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Actin filaments play an essential role in the process of oocyte maturation and completion of meiosis. However, whether the localization of F-actin in the ooplasm is associated with normal completion of the second meiotic division remains unclear. Mitochondrial distribution is another important parameter correlating directly with MII oocyte capacity to finalize meiosis. Our objective was to examine the role of actin microfilaments in the distribution of mitochondria and, respectively, Metaphase II (MII) oocytes meiotic potential. We show monoclonal antibody-mediated inhibition of actin polymerization in young mouse oocytes, reduction of the amount of F-actin, and induction of mitochondrial clustering induced by antibody treatment. Similar phenotype, even in untreated eggs, was observed in in vitro oocyte aging experiments. Observed changes correlate with reduced ability of MII oocytes to extrude the second polar body and form the pronuclei. Changes in colocalization of F-actin and mitochondria likely resulted from disturbed cytoskeleton architecture. The perturbations in the amount of F-actin and its distribution largely coincide with mitochondrial redistribution. Based on these data, we suggest actin microfilament's participation in redistribution of mitochondria during MII oocyte aging in vitro. Accordingly, patterning of F-actin is indicative of high rate of the completed second meiotic division. These results help evaluating oocyte's quality and choosing optimal time between placement into culture and in vitro fertilization. [Display omitted] • Mitochondria distribution is an indication of the competence of MII oocyte. • Microfilaments participate in redistribution of mitochondria in mouse MII oocyte. • F-actin and mitochondrial localization changes during oocyte aging in vitro. • F-actin is important in finalizing of meiosis II. • F-actin distribution can be used as a marker for assessment of oocyte's quality. [ABSTRACT FROM AUTHOR]

The purpose was to investigate the changes in cytosolic Ca2+ and force output during post-tetanic potentiation (PTP) during pre-fatigue and during prolonged low-frequency force depression (PLFFD) following fatigue. Intact single myofibers from the flexor digitorum brevis of mice were electrically stimulated to record force (n = 8) and free cytosolic Ca2+ concentration ([Ca2+]c) with FURA-2 (n = 6) at 32 °C. Initially, force and [Ca2+]c were measured during brief (350 ms) trains of stimuli at 30, 50, 70, and 200 Hz at ~ 2 s intervals (Force-frequency protocol, FFP). Then, a conditioning stimulus (CS) of six 120 Hz stimuli, separated by ~ 3 s, was used to induce PTP, immediately followed by an FFP. Myofiber fatigue was produced by 150 Hz trains every 3 s until peak force decayed 70% of the initial. Thirty minutes after the fatigue, the CS was repeated to assess the effect of PTP on force and [Ca2+]c during PLFFD. The CS in unfatigued myofibers induced PTP as the submaximal force was enhanced and accompanied by increased peak [Ca2+]c with no change in myofilament Ca2+ sensitivity. After fatigue, PLFFD was due to lowered peak [Ca2+]c. Inducing PTP during PLFFD enhanced submaximal force primarily through greater peak [Ca2+]c, mitigating the submaximal force deficits. Despite the impaired force during PLFFD, myofibers remained sensitive to PTP, and this mitigated the submaximal force deficits through increased peak [Ca2+]c without a change in myofilament Ca2+ sensitivity. Therefore, force adjustments of intact single myofibers due to activation history are principally accomplished by opposing adjustments in [Ca2+]c. [ABSTRACT FROM AUTHOR]

Parkinson's Disease (PD) is characterized by the aggregation and accumulation of α-synuclein (α-syn), along with abnormally high levels of α-syn phosphorylation at the serine 129 site (pSer 129 α-syn, p-α-syn). However, the mechanisms underlying the extensive phosphorylation at the serine 129 site in the pathogenesis of PD, as well as the role of p-α-syn in the process, remain unclear. Furthermore, though α-syn could bind to VAPB and loosen Endoplasmic Reticulum (ER)-mitochondria associations by disrupting VAPB-PTPIP51 tethers, whether and how the phosphorylation of α-syn at the serine 129 site regulates VAPB-PTPIP51 interactions, remains unclear. Herein, Co-Immunoprecipitation and Mass Spectrometry (CO-IP/MS) studies were preformed to identify and compare the Protein-Protein Interactions (PPIs) of phosphorylated and total α-syn in the midbrains of Thy1-SNCA transgenic mice. We further performed CO-IP and Molecular Dynamics (MD) simulation assays to confirm the influence of α-syn phosphorylation on the aforementioned interactions. Additionally, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to annotate the functional features of the common interacting proteins of p-α-syn and VAPB. The potential downstream proteins were further verified via CO-IP. According to the CO-IP and MD results, phosphorylation at the serine 129 site of α-syn increased VAPB-PTPIP51 interactions, and α-syn interacted directly with PTPIP51. Furthermore, functional and pathway enrichment analyses revealed that the common interacting proteins of p-α-syn and VAPB were significantly involved in protein binding, metal ion binding, structural constituent of the cytoskeleton, the intermediate filament cytoskeleton, and microtubule organization processes. Moreover, our findings confirmed the interactions of potential downstream target proteins (CLTC, CAMK2A, ATP1A3, and TUBB4B) with p-α-syn and VAPB. These findings collectively elucidate the structural underpinnings of serine 129 phosphorylation regulates the interaction between α-syn and both VAPB and PTPIP51. We hope that these findings will provide valuable insights into the role and regulatory mechanisms of serine 129 phosphorylation in the pathogenesis of pertinent diseases. [ABSTRACT FROM AUTHOR]

Replication and genome encapsidation of many negative-sense RNA viruses take place in virus-induced membraneless organelles termed viral factories (VFs). Although liquid properties of VFs are believed to control the transition from genome replication to nucleocapsid (NC) assembly, VF maturation and interactions with the cellular environment remain elusive. Here, we apply in situ cryo-correlative light and electron tomography to follow NC assembly and changes in VF morphology and their liquid properties during Ebola virus infection. We show that viral NCs transition from loosely packed helical assemblies in early VFs to compact cylinders that arrange into highly organized parallel bundles later in infection. Early VFs associate with intermediate filaments and are devoid of other host material but become progressively accessible to cellular components. Our data suggest that this process is coupled to VF solidification, loss of sphericity, and dispersion and promotes cytoplasmic exposure of NCs to facilitate their transport to budding sites. [Display omitted] • Cryo-ET reveals the molecular architecture of Ebola virus replication compartments • Loosely coiled nucleocapsids transition to compact cylinders forming bundles • Nucleocapsid assembly drives dispersion of viral factories promoting viral egress • Intermediate filaments associate with and are critical for virus factory formation High-resolution imaging reveals that areas within the host cell cytoplasm, where viral proteins accumulate, undergo significant structural and physical transformations over the course of the Ebola virus life cycle. The changes to these "viral factories" drive the replication and spread of Ebola viruses in the host. [ABSTRACT FROM AUTHOR]

Background: In amyotrophic lateral sclerosis (ALS), neurofilament light chain (NfL) was introduced as a prognostic biomarker. More recently, NfL values can be shared on the patient's ALS app. Also, the ALS functional rating scale (ALSFRS-R) is an established patient-reported assessment of disease progression. The scale can be obtained during clinic visits or remotely. However, few systematic data are available on the patients' perception of prognostic information about NfL and ALSFRS-R and the remote sharing of these data. Methods: In a multicenter study, 149 ALS patients were assessed for their perception of shared information about NfL and ALSFRS-R using an investigator-designed survey and established questionnaires. The recommendation of NfL and ALSFRS-R to fellow patients was assessed using the Net Promoter Score (NPS). Burden by shared information was investigated in two distinct settings: (1) clinic information when receiving results on NfL and/or ALSFRS-R during clinic visits and (2) remote information about NfL values and self-rating of the ALSFRS-R via the ALS app. General anxiety was measured by the Fear of Progression Questionnaire – Short Form (FoP-Q-SF). Results: Information about NfL and ALSFRS-R, respectively (n = 149), were regarded as relevant for patients themselves (75.2% and 77.2%) and for research (98% and 96%). The NPS showed a high recommendation rate for NfL (+ 21) and ALSFRS-R (+ 26). Only a minority of patients perceived shared information about NfL as burdensome, with a lower burden in the clinic setting (n = 1, 4.2%) than in the remote setting (n = 8, 12%; p = 0.015). Remote digital assessment of the ALSFRS-R was well received, with a reported burden in 9.8% (n = 9) of the participants. The FoP-Q-SF revealed fear of progression in 40% of the respondents (n = 60). Conclusions: This study underscored the relevance of information about NfL and ALSFRS-R from the patient's perspective. Furthermore, patients proved to appreciate the relevance of this data for ALS research. Sharing information about NfL or ALSFRS-R was rarely perceived as burdensome even in a remote setting using the ALS app. These findings pave the way for further development of the patient-centered approach to sharing prognostic information in ALS. [ABSTRACT FROM AUTHOR]

