Early hepatic proteomic signatures reveal metabolic changes in high-fat-induced obesity in rats.

The prevalence of diet-related obesity is increasing dramatically worldwide, making it important to understand the associated metabolic alterations in the liver. It is well known that obesity is a multifactorial condition that is the result of complex integration between many gene expressions and dietary factors. Obesity alone or in conjunction with other chronic diseases such as diabetes and insulin resistance causes many health problems and is considered a major risk factor for developing non-alcoholic steatohepatitis (NASH) and cirrhosis. In this study, we aimed to understand the molecular mechanisms underlying early hepatic changes in the pathophysiology of high-fat diet (HFD)-induced abdominal obesity in rats. Hepatic protein profiles of normal diet and HFD-induced obesity for 24 weeks were analysed using two-dimensional differential gel electrophoresis (DIGE) and protein identification by MS. Fifty-two proteins were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), and computer-assisted DIGE image software analysis showed that eighteen major proteins were significantly differentially expressed between comparable groups, with 2·0­4·0-fold change/more (P < 0·01). These proteins are regulated in response to a HFD, and differentially expressed proteins are involved in key metabolic pathways such as lipid metabolism, energy metabolism, detoxification, urea cycle and hepatic Ca homoeostasis. In addition, Western blot and immunohistochemistry of liver-specific arginase-1 (Arg-1) showed significant increased expression in the liver of high-fat-fed rats (P < 0·01). Further, Arg-1 expression was correlated with NASH patients with obesity-related fibrosis (F0­F4). It is concluded that high-fat content may affect changes in liver pathways and may be a therapeutic target for obesity-related liver disease. Arg-1 expressions may be a potential pathological marker for assessing the progression of the disease.

Biomolecular map of albumin identifies signatures of severity and early mortality in acute liver failure.

BACKGROUND & AIMS: Acute liver failure (ALF) is associated with high mortality. Alterations in albumin structure and function have been shown to correlate with outcomes in cirrhosis. We undertook a biomolecular analysis of albumin to determine its correlation with hepatocellular injury and early mortality in ALF. METHODS: Altogether, 225 participants (200 patients with ALF and 25 healthy controls [HC]) were enrolled. Albumin was purified from the baseline plasma of the training cohort (ALF, n = 40; survivors, n = 8; non-survivors, n = 32; and HC, n = 5); analysed for modifications, functionality, and bound multi-omics signatures; and validated in a test cohort (ALF, n = 160; survivors, n = 53; non-survivors, n = 107; and HC, n = 20). RESULTS: In patients with ALF, albumin is more oxidised and glycosylated with a distinct multi-omics profile than that in HC, more so in non-survivors (p <0.05). In non-survivors, albumin was more often bound (p <0.05, false discovery rate <0.01) to proteins associated with inflammation, advanced glycation end product, metabolites linked to arginine, proline metabolism, bile acid, and mitochondrial breakdown products. Increased bacterial taxa (Listeria, Clostridium, etc.) correlated with lipids (triglycerides [4:0/12:0/12:0] and phosphatidylserine [39:0]) and metabolites (porphobilinogen and nicotinic acid) in non-survivors (r2 >0.7). Multi-omics signature-based probability of detection for non-survival was >90% and showed direct correlation with albumin functionality and clinical parameters (r2 >0.85). Probability-of-detection metabolites built on the top five metabolites, namely, nicotinic acid, l-acetyl carnitine, l-carnitine, pregnenolone sulfate, and N-(3-hydroxybutanoyl)-l-homoserine lactone, showed diagnostic accuracy of 98% (AUC 0.98, 95% CI 0.95-1.0) and distinguish patients with ALF predisposed to early mortality (log-rank <0.05). On validation using high-resolution mass spectrometry and five machine learning algorithms in test cohort 1 (plasma and paired one-drop blood), the metabolome panel showed >92% accuracy/sensitivity and specificity for prediction of mortality. CONCLUSIONS: In ALF, albumin is hyperoxidised and substantially dysfunctional. Our study outlines distinct 'albuminome' signatures capable of distinguishing patients with ALF predisposed to early mortality or requiring emergency liver transplantation. IMPACTS AND IMPLICATIONS: Here, we report that the biomolecular map of albumin is distinct and linked to severity and outcome in patients with acute liver failure (ALF). Detailed structural, functional, and albumin-omics analysis in patients with ALF led to the identification and classification of albumin-bound biomolecules, which could segregate patients with ALF predisposed to early mortality. More importantly, we found albumin-bound metabolites indicative of mitochondrial damage and hyperinflammation as a putative indicator of <30-day mortality in patients with ALF. This preclinical study validates the utility of albuminome analysis for understanding the pathophysiology and development of poor outcome indicators in patients with ALF.

