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Myxobacteria are special bacteria with wide adaptability, which are rich sources of structurally diverse natural products with intriguing biological properties. Here, a gram-negative myxobacterium strain s54d21 T was isolated from the sediment of a wetland park in China using the Escherichia coli baiting method. Based on 16S rRNA gene sequence and genomic data, the strain was demonstrated to be a novel species of a rare genus Hyalangium , designated Hyalangium ruber sp. nov (type strain s54d21 T  = GDMCC 1.1945 T  = JCM 39263 T ). The subsequent chemical investigation of the strain s54d21 T led to the isolation of three rare 3,5,6-trisubstituted 2(1 H )-pyrazinones, namely, hyalanones A-C ( 1 - 3 ), together with a known macrolactin A ( 4 ). Those new structures and their absolute configurations were unambiguously assigned by extensive analyses of spectroscopic data and density functional theory (DFT) calculations. In biological assays, compound 4 exhibited moderate cytotoxic activities against human cell lines RKO, A549, and NCM460 with IC 50 values ranging from 27.21 to 32.14  μ M., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zang, Zhang, Wang, Tong, Zhou, Yao and Zhu.)

Extracellular enzymes play important roles in myxobacteria degrading macromolecules and preying on other microorganisms. Glycoside hydrolases 19 (GH19) are widely present in myxobacteria, but their evolution and biological functions have not been fully elucidated. Here we investigated the comparative secretory proteome of Corallococcus silvisoli c25j21 in the presence of cellulose and chitin. A total of 313 proteins were detected, including 16 carbohydrate-active enzymes (CAZymes), 7 of which were induced by cellulose or chitin, such as GH6, GH13, GH19, AA4, and CBM56. We further analyzed the sequence and structural characteristics of its three GH19 enzymes to understand their potential functions. The results revealed that myxobacterial GH19 enzymes are evolutionarily divided into two clades with different appended modules, and their different amino acid compositions in the substrate binding pockets lead to the differences in molecular surface electrostatic potentials, which may, in turn, affect their substrate selectivity and biological functions. Our study is helpful for further understanding the biological functions and catalytic mechanisms of myxobacterial CAZymes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhou, Zhou, Zhang, Dong, Dong and Zhu.)

Macrophage migration inhibitory factor (MIF), a multifunctional cytokine, is secreted by various cells and participates in inflammatory reactions, including innate and adaptive immunity. There are some evidences that MIF is involved in many vitreoretinal diseases. For example, MIF can exacerbate many types of uveitis; measurements of MIF levels can be used to monitor the effectiveness of uveitis treatment. MIF also alleviates trauma-induced and glaucoma-induced optic nerve damage. Furthermore, MIF is critical for retinal/choroidal neovascularization, especially complex neovascularization. MIF exacerbates retinal degeneration; thus, anti-MIF therapy may help to mitigate retinal degeneration. MIF protects uveal melanoma from attacks by natural killer cells. The mechanism underlying the effects of MIF in these diseases has been demonstrated: it binds to cluster of differentiation 74, inhibits the c-Jun N-terminal kinase pathway, and triggers mitogen-activated protein kinases, extracellular signal-regulated kinase-1/2, and the phosphoinositide-3-kinase/Akt pathway. MIF also upregulates Toll-like receptor 4 and activates the nuclear factor kappa-B signaling pathway. This review focuses on the structure and function of MIF and its receptors, including the effects of MIF on uveal inflammation, retinal degeneration, optic neuropathy, retinal/choroidal neovascularization, and uveal melanoma., Competing Interests: None

Instruction: Citrus is a globally important fruit tree whose microbiome plays a vital role in its growth, adaptability, and resistance to stress., Methods: With the high throughput sequencing of 16S rRNA genes, this study focused on analyzing the bacterial community, especially in the leaf midribs, of healthy and Huanglongbing (HLB)-infected plants., Results: We firstly identified the shared bacterial taxa in the midribs of both healthy and HLB-infected plants, and then analyzed their functions. Results showed that the shared bacterial taxa in midribs belonged to 62 genera, with approximately 1/3 of which modified in the infected samples. Furthermore, 366 metabolic pathways, 5851 proteins, and 1833 enzymes in the shared taxa were predicted. Among these, three metabolic pathways and one protein showed significant importance in HLB infection. With the random forest method, six genera were identified to be significantly important for HLB infection. Notably, four of these genera were also among the significantly different shared taxa. Further functional characterization of these four genera revealed that Pseudomonas and Erwinia likely contributed to plant defense against HLB, while Streptomyces might have implications for plant defense against HLB or the pathogenicity of Candidatus Liberibacter asiaticus (CLas)., Disccusion: Overall, our study highlights that the functions of the shared taxa in leaf midribs are distinguished between healthy and HLB-infected plants, and these microbiome-based findings can contribute to the management and protection of citrus crops against CLas., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Xia, Feng, Zhang, Zhou, Zhu and Yao.)

