Pterygium Tissues Research Articles

Expression of Vitamin D Receptor and Vitamin D Receptor Gene Polymorphisms (BsmI, FokI, and TaqI) in Patients with Pterygium.

This study aimed to determine the role of vitamin D receptor in the pathogenesis of pterygium. The vitamin D receptor eexpression levels in pterygium tissue, blood vitamin D levels, and frequency of selected vitamin D receptor gene polymorphisms (BsmI, FokI, and TaqI) were compared between patients with pterygium and healthy participants. The study included patients with pterygiumeee (n=50) and healthy volunteers (n=50). The serum vitamin D levels were measured for both groups. Immunohistochemical staining for vitamin D receptor ewas performed on sections obtained from the pterygium and adjacent healthy conjunctival tissues of the same individuals. The genomic existence of vitamin D receptor epolymorphisms (BsmI, FokI, and TaqI) were analyzed in DNA obtained from venous blood of participants using polymerase chain reaction and restriction fragment length polymorphism methods. There was no difference found between the serum vitamin D levels of patients with pterygium and healthy controls. However, tissue expression of vitamin D receptor was higher in the pterygium endothelial cells of micro-vessels (p=0.002), subepithelial stromal (p=0.04), and intravascular inflammatory cells (p=0.0001), in comparison with the adjacent healthy conjunctival tissue. Moreover, while the BBtt haplotype was 2-fold higher, the bbTt haplotype was 2.5-fold lower, and the BbTT haplotype was 2.25-fold lower in the control group than in the pterygium group (p<0.001). Vitamin D serum levels did not differ between the healthy and pterygium groups. Vitamin D receptor expression was increased in the pterygium tissue versus the adjacent healthy tissue. However, vitamin D receptor polymorphism analysis in patients with pterygium did not reveal any significant difference in BsmI, FokI, or TaqI polymorphisms in comparison with the healthy volunteers.

The Inhibitory Effect of Capparis Ovata Polysaccharides on Cultured Pterygium Fibroblasts.

Objectives:Pterygium recurrence after removal surgery is an important problem. Polysaccharides obtained from Capparis species have been shown to possess various biological properties, including anti-tumor activity. This study was an investigation of the effect of Capparis ovata polysaccharides on cultured pterygium fibroblasts and a comparison with the effects of mitomycin C (MMC).Methods:Pterygium tissue samples were obtained during excision surgery from 3 patients with primary pterygium, and fibroblasts were isolated. Pterygium fibroblast cultures and L929 cell cultures were treated with different concentrations of MMC and Capparis ovata polysaccharides. Cell proliferation and migration were evaluated.Results:An MTT assay revealed that cell viability decreased with increasing concentrations of Capparis ovata polysaccharides in both cell types. MMC also inhibited the proliferation of both cell types. A scratch-wound assay indicated that both Capparis ovata polysaccharides and MMC molecules reduced proliferation and migration in the pterygium fibroblasts and L929 cells.Conclusion:The in vitro Capparis ovata polysaccharide inhibition of proliferation and migration of pterygium fibroblasts was similar to that of MMC. The results of this study suggested that Capparis ovata polysaccharides may be a valuable candidate drug to treat pterygium.

Polymorphisms of CYP1A1 Genes and Its Correlation with Clinical Variant of Pterygium

