Young osteocyte-derived extracellular vesicles facilitate osteogenesis by transferring tropomyosin-1.

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) can undergo inadequate osteogenesis or excessive adipogenesis as they age due to changes in the bone microenvironment, ultimately resulting in decreased bone density and elevated risk of fractures in senile osteoporosis. This study aims to investigate the effects of osteocyte senescence on the bone microenvironment and its influence on BMSCs during aging. RESULTS: Primary osteocytes were isolated from 2-month-old and 16-month-old mice to obtain young osteocyte-derived extracellular vesicles (YO-EVs) and senescent osteocyte-derived EVs (SO-EVs), respectively. YO-EVs were found to significantly increase alkaline phosphatase activity, mineralization deposition, and the expression of osteogenesis-related genes in BMSCs, while SO-EVs promoted BMSC adipogenesis. Neither YO-EVs nor SO-EVs exerted an effect on the osteoclastogenesis of primary macrophages/monocytes. Our constructed transgenic mice, designed to trace osteocyte-derived EV distribution, revealed abundant osteocyte-derived EVs embedded in the bone matrix. Moreover, mature osteoclasts were found to release osteocyte-derived EVs from bone slices, playing a pivotal role in regulating the functions of the surrounding culture medium. Following intravenous injection into young and elderly mouse models, YO-EVs demonstrated a significant enhancement of bone mass and biomechanical strength compared to SO-EVs. Immunostaining of bone sections revealed that YO-EV treatment augmented the number of osteoblasts on the bone surface, while SO-EV treatment promoted adipocyte formation in the bone marrow. Proteomics analysis of YO-EVs and SO-EVs showed that tropomyosin-1 (TPM1) was enriched in YO-EVs, which increased the matrix stiffness of BMSCs, consequently promoting osteogenesis. Specifically, the siRNA-mediated depletion of Tpm1 eliminated pro-osteogenic activity of YO-EVs both in vitro and in vivo. CONCLUSIONS: Our findings suggested that YO-EVs played a crucial role in maintaining the balance between bone resorption and formation, and their pro-osteogenic activity declining with aging. Therefore, YO-EVs and the delivered TPM1 hold potential as therapeutic targets for senile osteoporosis.

Ångstrom-scale silver particles ameliorate collagen-induced and K/BxN-transfer arthritis in mice via the suppression of inflammation and osteoclastogenesis.

OBJECTIVE: Nanoparticles (NPs) hold a great promise in combating rheumatoid arthritis, but are often compromised by their toxicities because the currently used NPs are usually synthesized by chemical methods. Our group has previously fabricated Ångstrom-scale silver particles (AgÅPs) and demonstrated the anti-tumor and anti-sepsis efficacy of fructose-coated AgÅPs (F-AgÅPs). This study aimed to uncover the efficacy and mechanisms of F-AgÅPs for arthritis therapy. METHODS: We evaluated the efficacy of F-AgÅPs in collagen-induced arthritis (CIA) mice. We also compared the capacities of F-AgÅPs, the commercial AgNPs, and the clinical drug methotrexate (MTX) in protecting against K/BxN serum-transfer arthritis (STA) mice. Moreover, we evaluated the effects of F-AgÅPs and AgNPs on inflammation, osteoclast formation, synoviocytes migration, and matrix metalloproteinases (MMPs) production in vitro and in vivo. Meanwhile, the toxicities of F-AgÅPs and AgNPs in vitro and in vivo were also tested. RESULTS: F-AgÅPs significantly prevented bone erosion, synovitis, and cartilage damage, attenuated rheumatic pain, and improved the impaired motor function in mouse models of CIA or STA, the anti-rheumatic effects of which were comparable or stronger than AgNPs and MTX. Further studies revealed that F-AgÅPs exhibited similar or greater inhibitory abilities than AgNPs to suppress inflammation, osteoclast formation, synoviocytes migration, and MMPs production. No obvious toxicities were observed in vitro and in vivo after F-AgÅPs treatment. CONCLUSIONS: F-AgÅPs can effectively alleviate arthritis without notable toxicities and their anti-arthritic effects are associated with the inhibition of inflammation, osteoclastogenesis, synoviocytes migration, and MMPs production. Our study suggests the prospect of F-AgÅPs as an efficient and low-toxicity agent for arthritis therapy.

