Impaired Activity Research Articles

Rehabilitation Is Associated With Improvements in Post-COVID-19 Sequelae.

Post-COVID-19 syndrome has affected millions of people, with rehabilitation being at the center of non-pharmacologic care. However, numerous published studies show conflicting results due to, among other factors, considerable variation in subject characteristics. Currently, the effects of age, sex, time of implementation, and prior disease severity on the outcomes of a supervised rehabilitation program after COVID-19 remain unknown. This was a non-randomized case-control study. Subjects with post-COVID-19 sequelae were enrolled. Among study participants, those who could attend an 8-week, supervised rehabilitation program composed the intervention group, whereas those who couldn't the control group. Measurements were collected at baseline and 8 weeks thereafter. Study groups (N = 119) had similar baseline measurements. Participation in rehabilitation (n = 47) was associated with clinically important improvements in the 6-min walk test (6MWT) distance, adjusted (for potential confounders) odds ratio (AOR) 4.56 (95% CI 1.95-10.66); 1-min sit-to-stand test, AOR 4.64 (1.88-11.48); Short Physical Performance Battery, AOR 7.93 (2.82-22.26); health-related quality of life (HRQOL) 5-level EuroQol-5D (Visual Analog Scale), AOR 3.12 (1.37-7.08); Montreal Cognitive Assessment, AOR 6.25 (2.16-18.04); International Physical Activity Questionnaire, AOR 3.63 (1.53-8.59); Fatigue Severity Scale, AOR 4.07 (1.51-10.98); Chalder Fatigue Scale (bimodal score), AOR 3.33 (1.45-7.67); Modified Medical Research Council dyspnea scale (mMRC), AOR 4.43 (1.83-10.74); Post-COVID-19 Functional Scale (PCFS), AOR 3.46 (1.51-7.95); and COPD Assessment Test, AOR 7.40 (2.92-18.75). Time from disease onset was marginally associated only with 6MWT distance, AOR 0.99 (0.99-1.00). Prior hospitalization was associated with clinically important improvements in the mMRC dyspnea scale, AOR 3.50 (1.06-11.51); and PCFS, AOR 3.42 (1.16-10.06). Age, sex, and ICU admission were not associated with the results of any of the aforementioned tests/grading scales. In this non-randomized, case-control study, post-COVID-19 rehabilitation was associated with improvements in physical function, activity, HRQOL, respiratory symptoms, fatigue, and cognitive impairment. These associations were observed independently of timing of rehabilitation, age, sex, prior hospitalization, and ICU admission.

Chinese carrier of the HNF1A p.Gln444fs variant exhibits enhanced response to sulfonylureas

BackgroundWe assessed the response to sulfonylureas and the functional characteristics of HNF1A mutations in patients with maturity-onset diabetes of the young type 3 (MODY3). MethodsWe recruited a family with suspected MODY in this study, and gene sequencing (whole-exome sequencing) was used to screen germline mutations. Luciferase reporter assays were used to evaluate the activity of the mutated genes. ResultsHeterozygous HNF1A variant (NM_000545.8:c.1330_1331del, p.Gln444fs) was identified in the proband and was not found in his father, grandmother, and nonrelated healthy controls. The mutant protein had 552 amino acids, 110 fewer than the wild type protein. Furthermore, the amino acid sequence was completely different between the mutant protein and the wild type protein starting from the 444th amino acid. Luciferase reporter assays revealed that the variant had impaired HNF4A promoter–regulation activity. The patient did not achieve good hypoglycemic effects during long-term treatment with insulin and metformin. The effect of hypoglycemic treatment was highly significant after the addition of sulfonylurea drugs. ConclusionsThe HNF1A p.Gln444fs variant associated with MODY3, and most likely a truncated protein, impaired HNF1A transcriptional activity. The variant carrier experienced an enhanced response to sulfonylureas.

