Affiner votre recherche
Résultats 1-10 de 17
Effect of extender supplementation with low-molecular-weight antioxidants on selected quality parameters of cryopreserved canine spermatozoa
2018
Lecewicz, Marek | Strzeżek, Rafał | Kordan, Władysław | Majewska, Anna
Introduction The addition of low-molecular-weight antioxidants during the freezing process improves post-thaw sperm quality. The high antioxidant potential of cryopreserved semen could have a positive effect on the motility, viability, and energy status of sperm cells and their ability to bind to the zona pellucida of oocytes. The aim of the study was to determine the effects of different concentrations and combinations of vitamins E and C in a semen extender on selected quality parameters of frozen-thawed canine spermatozoa. Material and Methods The experimental material was the semen of four mixed-breed dogs. Sperm viability (motility, plasma membrane integrity, and mitochondrial function) was examined at 0, 60, and 120 min in semen samples supplemented with the extender and in the controls. Results Combined supplementation with vitamins C + E at a concentration of 200 + 200 μM /1 × 10⁹ spermatozoa had the most profound effect on total sperm motility, linear motility, and the percentage of spermatozoa with intact plasma membrane and active mitochondria. Conclusion The synergistic activity of vitamins E and C had a more beneficial influence on the quality of frozen–thawed sperm than these non-enzymatic antioxidants applied separately.
Afficher plus [+] Moins [-]Estrogen-related receptor α (ERRα) functions in the hypoxic injury of microglial cells
2022
Deng, Chao-Yang | Zhu, Ting-Ting | Lian, Shuai | Wang, Jian-Fa | Wu, Rui | Zheng, Jia-San
Hypoxia is a common pathological condition after spinal cord injury. Oestrogen-related receptor alpha (ERRα), as a key regulator of energy metabolism and mitochondrial functions, plays an important role in maintaining cell homeostasis. However, its role in hypoxic spinal microglia has not been fully elaborated. This study investigated the receptor’s activity when these cells are hypoxic and used as an in vitro model. In this study, microglia (BV2) were exposed to cobalt chloride as a hypoxic model, and the inverse agonist of ERRα, XCT790, and pyrido[1,2-α]-pyrimidin-4-one were used to regulate the expression of the receptor to explore the ERRα-related mechanisms involved in hypoxic spinal cord injury (SCI). ERRα promoted autophagy in BV2 cells and inhibited the activation of the p38 mitogen-activated protein kinase (MAPK) pathway and the expression of anti-inflammatory factors under hypoxic conditions. It also promoted the expression of fibronectin type III domain containing protein 5 (FNDC5). When a hypoxic SCI occurs, ERRα may maintain the homeostasis of spinal cord nerve cells by regulating autophagy and the p38MAPK/nuclear factor-kappa B cell and FNDC5/brain-derived neurotrophic factor signalling pathways, which are beneficial to the recovery of these cells.
Afficher plus [+] Moins [-]Screening of early diagnostic markers of gentamicin-induced acute kidney injury in canines
2019
Zheng, Jia-San | Jing-Nie, | Zhu, Ting-Ting | Ruan, Hong-Ri | Xue, Wei | Rui-Wu,
The value of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (Kim-1), and liver-type fatty acid binding protein (L-FABP) was assessed in early diagnosis of gentamicin-induced acute kidney injury (AKI) in dogs. Subcutaneous gentamicin injection in 16 healthy adult beagles made the AKI model. Blood was sampled every 6 h to detect NGAL, Kim-1, L-FABP, and serum creatinine (SCr) concentrations. Kidney tissue of two dogs was taken before the injection, as soon as SCr was elevated (78 μmol/L), and when it had risen to 1.5 times the baseline, and haematoxylin-eosin staining and transmission electron microscopy (TEM) were used to observe changes. NGAL, Kim-1, and SCr levels were significantly increased (P < 0.05) at 18, 30, and 78 h post injection, but L-FABP concentration was not associated with renal injury. At the earliest SCr elevation stage, findings were mild oedema, degeneration, and vacuolisation in renal tubular epithelial cells in pathology, and mild cytoplasmic and mitochondrial oedema in TEM. At this time point, NGAL and Kim-1 concentrations were significantly increased (P < 0.05), indicating that these two molecules biomark early kidney injury in dogs. Using receiver operating characteristic curve analysis, their warning levels were > 25.31 ng/mL and > 48.52 pg/mL. Plasma NGAL and Kim-1 above warning levels are early indicators of gentamicin-induced AKI in dogs.
