Blocking the EGFR/p38/NF-κB signaling pathway alleviates disruption of BSCB and subsequent inflammation after spinal cord injury.

Epidermal growth factor receptor (EGFR) activation is involved in blood spinal cord barrier (BSCB) disruption and secondary injury after spinal cord injury (SCI). However, the underlying mechanisms of EGFR activation mediating BSCB disruption and secondary injury after SCI remain unclear. An in vitro model of oxygen and glucose deprivation/reoxygenation (OGD/R) induced BSCB damage and in vivo rat SCI model were employed to define the role of EGFR/p38/NF-κB signal pathway activation and its induced inflammatory injury in main cellular components of BSCB. Genetic regulation (lentivirus delivered shRNA and overexpression system) or chemical intervention (agonist or inhibitor) were applied to activate or inactivate EGFR and p38 in astrocytes and microvascular endothelial cells (MEC) under which conditions, the expression of pro-inflammatory factors (TNF-α, iNOS, COX-2, and IL-1ß), tight junction (TJ) protein (ZO-1 and occludin), nuclear translocation of NF-κB and permeability of BSCB were analyzed. The pEGFR was increased in astrocytes and MEC which induced the activation of EGFR and p38 and NF-κB nuclear translocation. The activation of EGFR and p38 increased the TNF-α, iNOS, COX-2, and IL-1ß responsible for the inflammatory injury and reduced the ZO-1 and occludin which caused BSCB disruption. While EGFR or p38 inactivation inhibited NF-κB nuclear translocation, and markedly attenuated the production of pro-inflammatory factors and the loss of TJ protein. This study suggests that the EGFR activation in main cellular components of BSCB after SCI mediates BSCB disruption and secondary inflammatory injury via the EGFR/p38/NF-κB pathway.

Case Report: Anti-NMDAR Encephalitis With Anti-MOG CNS Demyelination After Recurrent CNS Demyelination.

Introduction: Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, a serious neurological autoimmune disorder caused by autoantibodies with diverse clinical manifestations, may simultaneously onset with antimyelin oligodendrocyte glycoprotein (MOG) demyelination after recurrent central nervous system (CNS) demyelination. Case Report: We present a case of anti-NMDAR encephalitis combining with anti-MOG CNS demyelination following recurrent CNS demyelination. A 38-year-old man admitted to hospital developed epileptic seizures following recurrent episodes of cross-sensory disturbance and dizziness. Magnetic resonance imaging (MRI) showed a demyelinating lesion in the right brainstem initially. Despite a good response to methylprednisolone pulse therapy at the beginning, the patient still had relapses and progression after corticosteroid reduction or withdrawal. Then brain MRI discovered new serpentine lesions involving extensive cerebral cortex on his second relapse. Repeat autoantibodies test indicated cerebrospinal fluid (CSF) NMDAR antibodies coexisted with MOG-Abs simultaneously, suggesting the diagnosis of anti-NMDAR encephalitis with anti-MOG CNS demyelination. Results: After a definite diagnosis, the patient was treated with mycophenolate mofetil (MMF) and corticosteroid. He was discharged after his symptoms ameliorated. No neurological sequels remained, and there were no effects on his activities of daily living after 6 months of immunoregulatory therapy of MMF and corticosteroid. Conclusion: For individuals with recurrent CNS demyelination, especially combining with cortical encephalitis, repeated detection of autoantibodies against AE, and demyelination in CSF/serum can be helpful to enable a definite early diagnosis. For patients who suffer from anti-NMDAR encephalitis combining with anti-MOG CNS demyelination, second-line immunotherapy is recommended when first-line treatment such as steroids, intravenous immunoglobulin G (IVIG) and plasma exchange has been proven ineffective to prevent the relapse of disease.

Ningdong Granule Upregulates the Striatal DA Transporter and Attenuates Stereotyped Behavior of Tourette Syndrome in Rats.

