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Biomedical subjects

V R Winrow

Publications and source records attributed to V R Winrow.

At least 19 recordsLinked to original sources

The transcription factors hypoxia-inducible factor 1alpha and Ets-1 colocalize in the hypoxic synovium of inflamed joints in adjuvant-induced arthritis.

OBJECTIVE: To determine the relationship between hypoxia and the expression of Ets-1 and hypoxia-inducible factor 1alpha (HIF-1alpha) in both normal and inflamed joints. Adjuvant-induced arthritis (AIA) was used as the model system, since it mirrors many aspects of the pathology of rheumatoid arthritis. METHODS: Adjuvant arthritis was induced in a group of 10 female Lewis rats. A second group of 10 uninjected female Lewis rats served as naive controls. When a maximum clinical joint score was achieved in the AIA group, all 20 rats were injected with the specific hypoxic cell marker Hypoxyprobe-1 and subsequently killed. Hypoxyprobe-1 adducts, Ets-1, and HIF-1alpha were localized in the joints of the hind feet from these groups using immunohistochemistry. RESULTS: Compared with the joints from control rats, inflamed joints contained markedly more cells with Hypoxyprobe-1 adduct immunoreactivity, Ets-1-immunoreactive nuclei, and nuclear immunoreactivity for both Ets-1 and HIF-1alpha. CONCLUSION: Our results demonstrate the presence of hypoxia in inflamed joints in this experimental model of arthritis. The colocalization of Ets-1 and HIF-1alpha in these hypoxic areas suggests that hypoxia may induce Ets-1 and HIF-1alpha expression during joint inflammation.

Animals↗

Expression of heat shock protein 32 (hemoxygenase-1) in the normal and inflamed human stomach and colon: an immunohistochemical study.

Heat shock protein 32 (Hsp32, hemoxygenase-1) is induced by reactive oxygen metabolites (ROM) and degrades heme leading to the formation of antioxidant bilirubin. Increased mucosal generation of ROM occurs in gastritis and inflammatory bowel disease. We aimed to assess mucosal expression of Hsp32 in normal stomach and colon and to test the hypothesis that disease-related differential expression occurs in inflamed tissue. Gastric body and antral mucosal biopsies were obtained from 33 patients comprising Helicobacter pylori-negative normal controls (n = 8), H pylori-negative gastritis patients (n = 11), and H pylori-positive gastritis patients (n = 14). Forty-seven archival colonic mucosal biopsies selected comprised normal histology (n = 10), active ulcerative colitis (UC) (n = 9), inactive UC (n = 8), active Crohn's disease (CD) (n = 8), inactive CD (n = 6), and other colitides (n = 6). Hsp32 expression in formalin-fixed sections was assessed by avidin-biotin peroxidase immunohistochemistry using a polyclonal rabbit anti-Hsp32 as the primary antibody. Immunohistochemical staining identified Hsp32 in all groups. Diffuse cytoplasmic staining was seen in gastric and colonic epithelial and lamina proprial inflammatory cells. Staining scores for Hsp32 were higher in antral H pylori-positive (P = 0.002) and H pylori-negative (P = 0.02) gastritis than in controls and in body H pylori-positive gastritis than in the other 2 groups (P < 0.01). Expression of Hsp32 was increased in active UC compared with inactive disease (P = 0.03) and normal controls (P = 0.02). In conclusion, Hsp32 is expressed constitutively in normal gastric and colonic mucosa, and differential expression occurs in these tissues when they are inflamed. Upregulation of Hsp32 may be an adaptive response to protect mucosa from oxidative injury in patients with gastritis and inflammatory bowel disease.

Colitis, Ulcerative↗

Pulsed electromagnetic fields simultaneously induce osteogenesis and upregulate transcription of bone morphogenetic proteins 2 and 4 in rat osteoblasts in vitro.

