DPPA5A suppresses the mutagenic TLS and MMEJ pathways by modulating the cryptic splicing of Rev1 and Polq in mouse embryonic stem cells.

Genetic alterations are often acquired during prolonged propagation of pluripotent stem cells (PSCs). This ruins the stem cell quality and hampers their full applications. Understanding how PSCs maintain genomic integrity would provide the clues to overcome the hurdle. It has been known that embryonic stem cells (ESCs) utilize high-fidelity pathways to ensure genomic stability, but the underlying mechanisms remain largely elusive. Here, we show that many DNA damage response and repair genes display differential alternative splicing in mouse ESCs compared to differentiated cells. Particularly, Rev1 and Polq, two key genes for mutagenic translesion DNA synthesis (TLS) and microhomology-mediated end joining (MMEJ) repair pathways, respectively, display a significantly higher rate of cryptic exon (CE) inclusion in ESCs. The frequent CE inclusion disrupts the normal protein expressions of REV1 and POLθ, thereby suppressing the mutagenic TLS and MMEJ. Further, we identify an ESC-specific RNA binding protein DPPA5A which stimulates the CE inclusion in Rev1 and Polq. Depletion of DPPA5A in mouse ESCs decreased the CE inclusion of Rev1 and Polq, induced the protein expression, and stimulated the TLS and MMEJ activity. Enforced expression of DPPA5A in NIH3T3 cells displayed reverse effects. Mechanistically, we found that DPPA5A directly regulated CE splicing of Rev1. DPPA5A associates with U2 small nuclear ribonucleoprotein of the spliceosome and binds to the GA-rich motif in the CE of Rev1 to promote CE inclusion. Thus, our study uncovers a mechanism to suppress mutagenic TLS and MMEJ pathways in ESCs.

Steatotic hepatocyte-derived extracellular vesicles promote ß-cell apoptosis and diabetes via microRNA-126a-3p.

Extracellular vesicles (EVs) have emerged as a unique mediator of interorgan communications, playing important roles in the pathophysiologic process of various diseases, including diabetes and other metabolic diseases. Here, we reported that the EVs released by steatotic hepatocytes exerted a detrimental effect on pancreatic ß cells, leading to ß-cell apoptosis and dysfunction. The effect was profoundly attributable to an up-regulation of miR-126a-3p in the steatotic hepatocyte-derived EVs. Accordingly, overexpression of miR-126a-3p promoted, whereas inhibition of miR-126a-3p prevented ß-cell apoptosis, through a mechanism related to its target gene, insulin receptor substrate-2. Moreover, inhibition of miR-126a-3p by its specific antagomir was able to partially reverse the loss of ß-cell mass and ameliorate hyperglycaemia in diabetic mice. Thus, the findings reveal a novel pathogenic role of steatotic hepatocyte-derived EVs, which mechanistically links nonalcoholic fatty liver disease to the development of diabetes.

Low-molecular-weight heparin in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection: A meta-analysis.

INTRODUCTION: This meta-analysis aimed to evaluate the efficacy and safety of low-molecular-weight heparin (LMWH) on pregnancy outcomes in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). MATERIAL AND METHODS: A systematic literature search of PubMed, EMBASE, the Cochrane Library, and China National Knowledge Infrastructure was performed to identify randomized controlled trials (RCTs) comparing LMWH with no treatment or placebo published from database inception until February 19, 2023. Primary outcomes were the clinical pregnancy rate and implantation rate, and secondary outcomes were the live birth rate, miscarriage rate, and the risk of bleeding events. The certainty of the evidence was rated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Meta-analysis was conducted using STATA 14.0. RESULTS: Five RCTs involving 1094 thrombophilic women receiving IVF/ICSI were finally included. Administration of LMWH was associated with statistically higher clinical pregnancy rate (4 RCTs, risk ratio [RR] 1.50, 95% confidence interval [CI] 1.23-1.82, p < 0.001, low certainty evidence), implantation rate (5 RCTs, RR 1.49, 95% CI 1.25-1.78, p < 0.001, very low certainty evidence), and live birth rate (2 RCTs, RR 2.15, 95% CI 1.60-2.89, p < 0.001, very low certainty evidence), but with statistically lower miscarriage rate (2 RCTs, RR 0.36, 95% CI 0.15-0.86, p = 0.021, very low certainty evidence). However, using LMWH was linked to a higher risk of bleeding events (2 RCTs, RR 2.36, 95% CI 1.49-3.74, p < 0.001, very low certainty evidence). CONCLUSIONS: Very low certainty evidence suggests that administration of LMWH may benefit pregnancy outcomes in thrombophilic women receiving IVF/ICSI treatment, although it may also increase the risk of bleeding events. However, before putting our findings into practice, healthcare professionals should conduct an in-depth evaluation of the available evidence and specific patient situations. Furthermore, due to the low methodological quality of the included studies, more high-quality studies are needed to validate our findings in the future.

