scholarly journals Sensory nerves directly promote osteoclastogenesis by secreting Cyp40

2021 ◽  
Author(s):  
Guo-Xian Pei ◽  
Liu Yang ◽  
Junqin Li ◽  
Bin Liu ◽  
Hao Wu ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Repair ◽  
Bone Cells ◽  
Critical Role ◽  
Sensory Nerve ◽  
Sensory Nerves ◽  
Blue Staining ◽  
Double Labeling ◽  
Sensory Hypersensitivity

Abstract BackgroundGiven the afferent functions, sensors have been found exerting efferent influences and directly alter organ physiology. Sensory nerves have been found critical in osteoclasts and bone resorption. However, the direct evidence of whether sensory nerve efferent influences osteoclast, remains lacking. MethodsWe treated mice with resiniferatoxin (RTX) or complete Freund’s adjuvant (CFA) to induce sensory hypersensitivity. Bone histomorphometry including micro-ct, three-point bending assay, von kossa staining, calcein double labeling, toluidine blue staining, and trap staining were performed to monitor bone quality and bone cells. Multiple virus vectors were applied to trace signals between sensory nerves and osteoclasts. Sensory neurons (SN) and osteoclasts were cocultured to study the effects and mechanisms of the sensory nerves on osteoclasts in vitro. Isobaric tag for relative and absolute quantitation (iTRAQ) was used to identify secreted proteins in the sensory nerve. ResultsHere, we found sensory hypersensitivity significantly increased osteoclast bone resorption; SN directly promote osteoclastogenesis in vitro; and abundant sensory efferent signals transported into osteoclasts. Then our screening identified a novel neuropeptide Peptidyl-prolyl cis-trans isomerase D (Cyp40), is the reverse signal from the sensory nerve and plays a critical role for osteoclastogenesis, via aryl hydrocarbon receptor (AhR)-Ras/Raf-pErk-NFATc1 pathway. The efferent signals from sensory nerves tend to involves in the rapid feedback process: vast majority of sensory efferent signals (87.28%) present in fast-twitch myofibers. ConclusionThis study revealed a novel mechanism of sensory nerves on osteoclasts: the direct promotion of osteoclastogenesis by the Cyp40. This mechanism may represent a direct, and quick response of sensory nerves to the changes in bone. Targeting the Cyp40 could therefore be a strategy to promote bone repair at the early stage of bone injury.

scholarly journals Myeloid-to-mesenchymal NGF-p75 signaling coordinates skeletal cell migration during repair

2021 ◽  
Author(s):  
Jiajia Xu ◽  
Zhao Li ◽  
Robert J. Tower ◽  
Stefano Negri ◽  
Yiyun Wang ◽  
...  
Keyword(s):  
Cancer Biology ◽  
Bone Repair ◽  
Sensory Nerve ◽  
Sensory Nerves ◽  
Cellular Migration ◽  
Conditional Deletion ◽  
Mesenchymal Precursor Cells ◽  
High Affinity Receptor ◽  
Affinity Receptor

Tissue repair relies on the coordination of mesenchymal precursor cells (MPCs) which migrate into the injury site, along with the invasion of blood vessels and sensory nerves. Our prior observations found that the neurotrophin Nerve growth factor (NGF) regulates sensory nerve ingrowth to skeletal repair sites via its high-affinity receptor. A body of work in cancer biology suggest that neurotrophins also engage their low-affinity receptor p75 to mediate cellular migration. Here, we observed conditional deletion of p75 in MPCs or osteoblasts to disrupt bone repair independent of neurovascular ingrowth. Single cell sequencing identified defects in migration and wound healing among MPC populations. Deletion of Ngf among myeloid cells phenocopied p75 conditional deletion animals. In vitro studies confirmed a myeloid-to-mesenchymal NGF-p75 axis which operates to induce cellular migration. Together, our data suggest a direct effect of myeloid-derived NGF on progenitor cells, in parallel to sensory nerve recruitment, required for injury repair.

