Summary
Background
Obesity can influence hepatic mitochondrial function, and cause non‐alcoholic steatohepatitis (NASH). Diagnosis and follow‐up rely on invasive liver biopsy so blood‐based markers ...are urgently required.
Aim
To investigate whether values of circulating metabolites from energy and one‐carbon (1‐C) metabolism may: (a) reflect hepatic mitochondrial flexibility failure and (b) act as NASH biomarkers.
Methods
Patients with severe obesity undergoing bariatric surgery (n = 270) were investigated using quantitative targeted plasma metabolomics. Comparisons were with non‐obese controls without liver disease (n = 50). Obese patients with NASH (n = 53) and without NASH (n = 130) representing extreme groups of liver disease were assessed to test the diagnostic ability of the measured circulating metabolites. Paired liver biopsy and plasma samples from NASH patients were available 1 year post‐surgery and were evaluated to monitor metabolomic changes with liver damage resolution.
Results
We identified correlations between human liver metabolism and obesity. High‐plasma α‐ketoglutarate (α‐KG) and lactate concentrations in NASH patients indicating citric acid cycle replenishment via glutaminolysis might also be a crucial point in NASH onset. Plasma measurements of α‐KG, β‐hydroxybutyrate, pyruvate and oxaloacetate reduced the uncertainty in clinical diagnosis of NASH area under receiver operating characteristic curve (AUC) of 0.826 and predicted NASH resolution without ambiguity (AUC of 0.999).
Conclusion
Changes in plasma mitochondrial metabolites appear to be associated with NASH. These metabolic responses may be dynamically remodelled following resolution of liver damage through massive weight loss.
We investigated alterations in the levels of the antioxidant paraoxonase-1 (PON1) and the lipoprotein profile (analyzed by nuclear magnetic resonance) in patients with lung cancer (LC) or head and ...neck cancer (HNC), and the effects produced thereon by radiotherapy (RT). We included 33 patients with LC and 28 patients with HNC. Before irradiation, and one month after completion of RT, blood samples were obtained. The control group was composed of 50 healthy subjects. Patients had significantly lower serum PON1 activity and concentration before RT than the control group. PON1-related variables were good predictors of the presence of LC or HNC, with analytical sensitivities and specificities greater than 80%. Patients showed a significant increase in the number of particles of all subclasses of very-low-density lipoproteins (large, medium and small). However, these changes were not maintained when adjusted for age, sex, and other clinical and demographic variables. Irradiation was associated with a significant increase in PON1 concentration and, only in patients with HNC, with an increase in high-density lipoprotein-cholesterol concentration. Our results suggest that determinations of the levels of PON1-related variables may constitute good biomarkers for the evaluation of these diseases. Studies with a larger number of patients are needed to fully confirm this hypothesis.
Hepatic alterations, such as in non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are frequently associated with obesity. To investigate the molecular mechanisms of ...these alterations and to identify molecules that could be used as potential therapeutic targets, we investigated the modulation of hepatic indices of oxidative stress and inflammation in obese patients undergoing laparoscopic sleeve gastrectomy (LSG).
Patients (n = 436) attending our obesity clinic underwent LSG for weight loss. We obtained a diagnostic intraoperative liver biopsy, and a sub-cohort (n = 120) agreed to a 1-year follow-up that included donation of blood samples and additional liver biopsies. Selected key molecules in blood and liver tissue were used to investigate the hepatic alterations in obesity, and their response to LSG.
One year post-surgery, the prevalence of diabetes, dyslipidemia and hypertension decreased significantly. LSG improved liver histology features in all patients. Improvement was greater in severe cases of NAFLD including those with steatohepatitis, bridging fibrosis or cirrhosis. Significant pre-surgery differences in plasma, and liver markers of oxidative stress and inflammation (including chemokine C-C motif ligand 2, paraoxonase-1, galectin-3, and sonic hedgehog) were observed between patients with, and those without, NASH; post-surgery indicated consistent improvements in these parameters.
Our study shows that the histology and liver function of patients with morbid obesity are significantly improved after LSG via mechanisms that involve the reduction of oxidative stress and inflammatory processes. These data encourage the use of LSG as a therapeutic option to improve, or resolve, NAFLD.
•NAFLD was frequent and heterogeneous in patients with severe obesity.•Bariatric surgery was associated with remission of NAFLD and NASH.•Oxidative stress and inflammation markers improved following bariatric surgery.•Oxidation and inflammation are key elements in NAFLD progression and remission.
