Biochemical Conditions Research Articles

Nicking Activity of M13 Bacteriophage Protein 2.

Gene II Protein (Gp2/P2) is a nicking enzyme of the M13 bacteriophage that plays a role in the DNA replication of the viral genome. P2 recognizes a specific sequence at the f1 replication origin and nicks one of the strands and starts replication. This study was conducted to address the limitations of previous experiments, improve methodologies, and precisely determine the biochemical activity conditions of the P2 enzyme in vitro. For these purposes, the gene encoding P2 was cloned in Escherichia coli and expressed as a hybrid protein together with a green fluorescent protein (P2-GFP). P2-GFP was purified via metal affinity chromatography, and its nicking activity was determined by conversion of supercoiled DNA to open circular or linear forms. We discovered that, among the two loops of the f1 origin defined previously, P2 can recognize just the A1 loop. When a supercoiled plasmid containing the f1 origin was treated with P2-GFP, the plasmid was present in an open circular form, indicating that a nick was created on only one of the strands. However, when the A1 loop sequence was inserted into the 3' ends of both strands by cloning a PCR product obtained by primers with the A1 loop sequence, the plasmid was linearized by treatment with P2-GFP, indicating that nicks were created on both strands. Certain infectious diseases are caused by single-stranded DNA viruses, and some of them have specific nicking enzymes that enable strand displacement and free 3' end of a single strand that works as a primer for their replication mechanisms like M13 bacteriophages, such as parvovirus B19. Despite there being different host viruses such as bacteria and humans, their DNA replication mechanisms are very similar in this concept. Investigating the features of the P2-nicking enzyme may deepen the understanding of human pathogenic single-stranded viruses and facilitate the development of drugs that inhibit viral replication.

Stability and Bioaccessibility of β-Arbutin in Simulated Digestion Conditions

In this study, the effects of physicochemical and biochemical digestion conditions on β-arbutin stability and bioaccessibility were investigated. β-Arbutin, at doses that correspond to its natural occurrence in plant materials (i.e., 1–100 mg), was subjected to gastric and intestinal electrolyte treatments (application of physicochemical factors) or the whole digestion process (application of physicochemical and biochemical factors). Its content in in vitro bioaccessible fractions was determined using high-performance liquid chromatography (HPLC), and percentage bioaccessibility was calculated. The study shows very high stability and bioaccessibility of β-arbutin in a wide range of applied concentrations. Especially at doses ≥7.5 mg, bioaccessibility was close to 100% regardless of the stage of digestion and the type of treatment (electrolyte treatment or the whole digestion process). The assessment of phytochemicals in terms of their stability and interactions with the digestion environment can help in the future evaluation of their applicability for therapeutic purposes. The high bioaccessibility of β-arbutin within its multifunctional biological activity makes it a promising substance for phytomedicinal applications.

Hyperactivity and Pro-inflammatory Functions of Platelets in Diabetes.

Cardiovascular complications claim the lives of up to 70% of patients with diabetes mellitus (DM). The mechanisms increasing cardiovascular risk in DM remain to be fully understood and successfully addressed. Nonetheless, there is increasing evidence in the scientific literature of the participation of platelets in the cardiovascular complications of DM. Multiple reports describe the hyperactivity of platelets in DM and their participation in inflammatory responses. The understanding of the mechanisms underlying the contribution of platelets to cardiovascular pathologies in DM will help the development of targeted therapeutic strategies able to reduce cardiovascular risk in these patients. In this literature review, we summarise our current understanding of the molecular mechanisms leading to the contribution of platelets to cardiovascular risk in DM. Both platelet haemostatic activity leading to thrombus formation and their participation to inflammatory processes are stimulated by the biochemical conditions associated with DM. We also present evidence on how DM affect the efficacy of existing therapeutic treatments for thrombosis and, by converse, how antidiabetic drugs may affect platelet function and the haemostasis/thrombosis balance. Taken together, the growing evidence of the different and unexpected roles of platelets in the progression of DM provides a strong rationale for the design of cardiovascular drugs targeting specifically platelets, their pro-inflammatory activity and their activation mechanisms in this disease. Overall, this article provides an important up-to-date overview of the pathophysiological alterations of platelets in DM, which need to be taken into account for the effective management of cardiovascular health in this disease.

CAR-T cells are more affected than T lymphocytes by mechanical constraints: A microfluidic-based approach.

