Furofuran Lignans for Plant Protection: Discovery of Sesamolin and Its Derivatives as Novel Anti-Tobacco Mosaic Virus and Antibacterial Agents.

Natural products have been a valuable source of efficient and low-risk pesticides. In this work, a series of novel sesamolin derivatives A0-A31 and B0-B4 were designed and synthesized via structural simplification of furofuran lignan phrymarolin II, and their antiviral and antibacterial activities were systematically evaluated. The bioassay results showed that compound A24 displayed remarkable inactivation activity against tobacco mosaic virus (TMV) with an EC50 value of 130.4 µg/mL, which was superior to that of commercial ningnanmycin (EC50 = 202.0 µg/mL). The antiviral mode of action assays suggested that compound A24 may obstruct self-assembly by binding to TMV coat protein (CP), thus resisting the TMV infection. In addition, compound A25 possessed prominent antibacterial activities, especially against Ralstonia solanacearum with an EC50 value of 43.8 µg/mL, which is better than those of commercial bismerthiazol and thiodiazole copper. This research lays a solid foundation for the utilization of furofuran lignans in crop protection.

Biotransformation and bioaccessibility of active ingredients from Radix Astragali by Poria cocos during solid-state fermentation and in vitro digestion and antioxidant activity evaluation.

Radix Astragali is one of the most famous and frequently used health food supplements and herbal medicines. Among more than 227 components of Radix Astragali, Astragaloside IV (AG IV) is famous functional compound and is commonly used as a quality marker for Radix Astragali. However, the relatively low content of AG IV in Radix Astragali (< 0.04%, w/w) severely limits its application. The purpose of this study is to improve the biotransformation of AG IV and its bioaccessibility during in vitro digestion by Poria cocos solid fermenting Radix Astragali. The optimum fermentation conditions were as follows: Inoculation amount 8 mL; fermentation time 10 d; fermentation humidity 90%. Through fermentation, the content of AG IV was increased from 384.73 to 1986.49 µg/g by 5.16-fold. After in vitro digestion, the contents of genistin, calycosin, formononetin, AG IV, Astragaloside II (AG II) and total flavonoids in fermented Radix Astragali (FRA) of enteric phase II (ENTII) were 34.52 µg/g, 207.32 µg/g, 56.76 µg/g, 2331.46 µg/g, 788.31 µg/g, 3.37 mg/g, which were 2.08-fold, 2.51-fold, 1.05-fold, 8.62-fold, 3.22-fold and 1.50-fold higher than those of control, respectively. The Scanning electron microscopy (SEM) of FRA showed rough surface and porous structure. The DPPH and ABTS radical scavenging rate of FRA were higher than those of control. These results showed that the Poria cocos solid fermentation could increase the content of the AG IV in Radix Astragali and improve the bioaccessibility and antioxidant activity of Radix Astragali, which is providing new ideas for future development and utilization of Radix Astragali.

Gastrointestinal dysfunction is associated with mortality in severe burn patients: a 10-year retrospective observational study from South China.

BACKGROUND: Data on severe and extensive burns in China are limited, as is data on the prevalence of a range of related gastrointestinal (GI) disorders [such as stress ulcers, delayed defecation, opioid-related bowel immotility, and abdominal compartment syndrome (ACS)]. We present a multicentre analysis of coincident GI dysfunction and its effect on burn-related mortality. METHODS: This retrospective analysis was conducted on patients with severe [≥ 20% total burn surface area (TBSA)] and extensive (> 50% TBSA or > 25% full-thickness TBSA) burns admitted to three university teaching institutions in China between January 1, 2011 and December 31, 2020. Both 30- and 90-day mortality were assessed by collating demographic data, burn causes, admission TBSA, % full-thickness TBSA, Baux score, Abbreviated Burn Severity Index (ABSI) score, and Sequential Organ Failure Assessment (SOFA) score, shock at admission and the presence of an inhalation injury. GI dysfunction included abdominal distension, nausea/vomiting, diarrhoea/constipation, GI ulcer/haemorrhage, paralytic ileus, feeding intolerance and ACS. Surgeries, length of intensive care unit (ICU) stay, pain control [in morphine milligram equivalents (MME)] and overall length of hospital stay (LOHS) were recorded. RESULTS: We analyzed 328 patients [75.6% male, mean age: (41.6 ± 13.6) years] with a median TBSA of 62.0% (41.0-80.0%); 256 (78.0%) patients presented with extensive burns. The 90-day mortality was 23.2% (76/328), with 64 (84.2%) of these deaths occurring within 30 d and 25 (32.9%) occurring within 7 d. GI dysfunction was experienced by 45.4% of patients and had a significant effect on 90-day mortality [odds ratio (OR) = 14.070, 95% confidence interval (CI) 5.886-38.290, P < 0.001]. Multivariate analysis showed that GI dysfunction was associated with admission SOFA score and % full-thickness TBSA. Overall, 88.2% (67/76) of deceased patients had GI dysfunction [hazard ratio (HR) for death of GI dysfunction = 5.951], with a survival advantage for functional disorders (diarrhoea, constipation, or nausea/vomiting) over GI ulcer/haemorrhage (P < 0.001). CONCLUSION: Patients with severe burns have an unfavourable prognosis, as nearly one-fifth died within 90 d. Half of our patients had comorbidities related to GI dysfunction, among which GI ulcers and haemorrhages were independently correlated with 90-day mortality. More attention should be given to severe burn patients with GI dysfunction.

Discovery of Novel α-Methylene-γ-Butyrolactone Derivatives Containing Vanillin Moieties as Antiviral and Antifungal Agents.

On the basis of the structure of nicotlactone A (L1), a series of novel α-methylene-γ-butyrolactone derivatives B1-B43 were designed and synthesized by structure simplification and active fragment replacement strategies, and their antiviral and antifungal activities were evaluated. The bioassay studies indicated that many target compounds possessed good to excellent antiviral activity against tobacco mosaic virus (TMV) and some of these compounds exhibited specific antifungal activities against Valsa mali and Fusarium graminearum. Compound B32 exhibited the best anti-TMV activity (inactivation effect, 88.9%; protection effect, 65.8%; curative effect, 52.8%) in vivo at 500 mg/L, which is significantly higher than that of commercial virucides ribavirin and ningnanmycin. The inhibition effect of compound B32 was also visualized by the inoculation test using green fluorescent protein (GFP)-labeled TMV. The preliminary antiviral mechanism of compound B32 was investigated. Transmission electron microscopy (TEM) showed that compound B32 could destroy the integrity of virus particles. Then, molecular docking and isothermal titration calorimetry (ITC) analysis further demonstrated that compound B32 exhibited a strong binding affinity to the TMV coat protein with a dissociation constant (Kd) of 3.06 µM, superior to ribavirin. Thus, we deduced that compound B32 may interfere with the self-assembly of TMV particles by binding TMV coat protein (CP). In addition, compound B28 showed good in vitro activity against F. graminearum with an inhibition rate of 90.9% at 50 mg/L, which was greater than that of fluxapyroxad (59.1%) but lower than that of the commercial fungicide carbendazim (96.8%). The present study provides support for the application of these α-methylene-γ-butyrolactone derivatives as novel antiviral and antifungal agents in crop protection.

Electrochemical Trifluoromethylthiolation and Spirocyclization of Alkynes with AgSCF3: Access to SCF3-Containing Spiro[5,5]trienones.

A novel and efficient strategy for trifluoromethylthiolation and dearomatization of activated alkynes with stable and readily available AgSCF3 has been developed. Reported herein is the unprecedented electrochemical generation of the SCF3 radical in the absence of persulfate for the synthesis of SCF3-containing spiro[5,5]trienones in good yields via a 6-exo-trig radical cyclization.

Ethnobotanical survey of medicinal plants in Gaomi, China.

ETHNOPHARMACOLOGICAL RELEVANCE: The uses of medicinal plants have a long history and become one of the important sources of the health cares in Gaomi City, Shandong Province, China. However, limited studies have been done to identify these medicinal plant species and to scientifically document their associated traditional knowledge. Many species used by indigenous people could potentially represent a novel resource of medicine. The study can aid in further investigations of modern pharmacology and planning of the wild species conservation. AIM OF THE STUDY: The study aimed to investigate and record the medicinal plant taxa and their associated traditional knowledge in Gaomi City, China. MATERIALS AND METHODS: Field study was conducted from March 2018 to May 2019 with 184 residents of Gaomi City. Traditional medicinal plant specimens were collected from the field with the help of these residents and were identified and authenticated in the Herbarium of the School of Pharmacy, Binzhou Medical University. Ethnobotanical knowledge was collected by semi-structured face-to-face interviews. The quantitative data were analyzed by using the informant consensus factor (ICF) method and the number of citations. RESULTS: A total of 181 species belonging to 137 genera and 65 families were collected in Gaomi City. Asteraceae was the predominant family and Fabaceae took the second place. River basins and the southern hills in Gaomi were rich in vegetation. However, the cultivated area of medicinal plants only accounted for 10% of agricultural acreage. The main preparation method was decocting (170, 94.48%) and the most frequent mode of administration was oral (177, 97.97%). The highest numerical ICF value was recorded for treating endocrine, metabolic, and nutritional (ICF: 0.85) conditions. Seven of the medicinal plant species used by the people in Gaomi have not been reported previously in China. Verbena officinalis L. was found in Gaomi City, which is a new distribution record for this species. CONCLUSIONS: People in Gaomi hold valuable knowledge about the use of medicinal plants; however, their knowledge has not been comprehensively documented. The therapeutic uses of the documented medicinal plants will provide a basis for further pharmacological and phytochemical investigations. Additionally, the result of this study indicated that the elder people in Gaomi have more traditional knowledge of plant medicines than the younger ones.

Circulating extracellular vesicles from patients with valvular heart disease induce neutrophil chemotaxis via FOXO3a and the inhibiting role of dexmedetomidine.

We previously demonstrated that circulating extracellular vesicles (EVs) from patients with valvular heart disease (VHD; vEVs) contain inflammatory components and inhibit endothelium-dependent vasodilation. Neutrophil chemotaxis plays a key role in renal dysfunction, and dexmedetomidine (DEX) can reduce renal dysfunction in cardiac surgery. However, the roles of vEVs in neutrophil chemotaxis and effects of DEX on vEVs are unknown. Here, we investigated the impact of vEVs on neutrophil chemotaxis in kidneys and the influence of DEX on vEVs. Circulating EVs were isolated from healthy subjects and patients with VHD. The effects of EVs on chemokine generation, forkhead box protein O3a (FOXO3a) pathway activation and neutrophil chemotaxis on cultured human umbilical vein endothelial cells (HUVECs) and kidneys in mice and the influence of DEX on EVs were detected. vEVs increased FOXO3a expression, decreased phosphorylation of Akt and FOXO3a, promoted FOXO3a nuclear translocation, and activated the FOXO3a signaling pathway in vitro. DEX pretreatment reduced vEV-induced CXCL4 and CCL5 expression and neutrophil chemotaxis in cultured HUVECs via the FOXO3a signaling pathway. vEVs were also found to suppress Akt phosphorylation and activate FOXO3a signaling to increase plasma levels of CXCL4 and CCL5 and neutrophil accumulation in kidney. The overall mechanism was inhibited in vivo with DEX pretreatment. Our data demonstrated that vEVs induced CXCL4-CCL5 to stimulate neutrophil infiltration in kidney, which can be inhibited by DEX via the FOXO3a signaling. Our findings reveal a unique mechanism involving vEVs in inducing neutrophils chemotaxis and may provide a novel basis for using DEX in reducing renal dysfunction in valvular heart surgery.

Molecular determinants of cytochrome C oxidase IV mRNA axonal trafficking.

In previous studies, we identified a putative 38-nucleotide stem-loop structure (zipcode) in the 3' untranslated region of the cytochrome c oxidase subunit IV (COXIV) mRNA that was necessary and sufficient for the axonal localization of the message in primary superior cervical ganglion (SCG) neurons. However, little is known about the proteins that interact with the COXIV-zipcode and regulate the axonal trafficking and local translation of the COXIV message. To identify proteins involved in the axonal transport of the COXIV mRNA, we used the biotinylated 38-nucleotide COXIV RNA zipcode as bait in the affinity purification of COXIV zipcode binding proteins. Gel-shift assays of the biotinylated COXIV zipcode indicated that the putative stem-loop structure functions as a nucleation site for the formation of ribonucleoprotein complexes. Mass spectrometric analysis of the COXIV zipcode ribonucleoprotein complex led to the identification of a large number RNA binding proteins, including fused in sarcoma/translated in liposarcoma (FUS/TLS), and Y-box protein 1 (YB-1). Validation experiments, using western analyses, confirmed the presence of the candidate proteins in the COXIV zipcode affinity purified complexes obtained from SCG axons. Immunohistochemical studies show that FUS, and YB-1 are present in SCG axons. Importantly, RNA immunoprecipitation studies show that FUS, and YB-1 interact with endogenous axonal COXIV transcripts. siRNA-mediated downregulation of the candidate proteins FUS and YB-1 expression in the cell-bodies diminishes the levels of COXIV mRNA in the axon, suggesting functional roles for these proteins in the axonal trafficking of COXIV mRNA.

Axonal localization and mitochondrial association of precursor microRNA 338.

MicroRNAs (miRNAs) selectively localize to subcompartments of the neuron, such as dendrites, axons, and presynaptic terminals, where they regulate the local protein synthesis of their putative target genes. In addition to mature miRNAs, precursor miRNAs (pre-miRNAs) have also been shown to localize to somatodendritic and axonal compartments. miRNA-338 (miR-338) regulates the local expression of several nuclear-encoded mitochondrial mRNAs within axons of sympathetic neurons. Previous work has shown that precursor miR-338 (pre-miR-338) introduced into the axon can locally be processed into mature miR-338, where it can regulate local ATP synthesis. However, the mechanisms underlying the localization of pre-miRNAs to the axonal compartment remain unknown. In this study, we investigated the axonal localization of pre-miR-338. Using proteomic and biochemical approaches, we provide evidence for the localization of pre-miR-338 to distal neuronal compartments and identify several constituents of the pre-miR-338 ribonucleoprotein complex. Furthermore, we found that pre-miR-338 is associated with the mitochondria in axons of superior cervical ganglion (SCG) neurons. The maintenance of mitochondrial function within axons requires the precise spatiotemporal synthesis of nuclear-encoded mRNAs, some of which are regulated by miR-338. Therefore, the association of pre-miR-338 with axonal mitochondria could serve as a reservoir of mature, biologically active miRNAs, which could coordinate the intra-axonal expression of multiple nuclear-encoded mitochondrial mRNAs.

Dysbindin-associated proteome in the p2 synaptosome fraction of mouse brain.

The gene DTNBP1 encodes the protein dysbindin and is among the most promising and highly investigated schizophrenia-risk genes. Accumulating evidence suggests that dysbindin plays an important role in the regulation of neuroplasticity. Dysbindin was reported to be a stable component of BLOC-1 complex in the cytosol. However, little is known about the endogenous dysbindin-containing complex in the brain synaptosome. In this study, we investigated the associated proteome of dysbindin in the P2 synaptosome fraction of mouse brain. Our data suggest that dysbindin has three isoforms associating with different complexes in the P2 fraction of mouse brain. To facilitate immunopurification, BAC transgenic mice expressing a tagged dysbindin were generated, and 47 putative dysbindin-associated proteins, including all components of BLOC-1, were identified by mass spectrometry in the dysbindin-containing complex purified from P2. The interactions of several selected candidates, including WDR11, FAM91A1, snapin, muted, pallidin, and two proteasome subunits, PSMD9 and PSMA4, were verified by coimmunoprecipitation. The specific proteasomal activity is significantly reduced in the P2 fraction of the brains of the dysbindin-null mutant (sandy) mice. Our data suggest that dysbindin is functionally interrelated to the ubiquitin-proteasome system and offer a molecular repertoire for future study of dysbindin functional networks in brain.

The novel caspase-3 substrate Gap43 is involved in AMPA receptor endocytosis and long-term depression.

The cysteine protease caspase-3, best known as an executioner of cell death in apoptosis, also plays a non-apoptotic role in N-methyl-d-aspartate receptor-dependent long-term depression of synaptic transmission (NMDAR-LTD) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor endocytosis in neurons. The mechanism by which caspase-3 regulates LTD and AMPA receptor endocytosis, however, remains unclear. Here, we addressed this question by using an enzymatic N-terminal peptide enrichment method and mass spectrometry to identify caspase-3 substrates in neurons. Of the many candidates revealed by this proteomic study, we have confirmed BASP1, Dbn1, and Gap43 as true caspase-3 substrates. Moreover, in hippocampal neurons, Gap43 mutants deficient in caspase-3 cleavage inhibit AMPA receptor endocytosis and LTD. We further demonstrated that Gap43, a protein well-known for its functions in axons, is also localized at postsynaptic sites. Our study has identified Gap43 as a key caspase-3 substrate involved in LTD and AMPA receptor endocytosis, uncovered a novel postsynaptic function for Gap43 and provided new insights into how long-term synaptic depression is induced.

A coordinated proteomic approach for identifying proteins that interact with the E. coli ribosomal protein S12.

The bacterial ribosomal protein S12 contains a universally conserved D88 residue on a loop region thought to be critically involved in translation due to its proximal location to the A site of the 30S subunit. While D88 mutants are lethal this residue has been found to be post-translationally modified to ß-methylthioaspartic acid, a post-translational modification (PTM) identified in S12 orthologs from several phylogenetically distinct bacteria. In a previous report focused on characterizing this PTM, our results provided evidence that this conserved loop region might be involved in forming multiple proteins-protein interactions ( Strader , M. B. ; Costantino , N. ; Elkins , C. A. ; Chen , C. Y. ; Patel , I. ; Makusky , A. J. ; Choy , J. S. ; Court , D. L. ; Markey , S. P. ; Kowalak , J. A. A proteomic and transcriptomic approach reveals new insight into betamethylthiolation of Escherichia coli ribosomal protein S12. Mol. Cell. Proteomics 2011 , 10 , M110 005199 ). To follow-up on this study, the D88 containing loop was probed to identify candidate binders employing a two-step complementary affinity purification strategy. The first involved an endogenously expressed S12 protein containing a C-terminal tag for capturing S12 binding partners. The second strategy utilized a synthetic biotinylated peptide representing the D88 conserved loop region for capturing S12 loop interaction partners. Captured proteins from both approaches were detected by utilizing SDS-PAGE and one-dimensional liquid chromatography-tandem mass spectrometry. The results presented in this report revealed proteins that form direct interactions with the 30S subunit and elucidated which are likely to interact with S12. In addition, we provide evidence that two proteins involved in regulating ribosome and/or mRNA transcript levels under stress conditions, RNase R and Hfq, form direct interactions with the S12 conserved loop, suggesting that it is likely part of a protein binding interface.

[Influence of pulmonary function after combined thoracoscopic and laparoscopic esophagectomy for the treatment of esophageal carcinoma].

OBJECTIVES: To investigate the influence of combined thoracoscopic and laparoscopic esophagectomy for early postoperative pulmonary function, and to study the relative factors for postoperative pulmonary complications. METHODS: From September 2009 to December 2010, 61 patients with esophageal cancer had undergone esophagectomy surgery, of which 32 patients had undergone combined thoracoscopic and laparoscopic esophagectomy (CTLE group), and 29 patients had undergone open three-field esophagectomy (open group). Pulmonary function, including forced vital capacity (FVC), forced expiratory volume in 1 second (FEV(1)) were measured on the 1(th) preoperative day, 5(th) and 10(th) postoperative day, and arterial blood gas analyses were performed during the same period. Meanwhile, pain scores and other potentially relevant factors were recorded as well. RESULTS: Preoperative pulmonary function and arterial blood gas analysis, including FEV(1)%, FVC%, PaO2 in two groups had no significant difference (t = -1.608 to 0.709, P = 0.113 to 0.481). On the 10(th) postoperative day, FEV(1)%, FVC%, PaO2, and SaO2 of two groups were significantly different (FEV(1)%: 77% ± 17% vs. 53% ± 13%, t = 6.241, P = 0.000; FVC%: 78% ± 13% vs. 57% ± 16%, t = 5.549, P = 0.000; PaO2: (87 ± 9) mmHg vs. (79 ± 14) mmHg, t = 2.477, P = 0.017; SaO2: 96% ± 3% vs. 94% ± 2%, t = 2.313, P = 0.024; 1 mmHg = 0.133 kPa). Pain score of CTLE group was lower than open group, and the scores of two groups had significant difference before the 5(th) day after surgery (t = -4.398 to -1.815, P = 0.000 to 0.049). Postoperative pulmonary complications of CTLE group was lower than open group (6/32 vs. 12/29, χ(2) = 3.745, P = 0.049). CONCLUSIONS: Combined thoracoscopic and laparoscopic esophagectomy has advantages on early postoperative pulmonary function. It can relatively reduce the incidence of pulmonary complications after surgery.

[Relationships between soil and rocky desertification in typical karst mountain area based on redundancy analysis].

Redundancy analysis (RDA) was employed to reveal the relationships between soil and rocky desertification through vegetation investigation and analysis of soil samples collected in typical karst mountain area of southwest Guizhou Province. The results showed that except TP, TK and ACa, all other variables including SOC, TN, MBC, ROC, DOC, available nutrients and basal respiration showed significant downward trends during the rocky desertification process. RDA results showed significant correlations between different types of desertification and soil variables, described as non-degraded > potential desertification > light desertification > moderate desertification > severe desertification. Moreover, RDA showed that using SOC, TN, AN, and BD as soil indicators, 74.4% of the variance information on soil and rocky desertification could be explained. Furthermore, the results of correlation analysis showed that soil variables were significantly affected by surface vegetation. Considering the ecological function of the aboveground vegetation and the soil quality, Zanthoxylum would be a good choice for restoration of local vegetation in karst mountain area.

Osteogenic differentiation of human periodontal ligament stem cells expressing lentiviral NEL-like protein 1.

NEL-like protein 1 (NELL1) is a newly identified secreted protein involved in craniosynostosis and has been found to promote osteogenic differentiation of mesenchymal stem cells. The objective of this study was to investigate the effect of NELL1 on osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) and the potential underlying mechanism. hPDLSCs underwent lentivirus-mediated NELL1 transfection (Lenti-NELL1) and markers of osteogenesis were assessed [alkaline phosphate (ALP), osteocalcin (OCN) and calcium deposition] to evaluate the effect of NELL1 on the differentiation of these cells. Quantitative polymerase chain reaction (qPCR) was employed to measure the mRNA expression of Msx2 and Runx2, and Lenti-enhanced green fluorescent protein (EGFP) served as a control. Western blot analysis and qPCR analyses confirmed that Lenti-NELL1-transfected hPDLSCs could express NELL1. Compared with the Lenti-EGFP group, ALP, OCN, calcium deposition and Msx2 mRNA expression were markedly increased (P<0.01), but there was no significant difference in Runx2 mRNA expression between the two groups (P>0.01). hPDLSCs can be transfected by Lenti-NELL1 and can stably express NELL1. NELL1 is able to promote the osteogenic differentiation of hPDLSCs, which may be related to the downregulation of Msx2 expression. Lenti-NELL1 transfection can be used during in vitro gene therapy for periodontal regeneration.

RNA binding targets aminoacyl-tRNA synthetases to translating ribosomes.

Here, we examine tRNA-aminoacyl synthetase (ARS) localization in protein synthesis. Proteomics reveals that ten of the twenty cytosolic ARSs associate with ribosomes in sucrose gradients: phenylalanyl-RS (FRS), and the 9 ARSs that form the multi-ARS complex (MSC). Using the ribopuromycylation method (RPM) for localizing intracellular translation, we show that FRS and the MSC, and to a lesser extent other ARSs, localize to translating ribosomes, most strikingly when translation is restricted to poxvirus or alphavirus factories in infected cells. Immunoproximity fluorescence indicates close proximity between MSC and the ribosome. Stress induced-translational shutdown recruits the MSC to stress-granules, a depot for mRNA and translation components. MSC binding to mRNA provides a facile explanation for its delivery to translating ribosomes and stress granules. These findings, along with the abundance of the MSC (9 × 10(6) copies per cell, roughly equimolar with ribosomes), is consistent with the idea that MSC specificity, recently reported to vary with cellular stress (Netzer, N., Goodenbour, J. M., David, A., Dittmar, K. A., Jones, R. B., Schneider, J. R., Boone, D., Eves, E. M., Rosner, M. R., Gibbs, J. S., Embry, A., Dolan, B., Das, S., Hickman, H. D., Berglund, P., Bennink, J. R., Yewdell, J. W., and Pan, T. (2009) Nature 462, 522-526) can be modulated at the level of individual mRNAs to modify decoding of specific gene products.

A proteomic and transcriptomic approach reveals new insight into beta-methylthiolation of Escherichia coli ribosomal protein S12.

ß-methylthiolation is a novel post-translational modification mapping to a universally conserved Asp 88 of the bacterial ribosomal protein S12. This S12 specific modification has been identified on orthologs from multiple bacterial species. The origin and functional significance was investigated with both a proteomic strategy to identify candidate S12 interactors and expression microarrays to search for phenotypes that result from targeted gene knockouts of select candidates. Utilizing an endogenous recombinant E. coli S12 protein with an affinity tag as bait, mass spectrometric analysis identified candidate S12 binding partners including RimO (previously shown to be required for this post-translational modification) and YcaO, a conserved protein of unknown function. Transcriptomic analysis of bacterial strains with deleted genes for RimO and YcaO identified an overlapping transcriptional phenotype suggesting that YcaO and RimO likely share a common function. As a follow up, quantitative mass spectrometry additionally indicated that both proteins dramatically impacted the modification status of S12. Collectively, these results indicate that the YcaO protein is involved in ß-methylthiolation of S12 and its absence impairs the ability of RimO to modify S12. Additionally, the proteomic data from this study provides direct evidence that the E. coli specific ß-methylthiolation likely occurs when S12 is assembled as part of a ribosomal subunit.

Preparative enrichment and separation of astragalosides from Radix Astragali extracts using macroporous resins.

The enrichment and separation of astragalosides I-IV (AGs I-IV) were studied on eight macroporous resins in the present study. SA-3 resin offered the best adsorption and desorption capacities for AGs I-IV than other resins. The models of adsorption kinetics were investigated in order to elucidate the mechanism of adsorption. The pseudo-second-order model was the better choice than the pseudo-first-order model to describe the adsorption behavior of AGs I-IV onto SA-3 resin. The equilibrium experimental data were well fitted to Langmuir and Freundlich isotherms. SA-3 resin adsorption chromatography tests were carried out to optimize the separation process of AGs I-IV from Radix Astragali extracts. With the optimum parameters for adsorption and desorption, the contents of AGs I-IV were 8.78-, 11.60-, 10.52- and 11.28-fold increased with the recovery yields being 65.88, 90.92, 84.25 and 94.17%, respectively. The preparative enrichment and separation of AGs I-IV from Radix Astragali extracts can be easily and effectively achieved by SA-3 resin adsorption chromatography. The developed methodology can also be referenced for the separation of other active constituents from herbal materials and manufacture of Radix Astragali products.

Enhanced extraction of astragalosides from Radix Astragali by negative pressure cavitation-accelerated enzyme pretreatment.

The optimal conditions for extraction of astragalosides III and IV (AGs III and IV) in Radix Astragali by negative pressure cavitation-accelerated enzyme pretreatment were studied on the basis of a Box-Behnken design and response surface methodology. Experimental results showed that negative pressure, amount of enzyme and incubation temperature were the main factors governing the enzyme pretreatment of Radix Astragali. The optimum parameters were obtained as follows: negative pressure -0.08 Mpa, amount of enzyme 1.48% (w/w of materials) and incubation temperature 45 degrees C. Under the optimal conditions, the maximal extraction yields of AGs III and IV were 0.103 and 0.325 mg/g, which were 41.67% and 65.31% increased as compared to those without enzyme pretreatment, respectively. The effect of negative pressure cavitation and enzyme pretreatment on the structural changes of plant cells was observed by scanning electron microscopy. In conclusion, negative pressure cavitation-accelerated enzyme pretreatment was proved to be environment-friendly and economical, and could be used in secondary metabolites production.

[Establishment of animal model of temporomandibular joint synovitis and its histological investigation].

OBJECTIVE: To establish a stable animal model of temporomandibular joint (TMJ) synovitis. METHODS: Sixteen 6-week-old male SD rats were classified into four groups, control group, occlusal dimension increase group, masseter resection group, occlusal dimension increase group and masseter resection group. The rats in the occlusal dimension increase group were adhered composite resin to their maxillary molars in order to increase the occlusal vertical dimension when they were 9-week-old. The rats in the masseter resection group were cut off their bilateral masseter muscles when they were 6-week-old. In the occlusal dimension increase group and masseter resection group, rats' bilateral masseter muscles were resected and occlusal vertical dimension was increased. All rats were sacrificed at their 10 weeks old. TMJ samples were prepared for histology to evaluate the animal model. RESULTS: The control group showed non-inflammatory changes. The occlusal dimension increase group and the masseter resection group showed vascular dilation and synovial lining proliferation, but there were no statistically significant differences between the two groups (P > 0.05). Compared to the two disposed groups, the occlusal dimension increase group and masseter resection group showed significant inflammatory changes (P < 0.05), including synovial lining proliferation, vascular dilation and fibrin deposit. CONCLUSION: The animal model of TMJ synovitis created in the present investigation could simulate the real pathological features of synovitis in vivo, and this animal model showed the obvious merits of high stability and reproduction.