Quantity, distribution and phenotype of newly generated cells in the intact spinal cord of adult macaque monkeys.

The existence of proliferating cells in the intact spinal cord, their distribution and phenotype, are well studied in rodents. A limited number of studies also address the proliferation after spinal cord injury, in non-human primates. However, a detailed description of the quantity, distribution and phenotype of proliferating cells at different anatomical levels of the intact adult non-human primate spinal cord is lacking at present. In the present study, we analyzed normal spinal cord tissues from adult macaque monkeys (Macaca fuscata), infused with Bromo-2'-deoxyuridine (BrdU), and euthanized at 2h, 2 weeks, 5 weeks and 10 weeks after BrdU. We found a significantly higher density of BrdU + cells in the gray matter of cervical segments as compared to thoracic or lumbar segments, and a significantly higher density of proliferating cells in the posterior as compared to the anterior horn of the gray matter. BrdU + cells exhibited phenotype of microglia or endothelial cells (∼50%) or astroglial and oligodendroglial cells (∼40%), including glial progenitor phenotypes marked by the transcription factors Sox9 and Sox10. BrdU + cells also co-expressed other transcription factors known for their involvement in embryonic development, including Emx2, Sox1, Sox2, Ngn1, Olig1, Olig2, Olig3. In the central canal, BrdU + cells were located along the dorso-ventral axis and co-labeled for the markers Vimentin and Nestin. These results reveal the extent of cellular plasticity in the spinal cord of non-human primates under normal conditions.

The vomeronasal organ - incidence in a Bulgarian population.

BACKGROUND: The vomeronasal organ is an accessory olfactory organ found in vertebrates that specialises in the chemoreception of pheromones. This study aimed to explore the existence and occurrence of the vomeronasal organ in adult humans. METHODS: A total of 966 consecutive video recordings of out-patient nasopharyngolaryngoscopies performed at the St Marina University Hospital, Varna, Bulgaria, were retrospectively reviewed. RESULTS: Data analysis showed that from the evaluable cases, the organ was evident on the left side of the nasal septum in 14.93 per cent, on the right side in 21.15 per cent and bilaterally in 2.35 per cent of cases. The vomeronasal organ was present in a total of 26.83 per cent of the investigated subjects. CONCLUSION: More research should be focused on revealing the incidence and functionality of the organ, and on its preservation in surgical manipulations that affect the nasal septum and other nearby structures.

The autophagy regulators Ambra1 and Beclin 1 are required for adult neurogenesis in the brain subventricular zone.

Autophagy is a conserved proteolytic mechanism required for maintaining cellular homeostasis. The role of this process in vertebrate neural development is related to metabolic needs and stress responses, even though the importance of its progression has been observed in a number of circumstances, both in embryonic and in postnatal differentiating tissues. Here we show that the proautophagic proteins Ambra1 and Beclin 1, involved in the initial steps of autophagosome formation, are highly expressed in the adult subventricular zone (SVZ), whereas their downregulation in adult neural stem cells in vitro leads to a decrease in cell proliferation, an increase in basal apoptosis and an augmented sensitivity to DNA-damage-induced death. Further, Beclin 1 heterozygosis in vivo results in a significant reduction of proliferating cells and immature neurons in the SVZ, accompanied by a marked increase in apoptotic cell death. In sum, we propose that Ambra1- and Beclin 1-mediated autophagy plays a crucial role in adult neurogenesis, by controlling the survival of neural precursor cells.

Bone marrow-derived stromal cells can express neuronal markers by DHA/GPR40 signaling.

The exact origin of neural stem cells in the adult neurogenesis niche remains unknown. Our previous studies, however, indicated an implication of both bone marrow cells as potential progenitors of hippocampal newborn neurons and polyunsaturated fatty acids as ligands of G protein-coupled receptor 40 (GPR40) signaling. Here, we aimed at studying whether bone marrow-derived stromal cells (BMSC) treated by docosahexaenoic acid (DHA) can express neuronal markers in vitro. We focused on implication of DHA/GPR40 signaling for the expression of neural markers in clonally-expanded BMSC from young macaque monkeys. Cell cycle analysis revealed that the DHA plus bFGF treatment induced a decrease of BMSC proliferation and increased the cells in the G0 resting phase. The transitions from nestin-positive progenitors via immature neuronal (beta III-tubulin-positive) to mature neuronal (NF-M and Map2-positive) phenotypes were examined using RT-PCR, Western blot and immunocytochemistry. We detected a significant increase of GPR40 mRNA and protein expression after bFGF induction, being compared with the untreated BMSC. Addition of DHA, a representative GPR40 ligand, led to a significant down-regulation of GPR40, i.e., G protein-coupled receptor-specific internalization, with a subsequent upregulation of neuronal markers such as beta III-tubulin, NF-M and Map2. These data altogether suggest that adult primate BMSC can express neuronal markers with the aid of DHA/GPR40 signaling.