This study aimed to evaluate the possible mechanism of Ningdong granule (NDG) for the treatment of Tourette syndrome (TS). The rats with stereotyped behavior were established by microinjection with TS patients' sera; then, the model rats were divided into NDG and haloperidol (Hal) group, and the nonmedication model rats were regarded as treatment control (TS group). The stereotyped behavior of the rats was recorded, the level of dopamine (DA) in striatum, and the content of homovanillic acid (HVA) in sera were tested, and dopamine transporter (DAT) expression was measured in the study. The experimental results showed that NDG effectively inhibited the stereotyped behavior (P < 0.01), decreased the levels of DA in the striatum (P < 0.05), increased the content of sera HVA (P < 0.01), and enhanced the protein and mRNA expression of DAT in the striatum (P < 0.01). Additionally, the results also revealed Hal could improve the stereotyped behavior as well but had no remarkable influence on DAT expression and DA metabolism. In conclusion, NDG attenuates stereotyped behavior, and its mechanism of action might be associated with the upregulation of DAT expression to regulate DA metabolism in the brain.

Myasthenia gravis and specific immunotherapy: monoclonal antibodies.

Myasthenia gravis (MG) is an acquired autoimmune disease affecting the postsynaptic membrane of neuromuscular junctions and characterized by antibody-mediated T cell dependence and complement involvement. Cholinesterase inhibitors (e.g., pyridostigmine bromide), glucocorticoids, and azathioprine are currently recommended as first-line treatments for MG, though they have limitations, including potential toxicity and ineffectiveness in patients with refractory MG. In recent years, owing to an increasing understanding of MG pathogenesis the development and execution of clinical trials with novel biologics, including monoclonal antibodies (mAbs) that have demonstrated higher safety and more specificity, provide new opportunities for the treatment of MG. In this article, we review recent advances in MG pathogenesis and the mAbs that have been used for target-specific MG therapy.

The microenvironment following oxygen glucose deprivation/re-oxygenation-induced BSCB damage in vitro.

OBJECTIVE: To characterize the microenvironment following blood-spinal cord barrier (BSCB) damage and to evaluate the role of BSCB disruption in secondary damage of spinal cord injury (SCI). METHODS: A model of BSCB damage was established by co-culture of primary microvascular endothelial cells and glial cells obtained from rat spinal cord tissue followed by oxygen glucose deprivation/re-oxygenation (OGD/R). Permeability was evaluated by measuring the transendothelial electrical resistance (TEER) and the leakage test of Fluorescein isothiocyanate-dextran (FITC-dextran). The expression of tight junction (TJ) proteins (occludin and zonula occludens-1 (ZO-1) were evaluated by Western blot and immunofluorescence microscopy. Proinflammatory factors (TNF-α, iNOS, COX-2 and IL-1ß), leukocyte chemotactic factors (MIP-1α, MIP-1ß) and leukocyte adhesion factors (ICAM-1, VCAM-1) were detected in the culture medium under different conditions by enzyme-linked immuno sorbent assay (ELISA). RESULTS: The model of BSCB damage induced by OGD/R was successfully constructed. The maximum BSCB permeability occurred 6-12 hours but not within the first 3 h after OGD/R-induced damage. Likewise, the most significant period of TJ protein loss was also detected 6-12 hours after induction. During the hyper-acute period (3 h) following OGD/R-induced damage of BSCB, leukocyte chemotactic factors and leukocyte adhesion factors were significantly increased in the BSCB model. Pro-inflammation factors (TNF-α, IL-1ß, iNOS, COX-2), leukocyte chemotactic factors (MIP-1α, MIP-1ß) and leukocyte adhesion factors (ICAM-1, VCAM-1) were also sharply produced during the acute period (3-6 hours) and maintained plateau levels 6-12 hours following OGD/R-induced damage, which overlapped with the period of BSCB permeability maximum. A negative linear correlation was observed between the abundance of proinflammatory factors and the expression of TJ proteins (ZO-1 and occludin) and transepithelial electrical resistance (TEER), and a positive linear correlation was found with transendothelial FITC-dextran. CONCLUSIONS: Secondary damage continues after primary BSCB damage induced by OGD/R, exhibiting close ties with inflammation injury.

The characteristics of cognitive impairment in subjective chronic tinnitus.

