Motor unit number index in Bell's palsy: A potential electrophysiological biomarker for early evaluation.

INTRODUCTION: Reliable, noninvasive early diagnostics of neuromuscular function in Bell's palsy, which causes facial paralysis and reduced quality of life, remain to be established. Here, we aimed to evaluate the utility of the motor unit number index (MUNIX) for the quantitative electrophysiological assessment of early-stage Bell's palsy, its correlation with clinical assessments, changes following treatment, and association with clinical prognosis. METHODS: MUNIX measures were recorded from the bilateral zygomaticus, orbicularis oculi, and orbicularis oris muscles of 10 healthy individuals and 64 patients with Bell's palsy. The patients were assessed by two specialist neurologists using the House-Brackmann and Sunnybrook Facial Grading Systems. Repeat assessments were performed on 20 patients with Bell's palsy who received treatment. Additionally, the 64 patients were reassessed using clinical scales after a 1-month interval. RESULTS: The MUNIX values of the main affected muscles on the affected side were lower than those on the healthy side in patients with Bell's palsy (p < .05). The MUNIX measurements significantly correlated with the clinical facial nerve palsy scale scores (p < .05). Significant improvements were observed in the MUNIX values on repeat testing following treatment (p < .05). The baseline motor unit size index (the compound muscle action potential amplitude divided by MUNIX) was positively associated with improved clinical presentation after 1 month (p < .05). CONCLUSION: MUNIX can be used as an electrophysiological biomarker for the quantitative assessment of facial nerve palsy and treatment response, and as a prognostic biomarker, in patients with early Bell's palsy, and is recommended as a complement to conventional neurophysiological examinations.

The role of macrophage plasticity in neurodegenerative diseases.

Tissue-resident macrophages and recruited macrophages play pivotal roles in innate immunity and the maintenance of brain homeostasis. Investigating the involvement of these macrophage populations in eliciting pathological changes associated with neurodegenerative diseases has been a focal point of research. Dysregulated states of macrophages can compromise clearance mechanisms for pathological proteins such as amyloid-ß (Aß) in Alzheimer's disease (AD) and TDP-43 in Amyotrophic lateral sclerosis (ALS). Additionally, recent evidence suggests that abnormalities in the peripheral clearance of pathological proteins are implicated in the pathogenesis and progression of neurodegenerative diseases. Furthermore, numerous genome-wide association studies have linked genetic risk factors, which alter the functionality of various immune cells, to the accumulation of pathological proteins. This review aims to unravel the intricacies of macrophage biology in both homeostatic conditions and neurodegenerative disorders. To this end, we initially provide an overview of the modifications in receptor and gene expression observed in diverse macrophage subsets throughout development. Subsequently, we outlined the roles of resident macrophages and recruited macrophages in neurodegenerative diseases and the progress of targeted therapy. Finally, we describe the latest advances in macrophage imaging methods and measurement of inflammation, which may provide information and related treatment strategies that hold promise for informing the design of future investigations and therapeutic interventions.

Characteristics of after-discharges following compound muscle action potential or F-wave in primary peripheral nerve hyperexcitability syndrome.

INTRODUCTION/AIMS: F-wave testing frequently reveals after-discharges of varied morphologies in patients with primary peripheral nerve hyperexcitability syndrome (PNHS), although reports are scant. This study aimed to explore the morphological characteristics of the after-discharges during F-wave tests in PNHS, and to assess the association between after-discharges and the disease classification. METHODS: We conducted a retrospective analysis of patients diagnosed with PNHS between 2014 and 2022. The morphological characteristic and duration of after-discharges during F-wave tests were analyzed. After-discharges in the Morvan syndrome group were compared with those in non-Morvan group, and between groups with positive or negative voltage-gated potassium channel (VGKC) complex antibodies. RESULTS: Twenty-nine patients were included in the study, of which 25 exhibited after-discharges. All after-discharges in Morvan patients occurred following compound muscle action potential (CMAP). In non-Morvan patients, after-discharges occurred following F-wave (32%) and CMAP (47%). The durations of after-discharges following CMAP were significantly prolonged in Morvan (54.2 ± 18.8 ms) compared to non-Morvan patients (34.5 ± 15.0 ms). The majority of antibody-positive patients (18/20) exhibited after-discharges following CMAP, whereas 67% of antibody-negative patients (6/9) showed after-discharges following F-wave. DISCUSSION: The varying presentations of after-discharges, including their location (after CMAP or F-wave) and the duration of after-discharge can assist in clinically classifying PNHS.