Pulsed electromagnetic fields (PEMF) are successfully employed in the treatment of a variety of orthopaedic conditions, particularly delayed and nonunion fractures. In this study, we examined PEMF effects on in vitro osteogenesis by bone nodule formation and on mRNA expression of bone morphogenetic proteins 2 and 4 by reverse-transcriptase polymerase chain reaction (RT-PCR) in cultured rat calvarial osteoblasts. PEMF exposure induced a significant increase in both the number (39% over unexposed controls) and size (70% larger compared to unexposed controls) of bone-like nodules formed. PEMF also induced an increase in the levels of BMP-2 and BMP-4 mRNA in comparison to controls. This effect was directly related to the duration of PEMF exposure. This study shows that clinically applied PEMF have a reproducible osteogenic effect in vitro and simultaneously induce BMP-2 and -4 mRNA transcription. This supports the concept that the two effects are related.

Animals↗

Circulating antibodies to the 60-kD heat shock protein (hsp) family in patients with Helicobacter pylori infection.

Whilst the mechanism by which Helicobacter pylori causes different gastroduodenal diseases is uncertain, strains producing the cytotoxin-associated protein (CagA) have greater pathogenicity. Hsps are immunogenic molecules induced by inflammatory mediators. The aim of this study was to assess pathogenicity of hsp antibodies in H. pylori-infected patients. ELISA techniques were used to assay sera of H. pylori-positive patients with gastritis, gastric atrophy, duodenal or gastric ulcer, and H. pylori-negative controls, for antibodies to CagA and to human, mycobacterial, and in 20 sera, H. pylori (hspB) 60-kD hsp. IgA antibodies to mycobacterial hsp60 in atrophy patients were elevated compared with patients with gastritis (P < 0.05) and with H. pylori-negative controls (P < 0.0005). IgA antibodies to human hsp60 in gastric atrophy patients were elevated compared with H. pylori-negative controls (P < 0.05). Patients with atrophy (P < 0.0005) and gastritis (P < 0.05) who were CagA-positive had raised titres of anti-mycobacterial hsp60 IgA antibodies compared with controls. IgA antibody levels to hspB were positively correlated with those to mycobacterial hsp60 (mhsp60) (P < 0.05) and human hsp60 (hhsp60) (P < 0.005). IgA antibodies to hsp60 are associated with gastroduodenal disease, particularly gastric atrophy, in H. pylori-infected patients. Increased humoral responses to hsp60 could either contribute to gastric atrophy or result from greater gastric mucosal damage induced by CagA-positive strains of H. pylori.

Autoantibodies↗

Protection of rats from adjuvant arthritis by immunization with naked DNA encoding for mycobacterial heat shock protein 65.

OBJECTIVE: To assess the feasibility of vaccination with naked DNA encoding for mycobacterial heat shock protein 65 (hsp65) in the modulation of experimental arthritis. METHODS: Adjuvant arthritis (AA) was induced in Lewis rats preimmunized, intramuscularly, with a plasmid encoding for hsp65 (pCMV3.65). Clinical scores were recorded for 3-4 weeks, and histologic and radiologic parameters were evaluated. Cellular and antibody reactivity to hsp65 was assessed. The expression of the hsp65 gene was investigated in injected muscles. RESULTS: The pCMV3.65-treated rats were significantly protected from disease development in comparison with the control groups. This finding correlated with the results of histologic and radiologic examinations of the involved joints. The message for hsp65 was detected in injected muscles. T cell proliferation and antibodies to this protein were found to be elevated in pCMV3.65-treated rats when compared with both the arthritic control (AA-induced) and the naive (did not receive adjuvant) animals. CONCLUSION: We have demonstrated for the first time that naked DNA delivery is feasible in controlling experimental autoimmune disease. Although the actual mechanism of protection has not been fully elucidated, this simple and versatile approach could represent a useful tool in dissecting basic autoimmune mechanisms.

Animals↗

Protein profiling in cardiac tissue in response to the chronic effects of alcohol.

