Mutation In Family Research Articles

Cataract-prone variants of γD-crystallin populate a conformation with a partially unfolded N-terminal domain under native conditions.

Human γD-crystallin, a monomeric protein abundant in the eye lens nucleus, must remain stably folded for an individual's entire lifetime to avoid aggregation and protein deposition-associated cataract formation. γD-crystallin contains two homologous domains, an N-terminal domain (NTD) and a C-terminal domain (CTD), which interact via a hydrophobic interface. Several familial mutations in the gamma crystallin gene are linked to congenital early-onset cataract, most of which affect the NTD. Some of these, including V75D and W42R, are known to populate intermediates under partially denaturing conditions possessing a natively folded CTD and a completely unfolded NTD. We employed hydrogen-deuterium exchange mass spectrometry to probe the structural and energetic features of variants of γD-crystallin under both native and partially denaturing conditions. For V75D and W42R, we identify a species under native conditions that retains partial structure in the NTD and is structurally and energetically distinct from the intermediate populated under partially denaturing conditions. Residues at the NTD-CTD interface play crucial roles in stabilizing this intermediate, and disruption of interface contacts either by amino acid substitution or partial denaturation permits direct observation of two intermediates simultaneously. These data suggest that the intermediate identified under native conditions is accessed from the native state and not on the folding pathway. The intermediate we have identified here exposes hydrophobic amino acids that are buried in both the folded full-length protein and in the protein's stable isolated domains. Such nonnative exposure of a hydrophobic patch may play an important role in cataract formation.

A novel EYA1 splicing mutation in a Chinese branchio-oto syndrome family with functional analysis and reproductive intervention.

Branchio-oto syndrome (BOS) is a group of autosomal dominant genetic diseases, multisystem disorders excluding renal anomalies. There are clinical heterogeneity and ethnic diversity in BOS, which reported in more studies in European populations than in Asian populations, with a prevalence rate of approximately 1/40000. As the most common disease-causing gene, the mutation types of EYA1 range from missense to various frameshift, splicing and nonsense variants. Although splicing mutations are one of the important factors in the disease, existed research has paid less attention to the novel mutations causing aberrant RNA splicing and their pathogenic mechanisms. Reproductive interventions that actively block the transmission of the disease to future generations have also not been reported. We had collected research samples from a three-generation Chinese family with BOS. Whole exome sequencing was applied for the screening of candidate causing gene. Minigene assay was performed to identify the aberrant splicing products, and molecular biology techniques were used to analyze the pathogenicity of potentially mistranslated proteins. pre-implantation genetic testing (PGT) has been employed to prevent hearing loss in this family based on SNP analysis. A novel mutation EYA1:c.1598-2AG>TA was identified by whole-exome sequencing and classified as harmful refer to ACMG's evidence. An aberrant RNA splicing was verified and suggested that might prematurely terminates the translation of EYA1 protein, through the minigene assay. The EYA1 truncated protein presented unstable and difficultly translocated to the nucleus, also impaired EYA1-SIX1 interactions in cytological experiments. PGT helped the proband give birth to a healthy boy. A novel splicing variant of EYA1 gene was identified in this study, and the potential molecular pathogenic mechanism was elucidated by several functional experiments. On basis above findings, we successfully implemented the first instance of using PGT to ensure the birth of a healthy offspring free from this genetic disorder.

Exploration of novel biomarkers and novel therapies for immune checkpoint inhibitors (ICIs) in genetic variants of esophageal squamous cell carcinoma (ESCC): A study of 1,059 Japanese cases.

