Haiqiang Jin

Ultrasound-triggered thrombolysis using urokinase-loaded nanogels

To find a way to modulate the effect of thrombolytic proteins by increasing their specificity, minimizing their adverse effect as well as lengthening their circulation time for the treatment of ischemic vascular disease holds great promise. In this work, urokinase-type plasminogen activator (uPA) was encapsulated into hollow nanogels which are generated by the reaction of glycol chitosan and aldehyde capped poly(ethylene glycol) (OHC-PEG-CHO) through a one-step approach of ultrasonic spray. The uPA-loaded nanogels, with size of 200-300 nm, have longer circulation time than that of the nude urokinase in vivo, besides the protein can be triggered to release in faster rate under diagnostic ultrasonic condition of 2 MHz, which significantly enhanced the thrombolysis of clots. The results are promising for increasing the specificity and positive effects of thrombolytic agents like recombinant tissue plasminogen activator (rt-PA) for the current treatment of ischemic vascular disease.

Comparison of Risk Factor between Lacunar Stroke and Large Artery Atherosclerosis Stroke: A Cross-Sectional Study in China

Background Stroke is the second most common cause of mortality in China. Although most subtypes of ischemic stroke share similar risk factors, they have different etiologies. Our study aimed to evaluate the different risk factor profiles between the stroke subtypes, lacunar infarcts (LI) and large-artery atherosclerosis (LAA), and clarify the characteristics of current acute ischemic stroke in China. Methods In this cross-sectional study, we analyzed the clinical characteristics of 1982 patients with acute ischemic stroke who were admitted to the neurology department at the Peking University First Hospital between 2007 and 2014. Ischemic stroke was further classified into LAA, LI, cardioembolism (CE) and undetermined causes of infarction (UDI) according to TOAST classification. Demographic characteristics, risk factors, as well as the findings of laboratory and imaging tests of 1773 patients with LAA and LI, were analyzed by univariate and multivariate logistic analysis. Results Of the 1982 ischemic stroke patients included in this study, 1207 were diagnosed with LAA, 566 with LI, 173 with cardioembolism (CE) and 36 with undetermined causes of infarction (UDI). By comparing the risk factors in multivariate logistic regression analysis, hypertension [odds ratio (OR) = 1.832] and white matter leukoaraiosis (WML) (OR = 1.865) were found to be more strongly correlated with LI than LAA. Low density lipoprotein- cholesterol (LDL-c) (OR = 0.774) were more strongly related to LAA than LI. Conclusions This study found that hypertension and WML were more strongly correlated with LI than LAA. LDL-c was more strongly related to LAA than LI.

PEG-urokinase nanogels with enhanced stability and controllable bioactivity

Protein nanogels were synthesized via a one-step reaction procedure by crosslinking urokinase with benzaldehyde bifunctionalized poly(ethylene glycol). The crosslinked architecture significantly enhances the stability of urokinase against enzyme degradation in comparison with the core–shell structural PEGylated proteins. Meanwhile, bioactivity of the urokinase incorporated in the nanogels can be adjusted by varying the chain length of the corsslinking polymer. With a shorter crosslinker the bioactivity of the uPA nanogels is seriously restricted under physiological conditions. However, the restricted bioactivity can be completely launched by either enlarging the mesh size of the nanogel by using longer crosslinkers, or treating the nanogels in endosomal conditions to dissociate the nanogel structure due to the reversible conjugation chemistry.

Association between Low Estimated Glomerular Filtration Rate and Risk of Cerebral Small-Vessel Diseases: A Meta-Analysis

BACKGROUND Although chronic kidney disease has been linked to cerebral small-vessel disease (CSVD), a definite relationship between them has not been established. This study assessed whether low estimated glomerular filtration is associated with risk of different subtypes of CSVDs. METHODS Electronic databases were systematically searched for studies reporting an odds ratio of the association between low estimated glomerular filtration and CSVD risk. Sixteen studies, including 10,534 participants, were identified. A fix effects model was applied and odds ratios (ORs) with 95% confidence intervals were presented. RESULTS Overall, risk of CSVDs was greater in individuals with low estimated glomerular filtration (OR = 2.20). Stratified analyses consistently showed significant associations across different subtypes, with pooled OR being greatest in subjects with silent cerebral infarction (SCI) (OR = 2.71) and cerebral microbleed (OR = 2.70). A pooled estimate of studies showing OR as a continuous variable showed results consistent with the former analysis (OR = .98 per standard deviation decrease) in low estimated glomerular filtration. CONCLUSIONS This study revealed that low estimated glomerular filtration was significantly associated with risk of CSVDs. Low estimated glomerular filtration was most strongly associated with SCI (OR = 2.71) among subtypes of CSVDs.

pH gradient difference around ischemic brain tissue can serve as a trigger for delivering polyethylene glycol-conjugated urokinase nanogels.

