scholarly journals Characterization of JsWOX1 and JsWOX4 during Callus and Root Induction in the Shrub Species Jasminum sambac

Plants ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 79 ◽  
Author(s):  
Ying Lu ◽  
Zhuoyi Liu ◽  
Meiling Lyu ◽  
Yuan Yuan ◽  
Binghua Wu
Keyword(s):  
Stem Cells ◽  
De Novo ◽  
Callus Formation ◽  
Homeobox Gene ◽  
Woody Species ◽  
Root Induction ◽  
Wox Genes ◽  
Callus Proliferation ◽  
Jasminum Sambac

Plant regeneration in vitro and the underlying molecular regulatory network are of great interest to developmental biology, and have potential applications in agriculture and biotechnology. Cell growth and re-differentiation during de novo organogenesis require the activation and reprogramming of stem cells within the stem cell niche of the tissues. The WUSCHEL-related homeobox (WOX) factors play important roles in the maintenance and regulation of plant stem cells and are involved in many developmental processes. However, in woody species such as the Jasminum sambac, little is known about the involvement of WOX genes in de novo organogenesis. Here we show that two WOXs, JsWOX4 and JsWOX1, are implicated in callus proliferation and root regeneration, respectively. The expression of both, together with another member JsWOX13, are upregulated during later stage of callus formation. The JsWOX4 is associated with callus proliferation, or cell division during the redifferentiation. The overexpression of this gene results in up-regulation of JsWOX13 and another homeobox gene. The JsWOX1 plays a role in root primordium initiation, as its overexpression leads to more rooty calli and more roots per callus. JsWOX1 also possibly acts upstream of JsWOX4 and JsWOX13 transcriptionally. Our results provide further evidence regarding the functions of WOX genes in organogenesis in a woody plant.

scholarly journals Hematopoietic specification from human pluripotent stem cells: current advances and challenges toward de novo generation of hematopoietic stem cells

Blood ◽  
2013 ◽  
Vol 122 (25) ◽  
pp. 4035-4046 ◽  
Author(s):  
Igor I. Slukvin
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Pluripotent Stem Cells ◽  
De Novo ◽  
Human Pluripotent Stem Cells ◽  
Cellular Reprogramming ◽  
Hematopoietic Stem ◽  
Hematopoietic Development ◽  
Cellular Pathways

Abstract Significant advances in cellular reprogramming technologies and hematopoietic differentiation from human pluripotent stem cells (hPSCs) have already enabled the routine production of multiple lineages of blood cells in vitro and opened novel opportunities to study hematopoietic development, model genetic blood diseases, and manufacture immunologically matched cells for transfusion and cancer immunotherapy. However, the generation of hematopoietic cells with robust and sustained multilineage engraftment has not been achieved. Here, we highlight the recent advances in understanding the molecular and cellular pathways leading to blood development from hPSCs and discuss potential approaches that can be taken to facilitate the development of technologies for de novo production of hematopoietic stem cells.

Control of morphogenetic pathways in thin cell layers of tobacco by pH

1989 ◽  
Vol 67 (3) ◽  
pp. 650-654 ◽  
Author(s):  
A. Cousson ◽  
P. Toubart ◽  
K. Tran Thanh Van
Keyword(s):  
Butyric Acid ◽  
De Novo ◽  
Culture Media ◽  
Callus Formation ◽  
Medium Ph ◽  
Vegetative Buds ◽  
Cell Layers ◽  
Initial Medium ◽  
Vegetative Bud

