Immunocytochemical expression of the 70 kD heat shock protein in ischaemic bowel disease

Ischaemic postconditioning reduces apoptosis in experimental jejunal ischaemia in horses

BACKGROUND

Ischaemic postconditioning (IPoC) refers to brief periods of reocclusion of blood supply following an ischaemic event. This has been shown to ameliorate ischaemia reperfusion injury in different tissues, and it may represent a feasible therapeutic strategy for ischaemia reperfusion injury following strangulating small intestinal lesions in horses. The objective of this study was to assess the degree cell death, inflammation, oxidative stress, and heat shock response in an equine experimental jejunal ischaemia model with and without IPoC.

METHODS

In this randomized, controlled, experimental in vivo study, 14 horses were evenly assigned to a control group and a group subjected to IPoC. Under general anaesthesia, segmental ischaemia with arterial and venous occlusion was induced in 1.5 m jejunum. Following ischaemia, the mesenteric vessels were repeatedly re-occluded in group IPoC only. Full thickness intestinal samples and blood samples were taken at the end of the pre-ischaemia period, after ischaemia, and after 120 min of reperfusion. Immunohistochemical staining or enzymatic assays were performed to determine the selected variables.

RESULTS

The mucosal cleaved-caspase-3 and TUNEL cell counts were significantly increased after reperfusion in the control group only. The cleaved-caspase-3 cell count was significantly lower in group IPoC after reperfusion compared to the control group. After reperfusion, the tissue myeloperoxidase activity and the calprotectin positive cell counts in the mucosa were increased in both groups, and only group IPoC showed a significant increase in the serosa. Tissue malondialdehyde and superoxide dismutase as well as blood lactate levels showed significant progression during ischaemia or reperfusion. The nuclear immunoreactivity of Heat shock protein-70 increased significantly during reperfusion. None of these variables differed between the groups. The neuronal cell counts in the myenteric plexus ganglia were not affected by the ischaemia model.

CONCLUSIONS

A reduced apoptotic cell count was found in the group subjected to IPoC. None of the other tested variables were significantly affected by IPoC. Therefore, the clinical relevance and possible protective mechanism of IPoC in equine intestinal ischaemia remains unclear. Further research on the mechanism of action and its effect in clinical cases of strangulating colic is needed.

Hsp10, Hsp70, and Hsp90 immunohistochemical levels change in ulcerative colitis after therapy

Ulcerative colitis (UC) is a form of inflammatory bowel disease (IBD) characterized by damage of large bowel mucosa and frequent extra-intestinal autoimmune comorbidities. The role played in IBD pathogenesis by molecular chaperones known to interact with components of the immune system involved in inflammation is unclear. We previously demonstrated that mucosal Hsp60 decreases in UC patients treated with conventional therapies (mesalazine, probiotics), suggesting that this chaperonin could be a reliable biomarker useful for monitoring response to treatment, and that it might play a role in pathogenesis. In the present work we investigated three other heat shock protein/molecular chaperones: Hsp10, Hsp70, and Hsp90. We found that the levels of these proteins are increased in UC patients at the time of diagnosis and decrease after therapy, supporting the notion that these proteins deserve attention in the study of the mechanisms that promote the development and maintenance of IBD, and as biomarkers of this disease (e.g., to monitor response to treatment at the histological level).

Morphological data indicate a stress response at the oral border of strangulated small intestine in horses

Strangulation colic often leads to surgery. We aimed to document the molecular response in the non-resected intestine in these horses using quantitative Western blot analysis, and immunohistochemistry. The expression of hypoxia-inducible factor 1-alpha (HIF1α) was investigated together with two molecular pathways initiated after protein destruction: proteasome degradation via ubiquitin chain formation and protein restoration via molecular chaperones such as inducible heat shock protein 70 (HSP70). In addition, the expression of c-fos and c-jun could indicate an early proinflammatory response. Ubiquitin, HSP70, c-jun and c-fos protein levels did not differ between the control and colic samples nor were they related to the clinical outcome in case of strangulation colic. However, the immunohistochemical distribution of several of these proteins (ubiquitin, HSP70 and c-jun) differed significantly between colic and control samples. The elevated presence of ubiquitin in the enterocytes' nucleus, of HSP70 in the smooth muscle cells' nucleus and of c-jun in enteric neurons suggest protective and degenerative pathways are activated in the apparently healthy non-resected tissue in case of strangulation obstruction, perhaps providing a molecular and morphological basis for the development of complications like post-operative ileus.

Perinatal expression of HSP70 and VEGF in neonatal rat lung vessels exposed to nicotine during gestation

We assessed the influence of maternal nicotine exposure during gestation on perinatal expression of HSP70 and VEGF in rat lung parenchyma and lung vessels. Adult white Sprague-Dawley virgin rats were mated with adult male rats over 2 days, with two females for every male. After confirming pregnancy, 30 gravid rats (dams) were then randomly assigned to two equal groups (one experimental and one control; n=15 in each). Experimental dams were treated with subcutaneus (s.c.) (-)-nicotine tartrate, 3 mg/kg body weight/day, during pregnancy from gestational days 9 through 21. After sacrifice, lungs were removed en bloc and formalin-fixed, and paraffinembedded tissue sections were evaluated by immunohistochemistry using a three-step streptavidin-biotin-peroxidase method with monoclonal antibodies directed against HSP70 or VEGF. HSP70 and VEGF expression was increased in the vascular smooth muscle cells of the experimental group (t1) compared to the control group (t(2))t(1)=7.593, t(2)=4.666, p<0.05). The number of bronchioles that stained positively with HSP70 was higher in the nicotineexposed group than in the control group (t(1)=9.274, t(2)=6.956, p<0.05). In conclusion, gestational nicotine exposure increased the expression of VEGF and HSP70 in rat lung parenchyma, especially in the airway epithelium and vascular smooth muscle cells. In vascular smooth muscle cells, these molecules may contribute to nicotine-related hypoxic pulmonary hypertension.

