[Analysis of therapeutic mechanism of Liushen Wan against colitis-associated colorectal cancer based on network pharmacology and validation in mice]

OBJECTIVE

To explore the therapeutic mechanism of Liushen Wan (LSW) against colitis-associated colorectal cancer (CAC) by network pharmacology.

METHODS

TCMSP, BATMAN-TCM, CNKI, PubMed, Genecards, OMIM, and TTD databases were used to obtain the related targets of LSW and CAC. The common targets of LSW and CAC were obtained using Venny online website. The PPI network was constructed using Cytoscape 3.8.2 to screen the core targets of LSW in the treatment of CAC. GO and KEGG enrichment analysis were conducted using DAVID database. The therapeutic effect of LSW on CAC was evaluated in a C57BL/6J mouse model of AOM/DSS-induced CAC by observing the changes in body weight, disease activity index, colon length, and size and number of the tumor. HE staining and RT-qPCR were used to analyze the effect of LSW on inflammatory mediators. Immunohistochemistry and TUNEL staining were used to evaluate the effect of LSW on the proliferation and apoptosis of AOM/DSS-treated colon tumor cells. Immunohistochemistry and Western blotting were used to detect the effects of LSW on the expression of TLR4 proteins in CAC mice.

RESULTS

Network pharmacology analysis identified 69 common targets of LSW and CAC, and 33 hub targets were screened in the PPI network. KEGG pathway enrichment analysis suggested that the effect of LSW on CAC was mediated by the Toll-like receptor signaling pathway. In the mouse model of AOM/DSS-induced CAC, LSW significantly inhibited colitis-associated tumorigenesis, reduced tumor number and tumor load (P < 0.05), obviously improved histopathological changes in the colon, downregulated the mRNA levels of proinflammatory cytokines, and inhibited the proliferation (P < 0.01) and promoted apoptosis of colon tumor cells (P < 0.001). LSW also significantly decreased TLR4 protein expression in the colon tissue (P < 0.05).

CONCLUSION

LSW can inhibit CAC in mice possibly by regulating the expression of TLR4 to reduce intestinal inflammation, inhibit colon tumor cell proliferation and promote their apoptosis.

MRI features and whole-lesion apparent diffusion coefficient histogram analysis of brain metastasis from non-small cell lung cancer for differentiating epidermal growth factor receptor mutation status

AIM

To explore the utility of magnetic resonance imaging (MRI) characteristics and whole-lesion apparent diffusion coefficient histogram analysis of brain metastasis from non-small cell lung cancer (NSCLC) in the differentiation of epidermal growth factor receptor (EGFR) mutation status.

MATERIALS AND METHODS

Forty-eight patients with brain metastases from NSCLC were enrolled in this retrospective study. Patients were subtyped into EGFR mutation (23 cases) and wild-type (25 cases) groups. Whole-lesion histogram metrics were derived from the apparent diffusion coefficient (ADC) maps, and imaging features were evaluated according to conventional MRI. Student's t-test or Mann-Whitney U-test, chi-squared test, and receiver operating characteristic (ROC) curve analysis were performed to discriminate the two groups and to determine the diagnostic efficacy of ADC histogram parameters.

RESULTS

EGFR mutation group had more multiple brain metastases, less peritumoural brain oedema (PTBO), and lower peritumoural brain oedema index (PTBO-I) than EGFR wild-type group (all p<0.05). In addition, 90th and 75th percentiles of ADC and maximum ADC in the EGFR mutation group were significantly higher than in the EGFR wild-type group (all p<0.05). Ninetieth percentile of ADC had the highest area under the curve (AUC; 0.711), and it was found to outperform 75th percentile of ADC (AUC, 0.662; p=0.039) and maximum ADC (AUC, 0.681).

CONCLUSIONS

Whole-lesion ADC histogram analysis and MRI features of brain metastasis from NSCLC are expected to be potential biomarkers to non-invasively differentiate the EGFR mutation status.

[Clinical significance and management strategies of low-level viremia during the treatment of chronic hepatitis B]

Chronic hepatitis B and its related complications seriously endanger the lives and health of our country people. Although the first-line nucleos(t)ide analogs such as entecavir, tenofovir disoproxil fumarate and tenofovir alafenamide fumarate can inhibit virus replication to a certain extent, delay or prevent disease progression, and reduce the incidence of hepatitis B-related liver cancer, but in clinical practice, HBV DNA positivity is still detected continuously or intermittently in the serum of some patients. Therefore, low-level viremia has received widespread attention and triggered discussion, and has become the difficulties and hotspot of antiviral treatment of chronic hepatitis B. This article summarizes and discusses the definition and incidence in line with the main guidelines and studies, impact of disease control and clinical prognosis, and the current treatment options in order to provide definite reference for the management of low-level viremia during antiviral therapy in patients with chronic hepatitis B.

[Transcription factor EB related autophagy in the treatment of multiple myeloma and its mechanism]

目的

明确硼替佐米和（或）西拉美新作用于多发性骨髓瘤（MM）细胞株后细胞增殖、转录因子EB（TFEB）核转位表达变化及自噬水平，为进一步探讨TFEB对自噬的调控机制提供依据。

方法

体外培养MM细胞株RPMI8226及U266，并以一定浓度的硼替佐米和西拉美新处理MM细胞，CCK-8法检测细胞增殖，实时定量PCR和Western blot法检测TFEB、自噬相关因子LC3B、Beclin1、p62、LAMP1的mRNA和蛋白相对表达量。

结果

随着硼替佐米浓度增加及作用时间延长，两个细胞系的增殖抑制率增高（P<0.05）。硼替佐米和西拉美新联用对上述MM细胞株的增殖有协同抑制作用（P<0.05）。空白对照组、单药组、联合用药组处理MM细胞株后，细胞质中TFEB的mRNA和蛋白相对表达量依次下降（P<0.05），细胞核中TFEB的mRNA和蛋白相对表达量依次上升（P<0.05），自噬相关因子LC3B、Beclin1、LAMP1的mRNA和蛋白相对表达量依次上升，p62的mRNA和蛋白相对表达量依次下降（P<0.05）。

结论

硼替佐米和西拉美新具有协同抑制MM细胞增殖作用，与其诱导MM细胞株自噬表达增强相关，发生核转位的TFEB表达亦增强。

[Role of the liver-enriched transcription factor binding site mutation in the C promoter region of hepatitis B virus genome for HBx-enhanced hepatitis B virus replication]

