Besides glomerulus tubulo-interstitium is often concomitantly affected in certain diseases, e.g., diabetic nephropathy, and activation of renin-angiotensin system, to a certain extent, worsens its outcome because of perturbations in hemodynamics and possibly tubulo-glomerular feedback. Certain studies suggest that pathobiology of tubulo-interstitial is influenced by small GTPases, e.g., Rap1. We investigated effect of Ang II on inflammatory cytokines, while at the same time focusing on upstream effector of Rap1, i.e., Epac1, and some of the downstream tubular transport molecules, i.e., NHE3. Ang II treatment of LLC-PK1 cells decreased Rap1a GTPase activity in a time- and dose-dependent manner. While Ang II treatment led to an increased membrane translocation of NHE3, which was reduced with Epac1 and PKA activators. Ang II-induced NHE3 translocation was notably reduced with transfection of Rap1a dominant positive mutants, i.e., Rap1a-G12V or Rap1a-T35A. While transfection of cells with dominant negative Rap1a mutants, i.e., Rap1a-S17A, or with Epac1 mutant, i.e., EPAC-cAMP, normalized the Ang II-induced translocation of NHE3. In addition, Ang II treatment led to an increased expression of inflammatory cytokines, i.e., IL-1β, IL-6, IL-8 and TNF-α, which was reduced with Rap1a-G12V or Rap1a-T35A transfection; while it reverted to previous comparable levels following transfection of Rap1a-S17A or EPAC-cAMP. Ang II-induced expression of cytokines was reduced with the treatment of NHE3 inhibitor, S3226, or with Epac1 and PKA activators. These data suggest that this novel Epac1-Rap1a-NHE3 pathway conceivably modulates the Ang II-induced expression of inflammatory cytokines, and this information may aid in developing strategies to reduce tubulo-intertstitial inflammation in renal diseases.