ABSTRACT
Genetic association studies have demonstrated the critical involvement of the microglial immune response in Alzheimer's disease (AD) pathogenesis. Phospholipase C-gamma-2 (PLCG2) is selectively expressed by microglia and functions in many immune receptor signaling pathways. In AD, PLCG2 is induced uniquely in plaque-associated microglia. A genetic variant of PLCG2, PLCG2P522R, is a mild hypermorph that attenuates AD risk. Here, we identified a loss-of-function PLCG2 variant, PLCG2M28L, that confers an increased AD risk. PLCG2P522R attenuated disease in an amyloidogenic murine AD model, whereas PLCG2M28L exacerbated the plaque burden associated with altered phagocytosis and Aß clearance. The variants bidirectionally modulated disease pathology by inducing distinct transcriptional programs that identified microglial subpopulations associated with protective or detrimental phenotypes. These findings identify PLCG2M28L as a potential AD risk variant and demonstrate that PLCG2 variants can differentially orchestrate microglial responses in AD pathogenesis that can be therapeutically targeted.
Subject(s)
Alzheimer Disease , Animals , Mice , Alzheimer Disease/genetics , Genetic Association Studies , Microglia , Phagocytosis/genetics , Phenotype , Plaque, Amyloid , Phospholipase C gamma/metabolismABSTRACT
Ultraviolet organic light-emitting diodes (UV OLEDs) have attracted increasing attention because of their promising applications in healthcare, industry, and agriculture; however, their development has been hindered by the shortage of robust UV emitters. Herein, we embedded double boron-oxygen units into nonlinear polycyclic aromatic hydrocarbons (BO-PAHs) to regulate their molecular configurations and excited-state properties, enabling novel bent BO-biphenyl (BO-bPh) and helical BO-naphthyl (BO-Nap) emitters with hybridized local and charge-transfer (HLCT) characteristics. They could be facilely synthesized in gram-scale amounts via a highly efficient two-step route. BO-bPh and BO-Nap showed strong UV and violet-blue photoluminescence in toluene with full width at half-maximum values of 25 and 37 nm, along with quantum efficiencies of 98 and 99%, respectively. A BO-bPh-based OLED showed high color purity UV electroluminescence peaking at 394 nm with Commission Internationale de l'Eclairage (CIE) coordinates of (0.166, 0.021). Moreover, the device demonstrated a record-high maximum external quantum efficiency (EQE) of 11.3%, achieved by successful hot exciton utilization. This work demonstrates the promising potential of double BO-PAHs as robust emitters for future UV OLEDs.
ABSTRACT
X-ray detection, which plays an important role in medical and industrial fields, usually relies on inorganic scintillators to convert X-rays to visible photons; although several high-quantum-yield fluorescent molecules have been tested as scintillators, they are generally less efficient. High-energy radiation can ionize molecules and create secondary electrons and ions. As a result, a high fraction of triplet states is generated, which act as scintillation loss channels. Here we found that X-ray-induced triplet excitons can be exploited for emission through very rapid, thermally activated up-conversion. We report scintillators based on three thermally activated delayed fluorescence molecules with different emission bands, which showed significantly higher efficiency than conventional anthracene-based scintillators. X-ray imaging with 16.6 line pairs mm-1 resolution was also demonstrated. These results highlight the importance of efficient and prompt harvesting of triplet excitons for efficient X-ray scintillation and radiation detection.
Subject(s)
Electrons , Photons , Fluorescence , X-RaysABSTRACT
The thermal stability of α-diimine nickel catalysts has always been the focus of research. The introduction of large groups in the backbone or N-aryl ortho-position is a relatively mature solution. However, the question of whether the N-aryl bond rotation is a factor affecting the thermal stability of nickel catalysts is still open. In this work, the effects of N-aryl para-benzhydryl substitutes on catalyst thermal stability are investigated, and the results of ethylene polymerization and the factors affecting thermal stability (steric effect, electronic effect, five-membered coordination ring stability, N-aryl bond rotation, etc.) are systematically analyzed. It is believed that the introduction of large steric hindrance groups at the N-aryl para-position hinders the rotation of the N-aryl bond. This obstacle effect is beneficial to improving catalyst thermal stability, and the obstacle capacity is weakened with the increase of ortho-substituent size.