scholarly journals P2Y12 receptor mediates microglial activation via RhoA/ROCK pathway in the trigeminal nucleus caudalis in a mouse model of chronic migraine

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Feng Jing ◽  
Yixin Zhang ◽  
Ting Long ◽  
Wei He ◽  
Guangcheng Qin ◽  
...  
Keyword(s):  
Chronic Migraine ◽  
Microglial Activation ◽  
Morphological Changes ◽  
Critical Role ◽  
Radiant Heat ◽  
P2y12 Receptor ◽  
Trigeminal Nucleus ◽  
Double Labeling ◽  
Trigeminal Nucleus Caudalis

Abstract Background Microglial activation contributes to the development of chronic migraine (CM). The P2Y12 receptor (P2Y12R), a metabolic purinoceptor that is expressed on microglia in the central nervous system (CNS), has been indicated to play a critical role in the pathogenesis of chronic pain. However, whether it contributes to the mechanism of CM remains unknown. Thus, the present study investigated the precise details of microglial P2Y12R involvement in CM. Methods Mice subjected to recurrent nitroglycerin (NTG) treatment were used as the CM model. Hyperalgesia were assessed by mechanical withdrawal threshold to electronic von Frey and thermal withdrawal latency to radiant heat. Western blot and immunohistochemical analyses were employed to detect the expression of P2Y12R, Iba-1, RhoA, and ROCK2 in the trigeminal nucleus caudalis (TNC). To confirm the role of P2Y12R and RhoA/ROCK in CM, we systemically administered P2Y12R antagonists (MRS2395 and clopidogrel) and a ROCK2 inhibitor (fasudil) and investigated their effects on microglial activation, c-fos, and calcitonin gene-related peptide (CGRP) expression in the TNC. To further confirm the effect of P2Y12R on microglial activation, we preincubated lipopolysaccharide (LPS)-treated BV-2 microglia with MRS2395 and clopidogrel. ELISA was used to evaluate the levels of inflammatory cytokines. Results The protein levels of P2Y12R, GTP-RhoA, ROCK2, CGRP, c-fos, and inducible nitric oxide synthase (iNOS) in the TNC were increased after recurrent NTG injection. A double labeling study showed that P2Y12R was restricted to microglia in the TNC. MRS2395 and clopidogrel attenuated the development of tactile allodynia and suppressed the expression of CGRP, c-fos, and GTP-RhoA/ROCK2 in the TNC. Furthermore, fasudil also prevented hyperalgesia and suppressed the expression of CGRP in the TNC. In addition, inhibiting P2Y12R and ROCK2 activities suppressed NTG-induced microglial morphological changes (process retraction) and iNOS production in the TNC. In vitro, a double labeling study showed that P2Y12R was colocalized with BV-2 cells, and the levels of iNOS, IL-1β, and TNF-α in LPS-stimulated BV-2 microglia were reduced by P2Y12R inhibitors. Conclusions These data demonstrate that microglial P2Y12R in the TNC plays a critical role in the pathogenesis of CM by regulating microglial activation in the TNC via RhoA/ROCK pathway.

Capsaicin-sensitive afferent nerves activate submucosal secretomotor neurons in guinea pig ileum

1995 ◽  
Vol 269 (2) ◽  
pp. G203-G209 ◽  
Author(s):  
S. Vanner ◽  
W. K. MacNaughton
Keyword(s):  
Guinea Pig ◽  
Ion Transport ◽  
Short Circuit ◽  
Ussing Chamber ◽  
Sensory Nerve ◽  
Nerve Fibers ◽  
Sensory Nerves ◽  
Guinea Pig Ileum ◽  
Secretomotor Neurons

