Transcription of a mutant collagen I gene is a cell type and stage-specific marker for odontoblast and osteoblast differentiation

Development ◽  
1990 ◽  
Vol 108 (4) ◽  
pp. 717-726
Author(s):  
M. Schwarz ◽  
K. Harbers ◽  
K. Kratochwil

The Mov13 allele of the mouse alpha 1(I) collagen gene carries a retroviral insert in its first intron and had been reported to be transcriptionally silent. We have recently shown, however, that this mutant gene is expressed in odontoblasts of transplanted teeth derived from homozygous and heterozygous carrier embryos. The expression of the Mov13 allele has now been followed throughout in vivo development of mandibular teeth and bone in heterozygous animals, by in situ hybridization with a probe that specifically recognizes transcripts of the mutant gene. We show that the onset of its transcription precisely coincides with the final differentiation of odontoblasts and the onset of dentinogenesis, i.e. on day E16 for the incisor and at birth for the first molar. The mutant allele is also transcribed in osteoblasts of mandibular bone, again starting precisely with the onset of osteogenesis (day E13/14). No other cells were seen to transcribe the mutant gene. By these criteria, transcription of the Mov13 allele constitutes a true differentiation marker for odontoblasts and osteoblasts. Expression of the mutant allele in these two specialized cell types, in contrast to its transcriptional block in all other mesodermal cells (‘fibroblasts’), suggests tissue-specific differences in the regulation of the alpha 1(I) collagen gene.

Development ◽  
1995 ◽  
Vol 121 (7) ◽  
pp. 2069-2077
Author(s):  
E.D. Newman-Smith ◽  
Z. Werb

Mouse embryos containing only maternal chromosomes (parthenotes) develop abnormally in vivo, usually failing at the peri-implantation stage. We have analyzed the development of parthenote embryos by using an inner cell mass (ICM) outgrowth assay that mimics peri-implantation development. ICMs from normal embryos maintained undifferentiated stem cells positive for stage-specific embryonic antigen-1 and Rex-1 while differentiating into a variety of cell types, including visceral endoderm-like cells and parietal endoderm cells. In contrast, ICMs from parthenotes failed to maintain undifferentiated stem cells and differentiated almost exclusively into parietal endoderm. This suggests that parthenote ICMs have a defect that leads to differentiation, rather than maintenance, of the stem cells, and a defect that leads to a parietal endoderm fate for the stem cells. To test the hypothesis that the ICM population is not maintained owing to a lack of proliferation of the stem cells, we investigated whether mitogenic agents were able to maintain the ICM population in parthenotes. When parthenote blastocysts were supplied with the insulin-like growth factor-1 receptor (Igf-1r) and insulin-like growth factor-2 (Igf-2), two genes not detectable in parthenote blastocysts by in situ hybridization, the ICM population was maintained. Similarly, culture of parthenote blastocysts in medium conditioned by embryonic fibroblasts and supplemented with the maternal factor leukemia inhibitory factor maintained the ICM population. However, once this growth factor-rich medium was removed, the parthenote ICM cells still differentiated predominantly into parietal endoderm.(ABSTRACT TRUNCATED AT 250 WORDS)


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Dmitry O Traktuev ◽  
Daniel N Prater ◽  
Aravind R Sanjeevaiah ◽  
Stephanie Merfeld-Clauss ◽  
Brian H Johnstone ◽  
...  

Introduction Both Endothelial progenitor cells (EPC) and adipose stromal cells (ASC) are under investigation as therapies for cardiovascular diseases. Both cell types are capable of modulating vascular assembly and are, thereby, capable of directly promoting revascularization of ischemic tissues. We have shown that EPC differentiate into endothelial cells to form small vessels, whereas ASC have pericytic properties and naturally stabilize vessels. In this study we tested the possibility that ASC would interact with EPC to assemble de novo vessels in collagen in an in vivo chimeric implant. Methods and Results Collagen implants embedded with either umbilical cord blood EPC or adult ASC or a 4:1 mixture of both (2x10 6 cells/ml) were implanted subcutaneously into NOD/SCID mice. After 14 d implants were harvested and evaluated by immunohistochemistry. There was a pronounced difference among the groups in vascular network assembly. The majority of vessels formed in the EPC and ASC monocultures were small capillaries bounded by a single endothelial layer. Conversely, 100% of the plugs embedded with both cell types were highly invaded with multilayered arteriolar vessels. The density of the CD31 + vessels in the EPC and co-culture plugs was 26.6 ± 5.8 and 122.4 ± 9.8 per mm 2 , respectively. No CD31 + cells of human origin were detected in the ASC monocultures, indicating that ASC, which do not express this EC-specific marker, engage murine EC or form pseudovessels in this system. The density of α-SMA + vessels with lumens per mm 2 was 13.1 ± 3.6 (EPC), 10.2 ± 3.5 (ASC) and 124.7 ± 19.7 (co-culture). The total overlap of CD31 + and SMA + vessels demonstrates that mature, multilayered conduits were formed with the co-culture. Moreover, the majority of these vessels were filled with erythrocytes (92.5 ± 16.2 per mm 2 ), indicating inosculation with the native vasculature, which was confirmed by ultrasound with echogenic microbubbles and persisted to at least 4 months. Conclusion This study is the first to demonstrate that non-transformed human EPC and ASC cooperatively form mature and stable vasculature with subsequent functional integration into a host vasculature system.


