The applications of high-flow nasal cannulas in pediatric intensive care units in Taiwan.

BACKGROUND: /purpose: The use of high-flow nasal cannulas (HFNC) in patients admitted to the pediatric intensive care unit (PICU) has gradually increased worldwide; however, details on clinical efficacy remain limited in Taiwan. Therefore, we explored the clinical characteristics and outcomes of pediatric patients using HFNC in the PICU. METHODS: Medical records were retrospectively collected from pediatric patients (aged <18 years) who received HFNC support from December 2021 to January 2023 in the PICU of a medical center. Outcome parameters included treatment failure (defined as increased respiratory support to advanced non-invasive ventilators or intubations), duration of support from HFNC, and changes in clinical parameters after initiating HFNC. RESULTS: A total of 261 episodes of HFNC use were included, with a failure rate of 24.5% and a median support length of 4 days. Multivariable analysis showed that infant age (adjusted odds ratio [aOR]: 2.1, p = 0.02) and accompanying complex chronic disease (aOR: 4.4, p = 0.014) were risk factors for treatment failure and a diagnosis of asthma or bronchiolitis had a lower hazard of treatment failure (aOR: 0.29, p = 0.025) than other diagnoses did. Improvements in clinical parameters, including pulse rate, respiratory rate, SpO2, and CO2 levels, were observed 24 h after the initiation of HFNC. CONCLUSION: The application of HFNC in the PICU in Taiwan is effective but should be performed with care in infants with accompanying complex chronic diseases. In addition to low treatment failure, HFNC utilizations stabilized the clinical parameters of children with asthma/bronchiolitis within one day.

High incidence of cerebrovascular lesions on magnetic resonance imaging in pediatric COVID-19 during omicron outbreak - A retrospective case series.

BACKGROUND: The incidence of pediatric hospitalizations has significantly increased since the spread of the omicron variant of COVID-19. Changes of characteristics in respiratory and neurological symptoms have been reported. We performed a retrospective, cross-sectional study to characterize the MRI change in children with an emphasis on the change of cerebral vasculatures. METHODS: We retrospectively collected clinical and MRI data of 31 pediatric patients with neurological symptoms during the acute infection and abnormalities on MRI during the outbreak of omicron variant from April 2022 to June 2022 in Taiwan. The clinical manifestations and MRI abnormalities were collected and proportion of patients with vascular abnormalities was calculated. RESULTS: Among 31 pediatric patients with post-COVID-19 neurological symptoms, MRI abnormalities were observed in 15 (48.4%), predominantly encephalitis/encephalopathy (73.3%). Notable MRI findings included focal diffusion-weighted imaging (DWI) hyperintensity in cerebral cortex and thalamus, diffuse cortical T2/DWI hyperintensity, and lesions in the medulla, pons, cerebellum, and splenium of corpus callosum. Vascular abnormalities were seen in 12 (80%) patients with MRI abnormalities, mainly affecting the middle cerebral arteries. The spectrum of neurological manifestations ranged from seizures to Alice in Wonderland syndrome, underscoring the diverse impact of COVID-19 on pediatric patients. CONCLUSION: A high proportion of vascular abnormalities was observed in pediatric patients with neurological involvements, suggesting that vascular involvement is an important mechanism of neurological manifestations in omicron variant infection.

Application of nested multiplex polymerase chain reaction respiratory and pneumonia panels in children with severe community-acquired pneumonia.

Community-acquired pneumonia (CAP) is a serious clinical concern. A lack of accurate diagnosis could hinder pathogen-directed therapeutic strategies. To solve this problem, we evaluated clinical application of nested multiplex polymerase chain reaction (PCR) in children with severe CAP. We prospectively enrolled 60 children with severe CAP requiring intensive care between December 2019 and November 2021 at a tertiary medical center. Nested multiplex PCR respiratory panel (RP) and pneumonia panel (PP) were performed on upper and lower respiratory tract specimens. We integrated standard-of-care tests and quantitative PCR for validation. The combination of RP, PP, and standard-of-care tests could detect at least one pathogen in 98% of cases and the mixed viral-bacterial detection rate was 65%. The positive percent agreement (PPA), and negative percent agreement (NPA) for RP were 94% and 99%; the PPA and NPA for PP were 89% and 98%. The distribution of pathogens was similar in the upper and lower respiratory tracts, and the DNA or RNA copies of pathogens in the lower respiratory tract were equal to or higher than those in the upper respiratory tract. PP detected bacterial pathogens in 40 (67%) cases, and clinicians tended to increase bacterial diagnosis and escalate antimicrobial therapy for them. RP and PP had satisfactory performance to help pediatricians make pathogenic diagnoses and establish therapy earlier. The pathogens in the upper respiratory tract had predictive diagnostic values for lower respiratory tract infections in children with severe CAP.

