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Cells Jun 2024Friedreich's ataxia (FRDA) is a progressive neurodegenerative disease caused in almost all patients by expanded guanine-adenine-adenine (GAA) trinucleotide repeats... (Review)
Review
Friedreich's ataxia (FRDA) is a progressive neurodegenerative disease caused in almost all patients by expanded guanine-adenine-adenine (GAA) trinucleotide repeats within intron 1 of the gene. This results in a relative deficiency of frataxin, a small nucleus-encoded mitochondrial protein crucial for iron-sulfur cluster biogenesis. Currently, there is only one medication, omaveloxolone, available for FRDA patients, and it is limited to patients 16 years of age and older. This necessitates the development of new medications. Frataxin restoration is one of the main strategies in potential treatment options as it addresses the root cause of the disease. Comprehending the control of frataxin at the transcriptional, post-transcriptional, and post-translational stages could offer potential therapeutic approaches for addressing the illness. This review aims to provide a general overview of the regulation of frataxin and its implications for a possible therapeutic treatment of FRDA.
Topics: Humans; Frataxin; Iron-Binding Proteins; Friedreich Ataxia; Animals; Gene Expression Regulation
PubMed: 38920668
DOI: 10.3390/cells13121040 -
Frontiers in Pharmacology 2024Alzheimer's disease (AD) is one of the most common chronic neurodegenerative diseases. Hyperphosphorylated tau plays an indispensable role in neuronal dysfunction and...
Alzheimer's disease (AD) is one of the most common chronic neurodegenerative diseases. Hyperphosphorylated tau plays an indispensable role in neuronal dysfunction and synaptic damage in AD. Proteolysis-targeting chimeras (PROTACs) are a novel type of chimeric molecule that can degrade target proteins by inducing their polyubiquitination. This approach has shown promise for reducing tau protein levels, which is a potential therapeutic target for AD. Compared with traditional drug therapies, the use of PROTACs to reduce tau levels may offer a more specific and efficient strategy for treating AD, with fewer side effects. In the present study, we designed and synthesized a series of small-molecule PROTACs to knock down tau protein. Of these, compound was able to lower both total and phosphorylated tau levels in HEK293 cells with stable expression of wild-type full-length human tau (termed HEK293-htau) and htau-overexpressed mice. Western blot findings indicated that degraded tau protein through the ubiquitin-proteasome system in a time-dependent manner. In htau-overexpressed mice, the results of both the novel object recognition and Morris water maze tests revealed that markedly improved cognitive function. Together, our findings suggest that the use of the small-molecule PROTAC to degrade phosphorylated tau may be a promising therapeutic strategy for AD.
PubMed: 38919259
DOI: 10.3389/fphar.2024.1351792 -
Asian Pacific Journal of Cancer... Jun 2024As one of the main molecules in BCR-ABL signaling, c-Myc acts as a pivotal key in disease progression and disruption of long-term remission in patients with CML.
BACKGROUND
As one of the main molecules in BCR-ABL signaling, c-Myc acts as a pivotal key in disease progression and disruption of long-term remission in patients with CML.
OBJECTIVES
To clarify the effects of c-Myc inhibition in CML, we examined the anti-tumor property of a well-known small molecule inhibitor of c-Myc 10058-F4 on K562 cell line.
METHODS
This experimental study was conducted in K562 cell line for evaluation of cytotoxic activity of 10058-F4 using Trypan blue and MTT assays. Flow cytometry and Quantitative RT-PCR analysis were also conducted to determine its mechanism of action. Additionally, Annexin/PI staining was performed for apoptosis assessment.
RESULTS
The results of Trypan blue and MTT assay demonstrated that inhibition of c-Myc, as shown by suppression of c-Myc expression and its associated genes PP2A, CIP2A, and hTERT, could decrease viability and metabolic activity of K562 cells, respectively. Moreover, a robust elevation in cell population in G1-phase coupled with up-regulation of p21 and p27 expression shows that 10058-F4 could hamper cell proliferation, at least partly, through induction of G1 arrest. Accordingly, we found that 10058-F4 induced apoptosis via increasing Bax and Bad; In contrast, no significant alterations were observed NF-KB pathway-targeted anti-apoptotic genes in the mRNA levels. Notably, disruption of the NF-κB pathway with bortezomib as a common proteasome inhibitor sensitized K562 cells to the cytotoxic effect of 10058-F4, substantiating the fact that the NF-κB axis functions probably attenuate the K562 cells sensitivity to c-Myc inhibition.