[Effect of procalcitonin on lipopolysaccharide-induced expression of nucleotide-binding oligomerization domain-like receptor protein 3 and caspase-1 in human umbilical vein endothelial cells]. / é™é’™ç´ åŽŸå¯¹è„‚å¤šç³–è¯±å¯¼çš„äººè„é™è„‰å† çš®ç»†èƒžNLRP3和caspase-1表达的影响.

OBJECTIVES: To study the effect of procalcitonin (PCT) on lipopolysaccharide (LPS)-induced expression of the pyroptosis-related proteins nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and caspase-1 in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were induced by LPS to establish a model of sepsis-induced inflammatory endothelial cell injury. The experiment was divided into two parts. In the first part, HUVECs were randomly divided into four groups: normal control, LPS (1 µg/mL), PCT (10 ng/mL), and LPS+PCT (n=3 each). In the second part, HUVECs were randomly grouped: normal control, LPS, and LPS+PCT of different concentrations (0.1, 1, 10, and 100 ng/mL) (n=3 each). Quantitative real-time PCR and Western blot were used to measure the mRNA and protein expression levels of NLRP3 and caspase-1 in each group. RESULTS: In the first experiment: compared with the normal control group, the PCT, LPS, and LPS+PCT groups had significantly upregulated mRNA and protein expression levels of NLRP3 and caspase-1 (P<0.05); compared with the LPS group, the LPS+PCT group had significantly downregulated mRNA and protein expression levels of NLRP3 and caspase-1 (P<0.05). In the second experiment: compared with those in the LPS group, the mRNA and protein expression levels of NLRP3 and caspase-1 in the LPS+PCT of different concentrations groups were significantly downregulated in a concentration-dependent manner (P<0.05). CONCLUSIONS: LPS can promote the expression of the pyroptosis-related proteins NLRP3 and caspase-1 in HUVECs, while PCT can inhibit the LPS-induced expression of the pyroptosis-related proteins NLRP3 and caspase-1 in HUVECs in a concentration-dependent manner.

Predicting Sepsis Mortality in a Population-Based National Database: Machine Learning Approach.

BACKGROUND: Although machine learning (ML) algorithms have been applied to point-of-care sepsis prognostication, ML has not been used to predict sepsis mortality in an administrative database. Therefore, we examined the performance of common ML algorithms in predicting sepsis mortality in adult patients with sepsis and compared it with that of the conventional context knowledge-based logistic regression approach. OBJECTIVE: The aim of this study is to examine the performance of common ML algorithms in predicting sepsis mortality in adult patients with sepsis and compare it with that of the conventional context knowledge-based logistic regression approach. METHODS: We examined inpatient admissions for sepsis in the US National Inpatient Sample using hospitalizations in 2010-2013 as the training data set. We developed four ML models to predict in-hospital mortality: logistic regression with least absolute shrinkage and selection operator regularization, random forest, gradient-boosted decision tree, and deep neural network. To estimate their performance, we compared our models with the Super Learner model. Using hospitalizations in 2014 as the testing data set, we examined the models' area under the receiver operating characteristic curve (AUC), confusion matrix results, and net reclassification improvement. RESULTS: Hospitalizations of 923,759 adults were included in the analysis. Compared with the reference logistic regression (AUC: 0.786, 95% CI 0.783-0.788), all ML models showed superior discriminative ability (P<.001), including logistic regression with least absolute shrinkage and selection operator regularization (AUC: 0.878, 95% CI 0.876-0.879), random forest (AUC: 0.878, 95% CI 0.877-0.880), xgboost (AUC: 0.888, 95% CI 0.886-0.889), and neural network (AUC: 0.893, 95% CI 0.891-0.895). All 4 ML models showed higher sensitivity, specificity, positive predictive value, and negative predictive value compared with the reference logistic regression model (P<.001). We obtained similar results from the Super Learner model (AUC: 0.883, 95% CI 0.881-0.885). CONCLUSIONS: ML approaches can improve sensitivity, specificity, positive predictive value, negative predictive value, discrimination, and calibration in predicting in-hospital mortality in patients hospitalized with sepsis in the United States. These models need further validation and could be applied to develop more accurate models to compare risk-standardized mortality rates across hospitals and geographic regions, paving the way for research and policy initiatives studying disparities in sepsis care.

