Fatty acid binding protein 7 (FABP7) is a multifunctional chaperone involved in lipid metabolism and signaling. It is primarily expressed in astrocytes and neural stem cells (NSCs), as well as their derived malignant glioma cells within the central nervous system. Despite growing evidence for FABP7’s tumor-intrinsic onco-metabolic functions, its mechanistic role in regulating the brain tumor immune microenvironment (TIME) and its impact on prognosis at the molecular level remain incompletely understood. Utilizing combined transcriptome profiling and pan-cancer analysis approaches, we report that FABP7 mediates the expression of multiple onco-immune drivers, collectively impacting tumor immunity and clinical outcomes across brain cancer subtypes. An analysis of a single-cell expression atlas revealed that FABP7 is predominantly expressed in the glial lineage and malignant cell populations in gliomas, with nuclear localization in their parental NSCs. Pathway and gene enrichment analysis of RNA sequencing data from wild-type (WT) and Fabp7-knockout (KO) mouse brains, alongside control (CTL) and FABP7-overexpressing (FABP7 OV) human astrocytes, revealed a more pronounced effect of FABP7 levels on multiple cancer-associated pathways. Notably, genes linked to brain cancer progression and tumor immunity (ENO1, MUC1, COL5A1, and IL11) were significantly downregulated (>2-fold) in KO brain tissue but were upregulated in FABP7 OV astrocytes. Furthermore, an analysis of data from The Cancer Genome Atlas (TCGA) showed robust correlations between the expression of these factors, as well as FABP7, and established glioma oncogenes (EGFR, BRAF, NF1, PDGFRA, IDH1), with stronger associations seen in low-grade glioma (LGG) than in glioblastoma (GBM). TIME profiling also revealed that the expression of FABP7 and the genes that it modulates was significantly associated with prognosis and survival, particularly in LGG patients, by influencing the infiltration of immunosuppressive cell populations within tumors. Overall, our findings suggest that FABP7 acts as an intracellular regulator of pro-tumor immunomodulatory genes, exerting a synergistic effect on the TIME and clinical outcomes in brain cancer subtypes.

Humans with post-traumatic stress disorder (PTSD) exhibit sleep disturbances that include insomnia, nightmares, and enhanced daytime sleepiness. Sleep disturbances are considered a hallmark feature of PTSD; however, little is known about the cellular and molecular mechanisms regulating trauma-induced sleep disorders. Using a rodent model of PTSD called “Single Prolonged Stress” (SPS) we examined the requirement of the brain-type fatty acid binding protein Fabp7, an astrocyte expressed lipid-signaling molecule, in mediating trauma-induced sleep disturbances. We measured baseline sleep/wake parameters and then exposed Fabp7 knock-out (KO) and wild-type (WT) C57BL/6N genetic background control animals to SPS. Sleep and wake measurements were obtained immediately following the initial trauma exposure of SPS, and again 7 days later. We found that active-phase (dark period) wakefulness was similar in KO and WT at baseline and immediately following SPS; however, it was significantly increased after 7 days. These effects were opposite in the inactive-phase (light period), where KOs exhibited increased wake in baseline and following SPS, but returned to WT levels after 7 days. To examine the effects of Fabp7 on unconditioned anxiety following trauma, we exposed KO and WT mice to the light–dark box test before and after SPS. Prior to SPS, KO and WT mice spent similar amounts of time in the lit compartment. Following SPS, KO mice spent significantly more time in the lit compartment compared to WT mice. These results demonstrate that mutations in an astrocyte-expressed gene (Fabp7) influence changes in stress-dependent sleep disturbances and associated anxiety behavior.

Parkinson’s Disease (PD) is the most common movement disorder, and the strongest genetic risk factor for PD is mutations in the glucocerebrosidase gene (GBA). Mutations in GBA also lead to the development of Gaucher Disease (GD), the most common type of lysosomal storage disorder. Current therapeutic approaches fail to address neurological GD symptoms. Therefore, identifying therapeutic strategies that improve the phenotypic traits associated with GD/PD in animal models may provide an opportunity for treating neurological manifestations of GD/PD. Thiazolidinediones (TZDs, also called glitazones) are a class of compounds targeted for the treatment of type 2 diabetes, and have also shown promise for the treatment of neurodegenerative disease, including PD. Here, we tested the efficacy of glitazone administration during development in a fly GD model with deletions in the GBA homolog, dGBA1b (GBA1^ΔTT/ΔTT). We observed an optimal dose of pioglitazone (PGZ) at a concentration of 1 μM that reduced sleep deficits, locomotor impairments, climbing defects, and restoration of normal protein levels of Ref(2)P, a marker of autophagic flux, in GBA1^ΔTT/ΔTT mutant flies, compared to GBA1^+/+ control flies. These data suggest that PGZ may represent a potential compound with which to treat GD/PD by improving function of lysosomal-autophagy pathways, a cellular process that removes misfolded or aggregated proteins.

