LPAR5 confers radioresistance to cancer cells associated with EMT activation via the ERK/Snail pathway.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is a critical event contributing to more aggressive phenotypes in cancer cells. EMT is frequently activated in radiation-targeted cells during the course of radiotherapy, which often endows cancers with acquired radioresistance. However, the upstream molecules driving the signaling pathways of radiation-induced EMT have not been fully delineated. METHODS: In this study, RNA-seq-based transcriptome analysis was performed to identify the early responsive genes of HeLa cells to γ-ray irradiation. EMT-associated genes were knocked down by siRNA technology or overexpressed in HeLa cells and A549 cells, and the resulting changes in phenotypes of EMT and radiosensitivity were assessed using qPCR and Western blotting analyses, migration assays, colony-forming ability and apoptosis of flow cytometer assays. RESULTS: Through RNA-seq-based transcriptome analysis, we found that LPAR5 is downregulated in the early response of HeLa cells to γ-ray irradiation. Radiation-induced alterations in LPAR5 expression were further revealed to be a bidirectional dynamic process in HeLa and A549 cells, i.e., the early downregulating phase at 2 ~ 4 h and the late upregulating phase at 24 h post-irradiation. Overexpression of LPAR5 prompts EMT programing and migration of cancer cells. Moreover, increased expression of LPAR5 is significantly associated with IR-induced EMT and confers radioresistance to cancer cells. Knockdown of LPAR5 suppressed IR-induced EMT by attenuating the activation of ERK signaling and downstream Snail, MMP1, and MMP9 expression. CONCLUSIONS: LPAR5 is an important upstream regulator of IR-induced EMT that modulates the ERK/Snail pathway. This study provides further insights into understanding the mechanism of radiation-induced EMT and identifies promising targets for improving the effectiveness of cancer radiation therapy.

Macrophages promote growth, migration and epithelial-mesenchymal transition of renal cell carcinoma by regulating GSDMD/IL-1ß axis.

BACKGROUND: Macrophages are highly enriched in renal cell carcinoma, and the inflammatory cytokines secreted by macrophages are remarkably associated with the survival rate of renal cell carcinoma. However, the relationship between gasdermin D (GSDMD) expression driven by macrophage and the invasion of renal cell carcinoma is not clear. METHODS: The Caki-2 and 786-O cells were co-cultured with monocytes cells (THP-1) derived macrophages, then the bio function changes of Caki-2 and 786-O cells and epithelial-mesenchymal transition of cancer cells were detected. Also, the role of IL-1ß in Caki-2 and 786-O cells and macrophage interaction were investigated. Then, the animal model was used to confirm the role of communication of GSDMD with renal cell carcinoma in the tumor microenvironment. RESULTS: CD68 and GSDMD were overexpressed in human renal cell carcinoma. GSDMD contributed to the secretion of IL­1ß in macrophages and was associated with the proliferation rate of renal cell carcinoma cells. Furthermore, silencing GSDMD elicited renal cell carcinoma cells motility through epithelial-mesenchymal transition change. The in vivo study confirmed that GSDMD promoted tumor progression and GSDMD knockout impaired renal cell carcinoma growth and metastases. Finally, the interactions between macrophages and renal cell carcinoma cells promoted renal cell carcinoma proliferation and metastasis, possibly mediated by IL-1ß. CONCLUSION: To our knowledge, this study showed that the GSDMD expressed by macrophages contributed to renal cell carcinoma cell growth, metastases, and epithelial-mesenchymal transition through regulating GSDMD/IL-1ß axis and may be a novel therapeutic target and a potential biomarker for treating and diagnosing renal cell carcinoma.

Upregulation of wild-type p53 by small molecule-induced elevation of NQO1 in non-small cell lung cancer cells.

