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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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

AbstractObjective: 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]

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]

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]

Disease-modifying therapies for Alzheimer's disease (AD) are likely to be most beneficial when initiated in the presymptomatic phase. To track the benefit of such interventions, fluid biomarkers are of great importance, with neurofilament light chain protein (NfL) showing promise for monitoring neurodegeneration and predicting cognitive outcomes. Here, we update and complement previous findings from the Dominantly Inherited Alzheimer Network Observational Study by using matched cross-sectional and longitudinal cerebrospinal fluid (CSF) and plasma samples from 567 individuals, allowing timely comparative analyses of CSF and blood trajectories across the entire disease spectrum. CSF and plasma trajectories were similar at presymptomatic stages, discriminating mutation carriers from non-carrier controls 10-20 years before the estimated onset of clinical symptoms, depending on the statistical model used. However, after symptom onset the rate of change in CSF NfL continued to increase steadily, whereas the rate of change in plasma NfL leveled off. Both plasma and CSF NfL changes were associated with grey-matter atrophy, but not with Aβ-PET changes, supporting a temporal decoupling of Aβ deposition and neurodegeneration. These observations support NfL in both CSF and blood as an early marker of neurodegeneration but suggest that NfL measured in the CSF may be better suited for monitoring clinical trial outcomes in symptomatic AD patients. This study supports neurofilament light chain protein (NfL) in both cerebrospinal fluid (CSF) and blood as an early marker of neurodegeneration in Alzheimer's disease but suggests that NfL in CSF may be better suited than blood for monitoring clinical trial outcomes in symptomatic patients. [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]

Combinational therapies provoking cell death are of major interest in oncology. Combining TORC2 kinase inhibition with the radiomimetic drug Zeocin results in a rapid accumulation of double-strand breaks (DSB) in the budding yeast genome. This lethal Yeast Chromosome Shattering (YCS) requires conserved enzymes of base excision repair. YCS can be attenuated by eliminating three N-glycosylases or endonucleases Apn1/Apn2 and Rad1, which act to convert oxidized bases into abasic sites and single-strand nicks. Adjacent lesions must be repaired in a step-wise fashion to avoid generating DSBs. Artificially increasing nuclear actin by destabilizing cytoplasmic actin filaments or by expressing a nuclear export-deficient actin interferes with this step-wise repair and generates DSBs, while mutants that impair DNA polymerase processivity reduce them. Repair factors that bind actin include Apn1, RFA and the actin-dependent chromatin remodeler INO80C. During YCS, increased INO80C activity could enhance both DNA polymerase processivity and repair factor access to convert clustered lesions into DSBs. Shimada et al. show that uncoordinated repair by base excision repair generates a lethal accumulation of DNA double-strand breaks at clustered lesions. Rapid conversion of oxidative DNA damage into fragmented chromosomes stems from TORC2 inhibition. [ABSTRACT FROM AUTHOR]

Loss of cytosolic actin filaments upon TORC2 inhibition triggers chromosome fragmentation in yeast, which results from altered base excision repair of Zeocin-induced lesions. To find the link between TORC2 kinase and this yeast chromosome shattering (YCS) we performed phosphoproteomics. YCS-relevant phospho-targets included plasma membrane-associated regulators of actin polymerization, such as Las17, the yeast Wiscott-Aldrich Syndrome protein. Induced degradation of Las17 was sufficient to trigger YCS in presence of Zeocin, bypassing TORC2 inhibition. In yeast, Las17 does not act directly at damage, but instead its loss, like TORC2 inhibition, raises nuclear actin levels. Nuclear actin, in complex with Arp4, forms an essential subunit of several nucleosome remodeler complexes, including INO80C, which facilitates DNA polymerase elongation. Here we show that the genetic ablation of INO80C activity leads to partial YCS resistance, suggesting that elevated levels of nuclear G-actin may stimulate INO80C to increase DNA polymerase processivity and convert single-strand lesions into double-strand breaks. Here the authors reveal that TORC2 inhibition and the rapid degradation of Las17/WASP elevates G-actin levels in the yeast nucleus which are responsible for altered long-patch base excision repair of clustered lesions, generating massive chromosome fragmentation. [ABSTRACT FROM AUTHOR]

