The fine structure of coelomocytes of the sea urchin, Strongylocentrotus dröbachiensis (Müllier O.F.)

1972 ◽  
Vol 50 (1) ◽  
pp. 77-81 ◽  
Author(s):  
V. G. Vethamany ◽  
M. Fung
Keyword(s):  
Stem Cells ◽  
Fine Structure ◽  
Sea Urchin ◽  
Plasma Membranes ◽  
Cell Aggregation ◽  
Structural Components ◽  
Physiological Conditions ◽  
Different Types ◽  
Spherical Cells

The fine structure of six different types of coelomocytes from Strongylocentrotus dröbachiensis (Müller), a sea urchin, is described. (1) Phagocytic leukocytes have either phagosomes of different sizes or large bladder-like, as well as veils of, cytoplasmic extensions. Syncytia are not observed under normal physiological conditions, although cell aggregation occurs without fusing of the plasma membranes. (2) Vibra-tile cells have a conventional flagellum and numerous mucopolysaccharide granules fill their cytoplasm. (3) The amoeboid red spherule cells contain typical echinochrome granules showing three structural components. (4) Colorless spherule cells contain numerous vacuole-like structures. (5) Small spherical cells are probably stem cells. (6) The granulocytes are few in number.

scholarly journals Human Granulosa Cells—Stemness Properties, Molecular Cross-Talk and Follicular Angiogenesis

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1396
Author(s):  
Claudia Dompe ◽  
Magdalena Kulus ◽  
Katarzyna Stefańska ◽  
Wiesława Kranc ◽  
Błażej Chermuła ◽  
...  
Keyword(s):  
Stem Cells ◽  
Granulosa Cells ◽  
Polycystic Ovary ◽  
Ovarian Follicle ◽  
Cumulus Cells ◽  
Ovary Syndrome ◽  
Different Types ◽  
Metabolite Exchange ◽  
Reproductive Techniques ◽  
New Strategies

The ovarian follicle is the basic functional unit of the ovary, comprising theca cells and granulosa cells (GCs). Two different types of GCs, mural GCs and cumulus cells (CCs), serve different functions during folliculogenesis. Mural GCs produce oestrogen during the follicular phase and progesterone after ovulation, while CCs surround the oocyte tightly and form the cumulus oophurus and corona radiata inner cell layer. CCs are also engaged in bi-directional metabolite exchange with the oocyte, as they form gap-junctions, which are crucial for both the oocyte’s proper maturation and GC proliferation. However, the function of both GCs and CCs is dependent on proper follicular angiogenesis. Aside from participating in complex molecular interplay with the oocyte, the ovarian follicular cells exhibit stem-like properties, characteristic of mesenchymal stem cells (MSCs). Both GCs and CCs remain under the influence of various miRNAs, and some of them may contribute to polycystic ovary syndrome (PCOS) or premature ovarian insufficiency (POI) occurrence. Considering increasing female fertility problems worldwide, it is of interest to develop new strategies enhancing assisted reproductive techniques. Therefore, it is important to carefully consider GCs as ovarian stem cells in terms of the cellular features and molecular pathways involved in their development and interactions as well as outline their possible application in translational medicine.

scholarly journals The Potential of Nail Mini-Organ Stem Cells in Skin, Nail and Digit Tips Regeneration

2021 ◽  
Vol 22 (6) ◽  
pp. 2864
Author(s):  
Anna Pulawska-Czub ◽  
Tomasz D. Pieczonka ◽  
Paula Mazurek ◽  
Krzysztof Kobielak
Keyword(s):  
Stem Cells ◽  
Critical Role ◽  
Nail Plate ◽  
Molecular Characteristics ◽  
Continuous Growth ◽  
Physiological Conditions ◽  
Morphogenetic Protein ◽  
Slow Cycling ◽  
Bifunctional Properties

