Biallelic Mutations in CFAP43 and CFAP44 Cause Male Infertility with Multiple Morphological Abnormalities of the Sperm Flagella.

Sperm motility is vital to human reproduction. Malformations of sperm flagella can cause male infertility. Men with multiple morphological abnormalities of the flagella (MMAF) have abnormal spermatozoa with absent, short, coiled, bent, and/or irregular-caliber flagella, which impair sperm motility. The known human MMAF-associated genes, such as DNAH1, only account for fewer than 45% of affected individuals. Pathogenic mechanisms in the genetically unexplained MMAF remain to be elucidated. Here, we conducted genetic analyses by using whole-exome sequencing and genome-wide comparative genomic hybridization microarrays in a multi-center cohort of 30 Han Chinese men affected by MMAF. Among them, 12 subjects could not be genetically explained by any known MMAF-associated genes. Intriguingly, we identified compound-heterozygous mutations in CFAP43 in three subjects and a homozygous frameshift mutation in CFAP44 in one subject. All of these recessive mutations were parentally inherited from heterozygous carriers but were absent in 984 individuals from three Han Chinese control populations. CFAP43 and CFAP44, encoding two cilia- and flagella-associated proteins (CFAPs), are specifically or preferentially expressed in the testis. Using CRISPR/Cas9 technology, we generated two knockout models each deficient in mouse ortholog Cfap43 or Cfap44. Notably, both Cfap43- and Cfap44-deficient male mice presented with MMAF phenotypes, whereas the corresponding female mice were fertile. Our experimental observations on human subjects and animal models strongly suggest that biallelic mutations in either CFAP43 or CFAP44 can cause sperm flagellar abnormalities and impair sperm motility. Further investigations on other CFAP-encoding genes in more genetically unexplained MMAF-affected individuals could uncover novel mechanisms underlying sperm flagellar formation.

Detection of heterozygous mutation in hook microtubule-tethering protein 1 in three patients with decapitated and decaudated spermatozoa syndrome.

BACKGROUND: The mechanism of intramanchette transport is crucial to the transformation of sperm tail and the nuclear condensation during spermiogenesis. Although few dysfunctional proteins could result in abnormal junction between the head and tail of spermatozoon, little is known about the genetic cues in this process. OBJECTIVE: Based on patients with severe decapitated and decaudated spermatozoa (DDS) syndrome, the study aimed to validate whether new mutation exists on their Hook microtubule-tethering protein 1 (HOOK1) genes and follow their results of assisted reproduction treatment (ART). METHODS: 7 severe teratozoospermia patients with DDS (proportion >95%) and three relative members in one pedigree were collected to sequence the whole genomic DNA. The fertilisation rates (FRs) of these patients were followed. Morphological observation and interspecies intracytoplasmic sperm injection (ICSI) assays were applied. RESULTS: A novel missense mutation of A to G (p.Q286R) in patients with DDS (n=3/7) was found in the HOOK1 gene, which was inherited from the mother in one patient. This variant was absent in 160 fertile population-matched control individuals. Morphological observation showed that almost all the DDS broke into decaudated heads and headless tails at the implantation fossa or the basal plate. The clinical studies indicated that the mutation might cause reduced FRs on both ART (FR=18.07%) and interspecies ICSI (FR=16.98%). CONCLUSIONS: An unreported mutation in HOOK1 gene was identified, which might be responsible to some patients with DDS. Further studies need to uncover the molecular mechanism of spermiogenesis for genomic therapy.

[Qilin Pills promote testicular spermatogenesis in azoospermia mice].

