Apoptosis of conjunctival epithelial cells before and after the application of autologous serum eye drops in severe dry eye disease

Autologous blood in the management of ocular surface disorders

Autologous blood therapy has emerged as a promising modality in managing ocular surface disorders. This review provides a comprehensive overview of the current literature regarding the use of autologous blood in ocular surface disorders, encompassing its physiological basis, clinical applications, techniques, challenges, and future perspectives. The ocular surface, comprising the cornea, conjunctiva, and tear film, plays a critical role in maintaining visual function, and its disruption can lead to various pathological conditions. With its rich composition of growth factors, cytokines, and other bioactive molecules, autologous blood offers therapeutic potential in promoting corneal wound healing, reducing inflammation, and improving tear film stability. Clinical studies have demonstrated the efficacy and safety of autologous blood therapy in diverse ocular surface disorders, including persistent epithelial defects, neurotrophic keratopathy, and dry eye disease. However, challenges such as variability in treatment response, adverse effects, and optimal patient selection remain areas of concern. Further research is needed to elucidate the underlying mechanisms of action, refine treatment protocols, and explore synergistic approaches with other therapeutic modalities. Despite these challenges, autologous blood therapy holds promise as a valuable adjunctive treatment option for ocular surface disorders, offering new avenues for improving patient outcomes and quality of life. This review examines the mechanisms underlying ocular surface disorders while discussing existing autologous blood-based therapies for managing these disorders. Current clinical trials are also summarized, and a comparison between autologous blood therapy and conventional eyedrops is attempted. Finally, safe techniques and protocols for autologous blood medicine are elucidated, and adverse effects and future perspectives of this novel therapy are reviewed.

Autologous serum eye drops for patients with dry eye disease: a systematic review and meta-analysis of randomized controlled trials

Background

Dry eye disease (DED) is highly prevalent worldwide, leading to increased medical costs, economic burdens on families and society, and a diminished quality of life for patients. The utilization of autologous serum eye drops (ASEDs) for the treatment of DED is progressively rising.

Objective

To further evaluate the efficacy and safety of ASEDs in the treatment of DED.

Methods

A thorough search for randomized controlled trials (RCTs) was conducted across eight databases, including PubMed, EMBASE, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang, SinoMed, and VIP. This search encompassed the inception of each database up to April 1, 2024, with a specific focus on identifying RCTs evaluating the efficacy and safety of ASEDs for the treatment of DED. Data analysis was conducted utilizing Stata 15.0 software and the Cochrane Risk of Bias Assessment Tool was utilized to appraise the literature's quality.

Results

The study encompassed 12 RCTs. In comparison to the use of artificial tears (AT), patients diagnosed with DED who utilized ASEDs displayed elevated the Schirmer test (ST) scores [WMD = 2.35, 95% CI (1.45, 3.24), p < 0.001] and tear-film breakup time (TBUT) scores [WMD = 2.83, 95% CI (2.27, 3.39), p < 0.001], decreased Corneal fluorescence staining (CFS) scores [SMD = -2.11, 95% CI (-3.07, -1.15), p < 0.001] and the Ocular Surface Disease Index (OSDI) scores [WMD = -10.54, 95% CI (-13.31, -7.77), p < 0.001], and experienced a reduced frequency of adverse events [RR = 0.36, 95% CI (0.13, 0.99), p = 0.048].

Conclusion

In this study, ASEDs had been shown to enhance tear secretion, extend tear film break-up time, mitigate corneal epithelial damage, ameliorate OSDI scores, and exhibit greater safety compared to AT.

Effects of Autologous Serum and Platelet-Rich Plasma on Human Corneal Endothelial Cell Regeneration: A Comparative Study

OBJECTIVES

To investigate the effects of autologous serum (AS) and platelet-rich plasma (PRP) on human corneal endothelial cell (HCEC) proliferation and apoptosis in comparison to Y-27632 as the commonly studied Rho-associated kinase (ROCK) inhibitor.

METHODS

The human corneal endothelial primary cell line was used for this study. As the treatment groups, HCECs were incubated with AS, PRP, and Y-27632, whereas the control group received no treatment. Cell proliferation (measured by 5-bromo-2'-deoxyuridine [BrdU] incorporation) and apoptosis (based on the caspase-3 level) were compared between the control, Y-27632, AS, and PRP groups.

RESULTS

In the Y-27632, AS, and PRP groups, the ratios of BrdU-incorporated cells were significantly higher (115±0.2%, 125±0.2%, 122±0.4% at 24 hr, and 138±2.4%, 160±0.2%, 142±0.2% at 48 hr, respectively) than in the control group (100±18.4% at 24 hr, 100±1.1% at 48 hr) ( P <0.05 for all). Furthermore, AS provided a higher HCEC proliferation ratio compared with the Y-27632 group at 24 and 48 hr ( P <0.05 for all). Caspase-3 was significantly lower in the AS group (60.3±3.3%) than in the control (100±2.3%), Y-27632 (101.9±5.2%), and PRP (101±6.8%) groups ( P <0.05 for all).

CONCLUSIONS

The results of this study demonstrated for the first time that AS and PRP promoted HCEC proliferation and AS significantly decreased apoptosis in HCECs. A superior effect on HCEC proliferation was also observed with AS compared with Y-27632. Future "autologous" regenerative therapeutic options for corneal endothelial failure may involve the utilization of AS and PRP owing to their accessibility, simplicity in preparation, immunologic compatibility, and donor-free nature.

