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Biomedical subjects

R W G Watson

Publications and source records attributed to R W G Watson.

At least 19 recordsLinked to original sources
PubMed2006

Expression and regulation of connective tissue growth factor by transforming growth factor beta and tumour necrosis factor alpha in fibroblasts isolated from strictures in patients with Crohn's disease.

BACKGROUND: Connective tissue growth factor (CTGF) stimulates fibroblast proliferation and extracellular matrix production. Fibroblasts may initiate stricture formation in Crohn's disease through overexpression of CTGF. Stricturing that occurs in patients with Crohn's disease after treatment with anti-tumour necrosis factor (TNF) alpha may be due to dysregulation of CTGF homeostasis. The aim of this study was to examine CTGF expression and regulation in fibroblasts isolated from patients with Crohn's disease. METHODS: Fibroblasts were isolated by a primary explant technique from serosal biopsies of strictured segments of bowel in eight patients undergoing resection for Crohn's disease and from normal colon in seven patients having resection for benign or malignant colorectal disease. Cells were stimulated with transforming growth factor (TGF) beta and TNF-alpha. CTGF protein and mRNA expression were measured by western blotting and real-time polymerase chain reaction respectively. RESULTS: Mean(s.d.) CTGF protein expression in strictured Crohn's fibroblasts was higher than that in normal fibroblasts (56.5(9.7) versus 17.0(10.0) respectively; P = 0.011). In normal and strictured Crohn's fibroblasts, culture with TGF-beta increased CTGF protein and mRNA expression. Co-culture of normal fibroblasts with TNF-alpha suppressed TGF-beta-stimulated CTGF expression. CONCLUSION: : Increased expression of CTGF in strictured Crohn's fibroblasts underlies its role in fibrosis. TNF-alpha suppresses fibrosis by downregulating fibroblast CTGF expression, an effect that may be lost following anti-TNF-alpha treatment, thereby promoting stricture formation.

Adult↗
PubMed2006

Novel titanocene anti-cancer drugs and their effect on apoptosis and the apoptotic pathway in prostate cancer cells.

Advanced prostate cancer is not curable by current treatment strategies indicating a significant need for new chemotherapeutic options. Highly substituted ansa-titanocene compounds have shown promising cytotoxic activity in a range of cancers. The objectives of this study are to examine the effects of these titanocene compounds on prostate cancer cells. Prostate cell lines were treated with three novel titanocene compounds and compared to titanocene dichloride and cisplatin. Percent apoptosis, viability and cell cycle were assessed using propidium iodide DNA incorporation with flow cytometry. Cytochrome C was assessed by western blotting of mitochondrial and cytoplasmic fractions. Apoptosis Inducing Factor was assessed by confocal microscopy. These novel compounds induced more apoptosis compared to cisplatin in a dose dependent manner. Compound Y had the most significant effect on cell cycle and apoptosis. Despite the release of cytochrome C from the mitochondrial fraction there was no inhibition of apoptosis with the pan caspase inhibitor, ZVAD-FMK. AIF was shown to translocate from the cytosol to the nucleus mediating a caspase independent cell death. Bcl-2 over expressing PC-3 cells, which were resistant to cisplatin induced apoptosis, underwent apoptosis following treatment with all the titanocene compounds. This study demonstrates possible mechanisms by which these novel titanocene compounds can mediate their apoptotic effect in vitro. The fact that they can induce more apoptosis than cisplatin in advanced cancer cell lines would confer an advantage over cisplatin. They represent exciting new agents with future potential for the treatment of advanced prostate cancer.

Amino Acid Chloromethyl Ketones↗
PubMed2006

Transforming growth factor-beta (TGF-beta) in acute injuries of the spinal cord.

