Intracellular cAMP signaling-induced Ca influx mediated by calcium homeostasis modulator 1 (CALHM1) in human odontoblasts.

In odontoblasts, intracellular Ca signaling plays key roles in reactionary dentin formation and generation of dentinal pain. Odontoblasts also express several G protein-coupled receptors that promote production of cyclic AMP (cAMP). However, the crosstalk between intracellular cAMP and Ca signaling, as well as the role of cAMP in the cellular functions of odontoblasts, remains unclear.

Effect of Dental Local Anesthetics on Reactive Oxygen Species: An In Vitro Study.

Introduction Oxidative stress, an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, plays an important role in various dental diseases. Local anesthetics are frequently used in dentistry. The potential antioxidant activity of dental local anesthetics can contribute to dental practice.

Upregulation of in the salivary glands of mice exposed to a lunar gravity environment using the multiple artificial gravity research system.

Space is a unique environment characterized by isolation from community life and exposure to circadian misalignment, microgravity, and space radiation. These multiple differences from those experienced on the earth may cause systemic and local tissue stress. Autonomic nerves, including sympathetic and parasympathetic nerves, regulate functions in multiple organs.

Comparison of Lidocaine and Mepivacaine for Variation in Regional Tissue Oxygenation in Stellate Ganglion Block: A Randomized, Double-Blind, Crossover Trial.

Introduction This prospective, randomized, double-blind, crossover trial aimed to investigate the effect of different types of local anesthetics on regional tissue blood oxygenation on the stellate ganglion block (SGB). Methods Twenty eligible patients were recruited for this study; 16 of whom were allocated to the study protocol. Participants were randomized into one of the two crossover sequences: 1% lidocaine hydrochloride or 1% mepivacaine hydrochloride, and received SGBs with 6 mL of any one of the local anesthetics, followed by a washout period of more than 24 hours, and then received SGBs by substituting the two local anesthetics.

Intracellular cAMP Signaling Pathway via G Protein-Coupled Receptor Activation in Rat Primary Cultured Trigeminal Ganglion Cells.

G protein-coupled receptors in trigeminal ganglion (TG) neurons are often associated with sensory mechanisms, including nociception. We have previously reported the expression of P2Y receptors, which are G protein-coupled receptors, in TG cells. Activating P2Y receptors decreased the intracellular free Ca concentration ([Ca]).

Functional Expression of IP, 5-HT, D, A, and VIP Receptors in Human Odontoblast Cell Line.

Odontoblasts are involved in sensory generation as sensory receptor cells and in dentin formation. We previously reported that an increase in intracellular cAMP levels by cannabinoid 1 receptor activation induces Ca influx via transient receptor potential vanilloid subfamily member 1 channels in odontoblasts, indicating that intracellular cAMP/Ca signal coupling is involved in dentinal pain generation and reactionary dentin formation. Here, intracellular cAMP dynamics in cultured human odontoblasts were investigated to understand the detailed expression patterns of the intracellular cAMP signaling pathway activated by the G protein-coupled receptor and to clarify its role in cellular functions.

Functional Expression of Mechanosensitive Piezo1/TRPV4 Channels in Mouse Osteoblasts.

Mechanical stress is an important regulatory factor in bone homeostasis. Mechanical stimulation of osteoblasts has been shown to elicit an increase in the concentration of intracellular free Ca ([Ca]). The pattern of functional expression of mechanosensitive ion channels remains unclear, however.

Piezo1-pannexin-1-P2X axis in odontoblasts and neurons mediates sensory transduction in dentinal sensitivity.

According to the "hydrodynamic theory," dentinal pain or sensitivity is caused by dentinal fluid movement following the application of various stimuli to the dentin surface. Recent convergent evidence has shown that plasma membrane deformation, mimicking dentinal fluid movement, activates mechanosensitive transient receptor potential (TRP)/Piezo channels in odontoblasts, with the Ca signal eliciting the release of ATP from pannexin-1 (PANX-1). The released ATP activates the P2X receptor, which generates and propagates action potentials in the intradental Aδ afferent neurons.

