Probiotic properties of Lactobacillus isolates originating from porcine intestine and feces

In this study, a total of 94 lactic acid bacterial (LAB) isolates of porcine small intestinal and fecal origin were screened for their probiotic properties. The aim was to evaluate whether their isolation site and putative species identity play a role in these characteristics and whether either of these can be used as a predictive factor for the probiotic potential of bacterial isolates. The isolates were preliminarily identified by partial 16S rRNA gene sequencing and characterized in vitro for their pH and bile tolerance, adhesion capacity towards porcine enterocytes isolated from five intestinal sites and for antimicrobial activity towards five indicator pathogens. The interdependence of these characteristics was statistically evaluated. The isolates tolerated low pH and bile well. Adherence to the enterocytes of different origins did not correlate with the strain isolation site. In general, higher adherence was observed to colon cells in comparison to the small intestinal enterocytes. Culture filtrates of the isolates caused a decrease of up to three orders of magnitude in the intestinal pathogen cell numbers. The inhibition was mostly due to lactic and other organic acids. The predominating phylotypes identified were Lactobacillus reuteri and Lactobacillus salivarius, of which the former generally had the best adhesion capacity, whereas the latter appeared to be the best inhibitor. Based on the results, several strains of the pig Lactobacillus isolates tested may function as promising candidates for use in probiotic products. However, it was not possible to use the isolation site or the species identity of the isolates as reliable preliminary screening factors.     

The PI3K/Akt/mTOR Pathway Is Implicated in the Premature Senescence of Primary Human Endothelial Cells Exposed to Chronic Radiation

The etiology of radiation-induced cardiovascular disease (CVD) after chronic exposure to low doses of ionizing radiation is only marginally understood. We have previously shown that a chronic low-dose rate exposure (4.1 mGy/h) causes human umbilical vein endothelial cells (HUVECs) to prematurely senesce. We now show that a dose rate of 2.4 mGy/h is also able to trigger premature senescence in HUVECs, primarily indicated by a loss of growth potential and the appearance of the senescence-associated markers ß-galactosidase (SA-ß-gal) and p21. In contrast, a lower dose rate of 1.4 mGy/h was not sufficient to inhibit cellular growth or increase SA-ß-gal-staining despite an increased expression of p21. We used reverse phase protein arrays and triplex Isotope Coded Protein Labeling with LC-ESI-MS/MS to study the proteomic changes associated with chronic radiation-induced senescence. Both technologies identified inactivation of the PI3K/Akt/mTOR pathway accompanying premature senescence. In addition, expression of proteins involved in cytoskeletal structure and EIF2 signaling was reduced. Age-related diseases such as CVD have been previously associated with increased endothelial cell senescence. We postulate that a similar endothelial aging may contribute to the increased rate of CVD seen in populations chronically exposed to low-dose-rate radiation.     

Early Life Origins Cognitive Decline: Findings in Elderly Men in the Helsinki Birth Cohort Study

Objectives

To examine whether the adverse effects of slow prenatal and postnatal growth on cognitive function persist to old age and predict age related cognitive decline.

Design and Setting

A longitudinal birth cohort study of men born in Helsinki, Finland 1934-44.

Participants

Nine-hundred-thirty-one men of the Helsinki Birth Cohort Study, with detailed data on growth from birth to adulthood, aged 20.1 (SD = 1.4) at the first and 67.9 (SD = 2.5) years at the second cognitive testing.

Main Outcome Measures

The Finnish Defense Forces Basic Intellectual Ability Test assessed twice over nearly five decades apart.

Results

Lower weight, length and head circumference at birth were associated with lower cognitive ability at 67.9 years (1.04–1.55 points lower ability per each standard deviation [SD] unit decrease in body size, 95% Confidence Interval [95%CI]: 0.05 to 2.72) and with cognitive decline after 20.1 years (0.07–0.11 SD decline over time per each SD decrease in body size, 95%CI:0.00 to 0.19). Men who were born larger were more likely to perform better in the cognitive ability test over time (1.22–1.43 increase in odds to remain in the top relative to the lower two thirds in ability over time per each SD increase in body size, 95%CI:1.04 to 1.79) and were more resilient to cognitive decline after 20.1 years (0.69 to 0.76 decrease in odds to decline from than remain in the top third of ability over time per each SD increase in body size, 95%CI:0.49 to 0.99). Slower growth between birth and two years in weight, height and body mass index was associated with lower cognitive ability at 67.9 years, but not with cognitive decline.

