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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have carried out studies on cultured human fibroblasts in an attempt to trace the origins of age-dependent disorders to the cellular and molecular levels. Three interrelated areas are discussed. First, skin donors with diabetes mellitus (a disease complex that features inappropriate hyperglycemia) produce cultured fibroblasts with a moderate reduction in growth capacity, while two inherited disorders of inappropriate hyperglycemia and premature aging, progeria and Werner syndrome, yield fibroblast cultures with more severely impaired growth capacity. Second, there is a decreased response of progeria level and donor age; evidence is presented that this defective hormone responsiveness in aging cells may reside at the hormone receptor on the surface membrane, the cyclic AMP system, the intracellular enzymatic machinery, or all of these sites. Third, tissue factor, a procoagulant that activates the extrinsic clotting mechanism, is more abundant in cells from the premature aging syndromes of progeria and Werner syndrome. Fibroblast aging in vitro may help to explain various concomitants of normal aging and diabetes mellitus including cell dropout, impairment of hormone responsiveness, and increased atherothrombosis.
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PMID:In vitro studies of age-associated diseases. 42 66

In order to trace the origins of age-dependent diseases to the cellular level, we studied cultured human fibroblasts from subjects with 3 discrete inherited disorders and normal controls of various ages. Skin fibroblasts from subjects with progeria and Werner syndrome had a moderate to severe reduction in growth capacity, whereas cells from subjects with diabetes mellitus had a more subtle growth impairment. There was a decreased response of progeric fibroblasts to insulin-like hormones, and in normal cells the response decreased as a function of the passage level and donor age. Tissue factor, a procoagulant, was more abundant in progeric and Werner fibroblasts. An understanding of fibroblast aging in vitro may help us explain various concomitant phenomena of organismic aging such as diabetes mellitus, cell dropout, impaired hormone responsiveness, and increased atherothrombosis.
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PMID:Studies on age-related diseases in cultured skin fibroblasts. 44 74

The replicative capacity of cultured human fibroblasts is discussed in relation to three areas, diabetes mellitus, expression of HL-A antigens, and interactions with polymerizing fibrin. The replicative capacity of cells is dimished in diabetes mellitus and certain related disorders such as progeria and Werner's syndrome, all of which feature accelerated aging. Expression of HL-A antigens is reduced in progeria fibroblasts compared to normal cultures at corresponding stages of passage. Normal cells show more subtle alteration during aging in vitro probably related to clonal heterogeneity and/or selection within mass cultures. Early-passage fibroblasts interact rapidly with polymerizing fibrin to form a mature clot which is then retracted by a process dependent on cellular integrity and active metabolism. Late-passage cultures are less active in both parameters as are fibroblasts from a subject with progeria. These observations, in total, may relate to altered self-recognition and certain autoimmune concomitants of aging in vivo. They may also help to explain impaired wound healing and increased predisposition to atherothrombosis in aging and diabetic individuals. This system of cultured human fibroblasts should serve as an excellent model to investigate the cellular and molecular basis of diabetes mellitus, aging and related pathology.
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PMID:Pathological implications of cell aging in vitro. 108 45

NAD levels markedly increase upon mitogen stimulation of lymphocytes from young subjects. In contrast, lymphocytes from old subjects do not increase NAD levels upon stimulation. A survey of 35 individuals aged 18-79 years revealed a significant age-dependent decrease in the NAD response to mitogen stimulation. No significant differences were noted in lymphocytes from age-matched individuals with Down's syndrome or diabetes mellitus. On the other hand, cultured skin fibroblasts showed elevated NAD levels with age. However, this effect appears to be due to increased size of the cells since the NAD/protein ratio is unchanged. Skin fibroblasts from patients with progeria exhibit much higher levels of NAD and protein per cell than age-matched controls.
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PMID:Changes in NAD levels in human lymphocytes and fibroblasts during aging and in premature aging syndromes. 622 88

The authors survey the modern classification of progeria and report on a 12-year old girl suffering from lipodystrophia totalis and diabetes mellitus (Lawrence-Seip-syndrome). The girl developed sclerodermiform changes at the age of one year, at her 10th year acanthosis nigricans, xanthoma tuberosum Fredrickson hyperlipoproteinaemie IV, later II/B type and finally at an age of 11 1/2 year diabetes mellitus.
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PMID:[Premature aging syndromes with special reference to lipodystrophy (a case report)]. 661 24

Atherosclerosis constitutes the most common medical and surgical problem. This can be manifested clinically as stroke, coronary artery disease, or peripheral vascular disease. In the present review the microscopic appearance of the normal arterial wall, the definition of atherosclerosis and the five theories of atherogenesis are described. These are: the lipid theory, the hemodynamic theory, the fibrin incrustation theory, the nonspecific mesenchymal hypothesis and the response to injury hypothesis. Based on the above theories the sequence of events in atherogenesis is analyzed. The classification of the atherosclerotic lesions according to Stary (types I-VI) and their characteristics appear in a table. The epidemiology and the role of the following risk factors are presented in detail: age, sex, lipid abnormalities, cigarette smoking, hypertension, diabetes mellitus, physical inactivity, alcohol consumption, obesity, and hemostatic factors. In addition, less common genetically determined associations like homocystinuria, Tangier disease, Hutchinson-Gilford syndrome (progeria), Werner's syndrome, radiation induced atherosclerosis and the implications of Chlamydia pneumoniae on the arterial wall are discussed.
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PMID:The genesis of atherosclerosis and risk factors: a review. 1122 92

