OBJECTIVE:Osteoporosis is a progressive systemic skeletal disorder. Multiple profiling studies have contributed to characterizing biomarkers and therapeutic targets for osteoporosis. However, due to the limitation of the platform of miRNA sequencing, only a part of miRNA can be sequenced based on one platform.MATERIALS AND METHODS:In this study, we performed miRNA sequencing in osteoporosis bone samples based on a novel platform Illumina Hiseq 2500. Bioinformatics analysis was performed to construct osteoporosis-related competing endogenous RNA (ceRNA) networks. Gene interference and osteogenic induction were used to examine the effect of identified ceRNA networks on osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (HBMSCs).RESULTS:miR-1303 was lowly expressed, while cochlin (COCH) and KCNMA1-AS1 were highly expressed in the osteoporosis subjects. COCH knockdown improved the osteogenic differentiation of HBMSCs. Meanwhile, COCH inhibition compensated for the suppression of osteogenic differentiation of HBMSCs by miR-1303 knockdown. Further, KCNMA1-AS1 knockdown promoted osteogenic differentiation of HBMSCs through downregulating COCH by sponging miR-1303.CONCLUSIONS:Our findings suggest that the KCNMA1-AS1/miR-1303/COCH axis is a promising biomarker and therapeutic target for osteoporosis.
Assessing individual aging has always been an important topic in aging research. Caenorhabditis elegans (C. elegans) has a short lifespan and is a popular model organism widely utilized in aging research. Studying the differences in C. elegans life stages is of great significance for human health and aging. In order to study the differences in C. elegans lifespan stages, the classification of lifespan stages is the first task to be performed. In the past, biomarkers and physiological changes captured with imaging were commonly used to assess aging in isogenic C. elegans individuals. However, all of the current research has focused only on physiological changes or biomarkers for the assessment of aging, which affects the accuracy of assessment. In this paper, we combine two types of features for the assessment of lifespan stages to improve assessment accuracy. To fuse the two types of features, an improved high-efficiency network (Att-EfficientNet) is proposed. In the new EfficientNet, attention mechanisms are introduced so that accuracy can be further improved. In addition, in contrast to previous research, which divided the lifespan into three stages, we divide the lifespan into six stages. We compared the classification method with other CNN-based methods as well as other classic machine learning methods. The results indicate that the classification method has a higher accuracy rate (72%) than other CNN-based methods and some machine learning methods.
As the most abundant post-translation modifications (PTMs), the phosphorylation usually occurred on the intrinsically disordered regions (IDRs). The regulation on the structures and interactions of IDRs induced by phosphorylation is critical to the function performing. The eukaryotic transcription factor 1 (Ets-1) is a member of transcription factor family, which participates in many important biological processes. The DNA-binding ability of Ets-1 is auto-inhibited by a disordered serine-rich region (SRR) on the Ets-1. The inhibition ability of SRR is greatly enhanced by the phosphorylation of the serine on the SRR. Nevertheless, the molecular mechanisms of the phosphorylation regulation on the structure and activity of Ets-1 are still unclear and under debates. By using both of the molecular simulations and biochemical experiments, we studied the molecule mechanism of phosphorylation regulation on the auto-inhibition of the Ets-1. The reasons of stabilization of Ets-1 core by phosphorylation on SRR region were elucidated. More important, the free energy landscapes (FEL) show that both of the steric hindrance and allosteric regulation are responsible for the DNA-binding inhibitory induced by phosphorylation, but the steric effects contribute greater than the allosteric regulation. The phosphorylation not only enhances the electrostatic interactions to facilitate the steric impedance, but also promotes the formation of hydrophobic residue clusters, which provide major driven force for the allosteric regulation. The structural basis of auto-inhibition of Ets-1 induced by the phosphorylation revealed in this study would great help the developing of inhibitor for the cancer therapy.