CAR-T cell therapy has attracted considerable attention in recent years owing to its well-known efficacy against haematopoietic malignancies. Nevertheless, this immunotherapy fails against solid tumours due to hostile conditions found in the tumour microenvironment. In this context, many relevant biochemical factors have been thoroughly studied, but crucial mechanical cues have been underestimated. We developed an innovative approach using microfluidic devices, which recreate the biomechanical aspects of solid tumours. Using these platforms, we quantified immune cell migration (T and CAR-T cells) under different confinement conditions. We found that both CAR-T cell and T cell velocities are affected by the biomechanical and chemical cues studied, which are closely related to those found in solid tumours. Under biochemical stimulus-free conditions, the velocity of T cells is independent of the width of the microchannel, whereas the velocity of CAR-T cells is greatly reduced in the highest confinement channels. When chemoattractants or tumour cells are added, immune cells display increased confined migration velocity. However, in the presence of immunosuppressive chemokines, T cells become slower, whereas CAR-T cells significantly increase their velocity via a chimeric cytokine receptor. Our approach contributes to a better understanding of immune cell migration and the influence of mechanical constraints, which will allow the testing of new ways to improve CAR-T cell trafficking into solid tumours. Therefore, our study revealed that the migratory behaviour of CAR-T cells differs from that of T cells under confined conditions and that biomechanical cues, such as cell deformability caused by confinement, can influence the correct infiltration of immune cells into solid tumours during the immune response.

A FRET assay to quantitate levels of the human β-cardiac myosin interacting heads motif based on its near-atomic resolution structure.

In cardiac muscle, many myosin molecules are in a resting or "OFF" state with their catalytic heads in a folded structure known as the interacting heads motif (IHM). Many mutations in the human β-cardiac myosin gene that cause hypertrophic cardiomyopathy (HCM) are thought to destabilize (decrease the population of) the IHM state. The effects of pathogenic mutations on the IHM structural state are often studied using indirect assays, including a single-ATP turnover assay that detects the super-relaxed (SRX) biochemical state of myosin functionally. Here we develop and use a fluorescence resonance energy transfer (FRET) based sensor for direct quantification of the IHM state in solution. The FRET sensor was able to quantify destabilization of the IHM state in solution, induced by (a) increasing salt concentration, (b) altering proximal S2 tail length, or (c) introducing the HCM mutation P710R, as well as stabilization of the IHM state by introducing a dilated cardiomyopathy-causing mutation (E525K). Our FRET sensor conclusively showed that these perturbations indeed alter the structural IHM state. These results establish that the structural IHM state is one of the structural correlates of the biochemical SRX state in solution.

Antiviral Drug Discovery with an Optimized Biochemical Dengue Protease Assay: Improved Predictive Power for Antiviral Efficacy

The viral NS2B-NS3 protease is a promising drug target to combat dengue virus (DENV) and other emerging flaviviruses. The discovery of novel DENV protease inhibitors with antiviral efficacy is hampered by the low predictive power of biochemical assays. We herein present a comparative evaluation of biochemical DENV protease assay conditions and their benchmarking against antiviral efficacy and a protease-specific reporter gene assay. Variations were performed with respect to pH, type of detergent, buffer, and substrate. The revised assay conditions were applied in a medicinal chemistry effort aimed at phenylglycine protease inhibitors. This validation study demonstrated a considerably improved predictive power for antiviral efficacy in comparison to previous approaches. An extensive evaluation of phenylglycine-based DENV protease inhibitors with highly diverse N-terminal caps indicates further development potential in this structural region. Furthermore, the phenylglycine moiety may be less essential than previously assumed, providing a development option towards reduced lipophilicity and thereby an improved pharmacokinetic and toxicity profile.

Deciphering cell to cell spatial relationship for pathology images using SpatialQPFs

Understanding spatial dynamics within tissue microenvironments is crucial for deciphering cellular interactions and molecular signaling in living systems. These spatial characteristics govern cell distribution, extracellular matrix components, and signaling molecules, influencing local biochemical and biophysical conditions. Despite significant progress in analyzing digital pathology images, current methods for capturing spatial relationships are limited. They often rely on specific spatial features that only partially describe the complex spatial distributions of cells and are frequently tied to particular outcomes within predefined model frameworks. Furthermore, these methods are typically limited to field of view analysis, which restricts their capacity to capture spatial patterns across whole-slide images, thereby limiting their ability to fully address the complexities of tissue architecture. To address these limitations, we present SpatialQPFs (Spatial Quantitative Pathology Features), an R package designed to extract interpretable spatial features from cell imaging data using spatial statistical methodologies. Leveraging segmented cell information, our package offers a comprehensive toolkit for applying a range of spatial statistical methods within a stochastic process framework, including analyses of point process data, areal data, and geostatistical data. By decoupling feature extraction from specific outcome models, SpatialQPFs enables thorough large-scale spatial analyses applicable across diverse clinical and biological contexts. This approach enhances the depth and accuracy of spatial insights derived from tissue data, empowering researchers to conduct comprehensive spatial analyses efficiently and reproducibly. By providing a flexible and robust framework for spatial feature extraction, SpatialQPFs facilitates advanced spatial analyses, paving the way for new discoveries in tissue biology and pathology. SpatialQPFs code and documentation are publicly available at https://github.com/Genentech/SpatialQPFs.