The coordination of cytoskeletal proteins shapes cell architectures and functions. Age-related changes in cellular mechanical properties have been linked to decreased cellular and tissue dysfunction. Studies have also found a relationship between mitochondrial function and the cytoskeleton. Cytoskeleton inhibitors impact mitochondrial quality and function, including motility and morphology, membrane potential, and respiration. The regulatory properties of the cytoskeleton on mitochondrial functions are involved in the pathogenesis of several diseases. Disassembly of the axon's cytoskeleton and the release of neurofilament fragments have been documented during neurodegeneration. However, these changes can also be related to mitochondrial impairments, spanning from reduced mitochondrial quality to altered bioenergetics. Herein, we discuss recent research highlighting some of the pathophysiological roles of cytoskeleton disassembly in aging, neurodegeneration, and neuromuscular diseases, with a focus on studies that explored the relationship between intermediate filaments and mitochondrial signaling as relevant contributors to cellular health and disease. [ABSTRACT FROM AUTHOR]

Laminopathies are a broad spectrum of hereditary diseases caused by pathogenic variants of the LMNA gene. Such phenotypic diversity is explained by the function of intermediate filaments encoded by the LMNA gene. We examined a family with an overlapping phenotype of cardiac arrhythmia, cardiomyopathy, limb–girdle muscular dystrophy, and partial lipodystrophy. The cause of the disorder was a novel LMNA(NM_170707.4):c.1488+2T>C variant. The analysis of mRNA extracted from the probands' blood showed a multitude of alternative splicing products, which was the cause of the complex phenotype in affected family members. Aside from that, we used minigene constructs to analyze the c.1488+2T>C variant, as well as other previously described variants affecting the same donor splice site in intron 8 (c.1488+1G>A, c.1488+5G>C, c.1488+5G>A). We demonstrated that these variants result in multiple splicing events, each producing splicing products with varying prevalence. Our experiments suggest that the variety of alternative transcripts contributes to complex phenotypes, while the quantitative ratio of these transcripts influences the varying severity of the disease. [ABSTRACT FROM AUTHOR]

X-linked myotubular myopathy (XLMTM) is a rare congenital myopathy that commonly manifests with liver involvement. In most XLMTM cases, disease-causing variants have been identified in the myotubularin gene (MTM1) on chromosome Xq28, which encodes myotubularin protein (MTM1). The impairment of mitochondrial respiratory chain (MRC) enzyme activity in muscle has been observed in the XLMTM mouse model. Though several reports mentioned possible mechanisms of liver involvement in XLMTM patients and animal models, the precise underlying mechanisms remain unknown, and there is no report focused on mitochondrial functions in hepatocytes in XLMTM. We encountered two patients with XLMTM who had liver involvement. We measured MRC enzyme activities in two muscle biopsy specimens, and one liver specimen from our patients to investigate whether MTM1 variants cause MRC dysfunction and whether mitochondrial disturbance is associated with organ dysfunction. MRC enzyme activities decreased in skeletal muscles but were normal in the liver. In our patients, the impaired MRC enzyme activity found in muscle is consistent with previously reported mechanisms that the loss of MTM1-desmin intermediate filament and MTM1-IMMT (a mitochondrial membrane protein) interaction led to the mitochondrial dysfunction. However, our study showed that liver involvement in XLMTM may not be associated with mitochondrial dysfunction. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the prognostic potential of neurofilament medium chain (NfM) in CSF from patients with ALS and explore its relationship with the extensively studied neurofilament light chain (NfL) and phosphorylated heavy chain (pNfH). Method: CSF levels of NfL, NfM, and pNfH were analyzed in 235 samples from patients with ALS, ALS mimics, and healthy controls in a well-characterized cohort from Karolinska ALS Clinical Research Center in Stockholm, Sweden. NfM levels were analyzed using an antibody-based suspension bead-array and NfL and pNfH levels were measured using ELISA. Clinical data, including ALS Revised Functional Rating Scale (ALSFRS-R), and survival outcomes were utilized for disease progression estimations. Result: Increased NfM levels were observed in patients with ALS compared with mimics and healthy controls. Similarly, higher NfM levels were found in fast compared with slow progressing patients for baseline and longitudinal progression when evaluating both total and subscores of ALSFRS-R. These findings were consistent with the results observed for NfL and pNfH. All three proteins, used individually as well as in combination, showed comparable performance when classifying fast vs slow progressing patients (AUCs 0.78–0.85). For all neurofilaments, higher survival probability was observed for patients with low CSF levels. Conclusion: Based on this cross-sectional study, the prognostic value provided by NfM aligns with the more established markers, NfL and pNfH. Additional investigations with independent cohorts and longitudinal studies are needed to further assess the potential added value of NfM. [ABSTRACT FROM AUTHOR]

Objective: To evaluate correlations between neurofilament (Nf) concentrations and clinical characteristics and disease progression using a large longitudinal dataset from VITALITY-ALS (ClinicalTrials.gov identifier: NCT02496767), a 48-week, randomized, double-blind, placebo-controlled clinical trial of tirasemtiv in people with ALS (pALS). Methods: Plasma was collected at baseline and every 8 weeks thereafter. Results were compared between treatment groups and evaluated by clinical characteristics and over time. Pearson's correlation coefficients (r) were calculated to evaluate associations between Nf concentrations and slow vital capacity (SVC), Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) score, and pre-study/in-study rates of disease progression (psRDP/isRDP). Results: Nf measurements were available from 101 placebo- and 161 tirasemtiv-treated people with ALS (pALS). There were no significant differences in Nf between placebo and tirasemtiv groups at any time point; further analyses grouped all samples. At baseline, Nf concentration did not differ by multiple clinical characteristics. Baseline Nf light chain (NfL) concentration correlated with the psRDP (r = 0.50, p < 0.001) and isRDP (r = 0.53, p < 0.0001). Phosphorylated Nf heavy chain (pNfH) demonstrated a similar, but less robust, pattern of results. Baseline Nf concentration correlated with change in SVC and ALSFRS-R score over time. Plasma pNfH concentration continuously decreased over time. There was no meaningful change in plasma NfL concentration over the study period. Conclusions: In this large longitudinal study, baseline NfL concentration correlated with multiple markers of disease progression. The findings suggest Nfs show promise primarily as prognostic markers for pALS, particularly for those with rapid disease progression. [ABSTRACT FROM AUTHOR]

Background: For clinical implementation of Alzheimer's disease (AD) blood-based biomarkers (BBMs), knowledge of short-term variability, is crucial to ensure safe and correct biomarker interpretation, i.e., to capture changes or treatment effects that lie beyond that of expected short-term variability and considered clinically relevant. In this study we investigated short-term intra- and inter-individual variability of AD biomarkers in the intended use population, memory clinic patients. Methods: In a consecutive sample of memory clinic patients (AD n = 27, non-AD n = 20), blood samples were collected on three separate days within a period of 36 days and analysed for plasma Aβ40, Aβ42, p-tau181, p-tau217, p-tau231, T-tau, neurofilament light (NfL), and glial fibrillary acidic protein (GFAP). We measured intra- and inter-individual variability and explored if the variability could be affected by confounding factors. Secondly, we established the minimum change required to detect a difference between two given blood samples that exceeds intra-individual variability and analytical variation (reference change value, RCV). Finally, we tested if classification accuracy varied across the three visits. Results: Intra-individual variability ranged from ~ 3% (Aβ42/40) to ~ 12% (T-tau). Inter-individual variability ranged from ~ 7% (Aβ40) to ~ 39% (NfL). Adjusting the models for time, eGFR, Hba1c, and BMI did not affect the variation. RCV was lowest for Aβ42/Aβ40 (- ~ 15%/ + ~ 17%) and highest in p-tau181 (- ~ 30/ + ~ 42%). No variation in classification accuracies was found across visits. Conclusion: We found low intra-individual variability, robust to various factors, appropriate to capture individual changes in AD BBMs, while moderate inter-individual variability may give rise to caution in diagnostic contexts. High RCVs may pose challenges for AD BBMs with low fold changes and consequently, short-term variability is important to take into consideration when, e.g., estimating intervention effect and longitudinal changes of AD BBM levels. Trial registration: Clinicaltrials.gov (NCT05175664), date of registration 2021–12-01. [ABSTRACT FROM AUTHOR]

Background: Serum neurofilament light chain (sNfL) is a biomarker for neuro-axonal injury. Objectives: To assess sNfL's utility as a diagnostic marker for Lyme neuroborreliosis (LNB). Methods: We compared serum and CSF NfL levels in LNB patients and age-matched controls. Age-adjusted NfL values were used in receiver operating characteristic (ROC) analysis. Design: Retrospective cohort study. Results: Eighty-six patients (30 LNB, 29 with-, and 27 without neurological disorders) were included. Compared to individuals without neurological disease, LNB patients showed increased serum (median (interquartile range, IQR): 36.3 pg/ml (19.3–112.0) vs 20 pg/ml (12.9–37.3), p < 0.001) and CSF NfL levels (median (IQR): 1000.0 pg/ml (286.0–6471.0) vs 182 pg/ml (99.3–474.0), p < 0.001). NfL concentrations were similar in LNB and other neurological disorders. ROC analysis of age-adjusted sNfL and CSF NfL levels showed areas under the curve of 0.78 (95% confidence interval (CI): 0.66–0.89) and 0.83 (95% CI: 0.71–0.94), respectively. Conclusion: sNfL concentrations lack sufficient diagnostic capability for LNB diagnosis. [ABSTRACT FROM AUTHOR]

