Ubiquitin C-terminal Hydrolase Research Articles

Decipher potential biomarkers of diagnosis and disease activity for NMOSD with AQP4 using LC-MS/MS and Simoa

BackgroundNeuromyelitis optica spectrum disorders (NMOSD) is an autoimmune demyelinating disease, leading recurrently relapses and severe disability. There is a need for new biomarkers to meet clinical needs in diagnosis and monitoring. MethodsThrough liquid chromatography–mass spectrometry/mass spectrometry (LC–MS/MS) analysis, brain lesions from NMO animal models were analyzed to identify potential biomarkers. Then, we assessed the levels of serum glial fibrillary acidic protein (sGFAP), neurofilament light chain (sNfL), Tau protein (sTau) and Ubiquitin C-terminal hydrolase L1 (sUCHL1) using an ultrasensitive single molecule array (Simoa) of AQP4-IgG + NMOSD patients, myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD) patients, multiple sclerosis (MS) patients and healthy controls (HCs). Additionally, we further explored the early diagnosis value of these proteins. ResultsThere were 72 differentially expressed proteins between the NMO and control groups. NfL abundance was elevated when GFAP, UCHL1, and Tau abundance was decreased in the NMO group. Then, we observed that the sGFAP and sUCHL1 levels in patients with NMOSD in the early stage were significantly increased compared to those in control participants. Combined ROCs of the sGFAP, sNfL, and sUCHL1 levels to better predict NMOSD with relapse stages was optimal. Notably, univariate and multivariate analyses demonstrated that the sGFAP and sNfL levels were higher in patients with brain lesions, while the sUCHL1 levels were higher in those with spinal cord lesions during recent relapse. ConclusionsThese findings suggested that sGFAP, sNfL, and sUCHL1 displayed good diagnostic performance in AQP4-IgG + NMOSD and could be novel candidates for early discrimination.

Unravelling the genetic links between Parkinson's disease and lung cancer.

Increase evidence from epidemiological studies have shown an inverse association between Parkinson's disease (PD) and lung cancer. PD and lung cancer are both geriatric diseases, where these two diseases are sharing some common genetic determinants. Several PD-associated genes including alpha synuclein (SNCA), PTEN-induced kinase 1 (PINK1), parkin, parkinsonism associated deglycase (DJ-1), leucine-rich repeat kinase 2 (LRRK2), F-box protein 7 (FBXO7) and ubiquitin C-terminal hydrolase L1 (UCHL1) were reported to have altered expressions in lung cancer patients. This indicates that certain PD-associated genes might be important in conferring anticancer effects. This review aims to depict the physiological functions ofthese genes, and discuss the putative roles of these PD-associated genes in lung cancer. The understanding of the roles of these genes in the lung cancer progression might be important in the identification of new treatment targets for lung cancer. Gene therapy that aims to alter the expressions of these genes could be developed for future anticancer therapy. As a result, studying the roles of these genes in lung cancer may also help to understand their involvements as well as their roles in the pathogenesis ofPD.

The deubiquitinase UCHL1 negatively controls osteoclastogenesis by regulating TAZ/NFATC1 signalling.

The ubiquitin‒proteasome system (UPS) plays a key role in maintaining protein homeostasis and bone remodelling. However, the role of deubiquitinating enzymes (DUBs) in bone resorption is still not well defined. Here, we identified the deubiquitinase ubiquitin C-terminal hydrolase 1 (UCHL1) as a negative regulator of osteoclastogenesis by using the GEO database, proteomic analysis, and RNAi. Osteoclast-specific UCHL1 conditional knockout mice exhibited a severe osteoporosis phenotype in an ovariectomized model. Mechanistically, UCHL1 deubiquitinated and stabilized the transcriptional coactivator with PDZ-binding motif (TAZ) at the K46 residue, thereby inhibiting osteoclastogenesis. The TAZ protein underwent K48-linked polyubiquitination, which was degraded by UCHL1. As a substrate of UCHL1, TAZ regulates NFATC1 through a nontranscriptional coactivator function by competing with calcineurin A (CNA) for binding to NFATC1, which inhibits NFATC1 dephosphorylation and nuclear transport to impede osteoclastogenesis. Moreover, overexpression of UCHL1 locally alleviated acute and chronic bone loss. These findings suggest that activating UCHL1 may serve as a novel therapeutic approach targeting bone loss in various bone pathological states.