Role of Nicotinamide in the Pathogenesis of Actinic Keratosis: Implications for NAD+/SIRT1 Pathway.

Actinic keratosis (AK) is a precursor to invasive squamous cell carcinoma, making early diagnosis and treatment essential to prevent progression. Among available therapeutic options, nicotinamide (NAM) has shown potential in reducing AK progression. NAM is a precursor of nicotinamide adenine dinucleotide (NAD+), which activates sirtuin (SIRT)1, a protein with anti-cancer properties. Although the role of SIRT1 in AK is still debated, no data currently exist on the systemic modulation of this protein in AK. Therefore, this study aims to evaluate whether NAM, by increasing serum NAD+ levels, may promote SIRT1 activation in peripheral blood mononuclear cells (PBMCs) in AK patients. Thirty patients were enrolled and treated with NAM for 24 months. Hematological, biochemical, and skin condition assessments were conducted, alongside the measurement of SIRT1 and NAD+ levels. A decrease in basophils, monocytes, total cholesterol, and blood glucose levels was observed in the study group, along with a reduction in AK lesions. Notably, NAM treatment significantly enhanced serum NAD+ levels, and nuclear SIRT1 activity in PBMCs. In conclusion, NAM administration significantly reduced AK progression in a NAD+/SIRT1-dependent manner, supporting its role as a chemopreventive agent in AK management.

An Arteriovenous Bioreactor Perfusion System for Physiological In Vitro Culture of Complex Vascularized Tissue Constructs.

The generation and perfusion of complex vascularized tissues in vitro requires sophisticated perfusion techniques. For multiscale arteriovenous networks, not only the arterial, but also the venous, biomechanical and biochemical conditions that physiologically exist in the human body must be accurately emulated. For this, we here present a modular arteriovenous perfusion system for the in vitro culture of a multi-scale bioartificial vascular network. The custom-built perfusion system consisted of two circuits: in the arterial circuit, physiological arterial biomechanical and biochemical conditions were simulated using a modular set-up with a pulsatile peristaltic pump, compliance chambers, and resistors. In the venous circuit, venous conditions were emulated accordingly. In the center of the system, a bioartificial multi-scale vascularized fibrin-based tissue was perfused by both circuits simultaneously under biomimetic arteriovenous conditions. Culture conditions were monitored continuously using a multi-sensor monitoring system. The physiological arterial and venous pressure- and flow-curves, as well as the microvascular arteriovenous oxygen partial pressure gradient, were accurately emulated in the perfusion system. The multi-sensor monitoring system facilitated live monitoring of the respective parameters and data-logging. In a proof-of-concept experiment, vascularized three-dimensional fibrin tissues showed sustained cell viability and homogenous microvessel formation after culture in the perfusion system. The arteriovenous perfusion system facilitated the in vitro culture of a multiscale vascularized tissue under physiological pressure-, flow-, and oxygen-gradient conditions. With that, it presents a promising technique for the in vitro generation and culture of complex large-scale vascularized tissues.

Living Along Distribution Margins: Differences in the Body and Biochemistry of Red Squat Lobster Morphotypes (Grimothea monodon) from the Humboldt Current System

Grimothea monodon, an important fishery resource in the Humboldt Current marine ecosystem (HCE), present two contrasting morphotypes (PM, pelagic morphotype; BM, benthic morphotype). The fishery management of G. monodon is focused on understanding only fishery aspects that apply to a limited area, and there are currently no studies that evaluate the nutritional status of these morphotypes. This study evaluated the biological performance of PM and BM, analyzing the body (size, CL; weight, W; condition factor, Kn) and biochemical condition (glucose, G; proteins, P; lipids, L; fatty acids, FAs). The results reveal that G. monodon showed differences in CL and W between morphotypes, with higher values in BM than PM. The Kn was different between morphotypes with a tendency of isometric growth. In turn, the G contents were higher in PM than BM, while the contents of P, L, and FAs showed an opposite tendency, with higher contents recorded in BM than PM. Our findings suggest that the Kn should be included to strengthen the biological parameters and their relationships used in fishery management models. Differences in the biochemical condition between morphotypes can be considered potentially adaptive, in response to the combined effect of environmental factors that vary in the HCE.