CONCLUSIONS
It can be concluded from the results of this study that inhibition of c-Myc induces anti-neoplastic effects on CML-derived K562 cells as well as increases the efficacy of imatinib. For further insight into the safety and effectiveness of 10058-F4 in CML, in vivo studies will be required.
Topics: Humans; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Proto-Oncogene Proteins c-myc; Apoptosis; Cell Proliferation; K562 Cells; NF-kappa B; Antineoplastic Agents; Bortezomib; Tumor Cells, Cultured; Boronic Acids; RNA, Messenger; Pyrazines; Signal Transduction; Telomerase
PubMed: 38918657
DOI: 10.31557/APJCP.2024.25.6.1959 -
Scientific Reports Jun 2024Sphaeropsidins are iso-pimarane diterpenes produced by phytopathogenic fungi that display promising anticancer activities. Sphaeropsidin A, in particular, has been shown...
Sphaeropsidins are iso-pimarane diterpenes produced by phytopathogenic fungi that display promising anticancer activities. Sphaeropsidin A, in particular, has been shown to counteract regulatory volume increase, a process used by cancer cells to avoid apoptosis. This study reports the hemi-synthesis of new lipophilic derivatives obtained by modifications of the C15,C16-alkene moiety. Several of these compounds triggered severe ER swelling associated with strong proteasomal inhibition and consequently cell death, a feature that was not observed with respect to mode of action of the natural product. Significantly, an analysis from the National Cancer Institute sixty cell line testing did not reveal any correlations between the most potent derivative and any other compound in the database, except at high concentrations (LC). This study led to the discovery of a new set of sphaeropsidin derivatives that may be exploited as potential anti-cancer agents, notably due to their maintained activity towards multidrug resistant models.
Topics: Humans; Endoplasmic Reticulum; Cell Line, Tumor; Apoptosis; Antineoplastic Agents; Diterpenes; Abietanes
PubMed: 38918539
DOI: 10.1038/s41598-024-65335-3 -
BioRxiv : the Preprint Server For... Jun 2024The ubiquitin-like modifier FAT10 targets hundreds of proteins in the mammalian immune system to the 26S proteasome for degradation. This degradation pathway requires...
The ubiquitin-like modifier FAT10 targets hundreds of proteins in the mammalian immune system to the 26S proteasome for degradation. This degradation pathway requires the cofactor Nub1, yet the underlying mechanisms remain unknown. Here, we reconstituted a minimal system and revealed that Nub1 utilizes FAT10's intrinsic instability to trap its N-terminal ubiquitin-like domain in an unfolded state and deliver it to the 26S proteasome for engagement, allowing the degradation of FAT10-ylated substrates in a ubiquitin- and p97-independent manner. Through hydrogen-deuterium exchange, structural modeling, and site-directed mutagenesis, we identified the formation of a peculiar complex with FAT10 that activates Nub1 for docking to the 26S proteasome, and our cryo-EM studies visualized the highly dynamic Nub1 complex bound to the proteasomal Rpn1 subunit during FAT10 delivery and the early stages of ATP-dependent degradation. These studies thus identified a novel mode of cofactor-mediated, ubiquitin-independent substrate delivery to the 26S proteasome that relies on trapping partially unfolded states for engagement by the proteasomal ATPase motor.
PubMed: 38915702
DOI: 10.1101/2024.06.12.598715 -
Clinical and Molecular Hepatology Jun 2024Ubiquitination is widely involved in the progression of hepatocellular carcinoma (HCC) by regulating various cellular processes. However, systematic strategies for...
BACKGROUND/AIMS
Ubiquitination is widely involved in the progression of hepatocellular carcinoma (HCC) by regulating various cellular processes. However, systematic strategies for screening core ubiquitin-related genes, clarifying their functions and mechanisms, and ultimately developing potential therapeutics for patients with HCC are still lacking.
METHODS
Cox and LASSO regression analyses were performed to construct a ubiquitin-related gene prediction model for HCC. Loss- and gain-of-function studies, transcriptomic and metabolomics analysis were used to explore the function and mechanism of UBE2S on HCC cell glycolysis and growth.
