Establishment of inducible wild type and mutant myocilin-GFP-expressing RGC5 cell lines

Aloin decelerates the progression of hepatocellular carcinoma through circ_0011385/miR-149-5p/WT1 axis

CircRNA/miRNA/mRNA axis has been reported to play crucial regulatory roles in multiple cancers, including hepatocellular carcinoma (HCC). In addition, recent investigations revealed that aloin exerted anti-tumor functions in HCC. However, the underlying mechanism of aloin on anti-tumor functions in HCC remained elusive. Therefore, this study aimed to investigate whether circRNA/miRNA/mRNA axis medicated the anti-tumor effect of aloin in HCC. Cell viability, invasion, apoptosis and autophagy were accessed by cell counting kit-8 (CCK-8), transwell invasion assay, flow cytometry, Western blot and immunofluorescence analysis, respectively. Expression levels of circ_0011385, miR-149-5p and WT1 mRNA were determined using qRT-PCR assay. Binding sites between miR-149-5p and circ_0011385 or WT1 were predicted in starBase database. The binding relationship among circ_0011385, miR-149-5p and WT1 were verified by dual-luciferase reporter assay and RNA immunoprecipitation. Besides, the rescue experiments were performed by co-transfection with cric_0011385 overexpression plasmid, si-cric_0011385, miR-149-5p mimic and inhibitor, WT1 pDNA and si-WT1 in HCC cells. Furthermore, tumor growth was also investigated in the xenograft mouse model. Aloin inhibited HCC proliferation and invasion as well as promoted apoptosis and autophagy both in vitro and in vivo. Besides, aloin suppressed circ_0011385 expression. Overexpressed circ_0011385 partially reversed the anti-tumor effect of aloin on HCC. In addition, it was revealed that the circ_0011385, miR-149-5p and WT1 genes were abnormally expressed in HCC. Furthermore, the binding interactions between circ_0011385, miR-149-5p and WT1 were predicted and confirmed. Moreover, the effect of circ_0011385 on the anti-tumor role of aloin in HCC was rescued by miR-149-5p mimics. MiR-149-5p regulated HCC progression via modulating WT1. Aloin suppressed cell proliferation, invasion and tumor growth and promoted apoptosis and autophagy in HCC through regulating circ_0011385/miR-149-5p/WT1 axis. Aloin may be a potential candidate drug for HCC treatment.Abbrevations: HCC: Hepatocellular carcinoma; ceRNA: competing endogenous RNA; miRNA: microRNA; MREs: miRNA response elements; WT1: Wilms' tumor 1; MMP-2: Matrix metalloproteinase; EMT: epithelial-mesenchymal transition; GADPH: glyceraldehyde 3-phosphate dehydrogenase; WT: wild type; MUT: mutant type; DMEM: dulbecco's modified eagle medium.

Frontiers of Complex Disease Mechanisms: Membrane Surface Tension May Link Genotype to Phenotype in Glaucoma

Although many monogenic diseases are understood based upon structural changes of gene products, less progress has been made concerning polygenic disease mechanisms. This article presents a new interdisciplinary approach to understand complex diseases, especially their genetic polymorphisms. I focus upon primary open angle glaucoma (POAG). Although elevated intraocular pressure (IOP) and oxidative stress are glaucoma hallmarks, the linkages between these factors and cell death are obscure. Reactive oxygen species (ROS) promote the formation of oxidatively truncated phosphoglycerides (OTP), free fatty acids, lysophosphoglycerides, oxysterols, and other chemical species that promote membrane disruption and decrease membrane surface tension. Several POAG-linked gene polymorphisms identify proteins that manage damaged lipids and/or influence membrane surface tension. POAG-related genes expected to participate in these processes include: ELOVL5, ABCA1, APOE4, GST, CYP46A1, MYOC, and CAV. POAG-related gene products are expected to influence membrane surface tension, strength, and repair. I propose that heightened IOP overcomes retinal ganglion cell (RGC) membrane compressive strength, weakened by damaged lipid accumulation, to form pores. The ensuing structural failure promotes apoptosis and blindness. The linkage between glaucoma genotype and phenotype is mediated by physical events. Force balancing between the IOP and compressive strength regulates pore nucleation; force balancing between pore line tension and membrane surface tension regulates pore growth. Similar events may contribute to traumatic brain injury, Alzheimer's disease, and macular degeneration.

Herpes Simplex Virus-1 Fine-Tunes Host's Autophagic Response to Infection: A Comprehensive Analysis in Productive Infection Models

Herpes simplex virus-1 (HSV-1) infection causes severe conditions, with serious complications, including corneal blindness from uncontrolled ocular infections. An important cellular defense mechanism against HSV-1 infection is autophagy. The autophagic response of the host cell was suggested to be regulated by HSV-1. In this study, we performed a detailed analysis of autophagy in multiple HSV-1-targeted cell types, and under various infection conditions that recapitulate a productive infection model. We found that autophagy was slightly inhibited in one cell type, while in other cell types autophagy maintained its basal levels mostly unchanged during productive infection. This study refines the concept of HSV-1-mediated autophagy regulation to imply either inhibition, or prevention of activation, of the innate immune pathway.

Cellular processing of myocilin

Background

Myocilin (MYOC) is a gene linked directly to juvenile- and adult-onset open angle glaucoma. Mutations including Pro370Leu (P370L) and Gln368stop (Q368X) have been identified in patients. In the present study, we investigated the processing of myocilin in human trabecular meshwork (TM) cells as well as in inducible, stable RGC5 cell lines.

Methodology/Principal Findings

The turnover and photoactivation experiments revealed that the endogenous myocilin in human trabecular meshwork (TM) cells was a short-lived protein. It was found that the endogenous myocilin level in TM cells was increased by treatment of lysosomal and proteasomal inhibitors, but not by autophagic inhibitor. Multiple bands immunoreactive to anti-ubiquitin were seen in the myocilin pull down, indicating that myocilin was ubiquitinated. In inducible cell lines, the turnover rate of overexpressed wild-type and mutant P370L and Q368X myocilin-GFP fusion proteins was much prolonged. The proteasome function was compromised and autophagy was induced. A decreased PSMB5 level and an increased level of autophagic marker, LC3, were demonstrated.

Conclusions/Significance

The current study provided evidence that in normal homeostatic situation, the turnover of endogenous myocilin involves ubiquitin-proteasome and lysosomal pathways. When myocilin was upregulated or mutated, the ubiquitin-proteasome function is compromised and autophagy is induced. Knowledge of the degradation pathways acting on myocilin can help in design of novel therapeutic strategies for myocilin-related glaucoma.