Incidence and analysis of intraoperative complications in femtosecond laser-assisted cataract surgery: a large-scale cohort study to establish the learning curve.

AIMS: To assess the safety of femtosecond laser-assisted cataract surgery (FLACS) based on surgical parameters and intraoperative complications analysis and to determine the length of the learning curve for FLACS. METHODS: A prospective consecutive cohort study was conducted on Chinese patients who underwent either FLACS (3289 cases) or contemporaneous conventional phacoemulsification cataract surgery (2130 cases). The laser group was divided into four subgroups in chronological order. We recorded intraoperative complication incidences and compared with surgical parameters between groups. Subgroup analysis was conducted to explore the learning curve of FLACS. RESULTS: The laser group had a 4.93% incidence of incomplete capsulotomies and a 1.22% incidence of anterior capsule tears. Subgroup analysis showed significant differences in 8 aspects between the first 250 cases (50 cases per surgeon) and the last 2539 cases, but only 2 aspects differed between the second 250 cases (50 cases per surgeon) and the last 2539 cases. There were no significant differences between the third 250 cases (50 cases per surgeon) and the last 2539 cases. CONCLUSIONS: The intraoperative complications of FLACS were reported, and the learning curve is associated with a significant reduction in the incidence of intraoperative complications. The length of the basic learning curve of FLACS is 100 cases, and the length of the advanced learning curve was 150 cases. This study demonstrated that FLACS is characterised by a relatively straightforward and secure operative technique.

Activation of METTL3 Promotes White Adipose Tissue Beiging and Combats Obesity.

The induction of beige adipocytes in white adipose tissue (WAT), also known as WAT beiging, improves glucose and lipid metabolism. However, the regulation of WAT beiging at the posttranscriptional level remains to be studied. Here, we report that METTL3, the methyltransferase of N6-methyladenosine (m6A) mRNA modification, is induced during WAT beiging in mice. Adipose-specific depletion of the Mettl3 gene undermines WAT beiging and impairs the metabolic capability of mice fed with a high-fat diet. Mechanistically, METTL3-catalyzed m6A installation on thermogenic mRNAs, including Krüppel-like factor 9 (Klf9), prevents their degradation. Activation of the METTL3 complex by its chemical ligand methyl piperidine-3-carboxylate promotes WAT beiging, reduces body weight, and corrects metabolic disorders in diet-induced obese mice. These findings uncover a novel epitranscriptional mechanism in WAT beiging and identify METTL3 as a potential therapeutic target for obesity-associated diseases. ARTICLE HIGHLIGHTS: METTL3, the methyltransferase of N6-methyladenosine (m6A) mRNA modification, is induced during WAT beiging. Depletion of Mettl3 undermines WAT beiging and impairs thermogenesis. METTL3-mediated m6A installation promotes the stability of Krüppel-like factor 9 (Klf9). KLF9 rescues impaired beiging elicited by Mettl3 depletion. Pharmaceutical activation of the METTL3 complex by its chemical ligand methyl piperidine-3-carboxylate induces WAT beiging. Methyl piperidine-3-carboxylate corrects obesity-associated disorders. The METTL3-KLF9 pathway may serve as a potential therapeutic target for obesity-associated diseases.

Discovery of the hidden coding information in cancers: Mechanisms and biological functions.

Most proteins are derived from the translation of coding sequence (CDS) in messenger RNAs (mRNAs). However, accumulating evidence has revealed an unexpected abundance of translation in putative non-coding genomes, especially 5' untranslated region (5' UTR) of mRNAs or non-coding RNA species (ncRNA) such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). Notably, many of these UTR- or ncRNA-encoded micropeptides/proteins play important roles in human malignancies. In this review, we describe recent advances in our understanding of the mechanisms underlying the translation of non-coding regions or ncRNAs and the methods to discover the hidden coding information. Furthermore, we summarize the biological functions of UTR- or ncRNA-encoded micropeptides/proteins in cancers and discuss their potential as clinical biomarkers for cancer diagnosis and as therapeutic targets for cancer treatment.

