ABSTRACT
BACKGROUND: Reactive microglia and recruited peripheral macrophages contribute to the pathogenesis of Alzheimer's dementia (AD). Monocytes, macrophages and microglia all express the marker colony-stimulating factor 1 receptor (CSF1R). 4-Cyano-N-(4-(4-methylpiperazin-1-yl)-2-(4-methylpiperidin-1-yl)phenyl)-1H-pyrrole-2-carboxamide (1) is a high-affinity antagonist for CSF1R. We report the radiosynthesis of both [3H]1 and [11C]1. The PET imaging properties of [11C]1 in mice and baboon were investigated. [3H]1 was studied in Bmax measurement in post-mortem autoradiography in the frontal cortex, inferior parietal cortex and hippocampus from donors diagnosed with AD and age-matched controls. In vitro binding affinity of 1 was measured commercially. Nor-methyl-1 precursor was radiolabeled with [11C]iodomethane or [3H]iodomethane to produce [11C]1 and [3H]1, respectively. Ex vivo brain biodistribution of [11C]1 was compared in normal mice versus lipopolysaccharide-administered (LPS) murine model of neuroinflammation. Dynamic PET imaging was performed in a healthy male Papio anubis baboon. Post-mortem autoradiography with [3H]1 was performed in frozen sections using a standard saturation binding technique. RESULTS: Compound 1 exhibits a high in vitro CSF1R binding affinity (0.59 nM). [11C]1 was synthesized with high yield. [3H]1 was synthesized similarly (commercially). Biodistribution of [11C]1 in healthy mice demonstrated moderate brain uptake. In LPS-treated mice the brain uptake of [11C]1 was ~ 50% specific for CSF1R. PET/CT [11C]1 study in baboon revealed low brain uptake (0.36 SUV) of [11C]1. Autoradiography with [3H]1 gave significantly elevated Bmax values in AD frontal cortex versus control (47.78 ± 26.80 fmol/mg vs. 12.80 ± 5.30 fmol/mg, respectively, P = 0.023) and elevated, but not significantly different binding in AD hippocampus grey matter and inferior parietal cortex (IPC) white matter. CONCLUSIONS: Compound 1 exhibits a high in vitro CSF1R binding affinity. [11C]1 specifically labels CSF1R in the mouse neuroinflammation, but lacks the ability to efficiently cross the blood-brain barrier in baboon PET. [3H]1 specifically labels CSF1R in post-mortem human brain. The binding of [3H]1 is significantly higher in the post-mortem frontal cortex of AD versus control subjects.
ABSTRACT
Colony stimulating factor 1 receptor (CSF1R) is an essential receptor for both colony stimulating factor 1 (CSF1) and interleukin (IL) 34 signaling expressed on monocyte precursors and myeloid cells, including monocytes, dendritic cells (DC), and microglia. In humans, dominant heterozygous pathogenic variants in CSF1R cause a neurological condition known as CSF1R-related disorder (CSF1R-RD), typically with late onset, previously referred to as adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP). CSF1R-RD is characterized by microglia reduction and altered monocyte function; however, the impact of pathogenic CSF1R variants on the human DC lineage remains largely unknown. We previously reported that cord blood CD34+ stem cell-derived DCs generated in vitro originate specifically from CSF1R expressing precursors. In this study, we examined the DC lineage of four unrelated patients with late-onset CSF1R-RD who carried heterozygous missense CSF1R variants (c.2330G>A, c.2375C>A, c.2329C>T, and c.2381T>C) affecting different amino acids in the protein tyrosine kinase domain of CSF1R. CD34+ stem cells and CD14+ monocytes were isolated from peripheral blood and subjected to an in vitro culture protocol to differentiate towards conventional DCs and monocyte-derived DCs, respectively. Flow cytometric analysis revealed that monocytes from patients with late-onset CSF1R-RD were still able to differentiate into monocyte-derived DCs in vitro, whereas the ability of CD34+ stem cells to differentiate into conventional DCs was impaired. Strikingly, the peripheral blood of patients contained all naturally occurring DC subsets. We conclude that the in vitro abrogation of DC-development in patients with heterozygous pathogenic missense CSF1R variants does not translate to an impairment in DC development in vivo and speculate that CSF1R signalling in vivo is compensated, which needs further study.
ABSTRACT
Parkinson's Disease (PD) remains a significant focus of extensive research aimed at developing effective therapeutic strategies. Current treatments primarily target symptom management, with limited success in altering the course of the disease. This shortfall underscores the urgent need for novel therapeutic approaches that can modify the progression of PD.This review concentrates on emerging therapeutic targets poised to address the underlying mechanisms of PD. Highlighted novel and emerging targets include Protein Abelson, Rabphilin-3 A, Colony Stimulating Factor 1-Receptor, and Apelin, each showing promising potential in preclinical and clinical settings for their ability to modulate disease progression. By examining recent advancements and outcomes from trials focusing on these targets, the review aims to elucidate their efficacy and potential as disease-modifying therapies.Furthermore, the review explores the concept of multi-target approaches, emphasizing their relevance in tackling the complex pathology of PD. By providing comprehensive insights into these novel targets and their therapeutic implications, this review aims to guide future research directions and clinical developments toward more effective treatments for PD and related neurodegenerative disorders.
