Metabolomic analysis of thermally injured and/or septic rats

Nanoplastic contamination: Impact on zebrafish liver metabolism and implications for aquatic environmental health

Nanoplastics (NPs) are increasingly pervasive in the environment, raising concerns about their potential health implications, particularly within aquatic ecosystems. This study investigated the impact of polystyrene nanoparticles (PSN) on zebrafish liver metabolism using liquid chromatography hybrid quadrupole time of flight mass spectrometry (LC-QTOF-MS) based non-targeted metabolomics. Zebrafish were exposed to 50 nm PSN for 28 days at low (L-PSN) and high (H-PSN) concentrations (0.1 and 10 mg/L, respectively) via water. The results revealed significant alterations in key metabolic pathways in low and high exposure groups. The liver metabolites showed different metabolic responses with L-PSN and H-PSN. A total of 2078 metabolite features were identified from the raw data obtained in both positive and negative ion modes, with 190 metabolites deemed statistically significant in both L-PSN and H-PSN groups. Disruptions in lipid metabolism, inflammation, oxidative stress, DNA damage, and amino acid synthesis were identified. Notably, L-PSN exposure induced changes in DNA building blocks, membrane-associated biomarkers, and immune-related metabolites, while H-PSN exposure was associated with oxidative stress, altered antioxidant metabolites, and liver injury. For the first time, L-PSN was found depolymerized in the liver by cytochrome P450 enzymes. Utilizing an analytical approach to the adverse outcome pathway (AOP), impaired lipid metabolism and oxidative stress have been identified as potentially conserved key events (KEs) associated with PSN exposure. These KEs further induced liver inflammation, steatosis, and fibrosis at the tissue and organ level. Ultimately, this could significantly impact biological health. The study highlights the PSN-induced effects on zebrafish liver metabolism, emphasizing the need for a better understanding of the risks associated with NPs contamination in aquatic ecosystems.

Fish Skin Grafts Affect Adenosine and Methionine Metabolism during Burn Wound Healing

Burn wound healing is a complex process orchestrated through successive biochemical events that span from weeks to months depending on the depth of the wound. Here, we report an untargeted metabolomics discovery approach to capture metabolic changes during the healing of deep partial-thickness (DPT) and full-thickness (FT) burn wounds in a porcine burn wound model. The metabolic changes during healing could be described with six and seven distinct metabolic trajectories for DPT and FT wounds, respectively. Arginine and histidine metabolism were the most affected metabolic pathways during healing, irrespective of burn depth. Metabolic proxies for oxidative stress were different in the wound types, reaching maximum levels at day 14 in DPT burns but at day 7 in FT burns. We examined how acellular fish skin graft (AFSG) influences the wound metabolome compared to other standard-or-care burn wound treatments. We identified changes in metabolites within the methionine salvage pathway, specifically in DPT burn wounds that is novel to the understanding of the wound healing process. Furthermore, we found that AFSGs boost glutamate and adenosine in wounds that is of relevance given the importance of purinergic signaling in regulating oxidative stress and wound healing. Collectively, these results serve to define biomarkers of burn wound healing. These results conclusively contribute to the understanding of the multifactorial mechanism of the action of AFSG that has traditionally been attributed to its structural properties and omega-3 fatty acid content.

Alterations in the gut microbiome and metabolome profiles of septic mice treated with Shen FuHuang formula

Sepsis has a high mortality rate, and treating sepsis remains a significant challenge worldwide. In former studies, our group found that traditional Chinese medicine, Shen FuHuang formula (SFH), is a promising medicine in treating coronavirus disease 2019 (COVID-19) patients with the septic syndrome. However, the underlying mechanisms remain elusive. In the present study, we first investigated the therapeutic effects of SFH on septic mice. To investigate the mechanisms of SFH-treated sepsis, we identified the gut microbiome profile and exploited untargeted metabolomics analyses. The results demonstrated that SFH significantly enhanced the mice’s 7-day survival rate and hindered the release of inflammatory mediators, i.e., TNF-α, IL-6, and IL-1β. 16S rDNA sequencing further deciphered that SFH decreased the proportion of Campylobacterota and Proteobacteria at the phylum level. LEfSe analysis revealed that the treatment of SFH enriched Blautia while decreased Escherichia_Shigella. Furthermore, serum untargeted metabolomics analysis indicated that SFH could regulate the glucagon signaling pathway, PPAR signaling pathway, galactose metabolism, and pyrimidine metabolism. Finally, we found the relative abundance of Bacteroides, Lachnospiraceae_NK4A136_group, Escherichia_Shigella, Blautia, Ruminococcus, and Prevotella were closely related to the enrichment of the metabolic signaling pathways, including L-tryptophan, uracil, glucuronic acid, protocatechuic acid, and gamma-Glutamylcysteine. In conclusion, our study demonstrated that SFH alleviated sepsis by suppressing the inflammatory response and hence reduced mortality. The mechanism of SFH for treating sepsis may be ascribed to the enrichment of beneficial gut flora and modulation in glucagon signaling pathway, PPAR signaling pathway, galactose metabolism, and pyrimidine metabolism. To sum up, these findings provide a new scientific perspective for the clinical application of SFH in treating sepsis.

The metabolic effects of multi-trace elements on parenteral nutrition for critically ill pediatric patients: a randomized controlled trial and metabolomic research

BACKGROUND

We investigated the efficacy and metabolic dose-effect of multi-trace element injection I [MTEI-(I)] for severe pediatric patients via a parallel, randomized control study.