Establishment of an in vitro organoid model of dermal papilla of human hair follicle.

Human hair dermal papilla (DP) cells are specialized mesenchymal cells that play a pivotal role in hair regeneration and hair cycle activation. The current study aimed to first develop three-dimensional (3D) DP spheroids (DPS) with or without a silk-gelatin (SG) microenvironment, which showed enhanced DP-specific gene expression, resulting in enhanced extracellular matrix (ECM) production compared with a monolayer culture. We tested the feasibility of using this DPS model for drug screening by using minoxidil, which is a standard drug for androgenic alopecia. Minoxidil-treated DPS showed enhanced expression of growth factors and ECM proteins. Further, an attempt has been made to establish an in vitro 3D organoid model consisting of DPS encapsulated by SG hydrogel and hair follicle (HF) keratinocytes and stem cells. This HF organoid model showed the importance of structural features, cell-cell interaction, and hypoxia akin to in vivo HF. The study helped to elucidate the molecular mechanisms to stimulate cell proliferation, cell viability, and elevated expression of HF markers as well as epithelial-mesenchymal crosstalks, demonstrating high relevance to human HF biology. This simple in vitro DP organoid model system has the potential to provide significant insights into the underlying mechanisms of HF morphogenesis, distinct molecular signals relevant to different stages of the hair cycle, and hence can be used for controlled evaluation of the efficacy of new drug molecules.

Interleukin-28b CC genotype predicts early treatment response and CT/TT genotypes predicts non-response in patients infected with HCV genotype 3.

Response to antiviral therapy for hepatitis C virus (HCV) depends upon the genotype and host immune response. IL28b gene mutations have been shown to modulate host antiviral immune response against genotype 1. However, the predictive value of IL28b polymorphism in genotype 3 HCV patients is largely unknown. The association of IL28b polymorphism with virological response was studied in 356 patients with genotype 3 chronic HCV undergoing treatment with peg-interferon and ribavirin and was compared with matched controls. IL28b genotyping followed by DNA sequencing was performed to identify the CC, CT, or TT genotypes. Two log reduction of HCV RNA at Day 7 (Quick Viral Response, QVR) and HCV RNA negativity at Day 28 (Rapid Viral Response, RVR) were analyzed with CC and non-CC genotypes in addition to other predictors of response. The associations of alleles with the response patterns were predicted. Sustained viral response was seen in 250 (70.2%) patients and the IL28b genotype CC/CT/TT distribution was 61.1%; 30.5%; and 8.4%, respectively. The non-CC genotypes were significantly higher in non-responders when compared to responders (67.6% vs. 38.9%, P < 0.001). Interestingly, the rapid viral response in responders was observed in 72.7% with the CC genotype and in 27.2% with the non-CC genotype (P < 0.001). Multivariate analysis showed CC genotype as an independent factor predicting the sustained viral response in patients infected with HCV genotype 3. In conclusion, the IL28b CT/TT genotype strongly correlates with treatment non-response in patients infected with HCV genotype 3 and CC genotype of IL28b is associated with higher quick viral response.

Circulating bacterial peptides and linked metabolomic signatures are indicative of early mortality in pediatric cirrhosis.

