Background: Major depressive disorder (MDD) and bipolar disorder (BD) are psychiatric disorders with overlapping symptoms, leading to high rates of misdiagnosis due to the lack of biomarkers for differentiation. This study aimed to identify metabolic biomarkers in urine samples for diagnosing MDD and BD, as well as to establish unbiased differential diagnostic models. Methods: We utilized a metabolomics approach employing ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) to analyze the metabolic profiles of urine samples from individuals with MDD (n = 50), BD (n = 12), and healthy controls (n = 50). The identification of urine metabolites was verified using MS data analysis tools and online metabolite databases. Results: Two diagnostic panels consisting of a combination of metabolites and clinical indicators were identified-one for MDD and another for BD. The discriminative capacity of these panels was assessed using the area under the receiver operating characteristic (ROC) curve, yielding an area under the curve (AUC) of 0.9084 for MDD and an AUC value of 0.9017 for BD. Conclusions: High-resolution mass spectrometry-based assays show promise in identifying urinary biomarkers for depressive disorders. The combination of urine metabolites and clinical indicators is effective in differentiating healthy controls from individuals with MDD and BD. The metabolic pathway indicating oxidative stress is seen to significantly contribute to depressive disorders.

Abstract Background Schizophrenia (SCZ) patients undergoing antipsychotic treatment demonstrated a high prevalence and harmful effects of metabolic syndrome (MetS), which acted as the major cause of cardiovascular disease. The major clinical challenge is the lack of biomarkers to identify MetS episodes and prevent further damage, while the mechanisms underlying these drug-induced MetS remain unknown. Methods This study divided 173 participants with SCZ into 3 groups (None, High risk, and MetS, consisting of 22, 88, and 63 participants, respectively). The potential biomarkers were searched based on 16S rRNA gene sequence together with metabolism analysis. Logistic regression was used to test the effects of the genus-metabolites panel on early MetS diagnoses. Results A genus-metabolites panel, consisting of Senegalimassilia, sphinganine, dihomo-gamma-linolenoylcholine, isodeoxycholic acid, and MG (0:0/22:5/0:0), which involved in sphigolipid metabolism, fatty acid metabolism, secondary bile acid biosynthesis and glycerolipid metabolism, has a great discrimination efficiency to MetS with an area under the curve (AUC) value of 0.911 compared to the None MetS group (P = 1.08E-8). Besides, Senegalimassilia, 3-Hydroxytetradecanoyl carnitine, isodeoxycholic acid, and DG(TXB2/0:0/2:0) distinguished between subgroups robustly and exhibited a potential correlation with the severity of MetS in patients with SCZ, and may act as the biomarkers for early MetS diagnosis. Conclusions Our multi–omics study showed that one bacterial genus-five lipid metabolites panel is the potential risk factor for MetS in SCZ. Furthermore, Senegalimassilia, 3-Hydroxytetradecanoyl carnitine, isodeoxycholic acid, and DG(TXB2/0:0/2:0) could serve as novel diagnostic markers in the early stage. So, it is obvious that the combination of bacterial genus and metabolites yields excellent discriminatory power, and the lipid metabolism provide new understanding to the pathogenesis, prevention, and therapy for MetS in SCZ.

As one of the most common antipsychotics, olanzapine may cause metabolic-related adverse effects, but it is still unknown how olanzapine alters lipid metabolism. In this study, we found that olanzapine-treated mice showed varying degrees of dyslipidemia, which was particularly pronounced in female mice. Based on ultra-performance liquid chromatography-quadrupole time-of-flight-MS (UPLC-Q-TOF-MS) technology and lipid metabolomics, we mapped the changes in lipid metabolism in olanzapine-treated mice and then compared the changes in lipid metabolism between male and female mice. There were 98 metabolic differentiators between the olanzapine-treated and control groups in females and 79 in males. These metabolites were glycerolipids, glycerophospholipids, fatty amides, and sphingolipids, which are involved in glycerolipid metabolism, glycerophospholipid metabolism, and fatty acid metabolism. These results suggest that olanzapine-induced changes in the levels of lipid metabolites are closely associated with disturbances in lipid metabolic pathways, which may underlie lipemia. This lipidome profiling study not only visualizes changes in lipid metabolism in liver tissue but also provides a foundation for understanding the regulatory pathways and mechanisms involved in olanzapine-induced lipid metabolism disorders. Furthermore, this study demonstrates differences in lipid metabolism between males and females, providing a reference for clinical treatment regimen selection.

