Label‐free detection of fibrillar collagen deposition associated with vascular elements in glioblastoma multiforme by using multiphoton microscopy

Abstract

Glioblastoma multiforme (GBM-WHO grade IV) is the most common and the most aggressive form of brain tumors in adults with the median survival of 10-12 months. The diagnostic detection of extracellular matrix (ECM) component in the tumour microenvironment is of prognostic value. In this paper, the fibrillar collagen deposition associated with vascular elements in GBM were investigated in the fresh specimens and unstained histological slices by using multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG). Our study revealed the existence of fibrillar collagen deposition in the adventitia of remodelled large blood vessels and in glomeruloid vascular structures in GBM. The degree of fibrillar collagen deposition can be quantitatively evaluated by measuring the adventitial thickness of blood vessels or calculating the ratio of SHG pixel to the whole pixel of glomeruloid vascular structure in MPM images. These results indicated that MPM can not only be employed to perform a retrospective study in unstained histological slices but also has the potential to apply for in vivo brain imaging to understand correlations between malignancy of gliomas and fibrillar collagen deposition.

Longitudinal intravital imaging of cerebral microinfarction reveals a dynamic astrocyte reaction leading to glial scar formation

“…A label‐free SHG imaging have been widely used to monitor the fibrillar collagen in specimens of various fibrotic diseases in skin (Chen et al, 2009), liver (Goh et al, 2019), lung (Kottmann et al, 2015), carotid artery (Megens et al, 2008), eye (Tan et al, 2007), tendon and ligaments (Doras et al, 2011). In brain tissue, SHG imaging was used to investigate the structure and polarity of microtubules in neuronal processes (Dombeck et al, 2003; Van Steenbergen et al, 2019), and collagen deposition in glioblastoma (Jiang et al, 2017). However, to the best of our knowledge, neither the fibrous collagen accumulation and scar formation associated with the brain microinfarcts nor the SHG imaging of them has been reported.…”

Intravital imaging of cerebral microinfarct reveals an astrocyte reaction led to glial scar

“…A label-free SHG imaging have been widely used to monitor the fibrillar collagen in specimens of various fibrotic diseases in skin(Chen, Chen et al, 2009), liver(Goh, Leow et al, 2019), lung(Kottmann, Sharp et al, 2015), carotid artery(Megens, oude Egbrink et al, 2008), eye(Tan, Sun et al, 2007), tendon and ligaments(Doras, Taupier et al, 2011). In brain tissue, SHG imaging was used to investigate the structure and polarity of microtubules in neuronal processes(Dombeck, Kasischke et al, 2003, Van Steenbergen, Boesmans et al, 2019), and collagen deposition in glioblastoma(Jiang, Wang et al, 2017). However, to the best of our knowledge, neither the fibrous collagen accumulation and scar formation associated with the brain microinfarcts nor the SHG imaging of them has been reported.…”

Análise do papel das ciclo-oxigenases e prostaglandina e sintase-1 microssomal na expressão de proteínas de matriz extracelular, integrinas e migração celular em gliobastoma.

“…Além das GAGs a MEC do cérebro é rica em componentes não-fibrilares como proteoglicanos, glicoproteínas, pequenas proteínas ligantes e proteínas matricelulares (Cuddapah et al, 2014;Krishnaswamy et al, 2019). É composta majoritariamente por ácido hialurônico, com a presença de proteoglicanos, como os da família do sulfato de condroitina (agrecan, versican, neurocan e brevican), todos importantes durante a fase de desenvolvimento cerebral; e os da família de proteoglicanos ricos em leucina (decorin, biglican, fosfacan, testican, perlecan, distroglican, agrin, claustrin, glipican, etc) (De Luca, Papa, 2016;Jiang et al, 2017).…”

“…Células de GBM produzem e secretam lamininas no parênquima tumoral de modo independente dos vasos sanguíneos (Tysnes et al, 1999). Kawataki O COL4 participa de vários processos celulares como controle do ciclo celular, proliferação e morte celular (Eyden, Tzaphlidou, 2001;Jiang et al, 2017). A presença de colágenos na MEC de gliomas está intimamente relacionada com o grau do tumor e o nível de invasividade tumoral (Pencheva et al, 2017).…”

“…No SNC, esta molécula é expressa durante o desenvolvimento neural e participa na diferenciação dos neurônios motores da medula espinhal. A VTN é um dos principais componentes organizadores da MEC e desempenha um importante papel na formação e crescimento tumoral (CHEN et al, 2016).…”