Thermogenic capacity of human white-fat: the actual picture

Presented at the 9th Greek Conference of Biochemistry and Physiology of Exercise, Thessaloniki, Greece, 18–20 October 2019Cold exposure and exercise may increase thermogenic capacity of white adipose tissue (WAT), which could subsequently enhance energy expenditure and body weight loss. We aimed to identify possible alterations in uncoupling protein 1 (UCP1)—the main biomarker of thermogenic activation—in human WAT due to both cold exposure and exercise, as well as the link between environmental temperature and thermogenic capacity of human WAT. MATERIAL & METHOD: We conducted four human experimental studies and two systematic reviews and meta-analyses—PROSPERO registration CRD42019120116, CRD42019120213. RESULTS: UCP1 mRNA was higher in winter than in summer [t(30) = 2.232, p = 0.03] in human WAT and our meta-analysis showed a main effect of cold exposure on human UCP1 mRNA [standard mean difference (Std-md) = 1.81, confidence interval (CI) = 0.50–3.13, p = 0.007]. However, UCP1 mRNA/protein expressions displayed no associations with %fat mass or BMI (p > 0.05, Cohen’s f2 < 0.20). Both a 2-hour cooling and a non-cooling protocol preceding the positron emission tomography/computed tomography (PET/CT) measurements revealed no association between environmental temperature and standardised uptake value (SUVmax) of human WAT, as well as no mean differences in SUVmax-WAT-activity between winter and summer. An 8-week exercise program had no effect on UCP1 of human WAT or on body composition. Our meta-analysis also revealed: (a) no effect of chronic exercise on human UCP1 mRNA, (b) a main effect of chronic exercise on UCP1 protein concentrations (Std-md = 0.59, CI = 0.03–1.16, p = 0.04) and UCP1 mRNA (Std-md = 1.76, CI = 0.48–3.04, p = 0.007) in WAT of normal diet animals, c) a main effect of chronic exercise on UCP1 mRNA (Std-md = 2.94, CI = 0.24–5.65, p = 0.03) and UCP1 protein concentrations (Std-md = 2.06, CI = 0.07–4.05, p = 0.04) of high-fat diet animals. CONCLUSIONS: Cold exposure represents a main stimulus for increased thermogenic capacity in human white adipocytes; however, this may have no impact on body weight loss. Chronic exercise may represent no major stimulus for UCP1 induced in human white adipocytes, while in animals it increases UCP1 gene independently of their diet. Therefore, evidence from animal studies regarding UCP1 gene activation in white adipocytes may not be applicable in humans. Finally, the identification of human WAT thermogenic capacity via PET/CT examination may be optimal with both a cooling and a non-cooling protocol.Published onlin

The Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex in Aspergillus nidulans

Extent: 6p.A mutation screen in Aspergillus nidulans uncovered mutations in the acdX gene that led to altered repression by acetate, but not by glucose. AcdX of A. nidulans is highly conserved with Spt8p of Saccharomyces cerevisiae, and since Spt8p is a component of the Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex, the SAGA complex may have a role in acetate repression in A. nidulans. We used a bioinformatic approach to identify genes encoding most members of the SAGA complex in A. nidulans, and a proteomic analysis to confirm that most protein components identified indeed exist as a complex in A. nidulans. No apparent compositional differences were detected in mycelia cultured in acetate compared to glucose medium. The methods used revealed apparent differences between Yeast and A. nidulans in the deubiquitination (DUB) module of the complex, which in S. cerevisiae consists of Sgf11p, Sus1p, and Ubp8p. Although a convincing homologue of S. cerevisiae Ubp8p was identified in the A. nidulans genome, there were no apparent homologues for Sus1p and Sgf11p. In addition, when the SAGA complex was purified from A. nidulans, members of the DUB module were not co-purified with the complex, indicating that functional homologues of Sus1p and Sgf11p were not part of the complex. Thus, deubiquitination of H2B-Ub in stress conditions is likely to be regulated differently in A. nidulans compared to S. cerevisiae.Paraskevi Georgakopoulos, Robin A. Lockington, Joan M. Kell

Regulation of carbon catabolite repression in the filamentous fungus Aspergillus nidulans.

In Aspergillus nidulans, acetate is a repressing carbon source that leads to similar levels of CreA mediated repression as glucose. acdX was identified in a mutation screen in Aspergillus nidulans to identify genes involved in acetate repression but not in glucose repression. The conservation of the amino acid sequence of AcdX of A. nidulans and Spt8 of Saccharomyces cerevisiae suggests that the SAGA (Spt-Ada-Gcn5-Acetyltransferase) complex may have a role in acetate repression in A. nidulans, since Spt8 is a component of the SAGA complex. We also made mutations in sptC, homologous to the yeast SAGA component gene SPT3, which show a similar phenotype to the acdX mutants. The SAGA complex is highly conserved from yeast to humans. In yeast it is involved mostly in the regulation of highly regulated genes that respond to environmental stresses, such as metabolic starvation, DNA damage and heat. SAGA in yeast has been shown to have positive and negative functions on transcription. Bioinformatic analysis indicates that the components of the SAGA complex are also present in A. nidulans. CreA has been shown to repress the expression of the alc regulon, which is required for the ethanol utilization pathway. Although plate tests indicated that acdX and sptC null mutations led to derepressed alcohol dehydrogensed activity, RT-qPCR showed no derepression of alcA or aldA, but rather elevated induced levels. Our results indicate that acetate repression is due to repression via CreA together with metabolic changes, rather than due to an independent regulatory control mechanism. Furthermore experiments were undertaken to confirm the existence of the SAGA complex in A. nidulans. SptC was N terminally tagged with the TAP tag to allow the purification of the SAGA complex. Proteomic analysis indicates that the SAGA complex does exist in A.nidulans, although there are some differences, one of which is that it lacks the deubiquitinating subgroup.Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 201

