ABSTRACT
The human malaria parasite Plasmodium falciparum (P.â falciparum) continues to pose a significant public health challenge, leading to millions of fatalities globally. Halofuginone (HF) has shown a significant anti-P.â falciparum effect, suggesting its potential as a therapeutic agent for malaria treatment. In this study, we synthesized a photoaffinity labeling probe of HF to identify its direct target in P.â falciparum. Our results reveal that ubiquitin carboxyl-terminal hydrolase 3 (PfUCHL3) acts as a crucial target protein of HF, which modulates parasite growth in the intraerythrocytic cycle. In particular, we discovered that HF potentially forms hydrogen bonds with the Leu10, Glu11, and Arg217 sites of PfUCHL3, thereby inducing an allosteric effect by promoting the embedding of the helix 6' region on the protein surface. Furthermore, HF disrupts the expression of multiple functional proteins mediated by PfUCHL3, specifically those that play crucial roles in amino acid biosynthesis and metabolism in P.â falciparum. Taken together, this study highlights PfUCHL3 as a previously undisclosed druggable target of HF, which contributes to the development of novel anti-malarial agents in the future.
ABSTRACT
Neuroinflammation is initiated in response to a variety of endogenous and exogenous sources. As the resident macrophages of the central nervous system, the polarization of microglia into either the M1 pro-inflammatory phenotype or the M2 anti-inflammatory phenotype holds great promise as a therapeutic strategy for neuroinflammation. Natural products, comprising a vital chemical library with distinctive structures and diverse functions, have been extensively employed to modulate microglial polarization for the treatment of neuroinflammation. In this review, we present up-to-date and extensive insights into the therapeutic effects and underlying mechanisms of natural products in the context of neuroinflammation. Furthermore, the review aims to present a new perspective by focusing on the targets of natural compounds, elucidating the molecular mechanisms and guiding the transition from natural-derived lead compounds to potential anti-neuroinflammatory drugs. Additionally, we provide a comprehensive overview of the challenges and limitations associated with the utilization of natural products for neuroinflammation therapy.
ABSTRACT
Fibroblast-like synoviocytes (FLS) play an important role in rheumatoid arthritis (RA)-related swelling and bone damage. Therefore, novel targets for RA therapy in FLS are urgently discovered for improving pathologic phenomenon, especially joint damage and dyskinesia. Here, we suggested that pyruvate kinase M2 (PKM2) in FLS represented a pharmacological target for RA treatment by antimalarial drug artemisinin (ART). We demonstrated that ART selectively inhibited human RA-FLS and rat collagen-induced arthritis (CIA)-FLS proliferation and migration without observed toxic effects. In particular, the identification of targets revealed that PKM2 played a crucial role as a primary regulator of the cell cycle, leading to the heightened proliferation of RA-FLS. ART exhibited a direct interaction with PKM2, resulting in an allosteric modulation that enhances the lactylation modification of PKM2. This interaction further promoted the binding of p300, ultimately preventing the nuclear translocation of PKM2 and inducing cell cycle arrest at the S phase. In vivo, ART obviously suppressed RA-mediated synovial hyperplasia, bone damage and inflammatory response to further improve motor behavior in CIA-rats. Taken together, these findings indicate that directing interventions towards PKM2 in FLS could offer a hopeful avenue for pharmaceutical treatments of RA through the regulation of cell cycle via PKM2 lactylation.
