Reduction In Lesion Development Research Articles

The β-Carboline Harmine Has a Protective Immunomodulatory Role in Nonhealing Cutaneous Leishmaniasis

Cutaneous leishmaniasis affects 1 million people worldwide annually. Although conventional treatments primarily target the parasite, there is growing interest in host immune modulation. In this study, we investigated the impact of synthetic β-carboline harmine (ACB1801), previously shown to be immunoregulatory in cancer, on the pathology caused by a drug-resistant Leishmania major strain causing persistent cutaneous lesions. Exposure to ACB1801 invitro had a modest impact on parasite burden within host macrophages. Moreover, it significantly increased major histocompatibility complex II and costimulatory molecule expression on infected dendritic cells, suggesting an enhanced immune response. Invivo, ACB1801 monotherapy led to a substantial reduction in lesion development and parasite burden in infected C57BL/6 mice, comparable with efficacy of amphotericin B. Transcriptomics analysis further supported ACB1801 immunomodulatory effects, revealing an enrichment of TNF-α, IFN-γ, and major histocompatibility complex II antigen presentation signatures in the draining lymph nodes of treated mice. Flow cytometry analysis confirmed an increased frequency (1.5×) of protective CD4+IFN-γ+TNF-α+ T cells and a decreased frequency (2×) in suppressive IL-10+FoxP3- T cells at the site of infection and in draining lymph nodes. In addition, ACB1801 downregulated the aryl hydrocarbon receptor signaling, known to enhance immunosuppressive cytokines. Thus, these results suggest a potential use for ACB1801 alone or in combination therapy for cutaneous leishmaniasis.

A novel biological control agent against postharvest mango disease caused by Lasiodioplodia theobromae

The antagonist, Talaromyces tratensis KUFA 0091, displayed the ability to control stem end rot caused by L. theobromae on mango cv. ‘Nam Dok Mai’ and ‘Nam Dok Mai no. 4’. The results showed that mango treated with spore suspension of T. tratensis KUFA 0091 at 106 spores/ mL exhibited significant suppression (P < 0.05) of lesion development of up to 85% and 77% on mango cv. ‘Nam Dok Mai’ and ‘Nam Dok Mai no. 4’, respectively, when compared to the control objects. The best suppression of the average lesion was observed on mango cv. “Nam Dok Mai no. 4” when treated with spore suspension at 106 spores/ mL, which resulted in reduction of lesion development from 19.57 cm2 to 2.79 cm2. The results of this study show the potential of T. tratensis KUFA 0091 as a potent agent against mango stem end rot caused by L. theobromae.

Suppression of pecan and peach pathogens on different substrates using Xenorhabdus bovienii and Photorhabdus luminescens

Prior research indicated the ability of concentrated metabolites from Xenorhabdus spp. and Photorhabdus spp. to suppress a variety of peach and pecan diseases in vitro, and on detached pecan leaves or terminals. In the current study, our objectives were to (1) determine if bacterial broths (in addition to concentrated metabolites tested previously) have suppressive ability and (2) determine if metabolites or bacterial broths are active in a soil medium. In laboratory studies, two pathogens of pecan (Fusicladium effusum and Phytophthora cactorum) and one peach pathogen (Armillaria tabescens) were tested for susceptibility to Xenorhabdus bovienii (SN) and Photorhabdus luminescens (VS) bacterial broths or concentrated metabolites on three different substrates. Treatments were applied to lesions of F. effusum on terminals to ascertain any suppressive effect on sporulation, to A. tabescens in soil to determine effect on survival of mycelia, and to lesions caused by P. cactorum on pecan leaf surfaces to assess any reduction in lesion development. Acetone (the metabolite solvent), un-inoculated media (tryptic soy broth) and water were included as controls. The X. bovienii metabolite treatment was as efficacious as a commercial fungicide (fenbuconazole) in reducing sporulation of F. effusum on pecan terminals. The P. luminescens metabolite treatment also caused reduced sporulation relative to water and acetone controls but bacterial broths had no effect. In contrast, all bacterial broth and metabolite treatments suppressed lesion growth caused by P. cactorum (measured on detached leaves maintained on agar). However, in soil, only the P. luminescens metabolite treatment was suppressive to A. tabescens (this is the first report of Photorhabdus or Xenorhabdus toxicity to Armillaria spp.). This study provides a basis for further research on the use of Xenorhabdus and Photorhabdus metabolites or bacterial broth for suppression of pecan and peach diseases.

