Equine seminal plasma and sperm membrane: Functional proteomic assessment

During ejaculation, a large amount of seminal plasma proteins interact with the sperm membrane, leading to a series of biochemical and structural changes implicated in sperm function and gamete interaction. However, the roles of the majority of these proteins remain unknown. This study aimed to investigate the proteome and functionality of the major equine proteins of seminal plasma and the sperm membrane. Seminal plasma and enriched-membrane proteins (150 μg) were separated by two-dimensional gel electrophoresis, and the respective maps were analyzed. Protein identification was performed by in-gel digestion and tandem mass spectrometry (GeLC-MS/MS). Samples were also submitted to in-solution digestion (complex protein mixture) and identified by shotgun analysis by LC-MS/MS; bioinformatic tools were used to investigate protein functions. Seminal plasma and sperm membrane extract maps contained 91.0 ± 8.2 spots and 245.3 ± 11.3 spots, respectively, within the 3-10 pH range. In total, the most abundant proteins identified in 2D maps and in complex protein mixtures included 24 proteins for seminal plasma and 33 for sperm membrane extract, with a high degree of confidence (P < 0.05). Of these, HSP1, CRISP3 and KLK1E2 were the most abundant in seminal plasma; HSP1 was highly abundant in sperm membrane extract, in many isoforms, which is related to membrane destabilization and may compromise sperm preservation. HSP1-polybromo-1 interactions suggested a role in DNA stabilization. Prosaposin was identified in seminal plasma and may play a role in the fertilization process. IZUMO4, a member of the IgSF family involved in the prefertilization stages, was identified in 2D gel and MS/MS analysis of sperm membrane extract. Ten proteins of seminal plasma were found to interact with the sperm membrane and were related to binding and catalytic activities (clusterin, CRISP3, epididymal sperm-binding protein 1, kallikrein1E2, seminal plasma protein A3, and HSP1). Additionally, other identified proteins were associated with DNA integrity, capacitation and recognition of pregnancy. These findings indicate that the binding of specific proteins to the plasma membrane during ejaculation may influence sperm survival after cryopreservation and may play a role in decreasing the quality in stallions with toxic seminal plasma. Elucidation of these interactions is an important step in understanding the biological processes related to equine fertility and facilitates future investigations on the selection and application of low freezability semen strategies.

313 ASSESSMENT OF LUTEAL FUNCTION IN TOGGENBURG GOATS BY COMPUTER-ASSISTED IMAGE ANALYSIS

Computer-assisted image analysis is a technological extension of reproductive ultrasonography and allows the quantitative assessment of the luteal echotexture, which is related to changes in histological features and, consequently, to steroidogenesis. The aim of this study was to determine the efficiency of luteal echotexture evaluation as a tool to assess luteal function in different phases of the estrous cycle in Toggenburg goats. Nulliparous goats (n = 21), 8 months in age, 33.52 ± 1.22 kg of body weight, and body score condition of 3.5 ± 0.07 (1 to 5 scale), which showed estrus within a 48-h period during the natural breeding season (March and April), were used. After estrous detection (Day 0) and mating, ovarian sonographic evaluations were performed daily using a portable ultrasound device (Aloka SSD 500, Aloka Co.) equipped with an adapted linear transrectal 5-MHz probe. The examinations were preceded by blood sample collections, which were stored until radioimmunoassay for progesterone (P4). Images were recorded in VHS tapes, then digitized to TIFF files (resolution of 1500 × 1125 pixels) using a video capture board. A representative elementary area of 5625 pixels (0.31 cm2) was defined for the luteal tissue according to the criterion proposed by Van den Bygaart and Protz 1999. Computer-assisted analyses were performed using custom-developed software (Quantporo®). Each pixel received a numeric value ranging from 0 (black) to 255 (white). Luteal echotexture and plasma P4 data were analyzed by ANOVA, and differences among means were determined by Tukey’s test. Correlations were established by Pearson’s correlation method. Results are shown as mean ± SEM. Corpora lutea size increased progressively (P < 0.001) until Day 9, when it reached the maximum area (1.26 ± 0.32 cm2). No increase in size was detected on the subsequent days (P > 0.05). Plasma P4 levels increased until a maximum value on Day 9 (6.31 ± 0.46 ng mL–1), and no increase was observed further (P > 0.05). In nonpregnant animals (n = 7), luteolysis was characterized by an abrupt decrease in plasma P4 concentration, which dropped to values lower than 1 ng mL–1 24 h after the onset of the process, whereas luteal area decreased gradually. Plasma P4 concentration was correlated to luteal area during luteogenesis and luteolysis (r = 0.63 and r = 0.50, respectively; P < 0.05). Mean pixel value showed a progressive increase during luteogenesis and reached the maximum value on Day 13 (54.33 ± 1.83). During corpus luteum (CL) regression, mean pixel value decreased to lower values 48 h after the onset of natural luteolysis (P < 0.05). Through both luteogenesis and luteolysis, positive correlations were observed between mean pixel values and luteal area (r = 0.34 and r = 0.26, respectively; P < 0.05) and also between mean pixel values and plasma P4 concentration (r = 0.24 and r = 0.37, respectively; P < 0.05). Pixel heterogeneity was not correlated to luteal area nor plasma P4 levels. These results suggest an association between CL echotexture and steroidogenic function; therefore, the quantitative assessment of the pixel brightness has a potential to be used for luteal function evaluation in goats. FAPEMIG and CAPES.

