Expression analysis of a human hepatic cell line in response to palmitate

Swagell, Christopher D.; Henly, Debra C.; Morris, C. Phillip

doi:10.1016/j.bbrc.2004.12.188

Cited by 28 publications

(30 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3C). A similar effect was seen in Huh-7 cells (a human hepatic cell line), where there was a significant decrease in Bcl-2 gene expression upon 48 h of 0.15 mmol/l palmitate exposure (48). Interestingly, upregulation of at least five oxidative stress response genes involved in the formation of hydroperoxides and lipid peroxides were also observed in these cells.…”

Section: Discussionsupporting

confidence: 63%

Palmitate-Induced Apoptosis in Cultured Bovine Retinal Pericytes

et al. 2005

View full text Add to dashboard Cite

Apoptosis of pericytes (PCs) is an early event in diabetic retinopathy. It is generally thought to be a consequence of sustained hyperglycemia. In keeping with this, long-term (>7 days) incubation of cultured PCs in a high-glucose media has been shown to increase apoptosis. We examine here whether the saturated free fatty acid palmitate, the concentration of which is often elevated in diabetes, has similar effects on cultured PCs. Incubation with 0.4 mmol/l palmitate for 24 h induced both oxidant stress and apoptosis, as evidenced by a sixfold increase in DCF fluorescence and a twofold increase in caspase-3 activation, respectively. NAD(P)H oxidase appeared to be involved in these responses, since overexpression of dominant-negative subunits of NAD(P)H oxidase, such as phox47(DN), diminished oxidant stress, and phox67(DN) and N-17 RAC1(DN) prevented the increase in caspase-3 activity. Likewise, overexpression of vRAC, a constitutively active RAC1, increased caspase-3 activity to the same extent as palmitate alone. The effects of vRAC and palmitate were not additive. In parallel with the increases in oxidative stress, the redox-sensitive transcription factor nuclear factor-B (NF-B) was activated in cells incubated with 0.4 mmol/l palmitate. Furthermore, inhibition of NF-B activation by various means inhibited caspase-3 activation. Finally, incubation with palmitate increased the cellular content of ceramide, a molecule linked to apoptosis and increases in oxidative stress and NF-B activation in other cells. In keeping with such a role, in PCs both coincubation with fumonisin B1 (a ceramide synthase inhibitor) and overexpression of ceramidase I reversed the proapoptotic effect of palmitate. On the other hand, they increased rather than decreased DCF fluorescence. In conclusion, the results suggest that palmitate-induced apoptosis in PCs is associated with activation of NAD(P)H oxidase and NF-B and an increase in ceramide. The precise interactions between these molecules in causing apoptosis and the importance of oxidant stress as a contributory factor remain to be determined.

show abstract

Section: Discussionsupporting

confidence: 63%

Palmitate-Induced Apoptosis in Cultured Bovine Retinal Pericytes

et al. 2005

View full text Add to dashboard Cite

show abstract

“…increased flux from DHAP to lipids, are a direct consequence of the increased TAG synthesis. In general, palmitate and oleate were reported to induce changes in the expression of selected genes involved in β-oxidation and glucose metabolism, but within a longer period of time (16,17). Our results do not indicate significant changes in either of the two pathways under the applied experimental conditions.…”

Section: Discussioncontrasting

confidence: 46%

Central energy metabolism remains robust in acute steatotic hepatocytes challenged by a high free fatty acid load

Niklas¹,

Bonin²,

Mangin³

et al. 2012

BMB Reports

View full text Add to dashboard Cite

Overnutrition is one of the major causes of non-alcoholic fatty liver disease (NAFLD). NAFLD is characterized by an accumulation of lipids (triglycerides) in hepatocytes and is often accompanied by high plasma levels of free fatty acids (FFA). In this study, we compared the energy metabolism in acute steatotic and non-steatotic primary mouse hepatocytes. Acute steatosis was induced by pre-incubation with high concentrations of oleate and palmitate. Labeling experiments were conducted using [U-

show abstract

“…It has been well documented that free fatty acids can have dramatic direct or indirect effects on expression of genes involved in lipid metabolism via regulation of nuclear transcription factors such as the peroxisome proliferator-activated receptors, sterol regulatory elementbinding proteins, liver X receptors, or hepatic nuclear factor (Jump, 2002;Swagell et al, 2005). Although no significant gene expression regulation of peroxisome proliferator-activated receptors (␣, ␤, or ␥) or hepatic nuclear factor 1 was detected, LXRa (203920_at) was underexpressed for all donors, and SREBP1 (202308_at) was underexpressed for donors 1 and 3 only in the monolayer cultures relative to freshly isolated human hepatocytes (data not shown).…”