The impacts of the scope of benefits expansion on hospice care among adult decedents: a nationwide longitudinal observational study.

OBJECTIVES: Compared to aggressive treatment for patients at the end stage of life, hospice care might be more likely to satisfy such patients' need and benefits and improve their dignity and quality of life. Whether the reimbursement policy expansion affect the use of hospice care among various demographics characteristics and health status was unknown. Therefore, the purpose of this study was to explore the impacts of reimbursement policy expansion on hospice care use, and to investigate the effects on people with various demographics characteristics and health status. METHODS: We used the 2001-2017 Taiwan NHI claims data, Death Registry, and Cancer Registry in this study, and we included people who died between 2002 and 2017. The study period was divided into 4 sub-periods. hospice care use and the initiation time of 1st hospice care use were used as dependent variables; demographic characteristics and health status were also collected. RESULTS: There were 2,445,781 people who died in Taiwan during the study period. The results show that the trend of hospice care use increased over time, going steeply upward after the scope of benefits expansion, but the initiation time of 1st hospice care use did not increase after the scope of benefits expansion. The results also show that the effects of expansion varied among patients by demographic characteristics. CONCLUSION: The scope of benefits expansion might induce people's needs in hospice care, but the effects varied by demographic characteristics. Understanding the reasons for the variations in all populations would be the next step for Taiwan's health authorities.

The impact of the coronavirus disease 2019 epidemic and national public restrictions on Pediatric Intensive Care Units in Taiwan.

BACKGROUND/PURPOSE: Coronavirus disease 2019 (COVID-19) pandemic challenges pediatric health globally by limited medical accessibility. In response to COVID-19 epidemic in Taiwan, public restrictions were applied and the Level 3 alert was announced from May to July in 2021 for local outbreak. This study aims to analyze patients' clinical features and outcomes in the pediatric intensive care unit (PICU) during the COVID-19 epidemic with the Level 3 alert in Taiwan. METHODS: Medical records were retrospectively collected in patients admitted to the PICU of National Taiwan University Children's Hospital from May to July 2021 (Level 3 alert) and May to July 2019 and 2020 (control periods). Clinical characteristics and outcomes were compared between patients in the period with the Level 3 alert and control periods. RESULTS: During the study period, PICU monthly admissions significantly decreased in the Level 3 alert period and were negatively correlated with monthly newly confirmed COVID-19 cases. Patients admitted during the Level 3 alert were older, had higher disease severity, lower proportion of cardiovascular disease, and higher proportion of hematology-oncology diseases than those in the control group. After adjusting for the above factors, admission during Level 3 alert was an independent factor for higher mortality rate and prolonged length of stay (>14 days) in the PICU. CONCLUSION: During the COVID-19 epidemic with strict public restrictions, critically ill patients admitted to the PICU decreased but had increased disease severity, prolonged length of stay in the PICU, and higher mortality, reflecting the impact of quarantine and limited medical access.

Abusive head trauma: current practice of investigation and management in Taiwan.

INTRODUCTION: Abusive head trauma (AHT) is a worldwide leading cause of fatal head injuries in children under 2 years. This study aims to present the development of child protection medical service in Taiwan in the past decade. MATERIALS AND METHODS: This study reviews the evolution of the pediatric protection network and the cross-system professional training in Taiwan from 2013 to 2022. The recommendations of Taiwan Pediatric Association on the prevention and management of AHT and the Medical Professionals Manual of Child Abuse and Neglect proposed by the Ministry of Health and Welfare were reviewed. RESULTS: Considering the impact of the high incidence of severe sequelae and the mortality caused by of AHT, 10 regional centers for child protection medical service were founded in Taiwan to identify, recognize, and properly manage cases of AHT, which is easily overlooked by the healthcare providers. The child protection network across the healthcare, social welfare administration, and judicial systems facilitate the early detection, management, and proper disposition of the children with AHT. CONCLUSION: An increasing of the incidence of AHT is expected after the setting up of the child protection network and the continuing cross-system professional trainings. There is more consensus of the diagnosis and management of AHT than before in Taiwan. However, there is no end to protecting children from AHT.

