Studies on the age dependent changes in serum adenosine deaminase activity and its changes in hepatitis

Investigating metabolic dysregulation in serum of triple transgenic Alzheimer's disease male mice: implications for pathogenesis and potential biomarkers

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease that lacks convenient and accessible peripheral blood diagnostic markers and effective drugs. Metabolic dysfunction is one of AD risk factors, which leaded to alterations of various metabolites in the body. Pathological changes of the brain can be reflected in blood metabolites that are expected to explain the disease mechanisms or be candidate biomarkers. The aim of this study was to investigate the changes of targeted metabolites within peripheral blood of AD mouse model, with the purpose of exploring the disease mechanism and potential biomarkers. Targeted metabolomics was used to quantify 256 metabolites in serum of triple transgenic AD (3 × Tg-AD) male mice. Compared with controls, 49 differential metabolites represented dysregulation in purine, pyrimidine, tryptophan, cysteine and methionine and glycerophospholipid metabolism. Among them, adenosine, serotonin, N-acetyl-5-hydroxytryptamine, and acetylcholine play a key role in regulating neural transmitter network. The alteration of S-adenosine-L-homocysteine, S-adenosine-L-methionine, and trimethylamine-N-oxide in AD mice serum can served as indicator of AD risk. The results revealed the changes of metabolites in serum, suggesting that metabolic dysregulation in periphery in AD mice may be related to the disturbances in neuroinhibition, the serotonergic system, sleep function, the cholinergic system, and the gut microbiota. This study provides novel insights into the dysregulation of several key metabolites and metabolic pathways in AD, presenting potential avenues for future research and the development of peripheral biomarkers.

Early-life social experience affects offspring DNA methylation and later life stress phenotype

Studies in rodents and captive primates suggest that the early-life social environment affects future phenotype, potentially through alterations to DNA methylation. Little is known of these associations in wild animals. In a wild population of spotted hyenas, we test the hypothesis that maternal care during the first year of life and social connectedness during two periods of early development leads to differences in DNA methylation and fecal glucocorticoid metabolites (fGCMs) later in life. Here we report that although maternal care and social connectedness during the den-dependent life stage are not associated with fGCMs, greater social connectedness during the subadult den-independent life stage is associated with lower adult fGCMs. Additionally, more maternal care and social connectedness after den independence correspond with higher global (%CCGG) DNA methylation. We also note differential DNA methylation near 5 genes involved in inflammation, immune response, and aging that may link maternal care with stress phenotype.

Adenosine and Metabotropic Glutamate Receptors Are Present in Blood Serum and Exosomes from SAMP8 Mice: Modulation by Aging and Resveratrol

Adenosine (ARs) and metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors (GPCRs) that are modulated in the brain of SAMP8 mice, an animal model of Alzheimer's disease (AD). In the present work, it is shown the presence of ARs and mGluRs in blood serum and derived exosomes from SAMP8 mice as well as its possible modulation by aging and resveratrol (RSV) consumption. In blood serum, adenosine A₁ and A_2A receptors remained unaltered from 5 to 7 months of age. However, an age-related decrease in adenosine level was observed, while 5'-Nucleotidase activity was not modulated. Regarding the glutamatergic system, it was observed a decrease in mGluR₅ density and glutamate levels in older mice. In addition, dietary RSV supplementation caused an age-dependent modulation in both adenosinergic and glutamatergic systems. These GPCRs were also found in blood serum-derived exosomes, which might suggest that these receptors could be released into circulation via exosomes. Interestingly, changes elicited by age and RSV supplementation on mGluR₅ density, and adenosine and glutamate levels were similar to that detected in whole-brain. Therefore, we might suggest that the quantification of these receptors, and their corresponding endogenous ligands, in blood serum could have predictive value for early diagnosis in combination with other distinctive hallmarks of AD.

Serum metabolic profiling identified a distinct metabolic signature in patients with idiopathic pulmonary fibrosis - a potential biomarker role for LysoPC

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a lethal lung disease of unknown etiology. Patients present loss of lung function, dyspnea and dry cough. Diagnosis requires compatible radiologic imaging and, in undetermined cases, invasive procedures such as bronchoscopy and surgical lung biopsy. The pathophysiological mechanisms of IPF are not completely understood. Lung injury with abnormal alveolar epithelial repair is thought to be a major cause for activation of profibrotic pathways in IPF. Metabolic signatures might indicate pathological pathways involved in disease development and progression. Reliable serum biomarker would help to improve both diagnostic approach and monitoring of drug effects.

METHOD

The global metabolic profiles measured by ultra high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) of ten stable IPF patients were compared to the ones of ten healthy participants. The results were validated in an additional study of eleven IPF patients and ten healthy controls.

