Synthetic peptides that form nanostructured micelles have potent antibiotic and antibiofilm activity against polymicrobial infections.

The emergence of multidrug-resistant bacterial pathogens is a growing threat to global public health. Here, we report the development and characterization of a panel of nine-amino acid residue synthetic peptides that display potent antibacterial activity and the ability to disrupt preestablished microbial biofilms. The lead peptide (Peptide K6) showed bactericidal activity against Pseudomonas aeruginosa and Staphylococcus aureus in culture and in monocultures and mixed biofilms in vitro. Biophysical analysis revealed that Peptide K6 self-assembled into nanostructured micelles that correlated with its strong antibiofilm activity. When surface displayed on the outer membrane protein LamB, two copies of the Peptide K6 were highly bactericidal to Escherichia coli. Peptide K6 rapidly increased the permeability of bacterial cells, and resistance to this toxic peptide occurred less quickly than that to the potent antibiotic gentamicin. Furthermore, we found that Peptide K6 was safe and effective in clearing mixed P. aeruginosa-S. aureus biofilms in a mouse model of persistent infection. Taken together, the properties of Peptide K6 suggest that it is a promising antibiotic candidate and that design of additional short peptides that form micelles represents a worthwhile approach for the development of antimicrobial agents.

Discovery of Unusual Ajmaline-Macroline Type Bisindole Alkaloids from Alstonia macrophylla by Building Blocks-Based Molecular Networking.

Three unusual ajmaline-macroline type bisindole alkaloids, alsmaphylines A-C, together with their postulated biogenetic precursors, were isolated from the stem barks and leaves of Alstonia macrophylla via the building blocks-based molecular network (BBMN) strategy. Alsmaphyline A represents a rare ajmaline-macroline type bisindole alkaloid with an S-shape polycyclic ring system. Alsmaphylines B and C are two novel ajmaline-macroline type bisindole alkaloids with N-1-C-21' linkages, and the former possesses an unconventional stacked conformation due to the presence of intramolecular noncovalent interactions. The chemical structures including absolute configurations of alsmaphylines A-C were established by comprehensive spectroscopic analyses, electronic circular dichroism (ECD) calculations, and single-crystal X-ray crystallography. In addition, a plausible biosynthetic pathway of these bisindole alkaloids as well as their ability to promote the protein synthesis on HT22 cells were discussed.

Quantum chemical modeling of enantioselective sulfoxidation and epoxidation reactions by indole monooxygenase VpIndA1.

Indole monooxygenases (IMOs) are enzymes from the family of Group E monooxygenases, requiring flavin adenine dinucleotide (FAD) for their activities. IMOs play important roles in both sulfoxidation and epoxidation reactions. The broad substrate range and high selectivity of IMOs make them promising biocatalytic tools for synthesizing chiral compounds. In the present study, quantum chemical calculations using the cluster approach were performed to investigate the reaction mechanism and the enantioselectivity of the IMO from Variovorax paradoxus EPS (VpIndA1). The sulfoxidation of methyl phenyl sulfide (MPS) and the epoxidation of indene were chosen as the representative reactions. The calculations confirmed that the FADOOH intermediate is the catalytic species in the VpIndA1 reactions. The oxidation of MPS adopts a one-step mechanism involving the direct oxygen-transfer from FADOOH to the substrate and the proton transfer from the -OH group back to FAD, while the oxidation of indene follows a stepwise mechanism involving a carbocation intermediate. It was computationally predicted that VpIndA1 prefers the formation of (S)-product for the MPS sulfoxidation and (1S,2R)-product for the indene epoxidation, consistent with the experimental observations. Importantly, the factors controlling the stereo-preference of the two reactions are identified. The findings in the present study provide valuable insights into the VpIndA1-catalyzed reactions, which are essential for the rational design of this enzyme and other IMOs for industrial applications. It is also worth emphasizing that the quantum chemical cluster approach is again demonstrated to be powerful in studying the enantioselectivity of enzymatic reactions.

Secondary Metabolites with Agricultural Antagonistic Potential from Aspergillus sp. ITBBc1, a Coral-Associated Marine Fungus.

