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STUDY QUESTION Can multiple-site low-pass genome sequencing (GS) of products of conception (POCs) improve the detection of genetic abnormalities, especially heterogeneously distributed mosaicism and homogeneously distributed mosaicism in first-trimester miscarriage? SUMMARY ANSWER Multiple-site sampling combined with low-pass GS significantly increased genetic diagnostic yield (77.0%, 127/165) of first-trimester miscarriages, with mosaicisms accounting for 17.0% (28/165), especially heterogeneously distributed mosaicisms (75%, 21/28) that are currently underappreciated. WHAT IS KNOWN ALREADY Aneuploidies are well known to cause first-trimester miscarriage, which are detectable by conventional karyotyping and next-generation sequencing (NGS) on a single-site sampling basis. However, there are limited studies demonstrating the implications of mosaic genetic abnormalities in first-trimester miscarriages, especially when genetic heterogeneity is present in POCs. STUDY DESIGN, SIZE, DURATION This is a cross-sectional cohort study carried out at a university-affiliated public hospital. One hundred seventy-four patients diagnosed with first-trimester miscarriage from December 2018 to November 2021 were offered ultrasound-guided manual vacuum aspiration (USG-MVA) treatment. Products of conception were subjected to multiple-site low-pass GS for the detection of chromosomal imbalances. PARTICIPANTS/MATERIALS, SETTING, METHODS For each POC, multiple sites of villi (three sites on average) were biopsied for low-pass GS. Samples with maternal cell contamination (MCC) and polyploidy were excluded based on the quantitative fluorescence polymerase chain reaction (QF-PCR) results. The spectrum of chromosomal abnormalities, including mosaicism (heterogeneously distributed and homogeneously distributed) and constitutional abnormalities was investigated. Chromosomal microarray analysis and additional DNA fingerprinting were used for validation and MCC exclusion. A cross-platform comparison between conventional karyotyping and our multiple-site approach was also performed. MAIN RESULTS AND THE ROLE OF CHANCE One hundred sixty-five POCs (corresponding to 490 DNA samples) were subjected to low-pass GS. Genetic abnormalities were detected in 77.0% (127/165) of POCs by our novel approach. Specifically, 17.0% (28/165) of cases had either heterogeneously distributed mosaicism (12.7%, 21/165) or homogeneously distributed mosaicism (6.1%, 10/165) (three cases had both types of mosaicism). The remaining 60.0% (99/165) of cases had constitutional abnormalities. In addition, in the 71 cases with karyotyping performed in parallel, 26.8% (19/71) of the results could be revised by our approach. LIMITATIONS, REASONS FOR CAUTION Lack of a normal gestational week-matched cohort might hinder the establishment of a causative link between mosaicisms and first-trimester miscarriage. WIDER IMPLICATIONS OF THE FINDINGS Low-pass GS with multiple-site sampling increased the detection of chromosomal mosaicisms in first-trimester miscarriage POCs. This innovative multiple-site low-pass GS approach enabled the novel discovery of heterogeneously distributed mosaicism, which was prevalent in first-trimester miscarriage POCs and frequently observed in preimplantation embryos, but is currently unappreciated by conventional single-site cytogenetic investigations. STUDY FUNDING/COMPETING INTEREST(S) This work was supported partly by Research Grant Council Collaborative Research Fund (C4062-21GF to K.W.C), Science and Technology Projects in Guangzhou (202102010005 to K.W.C), Guangdong-Hong Kong Technology Cooperation Funding Scheme (TCFS), Innovation and Technology Fund (GHP/117/19GD to K.W.C), HKOG Direct Grant (2019.050 to J.P.W.C), and Hong Kong Health and Medical Research Fund (05160406 to J.P.W.C). The authors have no competing interests to declare. TRIAL REGISTRATION NUMBER N/A.

PURPOSE: This study was to evaluate if spent culture media (SCM) of embryos could be used as a non-invasive tool to achieve aneuploidy screening. Ploidy calls, as well as concordance rates between PGT-A results from trophectoderm (TE) and SCM, were compared. Clinical outcomes of single euploid transfers were also evaluated. METHODS: The study was conducted from March 2017 to June 2018 in a university-based ART center. SCM of day 3 to the day(s) of TE biopsy of all biopsied blastocysts were collected for testing. PGT-A results of SCM were compared with the standard results of TE, with clinical relevance and outcomes examined. RESULTS: NiPGT-A using SCM gave a sensitivity of 81.6%, specificity of 48.3%, positive predictive value of 82.6%, and negative predictive value of 46.7% in ploidy calling. The concordance rates for autosomes and sex determination were 62.1% and 82.4%, respectively. There were 14 single embryo transfer cycles of euploids as determined by TE biopsy. Clinical outcomes not only confirmed 3 false positive results from SCM but also reflected the true ploidy status of the transferred embryo in one case. If ploidy calls were dichotomized without mosaic embryos, the sensitivity and NPV would increase to 91.0% and 66.7% (p = 0.60 and p = 0.25), respectively. CONCLUSIONS: Cell-free DNA found in SCM could provide ploidy information of an embryo as in PGT-A from its TE. Given its potential to reflect the comprehensive chromosomal profile of the whole embryo, more research based on clinical outcomes is required to determine if SCM could be a reliable selection tool in PGT-A. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10815-019-01517-7) contains supplementary material, which is available to authorized users.

