Role of transforming growth factor-beta1 and its latent form binding protein in pseudoexfoliation syndrome

Rosemary extract and rosmarinic acid accelerate elastic fiber formation by increasing the expression of elastic fiber components in dermal fibroblasts

Ultraviolet (UV)-induced skin photoaging is caused by qualitative and quantitative degradation of dermal extracellular matrix components such as collagen and elastic fibers. Elastic fibers are important for maintaining cutaneous elasticity, despite their small amount in the skin. Previously, microfibril-associated protein 4 (MFAP-4), which is downregulated in photoaging dermis, has been found to be essential for elastic fiber formation by interaction with both fibrillin-1 and elastin, which are core components of elastic fiber. In addition, enhanced cutaneous MFAP-4 expression in a human skin-xenografted murine photoaging model protects against UV-induced photodamage accompanied by the prevention of elastic fiber degradation and aggravated elasticity. We therefore hypothesized that the upregulation of MFAP-4 in dermal fibroblasts may more efficiently accelerate elastic fiber formation. We screened botanical extracts for MFAP-4 expression-promoting activity in normal human dermal fibroblasts (NHDFs). We found that rosemary extract markedly promotes early microfibril formation and mature elastic fiber formation along with a significant upregulation of not only MFAP-4 but also fibrillin-1 and elastin in NHDFs. Furthermore, rosmarinic acid, which is abundant in rosemary extract, accelerated elastic fiber formation via upregulation of transforming growth factor β-1. This was achieved by the induction of cAMP response element-binding protein phosphorylation, demonstrating that rosmarinic acid represents one of the active ingredients in rosemary extract. Based on the findings in this study, we conclude that rosemary extract and rosmarinic acid represent promising materials that exert a preventive or ameliorative effect on skin photoaging by accelerating elastic fiber formation.

Pseudoexfoliation Syndrome Presenting With Bilateral Visual Impairment and Intraocular Pressure Discrepancy: A Case Report

Pseudoexfoliation syndrome (PEX) presents a significant clinical challenge due to its diverse ocular manifestations, including glaucoma and zonular weakness of the lens, which can lead to irreversible visual impairment if left untreated. We report a case of a 78-year-old male presenting with bilateral visual impairment persisting for four years, with a more pronounced decline in the right eye over the past six months. Examination revealed aphakia with pseudoexfoliative material in the right eye, a cataract with pseudoexfoliative material in the left eye, and a notable intraocular pressure (IOP) discrepancy. Surgical intervention was required for both eyes, with cataract extraction and IOP-lowering procedures performed to preserve vision and prevent further deterioration. This case underscores the importance of timely recognition and comprehensive management of PEX-related ocular complications to optimize visual outcomes and quality of life for affected individuals. Close collaboration between ophthalmologists and other healthcare professionals is essential to address the multifaceted nature of PEX and tailoring treatment strategies to individual patient needs. Further research is needed to elucidate the underlying pathophysiology of PEX and refine therapeutic approaches to mitigate its detrimental effects on vision.

Secondary glaucoma: Toward interventions based on molecular underpinnings

Glaucoma is a heterogeneous group of progressive diseases that leads to irreversible blindness. Secondary glaucoma refers to glaucoma caused by a known underlying condition. Pseudoexfoliation and pigment dispersion syndromes are common causes of secondary glaucoma. Their respective deposits may obstruct the trabecular meshwork, leading to aqueous humor outflow resistance, ocular hypertension, and optic neuropathy. There are no disease-specific interventions available for either. Pseudoexfoliation syndrome is characterized by fibrillar deposits (pseudoexfoliative material) on anterior segment structures. Over a decade of multiomics analyses taken together with the current knowledge on pseudoexfoliative glaucoma warrant a re-think of mechanistic possibilities. We propose that the presence of nucleation centers (e.g., vitamin D binding protein), crosslinking enzymes (e.g., transglutaminase 2), aberrant extracellular matrix, flawed endocytosis, and abnormal aqueous-blood barrier contribute to the formation of proteolytically resistant pseudoexfoliative material. Pigment dispersion syndrome is characterized by abnormal iridolenticular contact that disrupts iris pigment epithelium and liberates melanin granules. Iris melanogenesis is aberrant in this condition. Cytotoxic melanogenesis intermediates leak out of melanosomes and cause iris melanocyte and pigment epithelium cell death. Targeting melanogenesis can likely decrease the risk of pigmentary glaucoma. Skin and melanoma research provides insights into potential therapeutics. We propose that specific prostanoid agonists and fenofibrates may reduce melanogenesis by inhibiting cholesterol internalization and de novo synthesis. Additionally, melatonin is a potent melanogenesis suppressor, antioxidant, and hypotensive agent, rendering it a valuable agent for pigmentary glaucoma. In pseudoexfoliative glaucoma, where environmental insults drive pseudoexfoliative material formation, melatonin's antioxidant and hypotensive properties may offer adjunct therapeutic benefits. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology.

Cardiovascular Manifestations of Pseudoexfoliation Syndrome: A Narrative Review

Pseudoexfoliation syndrome (PEX) is a long-term, age-related extracellular matrix condition that causes aberrant fibrillary pseudoexfoliative material (PXM) to accumulate in various body tissues. The anterior portion of the eye is where this disorder most frequently presents. It affects the entire body. Most frequently, it is seen in older people, usually those over 50. Fibrillar deposits are a symptom of the pseudoexfoliation syndrome and are found in the anterior part of the eye. Deposition of fibrillary white flaky material is seen. The lens capsule, cornea, ciliary epithelium, lens epithelium, iris pigment epithelium, zonules, orbital soft tissues, trabecular meshwork, iris blood vessels, and iris stroma have all been reported to show such depositions. The skin, heart, lungs, liver, kidneys, and other organs have also been reported to contain these deposits. Asymmetrical and bilateral illnesses are both possible. Myocardial infarction, cerebrovascular accidents, and systemic hypertension have all been linked to it. The pseudoexfoliative condition was first reported with the characteristic findings of white or grey flakes on the anterior lens capsule, the prevalence of glaucoma rising with age, and its presence in about 50% of eyes. A few decades later, the term pseudoexfoliation was given to differentiate it from the true exfoliation syndrome. True exfoliation syndrome is characterized by lamellar delamination of the lens capsule and is caused by exposure to infrared radiation. It is commonly seen in glassblowers. Age is a risk factor for PEX once a person reaches 70. Symptoms of PEX include elevated intraocular pressure, peripapillary transillumination deficiencies, potential glaucomatous optic nerve damage, poor dilatation, Sampaolesi line, and fibrillar white flaky deposits along the pupillary border. Meanwhile, fibrillar white flaky deposits on the anterior lens capsule (Hoarfrost Ring) and pigment dispersion syndrome are not pathognomonic.

A Study on the Candidate Gene Association and Interaction with Measures of UV Exposure in Pseudoexfoliation Patients from India

PURPOSE

Environmental and genetic factors are associated with development of Pseudoexfoliation syndrome (XFS). Here we intended to elucidate the association of candidate genes in relevance to UV exposure in these patients.

METHODS

This is a case-control study of 309 subjects (N = 219 controls and 90 XFS cases) from India. PCR based direct sequencing was performed for candidate genes (LOXL1, POMP and TMEM136) followed by genotype and haplotype analysis. The promoter methylation status was assessed by Methylation specific PCR based direct sequencing of genomic DNA for all samples. The methylation status was compared with that of primary fibroblasts cultures established from patient's Tenon's tissue samples in subset of these patients.

RESULTS

SNPs rs3825942, rs41435250, rs8818 (LOXL1) and rs3737528 (POMP) showed significant association with XFS. LOXL1 gene haplotype GAGC (rs1048661- rs3825942- rs41435250-rs8818) was associated with lower risk for XFS with a p value 4.1961 × 10-6 (OR =0; 95%CI, 0.000-0.003). POMP gene haplotypes for intronic SNPs (rs1340815- rs3737528- rs913797) TCC and TTC were associated with increased risk for the disease (OR > 1.0). Significant correlation for SNPs rs3825942 of LOXL1 (ρ= -0.132) and rs3737528 of POMP (ρ = 0.12) was observed with measure of lifetime UV exposure (CUVAF value). Reduced LOXL1 gene expression was observed in cultured tenon fibroblasts from the patients that correlated with differential methylation of the Sp-1 binding sites at -253, -243bp upstream to the transcription start site of LOXL1 promoter region.

CONCLUSION

Our results suggest a possible interaction for LOXL1 gene haplotype (GAGC) with the measure of ocular UV exposure in pseudoexfoliation syndrome.

Evaluation of expression pattern of cellular miRNAs (let-7b, miR-29a, miR-126, miR-34a, miR-181a-5p) and IL-6, TNF-α, and TGF-β in patients with pseudoexfoliation syndrome

Pseudoexfoliation syndrome (PEX) is a critical clinical and biological extracellular matrix systemic disorder. Despite the unknown nature of PEX etiopathogenesis, it is proven to be associated with various genes and factors. The present research focused on analyzing the expression of miR and inflammatory cytokines in PEX. Serum and aqueous humor (AH) were collected prior to cataract surgery or trabeculectomy from 99 participants (64 with PEX glaucoma, and 35 controls). Real-time PCR was used for assessing the expression pattern of some miRNAs namely let-7b, miR-29a, miR-126, miR-34a, and miR-181a-5p. ELISA was carried out to explore the transcription of some inflammatory cytokines such as TGF-β, TNF-α, and IL-6. The indication of our results was a significant enhancement in the expression of let-7, miR-34a, and miR-181a-5p in PEX in contrast to the control group. Notwithstanding a significant suppression in miR-29a, and miR-126 expression levels in PEX in contrast to the control group. Analysis of ROC curve revealed that miR-29a and miR-34a are able to act as useful markers in order to discriminate the PEX group from the PEX negative subjects which were determined as the control group. According to the results obtained, the mean levels of TGF-β, TNF-α, and IL-6 upregulated among PEX subjects in contrast to control samples. In conclusion, our findings indicated that the selected cytokines alongside the selected miRNAs could be introduced as a biomarker panel in the diagnosis of PEX.

