1.Adult-onset foveomacular dystrophy
Kristine Corpus ; Jo Anne Hernandez ; Narciso Jr. Atienza
Philippine Journal of Ophthalmology 2010;35(1):36-39
Objective:
To describe a case of adult-onset foveomacular vitelliform dystrophy
(AOFVD).
Method:
This is a case report.
Results:
A 22-year-old female presented with painless blurring of vision and
metamorphopsia 3 days prior to consultation. There were 2 similar episodes
in the past that spontaneously resolved after 2 to 4 weeks. Visual acuity (VA)
was 20/50 in the right eye (OD) and 20/40 in the left (OS), both best corrected
to 20/25. Dilated-fundus examination revealed a discrete area of mixed hypoand hyperpigmentation 1 disc diameter over the fovea in OD and a solitary
round hypopigmented lesion with a hyperpigmented border 3 to 4 disc
diameters on the fovea in OS. Fluorescein angiography (FA) revealed an area
of hyperfluorescence surrounded by a rim of hypoflourescence in OD and an
area of blocked fluorescence with subtle hyperfluorescence superior to the
lesion in OS, both of which did not increase in size and intensity toward the
late phases. Optical coherence tomography (OCT) revealed neurosensory
detachment in both eyes. Electrooculogram (EOG) was normal with Arden
ratio of 0.91. VA returned to 20/25 in both eyes, and repeat fundus
photography showed no change in the characteristics of the lesions.
Conclusion
Differential diagnosis of a hypopigmented macular lesion in the young with
self-limited blurring of vision should include AOFVD. FA, OCT, and EOG can
help distinguish AOFVD from Best’s disease or other similar macular
conditions.
Vitelliform Macular Dystrophy
;
Bestrophins
;
Peripherins
2.MASH1 induces neuron transdifferentiation of adrenal medulla chromaffin cells.
Emin PENG ; Chengping HU ; Juntao FENG ; Ruoxi HE
Journal of Central South University(Medical Sciences) 2023;48(4):526-537
OBJECTIVES:
Nerve growth factor (NGF) induces neuron transdifferentiation of adrenal medulla chromaffin cells (AMCCs) and consequently downregulates the secretion of epinephrine (EPI), which may be involved in the pathogenesis of bronchial asthma. Mammalian achaete scute-homologous 1 (MASH1), a key regulator of neurogenesis in the nervous system, has been proved to be elevated in AMCCs with neuron transdifferentiation in vivo. This study aims to explore the role of MASH1 in the process of neuron transdifferentiation of AMCCs and the mechanisms.
METHODS:
Rat AMCCs were isolated and cultured. AMCCs were transfected with siMASH1 or MASH1 overexpression plasmid, then were stimulated with NGF and/or dexamethasone, PD98059 (a MAPK kinase-1 inhibitor) for 48 hours. Morphological changes were observed using light and electron microscope. Phenylethanolamine-N-methyltransferase (PNMT, the key enzyme for epinephrine synthesis) and tyrosine hydroxylase were detected by immunofluorescence. Western blotting was used to test the protein levels of PNMT, MASH1, peripherin (neuronal markers), extracellular regulated protein kinases (ERK), phosphorylated extracellular regulated protein kinases (pERK), and JMJD3. Real-time RT-PCR was applied to analyze the mRNA levels of MASH1 and JMJD3. EPI levels in the cellular supernatant were measured using ELISA.
RESULTS:
Cells with both tyrosine hydroxylase and PNMT positive by immunofluorescence were proved to be AMCCs. Exposure to NGF, AMCCs exhibited neurite-like processes concomitant with increases in pERK/ERK, peripherin, and MASH1 levels (all P<0.05). Additionally, impairment of endocrine phenotype was proved by a signifcant decrease in the PNMT level and the secretion of EPI from AMCCs (all P<0.01). MASH1 interference reversed the effect of NGF, causing increases in the levels of PNMT and EPI, conversely reduced the peripherin level and cell processes (all P<0.01). MASH1 overexpression significantly increased the number of cell processes and peripherin level, while decreased the levels of PNMT and EPI (all P<0.01). Compared with the NGF group, the levels of MASH1, JMJD3 protein and mRNA in AMCCs in the NGF+PD98059 group were decreased (all P<0.05). After treatment with PD98059 and dexamethasone, the effect of NGF on promoting the transdifferentiation of AMCCs was inhibited, and the number of cell processes and EPI levels were decreased (both P<0.05). In addition, the activity of the pERK/MASH1 pathway activated by NGF was also inhibited.
CONCLUSIONS
MASH1 is the key factor in neuron transdifferentiation of AMCCs. NGF-induced neuron transdifferentiation is probably mediated via pERK/MASH1 signaling.
Animals
;
Rats
;
Adrenal Medulla
;
Cell Transdifferentiation
;
Chromaffin Cells
;
Dexamethasone
;
Epinephrine/pharmacology*
;
Mammals
;
Nerve Growth Factor
;
Neurons
;
Peripherins
;
Protein Kinases
;
Tyrosine 3-Monooxygenase