Drug-eluting intraocular lens with sustained bromfenac release for conquering posterior capsular opacification.

Cataract is the leading cause of visual impairment, and posterior capsular opacification (PCO) is the most common long-term complication of modern cataract surgery, which can cause severe visual impairment after surgery. The proliferation, migration, and epithelial-mesenchymal transition (EMT) of residual lens epithelial cells (LECs) stimulated by growth factors and cytokines, are the key pathological mechanisms involved in the development of PCO. This study demonstrated that non-steroidal anti-inflammatory drug (NSAID), bromfenac, was capable of effectively inhibiting cell migration, overexpression of EMT markers, such as fibronectin (FN), matrix metalloproteinase 2 (MMP2), α-smooth muscle actin (α-SMA), and transcription factor Snail, and extracellular signal-regulated kinase (ERK)/glycogen synthase kinase-3ß (GSK-3ß) signaling induced by transforming growth factor-ß2 (TGF-ß2) in vitro. The inhibitory effect of bromfenac on TGF-ß2-induced EMT was also verified on a primary lens epithelial cell model using human anterior capsules. Furthermore, based on ultrasonic spray technology, we developed a drug-eluting intraocular lens (IOL) using poly (lactic-co-glycolic acid) (PLGA) with sustained bromfenac release ability for the prevention of PCO development. In the rabbit models of cataract surgery, bromfenac-eluting IOL exhibited remarkable PCO prevention and inflammation suppression effects with excellent biocompatibility. In conclusion, bromfenac can inhibit TGF-ß2-induced cell migration and the EMT of LECs via ERK/GSK-3ß/Snail signaling. The present study offers a novel approach for preventing PCO through PLGA-based drug sustained-release IOLs.

Clinical Characteristics and Visual Outcomes in Patients with Intralenticular Foreign Bodies with Self-Sealing Corneal Penetrating Wounds.

PURPOSE: Siderosis bulbi may occur as a result of retained intralenticular foreign bodies (ILFBs) that were missed during examination in patients with self-sealing wounds and without a significant decrease in visual acuity. This study aimed to explore the clinical characteristics and visual outcomes of ILFBs with self-sealing corneal penetrating wounds. METHODS: Fifteen eyes of 15 patients with ILFBs and self-sealing corneal penetrating wounds, seen between October 2014 and September 2019, were retrospectively analyzed. Data regarding the patient demographics, clinical features, surgical procedure, and initial and final best-corrected visual acuity (BCVA) were analyzed. RESULTS: All patients were male with a mean age of 41 years. The foreign bodies passed through the cornea, sometimes through the iris, through the anterior capsule, and finally localized in the lens. All ILFBs were pointed and metallic objects and were successfully removed with phacoemulsification and posterior chamber intraocular lens (IOL) implantation. Anterior capsule violation was found in three eyes, but no posterior capsule rupture was found. The IOL was placed in a capsule bag in all the cases. The BCVA ranged from 20/200 to 20/25 preoperatively and improved to between 20/32 and 20/20 at the last follow-up visit. The IOLs were well-centered. Apart from posterior capsule opacity in four eyes, no other postoperative complications were found. CONCLUSIONS: In patients with a pointed metallic ILFB and self-sealing corneal penetrating wounds (with or without cataracts), early diagnosis and removal of the metallic ILFB combined with lens removal and IOL implantation may avoid late complications and achieve good visual outcomes.

Case Report: Self-Resolved Macular Edema Secondary to Congenital Retinal Macrovessels.