New Biomarker Combination Related to Oxidative Stress and Inflammation in Primary Open-Angle Glaucoma

Glaucoma is a multifactorial neurodegenerative disease and the second leading cause of blindness. Detection of clinically relevant biomarkers would aid better diagnoses and monitoring during treatment. In glaucoma, the protein composition of aqueous humor (AH) is relevant for the discovery of biomarkers. This study analyzes AH protein concentrations of putative biomarkers in patients with primary open-angle glaucoma (POAG) compared to a control group. Biomarkers were selected from known oxidative-stress and inflammatory pathways. Osteopontin (OPN), matrix metalloproteinase 9 (MMP-9), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta), and interleukin-10 (IL-10) were measured using the ELISA technique. Thirty-two patients were recruited to the study, including sixteen control and sixteen glaucoma patients. The glaucoma group consisted of patients diagnosed with glaucoma. In both groups, the aqueous humor sample was obtained during cataract surgery. A significant increase in OPN, MMP-9, TNF-alpha, and IL-10 was observed in the POAG aqueous humor, compared to the control group (p < 0.05). Of note, the AH of POAG patients contained 5.6 ± 1.2-fold more OPN compared to that of control patients. Different expression profiles of oxidative stress-related and inflammatory biomarkers were observed between patients with POAG and controls. This confirms the reported involvement of inflammatory and oxidative stress pathways in POAG pathophysiology. In the future, several, targeted AH proteins may be used to generate a potential biomarker expression profile of this disease, aiding diagnoses and disease progression monitoring. This approach highlights the importance of biomarkers in the future. Biomarkers provide a way to measure disease progression and response to treatment. In the future, biomarkers will play a more critical role in the toolkit of ophthalmology healthcare professionals as the field moves towards personalized medicine and precision healthcare.

CCN2/CTGF tip the balance of growth factors towards TGF-β2 in primary open-angle glaucoma

TGF-β2 is the predominant TGF-β isoform within the eye. One function of TGF-β2 is to provide the eye with immune protection against intraocular inflammation. The beneficial function of TGF-β2 within the eye must be under tight control of a network of different factors. A disbalance of the network can result in different eye diseases. In Primary Open-Angle Glaucoma (POAG), one of the leading causes of irreversible blindness worldwide, TGF-β2 is significantly elevated in the aqueous humor and antagonistic molecules like BMPs are reduced. The changes provoke an altering of the quantity and quality of the extracellular matrix and the actin cytoskeleton in the outflow tissues, leading to an increased outflow resistance and thereby to an increased intraocular pressure (IOP), the major risk factor for primary open-angle glaucoma. The pathologic effect of TGF-β2 in primary open-angle glaucoma is mainly meditated by CCN2/CTGF. CCN2/CTGF can modulate TGF-β and BMP signaling by direct binding. The eye specific overexpression of CCN2/CTGF caused an increase in IOP and led to a loss of axons, the hallmark of primary open-angle glaucoma. CCN2/CTGF appears to play a critical role in the homeostatic balance of the eye, so we investigated if CCN2/CTGF can modulate BMP and TGF-β signaling pathways in the outflow tissues. To this end, we analyzed the direct effect of CCN2/CTGF on both signaling pathways in two transgenic mouse models with a moderate (βB1-CTGF1) and a high CCN2/CTGF (βB1-CTGF6) overexpression and in immortalized human trabecular meshwork (HTM) cells. Additionally, we investigate whether CCN2/CTGF mediates TGF-β effects via different pathways. We observed developmental malformations in the ciliary body in βB1-CTGF6 caused by an inhibition of the BMP signaling pathway. In βB1-CTGF1, we detected a dysregulation of the BMP and TGF-β signaling pathways, with reduced BMP activity and increased TGF-β signaling. A direct CCN2/CTGF effect on BMP and TGF-β signaling was shown in immortalized HTM cells. Finally, CCN2/CTGF mediated its effects on TGF-β via the RhoA/ROCK and ERK signaling in immortalized HTM cells. We conclude that CCN2/CTGF functions as a modulator of the homeostatic balance of BMP and TGF-β signaling pathways, which is shifted in primary open-angle glaucoma.

TGF-β-3 Induces Different Effects from TGF-β-1 and -2 on Cellular Metabolism and the Spatial Properties of the Human Trabecular Meshwork Cells

To compare the effects among three TGF-β isoforms (TGF-β-1, TGF-β-2, and TGF-β-3) on the human trabecular meshwork (HTM), two-dimensional (2D) and three-dimensional (3D) cultures of commercially available certified immortalized HTM cells were used, and the following analyses were conducted: (1) trans-endothelial electrical resistance (TEER) and FITC dextran permeability measurements (2D); (2) a real-time cellular metabolic analysis (2D); (3) analysis of the physical property of the 3D HTM spheroids; and (4) an assessment of the gene expression levels of extracellular matrix (ECM) components (2D and 3D). All three TGF-β isoforms induced a significant increase in TEER values and a relative decrease in FITC dextran permeability in the 2D-cultured HTM cells, but these effects were the most potent in the case of TGF-β-3. The findings indicated that solutions containing 10 ng/mL of TGF-β-1, 5 ng/mL of TGF-β-2, and 1 ng/mL of TGF-β-3 had nearly comparable effects on TEER measurements. However, a real-time cellular metabolic analysis of the 2D-cultured HTM cells under these concentrations revealed that TGF-3-β induced quite different effects on the metabolic phenotype, with a decreased ATP-linked respiration, increased proton leakage, and decreased glycolytic capacity compared with TGF-β-1 and TGF-β-2. In addition, the concentrations of the three TGF-β isoforms also caused diverse effects on the physical properties of 3D HTM spheroids and the mRNA expression of ECMs and their modulators, in many of which, the effects of TGF-β-3 were markedly different from TGF-β-1 and TGF-β-2. The findings presented herein suggest that these diverse efficacies among the TGF-β isoforms, especially the unique action of TGF-β-3 toward HTM, may induce different effects within the pathogenesis of glaucoma.

Genome-Wide RNA Sequencing of Human Trabecular Meshwork Cells Treated with TGF-β1: Relevance to Pseudoexfoliation Glaucoma

Pseudoexfoliation glaucoma (XFG) is an aggressive form of secondary open angle glaucoma, characterised by the production of exfoliation material and is estimated to affect 30 million people worldwide. Activation of the TGF-β pathway by TGF-β1 has been implicated in the pathogenesis of pseudoexfoliation glaucoma. To further investigate the role of TGF-β1 in glaucomatous changes in the trabecular meshwork (TM), we used RNA-Seq to determine TGF-β1 induced changes in the transcriptome of normal human trabecular meshwork (HTM) cells. The main purpose of this study was to perform a hypothesis-independent RNA sequencing analysis to investigate genome-wide alterations in the transcriptome of normal HTMs stimulated with TGF-β1 and investigate possible pathophysiological mechanisms driving XFG. Our results identified multiple differentially expressed genes including several genes known to be present in exfoliation material. Significantly altered pathways, biological processes and molecular functions included extracellular matrix remodelling, Hippo and Wnt pathways, the unfolded protein response, oxidative stress, and the antioxidant system. This cellular model of pseudoexfoliation glaucoma can provide insight into disease pathogenesis and support the development of novel therapeutic interventions.

TGF-β-Mediated Modulation of Cell-Cell Interactions in Postconfluent Maturing Corneal Endothelial Cells

Purpose

Transforming growth factor-beta (TGF-β) is known to influence many cell functions. In the corneal endothelium, TGF-β1 exerts contextual effects, promoting endothelial–mesenchymal transition in proliferating cells and enhancing barrier integrity in early confluent maturing cells. Herein, we studied how TGF-β isoforms participate in the formation of corneal endothelial intercellular junctions.

Methods

Corneal endothelial cells (CECs) were cultured using a two-phase media approach. When CECs reached confluence, the proliferation medium was replaced with maturation medium, which was supplemented or not with TGF-β isoforms. The cell morphology (circularity index), intercellular junction protein expression, trans-endothelial electrical resistance (TEER), and permeability of 7-day postconfluent CECs were assessed. Gene transcription and signaling pathways that were activated following maturation in the presence of TGF-β2 were also studied. The beneficial effect of TGF-β2 on CEC maturation was evaluated using ex vivo corneas mounted on a corneal bioreactor.

Results

The results showed increases in circularity index, membrane localization of junction-related proteins, and TEER when TGF-β isoforms were individually added during the maturation phase, and TGF-β2 was the most effective isoform. Gene profiling revealed an increase in extracellular matrix-related gene expression. In ex vivo cell adhesion experiments, CECs that were matured in the presence of TGF-β2 had a higher circularity index and cell density and exhibited cell membrane-localized junction-related protein expression at earlier time points.

Conclusions

These results suggest that TGF-β2 can strengthen cell–cell and cell–substrate adhesion, which accelerates barrier integrity establishment and thus enhances CEC functionality.

