There is provided a method of therapy of atherosclerosis, by providing microRNA let-7g, an analogue thereof or modified let-7g to organisms to inhibit the expression of lectin-like oxidized low density lipoprotein receptor-1 (LOX-1), and the binding of LOX-1 and oxidized low-density lipoprotein (oxLDL), so as to block the pathogenesis of atherosclerosis. Also, a method of diagnosis of atherosclerosis comprises determining the levels of microRNA let-7g in serum or plasma samples of organisms, in which the levels of microRNA let-7g is estimated in individuals with atherosclerosis as compared to individuals without atherosclerosis.