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

Significance of Immune and Non-Immune Cell Stroma as a Microenvironment of Hepatocellular Carcinoma-From Inflammation to Hepatocellular Carcinoma Progression

Hepatocellular carcinoma (HCC) is the most common liver cancer as well as the most prevalent cause of death in the adult patient population with cirrhosis. The occurrence of HCC is primarily caused by chronic liver inflammation that might occur because of a viral infection, non-alcoholic fatty liver disease (NAFLD), or various lifestyle-associated factors. The objective of this review was to summarize the current knowledge regarding the microenvironment of HCC, indicating how immune- and non-immune-cell stroma might affect the onset and progression of HCC. Therefore, in the following narrative review, we described the role of tumor-infiltrating neutrophils, bone-marrow-derived cells, tumor-associated mast cells, cancer-associated fibroblasts, tumor-associated macrophages, liver-sinusoidal endothelial cells, lymphocytes, and certain cytokines in liver inflammation and the further progression to HCC. A better understanding of the HCC microenvironment might be crucial to introducing novel treatment strategies or combined therapies that could lead to more effective clinical outcomes.

Organic Trace Minerals Enhance the Gut Health of British Shorthair Cats by Regulating the Structure of Intestinal Microbiota

Trace minerals are essential for biological processes, including enzyme function, immune response, and hormone synthesis. The study assessed the effects of different dietary trace minerals on the gut health, microbiota composition, and immune function of cats. Eighteen adult British Shorthair cats were divided into three groups receiving inorganic trace minerals (ITM), a 50/50 mix of inorganic and organic trace minerals (ITM + OTM), or organic trace minerals (OTM) for 28 days. The OTM showed enhanced immune capacities, reduced intestinal barrier function, and lower inflammation condition. The OTM altered gut microbiota diversity, with a lower Simpson index and higher Shannon index (p < 0.05). Specifically, the abundance of Bacteroidota, Lachnospiraceae, and Prevotella in the OTM group were higher than the ITM group (p < 0.05). Metabolomic analysis identified 504 differential metabolites between the OTM and ITM groups (p < 0.05, VIP-pred-OPLS-DA > 1), affecting pathways related to steroid hormone biosynthesis and glycerophospholipid metabolism (p < 0.05, VIP-pred-OPLS-DA > 2). Additionally, there was a significant correlation between intestinal microbiota and differential metabolites. To conclude, dietary OTM can modulate the gut metabolite and microbiota composition, enhance immune and intestinal barrier function, and mitigate inflammation in cats, highlighting the benefit of using OTM in feline diet to promote the intestinal and overall health.

Ba-Qi-Rougan formula alleviates hepatic fibrosis by suppressing hepatic stellate cell activation via the MSMP/CCR2/PI3K pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The Ba-Qi-Rougan formula (BQRGF) is a traditional and effective compound prescription from Traditional Chinese Medicine (TCM) utilized in treating hepatic fibrosis (HF).

AIM OF THE STUDY

We aimed to evaluate the therapeutic efficacy of BQRGF on HF and explore the underlying mechanisms of action.

MATERIALS AND METHODS

UPLC-Q-TOF-MS technology was employed to identify the material basis of BQRGF. Mice with carbon tetrachloride (CCl4)-induced HF received BQRGF at three doses (3.87, 7.74, and 15.48 g/kg per day). We examined serum and liver biochemical indicators and liver histology to assess the therapeutic impact. Primary mouse cells were isolated and utilized for experimental analysis. MSMP expression levels were examined in vitro and in vivo experimental models, including human and mouse tissue. Furthermore, lentivirus and small interfering RNA (siRNA) transfections were employed to manipulate microseminoprotein (MSMP) expression in LO2 cells (human normal liver cells). These manipulated LO2 cells were then co-cultured with LX2 human hepatic stellate cells (HSCs). Through the modulation of MSMP expression in co-cultured cells, administering recombinant MSMP (rMSMP) with or without BQRGF-medicated serum, and using specific pathway inhibitors or agonists in LX2 cells, we elucidated the underlying mechanisms.

RESULTS

A total of 48 compounds were identified from BQRGF, with 12 compounds being absorbed into the bloodstream and 9 compounds being absorbed into the liver. Four weeks of BQRGF treatment in the HF mouse model led to significant improvements in biochemical and molecular assays and histopathology, particularly in the medium and high-dose groups. These improvements included a reduction in the level of liver injury and fibrosis-related factors. MSMP levels were elevated in human and mouse fibrotic liver tissues, and this increase was mitigated in HF mice treated with BQRGF. Moreover, primary cells and co-culture studies revealed that BQRGF reduced MSMP expression, decreased the expression of the hepatic stellate cell (HSC) activation markers, and suppressed critical phosphorylated protein levels in the CCR2/PI3K/AKT pathway. These findings were further validated using CCR2/PI3K/AKT signaling inhibitors and agonists in MSMP-activated LX2 cells.

CONCLUSIONS

Collectively, our results suggest that BQRGF combats HF by diminishing MSMP levels and inhibiting MSMP-induced HSC activation through the CCR2/PI3K/AKT pathway.

The m6A reader IGF2BP2 regulates glycolytic metabolism and mediates histone lactylation to enhance hepatic stellate cell activation and liver fibrosis

Evidence for the involvement of N6-Methyladenosine (m6A) modification in the etiology and progression of liver fibrosis has emerged and holds promise as a therapeutic target. Insulin-like growth factor 2 (IGF2) mRNA-binding protein 2 (IGF2BP2) is a newly identified m6A-binding protein that functions to enhance mRNA stability and translation. However, its role as an m6A-binding protein in liver fibrosis remains elusive. Here, we observed that IGF2BP2 is highly expressed in liver fibrosis and activated hepatic stellate cells (HSCs), and inhibition of IGF2BP2 protects against HSCs activation and liver fibrogenesis. Mechanistically, as an m6A-binding protein, IGF2BP2 regulates the expression of Aldolase A (ALDOA), a key target in the glycolytic metabolic pathway, which in turn regulates HSCs activation. Furthermore, we observed that active glycolytic metabolism in activated HSCs generates large amounts of lactate as a substrate for histone lactylation. Importantly, histone lactylation transforms the activation phenotype of HSCs. In conclusion, our findings reveal the essential role of IGF2BP2 in liver fibrosis by regulating glycolytic metabolism and highlight the potential of targeting IGF2BP2 as a therapeutic for liver fibrosis.

Harnessing Schistosoma-associated metabolite changes in the human host to identify biomarkers of infection and morbidity: Where are we and what should we do next?

Schistosomiasis is the second most widespread parasitic disease affecting humans. A key component of today's infection control measures is the diagnosis and monitoring of infection, informing individual- and community-level treatment. However, newly acquired infections and/or low parasite burden are still difficult to diagnose reliably. Furthermore, even though the pathological consequence of schistosome egg sequestration in host tissues is well described, the evidence linking egg burden to morbidity is increasingly challenged, making it inadequate for pathology monitoring. In the last decades, omics-based instruments and methods have been developed, adjusted, and applied in parasitic research. In particular, the profiling of the most reliable determinants of phenotypes, metabolites by metabolomics, emerged as a powerful boost in the understanding of basic interactions within the human host during infection. As such, the fine detection of host metabolites produced upon exposure to parasites such as Schistosoma spp. and the ensuing progression of the disease are believed to enable the identification of Schistosoma spp. potential biomarkers of infection and associated pathology. However, attempts to provide such a comprehensive understanding of the alterations of the human metabolome during schistosomiasis are rare, limited in their design when performed, and mostly inconclusive. In this review, we aimed to briefly summarize the most robust advances in knowledge on the changes in host metabolic profile during Schistosoma infections and provide recommendations for approaches to optimize the identification of metabolomic signatures of human schistosomiasis.

GATA3 promotes the autophagy and activation of hepatic stellate cell in hepatic fibrosis via regulating miR-370/HMGB1 pathway

BACKGROUND

Hepatic fibrosis (HF) is a common result of the repair process of various chronic liver diseases. Hepatic stellate cells (HSCs) activation is the central link in the occurrence of HF.

METHODS

ELISA and histological analysis were performed to detect the pathological changes of liver tissues. In vitro, HSCs were treated with TGF-β1 as HF cell model. Combination of GATA-binding protein 3 (GATA3) and miR-370 gene promoter was ensured by ChIP and luciferase reporter assay. Autophagy was monitored by observing the GFP-LC3 puncta formation. The interaction between miR-370 and high mobility group box 1 protein (HMGB1) was verified by luciferase reporter assay.

RESULTS

CCl4-induced HF mice exhibited an increase of ALT and AST, and severe damage and fibrosis of liver tissues. GATA3 and HMGB1 were up-regulated, and miR-370 was down-regulated in CCl4-induced HF mice and activated HSCs. GATA3 enhanced expression of the autophagy-related proteins and activation markers in the activated HSCs. Inhibition of autophagy partly reversed GATA3-induced activation of HSCs and the promotion of GATA3 to hepatic fibrosis. Moreover, GATA3 suppressed miR-370 expression via binding with its promotor, and enhanced HMGB1 expression in HSCs. Increasing of miR-370 inhibited HMGB1 expression by directly targeting its mRNA 3'-UTR. The promotion of GATA3 to TGF-β1-induced HSCs autophagy and activation was abrogated by miR-370 up-regulation or HMGB1 knockdown.

CONCLUSIONS

This work demonstrates that GATA3 promotes autophagy and activation of HSCs by regulating miR-370/HMGB1 signaling pathway, which contributes to accelerate HF. Thus, this work suggests that GATA3 may be a potential target for prevention and treatment of HF.