Four Gram-staining-negative, aerobic, yellow-pigmented and rod-shaped bacteria, named strains BD1B2-1 T , NT2B1 T , YF14B1 and DM2B3-1, were isolated from four rhizosphere soil samples of banana in China. Comparison of the 16S rRNA gene sequences showed that all these strains were most closely related to an invalidly published species, 'Rhodocytophaga rosea' 172606-1, with similarities ranging from 87.7 to 88.0%. According to the phylogenomic analysis, the four strains were clustered in an independent lineage and closely related to the genus Rhodocytophaga. The genomic sizes of these strains were approximately 9.49-9.77 Mbp with the DNA G + C contents of 38.8-39.0 mol%. They all contained C 16:1 ω5c, iso-C 15:0 and iso-C 17:0 3-OH as the major fatty acids and menaquinone 7 as the only respiratory quinone. They all had phosphatidylethanolamine as the major polar lipids. Based on phenotypic and phylogenomic characteristics, the four strains should represent two novel species within a novel genus, for which the names Xanthocytophaga agilis gen. nov., sp. nov. (BD1B2-1 T  = GDMCC 1.2890 T  = JCM 35374 T ) and Xanthocytophaga flavus sp. nov. (NT2B1 T  = GDMCC 1.2889 T  = JCM 35375 T ) are proposed; the former is assigned as the type species of the novel genus Xanthocytophaga gen. nov. In addition, based on the phenotypic and phylogenomic data, we proposed to reclassify the existing genus Rhodocytophaga in the family Cytophagaceae into a novel family Rhodocytophagaceae fam. nov. The novel family consists of the type genus Rhodocytophaga and the novel genus Xanthocytophaga., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Four novel bacterial strains, designated RBB1W86 T , RXD159 T , RBB189 T and RLT163 T , were isolated from subtropical forest soil of the Nanling National Nature Reserve located in Guangdong Province, PR China. 16S rRNA gene phylogeny indicated their affiliation to the genus Dyella , among which strains RBB1W86 T and RXD159 T were closely related to Dyella halodurans CGMCC 1.15435 T with 16S rRNA gene sequence similarities of 98.8 and 99.5 %, respectively, and strains RBB189 T and RLT163 T were closely related to Dyella tabacisoli CGMCC 1.16273 T (98.8 %) and Dyella japonica JCM 21530 T (99.4 %), respectively. Phylogenomic analysis based on 92 core genes showed consistent phylogeny with the 16S rRNA gene phylogeny for strains RBB1W86 T , RBB189 T and RLT163 T , while strain RXD159 T showed a closer relationship with D. tabacisoli CGMCC 1.16273 T and strain RBB189 T . The genome-derived average nucleotide identity (ANI) values between the newly isolated strains and their closely related species were 70.18‒90.20 %, and the corresponding digital DNA-DNA hybridization (dDDH) values were 20.80‒40.30 %. Meanwhile, the ANI and dDDH values between each pair of the newly isolated strains were 75.80‒79.77 % and 21.30‒23.30 %, respectively. They all took iso-C 15 : 0 and summed feature 9 (10-methyl C 16  : 0 and/or iso-C 17  : 1 ω 9 c ) as the major fatty acids. Moreover, C 16 : 0 , iso-C 16 : 0 , iso-C 17 : 0 and summed feature 3 (C 16 : 1 ω 7 c and/or C 16 : 1 ω 6 c ) were also variously distributed as major components. They all took ubiquinone 8 as the only predominant respiratory quinone and phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid as the major polar lipids. Phosphatidylmethylethanolamine was only present in strain RBB189 T as another major component. Based on the results of phenotypic, genotypic and chemotaxonomic analyses, the newly isolated strains could be clearly distinguished from their closely related species and should represent four distinct novel species of the genus Dyella , for which the names Dyella humicola sp. nov. (type strain RBB1W86 T =GDMCC 1.1901 T =KACC 21988 T ), Dyella subtropica sp. nov. (type strain RXD159 T =GDMCC 1.1902 T =KACC 21989 T ), Dyella silvatica sp. nov. (type strain RBB189 T =GDMCC 1.1900 T =KACC 21990 T ) and Dyella silvae sp. nov. (type strain RLT163 T =GDMCC 1.1916 T =KACC 21991 T ) are proposed.

