基于NGS方法评估不同保存条件对粪便样本中菌群含量的影响

目的 评估粪便样本的不同保存条件对肠道微生态研究结果的影响.方法 设计相关实验,比较7种不同的保存方法,基于高通量测序技术比对不同时间、不同贮存温度对粪便样本DNA质量、菌群多样性及病原菌检出等结果之间的差异.结果 证实了对于粪便样本采集仍建议采取即刻提取核酸或-20℃保存的方法.同时比较多种保存方法后发现,采用不同样...     

胡萝卜DcPAB基因的分离及其结构与功能分析

运用改进的减法杂交技术分离到胡萝卜Poly(A)结合蛋白基因DcPAB .其cDNA编码区长度为 1 977bp ,编码 6 5 8个氨基酸和 1个终止密码子 .基因组转录序列区长度为 4 6 1 6bp ,包含 9个外显子和 8个内含子 .DcPAB在胡萝卜基因组中为单拷贝基因 .该基因在胡萝卜体细胞胚中特异性表达 ,且其表达活性在调控 解调控前后有明显差异 .体外结合实验表明 ,在大肠杆菌中表达并纯化的DcPAB蛋白具有与oligo(A) 2 0 特异性结合的性能 .酵母突变体互补实验进一步证明 ,该基因可以互补PAB基因缺失的酵母突变体的功能缺陷     

青蒿素及其衍生物抗肿瘤的研究进展

青蒿素类药物是治疗疟疾的主要药物,其衍生物有青蒿琥酯、蒿甲醚和二氢青蒿素等.近年来研究发现,青蒿素及其衍生物具有明显的抗肿瘤作用.研究表明:青蒿素及其衍生物可以抑制或杀伤肿瘤细胞;抑制肿瘤细胞增殖与诱导肿瘤细胞凋亡;抑制血管生成;选择性杀伤肿瘤细胞;逆转肿瘤细胞的多重耐药;具有放射增敏效应.因青蒿素及其衍生物安全低毒,有望成为新型的广泛、高效、低毒的抗癌药物.     

Effect of zearalenone treatment on the production of wheat haploids via the maize pollination system

The ability of zearalenone (ZEN) to stimulate the growth of haploid wheat embryos formed following the pollination of wheat spikes with maize pollen was tested. The maize pollination system was used as a model to compare the activity of ZEN with that of auxin analogues. Three solutions, each with a different concentration of ZEN (6.0, 3.0 or 1.5 microM), and a solution of 2,4-dichlorophenoxyacetic acid (control) were tested for their effect on ovary swelling, frequency of embryo formation and the ability to regenerate plants. In total, 3,105 florets of 282 spikes from five different cultivars of hexaploid winter wheat ( Triticum aestivum L.) were pollinated with maize ( Zea mays L. cv. Gama) pollen and treated with the ZEN solutions. The highest concentration of ZEN (6.0 microM) was the most effective in inducing ovary swelling (84 swollen ovaries/100 pollinated florets) and increasing the frequency of embryo induction (18.9 embryos/100 pollinated florets), but these embryos were severely deformed. They had low capability to germinate in vitro, while callus was easily formed and indirect regeneration of plants was possible. The lowest ZEN concentration (1.5 micrroM) induced ovary swelling in 42.8/100 pollinated florets and embryo growth in 3.3 out of 100 pollinated florets. The embryos were regular in shape, and almost half of them germinated in vitro while callus induction from them failed. The concentration of 3 microM ZEN had an intermediate effect. The type of response of the various wheat genotypes was similar, while frequencies were different, with cv. Izolda being the most responsive. The results show that ZEN has some of the properties of an auxin analogue, while other effects of its action are unique. It can be used in the maize pollination system of doubled haploid production to replace auxin analogues when indirect regeneration of plants via callus tissue is planned.     

Bmi‐1 plays a critical role in protection from renal tubulointerstitial injury by maintaining redox balance

To determine whether Bmi-1 deficiency could lead to renal tubulointerstitial injury by mitochondrial dysfunction and increased oxidative stress in the kidney, 3-week-old Bmi-1^-/- mice were treated with the antioxidant N-acetylcysteine (NAC, 1 mg mL⁻¹) in their drinking water, or pyrro-quinoline quinone (PQQ, 4 mg kg⁻¹ diet) in their diet for 2 weeks, and their renal phenotypes were compared with vehicle-treated Bmi1^-/- and wild-type mice. Bmi-1 was knocked down in human renal proximal tubular epithelial (HK2) cells which were treated with 1 mm NAC for 72 or 96 h, and their phenotypes were compared with control cells. Five-week-old vehicle-treated Bmi-1^-/- mice displayed renal interstitial fibrosis, tubular atrophy, and severe renal function impairment with decreased renal cell proliferation, increased renal cell apoptosis and senescence, and inflammatory cell infiltration. Impaired mitochondrial structure, decreased mitochondrial numbers, and increased oxidative stress occurred in Bmi-1^-/- mice; subsequently, this caused DNA damage, the activation of TGF-β1/Smad signaling, and the imbalance between extracellular matrix synthesis and degradation. Oxidative stress-induced epithelial-to-mesenchymal transition of renal tubular epithelial cells was enhanced in Bmi-1 knocked down HK2 cells. All phenotypic alterations caused by Bmi-1 deficiency were ameliorated by antioxidant treatment. These findings indicate that Bmi-1 plays a critical role in protection from renal tubulointerstitial injury by maintaining redox balance and will be a novel therapeutic target for preventing renal tubulointerstitial injury.     

