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1.
Biomedicines ; 11(11)2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-38001873

RESUMO

IZUMO1 is an acrosome transmembrane protein implicated in the adhesion and fusion of gametes. This study aims to describe the distribution of IZUMO1 in human sperm under different physiological conditions: before capacitation (NCS), at one-hour capacitation (CS1), after a hyaluronic acid (HA) selection test (mature, MS1 and immature, IS1), and induced acrosome reaction from one-hour-capacitated sperm (ARS1). The data obtained in NCS, CS1, and MS1 significantly highlight dotted fluorescence in the acrosomal region (P1) as the major staining pattern (~70%). Moreover, we describe a new distribution pattern (P2) with a dotted acrosomal region and a labelled equatorial region that significantly increases in HA-bound spermatozoa, suggesting the onset of the migration of IZUMO1. In contrast, unbound spermatozoa presented an increase in P3 (equatorial region labelled) and P4 (not labelled). Finally, costaining to observe IZUMO1 distribution and acrosome status was performed in ARS1. Interestingly, we reported a variety of combinations between the IZUMO1 staining patterns and the acrosomal stages. In conclusion, these data show as a novelty the diffusion of the IZUMO1 protein during different physiological conditions that could contribute to the improvement in sperm selection techniques.

2.
Reprod Sci ; 30(4): 1176-1185, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35819578

RESUMO

During fertilization, sperm hyaluronidase activity is essential for spermatozoa to successfully penetrate the hyaluronic acid-enriched extracellular matrix of the cumulus cells. Since molecular chaperones, as the heat shock protein A2, are typically involved in bringing hyaluronic acid receptors to the cell surface, here we evaluated the presence and spatial location of HSPA2 on human spermatozoa based on its hyaluronic acid binding capacity. This study included 16 normozoospermic sperm samples from volunteering donors. The location of HSPA2 was studied in cells before and after 1-h incubation under capacitating conditions, as well as in spermatozoa selected according to their ability of binding to hyaluronic acid. Our results showed no significant differences in HSPA2 immunofluorescent cells before and after 1 h of incubation in capacitating conditions. Nevertheless, after hyaluronic acid selection, the percentage of HSPA2-labelled cells increased significantly, indicating that the interaction with hyaluronic acid may induce the unmasking of HSPA2 epitopes. Furthermore, after swim-up and hyaluronic acid selection, spermatozoa presented a highly immunostained equatorial band with a homogeneous fluorescence throughout the acrosomal region. This distribution has been previously suggested to have important implications in male fertility. Noteworthy, a homogeneous fluorescence among the acrosomal region with a more intense labelling at the apical region was observed only in hyaluronic acid bound sperm cells, which may be associated with primary gamete recognition. Our findings suggest that the hyaluronic acid selection technique and HSPA2 biomarker should be considered candidates to complement the classic seminal analysis before recommending an appropriate assisted reproduction technique.


Assuntos
Proteínas de Choque Térmico HSP70 , Ácido Hialurônico , Humanos , Masculino , Ácido Hialurônico/análise , Proteínas de Choque Térmico HSP70/metabolismo , Sêmen/metabolismo , Espermatozoides/metabolismo , Chaperonas Moleculares/análise , Chaperonas Moleculares/metabolismo
3.
Biomedicines ; 10(10)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36289815