Mitigating effects of Nigeria seaweed phytonutrients on biochemical and physiological conditions of Lycopersicon esculentum under heavy metal-induced abiotic stress

Abiotic stress has become a significant issue in recent years, affecting various physiological and biochemical aspects of crops and threatening food security. This study aimed to investigate the effects of seaweed on the biochemical and physiological conditions of Lycopersicon esculentum under heavy metal-induced abiotic stress. Lycopersicon esculentum plants were grown in greenhouse bags for four weeks and then exposed to 0.10M Pb Nitrate. They were divided into six groups: one control group sprayed with tap water and five experimental groups sprayed with different seaweed concentrations (0%, 20%, 40%, 60%, and 80%). Results showed that abiotic stress led to notable decreases in root length, shoot length, chlorophyll a, chlorophyll b, stomatal conductance, photosynthetic rate, Rubisco activity, and carotenoids by 48%, 47% 38%, 65%, 61%, 77%, 75%, and 68%, respectively. Seaweed treatment improved these indices, with the 80% seaweed group showing increases of 27%, 21%, 44%, 36%, 56%, and 48%, 54% after 21 days. Additionally, seaweed application enhanced antioxidant activities in the roots (SOD by 71%, CAT by 45%, POD by 51%, and APX by 92%) and in the leaves (SOD by 18%, CAT by 26%, POD by 34%, APX by 58%) compared to the control. The study concluded that seaweeds significantly mitigated oxidative stress in plants, boosting growth, antioxidant potential, mineral absorption, and osmotic protection. Nigeria seaweeds could be a promising tool to enhance food production by reducing oxidative stress in crops.

Synergistic organic manure treatment with Al/Fe/Ca-based fluoride-fixing agents promote soil formation and utilization of phosphate flotation tailings

Soil utilization of phosphate ore flotation tailings (PTs) was achieved using F-fixing agents combined with organic manure treatment to address issues related to inefficient stabilization of P-F, heavy metal solidification/stabilization, poor physicochemical properties, and ecological disruption. The formulation for PTs soil utilization included 1.75 % polyaluminum sulfate (PAS), 1.75 % FeSO4, and 0.25 % CaO, with PTs content at ≥86.75 %. This approach enhanced water retention and improved nutrient and biochemical conditions. Various nutrient indexes met general planting soil requirements: organic matter 24.93 g/kg, available K 252.26 mg/kg, available Ca 2048.67 mg/kg, available Mg 246.13 mg/kg, and ammonia-nitrogen 42.47 mg/kg. The water-soluble P content of PTs-based soil decreased to 6.96 mg/kg, while available P increased to 677.99 mg/kg. Mn leaching toxicity was less than 0.016 mg/L, with a stabilization efficiency of 96.86 %. Water-soluble F in PTs-based soil was reduced to 11.133 mg/kg. This study maximized phosphorus resource utilization and prevented the migration of water-soluble P, F, and Mn to the surrounding environment. Potting experiments showed PTs-based soil was more effective than red soil and PTs-based raw materials in cabbage plantation, achieving a maximum seedling emergence rate of 98.33 %. Microbial diversity increased, and community structure improved in 40-day soil formation experiments, with PTs-based soils developing microbial communities involved in carbon and nitrogen cycling, enhancing resistance to external environmental disturbances, and promoting ecological utilization. These findings offer practical insights into the ecological utilization of large quantities of PTs and present a cost-effective approach for producing planting soils or ecological mulches from similar solid wastes.

Saliva metabolomics: concepts and applications in oral disorders.

