Objective To investigate the composition ratios and trends of different etiologies after liver biopsy for patients with unexplained liver diseases.Methods A retrospective analysis was performed for the etiology of 960 patients with unexplained liver diseases who were hospitalized and underwent liver biopsy in The Third Affiliated Hospital of Sun Yat-Sen University from January 2011 to December 2020,and the etiologies were categorized by year and age group.The chi-square test was used for comparison of categorical data between multiple groups,and the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple groups.Results There was a tendency of increase in the overall composition ratio of unexplained liver diseases over the past decade.The leading diagnosis after liver biopsy was autoimmune liver disease(AILD)in 306 patients(31.9%),followed by nonalcoholic fatty liver disease(NAFLD)in 95 patients(9.9%)and drug-induced liver disease(DILI)in 82 patients(8.5%),and there were still 320 patients with undetermined causes(33.3%).There were significant differences in sex ratio and median age distribution between the patients with different etiologies(sex ratio:χ2=155.36,P<0.001;median age distribution:H=182.48,P<0.001).AILD had been the leading etiology in 2011-2020,and there was a tendency of reduction in the composition ratio of AILD(χ2=24.40,P<0.001).NAFLD accounted for the highest proportion of 17.6%in the adolescent stage,while AILD accounted for the highest proportion of 17.8%,47.3%,and 56.3%,respectively,in the young,middle-aged,and elderly stages.Conclusion There is a tendency of increase in the composition ratio of unexplained liver diseases in patients undergoing liver biopsy,with AILD being the main disease diagnosed after liver biopsy,followed by NAFLD and DILI,but one-third of the patients still have an unclear etiological diagnosis.

AIM:To identify the expression characteristics of transfer RNA-derived small RNAs(tsRNAs)re-sponding to DNA damage in human hepatoblastoma HepG2 cells,and to investigate their potential functions.METHODS:Based on paired HepG2 cells and TP53 gene knockout HepG2 cells,we successfully constructed a DNA damage cellular model using adriamycin(ADR).Transcriptome analysis of small noncoding RNAs was performed to systematically identi-fy a set of tsRNAs responding to ADR and involved in p53 regulation.Functional enrichment analysis was conducted using the Kyoto Encyclopedia of Genes and Genomes(KEGG).Additionally,after silencing the expression of target tsRNA genes,the biological functions of these tsRNAs in HepG2 cells were initially confirmed through CCK-8 assay and plate colo-ny formation assay.RESULTS:DNA damage induced a set of tsRNAs involved in p53 regulation,among which tRF-5-1(tRF-5_tRNA-Gly-TCC-2-1)and tRF-i-1(tRF i_tRNA-Tyr-GTA-11-1)showed the most significant up-regulation in HepG2 cells(P<0.05).Silencing of either tRF-5-1 or tRF-i-1 gene inhibited the proliferative activity of HepG2 cells(P<0.05).CONCLUSION:A group of tsRNAs responding to DNA damage can be identified in HepG2 cell model,and tsRNAs can promote the proliferative activity of HepG2 cells,suggesting that tsRNAs may play an important role in the de-velopment and progression of liver malignancies.

Objective To investigate the composition ratios and trends of different etiologies after liver biopsy for patients with unexplained liver diseases.Methods A retrospective analysis was performed for the etiology of 960 patients with unexplained liver diseases who were hospitalized and underwent liver biopsy in The Third Affiliated Hospital of Sun Yat-Sen University from January 2011 to December 2020,and the etiologies were categorized by year and age group.The chi-square test was used for comparison of categorical data between multiple groups,and the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple groups.Results There was a tendency of increase in the overall composition ratio of unexplained liver diseases over the past decade.The leading diagnosis after liver biopsy was autoimmune liver disease(AILD)in 306 patients(31.9%),followed by nonalcoholic fatty liver disease(NAFLD)in 95 patients(9.9%)and drug-induced liver disease(DILI)in 82 patients(8.5%),and there were still 320 patients with undetermined causes(33.3%).There were significant differences in sex ratio and median age distribution between the patients with different etiologies(sex ratio:χ2=155.36,P<0.001;median age distribution:H=182.48,P<0.001).AILD had been the leading etiology in 2011-2020,and there was a tendency of reduction in the composition ratio of AILD(χ2=24.40,P<0.001).NAFLD accounted for the highest proportion of 17.6%in the adolescent stage,while AILD accounted for the highest proportion of 17.8%,47.3%,and 56.3%,respectively,in the young,middle-aged,and elderly stages.Conclusion There is a tendency of increase in the composition ratio of unexplained liver diseases in patients undergoing liver biopsy,with AILD being the main disease diagnosed after liver biopsy,followed by NAFLD and DILI,but one-third of the patients still have an unclear etiological diagnosis.

AIM:To identify the expression characteristics of transfer RNA-derived small RNAs(tsRNAs)re-sponding to DNA damage in human hepatoblastoma HepG2 cells,and to investigate their potential functions.METHODS:Based on paired HepG2 cells and TP53 gene knockout HepG2 cells,we successfully constructed a DNA damage cellular model using adriamycin(ADR).Transcriptome analysis of small noncoding RNAs was performed to systematically identi-fy a set of tsRNAs responding to ADR and involved in p53 regulation.Functional enrichment analysis was conducted using the Kyoto Encyclopedia of Genes and Genomes(KEGG).Additionally,after silencing the expression of target tsRNA genes,the biological functions of these tsRNAs in HepG2 cells were initially confirmed through CCK-8 assay and plate colo-ny formation assay.RESULTS:DNA damage induced a set of tsRNAs involved in p53 regulation,among which tRF-5-1(tRF-5_tRNA-Gly-TCC-2-1)and tRF-i-1(tRF i_tRNA-Tyr-GTA-11-1)showed the most significant up-regulation in HepG2 cells(P<0.05).Silencing of either tRF-5-1 or tRF-i-1 gene inhibited the proliferative activity of HepG2 cells(P<0.05).CONCLUSION:A group of tsRNAs responding to DNA damage can be identified in HepG2 cell model,and tsRNAs can promote the proliferative activity of HepG2 cells,suggesting that tsRNAs may play an important role in the de-velopment and progression of liver malignancies.