A marine-derived fungal strain, Aspergillus sp. ITBBc1, was isolated from coral collected from the South China Sea in Hainan province. Intensive chemical investigation of the fermentation extract of this strain afforded four new secondary metabolites (1-4), named megastigmanones A-C and prenylterphenyllin H, along with four known compounds (5-8). Their structures were elucidated by extensive spectroscopic analysis including one-and two-dimensional (1D and 2D) NMR spectroscopy and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). The modified Mosher's method was undertaken to determine the absolute configurations of new compounds. The phytotoxic activity test showed that compounds 6-8 exhibited significant antagonistic activity against the germination of Triticum aestivum L. and Oryza sativa L. seeds with a dose-dependent relationship.

Bis-piperidine alkaloids from the peels of Areca catechu.

Four new alkaloids, arecatines A-D (1-4), were isolated from the peels of Areca catechu. Compound 1 is an unusual piperidine-pyridine hybrid alkaloid, whereas compounds 2-4 feature bis-piperidine alkaloids. Their structures were elucidated by UV, IR, HRESIMS, and NMR spectra analysis. The molecular docking analysis indicated that compound 3 exhibited the best binding affinity with the GABAA receptor, indicating its potential anti-epilepsy activity.

[Exploration of Application of Essential Principles of Safety and Performance of Medical Devices and IVD Medical Devices: Take Artificial Joint Products as Example].

Through the effective application of Essential Principles of Safety and Performance of Medical Devices and IVD Medical Devices (EP), to continuously improve the corresponding management tools to ensure the safety and effectiveness of medical device in the quality management system, risk management system, evaluation of safety and effectiveness for the supervision departments and manufacturers. The current status of the application of EP and the application issues are analyzed in the study. Take artificial joint products for example, the idea of using EP in quality management system, risk management system and evaluation of safety and effectiveness is investigated, and several thoughts are proposed. Supervision departments should strengthen the unified understanding of EP, develop requirements according to the classification of medical device，and refine specific execution requirements.

The volume regulated anion channel VRAC regulates NLRP3 inflammasome by modulating itaconate efflux and mitochondria function.

The NLRP3 inflammasome is a supramolecular complex that is linked to sterile and pathogen-dependent inflammation, and its excessive activation underlies many diseases. Ion flux disturbance and cell volume regulation are both reported to mediate NLRP3 inflammasome activation, but the underlying orchestrating signaling remains not fully elucidated. The volume-regulated anion channel (VRAC), formed by LRRC8 proteins, is an important constituent that controls cell volume by permeating chloride and organic osmolytes in response to cell swelling. We now demonstrate that Lrrc8a, the essential component of VRAC, plays a central and specific role in canonical NLRP3 inflammasome activation. Moreover, VRAC acts downstream of K+ efflux for NLRP3 stimuli that require K+ efflux. Mechanically, our data demonstrate that VRAC modulates itaconate efflux and damaged mitochondria production for NLRP3 inflammasome activation. Further in vivo experiments show mice with Lrrc8a deficiency in myeloid cells were protected from lipopolysaccharides (LPS)-induced endotoxic shock. Taken together, this work identifies VRAC as a key regulator of NLRP3 inflammasome and innate immunity by regulating mitochondrial adaption for macrophage activation and highlights VRAC as a prospective drug target for the treatment of NLRP3 inflammasome and itaconate related diseases.

First Report of Bronzing Disease Caused by Pantoea stewartii on Jackfruit in China.

