TXNIP knockdown ameliorates hepatic ischemia/reperfusion injury by inhibiting apoptosis and improving mitochondrial dysfunction via HIF-1α.

This study aims to investigate whether thioredoxin-interacting protein (TXNIP) regulates cell viability, cell apoptosis and mitochondrial damage in OGD/R-induced hepatocytes and to explore its underlying mechanism. AML12 cells were cultured under oxygen-glucose deprivation/reperfusion (OGD/R) conditions. TXNIP mRNA was detected using qRT-PCR, and the TXNIP protein was analyzed using western blotting. TXNIP-targeted short hairpin RNA (sh-TXNIP) lentivirus was used to infect the AML12 cells. CCK8 and TUNEL assays were applied to detect cell viability and apoptosis, respectively. DCFH-DA probe was used to determine reactive oxygen species (ROS) release level, and JC-1 probe was used to evaluate mitochondrial membrane potential (MMP). The localization of TXNIP and HIF-1α was observed using immunofluorescence. Our results showed that TXNIP markedly increased in AML12 cells treated with OGD/R. TXNIP knockdown increased cell viability and reduced cell apoptosis under OGD/R treatment. Moreover, MMP significantly increased and ROS release decreased in cells after TXNIP knockdown under OGD/R treatment. Additionally, TXNIP knockdown markedly increased the expression of HIF-1α. HIF-1α exhibited nuclear translocation following OGD/R induction, and TXNIP knockdown further promoted it. Compared with the OGD/R + sh-TXNIP group, HIF-1α agonist ML228 inhibited cell apoptosis and ROS release, and increased MMP. However, HIF-1α inhibitor PX478 had the opposite effect. In summary, TXNIP deletion ameliorated AML12 cell injury caused by OGD/R via promoting HIF-1α expression and nuclear translocation, manifested by inhibiting cell apoptosis and alleviating mitochondrial dysfunction.

The mRNA-destabilizing protein Tristetraprolin targets "meiosis arrester" Nppc mRNA in mammalian preovulatory follicles.

C-natriuretic peptide (CNP) and its receptor guanylyl cyclase, natriuretic peptide receptor 2 (NPR2), are key regulators of cyclic guanosine monophosphate (cGMP) homeostasis. The CNP-NPR2-cGMP signaling cascade plays an important role in the progression of oocyte meiosis, which is essential for fertility in female mammals. In preovulatory ovarian follicles, the luteinizing hormone (LH)-induced decrease in CNP and its encoding messenger RNA (mRNA) natriuretic peptide precursor C (Nppc) are a prerequisite for oocyte meiotic resumption. However, it has never been determined how LH decreases CNP/Nppc In the present study, we identified that tristetraprolin (TTP), also known as zinc finger protein 36 (ZFP36), a ubiquitously expressed mRNA-destabilizing protein, is the critical mechanism that underlies the LH-induced decrease in Nppc mRNA. Zfp36 mRNA was transiently up-regulated in mural granulosa cells (MGCs) in response to the LH surge. Loss- and gain-of-function analyses indicated that TTP is required for Nppc mRNA degradation in preovulatory MGCs by targeting the rare noncanonical AU-rich element harbored in the Nppc 3' UTR. Moreover, MGC-specific knockout of Zfp36, as well as lentivirus-mediated knockdown in vivo, impaired the LH/hCG-induced Nppc mRNA decline and oocyte meiotic resumption. Furthermore, we found that LH/hCG activates Zfp36/TTP expression through the EGFR-ERK1/2-dependent pathway. Our findings reveal a functional role of TTP-induced mRNA degradation, a global posttranscriptional regulation mechanism, in orchestrating the progression of oocyte meiosis. We also provided a mechanism for understanding CNP-dependent cGMP homeostasis in diverse cellular processes.

Mitochondrial transfer from induced pluripotent stem cells rescues developmental potential of in vitro fertilized embryos from aging females†.

