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1.
Sci Rep ; 14(1): 18618, 2024 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-39127850

RESUMO

This study aimed to investigate whether class A1 scavenger receptor (SR-A1) regulated macrophage polarization and gut microbial alteration during intestinal inflammation of colitis. A murine colitis model was established by feeding with dextran sulfate sodium (DSS), and treatment groups were injected intravenously with SR-A1 antibody. Results showed a preventive effect on colitis symptoms and fewer inflammatory cell infiltrates in treatment groups. Down-regulation of inflammatory cytokines and up-regulation of anti-inflammatory cytokine related to macrophages were seen in murine PBMC and LPMC after injected with SR-A1 antibody. The percentage of M2 macrophages was also elevated in treatment groups. In addition, SR-A1 antibody treatment resulted in the decreased apoptosis and increased proliferation of colonic epithelial cells. Other findings indicated that SR-A1 antibody injection could mediate its anti-inflammatory effect via inhibiting TLR4-MyD88-NF-kB signaling pathway and alterating the gut microbiota composition. Our research identified SR-A1 as a potential therapeutic target in inflammatory bowel disease (IBD).


Assuntos
Colite , Microbioma Gastrointestinal , Macrófagos , Receptores Depuradores Classe A , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Colite/imunologia , Colite/induzido quimicamente , Colite/microbiologia , Colite/metabolismo , Camundongos , Macrófagos/imunologia , Macrófagos/metabolismo , Receptores Depuradores Classe A/metabolismo , Sulfato de Dextrana/toxicidade , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Transdução de Sinais , Modelos Animais de Doenças , Citocinas/metabolismo , Anticorpos , NF-kappa B/metabolismo , Camundongos Endogâmicos C57BL , Masculino , Apoptose/efeitos dos fármacos
2.
Exp Cell Res ; 442(1): 114212, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39168433

RESUMO

Compared with young liver donors, aged liver donors are more susceptible to ischemia-reperfusion injury (IRI) following transplantation, which may be related to excessive inflammatory response and macrophage dysfunction, but the specific mechanism is unclear. Macrophage scavenger receptor 1 (MSR1) is a member of the scavenger receptor family, and plays an important regulatory role in inflammation response and macrophage function regulation. But its role in IRI following aged-donor liver transplantation is still unclear. This study demonstrates that MSR1 expression is decreased in macrophages from aged donor livers, inhibiting their efferocytosis and pro-resolving polarisation. Decreased MSR1 is responsible for the more severe IRI suffered by aged donor livers. Overexpression of MSR1 using F4/80-labelled AAV9 improved intrahepatic macrophage efferocytosis and promoted pro-resolving polarisation, ultimately ameliorating IRI following aged-donor liver transplantation. In vitro co-culture experiments further showed that overexpression of MSR1 promoted an increase in calcium concentration, which further activated the PI3K-AKT-GSK3ß pathway, and induced the upregulation of ß-catenin. Overall, MSR1-dependent efferocytosis promoted the pro-resolving polarisation of macrophages through the PI3K-AKT-GSK3ß pathway-induced up-regulating of ß-catenin leading to improved IRI following aged-donor liver transplantation.


Assuntos
Transplante de Fígado , Macrófagos , Camundongos Endogâmicos C57BL , Fagocitose , Traumatismo por Reperfusão , Receptores Depuradores Classe A , Animais , Transplante de Fígado/métodos , Transplante de Fígado/efeitos adversos , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/genética , Camundongos , Macrófagos/metabolismo , Masculino , Receptores Depuradores Classe A/metabolismo , Receptores Depuradores Classe A/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Fígado/metabolismo , Fígado/patologia , Transdução de Sinais , Doadores de Tecidos , Eferocitose
3.
Neurosci Lett ; 841: 137952, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39214333

RESUMO

The removal of axonal and myelin debris by macrophages is crucial for safeguarding nerves and facilitating functional recuperation in cerebral ischemic stroke. However, the physiological function of macrophage scavenger receptor 1 (MSR1) in ischemic white matter injury remains poorly de-fined. In this study, we observed an elevation in Msr1 expression levels in mice with experimental cerebral ischemic stroke. Msr 1-deficient (Msr1-/-) mice exhibited exacerbated behavioral deficits and aggravated white matter injury after ischemic stroke. Furthermore, the overexpression of Msr1 led to an increase in the phosphorylation of Akt via Hrh1, which in turn expedited the clearance of myelin debris through the PI3K/AKT pathway. In conclusion, our findings underscore the essential role of MSR1 in microglial phagocytosis and its ability to mitigate ischemic white matter injury in cerebral ischemic stroke.


