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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 -
Cell Death Discovery Jun 2024Ubiquitin-proteasome system (UPS) is involved in vascular smooth muscle cell (VSMC) proliferation. Deubiquitinating enzymes (DUBs) have an essential role in the...
Ubiquitin-proteasome system (UPS) is involved in vascular smooth muscle cell (VSMC) proliferation. Deubiquitinating enzymes (DUBs) have an essential role in the UPS-regulated stability of the substrate; however, the function of DUBs in intimal hyperplasia remains unclear. We screened DUBs to identify a protein responsible for regulating VSMC proliferation and identified USP14 protein that mediates cancer development, inflammation, and foam cell formation. USP14 promotes human aortic smooth muscle cell and A7r5 cell growth in vitro, and its inhibition or deficiency decreases the intimal area in the mice carotid artery ligation model. In addition, USP14 stabilizes Skp2 expression by decreasing its degradation, while Skp2 overexpression rescues USP14 loss-induced issues. The current findings suggested an essential role of USP14 in the pathology of vascular remodeling, deeming it a promising target for arterial restenosis therapy.
PubMed: 38909015
DOI: 10.1038/s41420-024-02069-1 -
The Journal of Biological Chemistry Jun 2024Macrophages are essential regulators of inflammation and bone loss. RANKL, a pro-inflammatory cytokine, is responsible for macrophage differentiation to osteoclasts and...
Macrophages are essential regulators of inflammation and bone loss. RANKL, a pro-inflammatory cytokine, is responsible for macrophage differentiation to osteoclasts and bone loss. We recently showed that 14-3-3ζ-knockout (Ywhaz) rats exhibit increased bone loss in the inflammatory arthritis model. 14-3-3ζ is a cytosolic adaptor protein that actively participates in many signaling transductions. However, the role of 14-3-3ζ in RANKL signaling or bone remodeling is unknown. We investigated how 14-3-3ζ affects osteoclast activity by evaluating its role in RANKL signaling. We utilized 14-3-3ζ-deficient primary bone marrow-derived macrophages (BMDMs) obtained from wildtype (Wt) and Ywhaz animals, and RAW cells generated using CRISPR-Cas9. Our results showed that 14-3-3ζ-deficient macrophages, upon RANKL stimulation, have bigger and stronger TRAP-positive multinucleated cells and increased bone resorption activity. The presence of 14-3-3ζ suppressed RANKL-induced MAPK and AKT phosphorylation, transcription factors (NFATC1 and p65) nuclear translocation, and subsequently, gene induction (Rank, Acp5, and Ctsk). Mechanistically, 14-3-3ζ interacts with TRAF6, an essential component of the RANKL receptor complex. Upon RANKL stimulation, 14-3-3ζ-TRAF6 interaction was increased, while RANK-TRAF6 interaction was decreased. Importantly, 14-3-3ζ supported TRAF6 ubiquitination and degradation by the proteasomal pathway, thus dampening the downstream RANKL signaling. Together, we show that 14-3-3ζ regulates TRAF6 levels to suppress inflammatory RANKL signaling and osteoclast activity. To the best of our knowledge, this is the first report on 14-3-3ζ regulation of RANKL signaling and osteoclast activation.
PubMed: 38908751
DOI: 10.1016/j.jbc.2024.107487 -
Biomedicine & Pharmacotherapy =... Jun 2024This study examines the involvement of TRIM59 in silica-induced pulmonary fibrosis and explores the therapeutic efficacy of Tanshinone IIA (Tan IIA). In vivo experiments...