A three-dimensional supramolecular framework containing both left- and right-handed helixes, {[Zn(TTPA)Cl2]·1.63H2O}n (1), has been converted to a novel octanuclear cluster containing a metal–organ...

Preimplantation genetic testing for aneuploidies (PGT-A) has been controversial in its application to improve reproductive success, reduce time-to-pregnancy, and serve the intention-to-treat. Nevertheless, many in vitro fertilization (IVF) units have already introduced the service for one reason or another. Given PGT-A is not a stand-alone technique but a clinical service involving several disciplines, this mini review discussed the factors that can influence success rates when PGT-A is applied and highlighted practical issues encountered by clinicians, embryology, and genetics laboratories involved in the provision of PGT-A service.

Background and objectives Previous studies have shown that integrins alpha5beta1 (ITGA5B1) gene-modified rat bone marrow mesenchymal stem cells (rBMSCs) could prevent cell anoikis and increase the nitric oxide (NO) production. Here we examined the capability of rBMSCs/ITGA5B1 on the phenotype modulation of Human Pulmonary Artery Smooth Muscle Cell (HPASMC) in vitro. Methods and results The synthetic (dedifferentiated) phenotype of HPASMC was induced by monocrotaline (MCT, 1μM) for 24 h and then co-cultured with rBMSCs/ITGA5B1 in a transwell culture system. The activation of NO/cGMP (nitric oxide/Guanosine-3', 5'-cyclic monophosphate) signaling was investigated in HPASMC. The changes of pro-inflammatory factors, oxidative stress, vasodilator, vasoconstrictor, contractile and synthetic genes, and the morphological changes of HPASMC were investigated. The results of this study showed that the NO/cGMP signal, endothelial nitric oxide synthase (eNOS) expression, the expression of the vasoprotective genes heme oxygenase-1 (HMOX1) and prostaglandin-endoperoxide synthase 2 (PTGS2) were increased, but the expression of transforming growth factor-β1 (TGF-β1), CCAAT/enhancer-binding proteins delta (Cebpd), Kruppel-like factor 4 (KLF4), and activating transcription factor 4 (ATF4) were reduced in MCT treated HPASMC co-cultured with rBMSCs/ITGA5B1. The synthetic smooth muscle cells (SMCs) phenotype markers thrombospondin-1, epiregulin and the vasoconstrictor endothelin (ET)-1, thromboxane A2 receptor (TbxA2R) were down-regulated, whereas the contractile SMCs phenotype marker transgelin expression was up-regulated by rBMSCs/ITGA5B1. Furthermore, rBMSCs/ITGA5B1 promoted the morphological restoration from synthetic (dedifferentiation) to contractile (differentiation) phenotype in MCT treated HPASMC. Conclusions rBMSCs/ITGA5B1 could inhibit inflammation and oxidative stress related genes to promote the HPASMC cell differentiation by activation NO/cGMP signal.

Chromosomal mosaicism is at high occurrence in early developmental-stage embryos, but much lower in those at prenatal stage. Recent studies provided evidence on the viability of mosaic embryos by reporting pregnancy outcomes. Expanded research is warranted to evaluate its clinical significance. This is a multi-center prospective cohort study on 137 mosaic, 476 euploid and 835 non-preimplantation genetic testing (non-PGT) embryos from three in vitro fertilization (IVF) providers of three countries in Asia, applying the same preimplantation genetic testing for aneuploidies (PGT-A) reporting criteria. Mosaic embryo transfers (METs) resulted in a significantly lower clinical pregnancy rate (40.1% versus 59.0% versus 48.4%), lower ongoing/live birth rate (27.1% versus 47.0% versus 35.1%) and higher miscarriage rate (33.3% versus 20.5% versus 27.4%) than euploid and non-PGT transfers, respectively. Pregnancy losses after METs were different between embryos carrying numerical and segmental chromosomal abnormalities (p = 0.04). Our meta-analysis concluded that METs gave rise to pregnancies but were associated with a reduced ongoing/live birth rate and a higher miscarriage rate. All 37 MET live births were confirmed viable, among which 8 completed prenatal genetic testing with normal results. Longitudinal investigation on one MET pregnancy evidenced the aneuploidy depletion hypothesis. This is the first multi-center prospective study reporting a full MET pregnancy outcome with complementary information from prenatal genetic testing as compared to euploid and non-PGT cohorts.

