Uncovering novel drug targets for bipolar disorder: a Mendelian randomization analysis of brain, cerebrospinal fluid, and plasma proteomes.

BACKGROUND: There is a clear demand for innovative therapeutics for bipolar disorder (BD). METHODS: We integrated the largest BD genome-wide association study (GWAS) dataset (NCase = 41 917, NControl = 371 549) with protein quantitative trait loci from brain, cerebrospinal fluid, and plasma. Using a range of integrative analyses, including Mendelian randomization (MR), Steiger filter analysis, Bayesian colocalization, and phenome-wide MR analysis, we prioritized novel drug targets for BD. Additionally, we incorporated data from the UK Biobank (NCase = 1064, NControl = 365 476) and the FinnGen study (NCase = 7006, NControl = 329 192) for robust biological validation. RESULTS: Through MR analysis, we found that in the brain, downregulation of DNM3, MCTP1, ABCB8 and elevation of DFNA5 and PDF were risk factors for BD. In cerebrospinal fluid, increased BD risk was associated with increased levels of FRZB, AGRP, and IL36A and decreased CTSF and LRP8. Plasma analysis revealed that decreased LMAN2L, CX3CL1, PI3, NCAM1, and TIMP4 correlated with increased BD risk, but ITIH1 did not. All these proteins passed Steiger filtering, and Bayesian colocalization confirmed that 12 proteins were colocalized with BD. Phenome-wide MR analysis revealed no significant side effects for potential drug targets, except for LRP8. External validation further underscored the concordance between the primary and validation cohorts, confirming MCTP1, DNM3, PDF, CTSF, AGRP, FRZB, LMAN2L, NCAM1, and TIMP4 are intriguing targets for BD. CONCLUSIONS: Our study identified druggable proteins for BD, including MCTP1, DNM3, and PDF in the brain; CTSF, AGRP, and FRZB in cerebrospinal fluid; and LMAN2L, NCAM1, and TIMP4 in plasma, delineating promising avenues to development of novel therapies.

Bioinspired Engineering of Fillable Gradient Structure into Flexible Capacitive Pressure Sensor Toward Ultra-High Sensitivity and Wide Working Range.

Tactile sensing is required for electronic skin and intelligent robots to function properly. However, the dielectric layer's poor structural compressibility in conventional pressure sensors results in a limited pressure sensing range and low sensitivity. To solve this issue, a flexible pressure sensor with a crocodile-inspired fillable gradient structure is provided. The fillable gradient structure and grooves in the pressure sensor accommodate the deformed microstructure that permits the enhancement of the media layer compressibility via COMSOL finite element simulation and optimization. The pressure sensor exhibits a high sensitivity of up to 0.97 k Pa-1 (0-4 kPa), a wide pressure detection range (7 Pa-380 kPa), and outstanding repeatability. The sensor can detect Morse code, robotic grabbing, and human motion monitoring. As a result, flexible sensors with a bionic fillable gradient structure pave the way for wearable devices and offer a novel method for achieving highly precise tactile perception.

Novel synthesis of reed flower-like SmMnOx catalyst with enhanced low-temperature activity and SO2 resistance for NH3-SCR.

In this work, a novel co-precipitation coupled solvothermal procedure is proposed to prepare a SmMnOx catalyst (SmMnOx-CP + ST) with a reed flower-like structure for the selective catalytic reduction of NOx by NH3 (NH3-SCR). Over 90% NOx conversion and N2 selectivity was achieved at a low temperature range (25-200 °C), and 96% NOx conversion was achieved in the presence of 100 ppm SO2 at 75 °C. While the NH3-SCR of the SmMnOx catalysts prepared by co-precipitation (SmMnOx-CP) and solvothermal (SmMnOx-ST) methods performed much poorer than the SmMnOx-CP + ST catalyst. All catalysts were characterized by XRD, BET, SEM, XPS, H2-TPR, NH3-TPD, NOx-TPD, and FT-IR. The results revealed that the superior performance of the SmMnOx-CP + ST is due to the unique reed flower-like structure morphology, which endows the SmMnOx-CP + ST with the largest surface area, the strongest synergistic reaction of Sm and Mn, abundant surface oxygen species and surface active sites, and significantly enhances the redox ability. Furthermore, the amorphous reed flower-like structure showed strong short-range ordered interaction between the active components and weaken the formation of sulfates species. In addition, the highest content of Mn4+ and Mn3++Mn4+ greatly promotes the redox cycles of Sm2+↔Mn4+ and Sm2+↔Mn3+, and suppresses the production of sulfate species in the presence of SO2.