Objective: To construct a recombinant HBV replication-type plasmid with liver-enriched transcription factor binding site mutation at proximal of HBV C promoter in order to elucidate the role of HBx-enhanced HBV replication. Methods: Site-directed mutagenesis technology was used to construct a recombinant plasmid with liver-enriched transcription factor binding site mutation at proximal of HBV C promoter on the basis of wild-type HBV replicating plasmid and HBV replicating plasmid lacking HBx expression. Subsequently, plasmid transfection was carried out in HBV liver cancer cell replication model and mouse replication model, and HBV replication intermediates of cells and mouse liver tissue were extracted for detection. Results: Based on the HBV replicating plasmid, the HBV replicating plasmid with liver-enriched transcription factor binding site mutation at proximal of HBV C promoter was successfully constructed. HBx-enhanced HBV replication were detected in both the HBV liver cancer replication model and the mouse replication model. After mutating liver-enriched transcription factor binding site mutation at proximal of HBV C promoter, the effect of HBx on the enhancement of HBV replication was not significantly affected. Conclusion: HBx may not enhance HBV replication through liver-enriched transcription factor binding site mutation at proximal of HBV C promoter. The role of other liver-enriched transcription factor binding sites in HBx-enhanced HBV replication needs further study.

PCAT1 promotes the proliferative and migratory potentials of ovarian cancer via targeting NEK2

OBJECTIVE

The aim of this study was to clarify the potential role of PCAT1 in the occurrence and development of ovarian cancer (OC).

PATIENTS AND METHODS

Expression levels of PCAT1 and NEK2 in OC tissues and cell lines were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). Correlation between PCAT1 expression with tumor stage and prognosis of OC patients was analyzed. Knockdown or over-expression of PCAT1 and NEK2 were achieved by siRNA or lentivirus transfection, respectively. Subsequently, cell viability, apoptosis, cell cycle progression and migration were determined by cell counting kit-8 (CCK-8), flow cytometry and transwell assay, respectively. Furthermore, the protein levels of relative genes in Wnt pathway were detected by Western blot.

RESULTS

PCAT1 was highly expressed in OC tissues and cell lines, especially in tumor tissues with stage III-IV compared with stage I-II. The prognosis of OC patients with higher expression of PCAT1 was significantly worse than those with lower expression. In vitro experiments confirmed that PCAT1 knockdown obviously inhibited proliferative and migratory potentials, whereas induced apoptosis of OC cells. No significant changes were observed in cell cycle progression of OC cells after knockdown or overexpression of PCAT1. Meanwhile, overexpression of PCAT1 remarkably upregulated the expression level of NEK2, which was the target gene of PCAT1. Interestingly, NEK2 knockdown could obviously suppress cell migration. Furthermore, Western blot results elucidated that PCAT1 knockdown could inhibit the protein levels of relative genes in Wnt pathway in OC cells.

CONCLUSIONS

PCAT1 was highly expressed in OC tissues than adjacent normal tissues. PCAT1 overexpression significantly promoted proliferative and migratory potentials, whereas inhibited apoptosis of OC cells through upregulating NEK2 expression via Wnt pathway.

CtIP contributes to non-homologous end joining formation through interacting with ligase IV and promotion of TMZ resistance in glioma cells

OBJECTIVE

C-terminal-binding protein interacting protein (CtIP) participates in a variety of DNA metabolisms and DNA double strand break repair (DSBR). The role of CtIP has been proven in facilitating end resection in homologous recombination (HR). This study aimed to investigate the role of CtIP in non-homologous end joining (NHEJ) formation.

MATERIALS AND METHODS

In this study CtIP deficient U87 cell line was generated by using CRISPR/Cas9 method. HR and NHEJ reporter assay were conducted in U87 cells. The cell viability of U87 cells was evaluated by using Sulforhodamine B (SRB) assay. Ionizing radiation assay and clonogenic survival assay were also conducted in this study. Bacteria expressed CtIP and ligase IV proteins were collected and purified. Affinity capture assay was conducted to observe the interactions between proteins.

RESULTS

Both of the temozolomide (TMZ)-resistant and CtIP deficient glioma cell lines were successfully generated. The results indicated that CtIP participated in NHEJ formation through interacting with ligase IV in glioma cells. CtIP significantly improved the NHEJ efficiency in glioma cells. The CtIP deficient glioma cells were sensitive to the treatment of DNA damaging drug (TMZ). Meanwhile, the CtIP deficiency significantly enhanced the sensitivity of glioma cells to the treatment of TMZ.

CONCLUSIONS

The present study indicated that CtIP contributed to NHEJ formation through interacting with IV and promotion of TMZ resistance in glioma cells via promoting DSBR efficiency.

Identification of Peripheral Blood and Menstrual Blood Based on the Expression Level of MicroRNAs and Discriminant Analysis

Objective To construct a discriminant analysis model based on the differential expression of multiple microRNAs （miRNAs） in two kinds of blood samples （peripheral blood and menstrual blood） and three non-blood samples （saliva, semen and vaginal secretion）, to form an identification solution for peripheral blood and menstrual blood. Methods Six kinds of miRNA （miR-451a, miR-144-3p, miR-144-5p, miR-214-3p, miR-203-3p and miR-205-5p） were selected from literature, the samples of five kinds of body fluids commonly seen in forensic practice （peripheral blood, menstrual blood, saliva, semen, vaginal secretion） were collected, then the samples were divided into training set and testing set and detected by SYBR Green real-time qPCR. A discriminant analysis model was set up based on the expression data of training set and the expression data of testing set was used to examine the accuracy of the model. Results A discriminant analysis statistical model that could distinguish blood samples from non-blood samples and distinguish peripheral blood samples from menstrual blood samples at the same time was successfully constructed. The identification accuracy of the model was over 99%. Conclusion This study provides a scientific and accurate identification strategy for forensic fluid identification of peripheral blood and menstrual blood samples and could be used in forensic practice.