Chlorogenic acid modulates the ubiquitin–proteasome system in stroke animal model

BackgroundChlorogenic acid, a phenolic compound, has potent antioxidant and neuroprotective properties. The ubiquitin–proteasome system is an important regulators of neurodevelopment and modulators of neuronal function. This system is associated with neurodevelopment and neurotransmission through degradation and removal of damaged proteins. Activation of the ubiquitin–proteasome system is a critical factor in preventing cell death. We have previously reported a decrease in the activity of the ubiquitin–proteasome system during cerebral ischemia. This study investigated whether chlorogenic acid regulates the ubiquitin–proteasome system in an animal stroke model. In adult rats, middle cerebral artery occlusion (MCAO) surgery was performed to induce focal cerebral ischemia. Chlorogenic acid (30 mg/kg) or normal saline was injected into the abdominal cavity 2 h after MCAO surgery, and cerebral cortex tissues were collected 24 h after MCAO damage.ResultsChlorogenic acid attenuated neurobehavioral disorders and histopathological changes caused by MCAO damage. We identified the decreases in ubiquitin C-terminal hydrolase L1, ubiquitin thioesterase OTUB1, proteasome subunit α type 1, proteasome subunit α type 3, and proteasome subunit β type 4 expression using a proteomics approach in MCAO animals. The decrease in these proteins was alleviated by chlorogenic acid. In addition, the results of reverse transcription-polymerase chain reaction confirmed these changes. The identified proteins were markedly reduced in MCAO damage, while chlorogenic acid prevented these reductions induced by MCAO. The decrease of ubiquitin–proteasome system proteins in ischemic damage was associated with neuronal apoptosis.ConclusionsOur results showed that chlorogenic acid regulates ubiquitin–proteasome system proteins and protects cortical neurons from neuronal damage. These results provide evidence that chlorogenic acid has neuroprotective effects and maintains the ubiquitin–proteasome system in ischemic brain injury.

The assessment of ubiquitin C‐terminal hydrolase‐1 (UCH‐L1) in patients with Alzheimer’s disease

AbstractBackgroundAlzheimer's disease is a debilitating disease that leads to a disability of the patient and it is therefore interesting not only from a medical but also from a legal point of view. Despite progress in studies on pathological mechanisms underlying the Alzheimer's disease (AD) still remains incurable. One of the mechanisms responsible for the oligomerization / aggregation of misfolded or damaged proteins in AD may be dysfunction of the ubiquitin‐proteasome system (UPS), including the highly abundant neuronal enzyme ubiquitin carboxyl‐terminal hydrolase L1 (UCHL‐1). UCHL‐1 is involved in the regulation of proteasomal degradation of damaged proteins. The presence of UCH‐L1 was found in neurofibrillary tangles in the AD brain. The aim of the present study was to measure UCHL1 levels in the cerebrospinal fluid (CSF) patients with AD and evaluate a relationship between concentrations of UCHL1 and classical neurochemical dementia biomarkers.MethodThe concentrations of UCHL‐1 and classical AD biomarkers were measured in 30 subjects, including AD patients and individuals from control group by means of multiplexing assay.ResultThe CSF concentration of UCHL‐1 was significantly higher in AD group in comparison with cognitively normal individuals. Additionally, in the whole study group levels of UCHL‐1 correlated negatively with decreased concentration of Aβ 1‐42, MMSE. Furthermore, the significant relationship between UCHL‐1 and tau proteins was also revealed.ConclusionThe study suggest a potential role of UCHL‐1 protein in the pathology of AD and its potential usefulness as a candidate biomarker of AD, but these investigations need to be further confirmed.

