)Rn (radon) and thoron progenies on solid-state nuclear track detector. Impact from radon progeny could be eliminated with a shield of Al foil of appropriate thickness. Tests were made both in an experimental house and in a thoron chamber in Helmholtz Zentrum München to determine the parameters and to verify the universality under different conditions.

Age and sex dependent inhalation doses to members of the public from indoor thoron progeny

The increased indoor thoron level in Europe, North America and Asia has shown that the exposure to thoron and its decay products cannot be ignored in some environments. The contribution of thoron and its progeny can be a significant component of the total exposure from radon and thoron. In the present paper, radiation dose assessment of members of the public of different age and sex exposed to (220)Rn progeny under different daily life activities is performed through a dosimetric approach. Dose conversion coefficients under typical indoor conditions were estimated to be in the range of 107 nSv (Bq h m(-3))(-1) for infant to 81.7 nSv (Bq h m(-3))(-1) for adult. The results of this work emphasized that small children receive a radiation dose of 25% more than adults under the same conditions, and people performing exercise receive a radiation dose 100% more than when sleeping. The results of this work are appropriate to the risk assessment of thoron exposure to members of the public who live in areas with high radon and thoron concentrations.

Application of LSC and TLD methods for the measurement of radon and thoron decay products in air

Liquid scintillation counting (LSC) is a measuring technique, broadly applied in environmental monitoring. One of the possible applications of LSC is the measurement of radon and thoron progeny. Such a method can be stated as an absolute one. For long-term measurements, a different technique can be applied-monitors of potential alpha energy concentration (PAEC) with thermoluminescent detectors (TLDs). Such solution enables simultaneous measurements of PAEC and dust content. Moreover, the information which is stored in TLD chips is the energy of alpha particles and not the number of counted particles. Therefore, the readout of TL detector directly shows the potential alpha energy, with no dependence on equilibrium factor, etc. This technique, which had been used only for radon progeny measurements, was modified to allow simultaneous measurements of radon and thoron PAEC.

Nucleotide excision repair/TFIIH helicases RAD3 and SSL2 inhibit short-sequence recombination and Ty1 retrotransposition by similar mechanisms

Eukaryotic genomes contain potentially unstable sequences whose rearrangement threatens genome structure and function. Here we show that certain mutant alleles of the nucleotide excision repair (NER)/TFIIH helicase genes RAD3 and SSL2 (RAD25) confer synthetic lethality and destabilize the Saccharomyces cerevisiae genome by increasing both short-sequence recombination and Ty1 retrotransposition. The rad3-G595R and ssl2-rtt mutations do not markedly alter Ty1 RNA or protein levels or target site specificity. However, these mutations cause an increase in the physical stability of broken DNA molecules and unincorporated Ty1 cDNA, which leads to higher levels of short-sequence recombination and Ty1 retrotransposition. Our results link components of the core NER/TFIIH complex with genome stability, homologous recombination, and host defense against Ty1 retrotransposition via a mechanism that involves DNA degradation.

Proliferative defect and embryonic lethality in mice homozygous for a deletion in the p110alpha subunit of phosphoinositide 3-kinase

Phosphatidylinositol 3,4,5-trisphosphate is a phospholipid signaling molecule involved in many cellular functions including growth factor receptor signaling, cytoskeletal organization, chemotaxis, apoptosis, and protein trafficking. Phosphorylation at the 3 position of the inositol ring is catalyzed by many different 3-kinases (classified as types IA, IB, II, and III), but the physiological roles played by each of the different 3-kinase isozymes during embryonic development and in homeostasis in animals is incompletely understood. Mammalian type IA kinase isozymes are heterodimers that are active at 37 degrees C when the catalytic 110-kDa subunit interacts through an amino-terminal binding domain with a regulatory 85- or 55-kDa subunit. Using gene targeting in embryonic stem cells, we deleted this binding domain in the gene encoding the alpha isoform of the 110-kDa catalytic subunit (Pik3ca) of the alpha isozyme of the type IA kinases, leading to loss of expression of the p110 catalytic subunit. We show that Pik3cadel/del embryos are developmentally delayed at embryonic day (E) 9.5 and die between E9.5 and E10.5. E9. 5 Pik3cadel/del embryos have a profound proliferative defect but no increase in apoptosis. A proliferative defect is supported by the observation that fibroblasts from Pik3cadel/del embryos fail to replicate in Dulbecco's modified Eagle's medium and fetal calf serum, even with supplemental growth factors.

Inhibitor antibody development and T cell response to human factor VIII in murine hemophilia A

In order to understand better the mechanism of inhibitor formation in hemophilia A patients, we have characterized the immune response to human factor VIII in a murine model of hemophilia A. Mice with severe factor VIII deficiency caused by targeted gene disruptions in exons 16 and 17 were injected intravenously with human factor VIII. Anti-factor VIII was absent or was detected at only very low levels in hemophilic mice of both strains after a single injection of 0.2 microg factor VIII, but it was present in most mice after a second exposure. Subsequent exposures led to high titer anti-factor VIII antibodies in both ELISA and inhibitor assays. A human factor VIII-specific T cell proliferative response was detected with spleen cells obtained three days after a single injection with human factor VIII, before mice had detectable anti-factor VIII antibodies. Subsequent exposures to factor VIII were followed by an increased T cell proliferative response. These studies indicate that murine hemophilia A is a good model for the study of the immune response to human factor VIII, especially the role of the T cell in the early steps in inhibitor antibody formation.