PURPOSE: To report a case of macular edema secondary to congenital retinal macrovessels (CRMs), which resolved spontaneously without any treatment. OBSERVATIONS: A 39-year-old female presented with blurry vision of the right eye for one day. Fundus examination revealed a branch of artery and vein of the inferior retinal arcade crossing the horizontal raphe. Optical coherence tomography (OCT) through the fovea showed cystoid macular edema in the outer plexiform layer. However, no leakage of the vessels was noticed by fundus fluorescein angiography (FFA). Observation was recommended with close follow-up. Two weeks later, the patient returned with good visual acuity, and the macular edema was resolved spontaneously. CONCLUSIONS: Macular edema is a possible complication of CRM by increasing retinal capillary hydrostatic pressure. Treatment is not necessary for this kind of macular edema if no leakage of the vessels is noticed on FFA.

Comparative clinical outcomes of Tecnis toric IOL implantation in femtosecond laser-assisted cataract surgery and conventional phacoemulsification surgery.

AIM: To compare the short-term visual outcomes, residual refractive cylinder, and rotation stability after Tecnis toric intraocular lens (IOL) implantation during femtosecond laser-assisted cataract surgery (Femto phaco) and conventional phacoemulsification surgery (Conventional phaco). METHODS: In a prospective cohort study, Conventional phaco and Femto phaco (anterior capsulotomy and lens fragmentation by a femtosecond laser) with Tecnis toric IOL implantation were performed in 40 eyes from 36 patients and 37 eyes from 33 patients, respectively. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refraction were assessed during 1d, 1wk, and 1mo follow-ups. The orientation of the Tecnis Toric IOL was evaluated during 1wk and 1mo follow-ups. RESULTS: There were no significant differences in UDCA or CDVA between two groups at 1mo postoperatively, though relatively more subjects had UDVA values of 20/25 or better in Femto phaco group than in the Conventional group (P>0.05). A lower but not significantly lower rate of having more than 5° of IOL rotation was observed in Femto phaco group at the 1-month follow-up, while a significant lower rate of residual astigmatism of ≤1 D was observed in Femto phaco group. CONCLUSION: The Femto phaco group has significantly more subjects with the residual astigmatism of ≤1 D, but there are no significant differences in rotation stability and visual outcomes as compared with the Conventional phaco group after the application of the Tecnis toric IOL in this cohort.

Multiple cytokine analyses of aqueous humor from the patients with retinitis pigmentosa.

PURPOSE: Cataracts are the most common eye complications of retinitis pigmentosa (RP). This study aimed to investigate the cytokine profiles of the aqueous humor of RP with cataracts. METHODS: The aqueous humor was collected from RP eyes with cataract (RP group, n = 20) and age-related cataract eyes (ARC group, n = 20) during cataract surgery. The levels of 37 mediators were measured with multiplex fluorescent bead-based immunoassay and compared across groups. The correlation among chemokines, growth factors, and cytokines was analyzed with Spearman's rank correlation coefficient. RESULTS: Twelve cytokines (IL-1α, IL-1ß, IL-4, IL-10, TNF-α, IFN-γ, EGF, GM-CSF, PDGF-AB/BB, TGF-α, BMP-9, and E-selection) were below the limit of detection, and the detection rate of IL-6 was significantly higher in RP group than in the ARC group (P < 0.01). Compared with those in the control group, the aqueous humor levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-(IL-)8, interferon gamma-induced protein (IP)-10, hepatocyte growth factor (HGF), platelet-derived growth factor AA (PDGF-AA), matrix metalloproteinase-2 (MMP-2), MMP3, MMP-7, MMP-8, plasminogen activator inhibitor-1 (PAI-1), and thrombospondin-2 (TSP-2) in the RP group increased significantly (P < 0.01). A lower level of BMP-4 in the aqueous humor was observed in the RP patients than in the controls (P < 0.05). CONCLUSIONS: Significantly increased levels of PDGF-AA, MMP2, MMP3, MMP-7, MMP-8, PAI-1, and TSP-2 and lower levels of BMP-4 were found in the aqueous humor of RP patients. This result indicates a disturbance of the extracellular matrix (ECM) and cytokines in RP patients and suggests a possible role of these cytokines in the pathogenesis of capsular contraction syndrome (CCS) in RP patients.

