Three-dimensional imaging evaluation of facial swelling after orthognathic surgery with compression and Kinesio taping therapy: a randomized clinical trial

Background

Postoperative swelling is a common complication of orthognathic surgery. The authors used three-dimensional (3D) image analysis and body surface temperature to determine the effects of compression taping (CT) and Kinesio taping (KT) by the epidermis, dermis, and fascia method (EDF-KT) on postoperative swelling.

Materials and methods

The authors conducted a prospective, parallel-group, randomized controlled trial. Among the 162 patients diagnosed with jaw deformity and who underwent orthognathic surgery from August 2020 to October 2022, 105 patients (men: 36, women: 69, mean age: 28.27±8.92) underwent Le Fort type I + sagittal split ramus osteotomy (SSRO) or SSRO and were included in this study. Patients were randomly divided into three groups: EDF-KT group (n=31), CT group (n=41), and no tape group (control group, n=30). All taping was performed immediately postoperatively and removed on postoperative day (POD) 5. Three-dimensional images of the participants' faces were obtained preoperatively and at PODs 3, 7, 30, and 90 using a hand-held 3D imaging system and infrared thermography.

Results

No significant difference was observed in postoperative swelling and postoperative body surface temperature between the groups at each time point. The CT group showed a trend towards reduced swelling on PODs 3 and 7 and a trend toward residual swelling on POD 90. The EDF-KT group showed a trend towards an increase in postoperative body surface temperature.

Conclusion

CT taping may not be appropriate for postoperative swelling control, suggesting that EDF-KT may affect body surface temperature. Further validation of the efficacy of KT for jaw deformities is needed.

Fluctuation of lysosomal protein degradation in neural stem cells of the postnatal mouse brain

Lysosomes are intracellular organelles responsible for degrading diverse macromolecules delivered from several pathways, including the endo-lysosomal and autophagic pathways. Recent reports have suggested that lysosomes are essential for regulating neural stem cells in developing, adult and aged brains. However, the activity of these lysosomes has yet to be monitored in these brain tissues. Here, we report the development of a new probe to measure lysosomal protein degradation in brain tissue by immunostaining. Our results indicate that lysosomal protein degradation fluctuates in neural stem cells of the hippocampal dentate gyrus, depending on age and brain disorders. Neural stem cells increase their lysosomal activity during hippocampal development in the dentate gyrus, but aging and aging-related disease reduce lysosomal activity. In addition, physical exercise increases lysosomal activity in neural stem cells and astrocytes in the dentate gyrus. We therefore propose that three different stages of lysosomal activity exist: the state of increase during development, the stable state during adulthood and the state of reduction due to damage caused by either age or disease.

Novel frameshift variant of WNT10A in a Japanese patient with hypodontia

Congenital tooth agenesis is caused by the impairment of crucial genes related to tooth development, such as Wnt signaling pathway genes. Here, we investigated the genetic causes of sporadic congenital tooth agenesis. Exome sequencing, followed by Sanger sequencing, identified a novel single-nucleotide deletion in WNT10A (NC_000002.12(NM_025216.3):c.802del), which was not found in the healthy parents of the patient. Thus, we concluded that the variant was the genetic cause of the patient's agenesis.

Impact of the lateral skeletal stability following bilateral sagittal split ramus osteotomy for mandibular asymmetry

This study evaluated the stability of bilateral sagittal split ramus osteotomy (BSSRO) associated with positional plagiocephaly and temporal and masseter muscles using posteroanterior cephalogram analysis and three-dimensional computed tomography (3D-CT). This retrospective cohort study included 31 patients who underwent BSSRO for mandibular asymmetry. The cranial vault asymmetry index (CVAI) and the cephalic index were used as indicators of positional plagiocephaly. The distance from the vertical reference line to the menton (Me) was measured on posteroanterior cephalograms immediately and 1 year after surgery, and postoperative stability was assessed. Temporal and masseter muscles were constructed from 3D-CT data and their volumes were measured. Simple regression analysis showed a significant correlation between postoperative changes in the vertical reference line to the Me and the CVAI (R = 0.56, p = 0.001), the amount of surgical movement in the vertical reference line to the Me (R = 0.41, p = 0.023), and the variable temporal muscle volume (R = 0.27, p = 0.028). There was no significant correlation between postoperative changes in the vertical reference line to the Me and the cephalic index (R = 0.093, p = 0.62) and variable masseter muscle volume (R = 0.16, p = 0.38). According to multivariate analysis, CVAI (p = 0.003) and amount of surgical movement in the vertical reference line to the Me (p = 0.014) were significant predictors of postoperative change in the vertical reference line to the Me. Positional plagiocephaly and amount of surgical movement influence lateral skeletal stability following BSSRO for mandibular asymmetry.

Factors affecting progressive facial swelling immediately after orthognathic surgery: A retrospective cohort study

The aim of this study was to identify clinical factors associated with progressive facial swelling after orthognathic surgery. Patients diagnosed with jaw deformities and undergoing orthognathic surgery were retrospectively evaluated, and those with surgical site infection, Le Fort I osteotomy, or genioplasty only were excluded. Facial swelling volume was calculated by comparing facial volume preoperatively and three days postoperatively using 3D images and image analysis software (VECTRA H2). FXIII was measured within three days after surgery in only patients with unexplained postoperative bleeding or hematoma. The correlation between facial swelling volume and clinical factors was statistically analyzed. Facial swelling volume was examined in 78 patients. Univariate analysis showed a significant difference between facial swelling volume (mean = 41.6 cm3) and operation time (mean = 209.3 min, r = 0.283, p = 0.012), ΔHb level (mean = 1.18 g/dL, r = 0.235, p = 0.039), as well as decreased factor XIII activity (mean = 75.3%, p = 0.012). Multivariate analysis showed a significant difference between facial swelling volume and FXIII deficiency (standard error = 6.44, p = 0.031).Progressive facial swelling immediately after orthognathic surgery may be due to factor XIII deficiency.

Hematopoietic cell-derived IL-15 supports NK cell development in scattered and clustered localization within the bone marrow

Natural killer (NK) cells are innate immune cells critical for protective immune responses against infection and cancer. Although NK cells differentiate in the bone marrow (BM) in an interleukin-15 (IL-15)-dependent manner, the cellular source of IL-15 remains elusive. Using NK cell reporter mice, we show that NK cells are localized in the BM in scattered and clustered manners. NK cell clusters overlap with monocyte and dendritic cell accumulations, whereas scattered NK cells require CXCR4 signaling. Using cell-specific IL-15-deficient mice, we show that hematopoietic cells, but not stromal cells, support NK cell development in the BM through IL-15. In particular, IL-15 produced by monocytes and dendritic cells appears to contribute to NK cell development. These results demonstrate that hematopoietic cells are the IL-15 niche for NK cell development in the BM and that BM NK cells are present in scattered and clustered compartments by different mechanisms, suggesting their distinct functions in the immune response.

