STUDY QUESTION:What is the mechanism behind cryoinjury in human sperm, particularly concerning the interplay between reactive oxygen species (ROS) and autophagy, and how does it subsequently affect sperm fate? SUMMARY ANSWER:The freeze-thaw operation induces oxidative stress by generating abundant ROS, which impairs sperm motility and activates autophagy, ultimately guiding the sperm toward programmed cell death such as apoptosis and necrosis, as well as triggering premature capacitation. WHAT IS KNOWN ALREADY:Both ROS-induced oxidative stress and autophagy are thought to exert an influence on the quality of frozen-thawed sperm. STUDY DESIGN, SIZE, DURATION:Overall, 84 semen specimens were collected from young healthy fertile males, with careful quality evaluation. The specimens were split into three groups to investigate the ROS-induced cryoinjury: normal control without any treatment, sperm treated with 0.5 mM hydrogen peroxide (H2O2) for 1 h, and sperm thawed following cryopreservation. Samples from 48 individuals underwent computer-assisted human sperm analysis (CASA) to evaluate sperm quality in response to the treatments. Semen samples from three donors were analyzed for changes in the sperm proteome after H2O2 treatment, and another set of samples from three donors were analyzed for changes following the freeze-thaw process. The other 30 samples were used for fluorescence-staining and western blotting. PARTICIPANTS/MATERIALS, SETTING, METHODS:Sperm motility parameters, including progressive motility (PR %) and total motility (PR + NP %), were evaluated using the CASA system on a minimum of 200 spermatozoa. The proteomic profiles were determined with label-free mass spectrometry (MS/MS) and protein identification was performed via ion search against the NCBI human database. Subsequently, comprehensive bioinformatics was applied to detect significant proteomic changes and functional enrichment. Fluorescence-staining and western blot analyses were also conducted to confirm the proteomic changes on selected key proteins. The ROS level was measured using 2',7'-dichlorodihydrofluorescein diacetate labeling and the abundance of bioactive mitochondria was determined by evaluating the inner mitochondrial membrane potential (MMP) level. Molecular behaviors of sequestosome-1 (p62 or SQSTM1) and microtubule-associated proteins 1A/1B light chain 3 (LC3) were monitored to evaluate the state of apoptosis in human sperm. Fluorescent probes oxazole yellow (YO-PRO-1) and propidium iodide (PI) were utilized to monitor programmed cell death, namely apoptosis and necrosis. Additionally, gradient concentrations of antioxidant coenzyme Q10 (CoQ10) were introduced to suppress ROS impacts on sperm. MAIN RESULTS AND THE ROLE OF CHANCE:The CASA analysis revealed a significant decrease in sperm motility for both the H2O2-treatment and freeze-thaw groups. Fluorescence staining showed that high ROS levels were produced in the treated sperm and the MMPs were largely reduced. The introduction of CoQ10 at concentrations of 20 and 30 μM resulted in a significant rescue of progressive motility (P < 0.05). The result suggested that excessive ROS could be the major cause of sperm motility impairment, likely by damaging mitochondrial energy generation. Autophagy was significantly activated in sperm when they were under oxidative stress, as evidenced by the upregulation of p62 and the increased conversion of LC3 as well as the upregulation of several autophagy-related proteins, such as charged multivesicular body protein 2a, mitochondrial import receptor subunit TOM22 homolog, and WD repeat domain phosphoinositide-interacting protein 2. Additionally, fluorescent staining indicated the occurrence of apoptosis and necrosis in both H2O2-treated sperm and post-thaw sperm. The cell death process can be suppressed when CoQ10 is introduced, which consolidates the view that ROS could be the major contributor to sperm cryoinjury. The freeze-thaw process could also initiate sperm premature capacitation, demonstrated by the prominent increase in tyrosine phosphorylated proteins, verified with anti-phosphotyrosine antibody and immunofluorescence assays. The upregulation of capacitation-related proteins, such as hyaluronidase 3 and Folate receptor alpha, supported this finding. LARGE SCALE DATA:The data underlying this article are available in the article and its online supplementary material. LIMITATIONS, REASONS FOR CAUTION:The semen samples were obtained exclusively from young, healthy, and fertile males with progressive motility exceeding 60%, which might overemphasize the positive effects while possibly neglecting the negative impacts of cryoinjury. Additionally, the H2O2 treatment conditions in this study may not precisely mimic the oxidative stress experienced by sperm after thawing from cryopreservation, potentially resulting in the omission of certain molecular alterations. WIDER IMPLICATIONS OF THE FINDINGS:This study provides substantial proteomic data for a comprehensive and deeper understanding of the impact of cryopreservation on sperm quality. It will facilitate the design of optimal protocols for utilizing cryopreserved sperm to improve applications, such as ART, and help resolve various adverse situations caused by chemotherapy, radiotherapy, and surgery. STUDY FUNDING/COMPETING INTEREST(S):This work was supported by grants from the Major Innovation Project of Research Institute of National Health Commission (#2022GJZD01-3) and the National Key R&D Program of China (#2018YFC1003600). All authors declare no competing interests. TRIAL REGISTRATION NUMBER:N/A.

