PAX3-FOXO1 coordinates enhancer architecture, eRNA transcription, and RNA polymerase pause release at select gene targets.

Transcriptional control is a highly dynamic process that changes rapidly in response to various cellular and extracellular cues, making it difficult to define the mechanism of transcription factor function using slow genetic methods. We used a chemical-genetic approach to rapidly degrade a canonical transcriptional activator, PAX3-FOXO1, to define the mechanism by which it regulates gene expression programs. By coupling rapid protein degradation with the analysis of nascent transcription over short time courses and integrating CUT&RUN, ATAC-seq, and eRNA analysis with deep proteomic analysis, we defined PAX3-FOXO1 function at a small network of direct transcriptional targets. PAX3-FOXO1 degradation impaired RNA polymerase pause release and transcription elongation at most regulated gene targets. Moreover, the activity of PAX3-FOXO1 at enhancers controlling this core network was surprisingly selective, affecting single elements in super-enhancers. This combinatorial analysis indicated that PAX3-FOXO1 was continuously required to maintain chromatin accessibility and enhancer architecture at regulated enhancers.

Transcriptome analysis reveals that PbMYB61 and PbMYB308 are involved in the regulation of lignin biosynthesis in pear fruit stone cells.

Pear fruit stone cells have thick walls and are formed by the secondary deposition of lignin in the primary cell wall of thin-walled cells. Their content and size seriously affect fruit characteristics related to edibility. To reveal the regulatory mechanism underlying stone cell formation during pear fruit development and to identify hub genes, we examined the stone cell and lignin contents of 30 'Shannongsu' pear flesh samples and analyzed the transcriptomes of 15 pear flesh samples collected at five developmental stages. On the basis of the RNA-seq data, 35 874 differentially expressed genes were detected. Additionally, two stone cell-related modules were identified according to a WGCNA. A total of 42 lignin-related structural genes were subsequently obtained. Furthermore, nine hub structural genes were identified in the lignin regulatory network. We also identified PbMYB61 and PbMYB308 as candidate transcriptional regulators of stone cell formation after analyzing co-expression networks and phylogenetic relationships. Finally, we experimentally validated and characterized the candidate transcription factors and revealed that PbMYB61 regulates stone cell lignin formation by binding to the AC element in the PbLAC1 promoter to upregulate expression. However, PbMYB308 negatively regulates stone cell lignin synthesis by binding to PbMYB61 to form a dimer that cannot activate PbLAC1 expression. In this study, we explored the lignin synthesis-related functions of MYB family members. The results presented herein are useful for elucidating the complex mechanisms underlying lignin biosynthesis during pear fruit stone cell development.

Boosting the sonodynamic performance of CoBiMn-layered double hydroxide nanoparticles via tumor microenvironment regulation for ultrasound imaging-guided sonodynamic therapy.

Sonodynamic therapy (SDT), a promising strategy for cancer treatment with the ability for deep tissue penetration, has received widespread attention in recent years. Sonosensitizers with intrinsic characteristics for tumor-specific curative effects, tumor microenvironment (TME) regulation and tumor diagnosis are in high demand. Herein, amorphous CoBiMn-layered double hydroxide (a-CoBiMn-LDH) nanoparticles are presented as multifunctional sonosensitizers to trigger reactive oxygen species (ROS) generation for ultrasound (US) imaging-guided SDT. Hydrothermal-synthesized CoBiMn-LDH nanoparticles are etched via a simple acid treatment to obtain a-CoBiMn-LDH nanoparticles with abundant defects. The a-CoBiMn-LDH nanoparticles give greater ROS generation upon US irradiation, reaching levels ~ 3.3 times and ~ 8.2 times those of the crystalline CoBiMn-LDH nanoparticles and commercial TiO2 sonosensitizer, respectively. This excellent US-triggered ROS generation performance can be attributed to the defect-induced narrow band gap and promoted electrons and holes (e-/h+) separation. More importantly, the presence of Mn4+ enables the a-CoBiMn-LDH nanoparticles to regulate the TME by decomposing H2O2 into O2 for hypoxia relief and US imaging, and consuming glutathione (GSH) for protection against ROS clearance. Biological mechanism analysis shows that a-CoBiMn-LDH nanoparticles modified with polyethylene glycol can serve as a multifunctional sonosensitizer to effectively kill cancer cells in vitro and eliminate tumors in vivo under US irradiation by activating p53, apoptosis, and oxidative phosphorylation-related signaling pathways.

