Effects of Diabetes and Voluntary Exercise on IgA Concentration and Polymeric Immunoglobulin Receptor Expression in the Submandibular Gland of Rats.

Background and Objectives: Patients with diabetes are more susceptible to upper respiratory tract infections (URTIs) because they are easily infected. Salivary IgA (sali-IgA) levels play a major role in transmitting URTIs. Sali-IgA levels are determined by salivary gland IgA production and polymeric immunoglobulin receptor (poly-IgR) expression. However, it is unknown whether salivary gland IgA production and poly-IgR expression are decreased in patients with diabetes. While exercise is reported to increase or decrease the sali-IgA levels, it is unclear how exercise affects the salivary glands of patients with diabetes. This study aimed to determine the effects of diabetes and voluntary exercise on IgA production and poly-IgR expression in the salivary glands of diabetic rats. Materials and Methods: Ten spontaneously diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats (eight-week-old) were divided into two groups of five rats each: a non-exercise group (OLETF-C) and a voluntary wheel-running group (OLETF-E). Five Long-Evans Tokushima Otsuka (LETO) rats without diabetes were bred under the same conditions as the OLETF-C. Sixteen weeks after the study began, the submandibular glands (SGs) were collected and analyzed for IgA and poly-IgR expression levels. Results: IgA concentrations and poly-IgR expression levels in SGs were lower in OLETF-C and OLETF-E than in LETO (p < 0.05). These values did not differ between the OLETF-C and OLETF-E. Conclusions: Diabetes decreases IgA production and poly-IgR expression in the salivary glands of rats. Moreover, voluntary exercise increases sali-IgA levels but does not increase IgA production and poly-IgR expression in the salivary glands of diabetic rats. Increasing IgA production and poly-IgR expression in the salivary glands, which is reduced in diabetes, might require slightly higher-intensity exercise than voluntary exercise under the supervision of a doctor.

Prevalence of saliva immunoglobulin A antibodies reactive with severe acute respiratory syndrome coronavirus 2 among Japanese people unexposed to the virus.

While the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a threat to public health as the number of cases and COVID-19-related deaths are increasing worldwide, the incidence of the virus infection is extremely low in Japan compared with many other countries. To explain this uncommon phenomenon, we investigated the prevalence of naturally occurring ("natural") antibodies, focusing on those of the secretory immunoglobulin A (sIgA) form, reactive with SARS-CoV-2 among Japanese people. One hundred and eighty healthy Japanese volunteers of a wide range of age who had been considered to be unexposed to SARS-CoV-2 participated in this study. Saliva samples and blood samples were collected from all of the 180 participants and 139 adults (aged ≥ 20 years) included therein, respectively. The determination of saliva IgA antibodies, mostly comprising sIgA antibodies, as well as serum IgA and immunoglobulin G antibodies, reactive with the receptor binding domain of the SARS-CoV-2 spike-1 subunit proteins was conducted using an enzyme-linked immunosorbent assay. The major findings were that 52.78% (95% confidence interval, 45.21%-60.25%) of the individuals who had not been exposed to SARS-CoV-2 were positive for saliva IgA antibodies with a wide range of levels between 0.002 and 3.272 ng/mL, and that there may be a negative trend in positivity for the antibodies according to age. As we had expected, a frequent occurrence of assumable "natural" sIgA antibodies reactive with SARS-CoV-2 among the studied Japanese participant population was observed.

The significance of tyrosine kinase receptor B and brain-derived neurotrophic factor expression in salivary duct carcinoma.

