Clinicopathologic and Immunohistochemical Findings from Autopsy of Patient with COVID-19, Japan.

An autopsy of a patient in Japan with coronavirus disease indicated pneumonia lung pathology, manifested as diffuse alveolar damage. We detected severe acute respiratory syndrome coronavirus 2 antigen in alveolar epithelial cells and macrophages. Coronavirus disease is essentially a lower respiratory tract disease characterized by direct viral injury of alveolar epithelial cells.

Keratin 13 gene is epigenetically suppressed during transforming growth factor-ß1-induced epithelial-mesenchymal transition in a human keratinocyte cell line.

Epithelial-mesenchymal transition (EMT) is a biological event in which epithelial cells lose their polarity and cell-cell adhesions and concomitantly acquire mesenchymal traits, and is thought to play an important role in pathological processes such as wound healing and cancer progression. In this study, we evaluated transforming growth factor (TGF)-ß1-treated human keratinocyte HaCaT cells as an in vitro model of EMT. HaCaT cells were changed into an elongated fibroblast-like morphology, which is indicative of EMT in response to TGF-ß1. Phalloidin staining demonstrated the formation of actin stress fibers in TGF-ß1-treated cells. Quantitative RT-PCR analysis revealed that TGF-ß1 increased the mRNA levels of EMT transcription factors (SNAI2, TWIST1, and ZEB1) and mesenchymal markers (CDH2, VIM, and FN1), while it decreased the transcripts of epithelial phenotypic genes (CLDN1, OCLN, KRT5, KRT15, KRT13, and TGM1). Furthermore, we found that KRT13 was drastically suppressed through the reduction of RNA polymerase II occupancy of its promoter, which was accompanied by a decrease in active histone marks (H3K4me3 and H3K27ac) and an increase in a repressive mark (H3K27me3) during EMT. These findings indicate that the TGF-ß1-induced EMT program regulates a subset of epithelial and mesenchymal marker genes, and that KRT13 is transcriptionally suppressed through the modulation of the chromatin state at the KRT13 promoter in HaCaT cells.

10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, enhances energy metabolism by activation of TRPV1.

Gut microbiota can regulate the host energy metabolism; however, the underlying mechanisms that could involve gut microbiota-derived compounds remain to be understood. Therefore, in this study, we investigated the effects of KetoA [10-oxo-12(Z)-octadecenoic acid]-a linoleic acid metabolite produced by gut lactic acid bacteria-on whole-body energy metabolism and found that dietary intake of KetoA could enhance energy expenditure in mice, thereby protecting mice from diet-induced obesity. By using Ca2+ imaging and whole-cell patch-clamp methods, KetoA was noted to potently activate transient receptor potential vanilloid 1 (TRPV1) and enhance noradrenalin turnover in adipose tissues. In addition, KetoA up-regulated genes that are related to brown adipocyte functions, including uncoupling protein 1 (UCP1) in white adipose tissue (WAT), which was later diminished in the presence of a ß-adrenoreceptor blocker. By using obese and diabetic model KK-Ay mice, we further show that KetoA intake ameliorated obesity-associated metabolic disorders. In the absence of any observed KetoA-induced antiobesity effect or UCP1 up-regulation in TRPV1-deficient mice, we prove that the antiobesity effect of KetoA was caused by TRPV1 activation-mediated browning in WAT. KetoA produced in the gut could therefore be involved in the regulation of host energy metabolism.-Kim, M., Furuzono, T., Yamakuni, K., Li, Y., Kim, Y.-I., Takahashi, H., Ohue-Kitano, R., Jheng, H.-F., Takahashi, N., Kano, Y., Yu, R., Kishino, S., Ogawa, J., Uchida, K., Yamazaki, J., Tominaga, M., Kawada, T., Goto, T. 10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, enhances energy metabolism by activation of TRPV1.

Role of Thermo-Sensitive Transient Receptor Potential Channels in Brown Adipose Tissue.

