OBJECTIVE: To explore and quantify the association of hot night exposure during the sperm development period (0-90 lag days) with semen quality. METHODS: A total of 6,640 male sperm donors from 6 human sperm banks in China during 2014-2020 were recruited in this multicenter study. Two indices (i.e., hot night excess [HNE] and hot night duration [HND]) were used to estimate the heat intensity and duration during nighttime. Linear mixed models were used to examine the association between hot nights and semen quality parameters. RESULTS: The exposure-response relationship revealed that HNE and HND during 0-90 days before semen collection had a significantly inverse association with sperm motility. Specifically, a 1 °C increase in HNE was associated with decreased sperm progressive motility of 0.0090 (95% confidence interval [ CI]: -0.0147, -0.0033) and decreased total motility of 0.0094 (95% CI: -0.0160, -0.0029). HND was significantly associated with reduced sperm progressive motility and total motility of 0.0021 (95% CI: -0.0040, -0.0003) and 0.0023 (95% CI: -0.0043, -0.0002), respectively. Consistent results were observed at different temperature thresholds on hot nights. CONCLUSION Our findings highlight the need to mitigate nocturnal heat exposure during spermatogenesis to maintain optimal semen quality.
Humans ; Male ; Semen Analysis ; Adult ; Sperm Motility ; Hot Temperature/adverse effects* ; China ; Middle Aged ; Spermatozoa/physiology* ; Young Adult

Bone morphogenetic proteins (BMPs) are multifunctional growth factors of the transforming growth factor β (TGF-β) superfamily. They regulate steroid secretion from mammalian granulosa cells, promote granulosa cell survival and proliferation, and inhibit follicular atresia, luteinization, and granulosa cell apoptosis, thereby promoting the development and maturation of mammalian follicles. At the same time, BMPs play an important role in embryonic morphogenesis, induction of uterine receptivity, and blastocyst attachment. This paper describes the effects of BMPs on mammalian follicular and embryonic development and the roles of BMPs in female reproduction, focusing on the process in which BMPs promote follicular maturation by regulating steroid secretion from granulosa cells during mammalian oocyte maturation. This review aims to provide a reference for further research on mammalian oocyte culture and improvement of reproductive efficiency in female animals.
Animals ; Embryonic Development/drug effects* ; Female ; Bone Morphogenetic Proteins/pharmacology* ; Reproduction/physiology* ; Humans ; Granulosa Cells/cytology* ; Oocytes

Given that ovarian stimulation is vital for assisted reproductive technology (ART) and results in elevated serum estrogen levels, exploring the impact of elevated estrogen exposure on oocytes and embryos is necessary. We investigated the effects of various ovarian stimulation treatments on oocyte and embryo morphology and gene expression using a mouse model and estrogen-treated mouse embryonic stem cells (mESCs). Female C57BL/6J mice were subjected to two types of conventional ovarian stimulation and ovarian hyperstimulation; mice treated with only normal saline served as controls. Hyperstimulation resulted in high serum estrogen levels, enlarged ovaries, an increased number of aberrant oocytes, and decreased embryo formation. The messenger RNA (mRNA)‍-sequencing of oocytes revealed the dysregulated expression of lysine-specific demethylase 6b (Kdm6b), which may be a key factor indicating hyperstimulation-induced aberrant oocytes and embryos. In vitro, Kdm6b expression was downregulated in mESCs treated with high-dose estrogen; treatment with an estrogen receptor antagonist could reverse this downregulated expression level. Furthermore, treatment with high-dose estrogen resulted in the upregulated expression of histone H3 lysine 27 trimethylation (H3K27me3) and phosphorylated H2A histone family member X (γ-H2AX). Notably, knockdown of Kdm6b and high estrogen levels hindered the formation of embryoid bodies, with a concomitant increase in the expression of H3K27me3 and γ-H2AX. Collectively, our findings revealed that hyperstimulation-induced high-dose estrogen could impair the demethylation of H3K27me3 by reducing Kdm6b expression. Accordingly, Kdm6b could be a promising marker for clinically predicting ART outcomes in patients with ovarian hyperstimulation syndrome.
Female ; Mice ; Demethylation/drug effects* ; Embryonic Stem Cells ; Estrogens/administration & dosage* ; Gene Expression/drug effects* ; Histones/metabolism* ; Jumonji Domain-Containing Histone Demethylases/metabolism* ; Mice, Inbred C57BL ; Oocytes ; Ovary/drug effects* ; Reproductive Techniques, Assisted ; Animals

