Identification of KU-55933 as an anti-atherosclerosis compound by using a hemodynamic-based high-throughput drug screening platform.

Several compounds have been used for atherosclerosis treatment, including clinical trials; however, no anti-atherosclerotic drugs based on hemodynamic force-mediated atherogenesis have been discovered. Our previous studies demonstrated that "small mothers against decapentaplegic homolog 1/5" (Smad1/5) is a convergent signaling molecule for chemical [e.g., bone morphogenetic proteins (BMPs)] and mechanical (e.g., disturbed flow) stimulations and hence may serve as a promising hemodynamic-based target for anti-atherosclerosis drug development. The goal of this study was to develop a high-throughput screening (HTS) platform to identify potential compounds that can inhibit disturbed flow- and BMP-induced Smad1/5 activation and atherosclerosis. Through HTS using a Smad1/5 downstream target inhibitor of DNA binding 1 (Id-1) as a luciferase reporter, we demonstrated that KU-55933 and Apicidin suppressed Id-1 expression in AD-293 cells. KU-55933 (10 µM), Apicidin (10 µM), and the combination of half doses of each [1/2(K + A)] inhibited disturbed flow- and BMP4-induced Smad1/5 activation in human vascular endothelial cells (ECs). KU-55933, Apicidin, and 1/2(K + A) treatments caused 50.6%, 47.4%, and 73.3% inhibitions of EC proliferation induced by disturbed flow, respectively, whereas EC inflammation was only suppressed by KU-55933 and 1/2(K + A), but not Apicidin alone. Administrations of KU-55933 and 1/2(K + A) to apolipoprotein E-deficient mice inhibited Smad1/5 activation in ECs in athero-susceptible regions, thereby suppressing endothelial proliferation and inflammation, with the attenuation of atherosclerotic lesions in these mice. A unique drug screening platform has been developed to demonstrate that KU-55933 and its combination with Apicidin are promising therapeutic compounds for atherosclerosis based on hemodynamic considerations.

Vinculin phosphorylation impairs vascular endothelial junctions promoting atherosclerosis.

BACKGROUND AND AIMS: Atherosclerosis preferentially develops in arterial branches and curvatures where vascular endothelium is exposed to disturbed flow. In this study, the effects of disturbed flow on the regulation of vascular endothelial phosphoproteins and their contribution to therapeutic application in atherogenesis were elucidated. METHODS: Porcine models, large-scale phosphoproteomics, transgenic mice, and clinical specimens were used to discover novel site-specific phosphorylation alterations induced by disturbed flow in endothelial cells (ECs). RESULTS: A large-scale phosphoproteomics analysis of native endothelium from disturbed (athero-susceptible) vs. pulsatile flow (athero-resistant) regions of porcine aortas led to the identification of a novel atherosclerosis-related phosphoprotein vinculin (VCL) with disturbed flow-induced phosphorylation at serine 721 (VCLS721p). The induction of VCLS721p was mediated by G-protein-coupled receptor kinase 2 (GRK2)S29p and resulted in an inactive form of VCL with a closed conformation, leading to the VE-cadherin/catenin complex disruption to enhance endothelial permeability and atherogenesis. The generation of novel apolipoprotein E-deficient (ApoE-/-) mice overexpressing S721-non-phosphorylatable VCL mutant in ECs confirmed the critical role of VCLS721p in promoting atherosclerosis. The administration of a GRK2 inhibitor to ApoE-/- mice suppressed plaque formation by inhibiting endothelial VCLS721p. Studies on clinical specimens from patients with coronary artery disease (CAD) revealed that endothelial VCLS721p is a critical clinicopathological biomarker for atherosclerosis progression and that serum VCLS721p level is a promising biomarker for CAD diagnosis. CONCLUSIONS: The findings of this study indicate that endothelial VCLS721p is a valuable hemodynamic-based target for clinical assessment and treatment of vascular disorders resulting from atherosclerosis.

Endothelial Yin Yang 1 Phosphorylation at S118 Induces Atherosclerosis Under Flow.