Protocadherin 19 (PCDH19) is an adhesion molecule involved in cell-cell interaction whose mutations cause a drug-resistant form of epilepsy, named PCDH19-Clustering Epilepsy (PCDH19-CE, MIM 300088). The mechanism by which altered PCDH19 function drive pathogenesis is not yet fully understood. Our previous work showed that PCDH19 dysfunction is associated with altered orientation of the mitotic spindle and accelerated neurogenesis, suggesting a contribution of altered cytoskeleton organization in PCDH19-CE pathogenesis in the control of cell division and differentiation. Here, we evaluate the consequences of altered PCDH19 function on microfilaments and microtubules organization, using a disease model obtained from patient-derived induced pluripotent stem cells. We show that iPSC-derived cortical neurons are characterized by altered cytoskeletal dynamics, suggesting that this protocadherin has a role in modulating stability of MFs and MTs. Consistently, the levels of acetylated-tubulin, which is related with stable MTs, are significantly increased in cortical neurons derived from the patient's iPSCs compared to control cells, supporting the idea that the altered dynamics of the MTs depends on their increased stability. Finally, performing live-imaging experiments using fluorescence recovery after photobleaching and by monitoring GFP-tagged end binding protein 3 (EB3) "comets," we observe an impairment of the plus-end polymerization speed in PCDH19-mutated cortical neurons, therefore confirming the impaired MT dynamics. In addition to altering the mitotic spindle formation, the present data unveil that PCDH19 dysfunction leads to altered cytoskeletal rearrangement, providing therapeutic targets and pharmacological options to treat this disorder. [ABSTRACT FROM AUTHOR]

Peripherin belongs to heterogeneous class III of intermediate filaments, and it is the only intermediate filament protein selectively expressed in the neurons of the peripheral nervous system. It has been previously discovered that peripherin interacts with proteins important for the endo-lysosomal system and for the transport to late endosomes and lysosomes, such as RAB7A and AP-3, although little is known about its role in the endocytic pathway. Here, we show that peripherin silencing affects lysosomal abundance but also positioning, causing the redistribution of lysosomes from the perinuclear area to the cell periphery. Moreover, peripherin silencing affects lysosomal activity, inhibiting EGFR degradation and the degradation of a fluorogenic substrate for proteases. Furthermore, we demonstrate that peripherin silencing affects lysosomal biogenesis by reducing the TFEB and TFE3 contents. Finally, in peripherin-depleted cells, the autophagic flux is strongly inhibited. Therefore, these data indicate that peripherin has an important role in regulating lysosomal biogenesis, and positioning and functions of lysosomes, affecting both the endocytic and autophagic pathways. Considering that peripherin is the most abundant intermediate filament protein of peripheral neurons, its dysregulation, affecting its functions, could be involved in the onset of several neurodegenerative diseases of the peripheral nervous system characterized by alterations in the endocytic and/or autophagic pathways. [ABSTRACT FROM AUTHOR]

Alterations in mitochondrial function are the linchpin in numerous disease states including in the development of chemotherapyinduced neuropathic pain (CIPN), a major dose-limiting toxicity of widely used chemotherapeutic cytotoxins. In CIPN, mitochondrial dysfunction is characterized by deficits in mitochondrial bioenergetics (e.g., decreased ATP production) that are thought to drive the degeneration of the peripheral nerve sensory axon terminal sensory arbors in the skin (the intraepidermal nerve fibers; IENFs) and induce abnormal spontaneous discharge in peripheral nerve sensory axons. Preserving mitochondrial function is anticipated to prevent CIPN. We have now discovered that the G-protein-coupled receptor, A3 adenosine receptor subtype (A3AR), is expressed on the mitochondrial outer membrane. Ex vivo application of a highly selective A3AR agonist, MRS5980, to saphenous nerve microfilaments harvested from male oxaliplatin-treated rats reversed the loss in ATP production underscoring mitoprotective effects resulting from A3AR activation on mitochondria. Moreover, in vivo administration of A3AR agonists to rats during oxaliplatin treatment was associated with reduced IENF loss and a lower incidence of spontaneous discharge in peripheral afferent axons. These effects are accompanied by improved mitochondrial ATP production in primary afferent sensory axons and overall inhibition of the development of neuropathic pain. These data identify for the first time mitochondrial A3AR and indicate that activation of A3AR protects mitochondrial function in primary afferent sensory axons against chemotherapy-induced neurotoxicity. Repurposing A3AR agonists that are already in clinical trials as anticancer agents as adjunct to chemotherapeutics will address a major unmet medical need for which there are no FDA-approved drugs. [ABSTRACT FROM AUTHOR]

Neurofilament light chain (Nf-L) is a biomarker for axonal damage in human neurology but is understudied in cattle. With this study we wanted to determine Nf-L stability at two different storage temperatures and Nf-L levels in healthy cattle and the relationship with age, evaluate whether Nf-L holds diagnostic potential for neurological disorders, and whether an association exists between Nf-L in serum and in cerebrospinal fluid (CSF). To do this, we measured Nf-L levels in CSF and serum samples from 49 healthy and 75 sick cattle. Storage at −80 °C or −20 °C had no impact on Nf-L concentration. Physiological median Nf-L levels were 6.3 pg/mL (serum) and 414 pg/mL (CSF) in calves and 5.5 pg/mL (serum) and 828 pg/mL (CSF) in adult cattle. There was no association between Nf-L levels in CSF and calf age (r2 0.07, p = 0.13), while a weak association was found for Nf-L in serum (r2 0.26, p = 0.01), and a significant association in adult cattle (CSF, r2 0.69, p = 0.0001; serum, r2 0.68, p = 0.0003). CSF Nf-L levels were higher in samples from animals with degenerative (median Nf-L 49971 pg/mL) and infectious central nervous system (CNS) disorders (median Nf-L, age < 2 months 8863 pg/mL; age 2–12 months 17474 pg/mL; age 1–6 years 3546 pg/mL), CNS anomalies and metabolic/toxic disorders. There was a significant association between CSF Nf-L and serum Nf-L in cattle with neurological disorders (r2 0.2, p = 0.009). Taken together, these findings suggest the potential of Nf-L as a diagnostic tool in cattle neurology. [ABSTRACT FROM AUTHOR]

Background: Traumatic brain injury (TBI) is a leading cause of mortality worldwide and often results in substantial cognitive, motor, and psychological impairments, triggering oxidative stress, neuroinflammation, and neurodegeneration. This study examined the neuroprotective effects of azithromycin (AZI) in TBI. Methods: TBI was induced in rats using the weight-drop method. Subsequently, rats received a daily intraperitoneal (I.P.) dose of AZI (150 mg/kg) for 28 days. Behavioral tests (Morris water maze, rotarod, and open field tests) were performed to assess cognitive and motor functions. Neurochemical analyses included oxidative stress markers (GSH, SOD, MDA, catalase), inflammatory cytokines (TNF-α, IL-1β), apoptotic markers (caspase-3, Bax, Bcl-2), mitochondrial complexes (complex I, II, III, IV, and V), and the transforming growth factor- beta (TGF-β) as a neurofilament marker. Histological evaluations focused on neuronal integrity in the cortex, hippocampus, and striatum. Results: Treatment with AZI significantly facilitated motor and cognitive function recovery in TBI-affected rats. At the molecular level, AZI effectively reduced oxidative stress markers, ameliorated neuroinflammation by decreasing TNF-α, IL-1β, and neuronal apoptosis, and differentially modulated mitochondrial complexes. Histological assessments revealed enhanced neuronal integrity and fewer pathological changes in AZI-treated rats compared to untreated TBI controls. Conclusions: AZI was shown to interfere with several pathways involved in TBI's pathophysiology. While preclinical results are promising, further studies are necessary to establish the long-term safety and efficacy of AZI in a clinical setting. This research supports the potential re-purposing of AZI as a novel treatment strategy for TBI and related neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

Objective: To investigate the longitudinal dynamics of serum glial fibrillary acidic protein (sGFAP) and serum neurofilament light chain (sNfL) levels in people with multiple sclerosis (pwMS) under B‐cell depleting therapy (BCDT) and their capacity to prognosticate future progression independent of relapse activity (PIRA) events. Methods: A total of 362 pwMS (1,480 samples) starting BCDT in the Swiss Multiple Sclerosis (MS) Cohort were included. sGFAP levels in 2,861 control persons (4,943 samples) provided normative data to calculate adjusted Z scores. Results: Elevated sGFAP levels (Z score >1) at 1 year were associated with a higher hazard for PIRA (hazard ratio [HR]: 1.80 [95% CI: 1.17–2.78]; p = 0.0079) than elevated sNfL levels (HR, 1.45 [0.95–2.24], p = 0.0886) in a combined model. Independent of PIRA events, sGFAP levels longitudinally increased by 0.49 Z score units per 10 years follow‐up (estimate, 0.49 [0.29, 0.69], p < 0.0001). In patients experiencing PIRA, sGFAP Z scores were 0.52 Z score units higher versus stable patients (0.52 [0.22, 0.83], p = 0.0009). Different sNfL Z score trajectories were found in pwMS with versus without PIRA (interaction p = 0.0028), with an average decrease of 0.92 Z score units per 10 years observed without PIRA (−0.92 [−1.23, −0.60], p < 0.0001), whereas levels in patients with PIRA remained high. Interpretation: Elevated sGFAP and lack of drop in sNfL after BCDT start are associated with increased risk of future PIRA. These findings provide a rationale for combined monitoring of sNfL and sGFAP in pwMS starting BCDT to predict the risk of PIRA, and to use sGFAP as an outcome in clinical trials aiming to impact on MS progressive disease biology. ANN NEUROL 2025;97:104–115 [ABSTRACT FROM AUTHOR]