Background Cell based therapy has been heralded as a novel, promising therapeutic strategy for cardiovascular diseases including pulmonary arterial hypertension (PAH). However, the low survival rate after transplantation due to cell death via anoikis is a major obstacle in stem cell therapy. Cells adhesion via Integrin alpha5beta1 (ITGA5B1) has a tendency to exert higher maximum forces. The present study aimed to evaluate the potential protective effect of ITGA5B1 on rat bone marrow mesenchymal stem cells (rBMSCs) from anoikis. Methods Mononuclear cells were isolated by density gradient centrifugation with Ficoll, and rBMSCs cell surface markers were evaluated by flow cytometry. Osteogenic and adipocyte differentiation was determined by Alizarin Red S and Oil Red O staining respectively. The expression of Integrin A5 (ITGA5), Integrin B1 (ITGB1), eNOS and actived-caspase-3 mRNA or protein was confirmed by qPCR and western-blot. Cell adhesion, cell viability, anoikis and the migration of rBMSCs were also evaluated. Nitric oxide (NO) production was detected by the greiss assay. Results Co-infected with Integrin A5 and B1 lentivirus to rBMSCs increased ITGA5 and ITGB1 mRNA and protein expression. ITGA5B1 enhanced the cell adhesion, cell viability, cell migration and NO production but reduced the cell anoikis in rBMSCs/ITGA5B1 groups. Conclusion Transduction of rat rBMSCs with ITGA5B1 lentivirus could prevent cell anoikis and increase NO production.

Intrapuparial development is a special pattern of metamorphosis in cyclorrhaphous flies, in which the pupa forms in an opaque, barrel-like puparium. This has been well studied in forensic insects for age estimations. In this study, the intrapuparial development of a quarantine agricultural pest, Bactrocera dorsalis (Hendel), was studied under a constant temperature of 27 &plusmn, 1 &deg, C and 70 &plusmn, 5% relative humidity. Results showed that intrapuparial development could be divided into five stages: Larval-pupal apolysis, cryptocephalic pupa, phanerocephalic pupa, pharate adult, and emergent adult. It lays a morphology-based foundation for molecular mechanism studies and enhances the understanding of the physiological basis for changes in intrapuparial development. More importantly, the chronology of intrapuparial development can be used to predict the emergence time of tephritid flies, indicating when to spray insecticides to control these phytophagous agricultural pests. This may be an effective approach to reduce the use of insecticides and slow down the evolution of insecticidal resistance.

Peptidoglycans (PGNs) are major bacterial components recognized by the immune systems of insects and mammals. PGN recognition proteins (PGRPs) are widely distributed and highly conserved in vertebrates and invertebrates. PGRPs are a family of pattern recognition receptors that recognize peptidoglycan and regulate immune responses. In this study, we cloned two PGRP genes (BdPGRP-SA and BdPGRP-SD) from Bactrocera dorsalis (Hendel), which encode 192 and 196 amino acid residues, respectively. Both genes were highly expressed in adults, especially in the fat body and midgut. These two genes were up-regulated when challenged by the immune triggers, PGN-EB (Escherichia coli O111:B4) and PGN-SA (Staphylococcus aureus). The suppression of transcriptional expression of either gene by RNA interference (RNAi) resulted in increased sensitivities to Gram-negative E. coli and Gram-positive S. aureus PGNs. Suppression of BdPGRP-SA and -SD expression by RNAi resulted in weak expressions of four antimicrobial peptides (AMPs) upon injected with E. coli or S. aureus. BdPGRP-SA and -SD are involved in recognizing both Gram-negative and Gram-positive bacteria independently to activate the downstream AMP&rsquo, s response to bacterial infection.

Glutamine synthetase (GS) is a key enzyme in glutamine synthesis and is associated with multiple physiological processes in insects, such as embryonic development, heat shock response, and fecundity regulation. However, little is known about the influence of GS on female fecundity in the oriental fruit fly, Bactrocera dorsalis. Based on the cloning of BdGSs, mitochondrial BdGSm and cytoplasmic BdGSc, we determined their expressions in the tissues of adult B. dorsalis. BdGSm was highly expressed in the fat body, while BdGSc was highly expressed in the head and midgut. Gene silencing by RNA interference against two BdGSs isoforms suppressed target gene expression at the transcriptional level, leading to a reduced ovarian size and lower egg production. The specific inhibitor L-methionine S-sulfoximine suppressed enzyme activity, but only the gene expression of BdGSm was suppressed. A similar phenotype of delayed ovarian development occurred in the inhibitor bioassay. Significantly lower expression of vitellogenin and vitellogenin receptor was observed when GS enzyme activity was suppressed. These data illustrate the effects of two GS genes on adult fecundity by regulating vitellogenin synthesis in different ways.