Subject(s)
Arthritis, Rheumatoid , Cell Proliferation , Synoviocytes , Synoviocytes/drug effects , Synoviocytes/metabolism , Synoviocytes/pathology , Arthritis, Rheumatoid/pathology , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/metabolism , Animals , Cell Proliferation/drug effects , Humans , Rats , Fibroblasts/drug effects , Fibroblasts/metabolism , Fibroblasts/pathology , Pyruvate Kinase/metabolism , Thyroid Hormone-Binding Proteins , Male , Thyroid Hormones/metabolism , Arthritis, Experimental/pathology , Arthritis, Experimental/drug therapy , Arthritis, Experimental/metabolism , Cell Movement/drug effects , Molecular Targeted Therapy , Membrane Proteins/metabolism , Carrier Proteins/metabolism , Small Molecule Libraries/pharmacology , Small Molecule Libraries/chemistryABSTRACT
BACKGROUND: Cayratia albifolia C.L.Li (CAC), commonly known as "Jiao-Mei-Gu" in China, has been extensively utilized by the Dong minority for several millennia to effectively alleviate symptoms associated with autoimmune diseases. CAC extract is believed to possess significant anti-inflammatory properties within the context of Dong medicine. However, an in-depth understanding of the specific pharmaceutical effects and underlying mechanisms through which CAC extract acts against rheumatoid arthritis (RA) has yet to be established. METHODS: Twenty-four Sprague-Dawley rats were divided into four groups, with six rats in each group. To induce the collagen-induced arthritis (CIA) model, the rats underwent a process of double immunization with collagen and adjuvant. CAC extract (100 mg/kg) was orally administered to rats. The anti-RA effects were evaluated in CIA rats by arthritis score, hind paw volume and histopathology analysis. Pull-down assay was conducted to identify the potential targets of CAC extract from RAW264.7 macrophage lysates. Moreover, mechanism studies of CAC extract were performed by immunofluorescence assays, real-time PCR and Western blot. RESULTS: CAC extract was found to obviously down-regulate hind paw volume of CIA rats, with diminished inflammation response and damage. 177 targets were identified from CAC extract by MS-based pull-down assay. Bioinformatics analysis found that these targets were mainly enriched in macrophage activation and neutrophils extracellular traps (NETs). Additionally, we reported that CAC extract owned significant anti-inflammatory activity by regulating PI3K-Akt-mTOR signal pathway, and inhibited NETosis in response to PMA. CONCLUSIONS: We clarified that CAC extract significantly attenuated RA by inactivating macrophage and reducing NETosis via a multi-targets regulation.
ABSTRACT
There is an urgent requirement to acquire a comprehensive comprehension of novel therapeutic targets for prostate cancer to facilitate the development of medications with innovative mechanisms. In this study, we identified gambogic acid (GBA) as a specific pyroptosis inducer in prostatic cancer cells. By using a thermal proteome profiling (TPP) strategy, we revealed that GBA induces pyroptosis by directly targeting the canopy FGF signaling regulator (CNPY3), which was previously considered "undruggable". Moreover, through the utilization of the APEX2-based proximity labeling method, we found that GBA recruited delactatease SIRT1, resulting in the elimination of lysine lactylation (Kla) on CNPY3. Of note, SIRT1-mediated delactylation influenced the cellular localization of CNPY3 to promote lysosome rupture for triggering pyroptosis. Taken together, our study identified CNPY3 as a distinctive cellular target for pyroptosis induction and its potential application in prostate cancer therapy.
