Antenna effect of pyridoxal phosphate on the fluorescence of mitoxantrone-silicon nanoparticles and its application in alkaline phosphatase assay.

As a kind of sensing and imaging fluorescent probe with the merit of low toxicity, good stability, and environment-friendly, silicon nanoparticles (SiNPs) are currently attracting extensive research. In this work, we obtained mitoxantrone-SiNPs (MXT-SiNPs) with green emission by one-pot synthesis under mild temperature condition. The antenna based on pyridoxal phosphate (PLP) was designed for light-harvesting to enhance the luminescence of MXT-SiNPs and to establish a novel sensing strategy for alkaline phosphatase (ALP). PLP transfers the absorbed photon energy to MXT-SiNPs by forming Schiff base. When PLP is dephosphorized by ALP, the released free hydroxyl group reacts with aldehyde group to form internal hemiacetal, which leads to the failure of Schiff base formation. Based on the relationship between antenna formation ability and PLP hydrolysis degree, the activity of ALP can be measured. A good linear relationship was obtained from 0.2 to 3.0 U/L, with a limit of detection of 0.06 U/L. Furthermore, the sensing platform was successfully used to detect ALP in human serum with recovery of 97.6-106.2%. The rational design of antenna elements for fluorescent nanomaterials can not only provide a new pathway to manipulate the luminescence, but also provide a new direction for fluorescence sensing strategy.

New photothermal immunoassay of human chorionic gonadotropin using Prussian blue nanoparticle-based photothermal conversion.

A new near-infrared-based photothermal immunosensing strategy was developed for the sensitive and feasible detection of human chorionic gonadotropin (HCG) by use of a Prussian blue nanoparticle-based photothermal conversion system. Prussian blue nanospheres synthesized by the one-pot method were used for the labeling of anti-HCG detection antibody. A sandwich-type immunoreaction was initially conducted on a monoclonal anti-HCG antibody-coated microplate with a nanoparticle-labeled signal antibody. Accompanying formation of the sandwiched immunocomplex, Prussian blue nanospheres caused photothermal conversion under 980-nm laser irradiation, thereby resulting in an increase of the temperature of the detection system measured by a portable digital thermometer. The properties and factors influencing the analytical performance of the photothermal immunoassay were studied in detail. Under the optimal conditions, the Prussian blue nanoparticle-based photothermal immunoassay exhibited good temperature responses relative to target HCG concentrations within the dynamic range of 0.01-100 ng mL-1 at a low detection limit of 5.8 pg mL-1. This system also displayed good anti-interference behavior with regard to other cancer biomarkers, good reproducibility, and relatively long storage stability. The method accuracy was evaluated for analysis of human serum specimens, giving results that matched well with those obtained with a commercial HCG enzyme-linked immunosorbent assay kit. Importantly, this protocol is promising for advanced development of photothermal immunoassays. Graphical abstract.

The association of five preoperative serum tumor markers and pathological features in patients with breast cancer.

BACKGROUND: The utility of frequently used serum tumor markers in breast cancer remains controversial. The study aimed to investigate the role of preoperative carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), cancer antigen 153 (CA153), cancer antigen 724 (CA724), and ferritin (FER) in the management of breast cancer and their relationships with pathological features. METHODS: A total of 804 patients with breast mass who underwent breast surgery and 305 healthy volunteers were enrolled. Preoperative serum levels of CEA, CA125, CA153, CA724, and FER were measured. And the pathological features of all the patients were recorded. The association of preoperative serum tumor markers and pathological features was analyzed. RESULTS: Among the 804 patients, 355 were identified as malignant cases and 449 as benign cases. CEA, CA153, and FER of patients with breast cancer were higher than those of healthy volunteer group and patients with benign breast diseases. The area under curve (AUC) of CEA, CA153, and FER for distinguishing patients with breast cancer and subjects with non-breast cancer was 0.688 (95% CI: 0.656-0.721), 0.609 (95% CI: 0.574-0.645), and 0.623 (95% CI: 0.586-0.660), respectively. CA153 correlated with tumor size, node status, and TNM stage, whereas CA125 with node status. No statistic differences of the five markers were observed among the four molecular subtypes. CONCLUSION: Preoperative levels of CEA, CA153, and FER exhibit low diagnostic accuracy for breast cancer (stage I-III). CA153 correlates with tumor burden, suggesting its prognostic value. The five serum markers do not correlate with molecular subtypes.

