Multipotent stem cells and their lineage-restricted progeny drive nephron formation within the developing kidney. Validated markers of these early stem/progenitor populations are essential for deciphering their in vivo function and for evaluating their clinical potential for treating adult kidney disease. Here, we document expression of the adult stem cell marker Lgr5 in the developing kidney and assess the stem/progenitor identity of Lgr5+ve cells via in vivo lineage tracing. The appearance and localization of Lgr5+ve cells coincided with that of the S-shaped body around E14. Lgr5 expression remained restricted to cell clusters within developing nephrons in the cortex until P7, when expression was permanently silenced. In vivo lineage tracing identified Lgr5 as a marker of a novel progenitor population within nascent nephrons dedicated to generating the thick ascending limb of Henle's loop and distal convoluted tubule. The Lgr5 surface marker and experimental models described here will be invaluable for deciphering the contribution of early nephron stem cells to developmental defects and for isolating human nephron progenitors as a prerequisite to evaluating their therapeutic potential.
Lgr5(+ve) stem/progenitor cells contribute to nephron formation during kidney development.
Specimen part
View SamplesTo assess the effect of activation of the unfolded protein response (UPR) in colon cancer cell lines, we treated cells with the AB5 subtilase cytotoxin (SubAB). This proteolytically cleaves the 78-kDa glucose-regulated protein (GRP78; also known as HSPA5 or BiP) inside the endoplasmic reticulum. We find that the WNT signaling pathway is highly affected upon treatment with SubAB.
ER stress causes rapid loss of intestinal epithelial stemness through activation of the unfolded protein response.
Specimen part, Cell line, Treatment
View SamplesProliferation of the self-renewing epithelium of the gastric corpus occurs almost exclusively in the isthmus of the glands, from where cells migrate bi-directionally towards pit and base. The isthmus is therefore generally viewed as the stem cell zone. We find that the stem cell marker Troy is expressed at the gland base by a small subpopulation of chief cells. By lineage tracing using a Troy-eGFP-ires-CreERT2 allele, single marked cells are shown to generate entirely labeled gastric units over periods of months. This phenomenon accelerates upon tissue damage. Troy+ chief cells can be cultured to generate long-lived gastric organoids. Troy marks a specific, 'plastic' subset of differentiated chief cells capable of replenishing entire gastric units, essentially serving as a quiescent reserve stem cell.
Differentiated Troy+ chief cells act as reserve stem cells to generate all lineages of the stomach epithelium.
Specimen part
View SamplesThe ubiquitous efflux transporter ATP-binding cassette sub-family C member 5 (ABCC5) is present at high levels in the blood-brain barrier, neurons and glia, but its in vivo substrates and function are not known. Untargeted metabolomic screens revealed that Abcc5-/- mice accumulate endogenous glutamate conjugates and analogs in several tissues, but brain in particular. The abundant neurotransmitter N-acetylaspartylglutamate (NAAG), for example, was over 2-fold higher in Abcc5-/- brain. In line with ABCC5-mediated transport, the metabolites that accumulated in Abcc5-/- tissues were depleted in cultured cells that overexpressed human ABCC5. Using membrane vesicles, we show that ABCC5 not only transports the metabolites detected in our screen, but also a wide range of peptides containing a C-terminal glutamate. Glutamate conjugates are of physiological relevance because they can affect the function of glutamate, the principal excitatory neurotransmitter in the brain. We found that ABCC5 also transports exogenous glutamate analogs, like the classic excitotoxic neurotoxins kainic acid, domoic acid and N-methyl-D-aspartate (NMDA) and the therapeutic glutamate analog ZJ43. Taken together, we have identified ABCC5 as a general glutamate conjugate and analog transporter that affects the disposition of endogenous metabolites, toxins and drugs. Overall design: A set of 5 wildtype brains was compared to a set of 5 Abcc5-knockout mouse brains
ATP-binding Cassette Subfamily C Member 5 (ABCC5) Functions as an Efflux Transporter of Glutamate Conjugates and Analogs.
No sample metadata fields
View SamplesIn Rspondin-based 3D cultures, Lgr5 stem cells from multiple organs form ever-expanding epithelial organoids that retain their tissue identity. We report the establishment of tumor organoid cultures from 20 consecutive colorectal (CRC) patients. For most, organoids were also generated from adjacent normal tissue. The organoids closely resemble the original tumor. The spectrum of genetic changes observed within the 'living biobank' agrees well with previous large-scale mutational analyses of CRC. Gene expression analysis indicates that the major CRC molecular subtypes are represented. Tumor organoids are amenable to robotized, high-throughput drug screens allowing detection of gene-drug associations. As an example, a single organoid culture was exquisitely sensitive to Wnt secretion (porcupine) inhibitors and carried a mutation in the negative Wnt feedback regulator RNF43 (rather than in APC). Organoid technology may fill the gap between cancer genetics and patient trials, complement cell line- and xenograft-based drug studies and allow personalized therapy design.
