Changes in serum cytokine concentration: a morphological study of liver cirrhosis induced by common bile duct ligation in rats

The value of 99mTc-labeled galactosyl human serum albumin single-photon emission computerized tomography/computed tomography on regional liver function assessment and posthepatectomy failure prediction in patients with hilar cholangiocarcinoma

BACKGROUND

The aim was to evaluate the value of Tc-labeled galactosyl human serum albumin (Tc-GSA) with single-photon emission computerized tomography (SPECT) in the preoperative assessment of regional liver function and prediction of posthepatectomy liver failure (PHLF) in patients with hilar cholangiocarcinoma (hCCA).

METHODS

Patients with hCCA who underwent Tc-GSA SPECT/computed tomography (CT) before hepatectomy were included. The liver functional parameters of functional liver density (FLD) and predictive residual index (PRI) were calculated based on Tc-GSA SPECT/CT. PHLF was defined according to the International Study Group of Liver Surgery criteria. Univariate and multivariate analyses were used to analyze the risk factors for PHLF. The prediction of PHLF was calculated using receiver operating characteristic curve.

RESULTS

A total of 34 patients were included, 23 of whom underwent preoperative biliary drainage. FLD was significantly higher in patients with drained lobes than that in patients with undrained lobes (0.615 ± 0.190 versus 0.500 ± 0.211, P < 0.05). Sixteen patients suffered PHLF. The ratio of future remnant to total morphological liver volume, future remnant FLD, and PRI differed significantly in patients with and without PHLF according to univariate analysis. PRI was identified as the only independent factor for prediction of PHLF according to multivariate analysis. With a PRI of 0.78, it was possible to predict PHLF with a sensitivity of 83% and a specificity of 93%.

CONCLUSIONS

Tc-GSA SPECT/CT can accurately assess regional liver function and is better able to predict PHLF than conventional methods in patients with hCCA.

Effects of Myrtus communis extract treatment in bile duct ligated rats

BACKGROUND

The aim of our study was to investigate the antifibrotic and antioxidant effects of Myrtus communis subsp. communis (MC) extract against liver injury and fibrosis occurring in rats with biliary obstruction.

MATERIALS AND METHODS

The rats were randomized into four groups (n = 8). Control group (C), MC-administrated group (MC), the bile duct ligation (BDL), and BDL + MC groups. MC was administered at a dose of 50 mg/kg a day orally for 28 days. In blood samples, total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase levels, tumor necrosis factor-α, and interleukin-1β measurement were measured. Oxidative injury was examined by measuring luminol and lucigenin chemiluminescence, malondialdehyde and glutathione levels, superoxide dismutase and myeloperoxidase activities. Transforming growth factor-beta and hydroxyproline levels were measured for analyzing fibrosis. The hepatic injury was also analyzed microscopically.

RESULTS

Plasma total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor-α, and interleukin-1β levels were found significantly high in the BDL group, while these values significantly decreased in the BDL group treated with MC. On the other hand, the glutathione and superoxide dismutase values significantly decreased in the BDL group compared to the control group but increased markedly in BDL + MC group compared to the BDL group. Malondialdehyde levels, myeloperoxidase activity, tissue luminol, lucigenin, transforming growth factor-beta, and hydroxyproline levels when compared with the control group increased dramatically in the BDL group and reduced the MC + BDL group.

CONCLUSIONS

Our results suggest that MC protects the liver tissues against oxidative damage following BDL via its radical scavenging and antioxidant activities, which appear to involve the inhibition of tissue neutrophil infiltration.

