Orally Bioavailable Prodrugs of ψ-GSH: A Potential Treatment for Alzheimer's Disease.

Addressing glycation-induced oxidative stress in Alzheimer's disease (AD) is an emerging pharmacotherapeutic strategy. Restoration of the brain glyoxalase enzyme system that neutralizes reactive dicarbonyls is one such approach. Toward this end, we designed, synthesized, and evaluated a γ-glutamyl transpeptidase-resistant glyoxalase substrate, ψ-GSH. Although mechanistically successful, the oral efficacy of ψ-GSH appeared as an area in need of improvement. Herein, we describe our rationale for the creation of prodrugs that mask the labile sulfhydryl group. In vitro and in vivo stability studies identified promising prodrugs that could deliver pharmacologically relevant brain levels of ψ-GSH. When administered orally to a mouse model generated by the intracerebroventricular injection of Aß1-42, the compounds conferred cognitive benefits. Biochemical and histological examination confirmed their effects on neuroinflammation and oxidative stress. Collectively, we have identified orally efficacious prodrugs of ψ-GSH that are able to restore brain glyoxalase activity and mitigate inflammatory and oxidative pathology associated with AD.

γ-Glutamyl-Transpeptidase-Resistant Glutathione Analog Attenuates Progression of Alzheimer's Disease-like Pathology and Neurodegeneration in a Mouse Model.

Oxidative stress in Alzheimer's disease (AD) is mediated, in part, by the loss of glutathione (GSH). Previous studies show that γ-glutamyl transpeptidase (GGT)-resistant GSH analog, Ψ-GSH, improves brain GSH levels, reduces oxidative stress markers in brains of APP/PS1 transgenic mice, a mouse model of AD, and attenuates early memory deficits in the APP/PS1 model. Herein, we examined whether Ψ-GSH can attenuate the disease progression when administered following the onset of AD-like pathology in vivo. Cohorts of APP/PS1 mice were administered Ψ-GSH for 2 months starting at 8 month or 12 months of age. We show that Ψ-GSH treatment reduces indices of oxidative stress in older mice by restoration of enzyme glyoxalase-1 (Glo-1) activity and reduces levels of insoluble Aß. Quantitative neuropathological analyses show that Ψ-GSH treatment significantly reduces Aß deposition and brain inflammation in APP/PS1 mice compared to vehicle-treated mice. More importantly, Ψ-GSH treatment attenuated the progressive loss of cortical TH+ afferents and the loss of TH+ neurons in the locus coeruleus (LC). Collectively, the results show that Ψ-GSH exhibits significant antioxidant activity in aged APP/PS1 mice and chronic Ψ-GSH treatment administered after the onset of AD pathology can reverse/slow further progression of AD-like pathology and neurodegeneration in vivo.

Phosphoinositide 3-Kinase (PI3K) Reactive Oxygen Species (ROS)-Activated Prodrug in Combination with Anthracycline Impairs PI3K Signaling, Increases DNA Damage Response and Reduces Breast Cancer Cell Growth.

RIDR-PI-103 is a novel reactive oxygen species (ROS)-induced drug release prodrug with a self-cyclizing moiety linked to a pan-PI3K inhibitor (PI-103). Under high ROS, PI-103 is released in a controlled manner to inhibit PI3K. The efficacy and bioavailability of RIDR-PI-103 in breast cancer remains unexplored. Cell viability of RIDR-PI-103 was assessed on breast cancer cells (MDA-MB-231, MDA-MB-361 and MDA-MB-453), non-tumorigenic MCF10A and fibroblasts. Matrigel colony formation, cell proliferation and migration assays examined the migratory properties of breast cancers upon treatment with RIDR-PI-103 and doxorubicin. Western blots determined the effect of doxorubicin ± RIDR-PI-103 on AKT activation and DNA damage response. Pharmacokinetic (PK) studies using C57BL/6J mice determined systemic exposure (plasma concentrations and overall area under the curve) and T1/2 of RIDR-PI-103. MDA-MB-453, MDA-MB-231 and MDA-MB-361 cells were sensitive to RIDR-PI-103 vs. MCF10A and normal fibroblast. Combination of doxorubicin and RIDR-PI-103 suppressed cancer cell growth and proliferation. Doxorubicin with RIDR-PI-103 inhibited p-AktS473, upregulated p-CHK1/2 and p-P53. PK studies showed that ~200 ng/mL (0.43 µM) RIDR-PI-103 is achievable in mice plasma with an initial dose of 20 mg/kg and a 10 h T1/2. (4) The prodrug RIDR-PI-103 could be a potential therapeutic for treatment of breast cancer patients.