METHODS

The inclusion criteria were as follows: (I) patients who required parenteral nutrition (PN) due to various diseases, and were expected to receive PN for >5 days; (II) patients aged <18 years; (III) patients with no serious cardiac, hepatic, renal, or pulmonary dysfunction; and (IV) patients with an established central venous pathway. Enrolled patients were randomly assigned into two groups using sequentially numbered, sealed, opaque envelopes: Group A (low-dose group) received MTEI-(I) at 1 mL/kg/d, and Group B (high-dose group) received MTEI-(I) at 2 mL/kg/d, up to a maximum dose of 15 mL/d. The concentrations of manganese (Mn), copper (Cu), zinc (Zn), and selenium (Se) were detected. The following indexes were measured after 5 days of treatment (T5): β-oxidation of very-long-chain fatty acids, arginine and proline metabolism, pentose phosphate metabolism, ketone body metabolism, citric acid cycle, purine metabolism, caffeine metabolism, and pyruvate metabolism. The participants, care givers, and data analysis staff were blinded to the group assignment.

RESULTS

Overall, at T5, Mn and Cu levels were decreased, while Zn and Se levels were increased. The increase of Zn levels (A: 0.170±0.479 vs. B: 0.193±0.900) and decrease of Cu levels (A: -0.240±0.382 vs. B: -0.373±0.465) of patients in Group B (n=22) were significantly higher than those in Group A (n=18). At T5, the β-oxidation of very-long-chain fatty acids, arginine and proline metabolism, pentose phosphate metabolism, ketone body metabolism, citric acid cycle, purine metabolism, caffeine metabolism, and pyruvate metabolism were variably decreased (P<0.05) in Group B compared to Group A.

CONCLUSIONS

Our results suggested that the high-dose administration of MTEI-(I) is safe for severe pediatric patients, and may alleviate inflammation and antioxidation, relieve hyperactivity caused by stress, and improve tissues-based hypoxia and renal function.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100052198.

Damage-Associated Molecular Patterns and the Systemic Immune Consequences of Severe Thermal Injury

Thermal injury is often associated with a proinflammatory state resulting in serious complications. After a burn, the innate immune system is activated with subsequent immune cell infiltration and cytokine production. Although the innate immune response is typically beneficial, an excessive activation leads to cytokine storms, multiple organ failure, and even death. This overwhelming immune response is regulated by damage-associated molecular patterns (DAMPs). DAMPs are endogenous molecules that are actively secreted by immune cells or passively released by dead or dying cells that can bind to pathogen recognition receptors in immune and nonimmune cells. Recent studies involving animal models along with human studies have drawn great attention to the possible pathological role of DAMPs as an immune consequence of thermal injury. In this review, we outline DAMPs and their function in thermal injury, shedding light on the mechanism of sterile inflammation during tissue injury and identifying new immune targets for treating thermal injury.

Cutaneous Thermal Injury Modulates Blood and Skin Metabolomes Differently in a Murine Model

As the field of metabolomics develops further, investigations of how the metabolome is affected following thermal injury may be helpful to inform diagnostics and guide treatments. In this study, changes to the metabolome were tested and validated in a murine burn injury model. After a 30% total body surface scald injury or sham procedure sera and skin biopsies were collected at 1, 2, 6, or 24 hr.

Burn-specific changes in the metabolome were detected compared to sham animals. The sera metabolome exhibited a more rapid response to burn injury than that of the skin and it peaked more proximal to injury (6 vs 24 hr). Progression of metabolic response in the skin was less synchronous and showed a higher overlap of the significantly modified metabolites (SMMs) among tested time-points. Top affected pathways identified by SMMs of skin included inositol phosphate metabolism, ascorbate and alderate metabolism, caffeine metabolism, and the pentose phosphate pathway. Future research is warranted in human and larger animal models to further elucidate the role of metabolomic perturbations and the pathophysiology following burn injury.

Advanced Oxidation Protein Product (AOPP) Levels in Second- and Third-Degree Thermal Burns

Burn is a systemic injury affecting the entire organism according to its etiology and severity. The aim of this study was to investigate plasma AOPP levels before and after treatment of second- and third-degree thermal burn patients and determine the changes in this parameter, and also, to find out the relationship between AOPP level and hospitalization period and total body surface area (TBSA). The study material consisted of pediatric patients with the complaint of second- and third-degree thermal burns aged between 1 and 18 years, with a burn area exceeding 10%. Blood samples were taken twice before and after treatment. AOPP level in blood plasma was measured in ELISA. It was observed that in the second-degree thermal burn group, AOPP level was 25.85 ± 2.82 ng/ml before the treatment decreased to 22.16 ± 3.62 ng/ml after treatment, whereas in the third-degree thermal burn group before the treatment AOPP was 25.96 ± 3.49 ng/ml, and after the treatment dropped to 21.70 ± 3.79 ng/ml, decreases were significantly important (P < .05). There was no statistically significant difference between the two groups in terms of AOPP levels (P > .05). Correlation analyses in the second- and third-degree thermal burn group did not show any correlation between AOPP levels and burn area and length of hospitalization period. As a result, AOPP level has been studied, for the first time, in burn cases. In both groups, the level of AOPP increased due to oxidative stress before treatment and decreased after treatment.