Brown and beige adipocytes are a major site of mammalian non-shivering thermogenesis and energy dissipation. Obesity is caused by an imbalance between energy intake and expenditure and has become a worldwide health problem. Therefore modulation of thermogenesis in brown and beige adipocytes could be an important application for body weight control and obesity prevention. Over the last few decades, the involvement of thermo-sensitive transient receptor potential (TRP) channels (including TRPV1, TRPV2, TRPV3, TRPV4, TRPM4, TRPM8, TRPC5, and TRPA1) in energy metabolism and adipogenesis in adipocytes has been extensively explored. In this review, we summarize the expression, function, and pathological/physiological contributions of these TRP channels and discuss their potential as future therapeutic targets for preventing and combating human obesity and obesity-related metabolic disorders.

The tiny-leaved orchid Cephalanthera subaphylla obtains most of its carbon via mycoheterotrophy.

The evolution of mycoheterotrophy has been accompanied by extreme reductions in plant leaf size and photosynthetic capacity. Partially mycoheterotrophic plants, which obtain carbon from both photosynthesis and their mycorrhizal fungi, include species with leaves of normal size and others that are tiny-leaved. Thus, plant species may lose their leaves in a gradual process of size reduction rather than through a single step mutation. Little is known about how the degree of mycoheterotrophy changes during reductions in leaf size. We compared the degree of mycoheterotrophy among five Japanese Cephalanthera species, four with leaves of normal size (Cephalanthera falcata, Cephalanthera erecta, Cephalanthera longibracteata and Cephalanthera longifolia), one with tiny leaves (Cephalanthera subaphylla), and one albino form of C. falcata (as reference specimens for fully mycoheterotrophic plants). The levels of mycoheterotrophy were determined by stable isotope natural abundance analysis. All Cephalanthera species were relatively enriched in 13C and 15N in comparison with surrounding autotrophic plants. Cephalanthera subaphylla was strongly enriched in 13C and 15N to levels similar to the albinos. Species with leaves of normal size were significantly less enriched in 13C than C. subaphylla and the albinos. Thus, C. subaphylla was strongly mycoheterotrophic, obtaining most of its carbon from mycorrhizal fungi even though it has tiny leaves; species with leaves of normal size were partially mycoheterotrophic. Hence, during the evolutionary pathway to full mycoheterotrophy, some plant species appear to have gained strong mycoheterotrophic abilities before completely losing foliage leaves.

3-Deazaneplanocin A suppresses aggressive phenotype-related gene expression in an oral squamous cell carcinoma cell line.

In tumor tissues, alterations of gene expression caused by aberrant epigenetic modifications confer phenotypic diversity on malignant cells. Although 3-deazaneplanocin A (DZNep) has been shown to reactivate tumor suppressor genes in several cancer cells, it remains unclear whether DZNep attenuates the malignant phenotypes of oral squamous cell carcinoma (OSCC) cells. In this study, we investigated the effect of DZNep on the expression of genes related to aggressive phenotypes, such as epithelial-mesenchymal transition, in OSCC cells. We found that DZNep reduced the cellular levels of polycomb group proteins (EZH2, SUZ12, BMI1, and RING1A) and the associated trimethylation of Lys27 on histone H3 and monoubiquitination of Lys119 on histone H2A in the poorly differentiated OSCC cell line SAS. Immunocytochemical staining demonstrated that DZNep induced the reorganization of filamentous actin and the membrane localization of E-cadherin associated with cell-cell adhesions. We also found an inhibitory effect of DZNep on cell proliferation using a WST assay. Finally, quantitative RT-PCR analysis demonstrated that genes involved in the aggressive phenotypes (TWIST2, EGFR, ACTA2, TGFB1, WNT5B, and APLIN) were down-regulated, whereas epithelial phenotype genes (CDH1, CLDN4, IVL, and TGM1) were up-regulated in SAS cells treated with DZNep. Collectively, our findings suggest that DZNep reverses the aggressive characteristics of OSCC cells through the dynamic regulation of epithelial plasticity via the reprogramming of gene expression patterns.

