Characterization of trotter horses urine metabolome by means of proton nuclear magnetic resonance spectroscopy

Nuclear Magnetic Resonance (NMR) Metabolomics: Current Applications in Equine Health Assessment

Metabolomics can allow for the comprehensive identification of metabolites within biological systems, at given time points, in physiological and pathological conditions. In the last few years, metabolomic analysis has gained popularity both in human and in veterinary medicine, showing great potential for novel applications in clinical activity. The aim of applying metabolomics in clinical practice is understanding the mechanisms underlying pathological conditions and the influence of certain stimuli (i.e., drugs, nutrition, exercise) on body systems, in the attempt of identifying biomarkers that can help in the diagnosis of diseases. Proton Nuclear Magnetic Resonance spectroscopy (1H-NMR) is well tailored to be used as an analytical platform for metabolites' detection at the base of metabolomics studies, due to minimal sample preparation and high reproducibility. In this mini-review article, the scientific production of NMR metabolomic applications to equine medicine is examined. The research works are very different in methodology and difficult to compare. Studies are mainly focused on exercise, reproduction, and nutrition, other than respiratory and musculoskeletal diseases. The available information on this topic is still scant, but a greater collection of data could allow researchers to define new reliable markers to be used in clinical practice for diagnostic and therapeutical purposes.

Metabolomic Analysis of Multiple Biological Specimens (Feces, Serum, and Urine) by 1H-NMR Spectroscopy from Dairy Cows with Clinical Mastitis

Due to huge economic losses to the dairy industry worldwide, mastitis can be considered as one of the most common diseases in dairy cows. This work aimed to study this disease by comparing multiple biological specimens (feces, serum, and urine) from individuals with or without clinical mastitis. This was performed by a single analytical platform, namely ¹H-NMR, through a multi-matrix strategy. Thanks to the high reproducibility of ¹H-NMR, we could characterize 120 molecules across dairy cow feces, serum, and urine. Among them, 23 molecules were in common across the three biofluids. By integrating the results of multi-matrix metabolomics, several pathways pertaining to energy metabolism and amino acid metabolism appeared to be affected by clinical mastitis. The present work wished to deepen the understanding of dairy cow mastitis in its clinical form. Simultaneous analysis of metabolome changes across several key biofluids could facilitate knowledge discovery and the reliable identification of potential biomarkers, which could be, in turn, used to shed light on the early diagnosis of dairy cow mastitis in its subclinical form.

Evaluation of the metabolomic profile through 1H-NMR spectroscopy in ewes affected by postpartum hyperketonemia

Ketosis is one of the most important health problems in dairy sheep. The aim of this study was to evaluate the metabolic alterations in hyperketonemic (HYK) ewes. Forty-six adult Sardinian ewes were enrolled between 7 ± 3 days post-partum. Blood samples were collected from the jugular vein using Venosafe tubes containing clot activator from jugular vein after clinical examination. The concentration of β-hydroxybutyrate (BHB) was determined in serum and used to divide ewes into assign ewes into: Non-HYK (serum BHB < 0.80 mmol/L) and HYK (serum BHB ≥ 0.80 mmol/L) groups. Animal data and biochemical parameters of groups were examined with one-way ANOVA, and metabolite differences were tested using a t-test. A robust principal component analysis model and a heatmap were used to highlight common trends among metabolites. Over-representation analysis was performed to investigate metabolic pathways potentially altered in connection with BHB alterations. The metabolomic analysis identified 54 metabolites with 14 different between groups. These metabolites indicate altered ruminal microbial populations and fermentations; an interruption of the tricarboxylic acid cycle; initial lack of glucogenic substrates; mobilization of body reserves; the potential alteration of electron transport chain; influence on urea synthesis; alteration of nervous system, inflammatory response, and immune cell function.

