Dataset Information

Microvesicle-Mediated Transfer of DNA Methyltransferase Proteins Results in Recipient Cell Immunosuppression.

ABSTRACT:

Introduction

Patients with sepsis exhibit significant, persistent immunologic dysfunction. Evidence supports the hypothesis that epigenetic regulation of key cytokines plays an important role in this dysfunction. In sepsis, circulating microvesicles (MVs) containing elevated levels of DNA methyltransferase (DNMT) mRNA cause gene methylation and silencing in recipient cells. We sought to examine the functional role of MV DNMT proteins in this immunologic dysfunction.

Methods

In total, 33 patients were enrolled within 24 h of sepsis diagnosis (23 sepsis, 10 critically ill controls). Blood and MVs were collected on days 1, 3, and 5 of sepsis, and protein was isolated from the MVs. Levels of DNMT protein and activity were quantified. MVs were produced in vitro by stimulating naïve monocytes with lipopolysaccharide. Methylation was assessed using bisulfate site-specific qualitative real-time polymerase chain reaction.

Results

The size of MVs in the patients with sepsis decreased from days 1 to 5 compared to the control group. Circulating MVs contained significantly higher levels of DNMT 1 and 3A, protein. We recapitulated the production of these DNMT-containing MVs in vitro by treating monocytes with lipopolysaccharide. We found that exposing naïve monocytes to these MVs resulted in increased promoter methylation of tumor necrosis factor alpha.

Conclusions

An analysis of the isolated MVs revealed higher levels of DNMT proteins in septic patients than those in nonseptic patients. Exposing naïve monocytes to DNMT-containing MVs produced in vitro resulted in hypermethylation of tumor necrosis factor alpha, a key cytokine implicated in postsepsis immunosuppression. These results suggest that DNMT-containing MVs cause epigenetic changes in recipient cells. This study highlights a novel role for MVs in the immune dysfunction of patients with sepsis.

SUBMITTER: Harkless R

PROVIDER: S-EPMC10862496 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature

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Publications

Microvesicle-Mediated Transfer of DNA Methyltransferase Proteins Results in Recipient Cell Immunosuppression.

Harkless Ryan R Singh Kanhaiya K Christman John J McCarty Adara A Sen Chandan C Jalilvand Anahita A Wisler Jon J

The Journal of surgical research 20221122

<h4>Introduction</h4>Patients with sepsis exhibit significant, persistent immunologic dysfunction. Evidence supports the hypothesis that epigenetic regulation of key cytokines plays an important role in this dysfunction. In sepsis, circulating microvesicles (MVs) containing elevated levels of DNA methyltransferase (DNMT) mRNA cause gene methylation and silencing in recipient cells. We sought to examine the functional role of MV DNMT proteins in this immunologic dysfunction.<h4>Methods</h4>In tot ...[more]

PMID: 36427447

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Project description:Metabolism-disorder-induced liver diseases have become increasingly prevalent worldwide and are clinically linked to obesity and type 2 diabetes. In addition, a large number of previous literature studies have indicated that plasma miR-130b is a promising biomarker for the early diagnosis and treatment of obesity. However, whether miRNA-130b that was positively correlated with obesity resulted in hepatic inflammation needs to be further studied. Therefore, the study aims to determine the effect of microvesicle-shuttled miRNA-130b (miR-130b-MV) on the hepatic inflammation and its potential mechanism in high-fat diet-induced obese mice. Three-week-old C57BL/6 mice were fed a high-fat diet for eight weeks. Then, the obese mice received tail vein injections of MV-packaged scrambled control microRNA (miR-SC-MV) or miR-130b-MV every other day for 10 days. Compared with the control group, the miR-130b-MV injection significantly reduced the body weight while increasing the ratio of liver wet weight to total body weight. In addition, the miR-130b-MV injection significantly activated the hepatic inflammation by increasing the expression of proinflammatory genes, although the plasma concentrations of IL-6 and TNF-α were only slightly increased. Furthermore, the miR-130b-MV injection significantly increased the hepatic miR-130b expression while significantly suppressing the protein expression and phosphorylation of GR, a potential target of miR-130b. Moreover, the miR-130b overexpression results in a decrease in the expression of endogenous GR protein and a decrease in the activity of the luciferase reporter of GR 3'-UTR. In addition, the miR-130b-MV injection significantly upregulated NF-kB (p50) in both the cytoplasm and nucleus, showing enhanced proinflammation response. The above results demonstrated that miR-130b-MV activated the hepatic inflammation by inhibiting GR-mediated immunosuppression in high-fat diet-induced obese mice, suggesting a novel mechanism underlying the obesity-induced hepatic inflammation, and the inhibition of miR-130b may serve as a new molecular therapeutic target for the prevention and treatment of hepatic inflammation.

Dataset Information

Microvesicle-Mediated Transfer of DNA Methyltransferase Proteins Results in Recipient Cell Immunosuppression.

Introduction

Methods

Results

Conclusions

Publications

Microvesicle-Mediated Transfer of DNA Methyltransferase Proteins Results in Recipient Cell Immunosuppression.

Similar Datasets

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