Neurological features of Hansen disease: a retrospective, multicenter cohort study.

To elucidate the neurological features of Hansen disease. The medical records of patients with confirmed Hansen disease transferred from the neurology department were reviewed, and all medical and neurological manifestations of Hansen disease were assessed. Eleven patients with confirmed Hansen disease, 10 with newly detected Hansen disease and 1 with relapsed Hansen disease, who visited neurology departments were enrolled. The newly detected patients with Hansen disease were classified as having lepromatous leprosy (LL, n = 1), borderline lepromatous leprosy (BL, n = 2), borderline leprosy (BB, n = 2), borderline tuberculoid leprosy (BT, n = 1), tuberculoid leprosy (TT, n = 2), or pure neural leprosy (PNL, n = 2). All of the patients with confirmed Hansen were diagnosed with peripheral neuropathy (100.00%, 11/11). The symptoms and signs presented were mainly limb numbness (100.00%, 11/11), sensory and motor dysfunction (100.00%, 11/11), decreased muscle strength (90.90%, 10/11), and skin lesions (81.81%, 9/11). Nerve morphological features in nerve ultrasonography (US) included peripheral nerve asymmetry and segmental thickening (100.00%, 9/9). For neuro-electrophysiology feature, the frequency of no response of sensory nerves was significantly higher than those of motor nerves [(51.21% 42/82) vs (24.70%, 21/85)(P = 0.0183*)] by electrodiagnostic (EDX) studies. Nerve histological features in nerve biopsy analysis included demyelination (100.00%, 5/5) and axonal damage (60.00%, 3/5). In addition to confirmed diagnoses by acid-fast bacteria (AFB) staining (54.54%, 6/11) and skin pathology analysis (100.00%, 8/8), serology and molecular technology were positive in 36.36% (4/11) and 100.00% (11/11) of confirmed patients of Hansen disease, respectively. It is not uncommon for patients of Hansen disease to visit neurology departments due to peripheral neuropathy. The main pathological features of affected nerves are demyelination and axonal damage. The combination of nerve US, EDX studies, nerve biopsy, and serological and molecular tests can improve the diagnosis of Hansen disease.

PHPB ameliorates memory deficits and reduces oxidative injury in Alzheimer's disease mouse model by activating Nrf2 signaling pathway.

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is the most common cause of dementia in elderly people and substantially affects patient quality of life. Oxidative stress is considered a key factor in the development of AD. Nrf2 plays a vital role in maintaining redox homeostasis and regulating neuroinflammatory responses in AD. Previous studies show that potassium 2-(1-hydroxypentyl)-benzoate (PHPB) exerts neuroprotective effects against cognitive impairment in a variety of dementia animal models such as APP/PS1 transgenic mice. In this study we investigated whether PHPB ameriorated the progression of AD by reducing oxidative stress (OS) damage. Both 5- and 13-month-old APP/PS1 mice were administered PHPB (100 mg·kg-1·d-1, i.g.) for 10 weeks. After the cognition assessment, the mice were euthanized, and the left hemisphere of the brain was harvested for analyses. We showed that 5-month-old APP/PS1 mice already exhibited impaired performance in the step-down test, and knockdown of Nrf2 gene only slightly increased the impairment, while knockdown of Nrf2 gene in 13-month-old APP/PS1 mice resulted in greatly worse performance. PHPB administration significantly ameliorated the cognition impairments and enhanced antioxidative capacity in APP/PS1 mice. In addition, PHPB administration significantly increased the p-AKT/AKT and p-GSK3ß/GSK3ß ratios and the expression levels of Nrf2, HO-1 and NQO-1 in APP/PS1 mice, but these changes were abolished by knockdown of Nrf2 gene. In SK-N-SH APPwt cells and primary mouse neurons, PHPB (10 µM) significantly increased the p-AKT/AKT and p-GSK3ß/GSK3ß ratios and the level of Nrf2, which were blocked by knockdown of Nrf2 gene. In summary, this study demonstrates that PHPB exerts a protective effect via the Akt/GSK3ß/Nrf2 pathway and it might be a promising neuroprotective agent for the treatment of AD.