Introduction: Subjective chronic tinnitus is a common medical syndrome with a high frequency of cognitive impairment; however, the characteristics of cognitive impairment in chronic tinnitus are poorly understood. Investigating the scope of cognitive impairment across the severity spectrum of tinnitus patients may shed light on the issue. Methods: A consecutive series of 207 subjective chronic tinnitus patients were classified into mild tinnitus group (n = 95) and severe tinnitus group (n = 112) by THI score (the cutoff THI scores were 37/38). These patients were assessed using the Cognitive Abilities Screening Instrument (CASI) and P300 event-related potential. Results: Although pure tone averages were not different between mild or severe tinnitus patients, severe tinnitus patients scored lower on the CASI assessment as well as almost all subdomains of CASI, particularly in items such as "short-term memory," "concentration or mental manipulation," "orientation," "abstraction and judgment," "language abilities," and "visual construction." Furthermore, compared to mild tinnitus patients, severe tinnitus patients exhibited longer N2 and P3 latencies. Finally, a correlation analysis revealed that tinnitus severity was negatively correlated with CASI score and positively correlated with N2 and P3 latencies. Conclusions: This study reveals that tinnitus patients on the severe end of the spectrum may be at risk for serious cognitive deficits, which may not be a secondary response to disease manifestations but a primary feature of the underlying disease.

Epidermal growth factor receptor inhibitor ameliorates excessive astrogliosis and improves the regeneration microenvironment and functional recovery in adult rats following spinal cord injury.

BACKGROUND: Astrogliosis is a common phenomenon after spinal cord injury (SCI). Although this process exerts positive effects on axonal regeneration, excessive astrogliosis imparts negative effects on neuronal repair and recovery. Epidermal growth factor receptor (EGFR) pathway is critical to the regulation of reactive astrogliosis, and therefore is a potential target of therapeutics to better control the response. In this report, we aim to investigate whether blocking EGFR signaling using an EGFR tyrosine kinase specific inhibitor can attenuate reactive astrogliosis and promote functional recovery after a traumatic SCI. METHOD: The astrocyte scratch injury model in vitro and the weight-drop SCI model in vivo were used as model systems. PD168393 was used to inhibit EGFR signaling activation. Astrocytic activation and phosphorylated EGFR (pEGFR) were observed after immunofluorescence staining and Western blot analysis. The rate of proliferation was determined by immunofluorescence detection of BrdU-incorporating cells located next to the wound. The levels of TNF-α, iNOS, COX-2 and IL-1ß in the culture medium under different conditions were assayed by ELISA. Western blot was performed to semi-quantify the expression of EGFR/pEGFR, glial fibrillary acid protein (GFAP) and chondroitin sulfate proteoglycans (CSPGs). Myelin was stained by Luxol Fast Blue Staining. Cresyl violet eosin staining was performed to analyze the lesion cavity volume and neuronal survival following injury. Finally, functional scoring and residual urine recording were performed to show the rats' recovery. RESULTS: EGFR phosphorylation was found to parallel astrocyte activation, and EGFR inhibitor PD168393 potently inhibited scratch-induced reactive astrogliosis and proinflammatory cytokine/mediator secretion of reactive astrocytes in vitro. Moreover, local administration of PD168393 in the injured area suppressed CSPGs production and glial scar formation, and resulted in reduced demyelination and neuronal loss, which correlated with remarkable hindlimb motor function and bladder improvement in SCI rats. CONCLUSIONS: The specific EGFR inhibitor PD168393 can ameliorate excessive reactive astrogliosis and facilitate a more favorable environment for axonal regeneration after SCI. As such, EGFR inhibitor may be a promising therapeutic intervention in CNS injury.

Inhibiting epidermal growth factor receptor attenuates reactive astrogliosis and improves functional outcome after spinal cord injury in rats.

As a physical barrier to regenerating axons, reactive astrogliosis is also a biochemical barrier which can secrete inhibitory molecules, including chondroitin sulfate proteoglycans (CSPGs) in the pathological mechanism of spinal cord injury (SCI). Thus, inhibition of astroglial proliferation and CSPG production might facilitate axonal regeneration after SCI. Recent studies have demonstrated that epidermal growth factor receptor (EGFR) activation triggers quiescent astrocytes into becoming reactive astrocytes and forming glial scar after CNS injury. In the present study, we investigated whether a specific EGFR inhibitor (AG1478) could attenuate the reactive astrogliosis and production of CSPGs, alleviate demyelination, and eventually enhance the functional recovery after SCI in rats. Our results showed that pEGFR immunoreactivity was up-regulated significantly post injury, mainly confined to astrocytes. Meanwhile, astrocytes near the injury site after SCI became activated obviously characterized by hypertrophic morphology and enhanced GFAP expression. However, administration of AG1478 remarkably reduced trauma induced-reactive astrogliosis and accumulation of CSPGs. Furthermore, the treatment with AG1478 also alleviated demyelination, increased expression of growth-associated proteins-43 (GAP-43) and improved hindlimb function after SCI. Therefore, the local blockade of EGFR in an injured area is beneficial to functional outcome by facilitating a more favorable environment for axonal regeneration in SCI rats.

