scholarly journals Diagnosis and Treatment of Male Infertility-Related Fertilization Failure

2020 ◽  
Vol 9 (12) ◽  
pp. 3899
Author(s):  
Arantxa Cardona Barberán ◽  
Annekatrien Boel ◽  
Frauke Vanden Meerschaut ◽  
Dominic Stoop ◽  
Björn Heindryckx
Keyword(s):  
Male Infertility ◽  
Current Knowledge ◽  
Oocyte Activation ◽  
Fertilization Failure ◽  
Sperm Abnormalities ◽  
Normal Sperm ◽  
Activation Mechanisms ◽  
Sperm Factor ◽  
Male Factors ◽  
Assisted Oocyte Activation

Infertility affects approximately 15% of reproductive-aged couples worldwide, of which up to 30% of the cases are caused by male factors alone. The origin of male infertility is mostly attributed to sperm abnormalities, of which many are caused by genetic defects. The development of intracytoplasmic sperm injection (ICSI) has helped to circumvent most male infertility conditions. However, there is still a challenging group of infertile males whose sperm, although having normal sperm parameters, are unable to activate the oocyte, even after ICSI treatment. While ICSI generally allows fertilization rates of 70 to 80%, total fertilization failure (FF) still occurs in 1 to 3% of ICSI cycles. Phospholipase C zeta (PLCζ) has been demonstrated to be a critical sperm oocyte activating factor (SOAF) and the absence, reduced, or altered forms of PLCζ have been shown to cause male infertility-related FF. The purpose of this review is to (i) summarize the current knowledge on PLCζ as the critical sperm factor for successful fertilization, as well as to discuss the existence of alternative sperm-induced oocyte activation mechanisms, (ii) describe the diagnostic tests available to determine the cause of FF, and (iii) summarize the beneficial effect of assisted oocyte activation (AOA) to overcome FF.

P–568 Homozygous Pathogenic Variants in ACTL9 Cause Fertilization Failure and Male Infertility in Human and Mouse

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
J Dai ◽  
T Zhang ◽  
J Guo ◽  
Q Zhou ◽  
Y Gu ◽  
...  
Keyword(s):  
Mouse Model ◽  
Male Infertility ◽  
Therapeutic Option ◽  
Calcium Ionophore ◽  
Calcium Oscillations ◽  
Oocyte Activation ◽  
Fertilization Failure ◽  
Pathogenic Variants ◽  
Male Factors ◽  
Poor Fertilization

Abstract Study question What are the other male factors that cause total fertilization failure (TFF) excepting for variants in PLCZ1? Summary answer Homozygous variants in ACTL9 (actin like 9) cause abnormal localization of PLCζ in a loosened perinuclear theca (PT) structure and leads to TFF. What is known already In previous studies, investigators have reported that the female factors in TFF after intracytoplasmic sperm injection (ICSI) include pathogenic variants in WEE2, TLE6, and TUBB8, whereas for male factors, pathogenic variants in PLCZ1 were reported to be the primary cause of TFF, which account for approximately 30% of couples with male factors in TFF excluding globozoospermia. Most recently, it was reported that pathogenic variants in ACTL7A led to reduced expression and abnormal localization of PLCζ, thereby identifying this genetic variant as a potential cause of TFF. Study design, size, duration Fifty-four infertile couples with TFF or poor fertilization (fertilization rate of < 20%) at the Reproductive and Genetic Hospital of CITIC-Xiangya during January 2014 to June 2020 were recruited into this study. Participants/materials, setting, methods Male factors were identified in (MOAT). WES analysis was used to analyze the genetic factors of individuals with male factors. Sperm morphological study was conducted by H&E staining and TEM. Immunostaining of PLCζ was used to analyze the status of sperm-borne activation factor. A knock-in mouse model was generated by CRISPER-Cas9 technology. Sperm from homozygous Actl9 variant mice were analyzed by TEM and ICSI. ICSI with AOA was performed in couples with ACTL9 variants. Main results and the role of chance A total of 54 couples with TFF or poor fertilization were screened, with 21 couples determined to have a male infertility factor by MOAT. Whole-exome sequencing of these 21 male individuals identified three homozygous pathogenic variants in ACTL9 in three individuals. ACTL9 variations led to abnormal ultrastructure of the PT, with PLCζ absent in the head and present in the neck of the mutant sperm, which contributed to failed normal calcium oscillations in oocytes and subsequent TFF. The key roles of ACTL9 in the PT structure and TFF after ICSI were further confirmed in Actl9-mutated mouse model. Furthermore, assisted oocyte activation by calcium ionophore exposure successfully overcame TFF and achieved live births in a couple with an ACTL9 variant. Limitations, reasons for caution The mechanism of how ACTL9 regulate PLCζ remains unknown. Wider implications of the findings: It provided a genetic marker and a therapeutic option for individuals who have undergone ICSI without successful fertilization. Trial registration number not applioable