312 LUTEAL MORPHOMETRIC PARAMETERS AND SONOGRAPHIC ECHOTEXTURE DURING LUTEOGENESIS PERIOD IN PREGNANT GOATS

Sonographic echotexture is an important parameter for corpora lutea (CL) evaluation, since it is related to variations on vascularization and histological features of CL and, consequently, to steroidogenesis. The aim of this study was to evaluate the luteal dynamics and pixel value during the early luteogenic period in goats. Nuliparous Toggenburg females (n = 18) with an average age of 8 months, weight of 33.52 � 5.58 kg, and body condition score of 3.5 � 0.33 (1 to 5 scale) were used. Ovarian sonographic evaluations were performed daily for 21 days after natural estrus, using a portable ultrasound device (Aloka SSD 500, Aloka Co., Ltd., Tokyo, Japan) equipped with an adapted linear rectal 5-MHz probe. CL and cavity areas were measured at their largest diameter. CL area minus the cavity area was considered luteal tissue. Images were digitalized in .TIFF format, at a 1500 � 1125 resolution, using a video capture board (Pinnacle DC10, Pinnacle Systems, Mountain View, CA, USA). Images recovered on Days 6, 8, 10, and 12 of the estrous cycle were analyzed using a custom software (Quantpro�). Each image dot (pixel) received a numeric value ranging from 0 (black) to 255 (white). Representative elementary area (REA) of 5625 pixels (0.31 cm2) was defined in the luteal tissue (proposed by Van den Bygaarty et al. 1999 Can. J. Soil Sci. 7, 149–160). Due to the possibility of early luteal regression, only data from pregnant animals (14/18, 77.8%) were used. Follicle diameter, CL area, and cavity were analyzed by ANOVA, and differences among means were evaluated by Tukey's test. Correlations were established by Pearson's correlation method. Results are presented as means � SEM. Mean diameter of ovulatory follicle was 0.75 � 0.01 cm. There was no significant correlation (P > 0.05) between ovulatory follicle diameter and CL area. CL were first visualized on Day 5.68 � 0.37 after the estrus, with a mean area of 0.56 � 0.05 cm2, and progressively increased in size (P < 0.001) until Day 12, reaching a maximum area of 1.18 � 0.06 cm2. A significant (P < 0.05) pixel value increase was observed from Days 6 to 12 of the cycle (42.79 � 5.06a; 47.90 � 4.51ab; 48.33 � 4.21b; and 52.95 � 4.65b, respectively, values with the same superscript not being significantly different). There was a significant positive correlation (R = 0.54, P < 0.0001) between luteal tissue area and pixel value during the luteogenesis period. In single ovulating goats (10/14; 71.42%), the mean time for the first CL visualization was lower (4.71 � 0.15 v. 6.78 � 0.89 days; P < 0.01) and the area of the CL on Day 12 was larger (1.32 � 0.04 v. 1.03 � 0.15 cm2; P < 0.01) than in goats with two or more ovulations, but there was no difference in luteal pixel value (52.32 � 3.19 v. 53.75 � 3.90; P > 0.05). The presence of luteal cavities was observed in 89.47% (17/19) of the CLs on the first day of visualization, with a mean size of 0.30 � 0.05 cm2, representing 45.31% of the total CL area and difficult echotexture analysis. These cavities progressively regressed (P < 0.01) until Day 11 of the cycle, with an area less than 0.1 cm2. These results show that pixel values are correlated to CL development in goats, suggesting an association between CL echotexture and steroidogenic function.

Specification of training sets and the number of hidden neurons for multilayer perceptrons

This work concerns the selection of input-output pairs for improved training of multilayer perceptrons, in the context of approximation of univariate real functions. A criterion for the choice of the number of neurons in the hidden layer is also provided. The main idea is based on the fact that Chebyshev polynomials can provide approximations to bounded functions up to a prescribed tolerance, and, in turn, a polynomial of a certain order can be fitted with a three-layer perceptron with a prescribed number of hidden neurons. The results are applied to a sensor identification example.

IL-2 and IFN-gamma, but not IL-4 secretion by peripheral blood mononuclear cells (PBMC) are related to CD4+ T cells and clinical status in Brazilian HIV-1-infected subjects

It has been reported that production of IL-2 and IFN-gamma, known as T-helper type 1 cytokines, by peripheral mononuclear cells (PBMC) decreases with progression of HIV infection. In contrast, IL-4 and IL-10 production, Th2 cytokine profile, increases with HIV disease progression. PBMC were evaluated from 55 HIV-infected subjects from Divisão de Imunologia, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, to "in vitro" cytokines production after 24 hours of stimulation with PHA. Low levels of IL-4 production in both HIV-infected patients and normal subjects, were detected. The patients with CD4+ T cell counts < 200 showed a significant decrease of IL-2 and IFN-gamma production compared to controls. Patients with higher counts of CD4+ T cells (either between 200-500 or > 500 cells/mm3) also showed decreased production of IL-2 that was not statistically significant. There was a correlation between IL-2 and IFN-gamma release with CD4+ T cells counts. HIV-1-infected individuals with CD4+ T cells > 500 cells/mm3 showed increased levels of IL-2 and IFN-gamma, than individuals with CD4+ T cells < 500 cells/mm3. In conclusion, we observed a decline of IL-2 and IFN-gamma production at advanced HIV disease. IL-4 production was not affected during HIV infection. Taken together, these findings suggest that the cytokine profile might be influenced by the HIV infection rather than the cause of disease progression.