Publications by authors named "Fahiel Casillas"

8 Publications

  • Page 1 of 1

Effects of Porcine Immature Oocyte Vitrification on Actin Microfilament Distribution and Chromatin Integrity During Early Embryo Development .

Front Cell Dev Biol 2021 19;9:636765. Epub 2021 Apr 19.

Department of Biology of Reproduction, Metropolitan Autonomous University-Iztapalapa, Mexico City, Mexico.

Vitrification is mainly used to cryopreserve female gametes. This technique allows maintaining cell viability, functionality, and developmental potential at low temperatures into liquid nitrogen at -196°C. For this, the addition of cryoprotectant agents, which are substances that provide cell protection during cooling and warming, is required. However, they have been reported to be toxic, reducing oocyte viability, maturation, fertilization, and embryo development, possibly by altering cell cytoskeleton structure and chromatin. Previous studies have evaluated the effects of vitrification in the germinal vesicle, metaphase II oocytes, zygotes, and blastocysts, but the knowledge of its impact on their further embryo development is limited. Other studies have evaluated the role of actin microfilaments and chromatin, based on the fertilization and embryo development rates obtained, but not the direct evaluation of these structures in embryos produced from vitrified immature oocytes. Therefore, this study was designed to evaluate how the vitrification of porcine immature oocytes affects early embryo development by the evaluation of actin microfilament distribution and chromatin integrity. Results demonstrate that the damage generated by the vitrification of immature oocytes affects viability, maturation, and the distribution of actin microfilaments and chromatin integrity, observed in early embryos. Therefore, it is suggested that vitrification could affect oocyte repair mechanisms in those structures, being one of the mechanisms that explain the low embryo development rates after vitrification.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcell.2021.636765DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8093386PMC
April 2021

Effect of porcine immature oocyte vitrification on oocyte-cumulus cell gap junctional intercellular communication.

Porcine Health Manag 2020 Nov 25;6(1):37. Epub 2020 Nov 25.

Departamento de Ciencias de la Salud, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, 09340, CDMX, México.

Vitrification may severely affect cumulus cells and oocyte morphology and viability, limiting their maturation and developmental potential. The aim of this study was to evaluate the gap junction intercellular communication (GJIC) integrity after the vitrification of porcine immature cumulus-oocyte complexes (COCs). Fresh COCs were randomly distributed in three groups: untreated (control), toxicity (cryoprotectants exposure), and vitrification, then subjected to in vitro maturation (IVM). Oocyte viability and IVM were measured in all groups. The evaluation of GJIC was expressed as relative fluorescence intensity (RFI). Vitrification significantly decreased oocyte viability and maturation after 44 h of culture compared to control. Also, significantly reduced RFI was observed in vitrified COCs during the first hours of culture (4-8 h) compared to control. This study demonstrates that porcine oocyte viability and maturation after 44 h of culture decreased after vitrification. GJIC was also affected during the first hours of culture after the vitrification of immature oocytes, being one of the possible mechanisms by which oocyte maturation decreased.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40813-020-00175-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7687833PMC
November 2020

Neuroendocrine disruption is associated to infertility in chronically stressed female rats.

Reprod Biol 2020 Dec 15;20(4):474-483. Epub 2020 Aug 15.

Department of Health Sciences, Autonomous Metropolitan University-Iztapalapa, Mexico.

Infertility is a growing worldwide public health problem, and stress is a main factor exerting detrimental effects on female reproduction. However, knowledge regarding the neuroendocrine changes caused by chronic stress in females is limited. Therefore, this study assessed the effects of stress on hormones that control female reproduction during the proestrus and diestrus stages of the estrous cycle, as well as its effects on fertility. Adult females were assigned to either a control or a stress group. Stress consisted of exposure, for 15 min, to cold-water immersion daily for 30 days. Estrous cyclicity, female sexual behavior, as well as hypothalamic kisspeptin, gonadotropin releasing hormone (GnRH) content, serum luteinizing hormone (LH), estradiol (E), progesterone (P), corticosterone (CORT) and fertility were assessed after chronic stress. The results show that chronically stressed females exhibited disrupted estrous cyclicity, decreased receptivity, low pregnancy rates and lower numbers of fetuses. The content of Kisspeptin and GnRH in the Anteroventral Periventricular/medial Preoptic Area decreased during proestrus, while Kisspeptin increased in the Arcuate nucleus in proestrus and diestrus. Serum LH decreased only during proestrus, whereas E and P concentrations decreased during proestrus and diestrus, with a concomitant increase in CORT levels in both stages. As a whole, these results indicate that chronic stress decreases Kisspeptin content in AVPV nucleus and GnRH in POA in females, and might induce disruption of the LH surge, consequently disrupting estrous cyclicity and fertility, leading to lower rates of pregnancy and number of fetuses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.repbio.2020.07.011DOI Listing
December 2020

Effects of methylparaben on in vitro maturation of porcine oocytes.