Multiorgan Metabolomics and Lipidomics Provide New Insights Into Fat Infiltration in the Liver, Muscle Wasting, and Liver-Muscle Crosstalk Following Burn Injury

Burn injury mediated hypermetabolic syndrome leads to increased mortality among severe burn victims, due to liver failure and muscle wasting. Metabolic changes may persist up to 2 years following the injury. Thus, understanding the underlying mechanisms of the pathology is crucially important to develop appropriate therapeutic approaches. We present detailed metabolomic and lipidomic analyses of the liver and muscle tissues in a rat model with a 30% body surface area burn injury located at the dorsal skin. Three hundred and thirty-eight of 1587 detected metabolites and lipids in the liver and 119 of 1504 in the muscle tissue exhibited statistically significant alterations. We observed excessive accumulation of triacylglycerols, decreased levels of S-adenosylmethionine, increased levels of glutamine and xenobiotics in the liver tissue. Additionally, the levels of gluconeogenesis, glycolysis, and tricarboxylic acid cycle metabolites are generally decreased in the liver. On the other hand, burn injury muscle tissue exhibits increased levels of acyl-carnitines, alpha-hydroxyisovalerate, ophthalmate, alpha-hydroxybutyrate, and decreased levels of reduced glutathione. The results of this preliminary study provide compelling observations that liver and muscle tissues undergo distinctly different changes during hypermetabolism, possibly reflecting liver-muscle crosstalk. The liver and muscle tissues might be exacerbating each other's metabolic pathologies, via excessive utilization of certain metabolites produced by each other.

New markers for sepsis caused by Pseudomonas aeruginosa during burn infection

INTRODUCTION

Sepsis is a leading cause of mortality in burn patients. One of the major causes of sepsis in burn patients is Pseudomonas aeruginosa. We hypothesized that during dissemination from infected burn wounds and subsequent sepsis, P. aeruginosa affects the metabolome of the blood resulting in changes to specific metabolites that would serve as biomarkers for early diagnosis of sepsis caused by P. aeruginosa.

OBJECTIVES

To identify specific biomarkers in the blood after sepsis caused by P. aeruginosa infection of burns.

METHODS

Gas chromatography with time-of-flight mass spectrometry was used to compare the serum metabolome of mice that were thermally injured and infected with P. aeruginosa (B-I) to that of mice that were neither injured nor infected, mice that were injured but not infected, and mice that were infected but not injured.

RESULTS

Serum levels of 19 metabolites were significantly increased in the B-I group compared to controls while levels of eight metabolites were significantly decreased. Thymidine, thymine, uridine, and uracil (related to pyrimidine metabolism), malate and succinate (a possible sign of imbalance in the tricarboxylic acid cycle), 5-oxoproline (related to glutamine and glutathione metabolism), and trans-4-hydroxyproline (a major component of the protein collagen) were increased. Products of amino acid metabolism were significantly decreased in the B-I group, including methionine, tyrosine, indole-3-acetate, and indole-3-propionate.

CONCLUSION

In all, 26 metabolites were identified, including a unique combination of five metabolites (trans-4-hydroxyproline, 5-oxoproline, glycerol-3-galactoside, indole-3-acetate, and indole-3-propionate) that could serve as a set of biomarkers for early diagnosis of sepsis caused by P. aeruginosa in burn patients.

1H-NMR Metabolomics Identifies Significant Changes in Metabolism over Time in a Porcine Model of Severe Burn and Smoke Inhalation

Burn injury initiates a hypermetabolic response leading to muscle catabolism and organ dysfunction but has not been well-characterized by high-throughput metabolomics. We examined changes in metabolism over the first 72 h post-burn using proton nuclear magnetic resonance (¹H-NMR) spectroscopy and serum from a porcine model of severe burn injury. We sought to quantify the changes in metabolism that occur over time in response to severe burn and smoke inhalation in this preliminary study. Fifteen pigs received 40% total body surface area (TBSA) burns with additional pine bark smoke inhalation. Arterial blood was drawn at baseline (pre-burn) and every 24 h until 72 h post-injury or death. The aqueous portion of each serum sample was analyzed using ¹H-NMR spectroscopy and metabolite concentrations were used for principal component analysis (PCA). Thirty-eight metabolites were quantified in 39 samples. Of these, 31 showed significant concentration changes over time (p < 0.05). PCA revealed clustering of samples by time point on a 2D scores plot. The first 48 h post-burn were characterized by high concentrations of histamine, alanine, phenylalanine, and tyrosine. Later timepoints were characterized by rising concentrations of 2-hydroxybutyrate, 3-hydroxybutyrate, acetoacetate, and isovalerate. No significant differences in metabolism related to mortality were observed. Our work highlights the accumulation of organic acids resulting from fatty acid catabolism and oxidative stress. Further studies will be required to relate accumulation of the four organic carboxylates identified in this analysis to outcomes from burn injury.

Microdialysis Workflow for Metabotyping Superficial Pathologies: Application to Burn Injury

Burn injury can be a devastating traumatic injury, with long-term personal and social implications for the patient. The many complex local and disseminating pathological processes underlying burn injury’s clinical challenges are orchestrated from the site of injury and develop over time, yet few studies of the molecular basis of these mechanisms specifically explore the local signaling environment. Those that do are typically destructive in nature and preclude the collection of longitudinal temporal data. Burn injury therefore exemplifies a superficial temporally dynamic pathology for which experimental sampling typically prioritizes either specificity to the local burn site or continuous collection from circulation. Here, we present an exploratory approach to the targeted elucidation of complex, local, acutely temporally dynamic interstitia through its application to burn injury. Subcutaneous microdialysis is coupled with ultraperformance liquid chromatography–mass spectrometry (UPLC–MS) analysis, permitting the application of high-throughput metabolomic profiling to samples collected both continuously and specifically from the burn site. We demonstrate this workflow’s high yield of burn-altered metabolites including the complete structural elucidation of niacinamide and uric acid, two compounds potentially involved in the pathology of burn injury. Further understanding the metabolic changes induced by burn injury will help to guide therapeutic intervention in the future. This approach is equally applicable to the analysis of other tissues and pathological conditions, so it may further improve our understanding of the metabolic changes underlying a wide variety of pathological processes.

