18 research outputs found

    A Neuroprotective Bovine Colostrum Attenuates Apoptosis in Dexamethasone-Treated MC3T3-E1 Osteoblastic Cells

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    Glucocorticoid-induced osteoporosis (GIO) is one of the most common secondary forms of osteoporosis. GIO is partially due to the apoptosis of osteoblasts and osteocytes. In addition, high doses of dexamethasone (DEX), a synthetic glucocorticoid receptor agonist, induces neurodegeneration by initiating inflammatory processes leading to neural apoptosis. Here, a neuroprotective bovine colostrum against glucocorticoid-induced neuronal damage was investigated for its anti-apoptotic activity in glucocorticoid-treated MC3T3-E1 osteoblastic cells. A model of apoptotic osteoblastic cells was developed by exposing MC3T3-E1 cells to DEX (0–700 μM). Colostrum co-treated with DEX was executed at 0.1–5.0 mg/mL. Cell viability was measured for all treatment schedules. Caspase-3 activation was assessed to determine both osteoblast apoptosis under DEX exposure and its potential prevention by colostrum co-treatment. Glutathione reduced (GSH) was measured to determine whether DEX-mediated oxidative stress-driven apoptosis is alleviated by colostrum co-treatment. Western blot was performed to determine the levels of p-ERK1/2, Bcl-XL, Bax, and Hsp70 proteins upon DEX or DEX plus colostrum exposure. Colostrum prevented the decrease in cell viability and the increase in caspase-3 activation and oxidative stress caused by DEX exposure. Cells, upon colostrum co-treated with DEX, exhibited higher levels of p-ERK1/2 and lower levels of Bcl-XL, Bax, and Hsp70. Our data support the notion that colostrum may be able to reduce DEX-induced apoptosis possibly via the activation of the ERK pathway and modulation of the Hsp70 system. We provided preliminary evidence on how bovine colostrum, as a complex and multi-component dairy product, in addition to its neuroprotective action, may affect osteoblastic cell survival undergoing apoptosis

    SARS-CoV-2 sero-surveillance in Greece: evolution over time and epidemiological attributes during the pre-vaccination pandemic era

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    BACKGROUND: Nation-wide SARS-CoV-2 seroprevalence surveys provide valuable insights into the course of the pandemic, including information often not captured by routine surveillance of reported cases. METHODS: A serosurvey of IgG antibodies against SARS-CoV-2 was conducted in Greece between March and December 2020. It was designed as a cross-sectional survey repeated at monthly intervals. The leftover sampling methodology was used and a geographically stratified sampling plan was applied. RESULTS: Of 55,947 serum samples collected, 705 (1.26%) were found positive for anti-SARS-CoV-2 antibodies, with higher seroprevalence (9.09%) observed in December 2020. Highest seropositivity levels were observed in the "0-29" and "30-49" year age groups. Seroprevalence increased with age in the "0-29" age group. Highly populated metropolitan areas were characterized with elevated seroprevalence levels (11.92% in Attica, 12.76% in Thessaloniki) compared to the rest of the country (5.90%). The infection fatality rate (IFR) was estimated at 0.451% (95% CI: 0.382-0.549%) using aggregate data until December 2020, and the ratio of actual to reported cases was 9.59 (7.88-11.33). CONCLUSIONS: The evolution of seroprevalence estimates aligned with the course of the pandemic and varied widely by region and age group. Young and middle-aged adults appeared to be drivers of the pandemic during a severe epidemic wave under strict policy measures

    Bovine colostrum supplementation improves bone metabolism in an osteoporosis-induced animal model

