Odontoblasts as sensory receptors: transient receptor potential channels, pannexin-1, and ionotropic ATP receptors mediate intercellular odontoblast-neuron signal transduction.

Various stimuli induce pain when applied to the surface of exposed dentin. However, the mechanisms underlying dentinal pain remain unclear. We investigated intercellular signal transduction between odontoblasts and trigeminal ganglion (TG) neurons following direct mechanical stimulation of odontoblasts. Mechanical stimulation of single odontoblasts increased the intracellular free calcium concentration ([Ca(2+)]i) by activating the mechanosensitive-transient receptor potential (TRP) channels TRPV1, TRPV2, TRPV4, and TRPA1, but not TRPM8 channels. In cocultures of odontoblasts and TG neurons, increases in [Ca(2+)]i were observed not only in mechanically stimulated odontoblasts, but also in neighboring odontoblasts and TG neurons. These increases in [Ca(2+)]i were abolished in the absence of extracellular Ca(2+) and in the presence of mechanosensitive TRP channel antagonists. A pannexin-1 (ATP-permeable channel) inhibitor and ATP-degrading enzyme abolished the increases in [Ca(2+)]i in neighboring odontoblasts and TG neurons, but not in the stimulated odontoblasts. G-protein-coupled P2Y nucleotide receptor antagonists also inhibited the increases in [Ca(2+)]i. An ionotropic ATP (P2X3) receptor antagonist inhibited the increase in [Ca(2+)]i in neighboring TG neurons, but not in stimulated or neighboring odontoblasts. During mechanical stimulation of single odontoblasts, a connexin-43 blocker did not have any effects on the [Ca(2+)]i responses observed in any of the cells. These results indicate that ATP, released from mechanically stimulated odontoblasts via pannexin-1 in response to TRP channel activation, transmits a signal to P2X3 receptors on TG neurons. We suggest that odontoblasts are sensory receptor cells and that ATP released from odontoblasts functions as a neurotransmitter in the sensory transduction sequence for dentinal pain.

Predictive Models for Palliative Care Needs of Advanced Cancer Patients Receiving Chemotherapy.

CONTEXT: Early palliative care is recommended within eight-week of diagnosing advanced cancer. Although guidelines suggest routine screening to identify cancer patients who could benefit from palliative care, implementing screening can be challenging due to understaffing and time constraints. OBJECTIVES: To develop and evaluate machine learning models for predicting specialist palliative care needs in advanced cancer patients undergoing chemotherapy, and to investigate if predictive models could substitute screening tools. METHODS: We conducted a retrospective cohort study using supervised machine learning. The study included patients aged 18 or older, diagnosed with metastatic or stage IV cancer, who underwent chemotherapy and distress screening at a designated cancer hospital in Japan from April 1, 2018, to March 31, 2023. Specialist palliative care needs were assessed based on distress screening scores and expert evaluations. Data sources were hospital's cancer registry, health claims database, and nursing admission records. The predictive model was developed using XGBoost, a machine learning algorithm. RESULTS: Out of the 1878 included patients, 561 were analyzed. Among them, 114 (20.3%) exhibited needs for specialist palliative care. After under-sampling to address data imbalance, the models achieved an Area Under the Curve (AUC) of 0.89 with 95.8% sensitivity and a specificity of 71.9%. After feature selection, the model retained five variables, including the patient-reported pain score, and showcased an 0.82 AUC. CONCLUSION: Our models could forecast specialist palliative care needs for advanced cancer patients on chemotherapy. Using five variables as predictors could replace screening tools and has the potential to contribute to earlier palliative care.

Patients with keratinization disorders due to ABCA12 variants showing pityriasis rubra pilaris phenotypes.

Pathogenic variants in ABCA12 are important causative genetic defects for autosomal recessive congenital ichthyoses (ARCI), which include congenital ichthyosiform erythroderma (CIE), harlequin ichthyosis, and lamellar ichthyosis. In addition, pathogenic variants in ABCA12 are known to cause a localized nevoid form of CIE due to recessive mosaicism. We previously reported siblings who carried an ABCA12 variant but did not show a "congenital" phenotype. They were considered to have pityriasis rubra pilaris (PRP). Here, we present a further patient with ABCA12 variants whose phenotype was not congenital ichthyosis, in an independent family. Notably, these three patients had geographic unaffected areas. Such areas are not usually found in patients with ARCI who have ABCA12 variants, suggesting mild phenotypes for these patients. Interestingly, the histological features of the ichthyotic lesions in these patients resembled those of PRP. All three patients had homozygous pathogenic missense variants in ABCA12. Our findings expand the phenotypic spectrum of patients with ABCA12 variants.

Transcription factor activating enhancer-binding protein 2B expression correlates with invasiveness and prognosis of extramammary Paget's disease.