Thin cell layer explants of tobacco were floated in vitro on the surface of liquid culture media. The initial exogenous concentrations of indolyl-3-butyric acid, and kinetin, the initial medium pH, and the explant density were varied. Various patterns of de novo and direct differentiation without any intermediate callus (flower, vegetative bud, root) as well as the absence of morphogenesis and callus formation without any subsequent organogenesis were separately controlled on 100% of the explants. On the same exogenous combination of glucose, indolyl-3-butyric acid, and kinetin, changes in initial medium pH changed the pattern of morphogenesis. For a given initial exogenous indolyl-3-butyric acid concentration, vegetative buds were obtained at either pH 6.1 or 7.8, whereas a mixture of flowers and vegetative buds was obtained at pH 6.8. Furthermore, changes in explant density changed the morphogenetic response. It is suggested that the effects of the initial medium pH and explant density on morphogenesis may be related partially to modifications of the physicochemical properties of the cell wall and (or) plasmalemma.

scholarly journals A Bioactive Cartilage Graft of IGF1-Transduced Adipose Mesenchymal Stem Cells Embedded in an Alginate/Bovine Cartilage Matrix Tridimensional Scaffold

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Nidia K. Moncada-Saucedo ◽  
Iván A. Marino-Martínez ◽  
Jorge Lara-Arias ◽  
Víktor J. Romero-Díaz ◽  
Alberto Camacho ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
De Novo ◽  
Cartilage Regeneration ◽  
Cartilage Injuries ◽  
Physicochemical Features ◽  
Microenvironmental Factors ◽  
Articular Cartilage Injuries

Articular cartilage injuries remain as a therapeutic challenge due to the limited regeneration potential of this tissue. Cartilage engineering grafts combining chondrogenic cells, scaffold materials, and microenvironmental factors are emerging as promissory alternatives. The design of an adequate scaffold resembling the physicochemical features of natural cartilage and able to support chondrogenesis in the implants is a crucial topic to solve. This study reports the development of an implant constructed with IGF1-transduced adipose-derived mesenchymal stem cells (immunophenotypes: CD105+, CD90+, CD73+, CD14-, and CD34-) embedded in a scaffold composed of a mix of alginate/milled bovine decellularized knee material which was cultivated in vitro for 28 days (3CI). Histological analyses demonstrated the distribution into isogenous groups of chondrocytes surrounded by a de novo dense extracellular matrix with balanced proportions of collagens II and I and high amounts of sulfated proteoglycans which also evidenced adequate cell proliferation and differentiation. This graft also shoved mechanical properties resembling the natural knee cartilage. A modified Bern/O’Driscoll scale showed that the 3CI implants had a significantly higher score than the 2CI implants lacking cells transduced with IGF1 (16/18 vs. 14/18), representing high-quality engineering cartilage suitable for in vivo tests. This study suggests that this graft resembles several features of typical hyaline cartilage and will be promissory for preclinical studies for cartilage regeneration.

scholarly journals Canonical Wnts function as potent regulators of osteogenesis by human mesenchymal stem cells

2009 ◽  
Vol 185 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Guizhong Liu ◽  
Sapna Vijayakumar ◽  
Luca Grumolato ◽  
Randy Arroyave ◽  
HuiFang Qiao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Bone Formation ◽  
Wnt Signaling ◽  
De Novo ◽  
Human Mesenchymal Stem Cells ◽  
Mitogen Activated Protein Kinase ◽  
Bone Homeostasis

Genetic evidence indicates that Wnt signaling is critically involved in bone homeostasis. In this study, we investigated the functions of canonical Wnts on differentiation of adult multipotent human mesenchymal stem cells (hMSCs) in vitro and in vivo. We observe differential sensitivities of hMSCs to Wnt inhibition of osteogenesis versus adipogenesis, which favors osteoblastic commitment under binary in vitro differentiation conditions. Wnt inhibition of osteogenesis is associated with decreased expression of osteoblastic transcription factors and inhibition of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase activation, which are involved in osteogenic differentiation. An hMSC subpopulation exhibits high endogenous Wnt signaling, the inhibition of which enhances osteogenic and adipogenic differentiation in vitro. In an in vivo bone formation model, high levels of Wnt signaling inhibit de novo bone formation by hMSCs. However, hMSCs with exogenous expression of Wnt1 but not stabilized β-catenin markedly stimulate bone formation by naive hMSCs, arguing for an important role of a canonical Wnt gradient in hMSC osteogenesis in vivo.

