Traumatic brain injury (TBI) is a leading cause of mortality, sensorimotor morbidity, and neurocognitive disability. Neuroinflammation is one of the key drivers causing secondary brain injury after... Show moreTraumatic brain injury (TBI) is a leading cause of mortality, sensorimotor morbidity, and neurocognitive disability. Neuroinflammation is one of the key drivers causing secondary brain injury after TBI. Therefore, attenuation of the inflammatory response is a potential therapeutic goal. This review summarizes the most important neuroinflammatory pathophysiology resulting from TBI and the clinical trials performed to attenuate neuroinflammation. Studies show that non-selective attenuation of the inflammatory response, in the early phase after TBI, might be detrimental and that there is a gap in the literature regarding pharmacological trials targeting specific pathways. The complement system and its crosstalk with the coagulation system play an important role in the pathophysiology of secondary brain injury after TBI. Therefore, regaining control over the complement cascades by inhibiting overshooting activation might constitute useful therapy. Activation of the complement cascade is an early component of neuroinflammation, making it a potential target to mitigate neuroinflammation in TBI. Therefore, we have described pathophysiological aspects of complement inhibition and summarized animal studies targeting the complement system in TBI. We also present the first clinical trial aimed at inhibition of complement activation in the early days after brain injury to reduce the risk of morbidity and mortality following severe TBI. Show less
Marco, R. de; Ronen, I.; Branzoli, F.; Amato, M.L.; Asllani, I.; Colasanti, A.; ... ; Cercignani, M. 2022
Background: Low-dose lipopolysaccharide (LPS) is a well-established experimental method for inducing systemic inflammation and shown by microscopy to activate microglia in rodents. Currently,... Show moreBackground: Low-dose lipopolysaccharide (LPS) is a well-established experimental method for inducing systemic inflammation and shown by microscopy to activate microglia in rodents. Currently, techniques for in-vivo imaging of glia in humans are limited to TSPO (Translocator protein) PET, which is expensive, methodologically challenging, and has poor cellular specificity. Diffusion-weighted magnetic resonance spectroscopy (DW-MRS) sensitizes MR spectra to diffusion of intracellular metabolites, potentially providing cell-specific information about cellular morphology. In this preliminary study, we applied DW-MRS to measure changes in the apparent diffusion coefficients (ADC) of glial and neuronal metabolites to healthy participants who underwent an LPS administration protocol. We hypothesized that the ADC of glial metabolites will be selectively modulated by LPSinduced glial activation. Methods: Seven healthy male volunteers, (mean 25.3 +/- 5.9 years) were each tested in two separate sessions once after LPS (1 ng/Kg intravenously) and once after placebo (saline). Physiological responses were monitored during each session and serial blood samples and Profile of Mood States (POMS) completed to quantify white blood cell (WBC), cytokine and mood responses. DW-MRS data were acquired 5-51/2 hours after injection from two brain regions: grey matter in the left thalamus, and frontal white matter. Results: Body temperature, heart rate, WBC and inflammatory cytokines were significantly higher in the LPS compared to the placebo condition (p < 0.001). The ADC of the glial metabolite choline (tCho) was also significantly increased after LPS administration compared to placebo (p = 0.008) in the thalamus which scaled with LPS-induced changes in POMS total and negative mood (Adj R-2 = 0.83; p = 0.004). Conclusions: DW-MRS may be a powerful new tool sensitive to glial cytomorphological changes in grey matter induced by systemic inflammation. Show less
Background: Traumatic brain injury (TBI) is a major cause of death and disability across all ages. After the primary impact, the pathophysiologic process of secondary brain injury consists of a... Show moreBackground: Traumatic brain injury (TBI) is a major cause of death and disability across all ages. After the primary impact, the pathophysiologic process of secondary brain injury consists of a neuroinflammation response that critically leads to irreversible brain damage in the first days after the trauma. A key catalyst in this inflammatory process is the complement system. Inhibiting the complement system could therefore be a therapeutic target in TBI.Objective: To study the safety and efficacy of