Albert Tran

M2 Kupffer cells promote M1 Kupffer cell apoptosis: A protective mechanism against alcoholic and nonalcoholic fatty liver disease

Alcoholic and nonalcoholic fatty liver disease (ALD and NAFLD) are the predominant causes of liver‐related mortality in Western countries. We have shown that limiting classical (M1) Kupffer cell (KC) polarization reduces alcohol‐induced liver injury. Herein, we investigated whether favoring alternatively activated M2 KCs may protect against ALD and NAFLD. Ongoing alcohol drinkers and morbidly obese patients, with minimal hepatic injury and steatosis, displayed higher hepatic expression of M2 genes, as compared to patients with more severe liver lesions; individuals with limited liver lesions showed negligible hepatocyte apoptosis but significant macrophage apoptosis. Experiments in mouse models of ALD or NAFLD further showed that BALB/c or resveratrol‐treated mice fed alcohol or a high‐fat diet displayed preponderant M2 KC polarization, M1 KC apoptosis, and resistance to hepatocyte steatosis and apoptosis, as compared to control C57BL6/J mice. In vitro experiments in isolated KC, peritoneal, and Raw264.7 macrophages demonstrated that M1 macrophage apoptosis was promoted by conditioned medium from macrophages polarized into an M2 phenotype by either interleukin (IL)4, resveratrol, or adiponectin. Mechanistically, IL10 released from M2 cells promoted M1 death, and anti‐IL10 antibodies blunted the proapoptic effects of M2‐conditioned media. IL10 secreted by M2 KCs promoted selective M1 death by a mechanism involving activation of arginase in high inducible nitric oxide synthase‐expressing M1 KCs. In alcohol‐exposed mice, neutralization of IL10 impaired M1 apoptosis. Conclusion: These data uncover a novel mechanism regulating the M1/M2 balance that relies on apoptotic effects of M2 KCs towards their M1 counterparts. They suggest that promoting M2‐induced M1 KC apoptosis might prove a relevant strategy to limit alcohol‐ and high fat‐induced inflammation and hepatocyte injury. (Hepatology 2014;58:130–142)

Identification of adipose tissue dendritic cells correlated with obesity-associated insulin-resistance and inducing Th17 responses in mice and patients.

T-cell regulation in adipose tissue provides a link between inflammation and insulin resistance. Because of alterations in adipose tissue T-cell composition in obesity, we aimed to identify the antigen-presenting cells in adipose tissue of obese mice and patients with insulin resistance. Dendritic cells (DCs) and T cells were studied in mice and in two cohorts of obese patients. In lean mice, only CD11c+ DCs were detected in adipose tissue. Adoptive transfer of naive CD4+ T cells in Rag1−/− mice led to a predominant Th1 response in adipose tissue. In contrast, during obesity DCs (human CD11c+CD1c+ and mouse CD11chighF4/80low) accumulated in adipose tissue. CD11chighF4/80low DCs from obese mice induced Th17 differentiation. In patients, the presence of CD11c+CD1c+ DCs correlated with the BMI and with an elevation in Th17 cells. In addition, these DCs led to ex vivo Th17 differentiation. CD1c gene expression further correlated with homeostatic model assessment-insulin resistance in the subcutaneous adipose tissue of obese patients. We show for the first time the presence and accumulation of specific DCs in adipose tissue in mouse and human obesity. These DCs were functional and could be important regulators of adipose tissue inflammation by regulating the switch toward Th17 cell responses in obesity-associated insulin resistance.

Independent Prospective Multicenter Validation of Biochemical Markers (Fibrotest-Actitest) for the Prediction of Liver Fibrosis and Activity in Patients with Chronic Hepatitis C: The Fibropaca Study

OBJECTIVES:Fibrotest (FT) and Actitest (AT) are biochemical markers of fibrosis and activity for use as a non-invasive alternative to liver biopsy in patients with chronic hepatitis C virus (HCV). The aim of this study was to perform an external validation of FT and AT and to study the discordances between FT/AT and liver biopsy in patients with chronic hepatitis C.METHODS:A total of 519 consecutive patients with chronic HCV were prospectively included in five centers, with liver biopsy and biochemical markers taken at the same day. Fifteen patients were excluded because their biopsies could not be interpreted. Diagnostic accuracies were assessed by receiver operating characteristic (ROC) curve analysis.RESULTS:Median biopsy size was 15 mm (range: 2–58), with 9 portal tracts (1–37) and 1 fragment (1–12). 46% (230/504) were classified F2–F4 in fibrosis and 39% A2–A3 in activity. FT area under ROC curve for diagnosis of activity (A2–A3), significant fibrosis (F2–F4), and severe fibrosis (F3–F4) were 0.73 [0.69–0.77], 0.79 [0.75–0.82], and 0.80 [0.76–0.83], respectively. Among the 92 patients (18%) with 2 fibrosis stages of discordance between FT and biopsy, the discordance was attributable to FT in 5% of cases, to biopsy in 4%, and undetermined in 9%.CONCLUSIONS:This prospective independent and multicenter study confirms the diagnostic value of FT and AT found in the princeps study and suggests that FT and AT can be an alternative to biopsy in most patients with chronic HCV.

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.

Accuracy of hyaluronic acid level for predicting liver fibrosis stages in patients with hepatitis C virus.