RATIONALE: Disturbed flow occurring in arterial branches and curvatures induces vascular endothelial cell (EC) dysfunction and atherosclerosis. We postulated that disturbed flow plays important role in modulating phosphoprotein expression profiles to regulate endothelial functions and atherogenesis. OBJECTIVE: The goal of this study is to discover novel site-specific phosphorylation alterations induced by disturbed flow in ECs to contribute to atherosclerosis. METHODS AND RESULTS: Quantitative phosphoproteomics analysis of ECs exposed to disturbed flow with low and oscillatory shear stress (0.5±4 dynes/cm2) versus pulsatile shear stress (12±4 dynes/cm2) revealed that oscillatory shear stress induces phospho-YY1S118 (serine [S]118 phosphorylation of Yin Yang 1) in ECs. Elevated phospho-YY1S118 level in ECs was further confirmed to be present in the disturbed flow regions in experimental animals and human atherosclerotic arteries. This disturbed flow-induced EC phospho-YY1S118 is mediated by CK2α (casein kinase 2α) through its direct interaction with YY1. Yeast 2-hybrid library screening and in situ proximity ligation assays demonstrate that phospho-YY1S118 directly binds ZKSCAN4 (zinc finger with KRAB [krüppel-associated box] and SCAN [SRE-ZBP, CTfin51, AW-1 and Number 18 cDNA] domains 4) to induce promoter activity and gene expression of HDM2 (human double minute 2), which consequently induces EC proliferation through downregulation of p53 and p21CIP1. Administration of apoE-deficient (ApoE-/-) mice with CK2-specific inhibitor tetrabromocinnamic acid or atorvastatin inhibits atherosclerosis formation through downregulations of EC phospho-YY1S118 and HDM2. Generation of novel transgenic mice bearing EC-specific overexpression of S118-nonphosphorylatable mutant of YY1 in ApoE-/- mice confirms the critical role of phospho-YY1S118 in promoting atherosclerosis through EC HDM2. CONCLUSIONS: Our findings provide new insights into the mechanisms by which disturbed flow induces endothelial phospho-YY1S118 to promote atherosclerosis, thus indicating phospho-YY1S118 as a potential molecular target for atherosclerosis treatment.

Pursuing the Precision Study for Color Glass Condensate in Forward Hadron Productions.

With the tremendous accomplishments of RHIC and the LHC experiments and the advent of the future electron-ion collider on the horizon, the quest for compelling evidence of the color glass condensate (CGC) has become one of the most aspiring goals in the high energy quantum chromodynamics research. Pursuing this question requires developing the precision test of the CGC formalism. By systematically implementing the threshold resummation, we significantly improve the stability of the next-to-leading-order calculation in CGC for forward rapidity hadron productions in pp and pA collisions, especially in the high p_{T} region, and obtain reliable descriptions of all existing data measured at RHIC and the LHC across all p_{T} regions. Consequently, this technique can pave the way for the precision studies of the CGC next-to-leading-order predictions by confronting them with a large amount of precise data.

Alar Rim Triangular Flap for Congenital Nasal Cleft Repair in Pediatric Patients.

BACKGROUND: According to Tessier classification, number 1 and number 2 craniofacial clefts involve the nasal ala. Congenital nasal cleft is not common and is difficult for reconstruction. Notches in the medial one-third of either nasal ala are typical manifestations in these patients. Herein, we introduce a alar rim triangular flap, which is indeed a local flap, for the treatment of isolated nasal cleft due to congenital deformities in pediatric patients. METHODS: The authors conducted a retrospective cohort study including 10 consecutive pediatric patients undergoing this surgery. This alar rim triangular flap including 2 triangles was existing nasal tissue near the cleft. The alar rim defect was covered through local tissue re-arrangement. The authors reviewed the photographs and clinical medical notes of these patients carefully. Self-reported satisfactions of patients (or children's parents) with the scar morphology and correction effect of this procedure were evaluated as well at postoperative every follow-up. RESULTS: All the cases were followed up regularly, and the average follow-up time was 22 months (ranged from 13-38 months). All the nasal clefts were reconstructed successfully. The alar rim triangular flap survived with no flap loss. The wound created by this procedure healed primarily. No alar retraction, nasal obstruction or step-off deformities were observed during postoperative follow-up. There were no patients unsatisfied with the outcome of the scar morphology and correction effect of this operation. CONCLUSIONS: The newly designed alar rim triangular flap in this study can be an alternative treatment for correcting isolated congenital nasal cleft with optimal clinical outcome. LEVEL OF EVIDENCE: Level 4.

Steady semiconducting properties of monolayer PtSe2 with non-metal atom and transition metal atom doping.