Satellite glial cell-secreted exosomes after in-vitro oxaliplatin treatment presents a pro-nociceptive effect for dorsal root ganglion neurons and induce mechanical hypersensitivity in naïve mice.

BACKGROUND: The pathophysiological mechanism underlying chemotherapy-induced neuropathic pain (CINP) remains unclear. Sensory neuronal hypersensitivity in the dorsal root ganglion (DRG) is essential for the onset and maintenance of chronic pain. Satellite glial cells (SGCs) in the DRG potentially affect the function of sensory neurons, possibly by mediating extracellular or paracrine signaling. Exosomes play an essential role in cell-cell communication. However, the role of SGC-secreted exosomes in glia-neuron communication and CINP remains unclear. METHODS: SGCs and sensory neurons were cultured from the DRG of mice. The SGCs were treated with 4 µM oxaliplatin for 24 h. Glial fibrillary acid protein (GFAP) and connexin-43 (Cx-43) expressions in the SGCs were examined with immunocytochemistry (ICC). Enzyme-linked immunosorbent assay (ELISA) detected cytokine release in the SGCs after oxaliplatin treatment. Subsequently, SGC-secreted exosomes were collected using ultracentrifugation and identified by nanoparticle tracking analysis, transmission electron microscopy, and western blotting. Subsequently, DRG neurons were incubated with SGC-secreted exosomes for 24 h. The percentage of reactive oxygen species (ROS)-positive neurons was detected using flow cytometry, and acid-sensing ion channel 3 (ASIC3) and transient receptor potential vanilloid 1 (TRPV1) expression were examined by western blotting. SGC-secreted exosomes were intrathecally injected into naïve mice. The mechanical withdrawal threshold was assessed 24, 48, and 72 h following the injection. TRPV1 expression in the DRG was examined 72 h after intrathecal injection. Furthermore, differentially expressed (DE) miRNAs within the SGC-secreted exosomes were detected using RNA sequencing and bioinformatics analysis. Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway analyses were performed to predict the function of the target genes of DE miRNAs. Finally, the DE miRNAs with pain regulation potential were identified in silico. RESULTS: After in-vitro oxaliplatin treatment, ICC showed an increase in the immunoreactivity of GFAP and Cx-43 in the SGCs. ELISA results suggested an increased release of tumor necrosis factor-α and interleukin (IL)-1ß, but a decreased release of IL-10. Oxaliplatin treatment increased the secretion of exosomes in the SGCs from 4.34 to 5.99 × 1011 (particles/ml). The exosome-specific markers CD9 and TSG101 were positive, whereas calnexin was negative for the obtained exosomes. Additionally, the SGC-secreted exosomes were endocytosed by DRG neurons after co-incubation. Moreover, after incubation with conditioned SGC-secreted exosomes (after 4 µM oxaliplatin treatment), the percentage of ROS-positive DRG neurons increased and ASIC3 and TRPV1 expressions were upregulated. After the intrathecal injection of the conditioned SGC-secreted exosomes, the mice presented with mechanical hypersensitivity and TRPV1 expression upregulation in the DRG. Notably, 25 and 120 significantly upregulated and downregulated miRNAs, respectively, were identified in the conditioned SGC-secreted exosomes. When predicting the function of target genes of DE miRNAs, certain GO terms, such as synapse organization, neurogenesis regulation, histone modification, and pain-related KEGG or Reactome pathways, including vascular endothelial growth factor A-vascular endothelial growth factor receptor 2, mammalian target of rapamycin, and mitogen-activated protein kinase signaling pathways, related to nervous system function were predicted. Finally, 27 pain regulation-related miRNAs, including miR-324-3p, miR-181a-5p, and miR-122-5p, were identified in silico. CONCLUSION: Our study demonstrates that SGC-secreted exosomes after in-vitro oxaliplatin treatment present a pro-nociceptive effect for DRG neurons and induce mechanical hypersensitivity in naïve mice, possibly via the contained miRNA cargo. Identifying the candidate miRNAs and verifying their functions in vivo are required to elucidate the exosomes mediating 'glia-neuron' communication under CINP condition.

