Development of a native-locus dual reporter system for the efficient screening of the hyper-production of natural products in Streptomyces.

Streptomyces is renowned for its abundant production of bioactive secondary metabolites, but most of these natural products are produced in low yields. Traditional rational network refactoring is highly dependent on the comprehensive understanding of regulatory mechanisms and multiple manipulations of genome editing. Though random mutagenesis is fairly straightforward, it lacks a general and effective strategy for high throughput screening of the desired strains. Here in an antibiotic daptomycin producer S. roseosporus, we developed a dual-reporter system at the native locus of the daptomycin gene cluster. After elimination of three enzymes that potentially produce pigments by genome editing, a gene idgS encoding the indigoidine synthetase and a kanamycin resistant gene neo were integrated before and after the non-ribosomal peptidyl synthetase genes for daptomycin biosynthesis, respectively. After condition optimization of UV-induced mutagenesis, strains with hyper-resistance to kanamycin along with over-production of indigoidine were efficiently obtained after one round of mutagenesis and target screening based on the dual selection of the reporter system. Four mutant strains showed increased production of daptomycin from 1.4 to 6.4 folds, and significantly improved expression of the gene cluster. Our native-locus dual reporter system is efficient for targeting screening after random mutagenesis and would be widely applicable for the effective engineering of Streptomyces species and hyper-production of these invaluable natural products for pharmaceutical development.

The efficacy and safety of intravenous tranexamic acid in hip fracture surgery: A systematic review and meta-analysis.

OBJECTIVE: The present meta-analysis was conducted to compare the efficacy and safety of intravenous application of tranexamic acid (TXA) with placebo in patients with hip fracture undergoing hip surgeries. METHODS: PubMed, EMBASE and Cochrane Library were searched from inception until March 2018. A combined searching strategy of subject words and random words was adopted. Only randomized clinical trials were included. The comparisons regarding transfusion rate, total blood loss, intraoperative blood loss, postoperative blood loss, postoperative haemoglobin and postoperative thromboembolic complications were conducted. The meta-analysis was performed using Review Manager 5.3, and the bias evaluation was based on the Cochrane Handbook 5.1.0. RESULTS: Ten randomized controlled trials published from 2007 to 2018 were included in the meta-analysis. The results showed that there were significant differences in the two groups concerning transfusion rate of allogeneic blood [risk ratio (RR) = 0.66, 95% confidence interval (CI): 0.56 to 0.78, P = 0.003], total blood loss [mean difference (MD) = -273.00, 95% CI: -353.15 to -192.84, P < 0.00001], intraoperative blood loss (MD = -76.63, 95% CI: -139.55 to -13.71, P = 0.02), postoperative blood loss (MD = -125.29, 95% CI: -221.96 to -28.62, P = 0.01) and postoperative haemoglobin (MD = 0.80, 95% CI: 0.38 to 1.22, P = 0.0002). Nonsignificant differences were found in the incidence of thromboembolic events (RR = 1.38, 95% CI: 0.74 to 2.55, P = 0.31). CONCLUSIONS: This meta-analysis of the available evidence implies that the intravenous route of TXA shows an ability to reduce transfusion requirements and total blood loss, not increasing the incidence of thromboembolic events in patients undergoing hip surgeries. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The result of this meta-analysis shows that the utilization of intravenous TXA in patients with hip fracture undergoing hip surgeries possesses great potential in reducing blood loss and allogeneic blood transfusion safely.

Expression and methylation status of LAMA2 are associated with the invasiveness of nonfunctioning PitNET.

