Molecular Mechanism Of Action Research Articles

Regulatory mechanism of Reelin activity: a platform for exploiting Reelin as a therapeutic agent

Reelin is a secreted glycoprotein that was initially investigated in the field of neuronal development. However, in recent decades, its role in the adult brain has become increasingly important, and it is now clear that diminished Reelin function is involved in the pathogenesis and progression of neuropsychiatric and neurodegenerative disorders, including schizophrenia and Alzheimer’s disease (AD). Reelin activity is regulated at multiple steps, including synthesis, posttranslational modification, secretion, oligomerization, proteolytic processing, and interactions with extracellular molecules. Moreover, the differential use of two canonical receptors and the presence of non-canonical receptors and co-receptors add to the functional diversity of Reelin. In this review, I summarize recent findings on the molecular mechanisms of Reelin activity. I also discuss possible strategies to enhance Reelin’s function. A complete understanding of Reelin function and its regulatory mechanisms in the adult central nervous system could help ameliorate neuropsychiatric and neurodegenerative disorders.

Molecular mechanism of ligand recognition and activation of lysophosphatidic acid receptor LPAR6

Lysophosphatidic acid (LPA) exerts its physiological roles through the endothelialdifferentiation gene (EDG) family LPA receptors (LPAR1-3) or the non-EDG family LPA receptors (LPAR4-6). LPAR6 plays crucial roles in hair loss and cancer progression, yet its structural information is very limited. Here, we report the cryoelectron microscopy structure of LPA-bound human LPAR6 in complex with a mini G13 or Gq protein. These structures reveal a distinct ligand binding and recognition mode that differs significantly from that of LPAR1. Specifically, LPA uses its charged head to form an extensive polar interaction network with key polar residues on the extracellular side of transmembrane helix 5-6 and the extracellular loop 2. Structural comparisons and homology analysis suggest that the EDG and non-EDG families use two distinct modes for LPA binding. The structural observations are validated through functional mutagenesis studies. We further uncover the mechanisms of LPAR6 activation and principles of G-protein coupling. The structural information revealed by our study lays the groundwork for understanding LPAR6 signaling and provides a rational basis for designing compounds targeting LPAR6.

Exploring the Therapeutic Potential of Plumbagin: Its Current Applications in Cancer and Neuropsychiatric Disorders.

Plumbagin (PL) is an important natural active ingredient in traditional Chinese medicine derived from the Plumbago zeylanica L. It possesses a variety of biological activities, such as anti-inflammatory, anticancer, antioxidant, antimicrobial, and neuroprotective properties, and has great potential for utilization in disease treatment and prevention. Cancer and neurological and psychiatric diseases are two major categories of diseases that currently threaten the physical and mental health of human beings, and their increasing incidence is causing a serious economic burden to all humanity. Based on the physical and chemical properties and pharmacokinetics of plumbagin, this study will focus on summarizing the application research status of plumbagin in cancer, neurological, and psychiatric diseases and analyze the molecular targets and action pathways of its therapeutic efficacy. This study will also briefly summarize the application of plumbagin in other diseases, as well as the existing problems and future development direction of plumbagin in clinical application, aiming to provide new perspectives and strategies for the development of new drugs and the treatment of existing diseases.

Inflammation and Cancer Development: Basic Mechanisms and Evidence of its Regulation by Hibiscus sabdariffa Natural Extracts

Background: Hibiscus sabdariffa is a plant used in traditional medicine for intestinal treatments and nowadays for critical diseases like hypertension, diabetes, and cancer. Multidisciplinary approaches have demonstrated, through Hibiscus sabdariffa extracts, anti-inflammation and anti-cancer beneficial properties from compounds like phenols, flavonoids, and anthocyanins that are ubiquitously distributed in whole plants. Objective: The objective of this study is to identify the bioactive compounds and their underlying mechanisms of action that drive the anti-cancer and anti-inflammatory properties of Hibiscus sabdariffa extracts Methods: We searched databases for publications in English from all years that reported beneficial anti-inflammation and anti-cancer properties from Hibiscus sabdariffa extracts and their proposed mechanism of action. We used Pubmed, Google Scholar, Scopus, and ScienceDirect for original articles that included different Hibiscus sabdariffa extracts evaluated for their anti-inflammation, and anti-cancer properties, using the following search terms: “H. sabdariffa”, “H. sabdariffa extracts”, “H. sabdariffa and inflammation”, and “H. sabdariffa and cancer”. Some articles from the reference list were used to collect additional information, and we used 73 articles in total. Results: In general, extracts from Hibiscus sabdariffa are obtained by different methods that affect the final concentration of the compounds. Several in vivo and in vitro experiments show their antiinflammatory and anti-cancer properties. Conclusion: Hibiscus sabdariffa extracts have the potential bioactivity to modulate inflammation and cancer in several cellular and molecular mechanisms of action involving the downregulation of key signaling pathways such as NFκB, MAPK, BCL-2, p53, among others, and the upregulation of protective pathways such as Nrf2. However, research needs to be further evaluated on the exact compounds that have this effect, in order to know if the extracts work individually or synergistically.

