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Background: Ubiquitin C-terminal hydrolase isozyme L1 (UCHL1) is primarily expressed in neuronal cells and neuroendocrine cells and has been associated with various diseases, including many cancers. It is a multifunctional protein involved in deubiquitination, ubiquitination and ubiquitin homeostasis, but its specific roles are disputed and still generally undetermined. Results: Herein, we demonstrate that UCHL1 is associated with genomic DNA in certain prostate cancer cell lines, including DU 145 cells derived from a brain metastatic site, and in HEK293T embryonic kidney cells with a neuronal lineage. Chromatin immunoprecipitation and sequencing revealed that UCHL1 localizes to TTAGGG repeats at telomeres and interstitial telomeric sequences, as do TRF1 and TRF2, components of the shelterin complex. A weak or transient interaction between UCHL1 and the shelterin complex was confirmed by immunoprecipitation and proximity ligation assays. UCHL1 and RAP1, also known as TERF2IP and a component of the shelterin complex, were bound to the nuclear scaffold. Conclusions: We demonstrated a novel feature of UCHL1 in binding telomeres and interstitial telomeric sites. [ABSTRACT FROM AUTHOR]

Purpose Diabetic retinopathy (DR) is the most frequently occurring complication of diabetes. Alterations in ubiquitin–proteasome system (UPS) have been associated with several degenerative disorders. Hence, in this study, we investigated the status and role of UPS and ER stress in the retina of diabetic rats. Methods Diabetes was induced in rats by streptozotocin. Retinal markers, ER stress markers, components of UPS, ERAD, and autophagy were analyzed after 2- and 4-months of diabetes. Apoptosis was analyzed by TUNEL Assay. Results There were increased acellular capillaries and pericyte loss in diabetic rat retina. Decreased protein expression of UPS components - ubiquitin activating enzyme (E1), deubiquitinating enzymes (UCHL1 and UCHL5), SIAH1 (E3 ligase) and free ubiquitin were observed in the diabetic rats. Increased ER stress markers (ATF6, XBP1, and CHOP), decreased expression of HRD1, declined autophagy (LC3B) and increased apoptosis were observed in diabetic rats. Interestingly, treatment of diabetic rats with a chemical chaperone (4-PBA) restored the levels of DUBs and ameliorated ER stress-induced retinal cell death in type 1 diabetic rats. Conclusion The declined UPS components: E1 and HRD1 in the retina of diabetic rats could elicit ER stress, and the prolonged ER stress may trigger CHOP-mediated neuronal apoptosis. [ABSTRACT FROM AUTHOR]

Brief, non-harmful seizures (preconditioning) can temporarily protect the brain against prolonged, otherwise injurious seizures. Following focal-onset status epilepticus (SE) in preconditioned (tolerance) and sham-preconditioned (injury) mice, we screened for protein changes using a proteomic approach and identified several putative candidates of epileptic tolerance. Among SE-induced changes to both proteomic screens, proteins clustered in key regulatory pathways, including protein trafficking and cytoskeletal regulation. Downregulation of one such protein, ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1), was unique to injury and not evident in tolerance. UCHL1 inhibition decreased hippocampal ubiquitin, disrupted UPS function, interfered with seizure termination and exacerbated seizure-induced cell death. Though UCHL1 transcription was maintained after SE, we observed downregulation of the pro-translational antisense Uchl1 (As Uchl1) and confirmed that both As Uchl1 and rapamycin can increase UCHL1 expression in vivo. These data indicate that the post-transcriptional loss of UCHL1 following SE is deleterious to neuronal survival and may contribute to hyperexcitability, and are suggestive of a novel modality of rapamycin therapy. [ABSTRACT FROM AUTHOR]

Introduction: Spinal muscular atrophy (SMA) is a neurodegenerative disorder characterized by alpha motor neuron loss in the spinal cord due to reduced survival motor neuron (SMN) protein level. While the genetic basis of SMA is well described, the specific molecular pathway underlying SMA is still not fully understood. Areas covered: This review discusses the recent advancements in understanding the molecular pathways in SMA using different omics approaches and genetic modifiers identified in both vertebrate and invertebrate systems. The findings that are summarized in this article were deduced from original articles and reviews with a particular focus on the latest advancements in the field. Expert commentary: The identification of genetic modifiers such asPLS3andNCALDin humans or of SMA modulators such asElavl4(HuD), Copa, Uba1, Mapk10(Jnk3), Nrxn2andTmem41b (Stasimon) in various SMA animal models improved our knowledge of impaired cellular pathways in SMA. Inspiration from modifier genes and their functions in motor neuron and neuromuscular junctions may open a new avenue for future SMA combinatorial therapies. [ABSTRACT FROM PUBLISHER]

