Self-Supported Defect-Rich Au-Based Nanostructures as Robust Bifunctional Catalysts for the Methanol Oxidation Reaction and Oxygen Reduction Reaction in an Alkaline Medium.

Recently, alkaline direct methanol fuel cells have made great progress with the development of alkaline electrocatalysis, and a wide variety of catalysts have been explored for methanol oxidation reaction (MOR)and oxygen reduction reaction (ORR). However, the slow kinetics of the MOR and ORR remain a great challenge. In this paper, self-supported defect-rich AuCu was obtained by a convenient one-pot strategy. Self-supported AuCu presented a branched, porous nanostructure. The nanobranch consisted of several 13 nm skeletons, which connected in the kink of the structure. Different growth directions co-existed at the kink, and the twin boundaries and dislocations as defects were observed. When the Au-based nanostructure functioned as an electrocatalyst, it showed robust MOR and ORR performance. For the MOR, the forward peak current was 2.68 times greater than that of Au/C; for the ORR, the activity was close to that of Pt/C and significantly better than that of Au/C. In addition, it possessed superior electrochemical stability for MOR and ORR. Finally, an in-depth exploration of the impact of surface defects and electrochemical Cu removal on MOR and ORR activity was carried out to explain the MOR and ORR's catalytic performance.

Transplantation efficacy of autologous bone marrow mesenchymal stem cells combined with atorvastatin for acute myocardial infarction (TEAM-AMI): rationale and design of a randomized, double-blind, placebo-controlled, multi-center, Phase II TEAM-AMI trial.

Aim: To determine the efficacy and safety of intracoronary infusion of autologous bone marrow mesenchymal stem cells (MSCINJ) in combination with intensive atorvastatin (ATV) treatment for patients with anterior ST-segment elevation myocardial infarction-elevation myocardial infarction. Patients & methods: The trial enrolls a total of 100 patients with anterior ST-elevation myocardial infarction. The subjects are randomly assigned (1:1:1:1) to receive routine ATV (20 mg/d) with placebo or MSCsINJ and intensive ATV (80 mg/d) with placebo or MSCsINJ. The primary end point is the absolute change of left ventricular ejection fraction within 12 months. The secondary end points include parameters in cardiac function, remodeling and regeneration, quality of life, biomarkers and clinical outcomes. Results & conclusion: The trial will implicate the essential of cardiac micro-environment improvement ('fertilizing') for cell-based therapy. Clinical Trial Registration: NCT03047772.

A novel bispecific peptide HIV-1 fusion inhibitor targeting the N-terminal heptad repeat and fusion peptide domains in gp41.

HIV-1 fusion with the target cell is initiated by the insertion of the gp41 fusion peptide (FP) into the target cell membrane and the interaction between the gp41 N- and C-terminal heptad repeats (NHR and CHR), followed by the formation of the six-helix bundle (6-HB) fusion core. Therefore, both FP and NHR are important targets for HIV-1 fusion inhibitors. Here, we designed and synthesized a dual-target peptidic HIV-1 fusion inhibitor, 4HR-LBD-VIRIP, in which 4HR-LBD is able to bind to the gp41 NHR domain, while VIRIP is able to interact with gp41 FP. We found that 4HR-LBD-VIRIP is about tenfold more potent than 4HR-LBD and VIRIP in inhibiting HIV-1IIIB infection and HIV-1 envelope glycoprotein (Env)-mediated cell-cell fusion, suggesting that this dual-target HIV-1 fusion inhibitor possesses a strong synergistic antiviral effect. A biophysical analysis indicates that 4HR-LBD-VIRIP can interact with N70 peptide that contains the gp41 NHR and FP domains and binds with lipid membrane. This study provides a new approach for designing novel viral fusion inhibitors against HIV and other enveloped viruses with class I membrane fusion proteins.

Site-specific Isopeptide Bridge Tethering of Chimeric gp41 N-terminal Heptad Repeat Helical Trimers for the Treatment of HIV-1 Infection.

