BAP1 regulates HSF1 activity and cancer immunity in pancreatic cancer.

BACKGROUND: The vast majority of pancreatic cancers have been shown to be insensitive to single-agent immunotherapy. Exploring the mechanisms of immune resistance and implementing combination therapeutic strategies are crucial for PDAC patients to derive benefits from immunotherapy. Deletion of BAP1 occurs in approximately 27% of PDAC patients and is significantly correlated with poor prognosis, but the mechanism how BAP1-deletion compromises survival of patients with PDAC remain a puzzle. METHODS: Bap1 knock-out KPC (KrasG12D/+; LSLTrp53R172H/+; Pdx-1-Cre) mice and control KPC mice, syngeneic xenograft models were applied to analysis the correlation between BAP1 and immune therapy response in PDAC. Immunoprecipitation, RT-qPCR, luciferase and transcriptome analysis were combined to revealing potential mechanisms. Syngeneic xenograft models and flow cytometry were constructed to examine the efficacy of the inhibitor of SIRT1 and its synergistic effect with anti-PD-1 therapy. RESULT: The deletion of BAP1 contributes to the resistance to immunotherapy in PDAC, which is attributable to BAP1's suppression of the transcriptional activity of HSF1. Specifically, BAP1 competes with SIRT1 for binding to the K80 acetylated HSF1. The BAP1-HSF1 interaction preserves the acetylation of HSF1-K80 and promotes HSF1-HSP70 interaction, facilitating HSF1 oligomerization and detachment from the chromatin. Furthermore, we demonstrate that the targeted inhibition of SIRT1 reverses the immune insensitivity in BAP1 deficient PDAC mouse model. CONCLUSION: Our study elucidates an unrevealed mechanism by which BAP1 regulates immune therapy response in PDAC via HSF1 inhibition, and providing promising therapeutic strategies to address immune insensitivity in BAP1-deficient PDAC.

Inhibition of Ubiquitin C-Terminal Hydrolase L1 Facilitates Cutaneous Wound Healing via Activating TGF-ß/Smad Signalling Pathway in Fibroblasts.

Ubiquitin C-terminal hydrolase L1 (UCHL1) plays vital roles in cell proliferation, angiogenesis, inflammation and oxidative stress. Nevertheless, it is unclear whether UCHL1 could regulate the biologic behaviour of cells and ultimately influences wound healing. We aim to illustrate the roles and the underlying mechanism of UCHL1 in cutaneous wound healing. Murine full-thickness excisional wound model was utilised to study the effects of UCHL1 on wound healing through topical administration of the UCHL1 inhibitor LDN57444, followed by assessment of wound areas and histological alterations. Subsequently, ethynyldeoxyuridine, scratch and transwell assays were performed to examine fibroblast migration and proliferation. The extracellular matrix (ECM)-related genes expression and transforming growth factor-ß (TGF-ß)/Smad signalling pathways activation were investigated by immuno-fluorescent staining, Western blots and quantitative reverse transcription polymerase chain reaction. We identified elevated UCHL1 expression in non-healing wound tissues. The UCHL1 expression displayed a dynamic change and reached a peak on Day-7 post-wounding during the healing process in mice. Cutaneous administration of LDN57444 promoted wound healing by facilitating collagen deposition, myofibroblast activation and angiogenesis. In vitro experiments demonstrated that UCHL1 concentration dependently inhibited migration, ECM synthesis and activation of human dermal fibroblasts, which was mechanistically related to downregulation of TGF-ß/Smad signalling. Furthermore, these effects could be reversed by TGF-ß inhibitor SB431542. Our findings reveal that UCHL1 is a negative regulator of cutaneous wound healing and considered as a novel prospective therapeutic target for effective wound healing.

[Uveal Melanoma: Molecular and Genetic Mechanisms of Development and Therapeutic Approaches].

