Premium
Indoxyl Sulfate Exposure inhibits Vascular Smooth Muscle Cell migration and Potentiates Vascular Injury
Author(s) -
Carr Sean,
Okon Imoh,
Zou Ming-hui
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.04453
Subject(s) - focal adhesion , paxillin , vascular smooth muscle , microbiology and biotechnology , cell migration , chemistry , actin , western blot , actin cytoskeleton , cell , vinculin , cell adhesion , gene silencing , cytoskeleton , biology , biochemistry , endocrinology , smooth muscle , gene
Chronic Kidney Disease (CKD) has been implicated in cardiovascular complications. CKD results in decreased filtration and a concomitant increase in uremic toxins. Uremic toxins are a by‐product of organic molecules, including two prominent amino acid derivatives, namely Indoxyl sulfate (IS) obtained from tryptophan and p‐Cresyl sulfate from tyrosine. Of these uremic toxins, IS has been shown to be highly potent, and implicated in exacerbation of multiple cardiovascular diseases. However, the effect of IS during vascular injury and specific contributions of Vascular Smooth Muscle Cells (VSMCs) remain unclear. Methods Transwell migration and cell attachment assays were employed to examine the phenotypic effects of IS on VSMCs. Western blot analysis, gene silencing, and Immunofluorescence microscopy were utilized to examine the effects of IS on focal adhesion and actin related proteins. Results Exposure of VSMCs to IS resulted in the formation of stress fibers and cytoskeletal disorganization. In the presence or absence of chemoattractants, we observed decreased migration of IS‐treated cells. Additionally, a noticeable reduction in cell area and cell attachment was evident. This led to investigation of focal adhesion, and actin‐related proteins due to their established roles in cell migration. It was determined that Focal Adhesion Kinase (FAK) and Paxillin were significantly decreased after prolonged exposure to IS. Immunofluorescence microscopy confirmed decreased FAK and Paxillin intensity at the cell periphery of IS‐treated cells. To determine whether FAK or Paxillin were the main effectors of decreased cell migration instigated by IS, gene silencing was performed. Relative to Paxillin, loss of FAK expression correlated with a reduction VSMC migration. Conclusion These data suggest that IS contributes to alterations to focal adhesion related proteins, which in turn attenuates cell migration. IS induced loss of FAK potentiates reduced migration. Thus, IS‐induced inhibition of vascular repair may contribute to secondary complications in a subset of CVD patients. Support or Funding Information National Institutes of Health