Exploring the safety of lycorine in the central nervous system and its impact on pain-like behaviors in mice

Alkaloid analgesics have been associated with adverse effects on the central nervous system (CNS). Therefore, it is crucial to characterize the effects of alkaloid analgesics. Plants rich in lycorine, an alkaloid, have shown promise as analgesics. However, the exploration of their CNS side effects, and analgesic effectiveness remains incomplete. The aim of the present study was to investigate the CNS safety profiles of lycorine and its potential analgesic efficacy. Lycorine (3, 10, and 30 mg/kg, intraperitoneal) did not affect motor coordination, and doses of 3 and 10 mg/kg of lycorine did not lead to any impairment in spontaneous locomotor activity. However, the highest dose (30 mg/kg) demonstrated a significant impairment in rearing behavior and an increase in immobility. The safety doses were subsequently used to assess the analgesic efficacy of lycorine in a mouse model of inflammatory pain. Lycorine (1, 3, and 10 mg/kg, intraperitoneal) demonstrated a dose-dependent reduction in pain-like behaviors in formalin-induced mice. In the in vitro study, lycorine regulated immune cells, suggesting its involvement as a cellular mechanism underlying the suppression of pain-like behaviors observed in the formalin model. Overall, our findings delineate the CNS safety range of lycorine in mice and suggest its potential use as an analgesic.

C-JUN overexpressing CAR-T cells in acute myeloid leukemia: preclinical characterization and phase I trial

Chimeric antigen receptor (CAR) T cells show suboptimal efficacy in acute myeloid leukemia (AML). We find that CAR T cells exposed to myeloid leukemia show impaired activation and cytolytic function, accompanied by impaired antigen receptor downstream calcium, ZAP70, ERK, and C-JUN signaling, compared to those exposed to B-cell leukemia. These defects are caused in part by the high expression of CD155 by AML. Overexpressing C-JUN, but not other antigen receptor downstream components, maximally restores anti-tumor function. C-JUN overexpression increases costimulatory molecules and cytokines through reinvigoration of ERK or transcriptional activation, independent of anti-exhaustion. We conduct an open-label, non-randomized, single-arm, phase I trial of C-JUN-overexpressing CAR-T in AML (NCT04835519) with safety and efficacy as primary and secondary endpoints, respectively. Of the four patients treated, one has grade 4 (dose-limiting toxicity) and three have grade 1–2 cytokine release syndrome. Two patients have no detectable bone marrow blasts and one patient has blast reduction after treatment. Thus, overexpressing C-JUN endows CAR-T efficacy in AML.

Genetic polymorphisms and post-stroke upper limb motor improvement - A systematic review and meta-analysis.

Post-stroke upper limb (UL) motor improvement is associated with adaptive neuroplasticity and motor learning. Both intervention-related (including provision of intensive, variable, and task-specific practice) and individual-specific factors (including the presence of genetic polymorphisms) influence improvement. In individuals with stroke, most commonly, polymorphisms are found in Brain Derived Neurotrophic Factor (BDNF), Apolipoprotein (APOE) and Catechol-O-Methyltransferase (COMT). These involve a replacement of cystine by arginine (APOEε4) or valines by 1 or 2 methionines (BDNF:val66met, met66met; COMT:val158met; met158met). However, the implications of these polymorphisms on post-stroke UL motor improvement specifically have not yet been elucidated. Examine the influence of genetic polymorphism on post-stroke UL motor improvement. Systematic Review and Meta-Analysis. We conducted a systematic search of the literature published in English language. The modified Downs and Black checklist helped assess study quality. We compared change in UL motor impairment and activity scores between individuals with and without the polymorphisms. Meta-analyses helped assess change in motor impairment (Fugl Meyer Assessment) scores based upon a minimum of 2 studies/time point. Effect sizes (ES) were quantified based upon the Rehabilitation Treatment Specification System as follows: small (0.08-0.18), medium (0.19 -0.40) and large (≥0.41). We retrieved 10 (4 good and 6 fair quality) studies. Compared to those with BDNF val66met and met66met polymorphism, meta-analyses revealed lower motor impairment (large ES) in those without the polymorphism at intervention completion (0.5, 95% CI: 0.11-0.88) and at retention (0.58, 95% CI:0.06-1.11). The presence of CoMT val158met or met158met polymorphism had similar results, with lower impairment (large ES ≥1.5) and higher activity scores (large ES ranging from 0.5-0.76) in those without the polymorphism. Presence of APOEε4 form did not influence UL motor improvement. Polymorphisms with the presence of 1 or 2 met alleles in BDNF and COMT negatively influence UL motor improvement. https://osf.io/wk9cf/.

