Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers from the Université Libre de Bruxelles show that a rhesus factor controls renal functionand male fertility

20.11.2008
The “Rhesus” blood group is well-known from the public for its importance in the field of transfusion medicine.

For several years, researchers from ULB have been studying Rhesus factors. These factors belong to a family comprising five proteins, three of which are present at the red cell surface (RhCE, RhD and RhAG) and determine the Rhesus blood group, and two others (RhBG and RhCG) which are found in various organs including the kidney, the liver and the male genital tract.

The function of Rhesus factors remained completely unknown till Dr. Anna Maria Marini (Research associate from the FNRS) and her collaborators (Laboratory of Molecular Physiology of the Cell, Prof. Bruno André, ULB, IBMM, Charleroi) established a relationship between Rhesus factors and yeast ammonium transporters. Ammonium is used as a major nitrogen source by microbes and plants but is rather known for its toxicity and its implication in the regulation of blood acidity (pH) in mammals. In 2000, this research group proposes that Rhesus factors play a role in the transport of ammonium in mammals, a process also remaining unknown in animals. This hypothesis was tested by Dr. Sophie Biver during her doctoral thesis performed in the Laboratory of Biology of Development (Profs Josiane and Claude Szpirer, also at IBMM, ULB), in collaboration with the group of Dr. Marini.

The results of their research is published this 20 November in the prestigious review Nature.

The basic idea is simple: to generate mice deprived of the RHCG gene (the one expressed in the kidney) in order to determine if as proposed, these mice would present anomalies related to a defect in ammonium transport, and in particular to a defect in ammonium excretion in the urine. The mice obtained, bearing an invalidation of the RHCG gene and thus deprived of any RhCG protein, appeared viable but their urine contains too low amounts of ammonium, especially if their food is acid, which has for major consequences an altered blood pH which is too acid and a significant loss of weight.

This discovery - which validates the starting assumption – leads to the revision of the concept taught since the 1940th according to which renal ammonium excretion occurs solely by a process of passive diffusion (which does not imply the function of a protein). These mice show the characteristics of human genetic renal pathologies known under the name of distal renal tubular acidosis and whose determinants are not completely known.

Moreover, the researchers observed that invalidated male mice generated litters of reduced size (whereas invalidated females have a normal fertility). This observation is consistent with the fact that the RHCG gene is expressed in the male genital tract where the fluid of the epididymis shows an abnormal pH (it is too acid) in invalidated mice.

These observations have implications in human medicine. They suggest that in man, mutations affecting the RHCG gene could cause some forms of renal pathologies and/or a loss of male fertility. This last suggestion is relevant knowing that certain observations indicate a reduction of the quality of human sperm, in particular in Western populations.

Co-ordinated by the Université libre de Bruxelles- Institut de biologie et de médecine moléculaires, IBMM -, this research was carried out in collaboration with three other teams (Pr. Oliver Devuyst, Université Catholique de Louvain; Pr. C.A. Wagner, Université de Zurich; Dr P. Houillier, Université Pierre et Marie Curie).

A role for Rhesus factor Rhcg in renal ammonium excretion and male fertility.
Biver, S., Belge, H., Bourgeois, S., Van Vooren, P., Novick, M., Scohy, S., Houillier, P., Szpirer, J., Szpirer, C., Wagner, C.A., Devuyst, O., Marini, A.M., Nature, 20 November 2008
Scientific information:
Anna Maria Marini, IBMM-ULB : +32 (0)2 650 99 57, Anna.Maria.Marini@ulb.ac.be

Nancy Dath | alfa
Further information:
http://www.ulb.ac.be

More articles from Life Sciences:

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>