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Manickam, V.

Publications and source records attributed to Manickam, V..

2 recordsLinked to original sources

Resolving early cochlear inflammation prevents lasting damage from noise exposure

Noise-induced hearing loss (NIHL) is a leading cause of permanent hearing impairment worldwide, yet no pharmacological therapies are currently available to prevent or treat this disorder. Although inflammation is increasingly recognized as a key contributor to cochlear degeneration, the therapeutic potential of targeting early inflammatory signaling remains poorly understood. Here, we combined phenotypic screening in zebrafish with mechanistic and functional validation in complementary mouse models to identify quinoxaline derivatives with otoprotective activity following acoustic trauma. Lead compounds preserved cochlear synapses and auditory function after moderate noise exposure, while one derivative also protected sensory hair cells in a model of permanent hearing loss. Mechanistic analyses demonstrated that this protection was associated with attenuation of early NF-{kappa}B signaling and modulation of the cochlear inflammatory response toward a reparative state, consistent with suppression of pathogenic innate immune activation before irreversible tissue damage occurred. Together, these findings identify early NF-{kappa}B-dependent inflammatory signaling as a therapeutically actionable mechanism in NIHL and establish quinoxaline derivatives as promising candidates for pharmacological intervention. More broadly, this work demonstrates the utility of a cross-species discovery platform for identifying therapies that preserve sensory function by targeting early inflammatory pathways.

neuroscience↗

Hypercholesterolemia Impairs Clearance of Extracellular DNA and Promotes Inflammation and Atherosclerotic Plaque Progression

Defects in clearance of extracellular DNA due to sub-optimal activity of DNase results in exacerbated inflammation and contributes to the pathophysiology of atherosclerosis and other inflammatory diseases. However, the physiological mechanisms that regulate systemic DNase levels and the basis of its functional impairment during disease are poorly understood. Using a mouse model of experimental increase in systemic extracellular DNA levels, we identify the existence of a physiologic DNA-induced DNase response. Importantly, hypercholesterolemia in mice impairs this critical DNA-induced DNase response through an endoplasmic reticulum stress-mediated mechanism with consequences in advanced atherosclerotic plaque progression including increased extracellular DNA accumulation, exacerbated inflammation, and development of pathological features of necrotic rupture-prone vulnerable plaques. From a translational standpoint in humans, we demonstrate that individuals with hypercholesterolemia have elevated systemic extracellular DNA levels and decreased plasma DNase activity. These data suggest that the restoration of DNA-induced DNase response could be a potential therapeutic strategy to promote inflammation resolution during hypercholesterolemia.

immunology↗