Cholestasis-induced adaptive remodeling of interlobular bile ducts

Cholestasis is a common complication in liver diseases that triggers a proliferative response of the biliary tree. Bile duct ligation (BDL) is a frequently used model of cholestasis in rodents. To determine which changes occur in the three-dimensional (3D) architecture of the interlobular bile duct during cholestasis, we used 3D confocal imaging, surface reconstructions, and automated image quantification covering a period up to 28 days after BDL. We show a highly reproducible sequence of interlobular duct remodeling, where cholangiocyte proliferation initially causes corrugation of the luminal duct surface, leading to an approximately five-fold increase in surface area. This is analogous to the function of villi in the intestine or sulci in the brain, where an expansion of area is achieved within a restricted volume. The increase in surface area is further enhanced by duct branching, branch elongation, and loop formation through self-joining, whereby an initially relatively sparse mesh surrounding the portal vein becomes five-fold denser through elongation, corrugation, and ramification. The number of connections between the bile duct and the lobular bile canalicular network by the canals of Hering decreases proportionally to the increase in bile duct length, suggesting that no novel connections are established. The diameter of the interlobular bile duct remains constant after BDL, a response that is qualitatively distinct from that of large bile ducts, which tend to enlarge their diameters. Therefore, volume enhancement is only due to net elongation of the ducts. Because curvature and tortuosity of the bile duct are unaltered, this enlargement of the biliary tree is caused by branching and not by convolution.

CONCLUSION

BDL causes adaptive remodeling that aims at optimizing the intraluminal surface area by way of corrugation and branching.

A comparison of two common bile duct ligation methods to establish hepatopulmonary syndrome animal models

The major drawback of the current common bile duct ligation (CBDL)-induced hepatopulmonary syndrome (HPS) animal model is the extremely high mortality rate that hinders experimental studies. The purpose of this study was to investigate an improved method of CBDL with the goal of developing a simple and reproducible rat HPS model after a single CBDL treatment. Two groups of male Sprague–Dawley rats underwent separate methods of CBDL: (1) the upper common bile duct ligation (UCBDL) group ( n = 40), in which the first ligature was made near the junction of the hepatic ducts, and the second ligature was made above the entrance of the pancreatic duct; (2) the middle of the common bile duct ligation (MCBDL) group ( n = 40), in which the first ligature was made in the middle of the common bile duct, and the second ligature was made above the entrance of the pancreatic duct. The CBDL-induced HPS rats were evaluated by pulse oximeter, arterial blood analysis, histopathology, and cerebral uptake of intravenous technetium-99m-labeled albumin macroaggregates (which reflects intrapulmonary vascular dilation). The mortality rates of the UCBDL group and the MCBDL group were 42.5% and 77.5%, respectively ( P < 0.05). These results suggest that the UCBDL, a single improved procedure, provides a better method compared to the established HPS model, because of the relatively high success rate and the decreased risk of complications.

The role of vitamin d in primary biliary cirrhosis: possible genetic and cell signaling mechanisms

Primary biliary cirrhosis (PBC) is an immune-mediated chronic inflammatory disease of the liver of unknown etiology. Vitamin D deficiency is highly prevalent in patients with PBC, and many studies have demonstrated the significant effect of calcitriol on liver cell physiology. Vitamin D has antiproliferative and antifibrotic effects on liver fibrosis. Genetic studies have provided an opportunity to determine which proteins link vitamin D to PBC pathology (e.g., the major histocompatibility complex class II molecules, the vitamin D receptor, toll-like receptors, apolipoprotein E, Nramp1, and cytotoxic T lymphocyte antigen-4). Vitamin D also exerts its effect on PBC through cell signaling mechanisms, that is, matrix metalloproteinases, prostaglandins, reactive oxygen species, and the transforming growth factor betas. In conclusion, vitamin D may have a beneficial role in the treatment of PBC. The best form of vitamin D for use in the PBC is calcitriol because it is the active form of vitamin D3 metabolite, and its receptors are present in the sinusoidal endothelial cells, Kupffer cells, and stellate cells of normal livers, as well as in the biliary cell line.

Splanchnic Th(2) and Th(1) cytokine redistribution in microsurgical cholestatic rats

BACKGROUND

Long-term extrahepatic cholestasis in the rat induces ductular proliferation and fibrosis in the liver, portal hypertension, splenomegaly, portosystemic collateral circulation, and ascites. These splanchnic alterations could have an inflammatory pathophysiology.

