Dual-responsive near-infrared turn-on fluorescent probe for cancer stem cell-specific visualization.

Aldehyde dehydrogenase 1A1 (ALDH1A1) stands out as one of the most reliable intracellular biomarkers for stem cells because it is expressed in both cancer stem cells (CSCs) and normal somatic stem cells (NSCs). Although several turn-on fluorescent probes for ALDH1A1 have been developed to visualize CSCs in cancer cells, the discrimination of CSCs from NSCs is difficult. We here report an AND-type dual-responsive fluorescent probe, CHO_ßgal, the near-infrared fluorescence of which can be turned on after responding to both ALDH1A1 and ß-galactosidase. The AND-type dual responsiveness enables CSCs to be clearly visualized, whereas NSCs are non-emissive in microscopy. CSC-positive metastasis model lungs were successfully discriminated from normal lungs in ex vivo staining experiments using CHO_ßgal, whereas the single-input ALDH1A1-responsive probe failed to achieve this discrimination owing to pronounced false-positive fluorescence output from lung NSCs. In tissue slice staining experiments, even in the presence of adjacent normal tissues, the peripheral region-specific localization of CSCs was clear. The versatility of CHO_ßgal holds promise not only as a fundamental in vitro research tool for visualizing CSCs but also as a valuable asset in practical tissue staining diagnosis, significantly contributing to the assessment of cancer malignancy.

A novel transient receptor potential C3/C6 selective activator induces the cellular uptake of antisense oligonucleotides.

Antisense oligonucleotide (ASO) therapy is a novel therapeutic approach in which ASO specifically binds target mRNA, resulting in mRNA degradation; however, cellular uptake of ASOs remains critically low, warranting improvement. Transient receptor potential canonical (TRPC) channels regulate Ca2+ influx and are activated upon stimulation by phospholipase C-generated diacylglycerol. Herein, we report that a novel TRPC3/C6/C7 activator, L687, can induce cellular ASO uptake. L687-induced ASO uptake was enhanced in a dose- and incubation-time-dependent manner. L687 enhanced the knockdown activity of various ASOs both in vitro and in vivo. Notably, suppression of TRPC3/C6 by specific siRNAs reduced ASO uptake in A549 cells. Application of BAPTA-AM, a Ca2+ chelator, and SKF96365, a TRPC3/C6 inhibitor, suppressed Ca2+ influx via TRPC3/C6, resulting in reduced ASO uptake, thereby suggesting that Ca2+ influx via TRPC3/C6 is critical for L687-mediated increased ASO uptake. L687 also induced dextran uptake, indicating that L687 increased endocytosis. Adding ASO to L687 resulted in endosome accumulation; however, the endosomal membrane disruptor UNC7938 facilitated endosomal escape and enhanced knockdown activity. We discovered a new function for TRPC activators regarding ASO trafficking in target cells. Our findings provide an opportunity to formulate an innovative drug delivery system for the therapeutic development of ASO.

Deep-Red/Near-Infrared Turn-On Fluorescence Probes for Aldehyde Dehydrogenase 1A1 in Cancer Stem Cells.

Accumulating evidence supports that cancer stem cells (CSCs) are responsible for cancer proliferation, metastasis, and therapy resistance; therefore, an effective strategy to identify and isolate CSCs is required urgently. Because of their low invasiveness and high signal/noise ratio, "turn-on" fluorescence probes working in the deep-red/near-infrared (DR/NIR) region are one of the most attractive yet undeveloped tools for CSC detection. Herein, we report DR/NIR turn-on fluorescence probes, CS5-A and CS7-A, targeted to aldehyde dehydrogenase 1A1 as an intracellular CSC marker. In contrast to the conventional "always-on" green-fluorescent ALDEFLUOR, we succeeded in generating high-contrast (signal/noise ratio > 8.3) and wash-free in vitro CSC imaging with the DR probe C5S-A. This probe can facilitate CSC isolation with minimal contamination by autofluorescence from other tissues through fluorescence-activated cell sorting. Furthermore, the NIR absorbance/emission and turn-on properties of C7S-A allow simple and rapid CSC detection in vivo within 15 min.