AbstractObjective: 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: The assessment of serum neurofilament light chain (sNfL) is increasingly significant in the field of neurology. In multiple sclerosis (MS), it proves valuable as a marker for monitoring disease activity and treatment response. Objective: To compare the Simoa and Lumipulse platforms for measuring sNfL and to establish age‐specific reference ranges within a substantial cohort of individuals diagnosed with MS. Methods: Two hundred sixty‐one sNfL measurements from a cohort of 229 MS patients were analyzed with Simoa and Lumipulse. Reference ranges for sNfL were established for three age groups (18–39 years, 40–59 years, and > 60 years) selecting data from 166 patients with stable relapsing–remitting MS. Results: While sNfL levels correlated between assays, Lumipulse exhibited values higher than Simoa. Passing–Bablok's analysis confirmed linearity between the two datasets, and the Bland–Altman comparison further supported the agreement between the methods. Analyzing reference ranges for sNfL across three age groups in stable RRMS patients revealed significant differences between the groups on each of the platforms. Although the values followed the same trend, each technology utilized distinct reference ranges. Conclusion: Simoa and Lumipulse platforms proved equally effective in monitoring patients with MS. The enhanced accessibility of the Lumipulse platform facilitates the expansion of research on sNfL as a biomarker for monitoring MS, thus offering promising opportunities for broader accessibility and advancement in this field. [ABSTRACT FROM AUTHOR]

As a structural protein, keratin is mainly expressed in epithelial cells and skin appendages to provide mechanical support and external resistance. The keratin family has a total of 54 members, which are divided into type I and type II. Two types of keratins connect to each other to form keratin intermediate filaments and participate in the construction of the cytoskeleton. K18 is a non-hair keratin, which is widely expressed in simple epithelial tissues with its partner, K8. Compared with mechanical support, K8/K18 pairs play more important roles in biological regulation, such as mediating anti-apoptosis, regulating cell cycle progression, and transmitting signals. Mutations in K18 can cause a variety of non-neoplastic diseases of the visceral epithelium. In addition, the expression levels of K18 are frequently altered in various epithelial-derived tumors, especially adenocarcinomas, which suggests that K18 may be involved in tumorigenesis. Due to the specific expression pattern of K18 in tumor tissues and its serum level reflecting tumor cell death, apply K18 to diagnose tumors and predict its prognosis have the potential to be simple and effective alternative methods. However, these potential roles of K18 in tumors have not been fully summarized. In this review, we focus on the relationship between K18 and epithelial-derived tumors, discuss the value of K18 as a diagnostic and prognostic marker, and summarize the interactions of K18 with various related proteins in tumorigenesis, with examples of simple epithelial tumors such as lung, breast, liver, and gastrointestinal cancers. [ABSTRACT FROM AUTHOR]

Background: We report the first case of findings suggestive of progressive multifocal leukoencephalopathy and immune restitution syndrome (PML-IRIS) in a patient with multiple sclerosis receiving ozanimod preceded by an unexpected increase in the serum neurofilament light-chain (sNfL) levels. Case report: A 57-year-old-woman treated with ozanimod for the last 8 years presented, during surveillance MRI, with findings compatible with PML-IRIS. Overt clinical symptoms were absent. sNfL levels increased 4 months earlier and peaked at presentation. Lymphocyte count reached nadir of 330/mL at 8 months earlier. Conclusion: The case illustrates the utility of sNfL levels for PML surveillance in patients receiving immunosuppressors. [ABSTRACT FROM AUTHOR]

Intermediate filaments (IFs) represented by a diverse range of proteins, are one of the three main cytoskeleton components in different types of animal cells. IFs provide mechanical strength to cells and help position the nucleus and organelles in the cell. Desmin is an IF protein typical of muscle cells, while vimentin, which has a similar structure, is expressed in many mesenchymal cells. Both proteins are synthesized during myogenesis and regeneration of damaged muscle tissue and form a mixed IF network. Both desmin and vimentin regulate mitochondrial activity, including mitochondrial localization and maintenance of mitochondrial membrane potential, in the corresponding cells, but the role of mixed IFs in the control of mitochondrial functions remains unclear. To investigate how a simultaneous presence of these proteins affects mitochondrial membrane potential, we used BHK21 cells expressing both vimentin and desmin IFs. Expression of vimentin or desmin individually or both proteins simultaneously was suppressed using gene knockout and/or RNA interference. It was found that disruption of biosynthesis of either vimentin or desmin did not affect the mitochondrial membrane potential, which remained unchanged compared to cells expressing both proteins. Simultaneous abolishment of both proteins resulted in a 20% reduction in the mitochondrial membrane potential, indicating that both vimentin and desmin play an equally important role in its maintenance. [ABSTRACT FROM AUTHOR]

