Superoxide-induced changes in endothelin (ET) receptors in hepatic stellate cells

Gabriel, A; Kuddus, Ruhul; Rao, Abdul S.; Watkins, William D.; Gandhi, Chandrashekhar R.

doi:10.1016/s0168-8278(98)80157-8

Cited by 39 publications

(43 citation statements)

References 49 publications

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“…Nonparenchymal cells (NPCs) were prepared by collagenase and protease digestion of the liver, and cultured as described previously. [57][58][59] Stellate cells were separated from the other NPCs by centrifugation on a Nycodenz gradient. 58 Kupffer cells and endothelial cells were separated on a metrizamide gradient, followed by centrifugal elutriation.…”

Section: Western Analysis Of Alr In Hepatic Extracts and Recombinant mentioning

confidence: 99%

“…[57][58][59] Stellate cells were separated from the other NPCs by centrifugation on a Nycodenz gradient. 58 Kupffer cells and endothelial cells were separated on a metrizamide gradient, followed by centrifugal elutriation. 57 Freshly isolated cells were assessed for viability (which was always greater than 95%) with Trypan blue, and were used as such for extraction and analysis of ALR by ELISA.…”

Section: Western Analysis Of Alr In Hepatic Extracts and Recombinant mentioning

confidence: 99%

“…Details of the procedure are described elsewhere. 58 [ 125 I] ALR Binding to Cultured Hepatocytes. rrALR was radioiodinated by a lactoperoxidase procedure, 65 and its purity was determined by fast-protein liquid chromatography (see above) and SDS-polyacrylamide gel electrophoresis.…”

Section: Determination Of Alr Mrna By Reverse-transcriptase Polymerasmentioning

confidence: 99%

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A fresh look at augmenter of liver regeneration in rats

et al. 1999

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Augmenter of liver regeneration (ALR) is a hepatotrophic protein originally identified by bioassay in regenerating rat and canine livers following partial hepatectomy and in the hyperplastic livers of weanling rats, but not in resting adult livers. The ALR gene and gene product were subsequently described, but little is known about the cellular/subcellular sites of ALR synthesis in the liver, or about the release and dissemination of the peptide. To obtain this information in rats, we raised antibodies in rabbits against rat ALR for development of an enzyme-linked immunosorbent assay (ELISA). ALR concentrations were then determined in intact livers of unaltered weanling and adult rats; in regenerating residual liver after partial hepatectomy; in cultured hepatocytes and nonparenchymal cells (NPCs); and in culture medium and serum. ALR in the various liver cells was localized with immunohistochemistry. In addition, hepatic ALR and ALR mRNA were assayed with Western blotting and reversetranscriptase polymerase chain reaction (RT-PCR), respectively. The hepatocyte was the predominant liver cell in which ALR was synthesized and stored; the cultured hepatocytes secreted ALR into the medium in a timedependent fashion. Contrary to previous belief, the ALR peptide and ALR mRNA were present in comparable concentrations in the hepatocytes of both weanling and resting adult livers, as well as in cultured hepatocytes. A further unexpected finding was that hepatic ALR levels decreased for 12 hours after 70% hepatectomy in adult rats and then rose with no corresponding change in mRNA transcripts. In the meantime, circulating (serum) ALR levels increased up to 12 hours and declined thereafter. Thus, ALR appears to be constitutively expressed in hepatocytes in an inactive form, and released from the cells in an active form by unknown means in response to partial hepatectomy and under other circumstances of liver maturation (as in weanling rats) or regeneration. (HEPATOLOGY 1999;29:1435-1445.)The control of hepatic growth and regeneration has interested experimentalists for much of the 20th century. 1 Soon after the classical description in 1931 by Higgins and Anderson 2 of liver regeneration in rats following 70% hepatectomy, a search began for growth factors within the liver itself. McJunkin and Breuhaus 3 observed that the modest mitotic response to a 30% to 40% hepatectomy in rats was enhanced with an intraperitoneal injection 2 days postoperatively of homogenized homologous rat liver. Two decades later, Teir and Ravanti 4 and Blomquist 5 noted that this ''augmentation'' effect was demonstrable only when the injected homogenates were prepared from regenerating liver fragments following hepatectomy or from weanling rat livers that have a naturally heightened mitotic index. Subsequently, LaBrecque and Pesch 6 reported the same prerequisite of a hyperplastic liver source for cytosol extracts containing a putative ''hepatic stimulatory substance'' (HSS).Importantly, however, a cocondition for demonstrating a mitosis-augmenting a...