Subject(s)
Nickel , Nickel/chemistry , PolymerizationABSTRACT
Bone fractures are common impact injuries typically resolved through natural processes of osteogenic regeneration and bone remodeling, restoring the biological and mechanical function. However, dysfunctionality in bone healing and repair often arises in the context of aging-related chronic disorders, such as Alzheimer's disease (AD). There is unmet need for effective pharmacological modulators of osteogenic differentiation and an opportunity to probe the complex links between bone biology and cognitive disorders. We previously discovered the small molecule DIPQUO, which promotes osteoblast differentiation and bone mineralization in mouse and human cell culture models, and in zebrafish developmental and regenerative models. Here, we examined the detailed function of this molecule. First, we used kinase profiling, cellular thermal shift assays, and functional studies to identify glycogen synthase kinase 3-beta (GSK3-ß) inhibition as a mechanism of DIPQUO action. Treatment of mouse C2C12 myoblasts with DIPQUO promoted alkaline phosphatase expression and activity, which could be enhanced synergistically by treatment with other GSK3-ß inhibitors. Suppression of the expression or function of GSK3-ß attenuated DIPQUO-dependent osteogenic differentiation. In addition, DIPQUO synergized with GSK3-ß inhibitors to stimulate expression of osteoblast genes in human multipotent progenitors. Accordingly, DIPQUO promoted accumulation and activation of ß-catenin. Moreover, DIPQUO suppressed activation of tau microtubule-associated protein, an AD-related effector of GSK3-ß signaling. Therefore, DIPQUO has potential as both a lead candidate for bone therapeutic development and a pharmacological modulator of GSK3-ß signaling in cell culture and animal models of disorders including AD.
Subject(s)
Cell Differentiation/drug effects , Glycogen Synthase Kinase 3 beta/metabolism , Osteogenesis/drug effects , Signal Transduction/drug effects , Animals , Cell Line , Dose-Response Relationship, Drug , Humans , Mice , Myoblasts/cytology , Myoblasts/drug effectsABSTRACT
Capillary electrophoresis with fluorescence detection (CE-F) is a powerful method to measure enzyme activation in single cells. However, cellular enzymatic assays used in CE-F routinely utilize reporter substrates that possess a bulky fluorophore that may impact enzyme kinetics. To address these challenges, we describe a "fix and click" method utilizing an alkyne-terminated enzyme activation reporter, aldehyde-based fixation, and a click chemistry reaction to attach a fluorophore prior to analysis by single-cell CE-F. The "fix and click" strategy was utilized to investigate sphingolipid signaling in both immortalized cell lines and primary human colonic epithelial cells. When the sphingosine alkyne reporter was loaded into cells, this reporter was metabolized to ceramide (31.6 ± 3.3% peak area) without the production of sphingosine-1-phosphate. In contrast, when the reporter sphingosine fluorescein was introduced into cells, sphingosine fluorescein was converted to sphingosine-1-phosphate and downstream products (32.8 ± 5.7% peak area) without the formation of ceramide. Sphingolipid metabolism was measured in single cells from both differentiated and stem/proliferative human colonic epithelium using "fix and click" paired with CE-F to highlight the diversity of sphingosine metabolism in single cells from primary human colonic epithelium. This novel method will find widespread utility for the performance of single-cell enzyme assays by virtue of its ability to temporally and spatially separate cellular reactions with alkyne-terminated reporters, followed by the assay of enzyme activation at a later time and place.