Background: Neurological symptoms are common in acute mountain sickness (AMS); however, the extent of neuroaxonal damage remains unclear. Neurofilament light chain (NfL) is an established blood biomarker for neuroaxonal damage. Objective: To investigate whether plasma (p) NfL levels increase after simulated altitude exposure, correlate with the occurrence of AMS, and might be mitigated by preacclimatization. Methods: Healthy subjects were exposed to simulated high altitude (4500 m) by the use of a normobaric hypoxic chamber at the University of Innsbruck two times, that is, within Cycle 1 (C1) over 12 h, and within Cycle 2 (C2) for another 12 h but with a random assignment to prior acclimatization or sham acclimatization. Before each cycle (measurement [M] 1 and 3) and after each cycle (M2 and M4), clinical data (arterial oxygen saturation [SaO2], heart rate, and Lake Louise AMS score [LLS]) and plasma samples were collected. pNfL was measured using single‐molecule array (Simoa) technique. Results: pNfL levels did not significantly change within each study cycle, but increased over the total study period (M1: 4.57 [3.34–6.39], M2: 4.58 [3.74–6.0], M3: 5.64, and M4: 6.53 [4.65–7.92] pg/mL, p < 0.001). Subjects suffering from AMS during the study procedures showed higher pNfL levels at M4 (6.80 [6.19–8.13] vs. 5.75 [4.17–7.35], p = 0.048), a higher total pNfL increase (2.88 [1.21–3.48] vs. 0.91 [0.53–1.48], p = 0.022) compared to subjects without AMS. An effect of preacclimatization on pNfL levels could not be observed. Conclusions: pNfL increases alongside exposure to simulated altitude and is associated with AMS. [ABSTRACT FROM AUTHOR]

Background: Biomarkers of neuronal and axonal damage (serum neurofilament light (sNfL) and serum glial fibrillary acidic protein (sGFAP)) may provide insight into the aetiology of natalizumab wearing-off symptoms (WoSs). Objectives: We investigated the longitudinal association between and predictive value of sNfL and sGFAP and the occurrence of WoS in MS patients treated with natalizumab. Methods: We performed longitudinal measurements of sNfL and sGFAP in NEXT-MS trial participants who completed a questionnaire about WoS. Results: A total of 364 participants were included. In total, 55.5% presented with WoS and 44.5% without WoS during natalizumab treatment. Longitudinal analyses showed no association between sNfL and sGFAP levels and WoS at any timepoint. Biomarker levels at baseline did not predict first-time WoS occurrence. Conclusion: Acute and chronic neuronal and axonal damage are most likely not the underlying cause of WoS. [ABSTRACT FROM AUTHOR]

Background and objectives: Serum neurofilament light (sNfL) is a biomarker for neuro-axonal damage in multiple sclerosis (MS). Clinical implementation remains limited. We investigated the impact of implementation on clinical decisions using questionnaires at the MS Center Amsterdam, a tertiary outpatient clinic. Methods: sNfL assessments were added to routine clinical practice (August 2021–December 2022). Before and after the results, clinicians filled in questionnaires on context of testing, clinical decisions, certainty herein, expectation of magnetic resonance imaging (MRI) activity, urgency, and motivation to receive the sNfL result and perceived value of sNfL. Results: sNfL was assessed in 166 cases (age 41 ± 12 years, 68% female, 64% disease-modifying therapy (DMT) use) for the following contexts: "DMT monitoring" (55%), "new symptoms" (18%), "differential diagnosis" (17%), and "DMT baseline" (11%). Clinical decisions changed in 19.3% of cases post-disclosure, particularly in context "new symptoms" (38%) and with higher sNfL levels (β = 0.03, p = 0.04). Certainty increased (p = 0.004), while expectation of MRI activity decreased with disclosure of low sNfL levels (p = 0.01). Motivation was highest in context "differential diagnosis" (p < 0.001); perceived value and urgency were highest in context "new symptoms" (p = 0.02). Conclusion: In this study, sNfL implementation had considerable impact on clinical decision-making and certainty herein. Standard implementation may complement patient care but warrants caution and more exploration in diverse clinical settings [ABSTRACT FROM AUTHOR]

