Ubiquitin Carboxyl-terminal Hydrolase L1 Research Articles

Evaluation of GFAP/UCH-L1 biomarkers for computed tomography exclusion in mild traumatic brain injury (mTBI)

IntroductionMild traumatic brain injury (mTBI) represents a major public health concern and affects millions of people worldwide every year. Diagnosis mainly relies on clinical criteria and computed tomography (CT) scans. GFAP (glial fibrillary acidic protein) and UCH-L1 (ubiquitin carboxyl-terminal hydrolase-L1) have been recently studied as potential biomarkers of mTBI. This study retrospectively evaluated the possible use of these combined biomarkers as negative predictors for excluding brain injuries in patients with suspected mTBI in the emergency department.MethodsAdult patients (n = 130) enrolled at Tor Vergata University Hospital (Rome, Italy), consecutively registered at the triage of the emergency department between October 2022 and January 2023, with non-penetrating TBI and Glasgow Coma Scale (GCS) score of 13–15, were considered. All eligible patients underwent intracranial CT scans and blood tests, within 12 h after trauma, for GFAP and UCH-L1 serum concentrations.ResultsIntracranial CT detected injuries in only seven patients (5%); GFAP and UCH-L1 tested positive in 96 patients and negative in 34 patients (74% vs. 26%). Combined biomarkers had a sensitivity equal to 1.00 (95% CI 0.64-1.00) and a negative predictive value (NPV) of 1.00 (0.99-1.00) in mTBI diagnosis with a negative CT.ConclusionsCombined laboratory tests for GFAP and UCH-L1 biomarkers might play a potential clinical role in avoiding unnecessary head CT scans after mTBI in emergency departments.

Distinct Serum Glial Fibrillary Acidic Protein and Neurofilament Light Time-Courses After Rapid Head Rotations.

Traumatic brain injury (TBI) causes significant neurophysiological deficits and is typically associated with rapid head accelerations common in sports-related incidents and automobile accidents. There are over 1.5 million TBIs in the United States each year, with children aged 0-4 being particularly vulnerable. TBI diagnosis is currently achieved through interpretation of clinical signs and symptoms and neuroimaging; however, there is increasing interest in minimally invasive fluid biomarkers to detect TBI objectively across all ages. Pre-clinical porcine models offer controlled conditions to evaluate TBI with known biomechanical conditions and without comorbidities. The objective of the current study was to establish pediatric porcine healthy reference ranges (RRs) of common human serum TBI biomarkers and to report their acute time-course after nonimpact rotational head injury. A retrospective analysis was completed to quantify biomarker concentrations in porcine serum samples collected from 4-week-old female (n = 215) and uncastrated male (n = 6) Yorkshire piglets. Subjects were assigned to one of three experimental groups (sham, sagittal-single, sagittal-multiple) or to a baseline only group. A rapid nonimpact rotational head injury model was used to produce mild-to-moderate TBI in piglets following a single rotation and moderate-to-severe TBI following multiple rotations. The Quanterix Simoa Human Neurology 4-Plex A assay was used to quantify glial fibrillary acidic protein (GFAP), neurofilament light (Nf-L), tau, and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1). The 95% healthy RRs for females were calculated and validated for GFAP (6.3-69.4 pg/mL), Nf-L (9.5-67.2 pg/mL), and UCH-L1 (3.8-533.7 pg/mL). Rising early, GFAP increased significantly above the healthy RRs for sagittal-single (to 164 and 243 pg/mL) and increased significantly higher in sagittal-multiple (to 494 and 413 pg/mL) groups at 30 min and 1 h postinjury, respectively, returning to healthy RRs by 1-week postinjury. Rising later, Nf-L increased significantly above the healthy RRs by 1 day in sagittal-single (to 69 pg/mL) and sagittal-multiple groups (to 140 pg/mL) and rising further at 1 week (single = 231 pg/mL, multiple = 481 pg/mL). Sagittal-single and sagittal-multiple UCH-L1 serum samples did not differ from shams or the healthy RRs. Sex differences were observed but inconsistent. Serum GFAP and Nf-L levels had distinct time-courses following head rotations in piglets, and both corresponded to load exposure. We conclude that serum GFAP and Nf-L offer promise for early TBI diagnosis and intervention decisions for TBI and other neurological trauma.

Association of Biomarkers of Neuronal Injury and Inflammation With Insomnia Trajectories After Traumatic Brain Injury: A TRACK-TBI Study.

