Single-cell RNA sequencing reveals the effects of high-fat diet on oocyte and early embryo development in female mice.

BACKGROUND: Obesity is a global health issue with detrimental effects on various human organs, including the reproductive system. Observational human data and several lines of animal experimental data suggest that maternal obesity impairs ovarian function and early embryo development, but the precise pathogenesis remains unclear. METHODS: We established a high-fat diet (HFD)-induced obese female mouse model to assess systemic metabolism, ovarian morphology, and oocyte function in mice. For the first time, this study employed single-cell RNA sequencing to explore the altered transcriptomic landscape of preimplantation embryos at different stages in HFD-induced obese mice. Differential gene expression analysis, enrichment analysis and protein-protein interactions network analysis were performed. RESULTS: HFD-induced obese female mice exhibited impaired glucolipid metabolism and insulin resistance. The ovaries of HFD mice had a reduced total follicle number, an increased proportion of atretic follicles, and irregular granulosa cell arrangement. Furthermore, the maturation rate of embryonic development by in vitro fertilization of oocytes was significantly decreased in HFD mice. Additionally, the transcriptional landscapes of preimplantation embryos at different stages in mice induced by different diets were significantly distinguished. The maternal-to-zygotic transition was also affected by the failure to remove maternal RNAs and to turn off zygotic genome expression. CONCLUSIONS: HFD-induced obesity impaired ovarian morphology and oocyte function in female mice and further led to alterations in the transcriptional landscape of preimplantation embryos at different stages of HFD mice.

Endoplasmic reticulum stress-mediated ferroptosis in granulosa cells contributes to follicular dysfunction of polycystic ovary syndrome driven by hyperandrogenism.

RESEARCH QUESTION: Does hyperandrogenaemia affect the function of ovarian granulosa cells by activating ferroptosis, and could this process be regulated by endoplasmic reticulum stress? DESIGN: Levels of ferroptosis and endoplasmic reticulum stress in granulosa cells were detected in women with and without polycystic ovary syndrome (PCOS) undergoing IVF. Ferroptosis and endoplasmic reticulum stress levels of ovarian tissue and follicle development were detected in control mice and PCOS-like mice models, induced by dehydroepiandrosterone. An in-vitro PCOS model of KGN cells was constructed with testosterone and ferroptosis inhibitor Fer-1. Endoplasmic reticulum stress inhibitor, tauroursodeoxycholate (TUDCA), determined the potential mechanism associated with excessive induction of ferroptosis in granulosa cells related to PCOS, and levels of ferroptosis and endoplasmic reticulum stress were detected. RESULTS: Activation of ferroptosis and endoplasmic reticulum stress occurred in granulosa cells of women with PCOS and the varies of PCOS-like mice. The findings in KGN cells demonstrated that testosterone treatment results in elevation of oxidative stress levels, particularly lipid peroxidation, and intracellular iron accumulation in granulosa cells. The expression of genes and proteins associated with factors related to ferroptosis, mitochondrial membrane potential and ultrastructure showed that testosterone activated ferroptosis, whereas Fer-1 reversed these alterations. During in-vitro experiments, activation of endoplasmic reticulum stress induced by testosterone treatment was detected in granulosa cells. In granulosa cells, TUDCA, an inhibitor of endoplasmic reticulum stress, significantly mitigated testosterone-induced ferroptosis. CONCLUSIONS: Ferroptosis plays a part in reproductive injury mediated by hyperandrogens associated with PCOS, and may be regulated by endoplasmic reticulum stress.

Preliminary Screening and Study of Key Gene Expression in Endometrial Window Period.

