Protective Effect and Mechanism of Bone Morphogenetic Protein-4 on Apoptosis of Human Lens Epithelium Cells under Oxidative Stress

Bone morphogenetic proteins (BMPs), a member of the transforming growth factor β (TGF-β) superfamily, are abundant in human ocular tissues and play an important role in lens development. Targeted deletion of BMP-4 in mice results in failure of lens placode formation. Following lens maturation, the formation of senile cataracts is demonstrably associated with free radical-related oxidative stress. Previous studies reported that BMPs play an antiapoptotic role in cells under oxidative stress, and the BMP-4 signal is important in inflammation regulation and homeostasis. BMP-4 evidently suppressed the apoptosis of human lens epithelial cells (HLECS) under oxidative stress induced by H2O2. This protective antiapoptotic effect is partly due to a decrease in caspase-3 activity and reactive oxygen species (ROS) level. Furthermore, the expression of activating transcription factor- (ATF-) 6 and Krüppel-like factor- (KLF-) 6 increased under oxidative stress and decreased after BMP-4 treatment.

Exosomal miR-29b found in aqueous humour mediates calcium signaling in diabetic patients with cataract

Background: Ca2+ was supposed to play an important role in the cataract formation. Exosomal miR-29b from aqueous humour may play an important role in the mechanism of diabetes and cataracts. The purpose of this study was to investigate the role of exosomal miR-29b and Ca2+ in regulating the function of human lens epithelial cells. Methods: Exosomes were isolated from human aqueous humour by ultracentrifugation, and visualized by nanoparticle tracking and transmission electron microscopy. Exosomal miRNA sequencing was performed to identify differentially expressed miRNAs between diabetes and cataracts group (DMC) and age-related cataracts group (ARC). TargetScan was used to predict potential target of certain miRNA. The expression of CACNA1C mRNA was determined by quantitative real-time PCR and CACNA1C protein was determined by Western blotting. Concentration of Ca2+ in human aqueous humour and the culture supernatant of cells was detected by the Calcium Assay Kit. Cell Counting Kit-8 was used to determine cell viability. Results: Exosomes were isolated from human aqueous humour, which had a typical cup-shaped phenotype and a particle size distribution in accordance with micro extracellular vesicles. Exosomal miRNA sequencing revealed that miR-29b was significantly downregulated in diabetes and cataracts group (DMC) compared with age-related cataracts group (ARC). Ca2+ concentration of human aqueous humour in DMC was higher than that in ARC. The culture supernatant of cells transfected with miR-29b inhibitors had a higher concentration of Ca2+ than that transfected with miR-29b mimics. miR-29b reduced the viability of human lens epithelium cells (HLECs) by upregulating CACNA1C expression.Conclusions: Exosomes isolated from human aqueous humour contained abundant miRNAs. A significantly expressed miRNA, miR-29b, could affect the concentration of Ca2+ and regulate HLEC processes by upregulating CACNA1C.

Exosomal miR-29b found in aqueous humour mediates calcium signaling in diabetic patients with cataract

Background: Ca2+ was supposed to play an important role in the cataract formation. Exosomal miR-29b from aqueous humour may play an important role in the mechanism of diabetes and cataracts. The purpose of this study was to investigate the role of exosomal miR-29b and Ca2+ in regulating the function of human lens epithelial cells. Methods: Exosomes were isolated from human aqueous humour by ultracentrifugation, and visualized by nanoparticle tracking and transmission electron microscopy. Exosomal miRNA sequencing was performed to identify differentially expressed miRNAs between diabetes and cataracts group (DMC) and age-related cataracts group (ARC). TargetScan was used to predict potential target of certain miRNA. The expression of CACNA1C mRNA was determined by quantitative real-time PCR and CACNA1C protein was determined by Western blotting. Concentration of Ca2+ in human aqueous humour and the culture supernatant of cells was detected by the Calcium Assay Kit. Cell Counting Kit-8 was used to determine cell viability. Results: Exosomes were isolated from human aqueous humour, which had a typical cup-shaped phenotype and a particle size distribution in accordance with micro extracellular vesicles. Exosomal miRNA sequencing revealed that miR-29b was significantly downregulated in diabetes and cataracts group (DMC) compared with age-related cataracts group (ARC). Ca2+ concentration of human aqueous humour in DMC was higher than that in ARC. The culture supernatant of cells transfected with miR-29b inhibitors had a higher concentration of Ca2+ than that transfected with miR-29b mimics. miR-29b reduced the viability of human lens epithelium cells (HLECs) by upregulating CACNA1C expression.Conclusions: Exosomes isolated from human aqueous humour contained abundant miRNAs. A significantly expressed miRNA, miR-29b, could affect the concentration of Ca2+ and regulate HLEC processes by upregulating CACNA1C.

