Reproductive biology
Abstract
Aneuploidy, a deviation from the normal chromosome copy number, is common in human embryos and is considered a primary cause of implantation failure and early pregnancy loss. Meiotic errors lead to uniformly abnormal karyotypes, while mitotic errors lead to chromosomal mosaicism: the presence of cells with at least two different karyotypes within an embryo. Knowledge about mosaicism in blastocysts mainly derives from bulk DNA sequencing of multicellular trophectoderm (TE) and/or inner cell mass (ICM) samples. However, this can only detect an average net gain or loss of DNA above a detection threshold of 20-30%. To accurately assess mosaicism, we separated the TE and ICM of 55 good quality surplus blastocysts and successfully applied single-cell whole genome sequencing (scKaryo-seq) on 1057 cells. Mosaicism involving numerical and structural chromosome abnormalities was detected in 82% of the embryos, where most abnormalities affected less than 20% of the cells. Structural abnormalities, potentially caused by replication stress and DNA damage, were observed in 69% of the embryos. In conclusion, our findings indicated that mosaicism is prevalent in good-quality blastocysts, while these blastocysts would likely be identified as normal with current bulk DNA sequencing techniques used for preimplantation genetic testing for aneuploidy (PGT-A).
Authors
Effrosyni A. Chavli, Sjoerd J. Klaasen, Diane Van Opstal, Joop S.E. Laven, Geert J.P.L. Kops, Esther B. Baart
Abstract
The infertility of many couples rests on an enigmatic dysfunction of the man’s sperm. To gain insight into the underlying pathomechanisms, we assessed the function of the sperm-specific multisubunit CatSper-channel complex in the sperm of almost 2,300 men undergoing a fertility workup, using a simple motility-based test. We identified a group of men with normal semen parameters but defective CatSper function. These men or couples failed to conceive naturally and upon medically assisted reproduction via intrauterine insemination and in vitro fertilization. Intracytoplasmic sperm injection (ICSI) was, ultimately, required to conceive a child. We revealed that the defective CatSper function was caused by variations in CATSPER genes. Moreover, we unveiled that CatSper-deficient human sperm were unable to undergo hyperactive motility and, therefore, failed to penetrate the egg coat. Thus, our study provides the experimental evidence that sperm hyperactivation is required for human fertilization, explaining the infertility of CatSper-deficient men and the need of ICSI for medically assisted reproduction. Finally, our study also revealed that defective CatSper function and ensuing failure to hyperactivate represents the most common cause of unexplained male infertility known thus far and that this sperm channelopathy can readily be diagnosed, enabling future evidence-based treatment of affected couples.
Authors
Samuel Young, Christian Schiffer, Alice Wagner, Jannika Patz, Anton Potapenko, Leonie Herrmann, Verena Nordhoff, Tim Pock, Claudia Krallmann, Birgit Stallmeyer, Albrecht Röpke, Michelina Kierzek, Cristina Biagioni, Tao Wang, Lars Haalck, Dirk Deuster, Jan N. Hansen, Dagmar Wachten, Benjamin Risse, Hermann M. Behre, Stefan Schlatt, Sabine Kliesch, Frank Tüttelmann, Christoph Brenker, Timo Strünker
Abstract
In vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are 2 major assisted reproductive techniques (ARTs) used widely to treat infertility. Recently, spermatogonial transplantation emerged as a new ART to restore fertility to young patients with cancer after cancer therapy. To examine the influence of germ cell manipulation on behavior of offspring, we produced F1 offspring by a combination of two ARTs, spermatogonial transplantation and ICSI. When these animals were compared with F1 offspring produced by ICSI using fresh wild-type sperm, not only spermatogonial transplantation–ICSI mice but also ICSI-only control mice exhibited behavioral abnormalities, which persisted in the F2 generation. Furthermore, although these F1 offspring appeared normal, F2 offspring produced by IVF using F1 sperm and wild-type oocytes showed various types of congenital abnormalities, including anophthalmia, hydrocephalus, and missing limbs. Therefore, ARTs can induce morphological and functional defects in mice, some of which become evident only after germline transmission.