Nails are highly keratinized skin appendages that exhibit continuous growth under physiological conditions and full regeneration upon removal. These mini-organs are maintained by two autonomous populations of skin stem cells. The fast-cycling, highly proliferative stem cells of the nail matrix (nail stem cells (NSCs)) predominantly replenish the nail plate. Furthermore, the slow-cycling population of the nail proximal fold (nail proximal fold stem cells (NPFSCs)) displays bifunctional properties by contributing to the peri-nail epidermis under the normal homeostasis and the nail structure upon injury. Here, we discuss nail mini-organ stem cells’ location and their role in skin and nail homeostasis and regeneration, emphasizing their importance to orchestrate the whole digit tip regeneration. Such endogenous regeneration capabilities are observed in rodents and primates. However, they are limited to the region adjacent to the nail’s proximal area, indicating the crucial role of nail mini-organ stem cells in digit restoration. Further, we explore the molecular characteristics of nail mini-organ stem cells and the critical role of the bone morphogenetic protein (BMP) and Wnt signaling pathways in homeostatic nail growth and digit restoration. Finally, we investigate the latest accomplishments in stimulating regenerative responses in regeneration-incompetent injuries. These pioneer results might open up new opportunities to overcome amputated mammalian digits and limbs’ regenerative failures in the future.

scholarly journals Stem cells and exosomes: promising candidates for necrotizing enterocolitis therapy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ruijie Zeng ◽  
Jinghua Wang ◽  
Zewei Zhuo ◽  
Yujun Luo ◽  
Weihong Sha ◽  
...  
Keyword(s):  
Stem Cells ◽  
Necrotizing Enterocolitis ◽  
Therapeutic Effects ◽  
Beneficial Effects ◽  
Pediatric Diseases ◽  
Gastrointestinal Conditions ◽  
Different Types ◽  
Novel Therapeutic Strategies

AbstractNecrotizing enterocolitis (NEC) is a devastating disease predominately affecting neonates. Despite therapeutic advances, NEC remains the leading cause of mortality due to gastrointestinal conditions in neonates. Stem cells have been exploited in various diseases, and the application of different types of stem cells in the NEC therapy is explored in the past decade. However, stem cell transplantation possesses several deficiencies, and exosomes are considered potent alternatives. Exosomes, especially those derived from stem cells and breast milk, demonstrate beneficial effects for NEC both in vivo and in vitro and emerge as promising options for clinical practice. In this review, the function and therapeutic effects of stem cells and exosomes for NEC are investigated and summarized, which provide insights for the development and application of novel therapeutic strategies in pediatric diseases. Further elucidation of mechanisms, improvement in preparation, bioengineering, and administration, as well as rigorous clinical trials are warranted.

scholarly journals Heterogeneity of mesenchymal stem cells in cartilage regeneration: from characterization to application

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Kangkang Zha ◽  
Xu Li ◽  
Zhen Yang ◽  
Guangzhao Tian ◽  
Zhiqiang Sun ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Articular Cartilage ◽  
Cartilage Repair ◽  
Cartilage Damage ◽  
Cartilage Regeneration ◽  
Great Promise ◽  
Traditional Treatment ◽  
Different Types ◽  
Selection Of

AbstractArticular cartilage is susceptible to damage but hard to self-repair due to its avascular nature. Traditional treatment methods are not able to produce satisfactory effects. Mesenchymal stem cells (MSCs) have shown great promise in cartilage repair. However, the therapeutic effect of MSCs is often unstable partly due to their heterogeneity. Understanding the heterogeneity of MSCs and the potential of different types of MSCs for cartilage regeneration will facilitate the selection of superior MSCs for treating cartilage damage. This review provides an overview of the heterogeneity of MSCs at the donor, tissue source and cell immunophenotype levels, including their cytological properties, such as their ability for proliferation, chondrogenic differentiation and immunoregulation, as well as their current applications in cartilage regeneration. This information will improve the precision of MSC-based therapeutic strategies, thus maximizing the efficiency of articular cartilage repair.

scholarly journals Biological importance of OCT transcription factors in reprogramming and development

2021 ◽  
Author(s):  
Kee-Pyo Kim ◽  
Dong Wook Han ◽  
Johnny Kim ◽  
Hans R. Schöler
Keyword(s):  
Stem Cells ◽  
Transcription Factors ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Ectopic Expression ◽  
Donor Cell ◽  
Structural Components ◽  
Oct4 Expression ◽  
Reprogramming Factors ◽  
Induced Pluripotent

