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1.
J Endocrinol Invest ; 39(11): 1347-1355, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27614458

RESUMO

PURPOSE: Several studies implicated a crosstalk between bone and fat in the pathogenesis of osteoporosis. Few studies indicated an association between adiponectin and omentin-1 on the bone remodeling process and bone mineral density, and suggested osteoprotegerin (OPG) as a mediator of this relationship. However, only limited evidence on this relationship is available in humans. Therefore, this study aimed to investigate the association between omentin-1, adiponectin and broadband ultrasound attenuation (BUA) in peri-/premenopausal and postmenopausal women, and to assess the role of OPG as a possible mediator. METHODS: Data from the German population-based EPIC-Potsdam cohort comprising 637 women were analyzed. Multivariable-adjusted ANCOVA including age, BMI, waist circumference, smoking status, education, physical activity, adiponectin or omentin-1 and hormone use was used to investigate potential relationships between the adipokines and BUA levels. A mediation analysis assessed the mediating effect of OPG on the association of BUA and omentin-1 levels. RESULTS: Peri-/premenopausal women had higher BUA levels (112.5 ± 10.1 dB/MHz), compared to postmenopausal women (106.3 ± 10.0 dB/MHz). In peri-/premenopausal women neither adiponectin nor omentin-1 was significantly associated with BUA. In postmenopausal women, adiponectin was not associated with BUA, but 10 % increase in the omentin-1 concentration was significantly associated with 0.44 dB/MHz lower BUA levels (p = 0.01). Omentin-1 was positively associated with OPG (p = 0.02); however, OPG was not significantly related to BUA (p = 0.62). CONCLUSION: Our study provides evidence for an inverse association between circulating omentin-1 and BUA levels in postmenopausal women. However, the present findings do not support a mediating effect of OPG in the adipose tissue-bone pathway.


Assuntos
Adiponectina/sangue , Biomarcadores/análise , Densidade Óssea , Citocinas/sangue , Lectinas/sangue , Osteoporose/diagnóstico , Osteoprotegerina/sangue , Ultrassonografia/métodos , Adulto , Feminino , Proteínas Ligadas por GPI/sangue , Humanos , Pessoa de Meia-Idade , Osteoporose/sangue , Pós-Menopausa , Pré-Menopausa , Estudos Prospectivos , Inquéritos e Questionários
2.
Zentralbl Chir ; 139(1): 89-97, 2014 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-23460104

RESUMO

BACKGROUND: Regarding anticoagulant therapies there has been a remarkable shift in recent years. The objective of this brief overview is to provide relevant information and guidelines on the advantages and disadvantages of novel anticoagulants addressing specifically the surgical disciplines. Hitherto, conventional anticoagulant therapy in patients with a high thrombosis risk was largely limited to heparins and vitamin-K antagonists (VKA). Their modes of action, the difficulties in managing VKAs (e.g., bridging therapy) and the risk of HIT (heparin-induced thrombocytopenia) associated with heparins are briefly discussed. Novel anticoagulants supposedly eliminate these obstacles. Fondaparinux (Arixtra®) is a fully synthetic pentasaccharide which acts like a heparin but has an increased half life. Fondaparinux has a diminished risk of HIT. However, no specific antidote is currently available for Fondaparinux. The novel oral anticoagulants (NOAC) dabigatran etexilat (Pradaxa®), rivaroxaban (Xarelto®) and apixaban (Eliquis®), also known as "direct" anticoagulants, act independently from antithrombin by inhibiting thrombin, as in the case of dabigatran, or by inhibiting factor Xa, as in the case of rivaroxaban and apixaban. It is assumed that they are suitable for long-term use and do not require laboratory monitoring. Nevertheless, clinical experience is very limited and caution rather than quick conclusions is necessary. Two major drawbacks are on the one hand the risk of drug accumulation in kidney and/or liver disease and, on the other hand, the lack of specific antidotes. In addition, interactions with other medication may have unexpected effects on serum drug levels. Therefore, the analysis of drug levels in the plasma may become necessary in subgroups of patients. DISCUSSION AND CONCLUSION: Studies establishing clear recommendations for the desirable and measurable reference range are needed. Similarly, evidence-based recommendations regarding perioperative prevention of thrombosis are required ("bridging": yes or no?). Irrespective of these issues, the authors predict a further expansion of the use of NOACs.


