Novel mutation of SPG4 gene in a Chinese family with hereditary spastic paraplegia: A case report.

BACKGROUND: Hereditary spastic paraplegia (HSP) is a group of neurogenetic diseases of the corticospinal tract, accompanied by distinct spasticity and weakness of the lower extremities. Mutations in the spastic paraplegia type 4 (SPG4) gene, encoding the spastin protein, are the major cause of the disease. This study reported a Chinese family with HSP caused by a novel mutation of the SPG4 gene. CASE SUMMARY: A 44-year-old male was admitted to our hospital for long-term right lower limb weakness, leg stiffness, and unstable walking. His symptoms gradually worsened, while no obvious muscle atrophy in the lower limbs was found. Neurological examinations revealed that the muscle strength of the lower limbs was normal, and knee reflex hyperreflexia and bilateral positive Babinski signs were detected. Members of his family also had the same symptoms. Using mutation analysis, a novel heterozygous duplication mutation, c.1053dupA, p. (Gln352Thrfs*15), was identified in the SPG4 gene in this family. CONCLUSION: A Chinese family with HSP had a novel mutation of the SPG4 gene, which is autosomal dominant and inherited as pure HSP. The age of onset, sex distribution, and clinical manifestations of all existing living patients in this family were analyzed. The findings may extend the current knowledge on the existing mutations in the SPG4 gene.

mTOR-autophagy promotes pulmonary senescence through IMP1 in chronic toxicity of methamphetamine.

It is growingly concerned about methamphetamine (MA)-induced lung toxicity. IMP1 is identified as a key molecule for cell life processes, but the role of IMP1 in MA-induced senescence remains unclear. The purpose of this study was to investigate whether chronic exposure to MA can cause autophagy and senescence of the lungs, whether there are interactions between Mammalian target of rapamycin (mTOR) and IMP1 and whether IMP1 is involved in pulmonary senescence promoted by mTOR-autophagy. The rats were randomly divided into control group and MA group, following by H&E staining, immunohistochemistry staining and Western blot. The alveolar epithelial cells were proceeded by ß-galactosidase staining, cell cycle detection, transfection and co-immunoprecipitation. Long-term exposure to MA led to the thickening of alveolar septum and more compact lungs. MA promoted the conversion of LC3-I to LC3-II and inhibited the activation of mTOR to induce autophagy. Bioinformatics and co-immunoprecipitation results presented the interactions between IMP1 and mTOR. MA induced cell senescence by decreasing IMP1, up-regulating p21 and p53, arresting cell cycle and increasing SA-ß-gal. Overexpression of IMP1 reduced p21 and SA-ß-gal to inhibit the senescence of alveolar epithelial cells. These results demonstrated that mTOR-autophagy promotes pulmonary senescence through IMP1 in chronic toxicity of methamphetamine.

RUNX3-dependent oxidative epithelial-to-mesenchymal transition in methamphetamine-induced chronic lung injury.

Lung toxicity is the main cause of the death from methamphetamine (MA) abuse, but its mechanism has remained unclear. The purpose of our study was to investigate if MA can induce epithelial-to-mesenchymal transition (EMT) and if RUNX3 is involved in oxidative EMT in MA-induced chronic lung injury. The rats were divided into the control group and MA group. Extracted lungs were used for morphological measurements and Western blot. The alveolar epithelial cells were cultured or transfected and then treated with MA or/and N-acetyl cysteine (NAC) followed by flow cytometry, Western blot, and immunohistochemistry. Chronic exposure to MA resulted in the lower growth ratio of weight, increased right ventricular index, thickened alveolar walls, and reduced number of alveolar sacs. Long-term administration with MA caused oxidative stress and pulmonary EMT. NAC increased RUNX3 and alleviated EMT. However, after knockdown of RUNX3, reactive oxygen species (ROS) levels were significantly upregulated, indicating that RUNX3 was closely related to oxidative stress. Knockdown of RUNX3 aggravated MA-induced EMT by activating RUNX3-dependent TGF-ß signaling. Therefore, RUNX3 may be the key to oxidative EMT in methamphetamine-induced chronic lung injury.

Resveratrol protects the integrity of alveolar epithelial barrier via SIRT1/PTEN/p-Akt pathway in methamphetamine-induced chronic lung injury.

