Longitudinal associations of social jetlag with obesity indicators among adolescents - Shanghai adolescent cohort.

OBJECTIVE: To explore the longitudinal association between social-jetlag (SJL) and obesity development among adolescents, sex-difference and related modifying factors in the association. METHODS: Based on Shanghai-Adolescent-Cohort during 2017-2021, a total of 609 students were investigated. In grade 6, 7 and 9, the information on SJL was collected using questionnaires, and anthropometric measures were conducted. The fingernail cortisol and progesterone levels in grade 6 (using LC-MS/MS) and body composition in grade 9 (using Inbody-S10) were measured. By the latent-class-mixture-modeling, two trajectories for SJL (high-level vs. low-level) throughout 4 years were developed. The prospective associations of SJL trajectories and weight/fat gains were analyzed by sex and under different (high/moderate/low) cortisol/progesterone stratifications. RESULTS: In grades 6-9, 39.00%-44.50 % of adolescents experienced at least 1 h of SJL. Compared with the low-level SJL trajectory, the high-level SJL trajectory was associated with greater differences in body-mass-index Z-scores and waist-to-height ratios across 4 years, higher levels of body-fat-percentage and fat-mass-index in grade 9 (P-values<0.05), and such associations were stronger among girls and under moderate-to-high (vs. low) baseline cortisol and progesterone levels. However, no significant associations among boys were observed. CONCLUSIONS: High-level SJL in adolescents may be associated with the development of obesity, especially among adolescent girls and under relatively high baseline cortisol and progesterone levels.

Interaction of prenatal maternal selenium and manganese levels on child neurodevelopmental trajectories-the Shanghai birth cohort study.

OBJECTIVE: The fetal brain is particularly plastic, and may be concurrently affected by chemical exposure and malnutritional factors. Selenium is essential for the developing brain, and excess manganese exposure may exert neurotoxic effects. However, few epidemiological studies have evaluated the interaction of manganese and selenium assessed in different prenatal stages on postnatal neurodevelopmental trajectories. METHODS: This study contained 1024 mother-child pairs in the Shanghai-birth-cohort study from 2013 to 2016 recruited since early/before pregnancy with complete data on manganese and selenium levels in different prenatal stages and infant neurodevelopmental trajectories. Whole blood manganese and selenium in early pregnancy and around birth were measured by inductively-coupled-plasma-mass-spectrometry (ICP-MS), children's cognitive development was evaluated at 6, 12, and 24 months of age using Age & Stage-Questionnaire (ASQ)-3 and Bayley-III. Multiple linear regression was used to investigate the interaction of prenatal selenium and manganese on neurodevelopmental trajectories. RESULTS: The prenatal manganese and selenium levels were 1.82 ± 0.98 µg/dL and 13.53 ± 2.70 µg/dL for maternal blood in early pregnancy, and 5.06 ± 1.67 µg/dL and 11.81 ± 3.35 µg/dL for umbilical cord blood, respectively. Higher prenatal Se levels were associated with better neurocognitive performances or the consistently-high-level trajectory (P < 0.05), with more significant associations observed in early pregnancy than around birth. However, such positive relationships became non-significant or even adverse in high (vs. low) manganese status, and the effect differences between low and high manganese were more significant in early pregnancy. CONCLUSIONS: Prenatal Selenium was positively associated with child neurodevelopment, but prenatal high manganese may mitigate such favorable effects. The effects were mainly observed in earlier prenatal stage.

Rapid increases in BMI waist to height ratio during adolescence and subsequent neurobehavioral deficits.

