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Weljie, A.

Publications and source records attributed to Weljie, A..

8 recordsLinked to original sources

Peripheral Metabolic Reprogramming Links TDP-43 Proteinopathy to Sleep Disruption

Sleep disruption is an early and prevalent feature of neurodegenerative disease, commonly attributed to neuronal circuit dysfunction or cell loss. However, sleep is tightly coupled to metabolic state, raising the possibility that systemic metabolic abnormalities contribute to disease-associated sleep phenotypes. Using Drosophila models of TDP-43 proteinopathy, we investigated whether peripheral metabolic dysfunction plays a causal role in sleep disruption. We show that TDP-43 expression induces a chronic, starvation-like metabolic state characterized by depletion of peripheral carbohydrate stores despite normal feeding. Restoration of sleep fails to correct these metabolic defects, whereas improving peripheral metabolic state robustly rescues sleep. A modifier screen of [~]650 RNAi lines identified Salt-inducible kinase 3 (SIK3) as a potent suppressor of both sleep loss and starvation sensitivity. Transcriptomic and spatial metabolomic analyses reveal that SIK3 selectively remodels a peripheral metabolic program centered on the pentose phosphate pathway and redox-associated metabolites without globally restoring energy stores. Together, these findings identify systemic metabolic dysfunction as a key driver of sleep disruption in TDP-43 proteinopathy and highlight peripheral metabolism as a potential therapeutic entry point for sleep dysfunction in neurodegenerative disease.

neuroscience↗

Integrated Respirometry and Metabolomics Unveil Circadian Metabolic Dynamics in Drosophila

Sleep and circadian rhythms shape organismal energy patterns, but how this timing connects to oxygen use and carbon dioxide production remains incompletely understood. We combined high-resolution respirometry with LC-MS-based metabolomics to characterize respiratory dynamics and metabolic states in Drosophila melanogaster, resolving genotype-specific impacts of sleep disruption and circadian regulation. Wild-type flies under light-dark cycles (WT-LD) showed rhythmic respiratory patterns reflective of anticipatory coordination of mitochondrial energy metabolism, amino acid turnover, and redox cycling. Short-sleep mutants (fmn, sss) exhibited elevated metabolic rates with reactive shifts of fuel preferences toward lipid and amino acid catabolism and altered mitochondrial respiration. The clock-mutant (per01) and flies under constant darkness (WT-DD) showed reactive and widespread metabolic dysregulation and impaired redox homeostasis. These findings demonstrate that both sleep and circadian systems contribute to aligning metabolic substrate selection with energy demands, offering mechanistic insights into how disruptions in behavioral states compromise metabolic health.

biochemistry↗

Metabolomic Response to Non-Steroidal Anti-Inflammatory Drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are popular choices for the mitigation of pain and inflammation; however, they are accompanied by side effects in the gastrointestinal and cardiovascular systems. We compared the effects of naproxen, a traditional NSAID, and celecoxib, a cyclooxygenase -2 (Cox-2) inhibitor, in humans. Our findings showed a decrease in tryptophan and kynurenine levels in plasma of volunteers treated with naproxen. We further validated this result in mice. Additionally, we find that the depression of tryptophan was independent of both Cox-1 and Cox-2 inhibition, but rather was due to the displacement of bound tryptophan by naproxen. Supplementation of tryptophan in naproxen-treated mice rescued fecal blood loss and inflammatory gene expression driven by IL-1{beta} in the heart.

systems biology↗

Concomitant suppression of COX-1 and COX-2 is insufficient to induce enteropathy associated with chronic NSAID use

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely used medications for the management of chronic pain; however, they are associated with numerous gastrointestinal (GI) adverse events. Although many mechanisms have been suggested, NSAID-induced enteropathy has been thought to be primarily due to inhibition of both cyclooxygenases (COX) -1 and -2, which results in suppression of prostaglandin synthesis. Yet surprisingly, we found that concomitant postnatal deletion of Cox-1 and -2 over 10 months failed to cause intestinal injury in mice unless they were treated with naproxen or its structural analog, phenylpropionic acid, which is not a COX inhibitor. Cox double knockout mice exhibit a distinct gut microbiome composition and cohousing them with controls rescues their dysbiosis and delays the onset of NSAID-induced GI bleeding. In both the UK Biobank and All of Us human cohorts, coadministration of antibiotics with NSAIDs is associated with an increased frequency of GI bleeding. These results show that prostaglandin suppression plays a trivial role in NSAID-induced enteropathy. However, Cox deletion causes dysbiosis of the gut microbiome that amplifies the enteropathic response to NSAIDs.

pharmacology and toxicology↗

Brown adipose tissue thermogenesis rhythms are driven by the SCN independent of adipocyte clocks