Epidemiology of Cardiomyopathy in Taiwanese Population Aged Younger Than 65 Years.

Background: Few studies have investigated the epidemiology of cardiomyopathy (CMP) in the general population in Taiwan. The aim of this study was to investigate this issue. Methods: We identified patients aged < 65 years and diagnosed with CMP between 2001 and 2014 from the National Health Insurance Database of Taiwan 2000-2014. Those with known or presumed causes of CMP were further identified. Results: We identified 38,868 CMP patients (male/female = 2.13). Half had known or presumed causes of CMP, including coronary artery disease (23.6%), congenital heart disease (1.6%), metabolic disease (8.4%), conduction disturbance/dyssynchrony (2.2%), myocarditis (0.5%), muscular dystrophy (1.42%), Kawasaki disease (0.2%), nutrition problems or alcoholism (2.9%), and unspecified causes (12.4%). The incidence rates of CMP without known causes were 1.13 and 8.70 per 100,000 person-years in pediatric (0-19 years) and adult (20-64 years) populations, respectively. After an initial peak during infancy (9.16 per 100,000 person-years), the incidence declined to a nadir in those aged from 5 to 14 years, and then steadily increased during adulthood (26.51 per 100,000 person-years in those aged 60-64 years). Although mortality was higher in the pediatric (11.4%) than in the adult (1.5%) patients, the proportion of sudden death to all deaths was similar in the pediatric (9.9%) and adult (10.5%) patients. Conclusions: This study provides an epidemiological continuum of CMP in a Taiwanese population aged < 65 years. The results revealed an initial peak during infancy, followed by a decline in adolescence and a subsequent steady rise. The prognosis was poorer in the pediatric patients, and poorest in the infants. However, the risk of sudden death was the same in the adult and pediatric patients.

End-of-Life Care in Taiwan: Single-Center Retrospective Study of Modes of Death.

OBJECTIVES: Medical advances and the National Health Insurance coverage in Taiwan mean that mortality in the PICU is low. This study describes change in modes of death and end-of-life care in a single center, 2011-2017. SETTING: Multidisciplinary PICU in a tertiary referral Children's Hospital in Taiwan. PATIENTS: There were 316 deaths in PICU patients. INTERVENTIONS: Palliative care consultation in the PICU service occurred after the 2013 "Hospice Palliative Care Act" revision. MEASUREMENTS AND MAIN RESULTS: In the whole cohort, 22 of 316 patients (7%) were determined as "death by neurologic criteria". There were 94 of 316 patients (30%) who had an event needing cardiopulmonary resuscitation within 24 hours of death: 17 of these patients (17/94; 18%) died after failed cardiopulmonary resuscitation without a do-not-resuscitate order, and the other 77 of 94 patients (82%) had a do-not-resuscitate order after cardiopulmonary resuscitation. Overall, there were 200 of 316 patients (63%) who had a do-not-resuscitate order and were entered into the palliative program: 169 of 200 (85%) died after life-sustaining treatment was limited, and the other 31 of 200 (15%) died after life-sustaining treatment was withdrawn. From 2011 to 2017, the time-trend in end-of-life care showed the following associations: 1) a decrease in PICU mortality utilization rate, from 22% to 7% (p < 0.001); 2) a decrease in use of catecholamine infusions after do-not-resuscitate consent, from 87% to 47% (p = 0.001), in patients having limitation in life-sustaining treatment; and 3) an increase in withdrawal of life-sustaining treatment, from 4% to 31% (p < 0.001). CONCLUSIONS: In our practice in a single PICU-center in Taiwan, we have seen that the integration of a palliative care consultation service, developed after the revision of a national "Palliative Care Act," was associated with increased willingness to accept withdrawal of life-sustaining treatment and a lowered PICU care intensity at the end-of-life.

Down-regulation of ATF1 leads to early neuroectoderm differentiation of human embryonic stem cells by increasing the expression level of SOX2.

