Phenotypic profiles of cultured glomerular cells following repeated cycles of hydrocarbon injury

Texas A&M University, College Station, Texas, United States
Kidney International (Impact Factor: 8.56). 05/2000; 57(4):1571-80. DOI: 10.1046/j.1523-1755.2000.01001.x
Source: PubMed


The glomerulus has been implicated as a target of hydrocarbon injury in vitro and in vivo. In the present studies, the phenotypic profiles of cultured rat glomerular cells (GCs) following repeated cycles of hydrocarbon injury were evaluated. Cultured GCs were incubated for 24 hours with benzo[a]pyrene (BaP; 3 micromol/L), a prototypical polycyclic aromatic hydrocarbon, and were allowed to recover overnight before two additional cycles of chemical challenge during serial propagation in vitro. At the end of this regimen, control cultures were characterized by predominance of fusiform cells that grew in "hills and valleys," while GCs subjected to hydrocarbon injury displayed an epithelial morphology characterized by a rounded, polygonal shape clearly distinct from that normally exhibited by glomerular mesangial cells (GMCs) in culture.
Indirect immunofluorescent detection of cell markers was conducted to identify cells of mesenchymal or epithelial origin. Measurements of DNA synthesis and cell number were performed to determine proliferative capacities of the different cell types in response to hydrocarbon challenge.
Immunofluorescence studies revealed that control GC cultures contained mostly alpha-smooth muscle (SM) actin-positive cells, with a few (5.1% +/- 2.6) E-cadherin-positive cells occasionally identified. In contrast, BaP-treated cultures exhibited a mixed cell population in which E-cadherin-positive cells were predominant (66.6% +/- 4.1). Single-cell cloning of naive cultures of GCs yielded four clones, three of which exhibited a fusiform morphology and were alpha-SM actin positive (SCC 1 through SCC 3) and one (SCC 4E) that exhibited epithelial characteristics similar to those found in hydrocarbon-treated cultures. Immunofluorescence studies showed that epithelial cells in hydrocarbon-treated cultures, as well as SCC 4E-derived clones, were vimentin positive and cytokeratin negative, characteristics similar to glomerular visceral epithelial cells (GVECs). DNA synthesis and cell proliferation in clone SCC 1 were decreased following acute BaP challenge, while growth rates in SCC 4E-derived clones were unaffected by hydrocarbon injury. Repeated cycles of hydrocarbon challenge in clonal populations yielded different profiles of DNA synthesis, with significant decreases in SCC 1 and no changes in SCC 4E.
These observations suggest that hydrocarbon injury induces differential responses in cells of the glomerulus, resulting in inhibition of GMCs and selective growth advantage of GVECs. These alterations are reminiscent of critical events described in the pathogenesis of focal segmental glomerulosclerosis and raise important questions about the pathogenesis of hydrocarbon-induced nephropathies.

Download full-text


Available from: Alan R Parrish, Apr 07, 2015
6 Reads
  • Source
    • "Benzo(a)pyrene (B(a)P), a polycyclic aromatic hydrocarbon , is a byproduct of combustion that causes renal injury and elicits a nephropathic response. Renal toxicity in rodents is often induced by B(a)P treatment (Alejandro et al., 2000). Subchronic oral BaP dosing increased cast formation in Sprague Dawley rats (Knuckles et al., 2001). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Evidence from epidemiological, experimental and clinical trial data indicates that a plant based diet can reduce the risk of chronic diseases and reduces toxic effects. In the present study, we report the antioxidant and anticlastogenic activity of Pluchea lanceolata (PL), an important medicinal plant, in both in vitro and in vivo model. Benzo(a)pyrene (B(a)P) administration leads to depletion of renal glutathione and its metabolizing enzymes. Pretreatment with PL (100 and 200 mg /kg b.wt) restored renal glutathione content and its dependent enzymes significantly (p<0.001) with simultaneous increase in catalase(CAT), quinone reductase(QR) in mouse kidney. Prophylactic administration of PL prior to B (a) P administration significantly decreased the malondialdehyde(MDA), H2O2 and xanthineoxidase (XO) levels at a significance of p<0.001, at both the doses. PL extract pretreated groups showed marked inhibition in B(a)P induced micronuclei formation in mouse bone marrow cells with simultaneous restoration of DNA integrity, viz. alkaline unwinding assay and DNA damage shown by gel-electrophoresis. HPTLC confirms the presence of quercetin in plant extract which could be responsible for PL protecting efficacy. In conclusion, the present findings strongly support the antioxidant efficacy of PL, possibly by modulation of antioxidant armory.
    Interdisciplinary toxicology 03/2013; 6(1):47-54. DOI:10.2478/intox-2013-0009
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cardiovascular diseases (CVD) are the leading cause of death in both males and females in the United States, and are classified into four major forms: coronary heart disease (CHD), cerebrovascular disease (stroke), hypertensive disease (high blood pressure), and rheumatic fever/rheumatic heart disease. Over 70 million Americans (1 in 4) have one or more types of cardiovascular disease, and in 2002, 38% of all deaths in the U.S. were attributed to cardiovascular diseases, equal to 1 of every 2.6 deaths. In fact, fatalities due to cardiovascular diseases each year are about equal to the next five leading causes of death combined: cancer, chronic lower respiratory diseases, accidents, diabetes mellitus, and pneumonia/influenza. Based on age-adjusted statistics, cardiovascular disease targets 34.3% of male and 32.4% of female non-Hispanic whites; 41.1% of male and 44.7% of female non-Hispanic blacks; and 29.2% of male and 29.3% of female Mexican Americans. According to the Centers for Disease Control and National Center for Health Statistics (CDC/NCHS), if all forms of major cardiovascular diseases were eliminated, life expectancy of the U.S. population would rise by almost 7 years.
    01/1970: pages 159-210;
Show more