Project description:Arabidopsis thaliana has been used regularly as a model plant in gene expression studies on transcriptional reprogramming upon pathogen infection, such as that by Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), or when subjected to stress hormone treatments including jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA). RT-qPCR has been extensively employed to quantitate these gene expression changes. However, the accuracy of the quantitation is largely dependent on the stability of the expressions of reference genes used for normalization. Recently, RNA-seq has been widely used to mine stably expressed genes for use as references in RT-qPCR. However, the amplification step in RNA-seq creates an intrinsic bias against those genes with relatively low expression levels, and therefore does not provide an accurate quantification of all expressed genes. In this study, we employed mass spectrometry-based label-free quantification (LFQ) in proteomic analyses to identify those proteins with abundances unaffected by Pst DC3000 infection. We verified, using RT-qPCR, that the levels of their corresponding mRNAs were also unaffected by Pst DC3000 infection. In addition, using RT-qPCR, we verified that the mRNAs were stably expressed upon stress hormone treatments including JA, SA, and ABA. Results indicated that the candidate genes identified here had stable expressions upon these stresses and are suitable to be used as reference genes for RT-qPCR. Among the 18 candidate reference genes reported in this study, many of them had greater expression stability than the commonly used reference genes, such as ACT7, in previous studies. Here, besides proposing more appropriate reference genes for Arabidopsis expression studies, we also demonstrated the capacity of mass spectrometry-based LFQ to quantify protein abundance and the possibility to extend protein expression studies to the transcript level.
Project description:In this study we present an experimental pipeline that takes into consideration sample collection, processing, enrichment, and the subsequent comparative analysis of circulating small ribonucleic acids using small RNA sequencing and RT-qPCR. Initially, a panel of miRNAs dysregulated in circulating blood from breast cancer patients compared to healthy women were identified using small RNA sequencing. MiR-320a was identified as the most dysregulated miRNA between the two female cohorts. Total RNA and enriched small RNA populations (<30 bp) isolated from peripheral blood from the same female cohort samples were then tested using a miR-320a RT-qPCR assay. When total RNA was analyzed with this miR-320a RT-qPCR assay, a 2.3-fold decrease in expression levels was observed between blood samples from healthy controls and breast cancer patients. However, upon enrichment for the small RNA population and subsequent analysis of miR-320a using RT-qPCR, its dysregulation in breast cancer patients was more pronounced with an 8.89-fold decrease in miR-320a expression.
Project description:This study aims to investigate the microRNA profile in human medullary carcinoma tissue by microarray analysis and RT-qPCR. Matched tumor and adjacent normal tissue were obtained from 24 patients and analysed using human microRNA Microarray Kit Agilent, Differentially expressed miRNAs were validated by RT-qPCR using 37 other tumors samples (validation set), Associations of microRNA expression with clinicopathological items were studied
Project description:To further our understanding of the biological mechanisms regulating voluntary physical activity levels, we measured differential miRNA expression in two strains of mice that have been repeatedly shown to have inherently high and low voluntary physical activity levels measured by wheel running. RNA from skeletal muscle (soleus and extensor digitorum longus (EDL)) and nucleus accumbens in the brain tissues were evaluated by microarray. There were no other variables besides inherent strain differences. Thirteen miRNAs from nucleus accumbens, 22 from soleus, and nine miRNAs from EDL were determined to be differentially expressed by microarray analysis. RT-qPCR validated mir-342b-3p and 466d-3p to be differentially expressed in the NA, and miR-466b-3p in the soleus.
Project description:Cerebral ischemia/reperfusion injury (CI/RI), including neurological behavior deficits, cerebral infarction, blood-brain barrier (BBB) dysfunction, and neuroinflammation, et al. is a severe challenge in treatment of ischemic stroke. Traditional Chinese medicine (TCM) with the characteristics of multi-components and multi-functions for multiple targets/pathways has been historically used in the treatment of stroke and post stroke recovery in China. QiShenYiQi (QSYQ), a representative component-based Chinese medicine, is capable of reducing organ injury caused by ischemia/reperfusion via multiple mechanisms. Recently, we have previously reported that the positive action of QSYQ against the acute phase of CI/RI is partly via modulation of neuroinflammatory response. However, the effects and underlying mechanisms of QSYQ on subacute phase of CI/RI remain unknown, which are aimed to investigate in present study. The pharmacological action of QSYQ treatment on brain damage was estimated in the experimental stroke rats underwent 90 min ischemia and 8 days reperfusion by assessing the neurological and locomotor deficits, cerebral infarction, brain edema, and BBB integrity. Furthermore, we used TMT-based quantitative proteomics technology to identify significantly differentially expressed proteins following QSYQ treatment, which could give important clues for revealing the possible mechanism underlying the positive role of QSYQ in CI/RI. Besides, immunohistochemistry, western blot analysis, RT-qPCR, and rat ELISA kits were executed to further verify the accuracy of proteomics analysis results. As a consequence, we found that treatment with QSYQ (600mg/kg) for 7 days obviously improved neurological and behavioral impairment, attenuated infarct volume and brain edema, and alleviated BBB breakdown in stroke rats. Bioinformatics analysis suggested that differentially expressed protein galectin-3 mediated inflammatory response was closely related to the beneficial effect of QSYQ. Results of immunohistochemistry, western blot analysis and RT-qPCR showed that the model rats treated with QSYQ (600mg/kg) markedly downregulated the mRNA and protein expression level of galectin-3 in brain tissues compared to the untreated stroke rats. In addition, the decrease of mRNA level in brain tissues and contents in serum of TNF-α and IL-6 following QSYQ treatment were also observed. These interesting finding manifested that the effective action of QSYQ against subacute phase of CI/RI was partly via regulating galectin-3 mediated inflammatory reaction.