The Role of Exerkines in the Treatment of Knee Osteoarthritis: From Mechanisms to Exercise Strategies.

With the increasing prevalence of knee osteoarthritis (KOA), the limitations of traditional treatments, such as their limited efficacy in halting disease progression and their potential side effects, are becoming more evident. This situation has prompted scientists to seek more effective strategies. In recent years, exercise therapy has gained prominence in KOA treatment due to its safety, efficacy, and cost-effectiveness, which are underpinned by the molecular actions of exerkines. Unlike conventional therapies, exerkines offer specific advantages by targeting inflammatory responses, enhancing chondrocyte proliferation, and slowing cartilage degradation at the molecular level. This review explores the potential mechanisms involved in and application prospects of exerkines in KOA treatment and provides a comprehensive analysis of their role. Studies show that appropriate exercise not only promotes overall health, but also positively impacts KOA by stimulating exerkine production. The effectiveness of exerkines, however, is influenced by exercise modality, intensity, and duration of exercise, making the development of personalized exercise plans crucial for KOA patients. Based on these insights, this paper proposes targeted exercise strategies designed to maximize exerkine benefits, aiming to provide novel perspectives for KOA prevention and treatment.

The Potential of Polyphenols in Modulating the Cellular Senescence Process: Implications and Mechanism of Action

Background: Cellular senescence is a biological process with a dual role in organismal health. While transient senescence supports tissue repair and acts as a tumor-suppressive mechanism, the chronic accumulation of senescent cells contributes to aging and the progression of age-related diseases. Senotherapeutics, including senolytics, which selectively eliminate senescent cells, and senomorphics, which modulate the senescence-associated secretory phenotype (SASP), have emerged as promising strategies for managing age-related pathologies. Among these, polyphenols, a diverse group of plant-derived bioactive compounds, have gained attention for their potential to modulate cellular senescence. Methods: This review synthesizes evidence from in vitro, in vivo, and clinical studies on the senolytic and senomorphic activities of bioactive polyphenols, including resveratrol, kaempferol, apigenin, and fisetin. The analysis focuses on their molecular mechanisms of action and their impact on fundamental aging-related pathways. Results: Polyphenols exhibit therapeutic versatility by activating SIRT1, inhibiting NF-κB, and modulating autophagy. These compounds demonstrate a dual role, promoting the survival of healthy cells while inducing apoptosis in senescent cells. Preclinical evidence indicates their capacity to reduce SASP-associated inflammation, restore tissue homeostasis, and attenuate cellular senescence in various models of aging. Conclusions: Polyphenols represent a promising class of senotherapeutics for mitigating age-related diseases and promoting healthy lifespan extension. Further research should focus on clinical validation and the long-term effects of these compounds, paving the way for their development as therapeutic agents in geriatric medicine.

Klebsiella pneumoniae T6SS impact in IBDs

Abstract Background and aims Our hypothesis is that Klebsiella pneumoniae (Kp) Type VI Secretion System (T6SS), normally used for bacteria competition during host colonization have a collateral impact on the host inflammatory pathway (Fig1). Our specific aims are to: (i) Characterize the impact of bacterial type VI Secretion System (T6SS) on host gut inflammation (ii) Develop a screen to identify T6SS inhibitors. Methods In vivo experiments involve infecting mice with Kp wild type (WT) and T6SS mutants to evaluate gut inflammation and immune response. Metagenomic analysis of IBD and CRC patients' microbiota will be conducted to assess T6SS gene enrichment. The molecular mechanism of T6SS activity and LPS release will be explored using various imaging and biochemical techniques. High-throughput screening of small molecule inhibitors targeting T6SS assembly will be performed, followed by validation in cellular models. The role of bacteria in tumorigenesis is increasingly recognized, yet our understanding of the underlying mechanisms remains incomplete, hindering the identification of new therapeutic strategies. It is therefore critical to decipher the bacterial mechanisms and their impact on the host to identify pathways that can be targeted from both sides. Anticipated impact Our preliminary data have uncovered a novel role of Type VI Secretion System (T6SS) role in gut inflammation. Building on our extensive expertise of this specific system, we will employ a multidisciplinary approach to inhibit T6SS. Inhibiting the T6SS could prevent both gut inflammation and Enterobacteria competition advantage in the gut, therefore reducing dysbiosis. Moreover, inhibition of bacterial virulence factors is an attractive strategy to complement antibiotic and anti-inflammatory treatments already in use.

