Both gain- and loss-of-function variants of KCNA1 are associated with paroxysmal kinesignic dyskinesia.

KCNA1 is the coding gene for Kv1.1 voltage-gated potassium channel α subunit. Three variants of KCNA1 have been reported to manifest as paroxysmal kinesignic dyskinesia (PKD), but the correlation between them remains unclear due to the phenotypic complexity of KCNA1 variants as well as the rarity of PKD cases. Using the whole exome sequencing followed by Sanger sequencing, we screen potential pathogenic KCNA1 variants in patients clinically diagnosed with paroxysmal movement disorders and identify three previously unreported missense variants of KCNA1 in three unrelated Chinese families. The proband of one family (c.496G>A, p.A166T) manifests as episodic ataxia type 1, and the other two (c.877G>A, p.V293I; and c.1112C>A, p.T371A) manifest as PKD. The pathogenicity of these variants is confirmed by functional studies, suggesting that p.A166T and p.T371A cause a loss-of-function of the channel, while p.V293I leads to a gain-of-function with the property of voltage-dependent gating and activation kinetic affected. By reviewing the locations of PKD-manifested KCNA1 variants in Kv1.1 protein, we find that these variants tend to cluster around the pore domain, which is similar to epilepsy. Thus, our study strengthens the correlation between KCNA1 variants and PKD and provides more information on genotype-phenotype correlations of KCNA1 channelopathy.

Hybrid Membrane-Coated Nanoparticles for Precise Targeting and Synergistic Therapy in Alzheimer's Disease.

The blood brain barrier (BBB) limits the application of most therapeutic drugs for neurological diseases (NDs). Hybrid cell membrane-coated nanoparticles derived from different cell types can mimic the surface properties and functionalities of the source cells, further enhancing their targeting precision and therapeutic efficacy. Neuroinflammation has been increasingly recognized as a critical factor in the pathogenesis of various NDs, especially Alzheimer's disease (AD). In this study, a novel cell membrane coating is designed by hybridizing the membrane from platelets and chemokine (C-C motif) receptor 2 (CCR2) cells are overexpressed to cross the BBB and target neuroinflammatory lesions. Past unsuccessful endeavors in AD drug development underscore the challenge of achieving favorable outcomes when utilizing single-mechanism drugs.Two drugs with different mechanisms of actions into liposomes are successfully loaded to realize multitargeting treatment. In a transgenic mouse model for familial AD (5xFAD), the administration of these drug-loaded hybrid cell membrane liposomes results in a significant reduction in amyloid plaque deposition, neuroinflammation, and cognitive impairments. Collectively, the hybrid cell membrane-coated nanomaterials offer new opportunities for precise drug delivery and disease-specific targeting, which represent a versatile platform for targeted therapy in AD.

Blood-based CNS regionally and neuronally enriched extracellular vesicles carrying pTau217 for Alzheimer's disease diagnosis and differential diagnosis.

Accurate differential diagnosis among various dementias is crucial for effective treatment of Alzheimer's disease (AD). The study began with searching for novel blood-based neuronal extracellular vesicles (EVs) that are more enriched in the brain regions vulnerable to AD development and progression. With extensive proteomic profiling, GABRD and GPR162 were identified as novel brain regionally enriched plasma EVs markers. The performance of GABRD and GPR162, along with the AD molecule pTau217, was tested using the self-developed and optimized nanoflow cytometry-based technology, which not only detected the positive ratio of EVs but also concurrently presented the corresponding particle size of the EVs, in discovery (n = 310) and validation (n = 213) cohorts. Plasma GABRD+- or GPR162+-carrying pTau217-EVs were significantly reduced in AD compared with healthy control (HC). Additionally, the size distribution of GABRD+- and GPR162+-carrying pTau217-EVs were significantly different between AD and non-AD dementia (NAD). An integrative model, combining age, the number and corresponding size of the distribution of GABRD+- or GPR162+-carrying pTau217-EVs, accurately and sensitively discriminated AD from HC [discovery cohort, area under the curve (AUC) = 0.96; validation cohort, AUC = 0.93] and effectively differentiated AD from NAD (discovery cohort, AUC = 0.91; validation cohort, AUC = 0.90). This study showed that brain regionally enriched neuronal EVs carrying pTau217 in plasma may serve as a robust diagnostic and differential diagnostic tool in both clinical practice and trials for AD.

Constructing "smart" chelators by using an activatable prochelator strategy for the treatment of Wilson's disease.

