Effects of ROCK Inhibitors on Apoptosis of Corneal Endothelial Cells in CMV-Positive Posner-Schlossman Syndrome Patients

The inhibitory effects of live and UV-killed Akkermansia muciniphila and its derivatives on cytotoxicity and inflammatory response induced by Clostridioides difficile RT001 in vitro

Clostridioides difficile infection (CDI) is the leading cause of healthcare-acquired infections worldwide. Probiotics are widely recommended to prevent CDI and its recurrences. Akkermansia muciniphila, as a therapeutic symbiont colonizing the intestinal mucosal layer, is considered to be a promising next-generation probiotic. In this work, we assessed the inhibitory effects of A. muciniphila MucT and its derivatives on cytotoxicity and inflammatory response induced by C. difficile RT001 in Caco-2 cells. The results obtained from SEM revealed that the morphology of UV-killed A. muciniphila remained unchanged after UV inactivation. TEM analysis showed that A. muciniphila-isolated extracellular vesicles (EVs) were spherical and ranged from 50 to 200 nm in size. Toxigenic supernatant (Tox-S) of C. difficile RT001 (500 μg/ml) significantly (P <0.01) reduced the cell viability of Caco-2 cells. Caco-2 cells treated with live (MOI 10), UV-killed (MOI 10), cell-free supernatant (CFS, 106 cfu/ml), and EVs (20 μg/ml) of A. muciniphila exhibited over 90% viability in comparison to untreated control. The neutralized CFS preparation using A. muciniphila and its derivatives could notably reduce the expression level of inflammatory markers. Additionally, A. muciniphila and its derivatives modulated the production of IL-1β, TNF-α, and IL-10 in Tox-S stimulated Caco-2 cells. We demonstrated that A. muciniphila and its derivatives can modulate changes in the gut barrier-related genes and inflammatory response caused by C. difficile Tox-S in Caco-2 cells.

Comparison Between Two Types of Viral-Induced Anterior Uveitis In Vitro and In Vivo: A Stronger Response in Herpes Simplex Virus Type 1 Than in Murine Cytomegalovirus

Purpose

To observe the similarities and differences between herpes simplex virus type 1 (HSV-1) and murine cytomegalovirus (MCMV)-induced viral anterior uveitis (VAU), both in vitro and in vivo.

Methods

Primary rat trabecular meshwork cells (RTMCs) were infected by HSV-1 or MCMV to clarify the pattern of virus replication and the effect on cells. In vivo, intracameral injection of HSV-1 or MCMV was performed to establish the VAU rat models. The clinical manifestation, intraocular pressure (IOP), histological characteristics, ultrastructural changes, and the expression of inflammatory cytokines in the anterior segment were observed and compared between these two types of VAU models.

Results

Both viruses could infect the RTMCs but HSV-1 exhibited an earlier and greater cytopathic effect in vitro. In vivo, both VAU rats showed typical acute VAU signs, and the IOP elevation seemed to be correlated with the inflammatory progression. Histopathological findings and ultrastructural changes revealed tissue damage and cell infiltration in the anterior chamber angle. In both models, similar proinflammatory cytokines were upregulated. HSV-1 and MCMV viral particles were identified under transmission electron microscopy.

Conclusions

HSV-1 and MCMV infection share certain similarities but have significant differences both in vitro and in vivo. HSV-1 usually has a stronger anterior segment inflammation with a longer duration compared with MCMV in VAU models. Our results provided a valuable animal model for investigating pathogenesis and exploring therapeutic strategies for clinical VAU.

Clinical Differences between Posner-Schlossman Syndrome Patients with Intermittent Intraocular Pressure Elevation and Glaucomatous Damage

INTRODUCTION

Although there is abundant evidence that Posner-Schlossman syndrome (PSS) can lead to secondary glaucoma, data on the clinical differences between PSS patients with secondary glaucoma and those with intermittent intraocular pressure (IOP) elevation are sparse.