Background: Implantation is a highly coordinated event involving both embryonic and endometrial participation. The endometrium expresses a complex array of proteins during the menstrual cycle many of which help to define a period of receptivity collectively known as the "window of implantation." Objective: Using high-throughput RNA sequencing technology analysis to find differentially expressed genes before and after the endometrial window, and search for key marker genes of the membrane implantation window. Design: This was a retrospective study. Setting: This study was performed in the Department of Obstetrics and Gynecology, Taizhou People's Hospital. Participants: Fifty patients with repeated implantation failure in in vitro fertilization were selected and were divided into (1) the normal window group (36 cases); (2) the window forward group (8 cases); and (3) the window backward group (6 cases) based on endometrial biopsy findings. Interventions: Using RNA sequencing technology combined with biological information analysis tools to analyze the differentially-expressed genes in 9 samples. Gene Ontology databases were used for the functional annotation of these differentially-expressed genes. Kyoto Encyclopedia of Genes and Genomes analysis was used to draw a signal path diagram. Primary Outcome Measures: (1) Screening of differentially-expressed genes and (2) functional analysis of the differential genes. Results: A total of 22 differentially-expressed genes related to endometrial receptivity were obtained by transcriptome sequencing. Seven of the 22 differentially-expressed genes have been shown to have a close relationship with the endometrial receptive window period. Further, it was proved that the Wnt signaling pathway and mitogen-activated protein kinase signaling pathway were closely related to endometrial receptivity. Conclusions: The present study identified a series of key genes and pathways that may be involved in the endometrial window period, providing an experimental and theoretical basis for exploring the personalized embryo transfer program.

Accuracy in predicting soft tissue changes of orthodontic class III cases using Dolphin® software.

OBJECTIVES: The prediction of posttreatment outcomes is conducive to the final determination of ideal therapeutic options. However, the prediction accuracy in orthodontic class III cases is unclear. Therefore, this study conducted exploration on prediction accuracy in orthodontic class III patients using the Dolphin® software. MATERIALS AND METHODS: In this retrospective study, lateral cephalometric radiographs of pre- and posttreatment were collected from 28 angle class III adults who received completed non-orthognathic orthodontic therapy (8 males, 20 females; mean age = 20.89 ± 4.26 years). The values of 7 posttreatment parameters were recorded and inserted into the Dolphin® Imaging software to generate a predicted outcome, and then the prediction radiograph and actual posttreatment radiograph were superimposed and compared in terms of soft tissue parameters and landmarks. RESULTS: The prediction showed significant differences with the actual outcomes in nasal prominence (the difference between the prediction and the actual value was - 0.78 ± 1.82 mm), the distance from the lower lip to the H line (0.55 ± 1.11 mm), and the distance from the lower lip to the E line (0.77 ± 1.62 mm) (p < 0.05). Point subnasale (Sn) (an accuracy of 92.86% in the horizontal direction and 100% in the vertical direction in 2 mm) and point soft tissue A (ST A) (an accuracy of 92.86% in the horizontal direction and 85.71% in the vertical direction in 2 mm) were proven to be the most accurate landmarks, while the predictions in the chin region were relatively inaccurate. Furthermore, the predictions in the vertical direction were of higher accuracy compared to the horizontal direction except for the points around the chin. CONCLUSIONS: The Dolphin® software demonstrated acceptable prediction accuracy in midfacial changes in class III patients. However, there were still limitations for changes in the chin and lower lip prominence. CLINICAL RELEVANCE: Clarifying the accuracy of Dolphin® software in predicting soft tissue changes of orthodontic class III cases will facilitate physician-patient communication and clinical treatment.

Icariside II suppresses the tumorigenesis and development of ovarian cancer by regulating miR-144-3p/IGF2R axis.

Ovarian cancer is one of the three major gynecological malignancies. It has been reported that Icariside II was able to block the occurrence and development of ovarian cancer. However, the detailed mechanism by which Icariside II regulates the development of ovarian cancer is widely unknown. EdU staining and transwell assays were applied to detect the proliferation, migration, and invasion of ovarian cancer cells. Next, the relationship between miR-144-3p and IGF2R was verified by the dual-luciferase reporter assay. Moreover, in vivo animal model was constructed to verify the effect of Icariside II on the development of ovarian cancer. Icariside II notably inhibited the proliferation, migration, and invasion and induced the apoptosis of ovarian cancer cells. Additionally, Icariside II markedly increased the level of miR-144-3p in ovarian cancer cells. Moreover, IGF2R was targeted by miR-144-3p directly. Icariside II significantly decreased the expression of IGF2R and the phosphorylation level of AKT and mTOR in ovarian cancer cells, which were partially reversed by miR-144-3p inhibitor. Meanwhile, Icariside II remarkably promoted the autophagy of ovarian cancer cells, as confirmed by the increased expression of Beclin-1 and ATG-5 and decreased expression of p62; however, co-treatment with miR-144-3p inhibitor notably decreased autophagy. Furthermore, the result of animal study suggested Icariside II notably inhibited ovarian tumor growth as well. Collectively, Icariside II could suppress the tumorigenesis and development of ovarian cancer by promoting autophagy via miR-144-3p/IGF2R axis. These results may be beneficial for future studies on the use of Icariside II to treat ovarian cancer.

