| 1. |
- Caballero, Ignacio, et al.
(författare)
-
Immunolocalization and possible functional role of PSP-I/PSP-II heterodimer in highly extended boar spermatozoa
- 2006
-
Ingår i: Journal of Andrology. - : American Society of Andrology. - 0196-3635 .- 1939-4640. ; 27:6, s. 766-773
-
Tidskriftsartikel (refereegranskat)abstract
- PSP-I/PSP-II heterodimer is a major protein of boar seminal plasma which is able to preserve, in vitro, the viability, motility, and mitochondrial activity of highly extended boar spermatozoa for at least 5 hours. However, little is known about the binding pattern of the heterodimer to the sperm plasma membrane and its eventual relation with the maintenance of the sperm functionality. The present study investigated the effect of exposing highly extended boar spermatozoa (11 million/mL) to 1.5 mg/mL of PSP-I/PSP-II for 0.5, 5, and 10 hours at 38 degrees C on sperm characteristics and the changes in PSP-I/PSP-II localization as a result of both the addition of PSP-I/PSP-II to the extender and the incubation time. Exposure of the spermatozoa to PSP-I/PSP-II preserved sperm viability, motility, and mitochondrial activity when compared to nonexposed spermatozoa. This protective effect lasted for 10 hours (P less than.05). After immunolabeling of highly extended semen with rabbit monospecific polyclonal antibody against PSP-I/PSP-11, the percentage of immunopositive spermatozoa declines over time from 71% (0.5 hours) to 49% (10 hours). However, more than 80% of spermatozoa remained labeled during the 10-hour incubation period if PSP-I/PSP-11 was added. Scanning electron microscopy revealed 4 different binding patterns. The heterodimer was mainly localized to the acrosomal area, being redistributed to the postacrosomal area or lost during in vitro incubation. In conclusion, the protective effect of the heterodimer appears to be related to its adhesion to the acrosomal area, and the loss of this protective effect coincides with a stepwise redistribution of PSP-I/PSP-II during incubation.
|
|
| 2. |
- Cremades, T, et al.
(författare)
-
Kinematic changes during the cryopreservation of boar spermatozoa
- 2005
-
Ingår i: Journal of Andrology. - : American Society of Andrology. - 0196-3635 .- 1939-4640. ; 26:5, s. 610-618
-
Tidskriftsartikel (refereegranskat)abstract
- The present study evaluates the effect that various steps of a conventional cycle of cryopreservation have on the patterns of movement exhibited by boar spermatozoa. Sperm-rich ejaculate fractions collected from 24 mature fertile boars (1 ejaculate per boar) were cryopreserved following a standard freeze-thaw procedure with 0.5-mL plastic straws. Overall sperm motility and the individual kinematic parameters of motile spermatozoa (assessed by the computer-aided sperm analysis system Sperm Class Analyzer [SCA]) were recorded in 5 steps of the cryopreservation procedure. These steps were as follows: 1) at the time that the fresh semen was extended, 2) at 17 degrees C, after sperm concentration by centrifugation and re-extension of the pellet with lactose-egg yolk extender; 3) at 5 degrees C, after added freezing extender; 4) at the time that thawed semen was held in a water bath at 37 degrees C for 30 minutes; and 5) at the time that thawed semen was held in a water bath at 37 degrees C for 150 minutes. Data from individual motile spermatozoa, defined by 7 kinematic parameters (curvilinear velocity [VCL], straight-line velocity [VSL], average path velocity [VAP], linearity [LIN], straightness [STR], mean amplitude of lateral head displacement [ALH], and beat cross frequency [BCF]), were analyzed using a pattern analysis technique (PATN) to identify and quantify populations and subpopulations of motile sperm within the semen samples. After the first cluster analysis, 3 motile sperm populations (P) were identified (P1: progressive and/or vigorous cells [90.4%], P2: poorly progressive cells [8.3%], and P3: nonprogressive cells [1.3%]). These populations remained constant (P greater than .05) throughout the 5-step cryopreservation procedure. A second PATN was carried out within the P1 sperm population, which identified 3 sperm subpopulations (sP) (eg, sP1: cells with progressive and vigorous movement [58.7%], sP2: progressive cells only [24.6%], and sP3: vigorous cells only, hyperactive-like [16.7%]). Although the relative frequency of these 3 subpopulations varied among ejaculates (boars), there was no interaction with any cryopreservation step we examined. Whereas sP1 remained constant (P greater than .05), sP2 and sP3 varied significantly (P less than .05) through the cryopreservation procedure, with the increase in sP3 after centrifugation at 17 degrees C and during cooling at 5 degrees C considered particularly relevant. In conclusion, the present study confirms the heterogeneity of sperm movement patterns in boar semen, patterns that vary through the cryopreservation procedure, especially after removal of the seminal plasma by centrifugation and subsequent extension at 17 degrees C and after the slow cooling at 5 degrees C, when obvious increases in hyperactivated movement appeared. The vast majority of spermatozoa, those exhibiting progressive and vigorous movement, remained constant during the cryopreservation procedure, although the proportion differed among boars.