MATERIAL AND METHODS

We measured serum levels of hepatobiliary injury markers and the acute phase proteins, alpha-1-major acid protein (alpha(1)-MAP) and alpha-1-acid glycoprotein (alpha(1)-GPA) in rats 6 wk after microsurgical extrahepatic cholestasis. We also assayed Th(1) (TNF-alpha and IL-1beta) and Th(2) (IL-4 and IL-10) cytokine levels in the liver, ileum, spleen, and mesenteric lymph complex by enzyme-linked immunosorbent assay (ELISA) techniques. Liver fibrosis was measured by Sirius red stain and by using an image system computer-assisted method and mast cell liver infiltration by Giemsa stain.

RESULTS

The cholestatic rats showed an increase (P<0.001) in serum levels of bile acids, total and direct bilirubin, AST, ALT, AST/ALT index, gamma-GT, alkaline phosphatase, alpha(1)- MAP, alpha(1)-GPA, and LDH (P<0.05) in relation to sham-operated rats. TNF-alpha, IL-1beta, IL-4, and IL-10 increased in the ileum (P<0.01) and mesenteric lymph complex (P<0.001), and decreased in the liver (P<0.001). A marked bile proliferation associated with fibrosis (P<0.001) and mast cell infiltration was also shown in the liver of cholestatic rats.

CONCLUSION

The splanchnic redistribution of cytokines, with an increase of Th(1) and Th(2) production in the small bowel and in the mesenteric lymph complex, supports the key role of inflammatory mechanisms in rats with secondary biliary fibrosis.

Preventive effects of ME3738 on hepatic fibrosis induced by bile duct ligation in rats

AIM

The aim of this study was to examine the preventive effects of ME3738 on hepatic fibrosis induced by bile duct ligation (BDL) in rats.

METHODS

ME3738 (20 mg/day) was administered orally for 21 days immediately after BDL. Fibrosis was assessed by measuring hepatic hydroxyproline (Hyp) content. Activated hepatic stellate cells (HSCs) were assessed by alpha-smooth muscle actin (alpha-SMA) immunostaining. Hepatic thiobarbituric acid-reactive substance (TBARS), 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxy-2-deoxyguanosine (8-OHdG) immunostaining were used to analyze oxidative stress. The gene expressions of collagen-I, transforming growth factor-beta1 (TGF-beta1), tissue inhibitor of metalloproteinases-1 (TIMP-1), interleukin-6 (IL-6) and heme oxygenase-1 (HO-1) in the liver were examined by real-time reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Hepatic Hyp content and the area of hepatic fibrosis in BDL rats treated with ME3738 were reduced by 24% and 39% compared with non-treated BDL rats (hepatic Hyp, 9.40 +/- 2.85 vs. 12.39 +/- 3.91 mg/liver; P = 0.036; area of hepatic fibrosis, 13.1 +/- 3.8 vs. 21.5 +/- 10.9; P = 0.045). Furthermore, alpha-SMA-positive cells were significantly reduced by 40% (22.3 +/- 14.8 vs. 37.6 +/- 14.2; P = 0.011), collagen-I mRNA by 83% (6.5 +/- 2.2 vs. 38.3 +/- 9.1; P = 0.002), HO-1 mRNA by 58% (4.13 +/- 1.22 vs. 9.73 +/- 1.80; P = 0.018) and hepatic HO-1 content by 26% (2.13 +/- 0.80 vs. 2.87 +/- 0.19; P = 0.01) following ME3738 treatment. The hepatic expression of TBARS, 4-HNE, 8-OHdG and mRNA levels of TGF-beta1, TIMP-1 and IL-6 in the liver were unchanged by ME3738 treatment.

CONCLUSION

Oral ME3738 administration may prevent the progression of hepatic fibrosis in BDL rats through suppression of the activation and collagen synthesis of HSC and, in part, oxidative stress. ME3738 has potential as a therapeutic drug for cholestatic liver fibrosis.

Relationship between transforming growth factor β1 and anti-fibrotic effect of interleukin-10

AIM: To study the effect of interleukin-10 (IL-10) on the expression of transforming growth factor β1 (TGF-β1) in hepatic fibrosis rats and the anti-fibrotic role of exo-genous IL-10.