BACKGROUND: Extramammary Paget's disease (EMPD) is a slowly advancing malignancy that sometimes progresses to the invasion of the dermis, systemic metastases, and death. Although there have been reports that dermal invasion is associated with poor prognosis, no molecular markers of this invasion have been identified thus far. The aim of this study was to identify key molecules for predicting the risk of EMPD dermis invasion. METHOD: We performed microarray screening for three cases of in-situ EMPDs, three cases of invasive EMPDs, and three cases of normal epidermis. We identified a molecule that exhibited a stepwise increase in expression. Further, we analyzed 47 cases of EMPD using immunohistochemical staining (IHC) and examined the correlated clinicopathological findings, including prognosis. RESULT: We examined molecules that showed stepwise differences with invasion. We focused on transcription factor activating enhancer-binding protein 2 B (TFAP2B). Of the 47 EMPD patients, 38 (80.9 %) and 9 (19.1 %) had low and high TFAP2B expression, respectively. TFAP2B expression was significantly correlated with invasion into the dermis, mass formation, and preoperative lymph node metastasis (p = 0.001, 0.042, and 0.033, respectively). The cumulative postoperative recurrence-free rate in the TFAP2B-high expression group was significantly lower than that in the TFAP2B-low expression group (P < 0.001). In univariate analysis of recurrence-free survival, TFAP2B expression was found to be a significant factor (p = 0.006). CONCLUSION: The expression of TFAP2B, which was comprehensively found by microarray screening, may correlate with the invasiveness of EMPD and may be an unfavorable prognostic factor.

Eruptive xanthomas as a marker for metabolic disorders: A specific form of xanthoma that reflects hypertriglyceridemia.

Eruptive xanthomas are skin manifestations associated with hypertriglyceridemia. Accordingly, the improvement of hypertriglyceridemia can ameliorate this condition. We report a case of a patient with type 2 diabetes mellitus who was diagnosed with this skin lesion. Clinicians should be aware that eruptive xanthomas could indicate metabolic disorders associated with atherosclerosis.

Programmed Death-Ligand 1 and Programmed Death-Ligand 2 Expression Can Affect Prognosis in Extramammary Paget's Disease.

BACKGROUND: Extramammary Paget's disease (EMPD) is a type of carcinoma that usually progresses slowly but may cause metastasis and subsequent death of patients. We investigated the relationship between the expression of programmed death-ligand 1 (PD-L1)/programmed death-ligand 2 (PD-L2) and stromal CD8+ tumor-infiltrating lymphocytes (TILs) in EMPD and clinicopathological findings, including prognosis. MATERIALS AND METHODS: We examined 47 cases of EMPD and performed immunohistochemical staining of formalin-fixed paraffin-embedded full-face sections. RESULTS: PD-L1 expression in tumor cells was observed in 13 cases (27.7%) while PD-L2 expression was observed in 21 cases (44.7%). The cumulative postoperative recurrence-free rate in the group with positivity for PD-L1 and/or PD-L2 with a low CD8+ TIL count was significantly lower than that of the corresponding group with a high CD8+ TIL count and of the PD-L1- and PD-L2-negative group (p=0.026). CONCLUSION: The expression of PD-L1/PD-L2 in tumor cells was shown to be a factor for poor prognosis.

Subcutaneous Cheek Nodule Associated with Granulomatosis with Polyangiitis.

We herein report an unusual case of granulomatosis with polyangiitis (GPA) in a 65-year-old man in whom relapsed disease manifested as an anterior cheek nodule. Magnetic resonance imaging indicated the differential diagnoses of the subcutaneous nodule in the patient's anterior cheek to be inflammatory granulomatous lesions with GPA, malignancy, or infectious disease. A histopathological examination ruled out malignancy and infectious diseases, and necrotizing vasculitis was suspected. The subcutaneous nodule was successfully treated using rituximab, suggesting that it was associated with GPA, secondary to vasculitis. Clinicians should be aware of the possibility of such a rare manifestation of GPA.

The medaka sex-determining gene DMY acquired a novel temporal expression pattern after duplication of DMRT1.

The male sex-determining gene, DMY, of the medaka is considered to have arisen via gene duplication of DMRT1. In the medaka, both genes are expressed in Sertoli cell lineage cells, but their temporal expression patterns are quite different. DMY expression starts just before the sex-determining period, whereas DMRT1 expression occurs during the testicular differentiation period. To evaluate the alterations to the expression patterns of the DMRT1 genes after duplication, we analyzed the morphological gonadal sex differentiation processes and expression patterns of DMRT1 in Oryzias luzonensis and Oryzias mekongensis, which are closely related to the medaka but do not have DMY. Male-specific upregulation of DMRT1 in these two species occurred during the testicular differentiation period, similar to the case for DMRT1 in the medaka. These findings suggest that DMY acquired a novel temporal expression pattern after duplication and that this event played a critical role in the evolutionary process of this gene.

Expression and function of purinergic P2Y12 receptors in rat trigeminal ganglion neurons.

Purinergic receptors play key signaling roles in neuropathic pain in the orofacial region, which is innervated by trigeminal ganglion (TG) neurons. The neuropathology of purinergic P2Y12 receptors is well characterized in glia; however, their physiological role in TG neurons remains to be fully elucidated. The present study investigated the expression and function of P2Y12 receptors in rat TG neurons. P2Y12 receptor immunoreactivity was intense in the soma, dendrites, and axons, and colocalized with a pan-neuronal marker, neurofilament H, isolectin B4, and substance P. In the presence of extracellular Ca(2+), 2-methylthio-ADP (an agonist of P2Y1, 12, 13 receptors) transiently increased intracellular free Ca(2+) concentrations ([Ca(2+)]i), an effect that was abolished by P2Y12 receptor antagonists. In the absence of extracellular Ca(2+), ryanodine receptor/channel inhibitors diminished the 2-methylthio-ADP-induced increases in [Ca(2+)]i. A sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) inhibitor gradually increased [Ca(2+)]i, and after a plateau, application of 2-MeS-ADP induced a rapid and transient, but additive increase in [Ca(2+)]i. An adenylate cyclase inhibitor transiently increased [Ca(2+)]i, while a phosphodiesterase inhibitor prevented the 2-methylthio-ADP-induced increase in [Ca(2+)]i. Our study shows that P2Y12 receptors are expressed in TG neurons, and act via a cAMP-dependent pathway to release intracellular Ca(2+) from ryanodine-sensitive Ca(2+) stores.

Functional expression of bradykinin B1 and B2 receptors in neonatal rat trigeminal ganglion neurons.

Bradykinin (BK) and its receptors (B1 and B2 receptors) play important roles in inflammatory nociception. However, the patterns of expression and physiological/pathological functions of B1 and B2 receptors in trigeminal ganglion (TG) neurons remain to be fully elucidated. We investigated the functional expression of BK receptors in rat TG neurons. We observed intense immunoreactivity of B2 receptors in TG neurons, while B1 receptors showed weak immunoreactivity. Expression of the B2 receptor colocalized with immunoreactivities against the pan-neuronal marker, neurofilament H, substance P, isolectin B4, and tropomyosin receptor kinase A antibodies. Both in the presence and absence of extracellular Ca(2+) ([Ca(2+)]o), BK application increased the concentration of intracellular free Ca(2+) ([Ca(2+)]i). The amplitudes of BK-induced [Ca(2+)]i increase in the absence of [Ca(2+)]o were significantly smaller than those in the presence of Ca(2+). In the absence of [Ca(2+)]o, BK-induced [Ca(2+)]i increases were sensitive to B2 receptor antagonists, but not to a B1 receptor antagonist. However, B1 receptor agonist, Lys-[Des-Arg(9)]BK, transiently increased [Ca(2+)]i in primary cultured TG neurons, and these increases were sensitive to a B1 receptor antagonist in the presence of [Ca(2+)]o. These results indicated that B2 receptors were constitutively expressed and their activation induced the mobilization of [Ca(2+)]i from intracellular stores with partial Ca(2+) influx by BK. Although constitutive B1 receptor expression could not be clearly observed immunohistochemically in the TG cryosection, cultured TG neurons functionally expressed B1 receptors, suggesting that both B1 and B2 receptors involve pathological and physiological nociceptive functions.

Functional expression of TRPM8 and TRPA1 channels in rat odontoblasts.

Odontoblasts produce dentin during development, throughout life, and in response to pathological conditions by sensing stimulation of exposed dentin. The functional properties and localization patterns of transient receptor potential (TRP) melastatin subfamily member 8 (TRPM8) and ankyrin subfamily member 1 (TRPA1) channels in odontoblasts remain to be clarified. We investigated the localization and the pharmacological, biophysical, and mechano-sensitive properties of TRPM8 and TRPA1 channels in rat odontoblasts. Menthol and icilin increased the intracellular free Ca(2+) concentration ([Ca(2+)]i). Icilin-, WS3-, or WS12-induced [Ca(2+)]i increases were inhibited by capsazepine or 5-benzyloxytriptamine. The increase in [Ca(2+)]i elicited by allyl isothiocyanate (AITC) was inhibited by HC030031. WS12 and AITC exerted a desensitizing effect on [Ca(2+)]i increase. Low-temperature stimuli elicited [Ca(2+)]i increases that are sensitive to both 5-benzyloxytriptamine and HC030031. Hypotonic stimulation-induced membrane stretch increased [Ca(2+)]i; HC030031 but not 5-benzyloxytriptamine inhibited the effect. The results suggest that TRPM8 channels in rat odontoblasts play a role in detecting low-temperature stimulation of the dentin surface and that TRPA1 channels are involved in sensing membrane stretching and low-temperature stimulation. The results also indicate that odontoblasts act as mechanical and thermal receptor cells, detecting the stimulation of exposed dentin to drive multiple cellular functions, such as sensory transduction.