conjunctival epithelial cells
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2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiangzhe Li ◽  
Boram Kang ◽  
Youngsub Eom ◽  
Jingxiang Zhong ◽  
Hyung Keun Lee ◽  
...  

AbstractThe impact of particulate matter (PM) on ocular surface health has attracted increased attention in recent years. Previous studies have reported that differences in the chemical composition of PM can affect the toxicological response. However, available information on the toxic effects of chemical components of PM on the ocular surface is insufficient. In this paper, we aimed to investigate the toxicity effects of chemical components of PM on the ocular surface, focusing on the effects of four different types of nanoparticles (NPs) in human corneal epithelial cells (HCECs) and human conjunctival epithelial cells (HCjECs), which include titanium dioxide (TiO2), carbon black (CB), zinc dioxide (ZnO), and silicon dioxide (SiO2). We found that the in vitro cytotoxic effects of CB, ZnO, and SiO2 NPs are dependent on particle properties and cell type as well as the exposure concentration and time. Here, the order of increasing toxicity was SiO2 → CB → ZnO, while TiO2 demonstrated no toxicity. Moreover, toxic effects appearing more severe in HCECs than HCjECs. Reactive oxygen species (ROS)-mediated oxidative stress plays a key role in the toxicity of these three NPs in HCECs and HCjECs, leading to apoptosis and mitochondrial damage, which are also important contributors to aging. Sirtuin1 (SIRT1) as an NAD+-dependent protein deacetylase that seems to play a potential protective role in this process. These findings implied that ROS and/or SIRT1 may become a potential target of clinical treatment of PM- or NP-related ocular surface diseases.


2021 ◽  
Author(s):  
Majlinda Lako ◽  
Robert M Jackson ◽  
Catherine F Hatton ◽  
Jarmila S Spegarova ◽  
Maria Georgiou ◽  
...  

Although tropism of SARS-CoV-2 for respiratory tract epithelial cells is well established, an open question is whether the conjunctival epithelium is also a target for SARS-CoV-2. Conjunctival epithelial cells, which express viral entry receptors ACE2 and TMPRSS2, constitute the largest exposed epithelium of the ocular surface tissue, and may represent a relevant viral entry route. To address this question, we generated an organotypic air-liquid-interface model of conjunctival epithelium, composed of progenitor, basal and superficial epithelial cells and fibroblasts, which could be maintained successfully up to day 75 of differentiation. Using single-cell RNA Seq, with complementary imaging and virological assays, we observed that while all conjunctival cell types were permissive to SARS-CoV-2 genome expression, a productive infection did not ensue. The early innate immune response to SARS-CoV-2 infection in conjunctival cells was characterised by a robust autocrine and paracrine NF-Kβ activity, without activation of antiviral interferon signalling. Collectively, these data enrich our understanding of SARS-CoV-2 infection at the human ocular surface, with potential implications for the design of preventive strategies and conjunctival transplants.


Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 951
Author(s):  
Michelle Bressan ◽  
Antonella Rampazzo ◽  
Jasmin Kuratli ◽  
Hanna Marti ◽  
Theresa Pesch ◽  
...  

Chlamydia (C.) felis primarily replicates in feline conjunctival epithelial cells and is an important cause of conjunctivitis in cats. Data on C. felis infection rates in stray cats in Switzerland has been missing so far. We performed a qPCR-based Chlamydiaceae-screening on 565 conjunctival and 387 rectal samples from 309 stray and 86 pet cats followed by Chlamydia species identification and C. felis typing using the gene pmp9, which encodes a polymorphic membrane protein. Overall, 19.1% of the stray and 11.6% of the pet cats were Chlamydiaceae-positive with significantly higher rates in cats displaying signs of conjunctivitis (37.1%) compared to healthy animals (6.9%). Rectal shedding of Chlamydiaceae occurred in 25.0% of infected cats and was mostly associated with concurrent ocular positivity (87.5%). In 92.2% of positive conjunctival and rectal samples, the Chlamydia species was identified as C. felis and in 2.6% as C. abortus. The C. felis pmp9 gene was very conserved in the sampled population with only one single-nucleotide polymorphism (SNP) in one conjunctival sample. In conclusion, C. felis strains are circulating in Swiss cats, are associated with conjunctivitis, have a low pmp9 genetic variability, and are rectally shed in about 16% of positive cases.


Author(s):  
Michal Sosnovsky ◽  
Uri Zaretsky ◽  
Ariel J. Jaffa ◽  
Dan Grisaru ◽  
David Elad ◽  
...  

