Search Results (2,798)

Transport of Golgi-localized proteins from the ER is mediated by the coat protein complex II (COPII) and its members, COPII inner coat subunit Sec24 and Secretion-associated Ras-related GTPase 1 (Sar1). Sar1 and Sec24 recognize cytosolic N-termini of glycosyltransferases (GTs) that contain peptide signals required for incorporation into COPII-coated vesicles. Xyloglucan Xylosyltransferases (XXTs) are required for xyloglucan (XyGs) biosynthesis and must be transported to the Golgi for proper function. In this study, we demonstrated that XXTs interact with AtSar1 in the COPII complex but not with AtSec24, which was previously reported to be the main recruiter of cargo proteins into COPII-coated vesicles. The mutation of the arginine to glutamine residues of di-arginine motifs in the N-termini of XXTs caused protein mislocalization and significantly reduced the strength of the interaction with AtSar1. These mutations caused 90% of XXTs to either remain in the ER or localize to small non-Golgi compartments. In turn, such mislocalization significantly suppressed the recovery of XyGs biosynthesis in Arabidopsis thaliana (Arabidopsis) mutants (xxt1xxt2 and xxt3xxt4xxt5), failing to restore their root phenotypes to normal. Our results demonstrate the interaction between cargo and AtSar1, highlighting the critical role of di-arginine motifs in this interaction. These results provide new insights into the mechanism of ER-to-Golgi delivery of plant GTs, which significantly advances our understanding of polysaccharide biosynthesis in the Golgi and the enzymes responsible for it. Full article

Cardiovascular–kidney–metabolic syndrome is a novel concept defined by the American Heart Association, highlighting the complex interactions between the cardiovascular system, kidney function and metabolic risk factors. Poor cardiovascular–kidney–metabolic health is increasingly prevalent worldwide, giving rise to a need to optimize early detection of cardiovascular dysfunction. Heart failure is one of the most prevalent forms of cardiovascular disease in patients with chronic kidney disease and metabolic risk factors, but screening and diagnostic strategies remain challenging. Current guidelines endorse the use of prediction scores, as well as a biomarker-based strategy in patients at increased risk. Despite evidence supporting the use of biomarkers such as natriuretic peptides, there are considerable limitations to their use in the setting of cardiovascular–kidney–metabolic syndrome. Moreover, there is mounting evidence supporting the use of other biomarkers reflecting underlying mechanisms leading to heart failure. The aim of this review is to assess current approaches to screening for and diagnosing heart failure in cardiovascular–kidney–metabolic syndrome, highlighting the strengths and pitfalls of gold-standard and emerging biomarkers, while also addressing gaps in evidence and future research directions. Validation of screening biomarkers and development of multimarker prediction scores could impact clinical practice and reduce the growing morbidity and mortality in cardiovascular–kidney–metabolic syndrome. Full article

Background: There is currently increasing interest in atypical opioid compounds capable of expanding their clinical applications beyond pain management, including the treatment of psychiatric disorders and substance abuse. In this context, the cyclotetrapeptide c[Trp-Phe-D-Pro-Phe] (CJ-15,208, 1) and its derivatives represent an unusual class of opioid peptides. This compound was found to be a mixed KOR/MOR antagonist in vitro, but it acted as an agonist in vivo. For its diverse analogues, it appeared that receptors’ affinity, selectivity, and agonist/antagonist activity greatly varied upon modifications to backbone geometry and the 3D display of pharmacophores. Methods: We utilized NMR, molecular dynamics, and molecular docking to analyze 3D structures and pharmacodynamic properties of selected representative cyclopeptide analogues of 1. Results: The simulations support that, despite its contradictory functional activity in vitro and in vivo, 1 can bind to the active conformation of receptors in an agonist-like fashion. In general, Trp appeared to be the fundamental pharmacophore in the ligand–receptor complexes. In particular, agonists showed a direct interaction between the indole ring and the carboxylate of the conserved Asp(3:32). Conclusions: These studies support a distinctive pharmacodynamic model for this class of compounds, potentially useful for the design of opioid compounds with novel binding/activity profiles and improved therapeutic effects. Full article

