Zafirlukast Is a Promising Scaffold for Selectively Inhibiting TNFR1 Signaling

Targeting the inter-monomeric space of TNFR1 pre-ligand dimers: A novel binding pocket for allosteric modulators

Tumor necrosis factor (TNF) receptor 1 (TNFR1) plays a central role in signal transduction mediating inflammation and cell death associated with autoimmune and neurodegenerative disorders. Inhibition of TNFR1 signaling is a highly sought-after strategy to target these diseases. TNFR1 forms pre-ligand dimers held together by the pre-ligand assembly domain (PLAD), which is essential for receptor signaling. TNFR1 dimers form the crucial points of interaction for the entire receptor signaling complex by connecting TNF ligand bound trimeric receptors. While previous studies have shown the feasibility of disrupting TNFR1 dimeric interactions through competitive mechanism that targets the PLAD, our recent studies have demonstrated that small molecules could also bind PLAD to modulate TNFR1 signaling through an allosteric mechanism. Importantly, these allosteric modulators alter receptor dynamics and propagate long-range conformational perturbation that involves reshuffling of the receptors in the cytosolic domains without disrupting receptor-receptor or receptor-ligand interactions. In this study, we perform molecular docking of previously reported allosteric modulators on the extracellular domain of TNFR1 to understand their binding sites and interacting residues. We identify the inter-monomeric space between TNFR1 pre-ligand dimers as a novel binding pocket for allosteric modulators. We further conduct pharmacological analyses to understand the bioactivity of these compounds and their interacting residues and pharmacological properties. We then provide insights into the structure-activity relationship of these allosteric modulators and the feasibility of targeting TNFR1 conformational dynamics. This paves the way for developing new therapeutic strategies and designing chemical scaffolds to target TNFR1 signaling.

Therapeutic targeting of obesity-induced neuroinflammation and neurodegeneration

Obesity is a major modifiable risk factor leading to neuroinflammation and neurodegeneration. Excessive fat storage in obesity promotes the progressive infiltration of immune cells into adipose tissue, resulting in the release of pro-inflammatory factors such as cytokines and adipokines. These inflammatory mediators circulate through the bloodstream, propagating inflammation both in the periphery and in the central nervous system. Gut dysbiosis, which results in a leaky intestinal barrier, exacerbates inflammation and plays a significant role in linking obesity to the pathogenesis of neuroinflammation and neurodegeneration through the gut-brain/gut-brain-liver axis. Inflammatory states within the brain can lead to insulin resistance, mitochondrial dysfunction, autolysosomal dysfunction, and increased oxidative stress. These disruptions impair normal neuronal function and subsequently lead to cognitive decline and motor deficits, similar to the pathologies observed in major neurodegenerative diseases, including Alzheimer's disease, multiple sclerosis, and Parkinson's disease. Understanding the underlying disease mechanisms is crucial for developing therapeutic strategies to address defects in these inflammatory and metabolic pathways. In this review, we summarize and provide insights into different therapeutic strategies, including methods to alter gut dysbiosis, lifestyle changes, dietary supplementation, as well as pharmacological agents derived from natural sources, that target obesity-induced neuroinflammation and neurodegeneration.

Exploring TNFR1: from discovery to targeted therapy development

This review seeks to elucidate the therapeutic potential of tumor necrosis factor receptor 1 (TNFR1) and enhance our comprehension of its role in disease mechanisms. As a critical cell-surface receptor, TNFR1 regulates key signaling pathways, such as nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK), which are associated with pro-inflammatory responses and cell death. The intricate regulatory mechanisms of TNFR1 signaling and its involvement in various diseases, including inflammatory disorders, infectious diseases, cancer, and metabolic syndromes, have attracted increasing scholarly attention. Given the potential risks associated with targeting tumor necrosis factor-alpha (TNF-α), selective inhibition of the TNFR1 signaling pathway has been proposed as a promising strategy to reduce side effects and enhance therapeutic efficacy. This review emphasizes the emerging field of targeted therapies aimed at selectively modulating TNFR1 activity, identifying promising therapeutic strategies that exploit TNFR1 as a drug target through an evaluation of current clinical trials and preclinical studies. In conclusion, this study contributes novel insights into the biological functions of TNFR1 and presents potential therapeutic strategies for clinical application, thereby having substantial scientific and clinical significance.

