scholarly journals Molecular Responses to High Hydrostatic Pressure in Eukaryotes: Genetic Insights from Studies on Saccharomyces cerevisiae

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1305
Author(s):  
Fumiyoshi Abe

High hydrostatic pressure is common mechanical stress in nature and is also experienced by the human body. Organisms in the Challenger Deep of the Mariana Trench are habitually exposed to pressures up to 110 MPa. Human joints are intermittently exposed to hydrostatic pressures of 3–10 MPa. Pressures less than 50 MPa do not deform or kill the cells. However, high pressure can have various effects on the cell’s biological processes. Although Saccharomyces cerevisiae is not a deep-sea piezophile, it can be used to elucidate the molecular mechanism underlying the cell’s responses to high pressures by applying basic knowledge of the effects of pressure on industrial processes involving microorganisms. We have explored the genes associated with the growth of S. cerevisiae under high pressure by employing functional genomic strategies and transcriptomics analysis and indicated a strong association between high-pressure signaling and the cell’s response to nutrient availability. This review summarizes the occurrence and significance of high-pressure effects on complex metabolic and genetic networks in eukaryotic cells and how the cell responds to increasing pressure by particularly focusing on the physiology of S. cerevisiae at the molecular level. Mechanosensation in humans has also been discussed.

Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 167
Author(s):  
Yi-Yuan Ke ◽  
Yuan-Tay Shyu ◽  
Sz-Jie Wu

Isothiocyanates (ITCs) are important functional components of cruciferous vegetables. The principal isothiocyanate molecule in broccoli is sulforaphane (SFN), followed by erucin (ERN). They are sensitive to changes in temperature, especially high temperature environments where they are prone to degradation. The present study investigates the effects of high hydrostatic pressure on isothiocyanate content, myrosinase activity, and other functional components of broccoli, and evaluates its anti-inflammatory and antioxidant effects. Broccoli samples were treated with different pressures and for varying treatment times; 15 min at 400 MPa generated the highest amounts of isothiocyanates. The content of flavonoids and vitamin C were not affected by the high-pressure processing strategy, whereas total phenolic content (TPC) exhibited an increasing tendency with increasing pressure, indicating that high-pressure processing effectively prevents the loss of the heat-sensitive components and enhances the nutritional content. The activity of myrosinase (MYR) increased after high-pressure processing, indicating that the increase in isothiocyanate content is related to the stimulation of myrosinase activity by high-pressure processing. In other key enzymes, the ascorbate peroxidase (APX) activity was unaffected by high pressure, whereas peroxidase (POD) and polyphenol oxidase (PPO) activity exhibited a 1.54-fold increase after high-pressure processing, indicating that high pressures can effectively destroy oxidases and maintain food quality. With regards to efficacy evaluation, NO production was inhibited and the expression levels of inducible nitric oxide synthase (iNOS) and Cyclooxygenase-2 (COX-2) were decreased in broccoli treated with high pressures, whereas the cell viability remained unaffected. The efficacy was more significant when the concentration of SFN was 60 mg·mL−1. In addition, at 10 mg·mL−1 SFN, the reduced/oxidized glutathione (GSH/GSSG) ratio in inflammatory macrophages increased from 5.99 to 9.41. In conclusion, high-pressure processing can increase the isothiocyanate content in broccoli, and has anti-inflammatory and anti-oxidant effects in cell-based evaluation strategies, providing a potential treatment strategy for raw materials or additives used in healthy foods.


Soft Matter ◽  
2015 ◽  
Vol 11 (11) ◽  
pp. 2125-2138 ◽  
Author(s):  
Yevgeny Moskovitz ◽  
Hui Yang

Our objective was to study molecular processes that might be responsible for inert gas narcosis and high-pressure nervous syndrome.


