Association Between Serum Neurofilament Light Chain and Neurochemistry Deficits in Patients with Spinocerebellar Ataxia Type 3.

Extensive evidence supports the claim that the serum neurofilament light chain (sNfL) can be used as a biomarker to monitor disease severity in patients with spinocerebellar ataxia type 3 (SCA3). However, little is known about the associations between sNfL levels and neurochemical alterations in SCA3 patients. In this study, we performed a cross-sectional study to analyze the association between sNfL and brain metabolic changes in SCA3 patients. The severity of ataxia was assessed by using the Scale for the Assessment and Rating of Ataxia (SARA) and the International Cooperative Ataxia Rating Scale (ICARS). The sNfL levels and brain metabolic changes, represented by N-acetyl aspartate (NAA)/creatine (Cr) and choline complex (Cho)/Cr ratios, were measured by a single-molecule array and proton magnetic resonance spectroscopy, respectively. In this cohort, we observed consistently elevated sNfL levels and reduced brain metabolites in the cerebellar hemispheres, dentate nucleus, and cerebellar vermis. However, this correlation was further validated in the cerebellar cortex after analysis using pairwise comparisons and a Bonferroni correction. Taken together, our results further confirmed that sNfL levels were increased in SCA3 patients and were negatively correlated with metabolic changes in the cerebellar cortex. Our data also support the idea that sNfL levels are a promising potential complementary biomarker for patients with SCA3.

Effectiveness of High-Frequency Repetitive Transcranial Magnetic Stimulation in Patients With Spinocerebellar Ataxia Type 3.

OBJECTIVE: To investigate the effectiveness of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) on improvement of clinical symptoms in patients with spinocerebellar ataxia type 3 (SCA3). METHODS: Sixteen SCA3 participants diagnosed by genetic testing were enrolled in this sham-controlled and double-blind trial. They received either a 2-week 10-Hz rTMS intervention or sham stimulation targeting the vermis and cerebellum. The Scale for Assessment and Rating of Ataxia and the International Cooperative Ataxia Rating Scale were completed at baseline and poststimulation. RESULTS: Compared with baseline, the HF-rTMS group demonstrated a significant improvement in the total Scale for Assessment and Rating of Ataxia ( P < 0.0001) and the International Cooperative Ataxia Rating Scale scores ( P = 0.002). After 2-week treatment, the real group exhibited decreasing pattern in 3 subgroups, especially for limb kinetic function ( P < 0.0001). CONCLUSIONS: Short-term HF-rTMS treatment is a potentially promising and feasible tool for rehabilitation in patients with SCA3. Studies with long-term follow-up need to be carried out in the future and further need to assess gait, limb kinetic function, speech and oculomotor disorders.

mRNA translation in astrocytes controls hippocampal long-term synaptic plasticity and memory.

Activation of neuronal protein synthesis upon learning is critical for the formation of long-term memory. Here, we report that learning in the contextual fear conditioning paradigm engenders a decrease in eIF2α (eukaryotic translation initiation factor 2) phosphorylation in astrocytes in the hippocampal CA1 region, which promotes protein synthesis. Genetic reduction of eIF2α phosphorylation in hippocampal astrocytes enhanced contextual and spatial memory and lowered the threshold for the induction of long-lasting plasticity by modulating synaptic transmission. Thus, learning-induced dephosphorylation of eIF2α in astrocytes bolsters hippocampal synaptic plasticity and consolidation of long-term memories.

4E-BP2-dependent translation in parvalbumin neurons controls epileptic seizure threshold.