LonP1 regulates mitochondrial network remodeling through the PINK1/Parkin pathway during myoblast differentiation.

Myoblast differentiation is a crucial process for myogenesis. Mitochondria function as an energy-providing machine that is critical to this process, and mitochondrial dysfunction can prevent myoblasts from fusing into myotubes. However, the molecular mechanisms underlying the dynamic regulation of mitochondrial networks remain poorly understood. In the present study, we found that the PTEN induced kinase 1 (PINK1)/Parkin (an E3 ubiquitin-protein ligase) pathway is activated at the early stage of myoblast differentiation. Moreover, downregulation of mitofusin 2 (Mfn2) and increased dynamin-related protein 1 (Drp1) resulted in loosely formed mitochondria during this period. Furthermore, selective knockdown of the mitochondrial matrix protein Lon peptidase-1 (LonP1) at the early stage of myoblast differentiation induced mitochondrial depolarization and suppressed the PINK1/Parkin pathway and reduced Mfn2 and Drp1 levels, which blocked mitochondrial remodeling and myoblast differentiation. Overall, these data demonstrate that LonP1 promotes myoblast differentiation by regulating PINK1/Parkin-mediated mitochondrial remodeling.

Curcumin improves asthenozoospermia by inhibiting reactive oxygen species reproduction through nuclear factor erythroid 2-related factor 2 activation.

We conducted this study for the purpose of evaluating the protective mechanisms of curcumin against oxidative stress in asthenozoospermic individuals. Asthenozoospermic individuals were grouped into AS group, curcumin treatment group and brusatol + curcumin treatment group. The sperm motility was measured by computer-aided sperm analysis. We conducted flow cytometry and spectrophotometry to assess the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Chlortetracycline (CTC) was used to examine the acrosomal reaction of spermatozoa. Also, Western blotting was carried to measure antioxidant gene Nrf2 (nuclear factor erythroid 2-related factor) expression level. As our results shown, treatment with curcumin significantly decreased ROS formation and MDA production, compared with spermatozoa of AS group; however, Nrf2 inhibitor, Brusatol, inhibited Nrf2 expression and sperm function. Our results have shown that curcumin might protect spermatozoa by regulating Nrf2 level.

Yap regulates mitochondrial structural remodeling during myoblast differentiation.

Yes-associated protein (Yap) is a core transcriptional coactivator in the downstream Hippo pathway that regulates cell proliferation and tissue growth. However, its role in the regulation of myoblast differentiation remains unclear. Regulation of mitochondrial networks by dynamin-related protein 1 (Drp1) and mitofusion 2 (Mfn2) is crucial for the activation of myoblast differentiation. In the present study, we investigated the interplay between the Hippo/Yap pathway and protein contents of Mfn2 and Drp1 during myoblast differentiation. The Hippo/Yap pathway was inactivated at the early stage of myoblast differentiation due to the decreased ratio of phosphorylated mammalian sterile 20 kinases 1/2 (p-Mst1/2) to Mst1/2, phosphorylated large tumor suppressor 1 (p-Lats1) to Lats1, and phosphorylated Yap (serine 112, p-Yap S112) to Yap, which resulted in the translocation of Yap from cytoplasm to nucleus, increased protein content of Drp1, and mitochondrial fission events. Downregulation of Yap inhibited myoblast differentiation and decreased the content of Drp1, which resulted in elongated mitochondria, fused mitochondrial networks, and collapsed mitochondrial membrane potential. Together, our data indicate that inactivation of the Hippo/Yap pathway could induce mitochondrial fission by promoting Drp1 content at the early stage of myoblast differentiation.