A Gram-staining-negative, aerobic, and rod-shaped with tapered end myxobacterium, designed as strain H56D21 T , was isolated from forest soil sampled from the Diaoluo Mountain National Nature Reserve located in Hainan Province, PR China. It showed prey ability on two kinds of phytopathogens including both fungi (Fusarium solani, Fusarium graminearum, and Fusarium oxysporum) and bacteria (Ralstonia solanacearum and Xanthomonas campestris). Phylogenetic analyses based on the 16S rRNA gene and core genes  sequences revealed that strain H56D21 T belonged to the genus Hyalangium and was most closely related to Cystobacter gracilis DSM 14753  T and Hyalangium minutum DSM 14724  T . Genome comparison showed 85.6% and 82.3% of average nucleotide identity between strain H56D21 T and the above two type strains and 29.8% and 25.1% of digital DNA-DNA hybridization , respectively. The novel strain had a large genome size of 13.56 Mbp and a high  DNA G + C content of 67.1%. Genome annotation identified 46 secondary metabolite biosynthesis gene clusters and 187 CAZymes-encoding genes. The major fatty acids contained iso-C 15:0 , iso-C 15:0 DMA, C 16:1 ω5c, and iso-C 17:0 . The dominant respiratory quinone was menaquinone 8. Based on the phenotypic, chemotaxonomic and phylogenetic analyses, we suggested that strain H56D21 T should represent a novel species of the genus Hyalangium with a proposed name of Hyalangium versicolor sp. nov. (type strain H56D21 T  = GDMCC 1.1944  T  = KCTC 82613  T ) and Cystobacter gracilis should be reclassified as Hyalangium gracile comb. nov., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Two Gram-staining-negative, aerobic and rod-shaped strains, designated c23x22 T and sex2 T , were isolated from forest soil collected from Chebaling National Nature Reserve in Guangdong Province and Limu Mountain National Forest Park in Hainan Province, P. R. China, respectively. Phylogenetic analyses based on 16S rRNA gene sequences revealed that they belonged to the genus Microvirga, and strain c23 x22 T was most closely related to 'Microvirga alba' KCTC 72385, while strain sex2 T showed close relationship with Microvirga guangxiensis CGMCC 1.7666 T . The average nucleotide identity and digital DNA-DNA hybridization values between strains c23 x22 T and sex2 T and their close relatives, 'M. alba' KCTC 72385 and M. guangxiensis CGMCC 1.7666 T , were all below the threshold values for species delimitation. The predominant quinones of the two novel strains were ubiquinone 10, and the major fatty acids contained C 19:0 cyclo ω8c and summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c). Their predominant polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The phenotypic, genotypic and chemotaxonomic analyses clearly supported that strains c23 x 22 T and sex2 T represent two novel species of the genus Microvirga, for which the name Microvirga terricola sp. nov. (type strain c23 x 22 T  = GDMCC 1.1700 T  = KCTC 62432 T ) and Microvirga solisilvae sp. nov. (type strain sex2 T  = GDMCC 1.1651 T  = KACC 21311 T ) are proposed, respectively., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Myxobacteria, as predatory bacteria, have good application potential in the biocontrol of pathogenic microorganisms. Extracellular enzymes are thought to play an important role in their predation and also provide resources for discovering new antibacterial molecules. We previously isolated a myxobacterium, Corallococcus silvisoli c25j21 GDMCC 1.1387, which is predatory to plant pathogenic bacteria. In this study, we identified an endolysin-like GH19 glycoside hydrolase, C25GH19B, from the genome of c25j21. After its heterologous expression and purification from E. coli, the enzymatic properties of C25GH19B were characterized. C25GH19B showed lysozyme activity with the optimal reaction conditions at 40 °C and pH 4.5-5.0. Moreover, C25GH19B showed bacteriolytic activity against both Gram-positive and Gram-negative plant pathogenic bacteria. Our research provides not only a candidate enzyme for the development of novel biocontrol agents but also an experimental basis for further study on the function and mechanisms of extracellular enzymes in myxobacterial predation., (© 2022. The Author(s).)

