Epigenomic profiling of stem cells within the pilosebaceous unit identifies PRDM16 as a regulator of sebaceous gland homeostasis

AbstractThe epidermis consists of different compartments such as the hair follicle (HF), sebaceous gland (SG) and interfollicular epidermis (IFE), each containing distinct stem cell (SC) populations. However, with the exception of the SCs residing within the HF bulge, other epidermal SC populations remain less well understood. Here we used an epigenomic strategy that combines H3K27me3 ChIP-seq and RNA-seq profiling to identify major regulators of pilosebaceous unit (PSU) SC located outside the bulge. When applied to the bulk of PSU SC isolated from mouse skin our approach identified both previously known and potentially novel non-bulge PSU SC regulators. Among the latter, we found that PRDM16 was predominantly enriched within the Junctional Zone (JZ), which harbors SC that contribute to renewal of the upper HF and the SG. To investigate PRDM16 function in the PSU SC, we generated an epidermal-specific Prdm16 Knock-out mouse model (K14-Cre-Prdm16fl/fl). Notably, SG homeostasis was disturbed upon loss of PRDM16 resulting in enlarged SGs, and excessive sebum production, resembling some of the features associated with human acne and sebaceous hyperplasia. Importantly, PRDM16 is essential to shut down proliferation in differentiating sebocytes. Overall, our study provides a list of putative novel regulators of PSU SC outside the bulge and identifies PRDM16 as a major regulator of SG homeostasis.

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S1P1 Agonists for Use as Adjunct Mobilizing Agents

Blood ◽

10.1182/blood.v116.21.826.826 ◽

2010 ◽

Vol 116 (21) ◽

pp. 826-826 ◽

Cited By ~ 3

Author(s):

Nadia Harun ◽

Marilyn Thien ◽

Julius G Juarez ◽

Kenneth Francis Bradstock ◽

Linda J. Bendall

Keyword(s):

Stem Cells ◽

Hematopoietic Stem Cells ◽

Peripheral Blood ◽

Conflicts Of Interest ◽

Receptor Expression ◽

Hematopoietic Stem ◽

Knock Out ◽

S1p Receptor ◽

Knock Out Mouse

Abstract Abstract 826 Harvesting hematopoietic stem cells (HSC) mobilised into peripheral blood (PB) for transplantation is mediated through bone marrow (BM) retentive and egress factors. Factors that retain hematopoietic stem cells (HSC) in the BM are well defined, with CXCL12 and VCAM1 playing major roles. However, the factors involved in the egress of HSC from the BM into the peripheral blood (PB) are currently uncharacterised. Sphingosine-1-Phosphate (S1P) is a lymphoid organ egress factor for lymphocytes, mediated through the S1P1 receptor, which is also expressed on HSC. We hypothesised that S1P mediates the egress of HSC out of the BM and into the PB. Our laboratory used a number of different mouse models with various S1P levels or S1P receptor expression to elucidate the role of the S1P gradient between the BM and PB. Sphingosine kinase-1 knock-out (SK1KO) mice were utilized for their reduced PB S1P levels. A sphingosine lyase inhibitor 4′deoxypyridoxine (DOP) was used to increase BM S1P levels. Mice treated with FTY720 for 14h had suppressed S1P1 expression and an S1P1 conditional knock-out mouse was also generated by our group. Animals were also treated with S1P receptor agonists such as SEW2871. Mobilisation experiments, competitive repopulation assays and chemotaxis assays were performed utilizing the various models. Plasma from SK1KO mice had a reduced capacity to induce migration in haematopoietic progenitor cells (HPC), confirming the chemokine activity of S1P. Consistent with this, AMD3100 induced mobilization was inhibited in SK1KO mice and DOP treated mice, demonstrating the role of an S1P gradient in HPC mobilization. Mice treated with FTY720 significantly inhibited AMD3100, although not G-CSF, mediated mobilisation of HPC in mice. No HPC accumulation was detected in secondary lymphoid organs such as lymph nodes or spleen. Most importantly, FTY720 treatment reduced the number of transplantable HSC in the blood following AMD3100-mediated mobilisation using a competitive repopulation assay. Our laboratory also generated an S1P1 conditional knock-out mouse. When mobilised with AMD3100, these S1P1 knock-out animals displayed a marked reduction in HPC mobilisation compared to wild-type animals. Finally, the S1P1 agonist SEW2871 increased HPC mobilisation synergistically, by approximately 2 fold when combined with AMD3100, but not G-CSF. S1P supports the egress of HSC from the BM into the PB following inhibition of the CXCL12/CXCR4 axis. S1P1 conditional knock-out mice display a significantly reduced mobilising capacity. S1P receptor agonist, SEW2871, acts synergistically with AMD3100 to increase HPC mobilisation in vivo, raising the possibility that such a combination may increase the efficiency of HSC collection for transplantation purposes. Disclosures: No relevant conflicts of interest to declare.

