Study Profile of the Tsuruoka Metabolomics Cohort Study (TMCS)

The Tsuruoka Metabolomics Cohort Study (TMCS) is an ongoing population-based cohort study being conducted in the rural area of Yamagata Prefecture, Japan. This study aimed to enhance the precision prevention of multi-factorial, complex diseases, including non-communicable and aging-associated diseases, by improving risk stratification and prediction measures. At baseline, 11,002 participants aged 35-74 years were recruited in Tsuruoka City, Yamagata Prefecture, Japan, between 2012 and 2015, with an ongoing follow-up survey. Participants underwent various measurements, examinations, tests, and questionnaires on their health, lifestyle, and social factors. This study used an integrative approach with deep molecular profiling to identify potential biomarkers linked to phenotypes that underpin disease pathophysiology and provide better mechanistic insights into social health determinants. The TMCS incorporates multi-omics data, including genetic and metabolomic analyses of 10,933 participants and comprehensive data collection ranging from physical, psychological, behavioral, and social to biological data. The metabolome is used as a phenotypic probe because it is sensitive to changes in physiological and external conditions. The TMCS focuses on collecting outcomes for cardiovascular disease, cancer incidence and mortality, disability, functional decline due to aging and disease sequelae, and the variation in health status within the body represented by omics analysis that lies between exposure and disease. It contains several sub-studies on aging, heated tobacco products, and women's health. This study is notable for its robust design, high participation rate (89%), and long-term repeated surveys. Moreover, it contributes to precision prevention in Japan and East Asia as a well-established multi-omics platform.

Effect of digital messages from health professionals on COVID-19-related outcomes: A systematic review of randomized controlled trials

Effectiveness of health professionals' messages via digital tools on COVID-19-related outcomes remains unknown. In this systematic review, we examined this issue by searching randomized controlled trials in six databases until August, 2022 (PROSPERO, CRD 42022350788). Risk of bias was assessed using revised Cochrane risk-of-bias tool. Primary outcomes were COVID-19 infections, preventive behaviors, and factors that support behavioral change. Seven trials with 16 reports (some reported two or more outcomes) were included. One trial showed that physician videos distributed by Facebook ads significantly reduced COVID-19 infections. Five of 6 reports showed that interventions can promote non-pharmaceutical preventive behaviors, vaccination, or information-seeking behaviors and half of the results were significant. Interventions improved the factors that support behavioral change. 14 reports had some concerns of bias risk and 2 had high risk of bias. Our findings suggest that digital messages by health professionals may help reduce COVID-19 infections through promoting behavioral change.

Screening practices of cancer survivors and individuals whose family or friends had a cancer diagnoses-a nationally representative cross-sectional survey in Japan (INFORM Study 2020)

PURPOSE

We examined cancer screening practices and related beliefs in cancer survivors and individuals with family or close friends with a cancer diagnosis compared to individuals without the above cancer history for 5 population-based (gastric, colorectal, lung, breast, cervical) and 1 opportunistic (prostate) cancer screenings using nationally representative cross-sectional survey in Japan.

METHODS

We analyzed 3269 data from 3605 respondents (response rate, 37.1%) and compared the screening beliefs and practices of cancer survivors (n = 391), individuals with family members (n = 1674), and close friends with a cancer diagnosis (n = 685) to those without any cancer history (n = 519).

RESULTS

Being a cancer survivor was associated with screening for gastric (OR, 1.75; 95% CI, 1.04-2.95), colorectal (OR, 1.56; 95% CI, 1.03-2.36), and lung cancer (OR, 1.71; 95% CI, 1.10-2.66) but not breast, cervical cancer or PSA test. Having a family cancer diagnosis was associated with colorectal and lung cancer screening. Having friends with a cancer diagnosis was associated with PSA test. Cancer survivors and family members perceived themselves as being more susceptible and worried about getting cancer than individuals without any cancer history. Cancer survivors strongly believed screening can detect cancer and were more likely to undergo screening. Subgroup analysis indicated an interrelation between gastric and colorectal cancer screening among survivors.

CONCLUSIONS

A cancer diagnosis in oneself or family or friend influences an individual's health-related belief and risk perception, which can increase the likelihood of cancer screening.

IMPLICATIONS FOR CANCER SURVIVORS

Targeted and tailored communication strategies can increase awareness of cancer screening.