Insomnia affects about one-third of patients with traumatic brain injury and is associated with worsened outcomes after injury. We hypothesized that higher levels of plasma neuroinflammation biomarkers at the time of TBI would be associated with worse 12-month insomnia trajectories. Participants were prospectively enrolled from 18 level-1 trauma centers participating in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study from February 26, 2014, to August 8, 2018. Plasma glial fibrillary acidic protein (GFAP), high-sensitivity C-reactive protein (hsCRP), S100b, neuron-specific enolase (NSE), and ubiquitin carboxyl-terminal hydrolase-L1 (UCH-L1) were collected on days 1 (D1) and 14 (D14) after TBI. The insomnia severity index was collected at 2 weeks, 3, 6, and 12 months postinjury. Participants were classified into insomnia trajectory classes based on a latent class model. We assessed the association of biomarkers with insomnia trajectories, controlling for medical and psychological comorbidities and demographics. Two thousand twenty-two individuals with TBI were studied. Elevations in D1 hsCRP were associated with persistent insomnia (severe, odds ratio [OR] = 1.33 [1.11, 1.59], p = 0.002; mild, OR = 1.10 [1.02, 1.19], p = 0.011). Similarly, D14 hsCRP elevations were associated with persistent insomnia (severe, OR = 1.27 [1.02, 1.59], p = 0.03). Of interest, D1 GFAP was lower in persistent severe insomnia (median [Q1, Q3]: 154 [19, 445] pg/mL) compared with resolving mild (491 [154, 1,423], p < 0.001) and persistent mild (344 [79, 1,287], p < 0.001). D14 GFAP was similarly lower in persistent (11.8 [6.4, 19.4], p = 0.001) and resolving (13.9 [10.3, 20.7], p = 0.011) severe insomnia compared with resolving mild (20.6 [12.4, 39.6]. Accordingly, increases in D1 GFAP were associated with reduced likelihood of having persistent severe (OR = 0.76 [95% CI 0.63-0.92], p = 0.004) and persistent mild (OR = 0.88 [0.81, 0.96], p = 0.003) compared with mild resolving insomnia. No differences were found with other biomarkers. Elevated plasma hsCRP and, surprisingly, lower GFAP were associated with adverse insomnia trajectories after TBI. Results support future prospective studies to examine their utility in guiding insomnia care after TBI. Further work is needed to explore potential mechanistic connections between GFAP levels and the adverse insomnia trajectories.

Diagnostic Utility of Glial Fibrillary Acidic Protein Beyond 12 Hours After Traumatic Brain Injury: A TRACK-TBI Study.

Blood levels of glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase-L1 (UCH-L1) within 12h of suspected traumatic brain injury (TBI) have been approved by the Food and Drug administration to aid in determining the need for a brain computed tomography (CT) scan. The current study aimed to determine whether this context of use can be expanded beyond 12h post-TBI in patients presenting with Glasgow Coma Scale (GCS) 13-15. The prospective, 18-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study enrolled TBI participants aged ≥17 years who presented to a United States Level 1 trauma center and received a clinically indicated brain CT scan within 24h post-injury, a blood draw within 24h and at 14 days for biomarker analysis. Data from participants with emergency department arrival GCS 13-15 and biomarker values at days 1 and 14 were extracted for the primary analysis. A subgroup of hospitalized participants with serial biomarkers at days 1, 3, 5, and 14 were analyzed, including plasma GFAP and UCH-L1, and serum neuron-specific enolase (NSE) and S100 calcium-binding protein B (S100B). The primary analysis compared biomarker values dichotomized by head CT results (CT+/CT-). Area under receiver-operating characteristic curve (AUC) was used to determine diagnostic accuracy. The overall cohort included 1142 participants with initial GCS 13-15, with mean age 39.8 years, 65% male, and 73% Caucasian. The GFAP provided good discrimination in the overall cohort at days 1 (AUC = 0.82) and 14 (AUC = 0.72), and in the hospitalized subgroup at days 1 (AUC = 0.84), 3 (AUC = 0.88), 5 (AUC = 0.82), and 14 (AUC = 0.74). The UCH-L1, NSE, and S100B did not perform well (AUC = 0.51-0.57 across time points). This study demonstrates the utility of GFAP to aid in decision-making for diagnostic brain CT imaging beyond the 12h time frame in patients with TBI who have a GCS 13-15.

Ubiquitin Carboxyl-Terminal Hydrolase L1 and Its Role in Parkinson's Disease.

Ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), also known as Parkinson's disease protein 5, is a highly expressed protein in the brain. It plays an important role in the ubiquitin-proteasome system (UPS), where it acts as a deubiquitinase (DUB) enzyme. Being the smallest member of the UCH family of DUBs, it catalyzes the reaction of ubiquitin precursor processing and the cleavage of ubiquitinated protein remnants, thus maintaining the level of ubiquitin monomers in the brain cells. UCHL1 mutants, containing amino acid substitutions, influence catalytic activity and its aggregability. Some of them protect cells and transgenic mice in toxin-induced Parkinson's disease (PD) models. Studies of putative protein partners of UCHL1 revealed about sixty individual proteins located in all major compartments of the cell: nucleus, cytoplasm, endoplasmic reticulum, plasma membrane, mitochondria, and peroxisomes. These include proteins related to the development of PD, such as alpha-synuclein, amyloid-beta precursor protein, ubiquitin-protein ligase parkin, and heat shock proteins. In the context of the catalytic paradigm, the importance of these interactions is not clear. However, there is increasing understanding that UCHL1 exhibits various effects in a catalytically independent manner through protein-protein interactions. Since this protein represents up to 5% of the soluble protein in the brain, PD-related changes in its structure will have profound effects on the proteomes/interactomes in which it is involved. Growing evidence is accumulating that the role of UCHL1 in PD is obviously determined by a balance of canonic catalytic activity and numerous activity-independent protein-protein interactions, which still need better characterization.

Serum biomarkers and disease progression in CT-negative mild traumatic brain injury.

Blood proteins are emerging as potential biomarkers for mild traumatic brain injury (mTBI). Molecular pathology of mTBI underscores the critical roles of neuronal injury, neuroinflammation, and vascular health in disease progression. However, the temporal profile of blood biomarkers associated with the aforementioned molecular pathology after CT-negative mTBI, their diagnostic and prognostic potential, and their utility in monitoring white matter integrity and progressive brain atrophy remain unclear. Thus, we investigated serum biomarkers and neuroimaging in a longitudinal cohort, including 103 CT-negative mTBI patients and 66 matched healthy controls (HCs). Angiogenic biomarker vascular endothelial growth factor (VEGF) exhibited the highest area under the curve of 0.88 in identifying patients from HCs. Inflammatory biomarker interleukin-1β and neuronal cell body injury biomarker ubiquitin carboxyl-terminal hydrolase L1 were elevated in acute-stage patients and associated with deterioration of cognitive function from acute-stage to 6-12mo post-injury period. Notably, axonal injury biomarker neurofilament light (NfL) was elevated in acute-stage patients, with higher levels associated with impaired white matter integrity in acute-stage and progressive gray and white matter atrophy from 3- to 6-12mo post-injury period. Collectively, our findings emphasized the potential clinical value of serum biomarkers, particularly NfL and VEGF, in diagnosing mTBI and monitoring disease progression.

Maximizing the Clinical Value of Blood-Based Biomarkers for Mild Traumatic Brain Injury.

Mild traumatic brain injury (TBI) and concussion can have serious consequences that develop over time with unpredictable levels of recovery. Millions of concussions occur yearly, and a substantial number result in lingering symptoms, loss of productivity, and lower quality of life. The diagnosis may not be made for multiple reasons, including due to patient hesitancy to undergo neuroimaging and inability of imaging to detect minimal damage. Biomarkers could fill this gap, but the time needed to send blood to a laboratory for analysis made this impractical until point-of-care measurement became available. A handheld blood test is now on the market for diagnosis of concussion based on the specific blood biomarkers glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl terminal hydrolase L1 (UCH-L1). This paper discusses rapid blood biomarker assessment for mild TBI and its implications in improving prediction of TBI course, avoiding repeated head trauma, and its potential role in assessing new therapeutic options. Although we focus on the Abbott i-STAT TBI plasma test because it is the first to be FDA-cleared, our discussion applies to any comparable test systems that may become available in the future. The difficulties in changing emergency department protocols to include new technology are addressed.