The topic of improving the strength and performance properties of secondary polyamide materials as part of their functional modification is a very relevant area of expanding the possibilities of secondary use of plastic waste. The article aims to conduct a systematic study of the combined modification of polyamide waste agglomerate by six different types of carbon materials to improve their technological and strength properties. PA6 waste agglomerate from polyamide clothing items, tights, socks, and various carbon materials were studied: masterbatch for polyamides MW-PA CB10, brown coal humic substances, coke residue from pyrolysis, a mixture of plastic waste, and finely dispersed coal enrichment waste. A sustainable polymer composite based on a modified agglomerate of PA6 waste was obtained by extruding pre-prepared raw materials in a single-screw extruder. The structural and morphological analysis of the studied carbon materials showed that, within the framework of the combined modification of polyamide-6 waste agglomerate, they should perform different functions related to their distinct morphology and chemical composition. Thus, humic substances can act as functional modifiers and compatibilizers due to their nanodispersity and a wide range of active chemical groups. In contrast, coke residue from pyrolysis and coal enrichment waste will act as a functional filler to improve the complex strength properties of sustainable polymer composites. As part of a study on the effect of modifying polyamide-6 waste agglomerate by carbon materials on its complex technological characteristics, it was demonstrated that humic substances enhance sustainable polymer composite’s technological properties by increasing the melting temperature and melt flow index while reducing density. The increase in the functional effect of humic substances is due to the growth of a wide range of active chemical groups (hydroxyl, carboxyl, peptide). During the initial oxidation of brown coal, the coke residue from pyrolysis and coal enrichment waste served as a filler, increasing the sustainable polymer composite’s density and melt flow index. As part of the study of the effect of modification by carbon materials on the complex strength characteristics of polyamide-6 waste agglomerate, it was shown that all carbon materials studied, except for coke residue, improve the strength characteristics of polyamide-6 waste agglomerate. The optimal content of different types of humic substances is 0.5% wt., while the sustainable polymer composite’s impact strength and breaking stress during bending increase with the increase in the functionalization of humic substances during the oxidation of brown coal. It has been shown that the combination of small amounts of oxidized humic substances at the level of 0.5% by weight, as a functional additive with a masterbatch MW-PACB10 in an amount of 2–3.5%wt., provides materials with increased impact strength from 23 to ~48 kJ/m² and bending fracture stress from 115 to ~135 MPa, which allows returning secondary PA6 waste to the “traditional areas of primary PA6” in the manufacture of general technical parts and products. Full article

Long COVID is a complex condition characterized by persistent symptoms following SARS-CoV-2 infection. Understanding its biochemical mechanisms is essential for effective management and treatment strategies. Objective: This study investigated biochemical alterations associated with long COVID in unvaccinated individuals presenting symptoms persisting for more than six months, highlighting the prolonged nature of the condition and its systemic and neurological manifestations. A cross-sectional study was conducted with 60 unvaccinated patients at least six months post-COVID-19 infection. Serum biomarkers, including C-reactive protein (CRP), interleukin-6 (IL-6), N-terminal pro-brain natriuretic peptide (NT-proBNP), and irisin, were analyzed. Correlations between these biomarkers and persistent symptoms were assessed using statistical regression models. Elevated CRP levels were significantly associated with persistent respiratory and musculoskeletal symptoms, suggesting ongoing inflammation. Increased IL-6 levels correlated with fatigue and musculoskeletal complaints. NT-proBNP elevations were linked to cardiovascular manifestations, including dyspnea and chest pain. A positive correlation between irisin and persistent sensory impairments, such as anosmia and dysgeusia, indicates potential neuroinflammatory mechanisms. This study highlights that persistent inflammation plays a critical role in long-term (>6 months) post-COVID manifestations. Monitoring biomarkers such as CRP, IL-6, NT-proBNP, and irisin may enhance understanding and management of prolonged post-COVID conditions. Full article