Liver type 1 innate lymphoid cells lacking IL-7 receptor are a native killer cell subset fostered by parenchymal niches

Group 1 innate lymphoid cells (G1-ILCs), including circulating natural killer (NK) cells and tissue-resident type 1 ILCs (ILC1s), are innate immune sentinels critical for responses against infection and cancer. In contrast to relatively uniform NK cells through the body, diverse ILC1 subsets have been characterized across and within tissues in mice, but their developmental and functional heterogeneity remain unsolved. Here, using multimodal in vivo approaches including fate-mapping and targeting of the interleukin 15 (IL-15)-producing microenvironment, we demonstrate that liver parenchymal niches support the development of a cytotoxic ILC1 subset lacking IL-7 receptor (7 R^- ILC1s). During ontogeny, fetal liver (FL) G1-ILCs arise perivascularly and then differentiate into 7 R^- ILC1s within sinusoids. Hepatocyte-derived IL-15 supports parenchymal development of FL G1-ILCs to maintain adult pool of 7 R^- ILC1s. IL-7R⁺ (7R⁺) ILC1s in the liver, candidate precursors for 7 R^- ILC1s, are not essential for 7 R^- ILC1 development in physiological conditions. Functionally, 7 R^- ILC1s exhibit killing activity at steady state through granzyme B expression, which is underpinned by constitutive mTOR activity, unlike NK cells with exogenous stimulation-dependent cytotoxicity. Our study reveals the unique ontogeny and functions of liver-specific ILC1s, providing a detailed interpretation of ILC1 heterogeneity.

Neutrophil S100A9 supports M2 macrophage niche formation in granulomas

Mycobacterium infection gives rise to granulomas predominantly composed of inflammatory M1-like macrophages, with bacteria-permissive M2 macrophages also detected in deep granulomas. Our histological analysis of Mycobacterium bovis bacillus Calmette-Guerin-elicited granulomas in guinea pigs revealed that S100A9-expressing neutrophils bordered a unique M2 niche within the inner circle of concentrically multilayered granulomas. We evaluated the effect of S100A9 on macrophage M2 polarization based on guinea pig studies. S100A9-deficient mouse neutrophils abrogated M2 polarization, which was critically dependent on COX-2 signaling in neutrophils. Mechanistic evidence suggested that nuclear S100A9 interacts with C/EBPβ, which cooperatively activates the Cox-2 promoter and amplifies prostaglandin E2 production, followed by M2 polarization in proximal macrophages. Because the M2 populations in guinea pig granulomas were abolished via treatment with celecoxib, a selective COX-2 inhibitor, we propose the S100A9/Cox-2 axis as a major pathway driving M2 niche formation in granulomas.

A circulating subset of iNKT cells mediates antitumor and antiviral immunity

Invariant natural killer T (iNKT) cells are a group of innate-like T lymphocytes that recognize lipid antigens. They are supposed to be tissue resident and important for systemic and local immune regulation. To investigate the heterogeneity of iNKT cells, we recharacterized iNKT cells in the thymus and peripheral tissues. iNKT cells in the thymus were divided into three subpopulations by the expression of the natural killer cell receptor CD244 and the chemokine receptor CXCR6 and designated as C0 (CD244 − CXCR6 − ), C1 (CD244 − CXCR6 + ), or C2 (CD244 + CXCR6 + ) iNKT cells. The development and maturation of C2 iNKT cells from C0 iNKT cells strictly depended on IL-15 produced by thymic epithelial cells. C2 iNKT cells expressed high levels of IFN-γ and granzymes and exhibited more NK cell–like features, whereas C1 iNKT cells showed more T cell–like characteristics. C2 iNKT cells were influenced by the microbiome and aging and suppressed the expression of the autoimmune regulator AIRE in the thymus. In peripheral tissues, C2 iNKT cells were circulating that were distinct from conventional tissue-resident C1 iNKT cells. Functionally, C2 iNKT cells protected mice from the tumor metastasis of melanoma cells by enhancing antitumor immunity and promoted antiviral immune responses against influenza virus infection. Furthermore, we identified human CD244 + CXCR6 + iNKT cells with high cytotoxic properties as a counterpart of mouse C2 iNKT cells. Thus, this study reveals a circulating subset of iNKT cells with NK cell–like properties distinct from conventional tissue-resident iNKT cells.

PKR and TLR3 trigger distinct signals that coordinate the induction of antiviral apoptosis

RIG-I-like receptors (RLRs), protein kinase R (PKR), and endosomal Toll-like receptor 3 (TLR3) sense viral non-self RNA and are involved in cell fate determination. However, the mechanisms by which intracellular RNA induces apoptosis, particularly the role of each RNA sensor, remain unclear. We performed cytoplasmic injections of different types of RNA and elucidated the molecular mechanisms underlying viral dsRNA-induced apoptosis. The results obtained revealed that short 5'-triphosphate dsRNA, the sole ligand of RIG-I, induced slow apoptosis in a fraction of cells depending on IRF-3 transcriptional activity and IFN-I production. However, intracellular long dsRNA was sensed by PKR and TLR3, which activate distinct signals, and synergistically induced rapid apoptosis. PKR essentially induced translational arrest, resulting in reduced levels of cellular FLICE-like inhibitory protein and functioned in the TLR3/TRIF-dependent activation of caspase 8. The present results demonstrated that PKR and TLR3 were both essential for inducing the viral RNA-mediated apoptosis of infected cells and the arrest of viral production.

Oral hygiene status and factors related to oral health in hospitalized patients with schizophrenia

OBJECTIVE

This study aimed to elucidate the oral hygiene status and the factors associated with poor oral hygiene among patients with schizophrenia.

METHODS

The relationships of oral hygiene status (calculus index [CI], debris index [DI]), the mean number of decayed-missing-filled teeth (mean DMFT), and Revised Oral Assessment Guide (ROAG) with related factors (hospitalization, chlorpromazine equivalents [CPZE], age, Barthel Index [BI], frequency of cleaning teeth, and self-oral hygiene ability) among 249 hospitalized schizophrenic patients were investigated.

RESULTS

The results for oral hygiene status were as follows: median (range); CI 0.5 (0-6.0), DI 1.7 (0-6.0), ROAG 10.0 (7.0-15.0); and mean DMFT 21.7±7.3. The average CPZE was 524.4±353.6 mg (mean ± SD), and the BI was 76.4±30.7. There was a negative correlation between BI and DI (r = -0.34) and a positive correlation between age and mean DMFT (r=0.57). Male patients tended to have worse oral conditions (ROAG) than females. The least-squares multiple regression analysis revealed that BI for DI, age for mean DMFT, sex for ROAG, and self-oral hygiene ability for CI, DI, and mean DMFT were factors related to oral health status.

CONCLUSION

Patients with schizophrenia tended to have poor oral hygiene. BI, being male, and low activities of daily living were associated with poor oral hygiene. Furthermore, advanced age was associated with an increased risk of dental caries.

