Role Of Ubiquitin C-terminal Hydrolase L1 Research Articles

Ubiquitin C‑terminal hydrolase‑L1: A new cancer marker and therapeutic target with dual effects (Review).

Ubiquitin C-terminal hydrolase-L1 (UCH-L1), a member of the lesser-known deubiquitinating enzyme family, has deubiquitinase and ubiquitin (Ub) ligase activity and the role of stabilizing Ub. UCH-L1 was first discovered in the brain and is associated with regulating cell differentiation, proliferation, transcriptional regulation and numerous other biological processes. UCH-L1 is predominantly expressed in the brain and serves a role in tumor promotion or inhibition. There is still controversy about the effect of UCH-L1 dysregulation in cancer and its mechanisms are unknown. Extensive research to investigate the mechanism of UCH-L1 in different types of cancer is key for the future treatment of UCH-L1-associated cancer. The present review details the molecular structure and function of UCH-L1. The role of UCH-L1 in different types of cancer is also summarized and how novel treatment targets provide a theoretical foundation in cancer research is discussed.

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.

The requirement of ubiquitin C-terminal hydrolase L1 in mouse ovarian development and fertility†.

Ubiquitin C-terminal hydrolase L1 (UCHL1) is a de-ubiquitinating enzyme enriched in neuronal and gonadal tissues known to regulate the cellular stores of mono-ubiquitin and protein turnover. While its function in maintaining proper motor neuron function is well established, investigation into its role in the health and function of reproductive processes is only just beginning to be studied. Single-cell-sequencing analysis of all ovarian cells from the murine perinatal period revealed that Uchl1 is very highly expressed in the developing oocyte population, an observation which was corroborated by high levels of oocyte-enriched UCHL1 protein expression in oocytes of all stages throughout the mouse reproductive lifespan. To better understand the role UCHL1 may be playing in oocytes, we utilized a UCHL1-deficient mouse line, finding reduced number of litters, reduced litter sizes, altered folliculogenesis, morphologically abnormal oocytes, disrupted estrous cyclicity and apparent endocrine dysfunction in these animals compared to their wild-type and heterozygous littermates. These data reveal a novel role of UCHL1 in female fertility as well as overall ovarian function, and suggest a potentially essential role for the ubiquitin proteasome pathway in mediating reproductive health.

Ubiquitin C-Terminal Hydrolase L1 is required for regulated protein degradation through the ubiquitin proteasome system in kidney

Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a major deubiquitinating enzyme of the nervous system and associated with the development of neurodegenerative diseases. We have previously shown that UCH-L1 is found in tubular and parietal cells of the kidney and is expressed de novo in injured podocytes. Since the role of UCH-L1 in the kidney is unknown we generated mice with a constitutive UCH-L1-deficiency to determine its role in renal health and disease. UCH-L1-deficient mice developed proteinuria, without gross changes in glomerular morphology. Tubular cells, endothelial cells, and podocytes showed signs of stress with an accumulation of oxidative-modified and polyubiquitinated proteins. Mechanistically, abnormal protein accumulation resulted from an altered proteasome abundance leading to decreased proteasomal activity, a finding exaggerated after induction of anti-podocyte nephritis. UCH-L1-deficient mice exhibited an exacerbated course of disease with increased tubulointerstitial and glomerular damage, acute renal failure, and death, the latter most likely a result of general neurologic impairment. Thus, UCH-L1 is required for regulated protein degradation in the kidney by controlling proteasome abundance. Altered proteasome abundance renders renal cells, particularly podocytes and endothelial cells, susceptible to injury.

Absence of UCHL 1 function leads to selective motor neuropathy.