Salivary duct carcinoma (SDC) is a high-grade salivary gland neoplasm. It may occur de novo or secondarily from pleomorphic adenoma (ex-PA), with secondary development accounting for more than 50% of the cases. In recent years, the expression of tyrosine kinase receptor B (TrkB), which is in the same family as HER2, has been confirmed in various types of carcinomas. However, there are a few studies on SDC. In order to examine the expression and role of TrkB in SDC, we investigated it. Immunohistochemistry was used to detect the expression of TrkB and its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4) in 20 patients with SDC. The mRNA levels of TrkB, BDNF, and NT-4 were analyzed using quantitative polymerase chain reaction. TrkB was negative in 10 cases and positive in 10 cases, BDNF was negative in 11 cases and positive in 9 cases, and NT-4 was positive in all cases. There was a high number of TrkB-positive cases in the pT4 group and The H-score of TrkB was also significantly higher in the stage III and IV groups. There was a high number of BDNF-positive cases in the ex-PA group and Histo-score of BDNF had a trend of high expression in ex-PA. There were no significant differences or correlations in mRNA expression. Our results suggest that TrkB may be involved in SDC tumor growth.

Existence of SARS-CoV-2 Entry Molecules in the Oral Cavity.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor, angiotensin-converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and furin, which promote entry of the virus into the host cell, have been identified as determinants of SARS-CoV-2 infection. Dorsal tongue and gingiva, saliva, and tongue coating samples were examined to determine the presence of these molecules in the oral cavity. Immunohistochemical analyses showed that ACE2 was expressed in the stratified squamous epithelium of the dorsal tongue and gingiva. TMPRSS2 was strongly expressed in stratified squamous epithelium in the keratinized surface layer and detected in the saliva and tongue coating samples via Western blot. Furin was localized mainly in the lower layer of stratified squamous epithelium and detected in the saliva but not tongue coating. ACE2, TMPRSS2, and furin mRNA expression was observed in taste bud-derived cultured cells, which was similar to the immunofluorescence observations. These data showed that essential molecules for SARS-CoV-2 infection were abundant in the oral cavity. However, the database analysis showed that saliva also contains many protease inhibitors. Therefore, although the oral cavity may be the entry route for SARS-CoV-2, other factors including protease inhibitors in the saliva that inhibit viral entry should be considered.

The Effect of TBB, as an Initiator, on the Biological Compatibility of PMMA/MMA Bone Cement.

Acrylic bone cement is widely used in orthopedic surgery for treating various conditions of the bone and joints. Bone cement consists of methyl methacrylate (MMA), polymethyl methacrylate (PMMA), and benzoyl peroxide (BPO), functioning as a liquid monomer, solid phase, and polymerization initiator, respectively. However, cell and tissue toxicity caused by bone cement has been a concern. This study aimed to determine the effect of tri-n-butyl borane (TBB) as an initiator on the biocompatibility of bone cement. Rat spine bone marrow-derived osteoblasts were cultured on two commercially available PMMA-BPO bone cements and a PMMA-TBB experimental material. After a 24-h incubation, more cells survived on PMMA-TBB than on PMMA-BPO. Cytomorphometry showed that the area of cell spread was greater on PMMA-TBB than on PMMA-BPO. Analysis of alkaline phosphatase activity, gene expression, and matrix mineralization showed that the osteoblastic differentiation was substantially advanced on the PMMA-TBB. Electron spin resonance (ESR) spectroscopy revealed that polymerization radical production within the PMMA-TBB was 1/15-1/20 of that within the PMMA-BPO. Thus, the use of TBB as an initiator, improved the biocompatibility and physicochemical properties of the PMMA-based material.

Effect of ingesting yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 on influenza virus-bound salivary IgA in elderly residents of nursing homes: a randomized controlled trial.