Spontaneous bursts of activity in developing sensory pathways promote maturation of neurons, refinement of neuronal connections, and assembly of appropriate functional networks. In the developing auditory system, inner hair cells (IHCs) spontaneously fire Ca(2+) spikes, each of which is transformed into a mini-burst of action potentials in spiral ganglion neurons (SGNs). Here we show that NMDARs are expressed in SGN dendritic terminals and play a critical role during transmission of activity from IHCs to SGNs before hearing onset. NMDAR activation enhances glutamate-mediated Ca(2+) influx at dendritic terminals, promotes repetitive firing of individual SGNs in response to each synaptic event, and enhances coincident activity of neighboring SGNs that will eventually encode similar frequencies of sound. Loss of NMDAR signaling from SGNs reduced their survival both in vivo and in vitro, revealing that spontaneous activity in the prehearing cochlea promotes maturation of auditory circuitry through periodic activation of NMDARs in SGNs.

Background. Persistent postural-perceptual dizziness (PPPD) is a common vestibular disorder. This study was conducted to assess whether the addition of cognitive behavior therapy (CBT) could significantly improve the efficacy and acceptability of sertraline in treating PPPD. Methods. PPPD patients were recruited and randomly assigned to control and experiment groups. Patients in both groups received sertraline 50–200 mg/day, and only patients in the experiment group received CBT (twice a week, one hour per time). The treatment was continued for eight weeks. At baseline, week 2, week 4, and week 8, the 25-item Dizziness Handicap Inventory (DHI), Hamilton Anxiety Rating Scale (HARS), and Hamilton Depression Rating Scale (HDRS) were used to assess the self-perceived handicapping effects caused by PPPD, anxiety, and depressive symptoms, respectively. The dose of sertraline used and the adverse events in both groups were recorded and analyzed. Results. In total, 91 PPPD patients were randomly assigned to the control group n=45 and experiment group n=46. After eight weeks of treatment, the average DHI scores, HDRS scores, and HARS scores were significantly decreased in both groups. But compared to the control group, the experiment group had significantly lower average DHI score, HDRS score, and HARS score at weeks 4 and 8. Moreover, the dose of sertraline used in the experiment group was significantly lower than that in the control group, and adverse events occurred more frequently in the control group than in the experiment group (48.9% versus 26.1%, p=0.025). Conclusion. These results demonstrated that the addition of CBT could significantly improve the efficacy and acceptability of sertraline in treating PPPD and reduce the dose of sertraline used.

Background: This study was aimed to investigate whether osteoblasts from diabetic patients have a promoting effect on osteogenesis of human umbilical cord mesenchymal stem cells (HUMSCs). Methods: HUMSCs were co-cultured with osteoblasts of diabetic and non-diabetic patients. Morphological appearance and cytochemical characteristics of the non-diabetic osteoblasts and diabetic osteoblasts were observed by hematoxylin-eosin staining, type I collagen protein expression, alkaline phosphatase (ALP) staining and Alizarin Red S staining. Cell viability, type I collagen protein expression, ALP activity and osteocalcin mRNA expression in HUMSCs were investigated. Results: Compared with negative control group, the cell proliferation, type I collagen protein expression, ALP activity and osteocalcin mRNA were increased in HUMSCs co-cultured with diabetic and non-diabetic osteoblasts (P0.05). Conclusions: Similar to osteoblasts from non-diabetic patients, osteoblasts from diabetic patients also have the ability to promote HUMSCs proliferation, and leading to HUMSCs exhibit some characteristic of osteoblasts.

Hearing loss leads to a host of cellular and synaptic changes in auditory brain areas that are thought to give rise to auditory perception deficits such as temporal processing impairments, hyperacusis, and tinnitus. However, little is known about possible changes in synaptic circuit connectivity that may underlie these hearing deficits. Here, we show that mild hearing loss as a result of brief noise exposure leads to a pronounced reorganization of local excitatory and inhibitory circuits in the mouse inferior colliculus. The exact nature of these reorganizations correlated with the presence or absence of the animals9 impairments in detecting brief sound gaps, a commonly used behavioral sign for tinnitus in animal models. Mice with gap detection deficits (GDDs) showed a shift in the balance of synaptic excitation and inhibition that was present in both glutamatergic and GABAergic neurons, whereas mice without GDDs showed stable excitation–inhibition balances. Acoustic enrichment (AE) with moderate intensity, pulsed white noise immediately after noise trauma prevented both circuit reorganization and GDDs, raising the possibility of using AE immediately after cochlear damage to prevent or alleviate the emergence of central auditory processing deficits. SIGNIFICANCE STATEMENT Noise overexposure is a major cause of central auditory processing disorders, including tinnitus, yet the changes in synaptic connectivity underlying these disorders remain poorly understood. Here, we find that brief noise overexposure leads to distinct reorganizations of excitatory and inhibitory synaptic inputs onto glutamatergic and GABAergic neurons and that the nature of these reorganizations correlates with animals9 impairments in detecting brief sound gaps, which is often considered a sign of tinnitus. Acoustic enrichment immediately after noise trauma prevents circuit reorganizations and gap detection deficits, highlighting the potential for using sound therapy soon after cochlear damage to prevent the development of central processing deficits.