Jackfruit (Artocarpus heterophyllus) is an important tropical commercial fruit crop grown in Hainan province, China. In recent years, severe jackfruit bronzing disease has been found in 11 cities and counties in Hainan. On average, 80% of trees in a jackfruit orchard are affected once bronzing disease is detected. The disease is characterized by yellow-orange to reddish discoloration of the pulp and rags of infected fruit (Hernández-Morales et al. 2017). Jackfruit bronzing disease has been reported previously in the Philippines (Gapasin et al. 2012), Malaysia (Zulperi et al. 2017), and Mexico (Hernández-Morales et al. 2017). Diseased samples of jackfruit 'Tai Eight' with the bronzing symptoms were collected from a plantation in Changjiang, Hainan. The samples were sterilized with 75% ethanol for 30 s, then soaked with 1% sodium hypochlorite for 8 min, and rinsed with sterilized distilled water. The sterilized tissues were ground in 2 mL sterile water, and allowed to stand for 30 min. Then, 500 µL of the supernatant was spread on Glucose-Yeast agar medium and incubated overnight at 28ºC. Representative bacterial colonies were lemon-yellow, convex and smooth, transparent with entire edges. Colonies were Gram-negative, positive for catalase and gelatin liquefaction, which were consistent with the characteristics of P. stewartii subsp. stewartii. In PCR amplifications, an 920 bp amplicon of strain JTPE2 with the primers ES16/ESIG2c (Coplin et al. 2002) and an 1100 bp amplicon of strain JTPC2 with the primers CPSL1/CPSR2c (Ibrahim et al. 2019) were obtained, whereas no bands were observed for the negative control samples. The ES16/ESIG2c and CPSL1/CPSR2c fragments were sequenced for nucleotide BLAST (BLASTn) searches of the NCBI database and phylogenetic tree construction. The obtained ES16/ESIG2c sequences (SAR accession no. SRR22405292) showed 99.07%-99.60% similarity with P. stewartii subsp. stewartii (CP017581, AJ311838 and MF598163). The obtained CPSL1/CPSR2c sequences (SAR accession no. SRR22405293) showed 99.40%-99.99% similarity with P. stewartii subsp. stewartii (MW971422, MH752485 and MH257287). Phylogenetic analysis based on cpsDE sequences (Ibrahim et al. 2019) using the maximum likelihood method revealed that strains JTPE2 and JTPC2 were clustered together with P. stewartii subsp. stewartii. A pathogenicity test was conducted by injecting 2 mL of 108 CFU/ml bacterial suspension into pulp from healthy, surface-sterilized jackfruit. Pulp injected with sterilized distilled water served as a negative control. All inoculated samples produced bronzing symptoms from 2-3 weeks post-inoculation similar to the field-observed symptoms, whereas control fruit were asymptomatic. The strains were reisolated from symptomatic jackfruit pulp to complete Koch's postulates. The bacterial suspension was inoculated on 2-week-old maize seedlings to supplement in vivo pathogenicity testing. Typical Stewart's disease leaf symptoms were visible at 2 weeks post-inoculation. Based on morphological, biochemical, and physiological evidence, pathogenicity tests, and molecular analyses, the pathogenic bacterium isolated from 'Tai Eight' jackfruit was identified as P. stewartii subsp. stewartii. To our knowledge, this is the first report of bronzing disease caused by P. stewartii subsp. stewartii on jackfruit in China, which may assist in preventing the global spread of jackfruit bronzing disease.

First Report of Bark Split Disease Caused by Pectobacterium carotovorum on Artocarpus heterophyllus (Jackfruit) in China.

Jackfruit (Artocarpus heterophyllus) is widely cultivated in the tropical areas in the world. Jackfruit bark split disease occurred in the large-scale plantations of 18 cities and counties surveyed in Hainan since 2021, among which the incidence rate of serious orchards reached about 70%, and the mortality rate reached about 35%. Jackfruit bark split disease mainly harms tree branches and trunks, manifested as water stains, bark gumming, bark depression, bark cracking, and ultimately plant death. To identify the pathogen, Four samples with jackfruit bark split disease symptoms were collected, sterilized with 75% ethanol for 30 s, then soaked in 2% sodium hypochlorite (NaClO) for 5 mins, and finally rinsed continuously with sterilized distilled water. The sterilized tissues were placed on LB agar medium and incubated in illumination incubator at 28 ℃. Four milky white, round with neat edges, convex and smooth, translucent colonies were obtained. All isolates (JLPs-1 to JLPs-4) were Gram-negative, negative for oxidase, catalase and gelatin liquefaction. Amplification and sequencing of 16S rDNA gene from 4 isolates were conducted with the universal primers 27f /1492r (Lane et al. 1991). The BLASTn analysis of obtained JLPs-1 and JLPs-3 sequences (GenBank accession nos. OP942452 and OP942453) showed an identity percentage of 98.99% and 98.93% with Pectobacterium sp. (CP104733), respectively. Phylogenetic analysis based on 16S rDNA gene using the neighbor-joining method with MEGA 7.0 software revealed that JLPs-1 and JLPs-3 were clustered together with P. carotovorum reference strains. The four housekeeping genes gyrA, recA, rpoA and rpoS were partially sequenced for JLPs-1 isolates using primers gyrA1/gyrA4, recA1/recA2c, rpoS1/rpoS2 and rpoA F1/rpoA R1 (Loc et al. 2022), respectively. Multilocus sequence analyses identified the isolates from jackfruit as P. carotovorum. To further confirm the identification of Pectobacterium carotovorum, pelY gene, P. carotovorum subsp. Brasiliensis 16S-23S intergenic region (Pcb IGS) and P. carotovorum subsp. carotovorum (Pcc) specific fragment were amplified with primers Y1/Y2 (Darrasse et al. 1994), BR1f/L1r (Duarte et al. 2004) and EXPCCF/EXPCCR (Kang et al. 2003), respectively. A 540 bp target fragment was successfully amplified from JTPs only by EXPCCF/EXPCCR and there no bands for the other two primers. Pathogenicity test was performed in the field, and all the inoculated trees were 2-3-year-old 'Qiong Yin No.1' variety. Dense small holes were pierced with sterilized inoculation needle on four healthy jackfruit trees. Then punctured wounds were spraying-inoculated with bacteria suspension of JLPs-1 (108 CFU/ml), and finally wrapped with plastic wrap to moisturize. Two trees inoculated with sterile distilled water served as negative control. Typical symptoms of bark gumming, bark depression, bark cracking were observed on all of the inoculated trees at 17 dpi which just similar to those originally caused by P. carotovorum in the field, whereas negative control trees remained asymptomatic. The strains were re-isolated successfully from symptomatic jackfruit trees and were consistent with the biological and molecular biological characteristics of original strains, confirming that the pathogen of jackfruit bark split disease was Pectobacterium carotovorum. To our knowledge, this is the first report of P. carotovorum causing bark split disease on jackfruit in China.