Physiological oxygen prevents frequent silencing of the DLK1-DIO3 cluster during human embryonic stem cells culture.

Genetic and epigenetic alterations are observed in long-term culture (>30 passages) of human embryonic stem cells (hESCs); however, little information is available in early cultures. Through a large-scale gene expression analysis between initial-passage hESCs (ihESCs, <10 passages) and early-passage hESCs (ehESCs, 20-30 passages) of 12 hESC lines, we found that the DLK1-DIO3 gene cluster was normally expressed and showed normal methylation pattern in ihESC, but was frequently silenced after 20 passages. Both the DLK1-DIO3 active status in ihESCs and the inactive status in ehESCs were inheritable during differentiation. Silencing of the DLK1-DIO3 cluster did not seem to compromise the multilineage differentiation ability of hESCs, but was associated with reduced DNA damage-induced apoptosis in ehESCs and their differentiated hepatocyte-like cell derivatives, possibly through attenuation of the expression and phosphorylation of p53. Furthermore, we demonstrated that 5% oxygen, instead of the commonly used 20% oxygen, is required for preserving the expression of the DLK1-DIO3 cluster. Overall, the data suggest that active expression of the DLK1-DIO3 cluster represents a new biomarker for epigenetic stability of hESCs and indicates the importance of using a proper physiological oxygen level during the derivation and culture of hESCs.

Biochemical characterization of prostate-specific membrane antigen from canine prostate carcinoma cells.

BACKGROUND: Prostate-specific membrane antigen (PSMA) remains an important target for diagnostic and therapeutic application for human prostate cancer. Model cell lines have been recently developed to study canine prostate cancer but their PSMA expression and enzymatic activity have not been elucidated. The present study was focused on determining PSMA expression in these model canine cell lines and the use of fluorescent small-molecule enzyme inhibitors to detect canine PSMA expression by flow cytometry. METHODS: Western blot and RT-PCR were used to determine the transcriptional and translational expression of PSMA on the canine cell lines Leo and Ace-1. An endpoint HPLC-based assay was used to monitor the enzymatic activity of canine PSMA and the potency of enzyme inhibitors. Flow cytometry was used to detect the PSMA expressed on Leo and Ace-1 cells using a fluorescently tagged PSMA enzyme inhibitor. RESULTS: Canine PSMA expression on the Leo cell line was confirmed by Western blot and RT-PCR, the enzyme activity, and flow cytometry. Kinetic parameters Km and Vmax of PSMA enzymatic activity for the synthetic substrate (PABGγG) were determined to be 393 nM and 220 pmol min(-1) mg protein(-1) , respectively. The inhibitor core 1 and fluorescent inhibitor 2 were found to be potent reversible inhibitors (IC50 = 13.2 and 1.6 nM, respectively) of PSMA expressed on the Leo cell line. Fluorescent labeling of Leo cells demonstrated that the fluorescent PSMA inhibitor 2 can be used for the detection of PSMA-positive canine prostate tumor cells. Expression of PSMA on Ace-1 was low and not detectable by flow cytometry. CONCLUSIONS: The results described herein have demonstrated that PSMA is expressed on canine prostate tumor cells and exhibits similar enzymatic characteristics as human PSMA. The findings show that the small molecule enzyme inhibitors currently being studied for use in diagnosis and therapy of human prostate cancer can also be extended to include canine prostate cancer. Importantly, the findings demonstrate that the potential of the inhibitors for use in diagnosis and therapy can be evaluated in an immunocompetent animal model that naturally develops prostate cancer before use in humans.

Compositional, Structural, and Biomechanical Properties of Three Different Soft Tissue-Hard Tissue Insertions: A Comparative Review.