Assuntos
Anticoagulantes/uso terapêutico , Heparina/uso terapêutico , Pirazóis/uso terapêutico , Piridonas/uso terapêutico , Trombose/tratamento farmacológico , Administração Oral , Anticoagulantes/efeitos adversos , Anticoagulantes/farmacocinética , Benzimidazóis/efeitos adversos , Benzimidazóis/uso terapêutico , Testes de Coagulação Sanguínea , Dabigatrana , Interações Medicamentosas , Inibidores do Fator Xa , Fondaparinux , Heparina/farmacocinética , Humanos , Coeficiente Internacional Normatizado , Falência Hepática/sangue , Falência Hepática/complicações , Taxa de Depuração Metabólica/fisiologia , Morfolinas/efeitos adversos , Morfolinas/uso terapêutico , Assistência Perioperatória , Polissacarídeos/efeitos adversos , Polissacarídeos/farmacocinética , Polissacarídeos/uso terapêutico , Pirazóis/farmacocinética , Piridinas/efeitos adversos , Piridinas/uso terapêutico , Piridonas/farmacocinética , Insuficiência Renal/sangue , Insuficiência Renal/complicações , Rivaroxabana , Tiofenos/efeitos adversos , Tiofenos/uso terapêutico , Trombocitopenia/sangue , Trombocitopenia/induzido quimicamente , Trombocitopenia/tratamento farmacológico , Trombose/sangue , Trombose/prevenção & controle , Vitamina K/antagonistas & inibidores
3.
Mycotoxin Res ; 40(2): 279-293, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38498144

RESUMO

Humans and their immune system are confronted with mold-contaminated food and/or mold-contaminated air in daily life and indoor activities. This results in metabolic stress and unspecific disease symptoms. Other studies provided evidence that exposure to mold is associated with the etiology of allergies. Deoxynivalenol (DON) is of great concern due to its frequent occurrence in toxically relevant concentrations. The exposure to this toxin is a permanent health risk for both humans and farm animals because DON cannot be significantly removed during standard milling and processing procedures. However, the direct effect on immunity or hematology is poorly defined because most investigations could not separate the effect of DON-contaminated feed intake. Due to the widespread distribution of DON after rapid absorption, it is not surprising that DON is known to affect the immune system. The immune system of the organism has one important function, to defend against the invasion of unknown substances/organisms. This study shows for the first time a synergistic effect of both-low physiological DON-doses in combination with low LPS-doses with the focus on the IL-8 expression on protein and RNA level. Both doses were found in vivo. IL-8 together with other anorectic cytokines like IL-1ß can affect the food intake and anorexia. We could also show that a calcium-response is not involved in the increased IL-8 production after acute DON stimulation with high or low concentrations.


Assuntos
Interleucina-8 , Monócitos , Transdução de Sinais , Tricotecenos , Tricotecenos/toxicidade , Interleucina-8/metabolismo , Transdução de Sinais/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Animais , Biossíntese de Proteínas/efeitos dos fármacos , Humanos , Células Cultivadas
4.
Int J Obes (Lond) ; 37(1): 135-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22310469

RESUMO

OBJECTIVE: The A-allele of the fat mass and obesity-associated (FTO) gene variant rs9939609 has been associated with increased body weight, whereas no effect on weight loss during weight reduction programs has been observed. We questioned whether the AA-genotype interferes with weight stabilization after weight loss. DESIGN: We conducted a monocentric, longitudinal study involving obese individuals. The FTO gene variant rs9939609 was genotyped in participants attending a weight reduction program that was divided into two phases: a weight reduction period with formula diet (12 weeks) and a weight maintenance phase (40 weeks). Body weight, body mass index (BMI), blood pressure and concentrations of blood glucose, total cholesterol, low-density lipoprotein, high-density lipoprotein and triglycerides were determined in week 0 (T(0)), after 12 weeks (T(1)) and at the end in week 52 (T(2)). SUBJECTS: A total of 193 obese subjects aged between 18 and 72 years (129 female, 64 male; initial body weight: 122.4±22.3 kg, initial BMI: 41.8±6.7 kg m(-2)) were included. RESULTS: Genotyping revealed 32.1% TT-, 39.4% AT- and 28.5% AA-genotype carriers. At T (0), carriers of the AA-genotype had significantly higher body weight (P=0.04) and BMI (P=0.005) than carriers of the TT-genotype. Of the 193 participants, 68 discontinued and 125 completed the program. Dropout rate was not influenced by genotype (P=0.33). Completers with AA-genotype showed significantly lower additional weight loss during the weight maintenance phase than TT-genotype carriers (P=0.02). Furthermore, among participants facing weight regain during weight maintenance (n=52), more subjects were carrying the AA-genotype (P=0.006). No influence of genotype on weight reduction under formula diet was observed (P=0.32). CONCLUSION: In this program, the AA-genotype of rs9939609 was associated with a higher initial body weight and did influence success of weight stabilization. Thus, emphasizing the maintenance phase during a weight reduction program might result in better success for AA-genotype carriers.