Uveal melanoma (UM) is a neuroectodermal tumor that results from malignant transformation of melanocytes in the eye uvea, including the iris, the ciliary body, and the choroid. UM accounts for 5% of all melanoma cases and is extremely aggressive with half of the UM patients developing metastases within the first 1-2 years after tumor development. Molecular mechanisms of UM carcinogenesis are poorly understood, but are known to differ from those of skin melanoma. Activating mutations of the GNAQ and GNA11 genes, which code for the large G protein subunits Gq and G11, respectively, are found in 90% of UM patients. The Gaq/PKC/MAPK signaling pathway is a main signaling cascade that leads to the transformation of melanocytes of the uveal tract, and major regulators of the cascade provide targets for the development of drugs. Metastatic UM (MUM) is most often associated with mutations of BAP1, EIF1AX, GNA11, GNAQ, and SF3B1. A combination of a commercial expression test panel of 15 genes and a mutation panel of 7 genes, supplemented with data on the size of the primary tumor, is highly efficient in predicting the risk of metastasis. The risk of metastasis determines the choice of therapy and the patient follow-up regimen. However, no systemic therapy for MUM has been developed to date. New drugs undergoing clinical trials are mostly targeted drugs designed to inhibit the protein products of mutant genes or immunotherapeutic agents designed to stimulate the immune response against specific antigens. In addition to these approaches, potential therapeutic targets of epigenetic regulation of UM development are considered in the review.

KLF15 suppresses stemness of pancreatic cancer by decreasing USP21-mediated Nanog stability.

The existence of cancer stem cells (CSCs) in pancreatic ductal adenocarcinoma (PDAC) is considered to be the key factor for metastasis and chemoresistance. Thus, novel therapeutic strategies for eradicating CSCs are urgently needed. Here we aimed to explore the role of KLF15 in stemness and the feasibility of using KLF15 to inhibit CSCs and improve chemotherapy sensitivity in PDAC. In this study, we report that KLF15 is negatively associated with poor survival and advanced pathological staging of PDAC. Moreover, tumorous KLF15 suppresses the stemness of PDAC by promoting the degradation of Nanog, and KLF15 directly interacts with Nanog, inhibiting interaction between Nanog with USP21. We also demonstrate that the KLF15/Nanog complex inhibit the stemness in vivo and in PDX cells. Tazemetostat suppresses stemness and sensitizes PDAC cells to gemcitabine by promoting KLF15 expression in PDAC. In summary, the findings of our study confirm the value of KLF15 level in diagnosis and prognosis of PDAC, it is the first time to explore the inhibition role of KLF15 in stemness of PDAC and the regulation mechanism of Nanog, contributing to provide a new therapeutic strategy that using Tazemetostat sensitizes PDAC cells to gemcitabine by promoting KLF15 expression for PDAC.

The Impact of Spliceosome Inhibition in SF3B1-Mutated Uveal Melanoma.

Purpose: Unfortunately, treatment of patients with uveal melanoma (UM) with metastatic disease is limited. Twenty percent of patients with UM harbor a mutation in the splicing factor gene SF3B1, suggesting that aberrant spliceosome function plays a vital role in tumorigenesis. Splicing inhibitors exploit the preferential sensitivity of spliceosome-compromised leukemic cells to these compounds. Methods: We studied the effect of the splicing inhibitor E7107 using two UM cell lines and ex vivo cultured SF3B1- and BAP1-mutated primary UM tumor slices. These UM cell lines and ex vivo tumor slices were exposed for 24 hours to different concentrations of E7107. Tumor slices were stained with hematoxylin and eosin (H&E) and incubated with BAP1, MelanA, MIB-1, and caspase-3 antisera. Results: The E7107-exposed UM cell lines exhibited decreased cell viability and increased apoptosis, with the greatest effect on SF3B1-mutated UM cells. A similar effect on UM tumor slices was observed upon exposure to E7107. Additionally, RNA was isolated for differential isoform expression analysis. No significant difference in isoform usage was found genome-wide. However, specific genes were differentially expressed after E7107 treatment in the SF3B1-mutated samples. Moreover, E7107 had the greatest effect on intron retention. Conclusions: This study indicates/suggests that mutated SF3B1 UM cells are more sensitive to the splicing inhibitor E7107 than wild-type SF3B1 UM cells.