Objective: The purpose of this study was to clarify the influence of consuming yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 (1073R-1-yogurt) on influenza virus-bound salivary immunoglobulin A (IgA) levels, in the elderly residents of nursing homes. Methods: A double-blind, parallel-group, randomized controlled trial was conducted with 96 elderly volunteers residing in 2 nursing homes. During the trial, participants consumed 100 g of 1073R-1-yogurt every morning for 12 weeks, whereas the control participants consumed yogurt fermented with a different Lactobacillus strain (control yogurt). Saliva was collected before the trial and after 4, 8 and 12 weeks of yogurt ingestion. Results: Our data indicated that consumption of 1073R-1-yogurt affected influenza A virus subtype H3N2-bound IgA levels in saliva (p = .001). In addition, saliva flow rate and total IgA levels increased in response to the yogurt intake period in both the 1073R-1 and control yogurt groups (p = .04). Conclusions: Our study suggests that continuous daily ingestion of 1073R-1-yogurt may help prevent infection with influenza A virus subtype H3N2 in elderly subjects with weakened immunity, by increasing the production of influenza A virus subtype of H3N2-bound salivary IgA.

Effect of oral functional training on immunological abilities of older people: a case control study.

BACKGROUND: Oral functional ability decreases with age, and systemic immunological ability and quality of life can also deteriorate. Continuous moderate whole-body exercise for older people is known to improve oral functional and their immunological abilities. Here, we evaluated the effect of oral exercise as an alternative training method for highly older people who cannot perform whole-body exercises. METHODS: Unstimulated whole saliva samples had been collected for three times before training as baseline data and one time after 3 and 6 weeks of training each. Participants were instructed to conduct self-massage; their tongues were used to press their orbicularis oris muscle and buccinators, and instructed to perform bilateral massage of three major glands for facilitating saliva secretion. Medical histories, daily life habits and characteristics were also collected. RESULTS: Totally 30 participants (84.2 ± 8.5 years) were enrolled. In contrast to previous researches, increase in salivary Immunoglobulin A (IgA) after the training was not observed. Interestingly, hierarchical clustering analyses revealed clear individual variations as two prominent clusters and a strong positive correlation between stimulated saliva flow rate and IgA flow rate, regardless of the continuous oral functional exercise. Only body mass index (BMI) showed significant differences between the two groups (Z = 2.06, P = 0.039, Wilcoxon rank-sum test) among all collected parameters. CONCLUSION: Oral functional training limitedly effects on salivary parameters of highly older people. On the other hand, BMI characterized salivary features more than any other parameters, such as the presence of diseases or medication use in these people. TRIAL REGISTRATION: UMIN-CTR Clinical Trial UMIN000028394 on 27/July 2017, retrospectively registered.

Human ß-defensin-2 and interleukin-1ß expression in response to Porphyromonas gingivalis challenge in mice transplanted with periodontitic human gingiva.

Inter-individual variability in the host response contributes significantly to expression of periodontal disease. Thus, research into the human host response is considered important in the analysis of periodontal disease. Human ß-defensin-2 (hBD-2) is typically produced by epithelial tissues after stimulation with microorganisms and inflammatory mediators, and it contributes to the initial defense in the innate immune response. However, hBD-2 expression in response to infection has not been investigated in human gingival tissue with periodontitis. We examined the response to Porphyromonas gingivalis in an established in vivo model of human gingival grafts with various degrees of periodontitis. We also investigated the expression profile of interleukin-1ß (IL-1ß). Gingival tissues were collected from 40 patients with chronic periodontitis (21 with slight-to-moderate disease, 19 with severe disease) during tooth extraction or periodontal surgery. These tissues were transplanted subcutaneously into nu/nu mice. We used real-time PCR to compare the expression of hBD-2 and IL-1ß. In slight-to-moderate chronic periodontitis, hBD-2 expression was significantly higher in the stimulated group than in the non-stimulated group (p < 0.05), but there was no significant increase in the group with severe chronic periodontitis. IL-1ß expression did not differ between groups. Increased expression of hBD-2 and IL-1ß was associated with slight-to-moderate periodontitis (p < 0.05), and there was a significant relationship between decreased hBD-2 and IL-1ß expression and severe periodontitis (p < 0.05). The initial expression profile of hBD-2 in P. gingivalis infection differs according to the severity of periodontitis. In addition, changes in hBD-2 and IL-1ß expression may be important in the progression of periodontitis.