Scutellarin inhibits high glucose-induced and hypoxia-mimetic agent-induced angiogenic effects in human retinal endothelial cells through reactive oxygen species/hypoxia-inducible factor-1α/vascular endothelial growth factor pathway.

Scutellarin inhibits hypoxia-induced and moderately high glucose-induced proliferation and vascular endothelial growth factor (VEGF) expression in human retinal endothelial cells (HRECs); thus, it could be a potential therapy for diabetic retinopathy. However, how scutellarin inhibits VEGF is unknown. In our study, HRECs were treated with high glucose and/or hypoxia-mimetic agent cobalt chloride to stimulate cell proliferation, migration, and angiogenesis, and the effects of scutellarin on these processes were analyzed through cell viability assay, Transwell migration assay and endothelial tube formation assay, respectively. The inhibition of angiogenic factor VEGF by scutellarin was confirmed by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. The mechanisms for VEGF inhibition were examined by luciferase reporter assay, Western blot, immunoprecipitation, and biochemical assays. We found that scutellarin not only concentration-dependently inhibited cell proliferation, migration, and tube formation in HRECs but also decreased their production of VEGF. The reduction of VEGF was due to increased ubiquitination and degradation of hypoxia-inducible factor (HIF)-1α by scutellarin. Furthermore, scutellarin impaired the interaction of HIF-1α with p300, which further decreased the transcriptional activity of HIF-1α. As an inducer of HIF-1α, oxidative stress was attenuated by scutellarin. Our data demonstrate that scutellarin exhibits an antiangiogenic effect via inhibition of oxidative stress, enhancement of HIF-1α degradation, and reduction of VEGF secretion.

Amorphous bismuth and GO co-doped WO3 electrochromic film with fast-switching time and long-term stability.

The sol-gel process for fabricating electrochromic thin films is straightforward, offering advantages such as low cost and ease of compositional control. Herein we prepared GO-Bi-WO3 films with improved electrochromic performance using a simple sol-gel spin-coating method. The sample shows a fast-switching time (1.8 s for coloring and 1.8 s for bleaching), large optical modulation (85% at 630 nm), excellent stability (86.4% retention after 10 200 cycles), and high coloration efficiency (65.9 cm2 C-1). This work indicates the electrochromic performance of WO3-based films can be enhanced by incorporating GO, which provides an effective strategy for the rapid, safe, and efficient fabrication of electrochromic thin films.

A Heterogeneity-Aware Replacement Policy for the Partitioned Cache on Asymmetric Multi-Core Architectures.

In an asymmetric multi-core architecture, multiple heterogeneous cores share the last-level cache (LLC). Due to the different memory access requirements among heterogeneous cores, the LLC competition is more intense. In the current work, we propose a heterogeneity-aware replacement policy for the partitioned cache (HAPC), which reduces the mutual interference between cores through cache partitioning, and tracks the shared reuse state of each cache block within the partition at runtime to guide the replacement policy to keep cache blocks shared by multiple cores in multithreaded programs. In the process of updating the reuse state, considering the difference of memory accesses to LLC by heterogeneous cores, the cache replacement policy tends to keep cache blocks required by big cores, to better improve the LLC access efficiency of big cores. Compared with LRU and the SRCP, which are the state-of-the-art cache replacement algorithms, the performance of big cores can be significantly improved by HAPC when running multithreaded programs, while the impact on little cores is almost negligible, thus improving the overall performance of the system.

Locality-Based Cache Management and Warp Scheduling for Reducing Cache Contention in GPU.

