Cellular Contractility Profiles of Human Diabetic Corneal Stromal Cells.

Thi N Lam,Alexander Choi,Jian-Xing Ma,Sarah E Nicholas,Dimitrios Karamichos,Viswanathan Pragasam

doi:10.1155/2021/9913210

Abstract

Diabetic keratopathy is a corneal complication of diabetes mellitus (DM). Patients with diabetic keratopathy are prone to developing corneal haze, scarring, recurrent erosions, and significant wound healing defects/delays. The purpose of this study was to determine the contractility profiles in the diabetic human corneal stromal cells and characterize their molecular signatures. Primary human corneal fibroblasts from healthy, Type 1 DM (T1DM), and Type 2 DM (T2DM) donors were cultured using an established 3D collagen gel model. We tracked, measured, and quantified the contractile footprint over 9 days and quantified the modulation of specific corneal/diabetes markers in the conditional media and cell lysates using western blot analysis. Human corneal fibroblasts (HCFs) exhibited delayed and decreased contractility compared to that from T1DMs and T2DMs. Compared to HCFs, T2DMs demonstrated an initial downregulation of collagen I (day 3), followed by a significant upregulation by day 9. Collagen V was significantly upregulated in both T1DMs and T2DMs based on basal secretion, when compared to HCFs. Cell lysates were upregulated in the myofibroblast-associated marker, α-smooth muscle actin, in T2DMs on day 9, corresponding to the significant increase in contractility rate observed at the same time point. Furthermore, our data demonstrated a significant upregulation in IGF-1 expression in T2DMs, when compared to HCFs and T1DMs, at day 9. T1DMs demonstrated significant downregulation of IGF-1 expression, when compared to HCFs. Overall, both T1DMs and T2DMs exhibited increased contractility associated with fibrotic phenotypes. These findings, and future studies, may contribute to better understanding of the pathobiology of diabetic keratopathy and ultimately the development of new therapeutic approaches.

Highlights

Diabetes mellitus (DM) is a major public health problem and one of the most prevalent chronic diseases worldwide [1]
The gel matrix area seeded with Type 1 DM (T1DM) and Type 2 DM (T2DM) only maintained an average of 136.7 mm2 and 48.9 mm2, respectively
At day 1, we identified an average of 69.3 mm2 reduction in gel area by Human corneal fibroblasts (HCFs) controls compared to a reduction of 109.9 mm2 in matrix area in T1DMs and 211.7 mm2 in T2DMs (Figure 1)

Summary

Introduction

Diabetes mellitus (DM) is a major public health problem and one of the most prevalent chronic diseases worldwide [1]. DM continues to rise in numbers and significance, affecting epidemic proportions globally [2]. In 2014, the World Health Organization (WHO) stated that approximately 422 million adults worldwide were suffering from DM, almost doubling from 4.7% in 1980 to 8.5%. The number of people with DM is projected to further increase since the disease is predominate in adults but children as well [3,4,5]. The etiology of the two most common DM types, Type 1 and Type 2, is a complex interplay of genetics, lifestyle preferences, and environmental factors [6].

Objectives

Methods

Results

Discussion

Conclusion