Effect of NaCl Treatments on Tyramine Biosynthesis of Enterococcus faecalis

2015 ◽  
Vol 78 (5) ◽  
pp. 940-945 ◽  
Author(s):  
FANG LIU ◽  
XINXIN WANG ◽  
LIHUI DU ◽  
DAOYING WANG ◽  
YONGZHI ZHU ◽  
...  

The effect of NaCl stress (0 to 8%, wt/vol) on the growth and tyramine production in two Enterococcus faecalis strains was examined during culture time. The growth of E. faecalis was inhibited by the increase in NaCl concentration, but tyramine production was unaffected. Tyramine accumulated rapidly during the logarithmic phase of the strains, and the final tyramine levels were approximately 800 μg/ml. Relative gene expression of four genes in the tyrosine decarboxylase locus, namely, tyrRS, tyrDC, tyrP, and nhaC, was evaluated at different incubation times. The results showed that NaCl stress could upregulate the expression of tyrDC and tyrP to improve the tyramine production of a single E. faecalis strain under certain conditions, and TyrS could act as a negative regulator on the genetic regulation of the tyramine cluster.

2021 ◽  
Vol 11 (15) ◽  
pp. 7144
Author(s):  
Muriel C. Bischof ◽  
Sonja Häckel ◽  
Andrea Oberli ◽  
Andreas S. Croft ◽  
Katharina A. C. Oswald ◽  
...  

Increasing evidence implicates intervertebral disc (IVD) degeneration as a major contributor to low back pain. In addition to a series of pathogenic processes, degenerated IVDs become vascularized in contrast to healthy IVDs. In this context, angiopoietin (Ang) plays a crucial role and is involved in cytokine recruitment, and anabolic and catabolic reactions within the extracellular matrix (ECM). Over the last decade, a progenitor cell population has been described in the nucleus pulposus (NP) of the IVD to be positive for the Tie2 marker (also known as Ang-1 receptor). In this study, we investigated the influence of Ang-1 and Ang-2 on human NP cell (Tie2+, Tie2- or mixed) populations isolated from trauma patients during 7 days in normoxia (21% O2) or hypoxia (≤ 5% O2). At the end of the process, the proliferation and metabolic activity of the NP cells were analyzed. Additionally, the relative gene expression of NP-related markers was evaluated. NP cells showed a higher proliferation depending on the Ang treatment. Moreover, the study revealed higher NP cell metabolism when cultured in hypoxia. Additionally, the relative gene expression followed, with an increase linked to the oxygen level and Ang concentration. Our study comparing different NP cell populations may be the start of new approaches for the treatment of IVD degeneration.


Author(s):  
D.L. Silva ◽  
B.R. Carvalho ◽  
H.C. Ferreira Júnior ◽  
H.C. Oliveira ◽  
C.R. Ferreira ◽  
...  

Author(s):  
Rajnics P ◽  
◽  
Kellner A ◽  
Nagy F ◽  
Alföldi V ◽  
...  

Purpose: Elevated level of Lipocalin-2 (LCN2), a new acute phase adipokine, was described after ischemic stroke. A number of researchers feel as though that LCN2 originated from the infiltrating neutrophils and other cells in brain after stroke. Others measured elevated LCN2 expression in arteriosclerotic plaque. Therefore we have investigated LCN2 relative gene expression level of blood neutrophil granulocytes in patients with ischemic stroke to assess if elevated LCN2 is the cause or consequence of ischemic stroke. Methods: Laboratory and anamnestic data were collected, which could have a role in development of thrombo-embolic events in patients with ischemic stroke. RNA based method was used to evaluate the relative gene expression level of LCN2. We calculated Odds Ratio (OR) and Confidence Interval (CI) for the association between LCN2 and ischemic stroke. Results: 34 samples were available for evaluation. The LCN 2 relative gene expression level was decreased in 12 cases. In this group, 91% of patients have Atrial Fibrillation (AF) at the time of hospitalisation. The mean LCN2 relative gene expression value was 64.25% (ranges: 34%-115%) in patients with AF. It was significantly lower than in patients with normal sinus rhythm (409.2%; ranges: 127%-1127%; p=0.0003). The elevated LCN2 relative gene expression level significantly (p=0.012) increases the risk of stroke (OR: 12.6) independently from other factors. Conclusions: High LCN2 expression level seems to have strong positive predictive value on ischemic stroke, and may be useful in thrombotic risk stratification of plaque vulnerability in these patients.


2020 ◽  
pp. 1-12 ◽  
Author(s):  
Ayman H. Abd El-Aziz ◽  
Nagwa I. El-Kasrawy ◽  
Mohamed E. Abd El-Hack ◽  
Sherif Z. Kamel ◽  
Usama E. Mahrous ◽  
...  

2020 ◽  
Vol 51 (7) ◽  
pp. 2997-3006
Author(s):  
Laura Alvarez‐Lee ◽  
Alejandra García‐Gasca ◽  
Sergio Martínez‐Díaz ◽  
Neftalí Gutiérrez‐Rivera

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