食品镉离子污染免疫检测技术的研究与应用

传统的理化分析方法在食品Cd2+污染检测方面发挥了重要的作用,但均存在一定的缺陷,急需建立快速、高效的检测方法.食品Cd2+污染免疫检测是一种新型的分析方法,与理化分析方法相比,具有省时省力、费用低廉、便于携带、操作简便等优点,已成为重要的检测手段.详细综述了目前国内外在食品Cd2+污染免疫检测方面的研究方法和成果,主要包括Cd2+人工抗原的制备与鉴定、Cd2+单克隆抗体的制备及免疫学特性影响因素分析和Cd2+免疫检测方法的建立及应用.在总结这些研究的基础上,展望了食品Cd2+污染免疫检测技术的发展方向.     

Prediction of peptidase category based on functional domain composition

Peptidases play pivotal regulatory roles in conception, birth, digestion, growth, maturation, aging, and death of all organisms. These regulatory roles include activation, synthesis and turnover of proteins. In the proteomics era, computational methods to identify peptidases and catalog the peptidases into six different major classes-aspartic peptidases, cysteine peptidases, glutamic peptidases, metallo peptidases, serine peptidases and threonine peptidases can give an instant glance at the biological functions of a newly identified protein. In this contribution, by combining the nearest neighbor algorithm and the functional domain composition, we introduce both an automatic peptidase identifier and an automatic peptidase classier. The successful identification and classification rates are 93.7% and 96.5% for our peptidase identifier and peptidase classifier, respectively. Free online peptidase identifier and peptidase classifier are provided on our Web page http://pcal.biosino.org/protease_classification.html.     

Target enrichment sequencing of 307 germplasm accessions identified ancestry of ancient and modern hybrids and signatures of adaptation and selection in sugarcane (Saccharum spp.), a ‘sweet’ crop with ‘bitter’ genomes

Sugarcane (Saccharum spp.) is a highly energy‐efficient crop primarily for sugar and bio‐ethanol production. Sugarcane genetics and cultivar improvement have been extremely challenging largely due to its complex genomes with high polyploidy levels. In this study, we deeply sequenced the coding regions of 307 sugarcane germplasm accessions. Nearly five million sequence variations were catalogued. The average of 98× sequence depth enabled different allele dosages of sequence variation to be differentiated in this polyploid collection. With selected high‐quality genome‐wide SNPs, we performed population genomic studies and environmental association analysis. Results illustrated that the ancient sugarcane hybrids, S. barberi and S. sinense, and modern sugarcane hybrids are significantly different in terms of genomic compositions, hybridization processes and their potential ancestry contributors. Linkage disequilibrium (LD) analysis showed a large extent of LD in sugarcane, with 962.4 Kbp, 2739.2 Kbp and 3573.6 Kbp for S. spontaneum, S. officinarum and modern S. hybrids respectively. Candidate selective sweep regions and genes were identified during domestication and historical selection processes of sugarcane in addition to genes associated with environmental variables at the original locations of the collection. This research provided an extensive amount of genomic resources for sugarcane community and the in‐depth population genomic analyses shed light on the breeding and evolution history of sugarcane, a highly polyploid species.     

REV3L,a Promising Target in Regulating the Chemosensitivity of Cervical Cancer Cells

REV3L, the catalytic subunit of DNA Polymerase ζ (Polζ), plays a significant role in the DNA damage tolerance mechanism of translesion synthesis (TLS). The role of REV3L in chemosensitivity of cervical cancer needs exploration. In the present study, we evaluated the expression of the Polζ protein in paraffin-embedded tissues using immunohistochemistry and found that the expression of Polζ in cervical cancer tissues was higher than that in normal tissues. We then established some cervical cancer cell lines with REV3L suppression or overexpression. Depletion of REV3L suppresses cell proliferation and colony formation of cervical cancer cells through G₁ arrest, and REV3L promotes cell proliferation and colony formation of cervical cancer cells by promoting G₁ phase to S phase transition. The suppression of REV3L expression enhanced the sensitivity of cervical cancer cells to cisplatin, and the overexpression of REV3L conferred resistance to cisplatin as evidenced by the alteration of apoptosis rates, and significantly expression level changes of anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2), myeloid cell leukemia sequence 1 (Mcl-1) and B-cell lymphoma-extra large (Bcl-xl) and proapoptotic Bcl-2-associated x protein (Bax). Our data suggest that REV3L plays an important role in regulating cervical cancer cellular response to cisplatin, and thus targeting REV3L may be a promising way to alter chemosensitivity in cervical cancer patients.     

