COSA-1 mediated pro-crossover complex formation promotes meiotic crossing over in C. elegans.

Accurate chromosome segregation during meiosis requires the establishment of at least one crossover (CO) between each pair of homologous chromosomes. CO formation depends on a group of conserved pro-CO proteins, which colocalize at CO-designated sites during late meiotic prophase I. However, it remains unclear whether these pro-CO proteins form a functional complex and how they promote meiotic CO formation in vivo. Here, we show that COSA-1, a key component required for CO formation, interacts with other pro-CO factors, MSH-5 and ZHP-3, via its N-terminal disordered region. Point mutations that impair these interactions do not affect CO designation, but they strongly hinder the accumulation of COSA-1 at CO-designated sites and result in defective CO formation. These defects can be partially bypassed by artificially tethering an interaction-compromised COSA-1 derivate to ZHP-3. Furthermore, we revealed that the accumulation of COSA-1 into distinct foci is required to assemble functional 'recombination nodules'. These prevent early CO-designated recombination intermediates from being dismantled by the RTEL-1 helicase and protect late recombination intermediates, such as Holliday junctions, until they are resolved by CO-specific resolvases. Altogether, our findings provide insight into COSA-1 mediated pro-CO complex assembly and its contribution to CO formation.

Near-infrared laser-assisted Ag@Chi-PB nanocompounds for synergistically eradicating multidrug-resistant bacteria and promoting diabetic abscess healing.

Chronic wound infections, particularly multidrug-resistant microbe-caused infections, have imposed severe challenges in clinical administration. The therapeutic effectiveness of the current strategy using conventional antibiotics is extremely unsatisfactory. The development of novel treatment strategies to inhibit the infections caused by multidrug-resistant bacteria is highly desired. In this work, based on the combination of nanocompounds with the assistance of NIR laser, an antibacterial strategy was designed for MRSA-infected abscesses in diabetic mice. The nanocompounds named Ag@Chi-PB were prepared by using chitosan-coated Prussian blue (PB) as a nanocarrier for silver nanoparticles anchoring. Combined with near-infrared (NIR) laser, the nanocompounds were more efficient at killing Escherichia coli (E. coli) and Methicillin-resistant staphyllococcus aureus (MRSA) in vitro. Notably, MRSA was significantly removed in vivo and promoted diabetic abscess healing by the combined therapy of this nanocompound and NIR laser, owing to the synergistic antibacterial effect of photothermal therapy and release of Ag+. Meanwhile, the nanocompound showed satisfactory biocompatibility and superior biosafety. Collectively, the combination therapy of this nanocompound with the assistance of NIR laser may represent a promising strategy for clinical anti-infection.

Sexual Dimorphism in the Limb Bones of Asiatic Toad (Bufo gargarizans) in Relation to Sexual Selection.

Sexual dimorphism is often considered to be the result of differences in the intensity of sexual selection between sexes. From this point of view, the sexual dimorphism of the limb bones of the Bufo gargarizans in southwest China was studied. Results showed that the fore- and hindlimb skeletons of this species were sexually dimorphic in anatomy. The humerus, radioulna, and total lengths of the forelimb skeleton of males were substantially longer than those of females, but the hand length of males was smaller than that of females. Several other features of males, such as deltoid and medial crest areas and humerus and radioulnar weights, were also significantly larger than those of females. The femoris, tibiofibula, talus-calcaneus, and foot lengths; total hindlimb skeleton length; and femoral upper crest areas of males were significantly greater than those of females. However, no significant intersexual difference in femoris and tibiofibular weights was observed. These findings suggested that robust forelimb bones and long hindlimb bones could contribute to the mating success of males; if so, sexual selection promotes the evolution of sexual size and shape dimorphism in the limb bones of the B. gargarizans.

Metabolic Adaption of Flexor Carpi Radialis to Amplexus Behavior in Asiatic Toads (Bufo gargarizans).