Should blastocyst transfer be performed in patients with 1-3 embryos available on day 3?

RESEARCH QUESTION: In patients with 1-3 embryos available on day 3, does blastocyst transfer reduce the chances of a clinical pregnancy by cancelling transfer cycles compared with cleavage transfer? DESIGN: This retrospective observational study included 423 IVF cycles performed from 1 January 2019 to 31 December 2020 at the Center for Reproduction and Fertility of the Second Affiliated Hospital of Kunming Medical University. Cleavage transfer was performed in 267 cycles and blastocyst transfer was performed in 156 cycles. The primary outcome was the ongoing pregnancy rate, and the secondary outcomes were clinical pregnancy rate and embryo cessation rate. Univariate analysis was performed to compare outcomes. A logistic regression analysis was performed to explore the association between transfer stage and ongoing pregnancy rate. RESULTS: No differences were observed in the ongoing pregnancy rate (25.84% versus 26.92%; odds ratio [OR] 0.95; 95% confidence interval [CI] 0.61-1.50; P = 0.82) and embryo cessation rate (83.48% versus 85.75%; OR 1.19; 95% CI 0.82-1.75; P = 0.40) between the two groups. Logistic regression analysis showed no association between transfer stage and ongoing pregnancy rate (OR 1.06; 95% CI 0.64-1.73). CONCLUSIONS: Blastocyst transfer does not reduce the chances of a clinical pregnancy. These results support the proposal of blastocyst transfer in patients with 1-3 embryos available on day 3.

What is the impact of granulocyte colony-stimulating factor (G-CSF) in subcutaneous injection or intrauterine infusion and during both the fresh and frozen embryo transfer cycles on recurrent implantation failure: a systematic review and meta-analysis?

BACKGROUND: Among recurrent implantation failure (RIF) patients, the rate of successful implantation remains relatively low due to the complex etiology of the condition, including maternal, embryo and immune factors. Effective treatments are urgently needed to improve the outcomes of embryo transfer for RIF patients. In recent years, many researchers have focused on immunotherapy using granulocyte colony-stimulating factor (G-CSF) to regulate the immune environment. However, the study of the G-CSF for RIF patients has reached conflicting conclusions. The aim of this systematic review and meta-analysis was performed to further explore the effects of G-CSF according to embryo transfer cycle (fresh or frozen) and administration route (subcutaneous injection or intrauterine infusion) among RIF patients. METHOD: The PubMed, Embase and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for literature published from the initial to October 2020. The meta-analysis, random-effects model and heterogeneity of the studies with I2 index were analyzed. Stata 15 was used for statistical analysis. RESULTS: A total of 684 studies were obtained through the databases mentioned above. Nine RCTs included 976 RIF patients were enrolled in this meta-analysis. Subgroup analysis indicated that G-CSF improved the clinical pregnancy rate for both the fresh and frozen embryo transfer cycles (fresh RR: 1.74, 95% CI: 1.27-2.37, I2 = 0.0%, n = 410; frozen RR: 1.44, 95% CI: 1.14-1.81, I2 = 0.0.%, n = 366), and for both subcutaneous injection and intrauterine infusion (subcutaneous RR: 1.73, 95% CI: 1.33-2.23, I2 = 0.0%, n = 497; intrauterine RR: 1.39, 95% CI: 1.09-1.78, I2 = 0.0%, n = 479), but the biochemical pregnancy rate of the RIF group was also higher than that of the control group (RR: 1.85, 95% CI: 1.28-2.68; I2 = 20.1%, n = 469). There were no significant differences in the miscarriage rate (RR: 1.13, 95% CI: 0.25-5.21: I2 = 63.2%, n = 472) and live birth rate (RR: 1.43, 95% CI: 0.86-2.36; I2 = 52.5%; n = 372) when a random-effects model was employed. CONCLUSION: The administration of G-CSF via either subcutaneous injection or intrauterine infusion and during both the fresh and frozen embryo transfer cycles for RIF patients can improve the clinical pregnancy rate. However, whether G-CSF is effective in improving livebirth rates of RIF patients is still uncertain, continued research on the utilization and effectiveness of G-CSF is recommended before G-CSF can be considered mainstream treatment for RIF patients.