&#x0D; Background and Objective: CYP1A1 gene, which has role in carcinogenic metabolisms, is also detected in pterygium tissue. The aim of the study is to determine the polymorphisms of CYP1A1 m2 (rs1048943) and m4 (rs1799814) gene and its correlation with clinical variant of the pterygium.&#x0D; Methods: DNA isolation was performed from blood sample of 80 pterygium patients consisting of 40 inflammatory and 40 non-inflammatory pterygium. Genotyping of rs1048943 SNP AG (m2) in the CYP1A1 gene was performed using Alel Specific Polymerase Chain reaction (AS-PCR) and rs1048943) SNP Genotyping was performed using PCR. Polymorphism results are characterized as wild type (AA), mutant homozygote (GG), and mutant heterozygote (AG).&#x0D; Results: CYP1A1 m2 and m4 gene polymorphism consist of wild type (AA), mutant homozygote (GG), and mutant heterozygote (AG). Both CYP1A1 m2 and m4 genes polymorphism of both groups of inflammatory and non-inflammatory pterygium was mostly consist of wild type polymorphism, followed by the mutant heterozygote polymorphism. The wild type polymorphism was found to be higher in inflammatory pterygium, meanwhile the mutant heterozygote was found to be higher in non-inflammatory pterygium.&#x0D; Conclusion: There were differences in CYP1A1 m2 and m4 gene polymorphism in both pterygium group, but none has been shown to be statistically associated with the clinical variant of the pterygium.

Activation of LncRNA FOXD2-AS1 by H3K27 acetylation regulates VEGF-A expression by sponging miR-205-5p in recurrent pterygium.

LncRNA FOXD2‐AS1 is abnormally expressed in many diseases. However, the molecular mechanisms whereby FOXD2‐AS1 is involved in recurrent pterygium remain unknown. Here, qRT‐PCR was performed to quantify FOXD2‐AS1 expression, while CCK‐8, flow cytometer and neoplasm xenograft assays were used to investigate its function. Dual‐luciferase reporter, RIP and RNA pull‐down assays were conducted to address the relationship between FOXD2‐AS1, miR‐205‐5p and VEGF‐A, while ChIP assays were used to detect H3K27 acetylation at the FOXD2‐AS1 promoter. FOXD2‐AS1 expression was up‐regulated in recurrent pterygium tissues. Moreover, a high FOXD2‐AS1 expression was associated with advanced stages, increased microvessel density and shorter recurrent‐free survival. In addition, ROC analysis showed that FOXD2‐AS1 is a valid predictor of recurrent pterygium. Furthermore, we show that FOXD2‐AS1 induced proliferation and inhibited apoptosis in a cell line derived from recurrent pterygia (HPF‐R) at least partially through the regulation of the miR‐205‐VEGF pathway. In addition, the up‐regulation of FOXD2‐AS1 was attributed to the H3K27 acetylation at the promoter region. In conclusion, FOXD2‐AS1 is activated via its H3K27 acetylation and regulates VEGF‐A expression by sponging miR‐205‐5p in recurrent pterygium. Our results may provide a basis for the development of new therapeutic targets and biomarkers for recurrent pterygium.

PTERJİUM CERRAHİSİ İÇİN NEDEN BEKLENİR?

AMAÇ: Pterjium cerrahisi yapılan hastalarda ameliyat zamanını etkileyen faktörleri bulmak ve alınabilecek önlemleri tespit etmek amaçlanmıştır.GEREÇ VE YÖNTEM: Ocak 2014-Şubat 2017 arası kliniğimizde pterjium nedeniyle cerrahi yapılan 53 hastanın 53 gözü çalışmaya alındı. Hastaların bilgileri, ameliyatı bekleme sebepleri ve cerrahi öyküsü sorgulandı. Hastaların cevaplarına göre gruplandırma yapıldı: Hastalığını bildiği halde çok fazla rahatsızlık duymamak (grup 1), hastalığının farkında olmamak (grup 2), ameliyat olmak için pterjiumun biraz daha ilerlemesini beklemek (grup 3), pterjium cerrahisi daha önce geçirip yine tekrarlamasından endişe etmek (grup 4) ve ameliyattan korkmak (grup 5).BULGULAR: En çok karşılaşılan pterjium ameliyatı geciktirme nedeni; hastalığını bildiği halde çok fazla rahatsızlık duymamak idi. İkinci sırada ise, ameliyat olmaktan korkmak olduğu tespit edildi. Cerrahiyi geciktirme nedenleri dağılımı şu şekilde idi: 1.Grup 23 (%43.4), 2.grup 8 (%15.09), 3.grup 8 (%15.09), 4.grup 4 (%7.55), 5.grup 10 (%18.87) hasta.SONUÇ: Pterjiumda hasta kaynaklı ameliyat zamanı gecikmesinin ameliyat başarısını ve sonuçlarını etkileyebileceği, yapılacak ameliyatla ilgili hastaların bilgilendirilmesi, hastaların endişelerinin giderilmesinde psikolojik-sosyal destek verilmesi ameliyat olma zamanında gecikmeleri önleyebilir.