Background: Elevated neurofilament light chain (NfL) levels are associated with worse prognosis in Guillain–Barré syndrome (GBS). Our objectives were to determine the utility of serum NfL (sNfL), cerebrospinal fluid (CSF)/serum NfL ratio and NfL index as prognostic and diagnostic biomarkers for GBS. Methods: We measured NfL in serum and/or CSF obtained from 96 GBS patients between 1989 and 2014 in western Sweden. The sNfL Z-scores, NfL ratios and NfL indices were calculated. Outcome was determined with the GBS disability scale (GBSDS) at 3 and 12 months. NfL parameters in GBS were compared with healthy controls (HC), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS). Results: The sNfL Z-score was higher for GBSDS > 2 at 3 months (median [IQR], 3.5 ng/L [3.2–4.0], vs 2.6 [1.7–3.4], p = 0.008) and at 12 months (3.6 ng/L [3.5–3.8] vs 2.6 [1.8–3.5], p = 0.049). NfL ratio and index were not associated with outcome. The area under the curve (AUC) for sNfL Z-score was 0.76 (95% CI 0.58–0.93, p < 0.0001) for GBSDS > 2 at 3 months. NfL ratio and index were lower in GBS than HC, MS, and ALS. The AUC for the NfL ratio was 0.66 (95% CI 0.55–0.78, p = 0.0018) and for the NfL index 0.86 (95% CI 0.78–0.93, p < 0.0001). Discussion: Our results confirm sNfL as prognostic biomarker for GBS and the precision was improved using the age-adjusted sNfL Z score. NfL index and Qalb are potential diagnostic biomarkers for GBS. [ABSTRACT FROM AUTHOR]

Proteasome inhibitors have been applied to anticancer therapy by accumulating toxic misfolded proteins. However, chemical inactivation of proteasome generates aggresome, a Vimentin cage-enclosed subcellular structure quarantining HDAC6-Dynein-transported misfolded proteins before the protein toxicants are degraded by autophagy. Hence, aggresome may attenuate proteasome inhibitor drug-induced cytotoxicity. To solve the problem, it is imperative to characterize how cells assemble aggresome. By examining aggresomes in six cell lines, A549 cells were selectively studied for their bigger cell size and moderate aggresome-forming activity. Aggresome grew in size upon continuous exposure of A549 cells to proteasome inhibitor MG132 and reached a mature size around the 16th to 24th hour of treatment. Mechanistic studies revealed that NF-кB translocated to the nucleus in MG132-treated cells, and chemical activation or knockdown of NF-кB enhanced or prohibited aggresome assembly. Further analyses showed that NF-кB upregulated HDAC6, and HDAC6 maintained the Vimentin cage by interacting with Vimentin p72, a key modification of the intermediate filament contributing to aggresome formation. Remarkably, chemical inactivation of NF-кB synergized MG132-induced cell mortality. All the findings suggest that NF-кB dictates aggresome assembly via upregulating HDAC6, and NF-кB inhibitor may serve as a potential drug potentiating proteasome inhibitor medicine-induced cytotoxicity during the treatment of cancer cells. NEW & NOTEWORTHY: The study reveals a new mechanism guiding MG132-triggered aggresome formation. NF-кB is quickly activated upon exposure to MG132, and NF-кB upregulates the misfolded protein recognizing factor HDCA6. In addition to collecting misfolded proteins, HDAC6 also binds Vimentin and maintains the Vimentin cage, which quarantines toxic misfolded proteins and protects cells from being toxified by those protein toxicants. Therapeutically, chemical inactivation of NF-кB synergizes MG132-induced cytotoxicity, providing a new strategy to defeat cancers. [ABSTRACT FROM AUTHOR]

