PROGRESS STUDY: Progression of chronic kidney disease in children and heat shock proteins.

Various molecular and cellular processes are involved in renal fibrosis, such as oxidative stress, inflammation, endothelial cell injury, and apoptosis. Heat shock proteins (HSPs) are implicated in the progression of chronic kidney disease (CKD). Our aim was to evaluate changes in urine and serum HSP levels over time and their relationships with the clinical parameters of CKD in children. In total, 117 children with CKD and 56 healthy children were examined. The CKD group was followed up prospectively for 24 months. Serum and urine HSP27, HSP40, HSP47, HSP60, HSP70, HSP72, and HSP90 levels and serum anti-HSP60 and anti-HSP70 levels were measured by ELISA at baseline, 12 months, and 24 months. The urine levels of all HSPs and the serum levels of HSP40, HSP47, HSP60, HSP70, anti-HSP60, and anti-HSP70 were higher at baseline in the CKD group than in the control group. Over the months, serum HSP47 and HSP60 levels steadily decreased, whereas HSP90 and anti-HSP60 levels steadily increased. Urine HSP levels were elevated in children with CKD; however, with the exception of HSP90, they decreased over time. In conclusion, our study demonstrates that CKD progression is a complicated process that involves HSPs, but they do not predict CKD progression. The protective role of HSPs against CKD may weaken over time, and HSP90 may have a detrimental effect on the disease course.

Ultrabright plasmonic fluor nanolabel-enabled detection of a urinary ER stress biomarker in autosomal dominant tubulointerstitial kidney disease.

Autosomal dominant tubulointerstitial kidney disease (ADTKD)-uromodulin (UMOD) is the most common nonpolycystic genetic kidney disease, but it remains unrecognized due to its clinical heterogeneity and lack of screening test. Moreover, the fact that the clinical feature is a poor predictor of disease outcome further highlights the need for the development of mechanistic biomarkers in ADTKD. However, low abundant urinary proteins secreted by thick ascending limb cells, where UMOD is synthesized, have posed a challenge for the detection of biomarkers in ADTKD-UMOD. In the CRISPR/Cas9-generated murine model and patients with ADTKD-UMOD, we found that immunoglobulin heavy chain-binding protein (BiP), an endoplasmic reticulum chaperone, was exclusively upregulated by mutant UMOD in the thick ascending limb and easily detected by Western blot analysis in the urine at an early stage of disease. However, even the most sensitive ELISA failed to detect urinary BiP in affected individuals. We therefore developed an ultrasensitive, plasmon-enhanced fluorescence-linked immunosorbent assay (p-FLISA) to quantify urinary BiP concentration by harnessing the newly invented ultrabright fluorescent nanoconstruct, termed "plasmonic Fluor." p-FLISA demonstrated that urinary BiP excretion was significantly elevated in patients with ADTKD-UMOD compared with unaffected controls, which may have potential utility in risk stratification, disease activity monitoring, disease progression prediction, and guidance of endoplasmic reticulum-targeted therapies in ADTKD.NEW & NOTEWORTHY Autosomal dominant tubulointerstitial kidney disease (ADTKD)-uromodulin (UMOD) is an underdiagnosed cause of chronic kidney disease (CKD). Lack of ultrasensitive bioanalytical tools has hindered the discovery of low abundant urinary biomarkers in ADTKD. Here, we developed an ultrasensitive plasmon-enhanced fluorescence-linked immunosorbent assay (p-FLISA). p-FLISA demonstrated that secreted immunoglobulin heavy chain-binding protein is an early urinary endoplasmic reticulum stress biomarker in ADTKD-UMOD, which will be valuable in monitoring disease progression and the treatment response in ADTKD.

Cross talk between Hsp72, HMGB1 and RAGE/ERK1/2 signaling in the pathogenesis of bronchial asthma in obese patients.

BACKGROUND: The incidence of obesity-related asthma has shown a remarkable increase. OBJECTIVES: We aimed to explore the role of heat shock protein 72 (Hsp72) and receptor for advanced glycation end products (RAGE) axis with its downstream signaling in the pathogenesis of obesity-related asthma. METHODS: We enrolled a total of 55 subjects and divided them into three groups. Groups I and II included healthy, normal weight (n = 15) and obese (n = 15) subjects, respectively. Twenty-five obese asthmatics (group III) were subdivided into group IIIa (10 patients with mild to moderate asthma) and group IIIb (15 patients with severe asthma). High mobility group box 1 (HMGB1), interleukin 8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), and urinary Hsp72 were immunoassayed. Hydrogen peroxide (H2O2) and free fatty acids (FFAs) levels were photometrically measured. RAGE mRNA expression was relatively quantified by real-time PCR. RESULTS: We found significant elevations of serum HMGB1, IL-8, MCP1, ERK1/2, FFAs, and H2O2 levels as well as urinary Hsp72 levels in obese subjects compared to healthy control. These were more evident in patients with severe asthma (group IIIb). Multivariate regression analysis identified Hsp72 and ERK1/2 as independent predictors of bronchial asthma severity. Receiver operating characteristic (ROC) curve analysis revealed that areas under the curve (AUC) for Hsp72 and ERK1/2 were 0.991 and 0.981, respectively, which denotes a strong predictive value for identifying the severity of bronchial asthma in obese patients. CONCLUSION: The current study highlights the role of Hsp72 and HMGB1/RAGE/ERK1/2 signaling cascade in the pathogenesis of bronchial asthma and its link to obesity, which could be reflected on monitoring, severity grading, and management of this disease.