|
|
| 3. |
- Ek, Pia, et al.
(författare)
-
Exogenous protein kinases A and C, but not endogenous prostasome-associated protein kinase, phosphorylate semenogelins I and II from human semen
- 2002
-
Ingår i: Journal of Andrology. - 0196-3635 .- 1939-4640. ; 23:6, s. 806-814
-
Tidskriftsartikel (refereegranskat)abstract
- Semenogelins I and II are the quantitatively dominating proteinsin humansemen. They comprise the major part of the sperm-entrappinggel formed atejaculation, which subsequently liquefies dueto proteolysis of thegel-forming proteins by prostate-specificantigen (PSA). The mechanism behindgel formation and its physiologicalsignificance is not known. We have studiedphosphorylation anddephosphorylation of human semenogelins. Both werephosphorylatedby protein kinases A and C (PKA and PKC, respectively) at arateabout 5 times less than that of histone. For PKA, incorporated(32P)phosphateinto semenogelin approached a maximum above 1mol/mol. Correspondingvalues for phosphorylation of the semenogelins with PKCweregreater than 10. There was no change in the sensitivity ofphosphosemenogelinsto proteolysis by PSA. Serine (PKA) and serine andthreonine(PKC) were the phosphate-accepting amino acid residues, andallincorporated (32P)phosphate could be removed from the semenogelinswithhuman acid phosphatase. Nil or very little phosphate could bedetected inpurified semenogelins isolated from seminal plasma.In vivo, about half theprotein kinase activity in seminal plasmawas bound to prostasomes. PKA butnot PKC purified from prostasomescould phosphorylate specific substrates, butthey could phosphorylateeither of the semenogelins.
|
|
| 4. |
- Macías García, Beatriz, et al.
(författare)
-
The mitochondria of stallion spermatozoa are more sensitive than the plasmalemma to osmotic induced stress: role of c-Jun N-terminal Kinase (JNKs) pathway
- 2012
-
Ingår i: Journal of Andrology. - Schaumburg, IL, United States : American Society of Andrology. - 0196-3635 .- 1939-4640. ; 33:1, s. 105-113
-
Tidskriftsartikel (refereegranskat)abstract
- Cryopreservation introduces extreme temperature and osmolality changes that impart lethal and sublethal effects on spermatozoa. Additionally, there is evidence that the osmotic stress induced by cryopreservation causes oxidative stress to spermatozoa. The main sources of reactive oxygen species in mammalian sperm are the mitochondria. In view of this, the aim of our study was to test whether or not osmotic stress was able to induce mitochondrial damage and to explore the osmotic tolerance of the mitochondria of stallion spermatozoa. Ejaculates from 7 stallions were subjected to osmolalities ranging from 75 to 1500 mOsm/kg, and the effect on sperm membrane integrity and mitochondrial membrane potential was studied. Additionally, the effects of changes in osmolality from hyposmotic to isosmotic and from hyperosmotic to isosmotic solutions were studied (osmotic excursions). The cellular volume of stallion spermatozoa under isosmotic conditions was 20.4 ± 0.33 μm3. When exposed to low osmolality, the stallion spermatozoa behaved like a linear osmometer, whereas exposure to high osmolalities up to 900 mOsm/kg resulted in decreased sperm volume. Although sperm membranes were relatively resistant to changes in osmolality, mitochondrial membrane potential decreased when osmolalities were low or very high (10.7 ± 1.74 and 16.5 ± 1.70 at 75 and 150 mOsm/kg, respectively, and 13.1 ± 1.83 at 1500 mOsm/kg), whereas in isosmolar controls the percentage of stallion sperm mitochondria with a high membrane potential was 41.1 ± 1.69 (P < .01). Osmotic excursions induced greater damage than exposure of spermatozoa to a given nonphysiologic osmolality, and again the mitochondria were more prone to damage induced by osmotic excursions than was the sperm plasma membrane. In search of intracellular components that could mediate these changes, we have detected for the first time the c-Jun N-terminal kinase 1/2 in stallion spermatozoa, which are apparently involved in the regulation of the viability of these cells.