Assuntos
Peso Corporal/genética , Obesidade/genética , Proteínas/genética , Aumento de Peso/genética , Redução de Peso/genética , Adolescente , Adulto , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Glicemia/metabolismo , Índice de Massa Corporal , Estudos Transversais , Feminino , Predisposição Genética para Doença , Variação Genética , Genótipo , Alemanha/epidemiologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/epidemiologia , Projetos Piloto , Triglicerídeos/sangue
5.
Eur J Med Res ; 16(8): 375-80, 2011 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-21813380

RESUMO

BACKGROUND: Postoperative hyperthyroidism occurs in approximately one third of patients following parathyroidectomy due to primary hyperparathyroidism (PHP), but has only rarely been described in secondary hyperparathyroidism (SHP). The frequency, course, and laboratory markers of postoperative hyperthyroidism in SHP remain unknown. Our purpose was to evaluate the frequency and the clinical course of postoperative hyperthyroidism following surgery of SHP and to determine the diagnostic value of thyroglobulin in this setting. MATERIAL AND METHODS: A total of 40 patients undergoing parathyroidectomy because of SHP were included in this study. Thyroid stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and thyroglobulin (Tg) were determined one day before and on day 1, 3, 5, 10, and 40 after surgery. At each of these visits patients were clinically evaluated for signs or symptoms of hyperthyroidism. RESULTS: Biochemical evidence of hyperthyroidism was evident in 77% of patients postoperatively despite of preoperatively normal serum levels. TSH dropped from 1.18 ± 0.06mU/L to 0.15 ± 0.07mU/L (p = 0.0015). Free triiodothyronine (fT3) and fT4 levels increased from 2.86 ± 0.02ng/L and 10.32 ± 0.13ng/L, respectively, to their maximum of 4.83 ± 0.17ng/L and 19.35 ± 0.58ng/L, respectively. Thyroglobulin levels rose from 3.8 ± 0.8ng/mL to 111.8 ± 45.3ng/mL (p<0.001). At day 40 all thyroid related laboratory values were within normal range. Correlation analysis of postoperative values revealed significant correlations for lowest TSH (r = -0.32; p = 0.038), and highest fT3 (r = 0.55; p<0.001) and fT4 levels (r = 0.67; p<0.001) with Tg. CONCLUSION: Transient hyperthyroidism is frequent after parathyroidectomy for SHP with Tg being a suitable marker. Awareness of this self-limiting disorder is important to avoid inappropriate and potentially harmful treatment.


Assuntos
Hiperparatireoidismo Secundário/cirurgia , Hipertireoidismo/diagnóstico , Adulto , Feminino , Humanos , Hiperparatireoidismo Secundário/complicações , Hiperparatireoidismo Secundário/metabolismo , Hipertireoidismo/complicações , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Prospectivos , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Tireoglobulina/metabolismo , Tireotropina/metabolismo , Tiroxina/metabolismo , Fatores de Tempo , Tri-Iodotironina/metabolismo
6.
Hamostaseologie ; 31(3): 179-84, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21691672

RESUMO

Coagulation proteases control cellular homeostasis beyond haemostasis. While the role of coagulation proteases in regulating vascular healing and thrombosis is well established, the mechanism underlying the receptor-dependent regulation of cellular function remain incompletely understood. In particular, the opposing effects of the protease-activated receptor 1 (PAR-1), dependent on the activating proteases thrombin or activated protein C generated a conundrum researchers only recently have begun to decipher. The net-effect (cellular perturbation vs. cellular protection) depends on co-receptors involved, the concentration of the activating protease, the temporal context of receptor activation, and a dynamic process of receptor rearrangement upon receptor activation. The latter scenario recruits receptors to a cytoprotective signalling pathways. Recent insights into these mechanisms are summarized in this article.


Assuntos
Adaptação Fisiológica/imunologia , Coagulação Sanguínea/imunologia , Vasos Sanguíneos/imunologia , Citoproteção/imunologia , Hemostasia/imunologia , Peptídeo Hidrolases/imunologia , Transdução de Sinais/imunologia , Animais , Vasos Sanguíneos/citologia , Humanos , Modelos Cardiovasculares , Modelos Imunológicos
7.
J Clin Invest ; 108(4): 537-46, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11518727

RESUMO

The thrombomodulin (TM) gene was ablated in mice in a cell type-restricted manner from vascular endothelium by Cre-recombinase-mediated excision controlled by the endothelial cell lineage-specific Tie2 promoter. Forty percent of mutant (TMLox-) mice display a distinct lethal embryonic phenotype not observed in completely TM-deficient embryos. The remaining 60% of TMLox mice survive beyond birth, but invariably succumb to a severe hypercoagulable state and massive thrombosis after 3 weeks, terminating in a lethal consumptive coagulopathy. The progression of thrombosis was age- and sex-dependent. Disruption of the TM/protein C pathway was not associated with a latent proinflammatory state. Disease onset and progression could be prevented by warfarin anticoagulation. These results show that in mice, loss of endothelial cell TM function causes spontaneous and fatal thrombosis in the arterial and venous circulation, resulting from unfettered activation of the coagulation system. The combination of complete disease penetrance, uniform disease onset at young age, large vessel thrombosis of the extremities and multiple organ systems, and consumptive coagulopathy as the disease end-point provides a unique mouse model of human thrombotic disease.


