scholarly journals Interleukin-6 is an activator of pituitary stem cells upon local damage, a competence quenched in the aging gland

2021 ◽  
Vol 118 (25) ◽  
pp. e2100052118
Author(s):  
Annelies Vennekens ◽  
Emma Laporte ◽  
Florian Hermans ◽  
Benoit Cox ◽  
Elodie Modave ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Single Cell ◽  
Interleukin 6 ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Activation Process ◽  
Local Damage ◽  
Repair Capacity

Stem cells in the adult pituitary are quiescent yet show acute activation upon tissue injury. The molecular mechanisms underlying this reaction are completely unknown. We applied single-cell transcriptomics to start unraveling the acute pituitary stem cell activation process as occurring upon targeted endocrine cell–ablation damage. This stem cell reaction was contrasted with the aging (middle-aged) pituitary, known to have lost damage-repair capacity. Stem cells in the aging pituitary show regressed proliferative activation upon injury and diminished in vitro organoid formation. Single-cell RNA sequencing uncovered interleukin-6 (IL-6) as being up-regulated upon damage, however only in young but not aging pituitary. Administering IL-6 to young mice promptly triggered pituitary stem cell proliferation, while blocking IL-6 or associated signaling pathways inhibited such reaction to damage. By contrast, IL-6 did not generate a pituitary stem cell activation response in aging mice, coinciding with elevated basal IL-6 levels and raised inflammatory state in the aging gland (inflammaging). Intriguingly, in vitro stem cell activation by IL-6 was discerned in organoid culture not only from young but also from aging pituitary, indicating that the aging gland’s stem cells retain intrinsic activatability in vivo, likely impeded by the prevailing inflammatory tissue milieu. Importantly, IL-6 supplementation strongly enhanced the growth capability of pituitary stem cell organoids, thereby expanding their potential as an experimental model. Our study identifies IL-6 as a pituitary stem cell activator upon local damage, a competence quenched at aging, concomitant with raised IL-6/inflammatory levels in the older gland. These insights may open the way to interfering with pituitary aging.

scholarly journals Melatonin Reverses the Loss of Stemness Induced by TNF-α in Human Bone Marrow Mesenchymal Stem Cells through Upregulation of YAP Expression

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Xudong Wang ◽  
Tongzhou Liang ◽  
Jincheng Qiu ◽  
Xianjian Qiu ◽  
Bo Gao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Molecular Mechanisms ◽  
Inflammatory Factor ◽  
Cell Transplant ◽  
Alizarin Red ◽  
Marrow Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are promising candidates for tissue regeneration and disease treatment. However, long-term in vitro culture results in loss of MSC stemness. The inflammation that occurs at stem cell transplant sites (such as that resulting from TNF-α) is a contributing factor for stem cell treatment failure. Currently, there is little evidence regarding the protective role of melatonin with regard to the negative effects of TNF-α on the stemness of MSCs. In this study, we report a melatonin-based method to reduce the inflammatory effects on the stemness of bone marrow mesenchymal stem cells (BMMSCs). The results of colony formation assays, Alizarin red staining, western blotting, and reverse transcription-polymerase chain reactions suggest that melatonin can reverse the inflammatory damage caused by TNF-α treatment in the third, seventh, and tenth generations of primary BMMSCs (vs. control and the TNF-α-treated group). Meanwhile, a detailed analysis of the molecular mechanisms showed that the melatonin receptor and YAP signaling pathway are closely related to the role that melatonin plays in negative inflammatory effects against BMMSCs. In addition, in vivo experiments showed that melatonin could reverse the damage caused by TNF-α on bone regeneration by BMMSCs in nude mice. Overall, our results suggest that melatonin can reverse the loss of stemness caused by inflammatory factor TNF-α in BMMSCs. Our results also provide a practical strategy for the application of BMMSCs in tissue engineering and cell therapy.

