scholarly journals Metabolic Signature of Hepatic Fibrosis: From Individual Pathways to Systems Biology

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1423 ◽  
Author(s):  
Ming-Ling Chang ◽  
Sien-Sing Yang

Hepatic fibrosis is a major cause of morbidity and mortality worldwide, as it ultimately leads to cirrhosis, which is estimated to affect up to 2% of the global population. Hepatic fibrosis is confirmed by liver biopsy, and the erroneous nature of this technique necessitates the search for noninvasive alternatives. However, current biomarker algorithms for hepatic fibrosis have many limitations. Given that the liver is the largest organ and a major metabolic hub in the body, probing the metabolic signature of hepatic fibrosis holds promise for the discovery of new markers and therapeutic targets. Regarding individual metabolic pathways, accumulating evidence shows that hepatic fibrosis leads to alterations in carbohydrate metabolism, as aerobic glycolysis is aggravated in activated hepatic stellate cells (HSCs) and the whole fibrotic liver; in amino acid metabolism, as Fischer’s ratio (branched-chain amino acids/aromatic amino acids) decreases in patients with hepatic fibrosis; and in lipid metabolism, as HSCs lose vitamin A-containing lipid droplets during transdifferentiation, and cirrhotic patients have decreased serum lipids. The current review also summarizes recent findings of metabolic alterations relevant to hepatic fibrosis based on systems biology approaches, including transcriptomics, proteomics, and metabolomics in vitro, in animal models and in humans.

1983 ◽  
Vol 6 (5) ◽  
pp. 267-270 ◽  
Author(s):  
Z.Q. Shi ◽  
T.M.S. Chang

In order to clarify wether coated charcoal hemoperfusion is capable of normalizing amino acid disturbances in hepatic coma, in vitro adsorption and in vitro hemoperfusion studies were carried out. We have found that collodion-coated activated charcoal beads preferentially removed much more aromatic acids (AAA) than branched chain amino acids (BCAA). In the in vitro adsorption experiment with 50 μM amino acid standards aqueous solution, 99% of AAAs were removed by charcoal while only 50 to 81% of BCAAs were removed. As the concentration of amino acids in solution was doubled from μM to 100 μM, BCAA removal was halved while about 90% of AAA was still being removed. In vitro hemoperfusion with heparinized blood from hepatic failure rats, the clearance and the removal of AAAs were significantly greater than those of BCAAs. Consequently, the molar ratio of BCAA over AAA was markedly improved from the initial 1.09 to 3.87 after 60 min of hemoperfusion. Thus, we have demonstrated the preferential adsorption of aromatic amino acids by collodion-coated charcoal beads. The correction of BCAA/AAA molar ratio is also demonstrated.


Author(s):  
Jukka Hintikka ◽  
Sanna Lensu ◽  
Elina Mäkinen ◽  
Sira Karvinen ◽  
Marjaana Honkanen ◽  
...  

We have shown that prebiotic xylo-oligosaccharides (XOS) increased beneficial gut microbiota (GM) and prevented high fat diet-induced hepatic steatosis, but the mechanisms associated with these effects are not clear. We studied whether XOS affects adipose tissue inflammation and insulin signaling, and whether the GM and fecal metabolome explain associated patterns. XOS was supplemented or not with high (HFD) or low (LFD) fat diet for 12 weeks in male Wistar rats (n = 10/group). Previously analyzed GM and fecal metabolites were biclustered to reduce data dimensionality and identify interpretable groups of co-occurring genera and metabolites. Based on our findings, biclustering provides a useful algorithmic method for capturing such joint signatures. On the HFD, XOS-supplemented rats showed lower number of adipose tissue crown-like structures, increased phosphorylation of AKT in liver and adipose tissue as well as lower expression of hepatic miRNAs. XOS-supplemented rats had more fecal glycine and less hypoxanthine, isovalerate, branched chain amino acids and aromatic amino acids. Several bacterial genera were associated with the metabolic signatures. In conclusion, the beneficial effects of XOS on hepatic steatosis involved decreased adipose tissue inflammation and likely improved insulin signaling, which were further associated with fecal metabolites and GM.