The tumor suppressor p53 is usually inactivated by somatic mutations in malignant neoplasms, and its reactivation represents an attractive therapeutic strategy for cancers. Here, we reported that a new quinolone compound RYL-687 significantly inhibited non-small cell lung cancer (NSCLC) cells which express wild type (wt) p53, in contract to its much weaker cytotoxicity on cells with mutant p53. RYL-687 upregulated p53 in cells with wt but not mutant p53, and ectopic expression of wt p53 significantly enhanced the anti-NSCLC activity of this compound. RYL-687 induced production of reactive oxygen species (ROS) and upregulation of Nrf2, leading to an elevation of the NAD(P)H:quinoneoxidoreductase-1 (NQO1) that can protect p53 by inhibiting its degradation by 20S proteasome. RYL-687 bound NQO1, facilitating the physical interaction between NQO1 and p53. NQO1 was required for RYL-687-induced p53 accumulation, because silencing of NQO1 by specific siRNA or an NQO1 inhibitor uridine, drastically suppressed RYL-687-induced p53 upregulation. Moreover, a RYL-687-related prodrug significantly inhibited tumor growth in NOD-SCID mice inoculated with NSCLC cells and in a wt p53-NSCLC patient-derived xenograft mouse model. These data indicate that targeting NQO1 is a rational strategy to reactivate p53, and RYL-687 as a p53 stabilizer bears therapeutic potentials in NSCLCs with wt p53.

Transcriptional regulation and small compound targeting of ACE2 in lung epithelial cells.

Angiotensin-converting enzyme 2 (ACE2) is the receptor of COVID-19 pathogen SARS-CoV-2, but the transcription factors (TFs) that regulate the expression of the gene encoding ACE2 (ACE2) have not been systematically dissected. In this study we evaluated TFs that control ACE2 expression, and screened for small molecule compounds that could modulate ACE2 expression to block SARS-CoV-2 from entry into lung epithelial cells. By searching the online datasets we found that 24 TFs might be ACE2 regulators with signal transducer and activator of transcription 3 (Stat3) as the most significant one. In human normal lung tissues, the expression of ACE2 was positively correlated with phosphorylated Stat3 (p-Stat3). We demonstrated that Stat3 bound ACE2 promoter, and controlled its expression in 16HBE cells stimulated with interleukin 6 (IL-6). To screen for medicinal compounds that could modulate ACE2 expression, we conducted luciferase assay using HLF cells transfected with ACE2 promoter-luciferase constructs. Among the 64 compounds tested, 6-O-angeloylplenolin (6-OAP), a sesquiterpene lactone in Chinese medicinal herb Centipeda minima (CM), represented the most potent ACE2 repressor. 6-OAP (2.5 µM) inhibited the interaction between Stat3 protein and ACE2 promoter, thus suppressed ACE2 transcription. 6-OAP (1.25-5 µM) and its parental medicinal herb CM (0.125%-0.5%) dose-dependently downregulated ACE2 in 16HBE and Beas-2B cells; similar results were observed in the lung tissues of mice following administration of 6-OAP or CM for one month. In addition, 6-OAP/CM dose-dependently reduced IL-6 production and downregulated chemokines including CXCL13 and CX3CL1 in 16HBE cells. Moreover, we found that 6-OAP/CM inhibited the entry of SARS-CoV-2 S protein pseudovirus into target cells. These results suggest that 6-OAP/CM are ACE2 inhibitors that may potentially protect lung epithelial cells from SARS-CoV-2 infection.

Biomarkers associated with metastasis and prognosis of lung adenocarcinoma based on microarray data.

We attempted to discover the biomarker associated with metastasis and prognosis of lung adenocarcinoma. The mRNA/lncRNA expression profiles (GSE101836) were downloaded from the publicly available database, which included three highly metastatic and three weakly metastatic samples. The differentially expressed genes and lncRNAs were analyzed and survival analysis were performed based on the TCGA database. The prognosis-associated PPI network and mRNA-lncRNA coexpression network were constructed followed by the function and pathway enrichment analysis. The expression levels of key genes were validated in other datasets. Difference in gender was analyzed. Total 256 differentially expressed genes and 2 lncRNAs were found to be closely related with prognosis. PPI network was constructed with 222 nodes and 1464 edges. Two modules were divided from PPI network. Genes in module A were significantly enriched in cell cycle checkpoint, chromosome segregation, and mitotic cell cycle checkpoint. The module B was closely related with pyridine nucleotide metabolic process, nicotinamide nucleotide metabolic process and carbon metabolism. Coexpression network revealed lncRNA H19 and lncRNA SNHG12 were significant nodes. SNHG12 was closely related with GO:0006260~DNA replication, GO:0055114~oxidation-reduction process and hsa00010: Glycolysis/Gluconeogenesis. H19 was enriched in GO:0006555~methionine metabolic process, and GO:0046655~folic acid metabolic process. The expression levels of TTK and CCNB1 were confirmed in other datasets. The expression of TTK and CCNB1 was significantly higher in the male group than in the female group. TTK, CCNB1 and lncRNA SNHG12 may be the biomarker associated with metastasis and prognosis of lung adenocarcinoma.

