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Role of carbonic anhydrase IV in the bicarbonate-mediated activation of murine and human sperm.

Wandernoth PM, Raubuch M, Mannowetz N, Becker HM, Deitmer JW, Sly WS, Wennemuth G - PLoS ONE (2010)

Bottom Line: We demonstrate murine and human sperm respond to CO(2) with an increase in beat frequency, an effect that can be inhibited by ethoxyzolamide.Comparing CA activity in sperm from wild-type and CA IV(-/-) mice we found a 32.13% reduction in total CA activity in the latter.The CA IV(-/-) sperm also have a reduced response to CO(2).

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy and Cell Biology, Saarland University, Homburg, Saar, Germany.

ABSTRACT
HCO(3) (-) is the signal for early activation of sperm motility. In vivo, this occurs when sperm come into contact with the HCO(3) (-) containing fluids in the reproductive tract. The activated motility enables sperm to travel the long distance to the ovum. In spermatozoa HCO(3) (-) stimulates the atypical sperm adenylyl cyclase (sAC) to promote the cAMP-mediated pathway that increases flagellar beat frequency. Stimulation of sAC may occur when HCO(3) (-) enters spermatozoa either directly by anion transport or indirectly via diffusion of CO(2) with subsequent hydration by intracellular carbonic anhydrase (CA). We here show that murine sperm possess extracellular CA IV that is transferred to the sperm surface as the sperm pass through the epididymis. Comparison of CA IV expression by qRT PCR analysis confirms that the transfer takes place in the corpus epididymidis. We demonstrate murine and human sperm respond to CO(2) with an increase in beat frequency, an effect that can be inhibited by ethoxyzolamide. Comparing CA activity in sperm from wild-type and CA IV(-/-) mice we found a 32.13% reduction in total CA activity in the latter. The CA IV(-/-) sperm also have a reduced response to CO(2). While the beat frequency of wild-type sperm increases from 2.86±0.12 Hz to 6.87±0.34 Hz after CO(2) application, beat frequency of CA IV(-/-) sperm only increases from 3.06±0.20 Hz to 5.29±0.47 Hz. We show, for the first time, a physiological role of CA IV that supplies sperm with HCO(3) (-), which is necessary for stimulation of sAC and hence early activation of spermatozoa.

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CASA of sperm from CA −/− mice.Differences in motility parameters between wild-type sperm and sperm of CA IV−/− mice. Sperm motility parameters were determined by using a computer-assisted sperm analysis (CASA) system. In comparison to wild-type sperm the number of motile and the quantity of fast progressive sperm of CA IV−/− is significantly reduced (wild-type: 57.50±4.67%; 35.38±3.69%; CA IV−/−: 35.75±7.46%; 20.25±5.29%) No difference between sperm of wild-type and CA IV−/− is detectable in average velocity and slow progressive motility (n = 8).
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pone-0015061-g006: CASA of sperm from CA −/− mice.Differences in motility parameters between wild-type sperm and sperm of CA IV−/− mice. Sperm motility parameters were determined by using a computer-assisted sperm analysis (CASA) system. In comparison to wild-type sperm the number of motile and the quantity of fast progressive sperm of CA IV−/− is significantly reduced (wild-type: 57.50±4.67%; 35.38±3.69%; CA IV−/−: 35.75±7.46%; 20.25±5.29%) No difference between sperm of wild-type and CA IV−/− is detectable in average velocity and slow progressive motility (n = 8).

Mentions: Figure 6 compares the motility parameters of CASA determined for sperm of wild type and of CA IV−/− mice in the absence of bicarbonate. In CA IV−/−, the total motility is significantly decreased (35.75±7.46%) as compared to wild-type sperm (57.50±4.67%). In addition, the amount of fast progressive sperm is also significantly lower in CA IV−/− mice (20.25±5.29% as compared to 35.38±3.69%). No significant changes is observed in the comparison of the average velocity of CA IV−/− and wild-type sperm (wild-type: 34.75±2.49 µm/s; CA IV−/−: 26.38±3.93 µm/s). There are also no significant changes in slow progressive sperm from wild-type mice and CA IV−/− mice (wild-type: 22.13±1.97%; CA IV−/−: 15.50±2.65%).


