Objective:To investigate the effect of early high-sucrose diet (eHSD) on cognitive function and its regulatory mechanism in 3×Tg-AD mice.Methods:(1) Eighteen specific-pathogen-free (SPF)-grade 2-month-old wide-type (WT) mice were randomly divided into a WT+normal chow diet (NCD) group and a WT+eHSD group, with 9 mice in each group; and 18 SPF-grade 2-month-old 3×Tg-AD mice were randomly divided into a 3×Tg-AD+NCD group and a 3×Tg-AD+eHSD group, with 9 mice in each group. At 2-5 months old, mice in the 4 groups received standard laboratory food+purified water or 30% sucrose water, followed by standard feed for all groups. At 8 months old, cognitive function was assessed by Morris water maze test; fluorescent intensity of AT8 (phosphorylated [p]-tau) and T22 (tau oligomers) in the hippocampal tissues was detected by immunofluorescent staining; concentrations of β-amyloid protein (Aβ) 42 and Aβ 40 were detected by enzyme-linked immunosorbent assay (ELISA); protein expressions of stimulator of interferon genes (STING), TANK-binding kinase 1 (TBK1), p-TBK1, and CCAAT/enhancer-binding protein β (C/EBPβ) were detected by Western blotting; activity of C/EBPβ transcription factor was detected by activity assay; mitochondrial DNA (mtDNA) content in the cytoplasm of cell was detected by real-time quantitative PCR (qPCR). (2) Eighteen SPF-grade 2-month-old 3×Tg-AD mice were randomized into a 3×Tg-AD+eHSD+H-151 group and a 3×Tg-AD+eHSD+dimethyl sulfoxide (DMSO) group, with 9 mice in each group. Mice at 2-5 months old were given standard laboratory food+30% sucrose water; they were, respectively, injected intraperitoneally with STING pathway inhibitor H-151 or DMSO at 5 months old, and continually injected until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, Western blotting and C/EBPβ transcription factor activity experiments were repeated as before. (3) After crossing C/EBPβ heterozygous knockout (C/EBPβ +/-) mice with 3×Tg-AD mice, 3×Tg-AD/C/EBPβ +/- mice were obtained, and 3×Tg-AD mice were used as controls; they were named 3×Tg-AD/C/EBPβ +/-+eHSD group and 3×Tg-AD+eHSD group, with 9 mice in each group. Both groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old, followed by standard feed until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. (4) C/EBPβ transgenic mice (C/EBPβTg) were crossed with 3×Tg-AD mice to obtain C/EBPβTg/3×Tg-AD mice, and Non-Tg/3×Tg-AD mice were used as controls; they were, respectively, named as C/EBPβTg/3×Tg-AD+eHSD+H-151 group, Non-Tg/3×Tg-AD+eHSD+H-151 group, and Non-Tg/3×Tg-AD+eHSD+DMSO group, with 9 mice in each group. All 3 groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old; at 5-8 months old, mice in the C/EBPβTg/3×Tg-AD+eHSD+H-151 group and Non-Tg/3×Tg-AD+eHSD+H-151 group were intraperitoneally injected with H-151, while mice in the Non-Tg/3×Tg-AD+eHSD+DMSO group were injected with DMSO; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. Results:(1) Compared with those in the WT+NCD group and WT+eHSD group, area under the latency curve of 3×Tg-AD+eHSD mice was significantly increased, and proportion of time spending in the targeted quadrant of mice in the 3×Tg-AD+NCD group and 3×Tg-AD+eHSD group was significantly decreased ( P<0.05); compared with that in the 3×Tg-AD+NCD group, proportion of time spending in the targeted quadrant in mice of the 3×Tg-AD+eHSD group was significantly reduced ( P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.076 vs. 2.902±0.399; T22 fluorescent intensity: 1.000±0.145 vs. 2.495±0.273; Aβ 42: 1.000±0.167 vs.1.956±0.132; Aβ 40: 1.000±0.226 vs.1.900±0.116), significantly increased C/EBPβ protein expression and C/EBPβ transcription factor activity (1.000±0.164 vs. 1.804±0.112; 1.000±0.216 vs. 2.743±0.301), and statistically increased mtDNA level detected by D-loop1 and D-loop3 (1.000±0.234 vs. 2.800±0.210; 1.000±0.155 vs. 2.952±0.078; P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.192 vs. 2.093±0.081; p-TBK1/TBK1: 1.000±0.148 vs. 1.561±0.112, P<0.05). (2) Compared with the 3×Tg-AD+eHSD+DMSO group, the 3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers expressions, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.142 vs. 0.538±0.057; T22 fluorescent intensity: 1.000±0.104 vs. 0.665±0.088; Aβ 42: 1.000±0.084 vs. 0.600±0.007; Aβ 40: 1.000±0.138 vs. 