19F Magnetic Resonance Activity-Based Sensing Using Paramagnetic Metals.

Fluorine magnetic resonance imaging (19F MRI) is a promising bioimaging technique due to the favorable magnetic resonance properties of the 19F nucleus and the lack of detectable biological background signal. A range of imaging agents have been developed for this imaging modality including small molecule perfluorocarbons, fluorine-rich macromolecules and nanoparticles, and paramagnetic metal-containing agents. Incorporation of paramagnetic metals into fluorinated agents provides a unique opportunity to manipulate relaxation and chemical shift properties of 19F nuclei. Paramagnetic centers will enhance relaxation rates of nearby 19F nuclei through paramagnetic relaxation enhancement (PRE). Further, metals with anisotropic unpaired electrons can induce changes in 19F chemical shift through pseudocontact shift (PCS) effects. PRE and PCS are dependent on the nature of the metal center itself, the molecular scaffold surrounding it, and the position of the 19F nucleus relative to the metal center. One intriguing prospect in 19F magnetic resonance molecular imaging is to design responsive agents that can serve to provide a read out biological activity, including the activity of enzymes, redox activity, the activity of ions, etc. Paramagnetic agents are well suited for this activity-based sensing as metal complexes can be designed to respond to specific biological activities and give a corresponding 19F response that results from changes in the metal complex structure and subsequently PRE/PCS. Broadly speaking, when designing paramagnetic 19F MR biosensors, one can envision that in response to changes in analyte activity, the number of unpaired electrons of the metal changes or the ligand conformation/chemical composition changes. This Account highlights activity-based probes from the Que lab that harness paramagnetic metals to modulate 19F signal. We discuss probes that use conversion from Cu2+ to Cu+ in response to reducing environments to dequench the 19F MR signal. Probes in which oxidants convert Co2+ to Co3+, resulting in chemical shift responses, are also described. Finally, we explore our foray into using Ni2+ coordination switching to furnish probes with different 19F signals when they are converted between 4-coordinate square planar and higher coordination numbers. A major barrier for 19F MR molecular imaging is in vivo application, as signal sensitivity is relatively low, requiring long imaging times to detect imaging agents. Nanoparticle and macromolecular agents show promise due to their higher fluorine density and longer circulation times; however, their analyte scope is limited to analytes that induce cleavage events. A grand challenge for researchers in this area is adapting lessons learned from small molecule paramagnetic probes with promising in vitro activities for the development of probes with enhanced in vivo utility for basic biological and clinical applications.

Copper(II) Pyridyl Aminophenolates: Hypoxia-Selective, Nucleus-Targeting Cytotoxins, and Magnetic Resonance Probes.

Targeting the low-oxygen (hypoxic) environments found in many tumours by using redox-active metal complexes is a strategy that can enhance efficacy and reduce the side effects of chemotherapies. We have developed a series of CuII complexes with tridentate pyridine aminophenolate-based ligands for preferential activation in the reduction window provided by hypoxic tissues. Furthermore, ligand functionalization with a pendant CF3 group provides a 19 F spectroscopic handle for magnetic-resonance studies of redox processes at the metal centre and behaviour in cellular environments. The phenol group in the ligand backbone was substituted at the para position with H, Cl, and NO2 to modulate the reduction potential of the CuII centre, giving a range of values below the window expected for hypoxic tissues. The NO2 -substituted complex, which has the highest reduction potential, showed enhanced cytotoxic selectivity towards HeLa cells grown under hypoxic conditions. Cell death occurs by apoptosis, as determined by analysis of the cell morphology. A combination of 19 F NMR and ICP-OES indicates localization of the NO2 complex in HeLa cell nuclei and increased cellular accumulation under hypoxia. This correlates with DNA nuclease activity being the likely origin of cytotoxic activity, as demonstrated by cleavage of DNA plasmids in the presence of the CuII nitro complex and a reducing agent. Selective detection of the paramagnetic CuII complexes and their diamagnetic ligands by 19 F MRI suggests hypoxia-targeting theranostic applications by redox activation.

Metabolic and transcriptomic analysis of two Cucurbita moschata germplasms throughout fruit development.