UCP2 Mitigates the Loss of Human Spermatozoa Motility by Promoting mROS Elimination.

BACKGROUND/AIMS: To demonstrate the function of uncoupling protein 2 (UCP2) in the regulation of human spermatozoa motility. METHODS: Semen samples were collected from donors with either normal spermatozoa motility (normospermia [NS]) or poor spermatozoa motility (asthenospermia [AS]). UCP2 protein in spermatozoawas quantified by Western blotting. The level of mitochondrial reactive oxygen species (mROS) was evaluated by MitoSOX Red. The activity of mitochondrial membrane potential (MMP) in spermatozoa was evaluated by a JC-1 assay and the ATP level was monitored by a luciferin-luciferase assay. RESULTS: UCP2 was expressed in both NS and AS groups, with the former exhibiting a higher level than the latter. Immunofluorescence analysis shows that UCP2 is mainly located at the mid-region of human spermatozoa. The inhibition of UCP2 by a highly selective inhibitor, Genipin, results in not only impaired spermatozoa mobility (P<.05) but also an elevated level of mROS (P<.05), suggesting that UCP2 is involved in the maintenance of the spermatozoa mobility, which probably is achieved by promoting mROS elimination. Furthermore, H2O2 treatment of spermatozoa increases the mROS level coupled with the loss of spermatozoa mobility. Unexpectedly, this treatment also has a positive impact on the expression of UCP2 within a certain range of supplemental H2O2, indicating the moderate mROS level possibly serves as a feedback signal to stimulate the expression of UCP2. Finally, the treatment of spermatozoa by an ROS scavenger, N-acetyl-l-cysteine (NAC),decreases the level of mROS and increases the curvilinear velocity (VCL) of spermatozoa, but the UCP2 level is not affected. CONCLUSION: These results suggest an UCP2-mROS-motility regulatory system exists for maintaining spermatozoa mobility in humans. In such a system, UCP2 fulfills its function by promoting mROS elimination, and slightly over-produced mROS in turn serves as a signal to stimulates the expression of UCP2. This regulatory system represents a new potential target for the discovery of novel pharmaceuticals for the treatment of patients with low spermatozoa motility.

Effects of Folpet, Captan, and Captafol on Human Aromatase in JEG-3 Cells.

BACKGROUND: Estradiol, produced by aromatase (CYP19A1), is very important for reproduction. Folpet, captan, and captafol belong to the phthalimide class of fungicides. They are used to protect the leaves of plants or fruits. They could be endocrine disruptors and may disrupt CYP19A1 activity. METHODS: In the present study, we investigated the effects of folpet, captan, and captafol on estradiol production and human CYP19A1 activity in JEG-3 cells. RESULTS: Folpet, captan, and captafol decreased estradiol production in JEG-3 cells in a concentration-dependent manner. Folpet, captan, and captafol inhibited human CYP19A1 with inhibitory concentration (IC50) values of 3.55, 10.68, and 1.14 µmol/L respectively. These chemicals competitively inhibited human CYP19A1. Molecular docking simulation analysis showed that they tended to bind to the steroid-binding pocket of the CYP19A1. However, the required concentrations may not be relevant to the negligible systemic exposures in humans to these chemicals. CONCLUSION: Folpet, captan, and captafol are potential inhibitors of human CYP19A1.

Leukemia inhibitory factor stimulates steroidogenesis of rat immature Leydig cells via increasing the expression of steroidogenic acute regulatory protein.

Leukemia inhibitory factor (LIF) has many physiological roles. However, its effects on Leydig cell development are still unclear. Rat immature and adult Leydig cells were cultured with different concentrations of LIF alone or in combination with luteinizing hormone (LH) for 24 h. LIF (1 and 10 ng/ml) significantly increased androgen production in immature Leydig cells, but had no effects on testosterone production in adult Leydig cells. Further studies revealed that LIF dose-dependently increased Star and Hsd17b3 expression levels in immature Leydig cells. Gene microarray revealed that the upregulation of anti-oxidative genes and Star might contribute to LIF-induced androgen production. In conclusion, LIF has stimulatory effects on androgen production in rat immature Leydig cells.