Subject(s)
Parkinson Disease , Humans , Parkinson Disease/drug therapy , Parkinson Disease/therapy , Parkinson Disease/metabolism , Animals , Antiparkinson Agents/therapeutic use , Molecular Targeted Therapy/methodsABSTRACT
Colony-stimulating factor 1 receptor (CSF1R) is a type III receptor tyrosine kinase that is crucial for immune cell activation, survival, proliferation, and differentiation. Its expression significantly increases in macrophages during inflammation, playing a crucial role in regulating inflammation resolution and termination. Consequently, CSF1R has emerged as a critical target for both therapeutic intervention and imaging of inflammatory diseases. Herein, we have developed a radiotracer, 1-[4-((7-(dimethylamino)quinazolin-4-yl)oxy)phenyl]-3-(4-[18F]fluorophenyl)urea ([18F]17), for in vivo positron emission tomography (PET) imaging of CSF1R. Compound 17 exhibits a comparable inhibitory potency against CSF1R as the well-known CSF1R inhibitor PLX647. The radiosynthesis of [18F]17 was successfully performed by radiofluorination of aryltrimethyltin precursor with a yield of approximately 12% at the end of synthesis, maintaining a purity exceeding 98%. In vivo stability and biodistribution studies demonstrate that [18F]17 remains >90% intact at 30 min postinjection, with no defluorination observed even at 60 min postinjection. The PET/CT imaging study in lipopolysaccharide-induced pulmonary inflammation mice indicates that [18F]17 offers a more sensitive characterization of pulmonary inflammation compared to traditional [18F]FDG. Notably, [18F]17 shows a higher discrepancy in uptake ratio between mice with pulmonary inflammation and the sham group. Furthermore, the variations in [18F]17 uptake ratio observed on day 7 and day 14 correspond to lung density changes observed in CT imaging. Moreover, the expression levels of CSF1R on day 7 and day 14 follow a trend similar to the uptake pattern of [18F]17, indicating its potential for accurately characterizing CSF1R expression levels and effectively monitoring the pulmonary inflammation progression. These results strongly suggest that [18F]17 has promising prospects as a CSF1R PET tracer, providing diagnostic opportunities for pulmonary inflammatory diseases.
Subject(s)
Pneumonia , Positron-Emission Tomography , Radiopharmaceuticals , Animals , Mice , Pneumonia/diagnostic imaging , Pneumonia/metabolism , Positron-Emission Tomography/methods , Radiopharmaceuticals/pharmacokinetics , Tissue Distribution , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Fluorine Radioisotopes , Humans , Male , Mice, Inbred C57BL , Lung/diagnostic imaging , Lung/metabolismABSTRACT
Bone resorption is driven through osteoclast differentiation by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-Β ligand (RANKL). We noted that a disintegrin and metalloproteinase (ADAM) 10 and ADAM17 are downregulated at the expression level during osteoclast differentiation of the murine monocytic cell line RAW264.7 in response to RANKL. Both proteinases are well known to shed a variety of single-pass transmembrane molecules from the cell surface. We further showed that inhibitors of ADAM10 or ADAM17 promote osteoclastic differentiation and furthermore enhance the surface expression of receptors for RANKL and M-CSF on RAW264.7 cells. Using murine bone marrow-derived monocytic cells (BMDMCs), we demonstrated that a genetic deficiency of ADAM17 or its required regulator iRhom2 leads to increased osteoclast development in response to M-CSF and RANKL stimulation. Moreover, ADAM17-deficient osteoclast precursor cells express increased levels of the receptors for RANKL and M-CSF. Thus, ADAM17 negatively regulates osteoclast differentiation, most likely through shedding of these receptors. To assess the time-dependent contribution of ADAM10, we blocked this proteinase by adding a specific inhibitor on day 0 of BMDMC stimulation with M-CSF or on day 7 of subsequent stimulation with RANKL. Only ADAM10 inhibition beginning on day 7 increased the size of developing osteoclasts indicating that ADAM10 suppresses osteoclast differentiation at a later stage. Finally, we could confirm our findings in human peripheral blood mononuclear cells (PBMCs). Thus, downregulation of either ADAM10 or ADAM17 during osteoclast differentiation may represent a novel regulatory mechanism to enhance their differentiation process. Enhanced bone resorption is a critical issue in osteoporosis and is driven through osteoclast differentiation by specific osteogenic mediators. The present study demonstrated that the metalloproteinases ADAM17 and ADAM10 critically suppress osteoclast development. This was observed for a murine cell line, for isolated murine bone marrow cells and for human blood cells by either preferential inhibition of the proteinases or by gene knockout. As a possible mechanism, we studied the surface expression of critical receptors for osteogenic mediators on developing osteoclasts. Our findings revealed that the suppressive effects of ADAM17 and ADAM10 on osteoclastogenesis can be explained in part by the proteolytic cleavage of surface receptors by ADAM10 and ADAM17, which reduces the sensitivity of these cells to osteogenic mediators. We also observed that osteoclast differentiation was associated with the downregulation of ADAM10 and ADAM17, which reduced their suppressive effects. We therefore propose that this downregulation serves as a feedback loop for enhancing osteoclast development.
