Lineage restriction of the myogenic conversion factor myf-5 in the brain

Development ◽  
1995 ◽  
Vol 121 (12) ◽  
pp. 4077-4083 ◽  
Author(s):  
S. Tajbakhsh ◽  
M.E. Buckingham

myf-5 is one of four transcription factors belonging to the MyoD family that play key roles in skeletal muscle determination and differentiation. We have shown earlier by gene targeting nlacZ into the murine myf-5 locus that myf-5 expression in the developing mouse embryo is closely associated with the restriction of precursor muscle cells to the myogenic lineage. We now identify unexpected expression of this myogenic factor in subdomains of the brain. myf-5 expression begins to be detected at embryonic day 8 (E8) in the mesencephalon and coincides with the appearance of the first differentiated neurons; expression in the secondary prosencephalon initiates at E10 and is confined to the ventral domain of prosomere p4, later becoming restricted to the posterior hypothalamus. This expression is observed throughout embryogenesis. No other member of the MyoD family is detected in these regions, consistent with the lack of myogenic conversion. Furthermore, embryonic stem cells expressing the myf-5/nlacZ allele yield both skeletal muscle and neuronal cells when differentiated in vitro. These observations raise questions about the role of myf-5 in neurogenesis as well as myogenesis, and introduce a new lineage marker for the developing brain.

2011 ◽  
Vol 57 (4) ◽  
pp. 356-361
Author(s):  
Ikuo Nishigaki ◽  
Gowri Rangasamy Gunassekaran ◽  
Panjan Nagappan Venkatesan ◽  
Mandupal Chaco Sabu ◽  
Sabu Priya ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Doaa Aboalola ◽  
Victor K. M. Han

As mesenchymal stem cells (MSCs) are being investigated for regenerative therapies to be used in the clinic, delineating the roles of the IGF system in MSC growth and differentiation, in vitro, is vital in developing these cellular therapies to treat degenerative diseases. Muscle differentiation is a multistep process, starting with commitment to the muscle lineage and ending with the formation of multinucleated fibers. Insulin-like growth factor binding protein-6 (IGFBP-6), relative to other IGFBPs, has high affinity for IGF-2. However, the role of IGFBP-6 in muscle development has not been clearly defined. Our previous studies showed that in vitro extracellular IGFBP-6 increased myogenesis in early stages and could enhance the muscle differentiation process in the absence of IGF-2. In this study, we identified the signal transduction mechanisms of IGFBP-6 on muscle differentiation by placental mesenchymal stem cells (PMSCs). We showed that muscle differentiation required activation of both AKT and MAPK pathways. Interestingly, we demonstrated that IGFBP-6 could compensate for IGF-2 loss and help enhance the muscle differentiation process by triggering predominantly the MAPK pathway independent of activating either IGF-1R or the insulin receptor (IR). These findings indicate the complex interactions between IGFBP-6 and IGFs in PMSC differentiation into the skeletal muscle and that the IGF signaling axis, specifically involving IGFBP-6, is important in muscle differentiation. Moreover, although the major role of IGFBP-6 is IGF-2 inhibition, it is not necessarily the case that IGFBP-6 is the main modulator of IGF-2.


2019 ◽  
Vol 20 (16) ◽  
pp. 3932 ◽  
Author(s):  
Barbara Świerczek-Lasek ◽  
Jacek Neska ◽  
Agata Kominek ◽  
Łukasz Tolak ◽  
Tomasz Czajkowski ◽  
...  

Pluripotent stem cells convert into skeletal muscle tissue during teratoma formation or chimeric animal development. Thus, they are characterized by naive myogenic potential. Numerous attempts have been made to develop protocols enabling efficient and safe conversion of pluripotent stem cells into functional myogenic cells in vitro. Despite significant progress in the field, generation of myogenic cells from pluripotent stem cells is still challenging—i.e., currently available methods require genetic modifications, animal-derived reagents, or are long lasting—and, therefore, should be further improved. In the current study, we investigated the influence of interleukin 4, a factor regulating inter alia migration and fusion of myogenic cells and necessary for proper skeletal muscle development and maintenance, on pluripotent stem cells. We assessed the impact of interleukin 4 on proliferation, selected gene expression, and ability to fuse in case of both undifferentiated and differentiating mouse embryonic stem cells. Our results revealed that interleukin 4 slightly improves fusion of pluripotent stem cells with myoblasts leading to the formation of hybrid myotubes. Moreover, it increases the level of early myogenic genes such as Mesogenin1, Pax3, and Pax7 in differentiating embryonic stem cells. Thus, interleukin 4 moderately enhances competence of mouse pluripotent stem cells for myogenic conversion.