Subject(s)
Prostatic Neoplasms , Proteome , Pyroptosis , Xanthones , Male , Humans , Xanthones/pharmacology , Xanthones/chemistry , Prostatic Neoplasms/pathology , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/drug therapy , Pyroptosis/drug effects , Proteome/metabolism , Proteome/drug effects , Cell Line, Tumor , Sirtuin 1/metabolismABSTRACT
The hypothalamus plays a fundamental role in controlling lipid metabolism through neuroendocrine signals. However, there are currently no available drug targets in the hypothalamus that can effectively improve human lipid metabolism. In this study, we found that the antimalarial drug artemether (ART) significantly improved lipid metabolism by specifically inhibiting microglial activation in the hypothalamus of high-fat diet-induced mice. Mechanically, ART protects the thyrotropin-releasing hormone (TRH) neurons surrounding microglial cells from inflammatory damage and promotes the release of TRH into the peripheral circulation. As a result, TRH stimulates the synthesis of thyroid hormone (TH), leading to a significant improvement in hepatic lipid disorders. Subsequently, we employed a biotin-labeled ART chemical probe to identify the direct cellular target in microglial cells as protein kinase Cδ (PKCδ). Importantly, ART directly targeted PKCδ to inhibit its palmitoylation modification by blocking the binding of zinc finger DHHC-type palmitoyltransferase 5 (ZDHHC5), which resulted in the inhibition of downstream neuroinflammation signaling. In vivo, hypothalamic microglia-specific PKCδ knockdown markedly impaired ART-dependent neuroendocrine regulation and lipid metabolism improvement in mice. Furthermore, single-cell transcriptomics analysis in human brain tissues revealed that the level of PKCδ in microglia positively correlated with individuals who had hyperlipemia, thereby highlighting a clinical translational value. Collectively, these data suggest that the palmitoylation of microglial PKCδ in the hypothalamus plays a role in modulating peripheral lipid metabolism through hypothalamus-liver communication, and provides a promising therapeutic target for fatty liver diseases.
Subject(s)
Lipoylation , Non-alcoholic Fatty Liver Disease , Humans , Animals , Mice , Microglia , Hypothalamus , Lipid Metabolism , ArtemetherABSTRACT
Mercury sulfide (HgS) exerts extensive biological effects on neuronal function. To investigate the direct target of HgS in neuronal cells, we developed a biotin-tagged HgS probe (bio-HgS) and employed an affinity purification technique to capture its target proteins. Then, we identified S-phase kinase-associated protein 1 (Skp1) as a potential target of HgS. Unexpectedly, we discovered that HgS covalently binds to Skp1 through a "Cys62-HgS-Cys120" mode. Moreover, our findings revealed that HgS inhibits the ubiquitin-protease system through Skp1 to up-regulate SNAP-25 expression, thereby triggering synaptic vesicle exocytosis to regulate locomotion ability in C. elegans. Collectively, our findings may promote a comprehensive interpretation of the pharmacological mechanism of mercury sulfide on neuroprotective function.
Subject(s)
Mercury Compounds , Mercury , Animals , Mercury/metabolism , S-Phase Kinase-Associated Proteins , Caenorhabditis elegans/metabolism , Neuroprotection , Sulfides/metabolismABSTRACT
Aberrant PCK2 overexpression has been linked to an unfavorable prognosis and shorter survival, particularly in hepatocellular carcinoma (HCC). Thus, the inactivation of PCK2 provides a promising strategy for HCC treatment. In this study, we used a chemical genetic strategy to identify a natural-derived small-molecule cucurbitacin B (CuB) as a selective PCK2 inhibitor. CuB covalently bound to PCK2 at a unique Cys63 site, blocking the Ω-loop lid domain formation via a previously undisclosed allosteric mechanism. Additionally, targeted lipidomics analysis also revealed that CuB destroyed mitochondrial membrane integrity, leading to the disruption of mitochondrial fusion-fission dynamics. Taken together, this study highlights the discovery of a small-molecule CuB, which reprograms lipid metabolism for controlling mitochondrial dynamics via targeting PCK2 in cancer cells.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/pathology , Mitochondrial Dynamics , Liver Neoplasms/drug therapy , Liver Neoplasms/pathology , Allosteric Regulation , Phosphoenolpyruvate Carboxykinase (ATP)ABSTRACT
Isocitrate dehydrogenase (IDH) 1 and 2, as essential enzymes in energy metabolism, contribute to the survival and drug resistance of a variety of solid tumors, especially for colorectal cancer (CRC). However, the underlying molecular mechanism still remains unclear. In this study, IDH1 was identified as a crucial cellular target of a natural-derived anti-CRC small molecule lycorine, using the unbiased thermal proteome profiling (TPP) strategy. We found that lycorine directly targeted a unique C-terminal domain of IDH1, and disrupted IDH1 interaction with deacetylase sirtuin 1 (SIRT1), thereby significantly promoting IDH1 acetylation modification. Then, lycorine noticeably triggered oxidative stress in CRC cells to cause mitochondrial membranes injury, and subsequently facilitated mitochondrial fission. Specific knockdown of IDH1 or SIRT1 markedly aggrieved lycorine-mediated oxidative stress and mitochondrial fragmentation in CRC cells. Furthermore, the combination of lycorine and sirtuins blocker nicotinamide (NAM) exhibited a synergic therapeutic effect in CRC cells. Collectively, our results reveal that IDH1 may serve as a promising therapeutic target for CRC via pharmacologically driving oxidative stress-dependent mitochondrial dynamics imbalance.