The laminin subunit alpha 2 (LAMA2) gene encodes an alpha 2 chain, which constitutes one of the subunits of laminin 2 (merosin) and laminin 4 (s-merosin). In the current study, we investigated the relationship between LAMA2 promoter methylation status and the invasiveness of clinically nonfunctioning pituitary adenomas (PitNETs). Specimens from patients with nonfunctioning PitNET were classified into three groups according to preoperative computed tomography (CT)/magnetic resonance imaging findings: a normal group (n = 6), non-invasive group (n = 11) and invasive group (n = 6). LAMA2 expression was assessed using quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting, and the methylation status of the LAMA2 promoter region was observed using sodium bisulfite sequencing. Furthermore, 5-aza-2-deoxycytidine was used to explore the relationship between decreased LAMA expression and methylation in PitNET cells. According to the RT-qPCR and western blotting results, LAMA2 expression was downregulated in invasive PitNET, while the methylation of the LAMA2 promoter was increased. Methylation of the LAMA2 promoter decreased the expression of LAMA2. Thus, changes in LAMA2 expression due to promoter methylation were inversely correlated with the invasiveness of PitNET and the protein functions as a tumor suppressor. In addition, overexpression and demethylation of LAMA2 suppressed the invasion of PitNET cells, partially by exerting effects on the PTEN-PI3K/AKT signaling pathway and matrix metalloproteinase-9 (MMP-9). Furthermore, a xenograft model was also generated, and LAMA2 overexpression significantly suppressed tumor growth in vivo. Thus, LAMA2 expression and methylation patterns might be used as biomarkers to predict the prognosis of patients with PitNET.

Bazedoxifene protects cerebral autoregulation after traumatic brain injury and attenuates impairments in blood-brain barrier damage: involvement of anti-inflammatory pathways by blocking MAPK signaling.

OBJECTIVE: Traumatic brain injury (TBI) is a significant cause of death and long-term deficits in motor and cognitive functions for which there are currently no effective chemotherapeutic drugs. Bazedoxifene (BZA) is a third-generation selective estrogen receptor modulator (SERM) and has been investigated as a treatment for postmenopausal osteoporosis. It is generally safe and well tolerated, with favorable endometrial and breast safety profiles. Recent findings have shown that SERMs may have therapeutic benefits; however, the role of BZA in the treatment of TBI and its molecular and cellular mechanisms remain poorly understood. The aim of the present study was to examine the neuroprotective effects of BZA on early TBI in rats and to explore the underlying mechanisms of these effects. MATERIALS AND METHODS: TBI was induced using a modified weight-drop method. Neurological deficits were evaluated according to the neurological severity score (NSS). Morris water maze and open-field behavioral tests were used to test cognitive functions. Brain edema was measured by brain water content, and impairments in the blood-brain barrier (BBB) were evaluated by expression analysis of tight junction-associated proteins, such as occludin and zonula occludens-1 (ZO-1). Neuronal injury was assessed by hematoxylin and eosin (H&E) staining. LC-MS/MS analysis was performed to determine the ability of BZA to cross the BBB. RESULTS: Our results indicated that BZA attenuated the impaired cognitive functions and the increased BBB permeability of rats subjected to TBI through activation of inflammatory cascades. In vivo experiments further revealed that BZA provided this neuroprotection by suppressing TBI-induced activation of the MAPK/NF-κB signaling pathway. Thus, mechanically, the anti-inflammatory effects of BZA in TBI may be partially mediated by blocking the MAPK signaling pathway. CONCLUSIONS: These findings suggest that BZA might attenuate neurological deficits and BBB damage to protect against TBI by blocking the MAPK/NF-κB signaling pathway.

The sodium pump α1 subunit regulates bufalin sensitivity of human glioblastoma cells through the p53 signaling pathway.

Bufalin is the primary component of the traditional Chinese medicine "Chan Su," which has been widely used for cancer treatment at oncology clinics in certain countries. Evidence suggests that this compound possesses potent antitumor activities, although the exact molecular mechanism(s) require further elucidation. Therefore, this study aimed to further clarify the in vitro and in vivo antiglioma effects of bufalin and the molecular mechanism underlying the regulation of drug sensitivity. The anticancer effects of bufalin were determined by colony formation assays, apoptosis assays, and cellular redox state tests of glioma cells. Confocal microscopy was performed to determine the expression changes of the DNA damage biomarker γ-H2AX and the nuclear translocation of p53 in glioma cells. Western blotting and RT-PCR were used to detect the protein and gene expression levels, respectively. Here, we report that bufalin induced glioblastoma cell apoptosis and oxidative stress and triggered DNA damage. The critical roles of the sodium pump α1 subunit (ATP1A1) in mediating the XPO1-targeted anticancer effect of bufalin in human glioma were further confirmed. Mechanistic studies confirmed the important roles of Src and p53 signaling in mediating bufalin-induced apoptosis. Importantly, bufalin also inhibited the growth of glioma xenografts. In conclusion, our study indicated that therapies targeting the ATP1A1 and p53 signaling-mediated mitochondrial apoptotic pathways regulated by bufalin might be potential treatments for human glioma, and these findings will provide molecular bases for developing bufalin into a drug candidate for the treatment of malignant glioma.