RESUMO

The failures of binding to the oocyte zona pellucida are commonly attributed to defects in the sperm recognition, adhesion, and fusion molecules. SPAM1 (sperm adhesion molecule 1) is a hyaluronidase implicated in the dispersion of the cumulus-oocyte matrix. Therefore, the aim of this study was to characterize the SPAM1 distribution in the different physiological conditions of human sperm. Specifically, we evaluated the location of the SPAM1 protein in human sperm before capacitation, at one and four hours of capacitation and after hyaluronic acid (HA) selection test by fluorescence microscopy. Sperm bound to HA were considered mature and those that crossed it immature. Our results detected three SPAM1 fluorescent patterns: label throughout the head (P1), equatorial segment with acrosomal faith label (P2), and postacrosomal label (P3). The data obtained after recovering the mature sperm by the HA selection significantly (p < 0.05) highlighted the P1 in both capacitation times, being 79.74 and 81.48% after one hour and four hours, respectively. Thus, the HA test identified that human sperm require the presence of SPAM1 throughout the sperm head (P1) to properly contact the cumulus-oocyte matrix. Overall, our results provide novel insights into the physiological basis of sperm capacitation and could contribute to the improvement of selection techniques.

4.
Cells Tissues Organs ; 210(1): 1-9, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33873194

RESUMO

Spermatozoa capacitation is a time-dependent physiological process essential for acquiring the fertilizing capacity. In this context, reorganization of spermatozoa surface sugars and tyrosine phosphorylation are some of the most important biochemical changes involved in capacitation. However, the relationship between these 2 biomarkers remains poorly defined. By cytofluorescence we simultaneously characterized the head concanavalin A (ConA)-binding sites and the flagellar tyrosine phosphorylation before capacitation, during different capacitation times (1 and 4 h), and after acrosome reaction induction in human spermatozoa. The results showed a strong connection between ConA-label patterns and tyrosine phosphorylation according to the spermatozoa capacitation time and acrosomal status. Specifically, the spermatozoa subpopulation with phosphotyrosine presented proper sugar location (label in acrosomal and postacrosomal region) just after 1 h of capacitation, while cells without phosphotyrosine needed 4 h to do it. Moreover, after induction of spermatozoa acrosome reaction, phosphorylation was significantly correlated (p < 0.05) with the relocation of ConA-binding residues to the equatorial region, regardless of capacitation time. Overall, these observations provide novel insights regarding spermatozoa subpopulations based on essential physiological events like capacitation and acrosome reaction, which could have potential implications in the improvement of spermatozoa selection techniques.


Assuntos
Reação Acrossômica , Receptores de Concanavalina A , Sítios de Ligação , Humanos , Masculino , Fosforilação , Receptores de Concanavalina A/metabolismo , Espermatozoides/metabolismo , Tirosina/metabolismo
5.
Cells ; 10(2)2021 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-33498624

RESUMO

Capacitation drives sperm biophysical and biochemical changes for sperm-oocyte interactions. It is a well-known fact that the molecular complex arylsulfatase A (ARSA), hyaluronidase sperm adhesion molecule 1 (SPAM1), and heat shock protein 2 (HSPA2) plays a significant role in sperm-zona pellucida (ZP) binding. However, the time-dependent capacitation effects on the sperm surface ARSA presence and specific topographic distributions remain to be elucidated. Here, we quantified the ARSA density and specific membrane domain locations before (US) and after in vitro capacitation (one and four hours; CS1-CS4) in human sperm using high-resolution field emission scanning electron microscopy (FE-SEM) and immunogold labeling. Our results showed a significant and progressive capacitation-mediated increase of labeled spermatozoa from the US (37%) to CS4 (100%) physiological conditions. In addition, surface mapping revealed a close relationship between the ARSA residues and their acrosomal repositioning. Compared with the ARSA surface heterogeneous distribution found in US, the CS1-4 conditions exhibited clustering on the peri-acrosomal region, showing that time-dependent capacitation also induced a ARSA residue dramatic translocation on sperm surfaces. Our findings provide novel insights into the molecular remodeling events preceding sperm-oocyte interactions.