Conventional heterologous mitochondrial replacement therapy is clinically complicated by "tri-parental" ethical concerns and limited source of healthy donor oocytes or zygotes. Autologous mitochondrial transfer is a promising alternative in rescuing poor oocyte quality and impaired embryo developmental potential associated with mitochondrial disorders, including aging. However, the efficacy and safety of mitochondrial transfer from somatic cells remains largely controversial, and unsatisfying outcomes may be due to distinct mitochondrial state in somatic cells from that in oocytes. Here, we propose a potential strategy for improving in vitro fertilization (IVF) outcomes of aging female patients via mitochondrial transfer from induced pluripotent stem (iPS) cells. Using naturally aging mice and well-established cell lines as models, we found iPS cells and oocytes share similar mitochondrial morphology and functions, whereas the mitochondrial state in differentiated somatic cells is substantially different. By microinjection of isolated mitochondria into fertilized oocytes following IVF, our results indicate that mitochondrial transfer from iPS, but not MEF cells, can rescue the impaired developmental potential of embryos from aging female mice and obtain an enhanced implantation rate following embryo transfer. The beneficial effect may be explained by the fact that mitochondrial transfer from iPS cells not only compensates for aging-associated loss of mtDNA, but also rescues mitochondrial metabolism of subsequent preimplantation embryos. Using mitochondria from iPS cells as the donor, our study not only proposes a promising strategy for improving IVF outcomes of aging females, but also highlights the importance of synchronous mitochondrial state in supporting embryo developmental potential.

MicroRNA-449b-5p targets HMGB1 to attenuate hepatocyte injury in liver ischemia and reperfusion.

MicroRNAs (miRNAs) participate in the pathological process of liver ischemia/reperfusion (I/R) injury. MiR-449b-5p is the target miRNA of high mobility group box 1 (HMGB1). Its role and molecular mechanism in liver I/R injury remain unidentified. In this study, we found a protective effect of miR-449b-5p against hepatic I/R injury. HMGB1 expression significantly increased, whereas miR-449b-5p dramatically decreased in patients after liver transplant and in L02 cells exposed to hypoxia/reoxygenation (H/R). A dual-luciferase reporter assay confirmed the direct interaction between miR-449b-5p and the 3' untranslated region of HMGB1 messenger RNA. We also found that overexpression of miR-449b-5p significantly promoted cell viability and inhibited cell apoptosis of L02 cells exposed to H/R. Moreover, miR-449b-5p repressed HMGB1 protein expression and nuclear factor-κB (NF-κB) pathway activation in these L02 cells. In an in vivo rat model of hepatic I/R injury, overexpression of miR-449b-5p significantly decreased alanine aminotransferase and aspartate aminotransferase and inhibited the HMGB1/NF-κB pathway. Our study thus suggests that miR-449b-5p alleviated hepatic I/R injury by targeting HMGB1 and deactivating the NF-κB pathway, which may provide a novel and promising therapeutic target for hepatic I/R injury.

Melatonin protects in vitro matured porcine oocytes from toxicity of Aflatoxin B1.

Aflatoxin B1 (AFB1) is a major food and feed contaminant that threaten public health. Previous studies indicate that AFB1 exposure disrupted oocyte maturation. However, an effective and feasible method is unavailable for protecting oocytes against toxicity of AFB1. In the present study, using in vitro matured porcine oocytes and parthenogenetic embryos as model, we confirmed that AFB1 exposure during in vitro oocyte maturation (IVM) significantly impaired both nuclear and cytoplasmic maturation in a dose- and time-dependent manner. The different concentrations of melatonin were also tested for their protective effects on oocytes against the AFB1-induced toxicity. Our results showed that supplementation of a relative high concentration of melatonin (10-3 mol/L) during IVM efficiently reversed the impaired development rate and blastocyst quality, to the levels comparable to those of the control group. Further analysis indicated that melatonin application efficiently alleviated reactive oxygen species accumulation and initiation of apoptosis induced by AFB1 exposure. In addition, disrupted GSH/GPX system, as well as inhibited mitochondrial DNA (mtDNA) replication and mitochondrial biogenesis in AFB1-treated oocytes, can be notably reversed by melatonin application. Furthermore, cumulus cells may be important in mediating the toxicity of AFB1 to oocytes, and the metabolism of AFB1 in cumulus cells can be depressed by melatonin. To the best of our knowledge, this is the first report to confirm that melatonin application can efficiently protect oocytes from AFB1-induced toxicity. Our study provides a promising and practical strategy for alleviating or reversing AFB1-induced female reproductive toxicity in both clinical treatment and domestic reproductive management.

