Clinical M edicine and Diagnostics 2013, 3(5): 123-128 DOI: 10.5923/j.cmd.20130305.06
Angiotensin Converting Enzyme (ACE) and Angiotensin II Type I Receptor (ATIR) Polymorphisms in Egyptian Preeclamptic Patients Eman S Kamha1 , Doaa A Abdelmonsif1,* , Tamer M H Abdeldaim2 1 Department of medical biochemistry, Faculty of medicine, Alexandria University, 21511, Egypt Department of obstetric and gynecology, Faculty of medicine, Alexandria University, 21526, Egypt
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Abstract The aim of the present study was to investigate the possible associations of ACE I/D and AT1R A1166C
genotypes and alleles with the risk of preeclampsia in Egypt. The study was conducted on 65 wo men with severe preeclampsia and 25 age and parity-matched controls. They were selected fro m the obstetric clin ic of Elshatby Hospital, faculty of medicine, Alexandria University, Egypt. All patients were subjected to full history taking, clinical examination, serum uric acid, liver function tests (ALT &AST), and determination of fetal outcome (fetal distress state). Patients and controls were subjected to ACE I/ D gene polymorphis m analysis by polymerase chain reaction (PCR) and AT1R A1166C gene polymorphism analysis by PCR-restriction frag ment length polymorphism (RFLP). Both DD and ID genotypes of the ACE gene showed a significant relat ion to the occurrence of preeclampsia. Additionally, ACE DD genotype was significantly related to early onset preeclampsia. D allele showed a significant relation to the occurrence of early preeclampsia as well. Furthermore, the risk of early preeclampsia was 5.44 fo ld with D allele. The distribution of the AT1R A1166C poly morphis m was similar in the preeclamptic patients and control group. Consequently, ACE gene I/D poly morphis m, but not AT1R gene A1166C, poly morphis m could be related to the occurrence and onset of preeclampsia in Egyptian wo men. When proved by large-scale studies, we might be able to assess patients’ risk of developing preeclampsia especially early-onset preeclampsia. Consequently, preventative or early therapeutic interventions could be considered in order to reduce preeclampsia-associated morb idity and mortality.
Keywords Preeclampsia, Angiotensin Converting Enzy me (A CE), Angiotensin II Type I Receptor (ATIR)
1. Introduction Preeclampsia is a pregnancy-specific d isorder in 6-8% of all pregnancies, mostly in primigravida. Preeclampsia is characterized by new-onset hypertension, proteinuria and vascular dysfunction presenting after the 20th week of gestation.[1,2] It remains a leading cause of maternal and fetal mo rbid ity and mortality worldwide.[3] Preeclampsia is mu ltifactorial d isorder that results fro m co mplex interaction between genetic and environmental factors.[4] During normal pregnancy, because of the stimu lation of the ren in -ang iotens in -aldosteron e system (RAA S), the plasma levels of renin and aldosterone are increased.[5] In contrast, preeclamptic wo men suffer fro m suppression of the RAAS system and are h ighly sensitive to the pressor effects of angiotensin II together with increased vascular res is t an ce an d failu re t o d ev elo p t h e p h ys io lo g ic * Corresponding author:
[email protected] (Doaa A Abdelmonsif) Published online at http://journal.sapub.org/cmd Copyright © 2013 Scientific & Academic Publishing. All Rights Reserved
hypervolemia of pregnancy.[4,6] Genes coding for components of the renin–angiotensin system (RAS) are considered to be candidates that may affect the risk o f gestational hypertension and preeclampsia. Angiotensin-converting enzyme (ACE) is an important circulating enzy me in the RAS, wh ich catalyzes the conversion of angiotensin I to angiotensin II and degrades bradykinin. As a result, it p lays an important ro le in blood pressure homeostasis.[7] A co mmon insertion/deletion (I/D) polymorphis m in intron 16 within the ACE gene was previously reported to be associated with different plas ma ACE levels, and indiv iduals carry ing the D allele had higher ACE activit ies.[7] Furthermo re, several studies, have reported that wo men carrying the D allele of the ACE-I/D polymorphis m had higher ACE act ivity and higher measures of uterine artery resistance, which is a marker for development of intrauterine g rowth retardation and preecla mpsia.[8,9] Angiotensin II, wh ich results fro m enzy mat ic reaction of ACE on angiotensin I, binds to angiotensin II type-1 receptor (AT1R).[10] Angiotensin II-AT1R axis might explain vascular maladaptation in preeclampsia with
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Eman S Kamha et al.: Angiotensin Converting Enzyme (ACE) and Angiotensin II Type I Receptor (ATIR) Polymorphisms in Egyptian Preeclamptic Patients
increased vasomotor tone, endothelial dysfunction, and increased sensitivity to angiotensin II and norepinephrine in man ifest preeclampsia.[8] As a result, enhanced activity of the angiotensin II-AT1R axis was hypothesized to contribute to the complications of preeclampsia.[10] Although ACE and AT1R gene poly morph isms have been studied in other preeclamptic population, their possible role in Egyptian preeclamptic patients hasn’t been settled yet. The aim of the present study is to investigate the frequency of A CE I/D and AT1R A 1166C alleles and genotypes in Egyptian preeclampt ic patients. Moreover, to investigate their possible association with the risk of preeclampsia among Egyptian pregnant women as well as their possible relation to maternal outcome.
amp lification which was performed in a total volu me of 25 μl using optimized primer vo lu mes. The PCR protocol consisted of 5 min at 94ºC, 40 cycles of 30 s at 94ºC, 30 s at 60ºC and 1 min at 72ºC and then, 10 min at 72ºC fo r final extension (What man , Bio met ra, T personal. http://www.bio metra.co m). PCR products were electrophoresed on a 1.5% agarose gel and visualized by UV illu mination[Bio metra. http://www.bio met ra.co m]. A CE II genotype produced a 490-bp frag ment, DD genotype produced a 190-bp frag ment, and ID genotype produced two frag ments of 490 and 190-bp.[12] The AT1R A1166C poly morph ism was detected using RFLP. The PCR react ion included the forward primer of 5’-GCA CCATGTTTTGA GGTTG-3’ and the reverse primer of 5′-CGA CTA CTGCTTA GCATA -3′. A total of ≈100 ng of genomic DNA was used in PCR amp lification 2. Material and Methods which was performed in a total volume o f 25 μl using optimized primer volu mes. The PCR conditions were as The study was conducted on 65 wo men with severe form follows: initial denaturation at 96ºC for 5 min, followed by of preeclampsia and 25 age and parity-matched controls. 35 cycles of denaturation (96ºC fo r 30 s), annealing (55ºC They were selected fro m the obstetric clinic of Elshatby for 30s), and extension (72ºC for 60s). The terminal Hospital, faculty of med icine, Alexandria University, Egypt. extension was performed at 72ºC for 10 min. (What man, An informed written consent was obtained fro m each Bio metra, T personal. http://www.bio metra.com). individual before part icipation in the study. Moreover, the To illustrate the AT1R A1166C poly morphis m, PCR study was approved by the institutional Ethics Co mmittee. products (540 bp) were processed with the restriction Preeclampsia was defined as blood pressure≥140/90 mmHg endonuclease Dde I (Thermo Fisher Scientific Inc. and proteinuria ≥300 mg/24hr. Severe preeclampsia was http://www.thermoscientific.co m/fermentas) at 37ºC, which defined as blood pressure≥160/ 110mmHg, proteinuria cuts the product into two pieces, 430 bp and 110 bp long. ≥2g/24hr, platelet count of