Plant Polyphenols as Heart’s Best Friends: From Health Properties, to Cellular Effects, to Molecular Mechanisms of Action

Polyphenols are micronutrients found in fruits, vegetables, tea, coffee, cocoa, medicinal herbs, fish, crustaceans, and algae. They can also be synthesized using recombinant microorganisms. Interest in plant-derived natural compounds has grown due to their potential therapeutic effects with minimal side effects. This is particularly important as the aging population faces increasing rates of chronic diseases such as cancer, diabetes, arthritis, cardiovascular, and neurological disorders. Studies have highlighted polyphenols’ capacity to reduce risk factors linked to the onset of chronic illnesses. This narrative review discusses polyphenol families and their metabolism, and the cardioprotective effects of polyphenols evidenced from in vitro studies, as well as from in vivo studies, on different animal models of cardiac disease. This study also explores the molecular mechanisms underlying these benefits. Current research suggests that polyphenols may protect against ischemia, hypertension, cardiac hypertrophy, heart failure, and myocardial injury through complex mechanisms, including epigenetic and genomic modulation. However, further studies under nutritionally and physiologically relevant conditions, using untargeted multigenomic approaches, are needed to more comprehensively elucidate these mechanisms and firmly prove the cardioprotective effects of polyphenols.

DOP069 Guselkumab maintenance therapy mediates further improvements in intestinal immune homeostasis and mucosal healing in patients with ulcerative colitis

Abstract Background Guselkumab (GUS) is a dual-acting IL-23p19 subunit inhibitor that potently neutralises interleukin 23 (IL-23) and binds to CD64, a receptor on cells that produce IL-23.1 The QUASAR Phase 2b/3 studies have demonstrated efficacy and safety in induction and maintenance phases.2,3 The cellular and molecular mechanism of action of GUS induction was also previously reported.4 Here, the molecular changes that occur with maintenance treatment are presented. Methods At maintenance baseline, clinical responders to GUS induction treatment (n=568) were randomized 1:1:1 to GUS SC 200mg q4w, GUS SC 100mg q8w, or placebo (PBO; GUS withdrawal). Molecular analysis of the randomised population was performed comparing maintenance baseline (M0) to Week 44 (M44). Transcriptional profiling of colonic biopsies from 396 patients was performed using RNA sequencing and gene modules were evaluated for differential expression. Serum proteins were evaluated from 430 patients using a targeted inflammation panel and differential protein abundance was assessed. Results Clinically, both GUS SC maintenance dose regimens were highly efficacious and achieved the primary endpoint of clinical remission and all major secondary endpoints at M44 compared with PBO.2 Molecular analysis demonstrated a further significant downregulation of key inflammatory gene modules from M0 to M44 (all false discovery rate [FDR]<0.05) from that previously observed during induction.4 Unique to maintenance, gene modules related to intestinal mesenchymal biology (pericytes, fibroblasts and endothelium) showed even greater changes in maintenance compared to induction. An upregulation of gene modules representing healthy epithelial biology (crypt, goblet cells, M-cells) was also observed at M44 (Figure 1). Importantly, patients who achieved clinical remission at M44 demonstrated the most significant changes and gene module expression levels at M44 approximated those observed in non-IBD healthy controls, consistent with the profile of healthy colonic tissue. Serum analysis showed continued reductions in inflammatory proteins (e.g. IL-17A, IL-8, FDR <0.05) and several chemokines from M0 to M44, including CCL11 that has been linked to mesenchymal biology. By M44, GUS withdrawal demonstrated a reversal in the anti-inflammatory effects achieved at the end of induction. Conclusion GUS maintenance therapy for UC mediated further improvements in the anti-inflammatory and pro-healing effects achieved during induction. Moreover, this work provides evidence supporting a role for mesenchymal biology in tissue remodeling during maintenance. Together, these data provide molecular evidence supporting the robust clinical benefit of GUS maintenance therapy.