Baijiu distillers’ grains (BDGs, Jiuzao) are produced in large quantities by China’s solid-state Baijiu industry and remain largely underutilized. BDGs retain substantial levels of dietary fibers, proteins and peptides, phenolic compounds, and fermentation-derived metabolites. This review summarizes recent advances in the recovery, structural characterization, and functional evaluation of BDG-derived components, with particular emphasis on non-starch polysaccharides as the core functional fraction. We discuss how solid-state fermentation and processing conditions influence the structural features of arabinoxylan-rich polysaccharides, polysaccharide–protein associations, and feruloylated motifs, and how these characteristics relate to reported antioxidant activity, gut microbiota modulation, immunoregulatory effects, and prebiotic fermentation behavior. Beyond isolated fractions, growing evidence highlights the importance of matrix-level interactions among polysaccharides, peptides, and phenolics in shaping functionality within complex food systems. In parallel, emerging application opportunities in functional foods, nutraceutical formulations, biomaterials, and cascade utilization frameworks are summarized from a sustainable processing perspective. Finally, key challenges for industrial translation are identified, including batch variability, structure–function standardization, scalable and food-grade processing, safety evaluation, and regulatory considerations. Full article

The vascular cambium serves as the fundamental meristem for wood formation. It determines wood biomass and structural properties by balancing self-renewal with the bidirectional production of xylem and phloem. This process is controlled by a complex network of peptides, transcription factors, and phytohormones. These regulatory networks coordinate cambial stem cell activity, balancing cell division and differentiation. Additionally, layers of regulation such as chromatin state, protein stability, and non-coding RNAs add significant complexity to these networks. Emerging single-cell and spatial transcriptomics, together with quantitative modeling, now resolve cambial heterogeneity, predicting the dynamic characteristics of wood formation. This review synthesizes current knowledge of cambial regulation, highlighting how feedback loops, spatial gradients, and dynamic signaling networks collectively orchestrate the predictive potential for improving cambial activity and wood formation. Full article

The majority of approved drug products comprise formulations of either chemically synthesized small molecules or large molecular entities derived from living cells, commonly referred to as biologics. Over the past two decades, there has been remarkable growth in the approval of biologics for a variety of disorders, including respiratory diseases. The preference for biologics stems from their high target specificity, strong binding affinity, and favorable safety profiles. Most approved biologics are peptides or proteins, which are unsuitable for oral administration due to negligible bioavailability, resulting from their large molecular size, polarity, and susceptibility to enzymatic degradation in the gastrointestinal tract. Consequently, the majority of biologics are administered parenterally, delivering the drug systemically to reach target sites. However, achieving therapeutic concentrations of locally acting respiratory drugs in the lungs via systemic delivery often requires high doses, which increases the risk of adverse effects. For respiratory disorders, nasal and pulmonary drug deliveries are the preferred noninvasive routes. These routes bypass gastrointestinal and first-pass metabolism and deliver therapeutic agents directly to their local site of action. This approach enables a faster onset of action, reduces the required dose by orders of magnitude, and significantly lowers the risk of systemic adverse effects. These advantages have driven the successful development of inhaled formulations for certain rescue and maintenance medications that were originally administered orally or parenterally. Despite this, treatment options for respiratory diseases remain largely limited to small molecules, with only a single inhaled biologic approved in 1993, even though several parenterally administered biologics have since been approved for pulmonary disorders. The scarcity of inhaled biologics is primarily due to the inherent complexity of these drug substances, which impacts all stages of product development, including manufacturing, characterization, purification, stability, formulation design, delivery, and preclinical and clinical evaluations of safety and efficacy. Additionally, sponsors’ interest in developing inhaled biologics may be tempered by the lack of regulatory guidance addressing the multidisciplinary and intricate nature of their development. This article, together with the accompanying review, addresses both regulatory considerations and scientific challenges in the development of inhaled biologics. To the authors’ knowledge, these works represent seminal efforts to examine available regulatory guidance and the applicable literature across various phases of product development beyond safety and efficacy evaluations. We examined the formal regulatory expectations and summarized the requirements as they apply to inhaled products and inhaled biologic protein therapeutics. In parallel, we explored scientifically relevant considerations in the development of inhalation-specific protein therapeutics for which regulatory guidance remains limited, evolving, or absent. While they should not be considered definitive, it is hoped that these contributions will stimulate scientific and regulatory interest, ultimately promoting the identification and resolution of gaps to advance the development of locally acting biologics and address unmet patient needs. Full article