495 Background: In Japan, cancer genome profiling (CGP) tests will be covered by insurance in 2019, and more than 1,000 ESCC cases have been accumulated in the national database. ICIs are currently the key drugs for esophageal cancer, and MSI and TMB status can work as biomarkers for ICIs in solid tumors. Therefore, to improve the prognosis of esophageal squamous cell carcinoma (ESCC), we aim to search for gene variants that may predict the efficacy of ICIs and explore the possibility of new treatment from genetic data accumulated in the Japanese nation-wide C-CAT database. Methods: We retrospectively analyzed 1,059 ESCC cases from C-CAT data accumulated from June 2019 to February 2024. We used the registered clinical and genetic information to examine gene variants and carcinogenic pathways that could serve as biomarkers for ICIs. Results: Of the 1059, 152 (14.4%) had TMB-H and 3 (0.3%) had MSI-H, with a median TMB of 5.0 Muts/Mb (range: 0-268). XPO1 and TP53 were found to be positively and negatively correlated as genes affecting TTF in nivolumab monotherapy (FDR P value < 0.01). TMB has the potential to be a biomarker for ICI, but TMB was significantly higher in the group with variants in the ARID family ( ARID2 , ARID1A plus ARID5B ) (median TMB 5.0 vs 8.0 Muts/Mb, P<0.001). In addition, 709 patients (66.9%) had any variants in three pathways (TP53, RTK and cell cycle), which are thought to be involved in the carcinogenesis of ESCC. PIK/Akt/mTOR and epigenetic modulation pathways were also found to be abnormal in many cases, and abnormalities in the epigenetic modification pathway were found to contribute significantly to TMB-H (FDR P value<0.01, Logarithmic value=19.2). Conclusions: This is the first case-specific report on the relationship between mutations in the ARID family and TMB in ESCC and the signalling pathways leading to carcinogenesis. In the present study, the association between the ARID family and TMB, and between abnormalities in the epigenetic modification pathway and TMB, which has been previously reported in other cancer types but not in esophageal cancer, suggests that multiple pathological mutations including these may be new biomarkers for ICI in 1059 Japanese patients. Furthermore, multiple pathways are often involved in ESCC carcinogenesis at the same time, and a separate, combined approach that takes these into account may be necessary in the development of new drugs.

A cellular model of TDP-43 induces phosphorylated TDP-43 aggregation with distinct changes in solubility and autophagy dysregulation.

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease that affects neurons in the brain and spinal cord, causing loss of muscle control, and eventually leads to death. Phosphorylated transactive response DNA binding protein-43 (TDP-43) is the major pathological protein in both sporadic and familial ALS, forming cytoplasmic aggregates in over 95% of cases. Of the 10-15% of ALS cases that are familial, mutations in TDP-43 represent about 5% of those with a family history. We have developed an in vitro overexpression model by introducing three familial ALS mutations (A315T, M337V, and S379P) in the TDP-43 (TARDBP) gene which we define as 3X-TDP-43. This overexpression model TDP-43 shows deficits in autophagy flux and colocalization of TDP-43 with stress granules. We also observe a progressive shift of TDP-43 to the cytoplasm in this model. This overexpression model shows a reduction in solubility of phosphorylated TDP-43 from RIPA to urea soluble. Four glycolytic enzymes, phosphoglycerate kinase one (PGK1), aldolase A (ALDOA), enolase 1 (ENO1), and pyruvate dehydrogenase kinase 1 (PDK1) show significant time-dependent decreases in 3X-TDP-43 expressing cells. Shotgun proteomic analysis shows global changes in the importin subunit alpha-1 (KPNA2), heat shock 70 kDa protein 1A (HSPA1A), and protein disulfide-isomerase A3 (PDIA3) expression levels and coimmunoprecipitation reveals that these proteins complex with TDP-43. Overall, these results suggest that the 3X-TDP-43 model may provide new insights into pathophysiology and an avenue for drug screening in vitro for those suffering from ALS and related TDP-43 proteinopathies.

Informatics strategies for early detection and risk mitigation in pancreatic cancer patients.

This review provides a comprehensive overview of the current landscape in pancreatic cancer (PC) screening, diagnosis, and early detection. This emphasizes the need for targeted screening in high-risk groups, particularly those with familial predispositions and genetic mutations, such as BRCA1, BRCA2, and PALB2. This review highlights the sporadic nature of most PC cases and significant risk factors, including smoking, alcohol consumption, obesity, and diabetes. Advanced imaging techniques, such as Endoscopic Ultrasound (EUS) and Contrast-Enhanced Harmonic Imaging (CEH-EUS), have been discussed for their superior sensitivity in early detection. This review also explores the potential of novel biomarkers, including those found in body fluids, such as serum, plasma, urine, and bile, as well as the emerging role of liquid biopsy technologies in analyzing circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and exosomes. AI-driven approaches, such as those employed in Project Felix and CancerSEEK, have been highlighted for their potential to enhance early detection through deep learning and biomarker discovery. This review underscores the importance of universal genetic testing and the integration of AI with traditional diagnostic methods to improve outcomes in high-risk individuals. Additionally, this review points to future directions in PC diagnostics, including next-generation imaging, molecular biomarkers, and personalized medicine, aiming to overcome current diagnostic challenges and improve survival rates. Ultimately, the review advocates the adoption of informatics and AI-driven strategies to enhance early detection, reduce morbidity, and save lives in the fight against pancreatic cancer.

