Isolation and characterization of ZK002, a novel dual function snake venom protein from Deinagkistrodon acutus with anti-angiogenic and anti-inflammatory properties.

Introduction: Pathological angiogenesis, the abnormal or excessive generation of blood vessels, plays an important role in many diseases including cancer, diabetic retinopathy, psoriasis, and arthritis. Additionally, increasing evidence supports the close linkage between angiogenesis and inflammation. Snake venoms are a rich natural source of biologically active molecules and carry rich potential for the discovery of anti-angiogenic and anti-inflammatory modulators. Methods: Here, we isolated and purified a novel protein, ZK002, from the venom of the snake Deinagkistrodon acutus, and investigated its anti-angiogenic and anti-inflammatory activities and mechanisms. Results: ZK002 was identified as a 30 kDa heterodimeric protein of α and ß chains, which exhibited anti-angiogenic activity in various in vitro assays. Mechanistically, ZK002 inhibited activation of VEGF signaling and related mediators including eNOS, p38, LIMK, and HSP27. ZK002 also upregulated the metalloproteinase inhibitor TIMP3 and inhibited components of the VEGF-induced signaling cascade, PPP3R2 and SH2D2A. The anti-angiogenic activity of ZK002 was confirmed in multiple in vivo models. ZK002 could also inhibit the in vitro expression of pro-inflammatory cytokines, as well as in vivo inflammation in the carrageenin-induced edema rat model. Conclusion: Our findings highlight the potential for further development of ZK002 as a dual function therapeutic against diseases with involvement of pathogenic angiogenesis and chronic inflammation.

Revealing the Adsorption Mechanisms of Methanol on Lithium-Doped Porous Carbon through Experimental and Theoretical Calculations.

Previous reports have shown that it is difficult to improve the methanol adsorption performance of nitrogen and oxygen groups due to their low polarity. Here, we first prepared porous carbon with a high specific surface area and large pore volume using benzimidazole as a carbon precursor and KOH as an activating agent. Then, we improved the surface polarity of the porous carbon by doping with Lithium (Li) to enhance the methanol adsorption performance. The results showed that the methanol adsorption capacity of Li-doped porous carbon reached 35.4 mmol g-1, which increased by 57% compared to undoped porous carbon. Molecular simulation results showed that Li doping not only improved the methanol adsorption performance at low pressure, but also at relatively high pressure. This is mainly because Li-modified porous carbon has higher surface polarity than nitrogen and oxygen-modified surfaces, which can generate stronger electrostatic interactions. Furthermore, through density functional theory (DFT) calculations, we determined the adsorption energy, adsorption distance, and charge transfer between Li atom and methanol. Our results demonstrate that Li doping enhances the adsorption energy, reduces the adsorption distance, and increases the charge transfer in porous carbon. The mechanism of methanol adsorption by Li groups was revealed through experimental and theoretical calculations, providing a theoretical basis for the design and preparation of methanol adsorbents.

Efficacy and Safety of Anti-Programmed Death-Ligand 1 Monoclonal Antibody Socazolimab With Carboplatin and Etoposide for Extensive-Stage SCLC: Results From the Phase 1b Clinical Trial.

Introduction: The study (ClinicalTrials.gov, NCT04346914) is an open label, single-arm, phase 1b clinical trial investigating the safety, tolerability, and efficacy of the recombinant human anti-programmed death-ligand 1 monoclonal antibody socazolimab in combination with carboplatin and etoposide in the first-line treatment of extensive-stage SCLC. Good safety and efficacy were found in previous phase 1 clinical trials of other cancers, such as cervix cancer. Methods: Patients received socazolimab (5 mg/kg) every three weeks until disease progression or physician decision. Carboplatin (area under the curve: 5) was also administered every three weeks and etoposide (100 mg/m2) on days 1, 2, and 3 of the treatment cycle. The primary purpose of the study was safety measured by the Common Terminology Criteria for Adverse Events. Secondary purposes included objective response rate, progression-free survival, duration of response, and overall survival. Results: From April 15, 2020 (enrollment date), to December 30, 2021 (data cutoff), 20 patients with extensive-stage SCLC were administered with socazolimab, carboplatin, and etoposide. Objective response rate was 70.0% (95% confidence interval [CI]: 45.72%-88.11%). Median progression-free survival was 5.65 months (95% CI: 4.14-6.54), and the median duration of response was 4.29 months (95% CI: 2.76-5.85). Median overall survival was 14.88 months (95% CI: 10.09-not evaluated). The highest incidence of treatment-related adverse events included anemia (100%), decreased neutrophil count (95%), decreased platelet count (95%), and decreased white blood cell count (95%), which occurred during combination therapy. The most common grade 3 or 4 treatment-related adverse events were neutropenia (90%), decreased white blood cell count (65%), decreased platelet count (50%), and anemia (30%), which were also common adverse reactions of chemotherapy. No adverse events leading to death had occurred. Conclusions: Results revealed that the combination therapy of socazolimab, carboplatin, and etoposide had preliminarily confirmed the safety of socazolimab in the first-line treatment of SCLC combined with EC chemotherapy. Currently, a phase 3, randomized, placebo-controlled trial (ClinicalTrials.gov, NCT04878016) is being conducted with 498 patients.