OBJECTIVE: To investigate the effect of Qilin Pills (QP) in facilitating the recovery of spermatogenic function in azoospermia (AS) mice and to explore its mechanism of regulating testicular spermatogenesis. METHODS: Fifteen 4-week-old male mice were equally randomized into an AS model control, a low-dose QP and a high-dose QP group. The AS model was established in the mice by intraperitoneal injection of busulfan at 35 mg/kg. After modeling, the animals in the low- and high-dose QP groups were treated with Qilin Pills intragastrically at 2 000 and 8 000 mg/kg/d respectively while those in the model control group fed on a normal diet, all for 28 days. Then, all the mice were sacrificed for examination of the ultrastructures of the epididymis and testis by HE staining, detection of the specific markers of spermatogenic, Sertoli and Leydig cells by Western blot, and determination of the expressions of these markers in the testis tissue by immunofluorescence assay. RESULTS: The number of spermatogenic cells in the testis tissue was significantly decreased in the AS model controls, with no spermatozoa in most of the seminiferous tubules in the epididymis (Johnsen's score: 5.2 ± 0.5). In the high-dose QP group, spermatogenic cells were tightly arranged with distinct layers in the seminiferous tubules, with a large number of spermatozoa but no non-sperm cells in the lumens of the epididymis (Johnsen's score: 9.4 ± 0.6). The number of spermatogenic cells in the testis was increased in the low-dose QP group with some spermatozoa in the seminiferous tubules as compared with that in the model control, but lower than in the high-dose group (Johnsen's score: 7.6 ± 0.6). The Johnsen's score was significantly lower in the model control than in the high- and low-dose QP groups (P < 0.01), and higher in the high-dose than in the low-dose QP group (P < 0.05). The expressions of the specific markers of Sertoli cells SCF, BMP4, SYCP3, DMC1 and Ki67 were also remarkably lower in the model control than in the high- and low-dose QP groups (P < 0.01), and higher in the high-dose than in the low-dose QP group (P < 0.05 or P < 0.01). No statistically significant differences were observed among the three groups of mice in the markers of spermatogonial stem cells (SSC) and undifferentiated SSCs UCHL1, STRA8, NGN3 and PLZF3 (P > 0.05). The expressions of the spermatocyte markers DMC1 and SYCP3 were markedly lower in the model control than in the high- and low-dose QP groups (P < 0.05 or P < 0.01), and higher in the high-dose than in the low-dose QP group (P < 0.05 or P < 0.01). The Ki67 fluorescence signals were distributed in the spermatogonia, with a higher intensity in the model control than in the high- and low-dose QP groups. The acrosome marker PNA was found mainly in the seminiferous tubules, with abundant fluorescence signals in the high- and low-dose QP groups but no obvious dot signals in the model controls. CONCLUSIONS: Qilin Pills may contribute to the meiosis of spermatogonia and promote spermatogenesis by improving the function of Sertoli cells in the testis.

[Impact of plateau environment on seminal characteristics of native Tibetans and immigrated Tibetan Hans].

OBJECTIVE: To investigate the characteristics of the semen parameters of native Tibetans and immigrated Tibetan Hans in the high-altitude area and analyze the influence of altitude adaptation on male fertility. METHODS: This study included 1 563 infertile male patients, including 698 native Tibetans and 865 immigrated Tibetan Hans, and 56 normal fertile men, including 33 native Tibetans and 23 Tibetan Hans. We obtained semen samples from the subjects for routine semen analysis and sperm DNA fragmentation index (DFI) examination and collected peripheral blood for determination of the reproductive hormone levels. RESULTS: In the infertile patients, the native Tibetans, as compared with the immigrated Hans, showed significantly higher incidence rates of azoospermia (5.87% vs 2.89%, P <0.05), severe oligozoospermia (3.15% vs 1.73%, P <0.05) and abnormal seminal viscosity (43.12% vs 25.89%, P<0.01), but no statistically significant differences in the percentages of normozoospermia (81.08% vs 87.39%, P >0.05), oligozoospermia (5.44% vs 3.93%, P >0.05), severe asthenozoospermia (4.44% vs 4.04%, P >0.05) or severe teratozoospermia (4.58% vs 6.59%, P >0.05). In the normal fertile men, there were no statistically significant differences between the native Tibetans and immigrated Hans in age (ï¼»32.42 ± 4.82ï¼½ vs ï¼»34.57 ± 6.01ï¼½ yr, P >0.05), sperm concentration (ï¼»143.69 ± 85.74ï¼½ vs ï¼»155.11 ± 82.56ï¼½ ×106/ml, P >0.05), straight line velocity (ï¼»25.74 ± 3.94ï¼½ vs ï¼»27.24 ± 3.46ï¼½ µm/s, P >0.05), percentage of morphologically normal sperm (ï¼»8.22 ± 4.35ï¼½ vs ï¼»7.28±2.46ï¼½ %, P >0.05), total testosterone concentration (ï¼»17.97 ± 2.98ï¼½ vs ï¼»15.72 ± 6.38ï¼½ nmol/L, P >0.05), or follicle stimulating hormone level (ï¼»5.51 ± 1.62ï¼½ vs ï¼»4.17 ± 2.08ï¼½ IU/L, P >0.05). However, the immigrated Hans, in comparison with the native Tibetans, exhibited a higher sperm motility (ï¼»79.75 ± 14.67ï¼½ vs ï¼»66.58 ± 17.21ï¼½%, P <0.05), a lower curvilinear velocity (ï¼»60.97 ± 2.71ï¼½ vs ï¼»71.14 ± 82.13ï¼½ µm/s, P <0.05) and a lower level of luteinizing hormone (ï¼»4.28 ± 1.20ï¼½ vs ï¼»5.84 ± 1.15ï¼½ IU/L, P <0.05). CONCLUSIONS: During the acclimatization to the plateau hypoxia environment, the immigrated Tibetan Hans undergo adaptive changes in sperm concentration and motility and have lower incidence rates of azoospermia and severe oligozoospermia than native Tibetan males.

