319 VALIDATION OF THE CARBOXYFLUORESCEIN DIACETATE ASSOCIATED WITH PROPIDIUM IODIDE FOR MURINE SPERM ACROSOME AND PLASMA MEMBRANE INTEGRITY

2010 ◽  
Vol 22 (1) ◽  
pp. 315
Author(s):  
F. M. Sevciuc ◽  
C. M. Mendes ◽  
F. R. O. de Barros ◽  
W. B. Feitosa ◽  
R. Simões ◽  
...  

The spermatozoa is an ideal vehicle for genetic modification, production of transgenic animals, as well as a biotechnological tool for sperm-mediated gene transfer. However, in order to achieve successful sperm fertilization and exogenous DNA integration, it is necessary for viable cells to remain intact, allowing the sperm to penetrate the oocyte. Fluorescent probes allow evaluation of morphological and functional characteristics of cells, which can be evaluated separately or simultaneously. Therefore, the aim of this study was to validate the simultaneous evaluation of the integrity of plasma and acrosomal membranes of murine sperm using the probes carboxyfluorescein diacetate (CF) and propidium iodide (PI). In order to validate, a standard curve was performed. Sperm were obtained from epididymis and vas deferens from CD-1 mice (8 to 16 weeks of age). Recovered samples were diluted in PBS and then divided into 2 aliquots: one prepared with fresh semen (FS) and the other submitted to Percoll gradient (45%/90%) followed by flash-freezing in liquid nitrogen and thawing (FTP) to induce acrosome damage. Samples were prepared with the following average of FS:FTP: 100:0 (T100), 50 : 50 (T50), and 0 : 100 (T0). Samples were stained using 2 μL Hoescht 33342 (40 μLmL-1 in Dulbecco’s phosphate buffered saline), 3 μL of PI (0.5 mg mL-1 in PBS), 3 μL of CF (0.46 mg mL-1 in DMSO), and were incubated for 8 min at room temperature. After staining, the samples were placed on a slide, coverslipped, and evaluated immediately by epifluorescent microscopy. The Hoescht, PI, and CF fluorescence was detected using a filter with excitation at 352, 538, and 495 nm and emission at 455, 617, and 517 nm, respectively. Approximately 200 sperm cells per slide were examined and classified based on the fluorescence emitted from each probe. Spermatozoa CF+/IP- were considered as intact membranes, CF+/PI+ as acrosome membrane intact and plasma damaged, CF-/PI+ as damaged membranes, and CF-/PI- as acrosome membrane damaged and plasma intact. Hoeschst was used as positive dye. This experiment was replicated 6 times per group, and for statistical analyses, the data of plasma and acrosomal membrane integrity (dependent variables) in the treatments T0, T50, and T100 (independent variables) were submitted to simple linear regression analysis by STATVIEW software (SAS Institute Inc., Cary, NC, USA). The CFDA/PI probes were suitable for the analysis of acrosomal and membrane status of murine sperm and showed a high determination coefficient to plasma membrane integrity (R2 = 0.81; Y = 0.5412x + 6.375) and acrosome integrity (R2 = 0.85; Y = 0.5653x + 11.653). The described protocol was efficient for the simultaneous evaluation of plasma and acrosomal membrane integrity of murine spermatozoa, proving that CFDA can be employed to access acrosomal integrity as an alternative to FITC-PSA. Financial support: FAPESP.

2016 ◽  
Vol 68 (3) ◽  
pp. 620-628 ◽  
Author(s):  
L.S.L.S. Reis ◽  
A.A. Ramos ◽  
A.S. Camargos ◽  
E. Oba

ABSTRACT This study evaluated the plasma membrane integrity, acrosomal membrane integrity, and mitochondrial membrane potential of Nelore bull sperm from early puberty to early sexual maturity and their associations with sperm motility and vigor, the mass motility of the spermatozoa (wave motion), scrotal circumference, and testosterone. Sixty Nelore bulls aged 18 to 19 months were divided into four lots (n=15 bulls/lot) and evaluated over 280 days. Semen samples, collected every 56 days by electroejaculation, were evaluated soon after collection for motility, vigor and wave motion under an optical microscope. Sperm membrane integrity, acrosomal integrity, and mitochondrial activity were evaluated under a fluorescent microscope using probe association (FITC-PSA, PI, JC-1, H342). The sperm were classified into eight integrity categories depending on whether they exhibited intact or damaged membranes, an intact or damaged acrosomal membrane, and high or low mitochondrial potential. The results show that bulls have a low amount of sperm with intact membranes at puberty, and the sperm show low motility, vigor, and wave motion; however, in bulls at early sexual maturity, the integrity of the sperm membrane increased significantly. The rate of sperm membrane damage was negatively correlated with motility, vigor, wave motion, and testosterone in the bulls, and a positive correlation existed between sperm plasma membrane integrity and scrotal circumference. The integrity of the acrosomal membrane was not influenced by puberty. During puberty and into early sexual maturity, bulls show low sperm mitochondrial potential, but when bulls reached sexual maturity, high membrane integrity with high mitochondrial potential was evident.