Peptides derived from the N-terminal heptad repeat (NHR) of HIV-1 gp41 can be potent inhibitors against viral entry when presented in a nonaggregating trimeric coiled-coil conformation via the introduction of exogenous trimerization motifs and intermolecular disulfide bonds. We recently discovered that crosslinking isopeptide bridges within the de novo helical trimers added exceptional resistance to unfolding. Herein, we attempted to optimize (CCIZN17)3, a representative disulfide bond-stabilized chimeric NHR-trimer, by incorporating site-specific interhelical isopeptide bonds as the redox-sensitive disulfide surrogate. In this process, we systematically examined the effect of isopeptide bond position and molecular sizes of auxiliary trimeric coiled-coil motif and NHR fragments on the antiviral potency of these NHR-trimers. Pleasingly, (IZ14N24N)3 possessed promising inhibitory activity against HIV-1 infection and markedly increased proteolytic stability relative to its disulfide-tethered counterpart, suggesting good potential for further development as an effective antiviral agent for treatment of HIV-1 infection.

An effective conjugation strategy for designing short peptide-based HIV-1 fusion inhibitors.

Lengthy peptides corresponding to the C-terminal heptad repeat (C-peptides) of human immunodeficiency virus type 1 (HIV-1) gp41 are potent inhibitors against virus-cell fusion. Designing short C-peptide-based HIV-1 fusion inhibitors could potentially redress the physicochemical and technical liabilities of a long-peptide therapeutic. However, designing such inhibitors with high potency has been challenging. We generated a conjugated architecture by incorporating small-molecule inhibitors of gp41 into the N-terminus of a panel of truncated C-peptides. Among these small molecule-capped short peptides, the 26-residue peptide Indole-T26 inhibited HIV-1 Env-mediated cell-cell fusion and viral replication at low nanomolar levels, reaching the potency of the only clinically used 36-residue peptide T20 (enfuvirtide). Collectively, our work opens up a new avenue for developing short peptide-based HIV-1 fusion inhibitors, and may have broad applicability to the development of modulators of other class I fusion proteins.

Design, synthesis, and evaluation of water-soluble morpholino-decorated paclitaxel prodrugs with remarkably decreased toxicity.

Novel water-soluble paclitaxel prodrugs were designed and synthesized by introducing morpholino groups through different linkers. These derivatives showed 400-20,000-times greater water solubility than paclitaxel as well as comparable activity in MCF-7 and HeLa cell lines. The prodrug PM4 was tested in the S-180 tumor mouse model, with paclitaxel as the positive control. The results showed that PM4 had comparable antitumor activity as paclitaxel, with tumor inhibition of 54% versus 56%, and remarkably decreased toxicity. The survival rate of treated mice was 8/8 in the PM4 group, compared to 3/8 in the paclitaxel group.

An effective strategy for recapitulating N-terminal heptad repeat trimers in enveloped virus surface glycoproteins for therapeutic applications.

Sequestering peptides derived from the N-terminal heptad repeat (NHR) of class I viral fusion proteins into a non-aggregating trimeric coiled-coil conformation remains a major challenge. Here, we implemented a synthetic strategy to stabilize NHR-helical trimers, with the human immunodeficiency virus type 1 (HIV-1) gp41 fusion protein as the initial focus. A set of trimeric scaffolds was realized in a synthetic gp41 NHR-derived peptide sequence by relying on the tractability of coiled-coil structures and an additional isopeptide bridge-tethering strategy. Among them, (N36M)3 folded as a highly stable helical trimer and exhibited promising inhibitory activity against HIV-1 infection, exceptional resistance to proteolysis, and effective native ligand-binding capability. We anticipate that the trimeric coiled-coil recapitulation methodology described herein may have broader applicability to yield NHR trimers of other class I enveloped viruses and to prepare helical tertiary structure mimetics of certain natural protein-protein interactions for biomedical applications.

DNA Triplex-Based Complexes Display Anti-HIV-1-Cell Fusion Activity.

DNA triplexes with hydrophobic modifications were designed and evaluated for their activity as inhibitors of the cell fusion of human immunodeficiency virus type 1 (HIV-1). Triplex inhibitors displayed low micromolar activities in the cell-cell fusion assay and nanomolar activities in the anti-HIV-1 pseudovirus test. Helix structure and the presence of sufficient numbers of hydrophobic regions were essential for the antifusion activity. Results from native polyacrylamide gel electrophoresis and a fluorescent resonance energy transfer-based inhibitory assay indicated that these triplexes may interact with the primary pocket at the glycoprotein 41 (gp41) N-heptad repeat, thereby inhibiting formation of the HIV-1 gp41 6-helical bundle. Triplex-based complexes may represent a novel category of HIV-1 inhibitors in anti-HIV-1 drug discovery.

De novo design of isopeptide bond-tethered triple-stranded coiled coils with exceptional resistance to unfolding and proteolysis: implication for developing antiviral therapeutics.

Isopeptide bond-tethered triple-stranded coiled coils of HIV-1 gp41 N-terminal heptad repeat (NHR) peptides have been designed with de novo auxiliaries to guide site-directed trimerized cross-linking. The presence of isopeptide bridges in the rationally designed trimerization motifs provides extraordinary stability to withstand thermal and chemical denaturation. As a result, these ultra-stable and well-folded trimeric coiled coils direct and yield proteolysis-resistant and remarkably potent N-peptide chimeric trimers with HIV-1 fusion inhibitory activities in the low nanomolar range, much more effective than the corresponding unstructured N-peptide monomers and reaching the potency of clinically used T20 peptide (enfuvirtide). Thus, these isopeptide bond-crosslinked de novo coiled coils may also be used as attractive scaffolds for isolating NHR-trimers in other class I enveloped viruses for therapeutic intervention. Furthermore, this isopeptide bridge-tethering strategy could be extendable to the construction of ultra-stable proteins interfering with certain biological processes.

Conjugation of a nonspecific antiviral sapogenin with a specific HIV fusion inhibitor: a promising strategy for discovering new antiviral therapeutics.

Triterpene saponins are a major group of active components in natural products with nonspecific antiviral activities, while T20 peptide (enfuvirtide), which contains a helix zone-binding domain (HBD), is a gp41-specific HIV-1 fusion inhibitor. In this paper, we report the design, synthesis, and structure-activity relationship (SAR) of a group of hybrid molecules in which bioactive triterpene sapogenins were covalently attached to the HBD-containing peptides via click chemistry. We found that either the triterpenes or peptide part alone showed weak activity against HIV-1 Env-mediated cell-cell fusion, while the hybrids generated a strong cooperative effect. Among them, P26-BApc exhibited anti-HIV-1 activity against both T20-sensitive and -resistant HIV-1 strains and improved pharmacokinetic properties. These results suggest that this scaffold design is a promising strategy for developing new HIV-1 fusion inhibitors and possibly novel antiviral therapeutics against other viruses with class I fusion proteins.

The use of hairpin DNA duplexes as HIV-1 fusion inhibitors: synthesis, characterization, and activity evaluation.

Discovery of new drugs for the treatment of AIDS that possess unique structures associated with novel mechanisms of action are of great importance due the rapidity with which drug-resistant HIV-1 strains evolve. Recently we reported on a novel class of DNA duplex-based HIV-1 fusion inhibitors modified with hydrophobic groups. The present study describes a new category of hairpin fusion inhibitor DNA duplexes bearing a 3 nucleotide loop located at either the hydrophobic or hydrophilic end. The new loop structures were designed to link 2 separate duplex-forming oligodeoxynucleotides (ODNs) to make helix-assembly easier and more thermally stable resulting in a more compact form of DNA duplex based HIV-1 fusion inhibitors. A series of new hairpin duplexes were tested for anti-HIV-1 cell-cell membrane fusion activity. In addition, Tm, CD, fluorescent resonance energy transfer assays, and molecular modeling analyses were carried out to define their structural activity relationships and possible mechanisms of action.

Artificial peptides conjugated with cholesterol and pocket-specific small molecules potently inhibit infection by laboratory-adapted and primary HIV-1 isolates and enfuvirtide-resistant HIV-1 strains.

