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result(s) for
"Virant Klun, Irma"
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The role of anti-Müllerian hormone (AMH) in ovarian disease and infertility
by
Virant-Klun Irma
,
Bedenk Jure
,
Eda, Vrtačnik-Bokal
in
Biomarkers
,
In vitro fertilization
,
Infertility
2020
PurposeIn this review, the current knowledge on anti-Müllerian hormone (AMH) is presented, concerning its value in disease and IVF treatment as well as in terms of its prospective clinical use.MethodsAMH is becoming the most appropriate biomarker for the ovarian reserve measured predominantly for assisted reproductive treatment (ART) patients in comparison to the currently used antral follicle count (AFC). However, this is not the only way AMH measurements can be used in the clinics. Because of this, we reviewed the current literature for the use of AMH in current or prospective clinical practice.ResultsWe found that AMH has a high predictive value in assessing the ovarian reserve, which can lead to a better efficiency of in vitro fertilization (IVF) procedures. It has a high potential to be developed as a staple diagnostic marker of ovarian disease, especially for ovarian cancers and even as a possible treatment tool for certain cancers. It could potentially be used to prevent oocyte loss due to chemo- or radiotherapy.ConclusionAMH is an important hormone especially in women reproductive organs and is currently seen as the best biomarker for a multitude of uses in reproductive medicine. Currently, the biggest issue lies in the lack of international standardization of AMH. However, it is encouraging to see that there is interest in AMH in the form of research on its action and use in reproductive medicine.
Journal Article
Recombinant anti-Müllerian hormone in the maturation medium improves the in vitro maturation of human immature (GV) oocytes after controlled ovarian hormonal stimulation
by
Železnik Ramuta, Taja
,
Vrtačnik Bokal, Eda
,
Režen, Tadeja
in
Anti-Müllerian hormone
,
Anti-Müllerian hormone receptor 2
,
Confocal microscopy
2022
Background
In vitro maturation (IVM) of oocytes is a laboratory method that allows the maturation of immature (GV) oocytes retrieved from patients enrolled in the in vitro fertilization (IVF) programme. However, this method is still sparsely researched and used in clinical practice, leading to suboptimal clinical results. Anti-Müllerian hormone (AMH) is an important hormone with known effects on human ovaries, especially on follicles (follicular cells) during folliculogenesis. In contrast, the effect of AMH on the human oocyte itself is unknown. Therefore, we wanted to determine whether human oocytes express AMH receptor 2 (AMHR2) for this hormone. Recombinant AMH was added to the IVM medium to determine whether it affected oocyte maturation.
Methods
In total, 247 human oocytes (171 immature and 76 mature) were collected from patients enrolled in the intracytoplasmic sperm injection (ICSI) programme who were aged 20 to 43 years and underwent a short antagonist protocol of ovarian stimulation. The expression of AMHR2 protein and
AMHR2
gene was analysed in immature and mature oocytes. Additionally, maturation of GV oocytes was performed in vitro in different maturation media with or without added AMH to evaluate the effect of AMH on the oocyte maturation rate.
Results
Immunocytochemistry and confocal microscopy revealed that AMHR2 protein is expressed in both immature and mature human oocytes. AMHR2 was expressed in a spotted pattern throughout the whole oocyte. The IVM procedure revealed that AMH in maturation medium improved GV oocyte maturation in vitro, as all oocytes were successfully matured in maturation medium containing recombinant AMH only. Furthermore, antagonism between AMH and follicle-stimulating hormone (FSH) during the maturation process was observed, with fewer oocytes maturing when both AMH and FSH were added to the maturation medium. Finally,
AMHR2
gene expression was found in immature and in vitro matured oocytes but absent in mature oocytes.
Conclusions
The positive AMHR2 protein and
AMHR2
gene expression in human oocytes shows that AMH could directly act on human oocytes. This was further functionally confirmed by the IVM procedure. These findings suggest the potential clinical application of recombinant AMH to improve IVM of human oocytes in the future.