scholarly journals CSIG-30. miR-146a INHIBITS TUMORIGENESIS AND INDUCES TEMOZOLOMIDE SENSITIVITY VIA AFFECTING CANCER STEM CELL PROPERTIES IN GBM

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi50-vi50
Author(s):  
Tiantian Cui ◽  
Erica Hlavin Bell ◽  
Joseph McElroy ◽  
Kevin Liu ◽  
Pooja Manchanda Gulati ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cell ◽  
Molecular Mechanisms ◽  
Functional Studies ◽  
Average Survival ◽  
Novel Biomarkers ◽  
The Ohio State University

Abstract BACKGROUND Glioblastomas (GBMs) are the most aggressive primary brain tumors, with an average survival time of less than 15 months. miRNAs are emerging as promising and novel biomarkers in GBM. The aims of this study are: 1) to investigate novel miRNAs biomarkers that affect tumorigenesis and therapeutic sensitivity, and 2) to study the underlying molecular mechanisms in GBM. METHODS Nanostring v3 was performed followed by univariable (UVA) and multivariable (MVA) analyses. Functional studies were conducted to define the role of miR-146a in GBM tumorigenesis and therapeutic response and the molecular mechanisms were investigated. RESULTS UVA analyses demonstrated that miR-146a is one of the top miRNAs that correlated with better prognosis in GBM patients (p=9.21E-05), which was independent of MGMT promoter methylation by MVA analyses (p< 0.001). miR-146a expression was significantly downregulated in recurrent GBM tumors compared with the paired primary GBM tumors (p=0.003). Overexpression of miR-146a significantly inhibited tumor cell growth and sensitized patient-derived primary GBM cells to temozolomide (TMZ) treatment in vitro, and showed statistically significant smaller tumor size (p< 0.01) and prolonged survival (p=0.001) in vivo. In addition, miR-146a is downregulated in glioma cancer stem cells, and overexpression of miR-146a significantly affected glioma cancer stem cell self-renewal. We also found that overexpression of miR-146a significantly inhibited the NF-κB, AKT, and ERK pathways. CONCLUSION Our data suggest, for the first time, that miR-146a predicts favorable prognosis for GBM patients and sensitizes primary GBM cells to TMZ treatment in vitro and in vivo through regulating glioma stem cells. Importantly, miR-146a may prove to be a master switch shutting off AKT, NF-κB, as well as other pathways and may overcome redundancies among these pathways leading to resistance. FUNDING: Bohnenn Fund (to PR), R01CA108633, R01CA169368, U10CA180850-01(NCI), Brain Tumor Funders Collaborative Grant, and The Ohio State University CCC (all to AC).

scholarly journals Transcriptional and Functional Description of Stem Cell Heterogeneity in Native and Transplantation Hematopoiesis

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3844-3844
Author(s):  
Alejo E Rodriguez-Fraticelli ◽  
Caleb Weinreb ◽  
Allon Moshe Klein ◽  
Fernando Camargo
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Steady State ◽  
Hematopoietic Stem Cells ◽  
Single Cell ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Significant Proportion ◽  
Cell Heterogeneity ◽  
Hematopoietic Stem