Subject(s)
ADAM10 Protein , ADAM17 Protein , Amyloid Precursor Protein Secretases , Cell Differentiation , Down-Regulation , Membrane Proteins , Osteoclasts , RANK Ligand , ADAM17 Protein/metabolism , ADAM17 Protein/genetics , ADAM10 Protein/metabolism , ADAM10 Protein/genetics , Osteoclasts/metabolism , Osteoclasts/cytology , Animals , Cell Differentiation/genetics , Mice , Down-Regulation/genetics , Amyloid Precursor Protein Secretases/metabolism , Amyloid Precursor Protein Secretases/genetics , Membrane Proteins/metabolism , Membrane Proteins/genetics , Humans , RANK Ligand/metabolism , RAW 264.7 Cells , Macrophage Colony-Stimulating Factor/pharmacology , Macrophage Colony-Stimulating Factor/metabolism , Mice, Inbred C57BLABSTRACT
Immunotherapeutic effect is restricted by the nonimmunogenic tumor phenotype and immunosuppression behaviors of tumor-associated macrophages (TAMs). In this work, a drug self-assembly (designated as CeBLZ) is fabricated based on chlorin e6 (Ce6) and BLZ945 to activate photodynamic immunotherapy through tumor immunogenic induction and tumor-associated macrophage depletion. It is found that Ce6 tends to assemble with BLZ945 without any drug excipients, which can enhance the cellular uptake, tumor penetration, and blood circulation behaviors. The robust photodynamic therapy effect of CeBLZ efficiently suppresses the primary tumor growth and also triggers immunogenic cell death to reverse the nonimmunogenic tumor phenotype. Moreover, CeBLZ can deplete TAMs in tumor tissues to reverse the immunosuppression microenvironment, activating abscopal effect for distant tumor inhibition. In vitro and in vivo results confirm the superior antitumor effect of CeBLZ with negligible side effect, which might promote the development of sophisticated drug combinations for systematic tumor management.
Subject(s)
Chlorophyllides , Immunotherapy , Photochemotherapy , Porphyrins , Tumor-Associated Macrophages , Porphyrins/chemistry , Porphyrins/pharmacology , Animals , Photochemotherapy/methods , Tumor-Associated Macrophages/drug effects , Tumor-Associated Macrophages/immunology , Mice , Immunotherapy/methods , Cell Line, Tumor , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Humans , Female , RAW 264.7 Cells , Tumor Microenvironment/drug effects , Mice, Inbred BALB CABSTRACT
Mesenchymal stem/stromal cells (MSCs) modulate the immune response through interactions with innate immune cells. We previously demonstrated that MSCs alleviate ocular autoimmune inflammation by directing bone marrow cell differentiation from pro-inflammatory CD11bhiLy6ChiLy6Glo cells into immunosuppressive CD11bmidLy6CmidLy6Glo cells. Herein, we analyzed MSC-induced CD11bmidLy6Cmid cells using single-cell RNA sequencing and compared them with CD11bhiLy6Chi cells. Our investigation revealed seven distinct immune cell types including myeloid-derived suppressor cells (MDSCs) in the CD11bmidLy6Cmid cells, while CD11bhiLy6Chi cells included mostly monocytes/macrophages with a small cluster of neutrophils. These MSC-induced MDSCs highly expressed Retnlg, Cxcl3, Cxcl2, Mmp8, Cd14, and Csf1r as well as Arg1. Comparative analyses of CSF-1RhiCD11bmidLy6Cmid and CSF-1RloCD11bmidLy6Cmid cells demonstrated that the former had a homogeneous monocyte morphology and produced elevated levels of interleukin-10. Functionally, these CSF-1RhiCD11bmidLy6Cmid cells, compared with the CSF-1RloCD11bmidLy6Cmid cells, inhibited CD4+ T cell proliferation and promoted CD4+CD25+Foxp3+ Treg expansion in culture and in a mouse model of experimental autoimmune uveoretinitis. Resistin-like molecule (RELM)-γ encoded by Retnlg, one of the highly upregulated genes in MSC-induced MDSCs, had no direct effects on T cell proliferation, Treg expansion, or splenocyte activation. Together, our study revealed a distinct transcriptional profile of MSC-induced MDSCs and identified CSF-1R as a key cell-surface marker for detection and therapeutic enrichment of MDSCs.
