Investigation of UCH-L1 levels in ischemic stroke, intracranial hemorrhage and metabolic disorder induced impaired consciousness

Proteinopathies and the Neurodegenerative Aftermath of Stroke: Potential Biomarkers and Treatment Targets

Stroke remains a predominant cause of death and long-term disability among adults worldwide. Emerging evidence suggests that proteinopathies, characterized by the aggregation and accumulation of misfolded proteins, may play a significant role in the aftermath of stroke and the progression of neurodegenerative disorders. In this review, we explore preclinical and clinical research on key proteinopathies associated with stroke, including tau, Aβ (amyloid-β), TDP-43 (TAR DNA-binding protein 43), α-synuclein, and UCH-L1 (ubiquitin C-terminal hydrolase-L1). We focus on their potential as biomarkers for recovery management and as novel treatment targets that may enhance neuronal repair and mitigate secondary neurodegeneration. The involvement of these proteinopathies in various aspects of stroke, including neuroinflammation, oxidative stress, neuronal damage, and vascular dysfunction, underscores their potential. However, further investigations are essential to validate the clinical utility of these biomarkers, elucidate the mechanisms connecting proteinopathies to poststroke neurodegeneration, and develop targeted interventions. Identifying specific protein signatures associated with stroke outcomes could facilitate the advancement of precision medicine tailored to individual patient needs, significantly enhancing the quality of life for stroke survivors.

Can Serum GFAP and UCH-L1 Replace CT in Assessing Acute Ischemic Stroke Severity?

As acute ischemic stroke (AIS) is still a significant cause of morbidity globally, new methods of rapid diagnostics are continually being researched and improved. Still, the only definite way to diagnose AIS is radiological imaging. Lately, serum biomarkers glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) have shown their usefulness in AIS as potential complementary tools in early recognition. We aimed to investigate if GFAP and UCH-L1 can correlate with comprehensive diagnostic information provided by computed tomography (CT) and several clinical parameters in AIS severity assessment and subsequently with clinical outcomes. Fifty-two patients with AIS and a potential for mechanical thrombectomy (MT) were included in our study. Thirty-seven patients underwent MT. Results showed no correlation of biomarkers with any analyzed CT parameter (thrombus length, volume, and density, clot burden score, collateral score, AIS core and penumbra volume, differences in perfusion between healthy and affected brain tissue). In addition, none of the clinical parameters, such as sex, symptom onset time, or the National Institutes of Health Stroke Scale, correlated with biomarkers. However, lower biomarker levels corresponded with a good clinical outcome, and higher levels to a poor outcome following hospital discharge, irrespective of the performed MT (p = 0.005 for GFAP, p = 0.001 for UCH-L1). In patients with successful MT, there were also differences between patients with a good clinical outcome compared with patients with a poor clinical outcome (p = 0.007 for GFAP, p = 0.004 for UCH-L1). In conclusion, these biomarkers cannot replace imaging modalities but can provide complementary diagnostic information in the setting of AIS.

Modified human mesenchymal stromal/stem cells restore cortical excitability after focal ischemic stroke in rats

Allogeneic modified bone marrow-derived human mesenchymal stromal/stem cells (hMSC-SB623 cells) are in clinical development for the treatment of chronic motor deficits after traumatic brain injury and cerebral ischemic stroke. However, their exact mechanisms of action remain unclear. Here, we investigated the effects of this cell therapy on cortical network excitability, brain tissue, and peripheral blood at a chronic stage after ischemic stroke in a rat model. One month after focal cortical ischemic stroke, hMSC-SB623 cells or the vehicle solution were injected into the peri-stroke cortex. Starting one week after treatment, cortical excitability was assessed ex vivo. hMSC-SB623 cell transplants reduced stroke-induced cortical hyperexcitability, restoring cortical excitability to control levels. The histology of brain tissue revealed an increase of factors relevant to neuroregeneration, and synaptic and cellular plasticity. Whole-blood RNA sequencing and serum protein analyses showed that intra-cortical hMSC-SB623 cell transplantation reversed effects of stroke on peripheral blood factors known to be involved in stroke pathophysiology. Our findings demonstrate that intra-cortical transplants of hMSC-SB623 cells correct stroke-induced circuit disruptions even at the chronic stage, suggesting broad usefulness as a therapeutic for neurological conditions with network hyperexcitability. Additionally, the transplanted cells exert far-reaching immunomodulatory effects whose therapeutic impact remains to be explored.

