108 Preferential loading of thermal stress-associated microRNAs into extracellular vesicles: attempt to mitigate effects of heat stress in bovine granulosa cells

2022 ◽  
Vol 34 (2) ◽  
pp. 291
Author(s):  
N. G. Menjivar ◽  
S. Gebremedhn ◽  
D. Tesfaye
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
Extracellular Vesicles ◽  
Granulosa Cells

PSX-A-19 Late-Breaking: Potential application of granulosa cell derived extracellular vesicles to mitigate the effects of heat stress in bovine oocytes

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 369-369
Author(s):  
Nico G Menjivar ◽  
Samuel Gebremedhn ◽  
Dawit Tesfaye
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
Granulosa Cell ◽  
Extracellular Vesicles ◽  
Granulosa Cells ◽  
Bystander Effect ◽  
Thermal Conditions ◽  
Developmental Competence ◽  
Cumulus Expansion

Abstract Environmental heat stress negatively affects reproductive efficiency by disrupting follicular development, ultimately compromising gamete competency in cattle. Recently, outlined through the bystander effect, granulosa cell derived extracellular vesicles (EVs) were found to suppress negative effects of recurrent heat stress in recipient bovine granulosa cells. Here, we aimed to assess the effects of supplementing granulosa cell derived EVs during bovine in vitro maturation (IVM) on developmental competence following thermal stress. For this, we modeled a cell culture protocol to generate EVs from bovine granulosa cells subjected to differing ambient temperatures, 38.5°C (body temperature) vs. 42°C (heat stress). At the time of IVM, experimental cumulus oocyte complexes (COCs) were arranged in a 2 x 3 factorial design for temperature (38.5°C or 41°C) versus EV supplementation (normal EVs, stressed EVs and non-supplemented controls) at 20% of the IVM media. Following an initial 8h priming period, half the COCs were subjected to heat shock, the others remained at normal temperature to complete IVM. Results indicate that EV supplementation increased cumulus expansion and the expression of cumulus expansion genes (PTX3, PTGS2 and EGFR). Cleavage rates were increased when supplemented with normal (90.2±1.4%; P = 0.023) or stressed (89.8±2.9%; P = 0.029) EVs, compared to the non-supplemented control (80.5±1.5%) under non-thermal conditions. Similarly, exposure to recurrent thermal stress, cleavage rates were (91±0.9%) and (89±0.6%) when supplemented with normal and stressed EVs respectively, compared to the non-supplemented control (88.5±2.5%). In the absence of exposure to recurrent heat stress, blastocysts rates were (32.4±3.5%) and (31.3±2.9%) when COCs were supplemented with normal and stressed EVs, compared to the control (20.7±4.4%). Blastocysts rates were (23.3±4.7%) and (22.5±3.2%) when COCs were supplemented with normal and stressed EVs, compared to the control (15.5±4.5%) when exposed to recurrent thermal stress. In conclusion, granulosa cell derived EVs have potential to induce oocyte tolerance against recurrent thermal stress.

259 The Role of Extracellular Vesicles in Mitigating the Effect of Heat Stress

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 132-133
Author(s):  
Dawit Tesfaye
Keyword(s):  
Oxidative Stress ◽  
Heat Stress ◽  
Extracellular Vesicles ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Biological Fluids ◽  
Biologically Active ◽  
Molecular Signals

Abstract Environmental heat stress negatively affects the fertility of dairy cows by disrupting reproductive processes spanning from follicular development to maternal recognition of pregnancy. Investigation of cellular level responses to stress would contribute to the understanding of the mechanism behind survival responses. Extracellular vesicles (EVs), which carry biologically active signaling molecules, are reported to play a significant role in the cellular response to stress. They are produced by almost all types of cells and abundantly present in various biological fluids including follicular fluid, oviductal fluid, uterine fluids in vivo, and in spent culture media in vitro. Those EV-coupled molecular signals in biological fluids are indicative of the physiological status of the cells of their origin. This has been evidenced by the presence of EV-mediated miRNA signals in follicular fluid associated with the metabolic status of cows. Recent studies revealed the potential role of follicular fluid EVs in carrying molecular signals which can reverse or protect the damage incurred by heat stress in bovine oocytes. In addition to cellular defense responses (activation of HSP70 and HSP90, NRF2 and GRP78 & 94), bovine granulosa cells exposed to heat stress in vitro released EVs enriched with selected mRNA (HSP90 and SOD1) and miRNAs. Among others, miR-1246, miR-374a, and miR-2904 were found to be enriched in EVs released from granulosa cells exposed to thermal stress. Those miRNAs were found to regulate pathways related to heat and endoplasmic reticulum stress responses. The priming of recipient bovine granulosa cells by EVs derived from heat-stressed granulosa cells induced tolerance against recurrent heat stress. Collectively, EV-mediated molecular signals would provide another layer of cell-to-cell communication and deliver protective signals against oxidative stress to recipient cells. This would provide opportunities for future potential application of EVs in tackling oxidative stress-associated fertility problems in humans and animals.

