Characterization of Ex Vivo and In Vitro Wnt Transcriptome Induced by Spinal Cord Injury in Rat Microglial Cells

Abstract

It is well known that inflammation is crucial in the onset and progression of neurodegenerative diseases and traumatic central nervous system (CNS) injuries, and that microglia and monocyte-derived macrophages (MDMs) play a pivotal role in neuroinflammation. Therefore, the exploration of molecular signaling pathways that are involved in the microglia/macrophage response might help us to shed light on their eventual therapeutic modulation. Interestingly, there is growing evidence showing that the Wnt family of proteins is involved in different neuropathologies that are characterized by a dysregulated neuroinflammatory response, including spinal cord injury (SCI). Here, we aimed to validate a methodology with competence to assess the physiologically relevant Wnt expression patterns of active microglia and MDMs in a rat model of SCI. For that purpose, we have selected and adapted an in vitro system of primary microglia culture that were stimulated with a lesioned spinal cord extract (SCE), together with an ex vivo protocol of flow cytometry sorting of rat microglia/MDMs at different time-points after contusive SCI. Our study demonstrates that the expression profile of Wnt-related genes in microglia/MDM cells exhibit important differences between these particular scenarios which would be in line with previous studies where similar discrepancies have been described for other molecules. Moreover, our results provide for a first experimental report of the Wnt transcriptome in rat microglia and MDMs after SCI which, together with the research platform that was used in the study, and considering its limitations, we expect might contribute to foster the research on Wnt-driven immunomodulatory therapies.

Cellular Metabolism: A Fundamental Component of Degeneration in the Nervous System

“…Programmed cell death pathways during metabolic disorders can affect neuronal cell integrity and lead to the onset of multiple neurodegenerative disorders in the nervous system [94,128,130,149,[166][167][168][169][170][171] (Figure 1). Programmed cell death, a biological process that can represent cellular suicide, can be a significant factor that can oversee the activation of inflammatory pathways during metabolic disorders, such as DM [7,19,39,104,119,126,127,135,[172][173][174].…”

Cognitive Impairment in Multiple Sclerosis

“…Nervous system diseases comprise a large portion of NCDs [2,[29][30][31][32][33][34][35][36][37][38][39][40]. Neurodegenerative disorders impact more than fifteen percent of the global population and comprise greater than six hundred disease entities that can result in severe disability and death [10,37,[41][42][43][44][45][46][47].…”

“…Given the spectrum of the presentations for MS, it should be no surprise that a vast array of cellular mechanisms may foster the onset and progression of MS. Pathways that involve inflammatory mediators, demyelination and remyelination pathways, oxidative stress, blood-brain barrier impairment, viral antigens, and cellular metabolism, which are dependent upon nicotinamide adenine dinucleotide (NAD+), have been tied to the underlying pathology of MS [10,29,31,33,39,43,72,77,85,86,99,100,115,162,171,[179][180][181][182][183][184][185][186][187][188][189][190][191][192][193][194][195][196][197][198]. Although new treatments that address MS, known as disease modifying therapies (DMTs), can limit the rate of relapse in patients with relapsing-remitting MS, DMTs cannot prevent disease progression.…”

“…Two ε4 alleles of APOE-ε4 confers a loss in gene activity that can defend against viral infections leading to disruption of cerebral blood vessels and increased inflammatory activity [155,192]. As a result, individuals with APOE may ex-perience demyelination, cognitive loss, and increased death rates during a SARS-CoV-2 infection [10,15,22,33,38,51,258,277,433,476,477].…”

Cornerstone Cellular Pathways for Metabolic Disorders and Diabetes Mellitus: Non-Coding RNAs, Wnt Signaling, and AMPK

“…Wnt signaling and WISP1 are vital pathways during metabolic disorders and DM for the oversight of oxidative stress, programmed cell death, and non-coding RNA function (Figure 2). Wnt proteins, which are cysteine-rich glycosylated proteins, are part of the wingless pathway that can modulate cell development and survival during aging, cardiovascular disorders, tumorigenesis, organogenesis, neurodegeneration, vascular disease, inflammation, and DM [25,28,48,76,92,115,131,150,184,276,296,297,305,307,338,339,[457][458][459][460][461][462][463][464][465][466][467]. Wnt proteins that can involve Wnt1 oversee programmed cell death [105,219,278,299,339,362,387,[467][468][469][470][471][472], pancreatic β-cell development and growth [473], skeletal function [152,305,307], trophic factor protec...…”