BDNF controls GABAAR trafficking and related cognitive processes via autophagic regulation of p62

Reduced brain-derived neurotrophic factor (BDNF) and gamma-aminobutyric acid (GABA) neurotransmission co-occur in brain conditions (depression, schizophrenia and age-related disorders) and are associated with symptomatology. Rodent studies show they are causally linked, suggesting the presence of biological pathways mediating this link. Here we first show that reduced BDNF and GABA also co-occur with attenuated autophagy in human depression. Using mice, we then show that reducing Bdnf levels (Bdnf^+/-) leads to upregulated sequestosome-1/p62, a key autophagy-associated adaptor protein, whose levels are inversely correlated with autophagic activity. Reduced Bdnf levels also caused reduced surface presentation of α5 subunit-containing GABA_A receptor (α5-GABA_AR) in prefrontal cortex (PFC) pyramidal neurons. Reducing p62 gene dosage restored α5-GABA_AR surface expression and rescued PFC-relevant behavioral deficits of Bdnf^+/- mice, including cognitive inflexibility and reduced sensorimotor gating. Increasing p62 levels was sufficient to recreate the molecular and behavioral profiles of Bdnf^+/- mice. Collectively, the data reveal a novel mechanism by which deficient BDNF leads to targeted reduced GABAergic signaling through autophagic dysregulation of p62, potentially underlying cognitive impairment across brain conditions.

Discovery of anti-inflammatory physiological peptides that promote tissue repair by reinforcing epithelial barrier formation

Epithelial barriers that prevent dehydration and pathogen invasion are established by tight junctions (TJs), and their disruption leads to various inflammatory diseases and tissue destruction. However, a therapeutic strategy to overcome TJ disruption in diseases has not been established because of the lack of clinically applicable TJ-inducing molecules. Here, we found TJ-inducing peptides (JIPs) in mice and humans that corresponded to 35 to 42 residue peptides of the C terminus of alpha 1-antitrypsin (A1AT), an acute-phase anti-inflammatory protein. JIPs were inserted into the plasma membrane of epithelial cells, which promoted TJ formation by directly activating the heterotrimeric G protein G13. In a mouse intestinal epithelial injury model established by dextran sodium sulfate, mouse or human JIP administration restored TJ integrity and strongly prevented colitis. Our study has revealed TJ-inducing anti-inflammatory physiological peptides that play a critical role in tissue repair and proposes a previously unidentified therapeutic strategy for TJ-disrupted diseases.

Impact of COVID-19 pandemic on oral and maxillofacial surgery in Japan: A report from a questionnaire survey during the different phases of the pandemic

COVID-19 pandemic has provided a new challenge to healthcare systems and medical care providers. In the current study, we describe the challenges faced and actions taken to provide optimum healthcare in Japan during the COVID-19 pandemic based on the results of a questionnaire survey that was conducted by oral and maxillofacial surgeons. A total of 24 Japanese institutions participated in the study. The first survey was conducted between June 22, 2020 and June 26, 2020, and the second survey was conducted between October 23, 2020 and November 8, 2020. The questionnaire focused on the practical situation in the respondent's hospital, personal protective equipment (PPE) availability, and what alterations had occurred compared to the situation before the COVID-19 pandemic. The commonest reported duration of restrictions to the outpatient clinic was 1–2 months. All of the institutions had lifted their restrictions on outpatient services by September 2020. Surgical procedures in the operating room were restricted in 74% of hospitals in the first wave of the pandemic; however, 88% lifted their restrictions and restarted their regular surgical services by November 2020. Although, non-urgent or elective procedures were delayed, surgeries for malignant tumors, maxillofacial infections, and trauma were performed at almost all hospitals during the pandemic. Health care institutions will require a new approach to maintain patient volume and recover from the pandemic. Going forward, it is also necessary to minimize the risk of exposure and transmission to health care personnel as well as patients.

Vasculature-driven stem cell population coordinates tissue scaling in dynamic organs

Stem cell (SC) proliferation and differentiation organize tissue homeostasis. However, how SCs regulate coordinate tissue scaling in dynamic organs remain unknown. Here, we delineate SC regulations in dynamic skin. We found that interfollicular epidermal SCs (IFESCs) shape basal epidermal proliferating clusters (EPCs) in expanding abdominal epidermis of pregnant mice and proliferating plantar epidermis. EPCs consist of IFESC-derived Tbx3+-basal cells (Tbx3+-BCs) and their neighboring cells where Adam8-extracellular signal-regulated kinase signaling is activated. Clonal lineage tracing revealed that Tbx3+-BC clones emerge in the abdominal epidermis during pregnancy, followed by differentiation after parturition. In the plantar epidermis, Tbx3+-BCs are sustained as long-lived SCs to maintain EPCs invariably. We showed that Tbx3+-BCs are vasculature-dependent IFESCs and identified mechanical stretch as an external cue for the vasculature-driven EPC formation. Our results uncover vasculature-mediated IFESC regulations, which explain how the epidermis adjusts its size in orchestration with dermal constituents in dynamic skin.

Relationship between age and sex and the numbers of ingestions and swallows for foods of different textures among healthy adults

BACKGROUND

The number of swallows needed per single ingestion of food is an important index when assisting a patient with dysphagia in eating. While providing meal assistance, the caregiver may assume that one ingestion is completed with one swallow and then may administer the next ingestion even if the individual's mouth still has remaining food from the previous ingestions, increasing the risk for aspiration and choking.

OBJECTIVE

The objective of this pilot study was to clarify the differences in foods ingested and swallowed because of influencing factors such as age and gender among healthy adults.

METHODS

The study enrolled 110 healthy adults (47.4 ± 15.8 years; 57 males, 53 females). The numbers of ingestions and swallows were counted and evaluated by food type (pilaf, 100 g; yogurt 80 g; and sponge cake, 35 g) and participant age and sex and analyzed by least-squares multiple regression analysis.

RESULTS

The mean numbers of ingestion/swallows were pilaf, 12.5 ± 3.2/13.4 ± 4.2; yogurt, 8.8 ± 2.1/10.8 ± 2.1; and sponge cake, 5.8 ± 2.1/7.0 ± 2.1. The mean number of ingestions and swallows for all foods were higher for female participants compared with male participants. Statistical analysis identified sex as a significant influencing factor for the number of ingestion for all foods. For the number of swallows, the significant influencing factors were sex for sponge cake and age for pilaf and yogurt.

CONCLUSION

For the test foods of different textures, sex and age were significant influencing factors for the numbers of ingestions and swallows. Further research is needed to elucidate the problem areas in this pilot study.

Relationship between age and the impact of revascularization on mortality in patients with non-ST-elevation myocardial infarction

Background

It is known that the early coronary revascularization in patients with non-ST-elevation myocardial infarction (NSTEMI) was associated with favorable clinical outcomes. However, it is still unclear whether this efficacy is equivalent over all the ages of the patients.