Metabolomics approach in lung tissue of septic rats and the interventional effects of Xuebijing injection using UHPLC-Q-Orbitrap-HRMS

Sepsis is the dysregulated host response to an infection which leads to life-threatening organ dysfunction. Metabolomic profiling in bio-fluid or tissue is vital for elucidating the pathogenesis of sepsis and evaluating therapeutic effects of medication. In this study, an untargeted metabolomics approach was applied to study the metabolic changes in lung tissue of septic rats induced by cecal ligation and puncture (CLP) and investigate the treatment effects of Xubijing injection (XBJ). Metabolomics analyses were performed on ultra-high performance liquid chromatography-Q Exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry (UHPLC-Q-Orbitrap-HRMS) together with multivariate statistical analysis. A total of 26 differential metabolites between CLP and sham-operated group were identified. The altered metabolic pathways included energy metabolism, amino metabolism, lipid metabolism, fatty acid metabolism and hormone metabolism. Among the 26-varied metabolites, 15 were significantly regulated after XBJ treatment. The metabolic pathway network of sepsis was drawn to interpret the pathological feature of lung damage caused by sepsis and the underlying regulating mechanism of XBJ on the molecular levels. Our findings display that LC-MS-based metabolomics is a useful tool for uncovering the underlying molecular mechanism of sepsis, and XBJ may exert therapeutic effect by regulating multiple metabolic pathways.

Metabolomics and Precision Medicine in Trauma: The State of the Field

Trauma is a major problem in the United States. Mortality from trauma is the number one cause of death under the age of 45 in the United States and is the third leading cause of death for all age groups. There are approximately 200,000 deaths per year due to trauma in the United States at a cost of over $671 billion in combined healthcare costs and lost productivity. Unsurprisingly, trauma accounts for approximately 30% of all life-years lost in the United States. Due to immense development of trauma systems, a large majority of trauma patients survive the injury, but then go on to die from complications arising from the injury. These complications are marked by early and significant metabolic changes accompanied by inflammatory responses that lead to progressive organ failure and, ultimately, death. Early resuscitative and surgical interventions followed by close monitoring to identify and rescue treatment failures are key to successful outcomes. Currently, the adequacy of resuscitation is measured using vital signs, noninvasive methods such as bedside echocardiography or stroke volume variation, and other laboratory endpoints of resuscitation, such as lactate and base deficit. However, these methods may be too crude to understand cellular and subcellular changes that may be occurring in trauma patients. Better diagnostic and therapeutic markers are needed to assess the adequacy of interventions and monitor responses at a cellular and subcellular level and inform clinical decision-making before complications are clinically apparent. The developing field of metabolomics holds great promise in the identification and application of biochemical markers toward the clinical decision-making process.

Chemical profiling and quantitation of bioactive compounds in Platycladi Cacumen by UPLC-Q-TOF-MS/MS and UPLC-DAD

Platycladi Cacumen (PC) is a traditional Chinese medicine used for the treatment of hemorrhages, cough, asthma and hair loss. To get a better understanding of the chemical constituents in PC, ultra-high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) and diagnostic ion filtering strategy were firstly employed for chemical profiling of PC. A total of 43 compounds including organic acids and derivatives, flavonoids as well as phenylpropanolds were unambiguously or reasonably identified. Coumarin and lignan were reported for the first time in PC. Chemical variation of 39 batches of PC from different geographical origins and 10 batches of processed product of PC was subsequently investigated by quantitation of nine major flavonoids. The results determined by UPLC coupled with diode array detection (UPLC-DAD) and hierarchical cluster analysis (HCA) indicated that the contents of flavonoids in PC samples differ greatly. This work provides an efficient approach to comprehensively evaluate the quality of PC.

Metabolomic findings in sepsis as a damage of host-microbial metabolism integration

Metabolomics globally evaluates the totality of the endogenous metabolites in patient's body, at the same time reflecting gene function, enzyme activity and degree of organ dysfunction in sepsis. The authors performed the analysis of the main chemical classes of low molecular weight compounds (amino acids, polyols, fatty acids, hydroxy acids, amines, nucleotides and their derivatives) that quantitatively distinguish patients with sepsis from healthy ones. The following keywords were used to find papers published in the Scopus and Web of Science databases from 2008 to 2015: (marker OR biomarker) AND (sepsis OR critical ill OR pneumonia OR hypoxia). Key words for the search were the following: metabolomics, metabolic profiling, sepsis, metabolism, biomarkers, critically ill patients, multiple organ failure. Several metabolomic findings in sepsis are still waiting for an explanation. When assessing metabolomic analysis results in patients with sepsis we should take into account the intervention of microbial metabolism. Among the low molecular weight compounds detected in septic patient blood, a special attention should be paid to the molecules which could be attributed to "common metabolites" of man and bacteria. The genomic region overlap and the production of enzymes which are similar in function and final products could be a possible reason for this phenomenon. For example, microbial biodegradation products of aromatic compounds are increased many times in blood of patients with sepsis. On the one hand, it shows a high metabolic activity of the bacteria. On the other hand, these molecules are intermediates in the metabolism of aromatic amino acids such as tyrosine and phenylalanine in human body. It is important that there are many clinical studies, which confirmed the diagnostic and prognostic significance of series of aromatic metabolites, including those with intrinsic biological activity. We can't exclude the presence of signaling pathways, cell receptors, transmembrane transporters and others which are common for a human and bacteria and their direct participation in mechanisms of organ dysfunction and hypotension in sepsis. Thus, today, we should not limit ourselves studying eukaryotic cells while searching for new molecular mechanisms of sepsis-associated organ failure and septic shock. We should take into account and simulate in the experiments the changes of a human internal environment, which occur during the radical microbiome "restructuring" in critically ill patients. This approach opens up new prospects for an objective monitoring of diseases, carrying out an assessment of the integral metabolic profile in a given time on common metabolites (particularly aromatic), and in future will provide new targets for therapeutic effects.