OBJECTIVE: The aim of this study was to explore prospective relationships between changing patterns of BMI/waist to height ratio (WHtR) during adolescence and subsequent neurobehavioral development. METHODS: In this prospective cohort study, randomized stratified sampling was used to recruit six middle schools and 609 students in Shanghai, China. In Grades 6, 7, and 9, the Youth Self Report scale was used to assess student neurobehavioral status and anthropometric measurements were conducted to calculate BMI z scores and WHtRs. Longitudinal data were analyzed using latent class mixture modeling to delineate trajectories of BMI z scores ("stable," "decreasing," "rapidly increasing") and WHtRs ("stable," "rapidly increasing"), and their associations with neurobehavioral status in Grade 9 were assessed. RESULTS: In Grades 6 through 9 (ages 11-15 years), the prevalence of overall obesity and abdominal obesity ranged from 10.7% to 13.0% and 13.0% to 19.8%, respectively. Compared with the stable BMI z score trajectory, the rapidly increasing BMI z score trajectory was longitudinally associated with delinquent behavior, aggressive behavior, and externalizing problems (incidence rate ratio: 1.564-1.613, adjusted p < 0.05). Compared with the stable WHtR trajectory, the rapidly increasing WHtR trajectory significantly predicted increased risks of social problems and delinquent behavior (incidence rate ratios: 1.776-1.967, adjusted p < 0.05). Significant associations of the rapidly increasing BMI z score/WHtR trajectories with subsequent neurobehavioral deficits were observed among girls (adjusted p < 0.05) but not among boys (adjusted p > 0.05). CONCLUSIONS: Rapid increases in BMI or WHtR during adolescence could predict subsequent neurobehavioral deficits, especially for externalizing behaviors. Timely intervention for weight control may be considered to promote adolescent mental health.

Homework, sleep insufficiency and adolescent neurobehavioral problems: Shanghai Adolescent Cohort.

BACKGROUND: The prospective associations between homework burdens and adolescent neurobehavioral problems, and whether sleep-durations mediated and sex modified such associations remained unclear. METHODS: Using Shanghai-Adolescent-Cohort study, 609 middle-school students were recruited and investigations took place at Grade 6, 7 and 9. Information on homework burdens (defined by homework completion-time and self-perceived homework difficulty), bedtime/wake-up-time and neurobehavioral problems was collected. Two patterns of comprehensive homework burdens ('high' vs. 'low') were identified by latent-class-analysis and two distinct neurobehavioral trajectories ('increased-risk' vs. 'low-risk') were formed by latent-class-mixture-modeling. RESULTS: Among the 6th-9th graders, the prevalence-rates of sleep-insufficiency and late-bedtime ranged from 44.0 %-55.0 % and 40.3 %-91.6 %, respectively. High homework burdens were concurrently associated with increased-risks of neurobehavioral problems (IRRs: 1.345-1.688, P < 0.05) at each grade, and such associations were mediated by reduced sleep durations (IRRs for indirect-effects: 1.105-1.251, P < 0.05). High homework burden at the 6th-grade (ORs: 2.014-2.168, P < 0.05) or high long-term (grade 6-9) homework burden (ORs: 1.876-1.925, P < 0.05) significantly predicted increased-risk trajectories of anxiety/depression and total-problems, with stronger associations among girls than among boys. The longitudinal associations between long-term homework burdens and increased-risk trajectories of neurobehavioral problems were mediated by reduced sleep-durations (ORs for indirect-effects: 1.189-1.278, P < 0.05), with stronger mediation-effects among girls. LIMITATIONS: This study was restricted to Shanghai adolescents. CONCLUSIONS: High homework burden had both short-term and long-term associations with adolescent neurobehavioral problems, with stronger associations among girls, and sleep-insufficiency may mediate such associations in a sex-specific manner. Approaches targeting appropriate homework-load/difficulty and sleep restoration may help prevent adolescent neurobehavioral problems.

Impacts of vitamin A deficiency on biological rhythms: Insights from the literature.

Vitamin A is essential for brain function, in addition to its important roles in vision, immunity, and reproduction. Previous studies have shown that retinoic acid (RA), the bioactive form of vitamin A, is involved in the regulation of various intracellular responses related to biological rhythms. RA is reported to affect the circadian rhythm by binding to RA receptors, such as receptors in the circadian feedback loops in the mammalian suprachiasmatic nucleus. However, evidence of the impacts of vitamin A deficiency (VAD) on biological rhythms is limited, and most of the related studies were conducted on animals. In this review, we described the physiological functions of biological rhythms and physiological pathways/molecular mechanisms regulating the biological rhythms. We then discussed the current understanding of the associations of VAD with biological rhythm disorders/diseases (sleep disorders, impairments in learning/memory, emotional disorders, and other immune or metabolism diseases) and summarized the currently proposed mechanisms (mainly by retinoid nuclear receptors and related proteins) for the associations. This review may help recognize the role of VAD in biological rhythm disorders and stimulate clinical or epidemiological studies to confirm the findings of related animal studies.