Natural Products and Biological Activity from Actinomycetes Associated with Marine Algae.

Marine natural products have been recognized as the most promising source of bioactive substances for drug discovery research. This review illustrates the diversity of culturable actinobacteria associated with marine algae, their bioactivity and metabolites, and approaches to their isolation and determination of their biological properties. Furthermore, actinobacteria associated with marine algae are presented as a new subject for an extensive investigation to find novel and active natural products, which make them a potentially rich and innovative source for new drug development deserving more attention and exploration.

New Isocoumarin and Pyrone Derivatives from the Chinese Mangrove Plant Rhizophora mangle-Associated Fungus Phomopsis sp. DHS-11.

Mangrove-associated fungi are important sources for the discovery of new bioactive natural products. Three new isocoumarins (1-3) and one new pyrone derivative (4) were isolated from the ethyl acetate extract of the fermentation broth of the mangrove endophytic fungus Phomopsis sp. DHS-11. Nuclear magnetic resonance (NMR) spectroscopy (one-dimensional and two-dimensional) and mass spectrometry were used to determine the structures of these new compounds. The absolute configurations for the new isocoumarins 1-3 were determined by comparing their experimental and calculated electronic circular dichroism (ECD) spectra, while the configuration for the new pyrone-derivative 4 was tentatively solved by comparison of its 13C NMR data with reported data. In the biological activity test, compounds 1 and 3 showed cytotoxic activity against HeLa cells with IC50 values of 11.49 ± 1.64 µM and 8.70 ± 0.94 µM, respectively. The initial structure and activity relationship (SAR) analysis revealed that the length of the side chain at C-3 for isocoumarin-type compounds 1-3 could affect the cytotoxicity against HeLa cells. Compound 4 exhibited cytotoxic activities against human hepatoma cells HepG2 with an IC50 value of 34.10 ± 2.92 µM. All compounds have no immunosuppressive activity.

The Protective Effect of (-)-Tetrahydroalstonine against OGD/R-Induced Neuronal Injury via Autophagy Regulation.

Here, (-)-Tetrahydroalstonine (THA) was isolated from Alstonia scholaris and investigated for its neuroprotective effect towards oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced neuronal damage. In this study, primary cortical neurons were pre-treated with THA and then subjected to OGD/R induction. The cell viability was tested by the MTT assay, and the states of the autophagy-lysosomal pathway and Akt/mTOR pathway were monitored by Western blot analysis. The findings suggested that THA administration increased the cell viability of OGD/R-induced cortical neurons. Autophagic activity and lysosomal dysfunction were found at the early stage of OGD/R, which were significantly ameliorated by THA treatment. Meanwhile, the protective effect of THA was significantly reversed by the lysosome inhibitor. Additionally, THA significantly activated the Akt/mTOR pathway, which was suppressed after OGD/R induction. In summary, THA exhibited promising protective effects against OGD/R-induced neuronal injury by autophagy regulation through the Akt/mTOR pathway.

Computational Study of the Peroxygenase Mechanism Catalyzed by Hemoglobin Dehaloperoxidase Involved in the Degradation of Chlorophenols.

