Genome-wide association studies in the Japanese population identified genetic loci and target gene associated with epidermal turnover.

The epidermis is an essential organ for life by retaining water and as a protective barrier. The epidermis is maintained through metabolism, in which basal cells produced from epidermal stem cells differentiate into spinous cells, granular cells and corneocytes, and are finally shed from the epidermal surface. This is epidermal turnover, and with aging, there is a decline in epidermis function. Other factors that may affect epidermal turnover include ultraviolet damage and genetic factors. These genetic factors are of particular interest as little is known. Although recent skin-focused genome-wide association studies (GWAS) have been conducted, the genetic regions associated with epidermal turnover are almost uninvestigated. Therefore, we conducted a GWAS on epidermal turnover in the Japanese population, using the corneocyte area, which correlates to the rate of epidermal turnover, as an indicator. As a result, rs2278431 (p = 1.29 × 10-7 ) in 19q13.2 was associated with corneocyte size. Furthermore, eQTL analysis suggested that rs2278431 was related to the SPINT2 gene. In addition, SPINT2 knockdown studies using epidermal keratinocytes revealed that SPINT2 is involved in keratinocyte proliferation and in corneocyte size regulation in reconstructed epidermis. These results suggest that rs2278431 is involved in the expression of SPINT2 and affects epidermal turnover.

Clinical prediction rule for locomotive syndrome in older adults: A decision tree model.

BACKGROUND: No previous studies have proposed a clinical prediction rule that analyzes the factors related to the severity of locomotive syndrome. This study developed and assessed a clinical prediction rule for the severity of locomotive syndrome in older adults. METHODS: A total of 186 patients were assessed using the locomotive syndrome risk test. Classification and regression tree methodologies were used to develop the clinical prediction rule. This study developed three prediction models based on the severity of the locomotive syndrome, of which Model 3 assessed the most severe condition. The following potential predictive factors were measured and entered into each model; single-leg standing time, grip strength, preferred and maximum walking time, and timed up and go test. RESULTS: The single-leg standing test (≤59.4 or >59.4 s) was the best single discriminator for Model 1. Among those with a single-leg standing time >59.4 s, the next best predictor was grip strength (≤37.8 or >37.8 kg). In Model 2, the single-leg standing test was also the best single discriminator (≤12.6 or >12.6 s). Among those with a single-leg standing time ≤12.6, the next best predictor was TUG (≤7.9 or >7.9 s). Additionally, among those with a single-leg standing time >12.6, the next best predictor was single-leg standing time (≤55.3 or >55.3 s). In Model 3, predictive value in Model 2 was the best single discriminator (0 or 1). Among those with 1, the next best predictor was maximum walking time (≤3.75 or >3.75 s). The area under the receiver operating characteristic curves of Models 1, 2, and 3 were 0.737, 0.763, and 0.704, respectively. CONCLUSIONS: A clinical prediction rule was developed to assess the accuracy of the models. These results can be used to screen older adults for suspected locomotive syndrome.

Genome-wide association studies in Japanese women identified genetic loci associated with wrinkles and sagging.

Wrinkles and sagging are caused by various factors, such as ultraviolet rays; however, recent findings demonstrated that some individuals are genetically predisposed to these phenotypes of skin aging. The contribution of single nucleotide polymorphisms (SNPs) to the development of wrinkles and sagging has been demonstrated in genome-wide association studies (GWAS). However, these findings were mainly obtained from European and Chinese populations. Limited information is currently available on the involvement of SNPs in the development of wrinkles and sagging in a Japanese population. Therefore, we herein performed GWAS on wrinkles at the outer corners of the eyes and nasolabial folds in 1041 Japanese women. The results obtained revealed that 5 SNPs (19p13.2: rs2303098 (p = 3.39 × 10-8 ), rs56391955 (p = 3.39 × 10-8 ), rs67560822 (p = 3.50 × 10-8 ), rs889126 (p = 3.78 × 10-8 ), rs57490083 (p = 3.99 × 10-8 )) located within the COL5A3 gene associated with wrinkles at the outer corners of the eyes. Regarding nasolabial folds, 8q24.11 (rs4876369; p = 1.05 × 10-7 , rs6980503; p = 1.25 × 10-7 , rs61027543; p = 1.25 × 10-7 , rs16889363; p = 1.38 × 10-7 ) was suggested to be associated with RAD21 gene expression. These SNPs have not been reported in other populations, and were first found in Japanese women population. These SNPs may be used as markers to examine the genetic predisposition of individuals to wrinkles and sagging.