Objective: To ascertain the changes of serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) values in relapsing–remitting multiple sclerosis (RRMS) patients treated with ocrelizumab and their association with treatment response. Methods: Multicenter prospective study including 115 RRMS patients initiating ocrelizumab treatment between February 2020 and March 2022 followed during a year. Serum samples were collected at baseline and every 3 months to measure sNfL and sGFAP levels using single-molecule array (SIMOA) technology. Based on age and body mass index, sNfL values were standardized using z-score. NEDA (non-evidence of disease activity)-3 status was defined for patients free of disease activity after a year of follow-up. Inflammation (INFL) was considered when new relapses occurred during follow-up or new MRI lesions were found at 1-year exploration. PIRA (progression independent of relapse activity) was defined as disability progression occurring in the absence of relapses or new MRI activity. Results: After a year on ocrelizumab, 85 patients (73.9%) achieved NEDA-3. Thirty patients did not achieve NEDA: 20 (17.4%) because of INFL and 10 (8.7%) because of PIRA. Of INFL patients, 6 (30.0%) had relapses, and 17 (85.0%) had at least one new MRI lesion at the 12-month examination. At baseline, INFL patients had higher sNfL (p = 0.0003) and sGFAP (p = 0.03) than the NEDA-3 group. PIRA patients mostly exhibited low sNfL and heterogeneous sGFAP levels. After a year, NEDA-3 and INFL patients showed similar decreases in sNfL (p < 0.0001) and sGFAP (p < 0.0001 for NEDA-3 and p = 0.001 for INFL ones). However, the decrease occurred earlier in NEDA-3 patients. Accordingly, sNfL > 1.5 z-score 3 months after ocrelizumab initiation indicated a higher risk of inflammation (OR = 13.6; p < 0.0001). Decrease in sGFAP values occurred later in both groups, with significant reductions observed at 12 months for INFL and 6 and 12 months for NEDA-3. No significant changes in sNfL or sGFAP were observed in PIRA patients. Conclusion: Ocrelizumab induced normalization of sNfL and sGFAP in the majority of NEDA-3 and inflammatory patients but did not cause changes in the PIRA group. Our data suggest that normalization of sNfL and sGFAP is associated with the lack of inflammatory-associated disease progression but it may not affect non-inflammatory PIRA. [ABSTRACT FROM AUTHOR]

Over 400 cyanobacterial genera have been described up to the present. Since the Cambridge Rules (https://www.iapt‐taxon.org/historic/1935.htm: Rendle 1935), a type species (generitype) must be specified at the time of description for a new genus to be validly described. Even though we have entered a time in which sequencing has become practical and widespread, the basic molecular characterization (e.g., 16S rRNA gene sequence) of most cyanobacterial generitypes is still lacking. About 15 cyanobacterial genera were originally described from Scandinavia. Following a field excursion in which the type or syntype localities for the type species of these genera were visited and sampled, we succeeded in finding three type species from their type or syntype localities: Capsosira brebissonii, Stigonema mamillosum, and Paracapsa siderophila. Epitypes for all three generitypes are herein established. Cells or filaments of C. brebissonii and S. mamillosum were isolated and used for single‐cell/filament PCR amplification of the 16S rRNA gene and subsequent cloning and sequencing of the PCR amplicons. This allows a firm establishment of reference sequences of these two genera, to which morphologically similar taxa can now be compared. Stigonema and Capsosira are shown herein to be sister to Aetokthonos hydrillicola, a cyanobacterium known to cause avian vacuolar myelinopathy in birds, including bald eagles. [ABSTRACT FROM AUTHOR]

In muscle, titin proteins connect myofilaments together and are thought to be critical for contraction, especially during residual force enhancement (RFE) when steady-state force is elevated after an active stretch. We investigated titin's function during contraction using small-angle X-ray diffraction to track structural changes before and after 50% titin cleavage and in the RFE-deficient, mdm titin mutant. We report that the RFE state is structurally distinct from pure isometric contractions, with increased thick filament strain and decreased lattice spacing, most likely caused by elevated titin-based forces. Furthermore, no RFE structural state was detected in mdm muscle. We posit that decreased lattice spacing, increased thick filament stiffness, and increased non-cross-bridge forces are the major contributors to RFE. We conclude that titin directly contributes to RFE. [ABSTRACT FROM AUTHOR]

The flagellar motors of Campylobacter jejuni (C. jejuni) and related Campylobacterota (previously epsilonproteobacteria) feature 100-nm-wide periplasmic "basal disks" that have been implicated in scaffolding a wider ring of additional motor proteins to increase torque, but the size of these disks is excessive for a role solely in scaffolding motor proteins. Here, we show that the basal disk is a flange that braces the flagellar motor during disentanglement of its flagellar filament from interactions with the cell body and other filaments. We show that motor output is unaffected when we shrink or displace the basal disk, and suppressor mutations of debilitated motors occur in flagellar-filament or cell-surface glycosylation pathways, thus sidestepping the need for a flange to overcome the interactions between two flagellar filaments and between flagellar filaments and the cell body. Our results identify unanticipated co-dependencies in the evolution of flagellar motor structure and cell-surface properties in the Campylobacterota. [Display omitted] • The C. jejuni flagellar motor has an extra-large basal disk • The basal disk promotes filament unwrapping from the cell surface • Reduction of cell-surface glycosylation is required for swimming without a basal disk The human pathogen Campylobacter jejuni (C. jejuni) has a larger, more complex flagellar motor than that of the model organism Salmonella typhimurium. In Cohen and Drobnič et al. the authors demonstrate that one function of the added complexity of the motor is to promote efficient directional switching while swimming and to prevent cell clumping. [ABSTRACT FROM AUTHOR]

Cardiometabolic syndromes including diabetes and obesity are associated with occurrence of heart failure with diastolic dysfunction. There are no specific treatments for diastolic dysfunction, and therapies to manage symptoms have limited efficacy. Understanding of the cardiomyocyte origins of diastolic dysfunction is an important priority to identify new therapeutics. The investigative goal was to experimentally define in vitro stiffness properties of isolated cardiomyocytes derived from rodent hearts exhibiting diastolic dysfunction in vivo in response to dietary induction of cardiometabolic disease. Male mice fed a high fat/sugar diet (HFSD vs. control) exhibited diastolic dysfunction (echo E/e′ Doppler ratio). Intact paced cardiomyocytes were functionally investigated in three conditions: non‐loaded, loaded and stretched. Mean stiffness of HFSD cardiomyocytes was 70% higher than control. E/e′ for the HFSD hearts was elevated by 35%. A significant relationship was identified between in vitro cardiomyocyte stiffness and in vivo dysfunction severity. With conversion from the non‐loaded to loaded condition, the decrement in maximal sarcomere lengthening rate was more accentuated in HFSD cardiomyocytes (vs. control). With stretch, the Ca2+ transient decay time course was prolonged. With increased pacing, cardiomyocyte stiffness was elevated, yet diastolic Ca2+ elevation was attenuated. Our findings show unequivocally that cardiomyocyte mechanical dysfunction cannot be detected by analysis of non‐loaded shortening. Collectively, these findings demonstrate that a component of cardiac diastolic dysfunction in cardiometabolic disease is derived from cardiomyocyte stiffness. Differential responses to load, stretch and pacing suggest that a previously undescribed alteration in myofilament–Ca2+ interaction contributes to intrinsic cardiomyocyte stiffness in cardiometabolic disease. Key points: Understanding cardiomyocyte stiffness components is an important priority for identifying new therapeutics for diastolic dysfunction, a key feature of cardiometabolic disease.In this study cardiac function was measured in vivo (echocardiography) for mice fed a high‐fat/sugar diet (HFSD, ≥25 weeks). Performance of intact isolated cardiomyocytes derived from the same hearts was measured during pacing under non‐loaded, loaded and stretched conditions in vitro.Calibrated cardiomyocyte stretches demonstrated that stiffness (stress/strain) was elevated in HFSD cardiomyocytes in vitro and correlated with diastolic dysfunction (E/e′) in vivo. HFSD cardiomyocyte Ca2+ transient decay was prolonged in response to stretch. Stiffness was accentuated with pacing increase while the elevation in diastolic Ca2+ was attenuated.Data show unequivocally that cardiomyocyte mechanical dysfunction cannot be detected by analysis of non‐loaded shortening.These findings suggest that stretch‐dependent augmentation of the myofilament–Ca2+ response during diastole partially underlies elevated cardiomyocyte stiffness and diastolic dysfunction of hearts of animals with cardiometabolic disease. [ABSTRACT FROM AUTHOR]