Patterns of alcohol and alcohol-flavoured non-alcoholic beverage advertisements over Japanese free-to-air television networks

Background

Alcohol use is a serious public health challenge worldwide. Japan has no government regulations or legal penalties against advertising alcoholic beverages on television (TV). Instead, advertisements depend on the Japanese alcohol industry’s self-regulation on airtime (no advertisements from 5 am to 6 pm) and the content of alcoholic beverages, which must not tempt minors. However, many adolescents (10 to 19 years old) watch TV from 6 pm to 11 pm. The aim of this study was to describe the pattern in the advertising of alcoholic beverages and alcohol-flavoured non-alcoholic beverages (AFNAB) in Japan during the popular TV viewing time for adolescents.

Methods

A secondary analysis of advertising airtime data from five free-to-air Japanese TV networks in the Greater Tokyo area that aired between 12 August and 3 November 2019, was performed.

Results

During the study period, 5215 advertisements for alcoholic beverages and AFNABs aired (1451.75 min). In total, 2303 advertisements (44.2%) were beer, low-malt beer, or beer-taste beverages, 277 (5.3%) were whisky, 2334 (44.8%) were local alcoholic beverages (shochu and seishu), and 301 (5.8%) were AFNAB. On average, more advertisements aired on weekends (67.6 advertisements) than on weekdays (59.3 advertisements) per day. Approximately 30% of advertisements for AFNABs were aired during the time restricted for alcohol advertising, although AFNABs are considered alcohol according to industry guidelines. During the popular television viewing time for young adolescents, about two to three times more advertisements were aired per hour than during the rest of the day, on both weekdays and weekends (p < 0.001).

Conclusion

The number of alcohol advertisements aired at times when adolescents often watch TV is 2 to 3.2 times higher than that at other times of the day. Furthermore, despite the industry’s self-imposed regulations, some alcoholic beverages are still advertised. Therefore, other methods to protect children and adolescents from exposure to advertisements for alcoholic beverages should be investigated and implemented.

POS1424 RISK FACTORS FOR ADVERSE EVENTS OF SULFAMETHOXAZOLE-TRIMETHOPRIM PROPHYLAXIS IN PATIENTS WITH SYSTEMIC RHEUMATIC DISEASES

Background

The prophylactic use of sulfamethoxazole-trimethoprim (SMX/TMP) can reduce the risk for developing pneumocystis pneumonia in immunosuppressed patients with systemic rheumatic diseases, whereas discontinuation of SMX/TMP prophylaxis is frequent due to adverse events (AEs) with this drug.

Objectives

The purpose of this study was to identify risk factors for AEs of SMX/TMP in patients with systemic rheumatic diseases.

Methods

All consecutive patients who were admitted in our hospital for induction treatment between 2012 and 2019 and newly received prophylactic SMX/TMP were included in the study. We divided them into two groups according to the presence or absence of AEs of SMX/TMP leading to discontinuation of the drug and compared clinical characteristics between the AE and non-AE groups. Multivariable analysis was performed to identify risk factors for AEs of SMX/TMP prophylaxis.

Results

A total of 438 patients were included in the study. Rheumatic diseases of the patients were systemic lupus erythematosus (25.3%), anti-neutrophil cytoplasmic antibody associated vasculitis (15.5%), rheumatoid arthritis (11.6%), polymyositis/dermatomyositis (10.7%), IgG4-related disease (8.5%), large vessel vasculitis (7.1%), adult-onset Still’s disease (AOSD; 4.1%), and others (17.2%). Among them, 82 patients (18.7%) stopped SMX/TMP due to AEs. Most frequent AEs were skin rash (36.6%), followed by liver dysfunction (29.3%), thrombocytopenia (19.5%), elevation in serum creatinine levels (15.9%), hyperkalemia (14.6%), hyponatremia (11%), leukopenia (6.1%), and fever (6.1%). Baseline age (61.4±16.4 vs 56.3±16.9 years, p=0.014) and prednisolone dose for remission induction treatment (0.97 vs 0.91 mg/kg/day, p=0.03) were significantly higher in the AE group than in the non-AE group, respectively. In terms of disease type, significantly higher rates of AEs were observed in patients with AOSD than in those with the other diseases (66.7% vs 16.7%, p<0.001; Figure 1). Blood tests at SMX/TMP initiation demonstrated lower lymphocyte counts (10.1 vs 10.8 x102/μl, p=0.049), lower platelet counts (20.9 vs 25.8 x104/μl, p=0.045), lower albumin levels (3.2 vs 3.4 g/dl, p=0.007), higher AST levels (26 vs 23 U/L, p=0.04), higher creatinine levels (0.71 vs 0.67 mg/dl, p=0.047), and higher ferritin levels (167 vs 154 ng/ml, p=0.047) in the AEs group compared with the non-AEs group, respectively. Multivariable analysis identified an older age (OR 1.03, p=0.002) and AOSD (OR 9.72, p<0.001) as independent risk factors for AEs leading to SMX/TMP withdrawal (Table 1).