Identification of mitochondrial genetic variants associated with human corneocyte size in Japanese women.

Mitochondria have their own DNA (mtDNA). Genetic variants are likely to accumulate in mtDNA, and its base substitution rate is known to be very fast, 10-20 times faster than that of nuclear DNA. For this reason, mtSNPs (mitochondrial genome single nucleotide polymorphisms) are frequently detected in mtDNA. Several thousands of copies of mtDNA are considered to be present in a cell, and variants that have occurred in mtDNA are expected to markedly affect the intracellular energy production system and ROS (reactive oxygen species) kinetics. Therefore, recently, mtSNPs have come to be considered very important as a determinant of the individual constitution such as the life-span and disease susceptibility. In this study, we searched for mtSNPs that affect the individual corneocyte size using samples from 358 Japanese women. As a result, mtSNPs 10609C and 12406A were found to be significantly related to the corneocyte size in the outermost layer of the epidermis. There have been a large number of reports concerning the association between mtSNPs and individual constitution, but little evaluation of their relationships with epidermal properties has been made. The results of the present study first suggested that mtSNPs may affect the epidermal properties in Japanese women.

Melanin accumulation in dermal stem cells deteriorates their exosome-mediated skin basement membrane construction in solar lentigo.

Solar lentigo (SL) is a hyperpigmented macule that occurs in sun-exposed areas and is characterized by the accumulation of melanin pigment in the epidermis. On the contrary, melanin-incorporated macrophages have also been identified in the dermis, which is thought to be caused by melanin transfer due to disruption of the basement membrane, but the detailed mechanism remains unclear. In this study, we analysed SL lesions by pathological methods and examined the mechanism of melanin accumulation in the dermis using cultured skin models in vitro. First, we observed a significant decrease in type IV collagen (COL4), a major component of the basement membrane, in SL lesions. The basement membrane is known to be formed by the interaction of keratinocytes and dermal cells. Therefore, we constructed skin models containing fibroblasts or dermal stem cells and examined their effects on basement membrane formation. The results showed a markedly enhanced production of COL4 mediated by dermal stem cell-derived exosomes. The analysis of melanin localization in the SL dermis revealed that CD163-positive macrophages and CD271-positive dermal stem cells both took up melanin pigment. Exosomes of dermal stem cells incorporating melanosomes were less effective in promoting COL4 expression. These findings suggest that while the promotion of COL4 production in keratinocytes by dermal stem cell-derived exosomes is important for maintaining basement membrane homeostasis, this mechanism is disrupted in SL lesions, leading to chronic melanin accumulation in the dermis.

Developing a Clinical Prediction Rule for Gait Independence at Discharge in Patients with Stroke: A Decision-Tree Algorithm Analysis.

OBJECTIVES: To develop a clinical prediction rule (CPR) for gait independence at discharge in patients with stroke, using the decision-tree algorithm and to investigate the usefulness of CPR at admission to the rehabilitation ward. MATERIALS AND METHODS: We included 181 subjects with stroke during the postacute phase. The Chi-squared automatic interaction detection analysis method with 10-fold cross-validation was used to develop two CPRs; CPR 1 using easily obtainable data available at admission; CPR 2 using easily obtainable data available 1 month after admission, for prediction of gait independence at discharge. RESULTS: The degree of independence of toileting was extracted as a first node in the development of two CPRs to predict gait independence at discharge. CPR 1 included the presence of delirium. CPR 2 included problem-solving abilities. The accuracy and area under the curve of CPR 1 were 84.5% and 0.911, respectively; those of CPR 2 were 89.0% and 0.958, respectively. CONCLUSIONS: Toileting independence is a key factor in predicting the gait independence for the discharge of patients with stroke during the postacute phase. Early intervention, during the acute phase, for delirium and cognitive decline, as well as for toileting, increases the possibility of gait independence at discharge.