A rare haplotype of the GJD3 gene segregating in familial Meniere’s disease interferes with connexin assembly

BackgroundFamilial Meniere’s disease (FMD) is a rare polygenic disorder of the inner ear. Mutations in the connexin gene family, which encodes gap junction proteins, can also cause hearing loss, but their role in FMD is largely unknown.MethodsWe retrieved exome sequencing data from 94 individuals in 70 Meniere's disease (MD) families. Through gene burden analysis, we calculated the enrichment of rare variants (allele frequency < 0.05) in connexins genes in FMD individuals compared with the reference population. The connexin monomer and the homomeric connexon structural models were predicted using AlphaFold2 and HDOCK. RT-qPCR and immunofluorescence were done in mice cochleae to identify expression of the mouse ortholog candidate gene Gjd3.ResultsWe found an enrichment of rare missense variants in the GJD3 gene when comparing allelic frequencies in FMD (N = 94) with the Spanish reference population (OR = 3.9[1.92–7.91], FDR = 2.36E-03). In the GJD3 sequence, we identified a rare haplotype (TGAGT) composed of two missense, two synonymous, and one downstream variant. This haplotype was found in five individuals with FMD, segregating in three unrelated families with a total of ten individuals; and in another eight MD individuals. GJD3 encodes the gap junction protein delta 3, also known as human connexin 31.9 (Cx31.9). The protein model predicted that the NP_689343.3:p.(His175Tyr) missense variant could modify the interaction between connexins and the connexon assembly, affecting the homotypic GJD3 gap junction between cells. Our studies in mice revealed that Gjd3—encoding Gjd3 or mouse connexin 30.2 (Cx30.2)—was expressed in the organ of Corti and vestibular organs, particularly in the tectorial membrane, the base of inner and outer hair cells and the nerve fibers.ConclusionsThe present results describe a novel association between GJD3 and FMD, providing evidence that FMD is related to changes in the inner ear channels, and supporting a new role of tectorial membrane proteins in MD.

NR1D1 Inhibition Enhances Autophagy and Mitophagy in Alzheimer's Disease Models.

Alzheimer's disease (AD) is marked by extracellular beta-amyloid (Aβ) plaques and intracellular Tau tangles, leading to progressive cognitive decline and neuronal dysfunction. Impaired autophagy, a process by which a cell breaks down and destroys damaged or abnormal proteins and other substances, contributes to AD progression. This study investigated Nuclear Receptor Subfamily 1 Group D Member 1 (NR1D1) as a potential therapeutic target for modulating autophagy. We show that NR1D1 depletion significantly enhances autophagic flux and mitophagy in human cell lines as well as wildtype and AD Caenorhabditis elegans (C. elegans) models. Our findings revealed that NR1D1 knockdown increased autophagy markers and activated the proteins Sirtuin 1 (SIRT1) and CTSB cathepsin B (Cathepsin B), both linked to autophagy function. In 5 familial AD mutations (5xFAD) mice, Nr1d1 knockdown restored the expression level of autophagy markers. C. elegans experiments revealed that depletion of the worm ortholog of NR1D1, nhr-85, improved neuronal mitophagy, enhanced associative memory in amyloid-β models, and extended lifespan. These findings suggest NR1D1 as a promising therapeutic target for improving cellular autophagy mechanisms in AD.

A New Case of Kilquist's Syndrome with a Novel Variant in SLC12A2 and a Brief Review of the Literature

Abstract Background Kilquist's syndrome is a recently described rare disease characterized by hearing loss, secretory dysfunction, gastrointestinal system abnormalities, and neurological anomalies including hypotonia and global developmental delay. It is caused by mutations in the solute carrier family 12 member 2 (SLC12A2) gene, which encodes the Na-K-2Cl cotransporter isoform 1 (NKCC1). Objective The aim of this study was to contribute to understanding the genotype–phenotype correlations of SLC12A2 variants. Material and Methods We evaluated a Turkish patient with a novel variant in SLC12A2 and reviewed all previously reported cases with Kilquist's syndrome. Whole exome sequencing and Sanger sequencing were used as molecular genetic testing methods. Results Whole exome sequencing revealed a nonsense homozygous NM_001046.3: c.2534G &gt; A (pW845*) variant in the SLC12A2 gene. Sanger sequencing confirmed the variant. The patient was homozygous for this variant; the parents were heterozygous. Conclusion This is the first Turkish patient with a novel variant in SLC12A2 reported in the literature. With this report, we have contributed to expanding the clinical and mutation spectrum of SLC12A2.