Low-level atmospheric ozone exposure induces protection against Botrytis cinerea with down-regulation of ethylene-, jasmonate- and pathogenesis-related genes in tomato fruit

The aim of this study was to determine if ozone exposure could prevent spoilage in tomato fruit by fungal infection and to explore concomitant changes in expression of genes involved in signal transduction (ethylene, jasmonic acid and C 6-aldehydes) and defence-related (chitinases, glucanases and defensin) pathways. Tomato fruit ( Lycopersicon esculentum Mill. cv. Mareta) were exposed to low-level ozone enrichment (0.05 μmol mol −1) for up to 6 days and then wounded and/or inoculated with Botrytis cinerea (grey mould) and transferred for one or two weeks’ post-fumigation exposure to ‘clean’ (i.e. Charcoal/Purafil ®-filtered) air in chilled storage (13 °C). Control fruit were maintained throughout in ‘clean’ air. Pre-exposure to ozone resulted in a marked reduction in lesion development when fruit were subsequently wounded and inoculated with a mycelial plug. Tomato fruit subjected to ozone-enrichment not only showed enhanced protection against fungal infection, but also retained firmness in comparison with fruit maintained in ‘clean’ air. Ozone treatment resulted in strong inhibition of expression of both signal transduction (1-aminocyclopropane-1-carboxylic acid oxidase, allene oxide synthase and hydroperoxide lyase), and defence-related (acidic chitinase, basic chitinase, acidic glucanase, basic glucanase, plant defensin) genes, and the pattern of change was consistent with suppression of fungal growth. Overall, ozone exposure would appear to enhance tomato resistance to B. cinerea infection and has potential commercial applications.

Vasoprotective and Atheroprotective Effects of Angiotensin (1-7) in Apolipoprotein E–Deficient Mice

To evaluate the effectiveness of long-term angiotensin (Ang) (1-7) treatment to inhibit the progression of atherosclerosis in apolipoprotein E-deficient (ApoE(-/-)) mice. Ang (1-7) is a heptapeptide fragment that has been proposed to counterregulate the Ang II proatherogenic effects. The effect of long-term 4-week Ang (1-7) treatment on both inhibition of atherosclerotic lesion development and improvement of endothelial function was examined in apolipoprotein E(-/-) mice that had been fed an atherogenic high-fat (21%) diet for 16 weeks. Chronic Ang (1-7) treatment significantly improved endothelial function, an effect reversed with either angiotensin type 2 (AT(2)) or Mas receptor blockade. In these vessels, Ang (1-7) treatment significantly decreased superoxide production and increased endothelial nitric oxide synthase immunoreactivity when compared with vehicle treatment. These effects were blocked by both AT(2) and Mas receptor antagonists. Lesion development, assessed as both fatty deposits (oil red O) and intima to media ratio, was also significantly decreased with Ang (1-7) treatment compared with respective controls. Cotreatment with either AT(2) or Mas receptor antagonists reversed Ang (1-7)-mediated reduction in lesion development. Long-term Ang (1-7) treatment caused both vasoprotection, via improvement in endothelial function, and atheroprotection, with a reduction in lesion progression in a model of atherosclerosis. These effects appear to be mediated by the restoration of nitric oxide bioavailability and involve a complex interaction of both Mas and AT(2) receptors.

Abstract 5164: Loss of SOCS3 Expression in T Cells Reveals a Regulatory Role for Interleukin-17 in Atherosclerosis

Atherosclerosis is an inflammatory vascular disease responsible for the first cause of mortality worldwide. Recent studies have clearly highlighted the critical role of the immuno-inflammatory balance in the modulation of disease development and progression. However, the immuno-regulatory pathways that control atherosclerosis remain largely unknown. Here, we show that loss of Suppressor of Cytokine Signaling 3 (SOCS3) in T cells increases both interleukin (IL)17 and IL10 production, induces an anti-inflammatory macrophage phenotype, and leads to unexpected IL17-dependent reduction in lesion development and vascular inflammation. In vivo administration of IL17 reduces endothelial vascular cell adhesion molecule (VCAM)-1 expression, vascular T cell infiltration and significantly limits atherosclerotic lesion development. In contrast, overexpression of SOCS3 in T cells reduces IL17 and accelerates atherosclerosis. We also show that in human lesions, increased levels of Stat3 phosphorylation and IL17 are associated with a stable plaque phenotype. These results identify novel SOCS3-controlled IL17 regulatory pathways in atherosclerosis and may have important implications to the understanding of the increased susceptibility to vascular inflammation in patients with dominant-negative STAT3 mutations and defective Th17 differentiation.

