Semen levels of spermatid-specific thioredoxin-3 correlate with pregnancy rates in ART couples

Spermatid specific thioredoxin-3 (SPTRX3 or TXNDC8) is a testis/male germ line specific member of thioredoxin family that accumulates in the superfluous cytoplasm of defective human spermatozoa. We hypothesized that semen levels of SPTRX3 are reflective of treatment outcome in assisted reproductive therapy (ART) couples treated by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Relationship between SPTRX3 and treatment outcome was investigated in 239 couples undergoing ART at an infertility clinic. Sperm content of SPTRX3 was evaluated by flow cytometry and epifluorescence microscopy, and correlated with clinical semen analysis parameters, and data on embryo development and pregnancy establishment. High SPTRX3 levels (>15% SPTRX3-positive spermatozoa) were found in 51% of male infertility patients (n¿=¿72), in 20% of men from couples with unexplained, idiopathic infertility (n¿=¿61) and in 14% of men from couples previously diagnosed with female-only infertility (n¿=¿85). Couples with high SPTRX3 produced fewer two-pronuclear zygotes and had a reduced pregnancy rate (19.2% pregnant with >15% SPTRX3-positive spermatozoa vs. 41.2% pregnant with 15% of SPTRX3-positive spermatozoa, a cutoff value established by ROC analysis, had their chance of fathering children by IVF or ICSI reduced by nearly two-thirds. The percentage of SPTRX3-positive spermatozoa had predictive value for pregnancy after ART. Gradient purification and sperm swim-up failed to remove all SPTRX3-positive spermatozoa from semen prepared for ART. In summary, the elevated semen content of SPTRX3 in men from ART couples coincided with reduced incidence of pregnancy by IVF or ICSI, identifying SPTRX3 as a candidate biomarker reflective of ART outcomeThis study was funded by grant number 1R21HD066333-01A1 from the National Institutes of Health, NICHD, grant number CB000414 from the Research Board of the University of Missouri, seed funding from the Food for The 21st Century Program of the University of Missouri and Undergraduate Summer Research Internship, College of Agriculture, Food and Natural Resources (CAFNR), University of Missouri.Peer Reviewe

Cellular events during fertilization in humans

Para dilucidar distintos aspectos del proceso de fecundación y desarrollo temprano, en la presente tesis se analizaron oocitos humanos ‘no fecundados' y ‘fecundados anormalmente' luego de Fecundación In Vitro (FIV) e Inyección Intracitoplásmica de Espermatozoides (ICSI), haciendo hincapié en la arquitectura del citoesqueleto, estado de la cromatina, organización del áster y presencia de activaciones abortivas. Se estudiaron un total de 815 oocitos clasificados como ‘no fecundados’ y 153 oocitos clasificados como ‘fecundados anormalmente' luego FIV e ICSI. El material se procesó para inmunofluorescencia mediante la utilización de anticuerpos monoclonales para la detección de B tubulinas y a tubulinas acetiladas. El material genético se estudió con Hoechst 33258 y se analizó por microscopía óptica (UV). El análisis citogenético se realizó en 189 oocitos activados luego de FIV e ICSI según la técnica de Tarkowski (1966). Durante las fallas de fecundación, la principal causa luego de FIV, fue la ausencia de penetración espermática (59,2%), el 10,5% mostró una falla de activación oocitaria y el 15,2% presentó alteraciones en la nucleación o migración de pronúcleos. Luego de ICSI, la principal causa de falla de fecundación fue la alteración de la activación oocitaria (36,5%). Un 18,5% de los oocitos detuvieron su desarrollo en la primera placa metafásica. El estudio cromosómico, permitió identificar la presencia de activaciones abortivas; metafases III (MIII), núcleos reticulares (NR) y núcleos telofásicos (NT). En la fecundación anormal, el patrón más frecuentemente detectado luego de FIV fue la presencia de 3 ó 4 pronúcleos (PNs), (77,4%). Por el contrario, luego de ICSI resultó ser la presencia de 1PN (65,2%). Se observaron leves diferencias en el desarrollo de subnúcleos entre ambos grupos

Semen levels of spermatid-specific thioredoxin-3 correlate with pregnancy rates in ART couples.