Integrin α6ß4 and TRPV1 channel coordinately regulate directional keratinocyte migration.

The directional migration of epithelial cells is crucial for wound healing. Among integrins, a family of cell adhesion receptors, integrin ß4 has been assumed to be a promigratory factor, in addition to its role in stable adhesion. In turn, Ca(2+) signaling is also a key coordinator of migration. Keratinocytes reportedly express transient receptor potential vanilloid channels (TRPV1); however, the function of these channels as a regulator of intracellular Ca(2+) level in cell migration has remained uncharacterized. In the present study, we investigated the role of TRPV1 in directional migration related to integrin ß4 using a scratch wound assay on a confluent monolayer sheet of murine keratinocytes (Pam212 cells). Double immunofluorescence staining revealed the de novo expression of integrin ß4 and TRPV1 in migrating cells at the wound edge in response to scratch wounding, and both expression levels were almost matched. Epidermal growth factor (EGF) not only promoted keratinocyte migration, but also caused the further up-regulation of both integrin ß4 and TRPV1. In addition, the knockdown of the integrin ß4 or TRPV1 gene significantly impeded wound closure. The TRPV1 agonist capsaicin significantly promoted migration, while a selective TRPV1 antagonist inhibited it. The gene knockdown of TRPV1 inhibited the expression of the integrin ß4 gene and that of ß4 protein in migrating cells. These findings suggest that TRPV1 may stimulate directional migration directly by eliciting a Ca(2+) signal or indirectly via integrin ß4 expression.

CLCA splicing isoform associated with adhesion through ß1-integrin and its scaffolding protein: specific expression in undifferentiated epithelial cells.

We previously found that a rat CLCA homologue (rCLCA-f) modulates Ca(2+)-dependent Cl(-) transport in the ductal cells of the rat submandibular gland. CLCA proteins have been shown to be multifunctional, with roles in, for example, cell adhesion. Here, we describe the mRNA and protein expressions of a splicing isoform of rat rCLCA (rCLCA-t). This isoform is a 514-amino acid protein containing a C-terminal 59-amino acid that is distinct from the rCLCA-f sequence. Immunohistochemistry revealed rCLCA-t to be located in the basal cells of the rat submandibular gland excretory duct and the stratum basale of rat epidermis, whereas rCLCA-f was detected in cells during the process of differentiation. In a heterologous expression system, rCLCA-t was found to be a membrane protein present predominantly in the perinuclear region, and not to be either present on the cell surface or secreted. rCLCA-t failed to enhance ionomycin-induced Cl(-) conductance (unlike rCLCA-f). When compared with rCLCA-f, it weakened cell attachment to a greater extent and in a manner that was evidently modulated by intracellular Ca(2+), protein kinase C, and ß(1)-integrin. rCLCA-t was found to associate with RACK1 (receptor for activated C kinase) and to reduce expression of mature ß(1)-integrin. Treatment of rat skin with rCLCA-t siRNA increased the expression of ß(1)-integrin in the stratum basale of the epidermis. These results are consistent with cell-specific splicing of rCLCA mRNA playing a role in the modulation of the adhesive potential of undifferentiated epithelial cells.

Epigenetic alterations of the keratin 13 gene in oral squamous cell carcinoma.