Poly-γ-glutamic acid (γ-PGA) is a multifunctional biopolymer mainly produced by Bacillus. The cofactor specificity of enzymes plays a critical role in regulating metabolic process and metabolite production. Here, we present a novel approach for switching cofactor specificity of glutamate dehydrogenase RocG from nicotinamide adenine dinucleotide phosphate (NADPH) to nicotinamide adenine dinucleotide (NADH) to improve γ-PGA production. Firstly, 3D structural modeling and molecular docking were performed to predict the binding modes of NADH and NADPH. Several site-specific mutants based on the conventional and Random Accelerated Molecular Dynamics simulations were obtained to alter cofactor specificity. Then, the effects of RocG variants overexpressions on γ-PGA production were evaluated. Compared to the wild-type, the mutant RocGD276E showed highest increase in γ-PGA yield, increased by 40.50%. Meanwhile, yields of main by-products acetoin and 2,3-butandieol were decreased by 21.70% and 16.53%, respectively. Finally, the results of enzymatic properties confirmed that glutamate dehydrogenase mutant RocGD276E exhibited the higher affinity for NADH, caused a shift in coenzyme preference from NADPH to NADH, with a catalytic efficiency comparable with NADPH-dependent RocG. Taken together, this research demonstrated that switching the cofactor preference of glutamate dehydrogenase via rational design was an effective strategy for high-level production of γ-PGA in Bacillus licheniformis.
Underwater sensor networks (UWSNs) could be more scalable with the help of autonomous underwater vehicles (AUVs) by their self-control ability. However, continuous and reliable mobile acoustic communication is the bottleneck that limits the development of AUV-aided UWSNs. This paper analyzes three typical factors that impact the AUV communications based on the lake and sea test data, i.e., the doppler effect, signal strength weakening, and multipath interference. Meanwhile, we propose improvements for AUV and acoustic modem, respectively, in terms of AUV autonomous control and intelligent technology and underwater acoustic communication technology to improve mobile acoustic communication reliability.
Stress physiology of lactic acid bacteria (LAB) is crucial to their ecological fitness and applicational implications. As a self-imposed stress, lactic acid is the major final metabolic product of LAB and its accumulation can be detrimental to bacterial cells. However, the relationship between LAB carbohydrate metabolism, the primary energy supplying bioactivities, and lactic acid stress responses is not fully understood. Pediococcus pentosaceus has been recognized as an important cell factory and demonstrated probiotic activities. This study investigated behavior of P. pentosaceus under lactic and acetic acid stresses, particularly with supplementations of metabolizable carbohydrates. Lactic and acetic acid retain similar growth stagnation effect, and both resulted in cell death in P. pentosaceus. All metabolizable carbohydrates improved bacterial survival compared to lactic acid control, while xylooligosaccharides (XOS) exerted the highest viability protective efficacy, 0.82 log CFU/mL higher population survived than other carbohydrates after 30 h of incubation. RNA-seq pipeline showcased the intensive global transcriptional responses of P. pentosaceus to lactic acid, which caused significant regulations (more than 2 Log(2) fold) of 16.5% of total mRNA coding genes. Glucose mainly led to gene suppressions (83 genes) while XOS led to gene up-regulations (19 genes) under lactic acid stress. RT-qPCR study found that RNA polymerase-centered transcriptional regulation is the primary regulatory approach in evaluated culture conditions. The synergy between lactic acid stress and carbohydrate metabolism should be attentively contemplated in future studies and applications.
Neural stem cells (NSCs) are characterized by their potential for self-renewal and ability to differentiate into neurons, astrocytes, and oligodendrocytes. They are of great value to scientific studies and clinical applications. Culturing NSCs in vitro is important for characterizing their properties under controlled environmental conditions that may be modified and monitored accurately. The present study explored a modified, detailed and efficient protocol for the isolation, culture and cryopreservation of rat embryonic NSCs. In particular, the viability, nestin expression, and self-renewal and multi-differentiation capabilities of NSCs cryopreserved for various periods of time (7 days, or 1, 6 or 12 months) were characterized and compared. Rat embryonic NSCs were successfully obtained and maintained their self-renewal and multipotent differentiation capabilities even following long-term cryopreservation (for up to 12 months).