A-093 Clinical Performance of Biomarkers for Traumatic Brain Injury

Abstract Background An estimated 5 million people are evaluated in emergency departments (ED) for Traumatic Brain Injury (TBI) in the United States each year. The vast majority (80%) of patients evaluated for TBI in the ED will receive head CT scans, however less than 10% of those will have any findings of acute traumatic abnormalities. This highlights the need for objective, rapid, accurate tools to help clinicians evaluate and triage TBI patients and reduce unnecessary radiation exposure. The Alinity i TBI test is a panel of in vitro diagnostic chemiluminescent microparticle immunoassays used to measure glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) in human plasma and serum. TBI performance was evaluated in a multi-center study by performing reproducibility and a pivotal study. Methods A pivotal study using prospectively collected archived (frozen) plasma specimens was conducted to establish the clinical performance of the TBI test on the Alinity i system. The testing of the archived specimens was performed at three clinical sites in the United States. The specimens tested were originally collected in a prospective, multi-center clinical study and were from individuals 18 years of age or older who presented to a health care facility or emergency department with suspected traumatic brain injury. These subjects had an initial Glasgow Coma Scale (GCS) score of 13–15 and had a computed tomography (CT) scan of the head performed per the clinical site’s standard of care. Reproducibility was assessed using multiple panel/control members for 5 days based on guidance from Clinical and Laboratory Standards Institute EP05-A3. Testing was conducted using 3 lots of GFAP and UCH-L1 reagents, and 1 Alinity i system at each of 3 testing sites. Results Of the 1899 mild TBI subjects, 120 had positive head CT scan results; 116 of the 120 specimens had a positive TBI interpretation (Sensitivity 96.7%;95%CI:91.7%,98.7%). Of the 1779 subjects with negative CT scan results, 713 had a negative TBI interpretation (Specificity 40.1%;95%CI:37.8%,42.4%). The negative predictive value (NPV) of the test was 99.4% (713/717, 95%CI:98.6%,99.8%). Within-Laboratory imprecision (includes repeatability, between-run, and between-day variance components) results ranged from 2.2% to 3.5% CV for GFAP and 1.8 to 3.2 %CV for UCH-L1. The Overall Reproducibility (includes repeatability, between-run, between-day, between-lot, between-site, and site-lot interaction variance components) results ranged from 2.5% to 4.7% CV for GFAP and 2.6 to 6.6 %CV for UCH-L1. Conclusion The Alinity i TBI clinical performance results demonstrated that the TBI test is characterized by high sensitivity and high NPV, which supports the clinical utility to assist in determining the need for a CT scan of the head in subjects presenting with suspected mild TBI. The GFAP and UCH-L1 assays demonstrated acceptable reproducibility across a wide dynamic range. These assays can report results within 18 min and be conveniently loaded into the Electronic Health Records to aid clinicians in their triage (or imaging) decisions. Funding The study was funded by Abbott Laboratories and in collaboration with the US Army Medical Materiel Development Activity, US Army Medical Research and Development Command CRADA 20-1266-CRA.

Graphene oxide coatings enhance fluorescence signals in a lateral flow immunoassay for the detection of UCH-L1, a marker for trauma brain injury

We present a lateral flow immunoassay (LFA) for the quantitative, fluorescence-based detection of the trauma brain injury (TBI) biomarker ubiquitin carboxyl-terminal hydrolase-L1 (UCH-L1) that features a layer of graphene oxide (GO) particles over the test zone of nitrocellulose (NC) strips. The introduction of 80 ng of GO at test lines increased fluorescence signals 2–3-fold. This was attributed to an increase in the immobilization of capture antibodies in the top layer of NC, which increased the density of recognition complexes at the surface and hence the signals reaching the reader used. A linear concentration–response relationship was observed in the 0–200 pg/mL UCH-L1 range with an inter assay CoV of 2.65 %. The LOD and LOQ values of 11.1 pg/mL and 33.5 pg/mL were compatible with threshold levels of UCH-L1. Finally, mock plasma samples with UCH-L1 levels characteristic of TBI patients with negative (60 pg/mL) and positive (130 pg/mL) CT scans were successfully analyzed. Storage stability testing further showed that GO did not affect the biological activity of the capture antibody. In summary, we demonstrate that the use of GO particles in the top layers of the test zone of NC strips improves signal intensity, which could potentially enhance the accuracy and efficiency of LFA-based diagnosis.

Serum NfL and GFAP are associated with incident dementia and dementia mortality in older adults: The cardiovascular health study.

Circulating neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) have been independently associated with dementia risk. Their additive association, and their associations with dementia-specific mortality, have not been investigated. We associated serum NfL, GFAP, total tau ,and ubiquitin carboxyl-terminal hydrolase-L1, measured in 1712 dementia-free adults, with 19-year incident dementia and dementia-specific mortality risk, and with 3-year cognitive decline. In adjusted models, being in the highest versus lowest tertile of NfL or GFAP associated with a hazard ratio (HR) of 1.49 (1.20-1.84) and 1.38 (1.15-1.66) for incident dementia, and 2.87 (1.79-4.61) and 2.76 (1.73-4.40) for dementia-specific mortality. Joint third versus first tertile exposure further increased risk; HR=2.06 (1.60-2.67) and 9.22 (4.48-18.9). NfL was independently associated with accelerated cognitive decline. Circulating NfL and GFAP may, independently and jointly, provide useful clinical insight regarding dementia risk and prognosis.

Elevated Serum Tau and UCHL-1 Concentrations Within 12 Months of Injury Predict Neurobehavioral Functioning 2 or More Years Following Traumatic Brain Injury: A Longitudinal Study.

