雷公藤提取物中主要物质基础及其抗肿瘤活性研究北大核心CSCD

为进一步阐明雷公藤中的主要物质基础,并评价其抗肿瘤活性。该研究采用柱层析、HPLC等技术,对雷公藤提取物进行研究。结果表明:(1)从雷公藤95%乙醇提取物中分离得到12个化合物,根据理化性质及波谱数据鉴定各化合物的结构分别为α,β-amyrenone(1)、3β-acetoxyolean-12-en-28-oic acid(2)、antriptolactone(3)、ω-hydroxypropioquaiacone(4)、3-(4-hydroxy-3-methoxyphenyl)-propenal(5)、3-methoxy-4-hydroxy phenylethanol(6)、vanillin(7)、3,4,5-三甲氧基苯酚(8)、对羟基苯甲酸(9)、对羟基苯甲醛(10)、vanillyl alcohol(11)、2,6-dimethxy-1,4-benzoquinone(12)。其中,化合物1、2、5、12为首次在该属植物中分离得到。(2)采用噻唑蓝(MTT)法对12个化合物进行抗SH-SY5Y细胞株、K562细胞株和Hel细胞株3种肿瘤细胞系细胞增殖活性的筛选,并对活性较好的化合物12进行Hoechst荧光染色和促凋亡作用的检测发现,化合物2、3、5、12具有一定的抗肿瘤活性,其中化合物12的抗肿瘤活性最为显著(SH-SY5Y细胞、Hel细胞、K562细胞的IC_(50)值分别为35.6、14.3、28.8μmol·L^(-1))。该研究结果进一步丰富了雷公藤的化学成分,发现了1个具有明显抗肿瘤活性的单体物质,为雷公藤的进一步开发提供了科学依据。     

Selection for novel metabolic capabilities in Salmonella enterica

Bacteria are known to display extensive metabolic diversity and many studies have shown that they can use an extensive repertoire of small molecules as carbon‐ and energy sources. However, it is less clear to what extent a bacterium can expand its existing metabolic capabilities by acquiring mutations that, for example, rewire its metabolic pathways. To investigate this capability and potential for evolution of novel phenotypes, we sampled large populations of mutagenized Salmonella enterica to select very rare mutants that can grow on minimal media containing 124 low molecular weight compounds as sole carbon sources. We found mutants growing on 18 of these novel carbon sources, and identified the causal mutations that allowed growth for four of them. Mutations that relieve physiological constraints or increase expression of existing pathways were found to be important contributors to the novel phenotypes. For the remaining 14 novel phenotypes, whole genome sequencing of independent mutants and genetic analysis suggested that these novel metabolic phenotypes result from a combination of multiple mutations. This work, by virtue of identifying the genetic and mechanistic basis for new metabolic capabilities, sheds light on the properties of adaptive landscapes underlying the evolution of novel phenotypes.     

Temporal variation in abundance of male and female spruce budworms at combinatory associations of light traps and pheromone traps

A 3‐year study (2014–2016) was conducted at Rocky Harbour near the west coast of Newfoundland, Canada, to record the abundance and phenology of adult spruce budworms captured at traps, using a factorial design (light traps and pheromone traps deployed contiguously or segregated spatially). Budworms were most abundant and occurred seasonally earlier in 2014 than in 2015 and 2016; these findings held generally true for males and females. The geographic setting of Newfoundland (large island isolated from the mainland by an oceanic barrier of >100 km across) provides an ideal location to discriminate local flight from long‐range immigrations; in our study, however, immigrations cannot be ruled out for any single day of trapping due to broad overlap in emergence patterns at Rocky Harbour relative to forest stands with known populations of budworms on the mainland. Based on moderate daily variation in adult abundance, however, major immigration events (defined as external deposition of budworms with large numerical amplitude) likely did not take place at Rocky Harbor between 2014 and 2016. Males were more abundant at light traps coupled with pheromone traps, whereas abundance of males at pheromone traps was similar with or without contiguous light traps. This outcome may be mediated by lower range of attraction for light traps (usually <100 m) and (generally assumed to be several hundreds of meters). Females were equally abundant at light traps with or without pheromone traps. As expected, males were captured earlier in the season at pheromone traps than at light traps, and females occurred later in the season due to protandry. The onset of flight observed at light traps or pheromone traps in 2015 and 2016 occurred 10–15 days later than simulated predictions; caution is thus warranted as to conclusions derived on computer modeling of adult emergence.     