Conclusion

Old age and AOSD were associated with AEs of SMX/TMP prophylaxis in patients with systemic rheumatic diseases.

Disclosure of Interests

None declared

AB0621 Characteristics of Anti-Neutrophil Cytoplasmic Antibody Associated Vasculitis With Severe Peripheral Neuropathy

Background

Peripheral neuropathy is one of major manifestations of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and has a significant impingement on patients’ quality of life.1,2

Objectives

The aim of this study was to clarify clinical features of AAV patients with peripheral neuropathy and identify risk factors for severe motor neuropathy.

Methods

All consecutive patients with active, treatment-naïve AAV who were admitted to our hospital between April, 2012 and October, 2021 were reviewed. Patients were divided into two groups according to the presence or absence of peripheral neuropathy, and their baseline clinical characteristics were compared.

Results

A total of 76 patients (microscopic polyangiitis, MPA, n=37, granulomatosis with poly angiitis, GPA, n=24, eosinophilic GPA, EGPA, n=15) were included in the study. Among them, 28 patients (36.8%) had peripheral neuropathy including 12 with MPA, 4 with GPA, and 12 with EGPA. The clinical characteristics of all patients with peripheral neuropathy were younger age (66.0 years versus 74.5 years, p<0.05) and showed higher white blood cell counts (11500/μL versus 8800/μL, p<0.05), higher blood eosinophil counts (788.5/μL versus 139.0/μL, p<0.05), higher creatinine clearance (77.3 mL/min versus 56.3 mL/min, p<0.05), higher levels of serum immunoglobulin (Ig)E (660 IU/mL versus 125 IU/mL, p<0.05), and IgG4 (361.5 mg/dL versus 84.0 mg/dL, p <0.05). In patients with EGPA, the most susceptible type to peripheral neuropathy, 80% of the patients had peripheral neuropathy. Comparison between patients with EGPA with peripheral neuropathy and those without demonstrated significantly younger age (56.0 years versus 80.0 years, p<0.05) and higher blood eosinophil counts (7832/μL versus 2340/μL, p<0.05) were characteristic for the presence of peripheral neuropathy. Patients with EGPA with motor neuropathy (n=8) showed higher white blood cell counts (26850//μL versus 8650//μL, p <0.05) and higher blood eosinophil counts (13134//μL versus 3436//μL, p<0.05) compared with those with only sensory neuropathy (n=4).

Conclusion

Our current study has shown that patients with EGPA are more prone to peripheral neuropathy than patients with MPA or GPA. Severe motor neuropathy was observed only in patients with EGPA and associated with more intense eosinophilic inflammation. Our results suggest that molecular targeted therapy that improves eosinophilic inflammation such as anti-IL-5 therapy is beneficial for peripheral neuropathy.

References

[1]RUTGERS, Abraham; KALLENBERG, Cees GM. Peripheral neuropathy in AAV—when vasculitis hits a nerve. Nature Reviews Rheumatology, 2012, 8.3: 127-128.

[2]NAKAZAWA, Daigo, et al. Pathogenesis and therapeutic interventions for ANCA-associated vasculitis. Nature Reviews Rheumatology, 2019, 15.2: 91-101.

Disclosure of Interests

None declared

Cutaneous ischemia-reperfusion injury is exacerbated by IL-36 receptor antagonist deficiency

BACKGROUND

Loss-of-function homozygous or compound heterozygous mutations in IL36RN, which encodes interleukin-36 receptor antagonist (IL-36Ra), has been implicated in the pathogenesis of skin disorders. However, the pathogenic role of IL-36Ra in cutaneous ischemia-reperfusion (I/R) injury remains unclear.

OBJECTIVES

We investigated the role of IL36Ra in cutaneous I/R injury.

