A set of Arabidopsis thaliana miRNAs involve shoot regeneration in vitro

Plant miRNAs, the critical regulator of gene expression, involve many development processes in vivo. However, the roles of miRNAs in plant cell proliferation and redifferntiation in vitro remain unknown. To determine better the molecular mechanism of these processes, we have recently reported that a set of miRNAs with different expression patterns between cells of totipotent and non-totipotent Arabidopsis calli. Some of these were specifically up- or downregulated during callus formation or shoot regeneration, and other development. Among them, miR160, and one of its target genes, ARF10, regulated Arabidopsis in vitro shoot regeneration via WUS, CLV3 and CUC1/2. The miR160-overexpressing, 35S transgenic lines, exhibited reduced shoot regeneration efficiency. The mARF10, a miR160-resistant form of ARF10, showed a high level of shoot regeneration ability. In the transgenic, expression of the above shoot meristem-specific genes was elevated, which is consistent with the improved shoot regeneration. In contrast, the ARF10 deficient knockout mutant produced fewer regenerated shoot. However, overexpressors of ARF10 were only marginally more efficient than the wild type with the respect to shoot regeneration. Our observation strongly supports that proper shoot regeneration from in vitro cultured cells requires the miR160-directed negative influence of ARF10. The enhanced expression of ARF10 is likely to have contributed to the improved regeneration ability.     

结直肠癌组织异常表达miRNA的鉴定

目的：筛选结直肠癌组织异常表达的miRNAs。方法：采用Agilem基因芯片（V12．0）分析结直肠癌组织及其配对正常粘膜组织间差异表达的miRNAs,MiRNAs错误发生率（FDR）〈0．05和微矩阵显著性分析（SAM）q值〈0．05为差异显著。结果：鉴定出结直肠癌中32个差异表达的miRNAs,显著上调和下调各16个。实时定量PCR（RT—qPCR）证实基因芯片中4个表达上调的miRNAs在结直肠癌组织中也显著上调。结论：MiRNA基因芯片鉴定出了结直肠癌组织一系列新的差异表达的miRNAs。     

Genetic Variants in Epidermal Growth Factor Receptor Pathway Genes and Risk of Esophageal Squamous Cell Carcinoma and Gastric Cancer in a Chinese Population

The epidermal growth factor receptor (EGFR) signaling pathway regulates cell proliferation, differentiation, and survival, and is frequently dysregulated in esophageal and gastric cancers. Few studies have comprehensively examined the association between germline genetic variants in the EGFR pathway and risk of esophageal and gastric cancers. Based on a genome-wide association study in a Han Chinese population, we examined 3443 SNPs in 127 genes in the EGFR pathway for 1942 esophageal squamous cell carcinomas (ESCCs), 1758 gastric cancers (GCs), and 2111 controls. SNP-level analyses were conducted using logistic regression models. We applied the resampling-based adaptive rank truncated product approach to determine the gene- and pathway-level associations. The EGFR pathway was significantly associated with GC risk (P = 2.16×10⁻³). Gene-level analyses found 10 genes to be associated with GC, including FYN, MAPK8, MAP2K4, GNAI3, MAP2K1, TLN1, PRLR, PLCG2, RPS6KB2, and PIK3R3 (P<0.05). For ESCC, we did not observe a significant pathway-level association (P = 0.72), but gene-level analyses suggested associations between GNAI3, CHRNE, PAK4, WASL, and ITCH, and ESCC (P<0.05). Our data suggest an association between specific genes in the EGFR signaling pathway and risk of GC and ESCC. Further studies are warranted to validate these associations and to investigate underlying mechanisms.     

The Systematic Classification of Gallbladder Stones

Background

To develop a method for systematic classification of gallbladder stones, analyze the clinical characteristics of each type of stone and provide a theoretical basis for the study of the formation mechanism of different types of gallbladder stones.

Methodology

A total of 807 consecutive patients with gallbladder stones were enrolled and their gallstones were studied. The material composition of gallbladder stones was analyzed using Fourier Transform Infrared spectroscopy and the distribution and microstructure of material components was observed with Scanning Electron Microscopy. The composition and distribution of elements were analyzed by an X-ray energy spectrometer. Gallbladder stones were classified accordingly, and then, gender, age, medical history and BMI of patients with each type of stone were analyzed.