The Role of Nucleophosmin In Hematopoietic Stem Cells and the Pathogenesis of Myelodysplastic Syndrome

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 95-95 ◽  
Author(s):  
Keisuke Ito ◽  
Paolo Sportoletti ◽  
John G Clohessy ◽  
Grisendi Silvia ◽  
Pier Paolo Pandolfi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Myelodysplastic Syndrome ◽  
Cell Biology ◽  
De Novo ◽  
Stem Cell Biology ◽  
Hematopoietic Stem

Abstract Abstract 95 Myelodysplastic syndrome (MDS) is an incurable stem cell disorder characterized by ineffective hematopoiesis and an increased risk of leukemia transformation. Nucleophosmin (NPM) is directly implicated in primitive hematopoiesis, the pathogenesis of hematopoietic malignancies and more recently of MDS. However, little is known regarding the molecular role and function of NPM in MDS pathogenesis and in stem cell biology. Here we present data demonstrating that NPM plays a critical role in the maintenance of hematopoietic stem cells (HSCs) and the transformation of MDS into leukemia. NPM is located on chromosome 5q and is frequently lost in therapy-related and de novo MDS. We have previously shown that Npm1 acts as a haploinsufficient tumor suppressor in the hematopoietic compartment and Npm1+/− mice develop a hematologic syndrome with features of human MDS, including increased susceptibility to leukemogenesis. As HSCs have been demonstrated to be the target of the primary neoplastic event in MDS, a functional analysis of the HSC compartment is essential to understand the molecular mechanisms in MDS pathogenesis. However, the role of NPM in adult hematopoiesis remains largely unknown as Npm1-deficiency leads to embryonic lethality. To investigate NPM function in adult hematopoiesis, we have generated conditional knockout mice of Npm1, using the Cre-loxP system. Analysis of Npm1 conditional mutants crossed with Mx1-Cre transgenic mice reveals that Npm1 plays a crucial role in adult hematopoiesis and ablation of Npm1 in adult HSCs leads to aberrant cycling and followed by apoptosis. Analysis of cell cycle status revealed that HSCs are impaired in their ability to maintain quiescence after Npm1-deletion and are rapidly depleted in vivo as well as in vitro. Competitive reconstitution assay revealed that Npm1 acts cell-autonomously to maintain HSCs. Conditional inactivation of Npm1 leads to an MDS phenotype including a profoundly impaired ability to differentiate into cells of the erythroid lineage, megakaryocyte dyspoiesis and centrosome amplification. Furthermore, Npm1 loss evokes a p53-dependent response and Npm1-deleted HSCs undergo apoptosis in vivo and in vitro. Strikingly, transfer of the Npm1 mutation into a p53-null background rescued the apoptosis of Npm1-ablated HSCs and resulted in accelerated transformation to an aggressive and lethal form of acute myeloid leukemia. Our findings highlight the crucial role of NPM in stem cell biology and identify a new mechanism by which MDS can progress to leukemia. This has important therapeutic implications for de novo MDS as well as therapy-related MDS, which is known to rapidly evolve to leukemia with frequent loss or mutation of TRP53. Disclosures: No relevant conflicts of interest to declare.

scholarly journals A novel microRNA-based strategy to expand the differentiation potency of stem cells

2019 ◽  
Author(s):  
María Salazar-Roa ◽  
Marianna Trakala ◽  
Mónica Álvarez-Fernández ◽  
Fátima Valdés-Mora ◽  
Cuiqing Zhong ◽  
...  
Keyword(s):  
Stem Cells ◽  
De Novo ◽  
Cardiac Injury ◽  
Dna Methyltransferases ◽  
Short Exposure ◽  
Differentiation Potential ◽  
Differentiation Capacity ◽  
Tetraploid Complementation