OBJECTIVE:Alzheimer's disease (AD) is characterized by the progressive degeneration and damage of neurons in the brain. However, developing an accurate diagnostic assay using blood samples remains a challenge in clinic practice. The aim of this study was to explore senescence-associated secretory phenotypes (SASPs) in peripheral blood using mass spectrometry based multi-omics approach and to establish diagnostic assays for AD. METHODS:This retrospective study included 88 participants, consisting of 29 AD patients and 59 cognitively normal (CN) individuals. Plasma and serum samples were examined using high-resolution mass spectrometry to identify proteomic and metabolomic profiles. Receiver operating characteristic (ROC) analysis was employed to screen biomarkers with diagnostic potential. K-nearest neighbors (KNN) algorithm was utilized to construct a multi-dimensional model for distinguishing AD from CN. RESULTS:Proteomics analysis revealed upregulation of five plasma proteins in AD, including RNA helicase aquarius (AQR), zinc finger protein 587B (ZNF587B), C-reactive protein (CRP), fibronectin (FN1), and serum amyloid A-1 protein (SAA1), indicating their potential for AD classification. Interestingly, KNN-based three-dimensional model, comprising AQR, ZNF587B, and CRP, demonstrated its high accuracy in AD recognition, with evaluation possibilities of 0.941, 1.000, and 1.000 for the training, testing, and validation datasets, respectively. Besides, metabolomics analysis suggested elevated levels of serum phenylacetylglutamine (PAGIn) in AD. INTERPRETATION:The multi-omics outcomes highlighted the significance of the SASPs, specifically AQR, ZNF587B, CRP, and PAGIn, in terms of their potential for diagnosing AD and suggested neuronal aging-associated pathophysiology.

Alpha-hydroxy ceramides are not only the precursors of many complex sphingolipids, also play a major role in membrane homeostasis and cellular signal transduction. However, current research rarely involved quantitative methods for a-hydroxy ceramides, which greatly restricts the study of its biological function. This work aimed to develop a reliable assay for the accurate quantification of a-hydroxy ceramides in vivo study. LC-MS/MS method was developed for the accurate quantification of six a-hydroxy ceramides of Cer(d18:1/16:0(2OH)), Cer(d18:1/ 18:0(2OH)), Cer(d18:1/18:1(2OH)), Cer(d18:1/20:0(2OH)), Cer(d18:1/22:0(2OH)) and Cer(d18:1/24:1(2OH)) in mice serum. This assay was validated with low limit of quantitation of 3.125 ng/mL, a dynamic range of 3.125-400 ng/mL (R2 > 0.99), precision (<15 %), and accuracy (88 % to 115 %). Applying the method to the determination of a-hydroxy ceramides in the serum of sepsis mice, the levels of Cer(d18:1/16:0(2OH)), Cer (d18:1/20:0(2OH)), Cer(d18:1/24:1(2OH)) were significantly elevated in LPS-induced septic as compared to the normal control. In conclusion, this LC-MS method was qualified in a-hydroxy ceramides quantification in vivo and a significant association was found between a-hydroxy ceramides and sepsis.

Few studies have examined the relationship between lipid metabolism and kidney stone formation, particularly the role of key lipid regulatory factors in kidney stone formation. We evaluated the effect of the lipid regulatory factor-peroxisome proliferator-activated receptor alpha on the formation of renal stones in mice by injecting them with glyoxylate followed by treatment with either a peroxisome proliferator-activated receptor alpha agonist fenofibrate or an antagonist GW6471 (GW). Liquid chromatography coupled with trapped ion mobility spectrometry-quadrupole-time-of-flight mass spectrometry-based lipidomics was used to determine the lipid profile in the mouse kidneys. Histological and biochemical analyses showed that the mice injected with glyoxylate exhibited crystal precipitation and renal dysfunction. Crystallization decreased significantly in the fenofibrate group, whereas it increased significantly in the GW group. A total of 184 lipids, including fatty acyls, glycerolipids, glycerophospholipids, and sphingolipids differed significantly between the mice in the model and control groups. Peroxisome proliferator-activated receptor alpha activity negatively correlated with glyoxylate-induced kidney stone formation in mice, which may be related to improved fatty acid oxidation, maintenance of ceramide/complex sphingolipids cycle balance, and alleviation of disorder in phospholipid metabolism.