Gα-Coupled CGRP Receptor Signaling Axis from the Trigeminal Ganglion Neuron to Odontoblast Negatively Regulates Dentin Mineralization.

An inflammatory response following dental pulp injury and/or infection often leads to neurogenic inflammation via the axon reflex. However, the detailed mechanism underlying the occurrence of the axon reflex in the dental pulp remains unclear. We sought to examine the intracellular cyclic adenosine monophosphate (cAMP) signaling pathway in odontoblasts via the activation of G protein-coupled receptors and intercellular trigeminal ganglion (TG) neuron-odontoblast communication following direct mechanical stimulation of TG neurons.

Direct Mechanical Stimulation Mediates Cell-to-Cell Interactions in Cultured Trigeminal Ganglion Cells.

Trigeminal neuralgia occurs in the orofacial region, characteristically causing pain that feels like a transient electric shock. Some histopathological studies have reported that trigeminal neuralgia is caused by mechanical compression of the demyelinated trigeminal nerve; the pathophysiological mechanism behind this phenomenon remains to be clarified, however. Cell-cell interactions have also been reported to be involved in the development and modulation of some types of neuropathic pain.

Mechanical Stimulation-Induced Calcium Signaling by Piezo1 Channel Activation in Human Odontoblast Reduces Dentin Mineralization.

Odontoblasts play critical roles in dentin formation and sensory transduction following stimuli on the dentin surface. Exogenous stimuli to the dentin surface elicit dentinal sensitivity through the movement of fluids in dentinal tubules, resulting in cellular deformation. Recently, Piezo1 channels have been implicated in mechanosensitive processes, as well as Ca signals in odontoblasts.

Plasma Membrane Ca-ATPase in Rat and Human Odontoblasts Mediates Dentin Mineralization.

Intracellular Ca signaling engendered by Ca influx and mobilization in odontoblasts is critical for dentinogenesis induced by multiple stimuli at the dentin surface. Increased Ca is exported by the Na-Ca exchanger (NCX) and plasma membrane Ca-ATPase (PMCA) to maintain Ca homeostasis. We previously demonstrated a functional coupling between Ca extrusion by NCX and its influx through transient receptor potential channels in odontoblasts.

Functional Coupling between the P2X Receptor and Pannexin-1 Channel in Rat Trigeminal Ganglion Neurons.

The ionotropic P2X receptor, P2X, is believed to regulate and/or generate nociceptive pain, and pain in several neuropathological diseases. Although there is a known relationship between P2X receptor activity and pain sensing, its detailed functional properties in trigeminal ganglion (TG) neurons remains unclear. We examined the electrophysiological and pharmacological characteristics of the P2X receptor and its functional coupling with other P2X receptors and pannexin-1 (PANX1) channels in primary cultured rat TG neurons, using whole-cell patch-clamp recordings.

Large-Conductance Calcium-Activated Potassium Channels and Voltage-Dependent Sodium Channels in Human Cementoblasts.

Cementum, which is excreted by cementoblasts, provides an attachment site for collagen fibers that connect to the alveolar bone and fix the teeth into the alveolar sockets. Transmembrane ionic signaling, associated with ionic transporters, regulate various physiological processes in a wide variety of cells. However, the properties of the signals generated by plasma membrane ionic channels in cementoblasts have not yet been described in detail.

Highly Efficient Conversion of Motor Neuron-Like NSC-34 Cells into Functional Motor Neurons by Prostaglandin E.

Motor neuron diseases are a group of progressive neurological disorders that degenerate motor neurons. The neuroblastoma × spinal cord hybrid cell line NSC-34 is widely used as an experimental model in studies of motor neuron diseases. However, the differentiation efficiency of NSC-34 cells to neurons is not always sufficient.

