Immunopathological Changes in the Brain of Immunosuppressed Mice Experimentally Infected with Toxocara canis

Toxocariasis is a soil-transmitted helminthozoonosis due to infection of humans by larvae of Toxocara canis. The disease could produce cognitive and behavioral disturbances especially in children. Meanwhile, in our modern era, the incidence of immunosuppression has been progressively increasing due to increased incidence of malignancy as well as increased use of immunosuppressive agents. The present study aimed at comparing some of the pathological and immunological alterations in the brain of normal and immunosuppressed mice experimentally infected with T. canis. Therefore, 180 Swiss albino mice were divided into 4 groups including normal (control) group, immunocompetent T. canis-infected group, immunosuppressed group (control), and immunosuppressed infected group. Infected mice were subjected to larval counts in the brain, and the brains from all mice were assessed for histopathological changes, astrogliosis, and IL-5 mRNA expression levels in brain tissues. The results showed that under immunosuppression, there were significant increase in brain larval counts, significant enhancement of reactive gliosis, and significant reduction in IL-5 mRNA expression. All these changes were maximal in the chronic stage of infection. In conclusion, the immunopathological alterations in the brains of infected animals were progressive over time, and were exaggerated under the effect of immunosuppression as did the intensity of cerebral infection.     

Bone marrow-derived mesenchymal stem cells repair severe acute pancreatitis by secreting miR-181a-5p to target PTEN/Akt/TGF-β1 signaling

BackgroundSevere acute pancreatitis (SAP) is associated with high morbidity and mortality. Bone marrow mesenchymal stem cells (BMSCs) have shown obvious protective effect on SAP. However, little is known about the underlying mechanism. The objective of this study is to unravel the role and regulatory mechanism of miR-181a-5p in BMSCs-mediated pancreatic repair.MethodsBMSCs were isolated from Sprague-Dawley rats and characterized by flow cytometry and Oil Red O staining. Sodium taurocholate- and caerulein-induced models were used as SAP models in vivo and in vitro, respectively. Pancreatic injury were evaluated by H&E and histopathological analysis, as well as by measuring levels of amylase, lipase and cytokines. qRT-PCR and western blotting were performed to detect the level of miR-181a-5p and the protein levels of PTEN/Akt, respectively. ELISA was conducted to detect the levels of TNF-α, IL-1β, IL-6, angiopoietin, IL-4, IL-10 and TGF-β1. The apoptotic rate of AR42 J cells was quantitated by concurrent staining with Annexin-V-FITC and PI.ResultsBMSCs significantly attenuated pancreatic injury in SAP rats by reducing inflammatory infiltration and necrosis, and this effect was abolished by CXCR4 agonist AMD3100. ADM3100 exhibited more severe pancreatic injury and decreased miR-181a-5p levels in the pancreas and serum compared to SAP group. Overexpression of miR-181a-5p in BMSCs (BMSCs-miR-181a-5p) markedly potentiated the protective effect of BMSCs by reducing histological damage and levels of amylase and lipase. Moreover, BMSCs-miR-181a-5p dramatically reduced levels of angiopoietin, TNF-α, IL-1β and IL-6, but induced the levels of IL-4 and IL-10. In caerulein-treated AR42 J cells, co-culturing of BMSCs-miR-181a-5p alleviated caerulein-induced increase of amylase and lipase, and apoptosis via PTEN/Akt/TGF-β1 signaling.ConclusionBMSCs alleviate SAP and reduce inflammatory responses and apoptosis by secreting miR-181a-5p to target PTEN/Akt/TGF-β1 signaling. Hence, BMSCs-miR-181a-5p could serve as potential therapeutic target for SAP.     

Molecular fingerprinting of peppermint (Mentha piperita) and some Mentha hybrids by sequencing and RFLP analysis of the 5S rRNA Non-Transcribed Spacer (NTS) region

Hybridization of species belonging to the genus Mentha is quite common. However, the indicators of hybridity are many and make Mentha hybrids' identification difficult. By using the same molecular strategy that allowed us to unequivocally identify some Mentha species, we amplified the Not-Transcribed-Spacer (NTS) of the 5S-rRNA gene to characterize the industrial crop peppermint, M. × piperita and some important Mentha interspecific hybrids: M. × dalmatica, M. × dumetorum, M. × rotundifolia, M. × maximilianea, M. × smithiana, M. × verticillata, M. × villosa. DNA amplification, sequence and cluster analysis revealed differences in the 5S-rRNA NTS region of Mentha hybrids. Peppermint and all other hybrids were unequivocally discriminated by RFLP analysis by using TaqI restriction enzyme, while a further discrimination between M. × dumetorum and M. × verticillata was obtained by XhoI restriction enzyme. Essential oil composition showed clustering patterns similar to DNA fingerprint, with a clear discrimination between plants producing menthofuran (e.g. M. aquatica and its related hybrids, including peppermint) and those containing piperitenone oxide (M. longifolia and its related hybrids).     