Multiple studies have established that brain-derived neurotrophic factor (BDNF) plays a critical role in the regulation of synaptic plasticity via its receptor, TrkB. 1 n addition to being phosphorylated, TrkB has also been demonstrated to be ubiquitinated. However, the mechanisms of TrkB ubiquitination and its biological functions remain poorly understood. In this study, we demonstrate that ubiquitin C-terminal hydrolase LI (UCH-L1) promotes contextual fear conditioning learning and memory via the regulation of ubiquitination of TrkB. We provide evidence that UCH-L1 can deubiquitinate TrkB directly. K460 in the juxtamembane domain of TrkB is the primary ubiquitination site and is regulated by UCH-L1. By using a peptide that competitively inhibits the association between UCH-L1 and TrkB, we show that the blockade of UCH-L1-regulated TrkB deubiquitination leads to increased BDNF-induced TrkB internalization and consequently directs the internalized TrkB to the degradation pathway, resulting in increased degradation of surface TrkB and attenuation of TrkB activation and its downstream signaling pathways. Moreover, injection of the peptide into the DG region of mice impairs hippocampus-dependent memory. Together, our results suggest that the ubiquitination of TrkB is a mechanism that controls its downstream signaling pathways via the regulation of its endocytosis and postendocytic trafficking and that UCH-L1 mediates the deubiquitination of TrkB and could be a potential target for the modulation of hippocampus-dependent memory. [ABSTRACT FROM AUTHOR]

The aberrant accumulation of β-amyloid peptide (Aβ) in the brain is a key feature of Alzheimer's disease ( AD), and enhanced cleavage of β-amyloid precursor protein ( APP) by β-site APP-cleaving enzyme 1 ( BACE1) has a major causative role in AD. Despite their prominence in AD pathogenesis, the regulation of BACE1 and APP is incompletely understood. In this study, we report that the circular RNA circular RNA sponge for miR-7 (ciRS-7) has an important role in regulating BACE1 and APP protein levels. Previous studies have shown that ci RS-7, which is highly expressed in the human brain, is down-regulated in the brain of people with AD but the relevance of this finding was not clear. We have found that ci RS-7 is not involved in the regulation of APP and BACE1 gene expression, but instead reduces the protein levels of APP and BACE1 by promoting their degradation via the proteasome and lysosome. Consequently, overexpression of ci RS-7 reduces the generation of Aβ, indicating a potential neuroprotective role of ci RS-7. Our data also suggest that ci RS-7 modulates APP and BACE1 levels in a nuclear factor-κB (NF-κB)-dependent manner: ci RS-7 expression inhibits translation of NF-κB and induces its cytoplasmic localization, thus derepressing expression of UCHL1, which promotes APP and BACE1 degradation. Additionally, we demonstrated that APP reduces the level of ci RS-7, revealing a mutual regulation of ci RS-7 and APP. Taken together, our data provide a molecular mechanism implicating reduced ci RS-7 expression in AD, suggesting that ci RS-7 may represent a useful target in the development of therapeutic strategies for AD. [ABSTRACT FROM AUTHOR]

Purpose The study aims to determinate concentrations of ubiquitin C-terminal hydrolase 1 (UCHL1), which hydrolyzes amino acids from ubiquitin and cleave di-ubiquitins, in serum of children after thermal injury. Patients/methods 42 children scalded by hot water, managed at the Department of Pediatric Surgery, with burns in 4–20% TBSA were included into the study (age 9 months up to 14 years, mean age 2.5 ± 1 years). Blood plasma UCHL1 concentration was assessed in 2–6 h, 12–16 h, 3d, 5d, and 7d after injury using surface plasmon resonance imaging biosensor. 18 healthy subjects admitted for planned surgeries served as controls. Results The UCHL1 concentration in the blood plasma of patients with thermal injuries reached its peak 12–16 h after thermal injury and slowly decreased over time, and still did not reach the normal range on the 7th day after thermal injury. Mean concentrations of UCHL1 after thermal injury were above the range measured in controls (0.12 ng/ml): 2–6 h after injury – 5.59 ng/dl, 12–16 h after injury – 9.16 ng/dl, 3 days after injury – 6.94 ng/dl, 5 days after 5.41 ng/dl, 7 days after injury – 4.09 ng/dl. Conclusions We observed sudden increase in the concentration of UCHL1 2–16 h after thermal injury with the slow decrease in the UCHL1 concentration over the time. UCHL1 concentration was proportional to the severity of the burn. Further studies are needed to determine the mechanisms by which UCHL1 contributes to metabolic response following thermal injury. [ABSTRACT FROM AUTHOR]

Clear cell renal cell carcinomas (ccRCCs) represent ∼75% of RCC cases and account for most RCC-associated deaths. Inter- and intratumoral heterogeneity (ITH) results in varying prognosis and treatment outcomes. To obtain the most comprehensive profile of ccRCC, we perform integrative histopathologic, proteogenomic, and metabolomic analyses on 305 ccRCC tumor segments and 166 paired adjacent normal tissues from 213 cases. Combining histologic and molecular profiles reveals ITH in 90% of ccRCCs, with 50% demonstrating immune signature heterogeneity. High tumor grade, along with BAP1 mutation, genome instability, increased hypermethylation, and a specific protein glycosylation signature define a high-risk disease subset, where UCHL1 expression displays prognostic value. Single-nuclei RNA sequencing of the adverse sarcomatoid and rhabdoid phenotypes uncover gene signatures and potential insights into tumor evolution. In vitro cell line studies confirm the potential of inhibiting identified phosphoproteome targets. This study molecularly stratifies aggressive histopathologic subtypes that may inform more effective treatment strategies. [Display omitted] • Integrated multi-omics and histopathology reveal intratumoral heterogeneity in ccRCCs • Signatures of aggressive sarcomatoid and rhabdoid histology are uncovered by snRNA-seq • High-grade ccRCCs have specific glycoproteomic, metabolomic, and methylation signatures • UCHL1 correlates with methylation, genome instability, BAP1 mutation, and poor survival Li et al. integrate histopathologic, proteogenomic, and metabolomic data from 305 tumor segments and reveal intratumoral heterogeneity in at least 90% of clear cell renal cell carcinomas, signatures for sarcomatoid and rhabdoid features, and prognostic value of UCHL1. This study molecularly stratifies aggressive histopathologic subtypes to inform effective treatment strategies. [ABSTRACT FROM AUTHOR]

