Very low density lipoprotein synthesis and secretion by cultured rat hepatocytes.

Davis, Roger J.; Engelhorn, Sheldon C.; Pangburn, Sharon; Weinstein, David; Steinberg, Daniel

doi:10.1016/s0021-9258(17)37758-x

Cited by 226 publications

(10 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All supplements were added according to the recommendations of the manufacturer. Rat hepatocytes were isolated by a collagenase perfusion technique (24) and were plated (8.0 ϫ 10 6 cells/dish) in DMEM/F12 medium containing 20% fetal bovine serum. More than 90% of the cells excluded trypan blue.…”

Section: Measurement Of In Situ Inhibition Of Mtp Activity By Bms-192951 In Hepg2 Cells Mcardle Rh-7777 Cells and Primary Hepatocytesmentioning

confidence: 99%

Evidence that microsomal triglyceride transfer protein is limiting in the production of apolipoprotein B-containing lipoproteins in hepatic cells

Jamil

Chu

Dickson

et al. 1998

Journal of Lipid Research

View full text Add to dashboard Cite

The microsomal triglyceride transfer protein (MTP) is a heterodimeric lipid transfer protein that is required for the assembly and secretion of apolipoprotein B (apoB)-containing lipoproteins. A key unresolved question is whether the MTP-mediated step is rate limiting. To address this, a unique experimental strategy was used that allowed the in situ modulation and measurement of MTP triglyceride transfer activity. In order to accomplish this, an irreversible photoaffinity inhibitor, BMS-192951, was designed and synthesized. When incubated with purified MTP and irradiated with UV light at 360 nm, BMS-192951 inhibits triglyceride transfer by covalently binding to the protein. HepG2 cells were treated with either increasing concentrations of BMS-192951 (0-15 m ) with 5 min of ultraviolet irradiation, or 3.0 m BMS-192951 with various lengths (0-15 min) of ultraviolet irradiation. Microsomal extracts were prepared exhaustively dialyzed to remove unbound inhibitor, and assayed for MTP-mediated triglyceride transfer activity. BMS-192951 was shown to reduce MTP activity in both a dose-and UV exposure time-dependent fashion. Measurement of apoB concentration in the media showed that apoB secretion was reduced in proportion to the in situ inhibition of MTP activity, while no change was observed in apoA-I secretion. Experiments performed in McArdle RH-7777 rat hepatoma cells and primary rat hepatocytes gave nearly identical results; the decrease in apoB secretion was proportional to the decrease in MTP activity. These results indicate that MTP-mediated lipid transfer is limiting in the assembly and secretion of apoB-containing lipoproteins in hepatic cells under the conditions tested.

show abstract

Section: Measurement Of In Situ Inhibition Of Mtp Activity By Bms-192951 In Hepg2 Cells Mcardle Rh-7777 Cells and Primary Hepatocytesmentioning

confidence: 99%

Evidence that microsomal triglyceride transfer protein is limiting in the production of apolipoprotein B-containing lipoproteins in hepatic cells

Jamil

Chu

Dickson

et al. 1998

Journal of Lipid Research

View full text Add to dashboard Cite

show abstract

“…What is the origin of these particles? LP-B:EL2 particles were identified in rat liver perfusates (Dolphin et al, 1978), rat hepatocytes (Davis et al, 1979), and the culture medium of human hepatoma HepG2 cells (Dashti et al, 1985). In hypercholesterolemic rats, cholesterol ester rich lipoproteins containing ApoB and ApoE were identified as the major lipoprotein species in both VLDL and LDL (Noel et al, 1979); deficient in ApoC peptides, these particles were considered to be secretory liver products rather than catabolic remnants of VLDL.…”

Section: Discussionmentioning

confidence: 99%

Selective isolation of human plasma low-density lipoprotein particles containing apolipoproteins B and E by use of a monoclonal antibody to apolipoprotein B