1991 ◽  
Vol 71 (3) ◽  
pp. 939-944 ◽  
Author(s):  
B. Davis ◽  
H. C. Tseng

To investigate how central and peripheral nerves affect lysozyme secretion from tracheal submucosal glands in ferrets we injected substance P (20 nmol/kg in 200 microliters) intracisternally or intravenously into anesthetized artificially ventilated ferrets. We collected 3-ml samples from a perfused (3 ml/5 min) segment of trachea in situ during 15 min before and 45 min after injection of substance P. Content of lysozyme, a specific marker of tracheal submucosal gland serous cell secretion in ferrets, was measured spectrophotometrically in each sample. Intracisternal substance P increased peak lysozyme output threefold compared with baseline. This increase was abolished completely by cutting both superior laryngeal nerves (SLN) and was partially inhibited by atropine, phentolamine, or propranolol. Intravenous substance P increased peak lysozyme output 10-fold compared with baseline. This increase was partly abolished by cutting both SLN. We concluded that intracisternal substance P stimulated the central nervous system (CNS) and activated cholinergic, adrenergic, and nonadrenergic noncholinergic secretomotor nerves to tracheal glands and that intravenous substance P increased lysozyme secretion both by acting directly on tracheal glands and indirectly on the CNS to activate secretomotor nerves.


1993 ◽  
Vol 120 (2) ◽  
pp. 493-502 ◽  
Author(s):  
N A Wall ◽  
M Blessing ◽  
C V Wright ◽  
B L Hogan

DVR-6 (BMP-6 or Vgr-1) is a member of the TGF-beta superfamily of polypeptide signaling molecules. In situ hybridization studies have previously shown that DVR-6 RNA is expressed in a variety of cell types in the mouse embryo, but no information has been available on protein localization and biosynthesis. We have produced a polyclonal antibody to the proregion of DVR-6 and used it to localize the protein in whole mount and sectioned embryonic, newborn, and adult mouse tissues. DVR-6 protein is expressed in the mouse nervous system beginning at 9.5 days postcoitum (d.p.c.) and continues through adulthood. A variety of epithelial tissues also produce DVR-6 protein, including the suprabasal layer of the skin, bronchiolar epithelium, and the cornea. Additionally, a stably transfected cell line, BMGE+H/D6c4, is used to study the biosynthesis of DVR-6 protein and evidence is presented for translational regulation of DVR-6 expression.


Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1751 ◽  
Author(s):  
Rishikesh Kumar Gupta ◽  
Jacek Kuznicki

The present review discusses recent progress in single-cell RNA sequencing (scRNA-seq), which can describe cellular heterogeneity in various organs, bodily fluids, and pathologies (e.g., cancer and Alzheimer’s disease). We outline scRNA-seq techniques that are suitable for investigating cellular heterogeneity that is present in cell populations with very high resolution of the transcriptomic landscape. We summarize scRNA-seq findings and applications of this technology to identify cell types, activity, and other features that are important for the function of different bodily organs. We discuss future directions for scRNA-seq techniques that can link gene expression, protein expression, cellular function, and their roles in pathology. We speculate on how the field could develop beyond its present limitations (e.g., performing scRNA-seq in situ and in vivo). Finally, we discuss the integration of machine learning and artificial intelligence with cutting-edge scRNA-seq technology, which could provide a strong basis for designing precision medicine and targeted therapy in the future.


Science ◽  
2019 ◽  
Vol 366 (6461) ◽  
pp. 116-120 ◽  
Author(s):  
Nathan D. Lord ◽  
Thomas M. Norman ◽  
Ruoshi Yuan ◽  
Somenath Bakshi ◽  
Richard Losick ◽  
...  

Cell fate decision circuits must be variable enough for genetically identical cells to adopt a multitude of fates, yet ensure that these states are distinct, stably maintained, and coordinated with neighboring cells. A long-standing view is that this is achieved by regulatory networks involving self-stabilizing feedback loops that convert small differences into long-lived cell types. We combined regulatory mutants and in vivo reconstitution with theory for stochastic processes to show that the marquee features of a cell fate switch in Bacillus subtilis—discrete states, multigenerational inheritance, and timing of commitments—can instead be explained by simple stochastic competition between two constitutively produced proteins that form an inactive complex. Such antagonistic interactions are commonplace in cells and could provide powerful mechanisms for cell fate determination more broadly.