Search for genetic loci involved in the constitution and skin type of a Japanese women using a genome-wide association study.

The constitution and skin type of individuals are influenced by various factors. Recently, the influence of genetic predispositions on these has been emphasized. To date, genome-wide association studies (GWAS) have shown several single nucleotide polymorphisms (SNPs) that affect individual's constitution and skin type. However, these studies have mainly focused on the Caucasian population, and only a few association analyses with the constitution and skin type of individuals involving a Japanese population have been conducted. In this study, we conducted a GWAS analysis of 9 phenotypes regarding the constitution or skin type of 1108 Japanese women based on a questionnaire. As a result, in addition to SNPs known to be involved in phenotypes in the past, we discovered new SNPs and genetic regions related to darkness of pigmented spots, skin flushing, frequency of rough skin and responsiveness to cosmetics.

Senescent cell removal via JAG1-NOTCH1 signalling in the epidermis.

Emerging evidence has pointed to the noxious effects of senescent cells in various tissues, and senescent cells in the epidermis are known to accumulate with age. We hypothesized that there is a mechanism by which senescent cells in the epidermis are preferentially removed and that the function of such removal mechanism declines as age increases. In this study, we investigated whether Notch signalling is involved in such senescent cell removal. We found that Notch1 receptor was expressed more highly in p16INK4a-positive senescent cells than in surrounding cells in human epidermis both in young and old subjects. On the other hand, the expression of its ligand JAG1 was decreased in the epidermis of aged subjects. When normal epidermal cells and UVB-irradiated senescent cells were mixed and three-dimensional reconstructed epidermis was developed in vitro, the senescent cells were preferentially removed from the basal layer and located in the upper layer. We also found that the depletion of senescent cells from the basal layer was suppressed by JAG1 knockdown in normal cells or using a Notch signalling inhibitor. From these results, Notch signalling may be involved in senescent cell removal in the epidermis and the age-related decrease of JAG1 expression in the basal layer may lead to accumulation of senescent cells owing to reduced activation of Notch signalling.

Establishment of Three Types of Immortalized Human Skin Stem Cell Lines Derived from the Single Donor.

Currently, human-skin derived cell culture is a basic technique essential for dermatological research, cellular engineering research, drug development, and cosmetic development. But the number of donors is limited, and primary cell function reduces through cell passage. In particular, since adult stem cells are present in a small amount in living tissues, it has been difficult to obtain a large amount of stem cells and to stably culture them. In this study, skin derived cells were isolated from the epidermis, dermis, and adipose tissue collected from single donor, and immortalization was induced through gene transfer. Subsequently, cell lines that could be used as stem cell models were selected using the differentiation potential and the expression of stem cell markers as indices, and it was confirmed that these could be stably cultured. The immortalized cell lines established in this study have the potential to be applied not only to basic dermatological research but also to a wide range of fields such as drug screening and cell engineering.

Comparison of gene expression and activation of transcription factors in organoid-derived monolayer intestinal epithelial cells and organoids.

Intestinal organoids better represent in vivo intestinal properties than conventionally used established cell lines in vitro. However, they are maintained in three-dimensional culture conditions that may be accompanied by handling complexities. We characterized the properties of human organoid-derived two-dimensionally cultured intestinal epithelial cells (IECs) compared with those of their parental organoids. We found that the expression of several intestinal markers and functional genes were indistinguishable between monolayer IECs and organoids. We further confirmed that their specific ligands equally activate intestinal ligand-activated transcriptional regulators in a dose-dependent manner. The results suggest that culture conditions do not significantly influence the fundamental properties of monolayer IECs originating from organoids, at least from the perspective of gene expression regulation. This will enable their use as novel biological tools to investigate the physiological functions of the human intestine.

