Extracellular cold-inducible RNA-binding protein mediated neuroinflammation and neuronal apoptosis after traumatic brain injury.

Background: Extracellular cold-inducible RNA-binding protein (eCIRP) plays a vital role in the inflammatory response during cerebral ischaemia. However, the potential role and regulatory mechanism of eCIRP in traumatic brain injury (TBI) remain unclear. Here, we explored the effect of eCIRP on the development of TBI using a neural-specific CIRP knockout (KO) mouse model to determine the contribution of eCIRP to TBI-induced neuronal injury and to discover novel therapeutic targets for TBI. Methods: TBI animal models were generated in mice using the fluid percussion injury method. Microglia or neuron lines were subjected to different drug interventions. Histological and functional changes were observed by immunofluorescence and neurobehavioural testing. Apoptosis was examined by a TdT-mediated dUTP nick end labelling assay in vivo or by an annexin-V assay in vitro. Ultrastructural alterations in the cells were examined via electron microscopy. Tissue acetylation alterations were identified by non-labelled quantitative acetylation via proteomics. Protein or mRNA expression in cells and tissues was determined by western blot analysis or real-time quantitative polymerase chain reaction. The levels of inflammatory cytokines and mediators in the serum and supernatants were measured via enzyme-linked immunoassay. Results: There were closely positive correlations between eCIRP and inflammatory mediators, and between eCIRP and TBI markers in human and mouse serum. Neural-specific eCIRP KO decreased hemispheric volume loss and neuronal apoptosis and alleviated glial cell activation and neurological function damage after TBI. In contrast, eCIRP treatment resulted in endoplasmic reticulum disruption and ER stress (ERS)-related death of neurons and enhanced inflammatory mediators by glial cells. Mechanistically, we noted that eCIRP-induced neural apoptosis was associated with the activation of the protein kinase RNA-like ER kinase-activating transcription factor 4 (ATF4)-C/EBP homologous protein signalling pathway, and that eCIRP-induced microglial inflammation was associated with histone H3 acetylation and the α7 nicotinic acetylcholine receptor. Conclusions: These results suggest that TBI obviously enhances the secretion of eCIRP, thereby resulting in neural damage and inflammation in TBI. eCIRP may be a biomarker of TBI that can mediate the apoptosis of neuronal cells through the ERS apoptotic pathway and regulate the inflammatory response of microglia via histone modification.

Neuroimmune Regulation in Sepsis-Associated Encephalopathy: The Interaction Between the Brain and Peripheral Immunity.

Sepsis-associated encephalopathy (SAE), the most popular cause of coma in the intensive care unit (ICU), is the diffuse cerebral damage caused by the septic challenge. SAE is closely related to high mortality and extended cognitive impairment in patients in septic shock. At present, many studies have demonstrated that SAE might be mainly associated with blood-brain barrier damage, abnormal neurotransmitter secretion, oxidative stress, and neuroimmune dysfunction. Nevertheless, the precise mechanism which initiates SAE and contributes to the long-term cognitive impairment remains largely unknown. Recently, a growing body of evidence has indicated that there is close crosstalk between SAE and peripheral immunity. The excessive migration of peripheral immune cells to the brain, the activation of glia, and resulting dysfunction of the central immune system are the main causes of septic nerve damage. This study reviews the update on the pathogenesis of septic encephalopathy, focusing on the over-activation of immune cells in the central nervous system (CNS) and the "neurocentral-endocrine-immune" networks in the development of SAE, aiming to further understand the potential mechanism of SAE and provide new targets for diagnosis and management of septic complications.

Develop a novel superparamagnetic nano-carrier for drug delivery to brain glioma.