Methods

Patients with NSTEMI were screened from the database of the Tokyo CCU network registry. Of those, the patients treated without revascularization (medical treatment) were matched with the patients receiving revascularization by propensity score matching. The probabilities of in-hospital death were calculated in the logistic regression model. In two subgroups stratified according to median of the age (elderly and non-elderly subgroups), the odds ratios of revascularization for in-hospital death were calculated.

Results

In the patients registered between 2013 and 2017, 4,851 patients with NSTEMI were identified. After the screening, 370 patients with medical treatment were matched with 370 patients treated with revascularization. The incidence of in-hospital death was significantly higher in the patients with medical treatment (20.3% vs 13.0%, P=0.01). The two probability curves of in-hospital death in patients with and without revascularization converged as age increased. In the elderly subgroup, the revascularization was not significantly associated with favorable outcome of mortality, whereas it had a significant impact on mortality in the non-elderly subgroup (odds ratio: 0.47 [95% CI 0.23–0.95]).

Conclusion

The impact of revascularization on short-term mortality in patients with NSTEMI tended to be reduced as age increased.

Funding Acknowledgement

Type of funding source: None

Predictors of in-hospital mortality in patients with acute myocardial infarction due to unprotected left main trunk lesion: insight from the Tokyo Cardiovascular Care Unit network multicenter registry

Background

Acute myocardial infarction (AMI) due to unprotected left main trunk (LMT) lesion remains a clinical challenge because it requires prompt and efficient revascularization in catastrophic clinical presentation. However, predictors of in-hospital prognosis in patients with LMT-AMI are still not fully understood.

Purpose

To examine the predictors of in-hospital mortality in patients with LMT-AMI.

Methods

From 20,257 AMI patients in the Tokyo Cardiovascular Care Unit network registry (comprising 72 hospitals) from 2013 to 2017, we identified 371 (1.8%) eligible LMT-AMI patients without a history of coronary artery bypass grafting (CABG) and divided them into two groups: 254 survivors and 117 non-survivors. Measured variables included patient demographics, vital signs, laboratory data on admission, and in-hospital treatment. The outcome was in-hospital mortality. We performed a multivariable logistic regression analysis for in-hospital mortality with adjustment for the following 9 potential confounders, based on previous studies: (1) age, (2) sex, (3) Killip class, (4) ST elevation, (5) wide QRS (>120 msec), (6) the Thrombolysis in Myocardial Infarction (TIMI) grade on initial coronary angiography, (7) number of vessels with significant stenosis other than LMT, (8) renal dysfunction on admission, and (9) plasma glucose on admission.

Results

Overall, mean age was 70.6±11.8 years and 81.9% were male. ST-elevation myocardial infarction accounted for 61.8%. Cardiac arrest was observed in 102 (33.6%) patients. Percutaneous coronary intervention and CABG were performed in 302 (81.8%) and 63 (17.0%) patients, respectively. Intra-aortic balloon pumping and veno-arterial extracorporeal membranous oxygenation were used in 288 (77.8%) and 81 (21.9%) patients, respectively. In-hospital mortality was 31.5%. Multivariable logistic regression analysis showed that higher in-hospital mortality was significantly associated with Killip class IV (adjusted odds ratio 3.41 [95% confidence interval 1.36–8.56]; reference: Killip I), TIMI grade 0 (3.51 [1.22–10.14]; reference: TIMI grade 3), renal dysfunction (estimated glomerular filtration <60 mL/min/1.73m2; 6.48 [2.53–16.57]), and high plasma glucose on admission (>150 mg/dl; 3.64 [1.33–9.97]). Age, sex, ST-elevation, wide QRS, and multi-vessel disease were not significantly associated with in-hospital mortality.

Conclusions

LMT-AMI remains life-threatening in the current era of widely available revascularization. Our results showed that haemodynamic compromise, no coronary flow, renal dysfunction, and high plasma glucose on admission were strong predictors of in-hospital mortality after LMT-AMI. Given the high cardiac arrest rate, more aggressive therapeutic measures including mechanical circulatory support may be required to improve the prognosis of LMT-AMI.

Funding Acknowledgement

Type of funding source: None

The impact of low diastolic blood pressure on 30-day mortality of patients with acute myocardial infarction

Background

It is known that low diastolic blood pressure (DBP) is associated with long-term cardiovascular events after acute myocardial infarction (AMI). However, the impact of low diastolic blood pressure on short-term outcome has not yet been well investigated.

Methods and results

We included 15,208 patients who were hospitalized for AMI and registered in the Tokyo CCU network registry between 2013 and 2016. Thirty-day in-hospital mortality rate was 4.8% (728/15,208). To assess the relationship between DBP at the time of admission and 30-day mortality non-linearly, spline regression model was applied with the stratification of the cohort according to tercile of systolic blood pressure (SBP, low:≤122 mmHg, intermediate:123–148 mmHg, high:≥149 mmHg) and J-curve phenomenon was observed in the low and high SBP groups. In multivariate logistic regression analysis, adjusted odds ratio of the lowest quintile of DBP (≤64 mmHg) was 1.65 (95% CI:1.02–2.66) in low SBP group and 4.55 (95% CI:1.72–12.00) in high SBP group.

Conclusion

Low DBP was associated with increased 30-day in-hospital mortality rate after AMI even in patients with high SBP.

Funding Acknowledgement

Type of funding source: None

Genome editing with the donor plasmid equipped with synthetic crRNA-target sequence

CRISPR/Cas-mediated genome editing is a powerful tool for generating genetically mutated cells and organisms. Linearisation of donor cassettes with this system has been shown to facilitate both transgene donor insertion and targeted knock-in. Here, we developed a donor plasmid that we name pCriMGET (plasmid of synthetic CRISPR coded RNA target sequence-equipped donor plasmid-mediated gene targeting), in which an off-target free synthetic CRISPR coded RNA-target sequence (syn-crRNA-TS) is incorporated with a multi-cloning site, where a donor cassette can be inserted. With co-expression of Cas9 and the syn-crRNA-TS guide RNA (gRNA), pCriMGET provides a linearised donor cassette in vivo, thereby promoting the transgene donor insertion and targeted knock-in. When co-injected with Cas9 protein and gRNA into murine zygotes, pCriMGET yielded around 20% transgene insertion in embryos. This method also achieved more than 25% in-frame knock-in at the mouse Tbx3 gene locus without predicted insertion-deletion mutations using a transgene donor with 400-bp homology arms. pCriMGET is therefore useful as a versatile CRISPR/Cas9-cleavable donor plasmid for efficient integration and targeted knock-in of exogenous DNA in mice.

