Expression of Hsp70 in kidney cells exposed to ochratoxin A

Ochratoxin A (OTA) is a possible etiological agent of endemic nephropathy, a chronic renal disease with high prevalence in limited geographic areas. Ochratoxicosis has many characteristics of different pathological states in which heat shock proteins (Hsps) are usually induced. The most inducible heat shock proteins belong to the Hsp70 family. We determined the level of expression of Hsp70 by the Western blot analysis in kidneys of rats treated with low doses of OTA and in LLC-PK1 and MDCK cells exposed to OTA. Estimation of cell viability and release of lactate dehydrogenase (LDH) confirmed the toxic effects of OTA on cultured cells. OTA affects the relative distribution of two Hsp70 isoforms (68-kDa and 74-kDa isoforms), but does not change total amount of Hsp70 in rat kidney. No changes in the Hsp70 level were detected in LLC-PK1 and MDCK cells treated with OTA, although the cells were seriously injured, as was seen from the reduced cell viability and increased release of LDH. Both cell lines were capable of having Hsp70 induced following a heat shock. However, exposure of the cells to OTA before the heat shock challenge prevented Hsp70 induction. Results of the study show that OTA does not induce Hsp70 in rat kidney or in cultured kidney cells. The absence of Hsp70 protective effects in the cells and tissues might be a possible explanation for the cumulative destructive effects of OTA and a silent onset of endemic nephropathy in humans and of OTA-induced experimental nephrotoxicity in animals.     

Biochemistry of apoptotic cell death

Apoptosis is a physiological cell suicide program that is critical for the development and maintenance of healthy tissues. Regulation of programmed cell death allows the organism to control the cell number and the tissue size, and to protect itself from rogue cells that threaten homeostasis. The changed activity of numerous genes influences switching of cells to a self-destruction program. Apoptosis requires co-ordinated action and fine tuning of a set of proteins that are either regulators or executors of the process. Cancer, autoimmune diseases, immunodeficiency disease, reperfusion injury and neurodegenerative disorders are characterised by disregulation of apoptosis. Modulation of the expression and activation of the key molecular components of the apoptotic process has emerged as an attractive therapeutic strategy for many diseases.     

Effects of pre- and postnatal litter size reduction on development and behavior of rat offspring

Litter size was reduced to 2-5 rat pups either prenatally by unilateral maternal oviduct ligation (Group PRN) or postnatally by removing pups (Group PST). Normal size litters (8-10 pups) of sham ligated (SHM) and intact (CON) mothers served as controls. Weights at 30 days were increased by prenatal or postnatal reduction and reduced by prenatal stress (SHM); the sex difference in weight was most pronounced in PRN rats. At 75 days PRN rats were heaviest, with no differences between the other groups. Relative ovarian weights were reduced in PRN females and absolute testes weights increased in PST males. The PRN and SHM females had smaller relative adrenal weights than CON and PST females. Open-field activity was generally increased by prior avoidance conditioning and effects of treatments were found only in groups tested after avoidance-conditioning: PRN and SHM rats were more active than PST and CON rats, particularly on Days 1 (SHM) and 4 (SHM and PRN) of testing. Passive-avoidance behavior of PRN rats was also more susceptible to previous test experience: they emerged more slowly if they had prior open-field experience. The PST animals, in contrast, emerged more rapidly after prior test experience. Plasma corticosterone levels and shuttlebox conditioning and extinction were unaffected by treatments.     

Screening for risk factors for chronic disease in children from fifteen countries

An international collaborative health screening project was undertaken to stimulate interest in child health education, to study feasibility of health screening in young children from diverse cultures, and to compare the distribution of chronic disease risk factors among 15 countries. Data for the 13-year-old participants showed that risk factors defined by cholesterol greater than 180 mg/dl, systolic blood pressure greater than 130 mm Hg, and daily or occasional smoking were present, to varying degrees, in children from each country. We found no relationship between obesity and cholesterol or blood pressure for these children. The acceptability of the screening, the children's enjoyment in participation, and the prevalence of risk factors at this young age lead to the conclusion that school-based health education programs should be initiated during childhood.     

