• The CIDE family of proteins includes CIDEA, CIDEB, and CIDEC/Fsp27. The CIDEB gene is most highly expressed in human liver cells, where it has been hypothesized to enable fat buildup by helping enlarge fat-storage structures called "lipid droplets. CIDEB-deficient mice have a lean phenotype with lower levels of plasma TAG, free fatty acids, insulin, and leptin, higher plasma adiponectin, increased whole-body metabolism, and reduced white adipose tissue (WAT) mass. RGC researchers found that individuals with loss-of-function mutations in one copy of the CIDEB gene have about a 53% reduced risk of nonalcoholic liver disease and about a 54% reduced risk of nonalcoholic cirrhosis.
• Gene targeting strategy for B-hCIDEB mice. The exons 1-5 of the mouse Cideb gene that encoded the whole molecule (ATG to STOP codon), including 3’UTR were replaced by human exons 1-7 including 3’UTR in B-hCIDEB mice. The promoter and 5’UTR region of the mouse gene were replaced by human counterparts, while mouse Cideb gene transcription and translation will be disrupted.
• Mouse Cideb mRNA was detectable only in wild-type C57BL/6JNifdc mice. Human CIDEB mRNA was detectable only in homozygous B-hCIDEB mice, but not in wild-type C57BL/6JNifdc mice.

Gene targeting strategy for B-hCIDEB mice. The exons 1-5 of the mouse Cideb gene that encoded the whole molecule (ATG to STOP codon), including 3’UTR were replaced by human exons 1-7 including 3’UTR in B-hCIDEB mice. The promoter and 5’UTR region of the mouse gene were replaced by human counterparts, while mouse Cideb gene transcription and translation will be disrupted.

Species-specific analysis of CIDEB gene expression in wild-type C57BL/6 mice and heterozygous humanized B-hCIDEB mice by RT-PCR. Liver cells were collected from wild-type C57BL/6 mice (+/+) and heterozygous B-hCIDEB mice (H/+). Mouse Cideb mRNA was detectable in wild-type C57BL/6JNifdc mice and heterozygous B-hCIDEB mice. Human CIDEB mRNA was detectable only in heterozygous B-hCIDEB mice, but not in wild-type C57BL/6JNifdc mice.

The inhibitory efficiency of the nucleic acid drugs against human CIDEB in homozygous B-hCIDEB mice. B-hCIDEB mice were randomly divided into four groups (male, 6 weeks old). The human CIDEB-targeted siRNA and control were administered to the mice individually. The mice were sacrificed on day 7 and day 21, and the liver tissues were collected to detect the expression level of human CIDEB mRNA by qPCR. (A) The schematic diagram of experimental processing. (B) The expression of human CIDEB mRNA in the liver. Data was shown as mean ± SEM, analyzed by one way-ANOVA (*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001). Data provided by a client.

In vivo efficacy of the CDAA-HFD induced model in B-hCIDEB mice. (A) The schematic diagram of experimental processing. B-hCIDEB mice were allowed to feed on a normal chow diet from week 0 for two weeks. After that, 6 mice were continually fed with the normal chow diet as the control, and the other mice were fed with the CDAA-HFD diet (60% energy from fat, 0.1% methionine, and deficient in choline, XTMRCD60). The mice in siRNA treatment groups were injected subcutaneously with the saline or AD-1700369-analog (synthesized according to patents) from week 0 once every 2 weeks for 14 weeks.

In vivo efficacy of the CDAA-HFD induced model in B-hCIDEB mice. (A) Body weight of different groups after treatment. (B) Liver weight of different groups after treatment. (C) The liver TG of different groups after treatment. (D) The expression level of human CIDEB mRNA by qPCR. Data was shown as mean ± SEM, analyzed by one way-ANOVA (*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001).

In vivo efficacy of the CDAA-HFD induced model in B-hCIDEB mice. (A), Representative pictures of H&E staining showing degree of NASH. (B) NAFLD activity score (NAS) in different treatment groups. (C) Representative pictures of Sirius Red Staining showing the degree of liver fibrosis. (D) Quantitively positive area of Sirius Red Staining. Data were shown as mean ± SEM, analyzed by one way-ANOVA (*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001).  Scare bar：200μm.

In vivo efficacy of the CDAA-HFD induced model in B-hCIDEB mice. (A), Representative pictures of IHC staining showing F4/80 expression (B) Quantitively positive area of F4/80 expression. (C) Representative pictures of IHC staining showing α-smooth muscle actin (α-SMA) expression (D) Quantitively positive area of α-SMA expression. Data were shown as mean ± SEM, analyzed by one way-ANOVA (*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001).  Scare bar：200μm.