Ningdong granule: a complementary and alternative therapy in the treatment of attention deficit/hyperactivity disorder.

BACKGROUND: Attention deficit/hyperactivity disorder (ADHD) is a common neurobehavioral and neuropsychiatric disorder in school-age children, and recent studies provide evidence implicating the metabolic abnormalities of dopamine (DA) for its pathophysiology. Methylphenidate, a kind of psychostimulant, is widely used in the treatment of ADHD, but some patients do not respond to it or cannot bear its side effects. As a traditional Chinese medicine preparation, Ningdong granule (NDG) has been used in the treatment of ADHD for several years in China. However, a systematical pharmacological study on its safety and mechanism still remains obscure. OBJECTIVE: This paper aims to evaluate the efficiency, safety, and possible mechanism of NDG on ADHD children compared to methylphenidate. METHODS: Seventy-two ADHD children were recruited to perform an 8-week, randomized, methylphenidate-controlled, doubled-blinded trial. The subjects were equally assigned to two groups receiving either NDG 5 mg/kg/day or methylphenidate 1 mg/kg/day for 8 weeks. The efficiency was assessed by the Teacher and Parent ADHD Rating Scales every 2 weeks for a total of 8 weeks. The side effects were recorded during the study. Blood, urine, and stool routine samples, liver and renal function test, and DA and homovanillic acid (HVA) concentration in sera were tested at the beginning and end of the trial. RESULTS: NDG ameliorated ADHD symptoms after an 8-week medication with fewer side effects compared to methylphenidate (P < 0.05). The result also showed NDG to be safe and tolerable for ADHD children as monitored by the blood, urine, and stool analysis and liver and renal function for 8 weeks (P < 0.05). Moreover, the level of HVA in sera increased in NDG-treated group (P < 0.05), while the content of DA had no significant change during the study. An analysis of Pearson correlation coefficients also showed that the increased content of HVA in sera was associated with the improved scores of Teacher and Parent ADHD Rating Scales. CONCLUSIONS: Compared to methylphenidate, NDG is effective and safe for ADHD children in the short term, increases the HVA concentration in sera to regulate DA metabolism, and promises to be an alternative medication, safely and effectively.

Characteristics of depressive symptoms in essential tremor.

Depressive symptoms are common in essential tremor (ET) and may be a primary feature of the underlying disease. However, it is still unclear whether depression in ET and depression in primary affective disorders share common clinical manifestations. Sixty-one depressed ET patients and 112 depressed patients without ET were assessed using the Montgomery-Asberg Depression Rating Scale (MADRS). We compared the individual depressive symptoms of the two groups by comparing MADRS subitem scores. Although there was no significant difference between the level of cognitive function and the severity of depression, patients with ET had a lower score on items "reported sadness", "inability to feel" and "pessimistic thoughts", and a higher score on items "concentration difficulties" and "lassitude" than those of patients without ET. These results show that depressive symptoms in patients with ET possess distinct characteristics compared to those in depressed patients without ET.

In vitro evaluation of the compatibility of a novel collagen-heparan sulfate biological scaffold with olfactory ensheathing cells.