Prospective derivation of a living organoid biobank of colorectal cancer patients.
Specimen part, Disease, Disease stage, Subject
View SamplesWe previously established long-term 3D organoid culture systems for several murine tissues (intestine, stomach, pancreas and liver) as well as human intestine and pancreas. Here, we describe culture conditions to generate long-term 3D culture from human gastric stem cells. The technology can be applied to study the epithelial response to infection with Helicobacter pylori. Human gastric cultures can expand indefinitely in 3D Matrigel. Cultures can be generated from normal tissue, from single sorted stem cells, or from tumor tissue. Organoids maintain many characteristics of the respective tissue in terms of histology, marker expression and euploidy. Organoids from normal tissue express markers of four lineages of the stomach and self-organize in gland and pit-domains. They can be directed to specifically express either lineages of the gastric gland, or the gastric pit by addition of Nicotinamide and withdrawal of Wnt. While gastric pit lineages react marginally to bacterial infection, gastric gland lineages mount a strong inflammatory response. The gastric culture system provides a unique tool to study gastric pathologies.
In vitro expansion of human gastric epithelial stem cells and their responses to bacterial infection.
Sex, Age, Specimen part, Treatment
View SamplesIntervertebral disc degeneration is an important contributor to chronic low back pain. While a wide spectrum of clinically relevant degenerative disc phenotypes have been observed during aging, their molecular underpinning have not been established.
Comparison of inbred mouse strains shows diverse phenotypic outcomes of intervertebral disc aging.
Age, Specimen part
View SamplesThe reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature (Core OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this combinatorial stem cell niche is a novel mechanism that may also explain cancer cell osteotropism and local interference with hematopoiesis (myelophthisis). Accordingly, these stem cell niche components may represent innovative therapeutic targets and/or serum biomarkers in osteoblastic bone metastasis.
The molecular signature of the stroma response in prostate cancer-induced osteoblastic bone metastasis highlights expansion of hematopoietic and prostate epithelial stem cell niches.
Specimen part
View SamplesRationale: Monitoring and controlling cardiomyocyte activity with optogenetic tools offers exciting possibilities for fundamental and translational cardiovascular research. Genetically encoded voltage indicators may be particularly attractive for minimal invasive and repeated assessments of cardiac excitation from the cellular to the whole heart level. Objective: To test the hypothesis that cardiomyocyte-targeted voltage-sensitive fluorescence protein 2.3 (VSFP2.3) can be exploited as optogenetic tool for the monitoring of electrical activity in isolated cardiomyocytes and the whole heart as well as function and maturity in induced pluripotent stem cell (iPSC)-derived cardiomyocytes. Methods and Results: We first generated mice with cardiomyocyte-restricted expression of VSFP2.3 and demonstrated distinct sarcolemmal localization of VSFP2.3 without any signs for associated pathologies (assessed by echocardiography). Optically recorded VSFP2.3 signals correlated well with membrane voltage measured simultaneously by patch-clamping. The utility of VSFP2.3 for human action potential recordings was confirmed by simulation of immature and mature action potentials in murine VSFP2.3 cardiomyocytes. Optical cardiograms (OCGs) could be monitored in whole hearts ex vivo and minimally invasively in vivo via fiber optics at physiological heart rate (10 Hz) and under pacing-induced arrhythmia. Finally, we reprogrammed tail-tip fibroblasts from transgenic mice and used the VSFP2.3 sensor for benchmarking functional and structural maturation in iPSC-derived cardiomyocytes. Conclusions: We introduce a novel transgenic voltage-sensor model as a new method in cardiovascular research and provide proof-of-concept for its utility in optogenetic sensing of physiological and pathological excitation in mature and immature cardiomyocytes in vitro and in vivo. Overall design: Determination of transgene (VSFP2.3) cardiotoxicity
Sensing Cardiac Electrical Activity With a Cardiac Myocyte--Targeted Optogenetic Voltage Indicator.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Constitutive expression of progesterone receptor isoforms promotes the development of hormone-dependent ovarian neoplasms.
Specimen part, Disease, Disease stage, Treatment
View Samples