Zinc-finger protein 750 (ZNF750) encodes a putative C2H2 zinc finger protein and is typically mutated or deleted in squamous cell carcinoma. The role of ZNF750 in oral squamous cell carcinoma (OSCC) remains unknown. The aim of the present study was to investigate the effects of ZNF750 overexpression in CAL-27 cells. Cell viability, and the expression of genes associated with proliferation, differentiation and the epithelial-mesenchymal transition were investigated in CAL-27 cells following ZNF750 overexpression, using Cell Counting kit-8, reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. In addition, scratch wound, invasion and migration assays were performed. Cell viability, matrix metalloproteinase 28 expression, cyclin B1 expression and mesenchymal marker neural cadherin expression were decreased following ZNF750 overexpression compared with the control groups. ZNF750 overexpression induced the differentiation-associated genes late cornified envelope 3A and small proline-rich protein 1A and upregulated the expression of late epidermal differentiation factor Kruppel-like factor 4. Overexpression of ZNF750 in CAL-27 cells resulted in inhibition of cell invasion and migration. Taken together, these data suggest that ZNF750 may inhibit the metastasis of OSCC.

Tree-like hierarchical structure is one of the key features in many real complex systems. To investigate its properties, a deterministic tree-like hierarchical network model is proposed. Next, the static properties of the tree-like hierarchical networks are discussed. The simulation and theoretical results prove that the artificial tr ee-like networks conformably possess small-world and scale- free properties well. Furthermore, the dynamic cascading failures in the tree-like hierarchical networks are investigated. A weighted tree-like cascading failure model is proposed, and the impacts of topological structure on the network robustness are investigated by a set of illustrative simulations.

This study was aimed to investigate the effect of down-regulating the CXC chemokine receptor-4 (CXCR4) expression on cell proliferation, invasion and migration of human ovarian cancer cell line SW626. The CXCR4 specific short hairpin RNA (shRNA) plasmid vector was constructed and then transfected into the SW626 cells. The expression of CXCR4 mRNA and protein was detected by real-time RT-PCR and western blot respectively. Cell proliferation was detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Cell invasion and migration was assayed in Biocoat Matrigel invasion chambers. The expression level of CXCR4 in SW626 cell transfected with CXCR4-siRNA was inhibited, leading to significant decrease in SW626 cell proliferation, invasion and migration. We conclude that CXCR4 is essential for tumor cell proliferation and invasion. The CXCR4 molecule is a potential therapeutic target to control ovarian cancer cell growth or metastasis.

This study was designed to investigate the function of 17β-estradiol (17β-E2) against oxidative stress on the cell death of mice bone marrow mesenchymal stem cells (BMSCs) induced by hydrogen peroxide (H₂O₂). BMSCs were treated with 17β-E2 for 24h and then treated with 100μM H₂O₂ for 1h. Cell viability, apoptosis, caspase-9 mRNA, JNKs (Jun N-terminal kinases) and c-Jun protein expression in BMSCs were evaluated. Cell apoptosis of BMSCs were increased in a dose-dependent manner after treated with H₂O₂ compared to control group. But pretreatment with 17β-E2 can inhibit apoptosis of BMSCs, preserve the mitochondrial transmembrane potential, decrease caspase-9 mRNA, JNK1/2 and c-Jun protein expression. In conclusion, 17β-E₂ exerts antiapoptotic effects in BMSCs which related to the mitochondria death pathway and JNKs pathway. The study revealed that 17β-E₂ can reduce the donor stem cells damage.

Background Proteasome inhibitor Carbobenzoxy-Leu-Leu-leucinal (MG132) induces the unfolded protein response (UPR) in oral squamous cell carcinoma (OSCC). X-box binding protein 1 (XBP1) is a key UPR component that regulates endoplasmic reticulum stress (ER) homeostasis. This study was aimed to investigate the activation of IRE1α-TRAF2-ASK1-JNK pathway by silencing the XBP1 expression in an OSCC cell line. Methods The XBP1 specific short hairpin RNA (shRNA) plasmid vector was constructed and then transfected into the Tca-8113 cells. The effect of XBP-1 gene silencing on IRE1α-TRAF2-ASK1-JNK pathway under MG132 induced endoplasmic reticulum stress in Tca-8113 were investigated by real-time RT-PCR or western blot. Cell apoptosis was detected by flow cytometry. Results XBP1 expression was reduced in transfected groups and MG132 groups. shRNA-XBP1 induces IRE1α-TRAF2-ASK1 signaling activation to activate pro-apoptotic ASK1-JNK signaling. Moreover, combined shRNA-XBP1 with MG132 further enhanced downregulated XBP1 expression and upregulated activation of ASK1-JNK signaling. Conclusions Silencing XBP1 expression under MG132 induced ER stress block the XBP1 survival pathway and synergism with MG132 to promote Tca8113 cell apoptosis. These findings provide a therapeutic option in oral squamous cell carcinoma by inhibition of proteasome and XBP1 splicing.

