The effect of different platelet-rich plasma concentrations on proliferation and differentiation of human periodontal ligament cells in vitro

OBJECTIVES: The use of platelets and platelet products has become increasingly popular clinically as a means of accelerating endosseous wound healing. It is likely that growth factors released by activated platelets at the site of injury play a role in periodontal regeneration by regulating cellular activity. The purpose of this study was to evaluate the biological effects of platelet-rich plasma (PRP) on human periodontal ligament cells (hPDLCs) in vitro. MATERIALS AND METHODS: Primary cultures of hPDLCs were obtained from healthy premolars. PRP was isolated by two-step centrifugation. Two main growth factors present in the thrombin-activated PRP (platelet-derived growth factor [PDGF-AB] and transforming growth factor-beta1 [TGF-beta1]) were evaluated using ELISA assay. Activated PRP or the combination of recombined human TGF-beta1 (rhTGF-beta1) and PDGF-AB (rhPDGF-AB) were added to hPDLCs in different concentrations to assess cell proliferation and osteogenic differentiation. RESULTS: PRP contained high levels of TGF-beta1 and PDGF-AB. Cell attachment, proliferation and ALP activity were enhanced by addition of PRP or rhTGF-beta1 and rhPDGF-AB combination to the cell cultures, while the stimulatory potency of PRP was much greater than the latter. These stimulatory effects presented in a dose-dependant manner, it seemed that PRP with 50~100 ng/ml TGF-beta1 was an ideal concentration. CONCLUSIONS: PRP can enhance hPDLC adhesion, proliferation and induce the differentiation of hPDLC into mineralized tissue formation cell; thereby contribute to the main processes of periodontal tissue regeneration. For economical and biological reasons, PRP has more clinical beneficial than analogous growth factors.     

A novel 62‐bp indel mutation in the promoter region of transforming growth factor‐beta 2 (TGFB2) gene is associated with body weight in chickens

Transforming growth factor‐beta 2 (encoded by TGFB2) is a growth factor that regulates a plethora of cellular functions. In this study, we sequenced the promoter and full‐length exon region of the chicken TGFB2 and found two mutations (g.‐640C>T and g.‐851_‐790del) within the promoter. The two polymorphisms were genotyped in 1030 pedigreed hens recorded for body weight at 7 (BW7), 9 (BW9), 11 (BW11), 13 (BW13), 17 (BW17) weeks old, egg weight at 36 weeks of age (EW36) and egg numbers from the age at first egg (AFE) to 40 weeks of age (EN40). Despite the fact that no mutations were found to have statistically significant genetic effects on egg production, the association results of growth traits showed that both g.‐640C>T and g.‐851_‐790del had significant effects on body weights and that both genotype g.‐640TT and g.‐851_‐790wt/wt were positive for body weight performance. Therefore, the polymorphisms of TGFB2, especially the g.‐851_‐790del mutation associated with body weight at almost all periods, could be potential useful genetic markers to improve the growth of Beijing You chickens.     

Lysine-Specific Demethylase 1 in Breast Cancer Cells Contributes to the Production of Endogenous Formaldehyde in the Metastatic Bone Cancer Pain Model of Rats

Background

Bone cancer pain seriously affects the quality of life of cancer patients. Our previous study found that endogenous formaldehyde was produced by cancer cells metastasized into bone marrows and played an important role in bone cancer pain. However, the mechanism of production of this endogenous formaldehyde by metastatic cancer cells was unknown in bone cancer pain rats. Lysine-specific demethylase 1 (LSD1) is one of the major enzymes catalyzing the production of formaldehyde. The expression of LSD1 and the concentration of formaldehyde were up-regulated in many high-risk tumors.

Objective

This study aimed to investigate whether LSD1 in metastasized MRMT-1 breast cancer cells in bone marrows participated in the production of endogenous formaldehyde in bone cancer pain rats.

Methodology/Principal Findings

Concentration of the endogenous formaldehyde was measured by high performance liquid chromatography (HPLC). Endogenous formaldehyde dramatically increased in cultured MRMT-1 breast cancer cells in vitro, in bone marrows and sera of bone cancer pain rats, in tumor tissues and sera of MRMT-1 subcutaneous vaccination model rats in vivo. Formaldehyde at a concentration as low as the above measured (3 mM) induced pain behaviors in normal rats. The expression of LSD1 which mainly located in nuclei of cancer cells significantly increased in bone marrows of bone cancer pain rats from 14 d to 21 d after inoculation. Furthermore, inhibition of LSD1 decreased the production of formaldehyde in MRMT-1 cells in vitro. Intraperitoneal injection of LSD1 inhibitor pargyline from 3 d to 14 d after inoculation of MRMT-1 cancer cells reduced bone cancer pain behaviors.

Conclusion

Our data in the present study, combing our previous report, suggested that in the endogenous formaldehyde-induced pain in bone cancer pain rats, LSD1 in metastasized cancer cells contributed to the production of the endogenous formaldehyde.     

Research progress on the immune mechanism of the silkworm Bombyx mori

The silkworm Bombyx mori L., representing an important economic insect and one of the best models for studying insect immunity, possesses an efficient and sophisticated innate immune system against invasive microorganisms. The innate immune system basically includes humoural immunity and cellular immunity. The humoural immunity, which functions via molecules including humoural factors, lysozymes, phenoloxidase, hemolin, lectins and, in particular, antimicrobial peptides, plays a central role in eliminating the invading pathogens. The cellular immunity is primarily carried out and mediated by plasmatocytes and granular cells of haemocytes in the haemolymph, usually followed by melanization. Additionally, apoptosis, a primary viral defence for insects lacking adaptive immunity, comprises an important part of the silkworm immune system. Currently, there is still the lack of a comprehensive and systematic understanding of the molecular mechanisms of silkworm immunity. We review the latest research progress on silkworm immune mechanisms, including phenoloxidase‐dependent melanization and apoptosis, which is conducive to improving our understanding of the silkworm immune mechanism, clarifying the relationship of various immune mechanisms, and also providing a theoretical basis and reference for the future research of insect immunity.     