Sutureless Glueless Conjunctival Autograft for Primary Pterygium Surgery

Pterygium occurs predominantly on the nasal limbus, although temporal pterygium rarely occurs in isolation. Double-head pterygium, that is nasal and temporal pterygia in the same eye is rare. In studies by Dolezalova, the incidence was found to be (2.5%). UV light may produce damage to the cellular DNA, RNA, and extracellular matrix and may induce expression of cytokines and growth factors important in the development of pterygium. It was described that the pterygium was associated with human papilloma virus (HPV) with the predisposing factor as dry heat and it also behaves as a neoplasm revealed by the presence of 8- hydroxydeoxyguanosine in the pterygial tissue that suggested the role of oxidative stress as a key factor in its causation. Conjunctival autografting after pterygium excision seems to be the best method, giving both long-term safety and effectiveness in reducing the recurrence rate (2% – 39%). The conjunctival autograft is attached with sutures, which may be associated with complicated surgical techniques, prolonged operating time, prolonged postoperative patient discomfort, and suture-related complications. Scanty data exists evaluating success of sutureless and glue free limbal conjunctival autograft for the management of primary pterygium. The results were very encouraging as they suggested that sutureless and glue free limbal conjunctival autografting following pterygium excision is a simple, safe, effective, without much complications and economical option for the management of primary pterygium. The aim of the current study was to evaluate the suture less glueless conjunctival autograft for primary pterygium surgery as regard technique, complications and success rate.

Relative quantification of human β‑defensins gene expression in pterygium and normal conjunctiva samples.

The human ocular surface produces highly conserved cationic peptides. Human β‑defensins (HBDs) serve an important role in innate and adaptive immunity. They are primarily expressed in epithelial cells in response to infection and provide the first line of defence against invading microbes. Defensinβ1 (DEFB1) is constitutively expressed and regulated by inflammatory mediators including interferon‑γ, lipopolysaccharide and peptidoglycans. DEFB4A is locally induced in response to microbial infection while DEFB109 is induced via Toll‑like receptor2. The present study examined the expression of the HBD DEFB1, DEFB4A and DEFB109 genes in pterygium. The pterygium tissues and normal conjunctiva samples were obtained from 18patients undergoing pterygium surgery. The reverse transcription‑quantitative polymerase chain reaction method was employed to determine the expression of DEFB1, DEFB4A and DEFB109 genes. The results revealed that the expression of DEFB1 and DEFB4A was significantly higher and upregulated in pterygium samples when compared with normal conjunctiva samples from each patient (P<0.05), while the expression of DEFB109 was observed to be lower in pterygium samples when compared with normal samples from the same patient. Previous studies have revealed that DEFB1 and DEFB4A genes are present in low concentrations inside the human eye, and they are upregulated during the maturation of keratinocytes, suggesting a possible role in cell differentiation. The DEFB109 gene is present in higher concentrations inside the human eye, though it is newly discovered. It has also been reported that DEFB1 may be involved in carcinogenesis epithelial tumours. Collectively, the current data suggests that HBDs may serve a crucial role in the pathogenesis and development of pterygia, and thus may be considered as novel molecular targets in understanding pterygia development.

