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575 BACTERIAL DNA TRANSLOCATION INTO LIVER DURING INDUCTION OF EXPERIMENTAL CIRRHOSIS AND ITS RELATIONSHIP WITH THE INCREMENT OF HEPATIC NORADRENALINE
POSTERS Methods: We measured cerebral oxygen metabolism, CBF, and brain ammonia uptake by dynamic PET/CT in nine cirrhotic patients during an episode of overt HE type C, and again after recovery. Nine patients with cirrhosis with no history of HE were controls. Results: The mean cerebral oxygen metabolism was 0.73 mmol oxygen/mL brain/min during HE and rose to 0.91 after recovery (P < 0.05). The CBF was 0.28 mL blood/mL brain/min during HE and rose to 0.38 after recovery (P < 0.05). Both recovery values were similar to the control values. Blood ammonia decreased by 20% after recovery (P < 0.05) whereas brain ammonia uptake did not decrease (P > 0.30). Conclusions: The decreased cerebral oxygen metabolism and CBF during the episode of HE were reversible and thus associated to the HE rather than the liver disease as such. Moreover, the similar cerebral ammonia uptake during and after HE does not support a primary toxic effect of ammonia on brain oxidative metabolism. 574 ALTERED NEUROMODULATOR EXPRESION WITHIN THE SUPERIOR MESENTERIC GANGLIA MAY CAUSE SYMPATHETIC ATROPHY IN PORTAL HYPERTENSIVE RATS N. Ezkurdia1 , I. Raurell1 , S. Rodriguez1 , R. Esteban1,2 , J. Genesca` 1,2 , M. Martell1 . 1 Vall d’Hebron Institut de Recerca, Hospital Vall d’Hebron, Universidad Aut´ onoma de Barcelona, Barcelona, 2 CIBERehd, Instituto de Salud Carlos III, Madrid, Spain E-mail: [email protected] Background: Blockade of sensory afferent nerves in portal hypertensive rats simultaneously prevents c-fos activation in cardiovascular regulatory nuclei of the brain, sympathetic atrophy of nerves innervating the superior mesenteric artery and hemodynamic alterations. Considering this neuronal pathway, the signal responsible for the post-ganglionic sympathetic atrophy could be originating in pre-ganglionic fibers that synapse at the superior mesenteric ganglion (SMG). Objective: To investigate alterations in the expression of neuromodulators that may be involved in regulating neuronal activity within the sympathetic SMG during portal hypertension. Methods: Portal vein ligated (PVL, n = 7) and sham operated (n = 7) rats. SMG sample extraction for (i) Western blot analysis of tyrosine hydroxylase (TH) (adrenergic marker), semaphorin 3A (Sema3A) (neuronal growth inhibitor), nerve growth factor (NGF) (neurotrophin) and its precursor proNGF as well as neurotrophin receptors TrkA and p75NTR (proliferation or axonal regression, respectively); (ii) Localization and quantitation of Sema3A by immunofluorescence; (iii) Simultaneous co-localization of Sema3A with Th, neuronal nitric oxide synthase, calcitonin gene related peptide and vesicular acetylcholine transporter (VAChT), (iv) Localization of Sema3A receptor neuropilin-1, p75NTR and TrkA by immunofluorescence. Results: Th expression was decreased in the somas of neurons within the SMG of PVL comparing to sham (p = 0.008) confirming adrenergic deficit in splanchnic sympathetic nerves. By contrast, an increment of NGF (p = 0.01), proNGF (p = 0.01) and Sema3A (p = 0.005) was observed in PVL comparing to sham. Quantitation of Sema3A by immunofluorescence confirmed this increment (p < 0.001) exhibiting a pattern around adrenergic neurons only colocalizing with VAChT, which suggests their origin in sympathetic pre-ganglionic cholinergic nerves. Preliminary results confirmed the expression of neuropilin-1, TrkA and p75NTR on adrenergic neurons. Finally, a significant increment in the p75NTR /TrkA ratio of PVL was observed comparing to sham (p = 0.029). The overexpression of p75NTR and especially the p75NTR /TrkA ratio observed in SMG of PVL points to the activation of the p75NTR receptor, mostly by pro-NGF, inducing apoptosis and axonal regression. To this effect might contribute the downregulation of TrkA receptor by Sema3A. S228