Sulfur-containing therapeutics in the treatment of Alzheimer's disease.

Sulfur is widely existent in natural products and synthetic organic compounds as organosulfur, which are often associated with a multitude of biological activities. OBenzothiazole, in which benzene ring is fused to the 4,5-positions of the thiazolerganosulfur compounds continue to garner increasing amounts of attention in the field of medicinal chemistry, especially in the development of therapeutic agents for Alzheimer's disease (AD). AD is a fatal neurodegenerative disease and the primary cause of age-related dementia posing severe societal and economic burdens. Unfortunately, there is no cure for AD. A lot of research has been conducted on sulfur-containing compounds in the context of AD due to their innate antioxidant potential and some are currently being evaluated in clinical trials. In this review, we have described emerging trends in the field, particularly the concept of multi-targeting and formulation of disease-modifying strategies. SAR, pharmacological targets, in vitro/vivo ADMET, efficacy in AD animal models, and applications in clinical trials of such sulfur compounds have also been discussed. This article provides a comprehensive review of organosulfur-based AD therapeutic agents and provides insights into their future development.

Oxidative Cyclization-Induced Activation of a Phosphoinositide 3-Kinase Inhibitor for Enhanced Selectivity of Cancer Chemotherapeutics.

In this work, we designed a prodrug that reacts with cellular oxidative equivalents leading to ether cleavage and cyclization to release an active phosphatidylinositol 3-kinase (PI3K) inhibitor. We show that the compound reduces affinity for PI3KA relative to the PI3K inhibitor, is slow to intercellularly oxidize, and is resistant to liver microsomes. We observed modest activity in untreated acute myeloid leukemia cells and 14-fold selectivity relative to non-cancerous cells. The cellular activity of the compound can be modulated by the addition of antioxidants or oxidants, indicating the compound activity is sensitive to cellular reactive oxygen species (ROS) state. Co-treatment with cytosine arabinoside or doxorubicin was used to activate the compound inside cells. We observed strong synergistic activity specifically in acute myeloid leukemia (AML) cancer cells with an increase in selective anticancer activity of up to 90-fold. Thus, these new self-cyclizing compounds can be used to increase the selectivity of anticancer agents.

Ureter tissue engineering with vessel extracellular matrix and differentiated urine-derived stem cells.