J Appl Toxicol 2021 Feb 7;41(2):330-337. Epub 2020 Aug 7.

Department of Biology of Reproduction, Metropolitan Autonomous University-Iztapalapa Campus, Mexico City, Mexico.

Parabens (PBs) are compounds widely used in industry for food and personal care products as antimicrobials and preservatives. Their indiscriminate use has resulted in their detection in different ecosystems so that humans and other organisms are highly exposed. Methylparaben (MePB), compared with other PBs, is mostly detected in food, personal care and baby care products. PBs could be linked to the generation of hormonal disorders and fertility impairment since their recent classification as endocrine disruptors. The knowledge of the effects that MePB can exert is of great importance as, in terms of reproduction, information is limited. Therefore, the objective of the present study was to evaluate the effect of MePB on porcine oocyte viability and in vitro maturation (IVM), as well as to determine the lethal concentration at 50% (LC ) and the maturation inhibition concentration at 50% (MIC ). Oocytes were exposed to different MePB concentrations 0 (control), 50, 100, 500, 750 and 1000 μm during 44 h of IVM. Cytoplasmic alterations and reduced cumulus cell expansion were observed in oocytes exposed to MePB; however, viability was not affected. In addition, oocyte maturation decreased in a concentration-dependent manner after exposure to MePB. The estimated LC was 2028.38 μm, whereas MIC was 780.31 μm. To our knowledge, this is the first study that demonstrates that MePB altered porcine oocyte morphology, and caused a reduction in cumulus cell expansion, both of which resulted in decreased oocyte maturation. Therefore, MePB exposure may be one of the factors involved in fertility impairment in mammals, including that of humans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jat.4045DOI Listing
February 2021

An efficiency comparison of different in vitro fertilization methods: IVF, ICSI, and PICSI for embryo development to the blastocyst stage from vitrified porcine immature oocytes.

Porcine Health Manag 2018 13;4:16. Epub 2018 Aug 13.

1Departamento de Biología de la Reproducción, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, 09340 CDMX, Mexico.

Background: Most studies carried out to evaluate recovery and development after porcine oocyte vitrification, reported better rates when cryopreserved in embryonic development stages or zygotes, but not in immature oocytes. For this reason, many studies are performed to improve immature oocyte vitrification protocols testing the use of different cryoprotectant concentrations, cooling devices, incubation times; but only a few of them have evaluated which fertilization procedure enhances blastocyst rates in vitrified oocytes. Therefore, this study was aimed to evaluate: 1) if the sperm selection with hyaluronic acid (HA) or polyvinylpyrrolidone (PVP) before injection could play a key role in increasing fertilization and blastocyst formation and 2) the embryo developmental ability and blastocyst production of porcine immature oocytes retrieved after vitrification-warming and co-cultured with granulosa cells during IVM, using different fertilization techniques: in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and conventional ICSI with hyaluronic acid (HA) sperm selection, known as physiological intracytoplasmic sperm injection (PICSI) and.

Results: Sperm selected with HA-PICSI displayed a higher percentage of live/acrosome reacted status compared to those in control and exposed to PVP. Higher dead/acrosome reacted rates were obtained after PVP exposure compared to control and HA. In oocytes, viability significantly decreased after IVM in vitrified oocytes. Besides, IVM rates were not different between control denuded oocytes cultured with granulosa cells (DO-GC) and vitrified oocytes. Regarding fertilization parameters, IVF showed higher percentages of total fertilization rate than those obtained by ICSI and PICSI. However, results demonstrate that PICSI fertilization increased the blastocysts formation rate in control DO-GC and vitrified oocytes compared to IVF and ICSI.

Conclusions: To achieve high blastocyst formation rates from vitrified GV oocytes, it is recommended that sperm should be selected with HA instead of PVP before injection since high viability and acrosome reaction rates were obtained. Also, PICSI fertilization was the best method to produce higher blastocyst rates compared to the IVF and ICSI procedures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40813-018-0093-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6088397PMC
August 2018

Gradual decrease in spermatogenesis caused by chronic stress.

Acta Histochem 2017 Apr 21;119(3):284-291. Epub 2017 Feb 21.

Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana Iztapalapa, San Rafael Atlixco 186, C.P. 09340, Mexico City, Mexico. Electronic address:

Chronic stress induces decreased sperm motility, viability and concentration in stressed males. Also, stress modifies oxidative status and causes apoptosis in testes, as well as a decrease in the epithelial area of seminiferous tubules. However, there are no studies that analyze the alterations caused by stress in testicular cells. Thus, in this study, alterations in the morphology of testicular germ cells caused by different days of chronic stress were assessed. Adult male rats were exposed to stress by immersion in cold water (ICW) daily for 3, 8, 20 or 50 consecutive days. Plasma testosterone and corticosterone were also assessed. Results showed that chronic stress causes loss of germ cells, and alteration of spermatogenesis. Seminiferous tubules from stressed males showed several degenerative signs, such as vacuoles in the basal epithelium, with picnotic indicia; moderate to severe exfoliation of degenerative germinal cells in the tubule lumen was also observed. These alterations were observed in all days of stress in a gradual way, from day 3-50. Testosterone levels were decreased at all those times, and corticosterone concentrations were increased on the same days. These results show that chronic stress causes severe damage to germ cells, which can account for infertility problems in males. These alterations are related to a decrease in testosterone as well as an increase in corticosterone caused by stress.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.acthis.2017.02.004DOI Listing
April 2017

Porcine embryo production following in vitro fertilization and intracytoplasmic sperm injection from vitrified immature oocytes matured with a granulosa cell co-culture system.

Cryobiology 2015 Oct 5;71(2):299-305. Epub 2015 Aug 5.

Departamento de Ciencias de la Salud, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, 09340 DF, Mexico. Electronic address:

This study was designed to evaluate the capacity of vitrified-warmed porcine immature oocytes to mature and to be fertilized using in vitro fertilization or intracytoplasmic sperm injection, and to determine the subsequent embryo development. Immature oocytes were vitrified using ethylene glycol and dimethylsulphoxide as cryoprotectants and the Cryolock method. After warming oocytes were cultured 44 h for maturation. Oocytes were randomly distributed in three treatment groups and subjected to in vitro fertilization (Experiment 1) or intracytoplasmic sperm injection (Experiment 2) procedures. The results indicate that the embryo development was higher in denuded oocytes co-cultured with granulosa cells (NkO-CC group) fertilized by in vitro fertilization or intracytoplasmic sperm injection compared to cumulus-cell oocyte complexes (COCs group), showing no significant differences with control. Vitrified denuded oocytes matured with a co-culture system NkO-CC group, displayed higher cleavage rate and blastocyst production than vitrified COCs group. Blastocysts were successfully obtained after IVF and ICSI procedures; however, the development to the blastocyst stage was better after IVF. These results show that the vitrification-warming media, the employment of a granulosa cell co-culture system and the Cryolock method during vitrification, increased the nuclear and cytoplasmic maturation of vitrified porcine immature oocytes. Further experiments are required to enhance porcine embryo production after vitrification.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cryobiol.2015.08.003DOI Listing
October 2015

Co-culture with granulosa cells improve the in vitro maturation ability of porcine immature oocytes vitrified with cryolock.

Cryobiology 2014 Oct 23;69(2):299-304. Epub 2014 Aug 23.

Departamento de Ciencias de la Salud, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, 09340 DF, México. Electronic address:

This study was designed to evaluate the efficiency of two oocyte vitrification-warming procedures using two different devices: Superfine Open Pulled Straws (SOPS) and Cryolock, as well as the effect of the co-culture of vitrified immature oocytes with fresh granulosa cells to improve in vitro maturation (IVM). Immature oocytes were vitrified with two procedures: A) Oocytes were exposed to an increasing concentration of ethylene glycol (EG) from 4% to 35% with 0.5 M trehalose. They then, were loaded in SOPS or Cryolock. For warming, oocytes were exposed to decreasing concentrations of trehalose 0.3, 0.2 and 0.1 M for IVM. B) Oocytes were exposed to two mixtures of EG and dimethylsulfoxide (Me2SO), at 7.5% and 16%, both with 0.4 M of sucrose and then loaded in SOPS or Cryolock and stored in liquid nitrogen. For warming, oocytes were exposed to a single concentration of sucrose 0.5M. After warming, viability was determined; and after 44 h of IVM both viability and meiotic stages were evaluated. The results indicate no significant differences between procedures A and B with SOPS in all maturation stages, reaching a maximum maturation rate of 21%. As to Cryolock, significant differences were observed between both procedures, being procedure B, more efficient with a yield of 38% in MII stage and increased to 49% due to the co-culture with fresh granulosa cells. In conclusion, viability and maturation rates were improved with Cryolock and procedure B with the co-culture system in vitrified immature oocytes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cryobiol.2014.08.004DOI Listing
October 2014