40 research outputs found
IconShop: Text-Guided Vector Icon Synthesis with Autoregressive Transformers
Scalable Vector Graphics (SVG) is a popular vector image format that offers
good support for interactivity and animation. Despite its appealing
characteristics, creating custom SVG content can be challenging for users due
to the steep learning curve required to understand SVG grammars or get familiar
with professional editing software. Recent advancements in text-to-image
generation have inspired researchers to explore vector graphics synthesis using
either image-based methods (i.e., text -> raster image -> vector graphics)
combining text-to-image generation models with image vectorization, or
language-based methods (i.e., text -> vector graphics script) through
pretrained large language models. However, these methods still suffer from
limitations in terms of generation quality, diversity, and flexibility. In this
paper, we introduce IconShop, a text-guided vector icon synthesis method using
autoregressive transformers. The key to success of our approach is to
sequentialize and tokenize SVG paths (and textual descriptions as guidance)
into a uniquely decodable token sequence. With that, we are able to fully
exploit the sequence learning power of autoregressive transformers, while
enabling both unconditional and text-conditioned icon synthesis. Through
standard training to predict the next token on a large-scale vector icon
dataset accompanied by textural descriptions, the proposed IconShop
consistently exhibits better icon synthesis capability than existing
image-based and language-based methods both quantitatively and qualitatively.
Meanwhile, we observe a dramatic improvement in generation diversity, which is
validated by the objective Uniqueness and Novelty measures. More importantly,
we demonstrate the flexibility of IconShop with multiple novel icon synthesis
tasks, including icon editing, icon interpolation, icon semantic combination,
and icon design auto-suggestion.Comment: Project Page: https://icon-shop.github.io
Molecular basis of ligand recognition and activation of human V2 vasopressin receptor.
Vasopressin type 2 receptor (V2R) belongs to the vasopressin (VP)/oxytocin (OT) receptor subfamily of G protein-coupled receptors (GPCRs), which comprises at least four closely related receptor subtypes: V1aR, V1bR, V2R, and OTR. These receptors are activated by arginine vasopressin (AVP) and OT, two endogenous nine-amino acid neurohypophysial hormones, which are thought to mediate a biologically conserved role in social behavior and sexual reproduction. V2R is mainly expressed in the renal collecting duct principal cells and mediates the antidiuretic action of AVP by accelerating water reabsorption, thereby playing a vital role in controlling water homeostasis. Moreover, numerous gain-of-function and loss-of-function mutations of V2R have been identified and are closely associated with human diseases, including nephrogenic syndrome of inappropriate diuresis (NSIAD) and X-linked congenital nephrogenic diabetes insipidus (NDI). Thus, V2R has attracted intense interest as a drug target. However, due to a lack of structural information, how AVP recognizes and activates V2R remains elusive, which hampers the V2R-targeted drug design. Here, we determined a 2.6 Å resolution cryo-EM structure of the full-length, G s -coupled human V2R bound to AVP (Fig. 1a; Supplementary information, Table S1). The G s protein was engineered based on mini-G s that was used in the crystal structure determination of the G s -coupled adenosine A 2A receptor (A 2A R) to stabilize the V2R–G s protein complex (Supplementary information, Data S1). The final structure of the AVP–V2R–G s complex contains all residues of AVP (residues 1–9), the Gα s Ras-like domain, Gβγ subunits, Nb35, scFv16, and the V2R residues from T31 to L339 8.57 (superscripts refer to Ballesteros–Weinstein numbering). The majority of amino acid side chains, including AVP, transmembrane domain (TMD), all flexible intracellular loops (ICLs) and extracellular loops (ECLs) except for ICL3 and G185–G188 in ECL2, were well resolved in the model, refined against the EM density map (Fig. 1a; Supplementary information, Figs. S1–3). The complex structure can provide detailed information on the binding interface between AVP and helix bundle of the receptor, as well as the receptor–G s interface
Protective effect and mechanism of Lactobacillus on cerebral ischemia reperfusion injury in rats
The present study was designed to investigate the protective effects and mechanism of inactivated lactobacillus (ILA) on cerebral ischemia reperfusion injury (CIRI) in rats. In this experiment, 30 male Sprague Dawley rats were randomly divided into control group, IRI groups, and ILA group. A middle cerebral artery occlusion and reperfusion model was prepared. The rats were killed after 24 hours of recovery of blood flow of cerebral ischemia resulting from 60-min occlusion. The cerebral infarction volume and neurological scores were assayed by staining and behavioral observation. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were assayed by biochemical kits. Cell apoptosis was assayed by Tunnel and the Toll-like receptor (TLR)-4, IkB, and A20 were assayed by western blot. The neurobehavioral scores in IRI rats were significantly lower compared to the control group while ILA improved the neurobehavioral scores of the ILA groups. The cerebral infarction volume and neural cell apoptosis of rats in the ILA groups decreased significantly compared with those in the IRI group. In addition, MDA level in the ILA groups decreased whereas SOD activity increased compared to the IRI group. Moreover, ILA also inhibited the expression of TLR-4 and promoted the expression of IkB and A20. ILA inhibited the apoptosis of neural cells, decreased cerebral infarction volume, and reduced oxidative stress through inhibition of TLR-4/NF-kappa B signaling, improving neurobehavioral scores. Thus from the present study it was concluded that ILA has protective effect on CIRI
