Project description:Choline transporter-like1 is required for plasmodesmal targeting of Potato leafroll virus movement protein MP17 and long-distance assimilate transport
Project description:Chondrocytes at different maturation states in the growth plate produce matrix vesicles (MVs), membrane organelles found in the extracellular matrix, with a wide range of contents, such as matrix processing enzymes and receptors for hormones. We have shown that MVs harvested from growth zone (GC) chondrocyte cultures contain abundant small RNAs, including miRNAs. Here, we determined whether RNA also exists in MVs produced by less mature resting zone (RC) chondrocytes and, if so, whether it differs from the RNA in MVs produced by GC cells. Our results showed that RNA, small RNA specifically, was present in RC-MVs, and it was well-protected from RNase by the phospholipid membrane. A group of miRNAs was enriched in RC-MVs compared RC-cells, suggesting that miRNAs are selectively packaged into MVs. High throughput array and RNA sequencing showed that ~39% miRNAs were differentially expressed between RC-MVs and GC-MVs. Individual RT-qPCR also confirmed that miR-122-5p and miR-150-5p were expressed at significantly higher levels in RC-MVs compared to GC-MVs. This study showed that growth plate chondrocytes at different differentiation stages produce different MVs with different miRNA contents, further supporting extracellular vesicle miRNAs play a role as “matrisomes” that mediate the cell–cell communication in cartilage and bone development.
Project description:Integrative genetic analysis identified FLVCR1 as a choline transporter in mammalian cells. We profilied the transcriptional response of HeLa cells with and without FLVCR1 to choline depeleted or replete conditions.
Project description:Gowth plate chondrocytes include heterogenous cell population and cellular diversity of these chondrocytes remains to be elucidated. We used single cell RNA sequencing to uncover the diverssity of growth plate chondrocytes and identify noel marker genes selectively expressed in pre-hypertrophic chondrocytes.
Project description:Here we show a multifunctional protein, Hnrnpk, is essential for preventing excessive apoptosis and premature differentiation of growth plate chondrocytes. These datas were the RNA-seq of E18.5 growth plate chondrocytes with or without Hnrnpk.
Project description:Bones at different anatomical locations vary dramatically in size. The mechanisms responsible for these size differences are poorly understood. Bone elongation occurs at the growth plates and advances rapidly in early life but then progressively slows due to a developmental program termed growth plate senescence. This developmental program includes declines in cell proliferation and hypertrophy, depletion of cells in all growth plate zones, and extensive underlying changes in the expression of growth-regulating genes. Here we use RNA-Seq to compare changes of gene expression with age in the longer bone (tibia, 1- vs 4-wk) with the difference of gene expression between long and short bones (tibia vs phalanx) at 1wk. We found that the developmental program of growth plate senescence is more advanced in the shorter bone and this differential senescence (or aging) underlies the disparities in bone length.
Project description:A variety of cell cultures models and in vivo approaches have been used to study gene expression during chondrocyte differentiation. The extent to which the in vitro models reflect bona fide gene regulation in the growth plate has not been quantified. In addition, studies that evaluate global gene expression changes among different growth plate zones are limited. To address these issues, we completed a microarray screen of three growth plate zones derived from manually segmented embryonic mouse tibiae. Classification of genes differentially expressed between each respective growth plate zone, functional categorization as well as characterization of gene expression patterns, cytogenetic loci, signaling pathways and functional motifs confirmed documented data and pointed to novel aspects of chondrocyte differentiation. Parallel comparisons of the microdissected tibiae data set to our previously completed micromass culture screen further corroborated the suitability of micromass cultures for modeling gene expression in chondrocyte development. The micromass culture system demonstrated striking similarities to the in vivo microdissected tibiae screen; however, the micromass system was unable to accurately distinguish gene expression differences in the hypertrophic and mineralized zones of the growth plate. These studies will allow us to better understand zone-specific gene expression patterns in the growth plate. Ultimately, this work will help define both the genomic context in which genes are expressed in the long bones and the extent to which the micromass culture system is able to recapitulate chondrocyte development in endochondral ossification. Keywords: Growth plate microdissection