Blood-based biomarkers have received considerable attention for their diagnostic and prognostic value in the acute and postacute period following traumatic brain injury (TBI). The purpose of this study was to examine whether blood-based biomarker concentrations within the first 12 months of TBI can predict neurobehavioral outcome in the chronic phase of the recovery trajectory. Inpatient and outpatient wards from 3 military medical treatment facilities. A total of 161 service members and veterans classified into 3 groups: ( a ) uncomplicated mild TBI (MTBI; n = 37), ( b ) complicated mild, moderate, severe, penetrating TBI combined (STBI; n = 46), and ( c ) controls (CTRL; n = 78). Prospective longitudinal. Participants completed 6 scales from the Traumatic Brain Injury Quality of Life (ie, Anger, Anxiety, Depression, Fatigue, Headaches, and Cognitive Concerns) within 12 months (baseline) and at 2 or more years (follow-up) post-injury. Serum concentrations of tau, neurofilament light, glial fibrillary acidic protein, and UCHL-1 at baseline were measured using SIMOA. Baseline tau was associated with worse anger, anxiety, and depression in the STBI group at follow-up ( R2 = 0.101-0.127), and worse anxiety in the MTBI group ( R2 = 0.210). Baseline ubiquitin carboxyl-terminal hydrolase L1 (UCHL-1) was associated with worse anxiety and depression at follow-up in both the MTBI and STBI groups ( R2 Δ = 0.143-0.207), and worse cognitive concerns in the MTBI group ( R2 Δ = 0.223). A blood-based panel including these biomarkers could be a useful tool for identifying individuals at risk of poor outcome following TBI.

Changes and significance of serum ubiquitin carboxyl-terminal hydrolase L1 and glial fibrillary acidic protein in patients with glioma

Brain gliomas are malignant tumors with high postoperative recurrence rates. Early prediction of prognosis using specific indicators is of great significance. To assess changes in ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) levels in patients with glioma pre-and postoperatively. Between June 2018 and June 2021, 91 patients with gliomas who underwent surgery at our hospital were enrolled in the glioma group. Sixty healthy volunteers were included in the control group. Serum UCH-L1 and GFAP levels were measured in peripheral blood collected from patients with glioma before and 3 d after surgery. UCH-L1 and GFAP levels in patients with glioma with different clinicopathological characteristics were compared before and after surgery. The patients were followed-up until February 2022. Postoperative glioma recurrence was recorded to determine the serum UCH-L1 and GFAP levels, which could assist in predicting postoperative glioma recurrence. UCH-L1 and GFAP levels in patients with glioma decreased significantly 3 d after surgery compared to those before therapy (P < 0.05). However, UCH-L1 and GFAP levels in the glioma group were significantly higher than those in the control group before and after surgery (P < 0.05). There were no statistically significant differences in preoperative serum UCH-L1 and GFAP levels among patients with glioma according to sex, age, pathological type, tumor location, or number of lesions (P > 0.05). Serum UCH-L1 and GFAP levels were significantly lower in the patients with WHO grade I-II tumors than in those with grade III-IV tumors (P < 0.05). Serum UCH-L1 and GFAP levels were lower in the patients with tumor diameter ≤ 5 cm than in those with diameter > 5 cm, in which the differences were statistically significant (P < 0.05). Glioma recurred in 22 patients. The preoperative and 3-d postoperative serum UCH-L1 and GFAP levels were significantly higher in the recurrence group than these in the non-recurrence group (P < 0.05). Receiver operating characteristic curves were plotted. The areas under the curves of preoperative serum UCH-L1 and GFAP levels for predicting postoperative glioma recurrence were 0.785 and 0.775, respectively. However, the efficacy of serum UCH-L1 and GFAP levels 3 d after surgery in predicting postoperative glioma recurrence was slightly lower compared with their preoperative levels. UCH-L1 and GFAP efficiently reflected the development and recurrence of gliomas and could be used as potential indicators for the recurrence and prognosis of glioma.

Plasma UCHL-1 as a Biomarker of Brain Injury in Hospitalized Foals With Neonatal Encephalopathy

A plasma biomarker such as ubiquitin carboxyl-terminal hydrolase L1 (UCHL-1) to distinguish neonatal encephalopathy (NE) from other disorders and provide prognostic information would be useful for equine practitioners. In this prospective study, plasma UCHL-1 was measured in 331 hospitalized foals ≤4 days of age. Clinical diagnoses of neonatal encephalopathy only (NE group, n = 77), sepsis only (Sepsis group, n = 34), concurrent sepsis and NE (NE+Sepsis group, n = 85), or neither sepsis nor NE (Other group, n = 101) were made by the attending veterinarian. Plasma UCHL-1 concentrations were measured by ELISA. Differences between clinical diagnoses groups were evaluated and receiver operator curve (ROC) analysis was performed to assess diagnostic and prognostic performance. Median admission UCHL-1 concentration was significantly higher for NE (18.22 ng/mL; 7.93–37.43) and NE+Sepsis (17.42 ng/mL; 7.67–36.24) groups than Other foals (7.77 ng/mL; 3.92–22.76). Admission UCHL-1 was significantly higher in nonsurvivors (16.66 ng/mL; 6.89–34.84) than survivors (10.27 ng/mL; 5.82–29.94). Overall diagnostic performance of admission UCHL-1 concentration for NE diagnosis was determined (AUC 0.61; 95% confidence interval [CI] = 0.55–0.68); sensitivity and specificity for predicting NE were 73% and 49% respectively. Overall prognostic performance of time to lowest UCHL-1 concentration for predicting nonsurvival was determined (AUC 0.72; 95% CI = 0.65–0.79); sensitivity and specificity were 86% and 43% respectively. In this foal population, differences in plasma UCHL-1 concentrations were observed between foals with NE or NE with sepsis, and other diagnoses. The diagnostic and prognostic value of admission UCHL-1 concentration was limited.