We investigated the alterations in the plasma concentrations of energy-balance-related metabolites in patients with lung (LC) or head & neck (HNC) cancer and the changes on these parameters induced ...by radiotherapy. The study was conducted in 33 patients with non-small cell LC and 28 patients with HNC. We analyzed the concentrations of 17 metabolites involved in glycolysis, citric acid cycle and amino acid metabolism using targeted gas chromatography coupled to quadrupole time-of-flight mass spectrometry. For comparison, a control group of 50 healthy individuals was included in the present study. Patients with LC or HNC had significant alterations in the plasma levels of several energy-balance-related metabolites. Radiotherapy partially normalized these alterations in patients with LC, but not in those with HNC. The measurement of plasma glutamate concentration was an excellent predictor of the presence of LC or HNC, with sensitivity >90% and specificity >80%. Also, associations with disease prognosis were observed with plasma glutamate, amino acids and β-hydroxybutyrate concentrations.
This study analyzed the changes produced in the plasma concentrations of energy-balance-related metabolites in patients with lung cancer or head and neck cancer. The results obtained identified glutamate as the parameter with the highest discrimination capacity between patients and the control group. The relationships between various metabolites and clinical outcomes were also analyzed. These results extend the knowledge of metabolic alterations in cancer, thus facilitating the search for biomarkers and therapeutic targets.
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•Patients with cancer have alterations in energy-balance metabolism.•Plasma glutamate discriminated patients with lung cancer from healthy people.•Similar results were obtained in patients with head & neck cancer.•Radiotherapy did not importantly ameliorate these alterations.•Several metabolites were associated with the clinical outcomes.
Chemokine (C-C motif) ligand 2 (CCL2) has been associated with chronic metabolic diseases. We aimed to investigate whether Ccl2 gene overexpression is involved in the regulation of signaling pathways ...in metabolic organs. Biochemical and histological analyses were used to explore tissue damage in cisgenic mice that overexpressed the Ccl2 gene. Metabolites from energy and one-carbon metabolism in liver and muscle extracts were measured by targeted metabolomics. Western blot analysis was used to explore the AMP-activated protein kinase (AMPK) and mammalian target of rapamycin pathways. Ccl2 overexpression resulted in steatosis, decreased AMPK activity and altered mitochondrial dynamics in the liver. These changes were associated with decreased oxidative phosphorylation and alterations in the citric acid cycle and transmethylation. In contrast, AMPK activity and its downstream mediators were increased in muscle, where we observed an increase in oxidative phosphorylation and increased concentrations of different metabolites associated with ATP synthesis. In conclusion, Ccl2 overexpression induces distinct metabolic alterations in the liver and muscle that affect mitochondrial dynamics and the regulation of energy sensors involved in cell homeostasis. These data suggest that CCL2 may be a therapeutic target in metabolic diseases.
Abstract
Patients with morbid obesity frequently present non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH) associated with pro-atherogenic alterations. Laparoscopic sleeve ...gastrectomy (LSG) is an effective treatment for weight reduction, and for the remission of hepatic alterations. Using
1
H-nuclear magnetic resonance (
1
H-NMR), we investigated the effects of LSG on lipoprotein and glycoprotein profile in patients with morbid obesity and liver disease. We included 154 patients with morbid obesity (49 non-NASH, 54 uncertain NASH, 51 definite NASH). A blood sample was obtained before surgery and, in patients with definite NASH, one year after surgery. Patients with NASH had increased concentrations of medium and small VLDL particles, VLDL and IDL cholesterol concentrations, IDL, LDL, and HDL triglyceride concentrations, and elevated glycoprotein levels. These changes were more marked in patients with type 2 diabetes mellitus. LSG produced significant decreases in the concentration of VLDL particles, VLDL cholesterol and triglycerides, an increase in the concentration LDL particles and LDL cholesterol concentrations, and a decrease in protein glycation. We conclude that patients with obesity and NASH had significant alterations in circulating levels of lipoproteins and glycoproteins that were associated with the severity of the disease. Most of these changes were reversed post-LSG.
Many countries have seen a two-wave pattern in reported cases of coronavirus disease-19 during the 2020 pandemic, with a first wave during spring followed by the current second wave in late summer ...and autumn. Empirical data show that the characteristics of the effects of the virus do vary between the two periods. Differences in age range and severity of the disease have been reported, although the comparative characteristics of the two waves still remain largely unknown. Those characteristics are compared in this study using data from two equal periods of 3 and a half months. The first period, between 15th March and 30th June, corresponding to the entire first wave, and the second, between 1st July and 15th October, corresponding to part of the second wave, still present at the time of writing this article. Two hundred and four patients were hospitalized during the first period, and 264 during the second period. Patients in the second wave were younger and the duration of hospitalization and case fatality rate were lower than those in the first wave. In the second wave, there were more children, and pregnant and post-partum women. The most frequent signs and symptoms in both waves were fever, dyspnea, pneumonia, and cough, and the most relevant comorbidities were cardiovascular diseases, type 2 diabetes mellitus, and chronic neurological diseases. Patients from the second wave more frequently presented renal and gastrointestinal symptoms, were more often treated with non-invasive mechanical ventilation and corticoids, and less often with invasive mechanical ventilation, conventional oxygen therapy and anticoagulants. Several differences in mortality risk factors were also observed. These results might help to understand the characteristics of the second wave and the behaviour and danger of SARS-CoV-2 in the Mediterranean area and in Western Europe. Further studies are needed to confirm our findings.