Amino acid and acylcarnitine profiles in perinatal asphyxia: a case-control study

OBJECTIVE

To estimate cord blood amino acid and acylcarnitine levels in term newborns exposed to perinatal asphyxia.

MATERIALS AND METHODS

We studied 45 asphyxiated term newborns (cases) and 20 gestational age-matched healthy newborns (control). 16 cases developed HIE according to clinical scoring and amplitude-integrated electroencephalography. Asphyxiated cases were accordingly subdivided into: HIE group (n = 16) and Asphyxia group (n = 29). Amino acid and acylcarnitine levels were measured in cord blood dried spot samples from all newborns using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Data were analyzed using one-way ANOVA with post hoc test and MetaboAnalyst-2.

RESULTS

Distinct metabolite alterations were detected in cases versus control, in HIE versus Asphyxia, and in Survivors within HIE group (n = 6) versus nonsurvivors (n = 10). Principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) showed increased levels of methionine and certain acylcarnitines, but reduced levels of ornithine, histidine, and arginine. Metabolite set enrichment analysis (MSEA); compared to KEGG library metabolite sets, identified some disorders with similar metabolomic derangements.

CONCLUSIONS

We report UPLC-MS detectable alterations of amino acids and acylcarnitines in asphyxiated newborns at birth, that can serve as early diagnostic bedside biomarkers for HIE and predictors for its short-term outcome, and in the near future, as therapeutic targets.

Mass spectrometry for the discovery of biomarkers of sepsis

Sepsis is a serious medical condition that occurs in 30% of patients in intensive care units (ICUs). Early detection of sepsis is key to prevent its progression to severe sepsis and septic shock, which can cause organ failure and death. Diagnostic criteria for sepsis are nonspecific and hinder a timely diagnosis in patients. Therefore, there is currently a large effort to detect biomarkers that can aid physicians in the diagnosis and prognosis of sepsis. Mass spectrometry is often the method of choice to detect metabolomic and proteomic changes that occur during sepsis progression. These "omics" strategies allow for untargeted profiling of thousands of metabolites and proteins from human biological samples obtained from septic patients. Differential expression of or modifications to these metabolites and proteins can provide a more reliable source of diagnostic biomarkers for sepsis. Here, we focus on the current knowledge of biomarkers of sepsis and discuss the various mass spectrometric technologies used in their detection. We consider studies of the metabolome and proteome and summarize information regarding potential biomarkers in both general and neonatal sepsis.

Application of LC-MS-based metabolomics method in differentiating septic survivors from non-survivors

Septic shock is the most severe form of sepsis, which is still one of the leading causes of death in the intensive care unit (ICU). Even though early prognosis and diagnosis are known to be indispensable for reaching an optimistic outcome, pathogenic complexities and the lack of specific treatment make it difficult to predict the outcome individually. In the present study, serum samples from surviving and non-surviving septic shock patients were drawn before clinical intervention at admission. Metabolic profiles of all the samples were analyzed by liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. One thousand four hundred nineteen peaks in positive mode and 1878 peaks in negative mode were retained with their relative standard deviation (RSD) below 30 %, in which 187 metabolites were initially identified by retention time and database in the light of the exact molecular mass. Differences between samples from the survivors and the non-survivors were investigated using multivariate and univariate analysis. Finally, 43 significantly varied metabolites were found in the comparison between survivors and non-survivors. Concretely, metabolites in the tricarboxylic acid (TCA) cycle, amino acids, and several energy metabolism-related metabolites were up-regulated in the non-survivors, whereas those in the urea cycle and fatty acids were generally down-regulated. Metabolites such as lysine, alanine, and methionine did not present significant changes in the comparison. Six metabolites were further defined as primary discriminators differentiating the survivors from the non-survivors at the early stage of septic shock. Our findings reveal that LC-MS-based metabolomics is a useful tool for studying septic shock. Graphical abstract ᅟ.

Metabolites Associated With Malnutrition in the Intensive Care Unit Are Also Associated With 28-Day Mortality

BACKGROUND

We hypothesized that metabolic profiles would differ in critically ill patients with malnutrition relative to those without.

MATERIALS AND METHODS

We performed a prospective cohort study on 85 adult patients with systemic inflammatory response syndrome or sepsis admitted to a 20-bed medical intensive care unit (ICU) in Boston. We generated metabolomic profiles using gas and liquid chromatography and mass spectroscopy. We followed this by logistic regression and partial least squares discriminant analysis to identify individual metabolites that were significant. We then interrogated the entire metabolomics profile using metabolite set enrichment analysis and network model construction of chemical-protein target interactions to identify groups of metabolites and pathways that were differentiates in patients with and without malnutrition.

RESULTS

Of the cohort, 38% were malnourished at admission to the ICU. Metabolomic profiles differed in critically ill patients with malnutrition relative to those without. Ten metabolites were significantly associated with malnutrition ( P < .05). A parsimonious model of 5 metabolites effectively differentiated patients with malnutrition (AUC = 0.76), including pyroglutamine and hypoxanthine. Using pathway enrichment analysis, we identified a critical role of glutathione and purine metabolism in predicting nutrition. Nutrition status was associated with 28-day mortality, even after adjustment for known phenotypic variables associated with ICU mortality. Importantly, 7 metabolites associated with nutrition status were also associated with 28-day mortality.