Characterization of somatic mutations in sporadic uveal melanoma and uveal melanoma in patients with germline BAP1 pathogenic variants.

Genetic analyses were conducted on tumor samples from 88 patients with uveal melanoma (UM), 6 of whom carry pathogenic germline variants in BAP1. We assessed the frequency, pattern, and prognostic significance of somatic aberrations, and investigated differences between germline BAP1 variant carriers compared to sporadic cases. The frequency of the main oncogenic driver mutations was not significantly different between these groups. Patients with germline BAP1 variants did not have significantly different overall survival compared to the wildtype or somatic BAP1 mutation groups. Patients with a somatic BAP1 mutation (n = 24) had a significantly worse prognosis compared to wildtype (n = 58). All patients with stage III tumors and a somatic BAP1 mutation (n = 7) developed metastasis, however four of 28 stage I-II tumors without metastasis had somatic BAP1 mutations, with observation time >5 years. The tumor from one germline BAP1 carrier (stage IIIC) with a somatic EIF1AX splice variant, has not developed metastasis within a 22-year observation time.

USP24 promotes autophagy-dependent ferroptosis in hepatocellular carcinoma by reducing the K48-linked ubiquitination of Beclin1.

Ubiquitination is a post-translational modification (PTM), which is critical to maintain cell homeostasis. Ubiquitin-specific protease 24 (USP24) plays roles in various diseases, the mechanisms by which USP24 regulates hepatocellular carcinoma (HCC) remain poorly understood. In this study, USP24 is found to be significantly downregulated in HCC. Knocking down USP24 promotes HCC proliferation and migration, whereas USP24 overexpression inhibits HCC in vitro and in vivo. The endogenous interaction between USP24 and Beclin1 is confirmed. Mechanically, USP24 delays Beclin1 degradation by reducing its K48-linked ubiquitination, the effects of overexpressing USP24 on HCC proliferation can be partially reversed by silencing Beclin1. We find that increased autophagy is accompanied by ferroptosis in USP24 overexpressed HCC cells and USP24 increases the susceptibility of HCC to sorafenib. Collectively, this study highlights the critical role of USP24 in regulating autophagy-dependent ferroptosis by decreasing Beclin1 ubiquitination, suggesting that targeting USP24 may be a strategy for treating HCC.

A RANKL-UCHL1-sCD13 negative feedback loop limits osteoclastogenesis in subchondral bone to prevent osteoarthritis progression.

Abnormal subchondral bone remodeling plays a pivotal role in the progression of osteoarthritis (OA). Here, we analyzed subchondral bone samples from OA patients and observed a significant upregulation of ubiquitin carboxy-terminal hydrolase L1 (UCHL1) specifically in subchondral bone osteoclasts. Notably, we found a strong correlation between UCHL1 expression and osteoclast activity in the subchondral bone during OA progression in both human and murine models. Conditional UCHL1 deletion in osteoclast precursors exacerbated OA progression, while its overexpression, mediated by adeno-associated virus 9, alleviated this process in male mice. Mechanistically, RANKL stimulates UCHL1 expression in osteoclast precursors, subsequently stabilizing CD13, augmenting soluble CD13 (sCD13) release, and triggering an autocrine inhibitory effect on the MAPK pathway, thereby suppressing osteoclast formation. These findings unveil a previously unidentified negative feedback loop, RANKL-UCHL1-sCD13, that modulates osteoclast formation and presents a potential therapeutic target for OA.

USP10 promotes cell proliferation, migration, and invasion in NSCLC through deubiquitination and stabilization of EIF4G1.