GPGPUs has gradually become a mainstream acceleration component in high-performance computing. The long latency of memory operations is the bottleneck of GPU performance. In the GPU, multiple threads are divided into one warp for scheduling and execution. The L1 data caches have little capacity, while multiple warps share one small cache. That makes the cache suffer a large amount of cache contention and pipeline stall. We propose Locality-Based Cache Management (LCM), combined with the Locality-Based Warp Scheduling (LWS), to reduce cache contention and improve GPU performance. Each load instruction can be divided into three types according to locality: only used once as streaming data locality, accessed multiple times in the same warp as intra-warp locality, and accessed in different warps as inter-warp data locality. According to the locality of the load instruction, LWS applies cache bypass to the streaming locality request to improve the cache utilization rate, extend inter-warp memory request coalescing to make full use of the inter-warp locality, and combine with the LWS to alleviate cache contention. LCM and LWS can effectively improve cache performance, thereby improving overall GPU performance. Through experimental evaluation, our LCM and LWS can obtain an average performance improvement of 26% over baseline GPU.

Genomics Analyses Reveal Unique Classification, Population Structure and Novel Allele of Neo-Tetraploid Rice.

BACKGROUND: Neo-tetraploid rice (NTR) is a useful new germplasm that developed from the descendants of the autotetraploid rice (ATR) hybrids. NTR showed improved fertility and yield potential, and produced high yield heterosis when crossed with indica ATR for commercial utilization. However, their classification, population structure and genomic feature remain elusive. RESULTS: Here, high-depth genome resequencing data of 15 NTRs and 18 ATRs, together with 38 publicly available data of diploid rice accessions, were analyzed to conduct classification, population structure and haplotype analyses. Five subpopulations were detected and NTRs were clustered into one independent group that was adjacent to japonica subspecies, which maybe the reason for high heterosis when NTRs crossed with indica ATRs. Haplotype patterns of 717 key genes that associated with yield and other agronomic traits were revealed in these NTRs. Moreover, a novel specific SNP variation was detected in the first exon of HSP101, a known heat-inducible gene, which was conserved in all NTRs but absent in ATRs, 3KRG and RiceVarMap2 databases. The novel allele was named as HSP101-1, which was confirmed to be a heat response factor by qRT-PCR, and knockout of HSP101-1 significantly decreased the thermotolerance capacity of NTR. Interestingly, HSP101-1 was also specifically expressed in the anthers of NTR at pre-meiotic and meiosis stages under optimal environment without heat stress, and its loss-of-function mutant showed significant decrease in fertility of NTR. CONCLUSION: The construction of first genomic variation repository and the revelation of population structure provide invaluable information for optimizing the designs of tetraploid rice breeding. The detection of specific genomic variations offered useful genomic markers and new directions to resolve high fertility mechanism of NTR.

Comparative study on cytogenetics and transcriptome between diploid and autotetraploid rice hybrids harboring double neutral genes.

Double pollen fertility neutral genes, San and Sbn, can control pollen sterility in intersubspecific (indica × japonica) rice hybrids, which has excellent potential to increase rice yield. Previous studies showed that polyploidy could increase the interaction of three pollen sterility loci, i.e. Sa, Sb and Sc, which cause pollen sterility in autotetraploid rice hybrids, and hybrid fertility could be improved by double neutral genes, San and Sbn, in autotetraploid rice hybrids. We compared cytological and transcriptome data between autotetraploid and diploid rice hybrid during meiosis and single microspore stages to understand the molecular mechanism of neutral genes for overcoming pollen sterility in autotetraploid rice hybrids, which harbored double neutral genes. Cytological results revealed that the double neutral genes resulted in higher pollen fertility (76.74%) and lower chromosomal abnormalities in autotetraploid hybrid than in parents during metaphase I, metaphase II, anaphase I and anaphase II. Moreover, autotetraploid rice hybrid displayed stronger heterosis than a diploid hybrid. Compared with diploid rice hybrid, a total of 904 and 68 differently expressed genes (DEGs) were identified explicitly in autotetraploid hybrid at meiosis and single microspore stages, respectively. Of these, 133 and 41 genes were detected in higher-parent dominance and transgressive up-regulation dominance, respectively, which were considered autotetraploid potential heterosis genes, including a meiosis-related gene (Os01g0917500, MSP1) and two meiosis specific-genes (Os07g0624900 and Os04g0208600). Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes pathway (KEGG) analysis revealed that DEGs significantly enriched in amino acid metabolism and photosynthesis metabolism. These results indicated that meiosis-specific and meiosis-related genes, and amino acids and photosynthesis metabolism-related genes contribute to higher yield and pollen fertility in autotetraploid rice hybrid. This study provides a theoretical basis for molecular mechanisms of heterosis in autotetraploid rice harboring double neutral genes for pollen fertility.