Interaction between caspase-3 and caspase-5 in the stretch-induced programmed cell death in the human periodontal ligament cells

In our previous studies, programmed cell death (PCD) was induced in human periodontal ligament (PDL) cells, through activation of caspase-3 and upregulation of CASP5 gene (encoding caspase-5 protein), in response to mechanical stretch loading. The aim of this study is to explore the relationship between the inflammatory caspase, caspase-5, and the apoptotic executioner protein, caspase-3, in human PDL cells. Here, we found that cyclic stretching upregulated the activity and the protein expression level of caspase-3 and -5 and the addition of the caspase-3 inhibitor or caspase-5 inhibitor significantly inhibited the stretch-induced PCD. Meanwhile, the inhibition of caspase-5 inhibited the activation of caspase-3 and vice versa. The result of coimmunoprecipitation also demonstrated that the expression of caspase-3 was immunoprecipitated with caspase-5. Thus, our study revealed that the in vitro application of cyclic stretching induced PCD by activation of caspase-3 and -5 in human PDL cells, and these two caspases could interact with each other after mechanical stretch loading. The study may facilitate further studies on the mechanism of stretch-induced PCD and help us understand the force-related periodontal homeostasis and remodeling better.     

MiR-128-3p accelerates cardiovascular calcification and insulin resistance through ISL1-dependent Wnt pathway in type 2 diabetes mellitus rats

Vascular calcification is highly prevalent in patients with type 2 diabetes mellitus (T2DM), one of the most common chronic diseases with high morbidity and mortality. In recent years, microRNAs have been widely reported as potential biomarkers for the diagnosis and treatment of T2DM. We hypothesized that miR-128-3p is associated with cardiovascular calcification and insulin resistance (IR) in rats with T2DM by targeting ISL1 via the Wnt pathway. Microarray analysis was adopted to identify differentially expressed genes related to T2DM. T2DM models were induced in rats. Blood samples from normal and T2DM rats were used to detect islet β-cell function, islet sensitivity, and calcium content. Next, islet tissues were obtained to identify the expression of miR-128-3p, ISL1, and the Wnt signaling pathway- and apoptosis-related genes. Finally, apoptosis of islet β-cells was determined by flow cytometry. Through microarray analysis of GSE27382 and GSE23343, ISL1 was found to be downregulated in T2DM. In blood samples from T2DM rats, basic biochemical indicators, IR, and calcium content were increased, and islet sensitivity and islet β-cell function were decreased. Furthermore, upregulation of miR-128-3p and ISL1 gene silencing promoted the expression of Wnt-1, β-catenin, GSK-3β, and Bax and the phosphorylation of β-catenin and GSK-3β, inhibited c-fos, PDX-1, and Bcl-2 expression, and enhanced cell apoptosis. The key findings of our study demonstrate that miR-128-3p aggravates cardiovascular calcification and IR in T2DM rats by downregulating ISL1 through the activation of the Wnt pathway. Thus, miR-128-3p may serve as a potential target for the treatment of T2DM.     

Exosomal microRNA-155-5p from PDLSCs regulated Th17/Treg balance by targeting sirtuin-1 in chronic periodontitis

The mechanism of local inflammation and systemic injury in chronic periodontitis is complicated, in which and exosomes play an important role. In our study, we found that T helper cell 17 (Th17)/regulatory T cell (Treg) balance is destabilized in the peripheral blood of patients with periodontitis, with upregulated Th17 or downregulated Treg, respectively. Porphyromonas gingivalis lipopolysaccharide (LPS) was used to simulate the inflammatory microenvironment of chronic periodontitis. The exosomes were extracted from periodontal ligament stem cells (PDLSCs) in LPS-induced periodontitis environment, which inversely effected on CD4+ T cells under normal and inflammatory conditions. Furthermore, compared with exosomes from normal PDLSCs, lower expression of microRNA-155-5p (miR-155-5p) and higher expression of Sirtuin-1 (SIRT1) were observed in exosomes from LPS-stimulated PDLSCs. Exosomes from PDLSCs alleviated inflammatory microenvironment through Th17/Treg/miR-155-5p/SIRT1 regulatory network. This study aimed to find the “switching” factors that affected the further deterioration of periodontitis to maximally control the multiple downstream damage signal factors to further understand periodontitis and find new targets for its treatment.     

Heme oxygenase-1 reduces the sensitivity to imatinib through nonselective activation of histone deacetylases in chronic myeloid leukemia

Resistance towards imatinib (IM) remains troublesome in treating many chronic myeloid leukemia (CML) patients. Heme oxygenase-1 (HO-1) is a key enzyme of antioxidative metabolism in association with cell resistance to apoptosis. Our previous studies have shown that overexpression of HO-1 resulted in resistance development to IM in CML cells, while the mechanism remains unclear. In the current study, the IM-resistant CML cells K562R indicated upregulation of some of the histone deacetylases (HDACs) compared with K562 cells. Therefore, we herein postulated HO-1 was associated with HDACs. Silencing HO-1 expression in K562R cells inhibited the expression of some HDACs, and the sensitivity to IM was increased. K562 cells transfected with HO-1 resisted IM and underwent obvious some HDACs. These findings related to the inhibitory effects of high HO-1 expression on the reactive oxygen species (ROS) signaling pathway that negatively regulated HDACs. Increased expression of HO-1 activated HDACs by inhibiting ROS production. In summary, HO-1, which is involved in the development of drug resistance in CML cells by regulating the expression of HDACs, is probably a novel target for improving CML therapy.     