The aim of this study was to investigate the apoptotic effect of a proteasome inhibitor MG-132 on Tca-8113, a cell line of human tongue squamous cell carcinoma. Tca-8113 cells were treated with 10, 20, and 30μM of MG-132, or 5μM thapsigargin. Apoptosis rate was determined with annexin V/propidium iodide double staining. Expression of E3ubiquitin-protein ligase was determined by ELISA, and Grp78 and caspase-12 mRNA, and Grp78 and caspase-12 protein was assessed by RT-PCR and Western blot, respectively. Apoptosis was observed 18h after MG-132 treatment. The apoptotic rate in the 10, 20, and 30μM MG-132 group was 13.5, 19.6 and 34.7%, respectively, which was higher than in the thapsigargin (8.5%, P

Sulfur dioxide (SO2), a gaseous signaling molecule in animal cells, has recently been found to play a physiological role in plants. Here we studied the role of SO2 in gibberellic acid (GA3)-induced programmed cell death (PCD) in barley (Hordeum vulgare L.) aleurone layers. The application of the SO2 donor (NaHSO3/Na2SO3, 1:3 M/M) effectively alleviated PCD in barley aleurone layers in a dose-dependent manner with an optimal concentration of 50 μM. Further investigations showed that SO2 reduced the accumulation of hydrogen peroxide (H2O2), superoxide anion (⋅O2−) and malondialdehyde (MDA) in aleurone layers. Moreover, the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and guaiacol peroxidase (POD) were enhanced by SO2 donor treatment. Meanwhile, lipoxygenase (LOX) activity was attenuated by SO2 donor treatment. Furthermore, an induction of endogenous H2S and NO were also observed in SO2-treated aleurone layers, suggesting interactions of SO2 with other well-known signaling molecules. Taken together, we show that SO2 negatively regulated PCD by acting as an antioxidant to scavenge excessive reactive oxygen species (ROS) generated during PCD.

Background Nitric oxide (NO) is generated in endothelial cells by endothelial nitric oxide synthase (eNOS). Caveolin-1 (Cav1) inhibits eNOS function and NO production. Modifying Cav1 scaffold domain, in particular Phenylalanine at position 92 (F92) is critical for the inhibitory actions of Cav1 toward eNOS. The aims of this study were to investigate the effect of enhanced NO production in term of in vitro angiogenesis on rat bone marrow derived mesenchymal stem cells (BMSCs) transduced with a novel bicistronic lentiviral vector co-expressing eNOS and mutant Cav1 (F92A). Methods A bicistronic eNOS/F92-Cav1 lentiviral vector was constructed, and used to transduce rat BMSCs. The expression of eNOS and VEGF protein were confirmed by western-blot. NO production was detected by the greiss assay and in vitro angiogenesis was assessed by matrigel assisted capillary tube formation. The cell viability was evaluated using a Cell Counting Kit (CCK)-8. Results The bicistronic eNOS/F92A-Cav1 lentiviral vector increased eNOS and VEGF protein expression, NO production compared to controls. In vitro capillary formation was increased in eNOS-F92A transduced cells and cell viability was not affected by transduction. Conclusion Transduction of rat BMSCs with an eNOS-F92A-Cav1 lentiviral vector can increase NO production by enhancing eNOS protein expression. The increased NO production did not reduce cell viability. This study demonstrates that genetic modification of BMSCs to enhance NO producton could be applied in stem cell based therapeutic approaches to treat diseases such as pulmonary arterial hypertension (PAH) which is characterized by decreased endothelial NO release.

H2S is a signaling molecule in plants and animals. Here we investigated the effects of H2S on programmed cell death (PCD) in barley (Hordeum vulgareL.) aleurone layers. The H2S donor NaHS significantly delayed PCD in aleurone layers isolated from imbibed embryoless barley grain. NaHS at 0.25 mM effectively reduced the accumulation of superoxide anion (·O2-), hydrogen peroxide (H2O2), and malondialdehyde (MDA), promoted the activity of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and decreased those of lipoxygenase (LOX) in isolated aleurone layers. Quantitative-PCR showed that NaHS treatment of aleurone tissue led to enhanced transcript levels of the antioxidant genesHvSOD1, HvAPX, HvCAT1, andHvCAT2and repressed transcript levels ofHvLOX(lipoxygenase gene) and of two cysteine protease genesHvEPAandHvCP3-31. NaHS treatment in gibberellic acid- (GA-) treated aleurone layers also delayed the PCD process, reduced the content of·O2-, and increased POD activity while decreasing LOX activity. Furthermore,α-amylase secretion in barley aleurone layers was enhanced by NaHS treatment regardless of the presence or absence of GA. These data imply that H2S acted as an antioxidant in delaying PCD and enhancesα-amylase secretion regardless of the presence of GA in barley aleurone layers.