RESULTS
Based on 1423 ubiquitin-related genes, a four-gene signature was successfully constructed to evaluate the prognosis of patients with HCC. UBE2S was identified in this signature with the potential to predict the survival of patients with HCC. E2F2 transcriptionally upregulated UBE2S expression by directly binding to its promoter. UBE2S positively regulated glycolysis in a HIF-1α-dependent manner, thus promoting the proliferation of HCC cells. Mechanistically, UBE2S enhanced K11-linkage polyubiquitination at lysine residues 171 and 196 of VHL independent of E3 ligase, thereby indirectly stabilizing HIF-1α protein levels by mediating the degradation of VHL by the proteasome. In particular, the combination of cephalomannine, a small molecule compound that inhibits the expression of UBE2S, and PX-478, an inhibitor of HIF-1α, significantly improved the anti-tumor efficacy.
CONCLUSIONS
UBE2S is identified as a key biomarker in HCC among the thousands of ubiquitin-related genes and promotes glycolysis by E3 enzyme-independent ubiquitination, thus serving as a therapeutic target for the treatment of HCC.
PubMed: 38915206
DOI: 10.3350/cmh.2024.0236 -
BMC Musculoskeletal Disorders Jun 2024Ankylosing spondylitis (AS) with radiographic damage is more prevalent in men than in women. IL-17, which is mainly secreted from peripheral blood mononuclear cells...
BACKGROUND
Ankylosing spondylitis (AS) with radiographic damage is more prevalent in men than in women. IL-17, which is mainly secreted from peripheral blood mononuclear cells (PBMCs), plays an important role in the development of AS. Its expression is different between male and female. However, it is still unclear whether sex dimorphism of IL-17 contribute to sex differences in AS.
METHODS
GSE221786, GSE73754, GSE25101, GSE181364 and GSE205812 datasets were collected from the Gene Expression Omnibus (GEO) database. Differential expressed genes (DEGs) were analyzed with the Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) methods. CIBERSORTx and EcoTyper algorithms were used for immune infiltration analyses. Machine learning based on the XGBoost algorithm model was used to identify the impact of DEGs. The Connectivity Map (CMAP) database was used as a drug discovery tool for exploring potential drugs based on the DEGs.
RESULTS
According to immune infiltration analyses, T cells accounted for the largest proportion of IL-17-secreting PBMCs, and KEGG analyses suggested an enhanced activation of mast cells among male AS patients, whereas the expression of TNF was higher in female AS patients. Other signaling pathways, including those involving metastasis-associated 1 family member 3 (MAT3) or proteasome, were found to be more activated in male AS patients. Regarding metabolic patterns, oxidative phosphorylation pathways and lipid oxidation were significantly upregulated in male AS patients. In XGBoost algorithm model, DEGs including METRN and TMC4 played important roles in the disease process. we integrated the CMAP database for systematic analyses of polypharmacology and drug repurposing, which indicated that atorvastatin, famciclocir, ATN-161 and taselisib may be applicable to the treatment of AS.
CONCLUSIONS
We analyzed the sex dimorphism of IL-17-secreting PBMCs in AS. The results showed that mast cell activation was stronger in males, while the expression of TNF was higher in females. In addition, through machine learning and the CMAP database, we found that genes such as METRN and TMC4 may promote the development of AS, and drugs such as atorvastatin potentially could be used for AS treatment.
Topics: Humans; Female; Male; Interleukin-17; Spondylitis, Ankylosing; Machine Learning; Leukocytes, Mononuclear; Sex Characteristics; Computational Biology; Databases, Genetic; Gene Expression Profiling
PubMed: 38914997
DOI: 10.1186/s12891-024-07589-6 -
Cell Death & Disease Jun 2024Protein homeostasis is predominantly governed through post-translational modification (PTM). UBE3B, identified as an oncoprotein, exhibits elevated protein levels in...
Protein homeostasis is predominantly governed through post-translational modification (PTM). UBE3B, identified as an oncoprotein, exhibits elevated protein levels in breast cancer. However, the impact of PTM on UBE3B remains unexplored. In this study, we show that VHL is a bona fide E3 ligase for UBE3B. Mechanistically, VHL directly binds to UBE3B, facilitating its lysine 48 (K48)-linked polyubiquitination at K286 and K427 in a prolyl hydroxylase (PHD)-independent manner. Consequently, this promotes the proteasomal degradation of UBE3B. The K286/427R mutation of UBE3B dramatically abolishes the inhibitory effect of VHL on breast tumor growth and lung metastasis. Additionally, the protein levels of UBE3B and VHL exhibit a negative correlation in breast cancer tissues. These findings delineate an important layer of UBE3B regulation by VHL.