Dominant Components of the Giant Panda Seminal Plasma Metabolome, Characterized by 1H-NMR Spectroscopy

Simple Summary

As China’s flagship animal, the giant panda (Ailuropoda melanoleuca) attracts much attention due to its small population and low natural reproductive rate. Therefore, artificial insemination has become the leading practical approach in the captive breeding programs of giant pandas worldwide. Seminal plasma acts as a medium between spermatozoa and the external stimuli, and its characteristics have been directly linked to fertility in both artificial insemination and natural fertilization. The current work, for the first time, attempts to characterize, by proton magnetic resonance spectroscopy (¹H-NMR), the metabolome of healthy giant panda seminal plasma. A total of 35 molecules were quantified, with distinct age-related trends highlighted by a multivariate analysis, and the concentrations of 2,3-butanediol were significantly different between individuals younger than 8 years and older than 13 years. In addition, isopropanol’s concentration was significantly linked to estrus stages. Besides, the variations in the metabolome’s profile with storage time were also evaluated. This study may serve as a reference for research wishing to shed light on the biological mechanisms affecting giant panda sperm’s overall quality and may ultimately lead to novel approaches to giant panda artificial insemination.

Abstract

As an assisted breeding technique, artificial insemination has become the main effective practical approach in the captive breeding programs of giant panda worldwide. The composition of seminal plasma plays an important role in the success of breeding. The present work is the first attempt to characterize, by proton magnetic resonance spectroscopy (¹H-NMR), the metabolome of healthy giant panda seminal plasma. A total of 35 molecules were quantified, with the concentration of 2,3-butanediol being significantly different between individuals younger than 8 years and older than 13 years, and other distinct age-related trends were highlighted by a multivariate analysis. Isopropanol’s concentration was significantly linked to estrus stages. Besides, the variations in the metabolome’s profile during storage were also evaluated. This study may serve as a reference for further research wishing to shed light on the biological mechanisms affecting giant panda sperm’s overall quality and may ultimately lead to novel approaches to giant panda artificial insemination.

Differences in the serum metabolome profile of dairy cows according to the BHB concentration revealed by proton nuclear magnetic resonance spectroscopy (1H-NMR)

The mobilization of body reserves during the transition from pregnancy to lactation might predispose dairy cows to develop metabolic disorders such as subclinical ketosis or hyperketonemia. These conditions are not easily identifiable and are frequently related to other diseases that cause economic loss. The aim of this study was to evaluate the serum metabolome differences according to the β-hydroxybutyrate (BHB) concentration. Forty-nine Holstein Friesian dairy cows were enrolled between 15 and 30 days in milk. According to their serum BHB concentration, the animals were divided into three groups: Group 0 (G0; 12 healthy animals; BHB ≤ 0.50 mmol/L); Group 1 (G1; 19 healthy animals; 0.51 ≤ BHB < 1.0 mmol/L); and Group 2 (G2; 18 hyperketonemic animals; BHB ≥ 1.0 mmol/L). Animal data and biochemical parameters were examined with one-way ANOVA, and metabolite significant differences were examined by t-tests. Fifty-seven metabolites were identified in the serum samples. Thirteen metabolites showed significant effects and seemed to be related to the mobilization of body reserves, lipids, amino acid and carbohydrate metabolism, and ruminal fermentation.

An Untargeted Metabolomics Investigation of Milk from Dairy Cows with Clinical Mastitis by 1H-NMR

Mastitis is one of the diseases with the highest incidence in dairy cows, causing huge economic losses to the dairy industry all over the world. The aim of the study was to characterize mastitic milk metabolome through untargeted nuclear magnetic resonance spectroscopy (¹H-NMR). Taking advantage of the high reproducibility of ¹H-NMR, we had the opportunity to provide quantitative information for all the metabolites identified. Fifty-four molecules were characterized, sorted mainly into the chemical groups, namely amino acids, peptides and analogues, carbohydrates and derivates, organic acids and derivates, nucleosides, nucleotides and analogues. Combined with serum metabolomic investigations, several pathways were addressed to explain the mechanisms of milk metabolome variation affected by clinical mastitis, such as tricarboxylic acid cycle (TCA cycle) and phenylalanine, tyrosine and tryptophan biosynthesis. These results provide a further understanding of milk metabolome altered by clinical mastitis, which can be used as a reference for the further milk metabolome investigations.