Quantitative proteomics reveals the protective effects of Yinchenzhufu decoction against cholestatic liver fibrosis in mice by inhibiting the PDGFRβ/PI3K/AKT pathway

Introduction: Yinchenzhufu decoction (YCZFD) is a traditional Chinese medicine formula with hepatoprotective effects. In this study, the protective effects of YCZFD against cholestatic liver fibrosis (CLF) and its underlying mechanisms were evaluated. Methods: A 3, 5-diethoxycarbonyl-1, 4-dihydro-collidine (DDC)-induced cholestatic mouse model was used to investigate the amelioration of YCZFD on CLF. Data-independent acquisition-based mass spectrometry was performed to investigate proteomic changes in the livers of mice in three groups: control, model, and model treated with high-dose YCZFD. The effects of YCZFD on the expression of key proteins were confirmed in mice and cell models. Results: YCZFD significantly decreased the levels of serum biochemical, liver injury, and fibrosis indicators of cholestatic mice. The proteomics indicated that 460 differentially expressed proteins (DEPs) were identified among control, model, and model treated with high-dose YCZFD groups. Enrichment analyses of these DEPs revealed that YCZFD influenced multiple pathways, including PI3K-Akt, focal adhesion, ECM-receptor interaction, glutathione metabolism, and steroid biosynthesis pathways. The expression of platelet derived growth factor receptor beta (PDGFRβ), a receptor associated with the PI3K/AKT and focal adhesion pathways, was upregulated in the livers of cholestatic mice but downregulated by YCZFD. The effects of YCZFD on the expression of key proteins in the PDGFRβ/PI3K/AKT pathway were further confirmed in mice and transforming growth factor-β-induced hepatic stellate cells. We uncovered seven plant metabolites (chlorogenic acid, scoparone, isoliquiritigenin, glycyrrhetinic acid, formononetin, atractylenolide I, and benzoylaconitine) of YCZFD that may regulate PDGFRβ expression. Conclusion: YCZFD substantially protects against DDC-induced CLF mainly through regulating the PDGFRβ/PI3K/AKT signaling pathway.

Knockdown of Hyaluronan synthase 2 suppresses liver fibrosis in mice via induction of transcriptomic changes similar to 4MU treatment

Hepatic fibrosis remains a significant clinical challenge due to ineffective treatments. 4-methylumbelliferone (4MU), a hyaluronic acid (HA) synthesis inhibitor, has proven safe in phase one clinical trials. In this study, we aimed to ameliorate liver fibrosis by inhibiting HA synthesis. We compared two groups of mice with CCl4-induced fibrosis, treated with 4-methylumbelliferone (4MU) and hyaluronan synthase 2 (HAS2) targeting siRNA (siHAS2). The administration of 4MU and siHAS2 significantly reduced collagen and HA deposition, as well as biochemical markers of hepatic damage induced by repeated CCl4 injections. The transcriptomic analysis revealed converging pathways associated with downstream HA signalling. 4MU- and siHAS2-treated fibrotic livers shared 405 upregulated and 628 downregulated genes. These genes were associated with xenobiotic and cholesterol metabolism, mitosis, endoplasmic reticulum stress, RNA processing, and myeloid cell migration. The functional annotation of differentially expressed genes (DEGs) in siHAS2-treated mice revealed attenuation of extracellular matrix-associated pathways. In comparison, in the 4MU-treated group, DEGs were related to lipid and bile metabolism pathways and cell cycle. These findings confirm that HAS2 is an important pharmacological target for suppressing hepatic fibrosis using siRNA.

Histopathological, physiological, and multi-omics insights into the hepatotoxicity mechanism of nanopolystyrene and/or diclofenac in Mylopharyngodon piceus

Nanopolystyrene (NP) and diclofenac (DCF) are common environmental contaminants in the aquatic ecosystem; therefore, the present study aimed to investigate the hepatotoxicity of NP and/or DCF exposure on aquatic organisms and the underlying mechanisms. Juvenile Mylopharyngodon piceus were used as a model organism to study the effects of NP and/or DCF exposure at environmentally relevant concentrations for 21 days. Subchronic exposure to NP and/or DCF resulted in liver histological damage. In the NP group, the presence of large lipid droplets was observed, whereas the DCF group exhibited marked hepatic sinusoidal dilatation accompanied by inflammation. Additionally, this exposure induced liver oxidative stress, as evidenced by the changes in several physiological parameters, including catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), reactive oxygen species (ROS), and malondialdehyde (MDA). Integrated transcriptomic and metabolomic analysis was performed to further investigate the molecular mechanism underlying hepatotoxicity. Multi-omics analysis demonstrated, for the first time to our knowledge, that NP induced hepatic steatosis mainly through activating the glycerol-3-phosphate pathway and inhibiting VLDL assembly by targeting several key enzyme genes including GPAT, DGAT, ACSL, APOB, and MTTP. Furthermore, NP exposure disrupted arachidonic acid metabolism, which induced the release of inflammatory factors and inhibited the release of anti-inflammatory factors, ultimately causing liver inflammation in M. piceus. In contrast, DCF induced interleukin production and downregulated KLF2, causing hepatic sinusoidal dilatation with inflammation in juvenile M. piceus, which is consistent with the finding of JAK-STAT signaling pathway activation. In addition, the upregulated AMPK signaling pathway in the DCF group suggested perturbation of energy metabolism. Collectively, these findings provide novel insights into the molecular mechanism of the multiple hepatotoxicity endpoints of NP and/or DCF exposure in aquatic organisms.

Serum infrared spectral profile is predictive of the degree of hepatic fibrosis in chronic hepatitis C patients

Assessment of liver fibrosis is crucial to guide the therapeutic strategy in patients with chronic liver disease. We investigated the potential of serum Fourier transform infrared (FTIR) spectroscopy for assessing the degree of hepatic fibrosis in patients with chronic hepatitis C (CHC). The study was conducted on dried serum samples from 94 CHC patients at different histological stages of hepatic fibrosis: METAVIR F0 (n = 20), F1 (n = 17), F2 (n = 20), F3 (n = 20) and F4 (n = 17). Transmission FTIR spectra were acquired in the 4000-400 cm-1 range. Wavenumbers were selected by genetic algorithm (GA) according to their diagnostic performance as assessed by a partial least squares discriminant analysis (PLS-DA) model using a training and a validation set to differentiate severe stages of fibrosis from mild or moderate ones. The GA procedure was applied 50 times on randomly selected sets. Furthermore, the best set of wavenumbers was re-tested in 1000 randomly selected validation sets. Wavenumbers selected by GA corresponded to functional groups present in lipids, proteins, and carbohydrates. This model allowed to identify patients with cirrhosis (METAVIR F4), patients with advanced fibrosis (METAVIR F3 and F4), and patients with significant fibrosis (METAVIR F2, F3 and F4), with AUROC (Area Under the Receiver Operating Characteristic) of 0.88, 0.85 and 0.85, respectively. Thus, serum FTIR spectroscopy appears to have a strong potential as a new diagnostic tool for assessing the degree of fibrosis in patients with chronic liver disease.

Modulation of the HIF-1α-NCOA4-FTH1 Signaling Axis Regulating Ferroptosis-induced Hepatic Stellate Cell Senescence to Explore the Anti-hepatic Fibrosis Mechanism of Curcumol

INTRODUCTION

Senescence of activated hepatic stellate cells (HSC) reduces extracellular matrix expression to reverse liver fibrosis. Ferroptosis is closely related to cellular senescence, but its regulatory mechanisms need to be further investigated. The iron ions weakly bound to ferritin in the cell are called labile iron pool (LIP), and together with ferritin, they maintain cellular iron homeostasis and regulate the cell's sensitivity to ferroptosis.

METHODS

We used lipopolysaccharide (LPS) to construct a pathological model group and divided the hepatic stellate cells into a blank group, a model group, and a curcumol 12.5 mg/L group, a curcumol 25 mg/L group, and a curcumol 50 mg/L group. HIF-1α-NCOA4- FTH1 signalling axis, ferroptosis and cellular senescence were detected by various cellular molecular biology experiments.

RESULT

We found that curcumol could induce hepatic stellate cell senescence by promoting iron death in hepatic stellate cells. Curcumol induced massive deposition of iron ions in hepatic stellate cells by activating the HIF-1α-NCOA4-FTH1 signalling axis, which further led to iron overload and lipid peroxidation-induced ferroptosis. Interestingly, our knockdown of HIF-1α rescued curcumol-induced LIP and iron deposition in hepatic stellate cells, suggesting that HIF-1α is a key target of curcumol in regulating iron metabolism and ferroptosis. We were able to rescue curcumol-induced hepatic stellate cell senescence when we reduced LIP and iron ion deposition using iron chelators.

CONCLUSION

Overall, curcumol induces ferroptosis and cellular senescence by increasing HIF-1α expression and increasing NCOA4 interaction with FTH1, leading to massive deposition of LIP and iron ions, which may be the molecular biological mechanism of its anti-liver fibrosis.