Pygo1 Regulates the Behavior of Human Non-Small-Cell Lung Cancer via the Wnt/ß-Catenin Pathway.

Abnormal activation of the classical Wnt pathway has been reported in non-small-cell lung cancer (NSCLC) previously. Pygo family genes, the core regulators of Wnt/ß-catenin signaling, were also reported to be involved in tumorigenesis. However, the role of the homolog Pygo1 in human lung cancer remains unclear. In the current study, we demonstrated an association of increased Pygo1 expression with consistent high nuclear ß-catenin signals across pathological tissue samples of early-stage human NSCLC. Overexpression of Pygo1 in lung cancer cells resulted in enhanced G1/S cell phase transformation, reduced apoptosis, and increased cell proliferation. These changes were accompanied by the downregulation of cell cycle-related proteins, such as RB, p16, p53, and p27Kip1, and increased expression of CyclinE1. Migration, wound healing, and colony formation assays revealed that Pygo1 overexpression enhanced the invasion and migration of lung cancer cells, increased the formation of clones, and suppressed E-cadherin expression. In addition, overexpression of Pygo1 in lung cancer cells led to an increase of ß-catenin/TCF4 complex, as well as upregulated expression of target genes of ß-catenin. In vivo experiments also revealed that Pygo1 overexpression promoted the tumorigenicity of a xenograft tumor model, while Wnt inhibition partially blocked the effect of Pygo1 overexpression. In conclusion, Pygo1 affects human NSCLC via the canonical Wnt/ß-catenin pathway, which provides new clues for lung cancer pathology.

Effects of single and combined exposure to lead and stress during pregnancy on offspring neurodevelopment.

OBJECTIVE: To assess associations of single and combined exposures to lead and stress during different stages of pregnancy with offspring neurodevelopment. METHODS: We measured prenatal lead (maternal blood-lead in early-pregnancy and umbilical-cord-blood-lead) and maternal stress levels in Shanghai-Birth-Cohort from 2013 to 2016. Maternal stress was assessed using Center-for-Epidemiological-Studies-Depression-Scale and Self-Rating-Anxiety-Scale during mid-pregnancy. The Ages-Stages-Questionnaires-3 (at 6/12-months-of-age) and Bayley-III (at 24-months-of-age) were both used to assess neurodevelopment. RESULTS: A total of 2132 mother-child pairs with both prenatal lead and stress measurements were included. The geometric-means of blood-lead in early-pregnancy and cord-blood-lead were 1.46 µg/dL and 1.33 µg/dL, respectively. Among the study women, 1.89 % and 0.14 % were screened positive for depression and anxiety. Adjusting for related confounders, the combined exposures had stronger adverse associations with offspring social-emotional skills than single exposures; and the combined exposure in early-pregnancy was associated with greater neurodevelopmental differences than combined exposure around-birth, especially in social-emotion at 24 months-of-age [ß (95 %CI): - 10.48(-17.42, -3.54) vs. - 5.95(-11.53, -0.36)]. CONCLUSIONS: Both single and combined prenatal exposures to lead/stress impaired infant neuro-development, and the effects of combined exposure may be more profound than single exposures. Combined exposure in early-pregnancy may be associated with worse neurodevelopmental outcomes than combined exposure around-birth, especially in social-emotional development.

School educational models and child mental health among K-12 students: a scoping review.

BACKGROUND: The promotion of mental health among children and adolescents is a public health imperative worldwide, and schools have been proposed as the primary and targeted settings for mental health promotion for students in grades K-12. This review sought to provide a comprehensive understanding of key factors involved in models of school education contributing to student mental health development, interrelationships among these factors and the cross-cultural differences across nations and societies. METHODS: This scoping review followed the framework of Arksey and O'Malley and holistically reviewed the current evidence on the potential impacts of school-related factors or school-based interventions on student mental health in recent 5 years based on the PubMed, Web of Science, Embase and PsycExtra databases. RESULTS/FINDINGS: After screening 558 full-texts, this review contained a total of 197 original articles on school education and student mental health. Based on the five key factors (including curriculum, homework and tests, physical activities, interpersonal relationships and after-school activities) identified in student mental development according to thematic analyses, a multi-component school educational model integrating academic, social and physical factors was proposed so as to conceptualize the five school-based dimensions for K-12 students to promote student mental health development. CONCLUSIONS: The lessons learned from previous studies indicate that developing multi-component school strategies to promote student mental health remains a major challenge. This review may help establish appropriate school educational models and call for a greater emphasis on advancement of student mental health in the K-12 school context among different nations or societies.