Bioinformatics Analysis of a 4bp Homozygous Deletion Mutation of EDAR Gene Identified as an Important Cause of Hypohidrotic Ectodermal Dysplasia in Pakistan

Hypohidrotic Ectodermal Dysplasia (HED) is a rare congenital disorder characterized by reduced hair, the absence of sweat glands, dental anomalies, and craniofacial malformations. This condition can be inherited through X-linked, autosomal recessive, or autosomal dominant modes of inheritance. Mutations in four specific genes (EDAR, EDA, WNT10A, and EDARADD) are known to cause HED. In a study to identify a pathogenic mutation in a consanguineous Pakistani family with the autosomal recessive form of HED, microsatellite markers were utilized to genotype the known loci associated with the disease. The condition in this family was mapped to the EDAR gene locus located on chromosome 2q11-q13. Upon screening the EDAR gene, a novel homozygous 4bp deletion (718delAAGA) in exon 8 was identified, which segregated with the disease phenotype. This 4bp deletion in the EDAR gene results in a frameshift and early termination of translation, producing a truncated protein of 245 amino acids instead of the normal length of 539 amino acids. Various bioinformatics tools were employed to analyze the pathogenic mutation linked to a significant number of HED cases in Pakistan. I-TASSER was used to model the protein structure, CASTp facilitated the identification of various pockets, and STiTCH 3.1 determined EDA to be the ligand for EDAR. Docking analysis were conducted for both the mutant and wild-type EDAR proteins with EDA, revealing notable differences in the interaction sites between the docked complexes of the normal and mutant forms of EDAR with the ligand EDA. These analyses provided insights into the protein's structural features, active sites, interactions, and the overall impact of the mutation.

Genetic syndromes associated with pancreatic neuroendocrine neoplasms and imaging diagnostic strategies.

Pancreatic neuroendocrine neoplasms (pNENs) are the second most common pancreatic malignancy. While most cases are sporadic, a small proportion is associated with genetic syndromes, such as Multiple Endocrine Neoplasia (MEN), Von Hippel-Lindau Syndrome (VHL), Neurofibromatosis Type 1 (NF1), and Tuberous Sclerosis Complex (TSC). This review aims to use pNENs as a clue to reveal the full spectrum of disease, providing a comprehensive understanding of diagnosis. It aids in promptly identifying abnormalities in other organs, recognizing familial genetic mutations, and achieving personalized treatment.

Familial Alzheimer's disease mutations in amyloid precursor protein impair calcineurin signaling to NMDA receptors.

Familial Alzheimer's disease (FAD) is frequently associated with mutations in the amyloid precursor protein (APP), which are thought to lead to cognitive deficits by impairing NMDA receptor (NMDAR)-dependent forms of synaptic plasticity. Given the reliance of synaptic plasticity on NMDAR-mediated Ca2+ entry, shaping of NMDAR activity by APP and/or its disease-causing variants could provide a basis for understanding synaptic plasticity impairments associated with FAD. A region of APP (residues 639-644 within APP695) processed by the γ-secretase complex, which generates amyloid β (Aβ) peptides, is a hotspot for FAD mutations. This region bears similarity to a binding motif for calcineurin (CaN), a Ca2+/calmodulin-dependent phosphatase. Interaction assays confirm that APP associates with CaN in native tissue as well as in a heterologous expression system. This capacity to bind CaN extends to APP family members amyloid precursor-like protein 1 and amyloid precursor-like protein 2 (APLP1 and APLP2, respectively). Electrophysiological analysis demonstrates that APP and its family members limit NMDAR activity, in a manner consistent with CaN-dependent regulation of NMDAR desensitization. FAD mutations, in this region of APP, impair this regulation and consequently enhance NMDAR activity. Thus, by altering the landscape for CaN regulation of NMDA receptors, FAD mutations in APP may contribute to faulty information processing by modifying the dynamic range and temporal window of a critical signal for synaptic plasticity.

Medial temporal lobe subregional atrophy patterns in presymptomatic and symptomatic genetic frontotemporal lobar degeneration