Seeing the forest in order and the trees in disorder: Environmental orderliness versus disorderliness affects the perceptual processing style.

People attend to the same event or object by using a global or local processing style across different environments. Different physical environmental conditions, such as orderliness and disorderliness, activate different psychological states and produce different kinds of outcomes. However, previous work has rarely examined whether individuals exposed to different orderly or disorderly environments attend to the "global" or the "local" differently. Thus, in the current study, we conducted three behavioral experiments to directly examine the impact of disorder versus order cues on people's types of perceptual and conceptual processing (global vs. local). We asked participants to perform a typical Kimchi-Palmer figures task or a categorization task: with pre-primed disorderly or orderly physical environmental pictures (Experiment 1), with basic visual pictures (Experiment 2), and imagining a real environment (Experiment 3). The results revealed that in any of the above operations, orderly experience led to global perceptual processing, whereas disorderly experience led to local perceptual processing. This difference in processing style was not influenced by the participants' daily habits or their preference for the need for structure. However, this difference in perceptual processing style did not spill over to the conceptual processing style. These findings provide direct evidence of the effects of disorderliness versus orderliness on global versus local perceptual and conceptual processing and imply that environmental orderliness or disorderliness may functionally affect cognitive processing (i.e., how we see and think about events and objects). Thus, the findings creatively bridge several lines of research and shed light on a basic cognitive mechanism responsible for perceptions of order/disorder.

A Nano-Micro Engineering Nanofiber for Electromagnetic Absorber, Green Shielding and Sensor.

HIGHLIGHTS: The role of electron transport characteristics in electromagnetic (EM) attenuation can be generalized to other EM functional materials. The integrated functions of efficient EM absorption and green shielding open the view of EM multifunctional materials. A novel sensing mechanism based on intrinsic EM attenuation performance and EM resonance coupling effect is revealed. It is extremely unattainable for a material to simultaneously obtain efficient electromagnetic (EM) absorption and green shielding performance, which has not been reported due to the competition between conduction loss and reflection. Herein, by tailoring the internal structure through nano-micro engineering, a NiCo2O4 nanofiber with integrated EM absorbing and green shielding as well as strain sensing functions is obtained. With the improvement of charge transport capability of the nanofiber, the performance can be converted from EM absorption to shielding, or even coexist. Particularly, as the conductivity rising, the reflection loss declines from - 52.72 to - 10.5 dB, while the EM interference shielding effectiveness increases to 13.4 dB, suggesting the coexistence of the two EM functions. Furthermore, based on the high EM absorption, a strain sensor is designed through the resonance coupling of the patterned NiCo2O4 structure. These strategies for tuning EM performance and constructing devices can be extended to other EM functional materials to promote the development of electromagnetic driven devices.

Novel BaTiO3-Based, Ag/Pd-Compatible Lead-Free Relaxors with Superior Energy Storage Performance.

Ceramic dielectrics are reported with superior energy storage performance for applications, such as power electronics in electrical vehicles. A recoverable energy density (Wrec) of ∼4.55 J cm-3 with η ∼ 90% is achieved in lead-free relaxor BaTiO3-0.06Bi2/3(Mg1/3Nb2/3)O3 ceramics at ∼520 kV cm-1. These ceramics may be co-fired with Ag/Pd, which constitutes a major step forward toward their potential use in the fabrication of commercial multilayer ceramic capacitors. Compared to stoichiometric Bi(Mg2/3Nb1/3)O3-doped BaTiO3 (BT), A-site deficient Bi2/3(Mg1/3Nb2/3)O3 reduces the electrical heterogeneity of BT. Bulk conductivity differs from the grain boundary only by 1 order of magnitude which, coupled with a smaller volume fraction of conducting cores due to enhanced diffusion of the dopant via A-site vacancies in the A-site sublattice, results in higher breakdown strength under an electric field. This strategy can be employed to develop new dielectrics with improved energy storage performance.

