245 research outputs found
Establishment of lal-/- myeloid lineage cell line that resembles myeloid-derived suppressive cells
Myeloid-derived suppressor cells (MDSCs) in mouse are inflammatory cells that play critical roles in promoting cancer growth and metastasis by directly stimulating cancer cell proliferation and suppressing immune surveillance. In order to facilitate characterization of biochemical and cellular mechanisms of MDSCs, it is urgent to establish an "MDSC-like" cell line. By cross breeding of immortomouse (simian virus 40 large T antigen transgenic mice) with wild type and lysosomal acid lipase (LAL) knock-out (lal-/-) mice, we have established a wild type (HD1A) and a lal-/- (HD1B) myeloid cell lines. Compared with HD1A cells, HD1B cells demonstrated many characteristics similar to lal-/- MDSCs. HD1B cells exhibited increased lysosomes around perinuclear areas, dysfunction of mitochondria skewing toward fission structure, damaged membrane potential, and increased ROS production. HD1B cells showed increased glycolytic metabolism during blockage of fatty acid metabolism to fuel the energy need. Similar to lal-/- MDSCs, the mTOR signal pathway in HD1B cells is overly activated. Rapamycin treatment of HD1B cells reduced ROS production and restored the mitochondrial membrane potential. HD1B cells showed much stronger immunosuppression on CD4+ T cell proliferation and function in vitro, and enhanced cancer cells proliferation. Knockdown of mTOR with siRNA reduced the HD1B cell ability to immunosuppress T cells and stimulate cancer cell proliferation. Therefore, the HD1B myeloid cell line is an "MDSC-like" cell line that can be used as an alternative in vitro system to study how LAL controls various myeloid cell functions
Transthyretin Stimulates Tumor Growth through Regulation of Tumor, Immune, and Endothelial Cells
Early detection of lung cancer offers an important opportunity to decrease mortality while it is still treatable and curable. Thirteen secretory proteins that are Stat3 downstream gene products were identified as a panel of biomarkers for lung cancer detection in human sera. This panel of biomarkers potentially differentiates different types of lung cancer for classification. Among them, the transthyretin (TTR) concentration was highly increased in human serum of lung cancer patients. TTR concentration was also induced in the serum, bronchoalveolar lavage fluid, alveolar type II epithelial cells, and alveolar myeloid cells of the CCSP-rtTA/(tetO)7-Stat3C lung tumor mouse model. Recombinant TTR stimulated lung tumor cell proliferation and growth, which were mediated by activation of mitogenic and oncogenic molecules. TTR possesses cytokine functions to stimulate myeloid cell differentiation, which are known to play roles in tumor environment. Further analyses showed that TTR treatment enhanced the reactive oxygen species production in myeloid cells and enabled them to become functional myeloid-derived suppressive cells. TTR demonstrated a great influence on a wide spectrum of endothelial cell functions to control tumor and immune cell migration and infiltration. TTR-treated endothelial cells suppressed T cell proliferation. Taken together, these 13 Stat3 downstream inducible secretory protein biomarkers potentially can be used for lung cancer diagnosis, classification, and as clinical targets for lung cancer personalized treatment if their expression levels are increased in a given lung cancer patient in the blood
Gene Profile of Myeloid-Derived Suppressive Cells from the Bone Marrow of Lysosomal Acid Lipase Knock-Out Mice
BACKGROUND: Lysosomal acid lipase (LAL) controls development and homeostasis of myeloid lineage cells. Loss of the lysosomal acid lipase (LAL) function leads to expansion of myeloid-derived suppressive cells (MDSCs) that cause myeloproliferative neoplasm. METHODOLOGY/PRINCIPAL FINDINGS: Affymetrix GeneChip microarray analysis identified detailed intrinsic defects in Ly6G(+) myeloid lineage cells of LAL knock-out (lal-/-) mice. Ingenuity Pathway Analysis revealed activation of the mammalian target of rapamycin (mTOR) signaling, which functions as a nutrient/energy/redox sensor, and controls cell growth, cell cycle entry, cell survival, and cell motility. Loss of the LAL function led to major alteration of large GTPase and small GTPase signal transduction pathways. lal-/- Ly6G(+) myeloid cells in the bone marrow showed substantial increase of cell proliferation in association with up-regulation of cyclin and cyclin-dependent kinase (cdk) genes. The epigenetic microenvironment was significantly changed due to the increased expression of multiple histone cluster genes, centromere protein genes and chromosome modification genes. Gene expression of bioenergetic pathways, including glycolysis, aerobic glycolysis, mitochondrial oxidative phosphorylation, and respiratory chain proteins, was also increased, while the mitochondrial function was impaired in lal-/- Ly6G(+) myeloid cells. The concentration of reactive oxygen species (ROS) was significantly increased accompanied by up-regulation of nitric oxide/ROS production genes in these cells. CONCLUSIONS/SIGNIFICANCE: This comprehensive gene profile study for the first time identifies and defines important gene pathways involved in the myeloid lineage cells towards MDSCs using lal-/- mouse model
