Use of galectin-7 to promote the re-epithelialization of wounds

The present application claims priority to provisional application U.S. Ser. No. 60/286,903, filed Apr. 27, 2001 which is incorporated herein by reference in its entirety.

This invention was made with Government support under grant number EY-07088 from the National Institutes of Health. Accordingly, the government may have certain rights in this invention.

The repair of wounds in mammalian tissue (e.g., epithelial defects, lesions, or erosions caused by disease, accidental injury, surgical procedure, etc.) involves an orderly, controlled cellular response. Three phases have been described in normal wound healing: acute inflammatory phase, extracellular matrix and collagen synthesis, and remodeling (Wound Repair by Peacock, W.B. Saunders, Philadelphia, Pa., 1984). The sequence of the healing process is initiated during an acute inflammatory phase with the deposition of provisional tissue. This is followed by re-epithelialization, collagen synthesis and deposition, fibroblast proliferation, and neovascularization, all of which ultimately define the remodeling phase (see, for example, Clark, J. Am. Acad Dermatol. 13:701, 1985). These events are known to be influenced by growth factors and cytokines secreted by inflammatory cells and by epithelial cells, endothelial cells, platelets, and fibroblasts localized at the edges of the wound (see, for example, The Molecular and Cellular Biology of Wound Repair (The Language of Science) Ed. by Clark, Plenum Press, New York, N.Y., 1996; Hunt et al., in The Surgical Wound Ed. by Dineen at al., Lea & Febiger, Philadelphia, Pa., 1981; Nemeth et al., in Growth Factors and Other Aspects of Wound Healing: Biological and Clinical Implications Ed. by Barbul et al., A. R. Liss, New York, N.Y., 1988; and Assoian et al., Nature 309:804, 1984). During re-epithelialization, cells at the leading edge undergo a phenotypic conversion characterized by a dramatic reorganization of the cytoskeleton, disruption of stable intercellular adhesion, and redistribution of adhesion related molecules. The breakage of the stable intercellular contacts is a prerequisite for initiating re-epithelialization. Following re-epithelialization, reversion to the epithelial phenotype, including the reformation of stable intercellular contacts, must occur if the function of the epithelium is to be fully restored. The failure of epithelial cells to migrate over the wound surface and failure of migrated epithelial cells to remain adherent to the substratum are fundamental causes of debilitating clinical conditions known as persistent epithelial defects (i.e., non healing defects) and recurrent epithelial erosions respectively.

Disorders of wound healing constitute a serious medical problem for several different organ systems including the skin, gastrointestinal tract, and cornea. For example, loss of cell-cell adhesions within the epidermis produces life-threatening blistering skin diseases known as pemphigus foliaceus and pemphigus vulgaris (Cell Adhesion and Human Disease Ed. by Marsh et al., Ciba Foundation Symposium, Vol. 189, John Wiley & Sons, New York, N.Y., 1995). Persistent epithelial defects in the form of delayed re-epithelialization are a characteristic of chronic skin wounds, in particular venous stasis ulcers (Falanga et al., J. Dermatol. Surg. Oncol. 19:764, 1993). Within the cornea, lack of epithelial cell adhesion to the stroma and the basement membrane leads to recurrent corneal erosions (Macaluso et al., in Cornea Ed. by Krachmer, Mosby, St. Louis Mo., 1997). Persistent corneal epithelial defects occur in a wide variety of clinical situations such as in injuries caused by radiation, corneal abrasions or lacerations, chemical burns of the cornea such as alkali and acid burns, keratopathies, keratities and corneal dystrophies. Persistent corneal epithelial defects carry a high risk of corneal perforation and ulceration (Macaluso et al., supra).

Despite the need for more rapid healing of wounds, to date there has been only limited success in accelerating wound healing with pharmaceutical agents. In the case of corneal injuries, the use of epidermal growth factor (Eiferman et al., Invest. Opthalmol. Vis. Sci. (Suppl.) 28:52, 1987), fibronectin (Nishida et al., J. Cell. Biol. 97:1653, 1983), collagenase inhibitors (Kenyon et al., Invest. Opthalmol. Vis. Sci. 18:570, 1979), topical steroids (Lass et al., Arch. Opthalmol. 99:673, 1981), matrix metalloproteinase inhibitors (Murphy et al., Biochemistry 30:8097, 1991), ascorbates (Foster et al., Invest. Opthalmol. Vis. Sci. (Suppl.) 19:227, 1980), heparin (Aronson, Am. J. Opthalmol. 70:65, 1970), and tetracyclines (Perry et al., Ophthalmology (Suppl.) 92:77, 1985) does not always result in successful long-term management. For example, topical application to a corneal injury of epidermal growth factor (EGF) (Singh et al., Am. J. Opthalmol. 103:802, 1987) or fibronectin (Tenn et al., Invest. Opthalmol. Vis. Sci. (Suppl.) 26:92, 1985), enhances epithelial wound healing but does not prevent recurrent erosion and secondary breakdown of the corneal epithelial surface.

Accordingly, there is a need in the art for additional pharmaceutical agents and compositions that promote the healing of wounds. In particular, there is a need for agents, compositions and therapeutic methods that promote the re-epithelialization of persistent epithelial defects and prevent recurrent epithelial erosions.

In one aspect, the present invention provides methods for the therapeutic treatment of epithelial injuries in mammalian tissue involving administering to a mammal afflicted with an epithelial injury a therapeutically effective amount of galectin-3, galectin-7, or a combination of galectin-3 and galectin-7.