Fibrotic Response of Human Trabecular Meshwork Cells to Transforming Growth Factor-Beta 3 and Autotaxin in Aqueous Humor

This study examines the potential role of transforming growth factor-beta 3 (TGF-β3) on the fibrotic response of cultured human trabecular meshwork (HTM) cells. The relationships and trans-signaling interactions between TGF-β3 and autotaxin (ATX) in HTM cells were also examined. The levels of TGF-β and ATX in the aqueous humor (AH) of patients were measured by an immunoenzymetric assay. The TGF-β3-induced expression of the fibrogenic markers, fibronectin, collagen type I alpha 1 chain, and alpha-smooth muscle actin, and ATX were examined by quantitative real-time PCR, Western blotting, and immunocytochemistry, and the trans-signaling regulatory effect of TGF-β3 on ATX expression was also evaluated. In HTM cells, the significant upregulation of ATX was induced by TGF-β3 at a concentration of 0.1 ng/mL, corresponding to the physiological concentration in the AH of patients with exfoliative glaucoma (XFG). However, higher concentrations of TGF-β3 significantly suppressed ATX expression. TGF-β3 regulated ATX transcription and signaling in HTM cells, inducing the upregulation of fibrogenic proteins in a dose-dependent manner. Trans-signaling of TGF-β3 regulated ATX transcription, protein expression, and signaling, and was thereby suggested to induce fibrosis of the trabecular meshwork. Modulation of trans-signaling between TGF-β3 and ATX may be key to elucidate the pathology of XFG, and for the development of novel treatment modalities.

Risk factors for early-onset exfoliation syndrome

Although exfoliation syndrome (XFS) is an age-related, late-onset disease, early-onset XFS has been reported, and its associated factors remain unknown. In this study, we investigated the clinical features and risk factors of early-onset XFS. The participants were divided into two groups according to age at the time of XFS diagnosis: early-onset (< 60 years) or late-onset (≥ 70 years) group. Among the 302 eyes of 240 patients with XFS, the early-onset group included 41 eyes (14%) of 33 patients, and the late-onset group included 163 eyes (54%) of 126 patients; the mean age was 54.8 ± 5.0 and 76.6 ± 4.9 years, respectively (p < 0.001). All eight cases diagnosed with XFS at the earliest age, ranging from 36 to 52 years, underwent trabeculectomy before the diagnosis of XFS. Multivariable logistic regression analysis showed that a history of trabeculectomy (odds ratio [OR] = 11.435, p < 0.001), presence of iridectomy (OR = 11.113, p < 0.001), and longer axial length (OR = 2.311, p = 0.003) were significantly associated with the development of early-onset XFS. Collectively, patients with early-onset XFS were more likely to have undergone trabeculectomy and have more axial myopia compared with those with late-onset XFS. These findings suggest that surgical trauma compromising the blood-aqueous barrier may trigger early manifestation of XFS.

The Effect of Amniotic Membrane Transplantation on Trabeculectomy in Patients with Pseudoexfoliation Glaucoma

Purpose

The aim is to evaluate the effect of amniotic membrane transplantation (AMT) on trabeculectomy with mitomycin C in patients with pseudoexfoliation glaucoma (PXG).

Methods

This retrospective cohort study included 85 eyes of PXG who underwent trabeculectomy with or without AMT (52/33 eyes in the AMT/control group). Surgical success was defined by these criteria: (1) intraocular pressure (IOP) ≤18 mmHg and IOP reduction ≥20% and (2) IOP ≤15 mmHg and IOP reduction ≥25%. Criteria A and B defined complete success rates as patients who met these criteria without medication, respectively. Criteria C and D defined qualified success rates as patients who met these criteria with medication, respectively. Cumulative probabilities of success were compared using the Kaplan–Meier survival analysis. Cox proportional hazard models were used to evaluate the influence of AMT on surgical success accounting for confounding variables.

Results

For the AMT group, compared with the control group, the complete success rates at 12 months for criterion A were 86.5% and 63.6%, respectively (P = 0.017) and for criterion B, 86.4% and 63.6% (P = 0.005). The qualified success rates at 12 months for criterion C were 92.1% and 75.1%, respectively (P = 0.047) and for criterion D, 92.1% and 72.1% (P = 0.021). On multivariable Cox regression analyses, AMT was associated with a lower failure rate on criteria A, B, and D (all P ≤ 0.047). Incidence of avascular bleb was higher in the control group than in the AMT group (7 vs 0 eyes; P = 0.004).

Conclusions

In patients with PXG, trabeculectomy with AMT was associated with higher success rates and a lower incidence of avascular bleb compared with conventional trabeculectomy. Research Registration. This retrospective cohort study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr/cris/index/index.do, KCT0007228).

Emerging roles of oxidative stress in the pathogenesis of pseudoexfoliation syndrome (Review)

Pseudoexfoliation syndrome (PEXS) is a systemic disease caused by defects in the extracellular matrix (ECM) remodelling process leading to the chronic deposition of extracellular, fibrillary, white flaky pseudoexfoliation material (PEXM) throughout the body. Specifically, PEXM deposits on the lens capsule cause open-angle glaucoma, cataracts and blindness in patients with PEXS. Several gene single nucleotide polymorphisms are linked to the development of PEXS in humans, including lysyl oxidase-like 1 gene, clusterin and fibulin-5. The exact reason for the PEXM generation and its resulting pathogenesis is not well understood. However, defective ECM remodelling and oxidative stress (OS) have been hypothesized as significant events leading to the PEXM. Specifically, the link between OS and PEXS has been well studied, although the investigation is still ongoing. The present review explored recent advances in various aspects of PEXS and the involvement of OS in the eye for PEXS development.

Risk of atrial fibrillation is increased in patients with exfoliation syndrome: the Utah project on exfoliation syndrome (UPEXS)

PURPOSE

Exfoliation syndrome, a systemic disorder with ocular manifestations, is associated with lysyl oxidase-like gene variants. Along with transforming growth factor beta-1, lysyl oxidase-like 1 is a key enzyme in stabilizing extracellular matrix and remodelling collagen/elastin. Given the role that transforming growth factor beta-1, lysyl oxidase-like gene variants and fibrosis play in atrial fibrillation, an association with exfoliation syndrome was investigated.

METHODS

An exfoliation syndrome cohort of 2803 patients and an atrial fibrillation cohort of 43 694 patients aged 60-90 years at disease onset were identified using the Utah Population Database (1996-2015). Conditional logistic regression was used to estimate risk of atrial fibrillation in exfoliation syndrome patients and risk of exfoliation syndrome in atrial fibrillation patients compared with respective 5:1 sex- and age-matched control cohorts. Kaplan-Meier curves were examined to assess survival in atrial fibrillation patients by exfoliation syndrome status.

RESULTS

Exfoliation syndrome patients had a 21% greater risk (95% CI 1.06-1.37; p < 0.0001) of atrial fibrillation. This was more pronounced in exfoliation syndrome patients with no hypertension history, who exhibited a 52% increased atrial fibrillation risk (95% CI 1.27-1.82; p < 0.0001). Atrial fibrillation patients exhibited a 20% increased risk of exfoliation syndrome (95% CI 1.07-1.35; p = 0.003), while atrial fibrillation patients with no hypertension had a 72% higher exfoliation risk (95% CI 1.45-2.03; p < 0.0001). Atrial fibrillation patients with exfoliation syndrome had a higher estimated probability of survival (alive at study end or at last follow-up) compared with patients with no exfoliation history (p < 0.0001, log-rank test).

CONCLUSIONS

Exfoliation syndrome patients were at a statistically significant increased risk of atrial fibrillation. Similarly, atrial fibrillation patients were at a statistically significant higher risk of exfoliation, particularly when hypertension history was absent.

MicroRNA profiles in aqueous humor between pseudoexfoliation glaucoma and normal tension glaucoma patients in a Korean population

We aimed to obtain microRNA (miRNA) profiles of patients with pseudoexfoliation (PEX) glaucoma or normal-tension glaucoma (NTG) compared to normal controls using individual aqueous humor (AH) samples and investigate the role of miRNAs in the pathogenesis of PEX glaucoma compared to NTG in Korean. AH (80-120 µl) was collected before cataract surgery or trabeculectomy from 26 Korean subjects (eleven with PEX glaucoma, age-matched eight NTG, and seven controls). RNA sequencing was conducted for RNA samples extracted from 26 AH samples. Bioinformatics analysis was performed for targets and related pathways. A total of 334 and 291 discrete miRNAs were detected in AH samples of PEX glaucoma and NTG patients, respectively. Two significantly upregulated miRNAs (hsa-miR-30d-5p and hsa-miR-320a) and ten significantly downregulated miRNAs (hsa-miR-3156-5p, hsa-miR-4458, hsa-miR-6717-5p, hsa-miR-6728-5p, hsa-miR-6834-5p, hsa-miR-6864-5p, hsa-miR-6879-5p, hsa-miR-877-3p, hsa-miR-548e-3p, and hsa-miR-6777-5p) in PEX glaucoma patients compared to control (fold-change > 2, p < 0.05) were found. In NTG patients, ten significantly upregulated and two downregulated miRNAs compared to control were found. Only hsa-miR-6777-5p was commonly downregulated in both PEX glaucoma and NTG patients. Related pathways were proteoglycans in cancer, glioma, and TGF-beta signaling pathway in PEX glaucoma. These differentially expressed miRNAs between PEX glaucoma and NTG samples suggest the possible role of miRNA in the pathogenesis of glaucoma, further implying that pathogenic mechanisms may differ between different types of glaucoma.

RNA Sequencing of Lens Capsular Epithelium Implicates Novel Pathways in Pseudoexfoliation Syndrome

Purpose

Pseudoexfoliation syndrome (PEX) is a common systemic disease that results in severe and often irreversible vision loss. Despite considerable research effort, PEX remains incompletely understood. This study sought to perform the first RNAseq study in elucidate the pathophysiology of PEX, and contribute a publicly available transcriptomic data resource for future research.

Methods

Human ocular lens capsular epithelium samples were collected from 25 patients with PEX and 39 non-PEX controls undergoing cataract surgery. RNA extracted from these specimens was subjected to polyadenylated (mRNA) selection and deep bulk RNA sequencing. Differential expression analysis investigated protein-coding gene transcripts. Exploratory analyses used pathway analysis tools, and curated class- and disease-specific gene sets.

