Search results for " CHAPERONES."

Does SARS-CoV-2 Trigger Stress-InducedAutoimmunity by Molecular Mimicry? A Hypothesis.

2020

Viruses can generate molecular mimicry phenomena within their hosts. Why shouldsevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) not be considered one of these?Information in this short review suggests that it might be so and, thus, encourages research aimingat testing this possibility. We propose, as a working hypothesis, that the virus induces antibodiesand that some of them crossreact with host’s antigens, thus eliciting autoimmune phenomena withdevasting consequences in various tissues and organs. If confirmed, by in vitro and in vivo tests,this could drive researchers to find effective treatments against the virus.

The Mitochondrial Targeting Chaperone 14-3-3ε Regulates a RIG-I Translocon that Mediates Membrane Association and Innate Antiviral Immunity

2012

SummaryRIG-I is a cytosolic pathogen recognition receptor that initiates immune responses against RNA viruses. Upon viral RNA recognition, antiviral signaling requires RIG-I redistribution from the cytosol to membranes where it binds the adaptor protein, MAVS. Here we identify the mitochondrial targeting chaperone protein, 14-3-3ε, as a RIG-I-binding partner and essential component of a translocation complex or “translocon” containing RIG-I, 14-3-3ε, and the TRIM25 ubiquitin ligase. The RIG-I translocon directs RIG-I redistribution from the cytosol to membranes where it mediates MAVS-dependent innate immune signaling during acute RNA virus infection. 14-3-3ε is essential for the stable inte…

Nerve growth factor and epidermal growth factor stimulate clusterin gene expression in PC12 cells

1999

Clusterin (apolipoprotein J) is an extracellular glycoprotein that might exert functions in development, cell death and lipid transport. Clusterin gene expression is elevated at sites of tissue remodelling, such as differentiation and apoptosis; however, the signals responsible for this regulation have not been identified. We use here the clusterin gene as a model system to examine expression in PC12 cells under the control of differentiation and proliferation signals produced by nerve growth factor (NGF) and by epidermal growth factor (EGF) respectively. NGF induced clusterin mRNA, which preceded neurite outgrowth typical of neuronal differentiation. EGF also activated the clusterin mRNA, …

A multipronged approach to unveil the emerging role of Hsp60 in chronic obstructive pulmonary disease

2011

Inflammation is a major component of chronic obstructive pulmonary disease (COPD) and its cause and mechanisms are still incompletely understood. For example, the role of heat shock proteins (Hsps), many of which are molecular chaperones, has not been explored in detail in COPD, despite the fact that these molecules are known to participate in inflammation in other diseases. It has been shown that extracellular Hsps can signal certain types of T cells, macrophages, dendritic cells, and neutrophils and, thereby, elicit inflammation and immunity. However, these phenomena have not been investigated in COPD despite: a) the increasing awareness of Hsp participation in inflammation and immunity; …

Study of the effects of Pleurotuseryngii var. eryngii on heat shock proteins and cytokines levels in a mouse model of colon carcinoma

Medicinal mushrooms are wonderful source of nutraceuticals with a wide range of benefit for human health. The current anti-cancer therapy is not always target specific and often is associated with complications for patients. Therefore new effective and less toxic therapeutic approaches are needed. Heat shock proteins (Hsps) are highly expressed in a variety of cancer types contributing to tumor cell propagation. Here, we treated C26 colon cancer cells with a cold-water extracts of an edible mushrooms Pleurotuseryngii var. eryngii (Pleuery). Hsp90, 70, 60 and 27 levels were measured by western blotting and immunofluorescence analysis. Moreover, we evaluated Pleueryanti cancer effect in an an…

Higher plants possess two different types of ATX1-like copper chaperones.

2007

Abstract Copper (Cu) chaperones constitute a family of small Cu+-binding proteins required for Cu homeostasis in eukaryotes. The ATX1 family of Cu chaperones specifically delivers Cu to heavy metal P-type ATPases. The plant Arabidopsis thaliana expresses the ATX1-like Cu chaperone CCH, which exhibits a plant-specific carboxy-terminal domain (CTD) with unique structural properties. We show that CCH homologues from other higher plants contain CTDs with structural properties similar to Arabidopsis CCH. Furthermore, we identify a new ATX1-like Cu chaperone in Arabidopsis, AtATX1, which functionally complements yeast atx1Δ and sod1Δ associated phenotypes, and localizes to the cytosol of Arabidop…

Extracellular heat shock proteins in cancer: From early diagnosis to new therapeutic approach

2021

In cancer, human cells lose the ability to properly control the series of events that occur constantly during cell growth and division, including protein expression, stability, and dynamics. Heat shock proteins (Hsps) are key molecules in these events, constitutively expressed at high levels and could furthermore be induced by the response to cancer-induced stress. In tumor cells, Hsps have been shown to be implicated in the regulation of apoptosis, immune responses, angiogenesis and metastasis; in some cases, they can be overexpressed and dysregulated, representing important cancer hallmarks. In the past few years, it has been demonstrated that Hsps can be released by tumor cells through s…

ROLE OF HEME OXYGENASE-1 (HSP32) AND HSP90 IN GLIOBLASTOMA

2017

Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. The current treatment regimes for glioblastoma demonstrated a low efficiency and offer a poor prognosis. Advancements in conventional treatment strategies have only yielded modest improvements in overall survival. The heat shockproteins, heme oxygenase-1 (HO-1) and Hsp90, serve these pivotal roles in tumor cells and have been identified as effective targets for developing therapeutics. This topic review summarizes the current preclinical and clinical evidences and rationale to define the potential of HO-1 and Hsp90 in GBM progression and chemoresistance.

Exosomal HSP60 levels and related miRNAs in brain tumors

In cancer, Extracellular Vesicles (EVs), such as exosomes, contribute to tumor progression by regulating local and systemic parameters. Since exosomes are released into body fluids, they may be used in nanomedicine as a valuable source of diagnostic biomarkers. The prognosis of brain tumors is poor even after surgical resection followed by post-operatory chemo- and radio-therapies and it is cogent to find innovative treatments. The discovery that molecular chaperones can be determinant factors in tumorigenesis and the increasing understanding of exosomes, particularly in what refers to their release by tumor cells and contents, including chaperones and miRNA, provide elements to develop nov…

The molecular anatomy of human Hsp60 and its effects on Amyloid-β peptide

Heat Shock Protein 60 (HSP60) is ubiquitous and highly conserved, being present in eukaryotes and prokaryotes, including pathogens. This chaperonin is typically considered a mitochondrial protein but it is also found in other intracellular sites, extracellularly and in circulation. HSP60 is an indispensable component of the Chaperoning System and plays a key role in protein quality control, preventing off-pathway folding events and refolding misfolded proteins. This makes HSP60 a putative therapeutic agent for neurodegenerative diseases associated with aggregation of misfolded proteins, for example, Alzheimer’s Disease. We produced and purified recombinant human HSP60 and investigated the e…