Study On The Mechanism Of Combined Use Of Sulforaphane And Zinc To Protect Diabetes Cardiomyopathy And Intermittent Hypoxic Cardiomyopathy Through Antioxidant Stress Pathway

Background:Diabetes is one of the most common chronic diseases,which is characterized by elevated blood glucose concentration.In recent years,the prevalence of diabetes and the number of patients continue to increase.As of 2017,there are about 425 million people with diabetes aged 20-79 in the world.It is estimated that by 2045,the number of diabetes patients in this age group will increase to 629 million,accounting for 9.9% of the total population.5%-10% of patients diagnosed with diabetes are type 1 diabetes(T1D)patients,which is a disease caused by multiple factors.Hereditary factors account for a large proportion β Cells are damaged due to autoimmune factors,ultimately leading to absolute insulin secretion deficiency.The disease incidence rate of type 1 diabetes is increasing worldwide.The complications of diabetes seriously affect human health,which is the main reason for the increased mortality and disability rate of type 1 diabetes patients.Compared with people without diabetes,cardiovascular events in T1D patients are not only more common,but also occur earlier.Diabetes cardiomyopathy(DCM)is the main cause of heart failure in diabetes patients and one of the most fatal complications.The concept of DCM is generally considered as type 2 diabetes patients with poor glycemic control;However,ischemic cardiomyopathy independent of hypertension,kidney disease,or metabolic induction is also common in T1D patients.The pathogenesis of DCM is currently not fully understood,but oxidative stress is considered one of the most important pathophysiological factors.Therefore,treatment for oxidative stress may represent an appropriate strategy for effectively preventing DCM.Studies have shown that metallothionein(MT)is located downstream of the nuclear factor NE-F2 related factor 2(Nrf2)and regulates the expression of Nrf2.Zinc(Zn)stimulates Nrf2 expression and transcription by activating Akt dependent inhibition of Fyn nuclear translocation.Considering that the protective effect of sulforaphane(SFN)and Zn on diabetes induced organ damage depends on the activation of different molecular targets(Nrf2 and MT,respectively),the two pathways can interact.Compared with single treatment,SNF and Zn combined treatment may provide better protection for diabetes induced complications.However,published studies have not yet determined whether this combination is more effective in alleviating oxidative stress and preventing the development of DCM than using two substances alone.Obstructive sleep apnea syndrome is one of the most common respiratory disorders during sleep,with a prevalence rate of 3-7%and serious consequences.Its clinical feature is intermittent hypoxia(IH),which is caused by repeated partial or complete collapse of the upper respiratory tract during sleep,leading to blood hypoxemia,hypercapnia,sleep fragmentation,increased respiratory effort,and increased sympathetic nervous activity.Long term IH can lead to left ventricular remodeling and dysfunction,and can promote ventricular arrhythmias and sudden cardiac death.Although several potential mechanisms have been proposed,oxidative stress is currently considered the main mechanism by which IH causes heart damage.Oxidative stress represents the imbalance between the production of reactive oxygen species(ROS)and/or reactive nitrogen species(RNS)and the antioxidant capacity of biological systems.Many studies using animal models have confirmed the hypothesis that oxidative stress plays a crucial role in the pathogenesis of chronic IH induced cardiomyopathy,leading to DNA breakage,cell apoptosis,and autophagy.Therefore,treatment for oxidative stress may be effective in preventing chronic IH induced cardiac injury.Both Nrf2 and MT have been reported to prevent chronic IH induced cardiomyopathy.Broccoli Sprout Extract(BSE)and Zn,rich in thioether,can effectively induce Nrf2 and MT,respectively,to prevent IH induced cardiomyopathy through antioxidant stress.However,whether the protective effect of the combination of BSE and Zn on the heart can be synergistic or equivalent has not yet been evaluated.Purpose:(1)a T1D genetic mouse model,OVE26 mice,was used to compare the effects of SFN,Zn,and/or combination therapy on DCM.(2)Use a chronic IH model to compare the effects of Zn,BSE independence,and their combination on IH induced cardiac dysfunction and pathogenic mechanisms.Method and Results:In the study,5-week-old OVE mice with spontaneous type 1 diabetes were treated with SFN and/or Zn for 18 weeks.In OVE mice,cardiac dysfunction was observed through echocardiography,as well as pathological changes and remodeling in cardiac hypertrophy,fibrosis,inflammation,and oxidative damage detected through histopathology,protein blotting,and real-time PCR.All of these functional and pathological abnormalities observed in OVE mice were attenuated in OVE mice treated with SFN,Zn,or SFN/Zn,and the combination therapy with SFN/Zn was superior to single therapy in improving DCM.In addition,the combination of SFN and Zn treatment significantly increased Nrf2 function and MT expression in the hearts of OVE mice compared to SFN or Zn alone.In the study,8-week-old C57BL/6J mice were treated with BSE and/or zinc for8 weeks of IH exposure.Cardiac dysfunction determined by echocardiography,as well as pathological remodeling and abnormalities,including cardiac fibrosis,inflammation,and oxidative damage,detected by histopathology and Western blotting,were clearly observed in IH mice,but not significantly in IH mice treated with BSE,zinc,or zinc/BSE.In addition,the combined treatment of BSE and zinc is always more effective than a single treatment.Conclusion:(1)Through the combination therapy of SFN and Zn,the dual activation of Nrf2 and MT may be more effective than single therapy,preventing the development of DCM through complementary and additive mechanisms.(2)Compared to using BSE or zinc alone,the combination of BSE and zinc showed a greater increase in Nrf2 function and metallothionein expression in the heart.Through the combination therapy of BSE and zinc,the dual activation of Nrf2 and metallothionein may be more effective in preventing the development of IH induced cardiomyopathy than single therapy.