Reaction system (RS) belongs to a type of qualitative computing model inspired by biochemical reactions taking place inside biological cells. It concerns more the interactions and causality among reactions rather than concrete concentrations of chemical entities. Many biochemical processes and models can be represented in the form of reaction systems so that complex relations and ultimate products of a variety of reactions can be revealed qualitatively. The reaction system works in parallel mode. Software simulation of this kind of model may suffer from the penalty of inefficient parallelism for the limited performance of CPU/GPU, especially for the simulation of large-scale models. Considering potential applications of reaction systems in disease diagnoses and in drug developments, hardware implementation of reaction systems provides a better way to accelerate computations involved. In this paper, an FPGA implementation method of a reaction system called RSFIM is proposed. Two small-scale models, i.e., the reaction system of intermediate filaments self-assembly and heat shock response, are implemented on FPGA, achieving a computing speed of 2 × 10 8 steps per second. For large-scale models, the ErbB reaction system is implemented, obtaining a speedup of 7.649 × 10 4 compared with its highest performance GPU simulation so far. The reaction system binary counter, which is a quantitative model, is also implemented by the Boolean explanation of the qualitative character of the reaction system. FPGA implementation of reaction systems opens a novel research line to speed up the simulations of reaction systems and other biological models in the perspective of parallel digital circuits. [ABSTRACT FROM AUTHOR]

ABSTRACT Cyanobacteria developed oxygenic photosynthesis and represent the phylogenetic ancestors of chloroplasts. The model strain Anabaena sp. strain PCC 7120 grows as filaments of communicating cells and can form heterocysts, cells specialized for N2 fixation. In the Anabaena genome, ORF all2390 is annotated as encoding a SulA homolog, but sequence similarity to SulA of model bacteria is insignificant. We generated strains that lacked or overexpressed all2390, both of which showed instances of increased cell size, and observed that purified All2390 protein interfered with the in vitro polymerization of FtsZ. Heterocyst frequency diminished by all2390 inactivation and increased by all2390 overexpression. Overexpression retarded the dismantlement of Z‐ring structures that determines commitment in the differentiating cells. Thus, All2390 can influence cell division affecting heterocyst differentiation. An All2390‐GFP fusion protein localized to the thylakoid membranes including the honeycomb membranes, which harbor photosynthetic complexes, in the heterocyst polar regions. Notably, all2390 expression strongly increased under high light, conditions under which growth of the null mutant is compromised. Thus, All2390 appears essential for adaptation to high light conditions. We named All2390 ThyD to reflect its thylakoidal localization and its dual role in cell division dynamics and acclimation of thylakoid membranes to increased light intensity. [ABSTRACT FROM AUTHOR]

Introduction: Essential tremor (ET) is a highly prevalent neurological disease. At present, there are no clinical biomarkers. Neurofilament light (NfL) has been studied as a measure of neuronal damage in a considerable number of neurological disorders. There have been three studies of ET, and results are inconsistent. Methods: Forty ET cases were enrolled in a research study between February and November 2023 and compared to two control groups from study 1 (n = 41) and study 2 (n = 185). Total tremor score was a measure of the severity of action tremor. Blood samples were analyzed for serum NfL level on the Simoa® platform using an NF-Light™ kit as a marker of axonal injury. Results: Serum log NfL levels were higher in ET cases than controls in study 1 (p < 0.001) and study 2 (p < 0.001). In a multivariate linear regression model, ET cases (p = 0.03) and individuals of older age (p < 0.001) had higher serum log NfL levels than controls (combined in studies 1 and 2). There was no association in ET cases between serum log NfL level and total tremor score (Pearson’s r = 0.08, p = 0.63). Conclusion: This new study further validates the elevation in serum NfL levels in ET, now representing the third study to do so. In combination, the converging data suggest that there is an overall increase in serum NfL levels in ET. The demonstration of elevated serum levels of NfL in ET adds an additional piece of evidence that there is neuronal damage in ET. [ABSTRACT FROM AUTHOR]

Neurofilaments (NFs) are multisubunit, bottlebrush-shaped intermediate filaments abundant in the axonal cytoskeleton. Each NF subunit contains a long intrinsically disordered tail domain, which protrudes from the NF core to form a "brush" surrounding each NF. Precisely how the tails' variable charge patterns and repetitive phosphorylation sites mediate their conformation within the brush remains an open question in axonal biology. We address this problem by grafting recombinant NF tail protein constructs NF-Light, -Medium, and -Heavy (NFL, NFM, and NFH) to surfaces, yielding protein brushes of defined stoichiometry that can be phosphorylated in vitro. Atomic force microscopy measurements reveal that brush height depends on composition monotonically but not always linearly for binary NFL:NFM or NFL:NFH systems, and that NFM-based brushes are highly extended, while brushes incorporating the much larger NFH are surprisingly compact even after multisite phosphorylation. Complementary self-consistent field theory (SCFT) predicts multilayer brush morphologies for NFM and phosphorylated NFH brushes. Further experiments and SCFT analysis with designed mutants reveal that N-terminal negative charges in the NFH tail repel phosphorylated residues to generate the multilayer morphology, while the C-terminal charge-neutral region contributes to multilayer brush morphology but not total brush height. Charge-shuffled NFM variants show that charge segregation promotes brush collapse near physiological ionic strengths. Collectively, this study supports a role for NFM in establishing a dynamic range for NF brush conformation, lending insight into previous in vitro and in vivo findings. More broadly, this work establishes a platform for dissecting contributions of disordered protein sequence to conformation at interfaces. [ABSTRACT FROM AUTHOR]

Plectin is a cytoskeletal linker of intermediate filaments, encoded by the PLEC gene. Recently, plectin mutations have been identified in a pair of siblings with progressive familial intrahepatic cholestasis. Here, we reported two unrelated infants with plectinopathy causing cholestatic jaundice with novel variants in the PLEC gene. Trio exome sequencing identified compound heterozygous variants in the PLEC gene for each patient: c.71‐11768C>T and c.4331G>T (p.Arg1444Leu) in Patient 1, and c.592C>T (p.Arg198Trp) and c.4322G>A (p.Arg1441His) in Patient 2. Immunofluorescence staining of liver samples from both patients revealed scattered signals of plectin in the cytoplasm of hepatocytes and reduced colocalization of plectin and cytokeratin 8. This study not only underscores the involvement of plectin in cholestasis but also highlights the utility of exome sequencing as a powerful diagnostic tool in identifying genetic underpinnings of infantile cholestasis. [ABSTRACT FROM AUTHOR]

Background/Objectives: KRT23 was recently discovered as an epithelial-specific intermediate filament protein in the type I keratin family. Many studies have underlined keratin's involvement in several biological processes as well as in the pathogenesis of different diseases. Specifically, KRT23 was reported to affect the structural integrity of epithelial cells and to trigger cellular signaling leading to the onset of cancer. The aim of this study is to characterize a novel mechanism based on miR-195-5p/KRT23 in colorectal cancer. Methods: KRT23 mRNA and protein expression were characterized in FFPE sections from patients with CRC. The effects of miR-195-5p on KRT23 expression at the mRNA and protein levels were assessed by transient transfection experiments with mimic and inhibitor molecules. Cell attachment/detachment, migration, invasion, clone formation, and apoptosis were evaluated in human CRC cell lines after miR-195-5p mimic transfection. Results: We identified KRT23 as a putative target of miR-195-5p, a microRNA that we previously demonstrated to be reduced in CRC. We have proved the KRT23 expression deregulation in the tumoral section compared to adjacent normal mucosa in patients with CRC, according to the data derived from the public repository. We proved that the gain of miR-195-5p decreased the KRT23 expression. Conversely, we demonstrated that the inhibition of miR-195-5p led to an increase in KRT23 expression levels. We have demonstrated the in vitro effectiveness of miR-195-5p on CRC progression and that the in vivo intraperitoneal delivery of miR-195-5p mimic lowered colonic KRT23 mRNA and protein expression. Conclusions: These findings highlight a new regulatory mechanism by miR-195-5p in CRC affecting the keratin intermediate filaments and underline the miR-195-5p potential clinical properties. [ABSTRACT FROM AUTHOR]

Natalizumab is a highly effective therapy for multiple sclerosis (MS). The aim of this study was to evaluate serum neurofilament light chain (sNfL) and serum glial fibrillary acidic protein (sGFAP) in patients with relapsing–remitting MS treated with Natalizumab. sNfL and sGFAP were analyzed at baseline, 6 and 12 months post treatment using the single-molecule array (SiMoA) technique. We recruited matched healthy controls for comparison. The study included 54 patients, with a median age of 33 years (Interquartile range (IQR), 29–41), with 32 women (60%) and 76 healthy controls. A decrease in sNfL was observed at 6 (67%, p = 0.005) and 12 (72%, p < 0.0001) months compared to baseline. After two years, six patients experienced evidence of disease activity (EDA-3). The remaining ones had no evidence of disease activity (NEDA-3). NEDA-3 presented a remarkable reduction in sNfL (p < 0.0001) and sGFAP (p = 0.01) after 6 months of treatment that continued to be observed after 12 months compared to baseline. EDA-3 only reached a significant decrease in sNfL after 12 months; there were no significant changes in sGFAP values. Natalizumab leads to a decrease in sNfL, which is higher and occurs earlier in NEDA-3 patients. Patients also showed a significant reduction in sGFAP levels, which was not observed in the EDA-3 group. [ABSTRACT FROM AUTHOR]