Wilson's disease (WD) is a genetic disorder that primarily leads to the pathological accumulation of copper (Cu) in the liver, causing an abnormal increase in reactive oxygen species (ROS). The prevailing clinical therapy for WD involves lifelong use of Cu chelation drugs to facilitate Cu excretion in patients. However, most available drugs exert severely side-effects due to their non-specific excretion of Cu, unsuitable for long-term use. In this study, we construct a prochelator that enables precise and controlled delivery of Cu chelator drugs to the liver in WD model, circumventing toxic side effects on other organs and normal tissues. This innovative prochelator rapidly releases the chelator and the fluorescent molecule methylene blue (MB) upon activation by ROS highly expressed in the liver of WD. The released chelator coordinates with Cu, efficiently aiding in Cu removal from the body and effectively inhibiting the pathological progression of WD.

Alzheimer's disease early diagnostic and staging biomarkers revealed by large-scale cerebrospinal fluid and serum proteomic profiling.

Amyloid-ß, tau pathology, and biomarkers of neurodegeneration make up the core diagnostic biomarkers of Alzheimer disease (AD). However, these proteins represent only a fraction of the complex biological processes underlying AD, and individuals with other brain diseases in which AD pathology is a comorbidity also test positive for these diagnostic biomarkers. More AD-specific early diagnostic and disease staging biomarkers are needed. In this study, we performed tandem mass tag proteomic analysis of paired cerebrospinal fluid (CSF) and serum samples in a discovery cohort comprising 98 participants. Candidate biomarkers were validated by parallel reaction monitoring-based targeted proteomic assays in an independent multicenter cohort comprising 288 participants. We quantified 3,238 CSF and 1,702 serum proteins in the discovery cohort, identifying 171 and 860 CSF proteins and 37 and 323 serum proteins as potential early diagnostic and staging biomarkers, respectively. In the validation cohort, 58 and 21 CSF proteins, as well as 12 and 18 serum proteins, were verified as early diagnostic and staging biomarkers, respectively. Separate 19-protein CSF and an 8-protein serum biomarker panels were built by machine learning to accurately classify mild cognitive impairment (MCI) due to AD from normal cognition with areas under the curve of 0.984 and 0.881, respectively. The 19-protein CSF biomarker panel also effectively discriminated patients with MCI due to AD from patients with other neurodegenerative diseases. Moreover, we identified 21 CSF and 18 serum stage-associated proteins reflecting AD stages. Our findings provide a foundation for developing blood-based tests for AD screening and staging in clinical practice.

Gene therapy for monogenic disorders: challenges, strategies, and perspectives.

Monogenic disorders refer to a group of human diseases caused by mutations in single genes. While disease-modifying therapies have offered some relief from symptoms and delayed progression for some monogenic diseases, most of these diseases still lack effective treatments. In recent decades, gene therapy has emerged as a promising therapeutic strategy for genetic disorders. Researchers have developed various gene manipulation tools and gene delivery systems to treat monogenic diseases. Despite this progress, concerns about inefficient delivery, persistent expression, immunogenicity, toxicity, capacity limitation, genomic integration, and limited tissue specificity still need to be addressed. This review gives an overview of commonly used gene therapy and delivery tools, along with the challenges they face and potential strategies to counter them.

Paroxysmal Kinesigenic Dyskinesia: Genetics and Pathophysiological Mechanisms.

Paroxysmal kinesigenic dyskinesia (PKD), the most common type of paroxysmal movement disorder, is characterized by sudden and brief attacks of choreoathetosis or dystonia triggered by sudden voluntary movements. PKD is mainly caused by mutations in the PRRT2 or TMEM151A gene. The exact pathophysiological mechanisms of PKD remain unclear, although the function of PRRT2 protein has been well characterized in the last decade. Based on abnormal ion channels and disturbed synaptic transmission in the absence of PRRT2, PKD may be channelopathy or synaptopathy, or both. In addition, the cerebellum is regarded as the key pathogenic area. Spreading depolarization in the cerebellum is tightly associated with dyskinetic episodes. Whereas, in PKD, other than the cerebellum, the role of the cerebrum including the cortex and thalamus needs to be further investigated.

Biallelic variants in the COQ4 gene caused hereditary spastic paraplegia predominant phenotype.

INTRODUCTION: Hereditary spastic paraplegias (HSPs) comprise a group of neurodegenerative disorders characterized by progressive degeneration of upper motor neurons. Homozygous or compound heterozygous variants in COQ4 have been reported to cause primary CoQ10 deficiency-7 (COQ10D7), which is a mitochondrial disease. AIMS: We aimed to screened COQ4 variants in a cohort of HSP patients. METHODS: A total of 87 genetically unidentified HSP index patients and their available family members were recruited. Whole exome sequencing (WES) was performed in all probands. Functional studies were performed to identify the pathogenicity of those uncertain significance variants. RESULTS: In this study, five different COQ4 variants were identified in three Chinese HSP pedigrees and two variants were novel, c.87dupT (p.Arg30*), c.304C>T (p.Arg102Cys). More importantly, we firstly described two early-onset pure HSP caused by COQ4 variants. Functional studies in patient-derived fibroblast lines revealed a reduction cellular CoQ10 levels and the abnormal mitochondrial structure. CONCLUSIONS: Our findings revealed that bilateral variants in the COQ4 gene caused HSP predominant phenotype, expanding the phenotypic spectrum of the COQ4-related disorders.