Organic-inorganic composite modifiers enhance restoration potential of Nerium oleander L. to lead-zinc tailing: application of phytoremediation.

Lead-zinc tailings are complex heavy metal solid wastes produced in the mining process. In this study, two kinds of organic-inorganic mixed improvers mushroom residue + calcium carbonate (M + C) and peat soil + calcium carbonate (N + C) were selected. Then, the effect of two improvers and a woody plant, Nerium oleander L., on the combined remediation of lead-zinc tailings was compared, respectively. The results showed that two combined improvers can slightly improve the pH of tailing, significantly increase the activity of phosphatase and catalase, effectively reduce the contents of DTPA-extractable Pb and Zn, and significantly improve the structure of tailing. However, the improvement effect of M + C was better than that of N + C on tailings' physical and chemical properties. Two improvers can reduce the enrichment and the stress degree of Pb and Zn on the N. oleander and increase the accumulation of Pb and Zn while promoting the growth of the N. oleander. The content of Pb and Zn showed the trend of root > stem > leaf under the two improvers, and the content of Zn was basically higher than that of Pb. To sum up, the combination of two modifiers and N. oleander has a good effect on the remediation of lead-zinc tailings, and the remediation effect of M + C was better than N + C.

Comparing a PD-L1 inhibitor plus chemotherapy to chemotherapy alone in neoadjuvant therapy for locally advanced ESCC: a randomized Phase II clinical trial : A randomized clinical trial of neoadjuvant therapy for ESCC.

BACKGROUND: A Phase II study was undertaken to evaluate the safety and efficacy of the neoadjuvant socazolimab, a novel PD-L1 inhibitor, in combination with nab-paclitaxel and cisplatin for locally advanced esophageal squamous cell carcinoma (ESCC). METHODS: Sixty-four patients were randomly divided between the Socazolimab + nab-paclitaxel + cisplatin (TP) arm (n = 32) and the control arm (n = 32), receiving either socazolimab (5 mg/kg intravenously (IV), day 1) or a placebo with nab-paclitaxel (125 mg/m2 IV, day 1/8) and cisplatin (75 mg/m2 IV, day 1) repeated every 21 days for four cycles before surgery. The primary endpoint was major pathological response (MPR), and the secondary endpoints were pathological complete response (pCR), R0 resection rate, event-free survival (EFS), overall survival (OS), and safety. RESULTS: A total of 29 (90.6%) patients in each arm underwent surgery, and 29 (100%) and 28 (98.6%) patients underwent R0 resection in the Socazolimab + TP and Placebo + TP arms, respectively. The MPR rates were 69.0 and 62.1% (95% Confidence Interval (CI): 49.1-84.0% vs. 42.4-78.7%, P = 0.509), and the pCR rates were 41.4 and 27.6% (95% CI: 24.1-60.9% vs. 13.5-47.5%, P = 0.311) in the Socazolimab + TP and Placebo + TP arms, respectively. Significantly higher incidence rates of ypT0 (37.9% vs. 3.5%; P = 0.001) and T downstaging were observed in the Socazolimab + TP arm than in the Placebo + TP arm. The EFS and OS outcomes were not mature. CONCLUSIONS: The neoadjuvant socazolimab combined with chemotherapy demonstrated promising MPR and pCR rates and significant T downstaging in locally advanced ESCC without increasing surgical complication rates. TRIAL REGISTRATION: Registration name (on clinicaltrials.gov): A Study of Anti-PD-L1 Antibody in Neoadjuvant Chemotherapy of Esophageal Squamous Cell Carcinoma. REGISTRATION NUMBER: NCT04460066.