METHODS

This retrospective observational study included 52 patients (52 eyes) diagnosed with PSS and admitted to Zhongnan Hospital of Wuhan University between January 2019 and February 2022. Demographic characteristics and clinical features were gathered from admission records. Patients were divided into two groups: 27 cases with intermittent IOP elevation (group A) and 25 cases with secondary glaucoma (group B and C). Of the secondary glaucoma cases, 18 were further divided into the topical IOP-lowering medications group (group B) and 7 into the glaucoma surgery group (group C). Clinical characteristics of different groups were compared.

RESULTS

Compared to the intermittent IOP elevation group, PSS patients with secondary glaucoma had a longer course of disease, a higher incidence of iris depigmentation, lower best corrected visual acuity, lower endothelial cell density, and higher interferon-γ (IFN-γ) concentration and cytomegalovirus (CMV) deoxyribonucleic acid (DNA) copy number in the aqueous humor (all p < 0.05). Group C presented a higher CMV DNA copy number in the aqueous humor than groups A and B (p < 0.05). Compound trabeculectomy proved effective in group C, with a functional filter bleb and well-controlled IOP without disease progression after 1 year of follow-up.

CONCLUSION

Distinctive characteristics existed between PSS patients with secondary glaucoma and those with intermittent IOP elevation. Compound trabeculectomy appears to be an effective treatment option when IOP cannot be controlled through topical medications.

Risk factors associated with corneal endothelial cell density in Posner-Schlossman syndrome

PURPOSE

To investigate the risk factors related to corneal endothelial cell density (ECD) in patients with Posner-Schlossman syndrome (PSS).

PATIENTS AND METHODS

It was an observational retrospective study. We reviewed the medical records of patients with PSS who attended the ophthalmology department at Wuhan University Zhongnan Hospital from January 2019 to December 2021. 42 eyes of 42 patients with PSS were included in the study. Demographic characteristics and clinical manifestations were recorded. The clinical characteristics of PSS patients with reduced ECD were compared with PSS patients with normal ECD. Simple and multiple linear regression analyses were carried out to identify the risk factors for ECD in PSS.

RESULTS

The ECD-lowered group had a longer disease duration (P = 0.000), higher rate of occurrence of corneal edema (P = 0.039), higher cytomegalovirus (CMV) deoxyribonucleic acid (DNA) copy number (P = 0.044), higher interleukin-10 (IL-10) level in the aqueous humor (P = 0.044), and thinner average retinal nerve fiber layer (RNFL) thickness (P = 0.016) than the control group. The results of multiple linear regression analysis indicated that disease duration (β =  - 0.287, P = 0.024) and level of IL-10 in the aqueous humor (β =  - 0.408, P = 0.001) were significantly negatively associated with ECD, while average RNFL thickness (β = 0.330, P =  0.007) was significantly positively related to ECD in PSS.

CONCLUSION

A longer disease duration, higher degree of glaucomatous damage and elevated level of IL-10 in the aqueous humor were associated with reduced ECD in PSS.

Long-Term Surgical Outcomes and Possible Postoperative Complication with Severe Corneal Endothelial Cell Loss After Trabeculectomy for Cytomegalovirus-Associated Anterior Uveitis with Secondary Glaucoma

PURPOSE

We assess long-term surgical outcomes after an initial trabeculectomy for cytomegalovirus-associated anterior uveitis with secondary glaucoma (CMV-SG).

METHODS

We retrospectively reviewed the medical records of 16 eyes of 15 patients with CMV-SG and 157 eyes of 157 patients with primary open-angle glaucoma. The average follow-up period was approximately 3 years. Surgical success was defined as intraocular pressure (IOP) below 18 mmHg and at least 20% lower than baseline.

RESULTS

Kaplan-Meier survival analysis revealed that bleb survival rates were not significantly different in the CMV-SG and POAG groups (P = 0.75). Bullous keratopathy occurred in 2 of 16 eyes with CMV-SG postoperatively but did not occur in the POAG group. The corneal endothelial cell density decreased by 34.2 ± 22.7% in the CMV-SG group during an average follow-up period of 2.7 ± 2.0 years.

CONCLUSION

Trabeculectomy effectively controlled IOP in CMV-SG, but attention must be paid to corneal endothelial cell loss.

Clinical Characteristics of Posner-Schlossman Syndrome Patients in China

Background

To explore the clinical characteristics of Posner-Schlossman syndrome (PSS) patients in China, especially the risk factors associated with the dynamic changes of corneal endothelial cell (CEC) density and retinal nerve fiber layer (RNFL) thickness during the course of the disease.

Methods

In this retrospective cohort study, patients consequently suffering from PSS were recruited. Patients data including gender, age of onset, frequency of attack, and disease duration. We performed detailed ophthalmology examinations including intraocular pressure (IOP), best-corrected visual acuity (BCVA), slit-lamp examination, optical coherence tomography (OCT), assessing RNFL thickness, and determined CEC density in the outpatient department. The unaffected eyes served as control.

Results

We recruited 121 patients (eyes, n = 125), including 69 (57.0%) males and 52 (43.0%) females with Posner-Schlossman syndrome. The age of first-onset was 33.81 ± 13.63 years old. The majority of these patients were aged 20-50 years (80.2%). The peak IOP was 47.67 ± 13.31 mmHg in the affected eyes. The frequency of PSS attack was 2.7 ± 3.7 times per year. The disease duration was 9.5 ± 10.4 years. Among all patients, there were 27 (22.31%) patients with a history of digestive disorders, 25 (20.66%) patients with a history of allergies, and 24 (19.83%) patients with a history of infectious disease. In the affected eyes, CEC density (2532.94 ± 490.83/mm² vs. 2777.13 ± 356.87/mm², p < 0.001), the RNFL thickness of four quadrants (superior 105.46 ± 29.86 μm vs. 121.33 ± 17.30 μm, p < 0.001; temporal 74.58 ± 22.21 μm vs. 81.94 ± 18.20 μm, p = 0.009; inferior 110.50 ± 33.42 μm vs. 128.29 ± 14.39 μm, p < 0.001; nasal 54.85 ± 14.48 μm vs. 63.49 ± 15.40 μm, p < 0.001) and central papillary (87.11 ± 21.18 μm vs. 99.18 ± 7.97 μm, p < 0.001) were significantly reduced compared to the fellow eyes. The disease duration and recurrent frequency were significantly associated with CEC density (p < 0.001 and p = 0.029) and the disease duration was significantly associated with RNFL thickness (p = 0.002).

Conclusions

In this study, CEC loss and RNFL thinning were present in the affected eyes. Our results indicated that disease duration and recurrent frequency played an important role in the progression of PSS.

Role of Adrenomedullin 2/Intermedin in the Pathogenesis of Neovascular Age-Related Macular Degeneration

Adrenomedullin 2 (AM2; also known as intermedin) is a member of the adrenomedullin (AM) peptide family. Similarly to AM, AM2 partakes in a variety of physiological activities. AM2 has been reported to exert protective effects on various organ disorders; however, its significance in the eye is unknown. We investigated the role of AM2 in ocular diseases. The receptor system of AM2 was expressed more abundantly in the choroid than in the retina. In an oxygen-induced retinopathy model, physiological and pathologic retinal angiogenesis did not differ between AM2-knockout (AM2-/-) and wild-type mice. In contrast, in laser-induced choroidal neovascularization, a model of neovascular age-related macular degeneration, AM2-/- mice had enlarged and leakier choroidal neovascularization lesions, with exacerbated subretinal fibrosis and macrophage infiltration. Contrary to this, exogenous administration of AM2 ameliorated the laser-induced choroidal neovascularization-associated pathology and suppressed gene expression associated with inflammation, fibrosis, and oxidative stress, including that of VEGF-A, VEGFR-2, CD68, CTGF, and p22-phox. The stimulation of human adult retinal pigment epithelial (ARPE) cell line 19 cells with TGF-β2 and TNF-α induced epithelial-to-mesenchymal transition (EMT), whereas AM2 expression was also elevated. The induction of EMT was suppressed when the ARPE-19 cells were pretreated with AM2. A transcriptome analysis identified 15 genes, including mesenchyme homeobox 2 (Meox2), whose expression was significantly altered in the AM2-treated group compared with that in the control group. The expression of Meox2, a transcription factor that inhibits inflammation and fibrosis, was enhanced by AM2 treatment and attenuated by endogenous AM2 knockout in the early phase after laser irradiation. The AM2 treatment of endothelial cells inhibited endothelial to mesenchymal transition and NF-κB activation; however, this effect tended to be canceled following Meox2 gene knockdown. These results indicate that AM2 suppresses the neovascular age-related macular degeneration-related pathologies partially via the upregulation of Meox2. Thus, AM2 may be a promising therapeutic target for ocular vascular diseases.

