An all-37 °C thawing method improves the clinical outcomes of vitrified frozen-thawed embryo transfer: a retrospective study using a case-control matching analysis.

PURPOSE: The purpose of this study is to assess the impact of different temperatures and incubation times on the clinical outcomes of FET cycles during the thawing procedure and to select a better thawing method to improve clinical outcomes. METHODS: This retrospective study included 1734 FET cycles from January 1, 2020, to January 30, 2022. Embryos vitrified using a KITAZATO Vitrification Kit were thawed at 37 °C in all steps (the case group, denoted the "all-37 °C" group) or at 37 °C and then at room temperature (RT; the control group, denoted the "37 °C-RT" group), according to the kit instructions. The groups were matched 1:1 to avoid confounding. RESULTS: After case-control matching, 366 all-37 °C cycles and 366 37 °C-RT cycles were included. The baseline characteristics were similar (all P > 0.05) between the two groups after matching. FET of the all-37 °C group yielded a higher clinical pregnancy rate (CPR; P = 0.009) and implantation rate (IR; P = 0.019) than FET of the 37 °C-RT group. For blastocyst transfers, the CPR (P = 0.019) and IR (P = 0.025) were significantly higher in the all-37 °C group than in the 37 °C-RT group. For D3-embryo transfers, the CPR and IR were non-significantly higher in the all-37 °C group than in the 37 °C-RT group (P > 0.05). CONCLUSIONS: Thawing vitrified embryos at 37 °C in all steps with shortening wash time can enhance CPR and IR in FET cycles. Well-designed prospective studies are warranted to further evaluate the efficacy and safety of the all-37 °C thawing method.

Paternal Subclinical Hypothyroidism Affects the Clinical Outcomes of In Vitro Fertilization/Intracytoplasmic Sperm Injection.

Background: Maternal subclinical hypothyroidism (SCH) is a risk factor for adverse pregnancy outcomes. However, it is still unclear whether SCH affects male fertility. The aim of this study was to determine the association between paternal SCH and clinical outcomes after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). Methods: This retrospective study included 2511 couples with paternal euthyroidism (n = 2282) or SCH (n = 229) who visited our clinic for infertility treatment between April 1, 2017, and September 30, 2019. The primary outcomes were the fertilization rate and clinical pregnancy rate; the secondary outcomes were the good-quality embryo rate, blastocyst formation rate, implantation rate, and early miscarriage rate. These outcomes were compared between the euthyroid and the SCH groups after adjusting for various potential confounders. Results: The mean paternal ages in the euthyroid and SCH groups were 34.5 and 36.0 years, respectively (p = 0.002). Semen parameters and sperm DNA fragmentation index were similar between the two groups (all p > 0.05). The adjusted fertilization (0.69 vs. 0.71, p = 0.30), good-quality embryo (0.49 vs. 0.52, p = 0.31), blastocyst formation (0.51 vs. 0.53, p = 0.57), and early miscarriage (0.11 vs. 0.10, p = 0.81) rates were also similar between the two groups. There was a significantly decreased adjusted clinical pregnancy rate [confidence interval, CI] and implantation rate [CI] in the paternal SCH group compared with the euthyroid group (0.32 [0.26-0.40] vs. 0.42 [0.40-0.45], p = 0.009 for the clinical pregnancy rate; 0.24 [0.19-0.29] vs. 0.29 [0.27-0.31], p = 0.037 for the implantation rate). Stratified analysis indicated that these differences were only significant in men aged ≥35 years (p = 0.009 and 0.022, respectively) and not in men <35 years (p = 0.39 and 0.45, respectively). Conclusions: Paternal SCH was associated with worse clinical outcomes after IVF/ICSI, whereas this detrimental impact was only present in males ≥35 years old. Prospective studies and basic research are warranted to confirm these results and to clarify the mechanisms underlying these associations, respectively.

Predictive value of the sperm DNA fragmentation index for low or failed IVF fertilization in men with mild-to-moderate asthenozoospermia.

INTRODUCTION: It has been observed that there is an increased incidence of total fertilization failure (TFF) and a low fertilization rate (LFR, <25 %) during conventional in vitro fertilization (IVF) treatments involving men with poor sperm motility. These men also exhibit a high sperm DNA fragmentation index (DFI), which has adverse effects on various IVF outcomes. However, the relationship between a high DFI and an increased TFF or LFR during IVF cycles has not been elucidated. Here, we aimed to investigate the association between the sperm DFI and TFF or LFR in IVF cycles involving men with mild-to-moderate asthenozoospermia and normozoospermia. MATERIALS AND METHODS: This retrospective study included 116 men diagnosed as mild-to-moderate asthenozoospermia, and 407 men with normozoospermia. The sperm DFI was assessed using the sperm chromatin dispersion (SCD) test. RESULTS: Men in the asthenozoospermia group had a significantly higher incidence of cycles with a TFF or LFR (9.5 % vs 2.7 %, P = 0.01), and these were associated significantly with an increased DFI (P < 0.01). After adjustment for confounding factors, a TFF or LFR was to correlate significantly with the DFI (odds ratio: 1.188; 95 % confidence interval, 1.035-1.363; P = 0.014). Area under the receiver operating characteristic curve was 0.772. No similar relationships between the DFI and IVF outcomes were observed in the normozoospermia group. CONCLUSIONS: For men with mild-to-moderate asthenozoospermia, a high sperm DFI is associated with a decreased fertilization rate and an increased risk of a TFF or LFR. Additional prospectively-designed studies are warranted to confirm our results.