Magnetic drug carrier has been employed in drug delivery for over 30 years. Modern nanotechnology has improved its efficiency dramatically by decreasing its diameter into nano-scale. It may help chemotherapeutic agents penetrate BBB and raise local drug concentration in brain, which is the ideal model for glioma treatment. In our study, magnetic carrier was fabricated with octadecyl quaternized caroxymethyl chitosan (OQCMC), hydrophobic Fe3O4 ferrofluid and cholesterol, which showed a uniform diameter of 20 nm under transmission electronic microscopy and superparamagnetic character in vibration sample magnetical measurement system. To investigate the efficacy of drug delivery, paclitaxel was used as loaded drug and analyzed by the HPLC. Results showed that magnetic carrier released drugs for more than 20 d in vitro and maintain the drug concentration above 0.4 µg/g for 16 h in rat brain after magnetic targeting. Drug concentration increased by 1-3 folds when delivered by carrier without magnetic targeting, and by 3-15 folds after magnetic targeting. Cellular study revealed that the magnetic carrier was clearly localized in the targeted cortex neural cells and U251-MG cell lines. These results showed that this magnetic carrier is capable of maintaining high drug concentration in magnetically targeted area and carrying drugs or genes into cells, which is potentially promising for local chemotherapy to brain tumors.

Nano-sized cationic polymeric magnetic liposomes significantly improves drug delivery to the brain in rats.

In recent years, cationic polymeric magnetic liposomes have shown greater stability and prolonged circulation half-life over traditional liposomes. Here, we examined the capability of cationic polymeric magnetic liposomes in delivering drugs into the brain under magnetic targeting with paclitaxel as the loaded agent. We found that the fabricated paclitaxel-loaded magnetic liposomes had a uniform diameter of 20 nm and were superparamagnetic. After they were injected into rats by the caudal vein, brain paclitaxel concentration increased 2-5 folds without magnetic targeting and 5-15 folds after magnetic targeting. The high brain concentration was maintained for more than 8 h, which was significantly longer than that for pure paclitaxel injection. When the liposomes were given via the internal carotid artery at 10% of the dose given via the caudal vein, paclitaxel in the brain was increased by 1.5 folds, indicating that intra-arterial administration enhanced delivery efficiency remarkably. Prussian blue staining of the cortex showed that the magnetic liposomes were aggregated in the cortex vasculature and the cortex cells were under magnetic targeting, indicating that the drugs were delivered across the nearly impermeable blood-brain barrier. These results showed that the nano-sized cationic polymeric magnetic liposomes are potential tools for magnetic drug delivery to the brain.

[Preparation of superparamagnetic paclitaxel nanoparticles from modified chitosan and their cytotoxicity against malignant brain glioma].

We synthesized the superparamagnetic paclitaxel nanoparticles from modified chitosan tangling around Fe3O4 ferrofluid and taxol, and observed the nanoparticles with transmission electronic microscopy (TEM). Then we evaluated the paramagnetism of the particles by vibration specimen magnetometer (VSM) and tested their cytotoxicity with flow cytometry (FCM). The prepared nanoparticle solution was black without any floccule or sediment and appeared transparent after diluted. The nanoparticles were spherical and dispersed in water with mean diameter of 15 nm under TEM and showed superparamagnetic character. FCM test showed the nanoparticles had significant toxic effects against malignant astrocytoma U251 cell lines, equal to taxol alone. These results showed that the superparamagnetic nanoparticle not only enhanced the solubility of paclitaxel in water, but also was superparamagnetic and cytotoxic, which make suitable tools for magnetic targeting chemotherapy of brain gliomas.

HMGN5: a potential oncogene in gliomas.

Gliomas are the most common primary brain tumors in the central nervous system and a leading cause of tumor-related death. High-mobility group nucleosome binding domain 5 (HMGN5/NSBP1), which is highly expressed in breast cancer and in hormone-induced mouse uterine adenocarcinoma, acts as a potential oncogene in gliomas. In this study, the role of HMGN5 in the proliferation of human glioma cells was investigated by lentivirus-mediated RNA interference (RNAi). The decrease in HMGN5 expression in human glioma U251 and U87 cells caused cell cycle arrest in the G1 phase and a delay in cell proliferation, as well as resulting in more apoptosis and an inhibition of clonogenic growth in soft agar in U251 cells; these results suggest that HMGN5 is required for tumorigenesis in vitro. Furthermore, HMGN5 was highly expressed in both high-grade and low-grade glioma tissue samples compared with normal brain tissues. Collectively, our data suggest that HMGN5 may play a critical role in the development of gliomas.

[Establishment of a Wistar rat model bearing brain glioma C6 cells and its experimental application].

