Lipocalin 2 Deficiency Alters Prostaglandin Biosynthesis and mTOR Signaling Regulation of Thermogenesis and Lipid Metabolism in Adipocytes

LCN2: Versatile players in breast cancer

Lipocalin 2 (LCN2) is a secreted glycoprotein that is produced by immune cells, including neutrophils and macrophages. It serves various functions such as transporting hydrophobic ligands across the cellular membrane, regulating immune responses, keeping iron balance, and fostering epithelial cell differentiation. LCN2 plays a crucial role in several physiological processes. LCN2 expression is upregulated in a variety of human diseases and cancers. High levels of LCN2 are specifically linked to breast cancer (BC) cell proliferation, apoptosis, invasion, migration, angiogenesis, immune regulation, chemotherapy resistance, and prognosis. As a result, LCN2 has gained attention as a potential therapeutic target for BC. This article offered an in-depth review of the advancement of LCN2 in the context of BC occurrence and development.

Lipocalin-2 promotes adipose-macrophage interactions to shape peripheral and central inflammatory responses in experimental autoimmune encephalomyelitis

OBJECTIVE

Accumulating evidence suggests that dysfunctional adipose tissue (AT) plays a major role in the risk of developing multiple sclerosis (MS), the most common immune-mediated and demyelinating disease of the central nervous system. However, the contribution of adipose tissue to the etiology and progression of MS is still obscure. This study aimed at deciphering the responses of AT in experimental autoimmune encephalomyelitis (EAE), the best characterized animal model of MS.

RESULTS AND METHODS

We observed a significant AT loss in EAE mice at the onset of disease, with a significant infiltration of M1-like macrophages and fibrosis in the AT, resembling a cachectic phenotype. Through an integrative and multilayered approach, we identified lipocalin2 (LCN2) as the key molecule released by dysfunctional adipocytes through redox-dependent mechanism. Adipose-derived LCN2 shapes the pro-inflammatory macrophage phenotype, and the genetic deficiency of LCN2 specifically in AT reduced weight loss as well as inflammatory macrophage infiltration in spinal cord in EAE mice. Mature adipocytes downregulating LCN2 reduced lipolytic response to inflammatory stimuli (e.g. TNFα) through an ATGL-mediated mechanism.

CONCLUSIONS

Overall data highlighted a role LCN2 in exacerbating inflammatory phenotype in EAE model, suggesting a pathogenic role of dysfunctional AT in MS.

Lipid Metabolism Reprogramming of Immune Cells in Acne: An Update

Acne vulgaris is one of the most widespread skin conditions and the main reason for visiting a dermatologist. Inflammatory response and abnormal infiltrations of immune cells are the main pathogenesis of acne. The increased lipid is the prerequisite for the acne, and the perturbation of lipid composition and content is consistent with the severity of acne. Furthermore, the increased lipid production not only contributes to the occurrence and development of acne, but also sensitizes the function of immune cells. The lipid metabolic dysfunction aggravates the severity of local tissue and provides pro-inflammatory-cytokine cues, which indicates the crucial roles of lipid metabolism on immune cells. Recent advances have demonstrated the lipid metabolism reprogramming of various immune cells in acne lesion. The abnormal lipid accumulation, lipolysis, and fatty acid oxidation lead to the activation and differentiation of immune cells, which promotes the pro-inflammatory cytokines production. Thus, this review discusses the emerging role of lipid metabolism reprogramming of immune cells in the progress of acne and aims to constitute food for others' projects involved in acne research.

Investigation of the growth performance, blood status, gut microbiome and metabolites of rabbit fed with low-nicotine tobacco

Tobacco contains a large amount of bioactive ingredients which can be used as source of feed. The objective of this study was to evaluate the effects of dietary addition of low-nicotine tobacco (LNT) on the growth performance, blood status, cecum microbiota and metabolite composition of meat rabbits. A total of 80 Kangda meat rabbits of similar weight were assigned randomly as four groups, and three of them were supplemented with 5%, 10%, and 20% LNT, respectively, with the other one fed with basal diet as control group. Each experiment group with 20 rabbits was raised in a single cage. The experiments lasted for 40 days with a predictive period of 7 days. The results revealed that LNT supplementation had no significant effect on the growth performance, but increased the half carcass weight compared with control group. Dietary supplemention of LNT decreased the triglycerides and cholesterol content in rabbit serum, and significantly increased the plasma concentration of lymphocytes (LYM), monocytes, eosinophils, hemoglobin HGB and red blood cells. In addition, LNT supplementation significantly changed the microbial diversity and richness, and metagenomic analysis showed that LNT supplementation significantly increased Eubacterium_siraeum_group, Alistipes, Monoglobus and Marvinbryantia at genus level. Moreover, LC–MS data analysis identified a total of 308 metabolites that markedly differed after LNT addition, with 190 significantly upregulated metabolites and 118 significantly downregulated metabolites. Furthermore, the correlation analysis showed that there was a significant correlation between the microbial difference and the rabbit growth performance. Overall, these findings provide theoretical basis and data support for the application of LNT in rabbits.