Injuries to the spinal cord may be associated with increased healing of fractures. This can be of benefit, but excessive bone growth can also cause considerable adverse effects. We evaluated two groups of patients with fractures of the spinal column, those with neurological compromise (n=10) and those without (n=15), and also a control group with an isolated fracture of a long bone (n=12). The level of transforming growth factor-beta (TGF-beta), was measured at five time points after injury (days 1, 5, 10, 42 and 84). The peak level of 142.79 ng/ml was found at day 84 in the neurology group (p<0.001 vs other time points). The other groups peaked at day 42 and had a decrease at day 84 after injury (p<or=0.001). Our findings suggest that TGF-beta may have a role in the increased bone turnover and attendant complications seen in patients with acute injuries to the spinal cord.

Acute Disease↗
PubMed2005

Inhibition of the stress response to breast cancer surgery by regional anesthesia and analgesia does not affect vascular endothelial growth factor and prostaglandin E2.

Angiogenesis is essential for breast cancer metastases formation and is mediated by vascular endothelial growth factor (VEGF) and prostaglandin E2 (PGE2). We hypothesized that serum levels of VEGF and PGE2 are increased by the stress response to breast cancer surgery and attenuated by paravertebral anesthesia and analgesia (PVAA). Thirty women undergoing mastectomy were enrolled in this prospective, randomized study, to receive general anesthesia (GA) and postoperative opioid analgesia (morphine 0.1 mg/kg bolus and patient-controlled infusion) or GA and PVAA (72-h infusion). All patients received rectal diclofenac. Venous blood samples were taken preoperatively and at 4 and 24 h postoperatively for serum glucose, cortisol, C-reactive protein, VEGF, and PGE2. PVAA inhibited the surgical stress response, as indicated by significantly less plasma glucose, cortisol, and C-reactive protein. VEGF and PGE2 values did not differ significantly between the groups. Mean (SD) percentage change in VEGF at 4 and 24 h respectively were 3% +/- 44% versus 9% +/- 80%, P=0.29 and 5% +/- 43% versus -10% +/- 63%, P=0.41 for patients with combined general and PVAA and GA alone, respectively. Mean percentage change in postoperative PGE2 at 4 and 24 h respectively was 10% +/- 17% versus 11% +/- 69%, P=0.29 and 34% +/- 19% versus 47% +/- 18%, P=0.15. We conclude that despite inhibiting the surgical stress response, PVAA had no effect on serum levels of putative breast cancer angiogenic factors, VEGF and PGE2.

Adult↗
PubMed2004

Increased vascular endothelial growth factor production in fibroblasts isolated from strictures in patients with Crohn's disease.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that is implicated in early wound healing and fibrosis. Fibroblasts may initiate stricture formation in Crohn's disease through overexpression of VEGF. The aim of this study was to examine VEGF expression and regulation in fibroblasts isolated from patients with Crohn's disease. METHODS: Fibroblasts were isolated by a primary explant technique from serosal biopsies of non-strictured and strictured segments of bowel from eight patients undergoing resection for Crohn's disease, and normal colon from six patients undergoing resection for benign and malignant colorectal disease. Fibroblasts were cultured with transforming growth factor (TGF) beta and corticosteroids. After 24 h the culture supernatant was collected for VEGF assay by enzyme-linked immunosorbent assay. RESULTS: VEGF production was significantly higher in fibroblasts isolated from strictures (mean(s.e.m.) 1980(260) pg/ml) than from non-strictured segments (1116(165) pg/ml) in patients with Crohn's disease or control fibroblasts (898(93) pg/ml). TGF-beta increased VEGF production in normal and non-strictured Crohn's fibroblasts. Corticosteroids suppressed unstimulated VEGF production in all groups. CONCLUSION: Enhanced serosal fibroblast VEGF production might play a role in initiating stricture formation in Crohn's disease. VEGF production in serosal fibroblasts is sensitive to stimulation with TGF-beta. Corticosteroids may reduce stricturing through suppression of VEGF.

Adult↗
PubMed2004

Hypoxia inhibits human bladder smooth muscle cell proliferation: a potential mechanism of bladder dysfunction.

