thymosin-beta(4) and Corneal-Diseases

Thymosin beta 4 (Tβ4) has important applications in ocular repair and Phase 3 clinical trials using Tβ4 to treat dry eye and neurotrophic keratopathy are currently ongoing. These exciting clinical possibilities for Tβ4 in the eye are the result of seminal basic scientific discoveries and contributions from so many talented investigators. Areas covered: My personal Tβ4 journey began at the NIH in 1998 and propelled my career as a clinician scientist. As a tribute to the amazing individuals who have guided and supported me along with my brilliant colleagues and students who have contributed and collaborated with me over the years, this review will tell the cumulative story of how Tβ4 became a major potential new therapy for corneal wound healing disorders. The journey has been marked by the thrilling exhilaration from fundamental breakthroughs in the laboratory and clinic, combined with the challenging and often harsh realities of submitting grants and obtaining funding. Expert opinion: The electrifying possibility of Tβ4 as a revolutionary novel dry eye therapy is something that could have only been dreamed about just a few years ago. We believe that Tβ4 eyedrops will help many patients suffering from several ocular surface related disorders.

Topics: Animals; Corneal Diseases; Corneal Keratocytes; Dry Eye Syndromes; Eye; Humans; Ocular Physiological Phenomena; Thymosin; Translational Research, Biomedical; Wound Healing

Chronic ocular surface diseases such as dry eye, blepharitis, and neurotrophic keratopathies represent a significant and a growing therapeutic challenge. The basis of this expanding prevalence is multifactorial and may due to issues such as an aging population, an increasing use of video display terminals, and increases in frequency of refractive surgeries. The growing incidence of diseases such as diabetes may also be a contributing factor. Current treatments for ocular surface disease include artificial tears, lubricants, tear duct plugs, steroids, antibiotics, cyclosporine, scleral lenses, and serum tears. Treatment choices depend on the type and severity of the disease, but in general positive outcomes are limited because many of these treatments do not fully address the underlying disease process or promote mechanisms that facilitate long-term wound repair. From minor corneal injuries to more severe inflammatory-mediated pathologies, clinicians need agents that promote corneal healing and reduce the inflammatory response to prevent visual disturbances and improve quality of life. A focus on treatments that reduce the inflammatory responses while accelerating corneal epithelial growth would represent a major step forward from current treatment options. Increasing evidence suggests that thymosin beta 4 (Tβ4), a naturally occurring polypeptide, can elicit this spectrum of therapeutic responses: a rapid corneal reepithelialization and a reduction in corneal inflammation. This chapter serves as a review of standard therapies as well as recent advancements in the development of newer therapies that includes the use of Tβ4 that is proving to be an exciting new agent for the management of ocular surface disease.

Topics: Animals; Anti-Inflammatory Agents; Corneal Diseases; Disease Models, Animal; Dry Eye Syndromes; Humans; Thymosin; Wound Healing

Persistent corneal epithelial defects and inflammation within the central cornea can directly distort visual acuity and may lead to permanent visual loss. Therefore, treatments with agents that enhance corneal reepithelialization and regulate the inflammatory response without the deleterious side effects of currently used agents such as corticosteroids would result in improved clinical outcome and would represent a major advance in the field. Despite much progress in the areas of corneal wound healing research, clinically available pharmacological therapies that can promote repair and limit the visual complications from persistent corneal wounds are severely limited and remains a major deficiency in the field. Prior studies from our laboratory have demonstrated the potent wound healing and anti-inflammatory effects of thymosin beta4 (Tbeta(4); Tbeta4) in numerous models of corneal injury. We are studying the mechanisms by which Tbeta(4) suppresses inflammation and promotes repair. Herein, we discuss some of our new basic scientific directions that may lead to the use of Tbeta(4) as a novel corneal wound healing and anti-inflammatory therapy.