CONCLUSION

Malnutrition is associated with differential metabolic profiles early in critical illness. Common to all of our metabolome analyses, glutathione and purine metabolism, which play principal roles in cellular redox regulation and accelerated tissue adenosine triphosphate degradation, respectively, were significantly altered with malnutrition.

The biochemistry of blister fluid from pediatric burn injuries: proteomics and metabolomics aspects

Burn injury is a prevalent and traumatic event for pediatric patients. At present, the diagnosis of burn injury severity is subjective and lacks a clinically relevant quantitative measure. This is due in part to a lack of knowledge surrounding the biochemistry of burn injuries and that of blister fluid. A more complete understanding of the blister fluid biochemistry may open new avenues for diagnostic and prognostic development. Burn insult induces a highly complex network of signaling processes and numerous changes within various biochemical systems, which can ultimately be examined using proteome and metabolome measurements. This review reports on the current understanding of burn wound biochemistry and outlines a technical approach for 'omics' profiling of blister fluid from burn wounds of differing severity.

Monitoring neonatal fungal infection with metabolomics

The objective of our study was to evaluate the capability of the metabolomics approach to identify the variations of urine metabolites over time related to the neonatal fungal septic condition. The study population included a clinical case of a preterm neonate with invasive fungal infection and 13 healthy preterm controls. This study showed a unique urine metabolic profile of the patient affected by fungal sepsis compared to urine of controls and it was also possible to evaluate the efficacy of therapy in improving patient health.

Discrimination of sepsis stage metabolic profiles with an LC/MS-MS-based metabolomics approach

Background

To identify metabolic biomarkers that can be used to differentiate sepsis from systemic inflammatory response syndrome (SIRS), assess severity and predict outcomes.

Methods

65 patients were involved in this study, including 35 patients with sepsis, 15 patients with SIRS and 15 normal patients. Small metabolites that were present in patient serum samples were measured by liquid chromatography mass spectrometry techniques and analysed using multivariate statistical methods.

Results

The metabolic profiling of normal patients and patients with SIRS or sepsis was markedly different. A significant decrease in the levels of lactitol dehydrate and S-phenyl-d-cysteine and an increase in the levels of S-(3-methylbutanoyl)-dihydrolipoamide-E and N-nonanoyl glycine were observed in patients with sepsis in comparison to patients with SIRS (p<0.05). Patients with severe sepsis and septic shock displayed lower levels of glyceryl-phosphoryl-ethanolamine, Ne, Ne dimethyllysine, phenylacetamide and d-cysteine (p<0.05) in their sera. The profiles of patients with sepsis 48 h before death illustrated an obvious state of metabolic disorder, such that S-(3-methylbutanoyl)-dihydrolipoamide-E, phosphatidylglycerol (22:2 (13Z, 16Z)/0:0), glycerophosphocholine and S-succinyl glutathione were significantly decreased (p<0.05). The receiver operating characteristic curve of the differential expression of these metabolites was also performed.

Conclusions

The body produces significant evidence of metabolic disorder during SIRS or sepsis. Seven metabolites may potentially be used to diagnose sepsis.

Trial registration number

ClinicalTrial.gov identifier NCT01649440.

Therapeutic interventions in sepsis: current and anticipated pharmacological agents

Sepsis is a clinical syndrome characterized by a multisystem response to a pathogenic assault due to underlying infection that involves a combination of interconnected biochemical, cellular and organ-organ interactive networks. After the withdrawal of recombinant human-activated protein C (rAPC), researchers and physicians have continued to search for new therapeutic approaches and targets against sepsis, effective in both hypo- and hyperinflammatory states. Currently, statins are being evaluated as a viable option in clinical trials. Many agents that have shown favourable results in experimental sepsis are not clinically effective or have not been clinically evaluated. Apart from developing new therapeutic molecules, there is great scope for for developing a variety of drug delivery strategies, such as nanoparticulate carriers and phospholipid-based systems. These nanoparticulate carriers neutralize intracorporeal LPS as well as deliver therapeutic agents to targeted tissues and subcellular locations. Here, we review and critically discuss the present status and new experimental and clinical approaches for therapeutic intervention in sepsis.

Phytochemical analysis of Pfaffia glomerata inflorescences by LC-ESI-MS/MS

Pfaffia glomerata contains high levels of β-ecdysone, which has shown a range of beneficial pharmacological effects. The present study demonstrated that inflorescences of P. glomerata contain other important bioactive compounds in addition to β-ecdysone. The identification of compounds from inflorescences using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) was performed for the first time. The eight compounds identified were β-ecdysone, flavonoid glycosides such as quercetin-3-O-glucoside, kaempferol-3-O-glucoside and kaempferol-3-O-(6-p-coumaroyl)-glucoside, oleanane-type triterpenoid saponins such as ginsenoside Ro and chikusetsusaponin IV, in addition to oleanonic acid and gluconic acid. This study provided information on the phytochemicals contained in P. glomerata inflorescences revealing the potential application of this plant part as raw material for the phytotherapeutic and cosmetic industries.

Leukocyte infiltration and activation of the NLRP3 inflammasome in white adipose tissue following thermal injury

OBJECTIVES

Severe thermal injury is associated with extreme and prolonged inflammatory and hypermetabolic responses, resulting in significant catabolism that delays recovery or even leads to multiple organ failure and death. Burned patients exhibit many symptoms of stress-induced diabetes, including hyperglycemia, hyperinsulinemia, and hyperlipidemia. Recently, the nucleotide-binding domain, leucine-rich family (NLR), pyrin-containing 3 (NLRP3) inflammasome has received much attention as the sensor of endogenous "danger signals" and mediator of "sterile inflammation" in type II diabetes. Therefore, we investigated whether the NLRP3 inflammasome is activated in the adipose tissue of burned patients, as we hypothesize that, similar to the scenario observed in chronic diabetes, the cytokines produced by the inflammasome mediate insulin resistance and metabolic dysfunction.