Safety and Tolerability of Tecarfarin (ATI-5923) in Healthy Chinese Volunteers: Multiple Oral Dose-Escalation Phase I Trial.

BACKGROUND: Tecarfarin (ATI-5923), a structural analog of warfarin, was designed to provide more uniform and stable anticoagulation. OBJECTIVE: We aimed to evaluate the safety, tolerability, pharmacokinetic and pharmacodynamic profile of tecarfarin when administered in multiple ascending doses (MADs) to healthy Chinese volunteers. METHODS: Forty healthy Chinese volunteers were enrolled into four sequential cohorts (10, 20, 30, and 40 mg), with 10 subjects in each cohort. Participants in the MAD study for each sequential cohort were dose-titrated to achieve the target international normalized ratio (INR 1.7-2.0) for 14 days. Safety and tolerability were assessed throughout the study. RESULTS: The pharmacokinetic and pharmacodynamic profile of tecarfarin was investigated in a healthy Chinese population. Dose titration of tecarfarin was necessary to keep the INR in the target range in all subjects in the 20, 30 and 40 mg cohorts and a few subjects (n = 3) in the 10 mg cohort. Tecarfarin was well tolerated without serious adverse events. Only one treatment-related adverse event (hematochezia) resulted in early withdrawal from the MAD 40 mg cohort. CONCLUSION: Tecarfarin was well-tolerated by Chinese volunteers. Dose titration was needed for tecarfarin doses larger than 20 mg to keep the INR in the target range. REGISTRATION: ClinicalTrials.gov identifier: NCT04627116.

First-in-Maintenance Therapy for Localized High-Grade Osteosarcoma: An Open-Label Phase I/II Trial of the Anti-PD-L1 Antibody ZKAB001.

PURPOSE: We investigated the safety and preliminary efficacy of anti-PD-L1 antibody (ZKAB001) as maintenance therapy for localized patients with high-grade osteosarcoma to reduce the risk of recurrence and metastasis. PATIENTS AND METHODS: This open-label Phase I/II study was divided into dose-escalation Phase I and expansion Phase II. Phase I used a 3+3 design with ZKAB001 at three escalating doses ranging: 5, 10, 15 mg/kg every 2 weeks in 9 patients with localized high-grade osteosarcoma and Phase II tested 10 mg/kg in 12 patients for up to 24 cycles. Primary endpoints were safety and tolerability assessed using CTCAE4.0.3. RESULTS: Between October 2018 and 2019, 21 eligible patients were enrolled and accepted ZKAB001 treatment: 9 in the dose-escalation phase, and 12 in expansion phase. Six patients with disease progression withdrew from this study and follow-up is ongoing. The MTD was not defined in Phase I. All doses had a manageable safety profile. The recommended dose in Phase II was set at 10 mg/kg. Most frequent immune-related adverse events were thyroiditis (76.2%) and dermatitis (42.9%). Only 1 (4.8%) of 21 patients had a Grade 3 skin rash. The median 3-year event-free survival (EFS) and overall survival (OS) were not established; however, 24-month EFS was 71.4% (95% confidence interval, 47.2-86.0) and 2-year OS was 100%. Preliminary efficacy data showed EFS benefits in patients with PD-L1 positive or an MSI-H sub-population. CONCLUSIONS: Switching to maintenance using ZKAB001 showed an acceptable safety profile and provided preliminary evidence of clinical activity in localized patients with osteosarcoma.

Lead Responses and Tolerance Mechanisms of Koelreuteria paniculata: A Newly Potential Plant for Sustainable Phytoremediation of Pb-Contaminated Soil.