Exploring the Taste Characteristics and ACE-inhibitory Active Mechanism of Stropharia rugosoannulata Decapeptides Based on Virtual Screening, Molecular Docking, and Molecular Interactions
To explore the taste characteristics and potential biological activities of the decapeptides of Stropharia rugosoannulata, two decapeptides (RIEDNLVIIR and SLPIKPRVPF) were selected to predict and validate the taste-presenting properties and ACE inhibitory activity mechanism by using virtual screening, molecular docking, and molecular interactions techniques. The results showed that the two decapeptides of S. rugosoannulata all had salty and umami tastes and ACE-inhibited peptide fragments. RIEDNLVIR had a salty taste, and SLPIKPRVPF had an umami taste. Two decapeptides of S. rugosoannulata could strongly bind to ACE receptors to form hydrogen bonds and electrostatic interactions. The in vitro activity validation results showed that the salty decapeptide RIEDNLVIIR inhibited the ACE well with an IC50 value of 0.012 mg/mL. The molecular interaction thermodynamics and kinetics results showed that the binding between RIEDNLVIR and ACE receptor was the specific binding of enthalpy-driven reaction. The results of virtual screening activity prediction, in vitro activity validation, and molecular docking and molecular interactions for ACE inhibition mechanism analysis were consistent. The study provides a theoretical basis for understanding the taste characteristics and ACE inhibition mechanism of S. rugosoannulata decapeptides and lays a foundation for applying the decapeptides with ACE inhibitory activity in healthy condiments and functional products
RAGE binds C1q and enhances C1q-mediated phagocytosis
â–ş RAGE is a newly identified, native C1q globular domain receptor. â–ş A receptor complex of RAGE and Mac-1 could be formed with enhanced affinity for C1q. â–ş C1q-induced cell adhesion and phagocytosis was inhibited by RAGE or Mac-1 antibodies. â–ş RAGE is linked to leukocyte recruitment and phagocytosis of C1q-coated material.
RAGE, the multiligand receptor of the immunoglobulin superfamily of cell surface molecules, is implicated in innate and adaptive immunity. Complement component C1q serves roles in complement activation and antibody-independent opsonization. Using soluble forms of RAGE (sRAGE) and RAGE-expressing cells, we determined that RAGE is a native C1q globular domain receptor. Direct C1q–sRAGE interaction was demonstrated with surface plasmon resonance (SPR), with minimum Kd 5.6μM, and stronger binding affinity seen in ELISA-like experiments involving multivalent binding. Pull-down experiments suggested formation of a receptor complex of RAGE and Mac-1 to further enhance affinity for C1q. C1q induced U937 cell adhesion and phagocytosis was inhibited by antibodies to RAGE or Mac-1. These data link C1q and RAGE to the recruitment of leukocytes and phagocytosis of C1q-coated material
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RAGE ligand upregulation of VEGF secretion in ARPE-19 cells
The importance of VEGF in stimulating neovascular age-related macular degeneration (AMD) is well-recognized, but the initiating factors that induce local upregulation of VEGF remain unclear. The current study was conducted to test the hypothesis that activation of RAGE (receptor for advanced glycation end products [AGEs]) by its ligands, including AGEs, amyloid-beta peptide (Abeta), and S100B/calgranulins, some of which are known components of drusen and Bruch's membrane deposits, modulate secretion of VEGF by retinal pigment epithelial (RPE) cells.
ARPE-19 cells were used for all experiments. The cells were transfected with constructs encoding a signal transduction mutant of human RAGE to assess the RAGE-dependence of intracellular signaling. VEGF secretion and gene expression were assessed by ELISA and quantitative real-time PCR. SDS-PAGE and size exclusion chromatography were performed to analyze the structural changes of S100B after oxidation of its thiol groups under denaturing and nondenaturing conditions, respectively. NF-kappaB activation was assessed via electrophoretic mobility shift assay (EMSA). The impact of the NF-kappaB inhibition was assessed by using parthenolide.
ARPE-19 cells basally secreted VEGF under normal cell culture conditions. Immobilized ligands of RAGE increased VEGF secretion in a RAGE-dependent manner. In contrast, soluble AGE-BSA, fresh Abeta, and S100B were less effective in increasing VEGF secretion. Studies with Abeta demonstrated that oligomeric and surface-immobilized forms of Abeta, but not soluble monomeric forms of Abeta, were effective upregulators of VEGF secretion via RAGE. Oxidation of S100B's thiol groups resulted in the formation of oligomers that displayed distinct RAGE biological activity compared with the simple dimeric form. RAGE-mediated upregulation of VEGF secretion by ARPE-19 cells was largely dependent on NF-kappaB, as indicated by studies with parthenolide.
Immobilized or oligomerized ligands for RAGE induce RPE cells to increase VEGF secretion. NF-kappaB plays a central role in RAGE-dependent RPE secretion of VEGF. In AMD, activation of the RAGE axis in RPE cells may contribute to upregulation of VEGF, potentially inciting or propagating neovascular macular disease