The Association of Maternal Emotional Status With Child Over-Use of Electronic Devices During the COVID-19 Pandemic.

The quarantine during the COVID-19 pandemic may generate high levels of maternal depression/anxiety, and maternal emotional status may affect child behavioral development. Online education during the pandemic may induce child over-use of electronic-devices. However, child electronic-device over-use (especially among children under 12 who are immature in physical and mental development) during the pandemic has not attracted sufficient attention, and the association of child over-use with maternal emotional status remains unknown. Therefore, this study aims to assess the characteristics of child electronic-device over-use and the association between maternal emotional status and child over-use among 1,300 children from nurseries (<3 years), kindergartens (3-6 years), and primary schools (6-12 years) in Shanghai and Wuhan during COVID-19. Mothers completed an online questionnaire (including the Self-Rating-Depression/Anxiety-Scales and Family-Environment-Scale). The use of electronic devices (mobile-phones, iPads, computers, and televisions) and online courses taken by the children were investigated. Associations of maternal emotional status with electronic-device-use by child age were analyzed. The proportions of children in nurseries, kindergartens and primary schools were 8.5, 44.5, and 47.0%, their percentages following online-courses were 24.5, 48.4, and 99.0%, and their rates of electronic-device over-use were 34.2, 62.2, and 93.4%, respectively. Significant associations were observed between higher maternal anxiety/depression levels and higher risks of mobile-phone/iPad over-use among preschoolers and primary-school students. Lower family intimacy and higher conflict levels were associated with higher maternal depression/anxiety levels and higher risks of electronic-device over-use. Our findings suggested that over-use of electronic-devices among children under 12 was common during COVID-19, especially among children ≥6 years, and online-teaching may exacerbate over-use. Maternal anxiety/depression levels were associated with over-use of portable internet-devices (mobile-phone/iPad), especially among preschoolers and school-aged students, and family environment may mediate the association. These findings may contribute to a better understanding of factors leading to over-use of electronic-device and developing strategies to decrease over-use during COVID-19.

Associations of childhood unintentional injuries with maternal emotional status during COVID-19.

BACKGROUND: To explore the characteristics of unintentional childhood-injury during the COVID-19 pandemic and assess the association of unintentional-injury with maternal emotional status. METHODS: A cross-sectional survey was conducted with a convenience sample of 1300 children under 12-years-old from 21 schools (including nurseries/ kindergartens/ primary schools) in Wuhan and Shanghai during March to April 2020, and the mothers completed questionnaires online. Self-rating Depression/Anxiety Scales were used to evaluate maternal emotional status, questions on child unintentional-injury were based on the International-Statistical-Classification-of-Diseases-and-Related-Health-Problems-version-10 (ICD-10), and a total of 11 kinds of unintentional injuries were inquired. Information on socio-demographic and family-background factors was also collected. RESULTS: The children of 0-4, 5-9, and 10-12 years accounted for 29.2, 55.2 and 15.6%, respectively, the unintentional-injury rates were 10.29, 4.18 and 3.45%, respectively (P < 0.001), and boys had higher rates than girls. The three leading causes included "being struck by/against", falls and animal bites (traffic-injury accounted for a small proportion). Lower maternal educational, living in suburban/rural (vs. urban) areas, grandparents (vs. mothers) being main caregivers, more child exposure to secondhand smoke, close relatives being suspected/ confirmed COVID-19 cases were associated with a higher risk of child unintentional-injury. After adjusting for related confounders, higher maternal depression levels were associated with a higher risk of unintentional injury. CONCLUSIONS: The characteristics of unintentional childhood injury were different from those in non-pandemic periods. The main causes, risk factors and the association of unintentional injury with maternal depression deserve attention for development of effective measures for preventing children from unintentional injury during COVID-19 pandemic.

Prenatal Maternal Low Selenium, High Thyrotropin, and Low Birth Weights.

