RESEARCH PROJECTS
Effect of cinnamaldehyde and Eugenol on P-type ATPases and F0 F1 ATPase: Comparative study in Liver, intestine and Kidney membrane fractions P-type ATPase, prototype of which are the Mg++
requiring Na+ /K+- ATPase, Ca++ - ATPase,
Cu++- ATPAse , ion transporters coupled to ATP hydrolysis. Their
common feature is the formation of phosphorylated intermediate in their
reaction cycle where they switch between 2 conformational states E1
& E2 . On the other hand, the mitochondrial F0
F1 ATPase is a proton pump catalyzing phosphorylation of ADP
into ATP. Our preliminary Data have shown that cinnamon and clove, widely
used in food, are inhibitory to Na+/H+ATPase, Cu++
ATPase, but not to F0F1 ATPase. The aim of the study
is to determine the effect of the active ingredients of these spices namely
cinnamaldehyde and eugenol on 1) intestinal transport of alanine 2) Na+/K+
ATPase, Cu++ ATPase and F0 F1 ATPase in
membrane fractions isolated from Liver, kidney and intestine. S. Kreydiyyeh,
J. Usta. (Supported by Biology and Biochemistry Department.)
Identification of molecular and biochemical defects responsible for familial hypercholesterolemia in the Lebanese population Familial hypercholesterolemia (FM) is the most common error
of metabolism worldwise (1/500) leading to tendon xanthomas and premature
coronary heart diseases This disease is caused by mutations in the gene
encoding the low-density lipoprotein receptor. The frequency of this disease
is much higher in the Lebanese population where the estimated frequencies
of homozygotes and heterozygotes are 1 in 10,000 and 1 in 170, respectively.
Despite the high frequency of the FH in Lebanon, only one mutation has
so far been reported in the Lebanese population, and was termed the “Lebanese
allele”. The Lebanese population has a mosaic structure and is known to
be genetically heterogenous. The aim of our study is first to identify
additional mutations responsible for FH in the different Lebanese ethnic
groups and to study their consequences at the protein level. In addition,
the Lebanese population offers an opportunity to study the biochemical
effect associated with compound heterozygotes having 2 different mutations,
since they are 100 times more frequent in Lebanon that in European and
American populations. R. Slim, S. Chamat*, N. Naim*. (Supported
by URB.)
Epidemiological analysis of otosclerosis in Lebanon: mapping of new genes Otosclerosis is a common form of late onset deafness, characterized
by progressive conductive or mixed hearing loss requiring aids and repeated
surgical procedures. More interest is being developed in studying highly
inbred populations or large consanguineous families living in isolated
geographical regions for several generations. In such populations, the
probability of more than one defective gene segregating in the same family
is minimized (Lathrop, 1993). In these cases, a multifactorial disease
may appear to result from either a single locus or a small number of loci
than can be detected by conventional linkage analysis. Taking these epidemiological
data into consideration as well as the high rate of consanguinity within
the different ethnic groups in Lebanon, our population offers an excellent
opportunity to identify new genes responsible for otosclerosis. In addition,
our preliminary data demonstrate the presence of additional genes responsible
for otosclerosis in the Lebanese population. R. Slim, R.J.H. Smith*,
N. Fuleihan, G. Zeitoun, E. El Zir*. (Supported by MPP.)
Subcellular localization of Wilson’s and Menkes gene products: tissue distribution We have reported and described a copper stimulated ATPase
activity in mitochondria of liver, the Wilson (WND) gene expressing tissue.
Similarly Cu++ ATPase activity was demonstrated in: intestine,
the Menkes (MNK) expressing tissue, heart and kidney expressing both gene
products. The high homology in structure suggest that the developed assay
detects probably both the WND and the MNK. Whereas most studies have localized
the MNK protein in the golgi apparatus, the WND localization has been contradictory
and controversially reported to exist in mitochondria (as demonstrated
in our laboratories) and golgi. The objective of the study is to test Cu++
ATPase in golgi apparatus isolated form tissues of normal and LEC rats
(animal model of WND disease) expressing either one or both gene products.
J.
Usta, K. Bajakian, N. Cortas. (Supported by URB, MPP.)
Copper adenosine tri-phosphatase activity in rat liver mitochondria: a new Enzyme or the Wilson Gene Product Copper accumulation in liver characterizes Wilson’s disease.
The cloning of the Wilson Gene (WND) showed that it encodes a copper transporting
P-type ATPase. Protein data base of the cDNA clone of the Wilson gene revealed
a 165 KDa protein of strong homology to the Menkes disease protein expressed
in the intestine. We have recently isolated a rat liver membrane fraction
with copper stimulated ATPase activity. Characterization of the fraction
showed that it is enriched with succinate dehydrogenase activity a marker
enzyme of the inner mitochondrial membrane. The specific activity of the
Cu++ ATPase in isolated mitochondria increased significantly
in mitoplast and inner mitochondrial membrane. Whether the detected enzyme
is a new Cu++ ATPase associated with the mitochondria or the
Wilson gene product remain to be verified. Cu++ ATPase activity
in mitochondria of tissues of high (liver and kidney) versus low (heart
and lungs) WND expression will be compared. In addition, copper transport
in hepatocytes derived from LEC rats will be contrasted and compared to
hepatocytes from normal cells. J. Usta, M. Saban, N. Cortas. (Supported
by DTS, MPP, LNSCR.)