Cell proliferation index predicts relapse of brain metastases in non-irradiated patients.

BACKGROUND: Brain metastasis is a common complication and a major cause of morbidity and mortality in human malignancies. We investigated whether the proliferating cell index of surgically treated single brain metastasis would predict the relapse at a location remote from the initial resection site within 2 months of the excision in patients with uncontrolled systemic disease and not subjected to adjuvant whole brain radio-therapy. MATERIALS AND METHODS: Tissue biopsies derived from 25 patients with brain metastases specifically selected to be a single totally resected lesion and not treated subsequently by radiotherapy to the whole brain were stained by immunohistochemistry for the marker CDC47 and the proliferation index was calculated. The index was then analysed with respect to clinical parameters, including the incidence of brain relapse within 2 months of the first resection, the timing of diagnosis of brain metastasis as compared to the primary cancer diagnosis, and the perifocal brain oedema. RESULTS: Statistical evaluation of the indexes in the patients with brain metastases relapsing within 2 months after the first craniotomy (n = 13) revealed significantly higher values as compared to the patients with lesions which had not relapsed or which had relapsed more than 2 months after first craniotomy (n = 12). The synchronous brain metastasis (that is, those occurring before or within 2 months of the primary cancer diagnosis) had a significantly higher proliferation index than the metachronous lesions (those occurring more than 2 months after primary cancer diagnosis). CONCLUSIONS: The synchronous brain metastasis relapses within 2 months of primary resection and have a significantly higher proliferation index than the metachronous lesions which did not recur within 2 months. These results indicate that the estimation of the proliferation index of metastatic brain tumours may be helpful in predicting the course of disease progression.

Prognostic significance of hepatocyte growth factor and microvessel bone marrow density in patients with chronic myeloid leukaemia.

OBJECTIVE: The aims of the study were: (1) to perform a complex angiogenic assessment in chronic myeloid leukaemia (CML) patients using multiple parameters: bone marrow microvessel density (MVD), bone marrow immunohistochemical cellular expressions of vascular endothelial growth factor (VEGF) and its receptor KDR, as well as hepatocyte growth factor (HGF) and its receptor MET, and the plasma VEGF and HGF; and (2) to determine the clinical significance of these factors for patients with CML. MATERIAL AND METHODS: The VEGF and HGF plasma levels were analysed by ELISA in 38 newly diagnosed CML patients. Immunohistochemical methods were used to visualize the MVD as well as the cellular VEGF/KDR and HGF/MET expression. RESULTS: We found an increased MVD, cellular VEGF/KDR and HGF/MET expression and elevated plasma VEGF and HGF in CML patients. The plasma HGF, cellular HGF and MET expression correlated with the CML phase. The plasma HGF correlated with all markers reflecting the tumour burden (leucocytes, blast percentage, splenomegaly and LDH) as well as with the phase of CML and overall survival of the patients. Cox regression analysis determined the prognostic relevance of HGF and MVD parameters, but not for the plasma VEGF and cellular VEGF and KDR. CONCLUSIONS: Using a complex angiogenic assessment we determined an increased angiogenesis in CML patients. No prognostic relevance was found for VEGF plasma levels or VEGF/KDR cellular bone marrow expression. The increased cellular HGF and MET expressions could be considered high-risk factors for these patients. Plasma HGF and MVD were shown to be independent prognostic parameters for patients' survival.

Homo obesus: a metabotrophin-deficient species. Pharmacology and nutrition insight.