Rapid and accurate strain identification of the most closely related genera Myxococcus , Corallococcus , and Pyxidicoccus can enhance the efficiency of the mining of novel secondary metabolites through dereplication. However, the commonly used 16S rRNA gene sequencing cannot accurately differentiate members of the three genera above, and the whole-genome sequencing is unable to rapidly and inexpensively provide species assignation toward a large number of isolates. To overcome the limitations, the gyrB gene was investigated as a candidate genetic marker for exploring the phylogenetic relationships of bacteria within the three genera and for developing the gyrB -based typing method. Here, the bacterial phylogeny and species affiliations of the three genera were determined based on the phylogenomic reconstruction and the analysis of digital DNA-DNA hybridization values among 90 genomes, further confirming nine novel taxa and assigning over one-third of genomes to defined species. The phylogenetic relationships of these strains based on the gyrB gene sequences were congruent with those based on their genome sequences, allowing the use of the gyrB gene as a molecular marker. The gyrB gene-specific primers for the PCR-amplification and sequencing of bacteria within the three genera were designed and validated for 31 isolates from our group collection. The gyrB -based taxonomic tool proved to be able to differentiate closely related isolates at the species level. Based on the newly proposed 98.6% identity threshold for the 966-bp gyrB gene and the phylogenetic inference, these isolates were assigned into two known species and eight additional putative new species. In summary, this report demonstrated that the gyrB gene is a powerful phylogenetic marker for taxonomy and phylogeny of bacteria within the closely related genera Myxococcus , Corallococcus , and Pyxidicoccus , particularly in the case of hundreds or thousands of isolates in environmental studies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Liu, Pei, Yi, Du, Zhang, Deng, Yao, Deng and Zhu.)

Three aerobic, Gram-stain-negative, non-motile and rod-shaped bacteria, designated strains RXD178 T , RXD172-2 and RLT1W51 T , were isolated from two forest soil samples of Nanling National Nature Reserve in Guangdong Province, PR China. Phylogenetic analyses based on 16S rRNA gene sequences and 92 core genes showed that they belonged to the genus Collimonas , and were most closely related to four validly published species with similarities ranging from 99.4 to 98.2 %. The genomic DNA G+C contents of strains RXD178 T , RXD172-2 and RLT1W51 T were 57.1, 59.5 and 59.4 mol%, respectively. The genome-derived average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the novel strains and closely related type species were below 37.90 and 89.34 %, respectively. Meanwhile, the ANI and dDDH values between strains RXD172-2 and RLT1W51 T were 98.27 and 83.50 %, respectively. The three novel strains contained C 16 : 0 , C 17 : 0 cyclo and summed feature 3 (C 16 : 1 ω 6 c and/or C 16 : 1 ω 7 c ) as the major fatty acids, and summed feature 8 (C 18 : 1 ω 6 c and/or C 18 : 1 ω 7 c ) comprised a relative higher proportion in strain RXD178 T than in other strains. Both strains RXD172-2 and RLT1W51 T had phosphatidylglycerol (PG), phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG) and an unidentified aminophospholipid (APL) as the main polar lipids while only PE and APL were detected in strain RXD178 T . Ubiquinone 8 was the predominant quinone. Based on the phenotypic, chemotaxonomic, phylogenetic and genomic analyses, strain RXD178 T should be considered as representing one novel species within the genus Collimonas and strains RXD172-2 and RLT1W51 T as another one, for which the names Collimonas silvisoli sp. nov. and Collimonas humicola sp. nov. are proposed, with RXD178 T (=GDMCC 1.1925 T =KACC 21987 T ) and RLT1W51 T (=GDMCC 1.1923 T =KACC 21985 T ) as the type strains, respectively.