AIMS: Recent animal studies have suggested that bladder outflow obstruction causes bladder wall hypoxia during both the filling and the voiding phases of the micturition cycle. We have previously demonstrated that mechanical deformation of human detrusor leads to smooth muscle (SM) cell hypertrophy and hyperplasia, which may then contribute to hypoxia in the dysfunctional bladder. We hypothesise that the detrusor's response to a hypoxic environment contributes to bladder dysfunction. The aim of this study was to evaluate the effect of hypoxia on detrusor cell survival and growth. METHODS: Normal human detrusor muscle was obtained at radical cystectomy and primary cultures were established. Cells were then cultured in the presence of 1% oxygen in a hypoxic chamber for different times. Apoptosis was assessed by propidium iodide DNA staining and flow cytometry. Proliferation was assessed by radiolabelled thymidine incorporation. Cell supernatants were retained for growth factor estimation by enzyme linked immuno-sorbent assay (ELISA), and total cell and nuclear extracts were isolated for Western blotting. RESULTS: SM cells responded to the presence of hypoxia through significant upregulation of survival factors hypoxia inducible factor (HIF 1alpha) and vascular endothelial growth factor (VEGF) in a time-dependent manner. Hypoxia did not induce cell death, but significantly reduced the rate of proliferation over time, associated with an increase in the cell cycle inhibitor p27kip1. CONCLUSIONS: In an in vitro human detrusor cell culture model, cells demonstrate a resistance to hypoxia-induced apoptosis but proliferation is inhibited. We suggest that the anti-proliferative effects of hypoxia may limit the ability of detrusor cells to respond to, and compensate for, alterations in their environment contributing to bladder dysfunction.

Apoptosis↗
PubMed2004

Differentiation-induced HL-60 cell apoptosis: a mechanism independent of mitochondrial disruption?

HL-60 cell differentiation into neutrophil like cells is associated with their induction of apoptosis. We investigated the cellular events that occur pre and post mitochondrial permeability transition to determine the role of the mitochondria in the induction of differentiation induced apoptosis. Pro-apoptotic Bax was translocated to and cleaved at the mitochondrial membrane in addition to t-Bid activation. These processes contributed to mitochondrial membrane disruption and the release of cytochrome c and Smac/DIABLO. The release of cytochrome c was caspase independent, as the caspase inhibitor Z-VAD.fmk, which inhibited apoptosis, did not block the release of cytochrome c. In contrast, the release of Smac/DIABLO was partially inhibited by caspase inhibition indicating differential release pathways for these mitochondrial pro-apoptotic factors. In addition to caspase inhibition we assessed the effects of the Bcl-2 anti-apoptotic family on differentiation induced apoptosis. BH4-Bcl-xl-TAT recombinant protein did not delay apoptosis, but did block the release of cytochrome c and Smac/DIABLO. Bcl-2 over-expression also inhibited differentiation induced apoptosis but was associated with the inhibition of the differentiation process. Differentiation mediated mitochondrial release of cytochrome c and Smac/DIABLO, may not trigger the induction of apoptosis, as BH4-Bclxl-TAT blocks the release of pro-apoptotic factors from the mitochondria, but does not prevent apoptosis.

Antigens, CD↗
PubMed2004

Future opportunities for the diagnosis and treatment of prostate cancer.

Despite recent advances, current diagnostic tests and treatment of prostate cancer have limitations. In the last few years, numerous biomolecules have been investigated with the aim of improving diagnosis, including kallikrein-like proteases, growth factors and neuroendocrine markers. Analysis of susceptibility genes has also been a focus of attention. Extensive research into new therapeutic approaches is also underway, including targeting angiogenesis, immune regulation and stromal-epithelial interactions. Gene therapy, gene chip technology and proteomics have emerged as promising innovations. The host of novel diagnostic markers and therapies require appropriate validation, both phenotypical and functional. A further consideration is the need to re-evaluate clinical trial design and end points to facilitate progression of promising targets through the clinical trial process. Overall, the outlook for the treatment of prostate cancer looks promising, with any advances likely to require both a multimodal and multidisciplinary approach.