[Observation of cosmetic effect of corneal interlamellar staining in patients with corneal leucoma]

Objective: To observe the clinical effect of corneal staining in patients with corneal leucoma. Methods: Restrospective case series study.Thirty eyes of 30 patients (17 males, 13 females) with corneal leucoma who underwent corneal interlamellar staining at Beijing Aier-Intech Eye Hospital from October 2014 to July 2018 were included. The mean age was 31.50±15.66 years. Postoperative follow-up was more than 1 year. All the patients underwent appearance examination, anterior segment examination with a slit lamp, B-scan examination and anterior segment OCT examination preoperatively and postoperatively. The effect of corneal staining, patient satisfaction and the incidence of complications were investigated. Results: The corneal epithelium of all the patients healed completely within 1-3 days after operation. The mean follow-up period was 30.68±18.02 months (range, 12.37-58.10 months). During the postoperative follow-up period, no staining permeation or inflammatory reaction in the anterior chamber occurred. The corneal color and appearance were well maintained in 18 patients (72.0%). Seven patients (28.0%) showed mild corneal color-fading. One patient was treated with enucleation and orbital hydroxyapatite implantation because of eye atrophy and corneal banding degeneration caused by the primary disease at 4 years after operation. The surgeon was satisfied with the improvement of the appearance of all cases; 22 patients (88.0%) were satisfied with the postoperative appearance. No significant complications were observed in all the cases. Conclusions: Corneal interlamellar staining is one of best choices for the treatment of corneal leucoma. It has advantages of quick postoperative recovery, long-standing color staining and good cosmetic effect. The operation is simple and easy to carry out and there is no obvious damage to eye tissues. (Chin J Ophthalmol, 2020, 56:465-472).

[Predictive value of cervical length measured by transvaginal ultrasound during the second and the third trimester of pregnancy for preterm birth in twin pregnancies]

Objective: To investigate the predictive value of cervical length (CL) measured by transvaginal ultrasound for preterm birth <32 weeks, <34 weeks in twin pregnancies in the second and the third trimester of pregnancy. Methods: A total of 490 twin pregnant women with CL measured by transvaginal ultrasound during the second trimester of pregnancy (20-24 weeks) and the third trimester of pregnancy (28-32 weeks) delivered in Peking University Third Hospital, and Tongzhou Maternal and Child Health Hospital from January 2014 to December 2017 were collected, and 161 cases out of which were measured by CL during both the second trimester and the third trimester of pregnancy. Based on the measured gestational weeks, 427 cases were in the second trimester group and 224 cases in the third trimester group. The predictive value of CL for preterm birth was evaluated by calculating the optimal cut-off point with sensitivity and specificity. Logistic regression analysis was used to assess the relationship between CL and preterm birth after adjusting for confounding factors (age of pregnant women, chorionic status, mulipara, assisted reproductive pregnancy and pre-pregnancy body mass index). Results: (1) The median CL of pregnant women in the second trimester group and the third trimester group were 36 mm (33-40 mm) and 28 mm (18-33 mm) respectively. In the second trimester group, 151 cases (35.4%, 151/427) were preterm birth and 276 cases (64.6%, 276/427) were full-term birth; the median CL of preterm and full-term pregnant women were 34 mm (30-37 mm) and 37 mm (34-40 mm), respectively, with significant difference (P<0.01). In the third trimester group, 100 cases (44.6%, 100/224) were preterm birth and 124 cases (55.4%, 124/224) were full-term birth; the median CL of preterm and full-term pregnant women were 22 mm (15-30 mm) and 31 mm (23-34 mm), respectively, with significant difference (P<0.01). (2) Prediction of preterm birth <32 weeks and <34 weeks was performed with CL in the second trimester group. The area under the receiver-operating characteristics curve were 0.78 (95%CI: 0.70-0.86) and 0.71 (95%CI: 0.64-0.79), respectively. The optimal cut-off points were 36.5 mm and 33.5 mm, respectively. After adjusting for confounding factors, CL was inversely associated with preterm birth <32 weeks and <34 weeks of gestation. (3) Prediction of preterm birth <32 weeks and <34 weeks were performed with CL in the third trimester group. The area under the receiver-operating characteristics curve were 0.86 (0.75-0.96) and 0.75 (0.67-0.84), respectively. The optimal cut-off points were 17.5 mm and 18.5 mm, respectively. After adjusting for confounding factors, CL was inversely associated with preterm birth at <32 weeks and <34 weeks of gestation. Conclusions: CL measured by transvaginal ultrasound in the second and the third trimester is a good predictor for preterm birth of twin pregnancy. CL≤36.5 mm and ≤33.5 mm at 20-24 weeks of gestation could predict preterm birth <32 weeks and <34 weeks respectively. CL≤17.5 mm and ≤18.5 mm at 28-32 weeks of gestation could predict preterm birth <32 weeks and <34 weeks respectively.

[The impact of genetic variation of KDR on clinical outcomes of advanced colorectal cancer patients treated by first line bevacizumab based regimens]

Objective: To investigate the association between kinase insertion region receptor (KDR) gene genetic variation and the efficacy of bevacizumab in patients with advanced colorectal cancer(CRC) were investigated in this study. Methods: 118 patients with advanced colorectal cancer who were treated by bevacizumab based first line regimens were included in this study. Peripheral blood and the biopsy tissue specimens of the CRC patients were collected for the genotyping of genetic variation and KDR gene expression, respectively. The univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, and multivariate were adjusted by Cox regression analysis. Results: Located in the coding region, the prevalence of 889 C>T in KDR among the study population were as follows: CC genotype 86 cases (72.88%), CT genotype 30 cases (25.42%), TT genotype 2 cases (1.70%), minor allele frequency of 889 C>T is 0.14. The distribution of three genotypes in accordance with Hardy-Weinberg Equilibrium (P=0.737). There were no statistical differences in the distribution of the genotypes in baseline clinical data. TT and CT genotype patients were merged in the comparison of clinical outcomes. The clinical outcomes analysis of patients with different genotypes found that the objective response rates (ORR) of CT/TT genotypes were 34.38% and 43.02% (P=0.395), respectively. And the median progression free survival (PFS) of patients with CT/TT genotype and CC genotype were 7.5 and 9.7 months respectively, which was statistically significant (P=0.009). In terms of overall survival (OS), the median OS of the two genotypes were 19.3 and 20.1 (P=0.025), respectively. Adjusted in multivariate Cox regression analysis of PFS, CT/TT genotypes were an independent factor for PFS (OR=1.88, P=0.023). Additionally, of the 57 biopsy tissue specimens, gene expression analysis was conducted. And the results showed that the expression of KDR in cancer tissues of the patients with CT/TT genotypes were significantly higher than those of the CC genotype patients (P<0.001). Conclusion: Among advanced colorectal cancer patients treated by bevacizumab, the polymorphism 889 C>T of KDR may impact the clinical outcomes of bevacizumab first line treatment by influencing the mRNA expression of KDR.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

[Effect of microRNA-106b on the invasion and proliferation of trophoblasts through targeting MMP-2]

