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Hirudin, an acidic polypeptide secreted by the salivary glands of Hirudo medicinalis (also known as “Shuizhi” in traditional Chinese medicine), is the strongest natural specific inhibitor of thrombin found so far. Hirudin has been demonstrated to possess potent anti-thrombotic effect in previous studies. Recently, increasing researches have focused on the anti-thrombotic activity of the derivatives of hirudin, mainly because these derivatives have stronger antithrombotic activity and lower bleeding risk. Additionally, various bioactivities of hirudin have been reported as well, including wound repair effect, anti-fibrosis effect, effect on diabetic complications, anti-tumor effect, anti-hyperuricemia effect, effect on cerebral hemorrhage, and others. Therefore, by collecting and summarizing publications from the recent two decades, the pharmacological activities, pharmacokinetics, novel preparations and derivatives, as well as toxicity of hirudin were systematically reviewed in this paper. In addition, the clinical application, the underlying mechanisms of pharmacological effects, the dose-effect relationship, and the development potential in new drug research of hirudin were discussed on the purpose of providing new ideas for application of hirudin in treating related diseases.

Hypervirulent Klebsiella pneumoniae (hvKP) is an evolving infectious pathogen associated with high mortality. The convergence of hypervirulence and multidrug resistance further challenges the clinical treatment options for K. pneumoniae infections. The QseBC two-component system (TCS) is a component of quorum-sensing regulatory cascade and functions as a global regulator of biofilm growth, bacterial motility, and virulence in Escherichia coli. However, the functional mechanisms of QseBC in hvKP have not been reported, and we aim to examine the role of QseBC in regulating virulence in hvKP strain ATCC43816. The CRISPR-Cas9 system was used to construct qseB , qseC , and qseBC knockout in ATCC43816. No significant alterations in the growth and antibiotic susceptibility were detected between wild-type and mutants. The deletion of qseC led to an increase of biofilm formation, resistance to serum killing, and high mortality in the G. mellonella model. RNAseq differential gene expression analysis exhibited that gene-associated biofilm formation (glgC, glgP, glgA, gcvA, bcsA, ydaM, paaF, ptsG), bacterial type VI secretion system (virB4, virB6, virB10, vgrG, hcp), and biosynthesis of siderophore (entC, entD, entE) were significantly upregulated in comparison with the wild-type control. In addition, qseB , ygiW (encode OB-family protein), and AraC family transcriptional regulator IT767_23090 genes showed highest expressions in the absence of QseC, which might be related to increased virulence. The study provided new insights into the functional importance of QseBC in regulating the virulence of hvKP. [ABSTRACT FROM AUTHOR]

Aconitine is one of the main bioactive and toxic ingredients of Aconitum species. Increasingly, aconitine has been reported to induce neurotoxicity. However, whether aconitine has effects on the dopaminergic nervous system remains unclear. In this study, zebrafish embryos at 6-days postfertilization were exposed to aconitine at doses of 0.5, 1, and 2 μM for 24 h, and SH-SY5Y cells were treated with 50, 100, and 200 μM of aconitine for 24 h. Results demonstrated that aconitine treatment induced deformities and enhanced the swimming behavior of zebrafish larvaes. Aconitine exposure suppressed cell proliferation and increased the number of reactive oxygen species and apoptosis in zebrafish larvaes and SH-SY5Y cells. Aconitine altered the levels of dopamine and its metabolites by regulating the expression of genes and proteins related to dopamine synthesis, storage, degradation, and reuptake in vivo and in vitro. Moreover, aconitine activated the AC/cAMP/PKA pathway by activating the dopamine D1 receptor (D1R) and inhibiting the dopamine D2 receptor (D2R) to disturb intracellular calcium homeostasis, eventually leading to the damage of nerve cells. Furthermore, the D1R antagonist SCH23390 and D2R agonist sumanirole pretreatment effectively attenuated the excitatory state of larvaes. Sumanirole and PKA antagonist H-89 pretreatment effectively decreased intracellular Ca2+ accumulation induced by aconitine in vivo. SCH23390 and sumanirole also reduced aconitine-induced cytotoxicity by inhibiting the AC/cAMP/PKA pathway in vitro. These results suggested that dopamine homeostasis imbalance and dopamine receptors (DRs)-mediated AC/cAMP/PKA pathway activation might be vital mechanisms underlying aconitine-induced neurological injury. [ABSTRACT FROM AUTHOR]

Breast cancer has an extremely high incidence in women, and its morbidity and mortality rank first among female tumors. With the increasing development of molecular biology and genomics, molecular targeted therapy has become one of the most active areas in breast cancer treatment research and has also achieved remarkable achievements. However, molecular targeted therapy is mainly aimed at HER2-positive breast cancer and has not yet achieved satisfactory curative effect on HER2-negative breast cancer. This article describes the potential targets that may be used for breast cancer treatment from the aspects of PI3K/AKT signaling pathway, DDR, angiogenesis, the cell cycle, breast cancer stem cells, etc. , and explores possible inhibitors for the treatment of HER2-negative breast cancer, such as PI3K inhibitors, AKT inhibitors and m-TOR inhibitors that inhibit the PI3K/AKT signaling pathway, small molecule tyrosine kinase inhibitors that restrain angiogenesis, CDK inhibitors, aurora kinase inhibitors and HDAC inhibitors that block cell cycle, as well as the drugs targeting breast cancer stem cells which have been a hit, aiming to provide a new idea and strategy for the treatment of HER2-negative breast cancer. [ABSTRACT FROM AUTHOR]

