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Abstract: TH-PO767

Extracellular Matrix Stiffening by Sugars: Implications for Diabetic Nephropathy

Session Information

  • Bioengineering
    October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Bioengineering

  • 300 Bioengineering

Authors

  • Sant, Snehal, Vanderbilt University Medical Center, Nashville, Tennessee, United States
  • Ferrell, Nicholas J., Vanderbilt University Medical Center, Nashville, Tennessee, United States
Background

Stiffening of the extracellular matrix (ECM) contributes to a number of diseases including cancer and organ fibrosis. Diabetes leads to formation of advanced glycation end products (AGEs) that crosslink the ECM and may lead to increased matrix stiffness. The pathological consequences of ECM stiffening in diabetes are not fully understood and may be a mechanism by which AGEs contribute to disease progression is diabetic nephropathy. The goal of this work was to evaluate the effectiveness of AGE inhibitors in mitigating sugar-induced ECM stiffening of decellularized kidney ECM.

AGEs are known to elicit receptor-mediated pathogenic effects that are independent of ECM stiffening. In order to evaluate the specific effects of ECM stiffening, we developed a novel ex vivo model to alter the mechanical properties of the ECM to evaluate effects on tubular epithelial cell function.

Methods

To evaluate the effects of sugar exposure on ECM stiffness, porcine kidney cortex was detergent decellularized and incubated in reducing sugars (glucose and ribose). The elastic modulus of sugar-modified ECM was measured by compression testing in the presence and absence of the AGE inhibitors pyridoxamine and DTPA. To evaluate cellular response to ECM stiffening, decellularized kidney cortical ECM was crosslinked with genipin. Tubular epithelial cells were cultured on genipin stiffened ECM and matrix and growth factor gene expression were analyzed by qRT-PCR.

Results

Sugar incubation resulted in a concentration-dependent increase in ECM stiffness in the presence of both glucose and ribose. Both PM and DTPA reduced ECM stiffening by glucose and ribose, but were most effective in the presence of glucose. Genipin modification of decellularized ECM resulted in a dose-dependent increase in stiffness that was similar to that induced by sugar modification. Tubular epithelial cells grown on genipin modified ECM showed upregulation of collagen IV and connective tissue growth factor gene expression.

Conclusion

These data show that inhibiting AGE formation mitigates sugar-induced ECM stiffening ex vivo. We introduce a method of evaluating cellular response to ECM stiffening by genipin modification of decellularized kidney ECM and show that kidney cells had increased expression of pro-fibrotic genes. These preliminary studies suggest that ECM stiffening may have pathological consequences in diabetic nephropathy.

Funding

  • NIDDK Support