BMP4 promotes mouse iPS cell differentiation to male germ cells via Smad1/5, Gata4, Id1 and Id2.

Generation of male germ cells from pluripotent cells could provide male gametes for treating male infertility and offer an ideal model for unveiling molecular mechanisms of spermatogenesis. However, the influence and exact molecular mechanisms, especially downstream effectors of BMP4 signaling pathways, in male germ cell differentiation of the induce pluripotent stem (iPS) cells, remain unknown. This study was designed to explore the role and mechanism of BMP4 signaling in the differentiation of mouse iPS cells to male germ cells. Embryoid body (EB) formation and recombinant BMP4 or Noggin were utilized to evaluate the effect of BMP4 on male germ cell generation from mouse iPS cells. Germ cell-specific genes and proteins as well as the downstream effectors of BMP4 signaling pathway were assessed using real-time PCR and Western blots. We found that BMP4 ligand and its multiple receptors, including BMPR1a, BMPR1b and BMPR2, were expressed in mouse iPS cells. Real-time PCR and Western blots revealed that BMP4 could upregulate the levels of genes and proteins for germ cell markers in iPS cells-derived EBs, whereas Noggin decreased their expression in these cells. Moreover, Smad1/5 phosphorylation, Gata4 transcription and the transcripts of Id1 and Id2 were enhanced by BMP4 but decreased when exposed to Noggin. Collectively, these results suggest that BMP4 promotes the generation of male germ cells from iPS cells via Smad1/5 pathway and the activation of Gata4, Id1 and Id2 This study thus offers novel insights into molecular mechanisms underlying male germ cell development.

VEGF/VEGFR2 Signaling Regulates Germ Cell Proliferation in vitro and Promotes Mouse Testicular Regeneration in vivo.

Vascular endothelial growth factor (VEGF) plays fundamental roles in testicular development; however, its function on testicular regeneration remains unknown. The objective of this study was to explore the roles VEGF/VEGFR2 signaling plays in mouse germ cells and in mouse testicular regeneration. VEGF and the VEGFR2 antagonist SU5416 were added to culture medium to evaluate their effects on spermatogonial stem cell line (C18-4 cells) proliferation. Testicular cells obtained from newborn male ICR mice were grafted into the dorsal region of male BALB/c nude mice. VEGF and SU5416 were injected into the graft sites to assess the effects of the VEGF and VEGFR2 signaling pathways on testicular reconstitution. The grafts were analyzed after 8 weeks. We found that VEGF promoted C18-4 proliferation in vitro, indicating its role in germ cell survival. HE staining revealed that seminiferous tubules were reconstituted and male germ cells from spermatogonia to spermatids could be observed in testis-like tissues 8 weeks after grafting. A few advantaged male germ cells, including spermatocytes and spermatids, were found in SU5416-treated grafts. Moreover, VEGF enhanced the expression of genes specific for male germ cells and vascularization in 8-week grafts, whereas SU5416 decreased the expression of these genes. SU5416-treated grafts had a lower expression of MVH and CD31, indicating that blockade of VEGF/VEGFR2 signaling reduces the efficiency of seminiferous tubule reconstitution. Collectively, these data suggest that VEGF/VEGFR2 signaling regulates germ cell proliferation and promotes testicular regeneration via direct action on germ cells and the enhancement of vascularization.