OBJECTIVE: To assess the possibility of ureter tissue engineering using vessel extracellular matrix (VECM) and differentiated urine-derived stem cells (USCs) in a rabbit model. METHODS: VECM was prepared by a modified technique. USCs were isolated from human urine samples and cultured with an induction medium for the differentiation of the cells into urothelium and smooth muscle phenotypes. For contractile phenotype conversion, the induced smooth muscle cells were transfected with the miR-199a-5p plasmid. The differentiated cells were seeded onto VECM and cultured under dynamic conditions in vitro for 2 weeks. The graft was tubularized and wrapped by two layers of the omentum of a rabbit for vascularization. Then, the maturated graft was used for ureter reconstruction in vivo. RESULTS: VECM has microporous structures that allow cell infiltration and exhibit adequate biocompatibility with seeding cells. USCs were isolated and identified by flow cytometry. After induction, the urothelium phenotype gene was confirmed at mRNA and protein levels. With the combined induction by TGF-ß1 and miR-199a-5p, the differentiated cells can express the smooth muscle phenotype gene and convert to the contractile phenotype. After seeding cells onto VECM, the induced urothelium cells formed a single epithelial layer, and the induced smooth muscle cells formed a few cell layers during dynamic culture. After 3 weeks of omental maturation, tubular graft was vascularized. At 2 months post ureter reconstruction, histological evaluation showed a clearly layered structure of ureter with multilayered urothelium over the organized smooth muscle tissue. CONCLUSION: By seeding differentiated USCs onto VECM, a tissue-engineered graft could form multilayered urothelium and organized smooth muscle tissue after ureteral reconstruction in vivo. STATEMENT OF SIGNIFICANCE: Cell-based tissue engineering offers an alternative technique for urinary tract reconstruction. In this work, we describe a novel strategy for ureter tissue engineering. We modified the techniques of vessel extracellular matrix (VECM) preparation and used a dynamic culture system for seeding cells onto VECM. We found that VECM had the trait of containing VEGF and exhibited blood vessel formation potential. Urine-derived stem cells (USCs) could be differentiated into urothelial cells and functional contractile phenotype smooth muscle cells in vitro. By seeding differentiated USCs onto VECM, a tissue-engineered graft could form multilayered urothelium and organized smooth muscle tissue after ureteral reconstruction in vivo. This strategy might be applied in clinical research for the treatment of long-segment ureteral defect.

UV cell stress induces oxidative cyclization of a protective reagent for DNA damage reduction in skin explants.

UV irradiation is a major driver of DNA damage and ultimately skin cancer. UV exposure leads to persistent radicals that generate ROS over prolonged periods of time. Toward the goal of developing long-lasting antioxidants that can penetrate skin, we have designed a ROS-initiated protective (RIP) reagent that, upon reaction with ROS (antioxidant activity), self-cyclizes and then releases the natural product apocynin. Apocynin is a known antioxidant and inhibitor of NOX oxidase enzymes. A key phenol on the compound 1 controls ROS-initiated cyclization and makes 1 responsive to ROS with a EC50 comparable to common antioxidants in an ABTS assay. In an in vitro DNA nicking assay, the RIP reagent prevented DNA strand breaks. In cell-based assays, the reagent was not cytotoxic, apocynin was released only in cells treated with UVR, reduced UVR-induced cell death, and lowered DNA lesion formation. Finally, topical treatment of human skin explants with the RIP reagent reduced UV-induced DNA damage as monitored by quantification of cyclobutane dimer formation and DNA repair signaling via TP53. The reagent was more effective than administration of a catalase antioxidant on skin explants. This chemistry platform will expand the types of ROS-activated motifs and enable inhibitor release for potential use as a long-acting sunscreen.

CRMP4a suppresses cell motility by sequestering RhoA activity in prostate cancer cells.

Objectives: Distant metastasis is a critical factor for cancer-associated death. Our previous studies identified collapsin response mediator protein 4a (CRMP4a) as a metastasis suppressor in prostate cancers. Enhancing CRMP4 expression by promoter-targeted small activating RNAs reduced cell migration in vitro and abolished distal metastasis in mouse xenograft models. In this study, we investigated the mechanism for CRMP4a-mediated suppression of cell migration. Methods: PC-3 cells were stably infected with lentiviruses expressing CRMP4a cDNA or a shRNA sequence. Cytoskeletal organization was analyzed by measuring cellular focal adhesion area and number, percentage of cell area and lamellipodia numbers after phalloidin staining or anti-vinculin immunocytofluorescent staining. Cell migration was evaluated with TranswellTM chambers coated with MatriGel. RhoA activation was determined with a Rhotekin RBD agarose bead-based assay kit. Lentiviruses harboring RhoA-Q63L or RhoA-T19N mutant constructs were used to overexpress mutant RhoA proteins. Results: CRMP4a overexpression largely reduced while CRMP4a knockdown remarkably increased cytoskeletal organization in PC-3 cells. CRMP4a immunoprecipitation pulled down RhoA but not cdc42 or Rac1 proteins. Manipulating CRMP4a expression levels reversely altered active RhoA levels. Overexpression of RhoA active (Q63L) but not inactive (T19N) mutants reversed CRMP4a-mediated reduction of cancer cell migration while RhoA inhibitor Rhosin diminished CRMP4a shRNA-induced increase of cancer cell migration. CRMP4a overexpression also largely reduced cell spreading that was abolished by overexpressing RhoA active mutant. Conclusion: Our data demonstrated that CRMP4a interacts with RhoA and sequesters its activity, resulting in suppression of cytoskeletal organization, cell migration and spreading.

