PhD student of the Department of Biology and General Genetics Ait Aissa A.¹
Dr.Biol., Associate Professor, Head of the Department of Biology and General Genetics Azova M.M.¹
PhD, Associate Professor of the Department of Biology and General Genetics Gigani O.O.¹
PhD, Associate Professor of the Department of Biology and General Genetics Gigani O.B.¹
Dr.Med., Professor of the Department of General Pathology and Pathophysiology Blagonravov M.L.¹
PhD, Director of the Diagnostic research department Karamyan A.S.²
PhD, chief physician Khodorovich A.M.^3
1Medical Institute of the Peoples' Friendship University of Russia (PFUR), Moscow
²Shared Research and Education Center of the Peoples' Friendship University of Russia (PFUR), Moscow
³Moscow city polyclinic No. 25, Moscow

Keywords:  angiotensin-converting enzyme, population, personalized training.

Introduction. The adaptive mechanism of the cardiovascular and respiratory systems, skeletal muscles, and other factors define the ability to perform sport activities in the individuals. Some genetic polymorphisms are implicated in the effectiveness of these mechanisms.

The gene encoding angiotensin converting enzyme (ACE) was the first gene associated with the human physical performance [6]. It has been shown that the Insertion-deletion (I /D) of 287-base-pair Alu repeat sequence polymorphism in ACE affects levels of plasmatic angiotensin converting enzyme (ACE) activity and the conversion of angiotensin I into the active vasoconstrictor angiotensin II. Numerous studies have demonstrated that D polymorphism allows for the body efforts requiring strength and speed, while allele I ensures endurance [12], however, these associations vary between different populations [1,2,5] hence the characteristic of ACE I/D polymorphism in different populations and ethnic groups must be taken in consideration during the identification of the genetic potential of physical qualities to select the optimal physical activity and develop a personalized approach to training in order to achieve high results. In the present study, we have investigated the distribution of ACE I/D polymorphism among Russians from Central Russia, Algerians and Syrians.

Methods and structure of the study. This study was conducted at the Department of Biology & General Genetics - Medical Institute and in the Shared Knowledge Center of Peoples' Friendship University of Russia. The study group included 55 healthy Algerians with a mean age of 33.4±11.6 years, 40 Syrians (25.5±7.9 years) and 59 Russians from Central Russia (20.5±6.8 years). Determination of insertion (I) / deletion (D) of the ACE gene was carried out by polymerase chain reaction (PCR), followed by detection of the amplification products by electrophoresis in 2% agarose gel. The DNA extraction from the peripheral blood and detection of genotypic variants were performed using a kit (Liteh, Russia) according to manufacturer’s instructions. Statistical analyses were carried out with the «R language» software [7]. Comparisons of the allele and genotype frequencies between populations were assessed using Х² test analyses. The criterion for significance was set at p< 0.05.

Results and Discussion. The ACE genotype and allele distribution are shown in Table 1.

Table 1. Genotypes and allele frequencies of the ACE I/D polymorphism

N= Number of Individuals

The ACE I/D polymorphism was characterized by the presence or absence of a 287-bp Alu repeat sequence in intron 16 of the ACE gene. According to literature data, the plasma level of ACE in individuals with the DD genotype is higher than in those with the II genotype; while heterozygotes ID have an intermediate level of ACE [8]. The homozygotes DD are also characterized by a high activity of the conversion of angiotensin I into angiotensin II.

No significant deviations from the Hardy-Weinberg equilibrium were observed in the studied populations (p>0.05). According to our data, the frequency of the DD genotype in the Algerians significantly exceeds the frequency of ID and II variants, a similar pattern was observed in Syrians although the differences are less pronounced. In the sample of the ethnic Russians - natives of Сentral Russia, we found a different distribution of the studied genotypes, the incidence of heterozygotes substantially higher than the frequency of homozygotes. Thus, the frequency of the studied genotypes among Russians significantly differs from the Algerians (X² = 40.52; P =0.00019), and the Syrians (X² = 19.57; P = 0.038), while a significant difference between the Algerians and Syrians was not found, this can be explained by the fact that the DD genotype is the most common form of ACE polymorphic system among Arab and African populations [3, 9]. A higher frequency of D allele was found in the Algerians and Syrians compared to the Russians (Х²=22.464, p=0.0054; Х²=10.57, p=0.001 respectively), that corresponds to the previously reported results in the North African populations (0.76-0.850), as well as in the Arab populations of the Middle East (0.60-0.73) [3, 4, 9, 10, 11]. As mentioned above, numerous studies have shown that the D allele determines the ability to resist load requiring demonstration of speed and strength. So it is considered as a marker of speed and explosive strength among the sprinters. Whereas I allele is a marker of speed endurance in the group of stayers [12, 13]. However, this association varies between different populations [1, 2, 5], the D allele frequency was high among Israeli athletes engaged in endurance sport and it was also high among Spanish cyclists able to complete multi-day tour races.