Assuntos
Microglia , Fagocitose , Receptores Depuradores Classe A , Substância Branca , Animais , Microglia/metabolismo , Receptores Depuradores Classe A/metabolismo , Receptores Depuradores Classe A/genética , Fagocitose/fisiologia , Camundongos , Substância Branca/metabolismo , Substância Branca/patologia , Camundongos Endogâmicos C57BL , AVC Isquêmico/metabolismo , AVC Isquêmico/patologia , Masculino , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Camundongos Knockout , Proteínas Proto-Oncogênicas c-akt/metabolismo
4.
Mol Cell ; 84(11): 2104-2118.e6, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38761795

RESUMO

Circular RNAs (circRNAs) are stable RNAs present in cell-free RNA, which may comprise cellular debris and pathogen genomes. Here, we investigate the phenomenon and mechanism of cellular uptake and intracellular fate of exogenous circRNAs. Human myeloid cells and B cells selectively internalize extracellular circRNAs. Macrophage uptake of circRNA is rapid, energy dependent, and saturable. CircRNA uptake can lead to translation of encoded sequences and antigen presentation. The route of internalization influences immune activation after circRNA uptake, with distinct gene expression programs depending on the route of RNA delivery. Genome-scale CRISPR screens and chemical inhibitor studies nominate macrophage scavenger receptor MSR1, Toll-like receptors, and mTOR signaling as key regulators of receptor-mediated phagocytosis of circRNAs, a dominant pathway to internalize circRNAs in parallel to macropinocytosis. These results suggest that cell-free circRNA serves as an "eat me" signal and danger-associated molecular pattern, indicating orderly pathways of recognition and disposal.


Assuntos
Macrófagos , Fagocitose , RNA Circular , Transdução de Sinais , RNA Circular/genética , RNA Circular/metabolismo , Humanos , Macrófagos/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Serina-Treonina Quinases TOR/genética , Animais , Receptores Toll-Like/metabolismo , Receptores Toll-Like/genética , Linfócitos B/metabolismo , Linfócitos B/imunologia , Receptores Depuradores Classe A/metabolismo , Receptores Depuradores Classe A/genética , Apresentação de Antígeno , Pinocitose , Camundongos
5.
J Investig Med ; 72(4): 370-382, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38264863

RESUMO

Morinda officinalis polysaccharide (MOP) is the bioactive ingredient extracted from the root of Morinda officinalis, and Morinda officinalis is applied to treat osteoporosis (OP). The purpose of this study was to determine the role of MOP on human bone marrow mesenchymal stem cells (hBMSCs) and the underlying mechanism. HBMSCs were isolated from bone marrow samples of patients with OP and treated with MOP. Quantitative real-time polymerase chain reaction was adopted to quantify the expression of microRNA-210-3p (miR-210-3p) and scavenger receptor class A member 3 (SCARA3) mRNA. Cell Counting Kit-8 assay was employed to detect cell viability; Terminal-deoxynucleotidyl Transferase Mediated Nick End Labeling assay and flow cytometry were adopted to detect apoptosis; Alkaline Phosphatase (ALP) activity assay kit was applied to detect ALP activity; Western blot was executed to quantify the expression levels of SCARA3, osteogenic and adipogenic differentiation markers. Ovariectomized rats were treated with MOP. Bone mineral density (BMD), serum tartrate-resistant acid phosphatase 5b (TRACP 5b), and N-telopeptide of type I collagen (NTx) levels were assessed by BMD detector and Enzyme-linked immunosorbent assay kits. It was revealed that MOP could promote hBMSCs' viability and osteogenic differentiation and inhibit apoptosis and adipogenic differentiation. MOP could also upregulate SCARA3 expression through repressing miR-210-3p expression. Treatment with MOP increased the BMD and decreased the TRACP 5b and NTx levels in ovariectomized rats. MOP may boost the osteogenic differentiation and inhibit adipogenic differentiation of hBMSCs by miR-210-3p/SCARA3 axis.