Loss of Calpain 3 dysregulates store-operated calcium entry and its exercise response in mice.

Limb-Girdle Muscular Dystrophy R1/2A (LGMD R1/2A) is caused by mutations in the CAPN3 gene encoding Calpain 3, a skeletal-muscle specific, Ca2+-dependent protease. Localization of Calpain 3 within the triad suggests it contributes to Ca2+ homeostasis. Through live-cell Ca2+ measurements, muscle mechanics, immunofluorescence, and electron microscopy (EM) in Capn3 deficient (C3KO) and wild-type (WT) mice, we determined whether loss of Calpain 3 altered Store-Operated Calcium Entry (SOCE) activity. Direct Ca2+ influx measurements revealed loss of Capn3 elicits elevated resting SOCE and increased resting cytosolic Ca2+, supported by high incidence of calcium entry units (CEUs) observed by EM. C3KO and WT mice were subjected to a single bout of treadmill running to elicit SOCE. Within 1HR post-treadmill running, C3KO mice exhibited diminished force production in extensor digitorum longus muscles and a greater decay of Ca2+ transients in flexor digitorum brevis muscle fibers during repetitive stimulation. Striking evidence for impaired exercise-induced SOCE activation in C3KO mice included poor colocalization of key SOCE proteins, stromal-interacting molecule 1 (STIM1) and ORAI1, combined with disappearance of CEUs in C3KO muscles. These results demonstrate that Calpain 3 is a key regulator of SOCE in skeletal muscle and identify SOCE dysregulation as a contributing factor to LGMD R1/2A pathology.

Linked patterns of symptoms and cognitive covariation with functional brain controllability in major depressive disorder

Controllability analysis is an approach developed for evaluating the ability of a brain region to modulate function in other regions, which has been found to be altered in major depressive disorder (MDD). Both depressive symptoms and cognitive impairments are prominent features of MDD, but the case-control differences of controllability between MDD and controls can not fully interpret the contribution of both clinical symptoms and cognition to brain controllability and linked patterns among them in MDD. Sparse canonical correlation analysis was used to investigate the associations between resting-state functional brain controllability at the network level and clinical symptoms and cognition in 99 first-episode medication-naïve patients with MDD. Average controllability was significantly correlated with clinical features. The average controllability of the dorsal attention network (DAN) and visual network had the highest correlations with clinical variables. Among clinical variables, depressed mood, suicidal ideation and behaviour, impaired work and activities, and gastrointestinal symptoms were significantly negatively associated with average controllability, and reduced cognitive flexibility was associated with reduced average controllability. These findings highlight the importance of brain regions in modulating activity across brain networks in MDD, given their associations with symptoms and cognitive impairments observed in our study. Disrupted control of brain reconfiguration of DAN and visual network during their state transitions may represent a core brain mechanism for the behavioural impairments observed in MDD. National Natural Science Foundation of China (82001795 and 82027808), National Key R&D Program (2022YFC2009900), and Sichuan Science and Technology Program (2024NSFSC0653).

The neurotransmitter calcitonin gene-related peptide shapes an immunosuppressive microenvironment in medullary thyroid cancer

Neurotransmitters are key modulators in neuro-immune circuits and have been linked to tumor progression. Medullary thyroid cancer (MTC), an aggressive neuroendocrine tumor, expresses neurotransmitter calcitonin gene-related peptide (CGRP), is insensitive to chemo- and radiotherapies, and the effectiveness of immunotherapies remains unknown. Thus, a comprehensive analysis of the tumor microenvironment would facilitate effective therapies and provide evidence on CGRP’s function outside the nervous system. Here, we compare the single-cell landscape of MTC and papillary thyroid cancer (PTC) and find that expression of CGRP in MTC is associated with dendritic cell (DC) abnormal development characterized by activation of cAMP related pathways and high levels of Kruppel Like Factor 2 (KLF2), correlated with an impaired activity of tumor infiltrating T cells. A CGRP receptor antagonist could offset CGRP detrimental impact on DC development in vitro. Our study provides insights of the MTC immunosuppressive microenvironment, and proposes CGRP receptor as a potential therapeutic target.