Serum GFAP and UCH-L1 Levels for the Assessment of the Absence of Hemorrhagic Transformation: A Multicenter Prospective Cohort Study

BACKGROUND

Currently, validated biomarkers for assessing hemorrhagic transformation (HT) after intravenous thrombolysis (IVT) are lacking. We aimed to validate a test combining GFAP (glial fibrillary acidic protein) and UCH-L1 (ubiquitin C-terminal hydrolase-L1) to indicate the absence of HT after IVT.

METHODS

We prospectively enrolled consecutive patients with stroke treated with IVT from 16 hospitals. Serum GFAP and UCH-L1 levels were measured 24 hours after IVT. Cases from 1 hospital were randomly assigned to the training (70%) and testing (30%) cohorts for internal validation. The external validation cohort included patients from the other 15 hospitals. Cutoff levels of GFAP and UCH-L1 for assessing the absence of HT were established in the training cohort and subjected to internal and external verification.

RESULTS

A total of 1063 patients were included. Both GFAP and UCH-L1 levels were independently associated with HT, infarct volume, and 3-month outcome; levels lower than cutoff (12.6 and 63.1 pg/mL, respectively) excluded patients with HT with a negative predictive value of 98.31% (95% CI, 89.70%-99.91%) and detection sensitivity of 98.08% (95% CI, 88.42%-99.90%) in the training cohort. In the testing and validation cohorts, negative predictive value was 100% (95% CI, 75.93%-100%) and 100% (95% CI, 82.19%-100%), respectively, and the sensitivity was 100% (95% CI, 80.76%-100%) and 100% (95% CI, 77.08%-100%), respectively.

CONCLUSIONS

Serum GFAP and UCH-L1 levels exhibit high sensitivity and negative predictive value for indicating the absence of HT 24 hours after IVT, which supports their potential role in assessing patients' condition after IVT.

Blood and cerebrospinal fluid biomarkers in disorders of consciousness

The study of blood and cerebrospinal fluid biomarkers is a promising and rapidly advancing field in the research of disorders of consciousness (DoC). The use of advanced biochemical and analytic techniques in biomarker research has improved our ability to identify new biomarkers that can aid in the diagnosis, prognosis, and treatment of patients with brain injury. However, the use of biomarkers in clinical practice is limited by several challenges, including the lack of standardization in test and research methodologies. Despite this, identifying the most promising biomarkers and supporting their findings with strong evidence can improve their clinical utility. This chapter discusses the most promising biomarkers for DoC, which fall into four categories: neuronal, glial, inflammatory, and metabolic biomarkers. Understanding the role of each category in DoC can provide valuable insights into the mechanisms of brain injury and inform the development of more effective diagnostic and treatment strategies. By integrating biomarker research with clinical practice, we can improve our understanding of DoC and provide better care for these patients.

Blood-Based Biomarkers for Neuroprognostication in Acute Brain Injury

Acute brain injury causes loss of functionality in patients that often is devastating. Predicting the degree of functional loss and overall prognosis requires a multifaceted approach to help patients, and more so their families, make important decisions regarding plans and goals of care. A variety of blood-based markers have been studied as one aspect of this determination. In this review, we discuss CNS-derived and systemic markers that have been studied for neuroprognostication purposes. We discuss the foundation of each protein, the conditions in which it has been studied, and how the literature has used these markers for interpretation. We also discuss challenges to using each marker in each section as well.