Assuntos
Cerebrosídeo Sulfatase/metabolismo , Microscopia Eletrônica de Varredura , Capacitação Espermática/fisiologia , Ouro/química , Humanos , Masculino , Nanopartículas/ultraestrutura , Cabeça do Espermatozoide/ultraestrutura
6.
Rev Int Androl ; 19(2): 129-136, 2021.
Artigo em Espanhol | MEDLINE | ID: mdl-33342716

RESUMO

OBJECTIVE: To determine the localization and distribution of the ArylsulfataseA receptor (ARSA) in human spermatozoa before and after their incubation in capacitation medium for 1 and 4hours. MATERIAL AND METHODS: Semen samples were obtained from five normozoospermic donors. Capacitation was by swim-up technique using capacitation medium for 1 and 4hours. Localization of the ARSA receptor was assessed by indirect immunofluorescence using confocal microscopy. A minimum of 200cells were observed in each physiological condition. RESULTS: Before incubation, no representative pattern was observed among the cells positive for this biomarker (8.61%). This percentage increased significantly after incubation in the capacitation medium for 1 and 4hours (61.86% and 63.38% respectively). A majority pattern was observed among the capacitated cells, with intense labelling in the acrosomal region (27.11% and 28.20% after 1 and 4hours respectively). It should be noted that the pattern corresponding to fluorescence at the level of the periacrosomal region was not observed in the spermatozoa prior to incubation. Only after incubation in capacitation medium for 1 and 4hours, 9.13% and 12.78% of cells with such distribution were detected. CONCLUSIONS: In vitro capacitation, regardless of time, favours the immunolocalization of ARSA in the cephalic region of the spermatozoa. The most representative subpopulation after this process was the one in which ARSA was intensely and homogeneously distributed in the acrosome region, involved in primary gamete recognition.


Assuntos
Cerebrosídeo Sulfatase/metabolismo , Capacitação Espermática , Espermatozoides/metabolismo , Acrossomo , Proteínas de Transporte , Meios de Cultura , Fertilização , Imunofluorescência , Humanos , Masculino
7.
J Reprod Immunol ; 143: 103246, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33246276

RESUMO

Human fertilization success depends on the ability of the spermatozoa to undergo capacitation. Even though this process can be conducted in vitro, the optimal time for a sperm cell to complete capacitation in vitro is still under discussion due to the lack of proper capacitation biomarkers. Here, we evaluated the influence of in vitro capacitation time on HSPA2 distribution over human sperm head testing this chaperone as a potential capacitation biomarker. The chaperone was assessed in human spermatozoa from 16 normozoospermic donors using indirect immunofluorescence in uncapacitated, one and four-hour capacitated spermatozoa. The percentage of HSPA2 immunofluorescent cells before and after one hour of capacitation did not differ significantly. However, after four hours of capacitation, we observed a significantly higher percentage of HSPA2 labelled cells. In fluorescent cells analysed before capacitation, we could not identify a predominant distribution pattern. Meanwhile, after capacitation, most sperm showed a highly labelled equatorial band accompanied by a homogeneous fluorescence throughout the acrosomal region. Our findings suggest that HSPA2 needs more than one hour of in vitro capacitation for being correctly distributed in the anterior region of the sperm head. In conclusion, the present study provides solid evidences for the utility of HSPA2 as a biomarker of human sperm in vitro capacitation. Due to its importance during egg-sperm recognition, the use of HSPA2 as a biomarker before an artificial reproduction technique may be suggested, in addition to a longer capacitation time during sperm preparation.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Capacitação Espermática/imunologia , Espermatozoides/metabolismo , Biomarcadores/análise , Biomarcadores/metabolismo , Imunofluorescência , Proteínas de Choque Térmico HSP70/análise , Humanos , Masculino , Análise do Sêmen , Espermatozoides/imunologia , Fatores de Tempo
8.
Microsc Microanal ; 26(6): 1220-1225, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33121558

