TY - JOUR
T1 - Differential sperm histone retention in normozoospermic ejaculates of infertile men negatively affects sperm functional competence and embryo quality
AU - Pandya, Riddhi Kirit
AU - Jijo, Ameya
AU - Cheredath, Aswathi
AU - Uppangala, Shubhashree
AU - Salian, Sujith Raj
AU - Lakshmi, Vani R.
AU - Kumar, Pratap
AU - Kalthur, Guruprasad
AU - Gupta, Sanjay
AU - Adiga, Satish Kumar
N1 - Funding Information:
The facilities provided by the NMR Research Centre at the Indian Institute of Science, Bengaluru, and the Advanced Centre for Treatment, Research, and Education in Cancer, Tata Memorial Centre, Navi Mumbai, India, are gratefully acknowledged. Aswathi Cheredath and Ameya Jijo acknowledge the Dr. TMA Pai Doctoral Fellowship from the Manipal Academy of Higher Education. This work was supported by research grants from the Indian Council of Medical Research (ICMR # 5/10/FR/8/2014‐RCH).
Publisher Copyright:
© 2023 The Authors. Andrology published by Wiley Periodicals LLC on behalf of American Society of Andrology and European Academy of Andrology.
PY - 2023
Y1 - 2023
N2 - Background: The unique epigenetic architecture that sperm cells acquire during spermiogenesis by retaining <15% of either canonical or variant histone proteins in their genome is essential for normal embryogenesis. Whilst heterogeneous levels of retained histones are found in morphologically normal spermatozoa, their effect on reproductive outcomes is not fully understood. Methods: Processed spermatozoa (n = 62) were tested for DNA integrity by sperm chromatin dispersion assay, and retained histones were extracted and subjected to dot-blot analysis. The impact of retained histone modifications in normozoospermic patients on sperm functional characteristics, embryo quality, metabolic signature in embryo spent culture medium and pregnancy outcome was studied. Results: Dot-blot analysis showed heterogeneous levels of retained histones in the genome of normozoospermic ejaculates. Post-wash sperm yield was affected by an increase in H3K27Me3 and H4K20Me3 levels in the sperm chromatin (p < 0.05). Also, spermatozoa with higher histone H3 retention had increased DNA damage (p < 0.05). Spermatozoa from these cohorts, when injected into donor oocytes, correlated to a significant decrease in the fertilisation rate with an increase in sperm histone H3 (p < 0.05) and H3K27Me3 (p < 0.01). An increase in histone H3 negatively affected embryo quality (p < 0.01) and clinical pregnancy outcome post-embryo transfer (p < 0.05). On the other hand, spent culture medium metabolites assessed by high-resolution (800 MHz) nuclear magnetic resonance showed an increased intensity of the amino acid methionine in the non-pregnant group than in the pregnant group (p < 0.05) and a negative correlation with sperm histone H3 in the pregnant group (p < 0.05). Discussion and conclusion: Histone retention in spermatozoa can be one of the factors behind the development of idiopathic male infertility. Such spermatozoa may influence embryonic behaviour and thereby affect the success rate of assisted reproductive technology procedures. These results, although descriptive in nature, warrant further research to address the underlying mechanisms behind these clinically important observations.
AB - Background: The unique epigenetic architecture that sperm cells acquire during spermiogenesis by retaining <15% of either canonical or variant histone proteins in their genome is essential for normal embryogenesis. Whilst heterogeneous levels of retained histones are found in morphologically normal spermatozoa, their effect on reproductive outcomes is not fully understood. Methods: Processed spermatozoa (n = 62) were tested for DNA integrity by sperm chromatin dispersion assay, and retained histones were extracted and subjected to dot-blot analysis. The impact of retained histone modifications in normozoospermic patients on sperm functional characteristics, embryo quality, metabolic signature in embryo spent culture medium and pregnancy outcome was studied. Results: Dot-blot analysis showed heterogeneous levels of retained histones in the genome of normozoospermic ejaculates. Post-wash sperm yield was affected by an increase in H3K27Me3 and H4K20Me3 levels in the sperm chromatin (p < 0.05). Also, spermatozoa with higher histone H3 retention had increased DNA damage (p < 0.05). Spermatozoa from these cohorts, when injected into donor oocytes, correlated to a significant decrease in the fertilisation rate with an increase in sperm histone H3 (p < 0.05) and H3K27Me3 (p < 0.01). An increase in histone H3 negatively affected embryo quality (p < 0.01) and clinical pregnancy outcome post-embryo transfer (p < 0.05). On the other hand, spent culture medium metabolites assessed by high-resolution (800 MHz) nuclear magnetic resonance showed an increased intensity of the amino acid methionine in the non-pregnant group than in the pregnant group (p < 0.05) and a negative correlation with sperm histone H3 in the pregnant group (p < 0.05). Discussion and conclusion: Histone retention in spermatozoa can be one of the factors behind the development of idiopathic male infertility. Such spermatozoa may influence embryonic behaviour and thereby affect the success rate of assisted reproductive technology procedures. These results, although descriptive in nature, warrant further research to address the underlying mechanisms behind these clinically important observations.
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U2 - 10.1111/andr.13541
DO - 10.1111/andr.13541
M3 - Article
C2 - 37801310
AN - SCOPUS:85173500660
SN - 2047-2919
VL - 12
SP - 881
EP - 890
JO - Andrology
JF - Andrology
IS - 4
ER -