INTRODUCTION High levels of reactive oxygen species (ROS) have potential toxic effects on testicular function and sperm quality. Peroxiredoxins (PRDXs) are enzymes with a role as ROS scavenger. The aim of the study was to reveal the presence and localization of PRDXs in human testis, epididymis and spermatozoa, and the protective roles of PRDX2 and PRDX6 in sperm motility. MATERIAL AND METHODS The presence and localization of PRDXs in the human testis, epididymis and spermatozoa were detected by immunohistochemistry, western blot and immunofluorescence. The effect of anti-peroxidative damage to spermatozoa was examined by adding H2O2 to the recombinant protein-treated spermatozoa. RESULTS There were strong signals of PRDX1 in spermatogonia and round spermatids; PRDX2 in the round spermatids; PRDX4 and 5 in spermatogonia; PRDX6 in Sertoli cells. PRDXs were also found in epididymal epithelial cells where the expression of PRDX1, 4, 5, 6 in the cauda was higher than in the caput of epididymis. PRDX1-6 immunoreactivity was found throughout acrosome, post-acrosomal region, equatorial segment, neck and cytoplasmic droplet, midpiece and principal piece. The H2O2-induced reduction in sperm motility was reversed by recombinant PRDX2 or PRDX6 in a dose-dependent manner. CONCLUSIONS PRDX1-6 in the human testis and epididymis presented cell-specificity. PRDX2 and 6 are potential antioxidant protectors for human spermatozoa.

Heat stress is demonstrated to have an effect on the function of the male testis, however, limited information has been reported on its effects on sperm maturation. In the present study, a comparative proteomic analysis was performed on the rat caput epididymal fluids responsible for sperm maturation, to identify key heat‑stress‑associated sperm maturation proteins. The results demonstrated 21 proteins corresponding to 29 differential protein spots, including 10 downregulated and 11 upregulated proteins in the heat treatment group. Functional analysis demonstrated that these proteins were primarily involved in enriched reproduction and antioxidant activity. Analysis of western blot and immunohistochemical analysis demonstrated that the expression of antioxidant proteins peroxiredoxin 6 and clusterin were downregulated, and the expression of superoxide dismutase upregulated, in the heat treatment group. Morphological and TUNEL experiments demonstrated that altered nucleus activity occurred in the caput epididymis. The study provided, to the best of our knowledge, novel information for studies on the biological functions of the epididymis and sperm maturation.

HSP110 functions to protect cells, tissues, and organs from noxious conditions. Vasectomy induces apoptosis in the testis; however, little is known about the reason leading to this outcome. The aim of the present study was to evaluate the expression and function of HSP110 in mouse testis after vasectomy. Following bilateral vasectomy, we used fluorescent Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) to detect apoptosis, Western blotting and immunohistochemistry to examine HSP110 expression and localization. Serum antisperm antibody (AsAb) and testosterone were measured by Enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay, respectively. Expression of endoplasmic reticulum stress (ERS) sensors and downstream signaling components was measured by Reverse Transcription-Polymerase Chain Reaction (RT-PCR), and the phosphorylation of eIF2α and JNK was detected by Western blotting. Vasectomy induced morphologic changes, increased apoptosis in the testis, increased serum AsAb, and decreased testosterone levels. After vasectomy, ORP150 mRNA level was increased first and then decreased, Bcl-2 was decreased, and the expression of HSPA4l, GRP78, GADD153, PERK, ATF6, IRE-1, XBP-1s, Bax, Bak, and caspases and the phosphorylation of eIF2α and JNK were increased. We present that an ER stress-mediated pathway is activated and involved in apoptosis in the testis after vasectomy. HSPA4l and ORP150 may play important roles in maintaining the normal structure and function of testis.