The mechanistic/mammalian target of rapamycin complex 1 (mTORC1) integrates multiple signals to regulate critical cellular processes such as mRNA translation, lipid biogenesis, and autophagy. Germline and somatic mutations in mTOR and genes upstream of mTORC1, such as PTEN, TSC1/2, AKT3, PIK3CA, and components of GATOR1 and KICSTOR complexes, are associated with various epileptic disorders. Increased mTORC1 activity is linked to the pathophysiology of epilepsy in both humans and animal models, and mTORC1 inhibition suppresses epileptogenesis in humans with tuberous sclerosis and animal models with elevated mTORC1 activity. However, the role of mTORC1-dependent translation and the neuronal cell types mediating the effect of enhanced mTORC1 activity in seizures remain unknown. The eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) and 2 (4E-BP2) are translational repressors downstream of mTORC1. Here we show that the ablation of 4E-BP2, but not 4E-BP1, in mice increases the sensitivity to pentylenetetrazole (PTZ)- and kainic acid (KA)-induced seizures. We demonstrate that the deletion of 4E-BP2 in inhibitory, but not excitatory neurons, causes an increase in the susceptibility to PTZ-induced seizures. Moreover, mice lacking 4E-BP2 in parvalbumin, but not somatostatin or VIP inhibitory neurons exhibit a lowered threshold for seizure induction and reduced number of parvalbumin neurons. A mouse model harboring a human PIK3CA mutation that enhances the activity of the PI3K-AKT pathway (Pik3caH1047R-Pvalb ) selectively in parvalbumin neurons shows susceptibility to PTZ-induced seizures. Our data identify 4E-BP2 as a regulator of epileptogenesis and highlight the central role of increased mTORC1-dependent translation in parvalbumin neurons in the pathophysiology of epilepsy.

The link between lateral trunk flexion in Parkinson's disease and vestibular dysfunction: a clinical study.

INTRODUCTION: Lateral trunk flexion (LTF) is a common postural deformity in Parkinson's disease (PD). Postural control is known to depend on visual, vestibular, and somatosensory information. OBJECTIVES: This study aimed to investigate the relationship between vestibular dysfunction and postural abnormalities in PD patients with LTF. METHODS: We enrolled a total of 19 PD patients with LTF (PD-LTF+) and 19 age- and sex-matched PD patients without LTF (PD-LTF-). All patients underwent vestibular tests, including spontaneous nystagmus, gaze-evoked nystagmus, ocular movements, optokinetic eye test, fast positioning maneuvers, and the bithermal caloric test. RESULTS: Most of the PD-LTF + patients had abnormal vestibular function (11/19), while there were fewer vestibular function injuries in the control group (3/19). In PD-LTF + group, there were 5 patients (5/11, 45.5%) of peripheral vestibular dysfunction, 2 patients (2/11, 18.2%) of central vestibular damage, and 4 patients (4/11, 36.4%) of mixed injuries. The peripheral vestibular deficiencies could be either bilateral (4/9, 44.4%) or unilateral (5/9, 55.6%). The unilateral vestibular dysfunction was ipsilateral to the leaning side in 2 patients and contralateral to the leaning side in the other 3 patients. CONCLUSION: Vestibular dysfunction may be an independent risk factor for LTF in PD patients.

eIF2α controls memory consolidation via excitatory and somatostatin neurons.

An important tenet of learning and memory is the notion of a molecular switch that promotes the formation of long-term memory1-4. The regulation of proteostasis is a critical and rate-limiting step in the consolidation of new memories5-10. One of the most effective and prevalent ways to enhance memory is by regulating the synthesis of proteins controlled by the translation initiation factor eIF211. Phosphorylation of the α-subunit of eIF2 (p-eIF2α), the central component of the integrated stress response (ISR), impairs long-term memory formation in rodents and birds11-13. By contrast, inhibiting the ISR by mutating the eIF2α phosphorylation site, genetically11 and pharmacologically inhibiting the ISR kinases14-17, or mimicking reduced p-eIF2α with the ISR inhibitor ISRIB11, enhances long-term memory in health and disease18. Here we used molecular genetics to dissect the neuronal circuits by which the ISR gates cognitive processing. We found that learning reduces eIF2α phosphorylation in hippocampal excitatory neurons and a subset of hippocampal inhibitory neurons (those that express somatostatin, but not parvalbumin). Moreover, ablation of p-eIF2α in either excitatory or somatostatin-expressing (but not parvalbumin-expressing) inhibitory neurons increased general mRNA translation, bolstered synaptic plasticity and enhanced long-term memory. Thus, eIF2α-dependent mRNA translation controls memory consolidation via autonomous mechanisms in excitatory and somatostatin-expressing inhibitory neurons.