In consideration of the potential roles of selenoproteins in thyroid function, we aimed to evaluate the association of low selenium status with hypothyroidism during pregnancy and the association of maternal low thyroid function with infant birth size. We conducted a prospective birth cohort study in Shanghai in 2010 and investigated 1931 pregnant mothers of gestational weeks 28-36. Maternal serum selenium and thyrotropin (TSH) levels were determined and birth weights and lengths of newborns were measured. Other covariates were obtained through maternal interviews and medical records. A non-linear association was observed between maternal selenium and TSH levels. Two-piecewise multivariable linear regression models were therefore applied to assess the association of serum selenium with TSH levels, and multivariable linear regression models were applied to assess the association of TSH levels with birth weight/length. Adjusting for potential confounders, when maternal serum selenium levels < 103.7 µg/L (P25th), each unit increase in selenium levels (µg/L) was significantly associated with a decrease of 0.014 µIU/mL in TSH levels (ß = - 0.014, 95%CI - 0.025, - 0.002, P = 0.023). However, when selenium levels ≥ 103.7 µg/L, there were no significant relationships between selenium and TSH (ß = 0.000, 95%CI - 0.001, 0.002, P = 0.859). Maternal TSH levels were significantly inversely associated with infant birth weight (ß = - 0.060, 95%CI - 0.100, - 0.010, P = 0.010). We observed a non-linear association between maternal selenium status and TSH levels. Low selenium status during pregnancy may associate with low thyroid function that was related with low birth weights. Graphical abstract .

The Preventive Effect of Computed Tomography Image-Guided Electroacupuncture Combined with Continuous Femoral Nerve Block on Deep Vein Thrombosis After Total Knee Arthroplasty Based on an Adaptive Algorithm.

Based on an adaptive algorithm model, this study proposed 2 special model structures of randomized fusion and an optimized convolution kernel and use it for image recognition. The adaptive algorithm model combined image-guided electroacupuncture with a continuous femoral nerve block to prevent deep vein thrombosis after total knee arthroplasty. A total of 200 patients after total knee arthroplasty were randomly divided into 4 groups. We assessed the incidence of postoperative lower limb deep vein thrombosis and platelet count before and after surgery. Electroacupuncture combined with continuous femoral nerve block can reduce the incidence of deep vein thrombosis and has obvious advantages in multimode prevention. The effective analgesia provided by electroacupuncture combined with continuous femoral nerve block relieved postoperative pain. It also enabled patients to participate in joint movement and lower limb muscle strength training as soon as possible, which not only is conducive to postoperative functional recovery, but also reduces the body stress response triggered by pain and the hypercoagulable state. Moreover, electroacupuncture stimulation of electroacupuncture points can reduce the inflammatory edema associated with surgery, improve blood circulation at the surgical site, and activate the body's anticoagulation mechanism. This study provides new ideas and references for formulating multimode prevention and control strategies.

Integrin-mediated Signaling via Paxillin-GIT1-PIX Promotes Localized Rac Activation at the Leading Edge and Cell Migration.

Rac activation is precisely regulated temporally and spatially by intracellular signaling pathways in migrating cells to guarantee the formation of specific cell protrusions-lamellipodia at the leading edge. Integrins-mediated adhesions also control the signaling pathway for localized Rac activation in the cells, but very few studies have been addressed in this field. In the study, we aim to focus on how integrin-mediated signaling affects localized Rac activation by reducing the paxillin expression with shRNA targeting paxillin. The results revealed that reduction of the paxillin expression in the cells inhibited the formation of focal adhesions and Rac activation. By using Rac FRET biosensor, Rac activation was localized at the leading edge of the cell, within the lamellipodium. A ternary complex of paxillin-GIT1-PIX could establish the signaling pathway in front of the cells. Thus, we described a mechanism of integrin-mediated signaling for localized Rac activation that upon ligand binding, activated integrin via the signaling pathway paxillin-GIT1-PIX promotes localized Rac activation at the leading edge and cell migration.

Laser ablation tomography for visualization of root colonization by edaphic organisms.