Assuntos
Células-Tronco Mesenquimais , MicroRNAs , Morinda , Osteoporose , Polissacarídeos , Animais , Humanos , Ratos , Medula Óssea/metabolismo , Células Cultivadas , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/efeitos dos fármacos , MicroRNAs/metabolismo , Morinda/química , Morinda/metabolismo , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Osteoporose/tratamento farmacológico , Receptores Depuradores/metabolismo , Fosfatase Ácida Resistente a Tartarato/metabolismo , Polissacarídeos/farmacologia , Receptores Depuradores Classe A/efeitos dos fármacos , Receptores Depuradores Classe A/metabolismo
6.
ACS Appl Bio Mater ; 7(8): 4856-4866, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-38231485

RESUMO

Physiochemical properties of nanoparticles, such as their size and chemical composition, dictate their interaction with professional phagocytes of the innate immune system. Macrophages, in particular, are key regulators of the immune microenvironment that heavily influence particle biodistribution as a result of their uptake. This attribute enables macrophage-targeted delivery, including for phenotypic modulation. Saccharide-based materials, including polyglucose polymers and nanoparticles, are efficient vehicles for macrophage-targeted delivery. Here, we investigate the influence of particle size on cyclodextrin nanoparticle (CDNP) uptake by macrophages and further examine the receptor-mediated interactions that drive macrophage-targeted delivery. We designed and synthesized CDNPs ranging in size from 25 nm to >100 nm in diameter. Increasing particle size was correlated with greater uptake by macrophages in vitro. Both scavenger receptor A1 and mannose receptor were critical mediators of macrophage-targeted delivery, inhibition of which reduced the extent of uptake. Finally, we investigated the cellular bioavailability of drug-loaded CDNPs using a model anti-inflammatory drug, celastrol, which demonstrated that drug bioactivity is improved by CDNP loading relative to free drug alone. This study thus elucidates the interactions between the polyglucose nanoparticles and macrophages, thereby facilitating their application in macrophage-targeted drug delivery that has applications in the context of tissue injury and repair.


Assuntos
Ciclodextrinas , Macrófagos , Nanopartículas , Tamanho da Partícula , Nanopartículas/química , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Ciclodextrinas/química , Animais , Camundongos , Receptor de Manose , Células RAW 264.7 , Lectinas Tipo C/metabolismo , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/metabolismo , Teste de Materiais , Receptores de Superfície Celular/metabolismo , Receptores Depuradores Classe A/metabolismo , Lectinas de Ligação a Manose/metabolismo
7.
J Leukoc Biol ; 115(2): 322-333, 2024 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-37726110

RESUMO

Scavenger receptor A (SRA) is preferentially expressed in macrophages and implicated as a multifunctional pattern recognition receptor for innate immunity. Hepatic macrophages play a primary role in the pathogenesis of alcoholic liver disease. Herein, we observed that SRA expression was significantly increased in the liver tissues of mice with alcohol-related liver injury. SRA-deficient (SRA-/-) mice developed more severe alcohol-induced liver disease than wild-type mice. Enhanced liver inflammation existed in alcohol-challenged SRA-/- mice and was associated with increased Notch activation in hepatic macrophages compared with wild-type control animals. Mechanistically, SRA directly bound with Notch1 and suppressed its S-glutathionylation, thereby inhibiting Notch pathway activation. Further, we determined that the SRA interacted with thioredoxin-1 (Trx-1), a redox-active protein. SRA inhibited Trx-1 dimerization and facilitated the interaction of Trx-1 with Notch1. Application of a Trx-1-specific inhibitory agent during macrophage stimulation abolished SRA-mediated regulation of the Notch pathway and its downstream targets. In summary, our study revealed that SRA plays a critical role in macrophage inflammatory response by targeting Notch1 for its glutathionylation. SRA-mediated negative regulation of Notch activation might serve as a novel therapeutic strategy for alcohol-induced liver injury.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Camundongos , Animais , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Receptores Depuradores Classe A/metabolismo , Macrófagos/metabolismo , Receptores Depuradores/metabolismo , Fígado/metabolismo , Fatores Imunológicos , Etanol/toxicidade , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout
9.
Nat Commun ; 14(1): 4895, 2023 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-37580395