Assuntos
Coagulação Sanguínea/fisiologia , Coagulação Intravascular Disseminada/etiologia , Endotélio Vascular/metabolismo , Proteína C/fisiologia , Trombomodulina/deficiência , Trombose/etiologia , Fatores Etários , Animais , Anticoagulantes/uso terapêutico , Cardiomegalia/etiologia , Modelos Animais de Doenças , Progressão da Doença , Coagulação Intravascular Disseminada/tratamento farmacológico , Feminino , Regulação da Expressão Gênica , Marcação de Genes , Genes Letais , Genes Sintéticos , Humanos , Integrases/genética , Masculino , Camundongos , Camundongos Transgênicos , Miocárdio/patologia , Especificidade de Órgãos , Receptores Proteína Tirosina Quinases/genética , Receptor TIE-2 , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/fisiologia , Recombinação Genética , Maturidade Sexual , Trombomodulina/genética , Trombomodulina/fisiologia , Trombofilia/tratamento farmacológico , Trombofilia/etiologia , Trombose/prevenção & controle , Proteínas Virais/genética , Varfarina/uso terapêutico
8.
Exp Clin Endocrinol Diabetes ; 115(8): 483-90, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17853330

RESUMO

Testing of autoantibodies in individuals at risk of developing or being newly diagnosed with diabetes mellitus is currently of very limited clinical value. However, clinical studies evaluating new therapeutic options for the delay or treatment of type 1 diabetes mellitus require sensitive, specific, and reliable assays for autoimmune antibodies associated with diabetes mellitus. With immune modulatory treatment of pre-diabetes mellitus on the horizon the need of reliable assays is evident. In addition, determination of autoimmune antibodies in diabetes mellitus facilitates studies investigating the pathophysiology underlying this disease. Clinicians and researchers should be aware of the tests available, their limitations, their clinical relevance, and their indications. This review focuses on the current knowledge about antibody assays for diabetes associated autoimmunity, their clinical value, their role in diagnosing and predicting autoimmune associated diabetes mellitus, and research applications.


Assuntos
Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus/imunologia , Adulto , Autoimunidade , Criança , Diabetes Mellitus/sangue , Diabetes Mellitus/epidemiologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/epidemiologia , Humanos , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/patologia , Valores de Referência , Fatores de Risco
9.
Hamostaseologie ; 27(4): 263-7, 2007 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-17938764

RESUMO

The availability of mice with defined defects within the hemostatic system enabled researchers to identify a role the coagulation system for embryonic and placental development. However, the role of platelets during development has only recently been experimentally addressed, giving some insight into potential functions of platelets during development. Thus, a quantitative embryonic platelet defect (severe thrombopenia secondary to NF-E2 deficiency) is associated with an embryonic growth retardation and reduced vascularisation of the placenta. Maternal platelet deficiency is associated with placental haemorrhage, which, however, does not impair embryonic or maternal survival. In vitro studies established that platelets or platelet conditioned medium regulate the invasive properties of human extravillous trophoblast cells and induce a phenotypical switch of trophoblast cells. These data imply that platelets are of relevance during placentation. Conversely, platelets and the formation of platelet-fibrin aggregates are dispensable for the development of the embryo proper, establishing that the lethal phenotypes observed in some embryos lacking coagulation regulators does not result from an inability to form platelet-fibrin aggregates, but likely reflects altered protease dependent signaling during vascular development.


Assuntos
Plaquetas/fisiologia , Desenvolvimento Embrionário/fisiologia , Placenta/fisiologia , Feminino , Sangue Fetal/fisiologia , Humanos , Masculino , Gravidez , Reprodução
10.
J Thromb Haemost ; 15(7): 1273-1284, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28671351

RESUMO

A homeostatic function of the coagulation system in regard to hemostasis is well established. Homeostasis of blood coagulation depends partially on protease activated receptor (PAR)-signaling. Beyond coagulation proteases, numerous other soluble and cell-bound proteases convey cellular effects via PAR signaling. As we learn more about the mechanisms underlying cell-, tissue-, and context-specific PAR signaling, we concurrently gain new insights into physiological and pathophysiological functions of PARs. In this regard, regulation of cell and tissue homeostasis by PAR signaling is an evolving scheme. Akin to the control of blood clotting per se (the fibrin-platelet interaction) coagulation proteases coordinately regulate cell- and tissue-specific functions. This review summarizes recent insights into homeostatic regulation through PAR signaling, focusing on blood coagulation proteases. Considering the common use of drugs altering coagulation protease activity through either broad or targeted inhibitory activities, and the advent of PAR modulating drugs, an in-depth understanding of the mechanisms through which coagulation proteases and PAR signaling regulate not only hemostasis, but also cell and tissue homeostasis is required.