Nuclear dysmorphia, characterized by crumpled or lobulated polymorphic nuclear shapes, has been used as an index for the malignant grades of certain cancers. The expression of vimentin, a type-III intermediate filament protein, is a hallmark of the epithelial-to-mesenchymal transition. However, it remains unclear whether vimentin is involved in cancer cell nuclear dysmorphia. In this study, we found that vimentin intermediate filaments (VIFs) frequently accumulated at the concave of dysmorphic nucleus in breast cancer MDA-MB231 cells. Depletion of vimentin apparently restored the nuclear shape of the cells, which was devastated by re-expression of vimentin, but not its assembly-defective Y117D mutant. Depletion of plectin, a cytoskeletal linker, partially prevented the perinuclear accumulation of VIFs and concomitantly restored the nuclear shape of the cells. In addition, depletion of vimentin in lung cancer A549 cells largely prevented nuclear dysmorphia during the epithelial-to-mesenchymal transition induced by TGFb. Moreover, we found that VIF-mediated nuclear dysmorphia led to defects in DNA repair. Together, our results unveil a novel role of VIFs in cancer cell nuclear dysmorphia, which is associated with genome instability. [ABSTRACT FROM AUTHOR]

Ferroptosis is a type of regulated cell death driven by irondependent accumulation of lipid peroxidation, exhibiting unique morphological changes. While actin microfilaments are crucial for various cellular processes, including morphogenesis, motility, endocytosis, and cell death, their role in ferroptosis remains unclear. Here, our study reveals that actin microfilaments undergo remodeling and disassembly during ferroptosis. Interestingly, inhibitors that target actin microfilament remodeling do not affect cell sensitivity to ferroptosis, with the exception of CK-666 and its structural analog CK-636. Mechanistically, CK-666 attenuates ferroptosis independently of its canonical function in inhibiting the Arp2/3 complex. Further investigation revealed that CK-666 modulates the ferroptotic transcriptome, prevents lipid degradation, and diminishes lipid peroxidation. In addition, CK-666 does not impact the labile iron pool within cells nor does the inhibition of FSP1 impacts its antiferroptosis activity. Notably, the results of DPPH assay and liposome leakage assay suggest that CK-666 mitigates ferroptosis by directly eliminating lipid peroxidation. Importantly, CK-666 significantly ameliorated renal ischemia-reperfusion injury and ferroptosis in renal tissue, underscoring its potential therapeutic impact. [ABSTRACT FROM AUTHOR]

Although cytoplasmic intermediate filaments (cIFs) are essential for cell physiology, the molecular and cell functional consequences of cIF disturbances are poorly understood. Identifying defaults in cell function-controlled tissue homeostasis and understanding the interrelationship between specific cIFs and distinct cell functions remain key challenges. Using an RNAi-based mechanistic approach, we connected the impairment of cell-inherent cIFs with molecular and cell functional consequences, such as proliferation and differentiation. To investigate cIF disruption consequences in the oral epithelium, different cell transformation stages, originating from alcohol-treated oral gingival keratinocytes, were used. We found that impairment of keratin (KRT) KRT5, KRT14 and vimentin (VIM) affects proliferation and differentiation, and modulates the chromatin status. Furthermore, cIF impairment reduces the expression of nuclear integrity participant lamin B1 and the terminal keratinocyte differentiation marker involucrin (IVL). Conversely, impairment of IVL reduces cIF expression levels, functionally suggesting a regulatory interaction between cIFs and IVL. The findings demonstrate that the impairment of cIFs leads to imbalances in proliferation and differentiation, both of which are essential for tissue homeostasis. Thus, targeted impairment of cIFs appears promising to investigate the functional role of cIFs on cell-dependent tissue physiology at the molecular level and identifies putative interactions of cIFs with epithelial differentiation. [ABSTRACT FROM AUTHOR]

Neurofilaments are structural proteins found in the cytoplasm of neurons, particularly in axons, providing structural support and stability to the axon. They consist of multiple subunits, including NF-H, NF-M, and NF-L, which form long filaments along the axon's length. Neurofilaments are crucial for maintaining the shape and integrity of neurons, promoting axonal transport, and regulating neuronal function. They are part of the intermediate filament (IF) family, which has approximately 70 tissue-specific genes. This diversity allows for a customizable cytoplasmic meshwork, adapting to the unique structural demands of different tissues and cell types. Neurofilament proteins show increased levels in both cerebrospinal fluid (CSF) and blood after neuroaxonal damage, indicating injury regardless of the underlying etiology. Precise measurement and long-term monitoring of damage are necessary for determining prognosis, assessing disease activity, tracking therapeutic responses, and creating treatments. These investigations contribute to our understanding of the importance of proper NF composition in fundamental neuronal processes and have implications for neurological disorders associated with NF abnormalities along with its alteration in different animal and human models. Here in this review, we have highlighted various neurological disorders such as Alzheimer's, Parkinson's, Huntington's, Dementia, and paved the way to use neurofilament as a marker in managing neurological disorders. [ABSTRACT FROM AUTHOR]

Objective: Neurofilament light chains (NfL) and phosphorylated neurofilament heavy chains (pNfH), established as diagnostic and prognostic biomarkers in hospital‐based amyotrophic lateral sclerosis (ALS) cohorts, are now surrogate markers in clinical trials. This study extends their evaluation to a population level, with the aim of advancing their full establishment and assessing the transferability of biomarker findings from controlled cohorts to real‐world ALS populations. Methods: We measured serum NfL and pNfH levels in all ALS patients (n = 790) and general population controls (n = 570) with available baseline samples participating in the epidemiological ALS Registry Swabia, providing platform‐specific (ELLA™) reference data and Z‐scores for controls, as well as reference data, disease‐specific Z‐scores and longitudinal data in ALS. We evaluated the diagnostic and prognostic utility of neurofilaments and quantified the impact of ALS‐related factors and non‐ALS confounders. Results: Neurofilaments showed high diagnostic and prognostic utility at the population level, with NfL superior to pNfH. The novel concept of a population‐based ALS Z‐score significantly improved the prognostic utility compared to absolute raw values. Both biomarkers increased more strongly with age in controls than in ALS, and age adjustment improved diagnostic accuracy. Our data show that disease progression rates, ALS phenotype, body mass index (BMI), and renal function need to be considered when interpreting neurofilament levels; longitudinal neurofilament levels were generally stable in individual patients, especially when adjusted for age and baseline levels. Interpretation: Population‐based assessment enhances the utility of particularly serum NfL as a diagnostic and prognostic biomarker in ALS and improves the translation of findings from controlled cohorts to real‐world populations. ANN NEUROL 2024;96:1040–1057 [ABSTRACT FROM AUTHOR]

The potential for combining serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) levels to predict worsening disability in multiple sclerosis remains underexplored. We aimed to investigate whether sNfL and sGFAP values identify distinct subgroups of patients according to the risk of disability worsening and their response to disease-modifying treatments (DMTs). This multicentre study, conducted across 13 European hospitals, spanned from 15 July 1994 to 18 August 2022, with follow-up until 26 September 2023. We enrolled patients with multiple sclerosis who had serum samples collected within 12 months from disease onset and before initiating DMTs. Multivariable regression models were used to estimate the risk of relapse-associated worsening (RAW), progression independent of relapse activity (PIRA) and Expanded Disability Status Scale (EDSS) score of 3. Of the 725 patients included, the median age was 34.2 (interquartile range, 27.6–42.4) years, and 509 patients (70.2%) were female. The median follow-up duration was 6.43 (interquartile range, 4.65–9.81) years. Higher sNfL values were associated with an elevated risk of RAW [hazard ratio (HR) of 1.45; 95% confidence interval (CI) 1.19–1.76; P < 0.001], PIRA (HR of 1.43; 95% CI 1.13–1.81; P = 0.003) and reaching an EDSS of 3 (HR of 1.55; 95% CI 1.29–1.85; P < 0.001). Moreover, higher sGFAP levels were linked to a higher risk of achieving an EDSS score of 3 (HR of 1.36; 95% CI 1.06–1.74; P = 0.02) and, in patients with low sNfL values, to PIRA (HR of 1.86; 95% CI 1.01–3.45; P = 0.04). We also examined the combined effect of sNfL and sGFAP levels. Patients with low sNfL and sGFAP values exhibited a low risk of all outcomes and served as a reference. Untreated patients with high sNfL levels showed a higher risk of RAW, PIRA and reaching an EDSS of 3. Injectable or oral DMTs reduced the risk of RAW in these patients but failed to mitigate the risk of PIRA and reaching an EDSS of 3. Conversely, high-efficacy DMTs counteracted the heightened risk of these outcomes, except for the risk of PIRA in patients with high sNfL and sGFAP levels. Patients with low sNfL and high sGFAP values showed an increased risk of PIRA and achieving an EDSS of 3, which remained unchanged with either high-efficacy or other DMTs. In conclusion, evaluating sNfL and sGFAP levels at disease onset in multiple sclerosis might identify distinct phenotypes associated with diverse immunological pathways of disability acquisition and therapeutic response. [ABSTRACT FROM AUTHOR]