Subject(s)
Lysophospholipids , Sphingolipids , Biological Assay , Ceramides/metabolism , Click Chemistry , Epithelial Cells/metabolism , Humans , Sphingolipids/metabolism , SphingosineABSTRACT
BACKGROUND: Needle knife papillotomy (NKP) and fistulotomy (NKF) are the two most commonly used rescue techniques for patients with difficult biliary cannulation (DBC). Anatomy of the major duodenal papillae (MDP) influences the optimal precut technique for biliary access. However, comparative studies of the success and safety of NKP and NKF based on the anatomy of MDP have been scarce. METHODS: Patients with intact MDPs for therapeutic endoscopic retrograde cholangio-pancreatography (ERCP) in our center were enrolled. Early needle knife precuts were uniformly applied to patients with DBC. Difficult MDPs were classified into one of five types based on their endoscopic anatomy. Each type of MDP was allocated to NKP or NKF treatment. Patients with types 1 and 2 papillae always received NKF, 3 and 4 received NKP, and 5 could receive either. The safety and efficacy were analyzed between NKP and NKF, and among different types of MDPs. RESULTS: A total of 188 out of 1674 patients undergoing ERCP satisfied the criteria for early precutting: 75 patients were assigned to the NKP group and 113 to the NKF group. The total initial success rate of biliary cannulation (ISRBC) of the precut techniques (both NKP and NKF) for patients with DBC was 91.5%. The ISRBC of patients of the NKP group was similar to that of the NKF group (90.7% vs 92.0%, P > 0.05). The ISRBC of the patients in the swollen MDP subgroup (96.1%) was higher than that of patients in the distorted MDP subgroup (81.8%, P = 0.030). The total and specific complications of the patients of the NKP group were similar to those of the NKF group (P > 0.05). CONCLUSIONS: NKP and NKF, as selected on the basis of MDP anatomy, are equally safe and highly efficient for patients with DBC to allow biliary cannulation. Patients with swollen MDPs had a higher ISRBC than patients with distorted MDPs. Selecting a precut method based on MDP anatomy is an effective and safe strategy for patients with DBC.
Subject(s)
Cholangiopancreatography, Endoscopic Retrograde , Sphincterotomy, Endoscopic , Catheterization , Cholangiopancreatography, Endoscopic Retrograde/adverse effects , Cholangiopancreatography, Endoscopic Retrograde/methods , Humans , Prospective Studies , Sphincterotomy, Endoscopic/adverse effects , Sphincterotomy, Endoscopic/instrumentation , Treatment OutcomeABSTRACT
Expendable current profiler (XCP) is one of the most vital devices detecting ocean currents. Compared with other methods, the expendable feature makes trials with XCP much faster and more hidden, while the accuracy of XCP is considerably influenced by electromagnetic noise all around. Aiming at researching the influence and reducing the noise, this study carried out laboratory simulation experiments. The designed laboratory experiments mainly have a self-developed rotation gear, an XCP prototype, a plastic flume, and two copper plates as power. Firstly, these experiments analyzed the main sources of electromagnetic noise for XCP detection. Secondly, we built a noise simulation environment and conducted XCP detection experiments under different noise in the flume. The data obtained by XCP were transmitted to the computer to be stored and processed. The results show the internal noise impact on XCP is significantly less than the external. For an excitation power of 1 mV, the offset of theoretical and actual data brought by internal noise is 12 times smaller than external and can be corrected.
