豺针毛的扫描电镜观察分析

应用扫描电镜技术对豺Cuon alpinus Pallas头部、背部、前肢、后肢、腹部和尾部针毛的表面超微结构进行了观察和比较研究.结果表明:豺的6种针毛均近似为梭形;6种针毛的3个典型部位之间在鳞片类型、鳞片排列方式、高度和密度差异及游离缘平滑度上均具有较高的相似性和一致性.6种针毛的近根部鳞片为瓣状型;主体部分鳞片为杂波型;近梢部鳞片为冠状型.这将为豺的形态学研究及物种鉴定提供一定的生物学基础资料.     

Tilapia (Oreochromis mossambicus) antimicrobial peptide, hepcidin 1-5, shows antitumor activity in cancer cells

The inhibitory function of tilapia hepcidin (TH)1-5, an antimicrobial peptide, was not examined in previous studies. In this study, we synthesized the TH1-5 peptide and tested TH1-5's antitumor activity against several tumor cell lines. We show that TH1-5 inhibited the proliferation of tumor cells and reduced colony formation in a soft agar assay. Scanning electron microscopy and transmission electron microscopy showed that TH1-5 altered the membrane structure similar to the function of a lytic peptide. Acridine orange/ethidium bromide staining, a wound-healing assay, and a flow cytometric analysis showed that TH1-5 induced necrosis with high-concentration treatment and induced apoptosis with low-concentration treatment. Inflammation is known to be closely associated with the development of cancer. TH1-5 showing anti-inflammatory effects in a previous publication induced us to evaluate the anti-inflammatory effects in cancer cell lines through the expressions of immune-related genes after being treated with the TH1-5 peptide. However, real-time qualitative RT-PCR indicated that TH1-5 treatment induced downregulation of the expressions of interleukin (IL)-6, IL-8, IL-12, IL-15, interferon-γ, CTSG, caspase-7, and Bcl-2, and upregulation of IL-2 and CAPN5 in HeLa cells, and upregulation of IL-8 and CTSG in HT1080 cells. These results suggest that TH1-5 possibly induces an inflammatory response in HeLa cells, but not in HT1080 cells. Overall, these results indicate that TH1-5 possesses the potential to be a novel peptide for cancer therapy.     

Cloning and expression of the α-amylase gene and oxytetracycline production in Streptomyces rimosus

An 8.4 kb Sau3AI DNA fragment containing the Streptomyces rimosus TM-55 -amylase gene (amy) was ligated to a vector pIJ702, named pCYL01, and cloned into amylase deficient mutant S. lividans M2 (amy ^–). Subcloning study showed that the amy gene was localized in 3.3 kbKpnI-PstI fragment. The molecular weight of the purified -amylases of S. lividans M2/pCYL01 and S. rimosus TM-55 were estimated to be 65.7 kDa. Different sizes of recombinant plasmids carrying the amy gene had been retransferred into the parental strain of S. rimosus TM-55. Among these S. rimosus transformants, TM-55/pCYL01, TM-55/pCYL12 and TM-55/pCYL36 showed amylase activity 1.36- to 2.05-fold at the seventh day (1.61 to 2.42 units vs 1.18 units), and oxytetracycline (OTC) production 2.00- to 2.50-fold at the ninth day (approximate 140 to 170 g ml^–1 vs 72 g ml^–1), higher than that of S. rimosus TM-55 alone, respectively. These results showed that industrial microorganisms could be improved by genetic and metabolic engineering.     

