Project description:Mammals display wide range of variation in their lifespan. Investigating the molecular networks that distinguish long- from short-lived species has proven useful to identify determinants of longevity. Here, we compared the liver of long-lived naked mole-rats (NMRs) and the phylogenetically closely related, shorter-lived, guinea pigs using an integrated omic approach. We found that NMRs livers display a unique expression pattern of mitochondrial proteins that result in distinct metabolic features of their mitochondria. For instance, we observed a generally reduced respiration rate associated with lower protein levels of respiratory chain components, particularly complex I, and increased capacity to utilize fatty acids. Interestingly, we show that the same molecular networks are affected during aging in both NMR and humans, supporting a direct link to the extraordinary longevity of both species. Finally, we identified a novel longevity pathway and validated it experimentally in the nematode C. elegans.
Project description:BACKGROUND & AIMS: Metabolic syndrome is a newly identified risk factor for hepatocellular carcinoma (HCC), however the molecular mechanisms still remain unclear. To elucidate this issue, cross-species analysis was performed to compare gene expression patterns of HCC from human patients and melanocortin 4 receptor-knockout (MC4R-KO) mice, developing HCC with obesity, insulin resistance and dyslipidemia. METHODS: Unsupervised hierarchical clustering and principle component analysis of 746 differentially expressed orthologous genes classified HCC of 152 human patients and MC4R-KO mice into two distinct subgroups, one of which included all the mouse HCC was etiologically associated with metabolic risk factors, such as obesity and diabetes. A specific biomarker was identified by the integrative analysis, and validated with in vitro studies and other cohort patients. RESULTS: As commonly overexpressed in human and mouse metabolic disease-associated HCC, FABP4 was remarkably enriched in intratumoral activated hepatic stellate cells (HSCs). Then, we established subclones constitutively expressing FABP4 from a human HSC cell line, in which the expression levels of inflammatory chemokines including IL1A and IL6 was upregulated through NF-κB nuclear translocation. An immunohistochemical validation study of other 106 human HCC samples indicated that FABP4-positive HSCs were distributed in tumors of 38 cases, and that the FABP4-high group was composed of patients with non-viral and non-alcoholic HCC (P=0.027) and with multiple metabolic risk factors (P<0.001) compared with the FABP4-low. CONCLUSIONS: FABP4 overexpression in HSCs could contribute to hepatocellular carcinogenesis in patients with metabolic risk factors via modulation of inflammatory pathway, and is a promising novel biomarker as well as a potential therapeutic target for this subtype of HCC.
Project description:BACKGROUND & AIMS: Metabolic syndrome is a newly identified risk factor for hepatocellular carcinoma (HCC), however the molecular mechanisms still remain unclear. To elucidate this issue, cross-species analysis was performed to compare gene expression patterns of HCC from human patients and melanocortin 4 receptor-knockout (MC4R-KO) mice, developing HCC with obesity, insulin resistance and dyslipidemia. METHODS: Unsupervised hierarchical clustering and principle component analysis of 746 differentially expressed orthologous genes classified HCC of 152 human patients and MC4R-KO mice into two distinct subgroups, one of which included all the mouse HCC was etiologically associated with metabolic risk factors, such as obesity and diabetes. A specific biomarker was identified by the integrative analysis, and validated with in vitro studies and other cohort patients. RESULTS: As commonly overexpressed in human and mouse metabolic disease-associated HCC, FABP4 was remarkably enriched in intratumoral activated hepatic stellate cells (HSCs). Then, we established subclones constitutively expressing FABP4 from a human HSC cell line, in which the expression levels of inflammatory chemokines including IL1A and IL6 was upregulated through NF-κB nuclear translocation. An immunohistochemical validation study of other 106 human HCC samples indicated that FABP4-positive HSCs were distributed in tumors of 38 cases, and that the FABP4-high group was composed of patients with non-viral and non-alcoholic HCC (P=0.027) and with multiple metabolic risk factors (P<0.001) compared with the FABP4-low. CONCLUSIONS: FABP4 overexpression in HSCs could contribute to hepatocellular carcinogenesis in patients with metabolic risk factors via modulation of inflammatory pathway, and is a promising novel biomarker as well as a potential therapeutic target for this subtype of HCC.
Project description:BACKGROUND & AIMS: Metabolic syndrome is a newly identified risk factor for hepatocellular carcinoma (HCC), however the molecular mechanisms still remain unclear. To elucidate this issue, cross-species analysis was performed to compare gene expression patterns of HCC from human patients and melanocortin 4 receptor-knockout (MC4R-KO) mice, developing HCC with obesity, insulin resistance and dyslipidemia. METHODS: Unsupervised hierarchical clustering and principle component analysis of 746 differentially expressed orthologous genes classified HCC of 152 human patients and MC4R-KO mice into two distinct subgroups, one of which included all the mouse HCC was etiologically associated with metabolic risk factors, such as obesity and diabetes. A specific biomarker was identified by the integrative analysis, and validated with in vitro studies and other cohort patients. RESULTS: As commonly overexpressed in human and mouse metabolic disease-associated HCC, FABP4 was remarkably enriched in intratumoral activated hepatic stellate cells (HSCs). Then, we established subclones constitutively expressing FABP4 from a human HSC cell line, in which the expression levels of inflammatory chemokines including IL1A and IL6 was upregulated through NF-κB nuclear translocation. An immunohistochemical validation study of other 106 human HCC samples indicated that FABP4-positive HSCs were distributed in tumors of 38 cases, and that the FABP4-high group was composed of patients with non-viral and non-alcoholic HCC (P=0.027) and with multiple metabolic risk factors (P<0.001) compared with the FABP4-low. CONCLUSIONS: FABP4 overexpression in HSCs could contribute to hepatocellular carcinogenesis in patients with metabolic risk factors via modulation of inflammatory pathway, and is a promising novel biomarker as well as a potential therapeutic target for this subtype of HCC.