Amplexus is a type of mating behavior among toads that is essential for successful external fertilization. Most studies have primarily focused on the behavioral diversity of amplexus, and less is known regarding the metabolic changes occurring in amplectant males. The aim of this study was to compare the metabolic profiles of amplectant Asiatic toad (Bufo gargarizans) males in the breeding period (BP group) and the resting males in the non-breeding period (NP group). A metabolomic analysis was conducted on the flexor carpi radialis (FCR), an essential forelimb muscle responsible for clasping during courtship. A total of 66 differential metabolites were identified between the BP and NP groups, including 18 amino acids, 12 carbohydrates, and 8 lipids, and they were classified into 9 categories. Among these differential metabolites, 13 amino acids, 11 carbohydrates, and 7 lipids were significantly upregulated in the BP group compared to the NP group. In addition, a KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis identified 17 significant metabolic pathways, including ABC transporters, aminoacyl-tRNA biosynthesis, arginine biosynthesis, pantothenate and CoA biosynthesis, and fructose and mannose metabolism. These results suggest that amplectant male toads are metabolically more active than those during the non-breeding period, and this metabolic adaptation increases the likelihood of reproductive success.

Hangover headache and its behavioral changes in rats.

Objectives: The present study aims to establish and evaluate a rat model for hangover headaches caused by alcoholic drinks. Materials and Methods: Chronic migraine (CM) model rats were divided into 3 groups, and intragastrically administered alcoholic drinks (sample A, B, or C) to simulate hangover headache attacks. The withdrawal threshold for the hind paw/face and the thermal latency of hind paw withdrawal were detected after 24 hr. Serum was collected from the periorbital venous plexus of rats in each group, and enzymatic immunoassays were used to determine the serum levels of calcitonin gene-related peptide (CGRP), substance P (SP), and nitric oxide (NO). Results: Compared with the control group, the mechanical hind paw pain threshold was significantly lower in rats administered Samples A and B after 24 hr; however, no significant difference was observed across groups for the thermal pain threshold. The mechanical threshold for periorbital pain was only significantly reduced in rats administered Sample A. Immunoassays further indicated that serum levels of SP in the group administered Sample A were significantly higher than those in the control group; the serum levels of NO and CGRP were significantly higher in the group of rats receiving Sample B. Conclusion: We successfully developed an effective and safe rat model for investigating alcohol drink induced hangover headaches. This model could be used to investigate the mechanisms associated with hangover headaches for the development of novel and promising candidates for the future treatment or prophylaxis of hangover headaches.

Brain size predicts foraging and escaping abilities in the paddy frogs.

The three experiments revealed that successful individuals with spatial learning and escaping had relatively larger brains than unsuccessful ones in three species of the paddy frogs. We first provided experimental evidence for whole-brain size as a predictor of cognitive abilities in the paddy frogs. Our findings support the claim that brain size can reflect an animal's spatial learning and escaping abilities and enhance our understanding of larger brains evolved with better cognitive abilities in frogs.

Activation of Esterase D by FPD5 Inhibits Growth of A549 Lung Cancer Cells via JAB1/p53 Pathway.

Esterase D (ESD) is widely distributed in mammals, and it plays an important role in drug metabolism, detoxification, and biomarkers and is closely related to the development of tumors. In our previous work, we found that a chemical small-molecule fluorescent pyrazoline derivative, FPD5, an ESD activator, could inhibit tumor growth by activating ESD, but its molecular mechanism is still unclear. Here, by using RNA interference (RNAi), andco-immunoprecipitation techniques, we found that ESD suppressed the nucleus exportation of p53 through reducing the interaction between p53 and JAB1. The protein level of p53 in the nucleus was upregulated and the downstream targets of p53 were found by Human Gene Expression Array. p53 inhibited the expression of CDCA8 and CDC20. Lastly, the cell cycle of A549 cells was arrested at the G0/G1 phase. Together, our data suggest that ESD inhibited the cancer cell growth by arresting the cell cycle of A549 cells via the JAB1/p53 signaling pathway. Our findings provide a new insight into how to inhibit the growth of lung cancer with the activation of ESD by FPD5.

Ofloxacin-loaded HMPB NPs for Klebsiella pneumoniae eradication in the surgical wound with the combination of PTT.

