Serum zinc-α2-glycoprotein levels are elevated and correlated with thyroid hormone in newly diagnosed hyperthyroidism

Sex impacts cardiac function and the proteome response to thyroid hormone in aged mice

Background

Sex and age have substantial influence on thyroid function. Sex influences the risk and clinical expression of thyroid disorders (TDs), with age a proposed trigger for the development of TDs. Cardiac function is affected by thyroid hormone levels with gender differences. Accordingly, we investigated the proteomic changes involved in sex based cardiac responses to thyroid dysfunction in elderly mice.

Methods

Aged (18–20 months) male and female C57BL/6 mice were fed diets to create euthyroid, hypothyroid, or hyperthyroid states. Serial echocardiographs were performed to assess heart function. Proteomic changes in cardiac protein profiles were assessed by 2-D DIGE and LC-MS/MS, and a subset confirmed by immunoblotting.

Results

Serial echocardiographs showed ventricular function remained unchanged regardless of treatment. Heart rate and size increased (hyperthyroid) or decreased (hypothyroid) independent of sex. Pairwise comparison between the six groups identified 55 proteins (≥ 1.5-fold difference and p < 0.1). Compared to same-sex controls 26/55 protein changes were in the female hypothyroid heart, whereas 15/55 protein changes were identified in the male hypothyroid, and male and female hyperthyroid heart. The proteins mapped to oxidative phosphorylation, tissue remodeling and inflammatory response pathways.

Conclusion

We identified both predicted and novel proteins with gender specific differential expression in response to thyroid hormone status, providing a catalogue of proteins associated with thyroid dysfunction. Pursuit of these proteins and their involvement in cardiac function will expand our understanding of mechanisms involved in sex-based cardiac response to thyroid dysfunction.

Beneficial Impact of Semicarbazide-Sensitive Amine Oxidase Inhibition on the Potential Cytotoxicity of Creatine Supplementation in Type 2 Diabetes Mellitus

Creatine supplementation of the population with type 2 diabetes mellitus (T2DM) combined with an exercise program is known to be a possible therapy adjuvant with hypoglycemic effects. However, excessive administration of creatine leads to the production of methylamine which is deaminated by the enzyme semicarbazide-sensitive amine oxidase (SSAO) and as a result, cytotoxic compounds are produced. SSAO activity and reaction products are increased in the serum of T2DM patients. Creatine supplementation by diabetics will further augment the activity of SSAO. The current review aims to find a feasible way to ameliorate T2DM for patients who exercise and desire to consume creatine. Several natural agents present in food which are involved in the regulation of SSAO activity directly or indirectly are reviewed. Particularly, zinc-α2-glycoprotein (ZAG), zinc (Zn), copper (Cu), histamine/histidine, caffeine, iron (Fe), and vitamin D are discussed. Inhibiting SSAO activity by natural agents might reduce the potential adverse effects of creatine metabolism in population of T2DM.