RESUMO

The opportunistic fungal pathogen Cryptococcus neoformans causes lethal infections in immunocompromised patients. Macrophages are central to the host response to cryptococci; however, it is unclear how C. neoformans is recognised and phagocytosed by macrophages. Here we investigate the role of TLR4 in the non-opsonic phagocytosis of C. neoformans. We find that loss of TLR4 function unexpectedly increases phagocytosis of non-opsonised cryptococci by murine and human macrophages. The increased phagocytosis observed in Tlr4-/- cells was dampened by pre-treatment of macrophages with oxidised-LDL, a known ligand of scavenger receptors. The scavenger receptor, macrophage scavenger receptor 1 (MSR1) (also known as SR-A1 or CD204) was upregulated in Tlr4-/- macrophages. Genetic ablation of MSR1 resulted in a 75% decrease in phagocytosis of non-opsonised cryptococci, strongly suggesting that it is a key non-opsonic receptor for this pathogen. We go on to show that MSR1-mediated uptake likely involves the formation of a multimolecular signalling complex involving FcγR leading to SYK, PI3K, p38 and ERK1/2 activation to drive actin remodelling and phagocytosis. Altogether, our data indicate a hitherto unidentified role for TLR4/MSR1 crosstalk in the non-opsonic phagocytosis of C. neoformans.


Assuntos
Criptococose , Fagocitose , Receptores Depuradores Classe A , Receptor 4 Toll-Like , Animais , Humanos , Camundongos , Cryptococcus neoformans , Macrófagos/microbiologia , Receptor 4 Toll-Like/genética , Receptores Depuradores Classe A/metabolismo
10.
Epigenomics ; 15(11): 635-650, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37554122

RESUMO

Background: SCARA5 may play an important role in nasopharyngeal carcinoma. Materials & methods: PCR and immunohistochemistry were used to detect the expression and promoter methylation of SCARA5. Cell proliferation assays, spheroid culture, flow cytometry analysis, Transwell assays and xenotransplantation tests were utilized to determine the functional effects of SCARA5. RNA-sequencing, western blotting, immunofluorescence and dual-luciferase reporter assays were used to assess SCARA5-mediated outcomes. Results: SCARA5 was downregulated by promoter methylation. Overexpression of SCARA5 inhibited cell migration, invasion and proliferation. SCARA5 enhanced nasopharyngeal carcinoma cell sensitivity to chemotherapy with cisplatin and 5-fluorouracil. SCARA5 drives tumor apoptosis by downregulating HSPA2. Conclusion: SCARA5 may be a useful clinical marker in nasopharyngeal carcinoma.


Assuntos
Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/genética , Linhagem Celular Tumoral , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/patologia , Genes Supressores de Tumor , Proliferação de Células/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Receptores Depuradores Classe A/genética , Receptores Depuradores Classe A/metabolismo
11.
Genomics ; 115(5): 110667, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37315873

RESUMO

Scavenger receptor class A, member 5 (SCARA5) has been identified a novel tumor suppressor in several cancers. However, the functional and underlying mechanism of SCARA5 in bladder cancer (BC) need investigation. Here, we found SCARA5 expression was downregulated in both BC tissues and cell lines. Low SCARA5 in BC tissues was associated with a shorter overall survival. Moreover, SCARA5 overexpression reduced BC cell viability, colony formation, invasion, and migration. Further investigation demonstrated that the expression of SCARA5 was negatively regulated by miR-141. Furthermore, the long non-coding RNA prostate cancer associated transcript 29 (PCAT29) inhibited the proliferation, invasion, and migration of BC cells by sponging miR-141. Luciferase activity assays revealed that PCAT29 targeted miR-141 and miR-141 targeted SCARA5. In conclusion, SCARA5, as a downstream factor of the PCAT29/miR-141 axis, inhibited the proliferation, migration, and invasion of BC cells. These findings provide novel insights into the detailed molecular mechanisms of BC development.