This study examines the involvement of TRIM59 in silica-induced pulmonary fibrosis and explores the therapeutic efficacy of Tanshinone IIA (Tan IIA). In vivo experiments conducted on rats with silica-induced pulmonary fibrosis unveiled an increase in TRIM59 levels and a decrease in PPM1A levels. Subsequent investigations using in vitro silicosis cell models demonstrated that modulation of TRIM59 expression significantly impacts silicosis fibrosis, influencing the levels of PPM1A and activation of the Smad2/3 signaling pathway. Immunofluorescence and co-immunoprecipitation assays confirmed the interaction between TRIM59 and PPM1A in fibroblasts, wherein TRIM59 facilitated the degradation of PPM1A protein via proteasomal and ubiquitin-mediated pathways. Furthermore, employing a rat model of silica-induced pulmonary fibrosis, Tan IIA exhibited efficacy in mitigating lung tissue damage and fibrosis. Immunohistochemical analysis validated the upregulation of TRIM59 and downregulation of PPM1A in silica-induced pulmonary fibrosis, which Tan IIA alleviated. In vitro studies elucidated the mechanism by which Tan IIA regulates the Smad2/3 signaling pathway through TRIM59-mediated modulation of PPM1A. Treatment with Tan IIA in silica-induced fibrosis cell models resulted in concentration-dependent reductions in fibrotic markers and attenuation of relevant protein expressions. Tan IIA intervention in silica-induced fibrosis cell models mitigated the TRIM59-induced upregulation of fibrotic markers and enhanced PPM1A expression, thereby partially reversing Smad2/3 activation. Overall, the findings indicate that while overexpression of TRIM59 may activate the Smads pathway by suppressing PPM1A expression, treatment with Tan IIA holds promise in counteracting these effects by inhibiting TRIM59 expression.
PubMed: 38908195
DOI: 10.1016/j.biopha.2024.117014 -
Nature Communications Jun 2024Chemoresistance is a main reason for treatment failure in patients with nasopharyngeal carcinoma, but the exact regulatory mechanism underlying chemoresistance in...
Chemoresistance is a main reason for treatment failure in patients with nasopharyngeal carcinoma, but the exact regulatory mechanism underlying chemoresistance in nasopharyngeal carcinoma remains to be elucidated. Here, we identify PJA1 as a key E3 ubiquitin ligase involved in nasopharyngeal carcinoma chemoresistance that is highly expressed in nasopharyngeal carcinoma patients with nonresponse to docetaxel-cisplatin-5-fluorouracil induction chemotherapy. We find that PJA1 facilitates docetaxel resistance by inhibiting GSDME-mediated pyroptosis in nasopharyngeal carcinoma cells. Mechanistically, PJA1 promotes the degradation of the mitochondrial protein PGAM5 by increasing its K48-linked ubiquitination at K88, which further facilitates DRP1 phosphorylation at S637 and reduced mitochondrial reactive oxygen species production, resulting in suppression of GSDME-mediated pyroptosis and the antitumour immune response. PGAM5 knockdown fully restores the docetaxel sensitization effect of PJA1 knockdown. Moreover, pharmacological targeting of PJA1 with the small molecule inhibitor RTA402 enhances the docetaxel sensitivity of nasopharyngeal carcinoma in vitro and in vivo. Clinically, high PJA1 expression indicates inferior survival and poor clinical efficacy of TPF IC in nasopharyngeal carcinoma patients. Our study emphasizes the essential role of E3 ligases in regulating chemoresistance and provides therapeutic strategies for nasopharyngeal carcinoma based on targeting the ubiquitin-proteasome system.
Topics: Humans; Docetaxel; Drug Resistance, Neoplasm; Nasopharyngeal Carcinoma; Cell Line, Tumor; Nasopharyngeal Neoplasms; Pyroptosis; Ubiquitination; Animals; Ubiquitin-Protein Ligases; Mice; Mice, Nude; Female; Dynamins; Reactive Oxygen Species; Phosphoprotein Phosphatases; Male; Xenograft Model Antitumor Assays; Mice, Inbred BALB C; Antineoplastic Agents; Phosphorylation; Mitochondrial Proteins; Fluorouracil; Gene Expression Regulation, Neoplastic; Mitochondria; Cisplatin; Middle Aged; Gasdermins
PubMed: 38906860
DOI: 10.1038/s41467-024-49675-2 -
Biomedicine & Pharmacotherapy =... Jun 2024Breast cancer is one of the most prevalent malignancies affecting women worldwide, underscoring the urgent need for more effective and specific treatments....