Metabolic profiling of rats poisoned with paraquat and treated with Xuebijing using a UPLC-QTOF-MS/MS metabolomics approach

Xuebijing (XBJ) is a compound Chinese medicine that contains Paeoniae Radix Rubra, ChuanXiong Rhizoma, Salvia Miltiorrhiza Radix et Rhizoma, Carthami Flos, and Angelicae Sinensis Radix. It is widely used in China to treat sepsis. Previous studies have demonstrated that XBJ can decrease mortality in patients with moderate paraquat poisoning. However, the mechanism by which it exerts this effect is not completely clear. In this study, an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS)-based metabolomics approach was used to perform a metabolic profiling analysis. Principal component analysis (PCA), random forest (RF), and partial least squares discriminant analysis (PLS-DA) were used to identify metabolites to clarify the mechanism of XBJ's activity. XBJ clearly alleviated lung injury in a Sprague Dawley (SD) rat model of paraquat (PQ) poisoning. Seven metabolites related to four pathways, including those involved in sphingolipid and phospholipid metabolism, amino acid metabolism, unsaturated fatty acid metabolism, and pantothenic acid and CoA biosynthesis, were present at different levels in PQ-poisoned rats treated with XBJ compared with untreated rats. XBJ can ameliorate the effects of PQ poisoning in SD rats. Using a metabolomics approach enabled us to gain new insight into the mechanism underlying this effect.

Exercise Induced Changes in Salivary and Serum Metabolome in Trained Standardbred, Assessed by 1H-NMR

In the present study, data related to the metabolomics of saliva and serum in trained standardbred horses are provided for the first time. Metabolomic analysis allows to analyze all the metabolites within selected biofluids, providing a better understanding of biochemistry modifications related to exercise. On the basis of the current advances observed in metabolomic research on human athletes, we aimed to investigate the metabolites’ profile of serum and saliva samples collected from healthy standardbred horses and the relationship with physical exercise. Twelve trained standardbred horses were sampled for blood and saliva before (T₀) and immediately after (T₁) standardized exercise. Metabolomic analysis of both samples was performed by ¹H-NMR spectroscopy. Forty-six metabolites in serum and 62 metabolites in saliva were detected, including alcohols, amino acids, organic acids, carbohydrates and purine derivatives. Twenty-six and 14 metabolites resulted to be significantly changed between T₀ and T₁ in serum and saliva, respectively. The findings of 2-hydroxyisobutyrate and 3-hydroxybutyrate in serum and GABA in equine saliva, as well as their modifications following exercise, provide new insights about the physiology of exercise in athletic horses. Glycerol might represent a novel biomarker for fitness evaluation in sport horses.

Respiratory metabolites in bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) can differentiate horses affected by severe equine asthma from healthy horses

BACKGROUND

The use of an untargeted metabolomic approach to investigate biofluids of respiratory origin is of increasing interest in human and veterinary lung research. Considering the high incidence of equine asthma (> 14%) within horse population and the importance of this animal model for human disease, we aimed to investigate the metabolomic profile of bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) in healthy and asthmatic horses.

RESULTS

On the basis of clinical, endoscopic and BALF cytology findings, 6 horses with severe asthma (Group A) and 6 healthy horses (Group C) were included in the study. 1H-NMR analysis was used to identified metabolites in BALF and EBC samples. Metabolomic analysis allowed to identify and quantify 12 metabolites in BALF and seven metabolites in EBC. Among respiratory metabolites, myo-inositol, formate, glycerol and isopropanol in BALF, and methanol and ethanol in EBC, differed between groups (p < 0.05).

CONCLUSIONS

The application of metabolomic studies to investigate equine asthma using minimally invasive diagnostic methods, such as EBC metabolomics, provided promising results. According to our research, the study of selective profiles of BALF and EBC metabolites might be useful for identifying molecules like myo-inositol and methanol as possible biomarkers for airways diseases in horses.

Urinary proteome and metabolome in dogs (Canis lupus familiaris): The effect of chronic kidney disease

