RhoG Is Upregulated in Neutrophils and Monocytes Isolated from Peripheral Blood of Septic Patients and Animals and Regulates Migration and Inflammatory Functions in Innate Immune Cells in Vitro

Nibedita Dalpati – Indian Institute of Technology Roorkee; Pankaj Dipankar – Indian Institute of Technology; Saloni Gupta – Indian Institute of Technology Roorkee; Shubham Rai – Indian Institute of Technology Roorkee; Prerna Sharma – Indian Institute of Technology Roorkee; Divya Singh – Indian Institute of Technology Roorkee

Abstract Text: Rho GTPases RhoG is a regulator of cellular processes and plays a key role in modulating inflammatory responses. Despite its importance in cellular functioning and various diseases, the role of RhoG in the context of sepsis remains unexplored. Findings from the present study show that RhoG transcripts and protein were upregulated in human peripheral blood neutrophils, monocytes, and macrophages upon stimulation with Lipopolysaccharide (LPS), TNF-α, and chemokines in vitro. Higher RhoG expression was also observed in the neutrophils and monocytes isolated from septic mice and patients. Interestingly, the presence of fibronectin altered RhoG transcript expression, and blocking integrin β1 significantly reduced RhoG transcripts in inflammatory cells. Knockdown of RhoG significantly decreased the cell viability, which was restored in the presence of fibronectins. A significant reduction in differentiation and adhesion markers (e.g., CD14, MHC-II, CD11b, and integrin ⍺4) and the production of proinflammatory cytokines (IL-1β and IL-6) was observed in primary monocytes. Knockdown of RhoG significantly increased cell spreading, migration, and velocity in both primary monocytes and differentiated HL-60 (neutrophil-like cells). Bioinformatic analysis linked RhoG to several proteins such as ELMO1/2, PIK3CB- AKT, DOCK1/2/5, and TRIO/KALRN. These findings indicate that RhoG plays an essential role in inflammatory response in sepsis by regulating immune cells and crosstalk with integrin β1.