Background: Growing evidence supports the value of neurofilament light (NfL) as a prognostic biomarker in premanifest Huntington's disease (HD). To date, however, there has been no longitudinal study exceeding 3 years examining either its serial dynamics or predictive power in HD. We aimed to conduct the first such study. Methods: Serum NfL was sampled using ultrasensitive immunoassay at four timepoints across a 14-year period in a cohort of HD gene carriers (n = 21) and controls (n = 14). Gene carriers were premanifest at baseline. Clinical features of HD were evaluated by Unified Huntington's Disease Rating Scale (UHDRS TMS), Montreal Cognitive Assessment (MoCA), Trail A/B task, Symbol Digit Modalities Task and semantic/phonemic fluency tasks. Results: 14/21 HD gene carriers converted to prodromal or manifest disease by the final timepoint ("converters"). At baseline and each subsequent timepoint, NfL levels were higher in converters than in non-converters and controls (p = < 0.001–0.03, ηp2 = 0.25–0.66). The estimated rate of change in NfL was higher in converters than in non-converters (p = 0.03) and controls (p = 0.001). Baseline NfL was able to discriminate converters from non-converters (area under curve = 1.000, p = 0.003). A higher rate of change in NfL was predictive of more severe motor (UHDRS-TMS p = 0.007, β = 0.711, R2 = 0.468) and cognitive deficits (MoCA p = 0.007, β = − 0.798, R2 = 0.604; Trail B, p = 0.007, β = 0.772, R2 = 0.567; phonemic fluency p = 0.035, β = − 0.632, R2 = 0.345). Conclusions: Our data suggest that (1) NfL longitudinal dynamics in premanifest/transitional HD are non-constant; rising faster in those closer to disease onset, and (2) NfL can identify individuals at risk of conversion to manifest disease and predict clinical trajectory, > 10 years from disease onset. [ABSTRACT FROM AUTHOR]

Simple Summary: Vimentin, a type III protein of intermediate filaments (IFs) characteristic of mesenchymal cells, was found in neural cells, together with neurofilaments in the early stages of their differentiation or recovery after damage. Since in the fibroblasts, vimentin IFs were implicated in the maintenance of mitochondrial membrane potential, we decided to explore their possible impact on the mitochondria in neural cells. The CAD cell line offers a convenient model to investigate neuritogenesis, which is stimulated by the simple removal of serum from the culture medium. The results of this study show that, indeed, the deletion of vimentin in these cells led to a decrease in the membrane potential of mitochondria, though other IFs and neurofilaments remained. Furthermore, the restoration of vimentin IFs in the knockout cell line by the human vimentin caused an increase in the mitochondrial potential. Neural precursor cells contain two types of intermediate filaments (IFs): neurofilaments consisting of three IV type proteins and vimentin belonging to the type III IF proteins that disappear at the later stages of differentiation. The involvement of vimentin in neurogenesis was demonstrated earlier; however, the role of its temporary expression in neurons is not clear. We showed that the vimentin IFs that interacted with mitochondria maintained their membrane potential at the appropriate level, and thus, ensured their proper function. We examined the dependence of the mitochondrial membrane potential on the expression of vimentin in a CAD catecholaminergic neuronal cell line that was actively dividing in full culture media but stopped growing and started developing neurites when the serum was removed. Using the CRISPR Cas9 system to knock out the vimentin gene in these cells, we investigated the impact of this on the mitochondrial membrane potential. Our data show that the deletion of the vimentin IFs led to a decrease in the level of the mitochondrial potential. When the vimentin network in these cells was reconstituted by transfection with a plasmid that encoded human protein, the level of the potential was restored. Interestingly, mutated vimentin with a disrupted mitochondria-binding site had no such effect. Our data point to vimentin as a possible target in some neurological pathologies. [ABSTRACT FROM AUTHOR]

The cytoskeleton is essential for mechanical signal transduction and autophagy. However, few studies have directly demonstrated the contribution of the cytoskeleton to mechanical stress‐induced autophagy. We explored the role of the cytoskeleton in response to compressive force‐induced autophagy in human cell lines. Inhibition and activation of cytoskeletal polymerization using small chemical molecules revealed that cytoskeletal microfilaments are required for changes in the number of autophagosomes, whereas microtubules play an auxiliary role in mechanical stress‐induced autophagy. The intrinsic mechanical properties and special intracellular distribution of microfilaments may account for a large proportion of compression‐induced autophagy. Our experimental data support that microfilaments are core components of mechanotransduction signals. [ABSTRACT FROM AUTHOR]

Background: Neurofilament light chain (NfL) is a biomarker of neuronal injury in hereditary ATTR (ATTRv) amyloidosis. However, the correlation between NfL and nerve conduction study (NCS), the standard test for ATTRv neuropathy, has not been investigated. Objective: Elucidate the correlation between NfL and NCS parameters. Methods: 227 serum NfL measurements were performed in 45 ATTRv patients, 5 asymptomatic carriers, and 12 controls. Among them, 177 simultaneous analyses of NCS and NfL were conducted in 45 ATTRv patients. Results: NfL levels of symptomatic patients were significantly higher than those of asymptomatic carriers and controls. Serum NfL levels were correlated with NCS parameters, especially compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes, indicators of axonal damage. CMAP and/or SNAP amplitudes were undetectable in 9 patients (no-amplitude group) due to advanced neuropathy. NfL levels in the no-amplitude group were significantly higher than those in patients with detectable CMAP/SNAP. NfL levels significantly decreased with patisiran, although no significant changes were observed in CMAP and SNAP. Conclusions: NfL levels are found to be correlated with CMAP/SNAP amplitudes. Compared with NCS, NfL can be a more sensitive biomarker for detecting treatment response and active nerve damage even in patients with advanced neuropathy. [ABSTRACT FROM AUTHOR]

The nuclear lamina is a dense network of intermediate filaments beneath the inner nuclear membrane. Composed of A‐type lamins (lamin A/C) and B‐type lamins (lamins B1 and B2), the nuclear lamina provides a scaffold for the nuclear envelope and chromatin, thereby maintaining the structural integrity of the nucleus. A‐type lamins are also found inside the nucleus where they interact with chromatin and participate in gene regulation. Viruses replicating in the cell nucleus have to overcome the nuclear envelope during the initial phase of infection and during the nuclear egress of viral progeny. Here, we focused on the role of lamins in the replication cycle of a dsDNA virus, mouse polyomavirus. We detected accumulation of the major capsid protein VP1 at the nuclear periphery, defects in nuclear lamina staining and different lamin A/C phosphorylation patterns in the late phase of mouse polyomavirus infection, but the nuclear envelope remained intact. An absence of lamin A/C did not affect the formation of replication complexes but did slow virus propagation. Based on our findings, we propose that the nuclear lamina is a scaffold for replication complex formation and that lamin A/C has a crucial role in the early phases of infection with mouse polyomavirus. [ABSTRACT FROM AUTHOR]

Context Neurofilament light chains (sNFLs) increase in patients with diabetes (DM) and are associated with death. Objective This work aimed to examine whether sNFL mediates associations of DM with all-cause mortality and the extent of interaction or joint relations of sNFL and DM with mortality. Methods This population-based cohort study was conducted using the 2013 to 2014 cycle of the National Health and Nutrition Examination Survey. A total of 2071 adults aged 20 to 75 years with sNFL measurements were included. sNFL was lg-transformed (LgNfl). Participants were included whose LgNfl was higher than 1.48 pg/mL or who were diagnosed with DM. All-cause mortality was the primary outcome obtained through linkage to registries. Results During a median follow-up of 6.1years, 85 participants died. Incidence rates (per 1000 person-years [95% CI]) of all-cause mortality were 27.78 (19.98∼35.58) in adults with LgNfl greater than 1.48 pg/mL and DM, 9.01 (1.99∼16.03) in adults with LgNfl greater than 1.48 pg/mL but no DM, 3.07 (1.01∼5.13) in adults with DM and LgNfl less than or equal to 1.48 pg/mL, and 2.21 (1.15∼3.27) in adults without DM and LgNfl less than or equal to 1.48 pg/mL. Significant interaction but not mediation was observed between LgNfl and DM. Compared with adults without DM and LgNfl less than or equal to 1.48 pg/mL, those with DM and LgNfl greater than 1.48 pg/mL had higher risks of all-cause mortality (hazard ratio; 95% CI, 7.06; 3.52∼14.16). Conclusion In general US adults with DM, elevated sNFLs were associated with higher all-cause mortality specifically, supporting an important role of sNFLs in predicting health outcome in individuals with DM. [ABSTRACT FROM AUTHOR]

The document discusses the ultrastructure of aberrant basaloid cells in Idiopathic Pulmonary Fibrosis (IPF), a progressive lung disease with a poor prognosis. The study uses a multiscale imaging approach to analyze the transition from alveolar epithelial type II (AE2) cells to basaloid cells in IPF lungs. Basaloid cells exhibit ultrastructural features of protein biosynthesis and adaptations to mechanical forces, suggesting a trajectory from AE2 cells to basaloid cells, which may play a role in the progression of IPF. The study highlights the importance of understanding the origin and function of aberrant basaloid cells in IPF for potential therapeutic interventions. [Extracted from the article]