Breast cancer is one of the most prevalent malignancies affecting women worldwide, underscoring the urgent need for more effective and specific treatments. Proteolysis-targeting chimeras (PROTACs) have emerged as a promising strategy to develop new lead compounds by selectively targeting oncoproteins for degradation. In this study, we designed, synthesized and evaluated a CRBN-based PROTAC, L055, which targets CDK9. Our findings demonstrate that L055 effectively inhibits the proliferation, induces cell cycle arrest, and decreases the survival of ERα-positive breast cancer cells in vitro. L055 specifically binds to CDK9, facilitating its degradation via the CRBN-dependent proteasomal pathway. Additionally, L055 suppressed the growth of organoids and tumors derived from T47D and MCF7 cells in nude mice. Thus, L055 represents a potential novel therapeutic agent for ERα-positive breast cancer and potentially other malignancies.
PubMed: 38906024
DOI: 10.1016/j.biopha.2024.116972 -
International Journal of Biological... 2024Shear stress-induced Dickkopf-1 (DKK1) secretion by endothelial cells (ECs) promotes EC dysfunction and accelerates atherosclerosis (AS). However, the paracrine role of...
Shear stress-induced Dickkopf-1 (DKK1) secretion by endothelial cells (ECs) promotes EC dysfunction and accelerates atherosclerosis (AS). However, the paracrine role of endothelial DKK1 in modulating adjacent smooth muscle cells (SMCs) in atherosclerosis remains unclear. This study investigated the role of EC-secreted DKK1 in SMC-derived foam cell formation under shear stress, and . Parallel-plate co-culture flow system was used to explore the cellular communication between ECs and SMCs under shear stress . Endothelium-specific knockout of DKK1 (DKK1/APOE) and endothelium-specific overexpression of DKK1 (DKK1) mice were constructed to investigate the role of endothelial DKK1 in atherosclerosis and SMC-derived foam cell formation . RNA sequencing (RNA-seq) was used to identify the downstream targets of DKK1. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), western blot, coimmunoprecipitation (Co-IP) assays and chromatin immunoprecipitation (ChIP) experiments were conducted to explore the underlying regulatory mechanisms. DKK1 is transcriptionally upregulated in ECs under conditions of low shear stress, but not in co-cultured SMCs. However, DKK1 protein in co-cultured SMCs is increased via uptake of low shear stress-induced endothelial DKK1, thereby promoting lipid uptake and foam cell formation in co-cultured SMCs via the post-translational upregulation of scavenger receptor-A (SR-A) verified in parallel-plate co-culture flow system, DKK1 and DKK1 mice. RNA sequencing revealed that DKK1-induced SR-A upregulation in SMCs is dependent on Ubiquitin-specific Protease 53 (USP53), which bound to SR-A via its USP domain and cysteine at position 41, exerting deubiquitination to maintain the stability of the SR-A protein by removing the K48 ubiquitin chain and preventing proteasomal pathway degradation, thereby mediating the effect of DKK1 on lipid uptake in SMCs. Moreover, DKK1 regulates the transcription of USP53 by facilitating the binding of transcription factor CREB to the USP53 promoter. SMC-specific overexpression of USP53 via adeno-associated virus serotype 2 vectors in DKK1/APOE mice reversed the alleviation of atherosclerotic plaque burden, SR-A expression and lipid accumulation in SMCs within plaques resulting from DKK1 deficiency. Our findings demonstrate that, endothelial DKK1, induced by pathological low shear stress, acts as an intercellular mediator, promoted the foam cell formation of SMCs. These results suggest that targeted intervention with endothelial DKK1 may confer beneficial effects on atherosclerosis.