Podocyte-specific deletion of ubiquitin carboxyl-terminal hydrolase L1 causes podocyte injury by inducing endoplasmic reticulum stress.

Ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) is a unique component of the ubiquitin-proteasome system (UPS), which has multiple activities in maintaining intracellular ubiquitin levels. We previously reported the aberrant low expression of UCHL1 in podocytes of non-immune complex-mediated glomerulonephritis, and recent studies indicate that anti-UCHL1 antibody was responsible for the refractory minimal change disease (MCD), but the specific effect of UCHL1 to the podocytopathy has not been determined. Therefore, we generated podocyte-specific UCHL1 gene knockout (UCHL1cre/cre) rats model. Podocyte-specific UCHL1 knockout rats exhibited severe kidney damage, including segmental/global glomerulosclerosis, kidney function damage and severe proteinuria, compared with littermate control. Subsequently, by carrying out mass spectrometry analysis of isolated glomeruli of rats, abnormal protein accumulation of ECM-receptor Interaction was found in UCHL1cre/cre rats. Mechanistic studies in vivo and in vitro revealed that aberrant protein accumulation after UCHL1 deficiency induced endoplasmic reticulum (ER) stress, unfolded protein reaction (UPR) to reduce the protein level of podocyte skeleton proteins, and CHOP mediated apoptosis as well, which related to the dysfunction of the ubiquitin-proteasome system with decreased free monomeric ubiquitin level, thereby affecting protein ubiquitination and degradation. In addition, inhibition of ER stress by 4-PBA could attenuate the degree of ER stress and podocyte dysfunction. Our study indicates that UCHL1 is a potential target for preventing podocytes injury in some non-immune complex-mediated glomerulopathy.

Targeted epigenetic silencing of UCHL1 expression suppresses collagen-1 production in human lung epithelial cells

ABSTRACT Ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) is highly expressed in smokers, but little is known about the molecular mechanism of UCHL1 in airway epithelium and its possible role in affecting extracellular matrix (ECM) remodelling in the underlying submucosa. Since cigarette smoking is a major cause of lung diseases, we studied its effect on UCHL1 expression and DNA methylation patterns in human bronchial epithelial cells, obtained after laser capture micro-dissection (LCM) or isolated from residual tracheal/main stem bronchial tissue. Targeted regulation of UCHL1 expression via CRISPR/dCas9 based-epigenetic editing was used to explore the function of UCHL1 in lung epithelium. Our results show that cigarette smoke extract (CSE) stimulated the expression of UCHL1 in vitro. The methylation status of the UCHL1 gene was negatively associated with UCHL1 transcription in LCM-obtained airway epithelium at specific sites. Treatment with a UCHL1 inhibitor showed that the TGF-β1-induced upregulation of the ECM gene COL1A1 can be prevented by the inhibition of UCHL1 activity in cell lines. Furthermore, upon downregulation of UCHL1 by epigenetic editing using CRISPR/dCas-EZH2, mRNA expression of COL1A1 and fibronectin was reduced. In conclusion, we confirmed higher UCHL1 expression in current smokers compared to non- and ex-smokers, and induced downregulation of UCHL1 by epigenetic editing. The subsequent repression of genes encoding ECM proteins suggest a role for UCHL1 as a therapeutic target in fibrosis-related disease.

Neurologic Biomarkers, Neuroimaging, and Cognitive Function in Persistent Atrial Fibrillation: A Cross-Sectional Study.

