Increased expression of ELOVL7 contributes to production of inflammatory cytokines in THP-1 cell-derived M1-like macrophages

Peripheral immune profiling highlights a dynamic role of low-density granulocytes in myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) is an autoimmune neuromuscular disease marked by dysregulation of several immune cell populations. Here we explored peripheral immune landscape, particularly the role of low-density granulocytes (LDGs).

METHODS

Single-cell and bulk RNA sequencing analyzed peripheral immune cells from MG patients pre- (n = 4) and after treatment (n = 2), as well as healthy controls (n = 3). Flow cytometry was employed for validating LDG subsets, and various functional assays were conducted to assess their impact on T cell proliferation and differentiation, NET formation, and ROS production.

RESULTS

Single-cell analysis highlighted a shift towards inflammatory Th1/Th17/Tfh subsets, an intense interferon-mediated immune response, and an expansion of immature myeloid subsets in MG. Flow cytometry showed increased LDGs correlated with disease severity. Unlike myeloid-derived suppressor cells, MG LDGs do not restrict T cell proliferation but induce a pro-inflammatory Th1/Th17 response. They also display enhanced spontaneous neutrophil extracellular traps (NETs) formation and basal reactive oxygen species (ROS) production. LDGs decreased after intravenous immunoglobulin and increased after prolonged immunotherapy in minimal manifestation status (MM), with reduced pro-inflammatory activity. Bulk RNA sequencing revealed significant transcriptional differences in LDGs, especially in cell cycle and granule protein genes.

CONCLUSION

Peripheral immune profiling sheds light on the intricate role of LDGs in MG. These cells, as a distinct subtype of neutrophils with a proinflammatory phenotype, are notable increased in MG, exacerbating chronic inflammation. Furthermore, immunotherapy expanded LDGs but reduced their proinflammatory capacities. The complex interplay of LDGs in MG underscores their potential as biomarkers and therapeutic targets.

Identification and validation of core genes associated with polycystic ovary syndrome and metabolic syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder affecting women of reproductive age, affecting reproductive health, and increasing the incidence of diabetes mellitus and hypertension. Metabolic syndrome (MetS) is the most common metabolic disorder. Although clinical studies have shown a close association between PCOS and MetS, the molecular mechanisms are unknown. In this study, datasets of PCOS and MetS were obtained from the Gene Expression Omnibus database; differential expression analysis and weighted gene coexpression network analysis (WGCNA) were performed; and gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses also performed of differentially expressed genes (DEGs). The PCOS- and MetS-coexpressed DEGs were subsequently intersected with the coexpressed genes in the WGCNA module to obtain the core genes. By constructing receiver operating characteristic curves, we verified the predictive effects of the core genes. We also validated the expression of the core genes in the datasets. Finally, we verified the expression of the core genes by quantitative polymerase chain reaction in human follicular fluid granulosa cells. In addition, we used Cell-type Identification By Estimating Relative Subsets Of RNA Transcripts to analyze the immune infiltration of immune cells in PCOS and MetS. Finally, we obtained 52 coexpressed DEGs of PCOS and MetS and 3 coexpressed genes in the WGCNA module. By taking the intersection of coexpressed DEGs and coexpressed genes of the WGCNA module, we get ELOVL fatty acid elongase 7 (ELOVL7) as the core gene. Receiver operating characteristic curve analysis showed that ELOVL7 is a reliable biological marker for PCOS and MetS. The expression level of ELOVL7 in human follicular fluid granulosa cells from PCOS patients was significantly higher than that of controls, as verified by quantitative polymerase chain reaction. This study provides the first evidence of the role of ELOVL7 in developing PCOS and MetS. This gene may serve as a potential diagnostic marker and therapeutic target for both conditions.