Role of carbonic anhydrase IV in the bicarbonate-mediated activation of murine and human sperm.

Wandernoth PM, Raubuch M, Mannowetz N, Becker HM, Deitmer JW, Sly WS, Wennemuth G - PLoS ONE (2010)

CASA of sperm from CA −/− mice.Differences in motility parameters between wild-type sperm and sperm of CA IV−/− mice. Sperm motility parameters were determined by using a computer-assisted sperm analysis (CASA) system. In comparison to wild-type sperm the number of motile and the quantity of fast progressive sperm of CA IV−/− is significantly reduced (wild-type: 57.50±4.67%; 35.38±3.69%; CA IV−/−: 35.75±7.46%; 20.25±5.29%) No difference between sperm of wild-type and CA IV−/− is detectable in average velocity and slow progressive motility (n = 8).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2991337&req=5

pone-0015061-g006: CASA of sperm from CA −/− mice.Differences in motility parameters between wild-type sperm and sperm of CA IV−/− mice. Sperm motility parameters were determined by using a computer-assisted sperm analysis (CASA) system. In comparison to wild-type sperm the number of motile and the quantity of fast progressive sperm of CA IV−/− is significantly reduced (wild-type: 57.50±4.67%; 35.38±3.69%; CA IV−/−: 35.75±7.46%; 20.25±5.29%) No difference between sperm of wild-type and CA IV−/− is detectable in average velocity and slow progressive motility (n = 8).
Mentions: Figure 6 compares the motility parameters of CASA determined for sperm of wild type and of CA IV−/− mice in the absence of bicarbonate. In CA IV−/−, the total motility is significantly decreased (35.75±7.46%) as compared to wild-type sperm (57.50±4.67%). In addition, the amount of fast progressive sperm is also significantly lower in CA IV−/− mice (20.25±5.29% as compared to 35.38±3.69%). No significant changes is observed in the comparison of the average velocity of CA IV−/− and wild-type sperm (wild-type: 34.75±2.49 µm/s; CA IV−/−: 26.38±3.93 µm/s). There are also no significant changes in slow progressive sperm from wild-type mice and CA IV−/− mice (wild-type: 22.13±1.97%; CA IV−/−: 15.50±2.65%).

Bottom Line: We demonstrate murine and human sperm respond to CO(2) with an increase in beat frequency, an effect that can be inhibited by ethoxyzolamide.Comparing CA activity in sperm from wild-type and CA IV(-/-) mice we found a 32.13% reduction in total CA activity in the latter.The CA IV(-/-) sperm also have a reduced response to CO(2).

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy and Cell Biology, Saarland University, Homburg, Saar, Germany.

ABSTRACT
HCO(3) (-) is the signal for early activation of sperm motility. In vivo, this occurs when sperm come into contact with the HCO(3) (-) containing fluids in the reproductive tract. The activated motility enables sperm to travel the long distance to the ovum. In spermatozoa HCO(3) (-) stimulates the atypical sperm adenylyl cyclase (sAC) to promote the cAMP-mediated pathway that increases flagellar beat frequency. Stimulation of sAC may occur when HCO(3) (-) enters spermatozoa either directly by anion transport or indirectly via diffusion of CO(2) with subsequent hydration by intracellular carbonic anhydrase (CA). We here show that murine sperm possess extracellular CA IV that is transferred to the sperm surface as the sperm pass through the epididymis. Comparison of CA IV expression by qRT PCR analysis confirms that the transfer takes place in the corpus epididymidis. We demonstrate murine and human sperm respond to CO(2) with an increase in beat frequency, an effect that can be inhibited by ethoxyzolamide. Comparing CA activity in sperm from wild-type and CA IV(-/-) mice we found a 32.13% reduction in total CA activity in the latter. The CA IV(-/-) sperm also have a reduced response to CO(2). While the beat frequency of wild-type sperm increases from 2.86±0.12 Hz to 6.87±0.34 Hz after CO(2) application, beat frequency of CA IV(-/-) sperm only increases from 3.06±0.20 Hz to 5.29±0.47 Hz. We show, for the first time, a physiological role of CA IV that supplies sperm with HCO(3) (-), which is necessary for stimulation of sAC and hence early activation of spermatozoa.

Show MeSH