Lung cancer is one of the most common types of malignant cancer worldwide, causing a serious social and economic burden. It is classified into non-small cell lung cancer (NSCLC) and small cell lung cancer, with NSCLC accounting for 80-85% of cases. Eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) is highly expressed in NSCLC, playing an important role in regulating tumor growth, angiogenesis, malignant transformation, and phagocytosis. Ubiquitin-specific protease 10 (USP10) functions as a deubiquitinating enzyme to regulate substrate protein deubiquitination and reverse the ubiquitin proteasome degradation pathway. Our previous study identified an interaction between EIF4G1 and USP10; however, their regulatory mechanism remains unclear. Herein, we found that USP10 positively regulates EIF4G1 in NSCLC cells. An in vivo ubiquitination assay demonstrated deubiquitination of EIF4G1 by USP10, which reversed the ubiquitin proteasomal degradation of EIF4G1, thereby increasing its stability. Upregulation of EIF4G1 promoted cell proliferation, migration, and invasion in NSCLC cells. The current study not only reveals a novel mechanism through which USP10 positively regulates EIF4G1 in NSCLC, but also demonstrates the potential of USP10 as a therapeutic target to treat NSCLC.

Recruitment of USP10 by GCS1 to deubiquitinate GRP78 promotes the progression of colorectal cancer via alleviating endoplasmic reticulum stress.

BACKGROUND: Long-term accumulation of misfolded proteins leads to endoplasmic reticulum (ER) stress in colorectal cancer (CRC). However, the precise pathways controlling the decision between survival and apoptosis in CRC are unclear. Therefore, in this study, we investigated the function and molecular mechanism of glucosidase I (GCS1) in regulating ER stress in CRC. METHODS: A public database was used to confirm the expression level of GCS1 in CRC and normal tissues. Clinical samples from our center were used to confirm the mRNA and protein expression levels of GCS1. Cell proliferation, migration, invasion, and apoptosis assays revealed the biological role of GCS1. Immunohistochemical techniques were used to evaluate the expression of key proteins in subcutaneous implanted tumors in nude mice, which provided further evidence for the biological function of GCS1 in promoting cancer in vivo. The results of coimmunoprecipitation-mass spectrometry analysis and immunofluorescence colocalization analysis the interaction between GCS1 and GRP78. In addition, the mechanism of action of USP10, GRP78, and GCS1 at the post- translational level was investigated. Finally, a tissue microarray was used to examine the connection between GCS1 and GRP78 expression and intracellular localization of these proteins using immunohistochemistry and immunofluorescence. RESULTS: The experimental results revealed that GCS1 was substantially expressed in CRC, with higher expression indicating a worse prognosis. Thus, GCS1 can enhance the proliferation and metastasis while inhibiting the apoptosis of CRC cells both in vivo and in vitro. Mechanistically, GCS1 binds to GRP78, recruits USP10 for deubiquitination of GRP78 to promote its degradation, and decreases ER stress-mediated apoptosis, increasing CRC cell proliferation and metastasis. CONCLUSIONS: In summary, GCS1 stimulates CRC growth and migration and reduces ER stress-mediated apoptosis via USP10-mediated deubiquitination of GRP78. Our findings identify a possible therapeutic target for CRC.

NDR1 mediates PD-L1 deubiquitination to promote prostate cancer immune escape via USP10.

Prostate cancer (PCa) is one of the most common male genitourinary system malignancies. Despite the significant benefits of anti-PD-L1 immune checkpoint inhibitor therapy in other cancers, the reasons for its poor therapeutic efficacy in prostate cancer (PCa) remain unclear.NDR1 plays an important role in innate immunity, but its role in tumor immunity and immunotherapy has not been investigated. The role of NDR1 in the immune microenvironment of PCa and the related mechanisms are unknown. Here, we found a positive correlation between NDR1 and PD-L1 expression in PCa. NDR1 significantly inhibits CD8 + T cell infiltration and function, thereby promoting immune escape in prostate cancer.More importantly, NDR1 inhibition significantly enhanced CD8 + T cell activation, which enhanced the therapeutic effect of anti-PD-L1. Mechanistic studies revealed that NDR1 inhibits ubiquitination-mediated PD-L1 degradation via the deubiquitinase USP10, upregulates PD-L1, and promotes PCa immune escape. Thus, our study suggests a unique PD-L1 regulatory mechanism underlying PCa immunotherapy failure. The significance of NDR1 in PCa immune escape and its mechanism of action were clarified, and combined NDR1/PD-L1 inhibition was suggested as an approach to boost PCa immunotherapy effectiveness.