Topical Application of BMS-509744, a Selective Inhibitor of Interleukin-2-Inducible T Cell Kinase, Ameliorates Imiquimod-Induced Skin Inflammation in Mice.

Psoriasis is an immune disorder-related inflammatory skin disease. Recent studies have suggested a contribution of T cell activation in the pathogenesis of psoriasis. Interleukin-2 (IL-2)-inducible T cell kinase (ITK) regulates T cell activation, including proliferation, and cytokine production. In this study, we investigated the effect of the topically administered selective ITK inhibitor BMS-509744 on imiquimod (IMQ)-induced psoriasis-like skin inflammation in mice. Topically administered BMS-509744 ameliorated IMQ-induced psoriasis-like skin inflammation as shown by decreased skin lesions, epidermal thickening, and cell infiltration into the dermis. These suppressive effects occurred with lower numbers of cluster of differentiation antigen-3+ (CD3+) T cells and T helper subset 17 (Th17)-related cytokine expression in IMQ-treated skin. IMQ-induced upregulation of proinflammatory cytokine expression was also inhibited by topical application of BMS-509744 in IMQ-treated skin. Our report showed for the first time that topical application of BMS-509744 ameliorated psoriasis-like skin inflammation in mice, which is likely mediated by the inhibition of T cell activation in the skin lesions.

Prolonged photo-carriers generated in a massive-and-anisotropic Dirac material.

Transient electron-hole pairs generated in semiconductors can exhibit unconventional excitonic condensation. Anisotropy in the carrier mass is considered as the key to elongate the life time of the pairs, and hence to stabilize the condensation. Here we employ time- and angle-resolved photoemission spectroscopy to explore the dynamics of photo-generated carriers in black phosphorus. The electronic structure above the Fermi level has been successfully observed, and a massive-and-anisotropic Dirac-type dispersions are confirmed; more importantly, we directly observe that the photo-carriers generated across the direct band gap have the life time exceeding 400 ps. Our finding confirms that black phosphorus is a suitable platform for excitonic condensations, and also open an avenue for future applications in broadband mid-infrared BP-based optoelectronic devices.

Direct evidence of hidden local spin polarization in a centrosymmetric superconductor LaO0.55 F0.45BiS2.

Conventional Rashba spin polarization is caused by the combination of strong spin-orbit interaction and spatial inversion asymmetry. However, Rashba-Dresselhaus-type spin-split states are predicted in the centrosymmetric LaOBiS2 system by recent theory, which stem from the local inversion asymmetry of active BiS2 layer. By performing high-resolution spin- and angle-resolved photoemission spectroscopy, we have investigated the electronic band structure and spin texture of superconductor LaO0.55F0.45BiS2. Here we present direct spectroscopic evidence for the local spin polarization of both the valence band and the conduction band. In particular, the coexistence of Rashba-like and Dresselhaus-like spin textures has been observed in the conduction band. The finding is of key importance for fabrication of proposed dual-gated spin-field effect transistor. Moreover, the spin-split band leads to a spin-momentum locking Fermi surface from which superconductivity emerges. Our demonstration not only expands the scope of spintronic materials but also enhances the understanding of spin-orbit interaction-related superconductivity.

Rab3 interacting molecule 3 mutations associated with autism alter regulation of voltage-dependent Ca²âº channels.