DESIGN

Prospective cohort study.

SETTING

Ross Tilley Burn Centre & Sunnybrook Research Institute.

PATIENTS

We enrolled 76 patients with burn sizes ranging from 1% to 70% total body surface area. All severely burned patients exhibited burn-induced insulin resistance and hyperglycemia.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We examined the adipose tissue of control and burned patients and found, via flow cytometry and gene expression studies, increased infiltration of leukocytes-especially macrophages-and evidence of inflammasome priming and activation. Furthermore, we observed increased levels of interleukin-1β in the plasma of burned patients when compared to controls.

CONCLUSIONS

In summary, our study is the first to show activation of the inflammasome in burned humans, and our results provide impetus for further investigation of the role of the inflammasome in burn-induced hypermetabolism and, potentially, developing novel therapies targeting this protein complex for the treatment of stress-induced diabetes.

New diagnostic possibilities in systemic neonatal infections: metabolomics

Systemic neonatal infection is a serious complication in preterm and term infants and is defined as a complex clinical syndrome caused by bacteria, fungi and virus. Sepsis remains among the leading causes of death in both developed and underdeveloped countries above all in the neonatal period. Earlier diagnosis may offer the ability to initiate treatment to prevent adverse outcomes. There have been many studies on various diagnostic haematological markers like acute phase reactants, C-reactive protein, procalcitonin, interleukins and presepsin. However, there is still no single test that satisfies the criteria as being the ideal marker for the early diagnosis of neonatal sepsis. In this regard, metabolomic analysis seems to be a promising method for determining metabolic variations correlated with systemic neonatal infections.

Is 1H NMR metabolomics becoming the promising early biomarker for neonatal sepsis and for monitoring the antibiotic toxicity?

Metabolomics, the latest of omics disciplines, has been successfully used in various fields of basic research such as pharmacology and toxicology. Recently, this new science has gained an important role in the translational research of diagnostics. In this regard, the challenge for neonatologists and medical laboratories is to diagnose neonatal sepsis, a disease with high mortality and morbidity due to the difficulty in diagnosing it. Metabolomics, through its ability to identify perturbations caused by this condition, aims at recognizing metabolites that characterize neonatal sepsis with high specificity and sensitivity. The purpose of this review is to highlight the ability of metabolomics to find early biomarkers for this condition, as well as to predict the toxic effects caused by antibiotics.

Effect of acute thermal injury in status of serum vitamins, inflammatory markers, and oxidative stress markers: preliminary data

The objective of this study was to evaluate the vitamin status, inflammatory markers, and oxidative stress markers in adult patients up to 3 days after thermal injury. This prospective study was conducted with 11 patients 24 to 72 hours after thermal injury (Burn Group), total surface area ranging from 10 to 41%, 34.3 ± 9.3 years, 82% of males, body mass index of 22.3 ± 2.9 kg/m(2). We included 11 healthy adults (Control Group), 36.5 ± 7.6 years, 73% of males, and body mass index of 23.8 ± 2.5 kg/m(2). Laboratory data were measured (plasma total protein, albumin, transferrin, lymphocyte counts, zinc, and iron), as well as serum vitamins (folic acid, vitamin B12, and vitamins A, C, and E), inflammatory stress markers (C-reactive protein, ferritin, and acid α1-glycoprotein) and oxidative stress markers such as glutathione peroxidase (GPx) and thiobarbituric acid reactive substances. The inflammatory stress was characterized by lower levels of total protein (median difference 1.2 g/dL, 95% CI: 0.4-2.1) and albumin (median difference 0.9 g/dL, 95% CI: 0.5-1.5), and higher levels of C-reactive protein (median difference -8.12 mg/dL, 95% CI: -11.62 to 4.61) and α-1 glycoprotein acid (median difference -28.56 mg/dL, 95% CI: -51.57 to -5.07) in burn patients. Decreased serum levels of vitamin A (median difference 1.10 μmol/L, 95% confidence interval [CI]: 0.42-1.66) and vitamin C (median difference 0.82 mg/dL, 95% CI: 0.50-1.04) were also detected. There was no statistical evidence of difference in the serum levels of glutathione peroxidase and thiobarbituric acid reactive substances between burn patients and controls, respectively. Even though there is an inflammatory stress, the obtained data showed that oxidative stress markers are normal 24 to 72 hours after burn injury. The decrease in negative acute phase protein may account for the diminished serum levels of vitamin A, which seems to be related to inflammatory stress. The marked decrease in the serum levels of vitamin C can be justified by augmented cutaneous loss and consumption in the regeneration of vitamin E.

Metabolomics in pneumonia and sepsis: an analysis of the GenIMS cohort study

PURPOSE

To determine the global metabolomic profile as measured in circulating plasma from surviving and non-surviving patients with community-acquired pneumonia (CAP) and sepsis.

METHODS

Random, outcome-stratified case-control sample from a prospective study of 1,895 patients hospitalized with CAP and sepsis. Cases (n = 15) were adults who died before 90 days, and controls (n = 15) were adults who survived, matched on demographics, infection type, and procalcitonin. We determined the global metabolomic profile in the first emergency department blood sample using non-targeted mass-spectrometry. We derived metabolite-based prognostic models for 90-day mortality. We determined if metabolites stimulated cytokine production by differentiated Thp1 monocytes in vitro, and validated metabolite profiles in mouse liver and kidney homogenates at 8 h in cecal ligation and puncture (CLP) sepsis.