Zygote ◽  
2013 ◽  
Vol 22 (4) ◽  
pp. 513-520 ◽  
Author(s):  
I. Bahena ◽  
E. Xu ◽  
M. Betancourt ◽  
E. Casas ◽  
Y. Ducolomb ◽  
...  

SummaryIn a previous study, we have identified a set of conserved spermatogenic genes whose expression is restricted to testis and ovary and that are developmentally regulated. One of these genes, the transcription factor Mael, has been reported to play an essential role in mouse spermatogenesis. Nevertheless, the role of Mael in mouse oogenesis has not been defined. In order to analyse the role of Mael in mouse oogenesis, the expression of this gene was blocked during early oogenesis in mouse in vitro using RNAi technology. In addition, the role of Mael during differentiation of embryonic stem cells (ESC) into germ cells in vitro was analysed. Results show that downregulation of Mael by a specific short interfering RNA disrupted fetal oocyte growth and differentiation in fetal ovary explants in culture and the expression of several germ-cell markers in ESC during their differentiation. These results suggest that there is an important role for Mael in early oogenesis and during germ-cell differentiation from embryonic stem cells in mouse in vitro.


Cell Medicine ◽  
2018 ◽  
Vol 10 ◽  
pp. 215517901773317
Author(s):  
Takako Tsugata ◽  
Naruo Nikoh ◽  
Tatsuya Kin ◽  
Chika Miyagi-Shiohira ◽  
Yoshiki Nakashima ◽  
...  

The low efficiency of in vitro differentiation of human embryonic stem cells (hESCs) or human-induced pluripotent stem cells (iPSCs) into insulin-producing cells is a crucial hurdle for the clinical implementation of human pluripotent stem cells (PSCs). Our previous investigation into the key factors for the differentiation of PSCs into insulin-producing cells suggested that the expression of GATA binding protein 6 (GATA6) and Gremlin 1 (GREM1) and inhibition of early growth response protein 1 (Egr1) may be important factors. In this study, we investigated the role of Egr1 in pancreas development. The transfection of small interfering RNA (siRNA) of Egr1 in the early phase induced the differentiation of iPSCs derived from fibroblasts (FiPSCs) into pancreatic endoderm and insulin-producing cells. In contrast, the downregulation of Egr1 in the late phase suppressed the differentiation of FiPSCs into pancreatic endoderm and insulin-producing cells. In addition, the overexpression of Egr1 suppressed the differentiation of iPSCs derived from pancreatic cells into pancreatic endoderm and insulin-producing cells. These data suggest that the downregulation of Egr1 in the early phase can efficiently induce the differentiation of iPSCs into insulin-producing cells.


2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Anichavezhi Devendran ◽  
Rasheed Bailey ◽  
Sumanta Kar ◽  
Francesca Stillitano ◽  
Irene Turnbull ◽  
...  

Background: Heart failure (HF) is a complex clinical condition associated with substantial morbidity and mortality worldwide. The contractile dysfunction and arrhythmogenesis related to HF has been linked to the remodelling of calcium (Ca ++ ) handling. Phospholamban (PLN) has emerged as a key regulator of intracellular Ca ++ concentration. Of the PLN mutations, L39X is intriguing as it has not been fully characterized. This mutation is believed to be functionally equivalent to PLN null (KO) but contrary to PLN KO mice, L39X carriers develop a lethal cardiomyopathy (CMP). Our study aims at using induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) from homozygous L39X carriers to elucidate the role of L39X in human pathophysiology. Our plan also involves the characterization of humanized L39X knock-in mice (KM), which we hypothesize will develop a CMP from mis-localization of PLN and disruption of Ca ++ signalling. Methodology and Results: Mononuclear cells from Hom L39X carriers were obtained to generate 11 integration-free patient-specific iPSC clones. The iPSC-CMs were derived using established protocols. Compared to the WT iPSC-CMs, the Hom L39X derived-CMs PLN had an abnormal cytoplasmic distribution and formed intracellular aggregates, with the loss of perinuclear localization. There was also a 70% and 50% reduction of mRNA and protein expression of PLN respectively in L39X compared to WT iPSC-CMs. These findings indicated that L39X PLN is both under-expressed and mis-localized within the cell. To validate this observation in-vivo, we genetically modified FVB mice to harbour the human L39X. Following electroporation, positively transfected mouse embryonic stem cells were injected into host blastocysts to make humanized KM that were subsequently used to generate either a protamine-Cre (endogenous PLN driven expression) or a cardiac TNT mouse (i.e., CMP specific). Conclusion: Our data confirm an abnormal intracellular distribution of PLN, with the loss of perinuclear accumulation and mis-localization, suggestive of ineffective targeting to or retention of L39X. The mouse model will be critically important to validate the in-vitro observations and provides an ideal platform for future studies centred on the development of novel therapeutic strategies including virally delivered CRISPR/Cas9 for in-vivo gene editing and testing of biochemical signalling pathways.


Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1614
Author(s):  
Paulina Podkalicka ◽  
Jacek Stępniewski ◽  
Olga Mucha ◽  
Neli Kachamakova-Trojanowska ◽  
Józef Dulak ◽  
...  

Inadequate supply of oxygen (O2) is a hallmark of many diseases, in particular those related to the cardiovascular system. On the other hand, tissue hypoxia is an important factor regulating (normal) embryogenesis and differentiation of stem cells at the early stages of embryonic development. In culture, hypoxic conditions may facilitate the derivation of embryonic stem cells (ESCs) and the generation of induced pluripotent stem cells (iPSCs), which may serve as a valuable tool for disease modeling. Endothelial cells (ECs), multifunctional components of vascular structures, may be obtained from iPSCs and subsequently used in various (hypoxia-related) disease models to investigate vascular dysfunctions. Although iPSC-ECs demonstrated functionality in vitro and in vivo, ongoing studies are conducted to increase the efficiency of differentiation and to establish the most productive protocols for the application of patient-derived cells in clinics. In this review, we highlight recent discoveries on the role of hypoxia in the derivation of ESCs and the generation of iPSCs. We also summarize the existing protocols of hypoxia-driven differentiation of iPSCs toward ECs and discuss their possible applications in disease modeling and treatment of hypoxia-related disorders.


2008 ◽  
Vol 22 (3) ◽  
pp. 665-675 ◽  
Author(s):  
Pia Rantakari ◽  
Leena Strauss ◽  
Riku Kiviranta ◽  
Heidi Lagerbohm ◽  
Jenni Paviala ◽  
...  

Abstract Hydroxysteroid (17-β) dehydrogenase 2 (HSD17B2) is a member of aldo-keto reductase superfamily, known to catalyze the inactivation of 17β-hydroxysteroids to less active 17-keto forms and catalyze the conversion of 20α-hydroxyprogesterone to progesterone in vitro. To examine the role of HSD17B2 in vivo, we generated mice deficient in Hsd17b2 [HSD17B2 knockout (KO)] by a targeted gene disruption in embryonic stem cells. From the homozygous mice carrying the disrupted Hsd17b2, 70% showed embryonic lethality appearing at the age of embryonic d 11.5 onward. The embryonic lethality was associated with reduced placental size measured at embryonic d 17.5. The HSD17B2KO mice placentas presented with structural abnormalities in all three major layers: the decidua, spongiotrophoblast, and labyrinth. Most notable was the disruption of the spongiotrophoblast and labyrinthine layers, together with liquid-filled cysts in the junctional region and the basal layer. Treatments with an antiestrogen or progesterone did not rescue the embryonic lethality or the placenta defect in the homozygous mice. In hybrid background used, 24% of HSD17B2KO mice survived through the fetal period but were born growth retarded and displayed a phenotype in the brain with enlargement of ventricles, abnormal laminar organization, and increased cellular density in the cortex. Furthermore, the HSD17B2KO mice had unilateral renal degeneration, the affected kidney frequently appearing as a fluid-filled sac. Our results provide evidence for a role for HSD17B2 enzyme in the cellular organization of the mouse placenta.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Kateřina Štefková ◽  
Markéta Hanáčková ◽  
Jan Kučera ◽  
Katarzyna Anna Radaszkiewicz ◽  
Barbora Ambrůžová ◽  
...  

The activation of p38alpha kinase mediates cell response to various extracellular factors including many interleukins and growth factors important for haematopoiesis. The role of p38alpha kinase was previously analysed in particular haematopoietic cells. In this study and for the first time, the role of p38alpha kinase in haematopoiesis was studied using a model of continuous haematopoietic development in pluripotent embryonic stem cellsin vitro. The expression of transcripts associated with haematopoiesis and the potential for the formation of specific haematopoietic cell colonies were compared between wild-type and mutant p38alpha gene-depleted cells. The absence of p38alpha kinase led to the inhibition of hemangioblast formation during the first step of haematopoiesis. Later, during differentiation, due to the lack of p38alpha kinase, erythrocyte maturation was impaired. Mutant p38α−/−cells also exhibited decreased potential with respect to the expansion of granulocyte colony-forming units. This effect was reversed in the absence of erythropoietin as shown by colony-forming unit assay in media for colony-forming unit granulocytes/macrophages. p38alpha kinase thus plays an important role in the differentiation of common myeloid precursor cells into granulocyte lineages.


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