Modification of Pluripotency and Neural Crest-Related Genes' expression in Murine Skin-Derived Precursor Cells by Leukemia Inhibitory Factor (LIF)

Skin-derived precursor cells (SKPs) are multipotent, sphere-forming and embryonic neural crest-related precursor cells that can be isolated from dermis. It is known that the properties of porcine SKPs can be enhanced by leukemia inhibitory factor (LIF) which is an essential factor for the generation of embryonic stem cells in mice. In our present study, to enhance or maintain the properties of murine SKPs, LIF was added to the culture medium. SKPs were treated with 1,000 IU LIF for 72 hours after passage 3. Quantitative real time RT-PCR was then performed to quantify the expression of the pluripotent stem cell specific genes Oct4, Nanog, Klf4 and c-Myc, and the neural crest specific genes Snai2 and Ngfr. The results show that the expression of Oct4 is increased in murine SKPs by LIF treatment whereas the level of Ngfr is decreased under these conditions. Interestingly, LIF treatment reduced Nanog expression which is also important for cell proliferation in adult stem cells and for osteogenic induction in mesenchymal stem cells. These findings implicate LIF in the maintenance of stemness in SKPs through the suppression of lineage differentiation and in part through the control of cell proliferation.

Transient lysosomal activation is essential for p75 nerve growth factor receptor expression in myelinated Schwann cells during Wallerian degeneration / 대한해부학회지

Myelinated Schwann cells in the peripheral nervous system express the p75 nerve growth factor receptor (p75NGFR) as a consequence of Schwann cell dedifferentiation during Wallerian degeneration. p75NGFR has been implicated in the remyelination of regenerating nerves. Although many studies have shown various mechanisms underlying Schwann cell dedifferentiation, the molecular mechanism contributing to the re-expression of p75NGFR in differentiated Schwann cells is largely unknown. In the present study, we found that lysosomes were transiently activated in Schwann cells after nerve injury and that the inhibition of lysosomal activation by chloroquine or lysosomal acidification inhibitors prevented p75NGFR expression at the mRNA transcriptional level in an ex vivo Wallerian degeneration model. Lysosomal acidification inhibitors suppressed demyelination, but not axonal degeneration, thereby suggesting that demyelination mediated by lysosomes may be an important signal for inducing p75NGFR expression. Tumor necrosis factor-alpha (TNF-alpha) has been suggested to be involved in regulating p75NGFR expression in Schwann cells. In this study, we found that removing TNF-alpha in vivo did not significantly suppress the induction of both lysosomes and p75NGFR. Thus, these findings suggest that lysosomal activation is tightly correlated with the induction of p75NGFR in demyelinating Schwann cells during Wallerian degeneration.

Expression of nerve growth factor and nerve growth factor receptor in human pancreatic cancer and its clinical significance / 第二军医大学学报

Objective: To explore the expression of nerve growth factor (NGF), its receptor P75NGFR and TrkA in the human pancreatic cancer tissues, and to study the relationship between the expression and clinical-pathological indices. Methods: The expression and morphological distribution of NGF, P75NGFR and TrkA were investgated in 65 pancreatic cancer tissues and 18 normal pancreas and chronic pancreatitis tissues by means of immunohistochemistry; the relationship between the expression and clinical-pathological indices was also investigated. Results: The expression of NGF and TrkA in human pancreatic cancer tissues was higher than that in the normal pancreas and chronic pancreatitis. Expression of P75NGFR had no significant change in the two groups. The expression of NGF was positively correlated with tumor size and was also associated with lymphatic invasion. The expression of P75NGFR and TrkA was closely correlated with lymphatic invasion. We also found that the expression of NGF was correlated with histological differentiation, tumor stage, tumor size and lymphatic invasion; the closest relationship was found between the expression of NGF and tumor size. The expression of P75NGFR was correlated with lymphatic invasion, the expression of TrkA was Correlated with both lymphatic invasion and tumor TNM stage. Patient's prognosis after surgery was mainly correlated with lymphatic invasion and the positive expression of TrkA. Conclusion: NGF, P75NGFR and TrkA participate in the progress of pancreatic cancer. TrkA is closely related to pancreatic cancer and can serve as an important target for gene therapy of pancreatic cancer in the future.