OBJECTIVES: To develop new HIV-1 fusion inhibitors with improved antiviral activities and resistance profiles, we designed two categories of artificial peptides, each containing four heptad repeats (m4HR) conjugated with a pocket-specific small molecule (pssm) or pssm and cholesterol (chol), designated pssm-m4HR or pssm-m4HR-chol, respectively, and tested their anti-HIV-1 activity. METHODS: We synthesized the artificial peptides and conjugated these peptides with pssm and chol using a standard solid-phase Fmoc protocol and a chemoselective thioether conjugation method, respectively. We tested the inhibitory activities of the peptide conjugates against HIV-1 Env-mediated cell-cell fusion and infection by laboratory-adapted and primary HIV-1 isolates, and enfuvirtide-resistant HIV-1 strains using cell-cell fusion and p24 production assays, respectively. We assessed their cytotoxicity towards MT-2 cells using the XTT assay. RESULTS: We found that pssm-m4HR conjugates exhibited promising inhibitory activity against HIV-1 Env-mediated cell-cell fusion and laboratory-adapted HIV-1 replication with IC50 values at the low micromolar level, whereas the pssm-m4HR-chol conjugates exhibited dramatically increased anti-HIV-1 activities with IC50 values at the low nanomolar level. Some of the pssm-m4HR-chol conjugates (e.g. 5a and 5b) showed highly potent antiviral activity against infection by primary HIV-1 isolates and enfuvirtide-resistant HIV-1 strains. All the conjugates displayed no or low cytotoxicity towards MT-2 cells. The result of a prime/wash assay indicated pssm-m4HR-chol conjugates were strongly anchored to the membrane and sustained a potent inhibitory effect after washing. CONCLUSIONS: These results suggest this scaffold design is a promising strategy for developing novel peptide conjugates with improved antiviral activity against a broad spectrum of HIV-1 strains, including those highly resistant to enfuvirtide.

[Relationship of iron overload to bone mass density and bone turnover in postmenopausal women with fragility fractures of the hip].

OBJECTIVE: To study relationships between serum ferritin and bone metabolism in patients with hip fragility fractures. METHODS: This cross-sectional study included 76 postmenopausal women with hip fracture from Feburary 2011 to June 2012. The mean age of the women was (73 ± 10) years (range, 55-93 years) and the mean duration of menstruation was (22 ± 10)years (range, 5-50 years). Serum concentrations of ferritin, transferrin, alkaline phosphatase (ALP), amino-terminal extension peptide of type I collagen (P1NP), C-terminal telopeptides of type I collagen (ß-CTX)and femoral and lumbar bone mineral density by dual-energy X-ray absorptiometry were measured. Bone metabolism was compared between normal and elevated ferritin groups with t-test, Pearson linear, partial correlation and multiple regression analysis examined associations between iron- and bone-related markers. RESULTS: Serum ferritin concentration raised to (230 ± 146)µg/L, transferrin concentration reduced to (1.89 ± 0.33)g/L. P1NP concentration raised to (61 ± 32) ng/L when the concentration of serum ALP and ß-CTX were in the normal range. T-scores for bone mineral density in the femoral neck (-2.0 ± 1.1) and lumbar (-2.1 ± 1.2) were below the normal ranges(-1.0-1.0). The subjects were divided into two groups according to serum ferritin concentration, normal group(serum ferritin concentration ≤ 150 µg/L, n = 25) and elevated group(serum ferritin concentration > 150 µg/L, n = 51). Patients of elevated group had lower bone mineral density in femoral neck and lumbar than normal group(t = 3.13,2.89, P < 0.01), and higher P1NP, ß-CTX concentration (t = -2.38, -3.59, P < 0.05) . In partial correlation analysis adjusted for confounders, serum ferritin concentration was correlated negatively with bone mineral density in both femoral neck and lumbar (r = -0.335,-0.295, P < 0.05), and positively with P1NP and ß-CTX (r = 0.467,0.414, P < 0.05), but not correlated with ALP (r = 0.188, P > 0.05). Transferrin concentration tended to be correlated positively with bone mineral density in both femoral neck and lumbar (r = 0.444, 0.262, P < 0.05) and negatively with ALP, P1NP and ß-CTX(r = -0.326,-0.285,-0.278, P < 0.05). CONCLUSIONS: Iron overload has a high prevalence in postmenopausal women with fragility fracture. Increased iron stores, which might lead to bone loss and lower bone mineral density by enhancing the activity of bone turnover, could be an independent factor to take effects on bone metabolism on postmenopausal women.

