The gp130/STAT3-endoplasmic reticulum stress axis regulates hepatocyte necroptosis in acute liver injury.

AIM: To investigate the effect of the gp130/STAT3-endoplasmic reticulum (ER) stress axis on hepatocyte necroptosis during acute liver injury. METHODS: ER stress and liver injury in LO2 cells were induced with thapsigargin, and in BALB/c mice with tunicamycin and carbon tetrachloride (CCl4). Glycoprotein 130 (gp130) expression, the degrees of ER stress, and hepatocyte necroptosis were assessed. RESULTS: ER stress significantly upregulated gp130 expression in LO2 cells and mouse livers. The silencing of activating transcription factor 6 (ATF6), but not of ATF4, increased hepatocyte necroptosis and mitigated gp130 expression in LO2 cells and mice. Gp130 silencing reduced the phosphorylation of CCl4-induced signal transducer and activator of transcription 3 (STAT3), and aggravated ER stress, necroptosis, and liver injury in mice. CONCLUSION: ATF6/gp130/STAT3 signaling attenuates necroptosis in hepatocytes through the negative regulation of ER stress during liver injury. Hepatocyte ATF6/gp130/STAT3 signaling may be used as a therapeutic target in acute liver injury.

Functional Endophytes Regulating Plant Secondary Metabolism: Current Status, Prospects and Applications.

Endophytes, which are widely found in host plants and have no harmful effects, are a vital biological resource. Plant endophytes promote plant growth and enhance plants' resistance to diseases, pests, and environmental stresses. In addition, they enhance the synthesis of important secondary metabolites in plants and improve the potential applicability of plants in agriculture, medicine, food, and horticulture. In this review, we summarize the recent progress in understanding the interaction between endophytes and plants and summarize the construction of synthetic microbial communities (SynComs) and metaomics analysis of the interaction between endophytes and plants. The application and development prospects of endophytes in agriculture, medicine, and other industries are also discussed to provide a reference for further study of the interaction between endophytes and plants and further development and utilization of endophytes.

Application of potential probiotic strain Streptomyces sp. SH5 on anti-Aeromonas infection in zebrafish larvae.

Pre-treatment of Streptomyces sp. SH5 on zebrafish lead to a significant enhancement of larvae survival upon Aeromonas hydrophila challenging. SH5 was able to colonize in zebrafish approximately at 1 × 102.6 cells per fish for at least seven days. The presence of SH5 strongly repelled the A. hydrophila colonization in zebrafish, and maximally, a 67.53% reduction rate was achieved. A more diversified flora was discovered in the SH5-treated zebrafish larvae at both phylum and genus levels. The expression of immune response genes of SH5-treated zebrafish, including TLR3, lysozyme and NOS2α, were enhanced at initial stage, while, that of various inflammatory stimuli genes including 1L-1ß, 1L-6 and MyD88 were decreased at all tested timepoints. SH5 was shown to inhibit virulence factors production and the expression of corresponding virulence genes in A. hydrophila, suggesting its quorum sensing inhibitory potential. These results indicated favorable application perspectives of SH5 in resisting pathogenic infection in aquaculture.

The transcriptional factor GATA-4 negatively regulates Hsp70 transcription in Crassostrea hongkongensis.

To better explore the application potential of heat shock protein Hsp70s in diverse areas including biomonitoring, a further investigation of the details of the regulatory mechanism governing Hsp70 transcription is required. A transcriptional factor ChGATA-4 that displayed affinity to the ChHsp70 promoter of Crassostrea hongkongensis was isolated and identified by DNA affinity purification as well as mass spectrometry analysis. The ChGATA-4 cDNA is 2162 bp in length and the open reading frame encodes a polypeptide containing 482 amino acids with a conserved zinc finger domain. The over-expression of ChGATA-4 significantly inhibited the expression of ChHsp70 promoter in heterologous HEK293T cells. However, the depletion of ChGATA-4 mRNA by RNAi technique resulted in significant increase of ChHsp70 transcription in oyster hemocytes. The RT-PCR results demonstrated that the transcription of both ChHsp70 and ChGATA-4 were induced by heat, Cd, or NP (Nonyl phenol) stress. This suggested a potential correlation between ChHsp70 and ChGATA-4 in the stress-mediated genetic regulatory cascade. This study demonstrated that ChGATA-4 acts in a negative manner in controlling ChHsp70 transcription in C. hongkongensis and promotes to further understand the mechanisms leading Hsp70 transcription.