PD34 Neuron-specific Biomarkers Associated With Neurological Manifestations In COVID-19: An Evidence Mapping Systematic Review

IntroductionWe aimed to map and synthesize the available evidence on neuron-specific biomarkers related to COVID-19.MethodsA systematic review and qualitative evidence mapping synthesis was performed (PROSPERO-CRD42021266995). Searches were conducted in PubMed and Scopus, and complemented by manual search (July 2021). We included observational studies of any design assessing neurological biomarkers in adult patients (>18 years; with or without neurological comorbidities) diagnosed with COVID-19. Methodological quality of nonrandomized studies (case-control, cohorts) was assessed using the Newcastle-Ottawa Scale.ResultsOverall, 14 studies (n=485 patients) conducted in Sweden (n=4 articles, 28.5%), Germany (n=3; 21.4%), USA (n=3; 21.4%), Canada, France, Italy and Norway (n=1 study each) were included. The most reported neurological symptoms (n=13 studies, 92.8%) were headache, confusion, general weakness, loss of smell/taste, cognitive impairments and behavioral changes. Prevalent neurological conditions included encephalopathies, neuropathies, myopathies, and delirium; most critical cases presented cerebrovascular events (n=4 studies, 28.5%). Hypertension, diabetes, obesity, dyslipidemia, and chronic lung disease were the most reported comorbidities. Eight different neuron-specific biomarkers were found in primary studies: neurofilament-light chain – NfL (n=10 studies; 71.4%), glial fibrillary acidic-protein – GFAp (n=5; 35.7%), tau protein (n=5; 35.7%), neurofilament-heavy chain – NfH, S100B protein, ubiquitin C-terminal hydrolase L1 - UCH-L1, neuron-specific enolase and beta protein-amyloid – Aβ (n=1 study each). These biomarkers were found both in cerebrospinal fluid and blood/plasma samples even without an evident cytokine storm. In patients with COVID-19, NfL and GFAp can act as sensitive indicators of neuroaxonal and astrocytic damages, respectively. Increased levels of NfL were significantly associated with severe COVID-19, unconsciousness and longer stay in the intensive care unit (p<0.05). Studies had an overall poor to moderate methodological quality.ConclusionsWe identified eight neuron-specific biomarkers that should be further studied as prognostic factors of COVID-19. These findings can also guide the development of targeted therapies against SARS-CoV-2. Additional well-designed clinical trials are needed to strengthen this evidence and help understand the mechanisms of neurological symptoms and sequelae after COVID-19 infection.

Strategies for Monitoring "Ubiquitin C-Terminal Hydrolase 1" (Yuh1) Activity.

The family of ubiquitin C-terminal hydrolases (UCHs(releases ε-linked amide bonds positioned at the C-terminus of ubiquitin. UCHL3 is a highly conserved and dual functional member of this family, recognizing C-terminal extensions of two paralogous modifiers: ubiquitin and NEDD8. The Saccharomyces cerevisiae orthologue of UCHL3, namely, Yuh1, is the only UCH family member in this organism. Like UCHL3, Yuh1 recognizes ubiquitin as well as Rub1, the direct orthologue of NEDD8 in S. cerevisiae. We describe here a method for examining the activity of bacteria and yeast expressed Yuh1 by monitoring the C-terminal trimming of UBB+1 and Rub1+1 through immunoblotting and the increased AMC fluorescence readout detected through a plate reader.

Diagnostic Performance and Clinical Applicability of Blood-Based Biomarkers in a Prospective Memory Clinic Cohort.