Harmine targets inhibitor of DNA binding-2 and activator protein-1 to promote preosteoclast PDGF-BB production.

Osteoporosis is one of the most common metabolic bone diseases affecting millions of people. We previously found that harmine prevents bone loss in ovariectomized mice via increasing preosteoclast platelet-derived growth factor-BB (PDGF-BB) production and type H vessel formation. However, the molecular mechanisms by which harmine promotes preosteoclast PDGF-BB generation are still unclear. In this study, we revealed that inhibitor of DNA binding-2 (Id2) and activator protein-1 (AP-1) were important factors implicated in harmine-enhanced preosteoclast PDGF-BB production. Exposure of RANKL-induced Primary bone marrow macrophages (BMMs), isolated from tibiae and femora of mice, to harmine increased the protein levels of Id2 and AP-1. Knockdown of Id2 by Id2-siRNA reduced the number of preosteoclasts as well as secretion of PDGF-BB in RANKL-stimulated BMMs administrated with harmine. Inhibition of c-Fos or c-Jun (components of AP-1) both reversed the stimulatory effect of harmine on preosteoclast PDGF-BB production. Dual-luciferase reporter assay analyses determined that PDGF-BB was the direct target of AP-1 which was up-regulated by harmine treatment. In conclusion, our data demonstrated a novel mechanism involving in the production of PDGF-BB increased by harmine, which may provide potential therapeutic targets for bone loss diseases.

Transforming growth factor-ß1 decreases erythropoietin production through repressing hypoxia-inducible factor 2α in erythropoietin-producing cells.

BACKGROUND: Renal erythropoietin (EPO)-producing (REP) cells produce EPO through hypoxia-inducible factor (HIF) 2α-activated gene transcription. Insufficient EPO production leads to anemia in patients with chronic kidney disease. Although recombinant EPO is effective to improve anemia, no reliable REP cell lines limit further progress of research and development of novel treatment. METHODS: We screened Epo mRNA expression in mouse fibroblast cell lines. Small interfering RNA specific for HIF1α or HIF2α was transfected to study Epo expression in C3H10T1/2 cells. The effect of transforming growth factor-ß1 (TGF-ß1) on HIF-EPO axis was studied in C3H10T1/2 cells and mice. RESULTS: Similar to mouse REP pericytes, C3H10T1/2 cells differentiated to α-smooth muscle actin+ myofibroblasts after exposure to TGF-ß1. Specific HIF knockdown demonstrated the role of HIF2α in hypoxia-induced Epo expression. Sustained TGF-ß1 exposure increased neither DNA methyltransferase nor methylation of Epas1 and Epo genes. However, TGF-ß1 repressed HIF2α-encoding Epas1 promptly through activating activin receptor-like kinase-5 (ALK5), thereby decreasing Epo induction by hypoxia and prolyl hydroxylase domain inhibitor roxadustat. In mice with pro-fibrotic injury induced by ureteral obstruction, upregulation of Tgfb1 was accompanied with downregulation of Epas1 and Epo in injured kidneys and myofibroblasts, which were reversed by ALK5 inhibitor SB431542. CONCLUSION: C3H10T1/2 cells possessed the property of HIF2α-dependent Epo expression in REP pericytes. TGF-ß1 induced not only the transition to myofibroblasts but also a repressive effect on Epas1-Epo axis in C3H10T1/2 cells. The repressive effect of TGF-ß1 on Epas1-Epo axis was confirmed in REP pericytes in vivo. Inhibition of TGF-ß1-ALK5 signaling might provide a novel treatment to rescue EPO expression in REP pericytes of injured kidney.

Treating toxic epidermal necrolysis with systemic immunomodulating therapies: A systematic review and network meta-analysis.

