c-Fos In Areas Research Articles

Intermittent High-Fat Diet Intake Reduces Sensitivity to Intragastric Nutrient Infusion and Exogenous Amylin in Female Rats.

Intermittent (INT) access to a high-fat diet (HFD) can induce excessive-intake phenotypes in rodents. This study hypothesized that impaired satiation responses contribute to elevated intake in an INT-HFD access model. First, this study characterized the intake and meal patterns of female rats that were subjected to an INT HFD in which a 45% HFD was presented for 20 hours every fourth day. To examine nutrient-induced satiation, rats received intragastric infusions of saline or Ensure Plus prior to darkness-onset food access. A similar design was used to examine sensitivity to the satiating effect of amylin. This study then examined whether an INT HFD influences amylin-induced c-Fos in feeding-relevant brain areas. Upon INT HFD access, rats consumed meals of larger size. The anorexic response to intragastric Ensure infusion and exogenous amylin treatment was blunted in INT rats on both chow-only and INT-HFD days of the diet regimen, compared with chow-maintained and continuous-HFD rats. An INT HFD did not influence amylin-induced c-Fos in the area postrema, nucleus of the solitary tract, and lateral parabrachial nucleus. Impaired satiation responses, mediated in part by reduced sensitivity to amylin, may explain the elevated intake observed upon INT HFD access and may play a role in disorders of INT overconsumption, including binge eating.

Identification of the proto-oncogene c-fos in areas of periprosthetic osteolysis around loosened hip prostheses

Identification of the proto-oncogene c-fos in areas of periprosthetic osteolysis around loosened hip prostheses

Identification of the proto-oncogene c-fos in areas of periprosthetic osteolysis around loosened hip prostheses

Expression of the proto-oncogene c-fos was investigated by in situ hybridization and a study of the immunohistochemistry of the interfacial membranes surrounding the femoral component of failed cementless total hip arthroplasty (THA). The values of the proto-oncogene c-fos gene and protein were high in these interfacial membranes. High expression of the c-fos gene and protein was observed in the macrophage-like cells and fibroblast-like cells. However, there was little expression in multinucleated giant cells. We demonstrated the significance of the proto-oncogene c-fos in interfacial membranes – the first report of c-fos in total joint replacement failure.

Cellular distribution of c-Jun and c-Fos in rat lung before and after bleomycin induced injury.

C-Jun and c-Fos transcription factors have been associated with enhanced cellular proliferation. We studied their cellular distribution in normal and fibrotic rat lung. Pulmonary fibrosis was induced by intratracheal administration of bleomycin. In normal rat lung, c-Jun and c-Fos are present in alveolar macrophages and type II pneumocytes, in the bronchiolar epithelium and in smooth muscle cells of bronchioli and blood vessels. Subcellular fractionation of proteins revealed a predominant presence of both c-Jun and c-Fos in the heavy membrane fraction containing mitochondria and secretory granules. This was confirmed by immunoelectron microscopy, which also revealed a different localization of c-Jun and c-Fos in different cell types. Whereas in type II pneumocytes and in macrophages cytoplasmic c-Jun and c-Fos is associated with mitochondria, in Clara cells of the bronchial epithelium only secretory granules contain c-Jun and c-Fos. In addition, c-Jun is strongly present in the nuclear fraction. In the fibrotic rat lung c-Jun and c-Fos are located in the same cell types as in control lungs. In addition, fibroblasts contain c-Jun and c-Fos in areas of proliferation whereas in areas of complete fibrosis there is only a very weak expression of c-Jun and c-Fos.

Regional expression of c-fos antigen in the basal forebrain following intraventricular infusions of angiotensin and its modulation by drinking either water or saline

The expression of c-fos protein was examined in the basal forebrains of male rats 60 min following intracerebroventricular infusions of 250 pmol angiotensin II. Levels of corticosterone and vasopressin were also measured at the same time point. In animals not allowed access to water after infusion, angiotensin II induced intense c-fos expression in a band of neurons extending throughout the anterior region of the third ventricle region, including the organum vasculosum of the lamina terminalis, the median preoptic nucleus (nucleus medianus) and the subfornical organ. There were also high levels of expression in the hypothalamic supraoptic nucleus and the paraventricular nucleus, particularly its lateral (magnocellular) region, though other, parvicellular areas were also affected. No other area of the hypothalamus was altered. There was increased c-fos expression in the central nucleus of the amygdala and the bed nucleus of the stria terminalis. Allowing rats to drink during the 60-min survival period modified this pattern of response, c-fos was markedly reduced in the supraoptic nucleus and the paraventricular nucleus but not in the other areas examined, including the anterior region of the third ventricle and the amygdala. When water was withheld for 15min, but then allowed, rats drank the same total volume but c-fos expression was no longer inhibited in either the supraoptic nucleus or paraventricular nucleus. When rats were given 0.9% saline to drink, they ingested about three times as much as water, but angiotensin II-induced c-fos expression was similar to that in rats denied access to water. The pattern was similar following access to 1.8% saline, though levels in the organum vasculosum of the lamina terminalis were reduced. There was a marked correlation between the number of c-fos -positive neurons in the supraoptic nucleus or paraventricular nucleus and plasma levels of corticosterone 60 min after infusion, but not with arginine-vasopressin levels.These experiments show that angiotensin II induces highly localized expression of c-fos in areas known to be concerned with the dipsogenic and endocrine actions of this peptide, and that this pattern is selectively altered by allowing the animal to drink solutions of different tonicity. Immediate-early gene expression is a novel and valuable method of determining the neural response to peptides at the cellular level.