Therapeutic Effect of a Latent Form of Cortistatin in Experimental Inflammatory and Fibrotic Disorders.

Cortistatin is a cyclic neuropeptide that recently emerged as an attractive therapeutic factor for treating inflammatory, autoimmune, fibrotic, and pain disorders. Despite of its efficiency and apparent safety in experimental preclinical models, its short half-life in body fluids and its potential pleiotropic effects, due to its promiscuity for several receptors expressed in various cells and tissues, represent two major drawbacks for the clinical translation of cortistatin-based therapies. Therefore, the design of new strategies focused on increasing the stability, bioavailability, and target specificity of cortistatin are lately demanded by the industry. Here, we generated by molecular engineering a new cortistatin-based prodrug formulation that includes, beside the bioactive cortistatin, a molecular-shield provided by the latency-associated protein of the transforming growth factor-ß1 and a cleavage site specifically recognized by metalloproteinases, which are abundant in inflammatory/fibrotic foci. Using different models of sepsis, inflammatory bowel disease, scleroderma, and pulmonary fibrosis, we demonstrated that this latent form of cortistatin was a highly effective protection against these severe disorders. Noteworthy, from a therapeutic point of view, is that latent cortistatin seems to require significantly lower doses and fewer administrations than naive cortistatin to reach the same efficacy. Finally, the metalloproteinase-cleavage site was essential for the latent molecule to exert its therapeutic action. In summary, latent cortistatin emerges as a promising innovative therapeutic tool for treating chronic diseases of different etiologies with difficult clinical solutions and as a starting point for a rational development of prodrugs based on the use of bioactive peptides.

Neuropeptide Cortistatin Regulates Dermal and Pulmonary Fibrosis in an Experimental Model of Systemic Sclerosis.

INTRODUCTION: Scleroderma, or systemic sclerosis, is a complex connective tissue disorder characterized by autoimmunity, vasculopathy, and progressive fibrosis of the skin and internal organs. Because its aetiology is unknown, the identification of genes/factors involved in disease severity, differential clinical forms, and associated complications is critical for understanding its pathogenesis and designing novel treatments. Neuroendocrine mediators in the skin emerge as potential candidates. We investigated the role played by the neuropeptide cortistatin in a preclinical model of scleroderma. METHODS: Dermal fibrosis was induced by repetitive intradermal injections of bleomycin in wild-type and cortistatin-deficient mice. The histopathological signs and expression of fibrotic markers were evaluated in the skin and lungs. RESULTS: An inverse correlation between cortistatin levels and fibrogenic activation exists in the damaged skin and dermal fibroblasts. Bleomycin-challenged skin lesions of mice that are partially and totally deficient in cortistatin showed exacerbated histopathological signs of scleroderma, characterized by thicker and more fibrotic dermal layer, enlarged epidermis, and increased inflammatory infiltration in comparison to those of wild-type mice. Cortistatin deficiency enhanced dermal collagen deposits, connective tissue growth factor expression, loss of microvessels, and predisposition to suffer severe complications that co-occur with dermal exposition to bleomycin, including pulmonary fibrotic disease and increased mortality. Treatment with cortistatin mitigated these pathological processes. DISCUSSION/CONCLUSION: We identify cortistatin as an endogenous break of skin inflammation and fibrosis. Deficiency in cortistatin could be a marker of poor prognosis of scleroderma and associated complications. Cortistatin-based therapies emerge as attractive candidates to treat severe forms of systemic sclerosis and to manage fibrosis-related side effects of bleomycin chemotherapy in oncologic patients.

Protective role of cortistatin in pulmonary inflammation and fibrosis.

BACKGROUND AND PURPOSE: Acute lung injury (ALI), acute respiratory distress syndrome (ARDS) and pulmonary fibrosis remain major causes of morbidity, mortality and a healthcare burden in critically ill patient. There is an urgent need to identify factors causing susceptibility and for the design of new therapeutic agents. Here, we evaluate the effectiveness of the immunomodulatory neuropeptide cortistatin to regulate pulmonary inflammation and fibrosis in vivo. EXPERIMENTAL APPROACH: ALI/ARDS and pulmonary fibrosis were induced experimentally in wild-type and cortistatin-deficient mice by pulmonary infusion of the bacterial endotoxin LPS or the chemotherapeutic drug bleomycin, and the histopathological signs, pulmonary leukocyte infiltration and cytokines, and fibrotic markers were evaluated. KEY RESULTS: Partially deficient mice in cortistatin showed exacerbated pulmonary damage, pulmonary inflammation, alveolar oedema and fibrosis, and subsequent increased respiratory failure and mortality when challenged to LPS or bleomycin, even at low doses. Treatment with cortistatin reversed these aggravated phenotypes and protected from progression to severe ARDS and fibrosis, after high exposure to both injury agents. Moreover, cortistatin-deficient pulmonary macrophages and fibroblasts showed exaggerated ex vivo inflammatory and fibrotic responses, and treatment with cortistatin impaired their activation. Finally, the protective effects of cortistatin in ALI and pulmonary fibrosis were partially inhibited by specific antagonists for somatostatin and ghrelin receptors. CONCLUSION AND IMPLICATIONS: We identified cortistatin as an endogenous inhibitor of pulmonary inflammation and fibrosis. Deficiency in cortistatin could be a marker of poor prognosis in inflammatory/fibrotic pulmonary disorders. Cortistatin-based therapies could emerge as attractive candidates to treat severe ALI/ARDS, including SARS-CoV-2-associated ARDS.