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    Osteoporosis is characterized by bone loss. The present study aims to investigate the effects of bovine colostrum (BC) on bone metabolism using ovariectomized (OVX) and orchidectomized (ORX) rat models. Twenty-seven-week-old Wistar Han rats were randomly assigned as: (1) placebo control, (2) BC supplementation dose 1 (BC1: 0.5 g/day/OVX, 1 g/day/ORX), (3) BC supplementation dose 2 (BC2: 1 g/day/OVX, 1.5 g/day/ORX) and (4) BC supplementation dose 3 (BC3: 1.5 g/day/OVX, 2 g/day/ORX). Bone microarchitecture, strength, gene expression of VEGFA, FGF2, RANKL, RANK and OPG, and bone resorption/formation markers were assessed after four months of BC supplementation. Compared to the placebo, OVX rats in the BC1 group exhibited significantly higher cortical bone mineral content and trabecular bone mineral content (p < 0.01), while OVX rats in the BC3 group showed significantly higher trabecular bone mineral content (p < 0.05). ORX rats receiving BC dose 2 demonstrated significantly higher levels of trabecular bone mineral content (p < 0.05). Serum osteocalcin in the ORX was pointedly higher in all BC supplementation groups than the placebo (BC1: p < 0.05; BC2, BC3: p < 0.001). Higher doses of BC induced significantly higher relative mRNA expression of OPG, VEGFA, FGF2 and RANKL (p < 0.05). BC supplementation improves bone metabolism of OVX and ORX rats, which might be associated with the activation of the VEGFA, FGF2 and RANKL/RANK/OPG pathways.EC -European Commission(778277

    Browning formation markers of subcutaneous adipose tissue in relation to resting energy expenditure, physical activity and diet in humans

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    © 2017 Walter de Gruyter GmbH, Berlin/Boston. Regular exercise and diet may contribute to white adipose tissue (WAT) conversion into a brown adipose-like phenotype that may increase resting energy expenditure (REE), leading to weight loss. We examined the relationship between REE, physical activity (PA) participation and diet with browning formation markers of subcutaneous WAT in healthy men. We assessed REE, diet and body composition of 32 healthy men [age (years): 36.06 ± 7.36, body mass index (BMI): 27.06 ± 4.62 (kg/m 2 )]. Participants also underwent measurements of PA [metabolic equivalent (MET)-min/week] using the International Physical Activity Questionnaire (IPAQ), while they undertook a subcutaneous fat biopsy from the abdominal region to assess the mRNA expressions of uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), peroxisome proliferator-activated receptor alpha (PPARα) and peroxisome proliferator-activated receptor gamma (PPARγ). We found no associations between the UCP1, PGC-1α, PPARα and PPARγ mRNAs with REE, PA levels and diet (p > 0.05). However, the PGC-1α, PPARα and PPARγ mRNAs were more expressed in individuals displaying moderate rather than low PA levels (p < 0.05). Furthermore, PGC-1α, PPARα and PPARγ mRNAs were negatively correlated with fat mass percentage (p < 0.05). PGC-1α and PPARα mRNAs were also negatively correlated with BMI, while PGC-1α mRNA was inversely associated with waist-to-hip ratio (p < 0.05). REE, PA levels and diet are not associated with browning formation indices of subcutaneous adipose tissue in healthy adult men.This study was supported by funding from the European Union 7th Framework Program (FP7-PEOPLE-2012-IRSES grant 319010; FP7-PEOPLE-2013-IRSES grant 612547). A.V. was supported by funding from the Education and Lifelong Learning Programme of the Greek Ministry of Education, Co-financed by Greece and the European Union (NSRF 2007–2013, IRAKLITOS II, grant 162).Published versio

