Ruxolitinib-based combinations in the treatment of myelofibrosis: worth looking forward to.

Ruxolitinib is a targeted drug to treat myelofibrosis (MF). Ruxolitinib has significant advantages in spleen reduction and increasing 5-year overall survival (OS), and ruxolitinib-based combinations might provide more benefits than ruxolitinib monotherapy. In this review, we focus on the data of ruxolitinib-based combinations therapies and treatment-related adverse events (AEs) and safety. We analyzed and summarized the data of ruxolitinib-based combinations. Ruxolitinib combined with prednisone + thalidomide + danazol (TPD), panobinostat, pracinostat, azacytidine, or hydroxyurea has well reduced spleen. Ruxolitinib combined with danazol or TPD had well therapies in improvement of hemoglobin (Hgb) and platelets (PLT). Most ruxolitinib-based combinations therapies showed a superior benefit on reduced treatment-related AEs than ruxolitinib monotherapy. Treatment-related AEs and dose modification affect the safety and tolerability of ruxolitinib-based combinations. Genetic testing before treatment is recommended. To provide better clinical guidance, comparisons of these randomized controlled trials with the trials of ruxolitinib alone are necessary. This review suggests that the clinical application of ruxolitinib-based combinations is worth waiting for.

Macrocyclic prolinyl acyl guanidines as inhibitors of ß-secretase (BACE).

The synthesis, evaluation, and structure-activity relationships of a class of acyl guanidines which inhibit the BACE-1 enzyme are presented. The prolinyl acyl guanidine chemotype (7c), unlike compounds of the parent isothiazole chemotype (1), yielded compounds with good agreement between their enzymatic and cellular potency as well as a reduced susceptibility to P-gp efflux. Further improvements in potency and P-gp ratio were realized via a macrocyclization strategy. The in vivo profile in wild-type mice and P-gp effects for the macrocyclic analog 21c is presented.

Inhibition of influenza virus replication via small molecules that induce the formation of higher-order nucleoprotein oligomers.

Influenza nucleoprotein (NP) plays multiple roles in the virus life cycle, including an essential function in viral replication as an integral component of the ribonucleoprotein complex, associating with viral RNA and polymerase within the viral core. The multifunctional nature of NP makes it an attractive target for antiviral intervention, and inhibitors targeting this protein have recently been reported. In a parallel effort, we discovered a structurally similar series of influenza replication inhibitors and show that they interfere with NP-dependent processes via formation of higher-order NP oligomers. Support for this unique mechanism is provided by site-directed mutagenesis studies, biophysical characterization of the oligomeric ligand:NP complex, and an X-ray cocrystal structure of an NP dimer of trimers (or hexamer) comprising three NP_A:NP_B dimeric subunits. Each NP_A:NP_B dimeric subunit contains two ligands that bridge two composite, protein-spanning binding sites in an antiparallel orientation to form a stable quaternary complex. Optimization of the initial screening hit produced an analog that protects mice from influenza-induced weight loss and mortality by reducing viral titers to undetectable levels throughout the course of treatment.

The Protective Effects of Ganoderma lucidum Active Peptide GLP4 on Lung Injury Induced by Cadmium Poisoning in Mice.

Ganoderma triterpenes and spore powder have shown promising results in mitigating cadmium-induced renal and hepatic injuries. Ganoderma lucidum active peptide GLP4 is a natural protein with dual antioxidant activities derived from the mycelium of Ganoderma lucidum. However, its efficacy in alleviating cadmium-induced lung injury remains unexplored. This study aims to investigate the protective effects of GLP4 against cadmium-induced lung injury in mice. Mice were exposed to cadmium chloride via nebulization to induce lung injury. The protective effect of GLP4 was assessed by measuring the total cell count in BALF, levels of inflammatory cytokines, and the expression of NLRP3 in lung tissues a through histopathological examination of lung tissue changes. The results showed that GLP4 significantly mitigated histopathological damage in lung tissues, decreased the secretion of inflammatory cytokines, and reduced the expression of NLRP3, which was elevated in cadmium-exposed mice. In vitro studies further revealed that GLP4 inhibited the cadmium-induced activation of the NLRP3 inflammasome. Notably, acute cadmium exposure by the respiratory tract did not affect the liver and kidneys of the mice. The findings suggest that GLP4 reduces cadmium-induced lung injury in mice by inhibiting the activation of the NLRP3 inflammasome, which provides a theoretical foundation for using Ganoderma lucidum as a preventive and therapeutic agent against cadmium poisoning.