Blood-based biomarkers have emerged as minimally invasive options for evaluating cognitive impairment. Most studies to date have assessed them in research cohorts, limiting their generalization to everyday clinical practice. We evaluated their diagnostic performance and clinical applicability in a prospective, real-world, memory clinic cohort. All patients referred with suspected cognitive impairment between July 2019 and June 2021 were prospectively invited to participate. Five plasma biomarkers (tau phosphorylated at threonine 181 [p-tau181], glial fibrillary acidic protein [GFAP], neurofilament light chain [NfL], total tau [t-tau], and ubiquitin C-terminal hydrolase L1 [UCH-L1]) were determined with single-molecule array. Performance was assessed in comparison to clinical diagnosis (blinded to plasma results) and amyloid status (CSF/PET). A group of cognitively unimpaired (CU) controls was also included. Three hundred forty-nine participants (mean age 68, SD 8.3 years) and 36 CU controls (mean age 61.7, SD 8.2 years) were included. In the subcohort with available Alzheimer disease (AD) biomarkers (n = 268), plasma p-tau181 and GFAP had a high diagnostic accuracy to differentiate AD from non-neurodegenerative causes (area under the receiver operating characteristic curve 0.94 and 0.92, respectively), with p-tau181 systematically outperforming GFAP. Plasma p-tau181 levels predicted amyloid status (85% sensitivity and specificity) with accurate individual prediction in approximately 60% of the patients. Plasma NfL differentiated frontotemporal dementia (FTD) syndromes from CU (0.90) and non-neurodegenerative causes (0.93), whereas the discriminative capacity with AD and between all neurodegenerative and non-neurodegenerative causes was less accurate. A combination of p-tau181 and NfL identified FTD with 82% sensitivity and 85% specificity and had a negative predictive value for neurodegenerative diagnosis of 86%, ruling out half of the non-neurodegenerative diagnoses. In the subcohort without AD biomarkers, similar results were obtained. T-tau and UCH-L1 did not offer added diagnostic value. Plasma p-tau181 predicted amyloid status with high accuracy and could have potentially avoided CSF/amyloid PET testing in approximately 60% of subjects in a memory clinic setting. NfL was useful for identifying FTD from non-neurodegenerative causes but behaved worse than p-tau181 in all other comparisons. Combining p-tau181 and NfL improved diagnostic performance for FTD and non-neurodegenerative diagnoses. However, the 14% false-negative results suggest that further improvement is needed before implementation outside memory clinics. This study provides Class I evidence that plasma p-tau181 correlates with the presence or absence of AD and a combination of plasma p-tau181 and NfL correlates moderately well with a diagnosis of FTD.

Blood Biomarkers for Return to Play after Concussion in Professional Rugby Players.

We prospectively evaluated a panel of seven blood biomarkers (S100 calcium-binding protein B [S100B], neuron specific enolase [NSE], spectrin breakdown products [SBDP], ubiquitin C-terminal hydrolase L1 [UCHL1], glial fibrillary acidic protein [GFAP], neurofilament light chain [NFL], and tubulin-associated unit [Tau]) for sport-related concussion (SRC) in a large multi-centric cohort of 496 professional rugby players from 14 French elite teams. Players were sampled twice during the season (beginning and end) away from any sport practice. From these two baseline samples, we evaluated the intra-individual variability to establish the effect of rugby on blood biomarkers over a season. Only S100B and GFAP remained stable over the course of a season. During the period of the study, a total of 45 SRC cases was reported for 42 players. In 45 SRCs, the head injury assessment (HIA) process was performed and blood collection was realized 36 h after the concussion (HIA-3 stage). For each biomarker, raw concentrations measured 36 h after SRC were not significantly different between players with a non-resolutive SRC (n = 28) and those with a resolutive SRC (n = 17; p between 0.06 and 0.92). In a second step, blood concentrations measured 36 h after SRC were expressed according to the basal concentrations as an individual percentage change (PCH36[%]), calculated as follows: PCH36 = 100 × (([Biomarker]36h - [Biomarker]basal)/[Biomarker]basal). S100B and NFL concentrations expressed as PCH36[%] were significantly different between non-resolutive and resolutive SRCs (p = 0.006 and 0.01 respectively), with a positive delta found in non-resolutive SRCs. Among the two biomarkers, it is important to note that only the S100B protein was stable during the season. In the context of our study, during HIA-3 assessment, S100B seems to perform better than NSE, SBDP, UCHL1, GFAP, NFL, and Tau as biomarker for SRC. From a clinical standpoint, the S100B modification over baseline may be valuable, at 36 h after concussion to distinguish non-resolutive SRC from resolutive SRC.