Based on density functional theory, the electronic structure and magnetic properties of monolayer PtSe2 doped with different atoms were studied. The Pt and Se atoms are replaced by a transition metal atom (Mn) and a non-metal atom X (X = N, P, As), respectively. The pristine monolayer PtSe2 is a semiconductor with an indirect band gap of 1.352 eV. For one non-metal atom doping, the doped system exhibits indirect band gap magnetic semiconducting properties and the magnetic moment is less than 1 µB and mainly comes from the hybridization of Pt-5d and X-p orbitals. The N-Doped system still retains the magnetic semiconducting properties under strain (from -10% to 13%) and the band gap varies from 0.059 eV to 1.308 eV. For two X doped systems, three different configurations are considered. The doped systems retain the indirect band gap semiconducting properties except for the third nearest neighbor N-doped system (direct band gap). But, for all N-doped and the second nearest neighbor P-doped systems, the magnetic moment increases to more than double. Meanwhile, all X-doped monolayer PtSe2 systems exhibit p-type semiconducting characteristics. For (Mn, X) co-doped systems, the magnetic moments are mainly localized in the Mn 3d orbital and there is strong p-d hybridization between Mn atoms and X atoms. The (Mn, N/P) co-doped system still exhibits magnetic semiconducting properties. These results are important for designing semiconductor devices and electronic spin devices based on monolayer PtSe2.

Correction of Severe Short Nose Using a Costal Cartilage Extension Framework.

BACKGROUND: Various techniques for the aesthetic correction of short noses have been described, but the selection of the adequate graft material remains controversial. Previous reports have mainly focused on the application of septal cartilage or alloplastic materials for short nose elongation, but the lengthening effect is often unsatisfactory for severe short noses. We propose costal cartilage as an alternative treatment for short noses, describe the technique, and discuss outcomes, patient selection, and complications based on our 15-year experience. METHODS: From February 2004 to December 2018, 611 patients with varying degrees of short noses were included in this retrospective study. All patients underwent nose elongation surgery using a costal cartilage graft. Nasal length before and after surgery was measured based on a 3-dimensional simulation technology. Outcomes and complications including possible underlying reasons were analyzed. Patient satisfaction was evaluated using a self-assessment survey. RESULTS: Nasal elongation using costal cartilage was successfully achieved, with a mean increase in nasal length of 4.06 ±0.79 mm. Patients were followed up for a period of 8.5 months on average, ranging from 6 months to 8 years. Follow-up examinations demonstrated stable results. The overall complication rate was 3.8%. Complications included infection, implant extrusion, migration, deviation, visibility, prominence, and reddening of the nasal skin. Most patients (95.2%) rated their outcome as improved and much improved. CONCLUSION: Nasal elongation using costal cartilage grafting is an effective therapeutic approach for patients with severe short noses. Reliable outcomes and the use of autologous tissue along with minimal donor site morbidity contribute to the high patient acceptance. Meticulous surgical technique and careful patient selection are prerequisites for successful results.

Efficacy and Safety of Subcutaneous Temporal Autologous Micro-fat Augmentation.

BACKGROUND: Autologous fat grafting is a rapidly developing soft tissue filling technique that has been playing an increasingly important role in facial contouring and rejuvenation surgeries. However, this technique is accompanied by many side effects and risks. In particular, there is still much room for improvement in regard to the surgical method of temporal augmentation with autologous fat, which is highly popular among Chinese people. Better surgical methods can achieve better outcomes while curbing surgical risks. DESIGN AND METHODOLOGY: We reviewed 39 patients who consecutively underwent subcutaneous temporal autologous micro-fat argumentation surgery at Peking University People's Hospital from February 19, 2016, to May 13, 2019, to correct temporal hollowness. Each patient's Visual Analogue Scale (VAS) satisfaction score and Hollowness Severity Rating Scale (HSRS) score before and after surgery were precisely recorded, and any complaints about perioperative complications were meticulously collected to assess the efficacy and safety profile of the novel technique. RESULTS: All 39 patients included in this study were female. We performed 86 subcutaneous temporal autologous micro-fat argumentation surgeries, with an average follow-up of 20.4 ± 9.6 months. The average fat filling volume in the right temporal region was 6.29 ± 2.55 mL, and that in the left temporal region was 6.34 ± 2.71 mL. The average VAS satisfaction score increased from 4.44 ± 1.33 before the surgery to 8.08 ± 0.77 after the surgery, and the average HSRS score dropped from 1.82 ± 0.72 before the surgery to 0.36 ± 0.49 after the surgery. Four patients were encountered with minor complications of intraoperative bleeding and congestion, which were all completely ameliorated after conservative therapies. CONCLUSION: In the present study, we found that the reported surgical method of subcutaneous temporal autologous micro-fat augmentation successfully improved the temporal hollowness of the patients, boasting good surgical results and high patient satisfaction with minimal short- and long-term complications, illustrating that it is an effective, safe and promising novel surgical technique worthy of wider clinical application. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Elliptic Flow of Heavy Quarkonia in pA Collisions.