Myxobacteria are abundant micropredators in soil, and are social bacteria with multicellular behavior and producers of versatile secondary metabolites. The interaction between predator and prey populations is an important component in the soil microbial food web, and this is expected to shape the composition and dynamics of microbial communities. Here we hypothesize the regulation of bacterial abundance and community composition on soil myxobacterial community. Field investigation indicated that the relative abundance of Myxococcales in subtropical and tropical forest soil from South China was 1.49-4.74% of all the 16S rRNA gene sequences, and myxobacterial community composition differed between subtropical and tropical forest. The canonical correspondence analysis and variation partitioning analysis indicated that biotic factor (bacterial community composition) showed slightly stronger explanation for variation of myxobacteria than soil properties (soil pH and soil organic matter). Based on the rhizosphere bacterial network, the greenhouse mesocosm experiment showed that most of the myxobacterial links were with Gram-negative bacteria, except that some nodes from Haliangiacea and Polyangiaceae interacted with actinomycetes and actinomycetes-like Gram-positive bacteria. We inferred that myxobacteria preferential predation on specific bacterial taxa may explain the influence of bacteria on myxobacterial community. Further study confirming the biological process of myxobacterial predation in situ is necessary to advance the understanding of the ecological role of predation behavior in the microbial world.

Apigenin (Api) is a plant monomer associated with reducing the risk of heart disease. However, the mechanism of action remains to be fully elucidated. In the present study, it was hypothesized that API has cardioprotective effects by attenuating myocardial ischemia/reperfusion (I/R) injury. Rats were randomly subjected to sham operation, myocardial I/R alone or I/R + Api. Cardiac function was measured, and infarct size was evaluated by triphenyltetrazolium chloride staining following reperfusion. The myocardial enzyme leakage was analyzed for lactate dehydrogenase (LDH) and creatine kinase (CK). The myocardium was also assessed for total superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The phosphorylation of p38 mitogen‑activated protein kinase (MAPK) was analyzed by western blotting. The present study reported for the first time, to the best of our knowledge, that I/R significantly increased infarct size, induced CK and LDH release, inhibited the activity of SOD and increased the levels of MDA, all of which were prevented by treatment with Api. In addition, I/R increased the phosphorylation of p38 MAPK, which was significantly decreased in the Api‑treated heart tissue samples following I/R, compared with the untreated heart tissue samples. In conclusion, the results of the present study demonstrated that Api inhibited the p38 MAPK signaling pathway to protect cardiomyocytes from I/R‑induced injury.

Retinopathy of prematurity (ROP) is a major and leading cause of blindness in premature infants. It has been realized that early treatment for ROP is important. However, all the early treatments of ROP are focusing on peripheral retinal ablation which does not surmount the limit of extinguishing retinal neovascularization and protecting the retinas of children with ROP from the injury of ablation. In this study, we investigated the morphological changes of retina and oxidative stress alterations in the early phase of oxygen-induced retinopathy (OIR) and tested the effects of 17β-estradiol (17β-E2), a nonselective estrogen receptor (ER) agonist, on early phase OIR development. We found that large central capillary-free areas were induced in the retinas of pups exposed to hyperoxia on postnatal day 9 (P9), whereas vascularization was almost complete in the retinas of pups exposed to normoxia at the same age. The concentrations of malondiadehyde (MDA), an end-product of oxidative stress, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, a major enzyme producing free radicals, as well as the activity of NADPH oxidase were significantly elevated in the retinas of pups exposed to hyperoxia on P9 and postnatal day 13 (P13) compared to those in age matched pups exposed to normoxia. Treatment with 17β-E2 decreased not only the percentage of the central capillary-free area to total retina area but also the concentrations of MDA and NADPH oxidase as well as the activity of NADPH oxidase in a dose-dependent manner in pups exposed to hyperoxia on p9 and P13. The concentration of VEGF was significantly decreased on P9 but increased on P14 in the retinas of pups exposed to hyperoxia, whereas it was significantly elevated on P9 but decreased on P14 in the retinas of pups treated with 17β-E2. The effect of 17β-E2 could be reversed by the co-treatment with ICI182780, a high affinity estrogen receptor antagonist, which suggested that 17β-E2 might exert its effect on early hyperoxic phase of OIR through estrogen receptor. Our results suggest that treatment with antioxidant drugs at early hyperoxic phase of ROP even before the appearance of retinal neovascularization may be more effective than their application to ROP at late phase, which may abolish the deleterious factors that contribute to retinal neovascularization and promote retinal blood vessels to develop healthily., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Fifty-eight terrestrial and salt-tolerant myxobacteria were isolated from the saline-alkaline soils collected from Xinjiang, China. Based on the morphologies and the 16S rRNA gene sequences, these isolates were assigned into 6 genera, Myxococcus, Cystobacter, Corallococcus, Sorangium, Nannocystis and Polyangium. All the strains grew better with 1% NaCl than without NaCl. Some Myxococcus strains were able to grow at 2% NaCl concentration, suggesting that these strains may be particular type of terrestrial myxobacteria.