This study examined whether capsaicin-sensitive sensory nerves regulate intestinal ion transport using both Ussing chamber and intracellular recording techniques in in vitro submucosal preparations from the guinea pig ileum. In Ussing chamber studies, serosal application of capsaicin (20 nM-20 microM) evoked a biphasic dose-dependent increase in short-circuit current (Isc) (maximal effective concentration 200 nM and 2 microM, respectively). In chloride-free buffer, capsaicin responses were significantly reduced. Capsaicin evoked little or no response when extrinsic sensory nerve fibers had been surgically removed and tetrodotoxin and low-calcium and high-magnesium solutions blocked responses to capsaicin. In epithelial preparations devoid of submucosal neurons, capsaicin had virtually no effect, suggesting that responses evoked by capsaicin-sensitive nerves result from activation of submucosal secretomotor neurons. Intracellular recordings from single submucosal neurons demonstrated that superfusion with capsaicin (2 microM) depolarized neurons with an associated decreased conductance. Depolarizations were completely desensitized when capsaicin was reapplied, but synaptic inputs were unaffected. This study suggests that capsaicin-sensitive nerves can regulate ion transport in the gastrointestinal tract by release of neurotransmitter(s) that activate submucosal secretomotor neurons.

Effects of ALK1Fc treatment on prostate cancer cells interacting with bone and bone cells in bone metastasis models.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e16576-e16576
Author(s):  
Marianna Kruithof-de Julio ◽  
Letizia Astrologo ◽  
Eugenio Zoni ◽  
Sofia Karkampouna ◽  
Peter C Gray ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Bone Metastasis ◽  
Cancer Cells ◽  
Bone Cells ◽  
Critical Role ◽  
Prostate Cancer Cells ◽  
Primary Prostate Cancer ◽  
The Impact

e16576 Background: Prostate cancer is the second most common cancer in men worldwide. Lethality is normally associated with the consequences of metastasis rather than the primary tumor. In particular, bone is the most frequent site of metastasis and once prostate tumor cells are engrafted in the skeleton, curative therapy is no longer possible. Bone morphogenetic proteins (BMPs) play a critical role in bone physiology and pathology. However, little is known about the role of BMP9 and its signaling receptors, ALK1 and ALK2, in prostate cancer and bone metastasis. In this context, we investigate the impact of BMP9 on primary prostate cancer and derived bone metastasis. Methods: The human ALK1 extracellular domain (ECD) binds BMP9 and BMP10 with high affinity. In order to study the effect of BMP9 in vitro and in vivo we use a soluble chimeric protein, consisting of ALK1 ECD fused to human Fc (ALK1Fc), for preventing the activation of endogenous signaling. ALK1Fc sequesters BMP9 and BMP10, preserving the activation of ALK1 through other ligands. Results: We show that ALK1Fc reduces BMP9-mediated signaling and decreases proliferation of highly metastatic and tumor initiating human prostate cancer cells in vitro. In line with these observations, we demonstrate that ALK1Fc reduces tumor growth in vivo in an orthotopic transplantation model. The propensity of the primary prostate cancer to metastasize to the bone is also investigated. In particular, we report how the ALK1Fc influences the prostate cancer cells in vitro and in vivo when these are probed in different bone settings (co-culture with bone cells and intraosseous transplantation in mice). Conclusions: Our study provides the first demonstration that ALK1Fc inhibits prostate cancer cells growth identifying BMP9 as a putative therapeutic target and ALK1Fc as a potential therapy. All together, these findings justify the ongoing clinical development of drugs blocking ALK1 and ALK2 receptor activity.

scholarly journals Canonical Wnt signaling inhibits osteoclastogenesis independent of osteoprotegerin

2013 ◽  
Vol 200 (4) ◽  
pp. 537-549 ◽  
Author(s):  
Joachim Albers ◽  
Johannes Keller ◽  
Anke Baranowsky ◽  
Frank Timo Beil ◽  
Philip Catala-Lehnen ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Wnt Signaling ◽  
Bone Cells ◽  
Osteoclast Differentiation ◽  
Negative Influence ◽  
Canonical Wnt Signaling ◽  
Mouse Tissues ◽  
Canonical Wnt