Soil biota have important effects on crop productivity, but can be difficult to study in situ. Laser ablation tomography (LAT) is a novel method that allows for rapid, three-dimensional quantitative and qualitative analysis of root anatomy, providing new opportunities to investigate interactions between roots and edaphic organisms. LAT was used for analysis of maize roots colonized by arbuscular mycorrhizal fungi, maize roots herbivorized by western corn rootworm, barley roots parasitized by cereal cyst nematode, and common bean roots damaged by Fusarium. UV excitation of root tissues affected by edaphic organisms resulted in differential autofluorescence emission, facilitating the classification of tissues and anatomical features. Samples were spatially resolved in three dimensions, enabling quantification of the volume and distribution of fungal colonization, western corn rootworm damage, nematode feeding sites, tissue compromised by Fusarium, and as well as root anatomical phenotypes. Owing to its capability for high-throughput sample imaging, LAT serves as an excellent tool to conduct large, quantitative screens to characterize genetic control of root anatomy and interactions with edaphic organisms. Additionally, this technology improves interpretation of root-organism interactions in relatively large, opaque root segments, providing opportunities for novel research investigating the effects of root anatomical phenes on associations with edaphic organisms.

High Stoichiometry Phosphorylation of Talin at T144/T150 or S446 Produces Contrasting Effects on Calpain-mediated Talin Cleavage and Cell Migration.

Focal adhesions are large multi-protein complexes that serve as the linkage between extracellular matrix (ECM) and actin cytoskeleton and control the network of signaling cascades underlying cell migration. Talin plays a key role in focal adhesion turnover, and calpain-mediated proteolysis of talin is central to focal adhesion disassembly, but its regulation is not well elucidated. Here we demonstrate that talin phosphorylation at three high stoichiometry sites on its head domain, T144 and T150, or S446, have contrasting effects on calpain-mediated cleavage of talin and cell migration by using site-directed mutagenesis to inhibit phosphorylation. Expression of talinT144A+T150A stimulated calpain-mediated cleavage of talin and accelerated focal adhesion disassembly, whereas expression of talinS446A fully inhibited talin cleavage by calpain, preventing focal adhesion disassembly. A large decrease in phospho-threonine or phospho-serine levels was seen with talinT144A+T150A or talinS446A respectively, while more active ERK was present in talinT144A+T150A than in talinS446A. Cell adhesion and transwell assays using uniformly expressing cells showed that expression of talinT144A+T150A or talinS446A have opposing effects on cell adhesion and migration. These findings define and highlight the integral role of site-specific high stoichiometry phosphorylation of talin in regulating calpain-mediated cleavage of talin and focal adhesion disassembly, thus controlling adhesion stability, cell adhesion and ultimately, cell migration.

Isolation and antitumor efficacy evaluation of a polysaccharide from Nostoc commune Vauch.

Nostoc commune Vauch. has been traditionally used as a healthy food and medicine for centuries especially in China. It has been demonstrated that the polysaccharides isolated from Nostoc commune Vauch. exhibit strong antimicrobial and antioxidant activities. However, little is known about their anticancer activities and the underlying mechanisms of action. Herein, we report the isolation of a polysaccharide from Nostoc commune Vauch. (NVPS), and its physicochemical properties were analyzed. In an attempt to demonstrate the potential application of NVPS in tumor chemotherapy, the in vitro antitumor activity was determined. NVPS significantly suppressed the growth and proliferation of MCF-7 and DLD1 cells. The molecular mechanism underlying this in vitro antitumor efficacy was elucidated, and the results indicated that NVPS simultaneously triggered intrinsic, extrinsic and endoplasmic reticulum stress (ERS)-mediated apoptotic signaling pathways. Collectively, these findings demonstrate that NVPS could be used as a novel promising source of natural antitumor agents.

iPS cell modeling of Best disease: insights into the pathophysiology of an inherited macular degeneration.

Best disease (BD) is an inherited degenerative disease of the human macula that results in progressive and irreversible central vision loss. It is caused by mutations in the retinal pigment epithelium (RPE) gene BESTROPHIN1 (BEST1), which, through mechanism(s) that remain unclear, lead to the accumulation of subretinal fluid and autofluorescent waste products from shed photoreceptor outer segments (POSs). We employed human iPS cell (hiPSC) technology to generate RPE from BD patients and unaffected siblings in order to examine the cellular and molecular processes underlying this disease. Consistent with the clinical phenotype of BD, RPE from mutant hiPSCs displayed disrupted fluid flux and increased accrual of autofluorescent material after long-term POS feeding when compared with hiPSC-RPE from unaffected siblings. On a molecular level, RHODOPSIN degradation after POS feeding was delayed in BD hiPSC-RPE relative to unaffected sibling hiPSC-RPE, directly implicating impaired POS handling in the pathophysiology of the disease. In addition, stimulated calcium responses differed between BD and normal sibling hiPSC-RPE, as did oxidative stress levels after chronic POS feeding. Subcellular localization, fractionation and co-immunoprecipitation experiments in hiPSC-RPE and human prenatal RPE further linked BEST1 to the regulation and release of endoplasmic reticulum calcium stores. Since calcium signaling and oxidative stress are critical regulators of fluid flow and protein degradation, these findings likely contribute to the clinical picture of BD. In a larger context, this report demonstrates the potential to use patient-specific hiPSCs to model and study maculopathies, an important class of blinding disorders in humans.