Deubiquitinating enzyme USP28 inhibitor AZ1 alone and in combination with cisplatin for the treatment of non-small cell lung cancer.

Lung cancer is one of the most common malignant tumors. Despite decades of research, the treatment of lung cancer remains challenging. Non-small cell lung cancer (NSCLC) is the primary type of lung cancer and is a significant focus of research in lung cancer treatment. The deubiquitinase ubiquitin-specific protease 28 (USP28) plays a role in the progression of various tumors and serves as a potential therapeutic target. This study aims to determine the role of USP28 in the progression of NSCLC. We examined the impact of the USP28 inhibitor AZ1 on the cell cycle, apoptosis, DNA damage response, and cellular immunogenicity in non-small cell lung cancer. We observed that AZ1 and siUSP28 induce DNA damage, leading to the activation of Noxa-mediated mitochondrial apoptosis. The dsDNA and mtDNA released from DNA damage and mitochondrial apoptosis activate tumor cell immunogenicity through the cGAS-STING signaling pathway. Simultaneously, targeting USP28 promotes the degradation of c-MYC, resulting in cell cycle arrest and inhibition of DNA repair. This further promotes DNA damage-induced cell apoptosis mediated by the Noxa protein, thereby enhancing tumor cell immunogenicity mediated by dsDNA and mtDNA. Moreover, we found that the combination of AZ1 and cisplatin (DDP) can enhance therapeutic efficacy, thereby providing a new strategy to overcome cisplatin resistance in NSCLC. These findings suggest that targeting USP28 and combining it with cisplatin are feasible strategies for treating NSCLC.

USP18 Is Associated with PD-L1 Antitumor Immunity and Improved Prognosis in Colorectal Cancer.

BACKGROUND: Compared with conventional chemotherapy and targeted therapy, immunotherapy has improved the treatment outlook for a variety of solid tumors, including lung cancer, colorectal cancer (CRC), and melanoma. However, it is effective only in certain patients, necessitating the search for alternative strategies to targeted immunotherapy. The deubiquitinating enzyme USP18 is known to play an important role in various aspects of the immune response, but its role in tumor immunity in CRC remains unclear. METHODS: In this study, multiple online datasets were used to systematically analyze the expression, prognosis, and immunomodulatory role of USP18 in CRC. The effect of USP18 on CRC was assessed via shRNA-mediated knockdown of USP18 expression in combination with CCK-8 and colony formation assays. Finally, molecular docking analysis of USP18/ISG15 and programmed death-ligand 1 (PD-L1) was performed via HDOCK, and an ELISA was used to verify the potential of USP18 to regulate PD-L1. RESULTS: Our study revealed that USP18 expression was significantly elevated in CRC patients and closely related to clinicopathological characteristics. The experimental data indicated that silencing USP18 significantly promoted the proliferation and population-dependent growth of CRC cells. In addition, high USP18 expression was positively correlated with the CRC survival rate and closely associated with tumor-infiltrating CD8+ T cells and natural killer (NK) cells. Interestingly, USP18 was correlated with the expression of various chemokines and immune checkpoint genes. The results of molecular docking simulations suggest that USP18 may act as a novel regulator of PD-L1 and that its deficiency may potentiate the antitumor immune response to PD-L1 blockade immunotherapy in CRC. CONCLUSIONS: In summary, USP18 shows great promise for research and clinical application as a potential target for CRC immunotherapy.

The deubiquitinase Ubp3/Usp10 constrains glucose-mediated mitochondrial repression via phosphate budgeting.