2020 ◽  
Vol 29 ◽  
pp. 165-173
Author(s):  
A Rodríguez-Illamola ◽  
JM Míguez ◽  
J Coimbra ◽  
JM Wilson

The present study investigates the response of the hormone arginine vasotocin (AVT), the non-mammalian antidiuretic hormone, to the acclimation of fish to high hydrostatic pressure (5.1 MPa). Two fish species with different osmoregulatory strategies, the lesser spotted dogfish Scyliorhinus canicula, a marine osmoconforming chondrichthyan species adapted for migration to deep waters, and the rainbow trout Oncorhynchus mykiss, a pressure-sensitive freshwater species, were selected for study. Fish were exposed to hydrostatic pressures of either 0.1 (control) or 5.1 MPa in hydrostatic chambers for up to 2 wk at their appropriate salinities. Plasma cortisol was measured in trout, and plasma chloride, sodium and potassium were measured in both fish species. A transient high level of plasma AVT was found in dogfish and in trout after 1 and 3 d of exposure to high hydrostatic pressure, which returned to basal levels by 14 d of exposure. In contrast, pituitary AVT content was reduced after short-term exposure in dogfish, while in trout, lower expression was found in high pressure than in control conditions, independently of exposure time. In dogfish, pituitary AVT levels recovered by 14 d under high hydrostatic pressure. No changes in plasma cortisol (trout) or ions (both species) were observed. These initial increases of the AVT release from the pituitary during fish acclimation to high pressure suggest that it works as a physiological short-term response to reduce water loss and equilibrate ion osmotic balance.


1997 ◽  
Vol 60 (1) ◽  
pp. 48-53 ◽  
Author(s):  
J. CARBALLO ◽  
P. FERNANDEZ ◽  
A. V. CARRASCOSA ◽  
M. T. SOLAS ◽  
F. JIMENEZ COLMENERO

The purpose of this study was to analyze the consequences of applying high pressures (100 and 300 MPa for 5 or 20 min) on characteristics such as water- and fat-binding properties, texture, color, microstructure, and microbiology of low-fat (9.2%) and high-fat (20.3%) beef patties. In nonpressurized patties, the low-fat product exhibited significantly poorer (P < 0.05) binding properties and higher (P < 0.05) Kramer shear force and Kramer energy than did high-fat patties. Although high pressure did not clearly influence the binding properties of low- and high-fat beef patties, it did produce a rise in the Kramer shear force and energy which were more pronounced at 300 MPa. High pressures altered patty color, the extent of alteration depending on fat content, pressure, and pressurizing time. Pressurizing high- and low-fat beef patties at 300 MPa not only produced a lethal effect (P < 0.05) on microorganisms, but caused sublethal damage as well.


2013 ◽  
Vol 12 (7) ◽  
pp. 990-997 ◽  
Author(s):  
Asaha Suzuki ◽  
Takahiro Mochizuki ◽  
Satoshi Uemura ◽  
Toshiki Hiraki ◽  
Fumiyoshi Abe

ABSTRACT Cells of Saccharomyces cerevisiae express two tryptophan permeases, Tat1 and Tat2, which have different characteristics in terms of their affinity for tryptophan and intracellular localization. Although the high-affinity permease Tat2 has been well documented in terms of its ubiquitin-dependent degradation, the low-affinity permease Tat1 has not yet been characterized fully. Here we show that a high hydrostatic pressure of 25 MPa triggers a degradation of Tat1 which depends on Rsp5 ubiquitin ligase and the EH domain-containing protein End3. Tat1 was resistant to a 3-h cycloheximide treatment, suggesting that it is highly stable under normal growth conditions. The ubiquitination of Tat1 most likely occurs at N-terminal lysines 29 and 31. Simultaneous substitution of arginine for the two lysines prevented Tat1 degradation, but substitution of either of them alone did not, indicating that the roles of lysines 29 and 31 are redundant. When cells were exposed to high pressure, Tat1-GFP was completely lost from the plasma membrane, while substantial amounts of Tat1 K29R-K31R -GFP remained. The HPG1-1 (Rsp5 P514T ) and rsp5-ww3 mutations stabilized Tat1 under high pressure, but any one of the rsp5-ww1 , rsp5-ww2 , and bul1 Δ bul2 Δ mutations or single deletions of genes encoding arrestin-related trafficking adaptors did not. However, simultaneous loss of 9-arrestins and Bul1/Bul2 prevented Tat1 degradation at 25 MPa. The results suggest that multiple PPxY motif proteins share some essential roles in regulating Tat1 ubiquitination in response to high hydrostatic pressure.


2020 ◽  
Vol 133 (17) ◽  
pp. jcs245555
Author(s):  
Satoshi Uemura ◽  
Takahiro Mochizuki ◽  
Kengo Amemiya ◽  
Goyu Kurosaka ◽  
Miho Yazawa ◽  
...  