Comparison of intrafascial and non-intrafascial radical prostatectomy for low risk localized prostate cancer.

In this meta-analysis study, we compared the oncological and functional outcomes of intrafascial radical prostatectomy (IFRP) with non-intrafascial radical prostatectomy (NIFRP) in the treatment of patients with low risk localized prostate cancer (PCa). Relevant articles were identified by searching PubMed, EMBASE, Cochrane Library, Ovid, and the ISI Web of Knowledge databases. A total of 2096 patients were included from 7 eligible studies. Results of the pooled data showed that the oncological outcomes including gleason score, positive surgical margin and biochemical free survival rates were similar between the two groups. IFRP was superior to NIFRP with lower postoperative complication rates (RR 0.57, 95% CI 0.38, 0.85, p = 0.006), higher continence rates at 3 months post-operation (RR: 1.14; 95% CI, 1.04, 1.26; p = 0.006), and higher potency rates at 6 months (RR: 1.53; 95% CI, 1.07, 2.18; p = 0.02) and 12 months post-operation (RR: 1.38; 95% CI, 1.11, 1.73; p = 0.005). Additionally, there was a tendency towards higher potency rate in patients ≤65 years old compared with patients >65 years old after IFRP. Overall, these findings suggest that IFRP in young patients with low risk localized PCa had less postoperative complications, shortened time to return to continence and improved potency rate without compromising complete tumor control.

Self-Cyclizing Antioxidants to Prevent DNA Damage Caused by Hydroxyl Radical.

Antioxidant therapy is a promising treatment strategy for protecting DNA from the damage caused by reactive oxygen species (ROS). Here, we report new self-cyclizing antioxidant reagents that are selective for the hydroxyl radical. Our mechanistic investigation revealed that the reagents react with three equivalents of oxidant in a cascade reaction to form a bicyclic final product. Among the reagents synthesized, 1 c showed favorable properties in vitro and in cellular studies. Using As2 O3 , which triggers ROS production, we showed that 1 c prevents formation of the guanine oxidation product 2,2,4-triamino-2H-oxazol-5-one-2'-deoxyribonucleoside and lowers cellular levels of reactive oxygen. The described self-cyclizing antioxidants are efficient, flexible, and tunable reagents with the potential to limit toxic oxidative stress.

Selective hydrogenation of nitroaromatics by ceria nanorods.

Ceria (CeO2) nanorods with well-defined surface planes can be synthesized and utilized for the hydrogenation of nitroaromatics. The CeO2 nanorods containing a {110} plane can efficiently and selectively catalyse the hydrogenation of nitroaromatics with N2H4 as a reducing agent, while nano-ceria with a {100} or {111} plane shows poor performance for the reaction.

Intrinsic Peroxidase Catalytic Activity of Fe7 S8 Nanowires Templated from [Fe16 S20 ]/Diethylenetriamine Hybrid Nanowires.

Iron sulfide compounds are emerging as an important family of functional materials owing to their important properties and their applications in different technical fields. Well-defined Fe7 S8 nanowires templated by thermal decomposition of [Fe16 S20 ]/diethylenetriamine hybrid nanowires under an argon atmosphere are reported. As-prepared Fe7 S8 nanowires show typical Michaelis-Menten kinetics and good affinity to both H2 O2 and 3,3',5,5'-tetramethylbenzidine. At pH 7.0, the constructed UV/Vis sensor showed a linear range for the detection of H2 O2 from 0.5 to 150 µM with a correlation coefficient of 0.9998. The H2 O2 sensor based on the Fe7 S8 nanowires shows a highly sensitive response and has better stability than horseradish peroxidase when exposed to solutions with different pH values and temperatures. These excellent properties make the as-prepared Fe7 S8 nanowires powerful tools for potential applications as an "artificial peroxidase" in biosensors and biotechnology.