Nanoscale Manipulation of Single-Molecule Conformational Transition through Vibrational Excitation.

Controlling molecular actions on demand is a critical step toward developing single-molecule functional devices. Such control can be achieved by manipulating the interactions between individual molecules and their nanoscale environment. In this study, we demonstrate the conformational transition of a single pyrrolidine molecule adsorbed on a Cu(100) surface, driven by vibrational excitation through tunneling electrons using scanning tunneling microscopy. We identify multiple transition pathways between two structural states, each governed by distinct vibrational modes. The nuclear motions corresponding to these modes are elucidated through density functional theory calculations. By leveraging fundamental forces, including van der Waals interactions, dipole-dipole interactions, and steric hindrance, we precisely tune the molecule-environment coupling. This tuning enables the modulation of vibrational energies, adjustment of transition probabilities, and selection of the lowest-energy transition pathway. Our findings highlight how tunable force fields in a nanoscale cavity can govern molecular conformational transitions, providing a pathway to engineer molecule-environment interactions for targeted molecular functionalities.

Assessment of Self-Activation and Inhibition of Wheat Coiled-Coil Domain Containing NLR Immune Receptor Yr10CG.

Plant immunity is largely governed by nucleotide-binding leucine-rich repeat receptor (NLR). Here, we examine the molecular activation and inhibition mechanisms of the wheat CC-type NLR Yr10CG, a previously proposed candidate for the Yr10 resistance gene. Though recent studies have identified YrNAM as the true Yr10 gene, Yr10CG remains an important NLR in understanding NLR-mediated immunity in wheat. In this study, we found that the overexpression of either the full-length Yr10CG or its CC domain in Nicotiana benthamiana did not trigger cell death, suggesting a robust autoinhibitory mechanism within Yr10CG. However, we observed that mutations in the conserved MHD motif, specifically D502G, activated Yr10CG and induced cell death. Structural modeling indicated that this mutation disrupted key interactions within the MHD motif, promoting local flexibility and activation. We further explored the effector recognition potential of Yr10CG by creating chimeric proteins with Sr50 domains, revealing that both the NB-ARC and LRR domains are necessary for effector recognition, while the CC domain likely functions in downstream immune signaling. Additionally, disrupting membrane localization through an L11E mutation abolished Yr10CG self-activation, suggesting a requirement for membrane association in immune activation. Our findings contribute to the understanding of CC-NLR activation and autoinhibition mechanisms, highlighting the potential of Yr10CG in NLR engineering for crop resistance improvement.

Uncovering Psychedelics: From Neural Circuits to Therapeutic Applications.

Psychedelics, historically celebrated for their cultural and spiritual significance, have emerged as potential breakthrough therapeutic agents due to their profound effects on consciousness, emotional processing, mood, and neural plasticity. This review explores the mechanisms underlying psychedelics' effects, focusing on their ability to modulate brain connectivity and neural circuit activity, including the default mode network (DMN), cortico-striatal thalamo-cortical (CSTC) loops, and the relaxed beliefs under psychedelics (REBUS) model. Advanced neuroimaging techniques reveal psychedelics' capacity to enhance functional connectivity between sensory cerebral areas while reducing the connections between associative brain areas, decreasing the rigidity and rendering the brain more plastic and susceptible to external changings, offering insights into their therapeutic outcome. The most relevant clinical trials of 3,4-methylenedioxymethamphetamine (MDMA), psilocybin, and lysergic acid diethylamide (LSD) demonstrate significant efficacy in treating treatment-resistant psychiatric conditions such as post-traumatic stress disorder (PTSD), depression, and anxiety, with favorable safety profiles. Despite these advancements, critical gaps remain in linking psychedelics' molecular actions to their clinical efficacy. This review highlights the need for further research to integrate mechanistic insights and optimize psychedelics as tools for both therapy and understanding human cognition.