Spermatid specific thioredoxin-3 (SPTRX3 or TXNDC8) is a testis/male germ line specific member of thioredoxin family that accumulates in the superfluous cytoplasm of defective human spermatozoa. We hypothesized that semen levels of SPTRX3 are reflective of treatment outcome in assisted reproductive therapy (ART) couples treated by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Relationship between SPTRX3 and treatment outcome was investigated in 239 couples undergoing ART at an infertility clinic. Sperm content of SPTRX3 was evaluated by flow cytometry and epifluorescence microscopy, and correlated with clinical semen analysis parameters, and data on embryo development and pregnancy establishment. High SPTRX3 levels (>15% SPTRX3-positive spermatozoa) were found in 51% of male infertility patients (n = 72), in 20% of men from couples with unexplained, idiopathic infertility (n = 61) and in 14% of men from couples previously diagnosed with female-only infertility (n = 85). Couples with high SPTRX3 produced fewer two-pronuclear zygotes and had a reduced pregnancy rate (19.2% pregnant with >15% SPTRX3-positive spermatozoa vs. 41.2% pregnant with <5% SPTRX3-positive sperm; one-sided p<0.05). The average pregnancy rate of all 239 couples was 25.1%. Live birth rate was 19.2% and lowest average SPTRX3 levels were found in couples that delivered twins. Men with >15% of SPTRX3-positive spermatozoa, a cutoff value established by ROC analysis, had their chance of fathering children by IVF or ICSI reduced by nearly two-thirds. The percentage of SPTRX3-positive spermatozoa had predictive value for pregnancy after ART. Gradient purification and sperm swim-up failed to remove all SPTRX3-positive spermatozoa from semen prepared for ART. In summary, the elevated semen content of SPTRX3 in men from ART couples coincided with reduced incidence of pregnancy by IVF or ICSI, identifying SPTRX3 as a candidate biomarker reflective of ART outcome

Spermatocyte/Spermatid-specific Thioredoxin-3, a Novel Golgi Apparatus-associated Thioredoxin, Is a Specific Marker of Aberrant Spermatogenesis

38 páginas, 10 figuras. Tiene una figura y una tabla suplementaria.Mammalian germ cells are endowed with a complete set of thioredoxins (Trx), a class of redox proteins located in specific structures of the spermatid and sperm tail. We report here the characterization, under normal and pathological conditions, of a novel thioredoxin with a germ line-restricted expression pattern, named spermatocyte/spermatid-specific thioredoxin-3 (SPTRX-3). The human SPTRX-3 gene maps at 9q32, only 50 kb downstream from the TRX-1 gene from which it probably originated as genomic duplication. Therefore, human SPTRX-3 protein comprises a unique thioredoxin domain displaying high homology with the ubiquitously expressed TRX-1. Among the tissues investigated, Sptrx-3 mRNA is found exclusively in the male germ cells at pachytene spermatocyte and round spermatid stages. Light and electron microscopy show SPTRX-3 protein to be predominately located in the Golgi apparatus of pachytene spermatocytes and round and elongated spermatids, with a transient localization in the developing acrosome of round spermatids. In addition, increased levels of SPTRX-3, possibly caused by overexpression, are observed in morphologically abnormal human spermatozoa from infertile men. In addition, SPTRX-3 is identified as a novel postobstruction autoantigen. In this report, we propose that SPTRX-3 can be used as a specific marker for diverse sperm and testis pathologies. SPTRX-3 is the first thioredoxin specific to the Golgi apparatus, and its function within this organelle might be related to the post-translational modification of proteins required for germ cell-specific functions, such as acrosomal biogenesis.This work was supported by the Swedish Medical Research Council Projects 03P-14096, 03X-14041, and 13X-10370 and grants from the Åke Wibergs Stiftelse and the Karolinska Institutet (to A. M.-V.). A. J. was supported by a postdoctoral fellowship (EX2003-0390) from the Spanish Ministerio de Educacion, Cultura y Deporte. M. P-H was supported by the Medical Research Fund of Tampere University Hospital. P.S. was supported by the Food for the 21st Century Program of the University of Missouri-Columbia, and by USDA/NRI (grant #2002-02069). C.F. was supported by grants from NIH/NIDDK (P50 DK45179) and NIH/NICHD (HD U54-29009). R.O. was supported by Canadian grants from NSERC and CIHR.Peer reviewe