Abstract The hematopoietic system follows a hierarchical organization, with multipotent long-term repopulating hematopoietic stem cells (LT-HSCs) occupying the top tier. This paradigm, developed mostly through cell transplantation assays, has recently been contested by a series of studies performed under native conditions, without transplantation. Application of systems-level single cell methods in this setting has revealed a heterogeneity of cell states within progenitors and stem cells, prompting a reevaluation of the theories of hematopoietic lineage fate decisions. We have previously described that hematopoietic stem cell fates are clonally heterogeneous under steady state and uncovered that a fraction of LT-HSCs contributes to a significant proportion of the megakaryocytic cell lineage under steady state, while rarely generating other types of progeny in unperturbed conditions. To elucidate the molecular underpinnings of this functional lineage-output heterogeneity, we developed a technique to barcode hematopoietic cells at the RNA level in order to simultaneously capture the lineage relationships and transcriptional states of HSCs. Using a droplet-based massive single cell RNAseq platform, we analyzed thousands of engrafted hematopoietic stem cells together with a sufficiently significant representation of downstream progenitor cells to measure HSC output. Inspection of the resulting "stem cell state-fate maps" revealed a variety of stem cell behaviors, including single cell quiescence, asymmetric and symmetric divisions, and clonal expansion. We also connected these behaviors with some of the previously observed heterogeneity in stem cell outcomes, including lineage bias, lineage output and clonal competition. Importantly, clustering of expression profiles revealed significant differences in the transcriptional programs related with some of these behaviors, which illuminate the molecular machineries that operate at the stem cell level to define this heterogeneity. Thus, our work has identified potential novel mediators for stem cell heterogeneity, which we are functionally analyzing in further detail to understand their molecular mechanisms. Disclosures No relevant conflicts of interest to declare.

scholarly journals Reconstructing human early embryogenesis in vitro with pluripotent stem cells

2021 ◽  
Author(s):  
Berna Sozen ◽  
Victoria Jorgensen ◽  
Meng Zhu ◽  
Tongtong Cui ◽  
Magdalena Zernicka-Goetz
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Human Development ◽  
Pluripotent Stem Cells ◽  
Molecular Mechanisms ◽  
Early Embryo ◽  
Human Stem Cells ◽  
Amniotic Cavity ◽  
Early Human

ABSTRACTUnderstanding human development is of fundamental biological and clinical importance. Yet despite its significance, insights into early developmental events in humans still remain largely unknown. While recent advances show that stem cells can mimic embryogenesis1–9 to unravel hidden developmental mechanisms, a stem cell-based model of early human embryogenesis is lacking. Here, we use human extended pluripotent stem cells10to reconstitute early human development in 3-dimensions and recapitulate early embryo-like events. We first perform a systematic characterisation to reveal unique signalling requirements for building the human pre-implantation blastocyst. Further, we show that these in vitro stem cell-derived blastocyst-like structures are able to undertake spatiotemporal self-organisation to mimic peri-implantation remodelling in which a polarised rosette opens up the amniotic cavity within a developing disc. The hallmarks of human early development displayed by this stem cell-based in vitro model mimics features of embryonic day 3 to day 9/10 of natural development. Thus, this platform represents a tractable model system to contribute to the basic understanding of cellular and molecular mechanisms governing early embryonic events in humans and to provide valuable insights into the design of differentiation protocols for human stem cells in clinical applications.

scholarly journals Rapid Rapamycin-Only Induced Osteogenic Differentiation of Blood-Derived Stem Cells and Their Adhesion to Natural and Artificial Scaffolds

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Carpentieri Arianna ◽  
Cozzoli Eliana ◽  
Acri Flavio ◽  
Ranalli Marco ◽  
Diedenhofen Giacomo ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Stem Cell ◽  
Osteogenic Differentiation ◽  
Molecular Mechanisms ◽  
Maxillofacial Surgery ◽  
Ongoing Research ◽  
Medicine Research ◽  
Cell Based Therapy

Stem cells are a centerpiece of regenerative medicine research, and the recent development of adult stem cell-based therapy systems has vigorously expanded the scope and depth of this scientific field. The regeneration of damaged and/or degraded bone tissue in orthopedic, dental, or maxillofacial surgery is one of the main areas where stem cells and their regenerative potential could be used successfully, requiring tissue engineering solutions incorporating an ideal stem cell type paired with the correct mechanical support. Our contribution to this ongoing research provides a new model of in vitro osteogenic differentiation using blood-derived stem cells (BDSCs) and rapamycin, visibly expressing typical osteogenic markers within ten days of treatment. In depth imaging studies allowed us to observe the adhesion, proliferation, and differentiation of BDSCs to both titanium and bone scaffolds. We demonstrate that BDSCs can differentiate towards the osteogenic lineage rapidly, while readily adhering to the scaffolds we exposed them to. Our results show that our model can be a valid tool to study the molecular mechanisms of osteogenesis while tailoring tissue engineering solutions to these new insights.

