Molecular profiling of the intestinal mucosa and immune cells of the colon by multi-parametric histological techniques

Łukasz Zadka,Łukasz Szleszkowski,Kamilla Malek,Krzysztof Kurnol,Karolina Chrabaszcz,Aleksandra Piotrowska,Tomasz Jurek,Igor Buzalewicz,Natalia Glatzel-Plucińska,Ewelina Wiercigroch,Agnieszka Gomułkiewicz,Piotr Dzięgiel

doi:10.1038/s41598-021-90761-y

Abstract

The impact of the post-mortem interval (PMI) on the optical molecular characteristics of the colonic mucosa and the gut-associated lymphoid tissue (GALT) were examined by multi-parametric measurements techniques. Inflammatory cells were identified by immunohistochemical staining. Molecular parameters were estimated using the Raman spectroscopy (RS) and Fourier Transform Infrared (FTIR) spectroscopic imaging. The 3D refractive index (3D-RI) distributions of samples were determined using the digital holographic tomography. The distribution of immune cells between post-mortem (PM) and normal controls did show significant differences for CD4 (P = 0.0016) or CD8 (P < 0.0001), whose expression level was decreased in PM cases. No association was found between individual PMI values and inflammatory cell distribution. However, there was a tendency for a negative correlation between CD4+ cells and PMI (r = − 0.542, P = 0.032). The alterations ongoing in post-mortem tissue may suggest that PMI has a suppressive effect on the effector properties of the cell-mediated immunity. Moreover, it was confirmed that spectroscopic and digital holotomographic histology are also a useful technique for characterization of the differences in inflammation of varying intensity and in GALT imaging in a solid tissue. Anatomical location of immune cells and methods of tissue fixation determine the molecular and optical parameters of the examined cases.

Highlights

The impact of the post-mortem interval (PMI) on the optical molecular characteristics of the colonic mucosa and the gut-associated lymphoid tissue (GALT) were examined by multi-parametric measurements techniques
It is assumed that changes in molecular parameters may occur during the post-mortem interval (PMI) especially with regard to gene and protein expression level, which can lead to changes at the cellular response[1]
Antigens with performing significant functions in adaptive immunity such as CD45, CD331, CD4 and CD8 were selected for immunohistochemistry reactions (IHC)

Summary

Introduction

The impact of the post-mortem interval (PMI) on the optical molecular characteristics of the colonic mucosa and the gut-associated lymphoid tissue (GALT) were examined by multi-parametric measurements techniques. A research autopsy is commonly used, since it allows to expand the knowledge about the complex biology of cancer and the mechanism of metastasis formation[1], there is a wide acceptance of donors’ relatives for the use of post-mortem samples for medical research[2]. These tissues are extensively used in both clinical and forensic analyses, in the case of toxicological tests[3,4]. GALT is an important organ in pathology, as it is the starting point for some gastrointestinal tumors with specific tissue characteristics[7]

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