Phytoremediation could be an alternative strategy for lead (Pb) contamination. K. paniculata has been reported as a newly potential plant for sustainable phytoremediation of Pb-contaminated soil. Physiological indexes, enrichment accumulation characteristics, Pb subcellular distribution and microstructure of K. paniculata were carefully studied at different levels of Pb stress (0-1200 mg/L). The results showed that plant growth increased up to 123.8% and 112.7%, relative to the control group when Pb stress was 200 mg/L and 400 mg/L, respectively. However, the average height and biomass of K. paniculata decrease when the Pb stress continues to increase. In all treatment groups, the accumulation of Pb in plant organs showed a trend of root > stem > leaf, and Pb accumulation reached 81.31%~86.69% in the root. Chlorophyll content and chlorophyll a/b showed a rising trend and then fell with increasing Pb stress. Catalase (CAT) and peroxidase (POD) activity showed a positive trend followed by a negative decline, while superoxide dismutase (SOD) activity significantly increased with increasing levels of Pb exposure stress. Transmission electron microscopy (TEM) showed that Pb accumulates in the inactive metabolic regions (cell walls and vesicles) in roots and stems, which may be the main mechanism for plants to reduce Pb biotoxicity. Fourier transform infrared spectroscopy (FTIR) showed that Pb stress increased the content of intracellular -OH and -COOH functional groups. Through organic acids, polysaccharides, proteins and other compounds bound to Pb, the adaptation and tolerance of K. paniculata to Pb were enhanced. K. paniculata showed good phytoremediation potential and has broad application prospects for heavy metal-contaminated soil.

Metronidazole Degradation by UV and UV/H2O2 Advanced Oxidation Processes: Kinetics, Mechanisms, and Effects of Natural Water Matrices.

Advanced oxidation technology represented by hydroxyl radicals has great potential to remove residual antibiotics. In this study, we systematically compared the metronidazole (MTZ) degradation behavior and mechanism in the UV and UV/H2O2 systems at pH 3.00 condition. The results show that the initial reaction rates were 0.147 and 1.47 µM min-1 in the UV and UV/H2O2 systems, respectively. The main reason for the slow direct photolysis of MTZ is the relatively low molar absorption coefficient (2645.44 M-1 cm-1) and quantum yield (5.9 × 10-3 mol Einstein-1). Then, we measured kMTZ,OH â€¢ as 2.79 (±0.12) × 109 M-1 s-1 by competitive kinetics, and calculated kMTZ,OH â€¢ and [OH â€¢]SS as 2.43 (±0.11) × 109 M-1 s-1 and 2.36 × 10-13 M by establishing a kinetic model based on the steady-state hypothesis in our UV/H2O2 system. The contribution of direct photolysis and •OH to the MTZ degradation was 9.9% and 90.1%. •OH plays a major role in the MTZ degradation, and •OH was the main active material in the UV/H2O2 system. This result was also confirmed by MTZ degradation and radicals' identification experiments. MTZ degradation increases with H2O2 dosage, but excessive H2O2 had the opposite effect. A complex matrix has influence on MTZ degradation. Organic matter could inhibit the degradation of MTZ, and the quenching of the radical was the main reason. NO3- promoted the MTZ degradation, while SO42- and Cl- had no effect. These results are of fundamental and practical importance in understanding the MTZ degradation, and to help select preferred processes for the optimal removal of antibiotics in natural water bodies, such as rivers, lakes, and groundwater.

Efficacy and Safety of the Anti-PD-L1 mAb Socazolimab for Recurrent or Metastatic Cervical Cancer: a Phase I Dose-Escalation and Expansion Study.

PURPOSE: This study (ClinicalTrials.gov identifier, NCT03676959) is an open, phase I dose-escalation and expansion study investigating the safety and efficacy of the recombinant, fully human anti-programmed death ligand 1 (PD-L1) mAb socazolimab in patients diagnosed with recurrent or metastatic cervical cancer. PATIENTS AND METHODS: Patients received socazolimab every 2 weeks until disease progression. The study was divided into a dose-escalation phase and a dose-expansion phase. Safety and tolerability were primary endpoints of the dose-escalation phase. The primary endpoints of the dose-expansion phase were safety and the objective response rate (ORR) of the 5 mg/kg dose. Efficacy was assessed by the third-party independent review committee (IRC) using the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1). RESULTS: 104 patients were successfully enrolled into the study. Twelve patients were included in the dose-escalation phase, with one complete response and two partial responses in the 5 mg/kg treatment group. Ninety-two patients (5 mg/kg) were enrolled in the dose-expansion phase. Fifty-four patients (59.3%) had baseline PD-L1-positive tumor expression (combined positive score ≥1). ORR was 15.4% [95% confidence interval (CI), 8.7%-24.5%]. Median PFS was 4.44 months (95% CI, 2.37-5.75 months), and the median OS was 14.72 months (95% CI, 9.59-NE months). ORR of PD-L1-positive patients was 16.7%, and the ORR of PD-L1-negative patients was 17.9%. No treatment-related deaths occurred. CONCLUSIONS: Our study demonstrates that socazolimab has durable safety and efficacy for the treatment of recurrent or metastatic cervical cancer and exhibits a safety profile similar to other anti-PD-1/PD-L1 mAbs.