Systematic analysis of molecular mechanisms of action of essential macro- and micronutrients on the neurotransmitter and vasodilator molecule nitric oxide (NO)

Maintaining adequate levels of nitric oxide (NO) in the blood and other body tissues is necessary for the regulation of vascular tone, blood pressure, maintenance of oxygen metabolism and endothelial function. NO is also involved in regulating the balance of excitatory (glutamate) and inhibitory (gamma-aminobutyric acid) neurotransmission. Nutritional factors profoundly affect NO metabolism. Systematic computer analysis of 26,103 publications by methods of topological approach to recognition allowed to identify the most crucial fields of clinical research assessing relationships between NO metabolism and nutrients: arginine-derived NO synthase-driven NO production, nitrate-containing products, folates and vitamin B12 in NO homeostasis (including the effects of modifications of the vitamin B12 molecule), other B vitamins (B1, B2, B7), antioxidant vitamins (C and E), hormone-like vitamins D3 and A, electrolytes magnesium and calcium, participation of the microbiome in NO production.

β-Sitosterol modulates osteogenic and adipogenic balance in BMSCs to suppress osteoporosis via regulating mTOR-IMP1-Adipoq axis.

Osteoporosis (OP) is a prevalent global health concern, impacting millions of individuals, especially the elderly. The etiology of senile OP is associated with the imbalance of osteogenic and adipogenic differentiation in the bone marrow mesenchymal stem cells (BMSCs). The imbalance of BMSCs differentiation fate will leading to bone loss and lipids accumulation. β-sitosterol, a naturally occurring phytosterol which is abundant in plants and has a similar structure to cholesterol, demonstrates diverse bioactivities, including lipid-lowering effect and osteogenesis-inducing effects. These effects indicate that β-sitosterol might have anti-OP effects. Nevertheless, the precise mechanism underlying β-sitosterol's anti-osteoporotic efficacy via modulating BMSCs differentiation fate remains obscure. This study endeavors to elucidate whether β-sitosterol has the potential to augment the osteogenic differentiation of BMSCs while mitigating their adipogenic differentiation, thereby exerting an anti-OP effect; and to reveal its molecular mechanisms of action. In this study, a dosage form HP-β-cyclodextrin-coated β-sitosterol was developed for intragastric administration in mice to enhancing its bioavailability. Subsequently by using an integrative approach encompassing bioinformatics, computer molecular simulations, high-throughput sequencing, and in vitro/vivo as well as in-tube experiments, we investigated the anti-osteoporotic and bone healing effects of β-sitosterol and delineated its underlying mechanisms. Our findings demonstrate that β-sitosterol exhibits anti-osteoporotic and bone healing effects both in vitro and in vivo by modulating the osteogenic and adipogenic differentiation of BMSCs. Mechanistically, these effects are mediated through the direct inhibition of mTOR's kinase activity independent of mediating autophagy, leading to the suppression of the mTOR-IMP1-Adipoq axis in BMSCs. These results unveil β-sitosterol as a promising therapeutic agent for OP, shedding light on its underlying mechanisms. This research contributes potential candidates for diagnostic and therapeutic interventions in the realm of OP.

Botulinum Toxin: A Comprehensive Review of Its Molecular Architecture and Mechanistic Action.

Botulinum toxin (BoNT), the most potent substance known to humans, likely evolved not to kill but to serve other biological purposes. While its use in cosmetic applications is well known, its medical utility has become increasingly significant due to the intricacies of its structure and function. The toxin's structural complexity enables it to target specific cellular processes with remarkable precision, making it an invaluable tool in both basic and applied biomedical research. BoNT's potency stems from its unique structural features, which include domains responsible for receptor recognition, membrane binding, internalization, and enzymatic cleavage. This division of labor within the toxin's structure allows it to specifically recognize and interact with synaptic proteins, leading to precise cleavage at targeted sites within neurons. The toxin's mechanism of action involves a multi-step process: recognition, binding, and catalysis, ultimately blocking neurotransmitter release by cleaving proteins like SNAP-25, VAMP, and syntaxin. This disruption in synaptic vesicle fusion causes paralysis, typically in peripheral neurons. However, emerging evidence suggests that BoNT also affects the central nervous system (CNS), influencing presynaptic functions and distant neuronal systems. The evolutionary history of BoNT reveals that its neurotoxic properties likely provided a selective advantage in certain ecological contexts. Interestingly, the very features that make BoNT a potent toxin also enable its therapeutic applications, offering precision in treating neurological disorders like dystonia, spasticity, and chronic pain. In this review, we highlight the toxin's structural, functional, and evolutionary aspects, explore its clinical uses, and identify key research gaps, such as BoNT's central effects and its long-term cellular impact. A clear understanding of these aspects could facilitate the representation of BoNT as a unique scientific paradigm for studying neuronal processes and developing targeted therapeutic strategies.

