Insulin resistance and obesity affect monocyte-derived dendritic cell phenotype and function

Area of Science:

• Immunology
• Endocrinology
• Cardiovascular Science

Background:

• Cardiovascular disease (CVD) is common in post-menopausal women, linked to obesity and insulin resistance.
• Immunological mechanisms, particularly dendritic cells (DCs), play a role in vascular remodeling, but their specific function in this context is unclear.

Purpose of the Study:

• To characterize monocyte-derived dendritic cells (Mo-DCs) in post-menopausal women with type 2 diabetes (T2DM) and obesity.
• To investigate Mo-DC function and phenotype in relation to atherosclerosis risk factors.

Main Methods:

• Phenotypic and functional characterization of Mo-DCs using flow cytometry and mixed lymphocyte reactions.
• Assessment of mRNA integrin expression and circulating fetuin-A and adiponectin levels.

Main Results:

• Mo-DCs showed phenotypic dysregulation, defective lymphocyte stimulation, and increased mRNA for adhesion molecules (CD11c, CD18, DC-SIGN/CD209).
• Altered fetuin-A and adiponectin levels were observed, negatively correlated with each other.
• Hyperglycemia impaired the conversion of CD14+ cells into Mo-DCs.

Conclusions:

• Mo-DCs are dysfunctional in obese, post-menopausal women with T2DM, even without clinical CVD.
• The combination of obesity and diabetes exacerbates Mo-DC dysfunction, potentially increasing vascular inflammation.