“Hepatic toxicity by methotrexate with weekly single doses associated with folic acid in rheumatoid and psoriatic arthritis. What is its real frequency?”

Introduction and Objectives: Liver injury caused by methotrexate (MTX) has mostly been investigated without applying criteria for the assessment of causality of drug induced liver injury (DILI). Hence, the existence of DILI by MTX in many cases is debatable. This study aimed to describe the frequency and characteristics of liver injury caused by MTX, applying DILI diagnostic criteria. Material and methods: Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients who were treated with MTX in association with folic acid were included. Serial determinations of alanine amino transferase (ALT) and aspartate amino transferase (AST) were performed. The Roussel Uclaf Causality Assessment Method (RUCAM) was applied in cases of increases of ALT/AST over 1.5 upper limit of normal. Liver biopsy was considered when the total cumulative dosage (TCD) of MTX was ≥3.5 g. Results: A total of 43 patients were analyzed (median follow up 32 (range: 1–48) months; 3.33 ALT/AST determinations per year). Five subjects presented an increase of ALT/AST. All presented a RUCAM score for MTX ≤ 2 (improbable). Three had a RUCAM score for non-steroidal anti-inflammatory drugs ≥7 (probable) and two patients presented non-alcoholic fatty liver disease. Five patients with no other cause for liver disease consented to liver biopsy (TCD MTX: median 5.1; range: 3.5–7.4 g). No significant fibrosis or steatosis was evident on histology. Conclusions: No biochemical or significant histological liver toxicity for MTX was demonstrated when applying causality criteria for DILI. More studies with this methodology are necessary in order to improve the assessment of its frequency

Abrogation of hepatocyte apoptosis and early appearance of liver dysplasia in ethanol-fed p53-deficient mice

Ethanol consumption represents a major risk factor for cancer development, and a significant fraction of hepatocarcinomas arises in alcoholic liver cirrhosis. Increasing evidence indicates that ethanol acts as a tumor promoter on genetically initiated cells, by increasing the intracellular concentration of reactive oxygen species and promoting tissue necrosis/regeneration and cell proliferation. The tumor suppressor p53 restrains the expansion of carcinogen-initiated cells by inducing cell cycle arrest and apoptosis; accordingly, p53-deficient mice develop spontaneous and chemically induced neoplasms at a much higher frequency than normal mice. In normal mice exposed to a subacute (3 weeks) ethanol intoxication, a significant increase in the number of apoptotic hepatocytes was observed in concomitance with the up-regulation of the mitochondrial superoxide scavenger MnSOD, a reliable indicator of oxidative stress. Cell death occurred in the absence of liver inflammation and necrosis. Ethanol-induced hepatocyte apoptosis was completely abrogated in the p53 null background, suggesting that the tumor suppressor is necessary for hepatocyte death by ethanol. Accordingly, p53 -/- MEF were, unlike wild type cells, completely insensitive up to 0.5 M ethanol in the culture medium. Strikingly, marked and widespread signs of dysplasia, with nuclear pleomorphisms and initial loss of normal architecture, heralding malignant transformation, were scored in all the mutant mice exposed to ethanol, but not in the control-fed littermates nor in ethanol-fed normal mice. These observations suggest that p53-dependent apoptosis restrains the tumorigenic effect of ethanol on liver cells, in agreement with the frequent loss of p53 function in HCC, and reveal an unexpected carcinogenic potential of alcohol which appears to be independent from the induction of cirrhosis and hepatocyte regeneration.Fil: Pani, Giovambattista. Università Cattolica del Sacro Cuore; ItaliaFil: Fusco, Salvatore. Università Cattolica del Sacro Cuore; ItaliaFil: Colavitti, Renata. Università Cattolica del Sacro Cuore; ItaliaFil: Borrello, Silvia. Università Cattolica del Sacro Cuore; ItaliaFil: Maggiano, Nicola. Università Cattolica del Sacro Cuore; ItaliaFil: Cravero, Amerys A.M.. Universidad de Buenos Aires; ArgentinaFil: Farré, Stella Maris. Universidad de Buenos Aires; ArgentinaFil: Galeotti, Tommaso. Università Cattolica del Sacro Cuore; ItaliaFil: Koch, Osvaldo Raul. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Role of the life span determinant P66(shcA) in ethanol-induced liver damage

Mice lacking the 66 kDa isoform of the adapter molecule shcA (p66(shcA)) display increased resistance to oxidative stress and delayed aging. In cultured cell lines, p66 promotes formation of Reactive Oxygen Species (ROS) in mitochondria, and apoptotic cell death in response to a variety of pro-oxidant noxious stimuli. As mitochondrial ROS and oxidative cell damage are clearly involved in alcohol-induced pathology, we hypothesized that p66 may also have a role in ethanol. In vivo, changes observed in p66+/+ mice after 6-week exposure to ethanol in the drinking water, including elevated serum alanine aminotransferase (ALT), liver swelling and evident liver steatosis, were significantly attenuated in p66-/- mutant mice. Biochemical analysis of liver tissues revealed induction of the p66 protein by ethanol, whereas p66-deficient livers responded to alcohol with a significant upregulation of the mitochondrial antioxidant enzyme MnSOD, nearly absent in control mice. Evidence of an inverse correlation between expression level of p66 and protection from alcohol-induced oxidative stress was also confirmed in vitro in primary hepatocytes and in HepG2-E47 cells, an ethanol-responsive hepatoma cell line. In fact, MnSOD upregulation by exposure to ethanol in vitro was much more pronounced in p66KO versus wild-type isolated liver cells, and blunted in HepG2 cells overexpressing p66shc. p66 overexpression also prevented the activation of a luciferase reporter gene controlled by the SOD2 promoter, indicating that p66 repression of MnSOD operates at a transcriptional level. Finally, p66 generated ROS in HepG2 cells and potentiated oxidative stress and mitochondrial depolarization by ethanol. Taken together, the above observations clearly indicate a role for p66 in alcohol-induced cell damage, likely via a cell-autonomous mechanism involving reduced expression of antioxidant defenses and mitochondrial dysfunction