Intrinsically disordered proteins (IDPs) are a class of proteins without stable three-dimensional structures under physiological conditions. IDPs exhibit high dynamic nature and could be described by structural ensembles. As one of the most widely used tools, molecular dynamics (MD) simulation could provide the atomic descriptions of the structural ensemble of IDPs. However, the accuracy of the MD simulation largely depends on the accuracy of the force field. In this paper, we compared the structural ensembles of the activation domain 1 (AD1) in p53 tumor suppressor obtained from the widely used force fields, AMBER99SB-ILDN, CHARMM27, CHARMM36m with different water models. The results show that CHARMM36m generates more extended conformations than other force fields, while CHARMM27 prefers to sample the [Formula: see text]-helical structure. Moreover, the chemical shifts obtained by CHARMM36m are the closest to the experimental measurements. These results indicate that the CHARMM36m force field performs best in characterizing the structure properties of p53 AD1. Water models are also critical to describe the structural ensemble of IDPs. TIP4P water model can obtain more extended conformations and produce more local helical conformations than the TIP3P model in our simulation. In addition, we also compare the chemical shifts predicted by different chemical shift predicting programs with experimental measurements, the results show that SHIFTX2 obtains the best performance in the chemical shifts prediction.
In this study, an isothermal reverse transcription-recombinase polymerase amplification (RT-RPA) assay was developed for the efficient and accurate detection of potato virus Y (PVY) under isothermal conditions. This RT-RPA assay was more efficient than the conventional reverse transcription-polymerase chain reaction (RT-PCR) assay as the amplification reaction can be completed in less than 20 min. Moreover, unlike PCR that requires a thermocycler to carry out the DNA amplification through specific temperature phases, RPA assay could be performed under an isothermal condition at a temperature ranging from 25 to 40 degrees C. A simple instrumentation such as a heating block or a water bath or even anon-instrumental condition such as human hands or a benchtop inside/outside a room during the summer could satisfy the temperature requirement of RPA. The sensitivity of this assay was equivalent to that of the conventional RT-PCR, and the virus can be detected in a minimum of 2 pg of total RNA extracted from the PVY infected potato leaf tissues. The efficacy of the newly developed RT-RPA was then evaluated using field potato leaf and dormancy-broken sprout samples upon enzyme-linked immunosorbent assay (ELISA) screening. Of the 164 PVY-ELISA-positive samples, RT-RPA detected 157 whereas simplex RT-PCR detected 160 and multiplex RT-PCR detected 154. Of the 74 randomly selected PVY-ELISA-negative samples, RT-RPA, simplex RT-PCR and multiplex RT-PCR led to 1, 1 and 0 positive detections, receptively. Overall, RT-RPA and the two RT-PCR assays as well as ELISA exhibited an agreement of 96.6-98.7%, thus demonstrating the suitability of RT-RPA for large scale detection of PVY, irrespective of the strain type of the virus.
The present study aimed to explore the role of the PTEN/Akt/mTOR signaling pathway in the neurite outgrowth and apoptosis of cortical neurons. Cortical neurons were seeded on or adjacent to chondroitin sulfate proteoglycans. The length, number and crossing behavior of the neurites were calculated. Immunohistochemical staining and TUNEL data were analyzed. Neurites treated with PTEN inhibitor exhibited significant enhancements in elongation, initiation and crossing abilities when they encountered chondroitin sulfate proteoglycans in vitro. These effects disappeared when the PTEN/Akt/mTOR signaling pathway was blocked. Neurons exhibited significant enhancements in survival ability following PTEN inhibition. The present study demonstrated that PTEN inhibition can promote axonal elongation and initiation in cerebral cortical neurons, as well as the ability to cross the chondroitin sulfate proteoglycan border. In addition, PTEN inhibition is useful for protecting the neuron from apoptosis. The PTEN/Akt/mTOR signaling pathway is an important signaling pathway.