BACKGROUND: Stroke and traumatic injury to the nerve system may trigger axonal destruction and the formation of scar tissue, cystic cavitations and physical gaps. Olfactory ensheathing cells (OECs) can secrete neurotrophic factors to promote neurite growth and thus act as a prime candidate for autologous transplantation. Biological scaffolds can provide a robust delivery vehicle to injured nerve tissue for neural cell transplantation strategies, owing to the porous three-dimensional structures (3D). So transplantation of the purposeful cells seeded scaffolds may be a promising method for nerve tissue repair. This study aimed to evaluate the compatibility of a novel collagen-heparan sulfate biological scaffold with olfactory ensheathing cells in vitro. METHODS: Collagen-heparan sulfate (CHS) biological scaffolds were made, and then the scaffolds and OECs were co-cultured in vitro. The viability of OECs was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay at days 1, 3, 5 and 7. Statistical analysis was evaluated by student's t test. Significance was accepted at P < 0.05. OECs were labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE), and the CFSE-labeled OECs were seeded into CHS scaffolds. The attachment and growth of OECs in CHS scaffolds were observed and traced directly by fluorescent microscopy and environmental scanning electron microscope (ESEM). RESULTS: CHS biological scaffolds had steady porous 3D structures and no cytotoxicity to OECs (F = 0.14, P = 0.9330). CHS biological scaffolds were good bridging materials for OECs attachment and proliferation, and they promoted the axonal growth. CONCLUSION: The compatibility of CHS biological scaffolds with OECs is pretty good and CHS biological scaffold is a promising cell carrier for the implantation of OECs in nerve tissue bioengineering.

Combined transplantation of neural stem cells and olfactory ensheathing cells improves the motor function of rats with intracerebral hemorrhage.

OBJECTIVE: To investigate the effects of combined transplantation of neural stem cells (NSC) and olfactory ensheathing cells (OEC) on the motor function of rats with intracerebral hemorrhage. METHODS: In three days after a rat model of caudate nucleus hemorrhage was established, NSCs and OEC, NSC, OEC (from embryos of Wistar rats) or normal saline were injected into hematomas of rats in combined transplantation group, NSC group, OEC group, and control group, respectively. Damage of neural function was scored before and in 3, 7, 14, 30 days after operation. Tissue after transplantation was observed by immunocytochemistry staining. RESULTS: The scores for the NSC, OEC and co-transplantation groups were significantly lower in 14 and 30 days after operation than in 3 days after operation (P < 0.05). The scores for the NSC and OEC groups were significantly lower than those for the control group only in 30 days after operation (P < 0.05), while the difference for the NSC-OEC group was significant in 14 days after operation (P < 0.05). Immunocytochemistry staining revealed that the transplanted OEC and NSC could survive, migrate and differentiate into neurons, astrocytes, and oligodendrocytes. The number of neural precursor cells was greater in the NSC and combined transplantation groups than in the control group. The number of neurons differentiated from NSC was significantly greater in the co-transplantation group than in the NSC group. CONCLUSION: Co-transplantation of NSC and OEC can promote the repair of injured tissue and improve the motor function of rats with intracerebral hemorrhage.

Tamoxifen alleviates irradiation-induced brain injury by attenuating microglial inflammatory response in vitro and in vivo.

Irradiation-induced brain injury, leading to cognitive impairment several months to years after whole brain irradiation (WBI) therapy, is a common health problem in patients with primary or metastatic brain tumor and greatly impairs quality of life for tumor survivors. Recently, it has been demonstrated that a rapid and sustained increase in activated microglia following WBI led to a chronic inflammatory response and a corresponding decrease in hippocampal neurogenesis. Tamoxifen, serving as a radiosensitizer and a useful agent in combination therapy of glioma, has been found to exert anti-inflammatory response both in cultured microglial cells and in a spinal cord injury model. In the present study, we investigated whether tamoxifen alleviated inflammatory damage seen in the irradiated microglia in vitro and in the irradiated brain. Irradiating BV-2 cells (a murine microglial cell line) with various radiation doses (2-10 Gy) led to the increase in IL-1 beta and TNF-alpha expression determined by ELISA, and the conditioned culture medium of irradiated microglia with 10 Gy radiation dose initiated astroglial activation and decreased the number of neuronal cells in vitro. Incubation BV-2 cells with tamoxifen (1 microM) for 45 min significantly inhibited the radiation-induced microglial inflammatory response. In the irradiated brain, WBI induced the breakdown of the blood-brain barrier permeability at day 1 post irradiation and tissue edema formation at day 3 post-radiation. Furthermore, WBI led to microglial activation and reactive astrogliosis in the cerebral cortex and neuronal apoptosis in the CA1 hippocampus at day 3 post-radiation. Tamoxifen administration (i.p., 5 mg/kg) immediately post radiation reduced the irradiation-induced brain damage after WBI. Taken together, these data support that tamoxifen can decrease the irradiation-induced brain damage via attenuating the microglial inflammatory response.