The biochemical evidence showed that hemoglobin dehaloperoxidase (DHP B) from Amphitrite Ornata is a multifunctional hemoprotein that catalyzes both dehalogenation and hydroxylation of halophenols via the peroxidase and peroxygenase mechanism, respectively, which sets the basis for the degradation of halophenols. In the peroxygenase mechanism, the reaction was previously suggested to be triggered either by the hydrogen atom abstraction by the Fe═O center or by the proton abstraction by His55. To illuminate the peroxygenase mechanism of DHP B at the atomistic level, on the basis of the high-resolution crystal structure, computational models were constructed, and a series of quantum mechanical/molecular mechanical calculations have been performed. According to the calculation results, the pathway (Path a) initiated by the H-abstraction by the Fe═O center is feasible. In another pathway (Path b), His55 can abstract the proton from the hydroxyl group of the substrate (4-Cl-o-cresol) to initiate the reaction; however, its feasibility depends on the prior electron transfer from the substrate to the porphyrin group. The rate-limiting step of Path a is the OH-rebound, which corresponds to an energy barrier of 14.7 kcal/mol at the quartet state. His55 acts as an acid-base catalyst and directly involves in the catalysis. Our mutant study indicates that His55 can be replaced by other titratable residues. These findings may provide useful information for further understanding of the catalytic reaction of DHP B and for the design of enzymes in the degradation of pollutants, in particular, halophenols.

ML365 inhibits TWIK2 channel to block ATP-induced NLRP3 inflammasome.

Dysregulation of NLRP3 inflammasome results in uncontrolled inflammation, which participates in various chronic diseases. TWIK2 potassium channel mediates potassium efflux that has been reported to be an essential upstream mechanism for ATP-induced NLRP3 inflammasome activation. Thus, TWIK2 potassium channel could be a potential drug target for NLRP3-related inflammatory diseases. In the present study we investigated the effects of known K2P channel modulators on TWIK2 channel expressed in a heterologous system. In order to increase plasma membrane expression and thus TWIK2 currents, a mutant channel with three mutations (TWIK2I289A/L290A/Y308A) in the C-terminus was expressed in COS-7 cells. TWIK2 currents were assessed using whole-cell voltage-clamp recording. Among 6 known K2P channel modulators tested (DCPIB, quinine, fluoxetine, ML365, ML335, and TKDC), ML365 was the most potent TWIK2 channel blocker with an IC50 value of 4.07 ± 1.5 µM. Furthermore, ML365 selectively inhibited TWIK2 without affecting TWIK1 or THIK1 channels. We showed that ML365 (1, 5 µM) concentration-dependently inhibited ATP-induced NLRP3 inflammasome activation in LPS-primed murine BMDMs, whereas it did not affect nigericin-induced NLRP3, or non-canonical, AIM2 and NLRC4 inflammasomes activation. Knockdown of TWIK2 significantly impaired the inhibitory effect of ML365 on ATP-induced NLRP3 inflammasome activation. Moreover, we demonstrated that pre-administration of ML365 (1, 10, 25 mg/kg, ip) dose-dependently ameliorated LPS-induced endotoxic shock in mice. In a preliminary pharmacokinetic study conducted in rats, ML365 showed good absolute oral bioavailability with F value of 22.49%. In conclusion, ML365 provides a structural reference for future design of selective TWIK2 channel inhibitors in treating related inflammatory diseases.

Discovery of p-Terphenyl Metabolites as Potential Phosphodiesterase PDE4D Inhibitors from the Coral-Associated Fungus Aspergillus sp. ITBBc1.

Chemical investigation of the fermentation extract of the coral-associated fungus Aspergillus sp. ITBBc1 led to the discovery of five unreported p-terphenyl derivatives, sanshamycins A-E (1-5), together with five previously described analogues, terphenyllin (6), 3-hydroxyterphenyllin (7), candidusin A (8), 4,5-dimethoxycandidusin A (9), and candidusin C (10). Their structures were elucidated by HRESIMS data and NMR spectroscopic analysis. Compound 1 represents the first example of p-terphenyls with an aldehyde substitution on the benzene ring. Compounds 2-4 feature varying methoxyl and isopentenyl substitutions, while compound 5 features a five-membered lactone linked to a biphenyl. These findings expand the chemical diversity of the family of p-terphenyl natural products. Compounds 1-6 and 9 were evaluated for their inhibitory activity against type 4 phosphodiesterase (PDE4), which is a fascinating drug target for treatment of inflammatory, respiratory, and neurological diseases. Compound 3 was the most potent and exhibited PDE4D inhibitory activity with an IC50 value of 5.543 µM.