C1-inhibitor (C1-INH) compared to placebo in patients with TBI. By temporarily blocking the complement system, we hypothesize a decrease in the posttraumatic neuroinflammatory response resulting in a less unfavorable clinical outcome for TBI patients.Methods: CIAO@TBI is a multicenter, randomized, blinded, phase II placebo-controlled trial. Adult TBI patients with GCS < 13 requiring intracranial pressure (ICP) monitoring will be randomized, using block randomization, within 12 h after trauma to one dose 6000 IU C1-INH or placebo. A total of 106 patients will be included, and follow-up will occur up to 12 months. The primary endpoints are (1) Therapy Intensity Level (TIL) Scale, (2) Glasgow Outcome Scale-Extended (GOSE) at 6 months, and (3) complication rate during hospitalization. Outcomes will be determined by a trial nurse blinded for the treatment allocation. Analyses will be conducted in an intention-to-treat analysis.Discussion: We expect that C1-INH administration will be safe and potentially effective to improve clinical outcomes by reducing neuroinflammation in TBI patients. Show less
Kursun, O.; Yemisci, M.; Maagdenberg, A.M.J.M. van den; Karatas, H. 2021
Background Neuroinflammation has an important role in the pathophysiology of migraine, which is a complex neuro-glio-vascular disorder. The main aim of this review is to highlight findings of... Show moreBackground Neuroinflammation has an important role in the pathophysiology of migraine, which is a complex neuro-glio-vascular disorder. The main aim of this review is to highlight findings of cortical spreading depolarization (CSD)-induced neuroinflammatory signaling in brain parenchyma from the inflammasome perspective. In addition, we discuss the limited data of the contribution of inflammasomes to other aspects of migraine pathophysiology, foremost the activation of the trigeminovascular system and thereby the generation of migraine pain. Main body Inflammasomes are signaling multiprotein complexes and key components of the innate immune system. Their activation causes the production of inflammatory cytokines that can stimulate trigeminal neurons and are thus relevant to the generation of migraine pain. The contribution of inflammasome activation to pain signaling has attracted considerable attention in recent years. Nucleotide-binding domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) is the best characterized inflammasome and there is emerging evidence of its role in a variety of inflammatory pain conditions, including migraine. In this review, we discuss, from an inflammasome point of view, cortical spreading depolarization (CSD)-induced neuroinflammatory signaling in brain parenchyma, the connection with genetic factors that make the brain vulnerable to CSD, and the relation of the inflammasome with diseases that are co-morbid with migraine, including stroke, epilepsy, and the possible links with COVID-19 infection. Conclusion Neuroinflammatory pathways, specifically those involving inflammasome proteins, seem promising candidates as treatment targets, and perhaps even biomarkers, in migraine. Show less
This thesis aimed to gain more insight into the role of iron in neurodegenerative diseases using high-field MRI. I investigated the pathological correlates of susceptibility-based contrasts on MRI,... Show moreThis thesis aimed to gain more insight into the role of iron in neurodegenerative diseases using high-field MRI. I investigated the pathological correlates of susceptibility-based contrasts on MRI, and how iron accumulation is associated with disease progression both ex vivo and in vivo. Show less
Bulk, M.; Harten, T. van; Kenkhuis, B.; Inglese, F.; Hegeman, I.; Duinen, S. van; ... ; Ronen, I. 2021
Systemic lupus erythematosus (SLE) is an auto-immune disease characterized by multi-organ involvement. Although uncommon, central nervous system involvement in SLE, termed neuropsychiatric SLE ... Show moreSystemic lupus erythematosus (SLE) is an auto-immune disease characterized by multi-organ involvement. Although uncommon, central nervous system involvement in SLE, termed neuropsychiatric SLE (NPSLE), is not an exception. Current knowledge on underlying pathogenic mechanisms is incomplete, however, neuroinflammation is thought to play a critical role. Evidence from neurodegenerative diseases and multiple sclerosis suggests that neuroinflammation is correlated with brain iron accumulation, making quantitative susceptibility mapping (QSM) a potential hallmark for neuroinflammation in vivo. This study assessed susceptibility values of the thalamus and basal ganglia in (NP)SLE patients and further