Bromfenac Inhibits TGF-ß1-Induced Fibrotic Effects in Human Pterygium and Conjunctival Fibroblasts.

Purpose: Nonsteroidal anti-inflammatory drugs (NSAIDs) have shown antifibrotic effects on several diseases. The aims of the present in vitro study were to investigate the antifibrotic effects of bromfenac (a kind of NSAID) on primary human pterygium fibroblasts (HPFs) and primary human conjunctival fibroblasts (HConFs), as well as to explore the possible mechanisms of these effects. Methods: The cells used in this study were primary HPFs and HConFs, and profibrotic activation was induced by transforming growth factor-beta1 (TGF-ß1). Western blot, quantitative real-time PCR, and immunofluorescence (IF) assays were used to detect the effects of TGF-ß1 and bromfenac on the synthesis of fibronectin (FN), type III collagen (COL3), and alpha-smooth muscle actin (α-SMA) in HPFs and HConFs; the changes of signaling pathways were detected by Western blot; cell migration ability was detected by wound healing assay; cell proliferation ability was detected by CCK-8 assay; and pharmaceutical inhibitions of the downstream signaling pathways of TGF-ß1 were used to assess their possible associations with the effects of bromfenac. Results: Bromfenac suppressed the TGF-ß1-induced protein expression of FN (0.59 ± 0.07 folds, P = 0.008), COL3 (0.48 ± 0.08 folds, P = 0.001), and α-SMA (0.61 ± 0.03 folds, P = 0.008) in HPFs. Bromfenac also attenuated TGF-ß1-induced cell migration (0.30 ± 0.07 folds, P < 0.001), cell proliferation (0.64 ± 0.03 folds, P = 0.002) and the expression levels of p-AKT (0.66 ± 0.08 folds, P = 0.032), p-ERK1/2 (0.69 ± 0.11 folds, P = 0.003), and p-GSK-3ß-S9 (0.65 ± 0.10 folds, P = 0.002) in HPFs. PI3K/AKT inhibitor (wortmannin) and MEK/ERK inhibitor (U0126) reduced the TGF-ß1-induced synthesis of FN, COL3, and α-SMA in HPFs. All the results were similar in HConFs. Conclusions: Bromfenac protects against TGF-ß1-induced synthesis of FN, α-SMA, and COL3 in HPFs and HConFs at least in part by inactivating the AKT and ERK pathways.

Thioredoxin Binding Protein-2 Regulates Autophagy of Human Lens Epithelial Cells under Oxidative Stress via Inhibition of Akt Phosphorylation.

Oxidative stress plays an essential role in the development of age-related cataract. Thioredoxin binding protein-2 (TBP-2) is a negative regulator of thioredoxin (Trx), which deteriorates cellular antioxidant system. Our study focused on the autophagy-regulating effect of TBP-2 under oxidative stress in human lens epithelial cells (LECs). Human lens epithelial cells were used for cell culture and treatment. Lentiviral-based transfection system was used for overexpression of TBP-2. Cytotoxicity assay, western blot analysis, GFP/mCherry-fused LC3 plasmid, immunofluorescence, and transmission electronic microscopy were performed. The results showed that autophagic response of LECs with increased LC3-II, p62, and GFP/mCherry-LC3 puncta (P < 0.01) was induced by oxidative stress. Overexpression of TBP-2 further strengthens this response and worsens the cell viability (P < 0.01). Knockdown of TBP-2 attenuates the autophagic response and cell viability loss induced by oxidative stress. TBP-2 mainly regulates autophagy in the initiation stage, which is mTOR-independent and probably caused by the dephosphorylation of Akt under oxidative stress. These findings suggest a novel role of TBP-2 in human LECs under oxidative stress. Oxidative stress can cause cell injury and autophagy in LECs, and TBP-2 regulates this response. Hence, this study provides evidence regarding the role of TBP-2 in lens and the possible mechanism of cataract development.

Regulation of angiogenin expression and epithelial-mesenchymal transition by HIF-1α signaling in hypoxic retinal pigment epithelial cells.