Association between the hydrogenase level and the occurrence of remote diffusion-weighted imaging lesions after spontaneous intracerebral hemorrhage.

To explore the influence of serum lactate dehydrogenase (LDH) level on remote diffusion-weighted imaging lesions (rDWILs) after spontaneous intracerebral hemorrhage (ICH). A consecutive cohort of 160 patients with spontaneous ICH who had brain MRI within 4 weeks of ICH onset were collected and analyzed retrospectively. rDWILs showed high signal on diffusion-weighted image (DWI) while low signal on apparent diffusion coefficient (ADC), and at least 20 mm away from the hemorrhage focus. The blood samples were obtained within 24 h after ICH onset from all patients. Lactate dehydrogenase (LDH) levels in blood were collected from serum biochemical tests. We use multivariate logistic regression analyses to investigate the association between serum LDH level and rDWILs after ICH. The average serum LDH level was 186.5 ± 35.6 U/L. And this level was higher in patients who presented rDWILs than in those without rDWILs. With the best cut-off value of 191 by using receiver operating characteristic (ROC) analysis, elevated LDH was associated with the presence of rDWILs independently (OR = 1.024, 95%CI = 1.011-1.037, P < 0.001) in the bivariate logistic regression analysis with adjustment for age, sex, previous ischemic stroke/TIA, smoker, SBP on admission, hematoma volume, and intraventricular hemorrhage (IVH). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of LDH ≥ 191 U/L for rDWILs were 70.4%, 72.2%, 33.9%, 94.2%, respectively. Our study suggests serum LDH level has a significant correlation with rDWILs after spontaneous ICH. Patients with higher serum LDH level in 24 h after ICH onset may be a useful predictor for rDWILs occurrence.

Single nucleotide polymorphisms in the non-coding region of STIM1 gene are associated with Parkinson disease risk in Chinese Han population.

The stromal interaction molecule 1 (STIM1) gene contributes essentially to Ca transport, thus it is functionally related to neurodegenerative disorders. The objective of this study was to investigate the correlation between single nucleotide polymorphisms (SNP) in the non-coding region of STIM1 gene and the risk for Parkinson disease (PD) in a Chinese Han population.In a cohort composed of 300 PD patients and 300 healthy individuals from a Chinese Han population, we analyzed genotypes for five novel SNPs, rs7934581, rs3794050, rs1561876, rs3750994 and rs3750996 in the non-coding region of STIM1 gene. The levels of STIM1 protein in plasma of these subjects were also assessed by enzyme-linked immunosorbent assay (ELISA).We found that the SNPs of STIM1 gene rs7934581, rs3794050, rs1561876, and rs3750996 were associated with increased PD risk, while rs3750994 SNP was not. An increased risk of PD was observed in subjects with the TAAG and TGAG haplotypes of rs7934581, rs3794050, rs1561876, rs3750996. Moreover, PD risk was significantly elevated only in subjects with age ≥60 years or females who carry the STIM1 rs3794050 minor allele. There was a significant difference in plasma STIM1 protein levels between subjects with different genotypes of STIM1 rs7934581, rs3794050, rs1561876, and rs3750996.STIM1 gene rs7934581, rs3794050, rs1561876, rs3750996 SNPs are associated with increased PD risk, and its mechanism may be related to abnormal STIM1 gene expression.

miR-124 ameliorates depressive-like behavior by targeting STAT3 to regulate microglial activation.