Longitudinal relationships between depressive symptoms, functional impairment, and physical activity in later late life.

The purpose of this study was to investigate relationships between depressive symptoms, functional disability, and physical activity over time in community-dwelling older adults. The Religious Order Study and Rush Memory and Aging Project are longitudinal cohort studies based in the United States which began recruitment in 1994 and 1997, respectively. This analysis included 1611 participants (27.4% male, 92.9% White, 74.7% cognitively normal) who were included at age 80 and followed until age 90. Depressive symptoms were assessed using the modified Center for Epidemiologic Studies Depression scale. Functional disability was assessed using the Instrumental Activities of Daily Living (IADL) scale. Physical activity was self-reported hours of weekly exercise. Reciprocal temporal relationships between these variables were investigated using a random intercept cross-lagged panel model, which decomposes observed variables into stable between-person ('trait') and variable within-person ('state') components to estimate the directional effects between variables over time. Traits for depressive symptoms, IADL disability, and physical activity were correlated. IADL disability showed autoregressive effects; disability starting at age 82 strongly predicted subsequent disability. Consistent autoregressive effects were not observed for depressive symptoms nor physical activity. Several small cross-lagged effects between states were observed for IADL disability and physical activity, as well as for IADL disability and depressive symptoms. There were no direct effects between depressive symptoms and physical activity, but several paths through IADL disability were observed between ages 82 and 88. Functional disability played an important role in octogenarians, highlighting the importance of maintaining functional independence later in life.

Cladribine effects on patient-reported outcomes and their clinical and biometric correlates in highly active relapsing multiple sclerosis at first switch: the observational, multicenter, prospective, phase IV CLADFIT-MS study.

Patient-reported outcomes (PROs) are essential for understanding the effects of MS and its treatments on patients' lives; they play an important role in multiple sclerosis (MS) research and practice. We present the protocol for an observational study to prospectively assess the effect of cladribine tablets on PROs and their correlation to disability and physical activity in adults with highly active relapsing MS switching from a first disease modifying drug (DMD) to cladribine tablets in routine clinical practice at study sites in Italy. The primary objective will be to evaluate changes from baseline in the impact of highly active MS on self-assessed physical functioning 52 weeks after the switch to cladribine tablets using the Multiple Sclerosis Impact Scale-29 (MSIS-29). Secondary objectives will include self-assessed psychological impact of highly active MS in daily life and general health after the switch to cladribine tablets as well as changes in cognitive function, anxiety, and depression symptoms. Additional PRO measures will include the Hospital Anxiety and Depression Scale (HADS), the EuroQoL 5-Dimension 5-Level (EQ-5D-5L), the Work Productivity and Activity Impairment Questionnaire: Multiple Sclerosis (WPAI:MS), and the Patient-Reported Outcomes Measurement Information System (PROMIS). Wearable devices will acquire activity data (step counts, walking speed, time asleep, and energy expenditure). Additional clinical, radiological, and laboratory data will be collected when available during routine management. The findings will complement data from controlled trials by providing insight from daily clinical practice into the effect of cladribine tablets on the patient's experience and self-assessed impact of treatment on daily life.

MRAP2a Binds and Modulates Activity and Localisation of Prokineticin Receptor 1 in Zebrafish.

