苔藓植物孢子形态的研究(一)——几种泥炭藓(Sphagnum)孢子的光学研究和电子显微镜观察

泥炭藓(Sphagnum)是水湿或沼泽地区丛生藓类。其植物体形态和构造分化简单,孢子体仅具由配子体组织发育的假蒴柄;孢蒴球形,盖裂,无蒴轴及蒴齿分化,因而为鲜纲中一个独立的亚纲,在苔藓系统排列中,列为原始的类型之一。     

FBXW11 contributes to stem-cell-like features and liver metastasis through regulating HIC1-mediated SIRT1 transcription in colorectal cancer

Colorectal tumorigenesis is a heterogeneous disease driven by multiple genetic and epigenetic alterations. F-box and WD repeat domain containing 11 (FBXW11) is a member of the F-box protein family that regulates the ubiquitination of key factors associated with tumor growth and aggressiveness. Our study aimed to explore the role of FBXW11 in the development and metastasis of colorectal cancer (CRC). FBXW11 was overexpressed in colorectal tumor tissues and its overexpression was associated with a poor prognosis of CRC patients. The upregulation of FBXW11 not only promoted cell proliferation, invasion, and migration, but also contributed to maintaining stem-cell features in colorectal tumor cells. Further analysis revealed that FBXW11 targeted hypermethylated in cancer 1 (HIC1) and reduced its stability in CRC cells through ubiquitination. Moreover, the expression of sirtuin 1 (SIRT1), a deacetylase in tumor cells was upregulated by FBXW11 via regulating HIC1 expression. The mouse xenograft models of CRC confirmed that FBXW11 knockdown impeded colorectal tumor growth and liver metastasis in vivo. In summary, our study identified FBXW11 as an oncogenic factor that contributed to stem-cell-like properties and liver metastasis in CRC via regulating HIC1-mediated SIRT1 expression. These results provide a rationale for the development of FBXW11-targeting drugs for CRC patients.Subject terms: Cancer, Endocrine system and metabolic diseases     

云南姜科植物的增补与修订

据中国植物志(1981),云南有姜科植物17属, 78种,9变种。其后多篇文章论及一些种属,标本也有较多的增加。本文根据现有的标本与文献资料对云南姜科植物作增补与修订,共涉及16属15种,包括1个新种,7个修定后的异名。云南共计有姜科植物18属,148种和11变种。     

The Relationship between the Effects of Cytokinin on the Expension and Metabolism of Excised Cucumber Cotyledons and Water Stress

Excised cucumber (Cucumis sativus, var. Jin-ian No. 4) cotyledons were incubated with 10 ppm of BA (benzyladenine) or water for 1 h, then thouroughly rinsed with water and grown in darkness on filter paper saturated with different concentrations of mannitol solution. Up to 24 h, the fresh weight, carotenoid, RNA, DNA and lipid contents of cotyledons were determined. Although mannitol solution reduced the effectiveness of BA treatment, in the same condition of osmotic potential, the increases of fresh weight, carotenoid, RNA and DNA contents, as well as the decrease of lipid per cotyledon were always much higher in BA treated tissues. BA enhanced the rate of water uptake by the cotyledons. The fresh weight of BA and 0.2 M mannitol treated cotyledons was equal to that of water control, but the increases of carotenoid and nucleic acid contents and the decrease of lipid were much higher in tho former than the latter. 0.3 M and 0.5 M mannitol solu- tions almost interrupted the water uptake of water and BA treated cotyledons respectively. However, the increases of carotenoid and nucleic acid contents as well as decrease of lipid were still occurred in these conditions. The different osmotic potential did nearly not affect the ratio of the increases of carotenoid and nucleic acid contents between BA treatment and control. It means the effectiveness of BA was almost the same under different osmotic potential It is evident that BA stimulated simultaneously the water uptake and metabolism of the cotyledons. They are probably different processes but closely related to each other.     

The Effects of Cytokinins on Unfolding of Cotyledons and Opening of Hypocotylar Hooks of Cucumber

Benzyladenine (BA), zeatin and kinetin caused the unfolding of cucumber (Cucumis sativus L. Var. Jing-ye No. 4) cotyledons. But the other plant hormones e.g. gibberellic acid (GA3), indoleacetic acid(IAA), ethylene (ethrel), abscisic acid (ABA) and other related compound e.g. KCl, adenine were not so. This response was caused by even lower concentration (0.01 ppm). Therefore, it could be used as a bioassay for cytokinins. KCl affaeted synergistically on cytokinin-induced unfolding. Basally applied BA (10 ppm) stimulated the opening of the intact hypocotylar hook. The light affacted synergistically on BA-induced opening. However, basally applied BA prevented the opening of decapitated hooks, especially in the light. The cotyledons were found to play a part of effects in maintaining the hook.     