Assuntos
MicroRNAs , RNA Longo não Codificante , Neoplasias da Bexiga Urinária , Masculino , Humanos , Linhagem Celular Tumoral , Proliferação de Células/genética , Genes Supressores de Tumor , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , MicroRNAs/genética , Movimento Celular/genética , RNA Longo não Codificante/genética , Regulação Neoplásica da Expressão Gênica , Receptores Depuradores Classe A/genética , Receptores Depuradores Classe A/metabolismo
12.
Epigenomics ; 15(7): 401-415, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37337726

RESUMO

Aim: This study aimed to elucidate the relationship between SCARA5 and RMRP in bladder cancer and their underlying mechanism. Methods: Biological functions were evaluated using cell-counting kit 8 assay, 5-ethynyl-2'-deoxyuridine incorporation, wound healing and Transwell assays. RNA immunoprecipitation, RNA pull-down and chromatin immunoprecipitation were employed. A xenograft tumor model in nude mice was also conducted. Results & conclusion: RMRP and SCARA5 exhibited an inverse correlation. Downregulation of RMRP significantly suppressed bladder cancer cell proliferation, migration and invasion, which was reversed by SCARA5 overexpression. RMRP recruited DNA methyltransferases to the promoter region of SCARA5, thereby triggering the methylation of the SCARA5 promoter to epigenetically suppress its expression. Our findings elucidate the machinery by which RMRP, stabilized by METTL3, exerts a promoter role in bladder cancer tumorigenesis by triggering SCARA5 methylation.


Assuntos
MicroRNAs , RNA Longo não Codificante , Neoplasias da Bexiga Urinária , Animais , Camundongos , Humanos , Regulação para Cima , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Camundongos Nus , Neoplasias da Bexiga Urinária/genética , Ativação Transcricional , Proliferação de Células , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Metiltransferases/genética , Metiltransferases/metabolismo , Receptores Depuradores Classe A/genética , Receptores Depuradores Classe A/metabolismo
13.
Genomics ; 115(4): 110636, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37150230

RESUMO

Colorectal cancer (CRC) is the fourth most frequently diagnosed cancer worldwide. Bone marrow stromal cells (BMSCs) play an essential role in tumor development by secreting exosomes. Scavenger receptor class A member 5 (SCARA5) is a newly identified tumor suppressor. This study aimed to investigate the effects of BMSCs-derived exosomes (BMSCs-Exos) on CRC development and to explore their regulatory mechanisms. BMSCs-Exos showed an oval-shaped, bilayer membrane structure. BMSCs-Exos inhibited growth and motility of CRC cells, while BMSCs-Exos with SCARA5 knockdown significantly promoted cell proliferation and movement. Exosomal SCARA5 also effectively suppressed colorectal tumor growth in mouse xenografts. Further analysis revealed that exosomal SCARA5 inhibited the phosphorylation of protein kinase B and phosphoinositide 3-kinase in both CRC cells and tumors. In conclusion, SCARA5 in BMSCs-Exos inhibited CRC progression by inactivating PI3K/Akt, thus suggesting the potential clinical application of SCARA5-containing BMSCs-Exos for CRC treatment.


Assuntos
Neoplasias Colorretais , Exossomos , Células-Tronco Mesenquimais , MicroRNAs , Humanos , Camundongos , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Exossomos/metabolismo , Neoplasias Colorretais/metabolismo , Proliferação de Células , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/metabolismo , Receptores Depuradores Classe A/metabolismo
14.
BMC Genomics ; 24(1): 181, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-37020267