Principal Findings

Gallbladder stones were classified into 8 types and more than ten subtypes, including cholesterol stones (297), pigment stones (217), calcium carbonate stones (139), phosphate stones (12), calcium stearate stones (9), protein stones (3), cystine stones (1) and mixed stones (129). Mixed stones were those stones with two or more than two kinds of material components and the content of each component was similar. A total of 11 subtypes of mixed stones were found in this study. Patients with cholesterol stones were mainly female between the ages of 30 and 50, with higher BMI and shorter medical history than patients with pigment stones (P<0.05), however, patients with pigment, calcium carbonate, phosphate stones were mainly male between the ages of 40 and 60.

Conclusion

The systematic classification of gallbladder stones indicates that different types of stones have different characteristics in terms of the microstructure, elemental composition and distribution, providing an important basis for the mechanistic study of gallbladder stones.     

Reference gene selection and validation for mRNA expression analysis by RT-qPCR in murine M1- and M2-polarized macrophage

Molecular Biology Reports - Murine bone marrow-derived macrophages (M0) and M1- and M2-polarized macrophages are being widely used as a laboratory model for polarized macrophages related molecular...     

Injectable and moldable hydrogels for use in sensitive and wide range strain sensing applications

Recently, the use of hybrid double network (DN) hydrogels has become prominent due to their enhanced mechanical properties, which has opened the door for new applications of these soft materials. Only a few of these gels have demonstrated both injectable and moldable capabilities. In this work, we report the mechanical properties, gauge factor (GF) values and demonstrate both the injectability and moldability of a gelatin/polyacrylamide DN hydrogel. We optimized several parameters, such as, gelatin to polyacrylamide ratio, reactant concentrations and metal ion concentration, to produce a gelatin/polyacrylamide hydrogel with superior mechanical properties. The highest water content gel was capable of withstanding strains of 5000% before failure. These gels were facilely injected into molds where they effectively changed shape and maintained similar properties prior to remolding. When 20 mM calcium was doped into a similar gel, a tensile strength of 1.71 MPa was achieved. Aside from improving the mechanical properties of the gels, both Ca²⁺ and Mg²⁺ also improved their conductivity, so they were tested for use as strain sensors. The sensitivity of the hydrogel strain sensors were measured using the GF. For the 20 mM Ca²⁺ hydrogel, these GF values ranged from 1.63 to 6.85 for strains of 100% to 2100% respectively. Additionally, the sensors showed good stability over continuous cyclic stretching, demonstrating their long term reliability for strain sensing.     

Inhibition of microRNA-103 attenuates inflammation and endoplasmic reticulum stress in atherosclerosis through disrupting the PTEN-mediated MAPK signaling

Atherosclerosis (AS), a chronic disorder of large arteries, is the underlying pathological process of heart disease and stroke. Former researchers have found that microRNAs (miRs) are involved in the several key processes of AS. Apolipoprotein E knockout (ApoE^−/−) mice fed a high-fat-diet (HFD) to establish AS model. The expression of miR-103 was characterized in the mice model. The effects of miR-103 on inflammation and endoplasmic reticulum stress (ERS) were analyzed when the expression of miR-103 was inhibited in ApoE ^−/− mice fed an HFD and human aortic endothelial cells (HAECs) exposed to oxidized low-density lipoprotein (ox-LDL). The relationship between miR-103 and phosphatase and tensin homolog (PTEN) was identified by luciferase activity detection and real-time quantitative polymerase chain reaction (RT-qPCR). Gain- and loss-function approaches were further applied for investigating the regulatory effects of miR-103 and PTEN on ERS. Role of MAPK signaling was then analyzed using PD98059 to block this pathway. miR-103 was highly expressed in the ApoEApoE ^−/− mice fed an HFD. Downregulation of miR-103 suppressed inflammation and ERS in endothelial cells isolated from ApoE ^−/− mice fed a HFD and ox-LDL-exposed HAECs. In addition, miR-103 can target PTEN and downregulate its expression. Overexpression of PTEN reversed the miR-103-induced activation of MAPK signaling. Moreover, PTEN upregulation or MAPK signaling inhibition ease miR-103-induced inflammation and ERS in vivo and in vitro. Thus, miR-103 depletion restrains the progression of AS through blocking PTEN-mediated MAPK signaling.