Honokiol alleviated neurodegeneration by reducing oxidative stress and improving mitochondrial function in mutant SOD1 cellular and mouse models of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting both upper and lower motor neurons (MNs) with large unmet medical needs. Multiple pathological mechanisms are considered to contribute to the progression of ALS, including neuronal oxidative stress and mitochondrial dysfunction. Honokiol (HNK) has been reported to exert therapeutic effects in several neurologic disease models including ischemia stroke, Alzheimer's disease and Parkinson's disease. Here we found that honokiol also exhibited protective effects in ALS disease models both in vitro and in vivo. Honokiol improved the viability of NSC-34 motor neuron-like cells that expressed the mutant G93A SOD1 proteins (SOD1-G93A cells for short). Mechanistical studies revealed that honokiol alleviated cellular oxidative stress by enhancing glutathione (GSH) synthesis and activating the nuclear factor erythroid 2-related factor 2 (NRF2)-antioxidant response element (ARE) pathway. Also, honokiol improved both mitochondrial function and morphology via fine-tuning mitochondrial dynamics in SOD1-G93A cells. Importantly, honokiol extended the lifespan of the SOD1-G93A transgenic mice and improved the motor function. The improvement of antioxidant capacity and mitochondrial function was further confirmed in the spinal cord and gastrocnemius muscle in mice. Overall, honokiol showed promising preclinical potential as a multiple target drug for ALS treatment.

Case report: Brachial plexopathy caused by malignant peripheral nerve sheath tumor and review of the literature.

Brachial plexopathy (BP) is easily misdiagnosed due to its complexity and varying clinical presentation. Malignant peripheral nerve sheath tumors (MPNST) can accumulate in the brachial plexus and share symptoms with BP, which may hinder the differential diagnosis between BP induced by radiation or metastases, and MPNST-derived BP, in patients with a history of breast cancer and radiation exposure. A 34-year-old Chinese female presented with MPNST. The tumor involved the brachial plexus. She had a history of breast cancer and radiotherapy. The first consideration was radiation- or breast cancer metastasis-derived BP. Clinical examination was performed. Finally, a diagnosis of MPNST of the brachial plexus was made, which guided an accurate treatment plan. This report highlights the importance of correctly diagnosing BP etiology for guiding precise treatment. BP caused by MPNST needs to be considered in clinical practice, and biopsy plays a central role in the differential diagnosis. Complete local surgical resection can prolong survival of patients with MPNST and improve treatment prognosis.

The G41D mutation in SOD1-related amyotrophic lateral sclerosis exhibits phenotypic heterogeneity among individuals: A case report and literature review.

RATIONALE: Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease. However, the misdiagnosis of ALS always occurs because of atypical clinical manifestations. Since mutations in Cu/Zn superoxide dismutase 1 (SOD1) have been implicated as causative and account for 20% of fALS cases, early genetic sequencing of suspected individuals in ALS pedigrees could be helpful. PATIENT CONCERNS: Here we report a Chinese family spanning three generations with fALS. A heterozygous c.125G>A (p.Gly42Asp) missense mutation in exon 2 of SOD1 gene was detected in our proband as well as her 2 siblings and next generation. Phenotypic diversity was also reported among symptomatic individuals. DIAGNOSES: Peripheral blood samples from the proband were collected and sent for polymerase chain reaction (PCR) and Sanger sequencing of the SOD1 gene at Sanvalley Diagnostics. The other 11 members in the studied family then underwent locus verification. INTERVENTIONS: Butylphthalide, Vitamin B12, Coenzyme Q10 and mouse nerve growth factor is given to the symptomatic members. OUTCOMES: The symptoms of our proband was not improved by treatments at a late stage. She passed away the fourth year of the disease due to respiratory failure. Two siblings of the proband were given active treatments once verified as carrier. Their symptoms are still limited to limb weakness. LESSONS: This study suggests genetic sequencing is a powerful tool for the diagnosis of familial ALS. Phenotypic heterogeneity exists among G41D-mutated individuals, which further highlights the importance of genomic strategies for early diagnosis.