Author(s):  
Moath Alqaraleh ◽  
Violet Kasabri ◽  
Ibrahim Al-Majali ◽  
Nihad Al-Othman ◽  
Nihad Al-Othman ◽  
...  

Background and aims: Branched chain amino acids (BCAAs) can be tightly connected to metabolism syndrome (MetS) which can be counted as a metabolic indicator in the case of insulin resistance (IR). The aim of this study was to assess the potential role of these acids under oxidative stress. Material and Methods: the in vitro antioxidant activity of BCAAs was assessed using free radical 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging assays. For further check, a qRT-PCR technique was madefor detection the extent of alterations in gene expression of antioxidative enzymes (catalase and glutathione peroxidase (Gpx)) in lipopolysaccharides (LPS(-induced macrophages RAW 264.7 cell line. Additionally, BCAAs antioxidant activity was evaluated based on plasma H2O2 levels and xanthine oxidase (XO) activity in prooxidative LPS-treated mice. Results: Different concentrations of BCAAs affected on DPPH radical scavenging activity but to lesser extent than the ascorbic acid. Besides, BCAAs obviously upregulated the gene expression levels of catalases and Gpx in LPS-modulated macrophage RAW 264.7 cell line. In vivo BCAAs significantly minimized the level of plasma H2O2 as well as the activity of XO activity under oxidative stress. Conclusion: our current findings suggest that BCAAs supplementation may potentially serve as a therapeutic target for treatment of oxidative stress occurs with atherosclerosis, IR-diabetes, MetS and tumorigenesis.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Shu Li ◽  
Lina Wang ◽  
Xiuchuan Yan ◽  
Qinglan Wang ◽  
Yanyan Tao ◽  
...  

The renin-angiotensin system (RAS) plays an important role in hepatic fibrosis. Salvianolic acid B (Sal B), one of the water-soluble components from Radix Salviae miltiorrhizae, has been used to treat hepatic fibrosis, but it is still not clear whether the effect of Sal B is related to angiotensin II (Ang II) signaling pathway. In the present study, we studied Sal B effect on rat liver fibrosis and Ang-II related signaling mediators in dimethylnitrosamine-(DMN-) induced rat fibrotic modelin vivoand Ang-II stimulated hepatic stellate cells (HSCs)in vitro, with perindopril or losartan as control drug, respectively. The results showed that Sal B and perindopril inhibited rat hepatic fibrosis and reduced expression of Ang II receptor type 1 (AT1R) and ERK activation in fibrotic liver. Sal B and losartan also inhibited Ang II-stimulated HSC activation including cell proliferation and expression of type I collagen I (Col-I) andα-smooth muscle actin (α-SMA) productionin vitro, reduced the gene expression of transforming growth factor beta (TGF-β), and downregulated AT1R expression and ERK and c-Jun phosphorylation. In conclusion, our results indicate that Sal B may exert an antihepatic fibrosis effect via downregulating Ang II signaling in HSC activation.


1990 ◽  
Vol 73 (3A) ◽  
pp. NA-NA
Author(s):  
H. Yamada ◽  
Y. Ohta ◽  
I. Chaudhry ◽  
H. Nagashima ◽  
J. Askanazi ◽  
...  

PEDIATRICS ◽  
1963 ◽  
Vol 32 (2) ◽  
pp. 234-238
Author(s):  
Joseph Dancis ◽  
Joel Hutzler ◽  
Mortimer Levitz

The metabolism of the three branched-chain amino acids has been investigated in vitro, using the peripheral leukocyte. The normal leukocyte can transaminate and decarboxylate the three amino acids. These functions are demonstrable at birth. Five cases of maple syrup urine disease (branched-chain ketoaciduria) were studied. The peripheral leukocyte could transaminate the three amino acids, but decarboxylation was greatly reduced or absent. This confirms the site of metabolic block in maple syrup urine disease, and suggests an early and specific approach to diagnosis. Oxidative-decarboxylation of the branched-chain ketoacids involves an enzyme common to all three ketoacids.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Zhanxuan Wu ◽  
Karl Fraser ◽  
Marlena Kruger ◽  
Garth Cooper ◽  
Anne-Thea McGill ◽  
...  

