Genistein, a natural product from soy, is a potent inhibitor of transthyretin amyloidosis

Abstract

The misfolding of transthyretin (TTR), including rate-limiting tetramer dissociation and partial monomer denaturation, is sufficient for TTR misassembly into amyloid and other abnormal quaternary structures associated with three amyloid diseases: senile systemic amyloidosis, familial amyloid polyneuropathy, and familial amyloid cardiomyopathy. Small molecules can bind to one or both of the unoccupied TTR thyroid hormone-binding sites, stabilizing the native tetramer more than the dissociative transition state, thereby raising the kinetic barrier for tetramer dissociation. Herein we demonstrate that genistein, the major isoflavone natural product in soy, works in this fashion and is an excellent inhibitor of transthyretin tetramer dissociation and amyloidogenesis, reducing acid-mediated fibril formation to <10% of that exhibited by TTR alone. Genistein also inhibits the amyloidogenesis of the most common familial amyloid polyneuropathy and familial amyloid cardiomyopathy mutations in TTR: V30M and V122I, respectively. Genistein additionally inhibits tetramer dissociation under physiological conditions thought to lead to slow amyloidogenesis in humans. Furthermore, this natural product exhibits highly selective binding to TTR in plasma over all of the other plasma proteins. Isothermal titration calorimetry shows that genistein binds to TTR with negative cooperativity (K d1 ‫؍‬ 40 nM, Kd2 ‫؍‬ 1.4 M). The benefits of using a nutraceutical such as genistein to treat orphan diseases such as the TTR amyloidoses include known oral bioavailability and safety data. It is conceivable that some patients could benefit from simply increasing their intake of soy products or supplements.amyloidogenesis inhibitor ͉ kinetic stabilization F or many years nutritionists and dieticians have noted the health benefits of a soy-based diet, citing the much lower incidence of cancer, including breast cancer, in Asian countries (1-4). The isoflavone genistein (compound 1 in Fig. 1), found in various soy foods at concentrations of 1.9-229 g͞g, is the component of soy implicated in cancer chemoprevention (5). An additional 71-968 g͞g of genistein is present as its O-glucoside conjugate, genistin (2), which is rapidly deglycosylated by intestinal bacteria in vivo. Genistein is being evaluated in preliminary trials for treatment of breast, prostate, and uterine cancers (6, 7), as well as for osteoporosis (8), cardiovascular disease (9), and treatment of menopausal symptoms (10). Toxicity studies reveal that this isoflavone does not appear to cause adverse health effects, even at the relatively high concentrations used (11-13). The isoflavone daidzein (3), lacking the hydroxyl group at the 5 position of genistein, is also found in soy foods, but no chemoprotective effects have been attributed to it.Transthyretin (TTR) is a tetrameric protein composed of identical 127-aa ␤-sheet sandwich subunits (14, 15). TTR functions to transport holo-retinol-binding protein and thyroxine (T4) in the blood and cerebrospinal fluid (16,17). Under denaturing con...

Therapeutic targeting of nuclear receptor corepressor misfolding in acute promyelocytic leukemia cells with genistein

“…Besides being an inhibitor of receptor tyrosine kinase activity, genistein is also known to be a potent inhibitor of ER stress in mammalian cells (13,14). Recently, genistein was reported to be a potent inhibitor of transthyretin misfolding, a protein involved in the pathogenesis of transthyretin amyloidosis (15). In agreement with these findings, here we report that genistein inhibits PML-RAR -induced misfolding and insoluble aggregation of N-CoR protein and promotes growth arrest in both RAsensitive and RA-resistant APL cells through a collective regulatory effect on cell cycle progression, apoptosis, and differentiation.…”

Chemical and Biological Approaches for Adapting Proteostasis to Ameliorate Protein Misfolding and Aggregation Diseases-Progress and Prognosis

“…Cite this article as Cold Spring Harb Perspect Biol 2011;3:a004507 under physiological conditions, precluding amyloidogenesis (Miroy et al 1996;Baures et al 1998Baures et al , 1999Oza et al 1999Oza et al , 2002Klabunde et al 2000;Petrassi et al 2000Petrassi et al , 2005Green et al 2003;Hammarstrom et al 2003;Razavi et al 2003Razavi et al , 2005Adamski-Werner et al 2004;Miller et al 2004;Purkey et al 2004;Green et al 2005;Johnson et al 2005aJohnson et al ,b, 2008aJohnson et al ,b, 2009Wiseman et al 2005;Sekijima et al 2006;Tojo et al 2006;Choi et al 2010a,b;Connelly et al 2010). Tafamidis, a benzoxazole-based transthyretin kinetic stabilizer discovered in academia (Razavi et al 2003) and developed by FoldRx Pharmaceuticals, showing a 2 nM dissociation constant from transthyretin (Razavi et al 2003 Figure 14.…”

Genistein Derivatization – From a Dietary Supplement to a Pharmaceutical Agent

“…Since only 1% of TTR is bound to thyroxine, small molecules, such as genistein may help to stabilize the tetrameric structure. Genistein is known to potently inhibit TTR amyloid fibril formation (Green et al, 2005). In TTR, the mode of genistein binding is sequential, with negative cooperativity observed.…”

“…1., which does not fit any group described above, such as ornithyne decarboxylase, aromatase CYP19 or tubulin. Cytoskeleton protein, tubulin binds genistein at ANS-binding site, what leads to depolymerization of microtubules (Mukherjee et al, 2010 Stabilisator of a tetramer Green et al, 2005 (Bloedon et al, 2002;Setchell et al, 2001). Tab.…”