Connective tissue attaches to bone across an insertion with spatial gradients in components, microstructure, and biomechanics. Due to regional stress concentrations between two mechanically dissimilar materials, the insertion is vulnerable to mechanical damage during joint movements and difficult to repair completely, which remains a significant clinical challenge. Despite interface stress concentrations, the native insertion physiologically functions as the effective load-transfer device between soft tissue and bone. This review summarizes tendon, ligament, and meniscus insertions cross-sectionally, which is novel in this field. Herein, the similarities and differences between the three kinds of insertions in terms of components, microstructure, and biomechanics are compared in great detail. This review begins with describing the basic components existing in the four zones (original soft tissue, uncalcified fibrocartilage, calcified fibrocartilage, and bone) of each kind of insertion, respectively. It then discusses the microstructure constructed from collagen, glycosaminoglycans (GAGs), minerals and others, which provides key support for the biomechanical properties and affects its physiological functions. Finally, the review continues by describing variations in mechanical properties at the millimeter, micrometer, and nanometer scale, which minimize stress concentrations and control stretch at the insertion. In summary, investigating the contrasts between the three has enlightening significance for future directions of repair strategies of insertion diseases and for bioinspired approaches to effective soft-hard interfaces and other tough and robust materials in medicine and engineering.

Catalytic hydrolysis of monochlorodifluoromethane over ZnO/ZrO2 catalysts at low temperatures.

Monochlorodifluoromethane (HCFC-22) has been identified as a significant contributor to the depletion of the Earth's ozone layer, garnering considerable attention within the scientific community. Consequently, the investigation of Freon degradation has become a central focus of current research efforts. In this study, we opted to employ catalytic hydrolysis as it offers numerous advantages for the degradation of HCFC-22. Specifically, we prepared ZnO/ZrO2 catalysts with hexahedral rod-like structures through citric acid complexation. We examined the impact of various preparation conditions (such as the molar ratio of ZnO to ZrO2, calcination temperature, and calcination time) as well as catalytic hydrolysis conditions (including the amount of catalyst, total flow rate, and catalytic hydrolysis temperature) on the hydrolysis rate of HCFC-22. Characterization of the catalysts was performed using techniques such as XRD, SEM, EDS, TG-DTG, FTIR, N2 adsorption-desorption, CO2-TPD, and NH3-TPD. Our experimental findings revealed the optimal preparation conditions: a catalytic hydrolysis temperature of 100 °C, a molar ratio of ZnO to ZrO2 of 0.7, a water bath temperature of 90 °C, a roasting temperature of 400 °C, and a roasting time of 4 h. At a catalytic hydrolysis temperature of 100 °C, the hydrolysis rate of HCFC-22 reached 99.81%, with the main hydrolyzed products being HCl, HF, and CO2.

Crocin alleviates neurotoxicity induced by bupivacaine in SH-SY5Y cells with inhibition of PI3K/AKT signaling.

BACKGROUND: Bupivacaine, a common local anesthetic, can cause neurotoxicity and permanent neurological disorders. Crocin has been widely reported as a potential neuroprotective agent in neural injury models. OBJECTIVE: The aim of this study was to investigate the role and regulatory mechanism of crocin underlying bupivacaine-induced neurotoxicity. METHOD: Human neuroblastoma SH-SY5Y cells were treated with bupivacaine and/or crocin for 24 h, followed by detecting cell viability using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The effect of crocin or bupivacaine on SH-SY5Y cell proliferation was measured by Ki67 immunofluorescence assay. The levels of apoptosis-related proteins and the markers in the PI3K/Akt signaling pathway were examined using western blot analysis. The activities of caspase 3, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were tested using respective commercial assay kits. Flow cytometry analysis was executed for detecting SH-SY5Y cell apoptosis. RESULT: Crocin attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells. Meanwhile, crocin inhibited SH-SY5Y cell apoptosis induced by bupivacaine via repressing the activity of caspase-3, reducing Bax expression, and elevating Bcl-2 expression. Moreover, crocin mitigated oxidative stress in SH-SY5Y cells by increasing the content of CAT, SOD, GSH-Px and reducing the content of MDA. Additionally, crocin protected against bupivacaine-induced dephosphorylation of Akt and GSK-3ß. The protective effects of crocin against bupivacaine-induced neurotoxicity in SH-SY5Y cells were counteracted by the Akt inhibitor. CONCLUSION: These results suggested that crocin may exert a neuroprotective function by promoting cell proliferation and suppressing apoptosis and oxidative stress in SH-SY5Y cells. Thus, crocin might become a promising drug for the treatment of bupivacaine-induced neurotoxicity.