The fate of neural stem cells (NSCs) is decided by numerous growth factors. Among these factors, the well-known angiogenic factor angiopoietin-2 (Ang-2) has been revealed to participate in neurogenesis separate from its role in angiogenesis. However, the effect of Ang-2 on the fate determination of mouse embryonic NSCs and the underlying mechanism remain unclear. This result of this study indicated that treatment of mouse embryonic NSCs with 200 ng/ml Ang-2 significantly promoted neuronal differentiation without affecting glial differentiation, and mammalian target of rapamycin (mTOR) was phosphorylated in a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent manner during this process. Rapamycin, a specific mTOR inhibitor, suppressed the increase in neuronal differentiation stimulated by Ang-2, and this suppression did not result from an effect of Ang-2 or rapamycin on the apoptosis of differentiated NSCs. Collectively, our research demonstrates that PI3K/Akt pathway-mediated mTOR phosphorylation plays an important role in the Ang-2-enhanced neuronal differentiation of mouse embryonic NSCs.
The study was carried out to evaluate if foliar ethephon application could promote photosynthesis rate of Mondo grass. Methods – Net photosynthesis rate (P n ) and stomatal conductance (g s ) of Mondo grass was measured at various time points after ethephon treatment. In addition, a full-length enriched complementary DNA (cDNA) library from ethephon (0.5 g L -1 ) treated Mondo grass leaves was constructed to explore the underlying gene expression profile. Results – Ethephon treatment (ranging from 0.2 g L -1 to 1.5 g L -1 ) reduced Mondo grass P n . Real time quantitative PCR results implied that ethephon inhibited Mondo grass leaf photosynthesis through down-regulating gene expression of Rubisco small subunit ( Rbcs ). Conclusion – Application of ethephon will not be an effective way in promoting P n of Mondo grass. Moreover, our data provide the first extensive set of full-length cDNA sequence resources for Mondo grass and these resources will be useful for important genes discovery, functional analysis and understanding various molecular mechanisms for Mondo grass.
Aim: We conducted a meta-analysis to compare the efficacy and safety of oral and intravenous applications of tranexamic acid (TXA) in total hip arthroplasty (THA). Materials & methods: Electronic databases, including PubMed, Cochrane CENTRAL, ScienceDirect and Embase, were searched to identify the studies comparing the efficacy and safety of oral and intravenous applications of TXA in THA. Relevant journals and conference proceedings were manually searched. The pooled data were analyzed using RevMan 5.1. Results: Four randomized control trials and one retrospective study were identified. A meta-analysis showed no significant differences in hemoglobin reduction, total blood loss and transfusion requirements. Conclusion: Oral applications of TXA are comparable to intravenous applications of TXA in primary unilateral THA for blood conservation and cost-saving measures.
Aim: To assess the efficiency and safety of negative pressure wound therapy (NPWT) in the total hip and knee arthroplasty, we conducted a meta-analysis from randomized controlled trials. Methods: Potential academic articles were identified from the Cochrane Library, PubMed, Embase, Springer and ScienceDirect. Secondary sources were identified from the references of the included literature. RevMan 5.1 was used to analyze the pooled data. Results: Six randomized controlled trials met the inclusion criteria. Meta-analysis showed more superficial surgical site infection and blisters in patients with total knee arthroplasty. There were no significant differences between two groups in total infection and total complications. Conclusion: NPWT decreased the incidence of superficial surgical site infection. More blisters were noticed in patients with NPWT after total knee arthroplasty.