Evaluation of cerebrospinal fluid ubiquitin C-terminal hydrolase-L1, glial fibrillary acidic protein, and neurofilament light protein as novel markers for the diagnosis of neurosyphilis among HIV-negative patients

To evaluate the possibility of using cerebrospinal fluid (CSF) ubiquitin C-terminal hydrolase L1 (UCH-L1), glial fibrillary acidic protein (GFAP), and neurofilament light protein (NF-L) for the diagnosis of neurosyphilis (NS). A cross-sectional study of 576 subjects was conducted at Zhongshan Hospital from January 2021 to August 2022 to evaluate the diagnostic accuracy of CSF UCH-L1, GFAP, and NF-L for NS and analyze their correlations with CSF rapid plasma reagin (RPR), white blood cells (WBCs), and protein. Patients with NS had higher CSF UCH-L1, GFAP, and NF-L levels than patients with syphilis/non-NS and nonsyphilis. Using a cut-off point of 652.25 pg/ml, 548.89 pg/ml, and 48.38 pg/ml, CSF UCH-L1, GFAP, and NF-L had a sensitivity of 85.11%, 76.60%, and 82.98%, with a specificity of 92.22%, 85.56%, and 91.11%, respectively, for NS diagnosis. Moreover, parallel and serial testing algorithms improved their sensitivity and specificity to 93.62% and 98.89%, respectively. Interestingly, levels between patients with NS who are CSF RPR-positive and -negative did not differ and showed a weak or moderate correlation with WBC and CSF protein in patients with syphilis. CSF UCH-L1, GFAP, and NF-L can be used as novel markers for the diagnosis of NS, independent of CSF RPR, WBC, and proteins.

UCHL5 Promotes Proliferation and Migration of Bladder Cancer Cells by Activating c-Myc via AKT/mTOR Signaling.

Ubiquitin C-terminal hydrolase L5 (UCHL5) is a deubiquitinating enzyme (DUB) that removes ubiquitin from its substrates. Associations between UCHL5 and cancer have been reported in various tissues, but the effect of UCHL5 on bladder cancer has not been thoroughly investigated. This study investigates the expression and function of UCHL5 in bladder cancer. UCHL5 was shown to be abnormally expressed using IHC of tissue microarray and Western blotting. Several procedures were performed to assess the effect of UCHL5 overexpression or knockdown on bladder cancer, such as cell proliferation, colony formation, wound-healing, and Transwell assays. In addition, RNA-Seq and Western blotting experiments were used to verify the status of downstream signaling pathways. Finally, bladder cancers with knockdown or overexpression of UCHL5 were treated with either SC79 or LY294002 to examine the participation of the AKT/mTOR signaling pathway and the expression of downstream targets c-Myc, SLC25A19, and ICAM5. In contrast to adjacent tissue samples, we discovered that UCHL5 was substantially expressed in bladder cancer samples. We also found that UCHL5 downregulation significantly suppressed both tumor growth in vivo and cell proliferation and migration in vitro. According to RNA-Seq analyses and Western blotting experiments, the expression of c-Myc, SLC25A19, and ICAM5 was modified as a result of UCHL5 activating AKT/mTOR signaling in bladder cancer cells. All things considered, our findings show that increased UCHL5 expression stimulates AKT/mTOR signaling, subsequently triggering the expression of c-Myc, SLC25A19, and ICAM5, which in turn promotes carcinogenesis in bladder cancer. UCHL5 is therefore a potential target for therapy in bladder cancer patients.