Assessment Methods and Intervention Strategies for Cleft-Related Lateral Misarticulation in Chinese-Speaking Children.

The aim of this study was to analyze the characteristics and error speech features of cleft-related lateral misarticulation and provide a basis for clinical evaluation and rational intervention. Participants who were diagnosed with lateral misarticulation after cleft palate repairment were 126 children aged 4, 6 to 16, and 11, and they had complete palatopharyngeal closure, no abnormalities in their speech organs and occlusion, and no hearing or intellectual impairments. The Chinese standard pronunciation clarity word list, the American KAY CSL4500, the Beijing Yangchen YF-16 computer speech analysis workstation, soundproof rooms, Wechsler scales of intelligence-fourth edition, and audiometers were used to evaluate the cleft-related lateral misarticulation. Statistical analysis was performed on the age, gender, error rate, corner of the mouth deviation direction, comorbidity, duration of intervention, period of treatment, and therapeutic effect of concentrated or normal intervention group in different patients. Our results showed that 2 to 3 straight stripes were visible at the onset of consonants /ti:/ /t'i:/, and 3 clear straight lines were visible in /tʂ/, indicating that the lateralized sound had 2 or 3 bursts and lasted for 1 to 2 ms. The onset age of lateralized sound was mostly below 12 years old. Chinese lateralized sound mainly occurred in vowel /i:/, and the occurrence rate of consonants with tongue surface /tɕ]/ /tɕ'/ /ɕ/ was the highest. In addition, the corner of the mouth deviation was also an indicator of lateralization sound, and other types of speech disorders mostly accompanied it. There was a significant difference in the improvement of speech clarity between the concentrated intervention group and the normal group before and after treatment. The 2 groups' average duration and course of treatment were not significantly different. Still, the period of concentrated intervention was shortened considerably, and the speech clarity of both groups of children after treatment exceeded 96%, reaching a normal level.

A Model-Based Approach to the Disentanglement and Differential Treatment of Engaged and Disengaged Item Omissions.

Item omissions in large-scale assessments may occur for various reasons, ranging from disengagement to not being capable of solving the item and giving up. Current response-time-based classification approaches allow researchers to implement different treatments of item omissions presumably going back to different mechanisms. These approaches, however, are limited in that they require a clear-cut decision on the underlying missingness mechanism and do not allow to take the uncertainty in classification into account. We present a response-time-based model-based mixture modeling approach that overcomes this limitation. The approach (a) facilitates disentangling item omissions stemming from disengagement from those going back to solution behavior, (b) considers the uncertainty in omission classification, (c) allows for omission mechanisms to vary on the item-by-examinee level, (d) supports investigating person and item characteristics associated with different types of omission behavior, and (e) gives researchers flexibility in deciding on how to handle different types of omissions. The approach exhibits good parameter recovery under realistic research conditions. We illustrate the approach on data from the Programme for the International Assessment of Adult Competencies 2012 and compare it against previous classification approaches for item omissions.

Metformin promotes microglial cells to facilitate myelin debris clearance and accelerate nerve repairment after spinal cord injury.

Spinal cord injury (SCI) is one kind of severe trauma for central nervous system. Myelin debris clearance and axon regeneration are essential for nerve regeneration after SCI. Metformin, a glucose-lowering drug, has been demonstrated to promote the locomotor functional recovery after SCI. In this study, we investigated the role and molecular mechanism of metformin on myelin preservation in a rat SCI model. SCI was induced in rats by compression at T9 level using a vascular clip. We showed that administration of metformin (50 mg·kg-1·d-1, ip) for 28 days significantly improved locomotor function in SCI rats. Metformin also ameliorated SCI-induced neuronal apoptosis and promoted axon regeneration in the spinal cord. Using co-immunofluorescence of IBa-1 and MBP, and luxol fasting blue (LFB) staining, we demonstrated that metformin promoted the transformation of M1 to M2 phenotype polarization of microglial cells, then greatly facilitated myelin debris clearance and protected the myelin in SCI rats. Furthermore, metformin ameliorated SCI-induced blockade of autophagic flux in the spinal cord, and enhanced the fusion of autophagosome and lysosome by inhibiting the AMPK-mTOR signaling pathway. Moreover, metformin significantly attenuated inflammatory responses in the spinal cord. In LPS-treated BV2 cells, pretreatment with metformin (2 mM) significantly enhanced autophagy level, suppressed inflammation and cell apoptosis. The protective effects were blocked in the presence of an autophagy inhibitor 3-methyladenine (3-MA, 5 mM), suggesting that the effect of metformin on autophagy in microglial cells is essential for the myelin preservation during nerve recovery. This study reveals a novel therapeutic effect of metformin in SCI recovery by regulating the activation of microglial cells and enhancing its autophagy level.