Salivary lactoferrin is transferred into the brain via the sublingual route.

Lactoferrin (LF) is produced by exocrine glands including salivary gland, and has various functions including infection defense. However, the transfer of LF from peripheral organs into the brain remains unclear. To clarify the kinetics of salivary LF (sLF), we investigated the consequences of sialoadenectomy and bovine LF (bLF) sublingual administration in rats. The salivary glands were removed from male Wistar rats, and we measured rat LF levels in the blood and brain at 1 week post-surgery. We also examined the transfer of LF into the organs of the rats after sublingual administration of bLF. Rat LF levels in the blood and brain were significantly reduced by sialoadenectomy. Sublingual bLF administration significantly increased bLF levels in the brain, which then decreased over time. These results indicate that LF is transferred from the sublingual mucosa to the brain, in which favorable effects of sLF on brain will be expected via the sublingual mucosa.

Salivary Gland Derived BDNF Overexpression in Mice Exerts an Anxiolytic Effect.

Brain-derived neurotrophic factor (BDNF) is abundant in the hippocampus and plays critical roles in memory and synapse formation, as well as exerting antidepressant-like effects in psychiatric disorders. We previously reported that BDNF is expressed in salivary glands and affects blood BDNF content. However, the function of salivary BDNF remains unclear. The aim of this study was to generate transgenic mice overexpressing BDNF in the salivary glands. Hence, we used the Lama construct (hemagglutinin (HA)-tagged mouse Bdnf cDNA) to specifically express BDNF in mouse salivary glands. Compared with control mice, Bdnf-HA transgenic mice showed increased blood BDNF and expressed salivary BDNF-HA. Molecular analysis revealed enhanced hippocampal BDNF levels and activation of the BDNF receptor, tyrosine kinase B (TrkB), in transgenic mice. In both the open field and elevated-plus maze tests, transgenic mice showed anxiolytic-like behavioral effects compared with control or sialoadenectomized mice. Among downstream components of the BDNF-TrkB signaling pathway, metabolic activation of the γ-aminobutyric acid (GABA) synthetic pathway was found, including higher levels of the GABA synthetic enzyme, glutamate decarboxylase 1 (GAD1). Thus, we have established a transgenic mouse expressing BDNF in the parotid gland that may be useful to examine the hippocampal effects of salivary BDNF.

Effects of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 on the IgA flow rate of saliva in elderly persons residing in a nursing home: A before-after non-randomised intervention study.

OBJECTIVE: The aim of this study was to investigate the alterations in the salivary IgA levels of elderly persons administered yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) OLL1073R-1, which has been reported to reduce the risk of colds. BACKGROUND: Salivary immunoglobulin (Ig)A plays an important role in the defence of the oral cavity mucous membrane against foreign antigens and pathogens. Accordingly, low levels of salivary IgA are associated with an increased risk of upper respiratory tract infection. Furthermore, salivary IgA secretion has been reported to decrease with age. Recently, several studies have reported that certain strains of Lactobacillus and their products can modulate the immune response, but there are currently few studies on the effects of on the IgA level in human saliva. MATERIALS AND METHODS: This was a before-after non-randomised intervention study. Thirty-seven elderly persons (mean age, 82.7 years) residing in a single nursing home ingested 112 g of the yogurt every morning for 12 weeks. The participants' saliva was collected before and after 4, 8 and 12 weeks of yogurt intake. RESULTS: Our results showed that yogurt intake affected the concentration of IgA in the saliva (P < .0001). Additionally, yogurt intake and the body weight of the participants affected the IgA flow rate of saliva (P = .0003 and .03, respectively). CONCLUSION: Continuous intake of yogurt fermented with L. bulgaricus OLL1073R-1 may help improve the mucosal immune function in elderly people with weakened immune systems.

Voluntary exercise increases IgA concentration and polymeric Ig receptor expression in the rat submandibular gland.