RESUMO

Sperm capacitation includes the reorganization of plasma membrane components and the outstanding modification of the glycocalyx. The α-mannose presence and location during in vitro capacitation have been commonly described in human spermatozoa using Concanavalin A (Con A) lectin. However, it is still unclear to date how in vitro capacitation time affects the α-mannose residues and their topographic spatial distribution on sperm membrane. Here, we characterized the α-mannose density and specific membrane domain locations before and after in vitro capacitation (1­4 h) using high-resolution field emission scanning electron microscopy (FE-SEM). Results showed that α-mannose residues were present preferably on the acrosome domains for all physiological conditions. Uncapacitated sperm comparatively exhibits significant highest labeling densities of α-mannose residues. In addition, as in vitro capacitation takes place, significant and progressive decreasing of sugar residues was combined with their relocation mostly affecting acrosomal domain apical areas. Our findings reveal that combined approach using FE-SEM and gold nanoparticle topographical mapping offers new human sperm biomolecular and structural details during capacitation events.


Assuntos
Cabeça do Espermatozoide , Ouro , Humanos , Masculino , Manose , Nanopartículas Metálicas , Microscopia Eletrônica de Varredura
9.
Cytoskeleton (Hoboken) ; 77(9): 333-341, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32875747

RESUMO

Spermatozoa motility is a key parameter during the fertilization process. In this context, spermatozoa tyrosine protein phosphorylation and an appropriate cytoskeleton α-tubulin distribution are some of the most important physiological events involved in motility. However, the relationship between these two biomarkers remains poorly defined. Here, we characterized simultaneously by immunocytochemistry the α-tubulin (TUBA4A) distribution and the tyrosine phosphorylation at flagellum before capacitation, during different capacitation times (1 and 4 hr), and after acrosome reaction induction in human spermatozoa. We found that the absence of spermatozoa phosphorylation in tyrosine residues positively and significantly correlated (p < 0.05) with the terminal piece α-tubulin flagellar distribution in all physiological conditions. Conversely, we observed a positive significant correlation (p < 0.01) between phosphorylated spermatozoa and continuous α-tubulin distribution in spermatozoa flagellum, independently of the physiological condition. Similarly, the subpopulation of spermatozoa with tyrosine phosphorylated and continuous α-tubulin increases with longer capacitation times and after the acrosome reaction induction. Overall, these findings provide novel insights into the post-transcriptional physiological events associated to α-tubulin and the tyrosine phosphorylation during fertilization, which present potential implications for the improvement of spermatozoa selection methods.


Assuntos
Reação Acrossômica/fisiologia , Citoesqueleto/metabolismo , Espermatozoides/fisiologia , Tubulina (Proteína)/metabolismo , Tirosina/metabolismo , Humanos , Masculino , Fosforilação
10.
Anim Reprod ; 17(1): e20190083, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32405328

RESUMO

Spermatozoa interactions with the female reproductive tract and oocyte are regulated by surface molecules such as glycocalyx. The capacitation process comprises molecular and structural modifications which increase zona pellucida binding affinity. Lectins allowed us to describe glycocalyx changes during maturation, capacitation and acrosome reaction. This study had as its aim to identify lectin binding patterns using four lectins with different carbohydrate affinity in bottlenose dolphin (Tursiops truncatus) spermatozoa both before and after in vitro capacitation. Two semen samples from the same dolphin obtained on consecutive days were used, with four different lectin binding patterns becoming visible in both samples before and after capacitation. A highly stained equatorial segment with prolongations at the edges appeared as the most frequent pattern with Wheat germ agglutinin (WGA) in uncapacitated spermatozoa. However, it was homogeneously distributed over the acrosomal region after capacitation. Instead, the use of Peanut agglutinin (PNA) resulted in most spermatozoa showing high labelling in the acrosomal periphery region before capacitation and a homogeneous staining in the acrosomal region within the population of capacitated spermatozoa. Nevertheless, the most representative patterns with Concavalin A (ConA) and Aleuria aurantia agglutinin (AAA) lectins did not change before and after capacitation, labelling the acrosomal region periphery. These findings could contribute to the understanding of the reproductive biology of cetaceans and the improvement of sperm selection techniques.