Update on the effect of exogenous hormone use on glioma risk in women: a meta-analysis of case-control and cohort studies.

Various studies have confirmed the important roles of endogenous hormones in the development of gliomas, while the roles of exogenous hormones remain controversial. Based on case-control studies and cohort studies, a meta-analysis was exerted to explore the effect of two exogenous hormones use (HRT: hormone replacement therapy; OC: oral contraceptives) on glioma risk. 16 eligible studies, including 11 case-control studies and 5 cohort studies, containing 8055027 women, were included in our study. All included studies have reported the relative risks (RRs) or odds ratios (ORs), and 95% confidence intervals (CIs). We use the fixed-effects model to calculate the estimated overall risk. In case-control studies, the risk of glioma was lower in women who had ever been treated with an exogenous hormone than in the control group (HRT: OR 0.91, 95% CI 0.84-0.99; OC: OR 0.99, 95% CI 0.91-1.07). In research of cohort studies, similar results have been obtained (HRT: RR 0.95, 95% CI 0.83-1.08; OC: RR 0.75, 95% CI 0.66-0.84). Our study further confirmed that the use of exogenous hormones has an important impact on the risk of glioma in women. However, more prospective studies are needed to further confirm this conclusion.

Identification and Validation of Gene Expression Patterns in Cystitis Glandularis Patients and Controls.

Our aim was to investigate differences in gene expression in bladder tissues between cystitis glandularis (CG) patients and healthy controls. Subsequent RNA was isolated from urinary bladder samples from CG patients and healthy controls, followed by RNA sequencing analysis. There were 4263 differentially expressed genes in urinary bladder between CG patients and controls, and 8 genes were verified with real-time PCR, Western blot, and enzyme-linked immunosorbent assay (ELISA) analysis. Gene set enrichment analysis (GSEA) revealed that 25 signaling pathways were upregulated in CG patients, and 17 signaling pathways were found upregulated in healthy controls. The mRNA expression levels of the indicated genes, including CCND1, CCNA1, EGFR, AR, CX3CL1, CXCL6, and CXCL1, were significantly increased in urinary bladder from CG and bladder cancer (BC) patients compared with healthy controls, while TP53 was decreased. CX3CL1, CXCL6, and CXCL1 concentrations in peripheral blood from CG and BC patients were significantly increased compared with healthy controls. The protein expression levels of CCND1, EGFR, and AR were significantly increased in urinary bladder from CG and BC patients compared with healthy controls. In conclusion, the gene expression profile of CG patients has established a foundation to study the gene mechanism of CG and BC progression.

Silencing NUDT21 Attenuates the Mesenchymal Identity of Glioblastoma Cells via the NF-κB Pathway.

The proneural (PN) and mesenchymal (MES) subtypes of glioblastoma multiforme (GBM) are robust and generally consistent with classification schemes. GBMs in the MES subclass are predominantly primary tumors that, compared to PN tumors, exhibit a worse prognosis; thus, understanding the mechanism of MES differentiation may be of great benefit for the treatment of GBM. Nuclear factor kappa B (NF-κB) signaling is critically important in GBM, and activation of NF-κB could induce MES transdifferentiation in GBM, which warrants additional research. NUDT21 is a newly discovered tumor-associated gene according to our current research. The exact roles of NUDT21 in cancer incidence have not been elucidated. Here, we report that NUDT21 expression was upregulated in human glioma tissues and that NUDT21 promoted glioma cell proliferation, likely through the NF-κB signaling pathway. Gene set enrichment analysis, western blotting, and quantitative real-time reverse transcription polymerase chain reaction confirmed that NF-κB inhibitor zeta (NFKBIZ) was a downstream target affected by NUDT21 and that the MES identity genes in glioblastoma cells, CHI3L1 and FN1, were also differentially regulated. Our results suggest that NUDT21 is an upstream regulator of the NF-κB pathway and a potential molecular target for the MES subtype of GBM.

A distinguishable photovoltaic performance on dye-sensitized solar cells using ruthenium sensitizers with a pair of isomeric ancillary ligands.