We reveal by high-throughput screening that activating transcription factor 1 (ATF1) is a novel pluripotent regulator in human embryonic stem cells (hESCs). The knockdown of ATF1 expression significantly up-regulated neuroectoderm (NE) genes but not mesoderm, endoderm, and trophectoderm genes. Of note, down-regulation or knockout of ATF1 with short hairpin RNA (shRNA), small interfering RNA (siRNA), or clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) was sufficient to up-regulate sex-determining region Y-box (SOX)2 and paired box 6 (PAX6) expression under the undifferentiated or differentiated conditions, whereas overexpression of ATF1 suppressed NE differentiation. Endogenous ATF1 was spontaneously down-regulated after d 1-3 of neural induction. By double-knockdown experiments, up-regulation of SOX2 was critical for the increase of PAX6 and SOX1 expression in shRNA targeting Atf1 hESCs. Using the luciferase reporter assay, we identified ATF1 as a negative transcriptional regulator of Sox2 gene expression. A novel function of ATF1 was discovered, and these findings contribute to a broader understanding of the very first steps in regulating NE differentiation in hESCs.-Yang, S.-C., Liu, J.-J., Wang, C.-K., Lin, Y.-T., Tsai, S.-Y., Chen, W.-J., Huang, W.-K., Tu, P.-W. A., Lin, Y.-C., Chang, C.-F., Cheng, C.-L., Lin, H., Lai, C.-Y., Lin, C.-Y., Lee, Y.-H., Chiu, Y.-C., Hsu, C.-C., Hsu, S.-C., Hsiao, M., Schuyler, S. C., Lu, F. L., Lu, J. Down-regulation of ATF1 leads to early neuroectoderm differentiation of human embryonic stem cells by increasing the expression level of SOX2.

[The Development of Child Life Services and the Child Life Services Model in Taiwan].

Child life services is a professional service that supports children and adolescents seeking medical treatment. These services provide age-appropriate medical understandings and psychological preparation, coping skills, and psychosocial support for children with the goal of reducing fear, anxiety, and psychological trauma during healthcare provision. In addition to supporting young patients, child life services also support family members and caregivers, facilitating their effective response to related disease and medical situations. Child life specialists are experts in providing child life services. This article reviews the historical development of child life services, including its development and theory, related professional training and education, and the application and intervention goals of child life services in medical care. Finally, the establishment and developmental model of promoting child life services in Taiwan are reviewed with the goal of providing information for the promotion and utilization of child life services by healthcare professionals in practice settings.

Sonic hedgehog antagonists induce cell death in acute myeloid leukemia cells with the presence of lipopolysaccharides, tumor necrosis factor-α, or interferons.

Due to the development of drug resistance, the outcome for the majority of patients with acute myeloid leukemia (acute myelogenous leukemia; AML) remains poor. To prevent drug resistance and increase the therapeutic efficacy of treating AML, the development of new combinatory drug therapies is necessary. Sonic hedgehog (Shh) is expressed in AML biopsies and is essential for the drug resistance of cancer stem cells of AML. AML patients are frequently infected by bacteria and exposed to lipopolysaccharide (LPS). LPS itself, its derivatives, and its downstream effectors, such as tumor necrosis factor-α (TNF-α) and interferons (IFNs), have been shown to provoke anti-tumor effects. The application of a Shh inhibitor against AML cells in the presence of LPS/TNF-α/IFNs has not been investigated. We found that the Shh inhibitor cyclopamine in combination with LPS treatment synergistically induced massive cell apoptosis in THP-1 and U937 cells. The cytotoxic effects of this combined drug treatment were confirmed in 5 additional AML cell lines, in primary AML cells, and in an AML mouse model. Replacing cyclopamine with another Shh inhibitor, Sant-1, had the same effect. LPS could be substituted by TNF-α or IFNs to induce AML cell death in combination with cyclopamine. Our results suggest a potential strategy for the development of new therapies employing Shh antagonists in the presence of LPS/TNF-α/IFNs for the treatment of AML patients.

A shRNA functional screen reveals Nme6 and Nme7 are crucial for embryonic stem cell renewal.