The purpose of this review was to present the basic concepts of metabolomics methodology and the use of saliva for diagnostic, prognostic, and predictive strategies. This review followed the focus in: "saliva metabolomics" and "oral diseases". The authors searched studies on PubMed database. The inclusion criteria were original studies and reviews that assessed metabolomics techniques. A descriptive analysis was performed considering the study design, approach system, clinical steps, and tools for the determination of profile or biomarkers metabolites, and the advantages and disadvantages. Metabolomic analyses use a combination of analytical instrumentation and informatic tools to provide information on metabolite characteristics. In this review we described different technologies applied and the advantages and limitations of each technique. Furthermore, in the literature search, we retrieved 25 studies that investigated saliva metabolites in oral diseases: 8 studies used targeted analysis and 17 untargeted metabolomics approaches. Most studies included patients with periodontal diseases, oral squamous cell carcinoma, and Sjögren Syndrome. The most frequently reported metabolites were glycine, leucine, phenylalanine, dipeptides, linoleic acid, arachidonic acid, tyrosine, choline, taurine, lactate, valine, and proline. Metabolomics analysis has emerged as a powerful tool for tumor diagnosis and to enhance tumor classification, including salivary gland tumors (SGTs). It also holds promise for developing personalized treatment plans and defining more precise prognostic categories. Metabolomics is the most functional and comprehensive technique for monitoring and understanding gene functions and identifying the biochemical state of an organism in response to genetic and environmental changes.

Study on the Influence of Sludge Biochemical Characteristics and Treatment Conditions on Rheological Properties

Abstract In response to the differences in the organic matter, oil and other components of temporary sludge stored in different storage areas of Shanghai Lao-gang, which affect the long-distance transportation of sludge, a full range sampling was conducted on the temporary sludge. Based on the results of solid content measurement, the pH value, mineral oil, total nitrogen, organic matter content, total oil and other six selected sludge samples were subjected to biochemical testing, and one sludge sample was selected for drying and concentration treatment. At the same time, sludge rheological tests were conducted on the biochemical testing sludge samples and the concentrated sludge samples, and the impact of sludge biochemical characteristics and sludge concentration on sludge rheological characteristics was compared and analyzed, which provide reference for the construction process of temporary sludge transportation.

Biomarkers and Novel Therapies of Diabetic Neuropathy: An Updated Review.

Diabetic neuropathy is a persistent consequence of the biochemical condition known as diabetes mellitus. As of now, the identification and management of diabetic neuropathy continue to be problematic due to problems related to the safety and efficacy of existing therapies. This study examines biomarkers, molecular and cellular events associated with the advancement of diabetic neuropathy, as well as the existing pharmacological and non-pharmacological treatments employed. Furthermore, a holistic and mechanism-centric drug repurposing approach, antioxidant therapy, Gene and Cell therapies, Capsaicin and other spinal cord stimulators and lifestyle interventions are pursued for the identification, treatment and management of diabetic neuropathy. An extensive literature survey was done on databases like PubMed, Elsevier, Science Direct and Springer using the keywords "Diabetic Neuropathy", "Biomarkers", "Cellular and Molecular Mechanisms", and "Novel Therapeutic Targets".Thus, we may conclude that non-pharmacological therapies along with palliative treatment, may prove to be crucial in halting the onset of neuropathic symptoms and in lessening those symptoms once they have occurred.

Climate-driven decline in water level causes earlier onset of hypoxia in a subtropical reservoir

Hypoxia, especially in the bottom water, is occurring in deep and stratified reservoirs worldwide, threatening aquatic biodiversity, ecosystem functions and services. However, little is known about the timing of onset and ending of hypoxia, especially in subtropical reservoirs. Based on five-year (from April 2015 to January 2020) sampling of a subtropical monomictic deep reservoir (Tingxi Reservoir) in southeast China, we found the evidence of about 40 days earlier onset of hypolimnion hypoxia during low water level periods in dry years compared to wetter high water level years. We explored the effects of stratification and mixing conditions on hypoxia, cyanobacterial biomass, and nutrient dynamics; and revealed the physical and biochemical conditions that drove hypoxia. The results indicated that 1) The decline in water level increased the intensity of thermal stratification, resulting in 40 days earlier onset of hypolimnion hypoxia in dry years than in wet years; 2) The decline in water level expanded the extent of hypoxia by promoting nutrient accumulation and phytoplankton biomass growth; 3) Warmer climate and less precipitation (drought) significantly promoted the risk of hypoxic expansion and endogenous phosphorus release in subtropical reservoirs. We suggest that more attention needs to be paid to the early onset of hypoxia and its consequences on water quality in subtropical stratified reservoirs during low water level periods in a changing climate.