BACKGROUND: Various systemic immunomodulating therapies have been used to treat toxic epidermal necrolysis (TEN), but their efficacy remains unclear. OBJECTIVE: To perform a systematic review and network meta-analysis (NMA) evaluating the effects of systemic immunomodulating therapies on mortality for Stevens-Johnson syndrome (SJS)/TEN overlap and TEN. METHODS: A literature search was performed in online databases (from inception to October 31, 2019). Outcomes were mortality rates and Score of Toxic Epidermal Necrolysis (SCORTEN)-based standardized mortality ratio (SMR). A frequentist random-effects model was adopted. RESULTS: Sixty-seven studies involving 2079 patients were included. An NMA of 10 treatments showed that none was superior to supportive care in reducing mortality rates and that thalidomide was associated with a significantly higher mortality rate (odds ratio, 11.67; 95% confidence interval [CI], 1.42-95.96). For SMR, an NMA of 11 treatment arms showed that corticosteroids and intravenous immunoglobulin combination therapy was the only treatment with significant survival benefits (SMR, 0.53; 95% CI, 0.31-0.93). LIMITATIONS: Heterogeneity and a paucity of eligible randomized controlled trials. CONCLUSIONS: Combination therapy with corticosteroids and IVIg may reduce mortality risks in patients with SJS/TEN overlap and TEN. Cyclosporine and etanercept are promising therapies, but more studies are required to provide clearer evidence.

[Roles of Cilia in Heart Development and Congenital Heart Disease].

Cilia are protruding cell structures on the cell surface and are found in almost every type of cell.According to the different structures and quantity of tubulins,cilia can be divided into two categories:motor cilia and sensory cilia.Sensory cilia are also called non-motor cilia and primary cilia,due to the composition and number of tubulins.They are closely related to the development of internal organs and many human physiological activities.Recent studies have demonstrated that cilia are involved in regulating the formation of left and right symmetry of the heart structure,and eventually the heart develops into the left-right asymmetry structures.Since congenital heart diseases(CHD)are characterized by abnormalities in the spatial structure of the heart chamber and outflow tract,cilia may play an important role in the pathogenesis of CHD.Cilia,mainly through ciliary transduction signal pathways,regulate both the formation of left and right asymmetrical structures and the polarity and the migration of cells.Therefore,a clear understanding of the regulation mechanism of ciliary signaling pathway on heart development can provide new therapeutic targets and new ideas for the clinical treatment of CHD and may offer new target genes for prenatal screening of CHD.This article summarizes recent advances in the role of cilia in heart development and CHD pathogenesis and its mechanisms.

A longitudinal, cross-lagged panel analysis of loneliness and depression among community-based older adults.

In the present study, we intended to examine the temporal association between loneliness and depression among community-based older adults. We analyzed data on 3,920 persons with a mean age of 67.6 years at baseline from the Taiwan Longitudinal Study on Aging. Structural equation modeling was used to investigate the temporal association between loneliness and depression over a period of 14 years. The results showed that the temporal association between loneliness and depression was bidirectional but stronger and more robust for depression as the initial symptom. Loneliness at Time 1 and 3, respectively, significantly predicted depression at Time 2 and 4. Depression at each time point had a significant effect on subsequent loneliness, even considering covariates. Future prevention programs for older adults with depression should also target at dealing with their loneliness, and vice versa. This study also highlights the need to assess and to manage the two symptoms simultaneously.

Inhibition of Src Homology 2 Domain-Containing Protein Tyrosine Phosphatase-2 Facilitates CD31hiEndomucinhi Blood Vessel and Bone Formation in Ovariectomized Mice.