Elevated levels of brain injury biomarkers have been found primarily in middle-aged or older persons experiencing moderate-to-severe COVID-19 symptoms. However, there is little research in young adults, and there is concern that COVID-19 causes brain injury even in the absence of moderate-to-severe symptoms. Therefore, the purpose of our study was to investigate whether neurofilament light (NfL), glial fibrillary acidic protein (GFAP), tau, or ubiquitin carboxyl-terminal esterase L1 (UCHL1) are elevated in the plasma of young adults with mild COVID-19 symptoms. Twelve participants diagnosed with COVID-19 had plasma collected 1, 2, 3, and 4 months after diagnosis to determine whether NfL, GFAP, tau, and UCHL1 concentrations increased over time or whether plasma concentrations were elevated compared with COVID-19-naïve participants. We also compared plasma NfL, GFAP, tau, and UCHL1 concentrations between sexes. Our results showed no difference between NfL, GFAP, tau, and UCHL1 concentrations in COVID-19-naïve participants and COVID-19-positive participants at any of the four time points ( p  = 0.771). Within the COVID-19-positive participants, UCHL1 levels were higher at month 3 after diagnosis compared to month 1 or month 2 ( p  = 0.027). Between sexes, females were found to have higher UCHL1 ( p  = 0.003) and NfL ( p  = 0.037) plasma concentrations compared to males, whereas males had higher plasma tau concentrations than females ( p  = 0.024). Based on our data, it appears that mild COVID-19 in young adults does not increase plasma NfL, GFAP, tau, or UCHL1., Competing Interests: No competing financial interests exist., (© Matthew J. Rogatzki et al., 2023; Published by Mary Ann Liebert, Inc.)

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., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Objective: This study aimed to determine the serum level of Ubiquitin C-terminal hydrolase 1 enzyme during a migraine attack and after its treatment., Methods: Blood samples of 43 patients and 30 healthy controls who presented to the emergency department with migraine attacks were analysed. Study sample was classified into three groups: Group 1 (patients presenting with migraine attack), Group 2 (4thhour after dexketoprofen treatment) and Group 3 (healthy control). Demographic data of patients, visual analogue scale and Ubiquitin C-terminal hydrolase 1 levels were analysed., Results: Median (IQR) Ubiquitin C-terminal hydrolase 1 levels were 13.70 (10.75-18.92) in Group 1, 9.45 (6.95-11.56) in Group 2 and 6.04 (3.88-8.72) ng/mL in Group 3; the Kruskal-Wallis test result showed a significant difference between the groups (P<0.001). Following the Kruskal-Wallis test, the post-hoc Dunn test was performed for binary comparison between the groups, which revealed significant differences between all groups (Group 1-Group 2, Group 1-Group 3 and Group 2-Group 3 with P=0.001, P<0.001 and P=0.008, respectively). Moreover, a significant positive correlation was found between VAS score and UCHL1 levels before treatment (r=0.884, P<0.001)., Conclusion: UCHL1 levels of patients with migraine increase during acute attack and they can be used to assess the severity of attack and response to treatment., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Triple-negative breast cancer (TNBC) is a special kind of breast cancer with strong ability of invasion and metastasis. UCHL1 belongs to the ubiquitin carboxy-terminal hydrolase family and is found to be increased in a variety of malignancies, but its expression in TNBC is unknown. First, we analyzed the expression of UCHL1 in 128 TNBC specimens and paired adjacent normal tissues from 17 TNBC patients undergoing curative resection by immunohistochemistry. Then, the relationship between UCHL1 and cancer stemness was investigated by cell flow cytometry, spheroid formation assays and western blot. Moreover, cell scratch assay and Transwell assays were performed to explore whether UCHL1 promotes the migration and invasion of TNBC cells. Finally, we constructed a xenografts model of TNBC cell lines to observe the effect of UCHL1 on tumorigenesis in vivo. UCHL1 was overexpressed in TNBC tissues and associated with poor prognosis. UCHL1 promoted stem cancer cells properties, including the percentage of CD44+/CD24- cells, sphere-forming ability and CSCs related markers. Furthermore, Scratch assay and Transwell assay proved that UCHL1 enhanced the migration and invasion of TNBC cells. The experimental results of xenografts model in nude mice showed that UCHL1 promoted tumorigenesis of TNBC in vivo. UCHL1 may play a role in the malignant progression of TNBC by maintaining the stemness and promoting cell invasion and is expected to become a potential therapeutic target for TNBC patients. [ABSTRACT FROM AUTHOR]