RESUMO

BACKGROUND: CircRNAs are involved in the pathogenesis of several central nervous system diseases. However, their functions and mechanisms in spinal cord injury (SCI) are still unclear. Therefore, the purpose of this study was to evaluate circRNA and mRNA expression profiles in the pathological setting of SCI and to predict the potential function of circRNA through bioinformatics. METHODS: A microarray-based approach was used for the simultaneous measurement of circRNAs and mRNAs, together with qPCR, fluorescence in situ hybridization, western immunoblotting, and dual-luciferase reporter assays to investigate the associated regulatory mechanisms in a rat SCI model. RESULTS: SCI was found to be associated with the differential expression of 414 and 5337 circRNAs and mRNAs, respectively. Pathway enrichment analyses were used to predict the primary function of these circRNAs and mRNAs. GSEA analysis showed that differentially expressed mRNAs were primarily associated with inflammatory immune response activity. Further screening of these inflammation-associated genes was used to construct and analyze a competing endogenous RNA network. RNO_CIRCpedia_4214 was knocked down in vitro, resulting in reduced expression of Msr1, while the expression of RNO-miR-667-5p and Arg1 was increased. Dual-luciferase assays demonstrated that RNO_CIRCpedia_4214 bound to RNO-miR-667-5p. The RNO_CIRCpedia_4214/RNO-miR-667-5p/Msr1 axis may be a potential ceRNA that promotes macrophage M2-like polarization in SCI. CONCLUSION: Overall, these results highlighted the critical role that circRNAs may play in the pathophysiology of SCI and the discovery of a potential ceRNA mechanism based on novel circRNAs that regulates macrophage polarization, providing new targets for the treatment of SCI.


Assuntos
MicroRNAs , Traumatismos da Medula Espinal , Animais , Ratos , Hibridização in Situ Fluorescente , Luciferases/genética , MicroRNAs/genética , RNA Circular/genética , RNA Mensageiro/genética , Traumatismos da Medula Espinal/genética , Receptores Depuradores Classe A/metabolismo
15.
Sci Rep ; 13(1): 2651, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36788340

RESUMO

Obesity induces a chronic inflammatory state associated with changes in adipose tissue macrophages (ATMs). Macrophage scavenger receptor 1 (MSR1) has been implicated in the regulation of adipose tissue inflammation and diabetes pathogenesis; however, reports have been mixed on the contribution of MSR1 in obesity and glucose intolerance. We observed increased MSR1 expression in VAT of obese diabetic individuals compared to non-diabetic and single nuclear RNA sequencing identified macrophage-specific expression of MSR1 in human adipose tissue. We examined male Msr1-/- (Msr1KO) and WT controls and observed protection from obesity and AT inflammation in non-littermate Msr1KO mice. We then evaluated obese littermate Msr1+/- (Msr1HET) and Msr1KO mice. Both Msr1KO mice and Msr1HET mice became obese and insulin resistant when compared to their normal chow diet counterparts, but there was no Msr1-dependent difference in body weight, glucose metabolism, or insulin resistance. Flow cytometry revealed no significant differences between genotypes in ATM subtypes or proliferation in male and female mice. We observed increased frequency of proliferating ATMs in obese female compared to male mice. Overall, we conclude that while MSR1 is a biomarker of diabetes status in human adipose tissue, in mice Msr1 is not required for obesity-associated insulin resistance or ATM accumulation.


Assuntos
Resistência à Insulina , Obesidade , Receptores Depuradores Classe A , Animais , Feminino , Masculino , Camundongos , Tecido Adiposo/metabolismo , Inflamação/metabolismo , Insulina/metabolismo , Resistência à Insulina/genética , Camundongos Endogâmicos C57BL , Obesidade/complicações , Obesidade/genética , Obesidade/metabolismo , Receptores Depuradores Classe A/metabolismo
16.
Int J Mol Sci ; 24(3)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36768908

RESUMO

Hydrocephalus has been observed in rats with spontaneous hypertension (SHRs). It has been demonstrated that activation of the oxidative stress related protein retinoic acid receptor alpha (RARα) has neuroprotective impacts. Our investigation aims to determine the potential role and mechanism of RARα in hydrocephalus. The RARα-specific agonist (Am80) and RARα inhibitor (AGN196996) were used to investigate the role of RARα in cerebrospinal fluid (CSF) secretion in the choroid plexus of SHRs. Evaluations of CSF secretion, ventricular volume, Western blotting, and immunofluorescent staining were performed. Hydrocephalus and CSF hypersecretion were identified in SHRs but not in Wistar-Kyoto rats, occurring at the age of 7 weeks. The RARα/MAFB/MSR1 pathway was also activated in SHRs. Therapy with Am80 beginning in week 5 decreased CSF hypersecretion, hydrocephalus development, and pathological changes in choroid plexus alterations by week 7. AGN196996 abolished the effect of Am80. In conclusion, activation of the RARα attenuated CSF hypersecretion to inhibit hydrocephalus development via regulating the MAFB/MSR1 pathway. RARα may act as a possible therapeutic target for hydrocephalus.