BACKGROUND: Epigenetic modifications play important roles in the regulation of gene expression determining cellular phenotype as well as various pathologies such as cancer. Although the loss of keratin 13 (KRT13) is reportedly linked to malignant transformation of oral epithelial cells, the molecular mechanisms through which KRT13 is repressed in oral squamous cell carcinoma (OSCC) remain unclear. The aim of this study is to identify the epigenetic alterations of the KRT13 gene in OSCCs. METHODS: We investigated KRT13 expression levels and chromatin modifications of the KRT13 promoter in the three OSCC cell lines (HSC4, HSC3, and SAS). The expression levels of KRT13 protein and mRNA were analyzed by western blotting and quantitative reverse-transcription polymerase chain reaction, respectively, and the localization of KRT13 protein was detected by immunofluorescence. DNA methylation and histone modifications in the KRT13 promoter were determined by bisulfite sequencing and chromatin immunoprecipitation (ChIP), respectively. For the pharmacological depletion of Polycomb repressive complex 2 (PRC2), cells were treated with 3-deazaneplanocin A (DZNep). RESULTS: KRT13 expression was transcriptionally silenced in the HSC3 and SAS cells and post-transcriptionally repressed in the HSC4 cells, while the KRT13 promoter was hypermethylated in all of the three OSCC cell lines. ChIP analysis revealed that PRC2-mediated trimethylation of Lys 27 on histone H3 (H3K27me3) was increased in the KRT13 promoter in the HSC3 and SAS cells. Finally, we demonstrated that the treatment of SAS cells with DZNep reactivated the transcription of KRT13 gene. CONCLUSIONS: Our data provide mechanistic insights into the epigenetic silencing of KRT13 genes in OSCC cells and might be useful for the development of diagnostic markers and novel therapeutic approaches against OSCCs.

Proteolytic and non-proteolytic activation of keratinocyte-derived latent TGF-ß1 induces fibroblast differentiation in a wound-healing model using rat skin.

Transforming growth factor-ß1 (TGF-ß1) reportedly causes the differentiation of fibroblasts to myofibroblasts during wound healing. We investigated the mechanism underlying the activation of latent TGF-ß1 released by keratinocytes in efforts to identify promising pharmacological approaches for the prevention of hypertrophic scar formation. A three-dimensional collagen gel matrix culture was prepared using rat keratinocytes and dermal fibroblasts. Stratified keratinocytes promoted the TGF receptor-dependent increase in α-smooth muscle actin (α-SMA) immunostaining and mRNA levels in fibroblasts. Latent TGF-ß1 was found to be localized suprabasally and secreted. α-SMA expression was inhibited by an anti-αv-integrin antibody and a matrix metalloproteinase (MMP) inhibitor, GM6001. In a two-dimensional fibroblast culture, α-SMA expression depended on the production of endogenous TGF-ß1 and required αv-integrin or MMP for the response to recombinant latent TGF-ß1. In keratinocyte-conditioned medium, MMP-dependent latent TGF-ß1 secretion was detected. Applying this medium to the fibroblast culture enhanced α-SMA production. This effect was decreased by GM6001, the anti-αv-integrin antibody, or the preabsorption of latent TGF-ß1. These results indicate that keratinocytes secrete latent TGF-ß1, which is liberated to fibroblasts over distance and is activated to produce α-SMA with the aid of a positive-feedback loop. MMP inhibition was effective for targeting both keratinocytes and fibroblasts in this model.

Canine, mouse, and human transient receptor potential ankyrin 1 (TRPA1) channels show different sensitivity to menthol or cold stimulation.

Transient receptor potential ankyrin 1 (TRPA1) is a nonselective cation channel that is activated by a variety of stimuli and acts as a nociceptor. Mouse and human TRPA1 exhibit different reactivity to some stimuli, including chemicals such as menthol as well as cold stimuli. The cold sensitivity of TRPA1 in mammalian species is controversial. Here, we analyzed the reactivity of heterologously expressed canine TRPA1 as well as the mouse and human orthologs to menthol or cold stimulation in Ca2+-imaging experiments. Canine and human TRPA1 exhibited a similar response to menthol, that is, activation in a concentration-dependent manner, even at the high concentration range in contrast to the mouse ortholog, which did not respond to high concentration of menthol. In addition, the response during the removal of menthol was different; mouse TRPA1-expressing cells exhibited a typical response with a rapid and clear increase in [Ca2+]i ("off-response"), whereas [Ca2+]i in human TRPA1-expressing cells was dramatically decreased by the washout of menthol and [Ca2+]i in canine TRPA1-expressing cells was slightly decreased. Finally, canine TRPA1 as well as mouse and human TRPA1 were activated by cold stimulation (below 19-20°C). The sensitivity to cold stimulation differed between these species, that is, human TRPA1 activated at higher temperatures compared with the canine and mouse orthologs. All of the above responses were suppressed by the selective TRPA1 inhibitor HC-030031. Because the concentration-dependency and "off-response" of menthol as well as the cold sensitivity were not uniform among these species, studies of canine TRPA1 might be useful for understanding the species-specific functional properties of mammalian TRPA1.