Abstract Objectives Plasma levels of branched-chain amino acids (BCAA) and aromatic amino acids (AAA) phenylalanine (phe) and tyrosine (tyr) have been associated with obesity, insulin resistance and risk of type 2 diabetes. This study aimed to investigate the response of circulating plasma and tissue levels of BCAA and AAA to weight loss, and to correlate the level of these metabolites in plasma and tissue in obese women. Methods 28 obese (mean BMI 46.2 kg/m2) women underwent low energy diet (LED)-induced weight loss (−9.2 ± 4.2 kg) followed by bariatric surgery-induced weight loss (−23.6 ± 2.5 kg). Plasma at baseline (t0), post-LED/pre-surgery (t1) and 6-month post-surgery (t2) as well as biopsies of subcutaneous abdomen adipose tissue (SAfat), superficial thigh adipose tissue (Tfat) and vastus lateralis thigh muscle (Tmuscle) at both t1 and t2 were collected, and profiled using mass spectrometry-based metabolomics approach. Paired t-tests were applied to assess between-timepoint differences, and Pearson correlation used to calculate correlation coefficient of metabolite levels between plasma and tissue. Results Plasma BCAA and AAA were all significantly reduced post-LED at t1 (fold-change of 0.76–0.85 for val, leu, ile, tyr and phe, P < 0.05) and 6-month post-surgery at t2 (fold-change of 0.74–0.85 for val, leu, ile, tyr and phe, P < 0.05) as compared to baseline t0; but not significant between t1 and t2, although trends of decrease were observed. Among the 3 tissue biopsies, only SAfat showed significantly decreased levels of tyr, leu and ile at t2 compared to t1 (fold-change for tyr 0.63, leu 0.66, ile 0.68, P < 0.05). In addition, plasma levels of val and ile were correlated with Tfat levels at both t1 and t2 (r2 = 0.47–0.57), and that of val, ile and leu were correlated with Tmuscle at t1 only (r2 = 0.64–0.67). Conclusions Circulating levels of BCAA and AAA were decreased by weight loss interventions. The decrease following an LED program was sustained after bariatric surgery without further significant decrease. Bariatric surgery also decreased BCAA levels in SAfat; moreover, our data suggested that plasma BCAA levels correlated well with peripheral tissue Tfat and Tmuscle. Funding Sources The New Zealand National Science Challenge High-Value Nutrition program.


2019 ◽  
Vol 51 (Supplement) ◽  
pp. 547
Author(s):  
Mikako Sakamaki-Sunaga ◽  
Kayoko Kamemoto ◽  
Mizuki Yamada ◽  
Tomoka Matsuda ◽  
Hazuki Ogata

2008 ◽  
Vol 190 (18) ◽  
pp. 6134-6147 ◽  
Author(s):  
Shigeo Tojo ◽  
Takenori Satomura ◽  
Kanako Kumamoto ◽  
Kazutake Hirooka ◽  
Yasutaro Fujita

ABSTRACT Branched-chain amino acids are the most abundant amino acids in proteins. The Bacillus subtilis ilv-leu operon is involved in the biosynthesis of branched-chain amino acids. This operon exhibits a RelA-dependent positive stringent response to amino acid starvation. We investigated this positive stringent response upon lysine starvation as well as decoyinine treatment. Deletion analysis involving various lacZ fusions revealed two molecular mechanisms underlying the positive stringent response of ilv-leu, i.e., CodY-dependent and -independent mechanisms. The former is most likely triggered by the decrease in the in vivo concentration of GTP upon lysine starvation, GTP being a corepressor of the CodY protein. So, the GTP decrease derepressed ilv-leu expression through detachment of the CodY protein from its cis elements upstream of the ilv-leu promoter. By means of base substitution and in vitro transcription analyses, the latter (CodY-independent) mechanism was found to comprise the modulation of the transcription initiation frequency, which likely depends on fluctuation of the in vivo RNA polymerase substrate concentrations after stringent treatment, and to involve at least the base species of adenine at the 5′ end of the ilv-leu transcript. As discussed, this mechanism is presumably distinct from that for B. subtilis rrn operons, which involves changes in the in vivo concentration of the initiating GTP.


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