P–214 Effect of artificial activation of oocytes (AOA-ICSI) on the ploidy status of the resultant blastocysts. A sibling-oocytes pilot study

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
E Seo. Pe. Yin
Keyword(s):  
Pilot Study ◽  
Fertilization Rate ◽  
Control Group ◽  
Oocyte Activation ◽  
Fertilization Failure ◽  
Factor Deficiency ◽  
Sperm Factor ◽  
Blastocyst Rate ◽  
Artificial Activation ◽  
Ploidy Status

Abstract Study question Will artificial activation of oocytes alter the ploidy status of the resultant blastocysts? A sibling-oocytes pilot study Summary answer AOA-ICSI does not increase the risk of having aneuploidy blastocysts and can improve the fertilization rate in patients with sperm factor deficiency. What is known already Despite introducing ICSI as an aid to improve chances of fertilization, fertilization failure can still occur in 2–3% of ICSI cycles. Fertilization is a complex process triggered by a cascade of events following calcium (Ca2+) oscillations. Evidence suggests that the deficiency, localization or altered structure of the sperm-derived protein PLCζ in oocyte activation may be a reason for meiotic II arrest in the oocyte. Artificial oocyte activation has been proposed to compensate for the lack of calcium oscillation and resumes meiotic progression. There are however insufficient studies to determine its effect on the chromosomal status of the resultant blastocysts. Study design, size, duration This is a prospective, randomized study conducted at our Center from August-October 2020. A total of 20 couples intended for ICSI + Preimplatation Genetic Testing for Aneuploidy (PGT-A) cycles were recruited based on fulfilling one of the following criteria: 1) previous total fertilization failure (TFF), 2) history of low fertilization rate (<30%), 3) more than 2 cycles of failed IVF cycles (no implantation) 4) poor embryo development (no blastocysts formed) and 5) severe male factor. Participants/materials, setting, methods A total of 231 MII oocytes underwent randomization in a 1:1 ratio between AOA-ICSI and control group. All oocytes are subjected to ICSI treatment. Oocytes in the AOA-ICSI group are treated in 25μl droplets 10μM ready to use bicarbonate buffered calcium ionophore (Kitazato, Japan) for 15 minutes post-ICSI. The blastocysts were biopsied and subjected to PGT-A. Primary outcome was the aneuploidy rate and secondary outcomes were fertilization rate and blastocyst rate. Main results and the role of chance There were 11 out of 40 (27.5%) aneuploid blastocysts in the AOA-ICSI group and 7 out of 23 aneuploid blastocysts (30.4%) in the control group [odds ratio (OR) = 0.87; 95% confidence interval (CI) 0.28–2.68, p = 0.8040). There was no statistically significant difference between both groups. However, fertilization rate of the AOA- ICSI group was significantly higher than the fertilization rate in the control group (68.6% vs 49.6% respectively, OR = 2.22; 95% CI, 1.31–3.81, p = 0.0034). There were 40 blastocysts formed in the AOA-ICSI group and 23 blastocysts formed in the control group. It was found that the AOA-ICSI group yielded a higher blastocyst rate (49.4%) compared to the control group (41.1%) (OR = 1.40; 95% CI, 0.71 to 2.78, p = 0.3379) but the difference was not statistically significant. Limitations, reasons for caution The possibility of TE cells biopsied may not be representative of the whole blastocyst makes it possible to have false clinical data. The dosage and time were also not evaluated in this study as exposure time was found to be a critical factor of fertilization rate in a previous study. Wider implications of the findings: This study showed that AOA-ICSI does not increase the risk of having aneuploidy blastocysts and can improve the fertilization rate in patients with sperm factor deficiency. Additional studies involving a larger number of patients with more specific indication can further justify the benefits of AOA as a therapeutic application. Trial registration number NA

scholarly journals Comparative study of preimplantation development following distinct assisted oocyte activation protocols in a PLC-zeta knockout mouse model

2020 ◽  
Vol 26 (11) ◽  
pp. 801-815 ◽  
Author(s):  
M Ferrer-Buitrago ◽  
L Tilleman ◽  
V Thys ◽  
A Hachem ◽  
A Boel ◽  
...  
Keyword(s):  
Independent Effect ◽  
Control Group ◽  
Oocyte Activation ◽  
Blastocyst Development ◽  
Knockout Mouse Model ◽  
Transcription Profiles ◽  
Sperm Factor ◽  
Activation Rates ◽  
Assisted Oocyte Activation