BACKGROUND:Human pancreatic islet transplantation is a prospective curative treatment for diabetes. However, the lack of donor pancreases greatly limits this approach. One approach to overcome the limited supply of donor pancreases is to generate functional islets from human embryonic stem cells (hESCs), a cell line with unlimited proliferative capacity, through rapid directed differentiation. This study investigated whether pancreatic insulin-producing cells (IPCs) differentiated from hESCs could correct hyperglycemia in severe combined immunodeficient (SCID)/non-obese diabetic (NOD) mice, an animal model of diabetes.METHODS:We generated pancreatic IPCs from two hESC lines, YT1 and YT2, using an optimized four-stage differentiation protocol in a chemically defined culture system. Then, about 5-7 × 10(6) differentiated cells were transplanted into the epididymal fat pad of SCID/NOD mice (n = 20). The control group were transplanted with undifferentiated hESCs (n = 6). Graft survival and function were assessed using immunohistochemistry, and measuring serum human C-peptide and blood glucose levels.RESULTS:The pancreatic IPCs were generated by the four-stage differentiation protocol using hESCs. About 17.1% of differentiated cells expressed insulin, as determined by flow cytometry. These cells secreted insulin/C-peptide following glucose stimulation, similarly to adult human islets. Most of these IPCs co-expressed mature β cell-specific markers, including human C-peptide, GLUT2, PDX1, insulin, and glucagon. After implantation into the epididymal fat pad of SCID/NOD mice, the hESC-derived pancreatic IPCs corrected hyperglycemia for ≥ 8 weeks. None of the animals transplanted with pancreatic IPCs developed tumors during the time. The mean survival of recipients was increased by implanted IPCs as compared to implanted undifferentiated hESCs (P<0.0001).CONCLUSIONS:The results of this study confirmed that human terminally differentiated pancreatic IPCs derived from hESCs can correct hyperglycemia in SCID/NOD mice for ≥8 weeks.

C-type lysozyme genes (Lyzls) belong to the class of lysozymes and are highly expressed in the testis and epididymis. The members Lyzl4 and Spaca3 have been reported to play a role in sperm-egg binding and fertilisation in mice. However, the function of the remaining two mouse c-type lysozyme genes, Lyzl1 and Lyzl6, is still not clear. In the present study, we analysed the tissue expression and androgen-dependent expression of mouse c-type lysozyme genes and the possible contribution of human recombinant LYZL6 (rLYZL6) to immunity. The expression of Lyzls was detected by RT-PCR, Western blots, immunohistochemistry and immunofluorescence. The bacteriolytic activity of rLYZL6 was analysed by a colony-forming assay. In mice, the expression of Lyzl genes was mainly in the testis and epididymis in a developmentally regulated manner and androgen- or testicular factor-regulated manner. Immunodetection revealed the presence of LYZL6 protein in primary spermatocytes and round spermatids of the testis and on the post-acrosomal area and midpiece of mature epididymal spermatozoa. The rLYZL6 protein exhibited antibacterial activity. From the results, Lyzls may play a role in mitochondrial function of spermatozoa and LYZL6 may contribute to the innate immunity of the male genital tract.

目的探讨体外诱导人胚胎干细胞(hESs)定向分化为胰岛细胞的可行性。方法体外分三阶段诱导hESCs定向分化为胰岛细胞。第一阶段:予以活化素-A、渥曼青霉素诱导分化形成定型内胚层;第二阶段:采用维甲酸(RA)、NOGGIN、碱性成纤维细胞生长因子(bFGF)诱导胰腺细胞定向分化;以EGF扩增胰腺祖细胞;第三阶段:采用尼克酰胺、唾液素4、bFGF及骨形成蛋白(BMP4)促进胰岛细胞成熟;观察诱导各阶段细胞形态变化,免疫荧光法鉴定胰十二指肠同源异型盒基因(PDX-1)、胰高糖素、胰岛素、C肽、葡萄糖转运子2(glut-2)表达。结果诱导14 d时hESs出现胰高糖素荧光表达;20 d时细胞出现PDX-1和C肽共表达;22 d形成的成熟胰岛细胞出现glut-2和胰岛素的阳性表达;胰岛素阳性细胞占17.1%,C肽阳性细胞占3.8%。结论体外可简单高效的诱导hESs定向分化为成熟胰岛细胞。