OBJECTIVES: SIRT1 is an antioxidative factor, but its mechanism in methamphetamine (MA)-induced lung injury remains unclear. The purpose of this study is to determine whether MA can disrupt the integrity of alveolar epithelial barrier, whether SIRT1 is involved in MA-induced chronic lung injury and whether Resveratrol (Res) can protect the integrity of alveolar epithelial cells by regulating ROS to activate SIRT1/PTEN/p-Akt pathway. MATERIALS AND METHODS: The rats were randomly divided into control group and MA group. Extracted lungs were detected by Western blot, HE staining and immunohistochemistry. The alveolar epithelial cells were treated with MA or/and Res, following by Western blot, LDH leakage assay and flow cytometry. MOE is used for bio-informatics prediction. RESULTS: Chronic exposure to MA can cause slower growth ratio of weight, increased RVI and induced lung injury including the reduced number of alveolar sacs and the thickened alveolar walls. MA-induced apoptosis was associated with SIRT1-related oxidative stress. Res suppressed ROS levels, activated SIRT1, negatively regulated PTEN, phosphorylated Akt, reduced LDH leakage, increased the expression of ZO-1 and E-cadherin and inhibited the apoptosis of alveolar epithelial cells to attenuate MA-induced higher permeability of alveolar epithelium. CONCLUSIONS: MA disrupted the integrity of alveolar epithelial barrier. Res inhibited oxidative stress and reversed MA-induced higher permeability and apoptosis of alveolar epithelium by the activation of SIRT1/PTEN/p-Akt pathway.

Identifying the pulsed neuron networks' structures by a nonlinear Granger causality method.

BACKGROUND: It is a crucial task of brain science researches to explore functional connective maps of Biological Neural Networks (BNN). The maps help to deeply study the dominant relationship between the structures of the BNNs and their network functions. RESULTS: In this study, the ideas of linear Granger causality modeling and causality identification are extended to those of nonlinear Granger causality modeling and network structure identification. We employed Radial Basis Functions to fit the nonlinear multivariate dynamical responses of BNNs with neuronal pulse firing. By introducing the contributions from presynaptic neurons and detecting whether the predictions for postsynaptic neurons' pulse firing signals are improved or not, we can reveal the information flows distribution of BNNs. Thus, the functional connections from presynaptic neurons can be identified from the obtained network information flows. To verify the effectiveness of the proposed method, the Nonlinear Granger Causality Identification Method (NGCIM) is applied to the network structure discovery processes of Spiking Neural Networks (SNN). SNN is a simulation model based on an Integrate-and-Fire mechanism. By network simulations, the multi-channel neuronal pulse sequence data of the SNNs can be used to reversely identify the synaptic connections and strengths of the SNNs. CONCLUSIONS: The identification results show: for 2-6 nodes small-scale neural networks, 20 nodes medium-scale neural networks, and 100 nodes large-scale neural networks, the identification accuracy of NGCIM with the Gaussian kernel function was 100%, 99.64%, 98.64%, 98.37%, 98.31%, 84.87% and 80.56%, respectively. The identification accuracies were significantly higher than those of a traditional Linear Granger Causality Identification Method with the same network sizes. Thus, with an accumulation of the data obtained by the existing measurement methods, such as Electroencephalography, functional Magnetic Resonance Imaging, and Multi-Electrode Array, the NGCIM can be a promising network modeling method to infer the functional connective maps of BNNs.

Chronic toxicity of methamphetamine: Oxidative remodeling of pulmonary arteries.

Methamphetamine (MA) has a high uptake in lung, but the precise mechanism of MA-induced lung toxicity remains unclear. The aim of this study is to investigate the role of MA abuse in remodeling of pulmonary arteries and to explore the possible correlation of the association of the remodeling with the redox imbalance in pulmonary arterial smooth muscle cells (PASMCs). Wistar rats were randomly divided into control group and MA group for the experimental study. We employed H&E staining, western blot, immunofluorescence, knockdown, flow in our experimental approach. Our studies shows that chronic exposure to MA led to weight loss, increased pulmonary arterial pressure, hypertrophy of right ventricle and remodeling of pulmonary arterial wall of rats. Our cell culture study with PASMCs indicates that MA significantly induced the imbalance between proliferation and apoptosis by upregulating the level of PCNA, Bcl-2 and reduction in the expression of BAX and Caspase 3. MA markedly prevented the nuclear translocation of Nrf2 to inhibit antioxidation. The knockdown of Nrf2 expression using siRNA significantly elevated the expression of SOD2/GCS and the production of ROS in PASMCs and even scaled up the amount of PASMCs induced by MA. Linear regression analysis showed that knockdown of Nrf2 promoted the positive correlation of relative ROS level with proliferation of PASMCs. Therefore, chronic exposure to MA induces pulmonary arterial remodeling by Nrf2-mediated imbalance of redox system to aggravate oxidative stress, and Nrf2 is a possible target for the treatment of MA-lung toxicity.