Clinical Trials as Topic↗
PubMed2004

Gene profiling of in vitro and in vivo models of delayed neutrophil apoptosis: a common pathway?

Mechanisms responsible for the termination of an inflammatory response include the activation of a genetic programme of cellular suicide termed apoptosis, which leads to the elimination of the cellular effectors of acute inflammation, particularly the neutrophil. However, delays in this response result in the persistence of inflammation and the development of inflammatory disorders. Understanding the mechanism that inhibits the process of cell death may be helpful in the treatment of inflammatory disorders. Inflammatory cytokines have been shown to inhibit apoptosis through stabilization of the mitochondria and inhibition of the caspase cascade. To date, how these processes are inhibited remains the central question. We hypothesize that the decision for the delay in neutrophil apoptosis is made through signals delivered on the cell surface, which activate combinations of specific genes that inhibit the cell death pathway. Gene chip microarray experiments were performed in in vivo and in vitro models of delayed neutrophil apoptosis. Analysis has yielded changes in a large number of genes involved in inflammation, metabolism, signalling, mitochondrial function and apoptosis. A number of genes have been identified as suitable targets responsible for the regulation of neutrophil apoptosis and their expression was confirmed by real-time PCR and explored at the level of the protein. Their functional role in the apoptotic response is now being determined. One significant finding is that the gene patterns of delay in vitro and in vivo appear to be different, indicating the possibility for different pathways regulating the delay in neutrophil apoptosis.

Apoptosis↗
PubMed2003

Human nucleus pulposis can respond to a pro-inflammatory stimulus.

STUDY DESIGN: Disc tissue obtained from patients undergoing surgery for scoliosis, lumbar radiculopathy, and discogenic pain was cultured under basal and lipopolysaccharide-stimulated conditions and the medium analyzed for production of a range of pro-inflammatory mediators. OBJECTIVES: This study was conducted to confirm that the human intervertebral disc is capable of responding to a pro-inflammatory stimulus and to identify the principal mediators involved in any response. SUMMARY OF BACKGROUND DATA: Degenerate human disc tissue has been shown to spontaneously secrete a number of pro-inflammatory mediators. The importance of these molecules in the pathophysiology of symptomatic disc degeneration is increasingly recognized. Human nucleus pulposus has been shown to synthesize increased amounts of interleukin (IL)-6, prostaglandin E2 (PGE2), and nitric oxide in response to stimulation with IL-1beta. Murine nucleus pulposus synthesizes increased amounts of IL-1beta, IL-6, IL-10, and granulocyte-macrophage colony-stimulating factor in response to lipopolysaccharide stimulation. Lipopolysaccharide is a potent inducer of tumor necrosis factor-alpha (TNF-alpha), which is thought to play an important role in the pathophysiology of sciatica. To date, human nucleus pulposus has not been shown to secrete TNF-alpha in response to a pro-inflammatory stimulus. METHODS: Human disc tissue obtained from patients undergoing surgery for scoliosis, lumbar radiculopathy, and discogenic pain was cultured under basal and lipopolysaccharide-stimulated conditions and the medium subsequently analyzed for a range of pro-inflammatory mediators. RESULTS: None of the specimens produced any TNF-alpha, IL-1beta, granulocyte-macrophage colony-stimulating factor, or leukotriene B4. Measurable quantities of IL-6, IL-8, PGE2, MCP-1, basic fibroblast growth factor, and trans forming growth factor-beta1 were produced by a number of specimens. Lipopolysaccharide significantly increased IL-6, IL-8, and PGE2 production in both control and degenerate disc tissue. Degenerate disc specimens responded more vigorously to lipopolysaccharide stimulation than scoliotic specimens. CONCLUSIONS: We conclude that both scoliotic and degenerate human nucleus pulposus can respond to an exogenous pro-inflammatory stimulus by secreting increased amounts of IL-6, IL-8, and PGE2 but not TNF-alpha and that degenerate disc tissue is more sensitive to a pro-inflammatory stimulus than its scoliotic counterpart.