Isolation, structural elucidation and biosynthetic pathway of bioactive prenyl quinone compounds from Panus lecomtei based on untargeted metabolomics combined with molecular networking.

Panus lecomtei is a relatively unfamiliar and undeveloped mushroom. This study generated ethyl acetate extracts of P. lecomtei intracellular (I), extracellular (E) and total fermentation broth (T). Both E and T extracts demonstrated antioxidant and antibacterial activities at 100 to 200 µg/mL. The composition differences of metabolites of these extracts were further studied based on comparative metabolomics by LS/MS and molecular network analysis. The results revealed that there were over 2000 significantly distinct metabolites among the three extracts, with abundant prenyl quinone compounds. Furthermore, the molecular network clarified the conversion relationship of P. lecomtei metabolites. Seven known prenyl quinone derivatives (1-7) were isolated from the E extract. Among them, compound 3 displayed excellent antioxidant activity and modest antibacterial activity. Compound 5 was discovered in fungi for the first time. Finally, a potential biosynthetic route for prenyl quinone in P. lecomtei was suggested.

Experimental determination of surface energy for high-energy surface: A review.

The experimental determination of surface free energy is of great importance for engineering applications. However, there is no universal, reliable, and convenient measurement means to achieve experimental determination of solid surface energy for high-energy surface. In this work, the existing techniques for experimental determination of surface energy of solids, including indirect (4 kinds) and direct methods (3 kinds), were critically reviewed. In the indirect methods: the explicit interfacial bonding characteristics are required for the multiphase equilibrium technique and for the determination method from crystal equilibrium shape; the critical surface energy technique does not satisfy Zisman's hypothesis that the solid-liquid interface tension is zero (or close to zero), and the parameters fitted by empirical equations cannot have definite physical meaning; the derivation based on the surface tension in the liquid state can only obtain the surface energy of the solid phase near the melting point, and is limited to the prediction of the surface energy of elemental metal. Among the direct determination methods, except for the zero-creep method, are based on generalized determination technologies. All determined results are strongly influenced by the accuracy of the particle (grain) size, scale effect, the atmosphere, etc. This leads to the fact that the errors are still huge regardless of the determination method used, and it is difficult to achieve uniformity of the data. All methods rely to some extent on specific assumptions or theoretical models.

Activin Receptor-Like Kinase 3 Directly Couples Gαq (Guanine Nucleotide-Binding Protein Subunit αq)/ Gαq (Guanine Nucleotide-Binding Protein Subunit α11) to Regulate Vascular Contractility.