|
|
| 5. |
- Pena, FJ, et al.
(författare)
-
Identification of sperm morphometric subpopulations in two different portions of the boar ejaculate and its relation to postthaw quality
- 2005
-
Ingår i: Journal of Andrology. - : American Society of Andrology. - 0196-3635 .- 1939-4640. ; 26:6, s. 716-723
-
Tidskriftsartikel (refereegranskat)abstract
- A statistical approach using sequentially principal component analysis (PCA), clustering, and discriminant analyses was. developed to identify sperm morphometric subpopulations in well-defined portions of the fresh boar ejaculate. Semen was obtained as 2 portions (the first 10 mL of the sperm-rich fraction and the rest of. the ejaculate, respectively) and frozen using a conventional protocol. Before freezing, an aliquot was Used for computer-assisted. sperm morphometry analysis (ASMA). Postthaw quality was evaluated using computer-assisted sperm analysis (CASA), and an annexin-V/PI assay evaluated sperm membranes. The PCA revealed that 3 variables represented more than 78% of the cumulative variance in sperm subpopulations. The clustering and discriminant analyses, based on 5780 individual spermatozoa, revealed the existence of 4 sperm subpopulations. The relative percentage of these subpopulations Varied between boar and ejaculate portions. Linear regression models based on measured morphometric characteristics could account for up to 36% of the percentage of intact sperm membranes postthaw. The ASMA protocol used in our study was useful to detect subtle morphometric differences between spermatozoa, and the combination of this analysis with a multivariate statistical procedure gave hew information on the biological characteristics of boar ejaculates that is not given by conventional sperm analysis.
|
|
| 6. |
- Sipilä, Petra, et al.
(författare)
-
Regional expression of androgen receptor coregulators and androgen action in the mouse epididymis.
- 2011
-
Ingår i: Journal of andrology. - : Wiley. - 1939-4640 .- 0196-3635. ; 32:6, s. 711-7
-
Tidskriftsartikel (refereegranskat)abstract
- Endocrine regulation of the mouse initial segment (IS) and distal caput epididymides was studied using genome-wide profiling of gene expression. Among the IS-enriched genes, 29% were significantly down-regulated 1 day after gonadectomy. Of those genes, dihydrotestosterone (DHT) supplementation was not sufficient to maintain their pregonadectomy level of expression in 70%. Of the caput-enriched genes, 16% were significantly down-regulated after gonadectomy, and of those genes, DHT supplementation did not maintain the initial level of expression in 28%. Identical data were obtained by clustering analyses performed for the expression data of epididymal genes. Furthermore, the microarray data revealed that 26 androgen receptor coregulators were expressed in the epididymis, of which several were confirmed by quantitative reverse transcriptase polymerase chain reaction analysis. This suggests putative involvement of these proteins in the segment-specific regulation of the epididymal genes. The pattern of epididymal gene expression in the novel proximal epididymis-specific androgen receptor knockout mouse ProxE-ARKO, with severe hypotrophy and hypoplasia of the caput epithelium, furthermore suggested that a subset of genes whose expression cannot be maintained by systemic androgen alone still require either direct lumicrine androgen action or a permissive effect of circulating testosterone. It is evident that testicular factors, one of which could be the high-concentration luminal androgen, are important for the expression of IS-enriched genes, whereas the expression of distal caput-enriched genes is typically regulated by systemic androgens.
|
|
| 7. |
|
|
| 8. |
- AHLGREN, GÖRAN, et al.