Compound heterozygous mutations in PARK2 causing early-onset Parkinson disease: A case report.

RATIONALE: Parkinson disease (PD) is a complex neurodegenerative movement disorder characterized by resting tremor, muscular rigidity, bradykinesia, and so on. Genetics has been regarded as an important role in the development of PD. PARK2, an autosomal recessive gene, is the most common one referring to early-onset Parkinson disease (EOPD). Strangely, only a single heterozygous mutation in PARK2 was found in a small minority of patients with PD, which has been reported quite rarely and is difficult to explain. PATIENT CONCERNS: We described a case of 36-year-old male patient, complaining of progressive tremor for 10 years. He 1st presented uncontrolled resting tremor of his left arm. Besides, he also had trouble in completing fine motor tasks such as writing and buttoning. Six years later, tremor of the ipsilateral leg gradually occurred. On neurologic examinations, pronounced parkinsonian symptoms were noted, including resting tremor, body bradykinesia, and hypomimia. The positron emission tomography-computed tomography showed the distribution of dopamine transporter in both putamens decreased obviously. No family history was indentified. He came to hospital because his disease aggravated in the past 4 months. DIAGNOSIS: This patient was diagnosed with PD according to the movement disorder society clinical diagnostic criteria for PD. INTERVENTIONS AND OUTCOMES: With regard to the sequencing of this patient, a heterozygous point mutation of G403C in PARK2 was detected, which was inherited from his unaffected mother, leading to an amino acid alternation of glycine to arginine. Furthermore, deletion mutation of exon 6 in PARK2 was also found in this patient, which was inherited from his normal father. He accepted madopar and benzhexol and showed stable efficacy. To our knowledge, it is the 1st case report to explain the synergistic action of both heterozygous pathogenic point mutation in PARK2 and deletion mutation of exon 6 leading to EOPD. LESSONS: Compound heterozygous mutations in PARK2 with point mutation of G403C and deletion mutation of exon 6 might contribute to the development of EOPD.

Concurrence of autophagy with apoptosis in alveolar epithelial cells contributes to chronic pulmonary toxicity induced by methamphetamine.

OBJECTIVES: Methamphetamine (MA) abuse evokes pulmonary toxicity. The aim of our study is to investigate if autophagy is induced by MA and if autophagy-initiated apoptosis in alveolar epithelial cells is involved in MA-induced chronic pulmonary toxicity. MATERIALS AND METHODS: The rats in Control group and MA group were tested by Doppler and HE staining. The alveolar epithelial cells were treated with MA, following by western blot, RT-PCR and immunofluorescence assay. RESULTS: Chronic exposure to MA resulted in lower growth ratio of weight and in higher heart rate and peak blood flow velocity of the main pulmonary artery of rats. MA induced infiltration of inflammatory cells in lungs, more compact lung parenchyma, thickened alveolar septum and reduction in the number of alveolar sacs. In alveolar epithelial cells, the autophagy marker LC3 and per cent of cells containing LC3-positive autophagosome were significantly increased. MA dose dependently suppressed the phosphorylation of mTOR to inactivate mTOR, elicited autophagy regulatory proteins LC3 and Beclin-1, accelerated the transformation from LC3 I to LC3 II and initiated apoptosis by decreasing Bcl-2 and increasing Bax, Bax/Bcl-2 and cleaved Caspase 3. The above results suggest that sustained autophagy was induced by long-term exposure to MA and that the increased Beclin-1 autophagy initiated apoptosis in alveolar epithelial cells. CONCLUSIONS: Concurrence of autophagy with apoptosis in alveolar epithelial cells contributes to chronic pulmonary toxicity induced by MA.

Clinical relevance of lysyl oxidase-like 2 and functional mechanisms in glioma.

INTRODUCTION: Glioma is the most frequent malignancy of the adult central nervous system with high recurrence risk and poor prognosis. Understanding the biological molecular mechanisms involved in glioma progression is critical for studying oncogenic mechanisms and improving prognosis. Lysyl oxidase-like 2 (LOXL2) is a kind of lysyl oxidase catalyzing the formation of peptidyl-lysine residues and promoting intramolecular cross-linking, especially for proteins in extracellular matrix. Our study explored the expression pattern of LOXL2 in glioma for the first time and found that its high expression was associated with larger tumor size and advanced tumor grade (P<0.05). Moreover, univariate and multivariate analyses revealed LOXL2 as a novel independent prognostic factor for the overall survival of glioma patients. METHODS: To evaluate the detailed functional roles of LOXL2, we tested its oncobiology characteristics in U87-MG cells with overexpression and knockdown experiments. RESULTS: Cellular results demonstrated that LOXL2 overexpression enhanced cell proliferation and invasion, while LOXL2-siRNA attenuated cell viability. Furthermore, our data identified the participation of E-cadherin, Snail1, Src, and FAK proteins downstream of LOXL2. Notably, by using immunoprecipitation and mass spectrometry strategies, we initially verified the interaction between LOXL2 and HDAC2, indicating the existence of a protein complex containing LOXL2/Snail1/HDAC2. Additionally, the expression of HDAC2 protein was highly correlated with that of LOXL2 in clinical glioma tissues (P=0.02), further implying the synergic oncogenic roles of these 2 proteins. CONCLUSION: LOXL2 is a promising prognostic biomarker and may be further evaluated as a potential drug target for patients with glioma.