Alzheimer’s disease (AD) is a complex neurodegenerative disorder where age, genetic factors and sleep disturbance significantly influence disease risk. Recent genome-wide association studies identified a C/T missense variant (rs141749679) in the sortilin (SORT1) gene linked to heightened AD risk, revealing SORT1’s role as a key player in the disease’s pathophysiology. This type I membrane glycoprotein is implicated in amyloid β (Aβ) accumulation and associated lipid dysregulation, particularly through its interaction with apolipoprotein E (ApoE). SORT1 facilitates the uptake of ApoE-bound polyunsaturated fatty acids (PUFAs), conversion to endocannabinoids (eCBs), and the regulation of anti-inflammatory pathways via peroxisome proliferator-activated receptors (PPARs). Notably, this neuroprotective signaling is contingent on the APOE allele, exhibiting functionality in presence of ApoE3 but disrupted with ApoE4. Additionally, the brain-type fatty acid binding protein, FABP7, mediates this signaling cascade, emphasizing its role in neuron-glia communication. FABP7 is known to regulate sleep across species and binds PUFAs and eCBs. Therefore, dysfunction of the ApoE-SORT1-FABP7 axis may underlie the neuroprotective loss observed in AD, linking sleep disruption and lipid homeostasis to disease progression. This perspective aims to elucidate the intricate neural-glial mechanisms governing the ApoE-SORT1-FABP7 interaction and their implications for targeting therapeutic interventions in Alzheimer’s disease.

Epileptic seizures often track with time of day and/or changes in vigilance state; however, specific molecular and cellular mechanisms driving the ictal and temporal associations are lacking. Astrocytes are a type of glial cell known to modulate neuronal excitability and circadian rhythms. These cells also abundantly express fatty acid–binding protein 7 (Fabp7), a clock-driven molecule necessary for normal sleep regulation, lipid signaling, and gene transcription. To determine whether Fabp7 influences time-of-day-dependent seizure susceptibility, we tested male C57/BL6N wild-type (WT) and Fabp7 knockout (KO) mice using electroshock seizure threshold. Compared with WT mice, Fabp7 KO mice exhibited markedly higher general- and maximal-electroshock seizure thresholds (GESTs and MESTs, respectively) during the dark phase, but not the light phase. We used RNA-seq to determine the role of Fabp7 in activity-dependent gene expression in nocturnal seizures and compared genome-wide mRNA expression in cortical/hippocampal tissue collected from WT-MEST and Fabp7 KO-MEST mice with WT-SHAM and Fabp7 KO-SHAM mice during the dark period. Whereas significant differential expression of immediate early genes was observed in WT-MEST compared with WT-SHAM, this effect was blocked in the Fabp7 KO-MEST versus Fabp7 KO-SHAM. Gene ontology and pathway analysis of all groups revealed significant overlap between WT-MEST:WT-SHAM and Fabp7 KO-SHAM:WT-SHAM comparisons, suggesting basal mRNA levels of core molecular and cellular mechanisms in the brain of Fabp7 KO approximate postictal WT brain. Together, these data suggest that Fabp7 regulates time-of-day-dependent neural excitability and that neural activity likely interacts with astrocyte Fabp7-mediated signaling cascades to influence activity-dependent gene expression.

Background/Objectives: Patients with epilepsy commonly experience patterns of seizures that change with sleep/wake behavior or diurnal rhythms. The cellular and molecular mechanisms that underlie these patterns in seizure activity are not well understood but may involve non-neuronal cells, such as astrocytes. Our previous studies show the critical importance of one specific astrocyte factor, the brain-type fatty acid binding protein Fabp7, in the regulation of time-of-day-dependent electroshock seizure threshold and neural activity-dependent gene expression in mice. Here, we examined whether Fabp7 influences differential seizure activity-dependent protein expression, by comparing Fabp7 knockout (KO) to wild-type (WT) mice under control conditions and after reaching the maximal electroshock seizure threshold (MEST). Methods: We analyzed the proteome in cortical–hippocampal extracts from MEST and SHAM groups of WT and KO mice using mass spectrometry (MS), followed by Gene Ontology (GO) and pathway analyses. GO and pathway analyses of all groups revealed a diverse set of up- and downregulated differentially expressed proteins (DEPs). Results: We identified 65 significant DEPs in the comparison of KO SHAM versus WT SHAM; 33 proteins were upregulated and 32 were downregulated. We found downregulation in mitochondrial-associated proteins in WT MEST compared to WT SHAM controls, including Slc1a4, Slc25a27, Cox7a2, Cox8a, Micos10, and Atp5mk. Several upregulated DEPs in the KO SHAM versus WT SHAM comparison were associated with the 20S proteasomal subunit, suggesting proteasomal activity is elevated in the absence of Fabp7 expression. We also observed 92 DEPs significantly altered in the KO MEST versus WT MEST, with 49 proteins upregulated and 43 downregulated. Conclusions: Together, these data suggest that the astrocyte Fabp7 regulation of time-of-day-mediated neural excitability is modulated by multiple cellular mechanisms, which include proteasomal pathways, independent of its role in activity-dependent gene expression.