Underwater acoustic WiFi (UWA-WiFi) network is similar to the traditional terrestrial WiFi network, which provides wireless access services for underwater nodes (e.g., marine engineering equipment, underwater vehicles, divers, sensors, and so on). MAC protocol design is an essential issue for UWA-WiFi network. Due to the natures of low available bandwidth, long and variable propagation delay, and time varying on acoustic channel, the existing MAC protocols for terrestrial WiFi network can't be directly applied to UWA-WiFi network. In this paper, we introduced customized Slotted-FAMA protocol for UWA-WiFi network. Furthermore, we did a pool experiment to testify the practicability of customized Slotted-FAMA protocol. The results of the experiment show that customized Slotted-FAMA can significantly reduce the probability of collisions and enhance the performance.
Changes in ocean temperature over time have important implications for marine ecosystems and global climate change. Marine temperature changes with time and has the features of closeness, period, and trend. This paper analyzes the temporal dependence of marine temperature variation at multiple depths and proposes a new ocean-temperature time-series prediction method based on the temporal dependence parameter matrix fusion of historical observation data. The Temporal Dependence-Based Long Short-Term Memory (LSTM) Networks for Marine Temperature Prediction (TD-LSTM) proves better than other methods while predicting sea-surface temperature (SST) by using Argo data. The performances were good at various depths and different regions.
This paper carries out a refinement on the basis of existing data sets, whose level of granularity is not available for some experimental analysis such as thermocline research. The thermocline is sensitive to thermohaline data granularity for sudden sea temperature changes. We reined the data with the KNN regression method and managed to choose the optimal parameters for the construction of a prediction model. We also refined the temperature and salinity data in BOA_Argo using the regression forecast model. The original data, whose horizontal resolution is 1 °x 1 °and vertically divided into uneven 58 layers from the sea surface to 1,975 meters underwater, has been refined into a new set with the resolution of 1 °x 1 °horizontally and 1-meter interval vertically. At each point, we reined the previously uneven 58 temperature data samples into 1,976 evenly distributed data samples. The refined data sets can be used in experimental analysis, and the validity of this method has been verified by regional data.
Existing ocean visualization studies are usually conducted independently using either sonar or optical imaging. However, they have shortcomings in different engineering applications. Acoustic imaging is not comprehensive enough to show the details of the target, and the perspective of optical imaging is not extensive enough. Combining the advantages of optics and acoustics, this paper proposes a joint imaging method with acoustic communication-assisted decision-making and optical image stitching, aiming to improve information acquisition efficiency in the ocean visualization process. The joint imaging method relies on sonar technology as the decision-making layer to obtain the position information, then it sends instructions to AUV by acoustic communication and get the details of the target by the AUV-mounted camera which forms the executive layer. Finally, it conducts smoothing and mosaic processing on the optical image. The system can efficiently obtain complete, comprehensive, and detailed ocean visualization information through the advantages of agility of acoustic and accuracy of optics.
Neural stem cells (NSCs) are self-renewing, pluripotent, and undifferentiated cells which have benefits as candidates for central nervous system (CNS) injury. However, the transplanted NSCs usually maintain their undifferentiated characteristics, or differentiated potentially along the glial lineage after transplantation. MicroRNAs (miRNAs) are small, non-coding RNAs that play key roles in cell differentiation. However, it is unknown whether miR-29a could play a role in the process of NSC's differentiation. Primary NSCs were derived from rat embryonic cortex. Lentiviral vector-mediated miR-29a (LV-miR-29a) and negative control (LV-null) were infected into NSCs. Quantitative real-time PCR was used to detect expression of miR-29a and PTEN. Immunocytochemistry was used to stain neurons, astrocytes, and oligodendrocytes. Dual luciferase assay to study the interaction between miR-29a and PTEN. The current study showed that the expression of miR-29a was upregulated during NSC differentiation, while the expression of PTEN was downregulated during NSC differentiation. After infection with LV-miR-29a, MAP-2-positive neurons significantly increased, and GFAP-positive astrocytes significantly decreased. Furthermore, we demonstrated that PTEN is a molecular target of miR-29a. miR-29a promote the neuronal differentiation and decrease the astrocytes differentiation of NSCs via targeting PTEN. This may give insight into a novel mechanism of NSC differentiation and provide a promising therapeutic target.