In contrast to the somatic cells, embryonic stem cells (ESCs) are characterized by its immortalization ability, pluripotency, and oncogenicity. Revealing the underlying mechanism of ESC characteristics is important for the application of ESCs in clinical medicine. We performed systematic functional screen in mouse ESCs with 4,801 shRNAs that target 929 kinases and phosphatases. One hundred and thirty-two candidate genes that regulate both ESC expansion and stem cell marker expression were identified. Twenty-seven out of the 132 genes were regarded as most important since knockdown of each gene induces morphological changes from undifferentiated to differentiated state. Among the 27 genes, we chose nonmetastatic cell 6 (Nme6, also named as Nm23-H6) and nonmetastatic cell 7 (Nme7, also designated as Nm23-H7) to study first. Nme6 and Nme7 both belong to the members of nucleoside diphosphate kinase family. We demonstrate that Nme6 and Nme7 are important for the regulation of Oct4, Nanog, Klf4, c-Myc, telomerase, Dnmt3B, Sox2, and ERas expression. Either knockdown of Nme6 or Nme7 reduces the formation of embryoid body (EB) and teratoma. The overexpression of either Nme6 or Nme7 can rescue the stem cell marker expression and the EB formation in the absence of leukemia inhibiting factor. This implies the importance of Nme6 and Nme7 in ESC renewal. This finding not only pinpoints Nme6 or Nme7 can regulate several critical regulators in ESC renewal but also increases our understanding of the ESC renewal and oncogenesis.

Increasing Trend and Effects of Pediatric Palliative Care on Children With Noncancer Diagnoses.

OBJECTIVES: Pediatric palliative care (PPC), especially among noncancer pediatric patients, faces challenges including late referral, limited patient care, and insufficient data for Asian patients. METHODS: This retrospective cohort study used the integrative hospital medical database between 2014 and 2018 to analyze the clinical characteristics, diagnoses, and end-of-life care for patients aged less than 20 who had died in our children's hospital, a tertiary referral medical center implementing PPC shared-care. RESULTS: In our cohort of 323 children, 240 (74.3%) were noncancer patients who a younger median age at death (5 vs. 122 months, P < 0.001), lower rate of PPC involvement (16.7 vs. 66%, P < 0.001), and fewer survival days after PPC consult compared to cancer patients (3 vs. 11, P = 0.01). Patients not receiving PPC had more ventilator support (OR 9.9, P < 0.001), and less morphine use on their final day of life (OR 0.1, P < 0.001). Also, patients not receiving PPC had more cardiopulmonary resuscitation on the last day of life (OR 15.3, P < 0.001) and died in the ICU (OR 8.8, P < 0.001). There was an increasing trend of noncancer patients receiving PPC between 2014 and 2018 (P < 0.001). CONCLUSIONS: High disparities exist between children receiving PPC in cancer versus noncancer patients. The concept of PPC is gradually becoming accepted in noncancer children and is associated with more pain-relief medication and less suffering during end-of-life care.

The implications of airway anomalies on children with congenital heart disease and bronchiolitis.

BACKGROUND: Bronchiolitis is a common airway infection in young children. Hemodynamically significant congenital heart disease (CHD) predicts a more complicated course. However, the role of airway anomalies remains unknown. METHODS: We retrospectively reviewed the records of patients under 2 years old, diagnosed with CHD, and admitted between January 2011 and December 2013, before the palivizumab era. Records of bronchiolitis admissions were also extracted. Patients were grouped according to CHD condition and airway anomalies. RESULTS: A total of 230 patients with CHD were enrolled. A total of 180 (78%) and 71 (31%) patients had hemodynamically significant CHD and airway anomalies, respectively. A total of 52 (22.6%) patients were admitted for bronchiolitis 78 times. Among them, 33 (63.5%) had hemodynamically significant CHD, and 28 (53.8%) had airway anomalies. In patients with bronchiolitis admissions, the mean ventilator use, intensive care unit stay, and hospital stay were 1.08, 4.08, and 15.19 days, respectively. When compared, the mean hospital stay for bronchiolitis patients with airway anomalies was significantly longer than that of those without airway anomalies (19.8 vs. 9.9 days, p = 0.008). When further divided the patients by the presence hemodynamic significance, patients with hemodynamically significant CHD and airway anomaly had longer hospital stay than those who had neither. (21.7 vs. 8.3 days, p = 0.004) Airway anomaly was a significant risk factor for longer hospital stay in linear regression model (p = 0.007). CONCLUSIONS: Airway anomalies are common in children with CHD and are associated with longer hospital stays on bronchiolitis admission. An active survey for airway anomalies and adequate prophylaxis for bronchiolitis infection might be important in the care of children with CHD associated with airway anomalies.