Digital Transformation of the Greek Banking Sector in the COVID Era

Rapid developments in digital innovation and technology in recent decades have marked a transition into the fourth industrial revolution (and the fifth social revolution), causing a significant impact on all areas of human activity. Moreover, these developments have been strongly felt with the advent of the COVID pandemic. The COVID pandemic has acted as a catalyst for imminent changes within the operational models of banks and their digitization, both locally and internationally, dealing with this peculiar crisis as an opportunity rather than a threat. In this study, after conducting a bibliographic overview of the key literature, an analysis of the digital development that took place in the banking sector in Greece was conducted, comparing the views of bank customers to those of bank employees and investigating the key factors that are believed to have a positive and/or negative effect on the use of new digital banking products and services, as well as the influence of factors determining digital banking expansion (gender, age, educational level, pandemic, etc.). The results revealed that bank customers were quite satisfied and familiar with digital transactions and wished to expand their use, while they considered the possibility of 24/7 service as an important factor in choosing to use digital banking, and the factors for expanding their use were transaction speed, transaction security, and information security. However, bank employees accept digital transformation positively and believe that for it to be successful, additional and ongoing training is required to upgrade their digital skills, which will also contribute to culture change and adaptation to the digital era. Furthermore, the age and educational level of bank customers had a statistically significant effect on the growing acceptance and expansion of the banking sector’s digital transformation. A comparison of the correlations of the demographic data with answers given by bank employees did not reveal any significant variations regarding the findings given by bank customers. These findings can be useful for bank management policy-making issues, for banks and their supervising authorities to build KPIs to monitor and assess the digitalization progress, and for academics for further research, especially as the COVID pandemic ensues and the need for digital solutions is all the more urgent, marking the digital competition between banks as one of increasing intensity

SAGA complex purification.

<p>a) Tandem affinity purification of a strain containing SptC tagged with the TAP tag (Lane 1) and a strain with wildtype SptC (Lane 2). The gel regions that were purified are numbered, and the <i>S. cerevisiae</i> homologues of the SAGA complex components identified in <i>A. nidulans</i> by LC MS are shown on the right. b) Tandem affinity purification of the N-TAP<i>sptC</i>;MYC<i>acdX</i>;<i>nkuAΔ</i> strain grown in media containing either 1% glucose (Lane 1), 50 mM arabinose (Lane 2) or 50 mM sodium acetate pH 6.0 (Lane 3). LC-MS was performed for all three conditions in this experiment. c) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065221#pone-0065221-g002" target="_blank">Figure 2c</a> shows one of a further two repeat experiments, designed specifically to determine whether the differences in staining intensity around 50KDa in lane 3 of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065221#pone-0065221-g002" target="_blank">Figure 2b</a> were robustly repeatable, showing that the apparent differences in part b are an artifact.</p

The SAGA complex components present in the <i>A. nidulans</i> genome.

a<p>Functions of the <i>S. cerevisiae</i> SAGA complex subunits.</p>b<p><i>S. cerevisiae</i> homologues identified in <i>A. nidulans.</i></p>c<p><i>A. nidulans</i> accession number.</p><p>References: RfeE <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065221#pone.0065221-Malavazi1" target="_blank">[38]</a>, AdaB and GcnE <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065221#pone.0065221-ReyesDominguez1" target="_blank">[16]</a>, AcdX and SptC <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065221#pone.0065221-Georgakopoulos1" target="_blank">[21]</a>.</p

Oligonucleotide primers used in this study.

<p>Oligonucleotide primers used in this study.</p

Complementation of the <i>sptCΔ</i>^MYC<i>acdXnkuAΔ</i> by p^N−TAPSPTC.

<p><i>sptCΔ</i>^MYC<i>acdXnkuAΔ</i> protoplasts plated on osmotically stabilised minimum medium, after 3 days growth at 37°C. <b>A)</b> No DNA control. <b>B)</b> Transformed with p^{N<b>−</b>TAP}SPTC; arrow indicates complemented transformant.</p

Attitudes and Practices Related to COVID-19 Vaccination with the Second Booster Dose among Members of Athens Medical Association: Results from a Cross-Sectional Study

Background: There are limited data on the attitudes and acceptance of the second booster (fourth dose) of the COVID-19 vaccination among physicians. Methods: A cross-sectional, questionnaire-based, online study was conducted among members of the Athens Medical Association (A.M.A.) who were invited to participate anonymously over the period from January to March 2023. Results: From the 1224 members who participated in the survey, 53.9% did not receive the fourth dose of the COVID-19 vaccine. The main reasons for no vaccination were the lack of obligation to receive the fourth dose, the history of three doses of the COVID-19 vaccine and the lack of sufficient information about the effectiveness of the fourth dose. Over half of the three-dose-vaccinated participants were willing to receive the fourth dose in the near future. Interestingly, the vaccination coverage among participants who had been informed about the fourth dose through scientific sources was low. Conclusions: The low vaccination coverage with the fourth dose reported in this study can lead to broad and serious consequences, such as increase in COVID-19 infections, reduction of available healthcare staff and increased caseloads of COVID-19 in hospitals. Furthermore, hesitant physicians will adversely influence the vaccination uptake among the general population due to their key role in informing and recommending the vaccine. The healthcare system administration should acknowledge and address physician’s concerns through effective communication and better support