A transcriptomic snapshot of early molecular communication between Pasteuria penetrans and Meloidogyne incognita

© The Author(s). 2018Background: Southern root-knot nematode Meloidogyne incognita (Kofoid and White, 1919), Chitwood, 1949 is a key pest of agricultural crops. Pasteuria penetrans is a hyperparasitic bacterium capable of suppressing the nematode reproduction, and represents a typical coevolved pathogen-hyperparasite system. Attachment of Pasteuria endospores to the cuticle of second-stage nematode juveniles is the first and pivotal step in the bacterial infection. RNA-Seq was used to understand the early transcriptional response of the root-knot nematode at 8 h post Pasteuria endospore attachment. Results: A total of 52,485 transcripts were assembled from the high quality (HQ) reads, out of which 582 transcripts were found differentially expressed in the Pasteuria endospore encumbered J2 s, of which 229 were up-regulated and 353 were down-regulated. Pasteuria infection caused a suppression of the protein synthesis machinery of the nematode. Several of the differentially expressed transcripts were putatively involved in nematode innate immunity, signaling, stress responses, endospore attachment process and post-attachment behavioral modification of the juveniles. The expression profiles of fifteen selected transcripts were validated to be true by the qRT PCR. RNAi based silencing of transcripts coding for fructose bisphosphate aldolase and glucosyl transferase caused a reduction in endospore attachment as compared to the controls, whereas, silencing of aspartic protease and ubiquitin coding transcripts resulted in higher incidence of endospore attachment on the nematode cuticle. Conclusions: Here we provide evidence of an early transcriptional response by the nematode upon infection by Pasteuria prior to root invasion. We found that adhesion of Pasteuria endospores to the cuticle induced a down-regulated protein response in the nematode. In addition, we show that fructose bisphosphate aldolase, glucosyl transferase, aspartic protease and ubiquitin coding transcripts are involved in modulating the endospore attachment on the nematode cuticle. Our results add new and significant information to the existing knowledge on early molecular interaction between M. incognita and P. penetrans.Peer reviewedFinal Published versio

2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

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Atrial Fibrillation and Epicardial Adipose Tissue

Atrial fibrillation (AF) is associated with increased cardiovascular morbidity and mortality with projections that it will affect 8–12 million people in the United States by 2050. Obesity has been identified as an important independent risk factor for AF, with weight loss leading to decreased AF burden and improved arrhythmia free survival. The precise mechanisms by which obesity contributes to AF remain poorly understood. However, it has recently been speculated that epicardial adipose tissue (EAT) may be a key mediator between obesity and AF. EAT is a visceral fat depot with anatomic contiguity to the myocardium. Under physiological conditions, EAT plays an important protective role via mechanical, metabolic, and thermogenic functions. However, under pathophysiological conditions, it may contribute to development of AF through various mechanisms including fatty infiltration, fibrosis, inflammation, oxidative stress, atrial remodelling, and genetic factors. EAT has been shown in multiple studies to be a risk factor for development of AF and predictor of recurrence after catheter ablation. The mechanisms directly linking EAT to the pathogenesis of AF also are uncertain. Multiple pharmacologic options have been proposed to target EAT; however, the efficacy of targeted reduction in EAT requires further investigation