Quantifying mesenchymal stem cells in the mononuclear cell fraction of bone marrow samples obtained for cell therapy.

AIMS: The use of bone marrow mononuclear cells (BMMNCs) as a source of mesenchymal stem cells (MSCs) for therapy has recently attracted the attention of researchers because BMMNCs can be easily obtained and do not require in vitro expansion before their use. This study was designed to quantify the MSC population in bone marrow (BM) samples obtained for cell therapy using flow cytometry to detect the CD271 antigen. MATERIAL AND METHODS: Autologous BM was obtained by posterior superior iliac crest aspiration under topical anesthesia. Mononuclear cells isolated from the BM aspirate on a Ficoll density gradient were used to treat patients with pressure ulcer (n = 13) bone nonunions (n = 3) or diabetic foot ulcers (n = 5). RESULTS: Our flow cytometry data revealed a low percentage as well as a high variability among patients of CD271(+)CD45(-) cells (range, 0.0017 to 0.0201%). All cultured MSC adhered to plastic dishes showing a capacity to differentiate into adipogenic and osteogenic lineages. CONCLUSIONS: Our findings suggested that the success of cell therapy was independent of the number of MSCs present in the BM aspirate used for autologous cell therapy.

New serum-derived albumin scaffold seeded with adipose-derived stem cells and olfactory ensheathing cells used to treat spinal cord injured rats.

Recent advances in spinal cord injury (SCI) research and cell culture techniques and biomaterials predict promising new treatments for patients with SCI or other nerve injuries. Biomaterial scaffolds form a substrate within which cells are instructed to form a tissue in a controlled manner. This study was designed to assess axon regeneration and locomotor recovery in rats with spinal cord injury treated with a novel serum-derived albumin scaffold seeded with adipose derived stem cells (ADSCs) and olfactory ensheathing cells (OECs). OECs are considered promising candidates for the treatment of SCI, and ADSCs have the ability to differentiate into neural lineages. In vitro experiments revealed that ADSCs and OECs adhered to the scaffold, remained viable and expressed specific markers of their cell types when cultured in the scaffold. Rats treated with scaffold plus cells showed locomotor skills at several time points from 45 days post-injury that were improved over those recorded in control injured, untreated animals. Astrocytic scars and tissue regeneration, identified using histological and immunohistochemical techniques, revealed that although the scaffold itself appeared to play a significant role in reducing glial scar formation and filling of the lesion cavity with cells, the presence of ADSCs and OECs in the scaffold led to the appearance of cells expressing markers of neurons and axons at the injury site. Our findings point to the clinical feasibility of an albumin scaffold seeded with ADSCs and OECs as a treatment candidate for use in spinal cord injury repair studies.

Retinoid receptor-specific agonists regulate bovine in vitro early embryonic development, differentiation and expression of genes related to cell cycle arrest and apoptosis.

A major goal in reproductive biotechnology is the identification of pathways that regulate early embryonic development and the allocation of cells to the inner cell mass (ICM) and trophectoderm (TE). Retinoids regulate the development and differentiation of the bovine blastocyst in vitro, although the involvement of the retinoid X receptors (RXRs) remains to be clarified. This paper compares the effect of a synthetic RXR agonist (LG100268; LG) with that of the retinoic acid receptor (RAR) agonist all-trans retinoic acid (ATRA) on blastulation. In vitro-produced morulae were treated for 48 h with LG (0.1 microM, 1 microM and 10 microM), ATRA 0.7 microM, or no additives. Treatment with ATRA did not increase the rate of development; however, the LG 0.1 microM treatment increased both the blastocyst development and hatching rate. Cell numbers increased in the ICM with LG 10 microM, while a dose-dependent reduction was observed in the TE in the presence of LG. Gene expression levels of p53 and p66 did not vary with LG but increased with ATRA. Both LG and ATRA activated bax, a pro-apoptotic gene and H2A.Z, a cell cycle-related gene. The above effects suggest the existence of active p53-dependent and -independent apoptotic pathways for ATRA and LG, respectively, in the bovine embryo. The expression of p53 and H2A.Z showed a strong, positive correlation (r=0.93; p<0.0001) in all experimental groups; both proteins are linked through the cell cycle. Agonists of RXR could be used to control blastocyst development and differentiation.

Identification of extraretinal photoreceptors in the teleost Phoxinus phoxinus.

The existence of cells capable of detecting changes of the photoperiod within the deep brain, the so-called deep brain photoreceptors, was proposed in the early years of the twentieth century. By using immunocytochemistry with antisera against phototransductory proteins on paraffin and vibratome sections, we have localized several positive areas in the brain of the teleost Phoxinus phoxinus. These areas were restricted to two encephalic regions: the epithalamus and the hypothalamus. Immunopositive (rod-opsin- and a-transducin-like) pinealocytes and parapinealocytes, as well as some sparse neurons in the habenula, were seen in the epithalamus. The immunoreaction of the hypothalamus was represented by a-transducin-like positive (magnocellular and parvicellular) neurons of the Nucleus Preopticus, as well as by a-transducin- and arrestin-like positive fibers corresponding to the hypothalamic-hypophyseal tract and a few fibers running towards the basal telencephalon. These findings corroborate the data published on other teleost fish and fully support the hypothesis of the presence of photosensitive cells in the encephalon of lower vertebrates. The labelling with antisera against different components of the phototransductory cascade also strengthens the idea that such cells employ a biochemical mechanism similar to that in the retinal visual photoreceptor cells, rods and cones. Although the function is still unclear, the detection of the photoperiod seems to be the most likely role for these extraretinal photoreceptors.