Analysis of risk factors associated with secondary open-angle glaucoma in Posner-Schlossman syndrome: A retrospective case-control study

Background

Posner-Schlossman syndrome (PSS) is a relatively rare cause of chronic secondary open-angle glaucoma (OAG), but the exact cause is unknown. This study aimed to determine potential risk factors for OAG secondary to PSS and to provide a basis for early intervention in the development of PSS.

Methods

This was a retrospective case-control study. Nine cases diagnosed with PSS and seven cases diagnosed with OAG secondary to PSS were selected and their aqueous humor assays at the first occurrence of PSS were collected. Clinical characteristics including age, sex, disease duration, eye laterality, baseline visual acuity, maximum IOP, corneal endothelial cell density, visual field, retinal nerve fiber layer thickness, cup-to-disk ratio, keratic precipitates, anterior chamber inflammation, and aqueous humor cytokine assay results were compared between the two groups.

Results

The cytomegalovirus (CMV) positivity was 55.60% in patients with PSS and 100% in patients with OAG secondary to PSS. Corneal endothelial cell density was lower in patients with CMV-positive PSS (p = 0.0116). Concentrations of basic fibroblast growth factor (bFGF), interleukin (IL)-6, and vascular cell adhesion molecule (VCAM) in patients with PSS and IL-8, IL-6, and VCAM in patients with OAG secondary to PSS were higher than standard reference values; and IL-8 concentration was significantly higher in patients with OAG secondary to PSS (p = 0.0229). There were significant positive correlations between IL-8 and IL-6, IL-6 and VCAM (p = 0.0304, p = 0.0172) and a significant negative correlation between bFGF and vascular endothelial growth factor (VEGF) (p = 0.0497). Simultaneous increase of IL-8 and IL-6 concentration levels could be used as a cytokine indicator to predict secondary OAG in patients with PSS (p = 0.0095).

Conclusion

Simultaneous increase of IL-8 and IL-6 concentrations may be an important cause of accelerated secondary OAG in patients with PSS, with IL-8 playing a more critical role. IL-8 and IL-6 may be more reliable cytokine markers for predicting secondary OAG in PSS, However, the high possibility of secondary OAG in patients with CMV-positive PSS should not be ignored. Regulation of IL-8 and IL-6 levels may be a new strategy of preventing OAG secondary to PSS.

Ripasudil Eyedrops Ameliorated Bullous Keratopathy Complicated with Cytomegalovirus Corneal Endotheliitis: A Case Report

PURPOSE

We describe a case of bullous keratopathy complicated with cytomegalovirus (CMV) corneal endotheliitis that was successfully treated with ripasudil eye drops.

METHODS

A retrospective case report.

RESULTS

A 65-year-old female patient diagnosed with CMV-associated anterior uveitis in the right eye was referred to us when anterior uveitis recurred with bullous keratopathy. Initial best-corrected visual acuity (BCVA) was 0.4 (decimal visual acuity). Her condition did not improve with anti-CMV treatment, and BCVA decreased to 0.07. At this point, intraocular pressure (IOP) was 20 mmHg, and ripasudil eye drops were started for IOP control. After 1 month, not only had IOP decreased to 14 mm Hg but the condition of the corneal edema had also improved. The central corneal thickness decreased to a normal level, and the BCVA recovered to 0.8.

CONCLUSION

Ripasudil eye drops not only lower IOP in patients with CMV corneal endotheliitis but may also have the potential to treat bullous keratopathy.

Rho-kinase inhibitors: Role in corneal endothelial disorders

PURPOSE

This exhaustive review of published literature aims to put forth the current understanding, and experiences of the role Rho-kinase inhibitors play in the management of corneal endothelial disorders.