Real-Time Neural Signals of Disorder and Order Perception.

Order and disorder are prevalent in everyday life, yet little is known about the neural real-time processing that occurs during the perception of disorder relative to order. In the present study, from a cognitive perspective, by adopting the ERP method, we aimed to examine the elicited real-time neural signals of disorder and order perception when participants processed physical environmental and basic visual disorder and order pictures in an irrelevant red or green rectangle detection task, and we attempted to test the hypothesis of cognitive disfluency in disorder perception. Generally, we observed that at each measured time interval, the ERPs elicited by order stimuli were more positive (less negative) in amplitude than those elicited by disorder stimuli at the frontal electrodes (represented by F7/F8, FT7/FT8, Fz, and FCz), whereas at the posterior electrodes (represented by P7/P8, PO7/PO8, Pz, and POz), the opposite was true. These data reveal for the first time the neural underpinnings of disorder and order perception, extending our understanding of the nature of disorder and order. This study also contributes to the cognitive fluency literature and indirectly expands the research on disorder and order stimuli in cognitive fluency.

A smartphone-assisted pressure-measuring-based diagnosis system for acute myocardial infarction diagnosis.

BACKGROUND: Acute myocardial infarction (AMI), usually caused by atherosclerosis of coronary artery, is the most severe manifestation of coronary artery disease which results in a large amount of death annually. A new diagnosis approach with high accuracy, reliability and low measuring-time-consuming is essential for AMI quick diagnosis. PURPOSE: The objective of this study was to develop a new point-of-care testing system with high accuracy and reliability for AMI quick diagnosis. PATIENTS AND METHODS: 50 plasma samples of acute myocardial infarction patients were analyzed by developed Smartphone-Assisted Pressure-Measuring-Based Diagnosis System (SPDS). The concentration of substrate was firstly optimized. The effect of antibody labeling and matrix solution on measuring result were then evaluated. And standard curves for cTnI, CK-MB and Myo were built for clinical sample analysis. The measuring results of 50 clinical samples were finally evaluated by comparing with the measuring result obtained by CLIA. RESULTS: The concentration of substrate H2O2 was firstly optimized as 30% to increase measuring signal. A commercial serum matrix was chosen as the matrix solution to dilute biomarkers for standard curve building to minimize matrix effect on the accuracy of clinical plasma sample measuring. The standard curves for cTnI, CK-MB and Myo were built, with measuring dynamic range of 0-25 ng/mL, 0-33 ng/mL and 0-250 ng/mL, and limit of detection of 0.014 ng/mL, 0.16 ng/mL and 0.85 ng/mL respectively. The measuring results obtained by the developed system of 50 clinical plasma samples for three biomarkers matched well with the results obtained by chemiluminescent immunoassay. CONCLUSION: Due to its small device size, high sensitivity and accuracy, SPDS showed a bright potential for point-of-care testing (POCT) applications.

The Disentangled Sub-Processes Involved in Implied Motion Contributing to Food Freshness: The Neural Evidence from ERPs.