Although Wnt signaling is considered a key regulatory pathway for bone formation, inactivation of β-catenin in osteoblasts does not affect their activity but rather causes increased osteoclastogenesis due to insufficient production of osteoprotegerin (Opg). By monitoring the expression pattern of all known genes encoding Wnt receptors in mouse tissues and bone cells we identified Frizzled 8 (Fzd8) as a candidate regulator of bone remodeling. Fzd8-deficient mice displayed osteopenia with normal bone formation and increased osteoclastogenesis, but this phenotype was not associated with impaired Wnt signaling or Opg production by osteoblasts. The deduced direct negative influence of canonical Wnt signaling on osteoclastogenesis was confirmed in vitro and through the generation of mice lacking β-catenin in the osteoclast lineage. Here, we observed increased bone resorption despite normal Opg production and a resistance to the anti-osteoclastogenic effect of Wnt3a. These results demonstrate that Fzd8 and β-catenin negatively regulate osteoclast differentiation independent of osteoblasts and that canonical Wnt signaling controls bone resorption by two different mechanisms.

Localisation of mRNA for collagenase in osteocytic, bone surface and chondrocytic cells but not osteoclasts

1995 ◽  
Vol 108 (6) ◽  
pp. 2221-2230
Author(s):  
K. Fuller ◽  
T.J. Chambers
Keyword(s):  
Bone Resorption ◽  
Bone Cells ◽  
In Situ Hybridisation ◽  
Cysteine Proteinases ◽  
Bone Surface ◽  
Matrix Metalloproteinase 1 ◽  
Osteoclastic Resorption ◽  
Stimulation Of

Osteoclasts resorb the extracellular matrix of bone by secreting protons and enzymes into a circumpherentially sealed compartment between the osteoclast and the bone surface. Although the lysosomal cysteine proteinases play a major role in matrix degradation by osteoclasts, collagenase (matrix metalloproteinase-1, EC 3.4.24.7) is also required for osteoclastic bone resorption, and may be directly involved in collagen degradation in the hemivacuole. We assessed the effects of inhibitors of cysteine proteinases and collagenase on bone resorption by osteoclasts isolated from rodent bone. We found that while inhibition of cysteine proteinases strongly suppressed osteoclastic resorption, inhibitors of collagenase were without effect on the number, size, or demineralised fringe of excavations. We could find no evidence of expression of mRNA for collagenase in rat osteoclasts by in situ hybridisation, but found that it was expressed by chondrocytes, bone surface cells and osteocytes adjacent to osteoclasts. The distribution of these cells, and the correlation between increased collagenase production and increased stimulation of osteoclastic resorption in vitro by bone cells, suggests that these cells might be involved in the regulation of bone resorption in situ, and that collagenase production might play a role in this process.

Spatial transcriptomics reveals a role for sensory nerves in preserving cranial suture patency through modulation of BMP/TGF-β signaling

2021 ◽  
Vol 118 (42) ◽  
pp. e2103087118
Author(s):  
Robert J. Tower ◽  
Zhu Li ◽  
Yu-Hao Cheng ◽  
Xue-Wei Wang ◽  
Labchan Rajbhandari ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Sensory Nerve ◽  
Positive Association ◽  
Sensory Nerves ◽  
Cranial Bone ◽  
Morphogenetic Protein ◽  
Proliferation And Differentiation ◽  
Microfluidic Chambers