investigated the in vivo findings with histological analyses of postmortem brain tissue derived from SLE patients. We used a 3T MRI scanner to acquire single-echo T2*-weighted images of 44 SLE patients and 20 age-matched healthy controls. Of the 44 patients with SLE, all had neuropsychiatric complaints, of which 29 were classified as non-NPSLE and 15 as NPSLE (seven as inflammatory NPSLE and eight as ischemic NPSLE). Mean susceptibility values of the thalamus, caudate nucleus, putamen, and globus pallidus were calculated. Formalin-fixed paraffin-embedded post-mortem brain tissue including the putamen and globus pallidus of three additional SLE patients was obtained and stained for iron, microglia and astrocytes. Susceptibility values of SLE patients and age-matched controls showed that iron levels in the thalamus and basal ganglia were not changed due to the disease. No subgroup of SLE showed higher susceptibility values. No correlation was found with disease activity or damage due to SLE. Histological examination of the post-mortem brain showed no increased iron accumulation. Our results suggest that neuroinflammation in NPSLE does not necessarily go hand in hand with iron accumulation, and that the inflammatory pathomechanism in SLE may differ from the one observed in neurodegenerative diseases and in multiple sclerosis. Show less
Boon, B.D.C.; Bulk, M.; Jonker, A.J.; Morrema, T.H.J.; Berg, E. van den; Popovic, M.; ... ; Hoozemans, J.J.M. 2020
Alzheimer's disease (AD) is characterized by amyloid-beta (A beta) deposits, which come in myriad morphologies with varying clinical relevance. Previously, we observed an atypical A beta deposit,... Show moreAlzheimer's disease (AD) is characterized by amyloid-beta (A beta) deposits, which come in myriad morphologies with varying clinical relevance. Previously, we observed an atypical A beta deposit, referred to as the coarse-grained plaque. In this study, we evaluate the plaque's association with clinical disease and perform in-depth immunohistochemical and morphological characterization. The coarse-grained plaque, a relatively large (o approximate to 80 mu m) deposit, characterized as having multiple cores and A beta-devoid pores, was prominent in the neocortex. The plaque was semi-quantitatively scored in the middle frontal gyrus of A beta-positive cases (n = 74), including non-demented cases (n = 15), early-onset (EO)AD (n = 38), and late-onset (LO)AD cases (n = 21). The coarse-grained plaque was only observed in cases with clinical dementia and more frequently present in EOAD compared to LOAD. This plaque was associated with a homozygousAPOE epsilon 4 status and cerebral amyloid angiopathy (CAA). In-depth characterization was done by studying the coarse-grained plaque's neuritic component (pTau, APP, PrP (c)), A beta isoform composition (A beta(40), A beta(42), A beta(N3pE), pSer8A beta), its neuroinflammatory component (C4b, CD68, MHC-II, GFAP), and its vascular attribution (laminin, collagen IV, norrin). The plaque was compared to the classic cored plaque, cotton wool plaque, and CAA. Similar to CAA but different from classic cored plaques, the coarse-grained plaque was predominantly composed of A beta(40). Furthermore, the coarse-grained plaque was distinctly associated with both intense neuroinflammation and vascular (capillary) pathology. Confocal laser scanning microscopy (CLSM) and 3D analysis revealed for most coarse-grained plaques a particular A beta(40)shell structure and a direct relation with vessels. Based on its morphological and biochemical characteristics, we conclude that the coarse-grained plaque is a divergent A beta plaque-type associated with EOAD. Differences in A beta processing and aggregation, neuroinflammatory response, and vascular clearance may presumably underlie the difference between coarse-grained plaques and other A beta deposits. Disentangling specific A beta deposits between AD subgroups may be important in the search for disease-mechanistic-based therapies. Show less
Meyer, M.; Kruse, M.S.; Garay, L.; Lima, A.; Roig, P.; Hunt, H.; ... ; Nicola, A.F. de 2020