Klebsiella pneumoniae (K. pneumoniae) is a common bacterium whose drug-resistant can cause surgical failures and incurable infections in hospital patients. Thus, how to reverse or delay the resistance induction has become a great challenge for development antiresistant drug. Recently, the combination of nanomaterial-loaded antibiotics with photothermal therapy showed the efficient antibacteria ability under a low dosage of antibiotics. In this study, a nanocomposite of HMPB NPs with inherent photothermal therapy capability was used to eradicate K. pneumoniae after loading with Ofloxacin, an antibiotic against K. pneumoniae in vitro and in vivo. The nanocomplexes named as Ofloxacin@HMPB@HA NPs showed a higher effect against K. pneumoniae by destroying cell integrity and inducing ATP leakage with the assistance of laser irradiation, compared with sole Ofloxacin@HMPB@HA NPs or laser irradiation. Surgical wound infection assay further demonstrated the efficient killing K. pneumoniae and promoting the formation of new tissues, as well, which was reflected by the rapid healing of surgical wound. In summary, these results indicate the great potential of this combinational tactic based on Ofloxacin@HMPB@HA NPs for preventing the failure caused by K. pneumoniae infection.

Esterase D stabilizes FKBP25 to suppress mTORC1.

BACKGROUND: Esterase D (ESD) is a nonspecific esterase that detoxifies formaldehyde. Many reports have stated that ESD activity is associated with a variety of physiological and pathological processes. However, the detailed signaling pathway of ESD remains poorly understood. METHODS: Considering the advantages of the small chemical molecule, our recent work demonstrated that 4-chloro-2-(5-phenyl-1-(pyridin-2-yl)-4,5-dihydro-1H-pyrazol-3-yl) phenol (FPD5) activates ESD, and will be a good tool for studying ESD further. Firstly, we determined the interaction between ESD and FK506 binding protein 25 (FKBP25) by yeast two-hybrid assay and co-immunoprecipitation (CO-IP) and analyzed the phosphorylation levels of mTORC1, P70S6K and 4EBP1 by western blot. Furthermore, we used the sulforhodamine B (SRB) and chick chorioallantoic membrane (CAM) assay to analyze cell viability in vitro and in vivo after treatment with ESD activator FPD5. RESULTS: We screened FKBP25 as a candidate protein to interact with ESD by yeast two-hybrid assay. Then we verified the interaction between ESD and endogenous FKBP25 or ectopically expressed GFP-FKBP25 by CO-IP. Moreover, the N-terminus (1-90 aa) domain of FKBP25 served as the crucial element for their interaction. More importantly, ESD reduced the K48-linked poly-ubiquitin chains of FKBP25 and thus stabilized cytoplasmic FKBP25. ESD also promoted FKBP25 to bind more mTORC1, suppressing the activity of mTORC1. In addition, ESD suppressed tumor cell growth in vitro and in vivo through autophagy. CONCLUSIONS: These findings provide novel evidence for elucidating the molecular mechanism of ESD and ubiquitination of FKBP25 to regulate autophagy and cancer cell growth. The ESD/FKBP25/mTORC1 signaling pathway is involved in inhibiting tumor cell growth via regulating autophagy.

Cytoprotection against Oxidative Stress by Methylnissolin-3-O-ß-d-glucopyranoside from Astragalus membranaceus Mainly via the Activation of the Nrf2/HO-1 Pathway.

Astragalus membranaceus is a famous herb found among medicinal and food plants in East and Southeastern Asia. The Nrf2-ARE assay-guided separation of an extract from Jing liqueur led to the identification of a nontoxic Nrf2 activator, methylnissolin-3-O-ß-d-glucopyranoside (MNG, a component of A. membranaceus). Nrf2 activation by MNG has not been reported before. Using Western Blot, RT-qPCR and imaging, we investigated the cytoprotective effect of MNG against hydrogen peroxide-induced oxidative stress. MNG induced the expression of Nrf2, HO-1 and NQO1, accelerated the translocation of Nrf2 into nuclei, and enhanced the phosphorylation of AKT. The MNG-induced expression of Nrf2, HO-1, and NQO1 were abolished by Nrf2 siRNA, while the MNG-induced expression of Nrf2 and HO-1 was abated and the AKT phosphorylation was blocked by LY294002 (a PI3K inhibitor). MNG reduced intracellular ROS generation. However, the protection of MNG against the H2O2 insult was reversed by Nrf2 siRNA with decreased cell viability. The enhancement of Nrf2 and HO-1 by MNG upon H2O2 injury was reduced by LY294002. These data showed that MNG protected EA.hy926 cells against oxidative damage through the Nrf2/HO-1 and at least partially the PI3K/Akt pathways.