Medicina ◽  
2021 ◽  
Vol 57 (4) ◽  
pp. 369
Author(s):  
Sang Beom Han ◽  
Farah Nur Ilyana Mohd Ibrahim ◽  
Yu-Chi Liu ◽  
Jodhbir S. Mehta

Background and objectives: the aim of this study was to analyze the efficacy of a modified “amnion-assisted conjunctival epithelial redirection (ACER)” technique for the treatment of partial limbal stem cell deficiency (LSCD). Materials and methods: the medical records of three patients with partial LSCD who underwent corneal surface reconstruction with modified ACER following superficial keratectomy were retrospectively studied. Briefly, in this technique, an inner amniotic membrane (AM) layer was applied on the corneal surface to promote corneal re-epithelialization. The outer AM layer was applied as a barrier to prevent the invasion of conjunctival epithelial cells into the cornea before the corneal surface was completely covered by corneal epithelial cells derived from the remaining intact limbal stem cells. Results: in all three cases, the outer AM layer successfully kept the conjunctival epithelium away from the corneal surface and prevented an admixture of conjunctival epithelial cells with corneal epithelial cells. In all three patients, the cornea was completely re-epithelized with epithelial cells derived from the remaining healthy limbal stem cells, and a clear visual axis was maintained without recurrence for a mean follow-up period of 37.3 ± 8.6 months. Conclusions: the preliminary results suggest that modified ACER appears to be a viable option for patients with partial LSCD.


2021 ◽  
Vol 20 ◽  
pp. 195-198
Author(s):  
Katerina Jirsova ◽  
Viera Vesela ◽  
Pavlina Skalicka ◽  
Eva Ruzickova ◽  
Johana Glezgova ◽  
...  

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 318
Author(s):  
Lucy A. Bosworth ◽  
Kyle G. Doherty ◽  
James D. Hsuan ◽  
Samuel P. Cray ◽  
Raechelle A. D’Sa ◽  
...  

The conjunctiva, an under-researched yet incredibly important tissue, plays key roles in providing protection to the eye and maintaining homeostasis of its ocular surface. Multiple diseases can impair conjunctival function leading to severe consequences that require surgical intervention. Small conjunctival defects can be repaired relatively easily, but larger defects rely on tissue grafts which generally do not provide adequate healing. A tissue engineering approach involving a biomaterial substrate capable of supporting a stratified epithelium with embedded, mucin-secreting goblet cells offers a potential solution. As a first step, this study aimed to induce stratification of human conjunctival epithelial cells cultured on electrospun scaffolds composed from poly(ε-caprolactone) (PCL) and decellularised tissue matrix (small intestinal submucosa (SIS) or urinary bladder matrix (UBM)) and held at the air/liquid interface. Stratification, up to 5 cell layers, occurred more frequently on scaffolds containing PCL + UBM. Incorporation of these decellularised tissue matrices also impacted material properties, with significant changes occurring to their fibre diameter, tensile properties, and chemical composition throughout the scaffold structure compared to PCL alone. These matrix containing scaffolds warrant further long-term investigation as a potential advanced therapy medicinal product for conjunctiva repair and regeneration.


2020 ◽  
Author(s):  
Marina Bertolin ◽  
Stefano Ferrari ◽  
Claudia Breda ◽  
Barbara Ferrari ◽  
Diego Ponzin ◽  
...  

Abstract Background. Conjunctival epithelial stem cell therapy represents a potential and valuable therapeutic option for people suffering from conjunctival disorders. We recently developed a research protocol for the ex vivo cultivation of conjunctival epithelial cells. However, manufacturing and release of any Advanced Therapy Medicinal Product (ATMP) must be designed and planned according to the Good Manufacturing Practices (GMPs) guidelines. GMPs require the development and validation of properly defined manufacturing processes, analysis methods and process validations. Our previous experience with GMP-cultured corneal epithelial stem cells for clinical application on patients with limbal stem cell deficiency led us to set up a protocol for cultivation of conjunctival cells with standards complying with the requests for clinical studies. The major challenge for cell-based products is to develop manufacturing processes while maintaining the critical quality parameters in terms of safety, identity, purity and potency.Results. The manufacturing process was re-designed in order to include all the quality control assays needed for the release of any ATMP, i.e., sterility, morphology, cell viability, dose, cell identity and impurities, potency, lack of pyrogens, mycoplasma and viral detection. Methods and acceptance values were set for all the assays. Quality control assays to evaluate safety and efficacy were also investigated.Conclusion. Here, we describe the main phases of the manufacturing process of a conjunctival stem cell-based product to use in clinical applications. Such characterization is crucial for the preparation of documents and dossiers needed by the competent authorities to start a phase I clinical study on patients with conjunctival disorders. The procedure necessary to reach the marketing authorization of such a new cell-based product is still long, but, if reliable and validated, we believe that, in the near future, patients with conjunctival disorders might have a new treatment based on transplantation of autologous cultured conjunctival epithelial stem cells.


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