Identification of TAF1, HNF4A,and CALM2 as potential therapeutic target genes for liver fibrosis

The molecular mechanism of liver fibrosis caused by hepatitis C virus (HCV) is not clear. The aim of this study is to understand the molecular mechanism of liver fibrosis induced by HCV and to identify potential therapeutic targets for hepatic fibrosis. We analyzed gene expression patterns between high liver fibrosis and low liver fibrosis samples, and identified genes related to liver fibrosis. We identified TAF1, HNF4A, and CALM2 were related to the development of liver fibrosis. HNF4A is important for hepatic fibrogenesis, and upregulation of HNF4A is an ideal choice for treating liver fibrosis. The gene expression of CALM2 is significantly lower in liver fibrosis samples than nonfibrotic samples. TAF1 may serve as a biomarker for liver fibrosis. The results were further validated by an independent data set GSE84044. In summary, our study described changes in the gene expression during the occurrence and development of liver fibrosis. The TAF1, HNF4A, and CALM2 may serve as novel targets for the treatment of liver fibrosis.     

Identification and validation of key genes associated with non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is one of the main causes of death induced by cancer globally. However, the molecular aberrations in NSCLC patients remain unclearly. In the present study, four messenger RNA microarray datasets (GSE18842, GSE40275, GSE43458, and GSE102287) were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between NSCLC tissues and adjacent lung tissues were obtained from GEO2R and the overlapping DEGs were identified. Moreover, functional and pathway enrichment were performed by Funrich, while the protein–protein interaction (PPI) network construction were obtained from STRING and hub genes were visualized and identified by Cytoscape software. Furthermore, validation, overall survival (OS) and tumor staging analysis of selected hub genes were performed by GEPIA. A total of 367 DEGs (95 upregulated and 272 downregulated) were obtained through gene integration analysis. The PPI network consisted of 94 nodes and 1036 edges in the upregulated DEGs and 272 nodes and 464 edges in the downregulated DEGs, respectively. The PPI network identified 46 upregulated and 27 downregulated hub genes among the DEGs, and six (such as CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M) of that have not been identified to be associated with NSCLC so far. Moreover, the expression differences of the mentioned hub genes were consistent with that in lung adenocarcinoma and lung squamous cell carcinoma in the TCGA database. Further analysis showed that all the six hub genes were associated with tumor staging except MYH11, while only the upregulated DEG CENPE was associated with the worse OS of patients with NSCLC. In conclusion, the current study showed that CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M might be the key genes contributed to tumorigenesis or tumor progression in NSCLC, further functional study is needed to explore the involved mechanisms.     

Activation of liver X receptor suppresses osteopontin expression and ameliorates nephrolithiasis

Nephrolithiasis is a common disease of the urinary system, of which idiopathic calcium oxalate (CaOx) kidney stones, in particular, are one of the special types. In the initial stages of CaOx kidney stone formation, Randall's plaques (RPs) develop. Liver X receptors (LXRs) inhibit oxidative stress and inflammatory in other diseases; nevertheless, the role of LXRs in nephrolithiasis has yet to be elucidated. In this study, the role of LXRs in the progression of RP formation was investigated. Microarray analysis revealed that LXR/RXR levels were significantly greater in low-plaque tissues (<5%) than in high-plaque tissues (>5%), confirming the link between LXR activation and RP formation. Correspondingly, expression levels of two LXR target genes, LXRα and LXRβ, were lower in high-plaque tissues than in low-plaque tissues. In vitro, LXR agonist alleviated calcium oxalate monohydrate-induced cellular calcium deposits and apoptosis. LXR activation decreased reactive oxygen species production and gene expression of inflammatory mediators, including osteopontin that has recently been demonstrated to correlate with the development of RPs. Moreover, p38 MAPK and JNK signaling may mediate LXR-regulated expression in HK-2 cells. In an animal model, the deposition was reduced by activating LXR, and osteopontin expression was also inhibited. Our findings suggest a role for LXRs in the progression of idiopathic CaOx kidney stones; LXR agonists may have therapeutic potential for the treatment of nephrolithiasis.