Carbonaceous nanofiber membrane functionalized by beta-cyclodextrins for molecular filtration.

In this paper, we report the fabrication of carbonaceous nanofiber (CNF) membranes functionalized by beta-cyclodextrins (CNF-ß-CD membrane) and their application for molecular filtration. The chemically synthesized carbonaceous nanofibers were first functionalized by ß-CD, and the free-standing CNF membrane can be prepared by a simple filtration process. The membrane shows a remarkable capability to function as an ideal molecular filter through complexation of phenolphthalein molecules with the cyclodextrin molecules grafted on the CNFs. As a typical dye pollutant, fuchsin acid can also be effectively removed from the solution through such a membrane. Engineering the surface of this carbonaceous nanofiber membrane may allow it to be used for other applications such as chiral separation and drug delivery.

Selective chromogenic detection of thiol-containing biomolecules using carbonaceous nanospheres loaded with silver nanoparticles as carrier.

Thiol-containing biomolecules show strong affinity with noble metal nanostructures and could not only stably protect them but also control the self-assembly process of these special nanostructures. A highly selective and sensitive chromogenic detection method has been designed for the low and high molecular weight thiol-containing biomolecules, including cysteine, glutathione, dithiothreitol, and bovine serum albumin, using a new type of carbonaceous nanospheres loaded with silver nanoparticles (Ag NPs) as carrier. This strategy relies upon the place-exchange process between the reporter dyes on the surface of Ag NPs and the thiol groups of thiol-containing biomolecules. The concentration of biomolecules can be determined by monitoring with the fluorescence intensity of reporter dyes dispersed in solution. This new chromogenic assay method could selectively detect these biomolecules in the presence of various other amino acids and monosaccharides and even sensitively detect the thiol-containing biomolecules with different molecular weight, even including proteins.

[Effects of behind legs vibrations on erectile function in male rabbits].

OBJECTIVE: To study the effects of behind legs vibrations on erectile function in male rabbits through the concentration of plasma reproductive hormone and the expression of nitric oxide synthase (eNOS), endothelin-1 (ET-1) mRNA in vibrated male rabbits. METHODS: 30 male adult rabbits were assigned randomly to A group (vibration power: 3.02 m/s(2)), B group (vibration power: 6.13 m/s(2)), C group (vibration power: 12.26 m/s(2)) and control group. The concentration of expression of eNOS, ET-1 mRNA were measured with RT-PCR after rated for 30 days. RESULTS: (1) Compared with 0 days vibration, after exposure to vibration for 10, 20, 30 days, the A, B, C group concentration of plasma T, LH are much lower (P < 0.05), the concentration of plasma E2 is much higher. (2) Compared with control group after exposed for 30 days, the expression of ET-1 mRNA [B group:(17.39 +/- 4.59) x 104; C group: (36.21 +/- 13.13) x 104 ] were much higher and expression of eNOS mRNA [A group: (19.11 +/- 6.83) x 104; B group: (11.86 +/- 3.15) x 104; C group: (4.68 +/- 3.26) x 104] was much lower, there were significant differences (P < 0.01). CONCLUSIONS: The vibration of behind legs in rabbits resulted the concentration of plasma T, LH are much lower, the concentration of plasma E2 is much higher, increased the expression of eNOS mRNA, decreased the expression of eNOS mRNA, then vary the erectile function.

[Exploration for building PACS and RIS].

This article elaborates key points of the PACS and RIS project: its overall planning, implementation step by step, integration of PACS and HIS based on IHE, and the prudent selection of partners and so on.