Identification of candidate biomarkers of brain damage in a mouse model of closed head injury: a metabolomic pilot study

We aim to identify candidate brain biomarkers for, and to elucidate the pathophysiology of closed traumatic brain injury (TBI). Nuclear magnetic resonance (NMR) based metabolomic analysis was performed on the whole brain of mice undergoing TBI using a validated technique. There were 10 TBI mice compared to 8 sham operated controls. A total of 45 metabolites were evaluated. There was a statistically significant alteration in concentrations of 29 metabolites in TBI brains as compared to controls (FDR <0.05). Profound disturbances of several metabolic pathways (FDR <1E-07), including pathways associated with purine, alanine, aspartate and glutamine and glutathione metabolism were observed. Also, a significant elevation in glutamate (the main excitatory neurotransmitter) and depression of GABA (the main inhibitory neurotransmitter) was observed. Four metabolites, ADP, AMP, NAD+, and IMP were the most important indicators of TBI, relative to normal controls. All were elevated in the TBI mice. A combination of these 4 biomarkers produced a perfect predictor of TBI status, AUC (95 % CI) = 1.0 (1.0, 1.0). We also detected significant disturbances in mitochondrial function, energy metabolism, neurotransmitter metabolism and other important biochemical pathways in TBI mouse brains. Further studies to assess the utility of metabolomics to detect and classify the severity of and assess the prognosis of TBI is warranted.     

Metabolomics of biomarker discovery in ovarian cancer: a systematic review of the current literature

Introduction

Metabolomics is the emerging member of “omics” sciences advancing the understanding, diagnosis and treatment of many cancers, including ovarian cancer (OC).

Objectives

To systematically identify the metabolomic abnormalities in OC detection, and the dominant metabolic pathways associated with the observed alterations.

Methods

An electronic literature search was performed, up to and including January 15th 2016, for studies evaluating the metabolomic profile of patients with OC compared to controls. QUADOMICS tool was used to assess the quality of the twenty-three studies included in this systematic review.

Results

Biological samples utilized for metabolomic analysis include: serum/plasma (n = 13), urine (n = 4), cyst fluid (n = 3), tissue (n = 2) and ascitic fluid (n = 1). Metabolites related to cellular respiration, carbohydrate, lipid, protein and nucleotide metabolism were significantly altered in OC. Increased levels of tricarboxylic acid cycle intermediates and altered metabolites of the glycolytic pathway pointed to perturbations in cellular respiration. Alterations in lipid metabolism included enhanced fatty acid oxidation, abnormal levels of glycerolipids, sphingolipids and free fatty acids with common elevations of palmitate, oleate, and myristate. Increased levels of glutamine, glycine, cysteine and threonine were commonly reported while enhanced degradations of tryptophan, histidine and phenylalanine were found. N-acetylaspartate, a brain amino acid, was found elevated in primary and metastatic OC tissue and ovarian cyst fluid. Further, elevated levels of ketone bodies including 3-hydroxybutyrate were commonly reported. Increased levels of nucleotide metabolites and tocopherols were consistent through out the studies.

Conclusion

Metabolomics presents significant new opportunities for diagnostic biomarker development, elucidating previously unknown mechanisms of OC pathogenesis.

     

Serum metabolomic markers for traumatic brain injury: a mouse model

Introduction

Traumatic brain injury (TBI) is physical injury to brain tissue that temporarily or permanently impairs brain function.

Objectives

Evaluate the use of metabolomics for the development of biomarkers of TBI for the diagnosis and timing of injury onset.

Methods

A validated model of closed injury TBI was employed using 10 TBI mice and 8 sham operated controls. Quantitative LC–MS/MS metabolomic analysis was performed on the serum.

Results

Thirty-six (24.0 %) of 150 metabolites were altered with TBI. Principal component analysis (PCA) and Partial least squares discriminant analysis (PLS-DA) analyses revealed clear segregation between TBI versus control sera. The combination of methionine sulfoxide and the lipid PC aa C34:4 accurately diagnosed TBI, AUC (95 % CI) 0.85 (0.644–1.0). A combination of metabolite markers were highly accurate in distinguishing early (4 h post TBI) from late (24 h) TBI: AUC (95 % CI) 1.0 (1.0–1.0). Spermidine, which is known to have an antioxidant effect and which is known to be metabolically disrupted in TBI, was the most discriminating biomarker based on the variable importance ranking in projection (VIP) plot. Several important metabolic pathways were found to be disrupted including: pathways for arginine, proline, glutathione, cysteine, and sphingolipid metabolism.