BACKGROUND/AIMS: Recently, we and others showed that the relative abundance of a specific vessel subtype, strongly positive for CD31 and Endomucin (CD31hiEmcnhi), is associated with bone formation and bone loss, and platelet-derived growth factor-BB (PDGF-BB) secreted by preosteoclasts induces the formation of the specific vessels and thereby stimulates osteogenesis. Inhibition of Src homology 2 domain-containing protein tyrosine phosphatase-2 (SHP-2) has been shown to block the fusion of preosteoclasts into mature osteoclasts. However, it is unclear whether inhibition of SHP-2 could promote preosteoclast-induced angiogenesis and then enhance bone formation. This study aimed to determine the effects of a specific SHP-2 inhibitor (NSC-87877) on CD31 hiEmcnhi vessel and bone formation. METHODS: 3-month-old C57BL/6 mice were subjected to either ovariectomy (OVX) or sham operation. OVX mice were intraperitoneally injected with NSC-87877 and the control (sham) mice were treated with an equal volume of diluents (PBS). Two months later, bone samples from mice were collected for µCT, histological, immunohistochemical and immunofluorescent analyses to assess bone mass, osteogenic and osteoclastic acitivities, as well as the densities of CD31hiEmcnhi vessels. A series of angiogenesis- related assays were performed to test the effects of NSC-87877 on the pro-angiogenic activities of preosteoclasts in vitro. RESULTS: We found that NSC-87877 is sufficient to induce bone-sparing effects in OVX-induced osteoporotic mouse model. We also found that NSC-87877 induces higher numbers of preosteoclasts and CD31hiEmcnhi vessels and higher levels of PDGF-BB in bone marrow of osteoporotic mice. In vitro assays showed that NSC-87877 prevents preosteoclast fusion, increases PDGF-BB production, and augments the pro-angiogenic abilities of preosteoclasts. CONCLUSION: Our results suggest that NSC-87877 can be used as a promising therapeutic agent for osteoporosis by inhibiting osteoclast formation and promoting preosteoclast-induced angiogenesis.

Dual trajectories of breakfast eating and fruit and vegetable intake over a 5-year follow-up period among economically disadvantaged children: Gender differences.

Breakfast eating (BE) seems to be cross-sectionally associated with fruit and vegetable intake (FVI). To date, gender differences in any codevelopment between BE and FVI, as well as their associated factors, have not been examined. The objectives of this study were (1) to identify dual trajectories of BE and FVI among economically disadvantaged boys and girls; and (2) to examine potential associated factors of identified dual trajectories by gender. Children from economically disadvantaged families were enrolled in this prospective multicity study of the Taiwan Database of Children and Youth in Poverty between July 6 and October 31, 2009 and followed up biannually (2009, 2011, and 2013). One thousand one children (50.2% girls, mean ages at each time point being 9.1, 11.2 and 13.1 years, respectively; 49.8% boys, 9.0, 11.0 and 13.0 years) who completed at least two of the three assessments were included. Dual trajectories of BE and FVI over a 5-year follow-up period were identified as the outcome variables of interest by using mainly group-based dual trajectory modeling. Nine potential associated factors were then examined using logistic regression models. Two distinct dual trajectories of BE and FVI were identified among the girls: longitudinally irregular (68.8%) and shift to irregular (31.2%). Two distinct dual trajectories of BE and FVI were identified among the boys: longitudinally irregular (90.2%) and consistently regular (9.8%). Age was the significantly associated factor for boys. The findings confirmed a heterogeneous codevelopment between BE and FVI that may indicate different underlying mechanisms. Most children with a longitudinally irregular BE pattern had a similar pattern of FVI. Future research should comprehensively explore the gender differences in the determinants of codevelopment between BE and FVI.

Exploring Individual, Family, and Extrafamilial Factors Associated With Depression Among Elderly Residents of Care Settings.

This study investigated simultaneously the associations among individual, family, and extrafamilial factors and depression among elderly residents of care settings in Taiwan. The data for this study were obtained from the Vulnerability and Social Exclusion among Different Groups of Disadvantaged Elderly in an Aging Society: Phenomena and Strategies (1/2) project, which was conducted in Taipei City and Taipei County in 2007. We applied multiple regression procedures to a sample of 327 residents of care settings (48.3% women) who were mild physical impairment or physically independent and cognitively clear for determining factors associated with depression and their cumulative effects. We discovered that 24.5% of the residents were depressed. Physical mobility, number of chronic diseases, and self-assessed health status were significantly associated factors in all models. In the final model, we determined that one third of extrafamilial factors were significantly associated with depression, after controlling for all other variables. In addition, we observed an overall trend of increased mean scores of depression with an increase in the number of risk factors. The results imply that interventions aimed at preventing depression in elderly persons living in care settings, particularly persons with multiple risk conditions such as impaired physical mobility and medical comorbidities, should be designed to include extrafamilial elements. Establishing strong connections between elderly care setting residents and the institutional and neighborhood environments can help prevent depression.