ALS-causing SOD1 mutants regulate occludin phosphorylation/ubiquitination and endocytic trafficking via the ITCH/Eps15/Rab5 axis.

It is increasingly recognized that blood-spinal cord barrier (BSCB) breakdown is a hallmark of amyotrophic lateral sclerosis (ALS). BSCB integrity is disrupted prior to disease onset. Occludin, as the functional component of the endothelial barrier, is downregulated in mouse models expressing ALS-linked superoxide dismutase-1 (SOD1) mutants. However, the molecular mechanisms underlying the regulation of occludin expression remain elusive. Here, using SOD1G93A transgenic mice and endothelial cells expressing SOD1 mutants of different biochemical characteristics, we found that the SOD1 mutation disrupted endothelial barrier integrity and that the occludin expression level was downregulated with disease progression. Our mechanistic studies revealed that abnormal reactive oxygen species (ROS) in mutant SOD1-expressing cells induced occludin phosphorylation, which facilitated the subsequent occludin ubiquitination mediated by the E3 ligase ITCH. Moreover, ubiquitinated occludin interacted with Eps15 to initiate its internalization, then trafficked to Rab5-positive vesicles and be degraded by proteasomes, resulting in a reduction in cell surface localization and total abundance. Notably, either ITCH or Eps15 knockdown was sufficient to rescue occludin degradation and ameliorate endothelial barrier disruption. In conclusion, our study reveals a novel mechanism of occludin degradation mediated by ALS-causing SOD1 mutants and demonstrates a role for occludin in regulating BSCB integrity.

In vivo hepatoprotective activity and the underlying mechanism of chebulinic acid from Terminalia chebula fruit.

BACKGROUND: The fruit of Terminalia chebula Retz. is one of the most widely used herbal drug in Traditional medicine prescriptions including those for liver diseases. In the screening of bioactive constituents that have potential hepatoprotective activity, chebulinic acid (CA) which is a major chemical constituent of T. chebula fruit showed potent activity. PURPOSE: This work was conducted to investigate the hepatoprotective activity and mechanisms of CA. METHODS: The hepatoprotective effect of CA was examined on hepatotoxic models of cells, zebrafish larvae and mice caused by tert-butyl hydrogen peroxide (t-BHP), acetaminophen (APAP) and CCl4, respectively. RESULTS: Pretreatment with CA could prevent t-BHP-induced damage in L-02 hepatocytes by blocking the production of ROS, reducing LDH levels and enhancing HO-1 and NQO1 expression via MAPK/Nrf2 signaling pathway. In animal experiments, CA significantly protected mice from CCl4-induced liver injury, as demonstrated by reduced ALT, AST and MDA levels, enhanced SOD activity, improved liver histopathological changes, and the activation of the Nrf2/HO-1 signaling pathway. CA metabolized to chebulic acid isomers with DPPH radical scavenging activity. In a transgenic zebrafish line with liver specific expression of DsRed RFP, CA diminished the hepatotoxicity induced by 10 mM APAP. CONCLUSION: Experiments in cell and two animal models demonstrated consistent results and comprehensively expounded the hepatoprotective effects of CA.

Neuroprotective effects of Hemocoagulase Agkistrodon on experimental traumatic brain injury.

Traumatic brain injury (TBI) is the major cause of disability and mortality among young people and is associated with neurodegenerative diseases. However, the available clinical options have limited effectiveness. Here, we investigated the neuroprotective effect of Hemocoagulase Agkistrodon (HCA), a thrombin-like enzyme (TLE) isolated and purified from snake venom. Rats subjected to experimental TBI were administered a single dose of HCA or vehicle 10 min after injury. Neurological function was assessed with modified neurological severity score (mNSS). Brain edema were evaluated by measuring brain water content. Levels of hemoglobin and inflammatory cytokines were detected by Enzyme-linked immunosorbent assay (ELISA). In addition, assays including Evans blue extravasation, Western blot analysis and immunofluorescence staining were utilized to determined blood-brain barrier (BBB) integrity. Our results showed that HCA treatment ameliorated neurological deficits (p < 0.01), alleviated brain edema (p < 0.01) and hemorrhage (p < 0.01), decreased the production of the proinflammatory cytokines IL-1ß (p < 0.01), TNF-α (p < 0.01) and IL-6 (p < 0.05), and increased the anti-inflammatory cytokine IL-10 at the contusion site (p < 0.01). Moreover, HCA administration reduced BBB disruption by regulating expression of tight junction proteins, including ZO-1, occludin and claudin-5 (ps < 0.01). Together, our results demonstrate that HCA might have therapeutic efficacy in acute TBI, suggesting a potential clinical application for mitigating the neuropathological damage associated with TBI.