Diallyl trisulfide reduced the reproductive capacity of male Sitotroga cerealella via the regulation of juvenile and ecdysone hormones.

Environmental pollution and resistance in animals are major concerns for the application of synthetic pesticides. Diallyl trisulfide (DAT), an active compound in garlic essential oil, is a novel tool for active and safe control of agricultural insect pests. In this study, we analysed the effects of DAT (0.01 µL/L) on the protein content in male reproductive tissues (accessory glands, ejaculatory ducts, and testis), and juvenile hormone (JH) and ecdysone titres in a highly detrimental pest of stored products, Sitotroga cerealella. Evaluation of the expression profile of JH and ecdysone pathway-related genes in various tissues indicated that the accessory gland protein and ecdysone titres were markedly decreased after DAT fumigation, whereas the testis protein content and JH titre were increased. However, the protein content of the ejaculatory ducts remained unchanged between the treated and control groups. Further investigation revealed that DAT disrupted the mRNA expression of key enzymes involved in JH and ecdysone pathways. While increased mRNA levels of juvenile hormone acid O-methyltransferase (JHMAT) and Kruppel homologue 1 (Kr-h1) were observed after 4 and 7 h of DAT fumigation, the levels of juvenile hormone epoxide hydrolase (JHEH) were substantially reduced 3 h post-fumigation. mRNA levels of the ecdysone-responsive gene, FTZF1, and cytochrome P450 enzyme, CYP315A1, were notably decreased at 7 h and 4 h, respectively, post-fumigation, whereas CYP314A1 and CYP302A1 mRNA levels decreased after 3 h and 4 h, respectively. While DAT fumigation disrupted sperm number in the testis, ejaculatory ducts, and seminal vesicles, topical application of the 20-hydroxyecdysone (20E) analogue also lowered sperm number in the ejaculatory ducts. Topical application of methoprene, a JH analogue, increased the protein content in the testes, but not in the accessory glands or ejaculatory ducts. However, the survival rate was not affected by the topical application of methoprene or 20E. These data suggest that DAT regulates JH and ecdysone via its molecular pathway genes and modulates endocrine secretion during the male reproductive process.

Diagnosis, treatment and genetic analysis of 11ß -hydroxylase deficiency caused by CYP11B gene mutation.

Congenital adrenal hyperplasia (CAH) is an autosomal recessive hereditary disease, and the 11ß- hydroxylase deficiency is the second most common syndrome in different types of CAH. The occurrence of 11ß- hydroxylase deficiency is related to the mutation of CYP11B gene on human autosome 8. In this report, we detected the gene mutation sites of a 14-year-old patient with 11ß-hydroxylase deficiency by whole exon sequencing (WES), verified the suspected mutation by Sanger sequencing, and analyzed its characteristics. Gene sequencing revealed that homozygous missense mutation of c.1226C>T appeared on the 8th exon of CYP11B1 gene, which resulted in the mutation of the encoding protein Ser409 to phenylalanine (p. Ser409Phe), affecting the binding of heme and enzyme and resulting in the loss of CYP11B1 enzyme activity and a series of clinical symptoms. This mutation has not been reported at home and abroad. This case enriches the variation spectrum of CYP11B1 gene and provides clinical data and genetic resources for further research on the pathogenesis of 11ß-hydroxylase deficiency.

