RESUMO
Peripheral sensory neurons widely innervate various tissues to continuously monitor and respond to environmental stimuli. Whether peripheral sensory neurons innervate the spleen and modulate splenic immune response remains poorly defined. Here, we demonstrate that nociceptive sensory nerve fibers extensively innervate the spleen along blood vessels and reach B cell zones. The spleen-innervating nociceptors predominantly originate from left T8-T13 dorsal root ganglia (DRGs), promoting the splenic germinal center (GC) response and humoral immunity. Nociceptors can be activated by antigen-induced accumulation of splenic prostaglandin E2 (PGE2) and then release calcitonin gene-related peptide (CGRP), which further promotes the splenic GC response at the early stage. Mechanistically, CGRP directly acts on B cells through its receptor CALCRL-RAMP1 via the cyclic AMP (cAMP) signaling pathway. Activating nociceptors by ingesting capsaicin enhances the splenic GC response and anti-influenza immunity. Collectively, our study establishes a specific DRG-spleen sensory neural connection that promotes humoral immunity, suggesting a promising approach for improving host defense by targeting the nociceptive nervous system.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Centro Germinativo , Imunidade Humoral , Baço , Animais , Masculino , Camundongos , Linfócitos B/imunologia , Linfócitos B/metabolismo , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Capsaicina/farmacologia , AMP Cíclico/metabolismo , Dinoprostona/metabolismo , Gânglios Espinais/metabolismo , Centro Germinativo/imunologia , Camundongos Endogâmicos C57BL , Nociceptores/metabolismo , Proteína 1 Modificadora da Atividade de Receptores/metabolismo , Células Receptoras Sensoriais/metabolismo , Células Receptoras Sensoriais/efeitos dos fármacos , Transdução de Sinais , Baço/inervação , Baço/imunologia , FemininoRESUMO
The suprachiasmatic nucleus (SCN) drives circadian clock coherence through intercellular coupling, which is resistant to environmental perturbations. We report that primary cilia are required for intercellular coupling among SCN neurons to maintain the robustness of the internal clock in mice. Cilia in neuromedin S-producing (NMS) neurons exhibit pronounced circadian rhythmicity in abundance and length. Genetic ablation of ciliogenesis in NMS neurons enabled a rapid phase shift of the internal clock under jet-lag conditions. The circadian rhythms of individual neurons in cilia-deficient SCN slices lost their coherence after external perturbations. Rhythmic cilia changes drive oscillations of Sonic Hedgehog (Shh) signaling and clock gene expression. Inactivation of Shh signaling in NMS neurons phenocopied the effects of cilia ablation. Thus, cilia-Shh signaling in the SCN aids intercellular coupling.
Assuntos
Cílios , Relógios Circadianos , Ritmo Circadiano , Proteínas Hedgehog , Neurônios do Núcleo Supraquiasmático , Animais , Camundongos , Cílios/metabolismo , Cílios/fisiologia , Relógios Circadianos/genética , Ritmo Circadiano/fisiologia , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Neurônios do Núcleo Supraquiasmático/fisiologia , Transdução de Sinais , Regulação da Expressão Gênica , Camundongos TransgênicosRESUMO
Primary cilia transduce diverse signals in embryonic development and adult tissues. Defective ciliogenesis results in a series of human disorders collectively known as ciliopathies. The CP110-CEP97 complex removal from the mother centriole is an early critical step for ciliogenesis, but the underlying mechanism for this step remains largely obscure. Here, we reveal that the linear ubiquitin chain assembly complex (LUBAC) plays an essential role in ciliogenesis by targeting the CP110-CEP97 complex. LUBAC specifically generates linear ubiquitin chains on CP110, which is required for CP110 removal from the mother centriole in ciliogenesis. We further identify that a pre-mRNA splicing factor, PRPF8, at the distal end of the mother centriole acts as the receptor of the linear ubiquitin chains to facilitate CP110 removal at the initial stage of ciliogenesis. Thus, our study reveals a direct mechanism of regulating CP110 removal in ciliogenesis and implicates the E3 ligase LUBAC as a potential therapy target of cilia-associated diseases, including ciliopathies and cancers.