Objective: To investigate the expression of microRNA-106b (miR-106b) in the placentas of patients with pre-eclampsia and its relationship with matrix metallopeptidase (MMP) -2, and its effect on the invasion and proliferation of trophoblasts. Methods: (1) Placental tissues were collected from patients with mild pre-eclampsia (mPE, n=30), severe pre-eclampsia (sPE, n=30) and normal pregnant women (n=40). Human choriocarcinoma cell lines JAR and JEG3 were assigned to the miR-106b mimics group, the mimics negative control group, the miR-106b inhibitor group and the inhibitor negative control group, respectively. (2) The target gene of miR-106b(such as MMP-2) was predicted by bioinformatics. Dual-luciferase reporting system was used to verify the regulation of miR-106b on the expression of MMP-2. (3) The expressions of miR-106b and MMP-2 were measured by quantitative real-time PCR (qRT-PCR) and western blot. (4) Cell proliferation was determined by MTT assay. (5) Invasive activities in each group were assessed by cell transwell invasion assays. Results: (1) Predicting result of bioinformatics indicated that MMP-2 was one of the target genes of miR-106b. Dual-luciferase activity assay demonstrated that MMP-2 was the direct target of miR-106b (P<0.01) .(2) The results of qRT-PCR.①The expression of miR-106b in the placentas of mPE, sPE, normal pregnant women were 2.89±0.04, 1.96±0.03, 1.01±0.03, respectively (P<0.05). And the expression of MMP-2 mRNA in the placentas of mPE, sPE, normal pregnant women were 1.87±0.05, 0.69±0.03, 2.78±0.03, respectively (P<0.05). ②The expression of miR-106b in the JAR cell line in the miR-106b mimics group, the mimics negative control group, the miR-106b inhibitor group and the inhibitor negative control group were 2.39±0.03, 1.03±0.04, 0.73±0.03, 1.11±0.04, respectively (P<0.05). And its expression in the JEG3 cell line were 2.17±0.04, 1.18±0.04, 0.61±0.03 and 1.22±0.03, respectively (P<0.05). ③The expression of MMP-2 mRNA in the JAR cell line in the miR-106b mimics group, the mimics negative control group, the miR-106b inhibitor group and the inhibitor negative control group were 0.45±0.15, 1.02±0.03, 2.28±0.03, 1.11±0.03, respectively (P<0.05). And its expression in the JEG3 cell line were 0.58±0.03, 1.25±0.15, 2.25±0.03, 1.21±0.03, respectively (P<0.05). (3) The results of western blot. ①The expression of MMP-2 protein in the placentas of mPE, sPE, normal pregnant women were 1.63±0.04, 0.55±0.03, 2.82±0.03, respectively (P<0.05). ②The expression of MMP-2 protein in the JAR cell line in the miR-106b mimics group, the mimics negative control group, the miR-106b inhibitor group and the inhibitor negative control group were 0.41±0.03, 0.97±0.03, 2.25±0.03, 1.01±0.03, respectively (P<0.05). And its expression in the JEG3 cell line were 0.53±0.03, 1.20±0.03, 2.31±0.04, 1.19±0.03, respectively (P<0.05). (4) miR-106b could inhibit the proliferation of JAR and JEG3 cells, cell proliferation rates in the miR-106b mimics group were lower than that in the mimics negative control group (P<0.05). And cell proliferation rate in the miR-106b inhibitor group was higher than the inhibitor negative control group (P<0.05). (5) The numbers of JAR cell that passed the membrane in the miR-106b mimics group, the mimics negative control group. The miR-106b inhibitor group and the inhibitor negative control group were 61±15, 79±13, 134±13, 80±12, respectively(P<0.05). And the numbers of JEG3 cell that passed were 57±12, 71±15, 128±15, 70±14, respectively (P<0.05). Conclusion: The miR-106b could inhibit the invasion and proliferation of JAR and JEG3 cells through targeting MMP-2, and have a relationship with the pathogenesis of pre-eclampsia.

Evaluation of Natural Food Preservatives in Domestic and Imported Cheese

In milk and milk products, a number of organic acids naturally occur. We investigated the contents of some naturally occurred food preservatives (sorbic acid, benzoic acid, propionic acid, nitrite, and nitrate) contained in domestic and imported cheeses to establish the standard for the allowable range of food preservatives content in cheese. 8 kinds of domestic precheeses (n=104), 16 kinds of domestic cured cheeses (n=204) and 40 kinds of imported cheeses (n=74) were collected. Each domestic cheese was aged for a suitable number of months and stored for 2 mon at 5℃ and 10℃. No preservatives were detected in domestic soft and fresh cheeses, except cream cheese. In case of semi-hard cheeses, 2-5 mg/kg of benzoic acid was detected after 1-2 mon of aging. In imported cheeses, only benzoic acid and propionic acid were detected. The average benzoic acid and propionic acid contents in semi-hard cheese were 8.73 mg/kg and 18.78 mg/kg, respectively. Specifically, 1.16 mg/kg and 6.80 mg/kg of benzoic acid and propionic acid, respectively, were contained in soft cheese, 3.27 mg/kg and 2.84 mg/kg, respectively, in fresh cheese, 1.87 mg/kg and not detected, respectively, in hard cheese, and 2.07 mg/kg and 182.26 mg/kg, respectively, in blended processed cheese.

Expression of KLF5 in odontoblastic differentiation of dental pulp cells during in vitro odontoblastic induction and in vivo dental repair

AIM

To identify whether Krüppel-like factor 5 (KLF5) was involved in odontoblastic differentiation during reparative dentine formation.

METHODOLOGY

Human Dental pulp cells (DPCs) were isolated from healthy human dental pulp tissue and induced for odontoblastic differentiation. Alizarin Red staining, alkaline phosphatase (ALPase) activity, quantitative real-time PCR and Western Blot were performed to evaluate in vitro odontoblastic differentiation. The expression profile of KLF5 during the in vitro odontoblastic differentiation was determined by quantitative real-time PCR and Western Blot. Knock-down of KLF5 by lentivirus-mediated shRNA was performed to determine the function of KLF5 in odontoblastic differentiation. After direct pulp capping with MTA, the maxillary first molar segments dissected from male Wistar rats were prepared for histology analysis and immunohistochemistry staining.

RESULTS

Odontoblastic differentiation was confirmed by significantly increased alkaline phosphatase (ALP; P = 0.004) activity and upregulated odontoblastic differentiation-related genes including dentine sialophosphoprotein (DSPP; P = 0.004) and dentine matrix protein-1 (DMP-1; P = <0.001). The expression of KLF5 was significantly upregulated during odontoblastic differentiation of in vitro cultured DPCs (P = 0.0002). KLF5 knock-down impaired odontoblastic differentiation. After direct pulp capping, dentine bridge-like calcified tissues were formed under the perforation sites. KLF5 was expressed in odontoblast-like cells and DPCs beneath the perforation sites during reparative dentine formation.