A clinical prediction rule for predicting a delay in quality of life recovery at 1 month after total knee arthroplasty: A decision tree model.

BACKGROUND: There is no clinical prediction rule for predicting the prognosis of quality of life after total knee arthroplasty and for assessing its accuracy. The study aimed to develop and assess a clinical prediction rule to predict decline in quality of life at 1 month after total knee arthroplasty. METHODS: This study included 116 patients with total knee arthroplasty in Japan. Potential predictors such as sociodemographic factors, medical information, and motor functions were measured. Quality of life was measured using the Japanese Knee Osteoarthritis Measure at 1 day before surgery and 1 month after total knee arthroplasty. The classification and regression tree methodology was used for developing a clinical prediction rule. RESULTS: The Japanese Knee Osteoarthritis Measure score pre-total knee arthroplasty (≦34.0 or >34.0) was the best single discriminator. Among those with the Japanese Knee Osteoarthritis Measure score pre-total knee arthroplasty ≦34.0, the next best predictor was knee flexor muscle strength on the affected side (≦0.45 or >0.45 N m/kg). Among those with knee flexor muscle strength on the affected side >0.45, the next predictor was knee flexion range of motion on the affected side (≦132.5°or >132.5°). The area under the receiver operating characteristic curves of the model was 0.805 (95% confidence interval, 0.701-0.909). CONCLUSIONS: In this study, 4 variables were selected as the significant predictor. However, the results of knee flexor muscle strength and knee flexion range of motion were paradoxical. This result suggests that it should be careful to perform surgery to the patients with good preoperative knee function. The clinical prediction rule was developed for predicting quality of life decline 1 month after total knee arthroplasty, and the accuracy was moderate. This clinical prediction rule can be used for screening of patients with total knee arthroplasty.

Clinical Features for Identifying the Possibility of Toileting Independence after Convalescent Inpatient Rehabilitation in Severe Stroke Patients: A Decision Tree Analysis Based on a Nationwide Japan Rehabilitation Database.

BACKGROUND AND PURPOSE: In severe stroke patients, considerable concern should be given to toileting activity in rehabilitative support. Recently, the application of artificial intelligence, including machine learning (ML), has expanded into the stroke medical field, which could clarify the factors affecting toileting independence in severe stroke patients. This study aimed to identify the factors affecting toileting independence in severe stroke patients using ML. METHODS: We used the Japan Rehabilitation Database from 2005 to 2015 to investigate data from 2292 severe stroke patients. We performed the chi-squared automatic interaction detection (CHAID) algorithm with various explanatory variables. RESULTS: The CHAID model identified modified Rankin scale (mRS) score as the first discriminator. Among those with an mRS score ≤4, the next discriminator was age (score ≤72, 73-80, or >80). Among those with an mRS score > 4, the next discriminator was also age (score ≤57, 58-72, 73-80, or >80). Interestingly, some patients achieved toileting independence, although this study focused on severe stroke patients. In branches based on age, the percentage of the patients who achieved toileting independence at discharge decreased progressively with age. CONCLUSION: We identified the influential factors, including reference values, for achieving toileting independence in convalescent severe stroke patients.

Comparison of Supervised Machine Learning Algorithms for Classifying of Home Discharge Possibility in Convalescent Stroke Patients: A Secondary Analysis.