Impaired imprinted X chromosome inactivation is responsible for the skewed sex ratio following in vitro fertilization.

Dynamic epigenetic reprogramming occurs during normal embryonic development at the preimplantation stage. Erroneous epigenetic modifications due to environmental perturbations such as manipulation and culture of embryos during in vitro fertilization (IVF) are linked to various short- or long-term consequences. Among these, the skewed sex ratio, an indicator of reproductive hazards, was reported in bovine and porcine embryos and even human IVF newborns. However, since the first case of sex skewing reported in 1991, the underlying mechanisms remain unclear. We reported herein that sex ratio is skewed in mouse IVF offspring, and this was a result of female-biased peri-implantation developmental defects that were originated from impaired imprinted X chromosome inactivation (iXCI) through reduced ring finger protein 12 (Rnf12)/X-inactive specific transcript (Xist) expression. Compensation of impaired iXCI by overexpression of Rnf12 to up-regulate Xist significantly rescued female-biased developmental defects and corrected sex ratio in IVF offspring. Moreover, supplementation of an epigenetic modulator retinoic acid in embryo culture medium up-regulated Rnf12/Xist expression, improved iXCI, and successfully redeemed the skewed sex ratio to nearly 50% in mouse IVF offspring. Thus, our data show that iXCI is one of the major epigenetic barriers for the developmental competence of female embryos during preimplantation stage, and targeting erroneous epigenetic modifications may provide a potential approach for preventing IVF-associated complications.

TXNIP knockdown alleviates hepatocyte ischemia reperfusion injury through preventing p38/JNK pathway activation.

Hepatic ischemia and reperfusion (I/R) injury is a major cause of liver damage during liver transplantation, resection surgery, shock, and trauma. It has been reported that TXNIP expression was upregulated in a rat model of hepatic I/R injury. However, the role of TXNIP in the hepatic I/R injury is little known. In our study, we investigated the biological role of TXNIP and its potential molecular mechanism in the human hepatic cell line (HL7702 cells). Using oxygen-glucose deprivation and reoxygenation (OGD/R) to create a cell model of hepatic I/R injury, we found that the mRNA and protein expression levels of TXNIP were upregulated in HL7702 cells exposed to OGD/R. TXNIP overexpression remarkably promoted OGD/R-induced cell apoptosis and lactate dehydrogenase (LDH) release, both of which were significantly decreased by TXNIP knockdown. The production of malondialdehyde (MDA) was also increased by TXNIP overexpression, but was reduced by TXNIP knockdown. Moreover, TXNIP overexpression significantly upregulated the phosphorylation of p38 and JNK, which was remarkably inhibited by TXNIP knockdown. Additionally, p38-specific inhibitor SB203580 abrogated the effect of TXNIP overexpression on OGD/R-induced cell injury. Taken together, these results indicated that TXNIP knockdown alleviated hepatocyte I/R injury through preventing p38/JNK pathway activation. Thus, TXNIP might offer a novel potential therapeutic target for the treatment of hepatic I/R injury.

Chlorogenic acid against palmitic acid in endoplasmic reticulum stress-mediated apoptosis resulting in protective effect of primary rat hepatocytes.

BACKGROUND: We demonstrated growing evidence supports a protective role of chlorogenic acid of rat hepatocytes elicited by two compounds, i.e. thapsigargin and palmitic acid. Nevertheless, little is known about the mechanisms of palmitic acid induced endoplasmic reticulum (ER) stress and cell death. METHODS: The proliferation of primary rat hepatocytes was detected by MTT assay. The expression of GRP78, CHOP and GRP94 was detected by Western blot analyses. Caspase-3 activity was detected by a Caspase-3 substrate kit. Cell apoptosis was detected by Hoechst 33342 staining. RESULTS: We demonstrated that incubation of hepatocytes for 16 h with palmitic acid elevated cell death. Moreover, Western blot analyses demonstrated increased levels of the endoplasmic reticulum stress markers - glucose regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), and glucose regulated protein 94 (GRP94). Chlorogenic acid could inhibit ER stress induced cell death and levels of indicators of ER stress caused by palmitic acid. The effect of thapsigargin, which evokes ER stress were reversed by chlorogenic acid. CONCLUSIONS: Altogether, our data indicate that in primary rat hepatocytes, chlorogenic acid prevents ER stress-mediated apoptosis of palmitic acid.