scholarly journals Trajectory reconstruction identifies dysregulation of perinatal maturation programs in pluripotent stem cell-derived cardiomyocytes

2021 ◽  
Author(s):  
Suraj Kannan ◽  
Matthew Miyamoto ◽  
Brian L. Lin ◽  
Chulan Kwon
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Transcription Factors ◽  
Single Cell ◽  
Pluripotent Stem Cell ◽  
Directed Differentiation ◽  
Trajectory Reconstruction ◽  
Single Cell Rna Sequencing

ABSTRACTA primary limitation in the clinical application of pluripotent stem cell derived cardiomyocytes (PSC-CMs) is the failure of these cells to achieve full functional maturity. In vivo, cardiomyocytes undergo numerous adaptive changes during perinatal maturation. By contrast, PSC-CMs fail to fully undergo these developmental processes, instead remaining arrested at an embryonic stage of maturation. To date, however, the precise mechanisms by which directed differentiation differs from endogenous development, leading to consequent PSC-CM maturation arrest, are unknown. The advent of single cell RNA-sequencing (scRNA-seq) has offered great opportunities for studying CM maturation at single cell resolution. However, perinatal cardiac scRNA-seq has been limited owing to technical difficulties in the isolation of single CMs. Here, we used our previously developed large particle fluorescence-activated cell sorting approach to generate an scRNA-seq reference of mouse in vivo CM maturation with extensive sampling of perinatal time periods. We subsequently generated isogenic embryonic stem cells and created an in vitro scRNA-seq reference of PSC-CM directed differentiation. Through trajectory reconstruction methods, we identified a perinatal maturation program in endogenous CMs that is poorly recapitulated in vitro. By comparison of our trajectories with previously published human datasets, we identified a network of nine transcription factors (TFs) whose targets are consistently dysregulated in PSC-CMs across species. Notably, we demonstrated that these TFs are only partially activated in common ex vivo approaches to engineer PSC-CM maturation. Our study represents the first direct comparison of CM maturation in vivo and in vitro at the single cell level, and can be leveraged towards improving the clinical viability of PSC-CMs.Significance StatementThere is a significant clinical need to generate mature cardiomyocytes from pluripotent stem cells. However, to date, most differentiation protocols yield phenotypically immature cardiomyocytes. The mechanisms underlying this poor maturation state are unknown. Here, we used single cell RNA-sequencing to compare cardiomyocyte maturation pathways in endogenous and pluripotent stem cell-derived cardiomyocytes. We found that in vitro, cardiomyocytes fail to undergo critical perinatal gene expression changes necessary for complete maturation. We found that key transcription factors regulating these changes are poorly expressed in vitro. Our study provides a better understanding of cardiomyocyte maturation both in vivo and in vitro, and may lead to improved approaches for engineering mature cardiomyocytes from stem cells.

scholarly journals Pituitary Remodeling Throughout Life: Are Resident Stem Cells Involved?

2021 ◽  
Vol 11 ◽  
Author(s):  
Emma Laporte ◽  
Annelies Vennekens ◽  
Hugo Vankelecom
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pituitary Gland ◽  
Molecular Mechanisms ◽  
Pituitary Function ◽  
Cell Phenotype ◽  
Cell Populations ◽  
Cell Remodeling