Comparison of Phytoremediation Potential of Nerium indicum with Inorganic Modifier Calcium Carbonate and Organic Modifier Mushroom Residue to Lead-Zinc Tailings.

At present, the application of phytoremediation technology in the ecological remediation of heavy metal tailings is receiving more and more attention. In this study, the physiological and biochemical response and tolerance mechanism of woody plant Nerium indicum to Pb and Zn under different proportions of inorganic modifier calcium carbonate (C1: 5%, C2: 10%, C3: 15%) and organic modifier mushroom residue (M1: 10%, M2: 20%, M3: 30%) was compared. The results showed that the pH value has a trend of C group > M group > CK group and organic matter has a trend of M group > CK group > C group. Phosphatase activity and catalase activity has a trend of M group > C group > CK group, but catalase was more vulnerable to the calcium carbonate concentration. Both modifiers can promote the transformation of Pb, Zn, Cu, and Cd in tailings to more stable organic bound and residual states. However, the stabilization effect of mushroom residue is better, and its stability is Pb, Zn > Cd, Cu. Both modifiers can increase the biomass of Nerium indicum and the modification effect of mushroom residue is better than calcium carbonate. Pb/Zn content and accumulation in Nerium indicum organs showed root > stem > leaf in all groups. Compared with the CK group, the enrichment coefficient of Pb/Zn in C1 and M1 groups decreased, while the translocation factor of Pb/Zn in C1 and M1 groups increased. With the increase in modifier concentration, the enrichment coefficient increases about 1.75~52.94%, but the translocation factor decreases rapidly (20.01~64.46%). Clearly, both the calcium carbonate and mushroom residue amendment could promote the growth ability of Nerium indicum in lead−zinc tailings and strengthen the phytoremediation potential.

Anfibatide alleviates inflammation and apoptosis via inhibiting NF-kappaB/NLRP3 axis in ischemic stroke.

Recent evidence suggests that Nod-like receptor protein-3 (NLRP3) inflammasome is a key mediator of inflammatory response and can induce the activation of apoptosis signaling pathways in ischemic stroke. In this research, we assessed the effects of anfibatide (ANF) on inflammatory and apoptosis in cerebral ischemic injury and the potential mechanisms. Middle cerebral artery occlusion (MCAO) model was established on male Sprague-Dawley rats to induce cerebral ischemia/reperfusion (I/R) injury in vivo. Primary cortical neurons (PCN) cells were exposed to oxygen-glucose deprivation and reintroduction (OGD/R) to mimic cerebral I/R injury in vitro. The results showed that ANF markedly alleviated infarct volume, neurological deficit and neurobehavioral impairment in MCAO/R rats, enhanced cell viability and decreased LDH release in PCN after OGD/R. The number of TUNEL-positive cells, Bax, cleaved-caspase-3, p-IκBα, p-p65, NLRP3, ASC, cleaved caspase-1, IL-ß and IL-18 proteins expression were significantly upregulated in the cortex of MCAO/R rats and PCN exposed to OGD/R, NLRP3 and caspase-1 mRNA levels were also evidently elevated. Bcl-2 protein expression significantly decreased in the cortex of MCAO/R rats. Treatment with ANF obviously inhibited the expression of p-IκBα, p-p65, NLRP3, ASC, cleaved caspase-1, Bax and cleaved-caspase-3, promoted the expression of Bcl-2, then decreased the TUNEL-positive cell number and the level of inflammatory cytokines (IL-ß and IL-18) in cerebral ischemia reperfusion in vito and in vitro. Our findings suggest that ANF exerts effects of alleviating inflammation and apoptosis through inhibiting NF-kappaB/NLRP3 axis. ANF is a potential candidate for treating cerebral I/R injury.

Safety and efficacy of a platelet glycoprotein Ib inhibitor for patients with non-ST segment elevation myocardial infarction: A phase Ib/IIa study.