OBJECTIVES: Classifying the possibility of home discharge is important during stroke rehabilitation to support decision-making. There have been several studies on supervised machine learning algorithms, but only a few have compared the performance of different algorithms based on the same dataset for the classification of home discharge possibility. Therefore, we aimed to evaluate five supervised machine learning algorithms for the classification of home discharge possibility in stroke patients. MATERIALS AND METHODS: This was a secondary analysis based on the data of 481 stroke patients from the database of our institution. Five models developed by supervised machine learning algorithms, including decision tree (DT), linear discriminant analysis (LDA), k-nearest neighbors (k-NN), support vector machine (SVM), and random forest (RF) were compared by constructing a classification system based on the same dataset. Several parameters including classification accuracy, area under the curve (AUC), and F1 score (a weighted average of precision and recall) were used for model evaluation. RESULTS: The k-NN model had the best classification accuracy (84.0%) with a moderate AUC (0.88) and F1 score (87.8). The SVM model also showed high classification accuracy (82.6%) along with the highest AUC (0.91), sensitivity (94.4), negative predictive value (87.5), and negative likelihood ratio (0.088). The DT, LDA, and RF models had high classification accuracies (≥ 79.9%) with moderate AUCs (≥ 0.84) and F1 scores (≥ 83.8). CONCLUSIONS: Regarding model performance, the k-NN and SVM seemed the best candidate algorithms for classifying the possibility of home discharge in stroke patients.

Decision Tree Algorithm Identifies Stroke Patients Likely Discharge Home After Rehabilitation Using Functional and Environmental Predictors.

BACKGROUND AND PURPOSE: The importance of environmental factors for stroke patients to achieve home discharge was not scientifically proven. There are limited studies on the application of the decision tree algorithm with various functional and environmental variables to identify stroke patients with a high possibility of home discharge. The present study aimed to identify the factors, including functional and environmental factors, affecting home discharge after stroke inpatient rehabilitation using the machine learning method. METHOD: This was a cohort study on data from the maintained database of all patients with stroke who were admitted to the convalescence rehabilitation ward of our facility. In total, 1125 stroke patients were investigated. We developed three classification and regression tree (CART) models to identify the possibility of home discharge after inpatient rehabilitation. RESULTS: Among three models, CART model incorporating basic information, functional factor, and environmental factor variables achieved the highest accuracy for identification of home discharge. This model identified FIM dressing of the upper body (score of ≤2 or >2) as the first single discriminator for home discharge. Performing house renovation was associated with a high possibility of home discharge even in patients with stroke who had a poor FIM score in the ability to dress the upper body (≤2) at admission into the convalescence rehabilitation ward. Interestingly, many patients who performed house renovation have achieved home discharge regardless of the degree of lower limb paralysis. CONCLUSION: We identified the influential factors for realizing home discharge using the decision tree algorithm, including environmental factors, in patients with convalescent stroke.

Healthcare-seeking behavior and awareness of physical therapy among Japanese residents in Thailand: a descriptive study.

[Purpose] This descriptive study examined healthcare-seeking behavior and awareness of physical therapy among Japanese residents of different age groups in Thailand. [Participants and Methods] The study included 145 Japanese residents in Thailand. An online questionnaire was used to collect data on the participants' sociodemographic characteristics, healthcare-seeking behavior, and awareness of physical therapy. Participants were categorized into three groups based on age, such as young adults, middle-aged adults, and older adults. The χ2 test and Fisher's exact test were used in the data analysis. [Results] The results showed that compared with the older groups, the youngest group was more likely to visit pharmacies, physical therapy clinics, osteopathic clinics, and Thai massage shops to receive healthcare services for injuries or diseases. The participants learned about healthcare services in Thailand through word-of-mouth. Additionally, more than 50% of all participants knew about physical therapy. [Conclusion] There are some differences in health-seeking behavior and awareness of physical therapy among the groups. The youngest group visited physical therapy clinics and 50% of all participants knew about physical therapy.

Minimal clinically important difference for the Fugl-Meyer assessment of the upper extremity in convalescent stroke patients with moderate to severe hemiparesis.