11.
Antioxidants (Basel) ; 9(1)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963256

RESUMO

Catalase (CAT) stands out as one of the most efficient natural enzymes when catalysing the split of H2O2 into H2O and O2; H2O2 is one of the reactive oxygen species (ROS) involved in oxidative stress, a process closely related to aging and several health disorders or diseases like male infertility. Some studies have correlated H2O2 with male infertility and catalase with fertility restoration. However, the number of studies conducted with human beings remains scarce. Considering the use of CAT as a molecular target for biochemical analysis, this review summarises the current knowledge on how CAT influences human beings' male fertility. Thus, three different databases were consulted-Scopus, PubMed and WOS-using single keywords and combinations thereof. A total of 40,823 articles were identified. Adopting inclusion and exclusion criteria, a final database of 197 articles served to conduct this work. It follows from this analysis that CAT could play an important role in male fertility and could become a good target for male infertility diagnosis and monitoring. However, that potential role of CAT as a tool in diagnosis must be confirmed by clinical trials. Finally, guidelines are suggested to reinforce the use of CAT in daily clinical tests for male fertility diagnosis and monitoring.

12.
Asian J Androl ; 22(5): 447-453, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31621655

RESUMO

A cascade of dramatic physiological events is linked to the sperm acrosome reaction and binding to the oocyte's zona pellucida during human sperm capacitation. However, structural and functional sperm changes during capacitation currently remain poorly defined. Here, we performed a multibiomarker approach based on the utilization of sperm concentration, motility, viability, morphology, acrosome reaction, tyrosine phosphorylation, DNA fragmentation, and lectin-binding sites to analyze the impact caused by swim-up selection times (uncapacitated, 1 h capacitated, and 4 h capacitated) on sperm function and structure in normozoospermic samples. We found that a 4 h swim-up capacitation increased sperm quality, because a large number of cells with normal morphology and lower DNA fragmentation rates were recovered. Furthermore, the long-term capacitation induced a higher percentage of cells with tyrosine phosphorylation of the principal piece as well as a redistribution of lectin-binding sites. Overall, the multivariate biomarkers analyzed showed a less variable distribution on spermatozoa recovered after 4 h capacitation than that with the shorter capacitation time. These findings stress the importance of capacitation time as a relevant factor in sperm quality with potential biological reproductive implications both for basic research and in assisted reproduction techniques.


Assuntos
Lectinas/metabolismo , Capacitação Espermática , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Espermatozoides/citologia , Espermatozoides/fisiologia , Reação Acrossômica , Biomarcadores , Fragmentação do DNA , Humanos , Técnicas In Vitro , Masculino , Fosforilação , Receptores de Superfície Celular/metabolismo , Fatores de Tempo , Tirosina/metabolismo
13.
Codas ; 32(1): e20190010, 2020.
Artigo em Espanhol, Inglês | MEDLINE | ID: mdl-31859819

RESUMO

PURPOSE: Describe the attitudes towards ageing of senior undergraduate Speech-language Pathology students in a Chilean University. METHODS: This is a cross-sectional study in which the validated Spanish version of the Kogan's Attitudes Toward Old People Scale (KAOP) was applied to 43 students in the aforementioned course. The average scores were compared for the variables gender and interaction with the elderly. RESULTS: A trend towards a positive attitude was observed. No differences were found for the variables described. An analysis was carried out with the items in which trends towards negative attitude were reported, and the implications were discussed. CONCLUSION: Although a positive attitude was reported, aspects of student academic training should be more comprehensively studied with a view to improving the quality of assistance provided to the elderly.