Abstract Mammalian fertilization encompasses a series of Ca2+ oscillations initiated by the sperm factor phospholipase C zeta (PLCζ). Some studies have shown that altering the Ca2+ oscillatory regime at fertilization affects preimplantation blastocyst development. However, assisted oocyte activation (AOA) protocols can induce oocyte activation in a manner that diverges profoundly from the physiological Ca2+ profiling. In our study, we used the newly developed PLCζ-null sperm to investigate the independent effect of AOA on mouse preimplantation embryogenesis. Based on previous findings, we hypothesized that AOA protocols with Ca2+ oscillatory responses might improve blastocyst formation rates and differing Ca2+ profiles might alter blastocyst transcriptomes. A total of 326 MII B6D2F1-oocytes were used to describe Ca2+ profiles and to compare embryonic development and individual blastocyst transcriptomes between four control conditions: C1 (in-vivo fertilization), C2 (ICSI control sperm), C3 (parthenogenesis) and C4 (ICSI-PLCζ-KO sperm) and four AOA groups: AOA1 (human recombinant PLCζ), AOA2 (Sr2+), AOA3 (ionomycin) and AOA4 (TPEN). All groups revealed remarkable variations in their Ca2+ profiles; however, oocyte activation rates were comparable between the controls (91.1% ± 13.8%) and AOA (86.9% ± 11.1%) groups. AOA methods which enable Ca2+ oscillatory responses (AOA1: 41% and AOA2: 75%) or single Ca2+ transients (AOA3: 50%) showed no significantly different blastocyst rates compared to ICSI control group (C2: 70%). In contrast, we observed a significant decrease in compaction (53% vs. 83%) and blastocyst rates (41% vs. 70%) in the absence of an initial Ca2+ trigger (AOA4) compared with the C2 group. Transcription profiles did not identify significant differences in gene expression levels between the ICSI control group (C2) and the four AOA groups.

scholarly journals Assisted oocyte activation following ICSI fertilization failure

2014 ◽  
Vol 28 (5) ◽  
pp. 560-571 ◽  
Author(s):  
Frauke Vanden Meerschaut ◽  
Dimitra Nikiforaki ◽  
Björn Heindryckx ◽  
Petra De Sutter
Keyword(s):  
Oocyte Activation ◽  
Fertilization Failure ◽  
Assisted Oocyte Activation

scholarly journals Assisted oocyte activation overcomes fertilization failure in globozoospermic patients regardless of the DPY19L2 status

2013 ◽  
Vol 28 (4) ◽  
pp. 1054-1061 ◽  
Author(s):  
P. Kuentz ◽  
F. Vanden Meerschaut ◽  
E. ElInati ◽  
M. H. Nasr-Esfahani ◽  
T. Gurgan ◽  
...  
Keyword(s):  
Oocyte Activation ◽  
Fertilization Failure ◽  
Assisted Oocyte Activation

Effect of two assisted oocyte activation protocols used to overcome fertilization failure on the activation potential and calcium releasing pattern

2016 ◽  
Vol 105 (3) ◽  
pp. 798-806.e2 ◽  
Author(s):  
Dimitra Nikiforaki ◽  
Frauke Vanden Meerschaut ◽  
Chloë de Roo ◽  
Yuechao Lu ◽  
Minerva Ferrer-Buitrago ◽  
...  
Keyword(s):  
Oocyte Activation ◽  
Fertilization Failure ◽  
Activation Potential ◽  
Assisted Oocyte Activation

Novel mutations in PLCZ1 cause male infertility due to fertilization failure or poor fertilization

2020 ◽  
Vol 35 (2) ◽  
pp. 472-481 ◽  
Author(s):  
Zheng Yan ◽  
Yong Fan ◽  
Fei Wang ◽  
Zhiguang Yan ◽  
Menghui Li ◽  
...  
Keyword(s):  
Male Infertility ◽  
Conflicts Of Interest ◽  
Missense Mutations ◽  
Oocyte Activation ◽  
Fertilization Failure ◽  
Novel Mutations ◽  
Primary Infertility ◽  
Human Fertilization ◽  
Poor Fertilization