Subject(s)
Colorectal Neoplasms , Mitochondrial Dynamics , Humans , Acetylation , Sirtuin 1 , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Isocitrate Dehydrogenase/geneticsABSTRACT
Osteoblasts play an important role in the regulation of bone homeostasis throughout life. Thus, the damage of osteoblasts can lead to serious skeletal diseases, highlighting the urgent need for novel pharmacological targets. This study introduces chemical genetics strategy by using small molecule forskolin (FSK) as a probe to explore the druggable targets for osteoporosis. Here, this work reveals that transglutaminase 2 (TGM2) served as a major cellular target of FSK to obviously induce osteoblast differentiation. Then, this work identifies a previously undisclosed allosteric site in the catalytic core of TGM2. In particular, FSK formed multiple hydrogen bonds in a saddle-like domain to induce an "open" conformation of the ß-sandwich domain in TGM2, thereby promoting the substrate protein crosslinks by incorporating polyamine. Furthermore, this work finds that TGM2 interacted with several mitochondrial homeostasis-associated proteins to improve mitochondrial dynamics and ATP production for osteoblast differentiation. Finally, this work observes that FSK effectively ameliorated osteoporosis in the ovariectomy mice model. Taken together, these findings show a previously undescribed pharmacological allosteric site on TGM2 for osteoporosis treatment, and also provide an available chemical tool for interrogating TGM2 biology and developing bone anabolic agent.
Subject(s)
Osteoporosis , Protein Glutamine gamma Glutamyltransferase 2 , Mice , Animals , Female , Allosteric Regulation , Osteogenesis , Osteoblasts/metabolism , Osteoporosis/drug therapy , Osteoporosis/metabolismABSTRACT
This study aimed to identify the direct pharmacological targets of Jingfang Granules in treating infectious pneumonia via "target fishing" strategy. Moreover, the molecular mechanism of Jingfang Granules in treating infectious pneumonia was also investigated based on target-related pharmacological signaling pathways. First, the Jingfang Granules extract-bound magnetic nanoparticles were prepared, which were incubated with lipopolysaccharide(LPS)-induced mouse pneumonia tissue lysates. The captured proteins were analyzed by high-resolution mass spectrometry(HRMS), and the target groups with specific binding to the Jingfang Granules extract were screened out. Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis was used to identify the target protein-associated signaling pathways. On this basis, the LPS-induced mouse model of infectious pneumonia was established. The possible biological functions of target proteins were verified by hematoxylin-eosin(HE) staining and immunohistochemical assay. A total of 186 Jingfang Granules-specific binding proteins were identified from lung tissues. KEGG pathway enrichment analysis showed that the target protein-associated signaling pathways mainly included Salmonella infection, vascular and pulmonary epithelial adherens junction, ribosomal viral replication, viral endocytosis, and fatty acid degradation. The target functions of Jingfang Granules were related to pulmonary inflammation and immunity, pulmonary energy metabolism, pulmonary microcirculation, and viral infection. Based on the in vivo inflammation model, Jingfang Granules significantly improved the alveolar structure of the LPS-induced mouse model of infectious pneumonia and down-regulated the expressions of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6). Meanwhile, Jingfang Gra-nules significantly up-regulated the expressions of key proteins of mitochondrial function COX â £ and ATP, microcirculation-related proteins CD31 and Occludin, and proteins associated with viral infection DDX21 and DDX3. These results suggest that Jingfang Gra-nules can inhibit lung inflammation, improve lung energy metabolism and pulmonary microcirculation, resist virus infection, thus playing a protective role in the lung. This study systematically explains the molecular mechanism of Jingfang Granules in the treatment of respiratory inflammation from the perspective of target-signaling pathway-pharmacological efficacy, thereby providing key information for clinical rational use of Jingfang Granules and expanding potential pharmacological application.