Mediating Roles of Gratitude and Social Support in the Relation Between Survivor Guilt and Posttraumatic Stress Disorder, Posttraumatic Growth Among Adolescents After the Ya’an Earthquake
Objective: This study aims to examine the mediating roles of gratitude and social support in the relationship between survivor guilt and posttraumatic stress disorder (PTSD) as well as the relationship between survivor guilt and posttraumatic growth (PTG).Methods: The current study used self-report questionnaires to investigate 706 adolescent survivors of Lushan county three and a half years after the Ya’an earthquake. The structural equation model was used to evaluate the relations between survivor guilt, gratitude and social support in PTSD and PTG.Results: The results indicated that survivor guilt had a positive effect on both PTSD and PTG. Gratitude partly mediated the relation between survivor guilt and both PTSD and PTG; social support partly mediated the relation between survivor guilt and PTG but not PTSD as well as the relation between gratitude and PTG.Conclusion: Survivor guilt has a double-edged sword effect. Survivor guilt affects PTSD and PTG through gratitude, and it could affect PTG but not PTSD through social support. Gratitude decreases PTSD and increases PTG, whereas social support only increases PTG
Lower-Elementary Level School Pupils' Developmental Trajectories of Chinese Verbal Vocabulary Knowledge and Influential Factors
149 elementary school pupils were selected as the subjects for this study, to whom five tracking assessments
of their verbal vocabulary knowledge were given over a period of three years. In addition, a latent variable
growth model was adopted to explore grades 1-3 elementary school pupil’s developmental trajectory
for verbal Chinese vocabulary knowledge. The phonological awareness, homomorphic morpheme
awareness, compound morpheme awareness and family socioeconomic status (SES) on the students’
verbal vocabulary knowledge were also investigated. The ndings are: 1, grades 1-3 elementary school
pupils verbal Chinese vocabulary knowledge developmental trajectory shows a curvilinear form, of which
linear development is trended in the first two years, and as of the third year the developmental rate doubles
the previous two years, whereas individual di erences are remarkable in both the initial level and the
growth rate; 2, awareness of phonetics, homomorphic morphemes and complex morphemes as well as the
family socioeconomic status can be referred to for a positive forecast of the students’ initial level of verbal
vocabulary knowledge; 3, only the awareness of homomorphic morphemes and the family socioeconomic
status can be applied to a positive prediction of the students’ verbal vocabulary knowledge growth rate.
The Bright Side and the Dark Side of Hybrid Organic Inorganic Perovskites
The previously developed bistable amphoteric native defect (BAND) model is
used for a comprehensive explanation of the unique photophysical properties and
for understanding the remarkable performance of perovskites as photovoltaic
materials. It is shown that the amphoteric defects in donor (acceptor)
configuration capture a fraction of photoexcited electrons (holes) dividing
them into two groups: higher energy bright and lower energy dark electrons
(holes). The spatial separation of the dark electrons and the dark holes and
the k-space separation of the bright and the dark charge carriers reduce
electron hole recombination rates, emulating the properties of an ideal
photovoltaic material with a balanced, spatially separated transport of
electrons and holes. The BAND model also offers a straightforward explanation
for the exceptional insensitivity of the photovoltaic performance of
polycrystalline perovskite films to structural and optical inhomogeneities. The
blue-shifted radiative recombination of bright electrons and holes results in a
large anti-Stokes effect that provides a quantitative explanation for the
spectral dependence of the laser cooling effect measured in perovskite
platelets
The Relationship Between Morphological Awareness and Reading Comprehension Among Chinese Children