Serum metabolomics characteristics and fatty-acid-related mechanism of cirrhosis with histological response in chronic hepatitis B

Background and aims: The serum metabolites changes in patients with hepatitis B virus (HBV)-related cirrhosis as progression. Peroxisome proliferator-activated receptor gamma (PPARγ) is closely related to lipid metabolism in cirrhotic liver. However, the relationship between fatty acids and the expression of hepatic PPARγ during cirrhosis regression remains unknown. In this study, we explored the serum metabolic characteristics and expression of PPARγ in patients with histological response to treatment with entecavir. Methods: Sixty patients with HBV-related cirrhosis were selected as the training cohort with thirty patients each in the regression (R) group and non-regression (NR) group based on their pathological changes after 48-week treatment with entecavir. Another 72 patients with HBV-related cirrhosis and treated with entecavir were collected as the validation cohort. All of the serum samples were tested using ultra-performance liquid chromatography coupled to tandem mass spectrometry. Data were processed through principal component analysis and orthogonal partial least square discriminant analysis. Hepatic PPARγ expression was observed using immunohistochemistry. The relationship between serum fatty acids and PPARγ was calculated using Pearson's or Spearman's correlation analysis. Results: A total of 189 metabolites were identified and 13 differential metabolites were screened. Compared to the non-regression group, the serum level of fatty acids was higher in the R group. At baseline, the expression of PPARγ in hepatic stellate cells was positively correlated with adrenic acid (r 2 = 0.451, p = 0.046). The expression of PPARγ in both groups increased after treatment, and the expression of PPARγ in the R group was restored in HSCs much more than that in the NR group (p = 0.042). The adrenic acid and arachidonic acid (AA) in the R group also upgraded more than the NR group after treatment (p = 0.037 and 0.014). Conclusion: Baseline serum differential metabolites, especially fatty acids, were identified in patients with HBV-related cirrhosis patients who achieved cirrhosis regression. Upregulation of adrenic acid and arachidonic acid in serum and re-expression of PPARγ in HSCs may play a crucial role in liver fibrosis improvement.

Exosomes from adipose-derived mesenchymal stem cells improve liver fibrosis by regulating the miR-20a-5p/TGFBR2 axis to affect the p38 MAPK/NF-κB pathway

OBJECTIVE

Human adipose-derived mesenchymal stem cell exosomes (ADSC-Exos) are active constituents for treating liver fibrosis. This paper attempted to preliminarily explain the functional mechanism of ADSC-Exos in liver fibrosis through the p38 MAPK/NF-κB pathway.

METHODS

The cell models of hepatic fibrosis were established by inducing LX-2 cells with TGF-β1. Mouse models of liver fibrosis were established by treating mice with CCl4. The in vivo and in vitro models of liver fibrosis were treated with ADSC-Exos. ADSCs were identified by flow cytometry/Alizarin red/oil red O/alcian blue staining. ADSC-Exos were identified by transmission electron microscopy, nanoparticle tracking analysis, and Western blot. LX-2 cell proliferation/viability were evaluated by MTT/BrdU assays. Exosomes were tracked in vivo and body weight changes in mice were monitored. Hepatic pathological changes were observed by HE/Masson staining. α-SMA/collagen I levels in liver tissues were assessed by immunohistochemistry. HA/PIIINP concentrations were measured using the magnetic particle chemiluminescence method. Liver function was assessed using an automatic analyzer. miR-20a-5p level was measured by RT-qPCR. The mRNA levels of fibrosis markers were determined by RT-qPCR, and their protein levels and levels of MAPK/NF-κB pathway-related proteins, as well as TGFBR2 protein level were measured by Western blot. The P65 nuclear expression in mouse liver tissues was quantified by immunofluorescence.

RESULTS

ADSC-Exos suppressed TGF-β1-induced LX-2 cell proliferation and fibrosis and reduced mRNA and protein levels of fibrosis markers in vitro. ADSC-Exos ameliorated liver fibrosis by inhibiting the p38 MAPK/NF-κB pathway activation. ADSC-Exos inhibited activation of the p38 MAPK/NF-κB pathway via regulating the miR-20a-5p/TGFBR2 axis. The in vivo experiment asserted that ADSC-Exos were mainly distributed in the liver, and ADSC-Exos relieved liver fibrosis in mice, which was evidenced by alleviating decreased body weight, reducing collagen and enhancing liver function, and repressed the activation of the p38 MAPK/NF-κB pathway via the miR-20a-5p/TGFBR2 axis.

CONCLUSION

ADSC-Exos attenuated liver fibrosis by suppressing the activation of the p38 MAPK/NF-κB pathway via the miR-20a-5p/TGFBR2 axis.

Aggravated hepatic fibrosis induced by phenylalanine and tyrosine was ameliorated by chitooligosaccharides supplementation

Hepatic fibrosis is a classic pathological manifestation of metabolic chronic hepatopathy. The pathological process might either gradually deteriorate into cirrhosis and ultimately liver cancer with inappropriate nutrition supply, or be slowed down by several multifunctional nutrients, alternatively. Herein, we found diet with excessive phenylalanine (Phe) and tyrosine (Tyr) exacerbated hepatic fibrosis symptoms of liver dysfunction and gut microflora dysbiosis in mice. Chitooligosaccharides (COS) could ameliorate hepatic fibrosis with the regulation of amino acid metabolism by downregulating the mTORC1 pathway, especially that of Phe and Tyr, and also with the alleviation of the dysbiosis of gut microbiota, simultaneously. Conclusively, this work presents new insight into the role of Phe and Tyr in the pathologic process of hepatic fibrosis, while revealing the effectiveness and molecular mechanism of COS in improving hepatic fibrosis from the perspective of metabolites.

Protein Lactylation Modification and Proteomics Features in Cirrhosis Patients after UC-MSC Treatment

Umbilical cord mesenchymal stem cell (UC-MSC) therapy improves liver function in liver cirrhosis patients. This study aimed to elucidate the therapeutic mechanism underlying cell therapy by analyzing changes in the modification and expression of proteins 1 month post-treatment with UC-MSCs. This prospective study included 11 cirrhosis patients who received MSC injection. The laboratory indexes before and after treatment were collected to evaluate the clinical treatment effect of UC-MSCs, and the protein expression and lactylation modification in the liver were comprehensively revealed. Meanwhile, weighted gene co-expression network analysis was used to analyze the co-expression protein modules and their relationship with clinical features. The patients with liver cirrhosis showed an improvement trend after receiving UC-MSC treatment; specifically, the liver protein synthesis function was significantly improved and the coagulation function was also significantly improved. Proteomics combined with lactic acid proteomics revealed 160 lysine lactylation (Kla) sites of 119 proteins. Functional analysis showed that the lactylation-modified proteins were enriched in the pathway of glucose and other substances' metabolism, and many key enzymes of glycolysis and gluconeogenesis were lactated. UC-MSC therapy has a certain clinical effect in the treatment of liver cirrhosis and may act by regulating material metabolism, because the lactylation protein points to energy metabolism.

Fibrosis Development Linked to Alterations in Glucose and Energy Metabolism and Prooxidant-Antioxidant Balance in Experimental Models of Liver Injury

The development of liver fibrosis is one of the most severe and life-threatening outcomes of chronic liver disease (CLD). For targeted therapy of CLD, it is highly needed to reveal molecular targets for normalizing metabolic processes impaired in damaged liver and associated with fibrosis. In this study, we investigated the morphological and biochemical changes in rat liver models of fibrosis induced by chronic administration of thioacetamide, carbon tetrachloride, bile duct ligation (BDL), and ischemia/reperfusion (I/R), with a specific focus on carbohydrate and energy metabolism. Changes in the levels of substrates and products, as well as enzyme activities of the major glucose metabolic pathways (glycolysis, glucuronidation, and pentose phosphate pathway) were examined in rat liver tissue after injury. We examined key markers of oxidative energy metabolism, such as the activity of the Krebs cycle enzymes, and assessed mitochondrial respiratory activity. In addition, pro- and anti-oxidative status was assessed in fibrotic liver tissue. We found that 6 weeks of exposure to thioacetamide, carbon tetrachloride, BDL or I/R resulted in a decrease in the activity of glycolytic enzymes, retardation of mitochondrial respiration, elevation of glucuronidation, and activation of pentose phosphate pathways, accompanied by a decrease in antioxidant activity and the onset of oxidative stress in rat liver. Resemblance and differences in the changes in the fibrosis models used are described, including energy metabolism alterations and antioxidant status in the used fibrosis models. The least pronounced changes in glucose metabolism and mitochondrial functions in the I/R and thioacetamide models were associated with the least advanced fibrosis. Ultimately, liver fibrosis significantly altered the metabolic profile in liver tissue and the flux of glucose metabolic pathways, which could be the basis for targeted therapy of liver fibrosis in CLD caused by toxic, cholestatic, or I/R liver injury.

Short-term exposure to antimony induces hepatotoxicity and metabolic remodeling in rats

Antimony (Sb) poses a significant threat to human health due to sharp increases in its exploitation and application globally, but few studies have explored the pathophysiological mechanisms of acute hepatotoxicity induced by Sb exposure. We established an in vivo model to comprehensively explore the endogenous mechanisms underlying liver injury induced by short-term Sb exposure. Adult female and male Sprague-Dawley rats were orally administrated various concentrations of potassium antimony tartrate for 28 days. After exposure, the serum Sb concentration, liver-to-body weight ratio, and serum glucose levels significantly increased in a dose-dependent manner. Body weight gain and serum concentrations of biomarkers of hepatic injury (e.g., total cholesterol, total protein, alkaline phosphatase, and the aspartate aminotransferase/alanine aminotransferase ratio) decreased with increasing Sb exposure. Through integrative non-targeted metabolome and lipidome analyses, alanine, aspartate, and glutamate metabolism; phosphatidylcholines; sphingomyelins; and phosphatidylinositols were the most significantly affected pathways in female and male rats exposed to Sb. Additionally, correlation analysis showed that the concentrations of certain metabolites and lipids (e.g., deoxycholic acid, N-methylproline, palmitoylcarnitine, glycerophospholipids, sphingomyelins, and glycerol) were significantly associated with hepatic injury biomarkers, indicating that metabolic remodeling may be involved in apical hepatotoxicity. Our study demonstrated that short-term exposure to Sb induces hepatotoxicity, possibly through a glycolipid metabolism disorder, providing an important reference for the health risks of Sb pollution.