Assuntos
Coagulação Sanguínea , Homeostase , Peptídeo Hidrolases/metabolismo , Receptores Ativados por Proteinase/metabolismo , Transdução de Sinais , Animais , Asma/diagnóstico , Asma/genética , Sistema Nervoso Central , Células-Tronco Hematopoéticas/metabolismo , Humanos , Hipersensibilidade/diagnóstico , Hipersensibilidade/genética , Rim/fisiologia , Camundongos , Perfusão , Pele/metabolismo , Pele/patologia , Trombina/química
11.
Exp Biol Med (Maywood) ; 242(14): 1412-1423, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28661206

RESUMO

Data from animal experiments and clinical investigations suggest that components of the renin-angiotensin system are markedly affected by sex hormones. However, whether estrogen affects human atrial myocardium has not been investigated yet. In this study, we determined the effects of estrogen on key components of atrial renin-angiotensin system: angiotensin-converting enzyme, responsible for generation of angiotensin II and angiotensin-converting enzyme 2, counteracting majority of AngII effects, and different renin-angiotensin system receptors, AT1R, AT2R, and MAS. First, the expression levels of estrogen receptors mRNA were determined in right atrial appendages obtained from patients undergoing heart surgery. The amounts of estrogen receptor α and estrogen receptor ß mRNA were similar between women ( n = 14) and men ( n = 10). Atrial tissue slices (350 µm) were prepared from male donors which were exposed to estrogen (1-100 nM; n = 21) or stimulated at 4 Hz for 24 h in the presence or absence of 100 nM estrogen ( n = 16), respectively. The administration of estrogen did not change mRNA levels of estrogen receptors, but activated MAP kinases, Erk1/2. Furthermore, estrogen increased the amounts of angiotensin-converting enzyme 2-mRNA (1.89 ± 0.23; P < 0.05) but reduced that of angiotensin-converting enzyme-mRNA (0.78 ± 0.07, P < 0.05). In addition, the transcript levels of AT2R and MAS were upregulated by estrogen. Pacing of tissue slices significantly increased the angiotensin-converting enzyme/angiotensin-converting enzyme 2 ratio at both the mRNA and protein level. During pacing, administration of estrogen substantially lowered the angiotensin-converting enzyme/angiotensin-converting enzyme 2 ratio at the transcript (0.92 ± 0.21 vs. 2.12 ± 0.27 at 4 Hz) and protein level (0.94 ± 0.20 vs. 2.14 ± 0.3 at 4 Hz). Moreover, estrogen elicited anti-inflammatory and anti-oxidative effects on renin-angiotensin system-associated downstream effectors such as pro-oxidative LOX-1 and pro-inflammatory ICAM-1. An antagonist of estrogen receptor α reversed these anti-inflammatory and anti-oxidative effects of estrogen significantly. Overall, our results demonstrated that estrogen modifies the local renin-angiotensin system homeostasis and achieves protective effects in atrial myocardium from elderly men. Impact statement The present study demonstrates that estrogen affects the human atrial myocardium and mediates protective actions through estrogen receptors-(ER) dependent signaling. Estrogen substantially modulates the local RAS via downregulation of ACE and simultaneous upregulation of ACE2, AT2R and MAS expression levels. This is indicative of a shift of the classical RAS/ACE axis to the alternative, protective RAS/ACE2 axis. In support of this view, estrogen attenuated the expression of RAS-associated downstream effectors, LOX-1, and ICAM-1. A specific antagonist of ERα reversed the anti-inflammatory and anti-oxidative effects of estrogen in paced and non-paced atrial tissue slices. In summary, our data demonstrate the existence of protective effects of estrogen in atrial tissue from elderly men which are at least in part, mediated by the regulation of local RAS homeostasis.


