A novel GSK3ß inhibitor 5n attenuates acute kidney injury.

Acute kidney injury (AKI) is a clinical syndrome with high morbidity and mortality caused by various factor. The specific strategies for AKI are still lacking. GSK3ß is widely expressed in the kidneys. In acute models of injury, GSK3ß promotes the systemic inflammatory response, increases the proinflammatory release of cytokines, induces apoptosis, and alters cell proliferation. We screened a series of 3-(4-pyridyl)-5-(4-sulfamido-phenyl)-1,2,4-oxadiazole derivatives which are recognized as new GSK3ß inhibitors, and found that 5n had the least toxicity and the best cell protection. We then tested the anti-inflammatory and reno-protective effect of 5n in cisplatin-treated tubular epithelial cells. 5n had anti-inflammation effect indicated by phosphor-NF-κB detection. Finally, we found that 5n ameliorated renal injury and inflammation in cisplatin-induced AKI mouse model. Silencing GSK3ß inhibited cell injury and inflammation induced by cisplatin. We found that GSK3ß interacted with PP2Ac to modulate the activity of NF-κB. In conclusion, 5n, the novel GSK3ß inhibitor, protects against AKI via PP2Ac-dependent mechanisms which may provide a potential strategy for the treatment of AKI in clinic.

Mild hypothermia reduces lipopolysaccharide-induced microglial activation via down-regulation of Tent5c.

Microglial activation is a critical factor in the pathogenesis and progression of neuroinflammatory diseases. Mild hypothermia, known for its neuroprotective properties, has been shown to alleviate microglial activation. In this study, we explore the differentially expressed (DE) mRNAs and long non-coding RNAs (lncRNAs) in BV-2 microglial cells under different conditions: normal temperature (CN), mild hypothermia (YT), normal temperature with lipopolysaccharide (LPS), and mild hypothermia with LPS (LPS + YT). Venn analysis revealed 119 DE mRNAs that were down-regulated in the LPS + YT vs LPS comparison but up-regulated in the CN vs LPS comparison, primarily enriched in Gene Ontology terms related to immune and inflammatory responses. Furthermore, through Venn analysis of YT vs CN and LPS + YT vs LPS comparisons, we identified 178 DE mRNAs and 432 DE lncRNAs. Among these transcripts, we validated the expression of Tent5c at the protein and mRNA levels. Additionally, siRNA-knockdown of Tent5c attenuated the expression of pro-inflammatory genes (TNF-α, IL-1ß, Agrn, and Fpr2), cellular morphological changes, NLRP3 and p-P65 protein levels, immunofluorescence staining of p-P65 and number of cells with ASC-speck induced by LPS. Furthermore, Tent5c overexpression further potentiated the aforementioned indicators in the context of mild hypothermia with LPS treatment. Collectively, our findings highlight the significant role of Tent5c down-regulation in mediating the anti-inflammatory effects of mild hypothermia.

Phosphoglycerate-kinase-1 Is a Potential Prognostic Biomarker in HNSCC and Correlates With Immune Cell Infiltration.

BACKGROUND/AIM: Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cancer worldwide, with a high recurrence rate and a low cure rate. Phosphoglycerate kinase 1 (PGK1), an essential enzyme in the aerobic glycolysis pathway, is a prognostic marker for a variety of cancers. However, it remains unclear whether a PGK1-based immune signature can be used as a prognostic biomarker in HNSCC patients. MATERIALS AND METHODS: We explored the potential oncogenic mechanisms of PGK1 by multiple bioinformatics analyses combined with multiple databases, including the correlation between PGK1 and prognosis, and the infiltration of immune cells in HNSCC. Functional enrichment analyses were further performed to investigate the potential role of PGK1 in HNSCC. RESULTS: The expression of PGK1 was significantly higher in HNSCC tissues compared to normal tissues. High expression of PGK1 was associated with poor prognosis in HNSCC, and multivariate cox regression analysis showed that PGK1 could be an independent prognostic factor in HNSCC. Pathway analysis revealed that PGK1 may regulate the pathogenesis of HNSCC through the immune signaling pathway. Moreover, PGK1 expression significantly correlated with the infiltration level of 16 types of immune cells. CONCLUSION: The current study reports that PGK1 expression was increased in HNSCC and that high PGK1 expression was closely associated with poor prognosis and immune cell infiltration, which could serve as a promising independent prognostic biomarker and potential immunotherapeutic target for HNSCC.