Dual signaling pathways of arterial constriction by extracellular uridine 5'-triphosphate in the rat.

We investigated actions of uridine 5'-triphosphate (UTP) in rat aorta, cerebral and mesenteric arteries, and their single myocytes. UTP (≥10 µM) elicited an inward-rectifying current strongly reminiscent of activation of P2X(1) receptor, and a similar current was also induced by α,ß-methylene adenosine 5'-triphosphate (ATP) (≥100 nM). UTP desensitized α,ß-methylene ATP-evoked current, and vice versa. The UTP-activated current was insensitive to G-protein modulators, TRPC3 inhibitors, or TRPC3 antibody, but was sensitive to P2-receptor inhibitors or P2X(1)-receptor antibody. Both UTP (1 mM) and α,ß-methylene ATP (10 µM) elicited similar conductance single channel activities. UTP (≥10 µM) provoked a dose-dependent contraction of de-endothelialized aortic ring preparation consisting of phasic and tonic components. Removal of extracellular Ca(2+) or bath-applied 2',3'-O-(2,4,6-trinitrophenyl)-ATP (TNP-ATP) (30 µM) or nifedipine (10 µM) completely inhibited the phasic contraction while only partially reducing the tonic one. The tonic contraction was almost completely abolished by additional application of thapsigargin (2 µM). Similar biphasic rises in [Ca(2+)](i) were also evoked by UTP in rat aortic myocytes. In contrast to the low expression of TRPC3, significant expression of P2X(1) receptor was detected in all arteries by RT-PCR and immunoblotting, and its localization was limited to plasma membrane of myocytes as indicated by immunohistochemistry. These results suggest that UTP dually activates P2X(1)-like and P2Y receptors, but not TRPC3.

Four Cases of Coronavirus Disease 2019 Transferred from a Cruise Ship.

An outbreak of coronavirus disease 2019 (COVID-19) that began in Wuhan, China, has spread rapidly to many countries. We herein report four cases of COVID-19 confirmed in Japan among passengers of the cruise ship Diamond Princess and describe the clinical features, clinical course, and progression of chest computed tomographic images, chest radiographs, and treatment. Although these four patients had symptoms that included a fever, malaise, runny nose, and cough, one patient had no symptoms on admission. Two of the four patients needed mechanical ventilation due to respiratory deterioration. One of the patients who required mechanical ventilation was transferred to a higher-level medical institution. Except for that patient, the other three patients were able to return home under their own power. Every patient took lopinavir/ritonavir, which was considered the most effective treatment at the time. We used it after receiving approval from the ethics committee in our hospital. In this case report, we emphasize that some patients need to be carefully monitored, even if their respiratory condition is stable at the initial presentation, as their respiratory status may deteriorate rapidly within a few days after oxygen administration begins.

Involvement of pore helix in voltage-dependent inactivation of TRPM5 channel.

The transient receptor potential melastatin 5 (TRPM5) channel is a monovalent-permeable cation channel that is activated by intracellular Ca2+. Expression of TRPM5 has been shown in taste cells, pancreas, brainstem and olfactory epithelium, and this channel is thought to be involved in controlling membrane potentials. In whole-cell patch-clamp recordings, TRPM5 exhibited voltage-dependent inactivation at negative membrane potentials and time constant of voltage-dependent inactivation of TRPM5 did not depend on the intracellular Ca2+ concentrations between 100 and 500 nM. Alanine substitution at Y913 and I916 in the pore helix of TRPM5 increased time constant of voltage-dependent inactivation. Meanwhile, voltage-dependent inactivation was reduced in TRPM5 mutants having glycine substitution at L901, Y913, Q915 and I916 in the pore helix. From these results, we conclude that the pore helix in the outer pore loop might play a role in voltage-dependent inactivation of TRPM5.