PURPOSE To investigate the effect of topical administration of peroxiredoxin-6 (PRDX6) on ultraviolet-induced corneal injury. METHODS Corneal transparency and neovascularization were observed with a slit-lamp microscope and hematoxylin and eosin staining. The oxidative damage was determined with a commercial malondialdehyde (MDA) kit. The expressions of PRDX6, polymorphonuclear neutrophil (PMN), vascular endothelial growth factor (VEGF), and pigment epithelium-derived factor (PEDF) were determined by immunohistochemistry and Western blot. The expressions of genes related with antioxidant defense systems and cell apoptosis were detected by RT-PCR. RESULTS The irradiated corneas appeared opaque and had high levels of MDA. Peripheral neovascularization and neutrophils appeared in the control and buffer-treated groups (with no treatment or PRDX6 diluent, respectively), whereas they were significantly suppressed in the PRDX6-treated group. The MDA content of the corneas in the PRDX6-treated group was significantly lower than that of the control and buffer-treated groups (P < 0.05). In the PRDX6-treated group the immunoreactivity of VEGF was lower, and that of PEDF was higher, than that in the control and buffer-treated groups. In addition, there were expression correlations between PRDX6 and PMN, VEGF, PEDF. The expressions of genes related with antioxidant defense systems and cell apoptosis were significant different between buffer- and PRDX6-treated groups (P < 0.05). CONCLUSIONS The topically administered PRDX6 maintained the homeostasis of corneal cells, reduced inflammation, and suppressed neovascularization and apoptosis under ultraviolet irradiation.

The epididymis plays a crucial role in regulating the development of sperm motility and fertilizing capacity. Small non-coding RNAs (sncRNAs), especially microRNAs (miRNAs), can participate in the regulation of various physiological pathways. However, their abundance and whether they are involved in the regulation of gene expression in the human epididymis are unknown. By adopting the Solexa deep sequencing approach, we systematically investigated the sncRNAs in the adult human epididymis. A total of 4903 unique sequences representing 527 known miRNA were discovered. Eighteen novel miRNA genes encoding 23 mature miRNAs were also identified and the expression of some of them was confirmed by qRT-PCR. The presence of Piwi-interacting RNAs (piRNAs) in the library also adds to the diversity of the sncRNA population in the human epididymis. This research will contribute to a preliminary database for their functional study in male reproductive system.

We describe the derivation and characterization of three novel human embryonic stem (hES) cell lines (YT1, YT2, YT3). One hES line (YT1) was obtained from six discarded blastocysts in a culture medium supplemented with 12 ng/ml basic fibroblast growth factor (bFGF), and two lines (YT2,YT3)were obtained from three discarded blastocysts in the same medium but supplemented with 16 ng/ml bFGF. These cell lines were derived by partial or whole embryo culture followed by further expansion after manual dissection of the passaged cells. These cells were passaged continuously for more than 6 or 8 months and possessed all of the typical features of pluripotent hES cell lines, such as typical morphological characteristics and the expression of hES-specific markers (TRA-1-60, TRA-1-81, SSEA-4, SSEA-3, alkaline phosphatase, Oct4, Nanog) and pluripotency-related genes (Oct4, Nanog, TDGF1, Sox2, EBAF, Thy-1, FGF4, Rex1). The lines maintained normal karyotypes after long-term cultivation. The karyotype of YT1 and YT3 was 46,XX, and that of YT2 was 46, XY. Pluripotency was confirmed by in vitro and in vivo differentiation, and genetic identity was demonstrated by DNA fingerprinting.Our results indicate that higher concentrations of bFGF at the early culture stage support efficient the hES cell derivation.