AbstractBackgroundMedial temporal lobe (MTL) atrophy is an early feature of multiple neurodegenerative diseases. In genetic frontotemporal lobar degeneration (FTLD, i.e. individuals carrying GRN, MAPT, or C9orf72 mutations), MTL atrophy can occur 10‐15 years before symptom onset. We aimed to better characterize MTL atrophy patterns in presymptomatic and symptomatic genetic FTLD using a multi‐atlas segmentation pipeline that allows precise measurement of MTL subregions.MethodParticipants included a diagnostically mixed sample of familial FTLD mutation carriers (MAPT: N=87; C9orf72: N=117; GRN: N=65) and 142 non‐carrier family member controls from the ALLFTD study cohort (Table 1). T1‐weighted MRIs were preprocessed using a multi‐atlas automated pipeline (Automatic Segmentation of Hippocampal Subfields [ASHS]) to segment the amygdala, anterior and posterior hippocampus, and MTL cortices: entorhinal cortex (ERC), perirhinal cortex or Brodmann areas (BA) 35 and 36, and parahippocampal cortex (PHC). Following rigorous quality control and manual correction (Figure 1), we assessed bilateral volume differences in mutation carriers compared to controls, adjusted for age, sex, and total intracranial volume. Analyses were conducted separately for symptomatic (FTLD‐Clinical Dementia Rating Global Score&amp;ge;0.5) and presymptomatic (Global Score=0) mutation carriers.ResultOut of 413 scans, 317 (76.8%) segmentations passed quality control while 94 (22.8%) needed some manual edits—this was more common in symptomatic than presymptomatic carriers (32% versus 15%, p=0.001). Three scans were excluded (&lt;1%; 2 complete scans, 1 for selected subregions) due to insufficient landmark visibility in symptomatic GRN and MAPT carriers. In symptomatic carriers, all MTL subregions demonstrated reduced volume compared to controls, although MAPT carriers exhibited particularly marked atrophy, especially in anterior MTL subregions (Table 2; amygdala, ERC, BA35, hippocampus). Presymptomatic MAPT and C9orf72 carriers also exhibited significant atrophy of primarily anterior MTL cortices, while presymptomatic GRN carriers only exhibited significantly smaller ERC volume compared to controls.ConclusionMTL atrophy is present in genetic FTLD across mutation carriers, even at the presymptomatic stage. Anterior MTL subregions, which are also susceptible to neuropathologic accumulation in early Alzheimer’s disease and Limbic‐predominant age‐related TDP‐43 encephalopathy neuropathologic change (LATE‐NC), tend to be more vulnerable than posterior subregions. Unsurprisingly, MAPT carriers show the greatest MTL atrophy compared to controls across groups.

Carbonic Anhydrase Inhibitors rescue microvascular impairment and neuroinflammation in 3xTg AD mice

AbstractBackgroundAlzheimer’s disease (AD) is characterized‐ at both early and late stages‐ by neurovascular impairment. In AD, dysfunctional cerebral microvasculature is accompanied by an inflammatory response, contributing to Aβ and tau accumulation, brain cell stress and death, impaired clearance of metabolic waste, BBB permeability, and ultimately leading to neuronal demise and cognitive impairment. We previously showed that Aβ peptides induce mitochondrial dysregulation and caspase‐mediated apoptosis in brain cells, including endothelial, glial, and smooth muscle cells. Moreover, we found FDA‐approved carbonic anhydrase inhibitors (CAIs), acetazolamide (ATZ) and methazolamide (MTZ), clinically used for non‐AD related conditions, effectively rescue these pathological events, and ameliorate cognitive impairment, brain amyloidosis, and vascular and glial fitness, in an AD/CAA (Cerebral Amyloid Angiopathy) in vivo model. We unveiled a mitochondrial isoform, Carbonic Anhydrase (CA‐VB), as a major player in Aβ‐mediated toxicity, with increased CA‐VB levels in AD/CAA mouse and human brains.Method3xTg mice express three familial AD mutations: Swedish APP mutation (KM670/671NL), PSEN1 M146V mutation, and MAPT P301L mutation. Following 10 month‐CAI‐diet, mice were sacrificed at 16 months of age,. Brains were harvested and processed for biochemical and immunohistochemistry analysis.ResultCAIs ameliorate cognitive dysfunction, and significantly reduce hippocampal and cortical Aβ deposition and Thioflavin S positive deposits in 3xTg mice. Specifically in the hippocampus, CAIs rescue OXPHOS complexes dysregulated expression, reduce mitochondrial CA‐VB expression, and prevent caspase‐3 activation. In hippocampus and cortex, 3xTg present loss of PDGFRβ (microvascular marker) and increased gliosis (GFAP and IBA1), which are rescued by CAIs.ConclusionCAIs show positive behavioral outcomes in 16‐month‐old 3xTg mice, and reduce brain amyloidosis, compared to untreated animals. In the hippocampus, CAIs foster microvascular health and reduce inflammatory state, and in the cortex, MTZ decreases microgliosis, unveiling cell specific CAI effects underlying Aβ deposition reduction observed in both areas. This work points to CAIs as a potential therapeutic strategy to treat brain microvascular impairment and neuroinflammation, preventing mitochondria‐mediated cell stress and death.

Integrated Analysis of Polymerase Family Gene Mutations in Acute Myeloid Leukemia: Clinical Features, Prognosis, and Bioinformatics Insights.