Chemical constituents of Bletilla striata.

A new triphenanthrene compound named 2,2',2'',7,7',7''-hexahydroxy-4,4',4''-trimethoxy-[9,9',9'',10,10',10'']-hexahydro-1,8,1',6''-triphenanthrene (1), together with eleven known compounds (2－12), were isolated from tubers of Bletilla striata. Their structures were determined by analysis of spectroscopic data.

The transcriptional factor YB-1 positively regulates Hsc70 transcription in Crassostrea hongkongensis.

A Y-box binding protein ChYB-1 was discovered as a ChHsc70 promoter-associated protein in Crassostrea hongkongensis by DNA-affinity purification and mass spectrometry analysis. The overexpression of ChYB-1 in heterologous HEK293T cells led to clear enhancement of ChHsc70 promoter expression, while ChYB-1 depletion correlated with significant reduction of ChHsc70 transcription in the hemocytes of C. hongkongensis. Quantitative Real-time PCR analysis revealed that both ChHsc70 and ChYB-1 were transcriptionally responsive to external chemical or physical stressors. This indicates a plausible correlation between ChHsc70 and ChYB-1 in the genetic regulatory pathway triggered by external stresses. This study presents the first evidence of positive regulator for Hsc70 transcription and contributes to a better understanding of the regulatory mechanisms governing Hsc70 expression.

The guanine nucleotide-binding protein α subunit protein ChGnaq positively regulates Hsc70 transcription in Crassostrea hongkongensis.

Gnaq, one of Guanine nucleotide-binding protein α subunits, was isolated from cellular nucleus extracts of oyster Crassostrea hongkongensis gills with biotin-labeled ChHsc70 promoter by means of DNA-affinity purification, and preliminarily identified with mass spectrometry analysis. ChGnaq mRNA depletion by RNAi technique led to clear reduction in ChHsc70 mRNA expression of C. hongkongensis hemocytes. Correspondently, ChGnaq over-expression in heterologous HEK293T cells correlated with elevated expression activation of ChHsc70 promoter. Quantitative real time PCR analysis showed that both ChHsc70 and ChGnaq transcriptions were responsive to external physical/chemical stresses by heat, CdCl2 and NP. This suggested a plausible association between ChHsc70 and ChGnaq in the stress-induced genetic regulatory pathway. This study discovered a positively regulatory role of ChGnaq in controlling ChHsc70 transcription of C. hongkongensis, and conduced to a better understanding of the regulatory mechanisms in control of Hsc70 transcription.

Acetamiprid inhibits testosterone synthesis by affecting the mitochondrial function and cytoplasmic adenosine triphosphate production in rat Leydig cells.

The insecticide acetamiprid is used to control noxious agricultural pests. However, it can cause mammalian toxicity. We evaluated the reproductive toxicity of acetamiprid in adult male Sprague Dawley rats. Rats were given oral acetamiprid alone or with vitamin E for 35 days. Rat plasma testosterone concentration and sperm quality decreased significantly as the levels of luteinizing hormone (LH) increased after exposure. At the same time, acetamiprid increased malondialdehyde and nitric oxide (NO) levels of Leydig cells. Further analysis showed that acetamiprid reduced the adenosine triphosphate (ATP) and cyclic adenosine monophosphate (cAMP) production of Leydig cells, but the expression of luteinizing hormone/choriogonadotropin receptor (LHCGR) and the activity of adenylyl cyclase were not changed. Acetamiprid exposure also significantly diminished protein levels of steroidogenic acute regulatory protein (STAR), hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase cluster (HSD3B), and cytochrome P450, family 11, subfamily a, polypeptide 1 (CYP11A1), and testicular mRNA levels, which are cAMP-dependent proteins that are essential for steroidogenesis. Electron microscopy indicated mitochondrial membrane damage in the Leydig cells of the testes of exposed rats. Vitamin E ameliorated the impairment of acetamiprid on Leydig cells. Our results indicate that acetamiprid causes oxidative stress and mitochondrial damage in Leydig cells and inhibits the synthesis of testicular ATP and cAMP. Acetamiprid disrupts subsequent testosterone biosynthesis by decreasing the rate of conversion of cholesterol to testosterone and by preventing cholesterol from entering the mitochondria within the Leydig cells. These effects caused reproductive damage to the rats.

