Self-reported Smell and Taste Disorders in Patients With COVID-19: A Japanese Single-center Study.

Background/aim: Smell and taste disorders are among the most common symptoms of COVID-19. However, the relationship between smell and taste disorders and systemic symptoms is not fully understood in Japan.

Patients And Methods: Questionnaires were mailed to 105 of 111 COVID-19 patients who were hospitalized at our hospital between March and July 2020 in Japan.

Dysfunction of epithelial permeability barrier induced by HMGB1 in 2.5D cultures of human epithelial cells.

Airway and intestinal epithelial permeability barriers are crucial in epithelial homeostasis. High mobility group box 1 (HMGB1), increased by various stimuli, is involved in the induction of airway inflammation, as well as the pathogenesis of inflammatory bowel disease. HMGB1 enhances epithelial hyperpermeability.

Effects of HMGB1 on Tricellular Tight Junctions via TGF-β Signaling in Human Nasal Epithelial Cells.

The airway epithelium of the human nasal mucosa acts as a physical barrier that protects against inhaled substances and pathogens via bicellular and tricellular tight junctions (bTJs and tTJs) including claudins, angulin-1/LSR and tricellulin. High mobility group box-1 (HMGB1) increased by TGF-β1 is involved in the induction of nasal inflammation and injury in patients with allergic rhinitis, chronic rhinosinusitis, and eosinophilic chronic rhinosinusitis. However, the detailed mechanisms by which this occurs remain unknown.

Induction of airway progenitor cells via p63 and KLF11 by Rho-kinase inhibitor Y27632 in hTERT-human nasal epithelial cells.

Rho-kinase inhibitor Y27632, which is a factor in conditional reprogramming culture, induces airway progenitor clone formation. To investigate whether Y27632 enhances airway progenitor cells in nasal epithelium, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were treated with Y27632. In TERT-HNECs treated with Y27632 for 5 days, upregulation of p63, gap junction molecules Cx26, Cx30, Cx43, cytochrome P450 enzymes CYP2C9, CYP2C18, CYP39A1, CYP4B1, CYP2G1P, CYP4Z1, and KLF families KLF10 and KLF11 were observed compared to the control.

The role of transcriptional factor p63 in regulation of epithelial barrier and ciliogenesis of human nasal epithelial cells.

Disruption of nasal epithelial tight junctions (TJs) and ciliary dysfunction are found in patients with chronic rhinosinusitis (CRS) and nasal polyps (NPs), along with an increase of p63-positive basal cells and histone deacetylase (HDAC) activity. To investigate these mechanisms, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were transfected with siRNAs of TAp63 and ΔNp63, treated with the NF-kB inhibitor curucumin and inhibitors of HDACs, and infected with respiratory syncytial virus (RSV). In TERT-HNECs, knockdown of p63 by siRNAs of TAp63 and ΔNp63, induced claudin-1 and -4 with Sp1 activity and enhanced barrier and fence functions.

Poly(I:C) induced microRNA-146a regulates epithelial barrier and secretion of proinflammatory cytokines in human nasal epithelial cells.

Human nasal epithelial cells (HNECs) are important in the tight junctional barrier and innate immune defense protecting against pathogens invading via Toll-like receptors (TLRs). MicroRNAs (miRNAs) regulate expression of tight junctions as direct or indirect targeting genes and maintain the barrier function. However, the roles of miRNAs in the epithelial barrier of HNECs via TLRs remain unknown.

Regulation of tight junctions in upper airway epithelium.

The mucosal barrier of the upper respiratory tract including the nasal cavity, which is the first site of exposure to inhaled antigens, plays an important role in host defense in terms of innate immunity and is regulated in large part by tight junctions of epithelial cells. Tight junction molecules are expressed in both M cells and dendritic cells as well as epithelial cells of upper airway. Various antigens are sampled, transported, and released to lymphocytes through the cells in nasal mucosa while they maintain the integrity of the barrier.

Hop water extract inhibits double-stranded RNA-induced thymic stromal lymphopoietin release from human nasal epithelial cells.

Background: Thymic stromal lymphopoietin (TSLP) acts as a master switch for allergic inflammation and plays a key role in allergic diseases, including allergic rhinitis. Double-stranded RNA (dsRNA) recognized by Toll-like receptor 3 (TLR3) strongly activates TSLP release from human nasal epithelial cells (HNECs). Hop (Humulus lupulus L.

Mucosal immune barrier and antigen-presenting system in human nasal epithelial cells.

The upper respiratory tract including the nasal cavity, which is the first site of invading antigen exposure, plays a crucial role in host defense via the mucosal immune response. The epithelium of nasal mucosa forms a continuous barrier against a wide variety of exogenous antigens. The epithelial barrier function is regulated in large part by the apical-most intercellular junction, referred to as the tight junction.

A nuclear factor-κB signaling pathway via protein kinase C δ regulates replication of respiratory syncytial virus in polarized normal human nasal epithelial cells.

Respiratory syncytial virus (RSV) is the major cause of bronchitis, asthma, and severe lower respiratory tract disease in infants and young children. The airway epithelium, which has a well-developed barrier regulated by tight junctions, is the first line of defense during respiratory virus infection. In upper airway human nasal epithelial cells (HNECs), however, the primary site of RSV infection, the mechanisms of replication and budding of RSV, and the epithelial cell responses, including the tight junctional barrier, remain unknown.