Results

Differential expression analysis demonstrated that 2882 genes were differentially expressed according to PEX status. Genes associated with viral gene expression pathways were among the most upregulated, alongside genes encoding ribosomal and mitochondrial respiratory transport chain proteins. Cell adhesion protein transcripts including type 4 collagen subunits were downregulated.

Conclusions

This comparative transcriptomic dataset highlights novel and previously recognized pathogenic pathways in PEX and provides the first comprehensive transcriptomic resource, adding an additional layer to build further understanding of PEX pathophysiology.

Pseudoexfoliation syndrome: The critical role of the extracellular matrix in pathogenesis and treatment

Pseudoexfoliation syndrome (PEXS) is an age-related condition manifesting mainly in ocular tissues. PEXS is manifested through excess aggregation of fibrillary extracellular material at the anterior part of the eye that consists of a plethora of biomolecules, such as different proteoglycans (PGs) and glycosaminoglycans. PEXS is often linked to increased intraocular pressure, and can also lead to pseudoexfoliation glaucoma with very poor prognosis. Various stimuli are known to affect PEXS, including oxidation stress (OS), UV radiation and osmotic pressure. OS, is prominently involved on the progression of the syndrome as it promotes fibrogenesis, possibly via the induction of transforming growth factor-β (TGF-β) and other biomolecular effectors. In addition, PEXS initiation is tightly connected with the dysregulation of extracellular matrix (ECM) homeostasis since aberrant expression of ECM molecules is linked to both the accumulation and low degradation of pseudoexfoliation material. This article aims at uncovering the crucial role of various ECM effectors such as lysyl oxidase-like proteins, matrix metalloproteinases, and TGF-β1, as well as the biochemical pathways involved in the development and the progression of the PEXS.

Comparison of long-term results of trabeculectomy and phacotrabeculectomy in patients with pseudoexfoliation glaucoma and primary open-angle glaucoma: a single-center study

PURPOSE

To evaluate long-term surgical success and complications in pseudoexfoliation glaucoma (PEXG) and primary open-angle glaucoma (POAG) after trabeculectomy or phacotrabeculectomy.

METHODS

96 PEXG eyes and 114 POAG eyes who underwent primary trabeculectomy and phacotrabeculectomy were retrospectively evaluated considering intraocular pressure (IOP), the number of glaucoma medications, surgical success, and rate of complications. Two success criteria were used: Complete success comprised IOP of 5-18 mmHg and 20% reduction of baseline IOP without medication. Qualified success comprised IOP of 5-18 mmHg and 20% reduction of baseline IOP irrespective of medication. Success rates in PEXG and POAG groups, trabeculectomy and phacotrabeculectomy groups, and four groups divided according to surgery and etiology were analyzed via Kaplan-Meier survival analysis.

RESULTS

The complete and qualified success were not different between PEXG and POAG groups. The qualified success curves show a similar pattern among the four groups throughout the follow-up of 1,2,3,5,7 and 9 years. Baseline IOP and the number of medications were similar in all four groups (p = 0.275 and p = 0.209, respectively). IOP levels and the number of medications were not statistically different between the four groups during the follow-up of 2,5 and 7 years. The total number of complications and interventions were similar between PEXG and POAG groups (p = 0.258).

CONCLUSIONS

Phacotrabeculectomy is an effective procedure as trabeculectomy with similar surgical success rates and few surgical complications when it comes to treating PAOG and PEXG patients. Both approaches resulted in similar postoperative IOP levels and medication numbers in both groups.

Pathogenesis of glaucoma: Extracellular matrix dysfunction in the trabecular meshwork-A review

The trabecular meshwork regulates aqueous humour outflow from the anterior chamber of the eye. It does this by establishing a tunable outflow resistance, defined by the interplay between cells and their extracellular matrix (ECM) milieu, and the molecular interactions between ECM proteins. During normal tissue homeostasis, the ECM is remodelled and trabecular cell behaviour is modified, permitting increased aqueous fluid outflow to maintain intraocular pressure (IOP) within a relatively narrow physiological pressure. Dysfunction in the normal homeostatic process leads to increased outflow resistance and elevated IOP, which is a primary risk factor for glaucoma. This review delineates some of the changes in the ECM that lead to gross as well as some more subtle changes in the structure and function of the ECM, and their impact on trabecular cell behaviour. These changes are discussed in the context of outflow resistance and glaucoma.

A global genetic epidemiological review of pseudoexfoliation syndrome

Pseudoexfoliation (PXF) syndrome is an important public health concern requiring individual population level analysis. Disease prevalence differs by geographic location and ethnicity, and has environmental, demographic, genetic, and molecular risk factors have been demonstrated. Epidemiological factors that have been associated with PXF include age, sex, environmental factors, and diet. Genetic and molecular components have also been identified that are associated with PXF. Underserved populations are often understudied within scientific research, including research about eye disease such as PXF, contributing to the persistence of health disparities within these populations. In each population, PXF needs may be different, and by having research that identifies individual population needs about PXF, the resources in that population can be more efficiently utilized. Otherwise, PXF intervention and care management based only on the broadest level of understanding may continue to exacerbate health disparities in populations disproportionally burdened by PXF.

Primary Human Trabecular Meshwork Model for Pseudoexfoliation

The lack of an animal model or an in vitro model limits experimental options for studying temporal molecular events in pseudoexfoliation syndrome (PXF), an age related fibrillopathy causing trabecular meshwork damage and glaucoma. Our goal was to create a workable in vitro model of PXF using primary human TM (HTM) cell lines simulating human disease. Primary HTM cells harvested from healthy donors (n = 3), were exposed to various concentrations (5 ng/mL, 10 ng/mL, 15 ng/mL) of transforming growth factor-beta1 (TGF-β1) for different time points. Morphological change of epithelial–mesenchymal transition (EMT) was analyzed by direct microscopic visualization and immunoblotting for EMT markers. Expression of pro-fibrotic markers were analyzed by quantitative RT-PCR and immunoblotting. Cell viability and death in treated cells was analyzed using FACS and MTT assay. Protein complex and amyloid aggregate formation was analyzed by Immunofluorescence of oligomer11 and amyloid beta fibrils. Effect of these changes with pharmacological inhibitors of canonical and non-canonical TGF pathway was done to analyze the pathway involved. The expression of pro-fibrotic markers was markedly upregulated at 10 ng/mL of TGF-β1 exposure at 48–72 h of exposure with associated EMT changes at the same time point. Protein aggregates were seen maximally at these time points that were found to be localized around the nucleus and in the extracellular matrix (ECM). EMT and pro-fibrotic expression was differentially regulated by different canonical and non-canonical pathways suggesting complex regulatory mechanisms. This in vitro model using HTM cells simulated the main characteristics of human disease in PXF like pro-fibrotic gene expression, EMT, and aggregate formation.

Cytokine and Growth Factor Analysis in Exfoliation Syndrome and Glaucoma

Purpose

We compared cytokines, chemokines, and growth factors in the aqueous humor (AH) of patients with exfoliation syndrome (XFS), with exfoliation glaucoma (XFG), with primary open angle glaucoma (POAG), and healthy controls.

Methods

AH samples were collected from 21 patients with XFS, 28 with XFG, 14 with POAG, and 17 healthy controls during routine cataract surgery. The protein levels of 21 cytokines and growth factors, together with TGF-β1, 2, and 3, were quantified using the multiplex immunoassay. The levels of each protein in the four groups were compared using the Kruskal-Wallis test.

Results

Among the 24 cytokines and growth factors, 16 were out of the detectable range in >50% of samples in at least one group; the remaining 8 cytokines and growth factors (IL-8, MIP-1α, fractalkine, Flt3 ligand, PDGF-AA, VEGF, TGF-β1, and TGF-β2) were included in the analysis. TGF-β1 and TGF-β2 levels were the highest in patients with XFG and those with POAG, respectively. Expression levels of the inflammatory chemokines IL-8, MIP-1α, and fractalkine, as well as levels of the immune cell growth factor Flt3 ligand, were significantly higher in the XFG group than in the other groups. The protein levels of PDGF-AA and VEGF were not significantly different among the 4 groups.

Conclusions

Both TGF-β1 and inflammatory cytokines were highly expressed in the AH of patients with XFG. Considering that the levels of these cytokines are increased by oxidative stress and that they regulate the extracellular matrix, they may also play a role in intraocular pressure elevation in XFG.

Descemet's membrane injury and regeneration, and posterior corneal fibrosis, in rabbits

The purpose of this investigation was to study Descemet's membrane and corneal endothelial regeneration, myofibroblast generation and disappearance, and TGF beta-1 localization after Descemet's membrane-endothelial excision (Descemetorhexis) in rabbits. Thirty-six rabbits had 8 mm Descemetorhexis and standardized slit lamp photos at 1, 2 and 4 days, 1, 2 and 4 weeks, and 2, 4 and 6 months, as well as multiplex IHC for stromal cell markers keratocan, vimentin, and alpha-smooth muscle actin (SMA); basement membrane (BM) components perlecan, nidogen-1, laminin alpha-5, and collagen type IV; and corneal endothelial marker Na,K-ATPase β1, and TGF beta-1, with ImageJ quantitation. Stromal transparency increased from the periphery beginning at two months after injury and progressed into the central cornea by six months. At six months, central transparency was primarily limited by persistent mid-stromal neovascularization. Stromal myofibroblast zone thickness in the posterior stroma peaked at one month after injury, and then progressively decreased until to six months when few myofibroblasts remained. The regeneration of a laminin alpha-5 and nidogen-1 Descemet's membrane "railroad track" structure was accompanied by corneal endothelial closure and stromal cell production of BM components in corneas from four to six months after injury. TGF beta-1 deposition at the posterior corneal surface from the aqueous humor peaked at one day after Descemetorhexis and diminished even before regeneration of the endothelium and Descemet's membrane. This decrease was associated with collagen type IV protein production by corneal fibroblasts, and possibly myofibroblasts, in the posterior stroma. Descemet's membrane and the corneal endothelium regenerated in the rabbit cornea by six months after eight mm Descemetorhexis. Real-time quantitative RT-PCR experiments in vitro with marker-verified rabbit corneal cells found that 5 ng/ml or 10 ng/ml TGF beta-1 upregulated col4a1 or col4a2 mRNA expression after 6 h or 12 h of exposure in corneal fibroblasts, but not in myofibroblasts. Stromal cells produced large amounts of collagen type IV that likely decreased TGF beta-1 penetration into the stroma and facilitated the resolution of myofibroblast-generated fibrosis.