METHODS

We examined I/R injury in Il36rn^-/- mice. The area of wounds, numbers of infiltrated cells, apoptotic cells and neutrophil extracellular trap (NET) formation were assessed. The expression levels of various genes were analysed using real-time RT-PCR. The expression of high mobility group box 1 (HMGB1), an endogenous toll-like receptor (TLR) 4 ligand, was confirmed using immunohistology, and serum HMGB1 levels were measured by ELISA. Cytokine production by stimulated cultured J774A.1 and HaCaT cells was examined.

RESULTS

IL-36Ra deficiency resulted in significantly delayed wound healing and increased neutrophil and macrophage infiltration into the wound tissues. Il36rn^-/- mice had increased mRNA expression levels of CXCL1, CXCL2, CCL4, TNF-α, TGF-β, IL-1β, IL-6 and IL-36γ relative to wild-type mice. Apoptosis was identified in keratinocytes by TUNEL assay. HMGB1 expression in the I/R site was decreased in both keratinocytes and adnexal cells, while serum HMGB1 levels were significantly elevated after reperfusion. The mRNA levels of various cytokines, including IL-1β, were elevated in J774A.1 cells through TLR4 signalling by HMGB1 stimulation. In addition, HaCaT cells stimulated with IL-1β showed significantly increased CXCL1, TNF-α, IL-6, IL-36β and IL-36γ mRNA expression. Furthermore, NET formation was increased by IL-36Ra deficiency. Finally, either the blockade of TLR4 signalling by TAK-242 or inhibition of NET formation by Cl-amidine normalized exacerbated I/R injury in Il36rn^-/- mice.

CONCLUSIONS

This study indicated that IL-36Ra deficiency exacerbates cutaneous I/R injury due to excessive inflammatory cell recruitment, NET formation, and excessive cytokine and chemokine production via the TLR4 pathway by HMGB1 released from epidermal apoptotic cells.

Isolated autosomal recessive woolly hair/hypotrichosis: genetics, pathogenesis and therapies

Isolated autosomal recessive woolly hair/hypotrichosis (ARWH) is a rare hereditary hair disease characterized by tightly curled sparse hair at birth or in early infancy. Patients with ARWH consist of genetically heterogeneous groups. Woolly hair autosomal recessive 1 (ARWH1) (MIM #278150), woolly hair autosomal recessive 2 (ARWH2) (MIM #604379) and woolly hair autosomal recessive 3 (ARWH3) (MIM #616760) are caused by mutations in LPAR6, LIPH and KRT25, respectively. In addition, nonsense variants in C3ORF52 (*611956) were identified in ARWH patients. The frequencies of the mutations in the causative genes in ARWH patients are thought to differ by ethnicity and country/geographical area. Large numbers of ARWH families with LIPH mutations have been described only in populations from Japan, Pakistan and the Volga-Ural region of Russia. In that region of Russia, most ARWH families have an extremely prevalent founder mutation, the deletion of exon 4, in LIPH. In the Pakistani population, 47.2% of ARWH families had the disease due to LIPH mutations and 52.8% of them carried LPAR6 mutations. The prevalent, recurrent LIPH mutation c.659_660delTA (p.Ile220Argfs*29) was found in more than half of Pakistani ARWH families with LIPH mutations. Most Japanese ARWH families (98.7%) harbour LIPH mutations, including the two highly prevalent, recurrent LIPH mutations c.736T>A (p.Cys246Ser) and c.742C>A (p.His248Asn). In ARWH patients whose disease was due to LIPH, LPAR6 or C3ORF52 mutations, the loss of function of LIPH, LPAR6 or C3ORF52 leads to reduced LIPH-LPA-LPAR6 signalling, resulting in the decreased transactivation of EGFR signalling and the phenotype of underdeveloped hairs. Our recent prospective interventional study suggests that topical minoxidil might be a promising treatment for ARWH due to LIPH mutations, although sufficiently effective treatments have not been established for ARWH yet.

Charged metabolite biomarkers of food intake assessed via plasma metabolomics in a population-based observational study in Japan