Engineered microenvironments and pancreatic islet-on-chips for screening sugar substitute and antidiabetic compounds

Recent advancements in the food industry have rekindled interest in the safety of food additives, such as sugar substitutes and food pigments. Consequently, the main purpose of this study was to develop models that can more accurately predict the effects of these additives on the human body. In response to this demand, we have created an innovative pancreas islet-on-a-chip system featuring a concentration gradient generator and a perfusable 3D cell culture array. This setup facilitates the 3D culture of pseudo-islets under stable biochemical and biophysical conditions. When compared to static culture environments, our dynamic environment maintains islet cell viability at over 95 %, resulting in larger cell clusters that exhibit a higher tendency for aggregation up to 30 μm. Furthermore, the expression levels of key factors integral to islet development, namely INS-1, INS-2, and PDX-1, increased by 4.5-fold, 1.9-fold, and 5.8-fold respectively in the dynamic environment. Utilizing this sophisticated pancreas islet-on-a-chip model, we discovered that the consumption of sugar substitutes like erythritol and sucralose for 1 h does not impact insulin secretion levels. In contrast, the administration of glucagon-like peptide 1 (GLP-1), GLP-1 receptor (GLP-1R) agonist exendin-4, curcumin, and a combination therapy group led to a substantial increase in insulin secretion levels (p < 0.01). Such engineered microenvironments and pancreatic islet-on-chips offer a groundbreaking platform for evaluating sugar substitutes and antidiabetic compounds.

Isolation and Characterization of Bacteriocin Producing Levilactobacillus brevis Strain ABRIINW-K from Buffalo Dung

Bacteriocins are proteins secreted by many species of bacteria to inhibit other bacteria, thus eliminating competitors to gain resources. Bacteria from the Lactobacillus group are known for their applications as probiotics and food preservatives. They have earned a reputation for producing substances that inhibit the growth of other microorganisms, which include organic acids, diacetyl, and bacteriocins. Produced by the ribosomes, bacteriocins are cationic proteins that inhibit other bacteria coexisting within a shared ecological habitat. Due to their potential uses in a variety of applications large-scale production of Bacteriocins would be necessary. The study aimed to identify and characterize Lactobacillus bacteria that produce potent bacteriocins and to analyze the antimicrobial activity and stability of the isolated bacteriocin under various physical and biochemical conditions. A total of 50 samples including buffalo dung, cheese, and rhizospheric region of plants were screened to isolate 8 Lactobacillus Li-1, Li-2, Li-3, Li-4, Li-5, Li-6, Li-7, and Li-8, confirmed by gram staining and other biochemical tests. The cell free supernatant from the Li-3 strain showed higher inhibition of Escherichia coli and Staphylococcus aureus, as compared to the other isolated strains. Li-3 strain was further identified as Levilactobacillus brevis strain ABRIINW-K by 16S rRNA gene sequencing. The bacteriocin isolated from this strain is a thermostable peptide (~6kDa), which is characteristic of class II bacteriocins, with potent antibacterial activity against Lactobacillus rhamnosus, Escherichia coli, and Salmonella enterica.

Myosin ATPase inhibition fails to rescue the metabolically dysregulated proteome of nebulin-deficient muscle.

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 4week 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 4weeks, 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.

Changes in VOCs from a chestnut blight fungus Cryphonectria parasitica by a hypovirus infection: mycoviral infection alters fungal smell for insect vectors

BackgroundThe chestnut blight fungus, Cryphonectria parasitica, and its Cryphonectria hypovirus 1 (CHV1) comprise a useful model system to study fungus–virus interactions. CHV1 infection results in various phenotypic changes in the fungal host, including hypovirulence and other associated symptoms. Many studies have investigated the effects of hypoviral infection and how this infection affects physiological and biochemical states: however, no studies have examined volatile organic compounds (VOCs).ResultsThis study characterized the global profile of VOCs released from C. parasitica, and by comparing CHV1-free with CHV1-infected isogenic strains, proved that CHV1 infection significantly affects the composition and levels of VOCs. We demonstrated that these VOC alterations were caused by viral regulation of the expression of fungal genes encoding enzymes responsible for the production of VOCs. The changed VOC profile resulting from CHV1 infection was more attractive to insects than the VOC profile from the virus-free strain, suggesting differences in the efficacy of fungal dissemination by the insect vector.ConclusionsWe characterized VOCs from C. parasitica and demonstrated that mycovirus (CHV1) infection affects fungal VOCs. We provided evidences that these alterations are caused by the modulation of the corresponding gene expression by CHV1 and resulted in changes in attractiveness to insects, suggesting the improved efficacy of hypovirulent C. parasitica for insect-borne dissemination.Graphical