BACKGROUND: Vascular smooth muscle cell (VSMC) contractility is critical for blood pressure regulation and vascular homeostasis. Identifying the key molecule that maintains VSMC contractility may provide a novel therapeutic target for vascular remodeling. ALK3 (activin receptor-like kinase 3) is a serine/threonine kinase receptor, and deletion of ALK3 causes embryonic lethality. However, little is known about the role of ALK3 in postnatal arterial function and homeostasis. METHODS: We conducted in vivo studies in a tamoxifen-induced postnatal VSMC-specific ALK3 deletion mice suitable for analysis of blood pressure and vascular contractility. Additionally, the role of ALK3 on VSMC was determined using Western blot, collagen-based contraction assay and traction force microscopy. Furthermore, interactome analysis were performed to identify the ALK3-associated proteins and bioluminescence resonance energy transfer assay was used to characterize Gαq activation. RESULTS: ALK3 deficiency in VSMC led to spontaneous hypotension and impaired response to angiotensin II in mice. In vivo and in vitro data revealed that ALK3 deficiency impaired contraction force generation by VSMCs, repressed the expression of contractile proteins, and inhibited the phosphorylation of myosin light chain. Mechanistically, Smad1/5/8 signaling mediated the ALK3-modulated contractile protein expressions but not myosin light chain phosphorylation. Furthermore, interactome analysis revealed that ALK3 directly interacted with and activated Gαq (guanine nucleotide-binding protein subunit αq)/Gα11 (guanine nucleotide-binding protein subunit α11), thereby stimulating myosin light chain phosphorylation and VSMC contraction. CONCLUSIONS: Our study revealed that in addition to canonical Smad1/5/8 signaling, ALK3 modulates VSMC contractility through direct interaction with Gαq/Gα11, and therefore, might serve as a potential target for modulating aortic wall homeostasis.

Targeting cytokine-like protein FAM3D lowers blood pressure in hypertension.

Current antihypertensive options still incompletely control blood pressure, suggesting the existence of uncovered pathogenic mechanisms. Here, whether cytokine-like protein family with sequence similarity 3, member D (FAM3D) is involved in hypertension etiology is evaluated. A case-control study exhibits that FAM3D is elevated in patients with hypertension, with a positive association with odds of hypertension. FAM3D deficiency significantly ameliorates angiotensin II (AngII)-induced hypertension in mice. Mechanistically, FAM3D directly causes endothelial nitric oxide synthase (eNOS) uncoupling and impairs endothelium-dependent vasorelaxation, whereas 2,4-diamino-6-hydroxypyrimidine to induce eNOS uncoupling abolishes the protective effect of FAM3D deficiency against AngII-induced hypertension. Furthermore, antagonism of formyl peptide receptor 1 (FPR1) and FPR2 or the suppression of oxidative stress blunts FAM3D-induced eNOS uncoupling. Translationally, targeting endothelial FAM3D by adeno-associated virus or intraperitoneal injection of FAM3D-neutralizing antibodies markedly ameliorates AngII- or deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Conclusively, FAM3D causes eNOS uncoupling through FPR1- and FPR2-mediated oxidative stress, thereby exacerbating the development of hypertension. FAM3D may be a potential therapeutic target for hypertension.

Alkaline ceramidase 1-mediated platelet ceramide catabolism mitigates vascular inflammation and abdominal aortic aneurysm formation.

Abdominal aortic aneurysm (AAA) is a highly lethal vascular disease. The role of platelets in AAA remains incompletely understood. Here we show that platelet ceramides, rather than other phospholipids, were elevated in an angiotensin II (AngII)-induced AAA murine model and in patients with AAA by using targeted lipidomic analysis. Among key ceramide metabolism enzymes, alkaline ceramidase 1 (Acer1) hydrolyzing ceramides were exclusively downregulated in AAA platelets. Platelet-specific Acer1 knockout mice were more susceptible to AAA upon AngII infusion without affecting hemostasis and thrombosis. Mechanistically, Acer1 deficiency in platelets facilitated platelet pro-inflammatory cytokine secretion as well as P-selectin-mediated circulating platelet-leukocyte aggregation and infiltration in aortic walls via the ceramide-p38 MAPK signaling axis. Of note, AngII repressed Acer1 expression in platelets by decreasing HuR-dependent mRNA stability. In conclusion, Acer1-mediated ceramide degradation in platelets exhibited anti-inflammatory effects and ameliorated AAA formation, potentially serving as a therapeutic target for AAA and other inflammatory vascular diseases.

[Clinical Characteristics of Patients with JAK2 Gene Mutation Myeloproliferative Neoplasms].