Autism is a neurodevelopmental psychiatric disorder characterized by impaired reciprocal social interaction, disrupted communication, and restricted and stereotyped patterns of interests. Autism is known to have a strong genetic component. Although mutations in several genes account for only a small proportion of individuals with autism, they provide insight into potential biological mechanisms that underlie autism, such as dysfunction in Ca(2+) signaling, synaptic dysfunction, and abnormal brain connectivity. In autism patients, two mutations have been reported in the Rab3 interacting molecule 3 (RIM3) gene. We have previously demonstrated that RIM3 physically and functionally interacts with voltage-dependent Ca(2+) channels (VDCCs) expressed in neurons via the ß subunits, and increases neurotransmitter release. Here, by introducing corresponding autism-associated mutations that replace glutamic acid residue 176 with alanine (E176A) and methionine residue 259 with valine (M259V) into the C2B domain of mouse RIM3, we demonstrate that both mutations partly cancel the suppressive RIM3 effect on voltage-dependent inactivation of Ba(2+) currents through P/Q-type CaV2.1 recombinantly expressed in HEK293 cells. In recombinant N-type CaV2.2 VDCCs, the attenuation of the suppressive RIM3 effect on voltage-dependent inactivation is conserved for M259V but not E176A. Slowing of activation speed of P/Q-type CaV2.1 currents by RIM3 is abolished in E176A, while the physical interaction between RIM3 and ß subunits is significantly attenuated in M259V. Moreover, increases by RIM3 in depolarization-induced Ca(2+) influx and acetylcholine release are significantly attenuated by E176A in rat pheochromocytoma PC12 cells. Thus, our data raise the interesting possibility that autism phenotypes are elicited by synaptic dysfunction via altered regulation of presynaptic VDCC function and neurotransmitter release.

TRPV4 channel activity is modulated by direct interaction of the ankyrin domain to PI(4,5)P2.

Mutations in the ankyrin repeat domain (ARD) of TRPV4 are responsible for several channelopathies, including Charcot-Marie-Tooth disease type 2C and congenital distal and scapuloperoneal spinal muscular atrophy. However, the molecular pathogenesis mediated by these mutations remains elusive, mainly due to limited understanding of the TRPV4 ARD function. Here we show that phosphoinositide binding to the TRPV4 ARD leads to suppression of the channel activity. Among the phosphoinositides, phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) most potently binds to the TRPV4 ARD. The crystal structure of the TRPV4 ARD in complex with inositol-1,4,5-trisphosphate, the head-group of PI(4,5)P2, and the molecular-dynamics simulations revealed the PI(4,5)P2-binding amino-acid residues. The TRPV4 channel activities were increased by titration or hydrolysis of membrane PI(4,5)P2. Notably, disease-associated TRPV4 mutations that cause a gain-of-function phenotype abolished PI(4,5)P2 binding and PI(4,5)P2 sensitivity. These findings identify TRPV4 ARD as a lipid-binding domain in which interactions with PI(4,5)P2 normalize the channel activity in TRPV4.

Perpendicular magnetic anisotropy with enhanced orbital moments of Fe adatoms on a topological surface of Bi2Se3.

We have found a perpendicular magnetic anisotropy of iron adatoms on a surface of the prototypical three-dimensional topological insulator Bi2Se3 by using x-ray magnetic circular dichroism measurements. The orbital magnetic moment of Fe is strongly enhanced at lower coverage, where angle-resolved photoemission spectroscopy shows coexistence of non-trivial topological states at the surface.

Involvement of the endogenous cannabinoid 2 ligand 2-arachidonyl glycerol in allergic inflammation.

BACKGROUND: Cannabinoid (CB) 2 is expressed on immune and inflammatory cells. Identification of 2-arachidonyl glycerol (2-AG) and anandamide as endogenous CB2 ligands has allowed investigations of the roles of CB2 and its endogenous ligand system in inflammatory cells. However, the roles of this receptor-ligand system in inflammatory and allergic immune responses in vivo have not been fully elucidated. METHODS: Two mouse allergy models, namely ear dermatitis induced by 2,4-dinitrofluorobenzene and allergic bronchitis induced by ovalbumin, were analyzed for 2-AG amounts in allergic tissues, with reference to allergic and inflammatory symptoms. To investigate the gene expression via CB2 in inflammatory cells, human promyelocytic HL-60 cells were stimulated by the CB2 ligand 2-AG ether and analyzed using a DNA microarray. RESULTS: In the ear dermatitis model, the 2-AG amount increased upon serial 2,4-dinitrofluorobenzene challenges and was correlated with ear weight gain. The increased ear thickness in this allergy model was clearly suppressed in CB2 knockout mice, suggesting that the generated endogenous CB2 ligands induce ear thickness through aberrant inflammatory responses and remodeling mediated via CB2. In the allergic bronchitis model, the 2-AG level in bronchoalveolar lavage was increased and sustained during the elevation of inflammatory cell infiltration. The DNA microarray analysis of human HL-60 cells revealed that 2-AG ether induced expressions of not only inflammatory chemokines/cytokines but also of cell growth factors. CONCLUSION: Our data strongly suggest that endogenous CB2 ligands upregulated upon disease progression in allergic models are involved in aberrant alterations of both inflammatory responses and tissue cell growth.