Immunostimulatory flagellin from Burkholderia pseudomallei effects on an increase in the intracellular calcium concentration and up-regulation of TNF-alpha by mononuclear cells

Using flow cytometry analysis, the flagellin of Burkholderia pseudomallei acts as a signalling inducer, and evokes an increase in the intracellular calcium ion concentration ([Ca(2+)]i) in human peripheral blood mononuclear cells (PBMC). The cells with increased [Ca(2+)]i segregate into the live monocyte gate and not into the live lymphocyte gates. The stimulated [Ca(2+)]i increase can be neutralized with anti-flagellin antibodies. In the absence of [Ca(2+)], [Ca(2+)]i was increased rapidly in flagellin-treated cells compared to non-flagellin-treated cells only after the addition of 1 mM CaCl(2). Selective calcium antagonists were used to effectively block the [Ca(2+)]i signal, revealing that this signal was decreased by the addition of L-type calcium channel blockers (diltiazem, nifedipine and verapamil) and La(2+) but was not changed by the addition of a T-type calcium channel blocker (flunarizine). It seemed that flagellin facilitates [Ca(2+)]i influx via a La(2+) sensitive L-type cellular membrane channel. Furthermore, flagellin also acts as a TNF-alpha inducer in a time- and concentration-dependent manner when adhered mononuclear cells are treated with flagellin. This ability to induce TNF-alpha production was affected by the presence of [Ca(2+)] in the culture medium. It suggested that B. pseudomallei flagellin is an immuno-stimulatory molecule, causing an increase in [Ca(2+)]i and an up-regulation of TNF-alpha, which may play an important role in the inflammation process.     

三种鼠针毛表面超微结构的比较研究

利用扫描电镜技术对棕背(鼠平)Clethrionomys rufocanus、大林姬鼠Apodemus sylvatics和花鼠Eutaraias sibiricus 3种森林害鼠针毛的表面结构进行观察.研究结果认为:3种鼠针毛在鳞片类型、游离缘平滑度、高度、密度等因素上存在一定的差异,其中棕背(鼠平)和大林姬鼠差异不显著,而花鼠与其它两种鼠差异显著,在鼠的分类上具有一定的参考意义.     

α-Mangostin induces mitochondrial dependent apoptosis in human hepatoma SK-Hep-1 cells through inhibition of p38 MAPK pathway

α-Mangostin is a dietary xanthone that has been shown to have anti-cancer and anti-proliferative properties in various types of human cancer cells. This study investigates the molecular mechanism of the apoptosis-inducing effects of α-mangostin on human hepatocellular carcinoma (HCC) cells. We observed that α-mangostin reduces the viability of HCC cells in a dose- and time-dependent manner. α-Mangostin mediated apoptosis of SK-Hep-1 cells is accompanied by nuclear chromatin condensation and cell cycle arrest in the sub-G1 phases as well as phosphatidylserine exposure. Furthermore, α-mangostin triggered the mitochondrial caspase apoptotic pathway, as indicated by the loss of mitochondrial membrane potential, the release of cytochrome c from mitochondria, and the regulation of B cell lymphoma 2 family member expression. Moreover, α-mangostin inhibited a sustained activation of p38 mitogen-activated protein kinase (MAPK) phosphorylation, and treatment with a p38 MAPK inhibitor enhanced α-mangostin-induced caspase activation and apoptosis in SK-Hep-1 cells. In vivo xenograft mice experiments revealed that α-mangostin significantly reduced tumor growth and weight in mice inoculated with SK-Hep-1 cells. These findings demonstrate that α-mangostin induces mitochondria-mediated apoptosis through inactivation of the p38 MAPK signaling pathway and that α-mangostin inhibits the in vivo tumor growth of SK-Hep-1 xenograft mice.     

Analysis of MUC6 polymorphisms on the clinicopathologic characteristics of Asian patients with oral squamous cell carcinoma

Head and neck squamous cell carcinomas (HNSCCs) are generally associated with tobacco consumption, alcohol abuse or both. Mucins (MUCs) are high-molecular-weight glycoproteins produced by many epithelial tissues. Many studies have indicated that MUCs play an important role in cancer metastasis. MUC6 expression has been observed in gastric and oncocytic phenotypes and plays an important role during cancer progression. We found that levels of MUC6 are lower in Asian HNCC patients and affect the disease-free survival of HNCC patients. Next, we investigated the combined effect of MUC6 polymorphisms and exposure to environmental carcinogens on the susceptibility to and clinicopathological characteristics of HNCC. Three single-nucleotide polymorphisms (SNPs) of MUC6 (rs7481521, rs6597947 and rs61869016) were analysed using real-time PCR. After adjusting for other co-variants, we found that carrying a CC genotype at MUC6 rs6597947 led to a lower risk of developing oral squamous cell carcinoma (OSCC) than wild-type carriers among non-betel-quid chewers. Moreover, male oral cancer patients who carried the AA + CC genotype at MUC6 rs6597947 had a lower risk of lymph node metastasis than other genotypes, suggesting a significant functional compromise and decompensated disease. Therefore, our findings suggest that genetic variations in MUC6 may correlate to OSCC and indicate the progression in OSCC patients.     

