Transcription of the human microsomal epoxide hydrolase gene (EPHX1) is regulated by an HNF-4α/CAR/RXR/PSF complex

Microsomal epoxide hydrolase (mEH) is a bifunctional protein that plays a central role in the metabolism of numerous xenobiotics as well as mediating the sodium-dependent transport of bile acids into hepatocytes where they are involved in cholesterol excretion and metabolism, lipid digestion and regulating numerous signaling pathways. Previous studies have demonstrated the critical role of GATA-4 and a C/EBPα–NF/Y complex in the regulation of the mEH gene (EPHX1). In this study we show that HNF-4α and CAR/RXR also bind to the proximal promoter region and regulate EPHX1 expression. Bile acids, which inhibit the expression of HNF-4α also decrease the expression of EPHX1. Studies also established that the binding of HNF-4α was essential for the activation of EPHX1 activity by CAR suggesting the formation of a complex between these adjacent factors. The nature of this regulatory complex was further explored using a biotinylated oligonucleotide of this region in conjunction with BioMag beads and mass spectrometric analysis which demonstrated the presence of an additional inhibitory factor (PSF), confirmed by co-immunoprecipitation and ChIP analyses, which interacted with DNA-bound CAR/RXR/HNF-4α forming a 4-component regulatory complex.     

注射小针刀联合奥施康定治疗癌性疼痛的临床疗效研究

目的:观察注射小针刀联合奥施康定治疗癌性疼痛的临床疗效。方法:选择我院收治的66例癌性疼痛患者,根据随机方法将入选病例分为注射针刀组(针刀配合奥施康定)、奥施康定组(单纯西药奥施康定),每组各33例。针刀组每日给予口服药物、隔日给予针刀治疗;奥施康定组每日给予口服药物,14日为1个观察周期。治疗前后测定疼痛程度(NRS)并分析疼痛缓解度(PAR)。结果:治疗组临床总有效率为90.9%,对照组为84.9%,两组比较差异无统计学意义(P0.05)。治疗后,两组NRS评分均较治疗前显著降低(P0.05),且治疗组比对照组改善更为显著(P0.01)。结论:注射小针刀联合奥施康定对癌性疼痛的治疗疗效较单用奥施康定更好。     

Cytotoxic Constituents and Mechanism from Peganum harmala

Peganum harmala L. is a traditional Chinese and Uygur medicine used to treat cancer. Bioactivity‐guided fractionation was applied to determine the cytotoxic constituents from P. harmala. A novel triterpenoid and a phenolic glycoside were isolated and identified, as well as seven known compounds. The novel metabolites were elucidated to be 3α‐acetoxy‐27‐hydroxyolean‐12‐en‐28‐oic acid methyl ester ( 1 , OA) and N‐acetyl‐9‐syringinoside ( 9 ). Some compounds exhibited potent cytotoxicity against human tumor cells. Among them, OA showed the highest cytotoxicity against human lung cancer cells A549 with an IC₅₀ value of 8.03 ± 0.81 μm . OA had a potent anti‐NSCLC cell activity by interfering with the epidermal growth factor receptor (EGFR) activation and its downstream signaling, and could exert an antiproliferative effect by inactivation of EGFR‐driven antiapoptotic pathway followed by the release of mitochondrial cytochrome c, which might prove to be a promising leading compound for the development of an anti‐lung cancer drug.     

A transcriptome‐wide study on the microRNA‐ and the Argonaute 1‐enriched small RNA‐mediated regulatory networks involved in plant leaf senescence

Leaf senescence is an important physiological process during the plant life cycle. However, systemic studies on the impact of microRNAs (miRNAs) on the expression of senescence‐associated genes (SAGs) are lacking. Besides, whether other Argonaute 1 (AGO1)‐enriched small RNAs (sRNAs) play regulatory roles in leaf senescence remains unclear. In this study, a total of 5,123 and 1,399 AGO1‐enriched sRNAs, excluding miRNAs, were identified in Arabidopsis thaliana and rice (Oryza sativa), respectively. After retrieving SAGs from the Leaf Senescence Database, all of the AGO1‐enriched sRNAs and the miRBase‐registered miRNAs of these two plants were included for target identification. Supported by degradome signatures, 200 regulatory pairs involving 120 AGO1‐enriched sRNAs and 40 SAGs, and 266 regulatory pairs involving 64 miRNAs and 42 SAGs were discovered in Arabidopsis. Moreover, 13 genes predicted to interact with some of the above‐identified target genes at protein level were validated as regulated by 17 AGO1‐enriched sRNAs and ten miRNAs in Arabidopsis. In rice, only one SAG was targeted by three AGO1‐enriched sRNAs, and one SAG was targeted by miR395. However, five AGO1‐enriched sRNAs were conserved between Arabidopsis and rice. Target genes conserved between the two plants were identified for three of the above five sRNAs, pointing to the conserved roles of these regulatory pairs in leaf senescence or other developmental procedures. Novel targets were discovered for three of the five AGO1‐enriched sRNAs in rice, indicating species‐specific functions of these sRNA–target pairs. These results could advance our understanding of the sRNA‐involved molecular processes modulating leaf senescence.     