Salivary IgA-a primary factor in local immunity of the oral cavity-plays an important role in maintaining local immune function in the oral cavity and prevent upper respiratory tract infections. Oral IgA levels are known to fluctuate in an exercise-dependent manner; thus, we investigated the effects of voluntary exercise on salivary IgA secretion in rats to better understand the mechanism by which this occurs. Six-week-old male Wistar rats were placed in individual cages with or without access to exercise wheels for three weeks. Notably, animals who engaged in voluntary exercise demonstrated significant increases in IgA concentration in saliva and submandibular gland tissue, as well as a markedly higher salivary IgA flow rate. Moreover, active rats also exhibited elevated polymeric Ig receptor (pIgR) mRNA expression in submandibular gland tissue. Collectively, these results suggest that voluntary exercise may increase salivary IgA concentration and boost immune function in the oral cavity.

Relationship between salivary immunoglobulin a, lactoferrin and lysozyme flow rates and lifestyle factors in Japanese children: a cross-sectional study.

OBJECTIVE: The antimicrobial substances in saliva contribute to the maintenance of both oral health and overall health of the body. Therefore, the associations among immunoglobulin A (IgA), lactoferrin and lysozyme flow rates in the saliva of children, and their relationships with the physical attributes and lifestyle factors of children, were examined. MATERIALS AND METHODS: Saliva was collected from 90 children who visited the Kanagawa Dental University Hospital Pediatric Dentistry, and questionnaires were completed by guardians. IgA, lactoferrin and lysozyme concentrations were measured in the saliva samples using enzyme-linked immunosorbent assays (ELISAs). RESULTS: The IgA flow rate in saliva increased as age, height and weight increased. A correlation was found between lactoferrin and lysozyme flow rates. When the antimicrobial substance flow rates in the saliva were divided into two groups of 22 children each based on the highest and lowest quartiles, children with either a low or high IgA flow rate also had a high or low lactoferrin flow rate, respectively. The same pattern was observed for lactoferrin and lysozyme flow rates. CONCLUSIONS: There is a high probability that the IgA flow rate in the saliva of children reflects and corresponds to the developmental status of immune function as the child ages and increases in height and weight. The flow rates of lactoferrin and lysozyme were correlated in children. In addition, regarding lifestyle factors, the duration of sleep and lactoferrin flow rate were also related.

Intake of indigestible carbohydrates influences IgA response and polymeric Ig receptor expression in the rat submandibular gland.

Secretory IgA in the saliva is essential for protection from mucosally transmitted pathogens and maintaining homeostasis at mucosal surfaces of the oral cavity. Expression of submandibular gland polymeric Ig receptor (pIgR) is essential for IgA secretion. In the present study, we investigated the influence of indigestible carbohydrates on IgA production in the salivary gland and saliva. Five-week-old rats were fed a fibre-free diet (control), or a diet with 5 % (w/w) fructo-oligosaccharide (FOS) or a combination of 2·5 % (w/w) polydextrose (PDX) and 2·5 % (w/w) lactitol for 21-d. IgA concentrations in the caecal digesta, submandibular gland tissue, and saliva in the FOS and PDX+lactitol diet groups were significantly higher than those in the control group (P< 0·05). The increase in IgA in the submandibular gland tissue was confirmed using immunohistochemical analysis. However, the IgA concentrations of serum did not differ between the FOS or PDX+lactitol groups and the control group (P= 0·5). In the FOS and PDX+lactitol groups, the pIgR mRNA (pIgR/ß-actin) expression level in the submandibular gland tissue was significantly higher than that in the control group (P< 0·05). The present study suggests that indigestible carbohydrates play an important role in the increase in IgA concentrations in the submandibular gland tissue, saliva, and caecal digesta.

Intratumoral heterogeneity of HER2 protein and amplification of HER2 gene in salivary duct carcinoma.

Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands, and accounts for 1-3% of all malignant salivary gland tumors, resembling morphologically invasive ductal carcinoma (IDC) of the breast. In contrast to IDC of the breast and gastric carcinoma (GC), the study of human epidermal growth factor receptor 2 (HER2) in SDC has not progressed. Therefore, we investigated the relationship between HER2 protein expression and amplification of the HER2 gene, and compared them in terms of intratumoral heterogeneity (ITH) in 13 cases of SDC using immunohistochemistry and dual color in situ hybridization. We found seven cases with protein overexpression (53.8%) and five cases with gene amplification (38.5%) in accordance with ASCO/CAP guidelines. ITH of HER2 protein expression was seen in seven cases (53.8%). Interestingly, the ratio of the HER2 gene showed homogenous distribution with or without the presence of ITH of HER2 protein expression. SDC tends to have more ITH of HER2 protein similarly to GC, in contrast to IDC of the breast. ITH of HER2 protein in SDC has no heterogeneity of the HER2 gene amplification. The mechanism of HER2 protein expression in SDC might proceed through a more complex pathway relative to that of IDC of the breast.

Associations between brain-derived neurotrophic factor and estradiol in women's saliva.

OBJECTIVE: The aim of this study was to assess the relationship between brain-derived neurotrophic factor (BDNF) and sex hormones (estradiol [E2] and progesterone), using saliva samples obtained from healthy women. METHODS: Forty female dental hygienist students were divided into groups according to being in the follicular phase or luteal phase. Saliva BDNF, E2, and progesterone levels were measured using a sandwich ELISA system. The correlation between these factors was analyzed using Spearman's index, and fluctuations of these levels in the whole menstrual cycle were investigated classifying the subjects by every 4 days according to the phase of their menstrual cycle. RESULTS: Saliva BDNF variations strongly correlated with saliva E2 levels in the follicular phase (r = 0.721, p = 0.000) and luteal phase (r = 0.770, p = 0.000). The correlation coefficient showing the relationship between progesterone and BDNF levels in the luteal phase (r = 0.371, p = 0.157) was lower than that in the follicular phase (r = 0.631, p = 0.001). Moreover, the fluctuation of BDNF levels in the menstrual cycle followed a similar pattern to that of E2. CONCLUSIONS: We found that saliva BDNF and E2 levels were closely related in healthy young women. In particular, for first time, that correlation was investigated throughout the menstrual cycle. Monitoring of saliva BDNF may yield insight into women's reproductive and mental health.

Identification of citrullinated α1-antitrypsin (A1AT) in saliva in a mouse model of rheumatoid arthritis.

OBJECTIVES: Rheumatoid arthritis (RA) is an autoimmune disease characterized by progressive joint destruction. Early diagnosis and treatment, before joint deformation or destruction occurs, are crucial. Identifying novel biomarkers for RA in saliva could potentially enable early detection of the disease, prior to its onset. METHODS: We conducted a comprehensive proteomic analysis of salivary proteins in a mouse model of RA. Proteins were identified using western blotting and enzyme-linked immunosorbent assay in the serum, saliva, and ankle joints of DBA/1JJmsSlc mice, a model of RA. Ankle joints and submandibular glands were stained with hematoxylin and eosin and immunostained, and the results were compared with those of control mice. RESULTS: Citrullinated alpha-1 antitrypsin (A1AT, 46 kDa) was commonly detected in the saliva, serum, and ankle joints of mice with severe RA and was confirmed through proteomic analysis. Western blotting showed a band corresponding to 46 kDa in the serum, saliva, and ankle joints. Immunostaining of the ankle joints with the A1AT antibody showed a strong positive signal in the synovium. CONCLUSIONS: In DBA/1JJmsSlc mice, cyclic citrullinated peptide antibodies and A1AT may be involved in citrullination and contribute to the development and severity of RA, making them valuable treatment targets requiring further study.

Role of TrkB expression in rat adrenal gland during acute immobilization stress.

