Research Articles (Medical Bioscience)

Permanent URI for this collection

https://hdl.handle.net/10566/77

Browse

Browsing by Author "Agarwal, A."

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Association between promoter methylation of MLH1 and MSH2 and reactive oxygen species in oligozoospermic men—A pilot study
    (Wiley, 2017) Gunes, S.; Agarwal, A.; Henkel, Ralf; Sharma, Rajan; Esteves, S.C.; Aljowair, A.; Emirzeoglu, D.; Alkhani, A.; Pelegrini, L.; Joumah, A.; Sabanegh, E.; Mahmutoglu, A.M.
    MLH1 and MSH2 are important genes for DNA mismatch repair and crossing over during meiosis and are implicated in male infertility. Therefore, the methylation patterns of the DNA mismatch repair genes MLH1 and MSH2 in oligozoospermic males were investigated. Ten oligozoospermic patients and 29 normozoospermic donors were analysed. Methylation profiles of the MLH1 and MSH2 promotors were analysed. In addition, sperm motility and seminal reactive oxygen species (ROS) were recorded. Receiver operating characteristic (ROC) analysis was conducted to determine the accuracy of the DNA methylation status of MLH1 and MSH2 to distinguish between oligozoospermic and normozoospermic men. In oligozoospermic men, MLH1 was significantly (p = .0013) more methylated compared to normozoospermic men. Additionally, there was a significant positive association (r = .384; p = .0159) between seminal ROS levels and MLH1 methylation. Contrary, no association between MSH2 methylation and oligozoospermia was found. ROC curve analysis for methylation status of MLH1 was significant (p = .0275) with an area under the curve of 61.1%, a sensitivity of 22.2% and a specificity of 100.0%. This pilot study indicates oligozoospermic patients have more methylation of MLH1 than normozoospermic patients. Whether hypermethylation of the MLH1 promoter plays a role in repairing relevant mismatches of sperm DNA strands in idiopathic oligozoospermia warrants further investigation.
  • Thumbnail Image
    Item
    Calibration of redox potential in sperm wash media and evaluation of oxidation–reduction potential values in various assisted reproductive technology culture media using MiOXSYS system
    (Wiley, 2018) Panner Selvam, M. K.; Henkel, Ralf; Sharma, Rajan; Agarwal, A.
    Oxidation–reduction potential describes the balance between the oxidants and antioxidants in fluids including semen. Various artificial culture media are used in andrology and IVF laboratories for sperm preparation and to support the development of fertilized oocytes under in vitro conditions. The composition and conditions of these media are vital for optimal functioning of the gametes. Currently, there are no data on the status of redox potential of sperm processing and assisted reproduction media. The purpose of this study was to compare the oxidation–reduction potential values of the different media and to calibrate the oxidation–reduction potential values of the sperm wash medium using oxidative stress inducer cumene hydroperoxide and antioxidant ascorbic acid. Redox potential was measured in 10 different media ranging from sperm wash media, freezing media and assisted reproductive technology one-step medium to sequential media. Oxidation–reduction potential values of the sequential culture medium and one-step culture medium were lower and significantly different (p < 0.05) from the sperm wash media. Calibration of the sperm wash media using the oxidant cumene hydroperoxide and antioxidant ascorbic acid demonstrated that oxidation–reduction potential and the concentration of oxidant or antioxidant are logarithmically dependent. This study highlights the importance of calibrating the oxidation–reduction potential levels of the sperm wash media in order to utilize it as a reference value to identify the physiological range of oxidation oxidation–reduction potential that does not have any adverse effect on normal physiological sperm function.
  • Thumbnail Image
    Item
    Causes and consequences of sperm mitochondrial dysfunction
    (Wiley-Blackwell, 2020) Durairajanayagam, D.; Singh, D.; Agarwal, A.; Henkel, R.
    Mitochondria have multiple functions, including synthesis of adenine triphosphate, production of reactive oxygen species, calcium signalling, thermogenesis and apoptosis. Mitochondria have a significant contribution in regulating the various physiological aspects of reproductive function, from spermatogenesis up to fertilisation. Mitochondrial functionality and intact mitochondrial membrane potential are a prerequisite for sperm motility, hyperactivation, capacitation, acrosin activity, acrosome reaction and DNA integrity. Optimal mitochondrial activity is therefore crucial for human sperm function and semen quality. However, the precise role of mitochondria in spermatozoa remains to be fully explored. Defects in sperm mitochondrial function severely impair the maintenance of energy production required for sperm motility and may be an underlying cause of asthenozoospermia. Sperm mtDNA is susceptible to oxidative damage and mutations that could compromise sperm function leading to infertility. Males with abnormal semen parameters have increased mtDNA copy number and reduced mtDNA integrity. This review discusses the role of mitochondria in sperm function, along with the causes and impact of its dysfunction on male fertility. Greater understanding of sperm mitochondrial function and its correlation with sperm quality could provide further insights into their contribution in the assessment of the infertile male.
  • Thumbnail Image
    Item
    Determination of seminal oxidation–reduction potential (ORP) as an easy and cost-effective clinical marker of male infertility
    (Wiley, 2017) Agarwal, A.; Henkel, Ralf; Sharma, Rajan; Tadros, N.N.; Sabanegh, E.
