Transplantation of multipotent cells extracted from adult skeletal muscles into the subventricular zone of adult rats

Development of an Anti-EphB4 Monoclonal Antibody for Multiple Applications Against Breast Cancers

The erythropoietin-producing hepatocellular carcinoma (Eph) receptors are the largest receptor tyrosine kinase family. EphB4 is essential for cell adhesion and motility during embryogenesis. Pathologically, EphB4 is overexpressed and contributes to poor prognosis in various tumors. Therefore, specific monoclonal antibodies (mAbs) should be developed to predict the prognosis for multiple tumors with high EphB4 expression, including breast and gastric cancers. This study aimed to develop specific anti-EphB4 mAbs for multiple applications using the Cell-Based Immunization and Screening method. EphB4-overexpressed Chinese hamster ovary (CHO)-K1 (CHO/EphB4) cells were immunized into mice, and we established an anti-EphB4 mAb (clone B4Mab-7), which is applicable for flow cytometry, Western blot, and immunohistochemistry (IHC). B4Mab-7 reacted with endogenous EphB4-positive breast cancer cell line, MCF-7, but did not react with EphB4-knockout MCF-7 (BINDS-52) in flow cytometry. Dissociation constant (KD) values were determined to be 2.9 × 10-9 M and 1.3 × 10-9 M by flow cytometric analysis for CHO/EphB4 and MCF-7 cells, respectively. B4Mab-7 detected the EphB4 protein bands from breast cancer cells in Western blot, and stained breast cancer tissues in IHC. Altogether, B4Mab-7 is very useful for detecting EphB4 in various applications.

Cloned myogenic cells can transdifferentiate in vivo into neuron-like cells

Background

The question of whether intact somatic cells committed to a specific differentiation fate, can be reprogrammed in vivo by exposing them to a different host microenvironment is a matter of controversy. Many reports on transdifferentiation could be explained by fusion with host cells or reflect intrinsic heterogeneity of the donor cell population.

Methodology/Principal Findings

We have tested the capacity of cloned populations of mouse and human muscle progenitor cells, committed to the myogenic pathway, to transdifferentiate to neurons, following their inoculation into the developing brain of newborn mice. Both cell types migrated into various brain regions, and a fraction of them gained a neuronal morphology and expressed neuronal or glial markers. Likewise, inoculated cloned human myogenic cells expressed a human specific neurofilament protein. Brain injected donor cells that expressed a YFP transgene controlled by a neuronal specific promoter, were isolated by FACS. The isolated cells had a wild-type diploid DNA content.

Conclusions

These and other results indicate a genuine transdifferentiation phenomenon induced by the host brain microenvironment and not by fusion with host cells. The results may potentially be relevant to the prospect of autologous cell therapy approach for CNS diseases.

Neurons express hemoglobin alpha- and beta-chains in rat and human brains

Hemoglobin is the oxygen carrier in vertebrate blood erythrocytes. Here we report that hemoglobin chains are expressed in mammalian brain neurons and are regulated by a mitochondrial toxin. Transcriptome analyses of laser-capture microdissected nigral dopaminergic neurons in rats and striatal neurons in mice revealed the presence of hemoglobin alpha, adult chain 2 (Hba-a2) and hemoglobin beta (Hbb) transcripts, whereas other erythroid markers were not detected. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis confirmed the expression of Hba-a2 and Hbb in nigral dopaminergic neurons, striatal gamma-aminobutyric acid (GABA)ergic neurons, and cortical pyramidal neurons in rats. Combined in situ hybridization histochemistry and immunohistochemistry with the neuronal marker neuronal nuclear antigen (NeuN) in rat brain further confirmed the presence of hemoglobin mRNAs in neurons. Immunohistochemistry identified hemoglobin alpha- and beta-chains in both rat and human brains, and hemoglobin proteins were detected by Western blotting in whole rat brain tissue as well as in cultures of mesencephalic neurons, further excluding the possibility of blood contamination. Systemic administration of the mitochondrial inhibitor rotenone (2 mg/kg/d, 7d, s.c.) induced a marked decrease in Hba-a2 and Hbb but not neuroglobin or cytoglobin mRNA in transcriptome analyses of nigral dopaminergic neurons. Quantitative RT-PCR confirmed the transcriptional downregulation of Hba-a2 and Hbb in nigral, striatal, and cortical neurons. Thus, hemoglobin chains are expressed in neurons and are regulated by treatments that affect mitochondria, opening up the possibility that they may play a novel role in neuronal function and response to injury.

