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Major protein alterations in spermatozoa from infertile men with unilateral varicocele.

Agarwal A, Sharma R, Durairajanayagam D, Ayaz A, Cui Z, Willard B, Gopalan B, Sabanegh E - Reprod. Biol. Endocrinol. (2015)

Bottom Line: Proteins were extracted and separated by 1-D SDS-PAGE.Bands were digested and identified on a LTQ-Orbitrap Elite hybrid mass spectrometer system.Bioinformatic analysis identified the pathways and functions of the differentially expressed proteins (DEP).

View Article: PubMed Central - PubMed

Affiliation: Center for Reproductive Medicine, Glickman Urological & Kidney Institute, Cleveland Clinic, Mail Code X-11, 10681 Carnegie Avenue, Cleveland, OH, 44195, USA. agarwaa@ccf.org.

ABSTRACT

Background: The etiology of varicocele, a common cause of male factor infertility, remains unclear. Proteomic changes responsible for the underlying pathology of unilateral varicocele have not been evaluated. The objective of this prospective study was to employ proteomic techniques and bioinformatic tools to identify and analyze proteins of interest in infertile men with unilateral varicocele.

Methods: Spermatozoa from infertile men with unilateral varicocele (n=5) and from fertile men (control; n=5) were pooled in two groups respectively. Proteins were extracted and separated by 1-D SDS-PAGE. Bands were digested and identified on a LTQ-Orbitrap Elite hybrid mass spectrometer system. Bioinformatic analysis identified the pathways and functions of the differentially expressed proteins (DEP).

Results: Sperm concentration, motility and morphology were lower, and reactive oxygen species levels were higher in unilateral varicocele patients compared to healthy controls. The total number of proteins identified were 1055, 1010 and 1042 in the fertile group, and 795, 713 and 763 proteins in the unilateral varicocele group. Of the 369 DEP between both groups, 120 proteins were unique to the fertile group and 38 proteins were unique to the unilateral varicocele group. Compared to the control group, 114 proteins were overexpressed while 97 proteins were underexpressed in the unilateral varicocele group. We have identified 29 proteins of interest that are involved in spermatogenesis and other fundamental reproductive events such as sperm maturation, acquisition of sperm motility, hyperactivation, capacitation, acrosome reaction and fertilization. The major functional pathways of the 359 DEP related to the unilateral varicocele group involve metabolism, disease, immune system, gene expression, signal transduction and apoptosis. Functional annotations showed that unilateral varicocele mostly affected small molecule biochemistry and post-translational modification proteins. Proteins expressed uniquely in the unilateral varicocele group were cysteine-rich secretory protein 2 precursor (CRISP2) and arginase-2 (ARG2).

Conclusions: The expression of these proteins of interest are altered and possibly functionally compromised in infertile men with unilateral varicocele. If validated, these proteins may lead to potential biomarker(s) and help better understand the mechanism involved in the pathophysiology of unilateral varicocele in infertile men.

No MeSH data available.


Related in: MedlinePlus

Expression levels of differentially expressed proteins. A. The number of DEPs that were uniquely expressed either in the fertile or unilateral varicocele group and their respective levels of expression (up-regulated or down-regulated) in the two groups. B. Expression levels of differentially expressed proteins. The abundance of differentially expressed proteins - high, medium, low or very low in the fertile and unilateral varicocele group.
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Fig2: Expression levels of differentially expressed proteins. A. The number of DEPs that were uniquely expressed either in the fertile or unilateral varicocele group and their respective levels of expression (up-regulated or down-regulated) in the two groups. B. Expression levels of differentially expressed proteins. The abundance of differentially expressed proteins - high, medium, low or very low in the fertile and unilateral varicocele group.

Mentions: The protein quantitation was performed using the Normalized Spectral Abundance Factor (NSAF), which is based on spectra counts, and therefore all 1191 proteins were quantified in this analysis. Differentially expressed proteins (DEP) were identified based on the filtering criteria given in the procedures section. A total of 369 DEP were identified in the infertile men with varicocele and fertile controls. The Venn diagram shows the distribution of these proteins (Figure 1). 120 of the DEP were unique to the fertile group and 38 were unique to unilateral varicocele group. 211 proteins were common to both groups and were either overexpressed or underexpressed. Among the 120 proteins unique to the fertile control group, 64 were present in the low abundance, 31 in very low abundance and 25 proteins in medium abundance. Thirty eight proteins were unique to the unilateral varicocele group. Of these, 7/38 (18.4%) proteins showed medium expression level, 25/38 (65.8%) in low abundance and 6/38 (15.8%) very low abundance. When compared to the control group, 114 proteins were overexpressed in the varicocele group, of these 23/114 (20.2%) proteins showed high abundance; 73/114 (64%) medium abundance and 18/114 (15.8%) low abundance. Similarly compared to the control group, 97 proteins were underexpressed in the unilateral varicocele group, of which 23/97 (23.7%) proteins showed high abundance, 73/97 (75.3%) exhibited medium expression levels and 18/97 (18.6% low abundance (Figure 2A). The distribution of high, medium, low and very low proteins in the control and the unilateral varicocele groups is shown in Figure 2B.Figure 1


Major protein alterations in spermatozoa from infertile men with unilateral varicocele.

