MiR-21-3p Plays a Crucial Role in Metabolism Alteration of Renal Tubular Epithelial Cells during Sepsis Associated Acute Kidney Injury via AKT/CDK2-FOXO1 Pathway

Abstract

Objective. Sepsis and associated acute kidney injury (SAKI) are determined to be closely related to poor prognosis. Because the metabolic alterations of tubular epithelial cells (TECs) are crucial for the occurrence and development of SAKI, we carried out this present study to identify the metabolism changes of TECs during SAKI and relevant mechanisms. Methods. Rat SAKI model and rat tubular epithelial cell line were used in our study. ELISA was used to determine the serum cytokines levels. Protein expressions were examined with Western-Blotting and the transcriptions of RNAs were determined with qRT-PCR. ADP/ATP assay and Oil Red O staining were used to examine the energy and lipid metabolism, respectively. Dual-luciferase reporter assay was carried out to determine the interactions between miRNA and specific proteins. Cell cycle arrest and apoptosis were determined with flow cytometry. Results. Sepsis and AKI were induced 12 h after CLP. Energy and lipid metabolism reduced significantly while FOXO1 levels increased remarkably in TECs during SAKI. The expressions of both AKT and CDK2 and the transcriptions of relevant mRNAs reduced significantly in TECs during SAKI while miR-21-3p expression increased remarkably. Both AKT and CDK2 were determined as the direct targets of miR-21-3p. Furthermore, by in vitro experiments, it was demonstrated that FOXO1 levels were regulated by miR-21-3p in TECs via AKT/CDK2 and AKT/CDK2-FOXO1 pathway was crucial in the regulations of miR-21-3p on lipid metabolism, cell cycle arrest, and apoptosis of TECs. Conclusions. MiR-21-3p mediates metabolism and cell fate alterations of TECs via manipulating AKT/CDK2-FOXO1 pathway, and that is crucial in the regulation of energy metabolism of TECs during SAKI.

Nrp-1 Mediated Plasmatic Ago2 Binding miR-21a-3p Internalization: A Novel Mechanism for miR-21a-3p Accumulation in Renal Tubular Epithelial Cells during Sepsis

“…It can be found out with RT-PCR that both the miR-21a-3p levels in plasma and TECs increased significantly 12 h after the CLP procedure ( Figure 1(a) ). Because it was well studied that sepsis was induced 12 h after CLP in rats in our former studies [ 19 ], the present results indicated that the miR-21a-3p levels in both plasma and TECs were increased significantly during sepsis. Ago2 was known as one of the most important binding proteins of miRs in circulation and miRs were stabilized only if they bind to Ago2 or were present in exosomes in circulation.…”

“…In our recent study on SAKI, miR-21a-3p was revealed to accumulate in TECs during sepsis and was verified to mediate metabolism and cell fate alteration of TECs via manipulating the AKT/CDK2-FOXO1 pathway. Moreover, this mechanism played a novel role in the regulation of energy metabolism of TECs during SAKI [ 19 ]. However, the mechanisms underlying sepsis-induced miR-21a-3p accumulation in the TECs have not been elucidated.…”

Acute Kidney Injury in Septic Patients Treated by Selected Nephrotoxic Antibiotic Agents—Pathophysiology and Biomarkers—A Review

“…Each regulates positively or negatively a different part of the biochemical cascade to final cytokine production and tissue damage according to their target genes [ 23 , 24 ]. In the development of septic AKI, severe metabolic alterations of tubular epithelial cells may play a crucial role via miR-21-3p influence on the AKT/CDK2-FOXO1 pathway, with induction of cycle cell arrest and apoptosis [ 25 ]. According to one human study (Ge et al, 2017), many other signaling pathways are involved in septic AKI development, including oxidative stress and mitochondrial dysfunction pathways ( HIF-1 , PI3K-Akt , mTOR and TGFβ ).…”

The predictive value of microRNA‐21 for sepsis risk and its correlation with disease severity, systemic inflammation, and 28‐day mortality in sepsis patients

“…MiR‐21 is ubiquitously expressed in multiple organs such as heart and kidney, which participates in the processes of inflammation process and organ malfunction associated with sepsis . For instance, overexpression of miR‐21 reduces TNF‐α level, while the inhibition of miR‐21 upregulates TNF‐α and IL‐6 levels .…”

“…MiR-21 is ubiquitously expressed in multiple organs such as heart and kidney, which participates in the processes of inflammation process and organ malfunction associated with sepsis. [14][15][16][17] For instance, overexpression of miR-21 reduces TNF-α level, while the inhibition of miR-21 upregulates TNF-α and IL-6 levels. 16 Another study exhibits that knockdown of miR-21 facilitates the expression of programmed cell death protein 4 and phosphatase and tensin homolog deleted on chromosome 10, which results in an elevation in apoptosis and exacerbation of LPS-induced septic acute kidney injury.…”