STUDY OBJECTIVE: This study aimed to determine the safety and efficacy of a novel GP Ib receptor inhibitor in patients with non-ST segment elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention (PCI). DESIGN AND SETTING: Multicenter, randomized, double-blind, placebo-controlled, dose-escalating, phase Ib-IIa clinical trial. Eligible patients were randomly assigned to the low-dose (n=20, 2 IU/60 kg), moderate-dose (n=20, 3 IU/60 kg), or high-dose anfibatide group (n=20, 5 IU/60 kg), or the placebo group (n=30). Anfibatide was administered for up to 48 hours along with standard aspirin and clopidogrel therapy. PATIENTS: Ninety patients with NSTEMI who underwent PCI at six academic hospitals in China. MEASUREMENTS AND MAIN RESULTS: All three doses of anfibatide showed dose-dependent antiplatelet activity as measured by ex vivo platelet aggregation at 5 minutes, 24 hours, and 48 hours during infusion, and 4 hours post-infusion compared with placebo. Higher inhibition of platelet aggregation occurred in all anfibatide groups compared with the placebo group. The post-procedural TIMI grade flow, myocardial blush grade, and corrected TIMI frame count were not significantly different among the four groups. Thirty-day mortality, non-fatal myocardial infarction, and major bleeding were rare and comparable between patients who received anfibatide and placebo. There was no significant difference in the platelet count among the groups during follow-up. CONCLUSIONS: This study shows that intravenous administration of the platelet receptor GP Ib antagonist anfibatide is feasible and safe to inhibit platelet aggregation without increasing the risk of bleeding and thrombocytopenia in patients with NSTEMI undergoing PCI.

Pharmacokinetic and pharmacodynamic evaluation of the new prolonged-release leuprorelin acetate microspheres for injection compared with Enantone® in healthy Chinese male volunteers.

PURPOSE: To compare the pharmacokinetics, pharmacodynamics and safety of the new prolonged-release leuprorelin acetate microspheres for injection (3.75 mg) with the reference product Enantone® (3.75 mg). METHOD: 48 healthy male volunteers were enrolled and randomly received a single 3.75 mg dose of the test drug or Enantone®. RESULTS: There were no significant differences in Cmax, AUC0-t and AUC0-48 between the test group and reference group (P > 0.05). The 90% confidence intervals of the two groups were 87.49%~112.74%, 97.15%~154.25%, and 80.85%~109.01%, respectively. Twenty-eight days after administration, both groups reached 100.0% castration level; there was no difference in the time from administration to reaching castration level between the two groups (P > 0.05); However, the difference between the two groups in the duration of castration level was statistically significant (P < 0.05). There were no major or serious adverse events, and the severity was mild to moderate. CONCLUSION: The pharmacokinetic characteristics of leuprorelin in two groups were consistent. The two groups exhibited similar inhibitory effects on testosterone and more subjects in the test group maintained a longer castration time than those in the reference group.

In vitro assessment and phase I randomized clinical trial of anfibatide a snake venom derived anti-thrombotic agent targeting human platelet GPIbα.

The interaction of platelet GPIbα with von Willebrand factor (VWF) is essential to initiate platelet adhesion and thrombosis, particularly under high shear stress conditions. However, no drug targeting GPIbα has been developed for clinical practice. Here we characterized anfibatide, a GPIbα antagonist purified from snake (Deinagkistrodon acutus) venom, and evaluated its interaction with GPIbα by surface plasmon resonance and in silico modeling. We demonstrated that anfibatide interferds with both VWF and thrombin binding, inhibited ristocetin/botrocetin- and low-dose thrombin-induced human platelet aggregation, and decreased thrombus volume and stability in blood flowing over collagen. In a single-center, randomized, and open-label phase I clinical trial, anfibatide was administered intravenously to 94 healthy volunteers either as a single dose bolus, or a bolus followed by a constant rate infusion of anfibatide for 24 h. Anfibatide inhibited VWF-mediated platelet aggregation without significantly altering bleeding time or coagulation. The inhibitory effects disappeared within 8 h after drug withdrawal. No thrombocytopenia or anti-anfibatide antibodies were detected, and no serious adverse events or allergic reactions were observed during the studies. Therefore, anfibatide was well-tolerated among healthy subjects. Interestingly, anfibatide exhibited pharmacologic effects in vivo at concentrations thousand-fold lower than in vitro, a phenomenon which deserves further investigation.Trial registration: Clinicaltrials.gov NCT01588132.

Slounase, a Batroxobin Containing Activated Factor X Effectively Enhances Hemostatic Clot Formation and Reducing Bleeding in Hypocoagulant Conditions in Mice.