[Purpose] To estimate the minimal clinically important difference for the Fugl-Meyer assessment of the upper extremity by using anchor-based methods in stroke patients with moderate to severe hemiparesis. [Participants and Methods] Fourteen patients who were hospitalized in a convalescent phase rehabilitation ward were included in this study. Fugl-Meyer assessment of the upper extremity was used to assess the impairment prior to intervention and at follow-up (six weeks later). Participants were asked to evaluate the degree of improvement of paresis of the upper extremity using the global rating of change scale at follow-up. The mean change in Fugl-Meyer assessment scores in the group of patients who answered "a little better, meaningful in daily life" in the global rating of change scale was considered as the minimal clinically important difference. [Results] The mean post-onset period of participants for analysis was 49.4 days. The minimal clinically important difference of the Fugl-Meyer assessment scores were 12.4 (upper extremity), 5.6 (upper arm), and 4.9 (wrist/hand). [Conclusion] A score of 12.4 in the Fugl-Meyer assessment of the upper extremity is likely to be perceived as meaningful in stroke patients with moderate to severe hemiparesis.

Development of 3D imaging technique of reconstructed human epidermis with immortalized human epidermal cell line.

The epidermis, the outermost layer of the skin, retains moisture and functions as a physical barrier against the external environment. Epidermal cells are continuously replaced by turnover, and thus to understand in detail the dynamic cellular events in the epidermis, techniques to observe live tissues in 3D are required. Here, we established a live 3D imaging technique for epidermis models. We first obtained immortalized human epidermal cell lines which have a normal differentiation capacity and fluorescence-labelled cytoplasm or nuclei. The reconstituted 3D epidermis was prepared with these lines. Using this culture system, we were able to observe the structure of the reconstituted epidermis live in 3D, which was similar to an in vivo epidermis, and evaluate the effect of a skin irritant. This technique may be useful for dermatological science and drug development.

Lower garment-lifting postural control characteristics during toilet-related activities in healthy individuals and a post-stroke hemiplegic patient undergoing rehabilitation.

[Purpose] This study compared lower garment-lifting postural control characteristics during toilet-related activities between healthy participants and a post-stroke patient, and studied changes in the stroke patient's characteristics during rehabilitation. [Participants and Methods] Six healthy individuals and one stroke participant with right hemiparesis were asked to lift a pair of pants with the left arm while on the toilet. During the process, we measured the mean percentage of body weight (%BW) on each leg and the foot center of pressure (COP) using portable force plates. Measurements were conducted twice for the stroke participant during rehabilitation. [Results] In healthy participants, the %BW and respective COP indices for both legs were not different during lifting, but the COP sway velocity and excursion were greater in the anterior-posterior (AP) than the lateral axis in both legs. In the stroke participant, no marked change was seen in the high %BW of the non-paretic leg while lifting during rehabilitation, but both legs' COP positional asymmetry improved on the AP axis and the COP sway velocity and excursion of the non-paretic leg increased. [Conclusion] Facilitating selective COP mobility on the AP axis of the non-paretic leg during lower garment lifting could become an effective intervention for stroke patients.

Inhibitory effect of Phalaenopsis orchid extract on WNT1-induced immature melanocyte precursor differentiation in a novel in vitro solar lentigo model.

Recently, it has been reported that increased expression of WNT1 accelerates the differentiation of melanocyte stem cells (McSCs) in solar lentigines (SLs), hyperpigmented maculae commonly seen on sun-exposed areas of the skin. In this study, to establish an in vitro SL model, human epidermal squamous carcinoma cell line HSC-1, which expresses higher levels of WNT1 than normal human epidermal keratinocytes, was co-cultured with early passage normal human epidermal melanocytes (NHEMs) as an in vitro McSC model. As a result, mRNA expression levels of melanocyte differentiation-related genes MITF and TYR in NHEMs were significantly increased by co-culturing with HSC-1 cells. Furthermore, Phalaenopsis orchid extract (Phex) inhibited McSCs differentiation by suppressing WNT1 expression via down-regulation of DLX2, a transcriptional activator of WNT1, in HSC-1 cells. Therefore, our finding suggested that extracts such as Phex, which suppresses WNT1 expression, may be useful as a novel treatment of SLs.