Renal fibrosis is the pathological repair reaction of the kidney to chronic injury, which is an important process of chronic kidney disease (CKD) progressing to end-stage renal failure. Nephrolithiasis is one of the most common renal diseases, with waist and abdomen pain, hematuria, urinary tract infection, and other clinical symptoms, which can increase the risk of renal fibrosis. Oxalate crystal-induced kidney injury is an early stage of nephrolithiasis; it is of great significance to explore the mechanism for the prevention and treatment of nephrolithiasis. A rodent model of calcium oxalate (CaOx) crystal-induced kidney injury was used in the present study, and a network analysis method combining proteomics and metabolomics was conducted to reveal the mechanism of crystal kidney injury and to provide potential targets for the intervention of nephrolithiasis. Using the metabolomics method based on the UHPLC-Q/TOF-MS platform and the iTRAQ quantitative proteomics method, we screened a total of 244 metabolites and 886 proteins from the kidney tissues that had significant changes in the Crystal group compared with that in the Control group. Then, the ingenuity pathway analysis (IPA) was applied to construct a protein-to-metabolic regulatory network by correlating and integrating differential metabolites and proteins. The results showed that CaOx crystals could induce inflammatory reactions and oxidative stress through Akt, ERK1/2, and P38 MAPK pathways and affect amino acid metabolism and fatty acid β-oxidation to result in kidney injury, thus providing an important direction for the early prevention and treatment of nephrolithiasis.

Osteoporosis (OP) is a systemic bone disease characterized by decreased bone strength, microarchitectural changes in bone tissues, and increased risk of fracture. Its occurrence is closely related to various factors such as aging, genetic factors, living habits, and nutritional deficiencies as well as the disturbance of bone homeostasis. The dysregulation of bone metabolism is regarded as one of the key influencing factors causing OP. Cholesterol oxidation products (COPs) are important compounds in the maintenance of bone metabolic homeostasis by participating in several important biological processes such as the differentiation of mesenchymal stem cells, bone formation in osteoblasts, and bone resorption in osteoclasts. The effects of specific COPs on mesenchymal stem cells are mainly manifested by promoting osteoblast genesis and inhibiting adipocyte genesis. This review aims to elucidate the biological roles of COPs in OP development, starting from the molecular mechanisms of OP, pointing out opportunities and challenges in current research, and providing new ideas and perspectives for further studies of OP pathogenesis.

Apoptosis has been suggested as the first step in the process of conversion of muscle into meat. While a potential role of apoptosis in postmortem proteolysis has been proposed, the underlying mechanisms by which metabolome changes in muscles would influence apoptotic and proteolytic process, leading to meat quality variation, has not been determined. Here, apoptotic and proteolytic attributes and metabolomics profiling of longissimus dorsi (LD) and psoas major (PM) muscles in pigs from two different production cycles (July–Jan vs. Apr–Sep) were evaluated. PM showed higher mitochondrial membrane permeability (MMP), concurrent with less extent of calpain-1 autolysis and troponin T degradation and higher abundance of HSP27 and αβ-crystallin compared to LD (P < 0.05). Apr–Sep muscles showed concurrence of extended apoptosis (indicated by higher MMP), calpain-1 autolysis and troponin T degradation, regardless of muscle effects (P < 0.05). Metabolomics profiling showed Apr–Sep muscles to increase in oxidative stress-related macronutrients, including 6-carbon sugars, some branched-chain AA, and free fatty acids. Antioxidant AA (His and Asp) and ascorbic acid were higher in July–Jan (P < 0.05). The results of the present study suggest that early postmortem apoptosis might be positively associated with pro-oxidant macronutrients and negatively associated with antioxidant metabolites, consequently affecting meat quality attributes in a muscle-specific manner.

Sepsis remains the most common cause of acute kidney injury (AKI) in critically ill patients, increasing the risk of in-hospital and long-term death. Rhizoma Coptidis (RC), a classical traditional Chinese herb, exhibits anti-inflammatory and antioxidant properties in various diseases including sepsis. This study aimed to investigate the protective effects of RC extracts (RCE) against sepsis-associated acute kidney injury (SA-AKI) and explore the underlying mechanisms with metabolomics-based network pharmacology. The results showed that RCE improved renal function and histological injury and decreased reactive oxygen species (ROS) production in SA-AKI. Using ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS), 25 differential metabolites were identified that had a close connection with the pathological processes of SA-AKI and the effects of RCE. Afterward, a compound-metabolite-target-disease network was constructed and 17 overlapping target proteins of the components of RCE, the differential metabolites, and the disease-related genes were discovered. Among these overlapping target proteins, RCE increased the nuclear translocation of nuclear factor-erythroid 2-related factor-2 (Nrf2), the protein expression of heme oxygenase-1 (HO-1), the mRNA expression of peroxisome proliferator activated receptor α (PPARα) and reduced nitric oxide synthase 2 (NOS2) activity. In addition, molecular docking revealed that both berberine and quercetin could bond with NOS2 and PPARα, respectively. Therefore, RCE demonstrated protective effects for SA-AKI through the regulation of metabolism and different signaling pathways.