Oocyte meiotic maturation includes large-scale chromatin remodeling as well as cytoskeleton and nuclear envelope rearrangements. This review addresses the dynamics of key cytoskeletal proteins (tubulin, actin, vimentin, and cytokeratins) and nuclear envelope proteins (lamin A/C, lamin B, and the nucleoporin Nup160) in parallel with chromatin reorganization in maturing mouse oocytes. A major feature of this reorganization is the concentration of heterochromatin into a spherical perinucleolar rim called surrounded nucleolus or karyosphere. In early germinal vesicle (GV) oocytes with non-surrounded nucleolus (without karyosphere), lamins and Nup160 are at the nuclear envelope while cytoplasmic cytoskeletal proteins are outside the nucleus. At the beginning of karyosphere formation, lamins and Nup160 follow the heterochromatin relocation assembling a new spherical structure in the GV. In late GV oocytes with surrounded nucleolus (fully formed karyosphere), the nuclear envelope gradually loses its integrity and cytoplasmic cytoskeletal proteins enter the nucleus. At germinal vesicle breakdown, lamin B occupies the karyosphere interior while all the other proteins stay at the karyosphere border or connect to chromatin. In metaphase oocytes, lamin A/C surrounds the spindle, Nup160 localizes to its poles, actin and lamin B are attached to the spindle fibers, and cytoplasmic intermediate filaments associate with both the spindle fibers and the metaphase chromosomes. [ABSTRACT FROM AUTHOR]

Objective: To ascertain the changes of serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) values in relapsing–remitting multiple sclerosis (RRMS) patients treated with ocrelizumab and their association with treatment response. Methods: Multicenter prospective study including 115 RRMS patients initiating ocrelizumab treatment between February 2020 and March 2022 followed during a year. Serum samples were collected at baseline and every 3 months to measure sNfL and sGFAP levels using single-molecule array (SIMOA) technology. Based on age and body mass index, sNfL values were standardized using z-score. NEDA (non-evidence of disease activity)-3 status was defined for patients free of disease activity after a year of follow-up. Inflammation (INFL) was considered when new relapses occurred during follow-up or new MRI lesions were found at 1-year exploration. PIRA (progression independent of relapse activity) was defined as disability progression occurring in the absence of relapses or new MRI activity. Results: After a year on ocrelizumab, 85 patients (73.9%) achieved NEDA-3. Thirty patients did not achieve NEDA: 20 (17.4%) because of INFL and 10 (8.7%) because of PIRA. Of INFL patients, 6 (30.0%) had relapses, and 17 (85.0%) had at least one new MRI lesion at the 12-month examination. At baseline, INFL patients had higher sNfL (p = 0.0003) and sGFAP (p = 0.03) than the NEDA-3 group. PIRA patients mostly exhibited low sNfL and heterogeneous sGFAP levels. After a year, NEDA-3 and INFL patients showed similar decreases in sNfL (p < 0.0001) and sGFAP (p < 0.0001 for NEDA-3 and p = 0.001 for INFL ones). However, the decrease occurred earlier in NEDA-3 patients. Accordingly, sNfL > 1.5 z-score 3 months after ocrelizumab initiation indicated a higher risk of inflammation (OR = 13.6; p < 0.0001). Decrease in sGFAP values occurred later in both groups, with significant reductions observed at 12 months for INFL and 6 and 12 months for NEDA-3. No significant changes in sNfL or sGFAP were observed in PIRA patients. Conclusion: Ocrelizumab induced normalization of sNfL and sGFAP in the majority of NEDA-3 and inflammatory patients but did not cause changes in the PIRA group. Our data suggest that normalization of sNfL and sGFAP is associated with the lack of inflammatory-associated disease progression but it may not affect non-inflammatory PIRA. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy (DR) is one of the most common complications of diabetes and induces severe visual impairment worldwide. Endothelial cell dysfunction plays an important role in the pathogenesis of DR. Here, we keep a watchful eye on α/β‐hydrolase domain–containing 1 (ABHD1), a potential regulator in lipid metabolism and neovascularization. Results revealed that ABHD1 expression increased both in retina tissues of DR patients and in high‐glucose–treated human retina endothelial cells. Inhibition of ABHD1 remitted endothelial cell proliferation and migration. And GSEA uncovered that ABHD1 knockdown remits endothelial cell chemotaxis and intermediate filament (IF) might be mediated in the progress by regulating keratin 1 (KRT1) and keratin 2 (KRT2). Therefore, we assume that ABHD1 is concerned with endothelial cell proliferation and migration in DR, consequently leading to pathological neovascularization. The findings may provide a potential therapeutic target for DR. [ABSTRACT FROM AUTHOR]

We explored the association between aerobic capacity (AC) and the skeletal muscle proteome of McArdle (n = 10) and wild‐type (n = 8) mice, as models of intrinsically ‘low’ and ‘normal’ AC, respectively. AC was determined as total distance achieved in treadmill running until exhaustion. The quadriceps muscle proteome was studied using liquid chromatography with tandem mass spectrometry, with the Search Tool for the Retrieval of Interacting Genes/Proteins database used to generate protein–protein interaction (PPI) networks and enrichment analyses. AC was significantly associated (P‐values ranging from 0.0002 to 0.049) with 73 (McArdle) and 61 (wild‐type) proteins (r‐values from −0.90 to 0.94). These proteins were connected in PPI networks that enriched biological processes involved in skeletal muscle structure/function in both groups (false discovery rate <0.05). In McArdle mice, the proteins associated with AC were involved in skeletal muscle fibre differentiation/development, lipid oxidation, mitochondrial function and calcium homeostasis, whereas in wild‐type animals AC‐associated proteins were related to cytoskeleton structure (intermediate filaments), cell cycle regulation and endocytic trafficking. Two proteins (WEE2, THYG) were associated with AC (negatively and positively, respectively) in both groups. Only 14 of the 132 proteins (∼11%) associated with AC in McArdle or wild‐type mice were also associated with those previously reported to be modified by aerobic training in these mice, providing preliminary evidence for a large divergence in the muscle proteome signature linked to aerobic training or AC, irrespective of AC (intrinsically low or normal) levels. Our findings might help to gain insight into the molecular mechanisms underlying AC at the muscle tissue level. [ABSTRACT FROM AUTHOR]

Spontaneous locomotion is a common feature of most metazoan cells, generally attributed to the properties of actomyosin networks. This force-producing machinery has been studied down to the most minute molecular details, especially in lamellipodium-driven migration. Nevertheless, how actomyosin networks work inside contraction-driven amoeboid cells still lacks unifying principles. Here, using stable motile blebs from HeLa cells as a model amoeboid motile system, we imaged the dynamics of the actin cortex at the single filament level and revealed the co-existence of three distinct rheological phases. We introduce "advected percolation," a process where rigidity percolation and active advection synergize, spatially organizing the actin network's mechanical properties into a minimal and generic locomotion mechanism. Expanding from our observations on simplified systems, we speculate that this model could explain, down to the single actin filament level, how amoeboid cells, such as cancer or immune cells, can propel efficiently through complex 3D environments. [Display omitted] • Actin filament density at the cell front controls bleb protrusion • A solid-like actomyosin cortex in the cell middle sterically enables cell propulsion • The material properties of amoeboid cells organize spatially by advected percolation • Stable blebs in adhesive environments can fragment into cytoplasts García-Arcos et al. propose a universal framework for amoeboid migration: actin filaments and myosin motors spatially self-organize and give rise to different material properties in different parts of the cell. A solid-like state in the actin network found in the middle of the cell enables efficient cell propulsion. [ABSTRACT FROM AUTHOR]

From the day we are born, the nervous system is subject to insult, disease and degeneration. Aberrant phosphorylation states in neurofilaments, the major intermediate filaments of the neuronal cytoskeleton, accompany and mediate many pathological processes in degenerative disease. Neuronal damage, degeneration and death can release these internal components to the extracellular space and eventually the cerebrospinal fluid and blood. Sophisticated assay techniques are increasingly able to detect their presence and phosphorylation states at very low levels, increasing their utility as biomarkers and providing insights and differential diagnosis for the earliest stages of disease. Although a variety of studies focus on single or small clusters of neurofilament phosphorylated epitopes, this review offers a wider perspective of the phosphorylation landscape of the neurofilament heavy subunit, a major intermediate filament component in both ageing and disease. [ABSTRACT FROM AUTHOR]

The endoplasmic reticulum (ER) is a dynamic and continuous membrane network with roles in many cellular processes. The importance and maintenance of ER structure and function have been extensively studied in interphase cells, yet recent findings also indicate crucial roles of the ER in mitosis. During mitosis, the ER is remodelled significantly with respect to composition and morphology but persists as a continuous network. The ER interacts with microtubules, actin and intermediate filaments, and concomitant with the mitotic restructuring of all cytoskeletal systems, ER dynamics and distribution change. The ER is a metabolic hub and several examples of altered ER functions during mitosis have been described. However, we lack an overall understanding of the ER metabolic pathways and functions that are active during mitosis. In this Review, we will discuss mitotic changes to the ER at different organizational levels to explore how the mitotic ER, with its distinct properties, might support cell division. [ABSTRACT FROM AUTHOR]