This variability can be explained by the genetic characteristics of different ethnic groups. According to our data, the incidence of the DD genotype was increased among the Arabs, while the ID genotype is more prevalent among the Russian population. We should also take into account the possible combinations of many alleles or haplotypes that are associated with sport activities. Therefore, the development of an individual approach to athletic training requires accounting the genetic characteristics of athletes from various ethnic groups.

Conclusion. The results obtained in the present study, showed a significant difference in the distribution of genotypes I / D ACE gene polymorphism between the Russians and Arabs from Algeria and Syria. Thus, to achieve good results and select future elite athletes for a physical activity that requires speed and strength to be displayed the increased frequency of the DD genotype among the Algerians and Syrians should be taken into account.

References

1. Amir O., Amir R., Yamin C., Attias E., Eynon N., Sagiv M., Sagiv M., Meckel Y. The ACE deletion allele is associated with Israeli elite endurance athletes. Exp Physiol. 2007; 92:881-886.
2. Ash G.I., Scott R.A., Deason M., Dawson T.A., Wolde B., Bekele Z., Teka S., Pitsiladis Y.P. No association between ACE gene variation and endurance athlete status in Ethiopians. Med. Sci. Sports Exerc. 2011;(43):590-597.
3. Comas D, Calafell F, Benchemsi N, Helal A, Lefranc G, Stoneking M, Batzer MA, Bertranpetit J, Sajantila A: Alu insertion polymorphisms in NW Africa and the Iberian Peninsula: evidence for a strong genetic boundary through the Gibraltar Straits. Hum Genet 2000, 107:312-319
4. Houcher B, BegagI S, Houcher1 Z, Karabiyik A, Egin Y , Akar N.  Prevalence of genetic polymorphisms of methylenetetrahydrofolate reductase C677T and angiotensin I-converting enzyme (insertion/deletion) in Setif population, Algeria. MBRC 2013; 2(1-2):19-27
5. Lucia A, Gomez-Gallego F, Chicharro JL, Hoyos J, Celaya K, Cordova A, Villa G, Alonso JM, Barriopedro M, Perez M, Earnest CP. Is there an association between ACE and CKMM polymorphisms and cycling performance status during 3-week races? Int J Sports Med. 2005; 26(6):442-7.
6. Montgomery H.E., Marshall R., Hemingway H., Myerson S., Clarkson P., Dollery C., Hayward M., Holliman D.E., Jubb M., World M., Thomas E.L., Brynes A.E., Saeed N., Barnard M.,Bell J.D., Prasad K., Rayson M.,Talmud P.J., Humphries S.E. Human gene for physical performance. Nature 1998; 393:221-222.
7. R Core Team.2015. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL http://www.R-project.org/.
8. Sakuma T.; Hirata R. D. and Hirata M. H. Five polymorphisms in gene candidates for cardiovascular disease in Afro-Brazilian individuals. J. Clin. Lab. Anal. 2004;18: 309–316
9. Salem A. and A. Batzer. High frequency of the D allele of the angiotensin-converting enzyme gene in Arabic populations. BMC Research Notes 2009, 2:99
10. They-They TP, Hamzi K, Moutawafik MT, Bellayou H, El Messal M, Nadifi S. Prevalence of angiotensin-converting enzyme, methylenetetrahydrofolate reductase, Factor V Leiden, prothrombin and apolipoprotein E gene polymorphisms in Morocco. Ann Hum Biol. 2010; 37(6):767-77.
11. Ulu A, Elsobky E, Elsayed M, et al. Frequency of five throm­bophilic polymorphisms in the Egyptian population. Turk J Hematol 2006; 23: 100–103.
12. Wang P., Fedoruk M.N., Rupert J.L. Keeping pace with ACE: are ACE inhibitors and angiotensin II type 1 receptor antagonists potential doping agents? Sports Med. 2008;38:1065-1079.
13. Znazen H, Touhami I, Chtara M, Le Gallais D, Ahmetov II, Chamari K, Soussi N. Genetic advantageous predisposition of angiotensin converting enzyme id polymorphism in tunisian athletes. Sports Med Phys Fitness. 2015 May 6.

Corresponding author: ait.mira90@hotmail.fr

Abstract

We investigated the distribution of I/D ACE polymorphism, which predisposes to sports activity among the Arab populations of Algeria and Syria, as well as in the Russians from Central Russia. The ACE genotypes were established using polymerase chain reaction (PCR) for 55 healthy Algerians with the mean age of 33.4±11.6 years, 40 Syrians (25.5±7.9 years) and 59 Russians (20.5±6.8 years). A significant difference was found in the ACE genotype distribution between the Russians and Algerians (Х² = 40.52; Р=0.00019), and between the Russians and Syrians (Х² = 19.57; Р =0.038). The results show the I/D ACE polymorphism among the Arabs and Russians should be considered in the identification of the genetic potential of physical qualities to select the optimal physical activity and develop a personalized approach to training in order to achieve best athletic performance. The research was conducted at the Department of Biology and General Genetics, Medical Institute of Peoples' Friendship University of Russia.