The aim of this study was to evaluate the specific neurologic biomarkers, neuroimaging findings, and cognitive function in patients with persistent atrial fibrillation (AF) undergoing electrical cardioversion, compared to control subjects. This cross-sectional study included 25 patients with persistent AF undergoing electrical cardioversion and 16 age- and sex-matched control subjects. Plasma levels of glial fibrillary acidic protein (GFAP), neurofilament light protein (NFL), and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1), as well as parameters of neuroimaging and cognitive function, were compared between the groups. Neuroimaging was performed using the standard magnetic resonance imaging (MRI) protocol. Cognitive function was assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS) Cognitive Function Index. Further analysis of neurologic biomarkers was performed based on the subsequent electrical cardioversion. There was no significant difference in GFAP (median of 24.7 vs. 28.7 pg/mL, p = 0.347), UCH-L1 (median of 112.8 vs. 117.7 pg/mL, p = 0.885), and NFL (median of 14.2 vs. 15.4 pg/mL, p = 0.886) levels between AF patients and control subjects. Similarly, neuroimaging showed no between-group difference in large cortical and non-cortical lesions (n = 2, 8.0% vs. n = 0, 0.0%, p = 0.246), small non-cortical lesions (n = 5, 20.0% vs. n = 5, 31.3%, p = 0.413), white matter hyperintensity (n = 23, 92.0% vs. n = 14, 87.5%, p = 0.636), and thromboembolic lesions (n = 0, 0.0% vs. n = 1, 6.3%, p = 0.206). Cognitive assessment did not show any between-group difference in the PROMIS index (52.2 ± 9.6 vs. 51.2 ± 6.2, p = 0.706). Finally, there were no significant dynamics in neurologic biomarkers following electrical cardioversion (p > 0.05). This hypothesis-generating study did not find a significant difference in neurologic biomarkers, neuroimaging findings, or cognitive function between patients with persistent AF and controls. The restoration of sinus rhythm was not significantly associated with a change in neurologic biomarkers. Further powered longitudinal studies are needed to re-assess these findings in an AF population.

Pivotal Role of Ubiquitin Carboxyl-Terminal Hydrolase L1 (UCHL1) in Uterine Leiomyoma.

Uterine leiomyomas are smooth-muscle tumors originating in the myometrium and are the most common pelvic tumors in women of reproductive age. Symptomatic tumors may result in abnormal uterine bleeding, bladder dysfunction, pelvic discomfort, and reproductive issues, such as infertility and miscarriage. There are currently few non-invasive treatments for leiomyoma, but there are no practical early intervention or preventive methods. In this study, human uterine leiomyoma and myometrial tissues were used to detect the protein and mRNA expression levels of UCHL1. To explore the effects of UCHL1 knockdown and inhibition in leiomyoma and myometrial cells, we determined the mRNA expressions of COL1A1 and COL3A1. Collagen gel contraction and wound-healing assays were performed on myometrial and leiomyoma cells. We found that UCHL1 expression was considerably higher in uterine leiomyomas than in the myometrium. COL1A1 and COL3A1 expression levels were downregulated after inhibition of UCHL1 in human leiomyoma cells. Furthermore, the elimination of UCHL1 significantly decreased the migration and contractility of leiomyoma cells. In conclusion, these results indicate that UCHL1 is involved in the growth of leiomyoma in humans. For the treatment of uterine leiomyoma, targeting UCHL1 activity may be a unique and possible therapeutic strategy.

UCHL1 regulated by Sp1 ameliorates cochlear hair cell senescence and oxidative damage.

Age-related hearing loss (ARHL) is the most common cause of hearing loss in the elderly. Ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) is a deubiquitinating enzyme involved in several types of human disease. The present study aimed to investigate the effect of UCHL1 on a hydrogen peroxide (H2O2)-induced ARHL model in cochlear hair cells and uncover its underlying mechanism. Reverse transcription-quantitative (RT-q)PCR and western blot analysis were used to assess UCHL1 expression in HEI-OC1 cells exposed to H2O2. Following UCHL1 overexpression in H2O2-induced HEI-OC1 cells, cell activity was assessed by Cell Counting Kit-8 assay. The content of oxidative stress-associated markers including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and reactive oxygen species (ROS ) was measured using corresponding commercial kits. Cell apoptosis was evaluated by TUNEL assay and western blot analysis. Cell senescence was assessed by senescence-associated β-galactosidase staining and western blot analysis. RT-qPCR and western blot analysis were applied to measure mRNA and protein expression levels, respectively, of specificity protein 1 (Sp1) in H2O2-treated HEI-OC1 cells. In addition, the association between UCHL1 and Sp1 was verified by luciferase reporter and chromatin immunoprecipitation (ChIP) assay. The mRNA and protein expression levels of UCHL1 were also determined in Sp1-overexpressing cells by RT-qPCR and western blot analysis, respectively. Following Sp1 overexpression in UCHL1-overexpressing H2O2-treated HEI-OC1 cells, cell activity, oxidative stress, apoptosis and senescence were assessed. Finally, the expression levels of NF-κB signaling-related proteins p-NF-κB p65 and NF-κB p65 were detected using western blot analysis. The results showed that UCHL1 was downregulated in H2O2-treated HEI-OC1 cells. In addition, UCHL1 overexpression enhanced cell viability and promoted oxidative damage, apoptosis and senescence in H2O2-induced HEI-OC1 cells. Furthermore, Sp1 was upregulated in H2O2-treated HEI-OC1 cells. Additionally, luciferase reporter and ChIP assays demonstrated that Sp1 interacted with the UCHL1 promoter to inhibit UCHL1 transcription. Sp1 overexpression reversed the effect of UCHL1 overexpression on cell viability, oxidative stress, apoptosis, senescence and activation of the NF-κB signaling pathway in H2O2-exposed HEI-OC1 cells. Collectively, the results suggested that UCHL1 transcriptional suppression by Sp1 protected cochlear hair cells from H2O2-triggered senescence and oxidative damage.