Metabolic Hijacking of Hexose Metabolism to Ascorbate Synthesis Is the Unifying Biochemical Basis of Murine Liver Fibrosis

We wished to understand the metabolic reprogramming underlying liver fibrosis progression in mice. Administration to male C57BL/6J mice of the hepatotoxins carbon tetrachloride (CCl4), thioacetamide (TAA), or a 60% high-fat diet, choline-deficient, amino-acid-defined diet (HF-CDAA) was conducted using standard protocols. Livers collected at different times were analyzed by gas chromatography-mass spectrometry-based metabolomics. RNA was extracted from liver and assayed by qRT-PCR for mRNA expression of 11 genes potentially involved in the synthesis of ascorbic acid from hexoses, Gck, Adpgk, Hk1, Hk2, Ugp2, Ugdh, Ugt1a1, Akr1a4, Akr1b3, Rgn and Gulo. All hepatotoxins resulted in similar metabolic changes during active fibrogenesis, despite different etiology and resultant scarring pattern. Diminished hepatic glucose, galactose, fructose, pentose phosphate pathway intermediates, glucuronic acid and long-chain fatty acids were compensated by elevated ascorbate and the product of collagen prolyl 4-hydroxylase, succinate and its downstream metabolites fumarate and malate. Recovery from the HF-CDAA diet challenge (F2 stage fibrosis) after switching to normal chow was accompanied by increased glucose, galactose, fructose, ribulose 5-phosphate, glucuronic acid, the ascorbate metabolite threonate and diminished ascorbate. During the administration of CCl4, TAA and HF-CDAA, aldose reductase Akr1b3 transcription was induced six- to eightfold, indicating increased conversion of glucuronic acid to gulonic acid, a precursor of ascorbate synthesis. Triggering hepatic fibrosis by three independent mechanisms led to the hijacking of glucose and galactose metabolism towards ascorbate synthesis, to satisfy the increased demand for ascorbate as a cofactor for prolyl 4-hydroxylase for mature collagen production. This metabolic reprogramming and causal gene expression changes were reversible. The increased flux in this pathway was mediated predominantly by increased transcription of aldose reductase Akr1b3.

Dysregulated systemic metabolism in a Down syndrome mouse model

OBJECTIVE

Trisomy 21 is one of the most complex genetic perturbations compatible with postnatal survival. Dosage imbalance arising from the triplication of genes on human chromosome 21 (Hsa21) affects multiple organ systems. Much of Down syndrome (DS) research, however, has focused on addressing how aneuploidy dysregulates CNS function leading to cognitive deficit. Although obesity, diabetes, and associated sequelae such as fatty liver and dyslipidemia are well documented in the DS population, only limited studies have been conducted to determine how gene dosage imbalance affects whole-body metabolism. Here, we conduct a comprehensive and systematic analysis of key metabolic parameters across different physiological states in the Ts65Dn trisomic mouse model of DS.

METHODS

Ts65Dn mice and euploid littermates were subjected to comprehensive metabolic phenotyping under basal (chow-fed) state and the pathophysiological state of obesity induced by a high-fat diet (HFD). RNA sequencing of liver, skeletal muscle, and two major fat depots were conducted to determine the impact of aneuploidy on tissue transcriptome. Pathway enrichments, gene-centrality, and key driver estimates were performed to provide insights into tissue autonomous and non-autonomous mechanisms contributing to the dysregulation of systemic metabolism.

RESULTS

Under the basal state, chow-fed Ts65Dn mice of both sexes had elevated locomotor activity and energy expenditure, reduced fasting serum cholesterol levels, and mild glucose intolerance. Sexually dimorphic deterioration in metabolic homeostasis became apparent when mice were challenged with a high-fat diet. While obese Ts65Dn mice of both sexes exhibited dyslipidemia, male mice also showed impaired systemic insulin sensitivity, reduced mitochondrial activity, and elevated fibrotic and inflammatory gene signatures in the liver and adipose tissue. Systems-level analysis highlighted conserved pathways and potential endocrine drivers of adipose-liver crosstalk that contribute to dysregulated glucose and lipid metabolism.

CONCLUSIONS

A combined alteration in the expression of trisomic and disomic genes in peripheral tissues contribute to metabolic dysregulations in Ts65Dn mice. These data lay the groundwork for understanding the impact of aneuploidy on in vivo metabolism.

Sarcopenia in the Cirrhotic Patient: Current Knowledge and Future Directions

Cirrhosis predisposes to abnormalities in energy, hormonal, and immunological homeostasis. Disturbances in these metabolic processes create susceptibility to sarcopenia or pathological muscle wasting. Sarcopenia is prevalent in cirrhosis and its presence portends significant adverse outcomes including the length of hospital stay, infectious complications, and mortality. This highlights the importance of identification of at-risk individuals with early nutritional, therapeutic and physical therapy intervention. This manuscript summarizes literature relevant to sarcopenia in cirrhosis, describes current knowledge, and elucidates possible future directions.

The role of hepatic microenvironment in hepatic fibrosis development

AIM

Fibrosis is a common pathological feature of most types of chronic liver injuries. There is no specific treatment for liver fibrosis at present. The liver microenvironment, which fosters the survival and activity of liver cells, plays an important role in maintaining the normal structure and physiological function of the liver. The aim of this review is to deeply understand the role of the liver microenvironment in the dynamic and complicated development of liver fibrosis.

METHODS

After searching in Elsevier ScienceDirect, PubMed and Web of Science databases using 'liver fibrosis' and 'microenvironment' as keywords, studies related to microenvironment in liver fibrosis was compiled and examined.

RESULTS

The homeostasis of the liver microenvironment is disrupted during the development of liver fibrosis, affecting liver cell function, causing various types of cell reactions, and changing the cell-cell and cell-matrix interactions, eventually affecting fibrosis formation.

CONCLUSION

Liver microenvironment may be important for identifying potential therapeutic targets, and restoring microenvironment homeostasis may be an important strategy for promoting the reversal of liver fibrosis.KEY MESSAGESThe homeostasis of the liver microenvironment is disrupted in liver fibrosis;A pro-fibrotic microenvironment is formed during the development of liver fibrosis;Restoring microenvironment homeostasis may be an important strategy for promoting the reversal of liver fibrosis.

Targeting glutamine metabolism in hepatic stellate cells alleviates liver fibrosis

Glutamine metabolism plays an essential role in cell growth, and glutamate dehydrogenase (GDH) is a key enzyme. GDH promotes the metabolism of glutamate and glutamine to generate ATP, which is profoundly increased in multiple human cancers. Through in vitro and in vivo experiments, we verified that the small-molecule GDH inhibitor EGCG slowed the progression of fibrosis by inhibiting GDH enzyme activity and glutamine metabolism. SIRT4 is a mitochondrial enzyme with NAD that promotes ADP ribosylation and downregulates GDH activity. The role of SIRT4 in liver fibrosis and the related mechanisms are unknown. In this study, we measured the expression of SIRT4 and found that it was downregulated in liver fibrosis. Modest overexpression of SIRT4 protected the liver from fibrosis by inhibiting the transformation of glutamate to 2-ketoglutaric acid (α-KG) in the tricarboxylic acid cycle (TCA), thereby reducing the proliferative activity of hepatic stellate cells (HSCs). Collectively, our study reveals that SIRT4 controls GDH enzyme activity and expression, targeting glutamine metabolism in HSCs and alleviating liver fibrosis.

Activated Hepatic Stellate Cells Promote the M1 to M2 Macrophage Transformation and Liver Fibrosis by Elevating the Histone Acetylation Level

Liver fibrosis results from the formation of fibrous scars of hepatic stellate cells by various chronic liver diseases. Considering that the liver is the most important metabolic organ in the human body, exploring the metabolic characteristics of liver fibrosis is expected to discover new markers and therapeutic targets. In this study, we first used mouse model to verify that both lactate content and histone acetylation levels were significantly increased in hepatic fibrosis mice. At the same time, it was confirmed that activated hepatic stellate cells (HSCs) cocultured with M1 macrophages can promote their transformation into M2 macrophages in hepatic stellate cell line and primary hepatic stellate cells. In addition, the addition of lactic acid to the medium in which M1 cells are cultured can promote their transformation into M2 macrophages. Therefore, we concluded that activated HSCs can promote the transformation of M1 to M2 macrophages through lactate accumulation, thereby causing liver fibrosis.

Proteomic analysis of hepatic fibrosis induced by a high starch diet in largemouth bass (Micropterus salmoides)

Largemouth bass is sensitive to the dietary starch level and excess starch can induce metabolic liver diseases (MLD). Hepatic fibrosis is a typical pathological phenotype of MLD in largemouth bass, but the molecular basis underlying is largely unclear. This study fed fish with a low or high starch diet for 4 weeks. Liver tissues with or without fibrotic symptoms were recognized through histopathological and molecular markers analysis of hepatic fibrosis, following TMT Quantitative proteomics and conducted Parallel Reaction Monitoring (PRM) analyses. 2455 differentially expressed proteins with 1618 up-regulated and 837 down-regulated were identified in this study. In GO terms, up-regulated proteins were correlated with cytoskeleton organization, supramolecular fiber, cytoskeleton protein binding, and actin-binding, while down-regulated proteins were involved in mainly metabolism-related processes, and molecular binding activity. Down-regulated proteins were enriched in 63 KEGG pathways and concentrated in metabolism-related pathways, especially glucose, lipid, and amino acid metabolism. 70 KEGG pathways of up-regulated proteins mainly included immunity and inflammation-related pathways. The expression trends of 11 differentially expressed proteins were consistent with proteome results by PRM analysis. In conclusion, the development of hepatic fibrosis induced by high starch may be related to multi-signaling pathways, metabolism processes, and targets, which provides important data for further study on revealing the molecular mechanism of hepatic fibrosis.

