Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Increasing evidence indicates that nerve growth factor (NGF), in addition to its neurotrophic actions, exerts specific effects on cells of the immune system. This report show that the CD4-positive T cell line 9/6 expresses trk protooncogene, the signal transducing receptor unit for NGF, after TCR-mediated activation by Ag and APC. This receptor is of functional importance because interaction of NGF with Ag-stimulated 9/6 T cells induced the transcriptional activation of the c-fos gene, a hallmark of the biochemical response to NGF. Our findings that neither mitogen nor Ag stimulation induced the expression of the low affinity NGF receptor in 9/6 T cells indicate that trk alone is sufficient to mediate biologic activity of NGF in T lymphocytes.
 ...
PMID:Expression of functional trk tyrosine kinase receptors after T cell activation. 814 77

The adenomatous polyposis (APC) gene product is highly expressed in the central nervous system. To elucidate the contribution of the APC protein to neuronal differentiation, we used an inducible antisense mRNA vector to suppress APC protein expression and examined neuronal differentiation of PC12 cells induced by nerve growth factor (NGF). When antisense mRNA was induced, APC protein expression was suppressed to 20% of the noninduced level. In those cells, neurite extension induced by NGF and expression of microtubule-associated protein 2 (MAP2) was completely inhibited. However, once cells had differentiated, antisense APC mRNA expression and subsequent suppression of APC protein expression had no effect on either cell morphology or MAP2 protein expression. These results suggest that the wild type APC is critically involved only in the initiation of neuronal differentiation, but not in the maintenance of the differentiated phenotype, or that the neuronal phenotype could be maintained at lower level of APC protein.
 ...
PMID:APC protein is required for initiation of neuronal differentiation in rat pheochromocytoma PC12 cells. 1111 46

Chondroitin sulfate proteoglycans (CSPGs) and myelin-based inhibitors are the most studied inhibitory molecules in the adult central nervous system. Unlike myelin-based inhibitors, few studies have reported ways to overcome the inhibitory effect of CSPGs. Here, by using regenerating adult dorsal root ganglion (DRG) neurons, we show that chondroitin sulfate proteoglycans inhibit axon assembly by a different mechanism from myelin-based inhibitors. Furthermore, we show that neither Rho inhibition nor cAMP elevation rescues extracellular factor-induced axon assembly inhibited by CSPGs. Instead, our data suggest that CSPGs block axon assembly by interfering with integrin signaling. Surprisingly, we find that nerve growth factor (NGF) promotes robust axon growth of regenerating DRG neurons over CSPGs. We have found that, unlike naive neurons that require simultaneous activation of neurotrophin and integrin pathways for axon assembly, either neurotrophin or integrin signaling alone is sufficient to induce axon assembly of regenerating neurons. Thus, our results suggest that the ability of NGF to overcome CSPG inhibition in regenerating neurons is probably due to the ability of regenerating neurons to assemble axons using an integrin-independent pathway. Finally, our data show that the GSK-3beta-APC pathway, previously shown to mediate developing axon growth, is also necessary for axon regeneration.
 ...
PMID:Neurotrophins support regenerative axon assembly over CSPGs by an ECM-integrin-independent mechanism. 1677 33

The trophic neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) increases in many different neuron types following injury; a response postulated to support cell survival and regeneration. In acutely isolated cardiac ganglia, approximately 1% of the cardiac neurons exhibited PACAP immunoreactivity whereas after 72 h in culture, approximately 25% of the neurons were PACAP immunoreactive. In contrast, there was no increase in vasoactive intestinal polypeptide (VIP)-immunoreactive (IR) cells. Using a combination of immunocytochemical and molecular techniques, we have quantified PACAP expression, during explant culture of guinea-pig cardiac ganglia. Using real time polymerase chain reaction, PACAP transcript levels increased progressively up to 48 h in culture with no further increase after 72 h. PACAP transcript levels were reduced by neurturin at 48 h in culture but not after 24 or 72 h in culture. In addition, neurturin partially suppressed the percentage of PACAP-IR neurons after 72 h in culture, an effect mediated by activation of the phosphatidylinositol 3-kinase and mitogen-activated protein kinase signaling pathways. The addition of different known regulatory molecules, including ciliary neurotrophic factor (CNTF), interleukin-1 beta (Il-1beta), tumor necrosis factor-alpha (TNFalpha), fibroblast growth factor basic (bFGF), transforming growth factor-beta (TGF-beta) and nerve growth factor (NGF) did not increase the percentage of PACAP-IR neurons after 24 h in culture; a result indicating that the generation and secretion of these factors did not stimulate PACAP expression. The presence of 20 nM PACAP or 10 muM forskolin increased the percentage of PACAP-IR cardiac neurons in 24 h cultures, but not in 72 h cultures. Neither treatment enhanced the number of VIP-IR neurons. The addition of the PACAP selective receptor (PAC(1)) receptor antagonist, M65 (100 nM) suppressed the 20 nM PACAP-induced increase in percentage of PACAP-IR cells in 24 h cultures indicating the effect of PACAP was mediated through the PAC(1) receptor. However, 100 nM M65 had no effect on the percentage of PACAP-IR cells in either 24 or 48 h cultures not treated with exogenous PACAP, suggesting that endogenous release of PACAP likely did not contribute to the enhanced peptide expression. We postulate that the enhanced PACAP expression, which occurs in response to injury is facilitated in the explant cultured cardiac ganglia by the loss of a target-derived inhibitory factor, very likely neurturin. In intact tissues the presence of neurturin would normally suppress PACAP expression. Lastly, our results indicate that many common trophic factors do not enhance PACAP expression in the cultured cardiac neurons. However, the stimulatory role of an, as yet, unidentified factor cannot be excluded.
 ...
PMID:Regulation of neuronal pituitary adenylate cyclase-activating polypeptide expression during culture of guinea-pig cardiac ganglia. 1736 46

Pathology are still progressive and cumulative in the remission course of relapsing-remitting MS (RRMS), thus drug treatment during the remission period may play a great role for the regeneration of the myelin sheath. C57BL/6 mice were fed with cuprizone (CPZ, 0.2% w/w) for 5 weeks to induce acute demyelination and oligodendrocytes degeneration, after which CPZ was withdrawn to allow recovery. Icariin (ICA, 6.25, 12.5 and 25mg/kg/day), vehicle (0.5% sodium carboxymethyl cellulose solution) or water was administrated orally to mice for 1 week after CPZ withdrawal. Luxol-fast blue (LFB), immunohistochemical or immunofluorescence staining was used to detect morphological and biological changes in the brains. CPZ administration for 5 weeks resulted in completely demyelination and remyelination occurred when CPZ was withdrawn. ICA treatment during the recovery period for 1 week significantly improved myelin restoration, enhanced NF200-positive axons repair, increased the number of APC+/Olig2+ mature oligodendrocytes and prevented neuron-derived neurotrophic factor such as nerve growth factor (NGF) loss. Our results demonstrated that ICA treatment during the recovery period promotes remyelination and axon rewrapped, at least, in part, by promoting oligodendrogenesis and neurotrophic factor production.
 ...
PMID:Icariin enhances remyelination process after acute demyelination induced by cuprizone exposure. 2816 Nov 97