Background: Type 2 diabetes mellitus (T2DM) is commonly managed with complex pharmacotherapy combined with dietary modification, which increases the risk of clinically relevant drug–food interactions (DFIs). Despite their potential impact on treatment efficacy and safety, patient knowledge of DFIs—particularly in the context of modern therapies such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs)—remains insufficiently explored. Methods: This cross-sectional study assessed knowledge of DFIs among 103 adults with T2DM using a self-administered, expert-validated questionnaire. Data on sociodemographic characteristics, clinical variables, anti-diabetic therapy (including GLP-1 RAs), sources of education, and attendance at dietary consultations were collected. Knowledge scores were calculated based on correct responses and categorized into tertiles (low, moderate, high). Associations were analyzed using non-parametric tests. Multivariable logistic regression was performed to identify independent predictors of moderate-to-high DFI knowledge. Results: Substantial gaps in DFI knowledge were identified, particularly regarding interactions involving dietary fiber, dairy products, grapefruit juice, and nutrient deficiencies associated with long-term pharmacotherapy. Knowledge level was not significantly associated with age, educational attainment, diabetes duration, or GLP-1 RA use. Female sex was associated with higher knowledge in univariate analysis (p = 0.026); however, this association did not remain significant in the multivariable regression model. Attendance at at least one dietary consultation in the previous year was significantly associated with higher knowledge levels (p = 0.041) and remained an independent predictor in multivariable analysis (OR = 2.31; 95% CI: 1.04–5.15; p = 0.039). Most participants reported not receiving prior education on DFIs, while expressing a strong need for more frequent counseling. Conclusions: Patients with T2DM demonstrate insufficient knowledge of clinically relevant DFIs, including selected issues related to GLP-1 RA therapy. Attendance at structured dietary consultations was independently associated with higher levels of DFI knowledge; however, the directionality and causality of this relationship cannot be established. Given the cross-sectional design and the assessment of knowledge rather than behavioral or clinical outcomes, these findings should be interpreted as hypothesis-generating. Further longitudinal and interventional studies are required to determine whether improved DFI knowledge translates into meaningful changes in dietary behavior, treatment adherence, or metabolic outcomes. Full article

With the intensification of social aging and the improvement of living standards, delaying aging has become a focus of common concern, especially in regard to skin aging. Although collagen peptides have been widely reported as therapeutic agents in relieving skin aging, the molecular mechanisms remain inadequately elucidated. This review emphasizes that the alleviation of skin aging by collagen peptides is a systematic and complex process, including the removal of reactive oxygen species, inhibition of inflammation, inhibition of extracellular matrix (ECM) degradation and melanin deposition, activation of lysosomal and mitochondrial function, and promotion of ECM synthesis. It also highlights that lysosomes and mitochondria may be the key organelles that regulate collagen peptides to alleviate skin aging. Current research on the mechanism of collagen peptides in alleviating skin aging still requires bold breakthroughs and should not be confined to the transforming growth factor (TGF-β)/Smad, mitogen-activated protein kinase, and nuclear factor kappa-B pathways. In addition, many natural antioxidant components have been proven to alleviate skin aging by regulating organelle function. Therefore, the regulatory effects of collagen peptides with antioxidant activity on mitochondrial and lysosome functions in aging skin need more attention and exploration, which is of great significance for further research on precise skin care and targeted anti-skin aging therapy. Full article

