Project description:While the regulatory landscape during stem cell differentiation has been well characterized, the shared and unique regulatory mechanisms in different ectodermally-derived epithelial cells have not been well described. Through defining the complement of super enhancers and typical enhancers in corneal epithelium for the first time, we show that regulatory regions are often shared between cell types of the same lineage, and that corneal super enhancers are already marked as potential regulatory domains in embryonic stem cells. Through the enrichment of KLF motifs in enhancers, we identified and defined a novel role for Kruppel family member KLF7 in promoting the corneal progenitor cell state, in many cases working antagonistically to corneal differentiation promoting KLF4. Our work highlights the importance of balance between proliferation and differentiation, both for proper tissue development and for homeostasis.
Project description:While the regulatory landscape during stem cell differentiation has been well characterized, the shared and unique regulatory mechanisms in different ectodermally-derived epithelial cells have not been well described. Through defining the complement of super enhancers and typical enhancers in corneal epithelium for the first time, we show that regulatory regions are often shared between cell types of the same lineage, and that corneal super enhancers are already marked as potential regulatory domains in embryonic stem cells. Through the enrichment of KLF motifs in enhancers, we identified and defined a novel role for Kruppel family member KLF7 in promoting the corneal progenitor cell state, in many cases working antagonistically to corneal differentiation promoting KLF4. Our work highlights the importance of balance between proliferation and differentiation, both for proper tissue development and for homeostasis.
Project description:While the regulatory landscape during stem cell differentiation has been well characterized, the shared and unique regulatory mechanisms in different ectodermally-derived epithelial cells have not been well described. Through defining the complement of super enhancers and typical enhancers in corneal epithelium for the first time, we show that regulatory regions are often shared between cell types of the same lineage, and that corneal super enhancers are already marked as potential regulatory domains in embryonic stem cells. Through the enrichment of KLF motifs in enhancers, we identified and defined a novel role for Kruppel family member KLF7 in promoting the corneal progenitor cell state, in many cases working antagonistically to corneal differentiation promoting KLF4. Our work highlights the importance of balance between proliferation and differentiation, both for proper tissue development and for homeostasis.
Project description:Neurons in the central nervous system (CNS) lose their ability to regenerate early in development, but the underlying mechanisms are unknown. By screening genes developmentally regulated in retinal ganglion cells (RGCs), we identified Krüppel-like factor-4 (KLF4) as a transcriptional repressor of axon growth in RGCs and other CNS neurons. RGCs lacking KLF4 showed increased axon growth both in vitro and after optic nerve injury in vivo. Related KLF family members suppressed or enhanced axon growth to differing extents, and several growth-suppressive KLFs were up-regulated postnatally, whereas growth-enhancing KLFs were down-regulated. Thus, coordinated activities of different KLFs regulate the regenerative capacity of CNS neurons.
Project description:Analysis of change in transcriptosome after KLF4, KLF9, KLF11, KLF16 and KLF17 knockdown in hADSC. Analysis of effects of siRNA transfection (siCtrl, siKLF4, siKLF9, siKLF11, siKLF16 and siKLF17) in hADSC at gene expression level.The hypothesis tested in the present study was that different KLF members have distinctive roles in these cells.
Project description:Tissue-resident macrophages adopt distinct gene expression profiles and exhibit functional specialization based on their tissue of residence. Recent studies have begun to define the signals and transcription factors that induce these identities. Here we describe an unexpected and specific role for the broadly expressed transcription factor Krüppel-like factor 2 (KLF2) in the development of embryonically derived large cavity macrophages (LCMs) in the serous cavities. KLF2 not only directly regulates the transcription of genes previously shown to specify LCM identity, such as retinoic acid receptors and GATA6, but also is required for induction of many other transcripts that define the identity of these cells. Our results suggest that KLF4 may similarly regulate the identity of alveolar macrophages in the lung. These data demonstrate that broadly expressed transcription factors, such as group 2 KLFs, can play important roles in the specification of distinct identities of tissue-resident macrophages.
Project description:Krüppel-like factors (KLFs) are some kind of transcriptional regulator that regulates a broad range of cellular functions and has been linked to the development of certain malignancies. KLF expression patterns and prognostic values in colorectal cancer (CRC) have, however, been investigated rarely. To investigate the differential expression, predictive value, and gene mutations of KLFs in CRC patients, we used various online analytic tools, including ONCOMINE, TCGA, cBioPortal, and the TIMER database. KLF2-6, KLF8-10, KLF12-15, and KLF17 mRNA expression levels were dramatically downregulated in CRC tissues, but KLF1, KLF7, and KLF16 mRNA expression levels were significantly elevated in CRC tissues. According to the findings of Cox regression analysis, upregulation of KLF3, KLF5, and KLF6 and downregulation of KLF15 were linked with a better prognosis in CRC. For functional enrichment, our findings revealed that KLF members are involved in a variety of cancer-related biological processes. In colon cancer and rectal cancer, KLFs were also shown to be associated with a variety of immune cells. The findings of this research reveal that KLF family members' mRNA expression levels are possible prognostic indicators for patients with CRC.
Project description:miRNAs are endogenously expressed 18- to 25-nucleotide RNAs that regulate gene expression through translational repression by binding to a target mRNA. Recently, it has been indicated that miRNAs are closely related to osteogenesis. Our previous data suggested that miR-30 family members might be important regulators during the biomineralization process. However, whether and how they modulate osteogenic differentiation have not been explored. In this study, we demonstrated that miR-30 family members negatively regulate BMP-2-induced osteoblast differentiation by targeting Smad1 and Runx2. Evidentially, overexpression of miR-30 family members led to a decrease of alkaline phosphatase activity, whereas knockdown of them increased the activity. Then bioinformatic analysis identified potential target sites of the miR-30 family located in the 3' untranslated regions of Smad1 and Runx2. Western blot analysis and quantitative RT-PCR assays demonstrated that miR-30 family members inhibit Smad1 gene expression on the basis of repressing its translation. Furthermore, dual-luciferase reporter assays confirmed that Smad1 is a direct target of miR-30 family members. Rescue experiments that overexpress Smad1 and Runx2 significantly eliminated the inhibitory effect of miR-30 on osteogenic differentiation and provided strong evidence that miR-30 mediates the inhibition of osteogenesis by targeting Smad1 and Runx2. Also, the inhibitory effects of the miR-30 family were validated in mouse bone marrow mesenchymal stem cells. Therefore, our study uncovered that miR-30 family members are key negative regulators of BMP-2-mediated osteogenic differentiation.