BACKGROUND AND PURPOSE pH-sensitive polyethylene glycol-conjugated urokinase nanogels (PEG-UKs) were previously reported to be a new form of UK nanogels that could release UK at certain pH values. In this study, we evaluated the effect of PEG-UK targeted to ischemic tissue with microcirculation failure in rat model of ischemic stroke and investigated the possible mechanisms of action. METHODS Surgeries were performed to induce persistent middle cerebral artery (MCA) occlusion in adult Sprague-Dawley rats. The pH distribution in the brain was mapped 1h after ischemia using a needle-type pH micro sensor. The release curve of active UK from PEG-UK was also mapped by a continuous measurement of the peripheral blood. The thrombolytic effects of PEG-UK, when it was administrated 1h after occlusion, including dynamic changes in the D-dimer level, neurological deficits and infarction volume, were observed. Next, the possible mechanisms underlying these effects were explored, including the BBB integrity and the extent of apoptosis and neurotoxicity. Additionally, the long-term effects of PEG-UK during the four weeks after treatment were evaluated using the dynamic changes in the body weights and clinical scores and the numbers of deaths and hemorrhagic transformations (HTs). To evaluate the systemic side effects of PEG-UK, the fluctuations of cytokines in the liver and kidney were evaluated. RESULTS On average, MCA occlusion for 1h induced an approximately 0.49 decline in the pH value (from 7.12 to 6.73), and the lowest value was 6.32 in the predominantly affected region around the cortex. PEG suspended the release of UK from PEG-UK into the circulation. When it was administrated 1h after occlusion, PEG-UK treatment clearly reduced the severity of neurological deficits in the acute phase (P=0.001). The relative infarct volume also decreased significantly in PEG-UK rats (P<0.001). As to the integrity of BBB, the EB leakage in the PEG-UK group was reduced (P=0.001). Maintenance of the expression of TIMP-1 (P=0.032) and claudin5 (P<0.001) and inhibition of MMP9 upregulation (P<0.001) were observed through both immunohistochemistry and Western blot in the PEG-UK group. Moreover, the expression of both NMDAR1 (P<0.001) and Caspase9 (P=0.013) in PEG-UK-treated rats was reduced. As to the long-term prognosis, the rats in PEG-UK group recovered faster and better, and the numbers of deaths and HTs were not increased. No significant fluctuation in IL-1β and TNF-α was found in the PEG-UK-treated rats during the four post-treatment weeks. When PEG-UK was administrated 2.5h after occlusion, no clearly better outcomes were observed; however, the number of HTs was not increased. CONCLUSIONS Treatment with PEG-UK decreased the severity of ischemic stroke by improving ischemic brain tissue and protecting the BBB and by inhibiting apoptosis and decreasing neurotoxicity. PEG-UK could further inhibit HT through its BBB protection effect. The administration of PEG-UK also improved the long-term prognosis and had no obvious systemic side effects in rats. Our data provide new insights into the thrombolytic treatment of ischemic stroke.

Variability of warfarin dose response associated with CYP2C9 and VKORC1 gene polymorphisms in Chinese patients

Objective To investigate the prevalence and implication of cytochrome P450, family 2, subfamily C, polypeptide 9 (CYP2C9) variants and vitamin K epoxide reductase complex, subunit 1 (VKORC1)-1639 G > A polymorphisms in Chinese patients receiving warfarin therapy. Methods Chinese Han patients requiring oral warfarin therapy were consecutively enrolled. Correlations between CYP2C9*1, *2, *3, *4, *5 variants and VKORC1-1639 G > A polymorphisms, fourth-day international normalized ratios (INRs) and warfarin maintenance dose were investigated. Results Out of 101 patients, there were no significant differences in fourth-day INR or warfarin daily maintenance doses between patients with CYP2C9*1*1 and CYP2C9*1*3 genotypes. Patients with the VKORC1-1639 AA genotype had a higher fourth-day INR (1.87 ± 0.14) than those with the VKORC1-1639 AG genotype (1.32 ± 0.15). Warfarin maintenance dose for patients with the VKORC1-1639 AA genotype (2.40 ± 0.70 mg/day) was significantly lower than for patients with the VKORC1-1639 AG genotype (4.83 ± 0.70 mg/day). Conclusions Unlike Caucasian populations, VKORC1-1639 G > A polymorphisms in the Chinese population may be the dominant genetic factors associated with warfarin response variability.

Anti-ganglioside antibodies in Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy in Chinese patients.