SUMMARYFull differentiation potential along with self-renewal capacity is a major property of pluripotent stem cells (PSCs). However, the differentiation capacity frequently decreases during expansion of PSCs in vitro. We show here that transient exposure to a single microRNA, expressed at early stages during normal development, improves the differentiation capacity of already-established murine and human PSCs. Short exposure to miR-203 in PSCs (miPSCs) results in expanded differentiation potency as well as improved efficiency in stringent assays such as tetraploid complementation and human-mouse interspecies chimerism. Mechanistically, these effects are mediated by direct repression of de novo DNA methyltransferases Dnmt3a and Dnmt3b, leading to transient and reversible erasing of DNA methylation. As a proof of concept, miR-203 improves differentiation and maturation of PSCs into cardiomyocytes in vitro as well as cardiac regeneration in vivo, after cardiac injury. These data support the use of transient exposure to miR-203 as a general and single method to reset the epigenetic memory in PSCs, and improve their use in regenerative medicine.

Developing a Model of Human Pluripotent to Hematopoietic Stem Cell Development in Mistrg Mice

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4755-4755
Author(s):  
John Astle ◽  
Yangfei Xiang ◽  
Anthony Rongvaux ◽  
Carla Weibel ◽  
Henchey Elizabeth ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Hematopoietic Progenitors ◽  
Hematopoietic Stem ◽  
Immunodeficient Mice

Abstract De novo generation of HSCs has been described as a "holy grail" of stem cell biology, however the factors required for converting human pluripotent stem cells (PSCs) to true hematopoietic stem cells (HSCs) capable of robust long-term engraftment have yet to be fully characterized. Two groups have shown that injection of PSCs into immunodeficient mice leads to teratomas containing niches producing hematopoietic progenitors capable of long-term engraftment. Once these hematopoietic progenitors and their microenvironments are better characterized, this system could be used as a model to help direct in vitro differentiation of PSCs to HSCs. Toward this end, we have injected human PSCs into immunodeficient mice expressing human rather than mouse M-CSF, IL-3, GM-CSF, and thrombopoietin, as well as both human and mouse versions of the "don't eat me signal" Sirpa (collectively termed MISTRG mice). These cytokines are known to support different aspects of hematopoiesis, and thrombopoietin in particular has been shown to support HSC maintenance, suggesting these mice may provide a better environment for human PSC-derived HSCs than the more traditional mice used for human HSC engraftment. The majority of teratomas developed so far in MISTRG contain human hematopoietic cells, and the CD34+ population isolated from over half of the teratomas contained hematopoietic colony forming cells by colony forming assay. These findings further corroborate this approach as a viable method for studying human PSC to HSC differentiation. Disclosures No relevant conflicts of interest to declare.

scholarly journals Transcriptome comparison between pluripotent and non-pluripotent calli derived from mature rice seeds

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sangrea Shim ◽  
Hee Kyoung Kim ◽  
Soon Hyung Bae ◽  
Hoonyoung Lee ◽  
Hyo Ju Lee ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
De Novo ◽  
Callus Formation ◽  
Molecular Processes ◽  
Rice Callus ◽  
Root Stem Cell ◽  
Cell Niche ◽  
Transcriptome Comparison ◽  
Cellular Competence

AbstractIn vitro plant regeneration involves a two-step practice of callus formation and de novo organogenesis. During callus formation, cellular competence for tissue regeneration is acquired, but it is elusive what molecular processes and genetic factors are involved in establishing cellular pluripotency. To explore the mechanisms underlying pluripotency acquisition during callus formation in monocot plants, we performed a transcriptomic analysis on the pluripotent and non-pluripotent rice calli using RNA-seq. We obtained a dataset of differentially expressed genes (DEGs), which accounts for molecular processes underpinning pluripotency acquisition and maintenance. Core regulators establishing root stem cell niche were implicated in pluripotency acquisition in rice callus, as observed in Arabidopsis. In addition, KEGG analysis showed that photosynthetic process and sugar and amino acid metabolism were substantially suppressed in pluripotent calli, whereas lipid and antioxidant metabolism were overrepresented in up-regulated DEGs. We also constructed a putative coexpression network related to cellular pluripotency in rice and proposed potential candidates conferring pluripotency in rice callus. Overall, our transcriptome-based analysis can be a powerful resource for the elucidation of the molecular mechanisms establishing cellular pluripotency in rice callus.