Afficher plus [+] Moins [-]Influence of inosine pranobex on cell viability in normal fibroblasts and liver cancer cells
2018
Tobólska, Sylwia | Terpiłowska, Sylwia | Jaroszewski, Jerzy | Siwicki, Andrzej Krzysztof
Inosine pranobex (Isoprinosine) stimulates cell-mediated immune responses to viral infections in humans and might have also therapeutic use in animals. The aim of this study was to compare three in vitro cytotoxicity assays on mouse embryo fibroblasts and liver cancer cells and determine their ability to detect early cytotoxic effects for inosine pranobex. BALB/3T3 clone A31and HepG2 cells were incubated with inosine pranobex at concentrations from 0.1 to 1,000 μg/mL. Cell viability was determined with the MTT reduction, the LHD release, and the NRU tests. A decrease in the cell viability was observed after incubating the BALB/3T3 clone A31and HepG2 cells with inosine pranobex. Based on the cytotoxicity endpoints measured in these investigations in BALB/3T3 clone A31cells, it can be concluded that the cell membrane may be the first part of the cell to be affected by inosine pranobex. The disintegration of lysosomes and mitochondria follows mitochondria damage. In HepG2 cells likewise, the cell membrane may be the first part of the cell to be affected by inosine pranobex. Also in liver cancer cells, the disintegration of mitochondria (assessed with the MTT reduction assay) and next of lysosomes (assessed with the NRU assay) follows mitochondria damage.
Afficher plus [+] Moins [-]Molecular study of Cysticercus tenuicollis from slaughtered sheep in Sulaymaniyah province, Iraq
2020
Mohammed, Aram Ahmad
Cysticercosis caused by the larval stage of Taenia hydatigena is economically the most important endemic parasitic disease in Iraq. Few data are available relating to the genetic divergence of this helminth. This study aimed to molecularly characterise Cysticercus tenuicollis isolates from sheep in Sulaymaniyah province, Iraq. DNA extraction and amplification of specimens of C. tenuicollis from 46 sheep were conducted by PCR for the mitochondrial 12S rRNA gene. The 19 amplicons were subjected to purification and partial sequencing. Five 12S rRNA nucleotide sequence haplotypes were found. The pairwise nucleotide difference between haplotypes of 12S rRNA gene ranged from 0.2% to 0.7%. Four out of the five haplotypes of C. tenuicollis contained one to two base mutations and were discovered in Iraq for the first time, and this may be a unique mutation globally which has not been recorded previously. Three newly recorded haplotypes contained only one single mutation, and the other one contained two mutations. Phylogenetic analysis showed that all isolated strains were closely related to Iranian sheep isolates. Four new strains of T. hydatigena were discovered for the first time in the study area.
Afficher plus [+] Moins [-]Mitochondrial theory of skeletal muscle ageing –new facts, new doubts
2019
Słodki, Sebastian | Bogucka, Joanna
For many years, scientists have been pursuing research on skeletal muscle ageing both in humans and animals. Studies on animal models have extended our knowledge of this mechanism in humans. Most researchers agree that the major processes of muscle ageing occur in the mitochondria as the major energy production centres in muscle cells. It is believed that decisive changes occur at the enzymatic activity level as well as in protein synthesis and turnover ability. Deregulation of ion channels and oxidative stress also play significant roles. In particular, in recent years the free radical theory of ageing has undergone considerable modification; researchers are increasingly highlighting the partly positive effects of free radicals on processes occurring in cells. In addition, the influence of diet and physical activity on the rate of muscle cell ageing is widely debated as well as the possibility of delaying it through appropriate physical exercise and diet programmes. Numerous studies, especially those related to genetic processes, are still being conducted, and in the near future the findings could provide valuable information on muscle ageing. The results of ongoing research could answer the perennial question of whether and how we can influence the rate of ageing both in animals and humans.
Afficher plus [+] Moins [-]Cell viability in normal fibroblasts and liver cancer cells after treatment with iron (III), nickel (II), and their mixture
2018
Terpiłowska, Sylwia | Siwicka-Gieroba, Dorota | Siwicki, Andrzej Krzysztof
Introduction: Nickel and iron are very commonly occurring metals. Nickel is used in industry, but nowadays it is also used in medical biomaterials. Iron is an element necessary for cell metabolism and is used in diet supplements and biomaterials, whence it may be released along with nickel. Material and Methods: BALB/3T3 and HepG2 cells were incubated with iron chloride or nickel chloride at concentrations ranging from 100 to 1,400 µM. The following mixtures were used: iron chloride 200 µM plus nickel chloride 1,000 µM, or iron chloride 1,000 µM plus nickel chloride 200 µM. The cell viability was determined with MTT, LHD, and NRU tests. Results: A decrease in cell viability was observed after incubating the BALB/3T3 and HepG2 cells with iron chloride or nickel chloride. A synergistic effect was observed after iron chloride 1,000 μM plus nickel chloride 200 μM treatment in all assays. Moreover, the same effect was observed in the pair iron chloride 200 μM plus nickel chloride 1,000 μM in the LDH and NRU assays. Conclusions: Iron (III) and nickel (II) decrease cell viability. Iron chloride at a concentration of 200 µM protects mitochondria from nickel chloride toxicity.
Afficher plus [+] Moins [-]Characterization of canine mitochondrial protein expression in natural and induced forms of idiopathic dilated cardiomyopathy
2006
Lopes, R. | Solter, P.F. | Sisson, D.D. | Oyama, M.A. | Prosek, R.
