Abstract 5666: MyD88 in myofibroblasts regulates aerobic glycolysis-driven hepatocarcinogenesis via ERK-dependent PKM2 nuclear relocalization and activation

Chen

et al. 2022

Preprint

Background aimsThe benefits of hypoxia for maintaining the stemness of cultured human bone marrow-derived endothelial progenitor cells (BM EPCs) have previously been demonstrated but the mechanisms responsible remain unclear. There is growing evidence to suggest a role for cellular metabolism in the regulation of stem cell fate and self-renewal. This study aimed at exploring changes in glucose metabolism and roles in maintaining BM EPCs stemness under hypoxia.MethodsExtracellular flux analysis, LC-MS/MS and 13C tracing HPLC-QE-MS were used to establish EPC metabolic status. Then inhibitors of glucose metabolism were used to assess the impact of the dependent pathways on cell stemness. The key enzymes of glycolysis, tricarboxylic acid cycle (TCA), pentose phosphate pathway (PPP) and mitochondrial respiration were inhibited, and the cell survival rate, clone formation rate, mRNA expression of stemness markers, Nanog, Oct4, Klf4 and Sox2, and adenosine triphosphate (ATP) level were compared.ResultsReprogramming of pathways concerned with glucose metabolism was found under hypoxic conditions, including increased rates of flux through glycolysis and the pentose phosphate pathway (PPP), together with decreased flux through the tricarboxylic acid (TCA) cycle and mitochondrial respiration. We found that inhibiting glycolysis or PPP impaired cell proliferation either under normoxia or hypoxia. Moreover, promoting pyruvate oxidation reverses the maintenance effect of hypoxia on cell stemness. On the contrary, inhibiting pyruvate oxidation, TCA or ETC increased cell stemness under normoxia mimicking hypoxic conditions. Although hypoxia decreased mitochondrial ATP level, the total ATP level remained unchanging, indicating that energy production does not play a major role in this process. ConclusionIn summary, hypoxia induced glucose metabolic reprogramming, and such pattern of metabolic reprogramming maintains the stemness of BM EPCs, and artificial manipulation of cell metabolism can be an effective way for regulating the stemness of BM EPCs.

Section: Discussionmentioning

confidence: 66%

Hypoxia-induced reprogramming of glucose-dependent metabolic pathways maintains the stemness of human bone marrow-derived endothelial progenitor cells

Lin

Chen

et al. 2022

Preprint

“…BP has previously been shown to inhibit ovarian cancer growth and to induce apoptosis of hepatocellular carcinoma cells and human breast cancer cells 35 – 37 . PKM2-IN-1 reduced glucose uptake and lactate production in esophageal and hepatocellular carcinoma cells 38 , 39 and 3PO inhibited growth of lung cancer, breast cancer and promyelocytic leukemia cells 14 . The above findings demonstrate the importance of glycolysis for proliferation of tumor cells.…”

Section: Discussionmentioning

confidence: 97%

Hypoxia-induced reprogramming of glucose-dependent metabolic pathways maintains the stemness of human bone marrow-derived endothelial progenitor cells

Lin

Chen

et al. 2023

Sci Rep

The benefits of hypoxia for maintaining the stemness of cultured human bone marrow-derived endothelial progenitor cells (BM EPCs) have previously been demonstrated but the mechanisms responsible remain unclear. Growing evidences suggest that cellular metabolism plays an important role in regulating stem cell fate and self-renewal. Here we aimed to detect the changes of glucose metabolism and to explore its role on maintaining the stemness of BM EPCs under hypoxia. We identified the metabolic status of BM EPCs by using extracellular flux analysis, LC–MS/MS, and 13C tracing HPLC-QE-MS, and found that hypoxia induced glucose metabolic reprogramming, which manifested as increased glycolysis and pentose phosphate pathway (PPP), decreased tricarboxylic acid (TCA) and mitochondrial respiration. We further pharmacologically altered the metabolic status of cells by employing various of inhibitors of key enzymes of glycolysis, PPP, TCA cycle and mitochondria electron transport chain (ETC). We found that inhibiting glycolysis or PPP impaired cell proliferation either under normoxia or hypoxia. On the contrary, inhibiting pyruvate oxidation, TCA or ETC promoted cell proliferation under normoxia mimicking hypoxic conditions. Moreover, promoting pyruvate oxidation reverses the maintenance effect of hypoxia on cell stemness. Taken together, our data suggest that hypoxia induced glucose metabolic reprogramming maintains the stemness of BM EPCs, and artificial manipulation of cell metabolism can be an effective way for regulating the stemness of BM EPCs, thereby improving the efficiency of cell expansion in vitro.

“…Western blotting was performed as described previously [31]. Brie y, cells and liver tissue samples were collected and lysed in RIPA buffer supplemented with a protease inhibitor cocktail (Solarbio, Beijing, China).…”

Section: Western Blotting Analysismentioning

confidence: 99%

Hepatocyte-specific Smad4 deficiency alleviates liver fibrosis via the p38 / p65 pathway

Wei

Xin

et al. 2022

Preprint

Self Cite

Liver fibrosis is a wound healing response caused by the abnormal accumulation of extracellular matrix, which is produced by activated hepatic stellate cells (HSCs). Most studies have focused on the activated HSCs themselves in liver fibrosis, whether hepatocytes can modulate the process of fibrosis is still unclear. Sma mothers against decapentaplegic homologue 4 (Smad4) is a key intracellular transcription mediator of transforming growth factor-β (TGF-β) during the development and progression of liver fibrosis. However, the role of hepatocyte Smad4 in the development of fibrosis is poorly elucidated. Here, to explore the functional role of hepatocyte Smad4 and the molecular mechanism in liver fibrosis, CCl4-induced liver fibrosis model was established in mice with hepatocyte-specific Smad4 deletion (Smad4Δhep). We found that hepatocyte-specific Smad4 deficiency reduced liver inflammation and fibrosis, alleviated epithelial-mesenchymal transition, and inhibited hepatocyte proliferation and migration. Molecularly, Smad4 deletion in hepatocytes suppressed the expression of inhibitor of differentiation 1 (ID1) and the secretion of connective tissue growth factor (CTGF) of hepatocytes, which subsequently activated the p38 and p65 signaling pathways of HSCs in an epidermal growth factor receptor-dependent manner. Taken together, our results clearly demonstrate that the Smad4 expression in hepatocytes plays important role in promoting liver fibrosis and could therefore be a promising target for future anti-fibrotic therapy.