Perivascular adipose tissue in autoimmune rheumatic diseases

Perivascular adipose tissue (PVAT) resides at the outermost boundary of the vascular wall, surrounding most conduit blood vessels, except for the cerebral vessels, in humans. A growing body of evidence suggests that inflammation localized within PVAT may contribute to the pathogenesis of cardiovascular disease (CVD). Patients with autoimmune rheumatic diseases (ARDs), e.g., systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), psoriasis, etc., exhibit heightened systemic inflammation and are at increased risk for CVD. Data from clinical studies in patients with ARDs support a linkage between dysfunctional adipose tissue, and PVAT in particular, in disease pathogenesis. Here, we review the data linking PVAT to the pathogenesis of CVD in patients with ARDs, focusing on the role of novel PVAT imaging techniques in defining disease risk and responses to biological therapies.

Plasma metabolomic profiling reflects the malnourished and chronic inflammatory state in recessive dystrophic epidermolysis bullosa

BACKGROUND

Recessive dystrophic epidermolysis bullosa (RDEB) is a hereditary blistering disorder characterized by skin fragility, chronic inflammation, malnutrition, and fibrosis. Metabolomics is an emerging investigative field that helps elucidate disease pathophysiology and identify biomarkers. However, previous metabolomic studies in RDEB are limited.

OBJECTIVE

To investigate the plasma metabolomic profiles in RDEB patients.

METHODS

We recruited 10 RDEB patients and 10 age-/gender-matched healthy controls. Peripheral blood samples were collected and plasma metabolomic profiling was performed by LC-MS/MS analysis. MS data processing and compound identification were executed by MS-DIAL. Enrichment analysis was performed by MetaboAnalyst 5.0.

RESULTS

Metabolomic analyses demonstrated that most amino acid levels were downregulated in RDEB patients, and the extent of insufficiency correlated with clinical severity. Several metabolites were dysregulated in RDEB, including glutamine and glutamate metabolism, tryptophan-to-kynurenine ratio, phenylalanine-to-tyrosine ratio, and succinate accumulation.

LIMITATIONS

The study was limited by small case numbers and the unrepresentativeness of a single time-point blood sample.

CONCLUSION

Our study demonstrated the altered metabolomic profiles in RDEB, reflecting the disease severity, the chronic inflammatory and malnourished status, while the fibrotic signatures were not evident.

MicroRNA-15a inhibits hepatic stellate cell activation and proliferation via targeting SRY-box transcription factor 9

Accumulating research have indicated that microRNAs are associated with the progression of hepatic fibrosis (HF). Nevertheless, the biological role and function of microRNA (miR)-15a in HF are still unknown. Our data revealed that miR-15a expression was decreased in TGF-β1-treated LX-2 cells and CCl₄-induced mouse model. Additionally, miR-15a could directly target the 3’‑untranslated region of SRY-box transcription factor 9 (SOX9) to inhibit its expression. miR-15a overexpression attenuated the viability and invasion, but enhanced apoptosis in LX-2 cells. However, miR-15a knockdown had the opposite effects. Interestingly, SOX9 overexpression reversed the changes in cell viability, invasion and apoptosis mediated by miR-15a overexpression. Moreover, the miR-15a overexpression-mediated collagen I and alpha smooth muscle actin (a-SMA) downregulation were reversed by SOX9 overexpression. Overall, miR-15a could inhibit LX-2 cell viability and HF pathogenesis by targeting SOX9 in vitro and in vivo.

Identification of key genes associated with the progression of liver fibrosis to hepatocellular carcinoma based on iTRAQ proteomics and GEO database

INTRODUCTION AND OBJECTIVE

Liver fibrosis (LF) often leads to cirrhosis and even hepatocellular carcinoma (HCC), but the molecular mechanism remains unclear. The aims of the present study were to identify potential biomarkers for the progression of LF to HCC and explore the associated molecular mechanisms.

MATERIALS AND METHODS

The isobaric tags for relative and absolute quantitation (iTRAQ) was used to detect changes in the protein expression profiles of liver tissues and to screen the differentially expressed proteins (DEPs). The differentially expressed genes (DEGs) of LF rats and patients were screened by Gene Expression Database (GEO). Subsequently, the clinicopathological analysis of the overlapping genes in different pathological stages in HCC patients based on GEPIA database was conducted.

RESULTS

iTRAQ proteomic analysis revealed 689, 749 and 585 DEPs in the 6W, 8W and 12W groups, respectively. ALDH2, SLC27A5 and ASNS were not only the DEPs found in rats with LF with different stages but were also the DEGs related to the pathological stages and survival in patients with HCC.

CONCLUSIONS

ALDH2, SLC27A5 and ASNS were the potential biomarkers associated with the progression of LF to HCC.

Convalescent Pigs: Liver and Muscle Examination

Comparative studies of muscle tissue and liver of pigs recovered from intracerebral hematoma were carried out using proteomics and histology methods. The absence of pathological changes in the muscles of animals during the accumulation of proteins with molecular weights from 70 to 15 kDa in the muscles of the limbs, from 50 to 20 kDa in the muscles of the back was established. At the same time, destructive changes in the structure of the liver tissue of convalescents were revealed during the accumulation of proteins with masses less than 20 kDa. Thus, it has been shown that in the long-term period after parenchymal hemorrhage in the brain, the consequences of hemorrhagic transformation persist.

Bmal1 inhibits phenotypic transformation of hepatic stellate cells in liver fibrosis via IDH1/α-KG-mediated glycolysis

Hepatic stellate cells (HSCs) play an important role in the initiation and development of liver fibrogenesis, and abnormal glucose metabolism is increasingly being considered a crucial factor controlling phenotypic transformation in HSCs. However, the role of the factors affecting glycolysis in HSCs in the experimental models of liver fibrosis has not been completely elucidated. In this study, we showed that glycolysis was significantly enhanced, while the expression of brain and muscle arnt-like protein-1 (Bmal1) was downregulated in fibrotic liver tissues of mice, primary HSCs, and transforming growth factor-β1 (TGF-β1)-induced LX2 cells. Overexpression of Bmal1 in TGF-β1-induced LX2 cells blocked glycolysis and inhibited the proliferation and phenotypic transformation of activated HSCs. We further confirmed the protective effect of Bmal1 in liver fibrosis by overexpressing Bmal1 from hepatic adeno-associated virus 8 in mice. In addition, we also showed that the regulation of glycolysis by Bmal1 is mediated by the isocitrate dehydrogenase 1/α-ketoglutarate (IDH1/α-KG) pathway. Collectively, our results indicated that a novel Bmal1-IDH1/α-KG axis may be involved in regulating glycolysis of activated HSCs and might hence be used as a therapeutic target for alleviating liver fibrosis.

Identification and Validation of Novel Serum Autoantibodies Biomarkers for Staging Liver Fibrosis in Patients With Chronic Hepatitis B

Aim: Liver fibrosis monitoring is essential in patients with chronic hepatitis B (CHB). However, less robust, noninvasive diagnostic methods for staging liver fibrosis, other than liver biopsy, are available. Our previous study demonstrated a panel of cellular proteins recognized by autoantibodies that may have potential value in discrimination of CHB and liver cirrhosis. We aim to assess the diagnostic value of these serum autoantibodies for staging liver fibrosis.

Methods: Candidate autoantigens were screened and assessed by microarray analysis in 96 healthy controls and 227 CHB patients with pre-treatment biopsy-proven METAVIR fibrosis score, comprising 69, 115, and 43 cases with S0-1, S2-3, and S4 stages, respectively. Autoantibodies with potential diagnostic value for staging liver fibrosis were verified by enzyme-linked immunosorbent assays (ELISA). Receiver operating characteristic curve was conducted to evaluate autoantibody performance.

Results: Microarray analysis identified autoantigens CENPF, ACY1, HSPA6, and ENO1 with potential diagnostic value for liver fibrosis staging, among which CENPF and ACY1 were validated using ELISA. CENPF and ACY1 autoantibodies had area under the curve values of 0.746 and 0.685, 58.14 and 74.42% sensitivity, and 88.41 and 60.87% specificity, respectively, for discriminating liver fibrosis stages S4 and S0-1. The prevalence of CENPF and ACY1 autoantibodies was not correlated with age, sex or level of inflammation.

Conclusions: Autoimmune responses may be elicited during progression of liver fibrosis, and serum autoantibodies may be a valuable biomarker for staging liver fibrosis deserving of further study.

Identification of Molecular Subgroups in Liver Cirrhosis by Gene Expression Profiles

Background: Liver cirrhosis is characterized by high mortality, bringing a serious health and economic burden to the world. The clinical manifestations of liver cirrhosis are complex and heterogeneous. According to subgroup characteristics, identifying cirrhosis has become a challenge. Objectives: The purpose of this study was to evaluate the difference between different subgroups of cirrhosis. The ultimate goal of research on these different phenotypes was to discover groups of patients with unique treatment characteristics, and formulate targeted treatment plans that improve the prognosis of the disease and improve the patients’ quality of life. Methods: We obtained the relevant gene chip by searching the gene expression omnibus (GEO) database. According to the gene expression profile, 79 patients with liver cirrhosis were divided into four subgroups, which showed different expression patterns. Therefore, we used weighted gene coexpression network analysis (WGCNA) to find differences between subgroups. Results: The characteristics of the WGCNA module indicated that subjects in subgroup I might exhibit inflammatory characteristics; subjects in subgroup II might exhibit metabolically active characteristics; arrhythmogenic right ventricular cardiomyopathy and neuroactive ligand-receptive somatic interaction pathways were significantly enriched in subgroup IV. We did not find a significantly upregulated pathway in the third subgroup. Conclusions: In this study, a new type of clinical phenotype classification of liver cirrhosis was derived by consensus clustering. This study found that patients in different subgroups may have unique gene expression patterns. This new classification method helps researchers explore new treatment strategies for cirrhosis based on clinical phenotypic characteristics.