Human-induced pluripotent stem cells (hiPSCs) have an innate ability to differentiate into the three germ layers: the ectoderm, endoderm, and mesoderm. By using targeted differentiation methods and carefully controlling growth factors, morphogens, and signaling modulators, hiPSCs can be guided to develop into specific lineage cell types. For clinical applications of hiPSCs and their derivatives, it is crucial to use xenogen-free, chemically defined culture media, reagents, recombinant growth factors, morphogens, and extracellular matrix (ECM) scaffolds. One major obstacle is the widespread use of Matrigel as an hiPSC culture matrix. Matrigel, derived from Engelbreth–Holm–Swarm (EHS) mouse sarcoma, is an extract of basement membrane material with a complex, poorly defined, and variable composition. It also exhibits batch-to-batch variability in mechanical and biochemical properties and is difficult to modify, which limits its rational use in the production of therapeutic cells and organoids. Synthetic ECM matrices and scaffolds offer a promising alternative because they can have a fully defined composition, highly tunable physical properties, surface modifications, and functionalization with recombinant signaling peptides and growth factors. This provides a suitable microenvironment for hiPSC culture and the directed differentiation towards lineage-specific cells and organoid development, and can be used in clinical-grade tissue transplantation and regenerative medicine. Full article

Background/Objectives: Vaccines targeting melanoma antigens can elicit CD8⁺ T cell responses, but a growing body of work suggests CD4⁺ T cells also play a role in tumor control. Induction of CD4⁺ cells may also support B cells in producing tumor antigen-specific antibodies (Abs). We investigated Abs induced by vaccination with a cocktail of six class II MHC-restricted melanoma peptides (6MHP) and the effect of adjuvant type on Ab isotypes. We hypothesized that the vaccines would induce Abs that respond to different epitopes on individual peptides and that IgG isotype distribution varies with different vaccine adjuvants. Methods: Sera from patients who received a 6MHP vaccine were evaluated with enzyme-linked immunosorbent assays to map epitopes for polyclonal Ab responses to synthetic melanoma peptides. IgG isotypes of Ab responses to 6MHP were assessed in patients who received one of four adjuvants (Incomplete Freund’s Adjuvant (IFA) alone, IFA + polyICLC, IFA + systemic metronomic cyclophosphamide (mCy), or IFA + polyICLC + systemic mCy) to characterize IgG isotype distribution. Results: Epitope mapping revealed that at least 50% of patients had responses to two or more epitopes on the same peptide, suggesting polyclonal Ab responses. Serum evaluation for IgG isotypes showed predominant induction of IgG1 and IgG3. Mean total IgG was highest when IFA and polyICLC were used in combination. Patients who received TLR3 agonist polyICLC had significantly higher concentrations of total IgG, IgG1, and IgG3 compared to patients who did not receive polyICLC. Conclusions: Vaccine-induced Abs may respond to multiple epitopes within the same peptide, warranting further studies into their ability to facilitate antigen uptake and presentation through the formation of large immune complexes. The findings also show that adding polyICLC to IFA can significantly enhance Ab responses. Collectively, this work underscores the immunologic potential of peptide-induced Abs and the importance of adjuvant selection in cancer vaccine design. Full article