ABSTRACTMechanical stresses, including high hydrostatic pressure, elicit diverse physiological effects on organisms. Gtr1, Gtr2, Ego1 (also known as Meh1) and Ego3 (also known as Slm4), central regulators of the TOR complex 1 (TORC1) nutrient signaling pathway, are required for the growth of Saccharomyces cerevisiae cells under high pressure. Here, we showed that a pressure of 25 MPa (∼250 kg/cm2) stimulates TORC1 to promote phosphorylation of Sch9, which depends on the EGO complex (EGOC) and Pib2. Incubation of cells at this pressure aberrantly increased glutamine and alanine levels in the ego1Δ, gtr1Δ, tor1Δ and pib2Δ mutants, whereas the polysome profiles were unaffected. Moreover, we found that glutamine levels were reduced by combined deletions of EGO1, GTR1, TOR1 and PIB2 with GLN3. These results suggest that high pressure leads to the intracellular accumulation of amino acids. Subsequently, Pib2 loaded with glutamine stimulates the EGOC–TORC1 complex to inactivate Gln3, downregulating glutamine synthesis. Our findings illustrate the regulatory circuit that maintains intracellular amino acid homeostasis and suggest critical roles for the EGOC–TORC1 and Pib2–TORC1 complexes in the growth of yeast under high hydrostatic pressure.


2014 ◽  
Vol 77 (10) ◽  
pp. 1664-1668 ◽  
Author(s):  
TANYA D'SOUZA ◽  
MUKUND KARWE ◽  
DONALD W. SCHAFFNER

Peanut butter has been associated with several large foodborne salmonellosis outbreaks. This research investigates the potential of high hydrostatic pressure processing (HPP) for inactivation of Salmonella in peanut butter of modified composition, both by modifying its water activity as well by the addition of various amounts of nisin. A cocktail of six Salmonella strains associated with peanut butter and nut-related outbreaks was used for all experiments. Different volumes of sterile distilled water were added to peanut butter to increase water activity, and different volumes of peanut oil were added to decrease water activity. Inactivation in 12% fat, light roast, partially defatted peanut flour, and peanut oil was also quantified. Nisaplin was incorporated into peanut butter at four concentrations corresponding to 2.5, 5.0, 12.5, and 25.0 ppm of pure nisin. All samples were subjected to 600 MPa for 18 min. A steady and statistically significant increase in log reduction was seen as added moisture was increased from 50 to 90%. The color of all peanut butter samples containing added moisture contents darkened after high pressure processing. The addition of peanut oil to further lower the water activity of peanut butter further reduced the effectiveness of HPP. Just over a 1-log reduction was obtained in peanut flour, while inactivation to below detection limits (2 log CFU/g) was observed in peanut oil. Nisin alone without HPP had no effect. Recovery of Salmonella after a combined nisin and HPP treatment did show increased log reduction with longer storage times. The maximum log reduction of Salmonella achieved was 1.7 log CFU/g, which was comparable to that achieved by noncycling pressure treatment alone. High pressure processing alone or with other formulation modification, including added nisin, is not a suitable technology to manage the microbiological safety of Salmonella-contaminated peanut butter.


2005 ◽  
Vol 71 (1) ◽  
pp. 339-343 ◽  
Author(s):  
Kevin R. Calci ◽  
Gloria K. Meade ◽  
Robert C. Tezloff ◽  
David H. Kingsley

ABSTRACT Previous results demonstrated that hepatitis A virus (HAV) could be inactivated by high hydrostatic pressure (HHP) (D. H. Kingsley, D. Hoover, E. Papafragkou, and G. P. Richards, J. Food Prot. 65:1605-1609, 2002); however, direct evaluation of HAV inactivation within contaminated oysters was not performed. In this study, we report confirmation that HAV within contaminated shellfish is inactivated by HHP. Shellfish were initially contaminated with HAV by using a flowthrough system. PFU reductions of >1, >2, and >3 log10 were observed for 1-min treatments at 350, 375, and 400 megapascals, respectively, within a temperature range of 8.7 to 10.3�C. Bioconcentration of nearly 6 log10 PFU of HAV per oyster was achieved under simulated natural conditions. These results suggest that HHP treatment of raw shellfish will be a viable strategy for the reduction of infectious HAV.


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