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Centríolos/metabolismo , Cílios/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Organogênese , Fosfoproteínas/metabolismo , Ubiquitina/metabolismo , Animais , Linhagem Celular , Humanos , Camundongos , Complexos Multiproteicos , Proteínas de Ligação a RNA/metabolismo , Especificidade por Substrato , Ubiquitinação , Peixe-ZebraRESUMO
Dynamic assembly and disassembly of primary cilia controls embryonic development and tissue homeostasis. Dysregulation of ciliogenesis causes human developmental diseases termed ciliopathies. Cell-intrinsic regulatory mechanisms of cilia disassembly have been well-studied. The extracellular cues controlling cilia disassembly remain elusive, however. Here, we show that lysophosphatidic acid (LPA), a multifunctional bioactive phospholipid, acts as a physiological extracellular factor to initiate cilia disassembly and promote neurogenesis. Through systematic analysis of serum components, we identify a small molecular-LPA as the major driver of cilia disassembly. Genetic inactivation and pharmacological inhibition of LPA receptor 1 (LPAR1) abrogate cilia disassembly triggered by serum. The LPA-LPAR-G-protein pathway promotes the transcription and phosphorylation of cilia disassembly factors-Aurora A, through activating the transcription coactivators YAP/TAZ and calcium/CaM pathway, respectively. Deletion of Lpar1 in mice causes abnormally elongated cilia and decreased proliferation in neural progenitor cells, thereby resulting in defective neurogenesis. Collectively, our findings establish LPA as a physiological initiator of cilia disassembly and suggest targeting the metabolism of LPA and the LPA pathway as potential therapies for diseases with dysfunctional ciliogenesis.
Assuntos
Cílios/efeitos dos fármacos , Lisofosfolipídeos/farmacologia , Neurogênese/efeitos dos fármacos , Epitélio Pigmentado da Retina/efeitos dos fármacos , Transdução de Sinais , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Cílios/genética , Cílios/metabolismo , Células HEK293 , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Humanos , Lisofosfolipídeos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Ligação Proteica , Interferência de RNA , Receptores de Ácidos Lisofosfatídicos/genética , Receptores de Ácidos Lisofosfatídicos/metabolismo , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/metabolismoRESUMO
Primary cilia protrude from the cell surface and have diverse roles during development and disease, which depends on the precise timing and control of cilia assembly and disassembly. Inactivation of assembly often causes cilia defects and underlies ciliopathy, while diseases caused by dysfunction in disassembly remain largely unknown. Here, we demonstrate that CEP55 functions as a cilia disassembly regulator to participate in ciliopathy. Cep55-/- mice display clinical manifestations of Meckel-Gruber syndrome, including perinatal death, polycystic kidneys, and abnormalities in the CNS. Interestingly, Cep55-/- mice exhibit an abnormal elongation of cilia on these tissues. Mechanistically, CEP55 promotes cilia disassembly by interacting with and stabilizing Aurora A kinase, which is achieved through facilitating the chaperonin CCT complex to Aurora A. In addition, CEP55 mutation in Meckel-Gruber syndrome causes the failure of cilia disassembly. Thus, our study establishes a cilia disassembly role for CEP55 in vivo, coupling defects in cilia disassembly to ciliopathy and further suggesting that proper cilia dynamics are critical for mammalian development.