H3K9 Demethylases JMJD1A and JMJD1B Control Prospermatogonia to Spermatogonia Transition in Mouse Germline

Histone H3 lysine 9 (H3K9) methylation is dynamically regulated by methyltransferases and demethylases. In spermatogenesis, prospermatogonia differentiate into differentiating or undifferentiated spermatogonia after birth. However, the epigenetic regulation of prospermatogonia to spermatogonia transition is largely unknown. We found that perinatal prospermatogonia have extremely low levels of di-methylated H3K9 (H3K9me2) and that H3K9 demethylases, JMJD1A and JMJD1B, catalyze H3K9me2 demethylation in perinatal prospermatogonia. Depletion of JMJD1A and JMJD1B in the embryonic germline resulted in complete loss of male germ cells after puberty, indicating that H3K9me2 demethylation is essential for male germline maintenance. JMJD1A/JMJD1B-depleted germ cells were unable to differentiate into functional spermatogonia. JMJD1 isozymes contributed to activation of several spermatogonial stem cell maintenance genes through H3K9 demethylation during the prospermatogonia to spermatogonia transition, which we propose is key for spermatogonia development. In summary, JMJD1A/JMJD1B-mediated H3K9me2 demethylation promotes prospermatogonia to differentiate into functional spermatogonia by establishing proper gene expression profiles.

Innate-like CD27+CD45RBhigh γδ T Cells Require TCR Signaling for Homeostasis in Peripheral Lymphoid Organs

TCR signaling is required for homeostasis of naive αβ T cells. However, whether such a signal is necessary for γδ T cell homeostasis in the periphery remains unknown. In this study, we present evidence that a portion of Vγ2⁺ γδ T cells, one of the major γδ T cell subsets in the secondary lymphoid organs, requires TCR signaling for homeostasis. To attenuate γδTCR signals, we generated mice lacking Eγ4 (Eγ4^-/-), an enhancer located at the 3'-most end of the TCRγ locus. Overall, we found that in thymus, Eγ4 loss altered V-J rearrangement, chromatin accessibility, and transcription of the TCRγ locus in a distance-dependent manner. Vγ2⁺ γδ T cells in Eγ4^-/- mice developed normally both fetal and adult mouse thymi but were relatively reduced in number in spleen and lymph nodes. Although Vγ2 TCR transcription decreased in all subpopulations of Eγ4^-/- mice, the number of Vγ2⁺ γδ T cells decreased and TCR signaling was attenuated only in the innate-like CD27⁺CD45RB^high subpopulation in peripheral lymphoid organs. Consistently, CD27⁺CD45RB^high Vγ2⁺ γδ T cells from Eγ4^-/- mice transferred into Rag2-deficient mice were not efficiently recovered, suggesting that continuous TCR signaling is required for their homeostasis. Finally, CD27⁺CD45RB^high Vγ2⁺ γδ T cells from Eγ4^-/- mice showed impaired TCR-induced activation and antitumor responses. These results suggest that normal homeostasis of innate-like CD27⁺CD45RB^high Vγ2⁺ γδ T cells in peripheral lymphoid organs requires TCR signaling.

Oscillatory expression of Hes1 regulates cell proliferation and neuronal differentiation in the embryonic brain

The expression of the transcriptional repressor Hes1 oscillates in many cell types, including neural progenitor cells (NPCs), but the significance of Hes1 oscillations in development is not fully understood. To examine the effect of altered oscillatory dynamics of Hes1, we generated two types of Hes1 knock-in mice, a shortened (type-1) and an elongated (type-2) Hes1 gene, and examined their phenotypes focusing on neural development. Although both mutations affected Hes1 oscillations, the type-1 mutation dampened Hes1 oscillations more severely, resulting in much lower amplitudes. The average levels of Hes1 expression in type-1 mutant NPCs were also lower than in wild-type NPCs but similar to or slightly higher than those in Hes1 heterozygous mutant mice, which exhibit no apparent defects. Whereas type-2 mutant mice were apparently normal, type-1 mutant mice displayed smaller brains than wild-type mice and upregulated proneural gene expression. Furthermore, proliferation of NPCs decreased and cell death increased in type-1 mutant embryos. When Hes3 and Hes5 were additionally deleted, neuronal differentiation was also accelerated, leading to microcephaly. Thus, robust Hes1 oscillations are required for maintenance and proliferation of NPCs and the normal timing of neurogenesis, thereby regulating brain morphogenesis.

Light-induced silencing of neural activity in Rosa26 knock-in and BAC transgenic mice conditionally expressing the microbial halorhodopsin eNpHR3

An engineered light-inducible chloride pump, Natronomonas pharaonis halorhodopsin 3 (eNpHR3) enables temporally and spatially precise inhibition of genetically defined cell populations in the intact nervous tissues. In this report, we show the generation of new mouse strains that express eNpHR3-EYFP fusion proteins after Cre- and/or Flp-mediated recombination to optically inhibit neuronal activity. In these mouse strains, Cre/Flp recombination induced high levels of opsin expression. We confirmed their light-induced activities by brain slice whole-cell patch clamp experiments. eNpHR3-expressing neurons were optically hyperpolarized and silenced from firing action potentials. In prolonged silencing of action potentials, eNpHR3 was superior to eNpHR2, a former version of the engineered pump. Thus, these eNpHR3 mouse strains offer reliable genetic tools for light-induced inhibiting of neuronal activity in defined sets of neurons.

IL-7R-Dependent Phosphatidylinositol 3-Kinase Competes with the STAT5 Signal to Modulate T Cell Development and Homeostasis

T cell development and homeostasis requires IL-7R α-chain (IL-7Rα) signaling. Tyrosine Y449 of the IL-7Rα is essential to activate STAT5 and PI3K, whereas PI3K recruitment requires IL-7Rα methionine M452. How IL-7Rα activates and regulates both signaling pathways differentially remains unclear. To characterize differential signaling, we established two lines of IL-7Rα mutant mice: IL-7R-Y449F mice and IL-7R-M452L mice. IL-7R-Y449F mice showed decreased PI3K and STAT5 signals, whereas IL-7R-M452L mice showed decreased PI3K but significantly increased STAT5 signaling, owing to a competition between PI3K and STAT5 signaling through Y449 of IL-7Rα. The number of T, B, and mature innate lymphoid cells were markedly reduced in IL-7R-Y449F mice, whereas IL-7R-M452L mice showed impaired early T cell development and memory precursor effector T cell maintenance with the downregulation of transcription factor T cell factor-1. Peripheral T cell numbers increased in IL-7R-M452L mice with enhanced survival and homeostatic proliferation. Furthermore, although wild type and IL-7R-Y449F mice showed comparable Th1/Th2 differentiation, IL-7R-M452L mice exhibited impaired Th17 differentiation. We conclude that PI3K competes with STAT5 under IL-7Rα and maintains an appropriate signal balance for modulating T cell development and homeostasis. To our knowledge, this study provides a new insight into complex regulation of IL-7Rα signaling, which supports immune development and responses.