Association of a TDRD1 variant with spermatogenic failure susceptibility in the Han Chinese.

PURPOSE: Piwi-interacting RNAs (piRNAs) are a broad group of noncoding small RNAs that have important biological functions in germline cells and can maintain genome integrity via silencing of retrotransposons. In this study, we aimed to explore the associations between genetic variants of important genes involved in piRNA biogenesis and male infertility with spermatogenic impairment. METHODS: To this end, five single-nucleotide polymorphisms (SNPs) in the ASZ1, PIWIL1, TDRD1, and TDRD9 genes were genotyped by TaqMan allelic discrimination assays in 342 cases of nonobstructive azoospermia (NOA) and 493 controls. RESULTS: The SNP rs77559927 in TDRD1 was associated with a reduced risk of spermatogenic impairment. The genotypes TC and TC + CC showed odds ratios and 95 % confidence intervals of 0.73 (0.55-0.98, P = 0.034) and 0.73 (0.56-0.97, P = 0.030), respectively, in patients with NOA compared with those in the controls. CONCLUSION: Thus, our results provided the first epidemiological evidence supporting the involvement of TDRD1 genetic polymorphisms in piRNA processing genes in determining the risk of spermatogenic impairment in a Han Chinese population.

Alteration of sperm protein profile induced by cigarette smoking.

Cigarette smoking is associated with lower semen quality, but how cigarette smoking changes the semen quality remains unclear. The aim of this study was to screen the differentially expressed proteins in the sperm of mice with daily exposure to cigarette smoke. The 2D gel electrophoresis (2DE) and mass spectrometry (MS) analyses results showed that the mouse sperm protein profile was altered by cigarette smoking. And 22 of the most abundant proteins that correspond to differentially expressed spots in 2DE gels of the sperm samples were identified. These proteins were classified into different groups based on their functions, such as energy metabolism, reproduction, and structural molecules. Furthermore, the 2DE and MS results of five proteins (Aldoa, ATP5a1, Gpx4, Cs, and Spatc1) were validated by western blot analysis and reverse transcriptase-polymerase chain reaction. Results showed that except Spatc1 the other four proteins showed statistically significant different protein levels between the smoking group and the control group (P < 0.05). The expressions of three genes (Aldoa, Gpx4, and Spatc1) were significantly different (P < 0.05) at transcription level between the smoking group and the control group. In addition, five proteins (Aldoa, ATP5a1, Spatc1, Cs, and Gpx4) in human sperm samples from 30 male smokers and 30 non-smokers were detected by western blot analysis. Two proteins (Aldoa and Cs) that are associated with energy production were found to be significantly altered, suggesting that these proteins may be potential diagnostic markers for evaluation of smoking risk in sperm. Further study of these proteins may provide insight into the pathogenic mechanisms underlying infertility in smoking persons.

[Isolation, culture, and identification of human spermatogonial stem cells].

OBJECTIVE: To isolate, identify and culture human spermatogonial stem cells (SSC) and then obtain purified and enriched human SSCs for research and application. METHODS: We detected the expression of CD90 in the human testis using the immunofluorescence technique and isolated human testicular spermatogenic cells by two-step enzymatic digestion, followed by differential plating and magnetic-activated cell sorting (MACS) with CD90 as an SSC marker. Then we identified the isolated CD90-positive spermatogenic cells by RT-PCR and immunocytochemistry, and meanwhile cocultured them with Sertoli cells in SG medium in vitro. RESULTS: The isolated CD90-positive cells showed a relatively homogeneous characteristic in size and morphology and expressed the genes specific for human SSCs, with high expressions (90.5%) of GFRA1, GPR125, and UCHL1. After coculture with Sertoli cells in the SG medium for 2 weeks, the isolated CD90-positive cells maintained a good activity. CONCLUSION: CD90 can be regarded as a speci- fic marker for human SSCs and used to obtain highly enriched human SSCs by differential plating and MACS. Furthermore, the isolated human SSCs can be cultured in SG medium in vitro.

Cigarette smoking exposure alters pebp1 DNA methylation and protein profile involved in MAPK signaling pathway in mice testis.