Inhibitors for the bacterial ectonucleotidase Lp1NTPDase from Legionella pneumophila

Legionella pneumophila is an aerobic, Gram-negative bacterium of the genus Legionella, which constitutes the major causative agent of Legionnaires’ disease. Recently a nucleoside triphosphate diphosphohydrolase (NTPDase) from L. pneumophila was identified and termed Lp1NTPDase; it was found to be a structural and functional homolog of mammalian NTPDases catalyzing the hydrolysis of ATP to ADP and ADP to AMP. Its activity is believed to contribute to the virulence of Legionella pneumophila. Therefore Lp1NTPDase inhibitors are considered as novel antibacterial drugs. However, only weakly potent compounds are available so far. In the present study, a capillary electrophoresis (CE)-based enzyme assay for monitoring the Lp1NTPDase activity was established. The enzymatic reaction was performed in a test tube followed by separation of substrate and products by CE and subsequent quantification by UV analysis. After kinetic characterization of the enzyme, a series of 1-amino-4-ar(alk)ylamino-2-sulfoanthraquinone derivatives structurally related to the anthraquinone dye Reactive Blue 2, a non-selective ecto-NTPDase inhibitor, was investigated for inhibitory activity on Lp1NTPDase using the CE-based enzyme assay. Derivatives bearing a large lipophilic substituent (e.g., fused aromatic rings) in the 4-position of the 1-amino-2-sulfoanthraquinone showed the highest inhibitory activity. Compounds with IC₅₀ values in the low micromolar range were identified. The most potent inhibitor was 1-amino-4-[phenanthrene-9-yl-amino]-9,10-dioxo-9,10-dihydroanthracene-2-sulfonate (28, PSB-16131), with an IC₅₀-value of 4.24 μM. It represents the most potent Lp1NTPDase inhibitor described to date. These findings may serve as a starting point for further optimization. Lp1NTPDase inhibition provides a novel approach for the (immuno)therapy of Legionella infections.     

Phosphorylase activity in relation to starch synthesis in developing Hordeum distichum grain

Activity, control and primer requirements of starch phosphorylase in developing barley endosperm were investigated. Phosphorylase was detected in endosperm extracts from 3 days after anthesis. Unprimed activity was predominant between 2 and 10 days after anthesis, when it constituted 70–80% of total activity, but this proportion declined rapidly as the grain developed. The existence of at least 2 isoenzymes was indicated by studies of pH dependence and phosphate inhibition, and was further supported by acrylamide gel electrophoresis and column chromatography using DEAE-cellulose. The two isoenzymes which ere possibly both glyco proteins, appear in barley endosperm soon after anthesis. One appears capable of unprimed activity, and may be associated with the initiation of a-1,2 glucans, which then serve as primers for starch synthetase. This disappears by 13–15 days after anthesis. The other isoenzyme is capable of some unprimed activity but undergoes modification between 15 and 20 days after anthesis, resulting in the loss of unprimed activity. The relevance of the results to initiation of starch synthesis and to starch synthetase in amyloplasts is discussed.     

Heliothrix oregonensis,gen. nov., sp. nov., a phototrophic filamentous gliding bacterium containing bacteriochlorophyll a

An unusual filamentous, gliding bacterium was found in a few hot springs in Oregon where it formed a nearly unispecific top layer of microbial mats. It contained a bacteriochlorophyll a-like pigment and an abundance of carotenoids. There were no chlorosomes or additional chlorophylls. The organism was aerotolerant and appeared to be photoheterotrophic. It was successfully co-cultured with an aerobic chemoheterotroph in a medium containing glucose and casamino acids. Although it has many characteristics in common with the genus Chloroflexus, the lack of chlorosomes and bacteriochlorophyll c and the aerobic nature of this organism indicate that it should be placed in a new genus. This conclusion is supported by 5S rRNA nucleotide sequence data.     

