Marie-Christine Saint-Paul

A caspase inhibitor fully protects rats against lethal normothermic liver ischemia by inhibition of liver apoptosis

Apoptosis is activated during the early phase of reperfusion after liver ischemia and after liver transplantation in animals. However, the molecular basis of ischemia‐induced cell death remains poorly understood. In this study we show that hepatocytes from ischemic liver lobes undergo apoptosis after reperfusion. In vivo pretreatment of rats with a specific inhibitor of caspases abrogates the apoptotic response in ischemic liver lobes. Inhibition of apoptosis can be accounted for by total inhibition of caspase activation as assessed in an enzymatic assay and by specific affinity labeling. Treatment with a caspase inhibitor fully protects rats from death induced by ischemia/ reperfusion. These findings indicate that liver injury after ischemia/reperfusion can be prevented by inhibition of caspases. Thus, caspase inhibitors may have important therapeutic implications in liver ischemic diseases and after liver transplantation.—Cursio, R., Gugenheim, J., RicciJ, E., Crenesse, D., Rostagno, P., Maulon, L., Saint‐Paul, M.‐C., Ferrua, B., Auberger, P. A caspase inhibitor fully protects rats against lethal normothermic liver ischemia by inhibition of liver apoptosis. FASEB J. 13, 253–261 (1999)

The inflammatory C-reactive protein is increased in both liver and adipose tissue in severely obese patients independently from metabolic syndrome, Type 2 diabetes, and NASH.

OBJECTIVE:C-Reactive Protein (CRP), a nonspecific marker of inflammation that is moderately elevated in obesity, metabolic syndrome (MS), and type 2 diabetes, has been proposed as a surrogate marker of nonalcoholic steatohepatitis (NASH). Its clinical usefulness in the diagnosis of NASH was evaluated in severely obese patients without or with MS, diabetes, and NASH and the potential roles of the liver and of the adipose tissue in CRP production were characterized.METHODS:Severely obese patients without NASH (without MS [N = 13], with MS [N = 11], or with MS and diabetes [N = 7]) and with NASH (without [N = 8] or with [N = 7] MS) were studied. For each patient, liver and adipose tissue biopsies were collected during a bariatric surgery and were used to determine the CRP gene expression by real-time PCR. The role of interleukin-6 (IL6) and lipopolysaccharide in CRP expression was also evaluated in subcutaneous adipose tissue obtained during cosmetic abdominoplasty.RESULTS:Plasma CRP levels were elevated in severely obese patients independently from the presence or absence of MS, diabetes, or NASH. CRP gene expression was not only increased in livers but also in adipose tissues of obese patients compared with controls subjects. In human adipose tissue, CRP mRNA levels were positively correlated with those of IL-6 and the CRP expression was enhanced in vitro by IL-6 and lipopolysaccharide.CONCLUSION:Plasma CRP levels are not predictive of the diagnosis of NASH in severely obese patients. The liver but also the adipose tissue can produce CRP, a process which could be dependent on IL6. Therefore, both tissues might contribute to the elevated plasma CRP levels found in obesity. In addition, the large amount of body fat may well produce an important part of the circulating CRP, further limiting its clinical usefulness in the evaluation of NASH in severely obese patients.

Mast cells and cellularity of the colonic mucosa correlated with fatigue and depression in irritable bowel syndrome

Background: A subset of patients with irritable bowel syndrome (IBS) have an increased number of mast cells (MCs) in the colonic mucosa. Psychological factors are believed to contribute to the course of IBS. Aims: To examine associations between fatigue, depression and MCs of the colonic mucosa in IBS. Methods: Colonic biopsies were taken from 50 Rome II IBS patients, 21 healthy controls and 11 depressed/fatigued patients without IBS. The cellularity of the lamina propria was determined as the number of inflammatory cells per high power field (hpf) through a 400× microscope. The Fatigue Impact Scale (FIS) and the short form Beck Depression Inventory (BDI) evaluated the severity of fatigue and depression. Results: IBS patients had a significant increase in the cellularity of the lamina propria compared with controls or with depressed patients (mean (SD) 94.5 (48–110) vs 68 (58–82) and 78 (87–90) cells per hpf, p = 0.005 and p = 0.05, respectively), in particular of MCs (9.3 (5.6–11.7) vs 4.0 (2.7–6.8) and 4.3 (2.8–7.8) cells per hpf, p = 0.001 and p = 0.005, respectively). Both the FIS and BDI scores were significantly higher in IBS or in depressed patients than in controls (p<0.001). In IBS, the FIS score correlated significantly with the cellularity of the lamina propria (r = 0.51, p<0.0001) and MCs (r = 0.64, p<0.0001). In IBS, the BDI score correlated significantly with MCs (r = 0.29, p = 0.03). Conclusions: Elevated MCs counts are a key feature of the low-grade inflammatory infiltrate in the caecal mucosa of IBS. Fatigue and depression are associated with mucosal cell counts, in particular MCs, suggesting that psychological factors are associated with the low-grade inflammatory infiltrate in IBS.

