Paula Giménez

Protective effect of Bifidobacterium pseudocatenulatum CECT7765 against induced bacterial antigen translocation in experimental cirrhosis.

Intervention in the gut ecosystem is considered as a potential strategy to treat liver diseases and their complications. We have evaluated the effects of Bifidobacterium pseudocatenulatum CECT7765 on bacterial translocation and the liver status in experimental cirrhosis.

Absent in melanoma 2 triggers a heightened inflammasome response in ascitic fluid macrophages of patients with cirrhosis.

BACKGROUND & AIMS Inflammation is a common event in the pathogenesis of liver cirrhosis. The inflammasome pathway has acquired significant relevance in the pathogenesis of inflammation, but its role in the inflammatory response in patients with decompensated cirrhosis remains unexplored. METHODS We performed a prospective study in which 44 patients with decompensated cirrhosis and 12 healthy volunteers were included. We isolated macrophages from blood and ascitic fluid and assessed the expression and activation of the inflammasome, its response to priming by bacterial products, and its association with the degree of liver disease. RESULTS Macrophages from sterile ascitic fluids showed constitutive activation of caspase-1 and a marked increase in the expression of IL-1β, IL-18, and absent in melanoma 2 (AIM2) when compared to blood macrophages. Pre-stimulation of blood-derived macrophages from cirrhotic patients with bacterial DNA increased the expression of AIM2 and induced a higher AIM2-mediated inflammasome response than priming with other bacterial products such as lipopolysaccharide. By contrast, activation of the AIM2 inflammasome did not require a priming signal in ascitic fluid-derived macrophages, demonstrating the preactivated state of the inflammasome in these cells. Last, higher IL-1β and IL-18 production by ascitic fluid macrophages correlated with a more advanced Child-Pugh score. CONCLUSIONS The inflammasome is highly activated in the ascitic fluid of cirrhotic patients, which may explain the exacerbated inflammatory response observed in these patients under non-infected conditions. Clinically, activation of the inflammasome is associated with a higher degree of liver disease.

Use of proton pump inhibitors decrease cellular oxidative burst in patients with decompensated cirrhosis.

Proton pump inhibitors (PPIs) are commonly used antisecretory drugs and have been linked to an increased risk of bacterial infections in cirrhosis. We investigated whether the treatment with PPIs in cirrhosis affects the oxidative burst activity of granulocytes and monocytes and its possible interference with serum norfloxacin (Nflx) levels in these patients.

Role of interleukin 10 in norfloxacin prevention of luminal free endotoxin translocation in mice with cirrhosis

BACKGROUND & AIMS Bacterial endotoxin is present in patients with advanced cirrhosis and can induce an immunogenic response without an overt infection. Norfloxacin is a gram-negative bactericidal drug able to maintain low endotoxin levels and stimulate IL-10 production. We aimed at investigating the role of IL-10 in decreasing endotoxin absorption in cirrhotic mice treated with norfloxacin. METHODS Cirrhosis was induced by carbon tetrachloride or bile duct ligation in wild type and IL10-deficient mice with or without norfloxacin prior to an intragastrical administration of E. coli, K. pneumonia or E. faecalis. Spontaneous and induced bacterial translocation, free endotoxin and cytokine levels were evaluated in mesenteric lymph nodes. Intestinal permeability was followed by fluorimetry and barrier integrity markers were measured in disrupted intestinal samples. The inflammatory-modulating mechanism was characterized in purified intestinal mononuclear cells. RESULTS Norfloxacin reduced spontaneous and induced MLN positive-cultures in wild type and IL-10-deficient animals. However, reduction of free endotoxin levels was associated with norfloxacin in wild type but not in IL-10-deficient mice. Wild type but not IL-10-deficient mice treated with norfloxacin significantly normalized intestinal permeability and improved gut barrier integrity markers. The toll-like receptor 4-mediated pro-inflammatory milieu was modulated by norfloxacin in a concentration-dependent manner in cultured intestinal mononuclear cells of wild type mice but not of IL-10-deficient mice. The restoration of IL-10 levels in IL-10-deficient animals reactivated the norfloxacin effect on inflammatory-modulation, gut barrier permeability, and luminal endotoxin absorption. CONCLUSION Norfloxacin not only reduces gram-negative intestinal flora but also participates in an IL-10-driven modulation of gut barrier permeability, thus reducing luminal free endotoxin absorption in experimental cirrhosis.

Beta-adrenergic receptor 1 selective antagonism inhibits norepinephrine-mediated TNF-alpha downregulation in experimental liver cirrhosis.

