Mucin-Like Glycoprotein Associated with Photoreceptor Cells in the Postnatal Developing Rat Retina

Abstract

Purpose: To examine the developmental expression of mucin-like glycoprotein associated with photoreceptor cells (MLGAPC), and to confirm that MLGAPC with a relative mass of 120 and 135 kD correspond to the cone and rod types, respectively. Methods: We isolated the cDNA of the core protein of rat MLGAPC, prepared an anti-rat MLGAPC core protein antibody and then examined the expression of the MLGAPC core protein in postnatal developing rat retinas by means of Western blotting and immunohistochemistry. Results: On postnatal early days when cone photoreceptor cells were thought to be developing, MLGAPC was detected as a single band of 120 kD and was found to be positive in the apical portion of the neuroblastic layer. After postnatal day 7, when rod photoreceptor cells were developing, MLGAPC was detected as a minor band of 120 kD and an additional major band of 135 kD and was present throughout the differentiated photoreceptor and outer plexiform layers. Conclusions: The present findings revealed the developmental expression of MLGAPC and confirmed that MLGAPC of 120 and of 135 kD correspond to the cone and rod types, respectively. This demonstration is advantageous for studying the physiological roles of MLGAPC in the photoreceptor and outer plexiform layers, since the cone- and rod-associated glycoproteins should be investigated separately.

Further Characterization of Human Mucin-Like Glycoprotein Associated with Photoreceptor Cells by Its Introduction into Y79 Retinoblastoma Cells

“…We recently examined the developmental expression of MLGAPC in postnatal rat retinas. On Western blotting, only a 120-kD band of MLGAPC was detected at an early postnatal stage (P1-P5), when cone photoreceptor cells are thought to be already starting to develop, whereas in intense 135-kD band was additionally detectable at postnatal day 7, when rod photoreceptor cells have begun to develop [24]. These findings confirmed that the MLGAPC of 120 kD (asialo-MLGAPC) and that of 135 kD (sialo-MLGAPC) correspond to the cone and rod types, respectively.…”

The Role of Galectin-3 in Retinal Degeneration and Other Ocular Diseases: A Potential Novel Biomarker and Therapeutic Target

“…Recently, research has confirmed that Gal3 plays a key role in the inflammation induced by synaptic nucleoprotein, which is related to Parkinson's disease [99]. In the retina, the increased expression of Gal3 is related to the pathological processes of light-induced retinal degeneration and retinal detachment [100,101].…”

Aging of the Retina: Molecular and Metabolic Turbulences and Potential Interventions

“…Modifications of long-lived proteins prevent degradation and activate proinflammatory signaling, leading to harmful outcomes that correlate with progressing age. AGE can exert wider impact through the receptor for AGE (RAGE) and galectin-3, which are broadly expressed in retinal cells (Uehara et al 2001). Deglycases including DJ1/PARK7 efficiently maintain homeostasis (Chaudhuri et al 2018), yet weakening of detoxifying mechanisms can result in AGE accumulation.…”