Heat shock protein (HSP) expression and proliferation of tubular cells in end stage renal disease with and without haemodialysis

Heat shock proteins and kidney disease: perspectives of HSP therapy

Heat shock proteins (HSPs) mediate a diverse range of cellular functions, prominently including folding and regulatory processes of cellular repair. A major property of these remarkable proteins, dependent on intracellular or extracellular location, is their capacity for immunoregulation that optimizes immune activity while avoiding hyperactivated inflammation. In this review, recent investigations are described, which examine roles of HSPs in protection of kidney tissue from various traumatic influences and demonstrate their potential for clinical management of nephritic disease. The HSP70 class is particularly attractive in this respect due to its multiple protective effects. The review also summarizes current understanding of HSP bioactivity in the pathophysiology of various kidney diseases, including acute kidney injury, diabetic nephropathy, chronic glomerulonephritis, and lupus nephritis-along with other promising strategies for their remediation, such as DNA vaccination.

Killer cell immunoglobulin receptor profile on CD4(+) CD28(-) T cells and their pathogenic role in non-dialysis-dependent and dialysis-dependent chronic kidney disease patients

There is a progressive increase in cardiovascular disease with declining renal function, unexplained by traditional risk factors. A CD4(+) T-cell subpopulation (CD4(+)  CD28(-) ), activated by human heat-shock protein 60 (hHSP 60), expands in patients with acute coronary syndrome and is associated with vascular damage. These cells exhibit cytotoxicity via expression of activating killer cell-immunoglobulin-like receptor KIR2DS2, mainly in the absence of inhibitory KIR2DL3. We investigated expansion of these cells and the pathogenic role of the KIR in non-dialysis-dependent chronic kidney disease (NDD-CKD) and end-stage haemodialysis-dependent renal disease (HD-ESRD) patients. CD4(+)  CD28(-) cells were present in 27% of the NDD-CKD and HD-ESRD patients (8-11% and 10-11% of CD4(+) compartment, respectively). CD4(+)  CD28(-) cells were phenotyped for KIR and DAP12 expression. Cytotoxicity was assessed by perforin and pro-inflammatory function by interferon-γ expression on CD4(+)  CD28(-) clones (NDD-CKD n = 97, HD-ESRD n = 262). Thirty-four per cent of the CD4(+)  CD28(-) cells from NDD-CKD expressed KIR2DS2 compared with 56% in HD-ESRD patients (P = 0·03). However, 20% of clones expressed KIR2DL3 in NDD-CKD compared with 7% in HD-ESRD patients (P = 0·004). DAP12 expression in CD28(-)  2DS2(+) clones was more prevalent in HD-ESRD than NDD-CKD (92% versus 60%; P < 0·001). Only 2DS2(+)  2DL3(-)  DAP12(+) clones were cytotoxic in response to hHSP 60. CD4(+)  CD28(-) cells exhibited increased KIR2DS2, reduced KIR2DL3 and increased DAP12 expression in HD-ESRD compared with NDD-CKD patients. These findings suggest a gradual loss of expression, functionality and protective role of inhibitory KIR2DL3 as well as increased cytotoxic potential of CD4(+)  C28(-) cells with progressive renal impairment. Clonal expansion of these T cells may contribute to heightened cardiovascular events in HD-ESRD.

Keratin 18 and heat-shock protein in chronic kidney disease

Chronic kidney disease (CKD) is an affliction associated with increased systemic stress and cell death. We will review the role of keratin 18 (K-18) and caspase-cleaved CK-18 (ccK-18) as markers for increased apoptosis and necrosis during renal failure progression. The importance of preventative expression of heat-shock proteins (HSPs) in response to cell stress will also be discussed. The frequent development of CKD leads to serious complications. The potential of use of K-18 and HSP as early biomarkers of renal failure will be reviewed. Also, the role of these proteins with respect to dialysis regimes and in acute ischemic kidney injury following renal transplantation will be discussed.