Assuntos
Hidrocefalia , Hipertensão , Animais , Ratos , Plexo Corióideo/metabolismo , Hidrocefalia/metabolismo , Hipertensão/metabolismo , Fator de Transcrição MafB/metabolismo , Proteínas Oncogênicas/metabolismo , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Receptores Depuradores Classe A/metabolismo
17.
J Pharmacol Sci ; 151(1): 46-53, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36522122

RESUMO

Atherosclerotic plaques develop from the accumulation of macrophage-derived foam cells via the uptake of modified low-density lipoprotein (LDL). CD36 and CD204 are the principal scavenger receptors responsible for the uptake of modified LDL. Although glucocorticoids are suspected to exacerbate atherosclerosis, the precise mechanisms have not been fully elucidated. We investigated the effects of long-term treatment (2 weeks) with both a natural glucocorticoid (hydrocortisone, HC, 1 µM) and a synthetic glucocorticoid (dexamethasone, Dex, 100 nM) on murine bone marrow-derived macrophages using flow cytometry and western blotting. Treatment with HC and Dex enhanced CD204 expression but not CD36 expression and acetylated LDL (Ac-LDL) uptake. Treatment with HC and Dex also induced the phosphorylation of extracellular signal-regulated kinase (ERK). The Dex-induced enhancement in CD204 expression and Ac-LDL uptake were suppressed by an inhibitor of the mitogen-activated protein kinase (MAPK)/ERK kinase. These results suggest that glucocorticoids activate the MAPK/ERK pathway, which enhances CD204 expression and results in increased uptake of Ac-LDL in macrophages. The MAPK/ERK pathway in macrophages might be a key target to prevent atherosclerosis that is worsened by glucocorticoids.


Assuntos
Aterosclerose , Receptores Depuradores Classe A , Camundongos , Animais , Receptores Depuradores Classe A/metabolismo , Glucocorticoides/farmacologia , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Antígenos CD36/genética , Antígenos CD36/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Aterosclerose/tratamento farmacológico , Aterosclerose/metabolismo
18.
Front Immunol ; 13: 1012002, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36325338

RESUMO

Macrophage scavenger receptor 1 (MSR1), also named CD204, holds key inflammatory roles in multiple pathophysiologic processes. Present primarily on the surface of various types of macrophage, this receptor variably affects processes such as atherosclerosis, innate and adaptive immunity, lung and liver disease, and more recently, cancer. As highlighted throughout this review, the role of MSR1 is often dichotomous, being either host protective or detrimental to the pathogenesis of disease. We will discuss the role of MSR1 in health and disease with a focus on the molecular mechanisms influencing MSR1 expression, how altered expression affects disease process and macrophage function, the limited cell signalling pathways discovered thus far, the emerging role of MSR1 in tumour associated macrophages as well as the therapeutic potential of targeting MSR1.


Assuntos
Neoplasias , Receptores Depuradores Classe A , Humanos , Receptores Depuradores Classe A/genética , Receptores Depuradores Classe A/metabolismo , Macrófagos/metabolismo , Pulmão/metabolismo , Transdução de Sinais , Neoplasias/genética , Neoplasias/metabolismo
19.
Microbiol Spectr ; 10(6): e0202822, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36342281