Specific protein homeostatic functions of small heat‐shock proteins increase lifespan

During aging, oxidized, misfolded, and aggregated proteins accumulate in cells, while the capacity to deal with protein damage declines severely. To cope with the toxicity of damaged proteins, cells rely on protein quality control networks, in particular proteins belonging to the family of heat‐shock proteins (HSPs). As safeguards of the cellular proteome, HSPs assist in protein folding and prevent accumulation of damaged, misfolded proteins. Here, we compared the capacity of all Drosophila melanogaster small HSP family members for their ability to assist in refolding stress‐denatured substrates and/or to prevent aggregation of disease‐associated misfolded proteins. We identified CG14207 as a novel and potent small HSP member that exclusively assisted in HSP70‐dependent refolding of stress‐denatured proteins. Furthermore, we report that HSP67BC, which has no role in protein refolding, was the most effective small HSP preventing toxic protein aggregation in an HSP70‐independent manner. Importantly, overexpression of both CG14207 and HSP67BC in Drosophila leads to a mild increase in lifespan, demonstrating that increased levels of functionally diverse small HSPs can promote longevity in vivo.     

Dickkopf‐1‐promoted vasculogenic mimicry in non‐small cell lung cancer is associated with EMT and development of a cancer stem‐like cell phenotype

To characterize the contributions of Dickkopf‐1 (DKK1) towards the induction of vasculogenic mimicry (VM) in non‐small cell lung cancer (NSCLC), we evaluated cohorts of primary tumours, performed in vitro functional studies and generated xenograft mouse models. Vasculogenic mimicry was observed in 28 of 205 NSCLC tumours, while DKK1 was detected in 133 cases. Notably, DKK1 was positively associated with VM. Statistical analysis showed that VM and DKK1 were both related to aggressive clinical course and thus were indicators of a poor prognosis. Moreover, expression of epithelial‐mesenchymal transition (EMT)‐related proteins (vimentin, Slug, and Twist), cancer stem‐like cell (CSC)‐related proteins (nestin and CD44), VM‐related proteins (MMP2, MMP9, and vascular endothelial‐cadherin), and β‐catenin‐nu were all elevated in VM‐positive and DKK1‐positive tumours, whereas the epithelial marker (E‐cadherin) was reduced in the VM‐positive and DKK1‐positive groups. Non‐small cell lung cancer cell lines with overexpressed or silenced DKK1 highlighted its role in the restoration of mesenchymal phenotypes and development of CSC characteristics. Moreover, DKK1 significantly promotes NSCLC tumour cells to migrate, invade and proliferate. In vivo animal studies demonstrated that DKK1 enhances the growth of transplanted human tumours cells, as well as increased VM formation, mesenthymal phenotypes and CSC properties. Our results suggest that DKK1 can promote VM formation via induction of the expression of EMT and CSC‐related proteins. As such, we feel that DKK1 may represent a novel target of NSCLC therapy.     

Discovery of a novel small molecule agonist scaffold for the APJ receptor

The apelinergic system includes a series of endogenous peptides apelin, ELABELA/TODDLER and their 7-transmembrane G-protein coupled apelin receptor (APJ, AGTRL-1, APLNR). The APJ receptor is an attractive therapeutic target because of its involvement in cardiovascular diseases and potentially other disorders including liver fibrosis, obesity, diabetes, and neuroprotection. To date, pharmacological characterization of the APJ receptor has been limited due to the lack of small molecule functional agonists or antagonists. Through focused screening we identified a drug-like small molecule agonist hit 1 with a functional EC₅₀ value of 21.5 ± 5 μM and binding affinity (K_i) of 5.2 ± 0.5 μM. Initial structure–activity studies afforded compound 22 having a 27-fold enhancement in potency and the first sub-micromolar full agonist with an EC₅₀ value of 800 ± 0.1 nM and K_i of 1.3 ± 0.3 μM. Preliminary SAR, synthetic methodology, and in vitro pharmacological characterization indicate this scaffold will serve as a favorable starting point for further refinement of APJ potency and selectivity.

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