Clinical characteristics and factors associated with severe COVID-19 in hospitalized children during the SARS-CoV-2 Omicron pandemic in Taiwan.

BACKGROUND: Since April 2022, a notable increase in COVID-19 cases with the rapid spread of the SARS-CoV-2 Omicron variant has been reported in Taiwan. In the epidemic, children were one of the most vulnerable groups, so we analyzed their clinical presentations and factors associated with severe complications of COVID-19 in children. METHODS: We included hospitalized patients under 18 years old with lab-confirmed SARS-CoV-2 infection from March 1, 2022, to July 31, 2022. We collected the demographic and clinical characteristics of the patients. Patients requiring intensive care were defined as severe cases. RESULTS: Among the 339 enrolled patients, the median age was 31 months (interquartile range (IQR), 8-79.0 months); and 96 patients (28.3%) had underlying diseases. Fever was noted in 319 patients (94.1%) with a median duration of two days (IQR 2-3 days). Twenty-two patients (6.5%) were severe cases, including 10 patients (2.9%) with encephalopathy with abnormal neuroimaging and ten patients (2.9%) with shock. Two patients (0.6%) died. Patients with congenital cardiovascular disease (aOR: 21.689), duration of fever up to four days or more (aOR: 6.466), desaturation (aOR: 16.081), seizure (aOR: 20.92), and procalcitonin >0.5 ng/mL (aOR: 7.886) had a higher risk of severe COVID-19. CONCLUSIONS: Vital signs need close monitoring, early management and/or intensive care may be applied in COVID-19 patients with congenital cardiovascular diseases, fever lasting ≥4 days, seizures, desaturation and/or elevated procalcition since they are at higher risks of severe diseases.

Body mass index may modify asthma prevalence among low-birth-weight children.

Childhood asthma, a growing health concern, has been associated with low birth weight and elevated body mass index. This study tested the hypothesis that overweight and obese adolescents with a history of low birth weight are at even greater risk of developing asthma. A cohort of 75,871 junior high school students was screened for asthma during 1995-1996 in Taiwan. Birth weight and estimated gestational age were obtained from the birth registry. Logistic regression and simple regression analyses were adjusted for confounding variables. Asthma was more prevalent in those with birth weights below 3,000 g and higher adolescent body mass indexes. Furthermore, those with both characteristics were consistently most likely to have asthma. Whether the asthma diagnosis among low-birth-weight subjects was assigned by physicians or medical questionnaire, the risks were elevated for both overweight (physician diagnosis: odds ratio = 1.41; medical questionnaire: odds ratio = 1.25) and obese (physician diagnosis: odds ratio = 1.38; medical questionnaire: odds ratio = 1.47) boys as well as overweight (physician diagnosis: odds ratio = 1.63; medical questionnaire: odds ratio = 1.30) and obese (physician diagnosis: odds ratio = 1.44; medical questionnaire: odds ratio = 1.32) girls (P < 0.05). Low birth weight predisposes one to develop asthma, and excess body mass amplifies the risk. A sex difference was observed. This study suggests that prenatal care and nutritional counseling could reduce asthma prevalence.

Podocalyxin-Like Protein 1 Regulates Pluripotency through the Cholesterol Biosynthesis Pathway.

Deciphering signaling mechanisms critical for the extended pluripotent stem cell (EPSC) state and primed pluripotency is necessary for understanding embryonic development. Here, a membrane protein, podocalyxin-like protein 1 (PODXL) as being essential for extended and primed pluripotency, is identified. Alteration of PODXL expression levels affects self-renewal, protein expression of c-MYC and telomerase, and induced pluripotent stem cell (iPSC) and EPSC colony formation. PODXL is the first membrane protein reported to regulate de novo cholesterol biosynthesis, and human pluripotent stem cells (hPSCs) are more sensitive to cholesterol depletion than fibroblasts. The addition of exogenous cholesterol fully restores PODXL knockdown-mediated loss of pluripotency. PODXL affects lipid raft dynamics via the regulation of cholesterol. PODXL recruits the RAC1/CDC42/actin network to regulate SREBP1 and SREBP2 maturation and lipid raft dynamics. Single-cell RNA sequencing reveals PODXL overexpression enhanced chimerism between human cells in mouse host embryos (hEPSCs 57%). Interestingly, in the human-mouse chimeras, laminin and collagen signaling-related pathways are dominant in PODXL overexpressing cells. It is concluded that cholesterol regulation via PODXL signaling is critical for ESC/EPSC.