Five new amicoumacins isolated from a marine-derived bacterium Bacillus subtilis.

Four novel amicoumacins, namely lipoamicoumacins A-D (1-4), and one new bacilosarcin analog (5) were isolated from culture broth of a marine-derived bacterium Bacillus subtilis, together with six known amicoumacins. Their structures were elucidated on the basis of extensive spectroscopic (2D NNR, IR, CD and MS) analysis and in comparison with data in literature.

Biosensors of DsRed as FRET partner with CFP or GFP for quantitatively imaging induced activation of Rac, Cdc42 in living cells.

PURPOSE: The suboptimal features of the spectral properties of the leading fluorescence resonance energy transfer (FRET) pair, cyan fluorescent protein (CFP)/yellow fluorescent protein (YFP), limit the full promise of FRET imaging. To overcome the drawbacks, we developed FRET-based, intra-molecular biosensors consisting of CFP/discomona sp red fluorescent protein (DsRed) or green fluorescent protein (GFP)/DsRed as donor/acceptor fluorophores. PROCEDURES: The biosensors were expressed in NIH3T3 cells. In vitro fluorescence spectroscopy and Rho GTPase activation assays were used to confirm that Rac1 or Cdc42 was activated in serum-starved cells following stimulation with insulin or bradykinin. The transient changes of the amount, location, and translocation of activated Rac1 or Cdc42 in living cells were tracked with confocal imaging. RESULTS: The increase of FRET efficiency was achieved in the cells expressing the biosensors and was proportional to the levels of activated Rac1 or Cdc42. The localized, transitional, and transient FRET signals were directly and quantitatively imaged with high spatial and temporal resolution. The biosensors were used to analyze and judge the GEF or GAP activities of putative regulatory proteins for Rac1 or Cdc42. CONCLUSION: DsRed is a more suitable acceptor in FRET pair with CFP than with GFP in terms of the spectral overlap between the donor and acceptor. The approach can also be applied to many other types of protein behavior in living cells.

Expression, purification, and characterization of hepatitis B virus surface antigens (HBsAg) in yeast Pichia Pastoris.

Prevention of the prevalence of HB depends upon the development of efficient diagnostic reagent and preventive vaccine. Pichia pastoris offers many advantages over the other expression systems in the production of recombinant HBsAg. In this study, we reported that the recombinant P. pastoris strains were cultured in shake flasks and then scaled up in a 5.0-l bioreactor: approximately 27 mg/l of the protein and the maximal cell OD at 600 nm of 310 were achieved in the bioreactor. The recombinant HBsAg was purified by three steps of purification procedures. SDS-PAGE showed that the purified recombinant HBsAg constituted only one homogeneous band of approximately 24 kDa. CsCl density gradient ultracentrifugation assay indicated that the density of the HBsAg was 1.2 mg/ml, which was in agreement with the natural HBsAg, the HBsAg expressed in Saccharomyces cerevisiae and in mammalian cells. Electron microscope observation revealed that the purified recombinant HBsAg was homogeneous 22-nm particles, suggesting the HBsAg expressed in P. pastoris was self-assembled to virus-like structures. Competitive ELISA indicated that P. pastoris-derived HBsAg possessed the excellent immunoreaction with anti-HBsAg. Animal immunization showed that the immunogenicity of P. pastoris-derived HBsAg was superior to that of S. cerevisiae-derived HBsAg. Together, our results demonstrated that the recombinant HBsAg expressed in P. pastoris could provide promising, inexpensive, and large-scale materials for the diagnostic reagent and vaccine to prevent HBV infection.