An investigation was made into cardiac protein levels after chronic ethanol consumption to examine whether specific proteins are affected by alcohol. Ethanol was administered for six weeks to male Wistar rats which were fed a nutritionally complete liquid diet containing 35% of total calories as ethanol. Controls were pair-fed identical amounts of the same diet in which ethanol was replaced by isocaloric glucose; thus both groups had identical nutritional intakes, albeit differences in ethanol or carbohydrate. After six weeks' feeding, cardiac tissue was removed and analyzed by two-dimensional electrophoresis, where equal amounts of proteins were studied. Protein patterns were analyzed by computerized densitometry and characterized by comparison with a database of known cardiac proteins. Chronic alcohol feeding caused significant decreases in the relative amounts of various proteins, including several tentatively identified as heat shock protein (HSP) 60, HSP70, and desmin. The relative proportions of actin, vimentin, myosin light chain 1, myosin light chain 2, and albumin, remained unchanged. Examination of antibodies raised against HSP65 showed no overt differences in plasma levels following chronic alcohol consumption, and liver changes as assessed by histology were mild. In conclusion, chronic alcohol appears to have selective effects on particular proteins, and the effects were not directly ascribed to overt liver dysfunction or malnutrition. This may explain some of the functional and morphological characteristics observed in alcohol-induced heart muscle disease, including reduced contractility.

Alcoholism↗

A synthetic 10-kD heat shock protein (hsp10) from Mycobacterium tuberculosis modulates adjuvant arthritis.

The heat shock protein, hsp10, is an abundant protein in Mycobacterium tuberculosis (Mtb), its nucleotide sequence encoding a protein of 99 amino acids with a molecular mass of 10.7 kD. This sequence is phylogenetically conserved, being represented by the GroES homologue of Escherichia coli. Hsp10 and GroES are members of the chaperonin 10 family of molecular chaperones, and GroEs is necessary for the optimal activity of GroEL, a member of the chaperonin 60 family and the E. coli homologue of mycobacterial hsp65. Since hsp65 has been implicated in both experimental and human rheumatoid arthritis, we aimed to assess the immunomodulatory effects of its co-chaperonin, hsp10, in experimental arthritis. Our results show that an aqueous solution of a mycobacterial hsp10 delayed the onset and severity of adjuvant-induced arthritis in rodents when administered after disease induction but before joint involvement occurred. This biological activity was specific for the hsp10 of Mtb, since neither GroES not the rat homologue was effective. Using synthetic hsp10 fragments, the activity was localized to the N-terminal region of the molecule. Assessment of circulating antibody levels to mycobacterial hsp10 and hsp65 indicated that all arthritic rats had increased titres to both hsp10 and hsp65: hsp10-treated rats showed further elevation of this humoral response not only to hsp10 but also to hsp65 when compared with the untreated arthritic control. This is the first report of the immunomodulatory activity of mycobacterial hsp10 in experimental arthritis, and exhibits a potential role for this co-chaperonin in pathophysiological situations.

Adjuvants, Immunologic↗

PPD and hsp65 induced monoarthritis initiates spontaneous recurrent flares in Lewis rats.

OBJECTIVES: To investigate the time course of a monoarthritis induced with the purified protein derivative of tuberculin (PPD) or a recombinant 65 kDa heat shock protein (rhsp65) in two different strains of sensitised rats. METHODS: Wistar and Lewis rats, sensitised with heat killed Mycobacterium tuberculosis in oil, were challenged intraarticularly with PPD or rhsp65 and monitored for six weeks. Inflammation was assessed by joint swelling, histology, and radiographic studies. RESULTS: Sensitised Lewis rats injected with PPD or rhsp65 showed a chronic response with recurrent spontaneous flares, while Wistar rats showed one inflammatory episode. CONCLUSIONS: The Wistar strain response to PPD resembles a transient reactive arthritis, while the response of the Lewis strain mimics the relapsing nature of rheumatoid synovitis, providing an interesting model to determine dominant immunopathogenic mechanisms.

Acute Disease↗

Circulating IgA antibody against a 65 kDa heat shock protein in acute alcoholic hepatitis.