All-trans retinoic acid induces reprogramming of canine dedifferentiated cells into neuron-like cells.

The specification of cell identity depends on the exposure of cells to sequences of bioactive ligands. All-trans retinoic acid (ATRA) affects neuronal development in the early stage, and it is involved in neuronal lineage reprogramming. We previously established a fibroblast-like dedifferentiated fat cells (DFATs) derived from highly homogeneous mature adipocytes, which are more suitable for the study of cellular reprogramming.

Developmental studies on the acquisition of perception conducting pathways via TRP channels in rat molar odontoblasts using immunohistochemistry and RT-qPCR.

Odontoblasts act as dentin formation and sensory receptors. Recently, it was reported that transient receptor potential ankyrin (TRPA) 1, TRP vanilloid (TRPV) 4 and pannexin 1 (PANX-1) play important roles in odontoblast sensory reception. However, it is not known when odontoblasts begin to possess a sense reception function.

Light conditions affect rhythmic expression of aquaporin 5 and anoctamin 1 in rat submandibular glands.

Circadian rhythms regulate various physiological functions and are, therefore, essential for health. Light helps regulate the master and peripheral clocks. The secretion rates of saliva and electrolytes follow a circadian rhythm as well.

Merkel Cells Release Glutamate Following Mechanical Stimulation: Implication of Glutamate in the Merkel Cell-Neurite Complex.

Merkel cells (MCs) have been proposed to form a part of the MC-neurite complex with sensory neurons through synaptic contact. However, the detailed mechanisms for intercellular communication between MCs and neurons have yet to be clarified. The present study examined the increases in intracellular free Ca concentration ([Ca]) induced by direct mechanical stimulation of MCs.

Intracellular Ca mobilization pathway via bradykinin B receptor activation in rat trigeminal ganglion neurons.

Bradykinin (BK) and its receptors, B and B, in trigeminal ganglion (TG) neurons are involved in the regulation of pain. Recent studies have revealed that B receptors are expressed in neonatal rat TG neurons; however, the intracellular signaling pathway following B receptor activation remains to be elucidated. To investigate the mechanism by which B receptor activation leads to intracellular Ca mobilization, we measured the intracellular free Ca concentration ([Ca]) in primary-cultured TG neurons.

High pH-Sensitive Store-Operated Ca Entry Mediated by Ca Release-Activated Ca Channels in Rat Odontoblasts.

Odontoblasts play a crucial role in dentin formation and sensory transduction following the application of stimuli to the dentin surface. Various exogenous and endogenous stimuli elicit an increase in the intracellular free calcium concentration ([Ca]) in odontoblasts, which is mediated by Ca release from intracellular Ca stores and/or Ca influx from the extracellular medium. In a previous study, we demonstrated that the depletion of Ca stores in odontoblasts activated store-operated Ca entry (SOCE), a Ca influx pathway.

Activation of Mechanosensitive Transient Receptor Potential/Piezo Channels in Odontoblasts Generates Action Potentials in Cocultured Isolectin B-negative Medium-sized Trigeminal Ganglion Neurons.

Introduction: Various stimuli to the dentin surface elicit dentinal pain by inducing dentinal fluid movement causing cellular deformation in odontoblasts. Although odontoblasts detect deformation by the activation of mechanosensitive ionic channels, it is still unclear whether odontoblasts are capable of establishing neurotransmission with myelinated A delta (Aδ) neurons. Additionally, it is still unclear whether these neurons evoke action potentials by neurotransmitters from odontoblasts to mediate sensory transduction in dentin.

Potassium Currents Activated by Depolarization in Odontoblasts.

Increased intracellular free Ca concentrations elicit plasma membrane depolarization, which leads to the activation of K currents. However, the precise properties of K currents activated by depolarization in odontoblasts remain to be elucidated. The present study identified biophysical and pharmacological characteristics of time-dependent and voltage-activated K currents in freshly dissociated rat odontoblasts using patch-clamp recordings in a whole-cell configuration.