BackgroundIn patients with chronic hepatitis C virus, liver biopsy is the gold standard for assessing liver disease stage; nevertheless, it is prone to complications, some of them serious. Non-invasive methods have been proposed as surrogate markers for liver fibrosis. It was shown that serum hyaluronic acid (HA) level increases with the development for liver fibrosis. The aim of this study was to evaluate the diagnostic value of HA as well as to determine the HA level cut-off for predicting the presence or absence of fibrosis, severe fibrosis, and cirrhosis.Results405 patients with chronic hepatitis C were prospectively included with biomarker measurement and liver biopsy done the same day: 151 in the training set (only biopsy lengths of 25 mm or more) and 254 in the validation set. For the discrimination of significant fibrosis, severe fibrosis, and cirrhosis in the training set, the areas under curve (AUCs) were 0.75 ± 0.03, 0.82 ± 0.02, and 0.89 ± 0.03, respectively. Absence of significant fibrosis, severe fibrosis, and cirrhosis can be predicted by HA levels of 16, 25, and 50 μg/l, respectively (with negative predictive values of 82%, 89%, and 100%, in the same order). Presence of significant fibrosis, severe fibrosis, and cirrhosis can be predicted by HA levels of 121, 160, and 237 μg/l, respectively (with positive predictive values of 94%, 100%, and 57%, in the same order).ConclusionIn the validation set, HA was accurate in predicting significant fibrosis, severe fibrosis, and cirrhosis with AUCs of 0.73, 0.77, and 0.97, respectively. Moreover, accurate HA level cut-offs were defined for predicting significant fibrosis, severe fibrosis, and cirrhosis. Thus, the study supports that HA level may be clinically useful as a non-invasive marker for liver fibrosis and/or cirrhosis.

HMGA2 is the partner of MDM2 in well-differentiated and dedifferentiated liposarcomas whereas CDK4 belongs to a distinct inconsistent amplicon

Data concerning the fine structure of the 12q13‐15 amplicon which contains MDM2 and CDK4 in well‐differentiated and dedifferentiated liposarcomas (WDLPS/DDLPS) are scarce. We investigated a series of 38 WDLPS/DDLPS using fluorescence in situ hybridization analysis with 17 probes encompassing the 12q13‐15 region. In addition, using quantitative RT‐PCR we studied the expression of MDM2, CDK4, DDIT3 (CHOP/GADD153), DYRK2, HMGA2, TSPAN31 and YEATS4 (GAS41) in 11 cases. We showed that CDK4 (12q14.1) belonged to a distinct amplicon than MDM2 (12q15). There was no continuity in the amplified sequences between MDM2 and CDK4. Moreover, while MDM2 was amplified and overexpressed in all cases, CDK4 was not amplified or overexpressed in 13% of cases. The centromeric border of the CDK4 amplicon was located immediately downstream the 5′ end of DDIT3, a gene known for being involved in myxoid liposarcoma translocations. DDIT3 was amplified in 3 cases and overexpressed in 9 cases. The overexpression of DDIT3 was correlated to the CDK4 amplification and not to its own amplification status. This suggested that the CDK4 amplicon, as well as the overexpression of DDIT3, might be generated by the disruption of a fragile region in 5′ DDIT3. HMGA2 was always amplified and rearranged indicating that it plays a central role in WDLPS/DDLPS. HMGA2 rearrangement frequently resulted in a loss of the 3′ end region that is a binding site for let‐7. We also found a frequent amplification and overexpression of YEATS4, an oncogene that inactivates P53, suggesting that YEATS4 might play an important role together with MDM2 in WDLPS/DDLPS oncogenesis.

Comparison of nine blood tests and transient elastography for liver fibrosis in chronic hepatitis C: the ANRS HCEP-23 study.

BACKGROUND & AIMS Blood tests and transient elastography (Fibroscan™) have been developed as alternatives to liver biopsy. This ANRS HCEP-23 study compared the diagnostic accuracy of nine blood tests and transient elastography (Fibroscan™) to assess liver fibrosis, vs. liver biopsy, in untreated patients with chronic hepatitis C (CHC). METHODS This was a multicentre prospective independent study in 19 French University hospitals of consecutive adult patients having simultaneous liver biopsy, biochemical blood tests (performed in a centralized laboratory) and Fibroscan™. Two experienced pathologists independently reviewed the liver biopsies (mean length=25±8.4 mm). Performance was assessed using ROC curves corrected by Obuchowskis method. RESULTS Fibroscan™ was not interpretable in 113 (22%) patients. In the 382 patients having both blood tests and interpretable Fibroscan™, Fibroscan™ performed similarly to the best blood tests for the diagnosis of significant fibrosis and cirrhosis. Obuchowskis measure showed Fibrometer® (0.86), Fibrotest® (0.84), Hepascore® (0.84), and interpretable Fibroscan™ (0.84) to be the most accurate tests. The combination of Fibrotest®, Fibrometer®, or Hepascore® with Fibroscan™ or Apri increases the percentage of well classified patients from 70-73% to 80-83% for significant fibrosis, but for cirrhosis a combination offers no improvement. For the 436 patients having all the blood tests, AUROCs ranged from 0.82 (Fibrometer®) to 0.75 (Hyaluronate) for significant fibrosis, and from 0.89 (Fibrometer® and Hepascore®) to 0.83 (FIB-4) for cirrhosis. CONCLUSIONS Contrarily to blood tests, performance of Fibroscan™ was reduced due to uninterpretable results. Fibrotest®, interpretable Fibroscan™, Fibrometer®, and Hepascore® perform best and similarly for diagnosis of significant fibrosis and cirrhosis.

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.

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.