Hepatocyte-derived extracellular vesicles promote endothelial inflammation and atherogenesis via microRNA-1.

BACKGROUND & AIMS: Clinical evidence has indicated a close link between non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD). However, the underlying mechanism remains to be elucidated. This study aimed to explore a potential role of hepatocyte-derived extracellular vesicles (EVs) in endothelial inflammation and atherogenesis in the context of NAFLD. METHODS: EVs were isolated, quantified and characterized from steatotic hepatocytes. An endothelial cell-specific PCR array was used to screen the functional properties of EVs. Profiling of global microRNA expression was conducted in EVs. The expression level and biological function of microRNA-1 (miR-1) was determined by quantitative PCR, immunoblot and reporter gene assays, respectively. The in vivo effect of miR-1 on atherogenesis was investigated in apolipoprotein E (ApoE)-deficient mice administered with a miR-1-specific inhibitor, antagomiR-1. RESULTS: Steatotic hepatocytes released more EVs, which had significantly altered miRNA expression profiles compared to the EVs released by control hepatocytes. Endothelial cells co-cultured with steatotic hepatocytes, or treated with their EVs or miR-1, expressed significantly more proinflammatory molecules, as well as exhibiting increased NF-κB activity and reduced Kruppel-like factor 4 (KLF4) expression. EV-induced endothelial inflammation was prevented by either downregulation or inhibition of miR-1. While miR-1 treatment suppressed KLF4 expression and reporter gene activity, overexpression of KLF4 dramatically abolished the miR-1-induced endothelial inflammation. Moreover, not only did the miR-1 inhibitor reduce endothelial inflammation in vitro, but it also attenuated atherogenesis in ApoE-deficient mice. CONCLUSION: Steatotic hepatocyte-derived EVs promote endothelial inflammation and facilitate atherogenesis by miR-1 delivery, KLF4 suppression and NF-κB activation. The findings illustrate an important role of hepatocyte-derived EVs in distant communications between the liver and vasculature, suggesting a new mechanism underlying the link between NAFLD and CVD. LAY SUMMARY: Non-alcoholic fatty liver disease (NAFLD), a condition highly prevalent in obese and/or diabetic patients, is emerging as an independent risk factor of cardiovascular disease. Herein, we demonstrated that extracellular vesicles, released by hepatocytes under NAFLD conditions, cause vascular endothelial inflammation and promote atherosclerosis. Within these toxic vesicles, we identified a small molecular cargo that acted as a potent inducer of endothelial inflammation. By inhibiting this cargo's function, a specific gene-based inhibitor profoundly attenuated atherogenesis in mice, uncovering a novel mechanism which may be used to prevent or treat cardiovascular disease in patients with NAFLD.

Interleukin 6 in follicular fluid reduces embryo fragmentation and improves the clinical pregnancy rate.

PURPOSE: The aim of this study was to evaluate the role of interleukin 6 in embryo development in the in vitro fertilization cycles. METHODS: This was a retrospective cohort study. One hundred and three women undergoing in vitro fertilization and embryo transfer due to a tubal factor were included in the study. The follicular fluid IL-6 levels on oocyte retrieval day from each patient were determined by ELISA. The relationships between follicular fluid IL-6 levels and IVF cycle parameters were investigated. RESULTS: The levels of follicular fluid IL-6 were not affected by the use of drugs for superovulation or by estrogen. In addition, follicular fluid IL-6 levels did not affect the number of oocytes retrieved or the MII oocyte rate. High levels of follicular fluid IL-6 correlated with a significant increase in the rates of clinical pregnancy. Follicular fluid IL-6 levels did not affect the cell number or the blastomere symmetry of day 3 embryos, but it did significantly reduce the embryo fragmentation rate. CONCLUSIONS: High levels of follicular fluid IL-6 improved the rates of clinical pregnancy and reduce embryo fragmentation.

HC diet inhibited testosterone synthesis by activating endoplasmic reticulum stress in testicular Leydig cells.

