Login to Access Video or Poster Abstract: MP07-18
Sources of Funding: none

Introduction

About 10-15% of all infertility patients are diagnosed with idiopathic infertility. Particularly, long term smokers often suffer from a reduction of basic sperm parameters (Ramlau-Hansen, 2007). The effects of smoking on male fertility are still discussed controversially._x000D_ It was shown, that the essential binding between sperm and oviduct is based on a lectine-carbohydrate interaction (Koelle, 2012). A functional reduction of fertility could occur due to a lack of binding capacity._x000D_ Therefore, our group characterized the proteins on glycocalyx of human spermatozoa that are capable to bind sugar residues. Further it was evaluated, if smokers show a restricted sugar-binding ability compared to non-smokers._x000D_

Methods

We separated two study populations (smokers, non-smokers) out of 78 fresh human ejaculate samples. A direct staining with Mitotracker DeepRed, NucBlue (DAPI) and FITC-conjugated sugar residues (sialic acid- (SA), mannose- (MA) and fucose- (FU)) was performed. We used confocal microscopy to examine the fluorescence-marked samples. The fluorescent cells were analysed quantitatively and qualitatively within the study populations._x000D_ Additionally, we extracted the sperm's proteins from smokers and control group which we applied on SDS-Page (4-12.5 %). Western Blot was used to proof the presence of LMAN2 and CatSper1 proteins on the plasma membrane surface._x000D_

Results

We located proteins at the middle part of the spermatozoa's head that are capable of binding sugar residues._x000D_ The ratio of fluorescence-labelled cells to the total cell count, which correspond to the capacity of binding sugar residues, was measured. We showed a significant difference between the groups: For smokers, we counted a proportion of 0.07±0.006 (SA), 0.05±0.006 (MA), 0.05±0.005 (FU) compared to 0.15±0.01 (SA), 0.20±0.02 (MA), 0.19±0.02 (FU) for the non-smokers (p<0.05). Fluorescence intensity did not vary significantly between the groups._x000D_ Protein candidates were found in Western Blot but first experiments did not show a significant difference in the amount between smokers and non-smokers.

Conclusions

Our results point out, that smoking could possibly lead to a reduction of sugar binding proteins on the human sperm glycocalyx. This could be a reason for a decreased binding capacity of sperms to the female reproductive tract which could lead to a reduced fertility potential of smokers. Further work is necessary to lighten the exact molecular interaction between spermatozoa and female reproductive tract. Based on these facts it might be possible to examine new diagnostic and therapeutic approach in the future.

Funding

none