The cannabinoid receptor-2 is involved in allergic inflammation.

AIM: To investigate the role of cannabinoid receptor-2 (CB2) in allergic inflammation in CB2 knockout (CB2-KO) mice. MAIN METHODS: The swelling reaction of the pinna to various stimuli was compared between CB2-KO and wild-type (WT) mice in terms of edema and acanthosis. KEY FINDINGS: Ear swelling induced by repeated application of 2,4-dinitrofluorobenzene in CB2-KO mice was significantly decreased compared with that in WT mice. In an ovalbumin model, pinna edema was significantly suppressed in CB2-KO mice in comparison with that in WT mice. The contribution of CB2 to edema was investigated in a more extreme dermatitis model using oxazolone. Delayed-type hypersensitivity reactions in this model were also suppressed in CB2-KO mice. In each of these three different allergic dermatitis models, there was a significant decrease in edema and acanthosis in CB2-KO mice compared with WT mice. SIGNIFICANCE: These results clearly demonstrate that CB2 and its endogenous ligands participate not only in the acute, edematous phase of allergic dermatitis, but also in the chronic irreversible acanthosis reaction.

Involvement of cannabinoid CB2 receptors in the IgE-mediated triphasic cutaneous reaction in mice.

Involvement of cannabinoid CB2 receptors in the IgE-mediated cutaneous reaction was investigated. Epicutaneous challenge with 2,4-dinitrofluorobenzene caused a triphasic swelling in the ear of BALB/c and C57BL/6 mice passively sensitized with anti-dinitrophenol IgE. Peak responses of the ear swelling appeared at 1 h, 24 h, and 8 days after the challenge in both strains of mice. In contrast, cannabinoid CB2 receptor-deficient mice failed to exhibit the obvious triphasic ear swelling observed in wild-type mice. Oral administration of cannabinoid CB2 receptor antagonist/inverse agonists [N-(benzo[1,3]dioxol-5-ylmethyl)-7-methoxy-2-oxo-8-pentyloxy-1,2-dihydroquinoline-3-carboxamide] (JTE-907) and {N-[(1S)-endo-1,3,3-trimethylbicyclo[2,2,1]heptan-2yl]5-(4-chloro-3-methyl-phenyl)-1-(4-methylbenzyl)pyrazole-3-carboxamide} (SR144528) at doses of 0.1-10 mg/kg significantly and dose-dependently suppressed all three phases of ear swelling in BALB/c mice. Interestingly, epicutaneous treatment with an ether-linked analogue of endogenous cannabinoids, 2-arachidonoylglycerol, caused an ear swelling that could be detected at 1 h, 24 h, and 8 days after treatment of both BALB/c and C57BL/6 mice. These results suggest that cannabinoid CB2 receptors are involved in induction of the triphasic cutaneous reaction mediated by IgE, and that cannabinoid CB2 receptor antagonist/inverse agonists may serve as anti-allergic agents in the treatment of allergic dermatitis.

Involvement of cannabinoid CB(2) receptor-mediated response and efficacy of cannabinoid CB(2) receptor inverse agonist, JTE-907, in cutaneous inflammation in mice.