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.

Stress proteins and cytokines are urinary biomarkers for diagnosis and staging of bladder cancer.

BACKGROUND: Cancer often involves inflammatory processes. We hypothesized that immune mediators in urine may serve as biomarkers for bladder cancer (BCa). OBJECTIVE: To investigate whether BCa might be marked by urinary levels of heat shock proteins (HSPs; HSP60, HSP70, or HSP90) or cytokines (interferon [IFN]-γ, tumor necrosis factor [TNF]-α, tumor growth factor [TGF]-ß, interleukin [IL]-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, or IL-13). DESIGN, SETTING, AND PARTICIPANTS: This was a case-control study with a discovery and validation phase. We examined urine from 106 consecutive patients: healthy controls (n=18); hematuria with no evidence of BCa (n=20); non-muscle-invasive BCa (n=50); and muscle-invasive BCa (n=18). The concentrations of HSPs and cytokines were assessed by enzyme-linked immunosorbent assay. In the validation phase, independent urine samples from 40 patients were analyzed (controls [n=19] and BCa [n=21]). MEASUREMENTS: We used the area under the curve (AUC) of a receiver operating characteristic analysis to determine the ability of HSPs and cytokines to mark BCa and applied a multivariate logistic regression to create a formula able to diagnose BCa. The formula was applied to the validation set without recalculation, and positive and negative predictive values were calculated. RESULTS AND LIMITATIONS: Urinary concentrations of IL-8, IL-10, and IL-13 were significantly elevated in BCa; IL-13 was the most prominent marker (AUC: 0.93; 95% confidence interval [CI], 0.85-0.99). The multivariate regression analysis highlighted HSP60 (odds ratio [OR]: 1.206; 95% CI, 1.041-1.397, p=0.003) and IL-13 (OR: 1.020; 95% CI: 1.007-1.033, p=0.012). The validation assay was performed using HSP60 and IL-13. The overall positive predictive value was 74% (95% CI, 64-84%); and the negative predictive value was 76% (95% CI, 66-86%). Since we examined a small number of patients, the results need to be confirmed in a larger cohort. CONCLUSIONS: These results suggest that it might be possible to develop a urinary biomarker for BCa and raise the possibility that expression of anti-inflammatory cytokines and HSPs might allow BCa to evade immune surveillance.

Relationship between bone mineral density and syndrome types described in traditional chinese medicine in chronic obstructive pulmonary disease: a preliminary clinical observation.

Osteoporosis is a common finding following chronic obstructive pulmonary disease (COPD), but there are few reports on the relationship between bone mineral density (BMD) and the syndrome types described in traditional Chinese medicine (TCM) in patients with COPD. A cross-sectional medical survey was used in this study. Twenty-six male patients with COPD and 26 age-matched male healthy subjects were recruited. The symptom questionnaire survey of TCM was implemented, and thereafter the COPD patients were divided into two subgroups: type of deficiency of the lung and spleen (TDLS) and type of deficiency of the lung, spleen and kidney (TDLSK). BMD of lumbar spine (L2-4), non-dominant femoral neck (Neck), Ward's triangle (Ward's), and great trochanter (Troch) were measured by dual-energy x-ray absorptiometry. In addition, the other bone turnover markers were also examined. The results showed that BMD was much more decreased in TDLSK than that in TDLS patients (p < 0.05), and BMD in the patients of the TDLS subgroup without symptoms of kidney-vacuity has showed the decreased trend from healthy subjects to TDLS patients. Furthermore, there was a higher incidence of osteoporosis in patients with TDLSK compared with that in TDLS (p < 0.05, OR > 2.0). Therefore, the data suggest that: (1) BMD might be a marker more sensitive than the symptom for the diagnosis of kidney-vacuity in COPD patients; (2) the deficiency of kidney would be the key factor of bone mineral loss; and (3) that invigorating the kidney should be performed in the phase of TDLS in COPD patients in advance.

Urinary heat shock protein-72 excretion in clinical and experimental renal ischemia.

Renal ischemia not only causes injury but also induces repair mechanisms, such as the cellular induction of the 72-kilodalton heat shock protein HSP-72. The aim of this study was to determine whether HSP-72 is excreted in urine after ischemic renal injury. The first urine of six pediatric allograft recipients was examined for proteinuria and urinary HSP-72 excretion. Sprague-Dawley rats were treated with renal ischemia or hyperthermia and renal cortex and urinary HSP-72 levels were determined. HSP-72 was excreted in the first urine of renal allografts. In rats, renal HSP-72 was induced both by renal ischemia or hyperthermia. However, only renal ischemia resulted in urinary excretion of HSP-72. Urinary excretion of HSP-72 indicates an increased renal stress response and loss of tubular cell integrity after clinical and experimental renal ischemia.