ObjectiveThe aim of this study was to investigate the role of ubiquitin C‐terminal hydrolase‐L1 (UCHL1) for motor neuron circuitry and especially in spinal motor neuron (SMN) health, function, and connectivity.MethodsSince mutations in UCHL1 gene leads to motor dysfunction in patients, we investigated the role of UCHL1 on SMN survival, axon health, and connectivity with the muscle, by employing molecular and cellular marker expression analysis and electrophysiological recordings, in healthy wild‐type and Uchl1 nm3419 (UCHL1−/−) mice, which lack all UCHL1 function.ResultsThere is pure motor neuropathy with selective degeneration of the motor, but not sensory axons in the absence of UCHL1 function. Neuromuscular junctions (NMJ) are impaired in muscle groups that are innervated by slow‐twitch or fast‐twitch SMN. However, unlike corticospinal motor neurons, SMN cell bodies remain intact with no signs of elevated endoplasmic reticulum (ER) stress.InterpretationPresence of NMJ defects and progressive retrograde axonal degeneration in the absence of major SMN soma loss suggest that defining pathology as a function of neuron number is misleading and that upper and lower motor neurons utilize UCHL1 function in different cellular events. In line with findings in patients with mutations in UCHL1 gene, our results suggest a unique role of UCHL1, especially for motor neuron circuitry. SMN require UCHL1 to maintain NMJ and motor axon health, and that observed motor dysfunction in the absence of UCHL1 is not due to SMN loss, but mostly due to disintegrated circuitry.

Abstract 3559: Ubiquitin C-terminal hydrolase L1 (UCHL1) modulates uterine papillary serous cancer progression through interaction with cyclin B1

Abstract Background: Uterine papillary serous carcinoma (UPSC) comprises less than 10% of all endometrial cancers but accounts for a disproportionately high number of deaths. Few prospective studies focus solely on this aggressive subtype, making it difficult to determine optimal treatment strategies. The purpose of this study was therefore to identify novel therapeutic targets that could aid in the management of UPSC. Methods: Clinical and RNA sequencing data from The Cancer Genome Atlas (TCGA) was used to identify genes that were differentially expressed between endometrioid endometrial carcinoma (EEC) and UPSC, which also showed a significant association with overall patient survival duration in UPSC patients. Ubiquitin C-terminal hydrolase L1 (UCHL1) upregulation and correlation with survival was validated by immunohistochemical staining of an independent cohort of paraffin samples. UCHL1 was silenced by siRNA transfection and lentiviral shRNA transduction in UPSC cell lines ARK1, ARK2 and HEC50 to evaluate the role of UCHL1 on cell proliferation, migration and cell cycle progression. RPPA data from TCGA was used to identify proteins whose expression correlated with UCHL1 expression. Interaction between UCHL1 and cyclin B1 was determined by co-immunoprecipitation. The effect of UCHL1 silencing on cyclin B1 levels was evaluated by Western blot analysis, and the effect on cell cycle progression was determined by flow cytometry. Results: UCHL1 mRNA and protein expression levels were significantly higher in in UPSC compared to EEC. Kaplan-Meier analysis and cox regression of the TCGA data set and an independent cohort of patient samples revealed that UCHL1 expression correlated significantly with poorer overall survival in UPSC, especially in late-stage patients. siRNA-mediated silencing did not affect cell migration, but reduced the proliferation rates of ARK1, ARK2 and HEC50 in vitro. UCHL1 RNA expression was positively correlated with cyclin B1 protein levels in the TCGA data set. Accordingly, UCHL1 silencing reduced cyclin B1 protein but not mRNA expression levels in ARK1, ARK2 and HEC50. Cell cycle analysis of ARK1, ARK2 and HEC50 after UCHL1 silencing showed a reduction in the percentage of cells in the S and G2/M phases, with or without cell synchronization. Conclusion: These findings indicate that UCHL1 contributes to the aggressiveness of UPSC by stabilizing cyclin B1 and increasing cell proliferation, suggesting that it may be a therapeutic target for UPSC. Citation Format: Suet Ying Kwan, Samuel C. Mok, Kwong-Kwok Wong, Rosemarie E. Schmandt, Karen H. Lu. Ubiquitin C-terminal hydrolase L1 (UCHL1) modulates uterine papillary serous cancer progression through interaction with cyclin B1. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3559. doi:10.1158/1538-7445.AM2015-3559

Ubiquitin C-terminal hydrolase-L1 increases cancer cell invasion by modulating hydrogen peroxide generated via NADPH oxidase 4.

