| Trypanosoma is a group of parasites in the protozoan phylum that live in the blood of many animals,among which the two main types that can cause human diseases are Trypanosoma brucei and Trypanosoma cruzi.Trypanosoma brucei is mainly transmitted through the bite of the vector tsetse flies and can cause sleeping sickness in humans,Nagana disease in wild animals and livestock,mainly cattle,posing a great threat to human health and livestock development.At present,trypanosomes are becoming resistant to their therapeutic drugs,but the development of new drugs and vaccines against trypanosomiasis has been slow due to high research and development costs and low returns.Nanomaterials have been a hot topic of research in recent years,and it has been reported in the literature that the nanomaterial graphene has inhibitory effects on certain parasites.Graphene quantum dots,as derivatives of graphene-based materials,have been effective in antibacterial and inhibition of Trypanosoma brucei,but the inhibitory effect of graphene quantum dots on Trypanosoma brucei has not been reported so far.Therefore,it is important to study the inhibitory effect and mechanism of graphene quantum dots on Trypanosoma brucei for the development of new drugs.To investigate the inhibitory effect of graphene quantum dots on Trypanosoma brucei,firstly,graphene quantum dots were synthesized and characterized,and the viability and apoptosis of Trypanosoma brucei were examined.The results showed that graphene quantum dots inhibited the viability and induced the apoptosis of Trypanosoma brucei.Secondly,the mechanism of apoptosis in Trypanosoma brucei was explored by measuring apoptotic indicators such as reactive oxygen species,mitochondrial membrane potential,calcium ions,ATP and cell cycle.The results show that graphene quantum dots can be endocytosed into the body by Trypanosoma brucei through the clathrin-dependent pathway,triggering a series of apoptotic responses,including elevated intracellular reactive oxygen levels,mitochondrial dysfunction,intracellular calcium ion accumulation,impaired ATP synthesis,cell cycle arrest,and DNA fragmentation.Meanwhile,the changes of subcellular organelles of Trypanosoma brucei after co-incubation with graphene quantum dots were examined.The results showed that the subcellular organelles of Trypanosoma brucei underwent different degrees of damage after co-incubation with graphene quantum dots,including loss of mitochondrial membrane,blurred nuclear membrane,dilated perinuclear gap,and swelling of Golgi apparatus and endoplasmic reticulum.So does the defect of organelle structure involve endoplasmic reticulum stress and mitochondrial pathway? Therefore,the expression of t SNAP42,a protein of the splicing-primed RNA silencing pathway in endoplasmic reticulum stress,and Endo G,a nucleic acid endonuclease,were examined.The results showed that elevated expression of protein t SNAP42 produced endoplasmic reticulum stress;elevated expression of Endo G in mitochondria indicated that it translocated to the nucleus and sheared DNA,thus inducing apoptosis.To further investigate the causes of Trypanosoma brucei apoptosis induced by graphene quantum dots,a transcriptomic study was conducted.Enrichment analysis found that after the graphene quantum dots were co-incubated with Trypanosoma brucei,the glycolysis/gluconeogenesis pathway and pentose phosphate pathway related to energy metabolism,glycerol metabolism pathway related to lipid peroxidation and glutathione metabolism pathway related to redox were enriched.To sum up,we believe that graphene quantum dots damaged the subcellular organelles of Trypanosoma brucei,affected the energy metabolism of Trypanosoma brucei,induced oxidative stress,and led to the continuous accumulation of reactive oxygen species in Trypanosoma brucei thus causing apoptosis in Trypanosoma brucei.The results of this study lay a theoretical foundation for the role of graphene quantum dots in the development of new anti-trypanosome drugs. |
PDF Full Text Request