    Human white-fat thermogenesis: Experimental and meta-analytic findings

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    © 2020 The Authors. Published by Taylor & Francis. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1080/23328940.2020.1769530White adipose tissue (WAT) thermogenic activity may play a role in whole-body energy balance and two of its main regulators are thought to be environmental temperature (Tenv) and exercise. Low Tenv may increase uncoupling protein one (UCP1; the main biomarker of thermogenic activity) in WAT to regulate body temperature. On the other hand, exercise may stimulate UCP1 in WAT, which is thought to alter body weight regulation. However, our understanding of the roles (if any) of Tenv and exercise in WAT thermogenic activity remains incomplete. Our aim was to examine the impacts of low Tenv and exercise on WAT thermogenic activity, which may alter energy homeostasis and body weight regulation. We conducted a series of four experimental studies, supported by two systematic reviews and meta-analyses. We found increased UCP1 mRNA (p = 0.03; but not protein level) in human WAT biopsy samples collected during the cold part of the year, a finding supported by a systematic review and meta-analysis (PROSPERO review protocol: CRD42019120116). Additional clinical trials (NCT04037371; NCT04037410) using Positron Emission Tomography/Computed Tomography (PET/CT) revealed no impact of low Tenv on human WAT thermogenic activity (p > 0.05). Furthermore, we found no effects of exercise on UCP1 mRNA or protein levels (p > 0.05) in WAT biopsy samples from a human randomized controlled trial (Clinical trial: NCT04039685), a finding supported by systematic review and meta-analytic data (PROSPERO review protocol: CRD42019120213). Taken together, the present experimental and meta-analytic findings of UCP1 and SUVmax, demonstrate that cold and exercise may play insignificant roles in human WAT thermogenic activity. Abbreviations: WAT:White adipose tissue; Tenv: Environmental temperature; UCP1: Uncoupling protein one; BAT: Brown adipose tissue; BMI:Body mass index; mRNA: Messenger ribonucleic acid; RCT: Randomized controlled trial; WHR: Waist-to-hip ratio; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-analyses; PET/CT: Positron Emission Tomography and Computed Tomography; REE: Resting energy expenditure; 18F-FDG: F18 fludeoxyglucose; VO2peak:Peak oxygen consumption; 1RM: One repetition maximum; SUVmax: Maximum standardized uptake value; Std: Standardized mean difference.This work was supported by funding from the European Union 7th Framework Program FP7-PEOPLE-2012-IRSES grant no. [319010]; FP7-PEOPLE-2013-IRSES grant no. [612547] and Horizon 2020 ICI-THROUGH grant no [645710].Published versio

    Acción anti-apoptótica de un calostro bovino en un modelo celular de osteoporosis

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    La osteoporosis inducida por glucocorticoides es una de las formas secundarias más comunes de osteoporosis, debida en parte a la apoptosis de osteoblastos y osteocitos. En el presente trabajo, se han investigado los efectos de un calostro bovino en un modelo celular de osteoporosis obtenido a partir de la exposición de células osteoblásticas MC3T3-E1 a la DEX, en un rango de concentración (0-700 μM). El co-tratamiento de las células con el calostro bovino se realizó a una concentración de 0,1-5,0 mg/mL. Se determinó la activación de la caspasa-3 para evaluar el grado de apoptosis de los osteoblastos bajo la exposición a DEX y su posible prevención mediante el co-tratamiento con calostro. Se midieron los niveles de glutation reducido (GSH) para determinar si la apoptosis mediada por el estrés oxidativo de la DEX se veía disminuida por el co-tratamiento con calostro. Finalmente, mediante Western blot, se determinaron los niveles de las proteínas p-ERK1/2, Bcl-XL, Bax y Hsp70 tras la exposición a DEX o DEX más calostro. El calostro evitó la disminución de la viabilidad celular y el aumento de la activación de la caspasa-3 y el estrés oxidativo, causados por la exposición a la DEX. Las células sometidas a un tratamiento conjunto de calostro y DEX mostraron mayores niveles de p-ERK1/2 y menores niveles de Bcl-XL, Bax y Hsp70. Estos resultados prueban que el calostro posee capacidad de reducir la apoptosis inducida por DEX posiblemente a través de la activación de la vía ERK y la modulación del sistema Hsp70

    Towards model-based online monitoring of cyclist's head thermal comfort: Smart Helmet concept and prototype

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    Bicyclists can be subjected to crashes, which can cause injuries over the whole body, especially the head. Head injuries can be prevented by wearing bicycle helmets; however, bicycle helmets are frequently not worn due to a variety of reasons. One of the most common complaints about wearing bicycle helmets relates to thermal discomfort. So far, insufficient attention has been given to the thermal performance of helmets. This paper aimed to introduce and develop an adaptive model for the online monitoring of head thermal comfort based on easily measured variables, which can be measured continuously using impeded sensors in the helmet. During the course of this work, 22 participants in total were subjected to different levels of environmental conditions (air temperature, air velocity, mechanical work and helmet thermal resistance) to develop a general model to predict head thermal comfort. A reduced-order general linear regression model with three input variables, namely, temperature difference between ambient temperature and average under-helmet temperature, cyclist's heart rate and the interaction between ambient temperature and helmet thermal resistance, was the most suitable to predict the cyclist's head thermal comfort and showed maximum mean absolute percentage error (MAPE) of 8.4%. Based on the selected model variables, a smart helmet prototype (SmartHelmet) was developed using impeded sensing technology, which was used to validate the developed general model. Finally, we introduced a framework of calculation for an adaptive personalised model to predict head thermal comfort based on streaming data from the SmartHelmet prototype. © 2019 by the authors

