Hsp60 expression, new locations, functions, and perspectives for cancer diagnosis and therapy

Hsp60 in eukaryotes is considered typically a mitochondrial chaperone (also called Cpn60) but in the last few years it has become clear that it also occurs in the cytosol, the cell surface, the extracellular space, and in the peripheral blood. Studies with prokaryotic models have shown that Hsp60 plays a role in assisting nascent polypeptides to reach a native conformation, and that it interacts with Hsp10 (which also resides in the mitochondria and is also named Cpn10). In addition to its role in polypeptide folding in association with Hsp10, other functions and interacting molecules have been identified for Hsp60 in the last several years. Some of these newly identified functions are associated with carcinogenesis, specifically with tumor cell survival and proliferation. Thus, assessing the levels of Hsp60 in tumor cells and in sera of cancer patients is becoming an attractive area of investigation aiming at the development of means for practical applications in clinical oncology. Since Hsp60 participates in extracellular molecular interactions and cell signalling and also in key intracellular pathways of some types of tumor cells, the idea of using Hsp60 in anti-cancer therapy (chaperonotherapy) is being investigated. The Hsp could be used either as an anticancer agent alone or in combination with tumor antigens, or as target for anti-chaperone compounds. In this article, a brief review is presented of representative research efforts aimed at assessing Hsp60 in a variety of tumors with the purpose of illustrating possible implications and applications for making early and differential diagnoses, assessing prognosis, monitoring response to treatment, and for developing novel anti-cancer strategies

ROLE OF CHAPERONES IN HEALTHY BOWEL AND IBD.

The chaperoning system is the wole complement of chaperones, co-chaperones and chaperone cofactors of the body that preserves cell and tissue homeostasis. Its structural and/or functional defects can cause pathologic conditions, nemed chaperonopathies. Large bowel homeostasis includes a healthy status of the mucosal tissues and the microbiota. An alteration of one of them may determine, in turn, modifications of the other. Molecular chaperones of bacteria and human origin have been implicated in inflammatory bowel disease (IBD). In IBD chaperone levels usually increase and their cellular and subcellular loclization change. This is considered a physiological stress-response of mucosal cells to inflammation. However, chaperones also play active roles in IBD pathogenesis, e.g. perpetuate inflammation. Therefore, IBD can be classified among the chaperonopathies. This classification opens the door to the design and application of new forms of treatment targeting the chaperones, namely chaperonopathy

Changes in immunohistochemical levels and subcellular localization after therapy and correlation and colocalization with CD68 suggest a pathogenetic role of Hsp60 in ulcerative colitis.

In an earlier work, the role of heat shock protein (Hsp60) in the pathogenesis of ulcerative colitis (UC) was suggested by its significant increase in the pathological mucosa parallel with an increase in inflammatory cells. More data in this direction are reported in this work. We analyzed by immunohistochemistry biopsies of colon tissue from 2 groups of patients with UC and treated with either 5-aminosalicylic acid (5-ASA) alone or in combination with a probiotic. We looked for inflammatory markers and Hsp60. Both the treatments were effective in reducing symptoms but the group treated with both 5-ASA and probiotics showed better clinical results. Amelioration of symptoms was associated with reduction of both inflammation and Hsp60, a reduction that was most marked in the group treated with 5-ASA and probiotics. The levels of Hsp60 positively correlated with those of CD68-positive cells, and double immunofluorescence showed a high index of colocalization of the chaperonin and CD68 in lamina propria. Immunoelectron microscopy showed thatHsp60Fclassically a mitochondrial proteinFwas abundantly also present in cytosol in biopsies taken at the time of diagnosis, but not after the treatment. Our data suggest that Hsp60 is an active player in pathogenesis of UC and it can be hypothesized that the chaperonin is responsible, at least in part, for initiation and maintenance of disease