(författare)
-
Impaired Secretory Function of the Prostate in Men With Oligo‐Asthenozoospermia
- 1995
-
Ingår i: Journal of Andrology. - 0196-3635. ; 16:6, s. 491-498
-
Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: The secretory function of the human prostate and the seminal vesicles is a prerequisite for gel formation and liquefaction of semen, but the relation to poor sperm motility and low sperm count in infertile men remains to be clarifyed. Our aim was to evaluate the secretory function of the prostate and the seminal vesicles in normozoospermic men (n=35) and in asthenozoospermic men, who were all also oligozoospermic (n=27). All 62 subjects belonged to couples undergoing routine infertility evaluation. In liquefied seminal fluid we measured the concentrations of fructose and protein C inhibitor (PCI) contributed by the seminal vesicles, PCI complexed to prostate‐specific antigen (PSA), and the prostatic contribution of zinc, PSA, acid phosphatase (PAP), β‐microseminoprotein (β‐MSP), and Znα2‐glycoprotein (Znα2‐GP). The concentration of each prostatic secretory protein correlated significantly with that of zinc (P < 0.01) in both the normozoospermic (NZS) and oligo‐astheno‐zoospermic (OAZS) subgroups, but the PCI concentration did not correlate significantly with that of fructose. There was no significant difference between the NZS and OAZS subgroups in ejaculate volume or secretory contribution from the seminal vesicles, whereas the OAZS subgroup was characterized by significantly lower secretory contributions of Znα2‐GP (P = 0.001), Zn, PSA, PAP (P < 0.01), and β‐MSP (P < 0.05). The two subgroups did not differ significantly in the serum concentration of luteinizing hormone (LH), testosterone, or sex hormone‐binding globulin (SHBG). The results thus suggest the secretory contribution of major prostatic proteins and zinc per ejaculate to be significantly decreased in oligo‐asthenozoospermic men. The importance of this finding in relation to poor sperm count and motility as indicators of impaired gonadal function requires further investigation. 1995 American Society of Andrology
|
|
| 9. |
|
|
| 10. |
- Bjartell, Anders, et al.
(författare)
-
Distribution and tissue expression of semenogelin I and II in man as demonstrated by in situ hybridization and immunocytochemistry
- 1996
-
Ingår i: Journal of Andrology. - 0196-3635. ; 17, s. 17-26
-
Tidskriftsartikel (refereegranskat)abstract
- Semenogelin I and II (Sgl, Sgll) are two separate gene products of chromosome 20 with extensive (80%) identity in primary structure. They are mainly responsible for immediate gel formation of freshly ejaculated semen. Degradation of Sgl and Sgll is due to the proteolytic action of prostate-specific antigen (PSA); it results within 5-15 minutes in liquefaction of semen and release of progressively motile spermatozoa. By means of cDNA cloning and Northern blots, Sgl and Sgll transcripts have previously been shown to be abundant in human seminal vesicles, but Sgll alone is suggested to be expressed at low levels in the epididymis. To characterize the expression and tissue distribution of Sgl and Sgll in greater detail, we produced monoclonal immunoglobulin Gs (lgGs for immunocytochemistry (lCC) and specific [35S]-, digoxigenin-, or alkaline phosphatase-labeled 30-mer antisense probes to Sgl and Sgll for in situ hybridization (lSH). Immunocytochemical staining for both Sgl and Sgll, and lSH detection of both Sgl and Sgll transcripts, were demonstrated in the cytoplasm of seminal vesicle epithelium. lSH showed Sgll alone to be expressed in the epithelium of the epididymal cauda. Neither lCC nor lSH yielded any evidence of Sgl or Sgll expression in caput or corpus epithelium or in any stromal cells of the epididymis. Consistent with our previous findings using polyclonal lgG, monoclonal anti-Sgll Sgll lgGs identified epitopes on the posterior head, midpiece, and tail of ejaculated spermatozoa. Spermatozoa in the epididymal cauda were also immunoreactive, but those in the caput or corpus region of the epididymis as well as those in the testis were negative. As shown by lCC, neither Sgl nor Sgll were expressed in the testis, the prostate, the female genital tract, or other normal human tissue specimens. Although the significance of Sg attachment to epididymal and ejaculated spermatozoa remains to be established, monoclonal anti-Sg lgG might prove useful in establishing the origin of seminal vesicle tissue components in prostate core biopsies or other biopsy specimens.
|
|