BAP1 depletion in human B-lymphoblast cells affects the production of innate immune cytokines and chemokines.

BRCA1 associated protein 1 (BAP1) is a ubiquitin C-terminal hydrolase that deubiquitinates histone H2AK119ub and other proteins and regulates the expression of multiple genes. The knockout of this tumor suppressor gene results in severe thymic atrophy, complete loss of the T cell lineage, and abnormal B cell development in mice. In the current study, we investigated in vitro effects of BAP1 knockout on cytokine and chemokine production using the human B-lymphoblast cell line TSCE5. We confirmed that knockout changed the production of innate immune-associated genes and their receptors. The CCL19, CCR7, CCL2, and CXCR5 genes associated with T and B cell migration were upregulated. Knockout cells producing high levels of CCL19 showed acceleration of actin polymerization, which is essential for cell migration. CD69, PTPRC, and TLR3 genes that activate inflammation were downregulated. The tumor necrosis factor ligand genes TNF, LTA, and TNFSF10 were downregulated by knockout. In knockout cells, TNFα production was strongly downregulated upon the addition of H2 O2 , but NF-κB in the basal condition and when TNFα was added was augmented, suggesting that these cells could respond to TNFα. These results indicated that BAP1 affects the expression of chemokines and cytokines, T and B cell migration, and activated inflammation associating with innate immunity.

Ubiquitin C-terminal hydrolase 1 inhibits the ubiquitination of CaMK Ⅱ and promots the occurrence of atrial fibrillation in rats

Ubiquitin C-terminal hydrolase 1 inhibits the ubiquitination of CaMK Ⅱ and promots the occurrence of atrial fibrillation in rats

Ubiquitin C-terminal hydrolase L1 (UCHL1), a double-edged sword in mammalian oocyte maturation and spermatogenesis.

Recent studies have shown that ubiquitin-mediated cell apoptosis can modulate protein interaction and involve in the progress of oocyte maturation and spermatogenesis. As one of the key regulators involved in ubiquitin signal, ubiquitin C-terminal hydrolase L1 (UCHL1) is considered a molecular marker associated with spermatogonia stem cells. However, the function of UCHL1 was wildly reported to regulate various bioecological processes, such as Parkinson's disease, lung cancer, breast cancer and colon cancer, how UCHL1 affects the mammalian reproductive system remains an open question. We identified papers through electronic searches of PubMed database from inception to July 2022. Here, we summarize the important function of UCHL1 in controlling mammalian oocyte development, regulating spermatogenesis and inhibiting polyspermy, and we posit the balance of UCHL1 was essential to maintaining reproductive cellular and tissue homeostasis. This study considers the 'double-edged sword' role of UCHL1 during gametogenesis and presents new insights into UCHL1 in germ cells.

Cognitive dysfunction associated with COVID-19: Prognostic role of circulating biomarkers and microRNAs.

COVID-19 is renowned as a multi-organ disease having subacute and long-term effects with a broad spectrum of clinical manifestations. The evolving scientific and clinical evidence demonstrates that the frequency of cognitive impairment after COVID-19 is high and it is crucial to explore more clinical research and implement proper diagnostic and treatment strategies. Several central nervous system complications have been reported as comorbidities of COVID-19. The changes in cognitive function associated with neurodegenerative diseases develop slowly over time and are only diagnosed at an already advanced stage of molecular pathology. Hence, understanding the common links between COVID-19 and neurodegenerative diseases will broaden our knowledge and help in strategizing prognostic and therapeutic approaches. The present review focuses on the diverse neurodegenerative changes associated with COVID-19 and will highlight the importance of major circulating biomarkers and microRNAs (miRNAs) associated with the disease progression and severity. The literature analysis showed that major proteins associated with central nervous system function, such as Glial fibrillary acidic protein, neurofilament light chain, p-tau 181, Ubiquitin C-terminal hydrolase L1, S100 calcium-binding protein B, Neuron-specific enolase and various inflammatory cytokines, were significantly altered in COVID-19 patients. Furthermore, among various miRNAs that are having pivotal roles in various neurodegenerative diseases, miR-146a, miR-155, Let-7b, miR-31, miR-16 and miR-21 have shown significant dysregulation in COVID-19 patients. Thus the review consolidates the important findings from the numerous studies to unravel the underlying mechanism of neurological sequelae in COVID-19 and the possible association of circulatory biomarkers, which may serve as prognostic predictors and therapeutic targets in future research.