The effect of protein supplement concentration in embryo transfer medium on clinical outcome of IVF/ICSI cycles: a prospective, randomized clinical trial.

The aim of this prospective, randomized clinical trial (RCT) was to evaluate whether the supplemental protein concentration in embryo transfer (ET) medium affects the clinical outcomes in IVF-ET. A total of 750 patients undergoing IVF-ET who met the inclusion criteria were randomly divided into three groups, according to the concentration of synthetic serum substitute (SSS) in ET medium as follows: 10% (Group A), 20% (Group B) and 50% (Group C). The patient characteristics and embryology data were all similar among the groups. The rates of implantation, clinical pregnancy and live birth were compared. Clinical pregnancy (44.61%, 48.79% and 45.49%), multiple pregnancy (24.18%, 28.71% and 25.0%), implantation (28.21%, 30.68% and 29.86%) and live birth (41.67%, 43.96% and 41.70%) rates in the three groups (A, B and C, respectively) showed no significant differences. This RCT demonstrates that supplemental protein concentration in the ET medium does not affect the treatment outcomes in IVF-ET. There was no statistical evidence to support the hypothesis that supplemental protein concentration in the ET medium influences treatment outcomes in IVF-ET.

Prenatal diagnosis of single gene disorders using amniotic fluid as the starting material for PCR.

A rapid and inexpensive method for fetal genetic diagnosis using amniotic fluid (AF) as the starting material was demonstrated in this study. Raw AF was added directly to polymerase chain reaction (PCR) mixtures with HpH buffer (a high pH buffer), without any pre-treatment. Amplified products were detected by gel electrophoresis and then subjected to Sanger sequencing. The AF from four fetuses, each expressing a single gene disorder (achondroplasia, hypochondroplasia, thanatophoric dysplasia, or X-linked hypohidrotic ectodermal dysplasia), were analyzed. DNA fragments of different lengths were efficiently amplified from 8 µl of AF, allowing each of these single gene disorders to be successfully diagnosed. Although the amplification efficiency of the AF-PCR method is comparable to that of the Chelex method, the amount of the AF sample required was considerably lower than that required for the Chelex method (10 ml). This proposed method of diagnosis is more efficient, simpler, and less expensive, and reduces the chance of cross-contamination relative to the Chelex method, which requires purified DNA or other pre-treatment processes. Our method offers a promising tool that can be used for the diagnosis of various gene disorders in fetuses.

Blastocyst-stage versus cleavage-stage embryo transfer in the first frozen cycles of OHSS-risk patients who deferred from fresh embryo transfer.

Elective cryopreservation of all embryos has been the most effective means to avoid developing ovarian hyperstimulation syndrome (OHSS). However, it is still unknown which stage is optimal for freezing and transferring into uterus in OHSS-risk patients. This study was undertaken to evaluate whether OHSS-risk patients could benefit from transferring blastocysts. A total of 162 women were allocated to cleavage-stage embryo transfer (ET) (group A = 70) and blastocysts transfer (group B = 92) on the basis of patients' voluntary in their first frozen cycles. Although the mean number of transferred embryos in group A was significantly more than those in group B (2.37 ± 0.52 versus 2.11 ± 0.52, p < 0.05), the clinical pregnancy rates, implantation rates and live birth rates in group B were significantly higher than those in group A (47.83% versus 31.43%, p < 0.05; 31.44% versus 18.67%, p < 0.05; 40.21% versus 27.14%, p < 0.05), and the multiple pregnancy rates in both groups were comparable (34.09% versus 36.36%, p > 0.05). The observed results in OHSS-risk population allow us to take a position in favor of blastocyst transfer, thus pregnancy and live birth could be achieved with fewer ETs and in a shorter time frame.

Live birth following vitrification of in vitro matured oocytes derived from sibling smaller follicles at follicle selection phase in the context of in vitro fertilization.