Choroidal neovascularization (CNV) is a major cause of vision loss in many retinal diseases. Hypoxia is determined to be a key inducer of CNV and hypoxia-inducible factor-1 (HIF-1) is an important transcription factor. Epithelial-mesenchymal transition (EMT) and the synthesis of proangiogenic cytokines make great contributions to the development of CNV. In the present study, the role of HIF-1α signaling in the regulation of angiogenin (ANG) expression and EMT in hypoxic retinal pigment epithelial cells was investigated. A significant elevation expression of ANG expression level in a mouse model of laser-induced CNV was demonstrated. In a hypoxic model of ARPE-19, an increased expression level of ANG and induction of EMT accompanied with stabilization and nucleus translocation of HIF-1α. Blockage of HIF-1α signaling resulted in inhibition of high expression of ANG and EMT features. The direct interaction between HIF-1α and ANG promoter region was identified by ChIP-qPCR. The association of RNase 4 mRNA level with HIF-1α signaling was also clarified in APRE-19. Moreover, the exogenous ANG translocated into the nucleus, enhanced 45S rRNA transcription, promoted cell proliferation and tube formation in human retinal microvascular endothelial cells. In conclusion, the hypoxic conditions regulate the expression of ANG and EMT via an activation of HIF-1α signaling. It provides molecular evidence for potential therapy strategies of treating CNV.

Comparative outcomes of femtosecond laser-assisted cataract surgery and manual phacoemusification: a six-month follow-up.

BACKGROUND: To explore efficacy and safety outcomes in patients undergoing femtosecond laser-assisted cataract surgery (FLACS) versus manual phacoemulsification cataract surgery (PCS). DESIGN: Prospective consecutive nonrandomized comparative cohort study. PARTICIPANTS: A total of 124 eyes from 106 patients (70 in FLACS and 54 in PCS). METHODS: Comparison of FLACS with PCS over 6 months. MAIN OUTCOME MEASURES: Macular central subfield thickness (CST), cube volume (CV), cube average thickness (CAT), endothelial cell density (ECD), central corneal thickness (CCT) and photon count value (PCV). RESULTS: CST, CV and CAT increased postoperatively, which did not return to preoperative levels by 6 months. The values were similar between groups throughout the follow-up, and comparison of changes from baseline also showed no significant difference. Preoperative ECD showed significant difference, which decreased postoperatively and remained stable during follow-up, being lowest at 1 month. FLACS had greater endothelial cell loss than PCS, which was not significant. CCT in both groups increased, reaching maximum on day one and tended to decrease thereafter. No significant differences were found regarding postoperative values and the mean increase. In both groups, mean PCV increased from preoperatively to day one, week one and month one. Flare values in FLACS were lower than PCS, reaching statistical significance at 6 months (P = 0.001). However, the differences in changes of PCV were not significantly different at any visit. CONCLUSIONS: Both FLACS and PCS achieved similar safety and efficacy outcomes for performing cataract surgery. Flare values in eyes with FLACS were lower than those with PCS at 6 months postoperatively.

A novel FBN1 missense mutation (p.C102Y) associated with ectopia lentis syndrome in a Chinese family.

AIM: To characterize the disease-causing mutations in a Chinese family with ectopia lentis syndrome (ELS). METHODS: Patients and their family members were given complete physical, ophthalmic, and cardiovascular examinations. Genomic DNA samples were extracted from the peripheral blood of the pedigree members and 100 healthy controls. Mutation screening was performed in the fibrillin-1 (FBN1) gene by bi-directional sequencing of the amplified products. The mutation was analyzed using two bioinformatics methods. RESULTS: A novel heterozygous c.305G>A mutation in exon 3 of FBN1 was detected. As a result of this change, a highly conserved cysteine residue was replaced by a tyrosine residue (p.C102Y). Another mutation was found in the same exon (c.303T>C), which did not change the amino acid sequence. Both mutations were discovered in each affected individual, but not in the unaffected family members, or in 100 ethnically matched controls. A bioinformatics analysis predicted that mutation p.C102Y would affect protein function. CONCLUSION: In the first epidermal growth factor-like module, we identified a novel FBN1 mutation (p.C102Y), which caused ELS in the family. Our study presented a unique phenotype, including some distinct ophthalmic findings, such as hypoplasia of the iris and anisometropia. Our results expanded the mutation spectrum of FBN1 and enriched the overall knowledge of genotype-phenotype correlations due to FBN1 mutations.