Heat shock proteins are known to be immunogenic in a number of diverse conditions and can be induced by hypoxia, tumour necrosis factor and alcohol--all potential triggers in patients with acute alcoholic hepatitis. In the present study, sera from 23 patients with acute alcoholic hepatitis, 18 liver disease controls, ten patients with inactive alcoholic liver disease and six alcoholics without liver damage were screened for the antibody to a 65 kDa heat shock protein using an ELISA technique. IgA antibody was found to be closely associated with alcoholic hepatitis; 20/23 patients were seropositive compared to 5/18 liver disease controls and 4/10 with inactive alcoholic cirrhosis. IgM and IgG antibodies to the 65 kDa heat shock protein were less closely associated with alcoholic hepatitis and were positive in nine and eight of the 23 patients, respectively, compared with six and seven of 18 liver disease controls. Neither antibody was detected in alcoholics without liver damage or normal controls. These data indicate that an IgA immune mediated response to the 65 kDa heat shock protein is characteristic of patients with acute alcoholic hepatitis and may be one mechanism underlying observed persistence of liver damage after cessation of alcohol consumption.

Acute Disease↗

Arthritogenic potential of the 65 kDa stress protein--an experimental model.

OBJECTIVES: To assess the effect of an intra-articular presentation of stress (heat shock) proteins (hsp) on joint inflammation. METHODS: Wistar rats were sensitised with a suspension of heat killed Mycobacterium tuberculosis in oil in the scruff of the neck and challenged intra-articularly with stress protein or M tuberculosis preparations. Inflammation was assessed by joint swelling and, using immunohistology, cellular infiltration of the synovium and antibody induction by an enzyme-linked immunosorbent method. RESULTS: It was shown, for the first time, that the intra-articular administration of a recombinant myobacterial 65 kDa hsp can induce joint inflammation in M tuberculosis sensitised recipients; both powdered M tuberculosis and the purified protein derivative of tuberculin (PPD) produced a similar response, with T cell infiltration of the synovium and a time course typical of delayed type hypersensitivity. This response was specific to the 65 kDa protein as another immunodominant mycobacterial stress protein of 10 kDa was ineffective. Furthermore, intra-articular injection of the 65 kDa hsp induced an antibody response against both the 65 kDa and 10 kDa proteins and the antibody titres continued to rise when knee swelling had subsided. CONCLUSIONS: These results support the hypothesis that 60 kDa proteins are a relevant arthritogenic stimulus in an M tuberculosis background. Moreover, when antigen presentation occurs in the synovium of previously sensitised individuals, circulating antibodies are generated which persist and recognise cross-reactive epitopes on several stress proteins.

Animals↗

Stress proteins in colorectal mucosa. Enhanced expression in ulcerative colitis.

Stress (heat shock) proteins are ubiquitous intracellular proteins that can be induced in vitro by physiological stress events that occur during inflammation. We have used an indirect immunoperoxidase method to locate 60-kDa stress proteins in biopsies taken from normal and inflamed colorectal mucosa. An anti-60-kDa monoclonal antibody (ML30) produced specific staining of surface epithelial cells localized to the site of the Golgi apparatus. In ulcerative colitis, there was an increased concentration of this stress protein compared with controls (P < or = 0.002) and also with a small group of active Crohn's colitis (P < or = 0.01), but no relationship between its concentration and disease activity. All biopsies also showed staining of goblet cells by ML30, suggesting a possible cross-reaction with mucin; electroblotting of crude but not purified mucin showed a faint 60-kDa band with ML30. We conclude that the 60-kDa stress protein is present in normal colorectal epithelial cells and is markedly induced in vivo in ulcerative colitis. Further, we suggest that since the 60-kDa protein functions as a molecular chaperone, it may associate with colonic mucin aiding in its synthesis and/or secretion.

Adult↗

Free radicals in inflammation: second messengers and mediators of tissue destruction.

