Small peptide compositions and uses thereof

Interferon-γ-inducible protein 10 (IP-10) peptides, IP-10 peptide variants and in silico designed C-X-C chemokine receptor 3 (CXCR3) peptide agonists are described. The small peptides can be used for inhibiting pathological tissue remodeling and treating fibrosis in a subject, such as a subject with fibrosis of the heart, lung, liver, kidney or skin. The peptide agonists can also be used to treat cardiovascular disease, including myocardial infarction and ischemia-reperfusion injury. Also described are in silico designed peptide antagonists that bind CXCR3 or ligands of CXCR3. These antagonist peptides block CXCR3 signaling by disrupting interaction of CXCR3 with its ligand. Antagonist peptides can be used, for example, to treat myocarditis and atherosclerosis. In additional embodiments agonists and antagonists of CXCR4 are disclosed.