Histamine-1 Receptors Expression in Primary Pterygium Tissue is Higher than Normal Conjunctival Tissue

BACKGROUND: Pterygium is an eye disease with multifactorial etiopathogenesis. Molecular factors such as cell proliferation and inflammatory mediators are associated with increased calcium mobilization and activation of nuclear factor kβ mediated by histamine-1 receptors (H1R).&#x0D; AIM: This study aims to determine whether the expression of H1R primary pterygium tissue is higher than normal conjunctival tissue and the expression of H1R based on pterygium grades.&#x0D; METHODS: This study was an analytic observational study with a case-control study approach at Sanglah General Hospital, Bali Mandara Eye Hospital, and Mangusada Hospital. The study was conducted from November 2017 to April 2018. The pterygium and conjunctival tissues obtained from 28 subjects in the same eye and examined for H1R expression by immunohistochemistry.&#x0D; RESULT: The results of this study obtained 64.3% of women with a mean age of 54.2 ± 7.8 years. There was no difference in mean H1R expression between pterygium grades in the final score (P = 0.759). There was a mean difference of H1R between primary pterygium (42.50) and normal conjunctival tissue (14.50) with P &lt;0.001. Only tissue types affected the expression of H1R in the final score (B = 4.893; 95% CI 4.363-5.423; P &lt;0.001).&#x0D; CONCLUSION: It was concluded that the expression of H1R primary pterygium tissue was higher in primary pterygium than normal conjunctival tissue.

Protective Role of Glutathione and Nitric Oxide Production in the Pathogenesis of Pterygium.

Objective In the pathogenesis of pterygium, the protective role of glutathione and nitric oxide production is unclear. These are important factors for homeostasis in the redox state of cells. The aim of this study was to determine the levels of these and related parameters in pterygium tissue. Patients and Methods. The study sample consisted of 120 patients diagnosed with primary or recurrent pterygium. Five groups of tissue samples were examined: control, primary pterygium, recurrent pterygium, and two groups of primary pterygium given a one-month NAC presurgery treatment (topical or systemic). The levels of endothelial nitric oxide synthase (eNOS), nitric oxide (NO), 3-nitrotyrosine (3NT), reduced and oxidized glutathione (GSH and GSSG), and catalase (CAT) were evaluated in tissue homogenates. Results Compared with the control, decreased levels of eNOS, NO, and 3-nitrotyrosine as well as the degree of oxidation of GSH (GSSG%) were observed in primary and recurrent pterygium. 3-Nitrotyrosine and GSSG% were reduced in the other pterygium groups. GSH and CAT were enhanced in recurrent pterygium and systemic-treated primary pterygium but were unchanged for topical-treated primary pterygium. There was a strong positive correlation of eNOS with NO and 3NT, GSSG% with NO and 3NT, and GSH with GSSG and CAT. Women showed a higher level of GSH and catalase in primary pterygium, whereas a lower level of GSH and a higher level of NO in recurrent pterygium. Conclusion The results are congruent with the following proposed sequence of events leading to a protective response of the organism during the pathogenesis of primary pterygium: a decreased level of eNOS provokes a decline in the level of NO in pterygium tissue, which then leads to reduced S-nitrosylation of GSH or other thiols and possibly to the modulation of the intracellular level of GSH through synthesis and/or mobilization from other tissues.

Relative gene expression analysis of human pterygium tissues and UV radiation-evoked gene expression patterns in corneal and conjunctival cells

A sight threatening, pterygium is a common ocular surface disorders identified by fibrovascular growth of the cornea and induced by variety of stress factors, like ultraviolet (UV) exposure. However, the genes involved in the etiopathogenesis of this disease is not well studied. Herein, we identified the gene expression pattern of pterygium and examined the expression of pterygium-related genes in UV-B-induced human primary cultured corneal epithelial cells (HCEpCs), telomerase immortalized human corneal epithelial (hTCEpi), primary conjunctival fibroblast (HConFs) and primary pterygium fibroblast cells (HPFCs). A careful analysis revealed that the expression of 10 genes was significantly modulated (by > 10-fold). Keratin 24 (KRT24) and matrix metalloproteinase 9 (MMP-9) were dramatically upregulated by 49.446- and 24.214-fold, respectively. Intriguingly, UV-B exposure (50 J/m2) induced the upregulation of the expressions of MMP-9 in corneal epithelial cells such as HCEpCs and hTCEpi. Furthermore, UV-B exposure (100 and/or 200 J/m2) induced the upregulation of the expressions of MMP-9 in fibroblast such as HConFs and HPFCs. The exposure of HCEpCs to 100 and 200 J/m2 UV-B induced significant expressions of KRT24 mRNA. Nevertheless, no expression of KRT24 mRNA was detected in HConFs and HPFCs. The findings provide evidence that the progression of pterygium may involve the modulation of extracellular matrix-related genes and vasculature development and the up-regulation of KRT24 and MMP-9 by UV stress. UV radiation may promote the modulation of these pterygium-related genes and induce the initiation and progression of human pterygium.