BACKGROUND: Pumpkins (Cucurbita moschata; Cucurbitaceae) are valued for their fruits and seeds and are rich in nutrients. Carotenoids and sugar contents, as main feature of pumpkin pulp, are used to determine the fruit quality. RESULTS: Two pumpkin germplasms, CMO-X and CMO-E, were analyzed regarding the essential quality traits such as dry weight, soluble solids, organic acids, carotenoids and sugar contents. For the comparison of fruit development in these two germplasms, fruit transcriptome was analyzed at 5 different developmental stages from 0 d to 40 d in a time course manner. Putative pathways for carotenoids biosynthesis and sucrose metabolism were developed in C. moschata fruit and homologs were identified for each key gene involved in the pathways. Gene expression data was found consistent with the accumulation of metabolites across developmental stages and also between two germplasms. PSY, PDS, ZEP, CRTISO and SUS, SPS, HK, FK were found highly correlated with the accumulation of carotenoids and sucrose metabolites, respectively, at different growth stages of C. moschata as shown by whole transcriptomic analysis. The results of qRT-PCR analysis further confirmed the association of these genes. CONCLUSION: Developmental regulation of the genes associated with the metabolite accumulation can be considered as an important factor for the determination of C. moschata fruit quality. This research will facilitate the investigation of metabolic profiles in other cultivars.

Visible Light Mediated Bidirectional Control over Carbonic Anhydrase Activity in Cells and in Vivo Using Azobenzenesulfonamides.

Two azobenzenesulfonamide molecules with thermally stable cis configurations resulting from fluorination of positions ortho to the azo group are reported that can differentially regulate the activity of carbonic anhydrase in the trans and cis configurations. These fluorinated probes each use two distinct visible wavelengths (520 and 410 or 460 nm) for isomerization with high photoconversion efficiency. Correspondingly, the cis isomer of these systems is highly stable and persistent (as evidenced by structural studies in solid and solution state), permitting regulation of metalloenzyme activity without continuous irradiation. Herein, we use these probes to demonstrate the visible light mediated bidirectional control over the activity of zinc-dependent carbonic anhydrase in solution as an isolated protein, in intact live cells and in vivo in zebrafish during embryo development.

Knockdown of PLOD3 suppresses the malignant progression of renal cell carcinoma via reducing TWIST1 expression.

Procollagen-lysine, 2-oxoglutarate 5-dioxygenase (PLOD3), also known as lysyl hydroxylase 3 (LH3) has been demonstrated to be overexpressed in several kinds of cancers and facilitate cell migration. Currently, we aimed to reveal the role of PLOD3 in renal cell carcinoma (RCC) progression, and explore whether TWIST1 (Twist family bHLH transcription factor 1) is involved in this process. Fifty-eight paired RCC tissues and normal tissues were collected and subjected to qPCR and immunohistochemistry (IHC) technology to detect the expression levels of PLOD3. The clinical value of PLOD3 in predicting RCC progression was then explored. Cell-Counting Kit-8 (CCK-8), wound healing, transwell chambers and tumor-bearing experiments were applied to monitor cell proliferation, migration, invasion and tumorigenesis. Protein levels were determined by using western blotting technology to assess cell apoptosis and epithelial to mesenchymal transition (EMT). PLOD3 expression was enhanced in RCC tissues and cells, which predicted higher T (tumor), N (lymph node) and M (metastasis) stages, histological grade and TNM (tumor, lymph node, metastasis) stage. PLOD3 downregulation in RCC A498 cells obviously inhibited cell proliferation, migration, invasion, EMT and tumorigenesis and increased cell apoptosis. PLOD3 overexpression led to opposite results in RCC A704 cells. PLOD3 downregulation reduced the expression levels of TWIST1, ß-catenin and p-AKT. In addition, TWIST1 overexpression rescued the repressions of cell proliferation, migration, invasion, EMT and the activation of ß-catenin and AKT signaling in addition to apoptosis promotion induced by PLOD3 downregulation. Collectively, this study illustrated that PLOD3 knockdown suppressed RCC malignance via inhibiting TWIST1-mediated activation of ß-catenin and AKT signaling.

Versatile Nickel(II) Scaffolds as Coordination-Induced Spin-State Switches for 19 F Magnetic Resonance-Based Detection.