Enhanced lysosomal degradation maintains the quiescent state of neural stem cells

Quiescence is important for sustaining neural stem cells (NSCs) in the adult brain over the lifespan. Lysosomes are digestive organelles that degrade membrane receptors after they undergo endolysosomal membrane trafficking. Enlarged lysosomes are present in quiescent NSCs (qNSCs) in the subventricular zone of the mouse brain, but it remains largely unknown how lysosomal function is involved in the quiescence. Here we show that qNSCs exhibit higher lysosomal activity and degrade activated EGF receptor by endolysosomal degradation more rapidly than proliferating NSCs. Chemical inhibition of lysosomal degradation in qNSCs prevents degradation of signaling receptors resulting in exit from quiescence. Furthermore, conditional knockout of TFEB, a lysosomal master regulator, delays NSCs quiescence in vitro and increases NSC proliferation in the dentate gyrus of mice. Taken together, our results demonstrate that enhanced lysosomal degradation is an important regulator of qNSC maintenance.

It remains unclear why quiescent neural stem cells (qNSCs) in the subventricular zone of the mouse brain have enlarged lysosomes. Here, authors demonstrate that qNSCs exhibit higher lysosomal activity and degrade activated EGF receptor by endolysosomal degradation more rapidly than proliferating NSCs, which prevents the NSC exit from quiescence.

P889Clinical significance of four-dimensional flow magnetic resonance imaging measurement of turbulent kinetic energy for hypertrophic obstructive cardiomyopathy

Purpose

The aims of this study were to investigate the relationship between TKE value and echocardiographic findings, clinical symptoms and evaluate the usefulness of 4D flow MRI to distinguish hypertrophic obstructive cardiomyopathy (HOCM) from non-obstructive HCM (HNCM).

Methods

From April 2018 to January 2019, 18 hypertrophic obstructive cardiomyopathy (HOCM) and 14 non-obstructive HCM (HNCM) patients underwent 4D flow MRI. We investigated TKE value calculated by 4D flow MRI, echocardiographic findings; left ventricular pressure gradient (LVPG), mitral regurgitation (MR) and clinical symptom.

Results

HOCM was defined by the 30 mmHg or greater of LVPG (HOCM: 87.7±47.3 mmHg, HNCM; 5.8±7.8 mmHg, p<0.001). TKE value in HOCM patients was significantly higher than HNCM (14.2±4.7 mJ vs. 9.0±4.6 mJ, p<0.001). There was a significant positive linear relationship between TKE value and LVPG (r=0.488, p=0.046). There was no significant relationship between NYHA functional class and TKE value (p=0.47) or LVPG (p=0.11). ROC curve analysis showed that optimal cut off point of TKE value between HOCM and HNCM (sensitivity=95%, specificity=62%, AUC=0.798) was 9.270 mJ. Multiple linear regression showed that there was significant association between severity of MR and combination of TKE (p=0.015) or LVPG (p–=0.012). A representative case demonstrated the significant reduction of TKE value 1 week and 3 months after alcohol septal reduction compared with that obtained before the procedure (Figure)

Conclusion

Our findings suggest that 4D Flow MRI can effectively evaluate the energy dissipation associated with LV outflow tract obstruction and TKE value is useful for identifying HOCM. TKE value also can be the novel parameter of the severity of HOCM.

Reconsideration of three screening tests for dysphagia in patients with cerebrovascular disease performed by non-expert examiners

Dysphagia prevalence has increased with increasing elderly population worldwide. Therefore, early detection of dysphagia has become increasingly important. Repetitive saliva swallowing test (RSST), modified water swallowing test (MWST), and cervical auscultation, which are convenient for non-experts to assess eating and swallowing and have been frequently used in Japan since 20 years. Using aspiration and pharyngeal residues, the objective of this study was to elucidate the efficacy of the three screening tests performed by non-experts in patients who had swallowing disorders. In total, 102 patients with cerebrovascular diseases who were suspected of having dysphagia were assessed. A swallowing team assessed their swallowing capabilities; videofluoroscopy and screening tests were performed. RSST, MWST, and cervical auscultation were performed by junior dentists who were non-experts in dysphagia. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio in each examination were evaluated using results of aspiration in videofluoroscopy and pharyngeal residues. For aspiration, the highest sensitivity with cervical auscultation (VES) was 93.7%. For pharyngeal residue, the highest sensitivity with cervical auscultation (VES) was 84.3%. For piriform sinus residue, the highest sensitivity with cervical auscultation (VES) was 86.4%. Despite being evaluated by a non-expert, the sensitivity of cervical auscultation (VES) and MWST was ≥ 80%, suggesting their effectiveness as prescreening tests, although the range of specificity was 25.5-68.4% in all examinations. These tests are easy to perform and useful to screen for aspiration or pharyngeal residues before precision tests.

TRPM7 channels mediate spontaneous Ca2+ fluctuations in growth plate chondrocytes that promote bone development

During endochondral ossification of long bones, the proliferation and differentiation of chondrocytes cause them to be arranged into layered structures constituting the epiphyseal growth plate, where they secrete the cartilage matrix that is subsequently converted into trabecular bone. Ca²⁺ signaling has been implicated in chondrogenesis in vitro. Through fluorometric imaging of bone slices from embryonic mice, we demonstrated that live growth plate chondrocytes generated small, cell-autonomous Ca²⁺ fluctuations that were associated with weak and intermittent Ca²⁺ influx. Several genes encoding Ca²⁺-permeable channels were expressed in growth plate chondrocytes, but only pharmacological inhibitors of transient receptor potential cation channel subfamily M member 7 (TRPM7) reduced the spontaneous Ca²⁺ fluctuations. The TRPM7-mediated Ca²⁺ influx was likely activated downstream of basal phospholipase C activity and was potentiated upon cell hyperpolarization induced by big-conductance Ca²⁺-dependent K⁺ channels. Bones from embryos in which Trpm7 was conditionally knocked out during ex vivo culture exhibited reduced outgrowth and displayed histological abnormalities accompanied by insufficient autophosphorylation of Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) in the growth plate. The link between TRPM7-mediated Ca²⁺ fluctuations and CaMKII-dependent chondrogenesis was further supported by experiments with chondrocyte-specific Trpm7 knockout mice. Thus, growth plate chondrocytes generate spontaneous, TRPM7-mediated Ca²⁺ fluctuations that promote self-maturation and bone development.