Journal Article
Effect of the oral intake of astaxanthin on semen parameters in patients with oligo-astheno-teratozoospermia: a randomized double-blind placebo-controlled trial
by
Pinter, Bojana
,
Klun, Irma Virant
,
Kumalic, Senka Imamovic
in
antioxidant
,
Antioxidants
,
Astaxanthin
2020
Background Higher concentrations of seminal reactive oxygen species may be related to male infertility. Astaxanthin with high antioxidant activity can have an impact on the prevention and treatment of various health conditions, including cancer. However, efficacy studies on astaxanthin in patients with oligospermia with/without astheno- or teratozoospermia (O±A±T) have not yet been reported. Our aim was to evaluate the effect of the oral intake of astaxanthin on semen parameters. Patients and methods In a randomized double-blind trial, 80 men with O±A±T were allocated to intervention with 16 mg astaxanthin orally daily or placebo. At baseline and after three months basic semen parameters, sperm deoxyribonucleic acid (DNA) fragmentation and mitochondrial membrane potential (MMP) of spermatozoa and serum follicle-stimulating hormone (FSH) value were measured. Results Analysis of the results of 72 patients completing the study (37 in the study group, 35 in the placebo group) did not show any statistically significant change, in the astaxanthin group no improvements in the total number of spermatozoa, concentration of spermatozoa, total motility of spermatozoa, morphology of spermatozoa, DNA fragmentation and mitochondrial membrane potential of spermatozoa or serum FSH were determined. In the placebo group, statistically significant changes in the total number and concentration of spermatozoa were determined. Conclusions The oral intake of astaxanthin did not affect any semen parameters in patients with O±A±T.
Journal Article
Vitrification Using Soy Lecithin and Sucrose: A New Way to Store the Sperm for the Preservation of Canine Reproductive Function
by
Zakošek Pipan, Maja
,
Virant Klun, Irma
,
Casal, Margret L.
in
canine
,
citric acid
,
Cryopreservation
2020
A challenge in freezing semen for short and long-term availability is avoiding damage to intact spermatozoa caused by the freezing process. Vitrification protocols provide better results through less manipulation of semen and shorter freezing time compared to slow freezing techniques. Our research was aimed at improving vitrification methods for canine semen. Semen quality was determined in 20 ejaculates after collection. Each ejaculate was divided into eight aliquots, each with a different extender. The control extender contained TRIS, citric acid, fructose, and antibiotics. Soy lecithin and sucrose were added to the control extender at different concentrations to make up the test extenders and final concentration of 50 × 106 spermatozoa/mL. From each group, a 33 µL (1.65 × 106 spermatozoa) suspension of spermatozoa was dropped directly into liquid nitrogen and devitrified at least one week later and evaluated as before. Soy lecithin at 1% and 0.25 M sucrose added to the base vitrification media effectively preserved all sperm qualities. Our results demonstrate the effectiveness of our methods. Vitrification media containing sucrose and soy lecithin cause a minimal decline in quality of canine semen after devitrification. Furthermore, extenders used in our research did not contain egg yolk, which was replaced by soy lecithin, thus allowing for ease of shipping to other countries with strict requirements.