Molecular mechanisms of mitophagy and its roles in neurodegenerative diseases.

Neurodegenerative diseases are the most common diseases of the nervous system in elderly people, which are currently incurable and cause great burden to families and societies. Mitochondria are the energy factory of the cell and have extremely important effects on neuronal function. The elimination of dysfunctional mitochondria is essential for the mitochondrial metabolic homeostasis, energy supply, and neuronal survival. Recent studies suggest that the impaired mitophagy may lead to the accumulation of damaged mitochondria and therefore contribute to the progression of neurodegenerative diseases. This review mainly focuses on mitophagy, mitochondrial dynamics, and their abnormal changes in neurodegenerative diseases, as well as the therapeutic strategies targeting mitophagy that have shown promise in recent preclinical and clinical studies.

L-3-n-Butylphthalide improves synaptic and dendritic spine plasticity and ameliorates neurite pathology in Alzheimer's disease mouse model and cultured hippocampal neurons.

Alzheimer's disease (AD) is the most common cause of dementia among elderly people. Despite enormous efforts, the pathogenesis of AD still remains unclear and no drug has yet been proved to be disease-modifying. As the basis of learning and memory, the plasticity of synapse and dendritic spine has been impaired during AD progression. Previous studies have showed a protective effect of L-3-n-butylphthalide (L-NBP) on cognitive deficits in AD, we wonder whether this protective effect is associated with positive alterations on synapse and dendritic spines. In this study, we first of all confirmed the anti-dementia effect of L-NBP in 13-month-old APP/PS1 mice, and then investigated the alterations in synaptic and dendritic spine plasticity due to L-NBP treatment both in vivo and in vitro. We also conducted preliminary studies and found the possible mechanisms related to the inhibition of over-activated complement cascade and the remodeling of actin cytoskeleton. Besides, we also found extra benefits of L-NBP on presynaptic dystrophic neurites and attempted to give explanations from the view of autophagy regulation. Taken together, our study added some new evidence to the application of L-NBP in AD treatment and provided deeper insight into the relevant mechanisms for future study.

The MMP-2/TIMP-2 System in Alzheimer Disease.

Alzheimer Disease (AD) is the most prevalent type of dementia. Pathological changes in the AD brain include Amyloid ß-protein (Aß) plaques and Neurofibrillary Tangles (NFTs), as well as extensive neuronal and synaptic loss. Matrix Metalloproteinase-2 (MMP-2) is a neutral, zinc-dependent protease that primarily targets extracellular matrix proteins. MMP-2 activity is strictly controlled, and its dysregulation has been implicated in a variety of pathologies, including AD. In this brief review, we discussed the contributions of dysregulated MMP-2 activity and an imbalanced interaction between MMP-2 and its endogenous inhibitor, Tissue Inhibitors of Metalloproteinase-2 (TIMP-2), to AD. We also described the underlying mechanisms of the effects of MMP-2/TIMP-2, both beneficial and detrimental, on AD, including: (1) MMP-2 directly degrades Aß resulting in the clearance of Aß deposits. Conversely, Aß-induced MMP-2 may contribute to brain parenchymal destruction. (2) MMP-2 induces breakdown of BBB, and this deleterious effect could be reversed by TIMP-2. (3) MMP-2 disrupts oxidative homeostasis in AD. (4) MMP-2 has both proinflammatory/pro-angiogenetic and antiinflammatory/ anti-angiogenetic effects on AD. Besides, we discuss the clinical utility of MMP- 2/TIMP-2 as therapeutic targets for AD.

Structures and In Vitro Antihepatic Fibrosis Activities of Prenylated Dihydrostilbenes and Flavonoids from Glycyrrhiza uralensis Leaves.