OBJECTIVE: To investigate the relationship between JAK2 gene mutation and clinical indicators in patients with myeloproliferative neoplasms (MPN). METHODS: 122 MPN patients in the Department of Hematology, Xiyuan Hospital, China Academy of Chinese Medical Sciences from September 2017 to January 2020 were retrospectively analyzed. The relationship between JAK2 gene mutation and sex, age, peripheral blood cell count, splenomegaly, and thrombosis and bleeding events were analyzed. RESULTS: In 122 patients with MPN, the patients with polycythemia vera (PV) accounted for 36 (29.5%), the patients with essential thrombocythemia (ET) accounted for 56 (45.9%), the patients with myelofibrosis (MF) accounted for 30 (24.6%). The JAK2 gene mutation rate in MPN patients was 64.6% (79/122), and the JAK2 gene mutation rate in PV, ET and MF groups were 77.7% (28/36), 60.7% (34/56) and 56.7% (17/30), the JAK2 gene mutation rate of the patients in PV group was statistically significant as compared with those in the ET group (P＜0.05). The hemoglobin (Hb) count of the patients in JAK2 gene mutation group was higher than those in wild-type group ï¼»(150.0±39.6)g/L vs (129.4±38.9)g/L, P＜0.05ï¼½; the white blood cell (WBC) count of the patients in JAK2 gene mutation group was higher than those in the wild type group ï¼»(9.5±4.7)×109/L vs (8.4±46.9)×109/L, P＜0.05ï¼½. As for the patients in PV group, the platelet count of the patients in JAK2 gene mutation group was higher than those in the wild type group ï¼»(370.2±113.1)×109/L vs (264.8±63.9)×109/L, P＜0.05ï¼½. The incidence of splenomegaly in MPN patients was 35.2% (43/122), and the incidence of splenomegaly in MF patients was 63.3% (19/30), and the incidence of splenomegaly in the patients in JAK2 gene mutation group in MF group (82.4%, 12/17) was significantly higher than those in the wild-type group (38.5%, 5/13) (P<0.05). CONCLUSION: The mutation rate of JAK2 gene in MPN patients is higher, and the mutation rate of JAK2 gene in PV patients is higher than that in ET and MF patients; JAK2 gene mutations in MPN patients are related to hemogram index; the incidence of splenomegaly is the highest in MF patients, and splenomegaly is related to the occurrence of JAK2 gene mutations in MF patients.

Predicting bleeding risk in a Chinese immune thrombocytopenia (ITP) population: development and assessment of a new predictive nomogram.

The aim of this study was to develop a model that could be used to forecast the bleeding risk of ITP based on proinflammatory and anti-inflammatory factors. One hundred ITP patients were recruited to build a new predictive nomogram, another eighty-eight ITP patients were enrolled as validation cohort, and data were collected from January 2016 to January 2019. Four demographic characteristics and fifteen clinical characteristics were taken into account. Eleven cytokines (IFN-γ, IL-1, IL-4, IL-6, IL-8, IL-10, IL-17A, IL-22, IL-23, TNF-α and TGF-ß) were used to study and the levels of them were detected by using a cytometric bead array (CBA) human inflammation kit. The least absolute shrinkage and selection operator regression model was used to optimize feature selection. Multivariate logistic regression analysis was applied to build a new predictive nomogram based on the results of the least absolute shrinkage and selection operator regress ion model. The application of C-index, ROC curve, calibration plot, and decision curve analyses were used to assess the discrimination, calibration, and clinical practicability of the predictive model. Bootstrapping validation was used for testing and verifying the predictive model. After feature selection, cytokines IL-1, IL-6, IL-8, IL-23 and TGF-ß were excluded, cytokines IFN-γ, IL-4, IL-10, IL-17A, IL-22, TGF-ß, the count of PLT and the length of time of ITP were used as predictive factors in the predictive nomogram. The model showed good discrimination with a C-index of 0.82 (95% confidence interval 0.73376-0.90 624) in training cohortn and 0.89 (95% CI 0.868, 0.902) in validation cohort, an AUC of 0.795 in training cohort, 0.94 in validation cohort and good calibration. A high C-index value of 0.66 was reached in the interval validation assessment. Decision curve analysis showed that the bleeding risk nomogram was clinically useful when intervention was decided at the possibility threshold of 16-84%. The bleeding risk model based on IFN-γ, IL-4, IL-10, IL-17A, IL-22, TGF-ß, the count of PLT and the length of time of ITP could be conveniently used to predict the bleeding risk of ITP.