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

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; and b) the fact that this disease is waiting for new knowledge to benefit from effective treatment and continues to be one of the commonest and most serious illnesses in the Western countries. We developed a strategy to study Hsps in COPD involving a multipronged approach, using in vivo and in vitro methods, which would, at least in part, compensate for the limitations inherent to the analysis of human diseases. We determined the levels of six Hsps in bronchial mucosa biopsies, as well as several inflammatory markers, from patients at various stages compared to smoker and non-smoker controls by immunohistochemistry, and found significant increase of Hsp60, Hsp10, and Hsp40 in COPD but no changes for Hsp27, Hsp70 and Hsp90. We also found that the increase in Hsp60 positively correlated with number of neutrophils, and it localized in them. Hsp60 has been implicated in human inflammatory pathology; hence it was pertinent to investigate whether the chaperonin originated only in the neutrophils or also in other cells. In vitro experiments showed that in bronchial epithelial cells submitted to oxidative stress, a characteristic of COPD mucosa, Hsp60 was overexpressed and was released into the extracellular medium. Other measurements indicated that NFkB-p65 was involved in the hsp60-gene upregulation whereas HSF-1 apparently was not. All the data we obtained using a battery of complementary in vivo and in vitro methods coincided to indicate that Hsp60 plays an active role in inflammation in COPD. Hence, one can infer that the chaperonin does contribute to the etiology and/or pathogenesis of COPD and that it is pertinent to investigate this aspect of Hsp60 biology-COPD pathology with renewed intensity. The results could have a significant impact on the developing of strategies for diagnosis, determining prognosis, and treatment that should be centered on Hsp60

Hsp60 and heme oxygenase-1 (Hsp32) in acute myocardial infarction

Heat shock proteins (Hsps) are produced in response to various stressors, including ischemia-reperfusion, and they can exit cells and reach the blood. In this pilot study, we determined serum levels of Hsp60 and heme-oxygenase-1 (HO-1; also named Hsp32) in subjects with acute myocardial infarction (AMI) to assess their clinical significance and potential prognostic value. We also performed a bioinformatics analysis of the 2 molecules in search of structural clues on the mechanism of their release from cells. We studied 40 patients consecutively admitted for AMI (male:female patient ratio=20:20, mean age: 64 ± 13 years) and 40 matched controls. A blood sample was drawn for biochemical analyses within 24 h of symptoms onset, and Hsp60 and HO-1 concentrations were determined by enzyme-linked immunosorbent assay (ELISA). All patients were followed up for 6 months to register adverse post-AMI cardiovascular events. A multivariate analysis demonstrated that elevated Hsp60 (P=0.0361), creatine phosphokinase-muscle brain (CK-MB) (P=0.0446), and troponin (P=0.0490) were predictive of post-AMI adverse events. In contrast, increased HO-1 showed a significant association with less severity of coronary artery diseases (P=0.0223). These findings suggest that Hsp60 and HO-1 play distinct roles in the pathogenesis of AMI and subsequent AMI-related pathology. The possibility that these proteins differ in their roles and mechanisms of action in AMI and post-AMI pathology was supported also by the bioinformatics estimates of probability of their localization in various subcellular compartments. The results clear the way for subsequent investigation on the pathogenetic role and clinical significance of Hsp60 and HO-1 in AMI

Archaea on human skin

The recent era of exploring the human microbiome has provided valuable information on microbial inhabitants, beneficials and pathogens. Screening efforts based on DNA sequencing identified thousands of bacterial lineages associated with human skin but provided only incomplete and crude information on Archaea. Here, we report for the first time the quantification and visualization of Archaea from human skin. Based on 16 S rRNA gene copies Archaea comprised up to 4.2% of the prokaryotic skin microbiome. Most of the gene signatures analyzed belonged to the Thaumarchaeota, a group of Archaea we also found in hospitals and clean room facilities. The metabolic potential for ammonia oxidation of the skin-associated Archaea was supported by the successful detection of thaumarchaeal amoA genes in human skin samples. However, the activity and possible interaction with human epithelial cells of these associated Archaea remains an open question. Nevertheless, in this study we provide evidence that Archaea are part of the human skin microbiome and discuss their potential for ammonia turnover on human skin