Conclusion: The adrenergic alteration and sympathetic atrophy observed in mesenteric vessels during portal hypertension could be caused by alterations on the neuromodulation leading to axonal regression and apoptopsis. 575 BACTERIAL DNA TRANSLOCATION INTO LIVER DURING INDUCTION OF EXPERIMENTAL CIRRHOSIS AND ITS RELATIONSHIP WITH THE INCREMENT OF HEPATIC NORADRENALINE 1 3 P. Zapater1 , I. Gomez-Hurtado ´ , G. Peiro´ 2 , M. Perez-Mateo ´ , J. Such1 , R. Frances ´ 1 . 1 CIBERehd – Unidad Hep´ atica, Hospital General Universitario de Alicante, 2 Unidad de Investigaci´ on, Hospital General Universitario de Alicante, 3 Unidad Hep´ atica, Hospital General Universitario de Alicante, Alicante, Spain E-mail: [email protected] Background: Sympathetic nervous system (SNS) is activated in decompensated cirrhosis and, in rats, exerts an immune suppressive role over host’s defense. We have demonstrated the increasing incidence of bacterial DNA (bactDNA) translocation during induction of experimental liver cirrhosis. Therefore we hypothesize that SNS must be hyperactivated, favouring fibrosis progression and bactDNA translocation in the liver of these animals. Methods: Liver damage was induced in Balb/c mice by oral administration of CCl4 . Laparotomies were performed at weeks 6, 10, 13 and 16 in a subgroup of CCl4 -treated mice (n = 6/week) and control animals (n = 4/week). Liver tissue specimens were evaluated histologically. Pro-fibrogenic genes expression, bactDNA, cytokine, noradrenaline (NE) and alpha- and beta-adrenergic receptor gene levels were measured in the liver. Results: Fibrosis progression was confirmed by histological findings and pro-fibrogenic gene expression levels. BactDNA was present in the liver of 16% (week-6), 16% (week-10), 66% (week-13) and 66% (week-16) treated animals but in none of controls. Highest liver TNF-alpha and IL-6 levels in CCl4− treated animals were present at week-10 (TNF-alpha 40.1±11.8 pg/mL vs 19.8±2.1 pg/mL in controls; IL-6 52.7±5.3 pg/mL vs 17.1±4.4 pg/mL in controls). TNF-alpha and IL-6 values were significantly higher in mice with bactDNA in liver (TNF-alpha: 54.8±2.3 pg/mL vs 32.6±3.5 pg/mL bactDNA- at week10; IL-6: 56.3±5.4 pg/mL vs 51.0±5.0 pg/mL bactDNA- at week10). Liver NE levels were increased in CCl4− treated animals along the study. A significantly up-regulation in hepatic NE levels was observed at week-13 and week-16 in animals with bactDNA in liver (311.3 pg/mL±130.2 vs 80.9±22.0 pg/mL in bactDNA- at week13; 452.0±95.4 pg/mL vs 30.81±16.0 pg/mL bactDNA- at week-16). Highest liver NE levels corresponded with lowest liver TNF-alpha and IL-6 amounts. Alpha-1 adrenergic receptor levels were constant and significantly higher in treated vs control animals whereas alpha-2 adrenergic receptor showed a significant increment in CCl4 -treated animals at week-13 and week-16. BactDNA in liver was associated with a significantly further up-regulation of alpha-2 adrenergic receptor levels at week-16, matching up with highest NE levels and bactDNA translocation rates. Conclusions: CCl4-induced liver inflammation is affected by an NE and alpha-2 adrenergic receptor up-regulation that, in turn, may facilitate bactDNA translocation in the liver of injured animals.
