Talin 2 concentrations in cerebrospinal fluid in patients with epilepsy

Common Pathways of Epileptogenesis in Patients With Epilepsy Post-Brain Injury: Findings From a Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Epilepsy may result from various brain injuries, including stroke (ischemic and hemorrhagic), traumatic brain injury, and infections. Identifying shared common biological pathways and biomarkers of the epileptogenic process initiated by the different injuries may lead to novel targets for preventing the development of epilepsy. We systematically reviewed biofluid biomarkers to test their association with the risk of post-brain injury epilepsy.

METHODS

We searched articles until January 25, 2022, in MEDLINE, Embase, PsycInfo, Web of Science, and Cochrane. The primary outcome was the difference in mean biomarker levels in patients with and without post-brain injury epilepsy. We used the modified quality score on prognostic studies for risk of bias assessment. We calculated each biomarker's pooled standardized mean difference (SMD) and 95% CI. Molecular interaction network and enrichment analyses were conducted in Cytoscape (PROSPERO CRD42021297110).

RESULTS

We included 22 studies with 1,499 cases with post-brain injury epilepsy and 7,929 controls without post-brain injury epilepsy. Forty-five biomarkers in the blood or CSF were investigated with samples collected at disparate time points. Of 22 studies, 21 had a moderate-to-high risk of bias. Most of the biomarkers (28/45) were investigated in single studies; only 9 provided validation data, and studies used variable definitions for early-onset and late-onset seizures. A meta-analysis was possible for 19 biomarkers. Blood glucose levels in 4 studies were significantly higher in patients with poststroke epilepsy (PSE) than those without PSE (SMD 0.44; CI 0.19-0.69). From individual studies, 15 biomarkers in the blood and 7 in the CSF were significantly associated with post-brain injury epilepsy. Enrichment analysis identified that the significant biomarkers (interleukin [IL]-6, IL-1β]) were predominantly inflammation related.

DISCUSSION

We cannot yet recommend using the reported biomarkers for designing antiepileptogenesis trials or use in the clinical setting because of methodological heterogeneity, bias in the included studies, and insufficient validation studies. Although our analyses indicate the plausible role of inflammation in epileptogenesis, this is likely not the only mechanism. For example, an individual's genetic susceptibilities might contribute to his/her risk of epileptogenesis after brain injury. Rigorously designed biomarker studies with methods acceptable to the regulatory bodies should be conducted.

Serum agrin and talin are increased in major depression while agrin and creatine phosphokinase are associated with chronic fatigue and fibromyalgia symptoms in depression

Chronic fatigue and fibromyalgia symptoms frequently occur in major depressive disorder (MDD). The pathophysiology of these symptoms may in part, be ascribed to activated immune pathways, although it is unclear whether muscular factors play a role in their onset. The aim of the present study is to examine the role of muscle proteins in major depression in association with symptoms of chronic fatigue and fibromyalgia. We measured serum levels of agrin, talin-2, titin, and creatine phosphokinase (CPK) as well as the FibroFatigue (FF), the Hamilton Depression Rating Scale (HAM-D) and the Beck Depression Inventory (BDI-II) scores in 60 MDD patients and 30 healthy controls. The results show a significant increase in agrin and talin-2 in MDD patients as compared with controls. There were highly significant correlations between agrin and HAM-D, BDI-II and FF scores. Agrin, but not talin or titin, was significantly and positively associated with all 12 items of the FF scale. We found that a large part of the variance in HAM-D (47.4%), BDI-II (43.4%) and FF (43.5%) scores was explained by the regression on agrin, smoking, female sex (positively associated) and education (inversely associated). CPK was significantly and inversely associated with the total FF score and with muscle and gastro-intestinal symptoms, fatigue, a flu-like malaise, headache and memory, autonomic and sleep disturbances. These results suggest that aberrations in neuromuscular (NMJs) and myotendinous junctions play a role in MDD and that the aberrations in NMJs coupled with lowered CPK may play a role in chronic fatigue and fibromyalgia symptoms in MDD. Moreover, the increase of agrin in MDD probably functions as part of the compensatory immune-regulatory system (CIRS).