Alcohol exposure affects immune regulation and tissue homeostasis. Antimicrobial peptides (AMPs) are essential components of innate immunity, not only defending against pathogens but also modulating processes such as inflammation. However, their tissue-specific regulation in response to alcohol remains poorly characterized, particularly in humans after acute intoxication. We evaluated the expression of AMPs in the peripheral blood of patients with alcohol use disorder (AUD, n = 9), individuals with acute alcohol consumption (AAC, n = 9), and controls using quantitative polymerase chain reaction (qPCR). Additionally, we analyzed AMP expression in selected tissues of mice exposed to chronic ethanol feeding (National Institute on Alcohol Abuse and Alcoholism model for 5 days) and performed a systematic review of AMP regulation in alcohol-related disorders (2005–2025; n = 36 studies, reflecting a limited and heterogeneous body of available evidence). Human cathelicidin antimicrobial peptide (LL-37), lipopolysaccharide-binding protein (LBP), and bactericidal/permeability-increasing protein (BPI) were significantly upregulated in patients with AUD, whereas LL-37 and LBP were significantly upregulated in AAC. In the livers of ethanol-fed mice, LEP2, LCN2, and LBP levels were markedly increased, whereas LL-37 and LEP1 were downregulated. Duodenal tissue exhibited upregulation of DEFB1. In adipose tissue, DEFA2 was significantly increased in peripheral depots, whereas only LCN2 was upregulated in brain tissue. The systematic review demonstrated complex, heterogeneous, and organ-dependent AMP regulation and also highlighted the paucity of human data on AAC, a gap that our study partially addresses. Our results are consistent with the hypothesis that selected AMPs may serve as candidate markers of organ damage or microbial translocation and as possible therapeutic targets, a hypothesis that requires confirmation in larger, adequately powered studies. Full article

Background/Objectives: Polysaccharide-protein conjugate vaccines have proven highly effective, yet they remain limited by manufacturing complexity, cost, and variable performance across serotypes, while carrier proteins can add unwanted immunological and production burdens. To address these constraints, we explored a carrier-protein-free conjugate vaccine concept in which a broadly MHC class II-binding helper epitope (PADRE) replaces the conventional protein carrier to provide T-cell help for a pneumococcal capsular polysaccharide antigen. Methods: Using serotype 15C CPS as a model, we generated CPS–PADRE conjugates and compared designs with or without a putative cleavable motif (RR) at the junction, alongside a conventional protein conjugate as a benchmark. Results: In mice, the CPS–protein conjugate induced the strongest CPS-specific IgG response, whereas CPS–PADRE conjugates elicited clear but overall lower antibody levels. Notably, incorporation of the cleavable motif did not improve immunogenicity and instead reduced humoral responses relative to the non-cleavable design. Conclusion: These findings support the feasibility of carrier-protein-free polysaccharide-peptide conjugate vaccines, while highlighting that cleavable junctions are not universally advantageous and must be empirically optimized for polysaccharide-helper epitope architectures. Full article

Emerging mosquito-borne flaviviruses, such as Dengue virus (DENV) and Zika virus (ZIKV), pose major global public health threats due to their geographic expansion, climate change, and the absence of effective antiviral therapies. Antiviral development against these pathogens has primarily focused on two complementary strategies. On the one hand, the blocking of viral replication by directly inhibiting essential viral enzymes, and on the other, enhancing the host’s innate immune defenses via targeted activation of intracellular antiviral pathways. Among the viral proteins required for replication, the NS2B–NS3 protease complex is one of the most conserved and druggable targets, prompting extensive efforts to design both covalent and non-covalent inhibitors. Covalent inhibitors, such as boronic acids, aldehydes, trifluoromethyl ketones, phenoxymethylphenyl derivatives, and α-ketoamides, form irreversible or slowly reversible bonds with the catalytic serine residue (Ser 135), producing long-lasting and high-affinity suppression of protease activity. In parallel, several classes of non-covalent, particularly allosteric, inhibitors have emerged as promising alternatives with improved specificity and reduced off-target reactivity. A complementary antiviral strategy involves the use of agonists of key innate immune sensors such as TLRs, RIG-I, and the cGAS–STING axis, which mediate the release of interferons (IFNs). This review brings together current knowledge on these two mechanistically distinct yet convergent approaches, highlighting how both can ultimately restrict flavivirus replication. Future opportunities involving modified peptide scaffolds, advanced delivery systems, and drug-repurposing strategies are finally discussed for the development of next-generation therapeutics against DENV and ZIKV. Full article