Overexpression of TRPV1 activates autophagy in human lens epithelial cells under hyperosmotic stress through Ca2+-dependent AMPK/mTOR pathway.

AIM: To explore whether autophagy functions as a cellular adaptation mechanism in lens epithelial cells (LECs) under hyperosmotic stress. METHODS: LECs were treated with hyperosmotic stress at the concentration of 270, 300, 400, 500, or 600 mOsm for 6, 12, 18, 24h in vitro. Polymerase chain reaction (PCR) was employed for the mRNA expression of autophagy-related genes, while Western blotting detected the targeted protein expression. The transfection of stub-RFP-sens-GFP-LC3 autophagy-related double fluorescence lentivirus was conducted to detect the level of autophagy flux. Scanning electron microscopy was used to detect the existence of autolysosome. Short interfering RNA of autophagy-related gene (ATG) 7, transient receptor potential vanilloid (TRPV) 1 overexpression plasmid, related agonists and inhibitors were employed to their influence on autophagy related pathway. Flow cytometry was employed to test the apoptosis and intracellular Ca2+ level. Mitochondrial membrane potential was measured by JC-1 staining. The cell counting kit-8 assay was used to calculate the cellular viability. The wound healing assay was used to evaluate the wound closure rate. GraphPad 6.0 software was utilized to evaluate the data. RESULTS: The hyperosmotic stress activated autophagy in a pressure- and time-dependent manner in LECs. Beclin 1 protein expression and conversion of LC3B II to LC3B I increased, whereas sequestosome-1 (SQSTM1) protein expression decreased. Transient Ca2+ influx was stimulated caused by hyperosmotic stress, levels of mammalian target of rapamycin (mTOR) phosphorylation decreased, and the level of AMP-activated protein kinase (AMPK) phosphorylation increased in the early stage. Based on this evidence, autophagy activation through the Ca2+-dependent AMPK/mTOR pathway might represent an adaptation process in LECs under hyperosmotic stress. Hyperosmotic stress decreased cellular viability and accelerated apoptosis in LECs and cellular migration decreased. Inhibition of autophagy by ATG7 knockdown had similar results. TRPV1 overexpression increased autophagy and might be crucial in the occurrence of autophagy promoted by hyperosmotic stress. CONCLUSION: A combination of hyperosmotic stress and autophagy inhibition may be a promising approach to decrease the number of LECs in the capsular bag and pave the way for improving prevention of posterior capsular opacification and capsular fibrosis.

Staged lensectomy and vitrectomy in the management of stage 5C retinopathy of prematurity with corneal opacification: long-term follow up.

AIM: To verify the feasibility and safety of staged lensectomy and vitrectomy in stage 5C retinopathy of prematurity (ROP) with corneal opacification. METHODS: This was a retrospective, interventional, consecutive case series. Twenty-two eyes of 18 stage 5C ROP patients with corneal opacification were included. Regular combined lensectomy and vitrectomy were not prescribed due to the invisible fundus. Staged lensectomy and posterior vitrectomy were performed. The anatomical and visual outcomes were reviewed at the final follow-up visit. RESULTS: The mean gestational age of ROP patients was 29.3±1.6wk (range: 27-32wk), comprising 8 males and 10 females. The average birth weight was 1363.0±300.0 g. All the eyes had corneal opacity and flat or disappeared anterior chambers pre-operatively. Two eyes had complicated cataract and 7 eyes had retrolental fibroplasia. Six eyes had posterior pupillary synechiae or membranes. Seven (31.8%) eyes had vascularly active retinas. The average interval between two procedures was 6.8±4.6mo (2.5-18.5mo). After surgeries, all the patients had normal anterior chambers. Fourteen eyes had clear corneas. The intraocular pressure of 3 eyes with glaucoma was controlled by medication. Two eyes had ocular phthisis. The retina was reattached in 3 eyes and partially attached in 11 eyes. Visual acuity ranged from no light perception to hand motion. CONCLUSION: Staged lensectomy and vitrectomy are procedures that can halt progression to further complications and preserve some useful eyesight in stage 5C ROP patients with corneal opacification. The earlier the lensectomy is performed, the better the prognosis is.

Prophylactic juxtapapillary laser photocoagulation in pediatric morning glory syndrome.

AIM: To determine the anatomic and visual outcomes of prophylactic juxtapapillary laser photocoagulation treatment alone in the prevention of retinal detachment (RD) in a cohort of pediatric patients diagnosed with morning glory syndrome (MGS). METHODS: A total of 24 eyes of 22 consecutive patients aged 0-15y diagnosed with MGS treated with prophylactic juxtapapillary laser photocoagulation alone were reviewed. Data including demographics, ocular examination, anatomic and visual outcomes, following treatment and complications were collected. RESULTS: Two patients had bilateral laser treatment and 20 had monocular laser treatment. The age at treatment of 13 (59.1%) patients was less than 12mo. The presenting symptoms included strabismus (6/22, 27.3%), decreased vision (2/22, 9.1%), and routine fundus screening (14/22, 63.6%). Fifteen (68.2%) patients underwent cranial magnetic resonance imaging (MRI) examinations, and 3 of those 15 (20.0%) had abnormal findings in the nervous system. Based on preoperative wide-field fundus photography and B-scan echography, all (100.0%) eyes had no obvious RD. On postoperative 1mo and 6mo and the following follow-ups, the anatomic outcomes of all eyes remained stable. The mean follow-up duration was 27.7±17.5mo. No severe complications were found. Preoperative visual acuity acquired from 2 (9.1%) patients ranged from light perception to 20/200. Postoperative acuity acquired from 11 (50.0%) patients ranged from light perception to 20/125. CONCLUSION: The preliminary anatomic and visual outcomes of prophylactic juxtapapillary laser treatment alone in pediatric MGS patients are relatively stable in a short-term follow-up. Further long-term clinical observation will be needed to confirm its efficacy and safety.

Combined intra-arterial chemotherapy and intravitreal melphalan for the treatment of advanced unilateral retinoblastoma.

AIM: To evaluate the efficacy and safety of combined intra-arterial chemotherapy (IAC) and intravitreal melphalan (IVM) for the treatment of advanced unilateral retinoblastoma. METHODS: This retrospective study involved 30 consecutive eyes from 30 Chinese patients with advanced unilateral retinoblastoma. All patients were initially treated with IAC combined with IVM. The clinical status and complications were recorded at each visit. RESULTS: The International Intraocular Retinoblastoma Classification groups were D in 23 eyes and E in 7 eyes. All eyes showed severe cloud vitreous seeds at the first visit. The mean number of IAC cycles and intravitreal injections was 3.2 (range, 3-4) and 6 (range, 1-14), respectively. The median follow-up time was 29mo (range, 7-36mo). Treatment success with regression of the retinal tumor and vitreous seeds was achieved in 29 of 30 eyes (96.7%). Globe salvage was attained in 93.3% (28/30) eyes, and enucleation (n=2) was performed due to neovascular glaucoma and persistent vitreous hemorrhage. Complications included retinal pigment epithelium (RPE) atrophy (n=13; 43%), mild lens opacity (n=7; 23%), vitreous hemorrhage (n=5; 17%) and rhegmatogenous retinal detachment (n=1; 3%). No extraocular tumor extension or metastasis occurred. CONCLUSION: Combined IAC and IVM is effective and safe for the treatment of advanced unilateral retinoblastoma.