Isoenzyme Patterns of Root and Shoot in the Early Growth of Wheat

Isoenzyme patterns of peroxidase, catalase, glucose-6-phosephate, glutamate and isocitrate dehydrogenases, esterase, amylase and IAA oxidase in the embryos, endosperms, roots and shoots of wheat seedlings (Triticum aestivum L. var. Nung-da 139) were determined by horizontal starch gel electrophoresis and polyacrylamide gel disc electrophoresis respectively. The number of isoenzymes of peroxidasc and amylase was increased with the concomitant increase of days during germination. The isoenzyme bands of esterase, glutamate, glucose-6-phosphate and isocitrate dehydrogenases in the embryos were more in the begining of germination. The activities of pero- xidase, IAA oxidase and glutamate dehydrogenase in roots were higher than those in shoots. On the contrary, the activities of catalase and glucose-6-phosphate dehydrogenase in shoots were higher than those in roots. However the activity of esterasc was slight higher in shoots. There was no difference in the activity of isocitrate dehydrogenase between roots and shoots. The morphological difference of shoot and root is evidently related to isoenzyme patterns. This investigation indicates that different metabolic characters are existed in shoot and root during differentiation.     

Diet-induced obesity accelerates oral carcinogenesis by recruitment and functional enhancement of myeloid-derived suppressor cells

Although obesity has been associated with an increased risk and aggressiveness of many types of carcinoma, whether it promotes squamous cell carcinoma remains unclear. To reveal the role of obesity in oral squamous cell carcinoma (OSCC) initiation and development, we used 4NQO-induced OSCC model mice to examine the impact of dietary obesity on carcinogenesis. The results showed that high-fat diet (HFD)-induced obesity significantly promoted the incidence of OSCC and altered the local immune microenvironment with the expansion of CD11b⁺Gr1⁺ myeloid-derived suppressor cells (MDSCs). The underlying mechanism that induced an immunosuppressive local microenvironment in obesity was the recruitment of MDSCs through the CCL9/CCR1 axis and enhancement of MDSC immunosuppressive function via intracellular fatty acid uptake. Furthermore, clinical samples verified the increase in infiltrated CD33⁺ (a marker of human MDSCs) cells in obese OSCC patients, and data from the TCGA dataset confirmed that CD33 expression was positively correlated with local adipocytes in OSCC. Survival analysis showed that enrichment of adipocytes and high expression of CD33 were associated with poor prognosis in OSCC patients. Strikingly, depletion of MDSCs significantly ameliorated HFD-promoted carcinogenesis in 4NQO-induced model mice. These findings indicate that obesity is also an important risk factor for OSCC, and cancer immunotherapy, especially targeting MDSCs, may exhibit greater antitumor efficacy in obese patients.Subject terms: Cancer microenvironment, Oral cancer     

浙江无核柿炭疽病菌鉴定及附着胞形成过程中的核相变化

浙江无核柿炭疽病近年来在浙江淳安地区严重发生,根据形态学特征病原菌鉴定为胶孢炭疽菌ColletotrichumgloeosporioidesPenz.,在枝条病斑上的分生孢子盘通常不产生刚毛,分生孢子顶端顶部钝圆,基部平截,分生孢子盘中的孢子包埋在基质中,紧密结合在一起。分生孢子在自然寄主和人工培养条件下形态特征相似。6个柿树炭疽菌菌株的rDNAITS序列联配显示,其序列是相同的。用UPGMA方法分析ITS1-ITS2序列构建的炭疽菌系统发育树把6个柿树炭疽菌菌株和其它寄主上的胶孢炭疽菌或其有性型围小丛壳菌菌系分入同一个组,与根据形态学的鉴定结果一致。在附着胞形成过程中,用DAPI荧光染色观察到核相发生两次有丝分裂变化。第一次有丝分裂发生在分生孢子固着聚苯乙烯塑料培养皿3-4h后,随后,分生孢子中部形成一个隔膜,把它分成两个细胞;6~7h后,分生孢子发生第二次有丝分裂。分裂后,一个核通过芽管移入附着胞中。     

Biochemical properties of a high fidelity DNA ligase from Thermus species AK16D.

NAD+-dependent DNA ligases from thermophilic bacteria Thermus species are highly homologous with amino acid sequence identities ranging from 85 to 98%. Thermus species AK16D ligase, the most divergent of the seven Thermus isolates collected worldwide, was cloned, expressed in Escherichia coli and purified to homogeneity. This Thermus ligase is similar to Thermus thermophilus HB8 ligase with respect to pH, salt, NAD+, divalent cation profiles and steady-state kinetics.However, the former is more discriminative toward T/G mismatches at the 3'-side of the ligation junction, as judged by the ratios of initial ligation rates of matched and mismatched substrates. The two wild-type Thermus ligases and a Tth ligase mutant (K294R) demonstrate 1-2 orders of magnitude higher fidelity than viral T4 DNA ligase. Both Thermus ligases are active with either the metal cofactor Mg2+, Mn2+or Ca2+but not with Co2+, Ni2+, Cu2+or Zn2+. While the nick closure step with Ca2+becomes rate-limiting which results in the accumulation of DNA-adenylate intermediate, Ni2+only supports intermediate formation to a limited extent. Both Thermus ligases exhibit enhanced mismatch ligation when Mn2+is substituted for Mg2+, but the Tsp. AK16D ligase remains more specific toward perfectly matched substrate.     

刺五加多糖研究进展

刺五加多糖(Acanthopanax senticosus polysacharide ASPS)是从五加科植物刺五加(Aaanthopanax senticosus(Rupr.et Mxia)Harns)的根、根皮及果中提取分离的多糖.它是刺五加中除甙类外的另一类活性成分.报报道,刺五加中含有2%～6%碱溶性多糖及2.3%～5.7%水溶性多糖.本文就刺五加多糖的化学及药理学研究做一综述.