Subject(s)
Anti-Infective Agents , Pneumonia , Animals , Mice , Lipopolysaccharides , Inflammation , Biological Assay , Disease Models, Animal , Interleukin-6ABSTRACT
This study identified the anti-depression targets of Kaixin San(KXS) in the brain tissue with "target fishing" strategy, and explored the target-associated pharmacological signaling pathways to reveal the anti-depression molecular mechanism of KXS. The Balb/c mouse model of depression was established by chronic unpredictable mild stress(CUMS) and the anti-depression effect of KXS was evaluated by forced swimming test and sucrose preference test. KXS active components were bonded to the benzophenone-modified magnetic nanoparticles by photocrosslinking reaction for capturing target proteins from cortex, thalamus and hippocampus of depressive mice. The target proteins were identified by liquid chromatography-mass spectrometry/mass spectrometry(LC-MS/MS). The enrichment analysis on signaling pathways was performed by Cytoscape. The potential biological functions of targets were verified by immunohistochemistry and Western blot assay. The results showed that KXS significantly improved the behavioral indexes. There were 64, 91, and 44 potential targets of KXS identified in cortex, thalamus, and hippocampus, respectively, according to the target identification experiment. The functions of these targets were mainly associated with vasopressin-regulated water reabsorption, salmonella infection, thyroid hormone synthesis, and other signaling pathways. Besides, the results of immunohistochemistry and Western blot showed that KXS up-regulated the expressions of argipressine(AVP) in the cortex, heat shock protein 60(HSP60), cytochrome C oxidase 4(COX4), and thyrotropin-releasing hormone(TRH) in the thalamus, and down-regulated the expressions of tumor necrosis factor-α(TNF-α) and nuclear factor kappa B(NF-κB) p65 in the thalamus. Therefore, KXS may exert anti-depression effect through regulating vasopressin signaling pathway in the cortex and inflammation, energy metabolism, and thyroid hormone signaling pathways in the thalamus, and the effect of KXS on hippocampus is not significant.
Subject(s)
Depression , Drugs, Chinese Herbal , Animals , Mice , Chromatography, Liquid , Disease Models, Animal , Drugs, Chinese Herbal/chemistry , Hippocampus , Stress, Psychological/drug therapy , Tandem Mass Spectrometry , Depression/drug therapyABSTRACT
Ulcerative colitis (UC) is an inflammatory disease of the colon with an unmet need for therapeutic targets. Ethyl gallate (EG) is a natural small molecule for UC treatment, but its cellular target is unknown. By labelling EG with a diazirine photocrosslinker and a click chemistry handle, we identified phosphatidyl-ethanolamine binding protein1 (PEBP1) as a direct cellular target of EG by forming hydrogen bonds with Asp70 and Tyr120. In particular, hydrogen/deuterium exchange mass spectrometry indicated that EG induced the sequence (residues 141-153) embedding to inhibit S153 phosphorylation of PEBP1. Additionally, the EG-mediated sequence (residues 108-122) exposure significantly enhanced PEBP1-Raf-1 interaction to block the downstream NF-κB inflammatory pathway in macrophages. Moreover, PEBP1 siRNA substantially reversed the EG-dependent down-regulation of the phosphorylation of IKKß, IκBα and NF-κB, demonstrating that the NF-κB signal functioned as an essential anti-inflammation mechanism of PEBP1. Collectively, we revealed PEBP1 as a previously undescribed cellular target in macrophages for UC therapy and identified a new allosteric site for PEBP1 biology study using EG as a chemical probe.