Using the dilute-dense factorization in the color glass condensate framework, we investigate the azimuthal angular correlation between a heavy quarkonium and a charged light hadron in proton-nucleus collisions. We extract the second harmonic v_{2}, commonly known as the elliptic flow, with the light hadron as the reference. This particular azimuthal angular correlation between a heavy meson and a light hadron was first measured at the LHC recently. The experimental results indicate that the elliptic flows for heavy flavor mesons (J/ψ and D^{0}) are almost as large as those for light hadrons. Our calculation demonstrates that this result can be naturally interpreted as an initial state effect due to the interaction between the incoming partons from the proton and the dense gluons inside the target nucleus. Since the heavy quarkonium v_{2} exhibits a weak mass dependence according to our calculation, we predict that the heavy quarkonium ϒ should have a similar elliptic flow as compared to that of the J/ψ, which can be tested in future measurements.

Differential regulations of fibronectin and laminin in Smad2 activation in vascular endothelial cells in response to disturbed flow.

BACKGROUND: Atherosclerosis occurs in arterial curvatures and branches, where the flow is disturbed with low and oscillatory shear stress (OSS). The remodeling and alterations of extracellular matrices (ECMs) and their composition is the critical step in atherogenesis. In this study, we investigated the effects of different ECM proteins on the regulation of mechanotransduction in vascular endothelial cells (ECs) in response to OSS. METHODS: Through the experiments ranging from in vitro cell culture studies on effects of OSS on molecular signaling to in vivo examinations on clinical specimens from patients with coronary artery disease (CAD), we elucidated the roles of integrins and different ECMs, i.e., fibronectin (FN) and laminin (LM), in transforming growth factor (TGF)-ß receptor (TßR)-mediated Smad2 activation and nuclear factor-κB (NF-κB) signaling in ECs in response to OSS and hence atherogenesis. RESULTS: OSS at 0.5±12 dynes/cm2 induces sustained increases in the association of types I and II TßRs with ß1 and ß3 integrins in ECs grown on FN, but it only transient increases in ECs grown on LM. OSS induces a sustained activation of Smad2 in ECs on FN, but only a transient activation of Smad2 in ECs on LM. OSS-activation of Smad2 in ECs on FN regulates downstream NF-κB signaling and pro-inflammatory gene expression through the activation of ß1 integrin and its association with TßRs. In contrast, OSS induces transient activations of ß1 and ß3 integrins in ECs on LM, which associate with type I TßR to regulate Smad2 phosphorylation, resulting in transient induction of NF-κB and pro-inflammatory gene expression. In vivo investigations on diseased human coronary arteries from CAD patients revealed that Smad2 is highly activated in ECs of atherosclerotic lesions, which is accompanied by the concomitant increase of FN rather than LM in the EC layer and neointimal region of atherosclerotic lesions. CONCLUSIONS: Our findings provide new insights into the mechanisms of how OSS regulates Smad2 signaling and pro-inflammatory genes through the complex signaling networks of integrins, TßRs, and ECMs, thus illustrating the molecular basis of regional pro-inflammatory activation within disturbed flow regions in the arterial tree.

Autologous Buccal Micro-Mucosa Free Graft combined with Posterior Scrotal Flap Transfer for Vaginoplasty in Male-To-Female Transsexuals: A Pilot Study.