The prokineticin system plays a role in hypothalamic neurons in the control of energy homeostasis. Prokineticin receptors (PKR1 and PKR2), like other G-protein-coupled receptors (GPCRs) are involved in the regulation of energy intake and expenditure and are modulated by the accessory membrane protein 2 of the melanocortin receptor (MRAP2). The aim of this work is to characterise the interaction and regulation of the non-melanocortin receptor PKR1 by MRAP2a in zebrafish (zMRAP2a) in order to use zebrafish as a model for the development of drugs targeting accessory proteins that can alter the localisation and activity of GPCRs. To this end, we first showed that zebrafish PKR1 (zPKR1) is able to interact with both zMRAP2a and human MRAP2 (hMRAP2). This interaction occurs between the N-terminal region of zPKR1 and the C-terminal domain of zMRAP2a, which shows high sequence identity with hMRAP2 and a similar propensity for dimer formation. Moreover, we demonstrated that in Chinese hamster ovary (CHO) cells, zMRAP2a or hMRAP2 are able to modulate zPKR1 activation induced by zebrafish PK2 (zPK2) resulting in an impaired ERK and STAT3 activation.

Understanding and addressing microplastic pollution: Impacts, mitigation, and future perspectives

Improper disposal of household and industrial waste into water bodies has transformed them into de facto dumping grounds. Plastic debris, weathered on beaches degrades into micro-particles and releases chemical additives that enter the water. Microplastic contamination is documented globally in both marine and freshwater environments, posing a significant threat to aquatic ecosystems. The small size of these particles makes them susceptible to ingestion by low trophic fauna, a trend expected to escalate. Ingestion leads to adverse effects like intestinal blockages, alterations in lipid metabolism, histopathological changes in the intestine, contributing to the extinction of vulnerable species and disrupting ecosystem balance. Notably, microplastics (MPs) can act as carriers for pathogens, potentially causing impaired reproductive activity, decreased immunity, and cancer in various organisms. Studies have identified seven principal sources of MPs, including synthetic textiles (35%) and tire abrasion (28%), highlighting the significant human contribution to this pollution. This review covers various aspects of microplastic pollution, including sources, extraction methods, and its profound impact on ecosystems. Additionally, it explores preventive measures, aiming to guide researchers in selecting techniques and inspiring further investigation into the far-reaching impacts of microplastic pollution, fostering effective solutions for this environmental challenge.

Insomnia Symptoms Are Associated with Measures of Functional Deterioration and Dementia Status in Adults with Down Syndrome at High Risk for Alzheimer's Disease.

While obstructive sleep apnea (OSA) and insomnia symptoms in neurotypical populations are associated with Alzheimer's disease (AD), their association with dementia in adults with Down syndrome (DS) remains less clear, even though these symptoms are prevalent and treatable in DS. Understanding their associations with AD-related dementia status, cognitive impairment, and functional deterioration may lead to interventions to slow decline or disease progression in adults with DS. To characterize differences in OSA and insomnia symptom expression by dementia status, and to determine which sleep factors support dementia diagnosis. Multimodal consensus conference was used to determine dementia status in 52 adults with DS (52.2 ± 6.4 years, 21 women). Cognitive impairment, adaptive behavior skills, and symptoms of OSA and insomnia were quantified using validated assessments for adults with DS and their primary informants. A sex by dementia status interaction demonstrated that older women with DS and dementia had more severe terminal insomnia but not OSA symptoms relative to older women with DS who were cognitively stable (CS). Greater insomnia symptom severity was associated with greater functional impairments in social and self-care domains adjusting for age, sex, premorbid intellectual impairment, and dementia status. Insomnia symptoms are more severe in women with DS with dementia than in women with DS and no dementia, and regardless of dementia status or sex, more severe insomnia symptoms are associated with greater impairment in activities of daily living. These findings underscore the potential importance of early insomnia symptom evaluation and treatment in women with DS at risk of developing AD.

Recovering Work Productivity in a Population With Chronic Musculoskeletal Pain: Unveiling the Value and Cost-Savings of a Digital Care Program.

To investigate potential savings obtained from restoring productivity in employees with chronic MSK pain through a digital care program (DCP). Secondary analysis of a prospective longitudinal study assessing cumulative savings overall or across several industry sectors by analyzing changes in Work Productivity and Activities Impairment (WPAI questionnaire). Employees from 50 U.S. states started the program ( n = 5032). Significant improvements in productivity impairment were observed across all industries, yielding median cumulative savings from $151 (95% confidence interval [CI], 128-174) to $294 (95% CI, 286-303) per participant at treatment end. Twelve-month projections estimated median savings of $2916 (95% CI, 2861-2972). Additionally, significant improvements in non-work-related daily activities were observed. This study underlines the burden of MSK-related productivity loss on employers' financial balance, illustrating the importance of a DCP to assist patients to recover quality of life and succeed professionally.