Small Heat Shock Proteins are considered as the first line of defense when proteostasis fails. Among them, αB-crystallin is expressed in striated muscles in which it interacts with desmin intermediate filaments to stabilize them, maintaining cytoskeleton's integrity and muscular functionalities. Desmin is a key actor for muscle health; its targeting by αB-crystallin is thus crucial, especially in stress conditions. αB-crystallin is phosphorylated and O-GlcNAcylated. Its phosphorylation increases consecutively to various stresses, correlated with its recruitment for cytoskeleton's safeguarding. However, phosphorylation as unique signal for cytoskeleton translocation remains controversial; indeed, O-GlcNAcylation was also proposed to be involved. Thus, there are still some gaps for a deeper comprehension of how αB-crystallin functions are finely regulated by post-translational modifications. Furthermore, desmin also bears both post-translational modifications; while desmin phosphorylation is closely linked to desmin intermediates filaments turnover, it is unclear whereas its O-GlcNAcylation could impact its proper function. In the herein paper, we aim at identifying whether phosphorylation and/or O-GlcNAcylation are involved in αB-crystallin targeting towards cytoskeleton in proteotoxic stress induced by proteasome inhibition in C2C12 myotubes. We demonstrated that proteotoxicity led to αB-crystallin's phosphorylation and O-GlcNAcylation patterns changes, both presenting a dynamic interplay depending on protein subfraction. Importantly, both post-translational modifications showed a spatio-temporal variation correlated with αB-crystallin translocation towards cytoskeleton. In contrast, we did not detect any change of desmin phosphorylation and O-GlcNAcylation. All together, these data strongly support that αB-crystallin phosphorylation/O-GlcNAcylation interplay rather than changes on desmin is a key regulator for its cytoskeleton translocation, preserving it towards stress. [Display omitted] • Small Heat Shock Proteins (sHSPs) are the first line of defense when proteostasis failed in stressful conditions. • The MG132-induced proteotoxicity modifies O-GlcNAcylation/phosphorylation patterns of αB-crystallin. • The MG132-induced proteotoxicity does not modify the O-GlcNAcylation/phosphorylation patterns of desmin. • Phosphorylation/O-GlcNAcylation of αB-crystallin spatio-temporally varies along proteotoxic stress. • Phosphorylation/O-GlcNAcylation interplay is a key regulator of αB-crystallin cytoskeleton translocation. [ABSTRACT FROM AUTHOR]

Complex neurophysiological and morphologic experiments require suitable animal models for investigation. The rabbit is one of the most successful models for studying spinal cord functions owing to its substantial size. However, achieving precise surgical access to specific spinal regions requires a thorough understanding of the spinal cord's cytoarchitectonic structure and its spatial relationship with the vertebrae. The comprehensive anatomo–neurochemical atlases of the spinal cord are invaluable for attaining such insight. While such atlases exist for some rodents and primates, none exist for rabbits. We have developed a spinal cord atlas for rabbits to bridge this gap. Utilizing various neurochemical markers—including antibodies to NeuN, calbindin 28 kDa, parvalbumin, choline acetyltransferase, nitric oxide synthase, and non-phosphorylated heavy-chain neurofilaments (SMI-32 antibody)—we present the visualization of diverse spinal neuronal populations, various spinal cord metrics, stereotaxic maps of transverse slices for each spinal segment, and a spatial map detailing the intricate relationship between the spinal cord and the vertebrae across its entire length. [ABSTRACT FROM AUTHOR]

Summary: Style penetration by pollen tubes is essential for reproductive success, a process requiring canonical Rab5s in Arabidopsis. However, functional loss of Arabidopsis Vps9a, the gene encoding for guanine nucleotide exchange factor (GEF) of Rab5s, did not affect male transmission, implying the presence of a compensation program or redundancy.By combining genetic, cytological, and molecular approaches, we report that Arabidopsis Vps9b is a pollen‐preferential gene, redundantly mediating pollen tube penetration of style with Vps9a.Vps9b is functionally interchangeable with Vps9a, whose functional distinction results from distinct expression profiles.Functional loss of Vps9a and Vps9b results in the mis‐targeting of Rab5‐dependent tonoplast proteins, defective vacuolar biogenesis, disturbed distribution of post‐Golgi vesicles, increased cellular turgor, cytosolic acidification, and disrupted organization of actin microfilaments (MF) in pollen tubes, which collectively lead to the failure of pollen tubes to grow through style. [ABSTRACT FROM AUTHOR]