Background and Objectives: The long-term prognosis of acute myeloid leukemia (AML) is challenging due to limited understanding of the molecular markers involved in its development. This study investigates the role of DNA polymerases in AML to offer new insights for diagnosis and treatment. Materials and Methods: A retrospective study on pediatric AML patients with POL gene family mutations from 2021 to 2024 was conducted. Patients were categorized based on risk stratification criteria, and the DAH regimen was used for induction chemotherapy. Bioinformatics analysis integrated data from various databases to identify key genes and develop survival analysis plots and AUC curves. Results: The study included 59 pediatric AML patients, revealing no significant differences in demographic or clinical characteristics between those with and without POL family gene mutations. However, patients with POL gene mutations showed higher complete remission rates after initial DAH chemotherapy (91.67% vs. 59.57%, p = 0.03607), indicating a potential treatment benefit. High expression of four POL genes (POLD1, POLE, POLG, and POLQ) in bone marrow and immune cells suggests their crucial role in hematopoiesis and immune response. Survival analysis across different datasets indicated that AML patients with overexpressed POL family genes had significantly worse outcomes, proposing these genes as potential prognostic biomarkers for AML. Conclusions: This study on pediatric AML demonstrates that POL gene family mutations are associated with higher remission rates post-chemotherapy, indicating their potential as prognostic markers. Bioinformatics analysis emphasizes the significance of these mutations in AML, highlighting their impact on disease prognosis.

Clinical and Genetic Characteristics of 40 Patients with Non-Muscle Myosin Heavy Chain 9-Related Disease (MYH9-RD) Misdiagnosed as ITP: A Retrospective Analysis in China.

Myosin Heavy Chain 9-related diseases (MYH9-RD) are rare autosomal dominant platelet disorders characterised by macrothrombocytopaenia and leukocyte inclusion bodies. They can manifest with non-haematological complications, including deafness, nephropathy, or cataracts. Due to its rarity and its similar clinical presentation with immune thrombocytopaenia (ITP), MYH9-RD is often misdiagnosed as ITP, leading to inappropriate treatment and delayed management of complications. The study aimed to evaluate clinical, therapeutic, and genetic aspects of patients with MYH9-RD misdiagnosed with ITP, comparing differences between Chinese paediatric and adult cases of this condition. This multi-centre retrospective study included data obtained from Chinese patients diagnosed with MYH9-RD between January 2014 and December 2023 at five centres. Adults exhibited significantly longer median misdiagnosis (9 years vs. 0.2 years, p < 0.001) and treatment durations (1.5 years vs. 0.1 years, p < 0.001) than children. Non-haematological manifestations were exclusive to adults (10/21). All patients received inappropriate ITP treatments, with adults receiving more different treatments. Genetic analysis revealed 21 spontaneous mutations (52.5%), 12 familial mutations, and 7 mutations of unknown inheritance patterns. Two novel mutations (p.G1517V and p.K1674Q) were identified. Patients with p.R702C mutation demonstrated early-stage kidney injury and hearing loss. Adult patients with MYH9-RD face elevated risks of misdiagnosis, prolonged inappropriate treatment, and non-haematological complications than paediatric patients. Enhanced awareness, consideration of mean platelet volume, family history, and genetic screening are crucial for accurate MYH9-RD diagnosis and management. The prevalence of spontaneous mutations and identified genotype-phenotype correlations warrant further investigation in the Chinese population.

Activation of the muscle‐to‐brain‐axis reduces amyloid plaque accumulation and rescues behavioral deficits by enhancing synaptic integrity and neurotrophic signaling in a mouse model of Alzheimer’s disease