Background Bacterial translocation is a frequent event in cirrhosis leading to an increased inflammatory response. Splanchnic adrenergic system hyperactivation has been related with increased bacterial translocation. We aim at evaluating the interacting mechanism between hepatic norepinephrine and inflammation during liver damage in the presence of bacterial-DNA. Animals and Methods Forty-six mice were included in a 16-week protocol of CCl4-induced cirrhosis. Laparotomies were performed at weeks 6, 10, 13 and 16. A second set of forty mice injected with a single intraperitoneal dose of CCl4 was treated with saline, 6-hydroxidopamine, Nebivolol or Butoxamine. After 5 days, mice received E. coli-DNA intraperitoneally. Laparotomies were performed 24 hours later. Liver bacterial-DNA, norepinephrine, TNF-alpha, IL-6 and beta-adrenergic receptor levels were measured. Results Bacterial-DNA translocation was more frequent in CCl4-treated animals compared with controls, and increased as fibrosis progressed. Liver norepinephrine and pro-inflammatory cytokines were significantly higher in mice with vs without bacterial-DNA (319.7±120.6 vs 120.7±68.6 pg/g for norepinephrine, 38.4±6.1 vs 29.7±4.2 pg/g for TNF-alpha, 41.8±7.4 vs 28.7±4.3 pg/g for IL-6). Only beta-adrenergic receptor-1 was significantly increased in treated vs control animals (34.6±7.3 vs 12.5±5.3, p = 0.01) and correlated with TNF-alpha, IL-6 and norepinephrine hepatic levels in animals with bacterial-DNA. In the second set of mice, cytokine levels were increased in 6-hydroxidopamine and Nebivolol (beta-adrenergic receptor-1 antagonist) treated mice compared with saline. Butoxamine (beta-adrenergic receptor-2 antagonist) didn’t inhibit liver norepinephrine modulation of pro-inflammatory cytokines. Conclusions Beta-adrenergic receptor-1 mediates liver norepinephrine modulation of the pro-inflammatory response in CCl4-treated mice with bacterial-DNA.

Toll-like receptor polymorphisms compromise the inflammatory response against bacterial antigen translocation in cirrhosis

Bacterial translocation is associated with clinically relevant complications in cirrhosis. We evaluated the effect of toll-like receptor polymorphisms in the soluble response against these episodes. Consecutive patients with cirrhosis and ascitic fluid were distributed by TLR2 rs4696480, TLR4 rs4986790, and TLR9 rs187084 single-nucleotide polymorphisms. Lipoteichoic acid, lipopolyssaccharide, bacterial-DNA, pro-inflammatory cytokines and nitric oxide levels were quantified in serum samples. In vitro response against specific ligands in variant TLR genotypes was evaluated. One hundred and fourteen patients were included. Variant TLR-2, TLR-4 and TLR-9 SNP genotypes were associated with significantly increased serum levels of LTA, LPS and bacterial-DNA. TNF-α, IL-6 and nitric oxide serum levels were significantly decreased in all variant TLR genotyped patients. Cytokine levels were significantly less upregulated in response to specific TLR-ligands in patients with all variant vs wildtype TLR genotypes. Although in vitro gene expression levels of all wildtype and variant TLRs were similar, MyD88 and NFkB were significantly downregulated in cells from TLR-variant genotyped patients in response to their ligands. Variant TLR genotypes are associated with an increased circulating antigen burden and a decreased proinflammatory response in cirrhosis. This immunodeficiency may facilitate bacteria-related complications in cirrhosis and enhance TLR targeting for its management.

Acute Effects of Dipyrone on Renal Function in Patients with Cirrhosis: A Randomized Controlled Trial

Use of non‐steroidal anti‐inflammatory drugs in cirrhosis has been associated with impairment of renal function based on its ability to inhibit the renal production of prostaglandins. Renal effects of dipyrone in patients with cirrhosis have not been evaluated. We aimed to assess the renal effect of therapeutic doses of dipyrone used for short periods of time in patients with cirrhosis. Twenty‐nine patients with cirrhosis were included in an observer‐blind clinical trial. Patients were randomized to receive three times a day oral acetaminophen (500 mg; N = 15) or dipyrone (575 mg; N = 14) for 72 hr. Serum and urine samples were obtained at baseline, 48 and 72 hr, and cystatin C, creatinine, aldosterone, 6‐keto‐Prostaglandin‐F1 alpha and prostaglandin E2 were measured. Cystatin C and creatinine levels remained comparable in patients treated with acetaminophen and dipyrone. Urine and serum prostaglandins concentrations were significantly decreased at 72 hr in patients treated with dipyrone regardless of the status of ascites. One patient with ascites treated with dipyrone required a paracentesis and developed renal insufficiency. We conclude that dipyrone and acetaminophen did not reduce renal function when used for short periods of time (up to 72 hr) in patients with cirrhosis. However, considering that dipyrone lowered renal vasodilator prostaglandins synthesis, acetaminophen appears as the safest choice with respect to kidney function in cirrhosis.

Norfloxacin is more effective than Rifaximin in avoiding bacterial translocation in an animal model of cirrhosis

Norfloxacin administration is useful in preventing bacterial infections in cirrhosis but associated to the generation of resistant species. Rifaximin is known to reach high concentrations in the intestinal lumen without generating relevant resistance in the intestinal flora. Our aim was to compare the effect of Norfloxacin and Rifaximin on intestinal flora composition, bacterial translocation and survival in cirrhotic rats.

Selective intestinal decontamination with norfloxacin enhances a regulatory T cell‐mediated inflammatory control mechanism in cirrhosis

Norfloxacin exerts immunomodulatory effects in cirrhosis beyond its bactericidal activity. We aimed at identifying the role of regulatory T (Treg) cells in the norfloxacin mechanism that compensates the inflammatory environment in cirrhosis.

Treatment with non-selective beta-blockers affects the systemic inflammatory response to bacterial DNA in patients with cirrhosis

The use of non‐selective beta‐blockers has been associated with lower rates of infection and reduced infection‐associated morbidity in patients with cirrhosis. However, it is unknown if these drugs modify the systemic inflammatory response to circulating bacterial DNA.