Exosomal miR-29b of Aqueous Humour Mediated Variation of Ca2+ in Diabetes and Cataract Patients

Background: Ca2+ was supposed to play an important role in the formation of cataract. Considering our increasing knowledge of exosomes, exosomal miRNAs isolated from aqueous humour may play an important role in the mechanism of diabetes and cataracts. In this study, we aimed to investigate the role of exosomal miR-29b and Ca2+ in regulating the function of human lens epithelial cells. Methods: Exosomes were isolated from human aqueous humour by ultracentrifugation, and visualized by nanoparticle tracking and transmission electron microscopy. Exosomal miRNA sequencing was performed to identify differentially expressed miRNAs between diabetes and cataracts group (DMC) and age-related cataracts group (ARC). TargetScan was used to predict potential target of certain miRNA. The expression of CACNA1C mRNA was determined by quantitative real-time PCR and CACNA1C protein was determined by Western blotting. Concentration of Ca2+ of human aqueous humour and cell culture supernatant was detected by the Calcium Assay Kit. Cell Counting Kit-8 was used to determine cell viability. Results: Exosomes could be isolated from human aqueous humour, which had a typical cup-shaped phenotype and a particle size distribution in accordance with micro extracellular vesicles. Exosomal miRNA sequencing revealed that miR-29b was significantly downregulated in diabetes and cataracts group (DMC) compared with age-related cataracts group (ARC). Ca2+ concentration of human aqueous humour in DMC was higher than that in ARC. Cell culture supernatant transfected with miR-29b inhibitors had a higher concentration of Ca2+ than that transfected with miR-29b mimics. miR-29b reduced the viability of human lens epithelium cells (HLECs) by up-regulating CACNA1C expression.Conclusions: Exosomes isolated from human aqueous humour contained abundant miRNAs. A significantly expressed miRNA, miR-29b, could affect the concentration of Ca2+ and regulate HLEC processes by up-regulating CACNA1C.

Transfection of CTGF siRNA inhibits transdifferentiation in human lens epithelium cell line B3 in vitro

AIM: To investigate the expression of connective tissue growth factor (CTGF) and α-smooth muscle actin (α-SMA) in human lens epithelium cell (HLEC) line B3 after transfection by liposome-coated small interfering RNA (siRNA) targeting CTGF. METHODS: HLECs were transfected with siRNA targeting CTGF, labeled with 5’-fluorescein isothiocyanate (5’-FITC) and coated with lipofectamine. The transfection ratio was evaluated via fluorescence intensity. Cell counting kit-8 (CCK-8) assay was performed to assess cytoviability of both non-transfected and transfected HLECs. Quantitative reverse transcription-polymerase chain reaction (RT-PCR), cell immunochemistry and Western blot analysis were conducted to detect the expression changes of CTGF and α-SMA after transfection. RESULTS: A highly effective transfection ratio was observed in siRNA co-transfected with lipofectamine. The transfection ratio reached 95% at 24h. The proliferation of HLECs was inhibited by siRNA after 72h transfection. The expression of CTGF and α-SMA significantly decreased in HLECs after transfected by CTGF siRNA for 24h. This effect was not found in negative control siRNA. CONCLUSION: siRNA targeting CTGF decrease CTGF and α-SMA expression in HLECs, which is a potential therapeutic strategy for posterior capsular opacification.

Ethylene glycol coated nanoceria protects against oxidative stress in human lens epithelium

Nanoceria (<5 nm), stabilised with ethylene glycol, protects human lens epithelium from oxidative stress and exhibits multicoloured photoluminescence.