Subject(s)
Mesenchymal Stem Cells , Myeloid-Derived Suppressor Cells , Single-Cell Analysis , Animals , Mice , Mesenchymal Stem Cells/metabolism , Mesenchymal Stem Cells/cytology , Myeloid-Derived Suppressor Cells/metabolism , Myeloid-Derived Suppressor Cells/immunology , Single-Cell Analysis/methods , Transcriptome , Cell Differentiation/genetics , Gene Expression Profiling , Disease Models, Animal , Uveitis/genetics , Uveitis/immunology , Uveitis/metabolism , HumansABSTRACT
BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disorder that is characterized by the presence of proteinaceous alpha-synuclein (α-syn) inclusions (Lewy bodies), markers of neuroinflammation and the progressive loss of nigrostriatal dopamine (DA) neurons. These pathological features can be recapitulated in vivo using the α-syn preformed fibril (PFF) model of synucleinopathy. We have previously determined that microglia proximal to PFF-induced nigral α-syn inclusions increase in soma size, upregulate major-histocompatibility complex-II (MHC-II) expression, and increase expression of a suite of inflammation-associated transcripts. This microglial response is observed months prior to degeneration, suggesting that microglia reacting to α-syn inclusion may contribute to neurodegeneration and could represent a potential target for novel therapeutics. The goal of this study was to determine whether colony stimulating factor-1 receptor (CSF1R)-mediated microglial depletion impacts the magnitude of α-syn aggregation, nigrostriatal degeneration, or the response of microglial in the context of the α-syn PFF model. METHODS: Male Fischer 344 rats were injected intrastriatally with either α-syn PFFs or saline. Rats were continuously administered Pexidartinib (PLX3397B, 600 mg/kg), a CSF1R inhibitor, to deplete microglia for a period of either 2 or 6 months. RESULTS: CSF1R inhibition resulted in significant depletion (~ 43%) of ionized calcium-binding adapter molecule 1 immunoreactive (Iba-1ir) microglia within the SNpc. However, CSF1R inhibition did not impact the increase in microglial number, soma size, number of MHC-II immunoreactive microglia or microglial expression of Cd74, Cxcl10, Rt-1a2, Grn, Csf1r, Tyrobp, and Fcer1g associated with phosphorylated α-syn (pSyn) nigral inclusions. Further, accumulation of pSyn and degeneration of nigral neurons was not impacted by CSF1R inhibition. Paradoxically, long term CSF1R inhibition resulted in increased soma size of remaining Iba-1ir microglia in both control and PFF rats, as well as expression of MHC-II in extranigral regions. CONCLUSIONS: Collectively, our results suggest that CSF1R inhibition does not impact the microglial response to nigral pSyn inclusions and that CSF1R inhibition is not a viable disease-modifying strategy for PD.
Subject(s)
Microglia , Rats, Inbred F344 , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor , alpha-Synuclein , Animals , Microglia/metabolism , Microglia/drug effects , alpha-Synuclein/metabolism , Rats , Male , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Pyrroles/pharmacology , Aminopyridines/pharmacology , Inclusion Bodies/metabolism , Inclusion Bodies/pathology , Substantia Nigra/metabolism , Substantia Nigra/pathology , Substantia Nigra/drug effects , Disease Models, AnimalABSTRACT
Microglia are the residential immune cells in the central nervous system. Their roles as innate immune cells and regulators of synaptic remodeling are critical to the development and the maintenance of the brain. Numerous studies have depleted microglia to elucidate their involvement in healthy and pathological conditions. PLX3397, a blocker of colony stimulating factor 1 receptor (CSF1R), is widely used to deplete mouse microglia due to its non-invasiveness and convenience. Recently, other small rodents, including Syrian hamsters (Mesocricetus auratus) and Mongolian gerbils (Meriones unguiculatus), have been recognized as valuable animal models for studying brain functions and diseases. However, whether microglia depletion via PLX3397 is feasible in these species remains unclear. Here, we administered PLX3397 orally via food pellets to hamsters and gerbils. PLX3397 successfully depleted gerbil microglia but had no effect on microglial density in hamsters. Comparative analysis of the CSF1R amino acid sequence in different species hints that amino acid substitutions in the juxtamembrane domain may potentially contribute to the inefficacy of PLX3397 in hamsters.
