Animal models of obstructive cholestasis and ischemia/reperfusion damage have revealed the functional heterogeneity of liver lobes. This study evaluates this heterogeneity in nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) rat models. Twelve-week-old Obese and Lean male Zucker rats were used for NAFLD. Eight-week-old male Wistar rats fed with 8-week methionine-choline-deficient (MCD) diet and relative control diet were used for NASH. Gelatinase (MMP-2; MMP-9) activity and protein levels, tissue inhibitors of metalloproteinase (TIMPs), reactive oxygen species (ROS), and thiobarbituric acid-reactive substances (TBARS) were evaluated in the left (LL), median (ML), and right liver (RL) lobes. Serum hepatic enzymes and TNF-alpha were assessed. An increase in gelatinase activity in the NASH model occurred in RL compared with ML. TIMP-1 and TIMP-2 displayed the same trend in RL as ML and LL. Control diet RL showed higher MMP-9 activity compared with ML and LL. No significant lobar differences in MMP-2 activity were detected in the NAFLD model. MMP-9 activity was not detectable in Zucker rats. TIMP-1 was lower in LL when compared with ML while no lobar differences were detectable for TIMP-2 in either Obese or Lean Zucker rats. Control diet rats exhibited higher ROS formation in LL versus RL. Significant increases in TBARS levels were observed in LL versus ML and RL in control and MCD rats. The same trend for ROS and TBARS was found in Obese and Lean Zucker rats. An increased serum TNF-alpha occurred in MCD rats. A lobar difference was detected for MMPs, TIMPs, ROS, and TBARS in both MCD and Zucker rats. Higher MMP activation in RL and higher oxidative stress in the LL, compared with the other lobes studied, supports growing evidence for functional heterogeneity among the liver lobes occurring certainly in both NAFLD and NASH rats.

Background and Aims: We have previously shown in a model of hepatic ischaemia/reperfusion injury that the farnesoid X receptor (FXR) agonist obeticholic acid (OCA) restores reversion‐inducing‐cysteine‐rich protein with Kazal motifs (RECK), an inverse modulator of metalloproteases (MMPs) and inhibitor of the sheddases ADAM10 and ADAM17 involved in inflammation and fibrogenesis. Here, the effects of FXR agonists OCA and INT‐787 on hepatic levels of RECK, MMPs, ADAM10 and ADAM17 were compared in a diet‐induced ob/ob mouse model of non‐alcoholic steatohepatitis (NASH).Methods: Lep ob/ob NASH mice fed a high‐fat diet (HFD) or control diet (CD) for 9 weeks (wks) were treated with OCA or INT‐787 0.05% dosed via HFD admixture (30 mg/kg/day) or HFD for further 12 wks. Serum alanine transaminase (ALT) and inflammatory cytokines, liver RECK, MMP‐2 and MMP‐9 activity as well as ADAM10, ADAM17, collagen deposition (Sirius red), hepatic stellate cell activation (α‐SMA) and pCK⁺ reactive biliary cells were quantified.Results: Only INT‐787 significantly reduced serum ALT, IL‐1β and TGF‐β. A downregulation of RECK expression and protein levels observed in HFD groups (at 9 and 21 wks) was counteracted by both OCA and INT‐787. HFD induced a significant increase in liver MMP‐2 and MMP‐9; OCA administration reduced both MMP‐2 and MMP‐9 while INT‐787 markedly reduced MMP‐2 expression. OCA and INT‐787 reduced both ADAM10 and ADAM17 expression and number of pCK⁺ cells. INT‐787 was superior to OCA in decreasing collagen deposition and α‐SMA levels.Conclusion: INT‐787 is superior to OCA in controlling specific cell types and clinically relevant anti‐inflammatory and antifibrotic molecular mechanisms in NASH.

We investigated changes in fatty acid desaturases, D5D, D6D, D9-16D and D9-18D, and their relationship with oxidative stress, matrix metalloproteinases (MMPs) and serum TNF-alpha in two rat models of non-alcoholic fatty liver disease NAFLD. Eight-week-old male Wistar rats fed for 3 weeks with methionine-choline–deficient (MCD) diet and eleven-week-old Obese male Zucker rats were used. Serum levels of hepatic enzymes and TNF-alpha were quantified. Hepatic oxidative stress (ROS, TBARS and GSH content) and MMP-2 and MMP-9 (protein expression and activity) were evaluated. Liver fatty acid profiling, performed by GC-MS, was used for the quantification of desaturase activities. Higher D5D and D9-16D were found in Obese Zucker rats as well as an increase in D9-18D in MCD rats. D6D was found only in MCD rats. A negative correlation between D5D and D9-16D versus TBARS, ROS and TNF-alpha and a positive correlation with GSH were shown in fatty livers besides a positive correlation between D9-18D versus TBARS, ROS and TNF-alpha and a negative correlation with GSH. A positive correlation between D5D or D9-16D or D9-18D versus protein expression and the activity of MMP-2 were found. NAFLD animal models showed comparable serum enzymes. These results reinforce and extend findings on the identification of therapeutic targets able to counteract NAFLD disorder.