Conclusions

Poorer lifetime cognitive ability is predicted by slower growth before and after birth. In predicting resilience to age related cognitive decline, the period before birth seems to be more critical.     

Integrative proteomic and microRNA analysis of primary human coronary artery endothelial cells exposed to low-dose gamma radiation

High doses of ionising radiation significantly increase the risk of cardiovascular disease (CVD), the vascular endothelium representing one of the main targets. Whether radiation doses lower than 500 mGy induce cardiovascular damage is controversial. The aim of this study was to investigate radiation-induced expression changes on protein and microRNA (miRNA) level in primary human coronary artery endothelial cells after a single 200 mGy radiation dose (Co-60). Using a multiplex gel-based proteomics technology (2D-DIGE), we identified 28 deregulated proteins showing more than ±1.5-fold expression change in comparison with non-exposed cells. A great majority of the proteins showed up-regulation. Bioinformatics analysis indicated “cellular assembly and organisation, cellular function and maintenance and molecular transport” as the most significant radiation-responsive network. Caspase-3, a central regulator of this network, was confirmed to be up-regulated using immunoblotting. We also analysed radiation-induced alterations in the level of six miRNAs known to play a role either in CVD or in radiation response. The expression of miR-21 and miR-146b showed significant radiation-induced deregulation. Using miRNA target prediction, three proteins found differentially expressed in this study were identified as putative candidates for miR-21 regulation. A negative correlation was observed between miR-21 levels and the predicted target proteins, desmoglein 1, phosphoglucomutase and target of Myb protein. This study shows for the first time that a low-dose exposure has a significant impact on miRNA expression that is directly related to protein expression alterations. The data presented here may facilitate the discovery of low-dose biomarkers of radiation-induced cardiovascular damage.     

Low-dose irradiation causes rapid alterations to the proteome of the human endothelial cell line EA.hy926

High doses of ionising radiation damage the heart by an as yet unknown mechanism. A concern for radiological protection is the recent epidemiological data indicating that doses as low as 100-500 mGy may induce cardiac damage. The aim of this study was to identify potential molecular targets and/or mechanisms involved in the pathogenesis of low-dose radiation-induced cardiovascular disease. The vascular endothelium plays a pivotal role in the regulation of cardiac function and is therefore a potential target tissue. We report here that low-dose radiation induced rapid and time-dependent changes in the cytoplasmic proteome of the human endothelial cell line EA.hy926. The proteomes were investigated at 4 and 24 h after irradiation at two different dose rates (Co-60 gamma ray total dose 200 mGy; 20 mGy/min and 190 mGy/min) using 2D-DIGE technology. Differentially expressed proteins were identified, after in-gel trypsin digestion, by MALDI-TOF/TOF tandem mass spectrometry, and peptide mass fingerprint analyses. We identified 15 significantly differentially expressed proteins, of which 10 were up-regulated and 5 down-regulated, with more than ±1.5-fold difference compared with unexposed cells. Pathways influenced by the low-dose exposures included the Ran and RhoA pathways, fatty acid metabolism and stress response.     

Proteomic analysis by SILAC and 2D-DIGE reveals radiation-induced endothelial response: four key pathways

Epidemiological data show that ionising radiation increases the risk of cardiovascular disease. The endothelium is one of the main targets of radiation-induced damage. Rapid radiation-induced alterations in the biological processes were investigated after exposure to a clinically relevant radiation dose (2.5 Gy gamma radiation). The changes in protein expression were determined using the human endothelial cell line EA.hy926 as a model. Two complementary proteomic approaches, SILAC (Stable Isotope Labelling with Amino acids in Cell culture) and 2D-DIGE (Two Dimensional Difference-in-Gel-Electrophoresis) were used. The proteomes of the endothelial cells were analysed 4h and 24h after irradiation. Differentially expressed proteins were identified and quantified by MALDI-TOF/TOF and LTQ Orbitrap tandem mass spectrometry. The deregulated proteins were mainly categorised in four key pathways: (i) glycolysis/gluconeogenesis and synthesis/degradation of ketone bodies, (ii) oxidative phosphorylation, (iii) Rho-mediated cell motility and (iv) non-homologous end joining. We suggest that these alterations facilitate the repair processes needed to overcome the stress caused by irradiation and are indicative of the vascular damage leading to radiation-induced cardio- and cerebrovascular impairment.