Many studies have addressed the role of cigarette smoking on semen quality, but the exact mechanisms remain inconclusive. To evaluate the detrimental effects of smoking on the spermatogenesis process, we initially screened and investigated 31 differentially expressed proteins extracted from the testes of mice exposed daily to cigarette smoke using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry analysis. Data mining analysis showed that these 31 proteins were categorized into five functional clustering groups: metabolic process, cell growth and/or maintenance, RNA and protein processing, stress response, and spermatogenesis. Additionally, 23 of 31 proteins were involved in a main pathway network, including Pkc (s), ERK1/2, Akt, and NF-kappaB, which are known to be involved in cell communication, proliferation, and differentiation. Interestingly, among the 31 proteins, a spermatogenesis-associated protein, phosphatidylethanolamine-binding protein 1 (PEBP1), was especially expressed in serial sections of spermatids of spermiogenesis and interacted with ERKs. The bisulfite sequencing result showed four CpGs near the Pebp1 transcriptional start site were largely methylated in the treated group. A 5-aza-2'-deoxycytidine treatment on GC-1 spg cells reversed the hypermethylation status and elevated both Pebp1 mRNA and protein expression levels. ERK1/2 phosphorylation levels were also increased with upregulation of Pebp1 expression in GC-1 spg cells. In conclusion, protein profile in testes could be altered by cigarette smoking. Moreover, we also suggest that epigenetic Pebp1 inactivation may affect activation of ERK, and it could impair spermatogenesis of mice. Our data could provide further insight into the mechanisms of spermatogenesis.

Efficacy of stepwise mini-incision microdissection testicular sperm extraction for nonobstructive azoospermia with varied etiologies.

Stepwise mini-incision microdissection testicular sperm extraction (mTESE) is a procedure that attempts to minimize testicular damage. However, the mini-incision approach may vary in patients with different etiologies. Here, we performed a retrospective analysis of 665 men with nonobstructive azoospermia (NOA) who underwent stepwise mini-incision mTESE (Group 1) and 365 men who underwent standard mTESE (Group 2). The results showed that the operation time (mean ± standard deviation) for patients with successful sperm retrieval in Group 1 (64.0 ± 26.6 min) was significantly shorter than that in Group 2 (80.2 ± 31.3 min), with P <0.001. The total sperm retrieval rate (SRR) was 23.1% in our study, and there was no significant difference between Group 1 and Group 2 ( P >0.05), even when the etiologies of NOA were taken into consideration. The results of consecutive multivariate logistic regression analysis (odds ratio [OR]: 0.57; 95% confidence interval [CI]: 0.38-0.87; P =0.009) and receiver operating characteristic (ROC) analysis (area under the ROC curve [AUC]=0.628) showed that preoperative anti-Müllerian hormone (AMH) level in idiopathic NOA patients was a potential predictor for surgical outcomes after initial three small incisions made in the equatorial region without sperm examined under an operating microscope (Steps 2-4). In conclusion, stepwise mini-incision mTESE is a useful technique for NOA patients, with comparable SRR, less surgical invasiveness, and shorter operation time compared with the standard approach. Low AMH levels may predict successful sperm retrieval in idiopathic patients even after a failed initial mini-incision procedure.

scRNA-seq reveals that origin recognition complex subunit 6 regulates mouse spermatogonial cell proliferation and apoptosis via activation of Wnt/ß-catenin signaling.

ABSTRACT: The regulation of spermatogonial proliferation and apoptosis is of great significance for maintaining spermatogenesis. The single-cell RNA sequencing (scRNA-seq) analysis of the testis was performed to identify genes upregulated in spermatogonia. Using scRNA-seq analysis, we identified the spermatogonia upregulated gene origin recognition complex subunit 6 (Orc6), which is involved in DNA replication and cell cycle regulation; its protein expression in the human and mouse testis was detected by western blot and immunofluorescence. To explore the potential function of Orc6 in spermatogonia, the C18-4 cell line was transfected with control or Orc6 siRNA. Subsequently, 5-ethynyl-2-deoxyuridine (EdU) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays, flow cytometry, and western blot were used to evaluate its effects on proliferation and apoptosis. It was revealed that ORC6 could promote proliferation and inhibit apoptosis of C18-4 cells. Bulk RNA sequencing and bioinformatics analysis indicated that Orc6 was involved in the activation of wingless/integrated (Wnt)/ ß-catenin signaling. Western blot revealed that the expression of ß-catenin protein and its phosphorylation (Ser675) were significantly decreased when silencing the expression of ORC6. Our findings indicated that Orc6 was upregulated in spermatogonia, whereby it regulated proliferation and apoptosis by activating Wnt/ß-catenin signaling.