Delayed simvastatin treatment improves neurological recovery after cryogenic traumatic brain injury through downregulation of ELOVL1 by inhibiting mTOR signaling

Statins are well-tolerated and widely available lipid-lowering medications with neuroprotective effects against traumatic brain injury (TBI). However, whether delayed statin therapy starting in the subacute phase promotes recovery after TBI is unknown. Elongation of the very long-chain fatty acid protein 1 (ELOVL1) is involved in astrocyte-mediated neurotoxicity, but its role in TBI and the relationship between ELOVL1 and statins are unclear. We hypothesized that delayed simvastatin treatment promotes neurological functional recovery after TBI by regulating the ELOVL1-mediated production of very long-chain fatty acids (VLCFAs). ICR male mice received daily intragastric administration of 1, 2 or 5 mg/kg simvastatin on Days 1-14, 3-14, 5-14, or 7-14 after cryogenic TBI (cTBI). The results showed that simvastatin promoted motor functional recovery in a dose-dependent manner, with a wide therapeutic window of at least 7 days postinjury. Meanwhile, simvastatin inhibited astrocyte and microglial overactivation and glial scar formation, and increased total dendritic length, neuronal complexity and spine density on day 14 after cTBI. The up-regulation of ELOVL1 expression and saturated VLCFAs concentrations in the cortex surrounding the lesion caused by cTBI was inhibited by simvastatin, which was related to the inhibition of the mTOR signaling. Overexpression of ELOVL1 in astrocytes surrounding the lesion using HBAAV2/9-GFAP-m-ELOVL1-3xFlag-EGFP partially attenuated the benefits of simvastatin. These results showed that delayed simvastatin treatment promoted functional recovery and brain tissue repair after TBI through the downregulation of ELOVL1 expression by inhibiting mTOR signaling. Astrocytic ELOVL1 may be a potential target for rehabilitation after TBI.

Dexmedetomidine ameliorates diabetic intestinal injury by promoting the polarization of M2 macrophages through the MMP23B pathway

BACKGROUND

Diabetes is often associated with gastrointestinal dysfunctions, which can lead to hypoglycemia. Dexmedetomidine (DEX) is a commonly used sedative in perioperative diabetic patients and may affect gastrointestinal function.

AIM

To investigate whether sedative doses of DEX alleviate diabetes-caused intestinal dysfunction.

METHODS

Sedation/anesthesia scores and vital signs of streptozotocin (STZ)-induced diabetic mice under DEX sedation were observed. Diabetic mice were divided into saline and DEX groups. After injecting sedatives intraperitoneally, tight junctions (TJs) and apoptotic levels were evaluated 24 hours later to assess the intestinal barrier function. The role of DEX was validated using Villin-MMP23B flox/flox mice with intestinal epithelial deletion. In vitro, high glucose and hyperosmolarity were used to culture Caco-2 monolayer cells with STZ inter-vention. Immunofluorescence techniques were used to monitor the barrier and mitochondrial functions.

RESULTS

MMP23B protein levels in the intestinal tissue of STZ-induced diabetic mice were significantly higher than those in the intestinal tissue of control mice, with the DEX group displaying decreased MMP23B levels. Diabetes-mediated TJ dis-ruption, increased intestinal mucosal permeability, and systemic inflammation in wild-type mice might be reversed by DEX. In Caco-2 cells, MMP23B was associated with increased reactive oxygen species accumulation, mitochondrial membrane potential depolarization, and TJ disruption.

CONCLUSION

DEX reduces MMP23B, which may potentially contribute to STZ-induced intestinal barrier dysfunction, affecting TJ modification through mitochondrial dysfunction.

Effect of tumor-associated macrophages on the pyroptosis of breast cancer tumor cells

Macrophages are immune cells with high plasticity that are widely distributed in all tissues and organs of the body. Under the influence of the immune microenvironment of breast tumors, macrophages differentiate into various germline lineages. They exert pro-tumor or tumor-suppressive effects by secreting various cytokines. Pyroptosis is mediated by Gasdermin family proteins, which form holes in cell membranes and cause a violent inflammatory response and cell death. This is an important way for the body to fight off infections. Tumor cell pyroptosis can activate anti-tumor immunity and inhibit tumor growth. At the same time, it releases inflammatory mediators and recruits tumor-associated macrophages (TAMs) for accumulation. Macrophages act as "mediators" of cytokine interactions and indirectly influence the pyroptosis pathway. This paper describes the mechanism of action on the part of TAM in affecting the pyroptosis process of breast tumor cells, as well as its key role in the tumor microenvironment. Additionally, it provides the basis for in-depth research on how to use immune cells to affect breast tumors and guide anti-tumor trends, with important implications for the prevention and treatment of breast tumors. Video Abstract.