BACKGROUND: Patients with pediatric cirrhosis-sepsis (PC-S) attain early mortality. Plasma bacterial composition, the cognate metabolites, and their contribution to the deterioration of patients with PC-S to early mortality are unknown. We aimed to delineate the plasma metaproteome-metabolome landscape and identify molecular indicators capable of segregating patients with PC-S predisposed to early mortality in plasma, and we further validated the selected metabolite panel in paired 1-drop blood samples using untargeted metaproteomics-metabolomics by UHPLC-HRMS followed by validation using machine-learning algorithms. METHODS: We enrolled 160 patients with liver diseases (cirrhosis-sepsis/nonsepsis [n=110] and noncirrhosis [n=50]) and performed untargeted metaproteomics-metabolomics on a training cohort of 110 patients (Cirrhosis-Sepsis/Nonsepsis, n=70 and noncirrhosis, n=40). The candidate predictors were validated on 2 test cohorts-T1 (plasma test cohort) and T2 (1-drop blood test cohort). Both T1 and T2 had 120 patients each, of which 70 were from the training cohort. RESULTS: Increased levels of tryptophan metabolites and Salmonella enterica and Escherichia coli-associated peptides segregated patients with cirrhosis. Increased levels of deoxyribose-1-phosphate, N5-citryl-d-ornithine, and Herbinix hemicellulolytic and Leifsonia xyli segregated patients with PC-S. MMCN-based integration analysis of WMCNA-WMpCNA identified key microbial-metabolic modules linked to PC-S nonsurvivors. Increased Indican, Staphylobillin, glucose-6-phosphate, 2-octenoylcarnitine, palmitic acid, and guanidoacetic acid along with L. xyli, Mycoplasma genitalium, and Hungateiclostridium thermocellum segregated PC-S nonsurvivors and superseded the liver disease severity indices with high accuracy, sensitivity, and specificity for mortality prediction using random forest machine-learning algorithm. CONCLUSIONS: Our study reveals a novel metabolite signature panel capable of segregating patients with PC-S predisposed to early mortality using as low as 1-drop blood.

Hyperoxidized Albumin Modulates Platelets and Promotes Inflammation Through CD36 Receptor in Severe Alcoholic Hepatitis.

Hyperoxidized albumin promotes inflammation and modulates several immune cells in severe alcoholic hepatitis (SAH). Platelets mediate inflammation by interacting with immune cells, endothelium, and other cells. The role of hyperoxidized albumin in platelet activation and alteration of platelet phenotype/functions is not known. Quantitative platelet proteomics performed in 10 patients with SAH was compared with 10 patients with alcoholic cirrhosis and 10 healthy controls, respectively. Dysregulated pathways were identified and validated in a separate cohort (n = 40). Healthy platelets were exposed to patient plasma or purified albumin or ex vivo modified albumin (human-mercaptalbumin, humannonmercaptalbumin-1, and human nonmercaptalbumin 2) in the presence or absence of CD36 blockade, and platelet secretome was analyzed. Two hundred and two up-regulated proteins linked to platelet activation, complement regulation, lipid transportation, and 321 down-regulated proteins related to platelet hemostasis and coagulation (fold change ± 1.5, P < 0.01) were identified. Blood transcription module enrichment showed an inflammatory phenotype of SAH platelet. Increased level of platelet factor-4, P-selectin, and soluble cluster of differentiation-40 ligand correlated with severity (Model for End-Stage Liver Disease score, r > 0.3, P < 0.05) in SAH. Transcripts linked to platelet activation (increased) and granular secretions (decreased in SAH) correlated with disease severity. SNARE (soluble-N-ethylmaleimide-sensitive-factor-activating-protein-receptor) complex proteins (SNAP-23 [synaptosomal-associated protein 23] and VAMP-8 [vesicle-associated membrane protein 3]) were down-regulated in SAH platelets (P < 0.05). In vitro stimulation of healthy platelets showed enhanced activation with patient plasma, or purified albumin-treatment blocking of CD36 blunted this effect (P < 0.05). Ex vivo modified albumin (primarily nonmercaptalbumin-human nonmercaptalbumin 2 [HNA2; 1 mg/mL]) showed high activation and aggregation and intracellular reactive oxygen species production in healthy platelets (P < 0.05), which significantly reduced after CD36 neutralization. Platelet secretome showed reduced inflammatory mediators and increased repair proteins. Conclusion: Hyperoxidized albumin triggers platelet activation (possibly through the CD36 receptor), promotes inflammation and oxidative stress, and contributes to disease severity in patients with SAH.

Dysregulated Lipid Transport Proteins Correlate With Pathogenesis and Outcome in Severe Alcoholic Hepatitis.