[Association of Serine/Threonine Phosphoprotein Phosphatase 4C Expression With Prognosis of Gastric Cancer].

Objective To investigate the expression level of serine/threonine phosphoprotein phosphatase 4C(PPP4C)in gastric cancer,and analyze its relationship with prognosis and the underlying regulatory mechanism.Methods The clinical data of 104 gastric cancer patients admitted to the First Affiliated Hospital of Bengbu Medical College between January 2012 and August 2016 were collected.Immunohistochemical staining was employed to determine the expression levels of PPP4C and Ki-67 in the gastric cancer tissue.The gastric cancer cell lines BGC823 and HGC27 were cultured and transfected with the vector for PPP4C knockdown,the vector for PPP4C overexpression,and the lentiviral vector(control),respectively.The effects of PPP4C on the cell cycle and proliferation were analyzed and the possible regulatory mechanisms were explored.Results PPP4C was highly expressed in gastric cancer(P<0.001),and its expression promoted malignant progression of the tumor(all P<0.01).Univariate and Cox multivariate analysis clarified that high expression of PPP4C was an independent risk factor affecting the 5-year survival rate of gastric cancer patients(P=0.003).Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis suggested that PPP4C may be involved in the cell cycle.The correlation analysis showed that the expression of PPP4C was positively correlated with that of Ki-67 in gastric cancer(P<0.001).The up-regulation of PPP4C expression increased the proportion of tumor cells in the S phase,alleviated the G2/M phase arrest,and promoted the proliferation of gastric cancer cells and the expression of cyclin D1 and cyclin-dependent kinase 6(CDK6)(all P<0.05).The down-regulation of PPP4C decreased the proportion of gastric cancer cells in the S phase,promoted G2/M phase arrest,and inhibited cell proliferation and the expression of cyclin D1,CDK6,and p53(all P<0.05).p53 inhibitors promoted the proliferation of BGC823 and HGC27 cells in the PPP4C knockdown group(P<0.001,P<0.001),while p53 activators inhibited the proliferation of BGC823 and HGC27 cells in the PPP4C overexpression group(P<0.001,P=0.002).Conclusions PPP4C is highly expressed in gastric cancer and affects the prognosis of the patients.It may increase the proportion of gastric cancer cells in the S phase and alleviate the G2/M phase arrest by inhibiting p53 signaling,thereby promoting cell proliferation.

PT-symmetric solitons and parameter discovery in self-defocusing saturable nonlinear Schrödinger equation via LrD-PINN.

We propose a physical information neural network with learning rate decay strategy (LrD-PINN) to predict the dynamics of symmetric, asymmetric, and antisymmetric solitons of the self-defocusing saturable nonlinear Schrödinger equation with the PT-symmetric potential and boost the predicted evolutionary distance by an order of magnitude. Taking symmetric solitons as an example, we explore the advantages of the learning rate decay strategy, analyze the anti-interference performance of the model, and optimize the network structure. In addition, the coefficients of the saturable nonlinearity strength and the modulation strength in the PT-symmetric potential are reconstructed from the dataset of symmetric soliton solutions. The application of more advanced machine learning techniques in the field of nonlinear optics can provide more powerful tools and richer ideas for the study of optical soliton dynamics.

Phytochemistry and biological activities of corynanthe alkaloids.