Chronic kidney disease (CKD) is a progressive and irreversible disease. Although urine is an ideal biological sample for proteomics and metabolomics studies, sensitive and specific biomarkers are currently lacking in dogs. This study characterised dog urine proteome and metabolome aiming to identify and possibly quantify putative biomarkers of CKD in dogs. Twenty-two healthy dogs and 28 dogs with spontaneous CKD were selected and urine samples were collected. Urinary proteome was separated by SDS-PAGE and analysed by mass spectrometry, while urinary metabolome was analysed in protein-depleted samples by 1D ¹H NMR spectra. The most abundant proteins in urine samples from healthy dogs were uromodulin, albumin and, in entire male dogs, arginine esterase. In urine samples from CKD dogs, the concentrations of uromodulin and albumin were significantly lower and higher, respectively, than in healthy dogs. In addition, these samples were characterised by a more complex protein pattern indicating mixed glomerular (protein bands ≥65 kDa) and tubular (protein bands <65 kDa) proteinuria. Urine spectra acquired by NMR allowed the identification of 86 metabolites in healthy dogs, belonging to 49 different pathways mainly involved in amino acid metabolism, purine and aminoacyl-tRNA biosynthesis or tricarboxylic acid cycle. Seventeen metabolites showed significantly different concentrations when comparing healthy and CKD dogs. In particular, carnosine, trigonelline, and cis-aconitate, might be suggested as putative biomarkers of CKD in dogs. SIGNIFICANCE: Urine is an ideal biological sample, however few proteomics and metabolomics studies investigated this fluid in dogs and in the context of CKD (chronic kidney disease). In this research, applying a multi-omics approach, new insights were gained regarding the molecular changes triggered by this disease in canine urinary proteome and metabolome. In particular, the involvement of the tubular component was highlighted, suggesting uromodulin, trigonelline and carnosine as possible biomarkers of CKD in dogs.

First Insights into the Urinary Metabolome of Captive Giraffes by Proton Nuclear Magnetic Resonance Spectroscopy

The urine from 35 giraffes was studied by untargeted ¹H-NMR, with the purpose of obtaining, for the first time, a fingerprint of its metabolome. The metabolome, as downstream of the transcriptome and proteome, has been considered as the most representative approach to monitor the relationships between animal physiological features and environment. Thirty-nine molecules were unambiguously quantified, able to give information about diet, proteins digestion, energy generation, and gut-microbial co-metabolism. The samples collected allowed study of the effects of age and sex on the giraffe urinary metabolome. In addition, preliminary information about how sampling procedure and pregnancy could affect a giraffe’s urinary metabolome was obtained. Such work could trigger the setting up of methods to non-invasively study the health status of giraffes, which is utterly needed, considering that anesthetic-related complications make their immobilization a very risky practice.

An Untargeted Metabolomics Investigation of Jiulong Yak (Bos grunniens) Meat by 1H-NMR

Yak represents the main meat source for Tibetan people. This work aimed to investigate the metabolome of raw meat from Jiulong yaks, focusing on specimens farmed and harvested locally through traditional procedures. Untargeted nuclear magnetic resonance spectroscopy (¹H-NMR) was selected as the analytical platform. Samples from longissimus thoracis, trapezius, triceps brachii and biceps femoris muscles, with different prevalences of red and white fibers, were selected. Among the fifty-three metabolites quantified in each of them, carnitine, carnosine, creatine and taurine are known for their bioactive properties. Twelve molecules were found to be differently concentrated in relation to muscle type. Longissimus thoracis, compared to biceps femoris, had higher concentrations of carnosine and formate and lower concentrations of mannose, inosine, threonine, IMP, alanine, valine, isoleucine, tyrosine, phenylalanine and leucine. A metabolic pathway analysis suggested that the main pathways differing among the muscles were connected to the turnover of amino acids. These results contribute to a deeper understanding of yak raw meat metabolism and muscle type differences, which can be used as an initial reference for the meat industry to set up muscle-specific investigations. The possibility of simultaneously quantifying several bioactive compounds suggests that these investigations could revolve around meat’s nutritional value.

First Steps toward the Giant Panda Metabolome Database: Untargeted Metabolomics of Feces, Urine, Serum, and Saliva by 1H NMR

Differences in the concentration of metabolites in the biofluids of animals closely reflect their physiological diversities. In order to set the basis for a metabolomic atlas for giant panda (Ailuropoda melanoleuca), we characterized the metabolome of healthy giant panda feces (23), urine (16), serum (6), and saliva (4) samples by means of ¹H NMR. A total of 107 metabolites and a core metabolome of 12 metabolites was quantified across the four biological matrices. Through univariate analysis followed by robust principal component analysis, we were able to describe how the molecular profile observed in giant panda urine and feces was affected by gender and age. Among the molecules modified by age in feces, fucose plays a peculiar role because it is related to the digestion of bamboo's hemicellulose, which is considered as the main source of energy for giant panda. A metagenomic investigation directed toward this molecule showed that its concentration was indeed positively related to the two-component system pathway and negatively related to the amino sugar and nucleotide sugar metabolism pathway. Such work is meant to provide a robust framework for further -omics research studies on giant panda to accelerate our understanding of the interaction of giant panda with its natural environment.