RESULTS

We identified 423 small molecules, of which the relative levels of 70 (17 %) were different between survivors and non-survivors (p ≤ 0.05). Broad differences were present in pathways of oxidative stress, bile acid metabolism, and stress response. Metabolite-based prognostic models for 90-day survival performed modestly (AUC = 0.67, 95 % CI 0.48, 0.81). Five nucleic acid metabolites were greater in non-survivors (p ≤ 0.05). Of these, pseudouridine increased monocyte expression of TNFα and IL1β versus control (p < 0.05). Pseudouridine was also increased in liver and kidney homogenates from CLP mice versus sham (p < 0.05 for both).

CONCLUSIONS

Although replication is required, we show the global metabolomic profile in plasma broadly differs between survivors and non-survivors of CAP and sepsis. Metabolite-based prognostic models had modest performance, though metabolites of oxidative stress may act as putative damage-associated molecular patterns.

Tissue metabolite profiling identifies differentiating and prognostic biomarkers for prostate carcinoma

Metabolomic research offers a deeper insight into biochemical changes in cancer metabolism and is a promising tool for identifying novel biomarkers. We aimed to evaluate the diagnostic and prognostic potential of metabolites in prostate cancer (PCa) tissue after radical prostatectomy. In matched malignant and nonmalignant prostatectomy samples from 95 PCa patients, aminoadipic acid, cerebronic acid, gluconic acid, glycerophosphoethanolamine, 2-hydroxybehenic acid, isopentenyl pyrophosphate, maltotriose, 7-methylguanine and tricosanoic acid were determined within a global metabolite profiling study using gas chromatography/liquid chromatography-mass spectrometry. The data were related to clinicopathological variables like prostate volume, tumor stage, Gleason score, preoperative prostate-specific antigen and disease recurrence in the follow-up. All nine metabolites showed higher concentrations in malignant than in nonmalignant samples except for gluconic acid and maltotriose, which had lower levels in tumors. Receiver -operating characteristics analysis demonstrated a significant discrimination for all metabolites between malignant and nonmalignant tissue with a maximal area under the curve of 0.86 for tricosanoic acid, whereas no correlation was observed between the metabolite levels and the Gleason score or tumor stage except for gluconic acid. Univariate Cox regression and Kaplan-Meier analyses showed that levels of aminoadipic acid, gluconic acid and maltotriose were associated with the biochemical tumor recurrence (prostate-specific antigen > 0.2 ng/mL). In multivariate Cox regression analyses, aminoadipic acid together with tumor stage and Gleason score remained in a model as independent marker for prediction of biochemical recurrence. This study proved that metabolites in PCa tissue can be used, in combination with traditional clinicopathological factors, as promising diagnostic and prognostic tools.

Metabolomics in neonatology: fact or fiction?

The newest 'omics' science is metabolomics, the latest offspring of genomics, considered the most innovative of the 'omics' sciences. Metabolomics, also called the 'new clinical biochemistry', is an approach based on the systematic study of the complete set of metabolites in a biological sample. The metabolome is considered the most predictive phenotype and is capable of considering epigenetic differences. It is so close to the phenotype that it can be considered the phenotype itself. In the last three years about 5000 papers have been listed in PubMed on this topic, but few data are available in the newborn. The aim of this review, after a description of background and technical procedures, is to analyse the clinical applications of metabolomics in neonatology, covering the following points: gestational age, postnatal age, type of delivery, zygosity, perinatal asphyxia, intrauterine growth restriction, prenatal inflammation and brain injury, respiratory, cardiovascular renal, metabolic diseases; sepsis, necrotizing enterocolitis and antibiotic treatment; nutritional studies on maternal milk and formula, pharma-metabolomics, long-term diseases. Pros and cons of metabolomics are also discussed. All this comes about with the non-invasive collection of a few drops of urine (exceptionally important for the neonate, especially those of low birth weight). Only time and large-scale studies to validate initial results will place metabolomics within neonatology. In any case, it is important for perinatologists to learn and understand this new technology to offer their patients the utmost in diagnostic and therapeutic opportunities.

Burn injury induces gelsolin expression and cleavage in the brain of mice

Gelsolin is an actin filament-severing and capping protein, affecting cellular motility, adhesiveness and apoptosis. Whether it is expressed in the brain of burned mice has not yet been characterized. Mice were subjected to a 15% total body surface area scald injury. Neuropathology was examined by hematoxylin and eosin staining. Cerebral gelsolin mRNA, distribution and cleavage were demonstrated by quantitative polymerase chain reaction (QPCR), immunohistochemistry and Western blot, respectively. Cysteinyl aspartate-specific protease (caspase)-3-positive cells and activity were also measured. Burn injury could induce pathological alterations in the brain including leukocyte infiltration, necrosis, microabscess and gliosis. Compared with sham-injured mice, gelsolin mRNA was up-regulated at 8h post-burn (pb) in a transient manner in the cortex and striatum of burned mice, while it remained at higher levels in the hippocampus up to 72 hpb. Of interest, gelsolin was further cleaved into 42 and 48 kDa (kilo Dalton) fragments as illustrated in the hippocampus at 24 hpb, and was widely expressed in the brain by activated monocyte/macrophages, astrocytes and damaged neurons. In the meantime, caspase-3-positive cells were noted in the striatum of burned mice and its activity peaked at 24 hpb. To clarify inflammation-induced gelsolin expression and cleavage in the brain, rat pheochromocytoma cells were exposed to lipopolysaccharide to show increased gelsolin expression and caspase-3-dependent cleavage. The results suggest that burn-induced cerebral gelsolin expression would be involved in the activation of both the monocytes and astroglial cells, thereby playing a crucial role in the subsequent inflammation-induced neural apoptosis following burn injury.