Conclusion

Using serum metabolomic analysis we were able to identify novel putative serum biomarkers of TBI. They were accurate for detecting and determining the timing of TBI. In addition, pathway analysis provided important insights into the biochemical mechanisms of brain injury. Potential clinical implications for diagnosis, timing, and monitoring brain injury are discussed.

     

Maternal transfer of photoperiodic information in Siberian hamsters. II. The nature of the maternal signal, time of signal transfer, and the effect of the maternal signal on peripubertal reproductive development in the absence of photoperiodic input

Peripubertal reproductive development of Siberian hamsters is controlled by maternally derived photoperiodic information and the ambient photoperiod present after weaning. Previous experiments suggested that the maternally derived information is transferred during gestation, not during lactation. Development was examined in several photoperiods following manipulation of gestational and lactational photoperiods; development was influenced by the gestational, but not lactational, photoperiod. Second, effects of the gestational photoperiod were observed in young reared in constant light (LL) from Day 15. Depriving the young of ambient photoperiodic information after Day 15 allows a more direct assessment of the signal received from their dams. Finally, melatonin injections to long-day dams, at certain times of day, caused transmission of a short-day signal to young, as evidenced by their development in LL and light-dark cycles. Thus, a maternally derived signal that is dependent on melatonin influences reproductive development of the young during gestation; the maternally directed pattern of development can subsequently be modified by the youngs' own response to ambient photoperiods after weaning.     

Twenty-five loci form a continuous linkage map of markers for human chromosome 7

We have constructed a primary genetic linkage map from DNA markers that define 25 loci on chromosome 7. The markers form a continuous linkage group of 141 cM in males and 340 cM in females; female genetic distances were on average more than twofold higher than those in males throughout the chromosome. The average heterozygosity of the loci was 45%. A subset of the markers can be used for efficient application of this map to studies of human genetic disease.     

Molecular nature of chromosome 5q loss in colorectal tumors and desmoids from patients with familial adenomatous polyposis

Summary Familial adenomatous polyposis (FAP), which includes familial polyposis coli (FPC) and the Gardner syndrome (GS), is a genetically determined premalignant disease of the colon inherited by a locus (APC) mapping within 5q15–q22. To elucidate the role of 5q loss in FAP tumorigenesis, we analysed 51 colorectal tumors and seven desmoids from 19 cases of FPC and five GS patients, as well as 15 sporadic colon cancers. RFLP analysis revealed a high incidence of allelic deletion in hereditary colon cancers as well as in sporadic colon cancers with a peak at the APC locus. APC loss resulted primarily from interstitial deletion or mitotic recombination. Combined tumor and pedigree analysis in a GS family revealed loss of normal 5q alleles in three tumors, including a desmoid tumor, which suggests the involvement of hemizygosity or homozygosity of the defective APC gene in colon carcinogenesis and, possibly, in extracolonic neoplasms associated with FAP.     

STRUCTURE AND DEVELOPMENT OF THE SIEVE-ELEMENT PROTOPLAST IN THE HYPOCOTYL OF PINUS RESINOSA

Hypocotyl tissue of Pinus resinosa Ait. was fixed in glutaraldehyde-paraformaldehyde and postfixed in osmium tetroxide for electron microscopy. Although young sieve cells contain all the components characteristic of young, nucleate cells, they can be identified early in their development. Increase in wall thickness occurs early and rapidly. Concurrently, the plastids, which already contain starch granules, form both crystalline and fibrillar inclusions. As the sieve cell approaches maturity, an extensive network of smooth, tubular endoplasmic reticulum (ER), which becomes mostly parietal in distribution, is formed. At maturity, massive aggregates of this ER occur on both sides of sieve areas. These ER aggregates are interconnected with one another longitudinally by the parietal ER. In addition, the mature, plasmalemma-lined sieve cell contains a degenerate nucleus, mitochondria, and intact plastids. Dictyosomes, ribosomes, and vacuolar membranes are lacking. P-protein is not present at any stage of development.