Breviscapine Combined with BMSCs Reduces Aβ Deposition in Rat with Alzheimer's Disease by Regulating Circular RNA ciRS-7.

This study aimed to clarify that breviscapine combined with bone marrow mesenchymal stem cells (BMSCs) treatment can reduce Aβ deposition in Alzheimer's disease (AD) patients. AD is a common degenerative disease of the central nervous system. Aβ protein deposition in the cerebral cortex and hippocampus causes neuronal peroxidation damage, synaptic dysfunction, neuroinflammation, and nerve cell apoptosis, and ultimately leads to AD. To investigate whether breviscapine combined with BMSCs treatment can reduce Aβ deposition in AD. The AD rat model was successfully induced by Aβ1-42. The expression of protein and mRNA was detected by western blot and reverse transcription-quantitative PCR (RT-qPCR), respectively. In AD rat brain tissue, the expression of circular RNA ciRS-7 (ciRS-7), ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), and NF-kappaB p65 was significantly downregulated, and the expression of β-amyloid precursor protein (APP), β-site APPcleaving enzyme 1 (BAEC1), and Aβ was upregulated. The expression of ciRS-7, UCHL1, and p65 was significantly upregulated after breviscapine or BMSCs treatment, and there was increased APP and BAEC1 degradation. Notably, breviscapine combined with BMSCs treatment was more effective than either treatment alone. In SH-SY5Y cells, overexpression of ciRS-7 reduced Aβ deposition by upregulating UCHL1 to degrade APP and BAEC1, but these effects were reversed with inhibition of NF-kB signaling. Finally, knockdown of ciRS-7 elevated Aβ, APP, and BAEC1 expression in each group of rats compared with the control. Breviscapine combined with BMSCs treatment can reduce Aβ deposition in AD rats and promote the degradation of APP and BAEC1 by activating NF-kB to promote UCHL1 expression.

Examining the Differences in Biomarkers of Neuronal and Glial Injury Between Autoimmune Neurologic Disease Patients and Healthy Controls

Objective To evaluate differences in concentrations of serum-based biomarkers obtained from a screened healthy control (HC) population compared to age and sex matched autoimmune and inflammatory neurologic disease (AIND) patients. Background Protein markers of neuronal and glial injury have become important, minimally invasive biomarkers for understanding the impact of disease in various neurological disorders, including ongoing research into AINDs. Levels of these proteins in healthy individuals remain unclear. Design/Methods Neurofilament light (NfL), glial fibrillary acidic protein (GFAP), ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1), and total tau (Tau) levels in AIND and HC participants will be compared. Multiple Sclerosis (MS) patients, as inflammatory controls, will be analyzed as well. AIND and HC participant serum samples have been collected to obtain NfL, GFAP, UCH-L1, and Tau protein levels using Quanterix SR-XTM SIMOA. We plan to analyze and compare age and sex matched HC samples to AIND patients for each biomarker, ages ranging from 20-80 years old. Concentrations will be log transformed and analyzed with mixed model regression. Results Healthy Controls (130), AIND (255), and newly diagnosed/treatment naïve MS samples (681) have already been collected. Nineteen HC and AIND (includes NMDA, LGI1, TRIM46, CRMP5, MOG, DPPX, GABA-A, GAD-65) participants were analyzed. Preliminary results for HC show mean Nfl (10.3 pg/mL), GFAP (78.9 pg/mL), UCH-L1 (5.65 pg/mL), and Tau (0.53 pg/mL) levels, and for AIND patients mean Nfl (186.48 pg/mL), GFAP (434.92 pg/mL), UCH-L1 (71.38 pg/mL), and Tau (51.85 pg/mL) levels. While ongoing biomarker analysis will be completed with HC that are age and sex matched, the significantly higher levels in AIND patients highlights the importance of creating baseline values in HC to understand these same biomarkers in AIND patients. Conclusions Preliminary results show NfL and GFAP levels are significantly higher in AIND patients versus HC. Baseline biomarker values are essential for understanding further research in biomarkers related to AIND.