ABSTRACT
A series of novel tetradentate Pt(II) and Pd(II) complexes containing fused 6/6/6 or 6/6/5 metallocycles employing azacarbazolylcarbazole (ACzCz)-based ligands was developed. Systematic experimental and theoretical studies suggest that both the ligand structures and the central metal ions have great influences on the electrochemical and photophysical properties of the complexes. The time-dependent density functional theory (TD-DFT) calculations and natural transition orbital (NTO) analyses reveal that the Pt(II) complexes possess 10.8-15.2% metal-to-ligand charge transfer (3MLCT) mixed with ligand-centered (3LC) characters, by contrast, the Pd(II) complexes exhibit significantly decreased 4.2-7.1% 3MLCT characters and enhanced 3LC compositions. All of the Pt(II) and Pd(II) complexes possess various channels for the intersystem crossing (ISC) on the basis of small energy gaps ΔES1-Tn and matching transition orbital compositions; moreover, Pd(ACzCz-1) and Pd(ACzCz-2) also possess efficient reverse intersystem crossing (RISC) to show both delayed fluorescence (DF) and phosphorescence in PMMA films at room temperature (RT). Pt(ACzCz-3) has ΦPL values of 57% with a τ of 5.1 µs in dichloromethane at RT and 50% with 3.9 µs in PMMA at RT. Notably, Pd(ACzCz-1) exhibits ultralong low-temperature phosphorescence with a τ of 1307 µs. Pt(ACzCz-2)-based green OLED employing 26mCPy as the host demonstrated a peak EQE of 8.2% and a Lmax of 24065 cd/m2.
ABSTRACT
BACKGROUND: Missed and incompletely resected lesions remain the main cause of the recurrence of advanced neoplasms (ANs) in post-polypectomy patients. This study aims to determine whether the recurrence of ANs can be predicted and reduced by the newly developed clear colonoscopy procedure. METHODS: Between 2006 and 2010, a total of 1350 participants with colorectal neoplasm were equally randomized to clear colonoscopy surveillance (CCS) and routine colonoscopy surveillance (RCS) in our center. Clear colonoscopy was achieved through repeat colonoscopy. On surveillance colonoscopy at 3 (for high-risk patients) and 5 (for low-risk patients) years, the recurrence of ANs and the relationship between the frequency of repeat examinations required for a clear colonoscopy and the recurrence of ANs were analyzed. RESULTS: Surveillance colonoscopy at 3 and 5 years showed that the incidence of ANs in patients belonging to the CCS group was 1.7%, which was lower than 4.7% in patients belonging to the RCS group (P = 0.012) for both high- and low-risk patients. Out of the 1126 patients who achieved clear colonoscopy on first repeat examination, only 5 ( 0.4%) were found to have ANs on surveillance examination, whereas 12 out of the 217 (5.4%) patients on second repeat examination and 5 out of the 29 (17.2%) patients on third repeat examination were found to have ANs (P < 0.001). CONCLUSION: Surveillance based on clear colonoscopy decreased the incidence of ANs in post-polypectomy patients. The number of repeat examinations required for a clear colonoscopy is an important factor in the prediction of the recurrence of ANs.
Subject(s)
Colonic Polyps , Colorectal Neoplasms , Colonoscopy , Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/surgery , Humans , Incidence , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/epidemiologyABSTRACT
In this work, the antibiotic resistance of 218 isolates to 9 different antibiotics was analyzed with minimum inhibitory concentration method. All Lactobacillus pentosus strains were found to be resistant to streptomycin sulfate and ciprofloxacin hydrochloride. Lactococcus lactis strains were resistant to streptomycin sulfate. Specifically, 90% Klebsiella oxytoca and all Citrobacter freundii strains were resistant to ampicillin sodium. 30% K. oxytoca strains were resistant to ciprofloxacin hydrochloride. All Bacillus albus strains were resistant to erythromycin and 80% strains were resistant to ampicillin sodium. Results from PCR analysis revealed that 90 isolates carried the aadE gene. The tetM gene was detected in four L. pentosus isolates. And the streptomycin resistant gene aadA was detected in one L. pentosus isolate. Metagenome analysis revealed that 74.7% genes associated with antibiotic resistance were antibiotic resistance genes. The tetM and aadA genes, detected in PCR analysis, were also retrieved from the paocai metagenome. In brief, this study generated the antibiotic resistance profile of some paocai-originated bacteria strains. L. pentosus found in the final edible paocai were inherently resistant to antibiotics, such as streptomycin and ciprofloxacin. Results in this work reminds us to carefully choose the LAB strains for traditional Chinese paocai production to avoid potential spreading of antibiotic resistant genes.