1996 ◽  
Vol 44 (11) ◽  
pp. 1215-1222 ◽  
Author(s):  
P J McMillan ◽  
J B Leverenz ◽  
P Poorkaj ◽  
G D Schellenberg ◽  
D M Dorsa

Mutations in the STM2 gene cause familial Alzheimer's disease (AD) in Volga Germans. To understand the function of this protein and how mutations lead to AD, it is important to determine which cell types in the brain express this gene. In situ hybridization histochemistry indicates that STM2 expression in the human brain is widespread and is primarily neuronal. In addition, STM2 mRNA is expressed in a cell line with neuronal origins. Quantification of the level of expression of the STM2 message in the basal forebrain, frontal cortex, and hippocampus reveals a significant decrease in AD-affected subjects compared to normal age-matched controls. These data suggest that downregulation of neuronal STM2 gene expression may be involved in the progression of AD.


2021 ◽  
Author(s):  
Nan He ◽  
Sirisha Thippabhotla ◽  
Cuncong Zhong ◽  
Zachary Greenberg ◽  
Liang Xu ◽  
...  

AbstractExtracellular vesicles (EVs), particularly exosomes, are emerging biomarker sources. However, due to heterogeneous populations secreted from diverse cell types, mapping EV multi-omic molecular information specifically to their pathogenesis origin for cancer biomarker identification is still extraordinary challenging. Herein, we introduced a novel 3D-structured nanographene immunomagnetic particles (NanoPoms) with unique flower pom-poms morphology and photo-click chemistry for specific marker-defined capture and release of intact small EVs. This specific EV isolation approach leads to the expanded identification of targetable cancer biomarkers with enhanced specificity and sensitivity, as demonstrated by multi-omic EV analysis of bladder cancer patient tissue fluids using the next generation sequencing of somatic DNA mutations, miRNAs, and the global proteome. The NanoPoms prepared sEVs also exhibit distinctive in vivo biodistribution patterns, highlighting the highly viable and integral quality. The developed method is simple and straightforward, and is applicable to nearly all types of biological fluids and amenable for scale up and high-throughput EV isolation.


2021 ◽  
Author(s):  
Atesh K Worthington ◽  
Taylor S Cool ◽  
Donna M Poscablo ◽  
Adeel Hussaini ◽  
Anna E Beaudin ◽  
...  

Traditional, adult-derived lymphocytes that circulate provide adaptive immunity to infection and pathogens. However, subsets of lymphoid cells are also found in non-lymphoid tissues and are called tissue-resident lymphoid cells (TLCs). TLCs encompass a wide array of cell types that span the spectrum of innate-to-adaptive immune function. Unlike traditional lymphocytes that are continuously generated from hematopoietic stem cells (HSCs), many TLCs are of fetal origin and poorly generated from adult HSCs. Here, we sought to understand the development of murine TLCs across multiple tissues and therefore probed the roles of Flk2 and IL7R⍺, two cytokine receptors with known roles in traditional lymphopoiesis. Using Flk2- and Il7r-Cre lineage tracing models, we found that peritoneal B1a cells, splenic marginal zone B (MZB) cells, lung ILC2s and regulatory T cells (Tregs) were highly labeled in both models. Despite this high labeling, highly quantitative, in vivo functional approaches showed that the loss of Flk2 minimally affected the generation of these cells in situ. In contrast, the loss of IL7R⍺, or combined deletion of Flk2 and IL7R⍺, dramatically reduced the cell numbers of B1a cells, MZBs, ILC2s, and Tregs both in situ and upon transplantation, indicating an intrinsic and more essential role for IL7Rα. Surprisingly, reciprocal transplants of WT HSCs showed that an IL7Rα-/- environment selectively impaired reconstitution of TLCs when compared to TLC numbers in situ. Taken together, our data revealed functional roles of Flk2 and IL7Rα in the establishment of tissue-resident lymphoid cells.


2021 ◽  
Author(s):  
Nan He ◽  
Sirisha Thippabhotla ◽  
Cuncong Zhong ◽  
Zachary Greenberg ◽  
Liang Xu ◽  
...  

Abstract Extracellular vesicles (EVs), particularly nano-sized small EV exosomes, are emerging biomarker sources. However, due to heterogeneous populations secreted from diverse cell types, mapping exosome multi-omic molecular information specifically to their pathogenesis origin for cancer biomarker identification is still extraordinarily challenging. Herein, we introduced a novel 3D-structured nanographene immunomagnetic particles (NanoPoms) with unique flower pom-poms morphology and photo-click chemistry for specific marker-defined capture and release of intact exosome. This specific exosome isolation approach leads to the expanded identification of targetable cancer biomarkers with enhanced specificity and sensitivity, as demonstrated by multi-omic exosome analysis of bladder cancer patient tissue fluids using the next generation sequencing of somatic DNA mutations, miRNAs, and the global proteome. The NanoPoms prepared exosomes also exhibit distinctive in vivo biodistribution patterns, highlighting the highly viable and integral quality. The developed method is simple and straightforward, which is applicable to nearly all types of biological fluids and amenable for enrichment, scale up, and high-throughput exosome isolation.


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