An Integrated Fibrosis Signature for Predicting Survival and Immunotherapy Efficacy of Patients With Hepatocellular Carcinoma

Introduction: Fibrosis, a primary cause of hepatocellular carcinoma (HCC), is intimately associated with inflammation, the tumor microenvironment (TME), and multiple carcinogenic pathways. Currently, due to widespread inter- and intra-tumoral heterogeneity of HCC, the efficacy of immunotherapy is limited. Seeking a stable and novel tool to predict prognosis and immunotherapy response is imperative. Methods: Using stepwise Cox regression, least absolute shrinkage and selection operator (LASSO), and random survival forest algorithms, the fibrosis-associated signature (FAIS) was developed and further validated. Subsequently, comprehensive exploration was conducted to identify distinct genomic alterations, clinical features, biological functions, and immune landscapes of HCC patients. Results: The FAIS was an independent prognostic predictor of overall survival and recurrence-free survival in HCC. In parallel, the FAIS exhibited stable and accurate performance at predicting prognosis based on the evaluation of Kaplan-Meier survival curves, receiver operator characteristic curves, decision curve analysis, and Harrell's C-index. Further investigation elucidated that the high-risk group presented an inferior prognosis with advanced clinical traits and a high mutation frequency of TP53, whereas the low-risk group was characterized by superior CD8⁺ T cell infiltration, a higher TIS score, and a lower TIDE score. Additionally, patients in the low-risk group might yield more benefits from immunotherapy. Conclusion: The FAIS was an excellent scoring system that could stratify HCC patients and might serve as a promising tool to guide surveillance, improve prognosis, and facilitate clinical management.

Adipose tissue and adipose secretome in systemic sclerosis

PURPOSE OF REVIEW

Adipose tissue is closely associated with systemic sclerosis (SSc)-pathology, both anatomically and functionally. This review focuses on local effects of adipocytes in the context of adipose to mesenchymal transdifferentiation (AMT), effects of the adipose stromal vascular fraction on SSc pathogenesis and systemic effects of adipose tissue secretome.

RECENT FINDINGS

Novel populations of fibroblasts evolving from adipose tissue were identified- for example COL11+ cancer-associated fibroblasts differentiated from adipose-derived stromal cells. Lipofibroblasts in human lungs were described using nonconventional markers that allow more effective population identification. These findings could make an important contribution to further clarification of adipocyte involvement in SSc.Recent studies confirmed that lipolysis contributes to fibrogenesis through AMT differentiation and release of fatty acids (FA). Unbalanced metabolism of FA has been reported in several studies in SSc. Other adipose tissue secretome molecules (e.g. lysophosphatidic acid), novel adipokines and extracellular vesicles from adipose mesenchymal stem cells make important contributions to the pro-/antifibrotic balance.

SUMMARY

There is a growing evidence of important contribution of adipose tissue and its secretome to SSc pathogenesis. Novel techniques such as single-cell RNA sequencing (scRNAseq) and metabolomics, albeit challenging to use in adipose tissue, will provide further evidence.

Decoupled Glucose and Lipid Metabolic Recovery after Viral Clearance in Direct-Acting Antiviral-Treated HCV Patients: A 3-Year Prospective Cohort Study

BACKGROUND/AIM

The recovery pattern of hepatitis C virus (HCV)-associated metabolic alteration after sustained virological response (SVR) following direct-acting antivirals (DAAs) remains elusive.

METHODS

A prospective cohort study of chronic HCV-infected (CHC) patients (n = 415) receiving DAAs (n = 365) was conducted. Metabolic profiles were examined in SVR patients (n = 360) every 3-6 months after therapy and compared with those of sex- and age-matched controls (n = 470).

RESULTS

At baseline, of 415, 168 (40.5%) had insulin resistance (IR). The following were associated: levels of high-density lipoprotein cholesterol (HDL-C), triglycerides (TGs), HCV RNA, fibrosis-4 score, and interferon-λ3-rs12979860 genotype with total cholesterol (TC) levels; and TG levels and BMI with HOMA-IR. Over a 3-year follow-up, in SVR patients, BMI and TC levels and TG/HDL-C ratios increased from baseline, while HOMA-IR trended downward by 72 weeks after therapy and then increased. The increased HDL-C levels began to decrease after 72 weeks after therapy. TC and HOMA-IR were negatively associated with each other until 24 weeks after therapy. Earlier increases in BMI and decreases in HOMA-IR were noted in SVR patients with than in those without baseline IR. Compared with controls, in the subgroup without baseline IR, SVR patients had increased BMI and HOMA-IR levels. Metabolic profiles were similar between SVR patients and controls in the subgroup with baseline IR.

CONCLUSIONS

In SVR patients treated with DAAs, the recovery of altered lipid and glucose metabolism was not coupled until 72-week post-therapy, when HOMA-IR reached its nadir. SVR patients with baseline IR recovered from HCV-associated metabolic alterations earlier than those without baseline IR.

Targeting fatty acid metabolism for fibrotic disorders

Fibrosis is defined by abnormal accumulation of extracellular matrix, which can affect virtually every organ system under diseased conditions. Fibrotic tissue remodeling often leads to organ dysfunction and is highly associated with increased morbidity and mortality. The disease burden caused by fibrosis is substantial, and the medical need for effective antifibrotic therapies is essential. Significant progress has been made in understanding the molecular mechanism and pathobiology of fibrosis, such as transforming growth factor-β (TGF-β)-mediated signaling pathways. However, owing to the complex and dynamic properties of fibrotic disorders, there are currently no therapeutic options that can prevent or reverse fibrosis. Recent studies have revealed that alterations in fatty acid metabolic processes are common mechanisms and core pathways that play a central role in different fibrotic disorders. Excessive lipid accumulation or defective fatty acid oxidation is associated with increased lipotoxicity, which directly contributes to the development of fibrosis. Genetic alterations or pharmacologic targeting of fatty acid metabolic processes have great potential for the inhibition of fibrosis development. Furthermore, mechanistic studies have revealed active interactions between altered metabolic processes and fibrosis development. Several well-known fibrotic factors change the lipid metabolic processes, while altered metabolic processes actively participate in fibrosis development. This review summarizes the recent evidence linking fatty acid metabolism and fibrosis, and provides new insights into the pathogenesis of fibrotic diseases for the development of drugs for fibrosis prevention and treatment.

Amino Acid Profile in 18 Patients with Rheumatic Diseases Treated with Glucocorticoids and BCAAs

The administration of glucocorticoids to patients with rheumatic diseases often results in glucocorticoid-induced myopathy. We previously found that administration of branched-chain amino acids (BCAA) to such patients improves the loss of skeletal muscle, however, their individual differences were often observed. The present study, therefore, aims to identify specific parameters associated with BCAA-induced increases in skeletal muscle mass. Eighteen patients with rheumatic diseases treated with prednisolone were randomly assigned to receive additional BCAAs for 12 wk. Serum biochemistry, plasma fibroblast growth factor (FGF) 19 and 21, and plasma and urinary amino acid concentrations were assessed. The relationship between these parameters and the cross-sectional area (CSA) of the biceps femoris (slow-twitch muscle) and rectus femoris (fast-twitch muscle) was assessed using computed tomography. BCAA supplementation increased serum levels of creatinine and albumin and decreased ammonia and urinary 3-methylhistidine levels. With or without BCAA supplementation, each plasma amino acid concentration decreased during the study period, but the decrease was lower in patients receiving BCAA. Interestingly, a positive correlation was observed between plasma isoleucine, aspartate, and glutamate concentrations and improvement in the biceps femoris muscle atrophy. Plasma amino acid concentrations in patients with rheumatic diseases treated with glucocorticoids decreased despite tapering the dose of glucocorticoids, with a smaller decrease in the BCAA-treated group. Plasma BCAA, aspartic acid, and glutamate concentrations correlated positively with the rate of improvement in biceps femoris muscle atrophy, suggesting that these amino acids are associated with the BCAA-induced increase in muscle mass.

A Cross-Platform Metabolomics Comparison Identifies Serum Metabolite Signatures of Liver Fibrosis Progression in Chronic Hepatitis C Patients

Metabolomics offers new insights into disease mechanisms that is enhanced when adopting orthogonal instrumental platforms to expand metabolome coverage, while also reducing false discoveries by independent replication. Herein, we report the first inter-method comparison when using multisegment injection-capillary electrophoresis-mass spectrometry (MSI-CE-MS) and nuclear magnetic resonance (NMR) spectroscopy for characterizing the serum metabolome of patients with liver fibrosis in chronic hepatitis C virus (HCV) infection (n = 20) and non-HCV controls (n = 14). In this study, 60 and 30 serum metabolites were detected frequently (>75%) with good technical precision (median CV < 10%) from serum filtrate samples (n = 34) when using standardized protocols for MSI-CE-MS and NMR, respectively. Also, 20 serum metabolite concentrations were consistently measured by both methods over a 500-fold concentration range with an overall mean bias of 9.5% (n = 660). Multivariate and univariate statistical analyses independently confirmed that serum choline and histidine were consistently elevated (p < 0.05) in HCV patients with late-stage (F2-F4) as compared to early-stage (F0-F1) liver fibrosis. Overall, the ratio of serum choline to uric acid provided optimal differentiation of liver disease severity (AUC = 0.848, p = 0.00766) using a receiver operating characteristic curve, which was positively correlated with liver stiffness measurements by ultrasound imaging (r = 0.606, p = 0.0047). Moreover, serum 5-oxo-proline concentrations were higher in HCV patients as compared to non-HCV controls (F = 4.29, p = 0.0240) after adjustment for covariates (age, sex, BMI), indicative of elevated oxidative stress from glutathione depletion with the onset and progression of liver fibrosis. Both instrumental techniques enable rapid yet reliable quantification of serum metabolites in large-scale metabolomic studies with good overlap for biomarker replication. Advantages of MSI-CE-MS include greater metabolome coverage, lower operating costs, and smaller sample volume requirements, whereas NMR offers a robust platform supported by automated spectral and data processing software.