A new activator of esterase D decreases blood cholesterol level through ESD/JAB1/ABCA1 pathway.

Excessively high cholesterol content in the blood leads to nonalcohol fatty liver disease (NAFLD) and arteriosclerosis. Although there are increasing publications and patent applications to lower blood cholesterol with small chemical molecules, limited effective drugs can be available in clinic. It is necessary to uncover new targets and drugs to alleviate high cholesterol. Esterase D (ESD) is abundant in liver and it remains unknown about its role in cholesterol metabolism. Here we reported that small chemical molecule fluorescigenic pyrazoline derivative 5 (FPD5), a new ESD activator, could effectively reverse high blood cholesterol level and prevent fatty liver and arteriosclerosis in apoE-/- mice fed the high-fat diet. We also observed that FPD5 could reduce oxidized low density lipoprotein (oxLDL)-induced formation of foam cells. To further investigate the mechanism of FPD5 action on blood cholesterol modulation, we found that ESD trigged by FPD5 was aggregated in lysosome and interacted with Jun activation domain binding protein 1 (JAB1). ESD served as a deacetylase to remove Thr89 acetylation of JAB1 and increased its activity; thus, promoting the ATP-binding cassette transporters A1 (ABCA1) to accelerate cholesterol efflux. Our findings demonstrate that FPD5 decreases blood cholesterol level to ameliorate NAFLD and arteriosclerosis through ESD/JAB1/ABCA1 pathway, and ESD functions as a novel nonclassical deacetylase that hydrolyzes serine/threonine acetyl group. Our findings not only highlight that FPD5 may be a pioneer drug for alleviating blood cholesterol but also indicate that ESD is a potential drug target that promotes cholesterol metabolism.

Silver nanoparticles coated by green graphene quantum dots for accelerating the healing of MRSA-infected wounds.

Bacterial infection, especially multidrug-resistant bacteria-induced infection, threatens human health seriously, which has posed great challenges for clinical therapy. The overuse of conventional antibiotics has given rise to bacterial resistance that severely restricts the clinical treatment options of conventional antibiotics. The development of highly effective antibacterial materials and therapeutic strategies to inhibit the multidrug-resistant bacteria-induced infections is of great urgency. Although silver nanoparticles (AgNPs) have exhibited certain effectiveness in killing multidrug-resistant bacteria, their antibacterial efficacy and biosafety are still unsatisfactory. In this work, we prepared graphene quantum dots (GQDs) by a green synthesis method with the natural polymer starch as a precursor for uniformly decorating AgNPs to form GQDs coated AgNPs (GQDs@Ag). The nanocomplex was comprehensively characterized, and its antibacterial activity and biosafety were systematically investigated. The characterization results revealed that the successfully constructed GQDs@Ag hybrids with improved dispersion and stability are composed of AgNPs closely and uniformly surrounded by the GQDs. Furthermore, in vitro and in vivo results demonstrated that GQDs@Ag hybrids with superior biosafety showed a markedly enhanced effect in killing MRSA and accelerating MRSA-infected wound healing as compared to AgNPs alone. Collectively, these results suggest that the biocompatible nanosystem of GQDs@Ag exhibits great potential in clinical application for MRSA infection.

Finding the mechanism of esterase D activation by a small molecule.

People with reduced esterase D (ESD) activity are susceptible to many diseases. However, how to activate ESD is still unknown. To address the question, we identified that 4-chloro-2-(5-phenyl-1-(pyridin-2-yl)-4, 5-dihydro-1H-pyrazol-3-yl) phenol (FPD5) could be a good candidate activator for ESD activity. We found that FPD5 could increase ESD activity in a dose-dependent way. FPD5 bound directly to ESD at Lys180 rather than its ubiquitination site Lys213. Site-directed mutagenesis at the binding site or the ubiquitination site inhibited FPD5 action. FPD5 increased the level of ESD mono-ubiquitination and mutESD K213A completely inhibited this action. Our findings highlighted the activation mechanism of ESD via promoting the mono-ubiquitination of ESD.