Evaluation of dry eye after femtosecond laser-assisted cataract surgery.

PURPOSE: To compare dry-eye signs and symptoms after femtosecond laser-assisted cataract surgery and conventional phacoemulsification. SETTING: Eye Center of the 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China. DESIGN: Prospective consecutive nonrandomized comparative cohort study. METHODS: Consecutive patients who had femtosecond laser-assisted or phacoemulsification cataract surgery were assessed. Dry-eye markers including the ocular surface disease index (OSDI) and subjective symptom questionnaire, tear-film assessment using Keratograph 4 corneal topography, Schirmer testing I, and fluorescein staining were sequentially evaluated preoperatively and postoperatively at 1 day, 1 week, and 1 month. RESULTS: The study recruited 137 eyes (137 patients) with similar baseline characteristics. Most patients developed dry eye postoperatively. Subjective symptoms and fluorescein staining scores elevated from baseline, tear breakup time and Schirmer testing I values decreased postoperatively, which peaked at 1 week and did not return to baseline within 1 month. There were no significant differences between the 2 groups (all P > .05) except for a higher fluorescein staining score in the femtosecond group at 1 day (P = .001), 1 week (P = .047), and 1 month (P = .025). OSDI score and subjective symptoms were greater in the laser group at 1 week (P = .014 and P = .016, respectively). Subgroup analysis showed obvious worsening by fluorescein staining at 1 day (P = .016) and 1 month (P = .009) in preoperative dry-eye patients. CONCLUSIONS: Both methods worsened dry eye postoperatively. Femtosecond-assisted surgery had a higher risk for staining and dry-eye symptoms. Patients with preexisting dry eye who had femtosecond-assisted surgery had more severe ocular surface staining than those having conventional surgery. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

The effects of postmenopausal hormone use on cataract: a meta-analysis.

BACKGROUND: Cataract is the leading cause of blindness worldwide. Many observational studies assessed the relationship between postmenopausal hormone replacement therapy (HRT) and risk of cataract development, but the reported results were controversial. The aim of present meta-analysis was to evaluate the association of postmenopausal hormone replacement therapy with risk of cataract development. METHODS: The eligible observational studies, including cross-sectional, case-control and cohort studies, were identified by searching PubMed and Embase during March of 2013. Either a fixed- or a random-effects model was used to calculate the pooled odds ratio (OR) with its 95% confidence interval (95%CI). Subgroup analysis on cataract types was performed. RESULTS: A total of four cohort and five case-control or cross-sectional studies were finally included into this meta-analysis. Overall, a significant decreased risk of developing any type of cataract was found in ever HRT group as compared with non-HRT group among cohort studies (OR 0.83; 95%CI: 0.71,0.97) and case-control or cross-sectional studies (OR 0.74; 95%CI: 0.59,0.93). Subgroup analysis on cataract types determined that the significantly decreased risk of nuclear cataract in current HRT group (OR 0.72; 95%CI: 0.61,0.85) and also a critically reduced risk of nuclear cataract in ever HRT group (OR 0.80; 95% CI: 0.64,1.01) were found among case-control or cross-sectional studies, as compared with non-HRT group. No association of HRT with risk of cortical and posterior subcapsular cataract was observed. CONCLUSIONS: The results of present meta-analysis indicate that postmenopausal hormone use may play a protective role in cataract development.

Identification of estrogen receptor-related receptor gamma as a direct transcriptional target of angiogenin.