Triclocarban (TCC) is a broad-spectrum antimicrobial widely used in various personal care products, textiles, and children's toys. TCC has potential reproductive and developmental toxicity in animals. However, little is known regarding the effect of TCC on human sperm function. In this study, an in vitro assay was used to investigate the effects of TCC on normal human spermatozoa and the possible underlying mechanisms involved. Semen from healthy male donors was collected and cultured in complete Biggers, Whitten and Whittingham (BWW) and low-sugar BWW media, followed by treatment with TCC at concentrations of 0, 0.1 µmol l -1 , 1 µmol l -1 , 10 µmol l -1 , and 100 µmol l -1 for 4 h. TCC was found to reduce the sperm total motility and progressive motility. Moreover, the sperm kinematic parameters, straight-line velocity (VSL), average path velocity (VAP), and curvilinear velocity (VCL) were affected in a dose-dependent manner. After treatment with TCC at the lowest effective concentration of 10 µmol l -1 , TCC caused a significant decrease in mitochondrial adenosine triphosphate (ATP) production and mitochondrial membrane potential (MMP) and a significant increase in reactive oxygen species (ROS), similar to the observations with the positive control carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP), suggesting that TCC may decrease sperm motility by affecting the oxidative phosphorylation (OXPHOS) pathway. In a sugar-free and low-sugar BWW culture environment, TCC enhanced the damaging effect on sperm motility and ATP, MMP, and lactate decreased significantly, suggesting that TCC may also affect the glycolytic pathway that supplies energy to spermatozoa. This study demonstrates a possible mechanism of TCC toxicity in spermatozoa involving both the OXPHOS and glycolysis pathways.
Male ; Sperm Motility/drug effects* ; Humans ; Carbanilides/pharmacology* ; Oxidative Phosphorylation/drug effects* ; Glycolysis/drug effects* ; Membrane Potential, Mitochondrial/drug effects* ; Adenosine Triphosphate/metabolism* ; Spermatozoa/metabolism* ; Reactive Oxygen Species/metabolism* ; Mitochondria/metabolism*

OBJECTIVE: To investigate the correlation of seminal plasma oxidation reduction potential (ORP), normalized oxidation-reduction potential (nORP) and sperm DNA fragmentation index (DFI) to sperm motion parameters, and their clinical predictive value for oligoasthenozoospermia (OAZ). METHODS: This study included 433 male subjects visiting the Clinic of Andrology in our hospital from March to May 2024. According to sperm concentration and the percentage of progressively motile sperm (PMS), we divided them into a normal control (n = 119), an oligozoospermia (OZ, n = 118), an athenozoospermia (AZ, n = 119) and an OAZ group (n = 77). Using the electrode method, we measured the seminal plasma ORP, calculated nORP=ORP/sperm concentration (mV/［10⁶/ml］), and determined DFI and high DNA chromatin sperm (HDS) by flow cytometry based on sperm chromatin structure assay (SCSA), followed by comparison among the four groups in age, abstinence days, semen volume, total sperm count, sperm concentration, PMS, non-progressively motile sperm (NPMS), immotile sperm (IMS), curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN), straightness(STR), wobble (WOB), DFI, HDS, ORP and nORP. Using the receiver operating characteristic (ROC) curve, we assessed the predictive value of DFI, ORP and nORP for OAZ, and analyzed the correlation of DFI, ORP and nORP to sperm motion parameters by Pearson and Spearman analyses. RESULTS: Statistical analysis revealed statistically significant differences among the four groups in semen volume, abstinence days, total sperm count, sperm concentration, PMS, NPMS, IMS, total sperm motility, VCL, VSL, VAP, STR, DFI, HDS, ORP and nORP (P < 0.05), but not in age, LIN and WOB (P > 0.05). The area under the ROC curve (AUC) for the predictive value of DFI for OAZ was 0.880, with the critical value of 8.920, sensitivity of 74.8% and specificity of 88.2%; that of ORP for AZ was 0.698, with the critical value of 155.375, sensitivity of 70.6% and specificity of 64.7%; and that of nORP for OZ was 0.999, with the critical value of 9.844, sensitivity of 98.3% and specificity of 99.2%. Pearson and Spearman correlation analyses showed that DFI was correlated positively with age, abstinence days, semen volume, IMS, HDS and ORP, but negatively with PMS, NPMS, total sperm motility, VCL, VSL, VAP and STR; ORP positively with abstinence days, semen volume, IMS, DFI and nORP, but negatively with PMS, NPMS, total sperm motility, VSL, LIN and STR; and nORP positively with HDS, but negatively with abstinence days, total sperm count, sperm concentration, PMS and NPMS. CONCLUSION Oxidative stress (OS) may be an important pathological factor for elevated ORP, increased DFI and changes of routine sperm motion parameters, consequently leading to OAZ. As OS markers, DFI and ORP have a high predictive value for OS-induced OAZ.
Male ; Humans ; DNA Fragmentation ; Semen/metabolism* ; Sperm Motility ; Spermatozoa ; Oxidation-Reduction ; Adult ; Oligospermia ; Sperm Count ; Semen Analysis ; Asthenozoospermia

