Sirtuins are genes implicated in cellular and organismal ageing. Consequently, they are speculated to be involved in diseases of ageing including cancer. Various cancers with widely differing prognosis have been shown to have differing and characteristic expression of these genes; however, the relationship between sirtuin expression and cancer progression is unclear. In order to correlate cancer progression and sirtuin expression, we have assessed sirtuin expression as a function of primary cell ageing and compared sirtuin expression in normal, 'nonmalignant' breast biopsies to breast cancer biopsies using real-time polymerase chain reaction (PCR). Levels of SIRT7 expression were significantly increased in breast cancer (Po0.0001). Increased levels of SIRT3 and SIRT7 transcription were also associated with node-positive breast cancer (Po0.05 and Po0.0001, respectively). This study has demonstrated differential sirtuin expression between nonmalignant and malignant breast tissue, with consequent diagnostic and therapeutic implications.
This study has indicated an association between epigenetic status and socio-economic status (SES). This relationship has direct implications for population health and is reflected in further associations between global DNA methylation content and emerging biomarkers of CVD.
BackgroundIt has previously been hypothesized that lower socio-economic status can accelerate biological ageing, and predispose to early onset of disease. This study investigated the association of socio-economic and lifestyle factors, as well as traditional and novel risk factors, with biological-ageing, as measured by telomere length, in a Glasgow based cohort that included individuals with extreme socio-economic differences.MethodsA total of 382 blood samples from the pSoBid study were available for telomere analysis. For each participant, data was available for socio-economic status factors, biochemical parameters and dietary intake. Statistical analyses were undertaken to investigate the association between telomere lengths and these aforementioned parameters.ResultsThe rate of age-related telomere attrition was significantly associated with low relative income, housing tenure and poor diet. Notably, telomere length was positively associated with LDL and total cholesterol levels, but inversely correlated to circulating IL-6.ConclusionsThese data suggest lower socio-economic status and poor diet are relevant to accelerated biological ageing. They also suggest potential associations between elevated circulating IL-6, a measure known to predict cardiovascular disease and diabetes with biological ageing. These observations require further study to tease out potential mechanistic links.
We demonstrate that intravenous delivery of human, or rat, pancreas-derived pathfinder (PDP) cells can totally regenerate critically damaged adult tissue and restore normal function across a species barrier. We have used a mouse model of streptozotocin (STZ)-induced diabetes to demonstrate this. Normoglycemia was restored and maintained for up to 89 days following the induction of diabetes and subsequent intravenous delivery of PDP cells. Normal pancreatic histology also appeared to be restored, and treated diabetic animals gained body weight. Regenerated tissue was primarily of host origin, with few rat or human cells detectable by fluorescent in situ hybridization (FISH). Crucially, the insulin produced by these animals was overwhelmingly murine in origin and was both types I and II, indicative of a process of developmental recapitulation. These results demonstrate the feasibility of using intravenous administration of adult cells to regenerate damaged tissue. Critically, they enhance our understanding of the mechanisms relating to such repair and suggest a means for novel therapeutic intervention in loss of tissue and organ function with age.
Pathfinder cells (PCs), a novel cell type derived from the pancreas of adult rats, have been demonstrated to stimulate recovery of tissue structure and function in two animal models of acute tissue damage to date-streptozotocin (STZ)-induced diabetes and ischemia-reperfusion damage to the kidney. In repaired tissue, PCs and their progeny typically represent only 0.02% of the repaired tissue, suggesting that they act via a paracrine mechanism on native cells in the damaged area. Extracellular vesicles are strong candidates for mediating such a paracrine effect. Therefore, we studied the effects of two PC-derived extracellular vesicle fractions on tissue repair in the STZ diabetes model, one containing primarily microvesicles and the second containing predominantly exosomes. Treatment of STZ-induced diabetic mice with the microvesicles preparation led to blood glucose, insulin, glucagon, and C-peptide levels similar to those found with PC treatment. Furthermore, analysis of the histopathology of the pancreas indicated islet regeneration. In contrast, the exosome fraction demonstrated no repair activity, and STZ diabetic mice treated with exosome preparations had blood glucose values that were indistinguishable from those of vehicle-only treated controls. Therefore, we conclude that exosomes play no part in PC action as detected by this assay, whereas microvesicles provide all or a large component of the paracrine activity of PCs. Because they act to stimulate repair of multiple tissues, PC-derived microvesicles may similarly have the potential to stimulate repair of many damaged tissues, identifying a very significant cell-free therapeutic opportunity in regenerative medicine.
Objectives: Telomere erosion, a feature of biological ageing, is implicated in a wide range of diseases. Its impact on autoimmune diseases remains unclear although autoantibodies against many telomere nucleoprotein components are prevalent in these diseases. We aimed to assess if telomere biology was abnormal in a cohort of patients with limited cutaneous systemic sclerosis (lcSSc). Methods: Telomere lengths in peripheral blood leucocytes (PBL) were determined using Southern blotting methods in a cohort of lcSSc subjects (n = 43; age range 37-80 years) and a control population (n = 107; age range 21-65 years). Results: Telomere lengths in lcSSc subjects were longer than controls (p,0.001), did not show age-related telomere erosion and differed significantly from agematched controls only after 50 years of age (p,0.001).Conclusions: This is the first report of maintenance of telomere lengths in an autoimmune disease state. These data indicate aberrant telomere biology and irregular biological ageing from the fifth decade of life. These findings provide insight into compromised DNA damage repair in lcSSc. Whether these observations indicate a causal or consequential relationship requires further investigation. This in turn, may provide potential novel targets for therapeutic intervention.
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