Objective: Validate single versus sequential culture media for murine embryo development. Design: Prospective laboratory experiment. Setting: Assisted Reproduction Laboratory. Animals: Murine embryos. Interventions: Thawed murine zygotes cultured for 3 or 5 days (d3 or d5) in single or sequential embryo culture media developed for human in vitro fertilization. Main Outcome Measures: On d3, zygotes developing to the 8 cell (8C) stage or greater were quantified using 4’,6-diamidino-2-phenylindole (DAPI), and quality was assessed by morphological analysis. On d5, the number of embryos reaching the blastocyst stage was counted. DAPI was used to quantify total nuclei and inner cell mass nuclei. Localization of ubiquitin C-terminal hydrolase L1 (UCHL1) and ubiquitin C-terminal hydrolase L3 (UCHL3) was reference points for evaluating cell quality. Results: Comparing outcomes in single versus to sequential media, the odds of embryos developing to the 8C stage on d3 were 2.34 time greater (P = .06). On d5, more embryos reached the blastocyst stage (P = <.0001), hatched, and had significantly more trophoblast cells (P = .005) contributing to the increased total cell number. Also at d5, localization of distinct cytoplasmic UCHL1 and nuclear UCHL3 was found in high-quality hatching blastocysts. Localization of UCHL1 and UCHL3 was diffuse and inappropriately dispersed throughout the cytoplasm in low-quality nonhatching blastocysts. Conclusions: Single medium yields greater cell numbers, an increased growth rate, and more hatching of murine embryos. Cytoplasmic UCHL1 and nuclear UHCL3 localization patterns were indicative of embryo quality. Our conclusions are limited to murine embryos but one might speculate that single medium may also be more beneficial for human embryo culture. Human embryo studies are needed. [ABSTRACT FROM AUTHOR]

The ubiquitin-proteasome system plays an essential regulatory role in various cellular processes. Besides its involvement in normal cellular functions, the alteration of proteasomal activity contributes to the pathological states of several clinical disorders, including cancer. Aberrant methylation of the CpG islands has been reported as an alternative way to inactivate gene expression involved in the ubiquitination process and thus protein degradation in tumor tissues. In this study, we aimed to determine the CpG methylation pattern of the UCHL1 promoter, as well as the mutation spectrum and the expression pattern of P53 in sporadic colorectal cancer (CRC) from Tunisian patients. We found that UCHL1 was methylated in 68.57 % and correlated significantly with lymph node metastasis ( P = 0.029) and transcriptional silencing in tumor tissues ( P = 0.013). Mutation screening of exons 5-9 of P53 showed that 42.85 % of cases harbor somatic mutation and are positively correlated with the methylated pattern of UCHL1 ( P = 0.001). Furthermore, cytoplasmic accumulation of P53 was strongly associated with the unmethylated UCHL1 profile ( P = 0.006), supporting the relationship between these two proteins in CRC. [ABSTRACT FROM AUTHOR]

Spinal muscular atrophy (SMA) is an inherited neuromuscular disease primarily characterized by degeneration of spinal motor neurons, and caused by reduced levels of the SMN protein. Previous studies to understand the proteomic consequences of reduced SMN have mostly utilized patient fibroblasts and animal models. We have derived human motor neurons from type I SMA and healthy controls by creating their induced pluripotent stem cells (iPSCs). Quantitative mass spectrometry of these cells revealed increased expression of 63 proteins in control motor neurons compared to respective fibroblasts, whereas 30 proteins were increased in SMA motor neurons vs. their fibroblasts. Notably, UBA1 was significantly decreased in SMA motor neurons, supporting evidence for ubiquitin pathway defects. Subcellular distribution of UBA1 was predominantly cytoplasmic in SMA motor neurons in contrast to nuclear in control motor neurons; suggestive of neurodevelopmental abnormalities. Many of the proteins that were decreased in SMA motor neurons, including beta III-tubulin and UCHL1, were associated with neurodevelopment and differentiation. These neuron-specific consequences of SMN depletion were not evident in fibroblasts, highlighting the importance of iPSC technology. The proteomic profiles identified here provide a useful resource to explore the molecular consequences of reduced SMN in motor neurons, and for the identification of novel biomarker and therapeutic targets for SMA. [ABSTRACT FROM AUTHOR]

Background & Aims Ubiquitination is a reversible protein modification involved in the major cellular processes that define cell phenotype and behaviour. Ubiquitin modifications are removed by a large family of proteases named deubiquitinases. The role of deubiquitinases in hepatic stellate cell (HSC) activation and their contribution to fibrogenesis are poorly defined. We have identified that the deubiquitinase ubiquitin C-terminal hydrolase 1 (UCHL1) is highly induced following HSC activation, determined its function in activated HSC and its potential as a therapeutic target for fibrosis. Methods Deubiquitinase expression was determined in day 0 and day 10 HSC. Increased UCHL1 expression was confirmed in human HSC and in an alcoholic liver disease (ALD) patient liver. The importance of UCHL1 in hepatic fibrosis was investigated in CCl 4 and bile duct ligation injured mice using a pharmacological inhibitor (LDN 57444). The effects of UCHL1 inhibition on HSC proliferation were confirmed by Western blot and 3H thymidine incorporation. Results Here we report that pharmacological inhibition of UCHL1 blocks progression of established fibrosis in CCl 4 injured mice. UCHL1 siRNA knockdown, LDN 57444 treatment, or HSC isolated from UCHL1 −/− mice show attenuated proliferation in response to the mitogen, platelet-derived growth factor. Additionally, we observed changes in the phosphorylation of the cell cycle regulator retinoblastoma protein (Rb) in the absence of UCHL1 highlighting a potential mechanism for the reduced proliferative response. Conclusions UCHL1 expression is highly upregulated upon HSC activation and is involved in the regulation of HSC proliferation. This study highlights therapeutic opportunities for pharmacological targeting of UCHL1 in chronic liver disease. [ABSTRACT FROM AUTHOR]

Ubiquitination is a covalent post-translational modification of proteins by the chaperone protein ubiquitin. Upon docking to the 26S proteasome, ubiquitin is released from the substrate protein by deubiquitinating enzymes (DUBs). We hypothesised that specific inhibitors of two closely related oocyte DUBs, namely inhibitors of the ubiquitin C-terminal hydrolases (UCH) UCHL1 (L1 inhibitor) and UCHL3 (L3 inhibitor), would alter porcine oocyte maturation and influence sperm function and embryo development. Aberrant cortical granule (CG) migration and meiotic spindle defects were observed in oocytes matured with the L1 or L3 inhibitor. Embryo development was delayed or blocked in oocytes matured with the general DUB inhibitor PR-619. Aggresomes, the cellular stress-inducible aggregates of ubiquitinated proteins, formed in oocytes matured with L1 inhibitor or PR-619, a likely consequence of impaired protein turnover. Proteomic analysis identified the major vault protein (MVP) as the most prominent protein accumulated in oocytes matured with PR-619, suggesting that the inhibition of deubiquitination altered the turnover of MVP. The mitophagy/autophagy of sperm-contributed mitochondria inside the fertilised oocytes was hindered by DUB inhibitors. It is concluded that DUB inhibitors alter porcine oocyte maturation, fertilisation and preimplantation embryo development. By regulating the turnover of oocyte proteins and mono-ubiquitin regeneration, the DUBs may promote the acquisition of developmental competence during oocyte maturation. [ABSTRACT FROM AUTHOR]

Ubiquitin C-terminal hydrolase-L1 (UCHL1) is a de-ubiquitinating enzyme, which enzymatic activity relies on the C90 site. The function of UCHL1 is controversial in different types of cancer, and its role in gastric cancer progression remains unclear. In this study, immunohistochemistry staining was applied to detect the expression of UCHL1 in primary gastric cancer and liver metastases from gastric cancer. MKN45 and BGC823 cell lines with stable expression of de-ubiquitinase active UCHL1 or inactive UCHL1-variant C90S were established by lentiviral infection. The effect of UCHL1 on cell proliferation was evaluated by MTT and colony formation assays. The abilities of cell migration and invasion were determined by transwell assay. Protein expression levels were determined by Western blot. The results indicated that UCHL1 had a significantly higher positive expression rate in liver metastases from gastric cancer compared with primary gastric cancer. Overexpression of UCHL1 in MKN45 and BGC823 cells promoted cell proliferation, migration, and invasion depending on its de-ubiquitinase activity. UCHL1 activated Akt and Erk1/2, which process also required enzymatic activity and was necessary for mediating cell migration and invasion. These findings demonstrated that UCHL1 promoted cell proliferation, migration, and invasion depending on its de-ubiquitinase activity by activating Akt and Erk1/2, which may account for its higher positive expression rate in liver metastases from gastric cancer. UCHL1 could be a candidate biomarker and a therapeutic target for gastric cancer metastasis. [ABSTRACT FROM AUTHOR]

Ubiquitin carboxyl terminal hydrolase 1 (UCHL1), a member of the UCH class of DUBs, has been reported as either an oncogene or a tumor suppressor. However, the molecular mechanism underlying the biological function of UCHL1 in osteosarcoma is still unclear. This study was aimed at elucidating the roles of UCHL1 in regulating the biological behavior of osteosarcoma cells. In this study, we found that UCHL1 was elevated in osteosarcoma compared with normal bone tissue. Moreover, UCHL1 expression level was correlated with tumor maximum diameter, high rate of lung metastases and short survival time. Then, we found that knockdown of UCHL1 in osteosarcoma cell MG63 inhibited cell proliferation and significantly increased cell population in the G1 phase. Several cyclins promoting G1/S phase transition were reduced after UCHL1 knockdown, including cell cycle regulator cyclin D1, cyclin E1 and CDK6. Moreover, inhibition of UCHL1 in MG63 cells dramatically induced cell apoptosis. We also found that down-regulation of UCHL1 in MG63 significantly inhibited cell invasion. Then, we found that there was a positive correlation between UCHL1 expression level and the Akt and ERK phosphorylation status. Finally, in vivo data showed that knockdown of UCHL1 inhibited osteosarcoma growth in nude mice. These results indicate that UCHL1 could work as an oncogene and may serve as a promising therapeutic strategy for osteosarcoma. [ABSTRACT FROM AUTHOR]