Analysis of CRABP2 and FABP5 genes in primary and recurrent pterygium tissues.

The etiology of pterygium remains unclear, but ultraviolet (UV) radiation is generally considered to be major risk factor. Pterygium has similarity features with many cancers, including inflammation, invasion, cell proliferation, anti-apoptosis, angiogenesis and recurrence after resection. Retinoic acid via cellular retinoic acid binding protein 2 (CRABP2) is involved in cell cycle arrest, apoptosis and differentiation, while it via fatty acid binding protein 5 (FABP5) is involved in survival, cell proliferation and angiogenesis, which pathway gets activated depends on the CRABP2/FABP5 ratio. Alterations of retinoid signaling were found in many cancer types. The deregulated retinoid signaling may also contribute to the development and/or recurrence of pterygium. The aim of our study was to determine mRNA and protein expressions of CRABP2 and FABP5 and ratio of CRABP2/FABP5 in primer and recurrent pterygium tissues. Pterygia tissues were collected from 30 eyes of 30 patients undergoing pterygium excision. CRABP2 and FABP5 mRNA and protein expression were assessed using Real-time PCR and Western blotting through examination of excised specimens from pterygium and conjunctiva tissues. The ratio of CRABP2/FABP5 gene expression was not altered when primary pterygium tissues compared normal conjunctival tissues (1.00-fold change). Whereas the ratio of CRABP2/ FABP5 gene expression was decreased when recurrent pterygium tissues compared normal conjunctival tissues (0.81-fold change). Understanding etiopathogenesis of pterygium may aid in the find of more promising treatments to prevent pterygium in earlier stages.

Bcl-2, p53, and Ki-67 expression in pterygium and normal conjunctiva and their relationship with pterygium recurrence.

Pterygium is a common lesion of the ocular surface, and its etiology and pathogenesis are still uncertain. This study aimed to investigate the role of apoptosis and proliferation in pterygium formation and recurrence. In this study, p53, Bcl-2, and Ki-67 expression levels were evaluated in primary pterygium (n = 35) and recurrent pterygium (n = 32) tissue samples and compared with normal conjunctiva (n = 30) tissue samples. In addition, recurrent pterygiums were divided into three groups based on recurrence time, and their p53, Bcl-2, and Ki-67 expression levels were compared. The results show that p53, Bcl-2, and Ki-67 expression levels were significantly higher in the pterygium tissue samples as compared to the control group (p < 0.001, p < 0.001, and p < 0.001, respectively). When primary and recurrent pterygium tissues were compared, bcl-2 expression was higher in recurrent pterygium tissue samples (p = 0.003). However, when Ki-67 and p53 expression levels were evaluated, no significant difference was found between primary and recurrent pterygium (p = 0.215, p = 0.321, respectively). Also, p53 and Ki-67 expression were correlated in pterygium tissue samples, and Bcl-2 expression was significantly higher in pterygium that recurrence in the first 6 months after surgery. There was no difference between groups 1, 2, and 3 in terms of p53 and Ki-67 expression. Antiapoptotic mechanisms and proliferation play an important role in the etiopathogenesis of pterygium. Furthermore, Bcl-2 expression may be important in pterygium recurrence.

Inhibitory Effect of Valsartan on Pterygium Fibroblasts.