Glycyrrhiza uralensis is the major plant source of licorice. This study was to identify bioactive compounds from the plant's leaves in order to make better use of its aerial part. An ethanol extract of the leaves was subjected to repeated chromatography to yield 15 compounds. The structures were determined to be three novel dihydrostilbenes, based on their various spectroscopic data-glycypytilbene A (1), glycydipytilbene (2), and glycypytilbene B (3)-and 12 known compounds, α,α'-dihydro-3,5,4'-trihydroxy-4,3'-diisopentenylstilbene (4), α,α'-dihydro-3,5,3',4'-tetrahydroxy-2,5'-diisopentenylstilbene (5), 6-prenyleriodictyol (6), 5'-prenyleriodictyol (7), 6-prenylquercetin-3-Me ether (8), 5'-prenylquercetin (9), 6-prenylquercetin (10), 6-prenylnaringenin (11), 3'-prenylnaringenin (12), sigmoidin C (13), 8-[(E)-3-hydroxymethyl-2- butenyl]-eriodictyol (14), and quercetin-3-Me ether (15). Most of these chemical constituents inhibited α-glucosidase activity, with the two prenylated quercetin derivatives (9 to 10) being the greatest active (IC50 < 4.0 µg/mL). Compounds 1, 3 to 4, 6 to 7, 9 to 12 impeded the growth of human hepatic stellate cells, with the prenylated flavonoids (6 to 7, 9 to 12) being more robust than their unprenylated counterparts. PRACTICAL APPLICATIONS: This study found that Glycyrrhiza uralensis leaves contain prenylated dihydrostilbenes and flavonoids with inhibiting effects on α-glucosidase and on the proliferation of human hepatic stellate cells, which should prompt the development of G. uralensis leaves for healthy products with anti-diabetic or liver fibrosis-preventing effects.

Immune cell distribution and immunoglobulin levels change following sciatic nerve injury in a rat model.

OBJECTIVES: To investigate the systemic and local immune status of two surgical rat models of sciatic nerve injury, a crushed sciatic nerve, and a sciatic nerve transection. MATERIALS AND METHODS: Twenty-four adult male Sprague-Dawley rats were randomly divided into three groups: sham-operation (control group), sciatic nerve crush, and sciatic nerve transaction. Sciatic nerve surgery was performed. The percentage of CD4(+) cells and the CD4(+)/CD8+ratio were determined by flow cytometry. Serum IgM and IgG levels were analyzed by ELISA. T-cells (CD3) and macrophages (CD68) in sciatic nerve tissue sections were identified through immunohistochemistry. RESULTS: Compared to sham-operated controls, in rats that underwent nerve injury, the percentage of CD4(+) cells and the CD4(+)/CD8(+) ratio in the peripheral blood were significantly decreased 7 days after surgery, serum IgM levels were increased 14 days after surgery, and serum IgG levels were increased 21 days after surgery. There were a large number of CD3(+) cells and a small number of CD68(+) cells in sciatic nerve tissue sections 21 days after surgery, indicating T-cell and macrophage activation and infiltration. Local IgG deposition was also detected at the nerve injury site 21 days after surgery. CONCLUSION: Rat humoral and cellular immune status changed following sciatic nerve injury, particularly with regard to the cellular immune response at the nerve injury site.

Dexamethasone enhanced functional recovery after sciatic nerve crush injury in rats.

Dexamethasone is currently used for the treatment of peripheral nerve injury, but its mechanisms of action are not completely understood. Inflammation/immune response at the site of nerve lesion is known to be an essential trigger of the pathological changes that have a critical impact on nerve repair and regeneration. In this study, we observed the effects of various doses of dexamethasone on the functional recovery after sciatic nerve crush injury in a rat model. Motor functional recovery was monitored by walking track analysis and gastrocnemius muscle mass ratio. The myelinated axon number was counted by morphometric analysis. Rats administered dexamethasone by local intramuscular injection had a higher nerve function index value, increased gastrocnemius muscle mass ratio, reduced Wallerian degeneration severity, and enhanced regenerated myelinated nerve fibers. Immunohistochemical analysis was performed for CD3 expression, which is a marker for T-cell activation, and infiltration in the sciatic nerve. Dexamethasone-injected rats had fewer CD3-positive cells compared to controls. Furthermore, we found increased expression of GAP-43, which is a factor associated with development and plasticity of the nervous system, in rat nerves receiving dexamethasone. These results provide strong evidence that dexamethasone enhances sciatic nerve regeneration and function recovery in a rat model of sciatic nerve injury through immunosuppressive and potential neurotrophic effects.