A number of mouse models have been identified and are being used for aging and age-associated disease research. However, the use of the genetically manipulated mouse model is still a relatively untapped resource for the study of the biology of aging. Genetically altered mice can be powerful tools for biology of aging research because gene expression can be controlled and correlated with established biomarkers. Standard transgene overexpression and gene targeting techniques were modified and used to generate 30 mouse lines during a 4-year period. These lines include models of Werner's syndrome (premature aging or progeria), Alzheimer's disease, other neurodegenerative condition, atherosclerosis, diabetes, immune dysfunction, musculoskeletal disorders, and oxidative stress. These new mouse models are providing additional insights into aging processes and will be useful for developing intervention strategies and collaborative interactions.
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PMID:Generation of genetically altered mouse models for aging studies. 1178 22

Laminopathies are genetic diseases that encompass a wide spectrum of phenotypes with diverse tissue pathologies and result mainly from mutations in the LMNA gene encoding nuclear lamin A/C. Some laminopathies affect the cardiovascular system, and a few (namely, Dunnigan-type familial partial lipodystrophy [FPLD2] and Hutchinson-Gilford progeria syndrome [HGPS]) feature atherosclerosis as a key component. The premature atherosclerosis of FPLD2 is probably related to characteristic proatherogenic metabolic disturbances such as dyslipidemia, hyperinsulinemia, hypertension, and diabetes. In contrast, the premature atherosclerosis of HGPS occurs with less exposure to metabolic proatherogenic traits and probably reflects the generalized process of accelerated aging in HGPS. Although some common polymorphisms of LMNA have been associated with traits related to atherosclerosis, the monogenic diseases FPLD2 and HGPS are more likely to provide clues about new pathways for the general process of atherosclerosis. Dunnigan-type familial partial lipodystrophy and Hutchinson-Gilford progeria syndrome are laminopathies caused by mutation in LMNA that feature atherosclerosis, which is related to proatherogenic metabolic disturbances and to the generalized process of accelerated aging, respectively. These monogenic diseases may provide clues about new pathways for atherogenesis.
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PMID:Laminopathies and atherosclerosis. 1520 20

Lipodystrophies represent a group of diseases characterized by altered body fat repartition and major metabolic alterations with insulin resistance. Genetic forms of partial lipodystrophy are currently recognized as two syndromes with subcutaneous lipoatrophy but preserved or increased fat at the level of face and neck (Dunnigan syndrome or FPLD due to LMNA mutations) and/or abdomen (PPARgamma-linked forms) and are both transmitted as dominant diseases. FPLD is further characterized by muscular hypertrophy, hyperandrogenism, acanthosis nigricans, hepatomegaly with steatosis and at the biological level, marked hypertriglyceridaemia, low HDL cholesterol, insulin resistance and altered glucose tolerance or diabetes. These signs occur after puberty and their prevalence and severity are more marked in female than in male patients. At the genetic level, LMNA mutations concern in most cases the type-A lamin C-terminal domain and more than 80% are heterozygous substitutions located at position 482 (R482W/Q/L). The other locations are G465D, K486N, R582H and R584H. The presence of signs evocative of limb-girdle muscular dystrophy has been reported in patients with typical forms of FPLD. In addition, forms presenting with lipodystrophy and myopathy have been reported for patients with mutations at position R28W, R60G, R62G or R527P. In addition, lipodystrophy, either partial or generalized, can be associated with syndromes of premature ageing like Hutchinson-Gilford progeria or acromandibular dysplasia, but also with other phenotypes, as we described in a patient bearing the LMNA R133L heterozygous substitution.
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PMID:A-type lamin-linked lipodystrophies. 1577 53

Oxidative DNA modifications are frequent in mammalian DNA and have been suggested an important mechanism in carcinogenesis, diabetes and ageing. The foundations for this suggestion are: Evidence for the importance of oxidative DNA modifications in cancer development is: high levels of oxidative lesions in cancer tissue; highly conserved and specific DNA repair systems targeting oxidative lesions; high levels of oxidative DNA lesions in oxidative DNA repair knock-out animals; defective repair of oxidative lesions in cancer-prone progeria syndromes; reduced cancer incidence in populations with high dietary antioxidant intake; and increased oxidative stress to DNA in tobacco smokers. Conflicting evidence for a relation between oxidative stress to DNA and cancer is: disagreement about the true levels and occurrence of the oxidative lesions in vivo; failure to identify the localization of oxidative lesions in important genes, e.g. tumor suppressor and oncogenes; lack of evidence that the oxidative lesions induce mutations in vivo; no cancer development in animals knocked-out for specific DNA repair enzymes in spite of high tissue levels of oxidative lesions; and unchanged cancer rates after antioxidant interventions in large clinical controlled and randomized trials. The rate of DNA oxidation has been estimated from urinary excretion of repair products and it is evident that if these lesions were not repaired, a large part of DNA would be oxidized to a degree not compatible with living. The methodologies by which oxidative DNA modifications are measured cover a wide and different range, advantages and disadvantages will be presented. One particular problem is artificial oxidation, and methods to prevent such artifacts will be presented together with results from a large interlaboratory standardization program. The methodology by which the lesions can be measured is complicated and prone to artifacts during DNA isolation, digestion, derivatization and maybe even during the separation procedure proper prior to detection. A large effort from 20+ laboratories supported by a grant from the EU has reduced artifacts considerably and work towards interlaboratory standardization of the methodology is in progress. The presently agreed "normal" levels of the most frequent known lesion 8-oxodG is about 5 per million dG's in DNA. A comprehensive evaluation of the evidence, from chemistry to clinical and epidemiological trials, linking oxidative modifications to cancer will be given. Finally, an estimate of the quantitative role oxidative DNA modifications play among the multiplicity of other insults is given. While there is no question that all of these oxidative mechanisms do exist, quantitative data on their importance for the human situation do not exist. Prospective human studies that can provide such quantitative data on different mechanisms are underway.
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PMID:Oxidative DNA modifications. 1609 24


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