Subject(s)
Colitis, Ulcerative , NF-kappa B , Humans , NF-kappa B/metabolism , NF-kappa B/therapeutic use , Macrophage Activation , I-kappa B Kinase/metabolism , Phosphatidylethanolamine Binding Protein/chemistry , Phosphatidylethanolamine Binding Protein/metabolismABSTRACT
Understanding the direct interaction of nanostructures per se with biological systems is important for biomedical applications. However, whether nanostructures regulate biological systems by targeting specific cellular proteins remains largely unknown. In the present work, self-assembling nanomicelles are constructed using small-molecule oleanolic acid (OA) as a molecular template. Unexpectedly, without modifications by functional ligands, OA nanomicelles significantly activate cellular proteasome function by directly binding to 20S proteasome subunit alpha 6 (PSMA6). Mechanism study reveals that OA nanomicelles interact with PSMA6 to dynamically modulate its N-terminal domain conformation change, thereby controlling the entry of proteins into 20S proteasome. Subsequently, OA nanomicelles accelerate the degradation of several crucial proteins, thus potently driving cancer cell pyroptosis. For translational medicine, OA nanomicelles exhibit a significant anticancer potential in tumor-bearing mouse models and stimulate immune cell infiltration. Collectively, this proof-of-concept study advances the mechanical understanding of nanostructure-guided biological effects via their inherent capacity to activate proteasome.
Subject(s)
Nanostructures , Neoplasms , Animals , Mice , Proteasome Endopeptidase Complex/metabolism , Pyroptosis , Cytoplasm/metabolism , Micelles , Nanostructures/chemistryABSTRACT
Gastric, liver, and colorectal cancers belong to gastrointestinal (GI) cancers, one of the most threatening diseases in the world. The tonics class in Chinese medicines plays a critical role in antigastrointestinal cancer as adjuvants. However, it is a challenge to study the effects and underlying mechanisms of tonics due to their multiple components and multiple targets; OMICs were introduced to facilitate the investigation of the complex mixture of tonics. In this review, the online databases PubMed, ProQuest, Web of Knowledge, China National Knowledge Infrastructure (CNKI), Chongqing VIP, and Wanfang were retrieved from 1 January 2011 to 31 May 2022, in an aim to summarize and discuss the research progress of the effects and, especially, the underlying mechanisms of tonics for antigastrointestinal cancers via OMICs. The results showed that through the combination of OMICs and other technologies, tonics have been used for gastrointestinal cancer by targeting cancer hallmarks, enhancing body resistance to carcinogenesis, enhancing therapeutic effects, and/or decreasing side effects. In conclusion, tonics may play a promising role in gastric, liver, and colorectal cancers as adjuvants and can be well investigated via the combination of OMICs and other technologies, which deserves further study.
ABSTRACT
BACKGROUND: The E2F family of transcription factors play a crucial role in the development of various cancers. However, E2F members lack targetable binding pockets and are typically considered "undruggable". Unlike canonical small-molecule therapeutics, molecular glues mediate new E3 ligase-protein interactions to induce selective proteasomal degradation, which represents an attractive option to overcome these limitations. METHODS: Human proteome microarray was utilized to identify a natural product-derived molecular glue for targeting E2F2 degradation. Co-IP analysis with stable isotope labeling of amino acids in cell culture (SILAC)-based quantitative proteomics was carried out to further explore the E3 ligase for E2F2 degradation. FINDINGS: In this study, we identified a molecular glue bufalin, which significantly promoted E2F2 degradation. Unexpectedly, E2F2 underwent ubiquitination and proteasomal degradation via a previously undisclosed atypical E3 ligase, zinc finger protein 91 (ZFP91). In particular, we observed that bufalin markedly promoted E2F2-ZFP91 complex formation, thereby leading to E2F2 polyubiquitination via K48-linked ubiquitin chains for degradation. E2F2 degradation subsequently caused transcriptional suppression of multiple oncogenes including c-Myc, CCNE1, CCNE2, MCM5 and CDK1, and inhibited hepatocellular carcinoma growth in vitro and in vivo. INTERPRETATION: Collectively, our findings open up a new direction for transcription factors degradation by targeting atypical E3 ligase ZFP91. Meanwhile, the chemical knockdown strategy with molecular glue may promote innovative transcription factor degrader development in cancer therapy. FUNDING: This work was financially supported by the National Key Research and Development Project of China (2022YFC3501601), National Natural Sciences Foundation of China (81973505, 82174008, 82030114), and China Postdoctoral Science Foundation (2019M650396), the Fundamental Research Funds for the Central Universities.