Solid-phase synthesis of a library based on biphenyl-containing trypsin-like serine protease inhibitors.

The solid-phase synthesis of a library based on an unusual biphenyl-containing trypsin-like serine protease inhibitor is described. Key to this effort was the synthesis of a highly functionalized aryl boronic acid reagent which required the development of a novel and efficient method to convert a triflate to a pinacolboronate in large scale.

Elucidation of the Mechanisms and Molecular Targets of Yiqi Shexue Formula for Treatment of Primary Immune Thrombocytopenia Based on Network Pharmacology.

Yiqi Shexue formula (YQSX) is traditionally used to treat primary immune thrombocytopenia (ITP) in clinical practice of traditional Chinese medicine. However, its mechanisms of action and molecular targets for treatment of ITP are not clear. The active compounds of YQSX were collected and their targets were identified. ITP-related targets were obtained by analyzing the differential expressed genes between ITP patients and healthy individuals. Protein-protein interaction (PPI) data were then obtained and PPI networks of YQSX putative targets and ITP-related targets were visualized and merged to identify the candidate targets for YQSX against ITP. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis were carried out. The gene-pathway network was constructed to screen the key target genes. In total, 177 active compounds and 251 targets of YQSX were identified. Two hundred and thirty differential expressed genes with an P value < 0.005 and |log2(fold change)| > 1 were identified between ITP patient and control groups. One hundred and eighty-three target genes associated with ITP were finally identified. The functional annotations of target genes were found to be related to transcription, cytosol, protein binding, and so on. Twenty-four pathways including cell cycle, estrogen signaling pathway, and MAPK signaling pathway were significantly enriched. MDM2 was the core gene and other several genes including TP53, MAPK1, CDKN1A, MYC, and DDX5 were the key gens in the gene-pathway network of YQSX for treatment of ITP. The results indicated that YQSX's effects against ITP may relate to regulation of immunological function through the specific biological processes and the related pathways. This study demonstrates the application of network pharmacology in evaluating mechanisms of action and molecular targets of complex herbal formulations.

[Level of Regulatory B Cells in Patients with Immune Thrombocytopenia and Its Clinical Significance].

OBJECTIVE: To investigate the role of regulatory B cells (Breg) in pathogenesis of immune thrombocytopenia(ITP) and its clinical significance. METHODS: A total of 40 ITP patients and 20 normal controls were enrolled in this study. The content of Breg, Th1, Th2, Th17 and Treg cells were detected by flow cytometry (FCM). The expression level of IL-10,TGF-ß, CD40 and CD40L was detected by AimPlex Flow High Throughput Screening Technology. RESULTS: The of Breg cells in ITP patients was significantly lower than that in normal controls (P<0.05)，the expression levels of IL-10,TGF-ß and CD40L in ITP patients were also significantly lower than those in normal controls (P<0.05). The contents of Th1 cells in ITP patients were significantly higher than that in normal controls (P<0.05), whereas the contents of Th2, Th17 and Treg cells in ITP patients were significantly lower than those in normal controls (P<0.05). CONCLUSION: The Breg cells may play an important role in the pathogenesis of ITP.

Relation of Blood Arsenic Concentration with Effect and Safety of Arsenic-Containing Qinghuang Powder () in Patients with Myelodysplastic Syndrome.