OBJECTIVE: To establish a rat model bearing brain glioma and investigate the optimal conditions for its experimental application. METHODS: C6 cells were implanted into the unilateral brain hemisphere of 20 Wistar rats. The growth behaviors of the brain tumor and behavioral changes of the rats were observed at different time points after the implantation. RESULTS: On day 3 after the implantation, only a slight increase of signal intensity was observed on T2-weighted images. By day 5, the tumor became visible in 15/18 of the rats in at least two sections. By day 11, 16/18 of the rats showed space-occupying effect in the brain, and by day 14, the tumor occupied over 1/2 of the hemisphere in 14/18 of the rats. By day 20, 14/18 of the rats showed a tumor mass occupying over 2/3 of the hemisphere, and some tumor cells had migrated into the contralateral hemisphere. CONCLUSION: In this model of brain glioma, the optimal time widow for experiment is between 14 and 18 days after the cell implantation. The cell density and viability for implantation and the site of implantation may also affect the experimental time widow.

Magnetic paclitaxel nanoparticles inhibit glioma growth and improve the survival of rats bearing glioma xenografts.

UNLABELLED: Paclitaxel has fared poorly in clinical trials against brain glioma. We hypothesized that superparamagnetic nanocarriers may enhance its bioactivities by delivering it into the brain. MATERIALS AND METHODS: The magnetic paclitaxel nanoparticles (MPNPs) were fabricated and their cytotoxicity against glioma was tested both in vitro and in glioma-bearing rats. RESULTS: MPNPs exhibited superparamagnetism and produced an extended release of paclitaxel over 15 days in vitro. They were easily internalized into glioma cells and exerted remarkable toxicity, as free paclitaxel did. Furthermore, after intravenous injection of MPNPs to glioma-bearing rats and magnetic targeting with a 0.5 T magnet, drug content increased for 6- to 14-fold in implanted glioma and 4.6- to 12.1-fold in the normal brain compared to free paclitaxel. The survival of glioma-bearing rats was significantly prolonged after magnetic targeting therapy with MPNPs. CONCLUSION: MPNPs efficiently delivered paclitaxel into brain glioma by magnetic targeting and enhance its antitumor activity. They are promising for local chemotherapy for malignant glioma.

[Ocular manifestations of brainstem tumor].

OBJECTIVE: To investigate the ocular manifestations of brainstem tumors and to avoid misdiagnosis and missed diagnosis. METHODS: This is a retrospective case series study. The clinical data of 57 brainstem tumor in-patients were collected from 1993 to 2007. The clinical manifestations and the results of related examinations were analyzed. RESULTS: The present series included 51 cases of brainstem germinoma, 4 cases of cavernous hemangioma, 1 case of hemangioblastoma and 1 case of metastatic tumor. In 51 cases of brainstem germinoma, there were 37 males and 14 females. The first attack age varied from 5 to 55 years old and the median age was 23 years old. The high incident ages of brainstem germinoma were 10 - 35 years. Patients were presented with diplopia, ocular motility disturbance, nystagmus, anisocoria, and facial palsy. In 57 patients, diplopia was the initial symptom in 12.3% (7/57) cases. The incidence of oculomotor nerve paralysis was 17.5% (10/57); trochlear paralysis, 1.8% (1/57); trigeminal nerve paralysis, 5.3% (3/57); abducens nerve paralysis, 35.1% (20/57); facial palsy, 14.0% (8/57); optic disc edema, 19.3% (11/57); nystagmus, 21.1% (12/57) and anisocoria, 10.5% (6/57). CONCLUSIONS: Ocular manifestations occur frequently in brainstem tumor. Nuclear ophthalmoplegia, nystagmus and other neuro-ophthalmic signs provide helpful clues for the diagnosis of brainstem tumor.

Localization and distribution of magnetic chemotherapeutic drugs with magnetic targeting in rat brain.