    A neuroprotective bovine colostrum attenuates apoptosis in dexamethasone‐treated mc3t3‐e1 osteoblastic cells

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    Glucocorticoid‐induced osteoporosis (GIO) is one of the most common secondary forms of osteoporosis. GIO is partially due to the apoptosis of osteoblasts and osteocytes. In addition, high doses of dexamethasone (DEX), a synthetic glucocorticoid receptor agonist, induces neurodegeneration by initiating inflammatory processes leading to neural apoptosis. Here, a neuroprotective bovine colostrum against glucocorticoid‐induced neuronal damage was investigated for its anti‐apoptotic activity in glucocorticoid‐treated MC3T3‐E1 osteoblastic cells. A model of apoptotic osteoblastic cells was developed by exposing MC3T3‐E1 cells to DEX (0–700 μM). Colostrum co‐treated with DEX was executed at 0.1–5.0 mg/mL. Cell viability was measured for all treatment schedules. Caspase‐3 activation was assessed to determine both osteoblast apoptosis under DEX exposure and its potential prevention by colostrum co‐treatment. Glutathione reduced (GSH) was measured to determine whether DEX‐mediated oxidative stress‐driven apoptosis is alleviated by colostrum co‐treatment. Western blot was performed to determine the levels of p‐ERK1/2, Bcl‐XL, Bax, and Hsp70 proteins upon DEX or DEX plus colostrum exposure. Colostrum prevented the decrease in cell viability and the increase in caspase‐3 activation and oxidative stress caused by DEX exposure. Cells, upon colostrum co‐treated with DEX, exhibited higher levels of p‐ERK1/2 and lower levels of Bcl‐XL, Bax, and Hsp70. Our data support the notion that colostrum may be able to reduce DEX‐induced apoptosis possibly via the activation of the ERK pathway and modulation of the Hsp70 system. We provided preliminary evidence on how bovine colostrum, as a complex and multi‐component dairy product, in addition to its neuroprotective action, may affect osteoblastic cell survival undergoing apoptosis. © 2021 by the authors

    Browning formation markers of subcutaneous adipose tissue in relation to resting energy expenditure, physical activity and diet in humans

    No full text
    Regular exercise and diet may contribute to white adipose tissue (WAT) conversion into a brown adipose-like phenotype that may increase resting energy expenditure (REE), leading to weight loss. We examined the relationship between REE, physical activity (PA) participation and diet with browning formation markers of subcutaneous WAT in healthy men. We assessed REE, diet and body composition of 32 healthy men [age (years): 36.06 ± 7.36, body mass index (BMI): 27.06 ± 4.62 (kg/m2)]. Participants also underwent measurements of PA [metabolic equivalent (MET)-min/week] using the International Physical Activity Questionnaire (IPAQ), while they undertook a subcutaneous fat biopsy from the abdominal region to assess the mRNA expressions of uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), peroxisome proliferator-activated receptor alpha (PPARα) and peroxisome proliferator-activated receptor gamma (PPARγ). We found no associations between the UCP1, PGC-1α, PPARα and PPARγ mRNAs with REE, PA levels and diet (p &gt; 0.05). However, the PGC-1α, PPARα and PPARγ mRNAs were more expressed in individuals displaying moderate rather than low PA levels (p &lt; 0.05). Furthermore, PGC-1α, PPARα and PPARγ mRNAs were negatively correlated with fat mass percentage (p &lt; 0.05). PGC-1α and PPARα mRNAs were also negatively correlated with BMI, while PGC-1α mRNA was inversely associated with waist-to-hip ratio (p &lt; 0.05). REE, PA levels and diet are not associated with browning formation indices of subcutaneous adipose tissue in healthy adult men. © 2017 Walter de Gruyter GmbH, Berlin/Boston
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