Xenotransplantation of Human Spermatogonia Into Various Mouse Recipient Models.

Spermatogonial stem cells are the foundation of continuous spermatogenesis in adult mammals. Xenograft models have been established to define human SSCs, mostly using infertile and immune-deficient mice as the recipients for human germ cell transplantation. However, it is time-consuming to prepare such recipients using irradiation or chemotherapeutic agents, and this approach may also introduce confounding factors when residual endogenous germ cells recover in transplanted recipients. It remains to be determined whether immune-competent genetically infertile mice can be suitable recipients for xenotransplantation. In this study, we observed similar engraftment efficiencies when using spermatogonia from human biopsied testes across immune-deficient nude mice, immune-competent ICR mice, and genetically infertile Kit w/w-v mice, suggesting minimal immunological rejection from immune-competent mouse recipients upon xenotransplantation of human germ cells. More importantly, we derived EpCAM negative and TNAP positive spermatogonia-like cells (SLCs) from human pluripotent stem cells (PSCs), which highly expressed spermatogonial markers including PLZF, INTERGRINα6, TKTL1, CD90, and DRMT3. We found that upon transplantation, these SLCs proliferated and colonized at the basal membrane of seminiferous tubules in testes of both immune-deficient nude mice and Kit w/w-v mice, though complete spermatogenesis would likely require supporting human signaling factors and microenvironment. Taken together, our study functionally defined the cell identity of PSC-derived SLCs, and supported xenotransplantation using genetically infertile recipients as a convenient model for functionally evaluating spermatogonia derived from different species.

Clinical benefits of a modified Cryopiece system for cryopreservation of rare ejaculated and testicular spermatozoa for ICSI.

Cryopreservation of rare testicular-retrieved spermatozoa for intracytoplasmic sperm injection (ICSI) in patients with severe oligozoospermia and azoospermia remains a major challenge in clinical practice. This study evaluated the Cryopiece system as a potential technique to cryopreserve rare human spermatozoa for ICSI. Small numbers of ejaculated (24 patients) and testicular (13 patients) spermatozoa were cryopreserved using the Cryopiece system. The total number of recovered spermatozoa and motility were assessed after thawing. Thirty-seven couples underwent ICSI using spermatozoa cryopreserved by the Cryopiece system, and ICSI outcomes (rates of fertilization, embryo cleavage, and clinical pregnancy) were evaluated. The average sperm post-thaw retrieval rate was 79.1%, and motility was 29.7%. Ejaculated spermatozoa had a higher post-thaw motility (32.5%) than testicular spermatozoa (21.8%; P = 0.005). ICSI achieved a fertilization rate of 61.9%, embryo cleavage rate of 84.6%, and clinical pregnancy rate of 43.3%. The ICSI outcomes in the ejaculated and testicular frozen-thawed spermatozoa were similar. Assisted oocyte activation (AOA) after ICSI with motile (72.1%) or immotile (71.9%) spermatozoa resulted in a significantly higher fertilization rate than that when using motile spermatozoa without AOA (52.0%; P = 0.005). However, AOA did not enhance the clinical pregnancy rate (55.6% or 40.0% vs 35.3%; P = 0.703). The Cryopiece system is simple and useful for the cryopreservation of small numbers of ejaculated or testicular spermatozoa for ICSI in patients with severe oligozoospermia or nonobstructive azoospermia.

Novel mutation in ODF2 causes multiple morphological abnormalities of the sperm flagella in an infertile male.