Medicinal plants constitute a source for designing clinically useful drugs targeting diseases through various mechanisms. Plant secondary metabolites can be used as lead compounds of drugs. Corynanthe alkaloids are highly abundant natural bioactive substances of various core structures possessing important properties such as nerve excitation and antimalarial and analgesic effects. In this review, we summarize and review the state-of-the-art corynanthe-type alkaloid research focusing on phytochemistry, pharmacology, and structural chemistry. Approximately 120 articles reporting 231 alkaloids classified into simple corynanthe, yohimbine, oxindole corynanthe, mavacurane, sarpagine, akuammiline, strychnos, and ajmaline-type groups were compiled. Relevant biological properties discussed include antiviral, antibacterial, anti-inflammatory, antimalarial, muscle-relaxant, vasorelaxant, and analgesic activities and activities affecting the main nervous and cardiac systems, as well as NF-κB inhibitory and Na+-glucose cotransporter inhibitory properties. This review provides insights and a reference for future studies, thus paving the way for the discovery of drugs based on corynanthe alkaloids.

New Type of Tannins Identified from the Seeds of Cornus officinalis Sieb. et Zucc. by HPLC-ESI-MS/MS.

There is a lack of information on the compound profile of Cornus officinalis Sieb. et Zucc. seeds. This greatly affects their optimal utilization. In our preliminary study, we found that the extract of the seeds displayed a strong positive reaction to the FeCl3 solution, indicating the presence of polyphenols. However, to date, only nine polyphenols have been isolated. In this study, HPLC-ESI-MS/MS was employed to fully reveal the polyphenol profile of the seed extracts. A total of 90 polyphenols were identified. They were classified into nine brevifolincarboxyl tannins and their derivatives, 34 ellagitannins, 21 gallotannins, and 26 phenolic acids and their derivatives. Most of these were first identified from the seeds of C. officinalis. More importantly, five new types of tannins were reported for the first time: brevifolincarboxyl-trigalloyl-hexoside, digalloyl-dehydrohexahydroxydiphenoyl (DHHDP)-hexdside, galloyl-DHHDP-hexoside, DHHDP-hexahydroxydiphenoyl(HHDP)-galloyl-gluconic acid, and peroxide product of DHHDP-trigalloylhexoside. Moreover, the total phenolic content was as high as 79,157 ± 563 mg gallic acid equivalent per 100 g in the seeds extract. The results of this study not only enrich the structure database of tannins, but also provide invaluable aid to its further utilization in industries.

Deep neural network for modeling soliton dynamics in the mode-locked laser.

Integrating the information of the first cycle of an optical pulse in a cavity into the input of a neural network, a bidirectional long short-term memory (Bi_LSTM) recurrent neural network (RNN) with an attention mechanism is proposed to predict the dynamics of a soliton from the detuning steady state to the stable mode-locked state. The training and testing are based on two typical nonlinear dynamics: the conventional soliton evolution from various saturation energies and soliton molecule evolution under different group velocity dispersion coefficients of optical fibers. In both cases, the root mean square error (RMSE) for 80% of the test samples is below 15%. In addition, the width of the conventional soliton pulse and the pulse interval of the soliton molecule predicted by the neural network are consistent with the experimental results. These results provide a new insight into the nonlinear dynamics modeling of the ultrafast fiber laser.

[Prognostic Value of the Expression of Myeloid Leukemia Factor 1-Interacting Protein in Gastric Cancer and Its Regulatory Role in Tumor Progression].