Unraveling the Beneficial Role of Resveratrol in Fructose-Induced Non-Alcoholic Steatohepatitis with a Focus on the AMPK/Nrf2 Signaling Axis.

Background and Objectives: High fructose intake is associated with non-alcoholic fatty liver disease (NAFLD), a chronic liver disease that is on the rise worldwide. New alternatives for treatment, such as bioactive phytochemicals, are needed. The aim of this study was to investigate the beneficial role of resveratrol in treating non-alcoholic steatohepatitis (NASH). Materials and Methods: Sixty male albino rats were allocated to three groups: group I, the normal control group; group II, the fructose-enriched diet group (FED), which was fed a 70% fructose diet for six weeks to induce NASH; and group III, the resveratrol-FED group (RES + FED), which was given the same FED diet plus an oral dose of 70 mg/kg resveratrol (RES) every day for an additional six weeks. We performed histological evaluations and assessed blood lipids and liver enzymes to study resveratrol's impact on NASH. Quantitative real-time PCR was used to assess the mRNA expression of nuclear factor E2-related factor 2 (Nrf2) in the liver samples. ELISA was used to measure Beclin 1, AMPK, IL-6, and the DNA-binding activity of Nrf2. Oxidative stress indicators, including GSH, SOD, and MDA, were evaluated spectrophotometrically. Results: Resveratrol effectively alleviated the biochemical and histopathological abnormalities associated with NASH, improving autophagy by raising Beclin 1 levels while reducing inflammation by decreasing IL-6 levels. Furthermore, resveratrol restored the liver architecture and the oxidative balance, as evidenced by the decreased MDA levels and improved antioxidant status via elevated GSH and SOD activities, as well as the activation of the AMPK/Nrf2 signaling axis. Conclusions: This study specifically examines resveratrol's therapeutic effects in a high-fructose diet-induced NASH model, focusing on the AMPK/Nrf2 signaling pathway to address oxidative stress and autophagy, providing novel insights into its molecular mechanism of action. Resveratrol reduces NASH by boosting autophagy and activating the AMPK/Nrf2 pathway. These findings underscore the potential of resveratrol as a promising therapeutic agent that can support treatment alongside conventional medications in the management of non-alcoholic steatohepatitis (NASH).

Profiling Tel1 Signaling Reveals a Non-Canonical Motif Targeting DNA Repair and Telomere Control Machineries.

The stability of the genome relies on Phosphatidyl Inositol 3-Kinase-related Kinases (PIKKs) that sense DNA damage and trigger elaborate downstream signaling responses. In S. cerevisiae, the Tel1 kinase (ortholog of human ATM) is activated at DNA double strand breaks (DSBs) and short telomeres. Despite the well-established roles of Tel1 in the control of telomere maintenance, suppression of chromosomal rearrangements, activation of cell cycle checkpoints, and repair of DSBs, the substrates through which Tel1 controls these processes remain incompletely understood. Here we performed an in depth phosphoproteomic screen for Tel1-dependent phosphorylation events. To achieve maximal coverage of the phosphoproteome, we developed a scaled-up approach that accommodates large amounts of protein extracts and chromatographic fractions. Compared to previous reports, we expanded the number of detected Tel1-dependent phosphorylation events by over 10-fold. Surprisingly, in addition to the identification of phosphorylation sites featuring the canonical motif for Tel1 phosphorylation (S/T-Q), the results revealed a novel motif (D/E-S/T) highly prevalent and enriched in the set of Tel1-dependent events. This motif is unique to Tel1 signaling and not shared with the Mec1 kinase, providing clues to how Tel1 plays specialized roles in DNA repair and telomere length control. Overall, these findings define a Tel1-signaling network targeting numerous proteins involved in DNA repair, chromatin regulation, and telomere maintenance that represents a framework for dissecting the molecular mechanisms of Tel1 action.

Biomedical Effects of Protein Arginine Methyltransferase Inhibitors.