19 F magnetic resonance (MR) based detection coupled with well-designed inorganic systems shows promise in biological investigations. Two proof-of-concept inorganic probes that exploit a novel mechanism for 19 F MR sensing based on converting from low-spin (S=0) to high-spin (S=1) Ni2+ are reported. Activation of diamagnetic NiL1 and NiL2 by light or ß-galactosidase, respectively, converts them into paramagnetic NiL0 , which displays a single 19 F NMR peak shifted by >35 ppm with accelerated relaxation rates. This spin-state switch is effective for sensing light or enzyme expression in live cells using 19 F MR spectroscopy and imaging that differentiate signals based on chemical shift and relaxation times. This general inorganic scaffold has potential for developing agents that can sense analytes ranging from ions to enzymes, opening up diverse possibilities for 19 F MR based biosensing.

A high-density genetic map developed by specific-locus amplified fragment (SLAF) sequencing and identification of a locus controlling anthocyanin pigmentation in stalk of Zicaitai (Brassica rapa L. ssp. chinensis var. purpurea).

BACKGROUND: Caixin and Zicaitai (Brassica rapa) belong to Southern and Central China respectively. Zicaitai contains high amount of anthocyanin in leaf and stalk resulting to the purple color. Stalk is the major edible part and stalk color is an economically important trait for the two vegetables. The aim of this study is to construct a high density genetic map using the specific length amplified fragment sequencing (SLAF-seq) technique to explore genetic basis for anthocyanin pigmentation traits via quantitative trait loci (QTL) mapping. RESULTS: We constructed a high generation linkage map with a mapping panel of F2 populations derived from 150 individuals of parental lines "Xianghongtai 01" and "Yinong 50D" with purple and green stalk respectively. The map was constructed containing 4253 loci, representing 10,940 single nucleotide polymorphism (SNP) markers spanning 1030.04 centiMorgans (cM) over 10 linkage groups (LGs), with an average distance between markers of 0.27 cM. Quantitative trait loci (QTL) analysis revealed that a major locus on chromosome 7 and 4 minor QTLs explaining 2.69-61.21% of phenotypic variation (PVE) were strongly responsible for variation in stalk color trait. Bioinformatics analysis of the major locus identified 62 protein-coding genes. Among the major locus, there were no biosynthetic genes related to anthocyanin. However, there were several transcription factors like helix-loop-helix (bHLH) bHLH, MYB in the locus. Seven predicted candidate genes were selected for the transcription level analysis. Only bHLH49 transcription factor, was significantly higher expressed in both stalks and young leaves of Xianghongtai01 than Yinong50D. An insertion and deletion (InDel) marker developed from deletion/insertion in the promoter region of bHLH49 showed significant correlation with the stalk color trait in the F2 population. CONCLUSION: Using the constructed high-qualified linkage map, this study successfully identified QTLs for stalk color trait. The identified valuable markers and candidate genes for anthocyanin accumulation in stalk will provide useful information for molecular regulation of anthocyanin biosynthesis. Overall our findings will lay a foundation for functional gene cloning, marker-assisted selection (MAS) and molecular breeding of important economic traits in B. rapa.

Towards Ni(II) complexes with spin switches for 19F MR-based pH sensing.

OBJECTIVES: Our aim was to demonstrate the potential of exploiting simultaneous changes in coordination geometry and spin state in fluorinated Ni(II) complexes as an avenue for 19F magnetic-resonance (MR)-based pH sensing. MATERIALS AND METHODS: Crystal structures were studied using an Agilent Technologies SuperNova Dual Source diffractometer. Solution magnetic moment was determined using Evan's method. MR images were collected on a 7.0-T MR scanner equipped with a quadrature 19F volume coil. RESULTS: NiL1 and NiL2 were synthesized; crystallographic and spectroscopic data supported NiL1 as being diamagnetic and NiL2 as being paramagnetic. In aqueous solution, ligand dissociation from Ni(II) center was observed for both complexes at around pH 6, precluding their use as reversible pH sensors. The two complexes have distinct 19F nuclear magnetic resonance (NMR) signals in terms of both chemical shift and relaxation times, and selective imaging of the two complexes was achieved with no signal interference using two 19F MRI pulse sequences. CONCLUSION: The significant difference in the chemical shift and relaxation times between NiL1 and NiL2 allowed selective imaging of these species using 19F MRI. While NiL1 and NiL2 were not stable to acidic environments, this report lays the framework for development of improved ligand scaffolds that stably coordinate Ni(II) in acidic aqueous solution and act as agents for ratiometric pH mapping by 19F MRI.

19F PARASHIFT Probes for Magnetic Resonance Detection of H2O2 and Peroxidase Activity.