Involvement of cannabinoid CB(2) receptor and effect of cannabinoid CB(2) receptor antagonist/inverse agonists on cutaneous inflammation were investigated. Mice ears topically exposed to an ether-linked analogue of 2-arachidonoylglycerol (2-AG-E) or selective cannabinoid CB(2) receptor agonist, {4-[4-(1,1-dimethylheptyl)-2,6-dimethoxy-phenyl]-6.6-dimethyl-bicyclo[3.1.1]hept-2-en-2-yl}-methanol (HU-308), had early and late ear swelling (0--24 h and 1--8 days after exposure, respectively). Both types of responses induced by 2-AG-E were significantly suppressed by oral administration of cannabinoid CB(2) receptor antagonist/inverse agonists, [N-(benzo[1,3]dioxol-5-ylmethyl)-7-methoxy-2-oxo-8-pentyloxy-1,2-dihydroquinoline-3-carboxamide] (JTE-907) and {N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2 yl]5-(4-chloro-3-methyl-phenyl)-1-(4-methylbenzyl)pyrazole-3-carboxamide}} (SR 144528). In contrast, JTE-907 did not affect arachidonic acid-induced swelling. Orally administered JTE-907 (0.1-10 mg/kg) and SR 144528 (1 mg/kg) also produced significant inhibition of dinitrofluorobenzene-induced ear swelling, with increased cannabinoid CB(2) receptor mRNA expression observed in the inflamed ear. These results suggest that cannabinoid CB(2) receptor is partially involved in local inflammatory responses and cannabinoid CB(2) receptor antagonist/inverse agonist has beneficial effects on ear swelling.

Glioma cells under hypoxic conditions block the brain microvascular endothelial cell death induced by serum starvation.

Angiogenesis is one of essential components for the growth of neoplasms, including malignant gliomas. However, tumor vascularization is often poorly organized and marginally functional due to tumor structural abnormalities, inducing regional or temporal hypoxic conditions and nutritional shortages in tumor tissues. We investigated how during angiogenesis migrating endothelial cells survive in these hypoxic and reduced nutritional conditions. Human brain microvascular endothelial cells (HBMECs) underwent apoptosis and necrosis after serum withdrawal. This endothelial cell death was blocked by recombinant VEGF protein or the culture medium of U251 glioma cells exposed to hypoxia (H-CM). Hypoxic treatment increased vascular endothelial growth factor (VEGF) and tumor necrosis factor alpha (TNF-alpha) expression in U251 glioma cells. H-CM activated nuclear factor-kappaB (NFkappaB) protein and increased the gene expression of antiapoptotic factors including Bcl-2, Bcl-X(L), survivin and X-chromosome-linked inhibitor of apoptosis protein (XIAP) in endothelial cells. The survival activity of H-CM for endothelial cells was abolished by two kinds of VEGF inhibitors {Cyclopeptidic VEGF inhibitor and a VEGF receptor tyrosine kinase inhibitor (4-[(4'-chloro-2'-fluoro) phenylamino]-6, 7-dimethoxyquinazoline)} or NFkappaB inhibitors (ALLN and BAY 11-7082). These VEGF inhibitors did not block the activation of NFkappaB induced by H-CM in endothelial cells. On the contrary, TNF-alpha antagonist WP9QY enhanced the survival activity of H-CM for endothelial cells and blocked NFkappaB activation induced by H-CM under serum-starved conditions. Taken together, our data suggest that both the secretion of VEGF from glioma cells and activation of NFkappaB in endothelial cells induced by TNF-alpha are necessary for endothelial cell survival as they increase the expression of antiapoptotic genes in endothelial cells under conditions of serum starvation. These pathways may be one of the mechanisms by which angiogenesis is maintained in glioma tissues.

Effects of prednisolone on the cutaneous reaction and skin barrier function in mice treated with a hapten.

Glucocorticoids are effective drugs for the treatment of allergic skin diseases. In the present study, we observed the effects of prednisolone on the cutaneous reaction and skin barrier function in mice treated with a hapten, 2,4-dinitrofluorobenzene. Repeated hapten application onto the mouse ear resulted in a potent ear swelling with an elevation of specific serum IgE. The ear swelling appeared following the second application of the hapten and peaked at 24 h after each application. Specific serum IgE was detected first after the fourth hapten application. Topical treatment with prednisolone apparently suppressed the swelling, whereas it failed to affect the serum specific IgE level. The hapten application caused an increase in transepidermal water loss, which was potently inhibited by prednisolone, although the water content was not affected. Amounts of triglyceride and cholesterol in the ear skin increased after repeated hapten applications, whereas the relative amount of free fatty acid and ceramide diminished. Prednisolone exhibited an inhibitory effect on the changes in lipid content. Thus prednisolone apparently inhibits the alteration of skin barrier function caused by hapten application as well as the cutaneous reaction.