CONCLUSIONS

KLF5 might be involved in the process of odontoblastic differentiation during reparative dentine formation.

[Estimation of femoral version based on broach geometry after femoral-neck osteotomy]

OBJECTIVE

To find out whether it is accurate to estimate femoral version based on femoral broach after femoral neck osteotomy using computed tomography scans.

METHODS

In 32 total hip arthroplasty (THA), we performed CT scans before and after operation. Four possible levels (lesser trochanter, 5 mm above, 10 mm above and 15 mm above the lesser trochanter) of broach version were calculated based on the preoperative CT scan. Stem versions were measured on the postoperative CT scan. We determined the difference between the preoperative broach version and the postoperative stem version using the Student's t test for paired samples assuming equal variance.

RESULTS

For the operated hips, preoperative hip version differed according to the level of measurement. Our findings showed that the average femoral version was 37.0°±11.0° at the level of the lesser trochanter (section 1), 34.3°±10.6° at 5 mm above the lesser trochanter (section 2), 28.1°±10.9° at 10 mm above the lesser trochanter (section 3), and 22.4°± 13.7° at 15 mm above the lesser trochanter (section 4), and that the average version for the femoral neck (FNV) was 12.9°±13.8°. The postoperative hip version was the stem version (FSV), which we found to be an average of 26.1°±11.0°. The mean femoral version for section 1 and 2 was larger than the mean postoperative stem version (P<0.01); the mean version for sections 3 and 4 did not differ from the mean postoperative stem version (P>0.05). The mean femoral neck version was less than the mean postoperative stem version (P<0.01); the difference was 13.2°±11.1° of the increased anteversion on average for the FSV compared with FNV.

CONCLUSION

The accuracy of estimated femoral version after arthroplasty depends on broach level. When it is 10 mm above the lesser trochanter, stem version estimation is accurate, but below that level, there is a tendency to overestimate.

FOXM1 and polo-like kinase 1 are co-ordinately overexpressed in patients with gastric adenocarcinomas

BACKGROUND

Gastric cancers present late in life with advanced disease and carry a poor prognosis. Polo-like Kinase 1 (PLK1) is a mitotic kinase with regulatory functions during G2/M and mitosis in the cell cycle. In mammalian cells, there is an intricate co-regulatory relationship between PLK1 and the forkhead transcription factor FOXM1. It has been demonstrated that individually either PLK1 or FOXM1 expression predicts poorer survival. However, the co-expression of both of these markers in gastric adenocarcinomas has not been reported previously.

METHODS

We aimed to assess the expression of PLK1 and FOXM1 in Gastric adenocarcinomas in a Western Population, to examine whether there is a relationship of PLK1 to FOXM1 in cancer samples. We assess both the protein and mRNA expression in this patient population by Tissue Microarray immunohistochemistry and RT-PCR.

RESULTS

Immunohistochemistry was performed on biopsy samples from 79 patients with gastric cancer. Paired normal controls were available in 47 patients. FOXM1 expression was significantly associated with gastric adenocarcinoma (p = 0.001). PLK1 and FOXM1 co-expression was demonstrated in 6/8 (75 %) tumours when analysed by RT-PCR. FOXM1 is overexpressed in a large proportion of gastric carcinomas at the protein level and FOXM1 and PLK1 are concomitantly overexpressed at the mRNA level in this cancer type.

CONCLUSIONS

This study has demonstrated that FOXM1 and its target gene PLK1 are coordinately overexpressed in a proportion of gastric adenocarcinomas. This suggests that chemotherapeutic treatments that target this pathway may be of clinical utility.

TNF-α mutation affects the gene expression profiles of patients with multiple trauma

Multiple trauma can induce sepsis and organ failure, even threaten people’s lives. To further study the mechanisms of multiple trauma, we analyzed microarray of GSE5760. GSE5760 was downloaded from the Gene Expression Omnibus including a total of 58 peripheral blood transcriptome from patients without (WT, n = 30) and carrying (MUT, n = 28) the tumor necrosis factor (TNF) rs1800629 A variant. The differentially expressed genes (DEGs) were screened using the limma package in R and the Benjamin and Hochberg method in a multi-test package. Then, functional enrichment analysis of DEGs was performed. Also, transcription factors significantly related to DEGs were searched using WebGestalt and interaction network of transcription factors and DEGs were constructed using STRING online software. Furthermore, pathway enrichment analysis for the DEGs in the interaction network was conducted using KO-Based Annotation System (KOBAS). We screened 39 DEGs including 27 upregulated and 12 downregulated genes. The enriched functions were associated with biological process (BP) (such as response to hypoxia, P value = 0.039803), cell components (CC) (such as mitochondrial part, P value = 0.043857), and molecular function (MF) (such as structural constituent of ribosome, P value = 0.008735). Besides, RPS7 and RPL17 were associated with ribosome and participated in ribosome pathway. PPP2R2B was related to mitochondrion. KCNMA1, ALAS2 and SOCS3 were associated with hypoxia. Moreover, transcription factors of LEF1, CHX10, ELK1, SP1, and MAZ were significantly related to DEGs. RPS7, RPL17, PPP2R2B, KCNMA1, ALAS2, and SOCS3 might relate to multiple trauma. And TNF-α mutation could cause sepsis in patients with multiple trauma by changing the expression of these genes.

Mixed culture biofilms of Salmonella Typhimurium and cultivable indigenous microorganisms on lettuce show enhanced resistance of their sessile cells to cold oxygen plasma

Control of foodborne pathogens in fresh produce is crucial for food safety, and numerous Salmonella Typhimurium (ST) outbreaks have been reported already. The present study was done to assess effectiveness of cold oxygen plasma (COP) against biofilms of ST mixed with cultivable indigenous microorganisms (CIM). ST and CIM were grown at 15 °C as monocultures and mixed cultures for planktonic state, biofilm on stainless steel, and lettuce leaves. Thereafter, the samples were treated with COP and surviving populations were counted using plate counting methods. Biofilms and stomatal colonization were examined using field emission scanning electron microscopy (FESEM) and food quality was assessed after treatment. Mixed cultures of ST and CIM showed an antagonistic interaction on lettuce but not on SS or in planktonic state. Mixed cultures showed significantly (p < 0.05) greater resistance to COP compared to monoculture biofilms on lettuce but not on SS or planktonic state. Shift from smooth to rugose colony type was found for planktonic and for biofilms on SS but not on lettuce for ST. Mixed culture biofilms colonized stomata on the inside as demonstrated by FESEM. Although, lettuce quality was not affected by COP, this technology has to be optimized for further development of the successful inactivation of complex multispecies biofilm structures presented by real food environment.

