NLRP3 inflammasome in neuroinflammation and central nervous system diseases

Inhibition of α-synuclein aggregation by MCC950 attenuates dopaminergic neuronal damage in MN9D cells

Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons and the pathological aggregation of α-synuclein, which drives neurodegeneration. The NLRP3 inflammasome inhibitor MCC950 has shown neuroprotective effects in various PD models, but its direct impact on α-synuclein aggregation remains unclear. Here, we investigated the effects of MCC950 in an α-synuclein-overexpressing MN9D dopaminergic neuronal model. MCC950 significantly alleviated α-synuclein-induced neuronal damage, as evidenced by improved cell viability, reduced apoptosis, and downregulated tumor necrosis factor-alpha (TNF-α) expression. Proteomic analysis revealed that MCC950 modulates protein processing in the endoplasmic reticulum (ER), potentially alleviating stress-induced protein misfolding. Molecular docking and biochemical assays demonstrated that MCC950 directly binds to the C-terminal region of α-synuclein, inhibiting its aggregation. Additionally, MCC950 upregulated heat shock protein 70 (HSP70), a molecular chaperone that suppresses α-synuclein oligomerization. Notably, the neuroprotective effects of MCC950 were independent of autophagy modulation or NLRP3 inflammasome inhibition in this model. These findings highlight MCC950 as a multi-target therapeutic agent that directly inhibits α-synuclein aggregation, offering a promising strategy for treating PD and related α-synucleinopathies.

Alzheimer's Disease: A Review of Molecular Mechanisms and Therapeutic Implications by Targeting Sirtuins, Caspases, and GSK-3

Alzheimer's disease (AD) is a neurodegenerative disease with a significant impact on global public health. The primary hallmarks of the disease included amyloid-beta peptide (Aβ) deposition, neurofibrillary tangles (NFT), and synaptic loss. Sirtuins, a group of NAD+-dependent deacetylase enzymes, are key regulators of AD pathogenesis. SIRT1, a member of sirtuins, has been identified to possess neuroprotective properties. Thus, its promising enhancers are included. Further, SIRT2 promising inhibitors are reviewed for therapeutic efficacy. The extrinsic and intrinsic apoptotic pathways of caspases are mediated by CD95 and DNA damage. The promising inhibitors Q-VD-OPh and minocycline are found to be specific for caspase-7 and caspase-3, respectively. Primarily, glycogen synthase kinase-3β (GSK-3β) is found to be involved in the generation of phosphorylated tau. The promising GSK-3 inhibitor included the COB-187 (IC50 = 370 nM) and maleimide-derivative (compound 33, IC50 = 0.09 μM). This review highlights the molecular mechanisms of sirtuin, caspase, and GSK-3 in the pathophysiology of AD. Further, promising modulators specific to these targets are described.

Targeting Hyperuricemia and NLRP3 Inflammasome in Gouty Arthritis: A Preclinical Evaluation of Allopurinol and Disulfiram Combination Therapy

Background/Objectives: Gouty arthritis (GA) is a chronic inflammatory condition characterized by hyperuricemia and NLRP3 inflammasome activation, leading to joint damage and systemic inflammation. Although allopurinol (ALP), a xanthine oxidase inhibitor, effectively lowers serum urate levels, it has limited anti-inflammatory effects. This study investigated whether combining disulfiram (DSF), a known NLRP3 inflammasome inhibitor, with ALP enhances therapeutic outcomes in a rat model of gout. Methods: Thirty male Albino Wistar rats (150-200 g) were randomly assigned to five groups (n = 6): control, disease control, ALP-treated, DSF-treated, and ALP + DSF combination. Hyperuricemia was induced using potassium oxonate, followed by MSU crystal injection to trigger acute gout. Treatment lasted 30 days. Efficacy was assessed through clinical scoring, paw swelling, serum uric acid levels, ELISA-based cytokine profiling (IL-1β, TNF-α, IL-6), renal function tests, radiography, and histopathology. Results: Combination therapy with ALP + DSF significantly reduced paw swelling (p < 0.05), inflammation index (p < 0.001), serum uric acid (p < 0.001), and pro-inflammatory cytokines compared to monotherapy. Histopathology revealed preserved synovial architecture and reduced inflammatory infiltration. Radiographic imaging showed attenuated soft tissue swelling and joint erosion. Renal function markers were also improved in the combination group. Conclusions: The combination of ALP and DSF provided superior anti-inflammatory and urate-lowering effects compared to individual treatments. These findings support the potential of disulfiram as an adjunct to conventional ULTs in gout management through dual modulation of urate metabolism and inflammasome-driven inflammation.

NLRP3 inflammasome: From drug target to drug discovery

The immune system employs innate and adaptive immunity to combat pathogens and stress stimuli. Innate immunity rapidly detects pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) via pattern recognition receptors (PRRs), whereas adaptive immunity mediates antigen-specific T/B cell responses. The NLRP3 inflammasome, a key cytoplasmic PRR, consists of leucine-rich repeat, nucleotide-binding, and pyrin domains. Its activation requires priming (signal 1: Toll-like receptors/NOD-like receptors/cytokine receptors) and activation (signal 2: PAMPs/DAMPs/particulates). NLRP3 triggers cytokine storms and neuroinflammation, contributing to inflammatory diseases. Emerging therapies target NLRP3 via nuclear receptors (transcriptional regulation), adeno-associated virus (AAV) vectors (gene delivery), and microRNAs (post-transcriptional modulation). This review highlights NLRP3's signaling cascade, pathological roles, and combinatorial treatments leveraging nuclear receptors, AAVs, and microRNAs for immunomodulation.

Role and Functions of Irisin: A Perspective on Recent Developments and Neurodegenerative Diseases

Irisin is a peptide derived from fibronectin type III domain-containing protein 5 (FNDC5) and is primarily produced by muscle fibers under the regulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) during exercise. Irisin has been the subject of extensive research due to its potential as a metabolic regulator and its antioxidant properties. Notably, it has been associated with protective actions within the brain. Despite growing interest, many questions remain regarding the molecular mechanisms underlying its effects. This review summarizes recent findings on irisin, highlighting its pleiotropic functions and the biological processes and molecular cascades involved in its action, with a particular focus on the central nervous system. Irisin plays a crucial role in neuron survival, differentiation, growth, and development, while also promoting mitochondrial homeostasis, regulating apoptosis, and facilitating autophagy-processes essential for normal neuronal function. Emerging evidence suggests that irisin may improve conditions associated with non-communicable neurological diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, and multiple sclerosis. Given its diverse benefits, irisin holds promise as a novel therapeutic agent for preventing and treating neurological diseases.