The testis is the special male gonad responsible for spermatogenesis and steroidogenesis with complex gene expressions. Characterizing and comparing the testis-specific genes in different species can reveal key genes related to testis specific functions and provide supplementary information for study of human testis function. We screened testis-specific genes from Unigene libraries, total 317, 449 and 147 testis-specific genes were identified for human, mouse and rat, respectively. Ten from thirteen selected human testis-specific genes were validated exclusively expressed in the testis by reverse transcription polymerase chain reaction (RT-PCR). Systematic bioinformatics analysis showed that specific genes were mainly related to spermatogenesis and testis development process with significant Glycolysis and Pyruvate metabolism. Enrichment functions were discussed.

Somatic cell nuclear transfer (SCNT) was used to generate patient-specific embryonic stem cells (ESCs) from blastocysts cloned by nuclear transfer (ntESCs). In this study, a total of 135 oocytes were obtained from 12 healthy donors (30-35 years). Human oocytes, obtained within 2 h following transvaginal aspiration, were enucleated using a Spindle Imaging System to position the spindle and chromosomes that lay on the metaphase plate, and a Zona Infrared Laser Optical System was used to open a single hole in the zona pellucida at the ~ 2 o'clock position. Human fibroblasts and lymphocytes were used to construct SCNT embryos. Nearly half (26 of 58) of the oocytes were fused after electrofusion and embryo development rates were 96.2% (two-cell, 25 of 26), 92.3% (four-cell, 24 of 26), 61.5% (eight-cell, 16 of 26), 34.6% (16-cell, 9 of 26), 26.9% (morula, 7 of 26), and 19.2% (blastocyst, 5 of 26), respectively, following incubation in improved G-series sequential medium. One cloned blastocyst was used for STR-DNA identification and genetic polymorphism analysis of mtDNA, and STR-DNA analysis of all cloned blastocysts indicated they were derived from SCNT. Quantitative analysis showed that mtDNA of cloned embryos reflected the change tendency of those observed in human IVF embryos. Our research provides an alternative enucleation approach for producing human SCNT-derived blastocysts, and may aid in providing a new method for human therapeutic cloning.

Sperm maturation in the epididymis is regulated by changes of luminal ion concentration and processing of sperm surface membrane by several glycosidases and proteases, and the actions of the proteases are controlled by protease inhibitors present in specific areas of the epididymis. WFDC-type serine protease inhibitors that are highly expressed in the epididymis play an important role in natural immunity and male reproduction. This paper gives an overview of the structure and function of the protein and its application prospects in the development of drugs for male reproductive tract infection and immunocontraception.

BACKGROUND:Mammalian spermatozoa become fully motile and fertile during transit through the luminal fluid of the epididymis. At least 200 proteins are present in the epididymal lumen, but the potential roles of these luminal proteins in male fertility are unknown. Investigation of the function of these proteins will elucidate the mechanism of sperm maturation, and also provide new drug targets for male contraception. We cloned RNase9 from a human epididymis cDNA library for characterization and analysis of its functions.FINDINGS:It was predicted that human RNase9 gene was located on chromosome 14q11.2 and encoded a 205 amino acids protein with a signal peptide of 26 amino acids at the N-terminus. The protein had eight conserved cysteine residues characteristic of the RNase A family members and several potential post-translational modification sites.At the transcriptional level, RNase9 was expressed in a wide variety of tissues, and the expression was higher in men than in boys. RNase9 was localized to the post-equatorial region of the sperms' head. Immunofluorescence staining showed that RNase9 protein was present mostly in the epithelium of the epididymal tubule. Recombinant RNase9 had no ribonuclease activity. In addition, RNase9 had no detectable effect on sperm motility and fertilization as demonstrated by blocking spermatozoa with anti-RNase9 polyclonal serum.CONCLUSION:RNase9 is expressed in a wide variety of tissues. It is located on the post-equatorial region of the sperm head and the epithelium of epididymal tubule. Although RNase9 belongs to the RNase A family, it has no ribonuclease activity.