Loss of SOCS3 expression in T cells reveals a regulatory role for interleukin-17 in atherosclerosis

Atherosclerosis is an inflammatory vascular disease responsible for the first cause of mortality worldwide. Recent studies have clearly highlighted the critical role of the immunoinflammatory balance in the modulation of disease development and progression. However, the immunoregulatory pathways that control atherosclerosis remain largely unknown. We show that loss of suppressor of cytokine signaling (SOCS) 3 in T cells increases both interleukin (IL)-17 and IL-10 production, induces an antiinflammatory macrophage phenotype, and leads to unexpected IL-17–dependent reduction in lesion development and vascular inflammation. In vivo administration of IL-17 reduces endothelial vascular cell adhesion molecule–1 expression and vascular T cell infiltration, and significantly limits atherosclerotic lesion development. In contrast, overexpression of SOCS3 in T cells reduces IL-17 and accelerates atherosclerosis. We also show that in human lesions, increased levels of signal transducer and activator of transcription (STAT) 3 phosphorylation and IL-17 are associated with a stable plaque phenotype. These results identify novel SOCS3-controlled IL-17 regulatory pathways in atherosclerosis and may have important implications for the understanding of the increased susceptibility to vascular inflammation in patients with dominant-negative STAT3 mutations and defective Th17 cell differentiation.

Increased activation of nuclear factor-kappa B (NF-κB) in isolated peritoneal macrophages of patients with endometriosis

Endometriosis is characterized by pelvic inflammation that shows an increased number of activated peritoneal macrophages and their secreted products such as cytokines, growth factors, and angiogenic factors. Our results show that activation of nuclear factor-kappa B (NF-kappaB), a pro-inflammatory transcription factor, is statistically significantly increased in peritoneal macrophages from patients with endometriosis when compared with controls.

Increased tolerance to Phytophthora citrophthora in transgenic orange plants constitutively expressing a tomato pathogenesis related protein PR-5

Phytophthora citrophthora is the most widely spread oomycete plant pathogen over all the citrus growing areas and represents one of the major causes of crop losses. Constitutive over-expression of genes encoding proteins involved in plant defence mechanisms to disease is one of the strategies proposed to increase plant tolerance to oomycete and fungal pathogens. P23 (PR-5), a 23-kDa pathogenesis-related protein similar to osmotins, is induced in tomato (Lycopersicon esculentum Mill. cv. Rutgers) plants when they are infected with citrus exocortis viroid, and its antifungal activity has been demonstrated in in vitro assays. We have successfully produced transgenic orange (Citrus sinensis L. Obs. cv. Pineapple) plants bearing a chimeric gene construct consisting of the cauliflower mosaic virus 35S promoter and the coding region of the tomato pathogenesis-related PR-5. Nine regenerated transgenic lines constitutively expressed the PR protein. They were challenged with Phytophthora citrophthora using a detached bark assay. A significant reduction in lesion development was consistently observed in one transgenic line in comparison to the control plants. This same line achieved plant survival rates higher than control plants when transgenic trees were inoculated with oomycete cultures. These results provide evidence for the in vivo activity of the tomato PR-5 protein against Phytophthora citrophthora, and suggest that this may be employed as a strategy aimed at engineering Phytophthora disease resistance in citrus.

Ornithine Decarboxylase of Stagonospora (Septoria) nodorum Is Required for Virulence toward Wheat

A knockout strain of Stagonospora (Septoria) nodorum lacking the single ornithine decarboxylase (ODC) allele has been created by targeted gene replacement. A central region of the S. nodorum ODC gene was isolated by polymerase chain reaction using degenerate oligonucleotides and used to probe a lambda genomic library. The gene was sequenced and the encoded ODC protein sequence was shown to be similar to those from other fungi. The functionality of the S. nodorum ODC was confirmed by complementation of an Aspergillus nidulans mutant (puA) strain devoid of ODC activity, restoring growth in the absence of exogenous polyamines. Sporulation of the transformants was reduced suggesting abberant regulation of the S. nodorum gene in A. nidulans. Transformation-mediated gene replacement was used to create strains which were auxotrophic for putrescine and lack ODC coding sequences. Pathogenicity studies on these mutants showed that they are greatly reduced in virulence compared with non-disrupted transformants. This confirms that the strains carrying an ODC disruption cannot obtain sufficient polyamines from the host plant for normal growth and, thus, that fungal ODC may be a suitable target for chemical intervention.