HE4 Serum Levels are Associated with Poor Prognosis in Patients with Acute Heart Failure Combined with Chronic Kidney Disease.

Purpose: The levels of human epididymis protein 4 (HE4) is associated not only with the prognosis of patients with acute heart failure (AHF), but also with chronic kidney disease (CKD). Our study aims to understand the prediction value of HE4 on prognosis in patients with AHF combined with CKD. Patients and Methods: This study prospectively enrolled patients diagnosed with AHF combined with CKD at the Department of Cardiology of Hunan Provincial People's Hospital from March 2019 to December 2022. Serum levels of HE4 were measured using a chemiluminescence microparticle immunoassay. The endpoint events included heart failure readmission and cardiovascular death. Results: A total of 130 patients with AHF combined with CKD were included in the stud. The median age is 73 years (interquartile range: 65-79 years). Among the patients, 94 experienced the endpoint events. The multivariable Cox analysis reveals that LnHE4 (HR=2.280, 95% CI 1.300-3.998, P = 0.004) and age (HR=1.024, 95% CI 1.003-1.045, P = 0.025) are independent predictors of the endpoint events. The Kaplan-Meier survival curve demonstrates that patients with HE4 levels>276.15 pmol/L has a significantly higher incidence of endpoint events compared to those with HE4 levels≤276.15 pmol/L (Log rank test: χ2=19.689, P < 0.001). After adjusting for age and gender, the HR is 2.520 (95% CI: 1.626-3.906, P < 0.001). Conclusion: HE4 is an independent predictor of heart failure readmission and cardiovascular death in patients with AHF combined with CKD.

Targeting prostate cancer cells with PSMA inhibitor-guided gold nanoparticles.

Prostate-specific membrane antigen (PSMA) is a notable biomarker for diagnostic and therapeutic applications in prostate cancer. Gold nanoparticles (AuNPs) provide an attractive nanomaterial platform for combining a variety of targeting, imaging, and cytotoxic agents into a unified device for biomedical research. In this study, we present the generation and evaluation of the first AuNP system functionalized with a small molecule phosphoramidate peptidomimetic inhibitor for the targeted delivery to PSMA-expressing prostate cancer cells. The general approach involved the conjugation of streptavidin-coated AuNPs with a biotin-linked PSMA inhibitor (CTT54) to generate PSMA-targeted AuNPs. In vitro evaluations of these targeted AuNPs were conducted to determine PSMA-mediated and time-dependent binding to PSMA-positive LNCaP cells. The PSMA-targeted AuNPs exhibited significantly higher and selective binding to LNCaP cells compared to control non-targeted AuNPs, thus demonstrating the feasibility of this approach.

Versatile Protein and Its Subunit Biomolecules for Advanced Rechargeable Batteries.

Rechargeable batteries are of great significance for alleviating the growing energy crisis by providing efficient and sustainable energy storage solutions. However, the multiple issues associated with the diverse components in a battery system as well as the interphase problems greatly hinder their applications. Proteins and their subunits, peptides, and amino acids, are versatile biomolecules. Functional groups in different amino acids endow these biomolecules with unique properties including self-assembly, ion-conducting, antioxidation, great affinity to exterior species, etc. Besides, protein and its subunit materials can not only work in solid forms but also in liquid forms when dissolved in solutions, making them more versatile to realize materials engineering via diverse approaches. In this review, it is aimed to offer a comprehensive understanding of the properties of proteins and their subunits, and research progress of using these versatile biomolecules to address the engineering issues of various rechargeable batteries, including alkali-ion batteries, lithium-sulfur batteries, metal-air batteries, and flow batteries. The state-of-the-art advances in electrode, electrolyte, separator, binder, catalyst, interphase modification, as well as recycling of rechargeable batteries are involved, and the impacts of biomolecules on electrochemical properties are particularly emphasized. Finally, perspectives on this interesting field are also provided.

Formaldehyde Oxidation of Ce0.8Zr0.2O2 Nanocatalysts for Room Temperature: Kinetics and Effect of pH Value.