We evaluate the effects of the methionine-choline-deficient (MCD) diet on serum and hepatic zinc (Zn) and iron (Fe) and their relationships with matrix metalloproteinases (MMPs) and their modulators (TIMPs and RECK) as well as hepatic fatty acids using male Wistar rats fed 2-, 4- and 8-week MCD diets. Serum and hepatic Zn decrease after an 8-week MCD diet. Serum Fe increases after an 8-week MCD diet and the same occurs for hepatic Fe. An increase in hepatic MMP activity, associated with a decrease in RECK and TIMPs, is found in the MCD 8-week group. Liver Fe shows a positive correlation versus MMPs and RECK, and an inverse correlation versus TIMPs. A positive correlation is found comparing liver Zn with stearic, vaccenic and arachidonic acids, and an inverse correlation is found with linolenic and docosatetraenoic acids. An opposite trend is found between liver Fe versus these fatty acids. During NAFLD progression from steatosis to steatohepatitis, MCD rats exhibit an increase in Zn and a decrease in Fe levels both in serum and tissue associated with alterations in hepatic MMPs and their inhibitors, and fatty acids. The correlations detected between Zn and Fe versus extracellular matrix modulators and fatty acids support their potential role as therapeutic targets.

The beneficial effects of soluble fibers on carbohydrate metabolism are well documented. In this regard, we tested an arabinoxylan-enriched white bread flour, obtained by a patented process by which the bran extracted from the milling process is enzymatically hydrolyzed in order to separate the soluble fraction fiber from the insoluble fiber. We recruited 24 healthy normoglycemic volunteers [Age 34–61 ± 12.5 y; Body Mass Index (BMI) 22.1 ± 2.5 kg/m²; Waist circumference (WC) 84.43 ± 8.0 cm; Fat Mass (FM) 22.7 ± 8.0%] attending the Dietetics Outpatient Clinic of the Internal Medicine Department at IRCCS Policlinico S. Matteo Foundation, University of Pavia, Pavia, Italy. Subjects acutely consumed arabinoxylan-enriched white bread (weight: 100 g) or isoenergetic control breads, in a double-blind crossover study design. Plasma glucose levels were measured just before bread administration and 30 minutes afterwards. The 30-minute peak postprandial glucose concentrations after arabinoxylan-enriched meals were significantly lower than after the control meal (107±4.6 mg/dL vs. 121 ± 5.2 mg/dL; p < 0.05). The here-reported results show how postprandial glucose responses were improved by ingestion of the arabinoxylan-enriched meal. Further studies are needed to clarify whether daily consumption of arabinoxylan-enriched bread will benefit patients with type 2 diabetes mellitus.

We investigated the effects of obstructive cholestasis in different hepatic lobes by evaluating asymmetric dimethylarginine (ADMA) (a nitric oxide synthase inhibitor), protein methyltransferase (PRMT) and dimethylarginine dimethylaminohydrolase (DDAH) (enzymes involved, resp., in its synthesis and degradation), the cationic transporter (CAT), and metalloproteinase (MMP) activity. Sixteen male Wistar rats underwent a 3-day cholestasis by common bile duct ligation (BDL) or sham operation. Blood samples and hepatic biopsies from left lobe (LL), median lobe (ML), and right lobe (RL) were collected. Serum hepatic enzymes, tissue ADMA, DDAH activity, CAT-2 protein, mRNA expression of DDAH and PRMT, and MMP-2 and MMP-9 activity were monitored. Cholestasis was confirmed by altered serum hepatic enzymes. Higher levels of tissue ADMA were detected in RL and ML as compared with LL. PRMT mRNA expression and DDAH activity did not differ among the lobes after BDL. CAT-2 levels are higher in the RL and ML in the sham-operated group. Higher activity in MMP-2 and MMP-9 was found in RL. In conclusion, after cholestasis an increase in hepatic ADMA in RL and ML was detected as well as tissue MMP-2 and MMP-9 activation in RL, supporting the evidence of functional heterogeneity among the liver lobes also occurring in an obstructive cholestasis model.