Matrix metalloproteinase-9-dependent mechanisms of reduced contractility and increased stiffness in the aging heart

PURPOSE

Matrix metalloproteinases (MMPs) collectively degrade all extracellular matrix (ECM) proteins. Of the MMPs, MMP-9 has the strongest link to the development of cardiac dysfunction. Aging associates with increased MMP-9 expression in the left ventricle (LV) and reduced cardiac function. We investigated the effect of MMP-9 deletion on the cardiac ECM in aged animals.

EXPERIMENTAL DESIGN

We used male and female middle-aged (10- to16-month old) and old (20- to 24-month old) wild-type (WT) and MMP-9 null mice (n = 6/genotype/age). LVs were decellularized to remove highly abundant mitochondrial proteins that could mask identification of relative lower abundant components, analyzed by shotgun proteomics, and proteins of interest validated by immunoblot.

RESULTS

Elastin microfibril interface-located protein 1 (EMILIN-1) decreased with age in WT (p < 0.05), but not in MMP-9 null. EMILIN-1 promotes integrin-dependent cell adhesion and EMILIN-1 deficiency has been associated with vascular stiffening. Talin-2, a cytoskeletal protein, was elevated with age in WT (p < 0.05), and MMP-9 deficiency blunted this increase. Talin-2 is highly expressed in adult cardiac myocytes, transduces mechanical force to the ECM, and is activated by increases in substrate stiffness. Our results suggest that MMP-9 deletion may reduce age-related myocardial stiffness, which may explain improved cardiac function in MMP-9 null animals.

CONCLUSIONS

We identified age-related changes in the cardiac proteome that are MMP-9 dependent, suggesting MMP-9 as a possible therapeutic target for the aging patient.

Molecular biomarkers of epileptogenesis

The heterogeneity of epilepsy syndromes and pathologies creates a great challenge for the search for biomarkers. Not surprisingly, identification of a marker that is specific and sensitive for a given epileptogenic pathology remains an unmet need. There have, however, been several studies of major epileptogenic etiologies like traumatic brain injury that aimed to identify molecular markers in blood and cerebrospinal fluid that predict outcome, by using proteomics and metabolomics. Unfortunately, epileptogenesis has not been analyzed as an outcome measure. Another question to be explored is whether a palette of molecular markers is needed, rather than a single molecule, with each marker probing a different component of epileptogenic pathology. Further, perhaps multiple biomarker platforms (e.g., imaging, proteomics, electrophysiology) should be used in combination and/or in a defined temporal sequence.

Role of a neural cell adhesion molecule found in cerebrospinal fluid as a potential biomarker for epilepsy

The neural cell adhesion molecule (NCAM-1) plays an important role in cell adhesion and synaptic plasticity. We designed this study to evaluate NCAM-1 as a potential biomarker for epilepsy. We performed a quantitative evaluation of the levels of NCAM-1 in cerebrospinal fluid (CSF) and serum and noted differences in patients with epilepsy compared to control subjects. We used sandwich enzyme-linked immunosorbent assays to measure NCAM-1 concentrations in CSF and serum samples of 76 epileptic patients (subdivided into the following subgroups: drug-refractory epilepsy, DRE; first-diagnosis epilepsy, FDE; and drug-effective epilepsy, DEE) and 44 control subjects. Our results show that cerebrospinal fluid-NCAM-1 (CSF-NCAM-1) concentrations and NCAM-1 Indices in the epileptic group were lower than in the control group. Both the CSF-NCAM-1 concentration and the NCAM-1 Indices in the drug-refractory epilepsy group were lower than in the drug-effective epilepsy group. These differences were statistically significant (P < 0.05). However, serum-NCAM-1 levels were not statistically different when comparing the epilepsy group to the control group (P > 0.05). Our results indicate that CSF-NCAM-1 is a potential biomarker for drug-effective epilepsy and drug-refractory epilepsy.