In most countries the prevalence of obesity now exceeds 15%, the figure used by the World Health Organization to define the critical threshold for intervention in nutritional epidemics. Here we describe Homo obesus (man the obese) as a recent phenotypic expression of Homo sapiens. Specifically, we classified Homo obesus as a species deficient of metabotrophic factors (metabotrophins), including endogenous proteins, which play essential role in the maintenance of glucose, lipid, energy and vascular homeostasis, and also improve metabolism-related processes such as inflammation and wound healing. Here we propose that pharmaceuticals, nutraceuticals and xenohormetics targeting transcriptional, secretory and/or signaling pathways of metabotrophins, particularly adiponectin, nerve growth factor, brain-derived neurotrophic factor, interleukin-10, and sirtuins, might be new tools for therapy of Homo obesus. Brief comment is also given to (i) exogenous metabotrophic agents represented by various classes of drugs, and (ii) adiponutrigenomics of lifespan.

Distribution and phenotype of proliferating cells in the forebrain of adult macaque monkeys after transient global cerebral ischemia.

We performed transient global cerebral ischemia on adult macaque monkeys by reversibly stopping blood flow to the brain. We labeled de novo-generated cells in postischemic animals as well as in sham-operated controls by infusing the DNA synthesis indicator BrdU, and subsequently investigated the distribution and phenotype of BrdU-labeled cells in several telencephalic regions at various time-points after ischemia. The ischemic insult significantly increased the number of proliferating cells in the hippocampus, SVZ, neocortex, and striatum, but had no such effect in PHR. In the olfactory bulb, ischemia did not change the proliferating cell levels in the first two postischemic weeks, but did increase these levels at long-term survival time periods. The majority of newly generated cells outside the germinative centers were of a glial phenotype, while neurons constituted only 1% of these cells. Notably, no new neurons were observed in the hippocampal CA1 sector, the region exhibiting the highest vulnerability to ischemia. Within the germinative centers, most BrdU-labeled cells were of a progenitor phenotype and a large proportion of these precursors sustained their existence in the niche for months after ischemia. Furthermore, cells with a progenitor phenotype were identified in brain parenchyma, and these might be responsible for the limited parenchymal neurogenesis as well as for the oligodendrogliogenesis and astrogliogenesis in striatum and neocortex. Our results show that ischemia differentially activates endogenous neural precursors residing in diverse locations of the adult primate CNS. A limited endogenous potential for postischemic neuronal repair exists in neocortex and striatum, but not in the hippocampus proper of the adult macaque monkey brain. The presence of putative parenchymal progenitors and of sustained progenitors in germinative centers opens novel possibilities for precursor cell recruitment to sites of injury. The molecular manipulation of this process may advance our ability to effectively apply brain progenitor cells in the treatment of human neurological diseases.

What are subcutaneous adipocytes really good for?

Our acute awareness of the cosmetic, psychosocial and sexual importance of subcutaneous adipose tissue contrasts dramatically with how poorly we have understood the biology of this massive, enigmatic, often ignored and much-abused skin compartment. Therefore, it is timely to recall the exciting, steadily growing, yet underappreciated body of evidence that subcutaneous adipocytes are so much more than just 'fat guys', hanging around passively to conspire, at most, against your desperate attempts to maintain ideal weight. Although the subcutis, quantitatively, tends to represent the dominant architectural component of human skin, conventional wisdom confines its biological key functions to those of energy storage, physical buffer, thermoregulation and thermoinsulation. However, already the distribution of human superficial adipose tissue, by itself, questions how justified the popular belief is that 'skin fat' (which actually may be more diverse than often assumed) serves primarily thermoinsulatory purposes. And although the metabolic complications of obesity are well appreciated, our understanding of how exactly subcutaneous adipocytes contribute to extracutaneous disease - and even influence important immune and brain functions! - is far from complete. The increasing insights recently won into subcutaneous adipose tissue as a cytokine depot that regulates innate immunity and cell growth exemplarily serve to illustrate the vast open research expanses that remain to be fully explored in the subcutis. The following public debate carries you from the evolutionary origins and the key functional purposes of adipose tissue, via adipose-derived stem cells and adipokines straight to the neuroendocrine, immunomodulatory and central nervous effects of signals that originate in the subcutis - perhaps, the most underestimated tissue of the human body. The editors are confident that, at the end, you shall agree: No basic scientist and no doctor with a serious interest in skin, and hardly anyone else in the life sciences, can afford to ignore the subcutaneous adipocyte - beyond its ample impact on beauty, benessence and body mass.

Expression of angiogenic and neurotrophic factors in the progenitor cell niche of adult monkey subventricular zone.