Major depressive disorder (MDD) is one of the most prevalent psychiatric disorders worldwide and a major public health concern that is associated with grave consequences. Systemic complexity and feedback processes among diverse drivers of the depression disorder contribute to the considerable variation in responses to the treatment of depression. Dysfunctional microRNA (miRNA) is involved in MDD. miR-124 is enriched in the brain and may be critical in neuronal differentiation. Previous studies have shown the value of miRNA-124 as a putative therapeutic target and a biomarker for major depression. However, the detailed mechanism of action of miR-124 in depression remains poorly understood. Here, we observed that miR-124 was downregulated in the hippocampus of mice with chronic unpredictable mild stress (CUMS). Restoration of miR-124 expression significantly attenuated depressive-like behavior and inhibited microglial activation induced by CUMS. Mechanistically, miR-124 directly targeted signal transducer and activator of transcription 3 (STAT3) in BV2 cells; in addition, upregulation of miR-124 inhibited the increase of inducible nitric oxide synthetase and proinflammatory cytokines, including IL-6, IL-1ß, TNF-α, and MCP-1, in LPS-stimulated BV2 cells. The collective data suggest that dysfunction of miR-124 may be a foundation for the development of depression by promoting microglial activation.

A clinical study of the coronal plane deformity in Parkinson disease.

BACKGROUND: Postural deformities in the coronal plane were frequent and disabling complications of PD, which reduces the quality of life of patients. This study aimed to garner greater attention to the Parkinson disease (PD)-related postural trunk deviations in the coronal plane by exploring a method for diagnosis because of the lack of any uniform diagnostic criteria and epidemiological studies. It also aimed to provide correlation data in the Chinese PD patients. METHODS: In this cross-sectional study, 503 consecutive outpatients with PD were enrolled who underwent standardized clinical evaluation. The study recruited 83 PD patients diagnosed with Pisa syndrome (PS). Scoliosis and coronal imbalance were diagnosed accurately by radiographic data. The PD patients were compared based on the Cobb angle and coronal balance for several demographic and clinical variables. RESULTS: PD patients with PS had a prevalence of 16.5%. The prevalence of coronal imbalance and scoliosis was 10.34 and 7.75%, respectively. PD patients with PS were older and had a more severe disease, significantly longer disease duration and treatment duration, and reduced quality of life. The most important finding was that the different morphology of the spinal level had an effect on the severity of coronal balance or Cobb angle. CONCLUSIONS: The present study indicated that the postural deformities in the coronal plane were related to the morphology of the spinal level, especially the position of the Cobb angle. To benefit the PD patients with PS, the full-length standing spine radiographs should be performed as early as possible.

Fine mapping and whole-exome sequencing of a familial cortical myoclonic tremor with epilepsy family.

Familial cortical myoclonic tremor with epilepsy (FCMTE) is an autosomal dominant epilepsy syndrome. Four loci, including 8q24 (FCMTE1), 2p11.1-q12.2 (FCMTE2), 5p15.31-p15.1 (FCMTE3), and 3q26.32-3q28 (FCMTE4) were previously reported. Herein, we report a new FCMTE1 pedigree from Chinese population with its clinical and genetic study results. Whole genome scan was performed to identify the causative gene region and copy number variants. Whole-exome sequencing was used to identify the causative gene. There were twelve affected members alive in this FCMTE1 pedigree. Nine affected members had both cortical myoclonic tremor and epilepsy, while three affected members had only cortical myoclonic tremor. Electrophysiologic examinations manifested giant somatosensory evoked potentials and long-latency cortical reflex in some affected members. Whole genome scan identified a 20.4 Mb causative gene region at 8q22.3-q24.13. No copy number variants were identified as the causative mutation. Whole-exome sequencing identified a co-segregated mutation (c.206A>T; p.Y69F) in the SLC30A8 gene. However, the evidence supporting this gene as the causative gene of FCMTE1 is not enough. We report the first Chinese FCMTE1 pedigree. No copy number variants, point mutation or small insertion/deletion were detected in the identified region that showed an association with FCMTE1. Further studies could focus on other possible genetic mechanisms while the association between the SLC30A8 and FCMTE1 needs further evidence.