BACKGROUND: The inverted peno-scrotal flap method is considered the standard method of vaginoplasty in male-to-female genital reassignment surgery. Though with numerous advantages, the method has its limitations regarding skin texture, lack of inherent lubrication, and that the tissues for creating the labia depend on the amount of tissues remaining after vaginoplasty. Our purpose was to describe the procedure and outcome of vaginoplasty applying a new technique: autologous buccal micro-mucosa free graft combined with posterior scrotal flap transfer, which could solve some of the problems the previous methods had. METHODS: Nine male-to-female transsexual patients received our new method of vaginoplasty from July 2010-October 2015. We described the details of the surgical procedure and evaluated the long-term anatomical and functional outcomes. RESULTS: In a mean clinical follow-up period of 25.3 months and phone interview follow-up of 50.3 months, we observed that the neovaginas in the nine cases were all of sufficient volume, lined with mucosa, with natural mucosal discharge. The oral donor sites resulted in no visible scars or malfunction. Eight patients experienced uneventful postoperative periods, while one patient suffered from scrotal flap prolapse. All the patients were sexually active and reported sexual satisfaction, with no need of lubrication. CONCLUSION: The reported technique achieves the outcomes of creating a neovagina of sufficient volume, without serious stenosis in long-term follow-up. The neovagina is lined with mucosa and has appropriate lubrication as well as good sexual sensation. The reported method is easy and economical to perform and retains enough tissues for vulvoplasty to achieve a superior cosmetic appearance, with rare risk of complications and donor area malfunction. Additionally, this technique is feasible and advantageous to the patients who have insufficient peno-scrotal skin for neovaginal lining as well as those with unfavorable previous vaginoplasty. All of these indicate that this technique is a promising option for vaginoplasty in male-to-female transsexual surgery. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Influences of the adsorption of different elements on the electronic structures of a tin sulfide monolayer.

Based on first-principles calculations, we investigated the adsorption energy, structural parameters, and electronic and magnetic properties for the adsorption of different atoms, including light metals, hydrogen, oxygen, and 3D transition metals (TM) adatoms, on a tin sulfide (SnS) monolayer. The results showed that Li- and Al-atom adsorption can effectively induce n-type carriers, whereas O atom adsorption can produce p-type doping in the SnS monolayer. In addition, except for Ni atoms, the other adatoms can induce magnetism in the SnS monolayer. Moreover, for Fe- and Co-atom adsorption, the occupied and unoccupied states belong to the same spin-channel. These results indicate that surface adsorption is an effective method to tune the electronic structures of the SnS monolayer.

Regulation of nuclear translocation of the Myb1 transcription factor by TvCyclophilin 1 in the protozoan parasite Trichomonas vaginalis.

In Trichomonas vaginalis, a Myb1 protein was previously demonstrated to repress transcription of an iron-inducible ap65-1 gene. In this study, a human cyclophilin A homologue, TvCyclophilin 1 (TvCyP1), was identified as a Myb1-binding protein using a bacterial two-hybrid library screening system. The recombinant TvCyP1 exhibited typical peptidyl-prolyl isomerase activity with kcat/Km of ∼7.1 µm(-1) s(-1). In a pulldown assay, the His-tagged Myb1 interacted with a GST-TvCyP1 fusion protein, which had an enzymatic proficiency half that of recombinant TvCyP1. Both the enzymatic proficiency of GST-TvCyP1 and its binding to His-Myb1 were eliminated by mutation of Arg(63) in the catalytic motif or inhibited by cyclosporin A. TvCyP1 was primarily localized to the hydrogenosomes by immunofluorescence assay, but it was also co-purified with Myb1 in certain vesicle fractions from differential and gradient centrifugations. Transgenic cells overexpressing HA-TvCyP1 had a higher level of nuclear Myb1 but a much lower level of Myb1 associated with the vesicles than control and those overexpressing HA-TvCyP1(R63A). Myb1 was detected at a much higher level in the HA-TvCyP1 protein complex than in the HA-TvCyP1(R63A) protein complex immunoprecipitated from P15 and P100, but not S100, fractions of postnuclear lysates. A TvCyP1-binding motif, (105)YGPKWNK(111), was identified in Myb1 in which Gly(106) and Pro(107) were essential for its binding to TvCyP1. Mutation of Gly(106) and Pro(107), respectively, in HA-Myb1 resulted in cytoplasmic retention and elevated nuclear translocation of the overexpressed protein. These results suggest that TvCyP1 may induce the release of Myb1 that is restrained to certain cytoplasmic vesicles prior to its nuclear translocation.

Force-specific activation of Smad1/5 regulates vascular endothelial cell cycle progression in response to disturbed flow.