OBJECTIVE: To investigate the relation of blood arsenic concentration (BAC) with clinical effect and safety of arsenic-containing Qinghuang Powder (, QHP) in patients with myelodysplastic syndrome (MDS). METHODS: Totally 163 patients with MDS were orally treated with QHP for 2 courses of treatment, 3 months as 1 course. The BACs of patients were detected by atomic fluorescence spectrophotometry at 1, 3, and 6 months during the treatment, and the effective rate, hematological improvement and safety in patients after treatment with QHP were analyzed. RESULTS: After 2 courses of treatment, the total effective rate was 89.6% (146/163), with 31.3% (51/163) of hematological improvement and 58.3% (95/163) of stable disease. The hemoglobin increased from 73.48 ± 19.30 g/L to 80.39 ± 26.56 g/L (P<0.05), the absolute neutrophil count increased from 0.81 ± 0.48 × 109/L to 1.08 ± 0.62 × 109/L (P<0.05), and no significant changes were observed in platelet counts (P>0.05). Among 46 patients previously depended on blood transfusion, 28.3% (13/46) completely got rid of blood transfusion and 21.7% (10/46) reduced the volume of blood transfusion by more than 50% after treatment. The BACs were significantly increased in patients treated for 1 month with 32.17 ± 18.04 µ g/L (P<0.05), 3 months with 33.56 ± 15.28 µ g/L (P<0.05), and 6 months with 36.78 ± 11.92 µ g/L (P<0.05), respectively, as compared with those before treatment (4.08 ± 2.11 µ g/L). There were no significant differences of BACs among the patients treated for 1, 3 and 6 months (P>0.05). The adverse reactions of digestive tract during the treatment were mild abdominal pain and diarrhea in 14 cases (8.6%), and no patients discontinued the treatment. The BACs of patients with gastrointestinal adverse reactions were significantly lower than those without gastrointestinal adverse reactions (22.39 ± 10.38 vs. 37.89 ± 11.84, µ g/L, P<0.05). The BACs of patients with clinical effect were significantly higher than those failed to treatment (40.41 ± 11.69 vs. 23.84 ± 12.03, µ g/L, P<0.05). CONCLUSION: QHP was effective and safe in the treatment of patients with MDS and the effect was associated with BACs of patients.

[Secretory Imbalance between Pro-inflammatory and Anti-inflammatory Cytokines in the Patients with Immune Thrombocytopenia].

OBJECTIVE: To analyze the imbalance of pro-inflammatory and anti-inflammatory cytokines in the patients of immune thrombocytopenia (ITP). METHODS: Thirty-five patients with ITP were enrolled in ITP group, while 28 healthy persons were included in control group. The expressions of IL-8, IL-17A, IL-22, TNF-α, IFN-γ, IL-4, CD40, CD40L, TGF-ß and IL-10 were detected by flow cytometry with aimPlex multiple immunoassay Flow. RESULTS: The expressions of pro-inflammatory factors IL-8, IL-17A, IL-22, IFN-γ and TNF-α in ITP group all were significantly higher than that in the control group (P<0.05), however the expressions of anti-inflammatory factors IL-4, CD40L, TGF-ß and IL-10 in ITP group all were significantly lower than that in the control group (P<0.05). The expression of CD40 was not significantly different between ITP group and control group (P>0.05). Expressions of TNF-α significantly related with platelet counts in both ITP group and control group (ITP group, r=0.64, P<0.05; control group, r=-0.41, P<0.05). However the expression of CD40, TGF-ß, CD40L, IL-8, IL-17A, IL-22, IL-10, IL-1ß, IFN-γ and IL-4 significantly did not relate with platelet counts in both ITP and control group. CONCLUSIONS: The secretory imbalance between pro-inflammatory and anti-inflammatory cytokines exists in the patients of ITP. The decrease of Plt regulated may be regulated by the abnormal expression of TNF-α.

Study on the Clinical Safe and Effective Methods of Arsenic-Containing Compound-Qinghuang Powder in the Treatment of Myelodysplastic Syndrome.