Assuntos
Estrogênios/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Miocárdio/enzimologia , Miocárdio/patologia , Peptidil Dipeptidase A/análise , Idoso , Enzima de Conversão de Angiotensina 2 , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , RNA Mensageiro/análise , Receptores de Estrogênio/análise , Sistema Renina-Angiotensina/efeitos dos fármacos
12.
J Thromb Haemost ; 14(11): 2212-2226, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27590316

RESUMO

Essentials The role of protein C (PC) activation in experimental autoimmune encephalitis (EAE) is unknown. PC activation is required for mitochondrial function in the central nervous system. Impaired PC activation aggravates EAE, which can be compensated for by soluble thrombomodulin. Protection of myelin by activated PC or solulin is partially independent of immune-modulation. SUMMARY: Background Studies with human samples and in rodents established a function of coagulation proteases in neuro-inflammatory demyelinating diseases (e.g. in multiple sclerosis [MS] and experimental autoimmune encephalitis [EAE]). Surprisingly, approaches to increase activated protein C (aPC) plasma levels as well as antibody-mediated inhibition of PC/aPC ameliorated EAE in mice. Hence, the role of aPC generation in demyelinating diseases and potential mechanisms involved remain controversial. Furthermore, it is not known whether loss of aPC has pathological consequences at baseline (e.g. in the absence of disease). Objective To explore the role of thrombomodulin (TM)-dependent aPC generation at baseline and in immunological and non-immunological demyelinating disease models. Methods Myelination and reactive oxygen species (ROS) generation were evaluated in mice with genetically reduced TM-mediated protein C activation (TMPro/Pro ) and in wild-type (WT) mice under control conditions or following induction of EAE. Non-immunological demyelination was analyzed in the cuprizone-diet model. Results Impaired TM-dependent aPC generation already disturbs myelination and mitochondrial function at baseline. This basal phenotype is linked with increased mitochondrial ROS and aggravates EAE. Reducing mitochondrial ROS (p66Shc deficiency), restoring aPC plasma levels or injecting soluble TM (solulin) ameliorates EAE in TMPro/Pro mice. Soluble TM additionally conveyed protection in WT-EAE mice. Furthermore, soluble TM dampened demyelination in the cuprizone-diet model, demonstrating that its myelin-protective effect is partially independent of an immune-driven process. Conclusion These results uncover a novel physiological function of TM-dependent aPC generation within the CNS. Loss of TM-dependent aPC generation causes a neurological defect in healthy mice and aggravates EAE, which can be therapeutically corrected.


Assuntos
Sistema Nervoso Central/metabolismo , Mitocôndrias/metabolismo , Bainha de Mielina/química , Proteína C/metabolismo , Trombomodulina/sangue , Animais , Encéfalo/metabolismo , Cardiolipinas/química , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Humanos , Sistema Imunitário , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Neurônios , Estresse Oxidativo , Células PC12 , Fenótipo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Solubilidade , Trombomodulina/química
13.
Arterioscler Thromb Vasc Biol ; 21(9): 1531-7, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11557684

RESUMO

Mutations in the gene encoding thrombomodulin (TM), a thrombin regulator, are suspected risk factors for venous and arterial thrombotic disease. We have previously described the generation of TM(Pro/Pro) mice carrying a TM gene mutation that disrupts the TM-dependent activation of protein C. Here, it is shown that inbred C57BL/6J TM(Pro/Pro) mice exhibit a hypercoagulable state and an increased susceptibility to thrombosis and sepsis. Platelet thrombus growth after FeCl(3)-induced acute endothelial injury was accelerated in mutant mice. Vascular stasis after permanent ligation of the carotid artery precipitated thrombosis in mutant but not in normal mice. Mutant mice showed increased mortality after exposure to high doses of endotoxin and demonstrated altered cytokine production in response to low-dose endotoxin. The severity of the hypercoagulable state and chronic microvascular thrombosis caused by the TM(Pro) mutation is profoundly influenced by mouse strain-specific genetic differences between C57BL/6 and 129SvPas mice. These data demonstrate that in mice, TM is a physiologically relevant regulator of platelet- and coagulation-driven large-vessel thrombosis and modifies the response to endotoxin-induced inflammation. The phenotypic penetrance of the TM(Pro) mutation is determined by as-yet-uncharacterized genetic modifiers of thrombosis other than TM.


Assuntos
Trombomodulina/genética , Trombomodulina/fisiologia , Trombose/etiologia , Animais , Coagulação Sanguínea , Trombose das Artérias Carótidas/induzido quimicamente , Trombose das Artérias Carótidas/patologia , Cloretos , Citocinas/biossíntese , Compostos Férricos , Fibrina/metabolismo , Predisposição Genética para Doença , Ligadura , Lipopolissacarídeos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação , Sepse/induzido quimicamente , Sepse/imunologia , Análise de Sobrevida , Trombose/sangue , Trombose/patologia
14.
J Thromb Haemost ; 1(7): 1515-24, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12871287

RESUMO

Since its discovery as a critical cofactor in the initiation of the protein C (PC) anticoagulant pathway [1,2], biochemical and structural investigations, combined with in vivo analyses of genetically engineered mice have revealed new, and in part PC- and thrombin-independent aspects of thrombomodulin (TM) function in fibrinolysis and inflammation, and in embryogenesis. This review summarizes more recent structural and functional investigations of TM, gives an overview of the association of TM gene polymorphisms with human disease, and provides a synopsis of what is know about TM function in disease states of thrombosis, stroke, arteriosclerosis, and cancer. Newly emerging aspects of TM function in inflammation and embryogenesis are presented and discussed in detail.