Subject(s)
Aminopyridines , Brain , Gerbillinae , Microglia , Pyrroles , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor , Animals , Cricetinae , Administration, Oral , Aminopyridines/pharmacology , Brain/drug effects , Brain/metabolism , Brain/cytology , Mesocricetus , Microglia/drug effects , Microglia/metabolism , Models, Animal , Pyrroles/pharmacology , Pyrrolidines/pharmacology , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Species SpecificityABSTRACT
Leukoencephalopathy (LE), characterized by structural changes affecting cerebral white matter, presents a complex clinical picture with diverse etiologies. This case report details the presentation, clinical findings, and physiotherapy management of a 32-year-old female with colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy and a history of diabetes and hypertension. She suddenly stopped her medications, which led to the worsening of her condition. She presented with symptoms of headache, slurred speech, visual disturbances, cognitive impairment, and impaired balance and coordination, due to which her activities of daily living were affected. The symptoms highlighted the challenges and multidisciplinary approach required for its management. The patient exhibited neurological deficits, cognitive decline, and abnormal reflexes, with magnetic resonance imaging (MRI) revealing white matter abnormalities. Outcome measures demonstrated significant improvements in cognitive and functional abilities, emphasizing the effectiveness of tailored rehabilitation in managing the complexities of colony-stimulating factor 1 receptor-related leukoencephalopathy. A six-week physiotherapy rehabilitation program addressed various domains, including strength training, task-specific exercises, errorless learning, facial muscle retraining, balance exercises, visual restoration therapy, and mobility training. All these interventions effectively improved her functional capacity and made the patient independent in performing activities of daily living.
ABSTRACT
BACKGROUND: Colony-stimulating factor 1 receptor (CSF1R)-related disorder (CRD) is a rare autosomal dominant disease. The clinical and genetic characteristics of Chinese patients have not been elucidated. OBJECTIVE: The objective of the study is to clarify the core features and influence factors of CRD patients in China. METHODS: Clinical and genetic-related data of CRD patients in China were collected. Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Sundal MRI Severity Score were evaluated. Whole exome sequencing was used to analyze the CSF1R mutation status. Patients were compared between different sexes, mutation types, or mutation locations. RESULTS: A total of 103 patients were included, with a male-to-female ratio of 1:1.51. The average age of onset was (40.75 ± 8.58). Cognitive impairment (85.1%, 86/101) and parkinsonism (76.2%, 77/101) were the main clinical symptoms. The most common imaging feature was bilateral asymmetric white matter changes (100.0%). A total of 66 CSF1R gene mutants (22 novel mutations) were found, and 15 of 92 probands carried c.2381 T > C/p.I794T (16.30%). The MMSE and MoCA scores (17.0 [9.0], 11.90 ± 7.16) of female patients were significantly lower than those of male patients (23.0 [10.0], 16.36 ± 7.89), and the white matter severity score (20.19 ± 8.47) of female patients was significantly higher than that of male patients (16.00 ± 7.62). There is no statistical difference in age of onset between male and female patients. CONCLUSIONS: The core manifestations of Chinese CRD patients are progressive cognitive decline, parkinsonism, and bilateral asymmetric white matter changes. Compared to men, women have more severe cognitive impairment and imaging changes. c.2381 T > C/p.I794T is a hotspot mutation in Chinese patients. © 2024 International Parkinson and Movement Disorder Society.
Subject(s)
Mutation , Phenotype , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor , Humans , Male , Female , Adult , Middle Aged , China/epidemiology , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Mutation/genetics , Genotype , Cognitive Dysfunction/genetics , Magnetic Resonance Imaging , Parkinsonian Disorders/genetics , Aged , Age of Onset , Young Adult , Receptor, Macrophage Colony-Stimulating FactorABSTRACT
Myeloid immune cells are abundant in both ruptured and unruptured brain arteriovenous malformations (bAVMs). The role of central nervous system (CNS) resident and circulating monocyte-derived macrophages in bAVM pathogenesis has not been fully understood. We hypothesize that CNS resident macrophages enhance bAVM development and hemorrhage. RNA sequencing using cultured endothelial cells (ECs) and mouse bAVM samples revealed that downregulation of two bAVM causative genes, activin-like kinase 1 (ALK1) or endoglin, increased inflammation and innate immune signaling. To understand the role of CNS resident macrophages in bAVM development and hemorrhage, we administrated a colony-stimulating factor 1 receptor inhibitor to bAVM mice with brain focal Alk1 deletion. Transient depletion of CNS resident macrophages at an early stage of bAVM development mitigated the phenotype severity of bAVM, including a prolonged inhibition of angiogenesis, dysplastic vasculature formation, and infiltration of CNS resident and circulating monocyte-derived macrophages during bAVM development. Transient depletion of CNS resident macrophages increased EC tight junction protein expression, reduced the number of dysplasia vessels and severe hemorrhage in established bAVMs. Thus, EC AVM causative gene mutation can activate CNS resident macrophages promoting bAVM progression. CNS resident macrophage could be a therapeutic target to mitigate the development and severity of bAVMs.