Background Nephrolithiasis is a systemic metabolic disease with a high prevalence worldwide and is closely related to lipid-mediated oxidative stress and inflammation. Orthosiphon stamineus Benth. (OS) is a traditional medicinal herb mainly containing flavonoids, caffeic acid derivatives, and terpenoids, which has the effect of treating urinary stones. However, the active ingredients of OS for the treatment of kidney stones and their regulatory mechanisms remain unknown. As a powerful antioxidant, flavonoids from herbs can mitigate calcium oxalate stone formation by scavenging radical. Thus, this work focused on EtOAc extract of OS (EEOS, mainly flavonoids) and aimed to reveal the potential intrinsic mechanism of EEOS in the treatment of kidney stones disease. Methods Firstly, 75% ethanol extract of OS was further extracted with EtOAc to obtain EtOAc extract containing 88.82% flavonoids. Secondly, the extract was subjected to component analysis and used in animal experiments. Then, an untargeted lipidomics based on ultrahigh performance liquid chromatography coupled with TripleTOF 5600 mass spectrometer (UPLC-QTOF-MS) was performed to test the lipid changes of kidneys in the control group, model group and EEOS treatment groups. Finally, multivariate statistical analysis was used to identify differences between the lipid profiles of mice in the model group and the EEOS group. Results Fifty-one lipid metabolites were significantly different between the mice in the model group and the EEOS intervention group, including glycerophosphocholines, glycerophosphoethanolamines, glycerophosphoinositols, and glycerophosphoglycerols. And the composition of glycerophospholipids-esterified ω-3 polyunsaturated fatty acids and glycerophospholipid subclasses in the kidneys of the EEOS group significantly changed compared to model group. Conclusions The EEOS can inhibit the stones formation by improving oxidative stress and inflammation mediated by glycerophospholipid metabolism. This study reveals the potential mechanism of EEOS for kidney stones treatment at the lipid molecule level, providing a new direction for further study of the efficacy of OS.

As a reductive gas, hydrogen plays an antioxidant role by selectively scavenging oxygen free radicals. It has been reported that hydrogen has protective effects against nerve damage caused by ischemia–reperfusion in stroke, but the specific mechanism is still unclear. Therefore, this study aims to investigate the protective effects of hydrogen on stroke-induced ischemia–reperfusion injury and its detailed mechanism. Two weeks after the inhalation of high concentrations (66.7%) of hydrogen, middle cerebral artery occlusion (MCAO) was induced in mice using the thread occlusion technique to establish an animal model of the focal cerebral ischemia–reperfusion. Then, a metabolomics analysis of mouse cerebral cortex tissues was first performed by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) to study the metabolic changes and protective mechanisms of hydrogen on stroke ischemia–reperfusion injury. According to the metabolomic profiling of cortex tissues, 29 different endogenous metabolites were screened, including palmitoyl-l-carnitine, citric acid, glutathione, taurine, acetyl-l-carnitine, N-acetylaspartylglutamic acid (NAAG), l-aspartic acid, lysophosphatidylcholine (LysoPC) and lysophosphatidylethanolamine (LysoPE). Through pathway analysis, the metabolic pathways were concentrate on the glutathione pathway and the taurine pathway, mitochondrial energy metabolism and phospholipid metabolism that related to the oxidative stress process. This result reveals that hydrogen may protect against ischemic stroke by reducing oxidative stress during ischemia–reperfusion, thereby protecting nerve cells from reactive oxygen species(ROS).