[Diagnostic value of endogenous morphine in childhood sepsis].

OBJECTIVE: To investigate the plasma concentration of endogenous morphine and the value of endogenous morphine in predicting shock, death, and multiple organ dysfunction syndrome (MODS) in children with sepsis. METHODS: A total of 31 children with sepsis who met the diagnostic criteria were enrolled. According to the presence or absence of shock, they were divided into non-shock group with 19 children and shock group with 12 children. According to the outcome, they were divided into survival group with 22 children and death group with 9 children. According to the presence or absence of MODS, they were divided into non-MODS group with 13 children and MODS group with 18 children. In addition, 16 children with common infection and 31 who underwent physical examination were enrolled as controls. High-performance liquid chromatography-mass spectrometry was used to measure the plasma concentration of endogenous morphine. The receiver operating characteristic (ROC) curve was used to evaluate the value of endogenous morphine in predicting shock, death, and MODS in children with sepsis. RESULTS: No endogenous morphine was detected in the healthy control group. Endogenous morphine was detected in 3 children from the common infection group and in all of 31 children with sepsis. The shock group had a significantly higher plasma concentration of endogenous morphine than the non-shock group (P<0.05). The death group had a significantly higher plasma concentration of endogenous morphine than the survival group (P<0.05). The MODS group had a significantly higher plasma concentration of endogenous morphine than the non-MODS group (P<0.05). The ROC curve showed that endogenous morphine had certain value in predicting shock, death, and MODS in children with sepsis (P<0.05). CONCLUSIONS: There is a significant increase in the plasma concentration of endogenous morphine in children with sepsis, and endogenous morphine has a good value in predicting the risk of shock, death, and MODS.

[Tranilast inhibits myocardial fibrosis in mice with viral myocarditis].

OBJECTIVE: To investigate the effect of tranilast on myocardial fibrosis in mice with viral myocarditis (VMC). METHODS: Male balb/c mice (n=72) were randomly divided into control, VMC and tranilast groups (n=24 each). In the VMC and tranilast groups, the mice were infected with Coxsackie virus B3 (CVB3) to prepare VMC model, while the control group was treated with Eagle's medium. After modeling, the tranilast group was administrated with tranilast [200 mg/(kg.d)] until the day before sampling. On days 7, 14 and 28 after CVB3 or Eagle's medium infection, heart specimens (n=8) were taken and examined after Toluidine blue staining and Nissl staining for counts of mast cells (MC), hematoxylin-eosin staining for myocardial pathological changes, and Masson staining for myocardial fibrosis. The expression of CTGF and type I collagen (Col I) in the myocardial tissue was measured by RT-PCR and Western blot. The correlations of CTGF mRNA expression with MC counts and Col I expression were analyzed. RESULTS: The myocardial pathological changes and collagen volume fraction in the VMC group were significantly higher than in the control group at all three time points (P<0.05). Tranilast treatment significantly decreased the myocardial pathological changes and collagen volume fraction compared with the VMC group (P<0.05). The mRNA and protein expression of CTGF and Col I increased in the VMC group compared with the control group, and the increases were reduced with tranilast treatment (P<0.05). The number of MC was positively correlated to CTGF mRNA expression on the 7th day and 14th day (r=0.439, P=0.049) in the VMC group. There were positive correlations between the mRNA expression of Col I and CTGF on the 7th day and 14th day (r=0.646, P=0.007) and the 28th day (r=0.326, P=0.031). CONCLUSIONS: Tranilast may inhibit the aggregation of MC and down-regulate the expression of CTGF, relieving myocardial fibrosis of mice with VMC.

Covalent small ubiquitin-like modifier (SUMO) modification of Maf1 protein controls RNA polymerase III-dependent transcription repression.