PB@PDA@Ag nanosystem for synergistically eradicating MRSA and accelerating diabetic wound healing assisted with laser irradiation.

The ever-growing threats of multidrug-resistant bacterial infection and chronic wound healing have created an imperative need for the development of novel antibacterial materials and therapeutic strategies, especially for diabetic patients infected with multidrug-resistant bacteria. In this work, the nanocomplexes named as PB@PDA@Ag were used for eradicating multidrug-resistant bacteria and accelerating wound healing of MRSA-infected diabetic model with the assistance of laser irradiation. In vitro results revealed that the combinational strategy exerted a synergistic effect for anti-MRSA through disrupting cell integrity, producing ROS, declining ATP, and oxidizing GSH, comparing with PB@PDA@Ag or NIR laser irradiation alone. Moreover, in vivo assay demonstrated that this system effectively accelerated MRSA-infected diabetic wound healing by mitigating local inflammatory response and up-regulating VEGF expression on the wound bed. Meanwhile, satisfactory biocompatibility and negligible damage to major organs were observed. Altogether, the aforementioned results indicate that the combinational therapy of PB@PDA@Ag and NIR irradiation shows a great potential application in the field of clinic infection.

Pharmacokinetics and Novel Metabolite Identification of Tartary Buckwheat Extracts in Beagle Dogs Following Co-Administration with Ethanol.

Alcoholic liver disease (ALD) has become a critical global public health issue worldwide. Tartary buckwheat extracts exhibit potential therapeutic effects against ALD due to its antioxidant and anti-inflammatory activities. However, in vivo pharmacokinetics and metabolite identification of tartary buckwheat extracts have not been clearly elucidated. Accordingly, the current manuscript aimed to investigate pharmacokinetics and to identify novel metabolites in beagle dogs following oral co-administration of tartary buckwheat extracts and ethanol. To support pharmacokinetic study, a simple LC-MS/MS method was developed and validated for simultaneous determination of quercetin and kaempferol in beagle dog plasma. The conjugated forms of both analytes were hydrolyzed by ß-glucuronidase and sulfatase followed by liquid-liquid extraction using methyl tert-butyl ether. In addition, another effective approach was established using advanced ultrafast liquid chromatography coupled with a Q-Exactive hybrid quadrupole orbitrap high resolution mass spectrometer to identify the metabolites in beagle dog biological samples including urine, feces, and plasma. The pharmacokinetic study demonstrated that the absolute oral bioavailability for quercetin and kaempferol was determined to be 4.6% and 1.6%, respectively. Oral bioavailability of quercetin and kaempferol was limited in dogs probably due to poor absorption, significant first pass effect, and biliary elimination, etc. Using high resolution mass spectrometric analysis, a total of nine novel metabolites were identified for the first time and metabolic pathways included methylation, glucuronidation, and sulfation. In vivo pharmacokinetics and metabolite identification results provided preclinical support of co-administration of tartary buckwheat extracts and ethanol in humans.

Protein identification and mRNA analysis of phytochrome-regulated genes in Arabidopsis under red light.

Phytochromes are a family of plant photoreceptors that mediate physiological and developmental responses to red and far-red light. According to the affymetrix ATH1 microarray, phytochrome A (phyA) and phytochrome B (phyB) together play a key role in transducing the Rc signals to light-responsive genes. In order to select those red light-responsive genes associated with phyA or phyB, a proteomic approach based on two-dimensional gel electrophoresis (2-DE) was used to compare the protein expression patterns of the phyAphyB double mutant and the wild type of Arabidopsis thaliana (col-4) which grew under constant red light conditions for 7 d. Thirty-two protein spots which exhibited differences in protein abundance were identified by matrix-assisted laser desorption/ionization-time of flight/time of flight mass spectrometry. The expression of ten genes corresponding to ten protein spots was analyzed by a semiquantitative reverse transcription-polymerase chain reaction. Two of the ten genes were confirmed by quantitative PCR (Q-PCR). The results showed that phytochromes may exert their function by regulating mRNA or protein expressions. Proteomic analysis may provide a novel pathway for identifying phytochrome-dependent genes.