Use of porous alginate sponges for substantial chondrocyte expansion and matrix production: effects of seeding density

Autologous cell transplantation is a promising approach for cartilage repair, but the expansion of chondrocytes in a monolayer, a common approach to amplifying the cell number, inevitably leads to cell de-differentiation. To explore whether porous alginate sponges could be utilized for chondrocyte expansion and investigate the effects of seeding densities, the porcine chondrocytes were seeded to porous alginate sponges at low (5 x 10(5) cells per 40 sponges), medium (5 x 10(6) cells per 40 sponges), or high (2 x 10(7) cells per 40 sponges) density. After 4-week perfusion culture, all three groups resulted in chondrocyte proliferation, maintenance of chondrocytic gene (collagen II, Sox 9 and aggrecan) expression, and formation of cell clusters resembling cartilaginous tissues. The higher the seeding density, the higher the final cell density and GAGs production and, accordingly, the larger the cell clusters. Strikingly, the cumulative expansion ratios achieved by the low-density group ( approximately 150-fold) significantly exceeded those achieved by the medium (approximately 21-fold) and high (approximately 4.7-fold) density groups, as well as those achieved using other scaffolds. In conclusion, seeding chondrocytes to the alginate sponges at a low density, combined with perfusion culture, represents a drastic improvement in expanding autologous chondrocytes.     

Dietary Administration of Scallion Extract Effectively Inhibits Colorectal Tumor Growth: Cellular and Molecular Mechanisms in Mice

Colorectal cancer is a common malignancy and a leading cause of cancer death worldwide. Diet is known to play an important role in the etiology of colon cancer and dietary chemoprevention is receiving increasing attention for prevention and/or alternative treatment of colon cancers. Allium fistulosum L., commonly known as scallion, is popularly used as a spice or vegetable worldwide, and as a traditional medicine in Asian cultures for treating a variety of diseases. In this study we evaluated the possible beneficial effects of dietary scallion on chemoprevention of colon cancer using a mouse model of colon carcinoma (CT-26 cells subcutaneously inoculated into BALB/c mice). Tumor lysates were subjected to western blotting for analysis of key inflammatory markers, ELISA for analysis of cytokines, and immunohistochemistry for analysis of inflammatory markers. Metabolite profiles of scallion extracts were analyzed by LC-MS/MS. Scallion extracts, particularly hot-water extract, orally fed to mice at 50 mg (dry weight)/kg body weight resulted in significant suppression of tumor growth and enhanced the survival rate of test mice. At the molecular level, scallion extracts inhibited the key inflammatory markers COX-2 and iNOS, and suppressed the expression of various cellular markers known to be involved in tumor apoptosis (apoptosis index), proliferation (cyclin D1 and c-Myc), angiogenesis (VEGF and HIF-1α), and tumor invasion (MMP-9 and ICAM-1) when compared with vehicle control-treated mice. Our findings may warrant further investigation of the use of common scallion as a chemopreventive dietary agent to lower the risk of colon cancer.     

For Our founding father of ABRC, Prof. Ray Wu (1928–2008)

Dr. Ray Wu, the Liberty Hyde Bailey Professor of Mo-lecular Biology and Genetics at Cornell University, passed away on Sunday, February 10, 2008, at the age of 79. Dr. Wu was a pioneer in DNA sequencing and recombinant DNA technology, a renowned scientist in rice genetic engi-neering, a strong and long time advocate for scientific re-search and education in Chinese Taipei and Chinese Mainland, and most of all, a genuine mentor and true friend to many of us, worldwide and at ABRC.