Latent Class Analysis of the CBCL Dysregulation Profile for 6- to 16-Year-Olds in 29 Societies.

Objective: We used latent class analysis (LCA) to examine the prevalence and characteristics of the Dysregulation Profile (DP) based on data from the Child Behavior Checklist for Ages 6-18. The DP comprises elevated scores on the Anxious/Depressed, Attention Problems, and Aggressive Behavior syndromes and thus reflects significant problems in self-regulation of mood, attention, and behavior.Method: We examined CBCL data for 56,666 children ages 6 to 16 in 29 societies, many of which are countries but some of which are not (e.g., Hong Kong, Puerto Rico). The 29 societies varied widely in race/ethnicity, religion, geographic location, political/economic system, and population size.Results: The various statistical indices for good LCA model fit, while not always consistent, supported a DP class in every society. The omnicultural mean probability of assignment to the DP class (mean of the societal means) was 93% (SD = 2.4%). Prevalence of the DP class ranged from 2% to 18% across societies, with an omnicultural mean prevalence of 9%. In every society, the DP class had significantly higher scores than the pooled non-DP classes on all three DP syndromes. The 8-syndrome T score profile for the DP class in many societies featured elevations on all eight CBCL syndromes.Conclusions: Although the same instrument, analytic procedures, and decision rules were used in these 29 samples, model fit, the number of classes, and the prevalence of the DP class varied across societies. High scores on the three DP syndromes often co-occurred with high scores on most other CBCL syndromes.

A joint modeling framework of responses and response times to assess learning outcomes.

A general modeling framework of response accuracy and response times is proposed to track skill acquisition and provide additional diagnostic information on the change of latent speed in a learning environment. This framework consists of two types of models: a dynamic response model that captures the response accuracy and the change of discrete latent attribute profile upon factors such as practice, intervention effects, and other latent and observable covariates, and a dynamic response time model that describes the change of the continuous response latency due to change of latent attribute profile. These two types of models are connected through a parameter, describing the change rate of the latent speed through the learning process, and a covariate defined as a function of the latent attribute profile. A Bayesian estimation procedure is developed to calibrate the model parameters and measure the latent variables. The estimation algorithm is evaluated through several simulation studies under various conditions. The proposed models are applied to a real data set collected through a spatial rotation diagnostic assessment paired with learning tools.

A multilevel logistic hidden Markov model for learning under cognitive diagnosis.

Students who wish to learn a specific skill have increasing access to a growing number of online courses and open-source educational repositories of instructional tools, including videos, slides, and exercises. Navigating these tools is time-consuming and the search itself can hinder the learning of the skill. Educators are hence interested in aiding students by selecting the optimal content sequence for individual learners, specifically which skill one should learn next and which material one should use to study. Such adaptive selection would rely on pre-knowledge of how the learners' and the instructional tools' characteristics jointly affect the probability of acquiring a certain skill. Building upon previous research on Latent Transition Analysis and Learning Trajectories, we propose a multilevel logistic hidden Markov model for learning based on cognitive diagnosis models, where the probability that a learner acquires the target skill depends not only on the general difficulty of the skill and the learner's mastery of other skills in the curriculum but also on the effectiveness of the particular learning tool and its interaction with mastery of other skills, captured by random slopes and intercepts for each learning tool. A Bayesian modeling framework and an MCMC algorithm for parameter estimation are proposed and evaluated using a simulation study.

BET inhibitors reduce cell size and induce reversible cell cycle arrest in AML.

Inhibitors of the bromodomain and extraterminal domain family (BETi) offer a new approach to treat hematological malignancies, with leukemias containing mixed lineage leukemia rearrangements being especially sensitive due to a reliance on the regulation of transcription elongation. We explored the mechanism of action of BETi in cells expressing the t(8;21), and show that these compounds reduced the size of acute myeloid leukemia cells, triggered a rapid but reversible G0 /G1 arrest, and with time, cause cell death. Meta-analysis of PRO-seq data identified ribosomal genes, which are regulated by MYC, were downregulated within 3 hours of addition of the BETi. This reduction of MYC regulated metabolic genes coincided with the loss of mitochondrial respiration and large reductions in the glycolytic rate. In addition, gene expression analysis showed that transcription of BCL2 was rapidly affected by BETi but this did not cause dramatic increases in cell death. Cell cycle arrest, lowered metabolic activity, and reduced BCL2 levels suggested that a second compound was needed to push these cells over the apoptotic threshold. Indeed, low doses of the BCL2 inhibitor, venetoclax, in combination with the BETi was a potent combination in t(8;21) containing cells. Thus, BET inhibitors that affect MYC and BCL2 expression should be considered for combination therapy with venetoclax.