Assuntos
Aurora Quinase A/metabolismo , Proteínas de Ciclo Celular/metabolismo , Cílios/metabolismo , Animais , Pontos de Checagem do Ciclo Celular , Proteínas de Ciclo Celular/deficiência , Células Cultivadas , Centrossomo/metabolismo , Centrossomo/ultraestrutura , Chaperonina com TCP-1/metabolismo , Cílios/ultraestrutura , Transtornos da Motilidade Ciliar/patologia , Encefalocele/patologia , Estabilidade Enzimática , Marcação de Genes , Células HEK293 , Humanos , Camundongos , Mitose , Fenótipo , Doenças Renais Policísticas/patologia , Ligação Proteica , Retinose Pigmentar/patologia , Receptor Smoothened/metabolismoRESUMO
Faithful chromosome segregation requires proper chromosome congression at prometaphase and dynamic maintenance of the aligned chromosomes at metaphase. Chromosome missegregation can result in aneuploidy, birth defects and cancer. The kinetochore-bound KMN network and the kinesin motor CENP-E are critical for kinetochore-microtubule attachment and chromosome stability. The linear ubiquitin chain assembly complex (LUBAC) attaches linear ubiquitin chains to substrates, with well-established roles in immune response. Here, we identify LUBAC as a key player of chromosome alignment during mitosis. LUBAC catalyzes linear ubiquitination of the kinetochore motor CENP-E, which is specifically required for the localization of CENP-E at attached kinetochores, but not unattached ones. KNL1 acts as a receptor of linear ubiquitin chains to anchor CENP-E at attached kinetochores in prometaphase and metaphase. Thus, linear ubiquitination promotes chromosome congression and dynamic chromosome alignment by coupling the dynamic kinetochore microtubule receptor CENP-E to the static one, the KMN network.
Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Cinetocoros/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas Cromossômicas não Histona/genética , Segregação de Cromossomos , Fibroblastos , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/genética , Mitose , Cultura Primária de Células , RNA Interferente Pequeno/metabolismo , Ubiquitina-Proteína Ligases/genética , UbiquitinaçãoRESUMO
The primary cilium is a sensory organelle that protrudes from the cell surface. Primary cilia undergo dynamic transitions between assembly and disassembly to exert their function in cell signaling. In this study, we identify the small GTPase Rab7 as a novel regulator of cilia disassembly. Depletion of Rab7 potently induced spontaneous ciliogenesis in proliferating cells and promoted cilia elongation during quiescence. Moreover, Rab7 performs an essential role in cilia disassembly; knockdown of Rab7 blocked serum-induced ciliary resorption, and active Rab7 was required for this process. Further, we demonstrate that Rab7 depletion significantly suppresses cilia tip excision, referred to as cilia ectocytosis, which has been identified as required for cilia disassembly. Mechanically, the failure of F-actin polymerization at the site of excision of cilia tips caused suppression of cilia ectocytosis on Rab7 depletion. Overall, our results suggest a novel function for Rab7 in regulating cilia ectocytosis and cilia disassembly via control of intraciliary F-actin polymerization.
Assuntos
Citoesqueleto de Actina/metabolismo , Cílios/metabolismo , Transdução de Sinais , Proteínas rab de Ligação ao GTP/metabolismo , Actinas/metabolismo , Divisão Celular , Linhagem Celular , Proliferação de Células , GTP Fosfo-Hidrolases/metabolismo , Células HEK293 , Humanos , Proteínas Ligantes de Maltose/metabolismo , Polímeros/metabolismo , RNA Interferente Pequeno/metabolismo , proteínas de unión al GTP Rab7RESUMO
Defective ciliogenesis causes human developmental diseases termed ciliopathies. Microtubule (MT) asters originating from centrosomes in mitosis ensure the fidelity of cell division by positioning the spindle apparatus. However, the function of microtubule asters in interphase remains largely unknown. Here, we reveal an essential role of MT asters in transition zone (TZ) assembly during ciliogenesis. We demonstrate that the centrosome protein FSD1, whose biological function is largely unknown, anchors MT asters to interphase centrosomes by binding to microtubules. FSD1 knockdown causes defective ciliogenesis and affects embryonic development in vertebrates. We further show that disruption of MT aster anchorage by depleting FSD1 or other known anchoring proteins delocalizes the TZ assembly factor Cep290 from centriolar satellites, and causes TZ assembly defects. Thus, our study establishes FSD1 as a MT aster anchorage protein and reveals an important function of MT asters anchored by FSD1 in TZ assembly during ciliogenesis.