The Wobbler mouse spinal cord shows vacuolated motoneurons, glial reaction, inflammation and abnormal glutamatergic parameters. Wobblers also show deficits of motor performance. These conditions... Show moreThe Wobbler mouse spinal cord shows vacuolated motoneurons, glial reaction, inflammation and abnormal glutamatergic parameters. Wobblers also show deficits of motor performance. These conditions resemble amyotrophic lateral sclerosis (ALS). Wobbler mice also show high levels of corticosterone in blood, adrenals and brain plus adrenal hypertrophy, suggesting that chronically elevated glucocorticoids prime spinal cord neuroinflammation. Therefore, we analyzed if treatment of Wobbler mice with the glucocorticoid receptor (GR) antagonist CORT113176 mitigated the mentioned abnormalities. 30 mg/kg CORT113176 given daily for 3 weeks reduced motoneuron vacuolation, decreased astro and microgliosis, lowered the inflammatory mediators high mobility group box 1 protein (HMGB1), toll-like receptor 4, myeloid differentiation primary response 88 (MyD88), p50 subunit of nuclear factor kappa B (NF kappa B), tumor necrosis factor (TNF) receptor, and interleukin 18 (IL18) compared to untreated Wobblers. CORT113176 increased the survival signal pAKT (serine-threonine kinase) and decreased the death signal phosphorylated Junk-N-terminal kinase (pJNK), symptomatic of antiapoptosis. There was a moderate positive effect on glutamine synthase and astrocyte glutamate transporters, suggesting decreased glutamate excitotoxicity. In this pre-clinical study, Wobblers receiving CORT113176 showed enhanced resistance to fatigue in the rota rod test and lower forelimb atrophy at weeks 2-3. Therefore, long-term treatment with CORT113176 attenuated degeneration and inflammation, increased motor performance and decreased paw deformity. Antagonism of the GR may be of potential therapeutic value for neurodegenerative diseases. Show less
Westhoff, D.; Engelen-Lee, J.Y.; Hoogland, I.C.M.; Aronica, E.M.A.; Westerloo, D.J. van; Beek, D. van de; Gool, W.A. van 2019
Worldwide, raised blood pressure is estimated to affect 35-40% of the adult population and is a main conditioning factor for cardiovascular diseases and stroke. Animal models of hypertension have... Show moreWorldwide, raised blood pressure is estimated to affect 35-40% of the adult population and is a main conditioning factor for cardiovascular diseases and stroke. Animal models of hypertension have provided great advances concerning the pathophysiology of human hypertension, as already shown for the deoxycorticosterone-salt treated rat, the Dahl-salt sensitive rat, the Zucker obese rat and the spontaneously hypertensive rat (SHR). SHR has been widely used to study abnormalities of the brain in chronic hypertension. This review summarises present and past evidence that in the SHR, hypertension causes hippocampal tissue damage which triggers a pro-inflammatory feedforward cascade affecting this vulnerable brain region. The cascade is driven by mineralocorticoid receptor (MR) activation responding to endogenous corticosterone rather than aldosterone. Increased MR expression is a generalised feature of the SHR which seems to support first the rise in blood pressure. Then oxidative stress caused by vasculopathy and hypoxia further increases MR activation in hippocampal neurons and glia cells, activates microglia activation and pro-inflammatory mediators, and down-regulates anti-inflammatory factors. In contrast to MR, involvement of the glucocorticoid receptor (GR) in SHR is less certain. GR showed normal expression levels and blockage with an antagonist failed to reduce blood pressure of SHR. The findings support the concept that MR:GR imbalance caused by vasculopathy causes a switch in MR function towards a proverbial "death" receptor. Show less
Taj, S.H.; Blon, D. le; Hoornaert, C.; Daans, J.; Quarta, A.; Praet, J.; ... ; Hoehn, M. 2018
This Thesis reports on the discovery and optimization of potent inhibitors for the serine hydrolases sn-1 diacylglycerol lipase α (DAGLα) and α/β hydrolase domain 16A (ABHD16A). Several... Show more This Thesis reports on the discovery and optimization of potent inhibitors for the serine hydrolases sn-1 diacylglycerol lipase α (DAGLα) and α/β hydrolase domain 16A (ABHD16A). Several structure- and ligand-based drug discovery methodologies were employed, such as in silico screening and high throughput screening, in combination with activity-based protein profiling (ABPP). The glycine sulfonamides reported in this Thesis, such as LEI106, are important peripherally restricted inhibitors that can be used to evaluate the contribution of perturbing DAGL activity in the potential treatment of metabolic syndrome, diabetes and pheriphiral obesity. The α-keto heterocycles in this Thesis, such as LEI107, could be important inhibitors to evaluate if a therapeutic window can be established for (central) DAGL inhibitors in the potential treatment of addiction, obesity and neuroinflammation. Lastly, 1,2,4-triazole urea sulfonamides that are reported in this Thesis can be used as novel tool compounds to evaluate DAGL and ABHD16A function in both health and disease. Show less