Dephosphorylation of protamine 2 at serine 56 is crucial for murine sperm maturation in vivo

The posttranslational modification of histones is crucial in spermatogenesis, as in other tissues; however, during spermiogenesis, histones are replaced with protamines, which are critical for the tight packaging of the DNA in sperm cells. Protamines are also posttranslationally modified by phosphorylation and dephosphorylation, which prompted our investigation of the underlying mechanisms and biological consequences of their regulation. On the basis of a screen that implicated the heat shock protein Hspa4l in spermatogenesis, we generated mice deficient in Hspa4l (Hspa4l-null mice), which showed male infertility and the malformation of sperm heads. These phenotypes are similar to those of Ppp1cc-deficient mice, and we found that the amount of a testis- and sperm-specific isoform of the Ppp1cc phosphatase (Ppp1cc2) in the chromatin-binding fraction was substantially less in Hspa4l-null spermatozoa than that in those of wild-type mice. We further showed that Ppp1cc2 was a substrate of the chaperones Hsc70 and Hsp70 and that Hspa4l enhanced the release of Ppp1cc2 from these complexes, enabling the freed Ppp1cc2 to localize to chromatin. Pull-down and in vitro phosphatase assays suggested the dephosphorylation of protamine 2 at serine 56 (Prm2 Ser⁵⁶) by Ppp1cc2. To confirm the biological importance of Prm2 Ser⁵⁶ dephosphorylation, we mutated Ser⁵⁶ to alanine in Prm2 (Prm2 S56A). Introduction of this mutation to Hspa4l-null mice (Hspa4l ^-/-; Prm2 ^S56A/S56A) restored the malformation of sperm heads and the infertility of Hspa4l ^-/- mice. The dephosphorylation signal to eliminate phosphate was crucial, and these results unveiled the mechanism and biological relevance of the dephosphorylation of Prm2 for sperm maturation in vivo.

A timer for analyzing temporally dynamic changes in transcription during differentiation in vivo

Bending et al. establish a new tool, Timer of cell kinetics and activity (Tocky), revealing the temporal dynamics of cellular activation and differentiation in vivo. The tool analyzes the temporal sequence of molecular processes during cellular differentiation and can classify cells based on the frequency they receive signaling events in vivo.

Understanding the mechanisms of cellular differentiation is challenging because differentiation is initiated by signaling pathways that drive temporally dynamic processes, which are difficult to analyze in vivo. We establish a new tool, Timer of cell kinetics and activity (Tocky; or toki [time in Japanese]). Tocky uses the fluorescent Timer protein, which spontaneously shifts its emission spectrum from blue to red, in combination with computer algorithms to reveal the dynamics of differentiation in vivo. Using a transcriptional target of T cell receptor (TCR) signaling, we establish Nr4a3-Tocky to follow downstream effects of TCR signaling. Nr4a3-Tocky reveals the temporal sequence of events during regulatory T cell (Treg) differentiation and shows that persistent TCR signals occur during Treg generation. Remarkably, antigen-specific T cells at the site of autoimmune inflammation also show persistent TCR signaling. In addition, by generating Foxp3-Tocky, we reveal the in vivo dynamics of demethylation of the Foxp3 gene. Thus, Tocky is a tool for cell biologists to address previously inaccessible questions by directly revealing dynamic processes in vivo.

Transgenic mice that accept Luciferase- or GFP-expressing syngeneic tumor cells at high efficiencies

Jellyfish green fluorescent protein (GFP) and firefly luciferase can serve as versatile tracking markers for identification and quantification of transplanted cancer cells in vivo. However, immune reactions against these markers can hamper the formation of syngraft tumors and metastasis that follows. Here, we report two transgenic (Tg) mouse lines that express nonfunctional mutant marker proteins, namely modified firefly luciferase (Luc2) or enhanced GFP (EGFP). These mice, named as Tg-mLuc2 and Tg-mEGFP, turned out to be immunologically tolerant to the respective tracking markers and thus efficiently accepted syngeneic cancer cells expressing the active forms of the markers. We then injected intrarectally the F₁ hybrid Tg mice (BALB/c × C57BL/6J) with Colon-26 (C26) colon cancer cells that originated from a BALB/c mouse. Even when C26 cells expressed active Luc2 or EGFP, they formed primary tumors in the Tg mice with only 10⁴ cells per mouse compared with more than 10⁶ cells required in the nontransgenic BALB/c hosts. Furthermore, we detected metastatic foci of C26 cells in the liver and lungs of the Tg mice by tracking the specific reporter activities. These results show the usefulness of the Tg mouse lines as recipients for transplantation experiments with the non-self tracking marker-expressing cells.

Combined Loss of JMJD1A and JMJD1B Reveals Critical Roles for H3K9 Demethylation in the Maintenance of Embryonic Stem Cells and Early Embryogenesis

Histone H3 lysine 9 (H3K9) methylation is unevenly distributed in mammalian chromosomes. However, the molecular mechanism controlling the uneven distribution and its biological significance remain to be elucidated. Here, we show that JMJD1A and JMJD1B preferentially target H3K9 demethylation of gene-dense regions of chromosomes, thereby establishing an H3K9 hypomethylation state in euchromatin. JMJD1A/JMJD1B-deficient embryos died soon after implantation accompanying epiblast cell death. Furthermore, combined loss of JMJD1A and JMJD1B caused perturbed expression of metabolic genes and rapid cell death in embryonic stem cells (ESCs). These results indicate that JMJD1A/JMJD1B-meditated H3K9 demethylation has critical roles for early embryogenesis and ESC maintenance. Finally, genetic rescue experiments clarified that H3K9 overmethylation by G9A was the cause of the cell death and perturbed gene expression of JMJD1A/JMJD1B-depleted ESCs. We summarized that JMJD1A and JMJD1B, in combination, ensure early embryogenesis and ESC viability by establishing the correct H3K9 methylated epigenome.

Identification of nuclear localization signals in the human homeoprotein MSX1

MSX1 is one of the homeoproteins with the homeodomain (HD) sequence, which regulates proliferation and differentiation of mesenchymal cells. In this study, we investigated the nuclear localization signal (NLS) in the MSX1 HD by deletion and amino acid substitution analyses. The web-based tool NLStradamus predicted 2 putative basic motifs in the N- and C-termini of the MSX1 HD. Green fluorescent protein (GFP) chimera studies revealed that NLS1 (₁₆₁RKHKTNRKPR₁₇₀) and NLS2 (₂₁₆NRRAKAKR₂₂₃) were independently insufficient for robust nuclear localization. However, they can work cooperatively to promote nuclear localization of MSX1, as was shown by the 2 tandem NLS motifs partially restoring functional NLS, leading to a significant nuclear accumulation of the GFP chimera. These results demonstrate a unique NLS motif in MSX1, which consists of an essential single core motif in helix-I, with weak potency, and an auxiliary subdomain in helix-III, which alone does not have nuclear localization potency. Additionally, other peptide sequences, other than predicted 2 motifs in the spacer, may be necessary for complete nuclear localization in MSX1 HD.