Multi-code magnetic beads based on DNAzyme-mediated double-cycling amplification for a point-of-care assay of telomerase activity.

Development of a reliable and facile telomerase activity assay with high specificity and sensitivity is a central challenge to make telomerase testing a routine part of medical care with respect to cancer. Herein, we propose a point-of-care (POC) assay of telomerase activity based on multi-code magnetic beads initiated by DNAzyme-mediated double-cycling amplification coupling with a glucometer. A designed DNAzyme-based telomerase substrate prime (DTSP) probe consists of three regions (AXB) for a DNAzyme catalytic sequence, poly-thymine (poly-T) linker and telomere primer sequence. In the presence of telomerase, telomerase elongates the primer site on the DTSP probe. Subsequent addition of the PbII cofactor activates the DNAzyme, which cleaves the elongated fragment at the RNA site, and releases the DTSP probe for repetitive cycling and the elongated fragment. The cleaved fragment as a trigger then continuously triggers the cyclic strand displacement reaction (CSDR) between MB-H1 and invertase-H2, constructing the second cycling and forming the MB-H1/invertase-H2 duplex. Owing to the double-cycling amplification, numerous invertases were coded onto the surface of MBs. After magnetic separation, the enriched multi-code MB catalytically hydrolyzes the sucrose substrate with multiple turnovers, generating a large amount of glucose for quantitative readout by personal glucose meters (PGM). Benefiting from the double-cycling amplification and magnetic separation, a high signal-to-background ratio was achieved, and the point-of-care assay realizes sensitive telomerase activity detection down to 5 HeLa cells with a significantly enhanced dynamic range without the need for enzymatic amplification. The designed DTSP probe highly ensured the specificity and reliability due to the high dependence of DNAzyme on the metal ion cofactor. Moreover, this method can be applied for the screening of telomerase inhibitors and the discrimination of cancer cells from normal cells. With the ability of simple operation, outstanding sensitivity, and excellent selectivity, this method offers a convenient and specific POCT strategy for telomerase activity detection, holding great potential in clinical diagnosis and drug discovery.

Effects of TACE and preventive antiviral therapy on HBV reactivation and subsequent hepatitis in hepatocellular carcinoma: a meta-analysis.

BACKGROUND AND AIM: The impact of transarterial chemoembolization (TACE) and preventive antiviral therapy on the occurrence of hepatitis B virus (HBV) reactivation and subsequent hepatitis remains controversial. This meta-analysis aimed to evaluate the effect of TACE and preventive antiviral therapy on the risk of HBV reactivation and subsequent hepatitis. Meanwhile, we explored the role of HBeAg status in HBV reactivation after TACE. METHODS: We performed this meta-analysis with 11 included studies to assess the effect of TACE and preventive antiviral therapy on predicting clinical outcomes in HBV-related hepatocellular carcinoma (HCC). The pooled odds ratios (OR) were calculated using a random or fixed effects model. PUBMED, MEDLINE, EMBASE and the Cochrane Central Register of Controlled were searched for the included articles (from 2000 to December 2017). RESULTS: Our results showed that TACE significantly increased the risk of HBV reactivation (OR: 3.70; 95% CI 1.45-9.42; P < 0.01) and subsequent hepatitis (OR: 4.30; 95% CI 2.28-8.13; P < 0.01) in HCC patients. There was no significant difference in HBV reactivation after TACE between HBeAg positive and negative patients (OR: 1.28; 95% CI 0.31-5.34; P = 0.73). Preventive antiviral therapy could statistically reduce the rate of HBV reactivation (OR: 0.08; 95% CI 0.02-0.32; P < 0.01) and hepatitis (OR: 0.22; 95% CI 0.06-0.80; P = 0.02) in those with TACE treatment. CONCLUSIONS: The present study suggested that TACE was associated with a higher possibility of HBV reactivation and subsequent hepatitis. Preventive antiviral therapy is significantly in favor of a protective effect.

Functional Analysis of the Minimal Twin-Arginine Translocation System Components from Streptococcus thermophilus CGMCC 7.179 in Escherichia coli DE3.

The twin-arginine translocation (Tat) system, which is used for folded protein secretion, is rare in lactic acid bacteria (LAB). Previously, a Tat system composed of TatAS and TatCS subunits (the subscript S denotes a Streptococcus thermophilus origin) was identified in S. thermophilus CGMCC 7.179. In the present study, the tatA S and tatC S genes were cloned and functionally analyzed in Escherichia coli DE3 tat-deficient mutants. The E. coli tatABCDE-deficient mutant complemented with tatC S A S exhibited shortened cellular chains, but its ability to grow in the presence of sodium dodecyl sulfate (SDS) was not restored, suggesting that the S. thermophilus Tat system could partially replace that of E. coli. Surprisingly, the E. coli tatABE-deficient mutant complemented with tatA S and the E. coli tatC-deficient mutant complemented with tatC S displayed relatively normal cellular morphology and enhanced tolerance to SDS. These results suggest that TatAS and TatCS could serve as active protein translocases in E. coli DE3 tat-deficient mutants. Moreover, TatAS acted as a bifunctional subunit to fulfill the roles of both TatA and TatB of E. coli DE3. Thus, this minimal Tat system would be a promising candidate to translocate recombinant proteins in LAB.

Lithium Ameliorates LPS-Induced Astrocytes Activation Partly via Inhibition of Toll-Like Receptor 4 Expression.

BACKGROUND/AIMS: Astrocytes are critical for the development of postoperative cognitive dysfunction (POCD). In addition, astrocytes express toll-like receptors 4 (TLR4) and build up responses to innate immune triggers by releasing pro-inflammatory molecules. The pathogenesis of neurological disorders often involves the activation of astrocytes and associated inflammatory processes. Lithium, a primary drug for the treatment of bipolar disorder, has recently been suggested to have a role in neuroprotection during neurodegenerative diseases. In this study, we aimed to investigate whether lithium can ameliorate LPS-induced astrocytes activation via inhibition of TLR4 expression. METHODS: Primary astrocytes cells were pretreated with lithium and stimulated with lipopolysaccharide (LPS). Cellular activation, cytokine production, and TLR4 expression, were assessed. RESULTS: Lithium significantly inhibited LPS-induced astrocytes activation and pro-inflammatory cytokine production, as well as LPS-induced TLR4 expression. CONCLUSIONS: Lithium can inhibit LPS-induced TLR4 expression and astrocytes activation. These results indicate that lithium plays an important role in astrocytes activation and neuroinflammation-related diseases, which may open new avenues for neuroscience and biomedical research, and also offers new insight into the treatment of POCD.

Activated brain mast cells contribute to postoperative cognitive dysfunction by evoking microglia activation and neuronal apoptosis.

BACKGROUND: Neuroinflammation plays a key role in the occurrence and development of postoperative cognitive dysfunction (POCD). Microglia, the resident immune cells in the brain, has been increasingly recognized to contribute to neuroinflammation. Although brain mast cells (MCs) are the "first responder" in the brain injury rather than microglia, little is known about the functional aspects of MCs-microglia interactions. METHODS: Male Sprague-Dawley (SD) rats were injected intracerebroventricular with MC stabilizer Cromolyn (100 µg/µl), MC stimulator C48/80 (1 µg/µl), or sterile saline 30 min before open tibial fracture surgery, and the levels of neuroinflammation and memory dysfunction were tested 1 and 3 days after surgery. In addition, the effect of activated MCs on microglia and neurons was determined in vitro. RESULTS: Tibial fracture surgery induced MCs degranulation, microglia activation, and inflammatory factors production, which initiated the acute brain inflammatory response and neuronal death and exhibited cognitive deficit. Site-directed preinjection of the "MCs stabilizer" disodium cromoglycate (Cromolyn) inhibited this effect, including decrease of inflammatory cytokines, reduced MCs degranulation, microglia activation, neuronal death, and improved cognitive function 24 h after the surgery. In vitro study, we found that the conditioned medium from lipopolysaccharide (LPS)-stimulated mast cells line (P815) could induce primary microglia activation through mitogen-activated protein kinase (MAPK) pathway signaling and subsequent production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). In addition, the activated P815 could directly induce neuronal apoptosis and synapse injury with microglia independently. Cromolyn could inhibit P815 activation following improved microglia activation and neuronal loss. CONCLUSIONS: These results implicate that activated MCs could trigger microglia activation and neuronal damage, resulting in central nervous system (CNS) inflammation, and communications of MCs with microglia and neuron could constitute a new and unique therapeutic target for CNS immune inflammation-related diseases.

Enhancement of LPS-induced microglial inflammation response via TLR4 under high glucose conditions.

BACKGROUND: Microglia activation mediated by toll-like receptor 4 (TLR4) plays an important role in neuroinflammation and postoperative cognitive dysfunction (POCD). Diabetes mellitus (DM) has been recently suggested as an independent risk factor for POCD. In this study, we investigate the potential exacerbation of the inflammatory response in primary microglia due to high glucose conditions. METHODS: Primary microglial cells were exposed to normal glucose (25 mmol/L) and high glucose (35 mmol/L) levels alone or with lipopolyscaccharide (LPS 0, 2, 5, 10 ng/mL). The pro-inflammatory response of the cells was assessed by measuring changes in cytokine levels and the evaluation of associated signaling pathways. RESULTS: Neither high glucose nor low LPS (≤5 ng/ml) alone had an effect on TNF-a and IL-6 levels, but the combination of low LPS and high glucose stimulated the inflammatory response. Analyses of the associated signaling pathways demonstrated that high glucose enhanced the LPS-induced microglial activation via the TLR4/JAK2/STAT3 pathway. CONCLUSION: This study demonstrates that high glucose, one of the key abnormalities characteristic of DM, can augment LPS-induced microglial activation and inflammatory cytokine levels through the TLR4/JAK2/STAT3 pathway, offering new insight into the pathophysiological relationship between DM and POCD.

IL-17A is implicated in lipopolysaccharide-induced neuroinflammation and cognitive impairment in aged rats via microglial activation.

BACKGROUND: Neuroinflammation is considered a risk factor for impairments in neuronal function and cognition that arise with trauma, infection, and/or disease. IL-17A has been determined to be involved in neurodegenerative diseases such as multiple sclerosis. Recently, IL-17A has been shown to be upregulated in lipopolysaccharide(LPS)-induced systemic inflammation. This study aims to explore the role of IL-17A in LPS-induced neuroinflammation and cognitive impairment. METHODS: Male Sprague-Dawley (SD) rats were injected intraperitoneally with LPS (500 µg/kg), and IL-17A expression in serum and in the hippocampus was examined 6, 12, 24, and 48 h later. Then, we investigated whether IL-17A-neutralizing antibodies (IL-17A Abs, 1 mg/kg) prevented neuroinflammation and memory dysfunction in aged rats that received LPS (500 µg/kg) injection. In addition, the effect of IL-17A on microglial activation in vitro was determined using ELISA and immunofluorescence. RESULTS: LPS injection increased the expression of IL-17A in serum and in the hippocampus. IL-17A Abs improved LPS-induced memory impairment. In addition, IL-17A Abs prevented the LPS-induced expression of TNF-α, IL-6 and inflammatory proteins, and of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as the activation of microglia in the brain. IL-17A Abs also inhibited the expression of amyloid precursor protein (APP) and BACE1 and increased the expression of the synaptic marker PSD95 in the aged rats treated with LPS. In an in vitro study, we found that recombinant IL-17A could simulate microglial activation and increase production of pro-inflammatory cytokines. CONCLUSION: Taken together, our results suggest that IL-17A was involved in LPS-induced neuroinflammation and cognitive impairment in aged rats via microglial activation. Anti-IL-17A may represent a new therapeutic strategy for the treatment of endotoxemia-induced neuroinflammation and cognitive dysfunction.