Project description:Preterm birth, defined as delivery before the 37th week of gestation, is the most common cause of neonatal mortality and the second leading cause of death in children under five years of age. Preterm birth is associated with immediate and long term morbidity as well as growth and developmental delay. The lack of access to human myometrial samples during ongoing uncomplicated pregnancy seriously hampers proper understanding of the sequence of events leading to parturition initiation. In our previous work we used mouse as a model and profiled gene expression in mouse uterus from early E6.5 to late gestation E17.5. We identified Tbx2 as one of the putative upstream regulators during mid-gestation (E10.5, E12.5, E15.5). The role of TBX2 in human myometrium has not been investigated. In this study we identify the gene targets of TBX2 by overexpressing TBX2 in cultured telomerase immortalised myometrial cells followed by gene expression profiling using microarrays.
Project description:Circulating progesterone (P4) levels decline before the onset of parturition in most animals, but not in humans. This has led to the suggestion that there is functional withdrawal of P4 action at the myometrial level prior to labor onset. Mifepristone is widely used to induce human labour In this study, we aimed to establish and validate a model of human myometrial explants for the study of P4 action. Myometrial biopsies obtained at Caesearean section at term were dissected into explants after a portion was immediately snap-frozen (t=0). Transcriptomic comparison of paired explants and primary myometrial cells as well as the hTert immortalized myometrial cell line demonstrated that explants more closely resemble t=0. Biopsies obtained from non-laboring women at elective Caesarean section at term were divided into 3: (i) dissected and immediately snap-frozen (t=0), (ii) dissected into 3x3x3mm3myometrial explants and (iii) processed for primary cell culture. Explants, primary cells at passage 4 (the typical passage our group uses for experiments) and hTERT cells were cultured for a period of 30 hours without treatment. Total RNA was extracted and microarray analysis performed. 6 replicates were used for this study.
Project description:Circulating progesterone (P4) levels decline before the onset of parturition in most animals, but not in humans. This has led to the suggestion that there is functional withdrawal of P4 action at the myometrial level prior to labor onset. Mifepristone is widely used to induce human labour In this study, we aimed to establish and validate a model of human myometrial explants for the study of P4 action. Myometrial biopsies obtained at Caesearean section at term were dissected into explants after a portion was immediately snap-frozen (t=0). Transcriptomic comparison of paired explants and primary myometrial cells as well as the hTert immortalized myometrial cell line demonstrated that explants more closely resemble t=0.
Project description:During pregnancy, the myometrium remains quiescent but at term, switches to a state capable of producing a series of coordinated contractions for the delivery of the fetus. Myometrial contractions of labour signify the normal physiological end-point of pregnancy but the biochemical onset of labour may occur at or before term via a series of changes in expression of labour associated genes that are responsible for controlling the activity of the uterus during pregnancy and parturition. There is increasing evidence that components of the cAMP-signalling pathway are up-regulated in the human myometrium during pregnancy to promote the relaxation of the myometrium until term. Our aim was to determine which cAMP-associated genes are important during pregnancy and parturition by exposing myometrial cells to forskolin and performing an a gene array. We then plan to study the trend of the cAMP-associated genes at different stages of gestation and during labour. In this study, we used microarrays to elucidate forskolin responsive genes in human myometrium. These data may provide a broader view of gene networks and cellular functions regulated by forskolin in human myometrial cells. In our future study, this will also help us understand the role of cAMP in human parturition. Primary cultures of human myometrial cells were grown from myometrial biopsies obtained at the time of elective caesarean section at term. Cells were exposed to forskolin (100 µM) for 48 hours, and then total RNA were extracted from each culture. Two comparisons were carried out including: 1. Control 2. Forksolin
Project description:During pregnancy, the myometrium remains quiescent but at term, switches to a state capable of producing a series of coordinated contractions for the delivery of the fetus. Myometrial contractions of labour signify the normal physiological end-point of pregnancy but the biochemical onset of labour may occur at or before term via a series of changes in expression of labour associated genes that are responsible for controlling the activity of the uterus during pregnancy and parturition. There is increasing evidence that components of the cAMP-signalling pathway are up-regulated in the human myometrium during pregnancy to promote the relaxation of the myometrium until term. Our aim was to determine which cAMP-associated genes are important during pregnancy and parturition by exposing myometrial cells to forskolin and performing an a gene array. We then plan to study the trend of the cAMP-associated genes at different stages of gestation and during labour. In this study, we used microarrays to elucidate forskolin responsive genes in human myometrium. These data may provide a broader view of gene networks and cellular functions regulated by forskolin in human myometrial cells. In our future study, this will also help us understand the role of cAMP in human parturition.