[The clinical study on labor pain relief using two kinds of segmental block anesthesia]

OBJECTIVE

To study the pain relief effectiveness of combined subarachnoid peridural segmental block and simple peridural anesthesia, and their influences on the mothers and the infants.

METHODS

100 pregnants women were administered combined subarachnoid and peridural segmental block during labor and delivery (study group). 40 pregnant women received simple peridural anesthesia (control group). The degree of labour pain, side effects, labor course, the mode of delivery and the incidences of postpartum hemorrhage, fetal distress and neonatal asphyxia were observed in two groups respectively.

RESULTS

The pain relief effect in the study group was much better than that of the control group (P < 0.01). There were no significant differences of the mean time of labor course and the mode of delivery between the two groups (P > 0.05). The incidences of postpartum hemorrhage, fetal distress and neonatal asphyxia were similar (P > 0.05).

CONCLUSION

The analgesic delivery of combined subarachnoid and peridural segmental block is safe and effective, which has no influences on the labour course and the mothers and infants. Its pain relief effectiveness is more positive and satisfactory than that of simple peridural anesthesia. We suggest that it should be performed in the medical units under optimal conditions.

[High-level expression of human immunodeficiency virus type 1 gp120 protein in E. coli]

In order to improve protein expression and to produce good and cheap diagnostic antigen, the gene fragment (560bp) in N-terminal of gp120 of HIV-1 LAV strain was amplified by PCR. After digested by EcoR I and Sal I, the fragment was cloned into a high-level expression vector pET28a. The recombinant plasmid pET/120 transfecting BL21 (DE3) produced the protein with high-level expression in the host cell BL21(DE3), which was further proved having good antigenicity and high specificity by indirect ELISA and Western-blot assay. The protein expressed was about 50% of the total bacterial protein by SDS-PAGE electrophoresis test. It was highly expressed in the prokaryotic expression system.

[Effect of trichosanthin of cell cycle and apoptosis of murine melanoma cells]

OBJECTIVE

To study the inhibitory effect of purified trichosanthin component on the proliferation of malignant melanoma.

METHODS

The effect of purified trichosanthin component on the DNA synthesis, cell cycle and cell apoptosis of murine melanoma cells were detected by flowcytometry when cultured in vitro.

RESULTS

The significant G0/G1 phase arrest was revealed by the increase of cells in G0/G1 phase and decrease of cells in S phase. The obvious apoptosis of melanoma cells was induced by purified trichosanthin component. G0/G1 phase arrest was highly correlated with apoptosis (r = 0.8705).

CONCLUSIONS

The purified trichosanthin component can markedly inhibit melanoma cells by the suppression of DNA synthesis in S phase and cell mitosis as well as induction of cell apoptosis.

Further characterization of factor VIII-deficient mice created by gene targeting: RNA and protein studies

Previously we created two strains of factor VIII-deficient mice by insertion of a neo gene into (1) the 3' end of exon 16 and (2) exon 17 of the factor VIII gene. Affected mice of both strains have no plasma factor VIII activity, yet are healthy with no spontaneous bleeding. Factor VIII-deficient females bred with affected males survive pregnancy and delivery. We used reverse transcriptase-polymerase chain reaction of liver RNA to characterize factor VIII mRNA processing. Factor VIII mRNA of the exon 16 knockout strain contains neo sequences plus 17 bp of intron 16 due to use of a cryptic donor site in intron 16. All factor VIII mRNA of the exon 17 knockout strain lacks exon 17 and neo sequences. In skipping exon 17, the intron 16 donor site or a cryptic donor site 46 bp 3' to the intron 16 donor site are used. Thus, factor VIII deficiency in exon 16 knockout mice is due to truncated protein, while in exon 17 knockout mice it is due to either truncated or partially deleted protein. After immunizing exon 16 knockout mice with human recombinant factor VIII, two monoclonal antibodies were obtained that recognize < 100 pg of mouse factor VIII light chain. Assay of cryoprecipitate from the plasma of affected mice failed to show factor VIII light chain.

Targeted disruption of the mouse factor VIII gene produces a model of haemophilia A

Haemophilia A is a classic X-linked disease which affects 1 in 5-10,000 males in all populations and is caused by defects in coagulation factor VIII. Roughly 60% of patients have severe disease with factor VIII activity < 1% of normal; they have frequent spontaneous bleeding into joints, soft tissues, muscles and internal organs. These patients usually require regular injections of plasma-derived or recombinant human factor VIII. Because this is expensive and can potentially lead to life-threatening complications, other forms of therapy, including gene therapy, have been proposed. Natural canine models of factor VIII and factor IX deficiency have been available for many years, and gene therapy attempts on these dogs have met with partial success. However, a small animal model of the disease is desirable for studies of factor VIII function and gene therapy. Using gene targeting, we have made a mouse with severe factor VIII deficiency.