Subject(s)
Neoplasms , Ubiquitin-Protein Ligases , Humans , E2F2 Transcription Factor/drug effects , E2F2 Transcription Factor/metabolism , Proteolysis , Transcription Factors/genetics , Transcription Factors/metabolism , Ubiquitin-Protein Ligases/metabolism , UbiquitinationABSTRACT
Neuroinflammation is a leading cause for neurological disorders. Carbazole alkaloids, isolated from the medicinal plants of Murraya species (Rutaceae), have exhibited wide pharmacological activities particularly for neuroinflammation. However, its underlying cellular targets and molecular mechanisms still remain unclear. In current study, we found that murrayafoline A (MA), a carbazole alkaloid obtained from Murraya tetramera, potently inhibited the production of neuroinflammation mediators, such as nitric oxide (NO), TNF-α, IL-6 and IL-1ß in LPS-induced BV-2 microglial cells. Then, we performed thermal proteome profiling (TPP) strategy to identify Specificity protein 1 (Sp1) as a potential cellular target of MA. Moreover, we performed surface plasmon resonance (SPR), cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DRATS) assays to confirm the direct interaction between MA and Sp1. Furthermore, we downregulated Sp1 expression in BV2 cells using siRNA transfection, and observed that Sp1 knockdown significantly antagonized MA-mediated inhibition of neuroinflammation mediator production. Meanwhile, Sp1 knockdown also markedly reversed MA-mediated inactivation of IKKß/NF-κB and p38/JNK MAPKs pathways. Finally, in vivo studies revealed that MA significantly suppressed the expression of Iba-1, TNF-α, and IL-6, while increased the number of Nissl bodies in the brains of LPS-induced mice. Taken together, our study demonstrated that MA exerted obvious anti-neuroinflammation effect by directly targeting Sp1, thereby inhibiting NF-κB and MAPK signaling pathways. Our findings also provided a promising direction of pharmacological targeting Sp1 for anti-neuroinflammation therapeutics as well as novel agent development.
Subject(s)
Alkaloids , Anti-Inflammatory Agents , Carbazoles , Murraya , Neuroinflammatory Diseases , Sp1 Transcription Factor , Animals , Mice , Alkaloids/pharmacology , Alkaloids/therapeutic use , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Carbazoles/metabolism , Carbazoles/therapeutic use , Interleukin-6/metabolism , Lipopolysaccharides , Microglia/drug effects , Murraya/chemistry , NF-kappa B/metabolism , Tumor Necrosis Factor-alpha/metabolism , Sp1 Transcription Factor/metabolism , Neuroinflammatory Diseases/drug therapyABSTRACT
Neuroinflammation is a fundamental contributor to progressive neuronal damage, which arouses a heightened interest in neurodegenerative disease therapy. Ubiquitin-specific protease 7 (USP7) has a crucial role in regulating protein stability in multiple biological processes; however, the potential role of USP7 in neurodegenerative progression is poorly understood. Here, we discover the natural small molecule eupalinolide B (EB), which targets USP7 to inhibit microglia activation. Cocrystal structure reveals a previously undisclosed covalent allosteric site, Cys576, in a unique noncatalytic HUBL domain. By selectively modifying Cys576, EB allosterically inhibits USP7 to cause a ubiquitination-dependent degradation of Keap1. Keap1 function loss further results in an Nrf2-dependent transcription activation of anti-neuroinflammation genes in microglia. In vivo, pharmacological USP7 inhibition attenuates microglia activation and resultant neuron injury, thereby notably improving behavioral deficits in dementia and Parkinson's disease mouse models. Collectively, our findings provide an attractive future direction for neurodegenerative disease therapy by inhibiting microglia-mediated neuroinflammation by targeting USP7.
