Recently, we reported that astrocytes in the trigeminal caudal nucleus (Vc) of the brain stem express a purinergic receptor P2X₃, which is involved in the craniofacial pathologic pain. Although we observed protein expression of P2X₃ receptors (P2X₃ Rs) in the astrocyte of the Vc, it is still unclear that astrocyte has functional P2X₃Rs in Vc. To address this issue, we recorded asrtocytic P2X₃Rs by using whole cell voltage-clamp recording in the Vc of the GFAP-GFP mice, which was used as a guide to astrocytes with green fluorescence. While measuring voltage ramp-induced astrocytic membrane current, we found the amplitude of the current was increased when we applied P2-purinoreceptor agonist, α,β-meATP. This increase was blocked by co-application of A317491, P2X₃R antagonist. These results demonstrate that astrocytes in the Vc express functional P2X₃Rs, which might be critical in craniofacial pathologic pain.
Animals ; Astrocytes ; Brain Stem ; Electrophysiology ; Fluorescence ; Membranes ; Mice* ; Trigeminal Caudal Nucleus*

The isoflavonol glycoside Talosin A, genistein (GT)-7-alpha-L-6-deoxy talopyranose (GT-Tal), was first isolated from the culture broth of Kitasatospora kifunensis MJM341. The aim of the present study was to evaluate the oral absorption and metabolism of the newly isolated isoflavonol glycoside, GT-Tal compared to genistin (GT-7-O-beta-D-glucopyranoside; GT-Glu). Free GT-Glu and GT-Tal could not be detected prior to enzymatic hydrolysis of the corresponding conjugates in rat plasma. Following oral administration of GT-Tal (15 min), GT-Tal was rapidly absorbed through the gastrointestinal tract and metabolized into GT-Tal conjugates with a mean Cmax of 2.74 microg/mL. GT-Tal was further metabolized to its aglycone, free GT and conjugated GT. After oral administration, GT-Glu was absorbed after being convereted to its aglycone and then further metabolized into its conjugate metabolites (free GT with a mean Cmax of 0.24 mg/mL at 1.25 h; conjugated GT with a mean Cmax of 1.31 mg/mL at 2.00 h). Significant differences in absorption and metabolism of GT-Tal and GT-Glu were observed. GT-Tal was metabolized into its corresponding conjugates or underwent deglycosylation to form GT, whereas GT-Glu was metabolized into its aglycone, GT.
Actinobacteria/*chemistry ; Administration, Oral ; Animals ; Area Under Curve ; Glycosides/administration & dosage/*metabolism/pharmacokinetics ; Hydrolysis ; Intestinal Absorption ; Isoflavones/administration & dosage/*metabolism/pharmacokinetics ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley

We investigated the role of the central MAPK pathways in extra-territorial (referred) pain resulting from inflammation of the temporomandibular joint (TMJ). Experiments were carried out on male Sprague-Dawley rats weighing 220-280 g. Under anesthesia, these animals were injected with 50 microL of complete Freund's adjuvant (CFA) into the TMJ using a Hamilton syringe. In the control group, saline was injected into the TMJ. To identify the extent of inflammation of the TMJ, Evans blue dye (0.1%, 5 mg/kg) was injected intravenously at 1, 3, 6, 9, 12 and 15 days after CFA injection. The concentration of Evans blue dye in the extracted TMJ tissue was found to be significantly higher in the CFA-treated animals than in the saline-treated group. Air-puff thresholds in the vibrissa pad area were evaluated 3 days before and at 3, 6, 9, 12, 15 and 18 days after CFA injection into the TMJ. Referred mechanical allodynia was established at 3 days, remained until 12 days, and recovered to preoperative levels at 18 days after CFA injection. This referred mechanical allodynia was observed in contralateral side area. To investigate the role of central MAPK pathways, MAPK inhibitors (10 microg) were administrated intracisternally 9 days after CFA injection. SB203580, a p38 MAPK inhibitor, significantly attenuated referred mechanical allodynia, as compared with the vehicle group. PD98059, a MEK inhibitor, also reduced CFA-induced referred mechanical allodynia. These results suggest that TMJ inflammation produces extra-territorial mechanical allodynia, and that this is mediated by central MAPK pathways.
Anesthesia ; Animals ; Evans Blue ; Flavonoids ; Freund's Adjuvant ; Humans ; Hyperalgesia ; Imidazoles ; Inflammation ; Male ; p38 Mitogen-Activated Protein Kinases ; Pain, Referred ; Pyridines ; Rats ; Rats, Sprague-Dawley ; Syringes ; Temporomandibular Joint