Subject(s)
Intracranial Arteriovenous Malformations , Macrophages , Monocytes , Neovascularization, Pathologic , Animals , Intracranial Arteriovenous Malformations/pathology , Intracranial Arteriovenous Malformations/metabolism , Intracranial Arteriovenous Malformations/genetics , Monocytes/metabolism , Macrophages/metabolism , Mice , Neovascularization, Pathologic/metabolism , Activin Receptors, Type II/metabolism , Activin Receptors, Type II/genetics , Humans , Endothelial Cells/metabolism , Endothelial Cells/pathology , Male , Mice, Knockout , Angiogenesis , EndoglinABSTRACT
Motor cortical circuit functions depend on the coordinated fine-tuning of two functionally diverse neuronal populations: glutamatergic pyramidal neurons providing synaptic excitation and GABAergic interneurons adjusting the response of pyramidal neurons through synaptic inhibition. Microglia are brain resident macrophages which dynamically refine cortical circuits by monitoring perineuronal extracellular matrix and remodelling synapses. Previously, we showed that colony-stimulating factor 1 receptor (CSF1R)-mediated myeloid cell depletion extended the lifespan, but impaired motor functions of MBP29 mice, a mouse model for multiple system atrophy. In order to better understand the mechanisms underlying these motor deficits we characterized the microglial involvement in the cortical balance of GABAergic interneurons and glutamatergic pyramidal neurons in 4-months-old MBP29 mice following CSF1R inhibition for 12 weeks. Lack of myeloid cells resulted in a decreased number of COUP TF1 interacting protein 2-positive (CTIP2+) layer V pyramidal neurons, however in a proportional increase of calretinin-positive GABAergic interneurons in MBP29 mice. While myeloid cell depletion did not alter the expression of important presynaptic and postsynaptic proteins, the loss of cortical perineuronal net area was attenuated by CSF1R inhibition in MBP29 mice. These cortical changes may restrict synaptic plasticity and potentially modify parvalbumin-positive perisomatic input. Collectively, this study suggests, that the lack of myeloid cells shifts the neuronal balance toward an increased inhibitory connectivity in the motor cortex of MBP29 mice thereby potentially deteriorating motor functions.
Subject(s)
Motor Cortex , Multiple System Atrophy , Mice , Animals , Neurons , Pyramidal Cells/physiology , Interneurons/physiology , Receptor Protein-Tyrosine Kinases , Myeloid CellsABSTRACT
Immunotherapy has achieved prominent clinical efficacy in combating cancer and has recently become a mainstream treatment strategy. However, achieving broad efficacy with a single modality is challenging, and the heterogeneity of the tumor microenvironment (TME) restricts the accuracy and effectiveness of immunotherapy strategies for tumors. Herein, a TME-responsive targeted nanoparticle to enhance antitumor immunity and reverse immune escape by codelivering interleukin-12 (IL-12) expressing gene and colony-stimulating factor-1 receptor (CSF-1R) inhibitor PLX3397 (PLX) is presented. The introduction of disulfide bonds and cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGD) peptides conferred reduction reactivity and tumor targeting to the nanoparticles, respectively. It is hypothesized that activating host immunity by the local expression of IL-12, while modulating the tumor-associated macrophages (TAM) function through blocking CSF-1/CSF-1R signaling, could constitute a feasible approach for cancer immunotherapy. The fabricated functional nanoparticle successfully ameliorated the TME by stimulating the proliferation and activation of T lymphocytes, promoting the repolarization of TAMs, reducing myeloid-derived suppressor cells (MDSCs), and promoting the maturation of dendritic cells (DC) as well as the secretion of antitumor cytokines, which efficiently suppressed tumor growth and metastasis. Finally, substantial changes in the TME were deciphered by single-cell analysis including infiltration of different cells, transcriptional states, secretory signaling and cell-cell communications. These findings provide a promising combinatorial immunotherapy strategy through immunomodulatory nanoparticles.