OBJETIVO: Describir las actitudes hacia el envejecimiento por parte de los estudiantes de último año de estudios pertenecientes a la Carrera de Fonoaudiología de una Universidad Chilena. MÉTODO: Se llevó a cabo un estudio de Corte Transversal, mediante el cual se aplicó la validación al español de la Escala de Actitudes Hacia el Envejecimiento de Kogan (KAOP) a 43 estudiantes de esta carrera. Se compararon los promedios de puntuación según variable género, y aquellas relacionadas a la interacción con adultos mayores. RESULTADOS: Hubo una tendencia hacia la actitud positiva. No se encontraron diferencias según las variables mencionadas. Se llevó a cabo un análisis de aquellos ítems donde se reportaron tendencias hacia actitud negativa, discutiendo sus implicancias. CONCLUSIÓN: Si bien hubo reporte de actitud positiva, resulta necesario continuar profundizando en aspectos de la formación académica de los estudiantes, con miras a mejorar la calidad de la atención de los adultos mayores.


Assuntos
Envelhecimento , Atitude do Pessoal de Saúde , Conhecimentos, Atitudes e Prática em Saúde , Relação entre Gerações , Estudantes , Adulto , Idoso , Chile , Estudos Transversais , Feminino , Humanos , Masculino , Fatores Socioeconômicos , Patologia da Fala e Linguagem , Inquéritos e Questionários , Universidades , Adulto Jovem
14.
CoDAS ; 32(1): e20190010, 2020. tab
Artigo em Espanhol | LILACS | ID: biblio-1055891

RESUMO

RESUMEN Objetivo Describir las actitudes hacia el envejecimiento por parte de los estudiantes de último año de estudios pertenecientes a la Carrera de Fonoaudiología de una Universidad Chilena. Método Se llevó a cabo un estudio de Corte Transversal, mediante el cual se aplicó la validación al español de la Escala de Actitudes Hacia el Envejecimiento de Kogan (KAOP) a 43 estudiantes de esta carrera. Se compararon los promedios de puntuación según variable género, y aquellas relacionadas a la interacción con adultos mayores. Resultados Hubo una tendencia hacia la actitud positiva. No se encontraron diferencias según las variables mencionadas. Se llevó a cabo un análisis de aquellos ítems donde se reportaron tendencias hacia actitud negativa, discutiendo sus implicancias. Conclusión Si bien hubo reporte de actitud positiva, resulta necesario continuar profundizando en aspectos de la formación académica de los estudiantes, con miras a mejorar la calidad de la atención de los adultos mayores.


ABSTRACT Purpose Describe the attitudes towards ageing of senior undergraduate Speech-language Pathology students in a Chilean University. Methods This is a cross-sectional study in which the validated Spanish version of the Kogan's Attitudes Toward Old People Scale (KAOP) was applied to 43 students in the aforementioned course. The average scores were compared for the variables gender and interaction with the elderly. Results A trend towards a positive attitude was observed. No differences were found for the variables described. An analysis was carried out with the items in which trends towards negative attitude were reported, and the implications were discussed. Conclusion Although a positive attitude was reported, aspects of student academic training should be more comprehensively studied with a view to improving the quality of assistance provided to the elderly.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Adulto Jovem , Estudantes , Envelhecimento , Atitude do Pessoal de Saúde , Conhecimentos, Atitudes e Prática em Saúde , Relação entre Gerações , Fatores Socioeconômicos , Universidades , Chile , Estudos Transversais , Inquéritos e Questionários , Patologia da Fala e Linguagem
15.
Rev Int Androl ; 16(1): 20-27, 2018.
Artigo em Espanhol | MEDLINE | ID: mdl-30063019

RESUMO

OBJECTIVE: Assess changes in sialic acid distribution during capacitation and acrosome reaction processes, and evaluate head sperm morphometrics modifications in these physiological conditions in human sperm. MATERIAL AND METHOD: In this prospective study, we included 6 normozoospermics sperm samples. Sialic acid distribution was evaluated by Wheat germ agglutinin lectin in different physiological conditions: before, after capacitation and after acrosome reaction. Head shape and size of each stage were analyzed by means of geometric morphometric methods. RESULTS: After capacitation, 73.07±21.43% of sperm showed sialic acid in acrosomal region, linked with an acrosome expansion and equatorial segment contraction. Otherwise, after acrosome reaction higher allometric effect between stages was recorded since sperm undergo further expansion of equatorial segment. Regarding Wheat germ agglutinin location, we found that sperm percentage significant decline in acrosomal fluorescence and an increase of equatorial band labeling. CONCLUSIONS: Our findings demonstrate that modifications in Wheat germ agglutinin expression covariate with dramatic changes in sperm head morphometry, suggesting important implications in capacitation and acrosome reaction processes.