Subject(s)
Bacillus , Anti-Bacterial Agents/pharmacology , Bacteria/genetics , China , Drug Resistance, Bacterial , Drug Resistance, Microbial , Microbial Sensitivity TestsABSTRACT
Spreading antimalarial resistance threatens effective treatment of malaria, an infectious disease caused by Plasmodium parasites. We identified a compound, BCH070, that inhibits asexual growth of multiple antimalarial-resistant strains of Plasmodium falciparum (half maximal inhibitory concentration [IC50] = 1-2 µM), suggesting that BCH070 acts via a novel mechanism of action. BCH070 preferentially kills early ring-form trophozoites, and, importantly, equally inhibits ring-stage survival of wild-type and artemisinin-resistant parasites harboring the PfKelch13:C580Y mutation. Metabolomic analysis demonstrates that BCH070 likely targets multiple pathways in the parasite. BCH070 is a promising lead compound for development of new antimalarial combination therapy that retains activity against artemisinin-resistant parasites.
Subject(s)
Antimalarials/pharmacology , Artemisinins/pharmacology , Plasmodium falciparum/drug effects , Antimalarials/administration & dosage , Antimalarials/chemistry , Cells, Cultured , Drug Resistance , Fibroblasts/parasitology , Humans , Molecular Structure , Structure-Activity Relationship , Trypanosoma cruzi/drug effectsABSTRACT
Triphenylphosphine (TPP)-based luminescent compounds are rarely investigated because of the low photoluminescence quantum yield (PLQY). Here, we demonstrate that introducing steric hindrance groups to the TPP moiety and separating the orbitals involved in the transition can drastically suppress the non-radiative decay induced by structural distortion of TPP in the excited state. High PLQY up to 0.89 as well as thermally activated delayed fluorescence are observed from the intramolecular charge-transfer (ICT) molecules with substituted TPP donors (sTPPs) in doped films. The red organic light-emitting diodes employing these emitters achieve comparable external quantum efficiencies to the control device containing a classical phosphorescent dye, revealing the great potential of the ICT emitters based on electrochemically stable sTPPs.
ABSTRACT
The two phospholipase C-γ (PLC-γ) isozymes are major signaling hubs and emerging therapeutic targets for various diseases, yet there are no selective inhibitors for these enzymes. We have developed a high-throughput, liposome-based assay that features XY-69, a fluorogenic, membrane-associated reporter for mammalian PLC isozymes. The assay was validated using a pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC1280) in 384-well format; it is highly reproducible and has the potential to capture both orthosteric and allosteric inhibitors. Selected hit compounds were confirmed with secondary assays, and further profiling led to the interesting discovery that adenosine triphosphate potently inhibits the PLC-γ isozymes through noncompetitive inhibition, raising the intriguing possibility of endogenous, nucleotide-dependent regulation of these phospholipases. These results highlight the merit of the assay platform for large scale screening of chemical libraries to identify allosteric modulators of the PLC-γ isozymes as chemical probes and for drug discovery.
Subject(s)
Cell Membrane/enzymology , Isoenzymes/chemistry , Isoenzymes/metabolism , Phospholipase C gamma/chemistry , Phospholipase C gamma/metabolism , Animals , Humans , Signal Transduction/physiologyABSTRACT
Photostable and bright organic dyes emitting in the near-infrared region are highly desirable for long-term dynamic bioimaging. Herein, we report a synthetic approach to build novel methoxy modified Si-rhodamine (SiRMO) dyes by introducing the methoxybenzene on the xanthene moiety. The brightness of SiRMO increased from 2300 M-1 cm-1 (SiRMO-0) to 49000 M-1 cm-1 (SiRMO-2) when the substituent 2,5-dimethoxybenzene was replaced with 2,6-dimethoxybenzene. Moreover, the stability of SiRMO-2 was significantly improved due to the steric hindrance protection of the two methoxy groups on the ninth carbon atom of the xanthene. After fast cellular uptake, the SiRMO dyes selectively stained the mitochondria with a low background in live cultured cells and primary neurons. The high brightness and stability of SiRMO-2 significantly improved the capability of monitoring mitochondria dynamic processes in living cells under super-resolution conditions. Moreover, with the fluorescence nanoscopy techniques, we observed the structure of mitochondrial cristae and mitochondria fission, fusion, and apoptosis with a high temporal resolution. Under two-photon illumination, SiRMO-2 showed also enhanced two-photon brightness and stability, which are important for imaging in thick tissue.