The Expressions of Nerve Growth Factor and Its Receptor p75NGFR in Hepatocellular Carcinoma: Their Relation with the Clinicopathologic Factors

BACKGROUND: Nerve growth factor (NGF) has been suggested to participate in tumor progression and it can interact with its receptor p75NGFR. In the present study, we investigated the expressions of NGF and p75NGFR in hepatocellular carcinoma (HCC). METHODS: We performed immunohistochemistry for NGF, p75NGFR and PCNA in 45 cases of HCCs, and examined the relationships between the clinicopathologic factors and the immunohistochemical results. RESULTS: NGF was detected in 84.4% (38/45) of the tumor cells and in 64.4% (29/45) of the non-tumorous hepatocytes. Furthermore, a NGF expression was present in 28.9% (13/45) of the endothelial cells in the HCCs, but in 80% (36/45) of the endothelial cells in the non-tumor liver tissue. The tumor cells were negative for p75NGFR in all the HCCs. Although a p75NGFR expression was present in all the nerve fibers in the non-tumor liver tissues, it was markedly reduced (42.2%; 19/45) in the HCCs and a p75NGFR expression was observed at the sinusoids or around the large vessels. The HCCs expressing NGF, either in the tumor cells or the endothelial cells, showed a larger size than those HCCs that didn't express NGF. The NGF positive tumors showed a tendency toward a higher PCNA-labeling index than did the negative tumors. CONCLUSIONS: The changed localization of the NGF expression and the decreased expression of p75NGFR are associated with hepatic carcinogenesis. We suggest that a NGF expression may contribute to the progression of HCC.

Morphometric Evaluation of PGP9.5 and NCAM Expressing Nerve Fibers in Colonic Muscle of Patients with Hirschsprung's Disease

A quantitative assessment of the density of the protein gene product 9.5 (PGP9.5), the neural cell adhesion molecule (NCAM), and the low-affinity nerve growth factor receptor (NGFR) expressing nerve fibers in the circular muscle layer in the colon was carried out by morphometric analyses from 13 patients with Hirschsprung's disease (HD). The difference in the nerve fiber density between the ganglionic and aganglionic segments was compared by calculating the ratio of the sum of the areas occupied by positively stained nerve fibers per unit area of the muscle after immunohistochemical staining on paraffin embedded tissue sections using computer software. There was an obvious difference in the density of the PGP9.5 stained nerve fibers between the ganglionic (0.0380 +/- 0.0171) and aganglionic segments (0.0143 +/- 0.01661). The NCAM-positive nerve fibers were fewer in number than those of both the PGP9.5-positive fibers and NCAM-positive fibers, which were also markedly lower in number in the aganglionic segment (0.0066 +/- 0.0076) than in the ganglionic segment (0.0230 +/- 0.0195). Immunostaining for low-affinity NGFR revealed much fainter staining in the ganglionic and aganglionic segment without a statistically significant difference in their density. Considering the fact that PGP9.5 is a very sensitive marker for nerve fibers, the results of this study reaffirm the innervation failure of the proper muscle in HD. The decreased NCAM expression level in the aganglionic segment appears to be caused not by the selective down-regulation of NCAM expression among the nerve fibers but by a markedly reduced number of nerve fibers.

Estudo imunohistoquímico e ultra-estrutural da inervação de de lesões cutâneas de hanseníase em fase inicial / Immunohistochemistry and ultrastructural analysis of the innervation of the skin lesions of leprosy in early stage

A neuropatia hanseniana (NH) é a principal condição responsável pela incapacidade e deformidade apresentadas pelo paciente portador da hanseníase...O conhecimento aprofundado sobre a biologia da NH além de ser justificado pelo seu fascinante interesse biológico, faz-se necessário para os programas de controle que almejam não só a diminuição da prevalência e da incidência da hanseníase, mas também a redução da morbidade das lesões neurais incapacitantes causadas pela doença.

THE CYTOCHEMICAI IDENTIFICATION OF THE NESTIN POSITIVE CELLS IN ADULT HUMAN BASAL FOREBRAIN / 解剖学报

Objective To investigate the distribution and chemical character of nestin immunoreactive cells in the human basal forebrain. Methods We explored systematically the distribution of nestin immunoreactive cells throughout the human basal forebrain by nestin 331B, 10C2, Rat401 antibody.Furthermore, we investigated the chemical identity of these nestin immunoreactive cells by using double\|labeling immunocytochemistry with NSE, ChAT, p75NGFR, GFAP antibody or using NADPH\|d histochemistry. Results The nestin immunoreactive cells were found in the septum, diagonal band of Broca, innominate substance,amygdala,basal nucleus of Meynert of adult human brain.These nestin immunoreactive cells haven big cell body,2\|3 processes.The nestin immunoreactive cells were labeled by NSE antibody.The large majority of those were single stained,and 28% were double labeled with ChAT positive neurons,15% with NGFR positive neurons,6% with NOS positive neurons.A few nestin immunoreactive cells shared similar morphology with that of astrocyte glia which existed in the spaces between the thin septa pellucida or the midline along the septum.It could not be labeled by GFAP antibody.Conclusion\ A new cluster of nestin immunoreactive neurons that were different from the ChAT,NGFR,NOS positive neurons existed in adult human basal forebrain.\;[