NeoHepatocytes From Alcoholics and Controls Express Hepatocyte Markers and Display Reduced Fibrogenic TGF‐β/Smad3 Signaling: Advantage for Cell Transplantation?

Ehnert, Sabrina; Knobeloch, Daniel; Blankenstein, Antje; Müller, Alexandra; Böcker, Ulrich; Gillen, Sonja; Friess, Helmut; Thasler, Wolfgang E.; Dooley, Steven; Nüssler, Andreas K.

doi:10.1111/j.1530-0277.2009.01140.x

Cited by 6 publications

(5 citation statements)

References 39 publications

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“…Furthermore, we have shown that myostatin induces the expression of selected lipogenic genes and increases lipid accumulation in the cultured liver cells. This finding is congruent with the reports that TGFβ1, which shares the type I receptor with myostatin, induces lipogenic gene expression and increases lipid accumulation in liver cells [42], [43].…”

Section: Discussionsupporting

confidence: 92%

“…There was no effect of myostatin on fatty acid oxidation measured in parallel (data not shown). To our knowledge, this is the first report of direct pro-lipogenic effect of myostatin on liver cells, although others have shown that TGFβ1, which shares similar post-receptor signaling pathways with myostatin, increases SCD-1 expression and increases lipid storage in cultured liver cells [42], [43].…”

Section: Resultsmentioning

confidence: 75%

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AAV-Mediated Administration of Myostatin Pro-Peptide Mutant in Adult Ldlr Null Mice Reduces Diet-Induced Hepatosteatosis and Arteriosclerosis

2013

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Genetic disruption of myostatin or its related signaling is known to cause strong protection against diet-induced metabolic disorders. The translational value of these prior findings, however, is dependent on whether such metabolically favorable phenotype can be reproduced when myostatin blockade begins at an adult age. Here, we reported that AAV-mediated delivery of a myostatin pro-peptide D76A mutant in adult mice attenuates the development of hepatic steatosis and arteriosclerosis, two common diet-induced metabolic diseases. A single dose of AAV-D76A in adult Ldlr null mice resulted in sustained expression of myostatin pro-peptide in the liver. Compared to vehicle-treated mice, D76A-treated mice gained similar amount of lean and fat mass when fed a high fat diet. However, D76A-treated mice displayed significantly reduced aortic lesions and liver fat, in association with a reduction in hepatic expression of lipogenic genes and improvement in liver insulin sensitivity. This suggests that muscle and fat may not be the primary targets of treatment under our experimental condition. In support to this argument, we show that myostatin directly up-regulated lipogenic genes and increased fat accumulation in cultured liver cells. We also show that both myostatin and its receptor were abundantly expressed in mouse aorta. Cultured aortic endothelial cells responded to myostatin with a reduction in eNOS phosphorylation and an increase in ICAM-1 and VCAM-1 expression. Conclusions: AAV-mediated expression of myostatin pro-peptide D76A mutant in adult Ldlr null mice sustained metabolic protection without remarkable impacts on body lean and fat mass. Further investigations are needed to determine whether direct impact of myostatin on liver and aortic endothelium may contribute to the related metabolic phenotypes.

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Section: Discussionsupporting

confidence: 92%

Section: Resultsmentioning

confidence: 75%

AAV-Mediated Administration of Myostatin Pro-Peptide Mutant in Adult Ldlr Null Mice Reduces Diet-Induced Hepatosteatosis and Arteriosclerosis

2013

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“…Previous data from our group have shown that during conversion to PCMO the monocytes’ response towards exogenous TGF-β1 is changing with respect to Smad2 and Smad3 activation in such a way that they become sensitive to Smad2C and insensitive to Smad3C phosphorylation [ 32 ]. Given the presence of activin A and TGF-β1 in the culture supernatants and thus the existence of a self-stimulatory/autocrine signaling loop in these cells, we hypothesised that the sensitivity of PCMO to endogenous Smad-activating agents is altered in a similar way.…”

Section: Resultsmentioning

confidence: 99%

Pluripotency Gene Expression and Growth Control in Cultures of Peripheral Blood Monocytes during Their Conversion into Programmable Cells of Monocytic Origin (PCMO): Evidence for a Regulatory Role of Autocrine Activin and TGF-β