Topics: Humans; Breast Neoplasms; Female; Von Hippel-Lindau Tumor Suppressor Protein; Ubiquitin-Protein Ligases; Ubiquitination; Animals; Cell Line, Tumor; Cell Proliferation; Lung Neoplasms; Neoplasm Metastasis; Mice, Nude; Mice; HEK293 Cells; Protein Binding
PubMed: 38914543
DOI: 10.1038/s41419-024-06844-x -
Frontiers in Immunology 2024Infections are common in plasma cell cancer multiple myeloma (MM) due to disease-related immune deficiencies and cancer treatment. Myeloma cells express Toll-like...
Toll-like receptor signaling in multiple myeloma cells promotes the expression of pro-survival genes B-cell lymphoma 2 and MYC and modulates the expression of B-cell maturation antigen.
Infections are common in plasma cell cancer multiple myeloma (MM) due to disease-related immune deficiencies and cancer treatment. Myeloma cells express Toll-like receptors (TLRs), and TLR activation has been shown to induce proliferative and pro-survival signals in cancer cells. MM is a complex and heterogeneous disease, and expression levels of TLRs as well as downstream signaling components are likely to differ between patients. Here, we show that in a large cohort of patients, TLR1, TLR4, TLR6, TLR9, and TLR10 are the most highly expressed in primary CD138 cells. Using an MM cell line expressing TLR4 and TLR9 as a model, we demonstrate that TLR4 and TLR9 activation promoted the expression of well-established pro-survival and oncogenes in MM such as , , , and . TLR4 and TLR9 activation inhibited the efficacy of proteasome inhibitors bortezomib and carfilzomib, drugs used in the treatment of MM. Inhibiting the autophagosome-lysosome protein degradation pathway by hydroxychloroquine (HCQ) diminished the protective effect of TLR activation on proteasome inhibitor-induced cytotoxicity. We also found that TLR signaling downregulated the expression of , the gene encoding for B-cell maturation antigen (BCMA). , , and were upregulated in approximately 50% of primary cells, while the response to TLR signaling in terms of expression was dichotomous, as an equal fraction of patients showed upregulation and downregulation of the gene. While proteasome inhibitors are part of first-line MM treatment, several of the new anti-MM immune therapeutic drugs target BCMA. Thus, TLR activation may render MM cells less responsive to commonly used anti-myeloma drugs.
Topics: Humans; Multiple Myeloma; Signal Transduction; B-Cell Maturation Antigen; Cell Line, Tumor; Toll-Like Receptors; Proto-Oncogene Proteins c-myc; Gene Expression Regulation, Neoplastic; Proto-Oncogene Proteins c-bcl-2; Bortezomib; Male
PubMed: 38911853
DOI: 10.3389/fimmu.2024.1393906 -
Cell Death Discovery Jun 2024LIMA1 is a LIM domain and Actin binding 1 protein that acts as a skeleton protein to promote cholesterol absorption, which makes it an ideal target for interfering with...
LIMA1 is a LIM domain and Actin binding 1 protein that acts as a skeleton protein to promote cholesterol absorption, which makes it an ideal target for interfering with lipid metabolism. However, the detailed regulation of LIMA1 remains unclear. Here, we identified that ring finger protein 40 (RNF40), an E3 ubiquitin ligase previously known as an epigenetic modifier to increase H2B ubiquitination, mediated the ubiquitination of LIMA1 and thereby promoted its degradation in a proteasome-dependent manner. Fraction studies revealed that the 1-166aa fragment of LIMA1 was indispensable for the interaction with RNF40, and at least two domains of RNF40 might mediate the association of RNF40 with LIMA1. Notably, treatment with simvastatin dramatically decreased the levels of CHO and TG in control cells rather than cells with overexpressed LIMA1. Moreover, RNF40 significantly decreased lipid content, which could be reversed by LIMA1 overexpression. These findings suggest that E3 ubiquitin ligase RNF40 could directly target LIMA1 and promote its protein degradation in cytoplasm, leading to the suppression of lipid accumulation mediated by LIMA1. Collectively, this study unveils that RNF40 is a novel E3 ubiquitin ligase of LIMA1, which underpins its high therapeutic value to combat dysregulation of lipid metabolism.
PubMed: 38909032
DOI: 10.1038/s41420-024-02072-6