Androgen receptor suppresses vasculogenic mimicry in hepatocellular carcinoma via circRNA7/miRNA7‐5p/VE‐cadherin/Notch4 signalling

Androgen receptor (AR) can suppress hepatocellular carcinoma (HCC) invasion and metastasis at an advanced stage. Vasculogenic mimicry (VM), a new vascularization pattern by which tumour tissues nourish themselves, is correlated with tumour progression and metastasis. Here, we investigated the effect of AR on the formation of VM and its mechanism in HCC. The results suggested that AR could down‐regulate circular RNA (circRNA) 7, up‐regulate micro RNA (miRNA) 7‐5p, and suppress the formation of VM in HCC Small hairpin circR7 (ShcircR7) could reverse the impact on VM and expression of VE‐cadherin and Notch4 increased by small interfering AR (shAR) in HCC, while inhibition of miR‐7‐5p blocked the formation of VM and expression of VE‐cadherin and Notch4 decreased by AR overexpression (oeAR) in HCC. Mechanism dissection demonstrated that AR could directly target the circR7 host gene promoter to suppress circR7, and miR‐7‐5p might directly target the VE‐cadherin and Notch4 3′UTR to suppress their expression in HCC. In addition, knockdown of Notch4 and/or VE‐cadherin revealed that shVE‐cadherin or shNotch4 alone could partially reverse the formation of HCC VM, while shVE‐cadherin and shNotch4 together could completely suppress the formation of HCC VM. Those results indicate that AR could suppress the formation of HCC VM by down‐regulating circRNA7/miRNA7‐5p/VE‐Cadherin/Notch4 signals in HCC, which will help in the design of novel therapies against HCC.     

The protective effects of MSC‐EXO against pulmonary hypertension through regulating Wnt5a/BMP signalling pathway

The aim of the study was to explore the mechanism of mesenchymal stem cell‐derived exosomes (MSC‐EXO) to protect against experimentally induced pulmonary hypertension (PH). Monocrotaline (MCT)‐induced rat model of PH was successfully established by a single intraperitoneal injection of 50 mg/kg MCT, 3 weeks later the animals were treated with MSC‐EXO via tail vein injection. Post‐operation, our results showed that MSC‐EXO could significantly reduce right ventricular systolic pressure (RVSP) and the right ventricular hypertrophy index, attenuate pulmonary vascular remodelling and lung fibrosis in vivo. In vitro experiment, the hypoxia models of pulmonary artery endothelial cell (PAEC) and pulmonary vascular smooth muscle cell (PASMC) were used. We found that the expression levels of Wnt5a, Wnt11, BMPR2, BMP4 and BMP9 were increased, but β‐catenin, cyclin D1 and TGF‐β1 were decreased in MSC‐EXO group as compared with MCT or hypoxia group in vivo or vitro. However, these increased could be blocked when cells were transfected with Wnt5a siRNA in vitro. Taken together, these results suggested that the mechanism of MSC‐EXO to prevent PH vascular remodelling may be via regulation of Wnt5a/BMP signalling pathway.     

Porphyrogenic effects and induction of heme oxygenase in vivo by δ-aminolevulinic acid

The effects of single large doses of the porphyrin-heme precursor ?d-aminolevulinic acid on tissue porphyrins and on δ-aminolevulinate synthase and heme oxygenase, the rate-living enzymes of liver heme synthesis and degradation respectively, were studied in the chick embryo in ovo, in the mouse and in the rat. δ-Aminolevulinic acid treatment produced a distinctive pattern characterized by extensive tissue porphyrin accumulation and alterations in these rate-limiting enzymes in the liver. Repression of basal or allylisopropylacetamide-induced liver δ-aminolevulinate synthase was observed and, in the mouse and the rat, induction of liver heme oxygenase after δ-aminolevulinic acid treatment, in a manner similar to the known effects of hemin on these enzymes. In the chick embryo liver in ovo heme oxygenase was substantially higher than in rat and mouse liver, and was not significantly induced by δ-aminolevulinic acid or other compounds, including hemin, CS₂ and CoCl₂. Levulinic acid, an analogue of δ-aminolevulinic acid, did not induce heme oxygenase in mouse liver. δ-Aminolevunilic acid treatment did not impair ferrochelatase activity but was associated with slight and variable decreases in liver cytochrome P-450. Treatment of chick embryos with a small ‘priming’ dose of 1,4-dihydro-3,5-dicarbethoxycollidine, which impairs liver ferrochelatase activity, accentuated porphyrin accumulation after δ-aminolevulinic acid in the liver. These observations indicate that exogenous δ-aminolevulinic acid is metabolized to porphyrins in a number of tissues and, at least in the liver, to a physiologically significant amount of heme, thereby producing an increase in the size of one or more of the heme pools that regulate both heme systhesis and degradation. It is also possible than when δ-aminolevulinic acid is markedly overproduced in vivo it may be transported to many tissues and re-enter the heme pathway and alter porphyrin-heme metabolism in cells and tissues other than those in which its overproduction primarily occurs.