福建省南平茫荡山木本植物区系研究

福建省南平茫荡山有木本植物102科,272属,719种,隶属于13个分布区类型,占我国分布区类型的86.7%,具有区系成分复杂、种类繁多、起源古老和珍稀树种丰富的特点。     

融合酶的设计和应用研究进展

酶的分子改造和重新设计是解决酶催化工业应用瓶颈的重要途径。基于融合蛋白设计的融合酶技术是分子酶工程的一个研究热点,已逐渐应用于多功能酶和酶靠近效应的构建与控制研究中,显示出重要的理论和应用研究价值。文中对近年来融合酶的分子设计策略和应用研究的进展进行了综述。首先介绍了融合酶的概念和特点,并对最近研究中出现的融合酶构建策略进行了归纳总结,重点阐述了不同种类连接肽对融合酶的影响及其可能机理。同时,对目前融合酶的应用研究进行了归纳和讨论。最后,结合本实验室的研究,指出了融合酶领域的关键问题并对其发展方向进行了探讨和展望。     

Establishing a cGMP pancreatic islet processing facility: the first experience in Iran

It has been predicted that one of the greatest increase in prevalence of diabetes will happen in the Middle East bear in the next decades. The aim of standard therapeutic strategies for diabetes is better control of complications. In contrast, some new strategies like cell and gene therapy have aimed to cure the disease. In recent years, significant progress has occurred in beta-cell replacement therapies with a progressive improvement of short-term and long term outcomes. In year 2005, considering the impact of the disease in Iran and the promising results of the Edmonton protocol, the funding for establishing a current Good Manufacturing Practice (cGMP) islet processing facility by Endocrinology and Metabolism Research Center was approved by Tehran University of Medical Sciences. Several islet isolations were performed following establishment of cGMP facility and recruitment of all required equipments for process validation and experimental purpose. Finally the first successful clinical islet isolation and transplantation was performed in September 2010. In spite of a high cost of the procedure it is considered beneficial and may prevent long term complications and the costs associated with secondary cares. In this article we will briefly describe our experience in setting up a cGMP islet processing facility which can provide valuable information for regional countries interested to establish similar facilities.     

Stable knockdown of MYCN by lentivirus-based RNAi inhibits human neuroblastoma cells growth in vitro and in vivo

Neuroblastoma is the most common childhood solid tumor, yet current treatment approaches have not been able to effectively control this cancer. Amplification and overexpression of MYCN have been shown to be closely related with high risk and poor prognosis in neuroblastoma. This suggests that MYCN is an important target for the antitumor therapy. Recently, vector-based RNA interference (RNAi) systems have been successfully used to eliminate gene expression, but knockdown of MYCN by vector-based RNAi as a therapeutic model for neuroblastoma has not been fully established.In this study, we used a lentivirus vector-based RNAi approach which expresses short hairpin RNA (shRNA) to knockdown MYCN in neuroblastoma cell lines IMR-32 and LAN-1. Western blotting analysis showed that expressions of MYCN were efficiently downregulated after infection with MYCN shRNA expression vector. The stable suppression of MYCN expression induced differentiation and apoptosis in neuroblastoma cell lines. Furthermore, we demonstrated that these changes were associated with caspase-3 activation, p27 upregulation as well as Bcl-2 and MDM2 downregulation. Finally, we demonstrated that downregulation of MYCN expression significantly reduced colony formation in vitro and tumor growth in nude mice.Our data indicate that lentivirus vector-mediated silencing of MYCN in neuroblastoma cells could efficiently and significantly inhibit tumor growth both in vitro and in vivo. Therefore we demonstrate the therapeutic potential of lentivirus-delivered shRNA as a novel approach for treatment of neuroblastoma and other malignant tumors with MYCN overexpression.