Emerging epidemiological studies indicate that hypercholesterolaemia is a risk factor for testosterone deficiency. However, the underlying mechanism is unclear. Testicular Leydig cells are the primary source of testosterone in males. To identify the effect and mechanism of cholesterol overload on Leydig cell function, rats were fed with a HC (HC) diet to induce hypercholesterolaemia. During the 16-week feeding period, serum testosterone levels were reduced in a time-dependent manner in rats fed the HC diet. Accordingly, these steroidogenic enzymes within the Leydig cells, including steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage cytochrome P450 (P450scc) and 3ß-hydroxysteroid dehydrogenase (3ß-HSD), were down-regulated. Notably, the HC-fed rats showed evident endoplasmic reticulum (ER) stress in the testis, including a dilated ER as an evident pathological change in the Leydig cell ultrastructure, up-regulated ER stress biomarker (binding immunoglobulin protein) levels and activation of the activating transcription factor 6 (ATF6)-related unfolded protein response pathway. Further analysis showed that when 4-phenyl butyric acid (4-PBA) was used to block ER stress in HC-fed rats for 8 weeks, the testosterone deficiency was significantly alleviated. Our findings suggested that high dietary cholesterol intake affected serum testosterone levels by down-regulating steroidogenic enzymes and that activated ER stress might serve as the underlying mechanism.

Interleukin-6 Concentration in Single-Embryo Medium Is Associated with Blastocyst Formation.

IL-6 plays an important role in oogenesis in humans. However, at the preimplantation stage, IL-6 production and the role in embryo development remain unclear. In this study, IL-6 concentrations in single-embryo media were analyzed. In addition, the association between IL-6 production and blastocyst formation was investigated. Single-embryo culture media from 194 embryos were collected on day 6 after fertilization and divided into four groups according to the developmental stage of the corresponding embryo, as follows: cleavage stage group, morula-early blastocyst group, unavailable full blastocyst group, and available full blastocyst group. IL-6 concentrations were significantly lower in the cleavage stage group than in the morula-early blastocyst group (p = 0.009), in the unavailable full blastocyst group (p = 0.003), and in the available full blastocyst group (p < 0.001). Logistic regression analysis showed that IL-6 concentration in single-embryo medium was significantly associated with blastocyst formation (odds ratios ß1 = 1.876, 95% CI 1.433 to 2.644, p < 0.0001). Therefore, IL-6 was produced by human preimplantation embryos throughout the preimplantation stage and may play a role in embryo development.

Response Surface Optimization of Extraction Conditions for the Active Components with High Acetylcholinesterase Inhibitory Activity and Identification of Key Metabolites from Acer truncatum Seed Oil Residue.

The State Council of China has called for the comprehensive development and utilization of Acer truncatum resources. However, research on one of its by-products, namely seed oil residue (ASR), from seed oil extraction is seriously insufficient, resulting in a waste of these precious resources. We aimed to optimize the conditions of ultrasound-assisted extraction (UAE) using a response surface methodology to obtain high acetylcholinesterase (AChE) inhibitory components from ASR and to tentatively identify the active metabolites in ASR using non-targeted metabolomics. Based on the results of the independent variables test, the interaction effects of three key extracting variables, including methanol concentration, ultrasonic time, and material-to-liquid ratio, were further investigated using the Box-Behnken design (BBD) to obtain prior active components with high AChE inhibitory activity. UPLC-QTOF-MS combined with a multivariate method was used to analyze the metabolites in ASR and investigate the causes of activity differences. Based on the current study, the optimal conditions for UAE were as follows: methanol concentration of 85.06%, ultrasonic time of 39.1 min, and material-to-liquid ratio of 1.06:10 (g/mL). Under these optimal conditions, the obtained extracts show strong inhibitions against AChE with half maximal inhibitory concentration (IC50) values ranging from 0.375 to 0.459 µg/mL according to an Ellman's method evaluation. Furthermore, 55 metabolites were identified from the ASR extracted using methanol in different concentrations, and 9 biomarkers were subsequently identified as potential compounds responsible for the observed AChE inhibition. The active extracts have potential to be used for the development of functional foods with positive effects on Alzheimer's disease owing to their high AChE inhibition activity. Altogether, this study provides insights into promoting the comprehensive utilization of A. truncatum resources.

High cholesterol diet-induced testicular dysfunction in rats.

