Fourier transform infrared spectroscopic imaging of cardiac tissue to detect collagen deposition after myocardial infarction

Abstract

Abstract. Myocardial infarction often leads to an increase in deposition of fibrillar collagen. Detection and characterization of this cardiac fibrosis is of great interest to investigators and clinicians. Motivated by the significant limitations of conventional staining techniques to visualize collagen deposition in cardiac tissue sections, we have developed a Fourier transform infrared imaging spectroscopy (FT-IRIS) methodology for collagen assessment. The infrared absorbance band centered at 1338 cm −1 , which arises from collagen amino acid side chain vibrations, was used to map collagen deposition across heart tissue sections of a rat model of myocardial infarction, and was compared to conventional staining techniques. Comparison of the size of the collagen scar in heart tissue sections as measured with this methodology and that of trichrome staining showed a strong correlation (R ¼ 0.93). A Pearson correlation model between local intensity values in FT-IRIS and immuno-histochemical staining of collagen type I also showed a strong correlation (R ¼ 0.86). We demonstrate that FT-IRIS methodology can be utilized to visualize cardiac collagen deposition. In addition, given that vibrational spectroscopic data on proteins reflect molecular features, it also has the potential to provide additional information about the molecular structure of cardiac extracellular matrix proteins and their alterations.

FTIR Imaging of Tissues: Techniques and Methods of Analysis

“…In this case, the size of collagen scarring decreased from 18.7 to 1.6 % as revealed by the FtIR technique and was comparable to the staining results. these findings demonstrate that FtIR imaging can be a powerful labelfree tool in the evaluation of collagen deposition and remodelling after myocardial infarction [148]. the observation of collagen fibrosis by using FtIR imaging has been also reported for the cardiomyopathy induced by an infection with coxsackievirus, recognized as a highly active etiological agent in the development of myocarditis [149].…”

“…FtIR monitoring of the treatment of infarcted rat myocardium by targeted delivery of vascular endothelial growth factor (vEgF) has been reported by Cheheltani et al [148]. here, collagen deposition in the infarct zone of the left ventricles was mapped using the integrated intensity of a band at 1338 cm −1 , because only this IR maximum was found to be specific for collagen in the investigated tissue sections [148].…”

“…here, collagen deposition in the infarct zone of the left ventricles was mapped using the integrated intensity of a band at 1338 cm −1 , because only this IR maximum was found to be specific for collagen in the investigated tissue sections [148]. the maps were then compared with immunostaining for collagen I by Alexa Fluor 594 donkey anti-mouse Igg and the two histological staining protocols by using trichrome and picrosirius red, which also illustrated the distribution of collagen of type I.…”

Analysis of saliva by Fourier transform infrared spectroscopy for diagnosis of physiological stress in athletes

“…Many studies demonstrated high sensitivity of FT-IR to analyze the skeletal muscle (Jerônimo et al, 2012), heart muscle (Cheheltani et al 2012), and some biological fluids, such as serum (Carvalho et al, 2014), urine (Khaskheli et al, 2013), and saliva (Khaustova et al, 2010).…”

Infrared spectroscopic imaging: Label-free biochemical analysis of stroma and tissue fibrosis

“…Other investigations have searched for the spectral signatures of collagen within human tissues in such diverse contexts as gliomas (Noreen et al, 2012), cardiomyopathy (Gough et al, 2003; Wang et al, 2005), myocardial infarction (Cheheltani et al, 2012), wound healing (Wiens et al, 2007), and articular cartilage (Saarakkala et al, 2010). It has also been suggested that serum can be measured using FT-IR as a surrogate for hepatic fibrosis (Scaglia et al, 2011).…”