HIV and aging: insights from the Asia Pacific HIV Observational Database (APHOD)

OBJECTIVES

The proportion of people living with HIV/AIDS in the ageing population (>50 years old) is increasing. We aimed to explore the relationship between older age and treatment outcomes in HIV-positive persons from the Asia Pacific region.

METHODS

Patients from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD) were included in the analysis. We used survival methods to assess the association between older age and all-cause mortality, as well as time to treatment modification. We used regression analyses to evaluate changes in CD4 counts after combination antiretroviral therapy (cART) initiation and determined the odds of detectable viral load, up to 24 months of treatment.

RESULTS

A total of 7142 patients were included in these analyses (60% in TAHOD and 40% in AHOD), of whom 25% were >50 years old. In multivariable analyses, those aged > 50 years were at least twice as likely to die as those aged 30-39 years [hazard ratio (HR) for 50-59 years: 2.27; 95% confidence interval (CI) 1.34-3.83; HR for > 60 years: 4.28; 95% CI 2.42-7.55]. The effect of older age on CD4 count changes was insignificant (p-trend=0.06). The odds of detectable viral load after cART initiation decreased with age (p-trend=< 0.0001). The effect of older age on time to first treatment modification was insignificant (p-trend=0.21). We found no statistically significant differences in outcomes between AHOD and TAHOD participants for all endpoints examined.

CONCLUSIONS

The associations between older age and typical patient outcomes in HIV-positive patients from the Asia Pacific region are similar in AHOD and TAHOD. Our data indicate that 'age effects' traverse the resource-rich and resource-limited divide and that future ageing-related findings might be applicable to each setting.

Evaluation of the removal and destruction effect of a chlorine and thiamine dilaurylsulfate combined treatment on L. monocytogenes biofilm

The present study investigated the efficacy of single and combined treatment of both chlorine and thiamine dilaurylsulfate (TDS) on the reduction of Listeria monocytogenes biofilms in microtiter plate. The disinfectants used in this study were 50, 100, and 200 mg/L chlorine and 100, 500, and 1000 mg/L of TDS. Biofilm-forming index (BFI) and culturable cell count were used to evaluate the disinfectant assay. The highest BFI reduction was 0.80, achieved by the combination of 200 mg/L chlorine and 1000 mg/L TDS. In contrast, the highest culturable cell count reduction was 4.80 log colony-forming units/well by the combination of 200 mg/L chlorine and 100 mg/L TDS. The BFI was reduced in a concentration-dependent manner while culturable cell count was significantly reduced only when all chlorine concentration was combined with 100 mg/L TDS. However, when chlorine was combined with a higher concentration of TDS, the reduction decreased significantly. The result in this study showed that the combination of the 200 mg/L chlorine and 1000 mg/L TDS could be a practical application in removing L. monocytogenes biofilms from surfaces in food industry, and for the 200 mg/L chlorine and 100 mg/L, it can be used for killing the pathogen biofilms. However, more studies are still needed in order to show its efficacy on foods surfaces as well as to develop an even more effective treatment in both killing and removing biofilms.

Analysis of key genes and pathways involved in acute lung injury in a mouse model

A mouse model of acute lung injury (ALI) was chosen in this study to explore the key genes and pathways involved in the process of ALI with microarray technology. Gene expression microarray data were downloaded from the Gene Expression Omnibus database. Mice from the experimental group were further divided into 6 subgroups, which received octadecenoate treatments for 1, 1.5, 3, 4, 18, and 24 h. Differentially co-expressed genes were screened to uncover the pathogenesis of ALI. Almost all of the differentially co-expressed genes were identified at two times: 1.5 and 3 h. Functional analysis revealed that several inflammation-related pathways were significantly enriched. Ubiquitin-mediated proteolysis, hematopoietic cell lineage, and leukocyte transendothelial migration were enriched at 1.5 h. The B cell receptor signaling pathway, T cell receptor signaling pathway, natural killer cell-mediated cytotoxicity, Fc epsilon RI signaling pathway, and ubiquitin-mediated proteolysis were significantly enriched at 3 h. It could be inferred that ALI initiated at 1.5 h and lasted through 3 h. However, co-expression patterns were not found from 4 h onward. In conclusion, several key genes and pathways implicated in the development of ALI were found in this study using the mouse model, among which ubiquitin-mediated proteolysis appears to play an important role in the process.

IMM-H004, a novel coumarin derivative compound, protects against amyloid beta-induced neurotoxicity through a mitochondrial-dependent pathway

We have investigated the effect of IMM-H004 (7-hydroxy-5-methoxy-4-methyl-3-(4-methylpiperazin-1-yl)-2H-chromen-2-one), a coumarin derivative, on the amyloid beta (Aβ)-induced neurotoxicity in primary culture cortical neurons and pheochromocytoma (PC12) cells. Our results showed that treatment with IMM-H004 markedly reduced the number of apoptotic cells after exposure to Aβ25-35 or Aβ1-42, determined by MTT, TUNEL staining and Flow cytometry. Further study indicated that IMM-H004 significantly inhibited Aβ-induced cytotoxicity and apoptosis by reversing Aβ-induced mitochondrial dysfunction, including MMP (mitochondrial membrane potential) decrease, reactive oxygen species production, and mitochondrial release of cytochrome c. IMM-H004 can regulate the interaction between Bax and Bcl-2, decreased levels of p53 and active caspase-3 protein induced by Aβ25-35. Furthermore, IMM-H004 also reduced translocation of AIF (apoptosis-inducing factor) induced by Aβ25-35. These results demonstrated that IMM-H004 was capable of protecting neuronal cells from Aβ-induced degeneration through a mitochondrial-dependent apoptotic pathway. The results of this study lend further credence to the notion that IMM-H004 is a 'multipotent therapeutic agrent' that reduces toxic levels of brain Aβ, and holds the potential to protect neuronal mitochondrial function in Alzheimer's disease.

The FOXM1-PLK1 axis is commonly upregulated in oesophageal adenocarcinoma

BACKGROUND

The transcription factor FOXM1 is an important regulator of the cell cycle through controlling periodic gene expression during the G2 and M phases. One key target for FOXM1 is the gene encoding the protein kinase PLK1 and PLK1 itself acts in a positive feedback loop to phosphorylate and activate FOXM1. Both FOXM1 and PLK1 have been shown to be overexpressed in a variety of different tumour types.

METHODS

We have used a combination of RT-PCR, western blotting, tissue microarrays and metadata analysis of microarray data to study whether the FOXM1-PLK1 regulatory axis is upregulated and operational in oesophageal adenocarcinoma.