Elevated levels of reactive oxygen species and peroxidase expression are often associated with inflammation and inflammatory diseases. We developed two novel Co(II) complexes that can be used to detect oxidative activity associated with inflammation using 19F magnetic resonance imaging (MRI). These agents display a large change in 19F chemical shift upon oxidation from Co(II) to Co(III), facilitating selective visualization of both species using chemical shift selective pulse sequences. This large chemical shift change is attributed to a large magnetic anisotropy in the high spin Co(II) complexes. Importantly, the differing reactivity of the two agents allows for detection of either H2O2 production and/or the activity of peroxidase enzymes, providing two useful platforms for 19F MR hot spot imaging of oxidative events associated with biological inflammation.

Exosome-packaged miR-1246 contributes to bystander DNA damage by targeting LIG4.

BACKGROUND: An increasing number of studies have recently reported that microRNAs packaged in exosomes contribute to multiple biological processes such as cancer progression; however, little is known about their role in the development of radiation-induced bystander effects. METHODS: The exosomes were isolated from the culture medium of BEP2D cells with or without γ-ray irradiation by ultracentrifugation. To monitor DNA damage and repair efficiency, the DNA double-strand break biomarker 53BP1 foci, comet, micronuclei, expression of DNA repair genes and NHEJ repair activity were detected. The miR-1246 targeting sequence of the DNA ligase 4 (LIG4) mRNA 3'UTR was assessed by luciferase reporter vectors. RESULTS: miR-1246 was increased in exosomes secreted from 2 Gy-irradiated BEP2D cells and inhibited the proliferation of nonirradiated cells. The miR-1246 mimic, exosomes from irradiated cells, and radiation-conditioned cell culture medium increased the yields of 53BP1 foci, comet tail and micronuclei in nonirradiated cells, and decreased NHEJ efficiency. miR-1246 downregulated LIG4 expression by directly targeting its 3'UTR. CONCLUSIONS: Our findings demonstrate that miR-1246 packaged in exosomes could act as a transfer messenger and contribute to DNA damage by directly repressing the LIG4 gene. Exosomal miR-1246 may be a critical predictor of and player in radiation-induced bystander DNA damage.

Connexin 43 Modulates Osteogenic Differentiation of Bone Marrow Stromal Cells Through GSK-3beta/Beta-Catenin Signaling Pathways.

BACKGROUND/AIMS: Bone marrow stromal cells (BMSCs) are multipotent precursors that give rise to osteoblasts, and contribute directly to bone formation. Connexin 43 (Cx43) is the most ubiquitous gap junction protein expressed in bone cell types, and plays crucial roles in regulating intercellular signal transmission for bone development, differentiation and pathology. However, the precise role and mechanism of Cx43 in BMSCs are less known. Here, we investigate the function of Cx43 in osteogenic differentiation of BMSCs in vitro. METHODS: BMSCs were isolated by whole bone marrow adherent culture. Knock down of Cx43 was performed by using lentiviral transduction of Cx43 shRNA. BMSCs were induced to differentiate by culturing in a-MEM, 10% FBS, 50 µM ascorbic acid, 10 mM beta-glycerophosphate, and 100 nM dexamethasone. Alkaline phosphatase (ALP) activity and alizarin red S staining were used to evaluate osteogenic differentiation in calcium nodules. Target mRNAs and proteins were analyzed by using real-time quantitative PCR (qPCR) and western blotting. RESULTS: Cx43 expression markedly increased during osteogenic differentiation. Osteogenic differentiation was suppressed following lentiviral-mediated knockdown of Cx43 expression, as judged by decreased levels of Runt-related transcription factor 2 (Runx2), bone sialoprotein (BSP), osteocalcin (Bglap), Osterix (Osx), alkaline phosphatase (ALP) activity and the number of calcium nodules in response to osteogenic differentiation stimuli. Knock down of Cx43 reduced the level of phosphorylation of GSK-3beta at Ser9 (p-GSK-3beta), resulting in decreased beta-catenin expression and activation. Furthermore, treatment of Cx43-knockdown cells with lithium chloride (LiCl), a GSK-3beta inhibitor, reduced osteogenic differentiation and decreased GSK-3beta levels, as well as partially rescued levels of both total and activated beta-catenin. CONCLUSION: These findings indicate that Cx43 positively modulates osteogenic differentiation of BMSCs by up-regulating GSK-3beta/beta-catenin signaling pathways, suggesting a potential role for Cx43 in determining bone mass and bone mineral density by modulating osteogenesis.