Inhibitory and Agonistic Autoantibodies Directed Against the β2-Adrenergic Receptor in Pseudoexfoliation Syndrome and Glaucoma

Pseudoexfoliation syndrome (PEXS) and glaucoma (PEXG) are assumed to be caused by a generalized elastosis leading to the accumulation of PEX material in ocular as well as in extraocular tissues. The exact pathophysiology of PEXS is still elusive. PEXG, the most common type of secondary open-angle glaucoma (OAG), is characterized by large peaks of intraocular pressure (IOP) with a progressive loss of the visual field. Agonistic autoantibodies (agAAbs) against the β₂-adrenergic receptor (AR) have been shown to be present in sera of patients with primary and secondary OAG and ocular hypertension and are seemingly linked to IOP. In the present study, we investigated the autoantibodies directed against the β₂-AR in sera of patients with PEXS and PEXG. We recruited 15, 10, and 15 patients with PEXG, PEXS, and primary OAG, respectively. Ten healthy individuals served as controls. All patients underwent standard ophthalmological examination with Octopus G1 perimetry. agAAbs prepared from serum samples were analyzed in a rat cardiomyocyte-based bioassay for the presence of agAAbs. We identified the interacting loop of the β₂-AR and the immunoglobulin G (IgG) subclasses using synthetic peptides corresponding to the extracellular loops of the receptors and enzyme-linked immunosorbent assay, respectively. None of the controls were β₂-agAAb-positive (0.2 ± 0.5 U). No β₂-agAAbs (0.2 ± 0.4 U), but inhibitory β₂-AAbs were observed in 80% of the patients that partially blocked the drug-induced β₂-adrenergic stimulation; 5.8 ± 1.7 U vs. 11.1 ± 0.9 U for clenbuterol in the absence and the presence of sera from patients with PEXS, respectively. Epitope analyses identified the third extracellular loop of the β₂-AR as the target of the inhibitory β₂-AAbs, being of IgG3 subtype in PEXS patients. In contrast, patients with PEXG showed β₂-agAAbs (5.6 ± 0.9 U), but no inhibitory ones. The β₂-agAAbs levels of patients with PEXG and primary OAG patients (3.9 ± 2.8 U; p > 0.05) were at a similar level. In two cases of PEXG, the β₂-agAAbs exert synergistic effects with clenbuterol. The activity increased from 11.5 ± 0.3 (clenbuterol only) to 16.3 ± 0.9 U. As autoimmune mechanisms were reportedly involved in the pathogenesis of glaucoma, agonistic and inhibitory β₂-AAbs seem to be a part of this multifactorial interplay.

Crosstalk between transforming growth factor β-2 and Autotaxin in trabecular meshwork and different subtypes of glaucoma

BACKGROUND

Elevated transforming growth factor (TGF)-β2 in aqueous humor (AH) has been suggested to contribute to trabecular meshwork (TM) fibrosis and intraocular pressure (IOP) regulation in primary open-angle glaucoma (POAG), but TGF-β2 is downregulated in secondary open-angle glaucoma (SOAG). Because autotaxin (ATX) is upregulated in SOAG, we investigated the relationships and trans-signaling interactions of these mediators.

METHODS

The level of ATX in AH was determined using a two-site immunoenzymetric assay, and TGF-β levels were measured using the Bio-Plex Pro TGF-β Assay. RNA scope was used to assess the expression of ATX and TGF-β2 in human's eye specimen. And in vitro studies were performed using hTM cells to explore if trans-signaling of TGF-β2 regulates ATX expressions.

RESULTS

TGF-β2/ATX ratio was significantly high in AH of control or POAG compared with SOAG, and negatively correlated with IOP. RNA scope revelated positive expressions of both TGF-β2 and ATX in ciliary body (CB) and TM in control, but ATX expressions was significantly enhanced in SOAG. In hTM cells, ATX expressions were regulated by TGF-β2 with concentration-dependent manner. In counter, ATX also induced TGF-β1, TGF-β2 and TGFBI upregulations and activation of the Smad-sensitive promoter, as well as upregulation of fibrotic markers, and these upregulation was significantly suppressed by both TGF-β and ATX inhibition.

CONCLUSIONS

Trans-signaling of TGF-β2 regulates ATX expressions and thereby induced upregulations of TGF-βs or fibrosis of hTM. TGF-β2 trans-signaling potently regulate ATX transcription and signaling in hTM cells, which may reflect different profile of these mediators in glaucoma subtypes. Trial Registration This prospective observational study was approved by the Institutional Review Board of the University of Tokyo and was registered with the University Hospital Medical Information Network Clinical Trials Registry of Japan (ID: UMIN000027137). All study procedures conformed to the Declaration of Helsinki. Written informed consent was obtained from each patient.

Long Noncoding RNA LINC01518 Modulates Proliferation and Migration in TGF-β1-Treated Human Tenon Capsule Fibroblast Cells Through the Regulation of hsa-miR-216b-5p

In this study, we investigated the expression and functions of long noncoding RNAs (LncRNAs) of LINC01518 in an in vitro model of TGF-β1-treated human Tenon capsule fibroblast (HTF) cells. qRT-PCR was used to examine LINC01518 expression in in situ human glaucoma tissues, and in vitro HTF cells treated with TGF-β1. Lentivirus-mediated LINC01518 knockdown was performed in HTF cells to investigate its effect on TGF-β1-induced cell proliferation, migration and autophagy signaling pathway. The potential ceRNA candidate of LINC01518, hsa-miR-216b-5p, was probed by dual-luciferase assay and qRT-PCR. Hsa-miR-216b-5p was also knocked down in LINC01518-downregulated HTF cells to investigate the function of this lncRNA-miRNA epigenetic axis in TGF-β1-treated HTF cells. LINC01518 was upregulated in human glaucoma tissues and cultured HTF cells. LINC01518 downregulation significantly suppressed TGF-β1-induced cell proliferation, migration and autophagy signaling pathway in HTF cells. Hsa-miR-216b-5p was confirmed to be a ceRNA target of LINC01518. Knocking down hsa-miR-216b-5p reversed the suppressing effects of LINC01518 downregulation in TGF-β1-treated HTF cells. Our study demonstrated that LINC01518 is a functional factor in regulating proliferation and migration in TGF-β1-treated HTF cells, and hsa-miR-216b -5p may also be involved. Targeting the epigenetic axis of LINC01518/hsa-miR-216b-5p may provide new insight into the pathological development of human glaucoma.

TGFβ1, MMPs and cytokines profiles in ocular surface: Possible tear biomarkers for pseudoexfoliation

Purpose

Pseudoexfoliation (PXF) is a unique form of glaucoma characterized by accumulation of exfoliative material in the eyes. Changes in tear profile in disease stages may give us insights into molecular mechanisms involved in causing glaucoma in the eye.

Methods

All patients were categorized into three main categories; pseudoexfoliation (PXF), pseudoexfoliation glaucoma (PXG) and cataract, which served as control. Cytokines, transforming growth factor β1 (TGFβ1), matrix metalloproteases (MMPs) and fibronectin (FN1) were assessed with multiplex bead assay, enzyme-linked immunosorbent assay (ELISA), gelatin zymography, and immunohistochemistry (IHC) respectively in different ocular tissues such as tears, tenon’s capsule, aqueous humor (AH) and serum samples of patients with PXF stages.

Results

We found that TGFβ1, MMP-9 and FN1 protein expression were upregulated in tears, tenon’s capsule and AH samples in PXG compared to PXF, though the MMP-9 protein activity was downregulated in PXG compared with control or PXF. We have also found that in PXG tears sample the fold change of TGF-α (Transforming Growth Factor-α), MDC (Macrophage Derived Chemokine), IL-8 (Interleukin-8), VEGF (Vascular Endothelial Growth Factor) were significantly downregulated and the levels of GM-CSF (Granulocyte Macrophage Colony Stimulating Factor), IP-10 (Interferon- γ produced protein-10) were significant upregulated. While in AH; IL-6 (Interleukin-6), IL-8, VEGF, IFN-a2 (Interferon- α2), GRO (Growth regulated alpha protein) levels were found lower and IL1a (Interleukin-1α) level was higher in PXG compared to PXF. And in serum; IFN-a2, Eotaxin, GM-CSF, Fractalkine, IL-10 (Interleukin-10), IL1Ra (Interleukin-1 receptor antagonist), IL-7 (Interleukin-7), IL-8, MIP1β (Macrophage Inflammatory Protein-1β), MCP-1 (Monocyte Chemoattractant Protein-1) levels were significantly upregulated and PDGF-AA (Platelet Derived Growth Factor-AA) level was downregulated in the patients with PXG compared to PXF.

Conclusions

Altered expression of these molecules in tears may therefore be used as a signal for onset of glaucoma or for identifying eyes at risk of developing glaucoma in PXF.

Early-onset Exfoliation Syndrome: A Literature Synthesis

PRECIS

We conducted a literature review of younger patients with exfoliation syndrome (XFS) in an attempt to identify case similarities and better understand disease etiology.