The present study examined the developmental relationship between morphological awareness and reading comprehension, using a 1-year longitudinal study with a sample of 439 Chinese-speaking students in Grades 1, 3, and 5, respectively. Children’s text reading and three components of morphological awareness: homophone awareness, homograph awareness and compounding awareness were measured. After controlling for word reading, vocabulary knowledge, IQ, rapid automatized naming and phonological awareness measured at the initial level, the structural equation modeling results indicated that children’s compounding awareness made a significant direct contribution to reading comprehension only from Grade 5 to 6. Children’s reading comprehension also made a unique contribution to compounding awareness from Grade 5 to 6. Thus a reciprocal relationship between compounding awareness and reading comprehension was found for Grade 5 to 6. Reading comprehension in Grades 3 and 5 predicted homophone awareness in Grades 4 and 6 were marginal significance, respectively, but initial homophone awareness did not predict later reading comprehension across grades. Furthermore, there no unique connection between homograph awareness and reading comprehension across grades. These findings suggest a dynamic relationship between different aspects of morphological awareness and reading comprehension in Chinese-speaking children across elementary school years
Homo- and Hetero-Dimers of CAD Enzymes Regulate Lignification and Abiotic Stress Response in Moso Bamboo
Lignin biosynthesis enzymes form complexes for metabolic channelling during lignification and these enzymes also play an essential role in biotic and abiotic stress response. Cinnamyl alcohol dehydrogenase (CAD) is a vital enzyme that catalyses the reduction of aldehydes to alcohols, which is the final step in the lignin biosynthesis pathway. In the present study, we identified 49 CAD enzymes in five Bambusoideae species and analysed their phylogenetic relationships and conserved domains. Expression analysis of Moso bamboo PheCAD genes in several developmental tissues and stages revealed that among the PheCAD genes, PheCAD2 has the highest expression level and is expressed in many tissues and PheCAD1, PheCAD6, PheCAD8 and PheCAD12 were also expressed in most of the tissues studied. Co-expression analysis identified that the PheCAD2 positively correlates with most lignin biosynthesis enzymes, indicating that PheCAD2 might be the key enzyme involved in lignin biosynthesis. Further, more than 35% of the co-expressed genes with PheCADs were involved in biotic or abiotic stress responses. Abiotic stress transcriptomic data (SA, ABA, drought, and salt) analysis identified that PheCAD2, PheCAD3 and PheCAD5 genes were highly upregulated, confirming their involvement in abiotic stress response. Through yeast two-hybrid analysis, we found that PheCAD1, PheCAD2 and PheCAD8 form homo-dimers. Interestingly, BiFC and pull-down experiments identified that these enzymes form both homo- and hetero- dimers. These data suggest that PheCAD genes are involved in abiotic stress response and PheCAD2 might be a key lignin biosynthesis pathway enzyme. Moreover, this is the first report to show that three PheCAD enzymes form complexes and that the formation of PheCAD homo- and hetero- dimers might be tissue specific
Homo- and Hetero-Dimers of CAD Enzymes Regulate Lignification and Abiotic Stress Response in Moso Bamboo
Lignin biosynthesis enzymes form complexes for metabolic channelling during lignification and these enzymes also play an essential role in biotic and abiotic stress response. Cinnamyl alcohol dehydrogenase (CAD) is a vital enzyme that catalyses the reduction of aldehydes to alcohols, which is the final step in the lignin biosynthesis pathway. In the present study, we identified 49 CAD enzymes in five Bambusoideae species and analysed their phylogenetic relationships and conserved domains. Expression analysis of Moso bamboo PheCAD genes in several developmental tissues and stages revealed that among the PheCAD genes, PheCAD2 has the highest expression level and is expressed in many tissues and PheCAD1, PheCAD6, PheCAD8 and PheCAD12 were also expressed in most of the tissues studied. Co-expression analysis identified that the PheCAD2 positively correlates with most lignin biosynthesis enzymes, indicating that PheCAD2 might be the key enzyme involved in lignin biosynthesis. Further, more than 35% of the co-expressed genes with PheCADs were involved in biotic or abiotic stress responses. Abiotic stress transcriptomic data (SA, ABA, drought, and salt) analysis identified that PheCAD2, PheCAD3 and PheCAD5 genes were highly upregulated, confirming their involvement in abiotic stress response. Through yeast two-hybrid analysis, we found that PheCAD1, PheCAD2 and PheCAD8 form homo-dimers. Interestingly, BiFC and pull-down experiments identified that these enzymes form both homo- and hetero- dimers. These data suggest that PheCAD genes are involved in abiotic stress response and PheCAD2 might be a key lignin biosynthesis pathway enzyme. Moreover, this is the first report to show that three PheCAD enzymes form complexes and that the formation of PheCAD homo- and hetero- dimers might be tissue specific
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