Polarized and Stage-Dependent Distribution of Immunoreactivity for Novel PDZ-Binding Protein Preso1 in Adult Neurogenic Regions

BACKGROUND: Adult neural stem cells have the potential for self-renewal and differentiation into multiple cell lineages via symmetric or asymmetric cell division. Preso1 is a recently identified protein involved in the formation of dendritic spines and the promotion of axonal growth in developing neurons. Preso1 can also bind to cell polarity proteins, suggesting a potential role for Preso1 in asymmetric cell division. METHODS: To investigate the distribution of Preso1, we performed immunohistochemistry with adult mouse brain slice. Also, polarized distribution of Preso1 was assessed by immunocytochemistry in cultured neural stem cells. RESULTS: Immunoreactivity for Preso1 (Preso1-IR) was strong in the rostral migratory stream and subventricular zone, where proliferating transit-amplifying cells and neuroblasts are prevalent. In cultured neural stem cells, Preso1-IR was unequally distributed in the cell cytosol. We also observed the distribution of Preso1 in the subgranular zone of the hippocampal dentate gyrus, another neurogenic region in the adult brain. Interestingly, Preso1-IR was transiently observed in the nuclei of doublecortin-expressing neuroblasts immediately after asymmetric cell division. CONCLUSION: Our study demonstrated that Preso1 is asymmetrically distributed in the cytosol and nuclei of neural stem/progenitor cells in the adult brain, and may play a significant role in cell differentiation via association with cell polarity machinery.

Oral epithelial stem cells in tissue maintenance and disease: the first steps in a long journey / 国际口腔科学杂志·英文版

The identification and characterization of stem cells is a major focus of developmental biology and regenerative medicine. The advent of genetic inducible fate mapping techniques has made it possible to precisely label specific cell populations and to follow their progeny over time. When combined with advanced mathematical and statistical methods, stem cell division dynamics can be studied in new and exciting ways. Despite advances in a number of tissues, relatively little attention has been paid to stem cells in the oral epithelium. This review will focus on current knowledge about adult oral epithelial stem cells, paradigms in other epithelial stem cell systems that could facilitate new discoveries in this area and the potential roles of epithelial stem cells in oral disease.

Small GTPases and formins in mammalian oocyte maturation: cytoskeletal organizers / 대한생식의학회지

The maturation process of mammalian oocytes accompanies an extensive rearrangement of the cytoskeleton and associated proteins. As this process requires a delicate interplay between the cytoskeleton and its regulators, it is often targeted by various external and internal adversaries that affect the congression and/or segregation of chromosomes. Asymmetric cell division in oocytes also requires specific regulators of the cytoskeleton, including formin-2 and small GTPases. Recent literature providing clues regarding how actin filaments and microtubules interact during spindle migration in mouse oocytes are highlighted in this review.

The hyperexpressions of putative stem cells in the eutopic endometrium of patients with advanced endometriosis / 대한산부인과학회지

OBJECTIVE: Recently it has been proposed that stem cells may be associated with the pathogenesis of endometriosis. The purposes of this study are to investigate whether the eutopic endometrial cells of women with or without endometriosis show the characteristics of stem cells in vitro and have a difference of the expressions of the undifferentiated stem cell markers as OCT-4 and CXCR4. METHODS: A total of 6 women with advanced endometriosis and a total of 10 women without endometriosis, adenomyosis or leiomyoma were included in this study. The eutopic endometrial cells, which were obtained from the menstrual blood at menstrual cycle day 2 to 4, were cultured in vitro for approximately 2 weeks, subsequently the putative very small stem cells were separated by Percoll density gradient method and were cultured. The expressions of OCT-4 and CXCR4 were analyzed by real time RT-PCR. RESULTS: The eutopic endometrial cells of the group of endometriosis compared with the control group showed the different morphological characteristics in vitro; more commonly heterogeneous supportive cells, very small round cells less than 3 micrometer and 5~15 micrometer sized hyperchromatic round cells. After the separation of very small round cells by Percoll density gradient method, these cells showed the several characteristics of stem cells; self-renewal, asymmetric cell division, colony formation and embryoid body-like formation. Also These cells showed the similar characteristics of very small embryonic-like stem cells; the mobile cells smaller than erythrocyte, the cell migration or adhesion to supportive cells, the sphere formation by cell aggregation and the formation of new differentiated cell by cell fusion. The expressions of OCT-4 and CXCR4 in the group of endometriosis are respectively 5.66 times and 17.69 times as high as the control group (P<0.05). CONCLUSION: The very small round cells less than 3 micrometer and 5~15 micrometer sized hyperchromatic round cells, which showed the several characteristics of stem cells in vitro, were more common in eutopic endometrial cells of patients with endometriosis and the expressions of OCT-4 and CXCR4 were significantly higher. This study suggests that stem cells might play a key role in the pathogenesis of endometriosis and OCT-4 and CXCR4 might be used as a tool for diagnosis or follow-up.