Deubiquitinases (DUBs) play important roles and therefore are potential drug targets in various diseases including cancer and neurodegeneration. In this review, we recapitulate structure-function studies of the most studied DUBs including USP7, USP22, CYLD, UCHL1, BAP1, A20, as well as ataxin 3 and connect them to regulatory mechanisms and their growing protein interaction networks. W e then describe DUBs that have been associated with endocrine carcinogenesis with a focus on prostate, ovarian, and thyroid cancer, pheochromocytoma, and adrenocortical carcinoma. The goal is enhancing our understanding of the connection between dysregulated DUBs and cancer to permit the design of therapeutics and to establish biomarkers that could be used in diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

The Ubiquitin carboxy-terminal hydrolase-L1 (UCHL1) is a candidate risk gene for Parkinson' disease (PD), and a function SNP (rs5030732) in the coding region of this gene has been studied for the association with the disease extensively among worldwide populations, but the results were inconsistent and controversial. Here, to estimate the association between UCHL1 S18Y polymorphism and risk of PD in general population, we conducted a systematic meta-analysis by combining all available case-control subjects in Asian, European, and American populations, with a total of 7742 PD cases and 8850 healthy controls, and the pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for UCHL1 S18Y polymorphism and PD were calculated using the Mantel-Haenszel method with a fixed- or random-effects model. Subgroup analysis was also performed in different onset age-matched groups. Among high-quality studies, UCHL1 S18Y polymorphism was moderately associated with the risk of PD (allele contrasts, OR = 1.063, 95 % CI 1.008-1.122; p = 0.024; regressive genetic model, OR = 1.078, 95 % CI 1.005-1.157; p = 0.035). When stratifying for ethnicity, none association were observed in subgroups. Analysis of early-onset PD (EOPD) and late-onset PD (LOPD) revealed that the polymorphism was not associated with the risk of PD. In conclusion, our meta-analysis suggests that UCHL1 S18Y polymorphism is moderately associated with susceptibility to PD, and more studies are needed to confirm our conclusion. [ABSTRACT FROM AUTHOR]

Aim Levels of ubiquitin carboxyl-terminal hydrolase L1 ( UCHL1) are robustly increased in spinal muscular atrophy ( SMA) patient fibroblasts and mouse models. We therefore wanted to establish whether changes in UCHL1 contribute directly to disease pathogenesis, and to assess whether pharmacological inhibition of UCHL1 represents a viable therapeutic option for SMA. Methods SMA mice and control littermates received a pharmacological UCHL1 inhibitor ( LDN-57444) or DMSO vehicle. Survival and weight were monitored daily, a righting test of motor performance was performed, and motor neurone loss, muscle fibre atrophy and neuromuscular junction pathology were all quantified. Ubiquitin-like modifier activating enzyme 1 ( Uba1) was then pharmacologically inhibited in neurones in vitro to examine the relationship between Uba1 levels and UCHL1 in SMA. Results Pharmacological inhibition of UCHL1 failed to improve survival, motor symptoms or neuromuscular pathology in SMA mice and actually precipitated the onset of weight loss. LDN-57444 treatment significantly decreased spinal cord mono-ubiquitin levels, further exacerbating ubiquitination defects in SMA mice. Pharmacological inhibition of Uba1, levels of which are robustly reduced in SMA, was sufficient to induce accumulation of UCHL1 in primary neuronal cultures. Conclusion Pharmacological inhibition of UCHL1 exacerbates rather than ameliorates disease symptoms in a mouse model of SMA. Thus, pharmacological inhibition of UCHL1 is not a viable therapeutic target for SMA. Moreover, increased levels of UCHL1 in SMA likely represent a downstream consequence of decreased Uba1 levels, indicative of an attempted supportive compensatory response to defects in ubiquitin homeostasis caused by low levels of SMN protein. [ABSTRACT FROM AUTHOR]

