The chemokine CXCL1 and its receptor CXCR2 contribute to chronic stress-induced depression in mice.

Depression is increasingly recognized as an inflammatory disease, with inflammatory crosstalk in the brain contributing its pathogenesis. Life stresses may up-regulate inflammatory processes and promote depression. Although cytokines are central to stress-related immune responses, their contribution to stress-induced depression remains unclear. Here, we used unpredictable chronic mild stress (UCMS) to induce depression-like behaviors in mice, as assessed through a suite of behavioral tests. C-X-C motif chemokine ligand 1 (CXCL1)-related molecular networks responsible for depression-like behaviors were assessed through intrahippocampal microinjection of lenti-CXCL1, the antidepressant fluoxetine, the C-X-C motif chemokine receptor 2 (CXCR2) inhibitor SB265610, and the glycogen synthase kinase-3ß (GSK3ß) inhibitor AR-A014418. Modulation of apoptosis-related pathways and neuronal plasticity were assessed via quantification of cleaved caspase-3, B-cell lymphoma 2-associated X protein, cAMP response element-binding protein (CREB), and brain-derived neurotrophic factor (BDNF) protein expression. CXCL1/CXCL2 expression was correlated with depression-like behaviors in response to chronic stress or antidepressant treatment in the UCMS depression model. Intrahippocampal microinjection of lenti-CXCL1 increased depression-like behaviors, activated GSK3ß, increased apoptosis pathways, suppressed CREB activation, and decreased BDNF. Administration of the selective GSK3ß inhibitor AR-A014418 abolished the effects of lenti-CXCL1, and the CXCR2 inhibitor SB265610 prevented chronic stress-induced depression-like behaviors, inhibited GSK3ß activity, blocked apoptosis pathways, and restored BDNF expression. The CXCL1/CXCR2 axis appears to play a critical role in stress-induced depression, and CXCR2 is a potential novel therapeutic target for patients with depression.-Chai, H.-H., Fu, X.-C., Ma, L., Sun, H.-T., Chen, G.-Z., Song, M.-Y., Chen, W.-X., Chen, Y.-S., Tan, M.-X., Guo, Y.-W., Li, S.-P. The chemokine CXCL1 and its receptor CXCR2 contribute to chronic stress-induced depression in mice.

Exploring the impact of therapeutic advances in HIV-related mortality in the United States.

Objectives: Mortality from HIV has significantly declined with the introduction of highly active antiretroviral therapy (HAART). This study sought to examine the longitudinal trends in mortality from HIV-related diseases by race, sex, geographical region, and over time as HAART trends changed. Methods: We queried the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research database and performed serial cross-sectional analyses of national death certificate data for all-cause mortality with comorbid HIV from 1999 to 2020. HIV diseases (International Classification of Diseases, Tenth Revision codes B20-B24, O98.7, R75) were listed as the contributing cause of death. We calculated the age-adjusted mortality ratio (AAMR) per 1,000,000 individuals and determined mortality trends using the Joinpoint Regression Program. Subgroup analyses were performed by sex, race, region, and organ system. The study period was further stratified into three groups when specific drug regimens were more prevalent. Results: In the 22-year study period, 251,759 all-cause mortalities with comorbid HIV were identified. The leading cause of death was infectious disease (84.0%, N = 211,438). Men recorded a higher AAMR than women (4.66 vs 1.65, P < 0.01). African American individuals had the highest AAMR (13.46) compared to White, American Indian, and Asian individuals (1.70 vs 1.65 vs 0.47). The South region had the highest AAMR (4.32) and urban areas had a higher AAMR compared to rural areas (1.77 vs 0.88). Conclusions: More than 80% of deaths occurred because of infectious disease over the last 2 decades with a decreasing trend over time when stratified by race, sex, and geographical region. Despite advances in HAART, mortality disparities persist which emphasizes the need for targeted interventions in these populations.