Impaired myoblast differentiation and muscle IGF-1 receptor signaling pathway activation after N-glycosylation inhibition.

The role of N-glycosylation in the myogenic process remains poorly understood. Here, we evaluated the impact of N-glycosylation inhibition by Tunicamycin (TUN) or by phosphomannomutase 2 (PMM2) gene knockdown, which encodes an enzyme essential for catalyzing an early step of the N-glycosylation pathway, on C2C12 myoblast differentiation. The effect of chronic treatment with TUN on tibialis anterior (TA) and extensor digitorum longus (EDL) muscles of WT and MLC/mIgf-1 transgenic mice, which overexpress muscle Igf-1Ea mRNA isoform, was also investigated. TUN-treated and PMM2 knockdown C2C12 cells showed reduced ConA, PHA-L, and AAL lectin binding and increased ER-stress-related gene expression (Chop and Hspa5 mRNAs and s/uXbp1 ratio) compared to controls. Myogenic markers (MyoD, myogenin, and Mrf4 mRNAs and MF20 protein) and myotube formation were reduced in both TUN-treated and PMM2 knockdown C2C12 cells. Body and TA weight of WT and MLC/mIgf-1 mice were not modified by TUN treatment, while lectin binding slightly decreased in the TA muscle of WT (ConA and AAL) and MLC/mIgf-1 (ConA) mice. The ER-stress-related gene expression did not change in the TA muscle of WT and MLC/mIgf-1 mice after TUN treatment. TUN treatment decreased myogenin mRNA and increased atrogen-1 mRNA, particularly in the TA muscle of WT mice. Finally, the IGF-1 production and IGF1R signaling pathways activation were reduced due to N-glycosylation inhibition in TA and EDL muscles. Decreased IGF1R expression was found in TUN-treated C2C12 myoblasts which was associated with lower IGF-1-induced IGF1R, AKT, and ERK1/2 phosphorylation compared to CTR cells. Chronic TUN-challenge models can help to elucidate the molecular mechanisms through which diseases associated with aberrant N-glycosylation, such as Congenital Disorders of Glycosylation (CDG), affect muscle and other tissue functions.

X-Linked Myotubular Myopathy and Mitochondrial Function in Muscle and Liver Samples.

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.

An integrated multitool analysis contributes elements to interpreting unclassified factor IX missense variants associated with hemophilia B

BackgroundDissection of genotype–phenotype relationships in hemophilia B (HB) is particularly relevant for challenging (mild HB) or for HB-associated but unclassified factor (F)IX missense variants. ObjectiveTo contribute elements to interpret unclassified HB-associated FIX missense variants by a multiple-level approach upon identification of a reported, but uncharacterized, FIX missense variant associated with mild HB. MethodsMolecular modeling of wild-type and V92A FIX variants, expression studies in HEK293 cells with evaluation of protein (ELISA, western blotting) and activity (activated partial thromboplastin time-based/chromogenic assays) levels after recombinant expression, and multiple prediction tools. ResultsThe F9(NM_000133.4):c.275T>C (p.V92A) variant was found in a mild HB patient (antigen, 45.4 U/dL; coagulant activity, 23.6 IU/dL; specific activity, 0.52). Newly generated molecular models showed alterations in Gla/EGF1–EGF2 domain conformation impacting Ca++ affinity and protein–protein interactions with activated factor XI (FXIa). Multitool analysis indicated a moderate impact on protein structure/function of the valine-to-alanine substitution, in accordance with patient and modeling data. Expression studies on the V92A variant showed a specific activity (0.49 ± 0.07; wild-type, 1.0 ± 0.1) recapitulating that of the natural variant, and pointed toward a moderate activation impairment as the main determinant underlying the p.V92A defect. The validated multitool approach, integrated with evidence-based data, was challenged on a panel (n = 9) of unclassified FIX missense variants, which resulted in inferred protein (secretion/function) outputs and HB severity. ConclusionThe rational integration of multitool and multiparameter analyses contributed elements to interpret genotype/phenotype relationships of unclassified FIX missense variants, with implications for diagnosis, management, and treatment of HB patients, and potentially translatable into other human disorders.