0.476±0.083), significantly decreased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.054 vs. 0.468±0.111; p-TBK1/TBK1: 1.000±0.057 vs. 0.598±0.090), and significantly decreased C/EBPβ transcription factor activity (1.000±0.097 vs. 0.445±0.106; P<0.05). (3) Compared with the 3×Tg-AD+eHSD group, the 3×Tg-AD/C/EBPβ +/-+eHSD group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.160 vs. 0.506±0.065; T22 fluorescent intensity: 1.000±0.127 vs. 0.346±0.048; Aβ 42: 1.000±0.017 vs. 0.510±0.101; Aβ 40: 1.000±0.098 vs. 0.586±0.153), and significantly decreased C/EBPβ protein expression (1.000±0.101 vs. 0.568±0.094; P<0.05). (4) Compared with the Non-Tg/3×Tg-AD+eHSD+DMSO group, the Non-Tg/3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, and significantly decreased p-tau and tau oligomers expressions, Aβ 40 concentration in the hippocampus, and the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly decreased STING protein expression and p-TBK1/TBK1 ratio in the hippocampus ( P<0.05). Compared with the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly increased area under the latency curve, significantly decreased proportion of time spending in the targeted quadrant, and significantly increased p-tau and tau oligomers expressions, Aβ 40 and Aβ 42 concentration in the hippocampus ( P<0.05). Conclusion:The eHSD aggravates cognitive impairment in 3×Tg-AD mice through activating cGAS-STING-C/EBPβ pathway.

Hepatitis B virus（HBV）infection poses a significant global health burden，with chronic infection driving progression to cirrhosis，hepatic failure，and hepatocellular carcinoma（HCC）. Mounting evidence implicates immune dysfunction and microbiota dysbiosis as core drivers of disease progression across all HBV infection stages. Gut and tissue-specific microbiota alterations disrupt innate/adaptive immunity，fueling inflammation，immunosuppression，and tumor immune evasion in chronic and end-stage disease. This review synthesizes mechanisms of immune-microbiota interplay in HBV pathogenesis and explores their translational potential for diagnostics and targeted interventions，including microbiota modulation and microbial biomarker applications.

Objective:To investigate the effect of early high-sucrose diet (eHSD) on cognitive function and its regulatory mechanism in 3×Tg-AD mice.Methods:(1) Eighteen specific-pathogen-free (SPF)-grade 2-month-old wide-type (WT) mice were randomly divided into a WT+normal chow diet (NCD) group and a WT+eHSD group, with 9 mice in each group; and 18 SPF-grade 2-month-old 3×Tg-AD mice were randomly divided into a 3×Tg-AD+NCD group and a 3×Tg-AD+eHSD group, with 9 mice in each group. At 2-5 months old, mice in the 4 groups received standard laboratory food+purified water or 30% sucrose water, followed by standard feed for all groups. At 8 months old, cognitive function was assessed by Morris water maze test; fluorescent intensity of AT8 (phosphorylated [p]-tau) and T22 (tau oligomers) in the hippocampal tissues was detected by immunofluorescent staining; concentrations of β-amyloid protein (Aβ) 42 and Aβ 40 were detected by enzyme-linked immunosorbent assay (ELISA); protein expressions of stimulator of interferon genes (STING), TANK-binding kinase 1 (TBK1), p-TBK1, and CCAAT/enhancer-binding protein β (C/EBPβ) were detected by Western blotting; activity of C/EBPβ transcription factor was detected by activity assay; mitochondrial DNA (mtDNA) content in the cytoplasm of cell was detected by real-time quantitative PCR (qPCR). (2) Eighteen SPF-grade 2-month-old 3×Tg-AD mice were randomized into a 3×Tg-AD+eHSD+H-151 group and a 3×Tg-AD+eHSD+dimethyl sulfoxide (DMSO) group, with 9 mice in each group. Mice at 2-5 months old were given standard laboratory food+30% sucrose water; they were, respectively, injected intraperitoneally with STING pathway inhibitor H-151 or DMSO at 5 months old, and continually injected until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, Western blotting and C/EBPβ transcription factor activity experiments were repeated as before. (3) After crossing C/EBPβ heterozygous knockout (C/EBPβ +/-) mice with 3×Tg-AD mice, 3×Tg-AD/C/EBPβ +/- mice were obtained, and 3×Tg-AD mice were used as controls; they were named 3×Tg-AD/C/EBPβ +/-+eHSD group and 3×Tg-AD+eHSD group, with 9 mice in each group. Both groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old, followed by standard feed until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. (4) C/EBPβ transgenic mice (C/EBPβTg) were crossed with 3×Tg-AD mice to obtain C/EBPβTg/3×Tg-AD mice, and Non-Tg/3×Tg-AD mice were used as controls; they were, respectively, named as C/EBPβTg/3×Tg-AD+eHSD+H-151 group, Non-Tg/3×Tg-AD+eHSD+H-151 group, and Non-Tg/3×Tg-AD+eHSD+DMSO group, with 9 mice in each group. All 3 groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old; at 5-8 months old, mice in the C/EBPβTg/3×Tg-AD+eHSD+H-151 group and Non-Tg/3×Tg-AD+eHSD+H-151 group were intraperitoneally injected with H-151, while mice in the Non-Tg/3×Tg-AD+eHSD+DMSO group were injected with DMSO; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. Results:(1) Compared with those in the WT+NCD group and WT+eHSD group, area under the latency curve of 3×Tg-AD+eHSD mice was significantly increased, and proportion of time spending in the targeted quadrant of mice in the 3×Tg-AD+NCD group and 3×Tg-AD+eHSD group was significantly decreased ( P<0.05); compared with that in the 3×Tg-AD+NCD group, proportion of time spending in the targeted quadrant in mice of the 3×Tg-AD+eHSD group was significantly reduced ( P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.076 vs. 2.902±0.399; T22 fluorescent intensity: 1.000±0.145 vs. 2.495±0.273; Aβ 42: 1.000±0.167 vs.1.956±0.132; Aβ 40: 1.000±0.226 vs.1.900±0.116), significantly increased C/EBPβ protein expression and C/EBPβ transcription factor activity (1.000±0.164 vs. 1.804±0.112; 1.000±0.216 vs. 2.743±0.301), and statistically increased mtDNA level detected by D-loop1 and D-loop3 (1.000±0.234 vs. 2.800±0.210; 1.000±0.155 vs. 2.952±0.078; P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.192 vs. 2.093±0.081; p-TBK1/TBK1: 1.000±0.148 vs. 1.561±0.112, P<0.05). (2) Compared with the 3×Tg-AD+eHSD+DMSO group, the 3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers expressions, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.142 vs. 0.538±0.057; T22 fluorescent intensity: 1.000±0.104 vs. 0.665±0.088; Aβ 42: 1.000±0.084 vs. 0.600±0.007; Aβ 40: 1.000±0.138 vs. 0.476±0.083), significantly decreased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.054 vs. 0.468±0.111; p-TBK1/TBK1: 1.000±0.057 vs. 0.598±0.090), and significantly decreased C/EBPβ transcription factor activity (1.000±0.097 vs. 0.445±0.106; P<0.05). (3) Compared with the 3×Tg-AD+eHSD group, the 3×Tg-AD/C/EBPβ +/-+eHSD group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.160 vs. 0.506±0.065; T22 fluorescent intensity: 1.000±0.127 vs. 0.346±0.048; Aβ 42: 1.000±0.017 vs. 0.510±0.101; Aβ 40: 1.000±0.098 vs. 0.586±0.153), and significantly decreased C/EBPβ protein expression (1.000±0.101 vs. 0.568±0.094; P<0.05). (4) Compared with the Non-Tg/3×Tg-AD+eHSD+DMSO group, the Non-Tg/3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, and significantly decreased p-tau and tau oligomers expressions, Aβ 40 concentration in the hippocampus, and the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly decreased STING protein expression and p-TBK1/TBK1 ratio in the hippocampus ( P<0.05). Compared with the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly increased area under the latency curve, significantly decreased proportion of time spending in the targeted quadrant, and significantly increased p-tau and tau oligomers expressions, Aβ 40 and Aβ 42 concentration in the hippocampus ( P<0.05). Conclusion:The eHSD aggravates cognitive impairment in 3×Tg-AD mice through activating cGAS-STING-C/EBPβ pathway.

Hepatitis B virus（HBV）infection poses a significant global health burden，with chronic infection driving progression to cirrhosis，hepatic failure，and hepatocellular carcinoma（HCC）. Mounting evidence implicates immune dysfunction and microbiota dysbiosis as core drivers of disease progression across all HBV infection stages. Gut and tissue-specific microbiota alterations disrupt innate/adaptive immunity，fueling inflammation，immunosuppression，and tumor immune evasion in chronic and end-stage disease. This review synthesizes mechanisms of immune-microbiota interplay in HBV pathogenesis and explores their translational potential for diagnostics and targeted interventions，including microbiota modulation and microbial biomarker applications.