Exposure of Tca-8113 cells to proteasome inhibitor carbobenzoxy-Leu-Leu-leucinal (MG-132) causing apoptosis is associated with endoplasmic reticulum (ER) stress. X-box-binding protein-1 (XBP1) is an important regulator of a subset of genes active during ER stress, which is related to cell survival and is required for tumor growth. The present study is to evaluate the effect of MG-132 on ROS production, XBP1 gene expression, tumor necrosis factor receptor-associated factor 2 (TRAF2), ASK1 and c-jun protein expression in tongue squamous cell carcinoma cell line Tca-8113 cells. ROS production was measured by reactive oxygen species assay. X-box binding protein-1 (XBP1) mRNA was analyzed by real-time-PCR, TRAF2, ASK1 and c-jun protein were investigated by western blot and immunocytochemistry respectively. The result indicated that ROS production, TRAF2, ASK1 and c-jun were elevated in MG-132 treated cells. Giving ROS scavenger N-acetyl-L-cysteine (NAC) largely prevented the effects of MG-132. Furthermore, treating with MG-132 lead to decreased XBP1 mRNA expression but could not completely block the expression of XBP1. Taken together, these findings provide the evidence that MG-132 induced ER stress lead to Tca-8113 cells apoptosis through ROS generation and TRAF2-ASK1-JNK signal pathway activation.

The cloning, using a PCR approach, of genes from both Streptomyces coelicolor and Streptomyces avermitilis encoding an acyl-CoA dehydrogenase (AcdH), putatively involved in the catabolism of branched-chain amino acids, is reported. The deduced amino acid sequences of both genes have a high similarity to prokaryotic and eukaryotic short-chain acyl-CoA dehydrogenases. When the S. coelicolor and S. avermitilis acyl-CoA dehydrogenase genes (acdH) were expressed in Escherichia coli, each of the AcdH flavoproteins was able to oxidize the branched-chain acyl-CoA derivatives isobutyryl-CoA, isovaleryl-CoA and cyclohexylcarbonyl-CoA, as well as the short straight-chain acyl-CoAs n-butyryl-CoA and n-valeryl-CoA in vitro. NMR spectral data confirmed that the oxidized product of isobutyryl-CoA is methacrylyl-CoA, which is the expected product at the acyl-CoA dehydrogenase step in the catabolism of valine in streptomycetes. Disruption of the S. avermitilis acdH produced a mutant unable to grow on solid minimal medium containing valine, isoleucine or leucine as sole carbon sources. Feeding studies with 13C triple-labelled isobutyrate revealed a significant decrease in the incorporation of label into the methylmalonyl-CoA-derived positions of avermectin in the acdH mutant. In contrast the mutation did not affect incorporation into the malonyl-CoA-derived positions of avermectin. These results are consistent with the acdH gene encoding an acyl-CoA dehydrogenase with a broad substrate specificity that has a role in the catabolism of branched-chain amino acids in S. coelicolor and S. avermitilis.

A homolog of the mmsA gene of Pseudomonas aeruginosa, which encodes methylmalonic acid semialdehyde dehydrogenase (MSDH) and is involved in valine catabolism in pseudomonads and mammals, was cloned and sequenced from Streptomyces coelicolor. Of the two open reading frames (ORFs) found, which are convergently transcribed and separated by a 62-nucleotide noncoding region, the deduced amino acid sequence of the msdA ORF (homologous to mmsA) is similar to a variety of prokaryotic and eukaryotic aldehyde dehydrogenases that utilize NAD+, particularly to the MmsA protein from P. aeruginosa. No significant similarity was found between the deduced product of ORF1 and known proteins in the databases. An S. coelicolor msdA mutant, constructed by insertion of a hygromycin resistance gene (hyg) into the msdA coding region, lost the MSDH activity and the ability to grow in a minimal medium with valine or isobutyrate as the sole carbon source but grew on propionate. The msdA::hyg mutation was complemented by introduction of the msdA gene on a plasmid. When the S. coelicolor msdA gene was overexpressed in Escherichia coli under the control of the T7 promoter, a protein of 51-kDa, corresponding to the approximate mass of the predicted S. coelicolor msdA product (52.6 kDa), and specific MSDH activity were detected. These results strongly suggest that msdA indeed encodes the MSDH that is involved in valine catabolism in S. coelicolor.