Clear cell renal cell carcinoma (CCRCC) is a common renal malignancy known for its lethality and chromosome 3p aberrancies associated with loss of VHL. It has been shown that additional prognostic molecular markers exist in other transcriptional modifiers such as BAP1 and SETD2. Molecular heterogeneity has been described between primary and metastatic sites as well as genetic diversity in spatial tumor analysis; however, morphologic and proteogenomic heterogeneity information is lacking. We assessed 77 nephrectomy specimens with a diagnosis of CCRCC for morphologic architectural patterns including nodular growth patterns and variations in WHO/ISUP grade. Evaluation of highly heterogeneous areas with immunohistochemical (IHC) staining for BAP1, UCHL1, SETD2, and CAIX was performed and correlated with morphologic and histology data. Ultimately, high variability in the morphologic and histological findings matched the complexity of the IHC findings. Alterations in expression of CAIX and UCHL1 correlated with alterations in transcriptional regulators BAP1 and SETD2 within the tumor. High-grade morphology, such as eosinophilia, were areas enriched for alteration of biomarker expression. This highly complex data set of morphologic and biomarker characteristics highlights the heterogeneity of morphology amongst high-grade CCRCC tumors., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Decreased levels of soluble ubiquitin carboxy-terminal hydrolase L1 (UCHL1) have been reported in the brains of sporadic Alzheimer's disease (AD) patients, and the introduction of UCHL1 rescued the synaptic and cognitive function of AD model mice. Obviously, a reduction in the levels of UCHL1 may play a role in the pathogenesis of AD. However, the mechanisms underlying the regulation of UCHL1 levels in AD have not been fully elucidated. MicroRNAs (miRs) have been shown to participate in the process of AD. In our study, we discovered that microRNA-922 decreased the levels of UCHL1. Neurofibrillary tangles (NFTs) mainly consisting of the hyperphosphorylated microtubule-associated protein tau are the defining pathological features of AD. In the present study, we found the levels of UCHL1 affected the levels of phosphorylated tau: the phosphorylated tau levels increased after knockdown of UCHL1 expression, and the phosphorylated tau levels decreased when UCHL1 was overexpressed. Furthermore, overexpression of microRNA-922 increased the phosphorylated tau levels. In conclusion, miR-922 increasing the levels of phosphorylated tau by regulating UCHL1 levels contributed to the pathogenesis of AD. Our study partly explained one of the mechanisms underlying the downregulation of UCHL1 levels in AD patients and could enrich the content of tau pathology in the pathogenesis of AD. [ABSTRACT FROM AUTHOR]

The molecular mechanisms underlying how dietary lactoferrin (Lf) impacts gut development and maturation and protects against early weaning diarrhea are not well understood. In this study, we supplemented postnatal piglets with an Lf at a dose level of 155 and 285 mg/kg/day from 3 to 38 days following birth. Our findings show that the high dose of Lf up-regulated messenger RNA expression levels of genes encoding brain-derived neurotrophic factor ( BDNF ) and ubiquitin carboxy-terminal hydrolase L1 (ubiquitin thiolesterase ( UCHL1 ) and, to a lesser extent, glial cell line-derived neurotrophic factor, in the duodenum ( P <.05). Piglets in the high and low Lf group had 30% and 7% larger jejunal crypts compared with the control group ( P <.05). Escherichia coli 16S rRNA copy number per gram of ascending colon contents was significantly reduced ( P =.001), while the copy number of Bifidobacteria and Lactobacillus spp. was not affected. In addition, Lf increased intestinal alkaline phosphatase activity ( P <.05) and delayed the onset of food transitional diarrhea, reducing its frequency and duration ( P <.05). The incidence of diarrhea in the high and low Lf groups was decreased 54% and 15%, respectively, compared with the control group ( P =.035). In summary, these findings provide new evidence that dietary Lf supplementation up-regulated gene expression of BDNF and UCHL1 , decreased the colon microbiota of E. coli , improved gut maturation and reduced early weaning diarrhea in piglets. The molecular basis underlying these findings suggests that Lf may enhance gut development and immune function by providing new insight into the gut–brain–microbe axis that has not been previously reported. [ABSTRACT FROM AUTHOR]

Abstract: Renal ubiquitin C-terminal hydrolase L1 (UCHL1) is upregulated in a subset of human glomerulopathies, including focal segmental glomerulosclerosis (FSGS), where it may serve to promote ubiquitin pools for degradation of cytotoxic proteins. In the present study, we tested whether UCHL1 is expressed in podocytes of a mouse model of ACTN4-associated FSGS. Podocyte UCHL1 protein was detected in glomeruli of K256E-ACTN4 pod+/UCHL1+/+ mice. UCHL1+/− mice were intercrossed with K256E-ACTN4 pod+ mice and monitored for features of glomerular disease. 10-week-old K256E-ACTN4 pod+/UCHL1−/− mice exhibited significantly ameliorated albuminuria, glomerulosclerosis, tubular pathology and blood pressure. Interestingly, while UCHL1 deletion diminished both tubular and glomerular apoptosis, WT1-positive nuclei were unchanged. Finally, UCHL1 levels correlated positively with poly-ubiquitinated proteins but negatively with K256E-α-actinin-4 levels, implying reduced K256E-α-actinin-4 proteolysis in the absence of UCHL1. Our data suggest that UCHL1 upregulation in ACTN4-associated FSGS fuels the proteasome and that UCHL1 deletion may impair proteolysis and thereby preserve K256E/wt-α-actinin-4 heterodimers, maintaining podocyte cytoskeletal integrity and protecting the glomerular filtration barrier. [Copyright &y& Elsevier]

Highlights: [•] Effect of UCHL1 on CHT expression was examined in a cholinergic neuronal cell line, SN56. [•] TUBE pull-down assay indicated poly-ubiquitination of CHT. [•] CHT immunoprecipitation revealed physical interaction between UCHL1 and CHT. [•] Reduction of UCHL1 by siRNA gene knockdown significantly increased poly-ubiquitinated CHT and decreased native CHT protein level. [•] UCHL1 was present in cytosol and reduction of UCHL1 reduced the cytosolic CHT but not the plasma membrane CHT. [Copyright &y& Elsevier]