Angiogenesis in renal cell carcinoma: correlation of microvessel density and microvessel area with other prognostic factors

This study was aimed at evaluating the association between tumor vascularity and other known prognostic factors in different histopathological subtypes of renal cell carcinoma (RCC). In 41 cases of RCC, immunohistochemistry was performed using anti-CD34 antibody and Ki-67 (MIB-1). Microvessel density was estimated in an area of 0.23 mm(2) representative of the highest microvessel density ("hot spot"). The microvessel area (MVA) was expressed as percentage of total tumor area occupied by vessels. Endothelial proliferation index (EPI) was determined from sections stained by Ki-67. The relationship between MVD, MVA, EPI and prognostic parameters of RCC like stage, grade and tumor cells proliferation index (TPI) was evaluated. The tumor MVA increased significantly with the higher stage of the tumor (P < 0.001) and increase in TPI (P < 0.05). The MVD, however, did not show significant correlation with grade and stage of the tumor. Microvessel area appears to be a better prognostic marker for RCC when compared to microvessel density. The increase in MVA, without increase in MVD, with increasing stage may be due to the development of larger diameter vascular channels in higher-stage tumors, and this is thought to facilitate metastasis.

Controlled delivery of heat shock protein using an injectable microsphere/hydrogel combination system for the treatment of myocardial infarction

Myocardial infarction causes a high rate of morbidity and mortality worldwide, and heat shock proteins as molecular chaperones have been attractive targets for protecting cardiomyoblasts under environmental stimuli. In this study, in order to enhance the penetration of heat shock protein 27 (HSP27) across cell membranes, we fused HSP27 with transcriptional activator (TAT) derived from human immunodeficiency virus (HIV) as a protein transduction domain (PTD). We loaded the fusion protein (TAT-HSP27) into microsphere/hydrogel combination delivery systems to control the release behavior for prolonged time periods. We found that the release behavior of TAT-HSP27 was able to be controlled by varying the ratio of PLGA microspheres and alginate hydrogels. Indeed, the released fusion protein maintained its bioactivity and could recover the proliferation of cardiomyoblasts cultured under hypoxic conditions. This approach to controlling the release behavior of TAT-HSP27 using microsphere/hydrogel combination delivery systems may be useful for treating myocardial infarction in a minimally invasive manner.

Computer based receptogram approach: an objective way of assessing immunohistochemistry of androgen receptor staining and its correlation with hormonal response in metastatic carcinoma of prostate

AIMS

To categorise the immunostaining heterogeneity of androgen receptors in metastatic carcinoma of the prostate using a pattern oriented approach and to correlate the results with response to hormonal treatment.

METHODS

Paraffin wax embedded tumour sections from 85 patients with metastatic carcinoma of the prostate were processed for immunocytochemistry and stained for the androgen receptor using antiandrogen receptor antibodies. A computer based image analysis system was used to analyse the pattern of nuclear immunostaining in a minimum of 500 nuclei/slide. Depending on the nuclear receptor content and concentration, receptogram patterns were established for each specimen. The receptogram pattern was correlated with clinical response to hormonal treatment.

RESULTS

Clinical response to hormonal treatment was documented using prostate specific antigen as the marker into responders (good, fair, stable) and non-responders. Forty four of 48 patients who responded to hormonal treatment had type 1 (35) or type 3 (nine) receptograms, which are characterised by a unimodal peak or multimodal peaks within a narrow concentration range. Thirteen of the 18 patients who stabilised had type 1 or type 3 receptograms. Seventeen of the 19 patients who did not respond to hormonal treatment had either type 2 or type 4 receptograms, which are characterised by skewed or bimodal androgen receptor distribution. Positive and negative predictive values of receptograms were 96.5% and 63%, respectively.

CONCLUSIONS

Image analysis of androgen receptor immunostaining with a receptogram oriented approach provides important prognostic information that can be used to predict response to hormone treatment in patients with metastatic carcinoma of the prostate.