Unsupervised Deep Anomaly Detection for Medical Images Using an Improved Adversarial Autoencoder.

Anomaly detection has been applied in the various disease of medical practice, such as breast cancer, retinal, lung lesion, and skin disease. However, in real-world anomaly detection, there exist a large number of healthy samples, and but very few sick samples. To alleviate the problem of data imbalance in anomaly detection, this paper proposes an unsupervised learning method for deep anomaly detection based on an improved adversarial autoencoder, in which a module called chain of convolutional block (CCB) is employed instead of the conventional skip-connections used in adversarial autoencoder. Such CCB connections provide considerable advantages via direct connections, not only preserving both global and local information but also alleviating the problem of semantic disparity between the encoding features and the corresponding decoding features. The proposed method is thus able to capture the distribution of normal samples within both image space and latent vector space. By means of minimizing the reconstruction error within both spaces during training phase, higher reconstruction error during test phase is indicative of an anomaly. Our method is trained only on the healthy persons in order to learn the distribution of normal samples and can detect sick samples based on high deviation from the distribution of normality in an unsupervised way. Experimental results for multiple datasets from different fields demonstrate that the proposed method yields superior performance to state-of-the-art methods.

Aberrant Transferrin and Ferritin Upregulation Elicits Iron Accumulation and Oxidative Inflammaging Causing Ferroptosis and Undermines Estradiol Biosynthesis in Aging Rat Ovaries by Upregulating NF-Κb-Activated Inducible Nitric Oxide Synthase: First Demonstration of an Intricate Mechanism.

We report herein a novel mechanism, unraveled by proteomics and validated by in vitro and in vivo studies, of the aberrant aging-associated upregulation of ovarian transferrin and ferritin in rat ovaries. The ovarian mass and serum estradiol titer plummeted while the ovarian labile ferrous iron and total iron levels escalated with age in rats. Oxidative stress markers, such as nitrite/nitrate, 3-nitrotyrosine, and 4-hydroxy-2-nonenal, accumulated in the aging ovaries due to an aberrant upregulation of the ovarian transferrin, ferritin light/heavy chains, and iron regulatory protein 2(IRP2)-mediated transferrin receptor 1 (TfR1). Ferritin inhibited estradiol biosynthesis in ovarian granulosa cells in vitro via the upregulation of a nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and p65/p50-induced oxidative and inflammatory factor inducible nitric oxide synthase (iNOS). An in vivo study demonstrated how the age-associated activation of NF-κB induced the upregulation of iNOS and the tumor necrosis factor α (TNFα). The downregulation of the keap1-mediated nuclear factor erythroid 2-related factor 2 (Nrf2), that induced a decrease in glutathione peroxidase 4 (GPX4), was observed. The aberrant transferrin and ferritin upregulation triggered an iron accumulation via the upregulation of an IRP2-induced TfR1. This culminates in NF-κB-iNOS-mediated ovarian oxi-inflamm-aging and serum estradiol decrement in naturally aging rats. The iron accumulation and the effect on ferroptosis-related proteins including the GPX4, TfR1, Nrf2, Keap1, and ferritin heavy chain, as in testicular ferroptosis, indicated the triggering of ferroptosis. In young rats, an intraovarian injection of an adenovirus, which expressed iron regulatory proteins, upregulated the ovarian NF-κB/iNOS and downregulated the GPX4. These novel findings have contributed to a prompt translational research on the ovarian aging-associated iron metabolism and aging-associated ovarian diseases.

Isolation and Identification of Secondary Metabolites Produced by Phytopathogenic Fungus Corynespora cassiicola from Hevea brasiliensis.