Subject(s)
Neurodegenerative Diseases , Ubiquitin Thiolesterase , Animals , Kelch-Like ECH-Associated Protein 1 , Mice , NF-E2-Related Factor 2/metabolism , Neurodegenerative Diseases/drug therapy , Small Molecule Libraries , Ubiquitin Thiolesterase/genetics , Ubiquitin-Specific Peptidase 7/metabolismABSTRACT
Tumor immune microenvironment (TIME) regulators are promising cancer immunotherapeutic targets. IGF2BP1, as a crucial N 6-methyladenosine (m6A) reader protein, recognizes m6A target transcripts, ultimately leading to cancer development. However, currently, the biological function of IGF2BP1 in regulating the TIME is not well-understood. In this study, we report that IGF2BP1 knockdown induces cancer cell apoptosis, thereby significantly not only activating immune cell infiltration including CD4+, CD8+ T cells, CD56+ NK cells, and F4/80+ macrophage but also decreasing PD-L1 expression in hepatocellular carcinoma (HCC). Then, chemical genetics identifies a small-molecule cucurbitacin B (CuB), which directly targets IGF2BP1 at a unique site (Cys253) in the KH1-2 domains. This leads to a pharmacological allosteric effect to block IGF2BP1 recognition of m6A mRNA targets such as c-MYC, which is highly associated with cell apoptosis and immune response. In vivo, CuB exhibits an obvious anti-HCC effect through inducing apoptosis and subsequently recruits immune cells to tumor microenvironment as well as blocking PD-L1 expression. Collectively, IGF2BP1 may serve as a novel pharmacological allosteric target for anticancer therapeutics via mediating TIME.
ABSTRACT
This study aims to identify the anti-pneumonia targets of Xiaoer Xiaoji Zhike Oral Liquid(XXZL) with "target fishing" strategy and investigate the related signaling pathways, thereby clarifying the anti-pneumonia mechanism of XXZL. To be specific, the magnetic nanoparticles cross-linked with XXZL extract were prepared based on the photochemical activity of benzophenone, which were then used to capture the target proteins from the lysate of tissue with lipopolysaccharide(LPS)-induced pneumonia in mice. Then, the target proteins were identified by liquid chromatography-tandem mass spectrometry(LC-MS/MS). The signaling pathways and interactions of target proteins were explored with KEGG and STRING analysis on Cytoscape, and the possible biological functions of the target proteins were verified by immunohistochemistry(IHC) and RT-PCR. The result showed that LC-MS/MS identified 62 potential anti-pneumonia targets of XXZL in the lungs. The targets were involved in Ras signaling pathway, mitophagy, leukocyte transendothelial migration, mitogen-activated protein kinase(MAPK) signaling pathway, platelet activation, and actomyosin structure organization, which were closely related to inflammation, pulmonary microcirculation, pulmonary fibrosis, and energy metabolism. XXZL up-regulated the content of CD31, and heat shock protein 60(HSP60) and ATP5 b mRNA expression, down-regulated interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), COL1 A1 content, and alleviated fibrosis, which suggested the obvious effects of XXZL such as anti-inflammation, pulmonary microcirculation improvement, pulmonary fibrosis inhibition, and energy metabolism regulation. This study explained the anti-pneumonia mechanism of XXZL from targets, which can serve as a reference for the clinical application of the prescription.