Agarwal A, Sharma R, Durairajanayagam D, Ayaz A, Cui Z, Willard B, Gopalan B, Sabanegh E - Reprod. Biol. Endocrinol. (2015)

Expression levels of differentially expressed proteins. A. The number of DEPs that were uniquely expressed either in the fertile or unilateral varicocele group and their respective levels of expression (up-regulated or down-regulated) in the two groups. B. Expression levels of differentially expressed proteins. The abundance of differentially expressed proteins - high, medium, low or very low in the fertile and unilateral varicocele group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4383193&req=5

Fig2: Expression levels of differentially expressed proteins. A. The number of DEPs that were uniquely expressed either in the fertile or unilateral varicocele group and their respective levels of expression (up-regulated or down-regulated) in the two groups. B. Expression levels of differentially expressed proteins. The abundance of differentially expressed proteins - high, medium, low or very low in the fertile and unilateral varicocele group.
Mentions: The protein quantitation was performed using the Normalized Spectral Abundance Factor (NSAF), which is based on spectra counts, and therefore all 1191 proteins were quantified in this analysis. Differentially expressed proteins (DEP) were identified based on the filtering criteria given in the procedures section. A total of 369 DEP were identified in the infertile men with varicocele and fertile controls. The Venn diagram shows the distribution of these proteins (Figure 1). 120 of the DEP were unique to the fertile group and 38 were unique to unilateral varicocele group. 211 proteins were common to both groups and were either overexpressed or underexpressed. Among the 120 proteins unique to the fertile control group, 64 were present in the low abundance, 31 in very low abundance and 25 proteins in medium abundance. Thirty eight proteins were unique to the unilateral varicocele group. Of these, 7/38 (18.4%) proteins showed medium expression level, 25/38 (65.8%) in low abundance and 6/38 (15.8%) very low abundance. When compared to the control group, 114 proteins were overexpressed in the varicocele group, of these 23/114 (20.2%) proteins showed high abundance; 73/114 (64%) medium abundance and 18/114 (15.8%) low abundance. Similarly compared to the control group, 97 proteins were underexpressed in the unilateral varicocele group, of which 23/97 (23.7%) proteins showed high abundance, 73/97 (75.3%) exhibited medium expression levels and 18/97 (18.6% low abundance (Figure 2A). The distribution of high, medium, low and very low proteins in the control and the unilateral varicocele groups is shown in Figure 2B.Figure 1

Bottom Line: Proteins were extracted and separated by 1-D SDS-PAGE.Bands were digested and identified on a LTQ-Orbitrap Elite hybrid mass spectrometer system.Bioinformatic analysis identified the pathways and functions of the differentially expressed proteins (DEP).

View Article: PubMed Central - PubMed

Affiliation: Center for Reproductive Medicine, Glickman Urological & Kidney Institute, Cleveland Clinic, Mail Code X-11, 10681 Carnegie Avenue, Cleveland, OH, 44195, USA. agarwaa@ccf.org.

ABSTRACT

Background: The etiology of varicocele, a common cause of male factor infertility, remains unclear. Proteomic changes responsible for the underlying pathology of unilateral varicocele have not been evaluated. The objective of this prospective study was to employ proteomic techniques and bioinformatic tools to identify and analyze proteins of interest in infertile men with unilateral varicocele.

Methods: Spermatozoa from infertile men with unilateral varicocele (n=5) and from fertile men (control; n=5) were pooled in two groups respectively. Proteins were extracted and separated by 1-D SDS-PAGE. Bands were digested and identified on a LTQ-Orbitrap Elite hybrid mass spectrometer system. Bioinformatic analysis identified the pathways and functions of the differentially expressed proteins (DEP).

Results: Sperm concentration, motility and morphology were lower, and reactive oxygen species levels were higher in unilateral varicocele patients compared to healthy controls. The total number of proteins identified were 1055, 1010 and 1042 in the fertile group, and 795, 713 and 763 proteins in the unilateral varicocele group. Of the 369 DEP between both groups, 120 proteins were unique to the fertile group and 38 proteins were unique to the unilateral varicocele group. Compared to the control group, 114 proteins were overexpressed while 97 proteins were underexpressed in the unilateral varicocele group. We have identified 29 proteins of interest that are involved in spermatogenesis and other fundamental reproductive events such as sperm maturation, acquisition of sperm motility, hyperactivation, capacitation, acrosome reaction and fertilization. The major functional pathways of the 359 DEP related to the unilateral varicocele group involve metabolism, disease, immune system, gene expression, signal transduction and apoptosis. Functional annotations showed that unilateral varicocele mostly affected small molecule biochemistry and post-translational modification proteins. Proteins expressed uniquely in the unilateral varicocele group were cysteine-rich secretory protein 2 precursor (CRISP2) and arginase-2 (ARG2).

Conclusions: The expression of these proteins of interest are altered and possibly functionally compromised in infertile men with unilateral varicocele. If validated, these proteins may lead to potential biomarker(s) and help better understand the mechanism involved in the pathophysiology of unilateral varicocele in infertile men.

No MeSH data available.


Related in: MedlinePlus