The secondary metabolites of the phytopathogenic fungus Corynespora cassiicola CC01 from Hevea brasiliensis were investigated. As a result, two new compounds, 5-acetyl-7-hydroxy-6- methoxybenzofuran-2(3H)-one (1) and (S)-2-(2,3-dihydrofuro [3,2-c]pyridin-2-yl)propan-2-ol (2), together with seven known compounds, 4,6,8-trihydroxy-3,4-dihydronaphthalen-1(2H)-one (3), 3,6,8-trihydroxy-3,4-dihydronaphthalen-1(2H)-one (4), curvulin acid (5), 2-methyl-5-carboxymethyl- 7-hydroxychromone (6), tyrosol (7), p-hydroxybenzoic acid (8) and cerevisterol (9), were isolated from the fermentation extract by comprehensive silica gel, reverse phase silica gel, Sephadex-LH20 column chromatography and high-performance liquid chromatography (HPLC). The structures of these compounds were identified by using high-resolution electrospray mass spectrometry (HRESIMS), nuclear magnetic resonance spectroscopy (NMR), optical rotation, ultraviolet and infrared spectroscopy techniques and a comparison of NMR data with those reported in the literature. Compounds 1 and 2 were new compounds, and compounds 3-9 were discovered from this phytopathogenic fungus for the first time. Compounds 1-9 were tested for phytotoxicity against the fresh tender leaf of Hevea brasiliensis, and the results show that none of them were phytotoxic. Additionally, these compounds were subjected to an antimicrobial assay against three bacteria (E. coli, methicillin-resistant Staphylococcus aureus and Micrococcus luteus), but they showed no activity.

MicroRNA-21 promotes epithelial-mesenchymal transition and migration of human bronchial epithelial cells by targeting poly (ADP-ribose) polymerase-1 and activating PI3K/AKT signaling.

Epithelial-mesenchymal transition (EMT) is known to be involved in airway remodeling and fibrosis of bronchial asthma. However, the molecular mechanisms leading to EMT have yet to be fully clarified. The current study was designed to reveal the potential mechanism of microRNA-21 (miR-21) and poly (ADP-ribose) polymerase-1 (PARP-1) affecting EMT through the PI3K/AKT signaling pathway. Human bronchial epithelial cells (16HBE cells) were transfected with miR-21 mimics/inhibitors and PARP-1 plasmid/small interfering RNA (siRNA). A dual luciferase reporter assay and biotin-labeled RNA pull-down experiments were conducted to verify the targeting relationship between miR-21 mimics and PARP-1. The migration ability of 16HBE cells was evaluated by Transwell assay. Quantitative real-time polymerase chain reaction and Western blotting experiments were applied to determine the expression of Snail, ZEB1, E-cadherin, N-cadherin, Vimentin, and PARP-1. The effects of the PI3K inhibitor LY294002 on the migration of 16HBE cells and EMT were investigated. Overexpression of miR-21 mimics induced migration and EMT of 16HBE cells, which was significantly inhibited by overexpression of PARP-1. Our findings showed that PARP-1 was a direct target of miR-21, and that miR-21 targeted PARP-1 to promote migration and EMT of 16HBE cells through the PI3K/AKT signaling pathway. Using LY294002 to block PI3K/AKT signaling pathway resulted in a significant reduction in the migration and EMT of 16HBE cells. These results suggest that miR-21 promotes EMT and migration of HBE cells by targeting PARP-1. Additionally, the PI3K/AKT signaling pathway might be involved in this mechanism, which could indicate its usefulness as a therapeutic target for asthma.

Fibroblast transdifferentiation promotes conversion of M1 macrophages and replenishment of cardiac resident macrophages following cardiac injury in mice.

Resident cardiac macrophages play important roles in homeostasis, maintenance of cardiac function, and tissue repair. After cardiac injury, monocytes infiltrate the tissue, undergo phenotypic and functional changes, and are involved in inflammatory injury and functional remodelling. However, the fate of cardiac infiltrating/polarized macrophages and the relationship between these cells and resident cardiac macrophage replenishment following injury remain unclear. Our results showed that angiotensin II induces cardiac fibroblast transdifferentiation into cardiac myofibroblasts (MFBs). In cocultures with MFBs and murine macrophages, the MFBs promoted macrophage polarization to M1 phenotype, followed by selective apoptosis, which was associated with TNF/TNFR1 axis and independent of NO production. Surprisingly, after 36 h of coculture, the surviving macrophages were converted to M2 phenotype and settled in heart, which was dependent on leptin produced by MFBs or polarized macrophages via the PI3K or Akt pathway. CCR2+ CD45.2+ cells adoptively transferred into CD45.1+ mice with viral myocarditis, differentiated into CD45.2+ CCR2+ CX3CR1+ M2 cells during the resolution of inflammation and settled within the heart. Our data highlight a novel mechanism related to the renewal or replenishment of cardiac resident macrophages following cardiac injury; and suggest that transdifferentiation of cardiac fibroblasts may promote the resolution of inflammation.