Rescuing the aberrant sex development of H3K9 demethylase Jmjd1a-deficient mice by modulating H3K9 methylation balance

Histone H3 lysine 9 (H3K9) methylation is a hallmark of heterochromatin. H3K9 demethylation is crucial in mouse sex determination; The H3K9 demethylase Jmjd1a deficiency leads to increased H3K9 methylation at the Sry locus in embryonic gonads, thereby compromising Sry expression and causing male-to-female sex reversal. We hypothesized that the H3K9 methylation level at the Sry locus is finely tuned by the balance in activities between the H3K9 demethylase Jmjd1a and an unidentified H3K9 methyltransferase to ensure correct Sry expression. Here we identified the GLP/G9a H3K9 methyltransferase complex as the enzyme catalyzing H3K9 methylation at the Sry locus. Based on this finding, we tried to rescue the sex-reversal phenotype of Jmjd1a-deficient mice by modulating GLP/G9a complex activity. A heterozygous GLP mutation rescued the sex-reversal phenotype of Jmjd1a-deficient mice by restoring Sry expression. The administration of a chemical inhibitor of GLP/G9a enzyme into Jmjd1a-deficient embryos also successfully rescued sex reversal. Our study not only reveals the molecular mechanism underlying the tuning of Sry expression but also provides proof on the principle of therapeutic strategies based on the pharmacological modulation of epigenetic balance.

In eukaryotes, DNA wraps an octamer of the core histones. Covalent modifications on the histones have diverse biological functions including transcriptional regulation. Histone H3 lysine 9 (H3K9) methylation is a hallmark of transcriptionally silenced chromatin. In mammals, the sex-determining gene Sry initiates testis differentiation in embryonic gonads. Sry expression in gonads is fine-tuned in both space and time. Here, we demonstrated that fine-tuning of Sry expression is achieved by the balance in activities between H3K9 demethylase and H3K9 methyltransferase. We found that the GLP/G9a complex is the enzyme catalyzing H3K9 methylation of Sry. Based on this finding, we tried to rescue the sex-reversal phenotype of the mutant mice by modulating the H3K9 methylation balance of Sry. We succeeded by modulating the H3K9 methylation balance not only with a genetic approach but also with a chemical approach using an inhibitor of GLP/G9a enzyme. Aberrant histone methylation levels are associated with diseases, including cancer, and intellectual disability. Our study provides proof for the principle of therapeutic strategies based on the pharmacological modulation of histone methylation balance.

Tbx3-dependent amplifying stem cell progeny drives interfollicular epidermal expansion during pregnancy and regeneration

The skin surface area varies flexibly in response to body shape changes. Skin homeostasis is maintained by stem cells residing in the basal layer of the interfollicular epidermis. However, how the interfollicular epidermal stem cells response to physiological body shape changes remains elusive. Here, we identify a highly proliferative interfollicular epidermal basal cell population in the rapidly expanding abdominal skin of pregnant mice. These cells express Tbx3 that is necessary for their propagation to drive skin expansion. The Tbx3+ basal cells are generated from Axin2+ interfollicular epidermal stem cells through planar-oriented asymmetric or symmetric cell divisions, and express transit-amplifying cell marker CD71. This biased division of Axin2+ interfollicular epidermal stem cells is induced by Sfrp1 and Igfbp2 proteins secreted from dermal cells. The Tbx3+ basal cells promote wound repair, which is enhanced by Sfrp1 and Igfbp2. This study elucidates the interfollicular epidermal stem cell/progeny organisation during pregnancy and suggests its application in regenerative medicine.The abdominal skin expands rapidly during pregnancy. Here the authors show that a population of highly proliferative stem cell progenies expressing the transcription factor Tbx3 is required for abdominal skin expansion in pregnant mice.

Three-dimensional finite element model to predict patterns of pterygomaxillary dysjunction during Le Fort I osteotomy

The aim of this study was to determine whether non-linear three-dimensional finite element analysis (3D-FEA) can be applied to simulate pterygomaxillary dysjunction during Le Fort I osteotomy (LFI) not involving a curved osteotome (LFI-non-COSep), and to predict potential changes in the fracture pattern associated with extending the cutting line. Computed tomography (CT) image data (100 snapshots) after LFI were converted to 3D-CT images. 3D-FEA models were built using preoperative CT matrix data and used to simulate pterygomaxillary dysjunction. The pterygomaxillary dysjunction patterns predicted by the 3D-FEA models of pterygomaxillary dysjunction were classified into three categories and compared to the pterygomaxillary dysjunction patterns observed in the postoperative 3D-CT images. Extension of the cutting line was also simulated using the 3D-FEA models to predict the risk and position of pterygoid process fracture. The rate of agreement between the predicted pterygomaxillary dysjunction patterns and those observed in the postoperative 3D-CT images was 87.0% (κ coefficient 0.79). The predicted incidence of pterygoid process fracture was higher for cutting lines that extended to the pterygomaxillary junction than for conventional cutting lines (odds ratio 4.75; P<0.0001). 3D-FEA can be used to predict pterygomaxillary dysjunction patterns during LFI-non-COSep and provides useful information for selecting safer procedures during LFI-non-COSep.

Knockout mouse production assisted by Blm knockdown

Production of knockout mice using targeted embryonic stem cells (ESCs) is a powerful approach for investigating the function of specific genes in vivo. Although the protocol for gene targeting via homologous recombination (HR) in ESCs is already well established, the targeting efficiency varies at different target loci and is sometimes too low. It is known that knockdown of the Bloom syndrome gene, BLM, enhances HR-mediated gene targeting efficiencies in various cell lines. However, it has not yet been investigated whether this approach in ESCs is applicable for successful knockout mouse production. Therefore, we attempted to answer this question. Consistent with previous reports, Blm knockdown enhanced gene targeting efficiencies for three gene loci that we examined by 2.3–4.1-fold. Furthermore, the targeted ESC clones generated good chimeras and were successful in germline transmission. These data suggest that Blm knockdown provides a general benefit for efficient ESC-based and HR-mediated knockout mouse production.

Ectopic Aire Expression in the Thymic Cortex Reveals Inherent Properties of Aire as a Tolerogenic Factor within the Medulla

Cortical thymic epithelial cells (cTECs) and medullary thymic epithelial cells (mTECs) play essential roles in the positive and negative selection of developing thymocytes, respectively. Aire in mTECs plays an essential role in the latter process through expression of broad arrays of tissue-restricted Ags. To determine whether the location of Aire within the medulla is absolutely essential or whether Aire could also function within the cortex for establishment of self-tolerance, we used bacterial artificial chromosome technology to establish a semiknockin strain of NOD-background (β5t/Aire-transgenic) mice expressing Aire under control of the promoter of β5t, a thymoproteasome expressed exclusively in the cortex. Although Aire was expressed in cTECs as typical nuclear dot protein in β5t/Aire-Tg mice, cTECs expressing Aire ectopically did not confer transcriptional expression of either Aire-dependent or Aire-independent tissue-restricted Ag genes. We then crossed β5t/Aire-Tg mice with Aire-deficient NOD mice, generating a strain in which Aire expression was confined to cTECs. Despite the presence of Aire(+) cTECs, these mice succumbed to autoimmunity, as did Aire-deficient NOD mice. The thymic microenvironment harboring Aire(+) cTECs, within which many Aire-activated genes were present, also showed no obvious alteration of positive selection, suggesting that Aire's unique property of generating a self-tolerant T cell repertoire is functional only in mTECs.