Protein arginine methyltransferases (PRMTs) are enzymes that catalyze the methylation of arginine residues in eukaryotic proteins, playing critical roles in modulating diverse cellular processes. The importance of PRMTs in the incidence and progression of a wide range of diseases, particularly cancers, such as breast, liver, lung, colorectal cancer, lymphoma, leukemia, and acute myeloid leukemia (AML) is increasingly recognized. This underscores the critical need for the development of effective PRMT inhibitors as therapeutic intervention. The field of PRMT inhibitors is in the rapidly growing phase and it is necessary to conduct a summative review of how the so-far developed inhibitors impact PRMT functions and cellular physiology. Our review aims to summarize molecular action mechanisms of these PRMT inhibitors and particularly elaborate their triggered biomedical effects. We delineate the cellular phenotype consequences of select PRMT inhibitors across various disease models, thereby providing an understanding of the pharmacological mechanisms underpinning PRMT inhibition. The promising effects of PRMT5 inhibitors in targeted therapy of MTAP-deleted cancers is particularly highlighted. At last, we provide a perspective on the challenges and further opportunities of developing and applying novel PRMT inhibitors for clinical advancement.

A Cross-Species Atlas of the Dorsal Vagal Complex Reveals Neural Mediators of Cagrilintide's Effects on Energy Balance.

Amylin analogs, including potential anti-obesity therapies like cagrilintide, act on neurons in the brainstem dorsal vagal complex (DVC) that express calcitonin receptors (CALCR). These receptors, often combined with receptor activity-modifying proteins (RAMPs), mediate the suppression of food intake and body weight. To understand the molecular and neural mechanisms of cagrilintide action, we used single-nucleus RNA sequencing to define 89 cell populations across the rat, mouse, and non-human primate caudal brainstem. We then integrated spatial profiling to reveal neuron distribution in the rat DVC. Furthermore, we compared the acute and long-term transcriptional responses to cagrilintide across DVC neurons of rats, which exhibit strong cagrilintide responsiveness, and mice, which respond poorly to cagrilintide over the long term. We found that cagrilintide promoted long-term transcriptional changes, including increased prolactin releasing hormone (Prlh) expression, in the nucleus of the solitary tract (NTS) Calcr/Prlh cells in rats, but not in mice, suggesting the importance of NTS Calcr/Prlh cells for sustained weight loss. Indeed, activating rat area postrema Calcr cells briefly reduced food intake but failed to decrease food intake or body weight over the long term. Overall, these results not only provide a cross-species and spatial atlas of DVC cell populations but also define the molecular and neural mediators of acute and long-term cagrilintide action.

Ag85B-Induced M1 Macrophage Polarization via the TLR4/TRAF6/NF-κB Axis Leading to Bronchial Epithelial Cell Damage and TH17/Treg Imbalance.

Antigen 85B (Ag85B) is a signature antigen of Mycobacterium tuberculosis (MTB). In this study, we aimed to investigate the impact of macrophages stimulated with Ag85B on bronchial epithelial cells and T cells, as well as the underlying mechanisms involved. We used Ag85B to stimulate macrophage and investigated the impact of Ag85B on macrophage polarization. We assessed the impact of TLR4 on Ag85Bmediated macrophage polarization by silencing TLR4. Additionally, the regulatory role of TLR4 on the TRAF6/NF-κB pathway was evaluated through immunoblotting. Activated macrophages with Ag85B were co-cultured with bronchial epithelial cells and T cells, respectively. Through immunoblotting quantification, biochemical methods, and flow cytometry, we explored the effects and molecular mechanisms of Ag85B-induced macrophage activation on bronchial epithelial cell damage and T-cell transformation. In macrophages stimulated with Ag85B, levels of M1 polarization-related genes (CXCL9, CXCL10, and iNOS) and cytokines (IL-6, TNF-α, IL-1β, and IL-12) were increased, and the M1/M2 ratio was elevated. TLR4 silence inhibited the effects of Ag85B on macrophages and decreased TRAF6 and p-NF-κB/NF-κB levels. TRAF6 overexpression reversed the inhibitory effect of TLR4 on macrophage stimulation with Ag85B. After co-culturing with macrophages induced by Ag85B, MBEC cell proliferation was inhibited, apoptosis was promoted, and the TH17/Treg ratio of T cells was increased. Silencing TLR4 reversed the impact of Ag85B-induced macrophage polarization on bronchial epithelial cells and T cells, which was further reversed by TRAF6 overexpression. Ag85B promoted M1 polarization in macrophages through the TLR4/TRAF6/NF-κB axis, resulting in bronchial epithelial cell damage and an imbalance in TH17/Treg cells.