Development of a rapid, sensitive, and reproducible laboratory test kit for the assessment of plasma membrane integrity of human sperm

Proteomic analysis of boar sperm with differential ability of liquid preservation at 17 °C

Understanding the liquid preservation ability of boar sperm is pivotal for efficient management and breeding of livestock. Although sperm proteins play an important role in semen quality and freezability, how the levels of protein change in boar sperm with different liquid preservation abilities at 17 °C remains unclear. In this study, two groups of boar sperm with extreme difference in liquid preservation ability, namely the good preservation ability (GPA) and the poor preservation ability (PPA) groups, were selected by evaluating sperm motility parameters on the 7th day of liquid preservation at 17 °C. Quantitative proteomics based on tandem mass tag (TMT) labeling was used, sperm proteomic characteristics from two groups were analyzed, and potentially key proteins related to the fluid preservation ability of sperm were identified. A total of 187 differentially expressed proteins (DEPs) were identified among 2791 quantified proteins, including 85 upregulated, and 102 downregulated proteins. Further, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the DEPs revealed that they were enriched in GO terms associated with response to oxidative stress, enzyme activity related to oxidative stress or redox reactions, and several metabolic activities. The significant KEGG pathways included peroxisome, metabolic pathways, selenocompound metabolism, and collection duct acid secretion. In addition, analysis of protein-protein interactions further identified 8 proteins that could be used as biomarker candidates, including GPX5, GLRX, ENO4, QPCT, BBS7, OXSR1, DHRS4 and AP2S1, which may play an essential role in indicating the liquid preservation ability of boar sperm. These findings in this study provide new insights into the underlying molecular mechanisms of the liquid preservation ability of boar sperm. Moreover, the selected candidate proteins can serve as a reference for evaluating sperm quality or preservation ability in boars and their application in related biotechnologies.

Male contraceptive efficacy of Ricinus communis L. extract

ETHNOPHARMACOLOGICAL RELEVANCE

Ricinus communis L. (Rc), of Euphorbiaceae family is a widespread plant in tropical regions and it is used in traditional medicines as an antifertility agent in India and different parts of the world.

AIM OF THE STUDY

The aim of the present study is to revalidate the ethnobotanical knowledge by evaluating the activity of only crude stem bark extracts of Rc. In this study, effects of extracts on male contraceptive efficacy were experimented in vitro with human sperm sample. The work is based on primordial and contemporary therapeutic uses of this plant.

MATERIALS AND METHODS

In this study, dose of petroleum ether extract, ethyl acetate extract, acetone extract and lyophilised aqueous extract of Rc were added to fresh human semen in 1:1 volumetric ratio. As the aqueous extract showed a promising result in 1:1 ratio, therefore, the Hypo-osmotic swelling test (HOS), Nuclear chromatin decondensation test (NCD) and Acrosomal status and function test (AFT) were also carried out with the aqueous extract of Rc.

RESULTS

The sperm immobilisation effects of the extract appeared immediately in a dose-dependent manner when the samples were treated with four different extracts of this plant. At a concentration of 100mg/mL, 100% (p<0.001 and p<0.05) sperms lost their progressive motility. At a concentration of 300 mg/mL, 100% (p<0.001 and p<0.05) became immotile when treated with aqueous extract. There was 88% (p<0.001 and p<0.05) morphological deformities in sperm sample due the effect of aqueous extract when they were tested for HOS and 91% (p<0.05) sperms behaved against NCD as compared to control group. Also there was a distinct decline (p<0.05) in AFT with increase in dosage concentration.

CONCLUSION

The findings of the study revealed that aqueous stem bark extract of the plant showed dose dependent loss of sperm motility by influencing the morphological deformation, blockage in nuclear envelope and distinct declination in acrosomal status of spermatozoa. This research, thus, opens up scope for future exploration of bark of the plant as commercial source of new male contraceptive.

Spontaneously developed tail swellings (SDTS) influence the accuracy of the hypo-osmotic swelling test (HOS-test) in determining membrane integrity and viability of human spermatozoa

PURPOSE

To investigate the prevalence of spontaneously developed tail swellings (SDTS) in human sperm samples that are commonly encountered in the laboratory, and their influence on the hypo-osmotic swelling test (HOS-test).

METHODS

Ejaculated, epididymal, and testicular sperm were evaluated for SDTS. Further, HOS-test scores were compared with those of vital stains using column washed sperm maintained in the laboratory.

RESULTS

SDTS, at <10%, was present in all types of sperm samples. The highest and lowest occurrences of SDTS were found in cryopreserved sperm, and column-washed sperm respectively. SDTS can inflate the HOS-test score, and so lower the accuracy of the HOS-test. However, the HOS-test efficiency can be improved by assessing SDTS in the sample.

CONCLUSION

HOS-test and vital stain cannot be used interchangeably in all circumstances for sperm viability determination. The accuracy of the HOS-test can be enhanced by incorporating SDTS as a correction factor.

Is abnormal sperm function an indicator among couples with recurrent pregnancy loss?

OBJECTIVE

To determine whether or not sperm function parameters are altered in male partners of couples with a history of idiopathic recurrent pregnancy loss (RPL).

DESIGN

In comparison with proven fertile volunteers, sperm function parameters like hypo-osmotic swelling (HOS), acrosomal status (AS), and nuclear chromatin decondensation (NCD) were assessed in vitro from male partners of couples with a history of idiopathic RPL.

SETTING

Infertility clinic and andrology laboratory at National Institute of Health and Family Welfare.

PATIENT(S)

Male partners of couples with a history of idiopathic RPL and proven fertile male volunteers (control).

INTERVENTION(S)

Standard semen analysis, assessment of sperm morphology, and sperm function with tests such as HOS, AS, and NCD.

MAIN OUTCOME MEASURE(S)

Sperm paameters, such as HOS, AS, and NCD, were assessed in semen samples from RPL in comparison with the proven fertile control group.

RESULT(S)

Semen samples from the idiopathic RPL group showed below normal test scores in 57.1% of the cases for all three sperm parameters. The highest aberration (83% of cases) in sperm attributes was observed in NCD, followed by AS (45.7%) and HOS (42.9%). In contrast, abnormality in sperm morphology was limited to 5.7% of the cases. Subnormal sperm function is directly proportional with subnormal sperm motility (<50%) in 23% of the cases. Even in semen samples with normal sperm motility, sperm function scores were below normal in 31.4% of the RPL group.

CONCLUSION(S)

Reduction in test scores of sperm function, like HOS, AS, and NCD, in male partners of couples with idiopathic RPL suggests that sperms with altered or lowered functional competencies, if they fertilize the oocytes, may lead to the development of an unsustainable embryo resulting in early pregnancy loss. Normal sperm motility does not always ensure normal sperm function scores.