RESUMO

The innate immune system is the first line of host defense against microbial infections. During virus infection, pattern recognition receptors (PRRs) are engaged to detect specific viral components, such as viral RNA or DNA, and regulate the innate immune response in the infected cells or immune cells. Our previous study demonstrated that scavenger receptor A (SRA), an important innate PRR, impaired the anti-hepatitis B virus (HBV) response in hepatocytes. Given that SRA is primarily expressed in macrophages, here, we assessed the function of SRA expressed in macrophages in response to RNA or DNA viral infection. SRA-deficient (SRA-/-) mice showed reduced susceptibility to viral infection caused by vesicular stomatitis virus (VSV) or herpes simplex virus 1 (HSV-1). In the virus-infected SRA-/- mice, compared with their wild-type (WT) counterparts, we observed low amounts of virus accompanied by enhanced interferon (IFN) production. Furthermore, SRA significantly inhibited the phosphorylation of TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3). We provided biochemical evidence showing that SRA directly interacts with the N-terminal kinase domain (KD) of TBK1, resulting in the limitation of its K63-linked ubiquitination. Moreover, we demonstrated that SRA negatively regulates the activity of TBK1 by promoting the recruitment of ubiquitin-specific protease 15 (USP15) to deubiquitinate TBK1. In summary, we have identified the connection between SRA and the TBK1/IRF3 signaling pathway in macrophages, indicating a critical role of SRA in the regulation of host antiviral immunity. IMPORTANCE During virus infection, PRRs are engaged to detect specific viral components, such as viral RNA or DNA, and regulate the innate immune response in the infected cells or other immune cells. We reported that deficiency of SRA, an important innate PRR, promoted IRF3 activation, type I IFN production, and innate antiviral responses against RNA and DNA viruses in vivo and in vitro. Furthermore, the biochemical analysis showed that SRA directly interacts with the KD domain of TBK1 and limits its K63-linked polyubiquitination, reducing TBK1 activation. Further analyses determined that SRA is a modulator for TBK1 activation via the recruitment of USP15, which delineated a previously unrecognized function for SRA in innate antiviral immunity.


Assuntos
Interações Hospedeiro-Patógeno , Interferon beta , Proteínas Serina-Treonina Quinases , Receptores Depuradores Classe A , Proteases Específicas de Ubiquitina , Animais , Camundongos , Antivirais , Enzimas Desubiquitinantes/genética , Enzimas Desubiquitinantes/metabolismo , Imunidade Inata , Macrófagos/metabolismo , Proteínas Serina-Treonina Quinases/genética , RNA/metabolismo , Proteases Específicas de Ubiquitina/genética , Proteases Específicas de Ubiquitina/metabolismo , Ubiquitinação , Receptores Depuradores Classe A/genética , Receptores Depuradores Classe A/metabolismo
20.
Nat Commun ; 13(1): 6804, 2022 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-36357401

RESUMO

Hyperferritinemic syndrome, an overwhelming inflammatory condition, is characterized by high ferritin levels, systemic inflammation and multi-organ dysfunction, but the pathogenic role of ferritin remains largely unknown. Here we show in an animal model that ferritin administration leads to systemic and hepatic inflammation characterized by excessive neutrophil leukocyte infiltration and neutrophil extracellular trap (NET) formation in the liver tissue. Ferritin-induced NET formation depends on the expression of peptidylarginine deiminase 4 and neutrophil elastase and on reactive oxygen species production. Mechanistically, ferritin exposure increases both overall and cell surface expression of Msr1 on neutrophil leukocytes, and also acts as ligand to Msr1 to trigger the NET formation pathway. Depletion of neutrophil leukocytes or ablation of Msr1 protect mice from tissue damage and the hyperinflammatory response, which further confirms the role of Msr1 as ferritin receptor. The relevance of the animal model is underscored by the observation that enhanced NET formation, increased Msr1 expression and signalling on neutrophil leukocytes are also characteristic to adult-onset Still's disease (AOSD), a typical hyperferritinemic syndrome. Collectively, our findings demonstrate an essential role of ferritin in NET-mediated cytokine storm, and suggest that targeting NETs or Msr1 may benefit AOSD patients.


Assuntos
Armadilhas Extracelulares , Doença de Still de Início Tardio , Camundongos , Animais , Doença de Still de Início Tardio/metabolismo , Armadilhas Extracelulares/metabolismo , Síndrome da Liberação de Citocina , Ferritinas/metabolismo , Inflamação/metabolismo , Receptores Depuradores Classe A/metabolismo
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