Efficient biallelic mutation in porcine parthenotes using a CRISPR-Cas9 system.

The parthenotes represent ideal models mimicking the embryonic development and characterizing the function of maternal genomes as well as an alternative source of pluripotent cell lines. Besides, parthenogenetically activated (PA) embryos serve as a rapid assay system to maximize the efficiency of generating genetically modified pig CRISPR/Cas9 system, an efficient and multiplex gene editing tool, has been utilized to modify the genome of porcine parthenotes. However, lower biallelic mutation rate and high mosaicism frequency were observed. Here, we aimed to enhance the biallelic mutation rate with reduced mosaicism by optimization of the concentration and injection time of the Cas9/sgRNA mixture in porcine parthenotes. The results showed that the efficient biallelic mutation (93%) and low mosaicism (33%) could be achieved in porcine parthenotes by cytoplasmic injection of Cas9 mRNA/sgRNA (125/12.5 ng/µl) after 8 h of parthenogenetical activation. Thus, our study provides an effective strategy for increasing the biallelic mutation rate and population homogeneity of genetically modified parthenotes, which will strengthen the role of parthenotes in uncovering early embryonic development and assessing the mutation efficiency due to the simplicity and adaptability of CRISPR/Cas9.

Downregulation of miR-199a-5p Disrupts the Developmental Potential of In Vitro-Fertilized Mouse Blastocysts.

Although in vitro fertilization (IVF), one of the most effective and successful assisted reproductive technologies, is widely used for treating infertility and in animal breeding, increasing evidence indicates that IVF offspring are linked to various short- or long-term consequences. Erroneous epigenetic modifications induced by IVF are suspected of contributing to these consequences. Among these epigenetic modifications, microRNAs may affect embryo implantation and early postimplantation development. Here, we performed comparative microRNA profiling between in vivo-fertilized (IVO group) and in vitro-fertilized (IVF group) mouse embryos at Embryonic Day 3.5 (E3.5) and E7.5. Our dynamic analyses showed that the dysregulated microRNAs were mainly associated with the regulation of genes involved in carcinogenesis, genetic information processing, glucose metabolism, cytoskeleton organization, and neurogenesis. Further analysis showed that miR-199a-5p was consistently downregulated in IVF embryos compared with their IVO counterparts. Through gain- and loss-of-function experiments, we demonstrated that IVF-induced downregulation of miR-199a-5p results in a higher glycolytic rate and lower developmental potential of IVF blastocysts, including cell lineage misallocation and lower fetal survival post implantation. Therefore, preventing downregulation of miR-199a-5p may become an effective strategy for improving the development of IVF peri-implantation embryos in the future.

Dynamic integrated analysis of DNA methylation and gene expression profiles in in vivo and in vitro fertilized mouse post-implantation extraembryonic and placental tissues.

STUDY HYPOTHESIS: How does in vitro fertilization (IVF) alter promoter DNA methylation patterns and its subsequent effects on gene expression profiles during placentation in mice? STUDY FINDING: IVF-induced alterations in promoter DNA methylation might have functional consequences in a number of biological processes and functions during IVF placentation, including actin cytoskeleton organization, hematopoiesis, vasculogenesis, energy metabolism and nutrient transport. WHAT IS KNOWN ALREADY: During post-implantation embryonic development, both embryonic and extraembryonic tissues undergo de novo DNA methylation, thereby establishing a global DNA methylation pattern, and influencing gene expression profiles. Embryonic and placental tissues of IVF conceptuses can have aberrant morphology and functions, resulting in adverse pregnancy outcomes such as pregnancy loss, low birthweight, and long-term health effects. To date, the IVF-induced global profiling of DNA methylation alterations, and their functional consequences on aberrant gene expression profiles in IVF placentas have not been systematically studied. STUDY DESIGN, SAMPLES/MATERIALS, METHODS: Institute for Cancer Research mice (6 week-old females and 8-9 week-old males) were used to generate in vivo fertilization (IVO) and IVF blastocysts. After either IVO and development (IVO group as control) or in vitro fertilization and culture (IVF group), blastocysts were collected and transferred to pseudo-pregnant recipient mice. Extraembryonic (ectoplacental cone and extraembryonic ectoderm) and placental tissues from both groups were sampled at embryonic day (E) 7.5 (IVO, n = 822; IVF, n = 795) and E10.5 (IVO, n = 324; IVF, n = 278), respectively. The collected extraembryonic (E7.5) and placental tissues (E10.5) were then used for high-throughput RNA sequencing (RNA-seq) and methylated DNA immunoprecipitation sequencing (MeDIP-seq). The main dysfunctions indicated by bioinformatic analyses were further validated using molecular detection, and morphometric and phenotypic analyses. MAIN RESULTS AND THE ROLE OF CHANCE: Dynamic functional profiling of high-throughput data, together with molecular detection, and morphometric and phenotypic analyses, showed that differentially expressed genes dysregulated by DNA methylation were functionally involved in: (i) actin cytoskeleton disorganization in IVF extraembryonic tissues, which may impair allantois or chorion formation, and chorioallantoic fusion; (ii) disturbed hematopoiesis and vasculogenesis, which may lead to abnormal placenta labyrinth formation and thereby impairing nutrition transport in IVF placentas; (iii) dysregulated energy and amino acid metabolism, which may cause placental dysfunctions, leading to delayed embryonic development or even lethality; (iv) disrupted genetic information processing, which can further influence gene transcriptional and translational processes. LIMITATIONS, REASONS FOR CAUTION: Findings in mouse placental tissues may not be fully representative of human placentas. Further studies are necessary to confirm these findings and determine their clinical significance. WIDER IMPLICATIONS OF THE FINDINGS: Our study is the first to provide the genome-wide analysis of gene expression dysregulation caused by DNA methylation during IVF placentation. Systematic understanding of the molecular mechanisms implicated in IVF placentation can be useful for the improvement of existing assisted conception systems to prevent these IVF-associated safety concerns. STUDY FUNDING AND COMPETING INTERESTS: This work was supported by grants from the National Natural Science Foundation of China (No. 31472092), and the National High-Tech R&D Program (Nos. 2011|AA100303, 2013AA102506). There was no conflict of interest.

IVF affects embryonic development in a sex-biased manner in mice.

Increasing evidence indicates that IVF (IVF includes in vitro fertilization and culture) embryos and babies are associated with a series of health complications, and some of them show sex-dimorphic patterns. Therefore, we hypothesized that IVF procedures have sex-biased or even sex-specific effects on embryonic and fetal development. Here, we demonstrate that IVF-induced side effects show significant sexual dimorphic patterns from the pre-implantation to the prenatal stage. During the pre-implantation stage, female IVF embryos appear to be more vulnerable to IVF-induced effects, including an increased percentage of apoptosis (7.22 ± 1.94 vs 0.71 ± 0.76, P<0.01), and dysregulated expression of representative sex-dimorphic genes (Xist, Hprt, Pgk1 and Hsp70). During the mid-gestation stage, IVF males had a higher survival rate than IVF females at E13.5 (male:female=1.33:1), accompanied with a female-biased pregnancy loss. In addition, while both IVF males and females had reduced placental vasculogenesis/angiogenesis, the compensatory placental overgrowth was more evident in IVF males. During the late-gestation period, IVF fetuses had a higher sex ratio (male:female=1.48:1) at E19.5, and both male and female IVF placentas showed overgrowth. After birth, IVF males grew faster than their in vivo (IVO) counterparts, while IVF females showed a similar growth pattern with IVO females. The present study provides a new insight into understanding IVF-induced health complications during embryonic and fetal development. By understanding and minimizing these sex-biased effects of the IVF process, the health of IVF-conceived babies may be improved in the future.

Tea polyphenols may attenuate the neurocognitive impairment caused by global cerebral ischemia/reperfusion injury via anti-apoptosis.

BACKGROUND/AIMS: Global cerebral ischemia/reperfusion (GCIR) may incur neurocognitive impairment. Tea polyphenols (TP) have strong anti-oxidant capacity. This study planned to investigate the protective effect of TP against the neurocognitive impairment caused by GCIR and its mechanism. METHODS: One-stage anterior approach for cerebral four-vessel occlusion (4VO) was used to construct the GCIR model. Sprague Dawley rats were randomly classified into Sham group, GCIR group, and TP group (n = 50 per group). Besides receiving the same 4VO, the rats in TP group were treated with TP (6.4%) injection from the tail vein 30 minutes before cerebral ischemia. Morris water-maze test was used to evaluate the changes in space recognition and memory and open field activity test to assess the activity and motor function of rats. The cell apoptotic study in hippocampal CA1 region at specified time points (12, 24, 48, and 72 hours after surgery) was carried out by the flow cytometry, histology (hematoxylin and eosin staining), and immunohistochemical (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining) examinations. One-way analysis of variance and least significant difference t-test were used and statistical significance considered at P < 0.05. RESULTS: Compared with the GCIR group, the TP group was significantly attenuated in the impairment of space recognition and memory caused by GCIR and so was the neuronal apoptosis in the hippocampal CA1 region (P < 0.05). CONCLUSION: TP may attenuate the impairment of space recognition and memory caused by GCIR via anti-apoptosis.

Dynamic comparisons of high-resolution expression profiles highlighting mitochondria-related genes between in vivo and in vitro fertilized early mouse embryos.

STUDY QUESTION: Does in vitro fertilization (IVF) induce comprehensive and consistent changes in gene expression associated with mitochondrial biogenesis and function in mouse embryos from the pre- to post-implantation stage? SUMMARY ANSWER: IVF-induced consistent mitochondrial dysfunction in early mouse embryos by altering the expression of a number of mitochondria-related genes. WHAT IS KNOWN ALREADY: Although IVF is generally safe and successful for the treatment of human infertility, there is increasing evidence that those conceived by IVF suffer increased health risks. The mitochondrion is a multifunctional organelle that plays a crucial role in early development. We hypothesized that mitochondrial dysfunction is associated with increased IVF-induced embryonic defects and risks in offspring. STUDY DESIGN, SIZE, DURATION: After either IVF and development (IVO groups as control) or IVF and culture (IVF groups), blastocysts were collected and transferred to pseudo-pregnant recipient mice. Both IVO and IVF embryos were sampled at E3.5, E7.5 and E10.5, and the expression profiles of mitochondria-related genes from the pre- to post-implantation stage were compared. PARTICIPANTS/MATERIALS, SETTING, METHODS: ICR mice (5- to 6-week-old males and 8- to 9-week-old females) were used to generate IVO and IVF blastocysts. Embryo day (E) 3.5 blastocysts were transferred to pseudo-pregnant recipient mice. Both IVO and IVF embryos were sampled at E3.5, E7.5 and E10.5 for generating transcriptome data. Mitochondria-related genes were filtered for dynamic functional profiling. Mitochondrial dysfunctions indicated by bioinformatic analysis were further validated using cytological and molecular detection, morphometric and phenotypic analysis and integrated analysis with other high-throughput data. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 806, 795 and 753 mitochondria-related genes were significantly (P < 0.05) dysregulated in IVF embryos at E3.5, E7.5 and E10.5, respectively. Dynamic functional profiling, together with cytological and molecular investigations, indicated that IVF-induced mitochondrial dysfunctions mainly included: (i) inhibited mitochondrial biogenesis and impaired maintenance of DNA methylation of mitochondria-related genes during the post-implantation stage; (ii) dysregulated glutathione/glutathione peroxidase (GSH/Gpx) system and increased mitochondria-mediated apoptosis; (iii) disturbed mitochondrial ß-oxidation, oxidative phosphorylation and amino acid metabolism; and (iv) disrupted mitochondrial transmembrane transport and membrane organization. We also demonstrated that some mitochondrial dysfunctions in IVF embryos, including impaired mitochondrial biogenesis, dysregulated GSH homeostasis and reactive oxygen species-induced apoptosis, can be rescued by treatment with melatonin, a mitochondria-targeted antioxidant, during in vitro culture. LIMITATIONS, REASONS FOR CAUTION: Findings in mouse embryos and fetuses may not be fully transferable to humans. Further studies are needed to confirm these findings and to determine their clinical significance better. WIDER IMPLICATIONS OF THE FINDINGS: The present study provides a new insight in understanding the mechanism of IVF-induced aberrations during embryonic development and the increased health risks in the offspring. In addition, we highlighted the possibility of improving existing IVF systems by modulating mitochondrial functions.

Effect of Desflurane versus Sevoflurane in Pediatric Anesthesia: A Meta-Analysis.