Project description:Atoh1 is essential for the development of both outer hair cells (OHCs) and inner hair cells (IHCs) in the mammalian cochlea. Whereas Ikzf2 is necessary for OHC development, the key gene required for IHC development remains unknown. We found that deletion of Tbx2 in neonatal IHCs led to their transdifferentiation into OHCs by repressing 26.7% of IHC genes and inducing 56.3% of OHC genes, including Ikzf2. More importantly, persistent expression of Tbx2 coupled with transient Atoh1 expression effectively reprogramed non-sensory supporting cells into new IHCs expressing the functional IHC marker vGlut3. The differentiation status of these new IHCs was considerably more advanced than that previously reported. Thus, Tbx2 is essential for IHC development, and co-upregulation of Tbx2 with Atoh1 in supporting cells represents a new approach for treating deafness related to IHC degeneration.
Project description:T-box (TBX) transcription factors are evolutionary conserved genes and master transcriptional regulators. In mammals, TBX2 subfamily (TBX2, TBX3, TBX4, and TBX5) genes are expressed in the developing lung bud and tracheae. Our group previously showed that the expression of TBX2 subfamily was significantly high in human normal lungs, but markedly suppressed in lung adenocarcinoma (LUAD). To further elucidate their role in LUAD pathogenesis, we first confirmed abundant expression of protein products of the four members by immunostaining in adult human normal lung tissues. We also found overall suppressed expression of these genes and their corresponding proteins in a panel of human LUAD cell lines. Transient over-expression of each of the genes in human (NCI-H1299), and mouse (MDA-F471) derived lung cancer cells was found to significantly inhibit growth and proliferation as well as induce apoptosis. Genome-wide transcriptomic analyses on NCI-H1299 cells, overexpressing TBX2 gene subfamily, unraveled novel regulatory pathways. These included, among others, inhibition of cell cycle progression but more importantly activation of the histone demethylase pathway. When using a pattern-matching algorithm, we showed that TBX's overexpression mimic molecular signatures from azacitidine treated NCI-H1299 cells which in turn are inversely correlated to expression profiles of both human and murine lung tumors relative to matched normal lung. In conclusion, we showed that the TBX2 subfamily genes play a critical tumor suppressor role in lung cancer pathogenesis through regulating its methylating pattern, making them putative candidates for epigenetic therapy in LUAD.
Project description:We report the high-throughput profiling of Tbx2 binding sites in mouse melanoma B16 cells. We generated B16 clones that have endogenous Tbx2 tagged with 3xHA, and used HA antibody for immunoprecipitation. This study provides a high-quality genome-wide Tbx2 binding profile and helps further understand Tbx2 role in melanoma progression
Project description:Despite being found in the notochord of several chordates, the roles of the Tbx2 subfamily of T-box transcription factors in the development of this tissue remain largely unknown. We explored the targets of the only Tbx2 subfamily member in Ciona intestinalis, Ci-Tbx2/3, by expressing mutant forms of the transcriptional regulator using the Ci-Bra promoter region. We produced a dominant interfering version of Ci-Tbx2/3 (Tbx2/3DBD) through expression of a truncated version consisting only of its DNA-binding domain (DBD) and a constitutive activator form by attaching the T-box of Ci-Tbx2/3 to the VP16 transactivation domain (Tbx2/3VP16). These constructs were introduced into 1-cell stage embryos and grown to the neurula (N) or mid-tailbud (mTb) stage to capture targets regulated throughout notochord morphogenesis. Ci-Tbx2/3 targets were ascertained using whole-genome custom Affymetrix microarrays to compare the transcription levels of Tbx2/3DBD and Tbx2/3VP16 expressing embryos to wild-type controls (Bra>GFP) at the neurula or mTb stages.