OBJECTIVE: To explore the role of reactive oxygen species (ROS) and lactate dehydrogenase isoenzyme X (LDH-X) in the changes of sperm mitochondrial membrane potential (MMP) in infertility patients with varicocele (VC). METHODS: This study included 38 infertility patients with VC (VCinf), 35 non-VC infertile males (NVCinf), and 30 normal fertile men as controls. We obtained the routine semen parameters using the sperm quality analysis system, examined the contents of LDH-X in the seminal plasma and sperm with the automatic biochemical analyzer, measured the level of malondialdehyde (MDA) in seminal plasma by thiobarbituric acid (TBA) colorimetry, and determined the expressions of mitochondrial membrane potential (MMP) and LDH-X mRNA in the sperm using JC-1 fluorescence probe and RT-PCR. RESULTS: No statistically significant differences were observed among the three groups of subjects in age, semen pH value, semen volume and sperm concentration (P > 0.05). Compared with the normal fertile controls, the patients in the VCinf and NVCinf groups showed significantly decreased sperm motility (［52.36 ± 12.48］% vs ［34.74 ± 15.23］% vs ［25.76 ± 13.73］%, P< 0.05), percentage of progressively motile sperm (PMS) (［42.54 ± 13.58］% vs ［29.10 ± 14.17］% vs ［20.95 ± 12.33］%, P< 0.05), sperm LDH-X (［16.46 ± 5.47］ vs ［13.63 ± 4.50］ vs ［10.18 ± 3.00］ mU/106, P< 0.05), sperm MMP (［48.04 ± 11.62］% vs ［40.86 ± 12.69］% vs ［34.41 ± 13.93］%, P< 0.05) and expression of sperm LDH-X mRNA (P< 0.05). but increased seminal plasma LDH-X (［935.36 ± 229.48］ vs ［1241.05 ± 337.07］ vs ［1425.08 ± 469.35］ U/L, P< 0.05), seminal plasma/whole sperm LDH-X (［1.06 ± 0.35］ vs ［1.40 ± 0.34］ vs ［1.63 ± 0.66］, P< 0.05), and content of seminal plasma MDA (［1.10 ± 0.19］ vs ［1.59 ± 0.27］ vs ［2.00 ± 0.22］ nmol/ml, P< 0.05). CONCLUSION Excessive ROS in the reproductive system of VCinf patients reduces the content of MMP and causes the overflow of LDH-X out of sperm cells. Therefore the decrease of sperm LDH-X may be accompanied by that of MMP.
Humans ; Male ; Infertility, Male/etiology* ; Varicocele/metabolism* ; Adult ; Reactive Oxygen Species/metabolism* ; Spermatozoa/metabolism* ; L-Lactate Dehydrogenase/metabolism* ; Membrane Potential, Mitochondrial ; Isoenzymes/metabolism* ; Case-Control Studies ; Young Adult ; Mitochondrial Membranes/metabolism*