Koren¹,

Alaupovic²,

Lee³

et al. 1987

Biochemistry

View full text Add to dashboard Cite

A monoclonal antibody to human plasma apolipoprotein B was used in a single-step immunoaffinity chromatography procedure to isolate a subpopulation of low-density lipoprotein particles from normolipidemic human plasma. The isolated particles were homogeneous in terms of size (20 nm), flotation coefficient (Sf = 9.5), and electrophoretic mobility (beta band). Their protein moiety consisted of apolipoproteins B and E in a molar ratio close to 2. The lipid moiety consisted of 47.3% cholesterol, 4.7% triglycerides, and 48.0% phospholipids. To indicate its characteristic apolipoprotein composition and hydrated density properties, this family of particles was named LP-B:EL2. In most normolipidemic subjects, LP-B:EL2 particles accounted for less than 10% of the total plasma apolipoprotein B content. The LP-B:EL2 particles bound to the membranes of the human hepatoma HepG2 cells in a specific and saturable manner indicative of receptor-mediated binding. Their binding was significantly higher than that of low-density lipoprotein particles containing only apolipoprotein B.

show abstract

“…Since the protein expression of proliferating cell nuclear antigen, a specific marker of liver regeneration, is maximal at 48 h post-PHx in liver (4-fold higher compared with sham-operated controls) [25], activities of the CL biosynthetic enzymes were determined as described in [26] in hepatocytes isolated from 48 h post-PHx rats. Hepatocytes were prepared 48 h post-PHx or from sham-operated animals using the collagenase perfusion method as described in [27], plated on to 6 cm diameter culture dishes (3×10 6 cells/dish) and then incubated overnight in arginine-free Dulbecco's modified Eagle's medium containing 10 % (v/v) fetal calf serum to select for hepatocytes and allow for full hepatocyte adherence to the dishes. Hepatocytes were then incubated for 24 h in Dulbecco's modified Eagle's medium containing 10 % fetal calf serum.…”

Section: Assay Of Enzymic Activitiesmentioning

confidence: 99%

On the mechanism of the increase in cardiolipin biosynthesis and resynthesis in hepatocytes during rat liver regeneration

Webster

Jiang

Lü

et al. 2005

Biochemical Journal

View full text Add to dashboard Cite

CL (cardiolipin) is a major mitochondrial membrane phospholipid important for the regulation of mitochondrial function. We examined CL de novo biosynthesis and its resynthesis in isolated rat liver hepatocytes prepared 48 h subsequent to two-thirds PHx (partial hepatectomy). The pool size of CL and its de novo biosynthesis from [1,3-(3)H]glycerol were increased 3.3-fold (P<0.05) and 3.1-fold (P<0.05) respectively in hepatocytes prepared from PHx rats compared with sham-operated controls. The reason for the increased CL biosynthesis was a 65% increase (P<0.05) in enzymic activity in PGP-S (phosphatidylglycerolphosphate synthase), a key enzyme in de novo CL biosynthesis. The increase in PGP-S activity was due to a 3-fold increase (P<0.05) of hepatic PGP-S mRNA expression. The increase in de novo CL biosynthesis and pool size corresponded to a 2.3-fold increase (P<0.05) in the amount of [1-14C]linoleic acid incorporated into CL of hepatocytes prepared from PHx rats compared with sham-operated controls, indicating an increase in CL resynthesis. The activity of MLCL-AT (monolysocardiolipin acyltransferase), a rate-limiting enzyme of CL resynthesis, was increased by 43% (P<0.05) in hepatocytes prepared from PHx rats compared with sham-operated controls; this result would explain the increase in [1-14C]linoleic acid incorporation into CL. The increase in MLCL-AT activity was due to an increase in hepatic MLCL-AT protein expression. The results show that CL de novo biosynthesis and its resynthesis are increased during liver regeneration.

show abstract

Very low density lipoprotein synthesis and secretion by cultured rat hepatocytes.

Cited by 226 publications

References 44 publications

Evidence that microsomal triglyceride transfer protein is limiting in the production of apolipoprotein B-containing lipoproteins in hepatic cells

Evidence that microsomal triglyceride transfer protein is limiting in the production of apolipoprotein B-containing lipoproteins in hepatic cells

Selective isolation of human plasma low-density lipoprotein particles containing apolipoproteins B and E by use of a monoclonal antibody to apolipoprotein B

On the mechanism of the increase in cardiolipin biosynthesis and resynthesis in hepatocytes during rat liver regeneration

Contact Info

Product

Resources

About