scholarly journals Maladaptation of trout spermatozoa to fresh water is related to oxidative stress and proteome changes

Reproduction ◽  
2019 ◽  
Vol 157 (6) ◽  
pp. 485-499 ◽  
Author(s):  
J Nynca ◽  
M Słowińska ◽  
S Judycka ◽  
A Ciereszko

Rainbow trout sperm are ‘maladapted’ to freshwater spawning, resulting in shorter duration of sperm motility in fresh water compared to buffered saline solution. We hypothesized that different sperm motility-activating media have various effects on sperm motility characteristics and oxidative stress, as well as on the protein profiles of rainbow trout sperm. We designed an experimental model for activation of rainbow trout sperm motility in different osmotic conditions: (i) isosmotic and (ii) hypoosmotic. Spermatozoa activation with hypoosmotic solution was associated with lower values for sperm motility parameters (52%) and an induced increase in ROS level (19.4%) in comparison to isosmotic activation with isosmotic solution (67 and 9.5% for sperm motility and ROS, respectively). Hypoosmotic activation resulted in a higher number of differentially abundant sperm proteins (out of which 50 were identified) compared to isosmotic conditions, where only two spots of protein disulfide-isomerase 6 were changed in abundance. The proteins are mainly involved in the TCA cycle, tight and gap junction signaling, Sertoli cell–Sertoli cell junction signaling and asparagine degradation. Our results, for the first time, indicate that during hypoosmotic activation of sperm motility, osmotic stress triggers oxidative stress and disturbances mostly to structural proteins and metabolic enzymes. Our results strongly suggest that comparative physiological and biochemical analysis of rainbow trout sperm characteristics in isosmotic and hypoosmotic conditions could be a useful model for studying the mechanism of sperm activation in salmonid fish.

2018 ◽  
Vol 30 (1) ◽  
pp. 213
Author(s):  
M. Á. Peralta-Martínez ◽  
S. R. García ◽  
M. E. Kjelland ◽  
H. González-Márquez

Rainbow trout (Oncorhynchus mykiss) sperm extender protocols can differ considerably with regards to composition of the extenders and handling. The objective of this study was to determine the effect of pH for 5 extenders on rainbow trout sperm motility and activation during storage at 5°C. Two-year-old sexually mature rainbow trout males (n = 46) weighing 1.5 to 2.5 kg were caught at Aquaculture Farm Tatakay in Jilotzingo, Estado de México, México. One semen sample per male was collected by abdominal massage. For the experiments, 100 mL of each extender (306, 512, Mounibs, Erdahl and Graham, and Hanks’ Balanced Salt Solution) was made, with pH adjusted to 6 levels (7.0, 7.2, 7.4, 7.8, 8.0, and 8.2). To evaluate pH dynamics in each extender, pH was tested daily over an 8-day storage interval. Trout sperm was added to each of the extenders in a ratio of 1:1 and motility recorded. Afterwards, each activator solution [DIA 532, saline solution (0.85%) and pond water] was added separately to a sample of the extended sperm, to initiate sperm activation. Motility was evaluated subjectively at 400× and monitored until ~99% of the sperm stopped moving (on average, in 40 s). A one-way ANOVA was used and statistical differences were set at α < 0.05. Extender 512 activated sperm motility when pH was >7.4, whereas extender 306 activated motility at every pH. Hanks’ Balanced Salt Solution activated motility at very low percentages for various pH levels, whereas Mounibs and Erdahal and Graham solutions did not activate motility for any pH tested. The 512 extender with a pH of 7 performed best (P < 0.05) as a storage solution, producing a sperm motility of 54% after activation using DIA 532. These results demonstrated the importance of evaluating effects of sperm extender pH over both short- and medium-term storage.


2021 ◽  
Author(s):  
Tianxia Xiao ◽  
Artem Khan ◽  
Yihui Shen ◽  
Li Chen ◽  
Joshua Rabinowitz

Abstract Ethanol and lactate are typical waste products of glucose fermentation. In mammals, glucose is catabolized by glycolysis into circulating lactate, which is broadly used throughout the body as a carbohydrate fuel. Individual cells can both uptake and excrete lactate, uncoupling glycolysis from glucose oxidation. Here we show that similar uncoupling occurs in the yeast Saccharomyces cerevisiae. Even in fermenting yeast that are net releasing ethanol, media 13C-ethanol rapid enters and is oxidized to acetaldehyde and acetyl-CoA. This is evident in exogenous ethanol being a major source of both cytosolic and mitochondrial acetyl units. 2H-tracing reveals that ethanol is also a major source of both NADH and NADPH, and this role is augmented under oxidative stress conditions. Thus, uncoupling of glycolysis from the oxidation of glucose-derived carbon via rapid reversible reactions is an ancient and conserved feature of eukaryotic metabolism.


Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1259
Author(s):  
Huiying Zhang ◽  
Yang Liu ◽  
Lingling Zhou ◽  
Shaohua Xu ◽  
Cheng Ye ◽  
...  

In fish, sperm motility activation is one of the most essential procedures for fertilization. Previous studies have mainly focused on the external environmental effects and intracellular signals in sperm activation; however, little is known about the metabolic process of sperm motility activation in fish. In the present study, using ricefield eel (Monopterus albus) sperm as a model, metabonomics was used to analyze the metabolic mechanism of the sperm motility activation in fish. Firstly, 529 metabolites were identified in the sperm of ricefield eel, which were clustered into the organic acids, amino acids, nucleotides, benzene, and carbohydrates, respectively. Among them, the most abundant metabolites in sperm were L-phenylalanine, DL-leucine, L-leucine, lysolecithin choline 18:0, L-tryptophan, adenine, hypoxanthine, 7-Methylguanine, shikimic acid, and L-tyrosine. Secondly, compared to pre-activated sperm, the level of S-sulfo-L-cysteine and L-asparagine were both increased in the post-activated sperm. Ninety-two metabolites were decreased in the post-activated sperm, including quinic acid, acetylsalicylic acid, 7,8-dihydro L-biopterin, citric acid, glycylphenylalanine, and dihydrotachysterol (DHT). Finally, basing on the pathway analysis, we found that the changed metabolites in sperm motility activation were mainly clustered into energy metabolism and anti-oxidative stress. Fish sperm motility activation would be accompanied by the release of a large amount of energy, which might damage the genetic material of sperm. Thus, the anti-oxidative stress function is a critical process to maintain the normal physiological function of sperm.


2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Katie C Lee ◽  
Allison L Williams ◽  
Ralph V Shohet

Introduction: Pyruvate kinase (Pkm1) directs pyruvate to the TCA cycle for oxidative metabolism in the healthy heart. Our lab described a hypoxia-mediated switch to the alternatively spliced isoform Pkm2, enhancing pyruvate to lactate conversion. Recently, we have also found that Pkm2 knockout (KO) mice had profound depletion of basal glucose in the heart compared to control mice. Pkm2 has also been shown to reduce oxidative damage and promote cardiomyocyte cell proliferation after myocardial infarction (MI). We hypothesize that the upregulation of Pkm2 alters metabolic pathways after injury to promote glycolysis and preserve ATP production in hypoxia, which protects the heart from the stresses of hypoxia and injury. Methods: Global Pkm2 KO mice were subjected to permanent ligation of the left anterior descending coronary artery to mimic an MI. RNA-seq analysis of left ventricles from control (n=8) and Pkm2 KO mice (n=8) before and 3 days after sham or MI surgery was performed. Semiquantitative real-time PCR (qPCR) was used to confirm changes in selected genes of interest. Results: Loss of Pkm2 did not alter gene expression substantially at baseline. 68 genes were differentially expressed in Pkm2 KO hearts after MI (q<0.05, FDR<0.05) not observed in control MI hearts. MI in Pkm2 KO hearts resulted in considerable reduction of transcripts of enzymes in the insulin signaling pathway, mitochondrial oxidative phosphorylation, fatty acid metabolism, and increase in transcripts encoding enzymes in the pentose phosphate pathway, response to oxidative stress, and apoptotic signaling. qPCR of selected genes involved in glucose metabolism confirmed RNA-seq results. Conclusions: RNA-seq analysis of Pkm2 KO hearts demonstrated that loss of Pkm2 altered gene expression of metabolic and mitochondrial enzymes. Conversely, Pkm2 KO hearts showed increased abundance of pro-apoptotic markers which may be a result of increased oxidative stress.


Author(s):  
Rita Meyer ◽  
Zoltan Posalaky ◽  
Dennis Mcginley

The Sertoli cell tight junctional complexes have been shown to be the most important structural counterpart of the physiological blood-testis barrier. In freeze etch replicas they consist of extensive rows of intramembranous particles which are not only oriented parallel to one another, but to the myoid layer as well. Thus the occluding complex has both an internal and an overall orientation. However, this overall orientation to the myoid layer does not seem to be necessary to its barrier function. The 20 day old rat has extensive parallel tight junctions which are not oriented with respect to the myoid layer, and yet they are inpenetrable by lanthanum. The mechanism(s) for the control of Sertoli cell junction development and orientation has not been established, although such factors as the presence or absence of germ cells, and/or hormones, especially FSH have been implicated.


2020 ◽  
Author(s):  
Riccardo Mobili ◽  
Sonia La Cognata ◽  
Francesca Merlo ◽  
Andrea Speltini ◽  
Massimo Boiocchi ◽  
...  

<div> <p>The extraction of the succinate dianion from a neutral aqueous solution into dichloromethane is obtained using a lipophilic cage-like dicopper(II) complex as the extractant. The quantitative extraction exploits the high affinity of the succinate anion for the cavity of the azacryptate. The anion is effectively transferred from the aqueous phase, buffered at pH 7 with HEPES, into dichloromethane. A 1:1 extractant:anion adduct is obtained. Extraction can be easily monitored by following changes in the UV-visible spectrum of the dicopper complex in dichloromethane, and by measuring the residual concentration of succinate in the aqueous phase by HPLC−UV. Considering i) the relevance of polycarboxylates in biochemistry, as e.g. normal intermediates of the TCA cycle, ii) the relevance of dicarboxylates in the environmental field, as e.g. waste products of industrial processes, and iii) the recently discovered role of succinate and other dicarboxylates in pathophysiological processes including cancer, our results open new perspectives for research in all contexts where selective recognition, trapping and extraction of polycarboxylates is required. </p> </div>


2021 ◽  
Vol 22 (5) ◽  
pp. 2746
Author(s):  
Dimitri Shcherbakov ◽  
Reda Juskeviciene ◽  
Adrián Cortés Sanchón ◽  
Margarita Brilkova ◽  
Hubert Rehrauer ◽  
...  

Mitochondrial misreading, conferred by mutation V338Y in mitoribosomal protein Mrps5, in-vivo is associated with a subtle neurological phenotype. Brain mitochondria of homozygous knock-in mutant Mrps5V338Y/V338Y mice show decreased oxygen consumption and reduced ATP levels. Using a combination of unbiased RNA-Seq with untargeted metabolomics, we here demonstrate a concerted response, which alleviates the impaired functionality of OXPHOS complexes in Mrps5 mutant mice. This concerted response mitigates the age-associated decline in mitochondrial gene expression and compensates for impaired respiration by transcriptional upregulation of OXPHOS components together with anaplerotic replenishment of the TCA cycle (pyruvate, 2-ketoglutarate).


GeroScience ◽  
2021 ◽  
Author(s):  
Paul S. Brookes ◽  
Ana Gabriela Jimenez

AbstractAmong several animal groups (eutherian mammals, birds, reptiles), lifespan positively correlates with body mass over several orders of magnitude. Contradicting this pattern are domesticated dogs, with small dog breeds exhibiting significantly longer lifespans than large dog breeds. The underlying mechanisms of differing aging rates across body masses are unclear, but it is generally agreed that metabolism is a significant regulator of the aging process. Herein, we performed a targeted metabolomics analysis on primary fibroblasts isolated from small and large breed young and old dogs. Regardless of size, older dogs exhibited lower glutathione and ATP, consistent with a role for oxidative stress and bioenergetic decline in aging. Furthermore, several size-specific metabolic patterns were observed with aging, including the following: (i) An apparent defect in the lower half of glycolysis in large old dogs at the level of pyruvate kinase. (ii) Increased glutamine anaplerosis into the TCA cycle in large old dogs. (iii) A potential defect in coenzyme A biosynthesis in large old dogs. (iv) Low nucleotide levels in small young dogs that corrected with age. (v) An age-dependent increase in carnitine in small dogs that was absent in large dogs. Overall, these data support the hypothesis that alterations in metabolism may underlie the different lifespans of small vs. large breed dogs, and further work in this area may afford potential therapeutic strategies to improve the lifespan of large dogs.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 762
Author(s):  
Edward V. Prochownik ◽  
Huabo Wang

Pyruvate occupies a central metabolic node by virtue of its position at the crossroads of glycolysis and the tricarboxylic acid (TCA) cycle and its production and fate being governed by numerous cell-intrinsic and extrinsic factors. The former includes the cell’s type, redox state, ATP content, metabolic requirements and the activities of other metabolic pathways. The latter include the extracellular oxygen concentration, pH and nutrient levels, which are in turn governed by the vascular supply. Within this context, we discuss the six pathways that influence pyruvate content and utilization: 1. The lactate dehydrogenase pathway that either converts excess pyruvate to lactate or that regenerates pyruvate from lactate for use as a fuel or biosynthetic substrate; 2. The alanine pathway that generates alanine and other amino acids; 3. The pyruvate dehydrogenase complex pathway that provides acetyl-CoA, the TCA cycle’s initial substrate; 4. The pyruvate carboxylase reaction that anaplerotically supplies oxaloacetate; 5. The malic enzyme pathway that also links glycolysis and the TCA cycle and generates NADPH to support lipid bio-synthesis; and 6. The acetate bio-synthetic pathway that converts pyruvate directly to acetate. The review discusses the mechanisms controlling these pathways, how they cross-talk and how they cooperate and are regulated to maximize growth and achieve metabolic and energetic harmony.


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