Hepatic biopsy is the gold standard for staging nonalcoholic fatty liver disease (NAFLD). Unfortunately, accessing the liver is invasive, requires a multidisciplinary team and is too expensive to be ...conducted on large segments of the population. NAFLD starts quietly and can progress until liver damage is irreversible. Given this complex situation, the search for noninvasive alternatives is clinically important. A hallmark of NAFLD progression is the dysregulation in lipid metabolism. In this context, recent advances in the area of machine learning have increased the interest in evaluating whether multi-omics data analysis performed on peripheral blood can enhance human interpretation. In the present review, we show how the use of machine learning can identify sets of lipids as predictive biomarkers of NAFLD progression. This approach could potentially help clinicians to improve the diagnosis accuracy and predict the future risk of the disease. While NAFLD has no effective treatment yet, the key to slowing the progression of the disease may lie in predictive robust biomarkers. Hence, to detect this disease as soon as possible, the use of computational science can help us to make a more accurate and reliable diagnosis. We aimed to provide a general overview for all readers interested in implementing these methods.
Lipids are involved in the interaction between viral infection and the host metabolic and immunological responses. Several studies comparing the lipidome of COVID-19-positive hospitalized patients ...vs. healthy subjects have already been reported. It is largely unknown, however, whether these differences are specific to this disease. The present study compared the lipidomic signature of hospitalized COVID-19-positive patients with that of healthy subjects, as well as with COVID-19-negative patients hospitalized for other infectious/inflammatory diseases.
We analyzed the lipidomic signature of 126 COVID-19-positive patients, 45 COVID-19-negative patients hospitalized with other infectious/inflammatory diseases and 50 healthy volunteers. A semi-targeted lipidomics analysis was performed using liquid chromatography coupled to mass spectrometry. Two-hundred and eighty-three lipid species were identified and quantified. Results were interpreted by machine learning tools.
We identified acylcarnitines, lysophosphatidylethanolamines, arachidonic acid and oxylipins as the most altered species in COVID-19-positive patients compared to healthy volunteers. However, we found similar alterations in COVID-19-negative patients who had other causes of inflammation. Conversely, lysophosphatidylcholine 22:6-sn2, phosphatidylcholine 36:1 and secondary bile acids were the parameters that had the greatest capacity to discriminate between COVID-19-positive and COVID-19-negative patients.
This study shows that COVID-19 infection shares many lipid alterations with other infectious/inflammatory diseases, and which differentiate them from the healthy population. The most notable alterations were observed in oxylipins, while alterations in bile acids and glycerophospholipis best distinguished between COVID-19-positive and COVID-19-negative patients. Our results highlight the value of integrating lipidomics with machine learning algorithms to explore the pathophysiology of COVID-19 and, consequently, improve clinical decision making.
•COVID-19 alters lipid metabolism of the infected host.•We evaluated serum lipidome in controls and patients with or without COVID-19.•A lipidomic signature differentiated patients from controls.•A lipidomic signature differentiated COVID-19 positive from negative patients.
We report a pilot study on the feasibility of determinations of circulating levels of paraoxonase-1 (PON1) and compounds related to energy metabolism as biomarkers for the evaluation of patients with ...rectal cancer (RC), and the effects produced by neoadjuvant radiochemotherapy (NRCT). We studied 32 patients treated with radiotherapy plus capecitabine concomitant chemotherapy and 48 control subjects. We identified pre-NRCT PON1 and α-ketoglutarate as the parameters that best discriminated between RC patients and the control group. Receiver operating characteristics analysis of the combination of the two parameters showed an area under the curve (AUC) of 0.918. Moreover, patients who presented a pathological complete response (pCR) to treatment had lower plasma pre-NRCT valine concentrations (AUC of 0.826). Patients who had a relapse had lower concentrations of succinate (AUC of 0.833). The results of the present study illustrate the usefulness of investigating alterations in oxidative stress and metabolism in RC. Due to the small number of patients studied, our results must be considered preliminary, but they suggest that the determination of circulating levels of PON1 and α-ketoglutarate might be a valuable tool for the early diagnosis of RC, while the determination of valine and succinate might effectively predict pCR and the appearance of relapse.
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