Estimating Disability in Patients with Essential Tremor: Comparison of Tremor Rating Scale, Spiral Drawing, and Accelerometric Tremor Power.

Although performance rating scales, spiral drawing, water pouring, and accelerometry are commonly used to assess tremor severity, the extent to which their results correlate with impairment in activities of daily living (ADL) remains unclear. The aim was to identify the most effective predictors of ADL in essential tremor (ET). Forty ET patients were examined using The Essential Tremor Rating Assessment Scale (TETRAS), spiral drawing, volume of water spilled, and accelerometric tremor power. Root-mean-square error, R2, and F-test were calculated for models predicting TETRAS ADL subscore. TETRAS Performance Subscale explained the variability in TETRAS ADL with an R2 value of 0.686. Models incorporating spiral rating and accelerometric tremor power (R2 = 0.731) and water spillage volume (R2 = 0.756) were not statistically superior. TETRAS performance subscore predicted nearly 70% ADL impairment in ET patients. Incorporating the spiral rating, accelerometric tremor power, and water pouring test did not enhance ADL estimation.

Point mutations at specific sites of the nsp12–nsp8 interface dramatically affect the RNA polymerization activity of SARS-CoV-2

In a recent characterization of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variability present in 30 diagnostic samples from patients of the first COVID-19 pandemic wave, 41 amino acid substitutions were documented in the RNA-dependent RNA polymerase (RdRp) nsp12. Eight substitutions were selected in this work to determine whether they had an impact on the RdRp activity of the SARS-CoV-2 nsp12-nsp8-nsp7 replication complex. Three of these substitutions were found around the polymerase central cavity, in the template entry channel (D499G and M668V), and within the motif B (V560A), and they showed polymerization rates similar to the wild type RdRp. The remaining five mutations (P323L, L372F, L372P, V373A, and L527H) were placed near the nsp12-nsp8F contact surface; residues L372, V373, and L527 participated in a large hydrophobic cluster involving contacts between two helices in the nsp12 fingers and the long α-helix of nsp8F. The presence of any of these five amino acid substitutions resulted in important alterations in the RNA polymerization activity. Comparative primer elongation assays showed different behavior depending on the hydrophobicity of their side chains. The substitution of L by the bulkier F side chain at position 372 slightly promoted RdRp activity. However, this activity was dramatically reduced with the L372P, and L527H mutations, and to a lesser extent with V373A, all of which weaken the hydrophobic interactions within the cluster. Additional mutations, specifically designed to disrupt the nsp12-nsp8F interactions (nsp12-V330S, nsp12-V341S, and nsp8-R111A/D112A), also resulted in an impaired RdRp activity, further illustrating the importance of this contact interface in the regulation of RNA synthesis.

LRIG1 controls proliferation of adult neural stem cells by facilitating TGFβ and BMP signalling pathways

Adult Neural Stem Cells (aNSCs) in the ventricular-subventricular zone (V-SVZ) are largely quiescent. Here, we characterize the mechanism underlying the functional role of a cell-signalling inhibitory protein, LRIG1, in the control of aNSCs proliferation. Using Lrig1 knockout models, we show that Lrig1 ablation results in increased aNSCs proliferation with no change in neuronal progeny and that this hyperproliferation likely does not result solely from activation of the epidermal growth factor receptor (EGFR). Loss of LRIG1, however, also leads to impaired activation of transforming growth factor beta (TGFβ) and bone morphogenic protein (BMP) signalling. Biochemically, we show that LRIG1 binds TGFβ/BMP receptors and the TGFβ1 ligand. Finally, we show that the consequences of these interactions are to facilitate SMAD phosphorylation. Collectively, these data suggest that unlike in embryonic NSCs where EGFR may be the primary mechanism of action, in aNSCs, LRIG1 and TGFβ pathways function together to fulfill their inhibitory roles.