Reversing Acute Kidney Injury Using Pulsed Focused Ultrasound and MSC Therapy: A Role for HSP-Mediated PI3K/AKT Signaling

Mujib Ullah; Daniel D Liu; Sravanthi Rai; Arya Dadhania; Sriya Jonnakuti; Waldo Concepcion; Avnesh S Thakor

doi:10.1016/j.omtm.2020.03.023

Reversing Acute Kidney Injury Using Pulsed Focused Ultrasound and MSC Therapy: A Role for HSP-Mediated PI3K/AKT Signaling

Mol Ther Methods Clin Dev. 2020 Mar 30:17:683-694. doi: 10.1016/j.omtm.2020.03.023. eCollection 2020 Jun 12.

Authors

Mujib Ullah¹, Daniel D Liu¹, Sravanthi Rai¹, Arya Dadhania¹, Sriya Jonnakuti¹, Waldo Concepcion¹, Avnesh S Thakor¹

Affiliation

¹ Interventional Regenerative Medicine and Imaging Laboratory, Department of Radiology, Stanford University, Palo Alto, CA, USA.

Abstract

Acute kidney injury (AKI) is characterized by a sudden failure of renal function, but despite increasing worldwide prevalence, current treatments are largely supportive, with no curative therapies. Mesenchymal stromal cell (MSC) therapy has been shown to have a promising regenerative effect in AKI but is limited by the ability of cells to home to damaged tissue. Pulsed focused ultrasound (pFUS), wherein target tissues are sonicated by short bursts of sound waves, has been reported to enhance MSC homing by upregulating local homing signals. However, the exact mechanism by which pFUS enhances MSC therapy remains insufficiently explored. In this study, we studied the effect of bone marrow-derived MSCs (BM-MSCs), in conjunction with pFUS, in a mouse model of cisplatin-induced AKI. Here, BM-MSCs improved kidney function, reduced histological markers of kidney injury, decreased inflammation and apoptosis, and promoted cellular proliferation. Surprisingly, whereas pFUS did not upregulate local cytokine expression or improve BM-MSC homing, it did potentiate the effect of MSC treatment in AKI. Further analysis linked this effect to the upregulation of heat shock protein (HSP)20/HSP40 and subsequent phosphatidylinositol 3-kinase (PI3K)/Akt signaling. In summary, our results suggest that pFUS and BM-MSCs have independent as well as synergistic therapeutic effects in the context of AKI.

Keywords: acute kidney injury; apoptosis; focused ultrasound; heat shock protein; inflammation; kidney regeneration; mesenchymal stromal cell; signaling.