Selenium is an essential nutrient closely related to redox homeostasis in the body.A redox imbalance will adversely affect the microenvironment inside and outside the cell,leading to cell death.Various types of cell d...Selenium is an essential nutrient closely related to redox homeostasis in the body.A redox imbalance will adversely affect the microenvironment inside and outside the cell,leading to cell death.Various types of cell death have been discovered in recent years,but the role(s)of selenium and the associated mechanism(s)of action require further elaboration.We review the roles and mechanisms of action of selenium in cell necrosis,apoptosis,ferroptosis,autophagy,and pyroptosis.Under normal conditions,selenium inhibits cell necrosis,apoptosis,ferroptosis,autophagy,and pyroptosis by downregulating the nuclear factorκB pathway,upregulating antiapoptotic proteins,decreasing oxidative stress,increasing antioxidant enzyme activity,enhancing the mTOR pathway,and downregulating the NLRP3/caspase-1 pathway,thereby helping to maintain the normal physiological functions of cells.On the other hand,selenium deficiency leads to activation of the PI3K/AKT and Notch/Hes1 pathways,causing a significant increase in the level of oxidative stress in the organism,resulting in cell necrosis,apoptosis,and pyroptosis.In the case of malignancy,the in vivo metabolite of inorganic selenium,hydrogen selenide,plays an antitumor role by inducing apoptosis and ferroptosis in tumor cells because of its high redox activity.In conclusion,an adequate level of selenium in the body is essential for maintaining normal cellular physiological functions and reducing fibrotic alterations.Furthermore,the in vivo metabolites of inorganic selenium may have some clinical value in antitumor therapy.展开更多
Cyclic dinucleotides(CDNs) are known to activate stimulator of interferon genes(STING) and induce type I interferon responses, therefor possess great potentials to be of immunotherapeutic value for cancers and infecti...Cyclic dinucleotides(CDNs) are known to activate stimulator of interferon genes(STING) and induce type I interferon responses, therefor possess great potentials to be of immunotherapeutic value for cancers and infectious diseases. However, the existence of different single nucleotide polymorphism(SNP) of human STING(hSTING) gene poses an obstacle to achieve broad-spectrum activation by CDNs. We reported here the design and synthesis of a total of 36 CDNs, representing all structural variations, that contain four bases(A, G, C, U) and two linkage directions(2′-5′-linked and 3′-5′-linked phosphodiester).Through systematic evaluation of IFN-β induction with a dual-luciferase reporter assay, we discovered that wild type hSTING and two isoforms(HAQ and AQ) showed strong response while hSTING-R232 H and R293 Q exhibited the relatively weak response to CDNs stimulation. For the first time, we found that the c[G(2′,5′)U(2′,5′)] showed excellent activity against all five hSTING variants even equivalent to the endogenous ligand c[G(2′,5′)A(3′,5′)]. Furthermore, we have also demonstrated that 3′-3′CDNs with two 3′-5′ phosphodiesters showed higher serum and hydrolase stability than 2′-2′ CDNs with two 2′-5′ phosphodiesters and 2′-3′ CDNs with one 2′-5′ and one 3′-5′ phosphodiester. It is very interesting to note that 2′-2′ CDNs has been found for the first time to show strong activity. These findings will stimulate our exploration for the new functional role of CDNs, and provide guidelines to design CDNs based hSTING targeted drugs.展开更多
基金the Yunnan Provincial Science and Technology DepartmentMajor Science and Technology Special Program(No.202102AE090027-3)the Yunnan Provincial Department of Science and Technology-Kunming Medical University Applied Basic Research Joint Special Project(No.202001AY070001-076)Kunming Medical University Innovation Fund(No.2022S312).
文摘Selenium is an essential nutrient closely related to redox homeostasis in the body.A redox imbalance will adversely affect the microenvironment inside and outside the cell,leading to cell death.Various types of cell death have been discovered in recent years,but the role(s)of selenium and the associated mechanism(s)of action require further elaboration.We review the roles and mechanisms of action of selenium in cell necrosis,apoptosis,ferroptosis,autophagy,and pyroptosis.Under normal conditions,selenium inhibits cell necrosis,apoptosis,ferroptosis,autophagy,and pyroptosis by downregulating the nuclear factorκB pathway,upregulating antiapoptotic proteins,decreasing oxidative stress,increasing antioxidant enzyme activity,enhancing the mTOR pathway,and downregulating the NLRP3/caspase-1 pathway,thereby helping to maintain the normal physiological functions of cells.On the other hand,selenium deficiency leads to activation of the PI3K/AKT and Notch/Hes1 pathways,causing a significant increase in the level of oxidative stress in the organism,resulting in cell necrosis,apoptosis,and pyroptosis.In the case of malignancy,the in vivo metabolite of inorganic selenium,hydrogen selenide,plays an antitumor role by inducing apoptosis and ferroptosis in tumor cells because of its high redox activity.In conclusion,an adequate level of selenium in the body is essential for maintaining normal cellular physiological functions and reducing fibrotic alterations.Furthermore,the in vivo metabolites of inorganic selenium may have some clinical value in antitumor therapy.
基金the National Key Research and Development Program of China(2017YFD0200500)the National Natural Science Foundation of China(21740002,21837001)。
文摘Cyclic dinucleotides(CDNs) are known to activate stimulator of interferon genes(STING) and induce type I interferon responses, therefor possess great potentials to be of immunotherapeutic value for cancers and infectious diseases. However, the existence of different single nucleotide polymorphism(SNP) of human STING(hSTING) gene poses an obstacle to achieve broad-spectrum activation by CDNs. We reported here the design and synthesis of a total of 36 CDNs, representing all structural variations, that contain four bases(A, G, C, U) and two linkage directions(2′-5′-linked and 3′-5′-linked phosphodiester).Through systematic evaluation of IFN-β induction with a dual-luciferase reporter assay, we discovered that wild type hSTING and two isoforms(HAQ and AQ) showed strong response while hSTING-R232 H and R293 Q exhibited the relatively weak response to CDNs stimulation. For the first time, we found that the c[G(2′,5′)U(2′,5′)] showed excellent activity against all five hSTING variants even equivalent to the endogenous ligand c[G(2′,5′)A(3′,5′)]. Furthermore, we have also demonstrated that 3′-3′CDNs with two 3′-5′ phosphodiesters showed higher serum and hydrolase stability than 2′-2′ CDNs with two 2′-5′ phosphodiesters and 2′-3′ CDNs with one 2′-5′ and one 3′-5′ phosphodiester. It is very interesting to note that 2′-2′ CDNs has been found for the first time to show strong activity. These findings will stimulate our exploration for the new functional role of CDNs, and provide guidelines to design CDNs based hSTING targeted drugs.