Section: Genomic Expression In Human Hepatocytesmentioning

confidence: 99%

Gene Expression in Human Hepatocytes in Suspension After Isolation Is Similar to the Liver of Origin, Is Not Affected by Hepatocyte Cold Storage and Cryopreservation, but Is Strongly Changed After Hepatocyte Plating

Richert¹,

Liguori²,

Abadie³

et al. 2006

Drug Metab Dispos

120

View full text Add to dashboard Cite

ABSTRACT:Isolated primary human hepatocytes are a well accepted system for evaluating pharmacological and toxicological effects in humans. However, questions remain regarding how culturing affects the liver-specific functions of the hepatocytes. In addition, cryopreservation could also potentially affect the differentiation state of the hepatocytes. The first aim of the present study was to compare gene expression in freshly isolated primary hepatocytes to that of the liver of origin and to evaluate the expression changes occurring after cryopreservation/thawing, both when maintained in suspension and after plating. The second aim of the present study was to evaluate gene expression in hepatocytes after cold storage of suspensions up to 24 h compared with freshly isolated hepatocytes in suspension. Our results show that the gene expression in freshly isolated human hepatocytes in suspension after isolation is similar to that of the liver of origin. Furthermore, gene expression in primary human hepatocytes in suspension is not affected by hepatocyte cold storage and cryopreservation. However, the gene expression is profoundly affected in monolayer cultures after plating. Specifically, gene expression changes were observed in cultured relative to suspensions of human hepatocytes that are involved in cellular processes such as phase I/II metabolism, basolateral and canalicular transport systems, fatty acid and lipid metabolism, apoptosis, and proteasomal protein recycling. An oxidative stress response may be partially involved in these changes in gene expression. Taken together, these results may aid in the interpretation of data collected from human hepatocyte experiments and suggest additional utility for cold storage and cryopreservation of hepatocytes.The liver serves as the primary site of detoxification of exogenous and endogenous compounds in the systemic circulation. Other biological and physiological functions include the production and secretion of critical blood and bile components, such as albumin, bile salts, and cholesterol. The liver is also involved in protein, steroid, and fat metabolism, as well as vitamin, iron, and sugar storage.One of the most complex functions specific to liver is its ability to metabolize an enormous range of xenobiotics. Many drugs present in the blood are absorbed by hepatocytes, where they can be metabolized via phase I and II biotransformation reactions. Information concerning hepatic drug uptake and metabolism, phase I and phase II induction, drug interactions affecting hepatic metabolism, and hepatotoxicity are essential for the pharmacology and toxicology of a given drug. Because of major species differences both in the catalytic activities and regulation of enzymes involved in drug metabolism, many of these evaluations can only be accurately investigated with human tissue. Because intact cells more closely reflect the environment to which drugs are exposed in the liver, isolated primary human hepatocytes are a well accepted system for evaluating pharmacological and to...

show abstract

Expression analysis of a human hepatic cell line in response to palmitate

Cited by 28 publications

References 32 publications

Palmitate-Induced Apoptosis in Cultured Bovine Retinal Pericytes

Palmitate-Induced Apoptosis in Cultured Bovine Retinal Pericytes

Central energy metabolism remains robust in acute steatotic hepatocytes challenged by a high free fatty acid load

Gene Expression in Human Hepatocytes in Suspension After Isolation Is Similar to the Liver of Origin, Is Not Affected by Hepatocyte Cold Storage and Cryopreservation, but Is Strongly Changed After Hepatocyte Plating

Contact Info

Product

Resources

About