Chronic pancreatitis and inflammatory bowel disease: true or coincidental association?

OBJECTIVE:Several cases of pancreatitis have been described during the course of Crohns disease (CD) or ulcerative colitis (UC), but many of them were related to either biliary lithiasis or drug intake. We tried to evaluate the clinical and morphological features of so-called idiopathic pancreatitis associated with inflammatory bowel disease and to define their pathological characteristics.METHODS:Chronic idiopathic pancreatitis was diagnosed on the basis of abnormal pancreatograms suggestive of chronic pancreatitis associated with or without impaired exocrine pancreatic function, or pathological examination in patients undergoing pancreatic resection. We found 6 patients presenting with features of chronic idiopathic pancreatitis and UC and 2 patients with CD seen between 1981 and 1996 in three hospital centers of the south of France. A review of the literature has identified 6 cases of pancreatitis associated with UC and 14 cases of pancreatitis associated with CD based on the above criteria.RESULTS:Hyperamylasemia was not a sensitive test since it was present in 44% and 64% of patients with UC or CD. In UC, pancreatitis was a prior manifestation in 58% of patients. In contrast, the pancreatitis appeared after the onset of CD in 56% of the cases. In patients with UC, pancreatitis were associated with severe disease revealed by pancolitis (42%) and subsequent surgery. Bile duct involvement was more frequent in patients with UC than with CD (58%vs 12%) mostly in the absence of sclerosing cholangitis (16%vs 6%). Weight loss and pancreatic duct stenosis were also more frequent in UC than in CD (41%vs 12% and 50%vs 23%, respectively). Pathological specimens were analyzed in 5 patients and demonstrated the presence of inter- and intralobular fibrosis with marked acinar regression in 3 and the presence of granulomas in 2 patients, both with CD.CONCLUSIONS:Pancreatitis is a rare extraintestinal manifestation of inflammatory bowel disease. Chronic pancreatitis associated with UC differs from that observed in CD by the presence of more frequent bile duct involvement, weight loss, and pancreatic duct stenosis, possibly giving a pseudo-tumor pattern.

Hepatic expression patterns of inflammatory and immune response genes associated with obesity and NASH in morbidly obese patients.

Background Obesity modulates inflammation and activation of immune pathways which can lead to liver complications. We aimed at identifying expression patterns of inflammatory and immune response genes specifically associated with obesity and NASH in the liver of morbidly obese patients. Methodology/Principal Findings Expression of 222 genes was evaluated by quantitative RT-PCR in the liver of morbidly obese patients with histologically normal liver (n = 6), or with severe steatosis without (n = 6) or with NASH (n = 6), and in lean controls (n = 5). Hepatic expression of 58 out of 222 inflammatory and immune response genes was upregulated in NASH patients. The most notable changes occurred in genes encoding chemokines and chemokine receptors involved in leukocyte recruitment, CD and cytokines involved in the T cell activation towards a Th1 phenotype, and immune semaphorins. This regulation seems to be specific for the liver since visceral adipose tissue expression and serum levels of MCP1, IP10, TNFα and IL6 were not modified. Importantly, 47 other genes were already upregulated in histologically normal liver (e.g. CRP, Toll-like receptor (TLR) pathway). Interestingly, serum palmitate, known to activate the TLR pathway, was increased with steatosis. Conclusion/Significance The liver of obese patients without histological abnormalities already displayed a low-grade inflammation and could be more responsive to activators of the TLR pathway. NASH was then characterized by a specific gene signature. These findings help to identify new potential actors of the pathogenesis of NAFLD.