METHODS

A meticulous search for PubMed and Medline databases was carried out using keywords 'rho-kinase inhibitors', 'corneal endothelial disorders', 'rho-kinase inhibitors in corneal endothelial disorders', and 'fuchs endothelial corneal dystrophy'. The articles published in last five years relevant to the area of interest were selected and compiled in a chronological order to write this review.

RESULTS

Published research shows the proven role of rho-kinase inhibitors in promoting endothelial proliferation and suppressing its apoptosis. It has shown to be effective in the treatment of endothelial diseases and endothelial cell loss due to other causes in small clinical studies. It has also shown to promote growth of human corneal endothelial cell culture suitable for transplantation. The side effects of topical rho-kinase inhibitors are minimal and self-limiting.

CONCLUSION

Rho-kinase inhibitors show immense promise in providing a non-surgical therapy for treatment of endothelial disorders. If consistent results are demonstrated through large clinical trials then this can be a major breakthrough in treating endothelial decompensation and reduce our dependence on endothelial keratoplasty for the same.

Quantification of Iris Atrophy by Swept-Source Optical Coherence Tomography in Posner-Schlossman Syndrome

Purpose: To investigate iris atrophy in Posner−Schlossman syndrome (PSS). Methods: Sixty-one patients with PSS were included. Using swept-source optical coherence tomography, the thickness of anterior border layer (A), middle stromal layer (M), and the posterior pigmented epithelial layer (P) of iris were measured at 500 μm, 1000 μm, 1500 μm, 2000 μm, and 2500 μm from the pupillary edge in both PSS-affected and fellow eyes. The relationships between iris thickness and corneal endothelium density, cup-to-disc (C/D) ratio, and retinal nerve fiber layer (RNFL) thickness were also estimated in PSS-affected eyes. Results: Iris thickness parameters, including M500, M1000, A1500, A2000, P2000, and P2500, were significantly thinner in PSS-affected eyes than in fellow eyes (all p < 0.05). Moreover, M500 and M1000 were significantly associated with corneal endothelium density (p = 0.047 and 0.018, respectively), and M500 was significantly associated with C/D ratio (p = 0.001) and RNFL thickness (p = 0.037) in PSS-affected eyes. Conclusions: Iris showed significant thinning and atrophy in PSS-affected eyes, and iris stromal thickness close to the pupillary edge could be a novel clinical predictor of the changes in corneal endothelium, C/D ratio, and RNFL thickness in PSS.

RhoA improves cryopreservation of rooster sperm through the Rho/RhoA-associated Kinase/cofilin pathway

Cryopreservation of rooster sperm leads to relatively low semen quality due to cytoskeletal damage during the freeze-thawing process. This study aimed to explore how the addition of RhoA recombinant protein affected the viability and subcellular structure of rooster sperm after freeze-thawing and elucidated the molecular mechanisms of sperm cryopreservation. Semen quality and acrosome integrity testing revealed that the addition of 0.5 μg/mL RhoA recombinant protein to the cryoprotectant fluid significantly increased sperm motility, survival rate, linearity, straight-line velocity, and acrosome integrity after freeze-thawing (P < 0.05). Ultrastructure analysis of cryopreserved sperm showed structural damage to the sperm plasma membrane, nuclear membrane, and tail. However, compared to the control, these structural changes were reduced upon the addition of RhoA recombinant protein to the cryoprotective fluid (P < 0.05). Western blotting revealed that the expression of Rho/RhoA-associated kinase and p-cofilin was increased, and cofilin expression was decreased after sperm cryopreservation with recombinant RhoA protein. Treatment with Y-27632, a ROCK antagonist, suppressed ROCK and p-cofilin expression and decreased semen quality, acrosome integrity, and ultrastructure integrity. In summary, we have demonstrated a cryoprotective effect in spermatozoa involving the Rho/ROCK pathway during freeze-thawing. Furthermore, the addition of 0.5 μg/mL RhoA recombinant protein to the cryoprotective fluid improved rooster semen quality and subcellular structural homeostasis after freeze-thawing via the Rho/ROCK pathway. This pathway may regulate the dynamic reorganization of the actin cytoskeleton by regulating the cofilin phosphorylation.