METHODS: Hepatic fibrosis was induced by carbon tetrachloride administered (CCl₄) intraperitoneally. The experiment was performed in two stages. In the first stage, 60 SD rats were divided randomly into normal control group 1(GN₁, n = 8), hepatic fibrosis group(GC, n = 28)and IL-10 intervened group(GI, n = 24). At the beginning of the 7^th and 11^th wk, hepatic stellate cells (HSCs) were isolated, reverse transcription-polymerase chain reation (RT-PCR) and immunocytochemistry were performed to detect the expression of TGF-β1 in HSCs. Histological examination was used to determine the degree of hepatic fibrosis. In the second stage, 47 SD rats were divided randomly into normal control group 2(GN₂, n = 6)and CCl₄ group(GZ, n = 41). At the end of the 9th week, rats in GZ group were allocated randomly into model group(GM, n = 9), IL-10 treatment group(GT, n = 9)and recovered group(GR, n = 9). At the end of the 12^th week, all rats were sacrificed. RT-PCR and immunohistochemistry were performed to detect the expression of TGF-β1 in liver tissue. ELISA was used to assay serum TGF-β1 levels.

RESULTS: Hepatic fibrosis developed in rats with the increase of the injection frequency of CCl₄. In the first stage, hepatic fibrosis developed and HSCs were isolated successfully. At the 7^th and 11^th week, TGF-β1 mRNA in GC group increased significantly compared with that in GN₁(P = 0.001/0.042)and GI groups(P = 0.001/0.007), whereas there was no significant difference between the two groups. The levels of TGF-β1 at the beginning of the 7^th wk was higher than that of the 11^th wk(P = 0.049). Immunocytochemistry results of TGF-β1 were consistent with the above findings. In the second stage, TGF-β1 increased significantly in GM group compared to GN₂. After treatment with IL-10, TGF-β1 declined obviously. The expression of TGF-β1 decreased in GR group but was still higher than that in GT group.

CONCLUSION: The levels of TGF-β1 are increased in hepatic fibrosis rats and decreased after treatment with exogenous IL-10. IL-10 may play an anti-fibrotic role by suppressing TGF-β1 expression.

Simultaneous Measurement of 25 Inflammatory Markers and Neurotrophins in Neonatal Dried Blood Spots by Immunoassay with xMAP Technology

Background: Inflammatory reactions and other events in early life may be part of the etiology of late-onset diseases, including cerebral palsy, autism, and type 1 diabetes. Most neonatal screening programs for congenital disorders are based on analysis of dried blood spot samples (DBSS), and stored residual DBSS constitute a valuable resource for research into the etiology of these diseases. The small amount of blood available, however, limits the number of analytes that can be determined by traditional immunoassay methodologies.

Methods: We used new multiplexed sandwich immunoassays based on flowmetric Luminex® xMAP technology to measure inflammatory markers and neutrophins in DBSS.

Results: The high-capacity 25-plex multianalyte method measured 23 inflammatory and trophic cytokines, triggering receptor expressed on myeloid cells-1 (TREM-1), and C-reactive protein in two 3.2-mm punches from DBSS. It also measured 26 cytokines and TREM-1 in serum. Standards Recovery in the 25-plex method were 90%–161% (mean, 105%). The low end of the working range for all 25 analytes covered concentrations found in DBSS from healthy newborns. Mean recovery of exogenous analytes added at physiologic concentrations in DBSS models was 174%, mean intra- and interassay CVs were 6.2% and 16%, respectively, and the mean correlation between added and measured analytes was r2 = 0.91. In DBSS routinely collected on days 5–7 from 8 newborns with documented inflammatory reactions at birth, the method detected significantly changed concentrations of inflammatory cytokines. Measurements on DBSS stored at −24 °C for &gt;20 years showed that most cytokines are detectable in equal concentrations over time.

Conclusions: The method can reliably measure 25 inflammatory markers and growth factors in DBSS. It has a large potential for high-capacity analysis of DBSS in epidemiologic case–control studies and, with further refinements, in neonatal screening.