RESULTS

FOXM1 and PLK1 are expressed in oesophageal adenocarcinoma-derived cell lines and demonstrate cross-regulatory interactions. Importantly, we also demonstrate the concomitant overexpression of FOXM1 and PLK1 in a large proportion of oesophageal adenocarcinoma samples. This co-association was extended to the additional FOXM1 target genes CCNB1, AURKB and CKS1. In a cohort of patients who subsequently underwent surgery, the expression of several FOXM1 target genes was prognostic for overall survival.

CONCLUSIONS

FOXM1 and its target gene PLK1 are commonly overexpressed in oesophageal adenocarcinomas and this association can be extended to other FOXM1 target genes, providing potentially important biomarkers for predicting post-surgery disease survival.

FP3: a novel VEGF blocker with antiangiogenic effects in vitro and antitumour effects in vivo

BACKGROUND Vascular endothelial growth factor (VEGF) is a critical promoter of blood vessel growth during embryonic development and neovascularisation in tumours. VEGF serves as a logical target for antiangiogenic cancer therapy because of its fundamental role in tumour angiogenesis. This study is to investigate the inhibitory effects of FP3, a novel VEGF blocker, on angiogenesis in vitro and tumour growth in vivo. METHODS The inhibitory effects of FP3 on angiogenesis in vitro were evaluated by using human umbilical vein endothelial cells (HUVECs) and rat aortic ring. The inhibitory effects of FP3 on tumour growth and angiogenesis in vivo were evaluated in a human non-small-cell lung cancer (NSCLC) cell line A549 tumour xenograft model with the methods of tumour growth regression assay and immunohistochemical staining, respectively. RESULTS In experiments with HUVECs, FP3 inhibited cell proliferation and migration. In rat aortic ring assay, FP3 suppressed VEGF-induced vessel sprouting. In tumour growth regression assay, FP3 significantly blocked the growth of A549 tumour in the subcutaneous tumour xenograft model and dramatically decreased the vessel density of tumour. CONCLUSIONS FP3 has excellent inhibitory effects on tumour angiogenesis both in vitro and in vivo, therefore it could be used as an effective antiangiogenic agent.

Spinal bombesin-recognized neurones mediate more nonhistaminergic than histaminergic sensation of itch in mice

BACKGROUND

There may be distinct pathways for transmission of histaminergic and nonhistaminergic itch, but all scratching behaviours elicited by histamine-dependent and histamine-independent pruritogens are diminished when spinal bombesin-recognized neurones are ablated.

AIM

To investigate whether there is a difference in transmission of spinal itch signals between histamine-induced itch and nonhistamine-induced itch after neurotoxic destruction of spinal bombesin-recognized neurones.

METHODS

To ascertain the different relevance of spinal bombesin-recognized neurones in transmission of itch signals between these two classes of pruritogens, we determined the distribution of Fos-positive cells in the dorsal horn of spinal cord after stimulation with histamine (500 μg/site) and chloroquine (200 μg/site) in mice with spinal bombesin-recognized neurones ablated by intrathecal injection of bombesin-saporin (400 ng/5 μL).

RESULTS

We found that after stimulation with both histamine and chloroquine, fewer Fos-positive cells were present in mice treated with bombesin-saporin compared with those treated with saporin alone. The reduction in Fos expression was greater with chloroquine than with histamine, and the distribution of Fos-positive cells was also different. We used biotin-labelled isolectin (IB)4, which labels one subset of C-fibres, and found that the percentages of Fos-positive cells in three areas (the dorsal to IB4-labelled region, the IB4-labelled region itself, and the ventral to IB4-labelled region) all changed significantly after intradermal injection of chloroquine, but not histamine, in mice treated with bombesin-saporin.

CONCLUSIONS

These results suggest that spinal bombesin-recognized neurones are critical to both the histamine-dependent and histamine-independent pathways for itch, and that they mediate more nonhistaminergic than histaminergic sensation of itch in mice.

Genetic diversity analyses of class 1 integrons and their associated antimicrobial resistance genes in Enterobacteriaceae strains recovered from aquatic habitats in China

AIMS

To characterize the molecular diversity of class 1 integrons and antibiotic resistance (AR) genes of Enterobacteriaceae strains recovered from aquatic habitats in Jinan, Shandong Province, China.

METHODS AND RESULTS

Six hundred and thirty-eight antimicrobial-resistant Enterobacteriaceae isolated from wastewater were examined for class 1 integron. Of these, 293 were positive for the class 1 integrase gene intI1; among these, 34 gene cassettes and 29 AR genes were detected. Twenty-nine distinct gene cassette arrays were identified by restriction fragment length polymorphism (RFLP). Seven strains harboring novel gene cassette arrays were subjected to further study, in which antimicrobial susceptibility profiles were determined, and the presence of other AR genes outside of the integrons was assayed. Several of the resistance determinants were found to be transferable by conjugation or transformation.

CONCLUSIONS

This study established the assessment of class 1 integron and antimicrobial resistance gene patterns among environmental Enterobacteriaceae. Also, a restriction enzyme EcoRII was employed to develop a rapid and simple method for characterizing gene cassette arrays by RFLP analysis, which facilitated further study of novel gene cassette arrays.

SIGNIFICANCE AND IMPACT OF STUDY

These data not only illustrated the diversity of class 1 integron gene cassettes but also provided direct evidence that integrons mobilized gene cassettes, generating new linkages of resistance genes, and they could be integrated in gene transfer units such as conjugative plasmids to contribute to the dissemination of AR genes by horizontal gene transfer (HGT) in aquatic environments.

Identification of amino acids critical for IgE-binding to sequential epitopes of bovine kappa-casein and the similarity of these epitopes to the corresponding human kappa-casein sequence

BACKGROUND

The delineation of allergenic (i.e. IgE-binding) epitopes in cow's milk proteins and the amino acids (AAs) critical for IgE-binding is necessary to understand better the structural properties of an allergen and to develop more efficacious immunotherapeutic reagents. Furthermore, this information may enable us to understand better cross-sensitivity between different allergens.

METHODS

Eleven peptides, 10-14 AAs in length, representing the IgE-binding epitopes of kappa-casein were synthesized on a derivatized cellulose membrane with single AA substitutions at each position. Membranes were incubated with pooled sera from 15 milk-allergic patients and individual sera from 10 of the patients included in the pool.

