The monoclonal antibody specific to the retinal ganglion neuronotrophic factor (RGNTF) was used to localize and quantify the presence and amount of RGNTF during the postnatal development of the visual system in the ra...The monoclonal antibody specific to the retinal ganglion neuronotrophic factor (RGNTF) was used to localize and quantify the presence and amount of RGNTF during the postnatal development of the visual system in the rat.The results showed that in the 0-1-day age group, neurons at the superficial layers and deep part of superior colliculus, and as well as retinal ganglion cells were strongly stained with their RGNTF contents quantified to be 88%, 100% and 100%, respectively. In the 5-6-day age group, RGNTF contents were significantly reduced to merely 50%, 30% and 80%, respectively.The RGNTF contents reduced further to 0% as age increased to 2 years old. A ^(32)P-DNA probe specific to the first 7 amino acid sequence of RGNTF at its N-terminal end was synthesized and used for in situ hybridization studies. The results revealed that strong hybridized signals (i.e. mRNA of RGNTF) were localized in the same neurons in the superficial layers and deep part of the superior colliculus only in the 0-1-day age group, and that no signals were found in retinae of all postnatal age groups. The significant reduction of RGNTF may be related to the RGC death during postnatal development. Neurons at the superficial layers and deep part of the superior colliculus are the sources of RGNTF for RGCs in the postnatal retina.展开更多
Ⅰ. INTRODUCTION We have isolated from the extract of rat tectum a 30-kD protein, which is capable of maintaining survival and promoting growth of retinal ganglion cells of neonatal rats, namely retinal ganglion neuro...Ⅰ. INTRODUCTION We have isolated from the extract of rat tectum a 30-kD protein, which is capable of maintaining survival and promoting growth of retinal ganglion cells of neonatal rats, namely retinal ganglion neuronotrophic factor(RGNTF). With this RGNTF, we have raised展开更多
For the first time we have shown here that the constituent from tectal extract (Te) which can support and promote the survival and growth of the retinal ganglion cell is a 30 kD protein. (i) Using MTT colorimetric mic...For the first time we have shown here that the constituent from tectal extract (Te) which can support and promote the survival and growth of the retinal ganglion cell is a 30 kD protein. (i) Using MTT colorimetric microassay to measure the optical density for the survival and growth of the cultured retinal neuron, it was found that the optical densities for the experimental cultures with either Te, or its 10-30 kD fraction, or its ≥30 kD fraction were 2-4 times that of the control culture without Te (P<0.01). This indicated that experimental cultures were more active in growth, (ii) The retinal neurons cultured on Te Phast gels showed that large retinal neurons (>18 μm) grew only on the gel region containing the 30 kD protein. The retrograde prelabelled with horseradish peroxidase (HRP) for retinal ganglion cells indicated that these surviving neurons grown on Te Phast gel were HRP positive, i.e. retinal ganglion cells, (iii) The retinal explants cultured with 30 kD gels at a close distance of 1 mm apart revealed that many neurite outgrowths, up to 400 μm, extended from the retinal explants towards 30 kD gels, and that many individual cells and tissue masses migrated out from the explants and grew onto 30 kD gels. They were stained anti-neuron specific enolase and anti-Thy 1.1 positive, indicating they are retinal ganglion cells. Therefore, we concluded that the 30 kD protein is the neuronotrophic factor in the tectal extract specific for retinal ganglion cells.展开更多
基金This research is supported by research grants from the Croucher Foundation, the University of Hong Kong, Medical Research Grantthe Research Grants Council of Hong Kong.
文摘The monoclonal antibody specific to the retinal ganglion neuronotrophic factor (RGNTF) was used to localize and quantify the presence and amount of RGNTF during the postnatal development of the visual system in the rat.The results showed that in the 0-1-day age group, neurons at the superficial layers and deep part of superior colliculus, and as well as retinal ganglion cells were strongly stained with their RGNTF contents quantified to be 88%, 100% and 100%, respectively. In the 5-6-day age group, RGNTF contents were significantly reduced to merely 50%, 30% and 80%, respectively.The RGNTF contents reduced further to 0% as age increased to 2 years old. A ^(32)P-DNA probe specific to the first 7 amino acid sequence of RGNTF at its N-terminal end was synthesized and used for in situ hybridization studies. The results revealed that strong hybridized signals (i.e. mRNA of RGNTF) were localized in the same neurons in the superficial layers and deep part of the superior colliculus only in the 0-1-day age group, and that no signals were found in retinae of all postnatal age groups. The significant reduction of RGNTF may be related to the RGC death during postnatal development. Neurons at the superficial layers and deep part of the superior colliculus are the sources of RGNTF for RGCs in the postnatal retina.
文摘Ⅰ. INTRODUCTION We have isolated from the extract of rat tectum a 30-kD protein, which is capable of maintaining survival and promoting growth of retinal ganglion cells of neonatal rats, namely retinal ganglion neuronotrophic factor(RGNTF). With this RGNTF, we have raised
基金This research is supported by research grants from the Croucher Foundation, the University of Hong Kong, Medical Research Grant Fund, and the UPGC grant 221400030.
文摘For the first time we have shown here that the constituent from tectal extract (Te) which can support and promote the survival and growth of the retinal ganglion cell is a 30 kD protein. (i) Using MTT colorimetric microassay to measure the optical density for the survival and growth of the cultured retinal neuron, it was found that the optical densities for the experimental cultures with either Te, or its 10-30 kD fraction, or its ≥30 kD fraction were 2-4 times that of the control culture without Te (P<0.01). This indicated that experimental cultures were more active in growth, (ii) The retinal neurons cultured on Te Phast gels showed that large retinal neurons (>18 μm) grew only on the gel region containing the 30 kD protein. The retrograde prelabelled with horseradish peroxidase (HRP) for retinal ganglion cells indicated that these surviving neurons grown on Te Phast gel were HRP positive, i.e. retinal ganglion cells, (iii) The retinal explants cultured with 30 kD gels at a close distance of 1 mm apart revealed that many neurite outgrowths, up to 400 μm, extended from the retinal explants towards 30 kD gels, and that many individual cells and tissue masses migrated out from the explants and grew onto 30 kD gels. They were stained anti-neuron specific enolase and anti-Thy 1.1 positive, indicating they are retinal ganglion cells. Therefore, we concluded that the 30 kD protein is the neuronotrophic factor in the tectal extract specific for retinal ganglion cells.