Leaf senescence is an important process of growth and development in plant, and it is a programmed decline controlled by a series of genes. In this study, the biochemical properties and transcriptome at five maturity stages (M1∼M5) of tobacco leaves were analyzed to reveal the dynamic changes in leaf senescence of tobacco. A total of 722, 1,534, 3,723, and 6,933 genes were differentially expressed (DEG) between M1 and M2, M1 and M3, M1 and M4, and M1 and M5, respectively. Significant changes of nitrogen, sugars, and the DEGs related to metabolite accumulation were identified, suggesting the importance of energy metabolism during leaf senescence. Gene Ontology (GO) analysis found that DEGs were enriched in biosynthetic, metabolic, photosynthesis, and redox processes, and especially, the nitrogen metabolic pathways were closely related to the whole leaf senescence process (M1∼M5). All the DEGs were grouped into 12 expression profiles according to their distinct expression patterns based on Short Time-series Expression Miner (STEM) software analysis. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis found that these DEGs were enriched in pathways of carbon metabolism, starch and sucrose metabolism, nitrogen metabolism, and photosynthesis among these expression profiles. A total of 30 core genes were examined by Weight Gene Co-expression Network Analysis (WGCNA), and they appeared to play a crucial role in the regulatory of tobacco senescence. Our results provided valuable information for further functional investigation of leaf senescence in plants. [ABSTRACT FROM AUTHOR]

The Golden2-like (GLK) transcription factors play important roles in regulating chloroplast growth, development, and senescence in plants. In this study, a total of 89 NtGLK genes (NtGLK1–NtGLK89) were identified in the tobacco genome and were classified into 10 subfamilies with variable numbers of exons and similar structural organizations based on the gene structure and protein motif analyses. Twelve segmental duplication pairs of NtGLK genes were identified in the genome. These NtGLK genes contain two conserved helix regions related to the HLH structure, and the sequences of the first helix region are less conserved than that of the second helix motif. Cis -regulatory elements of the NtGLK promoters were widely involved in light responsiveness, hormone treatment, and physiological stress. Moreover, a total of 206 GLK genes from tomato, tobacco, maize, rice, and Arabidopsis were retrieved and clustered into eight subgroups. Our gene expression analysis indicated that NtGLK genes showed differential expression patterns in tobacco leaves at five senescence stages. The expression levels of six NtGLK genes in group C were reduced, coinciding precisely with the increment of the degree of senescence, which might be associated with the function of leaf senescence of tobacco. Our results have revealed valuable information for further functional characterization of the GLK gene family in tobacco. [ABSTRACT FROM AUTHOR]

Class III peroxidases (PRXs) are plant-specific enzymes and play important roles in plant growth, development and stress response. In this study, a total of 102 non-redundant PRX gene members (StPRXs) were identified in potato (Solanum tuberosum L.). They were divided into 9 subfamilies based on phylogenetic analysis. The members of each subfamily were found to contain similar organizations of the exon/intron structures and protein motifs. The StPRX genes were not equally distributed among chromosomes. There were 57 gene pairs of segmental duplication and 26 gene pairs of tandem duplication. Expression pattern analysis based on the RNA-seq data of potato from public databases indicated that StPRX genes were expressed differently in various tissues and responded specifically to heat, salt and drought stresses. Most of the StPRX genes were expressed at significantly higher levels in root than in other tissues. In addition, real-time quantitative PCR (qRT-PCR) analysis for 7 selected StPRX genes indicated that these genes displayed various expression levels under abiotic stresses. Our results provide valuable information for better understanding the evolution of StPRX gene family in potato and lay the vital foundation for further exploration of PRX gene function in plants. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that accounts for the largest proportion of breast cancer-related deaths. Thus, it is imperative to search for novel drug candidates with potent anti-TNBC effects. Recent studies suggest that isoliquiritigenin (ISL) can significantly suppress the growth, migration, and invasion of breast cancer cells. We previously synthesized ISL derivatives and found that 3′,4′,5′,4″-tetramethoxychalcone (TMC) inhibits TNBC cell proliferation to a greater degree than ISL. The present study aimed to investigate the mechanisms underlying the anti-TNBC effects of TMC in vitro and in vivo. We show that TMC significantly inhibits the proliferative, migratory, and invasive abilities of MDA-MB-231 and BT549 cells. TMC induces apoptosis through the upregulation of Bax and downregulation of Bcl-2. PCR arrays demonstrate a significant decrease in miR-374a expression in TNBC cells after 24-h TMC treatment. MiR-374a is overexpressed in TNBC cells and has oncogenic properties. Real-time PCR analysis confirmed that TMC inhibits miR-374a in a dose-dependent manner, and luciferase assays confirmed that BAX is targeted by miR-374a. Further, we show that TMC increases Bax protein and mRNA levels by inhibiting miR-374a. TMC also attenuates TNBC tumor volumes and weights in vivo. These results demonstrate that TMC inhibits TNBC cell proliferation, foci formation, migration, invasion, and tumorigenesis, suggesting its potential to serve as a novel drug for treating TNBC through miR-374a repression. [ABSTRACT FROM AUTHOR]