Is light quality involved in the regulation of the photosynthetic apparatus in attached rice leaves?

The regulatory effect of light quality on the photosynthetic apparatus in attached leaves of rice plants was investigated by keeping rice plants under natural light, in complete darkness, or under illumination with light of different colors. When leaves were left in darkness and far-red (FR)-light conditions for 6 days at 30 degrees C, there was an initial lag in chlorophyll (Chl) content, Chl a/b ratio, and maximum photosystem (PS) II photochemistry that lasted until the second day; these then rapidly decreased on the fourth day. In contrast, ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) rapidly disappeared with no lag under low or zero light conditions. By using spectrophotometric quantitation, it was determined that the PSII and PSI reaction centers were regulated by light quality, but cytochrome (Cyt) f was regulated by light intensity. However, the PSII heterogeneity was also strongly modified by the light intensity; PSIIalpha with the large antenna decreased markedly both in content and in antenna size. Consequently, the PSIIalpha/PSI ratio declined under FR-light because the low intensity of FR-light dominated over its quality in the modulation of the PSIIalpha/PSI ratio. An imbalance between them induced the generation of reactive oxygen species (ROS), although the ROS were scavenged by stromal enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR). The activities of these stromal enzymes are also regulated by light quality. Thus, although the photosynthetic apparatus is regulated differently depending on light quality, light quality may play an important role in the regulation of the photosynthetic apparatus.

Tarantula toxin ProTx-I differentiates between human T-type voltage-gated Ca2+ Channels Cav3.1 and Cav3.2.

ProTx-I peptide, a venom toxin of the tarantula Thrixopelma pruriens, has been reported to interact with voltage-gated ion channels. ProTx-I reduced Ba(2+) currents through recombinant human T-type voltage-gated Ca(2+) channels, Ca(v)3.1 (hCa(v)3.1), with roughly 160-fold more potency than through hCa(v)3.2 channels. Chimeric channel proteins (hCa(v)3.1/S3S4 and hCa(v)3.2/S3S4) were produced by exchanging fourteen amino acids in the hCa(v)3.1 domain IV S3-S4 linker region and the corresponding region of hCa(v)3.2 between each other. The ProTx-I sensitivity was markedly reduced in the hCa(v)3.1/S3S4 chimera as compared to the original hCa(v)3.1 channel, while the hCa(v)3.2/S3S4 chimera exhibited greater ProTx-I sensitivity than the original hCa(v)3.2 channel. These results suggest that the domain IV S3-S4 linker in the hCa(v)3.1 channel may contain residues involved in the interaction of ProTx-I with T-type Ca(2+) channels.

CLC-3 chloride channels in the pulmonary vasculature.

Volume-sensitive outwardly rectifying anion channels (VSOACs) are expressed in pulmonary artery smooth muscle cells (PASMCs) and have been implicated in cell proliferation, growth, apoptosis and protection against oxidative stress. In this chapter, we review the properties of native VSOACs in PASMCs, and consider the evidence that ClC-3, a member of the ClC superfamily of voltage dependent Cl- channels, may be responsible for native VSOACs in PASMCs. Finally, we examine whether or not native VSOACs and heterologously expressed ClC-3 channels function as bona fide chloride channels or as chloride/proton antiporters.