AbstractBackgroundAlzheimer’s disease (AD) is associated with complex pathophysiology including synaptic dysregulation, compromised neurotrophic signaling, deficits in autophagic flux and neuroinflammation). Skeletal muscle regulates many brain functions relevant to aging, by activating the muscle‐to‐brain axis through the secretion of skeletal muscle originating factors (myokines) with cellular‐modifying, neuro and geroprotective properties. Our group developed transgenic mice that overexpress the skeletal muscle human Transcription Factor EB (TFEB), a master regulator of lysosomal‐to‐nucleus signaling, resulting in enhanced proteostasis and neuroprotection in a Tau mouse model. However, the precise mechanisms remain unknown. Therefore, we further validated these effects in an AD amyloid β (Aβ) mouse model and investigated the underlying mechanism.MethodWe crossbred female 5xFAD mice, carrying 5 AD familial mutations, with transgenic mice that overexpress human TFEB to create 5xFAD;cTFEB;HSA‐Cre (3FA) mice. At 4 and 8 months of age, we analyzed Aβ plaque accumulation through immunohistochemistry and conducted western blot analysis for multiple synaptic markers, growth factors, autophagic/lysosomal regulators, and myokines across the muscle‐to‐brain axis. We also performed a battery of neurocognitive tests (open field, the Barnes maze, and fear conditioning) at 8 months of age, when this model has previously been reported to demonstrate robust cognitive impairment.ResultSkeletal muscle‐targeted TFEB expression reduced Aβ plaque accumulation in cortices of 4‐month‐old female mice. Furthermore, muscle‐TFEB expression altered synaptic‐associated gene transcriptional signatures in hippocampi, and rescued behavioral deficits in 8‐month‐old female 5xFAD mice. Western blots of cortex from 8‐month‐old female 3FA mice confirmed a rescue of several synaptic markers including SNAP25, synaptophysin I, synaptotagmin I and PSD95, neurotrophic factors such as BDNF and autophagic/lysosomal regulators such as Cathepsin D and B, prosaposin (PSAP) and saposin C. Levels of PSAP (a recently identified exercise‐responsive myokine) were also increased in skeletal muscle, plasma and cortices, suggesting that PSAP may act as a novel myokine involved in muscle‐to‐brain rescue mechanisms. scle, plasma and cortices of 8‐month‐old female mice, suggesting that PSAP may act as a novel myokine involved in muscle‐to‐brain rescue mechanisms.ConclusionSkeletal muscle directly regulates CNS function and health in the 5xFAD model regulating synaptic integrity, neurotrophic signaling and autophagic flux, potentially through release of CNS‐targeting myokines.

Characterizing plasma biomarkers of Alzheimer’s disease in three non‐human primate species: marmosets, titi monkeys, and capuchins

AbstractBackgroundStudies of aging in non‐human primates are important to elucidate primate‐specific mechanisms underlying human aging, including pathological trajectories like Alzheimer’s disease (AD). Evidence of AD‐like brain aging has been reported across the primate order including amyloid beta (AB) deposits, but blood‐based biomarkers are less well‐studied. The goal of this project was to explore the use of validated assays for plasma biomarkers in two new non‐human primate species: coppery titi monkeys (Plecturocebus cupreus) and brown capuchins (Sapajus apella). We aimed to 1) assess the utility of the assay, 2) establish normative values, and 3) explore age‐related differences in biomarker levels. For each species, we assessed biomarkers sensitive to physiologic aging and pathological conditions including neurodegeneration/neuronal injury (neurofilament light chain, NfL), neuroinflammation (glial fibrillary acidic protein, GFAP), neuropathology (AB40, AB42, pathological tau).MethodPlasma samples were obtained from males and females of adult common marmosets (Callithrix jacchus) (n=85), titi monkeys (n= 33), and capuchins (n=19), and evaluated using MesoScale Discovery (MSD): AB Peptide 4G8 Panel &amp; Neurology Panel 1multi‐plex ELISAs. Samples from genetically engineered marmosets with early onset familial mutations in the presenilin 1 (PSEN1) gene were included as positive controls and benchmarks (Sukoff Rizzo et. al, 2023).ResultAB40, AB42, Tau, GFAP, and NfL were detectable in plasma from titi monkeys and capuchins. Biomarker levels across ages of each species had comparative values and overlapping ranges with wildtype (WT) adult marmosets. Consistent with previous data PSEN1 knock‐in marmosets had the expected increase in plasma AB42 relative to WT, with some individuals of each species showing naturally elevated levels. For both marmosets and titis, NfL was found to increase with advancing age. Titi monkeys also showed increases in AB40 and GFAP with age.ConclusionThe present data are the first to demonstrate normative values for plasma biomarkers of neurodegeneration, neuroinflammation, and neuropathology in capuchin and titi monkeys. Preliminary results show comparative values and aging trajectories across three species of non‐human primates. Ongoing studies are evaluating additional individuals and species, to longitudinally track aging which will facilitate understanding primate‐specific mechanisms underlying healthy human aging as well as AD.

The novel estrogen receptor beta agonist EGX358 and APOE genotype influence memory, vasomotor, and anxiety outcomes in an Alzheimer's mouse model.