Class III beta-tubulin is constitutively coexpressed with glial fibrillary acidic protein and nestin in midgestational human fetal astrocytes: implications for phenotypic identity

Class III beta-tubulin isotype (betaIII-tubulin) is widely regarded as a neuronal marker in developmental neurobiology and stem cell research. To test the specificity of this marker protein, we determined its expression and distribution in primary cultures of glial fibrillary acidic protein (GFAP)-expressing astrocytes isolated from the cerebral hemispheres of 2 human fetuses at 18 to 20 weeks of gestation. Cells were maintained as monolayer cultures for 1 to 21 days without differentiation induction. By immunofluorescence microscopy, coexpression of betaIII-tubulin and GFAP was detected in cells at all time points but in spatially distinct patterns. The numbers of GFAP+ cells gradually decreased from Days 1 to 21 in vitro, whereas betaIII-tubulin immunoreactivity was present in 100% of cells at all time points. beta-III-tubulin mRNA and protein expression were demonstrated in cultured cells by reverse-transcriptase-polymerase chain reaction and immunoblotting, respectively. Glial fibrillary acidic protein+/beta-III-tubulin-positive cells coexpressed nestin and vimentin but lacked neurofilament proteins, CD133, and glutamate-aspartate transporter. Weak cytoplasmic staining was detected with antibodies against microtubule-associated protein 2 isoforms. Confocal microscopy, performed on autopsy brain samples of human fetuses at 16 to 20 gestational weeks, revealed widespread colocalization of GFAP and betaIII-tubulin in cells of the ventricular/subventricular zones and the cortical plate. Our results indicate that in the midgestational human brain, betaIII-tubulin is not neuron specific because it is constitutively expressed in GFAP+/nestin+ presumptive fetal astrocytes.

Effects of interleukin-6, leukemia inhibitory factor, and ciliary neurotrophic factor on the proliferation and differentiation of adult human myoblasts

Our previous studies have demonstrated that ciliary neurotrophic factor, a member of the interleukin-6-type cytokine superfamily, could inhibit the differentiation of myoblasts into mature myotubes at a certain concentration. In this study, another two members, interleukin-6 and leukemia inhibitory factor, together with ciliary neurotrophic factor were tested their roles in the proliferation and differentiation of myoblasts derived from the adult human skeletal muscles, in order to confirm that these cytokines might be a new type of regulatory factors on the myoblasts. The results showed that the effects of interleukin-6, leukemia inhibitory factor, and ciliary neurotrophic factor on the proliferation and differentiation of adult human myoblasts were different. Leukemia inhibitory factor in the dose of 10 ng/ml could accelerate the cell proliferation. Leukemia inhibitory factor in the dose of 10 or 50 ng/ml and ciliary neurotrophic factor in the dose of 10 or 50 ng/ml could inhibit the myoblast differentiation. The inhibition mechanism might be that leukemia inhibitory factor and ciliary neurotrophic factor inhibited the expressions of transcription factor MyoD/myf5, which could regulate the myoblast differentiation. This study will provide the experimental and theoretic foundations for the basic and clinical researches about human myoblasts.

Adult-derived stem cells and their potential for use in tissue repair and molecular medicine

This report reviews three categories of precursor cells present within adults. The first category of precursor cell, the epiblast-like stem cell, has the potential of forming cells from all three embryonic germ layer lineages, e.g., ectoderm, mesoderm, and endoderm. The second category of precursor cell, the germ layer lineage stem cell, consists of three separate cells. Each of the three cells is committed to form cells limited to a specific embryonic germ layer lineage. Thus the second category consists of germ layer lineage ectodermal stem cells, germ layer lineage mesodermal stem cells, and germ layer lineage endodermal stem cells. The third category of precursor cells, progenitor cells, contains a multitude of cells. These cells are committed to form specific cell and tissue types and are the immediate precursors to the differentiated cells and tissues of the adult. The three categories of precursor cells can be readily isolated from adult tissues. They can be distinguished from each other based on their size, growth in cell culture, expressed genes, cell surface markers, and potential for differentiation. This report also discusses new findings. These findings include the karyotypic analysis of germ layer lineage stem cells; the appearance of dopaminergic neurons after implantation of naive adult pluripotent stem cells into a 6-hydroxydopamine-lesioned Parkinson's model; and the use of adult stem cells as transport mechanisms for exogenous genetic material. We conclude by discussing the potential roles of adult-derived precursor cells as building blocks for tissue repair and as delivery vehicles for molecular medicine.