Nuclear translocation of angiogenin (ANG) is essential for the proliferation of its target cells. ANG promotes rRNA synthesis, while whether it regulates mRNA transcription remains unknown. Using the chromatin immunoprecipitation method, we have identified 12 ANG-binding sequences. One of these sequences lies in the estrogen receptor-related receptor gamma (ERRγ) gene which we designated as ANG-Binding Sequence within ERRγ (ABSE). ABSE exhibited ANG-dependent repressor activity in the luciferase reporter system. Down-regulation of ANG increased ERRγ expression, and active gene marker level at the ABSE region. The expression levels of ERRγ targets genes, p21(WAF/CIP) and p27(KIP1), and the occupation of ERRγ on their promoter regions were increased in ANG-deficient cells accordingly. Furthermore, knockdown of ERRγ promoted the proliferation rate in ANG-deficient breast cancer cells. Finally, immunohistochemistry staining showed negative correlation between ANG and ERRγ in breast cancer tissue. Altogether, our study provides evidence that nuclear ANG directly binds to the ABSE of ERRγ gene and inhibits ERRγ transcription to promote breast cancer cell proliferation.

Study of oxidative stress in human lens epithelial cells exposed to 1.8 GHz radiofrequency fields.

OBJECTIVES: The aims of the present study were to determine oxidative stress and to explore possible reasons of reactive oxygen species (ROS) increase in human lens epithelial (HLE) B3 cells exposed to low intensity 1.8 GHz radiofrequency fields (RF). METHODS: The HLE B3 cells were divided into RF exposure and RF sham-exposure groups. The RF exposure intensity was at specific absorption rate (SAR) of 2, 3, or 4 W/kg. The ROS levels were measured by a fluorescent probe 2'7'-dichlorofluorescin diacetate (DCFH-DA) assay in the HLE B3 cells exposed to 1.8 GHz RF for 0.5, 1, and 1.5 h. Lipid peroxidation and cellular viability were detected by an MDA test and Cell Counting Kit-8 (CCK-8) assays, respectively, in the HLE B3 cells exposed to 1.8 GHz RF for 6, 12, and 24 h, respectively. The mRNA expression of SOD1, SOD2, CAT, and GPx1 genes and the expression of SOD1, SOD2, CAT, and GPx1 proteins was measured by qRT-PCR and Western blot assays in the HLE B3 cells exposed to 1.8 GHz RF for 1 h. RESULTS: The ROS and MDA levels significantly increased (P<0.05) in the RF exposure group and that the cellular viability, mRNA expression of four genes, and expression of four proteins significantly decreased (P<0.05) compared with the RF sham-exposure group. CONCLUSIONS: Oxidative stress is present in HLE B3 cells exposed to 1.8 GHz low-intensity RF and that the increased production of ROS may be related to down-regulation of four antioxidant enzyme genes induced by RF exposure.

Nucleolar follistatin promotes cancer cell survival under glucose-deprived conditions through inhibiting cellular rRNA synthesis.

Solid tumor development is frequently accompanied by energy-deficient conditions such as glucose deprivation and hypoxia. Follistatin (FST), a secretory protein originally identified from ovarian follicular fluid, has been suggested to be involved in tumor development. However, whether it plays a role in cancer cell survival under energy-deprived conditions remains elusive. In this study, we demonstrated that glucose deprivation markedly enhanced the expression and nucleolar localization of FST in HeLa cells. The nucleolar localization of FST relied on its nuclear localization signal (NLS) comprising the residues 64-87. Localization of FST to the nucleolus attenuated rRNA synthesis, a key process for cellular energy homeostasis and cell survival. Overexpression of FST delayed glucose deprivation-induced apoptosis, whereas down-regulation of FST exerted the opposite effect. These functions depended on the presence of an intact NLS because the NLS-deleted mutant of FST lost the rRNA inhibition effect and the cell protective effect. Altogether, we identified a novel nucleolar function of FST, which is of importance in the modulation of cancer cell survival in response to glucose deprivation.