Food intake biomarkers can be critical tools that can be used to objectively assess dietary exposure for both epidemiological and clinical nutrition studies. While an accurate estimation of food intake is essential to unravel associations between the intake and specific health conditions, random and systematic errors affect self-reported assessments. This study aimed to clarify how habitual food intake influences the circulating plasma metabolome in a free-living Japanese regional population and to identify potential food intake biomarkers. To achieve this aim, we conducted a cross-sectional analysis as part of a large cohort study. From a baseline survey of the Tsuruoka Metabolome Cohort Study, 7,012 eligible male and female participants aged 40-69 years were chosen for this study. All data on patients' health status and dietary intake were assessed via a food frequency questionnaire, and plasma samples were obtained during an annual physical examination. Ninety-four charged plasma metabolites were measured using capillary electrophoresis mass spectrometry, by a non-targeted approach. Statistical analysis was performed using partial-least-square regression. A total of 21 plasma metabolites were likely to be associated with long-term food intake of nine food groups. In particular, the influential compounds in each food group were hydroxyproline for meat, trimethylamine-N-oxide for fish, choline for eggs, galactarate for dairy, cystine and betaine for soy products, threonate and galactarate for carotenoid-rich vegetables, proline betaine for fruits, quinate and trigonelline for coffee, and pipecolate for alcohol, and these were considered as prominent food intake markers in Japanese eating habits. A set of circulating plasma metabolites was identified as potential food intake biomarkers in the Japanese community-dwelling population. These results will open the way for the application of new reliable dietary assessment tools not by self-reported measurements but through objective quantification of biofluids.

Relationship of living arrangement with the decline in functional capacity in elderly people by gender: a longitudinal observational study

Background

The living arrangement has been suggested as an important factor affecting health. Recent studies have also suggested that there was a risk among elderly persons who were not alone. This study examined whether the detailed living arrangement was associated with a future decline in functional capacity in the elderly, by gender, in a Japanese suburban city.

Methods

A 3-year longitudinal questionnaire survey (baseline: 2011; follow-up: 2014) for aged 65 years or older was conducted in Kurihara city, Japan. Of the respondents in the baseline survey, we analyzed those who scored 13 points (a perfect score which indicates the highest functional capacity; n = 2627) on the Tokyo Metropolitan Institute of Gerontology Index of Competence at the baseline. The exposure was living arrangement at baseline, divided into five categories: “with spouse only,” “living alone,” “with child and his/her spouse,” “with child without his/her spouse,” and “with other family/person.” The outcome was the decline in functional capacity at the follow-up survey (score decreased to 10 points or less from 13 points).

Results

Of the 2627 analyzed population, 1199 (45.6%) were men. The incidence of the decline was 5.8% in men and 5.9% in women. Multivariable logistic regression analyses adjusted for age, educational attainment, and health behavior and condition revealed that in women, the odds ratio of the decline was higher in living with child and his/her spouse (2.41, 95% confidence interval; 1.10–5.28) referring to living with spouse only. When adjusting activities inside and outside the home such as housework additionally, the association was attenuated to marginal significance (2.25, 0.98–5.18). No statistical significance was observed in men.

Conclusions

These results suggested that living with child and spouse of a child was associated with the future decline in women’s functional capacity.

Imperceptible magnetic sensor matrix system integrated with organic driver and amplifier circuits

Artificial electronic skins (e-skins) comprise an integrated matrix of flexible devices arranged on a soft, reconfigurable surface. These sensors must perceive physical interaction spaces between external objects and robots or humans. Among various types of sensors, flexible magnetic sensors and the matrix configuration are preferable for such position sensing. However, sensor matrices must efficiently map the magnetic field with real-time encoding of the positions and motions of magnetic objects. This paper reports an ultrathin magnetic sensor matrix system comprising a 2 × 4 array of magnetoresistance sensors, a bootstrap organic shift register driving the sensor matrix, and organic signal amplifiers integrated within a single imperceptible platform. The system demonstrates high magnetic sensitivity owing to the use of organic amplifiers. Moreover, the shift register enabled real-time mapping of 2D magnetic field distribution.

Association between dyslipidemia and plasma levels of branched-chain amino acids in the Japanese population without diabetes mellitus

BACKGROUND

Branched-chain amino acids (BCAAs) play a key role in energy homeostasis.

OBJECTIVE

We aimed to investigate the association between plasma BCAA levels and dyslipidemia in the Japanese population without diabetes mellitus.

METHODS

This cross-sectional study included 4952 participants without diabetes mellitus, enrolled in the Tsuruoka Metabolomic Cohort Study. Plasma BCAA levels were measured by capillary electrophoresis-mass spectrometry. Correlations between lipid and BCAA profiles were evaluated by sex-stratified multiple linear regression analyses, after adjusting for confounders. Logistic regression was used to identify associations between BCAAs and metabolic dyslipidemia (MD) defined as triglyceride levels ≥150 mg/dL, high-density lipoprotein cholesterol levels ≤40 mg/dL for men and ≤50 mg/dL for women, or low-density lipoprotein cholesterol (LDL-C) levels ≥140 mg/dL.