Angiotensin receptor blockers (ARBs) were shown to have antifibrotic properties in ocular and systemic diseases. In this study, our aim was to investigate the effect of an angiotensin receptor blocker, valsartan, on pterygium fibroblasts and compare this effect with that of mitomycin C (MMC). Pterygium tissue samples were obtained from 3 patients during surgical excision. Primary cultured pterygium fibroblasts and L929 cell cultures were treated with different concentrations of MMC and valsartan. The cell viability decreased with increasing concentrations of valsartan at 48 hours for both cell types. MMC inhibited the proliferation of both cell types at 48 hours. Both agents significantly decreased the cell migration of the 2 cell types, although it was more prominent in the MMC-treated group. Valsartan inhibited the proliferation and migration of pterygium fibroblasts. The known favorable safety profile of these drugs and the results of this study showing inhibitory effect on pterygium fibroblasts make valsartan a potential therapeutic agent for pterygium treatment.

Role of oxidative stress and vascular endothelial growth factor expression in pterygium pathogenesis and prevention of pterygium recurrence after surgical excision.

To assess the roles of oxidative stress and vascular endothelial growth factor (VEGF) in pterygium pathogenesis and prevention of pterygium recurrence after surgical excision. Surgically removed pterygium tissue from 35 pterygium patients and normal conjunctival samples from 15 patients matched for age and sex (used as controls) constituted the study samples. The conjunctival samples were preserved at - 80 °C until analysis. Catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH) and total antioxidant (TAO) enzymatic activity and the levels of nitric oxide (NO), malondialdehyde (MDA) and VEGF were studied in both groups. To evaluate the recurrence rate after surgical excision, the pterygium patients were further subdivided into three groups according to the adjuvant therapy used to prevent recurrence. Group 1 consisted of 10 patients who were treated with 0.2 mg mitomycin-c (MMC) for 2 min. Group 2 consisted of 12 patients treated with subconjunctival bevacizumab injection after surgical removal of the pterygium. Group 3 consisted of 13 patients who underwent combined treatment with 0.2 mg of MMC for 2 min and subconjunctival bevacizumab injection. The follow-up of patients in the three groups ranged from 7 to 15 months. The activities of CAT, SOD, GSH and TAO were significantly lower in pterygium samples than in normal conjunctival samples (p < 0.0001 each). The levels of MDA (p = 0.046), NO (p < 0.0001) and VEGF (p < 0.0001) were significantly higher in pterygium patients than in controls. The lowest recurrence rate after surgical excision was that of the third group. Oxidative stress and VEGF could play a role in the pathogenesis of pterygium as indicated by decreased antioxidant enzymatic activity and increased levels of VEGF in the pterygium tissue and the role of MMC and anti-VEGF therapy in decreasing the recurrence rate after surgical excision.

Expression of SARS-CoV-2 receptor ACE2 and TMPRSS2 in human primary conjunctival and pterygium cell lines and in mouse cornea.

PurposeTo determine the expressions of SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine protease (TMPRSS2) genes in human and mouse ocular cells and comparison to other tissue cells.MethodsHuman conjunctiva and primary pterygium tissues were collected from pterygium patients who underwent surgery. The expression of ACE2 and TMPRSS2 genes was determined in human primary conjunctival and pterygium cells, human ocular and other tissue cell lines, mesenchymal stem cells as well as mouse ocular and other tissues by reverse transcription-polymerase chain reaction (RT-PCR) and SYBR green PCR.ResultsRT-PCR analysis showed consistent expression by 2 ACE2 gene primers in 2 out of 3 human conjunctival cells and pterygium cell lines. Expression by 2 TMPRSS2 gene primers could only be found in 1 out of 3 pterygium cell lines, but not in any conjunctival cells. Compared with the lung A549 cells, similar expression was noted in conjunctival and pterygium cells. In addition, mouse cornea had comparable expression of Tmprss2 gene and lower but prominent Ace2 gene expression compared with the lung tissue.ConclusionConsidering the necessity of both ACE2 and TMPRSS2 for SARS-CoV-2 infection, our results suggest that conjunctiva would be less likely to be infected by SARS-CoV-2, whereas pterygium possesses some possibility of SARS-CoV-2 infection. With high and consistent expression of Ace2 and Tmprss2 in cornea, cornea rather than conjunctiva has higher potential to be infected by SARS-CoV-2. Precaution is necessary to prevent possible SARS-CoV-2 infection through ocular surface in clinical practice.