Three new 1-(p-hydroxybenzyl)phenanthrenes from Bletilla striata.

Three new benzylphenanthrenes, named 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2-ol (1), 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2,8-diol (2), and 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2,6-diol (3), along with a known analog were isolated from tubers of Bletilla striata. The structures of these new compounds were established by means of HR-ESI-MS, 1D, and 2D NMR.

High mobility group protein DSP1 negatively regulates HSP70 transcription in Crassostrea hongkongensis.

HSP70 acts mostly as a molecular chaperone and plays important roles in facilitating the folding of nascent peptides as well as the refolding or degradation of the denatured proteins. Under stressed conditions, the expression level of HSP70 is upregulated significantly and rapidly, as is known to be achieved by various regulatory factors controlling the transcriptional level. In this study, a high mobility group protein DSP1 was identified by DNA-affinity purification from the nuclear extracts of Crassostrea hongkongensis using the ChHSP70 promoter as a bait. The specific interaction between the prokaryotically expressed ChDSP1 and the FITC-labeled ChHSP70 promoter was confirmed by EMSA analysis. ChDSP1 was shown to negatively regulate ChHSP70 promoter expression by Luciferase Reporter Assay in the heterologous HEK293T cells. Both ChHSP70 and ChDSP1 transcriptions were induced by either thermal or CdCl2 stress, while the accumulated expression peaks of ChDSP1 were always slightly delayed when compared with that of ChHSP70. This indicates that ChDSP1 is involved, very likely to exert its suppressive role, in the recovery of the ChHSP70 expression from the induced level to its original state. This study is the first to report negative regulator of HSP70 gene transcription, and provides novel insights into the mechanisms controlling heat shock protein expression.

Identification of Novel Chromosomal Aberrations Induced by (60)Co-γ-Irradiation in Wheat-Dasypyrum villosum Lines.

Mutations induced by radiation are widely used for developing new varieties of plants. To better understand the frequency and pattern of irradiation-induced chromosomal rearrangements, we irradiated the dry seeds of Chinese Spring (CS)-Dasypyrum villosum nullisomic-tetrasomic (6A/6D) addition (6V) line (2n = 44), WD14, with (60)Co-γ-rays at dosages of 100, 200, and 300 Gy. The M0 and M1 generations were analyzed using Feulgen staining and non-denaturing fluorescence in situ hybridization (ND-FISH) by using oligonucleotide probes. Abnormal mitotic behavior and chromosomes with structural changes were observed in the M0 plants. In all, 39 M1 plants had structurally changed chromosomes, with the B genome showing the highest frequency of aberrations and tendency to recombine with chromosomes of the D genome. In addition, 19 M1 plants showed a variation in chromosome number. The frequency of chromosome loss was considerably higher for 6D than for the alien chromosome 6V, indicating that 6D is less stable after irradiation. Our findings suggested that the newly obtained γ-induced genetic materials might be beneficial for future wheat breeding programs and functional gene analyses.

Structure and regulatory targets of SCO3201, a highly promiscuous TetR-like regulator of Streptomyces coelicolor M145.

SCO3201, a regulator of the TetR family, is a strong repressor of both morphological differentiation and antibiotic production when overexpressed in Streptomyces coelicolor. Here, we report the identification of 14 novel putative regulatory targets of this regulator using in vitro formaldehyde cross-linking. Direct binding of purified His6-SCO3201 was demonstrated for the promoter regions of 5 regulators (SCO1716, SCO1950, SCO3367, SCO4009 and SCO5046), a putative histidine phosphatase (SCO1809), an acetyltransferase (SCO0988) and the polyketide synthase RedX (SCO5878), using EMSA. Reverse transcriptional analysis demonstrated that the expression of the transcriptional regulators SCO1950, SCO4009, SCO5046, as well as of SCO0988 and RedX was down regulated, upon SCO3201 overexpression, whereas the expression of SCO1809 and SCO3367 was up regulated. A consensus binding motif was derived via alignment of the promoter regions of the genes negatively regulated. The positions of the predicted operator sites were consistent with a direct repressive effect of SCO3201 on 5 out of 7 of these promoters. Furthermore, the 2.1Å crystal structure of SCO3201 was solved, which provides a possible explanation for the high promiscuity of this regulator that might account for its dramatic effect on the differentiation process of S. coelicolor.