BACKGROUND: Magnetic targeting therapy may be a new method for the treatment of malignent tumors. The purpose of this study was to investigate the localization and distribution of ferrofluid microsphere of human serum albumin methotrexate (FM-HSA-MTX) carriers in the brain and to explore the magnetic targeting chemotherapy for malignant brain tumor. METHODS: Ninety SD rats were divided into three groups: targeting group, non-magnetic targeting group, and control group. Synthesized FM-HSA-MTX carriers (MTX 25 mg/kg) were injected into the systemic circulation via the caudal vein (magnetic targeting group, n = 30). A 0.6 T magnetic field was placed around the right hemisphere. The non-magnetic targeting group (n = 30) was administered with FM-HSA-MTX without external magnetic field, meanwhile the control group (n = 30) was treated with MTX and a magnetic field. Random serial sacrifices (n = 10) were conducted at 15, 30 and 45 minutes after drug administration. Bilateral hemispheres were collected respectively, and analyzed for total MTX content. RESULTS: MTX content in the right hemisphere of the magnetic targeting group was significantly higher than that in the other two groups at 15, 30 and 45 minutes after drug administration (P < 0.05) No difference was seen between the non-targeting group and control group. In the magnetic targeting group, MTX returned to the peak level [(0.564 +/- 0.018) mg/g, q15-45 = 32.252, P < 0.05] 45 minutes after the injection but it deceased in the other two groups [non-magnetic targeting group: (0.060 +/- 0.015) mg/g, q15-45 = 9.245, P < 0.05, control group: (0.074 +/- 0.045) mg/g, q15-45 = 6.299, P < 0.05]. In the magnetic targeting group, the concentration of MTX in the right hemisphere was significantly higher than that in the left hemisphere (t45min = 21.135, P = 0.000) but no difference was observed between bilateral hemispheres in the other two groups (non-magnetic targeting group: t45min = 0.434, P = 0.670; control group: t45min = 0.533, P = 0.600). CONCLUSION: In the presence of the external magnetic field, FM-HSA-MTX can distribute successfully in the targeting areas of the brain.

[Effect of intensive insulin therapy on serum proinflammatory cytokine levels in patients with severe trauma].

OBJECTIVE: To investigate the effect of intensive insulin therapy on serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and C reaction protein (CRP), all of which reflected the inflammatory status in patients with severe trauma. METHODS: Forty patients with severe trauma [injury severity score (ISS)>or=20] were randomly divided into intensive insulin therapy group and control group. Enzyme-linked immunoadsorbent assay (ELISA) method was used to determine the TNF-alpha and IL-6 levels within 72 hours after admission. RESULTS: Serum levels of TNF-alpha, IL-6 and CRP in patients received intensive insulin therapy were significantly lower than those in patients without the therapy (P<0.05 or P<0.01). CONCLUSION: Intensive insulin therapy can attenuate the systemic inflammatory response to trauma. The anti-inflammatory actions of insulin, as well as its glycemia controlling effects, might contribute to the improved outcomes of patients with severe trauma.

[A study on detecting specific antibodies of hemorrhagic fever with renal syndrome and treatment with integrated traditional Chinese and western medicine].

OBJECTIVE: To explore a simple speedy specific and sensitive method to detect specific IgM (sIgM) and IgG (sIgG) antibodies of hemorrhagic fever with renal syndrome (HFRS),and to study the therapeutic effects of integrated traditional Chinese and western medicine on HFRS. METHODS: The serum of 559 patients with HFRS were tested with colloidal gold immuno-dot assay (CGIDA) for sIgM and sIgG antibodies and compared with enzyme linked immunosorbent assay (ELISA) or indirect fluorescent antibody test (IFAT). One hundred and one patients with HFRS were randomized into treatment group (n=50),treated with Kuhuang Injection, Shenmai Injection and Huangqi Liquid) and control group (n=51),treated with Ribarvirin and Ganlixin Injection). RESULTS: The positive rate of sIgM detected with CGIDA was 70.8% and the positive rate of sIgG detected with CGIDA was 87.5%. The days for fever decline, symptoms alleviation and sign relief between the treatment group and control group were similar (P>0.05). The days for recovery of kidney function in the control group was less than that in the treatment group (P<0.01). The rate of crossing shock stage in the treatment group was higher than that of the control group (P<0.01). CONCLUSION: CGIDA was more simple, speedy, specific and sensitive than ELISA or IFAT in detecting the sIgM or sIgG antibodies in serum of patients with HFRS. Although the sensitivity of CGIDA was lower than that of ELISA the CGIDA had no false positive reaction the sensitivity of CGIDA was higher than that of IFAT on detecting IgG. The effect of the treatment group was similar to that of the control group. But the crossing shock stage rate in the treatment group was higher than that of the control group while the control group was better than the treatment group in recovering the kidney function.