Topics: Adrenal Cortex Hormones; Animals; Corneal Diseases; Corneal Injuries; Eye Injuries; Forecasting; Inflammation; Mice; Thymosin; Wound Healing

The cornea epithelium responds to injury by synthesizing several cytokines, growth factors, and tissue remodeling molecules. Proinflammatory cytokines have been implicated in the inflammation that follows corneal epithelial injury and cytokine-mediated processes play a significant role in corneal epithelial wound healing. Poorly regulated corneal inflammatory reactions that occur after injury can retard healing. In turn, persistent corneal epithelial defects and inflammation may lead to ocular morbidity and permanent visual loss. Therefore, treatments with agents that enhance corneal reepithelialization and regulate the inflammatory response without the deleterious side effects of currently used agents, such as corticosteroids, would result in improved clinical outcome and would represent a major advance in the field. Evidence is mounting to support the idea that thymosin beta-4 (Tbeta-4) has multiple, seemingly diverse, cellular functions. In the cornea, as in other tissues, Tbeta-4 promotes cell migration and wound healing, has anti-inflammatory properties, and suppresses apoptosis. Prior studies from our laboratory have demonstrated the potent wound healing and anti-inflammatory effects of Tbeta-4 in numerous models of corneal injury. Recently, we demonstrated that Tbeta-4 suppresses the activation of the transcription factor, nuclear factor-kappa b (NF-kappaB) in TNF-alpha-stimulated cells. TNF-alpha initiates cell signaling pathways that converge on the activation of NF-kappaB, thus both are known mediators of the inflammatory process. These results have important clinical implications for the potential role of Tbeta-4 as a corneal anti-inflammatory and wound-healing agent.

Topics: Apoptosis; Corneal Diseases; Diabetic Retinopathy; Epithelial Cells; Eye Diseases; Humans; Inflammation; Ocular Physiological Phenomena; Thymosin; Wound Healing

Topics: Aged, 80 and over; Chronic Disease; Compassionate Use Trials; Corneal Diseases; Diabetes Complications; Epithelium, Corneal; Female; Herpes Zoster Ophthalmicus; Humans; Male; Middle Aged; Ophthalmic Solutions; Thymosin

Corneal alkali injury is highly caustic, and present clinical therapies are limited. The purpose of this study was to investigate the ability of thymosin-beta4 (Taubeta4) to promote healing in an alkali injury model and the mechanisms involved in that process.. Corneas of BALB/c mice were injured with NaOH, irrigated copiously with PBS, and treated topically with either Tbeta4 or PBS twice daily. At various time points after injury (PI), corneas from the Tbeta4- versus the PBS-treated group were examined for polymorphonuclear leukocyte (PMN) infiltration, chemokine, and matrix metalloproteinase (MMP)/tissue inhibitor of metalloproteinase (TIMP) expression.. Tbeta4-treated corneas demonstrated improved corneal clarity at day 7 PI. Whereas Tbeta4 decreased corneal MMP-2 and -9 and MT6-MMP levels after alkali injury, no change in TIMP-1 and -2 expression was detected. Tbeta4 treatment also decreased corneal KC (CXCL1) and macrophage inflammatory protein (MIP)-2 chemokine expression and PMN infiltration. Immunohistochemistry studies demonstrated MMP-9 expression at the leading edge of the epithelial wound, in the the limbus (containing stem cells), and in stromal PMNs.. Tbeta4 treatment decreases corneal inflammation and modulates the MMP/TIMP balance and thereby promotes corneal wound repair and clarity after alkali injury. These results suggest that Tbeta4 may be useful clinically to treat severe inflammation-mediated corneal injuries.

Topics: Animals; Burns, Chemical; Chemokines; Corneal Diseases; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Eye Burns; Matrix Metalloproteinases; Mice; Mice, Inbred BALB C; Neutrophil Infiltration; Neutrophils; Reverse Transcriptase Polymerase Chain Reaction; Sodium Hydroxide; Thymosin; Tissue Inhibitor of Metalloproteinases; Wound Healing