Many cells in high glucose repress mitochondrial respiration, as observed in the Crabtree and Warburg effects. Our understanding of biochemical constraints for mitochondrial activation is limited. Using a Saccharomyces cerevisiae screen, we identified the conserved deubiquitinase Ubp3 (Usp10), as necessary for mitochondrial repression. Ubp3 mutants have increased mitochondrial activity despite abundant glucose, along with decreased glycolytic enzymes, and a rewired glucose metabolic network with increased trehalose production. Utilizing ∆ubp3 cells, along with orthogonal approaches, we establish that the high glycolytic flux in glucose continuously consumes free Pi. This restricts mitochondrial access to inorganic phosphate (Pi), and prevents mitochondrial activation. Contrastingly, rewired glucose metabolism with enhanced trehalose production and reduced GAPDH (as in ∆ubp3 cells) restores Pi. This collectively results in increased mitochondrial Pi and derepression, while restricting mitochondrial Pi transport prevents activation. We therefore suggest that glycolytic flux-dependent intracellular Pi budgeting is a key constraint for mitochondrial repression.

RNA binding protein ELAVL1-mediated USP33 stabilizes HIF1A to promote pathological proliferation, migration and angiogenesis of RECs.

BACKGROUND: Dysfunction of retinal vascularization plays pathogenic roles in retinopathy of prematurity (ROP). Hypoxia-inducible factor 1 alpha (HIF1A) is activated by hypoxia and contributes to ROP progression. Herein, we clarified the mechanism underlying HIF1A activation in human retinal vascular endothelial cells (HRECs) under hypoxia. METHODS: Protein expression was assayed by immunoblot analysis. Cell migration, microtubule formation, invasion, proliferation, and viability were detected by wound-healing, tube formation, transwell, EdU, and CCK-8 assays, respectively. Bioinformatics was used to predict the deubiquitinase-HIF1A interactions and RNA binding proteins (RBPs) bound to USP33. The impact of USP33 on HIF1A deubiquitination was validated by immunoprecipitation (IP) assay. RNA stability analysis was performed with actinomycin D (Act D) treatment. The ELAVL1/USP33 interaction was assessed by RNA immunoprecipitation experiment. RESULTS: In hypoxia-exposed HRECs, HIF1A and USP33 protein levels were upregulated. Deficiency of HIF1A or USP33 suppressed cell migration, proliferation and microtubule formation of hypoxia-exposed HRECs. Mechanistically, USP33 deficiency led to an elevation in HIF1A ubiquitination and degradation. USP33 deficiency reduced HIF1A protein levels to suppress the proliferation and microtubule formation of hypoxia-induced HRECs. Moreover, the RBP ELAVL1 stabilized USP33 mRNA to increase USP33 protein levels. ELAVL1 decrease repressed the proliferation and microtubule formation of hypoxia-induced HRECs by reducing USP33. CONCLUSION: Our study identifies a novel ELAVL1/USP33/HIF1A regulatory cascade with the ability to affect hypoxia-induced pathological proliferation, angiogenesis, and migration in HRECs.

Deubiquitinase USP14 is upregulated in Crohn's disease and inhibits the NOD2 pathway mediated inflammatory response in vitro.

The nucleotide binding oligomerization domain containing 2 (NOD2) protein and its ligand N-acetyl muramyl dipeptide (MDP) are crucially involved in Crohn's disease (CD). However, the mechanism by which NOD2 signaling is regulated in CD patients remains unclear. Ubiquitin specific protease (USP14) is a deubiquitylase that plays an important role in immunity. This study aimed to investigate the mechanism by which UPS14 regulates NOD2 induced inflammatory response in CD and inflammatory bowel diseases (IBD). Our results showed that USP14 protein and mRNA levels in intestinal tissues of CD patients were significantly higher than those in healthy controls. In addition, USP14 was upregulated in IBD mouse model. While treatment with MDP, TNF-α or the Toll-like receptor 1/2 agonist Pam3CSK4 all led to significantly higher mRNA levels of TNF-α, IL-8 and IL-1ß in THP-1 cells, pretreatment with USP14 inhibitor IU1 could stimulate further upregulation of TNF-α, IL-8 and IL-1ß. In particular, MDP promoted the activation of JNK, ERK1/2 and p38 as well as NF-kB in THP-1 cells, and IU1 significantly enhanced the MDP-induced activation of these proteins without effects on USP14 protein level. Furthermore, the JNK inhibitor sp600125, ERK1/2 inhibitor U0126 or P38 MAPK inhibitor PD169316 significantly decreased the mRNA levels of TNF-α, IL-8 and IL-1ß in THP-1 cells stimulated by both IU1 and MDP. In conclusion, our findings suggest that USP14 could inhibit MDP-induced activation of MAPK signaling and the inflammation response involved in IBD, and that USP14 is a potential therapeutic target for IBD.