Ce0.8Zr0.2O2 catalysts were prepared via the co-precipitation method under different pH conditions. The catalysts were characterized via TEM, XRD, XPS, BET, Raman, and FTIR. The oxidation performance of formaldehyde was tested. Precipitation pH affects the physicochemical properties and performance of the Ce0.8Zr0.2O2 catalyst. By controlling the precipitation pH at 10.5, the Ce0.8Zr0.2O2 catalyst with the largest specific surface area, the smallest grain size with the best formaldehyde removal rate (98.85%), abundant oxygen vacancies, and the best oxidation performance were obtained. Meanwhile, the kinetic parameters of the catalyst were experimentally investigated and the calculated activation energy was 12.6 kJ/mol and the number of reaction steps was 1.4 and 1.2.

Urolithin A alleviates early brain injury after subarachnoid hemorrhage by regulating the AMPK/mTOR pathway-mediated autophagy.

OBJECTIVE: Unfavorable outcomes in patients with subarachnoid hemorrhage (SAH) are mainly attributed to early brain injury (EBI). Reduction of neuronal death can improve the prognosis in SAH patients. Autophagy and apoptosis are critical players in neuronal death. Urolithin A (UA) is a natural compound produced by gut bacteria from ingested ellagitannins and ellagic acid. Here, we detected the role of UA in EBI post-SAH. METHODS: We established an animal model of SAH in rats by endovascular perforation, with administration of UA, 3-methyladenine (3-MA) and Compound C. SAH grading, neurological function, brain water content, western blotting analysis of levels of proteins related to apoptosis, autophagy and pathways, blood-brain barrier (BBB) integrity, TUNEL staining, and immunofluorescence staining of LC3 were evaluated at 24h after SAH. RESULTS: SAH induction led to neurological dysfunctions, BBB disruption, and cerebral edema at 24h post-SAH in rats, which were relieved by UA. Additionally, cortical neuronal apoptosis in SAH rats was also attenuated by UA. Moreover, UA restored autophagy level in SAH rats. Mechanistically, UA activated the AMPK/mTOR pathway. Furthermore, inhibition of autophagy and AMPK limited UA-mediated protection against EBI post-SAH CONCLUSION: UA alleviates neurological deficits, BBB permeability, and cerebral edema by inhibiting cortical neuronal apoptosis through regulating the AMPK/mTOR pathway-dependent autophagy in rats following SAH.

Mitigating Lattice Distortion of High-Voltage LiCoO2 via Core-Shell Structure Induced by Cationic Heterogeneous Co-Doping for Lithium-Ion Batteries.

Inactive elemental doping is commonly used to improve the structural stability of high-voltage layered transition-metal oxide cathodes. However, the one-step co-doping strategy usually results in small grain size since the low diffusivity ions such as Ti4+ will be concentrated on grain boundaries, which hinders the grain growth. In order to synthesize large single-crystal layered oxide cathodes, considering the different diffusivities of different dopant ions, we propose a simple two-step multi-element co-doping strategy to fabricate core-shell structured LiCoO2 (CS-LCO). In the current work, the high-diffusivity Al3+/Mg2+ ions occupy the core of single-crystal grain while the low diffusivity Ti4+ ions enrich the shell layer. The Ti4+-enriched shell layer (~ 12 nm) with Co/Ti substitution and stronger Ti-O bond gives rise to less oxygen ligand holes. In-situ XRD demonstrates the constrained contraction of c-axis lattice parameter and mitigated structural distortion. Under a high upper cut-off voltage of 4.6 V, the single-crystal CS-LCO maintains a reversible capacity of 159.8 mAh g-1 with a good retention of ~ 89% after 300 cycles, and reaches a high specific capacity of 163.8 mAh g-1 at 5C. The proposed strategy can be extended to other pairs of low- (Zr4+, Ta5+, and W6+, etc.) and high-diffusivity cations (Zn2+, Ni2+, and Fe3+, etc.) for rational design of advanced layered oxide core-shell structured cathodes for lithium-ion batteries.

Supported Ruthenium Single-Atom and Clustered Catalysts Outperform Benchmark Pt for Alkaline Hydrogen Evolution.