    Oxidative stress (OS) is an important contributing factor to male infertility. While previous methods to measure seminal OS are time-consuming and limited to the use of freshly produced semen, oxidation reduction potential (ORP) is easier and quicker to perform and can also be used in frozen semen. Therefore, this study evaluated the clinical utility of ORP as a potential marker of male infertility. ORP was measured in semen samples from 293 patients and 15 fertile controls and categorised according to WHO criteria as normozoospermic, oligozoospermic, asthenozoospermic, teratozoospermic and oligoasthenoteratozoospermic. Receiver operating characteristic (ROC) curves were generated to differentiate these categories. Semen parameters were significantly different when subjects were grouped as control and patients or between the patient and normozoospermic group for concentration and morphology. ORP levels were significantly different between the control and normozoospermic group. When subjects were grouped based on concentration, motility, morphology or a combination of these, the area under the ROC curve, sensitivity, specificity, positive predictive value and cut-off values were significantly different. These differences were significant when combined with ORP and grouped with any two sperm abnormalities. In conclusion, ORP is a quick, easy, cost-effective and reliable marker of semen quality as well as oxidative stress for use in a clinical setting.
  • Thumbnail Image
    Item
    Evaluation of reference values of standard semen parameters in fertile Egyptian men
    (Wiley, 2018) Zedan, H.; Ismail, S.; Gomaa, A.; Saleh, R.; Henkel, Ralf; Agarwal, A.
    The reference values of human semen, published in the WHO’s latest edition in 2010, were lower than those previously reported. The objective of this study was to evaluate reference values of standard semen parameters in fertile Egyptian men. This cross-sectional study included 240 fertile men. Men were considered fertile when their wives had recent spontaneous pregnancies with time to pregnancy (TTP) ≤12 months. The mean age of fertile men was 33.8 ± 0.5 years (range 20–55 years). The 5th percentiles (95% confidence interval) of macroscopic semen parameters were 1.5 ml for volume and 7.2 for pH. The 5th percentiles of microscopic parameters were 15 million/ ml for sperm concentration, 30 million per ejaculate for total sperm count, 50% for total motility, 40% for progressive motility, 62% for vitality, 4% for normal sperm forms and 0.1 million/ml for seminal leucocyte counts. In conclusion, fertile Egyptian men had higher reference values of sperm total motility, progressive motility and vitality, and lower reference values for total sperm counts as compared to those determined by the latest edition of the WHO laboratory manual in 2010. Other semen parameters were identical to those defined by the WHO 2010 manual.
  • Thumbnail Image
    Item
    Human sperm handling in intracytoplasmic sperm injection processes: In vitro studies on mouse oocyte activation, embryo development competence and sperm oxidation–reduction potential
    (Wiley, 2018) Roychoudhury, S.; Maldonado-Rosas, I.; Agarwal, A.; Esteves, S.C.; Henkel, Ralf; Sharma, Rajan
    Polyvinylpyrrolidone (PVP) and hyaluronic acid (HA) are routinely used in handling spermatozoa for intracytoplasmic sperm injection (ICSI). As there are still concerns about possible adverse effects on the embryo, this study investigated sperm handling in a mouse ICSI model to (i) evaluate oocyte activation after injection of spermatozoa selected for rotational or linear motion in PVP; (ii) assess the effect of sperm selection in PVP, HA and medium on oocyte activation; (iii) examine the effects of PVP and HA on parthenogenetic oocyte activation and embryo development; and (iv) assess the oxidation–reduction potential (ORP) of spermatozoa exposed to PVP, HA or medium. Oocyte activation was higher when spermatozoa exhibited rotational motion rather than linear motion (79% vs. 52%; p = .05). There was no difference in oocyte activation and embryo development after parthenogenetic oocyte activation after sperm injection using PVP, HA or medium-incubated spermatozoa. PVP-selected spermatozoa exhibited lower (p < .0001) ORP levels than using HA. Thus, results indicate that the sperm handling method and the type of medium used impact ICSI outcomes. Overall, sperm incubation in PVP, HA and medium yields similar outcomes with regard to oocyte activation and embryo development. However, PVP provides more antioxidative protection than HA and should therefore be preferred for sperm manipulation.
  • Thumbnail Image
    Item
    In Silico Sperm Proteome Analysis to Investigate DNA Repair Mechanisms in Varicocele Patients
    (Frontiers Media S.A., 2021-12-17) Henkel, Ralf; Finelli, R; Darbandi, S; Pushparaj, P. N.; Ko, E.; Agarwal, A.
    Varicocele, a condition associated with increased oxidative stress, negatively affects sperm DNA integrity and reduces pregnancy rates. However, the molecular mechanisms related to DNA integrity, damage, and repair in varicocele patients remain unclear. This study aimed to determine the role of DNA repair molecular mechanisms in varicocele-related infertility by combining an in silico proteomics approach with wet-laboratory techniques. Proteomics results previously generated from varicocele patients (n=50) and fertile controls (n=10) attending our Andrology Center were reanalyzed using bioinformatics tools, including the WEB-based Gene SeT AnaLysis Toolkit, Open Target Platform, and Ingenuity Pathway Analysis (IPA), to identify differentially expressed proteins (DEPs) involved in DNA repair. Subsequently, selected DEPs in spermatozoa were validated using western blotting in varicocele (n = 13) and fertile control (n = 5) samples. We identified 99 DEPs mainly involved in male reproductive system disease (n=66) and male infertility (n=47). IPA analysis identified five proteins [fatty acid synthase (FASN), myeloperoxidase (MPO), mitochondrial aconitate hydratase (ACO2), nucleoporin 93 (NUP93), and 26S proteasome non-ATPase regulatory subunit 14 (PSMD14)] associated with DNA repair deficiency, which showed altered expression in varicocele (P <0.03). We validated ACO2 downregulation (fold change=0.37, change%=-62.7%, P=0.0001) and FASN overexpression (fold change = 4.04, change %= 303.7%, P = 0.014) in men with varicocele compared to controls. This study combined a unique in silico approach with an in vitro validation of the molecular mechanisms that may be responsible for varicocele-associated infertility. We identified ACO2 and FASN as possible proteins involved in DNA repair, whose altered expression may contribute to DNA damage in varicocele pathophysiology. Copyright © 2021