Severe alcoholic hepatitis (SAH) has high mortality. Dysregulated lipid transport and metabolism in liver/macrophages contributes to disease pathophysiology. Paraoxonase/arylesterase 1 (PON1), a liver-specific enzyme, inhibits oxidation of phospholipids and prevents lipid-mediated oxidative damage. However, its functional contribution in macrophage-mediated hepatic injury warrants elucidation. Plasma proteome of patients with SAH (n = 20), alcoholic cirrhosis (n = 20), and healthy controls was analyzed. Dysregulated pathways were identified, validated, and correlated with severity and outcomes in 200 patients with SAH. Tohoku-Hospital-Pediatrics-1 (THP1)-derived macrophages were treated with plasma from study groups in the presence/absence of recombinant PON1 and the phenotype; intracellular lipid bodies and linked functions were evaluated. In patients with SAH, 208 proteins were >1.5 fold differentially regulated (32 up-regulated and 176 down-regulated; P < 0.01).Validation studies confirmed lower levels of lipid transporter proteins (Pon1, apolipoprotein [Apo]B, ApoA1, ApoA2, and ApoC3; P < 0.01). Low PON1 levels inversely correlated with severity and mortality (r2 > 0.3; hazard ratio, 0.91; P < 0.01) and predicted nonsurvivors (area under the receiver operating characteristic curve, 0.86; cut-off, <18 µg/mL; log rank, <0.01). Low PON1 levels corroborated with increased oxidized low-density lipoprotein levels, intracellular lipid bodies, lipid uptake, lipid metabolism, biosynthesis, and alternative macrophage activation genes in nonsurvivors (P < 0.01). Importantly, in vitro recombinant PON1 treatment on THP1 macrophages reversed these changes (P < 0.01), specifically by alteration in expression of clusters of differentiation 36 (CD36) and adenosine triphosphate-binding cassette subfamily A1 (ABCA1) receptor on macrophages. Conclusion: Lipid transport proteins contribute to the pathogenesis of SAH, and low PON1 levels inversely correlate with the severity of alcoholic hepatitis and 28-day mortality. Restitution of circulating PON1 may be beneficial and needs therapeutic evaluation in patients with SAH.

Mucosal-associated invariant T cells are a profibrogenic immune cell population in the liver.

Liver fibrosis is the common response to chronic liver injury, and leads to cirrhosis and its complications. Persistent inflammation is a driving force of liver fibrosis progression. Mucosal-associated invariant T (MAIT) cells are non-conventional T cells that display altered functions during chronic inflammatory diseases. Here, we show that circulating MAIT cells are reduced in patients with alcoholic or non-alcoholic fatty liver disease-related cirrhosis while they accumulate in liver fibrotic septa. Using two models of chronic liver injury, we demonstrate that MAIT cell-enriched mice show increased liver fibrosis and accumulation of hepatic fibrogenic cells, whereas MAIT cell-deficient mice are resistant. Co-culture experiments indicate that MAIT cells enhance the proinflammatory properties of monocyte-derived macrophages, and promote mitogenic and proinflammatory functions of fibrogenic cells, via distinct mechanisms. Our results highlight the profibrogenic functions of MAIT cells and suggest that targeting MAIT cells may constitute an attractive antifibrogenic strategy during chronic liver injury.

Association of adiponectin gene functional polymorphisms (-11377C/G and +45T/G) with nonalcoholic fatty liver disease.

Adiponectin levels are reduced in NAFLD patients and genetic variants of adiponectin have been frequently associated with type 2 diabetes and insulin resistance. To determine the genotypic frequencies of adiponectin functional polymorphisms (-11377C/G and +45T/G) and their subsequent effect on disease progression and plasma adiponectin levels in the patients with NAFLD. A total of 137 NAFLD patients and 250 matched controls were enrolled in the study. DNA sequencing and genotyping were performed to identify the genetic variants. The plasma adiponectin levels were assessed by ELISA. Homozygous mutant genotype of adiponectin SNPs, -11377C/G and +45T/G, were significantly more prevalent in NAFLD patients than controls (Bonferroni corrected p=0.014 and 0.018, respectively). Plasma adiponectin levels were significantly lower in the NAFLD patients as compared to controls. Moreover, presence of 'G' allele at position -11377C/G and +45T/G was found to be associated with necroinflammatory grade and reduced adiponectin levels, (p values 0.02 and 0.01) respectively. -11377G and +45G alleles are associated with severity of liver disease and hypoadiponectemia, in the patients with NAFLD, respectively.