RESULTS

We discovered 10 discriminative metabolic features using multivariate and univariate statistical analysis. Among them, we identified one metabolite at a retention time of 9.59 min that was two times more abundant in the serum of IPF patients compared to healthy participants. Based on its ion pattern, a lysophosphatidylcholine (LysoPC) was proposed. LysoPC is a precursor of lysophosphatidic acid (LPA) - a known mediator for lung fibrosis with its pathway currently being evaluated as new therapeutic drug target for IPF and other fibrotic diseases.

CONCLUSIONS

We identified a LysoPC by UHPLC-HRMS as potential biomarker in serum of patients with IPF. Further validation studies in a larger cohort are necessary to determine its role in IPF.

TRIAL REGISTRATION

Serum samples from IPF patients have been obtained within the clinical trial NCT02173145 at baseline and from the idiopathic interstitial pneumonia (IIP) cohort study. The study was approved by the Swiss Ethics Committee, Bern (KEK 002/14 and 246/15 or PB_2016-01524).

Serum adenosine deaminase activity in patients with systemic lupus erythematosus: a study based on ADA1 and ADA2 isoenzymes pattern

Adenosine deaminase (ADA) plays a crucial role in the development and maintenance of normal immune system. So, any immunological imbalances could associate with its altered activity in serum. This study evaluated the activity of total ADA and its isoenzymes in serum of 45 patients with systemic lupus erythematosus (SLE). Included were 23 patients with active SLE, 22 during the inactive phase of the disease, and 45 healthy subjects. Our results provided evidence that the significantly elevated total ADA activity in serum of SLE patients is correlated mainly with the increased ADA2 level. The highest mean ADA2 activity during the relapse phase of the disease could be an indication to the macrophages, the main source of ADA2. It might be concluded that ADA and its isoenzymes analysis in serum of patients could be used as a useful and non-invasive diagnostic tool in evaluation of SLE active phase and the disease severity.

Distinct hepatitis B virus dynamics in the immunotolerant and early immunoclearance phases

Little is known about hepatitis B virus (HBV) diversity changes within a host during the immunotolerant phase of chronic HBV infection. Such knowledge, nevertheless, may help in understanding how host immunity and HBV interact at the early stage of infection. In this study, serial serum samples were collected from a long-term (>17 years) follow-up cohort of seven patients, and multiple copies of the full-length viral genome from serially sampled sera were recovered and analyzed. Viral genetic diversity was positively correlated with host immunity, represented by levels of alanine aminotransferase (ALT), but was negatively correlated with the viral copy number. During the immunotolerant phase, when the host immunity was feeble (ALT < 20 U/liter), viral nucleotide diversity decreased while copy numbers increased. Rates of evolutionary change derived for different patients were in a very narrow range (1.6 x 10(-5) to 5.4 x 10(-5)/site/year). As the disease progressed toward the immunoclearance phase (ALT > 20 U/liter), viral diversity increased but copy numbers decreased. Evolutionary rates varied among patients in accordance with their levels of ALT, ranging from 9.6 x 10(-6) to 3.2 x 10(-4)/site/year. More than half (19/32 sites) of positively selected sites resided in immune epitopes, suggesting their possible role in host immunity. Our results demonstrate that host immunity is a dominant factor in HBV evolution. Different selective forces, including immune-mediated positive selection and virus-mediated negative selection, operate in tandem in shaping viral population dynamics within a host.

Distinct hepatitis B virus dynamics in the immunotolerant and early immunoclearance phases

Little is known about hepatitis B virus (HBV) diversity changes within a host during the immunotolerant phase of chronic HBV infection. Such knowledge, nevertheless, may help in understanding how host immunity and HBV interact at the early stage of infection. In this study, serial serum samples were collected from a long-term (>17 years) follow-up cohort of seven patients, and multiple copies of the full-length viral genome from serially sampled sera were recovered and analyzed. Viral genetic diversity was positively correlated with host immunity, represented by levels of alanine aminotransferase (ALT), but was negatively correlated with the viral copy number. During the immunotolerant phase, when the host immunity was feeble (ALT < 20 U/liter), viral nucleotide diversity decreased while copy numbers increased. Rates of evolutionary change derived for different patients were in a very narrow range (1.6 x 10(-5) to 5.4 x 10(-5)/site/year). As the disease progressed toward the immunoclearance phase (ALT > 20 U/liter), viral diversity increased but copy numbers decreased. Evolutionary rates varied among patients in accordance with their levels of ALT, ranging from 9.6 x 10(-6) to 3.2 x 10(-4)/site/year. More than half (19/32 sites) of positively selected sites resided in immune epitopes, suggesting their possible role in host immunity. Our results demonstrate that host immunity is a dominant factor in HBV evolution. Different selective forces, including immune-mediated positive selection and virus-mediated negative selection, operate in tandem in shaping viral population dynamics within a host.