Abstract STUDY QUESTION Do sperm-specific phospholipase C zeta (PLCZ1) mutations account for male infertility due to fertilization failure? SUMMARY ANSWER Six novel mutations and one reported mutation in PLCZ1 were identified in five of 14 independent families characterized by fertilization failure or poor fertilization, suggesting that these mutations may be responsible for fertilization failure in men exhibiting primary infertility. WHAT IS KNOWN ALREADY PLCZ1 is essential for the induction of intracellular calcium (Ca2+) oscillations and the initiation of oocyte activation during mammalian fertilization. However, genetic evidence linking PLCZ1 mutations with male infertility remains limited. STUDY DESIGN, SIZE, DURATION Fourteen unrelated primary infertility patients were recruited into this study from January 2016 to December 2018; the patients exhibited total fertilization failure or poor fertilization, as evidenced by ICSI and sperm-related oocyte activation deficiencies identified in mouse oocyte activation assays. PARTICIPANTS/MATERIALS, SETTING, METHODS Genomic DNA samples were extracted from the peripheral blood of patients. The whole exons of PLCZ1 were sequenced by Sanger sequencing. The PLCZ1 sequences were aligned by CodonCode software to identify rare variants. The ExAC database was used to search for the frequency of corresponding mutations. The pathogenicity of identified variants and their possible effects on the protein were assessed in silico. PLCZ1 protein levels in semen samples were evaluated by western blotting. Oocyte activation ability was assessed by the injection of wild-type and mutant PLCZ1 cRNAs into human mature metaphase II (MII) oocytes in vitro. MAIN RESULTS AND THE ROLE OF CHANCE We identified six novel mutations and one reported mutation in PLCZ1 among five affected individuals. In addition to four novel missense mutations, two new types of genetic variants were identified, including one in-frame deletion and one splicing mutation. Western blot analysis revealed that PLCZ1 protein expression was not observed in the semen samples from the five affected patients. Microinjection with the PLCZ1 cRNA variants was performed, and a significant decrease in the percentage of pronuclei was observed for four novel missense mutations and one novel in-frame deletion mutation, suggesting that these mutations have a deleterious influence on protein function. By artificial oocyte activation treatment, the fertilization failure phenotypes of four affected patients were successfully rescued and three healthy babies were delivered. LARGE SCALE DATA N/A LIMITATIONS, REASONS FOR CAUTION We screened only the whole exons of PLCZ1. Additional possible mutations in the non-coding region of PLCZ1 should be further studied. WIDER IMPLICATIONS OF THE FINDINGS Our study not only further confirms the important role of PLCZ1 in human fertilization but also expands the mutational spectrum of PLCZ1 associated with male infertility, which provides a basis for assessing genetic variation in PLCZ1 as a potential diagnostic marker for infertile men suffering from fertilization failure. STUDY FUNDING/COMPETING INTEREST(S) This research was supported by the National Natural Foundation of China (81 571 486 and 81 771 649). All authors have no conflicts of interest to declare.

scholarly journals A Novel Assisted Oocyte Activation Method Improves Fertilization in Patients With Recurrent Fertilization Failure

2021 ◽  
Vol 9 ◽  
Author(s):  
Meng Wang ◽  
Lixia Zhu ◽  
Chang Liu ◽  
Hui He ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Normal Distribution ◽  
Intracytoplasmic Sperm Injection ◽  
Fertilization Rate ◽  
The Novel ◽  
Oocyte Activation ◽  
Fertilization Failure ◽  
Activation Factor ◽  
Total Fertilization Failure ◽  
Signaling Activation ◽  
Assisted Oocyte Activation

Total fertilization failure (TFF) occurs in 1–3% of total intracytoplasmic sperm injection (ICSI) cycles and can reoccur in subsequent cycles. Despite the high success rate with the application of assisted oocyte activation (AOA), there is still a small number of couples who cannot obtain fertilized eggs after conventional calcium (Ca2+) ionophores-based ICSI-AOA. Six couples experiencing repeated TFF or low fertilization (<10%) after ICSI and conventional ICSI-AOA were enrolled in this study. Compared with the regular ICSI group and the conventional ICSI-AOA group, the new AOA method, a combination of cycloheximide (CHX) and ionomycin, can significantly increase the fertilization rate from less than 10 up to approximately 50% in most cases. The normal distribution of sperm-related oocyte activation factor phospholipase C zeta (PLCζ1) in the sperms of the cases indicated the absence of an aberrant Ca2+ signaling activation. The results of the whole-embryo aneuploidies analysis indicated that oocytes receiving the novel AOA treatment had the potential to develop into blastocysts with normal karyotypes. Our data demonstrated that CHX combined with ionomycin was able to effectively improve the fertilization rate in the majority of patients suffering from TFF. This novel AOA method had a potential therapeutic effect on those couples experiencing TFF, even after conventional AOA, which may surmount the severe fertilization deficiencies in patients with a repeated low fertilization or TFF.

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