TNF receptors: Structure-function relationships and therapeutic targeting strategies

Tumor necrosis factor receptors (TNFR1 and TNFR2) play key roles in mediating inflammatory response and cell death signaling, which are associated with autoimmune disorders, neurodegenerative diseases, and cancers. The structure-function relationships of TNF receptors and their ligands determine the activation or inhibition of downstream signaling pathways. Available crystal structures have provided critical insights into the therapeutic targeting strategies of TNF receptors and their signaling networks. In this review, we discuss the potential of targeting receptor-ligand and receptor-receptor interactions in a competitive manner as well as perturbing receptor conformational dynamics through an allosteric mechanism to modulate TNF receptor signaling. We propose that conformational states of TNF receptors can act as a molecular switch in determining their functions and are important therapeutic targets. The knowledge of the structure-function relationships of TNF receptors can be applied to translational high-throughput drug screening and design of novel receptor-specific modulators with enhanced pharmacological properties.

Recent Advances in Marine-Derived Nanoformulation for the Management of Glioblastoma

Glioma is the most common and aggressive type of central nervous system tumor as categorized by the World Health Organization. Glioblastoma (GBA), in general, exhibits a grim prognosis and short life expectancy, rarely exceeding 14 months. The dismal prognosis is primarily attributed to the development of chemoresistance to temozolomide, the primary therapeutic agent for GBA treatment. Hence, it becomes imperative to develop novel drugs with antitumor efficacy rooted in distinct mechanisms compared to temozolomide. The vast marine environment contains a wealth of naturally occurring compounds from the sea (known as marine-derived natural products), which hold promise for future research in the quest for new anticancer drugs. Ongoing advancements in anticancer pharmaceuticals have led to an upswing in the isolation and validation of numerous pioneering breakthroughs and improvements in anticancer therapeutics. Nonetheless, the availability of FDA-approved marine-derived anticancer drugs remains limited, owing to various challenges and constraints. Among these challenges, drug delivery is a prominent hurdle. This review delves into an alternative approach for delivering marine-derived drugs using nanotechnological formulations and their mechanism of action for treating GBA.

Acidic Nanoparticles Restore Lysosomal Acidification and Rescue Metabolic Dysfunction in Pancreatic β-Cells under Lipotoxic Conditions

Type 2 diabetes (T2D), a prevalent metabolic disorder lacking effective treatments, is associated with lysosomal acidification dysfunction, as well as autophagic and mitochondrial impairments. Here, we report a series of biodegradable poly(butylene tetrafluorosuccinate-co-succinate) polyesters, comprising a 1,4-butanediol linker and varying ratios of tetrafluorosuccinic acid (TFSA) and succinic acid as components, to engineer lysosome-acidifying nanoparticles (NPs). The synthesized NPs are spherical with diameters of ≈100 nm and have low polydispersity and good stability. Notably, TFSA NPs, which are composed entirely of TFSA, exhibit the strongest degradation capability and superior acidifying properties. We further reveal significant downregulation of lysosomal vacuolar (H+)-ATPase subunits, which are responsible for maintaining lysosomal acidification, in human T2D pancreatic islets, INS-1 β-cells under chronic lipotoxic conditions, and pancreatic tissues of high-fat-diet (HFD) mice. Treatment with TFSA NPs restores lysosomal acidification, autophagic function, and mitochondrial activity, thereby improving the pancreatic function in INS-1 cells and HFD mice with lipid overload. Importantly, the administration of TFSA NPs to HFD mice reduces insulin resistance and improves glucose clearance. These findings highlight the therapeutic potential of lysosome-acidifying TFSA NPs for T2D.

Peptide-based allosteric inhibitor targets TNFR1 conformationally active region and disables receptor-ligand signaling complex

Tumor necrosis factor (TNF) receptor 1 (TNFR1) plays a pivotal role in mediating TNF induced downstream signaling and regulating inflammatory response. Recent studies have suggested that TNFR1 activation involves conformational rearrangements of preligand assembled receptor dimers and targeting receptor conformational dynamics is a viable strategy to modulate TNFR1 signaling. Here, we used a combination of biophysical, biochemical, and cellular assays, as well as molecular dynamics simulation to show that an anti-inflammatory peptide (FKCRRWQWRMKK), which we termed FKC, inhibits TNFR1 activation allosterically by altering the conformational states of the receptor dimer without blocking receptor-ligand interaction or disrupting receptor dimerization. We also demonstrated the efficacy of FKC by showing that the peptide inhibits TNFR1 signaling in HEK293 cells and attenuates inflammation in mice with intraperitoneal TNF injection. Mechanistically, we found that FKC binds to TNFR1 cysteine-rich domains (CRD2/3) and perturbs the conformational dynamics required for receptor activation. Importantly, FKC increases the frequency in the opening of both CRD2/3 and CRD4 in the receptor dimer, as well as induces a conformational opening in the cytosolic regions of the receptor. This results in an inhibitory conformational state that impedes the recruitment of downstream signaling molecules. Together, these data provide evidence on the feasibility of targeting TNFR1 conformationally active region and open new avenues for receptor-specific inhibition of TNFR1 signaling.