Functional bowel symptoms in quiescent inflammatory bowel diseases: role of epithelial barrier disruption and low-grade inflammation

Objective To determine the role of colonic barrier defects and low-grade inflammation in irritable bowel syndrome (IBS)-like symptoms in quiescent inflammatory bowel disease (IBD). Design Caecal biopsies were collected from 51 IBS, 49 quiescent IBD (31 Crohns disease (CD) and 18 ulcerative colitis (UC)) patients and 27 controls. IBS was assessed using the Rome III criteria and the IBS severity score. Epithelial barrier integrity was evaluated by determining the paracellular permeability of biopsies mounted in Ussing chambers and the mRNA expression of tight junction proteins (ZO-1, α-catenin and occludin). Low-grade inflammation was evaluated by counting cells, including intraepithelial lymphocytes (IELs), eosinophils and mast cells, and by determining the mRNA and protein expression of tumour necrosis factor (TNF)-α in biopsies and culture supernatants. Results IBS-like symptoms were present in 35.4 and 38% of CD and UC patients, respectively. Paracellular permeability was significantly increased in both quiescent IBD with IBS-like symptoms and IBS compared with quiescent IBD without IBS-like symptoms (p<0.01, respectively) or controls (p<0.01, respectively). Significantly lower expression of ZO-1 and α-catenin was detected in IBS and quiescent IBD with IBS-like symptoms. IELs and TNF-α were significantly increased in quiescent IBD with IBS-like symptoms, but not in IBS. Conclusions In quiescent IBD, IBS-like symptoms related to persistent subclinical inflammation associated with increased colonic paracellular permeability. A persistent increase in TNF-α in colonic mucosa may contribute to the epithelial barrier defects associated with abdominal pain in quiescent IBD, but not in IBS. Optimisation of anti-inflammatory therapy may be considered in quiescent IBD with IBS-like symptoms.

Impact of antiretroviral treatment on progression of hepatic fibrosis in HIV/hepatitis C virus co-infected patients.

Background: The impact of immune reconstitution on liver fibrosis in HIV/hepatitis C virus (HCV) patients is unknown. In this case–control study, we investigated the impact of HIV infection on the severity of liver fibrosis and identified related factors. Methods: We studied 116 HIV/HCV patients and 235 HCV only patients all untreated for HCV. Each co-infected patient was matched with two singly-infected patients according to gender, age at contamination and duration of infection. Liver biopsy was analysed using the METAVIR score. Results: Alcohol consumption and route of contamination differed between HCV-infected and HCV/HIV co-infected patients. Among co-infected patients, a F3–F4 Metavir score was significantly more frequent than in mono-infected patients. Co-infected patients with severe fibrosis (F3–F4) had higher transaminase, ferritin levels and lower CD4 T-cell count than patients with none to moderate fibrosis (F0–F2). Although median duration of treatment with nucleoside analogues, non-nucleoside analogues and protease inhibitors were comparable in both groups, the delay between the presumed date of contamination and treatment initiation with highly active antiretroviral therapy (HAART) was significantly longer for patients with severe fibrosis than those with none to moderate fibrosis. Finally, the mean rate of fibrosis progression was significantly slower among patients exposed to HAART. Conclusion: Early antiretroviral therapy in co-infected HIV-HCV patients may slow liver fibrosis progression.

KRAS and BRAF Mutational Status in Primary Colorectal Tumors and Related Metastatic Sites: Biological and Clinical Implications