Subject(s)
Fluorescent Dyes/chemistry , Microscopy, Fluorescence, Multiphoton , Mitochondria/chemistry , Rhodamines/chemistry , Silicon/chemistry , Animals , Cells, Cultured , Chlorocebus aethiops , Fluorescent Dyes/chemical synthesis , HeLa Cells , Humans , Molecular Structure , Optical ImagingABSTRACT
A series of phenylpyridine (ppy)-based 6/5/5 N*C^N^O and biphenyl (bp)-based 6/5/6 N*C^C*N Pt(II) complexes employing tetradentate ligands with nitrogen or oxygen atoms as bridging groups have been developed. Ligand structural modifications have great influences on the electrochemical, photophysical, and excited-state properties, as well as photostabilities of the Pt(II) complexes, which were systematically studied by experimental and theoretical investigations. The time-dependent density functional theory calculations and natural transition orbital analyses reveal that Pt(bp-6), Pt(bp-7), and Pt(bp-8) have dominant ligand-centered (3LC) mixed with small metal-to-ligand charge-transfer (3MLCT) characters in T1 states, resulting in relatively low quantum efficiencies (ΦPL) of 5-33% and 12-32% in dichloromethane solution and PMMA film, respectively. By contrast, Pt(ppy-1) possesses much more 3MLCT character in the T1 state, enabling a high ΦPL of 95% in dichloromethane and 90% in DPEPO film, and large radiative decay rates. The strength of the Pt-N1 coordination bond plays a critical role in the photostability. Pt(ppy-1)- and Pt(bp-6)-doped polystyrene films demonstrate long photostability lifetimes of 150 min for LT97 and LT98.5, respectively. A Pt(ppy-1)-based green OLED using 26mCPy as host realized a peak EQE of 18.5%, which still maintained an EQE of 10.4% at 1000 cd/m2, and an Lmax of over 40â¯000 cd/m2 was achieved. This study should provide a valuable reference for the further development of efficient and stable phosphorescent Pt(II) complexes.
ABSTRACT
Deep-blue-light-emitting materials are urgently desired in high-performance organic light-emitting diodes (OLEDs) for full-color display and solid-state lighting applications. However, the development of stable and efficient deep-blue emitters remains a great challenge. Herein, a series of stable and efficient tetradentate Pd(II)-complex-based deep-blue emitters with rigid 5/6/6 metallocycles and no F atom were designed and synthesized. These deep-blue emitters employ various isoelectronic five-membered heteroaryl-ring-containing ligands to exhibit extremely narrow emission spectra peaking at 439-443 nm with a full width at half-maximum (fwhm) of only 22-38 nm in 2-methyltetrahydrofuran at room temperature. In particular, the design of an intramolecular hydrogen bond enabled the 1-phenyl-1,2,3-trazole-based Pd(II) complexes to achieve CIEy < 0.1 (0.069-0.078; CIE is Commission Internationale de L'Eclairage). Theoretical calculation and natural transition orbital analysis reveal that these deep-blue materials emit light exclusively from their ligand (carbazole)-centered (3LC) states. Moreover, the triplet excited-state property can be efficiently regulated through ligand modification with isoelectronic oxazole and thiazole rings or pyridine rings, resulting in sky-blue-to-yellow materials, which emit light originating from an admixture of metal-to-ligand charge-transfer (3MLCT) and intraligand charge-transfer states. The newly developed Pd(II) complexes are strongly emissive in various matrixes with a quantum efficiency of up to 51% and also highly thermally stable with a 5% weight-reduction temperature (ΔT5%) of up to 400 °C. Deep-blue OLEDs with CIEy < 0.1 employing Pd(II) complexes as emitters were successfully fabricated for the first time. This study demonstrates that the Pd(II) complexes can act as excellent phosphorescent light-emitting materials through rational molecular design and also provide a valuable method for the development of Pd(II)-complex-based efficient and stable deep-blue emitters.