Therapeutic effects of dl-3-n-butylphthalide in a transgenic mouse model of amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive death of the upper and lower motor neurons. Transgenic mice over-expressing a mutant form of the human SOD1 gene develop an ALS-like phenotype. Currently, there is no effective treatment or drug for the fatal disease. Previous studies reported potent efficacy of dl-3-n-butylphthalide (DL-NBP) for several neurodegenerative disorders and cerebral ischemia. SOD1-G93A mice are a mouse model of ALS. In this study, we investigated the efficacy of DL-NBP on this ALS mouse model. METHODS: Sixty SOD1-G93A female mice were divided into four groups. The vehicle control group received 0 mg×kg(-1)×d(-1) DL-NBP. The experimental groups received DL-NBP with doses of 30, 60 or 120 mg×kg(-1)×d(-1), respectively. For measurement of motor activity, the hanging wire test and rotarod test were performed. Survival statistics were analyzed by Kaplan-Meier survival curves. The body weight of each mouse was recorded twice per week. The statistical motor unit number estimation (MUNE) technique was used to estimate the number of functioning motor units in gastrocnemius muscle. Muscle morphology was evaluated by hematoxylin and eosin staining. Motor neuron quantitation was performed by Nissl staining and microglia activation was observed by immunohistochemistry. RESULTS: Oral administration of 60 mg×kg(-1)×d(-1)1 DL-NBP significantly prolonged survival ((164.78 ± 16.67) days) of SOD1-G93A mice compared with vehicle control ((140.00 ± 16.89) days). Treating mice with DL-NBP (60 mg×kg(-1)×d(-1)) significantly decreased the progression rate of motor deficits and suppressed body weight reduction. Furthermore, we found that treating SOD1-G93A mice with DL-NBP (60 mg×kg(-1)×d(-1)) slowed the rate of MUNE reduction (P < 0.01). Motor neurons were remarkably preserved in the anterior horns in mice treated with DL-NBP (60 mg×kg(-1)×d(-1)) at the stage of 19 weeks (P < 0.01). Treating mice with DL-NBP (60 mg×kg(-1)×d(-1)) significantly reduced CD11b immunoreactivity compared with vehicle control mice (P < 0.05). No significant effect was observed in mice treated with DL-NBP of 30 or 120 mg×kg(-1)×d(-1). CONCLUSIONS: The post-disease-onset administration of DL-NBP significantly prolonged survival and improved motor performance in SOD1-G93A mice. DL-NBP may be a potential therapeutic agent for ALS.

DL-3-n-butylphthalide extends survival by attenuating glial activation in a mouse model of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative disease characterized by progressive muscular atrophy, paralysis and bulbar symptoms. Transgenic mice over-expressing human mutant Cu/Zn superoxide dismutase-1 (SOD1) mimicked the pathological phenotype of ALS. dl-3-n-butylphthalide (dl-NBP) has been demonstrated to play a neuroprotective role in cerebral ischemia, vascular dementia, and Alzheimer's disease. In the current study, we examined the effect of dl-NBP in Tg (SOD1-G93A) transgenic mice, a well-studied model of ALS. Following the symptomatic onset of disease, oral administration of dl-NBP significantly improved motor performance, extended the survival interval, attenuated motor neuron loss, and delayed motor unit reduction compared to vehicle controls. These observations were further corroborated by the significant reduction in immunoreactivity of CD11b and glial fibrillary acidic protein (GFAP), markers for microglia and astrocytes, respectively. Additionally, downregulation of nuclear factor κB (NF-κB) p65 and tumor necrosis factor-α (TNF-α) protein levels and a slight upregulation of NF-E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were found in the spinal cord of Tg (SOD1-G93A) mice treated by dl-NBP. These results suggest that dl-NBP might be a promising compound in the treatment of ALS. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.