The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is increasing globally, with different molecular mechanisms described. Here we studied the molecular mechanisms of carbapenem resistance, including clonal and plasmid dissemination, of 67 CRE isolates collected between 2012 and 2016 from a tertiary hospital in Eastern China, an CRE endemic region. Species identification and susceptibility testing were performed using the BD Phoenix Automated Microbiology System. Isolates were characterized by PCR (for carbapenemases, ESBLs, AmpC and porin genes), multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and conjugation transfer experiments. Selected bla KPC-2 -harboring plasmids were subjected to next-generation sequencing using the Illumina Miseq platform. Among the 67 CRE isolates, 42 Klebsiella pneumoniae , 10 Serratia marcescens , 6 Enterobacter cloacae , 2 Raoultella ornithinolytica , 2 K. oxytoca , 1 K. aerogenes , and 4 Escherichia coli isolates were identified. Six different carbapenemases were detected, including bla KPC-2 (n = 45), bla KPC-3 (n = 1), bla NDM-1 (n = 6), bla NDM-5 (n = 1), bla IMP-4 (n = 2), and bla VIM-1 (n = 2); bla OXA-48-like genes were not detected. One E. cloacae strain possessed both bla NDM-1 and bla KPC-3, while two E. cloacae isolates harbored bla NDM-1 and bla VIM-1. ESBLs (CTX-M, SHV, and TEM) and/or AmpC (CMY, DHA, and ACT/MIR) genes were also identified in 59 isolates, including 13 strains that lacked carbapenemases. Several insertions or stop codon mutations were found within porin genes of K. pneumoniae, E. coli and S. marcescens isolates, both with and without carbapenemases. The 42 K. pneumoniae isolates belonged to 12 different sequence types (ST), with ST11 being the most common, while the 6 E. cloacae isolates comprised 4 different STs. The 10 S. marcescens all shared the same PFGE pulsotype, suggestive of clonal spread. Complete plasmid sequencing and PCR screening revealed both intra-strain and inter-species spread of a common bla KPC-2-harboring plasmid in our hospital. Taken together, our study revealed extensive genetic diversity among CRE isolates form a single Chinese hospital. CRE isolates circulating in the hospital differ significantly in their species, STs, porin genes, carbapenemase genes, and their plasmid content, highlighting the complex dissemination of CRE in this endemic region. [ABSTRACT FROM AUTHOR]

Chinese materia medica (CMM) has been applied for the prevention and treatment of diseases for thousands of years. However, arrhythmia, myocardial ischemia, heart failure, and other cardiac adverse reactions during CMM application were gradually reported. CMM-induced cardiotoxicity has aroused widespread attention. Our review aimed to summarize the risk compounds, preclinical toxicity evaluation, and potential mechanisms of CMM-induced cardiotoxicity. All relevant articles published on the PubMed, Embase, and China National Knowledge Infrastructure (CNKI) databases for the latest twenty years were searched and manually extracted. The risk substances of CMM-induced cardiotoxicity are relatively complex. A single CMM usually contains various risk compounds, and the same risk substance may exist in various CMM. The active and risk substances in CMM may be transformed into each other under different conditions, such as drug dosage, medication methods, and body status. Generally, the risk compounds of CMM-induced cardiotoxicity can be classified into alkaloids, terpenoids, steroids, heavy metals, organic acids, toxic proteins, and peptides. Traditional evaluation methods of chemical drug-induced cardiotoxicity primarily include cardiac function monitoring, endomyocardial biopsy, myocardial zymogram, and biomarker determination. In the preclinical stage, CMM-induced cardiotoxicity should be systematically evaluated at the overall, tissue, cellular, and molecular levels, including cardiac function, histopathology, cytology, myocardial zymogram, and biomarkers. Thanks to the development of systematic biology, the higher specificity and sensitivity of biomarkers, such as genes, proteins, and metabolic small molecules, are gradually applied for evaluating CMM-induced cardiotoxicity. Previous studies on the mechanisms of CMM-induced cardiotoxicity focused on a single drug, monomer or components of CMM. The interaction among ion homeostasis (sodium, potassium, and calcium ions), oxidative damage, mitochondrial injury, apoptosis and autophagy, and metabolic disturbance is involved in CMM-induced cardiotoxicity. Clarification on the risk compounds, preclinical toxicity evaluation, and potential mechanisms of CMM-induced cardiotoxicity must be beneficial to guide new CMM development and post-marketed CMM reevaluation. [ABSTRACT FROM AUTHOR]