Vascular endothelial cells (ECs) are constantly exposed to blood flow-induced shear stress, but the mechanism of force-specific activation of their signaling to modulate cellular function remains unclear. We have demonstrated that bone morphogenetic protein receptor (BMPR)-specific Smad1/5 can be force-specifically activated by oscillatory shear stress (OSS) in ECs to cause cell cycle progression. Smad1/5 is highly activated in ECs of atherosclerotic lesions in diseased human coronary arteries from patients with end-stage heart failure undergoing heart transplantation and from apolipoprotein E-deficient mice. Application of OSS (0.5 ± 4 dyn/cm(2)) causes the sustained activation of Smad1/5 in ECs through activations of mammalian target of rapamycin and p70S6 kinase, leading to up-regulation of cyclin A and down-regulations of p21(CIP1) and p27(KIP1) and, hence, EC cycle progression. En face examination of rat aortas reveals high levels of phospho-Smad1/5 in ECs of the inner, but not the outer, curvature of aortic arch, nor the straight segment of thoracic aorta [corrected]. Immunohistochemical and en face examinations of the experimentally stenosed abdominal aorta in rats show high levels of phospho-Smad1/5 in ECs at poststenotic sites, where OSS occurs. These OSS activations of EC Smad1/5 in vitro and in vivo are not inhibited by the BMP-specific antagonist Noggin and, hence, are independent of BMP ligand. Transfecting ECs with Smad1/5-specific small interfering RNAs inhibits the OSS-induced EC cycle progression. Our findings demonstrate the force-specificity of the activation of Smad1/5 and its contribution to cell cycle progression in ECs induced by disturbed flow.

Aesthetic Labia Minora Reduction with Combined Wedge-edge Resection: A Modified Approach of Labiaplasty.

BACKGROUND: Nowadays, the demand for female genital rejuvenation procedures especially for labiaplasty is surging. Labia minora reduction has been the most practiced esthetic procedure for the female genitalia in China. Gynecological plastic surgeons have proposed several methods for labia reduction, but there is no consensus on which one is the best choice. Patients often receive re-operations for inadequate resection and asymmetry with existing methods. Here we present a modified method of labiaplasty combined wedge and edge resection and to discuss the appropriate indications of this method. METHODS: From January 2009 to March 2014, we performed 524 labia esthetic surgeries. The methods we used mainly include simple edge resection, wedge resection, modified de-epithelialization, and the combined method discussed in this article. Forty-nine patients aged from 25 to 45 years were selected to receive combined wedge-edge labial resection and were retrospectively reviewed. Patients were required to come back for follow-up assessment at 1 and 6 months. RESULTS: Twenty-one of forty-nine (42.9 %) patients underwent unilateral labial reduction. The average time for the procedures was 56 min. The mean follow-up was 4.5 months. All the surgeries were successfully performed and 47 patients experienced an uneventful postoperative period. A minor dehiscence occurred in two patients. One of the patients received a revision surgery correcting a postoperative asymmetry malformation. Finally, all the patients were satisfied with the esthetic appearance. CONCLUSION: The combined wedge-edge reduction of the labia minora is a simple and safe method associated with high satisfaction and a low complication rate. Therefore, we propose this combined procedure for bi-dimensional and/or unilateral hypertrophied labia minora especially in those who require removal of the dark margin of the labia.

Mechanical regulation of cancer cell apoptosis and autophagy: roles of bone morphogenetic protein receptor, Smad1/5, and p38 MAPK.

Mechanical forces induced by interstitial fluid flow in and surrounding tissues and by blood/lymphatic flow in vessels may modulate cancer cell invasion and metastasis and anticancer drug delivery. Our previous study demonstrated that laminar flow-induced shear stress induces G2/M arrest in tumor cells. However, whether shear stress modulates final cell fate remains unclear. In this study, we investigated the role of flow-induced shear stress in modulating the survival of four human tumor cell lines, i.e., Hep3B hepatocarcinoma cells, MG63 osteosarcoma cells, SCC25 oral squamous carcinoma cells, and A549 carcinomic alveolar basal epithelial cells. Laminar shear stress (LSS) ranging from 0.5 to 12dyn/cm(2) induced death of these four tumor cell lines. In contrast to LSS at 0.5dyn/cm(2), oscillatory shear stress (OSS) at 0.5±4dyn/cm(2) cannot induce cancer cell death. Both LSS and OSS had no effect on human normal hepatocyte, lung epithelial, and endothelial cells. Application of LSS to these four cell lines increased the percentage of cells stained positively for annexin V-FITC, with up-regulations of cleaved caspase-8, -9, and -3, and PARP. In addition, LSS also induced Hep3B cell autophagy, as detected by acidic vesicular organelle formation, LC3B transformation, and p62/SQSTM1 degradation. By transfecting with small interfering RNA, we found that the shear-induced apoptosis and autophagy are mediated by bone morphogenetic protein receptor type (BMPR)-IB, BMPR-specific Smad1 and Smad5, and p38 mitogen-activated protein kinase in Hep3B cells. Our findings provide insights into the molecular mechanisms by which shear stress induces apoptosis and autophagy in tumor cells.