ABSTRACT
This study assessed whether antibiotics could alter gut microbiota to affect host growth and the possibility of alleviation by lactobacilli. We divided four-week-old BABL/c mice into control (Ctrl), antibiotic exposure (Abx), Lactobacillus plantarum PC-170 (PC), and Lactobacillus rhamnosus GG (LGG) group and the Abx, LGG, and PC group received an one-week antibiotic/antibiotic + probiotic treatment. The fecal microbiota and the expression of splenic cytokines were determined. Following the ceftriaxone treatment, the body weight gain of Abx was delayed compared with others. The ceftriaxone treatment significantly decreased the alpha-diversity of the fecal microbiota and altered the fecal microbiota but LGG and PC can partly alleviate the effect. At the end of the study, the microbial community of LGG and PC group were more similar to Ctrl compared with Abx group. The results indicated that ceftriaxone could significantly alter intestinal microbiota. Lactobacilli might alleviate the side effects of antibiotics by stabilizing the intestinal microbiota.
Subject(s)
Anti-Bacterial Agents/pharmacology , Gastrointestinal Microbiome/drug effects , Lactobacillus , Probiotics , Weight Loss/drug effects , Animals , Biodiversity , Body Weight/drug effects , Feces/microbiology , Male , Mice , Mice, Inbred BALB CABSTRACT
Inhibition of TICT can significantly increase the brightness of fluorescent materials. Accurate prediction of TICT is thus critical for the quantitative design of high-performance fluorophores and AIEgens. TICT of 14 types of popular organic fluorophores were modeled with time-dependent density functional theory (TD-DFT). A reliable and generalizable computational approach for modeling TICT formations was established. To demonstrate the prediction power of our approach, we quantitatively designed a boron dipyrromethene (BODIPY)-based AIEgen which exhibits (almost) barrierless TICT rotations in monomers. Subsequent experiments validated our molecular design and showed that the aggregation of this compound turns on bright emissions with ca. 27-fold fluorescence enhancement, as TICT formation is inhibited in molecular aggregates.
ABSTRACT
A diverse group of cell-surface receptors, including many G protein-coupled receptors and receptor tyrosine kinases, activate phospholipase C (PLC) isozymes to hydrolyze phosphatidylinositol 4,5-bisphosphate into the second messengers diacylglycerol and 1,4,5-inositol trisphosphate. Consequently, PLCs control various cellular processes, and their aberrant regulation contributes to many diseases, including cancer, atherosclerosis, and rheumatoid arthritis. Despite the widespread importance of PLCs in human biology and disease, it has been impossible to directly monitor the real-time activation of these enzymes at membranes. To overcome this limitation, here we describe XY-69, a fluorogenic reporter that preferentially partitions into membranes and provides a selective tool for measuring the real-time activity of PLCs as either purified enzymes or in cellular lysates. Indeed, XY-69 faithfully reported the membrane-dependent activation of PLC-ß3 by Gαq Therefore, XY-69 can replace radioactive phosphatidylinositol 4,5-bisphosphate used in conventional PLC assays and will enable high-throughput screens to identify both orthosteric and allosteric PLC inhibitors. In the future, cell-permeable variants of XY-69 represent promising candidates for reporting the activation of PLCs in live cells with high spatiotemporal resolution.