Increase of anti-HIV activity of C-peptide fusion inhibitors using a bivalent drug design approach.

We reported the design of fusion inhibitors with improved activity using a multivalent inhibitor design strategy. First, we chose C29 as the template sequence, which is a 29-mer peptide derived from HIV-1 gp41 CHR domain and has anti-HIV activity of IC50 118 nM in a cell-cell fusion assay. We optimized the crosslink sites and linkers of the template peptide. We found that N-terminal crosslink caused activity improvement based on the multivalent co-operative effect. Especially, the IC50 of peptide (CAcaC29)2 was improved from 49.02 (monomeric form) to 5.71 nM. Compared with long peptides, short peptides may be more suitable to analyze the co-operative effect. So we selected a shorter peptide C22 to synthesize the bivalent inhibitors. Due its weak helicity, no co-operative effect appeared. Therefore, we chose SC22EK, which were introduced salt bridges to consolidate the helicity based on the natural sequence C22. The cross-linked (CAcaSC22EK)2 was four times more potent than the monomer SC22EK in anti-HIV activity, with an IC50 value of 4.92 nM close to the high active peptide fusion inhibitor C34. The strategy used in this study may be used to design new fusion inhibitors to interfere similar processes.

DNA duplexes with hydrophobic modifications inhibit fusion between HIV-1 and cell membranes.

Discovery of new drugs for the treatment of AIDS typically possessing unique structures associated with novel mechanisms of action has been of great importance due to the quick drug-resistant mutations of HIV-1 strains. The work presented in this report describes a novel class of DNA duplex-based HIV-1 fusion inhibitors. Hydrophobic groups were introduced into a DNA duplex skeleton either at one end, at both ends, or in the middle. These modified DNA duplexes inhibited fusion between HIV-1 and human cell membranes at micro- or submicromolar concentrations. Respective inhibitors adopted an aptamer pattern instead of a base-pairing interaction pattern. Structure-activity relationship studies of the respective DNA duplexes showed that the rigid and negatively charged DNA skeletons, in addition to the presence of hydrophobic groups, were crucial to the anti-HIV-1 activity of these compounds. A fluorescent resonance energy transfer (FRET)-based inhibitory assay showed that these duplex inhibitors interacted with the primary pocket in the gp41 N-terminal heptad repeat (NHR) instead of interacting with the lipid bilayers.

Design, synthesis, and biological evaluation of highly potent small molecule-peptide conjugates as new HIV-1 fusion inhibitors.

The small molecule fusion inhibitors N-(4-carboxy-3-hydroxyphenyl)-2,5-dimethylpyrrole (NB-2) and N-(3-carboxy-4-hydroxyphenyl)-2,5-dimethylpyrrole (A12) target a hydrophobic pocket of HIV-1 gp41 and have moderate anti-HIV-1 activity. In this paper, we report the design, synthesis, and structure-activity relationship of a group of hybrid molecules in which the pocket-binding domain segment of the C34 peptide was replaced with NB-2 and A12 derivatives. In addition, the synergistic effect between the small molecule and peptide moieties was analyzed, and lead compounds with a novel scaffold were discovered. We found that either the nonpeptide or peptide part alone showed weak activity against HIV-1-mediated cell-cell fusion, but the conjugates properly generated a strong synergistic effect. Among them, conjugates Aoc-ßAla-P26 and Noc-ßAla-P26 exhibited a low nanomolar IC50 in the cell-cell fusion assay and effectively inhibited T20-sensitive and -resistant HIV-1 strains. Furthermore, the new molecules exhibited better stability against proteinase K digestion than T20 and C34.

Design of highly potent HIV fusion inhibitors based on artificial peptide sequences.

Specific interactions were introduced between an artificial heptad repeat peptide template and HIV-1 gp41 for fusion inhibitor design, using a structure based rational design strategy. The designed peptides are nonhomologous with naturally occurring peptide and protein sequences, specifically interact with HIV-1 gp41, and show strong anti-HIV activity.

Short cyclic peptides derived from the C-terminal sequence of α1-antitrypsin exhibit significant anti-HIV-1 activity.