The pituitary gland has the primordial ability to dynamically adapt its cell composition to changing hormonal needs of the organism throughout life. During the first weeks after birth, an impressive growth and maturation phase is occurring in the gland during which the distinct hormonal cell populations expand. During pubertal growth and development, growth hormone (GH) levels need to peak which requires an adaptive enterprise in the GH-producing somatotrope population. At aging, pituitary function wanes which is associated with organismal decay including the somatopause in which GH levels drop. In addition to these key time points of life, the pituitary’s endocrine cell landscape plastically adapts during specific (patho-)physiological conditions such as lactation (need for PRL) and stress (engagement of ACTH). Particular resilience is witnessed after physical injury in the (murine) gland, culminating in regeneration of destroyed cell populations. In many other tissues, adaptive and regenerative processes involve the local stem cells. Over the last 15 years, evidence has accumulated that the pituitary gland houses a resident stem cell compartment. Recent studies propose their involvement in at least some of the cell remodeling processes that occur in the postnatal pituitary but support is still fragmentary and not unequivocal. Many questions remain unsolved such as whether the stem cells are key players in the vivid neonatal growth phase and whether the decline in pituitary function at old age is associated with decreased stem cell fitness. Furthermore, the underlying molecular mechanisms of pituitary plasticity, in particular the stem cell-linked ones, are still largely unknown. Pituitary research heavily relies on transgenic in vivo mouse models. While having proven their value, answers to pituitary stem cell-focused questions may more diligently come from a novel powerful in vitro research model, termed organoids, which grow from pituitary stem cells and recapitulate stem cell phenotype and activation status. In this review, we describe pituitary plasticity conditions and summarize what is known on the involvement and phenotype of pituitary stem cells during these pituitary remodeling events.

O-189 Male fertility restoration by direct transplantation of human infant testicular cells into infertile recipient mouse testis

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
D Wang ◽  
S Hildorf ◽  
L Dong ◽  
S E Pors ◽  
L S Mamsen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Single Cell ◽  
In Vitro Propagation ◽  
Basal Membrane ◽  
Germline Stem Cell ◽  
Seminiferous Tubules ◽  
Recipient Mouse ◽  
Testicular Cells

Abstract Study question Is colonization of human gonocytes and spermatogonial stem cells (SSCs) directly transplanted to seminiferous tubules of busulfan sterilised mice testis during an 8-week period feasible?  Summary answer Gonocytes and SSCs from infant boys can settle on the basal membrane and form germline stem cell colonies in the seminiferous tubules of recipient mice. What is known already The neonatal or immature animal provides higher populations of gonocytes and/or SSCs than adults, and the number of transplanted donor SSCs directly affects the colonization rate of the recipient testes. Along with SSC transplantation restoring the recipient’s spermatogenesis, donor gonocyte was also reported to be capable of establishing spermatogenesis in rodents. Study design, size, duration Transplantation of human testicular cells including gonocytes and SSCs into seminiferous tubules of infertile recipient mice. We included 10 infant testis biopsies from which single-cell suspension was transplanted individually into the seminiferous tubules of 10 immunodeficient mice. The immunodeficient mouse testes were injected with busulfan to deplete germ cells. Four weeks later, we did the xenotransplantation. Then after eight weeks, we collected all mouse testes to do further analysis. Participants/materials, setting, methods Testis biopsies were obtained from cryptorchid boys undergoing orchidopexy. After enzymatic digestion of the testis biopsies, dissociated single-cell suspensions were pre-labeled with a green fluorescent dye. Then the single-cell suspensions were transplanted into seminiferous tubules of the infertile recipient mice. Eight weeks later, the presence of gonocytes and SSCs was determined by immunohistochemistry and whole-mount immunofluorescence. Main results and the role of chance Without in vitro propagation, naturally enriched human germline stem cells settled on the basal membrane of seminiferous tubules and survived in the mouse testes at least for two months demonstrating that human gonocytes and SSCs were capable of colonizing the recipient mouse seminiferous tubules. Limitations, reasons for caution The study samples were from infant boys with undescended testes that were more likely to contain gonocytes. It was not possible to determine which germ-cell type at transplantation resulted in the detected gonocytes and SSC colonies after xenotransplantation. Transplantation of gonocytes may include the potential risk of stem cell-related malignancy. Wider implications of the findings Without in vitro propagation, male germline stem cell-based transplantation could provide a relatively safe therapeutic treatment for prepubertal boys with cryptorchidism and boys diagnosed with cancer. This method could also facilitate clinical translation. Trial registration number not applicable

scholarly journals Stem Cells from a Female Rat Model of Type 2 Diabetes/Obesity and Stress Urinary Incontinence Are Damaged by In Vitro Exposure to its Dyslipidemic Serum, Predicting Inadequate Repair Capacity In Vivo