Transcriptional profiling to identify the key genes and pathways of pterygium

PurposePterygium results from a variety of biological pathways that are involved in the formation of ocular surface diseases. However, the exact pathogenesis of pterygium is still unclear. Our study focused on gene expression profiles to better understand the potential mechanisms of pterygium.MethodsRNA sequencing experiments were performed on clinical pterygium tissues and normal conjunctival tissues. To identify the hub genes for the development of pterygium, we further conducted weighted gene co-expression network analysis (WGCNA). qRT-PCR was utilized to validate the dysregulation of the most significant differentially expressed genes (DEGs) and key hub genes in the independent subjects.ResultsA total of 339 DEGs (P-adjusted < 0.05 and log2 fold change [log2FC] ≥ 1.0) were obtained that reached statistical significance with p-values < 0.05. Among them, 200 DEGs were upregulated; these genes were mainly associated with the extracellular matrix and with cell adhesion or migration. In contrast, the 139 downregulated genes were enriched for endocrine and inflammation pathways. With regard to WGCNA, five modules were assigned based on the DEG profiles, and the biological functions of each module were verified with previously published GO terms. The functions included ECM-receptor interactions, the PI3K-Akt signalling pathway and an endoplasmic reticulum (ER)-related pathway. The five hub genes with the highest connectivity in each module and the five most significant DEGs showed dysregulated expression in the independent cohort samples.ConclusionsRNA sequencing and WGCNA provided novel insights into the potential regulatory mechanisms of pterygium. The identified DEGs and hub genes, which were classified into two groups according to different functions or signalings, may provide important references for further research on the molecular biology of pterygium.

Analysis of WWOX gene expression and protein levels in pterygium.

Pterygium, a degenerative and hyperplastic lesion, has premalignant properties as a tumor analog. WWOX is a tumor suppressor gene and involved in many signal pathways, such as cell proliferation, embryonic development, metabolism and apoptosis. In many cancers, the loss of WWOX or the presence of abnormal transcripts indicates the tumor suppressor activity of WWOX. In this study, it was aimed to determine WWOX gene expression and protein levels in pterygium which may be a tumor analog. For this purpose, the WWOX gene expression change in 27 pterygium tissue was investigated by real-time PCR method, and the change in WWOX protein was investigated using the Western blot method. According to our results, it was found that the expression and protein levels of WWOX gene in pterygium tissue decreased significantly compared to control tissue (p < 0.05). This information indicates that a decrease in expression and protein level in pterygium tissue of WWOX, a tumor suppressor gene, supports claims that pterygium may be a cancer analog tissue.

Quantification of pterygium fibroconnective components utilizing freeze-dried method

Introduction: To propose an objective method of quantifying pterygium fibroconnective components utilizing freeze-dried method. Methods: 60 primary pterygium were excised using controlled partial avulsion technique performed by a single surgeon (KMK), and divided into two groups: formalin-fixed (n=30) and fresh (n=30). Initially, each sterile container weight was measured and 5ml of 5% buffered formaldehyde were filled and stored for 1 week for formalin-fixed group while, 5ml distilled water were filled for fresh pterygium group. Each container was pre-frozen for 12 hours prior to freeze-dried (-80ºC for 24 hours). The final product known as fibroconnective tissue, then weighted as dry weight. Comparative analysis of wet and dry weight, and percentage of fibroconnective components between groups were performed via an independent t-test. Results: The overall mean and SD for formalin-fixed and fresh pterygium wet weight were 253.33 ± 82.17 μg and 255.17 ± 63.52 μg, and dry weight were 184.92 ± 84.31 μg and 179.54 ± 72.85 μg respectively. In terms of percentage of fibroconnective components, formalin-fixed group revealed slightly higher percentage compared to fresh pterygium tissue with 69.39 ± 13.29 % and 67.75 ± 13.27 % respectively. The difference in pterygium dry weight, between formalin-fixed and fresh pterygium tissue was statistically insignificant (p=0.792). Conclusions: The freeze-dried method can be used to quantify the fibroconnective component (dry weight) of pterygium fibro vascular tissue. Both methods (formalin-fixed and freeze-dried) are reliable in producing results. This is proven as there is no statistical significance between the two methods.