Numerous genes have been associated with multiple morphological abnormalities of the sperm flagella (MMAF), which cause severe asthenozoospermia and lead to male infertility, while the causes of approximately 50% of MMAF cases remain unclear. To reveal the genetic causes of MMAF in an infertile patient, whole-exome sequencing was performed to screen for pathogenic genes, and electron microscope was used to reveal the sperm flagellar ultrastructure. A novel heterozygous missense mutation in the outer dense fiber protein 2 (ODF2) gene was detected, which was inherited from the patient's mother and predicted to be potentially damaging. Transmission electron microscopy revealed that the outer dense fibers were defective in the patient's sperm tail, which was similar to that of the reported heterozygous Odf2 mutation mouse. Immunostaining of ODF2 showed severe ODF2 expression defects in the patient's sperm. Therefore, it was concluded that the heterozygous mutation in ODF2 caused MMAF in this case. To evaluate the possibility of assisted reproductive technology (ART) treatment for this patient, intracytoplasmic sperm injection (ICSI) was performed, with the help of a hypo-osmotic swelling test and laser-assisted immotile sperm selection (LAISS) for available sperm screening, and artificial oocyte activation with ionomycin was applied to improve the fertilization rate. Four ICSI cycles were performed, and live birth was achieved in the LAISS-applied cycle, suggesting that LAISS would be valuable in ART treatment for MMAF.

Cryopiece, a novel carrier with faster cooling rate, high recovery rate and retrieval rate, for individual sperm cryopreservation.

BACKGROUND: Cryopreservation of extremely few spermatozoa is still a major challenge for male fertility preservation. This study aims to evaluate the cooling rate, recovery rate, and retrieval rate, along with other parameters of spermatozoa that cryopreserved using Cryopiece, a novel carrier, for individual sperm cryopreservation. METHODS: Semen samples from 60 fertile donors were collected, and each semen sample was screened for motile sperm and mixed with cryoprotective agent (CPA), and then frozen using Cryopiece, micro-straw, and mini-straws. The cooling rate, retrieval rate, and recovery rate, morphology, DNA fragmentation index (DFI) and mitochondrial membrane potential (MMP), were compared among the un-frozen sperm and the sperm cryopreserved using these carriers. RESULTS: Cryopiece possessed the fastest cooling rate. After freeze-thaw, the average retrieval rate of sperm cryopreserved using Cryopiece was 96.25%, and the average recovery rate was 64.40%, which were higher than that of sperm cryopreserved using the other two carriers (71.42% and 54.30% for micro-straw, and 63.54% and 58.04% for mini-straw, respectively). There was no significant impact on DFI after sperm cryopreservation, and no significant difference in morphology between sperm cryopreserved using these carriers was observed. Though MMP of sperm changed significantly after cryopreservation, micro-straw maintained sperm MMP better than Cryopiece and mini-straw did, while no significant difference was observed in MMP between sperm cryopreserved using Cryopiece and mini-straw. CONCLUSIONS: Cryopiece produced satisfying retrieval and recovery rates in sperm cryopreservation and should be an ideal carrier for cryopreservation of small number of sperm.

Novel Hemizygous Mutations of TEX11 Cause Meiotic Arrest and Non-obstructive Azoospermia in Chinese Han Population.

Testis-expressed gene 11 (TEX11) mutation has been associated with non-obstructive azoospermia (NOA) and meiotic arrest. An analogous mutation of TEX11 in the mouse impairs meiosis and can be rescued by in vitro expansion of SSCs and gene therapy. However, a lack of genetic screening of a large cohort of Asian patients (including pedigree analysis) and proper functional evaluation limit the clinical application of TEX11 mutation screening. Thus, we performed whole-exome sequencing (WES) in 479 patients with NOA and identified three novel mutations (two splicing mutations and one missense mutation) in TEX11 in three pairs of siblings from three families and four novel pathogenic mutations (three frameshift mutations and a non-sense mutation) of TEX11 in four sporadic NOA-affected cases. Novel variants among family members were segregated by disease phenotype, and all the seven mutations were predicted to be pathogenic. Histological analysis showed that three patients with TEX11 mutations underwent meiotic arrest. The four mutations that resulted in protein truncations and defective meiosis-specific sporulation domain SPO22 were validated by Western blot. In total, we find seven of 479 patients of NOA (1.5%) carrying TEX11 mutations. Our study expands the knowledge of mutations of TEX11 gene in Asian patients with NOA. The high prevalence and X-linked inherited mode indicated that TEX11 might be included in genetic screening panels for the clinical evaluation of patients with NOA.

Derivation and propagation of spermatogonial stem cells from human pluripotent cells.