Objective: To investigate the prognostic value of the expression of myeloid leukemia factor 1-interacting protein (MLF1IP) in gastric cancer tissue and its regulatory role in tumor progression. Methods: Gene Expression Omnibus (GEO) database was used to analyze the expression level of MLF1IP in tumor tissues of gastric cancer patients. Kaplan-Meier Plotter database was used to analyze the relationship between MLF1IP expression level and patient prognosis. We conducted a retrospective analysis of 108 gastric cancer patients who had undergone radical surgery at our hospital between January 2015 and December 2015. The expression of MLF1IP in gastric cancer tissue and adjacent tissues was examined. We analyzed the relationship between MLF1IP and the clinicopathological parameters of gastric cancer patients and its impact on the long-term prognosis of gastric cancer patients. Univariate and multivariate regression analyses were done to identify the risk factors affecting the long-term prognosis of gastric cancer patients. The assessment value of MLF1IP for long-term prognosis of gastric cancer was analyzed with ROC curve. The effects of MLF1IP on the proliferation, migration, and invasion of gastric cancer cells were analyzed in vitro with gastric cancer cell line (MGC803). A xenograft tumor model was established with nude mice to analyze in vivo the effect of MLF1IP on tumor growth. Results: The results of the gastric cancer cohort GSE29272 of GEO database showed that the expression level of MLF1IP in gastric cancer tissues was significantly higher than that in normal tissues ( P<0.05). Analysis with Kaplan-Meier Plotter database indicated that high MLF1IP expression was correlated with poor prognosis in gastric cancer patients. Immunohistochemical analysis showed that the expression level of MLF1IP in gastric cancer tissues was higher than that in adjacent tissues ( P<0.05). Correlation analysis showed that the MLF1IP level in gastric cancer tissue was positively correlated with Ki67 ( r=0.609, P<0.01), peripheral blood carcinoembryonic antigen (CEA) ( r=0.572, P<0.01) and carbohydrate antigen 19-9 (CA19-9) ( r=0.623, P<0.01). Kaplan-Meier (K-M) survival analysis showed that the 5-year survival rate of patients in the MLF1IP high expression group was significantly lower than that in the MLF1IP low expression group ( P<0.01). Cox regression analysis showed that independent risk factors for 5-year survival after radical gastrectomy for gastric cancer included the expression of MLF1IP ( HR=2.508, 95% CI: 1.259-4.999), CEA≥5 µg/L ( HR=2.171, 95% CI: 1.152-4.092), CA19-9≥37 kU/L ( HR=2.401, 95% CI: 1.094-5.269), and T3-T4 stages ( HR=2.779, 95% CI: 1.049-7.358) and N2-N3 stages ( HR=2.072, 95% CI: 1.100-3.904). ROC analysis showed that the sensitivity, specificity, and accuracy of MLF1IP (the cut-off value was 3.00 relative protein expression level) in assessing the 5-year survival rate after radical gastrectomy for gastric cancer was 75.00%, 76.92%, and 76.2%, respectively ( P<0.05). CCK-8, Transwell assay, and scratch assays showed that in vitro knocking down of MLF1 IP gene expression significantly inhibited the proliferation, migration and invasion of gastric cancer cells. Subcutaneous tumor xenograft experiment in nude mice showed that knocking down MLF1 IP gene significantly inhibited tumor growth. Conclusion: Increased expression of MLF1IP in gastric cancer tissue, which may be involved in the malignant activities of proliferation, migration, and invasion of gastric cancer cells, has a certain predictive value for poor prognosis.

Epigallocatechin Gallate Attenuates Gentamicin-Induced Nephrotoxicity by Suppressing Apoptosis and Ferroptosis.

Gentamicin (GEN) is a kind of aminoglycoside antibiotic with the adverse effect of nephrotoxicity. Currently, no effective measures against the nephrotoxicity have been approved. In the present study, epigallocatechin gallate (EG), a useful ingredient in green tea, was used to attenuate its nephrotoxicity. EG was shown to largely attenuate the renal damage and the increase of malondialdehyde (MDA) and the decrease of glutathione (GSH) in GEN-injected rats. In NRK-52E cells, GEN increased the cellular ROS in the early treatment phase and ROS remained continuously high from 1.5 H to 24 H. Moreover, EG alleviated the increase of ROS and MDA and the decrease of GSH caused by GEN. Furthermore, EG activated the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). After the treatment of GEN, the protein level of cleaved-caspase-3, the flow cytometry analysis and the JC-1 staining, the protein levels of glutathione peroxidase 4 (GPX4) and SLC7A11, were greatly changed, indicating the occurrence of both apoptosis and ferroptosis, whereas EG can reduce these changes. However, when Nrf2 was knocked down by siRNA, the above protective effects of EG were weakened. In summary, EG attenuated GEN-induced nephrotoxicity by suppressing apoptosis and ferroptosis.