PURPOSE: Hypercholesterolemia due to a high-cholesterol diet is linked to numerous diseases and may lead to male infertility. However, the underlying mechanism remains unknown. The maintenance of male fertility requires intact testicular structures (including seminiferous tubules and mesenchyme) and functioning cells (Leydig cells, Sertoli cells and germ cells, etc.), production of appropriate concentrations of sex hormones, and cooperation among testicular cells. Thus, we considered whether male fertility declined as the structure and function of testicular cells were altered in rats on a high-cholesterol diet. METHODS: Male Sprague Dawley rats were fed either a standard or a high-cholesterol diet for 16 weeks. Serum sex hormones, lipid components, semen quality, and fertility rate were assayed in the rats. The 3ß-hydroxysteroid dehydrogenase (3ß-HSD), Wilms tumor 1 (WT-1), and deleted in azoospermia-like (DAZL) were regarded as specific markers of Leydig, Sertoli, and germ cells in rats. In addition, the ultrastructure of the testis and expression levels of particular marker molecules of testicular cells were further investigated. RESULTS: Compared to rats fed on a regular diet, the serum testosterone levels and sperm progressive motility decreased in rats fed high cholesterol. Moreover, we observed a deformed nucleus, dilated smooth endoplasmic reticulum, and swollen mitochondria of Leydig cells and a schizolytic nucleus of Sertoli cells in rats on a high-cholesterol diet. The 3ß-HSD, WT-1, and DAZL protein expression levels were significantly reduced in rats on a high-cholesterol diet. CONCLUSIONS: Our results showed that a high-cholesterol diet adversely affected testosterone production and sperm progressive motility, possibly due to Leydig, Sertoli, and germ cell abnormalities.

Single-Dose Versus Multiple-Dose GnRH Agonist for Luteal-Phase Support in Women Undergoing IVF/ICSI Cycles: A Network Meta-Analysis of Randomized Controlled Trials.

Background: Although gonadotropin-releasing hormone (GnRH) agonist has been introduced as a beneficial luteal phase support (LPS), the optimal strategy of GnRH agonist remains unclear. This network meta-analysis was therefore performed to determine the comparative efficacy and safety of multiple-dose versus single-dose GnRH agonist protocol for LPS in patients undergoing IVF/ICSI cycles. Methods: We searched relevant studies in PubMed, Embase and the Cochrane Registry of Controlled Trials (CENTRAL) from their inception util to September 2021. Live birth, clinical pregnancy rate, multiple pregnancy rate, and clinical abortion rate was evaluated. Pairwise and network meta-analysis were conducted using RevMan and ADDIS based on random-effects model, respectively. Moreover, the prioritization of protocols based on ranking probabilities for different outcomes were performed. Results: Sixteen RCTs met our eligibility criteria. Pairwise meta-analysis showed that multiple-dose protocol of GnRH agonist was effective for increasing live birth rate (OR 1.80, 95% CI 1.15 to 2.83, p=0.01) and clinical pregnancy rate (OR 1.89, 95% CI 1.01 to 3.56, p=0.05) as well as decreasing clinical abortion rate (OR 0.55, 95% CI 0.34 to 0.90, p=0.02). Meanwhile, single-dose protocol of GnRH agonist was effective for increasing clinical pregnancy rate (OR 1.45, 95% CI 1.11 to 1.89, p=0.007) and multiple pregnancy rate (OR 2.55, 95% CI 1.12 to 5.78, p=0.03). However, network meta-analysis only confirmed that multiple-dose protocol of GnRH agonist was the best efficacious strategy for live birth rate (OR 2.04, 95% CrI 1.19 to 3.93) and clinical pregnancy rate (OR 2.10, 95% CrI 1.26 to 3.54). Conclusion: Based on the results of NMA, multiple-dose protocol may be the optimal strategy for patients undergoing IVF/ICSI cycles owing to its advantage in increasing live birth and clinical pregnancy rate. Moreover, single-dose protocol may be the optimal strategy for improving multiple pregnancy rate. However, with the limitations, more RCTs are required to confirm our findings.

Acute Treatment with a Novel TRPC4/C5 Channel Inhibitor Produces Antidepressant and Anxiolytic-Like Effects in Mice.

Transient receptor potential canonical (TRPC) channels are widely expressed in brain and involved in various aspects of brain function. Both TRPC4 and TRPC5 have been implicated in innate fear function, which represents a key response to environmental stress. However, to what extent the TRPC4/C5 channels are involved in psychiatric disorders remains unexplored. Here, we tested the antidepressant and anxiolytic-like effects of a newly identified TRPC4/C5 inhibitor, M084. We show that a single intraperitoneal administration of M084 at 10 mg/kg body weight to C57BL/6 male mice significantly shortened the immobility time in forced swim test and tail suspension test within as short as 2 hours. The M084-treated mice spent more time exploring in illuminated and open areas in light/dark transition test and elevated plus maze test. In mice subjected to chronic unpredictable stress, M084 treatment reversed the enhanced immobility time in forced swim test and decreased the latency to feed in novelty suppressed feeding test. The treatment of M084 increased BDNF expression in both mRNA and protein levels, as well as phosphorylation levels of AKT and ERK, in prefrontal cortex. Our results indicate that M084 exerts rapid antidepressant and anxiolytic-like effects at least in part by acting on BDNF and its downstream signaling. We propose M084 as a lead compound for further druggability research.