PURPOSE

XFS that predisposes to secondary glaucoma is a strongly age-related condition. We performed a literature review of XFS and exfoliation glaucoma (XFG) in patients aged younger than 40 years to examine potential common characteristics and gain clues to its etiology.

METHODS

We conducted a broad literature search with appropriate keywords and manually extracted key demographic and ocular features on younger XFS and XFG cases. Articles that did not provide past ocular history on early-onset XFS/XFG were excluded.

RESULTS

We identified 12 cases of XFS and XFG in patients from 13 to 40 years old (8 females; 11 White; 5 from Iran). All had past ocular history remarkable for intraocular surgery for other glaucoma conditions (7 cases), other ocular diseases (3 cases), or ocular trauma (2 cases).

CONCLUSIONS

All reported early-onset XFS and XFG cases arise in the setting of events that produced a significant disruption of the blood-aqueous barrier. Understanding the metabolic alterations of aqueous humor from such cases could provide clues regarding how exfoliation material forms.

Pseudoexfoliation syndrome in diabetic patients: transmission electron microscopy study of anterior lens epithelial cells

Purpose: to examine the lens epithelial cells in diabetic patients with pseudoexfoliation to ultramicroscope and to compare the findings with those of patients without diabetes mellitus (DM) and/or without pseudoexfoliation (PEX).

Materials and Methods: Forty patients aged 65-86 years were enrolled in the study. All patients had senile cataract and were divided into four groups of ten patients in each group. Group I: patients without pseudoexfoliation, without DM, Group II: without pseudoexfoliation, with DM, Group III: with pseudoexfoliation, without DM, Group IV (Pseudoexfoliation-Diabetic Group): with pseudoexfoliation, with DM. In all cases, part of the central portion of anterior lens capsule was removed during routine cataract surgery, and was properly prepared in order to be examined under a transmission electron microscope.

Results: In the control group, mainly degenerative alterations to varying extents were observed. In all groups, intracellular and extracellular oedema, multilayering, apoptosis, completely destroyed cells adjacent to normal cellswere described. In the diabetic group, alterations were more severe with respect to group I. In PEX cases, the additionalirregularity of the epithelium surface, loose intercellular connection, as well as the loose connection between cells and basement membrane were described with the presence of PEX material free and within the basement membrane. In cases with PEX and DM, degenerative alterations and PEX material were observed as well, but the epithelium was better conserved compared to the PEX group.

Conclusion: the observed lesions were more extended and more frequent in the pseudoexfoliation group, followed by the diabetic group. The pseudoexfoliation-diabetic group presented less intense modifications raising questions about the interaction of these different diseases.

Abbreviations: DM = Diabetes Mellitus, PEX = Pseudoexfoliation, PXM = Pseudoexfoliative Material, AD = Alzheimer disease, TGF-β1 = Transforming Growth Factor beta 1, WHO = World Health Organization, LEC = Lens Epithelium Cells, BM = Basement Membrane, CM = Cytoplasmic Membrane

Aqueous autotaxin and TGF-βs are promising diagnostic biomarkers for distinguishing open-angle glaucoma subtypes

The purpose of this study is to examine if aqueous autotaxin (ATX) and TGF-β levels could be used for differentiating glaucoma subtypes. This prospective observational study was performed using aqueous humor samples obtained from 281 consecutive patients. Open angle glaucoma patients were classified into three groups: primary open-angle glaucoma (POAG), secondary open-angle glaucoma (SOAG), and exfoliation glaucoma (XFG). Aqueous levels of ATX and TGF-βs were quantified. The AUC as well as sensitivity and specificity for the classification into normal and glaucoma subtypes using four indicators-ATX, TGF-β1, TGF-β2, and TGF-β3, upon the application of three machine learning methods. ATX, TGF-β1, and TGF-β3 were positively correlated with IOP, and ATX was significantly and negatively correlated with the mean deviation. From least absolute shrinkage and selection operator regression analysis, the AUC values to distinguish each subgroup [normal, POAG, SOAG, and XFG] ranged between 0.675 (POAG vs. normal) and 0.966 (XFG vs. normal), when four variables were used. High AUC values were obtained with ATX for discriminating XFG from normal eyes and with TGF-β3 for discriminating XFG from normal eyes, POAG, or SOAG. Aqueous TGF-β and ATX exhibited high diagnostic performance in detecting glaucoma subtypes, and could be promising biomarkers for glaucoma.

Long-term myofibroblast persistence in the capsular bag contributes to the late spontaneous in-the-bag intraocular lens dislocation

Late spontaneous in-the-bag intraocular lens (IOL) dislocation is a complication presenting 6 months or later after cataract surgery. We aimed to characterize the cells in the lens capsules (LCs) of 18 patients with spontaneous late in-the-bag IOL dislocation. Patients' average age was 82.6 ± 1.5 years (range 72-98), and most of them had pseudoexfoliation syndrome (PEX). Cells from the LCs were positive for myofibroblast (αSMA), proliferation (Ki-67, PCNA), early lens development/lens progenitor (SOX2, PAX6), chemokine receptor (CXCR4), and transmembrane (N-cadherin) markers, while negative for epithelial (E-cadherin) marker. Moreover, the cells produced abundant fibronectin, type I and type V collagen in the nearby extracellular matrix (ECM). During ex vivo cultivation of dislocated IOL-LCs in toto, the cells proliferated and likely migrated onto the IOL's anterior side. EdU proliferation assay confirmed the proliferation potential of the myofibroblasts (MFBs) in dislocated IOL-LCs. Primary cultured lens epithelial cells/MFBs isolated from the LC of dislocated IOLs could induce collagen matrix contraction and continuously proliferated, migrated, and induced ECM remodeling. Taken together, this indicates that long-lived MFBs of dislocated IOLs might contribute to the pathogenic mechanisms in late in-the-bag IOL dislocation.

Posterior capsule opacification: What's in the bag?

Cataract, a clouding of the lens, is the most common cause of blindness in the world. It has a marked impact on the wellbeing and productivity of individuals and has a major economic impact on healthcare providers. The only means of treating cataract is by surgical intervention. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior capsule and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens (IOL). The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. Lens epithelial cells, however, remain attached to the anterior capsule, and in response to surgical trauma initiate a wound-healing response that ultimately leads to light scatter and a reduction in visual quality known as posterior capsule opacification (PCO). There are two commonly-described forms of PCO: fibrotic and regenerative. Fibrotic PCO follows classically defined fibrotic processes, namely hyperproliferation, matrix contraction, matrix deposition and epithelial cell trans-differentiation to a myofibroblast phenotype. Regenerative PCO is defined by lens fibre cell differentiation events that give rise to Soemmerring's ring and Elschnig's pearls and becomes evident at a later stage than the fibrotic form. Both fibrotic and regenerative forms of PCO contribute to a reduction in visual quality in patients. This review will highlight the wealth of tools available for PCO research, provide insight into our current knowledge of PCO and discuss putative management of PCO from IOL design to pharmacological interventions.

Involvement of autotaxin in the pathophysiology of elevated intraocular pressure in Posner-Schlossman syndrome

To examine whether autotaxin (ATX) in the aqueous humor causes elevated intraocular pressure (IOP) in patients with Posner-Schlossman syndrome (PSS). ATX and transforming growth factor beta (TGF-β) in the aqueous humor were quantified in PSS patients. The expression of ATX and TGF-β in cytomegalovirus (CMV)-infected-human trabecular meshwork (hTM) cells was examined. Biological changes in hTM cells and monkey Schlemm’s canal endothelial (SCE) cells cultured in the conditioned medium of CMV-infected hTM cells were analyzed. The expression of ATX and TGF-β1 was upregulated in the aqueous humor of CMV-positive PSS patients, and the level of ATX in the aqueous humor was positively correlated with IOP. CMV infection upregulated ATX and TGF-β1 in hTM cells. The conditioned medium induced fibrotic changes in hTM cells and reduced SCE permeability, which was attenuated by an ATX inhibitor, a lysophosphatidic acid receptor antagonist, and a Rho kinase inhibitor. ATX in the aqueous humor induced by CMV infection may trigger elevated IOP. Modulating ATX activity may be a novel treatment modality for PSS.

Recent advances in risk factors associated with ocular exfoliation syndrome

Exfoliation syndrome is generally considered a progressive age-related systemic disorder of the extracellular matrix, which is clinically characterized through the observation of flaky white aggregates on ocular tissues. Exfoliation syndrome is directly linked to exfoliative glaucoma in elderly patients, where it is known as the most common identifiable cause of open-angle glaucoma. Despite the identification of various risk factors associated with exfoliation syndrome, the exact pathogenesis of this syndrome has not been fully elucidated. There is a growing number of genome-wide association studies in different populations around the world to identify genetic factors underlying exfoliation syndrome. Besides variants in LOXL1 and CACNA1A genes, new loci have been recently identified which are believed to be associated with exfoliation syndrome. Among different genetic factors, functional variants might help to better understand mechanisms underlying this systemic disorder. Besides genetic factors, epigenetic regulation of different gene expression patterns has been thought to play a role in its pathogenesis. Other factors have been also considered to be involved in the development of exfoliation syndrome at cellular organelles level where mitochondrial impairment and autophagy dysfunction have been suggested in relation to exfoliation syndrome. This review addresses the most recent findings on genetic factors as well as cellular and molecular mechanisms involved in both the development and progression of exfoliation syndrome.