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39. Ex-Vivo Therapy of Fabry Disease Using Gene-Modified Human Mesenchymal Stem Cells: Efficacy Study in a Knock-Out Mouse Model

Molecular Therapy ◽

10.1016/s1525-0016(16)42869-8 ◽

2002 ◽

Vol 5 (5) ◽

pp. S15 ◽

Cited By ~ 1

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Mouse Model ◽

Fabry Disease ◽

Ex Vivo ◽

Human Mesenchymal Stem Cells ◽

Efficacy Study ◽

Knock Out ◽

Knock Out Mouse

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Hair-raising stem cells confirmed in mouse skin

Nature ◽

10.1038/news040830-9 ◽

2004 ◽

Author(s):

Helen Pilcher

Keyword(s):

Stem Cells ◽

Mouse Skin

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Faculty Opinions recommendation of Loss of cone function without degeneration in a novel Gnat2 knock-out mouse.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732844281.793543803 ◽

2018 ◽

Author(s):

Gordon Fain

Keyword(s):

Knock Out ◽

Cone Function ◽

Knock Out Mouse

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Brain immune cells characterization in UCMS exposed P2X7 knock-out mouse

Brain Behavior and Immunity ◽

10.1016/j.bbi.2021.02.012 ◽

2021 ◽

Vol 94 ◽

pp. 159-174

Author(s):

Romain Troubat ◽

Samuel Leman ◽

Katleen Pinchaud ◽

Alexandre Surget ◽

Pascal Barone ◽

...

Keyword(s):

Immune Cells ◽

Knock Out ◽

Knock Out Mouse

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RNA-seq reveals correlations between cytoskeleton-related genes and the osteogenic activity of mesenchymal stem cells on strontium loaded titania nanotube arrays

Materials Science and Engineering C ◽

10.1016/j.msec.2021.111939 ◽

2021 ◽

Vol 122 ◽

pp. 111939

Author(s):

Tianxiao Han ◽

Peng Xue ◽

Shiying Ju ◽

Zutai Zhang ◽

Jianyu Zeng ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Nanotube Arrays ◽

Rna Seq ◽

Osteogenic Activity ◽

Titania Nanotube Arrays ◽

Titania Nanotube

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Identification of New Transcription Factors that Can Promote Pluripotent Reprogramming

Stem Cell Reviews and Reports ◽

10.1007/s12015-021-10220-z ◽

2021 ◽

Author(s):

Ping Huang ◽

Jieying Zhu ◽

Yu Liu ◽

Guihuan Liu ◽

Ran Zhang ◽

...