Histone deacetylase inhibitor valproic acid sensitizes B16F10 melanoma cells to cucurbitacin B treatment

Cucurbitacin B (CuB) is reported to have anti-proliferation effects on a variety of tumors including melanoma, and more effective regimens by combination of this agent with others are under investigation. In this study, the anti-melanoma effect of CuB as a single agent and in combination with valproic acid (VPA), an inhibitor of histone deacetylase (HDAC), was evaluated in B16F10, a mouse melanoma cell line. The results demonstrated that CuB inhibited the proliferation of the cell line in a dose-dependent manner. However, it was likely that a pro-survival compensatory response, involving the induction of autophagy and upregulation of anti-apoptotic Bcl-2 protein, was induced by CuB treatment, which might greatly decrease the cytotoxicity of this agent. Supporting this, the melanoma cells were found to be more sensitive to the combination of CuB with chloroquine, a well-known autophagy inhibitor. And CuB-induced autophagy was associated with c-Jun N-terminal kinase (JNK) activation, at least partly, since inhibition of JNK activity by SP600125 could alleviate the autophagy. When CuB was combined with VPA, the two drugs showed synergistic cytotoxicity by induction of cell apoptosis. Moreover, the multiploidization effect of CuB was also suppressed in the presence of VPA. In contrast to the transient activation of JNKs by CuB, the combination of CuB and VPA resulted in prolonged JNK activation, although at low level after 4 h. Our results demonstrated that HDAC inhibitor VPA can sensitize B16F10 cells to CuB treatment through induction of apoptotic pathway.     

Advanced Electrolytes for Fast‐Charging High‐Voltage Lithium‐Ion Batteries in Wide‐Temperature Range

LiNi_xMn_yCo_1?x?yO₂ (NMC) cathode materials with Ni ≥ 0.8 have attracted great interest for high energy‐density lithium‐ion batteries (LIBs) but their practical applications under high charge voltages (e.g., 4.4 V and above) still face significant challenges due to severe capacity fading by the unstable cathode/electrolyte interface. Here, an advanced electrolyte is developed that has a high oxidation potential over 4.9 V and enables NMC811‐based LIBs to achieve excellent cycling stability in 2.5–4.4 V at room temperature and 60 °C, good rate capabilities under fast charging and discharging up to 3C rate (1C = 2.8 mA cm^?2), and superior low‐temperature discharge performance down to ?30 °C with a capacity retention of 85.6% at C/5 rate. It is also demonstrated that the electrode/electrolyte interfaces, not the electrolyte conductivity and viscosity, govern the LIB performance. This work sheds light on a very promising strategy to develop new electrolytes for fast‐charging high‐energy LIBs in a wide‐temperature range.     

LDHA induces EMT gene transcription and regulates autophagy to promote the metastasis and tumorigenesis of papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is one of the most common kinds of endocrine-related cancer and has a heterogeneous prognosis. Metabolic reprogramming is one of the hallmarks of cancers. Aberrant glucose metabolism is associated with malignant biological behavior. However, the functions and mechanisms of glucose metabolism genes in PTC are not fully understood. Thus, data from The Cancer Genome Atlas database were analyzed, and lactate dehydrogenase A (LDHA) was determined to be a potential novel diagnostic and therapeutic target for PTCs. The research objective was to investigate the expression of LDHA in PTCs and to explore the main functions and relative mechanisms of LDHA in PTCs. Higher expression levels of LDHA were found in PTC tissues than in normal thyroid tissues at both the mRNA and protein levels. Higher expression levels of LDHA were correlated with aggressive clinicopathological features and poor prognosis. Moreover, we found that LDHA not only promoted PTC migration and invasion but also enhanced tumor growth both in vitro and in vivo. In addition, we revealed that the metabolic products of LDHA catalyzed induced the epithelial–mesenchymal transition process by increasing the relative gene H3K27 acetylation. Moreover, LDHA knockdown activated the AMPK pathway and induced protective autophagy. An autophagy inhibitor significantly enhanced the antitumor effect of FX11. These results suggested that LDHA enhanced the cell metastasis and proliferation of PTCs and may therefore become a potential therapeutic target for PTCs.Subject terms: Thyroid cancer, Target validation