Combination therapy of Juzentaihoto and mesenchymal stem cells attenuates liver damage and regresses fibrosis in mice

Background

Liver cirrhosis is an end-stage multiple liver disease. Mesenchymal stem cells (MSCs) are an attractive cell source for reducing liver damage and regressing fibrosis; additional therapies accompanying MSCs can potentially enhance their therapeutic effects. Kampo medicines exhibit anti-inflammatory and anti-oxidative effects. Here, we investigated the therapeutic effect of MSCs combined with the Kampo medicine Juzentaihoto (JTT) as a combination therapy in a carbon tetrachloride (CCl4)-induced cirrhosis mouse model.

Methods

C57BL/6 mice were administered JTT (orally) and/or MSCs (one time, intravenously). The levels of liver proteins were measured in the sera. Sirius Red staining and hydroxyproline quantitation of hepatic tissues and immune cells were conducted, and their associated properties were evaluated. Liver metabolomics of liver tissues was performed.

Results

JTT monotherapy attenuated liver damage and increased serum albumin level, but it did not effectively induce fibrolysis. JTT rapidly reduced liver damage, in a dose-dependent manner, after a single-dose CCl4 administration. Furthermore, JTT-MSC combination therapy attenuated liver damage, improved liver function, and regressed liver fibrosis. The combination increased the CD4+/CD8+ ratio. JTT had stronger effects on NK and regulatory T cell induction, whereas MSCs more strongly induced anti-inflammatory macrophages. The combination therapy further induced anti-inflammatory macrophages. JTT normalized lipid mediators, and tricarboxylic acid cycle- and urea cycle-related mediators effectively.

Conclusions

The addition of JTT enhanced the therapeutic effects of MSCs; this combination could be a potential treatment option for cirrhosis.

•

Juzentaihoto (JTT) enhanced the therapeutic effects of mesenchymal stem cells (MSCs).

•

JTT induced NK and regulatory T cells, whereas MSCs induced anti-inflammatory macrophages.

•

JTT normalized lipid mediators, the tricarboxylic acid cycle, and urea cycle-related mediators.

•

This combination could be a potential treatment option against cirrhosis therapy.

Critical role of triglycerides for adiponectin levels in hepatitis C: a joint study of human and HCV core transgenic mice

Background

Both hepatitis C virus (HCV) infection and adiponectin are critically involved in metabolism. The reversal and associations of altering adiponectin levels after sustained virological responses (SVRs) following direct-acting antivirals (DAA) in HCV-infected patients remained elusive.

Methods

A joint study was conducted in a prospective cohort of 427 HCV-infected patients and a line of HCV core transgenic mice.

Results

Of 427, 358 had completed a course of DAA therapy and 353 had SVRs. At baseline, male sex (95% CI β: − 1.44 to − 0.417), estimated glomerular filtration rate (eGFR) (− 0.025 to − 0.008), triglycerides (− 0.015 to − 0.005), and fibrosis-4 levels (0.08–0.297) were associated with adiponectin levels; BMI (0.029–0.327) and triglycerides levels (0.01–0.03) were associated with homeostatic model assessment for insulin resistance (HOMA-IR) in HCV-infected patients. At 24-week post-therapy, in SVR patients, male sex (− 1.89 to − 0.5) and eGFR (− 0.02 to − 0.001) levels were associated with adiponectin levels, levels of BMI (0.094–0.335) and alanine transaminase (0.018–0.078) were associated with HOMA-IR; compared with baseline levels, adiponectin levels decreased (6.53 ± 2.77 vs. 5.45 ± 2.56 μg/mL, p < 0.001). In 12-month-old HCV core transgenic mice with hepatic steatosis, triglyceride levels (0.021–0.111) were associated with adiponectin levels, and hepatic adipopnectin expression was comparable with that of control mice.

Conclusions

Triglycerides and hepatic fibrosis are associated with HCV-specific alteration of adiponectin levels, and adiponectin may affect insulin sensitivity through triglycerides during HCV infection. In DAA-treated patients, after SVR, adiponectin levels decreased and the linking function of triglycerides between adiponectin and insulin sensitivity vanished. Moreover, HCV core with hepatic steatosis might affect extrahepatic adiponectin expression through triglycerides.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00445-5.

Staging Liver Fibrosis: Comparison of Native T1 Mapping, T2 Mapping, and T1ρ: An Experimental Study in Rats With Bile Duct Ligation and Carbon Tetrachloride at 11.7 T MRI

BACKGROUND

T1, T2, and T1ρ might be potential biomarkers for assessing liver fibrosis. However, few studies reported the value of them in different animal models.

PURPOSE

To investigate and compare the performances of T1, T2, and T1ρ for noninvasively staging liver fibrosis in bile duct ligation (BDL) or carbon tetrachloride (CCl₄ ) model.

STUDY TYPE

Prospective animal model.

SUBJECTS

Liver fibrosis was induced by BDL or injection of CCl₄ in 120 rats.

FIELD STRENGTH/SEQUENCE

11.7 T, T1 mapping with 10 repetition times, T2 mapping with 32 echo times, and T1ρ with 10 spin-lock times.

ASSESSMENT

T1, T2, and T1ρ were measured and correlated with liver fibrosis stages, as well as the degree of inflammation, steatosis, iron deposition, and the expression of cytokeratin 19. The discriminative performance of T1, T2, and T1ρ for staging liver fibrosis was compared.

STATISTICAL TESTS

One-way analysis of variance (ANOVA), Spearman's correlation analysis, factorial design ANOVA, and receiver operating characteristic curves (P < 0.05 was considered statistically significant).

RESULTS

T1, T2, and T1ρ (BDL: rho = 0.73, 0.85, 0.68; CCl₄ : rho = 0.80, 0.29, 0.61) were significantly correlated with liver fibrosis stages, while there was no significant difference in T2 among stage F0-F4 in the CCl₄ model (P = 0.204). The area under the curves (AUCs) range of T1, T2, and T1ρ for predicting ≥F1, ≥F2, ≥F3, and F4 were 0.76-0.95, 0.89-0.98, and 0.80-0.94 in the CCl₄ model. For the CCl₄ model, the AUCs range of T1, T2, and T1ρ for predicting ≥F1, ≥F2, ≥F3, and F4 were 0.83-0.95, 0.61-0.74, and 0.73-0.89, respectively. T2 had significantly higher AUC in the BDL model than CCl₄ model for diagnosing liver fibrosis.

DATA CONCLUSION

The most sensitive and accurate method for staging liver fibrosis appeared to be T1 in our animal models followed by T1ρ. T2 may not be suitable for evaluating liver fibrosis.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 2.

Metabolic Landscape of the Mouse Liver by Quantitative 31 P Nuclear Magnetic Resonance Analysis of the Phosphorome

BACKGROUND AND AIMS

The liver plays a central role in all metabolic processes in the body. However, precise characterization of liver metabolism is often obscured by its inherent complexity. Phosphorylated metabolites occupy a prominent position in all anabolic and catabolic pathways. Here, we develop a ³¹ P nuclear magnetic resonance (NMR)-based method to study the liver "phosphorome" through the simultaneous identification and quantification of multiple hydrophilic and hydrophobic phosphorylated metabolites.

APPROACH AND RESULTS

We applied this technique to define the metabolic landscape in livers from a mouse model of the rare disease disorder congenital erythropoietic porphyria (CEP) as well as two well-known murine models of nonalcoholic steatohepatitis: one genetic, methionine adenosyltransferase 1A knockout mice, and the other dietary, mice fed a high-fat choline-deficient diet. We report alterations in the concentrations of phosphorylated metabolites that are readouts of the balance between glycolysis, gluconeogenesis, the pentose phosphate pathway, the tricarboxylic acid cycle, and oxidative phosphorylation and of phospholipid metabolism and apoptosis. Moreover, these changes correlate with the main histological features: steatosis, apoptosis, iron deposits, and fibrosis. Strikingly, treatment with the repurposed drug ciclopirox improves the phosphoromic profile of CEP mice, an effect that was mirrored by the normalization of liver histology.

CONCLUSIONS

In conclusion, these findings indicate that NMR-based phosphoromics may be used to unravel metabolic phenotypes of liver injury and to identify the mechanism of drug action.

Comprehensive Multi-omics Analysis Reveals Mitochondrial Stress as a Central Biological Hub for Spaceflight Impact

Spaceflight is known to impose changes on human physiology with unknown molecular etiologies. To reveal these causes, we used a multi-omics, systems biology analytical approach using biomedical profiles from fifty-nine astronauts and data from NASA's GeneLab derived from hundreds of samples flown in space to determine transcriptomic, proteomic, metabolomic, and epigenetic responses to spaceflight. Overall pathway analyses on the multi-omics datasets showed significant enrichment for mitochondrial processes, as well as innate immunity, chronic inflammation, cell cycle, circadian rhythm, and olfactory functions. Importantly, NASA's Twin Study provided a platform to confirm several of our principal findings. Evidence of altered mitochondrial function and DNA damage was also found in the urine and blood metabolic data compiled from the astronaut cohort and NASA Twin Study data, indicating mitochondrial stress as a consistent phenotype of spaceflight.