OBJECTIVE: The aim of this study is to analyze the clinical features and genetic etiology of a patient with multiple morphological abnormalities of the sperm flagella (MMAF) retrospectively. METHODS: A severely oligospermic patient from the Reproductive Center of the First Affiliated Hospital of Ningbo University was selected as the study subject. Clinical data and examination results were collected. High-throughput sequencing and bioinformatics were used to analyze the genetic etiology. And Sanger sequencing was employed to validate findings in the family. Transmission electron microscopy (TEM) was used to observe the sperm ultrastructure, and immunofluorescence analysis was performed to examine the localization of FSIP2 protein in the sperm. RESULTS: The patient presented with severe oligospermia, and sperm morphology displayed MMAF. TEM revealed fibrous sheath and 9+2 microtubule structural disruptions in the sperm. Sequencing identified compound heterozygous variants in the FSIP2 gene (c.17798C > T, c.5927T > G), inherited from the father and mother, respectively. According to the guidelines of the American College of Medical Genetics and Genomics, the variants were classified as pathogenic. The patient's spouse underwent intracytoplasmic single sperm injection, resulting in one embryo, but no clinical pregnancy occurred after embryo transfer. CONCLUSION This study reported the mutation of FSIP2 gene c.17798C > T, c.5927T > G in a patient with MMAF. These findings expand the mutational spectrum of the FSIP2 gene and provide insights for genetic and assisted reproductive counseling for patients with MMAF.
Humans ; Male ; Sperm Tail/pathology* ; Heterozygote ; Oligospermia/genetics* ; Spermatozoa ; Mutation ; Infertility, Male/genetics* ; Adult ; Pedigree ; Retrospective Studies ; Sperm Injections, Intracytoplasmic

OBJECTIVE: To assess the feasibility of first polar body transfer (PB1T) combined with preimplantation mitochondrial genetic testing for blocking the transmission of a pathogenic mitochondrial DNA 8993T>G mutation. METHODS: A Chinese family affected with Leigh syndrome which had attended the Reproductive Medicine Centre of the First Affiliated Hospital of Anhui Medical University in September 2021 was selected as the study subject. Controlled ovarian hyperstimulation was carried out for the proband after completing the detection of the mitochondrial DNA 8993T>G mutation load among the pedigree members. Mature MII oocytes were inseminated by intracytoplasmic sperm injection (ICSI), cultured in vitro for 5 to 6 days to the blastocyst stage, and trophoblastocytes were obtained by microbiopsy. Mitochondrial DNA testing (PGT-MT) and chromosomal aneuploidy (PGT-A) analyses were carried out after whole-genome amplification, and the embryos with zero mutation load were selected for transfer. Amniotic fluid and umbilical cord blood samples were collected during middle pregnancy and after birth respectively for mitochondrial DNA testing to verify the reliability of embryo screening. As an attempt, PB1 with good morphology of MII oocytes was selected for transfer into the enucleated oocytoplasm from healthy donors, followed by ICSI fertilization, blastocyst culture and PGT of embryos using the same procedure. This study has been approved by the Ethics Committee of the First Affiliated Hospital of Anhui Medical University (No. 2021zhyx-B12). RESULTS: An antagonist protocol was used for ovarian stimulation, and a total of 19 oocytes were obtained, of which 14 MII were fertilized by ICSI, and 2 had developed into blastocysts. PGT-MT was carried out on biopsied trophoblastocytes, in which the mitochondrial DNA 8993T>G mutation load was not detected in one embryo, the other was 100% mutated, and the mutation loads of the remaining unfertilized eggs and developmentally arrested embryos ranged from 0% ~ 100%, presenting a clear biased distribution. With fully informed consent, one PGT-MT zero mutation load blastocyst was transferred and clinical pregnancy was achieved. Mitochondrial DNA and chromosomal testing of amniotic fluid cells during middle pregnancy had revealed no abnormalities. The proband had delivered a healthy boy through Caesarean section at 39⁺⁵ weeks of gestation, and no mutation was detected in the cord blood sample. Five well-formed PBs from 14 eggs were selected for PB1 transfer, followed by ICSI and culture, and two of the reconstituted embryos had formed blastocysts, with none of the above mutations detected in the biopsied samples. CONCLUSION The PGT-MT technology can help families affected with mitochondrial diseases to have healthy offspring. PB1 transfer in combination with ICSI and PGT-MT holds the promise of turning waste into treasure and providing an alternative means of fertility for such families.
Humans ; Preimplantation Diagnosis/methods* ; Female ; DNA, Mitochondrial/genetics* ; Genetic Testing/methods* ; Pregnancy ; Mitochondrial Diseases/genetics* ; Polar Bodies ; Adult ; Feasibility Studies ; Sperm Injections, Intracytoplasmic/methods* ; Embryo Transfer/methods* ; Mutation ; Male ; Blastocyst/metabolism* ; Pedigree