Lysyl Oxidase Like 1: Biological roles and regulation

Lysyl Oxidase Like 1 (LOXL1) is a gene that encodes for the LOXL1 enzyme. This enzyme is required for elastin biogenesis and collagen cross-linking, polymerising tropoelastin monomers into elastin polymers. Its main role is in elastin homeostasis and matrix remodelling during injury, fibrosis and cancer development. Because of its vast range of biological functions, abnormalities in LOXL1 underlie many disease processes. Decreased LOXL1 expression is observed in disorders of elastin such as Cutis Laxa and increased expression is reported in fibrotic disease such as Idiopathic Pulmonary Fibrosis. LOXL1 is also downregulated in the lamina cribrosa in pseudoexfoliation glaucoma and genetic variants in the LOXL1 gene have been linked with an increased risk of developing pseudoexfoliation glaucoma and pseudoexfoliation syndrome. However the two major risk alleles are reversed in certain ethnic groups and are present in a large proportion of the normal population, implying complex genetic and environmental regulation is involved in disease pathogenesis. It also appears that the non-coding variants in intron 1 of LOXL1 may be involved in the regulation of LOXL1 expression. Gene alteration may occur via a number of epigenetic and post translational mechanisms such as DNA methylation, long non-coding RNAs and microRNAs. These may represent future therapeutic targets for disease. Environmental factors such as hypoxia, oxidative stress and ultraviolet radiation exposure alter LOXL1 expression, and it is likely a combination of these genetic and environmental factors that influence disease development and progression. In this review, we discuss LOXL1 properties, biological roles and regulation in detail with a focus on pseudoexfoliation syndrome and glaucoma.

HLSC-Derived Extracellular Vesicles Attenuate Liver Fibrosis and Inflammation in a Murine Model of Non-alcoholic Steatohepatitis

Extracellular vesicles (EVs) are membrane vesicles released virtually by all cell types. Several studies have shown that stem cell-derived EVs may mimic both in vitro and in vivo the biological effects of the cells. We recently demonstrated that non-alcoholic steatohepatitis (NASH) is inhibited by treatment with human liver stem cells (HLSCs). The aim of the present study was to evaluate whether EVs released by HLSCs influence the progression of NASH, induced by a diet deprived of methionine and choline, in immunocompromised mice. EV treatment was initiated after 2 weeks of diet with a biweekly administration of three different doses. Bio-distribution evaluated by optical imaging showed a preferential accumulation in normal and, in particular, in fibrotic liver. EV treatment significantly improved liver function and reduced signs of liver fibrosis and inflammation at both morphological and molecular levels. In particular, we observed that, out of 29 fibrosis-associated genes upregulated in NASH liver, 28 were significantly downregulated by EV treatment. In conclusion, HLSC-derived EVs display anti-fibrotic and anti-inflammatory effects in a model of chronic liver disease, leading to an improvement of liver function.

Extracellular Matrix Regulation and Dysregulation in Exfoliation Syndrome

Several lines of evidence, such as ultrastructural signs for activated fibrillogenesis and excessive production of elastic microfibrillar components in the anterior segment of the eye and throughout the body, indicate that exfoliation syndrome (XFS) is an elastic microfibrillopathy, leading to the accumulation of an abnormal extracellular fibrillar material (XFM). The upregulation of elastic microfibrillar components is paralleled by the selective upregulation of the cross-linking enzyme lysyl oxidase-like 1 (LOXL1) in the early phase of the disease, suggesting that LOXL1 participates in the stabilization of newly synthesized elastic proteins and finally in the stable accumulation of XFM. Whereas the excessive production of elastic proteins rises from early to late XFS stages, possibly mediated by increasing fibrogenic stimuli in the aqueous humor, LOXL1 is downregulated in late stages of the disease by as yet unknown mechanisms, possibly leading to the well-documented elastotic matrix alterations characteristic of eyes with late stage XFS. Several studies indicate complex changes of the proteolytic balance in the anterior segment of XFS eyes, characterized primarily by decreased matrix metalloproteinase-2 activity, the major aqueous matrix metalloproteinase, potentially leading to a shift from appropriate matrix turnover to progressive matrix accumulation. In contrast, in nearly all tissues of the posterior segment, XFM seems to be absent and differential gene expression is confined to the lamina cribrosa, characterized by a stage-independent, primary, and XFS-specific downregulation of LOXL1 and elastic components in XFS eyes. Concomitant with this deficiency, the laminar elastic fiber network displays prominent ultrastructural alterations, which may lead to increased vulnerability to glaucomatous damage. Various growth factors, stress conditions, or dietary factors have been supposed to potentially influence the manifestation of the disease. However, in spite of increasing knowledge, the pathogenetic factors initiating the abnormal matrix process still remain elusive. Such information would be critical for our understanding of disease progression and would disclose new options for pharmaceutical intervention at the onset of the disease.

Molecular Biology of Exfoliation Syndrome

Exfoliation syndrome (XFS) is a common age-related matrix process resulting from excessive production and disordered assembly of elastic microfibrillar components into highly cross-linked fibrillary aggregates throughout the anterior eye segment and various organ systems. The underlying molecular pathophysiology involves a complex interplay of profibrotic protagonists including growth factors, proteolytic enzymes and inhibitors, proinflammatory cytokines, chaperones, and dysregulated stress response pathways including insufficient autophagy. Interaction between individual genetic predisposition and stress factors is a plausible theory explaining the development of XFS in the aging individual. Genome-wide association studies have identified robust genetic associations with LOXL1, CACNA1A, and 5 additional genes including POMP and TMEM136, which provide new biological insights into the pathology of XFS and highlight a role for abnormal matrix cross-linking processes, Ca channel deficiency, blood-aqueous barrier dysfunction, and abnormal ubiquitin-proteasome signaling in XFS pathophysiology. However, the exact pathophysiological mechanisms, the functional role of genetic risk variants, and gene-environment interactions still remain to be characterized.

Histopathology of Exfoliation Syndrome

Exfoliation syndrome (XFS) is characterized by light and electron microscopy by age-dependent gradual accumulation of whitish material of largely unknown composition and origin along both the anterior and posterior chambers and widely within the iris stroma. These deposits can be fairly specifically labeled with selected antibodies and lectins. Immunohistochemistry shows that intraocular exfoliation deposits share antigens with the microfibrillar elastic fiber system and several basement membrane components, including carbohydrate epitopes on glycosaminoglycans, proteoglycans, and cell adhesion molecules. The earliest histopathologic manifestation of XFS seems to be the deposition of characteristic fibers in various extraocular and anterior segment tissues, as observed by electron microscopy, and perivascular deposition of material within the iris stroma, which is antigenically typical of that found in classic intraocular exfoliation deposits. These findings precede the clinical diagnosis of XFS and likewise can be detected in the seemingly uninvolved fellow eyes of patients with clinically unilateral XFS. Indeed, histopathologic examination of capsulotomy, iridectomy, and trabeculectomy specimens can lead to a clinically unexpected diagnosis of XFS. Exfoliation fibers are additionally found widely distributed in extraocular connective tissues and visceral organs, but the matrix of these fibers seems to differ from that of intraocular deposits. In addition to this histopathologic discrepancy, both the frequent occurrence of clinically unilateral, histopathologically highly asymmetric exfoliation deposits, and the relationship between the early iris vasculopathy that not infrequently may be observed histopathologically for years before classic widespread exfoliation deposits appear along the anterior and posterior chambers remain to be resolved.

Effects of Salidroside on Trabecular Meshwork Cell Extracellular Matrix Expression and Mouse Intraocular Pressure

Purpose

Excessive accumulation of extracellular matrix (ECM) in the trabecular meshwork (TM) reduces aqueous humor outflow, which likely contributes to elevation of IOP in primary open-angle glaucoma (POAG). Salidroside, a phenolic glycoside isolated from Rhodiola rosea is reported to prevent profibrotic responses by inhibiting Smad signaling pathway activated by TGF-β in liver, lung, and kidney tissues. We tested if salidroside can (1) inhibit TGF-β2-induced ECM expression in cultured human TM cells, and (2) lower TGF-β2-induced ocular hypertension in the mouse.

Methods

Cultured human TM cells stimulated with 5 ng/mL TGF-β2 for 48 hours were treated with salidroside for 24 hours. The expressions of fibronectin (FN), collagen type IV (COL-IV), and laminin (LN) were evaluated by quantitative PCR, Western blot, and immunocytochemistry. BALB/cJ mice were injected intravitreally with an adenoviral vector encoding a bioactive mutant of TGF-β2 (Ad.hTGF-β2226/228) in one eye to induce ocular hypertension, with the uninjected contralateral or Ad.Empty-injected eyes serving as controls. Mice were treated with a daily intraperitoneal injection of 40 mg/kg salidroside. Conscious mouse IOP values were measured using a TonoLab rebound tonometer.

Results

In cultured human TM cells, treatment with TGF-β2 increased expressions of FN, COL-IV, and LN, as assessed by quantitative PCR, Western blotting, and immunocytochemistry, all of which were significantly and completely ameliorated by 30 μM salidroside. Daily intraperitoneal injections of salidroside (40 mg/kg), starting either at day 0 (same day as Ad.hTGF-β2226/228 injection) or at day 14, significantly lowered TGF-β2-induced ocular hypertension in the mouse. In contrast, salidroside did not affect IOP of control eyes.

Conclusions

These results demonstrated that salidroside is capable of minimizing TGF-β2-induced ECM expression in cultured human TM cells. It also reduced TGF-β2-induced ocular hypertension in the mouse. These findings indicate that this phenolic glycoside may be useful as a novel treatment for POAG.

Aqueous humor levels of TGFβ2 and SFRP1 in different types of glaucoma

BACKGROUND

To assess bioactive transforming growth factor-β2 (TGFβ2) and secreted frizzled-related protein-1 (SFRP1) levels in aqueous humor (AH) of different types of glaucoma.

METHODS

AH samples were obtained immediately before ophthalmic surgery with a 27-gauge needle attached to a microsyringe from 126 eyes (105 patients) divided into five groups: cataract (control), primary open-angle glaucoma (POAG), chronic angle-closure glaucoma (CACG), primary angle-closure suspects (PACS), and acute angle-closure glaucoma (AACG). Bioactive TGFβ2 and SFRP1 levels were assayed by ELISA.