For millennia, selective breeding, on the basis of biparental mating, has led to the successful improvement of plants and animals to meet societal needs1. At a molecular level, DNA shuffling mimics, yet accelerates, evolutionary processes, and allows the breeding and improvement of individual genes and subgenomic DNA fragments. We describe here whole-genome shuffling; a process that combines the advantage of multi-parental crossing allowed by DNA shuffling with the recombination of entire genomes normally associated with conventional breeding. We show that recursive genomic recombination within a population of bacteria can efficiently generate combinatorial libraries of new strains. When applied to a population of phenotypically selected bacteria, many of these new strains show marked improvements in the selected phenotype. We demonstrate the use of this approach through the rapid improvement of tylosin production from Streptomyces fradiae. This approach has the potential to facilitate cell and metabolic engineering and provide a non-recombinant alternative to the rapid production of improved organisms.

The developing cochlea of mammals contains a large group of columnar-shaped cells, which together form a structure known as Kölliker's organ. Prior to the onset of hearing, these inner supporting cells periodically release adenosine 5'-triphosphate (ATP), which activates purinergic receptors in surrounding supporting cells, inner hair cells and the dendrites of primary auditory neurons. Recent studies indicate that purinergic signaling between inner supporting cells and inner hair cells initiates bursts of action potentials in auditory nerve fibers before the onset of hearing. ATP also induces prominent effects in inner supporting cells, including an increase in membrane conductance, a rise in intracellular Ca(2+), and dramatic changes in cell shape, although the importance of ATP signaling in non-sensory cells of the developing cochlea remains unknown. Here, we review current knowledge pertaining to purinergic signaling in supporting cells of Kölliker's organ and focus on the mechanisms by which ATP induces changes in their morphology. We show that these changes in cell shape are preceded by increases in cytoplasmic Ca(2+), and provide new evidence indicating that elevation of intracellular Ca(2+) and IP(3) are sufficient to initiate shape changes. In addition, we discuss the possibility that these ATP-mediated morphological changes reflect crenation following the activation of Ca(2+)-activated Cl(-) channels, and speculate about the possible functions of these changes in cell morphology for maturation of the cochlea.

Cortical neurons form specific circuits, but the functional structure of this microarchitecture and its relation to behaviour are poorly understood. Two-photon calcium imaging can monitor activity of spatially defined neuronal ensembles in the mammalian cortex. Here we applied this technique to the motor cortex of mice performing a choice behaviour. Head-fixed mice were trained to lick in response to one of two odours, and to withhold licking for the other odour. Mice routinely showed significant learning within the first behavioural session and across sessions. Microstimulation and trans-synaptic tracing identified two non-overlapping candidate tongue motor cortical areas. Inactivating either area impaired voluntary licking. Imaging in layer 2/3 showed neurons with diverse response types in both areas. Activity in approximately half of the imaged neurons distinguished trial types associated with different actions. Many neurons showed modulation coinciding with or preceding the action, consistent with their involvement in motor control. Neurons with different response types were spatially intermingled. Nearby neurons (within approximately 150 mum) showed pronounced coincident activity. These temporal correlations increased with learning within and across behavioural sessions, specifically for neuron pairs with similar response types. We propose that correlated activity in specific ensembles of functionally related neurons is a signature of learning-related circuit plasticity. Our findings reveal a fine-scale and dynamic organization of the frontal cortex that probably underlies flexible behaviour.

The cloning, using a PCR approach, of genes from both Streptomyces coelicolor and Streptomyces avermitilis encoding an acyl-CoA dehydrogenase (AcdH), putatively involved in the catabolism of branched-chain amino acids, is reported. The deduced amino acid sequences of both genes have a high similarity to prokaryotic and eukaryotic short-chain acyl-CoA dehydrogenases. When the S. coelicolor and S. avermitilis acyl-CoA dehydrogenase genes (acdH) were expressed in Escherichia coli, each of the AcdH flavoproteins was able to oxidize the branched-chain acyl-CoA derivatives isobutyryl-CoA, isovaleryl-CoA and cyclohexylcarbonyl-CoA, as well as the short straight-chain acyl-CoAs n-butyryl-CoA and n-valeryl-CoA in vitro. NMR spectral data confirmed that the oxidized product of isobutyryl-CoA is methacrylyl-CoA, which is the expected product at the acyl-CoA dehydrogenase step in the catabolism of valine in streptomycetes. Disruption of the S. avermitilis acdH produced a mutant unable to grow on solid minimal medium containing valine, isoleucine or leucine as sole carbon sources. Feeding studies with 13C triple-labelled isobutyrate revealed a significant decrease in the incorporation of label into the methylmalonyl-CoA-derived positions of avermectin in the acdH mutant. In contrast the mutation did not affect incorporation into the malonyl-CoA-derived positions of avermectin. These results are consistent with the acdH gene encoding an acyl-CoA dehydrogenase with a broad substrate specificity that has a role in the catabolism of branched-chain amino acids in S. coelicolor and S. avermitilis.