Circadian misalignment has been associated with obesity both in rodents and humans. Brown adipose tissue (BAT) thermogenesis contributes to energy expenditure and can be activated in adults to reduce body weight. Although previous studies suggest control of BAT thermogenesis by the circadian clock, the site and mechanisms of regulation remain unclear. We used mice with genetic disruption of the circadian clock in the suprachiasmatic nucleus (SCN) and peripheral tissues to delineate their role in BAT thermogenesis. Global post-natal deletion of Bmal1 in adult mice (Bmal1-/-) abolishes the rhythms of interscapular BAT temperature, a measure of thermogenesis, while normal locomotor activity rhythms are maintained under a regular 12h light-12h dark schedule. Activation of thermogenesis either by exposure to cold or adrenergic stimulation of BAT displays a diurnal rhythm with higher activation during the active period. Both the rhythm and the magnitude of the thermogenic response is preserved in Bmal1-/- mice. In contrast to mice with global deletion of Bmal1, mice with brown adipocyte (Ucp1-Bmal1-/-) or brown and white adipocyte (Ad-Bmal1-/-) deletion of Bmal1 show intact rhythms of BAT thermogenic activity. The capacity of Ucp1-Bmal1-/- mice to activate thermogenesis in response to exposure to cold is identical to WT mice, independent of time of stimulation. Circadian rhythmicity of interscapular BAT temperature is lost in mice with SCN deletion of Bmal1 (SCN-Bmal1-/-), indicating control of BAT thermogenesis rhythms by the SCN. Control mice exhibit rhythmic BAT glucose and fatty acid uptake - a rhythm that is not recapitulated in Bmal1-/- and SCN-Bmal1-/- mice but is present in Ucp1-Bmal1-/- and Ad-Bmal1-/- mice. BAT cAMP and phosphorylated hormone-sensitive lipase (pHSL) is reduced during the active period in Bmal1-/- and SCN-Bmal1-/- mice consistent with reduced sympathetic tone. Furthermore, sympathetic denervation of BAT ablates BAT temperature rhythms in WT mice. Taken together, our findings suggest that the SCN drives rhythms of BAT thermogenesis through adipocyte clock-independent, sympathetic signaling to the BAT.

physiology↗

Deep Phenotyping of the Lipidomic Response in COVID and non-COVID Sepsis

Lipids may influence cellular penetrance by pathogens and the immune response that they evoke. Here we find a broad based lipidomic storm driven predominantly by secretory (s) phospholipase A2 (sPLA2) dependent eicosanoid production occurs in patients with sepsis of viral and bacterial origin and relates to disease severity in COVID-19. Elevations in the cyclooxygenase (COX) products of arachidonic acid (AA), PGD2 and PGI2, and the AA lipoxygenase (LOX) product, 12-HETE, and a reduction in the high abundance lipids, ChoE 18:3, LPC-O-16:0 and PC-O-30:0 exhibit relative specificity for COVID-19 amongst such patients, correlate with the inflammatory response and link to disease severity. Linoleic acid (LA) binds directly to SARS-CoV-2 and both LA and its di-HOME products reflect disease severity in COVID-19. AA and LA metabolites and LPC-O-16:0 linked variably to the immune response. These studies yield prognostic biomarkers and therapeutic targets for patients with sepsis, including COVID-19. An interactive purpose built interactive network analysis tool was developed, allowing the community to interrogate connections across these multiomic data and generate novel hypotheses.

systems biology↗

Polyamine elevation and nitrogen stress are toxic hallmarks of chronic sleep loss in Drosophila melanogaster

Chronic sleep loss profoundly impacts health in ways coupled to metabolism; however, much existing literature links sleep and metabolism only on acute timescales. To explore the impact of chronically reduced sleep, we conducted unbiased metabolomics on heads from three Drosophila short-sleeping mutants. Common features included elevated ornithine and polyamines; and lipid, acyl-carnitine, and TCA cycle changes suggesting mitochondrial dysfunction. Biochemical studies of overall, circulating, and excreted nitrogen in sleep mutants demonstrate a specific defect in eliminating nitrogen, suggesting that elevated polyamines may function as a nitrogen sink. Both supplementing polyamines and inhibiting their synthesis with RNAi regulated sleep in control flies. Finally, both polyamine-supplemented food and high-protein feeding were highly toxic to sleep mutants, suggesting their altered nitrogen metabolism is maladaptive. Together, our results suggest polyamine accumulation specifically, and nitrogen stress in general, as potential mechanisms linking chronic sleep loss to adverse health outcomes.

neuroscience↗

CRY1-CBS binding regulates circadian clock function and metabolism

Circadian disruption influences metabolic health. Metabolism modulates circadian function. However, the mechanisms coupling circadian rhythms and metabolism remain poorly understood. Here we report that Cystathionine {beta}-synthase (CBS), a central enzyme in one-carbon metabolism, functionally interacts with the core circadian protein Cryptochrome1 (CRY1). In cells, CBS augments CRY1 mediated repression of the CLOCK/BMAL1 complex and shortens circadian period. Notably, we find that mutant CBS-I278T protein, the most common cause of homocystinuria, does not bind CRY1 or regulate its repressor activity. Transgenic CbsZn/Zn mice, while maintaining circadian locomotor activity period, exhibit reduced circadian power and increased expression of E-BOX outputs. CBS function is reciprocally influenced by CRY1 binding. CRY1 modulates enzymatic activity of the CBS. Liver extracts from Cry1-/- mice show reduced CBS activity that normalizes after the addition of exogenous wild type (WT) CRY1. Metabolomic analysis of WT, CbsZn/Zn, Cry1-/-, and Cry2-/- samples highlights the metabolic importance of endogenous CRY1. We observed temporal variation in one-carbon and transsulfuration pathways attributable to CRY1 induced CBS activation. CBS-CRY1 binding provides a post-translational switch to modulate cellular circadian physiology and metabolic control.

molecular biology↗