Adolescent↗
PubMed2003

Apoptosis in the prostate.

The prostate requires androgens for development and glandular maintenance, dying by the process of apoptosis following their removal. Anti-androgen therapy is targeted to induce this process but eventually fails with the emergence of an androgen independent cancer. These cells have development mechanisms to survive with out androgen impart due to the expression of anti-apoptotic factors.

Androgens↗
PubMed2002

Redox regulation of neutrophil apoptosis.

The persistence of a neutrophil-mediated inflammatory response is due in part to a delay in their spontaneous rates of apoptosis or cell death. Regulating apoptosis has important implications for the resolution of inflammatory disorders, such as the systemic inflammatory response syndrome or acute respiratory distress syndrome. Neutrophils through their primary function of killing bacteria generate large concentrations of reactive oxygen intermediates and have alterations in the levels of antioxidants. Reactive oxygen intermediates and antioxidants are important regulators of the apoptotic caspases, but the mechanisms involved are still under debate and investigation. This review addresses the role of the cellular redox status of neutrophils on the apoptotic cascade leading to cell death.

Animals↗
PubMed2002

Intervertebral discs which cause low back pain secrete high levels of proinflammatory mediators.

Herniated intervertebral disc tissue has been shown to produce a number of proinflammatory mediators and cytokines, but there have been no similar studies using discs from patients with discogenic low back pain. We have compared the levels of production of interleukin-6 (IL-6), interleukin-8 (IL-8) and prostaglandin E2 (PGE2) in disc tissue from patients undergoing discectomy for sciatica (63) with that from patients undergoing fusion for discogenic low back pain (20) using an enzyme-linked immunoabsorbent assay. There was a statistically significant difference between levels of production of IL-6 and IL-8 in the sciatica and low back pain groups (p < 0.006 and p < 0.003, respectively). The high levels of proinflammatory mediator found in disc tissue from patients undergoing fusion suggest that production of proinflammatory mediators within the nucleus pulposus may be a major factor in the genesis of a painful lumbar disc.

Adult↗
PubMed2002

The loss of IAP expression during HL-60 cell differentiation is caspase-independent.

Human promyelocytic leukaemia cells (HL-60) differentiate into neutrophil-like cells that die spontaneously by apoptosis when treated with retinoic acid (RA). Inhibitors of apoptosis proteins (IAP) bind to and inhibit caspases 3, 7, and 9 activity and the induction of apoptosis. In this study, we demonstrate that undifferentiated HL-60 cells express IAP. During their differentiation, IAP expression is decreased at the mRNA and protein levels. In addition, we show that there is a corresponding increase in the expression and functional activity of active caspases 3 and 9. This activity was associated with the cleavage of XIAP, NAIP, and cIAP-2. Most importantly, we demonstrate that blocking caspase activity does not alter the decrease in IAP protein expression during differentiation but prevents caspase activation, IAP cleavage, and the induction of apoptosis. This result shows that the loss of IAP expression is independent of the induction of apoptosis and is solely related to the differentiation process. However, IAP cleavage is caspase-dependent. Terminal differentiation results in an altered apoptotic phenotype that is associated with the induction of HL-60 cell apoptosis.

Apoptosis↗
PubMed2001

Defining a role for the inhibitors of apoptosis proteins in prostate cancer.

The aim of this paper is to review the inhibitors of apoptosis proteins, a recently discovered group of caspase inhibitors. We will briefly review the relevance of apoptosis in prostate cancer and some of the control mechanisms, before describing the structure, function and regulation of these molecules. Lastly, we will consider the evidence for the role that IAPs may have in cancer and the implications for prostate cancer in particular. Prostate Cancer and Prostatic Diseases (2001) 4, 28-32

Journal Article↗