BackgroundKRAS and BRAF mutations in primary colorectal tumors (PT) are predictive of nonresponse to anti–epidermal growth factor receptor (EGFR) antibodies in patients with metastatic colorectal cancer (mCRC). The question of primary resistance to anti-EGFR treatment as a result of the presence of KRAS or BRAF mutations only in metastases has been raised but not resolved.MethodsWe analyzed the mutational status of KRAS and BRAF in 64 new patients with mCRC and performed a systematic review of published data from 285 patients.ResultsA total of 285 and 95 matched PT/metastases were available for the analysis of the KRAS and the BRAF status, respectively. An identical mutational pattern of KRAS in PT and the matching metastases were reported in all the cases but 14 (5%). In six cases (2%), KRAS was mutated in the PT and wild type in the metastatic site, whereas in eight cases (3%), KRAS was wild type in the PT and mutated in the metastatic site. An identical mutational pattern of BRAF in PT and the matching metastases was reported in all but two cases (3%). In one case (1.5%), BRAF was mutated in the PT and wild type in the metastatic site, whereas in one case (1.5%), BRAF was wild type in the PT and mutated in the metastatic site.ConclusionsThe acquisition by metastases of a KRAS or a BRAF mutation that was not present in the PT is a rare event, occurring in 5% of cases of mCRC. This is not a frequent mechanism of primary resistance to anti-EGFR treatments in mCRC.

Rat liver injury after normothermic ischemia is prevented by a phosphinic matrix metalloproteinase inhibitor

Hepatic ischemia occurs in liver transplantation, hemodynamic or cardiogenic shock, and liver resection associated with trauma or tumor. Ischemia/reperfusion (I/R) injury results in microcirculation failure followed by apoptosis and necrosis. Matrix metalloproteinases (MMPs) are involved in many physiological and pathological processes, but their expression and function during liver I/R remains poorly documented. In this study, we evaluated the expression of nine MMPs and their natural inhibitors, tissue inhibitors of MMPs (TIMPs), in a rat model of liver I/R. Analysis of MMP and TIMP expression show that although most of these genes are not constitutively expressed in the normal liver, they are induced in a specific time‐dependent manner following I/R. Stromelysin‐1, gelatinase B, and collagenase‐3 are induced during the early phase of acute liver injury associated with inflammation and increased necrosis/apoptosis, whereas gelatinase A, membrane type‐MMP, stromelysin‐3, metalloelastase, TIMP‐1, and TIMP‐2 are essentially detectable during the recovery phase of liver injury corresponding to hepatocyte regeneration. This observation suggested that MMPs and TIMPs could play both deleterious and beneficial roles following I/R. We thus tested the effect of a specific phosphinic MMP inhibitor on acute liver I/R injury. Inhibition of MMP activity was shown to significantly decrease liver injury in ischemic/reperfused liver tissue as assessed by histological studies and serum hepatic enzyme levels. We therefore propose that MMP inhibitors may be of clinical relevance in liver‐associated ischemic diseases or after liver transplantation.

Chondrex (YKL-40), a potential new serum fibrosis marker in patients with alcoholic liver disease

Objectives Chondrex (YKL‐40) is a mammalian member of a protein family that includes bacterial chitinases. The pattern of its expression in certain tissues such as human liver or cartilage suggests a function in remodelling or degradation of extracellular matrix. The purpose of this study was to assess whether circulating YKL‐40 might be a serum fibrosis marker in alcoholics. Methods Plasma YKL‐40 was determined in 146 consecutive heavy drinkers (106 men, 40 women; mean age, 49.2 ± 9.0 years). Liver biochemical parameters and serum fibrosis markers such as hyaluronate were also measured. Fibrosis and inflammation in liver biopsy were evaluated using a semi‐quantitative scoring system. Results Plasma YKL‐40 increased in parallel with the severity of fibrosis (P < 0.00001). YKL‐40 also increased in the presence of hepatic inflammation (P < 0.01). Receiver operating characteristic curves of Chondrex revealed that a threshold of 330 μg/E gave a specificity of 88.5%; however, the sensitivity was only 50.8%. Only 11.5% of patients without severe fibrosis displayed a Chondrex plasma level above this threshold. A positive correlation was found between Chondrex and hyaluronate (r = 0.40, P < 0.0001), and a negative correlation was shown between Chondrex and the prothrombin index (r = −0.37, P < 0.0001). Conclusions The severity of liver fibrosis is associated with elevated circulating Chondrex levels. The overlap in YKL‐40 values prevents use of Chondrex in a screening programme. High levels of Chondrex (above 330 μg/E) are predictive of severe liver fibrosis. Increased plasma YKL‐40 may reflect the remodelling of liver fibrosis in alcoholics. Eur J Gastroenterol Hepatol 12:989‐993