2020 ◽  
pp. 1-5
Author(s):  
Ludmila Trilisenko ◽  
Airat Valiakhmetov ◽  
Tatiana Kulakovskaya

Plasma membrane integrity is a key to cell viability. Currently, the main approach to assessing plasma membrane integrity is the detection of penetration of special dyes, such as trypan blue and propidium iodide, into the cells. However, this method needs expensive equipment: a fluorescent microscope or a flow cytometer. Besides, staining with propidium iodide occasionally gives false-positive results. Here, we suggest the phosphate (Pi) leakage assay as an approach to assess the increase in permeability of the plasma membrane of yeast cells. We studied the dependence of phosphate efflux and uptake into Saccharomyces cerevisiae cells on the composition of the incubation medium, time, and ambient pH. The difference in optimal conditions for these processes suggests that Pi efflux is not conducted by the Pi uptake system. The Pi efflux in water correlated with the proportion of cells stained with propidium iodide. This indicated that Pi efflux is associated with cytoplasmic membrane disruption in a portion of the yeast cell population. The assay of Pi efflux was used to evaluate membrane disruption in S. cerevisiae cells treated with some heavy metal ions and detergents.


2020 ◽  
Vol 21 (17) ◽  
pp. 6415
Author(s):  
Filipa Bubenickova ◽  
Pavla Postlerova ◽  
Ondrej Simonik ◽  
Jitka Sirohi ◽  
Jiri Sichtar

Seminal plasma (SP) is the natural environment for spermatozoa and contains a number of components, especially proteins important for successful sperm maturation and fertilization. Nevertheless, in standard frozen stallion insemination doses production, SP is completely removed and is replaced by a semen extender. In the present study, we analyzed the effects of the selected seminal plasma protein groups that might play an important role in reducing the detrimental effects on spermatozoa during the cryopreservation process. SP proteins were separated according to their ability to bind to heparin into heparin-binding (Hep+) and heparin-non-binding (Hep−) fractions. The addition of three concentrations—125, 250, and 500 µg/mL—of each protein fraction was tested. After thawing, the following parameters were assessed: sperm motility (by CASA), plasma membrane integrity (PI staining), and acrosomal membrane integrity (PNA staining) using flow cytometry, and capacitation status (anti-phosphotyrosine antibody) using imaging-based flow cytometry. Our results showed that SP protein fractions had a significant effect on the kinematic parameters of spermatozoa and on a proportion of their subpopulations. The 125 µg/mL of Hep+ protein fraction resulted in increased linearity (LIN) and straightness (STR), moreover, with the highest values of sperm velocities (VAP, VSL), also this group contained the highest proportion of the fast sperm subpopulation. In contrast, the highest percentage of slow subpopulation was in the groups with 500 µg/mL of Hep+ fraction and 250 µg/mL of Hep− fraction. Interestingly, acrosomal membrane integrity was also highest in the groups with Hep+ fraction in concentrations of 125 µg/mL. Our results showed that the addition of protein fractions did not significantly affect the plasma membrane integrity and capacitation status of stallion spermatozoa. Moreover, our results confirmed that the effect of SP proteins on the sperm functionality is concentration-dependent, as has been reported for other species. Our study significantly contributes to the lack of studies dealing with possible use of specific stallion SP fractions in the complex puzzle of the improvement of cryopreservation protocols. It is clear that improvement in this field still needs more outputs from future studies, which should be focused on the effect of individual SP proteins on other sperm functional parameters with further implication on the success of artificial insemination in in vivo conditions.


2014 ◽  
Author(s):  
Mello Papa Patricia de ◽  
Carlos Ramires Neto ◽  
Priscilla Nascimento Guasti ◽  
Rosiara Rosaria Dias Maziero ◽  
Yame F R Sancler-Silva ◽  
...  

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Catarina Dias ◽  
Jesper Nylandsted

AbstractMaintenance of plasma membrane integrity is essential for normal cell viability and function. Thus, robust membrane repair mechanisms have evolved to counteract the eminent threat of a torn plasma membrane. Different repair mechanisms and the bio-physical parameters required for efficient repair are now emerging from different research groups. However, less is known about when these mechanisms come into play. This review focuses on the existence of membrane disruptions and repair mechanisms in both physiological and pathological conditions, and across multiple cell types, albeit to different degrees. Fundamentally, irrespective of the source of membrane disruption, aberrant calcium influx is the common stimulus that activates the membrane repair response. Inadequate repair responses can tip the balance between physiology and pathology, highlighting the significance of plasma membrane integrity. For example, an over-activated repair response can promote cancer invasion, while the inability to efficiently repair membrane can drive neurodegeneration and muscular dystrophies. The interdisciplinary view explored here emphasises the widespread potential of targeting plasma membrane repair mechanisms for therapeutic purposes.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dustin A. Ammendolia ◽  
William M. Bement ◽  
John H. Brumell

AbstractPlasma membrane integrity is essential for cellular homeostasis. In vivo, cells experience plasma membrane damage from a multitude of stressors in the extra- and intra-cellular environment. To avoid lethal consequences, cells are equipped with repair pathways to restore membrane integrity. Here, we assess plasma membrane damage and repair from a whole-body perspective. We highlight the role of tissue-specific stressors in health and disease and examine membrane repair pathways across diverse cell types. Furthermore, we outline the impact of genetic and environmental factors on plasma membrane integrity and how these contribute to disease pathogenesis in different tissues.


Sign in / Sign up

Export Citation Format

Share Document