Subject(s)
Nanoparticles , Neoplasms , Humans , Tumor Microenvironment , Immunotherapy , Macrophages/metabolism , Neoplasms/drug therapy , Neoplasms/metabolism , Interleukin-12/metabolism , Nanoparticles/chemistry , Cell Line, TumorABSTRACT
Pexidartinib (PLX3397) is a small molecule receptor tyrosine kinase inhibitor of colony stimulating factor 1 receptor (CSF1R) with moderate selectivity over other members of the platelet derived growth factor receptor family. It is approved for treatment of tenosynovial giant cell tumors (TGCT). CSF1R is highly expressed by microglia, which are macrophages of the central nervous system (CNS) that defend the CNS against injury and pathogens and contribute to synapse development and plasticity. Challenged by pathogens, apoptotic cells, debris, or inflammatory molecules they adopt a responsive state to propagate the inflammation and eventually return to a homeostatic state. The phenotypic switch may fail, and disease-associated microglia contribute to the pathophysiology in neurodegenerative or neuropsychiatric diseases or long-lasting detrimental brain inflammation after brain, spinal cord or nerve injury or ischemia/hemorrhage. Microglia also contribute to the growth permissive tumor microenvironment of glioblastoma (GBM). In rodents, continuous treatment for 1-2 weeks via pexidartinib food pellets leads to a depletion of microglia and subsequent repopulation from the remaining fraction, which is aided by peripheral monocytes that search empty niches for engraftment. The putative therapeutic benefit of such microglia depletion or forced renewal has been assessed in almost any rodent model of CNS disease or injury or GBM with heterogeneous outcomes, but a tendency of partial beneficial effects. So far, microglia monitoring e.g. via positron emission imaging is not standard of care for patients receiving Pexidartinib (e.g. for TGCT), so that the depletion and repopulation efficiency in humans is still largely unknown. Considering the virtuous functions of microglia, continuous depletion is likely no therapeutic option but short-lasting transient partial depletion to stimulate microglia renewal or replace microglia in genetic disease in combination with e.g. stem cell transplantation or as part of a multimodal concept in treatment of glioblastoma appears feasible. The present review provides an overview of the preclinical evidence pro and contra microglia depletion as a therapeutic approach.
Subject(s)
Glioblastoma , Microglia , Humans , Aminopyridines/pharmacology , Pyrroles/metabolism , Pyrroles/pharmacology , Tumor MicroenvironmentABSTRACT
OBJECTIVE: This study analyzed how high glucose affects CSF1R and p-ERK1/2 expression in RF/6A cells. METHODS: The cells were cultured as high glucose (HG) and normal control (C) groups, and CSF1R shRNA was introduced. Real time PCR was used to detect the expression of CSF1R and p-ERK1/2 mRNA. Western blot was used to detect the expression of CSF1R and p-ERK1/2 proteins. Cell Counting Kit 8 (CCK-8) method was used to detect cell proliferation, while flow cytometry was used to detect apoptosis in HREC. RESULTS: Real-time PCR showed significantly raised CSF1R mRNA expression in HG. CSF1R inhibition lowered HG + LV shCSF1R CSF1R mRNA levels. Western blotting revealed higher CSF1R and p-ERK1/2 protein expression in HG than in C. Their expression level dropped after CSF1R inhibition. The number of tube-forming cells was higher in HG than in C, which reduced after CSF1R suppression. Inhibiting CSF1R also decreased cell proliferation and raised apoptosis. CONCLUSION: Overall, under high glucose, CSF1R and p-ERK1/2 were highly expressed, leading to reduced cellular activity, and CSF1R inhibition helped alleviate this effect.
Subject(s)
Apoptosis , Blotting, Western , Cell Proliferation , Glucose , MAP Kinase Signaling System , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor , Glucose/pharmacology , Cell Proliferation/drug effects , Apoptosis/drug effects , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors , MAP Kinase Signaling System/physiology , Real-Time Polymerase Chain Reaction , Mitogen-Activated Protein Kinase 1/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Flow Cytometry , Animals , Gene Expression Regulation , Cell Line , Microglia/metabolism , Microglia/drug effects , Rats , Signal Transduction , RNA, Small Interfering/geneticsABSTRACT
Graft-versus-host disease (GVHD) is a serious complication of otherwise curative allogeneic haematopoietic stem cell transplants. Chronic GVHD induces pathological changes in peripheral organs as well as the brain and is a frequent cause of late morbidity and death after bone-marrow transplantation. In the periphery, bone-marrow-derived macrophages are key drivers of pathology, but recent evidence suggests that these cells also infiltrate into cGVHD-affected brains. Microglia are also persistently activated in the cGVHD-affected brain. To understand the involvement of these myeloid cell populations in the development and/or progression of cGVHD pathology, we here utilized the blood-brain-barrier permeable colony stimulating factor-1 receptor (CSF-1R) inhibitor PLX3397 (pexidartinib) at varying doses to pharmacologically deplete both cell types. We demonstrate that PLX3397 treatment during the development of cGVHD (i.e., 30 days post-transplant) improves disease symptoms, reducing both the clinical scores and histopathology of multiple cGVHD target organs, including the sequestration of T cells in cGVHD-affected skin tissue. Cognitive impairments associated with cGVHD and neuroinflammation were also attenuated by PLX3397 treatment. PLX3397 treatment prior to the onset of cGVHD (i.e., immediately post-transplant) did not change in clinical scores or histopathology. Overall, our data demonstrate significant benefits of using PLX3397 for the treatment of cGVHD and associated organ pathologies in both the periphery and brain, highlighting the therapeutic potential of pexidartinib for this condition.
