Background & Aims: Bacterial infections commonly occur in decompensated cirrhosis resulting from bacterial translocation from the intestine. We studied the role of intestinal macrophages and the epithelial barrier in cirrhosis. Methods: Forty-four patients with NASH/ASH cirrhosis (decom-pensated n = 29, compensated n = 15) and nineteen controls undergoing endoscopy were recruited. Serum was obtained and LPS and LBP levels determined. Intestinal macrophages were characterized by flow cytometry, immunohistochemistry, and nitric oxide (NO) production measured in supernatant of cultured duodenal samples. Quantitative RT-PCR was performed on duo-denal biopsies assessing 84 inflammatory genes. Protein levels of cytokines/chemokines were assessed in serum and superna-tant. The duodenal wall was assessed by electron microscopy, tight junction protein expression determined by RT-PCR, immu-nohistochemistry, and Western blot and, functional analysis performed by transepithelial resistance measurement and per-meability studies. Results: Increased plasma LPS, LBP levels and higher numbers of duodenal CD33 + /CD14 + /Trem-1 + macrophages, synthesizing iNOS and secreting NO were present in decompensated cirrhosis. Upregulation of IL-8, CCL2, CCL13 at the transcriptional level, and increased IL-8, and IL-6 were detected in supernatant and serum in cirrhosis. IL-6 and IL-8 co-localised with iNOS + and CD68 + , but not with CD11c + cells. Electron microscopy demon-strated an intact epithelial barrier. Increased Claudin-2 was detected by Western blot and immunohistochemistry, while decreased transepithelial resistance and increased duodenal per-meability were detected in decompensated cirrhosis. Conclusions: Our study shows the presence of activated CD14 +-Trem-1 + iNOS + intestinal macrophages, releasing IL-6, NO, and increased intestinal permeability in patients with cirrhosis, sug-gesting that these cells may produce factors capable of enhancing permeability to bacterial products.

BackgroundNodules play an important role in fixing atmospheric nitrogen for soybean growth. Premature senescence of nodules can negatively impact on nitrogen availability for plant growth and, as such, we need a better understanding of nodule development and senescence. Cysteine proteases are known to play a role in nodule senescence, but knowledge is still fragmented regarding the function their inhibitors (cystatins) during the development and senescence of soybean nodules. This study provides the first data with regard to cystatin expression during nodule development combined with biochemical characterization of their inhibition strength.ResultsSeventy nine non-redundant cysteine protease gene sequences with homology to papain, belonging to different subfamilies, and several legumain-like cysteine proteases (vacuole processing enzymes) were identified from the soybean genome assembly with eighteen of these cysteine proteases actively transcribed during nodule development and senescence. In addition, nineteen non-redundant cystatins similar to oryzacystatin-I and belonging to cystatin subgroups A and C were identified from the soybean genome assembly with seven actively transcribed in nodules. Most cystatins had preferential affinity to cathepsin L-like cysteine proteases. Transcription of cystatins Glyma05g28250, Glyma15g12211, Glyma15g36180 particularly increased during onset of senescence, possibly regulating proteolysis when nodules senesce and undergo programmed cell death. Both actively transcribed and non-actively transcribed nodule cystatins inhibited cathepsin-L- and B-like activities in different age nodules and they also inhibited papain and cathepsin-L activity when expressed and purified from bacterial cells.ConclusionsOverlap in activities and specificities of actively and non-actively transcribed cystatins raises the question if non-transcribed cystatins provide a reservoir for response to particular environments. This data might be applicable to the development of strategies to extend the active life span of nodules or prevent environmentally induced senescence.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0294-3) contains supplementary material, which is available to authorized users.

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Phytocystatins are a well-characterized class of naturally occurring protease inhibitors that function by preventing the catalysis of papain-like cysteine proteases. The action of cystatins in biotic stress resistance has been studied intensively, but relatively little is known about their functions in plant growth and defence responses to abiotic stresses, such as drought. Extreme weather events, such as drought and flooding, will have negative impacts on the yields of crop plants, particularly grain legumes. The concepts that changes in cellular protein content and composition are required for acclimation to different abiotic stresses, and that these adjustments are achieved through regulation of proteolysis, are widely accepted. However, the nature and regulation of the protein turnover machinery that underpins essential stress-induced cellular restructuring remain poorly characterized. Cysteine proteases are intrinsic to the genetic programmes that underpin plant development and senescence, but their functions in stress-induced senescence are not well defined. Transgenic plants including soybean that have been engineered to constitutively express phytocystatins show enhanced tolerance to a range of different abiotic stresses including drought, suggesting that manipulation of cysteine protease activities by altered phytocystatin expression in crop plants might be used to improve resilience and quality in the face of climate change.

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