PURPOSE: To compare the effect of desflurane versus sevoflurane in pediatric anesthesia by conducting meta-analysis. METHODS: Studies were searched from PubMed, Medline, Springer, Elsevier Science Direct, Cochrane Library and Google Scholar up to July 2014. Weighted mean difference (WMD) or risk ratio (RR) and 95% confidence intervals (CIs) were considered as effect sizes. Heterogeneity across studies was assessed by Cochran Q test and I2 statistic. The random effects model was performed in the meta-analysis when heterogeneity was observed, or the fixed effect model was used. Review Manager 5.1 software was applied for the meta-analysis. RESULTS: A total of 11 studies (13 comparisons) involving 1,273 objects were included in this meta-analysis. No heterogeneity was observed between studies for any comparison but for postoperative extubation time. The results showed significant differences between desflurane and sevoflurane groups for postoperative extubation time (WMD = -3.87, 95%CI = -6.14 to -1.60, P < 0.01), eye opening time (WMD = -1.11, 95%CI = -1.49 to -0.72, P < 0.01), awakening time (WMD = -4.27, 95%CI = -5.28 to -3.26, P < 0.01) and agitation (RR = 1.44, 95%CI = 1.05 to 1.96, P = 0.02). No significant differences (P > 0.05) were detected for discharge from the recovery room, oculocardiac reflex, nausea and vomiting and severe pain. CONCLUSIONS: Desflurane may have less adverse effects than sevoflurane when used in pediatric anesthesia with significantly shorter postoperative extubation time, eye opening time and awakening time as well as slighter agitation.

Matrine inhibits the invasive properties of human osteosarcoma cells by downregulating the ERK-NF-κB pathway.

Matrine has been used in anti-inflammatory and anticancer therapies for a long time. However, the antimetastatic effect and molecular mechanism(s) of matrine on osteosarcoma are still unclear. Therefore, the aim of this study was to assess the effects of matrine and related mechanism(s) on osteosarcoma cells. In the study, we found that matrine inhibited the proliferation of osteosarcoma cells in vivo and in vitro and inhibited tumor cell metastasis in vitro at cytotoxic doses. Matrine also decreased the expression of the matrix metalloproteinases-2 and 9, decreased p50 and p65 nuclear translocation, and decreased the phosphorylated level of I-κ-B (IκB)-ß. In addition, matrine reduced the phosphorylated levels of extracellular signal-regulated kinase 1/2 proteins, which regulate the invasion of poorly differentiated cancer cells. Finally, when U2OS cells were grown as xenografts in nude mice, intragastric administration of matrine induced a significant dose-dependent decrease in tumor growth. These results show the anticancer properties of matrine, which include the inhibition of invasion and proliferation of human osteosarcoma cells.

METTL3 Modulates TXNIP Expression to Affect the Activation of NLRP3 Inflammasome in Hepatic Cells Under Oxygen-Glucose Deprivation/Reperfusion Injury.

Hepatic ischemia-reperfusion (I/R) injury is still a major risk factor and unsolved problem in hepatic surgery. Methyltransferase-like 3 (METTL3), an important m6A-modified methylase, regulates inflammation and cellular stress response. In this study, we demonstrated the special role of METTL3 and its underlying mechanism in hepatic I/R injury. In the mouse model of hepatic I/R and in the oxygen-glucose deprivation and reoxygenation (OGD/R)-induced AML12 and NCTC 1469 cells, the expression of METTL3 was significantly upregulated. Inhibition of METTL3 in OGD/R-induced AML12 and NCTC 1469 cells both increased the cell viability, declined the cell apoptosis, and decreased the reactive oxygen species (ROS) and the release levels of interleukin-1ß (IL-1ß) and interleukin-18 (IL-18), diminishing NLRP3 and Caspase1-p20 expressions. Moreover, METTL3 positively modulated TXNIP expression in an m6A manner. TXNIP overexpression reversed the effects of METTL3 knockdown on OGD/R-induced injury in AML12 cells. Furthermore, inhibition of NLRP3 inflammasome activity contributed to the protective effects of TXNIP knockdown in OGD/R-induced AML12 cells. In conclusion, METTL3 knockdown alleviated OGD/R-induced hepatocyte injury, and the specific mechanism was associated with the inhibition of NLRP3 inflammasome activation, which was attributed to the reduction of TXNIP in an m6A-dependent manner.