Implied motion can enhance the consumer's judgment of food freshness. However, this enhancing effect has only been investigated for a few products. Furthermore, researchers have not conclusively determined whether the effects of the low-level visual sensory processing and high-level conceptual processing on food evaluation differ. In Experiment 1, using different fruits in static water (fruit_IS), fruit with implied moving water (fruit_IM), or only fruits as stimuli, we initially generalized the effect of implied motion on the broader category of fruit, and implied motion improved the perceived freshness of the fruit. In Experiment 2, we recorded event-related potentials (ERPs) and measured the temporal processes involved in the mechanism by which implied motion improved perceived fruit freshness. The behavioral results further supported the findings from Experiment 1. The ERP data revealed a pronounced positive difference between fruit_IM and fruit-only conditions recorded from posterior electrodes at approximately 200-300 ms (P2). This difference reflected the low-level visual implied motion sensory processing involved in the effect of implied motion on improving food freshness. Additionally, an early frontocentral negativity difference of approximately 300-500 ms between fruit_IM and fruit-only conditions was recorded, which reflected the high-level visual conceptual processing involved in the effect of implied motion on improving food freshness. These results strengthen and extend previous behavioral findings indicating that implied motion enhances the consumer's judgment of food freshness across various food categories, and improves our understanding of the cognitive processes involved in the mechanism by which implied motion influences food judgments.

Fabrication of ultra-small monolayer graphene quantum dots by pyrolysis of trisodium citrate for fluorescent cell imaging.

BACKGROUND: The preparation and biological applications of ultra-small graphene quantum dots (GQDs) with accurate-controlled size are of great significance. METHODS: Here in, we report a novel procedure involving pyrolysis of trisodium citrate and subsequent ultrafiltration for fabricating monolayer GQDs with ultra-small lateral size (1.3±0.5 nm). RESULTS: The GQDs exhibit blue photoluminescence with peak position independent of excitation wavelength. The quantum yield of GQDs is measured to be 3.6%, and the average fluorescence lifetime is 2.78 ns. CONCLUSION: Because of high stability and low toxicity, GQDs are demonstrated to be excellent bioimaging agents. The ultra-small GQDs can not only distribute in the cytoplasm but also penetrate into the nuclei. We ensure that this work will add a new dimension to the application of graphene materials for nanomedicine.

Taurine enhances the protective effect of Dexmedetomidine on sepsis-induced acute lung injury via balancing the immunological system.

Sepsis, an overwhelming systemic inflammatory disease, is the leading cause of acute lung injury (ALI). Despite plenty of researches have been done, effective drugs treating septic ALI are still eagerly needed in the clinic. Dexmedetomidine (Dex), a potent alpha-2 adrenoreceptor agonist, has been reported to possess antioxidant, anti-apoptosis and anti-inflammatory abilities. Taurine, a kind of intracellular free amino acid, has been used to treat various diseases. This study aimed to explore the combination effect of Dex and Taurine on septic ALI and the underlying mechanism in vivo. The establishment of septic ALI was set up in SD rats by cecal ligation and puncture (CLP) operation. Results indicated that Dex or Taurine could reduce septic ALI-induced cell apoptosis via decreasing caspase-3 activity. However, the combination of Dex or Taurine produced greater effect. Besides that, Dex combined with Taurine could better promote cell proliferation with remarkably elevated Ki67 expression. The combination of Dex and Taurine significantly suppressed the activation of NF-κB pathway via inhibiting P65 phosphorylation and P65 nuclear translocation, leading to the down-regulation of interleukin (IL)-6 and IL-1ß. Moreover, co-administration of Dex and Taurine alleviated the imbalance of Th1/Th2 induced by septic ALI to a great extent. All in all, our study suggested the synergistic therapeutic effect of Dex and Taurine on septic ALI.

Prevalence of Suicidal Ideation and Its Association with Positive Affect in Working Women: A Day Reconstruction Study.