RNA polymerase (pol) III transcribes genes that determine biosynthetic capacity. Induction of these genes is required for oncogenic transformation. The transcriptional repressor, Maf1, plays a central role in the repression of these and other genes that promote oncogenesis. Our studies identify an important new role for SUMOylation in repressing RNA pol III-dependent transcription. We show that a key mechanism by which this occurs is through small ubiquitin-like modifier (SUMO) modification of Maf1 by both SUMO1 and SUMO2. Mutation of each lysine residue revealed that Lys-35 is the major SUMOylation site on Maf1 and that the deSUMOylase, SENP1, is responsible for controlling Maf1K35 SUMOylation. SUMOylation of Maf1 is unaffected by rapamycin inhibition of mammalian target of rapamycin (mTOR) and mTOR-dependent Maf1 phosphorylation. By preventing SUMOylation at Lys-35, Maf1 is impaired in its ability to both repress transcription and suppress colony growth. Although SUMOylation does not alter Maf1 subcellular localization, Maf1K35R is defective in its ability to associate with RNA pol III. This impairs Maf1 recruitment to tRNA gene promoters and its ability to facilitate the dissociation of RNA pol III from these promoters. These studies identify a novel role for SUMOylation in controlling Maf1 and RNA pol III-mediated transcription. Given the emerging roles of SENP1, Maf1, and RNA pol III transcription in oncogenesis, our studies support the idea that deSUMOylation of Maf1 and induction of its gene targets play a critical role in cancer development.

Inhibition of Notch signaling facilitates the differentiation of human-induced pluripotent stem cells into neural stem cells.

Neural stem cells (NSCs) derived from induced pluripotent stem cells (iPSCs) are becoming an appealing source of cell-based therapies of brain diseases. As such, it is important to understand the molecular mechanisms that regulate the differentiation of iPSCs toward NSCs. It is well known that Notch signaling governs the retention of stem cell features and drives stem cells fate. However, further studies are required to investigate the role of Notch signaling in the NSCs differentiation of iPSCs. In this study, we successfully generated NSCs from human iPSCs using serum-free medium supplemented with retinoic acid (RA) in vitro. We then assessed changes in the expression of Notch signaling-related molecules and some miRNAs (9, 34a, 200b), which exert their regulation by targeting Notch signaling. Moreover, we used a γ-secretase inhibitor (DAPT) to disturb Notch signaling. Data revealed that the levels of the Notch signaling-related molecules decreased, whereas those miRNAs increased, during this differentiation process. Inhibition of Notch signaling accelerated the formation of the neural rosette structures and the expression of NSC and mature neurocyte marker genes. This suggests that Notch signaling negatively regulated the neuralization of human iPSCs, and that this process may be regulated by some miRNAs.

The effects of social structure and social capital on changes in smoking status from 8th to 9th grade: results of the Child and Adolescent Behaviors in Long-term Evolution (CABLE) study.

OBJECTIVE: Social structure and social capital are important variables for public health strategies seeking to prevent smoking among adolescents. The purpose of this study was to examine the relationships between social structure, social capital and changes in smoking status from the 8th to 9th grade in Taiwan. METHODS: Data were obtained from the Child and Adolescent Behaviors in Long-term Evolution (CABLE) project. The study analyzed a final sample of 1937 students (50.7% female). RESULTS: Each layer of social structure was associated with a particular form of social capital. Students whose parents were married and living together had higher family social capital. After controlling for background variables, the social structure variable of friends who smoke was significantly associated with changes in smoking status. Students reporting more school attachment were less likely to start smoking. Students with higher parental supervision was associated with less chance of being a consistent smoker, whereas participation of social organization outside of school was associated with continued smoking. Attending school club was associated with higher probability of smoking cessation. CONCLUSION: Smoking prevention and intervention strategies aimed at junior high school students should be tailored to the particular form of social capital important for each type of smoking status.

[Effect of tranilast on myocardial fibrosis in mice with viral myocarditis].