Activating UCHL1 through the CRISPR activation system promotes cartilage differentiation mediated by HIF-1α/SOX9.

Developing strategies to enhance cartilage differentiation in mesenchymal stem cells and preserve the extracellular matrix is crucial for successful cartilage tissue reconstruction. Hypoxia-inducible factor-1α (HIF-1α) plays a pivotal role in maintaining the extracellular matrix and chondrocyte phenotype, thus serving as a key regulator in chondral tissue engineering strategies. Recent studies have shown that Ubiquitin C-terminal hydrolase L1 (UCHL1) is involved in the deubiquitylation of HIF-1α. However, the regulatory role of UCHL1 in chondrogenic differentiation has not been investigated. In the present study, we initially validated the promotive effect of UCHL1 expression on chondrogenesis in adipose-derived stem cells (ADSCs). Subsequently, a hybrid baculovirus system was designed and employed to utilize three CRISPR activation (CRISPRa) systems, employing dead Cas9 (dCas9) from three distinct bacterial sources to target UCHL1. Then UCHL1 and HIF-1α inhibitor and siRNA targeting SRY-box transcription factor 9 (SOX9) were used to block UCHL1, HIF-1α and SOX9, respectively. Cartilage differentiation and chondrogenesis were measured by qRT-PCR, immunofluorescence and histological staining. We observed that the CRISPRa system derived from Staphylococcus aureus exhibited superior efficiency in activating UCHL1 compared to the commonly used the CRISPRa system derived from Streptococcus pyogenes. Furthermore, the duration of activation was extended by utilizing the Cre/loxP-based hybrid baculovirus. Moreover, our findings show that UCHL1 enhances SOX9 expression by regulating the stability and localization of HIF-1α, which promotes cartilage production in ADSCs. These findings suggest that activating UCHL1 using the CRISPRa system holds significant potential for applications in cartilage regeneration.

Comprehensive Analysis of Juvenile Nasopharyngeal Angiofibromas via Whole-Exome Sequencing.

INTRODUCTION: The molecular basis and mechanisms of juvenile nasopharyngeal angiofibromas (JNA) pathogenesis are still unknown. Despite being a rare and benign neoplasm, JNA is a locally aggressive and potentially destructive head and neck neoplasm, typically found in young males. The advancement of genome technologies and analytical tools has provided an unparalleled opportunity to explore the intricacy of JNA. The present study provides the first evidence of the involvement of Y-chromosome genes in JNA. METHODS: A total of 13 JNA patients at an advanced disease stage and five age-matched male controls were registered for this study. Whole-exome sequencing (WES) analysis was conducted followed by functional analysis to understand the molecular mechanism of the JNA. RESULTS: WES analysis revealed a high prevalence of mutations in 14 genes within the protein-coding, male-specific region of the Y-chromosome of young males (mean age: 13.8 ± 2.4) with JNA. These mutations, occurring at 28 distinct positions, were characterized as moderate to high impact and were prevalent in nine JNA patients but not in the control group. The most frequently mutated genes were USP9Y and UTY, followed by KDM5D, DDX3Y, and TSPY4. The expression of USP9Y, UTY, and DDX3Y was found to be co-modulated, implying their coordinated regulation as a complex. Furthermore, somatic mutations were detected in genes previously linked to JNA. CONCLUSION: The wide array of genetic mutations in the Y-chromosome male-specific region, along with the somatic alterations identified in JNA, provides novel insights into JNA pathophysiology.