OBJECTIVE: To establish the clinical safe and effective methods of arsenic-containing compound-Qinghuang Powder (compound-QHP) in the treatment of myelodysplastic syndrome (MDS). METHODS: 200 patients with MDS were treated with compound-QHP (daily dose of 0.1 g realgar). The blood arsenic concentrations (BACs) were detected by atomic fluorescence spectrophotometry (HF-AFS). After treatment for 1 month, the patients were randomly divided into group A and group B when the BACs were less than 20 µg/L. Daily dose of realgar was maintained in group A and it was increased to that when the BACs were more than 20 µg/L in group B. The BAC and clinical efficacy and safety in two groups were compared at the end of the treatment with compound-QHP. RESULTS: The average BAC of group B was significantly higher than that of group A (P < 0.01). The rates of hematology improvement and reduced transfusion were significantly higher in group B than in group A (P < 0.05). The HGB, ANC, and PLT significantly increased in group B after treatment (P > 0.05). CONCLUSIONS: Monitoring the BAC and adjusting the daily dose of realgar to increase the effective BAC and then improving efficacy without increasing the clinical toxicity are the clinical safe and effective methods in the treatment of MDS.

Acyl guanidine inhibitors of ß-secretase (BACE-1): optimization of a micromolar hit to a nanomolar lead via iterative solid- and solution-phase library synthesis.

This report describes the discovery and optimization of a BACE-1 inhibitor series containing an unusual acyl guanidine chemotype that was originally synthesized as part of a 6041-membered solid-phase library. The synthesis of multiple follow-up solid- and solution-phase libraries facilitated the optimization of the original micromolar hit into a single-digit nanomolar BACE-1 inhibitor in both radioligand binding and cell-based functional assay formats. The X-ray structure of representative inhibitors bound to BACE-1 revealed a number of key ligand:protein interactions, including a hydrogen bond between the side chain amide of flap residue Gln73 and the acyl guanidine carbonyl group, and a cation-π interaction between Arg235 and the isothiazole 4-methoxyphenyl substituent. Following subcutaneous administration in rats, an acyl guanidine inhibitor with single-digit nanomolar activity in cells afforded good plasma exposures and a dose-dependent reduction in plasma Aß levels, but poor brain exposure was observed (likely due to Pgp-mediated efflux), and significant reductions in brain Aß levels were not obtained.

Small molecule receptor protein tyrosine phosphatase γ (RPTPγ) ligands that inhibit phosphatase activity via perturbation of the tryptophan-proline-aspartate (WPD) loop.

Protein tyrosine phosphatases (PTPs) catalyze the dephosphorylation of tyrosine residues, a process that involves a conserved tryptophan-proline-aspartate (WPD) loop in catalysis. In previously determined structures of PTPs, the WPD-loop has been observed in either an "open" conformation or a "closed" conformation. In the current work, X-ray structures of the catalytic domain of receptor-like protein tyrosine phosphatase γ (RPTPγ) revealed a ligand-induced "superopen" conformation not previously reported for PTPs. In the superopen conformation, the ligand acts as an apparent competitive inhibitor and binds in a small hydrophobic pocket adjacent to, but distinct from, the active site. In the open and closed WPD-loop conformations of RPTPγ, the side chain of Trp1026 partially occupies this pocket. In the superopen conformation, Trp1026 is displaced allowing a 3,4-dichlorobenzyl substituent to occupy this site. The bound ligand prevents closure of the WPD-loop over the active site and disrupts the catalytic cycle of the enzyme.

Solid-phase synthesis and anti-infective activity of a combinatorial library based on the natural product anisomycin.

The solid-phase synthesis of a library based on the natural product anisomycin is described. The resulting library was tested against a panel of bacterial and fungal targets, and active compounds were identified in a Staphylococcus aureus whole-cell assay and an efflux-deficient fungal whole-cell assay.