RESULTS

For 10/11 allergenic peptides, one to five different single AA substitutions resulted in elimination of IgE-binding of pooled patient sera. Overall at least one mutated peptide could be found for these 10 IgE-binding sites that resulted in a reduction of IgE-binding in at least 80% of the patients who recognized the native protein. Furthermore, the IgE-binding region at AA104-112 on bovine kappa-casein showed a high degree of similarity with the human kappa-casein, respectively, including the AAs critical for IgE-binding.

CONCLUSION

This finding suggests that critical AAs should be assessed with both pooled and individual patient sera to account for the B-cell epitope heterogeneity between patients, with cow's milk allergy. In addition, we identified two potentially cross-reactive peptides between bovine and human caseins of unknown clinical relevance.

Mutational analysis of immunoglobulin E-binding epitopes of ?-casein and ?-lactoglobulin showed a heterogeneous pattern of critical amino acids between individual patients and pooled sera

BACKGROUND

For immunotherapeutic approaches, 'critical' amino acids (AAs) within allergenic epitopes are replaced with alternate AAs to eliminate IgE antibody binding.

OBJECTIVE

To determine the critical AAs for IgE binding in beta-casein and beta-lactoglobulin (BLG).

METHODS

Peptides of 10-14 AAs in length were synthesized on a derivatized cellulose membrane with single AA substitutions (alanine or glycine) at each position. Membranes were incubated with a pool of sera from 15 cow's milk-allergic patients and individual sera from six of the 15 patients. In cases where no decrease in binding occurred with a single AA substitution, peptides with two AA substitutions were generated and labelled.

RESULTS

Using pooled patient sera, single AA substitutions led to complete elimination of binding to six of 11 peptides for beta-casein and to all six peptides for BLG. Substituting two AAs led to an elimination of binding to four of the remaining five beta-casein epitopes. However, in three of the 11 modified beta-casein peptides and five of the six BLG peptides, no decrease in IgE binding occurred in at least one individual patient. For these patients, critical AAs other than those defined by the patient serum pool were identified, indicating a heterogeneous pattern of IgE recognition.

CONCLUSION

These results indicate that AAs critical for IgE binding are more heterogeneous than initially defined by pooled milk-allergic patient sera. For future immunotherapeutic interventions with mutated peptides, critical AAs should also be identified with individual patient sera to account for heterogeneity of IgE binding between patients.

Observations on ozone treatment of excess sludge

This work experimentally studied the effects of ozonation treatment on waste sludge. During the treatment process, various parameters characterizing sludge were investigated. A substantial reduction in the volume of sludge and the release of intracellular and extracellular materials were observed. With the increase of ozone dose, the settleability and water content of sludge improved obviously, but the filterability of sludge deteriorated drastically. In addition, the evolution of particle size was evaluated, which proved the breakup of sludge flocs and cells. There existed a threshold of ozone dose which was 0.04 gO(3)/gMLSS in this work. Above the threshold, the soluble chemical oxygen demand (SCOD), protein, carbohydrate, total nitrogen and total phosphorus in supernatant increased remarkably and the electron transport system (ETS) sludge activity decreased. Organic nitrogen and organic phosphorus occupied the main part of total nitrogen and total phosphorus in the supernatant.

Enhanced angiogenesis characteristic of SPARC-null mice disappears with age

The impairment of angiogenesis in aging has been attributed, in part, to alterations in proteins associated with the extracellular matrix (ECM). SPARC (secreted protein acidic and rich in cysteine/osteonectin/BM-40) is a matricellular protein that regulates endothelial cell function as well as cell-ECM interactions. We have previously shown that angiogenesis, as reflected by fibrovascular invasion into subcutaneously implanted polyvinyl alcohol (PVA) sponges, is increased in SPARC-null mice (6-9 months of age) relative to their wild-type (WT) counterparts. In this study, we define the influence of aging on (a) the expression of SPARC and (b) fibrovascular invasion into sponge implants in SPARC-null and WT mice. The expression of SPARC in fibroblasts and endothelial cells derived from young donors (humans mean age less than 30 years and mice 4-6 months of age) and old donors (humans mean age over 65 years and mice 22-27 months of age) decreased 1.6 to 2.3-fold with age. Analysis of fibrovascular invasion into sponges implanted into old (22-27 months) SPARC-null and WT mice showed no differences in percent area of invasion or collagenous ECM. Moreover, sponges from old SPARC-null and WT mice contained similar levels of VEGF that were significantly lower than those from young (4-6 months) mice. In contrast to fibroblasts from young SPARC-null mice, dermal fibroblasts from old SPARC-null mice did not migrate farther, proliferate faster, or produce greater amounts of VEGF relative to their old WT counterparts. However, when stimulated with TGF-beta1, primary cells isolated from the sponge implants, and dermal fibroblasts from both old SPARC-null and WT mice, showed marked increases in VEGF secretion. These data indicate that aging results in a loss of enhanced angiogenesis in SPARC-null mice, as a result of the detrimental impact of age on cellular functions, collagen deposition, and VEGF synthesis. However, the influence of aging on these processes may be reversed, in part, by growth factor stimulation.

[Purification and biological activity of rh-leptin expressed in Escherichia coli]

The human leptin was successfully expressed with high level in E. coli under the control of PL promotor. The yield of recombinant protein was over 40% of total cellular protein and expressed as inclusion bodies. The recombinant human leptin (rh-leptin) was purified with gel filtration, anion-exchange and reverse chromatography. Refolding was achieved by gradually reducing denaturant using a diafiltration method. The refolded rh-leptin was characterized by SDS-PAGE, Western-blotting and its first 15 amino acid residues sequence of the N-terminal. The purified product was found to be biologically active, reducing the food intake and body weight gain upon testing in BALB/c mice.

Structure-activity relationships of a series of pyrrolo[3,2-d]pyrimidine derivatives and related compounds as neuropeptide Y5 receptor antagonists

Neuropeptide Y (NPY) has been shown to play an important role in the regulation of food intake and energy balance. Pharmacological data suggests that the Y5 receptor subtype contributes to the effects of NPY on appetite, and therefore a Y5 antagonist might be a useful therapeutic agent for the treatment of obesity. In attempts to identify potential Y5 antagonists, a series of pyrrolo[3, 2-d]pyrimidine derivatives was prepared and evaluated for their ability to bind to Y5 receptors in vitro. We report here the synthesis and initial structure-activity relationship investigations for this class of compounds. The target compounds were prepared by a variety of synthetic routes designed to modify both the substitution and the heterocyclic core of the pyrrolo[3,2-d]pyrimidine lead 1. In addition to identifying several potent Y5 antagonists for evaluation as potential antiobesity agents, a pharmacophore model for the human Y5 receptor is presented.