Cerebral Infarction and Myalgia in a 75-year-old Man with Eosinophilic Granulomatosis with Polyangiitis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare condition of systemic vasculitis of small to medium-sized blood vessels. We herein report the case of a 75-year-old man who presented with hemiplegia on his right side due to cerebral infarction following myalgia and a high fever. He had no history of asthma or allergic rhinitis. He was diagnosed with EGPA based on the presence of eosinophilia, sinusitis suggested by magnetic resonance imaging, and muscle pathology. His hemiplegia improved rapidly after corticosteroid therapy. This case suggests that EGPA should be a differential diagnosis of cerebral infarction with myalgia and eosinophilia.

Non-Transcriptional and Translational Function of Canonical NF-κB Signaling in Activating ERK1/2 in IL-1ß-Induced COX-2 Expression in Synovial Fibroblasts.

The pro-inflammatory cytokine interleukin 1ß (IL-1ß) induces the synthesis of prostaglandin E2 by upregulating cyclooxygenase-2 (COX-2) in the synovial tissue of individuals with autoimmune diseases, such as rheumatoid arthritis (RA). IL-1ß-mediated stimulation of NF-κB and MAPK signaling is important for the pathogenesis of RA; however, crosstalk(s) between NF-κB and MAPK signaling remains to be understood. In this study, we established a model for IL-1ß-induced synovitis and investigated the role of NF-κB and MAPK signaling in synovitis. We observed an increase in the mRNA and protein levels of COX-2 and prostaglandin E2 release in cells treated with IL-1ß. NF-κB and ERK1/2 inhibitors significantly reduced IL-1ß-induced COX-2 expression. IL-1ß induced the phosphorylation of canonical NF-κB complex (p65 and p105) and degradation of IκBα. IL-1ß also induced ERK1/2 phosphorylation but did not affect the phosphorylation levels of p38 MAPK and JNK. IL-1ß failed to induce COX-2 expression in cells transfected with siRNA for p65, p105, ERK1, or ERK2. Notably, NF-κB inhibitors reduced IL-1ß-induced ERK1/2 phosphorylation; however, the ERK1/2 inhibitor had no effect on the phosphorylation of the canonical NF-κB complex. Although transcription and translation inhibitors had no effect on IL-1ß-induced ERK1/2 phosphorylation, the silencing of canonical NF-κB complex in siRNA-transfected fibroblasts prevented IL-1ß-induced phosphorylation of ERK1/2. Taken together, our data indicate the importance of the non-transcriptional/translational activity of canonical NF-κB in the activation of ERK1/2 signaling involved in the IL-1ß-induced development of autoimmune diseases affecting the synovial tissue, such as RA.

Identification and classification of a new TRPM3 variant (γ subtype).

TRPM3 is a non-selective cation channel that is activated by neural steroids such as pregnenolone sulfate, nifedipine, and clotrimazole. Despite the number of TRPM3 variants, few reports have described functional analyses of these different TRPM3 types. Here we identified a new TRPM variant from mouse dorsal root ganglion, termed TRPM3γ3. We classified TRPM3γ3 and another known variant (variant 6) into the γ subtype, and analyzed the TRPM3γ variants. mRNA expression of TRPM3γ was higher than that of TRPM3α variants in the mouse dorsal root ganglion. In Ca2+-imaging of HEK293 cells expressing either the TRPM3γ variants or TRPM3α2, increases in cytosolic Ca2+ concentrations ([Ca2+]i) induced by pregnenolone sulfate or nifedipine were smaller in cells expressing the TRPM3γ variants compared to those expressing TRPM3α2. On the other hand, co-expression of TRPM3γ variants had no effect on [Ca2+]i increases induced by pregnenolone sulfate or nifedipine treatment of HEK293 cells expressing TRPM3α2. In Xenopus oocytes, small responses of TRPM3γ variants to chemical agonists compared to TRPM3α2 were also observed. Interestingly, Xenopus oocytes expressing TRPM3α2 displayed heat-evoked currents with clear thresholds of about 40 °C that were larger than those evoked in oocytes expressing TRPM3γ variants. Overall, these findings indicate that TRPM3γ variants have low channel activity compared to TRPM3α.