Epigenetics is the link between the genome and environment, which can respond to physiological (such as age) or environmental factors (such as diet, stress, and pollution) and induce changes in epigenetic modifications (such as DNA methylation, non-coding RNA, and histone modifications). It can also serve as cellular memory transmitted from generation to generation. Sperm is highly responsive to such environmental changes and has unique epigenetic profiles. The paternal inter-/trans-generational inheritance mediated by sperm epigenetic changes is closely related to the health of offspring, which is an issue of great concern. This review has summarized the epigenetic mechanisms of paternal inter-/trans-generational inheritance and recent studies on the paternal inheritance mediated by sperm epigenetic changes in human and mice, which may facilitate understanding of the relationship between paternal epigenetic changes and the health of offspring caused by physiological or environmental changes and provide a basis for genetic counseling and clinical intervention.
Epigenesis, Genetic ; Humans ; Male ; Animals ; Spermatozoa/metabolism* ; DNA Methylation ; Paternal Inheritance ; Mice

OBJECTIVE: To investigate the association between SPAG17 gene variant and Familial severe asthenozoospermia, and to assess its impact on the outcome of intracytoplasmic sperm injection (ICSI). METHODS: Two siblings (Probands 1 and 2) with severe asthenozoospermia from a Chinese family who presented at the Reproductive Medicine Center II of Gansu Maternity and Child Health Care Hospital (Gansu Provincial Central Hospital) in May 2023 were selected as study subjects. Clinical data were collected, and sperm morphology and ultrastructure (assessed by transmission electron microscopy) were analyzed. Pathogenic variants were screened using whole exome sequencing (WES) and verified by Sanger sequencing. This study was approved by the Medical Ethics Committee of Gansu Maternity and Child Health Care Hospital (Ethics No.: 2023GSFYLS78). RESULTS: Probands 1 and 2 had primary infertility for 10 and 3 years, respectively, and both exhibited normal semen concentration, but the percentage of progressive motile sperm (PR) was significantly lower than the normal reference value (> 32.00%), measuring 2.33% ± 0.58% and 0.80% ± 0.45%, respectively. Additionally, the percentage of sperms with normal morphology was slightly below the reference range (> 4.00%), with the values of 3.36% ± 0.35% and 2.93% ± 1.36%. Both probands were found to harbor homozygous c.2188C>T (p.Q730*) nonsense variant of the SPAG17 gene (NM_206996.4), for which their mother was a heterozygous carrier (their father had already deceased). Both sibs underwent ICSI treatment using a long gonadotropin-releasing hormone agonist protocol during the follicular phase combined with assisted oocyte activation (AOA). The wife of Proband 1 ultimately gave birth to a healthy girl, whilst the wife of Proband 2 delivered two healthy girls. CONCLUSION The homozygous c.2188C>T (p.Q730*) nonsense variant of the SPAG17 gene is closely related with the severe asthenozoospermia phenotype. Live births can be achieved through ICSI combined with AOA technology, though the overall utilizable embryo rate may be relatively low.
Humans ; Male ; Asthenozoospermia/genetics* ; Adult ; Sperm Injections, Intracytoplasmic ; Pedigree ; Spermatozoa ; Female ; Exome Sequencing