Hipoacusia asociada a colitis ulcerosa

OBJECTIVE

To value the eventual immunomediation in sensorineural hearing loss (SHL) on patients bearing of ulcerative colitis (UC).

MATERIAL AND METHODS

In a group of forty-nine cases with a mean age of 41.6+/-9.3 years old we studied the hearing loss level, the disease activity index, the peripheral blood inflammation markers and the anticochlear antibodies by mean of Western-blot technique (WB).

RESULTS

The 26.5% knew about their deafness, although SHL was detected in 59.1% of cases. The mean age of onset was 40.3+/-9.8 years. 48.9% showed a positive WB, always in 68-70 kDa molecular weight blots. Moreover, patients with positive WB showed more severe deafness, higher disease activity and more altered parameters, especially erythrosedimentation rate.

CONCLUSIONS

Audiologic and peripheral blood findings observed allow us to establish a reasonable suspicion of an autoimmune or immunomediated pathway of hearing loss on UC.

Amelioration of dextran sulfate colitis by butyrate: role of heat shock protein 70 and NF-kappaB

Butyrate enemas have been demonstrated to ameliorate inflammation in ulcerative colitis. The mechanism of this protective effect of butyrate is not known, and this study examines the effect of butyrate on epithelial function, inducible heat shock protein 70 (HSP70) expression, and NF-kappaB activation in experimental colitis. Colitis was induced in rats by oral dextran sulfate sodium (DSS) and by butyrate or saline enemas. Mucosal barrier function was assessed by electrical resistance and [14C]mannitol permeability. HSP70 production was determined by [35S]methionine labeling, Western blot analysis, and immunohistochemistry. Activation of heat shock factors (HSFs) and NF-kappaB was evaluated by EMSA. Butyrate showed a significant protection against the decrease in cell viability, increase in mucosal permeability, and polymorphonuclear neutrophil infiltration seen in DSS colitis. Butyrate inhibited HSP70 expression in DSS colitis and also inhibited the activation of HSF and NF-kappaB. Thus butyrate enema was found to be cytoprotective in DSS colitis, an effect partly mediated by suppressing activation of HSP70 and NF-kappaB.

Analysis of mucosal regeneration and the expression profile of heat shock protein 70 in the isolated small bowel segment

To investigate the mechanisms underlying the regeneration of the denervated small bowel segment from ischemic injury, we examined the heat shock protein 70 (HSP70) expression profile and compared it to the histopathological and proliferative changes seen in an isolated bowel segment using a rabbit model. Two weeks following the small bowel segment transplantation to the subcutaneous space, the vascular pedicle was sectioned. Next, the rabbits were divided into three groups based on the collection time of the isolated bowel segment (3, 7, and 14 days for Groups A, B, and C, respectively). The unsectioned small bowel segment was utilized as a control for each group. Histological studies showed that no experimental group recovered from mucosal injury. The bromodeoxyuridine labeling index showed that the more severe mucosal injury group had the highest bromodeoxyuridine incorporation. In the experimental groups, HSP70 immunoreactivity was intensely seen in the regenerating epithelial cells and inflammatory cells. In the control mucosa, HSP70 immunoreactivity was weakly seen in the subepithelial stromal tissue, crypt cells and not in epithelial cells. The present study shows that the isolated bowel segment requires longer periods for regeneration from ischemic injury and HSP70 may play an important role during the regeneration process.

General features of gastric carcinomas and comparison of HSP70 and NK cell immunoreactivity with prognostic factors

During the period of 1996-1998 ninety-four gastrectomy specimens with gastric carcinoma referred to Erciyes University, Medical Faculty, Department of Pathology, were examined histopathologically, histochemically and immunohistochemically. General characteristics of gastric carcinomas and prognostic factors were studied. According the Lauren classification, of the 94 cases of gastric carcinomas, 56 were intestinal type, 21 were diffuse type and 17 were mixed type carcinoma. The association rates of Helicobacter pylori, chronic atrophic gastritis and intestinal metaplasia with gastric carcinomas were high. There was strong immunorectivity with HSP70 in 62,5% of the intestinal type carcinomas. This ratios were lower in diffuse and mixed type carcinomas (p<0.05). The more tumor size and invasion depth increased, the more HSP70 immunoreactivity was obtained (p<0.05). HSP70 immunorectivity was considerably higher in the patients having lymph node metastasis and vascular invasion (p<0.05). It was found that the NK cell number was low in the tumor but higher around the tumor in early gastric carcinomas, compared with advanced carcinomas (p>0.05). In the tumors larger than 10 cm with vascular invasion, NK cell number was lower around the tumor (p>0.05). Defining prognostic factors of gastric carcinomas is of importance to clinicians. It is thought that HSP70 immunoreactivity, besides invasion depth, lymph node metastasis, vascular invasion, tumor size and inflammatory reaction against the tumor, is important in prognosis and associated with advanced stage.