Comparative analysis of young panicle proteome in thermo-sensitive genic male-sterile rice Zhu-1S under sterile and fertile conditions.

Proteome analysis was carried out to identify the young panicle proteins during different developmental stages under sterile and fertile conditions. Based on spot quantity and quality, 50 protein spots were analyzed by matrix associated laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and 20 spots were identified. Most of these proteins are closely associated with energy metabolism, protein biosynthesis, cell wall formation and stress responses, which are essential cell activities to the pollen development. Gene expression analysis of three different proteins by semi-quantitative RT-PCR showed that the mRNA level was not correlated exactly with the protein level.

Comparative proteomics analysis of light responses in cryptochrome1-304 and Columbia wild-type 4 of Arabidopsis thaliana.

The blue light photoreceptor mutant cryptochrome1-304 (cry1-304) and Columbia wild-type 4 (col-4) of Arabidopsis thaliana were grown under white light and blue light, and in the dark. To study the difference in protein expression levels between cry1-304 and col-4, a proteomic approach was applied based on 2-D gel electrophoresis. Twenty-one different protein spots were identified by matrix-assisted laser desorption/ionization-time of flight/time of flight mass spectrometry. The expression of four genes corresponding to four protein spots was analyzed by semiquantitative reverse transcription-polymerase chain reaction. We applied analytical procedures to study cry1-304 and col-4, and found that the differentially expressed proteins formed six clusters reflecting co-regulation. This assessment was consistent with the known physiological responses of plants to light.

Blue-light-independent activity of Arabidopsis cryptochromes in the regulation of steady-state levels of protein and mRNA expression.

Cryptochromes are blue-light receptors that mediate blue-light inhibition of hypocotyl elongation and blue-light stimulation of floral initiation in Arabidopsis. In addition to their blue-light-dependent functions, cryptochromes are also involved in blue-light-independent regulation of the circadian clock, cotyledon unfolding, and hypocotyl inhibition. However, the molecular mechanism associated with the blue-light-independent function of cryptochromes remains unclear. We reported here a comparative proteomics study of the light regulation of protein expression. We showed that, as expected, the protein expression of many metabolic enzymes changed in response to both blue light and red light. Surprisingly, some light-regulated protein expression changes are impaired in the cry1cry2 mutant in both blue light and red light. This result suggests that, in addition to mediating blue-light-dependent regulation of protein expression, cryptochromes are also involved in the blue-light-independent regulation of gene expression. Consistent with this hypothesis, the cry1cry2 mutant exhibited reduced changes of mRNA expression in response to not only blue light, but also red light, although the cryptochrome effects on the red-light-dependent gene expression changes are generally less pronounced. These results support a hypothesis that, in addition to their blue-light-specific functions, cryptochromes also play roles in the control of gene expression mediated by the red/far-red-light receptor phytochromes.

[Effects of tree species fine root decomposition on soil active organic carbon].

With incubation test, this paper studied the effects of fine root decomposition of Alnus cremastogyne, Cunninghamia lanceolata and Michelia macclurei on the content of soil active organic carbon at 9 degrees C , 14 degrees C , 24 degrees C and 28 degrees C. The results showed that the decomposition rate of fine root differed significantly with test tree species, which was decreased in the order of M. macclurei > A. cremastogyne > C. lanceolata. The decomposition rate was increased with increasing temperature, but declined with prolonged incubation time. Fine root source, incubation temperature, and incubation time all affected the contents of soil microbial biomass carbon and water-soluble organic carbon. The decomposition of fine root increased soil microbial biomass carbon and water-soluble organic carbon significantly, and the effect decreased in the order of M. macclurei > A. cremastogyne > C. lanceolata. Higher contents of soil microbial biomass carbon and water-soluble organic carbon were observed at medium temperature and middle incubation stage. Fine root decomposition had less effect on the content of soil readily oxidized organic carbon.