Symmetry breaking of solitons in the PT-symmetric nonlinear Schrödinger equation with the cubic-quintic competing saturable nonlinearity.

The symmetry breaking of solitons in the nonlinear Schrödinger equation with cubic-quintic competing nonlinearity and parity-time symmetric potential is studied. At first, a new asymmetric branch separates from the fundamental symmetric soliton at the first power critical point, and then, the asymmetric branch passes through the branch of the fundamental symmetric soliton and finally merges into the branch of the fundamental symmetric soliton at the second power critical point, while the power of the soliton increases. This leads to the symmetry breaking and double-loop bifurcation of fundamental symmetric solitons. From the power-propagation constant curves of solitons, symmetric fundamental and tripole solitons, asymmetric solitons can also exist. The stability of symmetric fundamental solitons, asymmetric solitons, and symmetric tripole solitons is discussed by the linear stability analysis and direct simulation. Results indicate that symmetric fundamental solitons and symmetric tripole solitons tend to be stable with the increase in the soliton power. Asymmetric solitons are unstable in both high and low power regions. Moreover, with the increase in saturable nonlinearity, the stability region of fundamental symmetric solitons and symmetric tripole solitons becomes wider.

[Comparison of three root canal disinfection methods for removal of Enterococcus faecalis under minimally invasive root canal treatment].

PURPOSE: To obtain an efficient and simple root canal disinfection method based on minimally invasive root canal treatment by comparing different root canal disinfection methods between minimally invasive root canal treatment and conventional root canal treatment. METHODS: Sixty-six extracted maxillary first molars were randomly divided into experimental group (computer-guided precision minimally invasive root canal treatment) and control group (conventional root canal treatment). All teeth were prepared to ProTaper universal F2, and Enterococcus faecalis infection models were established.Each group was randomly divided into three subgroups, sodium hypochlorite+EDTA root canal irrigation, sodium hypochlorite+EDTA+ultrasonic and sodium hypochlorite +EDTA +Er: YAG laser. After root canal disinfection,the samples were collected by paper tip method and cultured, and colony forming units (CFU) values of each sample were calculated. Then dentin debris was prepared and collected with F3 file. After being diluted and cultured, the CFU value was calculated. Statistical analysis was performed by SPSS 26.0 software package. RESULTS: Comparison of the amount of bacterial inner wall of root canal between the experimental group and the control group showed that the germicidal efficacy of group C and group B were significantly better than that of group A (P＜0.05), but there was no significant difference between group B and group C(P＞0.05). In the experimental group, there was significant difference between group B1, C1 and A1 (P＜0.05). The results of group B1 and C1 were lower than that of group A1, but there was no significant difference between group B1 and group C1(P＞0.05). In the control group, there were significant differences between group B2, C2 and A2 (P＜0.05). The results of group B2 and C2 were lower than that of group A2, but there was no significant difference between group B2 and C2(P＞0.05). Comparison of the amount of bacteria in dentin debris between the experimental group and the control group showed that the effect of group C was the best, followed by group B, and group A, and there were significant differences between three groups(P＜0.05). CONCLUSIONS: The disinfection effect of Er:YAG laser or ultrasound assisted computer-guided precision minimally invasive root canal treatment is similar to conventional root canal treatment, and Er:YAG laser is better than ultrasound in removing bacteria from dentinal tubules, which is more suitable for minimally invasive root canal treatment.

Propagation and interaction between special fractional soliton and soliton molecules in the inhomogeneous fiber.