Apoptosis in health and diseases of the eye and brain

Apoptosis is a form of programmed cell death (PCD) and enables the immunologically silent disposal of senescent or unwanted cells, causing minimal damage to the surrounding environment. Apoptosis can occur via intrinsic or extrinsic pathways that initiate a series of intracellular and extracellular signaling events. This ultimately leads to the clearance of the cell by phagocytes. This normal physiological mechanism may be accelerated in several diseases including those involving the eyes and brain, leading to loss of structure and function. This review presents the role of PCD in the health of the eyes and brain, and the evidence presented for its aberrant role in disease.

Evidence of Polyphenols Efficacy against Dry Eye Disease

Dry eye disease is a multifactorial pathology compromising the quality of life of patients, resulting in significant damage of the ocular surface and discomfort. The current therapeutical strategies are not able to definitively resolve the underlying causes and stop the symptoms. Polyphenols are promising natural molecules that are receiving increasing attention for their activity/effects in counteracting the main pathologic mechanisms of dry eye disease and reducing its symptoms. In the present review, a deep literature search focusing on the main polyphenols tested against dry eye disease was conducted, analyzing related in vitro, in vivo, and clinical studies to provide a comprehensive and current review on the state of the art. Polyphenols present multiple effects against dry eye diseases-related ocular surface injury. In particular, the observed beneficial effects of polyphenols on corneal cells are the reduction of the pathological processes of inflammation, oxidative stress, and apoptosis and modulation of the tear film. Due to numerous studies reporting that polyphenols are effective and safe for treating the pathological mechanisms of this ocular surface disease, we believe that future studies should confirm and extend the evidence of polyphenols efficacy in clinical practice against dry eye disease and help to develop new ophthalmic drug(s).

Effects of fine particulate matter on the ocular surface: An in vitro and in vivo study

Exposure to ambient fine particulate matter (fine PM) pollution has been previously associated with ocular surface diseases. But, to the best of our knowledge, the in vivo long-term effects of fine PM on the ocular surface have not been investigated. We aimed to evaluate the effects of fine PM on cultured human corneal epithelial (HCE) cells and on the ocular surfaces of mice, with standard reference material of fine PM(SRM 2786). We applied fine PM suspension to the eyes of C57BL/6 mice for up to 6 months. In vivo examinations, including tear secretion, tear film break-up time (TBUT) and corneal fluorescein staining, were performed in the 3^rd and 6^th month. At the end of the in vivo study, the corneal histological changes and conjunctival goblet cells were examined by staining, and cytokines in tissue were also detected. In addition, HCE cells were treated with fine PM for 12 h and 24 h. Then, cell apoptosis and reactive oxygen species (ROS) formation was detected. We found that fine PM damages the mouse eye in a dose- and time-dependent manner. In mice, the tear secretion and tear film break-up time were significantly reduced, along with the development of corneal epithelial damage, apoptosis of conjunctival epithelial cells and hypoplasia of conjunctival goblet cells. In addition, IL-18, IL-22, IL-23 and MCP-1 were increased in both conjunctiva and cornea of the fine PM-treated animals. Furthermore, increased apoptosis and ROS production were observed in time- and dose-dependent manner in HCE cells after fine PM exposure for 12 h and 24 h. Our results indicate that fine PM is cytotoxic to both HCE cells and the ocular surface. Long-term topical application of fine PM suspension in mice results in ocular surface changes that are similar to those observed with dry eye.

Overexpression of Smac is associated with the development of primary Sjogren's syndrome

BACKGROUND

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by keratoconjunctivitis sicca, xerostomia, and extraglandular abnormalities. The precise etiology remains unclear. Previous studies have revealed that the apoptosis played an important role in the pSS. Herein, we investigated the expression and effect of second mitochondria-derived activator of caspase (Smac) in patients with pSS and associated the expression with clinicopathological parameters.

METHODS

Smac expression was checked in labial salivary glands of surgical specimens from cases of pSS using immunohistochemistry, reverse transcription-quantitative PCR, and Western blot. The results of immunohistochemistry were analyzed for clinicopathological parameters. In addition, the content of Smac in cytoplasm and mitochondria were examined.

RESULTS

The mRNA of Smac, the content of Smac in cytoplasm, the Smac protein in the pSS patients increased significantly compared with the healthy controls (p < 0.05). The content of Smac in mitochondria decreased significantly compared with the healthy controls (p < 0.05). The integral optical density of Smac protein levels were positively correlated with IgG (r = 0.7435, p < 0.05) and erythrocyte sedimentation rate (ESR) (r = 0.7925, p < 0.05).

CONCLUSION

Smac plays an important role in the development of pSS.

Leptin/OB-R pathway promotes IL-4 secretion from B lymphocytes and induces salivary gland epithelial cell apoptosis in Sjögren's syndrome

Sjögren's syndrome (SjS) is a chronic autoimmune epithelitis in which cell apoptosis promotes the formation of inflammatory lesions. We used immunohistochemistry and TUNEL to assay B cell infiltration and apoptosis in salivary gland tissue from 16-week-old NOD/LtJ mice with SjS. In co-cultures of primary salivary glandepithelial cells (SGECs) and spleen B cells, we assessed SGEC viability and apoptosis using CCK8 assays and flow cytometry. ELISAs were employed to assess cytokine levels in culture medium. Leptin protein, leptin receptor (OB-R), pro- and anti-apoptotic proteins, and Jak2/Stat3/ERK signaling molecules were analyzed using western blotting. B cell infiltration and salivary gland apoptosis were increased in salivary tissue from mice with SjS. Leptin treatment had no effect on cell viability or apoptosis among B cells and primary SGECs. B cell and SGEC co-culture systems showed that leptin increased apoptosis induced by B lymphocytes, reduced SGEC cell viability, and promoted IL-4 secretion from B cells. This suggests Leptin/OB-R signaling stimulates B cells-induced SGEC apoptosis via IL-4 secretion and OB-R-Jak2-Stat3 activation.