Guaranteeing satisfactory catalytic behavior while ensuring high metal utilization has become the problem that needs to be addressed when designing noble-metal-based catalysts for electrochemical reactions. Here, well-dispersed ruthenium (Ru) based clusters with adjacent Ru single atoms (SAs) on layered sodium cobalt oxide (Ru/NC) are demonstrated as a superb electrocatalyst for alkaline HER. The Ru/NC catalyst demonstrates an activity increase by a factor of two relative to the commercial Pt/C. Operando characterizations in conjunction with density functional theory (DFT) simulations uncover the origin of the superior activity and establish a structure-performance relationship, that is, under HER condition, the real active species are Ru SAs and metallic Ru clusters supported on the NC substrate. The excellent alkaline HER activity of the Ru/NC catalyst can be understood by a spatially decoupled water dissociation and hydrogen desorption mechanism, where the NC substrate accelerates the water dissociation rate, and the generated H intermediates would then migrate to the Ru SAs or clusters and recombine to have H2 evolution. More importantly, comparing the two forms of Ru sites, it is the Ru cluster that dominates the HER activity.

Dramatic improvement in the stability and mechanism of high-performance inverted polymer solar cells featuring a solution-processed buffer layer.

In this study, we demonstrate inverted PTB7:PC71BM polymer solar cells (PSCs) featuring a solution-processed s-MoO3 hole transport layer (HTL) that can, after thermal aging at 85 °C, retain their initial power conversion efficiency (PCE) for at least 2200 h. The T80 lifetimes of the PSCs incorporating the novel s-MoO3 HTL were up to ten times greater than those currently reported for PTB7- or low-band-gap polymer:PCBM PSCs, the result of the inhibition of burn-in losses and long-term degradation under various heat-equivalent testing conditions. We used X-ray photoelectron spectroscopy (XPS) to study devices containing thermally deposited t-MoO3 and s-MoO3 HTLs and obtain a mechanistic understanding of how the robust HTL is formed and how it prevented the PSCs from undergoing thermal degradation. Heat tests revealed that the mechanisms of thermal inter-diffusion and interaction of various elements within active layer/HTL/Ag electrodes controlled by the s-MoO3 HTL were dramatically different from those controlled by the t-MoO3 HTL. The new prevention mechanism revealed here can provide the conceptual strategy for designing the buffer layer in the future. The PCEs of PSCs featuring s-MoO3 HTLs, measured in damp-heat (65 °C/65% RH; 85 °C per air) and light soaking tests, confirmed their excellent stability. Such solution-processed MoO3 HTLs appear to have great potential as replacements for commonly used t-MoO3 HTLs.

Chemoaffinity capture of pre-targeted prostate cancer cells with magnetic beads.

BACKGROUND: Prostate circulating tumor cells (PCTCs) in circulation are shed from either a primary tumor or metastases, which are directly responsible for most prostate cancer deaths. Quantifying exfoliated PCTCs may serve as an indicator for the clinical management of prostate cancer, isolating and removing of PCTCs could potentially reduce prostate cancer metastasis, and culturing and characterizing captured PCTCs could facilitate the development of personalized treatment options. Prostate-specific membrane antigen (PSMA) is an established biomarker for prostate cancer being strongly expressed on prostate tumor cells associated with high-grade primary, androgen independent, and metastatic tumors. METHODS: Suspensions of PSMA+ (LNCaP) cells were pre-targeted with the irreversible PSMA inhibitor biotin-PEG(12)-CTT-54 to serve as a bait to capture PSMA+ cells using streptavidin-coated magnetic beads. Decreasing numbers of LNCaP cells were spiked into blood to determine the cell captured efficiency, recovery and viability. RESULTS: High selectivity, recovery, and viability were achieved for the capture of PSMA+ cells in both model experiments with mixtures of LNCaP cells and WBCs as well as blood samples spiked with LNCaP cells. As low as 10 cells were captured from 1 ml of blood with nearly 90% viability. More importantly, captured cells could be subsequently propagated in vitro. CONCLUSIONS: This methodology for the detection, isolation, and culture of PCTCs from peripheral blood can serve as an effective tool for the detection of metastatic prostate cancer, treatment monitoring, and the development of personalized therapy based on the responsiveness of PCTCs to chemotherapeutic strategies.