The patterning and ossification of the mammalian skeleton requires the coordinated actions of both intrinsic bone morphogens and extrinsic neurovascular signals, which function in a temporal and spatial fashion to control mesenchymal progenitor cell (MPC) fate. Here, we show the genetic inhibition of tropomyosin receptor kinase A (TrkA) sensory nerve innervation of the developing cranium results in premature calvarial suture closure, associated with a decrease in suture MPC proliferation and increased mineralization. In vitro, axons from peripheral afferent neurons derived from dorsal root ganglions (DRGs) of wild-type mice induce MPC proliferation in a spatially restricted manner via a soluble factor when cocultured in microfluidic chambers. Comparative spatial transcriptomic analysis of the cranial sutures in vivo confirmed a positive association between sensory axons and proliferative MPCs. SpatialTime analysis across the developing suture revealed regional-specific alterations in bone morphogenetic protein (BMP) and TGF-β signaling pathway transcripts in response to TrkA inhibition. RNA sequencing of DRG cell bodies, following direct, axonal coculture with MPCs, confirmed the alterations in BMP/TGF-β signaling pathway transcripts. Among these, the BMP inhibitor follistatin-like 1 (FSTL1) replicated key features of the neural-to-bone influence, including mitogenic and anti-osteogenic effects via the inhibition of BMP/TGF-β signaling. Taken together, our results demonstrate that sensory nerve-derived signals, including FSTL1, function to coordinate cranial bone patterning by regulating MPC proliferation and differentiation in the suture mesenchyme.

scholarly journals Osteoclasts express high levels of pp60c-src in association with intracellular membranes.

1992 ◽  
Vol 119 (4) ◽  
pp. 1003-1013 ◽  
Author(s):  
W C Horne ◽  
L Neff ◽  
D Chatterjee ◽  
A Lomri ◽  
J B Levy ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Cells ◽  
Bone Marrow Cells ◽  
Critical Role ◽  
Membrane Vesicles ◽  
Skeletal Defect ◽  
Src Gene ◽  
Intracellular Organelles ◽  
Related Proteins

Deletion of the c-src gene in transgenic mice by homologous recombination leads to osteopetrosis, a skeletal defect characterized by markedly deficient bone resorption (Soriano, P., C. Montgomery, R. Geske, and A. Bradley. 1991. Cell. 64:693-702), demonstrating a critical functional role of pp60c-src in osteoclast activity. Since decreased bone resorption could result from a defect either within the osteoclast or within other cells present in its environment, indirectly affecting osteoclast functions, we determined which cell(s) in bone expressed high levels of pp60c-src Measuring pp60c-src protein and kinase activities in osteoclasts and immunolocalizing pp60c-src in bone, we find that expression of pp60c-src is nearly as high in osteoclasts as in brain and platelets. In contrast, other bone cells contain only very low levels of the protein. In addition, expression of the c-src gene product increases when bone marrow cells are induced to express an osteoclast-like phenotype by 1,25-dihydroxy-vitamin D3, further suggesting that high expression of pp60c-src is part of the osteoclast phenotype. Three other src-like kinases, c-fyn, c-yes, and c-lyn, are also expressed in osteoclasts at ratios to pp60c-src similar to what is found in platelets. These src-related proteins do not, however, compensate for the absence of pp60c-src in the src- mice, thereby suggesting that pp60c-src may have a specific function in osteoclasts. Although further work is necessary to elucidate what the critical role of pp60c-src in osteoclasts is, our observation that the protein is associated mostly with the membranes of intracellular organelles suggests the possibility that this role might be at least in part related to the targeting or fusion of membrane vesicles.

scholarly journals In Vivo Analysis of Proprioceptive Coding and Its Antidromic Modulation in the Freely Behaving Crayfish

2005 ◽  
Vol 94 (2) ◽  
pp. 1013-1027 ◽  
Author(s):  
Didier Le Ray ◽  
Denis Combes ◽  
Cyril Déjean ◽  
Daniel Cattaert
Keyword(s):  
Motor Activity ◽  
Action Potentials ◽  
Physiological State ◽  
Sensory Nerve ◽  
Sensory Nerves ◽  
Chordotonal Organ ◽  
Electromyographic Activity ◽  
Sensory Coding ◽  
Freely Behaving

