Depressive disorders (DDs), especially treatment-resistant depression (TRD), pose a significant challenge worldwide, largely because their underlying biological mechanisms are complicated and treatmen Show more
Depressive disorders (DDs), especially treatment-resistant depression (TRD), pose a significant challenge worldwide, largely because their underlying biological mechanisms are complicated and treatments often fall short. There is growing evidence pointing to factors like disrupted neuroplasticity, neuroinflammation, irregularities in the hypothalamic-pituitary-adrenal (HPA) axis, and glutamatergic system imbalances as contributors to the onset and persistence of depressive symptoms. Exosomes (small extracellular vesicles involved in communication between cells) have recently gained attention for their potential role in connecting peripheral and central nervous system (CNS) changes. They carry proteins, lipids, and nucleic acids and are even capable of crossing the blood-brain barrier. Because of this, exosomes might provide a window into molecular changes in the brain and serve as accessible biomarkers of disease status and treatment response. Recent research points out that the contents of exosomes, especially microRNAs (miRNAs) and neurotrophic factors like brain-derived neurotrophic factor (BDNF), might play a part in disrupting synaptic plasticity and could be linked to resistance to antidepressants. At the same time, there is growing interest in using engineered exosomes as targeted drug carriers aimed at the CNS. That said, there are still quite a few hurdles to overcome. Methods vary widely between studies, protocols for isolating exosomes are not sufficiently standardized, safety data are limited, and we do not fully understand how drugs and exosomes interact or how they behave pharmacokinetically. This review brings together current findings regarding exosomes in DDs (with particular emphasis on TRD), highlights their promise for diagnosis and treatment, and sets out some of the main questions that need to be answered before clinical application becomes feasible. Show less
Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer mortality in American women. Normal ovarian physiology is intricately connected to small GTP binding proteins of the Ras superfamil Show more
Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer mortality in American women. Normal ovarian physiology is intricately connected to small GTP binding proteins of the Ras superfamily (Ras, Rho, Rab, Arf, and Ran) which govern processes such as signal transduction, cell proliferation, cell motility, and vesicle transport. We hypothesized that common germline variation in genes encoding small GTPases is associated with EOC risk. We investigated 322 variants in 88 small GTPase genes in germline DNA of 18,736 EOC patients and 26,138 controls of European ancestry using a custom genotype array and logistic regression fitting log-additive models. Functional annotation was used to identify biofeatures and expression quantitative trait loci that intersect with risk variants. One variant, ARHGEF10L (Rho guanine nucleotide exchange factor 10 like) rs2256787, was associated with increased endometrioid EOC risk (OR = 1.33, p = 4.46 x 10-6). Other variants of interest included another in ARHGEF10L, rs10788679, which was associated with invasive serous EOC risk (OR = 1.07, p = 0.00026) and two variants in AKAP6 (A-kinase anchoring protein 6) which were associated with risk of invasive EOC (rs1955513, OR = 0.90, p = 0.00033; rs927062, OR = 0.94, p = 0.00059). Functional annotation revealed that the two ARHGEF10L variants were located in super-enhancer regions and that AKAP6 rs927062 was associated with expression of GTPase gene ARHGAP5 (Rho GTPase activating protein 5). Inherited variants in ARHGEF10L and AKAP6, with potential transcriptional regulatory function and association with EOC risk, warrant investigation in independent EOC study populations. Show less