The subventricular zone along the anterior horn (SVZa) of the cerebral lateral ventricle of adult mammals contains multipotent progenitor cells, which supposedly exist in an angiogenic niche. Numerous signals are known to modulate the precursor cell proliferation, migration or differentiation, in rodent models. In contrast, the data on signals regulating the primate SVZa precursors in vivo are scarce. We analyzed the expression at protein level of a panel of angiogenic and/or neurotrophic factors and their receptors in SVZa of adult macaque monkeys, under normal condition or after transient global ischemia which enhances endogenous progenitor cell proliferation. We found that fms-like tyrosine kinase 1 (Flt1), a receptor for vascular endothelial cell growth factor, was expressed by over 30% of the proliferating progenitors, and the number of Flt1-positive precursors was significantly increased by the ischemic insult. Smaller fractions of mitotic progenitors were positive for the neurotrophin receptor tropomyosin-related kinase (Trk) B or the hematopoietic receptor Kit, while immature neurons expressed Flt1 and the neurotrophin receptor TrkA. Further, SVZa astroglia, ependymal cells and blood vessels were positive for distinctive sets of ligands/receptors, which we characterized. The presented data provide a molecular phenotypic analysis of cell types comprising adult monkey SVZa, and suggest that a complex network of angiogenic/neurotrophic signals operating in an autocrine or paracrine manner may regulate SVZa neurogenesis in the adult primate brain.

Transcription factor protein expression patterns by neural or neuronal progenitor cells of adult monkey subventricular zone.

The anterior subventricular zone of the adult mammalian brain contains progenitor cells which are upregulated after cerebral ischemia. We have previously reported that while a part of the progenitors residing in adult monkey anterior subventricular zone travels to the olfactory bulb, many of these cells sustain location in the anterior subventricular zone for months after injury, exhibiting a phenotype of either neural or neuronal precursors. Here we show that ischemia increased the numbers of anterior subventricular zone progenitor cells expressing developmentally regulated transcription factors including Pax6 (paired-box 6), Emx2 (empty spiracles-homeobox 2), Sox 1-3 (sex determining region Y-box 1-3), Ngn1 (neurogenin 1), Dlx1,5 (distalless-homeobox 1,5), Olig1,3 (oligodendrocyte lineage gene 1,3) and Nkx2.2 (Nk-box 2.2), as compared with control brains. Analysis of transcription factor protein expression by sustained neural or neuronal precursors in anterior subventricular zone revealed that these two cell types were positive for characteristic sets of transcription factors. The proteins Pax6, Emx2, Sox2,3 and Olig1 were predominantly localized to dividing neural precursors while the factors Sox1, Ngn1, Dlx1,5, Olig2 and Nkx2.2 were mainly expressed by neuronal precursors. Further, differences between monkeys and non-primate mammals emerged, related to expression patterns of Pax6, Olig2 and Dlx2. Our results suggest that a complex network of developmental signals might be involved in the specification of primate progenitor cells.

Neuroprotective effects of pyridoxal phosphate and pyridoxal against ischemia in monkeys.

Previously, in monkeys undergoing 20 min whole brain ischemia we demonstrated that the activated calpain-induced lysosomal disruption with the resultant leakage of cathepsins B and L, causes neuronal death in the cornu Ammonis (CA) 1 sector on day 5. Selective cathepsin inhibitors significantly protected ischemic CA1 neurons from delayed necrosis. Recently, pyridoxal phosphate (PLP) and pyridoxal (hydrochloride) (PL) were demonstrated to inhibit cathepsins B and L in vitro, because the active aldehyde at position 4 of the pyridine ring has an affinity for the active site -SH of cysteine residues of cathepsins. Here, we studied whether PLP and PL can, in vivo, protect monkey CA1 neurons from ischemic insult. In monkeys undergoing 20 min whole brain ischemia, 15 mg/kg body weight/day of drugs were intravenously injected for 10 days before and after the ischemic insult. Histological analysis of the surviving CA1 neurons was done using the hippocampus resected on day 5 after ischemia. For PLP or PL, approximately 17% (P = 0.0639) or 54% (P < 0.0001) of the total population (100%) of control CA1 neurons were, respectively, saved from the ischemia-induced neuronal death, showing a remarkable contrast to the surviving neurons (approximately 3.9%) in non-treated monkeys. These data suggested that PL (perhaps PLP intracellularly) is useful as a novel neuroprotectant in primates.