Abstract
Uncoupling protein 1 (UCP1), the mammalian thermogenic mitochondrial protein, is found only in brown adipocytes, but its expression by immunohistochemistry is not homogeneous. Here we present evidence that the non-homogeneous pattern of immunostaining for UCP1 (referred to as the "Harlequin phenomenon") is particularly evident after acute and chronic cold (4C) stimulus and after administration of a specific β3-adrenoceptor agonist (CL316,243). Accordingly, mRNA in situ expression confirmed the UCP1 non-homogeneous pattern of gene activation under conditions of adrenergic stimulus. Furthermore, morphometric analysis of immunogold-stained thin sections showed that UCP1-gold particle density was different among neighboring brown adipocytes with mitochondria of the same size and density. When the adrenergic stimulus was reduced in warm-acclimated animals (28C), UCP1 protein and mRNA expression was reduced and consequently the Harlequin phenomenon was barely visible. These data suggest the existence of an alternative and controlled functional recruitment of brown adipocytes in acute adrenergically stressed animals, possibly to avoid heat and metabolic damage in thermogenically active cells. Of note, the heat shock protein heme oxygenase 1 (HO1) is heterogeneously expressed in adrenergically stimulated brown adipose tissue and, specifically, cells expressing strong immunoreactivity for UCP1 also strongly express HO1.
| Original language | English |
|---|---|
| Pages (from-to) | 21-31 |
| Number of pages | 11 |
| Journal | Journal of Histochemistry and Cytochemistry |
| Volume | 50 |
| Issue number | 1 |
| Publication status | Published - 2002 |
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Keywords
- β-adrenoceptor agonist
- Brown adipose tissue
- Heat shock protein
- Heme oxygenase
- Thermogenesis
- Uncoupling protein 1
ASJC Scopus subject areas
- Anatomy
- Cell Biology
Cite this
CL316,243 and cold stress induce heterogeneous expression of UCP1 mRNA and protein in rodent brown adipocytes. / Cinti, Saverio; Cancello, Raffaella; Zingaretti, Maria Cristina; Ceresi, Enzo; De Matteis, Rita; Giordano, Antonio; Himms-Hagen, Jean; Ricquier, Daniel.
In: Journal of Histochemistry and Cytochemistry, Vol. 50, No. 1, 2002, p. 21-31.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - CL316,243 and cold stress induce heterogeneous expression of UCP1 mRNA and protein in rodent brown adipocytes
AU - Cinti, Saverio
AU - Cancello, Raffaella
AU - Zingaretti, Maria Cristina
AU - Ceresi, Enzo
AU - De Matteis, Rita
AU - Giordano, Antonio
AU - Himms-Hagen, Jean
AU - Ricquier, Daniel
PY - 2002
Y1 - 2002
N2 - Uncoupling protein 1 (UCP1), the mammalian thermogenic mitochondrial protein, is found only in brown adipocytes, but its expression by immunohistochemistry is not homogeneous. Here we present evidence that the non-homogeneous pattern of immunostaining for UCP1 (referred to as the "Harlequin phenomenon") is particularly evident after acute and chronic cold (4C) stimulus and after administration of a specific β3-adrenoceptor agonist (CL316,243). Accordingly, mRNA in situ expression confirmed the UCP1 non-homogeneous pattern of gene activation under conditions of adrenergic stimulus. Furthermore, morphometric analysis of immunogold-stained thin sections showed that UCP1-gold particle density was different among neighboring brown adipocytes with mitochondria of the same size and density. When the adrenergic stimulus was reduced in warm-acclimated animals (28C), UCP1 protein and mRNA expression was reduced and consequently the Harlequin phenomenon was barely visible. These data suggest the existence of an alternative and controlled functional recruitment of brown adipocytes in acute adrenergically stressed animals, possibly to avoid heat and metabolic damage in thermogenically active cells. Of note, the heat shock protein heme oxygenase 1 (HO1) is heterogeneously expressed in adrenergically stimulated brown adipose tissue and, specifically, cells expressing strong immunoreactivity for UCP1 also strongly express HO1.
AB - Uncoupling protein 1 (UCP1), the mammalian thermogenic mitochondrial protein, is found only in brown adipocytes, but its expression by immunohistochemistry is not homogeneous. Here we present evidence that the non-homogeneous pattern of immunostaining for UCP1 (referred to as the "Harlequin phenomenon") is particularly evident after acute and chronic cold (4C) stimulus and after administration of a specific β3-adrenoceptor agonist (CL316,243). Accordingly, mRNA in situ expression confirmed the UCP1 non-homogeneous pattern of gene activation under conditions of adrenergic stimulus. Furthermore, morphometric analysis of immunogold-stained thin sections showed that UCP1-gold particle density was different among neighboring brown adipocytes with mitochondria of the same size and density. When the adrenergic stimulus was reduced in warm-acclimated animals (28C), UCP1 protein and mRNA expression was reduced and consequently the Harlequin phenomenon was barely visible. These data suggest the existence of an alternative and controlled functional recruitment of brown adipocytes in acute adrenergically stressed animals, possibly to avoid heat and metabolic damage in thermogenically active cells. Of note, the heat shock protein heme oxygenase 1 (HO1) is heterogeneously expressed in adrenergically stimulated brown adipose tissue and, specifically, cells expressing strong immunoreactivity for UCP1 also strongly express HO1.
KW - β-adrenoceptor agonist
KW - Brown adipose tissue
KW - Heat shock protein
KW - Heme oxygenase
KW - Thermogenesis
KW - Uncoupling protein 1
UR - http://www.scopus.com/inward/record.url?scp=0036141928&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036141928&partnerID=8YFLogxK
M3 - Article
C2 - 11748291
AN - SCOPUS:0036141928
VL - 50
SP - 21
EP - 31
JO - Journal of Histochemistry and Cytochemistry
JF - Journal of Histochemistry and Cytochemistry
SN - 0022-1554
IS - 1
ER -