What happens to the unsuccessful spermatozoa?

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Phosphopeptide Analysis of Rodent Epididymal Spermatozoa
09:30

Phosphopeptide Analysis of Rodent Epididymal Spermatozoa

Published on: December 30, 2014

13.5K

K M Engel1,2, C H Springsguth1, S Grunewald1

  • 1Andrological Unit, Dermatology, Venerology and Allergology Clinic, University Hospital Leipzig, Leipzig, Germany.

Andrology
|February 14, 2018
PubMed

Insights

High intracellular calcium levels may trigger apoptosis in human sperm, leading to acrosome reactions and decreased motility. Reducing calcium levels with a chelator inhibited these apoptotic features.

Area of Science:

  • Human reproductive biology
  • Spermatozoa physiology
  • Cellular apoptosis

Background:

  • Apoptosis, or programmed cell death, is a critical process in cellular function.
  • The acrosome reaction is essential for sperm fertilization.
  • The role of apoptosis in mature spermatozoa and its correlation with the acrosome reaction remain areas of investigation.

Purpose of the Study:

  • To investigate apoptosis as a functional pathway in mature human spermatozoa.
  • To determine the correlation between apoptosis and the acrosome reaction.
  • To elucidate the role of intracellular calcium concentration in these processes.

Main Methods:

  • Semen samples from 27 healthy human donors were analyzed.
  • Sperm cells were treated with apoptosis inducers (betulinic acid, thapsigargin), acrosome reaction inducers (thapsigargin, calcium ionophore), or hydrogen peroxide.
  • Treatments were performed with and without a calcium chelator (NP-EGTA, AM).
  • Analyses included computer-assisted sperm analysis, flow cytometry, and transmission electron microscopy.

Main Results:

  • Induction of apoptosis and acrosome reaction led to increased caspase 9 and caspase 3 activation, disrupted mitochondrial membrane potential, and acrosome-reacted sperm.
  • Sperm motility decreased across all treatment groups.
  • Transmission electron microscopy revealed ultra-morphological changes indicative of apoptosis and acrosome reaction.
  • Reducing intracellular calcium with NP-EGTA, AM significantly decreased acrosome reaction and apoptotic features.

Conclusions:

  • High intracellular calcium levels can mediate apoptotic cell death in acrosome-reacted human sperm.
  • Apoptosis is a functional pathway in mature spermatozoa that can be influenced by calcium concentration.
  • These findings provide insights into sperm physiology and potential mechanisms affecting male fertility.
Keywords:
acrosome reactionapoptosishuman spermatozoaultra-morphology

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