Expression of adenosine receptors in human retinal pigment epithelium cells in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Adenosine receptors (ADORs) have been reported to play a role in experimental myopia. This study aimed to determine the distribution of ADORs in human retinal pigment epithelium (RPE) cells cultured in vitro.</p><p><b>METHODS</b>Human RPE cells (cell line D407) were cultured in vitro. ADOR mRNA in RPE was detected by reverse transcription polymerase chain reaction. ADOR protein expression in RPE was confirmed by Western blotting analysis of cell lysates. Confocal fluorescence microscopy was used to study the subcellular distribution of ADORs.</p><p><b>RESULTS</b>All four subtypes of ADORs mRNA and protein were expressed in human RPE. This was confirmed by Western blotting analysis. The ADOR subtypes were differently distributed within the cells. ADORA1 was expressed in nucleus, perinucleus and cytoplasm of RPE. ADORA2A was concentrated mainly in one side of the perinucleus and cytoplasm of RPE. ADORA2B was strongly expressed in the nucleus, perinucleus and the cytoplasm, and ADORA3 was expressed weakly in the cytoplasm of RPE.</p><p><b>CONCLUSIONS</b>ADORs are expressed in human RPE. The different distribution at the subcellular level suggests different functions of ADOR subtypes.</p>

Expression of 5 muscarinic receptor subtypes in the scleral tissue of immature guinea pigs / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of 5 muscarinic receptor subtypes in the scleral tissue of immature guinea pigs.</p><p><b>METHODS</b>The scleral tissue was collected from six 2-week-old pigmented guinea pigs to determine mRNA expressions of the muscarinic receptors with RT-PCR. Immunofluorescence was used to observe the protein expressions of the 5 muscarinic receptor subtypes.</p><p><b>RESULTS</b>The mRNAs of the 5 muscarinic receptor subtypes were all detected in the scleral tissue, and the mRNA expression was the highest for M1 subtype. Green fluorescence of M1 to M5 subtypes surrounding the fibroblast nuclei were found in the scleral matrix using laser confocal microscopy.</p><p><b>CONCLUSION</b>Five muscarinic receptor subtypes are present in the scleral tissues of immature guinea pigs, indicating the involvement of the muscarinic receptors in eye growth regulation.</p>

Changes of nitric oxide synthase and cyclic guanosine mono-phosphate in form deprivation myopia in guinea pigs / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The form deprivation (FD) reduces spatial contrasts and induces myopia. Nitric oxide and cyclic guanosine monophosphate (cGMP) are involved in visual signal transmission. This study investigated changes in nitric oxide synthase (NOS) activity and cGMP concentration in ocular tissues in acute and chronic form deprivation myopia.</p><p><b>METHODS</b>Guinea pigs had one eye covered by translucent glass for 7, 14 or 21 days. Untreated litter mates were used as controls. NOS activity and cGMP concentrations in the retinal, choroidal and scleral tissues of FD eyes and control eyes were analyzed by radioimmunoassay after various durations of FD. The expression of NOS subtypes was identified by immunohistochemistry.</p><p><b>RESULTS</b>Myopia was successfully induced in FD eyes after 14 days. Compared with control groups, the retinal NOS activity and cGMP concentrations in the FD eyes significantly increased after 14 and 21 days while the retinal NOS activity in the FD eyes was transiently suppressed by 7 days of FD. The NOS activity and cGMP concentrations of choroid and sclera in the FD eyes were higher than in the control groups at 21 days. The three isoenzymes of nitric oxide synthase were detected in the ocular tissues of guinea pigs.</p><p><b>CONCLUSIONS</b>The NOS activity and cGMP concentrations were upregulated after chronic FD and the retinal NOS activity was transiently suppressed at acute FD. The function of elevated NOS activity may be mediated by cGMP.</p>