Although sensory nerves in vitro are known to convey both orthodromic (sensory) and antidromic (putatively modulating) action potentials, in most cases very little is known about their bidirectional characteristics in intact animals. Here, we have investigated both the sensory coding properties and antidromic discharges that occur during real walking in the freely behaving crayfish. The activity of the sensory nerve innervating the proprioceptor CBCO, a chordotonal organ that monitors both angular movement and position of the coxo-basipodite (CB) joint, which is implicated in vertical leg movements, was recorded chronically along with the electromyographic activity of the muscles that control CB joint movements. Two wire electrodes placed on the sensory nerve were used to discriminate orthodromic from antidromic action potentials and thus allowed for analysis of both sensory coding and antidromic discharges. A distinction is proposed between 3 main classes of sensory neuron, according to their firing in relation to levator muscle activity during free walking. In parallel, we describe 2 types of antidromic activity: one produced exclusively during motor activity and a second produced both during and in the absence of motor activity. A negative correlation was found between the activity of sensory neurons in each of the 3 classes and identified antidromic discharges during walking. Finally, a state-dependent plasticity of CBCO nerve activity has been found by which the distribution of sensory orthodromic and antidromic activity changes with the physiological state of the biomechanical apparatus.

scholarly journals Psoralen and Bakuchiol Ameliorate M-CSF Plus RANKL-Induced Osteoclast Differentiation and Bone Resorption Via Inhibition of AKT and AP-1 Pathways in Vitro

2018 ◽  
Vol 48 (5) ◽  
pp. 2123-2133 ◽  
Author(s):  
Lijuan Chai ◽  
Kun Zhou ◽  
Shaoxia Wang ◽  
Han Zhang ◽  
Na Fan ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Bone Resorption ◽  
Nuclear Translocation ◽  
Osteoclast Differentiation ◽  
Gelatin Zymography ◽  
Blue Staining ◽  
Tartrate Resistant Acid Phosphatase ◽  
Phosphorylated Akt ◽  
Primary Mouse

Background/Aims: Psoralen and bakuchiol are the main active compounds found in the traditional Chinese medicine Psoralea corylifolia L., and have been used to treat osteoporosis. This study aims to investigate the anti-osteoporosis effects of these two compounds using osteoclasts precursor differentiation and bone absorption assays in vitro. Methods: Primary mouse osteoclasts precursor cells were induced by M-CSF (macrophage colony stimulating factor) plus RANKL (receptor activator of nuclear factor kappa-B ligand) in vitro. TRACP (tartrate-resistant acid phosphatase) enzyme activity and toluidine blue staining were used to observe the effects of psoralen and bakuchiol on osteoclast differentiation and bone resorption, respectively. Gelatin zymography was used to assess MMP (matrix metalloproteinase) activity, and ELISA was performed to measure cathepsin K activity. Western blotting analysis for expression of phosphorylated AKT, ERK, NF-kB, and c-jun; and immunofluorescence analysis for c-jun and p65 nuclear translocation in induced osteoclasts were then used to determine the mechanism of anti-bone resorption of psoralen and bakuchiol. Results: Mature osteoclasts were induced by M-CSF plus RANKL from primary bone marrow macrophages in vitro. Both psoralen and bakuchiol significantly inhibited TRACP enzyme activity and slightly decreased the number of TRACP+ multinuclear osteoclasts induced by M-CSF plus RANKL. Bakuchiol significantly decreased bone lacunae area and attenuated MMP-2 activity induced by M-CSF plus RANKL in osteoclasts. Both psoralen and bakuchiol significantly decreased the expression and nuclear translocation of phosphorylated c-jun stimulated by M-CSF plus RANKL, but no significant effect on p65 translocation was observed in osteoclasts. Additionally, bakuchiol significantly attenuated the increased of M-CSF plus RANKL-induced phosphorylation of AKT in osteoclasts. Conclusions: Psoralen and bakuchiol ameliorated M-CSF plus RANKL-induced osteoclast differentiation and bone resorption via inhibition of AKT and AP-1 pathways activation in vitro.

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