Differences in branched-chain amino acid to tyrosine ratio (BTR) among etiologies of chronic liver disease progression compared to healthy adults

BACKGROUND

The branched-chain amino acids (BCAAs) to tyrosine (Tyr) ratio (BTR) test is used to evaluate the progression of chronic liver disease (CLD). However, the differences across sex, age, body mass index (BMI) and etiologies are still unclear.

METHODS

We retrospectively reviewed data from 2,529 CLD cases with free amino acids (FAAs) in peripheral blood from four hospitals and 16,421 general adults with FAAs data from a biobank database. In total, 1,326 patients with CLD (covering seven etiologies) and 8,086 healthy controls (HCs) were analyzed after exclusion criteria. We investigated the change of BTR in HCs by sex, age and BMI and then compared these to patients divided by modified ALBI (mALBI) grade after propensity score matching.

RESULTS

BTR is significantly higher in males than females regardless of age or BMI and decreases with aging in HCs. In 20 types of FAAs, 7 FAAs including BCAAs were significantly decreased, and 11 FAAs including Tyr were significantly increased by mALBI grade in total CLD. The decreasing timings of BTR were at mALBI grade 2b in all CLD etiologies compared to HCs, however in chronic hepatitis C (CHC), chronic hepatitis B (CHB) and alcoholic liver disease (ALD), BTR started to decrease at 2a. There was a positive correlation between BCAAs and albumin among parameters in BTR and mALBI. The correlation coefficients in PBC, ALD and MASLD were higher than those of other etiologies.

CONCLUSIONS

BTR varies by sex and age even among healthy adults, and decreasing process and timing of BTR during disease progression is different among CLD etiologies.

Diet high in branched-chain amino acid promotes PDAC development by USP1-mediated BCAT2 stabilization

BCAT2-mediated branched-chain amino acid (BCAA) catabolism is critical for pancreatic ductal adenocarcinoma (PDAC) development, especially at an early stage. However, whether a high-BCAA diet promotes PDAC development in vivo, and the underlying mechanism of BCAT2 upregulation, remain undefined. Here, we find that a high-BCAA diet promotes pancreatic intraepithelial neoplasia (PanIN) progression in LSL-Kras^G12D/+; Pdx1-Cre (KC) mice. Moreover, we screened with an available deubiquitylase library which contains 31 members of USP family and identified that USP1 deubiquitylates BCAT2 at the K229 site. Furthermore, BCAA increases USP1 protein at the translational level via the GCN2-eIF2α pathway both in vitro and in vivo. More importantly, USP1 inhibition recedes cell proliferation and clone formation in PDAC cells and attenuates pancreas tumor growth in an orthotopic transplanted mice model. Consistently, a positive correlation between USP1 and BCAT2 is found in KC; LSL-Kras^G12D/+; p53^flox/+; Pdx1-Cre mice and clinical samples. Thus, a therapeutic targeting USP1-BCAT2-BCAA metabolic axis could be considered as a rational strategy for treatment of PDAC and precisive dietary intervention of BCAA has potentially translational significance.

Recent Progress on Branched-Chain Amino Acids in Obesity, Diabetes, and Beyond

Branched-chain amino acids (BCAAs) are essential amino acids that are not synthesized in our body; thus, they need to be obtained from food. They have shown to provide many physiological and metabolic benefits such as stimulation of pancreatic insulin secretion, milk production, adipogenesis, and enhanced immune function, among others, mainly mediated by mammalian target of rapamycin (mTOR) signaling pathway. After identified as a reliable marker of obesity and type 2 diabetes in recent years, an increasing number of studies have surfaced implicating BCAAs in the pathophysiology of other diseases such as cancers, cardiovascular diseases, and even neurodegenerative disorders like Alzheimer's disease. Here we discuss the most recent progress and review studies highlighting both correlational and potentially causative role of BCAAs in the development of these disorders. Although we are just beginning to understand the intricate relationships between BCAAs and some of the most prevalent chronic diseases, current findings raise a possibility that they are linked by a similar putative mechanism.

The profiling of plasma free amino acids and the relationship between serum albumin and plasma-branched chain amino acids in chronic liver disease: a single-center retrospective study

BACKGROUND

It is poorly understood how an imbalance of plasma-free amino acids (PFAAs) occurs and how the imbalance shows an association with the serum albumin (sAlb) level during the progression of chronic liver disease (CLDs). The aim of this study is to elucidate the profiles of PFAAs and the relationship between sAlb and PFAAs in recent patients with CLDs during the progression.

METHODS

We retrospectively evaluated the 1569 data of PFAAs data obtained from 908 patients with various CLDs (CHC, CHB. alcoholic, NAFLD/NASH, PBC, AIH, PSC, and cryptogenic). In total, 1140 data of PFAAs could be analyzed in patients with CLDs dependent of their Child-Pugh (CP) score.

RESULTS

Various imbalances in PFAAs were observed in each CLDs during the progression. Univariate and multivariate analysis revealed that among 24 PFAAs, the level of plasma-branched chain amino acids (pBCAAs) was significantly associated with the CP score, especially the sAlb score, in patients with chronic hepatitis C virus (CHC), NAFLD/NASH and PBC. The correlation coefficient values between sAlb and pBCAAs-to-Tyrosine ratio (BTR) in these patients were 0.53, 0.53 and 0.79, respectively. Interestingly, although the pBCAAs in NAFLD/NASH patients varied even when the sAlb was within the normal range, the pBCAAs tended to be low when the sAlb was below the normal range.

CONCLUSIONS

Although a decrease in the level of pBCAAs was observed during the progression regardless of the CLD etiology, the level of total pBCAAs was independently associated with the sAlb level in the PFAAs of CHC, PBC and NAFLD/NASH. The correlation between sAlb and BTR showed the highest value in PBC patients among the patients with CLDs. A decrease in pBCAAs often occurred in NASH even when the sAlb level was kept in the normal range.

Fast and non-invasive serum detection technology based on surface-enhanced Raman spectroscopy and multivariate statistical analysis for liver disease

This study explored a rapid and nondestructive liver disease detection technique based on surface-enhanced Raman spectroscopy (SERS) to realize the early diagnosis, prevention, and treatment of liver disease. SERS signals of serum were obtained from 304 normal individuals, 333 patients with hepatopathy, and 99 patients with esophageal cancer. The Raman spectra of different diseases were compared and diagnostic models of liver disease were established using orthogonal partial least squares discriminant analysis (OPLS-DA). The classification efficiencies of the different models were comprehensively evaluated through the receiver operating characteristic (ROC) curve and ten-fold cross validation. Area under the ROC curve is of greater than 0.97, indicating excellent classification of the groups. The accuracy rate of the test set reached 95.33%, and the lowest was 81.76% using the ten-fold cross validation. Thus, OPLS-DA combined with serum SERS is a rapid and non-invasive technique for the diagnosis of liver disease.

Adjuvant and chemopreventive therapies for resectable hepatocellular carcinoma: a literature review

The recurrence rate of hepatocellular carcinoma (HCC) after potentially curative hepatic resection (HR) is very high. Many clinical trials have explored the efficacy of several treatment modalities to prevent recurrence, including adjuvant and chemopreventive therapy, but they have often reported contradictory findings. As a result, most liver guidelines and liver seminars do not unequivocally endorse adjuvant or chemopreventive therapy for HCC patients after potentially curative HR. To examine the available evidence on this question, we comprehensively searched PubMed for controlled studies that included a supportive care or placebo control arm, and we used the GRADE system to classify and assess the results.