Generation Of A Hutchinson-Gilford Progeria Syndrome Monkey Model By Base Editing

How to resist aging and prolong life is an enduring topic in human development history.Aging can be divided into normal aging and pathological aging.In pathological aging,Hutchinson-Gilford progeria syndrome(HGPS),a rare genetic disease with single base mutation,has been the focus of researchers.The pathogenic principle of HGPS is that a conversation of cytosine to thymine at position 1824,located in the coding region of the LMNA gene responsible for encoding nuclear lamina protein on human chromosome1.As a key component of the nucleus,nuclear lamina plays an important role in maintaining cellular structure,mitosis and chromosome agglutination.The mutation of LMNA(c.1824 C >T)leads to the splicing of lamin A/C m RNA,which results in the accumulation of toxic progerin protein and ultimately causes the HGPS diseases.Meanwhile,the mutation of LMNA(c.357-2A>G)causes deletion of exon 2 of LMNA gene and causes dilated cardiomyopathy(DCM)disease.Genetically,nonhuman primate and human have a high genetic similarity,therefore,successful generation of non-human primate disease models can facilitate studies of genetic disease pathogenesis.As a derivative of the CRISPR/Cas9(Clustered regularly interspaced short palindromic repeats/Cas9)system,base editors consist of nick Cas9 enzymes(n Cas9)and deaminases.Base editors can be divided into two categories,Cytosine base editors(CBEs)can convert cytosine to thymine while adenine base editors(ABEs)can convert adenine to guanine.Comparing with the traditional way of introducing base mutation by homologous recombination,base editing has advantages of easy operation and high efficiency.In this study,we generated two Macaca fascicularis embryo models HGPS(c.1824 C >T)and DCM(c.357-2A >G)targeted to LMNA gene by microinjecting CBE or ABE respectively.Subsequently,we obtained five HGPS monkeys which contain the LMNA(c.1824 C >T)mutation.We confirmed the expression of abnormally the spliced LMNA RNA and the resultant toxic progerin protein in multiple tissues of HGPS monkeys.The HGPS monkeys appeared normal at birth.However,they gradually showed alopecia,skeletal system aberrations,and growth stagnation.Histopathological analysis confirmed skin aging,abnormal fat metabolism and early symptoms of atherosclerosis.Transcriptomic analysis showed that up-regulated differential genes of HGPS monkeys mainly focused on immune response and cytokine signaling pathway.Compared with previously reported HGPS models,our HGPS monkey mirrors HGPS patients more comprehensively and highly.To sum up,this study confirms the feasibility of base editing in generation of nonhuman primate disease model.Moreover,the HGPS monkey will provide a powerful platform for studying and treating the HGPS.