Journal of Hepatology 2012 vol. 56 | S225–S388
Conclusion: The adrenergic alteration and sympathetic atrophy observed in mesenteric vessels during portal hypertension could be caused by alterations on the neuromodulation leading to axonal regression and apoptopsis. 575 BACTERIAL DNA TRANSLOCATION INTO LIVER DURING INDUCTION OF EXPERIMENTAL CIRRHOSIS AND ITS RELATIONSHIP WITH THE INCREMENT OF HEPATIC NORADRENALINE 1 3 P. Zapater1 , I. Gomez-Hurtado ´ , G. Peiro´ 2 , M. Perez-Mateo ´ , J. Such1 , R. Frances ´ 1 . 1 CIBERehd – Unidad Hep´ atica, Hospital General Universitario de Alicante, 2 Unidad de Investigaci´ on, Hospital General Universitario de Alicante, 3 Unidad Hep´ atica, Hospital General Universitario de Alicante, Alicante, Spain E-mail: [email protected] Background: Sympathetic nervous system (SNS) is activated in decompensated cirrhosis and, in rats, exerts an immune suppressive role over host’s defense. We have demonstrated the increasing incidence of bacterial DNA (bactDNA) translocation during induction of experimental liver cirrhosis. Therefore we hypothesize that SNS must be hyperactivated, favouring fibrosis progression and bactDNA translocation in the liver of these animals. Methods: Liver damage was induced in Balb/c mice by oral administration of CCl4 . Laparotomies were performed at weeks 6, 10, 13 and 16 in a subgroup of CCl4 -treated mice (n = 6/week) and control animals (n = 4/week). Liver tissue specimens were evaluated histologically. Pro-fibrogenic genes expression, bactDNA, cytokine, noradrenaline (NE) and alpha- and beta-adrenergic receptor gene levels were measured in the liver. Results: Fibrosis progression was confirmed by histological findings and pro-fibrogenic gene expression levels. BactDNA was present in the liver of 16% (week-6), 16% (week-10), 66% (week-13) and 66% (week-16) treated animals but in none of controls. Highest liver TNF-alpha and IL-6 levels in CCl4− treated animals were present at week-10 (TNF-alpha 40.1±11.8 pg/mL vs 19.8±2.1 pg/mL in controls; IL-6 52.7±5.3 pg/mL vs 17.1±4.4 pg/mL in controls). TNF-alpha and IL-6 values were significantly higher in mice with bactDNA in liver (TNF-alpha: 54.8±2.3 pg/mL vs 32.6±3.5 pg/mL bactDNA- at week10; IL-6: 56.3±5.4 pg/mL vs 51.0±5.0 pg/mL bactDNA- at week10). Liver NE levels were increased in CCl4− treated animals along the study. A significantly up-regulation in hepatic NE levels was observed at week-13 and week-16 in animals with bactDNA in liver (311.3 pg/mL±130.2 vs 80.9±22.0 pg/mL in bactDNA- at week13; 452.0±95.4 pg/mL vs 30.81±16.0 pg/mL bactDNA- at week-16). Highest liver NE levels corresponded with lowest liver TNF-alpha and IL-6 amounts. Alpha-1 adrenergic receptor levels were constant and significantly higher in treated vs control animals whereas alpha-2 adrenergic receptor showed a significant increment in CCl4 -treated animals at week-13 and week-16. BactDNA in liver was associated with a significantly further up-regulation of alpha-2 adrenergic receptor levels at week-16, matching up with highest NE levels and bactDNA translocation rates. Conclusions: CCl4-induced liver inflammation is affected by an NE and alpha-2 adrenergic receptor up-regulation that, in turn, may facilitate bactDNA translocation in the liver of injured animals.
Journal of Hepatology 2012 vol. 56 | S225–S388