Comparative Analyses of Single-Cell Transcriptomic Profiles between In Vitro Totipotent Blastomere-like Cells and In Vivo Early Mouse Embryonic Cells.

The developmental potential within pluripotent cells in the canonical model is restricted to embryonic tissues, whereas totipotent cells can differentiate into both embryonic and extraembryonic tissues. Currently, the ability to culture in vitro totipotent cells possessing molecular and functional features like those of an early embryo in vivo has been a challenge. Recently, it was reported that treatment with a single spliceosome inhibitor, pladienolide B (plaB), can successfully reprogram mouse pluripotent stem cells into totipotent blastomere-like cells (TBLCs) in vitro. The TBLCs exhibited totipotency transcriptionally and acquired expanded developmental potential with the ability to yield various embryonic and extraembryonic tissues that may be employed as novel mouse developmental cell models. However, it is disputed whether TBLCs are 'true' totipotent stem cells equivalent to in vivo two-cell stage embryos. To address this question, single-cell RNA sequencing was applied to TBLCs and cells from early mouse embryonic developmental stages and the data were integrated using canonical correlation analyses. Differential expression analyses were performed between TBLCs and multi-embryonic cell stages to identify differentially expressed genes. Remarkably, a subpopulation within the TBLCs population expressed a high level of the totipotent-related genes Zscan4s and displayed transcriptomic features similar to mouse two-cell stage embryonic cells. This study underscores the subtle differences between in vitro derived TBLCs and in vivo mouse early developmental cell stages at the single-cell transcriptomic level. Our study has identified a new experimental model for stem cell biology, namely 'cluster 3', as a subpopulation of TBLCs that can be molecularly defined as near totipotent cells.

CXCL14 Maintains hESC Self-Renewal through Binding to IGF-1R and Activation of the IGF-1R Pathway.

Human embryonic stem cells (hESCs) have important roles in regenerative medicine, but only a few studies have investigated the cytokines secreted by hESCs. We screened and identified chemokine (C-X-C motif) ligand 14 (CXCL14), which plays crucial roles in hESC renewal. CXCL14, a C-X-C motif chemokine, is also named as breast and kidney-expressed chemokine (BRAK), B cell and monocyte-activated chemokine (BMAC), and macrophage inflammatory protein-2γ (MIP-2γ). Knockdown of CXCL14 disrupted the hESC self-renewal, changed cell cycle distribution, and further increased the expression levels of mesoderm and endoderm differentiated markers. Interestingly, we demonstrated that CXCL14 is the ligand for the insulin-like growth factor 1 receptor (IGF-1R), and it can activate IGF-1R signal transduction to support hESC renewal. Currently published literature indicates that all receptors in the CXCL family are G protein-coupled receptors (GPCRs). This report is the first to demonstrate that a CXCL protein can bind to and activate a receptor tyrosine kinase (RTK), and also the first to show that IGF-1R has another ligand in addition to IGFs. These findings broaden our understanding of stem cell biology and signal transduction.

Fibroblast-enriched endoplasmic reticulum protein TXNDC5 promotes pulmonary fibrosis by augmenting TGFß signaling through TGFBR1 stabilization.

Pulmonary fibrosis (PF) is a major public health problem with limited therapeutic options. There is a clear need to identify novel mediators of PF to develop effective therapeutics. Here we show that an ER protein disulfide isomerase, thioredoxin domain containing 5 (TXNDC5), is highly upregulated in the lung tissues from both patients with idiopathic pulmonary fibrosis and a mouse model of bleomycin (BLM)-induced PF. Global deletion of Txndc5 markedly reduces the extent of PF and preserves lung function in mice following BLM treatment. Mechanistic investigations demonstrate that TXNDC5 promotes fibrogenesis by enhancing TGFß1 signaling through direct binding with and stabilization of TGFBR1 in lung fibroblasts. Moreover, TGFß1 stimulation is shown to upregulate TXNDC5 via ER stress/ATF6-dependent transcriptional control in lung fibroblasts. Inducing fibroblast-specific deletion of Txndc5 mitigates the progression of BLM-induced PF and lung function deterioration. Targeting TXNDC5, therefore, could be a novel therapeutic approach against PF.