OBJECTIVES: This study is designed to generate and propagate human spermatogonial stem cells (SSCs) derived from human pluripotent stem cells (hPSCs). METHODS: hPSCs were differentiated into SSC-like cells (SSCLCs) by a three-step strategy. The biological characteristics of SSCLCs were detected by immunostaining with antibodies against SSC markers. The ability of self-renewal was measured by propagating for a long time and still maintaining SSCs morphological property. The differentiation potential of SSCLCs was determined by the generation of spermatocytes and haploid cells, which were identified by immunostaining and flow cytometry. The transcriptome analysis of SSCLCs was performed by RNA sequencing. The biological function of SSCLCs was assessed by xeno-transplantation into busulfan-treated mouse testes. RESULTS: SSCLCs were efficiently generated by a 3-step strategy. The SSCLCs displayed a grape-like morphology and expressed SSC markers. Moreover, SSCLCs could be propagated for approximately 4 months and still maintained their morphological properties. Furthermore, SSCLCs could differentiate into spermatocytes and haploid cells. In addition, SSCLCs displayed a similar gene expression pattern as human GPR125+ spermatogonia derived from human testicular tissues. And more, SSCLCs could survive and home at the base membrane of seminiferous tubules. CONCLUSION: SSCLCs were successfully derived from hPSCs and propagated for a long time. The SSCLCs resembled their counterpart human GPR125+ spermatogonia, as evidenced by the grape-like morphology, transcriptome, homing, and functional characteristics. Therefore, hPSC-derived SSCLCs may provide a reliable cell source for studying human SSCs biological properties, disease modeling, and drug toxicity screening.

Single-cell analysis of developing and azoospermia human testicles reveals central role of Sertoli cells.

Clinical efficacy of treatments against non-obstructive azoospermia (NOA), which affects 1% of men, are currently limited by the incomplete understanding of NOA pathogenesis and normal spermatogenic microenvironment. Here, we profile >80,000 human testicular single-cell transcriptomes from 10 healthy donors spanning the range from infant to adult and 7 NOA patients. We show that Sertoli cells, which form the scaffold in the testicular microenvironment, are severely damaged in NOA patients and identify the roadmap of Sertoli cell maturation. Notably, Sertoli cells of patients with congenital causes (Klinefelter syndrome and Y chromosome microdeletions) are mature, but exhibit abnormal immune responses, while the cells in idiopathic NOA (iNOA) are physiologically immature. Furthermore, we find that inhibition of Wnt signaling promotes the maturation of Sertoli cells from iNOA patients, allowing these cells to regain their ability to support germ cell survival. We provide a novel perspective on the development of diagnostic methods and therapeutic targets for NOA.

Intra-Seminiferous Tubular Injection of Vascular Endothelial Growth Factor C Sustained-Release Ultrafine Particles: A Novel Method for Improving the Regeneration of Spermatogenesis After Chemotherapy.

Busulfan and other chemotherapeutic drugs used in the treatment of cancer may result in temporary or even permanent damage to spermatogenesis. During spermatogenesis, the rapidly dividing spermatogonia are highly susceptible to chemotherapy. Consequently, there is significant interest in developing an approach that could provide stimulation and regenerate spermatogenesis after chemotherapy. In a previous study, we suggested the potential application for vascular endothelial growth factor C (VEGFC) because of its key role in stimulating the proliferation of spermatogonia. However, methods to facilitate the recovery of spermatogenesis in such patients using VEGFC, or other regulatory factors, are sorely lacking because of the rapid degradation of these proteins and restrictions created by the blood-testis-barrier. To this end, we loaded VEGFC into polyanion dextran sulfate incorporated in a polycation chitosan shell to produce VEGFC sustained-release ultrafine particles (UFPs, CS-DS-VEGFC). We tested such particles in an azoospermic mouse model, created using busulfan. For each mouse, CS-DS-VEGFC was injected into the seminiferous tubules of one testis, while unloaded UFPs (CS-DS), or the VEGFC protein alone, was injected into the opposite testis as a control. All mice were sacrificed and evaluated 5 weeks later. Spermatogenesis in the tubules that were injected with CS-DS-VEGFC was clearly better than those injected with controls, and contained more spermatogonia and spermatocytes, along with Ki67 and PCNA positive-cells per tubule. In addition, the phosphorylation levels of AKT and MAPK in these tubules were also higher than in controls, indicating that CS-DS-VEGFC could induce the sustained activation of these pathways. In conclusion, CS-DS-VEGFC, combined with the efferent tubule injection technique, is a feasible approach with which to improve the regeneration of spermatogenesis in busulfan-induced azoospermic mice.