Biology subjects

Duraisamy, S.

Publications and source records attributed to Duraisamy, S..

3 recordsLinked to original sources

bioRxiv2026

Evaluating the Sensitivity of Dry and Gel-Based Wearable EEG for Cognitive Load Estimation

PurposeWe present a large-scale (N=120) comparative study of gel-based and dry electroencephalography systems for cognitive load analysis in tasks involving information visualization stimuli. Although dry systems are increasingly adopted owing to their portability and fast setup, their sensitivity to cognitive-related measurements (as compared to gel-based systems) remains debated. This limits the understanding of whether dry systems provide sufficient sensitivity for cognitive load assessment under controlled task conditions. MethodsWe analyzed a diverse set of signal quality metrics, such as signal-to-noise ratio and channel retention, combined with spectral features across frequency bands to evaluate the ability for each device to capture workload-related neural markers during information visualization tasks. ResultsAlthough the gel-based device showed consistently better quality results than the dry one, the effect sizes suggest a small practical significance of the differences between systems. These results demonstrate that dry systems can provide adequate physiological sensitivity for cognitive load assessments. ConclusionOur findings highlight the trade-off between usability (setup, calibration, etc.) and data fidelity, providing practical guidance for choosing electroencephalography systems for cognitive workload monitoring and applied neuroengineering research. Overall, the results suggest that dry systems can support coarse-grained cognitive load assessment, while gel-based systems remain advantageous when greater sensitivity is required.

neuroscience↗

bioRxiv2025

Acute activation of Gq-signaling in islet macrophages inhibits β-cell insulin secretion through AMPK-sphingolipid axis

Obesity-associated inflammation disrupts pancreatic {beta}-cell function, but the immune-derived signals that directly regulate insulin secretion remain incompletely defined. Here, we identify myeloid Gq signaling as a critical immunometabolic node that links macrophage activation to {beta}-cell dysfunction. For the first time, we employed a chemogenetic approach (DREADDs) to selectively and temporally activate Gq-coupled GPCR signaling in myeloid cells to examine its effect on islet function. Our findings reveal that acute Gq activation in islet-resident macrophages impaired glucose-stimulated insulin secretion, uncovering a previously unrecognized immune-endocrine axis. Conversely, myeloid-specific Gq deletion improves systemic glucose homeostasis, underscoring the physiological relevance of this pathway. Mechanistic analysis revealed that Gq activation in macrophages stimulates AMPK signaling and drives the secretion of sphingolipids. These lipids suppress insulin secretion and introduce a new mechanism for immune-islet communication, extending beyond traditional cytokine-based models. We further identify the lipid-sensing receptor GPR18 as an upstream activator of the Gq-AMPK pathway in macrophages. GPR18 stimulation recapitulated the Gq-dependent sphingolipid secretion and {beta}-cell inhibitory phenotype, which was abolished in myeloid Gq-deficient mice. Collectively, these findings establish a mechanistic framework whereby macrophage Gq signaling integrates lipid sensing and metabolic stress to modulate {beta}-cell function. This work reveals a previously unrecognized macrophage-{beta}-cell communication axis with therapeutic potential for restoring insulin secretion in metabolic diseases such as obesity and type 2 diabetes. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/680858v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@790c4dorg.highwire.dtl.DTLVardef@116cceborg.highwire.dtl.DTLVardef@1e76631org.highwire.dtl.DTLVardef@e65770_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2025

Small molecule promoters of endogenous lipid droplet accumulation drive lysophagy

Lipid droplets (LDs) play a central role in regulating metabolism in stress-induced conditions, including one triggered by nutrient deprivation. Unravelling the protein networks involved in the biogenesis of LDs and their causative and functional roles in health and disease continue to evolve. To this cause, genetic manipulation of the lipid metabolic network or supplementation of high fat diet/ oleic acid (OA) are the traditional routes for voluntarily triggering LDs formation in cells and animals. We developed a screening platform for the identification of new LDs inducers, and our primary screening of various fatty acids identified linoleic acid (LOA, DUFA) as a better tool than OA (MUFA) in promoting LDs formation. The screening and validation discovered new small molecule-based tools for promoting a rapid organization of endogenous lipids into droplets in multiple cell types. Notably, our mass spectral lipidomics analysis presented the overproduction of phosphatidylcholines and small triglycerides, a hallmark of LDs. Mechanistic investigations of our lead molecules highlighted lipid peroxidation and ATP depletion through mitochondrial impairment in cells, which could serve as chemical cues for driving the fusion of cellular lipids into LDs. Finally, we uncovered the abrupt levels of LDs formation induced by our molecules promoted lysophagy in cancer cells to prevent their proliferation. Collectively, our work introduces new small molecules as powerful tools for reliably promoting LDs accumulation for studying their roles in biology, and we demonstrate the over accumulation of LDs prevent cancer cell proliferation, movement, and colonization.

cancer biology↗