UBIQUITIN C-TERMINAL HYDROLASE L1 (UCHL1) AND THE TERRIBLE, NO GOOD OVARIAN FOLLICLE

Ubiquitin C-Terminal Hydrolase L1 (UCHL1) is a de-ubiquitinating enzyme enriched in human and mouse oocytes. Studies of UCHL1 posit that it modulates activity of the epidermal growth factor receptor and overexpression leads to down-regulation of the estrogen receptor. UCHL1 also directly regulates protein stabilization and turnover in developing germ cells. Our lab has demonstrated that mice that are heterozygous or homozygous for UCHL1 deletion exhibit severe subfertility and aberrant ovulation, however the mechanism of these changes is not clear.

Blood-Based Biomarkers of Repetitive, Subconcussive Blast Overpressure Exposure in the Training Environment: A Pilot Study.

Because of their unknown long-term effects, repeated mild traumatic brain injuries (TBIs), including the low, subconcussive ones, represent a specific challenge to healthcare systems. It has been hypothesized that they can have a cumulative effect, and they may cause molecular changes that can lead to chronic degenerative processes. Military personnel are especially vulnerable to consequences of subconcussive TBIs because their training involves repeated exposures to mild explosive blasts. In this pilot study, we collected blood samples at baseline, 6 h, 24 h, 72 h, 2 weeks, and 3 months after heavy weapons training from students and instructors who were exposed to repeated subconcussive blasts. Samples were analyzed using the reverse and forward phase protein microarray platforms. We detected elevated serum levels of glial fibrillary acidic protein, ubiquitin C-terminal hydrolase L1 (UCH-L1), nicotinic alpha 7 subunit (CHRNA7), occludin (OCLN), claudin-5 (CLDN5), matrix metalloprotease 9 (MMP9), and intereukin-6 (IL-6). Importantly, serum levels of most of the tested protein biomarkers were the highest at 3 months after exposures. We also detected elevated autoantibody titers of proteins related to vascular and neuroglia-specific proteins at 3 months after exposures as compared to baseline levels. These findings suggest that repeated exposures to subconcussive blasts can induce molecular changes indicating not only neuron and glia damage, but also vascular changes and inflammation that are detectable for at least 3 months after exposures whereas elevated titers of autoantibodies against vascular and neuroglia-specific proteins can indicate an autoimmune process.

Neurofilament light as a predictive biomarker of unresolved chemotherapy-induced peripheral neuropathy in subjects receiving paclitaxel and carboplatin

Management of chemotherapy-induced peripheral neuropathy (CIPN) remains a significant challenge in the treatment of cancer. Risk mitigation for CIPN involves preemptive reduction of cumulative dose or reduction of dose intensity upon emergence of symptoms, despite the risk of reduced tumor efficacy. A predictive biomarker for dose-limiting CIPN could improve treatment outcomes by allowing providers to make informed decisions that balance both safety and efficacy. To identify a predictive biomarker of CIPN, markers of neurodegeneration neurofilament-light (NfL), glial fibrillary acidic protein (GFAP), tau and ubiquitin c-terminal hydrolase L1 (UCHL1) were assessed in serum of up to 88 subjects drawn 21 days following the first of 6 treatments with chemotherapeutics paclitaxel and carboplatin. Serum NfL and GFAP were increased with chemotherapy. Further, NfL change predicted subsequent onset of grade 2–3 CIPN during the remainder of the trial (mean treatment duration = 200 days) and trended toward stronger prediction of CIPN that remained unresolved at the end of the study. These results confirm previous reports that serum NfL is increased in CIPN and provide the first evidence that NfL can be used to identify subjects susceptible to dose-limiting paclitaxel and carboplatin induced CIPN prior to onset of symptoms.