Alzheimer's disease (AD) prevalence and severity are associated with increased age, female sex, and apolipoprotein E4 (APOE4) genotype. Although estrogen therapy (ET) effectively reduces symptoms of menopause including hot flashes and anxiety, and can reduce dementia risk, it is associated with increased risks of breast and uterine cancer due to estrogen receptor alpha (ERα)-mediated increases in cancer cell proliferation. Because ERβ activation reduces this cell proliferation, selective targeting of ERβ may provide a safer method of improving memory and reducing hot flashes in menopausal women, including those with AD. APOE genotype influences the response to ET, although it is unknown whether effects of ERβ activation vary by genotype. Here, we tested the ability of long-term oral treatment with a novel highly selective ERβ agonist, EGX358, to enhance object recognition and spatial recognition memory, reduce drug-induced hot flashes, and influence anxiety-like behaviors in female mice expressing 5 familial AD mutations (5xFAD-Tg) and human APOE3 (E3FAD) or APOE3 and APOE4 (E3/4FAD). Mice were ovariectomized at 5 months of age and were then treated orally with vehicle (DMSO) or EGX358 (10 mg/kg/day) via hydrogel for 8 weeks. Spatial and object recognition memory were tested in object placement (OP) and object recognition (OR) tasks, respectively, and anxiety-like behaviors were tested in the open field (OF) and elevated plus maze (EPM). Hot flash-like symptoms (change in tail skin temperature) were measured following injection of the neurokinin receptor agonist senktide (0.5 mg/kg). EGX358 enhanced object recognition memory in E3FAD and E3/4FAD mice but did not affect spatial recognition memory. EGX358 also reduced senktide-induced tail temperature elevations in E3FAD, but not E3/4FAD, females. EGX358 did not influence anxiety-like behaviors or body weight. These data indicate that highly selective ERβ agonism can facilitate object recognition memory in both APOE3 homozygotes and APOE3/4 heterozygotes, but only reduce the magnitude of a drug-induced hot flash in APOE3 homozygotes, suggesting that APOE4 genotype may blunt the beneficial effects of ET on hot flashes. Collectively, these data suggest a potentially beneficial effect of selective ERβ agonism for memory and hot flashes in females with AD-like pathology, but that APOE genotype plays an important role in responsiveness.

Impaired insulin signaling and diet-induced type 3 diabetes pathophysiology increase amyloid β expression in the Drosophila model of Alzheimer's disease

Compelling evidence has strongly linked unregulated sugar levels to developing Alzheimer's disease, suggesting Alzheimer's to be ‘diabetes of the brain or ‘type 3 diabetes. Insulin resistance contributes to the pathogenesis of Alzheimer's disease due to uncontrolled and unchecked blood glucose, though the interrelatedness between Alzheimer's disease and type 2 diabetes is debatable. Here we describe the consequences of inducing type 3 diabetes by feeding Drosophila on a high sucrose diet, which effectively mimics the pathophysiology of diabetes. A high sucrose diet increases glycogen and lipid accumulation. Inducing type 3 diabetes worsened neurodegeneration and accelerated disease progression in Drosophila expressing the Alzheimer's Familial Arctic mutation. High sucrose milieu also negatively affected locomotor ability and reduced the lifespan in the Alzheimer's disease model of Drosophila. The results showed that creating diabetic conditions by using insulin receptor (InR) knockdown in the eyes of Drosophila led to a degenerative phenotype, indicating a genetic interaction between the insulin signaling pathway and Alzheimer's disease. The expression of PERK reflects disruption in the endoplasmic reticulum homeostasis due to amyloid-β (Aβ) under a high sucrose diet. These observations demonstrated an association between type 3 diabetes and Alzheimer's disease, and that a high sucrose environment has a degenerating effect on Alzheimer's disease condition.

The Icelandic Mutation (APP-A673T) Is Protective against Amyloid Pathology In Vivo.

A previous epidemiological study in Northern Europe showed that the A673T mutation (Icelandic mutation) in the amyloid precursor protein gene (APP) can protect against Alzheimer's disease (AD). While the effect of the A673T mutation on APP processing has been investigated primarily in vitro, its in vivo impact has not been evaluated. This is mainly because most existing AD mouse models carry the Swedish mutation. The Swedish and Icelandic mutations are both located near the β-cleavage site, and each mutation is presumed to have the opposite effect on β-cleavage. Therefore, in the AD mouse models with the Swedish mutation, its effects could compete with the effects of the Icelandic mutation. Here, we introduced the A673T mutation into App knock-in mice devoid of the Swedish mutation (AppG-F mice) to avoid potential deleterious effects of the Swedish mutation and generated AppG-F-A673T mice. APP-A673T significantly downregulated β-cleavage and attenuated the production of Aβ and amyloid pathology in the brains of these animals. The Icelandic mutation also reduced neuroinflammation and neuritic alterations. Both sexes were studied. This is the first successful demonstration of the protective effect of the Icelandic mutation on amyloid pathology in vivo. Our findings indicate that specific inhibition of the APP-BACE1 interaction could be a promising therapeutic approach. Alternatively, the introduction of the disease-protective mutation such as APP-A673T using in vivo genome editing technology could be a novel treatment for individuals at high risk for AD, such as familial AD gene mutation carriers and APOE ε4 carriers.