Cooperative Regulatory Functions of miR858 and MYB83 during Cyst Nematode Parasitism.

MicroRNAs (miRNAs) recently have been established as key regulators of transcriptome reprogramming that define cell function and identity. Nevertheless, the molecular functions of the greatest number of miRNA genes remain to be determined. Here, we report cooperative regulatory functions of miR858 and its MYB83 transcription factor target gene in transcriptome reprogramming during Heterodera cyst nematode parasitism of Arabidopsis (Arabidopsis thaliana). Gene expression analyses and promoter-GUS fusion assays documented a role of miR858 in posttranscriptional regulation of MYB83 in the Heterodera schachtii-induced feeding sites, the syncytia. Constitutive overexpression of miR858 interfered with H. schachtii parasitism of Arabidopsis, leading to reduced susceptibility, while reduced miR858 abundance enhanced plant susceptibility. Similarly, MYB83 expression increases were conducive to nematode infection because overexpression of a noncleavable coding sequence of MYB83 significantly increased plant susceptibility, whereas a myb83 mutation rendered the plants less susceptible. In addition, RNA-seq analysis revealed that genes involved in hormone signaling pathways, defense response, glucosinolate biosynthesis, cell wall modification, sugar transport, and transcriptional control are the key etiological factors by which MYB83 facilitates nematode parasitism of Arabidopsis. Furthermore, we discovered that miR858-mediated silencing of MYB83 is tightly regulated through a feedback loop that might contribute to fine-tuning the expression of more than a thousand of MYB83-regulated genes in the H. schachtii-induced syncytium. Together, our results suggest a role of the miR858-MYB83 regulatory system in finely balancing gene expression patterns during H. schachtii parasitism of Arabidopsis to ensure optimal cellular function.

Sural nerve conduction studies using ultrasound-guided needle positioning: Influence of age and recording location.

INTRODUCTION: The aim of this study was to compare results of orthodromic sural nerve conduction studies (NCS) using ultrasound-guided needle positioning (USNP) to those of surface electrode recordings. METHODS: Fifty-one healthy subjects, aged 24-80 years, divided into 5 age groups, were examined. Electrical stimuli were applied behind the lateral malleolus. Sensory nerve action potentials (SNAPs) were recorded 8 and 15 cm proximally with surface and needle electrodes. RESULTS: Mean SNAP amplitudes (surface / needle electrodes) averaged 12.7 (SD 7.6) µV / 40.6 (SD 20.8) µV (P < 0.001) for subjects aged 20-29 years, and 5.0 (SD 2.4) µV / 19.8 (SD 9.8) µV (P < 0.01) for subjects >60 years of age. SNAP amplitudes were smaller at the proximal recording location. CONCLUSIONS: NCS using USNP yield higher amplitude responses than surface electrodes in all age groups at all recording sites. SNAP amplitudes are smaller at proximal recording locations due to sural nerve branching. Muscle Nerve 54: 879-882, 2016.

Plasma Levels of K18 Fragments Do Not Correlate with Alcoholic Liver Fibrosis.

Background/Aims: Noninvasive markers of liver fibrosis in alcoholic liver disease (ALD) are crucial to establish early intervention. Previous studies have suggested that plasma levels of cleaved keratin-18 (K18; M30) fragments can predict the severity of liver disease. The aim of this study was to correlate plasma M30 levels with stages of liver fibrosis in ALD. Methods: Patients with ALD (n=139, 79.1% males) and liver histology were included, and plasma samples were collected to quantify plasma M30 levels. Patients were stratified into five groups by fibrosis stage (F0=14; F1=15; F2=35; F3=17; and F4=58) according to the Kleiner score. Differences between groups were evaluated using the chi-square test or analysis of variance. Trends by fibrosis stage were calculated by logistic regression analysis, and sensitivity, specificity and positive and negative predictive values were determined. Results: There were no significant differences in M30 levels among fibrosis stages. The correlation between plasma M30 levels and fibrosis was poor (Pearson's correlation coefficient= 0.13, Spearman rho=0.20 [p=0.02]), and M30 levels did not correlate with alcohol-specific histological features. However, significant correlations of M30 levels with aspartate aminotransferase (Spearman rho=0.653, p<0.001) and alanine aminotransferase (spearman rho=0.432, p<0.001) were found. m30 levels of>200 U/L reveal a sensitivity for predicting cirrhosis of 84.5% with a negative predictive value of 73.5%. Conclusions: Plasma M30 levels are often elevated in ALD and correlate with serum transaminases but do not reflect fibrosis. The usefulness as a prognostic marker awaits evaluation in prospective studies.