INTRODUCTION: Fractional nonlinear models have been widely used in the research of nonlinear science. A fractional nonlinear Schrödinger equation with distributed coefficients is considered to describe the propagation of pi-second pulses in inhomogeneous fiber systems. However, soliton molecules based on the fractional nonlinear Schrödinger equation are hardly reported although many fractional soliton structures have been studied. OBJECTIVES: This paper discusses the propagation and interaction between special fractional soliton and soliton molecules based on analytical solutions of a fractional nonlinear Schrödinger equation. METHODS: Two analytical methods, including the variable-coefficient fractional mapping method and Hirota method with the modified Riemann-Liouville fractional derivative rule, are used to obtain analytical non-travelling wave solutions and multi-soliton approximate solutions. RESULTS: Analytical non-travelling wave solutions and multi-soliton approximate solutions are derived. The form conditions of soliton molecules are given, and the dynamical characteristics and interactions between special fractional solitons, multi-solitons and soliton molecules are discussed in the periodic inhomogeneous fiber and the exponential dispersion decreasing fiber. CONCLUSION: Analytical chirp-free and chirped non-traveling wave solutions and multi-soliton approximate solutions including soliton molecules are obtained. Based on these solutions, dynamical characteristics and interactions between special fractional solitons, multi-solitons and soliton molecules are discussed. These theoretical studies are of great help to understand the propagation of optical pulses in fibers.

Texture analysis of orbital magnetic resonance imaging for monitoring and predicting treatment response to glucocorticoids in patients with thyroid-associated ophthalmopathy.

PURPOSE: To evaluate the value of MRI-based texture analysis of extraocular muscle (EOM) and orbital fat (OF) in monitoring and predicting the response to glucocorticoid (GC) therapy in patients with thyroid-associated ophthalmopathy (TAO). METHODS: Thirty-seven active and moderate-to-severe TAO patients (responders, n = 23; unresponders, n = 14) were retrospectively enrolled. MRI-based texture parameters (entropy, uniformity, skewness and kurtosis) of EOM and OF were measured before and after GC therapy, and compared between groups. Correlations between the changes of clinical activity score (CAS) and imaging parameters before and after treatment were assessed. Receiver operating characteristic curves were used to evaluate the predictive value of identified variables. RESULTS: Responsive TAOs showed significantly decreased entropy and increased uniformity at EOM and OF after GC therapy (P < 0.01), while unresponders showed no significance. Changes of entropy and uniformity at EOM and OF were significantly correlated with changes of CAS before and after treatment (P < 0.05). Responders showed significantly lower entropy and higher uniformity at EOM than unresponders before treatment (P < 0.01). Entropy and uniformity of EOM and disease duration were identified as independent predictors for responsive TAOs. Combination of all three variables demonstrated optimal efficiency (area under curve, 0.802) and sensitivity (82.6%), and disease duration alone demonstrated optimal specificity (100%) for predicting responsive TAOs. CONCLUSION: MRI-based texture analysis can reflect histopathological heterogeneity of orbital tissues. It could be useful for monitoring and predicting the response to GC in TAO patients.

The study of Raddeanin A cerebrovascular endothelial cell trafficking through P-glycoprotein.

As one of the natural triterpenoids isolated from Anemone Raddeana Regel, Raddeanin A (RA) has been confirmed to possess therapeutic effects against multiple tumorigeneses, especially for the onset of glioblastoma and growth in human brains. However, the mechanism by which this happens remains poorly understood in terms of the vascular endothelium trafficking routine of RA through the brain-blood barrier (BBB). To seek such answers, human brain microenvironment endothelial cells (HBMECs) were used to stimulate the microenvironment in vitro, and to explore the intracellular accumulation of RA. The results of this experiment illustrated that RA has a relative moderate transport affinity for such cells. The kinetic parameter Km was 37.01 ± 2.116 µM and Vmax was 9.412 ± 0.1375 nM/min/mg of protein. Interestingly, protein downregulation of P-glycoprotein (P-gp, ABCB1/MDR1) significantly activated RA transmembrane activity, which proves that P-gp is responsible for RA cellular trafficking. In addition, the selective non-specific inhibitor, LY335979 increased either RA or the classical substrate of P-gp, digoxin, intracellular accumulation by restricting the transporter's function but without jeopardizing cytomembrane proteins. Moreover, a decrease in the expression or activity of P-gp triggered RA drug resistance to HBMECs. In summary, our data showed that both the expression and function of P-gp are all necessary for RA transmembrane trafficking through cerebrovascular endothelial cells. This study provides significant evidence for the presence of a connection between RA transport and P-gp variation during drug BBB penetration. It is also suggesting some vital guidance on the RA pharmacodynamic effect in human brains.