Authors
Mito Kanatsu-Shinohara, Yusuke Shiromoto, Narumi Ogonuki, Kimiko Inoue, Satoko Hattori, Kento Miura, Naomi Watanabe, Ayumi Hasegawa, Keiji Mochida, Takuya Yamamoto, Tsuyoshi Miyakawa, Atsuo Ogura, Takashi Shinohara
Abstract
Three sisters, born from consanguineous parents, manifested a unique Mullerian anomaly characterized by uterine hypoplasia with thin estrogen-unresponsive endometrium, primary amenorrhea, but spontaneous tubal pregnancies. Through whole-exome sequencing followed by comprehensive genetic analysis, a missense variant was identified in the OSR1 gene. We therefore investigated OSR1/OSR1 expression in postpubertal human uteri, and the prenatal and postnatal expression pattern of Osr1/Osr1 in murine developing Mullerian ducts (MDs) and endometrium, respectively. We then investigated whether Osr1 deletion would affect MD development, using wild-type and genetically engineered mice. Human uterine OSR1/OSR1 expression was found primarily in the endometrium. Mouse Osr1 was expressed prenatally in MDs and Wolffian ducts (WDs), from rostral to caudal segments, in E13.5 embryos. MDs and WDs were absent on the left side and MDs were rostrally truncated on the right side of E13.5 Osr1-/- embryos. Postnatally, Osr1 was expressed in mouse uteri throughout lifespan, peaking at postnatal days 14 and 28. Osr1 protein was present primarily in uterine luminal and glandular epithelial cells and in the epithelial cells of mouse oviducts. Through this translational approach, we demonstrated that OSR1/Osr1 is important for MD development and endometrial receptivity and may be implicated in uterine factor infertility.
Authors
Adriana Lofrano-Porto, Sidney Alcântara Pereira, Andrew Dauber, Jordana C.B. Bloom, Audrey N. Fontes, Naomi Asimow, Olívia Laquis de Moraes, Petra Ariadne T. Araujo, Ana Paula Abreu, Michael H. Guo, Silviene F. De Oliveira, Han Liu, Charles Lee, Wendy Kuohung, Michella S. Coelho, Rona S. Carroll, Rulang Jiang, Ursula B. Kaiser
Abstract
Maturation arrest (MA) is a subtype of non-obstructive azoospermia, and male infertility is a known risk factor for testicular tumors. However, the genetic basis for many affected individuals remains unknown. Here, we identified a deleterious hemizygous variant of X-linked retinoblastoma-binding protein 7 (RBBP7) as a potential key cause of MA, which was also found to be associated with the development of Leydig cell tumors. This mutation resulted in premature protein translation termination, affecting the sixth WD40 domain of the RBBP7 and the interaction of the mutated RBBP7 with histone H4. Decreased BRCA1 and increased γH2AX were observed in the proband. In mouse spermatogonial and pachytene spermatocyte-derived cells, deprivation of rbbp7 led to cell cycle arrest and apoptosis. In Drosophila, knockdown of RBBP7/Caf1-55 in germ cells resulted in complete absence of germ cells and reduced testis size, whereas knockdown of RBBP7/Caf1-55 in cyst cells resulted in hyperproliferative testicular cells. Interestingly, male infertility caused by Caf1-55 deficiency was rescued by ectopic expression of wild-type human RBBP7 but not mutant variants, suggesting the importance of RBBP7 in spermatogenesis. Our study provides insights into the mechanisms underlying the co-occurrence of MA and testicular tumors and may pave the way for innovative genetic diagnostics of these 2 diseases.
Authors
Jingping Li, Huimei Zheng, Jiaru Hou, Jianhua Chen, Fengbin Zhang, Xiaohang Yang, Fan Jin, Yongmei Xi
Abstract
BACKGROUND Severe, early-onset fetal growth restriction (FGR) causes significant fetal and neonatal mortality and morbidity. Predicting the outcome of affected pregnancies at the time of diagnosis is difficult, thus preventing accurate patient counseling. We investigated the use of maternal serum protein and ultrasound measurements at diagnosis to predict fetal or neonatal death and 3 secondary outcomes: fetal death or delivery at or before 28+0 weeks, development of abnormal umbilical artery (UmA) Doppler velocimetry, and slow fetal growth.METHODS Women with singleton pregnancies (n = 142, estimated fetal weights [EFWs] below the third centile, less than 600 g, 20+0 to 26+6 weeks of gestation, no known chromosomal, genetic, or major structural abnormalities) were recruited from 4 European centers. Maternal serum from the discovery set (n = 63) was analyzed for 7 proteins linked to angiogenesis, 90 additional proteins associated with cardiovascular disease, and 5 proteins identified through pooled liquid chromatography and tandem mass spectrometry. Patient and clinician stakeholder priorities were used to select models tested in the validation set (n = 60), with final models calculated from combined data.RESULTS The most discriminative model for fetal or neonatal death included the EFW z score (Hadlock 3 formula/Marsal chart), gestational age, and UmA Doppler category (AUC, 0.91; 95% CI, 0.86–0.97) but was less well calibrated than the model containing only the EFW z score (Hadlock 3/Marsal). The most discriminative model for fetal death or delivery at or before 28+0 weeks included maternal serum placental growth factor (PlGF) concentration and UmA Doppler category (AUC, 0.89; 95% CI, 0.83–0.94).CONCLUSION Ultrasound measurements and maternal serum PlGF concentration at diagnosis of severe, early-onset FGR predicted pregnancy outcomes of importance to patients and clinicians.TRIAL REGISTRATION ClinicalTrials.gov NCT02097667.FUNDING The European Union, Rosetrees Trust, Mitchell Charitable Trust.
