Search results for "chaperonin"

Hsp60 molecular anatomy and role in colorectal cancer diagnosis and treatment

2011

Quantitative changes in Hsp60 during the development of some tumors suggest that this chaperonin plays a role in carcinogenesis. A description of the specific role(s) of Hsp60 in tumor-cell growth and proliferation is still incomplete, but it is already evident that monitoring its levels and distribution in tissues and fluids has potential for diagnosis and staging, and for assessing prognosis and response to treatment. Although Hsp60 is considered an intramitochondrial protein, it has been demonstrated in the cytosol, cell membrane, vesicles, cell surface, extracellular space, and blood. The knowledge that Hsp60 occurs at all these locations opens new avenues for basic and applied research…

Mitochondrial compartment: a possible target of cadmium effects on breast epithelial cells.

2009

Cadmium–breast epithelial cell interactions were studied by analyzing some mitochondria-related aspects of stress response. We treated immortalized non-tumor breast cells with 5 or 50 μM CdCl2 for 24 or 96 h demonstrating that the exposure did not cause a significant mitochondrial proliferation, while it induced a significant increase in the respiratory activity and mitochondrial polarization. In addition, we found that hsp60 was up-regulated while hsp70 and COXII and COXIV were down-regulated. The mRNA for hsp70 remained constant and only the inducible form of the 70-kDa heat shock protein was over expressed. The mRNAs for COXII and COXIV remained constant after 24 h and increased after lo…

Something old, something new : exploring membrane-containing bacteriophages

2016

2-D difference gel electrophoresis approach to assess protein expression profiles in Bathymodiolus azoricus from Mid-Atlantic Ridge hydrothermal vent…

2011

Hydrothermal vent mussels Bathymodiolus azoricus are naturally exposed to toxic chemical species originated directly from vent chimneys. The amount of toxic elements varies significantly among vent sites along the Mid-Atlantic Ridge and B. azoricus must be able to adapt to changes in hydrothermal fluid composition, temperature and pressure. The aim of this work was to study changes in the proteome in the "gill-bacteria complex" of mussels B. azoricus from three hydrothermal vent sites with distinct environmental characteristics using 2-D Fluorescence Difference Gel Electrophoresis (2-D DIGE). Results showed that 31 proteins had different expression profiles among vent sites and both cluster…

Sea urchin embryos as an in vivo model for the assessment of manganese toxicity: developmental and stress response effects.

2009

In the marine environment increasing concentrations of bio-available compounds often result from anthropogenic activities. Among metal ions, manganese represents a new emergent factor in environmental contamination. Here, we studied the effects of manganese on Paracentrotus lividus sea urchin embryos using biological and biochemical approaches for the analysis of impact on development, tissue accumulation and stress markers. Embryos were continuously exposed from fertilization to manganese at concentrations ranging from 1.0 to 61.6 mg l(-1), monitored for developmental abnormalities at 48 h after fertilization, and used for atomic spectrometric analysis at various times from 6 to 72 h. We f…

GroEL and the maintenance of bacterial endosymbiosis

2004

Many eukaryotic organisms have symbiotic associations with obligate intracellular bacteria. The clonal transmission of endosymbionts between host generations should lead to the irreversible fixation of slightly deleterious mutations in their non-recombinant genome by genetic drift. However, the stability of endosymbiosis indicates that some mechanism is involved in the amelioration of the effects of these mutations. We propose that the chaperone GroEL was involved in the acquisition of an endosymbiotic lifestyle not only by means of its over-production, as proposed by Moran, but also by its adaptive evolution mediated by positive selection to improve the interaction with the unstable endosy…

Adaptive evolution in GroEL from distantly related endosymbiotic bacteria of insects

2005

Many symbioses between bacteria and insects resulted from ancient infections followed by strict vertical transmission within host lineages. The strong bottlenecks under which this transmission occurs promote the neutral fixation of slightly deleterious mutations by genetic drift. As predicted by Muller's ratchet, this fixation will drive endosymbiotic bacteria through an irreversible dynamics of fitness loss. The chaperonin GroEL has been proposed as a compensatory mechanism whereby endosymbiotic bacteria of aphids persist. Here, we show that endosymbiotic bacteria of insects from two phylogenetically very distant bacterial phyla have fixed amino acid substitutions by positive selection in …

Expression of the 60 kDa heat shock protein in normal and inflamed liver.

1993

The 60 kDa heat shock proteins (HSP 60) have been well conserved throughout evolution and are highly immunogenic. Cross-reactivity between bacterial and mammalian HSP 60 is considered a likely mechanism in the pathogenesis of autoimmune diseases. T cell and B cell reactivity to HSP 60 is found in patients with rheumatoid or juvenile arthritis, and the expression of HSP 60 in the inflamed joint is found to be increased. In this study the presence of HSP 60 was demonstrated in normal and inflamed lives. HSP 60 was found to be predominantly expressed in hepatocytes and Kupffer cells, and mainly localized in mitochondria. Heat stress in the form of a 1 h incubation at 42 degrees C increased HSP…

HSP10,HSP70 AND HSP90 IMMUNOHISTOCHEMICAL LEVELS CHANGE IN ULCERATIVE COLITIS AFTER THERAPY

2011

Ulcerative colitis (UC) is a form of inflammatory bowel disease (IBD) characterized by damage of large bowel mucosa and frequent extra-intestinal autoimmune comorbidities. The role played in IBD pathogenesis by molecular chaperones known to interact with components of the immune system involved in inflammation is unclear. We previously demonstrated that mucosal Hsp60 decreases in UC patients treated with conventional therapies (mesalazine, probiotics), suggesting that this chaperonin could be a reliable biomarker useful for monitoring response to treatment, and that it might play a role in pathogenesis. In the present work we investigated three other heat shock protein/molecular chaperones:…

Human HSP10 variants downregulation after cigarette smoke extract exposure in lung cells

2009

The impact of cigarette-smoke stress (a form of oxidative stress) on human lung fibroblasts and epithelial cells, particularly its effect on Hsp10 expression, has not been characterized despite the fact that a role for mitochondrial chaperonins in the development of lung diseases, ranging from chronic obstructive pulmonary disease to bronchial carcinogenesis, has been suggested (1). We studied the effects of non-lethal doses of cigarette smoke extract (CSE) on the expression of Hsp10 in human lung fibroblasts (HFL-1 line) and epithelial cells (16HBE line). Proteomics was carried out using 2D-IPG, silver stain, western blotting, and mass-spectrometry; mRNA was measured by RT-PCR. Database se…