RESULTS

In both sexes, the levels of individual BCAAs and the total BCAA levels correlated positively with triglyceride levels and negatively with high-density lipoprotein cholesterol levels. Valine, leucine, and total BCAA levels were weakly and positively correlated with LDL-C levels. Increased BCAA levels showed positive associations with MD. However, associations between BCAAs and elevated LDL-C levels were unclear. Furthermore, the associations between BCAA levels and MD regardless of fasting blood sugar (FBS) levels (high or low). Although valine, leucine, and total BCAA levels were weakly associated with elevated LDL-C levels in the high-FBS group, no such association was observed in the low-FBS group.

CONCLUSIONS

BCAAs might be associated with MD independently of the FBS level and might play an important role in lipid metabolism and dyslipidemia.

Isolation of a Capnophilic and Extended-Spectrum β-Lactamase-Producing Proteus mirabilis Strain from the Urine of an Octogenarian Male Patient with Acute Pyelonephritis

A capnophilic Gram-negative rod-shaped bacterium was recovered from the urine of an octogenarian male patient with acute pyelonephritis. The isolate was found to produce CTX-M-2-type extended-spectrum β-lactamase. Interestingly, the isolate failed to grow on modified Drigalski (BTB) and MacConkey agar media, even under CO₂-enriched atmosphere. Our analysis revealed that the pH-indicator dyes, bromothymol blue, and/or crystal violet that were incorporated into the agar media inhibited the growth of the isolate. Although routine identification methods using Vitek® 2 Compact systems were unsuccessful, the isolate was identified as Proteus mirabilis by 16S rRNA sequencing and MALDI-TOF MS analysis. The carbonic anhydrase (CA) region spanning approximately 2,000 bp upstream to 2,000 bp downstream, which is responsible for the CO₂ requirement, was not amplified, which could be attributed to the large-scale deletion or mutation of the DNA sequences containing the CA gene region. In fact, revertants with the ability to grow without CO₂ were not detected. However, a revertant that was capable of growing in both BTB and MacConkey agar was detected at frequencies less than 10^-9. Therefore, the genes responsible for the highly sensitive reactions of the isolate to pH indicator dyes is not likely to be linked to the CA genes.

Numerical study on spindle positioning using phase field method

A method of numerical simulation of cell division using phase fields is presented. The cell division plane is obtained as a result of the spindle position and orientation considered with the spatial distribution of the activated cortical force generators and the dividing cell shape. To exemplify the application of the proposed method, numerical simulations of the development of cysts and early embryos are performed. The numerical results demonstrate that the activated cortical force generators that are localized at the lateral cortices of the epithelial cells lead to the formation of a single central lumen. It is additionally shown that the linear distribution of the activated cortical force generators along the animal-vegetal axis of a spherical cell engenders a similar cell proliferation of the divided embryo generated by the 32 cell period in a sea cucumber.

Roles of aberrant hemichannel activities due to mutant connexin26 in the pathogenesis of KID syndrome

Germline missense mutations in GJB2 encoding connexin (Cx) 26 have been found in keratitis, ichthyosis and deafness (KID) syndrome. We explored the effects of three mouse Cx26 mutants (Cx26-G12R, -G45E and -D50N) corresponding to KID syndrome-causative human mutants on hemichannel activities leading to cell death and the expression of immune response-associated genes. We analyzed the 3D images of cells expressing wild-type (WT) or mutant Cx26 molecules to demonstrate clearly the intracellular localization of Cx26 mutants and hemichannel formation. High extracellular Ca²⁺ conditions lead to the closure of gap junction hemichannels in Cx26-G12R or Cx26-G45E expressing cells, resulting in prohibition of the Cx26 mutant-induced cell death. Fluorescent dye uptake assays revealed that cells with Cx26-D50N had aberrantly high hemichannel activities, which were abolished by a hemichannel blocker, carbenoxolone and 18α-Glycyrrhetinic acid. These results further support the idea that abnormal hemichannel activities play important roles in the pathogenesis of KID syndrome. Furthermore, we revealed that the expressions of IL15, CCL5, IL1A, IL23R and TLR5 are down-regulated in keratinocytes expressing Cx26-D50N, suggesting that immune deficiency in KID syndrome expressing Cx26-D50N might be associated not only with skin barrier defects, but also with the down-regulated expression of immune response-related genes.