Hypoxia-Responsive 19F MRI Probes with Improved Redox Properties and Biocompatibility.

19F magnetic resonance imaging (MRI), an emerging modality in biomedical imaging, has shown promise for in vitro and in vivo preclinical studies. Here we present a series of fluorinated Cu(II)ATSM derivatives for potential use as 19F magnetic resonance agents for sensing cellular hypoxia. The synthesized complexes feature a hypoxia-targeting Cu2+ coordination core, nine equivalent fluorine atoms connected via a variable-length poly(ethylene glycol) linker. Introduction of the fluorine moiety maintains the planar coordination geometry of the Cu2+ center, while the linker length modulates the Cu2+/+ reduction potential, 19F NMR relaxation properties, and lipophilicity. In particular, the 19F NMR relaxation properties were quantitatively evaluated by the Solomon-Bloembergen model, revealing a regular pattern of relaxation enhancement tuned by the distance between Cu2+ and F atoms. Finally, the potential utility of these complexes for sensing reductive environments was demonstrated using both 19F MR phantom imaging and 19F NMR, including experiments in intact live cells.

Novel penile circumcision suturing devices versus the shang ring for adult male circumcision: a prospective study.

INTRODUCTION: To evaluate the safety and efficacy of a novel penile circumcision suturing devices PCSD and Shang ring (SR) for circumcision in an adult population. MATERIALS AND METHODS: A total of 124 outpatients were randomly assigned to receive PCSD (n=62) or SR (n=62). Patient characteristics, operative time, blood loss, return to normal activities time (RNAT), visual analogue scale (VAS), scar width, wound healing time, cosmetic result, and complications were recorded. RESULTS: There were no significant differences in blood loss, RNAT, or complications between the two groups. There were no significant differences in the VAS scores at theduring operation, and 6 or 24 hours after surgery (P>0.05). The wound scar width was wider in the SR group than in the PCSD group (P<0.01). Patients in the SR group had significantly longer wound healing time compared with those in the PCSD group (P<0.01). Patients who underwent PCSD wereere significantly more satisfied with the cosmetic results (P<0.01). CONCLUSIONS: SR and PCSD are safe and effective minimally invasive techniques for adult male circumcision. Compared with SRs, PCSDs have the advantages of faster postoperative incision healing and a good effect on wound cosmetics.

Exploiting Copper Redox for (19)F Magnetic Resonance-Based Detection of Cellular Hypoxia.

We report a pair of fluorinated, redox-active copper complexes for potential use as (19)F MRI contrast agents for detecting cellular hypoxia. Trifluorinated Cu(II) ATSM-F3 displays the appropriate redox potential for selective accumulation in hypoxic cells and a completely quenched (19)F NMR signal that is "turned on" following reduction to Cu(I). Incubation of cancer cells with CuATSM-F3 resulted in a selective detection of (19)F signal in cells grown under hypoxic conditions.

Cationic sulfonium functionalization renders Znsalens with high fluorescence, good water solubility and tunable cell-permeability.

In this study, we report for the first time that incorporation of cationic sulfonium to the Znsalens skeleton achieves water soluble fluorescent metal complex probes for living cell imaging. To circumvent Znsalen aggregation arising from intermolecular ZnO interactions (found between Zn and the phenoxyl group of another Znsalen molecule), we synthesized a series of sulfonium Znsalens based on alkylation of the 3-thioether or 3,5-dithioether moieties of salicylaldehydes. Such functionalization not only provides positive charge(s) to enhance electrostatic repulsion, but also increases steric hindrance, which renders the Znsalen complex water soluble as a monomeric species in aqueous media as revealed by diffusion ordered NMR spectroscopy (DOSY). More interestingly, these sulfonium Znsalens display "switched on" fluorescence when compared to thioether analogues, which was attributed to the electron-withdrawing sulfonium moiety that perturbs the photoinduced electron transfer (PET) process as suggested by computational calculations based on time-dependent density functional theory (TD-DFT). Most interestingly, live cell imaging experiments showed that modulation of the sulfonium moieties, such as the number or alkyl substituents, significantly tunes the cell-permeability of the fluorescent Znsalens. Thus, this study has demonstrated the importance of sulfonium functionalization on dissociating the intermolecular metal-ligand interactions and thus, modulating water solubility, photophysical properties and even cell-permeability of the fluorophores, which provides a new approach to the design of functional metal complexes for biological studies.