We reconstructed cloned embryos of different genetic diseases by somatic cell nuclear transfer.We want to establish a system for basic researches and clinical therapies of these diseases.At first, we transferred human fetal fibroblast cells into 58 enucleated human oocytes and 21 cloned embryos were reconstructed by electrofusion.After physical and chemical activation, reconstructed embryos developed in vitro 2-cell embryos (20, 95.2%), 4-cell embryos (19, 90.5%), 8-cell embryos (13. 61.9%), 16-cell embryos (7, 33.3%), morula (6, 28.6%), and blastocysts (4, 19.1%), respectively.The STR loci of reconstructed embryos were the same as donor cells.Embryos produced by inter-species nuclear transfer were performed by put human somatic cells into perivitelline space of enucleated rabbit oocytes.After electrofusion, we obtained 210 cloned embryos from 310 reconstructed embryos.Cloned embryos developed in vitro 2-cell embryos (188, 86.6%), 4-cell embryos (188, 86.6%), 8-cell embryos (188.86.6%), 16-cell embryos (188, 86.6%), morula (141, 65%), and blastocysts (81, 37. 3%), respectively.We selected 18 reconstructed embryos randomly for amplification by human hu-alpgj and rabbit ra-wap probes.Results showed 16 out of 18 reconstructed embryos were hu-alpgj (+) and the other two were hu-alpgj (-), and all the embryos were ra-wap (-). 10 selected embryos were identified for STR-DNA, and the results showed STR loci of those embryos were consistent with donor cells.Furthermore, we obtained reconstructed embryos of different disease (Alzheimer's Disease, Parkinson's Disease, Spinal muscular atrophy, Diabetes, Tumor, etc).STR loci of different disease reconstructed embryos were the same as donor cells.We also designed studies to explore gene expression associated development, DNA methylation, mitochondria, and telomerase activity.All above researches were complied with International Convention against the Reproduction Cloning of Human Beings which was formulated by the united nations at 2002 and Guiding Principles on the ethics of human embryonic stem cell research which was formulated by The Ministry of Science and Techonlogy of the People's Republic of China and Ministry of Health of the People's Republic of China strictly.Donor voluntarily donated oocytes, somatic cells with no financial payment.Donors signed comprehensive informed consent documents and were informed that all donated materials were to be used for research and not for reproductive purposes.

OBJECTIVE:To explore the effect of basic fibroblast growth factor 1 (bFGF1) during embryonic development on hematopoiesis, to study the expression of FGF1, vascular endothelial growth factor receptor (KDR), CD133, CD34 and transcription factors Ihh, SCL, GATA-1, GATA-2 and PU. 1 in the yolk sac, and to learn about the role and relationships of FGF1, hematopoietic cells and transcription factors during embryonic hematopoiesis.METHODS:10 microm sections and total RNA were prepared from 107 human embryos aged 3-12 weeks. Immunohischemical SP staining and RT-PCR were performed.RESULTS:The yolk sac blood islands of human 3 approximately 12 weeks embryos consisted of peripheral vascular endothelial cells and central hematopoietic cells. The expression of FGF1 was firstly found in visceral mesoderm around periphery of yolk sac blood island at day 16, while was little inside it. KDR was not or lowly expressed and CD34 and CD133 were not expressed then. The expression increased, gray value decreased and staining enhanced at day 21. Strong staining of CD34+, CD133+ and KDR+ cells were found in blood island and mesoderm at day 30, their gray values changed from 156 +/- 16, 173 +/- 18 and 160 +/- 14 to 53 +/- 7, 52 +/- 6 and 69 +/- 8 respectively. FGF1 expression was strong positive, the gray value declined dramatically from 161 +/- 13 to 40 +/- 5. Some positive cells formed vessel-like structure along the periphery of blood island. Moderate expression of CD34+, CD133+, KDR+ cells increased at day 45, the cells aggregated into mass in blood island and FGF1+ cells did the same in blood island, while little in mesoderm. Its gray valve was increased. After 7 weeks, CD133+, KDR+, CD34+ cells significantly decreased their gray values increased, the staining became week. FGF1 was weakly expressed in yolk sac and its gray value increased to 179 +/- 22. RT-PCR showed Ihh, SCL, GATA-1 and GATA-2 were expressed at different time in yolk sac. PU. 1 were not expressed at day 16, and then expressed.CONCLUSIONS:The hematopoietic properties of yolk sac may be dependent on signaling through FGF receptors and FGF1 plays an important role in hematopoietic stem cell homeostasis. The FGF pathway regulates primitive hematopoiesis by modulating transcription factors such as Gata1 expression level and activity.