Objective-To map canine mitochondrial proteins and identify qualitative and quantitative differences in heart mitochondrial protein expression between healthy dogs and dogs with naturally occurring and induced dilated cardiomyopathy (DCM). Sample Population-Left ventricle samples were obtained from 7 healthy dogs, 7 Doberman Pinschers with naturally occurring DCM, and 7 dogs with induced DCM. Procedures-Fresh and frozen mitochondrial fractions were isolated from the left ventricular free wall and analyzed by 2-dimensional electrophoresis. Protein spots that increased or decreased in density by greater than or equal to 2-fold between groups were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or quadrupole selecting, quadrupole collision cell, time-of-flight mass spectrometry. Results-Within narrow pH gradients of control canine heart mitochondrial samples, a total of 1,528 protein spots were revealed. Forty subunits of heart mitochondrial proteins that differ significantly from control tissues were altered in tissue specimens from dogs with naturally occurring and induced forms of DCM. The most affected heart mitochondrial proteins in both groups were those of oxidative phosphorylation (55%). Upregulation of manganese superoxide dismutase was suggestive of heart oxidative injury in tissue specimens from dogs with both forms of DCM. Evidence of apoptosis was associated with overexpression of the heart mitochondrial voltage-dependent anion channel-2 protein and endonuclease G in tissue specimens from dogs with induced DCM. Conclusions and Clinical Relevance-Alterations of heart mitochondrial proteins related to oxidative phosphorylation dysfunction were more prevalent in tissue specimens from dogs with induced or naturally occurring DCM, compared with those of control dogs.
Afficher plus [+] Moins [-]Carprofen-induced oxidative stress in mitochondria of the colonic mucosa of the dog
2014
Snow, Lynne A. | McConnico, Rebecca S. | Morgan, Timothy W. | Hartmann, Erica | Davidson, Jacqueline R. | Hosgood, Giselle
The purpose of the study was to compare the conductance and mannitol permeability of canine colonic mucosa in response to carprofen or 2,4-dinitrophenol (DNP) with or without tempol pretreatment. Ten colonic mucosa sections per dog were mounted in Ussing chambers. Treatments were done in duplicate. Mucosa was exposed to carprofen (200 μg/mL) or DNP (0.25 mM), both with and without tempol (1 mM) pretreatment. Conductance was calculated every 15 min for 240 min. Mannitol flux was calculated over 3 consecutive 60-minute periods. Histology or electron microscopy was done after exposure. Conductance over time, mannitol flux, frequency of histologic categories, and electron microscopic changes were analyzed for treatment effects. The mean ± standard deviation (SD) conductance over time for carprofen or DNP-treated colons was not significantly different from control regardless of tempol pretreatment. Period 3 mannitol fluxes for carprofen and DNP-treated colon were not significantly different, but were greater than control. Period 3 mannitol flux for tempol + carprofen was significantly less than tempol + DNP-treated colon. Sloughing of cells and erosions were seen in the mucosa of carprofen-treated colon. Mitochondrial damage was seen more often in carprofen-treated than DNP-treated or control colon. Tempol pretreatment resulted in more ruptured mitochondria in the carprofen-treated colon; however, other mitochondrial changes were not significantly affected by tempol pretreatment in either carprofen or DNP treated colon. Treatment with carprofen or DNP increased the mannitol flux, but pretreatment with tempol mitigated the carprofen effect. It is apparent that structural mitochondrial damage occurs in the canine colonic mucosa after carprofen and DNP exposure.
Afficher plus [+] Moins [-]Mitochondrial dysfunction in myocardium obtained from clinically normal dogs, clinically normal anesthetized dogs, and dogs with dilated cardiomyopathy
2012
Sleeper, Meg M. | Rosato, Bradley P. | Bansal, Seema | Avadhani, Narayan G.
Objective: To compare mitochondrial complex I and complex IV activity in myocardial mitochondria of clinically normal dogs, clinically normal dogs exposed to inhalation anesthesia, and dogs affected with dilated cardiomyopathy. Sample: Myocardial samples obtained from 21 euthanized dogs (6 clinically normal [control] dogs, 5 clinically normal dogs subjected to inhalation anesthesia with isoflurane prior to euthanasia, 5 dogs with juvenile-onset dilated cardiomyopathy, and 5 dogs with adult-onset dilated cardiomyopathy). Procedures: Activity of mitochondrial complex I and complex IV was assayed spectrophotometrically in isolated mitochondria from left ventricular tissue obtained from the 4 groups of dogs. Results: Activity of complex I and complex IV was significantly decreased in anesthetized dogs, compared with activities in the control dogs and dogs with juvenile-onset or adult-onset dilated cardiomyopathy. Conclusions and Clinical Relevance: Inhalation anesthesia disrupted the electron transport chain in the dogs, which potentially led to an outburst of reactive oxygen species that caused mitochondrial dysfunction. Inhalation anesthesia depressed mitochondrial function in dogs, similar to results reported in other species. This effect is important to consider when anesthetizing animals with myocardial disease and suggested that antioxidant treatments may be beneficial in some animals. Additionally, this effect should be considered when designing studies in which mitochondrial enzyme activity will be measured. Additional studies that include a larger number of animals are warranted.
Afficher plus [+] Moins [-]