A phosphoramidate-based prostate-specific membrane antigen-targeted SPECT agent.

BACKGROUND: Prostate-specific membrane antigen (PSMA) remains an active target for imaging and therapeutic applications for prostate cancer. METHODS: In the present study, an irreversible phosphoramidate inhibitor, CTT-54 (IC50 = 14 nM), has been modified to deliver 99mTc-(CO)3-DTPA as a SPECT imaging payload to PSMA+ cells in vivo and in vitro. Percent uptake, competitive binding, and internalization will evaluate the imaging agent in vitro. Preliminary biodistribution and imaging will be utilized for in vivo evaluation. RESULTS: In vitro studies demonstrate that the radiotracer 99mTc-(CO)3-DTPA-CTT-54 exhibits increasing cellular uptake in the PSMA+ LNCaP cells over time. More importantly, it was found that 99mTc-(CO)3-DTPA-CTT-54 is rapidly internalized into LNCaP cells, presumably through the PSMA enzyme-inhibitor complex. In a pilot biodistribution study, increasing accumulation of the radiotracer in LNCaP xenografts was observed from 2 to 4 hr and significant clearance from non-target tissues. CONCLUSIONS: While DTPA may not represent the ideal chelate structure for 99mTc(CO)3, the data provides proof-of-concept support for the development of a next-generation phosphoramidate-based PSMA inhibitor-conjugates for use as SPECT imaging agents.

Targeting prostate cancer cells with a multivalent PSMA inhibitor-guided streptavidin conjugate.

Prostate-specific membrane antigen (PSMA), a type II membrane glycoprotein, its high expression is associated with prostate cancer progression, and has been becoming an active target for imaging or therapeutic applications for prostate cancer. On the other hand, streptavidin-biotin system has been successfully employed in pretargeting therapy towards multiple cancers. Herein, we describe the synthesis of bifunctional ligands (biotin-CTT54, biotin-PEG(4)-CTT54, and biotin-PEG(12)-CTT54) possessing two functional motifs separated by a length-varied polyethylene glycol (PEG) spacer: one (CTT54) binds tumor-marker PSMA and the other (biotin) binds streptavidin or avidin. All three compounds exhibited high potencies (IC(50) values: 1.21, 2.53, and 10nM, respectively) and irreversibility; but only biotin-PEG(12)-CTT54 demonstrated specifically labeling PSMA-positive prostate cancer cells in a two-step pretargeting procedure. Additionally, the pre-formulated complex between biotin-PEG(12)-CTT54 and Cy5-streptavidin displayed the improved inhibitory potency (IC(50)=1.86 nM) and irreversibility against PSMA and rapid uptake of streptavidin conjugate into PSMA-positive prostate cancer cells through PSMA-associated internalization. Together, all these results supported a proof-concept that combination of streptavidin and PSMA's biotinylated inhibitor may lead to development of a novel strategy of tumor-targeting imaging or drug delivery towards prostate cancer.

Identification and evaluation of apoptotic compounds from Garcinia oligantha.

Four new compounds, oliganthins A-D (1-4), and one known caged xanthone gaudichaudione H (5) were isolated from the stems of Garcinia oligantha. The structures of the new compounds were elucidated by spectroscopic evidences. All of the five compounds were evaluated for their apoptosis-inducing effects using HeLa-C3 cells which have been genetically engineered to produce a fluorescent biosensor capable of detecting caspase-3 activation. All of them induced cell apoptosis at 10 µM or lower concentrations. The apoptotic activity of oliganthins A, B and gaudichaudione H were further confirmed by detecting the cleavage of PARP, which is the substrate of activated caspase-3, in these compounds-treated cells using the method of Western blot. Moreover, the values of IC(50) were measured for all five compounds on HeLa cells using the MTT assay. Among them, gaudichaudione H had the lowest IC(50) value of 0.90 µM, while the other four new compounds had IC(50) values of 1.58, 1.52, 4.15, and 7.82 µM, respectively. These results show that gaudichaudione H has the strongest apoptosis-inducing effect and cell growth inhibition effect among these xanthones and it may have the potential to be developed into a new anticancer agent.