目的 通过研究草酸钙结石小鼠尿液中代谢物的变化，探究草酸钙结晶导致肾损伤的内在机制。 方法 以乙醛酸盐诱导的小鼠草酸钙结晶模型为对象，采用基于超高效液相-四极杆飞行时间串联质谱（UPLC-Q-TOF/MS）的代谢组学方法测定尿液中内源性代谢物的变化，并采用SIMCA-P进行多元统计分析，Metabo Analyst软件进行代谢物通路分析。 结果 与正常组相比，模型组小鼠的肾组织出现明显的钙盐沉积且血清中的肌酐和尿素氮含量异常升高，肾脏出现损伤；从尿液中筛选出尿酸、牛磺酸、苯丙氨酸等21个差异代谢物。 结论 通过代谢物通路分析，差异代谢物主要涉及氨基酸代谢、能量代谢、牛磺酸代谢、嘌呤代谢和VB6代谢，为进行结石疾病机制研究以及早期标志物的筛选提供了重要参考。

Nephrolithiasis is a systemic metabolic disease with a worldwide incidence that is increasing yearly, as well as a high recurrence rate; however, this disease's pathogenesis has not been thoroughly elucidated to date. Several epidemiological studies have shown that the risk for developing kidney stones increases in people with dyslipidemia. To explore the mechanism of lipid-induced kidney stones, we established a mouse model for renal urolithiasis based on intraperitoneal injections of glyoxylate (120 mg/kg/d). Lipidomics based on ultra high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS/MS) was performed to determine the changes in lipid metabolism in serum and kidneys. We screened 179 and 196 different lipid metabolites in the kidneys and serum, respectively, including fatty acyls, glycerophospholipids, sphingolipids, glycerolipids and prenol lipids. We found that polyunsaturated fatty acids, such as arachidonic acid, eicosapentaenoic acid, and docosahexoenoic acid, and ceramides and lysophosphocholines mediated inflammatory responses and that the oxidative stress induced by oleylethanolamine and glycerophosphoethanolamine plasmalogens is closely related to the development of kidney stones. These results provide strong evidence for the relationship between lipid metabolism and the development of kidney stones and suggest a clear direction for future research.

Vascular depression (VD), a subtype of depression, is caused by vascular diseases or cerebrovascular risk factors. Recently, the proportion of VD patients has increased significantly, which severely affects their quality of life. However, the current pathogenesis of VD has not yet been fully understood, and the basic research is not adequate. In this study, on the basis of the combination of LC-MS-based proteomics and metabolomics, we aimed to establish a protein metabolism regulatory network in a murine VD model to elucidate a more comprehensive impact of VD on organisms. We detected 44 metabolites and 304 proteins with different levels in the hippocampus samples from VD mice using a combination of metabolomic and proteomics analyses with an isobaric tags for relative and absolute quantification (iTRAQ) method. We constructed a protein-to-metabolic regulatory network by correlating and integrating the differential metabolites and proteins using ingenuity pathway analysis. Then we quantitatively validated the levels of the bimolecules shown in the bioinformatics analysis using LC-MS/MS and Western blotting. Validation results suggested changes in the regulation of neuroplasticity, transport of neurotransmitters, neuronal cell proliferation and apoptosis, and disorders of amino acids, lipids and energy metabolism. These proteins and metabolites involved in these dis-regulated pathways will provide a more targeted and credible direction to study the mechanism of VD. Therefore, this paper presents an approach and strategy that was applied in integrative proteomics and metabolomics for research and screening potential targets and biomarkers of VD, which could be more precise and credible in a field lacking adequate basic research.

Osteoporosis, characterized by bone mass reduction and increased fractures, has become a global health problem that seriously affects the health of people, especially postmenopausal women; however, the current pathogenesis of postmenopausal osteoporosis (PMOP) has not been thoroughly elucidated to date. In this study, bilateral ovariectomy was performed to establish an OVX mouse model of osteoporosis. UPLC-Q-TOF-MS-based lipidomics in combination with metabolomics were used to analyze the femur tissue of osteoporosis mice. We found that 11 polar metabolites and 93 lipid metabolites were significantly changed and were involved in amino acid metabolism, nucleotide metabolism and lipid metabolism. Among the lipids, fatty acyls, glycerolipids, glycerophospholipids, sphingolipids and sterols showed robust changes. These results revealed that several metabolic disorders caused by changes in the hormone levels in OVX, especially disordered lipid metabolism, are closely related to the imbalance between bone resorption and formation and may underlie the development of PMOP. The data generated via lipidomics and metabolomics presented in this study shows good applicability and wide coverage in the construction of the metabolic profile of bone tissue. Therefore, this approach may provide the pathway focusing and data support at the metabolite level for the in-depth mechanism of PMOP.