Subject(s)
Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Mice , Animals , Bone Marrow Transplantation , Graft vs Host Disease/drug therapy , Graft vs Host Disease/pathology , Receptor Protein-Tyrosine Kinases , Receptors, Colony-Stimulating Factor , Brain/pathology , Chronic DiseaseABSTRACT
BACKGROUND: This study aimed to find out the characteristics in relation to tumor recurrence in diffused-tenosynovial giant cell tumor of temporomandibular joint and to develop and validate the prognostic model for personalized prediction. METHODS: From April 2009 to January 2021, patients with diffused-tenosynovial giant cell tumor of temporomandibular joint at a single center were included in this study. The clinical features and local recurrence-free survival were assessed through the expression of the Ki-67 index and colony-stimulating factor 1 receptor expression. Both univariate and multivariate analyses were performed on the prognostic factors for local recurrence-free survival. An independent predictor nomogram and pertinent tumor characteristics were included. RESULTS: The retrospective study enrolling seventy eligible patients at the Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. During the follow-up time, eleven patients suffered tumor recurrence. Age was an independent risk factor for local recurrence-free survival (P = 0.032). The Ki-67 index varied significantly in different sites (P = 0.034) and tumor volume (P = 0.017). Multivariate logistic regression was used to develop the prediction model using both statistical significance and prognostic indicators. The C-index of the nomogram based on age, site, Ki-67, and colony-stimulating factor 1 receptor was 0.833. These variates provided good predicted accuracy for a nomogram on local recurrence-free survival. Diffused-tenosynovial giant cell tumor from the temporomandibular joint is extremely uncommon, and certain clinical traits are linked to the tumor proliferation index. CONCLUSIONS: We identified the risk indicators and developed a nomogram in this study to forecast the likelihood of local recurrence-free survival in patients with diffused-tenosynovial giant cell tumor from temporomandibular joint.
Subject(s)
Giant Cell Tumor of Tendon Sheath , Neoplasm Recurrence, Local , Humans , Retrospective Studies , Neoplasm Recurrence, Local/epidemiology , Neoplasm Recurrence, Local/pathology , Macrophage Colony-Stimulating Factor , Ki-67 Antigen , China , Giant Cell Tumor of Tendon Sheath/pathology , Temporomandibular Joint/pathologyABSTRACT
Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation and the destruction of bone and cartilage in affected joints. One of the unmet medical needs in the treatment of RA is to effectively prevent the structural destruction of joints, especially bone, which progresses because of resistance to conventional drugs that mainly have anti-inflammatory effects, and directly leads to a decline in the QOL of patients. We previously developed a novel and orally available type II kinase inhibitor of colony-stimulating factor-1 receptor (CSF1R), JTE-952. CSF1R is specifically expressed by monocytic-lineage cells, including bone-resorbing osteoclasts, and is important for promoting the differentiation and proliferation of osteoclasts. In the present study, we investigated the therapeutic effect of JTE-952 on methotrexate (MTX)-refractory joint destruction in a clinically established adjuvant-induced arthritis rat model. JTE-952 did not suppress paw swelling under inflammatory conditions, but it inhibited the destruction of joint structural components including bone and cartilage in the inflamed joints. In addition, decreased range of joint motion and mechanical hyperalgesia after disease onset were suppressed by JTE-952. These results suggest that JTE-952 is expected to prevent the progression of the structural destruction of joints and its associated effects on joint motion and pain by inhibiting CSF1/CSF1R signaling in RA pathology, which is resistant to conventional disease-modifying anti-rheumatic drugs such as MTX.
Subject(s)
Antineoplastic Agents , Arthritis, Rheumatoid , Animals , Rats , Methotrexate/pharmacology , Methotrexate/therapeutic use , Macrophage Colony-Stimulating Factor , Quality of Life , Arthritis, Rheumatoid/drug therapy , Receptor Protein-Tyrosine KinasesABSTRACT
Strategies to increase intratumoral concentrations of an anticancer agent are desirable to optimize its therapeutic potential when said agent is efficacious primarily within a tumor but also have significant systemic side effects. Here, we generate a bifunctional protein by fusing interleukin-10 (IL-10) to a colony-stimulating factor-1 receptor (CSF-1R)-blocking antibody. The fusion protein demonstrates significant antitumor activity in multiple cancer models, especially head and neck cancer. Moreover, this bifunctional protein not only leads to the anticipated reduction in tumor-associated macrophages but also triggers proliferation, activation, and metabolic reprogramming of CD8+ T cells. Furthermore, it extends the clonotype diversity of tumor-infiltrated T cells and shifts the tumor microenvironment (TME) to an immune-active state. This study suggests an efficient strategy for designing immunotherapeutic agents by fusing a potent immunostimulatory molecule to an antibody targeting TME-enriched factors.