Ungefroren¹,

Hyder²,

Hinz³

et al. 2015

PLoS ONE

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Previous studies have shown that peripheral blood monocytes can be converted in vitro to a stem cell-like cell termed PCMO as evidenced by the re-expression of pluripotency-associated genes, transient proliferation, and the ability to adopt the phenotype of hepatocytes and insulin-producing cells upon tissue-specific differentiation. However, the regulatory interactions between cultured cells governing pluripotency and mitotic activity have remained elusive. Here we asked whether activin(s) and TGF-β(s), are involved in PCMO generation. De novo proliferation of PCMO was higher under adherent vs. suspended culture conditions as revealed by the appearance of a subset of Ki67-positive monocytes and correlated with down-regulation of p21WAF1 beyond day 2 of culture. Realtime-PCR analysis showed that PCMO express ActRIIA, ALK4, TβRII, ALK5 as well as TGF-β1 and the βA subunit of activin. Interestingly, expression of ActRIIA and ALK4, and activin A levels in the culture supernatants increased until day 4 of culture, while levels of total and active TGF-β1 strongly declined. PCMO responded to both growth factors in an autocrine fashion with intracellular signaling as evidenced by a rise in the levels of phospho-Smad2 and a drop in those of phospho-Smad3. Stimulation of PCMO with recombinant activins (A, B, AB) and TGF-β1 induced phosphorylation of Smad2 but not Smad3. Inhibition of autocrine activin signaling by either SB431542 or follistatin reduced both Smad2 activation and Oct4A/Nanog upregulation. Inhibition of autocrine TGF-β signaling by either SB431542 or anti-TGF-β antibody reduced Smad3 activation and strongly increased the number of Ki67-positive cells. Furthermore, anti-TGF-β antibody moderately enhanced Oct4A/Nanog expression. Our data show that during PCMO generation pluripotency marker expression is controlled positively by activin/Smad2 and negatively by TGF-β/Smad3 signaling, while relief from growth inhibition is primarily the result of reduced TGF-β/Smad3, and to a lesser extent, activin/Smad2 signaling.

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“…In summary, transplantation of neohepatocytes with excellent quality might help patients suffering from acute or acute-on-chronic liver disease, bridging the time for whole-organ transplantation or support the regeneration of the liver. Recently, we could show that neohepatocytes might have a survival or proliferation advantage compared to primary human hepatocytes due to reduced Smad1 and Smad3 expression (13).…”

Section: Discussionmentioning

confidence: 99%

Autologous Serum Improves Yield and Metabolic Capacity of Monocyte-Derived Hepatocyte-Like Cells: Possible Implication for Cell Transplantation

et al. 2011

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Hepatocyte-transplantation is a therapeutic approach for diverse acute and chronic liver diseases. As availability of primary cells is limited, there is an increasing demand for hepatocyte-like cells (e.g., neohepatocytes generated from peripheral blood monocytes). The aim of this study was to evaluate the effects of six different human AB sera, fetal calf serum, or autologous serum on production of neohepatocytes. The yield and quality of neohepatocytes varied considerably depending on the different sera. Using autologous sera for the whole production process we constantly generated the highest amount of cells with the highest metabolic activity for phase I (e.g., CYP1A1/2, CYP3A4) and phase II enzymes (e.g., glutathione-S-transferase). Moreover, similar effects were seen examining glucose and urea metabolism. Especially, glucose-6-phosphatase and PAS staining showed distinct serum-dependent differences. The role of macrophage activation was investigated by measuring the secretion of TNF-α, TGF-β, and RANKL, MMP activity, as well as mRNA levels of different interleukins in programmable cells of monocytic origin (PCMO). Our data clearly demonstrate that the use of autologous serum reduced initial macrophage activation in PCMOs and subsequently improved both yield and function of differentiated neohepatocytes. The autologous approach presented here might also be useful in other stem cell preparation processes where cell activation during generation shall be kept to a minimum.

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NeoHepatocytes From Alcoholics and Controls Express Hepatocyte Markers and Display Reduced Fibrogenic TGF‐β/Smad3 Signaling: Advantage for Cell Transplantation?

Cited by 6 publications

References 39 publications

AAV-Mediated Administration of Myostatin Pro-Peptide Mutant in Adult Ldlr Null Mice Reduces Diet-Induced Hepatosteatosis and Arteriosclerosis

AAV-Mediated Administration of Myostatin Pro-Peptide Mutant in Adult Ldlr Null Mice Reduces Diet-Induced Hepatosteatosis and Arteriosclerosis

Pluripotency Gene Expression and Growth Control in Cultures of Peripheral Blood Monocytes during Their Conversion into Programmable Cells of Monocytic Origin (PCMO): Evidence for a Regulatory Role of Autocrine Activin and TGF-β

Autologous Serum Improves Yield and Metabolic Capacity of Monocyte-Derived Hepatocyte-Like Cells: Possible Implication for Cell Transplantation

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