Assuntos
Reação Acrossômica/fisiologia , Ácido N-Acetilneuramínico/metabolismo , Capacitação Espermática/fisiologia , Espermatozoides/fisiologia , Humanos , Masculino , Estudos Prospectivos , Cabeça do Espermatozoide/fisiologia , Aglutininas do Germe de Trigo/metabolismo
16.
Rev. int. androl. (Internet) ; 16(1): 20-27, ene.-mar. 2018. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-170576

RESUMO

Objetivo. Evaluar los cambios de distribución del ácido siálico durante el proceso de capacitación y reacción acrosómica in vitro y estudiar las modificaciones morfométricas en estas condiciones fisiológicas en la región cefálica del espermatozoide humano. Material y método. En este estudio prospectivo, evaluamos 6 muestras espermáticas normozoospérmicas. La distribución de ácido siálico se evaluó mediante la lectina Wheat germ agglutinin en diferentes condiciones fisiológicas: antes, después de la capacitación y tras la reacción acrosómica. La forma y el tamaño cefálico de cada estadio se estudiaron mediante métodos de morfometría geométrica. Resultados. Tras la capacitación, un 73,07±21,43% de espermatozoides presentaron ácido siálico en la región acrosomal en relación directa con una expansión del acrosoma y una contracción del segmento ecuatorial. Por otra parte, después de la reacción acrosómica se registra un mayor efecto alométrico entre los estadios debido a que los espermatozoides experimentaron una marcada expansión del segmento ecuatorial. En relación con la localización de Wheat germ agglutinin, encontramos una disminución significativa en el porcentaje de espermatozoides con fluorescencia en la región acrosomal, así como un incremento del marcaje en la banda ecuatorial. Conclusiones. Nuestros resultados demuestran que la distribución de la lectina Wheat germ agglutinin covaría con importantes cambios en la morfometría de la cabeza del espermatozoide y evidencia importantes implicaciones en los procesos de capacitación y reacción acrosómica (AU)


Objective. Assess changes in sialic acid distribution during capacitation and acrosome reaction processes, and evaluate head sperm morphometrics modifications in these physiological conditions in human sperm. Material and method. In this prospective study, we included 6 normozoospermics sperm samples. Sialic acid distribution was evaluated by Wheat germ agglutinin lectin in different physiological conditions: before, after capacitation and after acrosome reaction. Head shape and size of each stage were analyzed by means of geometric morphometric methods. Results. After capacitation, 73.07±21.43% of sperm showed sialic acid in acrosomal region, linked with an acrosome expansion and equatorial segment contraction. Otherwise, after acrosome reaction higher allometric effect between stages was recorded since sperm undergo further expansion of equatorial segment. Regarding Wheat germ agglutinin location, we found that sperm percentage significant decline in acrosomal fluorescence and an increase of equatorial band labeling. Conclusions. Our findings demonstrate that modifications in Wheat germ agglutinin expression covariate with dramatic changes in sperm head morphometry, suggesting important implications in capacitation and acrosome reaction processes (AU)


Assuntos
Humanos , Masculino , Capacitação Espermática/fisiologia , Cabeça do Espermatozoide/ultraestrutura , Reação Acrossômica/fisiologia , Ácidos Siálicos/análise , Estudos Prospectivos , Aglutininas do Germe de Trigo/análise , Lectinas/análise , Fosforilação/fisiologia , Tirosina/fisiologia
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