Rice OsRAD21-2 is Expressed in Actively Dividing Tissues and its Ectopic Expression in Yeast Results in Aberrant Cell Division and Growth

Rad21 and its meiotic counterpart Rec8,the key components of the cohesin complex,are essential for sister chromatid cohesion and chromosome segregation in mitosis and meiosis,respectively.In contrast to yeast and vertebrates,which have only two RAD21/REC8 genes,the rice genome encodes four Rad21/Rec8 proteins.Here,we report on the cloning and characterization of OsRAD21-2 from rice(Oryza sativa L.).Phylogenetic analysis of the full-length amino acids showed that OsRad21-2 was grouped into the plant-specific...     

利用体细胞核移植技术制作人胰岛素原转基因牛 （英文）

通过体细胞核移植技术制作了人胰岛素原转基因牛。在CMV启动子指导下以内部核糖体进入位点序列(IRES)连接的新霉素抗性基因和绿色荧光蛋白基因组成了双重标记基因的筛选系统,用于转基因细胞的富集以及细胞和植入前胚胎的筛选。转基因通过电穿孔的方法(900V/cm,5ms)转入体外培养的牛胎儿成纤维细胞,基因转染细胞在添加G418 (800μg/mL)的培养基中培养10天以富集转基因细胞。选择表达绿色荧光蛋白的转基因细胞作为核供体进行体细胞核移植,重构胚经体外培养至囊胚阶段,选择表达绿色荧光蛋白的囊胚进行胚胎移植。为比较基因转染以及供体细胞所处周期对转基因细胞核移植胚胎发育的影响,用作核移植供体的转基因细胞或非转基因细胞先饥饿培养2—4天(0.5 ?S) ,然后恢复培养(10?S) 10 h使细胞同步化于G1期,以正常培养的细胞作为对照进行核移植。结果表明,转基因细胞作为核供体得到的核移植胚胎的体外囊胚发育率低于以非转基因细胞为核供体的对照组(23.2% VS 35.2 %,P<0.05) ;转基因细胞周期同步化处理与否对其克隆胚囊胚发育率无显著影响(23.2% VS 18.9 %,P>0.05)。胚胎移植后2个月直肠检查发现7头受体牛(每头移植2—4枚胚胎)中有一头妊娠,并最终发育足月产下一头小牛。聚合酶链反应(PCR)检测和DNA测序分析表明其为转人胰岛素原基因的转基因克隆牛。     

FragGeneScan: predicting genes in short and error-prone reads

The advances of next-generation sequencing technology have facilitated metagenomics research that attempts to determine directly the whole collection of genetic material within an environmental sample (i.e. the metagenome). Identification of genes directly from short reads has become an important yet challenging problem in annotating metagenomes, since the assembly of metagenomes is often not available. Gene predictors developed for whole genomes (e.g. Glimmer) and recently developed for metagenomic sequences (e.g. MetaGene) show a significant decrease in performance as the sequencing error rates increase, or as reads get shorter. We have developed a novel gene prediction method FragGeneScan, which combines sequencing error models and codon usages in a hidden Markov model to improve the prediction of protein-coding region in short reads. The performance of FragGeneScan was comparable to Glimmer and MetaGene for complete genomes. But for short reads, FragGeneScan consistently outperformed MetaGene (accuracy improved ∼62% for reads of 400 bases with 1% sequencing errors, and ∼18% for short reads of 100 bases that are error free). When applied to metagenomes, FragGeneScan recovered substantially more genes than MetaGene predicted (>90% of the genes identified by homology search), and many novel genes with no homologs in current protein sequence database.     

Solution structure of human SUMO-3 C47S and its binding surface for Ubc9

Small ubiquitin-related modifier SUMO-3 is a member of a growing family of ubiquitin-like proteins (Ubls). So far, four isoforms of SUMO have been identified in humans. It is generally known that SUMO modification regulates protein localization and activity. Previous structure and function studies have been mainly focused on SUMO-1. The sequence of SUMO-3 is 46% identical with that of SUMO-1; nevertheless, functional heterogeneity has been found between the two homologues. Here we report the solution structure of SUMO-3 C47S (residues 14-92) featuring the beta-beta-alpha-beta-beta-alpha-beta ubiquitin fold. Structural comparison shows that SUMO-3 C47S resembles ubiquitin more than SUMO-1. On the helix-sheet interface, a strong hydrophobic interaction contributes to formation of the globular and compact fold. A Gly-Gly motif at the C-terminal tail, extending away from the core structure, is accessible to enzymes and substrates. In vivo, SUMO modification proceeds via a multistep pathway, and Ubc9 plays an indispensable role as the SUMO conjugating enzyme (E2) in this process. To develop a better understanding of SUMO-3 conjugation, the Ubc9 binding surface on SUMO-3 C47S has been detected by chemical shift perturbation using NMR spectroscopy. The binding site mainly resides on the hydrophilic side of the beta-sheet. Negatively charged and hydrophobic residues of this region are highly or moderately conserved among SUMO family members. Notably, the negatively charged surface of SUMO-3 C47S is highly complementary in its electrostatic potentials and hydrophobicity to the positively charged surface of Ubc9. This work indicates dissimilarities between SUMO-3 and SUMO-1 in tertiary structure and provides insight into the specific interactions of SUMO-3 with its modifying enzyme.