scholarly journals Extracellular vesicles shuttle protective messages against heat stress in bovine granulosa cells

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Samuel Gebremedhn ◽  
Ahmed Gad ◽  
Hoda Samir Aglan ◽  
Jozef Laurincik ◽  
Radek Prochazka ◽  
...  
Keyword(s):  
Heat Stress ◽  
Extracellular Vesicles ◽  
Granulosa Cells ◽  
Beef Cows ◽  
Protective Role ◽  
Bioactive Molecules ◽  
Follicular Cells ◽  
Vitro Model

Abstract Elevated summer temperature is reported to be the leading cause of stress in dairy and beef cows, which negatively affects various reproductive functions. Follicular cells respond to heat stress (HS) by activating the expression of heat shock family proteins (HSPs) and other antioxidants. HS is reported to negatively affect the bi-directional communication between the follicular cells and the oocyte, which is partly mediated by follicular fluid extracellular vesicles (EVs) released from surrounding cells. As carriers of bioactive molecules (DNA, RNA, protein, and lipids), the involvement of EVs in mediating the stress response in follicular cells is not fully understood. Here we used an in vitro model to decipher the cellular and EV-coupled miRNAs of bovine granulosa cells in response to HS. Moreover, the protective role of stress-related EVs against subsequent HS was assessed. For this, bovine granulosa cells from smaller follicles were cultured in vitro and after sub-confluency, cells were either kept at 37 °C or subjected to HS (42 °C). Results showed that granulosa cells exposed to HS increased the accumulation of ROS, total oxidized protein, apoptosis, and the expression of HSPs and antioxidants, while the viability of cells was reduced. Moreover, 14 and 6 miRNAs were differentially expressed in heat-stressed granulosa cells and the corresponding EVs, respectively. Supplementation of stress-related EVs in cultured granulosa cells has induced adaptive response to subsequent HS. However, this potential was not pronounced when the cells were kept under 37 °C. Taking together, EVs generated from granulosa cells exposed to HS has the potential to shuttle bioactive molecules to recipient cells and make them robust to subsequent HS.

Heme oxygenase 1 regulates apoptosis induced by heat stress in bovine ovarian granulosa cells via the ERK1/2 pathway

2018 ◽  
Vol 234 (4) ◽  
pp. 3961-3972 ◽  
Author(s):  
Yi-Ru Wang ◽  
Kun-Lin Chen ◽  
Cheng-Min Li ◽  
Lian Li ◽  
Gen-Lin Wang
Keyword(s):  
Heat Stress ◽  
Heme Oxygenase ◽  
Granulosa Cells ◽  
Heme Oxygenase 1 ◽  
Ovarian Granulosa Cells

scholarly journals Transcriptional, Mitochondrial Activity, and Viability of Egyptian Buffalo’s Granulosa Cells In Vitro Cultured under Heat Elevation

2021 ◽  
Vol 11 (2) ◽  
pp. 193-201
Author(s):  
Nasser Ghanem ◽  
Marwa Said Faheem ◽  
Romysa Samy ◽  
Ashraf Hesham Barkawi
Keyword(s):  
Heat Stress ◽  
Granulosa Cells ◽  
Transcriptional Activity ◽  
The Other ◽  
Control Group ◽  
Mitochondrial Activity ◽  
Fluorescent Intensity ◽  
Stressed Group ◽  
Other Hand