µ-opioid receptor (MOR) is a class of opioid receptors with a high affinity for enkephalins and beta-endorphin. In hippocampus, activation of MOR is known to enhance the neuronal excitability of pyramidal neurons, which has been mainly attributed to a disinhibition of pyramidal neurons via activating Gαi subunit to suppress the presynaptic release of GABA in hippocampal interneurons. In contrast, the potential role of MOR in hippocampal astrocytes, the most abundant cell type in the brain, has remained unexplored. Here, we determine the cellular and subcellular distribution of MOR in different cell types of the hippocampus by utilizing MOR-mCherry mice and two different antibodies against MOR. Consistent with previous findings, we demonstrate that MOR expression in the CA1 pyramidal layer is co-localized with axon terminals from GABAergic inhibitory neurons but not with soma of pyramidal neurons. More importantly, we demonstrate that MOR is highly expressed in CA1 hippocampal astrocytes. The ultrastructural analysis further demonstrates that the astrocytic MOR is localized in soma and processes, but not in microdomains near synapses. Lastly, we demonstrate that astrocytes in ventral tegmental area and nucleus accumbens also express MOR. Our results provide the unprecedented evidence for the presence of MOR in astrocytes, implicating potential roles of astrocytic MOR in addictive behaviors.
Animals ; Antibodies ; Astrocytes* ; Behavior, Addictive ; beta-Endorphin ; Brain ; Carisoprodol ; Enkephalins ; gamma-Aminobutyric Acid ; Hippocampus ; Interneurons ; Mice ; Microscopy, Electron ; Neurons ; Nucleus Accumbens ; Presynaptic Terminals ; Pyramidal Cells ; Receptors, Opioid ; Synapses ; Ventral Tegmental Area

Purpose: Although advancements in medical treatments have been made, approximately half of patients with intestinal Crohn’s disease (CD) require intestinal resections during their lifetime. It is well-known that the nutritional status of CD patients can impact postoperative morbidity. The objective of this study was to evaluate the clinical significance of prognostic nutritional index (PNI) in patients with intestinal CD who underwent primary bowel resection. Materials and Methods: We retrospectively investigated patients who were diagnosed with CD and underwent intestinal surgery at Severance Hospital between January 2005 and October 2018. The patients were divided into two groups: PNI ≤40 (n=150) and PNI >40 (n=77). We assessed the clinical significance of PNI in terms of the incidence of postoperative infectious complications (PICs) and the postoperative recurrence of CD. Results: The low PNI group had significantly higher rates of infectious complications (32.0% vs. 10.4%, p=0.001) compared to the high PNI group. Multivariable analysis identified low PNI (≤40) and longer operation time (>180 min) as independent risk factors associated with PICs [odds ratio (OR)=2.754, 95% confidence interval (CI)=1.140–6.649, p=0.024; OR=2.986, 95% CI=1.451–6.143, p=0.003]. PICs were significantly associated with surgical recurrence (hazard ratio=2.217, 95% CI=1.064–4.617, p=0.034). Conclusion Preoperative PNI could serve as a predictive factor for PICs in CD patients who undergo intestinal resection. Additionally, PICs are significantly associated with a higher risk of surgical recurrence in CD.