Systemic Perturbations in Amine and Kynurenine Metabolism Associated with Acute SARS-CoV-2 Infection and Inflammatory Cytokine Responses

We performed quantitative metabolic phenotyping of blood plasma in parallel with cytokine/chemokine analysis from participants who were either SARS-CoV-2 (+) (n = 10) or SARS-CoV-2 (-) (n = 49). SARS-CoV-2 positivity was associated with a unique metabolic phenotype and demonstrated a complex systemic response to infection, including severe perturbations in amino acid and kynurenine metabolic pathways. Nine metabolites were elevated in plasma and strongly associated with infection (quinolinic acid, glutamic acid, nicotinic acid, aspartic acid, neopterin, kynurenine, phenylalanine, 3-hydroxykynurenine, and taurine; p < 0.05), while four metabolites were lower in infection (tryptophan, histidine, indole-3-acetic acid, and citrulline; p < 0.05). This signature supports a systemic metabolic phenoconversion following infection, indicating possible neurotoxicity and neurological disruption (elevations of 3-hydroxykynurenine and quinolinic acid) and liver dysfunction (reduction in Fischer's ratio and elevation of taurine). Finally, we report correlations between the key metabolite changes observed in the disease with concentrations of proinflammatory cytokines and chemokines showing strong immunometabolic disorder in response to SARS-CoV-2 infection.

Noninvasive stratification of nonalcoholic fatty liver disease by whole transcriptome cell-free mRNA characterization

Hepatic fibrosis stage is the most important determinant of outcomes in patients with nonalcoholic fatty liver disease (NAFLD). There is an urgent need for noninvasive tests that can accurately stage fibrosis and determine efficacy of interventions. Here, we describe a novel cell-free (cf)-mRNA sequencing approach that can accurately and reproducibly profile low levels of circulating mRNAs and evaluate the feasibility of developing a cf-mRNA-based NAFLD fibrosis classifier. Using separate discovery and validation cohorts with biopsy-confirmed NAFLD (n = 176 and 59, respectively) and healthy subjects (n = 23), we performed serum cf-mRNA RNA-Seq profiling. Differential expression analysis identified 2,498 dysregulated genes between patients with NAFLD and healthy subjects and 134 fibrosis-associated genes in patients with NAFLD. Comparison between cf-mRNA and liver tissue transcripts revealed significant overlap of fibrosis-associated genes and pathways indicating that the circulating cf-mRNA transcriptome reflects molecular changes in the livers of patients with NAFLD. In particular, metabolic and immune pathways reflective of known underlying steatosis and inflammation were highly dysregulated in the cf-mRNA profile of patients with advanced fibrosis. Finally, we used an elastic net ordinal logistic model to develop a classifier that predicts clinically significant fibrosis (F2-F4). In an independent cohort, the cf-mRNA classifier was able to identify 50% of patients with at least 90% probability of clinically significant fibrosis. We demonstrate a novel and robust cf-mRNA-based RNA-Seq platform for noninvasive identification of diverse hepatic molecular disruptions and for fibrosis staging with promising potential for clinical trials and clinical practice.NEW & NOTEWORTHY This work is the first study, to our knowledge, to utilize circulating cell-free mRNA sequencing to develop an NAFLD diagnostic classifier.

The Ameliorative Effects of Fucoidan in Thioacetaide-Induced Liver Injury in Mice

Liver disorders have been recognized as one major health concern. Fucoidan, a sulfated polysaccharide extracted from the brown seaweed Fucus serratus, has previously been reported as an anti-inflammatory and antioxidant. However, the discovery and validation of its hepatoprotective properties and elucidation of its mechanisms of action are still unknown. The objective of the current study was to investigate the effect and possible modes of action of a treatment of fucoidan against thioacetamide (TAA)-induced liver injury in male C57BL/6 mice by serum biochemical and histological analyses. The mouse model for liver damage was developed by the administration of TAA thrice a week for six weeks. The mice with TAA-induced liver injury were orally administered fucoidan once a day for 42 days. The treated mice showed significantly higher body weights; food intakes; hepatic antioxidative enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)); and a lower serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and C-reactive protein (CRP) levels. Additionally, a reduced hepatic IL-6 level and a decreased expression of inflammatory-related genes, such as cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) mRNA was observed. These results demonstrated that fucoidan had a hepatoprotective effect on liver injury through the suppression of the inflammatory responses and acting as an antioxidant. In addition, here, we validated the use of fucoidan against liver disorders with supporting molecular data.

Major ceRNA regulation and key metabolic signature analysis of intervertebral disc degeneration

Background and objective

Intervertebral disc degeneration (IDD) is a complex multifactorial and irreversible pathological process. In IDD, multiple competing endogenous RNAs (ceRNA, including mRNA, lncRNA, and pseudogenes) can compete to bind with miRNAs. However, the potential metabolic signatures in nucleus pulposus (NP) cells remain poorly understood. This study investigated key metabolic genes and the ceRNA regulatory mechanisms in the pathogenesis of IDD based on microarray datasets.

Methods

We retrieved and downloaded four independent IDD microarray datasets from the Gene Expression Omnibus. Combining the predicted interactions from online databases (miRcode, miRDB, miRTarBase, and TargetScan), differentially expressed lncRNAs (DElncRNAs), miRNAs (DEmiRNAs), and mRNAs (DEmRNAs) were identified. A ceRNA network was constructed and annotated using GO and KEGG pathway enrichment analyses. Moreover, we searched the online metabolic gene set and used support vector machine (SVM) to find the critical metabolic DEmRNA(s) and other DERNAs. Differential gene expression was validated with a merged dataset.

Results

A total of 45 DEmRNAs, 36 DElncRNAs, and only one DEmiRNA (miR-338-3p) were identified in the IDD microarray datasets. GO and KEGG pathway enrichment analyses revealed that the DEmRNAs were predominantly enriched in the PI3K-Akt signaling pathway, MAPK signaling pathway, IL-17 signaling pathway, apoptosis, and cellular response to oxidative stress. Based on SVM screening, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFK/FBPase) 2 is the critical metabolic gene with lower expression in IDD, and AC063977.6 is the key lncRNA with lower expression in IDD. The ceRNA hypothesis suggests that AC063977.6, miR-338-3p (high expression), and PFKFB2 are dysregulated as an axis in IDD.

Conclusions

The results suggest that lncRNA AC063977.6 correlate with PFKFB2, the vital metabolic signature gene, via targeting miR-338-3p during IDD pathogenesis. The current study may shed light on unraveling the pathogenesis of IDD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04109-8.

Switching diseased cells from cytosolic aerobic glycolysis to mitochondrial oxidative phosphorylation: A metabolic rhythm regulated by melatonin?

This commentary reviews the concept of the circadian melatonin rhythm playing an essential role in reducing the development of diseases such as solid tumors which adopt cytosolic aerobic glycolysis (Warburg effect) to support their enhanced metabolism. Experimental data show that solid mammary tumors depend on aerobic glycolysis during the day but likely revert to mitochondrial oxidative phosphorylation at night for ATP production. This conversion of diseased cells during the day to a healthier phenotype at night occurs under control of the circulating melatonin rhythm. When the nocturnal melatonin rise is inhibited by light exposure at night, cancer cells function in the diseased state 24/7. The ability of melatonin to switch cancer cells as well as other diseased cells, for example, Alzheimer disease, fibrosis, hyperactivation of macrophages, etc, from aerobic glycolysis to mitochondrial oxidative phosphorylation may be a basic protective mechanism to reduce pathologies.

Integrative Modeling of Quantitative Plasma Lipoprotein, Metabolic, and Amino Acid Data Reveals a Multiorgan Pathological Signature of SARS-CoV-2 Infection

The metabolic effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on human blood plasma were characterized using multiplatform metabolic phenotyping with nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS). Quantitative measurements of lipoprotein subfractions, α-1-acid glycoprotein, glucose, and biogenic amines were made on samples from symptomatic coronavirus disease 19 (COVID-19) patients who had tested positive for the SARS-CoV-2 virus (n = 17) and from age- and gender-matched controls (n = 25). Data were analyzed using an orthogonal-projections to latent structures (OPLS) method and used to construct an exceptionally strong (AUROC = 1) hybrid NMR-MS model that enabled detailed metabolic discrimination between the groups and their biochemical relationships. Key discriminant metabolites included markers of inflammation including elevated α-1-acid glycoprotein and an increased kynurenine/tryptophan ratio. There was also an abnormal lipoprotein, glucose, and amino acid signature consistent with diabetes and coronary artery disease (low total and HDL Apolipoprotein A1, low HDL triglycerides, high LDL and VLDL triglycerides), plus multiple highly significant amino acid markers of liver dysfunction (including the elevated glutamine/glutamate and Fischer's ratios) that present themselves as part of a distinct SARS-CoV-2 infection pattern. A multivariate training-test set model was validated using independent samples from additional SARS-CoV-2 positive patients and controls. The predictive model showed a sensitivity of 100% for SARS-CoV-2 positivity. The breadth of the disturbed pathways indicates a systemic signature of SARS-CoV-2 positivity that includes elements of liver dysfunction, dyslipidemia, diabetes, and coronary heart disease risk that are consistent with recent reports that COVID-19 is a systemic disease affecting multiple organs and systems. Metabolights study reference: MTBLS2014.