It is documented that heat stress caused impairment on the reproductive performance of dairy animals. However, there are few reports that have focused on the molecular and intracellular responses of in vitro cultured buffalo granulosa cells during heat elevation. The present study was conducted to investigate the effect of heat elevation during in vitro culture of buffalo granulosa cells on their viability, quality, mitochondrial activity, and transcriptional activity. Granulosa cells were harvested after aspiration of cumulus-oocytes complexes that were collected from abattoir ovaries. The granulosa cells were cultured in vitro either at a normal physiological temperature suitable for oocyte maturation and embryo development (38.5°C) or exposed to the elevated temperature of 40.5°C on day 3 of culture (the first two days were for confluence) for two hours of culture then continued at 38.5°C up to day 7 of culture. The viability of granulosa cells was measured using trypan blue and quality was estimated by measuring the level of intracellular reactive oxygen species (ROS) on day 7. Moreover, metabolic activity was performed by measuring the fluorescent intensity of mitochondria. Moreover, transcriptional activity was done by profiling four selected candidate genes using quantitative real-time PCR. The results indicated that the granulosa cells viability rate significantly decreased in the heat stress group (25.1 ± 3.7), compared to the control group (36.6 ± 5.3) on confluence day (day 3). In addition, the viability rate on the last day of culture (day 7) decreased in heat stress, compared to control (83.7 ± 4.5 and 97.4 ± 0.4, respectively). On the other hand, there was a nonsignificant difference in ROS profile between the control (21.7*104 ± 1.3) and the heat-stressed group (15.7 ± 0.7) on day 7 of culture. However, the mitochondrial fluorescent intensity was higher in the control (21.9 ± 1.9) than in the heat-stressed group (15.4 ± 0.8) on day 7 of culture. The expression of cellular defense (HSF1) and apoptosis-inducing gene (P53) were significantly up-regulated in granulosa cells exposed to heat elevation, compared to the control group. On the other hand, the steroidogenesis-regulating gene (StAR) was down-regulated in granulosa cells cultured under heat shock, compared to the control group. In conclusion, heat stress reduced the viability of granulosa cells by inducing the expression of an apoptosis-related gene (P53) and compromised expression of genes regulating the steroid biosynthesis, which resulted in up-regulation of cell defense gene (HSF1) in an attempt to ameliorate the deleterious effect of heat stress on the biological activity of the granulosa cells.

scholarly journals Heat stress diminishes gonadotropin receptor expression and enhances susceptibility to apoptosis of rat granulosa cells

Reproduction ◽  
2005 ◽  
Vol 129 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Takashi Shimizu ◽  
Izumi Ohshima ◽  
Manabu Ozawa ◽  
Satoko Takahashi ◽  
Atsushi Tajima ◽  
...  
Keyword(s):  
Heat Stress ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Follicular Development ◽  
Receptor Expression ◽  
Female Rats ◽  
Aromatase Activity ◽  
Mrna Levels ◽  
Gonadotropin Receptor ◽  
Estradiol Levels

Heat stress inhibits ovarian follicular development in mammalian species. We hypothesized that heat stress inhibits the function of follicular granulosa cells and suppresses follicular development. To test this, immature female rats were injected with pregnant mare serum gonadotropin (PMSG) at 48 h after the start of temperature treatment (control: 25 °C, 50% RH; heat stress: 35 °C, 70% Relative Humidity). The ovaries and granulosa cells of follicles at different developmental stages were analyzed for gonadotropin receptor levels and aromatase activity; estradiol levels were measured in follicular fluid. Before injection, heat stress diminished only the amount of FSH receptor on granulosa cells of antral follicles. During PMSG-stimulated follicular development, heat stress strongly inhibited gonadotropin receptor levels and aromatase activity in granulosa cells, and estradiol levels in the follicular fluid of early antral, antral and preovulatory follicles. To examine apoptosis and mRNA levels of bcl-2 and bax in granulosa cells, follicles harvested 48 h after PMSG injection were cultured in serum-free conditions. Heat-stressed granulosa cells showed a time-dependent increase in apoptosis. The bcl-2 mRNA levels were similar in control and heat-stressed granulosa cells; bax mRNA levels were increased in heat-stressed granulosa cells. According to these results, heat stress inhibits expression of gonadotropin receptors in granulosa cells and attenuates estrogenic activity of growing follicles, granulosa cells of heat-stressed follicles are susceptible to apoptosis, and the bcl2/bax system is not associated with heat-stress-induced apoptosis of granulosa cells. Our study suggests that decreased numbers and function of granulosa cells may cause ovarian dysfunction in domestic animals in summer.

scholarly journals Verification of Heat Stress Thresholds for a Health-Based Heat-Wave Definition

2019 ◽  
Vol 58 (6) ◽  
pp. 1177-1194 ◽  
Author(s):  
Claudia Di Napoli ◽  
Florian Pappenberger ◽  
Hannah L. Cloke
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
Excess Mortality ◽  
Heat Waves ◽  
Warning System ◽  
High Heat ◽  
Probability Of Detection ◽  
Climate Index ◽  
Test Bed ◽  
Maximum Heat