UPLC-ESI-IT-TOF-MS metabolomic study of the therapeutic effect of Xuefu Zhuyu decoction on rats with traumatic brain injury

It has been widely reported that Xuefu Zhuyu decoction (XFZYD), a traditional Chinese medicine, is effective in the treatment of traumatic brain injury (TBI). However, the mechanism of the therapeutic process is still not fully understood. Metabolomic technique can be used to explore the mechanisms underlying the treatment of TBI with XFZYD. The purpose of this work was to investigate the metabolic characteristics of blood samples from rats with and without XFZYD treatment and the dynamic changes in metabolite profiles on days 1, 3, 7, 14 and 21 after injury (within the severe phase of TBI) based on untargeted UPLC-ESI-IT-TOF-MS analysis. Pattern recognition, clustering analysis and metabolic pathway analysis were used to analyse the metabolomic data of three groups (a sham-operated group, a TBI model, and an XFZYD-treated TBI model). The results showed that XFZYD reversed the abnormalities in the levels of small-molecule metabolites (such as L-acetylcarnitine, L-tryptophan, indoleacrylic acid, γ-aminobutyric acid, hypotaurine, LysoPC(18:1)(11Z), creatine, L-phenylalanine and L-leucine) in TBI rats through six metabolic pathways (including phenylalanine, tyrosine and tryptophan biosynthesis; phenylalanine metabolism; valine, leucine and isoleucine biosynthesis; taurine and hypotaurine metabolism; tryptophan metabolism; and alanine, aspartate and glutamate metabolism) involved in the therapy process. XFZYD regulated the metabolic disorders of endogenous markers by the possible mechanisms of neuroprotection, energy metabolism, inflammatory response and oxidative stress. This study revealed the holistic and dynamic metabolic changes caused by XFZYD in rats with TBI and provided important research methods and approaches for exploring the multiple metabolites and metabolic pathways involved in the therapeutic effect of XFZYD on TBI.

Infected chronic ischemic wound topically treated with a multi-strain probiotic formulation: a novel tailored treatment strategy

Background

A wide debate is ongoing regarding the role of cutaneous dysbiosis in the pathogenesis and evolution of difficult-to-treat chronic wounds. Nowadays, probiotic treatment considered as an useful tool to counteract dysbiosis but the evidence in regard to their therapeutic use in the setting of difficult-to-treat cutaneous ulcers is still poor.

Aim: clinical report

An 83-year-old woman suffering a critical limb ischemia and an infected difficult-to-treat ulcerated cutaneous lesion of the right leg, was complementary treated with local application of a mixture of probiotic bacteria.

Methods

Microbiological and metabolomic analysis were conducted on wound swabs obtained before and after bacteriotherapy.

Results

During the treatment course, a progressive healing of the lesion was observed with microbiological resolution of the polymicrobial infection of the wound. Metabolomic analysis showed a significant difference in the local concentration of propionate, 2-hydroxyisovalerate, 2-oxoisocaproate, 2,3-butanediol, putrescine, thymine, and trimethylamine before and after bacteriotherapy.

Conclusion

The microbiological and metabolomic results seem to confirm the usefulness of complementary probiotic treatment in difficult-to-treat infected wounds. Further investigations are needed to confirm these preliminary findings.

Characterization of Yak Common Biofluids Metabolome by Means of Proton Nuclear Magnetic Resonance Spectroscopy

The aim of this study was to evaluate the metabolic profiles of yak (Bos grunniens) serum, feces, and urine by using proton nuclear magnetic resonance (¹H-NMR), to serve as a reference guide for the healthy yak milieu. A total of 108 metabolites, giving information about diet, protein digestion, and energy generation or gut-microbial co-metabolism, were assigned across the three biological matrices. A core metabolome of 15 metabolites was ubiquitous across all biofluids. Lactate, acetate, and creatinine could be regarded as the most abundant metabolites in the metabolome of serum, feces, and urine, respectively. Metabolic pathway analysis showed that the molecules identified could be able to give thorough information about four main metabolic pathways, namely valine, leucine, and isoleucine biosynthesis; phenylalanine, tyrosine, and tryptophan biosynthesis; glutamine and glutamate metabolism; and taurine and hypotaurine metabolism.