Pathogenesis and therapeutic advances of cerebral autosomal- dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary cerebral small vessel disease in adults. Many CADASIL cases were reported after NOTCH3 was identified as the causative gene of CADASIL. However, there is still no specific and effective therapies for CADASIL. In this review, we summarize recent research progress on disease models, symptomatic treatments and potential therapies for CADASIL, thereby providing a reference for follow-up CADASIL treatment research.

CAT Interruption as a Protective Factor in Chinese Patients with Spinocerebellar Ataxia Type 1.

Spinocerebellar ataxia type 1 (SCA1) is the third most common type of spinocerebellar ataxias in China. CAT interruptions in the pathogenic alleles of SCA1 patients had only been reported by limited documents and there was a lack of data based on the Chinese population. In this study, we detected CAT interrupted pathogenic alleles in SCA1 patients from 4 out of 79 (5.1%) Chinese families. Their total CAG repeats were larger (median 58 vs. 47, p < 0.001) but ages at onset were later (median 46 vs. 38, p = 0.020). The longest uninterrupted CAG repeats could explain 65.4% of the AAO variance, making an increase of 28.0% compared to the total CAG repeats. The interruption pattern was greatly different between Chinese cohort and Caucasian cohort, indicating the effect of race.

CALHM2 V136G polymorphism reduces astrocytic ATP release and is associated with depressive symptoms and Alzheimer's disease risk.

INTRODUCTION: Depression is considered a prodromal state of Alzheimer's disease (AD), yet the underlying mechanism(s) by which depression increases the risk of AD are not known. METHODS: Single-nucleotide polymorphism (SNP) analysis was used to determine the CALHM2 variants in AD patients. Cellular and molecular experiments were conducted to investigate the function of CALHM2 V136G mutation. We generated a new genetically engineered Calhm2 V136G mouse model and performed behavioral tests with these mice. RESULTS: CALHM2 V136G mutation (rs232660) is significantly associated with AD. V136G mutation resulted in loss of the CALHM2 ATP-release function in astrocytes and impaired synaptic plasticity. Mice homozygous for the Calhm2 V136G allele displayed depressive-like behaviors that were rescued by administration of exogenous ATP. Moreover, Calhm2 V136G mutation predisposed mice to cognitive decline in old age. DISCUSSION: CALHM2 dysfunction is a biologically relevant mechanism that may contribute to the observed clinical correlation between depression and AD.

Application Value of Serum Neurofilament Light Protein for Disease Staging in Huntington's Disease.

BACKGROUND: Neurofilament light protein (NfL) has been proven to be a sensitive biomarker for Huntington's disease (HD). However, these studies did not include HD patients at advanced stages or with larger CAG repeats (>50), leading to a knowledge gap of the characteristics of NfL. METHODS: Serum NfL (sNfL) levels were quantified using an ultrasensitive immunoassay. Participants were assessed by clinical scales and 7.0 T magnetic resonance imaging. Longitudinal samples and clinical data were obtained. RESULTS: Baseline samples were available from 110 controls, 90 premanifest HD (pre-HD) and 137 HD individuals. We found levels of sNfL significantly increased in HD compared to pre-HD and controls (both P < 0.0001). The increase rates of sNfL were differed by CAG repeat lengths. However, there was no difference in sNfL levels in manifest HD from early to late stages. In addition, sNfL levels were associated with cognitive measures in pre-HD and manifest HD group, respectively. The increased levels of sNfL were also closely related to microstructural changes in white matter. In the longitudinal analysis, baseline sNfL did not correlate with subsequent clinical function decline. Random forest analysis revealed that sNfL had good power for predicting disease onset. CONCLUSIONS: Although sNfL levels are independent of disease stages in manifest HD, it is still an optimal indicator for predicting disease onset and has potential use as a surrogate biomarker of treatment effect in clinical trials. © 2023 International Parkinson and Movement Disorder Society.