scholarly journals Optimization of Protocols for In Vitro Regeneration of Sugarcane (Saccharum officinarum)

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Shakra Jamil ◽  
Rahil Shahzad ◽  
Ghulam Mohyuddin Talha ◽  
Ghazala Sakhawat ◽  
Sajid-ur-Rahman ◽  
...  
Keyword(s):  
Plant Regeneration ◽  
Callus Induction ◽  
Embryogenic Callus ◽  
In Vitro Propagation ◽  
Callus Formation ◽  
Shoot Elongation ◽  
Root Induction ◽  
Rooting Media ◽  
Embryogenic Callus Formation

Sugarcane contributes 60–70% of annual sugar production in the world. Somaclonal variation has potential to enhance genetic variation present within a species. Present study was done to optimize an in vitro propagation protocol for sugarcane. The experiments included four varieties, 9 callus induction media, 27 regeneration media, and 9 root induction media under two-factor factorial CRD. Data were recorded on callus induction, embryogenic callus formation, shoot elongation (cm), root induction, and plant regeneration. Statistically significant differences existed between genotypes and treatments for callus induction (%), embryogenic callus formation (%), shoot elongation (cm), root induction, and plant regeneration (%). All parameters showed dependency on genotypes, culture media, and their interaction. Highest callus induction (95%) embryogenic callus formation (95%) was observed in callus induction media 5. Highest plantlet regeneration (98.9%) capacity was observed in regeneration media 11 whereas maximum shoot elongation (12.13 cm) and root induction (8.32) were observed in rooting media 4. G1 showed best response for all traits and vice versa for G4. Hence it was concluded that G1, callus induction media 5, regeneration media 11, and rooting media 4 are the best conditions for in vitro propagation of sugarcane.

Targeted deletion of the tachykinin 4 gene (TAC4−/−) influences the early stages of B lymphocyte development

Blood ◽  
2010 ◽  
Vol 116 (19) ◽  
pp. 3792-3801 ◽  
Author(s):  
Alexandra Berger ◽  
Patricia Benveniste ◽  
Steven A. Corfe ◽  
Anne H. Tran ◽  
Mary Barbara ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
B Cells ◽  
B Lymphocyte ◽  
De Novo ◽  
Targeted Deletion ◽  
Inhibitory Role ◽  
Proliferation And Differentiation

AbstractHemokinin-1 (HK-1), encoded by the TAC4 gene, is a tachykinin peptide that is predominantly expressed in non-neuronal cells, such as immune cells. We have disrupted the mouse TAC4 gene to obtain a better understanding of the actions of HK-1 during hematopoiesis. We demonstrate here that TAC4−/− mice exhibit an increase of CD19+CD117+HSA+BP.1− “fraction B” pro-B cells in the bone marrow, whereas pre-B, immature, and mature B cells are within the normal range. We show that in vitro cultures derived from TAC4−/− bone marrow, sorted “fraction B” pro-B cells or purified long-term reconstituting stem cells, contain significantly higher numbers of pro-B cells compared with controls, suggesting an inhibitory role for HK-1 on developing B cells. Supporting this idea, we show that addition of HK-1 to cultures established from long-term reconstituting stem cells and the newly described intermediate-term reconstituting stem cells leads to a significant decrease of de novo generated pro-B cells. Based on our studies, we postulate that HK-1 plays an inhibitory role in hematopoiesis, and we hypothesize that it may be part of the bone marrow microenvironment that supports and regulates the proliferation and differentiation of hematopoietic cells.

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