The suicide rate for females in China is the second highest worldwide, and China is the only country in the world in which the rate of suicides is higher for women than men. Affective instability has been shown to be a strong predictor of suicidal ideation, particularly among women. However, prior research has mainly focused on the impact of women's negative affect on suicidal ideation, ignoring the influence of positive affect on suicidal ideation. Studies have revealed that hopelessness, which is 1.3 times more important than depression for explaining suicidal ideation, is driven more by low levels of positive affect than by high levels of negative affect. Although positive affect has also been found to be related to suicidal ideation, and it demonstrates independent, beneficial effects on mental health, much remains to be learned about the association between positive affective instability and suicidal ideation. Therefore, we investigated the prevalence of suicidal ideation among Chinese working women and explored the differences between working women with and without suicidal ideation in the intensity and daily variability of positive affect. A total of 222 young working women of ages 22-36 years (M = 27.64, SD = 3.73) were recruited from a free weekend psychology lecture. The women subsequently completed a daily diary Day Reconstruction Method (DRM) as well as a suicidal ideation questionnaire. We used hierarchical linear modeling (HLM) to analyze the data, and the results showed that: (1) 10.81% of participates reported suicidal ideation, the intensity of positive affect (happiness, warmth/friendliness, interest and relaxation/calmness) was significantly lower for women with suicidal ideation compared to women without suicidal ideation; (2) differing diurnal patterns of positive emotions were observed between women with and without suicidal ideation; women with suicidal ideation demonstrated a significantly lower trend of growth and a higher volatility in happiness, warmth/friendliness, relaxation/calmness. Given that lower intensity of positive affect and greater affective instability significantly predicted suicidal ideation in Chinese women, researchers should pay more attention to the role of positive affect in female suicide prevention research and intervention efforts in the future.

Structural Characterization and Functional Analysis of the Follistatin Promoter of Larimichthys crocea.

Follistatin is a secreted glycoprotein, which involved in numerous physiological activities as an antagonist of the transforming growth factor-ß superfamily. However, little is known about the regulation mechanism of follistatin in fish. In this study we cloned and analyzed part of the 5' flanking region of the follistatin gene in Larimichthys crocea. Sequence analysis revealed several putative binding sites for transcription factors including activator protein 1 (AP1), myogenic differentiation factor (MyoD), stimulating protein 1 (SP1), and sex determining gene on the mammalian Y chromosome (SRY) in the cloned fragment. Transcriptional activities of two fragments (485 and 261 bp) truncated from follistatin upstream region were examined in vitro, using transient transfection in Ctenopharyngodon idella kidney (CIK) and Rattus norvegicus skeletal muscle myoblast (L6) cells. The result showed that the promoter activity correlated positively with the length of truncated fragments in both CIK and L6 cells. To study the regulation of follistatin expression in L. crocea, we cloned MyoD and SRY-box 8 (Sox8) genes and examined their action on the follistatin promoter by co-transfection in CIK and L6 cells. The results showed MyoD and Sox8 could suppress the activities of follistatin promoter at different levels in CIK and L6 cells.

Suppression of phosphatase and tensin homolog protects insulin-resistant cells from apoptosis.

In the present study, a glucosamine-induced model of insulin-resistant skeletal muscle cells was established in order to investigate the effect of inhibition of phosphatase and tensin homolog (PTEN)/5'-adenosine monophosphate-activated protein kinase (AMPK) on these cells. The glucosamine-induced insulin-resistant skeletal muscle cells were produced and the rate of glucose uptake was measured using the glucose oxidase-peroxidase method. The expression levels of PTEN and phosphorylated PTEN (p-PTEN) were assessed using western blotting. Glucose transporter 4 (GLUT4) translocation was detected by immunofluorescence. Cell apoptosis was evaluated using flow cytometry. Following insulin stimulation, the rate of glucose uptake was significantly reduced in the cells with glucosamine-induced insulin-resistance in comparison with those in the control group. The expression and translocation of GLUT4 were reduced in the insulin-resistant muscle cells. By contrast, the expression of PTEN and p-PTEN as well as apoptosis were significantly increased. Following treatment with bisperoxopicolinatooxovanadate (BPV) or metformin in the insulin-resistant skeletal muscle cells, there was an increase in the rate of glucose uptake, an increase in GLUT4 expression and its translocation, a reduction in the expression of PTEN and p-PTEN, and a decrease in cell apoptosis compared with untreated insulin-resistant cells. Glucosamine may be used to produce an effective model of insulin-resistant skeletal muscle cells. Cells with glucosamine-induced insulin-resistance exhibited a reduced expression of GLUT4 and dysfunction in GLUT4 translocation, as well as increased activation of PTEN and increased cell apoptosis. Inhibition of PTEN or its upstream regulator, AMPK, protects glucosamine-induced insulin-resistant skeletal muscle cells from apoptosis.