In ovarian stimulation, a 31-year-old woman with polycystic ovary syndrome was at the risk of developing ovarian hyperstimulation syndrome, follicle aspiration was performed, and eight immature oocytes were collected from follicle fluids. After 28 h in vitro culture, six of them reached MII and were vitrified. The patient failed to conceive in her fresh in vitro fertilization cycle and next two replacement cycles. In the third replacement cycle, a successful pregnancy was obtained by vitrified-thawed oocytes. This case demonstrates that follicular aspiration during follicle selection phase has protective effects against developing ovarian hyperstimulation syndrome, and rescued immature oocytes are viable and could produce promising embryos for live birth.

Chronic hepatitis B virus infection in women is not associated with IVF/ICSI outcomes.

OBJECTIVE: This study was to evaluate whether chronic HBV (Hepatitis B virus) infection in women is associated with poor performance following IVF/ICSI (in vitro fertilization/intracytoplasmic sperm injection) treatments. MATERIALS AND METHODS: 123 cycles with female chronic HBV infection were compared with 246 cycles with no-infected couples, matched for female age, D3 serum FSH (follicles stimulation hormone) levels, body mass index and assisted reproductive technology approach used (IVF or ICSI), in a ratio of 1:2. RESULTS: The details in IVF/ICSI cycles, including the dosage of gonadotrophin used, the serum estradiol levels and the endometrial thickness on the day of hCG (human chorionic gonadotrophin) injection, the mean number of oocytes retrieved, and the embryology data, were similar among seropositive and seronegative women. And there was no significant differences in implantation rates and live birth rates between seropositive women group and matched control (30.52 versus 28.34% per transfer; 42.28 versus 40.65%). CONCLUSIONS: The results indicated that women with chronic HBV infection is not associated with outcomes of IVF/ICSI treatments.

Correlation between ovarian follicular development and Hippo pathway in polycystic ovary syndrome.

BACKGROUND: For women of childbearing age, the biggest problem caused by polycystic ovary syndrome (PCOS) is infertility, which is mainly caused by anovulation, abnormal follicular development, proliferation of small antral follicles, and cystic follicles. The mechanism underlying its occurrence is not clear. The abnormal proliferation and development of follicles in PCOS patients is a complex process, which is affected by many factors. The objective of this study was to investigate the relationship between the Hippo pathway and follicular development in PCOS, and to further explore this relationship by using the YAP inhibitor verteporfin (VP). METHOD: 30 3-week-old BALB/C female rats were randomly divided into control group (n = 10), DHEA group (n = 10) and DHEA + VP group (n = 10). The morphology of ovary and the degree of follicular development were observed by HE staining, and the expression and location of AMH in ovarian follicles were observed by immunofluorescence. The ovarian reserve function index AMH, cell proliferation index PCNA and the ratio of Hippo pathway related proteins MST, LATS, YAP, P-YAP and P-YAP/YAP were detected by Western blot. RESULTS: After dividing 30 3-week-old female mice into control, dehydroepiandrosterone (DHEA; model of PCOS), and DHEA + VP groups, we found that the number of small follicles increased in the DHEA group compared to the control group. Additionally, in the DHEA group compared to the control group, anti-müllerian hormone (AMH; ovarian reserve index) increased, proliferating cell nuclear antigen (PCNA; cell proliferation index) decreased, and upstream (MST and LATS) and downstream (YAP and p-YAP) proteins in the Hippo pathway increased, though the p-YAP/YAP ratio decreased. VP ameliorated the increases in AMH, MST, LATS, YAP and p-YAP, but did not ameliorate the decrease in the p-YAP/YAP ratio. CONCLUSIONS: This study indicates that the increased small follicles in the ovaries and changes in ovarian reserve and cell proliferation may be closely related to Hippo pathway activation. This suggests that the Hippo pathway may be an important pathway affecting the proliferation and development of follicles and the occurrence of PCOS.

CISD2 regulates oxidative stress and mitophagy to maintain the balance of the follicular microenvironment in PCOS.