Authors
Rebecca Spencer, Kasia Maksym, Kurt Hecher, Karel Maršál, Francesc Figueras, Gareth Ambler, Harry Whitwell, Nuno Rocha Nené, Neil J. Sebire, Stefan R. Hansson, Anke Diemert, Jana Brodszki, Eduard Gratacós, Yuval Ginsberg, Tal Weissbach, Donald M. Peebles, Ian Zachary, Neil Marlow, Angela Huertas-Ceballos, Anna L. David
Abstract
SARS-CoV-2 infection during pregnancy is associated with severe COVID-19 and adverse fetal outcomes, but the underlying mechanisms remain poorly understood. Moreover, clinical studies assessing therapeutics against SARS-CoV-2 in pregnancy are limited. To address these gaps, we developed a mouse model of SARS-CoV-2 infection during pregnancy. Outbred CD1 mice were infected at embryonic day (E) 6, E10, or E16 with a mouse adapted SARS-CoV-2 (maSCV2) virus. Outcomes were gestational age-dependent, with greater morbidity, reduced anti-viral immunity, greater viral titers, and impaired fetal growth and neurodevelopment occurring with infection at E16 (3rd trimester-equivalent) than with infection at either E6 (1st trimester-equivalent) or E10 (2nd trimester-equivalent). To assess the efficacy of ritonavir-boosted nirmatrelvir (recommended for pregnant individuals with COVID-19), we treated E16-infected dams with mouse equivalent doses of nirmatrelvir and ritonavir. Treatment reduced pulmonary viral titers, decreased maternal morbidity, and prevented offspring growth restriction and neurodevelopmental impairments. Our results highlight that severe COVID-19 during pregnancy and fetal growth restriction are associated with heightened virus replication in maternal lungs. Ritonavir-boosted nirmatrelvir mitigated maternal morbidity along with fetal growth and neurodevelopment restriction after SARS-CoV-2 infection. These findings prompt the need for further consideration of pregnancy in preclinical and clinical studies of therapeutics against viral infections.
Authors
Patrick S. Creisher, Jamie L. Perry, Weizhi Zhong, Jun Lei, Kathleen R. Mulka, W. Hurley Ryan, Ruifeng Zhou, Elgin H. Akin, Anguo Liu, Wayne Mitzner, Irina Burd, Andrew Pekosz, Sabra L. Klein
Abstract
The transcription factor p63 guards genome integrity in the female germline, and its mutations have been reported in patients with premature ovarian insufficiency (POI). However, the precise contribution of the TP63 gene to the pathogenesis of POI needs to be further determined. Here, in 1,030 Chinese patients with POI, we identified 6 heterozygous mutations of the TP63 gene that impaired the C-terminal transactivation-inhibitory domain (TID) of the TAp63α protein and resulted in tetramer formation and constitutive activation of the mutant proteins. The mutant proteins induced cell apoptosis by increasing the expression of apoptosis-inducing factors in vitro. We next introduced a premature stop codon and selectively deleted the TID of TAp63α in mice and observed rapid depletion of the p63+/ΔTID mouse oocytes through apoptosis after birth. Finally, to further verify the pathogenicity of the mutation p.R647C in the TID that was present in 3 patients, we generated p63+/R647C mice and also found accelerated oocyte loss, but to a lesser degree than in the p63+/ΔTID mice. Together, these findings show that TID-related variants causing constitutive activation of TAp63α lead to POI by inducing oocyte apoptosis, which will facilitate the genetic diagnosis of POI in patients and provide a potential therapeutic target for extending female fertility.