Construction of full-length cDNA library and development of EST-derived simple sequence repeat (EST-SSR) markers in Senecio scandens.

Senecio scandens Buch.-Ham. ex D. Don (Compositae) is a crucial source of Chinese traditional medicine with antibacterial properties. We constructed a cDNA library and obtained expressed sequence tags (ESTs) to show the distribution of gene ontology annotations for mRNAs, using an individual plant with superior antibacterial characteristics. Analysis of comparative genomics indicates that the putative uncharacterized proteins (21.07%) might be derived from "molecular function unknown" clones or rare transcripts. Furthermore, the Compositae had high cross-species transferability of EST-derived simple sequence repeats (EST-SSR), based on valid amplifications of 206 primer pairs developed from the newly assembled expressed sequence tag sequences in Artemisia annua L. Among those EST-SSR markers, 52 primers showed polymorphic amplifications between individuals with contrasting diverse antibacterial traits. Our sequence data and molecular markers will be cost-effective tools for further studies such as genome annotation, molecular breeding, and novel transcript profiles within Compositae species.

Sequencing and comparative genomics analysis in Senecio scandens Buch.-Ham. Ex D. Don, based on full-length cDNA library.

Senecio scandens Buch.-Ham. ex D. Don, an important antibacterial source of Chinese traditional medicine, has a widespread distribution in a few ecological habitats of China. We generated a full-length complementary DNA (cDNA) library from a sample of elite individuals with superior antibacterial properties, with satisfactory parameters such as library storage (4.30 × 106 CFU), efficiency of titre (1.30 × 106 CFU/mL), transformation efficiency (96.35%), full-length ratio (64.00%) and redundancy ratio (3.28%). The BLASTN search revealed the facile formation of counterparts between the experimental sample and Arabidopsis thaliana in view of high-homology cDNA sequence (90.79%) with e-values <1e - 50. Sequence similarities to known proteins indicate that the entire sequences of the full-length cDNA clones consist of the major of functional genes identified by a large set of microarray data from the present experimental material. For other Compositae species, a large set of full-length cDNA clones reported in the present article will serve as a useful resource to facilitate further research on the transferability of expressed sequence tag-derived simple sequence repeats (EST-SSR) development, comparative genomics and novel transcript profiles.

Advances in militarine: Pharmacology, synthesis, molecular regulation and regulatory mechanisms.

Militarine is the lead member of secondary metabolites found in multiple medicinal plants of the orchid family. It acts as not only an important inhibitor on plant growth, but also functions as the quality marker for medicinal materials. In addition, Militarine has been shown to possess remarkably medicinal value, with a definite potential for finding widespread adoption of treating various diseases, including lung injury, brain nerve injury, cognitive impairment, aging, tumors, inflammation, peptic ulcers, and more. Thus, it can serve as a material carrier for pharmacophore upon, so much so that it probes as natural source of lead compounds in the research and development of medication. The study reported herein makes an overview on the physicochemical properties and pharmacological mechanisms of Militarine compounds, summarizes the biogenic pathways of Militarine and organically integrates the biological characteristics of Militarine with multiple omics techniques. Besides, this review also constructs a regulatory system for the biological accumulation of Militarine around its precursor compounds, characteristic gene elements, key enzymes, important metabolic products, and critical steps and links. Exceptionally, emphasis on the biosynthesis of Militarine under both abiotic and biotic stress, as well as an elaboration of the signaling pathways and critical regulatory mechanisms that govern the metabolic flow of Militarine have been represented accordingly in this paper. These findings are expected to provide reference schemes and theoretical foundations for acquiring high-quality resources of Militarine and advancing its large-scale industrial production, drug development, and clinical applications to comprehensively elucidate the biosynthetic and metabolic pathways.

Research overview on the genetic mechanism underlying the biosynthesis of polysaccharide in tuber plants.

