ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: FR-PO620

An N-Terminal Truncated Intracellular Isoform of Matrix Metalloproteinase-2 Is Induced by Hyperglycemia and Activates a Primary Innate Immune Response In Vitro

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Song, Sang Heon, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Park, In seong, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Han, Miyeun, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Rhee, Harin, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Seong, Eun Young, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Lee, Dong Won, Pusan National University School of Medicine, Yangsan, Korea (the Republic of)
  • Lee, Soo Bong, Pusan National University School of Medicine, Yangsan, Korea (the Republic of)
  • Kwak, Ihm Soo, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Lovett, David H., University of California San Francisco, San Francisco, California, United States
Background

We have reported that matrix metalloproteinase-2 (MMP-2) exists in two discrete isoforms. The first consists of the classical full length isoform (FL-MMP-2) which is secreted as a latent proenzyme. A second novel isoform is generated by oxidative stress-mediated activation of an alternate promoter in the distal first intron of the MMP-2 gene. This results in synthesis of an N-terminal truncated isoform (NTT-MMP-2) that is intracellular, enzymatically active and concentrated within mitochondria. NTT-MMP-2 triggers mitochondrial-nuclear stress signaling via NF-kB transcriptional cascades. Renal proximal tubule-specific transgenic expression of the NTT-MMP-2 isoform results in regulated necrosis, activation of innate immunity and enhanced sensitivity to ischemia/reperfusion injury. In this study we examined the relationship between hyperglycemia and the induction of NTT-MMP-2 and innate immunity genes using the human HK2 proximal tubule cell line.

Methods

We manufactured the specific siRNA for NTT-MMP-2 and tested the inhibitory efficacy of NTT-MMP-2 for innate immunity-related genes using quantitative PCR in HK2 cells with high glucose stimulation.

Results

High glucose medium (30 mM) induced a 1.65±0.06 and a 3.20±0.18 fold increase in FL-MMP-2 and NTT-MMP-2 synthesis as determined by qPCR, respectively (p<0.05 for each). High glucose medium also resulted in statistically significant increases in the expression of the innate immunity genes IFIT1, IRF7, IL6 and CXCL1 including NF-kB. To determine the relationship between high glucose medium enhanced NTT-MMP-2 and innate immune gene expression we developed an NTT-MMP-2 specific siRNA that targets the unique 5’UTR of this gene. Selective siRNA targeting inhibited high glucose mediated NTT-MMP-2 expression to 0.81±0.75 fold (p<0.01), with no effect on FL-MMP-2 expression (1.33±0.28 fold, p>0.05) compared with negative control. The selective NTT-MMP-2 siRNA suppressed high glucose mediated NF-kB expression, as well as IFIT1 ,IRF7, IL6 and CXCL1.

Conclusion

We conclude that selectively targeting NTT-MMP-2 with a siRNA approach offers a therapeutic approach for reduction of tubular epithelial cell necrosis and activation of innate immunity in the setting of diabetes mellitus.

Funding

  • Government Support - Non-U.S.