Expression of tyrosine receptor kinase B (TrkB), a receptor for brain-derived neurotrophic factor (BDNF), is markedly elevated in the adrenal medulla during immobilization stress. Catecholamine release was confirmed in vitro by stimulating chromaffin cells with recombinant BDNF. We investigated the role of TrkB and the localization of BDNF in the adrenal gland during immobilization stress for 60 min. Blood catecholamine levels increased after stimulation with TrkB expressed in the adrenal medulla during 60-min stress; however, blood catecholamine levels did not increase in adrenalectomized rats. Furthermore, expression of BDNF mRNA and protein was detected in the adrenal medulla during 60-min stress. Similarly, in rats undergoing sympathetic nerve block with propranolol, BDNF mRNA and protein were detected in the adrenal medulla during 60-min stress. These results suggest that signal transduction of TrkB in the adrenal medulla evokes catecholamine release. In addition, catecholamine release was evoked by both the hypothalamic-pituitary-adrenal axis and autocrine signaling by BDNF in the adrenal gland. BDNF-TrkB interaction may play a role in a positive feedback loop in the adrenal medulla during immobilization stress.

ΔNp63 silencing, DNA methylation shifts, and epithelial-mesenchymal transition resulted from TAp63 genome editing in squamous cell carcinoma.

TP63 (p63) is strongly expressed in lower-grade carcinomas of the head and neck, skin, breast, and urothelium to maintain a well-differentiated phenotype. TP63 has two transcription start sites at exons 1 and 3' that produce TAp63 and ΔNp63 isoforms, respectively. The major protein, ΔNp63α, epigenetically activates genes essential for epidermal/craniofacial differentiation, including ΔNp63 itself. To examine the specific role of weakly expressed TAp63, we disrupted exon 1 using CRISPR-Cas9 homology-directed repair in a head and neck squamous cell carcinoma (SCC) line. Surprisingly, TAp63 knockout cells having either monoallelic GFP cassette insertion paired with a frameshift deletion allele or biallelic GFP cassette insertion exhibited ΔNp63 silencing. Loss of keratinocyte-specific gene expression, switching of intermediate filament genes from KRT(s) to VIM, and suppression of cell-cell and cell-matrix adhesion components indicated the core events of epithelial-mesenchymal transition. Many of the positively and negatively affected genes, including ΔNp63, displayed local DNA methylation changes. Furthermore, ΔNp63 expression was partially rescued by transfection of the TAp63 knockout cells with TAp63α and application of DNA methyltransferase inhibitor zebularine. These results suggest that TAp63, a minor part of the TP63 gene, may be involved in the auto-activation mechanism of ΔNp63 by which the keratinocyte-specific epigenome is maintained in SCC.

Point-of-Care Diagnostic Biosensors to Monitor Anti-SARS-CoV-2 Neutralizing IgG/sIgA Antibodies and Antioxidant Activity in Saliva.

Monitoring biomarkers is a great way to assess daily physical condition, and using saliva instead of blood samples is more advantageous as the process is simple and allows individuals to test themselves. In the present study, we analyzed the titers of neutralizing antibodies, IgG and secretory IgA (sIgA), in response to the SARS-CoV-2 vaccine, in saliva. A total of 19 saliva and serum samples were collected over a 10-month period 3 weeks after the first vaccine, 8 months after the second vaccine, and 1 month after the third vaccine. The ranges of antibody concentrations post-vaccination were: serum IgG: 81-15,000 U/mL, salivary IgG: 3.4-330 U/mL, and salivary IgA: 58-870 ng/mL. A sharp increase in salivary IgG levels was observed after the second vaccination. sIgA levels also showed an increasing trend. A correlation with trends in serum IgG levels was observed, indicating the possibility of using saliva to routinely assess vaccine efficacy. The electrochemical immunosensor assay developed in this study based on the gold-linked electrochemical immunoassay, and the antioxidant activity measurement based on luminol electrochemiluminescence (ECL), can be performed using portable devices, which would prove useful for individual-based diagnosis using saliva samples.