Long noncoding RNA AC073284.4 suppresses epithelial-mesenchymal transition by sponging miR-18b-5p in paclitaxel-resistant breast cancer cells.

Breast cancer (BC) is the most prevalent malignant cancer in the world, is the leading cause of cancer-related death female. Recently, there is accumulating evidence that long noncoding RNAs (lncRNAs) might as an important role in the progression of BC. (epithelial-mesenchymal transition (EMT) is considered to play a vital role in tumor cells migration and invasion. Nevertheless, the entire biological mechanisms and functions of lncRNAs in tumor migration, invasion, and EMT remain uncertain. In the present research, we observed that the expression of lncRNA AC073284.4 was downregulated in BC paclitaxel-resistant (PR) cells (MCF-7/PR) and tissues. Bioinformatics analysis predicted that miR-18b-5p was a direct target of AC073284.4, which has been validated by dual-luciferase reporter gene assay. We further proved that AC073284.4 could directly bind to miR-18b-5p and relieve the suppression for dedicator of cytokinesis protein 4 (DOCK4). Furthermore, the underlying functional experiments demonstrated that AC073284.4 might sponge miR-18b-5p to attenuate the invasion, metastasis, and EMT of BC cell through upregulating DOCK4 expression. In summary, AC073284.4 might serve as a competing endogenous RNA (ceRNA) in BC progression via modulating miR-18b-5p/DOCK4 axis, which weakens EMT and migration of BC. These results suggesting that AC073284.4 might function as a potential novel diagnostic biomarker in the progression of BC.

The N-terminal polypeptide derived from viral macrophage inflammatory protein II reverses breast cancer epithelial-to-mesenchymal transition via a PDGFRα-dependent mechanism.

NT21MP, a 21-residue peptide derived from the viral macrophage inflammatory protein II, competed effectively with the natural ligand of CXC chemokine receptor 4 (CXCR4), stromal cell-derived factor 1-alpha, to induce apoptosis and inhibit growth in breast cancer. Its role in tumor epithelial-to-mesenchymal transition (EMT) regulation remains unknown. In this study, we evaluated the reversal of EMT upon NT21MP treatment and examined its role in the inhibition of EMT in breast cancer. The parental cells of breast cancer (SKBR-3 and MCF-7) and paclitaxel-resistant (SKBR-3 PR and MCF-7 PR) cells were studied in vitro and in combined immunodeficient mice. The mice injected with SKBR-3 PR cells were treated with NT21MP through the tail vein or intraperitoneally with paclitaxel or saline. Sections from tumors were evaluated for tumor weight and EMT markers based on Western blot. In vitro, the effects of NT21MP, CXCR4 and PDGFRα on tumor EMT were assessed by relative quantitative real-time reverse transcription-polymerase chain reaction, western blot and biological activity in breast cancer cell lines expressing high or low levels of CXCR4. Our results illustrated that NT21MP could reverse the phenotype of EMT in paclitaxel-resistant cells. Furthermore, we found that NT21MP governed PR-mediated EMT partly due to controlling platelet-derived growth factors A and B (PDGFA and PDGFB) and their receptor (PDGFRα). More importantly, NT21MP down-regulated AKT and ERK1/2 activity, which were activated by PDGFRα, and eventually reversed the EMT. Together, these results indicated that CXCR4 overexpression drives acquired paclitaxel resistance, partly by activating the PDGFA and PDGFB/PDGFRα autocrine signaling loops that activate AKT and ERK1/2. Inhibition of the oncogenic EMT process by targeting CXCR4/PDGFRα-mediated pathways using NT21MP may provide a novel therapeutic approach towards breast cancer.