Journal Article
Cumulus Cells Gene Expression Profiling in Terms of Oocyte Maturity in Controlled Ovarian Hyperstimulation Using GnRH Agonist or GnRH Antagonist
2012
In in vitro fertilization (IVF) cycles controlled ovarian hyperstimulation (COH) is established by gonadotropins in combination with gonadotropin-releasing hormone (GnRH) agonists or antagonists, to prevent premature luteinizing hormone (LH) surge. The aim of our study was to improve the understanding of gene expression profile of cumulus cells (CC) in terms of ovarian stimulation protocol and oocyte maturity. We applied Affymetrix gene expression profiling in CC of oocytes at different maturation stages using either GnRH agonists or GnRH antagonists. Two analyses were performed: the first involved CC of immature metaphase I (MI) and mature metaphase II (MII) oocytes where 359 genes were differentially expressed, and the second involved the two GnRH analogues where no differentially expressed genes were observed at the entire transcriptome level. A further analysis of 359 differentially genes was performed, focusing on anti-Müllerian hormone receptor 2 (AMHR2), follicle stimulating hormone receptor (FSHR), vascular endothelial growth factor C (VEGFC) and serine protease inhibitor E2 (SERPINE2). Among other differentially expressed genes we observed a marked number of new genes connected to cell adhesion and neurotransmitters such as dopamine, glycine and γ-Aminobutyric acid (GABA). No differential expression in CC between the two GnRH analogues supports the findings of clinical studies where no significant difference in live birth rates between both GnRH analogues has been proven.
Journal Article
From Oxidative Stress to Male Infertility: Review of the Associations of Endocrine-Disrupting Chemicals (Bisphenols, Phthalates, and Parabens) with Human Semen Quality
by
Imamovic-Kumalic, Senka
,
Pinter, Bojana
,
Virant-Klun, Irma
in
Apoptosis
,
Bisphenol A
,
Breast cancer
2022
Exposure to endocrine-disrupting chemicals (EDCs) may result in oxidative stress and endocrine system disturbance, which can have an impact on human reproduction and development. In male reproductive health, EDCs have been related to impaired reproductive function and male infertility, altered fetal development, and testicular germ-cell, prostate, and breast cancers. We conducted an electronic search using PubMed on endocrine disruptors related to oxidative stress and male infertility, and evaluated their association with endocrine-disrupting chemicals (bisphenols, phthalates, and parabens) in 25 articles. Higher levels of urinary bisphenols showed correlation with impaired semen quality and increased DNA damage. Considering phthalates and their metabolites, all studies found a positive association between urinary levels of phthalates and at least one semen parameter indicative of low semen quality; some studies also revealed sperm DNA damage. The studies on parabens less often revealed correlation of urinary parabens concentrations with a decrease in sperm count, as well as motility and DNA damage. Moreover, EDCs can elevate ROS production and lipid peroxidation, increase apoptosis, induce epigenetic modifications, and change the Y:X sperm chromosome ratio and sperm protein composition. Our review revealed detrimental effects of EDCs on semen quality and sperm DNA integrity—especially in BPA and phthalates, but also in parabens.
Journal Article
Polycystic Ovary Syndrome and Endocrine Disruptors (Bisphenols, Parabens, and Triclosan)—A Systematic Review
by
Pinter, Bojana
,
Srnovršnik, Tinkara
,
Virant-Klun, Irma
in
Androgens
,
Androstenedione
,
Bilirubin
2023
Exposure to endocrine disrupting chemicals (EDCs) can result in alterations of the female reproductive system, including polycystic ovary syndrome (PCOS). The aim of this review was to summarize the knowledge about the association of EDCs (bisphenols, parabens, and triclosan) with PCOS. We conducted an electronic literature search using PubMed for studies published between January 2007 and October 2022 on EDCs related to PCOS, and evaluated the association of PCOS with bisphenols, parabens and triclosan in 15 articles. Most studies revealed significantly higher plasma, urinary or follicular fluid levels of bisphenol A (BPA) in women with PCOS, and some showed a positive correlation of BPA with insulin resistance, polycystic morphology on ultrasound, hepatic steatosis, bilirubin levels, as well as free androgen index, androstenedione and testosterone serum levels, and markers of low-grade chronic inflammation. There was a negative correlation of BPA with markers of ovarian reserve, sex hormone binding globulin and vitamin D–binding protein. Parabens and triclosan have been studied in only one study each, with no significant associations with PCOS observed. Our review revealed an association of BPA with PCOS and negative effects of BPA on human ovaries; more research is needed to assess the potential associations of parabens and triclosan with PCOS.