This study explored the role of ubiquitin C-terminal hydrolase-L1 (UCH-L1) in the production of ROS and tumor invasion. UCH-L1 was found to increase cellular ROS levels and promote cell invasion. Silencing UCH-L1, as well as inhibition of H2O2 generation by catalase or by DPI, a NOX inhibitor, suppressed the migration potential of B16F10 cells, indicating that UCH-L1 promotes cell migration by up-regulating H2O2 generation. Silencing NOX4, which generates H2O2, with siRNA eliminated the effect of UCH-L1 on cell migration. On the other hand, NOX4 overexpressed in HeLa cells happens to be ubiquitinated, and NOX4 following deubiquitination by UCH-L1, restored H2O2-generating activity. These in vitro findings are consistent with the results obtained in vivo with catalase (-/-) C57BL/6J mice. When H2O2 and UCH-L1 levels were independently varied in these animals, the former by infecting with H2O2-scavenging adenovirus-catalase, and the latter by overexpressing or silencing UCH-L1, pulmonary metastasis of B16F10 cells overexpressing UCH-L1 increased significantly in catalase (-/-) mice. In contrast, invasion did not increase when UCH-L1 was silenced in the B16F10 cells. These findings indicate that H2O2 levels regulated by UCH-L1 are necessary for cell invasion to occur and demonstrate that UCH-L1 promotes cell invasion by up-regulating H2O2 via deubiquitination of NOX4.

Effects of ubiquitin C-terminal hydrolase L1 deficiency on mouse ova

Maternal proteins are rapidly degraded by the ubiquitin-proteasome system during oocyte maturation in mice. Ubiquitin C-terminal hydrolase L1 (UCHL1) is highly and specifically expressed in mouse ova and is involved in the polyspermy block. However, the role of UCHL1 in the underlying mechanism of polyspermy block is poorly understood. To address this issue, we performed a comprehensive proteomic analysis to identify maternal proteins that were relevant to the role of UCHL1 in mouse ova using UCHL1-deficient gad. Furthermore, we assessed morphological features in gad mouse ova using transmission electron microscopy. NACHT, LRR, and PYD domain-containing (NALP) family proteins and endoplasmic reticulum (ER) chaperones were identified by proteomic analysis. We also found that the 'maternal antigen that embryos require' (NLRP5 (MATER)) protein level increased significantly in gad mouse ova compared with that in wild-type mice. In an ultrastructural study, gad mouse ova contained less ER in the cortex than in wild-type mice. These results provide new insights into the role of UCHL1 in the mechanism of polyspermy block in mouse ova.

Role of Ubiquitin C-Terminal Hydrolase-L1 in Antipolyspermy Defense of Mammalian Oocytes1

The ubiquitin-proteasome system regulates many cellular processes through rapid proteasomal degradation of ubiquitin-tagged proteins. Ubiquitin C-terminal hydrolase-L1 (UCHL1) is one of the most abundant proteins in mammalian oocytes. It has weak hydrolytic activity as a monomer and acts as a ubiquitin ligase in its dimeric or oligomeric form. Recently published data show that insufficiency in UCHL1 activity coincides with polyspermic fertilization; however, the mechanism by which UCHL1 contributes to this process remains unclear. Using UCHL1-specific inhibitors, we induced a high rate of polyspermy in bovine zygotes after in vitro fertilization. We also detected decreased levels in the monomeric ubiquitin and polyubiquitin pool. The presence of UCHL1 inhibitors in maturation medium enhanced formation of presumptive UCHL1 oligomers and subsequently increased abundance of K63-linked polyubiquitin chains in oocytes. We analyzed the dynamics of cortical granules (CGs) in UCHL1-inhibited oocytes; both migration of CGs toward the cortex during oocyte maturation and fertilization-induced extrusion of CGs were impaired. These alterations in CG dynamics coincided with high polyspermy incidence in in vitro-produced UCHL1-inhibited zygotes. These data indicate that antipolyspermy defense in bovine oocytes may rely on UCHL1-controlled functioning of CGs.