Tuber plants are of great significance in the world as human food crops. Polysaccharides, important metabolites in tuber plants, also serve as a source of innovative drugs with significant pharmacological effects. These drugs are particularly known for their immunomodulation and antitumor properties. To fully exploit the potential value of tuber plant polysaccharides and establish a synthetic system for their targeted synthesis, it is crucial to dissect their metabolic processes and genetic regulatory mechanisms. In this article, we provide a comprehensive summary of the basic pathways involved in the synthesis of various types of tuber plant polysaccharides. We also outline the key research progress that has been made in this area in recent years. We classify the main types and functions of tuber plant polysaccharides and analyze the biosynthetic processes and genetic regulation mechanisms of key enzymes involved in the metabolic pathways of starch, cellulose, pectin, and fructan in tuber plants. We have identified hexokinase and glycosyltransferase as the key enzymes involved in the polysaccharide synthesis process. By elucidating the synthesis pathway of polysaccharides in tuber plants and understanding the underlying mechanism of action of key enzymes in the metabolic pathway, we can provide a theoretical framework for enhancing the yield of polysaccharides and other metabolites in plant culture cells. This will ultimately lead to increased production efficiency.

Molecular mechanism of miRNA mediated biosynthesis of secondary metabolites in medicinal plants.

Plant secondary metabolites are important raw materials for the pharmaceutical industry, and their biosynthetic processes are subject to diverse and precise regulation by miRNA. The identification of miRNA molecules in medicinal plants and exploration of their mechanisms not only contribute to a deeper understanding of the molecular genetic mechanisms of plant growth, development and resistance to stress, but also provide a theoretical basis for elucidating the pharmacological effects of authentic medicinal materials and constructing bioreactors for the synthesis of medicinal secondary metabolite components. This paper summarizes the research reports on the discovery of miRNA in medicinal plants and their regulatory mechanisms on the synthesis of secondary metabolites by searching the relevant literature in public databases. It summarizes the currently discovered miRNA and their functions in medicinal plants, and summarizes the molecular mechanisms regulating the synthesis and degradation of secondary metabolites. Furthermore, it provides a prospect for the research and development of medicinal plant miRNA. The compiled information contributes to a comprehensive understanding of the research progress on miRNA in medicinal plants and provides a reference for the industrial development of related secondary metabolite biosynthesis.

Activated DBP degradation and relevant signal transduction path via quorum sensing autoinducers in Streptomyces sp. SH5.

Microbe-mediated DBP (dibutyl phthalate) mineralization is acknowledged to be affected by diverse extracellular factors. However, little is known about the regulatory effects from quorum sensing (QS) signals. In this study, extracellularly applied QS signals A-like (hydroxymethyl dihydrofuran) was discovered to significantly enhance DBP degradation efficiency in Streptomyces sp. SH5. Monobutyl phthalate, protocatechuic acid and beta-ketoadipate were discovered as degradation intermediates by HPLC-TOF-MS/MS. Multi-omics analysis revealed the up-regulation of multiple hydrolases, transferases and decarboxylases that potentially contributed to A-like accelerated DBP degradation. Transcription of Orf2708, an orthologue of global transcriptional activator, was significantly induced by A-like. Orf2708 was demonstrated to interact specifically with the promoter of hydrolase orf2879 gene by EMSA, and the overexpression of orf2879 led to an enhanced DBP degradation in SH5. Taken together with the molecular docking studies showing the stability of ligand-receptor complex of A-like and its potential receptor Orf3712, a hierarchical regulatory cascade underlying the QS signal mediated DBP degradation was proposed as A-like/Orf3712 duplex formation, enhanced orf2708 expression and the downstream specific activation of hydrolase Orf2879. Our study presents the first evidence of GBLs-type promoted DBP degradation among bacteria, and the elucidated signal transduction path indicates a universal application potential of this activation strategy.

The role of sirtuin1 in liver injury: molecular mechanisms and novel therapeutic target.

Liver disease is a common and serious threat to human health. The progression of liver diseases is influenced by many physiologic processes, including oxidative stress, inflammation, bile acid metabolism, and autophagy. Various factors lead to the dysfunction of these processes and basing on the different pathogeny, pathology, clinical manifestation, and pathogenesis, liver diseases are grouped into different categories. Specifically, Sirtuin1 (SIRT1), a member of the sirtuin protein family, has been extensively studied in the context of liver injury in recent years and are confirmed the significant role in liver disease. SIRT1 has been found to play a critical role in regulating key processes in liver injury. Further, SIRT1 seems to cause divers outcomes in different types of liver diseases. Recent studies have showed some therapeutic strategies involving modulating SIRT1, which may bring a novel therapeutic target. To elucidate the mechanisms underlying the role of sirtuin1 in liver injury and its potentiality as a therapeutic target, this review outlines the key signaling pathways associated with sirtuin1 and liver injury, and discusses recent advances in therapeutic strategies targeting sirtuin1 in liver diseases.