The expression of ubiquitin carboxyl-terminal hydrolase 1 (UCHL1) is deregulated in human cancer cells with tumor inhibiting or promoting functions. Due to less knowledge on the role of UCHL1 in melanoma progression, the expression pattern and function of UCHL1 as well as the deregulated signaling pathways were characterized. A large number of melanoma cell lines, tissue microarrays of melanoma lesions and control tissues were analyzed for UCHL1 expression using PCR, Western blot and/or immunohistochemistry. The analysis revealed that melanocyte cultures, 24 of 331 melanoma lesions, two of 18 short-term cultures and two of 19 melanoma cell lines tested, respectively, heterogeneously expressed UCHL1. The low frequency of UCHL1 expression in melanoma cells was due to gene silencing by promoter DNA hypermethylation. Using different transfection models an enzyme activity-dependent growth promoting function of UCHL1 via the activation of the mitogen-activated protein kinase signaling pathway was found in melanoma cells. Under oxygen stress a dose-dependent effect of UCHL1 was detected, which was mediated by a dynamic modification of the PI3K-Akt signaling. Thus, the aberrant UCHL1 expression in melanoma cells is linked to dynamic changes in growth properties and signal transduction cascades suggesting that UCHL1 provides a novel marker and/or therapeutic target at least for a subset of melanoma patients. [ABSTRACT FROM AUTHOR]

Objective: To study the prevalence of spermatogonia in adult subjects with Klinefelter syndrome (KS) using MAGE-A4 and UCHL1 (PGP9.5) immunohistochemistry as markers for undifferentiated spermatogonial cells. We aimed to compare this method to the gold standard of hematoxylin and eosin (H & E) staining with histologic analysis in the largest reported cohort of adult subjects with KS., Design: A retrospective cohort study., Setting: Infertility Clinic and Institute for Regenerative Medicine., Patient(s): This study consisted of 79 adult subjects with KS and 12 adult control subjects., Intervention(s): The subjects with KS (n = 79) underwent bilateral testicular biopsy in an initial effort to recover spermatozoa for in vitro fertilization and intracytoplasmic sperm injection. The institutional review board approved the use of a portion of the archived diagnostic pathology paraffin blocks for the study. The samples were superimposed onto microscopic slides and labeled with the PGP9.5 and MAGE-A4 antibodies. Subjects (n = 12) who had previously consented to be organ donors via the National Disease Research Interchange were selected as controls. Dedicated genitourinary pathologists examined the H & E-, PGP9.5-, and MAGE-A4-stained tissue for presence of undifferentiated spermatogonia and spermatozoa with the use of a virtual microscopy software., Main Outcome Measure(s): The primary outcome was the presence of MAGE-A4-positive or UCHL1-positive tubules that indicate undifferentiated spermatogonia. Supportive outcomes include assessing the biopsy specimen for the following: total surface area; total seminiferous tubule surface area; total interstitium surface area; the total number of seminiferous tubules; and MAGE-A4- negative or UCHL1-negative tubules. Additionally, clinical information, such as age, karyotype, height, weight, mean testicle size, and hormonal panel (luteinizing hormone, follicle-stimulating hormone, and testosterone), was obtained and used in a single and multivariable analysis with linear regression to determine predictive factors for the number of UCHL1-positive tubules., Result(s): The mean age of the subjects in the KS group was 32.9 ± 0.7 years (range, 16-48). UCHL1 (PGP9.5) and MAGE-A4 staining showed that 74.7% (n = 59) and 40.5% (n = 32) of the subjects with KS, respectively, were positive for undifferentiated spermatogonia compared with 100% (n = 12) of the control subjects who were positive for both the markers. Hematoxylin and eosin with microscopic analysis showed that only 10.1% (n = 8) of the subjects were positive for spermatogonia. The mean number of positive tubules per subject with KS was 11.8 ± 1.8 for UCHL1 and 3.7 ± 1.0 for MAGE-A4. Secondary analysis showed 7 (8.9%) adult subjects with KS as positive for spermatozoa on biopsy. The population having negative testicular sperm extraction results (n = 72) showed a spermatogonia-positive rate of 1.4%, (n = 1), 72.2% (n = 52), and 34.7% (n = 25) using H & E, UCHL1, and MAGE-A4, respectively. Further analysis showed that 54 (75.0%) subjects were either positive for UCHL1 or MAGE-A4. Twenty (27.8%) subjects were positive for both UCHL1 and MAGE-A4. Multivariate analysis with linear regression showed no significant correlation between clinical variables and the number of UCHL1-positive tubules found on biopsy specimens., Conclusion(s): We report a cohort of adult subjects with KS undergoing analysis for the presence of undifferentiated spermatogonia. UCHL1 and MAGE-A4 immunostaining appear to be an effective way of identifying undifferentiated spermatogonia in testicular biopsy specimens of subjects with KS. Despite observing deterioration in the testicular architecture, many patients remain positive for undifferentiated spermatogonia, which could be harvested and potentially used for infertility therapy in a patient with KS who is azoospermic and has negative testicular sperm extraction results., (Copyright © 2022 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)