A pair of isomeric ruthenium sensitizers BM1 and BM2, having TIP based ancillary ligands with a 9-phenylcarbazole tail at the α or ß position of the thiophene unit, shows a distinguishable photovoltaic performance on DSCs (PCEs: 7.33% and 5.33% for BM1 and BM2 as compared with 6.07% for the standard N3-dye).

Advantage of the N-alkylation strategy for retaining the molecular planarity for oligothiophene/imidazole/1,10-phenanthroline-based heterocyclic semiconducting and fluorescent compounds.

A family of planar oligothiophene/imidazole/1,10-phenanthroline (OTIP)-based heterocyclic, aromatic, semiconducting, and fluorescent compounds with N-substituted alkyl chains (allyl, n-butyl, n-octyl, n-dodecyl, and n-cetyl) have been designed and synthesized. They all have specific N-coordination sites, various donor-acceptor spacers, good molecular planarity, suitable solubility, and high thermal stability. In comparison with conventional double ß-alkylation of the thiophene ring, our results reveal that the single imidazole N-alkylation strategy for OTIPs has the advantage of maintaining the planarity of the whole molecule, in addition to improving the solubility, which can be clearly verified by the small dihedral angles between adjacent thiophene/imidazole/1,10-phenanthroline (TIP) rings in eight X-ray single-crystal structures. In particular, n-dodecyl- and n-cetyl-substituted OTIPs (7 and 8) with the same molecular length of 2.37 nm (MW =939 and 1052), show good molecular planarity with the aforementioned dihedral angles of 8.9(5) and 10.4(5)°. Furthermore, special attention has been paid to the physicochemical properties of seven symmetrical OTIPs (6-8, 13-15, and 19), including two to six thiophene rings in the middle of their molecular structures. To the best of our knowledge, this is the first synthetic, structural, and spectral investigation into the N-alkylation of OTIP-based compounds.

Dipyrido[3,2-a:2',3'-c]phenazine-based donor-acceptor aromatic heterocyclic compounds with thienyl and triphenylamino chromophores at the 2,7- and/or 10,13-positions.

A series of T- and H-shaped donor-acceptor (D-A) types of dipyrido[3,2-a:2',3'-c]phenazine (DPPZ)-based molecules, extended by thienyl and triphenylamino chromophores at the 2,7-(bottom) and/or 10,13-positions (top), have been designed and prepared successfully. Synthetic, structural, thermal, spectral, and computational comparisons have been carried out for related compounds because of their adjustable intramolecular charge-transfer properties. It is noted that a pair of structural isomers (5 and 6) has been obtained, respectively, where distinguishable UV/Vis and fluorescence spectra, electrochemical activity, thermal stability, and bandgaps are observed. Furthermore, compounds 6, 8, 10, 11, 13, and 15 exhibit excellent thermal stability, and the Td10 values for them are found to range from 524 to 646 °C, which can be regarded as one of the best groups of thermally stable compounds among organic small molecules. In addition, theoretical calculations were performed, and the structure-property relationships were examined to reveal the effects of the position and number of donor arms on the DPPZ acceptor core.

Asymmetrical/symmetrical D-π-A/D-π-D thiazole-containing aromatic heterocyclic fluorescent compounds having the same triphenylamino chromophores.

A family of linear asymmetrical D-π-A and symmetrical D-π-D types of thiazole-based aromatic heterocyclic fluorescent compounds bearing various electron-donating and electron-withdrawing tails (bromo, triphenylamino, pyridyl, thienyl and benzoic acid) have been designed and prepared successfully. Synthetic, structural, thermal, spectral and computational comparisons have been carried out for related compounds because of their adjustable electronic properties. It is interesting to mention that compound 2 can be prepared from 5-bromothiazole by one-pot Suzuki-Miyaura coupling and subsequent C-H activation reactions via a 5-TPA-substituted thiazole intermediate 1. X-ray single-crystal structures of six compounds indicate that they all crystallize in the triclinic P1 space group and the thiazole core exhibits different dihedral angles with its adjacent benzene ring of the triphenylamino group (3.6(3)-40.8(3)°). The photophysical and electrochemical results demonstrate that compound 7 exhibits high electrochemical activity with a green fluorescence emission. Meanwhile, compounds 1, 2, and 6 show high luminescence quantum yields, and compound 8 exhibits excellent thermal stability (T(d(10)) = 503 °C).