In recent years it has become increasingly apparent that, in man, free radicals play a role in a variety of normal regulatory systems, the deregulation of which may play an important role in inflammation. As examples, we discuss the second messenger roles of: NO in the regulation of vascular tone, O2.- in fibroblast proliferation and H2O2 in the activation of transcription factors such as NF kappa B. Other control mechanisms, the physiological function of which may be perturbed in inflammation, include: the oxidative modification of low density lipoprotein, the oxidative inactivation of alpha-1-protease inhibitor, DNA damage/repair and heat shock protein synthesis. At sites of inflammation, increased free radical activity is associated with the activation of the neutrophil NADPH oxidase and/or the uncoupling of a variety of redox systems, including endothelial cell xanthine dehydrogenase. Although free radicals, thus produced, have the capacity to mediate tissue destruction, either alone or in concert with proteases, we argue that disturbances in the second messenger and regulatory activities of free radicals may also contribute significantly to the inflammatory process.

Antioxidants↗

Hepatic 60-kD heat-shock protein responses in alcoholic hepatitis.

The precise mechanism of the pathogenesis of alcoholic hepatitis is unknown, but immune involvement may perpetuate and exacerbate the process. Heat-shock proteins, normally protective, may be immunogenic and have been shown to induce antibody formation in some inflammatory conditions. Alcohol, cellular hypoxia and tumor necrosis factor, all involved in alcoholic hepatitis, are potent inducers of heat-shock protein. In this study, we sought 60-kD heat-shock protein in liver tissue with a murine monoclonal antibody and measured circulating antibody to 60-kD heat-shock protein on ELISA. Fourteen of 20 livers from patients with acute alcoholic hepatitis expressed 60-kD heat-shock protein in hepatocyte cytoplasm in a diffuse pattern with superimposed clusters; other cell types were occasionally positive. Twelve of these patients had high-titer IgA 60-kD heat-shock protein antibody in serum. In contrast, 60-kD heat-shock protein was identified in only 2 of the 10 patients with alcoholic cirrhosis without hepatitis (p = 0.013). These two patients had severe liver disease, and one patient in this group was seropositive for IgA 60-kD heat-shock protein antibody. Eight alcoholic patients with fatty liver alone were negative for antigen, and all but one were negative for antibody. The 10 patients without liver damage were negative for antigen and antibody. The findings that 60-kD heat-shock protein is present in liver tissue of patients with acute alcoholic liver damage and that circulating IgA 60-kD heat-shock protein antibody levels are increased may point to one pathogenetic mechanism underlying development and progression of liver damage in alcoholic hepatitis.

Adult↗

Circulating antibodies to heat-shock protein 60 in Crohn's disease and ulcerative colitis.

Heat-shock proteins (HSPs) are highly conserved immunogenic intracellular molecules that are induced by inflammatory mediators and may induce autoimmune phenomena in vivo. We have recently demonstrated the increased expression of HSP-60 in the colonocytes of patients with ulcerative colitis. To study further the role of HSP-60 in inflammatory bowel disease, we have now measured antibodies to recombinant mycobacterial HSP-65 (a member of the HSP-60 family) in patients with Crohn's disease, ulcerative colitis, healthy volunteers and, as disease controls, patients with confirmed bacterial diarrhoea. In comparison with healthy controls (n = 20; median level of 89 ELISA units; range 24-292), serum IgA HSP-60 antibodies were elevated in Crohn's disease (n = 21; 157; 57-364; P < 0.05) and active ulcerative colitis (n = 16; 188; 58-373; P < 0.01) but not bacterial diarrhoea (n = 10; 106; 51-285). Increased IgA HSP-60 antibody levels in patients with inflammatory bowel disease may occur as the result of HSP release from injured gut epithelium; alternatively, increased intestinal permeability could facilitate mucosal access of luminal antigens and the generation of cross-reactive anti-bacterial HSP antibodies.

Antibodies↗

Oxidants, joint inflammation and anti-inflammatory strategies.

In summary, we support the hypothesis that the rheumatoid knee is subjected to repeated hypoxic reperfusion injury. Moreover, we speculate that oxidative damage induced as a consequence of hypoxic reperfusion injury leads to the synthesis of intracellular stress proteins. In certain individuals this triggers an autoimmune response which might explain the persistance of the rheumatoid disease process. This gives scope for novel therapeutic approaches in the future development of anti-inflammatory agents.

Animals↗