Assuntos
Trombomodulina/genética , Trombomodulina/fisiologia , Animais , Anticoagulantes/metabolismo , Humanos , Modelos Biológicos , Neoplasias/metabolismo , Polimorfismo Genético , Proteína C/metabolismo , Acidente Vascular Cerebral/metabolismo , Trombina/metabolismo , Trombomodulina/metabolismo , Trombose/metabolismo
15.
J Thromb Haemost ; 2(8): 1368-79, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15304043

RESUMO

Studies of mice with genetic deficits in specific coagulation factors have shown that many, but not all, components of the hemostatic system serve an essential role in mouse embryogenesis and pregnancy. Although the developmental failures observed in these mice are typically associated with severe hemorrhage, it is uncertain whether the role of coagulation factors in embryogenesis and reproduction is specifically tied to their function in thrombus formation and prevention of blood loss (i.e. hemostasis). Here, we show (i) that a complete loss of fibrinogen- and platelet-dependent hemostatic capacity does not reproduce the developmental defects occurring in mice with either deficits in thrombin generation or unfettered thrombin consumption; (ii) that the essential role of fibrinogen in the maintenance of pregnancy does not involve interaction with platelets; and (iii) that the previously described in utero growth retardation of gene-targeted mice lacking NF-E2, a transcription factor critical for megakaryopoieis, is not caused by a loss of platelet-dependent hemostatic function. In addition, we demonstrate (iv) that fibrinogen can confer physiologically relevant hemostatic function in the absence of platelets, but that a complete loss of hemostatic capacity results if a combined absence of these components is genetically imposed. These findings support the notion that the function of coagulation factors for in utero development and pregnancy is mechanistically distinct from their ability to mediate the formation of hemostatic platelet-fibrin(ogen) aggregates.


Assuntos
Plaquetas/metabolismo , Embrião de Mamíferos/fisiologia , Fibrinogênio/metabolismo , Difosfato de Adenosina/metabolismo , Animais , Colágeno/metabolismo , Cruzamentos Genéticos , Proteínas de Ligação a DNA/genética , Fatores de Ligação de DNA Eritroide Específicos , Fibrinogênio/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Genótipo , Hemostasia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator de Transcrição NF-E2 , Subunidade p45 do Fator de Transcrição NF-E2 , Placenta/metabolismo , Reação em Cadeia da Polimerase , Reprodução , Fatores de Tempo , Fatores de Transcrição/genética , Transgenes , Saco Vitelino/metabolismo
16.
Diabetes Res Clin Pract ; 52(3): 175-83, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11323087

RESUMO

Oxidative stress plays a central role in the pathogenesis and progression of late microangiopathic complications (diabetic nephropathy) in diabetes mellitus. Previous studies suggested that treatment of diabetic patients with the antioxidant alpha-lipoic acid reduce oxidative stress and urinary albumin excretion. In this prospective, open and non-randomized study, the effect of alpha-lipoic acid on the progression of endothelial cell damage and the course of diabetic nephropathy, as assessed by measurement of plasma thrombomodulin and urinary albumin concentration (UAC), was evaluated in 84 patients with diabetes mellitus over 18 months. Forty-nine patients (34 with Type 1 diabetes, 15 with Type 2 diabetes) had no antioxidant treatment and served as a control group. Thirty-five patients (20 with Type 1 diabetes, 15 with Type 2 diabetes) were treated with 600 mg alpha-lipoic acid per day. Only patients with an urinary albumin concentration <200 mg/l were included into the study. After 18 months of follow up, the plasma thrombomodulin level increased from 35.9+/-9.5 to 39.7+/-9.9 ng/ml (P<0.05) in the control group. In the alpha-lipoic acid treated group the plasma thrombomodulin level decreased from 37.5+/-16.2 to 30.9+/-14.5 ng/ml (P<0.01). The UAC increased in patients without alpha-lipoic acid treatment from 21.2+/-29.5 to 36.9+/-60.6 ng/l (P<0.05), but was unchanged with alpha-lipoic acid. It is postulated that the significant decrease in plasma thrombomodulin and failure of UAC to increase observed in the alpha-lipoic acid treated group is due to antioxidative effects of alpha-lipoic acid, and if so that oxidative stress plays a central role in the pathogenesis of diabetic nephropathy. Furthermore, progression of the disease might be inhibited by antioxidant drugs. A placebo-controlled study is needed.