Objective: We isolated myxobacteria and explored their diversity from the rhizosphere soils of some medicinal plants., Methods: We used the helper bacteria baiting technique to isolate myxobacteria from the rhizosphere soils collected in South China Botanical Garden and Nanling National Forest Park. The myxobacteria were identified by morphological characteristics and 16S rDNA gene sequences analysis., Results: A total of 50 strains were isolated from 22 soil samples, which were identified into 7 genera, Myxococcus (18), Corallococcus (11), Cystobacter (7), Archangium (8), Stigmatella (1), Chondromyces (4) and Pyxidicoccus (1). The dominant genera were Myxococcus and Corallococcus., Conclusion: Environmental factors were associated with the diversity of myxobactria. Myxobacteria better adapt in high organic matter content and neutral pH environments. The strains of Myxococcus and Corallococcus had a good adaptability for different pH. Meanwhile, the dependence of the strains of Myxococcus and Cystobacter on organic carbon content was not too obvious, and they can also be found in the poor soils. Our findings provided an important scientific base for the development and utilization of myxobacteria resources.

Objective: We isolated myxobacteria in saline-alkaline soils of Xinjiang using a prey-predator strategy where the prey bacteria can induce the predator myxobacteria to form visible fruiting body, and evaluated intrinsic relationships between prey and predator myxobacteria., Methods: Sixteen bacteria with inductive effects of fruiting body formation were obtained, and then used as preys to isolate the myxobacteria., Results: A total of 55 myxobacteria strains were isolated from 25 soil samples, which were identified to the genera of Myxococcus, Corallococcus, Pyxidicoccus, Cystobacter, and Nannocystis. Besides, 6 unpurified isolates were believed to be myxobacteria. All the 16 prey bacteria had preferable inductive effects on Myxococcus spp., whereas Pyxidicoccus spp. and Cystobacter spp. were only induced by Gram-positive strains., Conclusion: The prey-predator strategy provided a new and more effective way to isolate myxobacteria.

Baicalin has been demonstrated to exert anticancer effects mainly through induction of tumor cell apoptosis and cell cycle arrest. However, the precise mechanisms underlying its anticancer role remain to be elucidated. In the present study, we investigated whether autophagy was involved in the anticancer activity of baicalin in the human hepatocellular carcinoma (HCC) cell line SMMC-7721 and the possible molecular mechanisms. Our data showed that the viability of SMMC-7721 cells was significantly inhibited by baicalin in a dose- and time-dependent manner. Alongside apoptosis, autophagy was also induced by baicalin dose- and time-dependently with the involvement of the autophagy-associated protein Βeclin 1. Moreover, we demonstrated that cell death induced by baicalin was significantly inhibited by the apoptosis inhibitor z-DEVD-fmk or the autophagy inhibitor 3-MA, respectively. In addition, we found that CD147, a key molecule related both to apoptosis and autophagy, was markedly downregulated at the protein level in SMMC-7721 cells treated with baicalin. Collectively, this is the first study to suggest that baicalin induces autophagic cell death in SMMC-7721 cells, which involves the downregulation of CD147. Our study reveals a new mechanism for the anticancer effects of baicalin and puts forward a potential crucial role of CD147 in baicalin-induced cancer cell death.

Objective: To isolate myxobacteria and investigate their diversity in saline-alkaline soils from Akesu in Xinjiang., Methods: Conventional culture-dependent methods, e. g. baiting technique, water agar, soil extract agar and mineral agar, were used to isolate myxobacteria from 25 soil samples collected from Akesu areas of Xinjiang. Combining with physicochemical properties (acidity/alkalinity, salt concentration, vegetation and geographical locations) of the soil samples, myxobacterial diversity was studied., Results: In total 58 strains were isolated, and identified as belonging to 6 different genera, i.e. Myxococcus, Cystobacter, Corallococcus, Sorangium, Nannocystis and Polyangium of Myxococcales. The most frequent genus isolated was Myxococcus which may better adapt in harsh environments. Different myxobacterial diversity was detected in different habitat., Conclusion: Myxobacteria diversity was low in saline-alkaline soils of Akesu in Xinjiang.