Anaglyph of Retinal Stem Cells And Developing Axons: Selective Volume Enhancement In Microscopy Images

Retinal stem cell culture has become a powerful research tool, but it requires reliable methods to obtain high‐quality images of living and fixed cells. This study describes a procedure for using phase contrast microscopy to obtain three‐dimensional (3‐D) images for the study of living cells by photographing a living cell in a culture dish from bottom to top, as well as a procedure to increase the quality of scanning electron micrographs and laser confocal images. The procedure may also be used to photograph clusters of neural stem cells, and retinal explants with vigorous axonal growth. In the case of scanning electron microscopy and laser confocal images, a Gaussian procedure is applied to the original images. The methodology allows for the creation of anaglyphs and video reconstructions, and provides high‐quality images for characterizing living cells or tissues, fixed cells or tissues, or organs observed with scanning electron and laser confocal microscopy. Its greatest advantage is that it is easy to obtain good results without expensive equipment. The procedure is fast, precise, simple, and offers a strategic tool for obtaining 3‐D reconstructions of cells and axons suitable for easily determining the orientation and polarity of a specimen. It also enables video reconstructions to be created, even of specimens parallel to the plastic base of a tissue culture dish, It is also helpful for studying the distribution and organization of living cells in a culture, as it provides the same powerful information as optical tomography, which most confocal microscopes cannot do on sterile living cells. Anat Rec, 297:770–780, 2014. © 2014 Wiley Periodicals, Inc.     

Hear the beat: decellularized mouse heart regenerated with human induced pluripotent stem cells

Heart tissue engineering holds a great potential for human heart disease therapy. Regeneration of whole biofunctional human heart is the ultimate goal of tissue engineering. Recent advances take the first step towards whole heart regeneration. However, a substantial amount of challenges have to be overcome.     

microRNA expression in erythropoiesis and erythroid disorders

MicroRNAs are a recently discovered class of small (c. 22 nt) naturally occurring non‐coding RNA molecules that regulate gene expression through binding to the un‐translated region of target mRNA. MicroRNAs play key roles in many cellular pathways including haematopoiesis and aberrant expression is a common feature of haematological malignancies. Whilst other areas of haematopoiesis have been extensively reviewed the involvement of microRNAs in red cell production (erythropoiesis) and disorders of this pathway is lacking. In this review the rapidly accumulating evidence that points to the major role microRNAs play in both erythropoiesis and erythroid disorders is discussed.     

Erythroid‐extrinsic regulation of normal erythropoiesis by retinoic acid receptors

Vitamin A and its derivatives (retinoids) are important regulators of haematopoiesis, acting via retinoic acid receptors (RARs). Epidemiological studies indicated an association of vitamin A deficiency with anaemia in humans. To define the requirements of RARs in erythropoiesis, we evaluated erythroid parameters in RAR germ‐line deficient and conditional knock out mice with erythroid specific deletion of RARs. Adult RARγ^?/? mice were anaemic, however, Epor‐Cre Rara^fl/fl, Epor‐Cre Rarg^fl/fl and Epor‐Cre Rara^fl/flg^fl/fl mice were normal, indicating a lack of an erythroid intrinsic RAR function. Therefore, erythroid‐specific RAR function is dispensable for erythropoiesis and RARγ plays an erythroid extrinsic role in erythropoiesis.     

Visualization of proliferating cells in the adult mammalian brain with the aid of ribonucleotide reductase

Proliferating cells are hardly detectable in the adult mammalian brain by microscopy of stained sections, but after pre-labeling with radioactive thymidine or 5'-bromo-2-deoxyuridine (BrdU), either marks the nucleus, as do mitosis-related proteins such as Ki67 and PCNA. Engineered virus may also be used to mark proliferating cells. One alternative approach is to use the enzyme ribonucleotide reductase (RNR), expressed by proliferating cells, but not by quiescent ones. A monoclonal antibody against the M1 subunit of RNR was used to visualize proliferating cells in the brains of adult normal rats, rabbits, pigs and sheep. Stem cells were distinctly outlined. In the subgranular layer in the hippocampal dentate gyrus, most RNR immunoreactive cells were bipolar to multipolar, and had a large cell body and long processes. Two different populations of RNR expressing cells were visualized in the subventricular zone in the forebrain, one dominated by small, bipolar cells extending into the rostral migratory stream, while the other was formed by large multipolar cells, adjacent to the ependyma, with processes extending to the lateral ventricle. Furthermore, rare RNR-expressing cells were recognized throughout the brain. The RNR immunoreactive cells were immature, as they did not express any marker characterizing differentiated neurons and glial cells, except for a fraction that co-expressed the gliofibrillary acidic protein. BrdU and RNR were co-localized in proliferating cells in animals pretreated with BrdU. We conclude that RNR immunohistochemistry can accurately visualize proliferating cells, including stem cells, in adult mammalian brains. The occurrence of processes at cell proliferation is elucidated. Further, the advocated approach does not require any pre-labeling, and can be carried out on fixed tissues.     

Phenotypic analysis of affected peripheral erythroid for CD59 in paroxysmal nocturnal hemoglobinuria

Objective To determine whether affected reticulocytes could be a reliable marker for the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH), we analyzed CD59-antigen expression on the membranes of reticulocytes and erythrocytesMethods We studied 10 PNH patients and 5 healthy volunteers by two-color flow cytometry with a membrane permeable fluorescent dye, thiazole orange (TO), and anti-CD59 monoclonal antibodies (MoAb) TO was introduced to gate reticulocytes and anti-CD59 MoAb were used to identify glycosylphosphatidylinositol (GPI)-deficient cellsResults Cells from healthy individuals were only CD59 positive However, in all PNH patients, CD59-antigen expression could be divided into 3 types: type Ⅰ cells (CD59 normally positive), type Ⅱ cells (CD59 partly positive) and type Ⅲ cells (CD59 negative) The majority of reticulocytes belonged to type Ⅲ cells, GPI-deficient cells (610%) In addition, the percentage of affected reticulocytes was higher than that of erythrocytesConclusions Analyzing PNH reticulocytes was important, because most patients had elevated numbers of reticulocytes, which represent more closely the recent erythroid output of BM However, circulating mature erythrocytes were subject to complement- mediated intravascular lysis Therefore, the percentage of abnormal erythrocytes may not accurately reflect the proliferation rate of normal and abnormal erythroid progenitor cells Thus, affected reticulocytes could be a more reliable indicator for the diagnosis of PNH than mature erythrocytes.