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Section: Western Analysis Of Alr In Hepatic Extracts and Recombinant mentioning

confidence: 99%

Section: Western Analysis Of Alr In Hepatic Extracts and Recombinant mentioning

confidence: 99%

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A fresh look at augmenter of liver regeneration in rats

et al. 1999

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“…qHSCs were prepared from the livers of male SpragueDawley rats (450-500 g) as described previously (Gabriel et al, 1998;Uemura and Gandhi, 2001). Briefly, following the collagenase/protease digestion of the liver and removal of hepatocytes and cell debris by low speed centrifugation, qHSCs were purified from other non-parenchymal cells by density gradient centrifugation using 13.14% (w/v) Nycodenz, and suspended in Dulbecco's modified Eagle's medium (DMEM) containing 250 units/ml penicillin, 250 mg/ml streptomycin, and 10% fetal bovine serum/10% horse serum.…”

mentioning

confidence: 99%

“…Briefly, following the collagenase/protease digestion of the liver and removal of hepatocytes and cell debris by low speed centrifugation, qHSCs were purified from other non-parenchymal cells by density gradient centrifugation using 13.14% (w/v) Nycodenz, and suspended in Dulbecco's modified Eagle's medium (DMEM) containing 250 units/ml penicillin, 250 mg/ml streptomycin, and 10% fetal bovine serum/10% horse serum. The cells were plated at a density of 0.5 Â 10 6 cells/cm 2 washed after overnight culture and used for experiments, when their purity as determined by vitamin A autofluorescence and immunohistochemical analysis (Gabriel et al, 1998;Uemura and Gandhi, 2001) was greater than 95%. The efficiency of attachment was between 80% and 85%.…”

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Normal rat hepatic stellate cells respond to endotoxin in LBP‐independent manner to produce inhibitor(s) of DNA synthesis in hepatocytes

Thirunavukkarasu

Uemura

Wang

et al. 2005

Journal Cellular Physiology

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Endotoxin is implicated in the pathology of acute liver failure. The mechanisms of its actions on quiescent hepatic stellate cells (qHSCs) and their implications in hepatocyte injury are incompletely understood. We investigated effects of endotoxin (bacterial lipopolysaccharide; LPS) on qHSCs and subsequently on hepatocytes. After overnight culture following their isolation, qHSCs were incubated with or without endotoxin for 24 h. The cells and the culture supernatant were analyzed for cytokines and nitric oxide (NO) synthesis. The effects of qHSC-conditioned media on hepatocytes were then determined. LPS increased inducible NO synthase expression, stimulated NO synthesis, and inhibited DNA synthesis in qHSCs. qHSC-conditioned medium inhibited DNA synthesis in hepatocytes without affecting NO synthesis, while LPS (1-1,000 ng/ml)-conditioned qHSC medium stimulated NO synthesis and caused further inhibition of DNA synthesis and apoptosis. These effects of LPS were more pronounced when qHSCs were incubated with serum, but not with LPS-binding protein (LBP) although CD14 (a receptor for LPS-LBP complex) was found in qHSCs. LPS stimulated the synthesis of TNF-alpha, interleukin (IL)-6, and IL-1beta but not of TGF-beta in qHSCs. Individually or together, L-N(G)-monomethylarginine and antibodies to IL-1beta, IL-6, and TNF-alpha only partly reversed qHSC + LPS-conditioned medium-induced inhibition of DNA synthesis in hepatocytes. These results suggest that the effects of LPS on qHSCs are novel, occurring without the aid of LBP/CD14. They also indicate that other factors, in addition to NO, TGF-beta, TNF-alpha, IL-1beta, and IL-6 are involved in the mechanisms of the growth inhibitory effects of qHSCs on hepatocytes.

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Lecture ‒ Stellate Cells: Do They Have a Role in Portal Hypertension?

Pinzani¹

2001

Portal Hypertension III: Proceedings of the Third Baverno International Consensus Workshop on Definitions, Methodology and Ther

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Superoxide-induced changes in endothelin (ET) receptors in hepatic stellate cells

Cited by 39 publications

References 49 publications

A fresh look at augmenter of liver regeneration in rats

A fresh look at augmenter of liver regeneration in rats

Normal rat hepatic stellate cells respond to endotoxin in LBP‐independent manner to produce inhibitor(s) of DNA synthesis in hepatocytes

Lecture ‒ Stellate Cells: Do They Have a Role in Portal Hypertension?

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