Assuntos
Albuminúria , Antioxidantes/uso terapêutico , Nefropatias Diabéticas/fisiopatologia , Endotélio Vascular/fisiopatologia , Ácido Tióctico/uso terapêutico , Trombomodulina/sangue , Biomarcadores/sangue , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 1/urina , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/urina , Nefropatias Diabéticas/prevenção & controle , Nefropatias Diabéticas/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Fatores de Tempo
17.
Exp Clin Endocrinol Diabetes ; 112(3): 135-41, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15052533

RESUMO

Several polymorphisms have been identified in the RAGE-promoter region that might modulate the outcome of disease. Here we analyse the association of a 63bp deletion (delta63) spanning from bp - 407 to bp - 345 with diabetic nephropathy. The deletion was determined using the polymerase chain reaction (PCR) in a cross-sectional study with 1087 patients with type 1 diabetes (n = 559) and type 2 diabetes (n = 528). 475 patients with osteoporosis served as disease independent control. The prevalence of the heterozygous genotype did not significantly differ between the three groups (type 1: 2.15 %, type 2: 2.27 %, controls: 1.47 %), indicating that heterozygous delta63 is not related to the manifestation of diabetes. Homozygous carriers were not identified in this study. The heterozygous delta63 genotype, was associated with a reduced prevalence of diabetic nephropathy in patients with type 2 diabetes (OR = 0.06; 95 % CI: [0.05, 0.07]), but not in patients with type 1 (OR = 1.49; 95 % CI: [1.14, 1.94]). We conclude, that patients with type 2 diabetes and the 63bp deletion in the promoter of RAGE seem to be protected from diabetic nephropathy. The observed difference between type 1 and type 2 diabetes might point to diverse pathomechanisms of nephropathy in both types of diabetes.


Assuntos
Diabetes Mellitus Tipo 2/genética , Nefropatias Diabéticas/genética , Regiões Promotoras Genéticas/genética , Deleção de Sequência , Diabetes Mellitus Tipo 1/genética , Nefropatias Diabéticas/prevenção & controle , Genótipo , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Genético/genética , Polimorfismo Conformacional de Fita Simples , Prevalência , Receptor para Produtos Finais de Glicação Avançada/genética , Valores de Referência , Risco
18.
Vasa ; 28(3): 172-80, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10483322

RESUMO

BACKGROUND: In diabetic patients endothelial dysfunction is reflected by an increased urinary albumine excretion, which can be reduced by ACE-inhibitors. No data are available showing a endothelial-protective effect by determining a marker reflecting endothelial cell-damage. PATIENTS AND METHODS: The effect of angiotensin converting enzyme inhibitor (ACEI) (ramipril) treatment on the progression of endothelial cell damage,--assessed by measurement of plasma-thrombomodulin (TM),--was investigated in an open, non randomized, prospective pilot study over a period of 18 months in diabetic patients. 87 patients with an urinary albumin concentration (UAC) below 100 mg/l at baseline were included. 46 patients were treated without ACEI and served as a control group, 41 patients were treated with ACEI. Participation in this study did not affect intensity in the treatment of blood glucose, blood pressure or diet. At study entry both groups were comparable with respect to duration of diabetes, diabetic complications, vascular risk factors, body mass index, medications used to treat diabetes, presence of hypertension, glycemic control, tryglycerides, HDL cholesterol, creatinine, UAC and plasma-TM. Age, blood pressure, and total cholesterol were significantly higher in the ACEI group, compared with the control group. RESULTS: After a follow up of 18 months a significant increase in UAC (delta UAC = 10.48 mg/l, p = 0.03) and plasma-TM (delta TM = 3.06 ng/l, p = 0.009) was observed in the control group, while in the ACEI treated group a decrease in albuminuria (delta UAC = -7.44 mg/l, p = 0.01) and plasma-TM (delta TM = -4.78 ng/l, p = 0.001) was seen. Despite a similar approach in hypertension and diabetes control in both groups, UAC and plasma-TM decreased after 18 months only in the ACEI treated group. Treatment with ACEI was the strongest predictor (p = 0.0001) indicating decrease of UAC and plasma-TM (multi regression analysis). CONCLUSION: Plasma-thrombomodulin might be a useful marker for assessing the efficacy of drugs potentially protecting the vessel wall. While the present study was a open, non randomized study, further investigation is necessary to proof the hypothesis in a randomized, placebo-controlled, double-blind study.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Ramipril/administração & dosagem , Trombomodulina/sangue , Adulto , Idoso , Albuminúria/sangue , Albuminúria/tratamento farmacológico , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Nefropatias Diabéticas/sangue , Monitoramento de Medicamentos , Endotélio Vascular/efeitos dos fármacos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Ramipril/efeitos adversos
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