Background: Approximately 7% of the males exhibit reduced fertility; however, the regulatory genes and pathways involved remain largely unknown. TBC1 domain family member 21 (TBC1D21) contains a conserved RabGAP catalytic domain that induces GDP/GTP exchange to inactivate Rabs by interacting with microtubules. We previously reported that Tbc1d21‐null mice exhibit severe sperm tail defects with a disrupted axoneme, and that TBC1D21 interacts with RAB10. However, the pathological mechanisms underlying the Tbc1d21 loss‐induced sperm tail defects remain unknown. Results: Murine sperm from wild‐type and Tbc1d21‐null mice were comparatively analyzed using proteomic assays. Over 1600 proteins were identified, of which 15 were significantly up‐regulated in Tbc1d21‐null sperm. Notably, several tektin (TEKT) family proteins, belonging to a type of intermediate filament critical for stabilizing the microtubular structure of cilia and flagella, were significantly up‐regulated in Tbc1d21−/− sperm. We also found that TBC1D21 interacts with TEKT1. In addition, TEKT1 co‐localized with RAB10 during sperm tail formation. Finally, we found Tbc1d21‐null sperm exhibited abnormal accumulation of TEKT1 in the midpiece region, accompanied by disrupted axonemal structures. Conclusions: These results reveal that TBC1D21 modulates TEKTs protein localization in the axonemal transport system during sperm tail formation. Key Findings: In this study, we found that the TEKT family proteins, roles of stabilizing the microtubules, are involved in Tbc1d21‐null caused sperm‐tail defects through proteomic assay. [ABSTRACT FROM AUTHOR]

Recent literature suggests that markers of neuroaxonal damage, such as neurofilaments and tau protein, might serve as potential biomarkers for ALS. We conducted this systematic review and meta-analysis study to compare cerebrospinal fluid (CSF) and blood levels of total tau (t-tau), phosphorylated tau (p-tau), amyloid beta peptide 42 (Abeta-42), and neurofilaments in ALS patients and controls. A systematic search of Cochrane Library, PubMed, Embase, and ISI Web of Science was conducted on March 18, 2022, and updated on January 26, 2023. Observational studies that compared the concentrations of neurofilament light chain (NfL), neurofilament heavy chain (NFH), t-tau, p-tau, or Abeta-42 in CSF or peripheral blood of ALS patients and controls were included. Data from relevant studies were independently extracted and screened for quality using a standard tool, by at least two authors. Meta-analysis was conducted when a minimum of 3 studies reported the same biomarker within the same biofluid. A total of 100 studies were eligible for at least one meta-analysis. CSF and blood levels of NfL (standardized mean difference (SMD) [95% CI]; CSF: 1.46 [1.25–1.68]; blood: 1.35 [1.09–1.60]) and NFH (CSF: 1.32 [1.13–1.50], blood: 0.90 [0.58–1.22]) were significantly higher in ALS patients compared with controls. The pooled differences between ALS patients and controls were not significant for CSF t-tau, blood t-tau, and CSF Abeta-42, but CSF p-tau was lower in ALS patients (-0.27 [-0.47- -0.07]). Significantly decreased p-tau/t-tau ratios were found in ALS patients compared with controls (-0.84 [-1.16- -0.53]). Heterogeneity was considerable in most of our meta-analyses. CSF and blood neurofilament levels, as well as the CSF p-tau/t-tau ratio, might be potential candidates for improving ALS diagnosis. Further research is warranted to better understand the underlying mechanisms and the clinical implications of these biomarker alterations. [ABSTRACT FROM AUTHOR]