Authors
Chengzi Huang, Simin Zhao, Yajuan Yang, Ting Guo, Hanni Ke, Xin Mi, Yingying Qin, Zi-Jiang Chen, Shidou Zhao
Abstract
Preimplantation embryo arrest (PREMBA) is a common cause of female infertility and recurrent failure of assisted reproductive technology. However, the genetic basis of PREMBA is largely unrevealed. Here, using whole-exome sequencing data from 606 women experiencing PREMBA compared with 2,813 controls, we performed a population and gene–based burden test and identified a candidate gene, karyopherin subunit α7 (KPNA7). In vitro studies showed that identified sequence variants reduced KPNA7 protein levels, impaired KPNA7 capacity for binding to its substrate ribosomal L1 domain-containing protein 1 (RSL1D1), and affected KPNA7 nuclear transport activity. Comparison between humans and mice suggested that mouse KPNA2, rather than mouse KPNA7, acts as an essential karyopherin in embryonic development. Kpna2–/– female mice showed embryo arrest due to zygotic genome activation defects, recapitulating the phenotype of human PREMBA. In addition, female mice with an oocyte-specific knockout of Rsl1d1 recapitulated the phenotype of Kpna2–/– mice, demonstrating the vital role of substrate RSL1D1. Finally, complementary RNA (cRNA) microinjection of human KPNA7, but not mouse Kpna7, was able to rescue the embryo arrest phenotype in Kpna2–/– mice, suggesting mouse KPNA2 might be a homologue of human KPNA7. Our findings uncovered a mechanistic understanding for the pathogenesis of PREMBA, which acts by impairing nuclear protein transport, and provide a diagnostic marker for PREMBA patients.
Authors
Wenjing Wang, Yoichi Miyamoto, Biaobang Chen, Juanzi Shi, Feiyang Diao, Wei Zheng, Qun Li, Lan Yu, Lin Li, Yao Xu, Ling Wu, Xiaoyan Mao, Jing Fu, Bin Li, Zheng Yan, Rong Shi, Xia Xue, Jian Mu, Zhihua Zhang, Tianyu Wu, Lin Zhao, Weijie Wang, Zhou Zhou, Jie Dong, Qiaoli Li, Li Jin, Lin He, Xiaoxi Sun, Ge Lin, Yanping Kuang, Lei Wang, Qing Sang
Abstract
To understand how kidney donation leads to excess preeclampsia risk, we studied pregnant outbred mice with prior uninephrectomy and compared them to sham-treated littermates carrying both kidneys. During pregnancy, uninephrectomized mice failed to achieve physiological increase of glomerular filtration rate, and during late gestation developed hypertension, albuminuria, glomerular endothelial damage, and excess placental production of soluble fms-like tyrosine kinase 1 (sFLT1), an anti-angiogenic protein implicated in the pathogenesis of preeclampsia. Maternal hypertension in uninephrectomized mice was associated with low plasma volumes, increased rate of fetal resorption, impaired spiral artery remodeling and placental ischemia. To evaluate potential mechanisms, we studied plasma metabolite changes using mass spectrometry and noted that L-kynurenine, a metabolite of L-tryptophan, was upregulated ~3 fold during pregnancy when compared to pre-pregnant concentrations in the same animals, consistent with prior reports suggesting a protective role for L-kynurenine in placental health. However, uninephrectomized mice failed to upregulate L-kynurenine during pregnancy; furthermore, when uninephrectomized mice were fed L-kynurenine in drinking water throughout pregnancy, their preeclampsia-like state was rescued, including reversal of placental ischemia and normalization of sFLT1 levels. In aggregate, we provide a mechanistic basis for how impaired renal reserve and resulting failure to upregulate L-kynurenine during pregnancy can lead to impaired placentation, placental hypoperfusion, anti-angiogenic state and subsequent preeclampsia.
Authors
Vincent Dupont, Anders H. Berg, Michifumi Yamashita, Chengqun Huang, Ambart E. Covarrubias, Shafat Ali, Aleksandr Stotland, Jennifer E. Van Eyk, Belinda Jim, Ravi Thadhani, S. Ananth Karumanchi
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ISSN: 0021-9738 (print), 1558-8238 (online)