Association of hsp70-2 (+1267A/G), hsp70-hom (+2437T/C), HMOX-1 (number of GT repeats) and TNF-alpha (+489G/A) polymorphisms with COPD in Croatian population

ObjectiveTo test for possible association of hsp70-2 (+ 1267A/G), hsp70-hom (+ 2437T/C), HMOX-1 (number of GT repeats) and TNF-α (+ 489G/A) polymorphisms with chronic obstructive pulmonary disease (COPD) in Croatian population.MethodsGenotyping of DNA isolated from whole blood of 130 COPD patients (as defined by spirometry) and 95 healthy controls was performed. Fragment size analysis upon restriction enzyme digestion and/or sequencing was used for genotype/allele definition. Significance of findings was tested using χ² test.Resultshsp70-2 (+ 1267A/G) polymorphism was significantly associated with COPD. Results of genotyping analysis indicated that a genotype carrying G allele was preferentially associated with COPD; odds ratio (OR) = 1.50, 95% confidence interval (CI) = 1.00–2.24 and P = 0.061. OR for the GG genotype was 3.47 with CI = 1.26–9.56 and P = 0.04. No association for hsp70-hom (+ 2437T/C), TNF-α (+ 489G/A) and HMOX-1 (number of GT repeats) polymorphisms were found. In addition, comparison of genotype frequencies among different stages of disease severity (GOLD II-IV) revealed no discrimination for any of the tested polymorphisms.ConclusionThis study is supporting the association of hsp70-2 (+ 1267A/G) polymorphism and COPD. Higher frequency of G allele and GG genotype in Croatian COPD patients was observed. There was no evidence for the association of hsp70-hom (+ 2437T/C), TNF-α (+ 489G/A) SNPs and HMOX-1 (number of GT repeats) polymorphism with COPD. Allele and genotype frequencies for all of the tested polymorphisms show no association with disease severity (GOLD II-IV).     

Inflammatory epidermolysis bullosa acquisita in a 4‐year‐old girl

This study presents a case of linear immunoglobulin A dermatosis‐like epidermolysis bullosa acquisita in a 4‐year‐old girl showing rapid, widespread and inflammatory skin lesions. The diagnosis was confirmed by histopathology, direct and indirect immunofluorescence, various immunoblotting analyses and enzyme‐linked immunosorbent assays. Despite the severe clinical manifestations, the disease was successfully controlled by combination therapy of oral prednisolone and dapsone.     

Apoptosis and oxidative stress induced by ochratoxin A in rat kidney

Ochratoxin A (OTA) is a widespread mycotoxin produced by several species of fungi. OTA induces a tubular-interstitial nephropathy in humans and in animals. It has been implicated as one of the aetiological agents involved in the development of endemic nephropathy. OTA-induced oxidative stress and apoptosis may play key roles in the development of chronic tubulointerstitial nephritis connected to the long-term exposure to this food contaminant. We studied the effects of low doses of OTA on kidney cells. Wistar rats were treated with 120 g OTA/kg bodyweight daily, for 10, 30 or 60 days. Toxin concentration in kidney was proportional to the time of exposure, and amounted to 547.2, 752.5 and 930.3 ng OTA/g kidney tissue after 10, 30 and 60 days, respectively. OTA treatment caused an increased number of cells undergoing apoptosis in both proximal and distal epithelial kidney cells. The apoptotic cells were visualised using the TUNEL assay and staining with haematoxylin and eosin in situ. The number of apoptotic cells in rats treated for 10, 30 and 60 days increased by 5-, 6.4- and 12.7-fold, respectively, compared with the control cells. However, DNA electrophoresis did not show characteristic fragmentation (DNA laddering). The oxidative stress was evident via increased malondialdehyde formation. The concentration of lipid peroxides showed an increase (36%), but the activity of superoxide dismutase decreased (26%) in 60-day treated rats. In spite of the observed biochemical and morphological changes in the kidney cells, renal functional status was preserved to the end of experiment. This study demonstrates that a combination of morphologic and biochemical markers can be used to monitor early cell death in OTA-induced renal injury. We have shown that the exposure to the relatively low OTA concentrations has activated apoptotic processes and oxidative damage in kidney cells.     

渥太华宣言,第1部分——人体健康相关干预性试验方案信息与结果的国际注册原则

1 目的 渥太华宣言旨在为临床试验的注册(第1部分)及其操作(第Ⅱ部分)建立国际公认的原则.