Keratin intermediate filaments confer structural stability to epithelial tissues, but the reason this simple mechanical function requires a protein family with 54 isoforms is not understood. During skin wound healing, a shift in keratin isoform expression alters the composition of keratin filaments. If and how this change modulates cellular functions that support epidermal remodeling remains unclear. We report an unexpected effect of keratin isoform variation on kinase signal transduction. Increased expression of wound-associated keratin 6A, but not of steady-state keratin 5, potentiated keratinocyte migration and wound closure without compromising mechanical stability by activating myosin motors to increase contractile force generation. These results substantially expand the functional repertoire of intermediate filaments from their canonical role as mechanical scaffolds to include roles as isoform-tuned signaling scaffolds that organize signal transduction cascades in space and time to influence epithelial cell state. [Display omitted] • During skin wound healing, the isoform composition of keratin filaments changes • Wound-associated keratin isoforms organize cellular signals to activate myosin • Keratin isoform-dependent signaling is separable from canonical mechanical function Nanes et al. explore why the seemingly simple mechanical function of keratin intermediate filaments requires a protein family with 54 isoforms. They find that skin wound healing triggers a change in keratin isoform expression not to alter force resistance but to organize signals activating myosin and promoting cell motility. [ABSTRACT FROM AUTHOR]

Nemaline myopathy (NM) is a genetic muscle disease, primarily caused by mutations in the NEB gene (NEB‐NM) and with muscle myosin dysfunction as a major molecular pathogenic mechanism. Recently, we have observed that the myosin biochemical super‐relaxed state was significantly impaired in NEB‐NM, inducing an aberrant increase in ATP consumption and remodelling of the energy proteome in diseased muscle fibres. Because the small‐molecule Mavacamten is known to promote the myosin super‐relaxed state and reduce the ATP demand, we tested its potency in the context of NEB‐NM. We first conducted in vitro experiments in isolated single myofibres from patients and found that Mavacamten successfully reversed the myosin ATP overconsumption. Following this, we assessed its short‐term in vivo effects using the conditional nebulin knockout (cNeb KO) mouse model and subsequently performing global proteomics profiling in dissected soleus myofibres. After a 4 week treatment period, we observed a remodelling of a large number of proteins in both cNeb KO mice and their wild‐type siblings. Nevertheless, these changes were not related to the energy proteome, indicating that short‐term Mavacamten treatment is not sufficient to properly counterbalance the metabolically dysregulated proteome of cNeb KO mice. Taken together, our findings emphasize Mavacamten potency in vitro but challenge its short‐term efficacy in vivo. Key points: No cure exists for nemaline myopathy, a type of genetic skeletal muscle disease mainly derived from mutations in genes encoding myofilament proteins.Applying Mavacamten, a small molecule directly targeting the myofilaments, to isolated membrane‐permeabilized muscle fibres from human patients restored myosin energetic disturbances.Treating a mouse model of nemaline myopathy in vivo with Mavacamten for 4 weeks, remodelled the skeletal muscle fibre proteome without any noticeable effects on energetic proteins.Short‐term Mavacamten treatment may not be sufficient to reverse the muscle phenotype in nemaline myopathy. [ABSTRACT FROM AUTHOR]

Platelets are critical mediators of hemostasis and thrombosis. Platelets circulate as discs in their resting form but change shape rapidly upon activation by vascular damage and/or soluble agonists such as thrombin. Platelet shape change is driven by a dynamic remodeling of the actin cytoskeleton. Actin filaments interact with the protein myosin, which is phosphorylated on the myosin light chain (MLC) upon platelet activation. Actin-myosin interactions trigger contraction of the actin cytoskeleton, which drives platelet spreading and contractile force generation. Filamin A (FLNA) is an actin cross-linking protein that stabilizes the attachment between subcortical actin filaments and the cell membrane. In addition, FLNA binds multiple proteins and serves as a critical intracellular signaling scaffold. Here, we used platelets from mice with a megakaryocyte/platelet-specific deletion of FLNA to investigate the role of FLNA in regulating platelet shape change. Relative to controls, FLNA-null platelets exhibited defects in stress fiber formation, contractile force generation, and MLC phosphorylation in response to thrombin stimulation. Blockade of Rho kinase (ROCK) and protein kinase C (PKC) with the inhibitors Y27632 and bisindolylmaleimide (BIM), respectively, also attenuated MLC phosphorylation; our data further indicate that ROCK and PKC promote MLC phosphorylation through independent pathways. Notably, the activity of both ROCK and PKC was diminished in the FLNA-deficient platelets. We conclude that FLNA regulates thrombin-induced MLC phosphorylation and platelet contraction, in a ROCK- and PKC-dependent manner. [ABSTRACT FROM AUTHOR]