Serpin A1 (α1-AT), the largest subgroup of serpins, presents in human plasma at high concentration and plays important regulatory roles in physiological and pathological processes. Accumulated evidence suggests that α1-AT may play a role in controlling HIV-1 infection. In this study, we designed and synthesized a set of short linear peptides derived from the C-terminal sequence of α1-AT. Since none of them showed significant anti-HIV-1 activity, we proceeded to synthesize four short cyclic peptides having 7 amino acids, and we found that three of them exhibited significant anti-HIV-1 activity. One of these cyclic peptides, designated CPM, inhibited HIV-1 entry and infection at low µM level, indicating that these short cyclic peptides could serve as leads for the development of novel anti-HIV-1 therapeutics.

[Clinical study of unrelated umbilical cord blood transplantation in 32 children patients].

To evaluate the clinical efficacy of unrelated umbilical cord blood transplantation (UCBT) on the treatment of children with hematologic malignancies and nonmalignancies, between August 2001 and June 2004, 32 patients were transplanted by using unrelated umbilical cord blood supplied by Shandong Umbilical Cord Blood Bank. Out of them, 13 patients suffered from ALL, 9 from AML, 3 from AA, 3 from HAL, 2 from CML and 2 from NHL. The median age was 8 years (range 2-15), the median weight was 31.5 kg (range 14-55). All patients received ablative conditioning regiment according to the disease and the disease status. Conditioning regiments Cy/TBI were used for 4 patients and Bu/Cy for 21 patients, other for 7 patients. All patients received cyclosporin A and/or methotrexate for GVHD prophylaxis. The mean number of infused nuclear cells were 5.57 (2.16-12.3) x 10(7)/kg, CD34+ cells 1.78 (0.85-5.59) x 10(5). All of UCB units were tested for HLA-A, -B, and DRB1 using low and high resolution techniques. There were HLA-matched in 10, 5/6 in 16 and 4/6 in 6. The results showed that 20 out of 32 patients achieved complete engraftment. Median time of neutrophil > or = 0.5 x 10(9)/L, and platelet > or = 20 x 10(9)/L were 17 (9-38) and 42 (18-102) days respectively. The incidence of aGVHD II-IV and aGVHD III-IV were 35% and 15% respectively. After a median follow-up of 18 months (1.5-28.5), overall survival rate at one year was 59.4%, overall survival rate at two years was 40.6%. It is suggested that UCBT is promising for children patients who is lack of matched bone marrow donors.

[Prediction of acute GVHD after umbilical cord blood transplantation by HLA three-dimensional structure matching].

To explore a method of predicting acute graft versus host disease (aGVHD) after unrelated cord blood transplantation (UCBT), the HLA-A, -B, -DRB1 molecular three-dimensional structures in 25 patients with blood disorder who underwent UCBT and their donors were modeled by using molecular modeling technique. First, full amino acid sequences of each HLA antigen from HLA data banks were loaded down, and then amino acid sequence of extracellular antigen binding region was chosen. Third step, SPDBV software of SWISS-MODEL server was used to modeling the three-dimensional structures of each different allele of HLA-A, -B and -DRB1 between patients and donors and the parameter "root mean square deviation" (RMSD) was used to indicate the structure differences. Last, RMSD of each different HLA allele of each donor-patient pair were added together to get total RMSD. The 25 patients were divided into 3 groups: the first group did not develop aGVHD; the second group developed aGVHD graded I-II and the third group developed aGVHD graded III-IV. The results showed that in the 25 patients divided into three groups, 8 patients in the first group did not develop aGVHD (32%); 13 patients in the second group developed grade I-II of aGVHD (52%) and 4 patients in the third group developed aGVHD III-IV (16%). The total RMSDs of each group were 0.24 +/- 0.15, 0.25 +/- 0.14 and 0.47 +/- 0.22 respectively. The total RMSD of the third group was significantly higher than that of the other two groups. In conclusion, utilization of modeling HLA molecular three-dimension can predict the severe aGVHD after UCBT quickly, simply and accurately. It provides scientific basis in choosing a optimal cord blood donor to avoid severe aGVHD for physicians and the cord blood banks. And it is instructive too to direct the application of immunosuppressive agents after transplantation in clinic.