2019 ◽  
Vol 20 (16) ◽  
pp. 4044 ◽  
Author(s):  
Istvan Kovanecz ◽  
Robert Gelfand ◽  
Guiting Lin ◽  
Sheila Sharifzad ◽  
Alec Ohanian ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Stem Cells ◽  
Urinary Incontinence ◽  
Stem Cell ◽  
Stress Urinary Incontinence ◽  
Rat Model ◽  
Repair Capacity

Female stress urinary incontinence (FSUI) is prevalent in women with type 2 diabetes/obesity (T2D/O), and treatment is not optimal. Autograph stem cell therapy surprisingly has poor efficacy. In the male rat model of T2D/O, it was demonstrated that epigenetic changes, triggered by long-term exposure to the dyslipidemic milieu, led to abnormal global transcriptional signatures (GTS) of genes and microRNAs (miR), and impaired the repair capacity of muscle-derived stem cells (MDSC). This was mimicked in vitro by treatment of MDSC with dyslipidemic serum or lipid factors. The current study aimed to predict whether these changes also occur in stem cells from female 12 weeks old T2D/O rats, a model of FSUI. MDSCs from T2D/O (ZF4-SC) and normal female rats (ZL4-SC) were treated in vitro with either dyslipidemic serum (ZFS) from late T2D/O 24 weeks old female Zucker fatty (ZF) rats, or normal serum (ZLS) from 24 weeks old female Zucker lean (ZL) rats, for 4 days and subjected to assays for fat deposition, apoptosis, scratch closing, myostatin, interleukin-6, and miR-GTS. The dyslipidemic ZFS affected both female stem cells more severely than in the male MDSC, with some gender-specific differences in miR-GTS. The changes in miR-GTS and myostatin/interleukin-6 balance may predict in vivo noxious effects of the T2D/O milieu that might impair autograft stem cell (SC) therapy for FSUI, but this requires future studies.

scholarly journals Single-Cell Profiling of Coding and Noncoding Genes in Human Dopamine Neuron Differentiation

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 137
Author(s):  
Fredrik Nilsson ◽  
Petter Storm ◽  
Edoardo Sozzi ◽  
David Hidalgo Gil ◽  
Marcella Birtele ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Single Cell ◽  
Noncoding Rna ◽  
Early Stage ◽  
Cell Type ◽  
Cell Type Specificity ◽  
Neuron Differentiation ◽  
Cell Therapies

Dopaminergic (DA) neurons derived from human pluripotent stem cells (hPSCs) represent a renewable and available source of cells useful for understanding development, developing disease models, and stem-cell therapies for Parkinson’s disease (PD). To assess the utility of stem cell cultures as an in vitro model system of human DA neurogenesis, we performed high-throughput transcriptional profiling of ~20,000 ventral midbrain (VM)-patterned stem cells at different stages of maturation using droplet-based single-cell RNA sequencing (scRNAseq). Using this dataset, we defined the cellular composition of human VM cultures at different timepoints and found high purity DA progenitor formation at an early stage of differentiation. DA neurons sharing similar molecular identities to those found in authentic DA neurons derived from human fetal VM were the major cell type after two months in culture. We also developed a bioinformatic pipeline that provided a comprehensive long noncoding RNA landscape based on temporal and cell-type specificity, which may contribute to unraveling the intricate regulatory network of coding and noncoding genes in DA neuron differentiation. Our findings serve as a valuable resource to elucidate the molecular steps of development, maturation, and function of human DA neurons, and to identify novel candidate coding and noncoding genes driving specification of progenitors into functionally mature DA neurons.

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