Search bioRxiv⌕ Search

Biology subjects

Campos, M. M.

Publications and source records attributed to Campos, M. M..

3 recordsLinked to original sources

SEPSIS-INDUCED LIPID DROPLET ACCUMULATION ENHANCES ANTIBACTERIAL INNATE IMMUNITY

Lipid droplets (LDs) are lipid-rich organelles recognized as central players in lipid homeostasis, signaling, and inflammation. While their functions in inflammation are well-documented, the role of LDs in antibacterial immunity and infection resistance remains less understood. In this study, we investigated triglyceride synthesis and LD accumulation in the context of antibacterial innate immunity during sepsis. Our results show that LD accumulation is part of immunometabolic reprogramming in E. coli-infected macrophages. Pharmacological inhibition or genetic knockdown of DGAT1, a key enzyme in triglyceride synthesis, reduced LD formation, bacterial clearance, and pro-inflammatory responses (nitric oxide, PGE2, CCL2, IL-6, IFN-{beta}). Notably, DGAT1 inhibition impaired the expression of several interferon-stimulated genes (ISGs), including viperin, iNOS, cathelicidin, and IGTP, in E. coli-infected macrophages. In a sepsis model, DGAT1 inhibition reduced sepsis-induced LD accumulation in peritoneal cells and decreased levels of CCL2, IFN-{beta}, nitric oxide, and lipid mediators (PGE2, LTB4, and RvD1). Furthermore, DGAT1 inhibition accelerated sepsis-related mortality, coinciding with elevated bacterial loads in the peritoneum and bloodstream at 6 and 24 hours post-sepsis. Our results demonstrate that tryglicerides synthesis and LDs are critical regulators of infection resistance, contributing to both bacterial clearance and the coordination of a protective proinflammatory response during sepsis.

immunology↗

Blockade of Kinin B1 receptor counteracts the depressive-like behavior and mechanical allodynia in ovariectomized mice

Menopause is related to a decline in ovarian estrogen production, affecting the perception of the somatosensory stimulus, changing the immune-inflammatory systems, and triggering depressive symptoms. Inhibition of kinin B1 and B2 receptors (B1R and B2R) inhibits the depressive-like behavior and mechanical allodynia induced by immune-inflammatory mediators in mice. However, there is no evidence on the role of kinin receptors in depressive-like and nociceptive behavior in female mice submitted to bilateral ovariectomy. This study shows that ovariectomized mice (OVX) developed time-related mechanical allodynia and increased immobility time in the tail suspension test (TST). The genetic deletion of B1R, or the pharmacological blockade by selective kinin B1R antagonist R-715 (acute, i.p), reduced the increase of immobility time and mechanical allodynia induced by ovariectomy. Neither genetic deletion nor pharmacological inhibition of B2R (HOE 140, i.p) prevented the behavioral changes elicited by OVX. Our data suggested a particular modulation of kinin B1R in the nociceptive and depressive-like behavior in ovariectomized mice. Selective inhibition of the B1R receptor may be a new pharmacological target for treating pain and depression symptoms in women on the perimenopause/menopause period.

animal behavior and cognition↗

Choroid-resident macrophages maintain local vasculature and RPE integrity and spontaneously regenerate following depletion

The choroid of the eye provides necessary vascular supply to the outer retina across the retinal pigment epithelial (RPE) layer and is a locus of progressive degenerative change in aging and age-related macular degeneration (AMD). Cellular mechanisms that maintain or compromise choroidal vasculature homeostasis are not well understood, complicating therapeutic efforts. We discover here that pharmacological ablation of macrophages normally resident in the adult mouse choroid via blockade of the CSF1 receptor resulted in progressive thinning of the choroid layer and atrophy of the choriocapillaris. Concurrently, choroidal macrophage ablation also induced structural disorganization of the RPE cell layer, downregulation of RPE visual cycle genes, and altered RPE angiogenic factor expression. Suspension of CSF1R blockade following ablation conversely enabled spontaneous regeneration of the choroidal macrophage population, restoring original macrophage distribution and morphological features. Macrophage repopulation significantly ameliorated the ablation-induced changes in RPE structure and angiogenic factor expression and arrested choroidal vascular atrophy. These findings reveal a previously unsuspected trophic function of resident choroidal macrophages in the maintenance of choroidal vasculature and the RPE layer, suggesting that insufficiency of macrophage function may contribute to age- and AMD-associated pathology. Modulating choroidal macrophage support function can constitute a strategy for therapeutic preservation of the choroid and RPE in AMD prevention and treatment. Significance StatementChoroidal atrophy is associated with normal aging and progression in age-related macular degeneration (AMD), a leading cause of blindness. Herein, we identify the choroidal macrophage as a critical player in the homeostatic maintenance of choroid-RPE complex of the eye. Depletion of choroidal macrophages resulted in progressive vascular atrophy, altered structure of retinal pigment epithelial (RPE) cells, and dysregulated RPE expression of visual cycle protein and angiogenic factors, VEGF and PEDF. We discovered that choroidal macrophages can regenerate and repopulate the choroid following depletion, ameliorating RPE alterations and arresting vascular atrophy. Our results suggest that insufficiency of macrophage function may contribute to age- and AMD-associated pathology, and modulation of macrophage support functions may be therapeutically useful in AMD prevention and treatment.

immunology↗