RESULTS

The concentration of TGFβ2 in AH of POAG patients, but not CACG, PACS, or AACG patients, was significantly higher than control eyes. However, within the AACG group, although the TGFβ2 levels in AH did not differ significantly from the control level when all AACG patients were grouped together, there were differences when the AACG patients were divided into high and normal intraocular pressure (IOP); TGFβ2 of AACG patients with high IOP (> 21 mmHg) was significantly higher than those with normal IOP. AH levels of SFRP1 were not significantly different among the groups. However, a statistical significant, negative correlation between SFRP1 and IOP existed in the POAG group. POAG patients with high IOP had lower levels of SFRP1 than those with normal IOP. In contrast, a significant, positive correlation between SFRP1 level and IOP was detected in the AACG group. AACG patients with high IOP had a higher level of SFRP1 than those with normal IOP. Concentrations of TGFβ2 and SFRP1 did not correlate significantly with each other, or with age.

CONCLUSIONS

These results indicate that AH levels of TGFβ2 and SFRP1 showed different profiles in different types of glaucomas.

Transient expression of Wnt5a elicits ocular features of pseudoexfoliation syndrome in mice

PURPOSE

Pseudoexfoliation (PEX) syndrome is an age-related systemic disease with ocular manifestations. The development of animal models is critical in order to elucidate the cause of the disease and to test potential treatment regimens. The purpose of this study is to report phenotypes found in mouse eyes injected with Adenovirus coding Wnt5a. Some of the phenotypes resemble those found in PEX patients while others are different.

METHODS

Recombinant Adenovirus coding Wnt5a or green fluorescent protein (GFP) were injected into mouse eyes. Two months after the injection, eyes were examined for PEX phenotypes using slit lamp, fluorescence stereomicroscope, histological staining, immunostaining and transmission electron microscope.

RESULT

Certain ocular features of PEX syndrome were found in mouse eyes injected with recombinant Adenovirus coding Wnt5a. These features include accumulation of exfoliation-like extracellular material on surfaces of anterior segment structures and its dispersion in the anterior chamber, saw-tooth appearance and disrupted basement membrane of the posterior iris pigment epithelium, iris stromal atrophy and disorganized ciliary zonules. Ultrastructure analysis of the exfoliation material revealed that the microfibril structure found in this model was different from those of PEX patients.

CONCLUSION

These features, resembling signs of ocular PEX syndrome in patients, suggest that new information obtained from this study will be helpful for developing better mouse models for PEX syndrome.

Review of Biomarkers in Ocular Matrices: Challenges and Opportunities

Biomarkers provide a powerful and dynamic approach to improve our understanding of the mechanisms underlying ocular diseases with applications in diagnosis, disease modulation or for predicting and monitoring of clinical response to treatment. Defined as measurable indicator of normal or pathological processes, biomarker evaluation has been used extensively in drug development within clinical settings to better comprehend effectiveness of treatment in ocular diseases. Biomarkers in the eye have the advantage of access to multiple ocular matrices via minimally invasive methods. Repeat sampling for biomarker assessment has enabled reproducible objective measures of disease process or biological responses to a drug treatment. This review describes the usage of biomarkers with respect to four commonly sampled ocular matrices in clinic: tears, conjunctiva, aqueous humor and vitreous. Issues that affect the evaluation of biomarkers are discussed along with opportunities to leverage biomarkers such that ultimately, they can be used for customized targeted therapy.

Human Trabecular Meshwork Progenitors

Trabecular meshwork (TM) cells are a group of progenitors that have the ability to become adipocytes, chondrocytes and endothelial cells. Therefore, those adult corneal progenitors may be used as an effective therapy for trabecular meshwork diseases such as glaucoma, corneal endothelial dysfunctions such as blindness due to corneal endothelial dysfunction, and similar diseases. In order to promote the understanding of human trabecular meshwork progenitors, this article reviews human trabecular meshwork progenitor therapy and discusses its potential applications for curing human eye blindness.

The role of focal adhesion kinase in transforming growth factor-β2 induced migration of human lens epithelial cells

The migration of lens epithelial cells towards the posterior capsule is a key event in the development of posterior capsule opacification (PCO). Accumulating evidence has described crosstalk between growth factors and adhesive signaling pathways in wound healing and cell migration. The aim of the present study was to elucidate an aberrant transforming growth factor (TGF)‑β2 signaling pathway that regulated the migration of lens epithelial cells in the pathological context of PCO. The expression of fibronectin, focal adhesion kinase (FAK) and phosphorylated (p)‑FAK in HLE‑B3 cells following TGF‑β2 treatment was determined by western blot analysis and the expression of integrin α5β1 was detected by flow cytometry. Cell migration capacity was measured by wound healing and Transwell assays in the presence of 1,2,4,5‑tetraaminobenzene tetrahydrochloride, a selective FAK inhibitor, fibronectin small interfering RNA interference, arginylglycylaspartic acid peptides or α5β1‑integrin neutralizing antibodies. The 1,2,4,5‑tetraaminobenzene tetrahydrochloride was administered daily to 16 rabbits following cataract surgery. Fibronectin and TGF‑β expression were increased in the PCO group, demonstrated by immunofluorescence assays. PCO grading was conducted by slit‑lamp biomicroscopy and evaluation of posterior capsule opacification software. It was observed that TGF‑β2 promoted HLE‑B3 cell migration and upregulated fibronectin expression, which was followed by an increased phosphorylation of FAK. In addition, TGF‑β2 treatment and fibronectin surface coating significantly increased cell migration and FAK activation, which was inhibited by disrupting fibronectin‑integrin α5β1 interaction with the arginylglycylaspartic acid peptide, α5β1‑integrin neutralizing antibody or fibronectin depletion. Finally, suppression of FAK signaling by its inhibitor significantly decreased cell migration in vitro and attenuated PCO development in vivo. In summary, TGF‑β2 was indicated to promote the migration of lens epithelial cells through the TGF‑β2/fibronectin/integrin/FAK axis. Inhibition of FAK activity decreased TGF‑β2‑mediated cell migration in vitro and improved the symptoms of PCO in a rabbit model.

Increased aqueous autotaxin and lysophosphatidic acid levels are potential prognostic factors after trabeculectomy in different types of glaucoma

We explored the potential relevance of aqueous lysophosphatidic acid (LPA) and autotaxin (ATX) levels on postoperative outcomes of trabeculectomy, and the effects of ATX on fibrotic response in cultured human conjunctiva fibroblast (HCF) cells. We enrolled 70 glaucomatous eyes which underwent trabeculectomy, and quantified aqueous LPA and ATX. Those eyes were followed up for 12 months, and postoperative filtering blebs were evaluated using anterior segment optical coherence tomography. Also, the ATX-induced fibrotic changes in HCFs and the effects of an ATX inhibitor were assessed. Measured aqueous ATX and LPA levels were significantly different between glaucoma subtypes. In multivariate analyses, aqueous ATX levels were significantly correlated with the presence of needlings at 1, 3, 6 and 12 months after surgery. Exfoliative glaucoma, whose ATX level was significantly high, showed significantly increased numbers of needlings and a lower cumulative success rate without needlings. An in vitro study showed that fibrotic changes were upregulated by ATX treatment in HCFs, which was significantly suppressed by an ATX inhibitor. We presently demonstrate that aqueous ATX may be a prognostic factor affecting the fibrotic response in HCFs and bleb formation, and inhibition of ATX could be a therapeutic target after trabeculectomy.

Human Liver Stem Cell-Derived Extracellular Vesicles Prevent Aristolochic Acid-Induced Kidney Fibrosis

With limited therapeutic intervention in preventing the progression to end-stage renal disease, chronic kidney disease (CKD) remains a global health-care burden. Aristolochic acid (AA) induced nephropathy is a model of CKD characterised by inflammation, tubular injury, and interstitial fibrosis. Human liver stem cell-derived extracellular vesicles (HLSC-EVs) have been reported to exhibit therapeutic properties in various disease models including acute kidney injury. In the present study, we aimed to investigate the effects of HLSC-EVs on tubular regeneration and interstitial fibrosis in an AA-induced mouse model of CKD. NSG mice were injected with HLSC-EVs 3 days after administering AA on a weekly basis for 4 weeks. Mice injected with AA significantly lost weight over the 4-week period. Deterioration in kidney function was also observed. Histology was performed to evaluate tubular necrosis, interstitial fibrosis, as well as infiltration of inflammatory cells/fibroblasts. Kidneys were also subjected to gene array analyses to evaluate regulation of microRNAs (miRNAs) and pro-fibrotic genes. The effect of HLSC-EVs was also tested in vitro to assess pro-fibrotic gene regulation in fibroblasts cocultured with AA pretreated tubular epithelial cells. Histological analyses showed that treatment with HLSC-EVs significantly reduced tubular necrosis, interstitial fibrosis, infiltration of CD45 cells and fibroblasts, which were all elevated during AA induced injury. At a molecular level, HLSC-EVs significantly inhibited the upregulation of the pro-fibrotic genes α-Sma, Tgfb1, and Col1a1 in vivo and in vitro. Fibrosis gene array analyses revealed an upregulation of 35 pro-fibrotic genes in AA injured mice. Treatment with HLSC-EVs downregulated 14 pro-fibrotic genes in total, out of which, 5 were upregulated in mice injured with AA. Analyses of the total mouse miRnome identified several miRNAs involved in the regulation of fibrotic pathways, which were found to be modulated post-treatment with HLSC-EVs. These results indicate that HLSC-EVs play a regenerative role in CKD possibly through the regulation of genes and miRNAs that are activated during the progression of the disease.