Altered expression of claudin-1, claudin-7, and tricellulin regardless of human papilloma virus infection in human tonsillar squamous cell carcinoma.

Conclusions: Altered expression of claudin-1, claudin-7, and tricellulin in early tonsillar squamous cell carcinoma (SCC) independent of human papilloma virus (HPV) infection may lead to tumor progression.

Objectives: Integral tight junction proteins, the claudins and tricellulin, play a crucial role in all tissues. HPV is significantly associated with tonsillar SCC.

Epithelial barrier and antigen uptake in lymphoepithelium of human adenoids.

Invasion of antigens through the mucosal surface can be prevented by the common mucosal immune system, including Peyer's patches (PPs) and nasopharyngeal-associated lymphoreticular tissue (NALT). The adenoids (nasopharyngeal tonsils) comprise one of the NALTs and constitute the major part of Waldeyer's lymphoid ring in humans. However, the role of the lymphoepithelium, including M cells and dendritic cells (DCs), in the adenoids is unknown compared with the epithelium of PPs.

Poly(I:C) reduces expression of JAM-A and induces secretion of IL-8 and TNF-α via distinct NF-κB pathways in human nasal epithelial cells.

Human nasal epithelium is an important physical barrier and innate immune defense protecting against inhaled substances and pathogens. Toll-like receptor (TLR) signaling, which plays a key role in the innate immune response, has not been well characterized in human nasal epithelial cells (HNECs), including the epithelial tight junctional barrier. In the present study, mRNAs of TLR1-10 were detected in hTERT-transfected HNECs, which can be used as an indispensable and stable model of normal HNECs, similar to primary cultured HNECs.

c-Jun N-terminal kinase is largely involved in the regulation of tricellular tight junctions via tricellulin in human pancreatic duct epithelial cells.

Tricellulin (TRIC) is a tight junction protein at tricellular contacts where three epithelial cells meet, and it is required for the maintenance of the epithelial barrier. To investigate whether TRIC is regulated via a c-Jun N-terminal kinase (JNK) pathway, human pancreatic HPAC cells, highly expressed at tricellular contacts, were exposed to various stimuli such as the JNK activators anisomycin and 12-O-tetradecanoylphorbol 13-acetate (TPA), and the proinflammatory cytokines IL-1β, TNFα, and IL-1α. TRIC expression and the barrier function were moderated by treatment with the JNK activator anisomycin, and suppressed not only by inhibitors of JNK and PKC but also by siRNAs of TRIC.

PPARgamma agonists upregulate the barrier function of tight junctions via a PKC pathway in human nasal epithelial cells.

Peroxisome proliferator activated (PPAR)gamma plays a critical role in the control of not only adipocyte differentiation, lipid metabolism and immunity but also the barrier functions of epithelial and endothelial cells. In the present study, to investigate effects of PPAR gamma agonists on the tight junctional barrier of human nasal epithelial cells (HNECs), hTERT-transfected HNECs, which highly express both PPAR gamma and tight junction proteins, were treated with the PPAR gamma agonists rosiglitazone and troglitazone. Treatment with the PPAR gamma agonists enhanced the barrier function of hTERT-transfected HNECs together with the upregulation of tight junction molecules claudin-1 and -4, occludin, and tricellulin at the transcriptional level.

Expression and localization of tricellulin in human nasal epithelial cells in vivo and in vitro.

Tricellulin was identified as the first marker of the tricellular tight junction, which forms at the meeting points of three cells, and it is required for the maintenance of the transepithelial barrier. Although it is also considered to be important for the mucosal barrier of the upper respiratory tract, little is known about its expression and localization. In the present study, we examined the expression and localization of tricellulin in normal human nasal epithelial cells in vivo and in vitro, especially using primary cultures and telomerase reverse transcriptase (hTERT)-transfected cells.

Induction of JAM-A during differentiation of human THP-1 dendritic cells.

Junctional adhesion molecule (JAM)-A is not only localized at tight junctions of endothelial and epithelial cells but is also expressed on circulating leukocytes and dendritic cells (DCs). In the present study, to investigate the regulation of JAM-A in DCs, mature DCs were differentiated from the human monocytic cell THP-1 by treatment with IL-4, GM-CSF, TNF-alpha, and ionomycin, and some cells were pretreated with the PPAR-gamma agonists. In the THP-1 monocytes, mRNAs of tight junction molecules, occludin, tricellulin, JAM-A, ZO-1, ZO-2 and claudin-4, -7, -8, and -9 were detected by RT-PCR.

Studies on interactions between functional foods or dietary supplements and medicines. IV. Effects of ginkgo biloba leaf extract on the pharmacokinetics and pharmacodynamics of nifedipine in healthy volunteers.

The effects of Ginkgo biloba leaf extract (GBE), a widely used herbal dietary supplement in Japan, on the pharmacokinetics and pharmacodynamics of nifedipine (NFP), a calcium-channel blocker, were studied using 8 healthy volunteers. Simultaneous oral ingestion of GBE (240 mg) did not significantly affect any of the mean pharmacokinetic parameters of either NFP or dehydronifedipine, a major metabolite of NFP, after oral administration of NFP (10 mg). However, the maximal plasma NFP concentrations in 2 subjects were approximately doubled by GBE, and they had severer and longer-lasting headaches with GBE than without GBE, with dizziness or hot flushes in combination with GBE.