OBJECTIVES: To observe the CISD2 expression among PCOS patients and to explore its profound impact on the follicular microenvironment. Moreover, we want to elucidate the intricate mechanistic contribution of CISD2 to the onset and progression of PCOS. METHODS: Oxidase NOX2, mitophagy-related proteins, and CISD2 were detected by WB. The changes in mitochondrial structure and quantity were observed by transmission electron microscopy. Mitochondrial and lysosome colocalization was used to detect the changes of mitophagy. MDA kit, GSH and GSSG Assay kit and ROS probe were used to detect oxidative stress damage. RESULTS: We found that CISD2, mitophagy and oxidase in the GCs of PCOS patients were significantly increased. Testosterone stimulation leads to the increase of oxidase, mitophagy, and CISD2 in KGN cells. CISD2 inhibition promoted the increase of mitophagy, and the activation of mitochondria-lysosome binding, while alleviating the oxidative stress. CONCLUSIONS: Inhibition of CISD2 can improve the occurrence of oxidative stress by increasing the level of mitophagy, thus affecting the occurrence and development of PCOS diseases.

Evaluation of microRNA expression profiles in human sperm frozen using permeable cryoprotectant-free droplet vitrification and conventional methods.

For sperm cryopreservation, the conventional method, which requires glycerol, has been used for a long time. In addition, the permeable cryoprotectant-free vitrification method has been continuously studied. Although the differences of cryopreservation effects between the two methods have being studied, differences in microRNA (miRNA) profiles between them remain unclear. In this study, we investigated the differences in miRNA expression profiles among conventional freezing sperm, droplet vitrification freezing sperm and fresh human sperm. We also analyzed the differences between these methods in terms of differentially expressed miRNAs (DEmiRs) related to early embryonic development and paternal epigenetics. Our results showed no significant differences between the cryopreservation methods in terms of sperm motility ratio, plasma membrane integrity, DNA integrity, mitochondrial membrane potential, acrosome integrity, and ultrastructural damage. However, sperm miRNA-sequencing showed differences between the two methods in terms of the numbers of DEmiRs (28 and 19 with vitrification using a nonpermeable cryoprotectant and the conventional method, respectively) in postthaw and fresh sperm specimens. DEmiRs related to early embryonic development and paternal epigenetics mainly included common DEmiRs between the groups. Our results showed that the differences between conventional freezing and droplet vitrification were minimal in terms of miRNA expression related to embryonic development and epigenetics. Changes in sperm miRNA expression due to freezing are not always detrimental to embryonic development. This study compared differences in miRNA expression profiles before and after cryopreservation between cryopreservation by conventional and vitrification methods. It offers a new perspective to evaluate various methods of sperm cryopreservation.

[Suppression of mitochondrial oxidative phosphorylation on in vitro maturation, fertilization and developmental competence of oocytes].

OBJECTIVE: To investigate the roles of mitochondrial oxidative phosphorylation (OXPHOS) capacity in oocyte maturation, fertilization and embryo development. METHODS: Carbonyl cyanide p- (tri-fluromethoxy) phenyl-hydrazone (FCCP), a metabolic inhibitor of mitochondria, was introduced into culture medium. The integrity of spindle and chromosome alignment, reactive oxygen species (ROS) levels, and rates of maturation, germinal vesicle breakdown, fertilization and blastulation were assessed in vitro. RESULTS: Significant decreases were detected in the percentages of oocytes with nuclear maturation, normal spindle formation and chromosome alignment, ROS levels and capable for blastocyst formation between oocytes treated with FCCP and non-treated (control group), 55.8%, 37.9%, 0.67 and 57.9% (FCCP 10 nmol/L group), 47.3%,34.7%, 0.59 and 41.8% (FCCP 100 nmol/L group) versus 62.9%, 61.9%,0.94 and 68.3% (control group) respectively, P<0.05. However, No significant differences were found in the rates of GVBD and fertilization in oocytes from the FCCP treated and the control. CONCLUSION: Inhibition of mitochondrial metabolic capacity resulted in decreased the percentages of oocytes with nuclear maturation, normal spindle formation and chromosome alignment, ROS levels and capable for blastocyst formation. But the treatment of FCCP did not affect the rate of fertilization.