Keyword(s):

Stem Cells ◽

Transcription Factors ◽

Embryonic Stem Cells ◽

Rna Sequencing ◽

Human Urine ◽

Embryonic Stem ◽

Rna Seq ◽

Reprogramming Efficiency ◽

Yamanaka Factors ◽

Urine Cells

Abstract Background Four transcription factors, Oct4, Sox2, Klf4, and c-Myc (the Yamanka factors), can reprogram somatic cells to induced pluripotent stem cells (iPSCs). Many studies have provided a number of alternative combinations to the non-Yamanaka factors. However, it is clear that many additional transcription factors that can generate iPSCs remain to be discovered. Methods The chromatin accessibility and transcriptional level of human embryonic stem cells and human urine cells were compared by Assay for Transposase-Accessible Chromatin with high-throughput sequencing (ATAC-seq) and RNA sequencing (RNA-seq) to identify potential reprogramming factors. Selected transcription factors were employed to reprogram urine cells, and the reprogramming efficiency was measured. Urine-derived iPSCs were detected for pluripotency by Immunofluorescence, quantitative polymerase chain reaction, RNA sequencing and teratoma formation test. Finally, we assessed the differentiation potential of the new iPSCs to cardiomyocytes in vitro. Results ATAC-seq and RNA-seq datasets predicted TEAD2, TEAD4 and ZIC3 as potential factors involved in urine cell reprogramming. Transfection of TEAD2, TEAD4 and ZIC3 (in the presence of Yamanaka factors) significantly improved the reprogramming efficiency of urine cells. We confirmed that the newly generated iPSCs possessed pluripotency characteristics similar to normal H1 embryonic stem cells. We also confirmed that the new iPSCs could differentiate to functional cardiomyocytes. Conclusions In conclusion, TEAD2, TEAD4 and ZIC3 can increase the efficiency of reprogramming human urine cells into iPSCs, and provides a new stem cell sources for the clinical application and modeling of cardiovascular disease. Graphical abstract

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Nicotinamide promotes pancreatic differentiation through the dual inhibition of CK1 and ROCK kinases in human embryonic stem cells

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02426-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yumeng Zhang ◽

Jiaqi Xu ◽

Zhili Ren ◽

Ya Meng ◽

Weiwei Liu ◽

...

Keyword(s):

Stem Cells ◽

Cell Fate ◽

Human Embryonic Stem Cells ◽

Embryonic Stem ◽

Cell Fate Determination ◽

Rna Seq ◽

Pancreatic Cell ◽

Pancreatic Progenitor ◽

Pancreatic Progenitors ◽

Rock Inhibition

Abstract Background Vitamin B3 (nicotinamide) plays important roles in metabolism as well as in SIRT and PARP pathways. It is also recently reported as a novel kinase inhibitor with multiple targets. Nicotinamide promotes pancreatic cell differentiation from human embryonic stem cells (hESCs). However, its molecular mechanism is still unclear. In order to understand the molecular mechanism involved in pancreatic cell fate determination, we analyzed the downstream pathways of nicotinamide in the derivation of NKX6.1+ pancreatic progenitors from hESCs. Methods We applied downstream modulators of nicotinamide during the induction from posterior foregut to pancreatic progenitors, including niacin, PARP inhibitor, SIRT inhibitor, CK1 inhibitor and ROCK inhibitor. The impact of those treatments was evaluated by quantitative real-time PCR, flow cytometry and immunostaining of pancreatic markers. Furthermore, CK1 isoforms were knocked down to validate CK1 function in the induction of pancreatic progenitors. Finally, RNA-seq was used to demonstrate pancreatic induction on the transcriptomic level. Results First, we demonstrated that nicotinamide promoted pancreatic progenitor differentiation in chemically defined conditions, but it did not act through either niacin-associated metabolism or the inhibition of PARP and SIRT pathways. In contrast, nicotinamide modulated differentiation through CK1 and ROCK inhibition. We demonstrated that CK1 inhibitors promoted the generation of PDX1/NKX6.1 double-positive pancreatic progenitor cells. shRNA knockdown revealed that the inhibition of CK1α and CK1ε promoted pancreatic progenitor differentiation. We then showed that nicotinamide also improved pancreatic progenitor differentiation through ROCK inhibition. Finally, RNA-seq data showed that CK1 and ROCK inhibition led to pancreatic gene expression, similar to nicotinamide treatment. Conclusions In this report, we revealed that nicotinamide promotes generation of pancreatic progenitors from hESCs through CK1 and ROCK inhibition. Furthermore, we discovered the novel role of CK1 in pancreatic cell fate determination.

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