Bou Moghlabey, Y., Nimri, S.*, Sayegh, F.*, El Zir, E.*, Slim, R., Map refinement of the Usher syndrome type IB gene, MYO7A, relative to 11q13.5 microsatellite markers. Clinical Genetics, 54, 155-158, 1998. Chaib*,H., Kaplan, J.*, Gerber, S.*, Vincent,C.*, Ayadi, H.*, Slim,R., Munnich, A.*, Weissenbach, J.*, Petit, C*. A newly identified locus for Usher syndrome type I, USHIE, maps to chromosome 21q21. Human Molecular Genetics, 6, 27-31, 1997. Griffiths, D.E.*, Miller, A.*, Usta, J., Jennings, K*. ESI-MS studies of Heart Mitochondrial Subunit C. Biochemical Society Transactions, 25, 387, 1997. Mustapha, M.*, Azar, S., Bou Moghlabey, Y., Saouda, M., Zeitoun, G., Loiselet, J.*, Slim, R., Further refinement of the Pendred syndrome locus by homozyganalysis to 0.8-cM interval flanked by D7S496 and D7S2425. Journal of Medical Genetics, 35 (3), 202-204, 1998. Nywayri-Salti, N., Haddad, K., Nasr, R., Chamat, S., Usta, J., Canine Leishmaniasis in NorthLebanon. Annals of Tropical Medicine and Parasitology, 91, 221-222, 1997. Saouda, M., Mansour, A., Bou Moghlabey, Y., El Zir ,E.*, Mustapha, M.*, Chaib, H. *, Nehme, A.*, Megarbane, A.*, Loiselet, J.*, Petit, C.*, Slim, R.*, The Usher syndrome in the Lebanese population and further refinement of the USH2A candidate region. Human Genetics, 103, 193-198, 1998. Usta,
J., Barakeh, H., Mahfouz, H., Cortas,N., Copper stimulated Adenosine Triphosphatase
from rat liver: Isolation and Kinetic Characterization. Annals of New
York Academy of Sciences, 834, 475-479, 1997.
ABSTRACTS,
PRESENTATIONS AND PROCEEDINGS
Nuwayri-Salti, N., Sleiman, H.*, Naddaf, M., Usta, J., Chamat, S., Araysi, S.*, Fakhoury, R.*, Knio, K.*, Cutaneous leishmaniasis in Syria, lattikiyeh governorate: immune response in the clinical in two different biotopes. American Society of Tropical Medicine and Hygiene, Washington D.C., 1998. Saouda, M., Mansour, A., El Zir, E.*, Megarbane, A.*, Mustapha, M.*, Nehme, A.*, Zeitoun, G., Loiselet, J.*, Slim, R., Heterogeneite Clinique et Genetique du Syndrome de Usher Type. I et II dans la population Libanaise. VIeme Congres Francophone d’ORL et de Chirugie Cervico-Faciale, Beirut, Lebanon, 1997. Slim, R., Mustapha, M.*, Azar, S., Bou Moghlabey, Y., Sauda, M., Zeitoun, F., Further refinement of the Pendred syndrome locus by homozygosity analysis to 0.8-cM interval flanked by D7S496 and D7S2456. American Journal of Human Genetics, 61, A1720, 1997. Slim, R., Mustapha, M.*, Azar, S., Bou Moghlabey, Y., Sauda, M., Zeitoun, F., Further refinement of the Pendred syndrome locus by homozygosity analysis to 0.8-cM interval flanked by D7S496 and D7S2456. American Society of Human Genetics, Baltimore, USA, 1997. Slim, R., Mansour, A., Bou Moghlabey, Y., El Zir, E.*, Mustapha, A.*, Loiselet, J.*, The Usher syndrome in the Lebanese population: evidence of further genetic heterogeneity in type I and III. American Journal of Human Genetics, 63, A1788, 1998. Slim, R., Mansour, A., Bou Moghlabey, Y., El Zir, E.*, Mustapha, A.*, Loiselet, J.*, The Usher syndrome in the Lebanese population: evidence of further genetic heterogeneity in type I and III. American Journal of Human Genetics, Denver, USA, 1998. Usta, J., Biocidal Effect of organotin flavone complexes; flourescent probes to detect tri-organotin compounds. Third Arab Conference on Modern Biotechnology and Areas of Application in the Arab World, Cairo, Egypt, 1998. Usta,
J., Chakroun, I., Cortas, N., Cu++ ATPase activity in rat liver,
kidney and heart. Possible implication in Wilson’s Disease. Annual Meeting
of the American Society for Biochemistry and Molecular Biology and ASBMB
Satellite Meetings, Washington D.C., USA, 1998.
Abboushi, N., Ceramide inhibits interleukin-2-induction: role of NF-KB (1998). I.F. Durr and G. Dbaibo. Chakroun, I., Tissue distribution of copper adenosine triphosphatase: effect of thiols (1997). J. Usta. Helwani, M., A common molecular mechanism responsible for a familial case of recurrent hydatidiform moles (1998). R. Slim. Mogharbel, N., Molecular characterization of X-chromosome derived markers associated with Tunner syndrome (1998). R. Slim. Rahmeh, A., Subcellular localization of copper adenosine triphosphatase in rat liver (1997). J. Usta. Saouda,
M., Linkage analysis on nine families affected with the Usher syndrome
(1997). R. Slim.
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