Structural Insights into the Phosphorylation-Enhanced Deubiquitinating Activity of UCHL3 and Ubiquitin Chain Cleavage Preference Analysis.

Ubiquitin C-terminal hydrolase-L3 (UCHL3), an important member of the ubiquitin C-terminal hydrolase family, is involved in DNA repair and cancer development. UCHL3 can cleave only complexes of monoubiquitin and its conjugates, such as Ub-AMC, His, or small ubiquitin-like modifier, but not polyubiquitin chains. Phosphorylation of Ser75 promotes the cleavage activity of UCHL3 toward poly-ubiquitin chains in vivo, but biochemical evidence in vitro is still lacking. Here, we first analyzed the structure of simulated phosphorylated UCHL3S75E and the complex of UCHL3S75E with Ub-PA and preliminarily explained the structural mechanism of phosphorylation-enhanced UCHL3 deubiquitinating activity. Additionally, the cleavage activity of UCHL3 toward different types of synthesized poly-ubiquitin chains in vitro was tested. The results showed that purified UCHL3S75E enhanced the cleavage activity toward Ub-AMC compared to UCHL3WT. Meanwhile, UCHL3S75E and UCHL3WT did not show any cleavage activity for different types of di-ubiquitin and tri-ubiquitin chains. However, UCHL3 could hydrolyze the K48 tetra-ubiquitin chain, providing compelling in vitro evidence confirming previous in vivo results. Thus, this study shows that UCHL3 can hydrolyze and has a cleavage preference for polyubiquitin chains, which expands our understanding of the phosphorylation regulation of UCHL3 and lays a foundation for further elucidation of its physiological role.

UCHL1 Impairs Periodontal Ligament Stem Cell Osteogenesis in Periodontitis

Periodontitis comprises a series of inflammatory responses resulting in alveolar bone loss. The suppression of osteogenesis of periodontal ligament stem cells (PDLSCs) by inflammation is responsible for impaired alveolar bone regeneration, which remains an ongoing challenge for periodontitis therapy. Ubiquitin C-terminal hydrolase L1 (UCHL1) belongs to the family of deubiquitinating enzymes, which was found to play roles in inflammation previously. In this study, the upregulation of UCHL1 was identified in inflamed PDLSCs isolated from periodontitis patients and in healthy PDLSCs treated with tumor necrosis factor–α or interleukin–1β, and the higher expression level of UCHL1 was accompanied with the impaired osteogenesis of PDLSCs. Then UCHL1 was inhibited in PDLSCs using the lentivirus or inhibitor, and the osteogenesis of PDLSCs suppressed by inflammation was rescued by UCHL1 inhibition. Mechanistically, the negative effect of UCHL1 on the osteogenesis of PDLSCs was attributable to its negative regulation of mitophagy-dependent bone morphogenetic protein 2/Smad signaling pathway in periodontitis-associated inflammation. Furthermore, a ligature-induced murine periodontitis model was established, and the specific inhibitor of UCHL1 was administrated to periodontitis mice. The histological results showed increased active osteoblasts on alveolar bone surface and enhanced alveolar bone regeneration when UCHL1 was inhibited in periodontitis mice. Besides, the therapeutic effects of UCHL1 inhibition on ameliorating periodontitis were verified, as indicated by less bone loss and reduced inflammation. Altogether, our study proved UCHL1 to be a key negative regulator of the osteogenesis of PDLSCs in periodontitis and suggested that UCHL1 inhibition holds promise for alveolar bone regeneration in periodontitis treatment.