Expression of a pathogenesis-related peroxidase of Stylosanthes humilis in transgenic tobacco and canola and its effect on disease development

In this study, we have investigated the effect of the expression of a cDNA (Shpx6a) encoding a pathogenesis-related peroxidase in the tropical forage legume Stylosanthes humilis on fungal disease resistance in transgenic tobacco and canola plants. Constitutive expression of Shpx6a cDNA was obtained using the 35S CaMV promoter in transgenic tobacco and canola plants and resulted in two to three fold increases in total peroxidase activity using guaiacol as a substrate. The peroxidase encoded by Shpx6a was shown to be located in the apoplast. Inoculation experiments using fungal pathogens Phytophthora parasitica var nicotianae (black shank disease of tobacco) and Leptosphaeria maculans (blackleg disease of canola) showed that expression of Shpx6a peroxidase resulted a small (20–30%) but statistically significant reduction in lesion development in the progeny of transgenic tobacco and canola lines. The enhanced level of tolerance to fungal diseases in both species appears to correlate with the level of peroxidase activity across several lines of transgenic plants. These results provide evidence for a role for the Shpx6a peroxidase in plant defence and suggest that it may be employed as a component of strategies aimed at the engineering of disease resistance.

Pentadecapeptide BPC 157 interactions with adrenergic and dopaminergic systems in mucosal protection in stress.

Since superior protection against different gastrointestinal and liver lesions and antiinflammatory and analgesic activities were noted for pentadecapeptide BPC (an essential fragment of an organoprotective gastric juice protein named BPC), the beneficial mechanism of BPC 157 and its likely interactions with other systems were studied. Hence its beneficial effects would be abolished by adrenal gland medullectomy, the influence of different agents affecting alpha, beta, and dopamine receptors on BPC 157 gastroprotection in 48 h restraint stress was further investigated. Animals were pretreated (1 hr before stress) with saline (controls) or BPC 157 (dissolved in saline) (10 microg or 10 ng/kg body wt intraperitoneally or intragastrically) applied either alone to establish basal conditions or, when manipulating the adrenergic or dopaminergic system, a simultaneous administration was carried out with various agents with specific effects on adrenergic or dopaminergic receptors [given in milligrams per kilogram intraperitoneally except for atenolol, which was given subcutaneously] phentolamine (10.0), prazosin (0.5), yohimbine (5.0), clonidine (0.1) (alpha-adrenergic domain), propranolol (1.0), atenolol (20.0) (beta-adrenergic domain), domperidone (5.0), and haloperidol (5.0) (peripheral/central dopamine system). Alternatively, agents stimulating adrenergic or dopaminergic systems--adrenaline (5.0) or bromocriptine (10.0)--were applied. A strong protection, noted following intragastric or intraperitoneal administration of BPC 157, was fully abolished by coadministration of phentolamine, clonidine, and haloperidol, and consistently not affected by prazosin, yohimbine, or domperidone. Atenolol abolished only intraperitoneal BPC 157 protection, whereas propranolol affected specifically intragastric BPC 157 protection. Interestingly, the severe course of lesion development obtained in basal conditions, unlike BPC 157 gastroprotection, was not influenced by the application of these agents. In other experiments, when adrenaline and bromocriptine were given simultaneously, a strong reduction of lesion development was noted. However, when applied separately, only adrenaline, not bromocriptine, has a protective effect. Thus, a complex protective interaction with both alpha-adrenergic (eg, catecholamine release) and dopaminergic (central) systems could be suggested for both intragastric and intraperitoneal BPC 157 administration. The involvement of beta-receptor stimulation in BPC 157 gastroprotection appears to be related to the route of BPC 157 administration. The demonstration that a combined stimulation of adrenergic and dopaminergic systems by simultaneous prophylactic application of adrenaline (alpha- and beta-receptor stimulant) and bromocriptine (dopamine receptor agonist) may significantly reduce restraint stress lesions development provides insight for further research on the beneficial mechanism of BPC 157.

Inhibition of aflatoxin-initiated preneoplastic liver lesions by low dietary protein.

The development of aflatoxin B1-induced hepatic preneoplastic lesions was significantly modified by varying the level of dietary casein fed to animals during the post-dosing period. Using gamma-glutamyl transferase staining to identify areas of cellular alteration, we observed that animals fed a 5% casein diet showed a 75% reduction in lesion development as compared to animals fed a 20% casein diet. Increasing the level of dietary casein from 20% to 40% produced no further increase in response. The results of the study, showing an inhibition in the preneoplastic development by a reduction dietary casein after aflatoxin dosing, suggest that low dietary casein inhibits the promotional phase of the ultimate neoplastic response.