Dataset Information

Mechanistic Effects of Baicalein on Aqueous Humor Drainage and Intraocular Pressure.

ABSTRACT: Elevated intraocular pressure (IOP) is a major risk factor for glaucoma that results from impeded fluid drainage. The increase in outflow resistance is caused by trabecular meshwork (TM) cell dysfunction and excessive extracellular matrix (ECM) deposition. Baicalein (Ba) is a natural flavonoid and has been shown to regulate cell contraction, fluid secretion, and ECM remodeling in various cell types, suggesting the potential significance of regulating outflow resistance and IOP. We demonstrated that Ba significantly lowered the IOP by about 5 mmHg in living mice. Consistent with that, Ba increased the outflow facility by up to 90% in enucleated mouse eyes. The effects of Ba on cell volume regulation and contractility were examined in primary human TM (hTM) cells. We found that Ba (1-100 µM) had no effect on cell volume under iso-osmotic conditions but inhibited the regulatory volume decrease (RVD) by up to 70% under hypotonic challenge. In addition, Ba relaxed hTM cells via reduced myosin light chain (MLC) phosphorylation. Using iTRAQ-based quantitative proteomics, 47 proteins were significantly regulated in hTM cells after a 3-h Ba treatment. Ba significantly increased the expression of cathepsin B by 1.51-fold and downregulated the expression of D-dopachrome decarboxylase and pre-B-cell leukemia transcription factor-interacting protein 1 with a fold-change of 0.58 and 0.40, respectively. We suggest that a Ba-mediated increase in outflow facility is triggered by cell relaxation via MLC phosphorylation along with inhibiting RVD in hTM cells. The Ba-mediated changes in protein expression support the notion of altered ECM homeostasis, potentially contributing to a reduction of outflow resistance and thereby IOP.

SUBMITTER: Li HL

PROVIDER: S-EPMC9266486 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Fundoscopy is the standard method for diagnosis and follow-up of intraocular retinoblastoma, but it is sometimes insufficient to discern whether tumors are inactivated following treatments. In this work, we hypothesized that the amount of conserved nuclear DNA sequences in the cell-free DNA (cfDNA) fraction of the aqueous humor (AH) might complement fundoscopy for retinoblastoma follow-up. To address our hypothesis, we developed highly sensitive droplet digital polymerase chain reaction (ddPCR) methods to quantify highly conserved DNA sequences of nucleus-encoded genes (GAPDH and B4GALNT1) and of a mitochondrial gene, MT-ATP6. We obtained AH samples during intravitreal treatments. We analyzed 42 AH samples from 25 patients with intraocular retinoblastoma and 11 AH from controls (non-cancer patients). According to clinical criteria, we grouped patients as having progression-free or progressive retinoblastoma. cfDNA concentration in the AH was similar in both retinoblastoma groups. Copy counts for nucleus-derived sequences of GAPDH and B4GALNT1 were significantly higher in the AH from patients with progressive disease, compared to the AH from progression-free patients and control non-cancer patients. The presence of mitochondrial DNA in the AH explained that both retinoblastoma groups had similar cfDNA concentration in AH. The optimal cut-off point for discriminating between progressive and progression-free retinoblastomas was 108 GAPDH copies per reaction. Among patients having serial AH samples analyzed during their intravitreal chemotherapy, GAPDH copies were high and decreased below the cut-off point in those patients responding to chemotherapy. In contrast, one non-responder patient remained with values above the cut-off during follow-up, until enucleation. We conclude that the measurement of conserved nuclear gene sequences in AH allows follow-up of intraocular retinoblastoma during intravitreal treatment. The method is applicable to all patients and could be relevant for those in which fundoscopy evaluation is inconclusive.

Dataset Information

Mechanistic Effects of Baicalein on Aqueous Humor Drainage and Intraocular Pressure.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets