Fonteh, Alfred

Abstract Background Migraine patients show choroid plexus (CP) changes, impairing the blood-CSF barrier. The CP regulates circadian rhythms, but links between CP circadian genes and migraine are unexplored. Objective This study examined CP circadian gene transcriptome changes in a chronic migraine rat model versus controls to identify migraine-related pathways. Design Chronic migraine model: Sprague Dawley rats (3 females, 3 males) received nitroglycerine (NTG) every other day for 9 days; controls (3 females, 3 males) got saline. CP from the 4th ventricle was collected 2 hours post-final injection for RNAseq. Methods Migraine Behavior: Von Frey hair tests on days 1, 5, and 9, pre- and 2 hours post-NTG/saline injection, assessed basal and NTG-induced pain thresholds. RNAseq & Analysis: Differentially expressed genes (p < 0.05, fold change > 1) were identified. GO, KEGG, and Reactome enrichment analyses evaluated circadian gene expression changes. Results NTG group showed reduced basal and NTG-induced pain thresholds on days 1, 5, and 9. Females had more upregulated genes ( MT2A , SLC7A11 ), males upregulated ZBTB16 , S100A8 . SLC7A11 , SCG2 , GRIA1 showed inverse regulation (up in females, down in males). Circadian gene expression altered: 10 genes upregulated (e.g., SERPINE1, MAPK9, ATF4 ), 13 downregulated (e.g., PER2, DBP, EZH2 ). Sex-specific differences: females ( FBXL12, GPR157 ), males ( NKX2-1, ATF4, CLOCK ). GO/KEGG analyses revealed significant enrichment of circadian rhythm-related pathways, insulin resistance, and inflammatory response processes, with sex-specific differences: females showed HIF-1 signaling and hemoglobin-related pathways, while males exhibited arachidonic acid and leukotriene production. Conclusion CP transcriptomics in the rat migraine model revealed sex-specific gene regulation, with females upregulating antioxidant genes (MT2A, SLC7A11) and males upregulating inflammatory factors (ZBTB16, S100A8), alongside circadian disruption (e.g., SERPINE1 upregulated, PER2 downregulated). Pathway analyses indicate enriched circadian rhythms, HIF-1 signaling (females), inflammatory processes (males), lipid metabolism (PPARα), and heme signaling, highlighting sex-specific and circadian targets for migraine therapy.

Abstract Increasing evidence suggests that the subcellular and glycerolipid localization of esterified arachidonic acid (AA) is a key factor in regulating its availability to lipases. The goal of the current study was to determine the potential of AA stored in triglycerides (TG) to serve as a substrate for lipases and 5-lipoxygenase during neutrophil (polymorphonuclear leukocytes, PMN) activation. PMN containing high concentrations of AA in TG were generated by culturing PMN in vitro with high concentrations of exogenous AA (eAA) for 12 h. Cellular AA increased 2- and 4-fold in PMNs incubated with 5 and 20 μM AA, respectively, and this increase was almost exclusively observed in neutral lipids (NL). Further analysis revealed that 88% of the AA in the NL fraction was associated with TG. Subsequent experiments were designed to determine whether this AA in TG could be mobilized and metabolized to eicosanoids during cell activation. TG pools of AA were increased as previously described and then PMN were stimulated with ionophore, A23187. In contrast to the 43-fold increase in TG AA after eAA loading (20 μM), free AA increased by only 1.9-fold after cell stimulation. Similarly, leukotriene (LT)B4 production increased only 2-fold after loading TG with large quantities of AA. The magnitude of increase in free AA released and in LTB4 formation was similar to the magnitude of increase in AA mass in phospholipase (PL), suggesting that PL, and not TG, served as the source of released AA and subsequent product generation. To confirm that AA in TG did not serve as a source for eicosanoid production, cellular pools of AA were differentially labeled with [14C]AA and [3H]AA, and the [3H]AA–to–[14C]AA ratio of LTB4 and 20-hydroxyl LTB4 produced during cell stimulation was measured. The [3H]AA/[14C]AA ratios of LTs were markedly different from the ratios in TG, thus providing further evidence that AA pools in TG are not a major source of AA for LT generation.