In another aspect, the present invention provides pharmaceutical compositions that include a pharmaceutically acceptable carrier or diluent and an amount of galectin-3 and/or galectin-7 sufficient to promote the re-epithelialization of wounds in injured mammalian tissues.

In general, it is believed that galectin-3 and/or galectin-7 will be clinically useful in promoting the healing of wounds associated with any epithelial tissue including but not limited to the skin epithelium; the corneal epithelium; the lining of the gastrointestinal tract; the lung epithelium; and the inner surface of kidney tubules, of blood vessels, of the uterus, of the vagina, of the urethra, or of the respiratory tract. The present invention encompasses the treatment of a variety of wounds that include but are not limited to persistent epithelial defects and recurrent epithelial erosions such as surgical wounds, excisional wounds, blisters, ulcers, lesions, abrasions, erosions, lacerations, boils, cuts, sores, and burns resulting from heat exposure or chemicals. These wounds may be in normal individuals or those subject to conditions which induce abnormal wound healing such as diabetes, corneal dystrophies, uremia, malnutrition, vitamin deficiencies, obesity, infection, immunosuppression and complications associated with systemic treatment with steroids, radiation therapy, non-steroidal anti-inflammatory drugs (NSAID), anti-neoplastic drugs and anti-metabolites.

In certain embodiments, the present invention involves the administration of pharmaceutical compositions that include galectin-3 proteins with the amino acid sequence of human galectin-3 as represented by SEQ ID NO:1 of the sequence listing. In other embodiments, the present invention involves the administration of pharmaceutical compositions that include galectin-3 proteins with an amino acid sequence that is substantially identical to the amino acid sequence of SEQ ID NO:1. For example, in certain embodiments, the present invention involves the administration of pharmaceutical compositions that include galectin-3 proteins which contain accidentally or deliberately induced alterations, such as deletions, additions, substitutions or modifications of the amino acid residues of SEQ ID NO:1. In yet other embodiments, the present invention involves the administration of pharmaceutical compositions that include proteins represented by fragments of the amino acid sequence SEQ ID NO:1 or hybrid proteins that comprise these fragments. Fragments of SEQ ID NO:1 preferably include a galectin-3 N-terminal domain and a galectin-3 proline, glycine, and tyrosine-rich domain; a galectin-3 proline, glycine, and tyrosine-rich domain and a galectin-3 galactoside-binding domain; or a galectin-3 galactoside-binding domain.

In certain other embodiments, the present invention involves the administration of pharmaceutical compositions that include galectin-7 proteins with the amino acid sequence of human galectin-7 as represented by SEQ ID NO:2 of the sequence listing. In other embodiments, the present invention involves the administration of pharmaceutical compositions that include galectin-7 proteins with an amino acid sequence that is substantially identical to the amino acid sequence of SEQ ID NO:2. For example, in certain embodiments, the present invention involves the administration of pharmaceutical compositions that include galectin-7 proteins which contain accidentally or deliberately induced alterations, such as deletions, additions, substitutions or modifications of the amino acid residues of SEQ ID NO:2. In yet other embodiments, the present invention involves the administration of pharmaceutical compositions that include proteins, represented by fragments of the amino acid sequence SEQ ID NO:2 or hybrid proteins that comprise these fragments. Preferred fragments of SEQ ID NO:2 include a galectin-7 galactoside-binding domain.

The present invention also encompasses the administration of pharmaceutical compositions that include proteins represented by the amino acid sequence of galectin-3 and/or galectin-7 taken from any mammalian species including but not limited to bovine, canine, feline, caprine, ovine, porcine, murine, and equine species.

In certain embodiments, the pharmaceutical compositions of the present invention further include one or more additional therapeutic agents. In certain embodiments, the additional therapeutic agent or agents are selected from the group consisting of growth factors, anti-inflammatory agents, vasopressor agents, collagenase inhibitors, topical steroids, matrix metalloproteinase inhibitors, ascorbates, angiotensin II, angiotensin III, calreticulin, tetracyclines, fibronectin, collagen, thrombospondin, transforming growth factors (TGF), keratinocyte growth factor (KGF), fibroblast growth factor (FGF), insulin-like growth factors (IGF), epidermal growth factor (EGF), platelet derived growth factor (PDGF), neu differentiation factor (NDF), hepatocyte growth factor (HGF), and hyaluronic acid.

The pharmaceutical compositions of the present invention can be administered to humans and other mammals topically, orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, bucally, ocularly, or nasally, depending on the severity and location of the wound being treated. Administration may be therapeutic or it may be prophylactic. Liquid dosage forms for oral administration of an inventive pharmaceutical composition include, but are not limited to, pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. Dosage forms for topical or transdermal administration include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants, or patches. Injectable preparations may be in the form of sterile injectable aqueous or oleaginous suspensions. Compositions for rectal or vaginal administration are preferably suppositories. Prophylactic formulations may be present or applied to the site of potential wounds, or to sources of wounds, such as contact lenses, contact lens cleaning and rinsing solutions, containers for contact lens storage or transport, devices for contact lens handling, eye drops, surgical irrigation solutions, ear drops, eye patches, and cosmetics for the eye area. The invention includes opthalmological devices, surgical devices, audiological devices or products which contain disclosed pharmaceutical compositions (e.g., gauze bandages or strips).