FkbN and Tcs7 are pathway-specific regulators of the FK506 biosynthetic gene cluster in Streptomyces tsukubaensis L19.

FK506 (tacrolimus), which is produced by many Streptomyces strains, is clinically used as an immunosuppressive agent and for treatment of inflammatory skin diseases. Here, we identified that the FK506 biosynthetic gene cluster in an industrial FK506-producing strain Streptomyces tsukubaensis L19 is organized as eight transcription units. Two pathway-specific regulators, FkbN and Tcs7, involved in FK506 biosynthesis from S. tsukubaensis L19 were characterized in vivo and in vitro. FkbN activates the transcription of six transcription units in FK506 biosynthetic gene cluster, and Tcs7 activates the transcription of fkbN. In addition, the DNA-binding specificity of FkbN was determined. Finally, a high FK506-producing strain was constructed by overexpression of both fkbN and tcs7 in S. tsukubaensis L19, which improved FK506 production by 89 % compared to the parental strain.

Characterization of Discrete Phosphopantetheinyl Transferases in Streptomyces tsukubaensis L19 Unveils a Complicate Phosphopantetheinylation Network.

Phosphopantetheinyl transferases (PPTases) play essential roles in both primary metabolisms and secondary metabolisms via post-translational modification of acyl carrier proteins (ACPs) and peptidyl carrier proteins (PCPs). In this study, an industrial FK506 producing strain Streptomyces tsukubaensis L19, together with Streptomyces avermitilis, was identified to contain the highest number (five) of discrete PPTases known among any species thus far examined. Characterization of the five PPTases in S. tsukubaensis L19 unveiled that stw ACP, an ACP in a type II PKS, was phosphopantetheinylated by three PPTases FKPPT1, FKPPT3, and FKACPS; sts FAS ACP, the ACP in fatty acid synthase (FAS), was phosphopantetheinylated by three PPTases FKPPT2, FKPPT3, and FKACPS; TcsA-ACP, an ACP involved in FK506 biosynthesis, was phosphopantetheinylated by two PPTases FKPPT3 and FKACPS; FkbP-PCP, an PCP involved in FK506 biosynthesis, was phosphopantetheinylated by all of these five PPTases FKPPT1-4 and FKACPS. Our results here indicate that the functions of these PPTases complement each other for ACPs/PCPs substrates, suggesting a complicate phosphopantetheinylation network in S. tsukubaensis L19. Engineering of these PPTases in S. tsukubaensis L19 resulted in a mutant strain that can improve FK506 production.

The substrate promiscuity of a phosphopantetheinyl transferase SchPPT for coenzyme A derivatives and acyl carrier proteins.

Phosphopantetheinyl transferases (PPTases) catalyze the posttranslational modification of acyl carrier proteins (ACPs) in fatty acid synthases (FASs), ACPs in polyketide synthases, and peptidyl carrier proteins (PCPs) in nonribosomal peptide synthetases (NRPSs) in all organisms. Some bacterial PPTases have broad substrate specificities for ACPs/PCPs and/or coenzyme A (CoA)/CoA analogs, facilitating their application in metabolite production in hosts and/or labeling of ACPs/PCPs, respectively. Here, a group II PPTase SchPPT from Streptomyces chattanoogensis L10 was characterized to accept a heterologous ACP and acetyl-CoA. Thus, SchPPT is a promiscuous PPTase and may be used on polyketide production in heterologous bacterial host and labeling of ACPs.