Imprinting alterations in sperm may not significantly influence ART outcomes and imprinting patterns in the cord blood of offspring.

An increase in imprinting disorders in children conceived though assisted reproductive technologies (ARTs) has been the subject of several reports. The transmission of imprinting errors from the sperm of infertile fathers is believed to be a possible reason for the increased occurrence of these disorders. However, whether the imprinting alterations in sperm affect ART outcomes and the imprinting of offspring is unclear. In the current study, we analyzed the methylation of H19, SNRPN and KCNQ1OT1 by pyrosequencing sperm samples from 97 infertile patients and 31 proven fertile males as well as cord blood samples from 13 infantswho were conceived by infertile parents through intracytoplasmic sperm injection (ICSI) and 30 healthy newborns who were conceived naturally. After four cases were excluded owing to the lack of a sequencing signal, the infertile patients were subgrouped into normal (69 cases) and abnormal (24 cases) imprinting groups according to the reference range set by the control group. Between the groups, there were no significant differences in ART outcomes. Significantly different levels of methylation were detected in H19, but none of the imprinted genes were determined to be outside of the methylation reference range set by the values derived from the naturally conceived controls. Three CpG loci were found to be significantly hypomethylated in the maternally imprinted gene KCNQ1OT1 in two patients from the abnormal imprinting group, none of which were caused by sperm imprinting errors. In addition, the paternal H19 gene exhibited discrepant methylation patterns between the sperm controls and the cord blood controls. Our data suggest that increased imprinting errors in the sperm of infertile patients do not have an obvious influence on ART outcomes or the imprinting of offspring.

[Identification of proteins interacting with the circadian clock protein PER1 in tumors using bacterial two-hybrid system technique].

OBJECTIVE: To identify protein-protein interaction partners of PER1 (period circadian protein homolog 1), key component of the molecular oscillation system of the circadian rhythm in tumors using bacterial two-hybrid system technique. METHODS: Human cervical carcinoma cell Hela library was adopted. Recombinant bait plasmid pBT-PER1 and pTRG cDNA plasmid library were cotransformed into the two-hybrid system reporter strain cultured in a special selective medium. Target clones were screened. After isolating the positive clones, the target clones were sequenced and analyzed. RESULTS: Fourteen protein coding genes were identified, 4 of which were found to contain whole coding regions of genes, which included optic atrophy 3 protein (OPA3) associated with mitochondrial dynamics and homo sapiens cutA divalent cation tolerance homolog of E. coli (CUTA) associated with copper metabolism. There were also cellular events related proteins and proteins which are involved in biochemical reaction and signal transduction-related proteins. CONCLUSION: Identification of potential interacting proteins with PER1 in tumors may provide us new insights into the functions of the circadian clock protein PER1 during tumorigenesis.

PIWIL2 induces c-Myc expression by interacting with NME2 and regulates c-Myc-mediated tumor cell proliferation.

c-Myc serves as a crucial regulator in multiple cellular events. Cumulative evidences demonstrate that anomalous c-Myc overexpression correlates with proliferation, invasion and metastasis in various human tumors. However, the transcriptionally activating mechanisms responsible for c-Myc overexpression are complex and continue to be intangible. Here we showed that Piwi-Like RNA-Mediated Gene Silencing 2 (PIWIL2) can upregulate c-Myc via binding with NME/NM23 nucleoside diphosphate kinase 2 (NME2). PIWIL2 promotes c-Myc transcription by interacting with and facilitating NME2 to bind to G4-motif region within c-Myc promoter. Interestingly, in a c-Myc-mediated manner, PIWIL2 upregulates RhoA, which in turn induces filamentary F-actin. Deficiency of PIWIL2 results in obstacle for c-Myc expression, cell cycle progress and cell proliferation. Taken together, our present work demonstrates that PIWIL2 modulates tumor cell proliferation and F-actin filaments via promoting c-Myc expression.

Piwil2 suppresses p53 by inducing phosphorylation of signal transducer and activator of transcription 3 in tumor cells.

Piwi proteins have been implicated in germ cell proliferation, differentiation, germline stem cell maintenance and transposon control in germline from Drosophila to mammals. The Piwi-like2 (piwil2) gene is mainly expressed in testis or embryonic cells among normal tissues but widely expressed in tumors. However, it remains to be fully determined through which mechanism piwil2 is involved in tumorigenesis. Here we report that Human piwil2, or Hili represses the tumor suppressor P53 in human cancer cells. Immunoprecipitation analysis shows that Piwil2 can directly associate with Signal Transducer and Activator of Transcription 3 (STAT3) protein via its PAZ domain and form a Piwil2/STAT3/c-Src triple protein-protein complex. Furthermore, STAT3 is phosphorylated by c-Src and translocated to nucleus, then binds to P53 promoter and represses its transcription. The present study demonstrated that Piwil2 plays a role in anti-apoptosis in tumor cells possessing P53 as a positive regulator of STAT3 signaling pathway, providing novel sights into roles of Piwil2 in tumorigenesis.