Encephalopathy associated with propofol infusion syndrome: A case report.

INTRODUCTION: Propofol infusion syndrome (PRIS) is a rare but potentially fatal complication of propofol infusion. It is clinically characterized by metabolic acidosis, refractory bradycardia, rhabdomyolysis, renal failure, hyperlipidemia, and hepatomegaly. Brain lesion was only reported once in a pediatric patient. We present the 1st adult case with colon polyp and cancer who was diagnosed with PRIS. Her brain magnetic resonance imaging (MRI) and computed tomography (CT) scans reveal prominent bilateral brain lesions, matching with the proposed pathophysiologic mechanism of the syndrome. The patient received prompt acidosis correction and cardiorespiratory support. At last, she died from refractory circulatory failure. CONCLUSION: It may be necessary to order a prompt neuroimaging examination in patients suspected with PRIS to judge whether brain lesions exist or not.

Unilateral internuclear ophthalmoplegia with upbeat nystagmus from ischemic origin: evidence for the paramedian tract neurons as a vertical neural integrator?

Only a few cases with unilateral internuclear ophthalmoplegia have been reported presenting vertical nystagmus, and few of them provides convincing evidence for the paramedian tract neuron to be a vertical neural integrator. We report a patient who suffered from confined dorsal mid-upper pontine infarction showing unilateral internuclear ophthalmoplegia with upbeat nystagmus in primary position. This case possibly provide evidence that paramedian tract neurons may act as a vertical neural integrator in human.

Local thrombolytic therapy in severe cerebral venous sinus thrombosis during puerperium.

This study is to explore and evaluate the efficacy and safety of local thrombolytic therapy in superior sagittal sinus in patients with severe cerebral venous sinus thrombosis during puerperium, as well as the efficacy and safety of anti-platelet aggregation treatment for preventing recurrence. Twelve patients during postpartum period with cerebral venous sinus thrombosis were received local thrombolytic therapy by placing a micro-catheter at the distal end of superior sagittal sinus from January 2008 to December 2013. All the patients accepted mechanical thrombus maceration before local intrasinus thrombolytic therapy, and were treated with low molecular weight heparin in the acute phase. After local thrombolytic therapy, anti-platelet aggregation treatment was performed for 6 months. Follow-up data included lumber puncture, fundus examination and magnetic resonance venography (MRV) once per half year for 6-70 months. At discharge, the intracranial pressure of 12 patients reduced to below 200 mmH2O. DSA or MRV confirmed that superior sagittal sinus of 9 patients were smooth. The cortex venous and deep venous were recovered to normal. Superior sagittal sinus of 3 patients recanalized partly. Cortex venous and deep venous was compensated. The follow-up study indicated that no thrombosis and new neurological symptoms occurred among all patients. Local thrombolytic treatment is safe and effective in patients with severe cerebral venous sinus thrombosis during puerperium. The collateral circulation compensation is the main recovery factor. And it is also safe and effective for anti-platelet aggregation treatment to prevent recurrence of cerebral venous sinus thrombosis.

Attenuation of Cisplatin-Induced Neurotoxicity by Cyanidin, a Natural Inhibitor of ROS-Mediated Apoptosis in PC12 Cells.

Cisplatin-based chemotherapy in clinic is severely limited by its adverse effect, including neurotoxicity. Oxidative damage contributes to cisplatin-induced neurotoxicity, but the mechanism remains unclearly. Cyanidin, a natural flavonoid compound, exhibits powerful antioxidant activity. Hence, we investigated the protective effects of cyanidin on PC12 cells against cisplatin-induced neurotoxicity and explored the underlying mechanisms. The results showed that cisplatin-induced cytotoxicity was completely reversed by cyanidin through inhibition of PC12 cell apoptosis, as proved by the attenuation of Sub-G1 peak, PARP cleavage, and caspases-3 activation. Mechanistically, cyanidin significantly inhibited reactive oxygen species (ROS)-induced DNA damage in cisplatin-treated PC12 cells. Our findings revealed that cyanidin as an apoptotic inhibitor effectively blocked cisplatin-induced neurotoxicity through inhibition of ROS-mediated DNA damage and apoptosis, predicating its therapeutic potential in prevention of chemotherapy-induced neurotoxicity. Cisplatin caused DNA damage, activated p53, and subsequently induced PC12 cells apoptosis by triggering ROS overproduction. However, cyanidin administration effectively inhibited DNA damage, attenuated p53 phosphorylation, and eventually reversed cisplatin-induced PC12 cell apoptosis through inhibition ROS accumulation.