Uncontrolled bleeding associated with trauma and surgery is the leading cause of preventable death. Batroxobin, a snake venom-derived thrombin-like serine protease, has been shown to clot fibrinogen by cleaving fibrinopeptide A in a manner distinctly different from thrombin, even in the presence of heparin. The biochemical properties of batroxobin and its effect on coagulation have been well characterized in vitro. However, the efficacy of batroxobin on hemostatic clot formation in vivo is not well studied due to the lack of reliable in vivo hemostasis models. Here, we studied the efficacy of batroxobin and slounase, a batroxobin containing activated factor X, on hemostatic clot composition and bleeding using intravital microcopy laser ablation hemostasis models in micro and macro vessels and liver puncture hemostasis models in normal and heparin-induced hypocoagulant mice. We found that prophylactic treatment in wild-type mice with batroxobin, slounase and activated factor X significantly enhanced platelet-rich fibrin clot formation following vascular injury. In heparin-treated mice, batroxobin treatment resulted in detectable fibrin formation and a modest increase in hemostatic clot size, while activated factor X had no effect. In contrast, slounase treatment significantly enhanced both platelet recruitment and fibrin formation, forming a stable clot and shortening bleeding time and blood loss in wild-type and heparin-treated hypocoagulant mice. Our data demonstrate that, while batroxobin enhances fibrin formation, slounase was able to enhance hemostasis in normal mice and restore hemostasis in hypocoagulant conditions via the enhancement of fibrin formation and platelet activation, indicating that slounase is more effective in controlling hemorrhage.

Anfibatide Preserves Blood-Brain Barrier Integrity by Inhibiting TLR4/RhoA/ROCK Pathway After Cerebral Ischemia/Reperfusion Injury in Rat.

The disruption of the blood-brain barrier (BBB) and the consequent brain edema are major contributors to the pathogenesis of cerebral ischemia/reperfusion injury. RhoA is generally thought to play a crucial role in the process of BBB disruption and participate in the signaling pathways emanating from TLR4. However, it remains unverified the regulatory role of TLR4 in the RhoA/ROCK pathway in cerebral I/R injury and its effects on the BBB as well. The present study probes into the protective effect of ANF on the BBB after cerebral I/R injury and the possible mechanisms. Focal cerebral ischemia was induced by 120 min of transient middle cerebral artery occlusion (MCAO). ANF (1, 2, 4 µg/kg) was achieved by intravenous injection after 120 min of MCAO followed by 1, 24, 48, and 72 h reperfusion. Evans blue extravasation, brain water content, RhoA activity, and the expressions of TLR4, ROCK1/2, p-MLC2, MMP-2/9, ZO-1, occludin, and claudin-5 protein in rat brain were evaluated 72 h after reperfusion. ANF could significantly reduce the Evans blue extravasation and water content in the ipsilateral hemisphere and obviously increase the occludin, claudin-5, and ZO-1 expression after cerebral I/R injury. Furthermore, cerebral I/R injury induced apparently increased expression of TLR4, RhoA-GTP, ROCK1/2, p-MLC2, and MMMP-2/9, which, however, could be remarkably alleviated by ANF intervention. Taken together, the TLR4/RhoA/ROCK signaling pathway is implicated in BBB breakdown after cerebral I/R injury, and ANF preserves BBB integrity, probably via inhibiting the TLR4/RhoA/ROCK signaling pathway.

Platelet Protein Disulfide Isomerase Promotes Glycoprotein Ibα-Mediated Platelet-Neutrophil Interactions Under Thromboinflammatory Conditions.