Ferroelectric switchable behavior through fast reversible de/adsorption of water spirals in a chiral 3D metal-organic framework.

A polar homochiral 3D MOF [{Co2(L)(bpe)(H2O)}·5H2O]n constructed with cobalt(II) and a new ligand N-(1,3-dicarboxy-5-benzyl)-carboxymethylglycine (H4L) accommodates ordered helical water streams in its helical grooves. It provides the first example of switchable ferroelectric and optical behavior through two-step reversible single-crystal to single-crystal transformation (SCSC) upon desorption/adsorption of water spirals and coordinated water molecules, respectively.

Solvent-induced single-crystal-to-single-crystal transformation in multifunctional chiral dysprosium(III) compounds.

Two new enantiomeric ionic chiral dysprosium(III) compounds were designed and synthesized. These compounds show simultaneously the optical activity, ferroelectric effects, nonlinear-optical effects, and slow magnetic relaxation behavior. More interestingly, these compounds exhibit reversible single-crystal-to-single-crystal transformations associated with the release or absorption of solvent molecules. The structure transformations are accompanied by distinct changes in the physical properties.

CpG oligodeoxynucleotide stimulates protective innate immunity against human renal cell carcinoma xenografted in nude mice.

Renal cell carcinoma easily develops metastasis, which is highly resistant to a variety of therapies. Oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODN) are potent activators of innate and adaptive immunity. CpG ODN is inclined to be used as vaccine adjuvant or in combination with other therapies to exert antitumor effect mediated by the adaptive immunity. Herein, we examined the antitumor effect of CpG ODN monotherapy and the role of innate immunity on human RCC Caki-1 cells xenografted in nude mice. Our results indicated that the peritumoral subcutaneous injections of CpG ODN1826 once a week resulted in significant inhibition of the growth of Caki-1 xenografts compared with the control groups, and the survival of tumor-bearing mice were also prolonged significantly. When cytotoxicity of splenic cells from host mice was assessed, it was found that CpG ODN1826 significantly promoted the cytotoxicities of splenocytes targeting primary Caki-1 cells or YAC-1 cells, indicating that the activity of natural killer cells in tumor-bearing nude mice was enhanced by CpG ODN1826 monotherapy. The serum concentrations of interleukin-12 were increased in mice treated with CpG ODN1826. Thus, CpG ODN1826 monotherapy induces significant inhibitory effects on the growth of human RCC xenografted in athymic immunodeficient mice, and the tumor-bearing mice achieves long-term survival, which might be attributed to enhanced innate immunity.

Distinct magnetic dynamic behavior for two polymorphs of the same Dy(III) complex.

Two polymorphs of the same Dy(III) complex show distinct slow magnetic relaxation behaviors due to the different local environments of Dy(III) in the crystal. This work represents the first example where the magnetic dynamic property of neutral rare earth complexes could be tuned by growing polymorphic crystals without changing the ligand.

Microbial production of 1,3-propanediol by Klebsiella pneumoniae XJPD-Li under different aeration strategies.

The microbial production of 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae XJPD-Li under different aeration strategies were investigated. In batch fermentation, the results showed that the final concentration of 1,3-PD and yield on glycerol were 13.44 g/l and 0.73 mol/mol under the anaerobic condition (N2, 0.4 vvm), 11.55 g/l and 0.62 mol/mol without aeration, and 8.73 g/l and 0.47 mol/mol under the aerobic condition (air, 0.4 vvm), respectively. Under the aerobic condition, the yield of 1,3-PD on glycerol was the lowest, while the biomass (optical density at 650 nm) was the highest among these three conditions. In the fed-batch culture, the final concentration and the yield of 1,3-PD was 60.82 g/l and 0.61 mol/mol under the anaerobic condition (N2, 0.4 vvm), 56.43 g/l and 0.53 mol/mol without aeration, and 65.26 g/l and 0.56 mol/mol under the aerobic condition. All these three conditions had good productivities of 1,3-PD, which were 3.35 g/lxh under the anaerobic condition (N2, 0.4 vvm), 3.13 g/lxh without aeration, and 3.16 g/lxh under the aerobic condition within the initial 12 h.