Mimicking kidney flow shear efficiently induces aggregation of LECT2, a protein involved in renal amyloidosis

Jeung-Hoi Ha; Yikang Xu; Harsimranjit Sekhon; Wenhan Zhao; Stephan Wilkens; Dacheng Ren; Stewart N Loh

doi:10.1016/j.jbc.2024.107231

Mimicking kidney flow shear efficiently induces aggregation of LECT2, a protein involved in renal amyloidosis

J Biol Chem. 2024 Mar 26;300(5):107231. doi: 10.1016/j.jbc.2024.107231. Online ahead of print.

Authors

Jeung-Hoi Ha¹, Yikang Xu², Harsimranjit Sekhon¹, Wenhan Zhao², Stephan Wilkens¹, Dacheng Ren³, Stewart N Loh⁴

Affiliations

¹ Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York, USA.
² Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York, USA.
³ Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York, USA; Department of Civil and Environmental Engineering, Syracuse University, Syracuse, New York, USA; Department of Biology, Syracuse University, Syracuse, New York, USA. Electronic address: dren@syr.edu.
⁴ Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York, USA. Electronic address: lohs@upstate.edu.

Abstract

Aggregation of leukocyte cell-derived chemotaxin 2 (LECT2) causes ALECT2, a systemic amyloidosis that affects the kidney and liver. Previous studies established that LECT2 fibrillogenesis is accelerated by the loss of its bound zinc ion and stirring/shaking. These forms of agitation create heterogeneous shear conditions, including air-liquid interfaces that denature proteins, that are not present in the body. Here, we determined the extent to which a more physiological form of mechanical stress-shear generated by fluid flow through a network of narrow channels-drives LECT2 fibrillogenesis. To mimic blood flow through the kidney, where LECT2 and other proteins form amyloid deposits, we developed a microfluidic device consisting of progressively branched channels narrowing from 5 mm to 20 μm in width. Shear was particularly pronounced at the branch points and in the smallest capillaries. Aggregation was induced within 24 h by shear levels that were in the physiological range and well below those required to unfold globular proteins such as LECT2. EM images suggested the resulting fibril ultrastructures were different when generated by laminar flow shear versus shaking/stirring. Importantly, results from the microfluidic device showed the first evidence that the I40V mutation accelerated fibril formation and increased both the size and the density of the aggregates. These findings suggest that kidney-like flow shear, in combination with zinc loss, acts in combination with the I40V mutation to trigger LECT2 amyloidogenesis. These microfluidic devices may be of general use for uncovering mechanisms by which blood flow induces misfolding and amyloidosis of circulating proteins.

Keywords: ALECT2; heparan sulfate; heparin; hydrodynamic shear; microfluidic device; protein misfolding; systemic amyloidosis.

Grants and funding

R56 DK124335/DK/NIDDK NIH HHS/United States