Single-embryo transcriptomic atlas of oxygen response reveals the critical role of HIF-1α in prompting embryonic zygotic genome activation.

Adaptive response to physiological oxygen levels (physO2; 5% O2) enables embryonic survival in a low-oxygen developmental environment. However, the mechanism underlying the role of physO2 in supporting preimplantation development, remains elusive. Here, we systematically studied oxygen responses of hallmark events in preimplantation development. Focusing on impeded transcriptional upregulation under atmospheric oxygen levels (atmosO2; 20% O2) during the 2-cell stage, we functionally identified a novel role of HIF-1α in promoting major zygotic genome activation by serving as an oxygen-sensitive transcription factor. Moreover, during blastocyst formation, atmosO2 impeded H3K4me3 and H3K27me3 deposition by deregulating histone-lysine methyltransferases, thus impairing X-chromosome inactivation in blastocysts. In addition, we found atmosO2 impedes metabolic shift to glycolysis before blastocyst formation, thus resulting a low-level histone lactylation deposition. Notably, we also reported an increased sex-dimorphic oxygen response of embryos upon preimplantation development. Together, focusing on genetic and epigenetic events that are essential for embryonic survival and development, the present study advances current knowledge of embryonic adaptive responses to physO2, and provides novel insight into mechanism underlying irreversibly impaired developmental potential due to a short-term atmosO2 exposure.

STING Agonist cGAMP Attenuates Sleep Deprivation-Induced Neuroinflammation and Cognitive Deficits via TREM2 Up-Regulation.

Sleep deprivation (SD) has been associated with several adverse effects, including cognitive deficit. Emerging evidence suggests microglia-associated neuroinflammation is a potential trigger of cognitive deficit after SD. Stimulator of interferon genes (STING) constitutes an important factor in host immune response to pathogenic organisms and is found in multiple cells, including microglia. STING is involved in neuroinflammation during neuronal degeneration, although how STING signaling affects SD-induced neuroinflammation remains unexplored. In the present study, the chronic sleep restriction (CSR) model was applied to examine the effects of STING signaling on cognition. The results revealed that cGAMP, a high-affinity and selective STING agonist, significantly improved cognitive deficit, alleviated neural injury, and relieved neuroinflammation in CSR mice by activating the STING-TBK1-IRF3 pathway. Moreover, triggering receptor expressed on myeloid cells 2 (TREM2) was upregulated in CSR mice treated with cGAMP, and this effect was abolished by STING knockout. TREM2 upregulation induced by cGAMP regulated the microglia from pro-inflammatory state to anti-inflammatory state, thereby relieving neuroinflammation in CSR mice. These findings indicate cGAMP-induced STING signaling activation alleviates SD-associated neuroinflammation and cognitive deficit by upregulating TREM2, providing a novel approach for the treatment of SD-related nerve injury.

WNT Co-Receptor LRP6 Is Critical for Zygotic Genome Activation and Embryonic Developmental Potential by Interacting with Oviductal Paracrine Ligand WNT2.

Mammalian preimplantation development depends on the interaction between embryonic autocrine and maternal paracrine signaling. Despite the robust independence of preimplantation embryos, oviductal factors are thought to be critical to pregnancy success. However, how oviductal factors regulate embryonic development and the underlying mechanism remain unknown. In the present study, focusing on WNT signaling, which has been reported to be essential for developmental reprogramming after fertilization, we analyzed the receptor-ligand repertoire of preimplantation embryonic WNT signaling, and identified that the WNT co-receptor LRP6 is necessary for early cleavage and has a prolonged effect on preimplantation development. LRP6 inhibition significantly impeded zygotic genome activation and disrupted relevant epigenetic reprogramming. Focusing on the potential oviductal WNT ligands, we found WNT2 as the candidate interacting with embryonic LRP6. More importantly, we found that WNT2 supplementation in culture medium significantly promoted zygotic genome activation (ZGA) and improved blastocyst formation and quality following in vitro fertilization (IVF). In addition, WNT2 supplementation significantly improved implantation rate and pregnancy outcomes following embryo transfer. Collectively, our findings not only provide novel insight into how maternal factors regulate preimplantation development through maternal-embryonic communication, but they also propose a promising strategy for improving current IVF systems.