OBJECTIVE: To study the role of tranilast in the pathogenesis of myocardiac fibrosis in viral myocarditis. METHODS: Seventy-two BALB/C mice were randomly divided into control, model and intervention groups (n=24 each). Mice in the model and intervention groups were infected with Coxsackievirus B3 to induce viral myocarditis. The intervention group was given with tranilast (200 mg/kg) by gavage until sacrifice for sampling, while the other two groups were administered with the same volume of normal saline. Cardiac tissues were obtained from 8 mice on 7, 14 and 28 days after modeling. The mast cell number was observed by toluidine blue staining and thionine staining. The cardiac tissues were stained with hematoxylin and eosin as well as masson trichrome to observe the pathological changes in cardiac tissues. The mRNA and protein expression of osteopontin and transforming growth factor-ß1 was measured by RT-PCR and immunohistochemistry respectively. RESULTS: In the model group, the mRNA and protein expression of osteopontin reached the highest level on the 7th day, decreasing from the 14th day, and became to the least on the 28th day; while the expression of TGF-ß1 increased from the 7th day, reaching a peak on the 14th day, and decreased slightly on the 28th day. The mRNA and protein expression of TGF-ß1 and OPN was lower in the intervention group than the model group (P<0.05), but higher than the control group (P<0.05). The expression of OPN mRNA was positively correlated to the number of mast cells. CONCLUSIONS: Tranilast can reduce myocardial fibrosis by decreasing the number of mast cells, inhibiting the expression of TGF-ß1 and OPN.

Intermittent Fasting Targets Osteocyte Neuropeptide Y to Relieve Osteoarthritis.

Osteoarthritis is a highly prevalent progressive joint disease that still requires an optimal therapeutic approach. Intermittent fasting is an attractive dieting strategy for improving health. Here this study shows that intermittent fasting potently relieves medial meniscus (DMM)- or natural aging-induced osteoarthritic phenotypes. Osteocytes, the most abundant bone cells, secrete excess neuropeptide Y (NPY) during osteoarthritis, and this alteration can be altered by intermittent fasting. Both NPY and the NPY-abundant culture medium of osteocytes (OCY-CM) from osteoarthritic mice possess pro-inflammatory, pro-osteoclastic, and pro-neurite outgrowth effects, while OCY-CM from the intermittent fasting-treated osteoarthritic mice fails to induce significant stimulatory effects on inflammation, osteoclast formation, and neurite outgrowth. Depletion of osteocyte NPY significantly attenuates DMM-induced osteoarthritis and abolishes the benefits of intermittent fasting on osteoarthritis. This study suggests that osteocyte NPY is a key contributing factor in the pathogenesis of osteoarthritis and intermittent fasting represents a promising nonpharmacological antiosteoarthritis method by targeting osteocyte NPY.

[Roles of cardiac mast cells and Toll-like receptor 4 in viral myocarditis among mice].

OBJECTIVE: To investigate the role and significance of cardiac mast cells and Toll-like receptor 4 (TLR4) in the development and progression of viral myocarditis (VMC). METHODS: Forty-eight Balb/c mice were randomly divided into a control group (n=24) and a model group (n=24). Coxsackievirus B3 was intraperitoneally injected into the model group mice to establish a VMC model. In each group, cardiac tissues were collected from 8 mice at 7, 14 and 28 days after the model was established. The cardiac tissues were stained with hematoxylin and eosin as well as Masson trichrome to observe pathological changes in cardiac tissues. The number and degranulation of cardiac mast cells at each time point were measured and evaluated by toluidine blue staining and transmission electron microscopy. The mRNA and protein expression of TLR4 in cardiac tissues was measured by RT-PCR and immunohistochemistry. In the model group, the correlation between number of cardiac mast cells and mRNA expression of TLR4 at all time points was analyzed. RESULTS: The model group had significantly higher pathological scores of cardiac tissues than the control group at all time points (P<0.05). The myocardial collagen volume fraction in the model group at 28 days was significantly higher than in the control group at all time points and higher than in the model group at 7 and 14 days (P<0.05). At each time point, the model group had a significantly increased number of mast cells (P<0.05), and significantly increased mRNA and protein expression of TLR4 (P<0.05) compared with the control group. In the model group, the number of cardiac mast cells was positively correlated with the mRNA expression of TLR4 at all time points (R²=0.877, P<0.05). CONCLUSIONS: Mice with VMC have significantly increased numbers of cardiac mast cells and expression of TLR4 compared with control mice at all time points, suggesting that mast cells and TLR4 may play important roles in the inflammatory response and fibrosis of VMC.