BACKGROUND: Platelet-neutrophil interactions contribute to vascular occlusion and tissue damage in thromboinflammatory disease. Platelet glycoprotein Ibα (GPIbα), a key receptor for the cell-cell interaction, is believed to be constitutively active for ligand binding. Here, we established the role of platelet-derived protein disulfide isomerase (PDI) in reducing the allosteric disulfide bonds in GPIbα and enhancing the ligand-binding activity under thromboinflammatory conditions. METHODS: Bioinformatic analysis identified 2 potential allosteric disulfide bonds in GPIbα. Agglutination assays, flow cytometry, surface plasmon resonance analysis, a protein-protein docking model, proximity ligation assays, and mass spectrometry were used to demonstrate a direct interaction between PDI and GPIbα and to determine a role for PDI in regulating GPIbα function and platelet-neutrophil interactions. Also, real-time microscopy and animal disease models were used to study the pathophysiological role of PDI-GPIbα signaling under thromboinflammatory conditions. RESULTS: Deletion or inhibition of platelet PDI significantly reduced GPIbα-mediated platelet agglutination. Studies using PDI-null platelets and recombinant PDI or Anfibatide, a clinical-stage GPIbα inhibitor, revealed that the oxidoreductase activity of platelet surface-bound PDI was required for the ligand-binding function of GPIbα. PDI directly bound to the extracellular domain of GPIbα on the platelet surface and reduced the Cys4-Cys17 and Cys209-Cys248 disulfide bonds. Real-time microscopy with platelet-specific PDI conditional knockout and sickle cell disease mice demonstrated that PDI-regulated GPIbα function was essential for platelet-neutrophil interactions and vascular occlusion under thromboinflammatory conditions. Studies using a mouse model of ischemia/reperfusion-induced stroke indicated that PDI-GPIbα signaling played a crucial role in tissue damage. CONCLUSIONS: Our results demonstrate that PDI-facilitated cleavage of the allosteric disulfide bonds tightly regulates GPIbα function, promoting platelet-neutrophil interactions, vascular occlusion, and tissue damage under thromboinflammatory conditions.

Platelet glycoprotein receptor Ib blockade ameliorates experimental cerebral ischemia-reperfusion injury by strengthening the blood-brain barrier function and anti-thrombo-inflammatory property.

Blood-brain barrier (BBB) disruption, thrombus formation and immune-mediated inflammation are important steps in the pathophysiology of cerebral ischemia-reperfusion injury but are still inaccessible to therapeutic interventions. Recent studies have provided increasing evidence that blocking of platelet glycoprotein (GP) receptor Ib might represent a novel target in treating acute ischemic stroke. This research was conducted to explore the therapeutic efficacy and potential mechanisms of GPIbα inhibitor (anfibatide) in a model of brain ischemia-reperfusion injury in mice. Male mice underwent 90 min of right middle cerebral artery occlusion (MCAO) followed by 24 h of reperfusion. Anfibatide (1, 2, 4 ug/kg) or tirofiban were administered intravenously 1 h after reperfusion. The results showed that anfibatide could significantly reduce infarct volumes, increase the number of intact neuronal cells and improve neurobehavioral function. Moreover, anfibatide could reduce post ischemic BBB damage by attenuating increased paracellular permeability in the ischemia hemisphere significantly. Stroke-induced increases in activity and protein expression of macrophage-1 antigen (MAC-1) and P-selectin were also reduced by anfibatide intervention. Finally, anfibatide exerted antithrombotic effects upon stroke by decreased the number of microthrombi formation. This is the first demonstration of anfibatide's efficacy in protecting the BBB integrity and decreasing neutrophil inflammation response mediated by MAC-1 besides microthrombus formation inhibition in the brain during reperfusion. Anfibatide, as a promising anti-thrombo-inflammation agent, could be beneficial for the treatment of ischemic stroke.

In Vitro and In Vivo Anticancer Activity of Gimatecan against Hepatocellular Carcinoma

Objective: Gimatecan is a new camptothecin (CPT) analogue that inhibits tumor growth by targeting DNA topoisomerase I (TOP I) and introducing strong and persistent DNA cleavage. Anti-tumor activity has been demonstrated with a wide range of solid tumors in previous preclinical and clinical studies. Here, we investigated for the first time the effects of gimatecan on the proliferation of hepatocellular carcinoma (HCC) cells both in vitro and in vivo. Methods: Anticancer efficacy of gimatecan were evaluated in a panel of HCC cell lines and corresponding mouse xenograft models. Inhibition of cell proliferation was measured by CellTiter-Glo cell viability assay. In vivo, gimatecan and control preparations were orally administered every four days, for a total of four times. Tumor volume and body weights of the mice were measured twice weekly. Results: In vitro cytotoxicity evaluation showed that gimatecan inhibited the proliferation of a large panel of HCC cell lines in a dose dependent manner, with IC50 values ranging between 12.1~1085.0 nM. In vivo evaluation in mouse xenograft models showed significant antitumor effects of gimatecan at 0.8mg/kg and 0.4mg/kg as compared to the control group. Conclusion: This study suggested that gimatecan may have the potential to be used as a chemotherapeutic agent for the treatment of HCC.