Introduction: In this study we investigated the relationships between anti‐ganglioside antibodies and Guillain–Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: Samples from 48 Chinese patients diagnosed with GBS and 18 patients diagnosed with CIDP were retrospectively reviewed. Results: In the GBS patients, 62.5% were classified as having acute inflammatory demyelinating polyneuropathy (AIDP), 27.1% were found to have acute motor axonal neuropathy (AMAN), and 10.4% were unclassified. Serum IgG anti‐ganglioside antibodies were detected in 46.2% of the AMAN patients and in 6.7% of the AIDP patients (P < 0.05); 5.6% of the 18 CIDP patients were IgG antibody positive, and 27.8% were IgM antibody positive. Facial palsy and sensory impairment were significantly associated with IgM antibodies. Conclusions: These results suggest that IgG anti‐GM1 antibodies are associated with AMAN, but not with AIDP, and that IgM antibodies against GM1, GM2, and GM3 are associated with facial nerve palsy. Muscle Nerve 55: 470–475, 2017

Treatment with the herbal medicine, naoxintong improves the protective effect of high‑density lipoproteins on endothelial function in patients with type 2 diabetes

The protective effect of high-density lipoprotein (HDL) on endothelial function is impaired in patients with type 2 diabetes mellitus (T2DM), which may result in atherosclerotic complications. Naoxintong (NXT) is a compound preparation that includes Radix Astragali, Angelicae sinensis, Radix Paeoniae Rubra and Ligusticum wallichii. It is widely administered in China to prevent atherosclerotic complications. In the present study, NXT was administered to 69 patients with T2DM. HDLs were isolated from patient blood samples prior to and following the intervention. In vitro endothelial functions of HDL, including proliferation, migration, angiogenesis, and anti-apoptosis were investigated by bromodeoxyuridine, wound healing, Transwell and Matrigel tube formation assays on human umbilical vein endothelial cells (HUVECs). The results from the present study demonstrated that HUVECs treated with HDL isolated from diabetic patients following NXT therapy exhibited increased proliferative effects (10–27%; P<0.05), and improved migration ability (15–35%; P<0.05), anti-apoptotic function (23–34%; P<0.05) and angiogenesis (30–54%; P<0.001). Furthermore, the phosphorylation levels of Akt (26–36%; P<0.01) and extracellular signal-regulated kinase (16–80%; P<0.01) were increased following NXT therapy. The present in vitro study demonstrates that the protective effect of HDL on endothelial function is markedly impaired in diabetic patients who tend to develop atherosclerosis, and the impaired function may be partly abrogated by NXT.

Autophagy inhibits C2-ceramide-mediated cell death by decreasing the reactive oxygen species levels in SH-SY5Y cells

Ceramide has been recognized as a second messenger that regulates several intracellular processes in neuronal cells. However, its role in neuronal autophagy is not fully understood. In this study, we used a human neuroblastoma cell line (SH-SY5Y) to investigate the mechanisms underlying C2-ceramide-mediated cell death and autophagy. C2-ceramide induced caspase-3-independent cell death. In addition, C2-ceramide induced autophagy, decreased the activation of Akt and mTOR, and increased the activation of JNK and ERK1/2. However, only inhibition of ERK1/2 with PD98059 prevented C2-ceramide-induced autophagy, indicating that the ERK1/2 pathway contributes to ceramide-induced autophagy. According to the results of the flow cytometric assays, C2-ceramide-induced cell death was increased by 3-methyadenine (3-MA) and decreased by rapamycin. Furthermore, the generation of reactive oxygen species (ROS) in the cells was increased by 3-MA and decreased by rapamycin. Based on these datas, autophagy protected SH-SY5Y cells from C2-ceramide-induced cell death by decreasing ROS production. Therapeutic strategies that regulate autophagy may be used in the treatment of neurological disorders associated with ceramide-induced cell death.

In vivo evaluation of urokinase-loaded hollow nanogels for sonothrombolysis on suture embolization-induced acute ischemic stroke rat model

The urokinase-type plasminogen activator (uPA) loaded hollow nanogels (nUK) were synthesized by a one-step reaction of glycol chitosan and aldehyde capped poly (ethylene oxide). The resultant formulation is sensitive to diagnostic ultrasound (US) of 2 MHz. Herein, we evaluated the in vivo sonothrombolysis performance of the nUK on acute ischemic stroke rat model which was established by suture embolization of middle cerebral artery (MCA). Via intravenous (i.v.) administration, the experimental data prove a controlled release of the therapeutic protein around the clots under ultrasound stimulation, leading to enhanced thrombolysis efficiency of the nUK, evidenced from smaller infarct volume and better clinical scores when compared to the i.v. dose of free uPA no matter with or without US intervention. Meanwhile, the preservation ability of the nanogels not only prolonged the circulation duration of the protein, but also resulted in the better blood-brain barrier protection of the nUK formulation, showing no increased risk on the hemorrhagic transformation than the controls. This work suggests that the nUK is a safe sonothrombolytic formulation for the treatment of acute ischemic stroke.