AbstractHeat waves represent a threat to human health and excess mortality is one of the associated negative effects. A health-based definition for heat waves is therefore relevant, especially for early warning purposes, and it is here investigated via the universal thermal climate index (UTCI). The UTCI is a bioclimate index elaborated via an advanced model of human thermoregulation that estimates the thermal stress induced by air temperature, wind speed, moisture, and radiation on the human physiology. Using France as a test bed, the UTCI was computed from meteorological reanalysis data to assess the thermal stress conditions associated with heat-attributable excess mortality in five cities. UTCI values at different climatological percentiles were defined and evaluated in their ability to identify periods of excess mortality (PEMs) over 24 years. Using verification metrics such as the probability of detection (POD), the false alarm ratio (FAR), and the frequency bias (FB), daily minimum and maximum heat stress levels equal to or above corresponding UTCI 95th percentiles (15° ± 2°C and 34.5° ± 1.5°C, respectively) for 3 consecutive days are demonstrated to correlate to PEMs with the highest sensitivity and specificity (0.69 ≤ POD ≤ 1, 0.19 ≤ FAR ≤ 0.46, 1 ≤ FB ≤ 1.48) than minimum, maximum, and mean heat stress level singularly and other bioclimatological percentiles. This finding confirms the detrimental effect of prolonged, unusually high heat stress at day- and nighttime and suggests the UTCI 95th percentile as a health-meaningful threshold for a potential heat-health watch warning system.

scholarly journals Transcriptomic Responses to Thermal Stress and Varied Phosphorus Conditions in Fugacium kawagutii

2019 ◽  
Vol 7 (4) ◽  
pp. 96 ◽  
Author(s):  
Senjie Lin ◽  
Liying Yu ◽  
Huan Zhang
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
Molecular Mechanisms ◽  
Organic Phosphorus ◽  
Phosphorus Deficiency ◽  
Dual Algorithm ◽  
Quantitative Expression ◽  
Wide Range ◽  
Transcriptomic Responses ◽  
Major Nutrients

Coral reef-associated Symbiodiniaceae live in tropical and oligotrophic environments and are prone to heat and nutrient stress. How their metabolic pathways respond to pulses of warming and phosphorus (P) depletion is underexplored. Here, we conducted RNA-seq analysis to investigate transcriptomic responses to thermal stress, phosphate deprivation, and organic phosphorus (OP) replacement in Fugacium kawagutii. Using dual-algorithm (edgeR and NOIseq) to remedy the problem of no replicates, we conservatively found 357 differentially expressed genes (DEGs) under heat stress, potentially regulating cell wall modulation and the transport of iron, oxygen, and major nutrients. About 396 DEGs were detected under P deprivation and 671 under OP utilization, both mostly up-regulated and potentially involved in photosystem and defensome, despite different KEGG pathway enrichments. Additionally, we identified 221 genes that showed relatively stable expression levels across all conditions (likely core genes), mostly catalytic and binding proteins. This study reveals a wide range of, and in many cases previously unrecognized, molecular mechanisms in F. kawagutii to cope with heat stress and phosphorus-deficiency stress. Their quantitative expression dynamics, however, requires further verification with triplicated experiments, and the data reported here only provide clues for generating testable hypotheses about molecular mechanisms underpinning responses and adaptation in F. kawagutii to temperature and nutrient stresses.

scholarly journals Effects of oocyte‐derived paracrine factors on release of extracellular vesicles by murine mural granulosa cells in vitro

2020 ◽  
Vol 91 (1) ◽  
Author(s):  
Yuta Matsuno ◽  
Natsumi Maruyama ◽  
Wataru Fujii ◽  
Kunihiko Naito ◽  
Koji Sugiura
Keyword(s):  
Extracellular Vesicles ◽  
Granulosa Cells ◽  
Paracrine Factors

scholarly journals Future Changes in Human-Biometeorological Index Classes in Three Regions of Luxembourg, Western-Central Europe

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hanna Leona Lokys ◽  
Jürgen Junk ◽  
Andreas Krein
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Stress ◽  
Thermal Comfort ◽  
Central Europe ◽  
Spatial Resolution ◽  
Climate Index ◽  
Human Thermal Comfort ◽  
Air Temperatures ◽  
The Impact

Projected climate change will cause increasing air temperatures affecting human thermal comfort. In the highly populated areas of Western-Central Europe a large population will be exposed to these changes. In particular Luxembourg—with its dense population and the large cross-border commuter flows—is vulnerable to changing thermal stress. Based on climate change projections we assessed the impact of climate change on human thermal comfort over the next century using two common human-biometeorological indices, the Physiological Equivalent Temperature and the Universal Thermal Climate Index. To account for uncertainties, we used a multimodel ensemble of 12 transient simulations (1971–2098) with a spatial resolution of 25 km. In addition, the regional differences were analysed by a single regional climate model run with a spatial resolution of 1.3 km. For the future, trends in air temperature, vapour pressure, and both human-biometeorological indices could be determined. Cold stress levels will decrease significantly in the near future up to 2050, while the increase in heat stress turns statistically significant in the far future up to 2100. This results in a temporarily reduced overall thermal stress level but further increasing air temperatures will shift the thermal comfort towards heat stress.

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