MON-624 - Microfluidic Analysis Reveals Impaired Neutrophil Nuclear Deformability as the Basis of Migratory Defects in Diabetic Sepsis

Abstract

Background:
Neutrophil transmigration across tissue barriers is essential for host defense but is impaired in sepsis, particularly in patients with diabetes. Although altered nuclear mechanics have been proposed to limit neutrophil migration, direct comparative evidence among diabetic sepsis, non-diabetic sepsis, and healthy individuals is lacking.

Objective:
To determine whether diabetic sepsis differentially alters neutrophil nuclear deformability and migratory capacity using a microfluidic confinement model.

Methods:
Neutrophils were isolated from 21 patients with diabetic sepsis, 18 with non-diabetic sepsis (both meeting Sepsis-3 criteria), and 22 healthy donors. A microfluidic device with 3-µm constrictions was used to mimic physiological tissue barriers. Live-cell imaging tracked neutrophil migration and nuclear remodeling. Nuclear length and aspect ratio were quantified using Image-Pro Plus. Nuclear deformation patterns during migration were classified as C-shaped or O-shaped using K-means clustering.

Results:
Neutrophil nuclei elongated from 7.2 µm to 9.8 µm during confined migration and partially recovered after passage. Both sepsis groups showed reduced nuclear deformability compared with controls, with the most severe impairment in diabetic sepsis. Nuclear aspect ratio was lowest in diabetic sepsis (1.8) versus non-diabetic sepsis (2.1) and controls (2.4; p< 0.01). The proportion of C-shaped nuclei was significantly reduced in diabetic sepsis (32%) compared with non-diabetic sepsis (45%) and controls (68%; p< 0.001). Furthermore, 45% of neutrophils from diabetic sepsis patients failed to traverse 3-µm constrictions, compared with 36% and 12% in non-diabetic sepsis and controls, respectively (p < 0.01). Increased nuclear rigidity was associated with higher rates of cell rupture and NETosis, particularly in diabetic sepsis.

Conclusion:
Diabetic sepsis is associated with profound impairment of neutrophil nuclear deformability and confined migration. These findings identify altered nuclear mechanics as a key contributor to immune dysfunction in diabetic sepsis and highlight cell mechanics as a potential therapeutic target in this high-risk endocrine population.
Keywords: Diabetic Sepsis; Neutrophil Migration; Nuclear Deformability; Microfluidics; Endocrine–Immune Interaction

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