Topics: Animals; Atherosclerosis; Mice; Intercellular Signaling Peptides and Proteins; Foam Cells; Myocytes, Smooth Muscle; Endothelial Cells; Humans; Ubiquitination; Male; Coculture Techniques; Mice, Knockout; Ubiquitin-Specific Proteases; Mice, Inbred C57BL
PubMed: 38904030
DOI: 10.7150/ijbs.91957 -
International Journal of Biological... 2024Cysteine-rich angiogenic inducer 61 (CYR61), also called CCN1, has long been characterized as a secretory protein. Nevertheless, the intracellular function of CYR61...
Cysteine-rich angiogenic inducer 61 (CYR61), also called CCN1, has long been characterized as a secretory protein. Nevertheless, the intracellular function of CYR61 remains unclear. Here, we found that CYR61 is important for proper cell cycle progression. Specifically, CYR61 interacts with microtubules and promotes microtubule polymerization to ensure mitotic entry. Moreover, CYR61 interacts with PLK1 and accumulates during the mitotic process, followed by degradation as mitosis concludes. The proteolysis of CYR61 requires the PLK1 kinase activity, which directly phosphorylates two conserved motifs on CYR61, enhancing its interaction with the SCF E3 complex subunit FBW7 and mediating its degradation by the proteasome. Mutations of phosphorylation sites of Ser167 and Ser188 greatly increase CYR61's stability, while deletion of CYR61 extends prophase and metaphase and delays anaphase onset. In summary, our findings highlight the precise control of the intracellular CYR61 by the PLK1-FBW7 pathway, accentuating its significance as a microtubule-associated protein during mitotic progression.
Topics: Protein Serine-Threonine Kinases; Humans; Polo-Like Kinase 1; Mitosis; Cell Cycle Proteins; Proto-Oncogene Proteins; Cysteine-Rich Protein 61; Microtubules; F-Box-WD Repeat-Containing Protein 7; HeLa Cells; Phosphorylation; Ubiquitin-Protein Ligases; Microtubule-Associated Proteins
PubMed: 38904029
DOI: 10.7150/ijbs.93335 -
International Journal of Biological... 2024Pancreatic cancer is the deadliest malignancy with a poor response to chemotherapy but is potentially indicated for ferroptosis therapy. Here we identified that...
Pancreatic cancer is the deadliest malignancy with a poor response to chemotherapy but is potentially indicated for ferroptosis therapy. Here we identified that cytoplasmic polyadenylation element binding protein 1 (CPEB1) regulates NRF2 proteostasis and susceptibility to ferroptosis in pancreatic ductal adenocarcinoma (PDAC). We found that CPEB1 deficiency in cancer cells promotes the translation of p62/SQSTM1 by facilitating mRNA polyadenylation. Consequently, upregulated p62 enhances NRF2 stability by sequestering KEAP1, an E3 ligase for proteasomal degradation of NRF2, leading to the transcriptional activation of anti-ferroptosis genes. In support of the critical role of this signaling cascade in cancer therapy, CPEB1-deficient pancreatic cancer cells display higher resistance to ferroptosis-inducing agents than their CPEB1-normal counterparts and . Furthermore, based on the pathological evaluation of tissue specimens from 90 PDAC patients, we established that CPEB1 is an independent prognosticator whose expression level is closely associated with clinical therapeutic outcomes in PDAC. These findings identify the role of CPEB1 as a key ferroptosis regulator and a potential prognosticator in pancreatic cancer.
Topics: Humans; Ferroptosis; Pancreatic Neoplasms; NF-E2-Related Factor 2; Cell Line, Tumor; Animals; mRNA Cleavage and Polyadenylation Factors; Mice; Proteostasis; Transcription Factors; Carcinoma, Pancreatic Ductal; Kelch-Like ECH-Associated Protein 1; Mice, Nude
PubMed: 38904009
DOI: 10.7150/ijbs.95962