Loss of CAA interruption and intergenerational CAG instability in Chinese patients with Huntington's disease.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by CAG expansions in huntingtin (HTT) gene, involving motor, cognitive, and neuropsychiatric symptoms. However, genetic modifiers and CAG repeat instability may lead to variations of clinical manifestations, making diagnosis of HD difficult. In this study, we recruited 229 HD individuals from 164 families carrying expanded CAG repeats of HTT, and analyzed loss of CAA interruption (LOI) on the expanded allele and CAG instability during germline transmission. Sanger sequencing and TA cloning were used to determine CAG repeat length and identify LOI variants. Detailed clinical features and genetic testing results were collected. We identified 6 individuals with LOI variants from 3 families, and all probands presented with earlier motor onset age than predicted onset age. In addition, we also presented 2 families with extreme CAG instability during germline transmission. One family showed an expansion from 35 to 66 CAG repeats, while the other family showed both CAG expansion and contraction in lineal three generations. In conclusion, we present the first document of Asian HD population with LOI variant, and we suggest that for symptomatic individuals with intermediate or reduced penetrance allele or negative family history, HTT gene sequencing should be considered in the clinical practice. KEY MESSAGES : We screened the loss of CAA interruption (LOI) variant in a Chinese HD cohort and presented the first document of Asian patients with Huntington's disease carrying LOI variant. We identified 6 individuals with LOI variants from 3 families, and all probands presented with earlier motor onset age than predicted onset age. We presented 2 families with extreme CAG instability during germline transmission. One family showed an expansion from 35 to 66 CAG repeats, while the other family showed both CAG expansion and contraction in lineal three generations. We suggest that for symptomatic individuals with intermediate or reduced penetrance allele or negative family history, HTT gene sequencing should be considered in the clinical practice.

Structures of the human Wilson disease copper transporter ATP7B.

The P-type ATPase ATP7B exports cytosolic copper and plays an essential role in the regulation of cellular copper homeostasis. Mutants of ATP7B cause Wilson disease (WD), an autosomal recessive disorder of copper metabolism. Here, we present cryoelectron microscopy (cryo-EM) structures of human ATP7B in the E1 state in the apo, the putative copper-bound, and the putative cisplatin-bound forms. In ATP7B, the N-terminal sixth metal-binding domain (MBD6) binds at the cytosolic copper entry site of the transmembrane domain (TMD), facilitating the delivery of copper from the MBD6 to the TMD. The sulfur-containing residues in the TMD of ATP7B mark the copper transport pathway. By comparing structures of the E1 state human ATP7B and E2-Pi state frog ATP7B, we propose the ATP-driving copper transport model of ATP7B. These structures not only advance our understanding of the mechanisms of ATP7B-mediated copper export but can also guide the development of therapeutics for the treatment of WD.

g-C3N4 Nanosheet Supported CuO Nanocomposites for the Electrochemical Carbon Dioxide Reduction Reaction.

We have prepared CuO-derived electrocatalysts on a graphitic carbon nitride (g-C3N4) nanosheet support for the electrochemical carbon dioxide reduction reaction (CO2RR). Highly monodisperse CuO nanocrystals made by a modified colloidal synthesis method serve as the precatalysts. We use a two-stage thermal treatment to address the active site blockage issues caused by the residual C18 capping agents. The results show that the thermal treatment effectively removed the capping agents and increased the electrochemical surface area. During the process, the residual oleylamine molecules incompletely reduced CuO to a Cu2O/Cu mixed phase in the first stage of thermal treatment, and the following treatment in forming gas at 200 °C completed the reduction to metallic Cu. The CuO-derived electrocatalysts show different selectivities over CH4 and C2H4, and this might be due to the synergistic effects of Cu-g-C3N4 catalyst-support interaction, varied particle sizes, dominant surface facets, and catalyst ensemble. The two-stage thermal treatment enables sufficient capping agent removal, catalyst phase control, and CO2RR product selection, and with precise controls of the experimental parameters, we believe that this will help to design and fabricate g-C3N4-supported catalyst systems with narrower product distribution.

Diverse CMT2 neuropathies are linked to aberrant G3BP interactions in stress granules.

Complex diseases often involve the interplay between genetic and environmental factors. Charcot-Marie-Tooth type 2 neuropathies (CMT2) are a group of genetically heterogeneous disorders, in which similar peripheral neuropathology is inexplicably caused by various mutated genes. Their possible molecular links remain elusive. Here, we found that upon environmental stress, many CMT2-causing mutant proteins adopt similar properties by entering stress granules (SGs), where they aberrantly interact with G3BP and integrate into SG pathways. For example, glycyl-tRNA synthetase (GlyRS) is translocated from the cytoplasm into SGs upon stress, where the mutant GlyRS perturbs the G3BP-centric SG network by aberrantly binding to G3BP. This disrupts SG-mediated stress responses, leading to increased stress vulnerability in motoneurons. Disrupting this aberrant interaction rescues SG abnormalities and alleviates motor deficits in CMT2D mice. These findings reveal a stress-dependent molecular link across diverse CMT2 mutants and provide a conceptual framework for understanding genetic heterogeneity in light of environmental stress.