Journal Article
Endocrine disrupting chemicals and obesity prevention: scoping review
by
Kek, Tina
,
Klun, Irma Virant
,
Amon, Mojca
in
Analysis
,
Benzhydryl Compounds - adverse effects
,
Bisphenols
2024
Introduction
Exposure to endocrine disrupting chemicals (EDCs) can result in alterations of natural hormones in the body. The aim of this review article is to highlight the knowledge about EDCs and obesity.
Methods
A scoping review of the electronic literature was performed using PubMed platform for studies on EDCs and obesity published between the years 2013–2023. A total of 10 systematic reviews and meta-analysis studies met our inclusion criteria on more prominent EDCs focusing mainly on bisphenols, including parabens, triclosan, and phthalates, and their association with obesity.
Design
Scoping review.
Results
EDCs, mostly bisphenols and phthalates, are related to health effects, while there is less information on the impact of parabens and triclosan. A series of negative physiological effects involving obesogenic, diabetogenic, carcinogenic, and inflammatory mechanisms as well as epigenetic and microbiota modulations was related to a prolonged EDCs exposure. A more profound research of particular pollutants is required to illuminate the accelerating effects of particular EDCs, mixtures or their metabolites on the mechanism of the development of obesity.
Conclusion
Considering the characteristics of EDCs and the heterogeneity of studies, it is necessary to design specific studies of effect tracking and, in particular, education about daily preventive exposure to EDCs for the preservation of long-term public health.
Journal Article
Human Oocytes Express Both ACE2 and BSG Genes and Corresponding Proteins: Is SARS-CoV-2 Infection Possible?
2021
In addition to a number of scientific and medical questions about SARS-CoV-2 infection that still need to be answered, there is also the question of how this highly virulent virus and COVID-19 disease affect gametogenesis in humans. Even more important is the question of whether the virus can also enter and infect oocytes and possibly alter them in an unknown way, which could also affect the development and status of the human embryo. The answers to these questions are still poorly known, so we reviewed the human oocyte transcriptome and proteome obtained in our previous studies and found that human oocytes from the in vitro fertilization program expressed both the ACE2 and BSG genes and the corresponding ACE2 and BSG proteins. This means that human oocytes possess the molecular ‘machinery’ to facilitate SARS-CoV-2 entrance and infection. According to various studies, especially in animal models, different viruses can infect oocytes, so infection of the oocyte with SARS-Cov-2 cannot be completely ruled out. A hypothetical model of human oocyte infection with this virus has been proposed.
Journal Article
Heavy metals and essential elements in association with oxidative stress in women with polycystic ovary syndrome-a systematic review
2023
Altered levels of heavy metals and essential elements have been associated with oxidative stress (OS) and metabolic and hormonal changes in women with polycystic ovary syndrome (PCOS). We aimed to summarize the knowledge on the association of heavy metals and essential elements with OS in PCOS. An electronic literature search using PubMed for studies published between January 2008 and April 2023 was conducted. We evaluated heavy metals and essential elements in relation to OS in PCOS in 15 articles. PCOS women had increased antimonium (Sb), cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), tellurium (Te), thallium (Tl) and osmium (Os) blood levels and decreased zinc (Zn) blood levels; the results of copper (Cu) blood levels were conflicting. Some studies showed a significant correlation between heavy metals (Sb, Cd, Pb, Hg, As, Te and Tl) and essential elements (Se, Zn, Cr, Ca, Mg and Cu) and markers of OS and chronic inflammation. Heavy metals (Sb, Cd, Pb and Hg) and essential elements (Zn, Cr, Se, Ca, Mg and Cu) were associated with metabolic and hormonal characteristics in PCOS. There might be a possible benefit from supplementation therapy in reducing OS and endocrinological problems related to PCOS. Our review confirmed an association between heavy metals and essential elements with OS in PCOS women. This systematic review is registered in PROSPERO under number CRD42023418453.
Journal Article