Pentylenetetrazol-induced seizures are exacerbated by sleep deprivation through orexin receptor-mediated hippocampal cell proliferation.

Sleep deprivation has been shown to be an activator of seizures in clinical and animal studies. Orexin-A was speculated to be involved in the aggravation of seizures by sleep deprivation through the activation of its receptors: orexin-1 and orexin-2 receptor (OX1R and OX2R, respectively). Therefore, we aimed to investigate the effects of pre-treating sleep-deprived Wistar rats with the OX1R or OX2R antagonists, SB334867 (30 nM/kg) or TCS OX2 29 (30 nM/kg), respectively, followed by a convulsive dose of 50 mg/kg pentylenetetrazol administration (seizure induction), on seizure behavior, and hippocampal neurodegeneration and cellular proliferation. Our results revealed that treatment with SB334867 or TCS OX2 29 significantly prolonged the latency and reduced the duration of seizures, while also lowering the mortality rate in sleep-deprived rats exposed to pentylenetetrazol. In addition, SB334867 or TCS OX2 29 reduced the damage to hippocampal CA3 neurons and the number of bromodeoxyuridine-positive cells in the dentate gyrus (particularly in the hilus). Overall, the effect of TCS OX2 29 was greater than that of SB334867. Taken together, these data suggest that OX1R and OX2R antagonists may alleviate the damage of pentylenetetrazol-induced seizures that are exacerbated by sleep deprivation, and furthermore could be associated with a reduction of neuronal damage in the hippocampus and the inhibition of cellular proliferation in the dentate gyrus.

Rho kinase inhibitor fasudil protects against ß-amyloid-induced hippocampal neurodegeneration in rats.

BACKGROUND AND PURPOSE: Alzheimer's disease (AD) is a progressive neurodegenerative disorder, and Aß-induced neuronal damage is the major pathology of AD. There is increasing evidence that neuroinflammation induced by Aß is also involved in the pathogenesis of AD. Fasudil is a Rho kinase inhibitor and has been reported to have neuroprotective effects. In this study, the main purpose is to investigate whether fasudil has beneficial effects on cognitive impairment and neuronal toxicity induced by Aß. METHODS AND RESULTS: In the present study, intracerebroventricular injection of Aß1-42 to rats resulted in marked cognitive impairment, severe neuronal damage, as well as increased IL-1ß, tumor necrosis factor alpha (TNF-α) production, and NF-κB activation. Administration of fasudil significantly ameliorated the spatial learning and memory impairment, attenuated neuronal loss, and neuronal injury induced by Aß1-42 . In addition, fasudil inhibited IL-1ß and TNF-α production and NF-κB activation in the rat brain. CONCLUSIONS: Fasudil can protect against Aß-induced hippocampal neurodegeneration by suppressing inflammatory response, suggesting that fasudil might be a promising agent for the prevention and treatment of inflammation-related diseases, such as AD.

[EEG, CT and MRI findings in hepatic encephalopathy].

OBJECTIVE: To describe the clinical manifestation and the EEG, CT and MRI findings of hepatic encephalopathy (HE). METHODS: The clinical manifestations and the plasma ammonia levels were analyzed in 17 patients with HE, who underwent EEG, CT and MRI examinations. RESULTS: Fifteen patients had abnormal EEG findings characterized by lowered basic rhythm, moderate to high amplitude theta wave activity, and sporadic delta wave and triphasic wave. Fourteen patients had abnormal MRI findings, including increased signal in the bilateral globus pallidus (14/17), putmen(4/17) and tegmentum of the midbrain (7/17) in T1WI without corresponding alterations in the signal intensity in T2WI. T2 FLAIR demonstrated increased signal in the bilateral white matter of the cerebral hemispheres. CT identified no corresponding alterations in the signal intensity. CONCLUSION: Abnormal EEG findings or MR signals in the brain are common in patients with HE. EEG allows detection of abnormal waves, and MRI may help identify such lesions, which all help in the diagnosis of HE.