High fat induced insulin resistance: the emerging role of hepatokines

Introduction: A link between serum hepatokine levels (proteins produced by the liver and acting distantly) and insulin resistance in type 2 diabetes has been recently suggested. Here, we wanted to explore the liver expression of several hepatokines at the initiation of a high fat diet in mice, as well as their relation with liver macrophage (Kupffer cell) activation. Material and methods: Male mice of 5 weeks of age were fed a normal diet (ND) or a high fat diet (HFD) for 3 days, known to induce steatosis and insulin resistance. A preventive Kupffer cell (KC) depletion was obtained by intravenous injection of clodronate loaded liposomes and compared with PBS liposomes. The mRNA expression of hepatokines (selenoprotein-P, fetuin-A, fibroblast growth factor 21, angiopoietin-like protein 3) was evaluated by RT-PCR on liver tissue. Results: Short term HFD induced steatosis, KC activation and insulin resistance with a significant increased expression of selenoprotein P (1.6 fold, p<0.001), fetuin-A (1.7 fold, p<0.01) and fibroblast growth factor 21 (9 fold, p<0.01). However, the liver expression of angiopoietin-like protein 3 remains unchanged under short term HFD. Kupffer cell depletion in this setting did not reduce hepatic steatosis but significantly ameliorated insulin sensitivity proved by clamp studies. This amelioration in insulin sensitivity in KC-depleted mice was associated with a significant decrease in fetuin A mRNA expression (0.7 fold, p<0.001) compared to animals with KC. Interestingly, while selectively depleting liver macrophages without affecting adipose tissue macrophage infiltration, intravenous clodronate injection was associated with a significant reduction in epididymal adipose tissue expansion compared to PBS injection (1.1% of body weight versus 1.6% of body weight, p<0.001), suggesting a role of liver-derived products in peripheral tissue alterations associated with obesity. Conclusions: We demonstrate liver hepatokine overexpression at the initiation of HFD feeding, concurrent with hepatic steatosis and insulin resistance. Targeting KC in this setting improved insulin sensitivity and was associated with a decreased adiposity and a reduced liver fetuin A expression. The impact of this hepatokine on adipose tissue metabolism needs to be confirmed and the search for pathogenic liver-derived factors in obesity associated disorders intensified

Computed tomography derived liver volume: a prognostic factor in decompensated alcoholic cirrhosis?

Introduction: Decompensated alcoholic liver disease (ALD) causes high morbidity and mortality. Factors associated with a poor clinical evolution, as well as the impact of liver atrophy linked with cirrhosis are poorly determined. The goal of this study is to explore the link between the liver volumetry calculated by computed tomography (CT) and the evolution of liver insufficiency in patients admitted for decompensated ALD. Materials and methods: Non-abstinent patients with acute decompensation of ALD (increase in serum bilirubin and deterioration of liver function) from a prospective study were included. This trial did not evidence any benefice of cellular therapy during the 3 months of follow up (Spahr L et al. Autologous bone marrow stem cell transplantation versus standard of care in patients with decompensated alcoholic liver disease: interim analysis of a RCT. Hepatology 2011;54:A62). Liver volumes evaluated by CT performed rapidly after patient admission were compared to further evolution of hepatic insufficiency, irrespective of treatment allocation. We defined patients with a ≥ 3 points decrease in MELD compared to baseline value as “improvers”, and those with less than 3 points decrease in MELD as “non-improvers”. Results: Fifty-eight patients were included. At admission, mean MELD score was 20.6 points. All patients had cirrhosis. Biopsy proven alcoholic steatohepatitis was diagnosed in 81% of cases. Patients with severe steatohepatitis (Maddrey score ≥ 32) were treated by steroids (66 %). 34 patients (59%) with a good evolution at 3 months (decrease in MELD score of 3 points or more) were classified as improvers meanwhile 24 patients (41%) were classified as non-improvers. Patients’ characteristics at admission depending on the 3 month evolution are reported in this table. Parameter Improvers n=34 Non-improvers n=24 P Age (years) 54 [35-63] 55 [44-67] 0.11 Hepatovenous pressure gradient (mmHg) 19.2 ± 2.7 19.2 ± 4.1 0.25 MELD score 20.7 ± 5.9 20.6 ± 3.3 0.96 Albumin (g/l) 22.2 ± 4.4 22.4 ± 6.7 0.41 Steroid treatment (%) 67.6 62.5 0.68 Cellular therapy (%) 52.9 41.7 0.39 Liver volume (cm3) 2389 ± 998 1646 ± 489 0.0005 Ratio liver volume-body weight (%) 3.2 ± 1.5 2.2 ± 1.0 0.002 Conclusion: This study highlights the link between the severity of hepatic atrophy associated with cirrhosis and the prognosis in case of liver decompensation. Indeed, in patients with decompensated ALD, a low liver volume evaluated by CT is associated with a bad evolution of hepatic function evaluated by MELD score

Liver cell proliferation determines MELD score improvement in decompensated alcoholic liver disease.

Introduction: The prognostic significance of liver progenitor cell (LPC) and macrophage expansion in the regeneration of decompensated alcoholic liver disease (ALD) remains ill defined. In a well-characterized population of patients with acutely decompensated ALD (Spahr L. et al. Hepatology 2011, A62), we analysed macrophage infiltration, proliferative LPC and differential expression of hepatic genes at baseline in relation to outcome at 3 months follow up. Materials and methods: Fifty-eight patients (MELD 20) were included. Liver biopsy at inclusion was used for (1) immunohistological analysis of proliferative LPC (MIB1+/CK7+), proliferative hepatocytes (MIB1+/CK7- parenchymal cells), morphometric analysis of macrophage infiltration (CD68) and LPC expansion (CK7), and (2) transcriptome profiling using Affymetrix GeneChip Human arrays. Serum markers of regeneration (cytokines and growth factors) were measured by immunoassays. A ≥ 3 points decrease in MELD at 3 months as compared to baseline defined the improvers. Fifteen abstinent cirrhotics served as controls. CD68 and SPINK3 mRNA expressions were determined in various mice models of liver injury. Results: At baseline, patients with decompensated ALD presented a significant expansion of CD68+ macrophages and CK7+ cells compared to abstinent cirrhotics. Patients who will improve (n=34) were characterized at baseline by a higher number of CK7+/MIB1+ cells (1.9 ± 1.5 versus 0.9 ± 0.9 cells/field, p<0.01), MIB1+ hepatocytes (4.1 ± 3.6 versus 1.8 ± 1.4 cells/field, p<0.01), an increased expansion of liver macrophages (4.4% versus 3.3% of surface area, p<0.05) and a higher level of serum HGF (p<0.05), compared to those who will not (n=24). Transcriptome analysis revealed that the first pathways upregulated in improvers were related to cell cycle and a 7-fold increase of liver serine peptidase inhibitor Kazal type I (SPINK1) compared with non-improvers (p=0.005). SPINK1 liver expression positively correlated with CD68 (r=0.46) and cyclinE1 (r=0.6). In mice, a 20-fold increase in liver SPINK3 expression, the homolog of human SPINK1, was evidenced following partial hepatectomy, concurrent with hepatocyte proliferation. Conclusions: Baseline markers of liver macrophages and liver cell proliferation predict the clinical outcome in decompensated ALD. This study reveals an unexpected implication of SPINK1, an acute phase reactant, in liver regeneration and human ALD