AbstractEctopic expression of Oct4, Sox2, Klf4 and c-Myc can reprogram somatic cells into induced pluripotent stem cells (iPSCs). Attempts to identify genes or chemicals that can functionally replace each of these four reprogramming factors have revealed that exogenous Oct4 is not necessary for reprogramming under certain conditions or in the presence of alternative factors that can regulate endogenous Oct4 expression. For example, polycistronic expression of Sox2, Klf4 and c-Myc can elicit reprogramming by activating endogenous Oct4 expression indirectly. Experiments in which the reprogramming competence of all other Oct family members tested and also in different species have led to the decisive conclusion that Oct proteins display different reprogramming competences and species-dependent reprogramming activity despite their profound sequence conservation. We discuss the roles of the structural components of Oct proteins in reprogramming and how donor cell epigenomes endow Oct proteins with different reprogramming competences.

scholarly journals Metabolic Profiling of Xylooligosaccharides by Lactobacilli

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2387
Author(s):  
Ilia Iliev ◽  
Tonka Vasileva ◽  
Veselin Bivolarski ◽  
Albena Momchilova ◽  
Iskra Ivanova
Keyword(s):  
Plasma Membranes ◽  
Meat Products ◽  
Lactobacillus Brevis ◽  
Degree Of Polymerization ◽  
Acid Fermentation ◽  
Carbohydrate Utilization ◽  
Beneficial Effects ◽  
Mixed Acid ◽  
Rat Liver Plasma Membranes ◽  
Different Types

Three lactic acid bacteria (LAB) strains identified as Lactobacillus plantarum, Lactobacillus brevis, and Lactobacillus sakei isolated from meat products were tested for their ability to utilize and grow on xylooligosaccharides (XOSs). The extent of carbohydrate utilization by the studied strains was analyzed by HPLC. All three strains showed preferences for the degree of polymerization (DP). The added oligosaccharides induced the LAB to form end-products of typical mixed-acid fermentation. The utilization of XOSs by the microorganisms requires the action of three important enzymes: β-xylosidase (EC 3.2.1.37) exo-oligoxylanase (EC 3.2.1.156) and α-L-arabinofuranosidase (EC 3.2.1.55). The presence of intracellular β-D-xylosidase in Lb. brevis, Lb. plantarum, and Lb. sakei suggest that XOSs might be the first imported into the cell by oligosaccharide transporters, followed by their degradation to xylose. The studies on the influence of XOS intake on the lipids of rat liver plasma membranes showed that oligosaccharides display various beneficial effects for the host organism, which are probably specific for each type of prebiotic used. The utilization of different types of oligosaccharides may help to explain the ability of Lactobacillus strains to compete with other bacteria in the ecosystem of the human gastrointestinal tract.

Dispersal of sperm surface antigens in the plasma membranes of polyspermically fertilized sea urchin eggs

1987 ◽  
Vol 173 (2) ◽  
pp. 628-632 ◽  
Author(s):  
David Nishioka ◽  
Donald C. Porter ◽  
James S. Trimmer ◽  
Victor D. Vacquier
Keyword(s):  
Sea Urchin ◽  
Plasma Membranes ◽  
Surface Antigens ◽  
Sea Urchin Eggs ◽  
Sperm Surface

Mesenchymal Stem Cells and Cancer Stem Cells: An Overview of Tumor-Mesenchymal Stem Cell Interaction for therapeutic interventions

2021 ◽  
Vol 22 ◽  
Author(s):  
Soheila Montazersaheb ◽  
Ezzatollah Fathi ◽  
Ayoub Mamandi ◽  
Raheleh Farahzadi ◽  
Hamid Reza Heidari
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Tumor Microenvironment ◽  
Cancer Stem Cells ◽  
Tumor Cells ◽  
Cell Types ◽  
Cell Interaction ◽  
Therapeutic Interventions ◽  
Tumorigenic Potential ◽  
Different Types

: Tumors are made up of different types of cancer cells that contribute to tumor heterogeneity. Among these cells, cancer stem cells (CSCs) have a significant role in the onset of cancer and development. Like other stem cells, CSCs are characterized by the capacity for differentiation and self-renewal. A specific population of CSCs is constituted by mesenchymal stem cells (MSCs) that differentiate into mesoderm-specific cells. The pro-or anti-tumorigenic potential of MSCs on the proliferation and development of tumor cells has been reported as contradictory results. Also, tumor progression is specified by the corresponding tumor cells like the tumor microenvironment. The tumor microenvironment consists of a network of reciprocal cell types such as endothelial cells, immune cells, MSCs, and fibroblasts as well as growth factors, chemokines, and cytokines. In this review, recent findings related to the tumor microenvironment and associated cell populations, homing of MSCs to tumor sites, and interaction of MSCs with tumor cells will be discussed.

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