Root-knot nematodes (RKNs, Meloidogyne incognita) are economically important endoparasites with a wide host range. We used a comprehensive transcriptomic approach to investigate the expression of both tomato and RKN genes in tomato roots at five infection time intervals from susceptible plants and two infection time intervals from resistant plants, grown under soil conditions. Differentially expressed genes during susceptible (1827, tomato; 462, RKN) and resistance (25, tomato; 160, RKN) interactions were identified. In susceptible responses, tomato genes involved in cell wall structure, development, primary and secondary metabolite, and defence signalling pathways, together with RKN genes involved in host parasitism, development and defence, are discussed. In resistance responses, tomato genes involved in secondary metabolite and hormone-mediated defence responses, together with RKN genes involved in starvation stress-induced apoptosis, are discussed. In addition, 40 novel differentially expressed RKN genes encoding secretory proteins were identified. Our findings provide novel insights into the temporal regulation of genes involved in various biological processes from tomato and RKN simultaneously during susceptible and resistance responses, and reveal the involvement of a complex network of biosynthetic pathways during disease development.

Hepatic ischemia-reperfusion injury (IRI) and associated inflammation contributes to liver dysfunction and complications after liver surgery and transplantation. Mesenchymal stem cells (MSC) have been reported to reduce hepatic IRI because of their reparative immunomodulatory effects in injured tissues. Recent studies have highlighted beneficial effects of extracellular vesicles from MSCs (MSC-EV) on tissue injury. The effects of systemically administered mouse bone marrow derived MSC-EV were evaluated in an experimental murine model of hepatic IRI induced by cross clamping the hepatic artery and portal vein for 90 minutes followed by reperfusion for periods of upto 6 hours. Compared with controls, intravenous administration of MSC-EV 30 minutes prior to IRI dramatically reduced the extent of tissue necrosis, decreased caspase-3 positive and apoptotic cells, and reduced serum aminotransferase levels. MSC-EV increased hepatic mRNA expression of NACHT, LRR and PYD domains-containing protein 12 (Nlrp12), and the chemokine (C-X-C motif) ligand 1 (CXCL1), and reduced mRNA expression of several inflammatory cytokines such as IL-6 during IRI. MSC-EV increased cell viability and suppressed both oxidative injury and NF-κB activity in AML12 murine hepatocytes in vitro. In conclusion, the administration of EV derived from bone marrow derived MSCs may ameliorate hepatic IRI by reducing hepatic injury through modulation of the inflammatory response.

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Circulating microRNAs that are associated with specific diseases have garnered much attention for use in diagnostic assays. However, detection of disease-associated miRNA can be affected by several factors such as release of contaminating cellular miRNA during sample collection, variations due to amplification of transcript for detection, or controls used for normalization for accurate quantitation. We analyzed circulating miRNA in serum and plasma samples obtained concurrently from 28 patients, using a Nanostring quantitative assay platform. Total RNA concentration ranged from 32–125 μg/ml from serum and 30–220 μg/ml from plasma. Of 798 miRNAs, 371 miRNAs were not detected in either serum or plasma samples. 427 were detected in either serum or plasma but not both, whereas 151 miRNA were detected in both serum and plasma samples. The diversity of miRNA detected was greater in plasma than in serum samples. In serum samples, the number of detected miRNA ranged from 3 to 82 with a median of 17, whereas in plasma samples, the number of miRNA detected ranged from 25 to 221 with a median of 91. Several miRNA such as miR451a, miR 16-5p, miR-223-3p, and mir25-3p were highly abundant and differentially expressed between serum and plasma. The detection of endogenous and exogenous control miRNAs varied in serum and plasma, with higher levels observed in plasma. Gene expression stability identified candidate invariant microRNA that were highly stable across all samples, and could be used for normalization. In conclusion, there are significant differences in both the number of miRNA detected and the amount of miRNA detected between serum and plasma. Normalization using miRNA with constant expression is essential to minimize the impact of technical variations. Given the challenges involved, ideal candidates for blood based biomarkers would be those that are indifferent to type of body fluid, are detectable and can be reliably quantitated.

Current approaches for collection of extracellular vesicles (EV) are based on classical cell culture media production. This involves collection from cells grown in flasks, and can require multiple rounds of centrifugation or filtration, followed by ultracentrifugation or density gradient centrifugation. There are several limitations of these approaches, for example, they require a large input volume, the yield and concentration is low, and the process is time consuming. Most cell cultures require the use of fetal bovine serum which contains a large amount of endogenous EV that can contaminate isolations of cell-derived EVs. The use of cell cultures within a hollow fiber bioreactor could address many of these limitations and produce a continuous source of highly concentrated EVs without contamination from serum EVs, and that are suitable for downstream applications.