Expression and clinical significance of endostatin and angiostatin in pterygium

Objective To investigate the expression and clinical significance of endostatin (ES) and angiostatin (AS) in pterygium. Methods From January 2016 to December 2018, 60 cases (60 eyes) of pterygium tissue and 60 cases (60 eyes) of normal human conjunctival tissue were selected from the eye surgery of Traditional Chinese Medicine Hospital of Yiwu.HE staining was used to observe the morphological changes of pterygium and normal conjunctival tissue.Western blot was used to measure ES and AS protein levels in the tissues of pterygium group and control group. Results HE staining showed that in the normal bulbar conjunctival tissue, the stromal layer was connective tissue and the epithelial layer was columnar epithelium; in the pterygium, the basal layer had a large number of new blood vessels, fibroblasts, collagen fibers, and inflammatory cells infiltrated around the blood vessels; the epithelium showed different degrees of hyperplasia.The protein levels of ES and AS in pterygium tissues[(0.35±0.12), (0.62±0.17)] were higher than those in the control group [(0.13±0.08), (0.16±0.09)](t=11.816, 18.524, P=0.000, 0.000). The protein levels of ES and AS in the pterygium tissues of the recurrent group [(0.63±0.15), (0.87±0.21)] were higher than those in the initial group [(0.22±0.11), (0.45±0.16)](t=17.073, 12.323, P=0.000, 0.000). There was positive correlation between ES and AS in pterygium (r=0.571, P=0.000). Conclusion The levels of ES and AS in pterygium tissue are increased, and ES and AS may be involved in the occurrence and recurrence of pterygium. Key words: Pterygium; Inhibins; Angiostatins; Endothelial cells; Recurrence

Clinical demographics of pterygium excision and prevalence of conjunctival intraepithelial neoplasia: a 15-year review.

To find clinical demographics of pterygium surgery and prevalence of conjunctival intraepithelial neoplasia (CIN) in pterygium specimen. This is a retrospective, institutional study. The records of patients who had received pterygium excision from 2000 to 2014 were reviewed. Patients after complete ophthalmic "examinations", surgical procedures, and pathological reports were enrolled. Surgical procedures, pathology, external eye photography, prevalence of CIN in specimen, and demographic data were described. Of 1787 pterygium cases, 928 were male and 859 were female. The mean age was 65.19 ± 14.21years. Of these 1787 cases, 1435 (80.3%) cases had primary pterygium excision, while the others (n = 352; 19.7%) had pterygium excision for recurrence. Four cases presented CIN within pterygium tissue (0.22%). The mean age of pterygium patients with CIN was 57.75 ± 7.80years. In stratified data, our patients who received primary and secondary pterygium excision were found prevalent in the eighth (28.2%) and seventh (26.1%) decade, respectively. Twelve percent of patients who underwent secondary pterygium excision had a recurrence and required another surgery. Patients requiring amniotic membrane transplantation (AMT) during primary pterygium excision were significantly younger (median, 58years) than those (median, 67years) without the assistance of AMT (p < 0.001). Similarly, AMT was utilized in younger patients (median, 56years) during secondary pterygium excision, compared to those without AMT (median, 64years) (p = 0.001). CIN combined with pterygium is very rare. However, the possibility of the development of ocular surface squamous neoplasia in pterygium tissue should not be ignored. Meticulous pathological investigation of the surgical samples is important.