Differential adhesion and actomyosin cable collaborate to drive Echinoid-mediated cell sorting.

Cell sorting involves the segregation of two cell populations into `immiscible' adjacent tissues with smooth borders. Echinoid (Ed), a nectin ortholog, is an adherens junction protein in Drosophila, and cells mutant for ed sort out from the surrounding wild-type cells. However, it remains unknown which factors trigger cell sorting. Here, we dissect the sequence of this process and find that cell sorting occurs when differential expression of Ed triggers the assembly of actomyosin cable. Conversely, Ed-mediated cell sorting can be rescued by recruitment of Ed, via homophilic or heterophilic interactions, to the wild-type cell side of the clonal interface, even when differential Ed expression persists. We found, unexpectedly, that when actomyosin cable was largely absent, differential adhesion was sufficient to cause limited cell segregation but with a jagged tissue border (imperfect sorting). We propose that Ed-mediated cell sorting is driven both by differential Ed adhesion that induces cell segregation with a jagged border and by actomyosin cable assembly at the interface that smoothens this border.

Characteristics of p-type Mg-doped GaS and GaSe nanosheets.

The characteristics are investigated in the p-type Mg-doped GaS and GaSe nanosheets by means of first-principles calculations, showing that with increasing Mg doping concentration, the formation energy increases while the transition level decreases. Moreover, Mg impurity can create a shallower acceptor level in the GaSe nanosheet than in the GaS nanosheet. In particular, the transition level is 39.3 meV when Mg doping concentration is 0.056 in the GaSe nanosheets, which indicates that Mg impurity can offer effective p-type carriers in the GaSe nanosheets.

The characteristics of n- and p-type dopants in SnS2 monolayer nanosheets.

Based on density functional theory, the characteristics of n- and p-type impurities are investigated firstly by means of group V and VII atoms substituting sulfur atoms in the SnS2 monolayer nanosheets. Numerical results show that the formation energy and transition levels depend highly on the atomic size and electronegativity of the impurity atom. The formation energies increase with the increasing impurity atom size for each considered doping case. For group V atom-doped SnS2 monolayer nanosheet systems, the calculations of the transition level indicate that N, P or As doping is not effective for p-type conductivity. However, for group VII atom doping cases, F, Cl, Br and I impurities can offer effective n-type carriers in the SnS2 monolayer nanosheets.

Structure of the Trichomonas vaginalis Myb3 DNA-binding domain bound to a promoter sequence reveals a unique C-terminal ß-hairpin conformation.

Trichomonas vaginalis Myb3 transcription factor (tvMyb3) recognizes the MRE-1 promoter sequence and regulates ap65-1 gene, which encodes a hydrogenosomal malic enzyme that may play a role in the cytoadherence of the parasite. Here, we identified tvMyb3(53-180) as the essential fragment for DNA recognition and report the crystal structure of tvMyb3(53-180) bound to MRE-1 DNA. The N-terminal fragment adopts the classical conformation of an Myb DNA-binding domain, with the third helices of R2 and R3 motifs intercalating in the major groove of DNA. The C-terminal extension forms a ß-hairpin followed by a flexible tail, which is stabilized by several interactions with the R3 motif and is not observed in other Myb proteins. Interestingly, this unique C-terminal fragment does not stably connect with DNA in the complex structure but is involved in DNA binding, as demonstrated by NMR chemical shift perturbation, (1)H-(15)N heteronuclear-nuclear Overhauser effect and intermolecular paramagnetic relaxation enhancement. Site-directed mutagenesis also revealed that this C-terminal fragment is crucial for DNA binding, especially the residue Arg(153) and the fragment K(170)KRK(173). We provide a structural basis for MRE-1 DNA recognition and suggest a possible post-translational regulation of tvMyb3 protein.