U POCD nedávné výsledky výzkumu poukazují na hlavní úlohu neurozánětlivé kaskády, přičemž endoteliální dysfunkce může poškození zhoršovat. Klíčovými oblastmi budoucího translačního výzkumu jsou zkoumání genomických a molekulárních mechanismů, které jsou příčinou rozdílů mezi jednotlivci v zánětlivé odpovědi na operaci, zlepšení identifikace vhodných endoteliálních a zánětlivých biomarkerů a vývoj strategií modulujících endotel a protizánětlivých strategií (prevence a odeznění). Je to důležité, protože mezi pacienty podstupujícími operace je stále více seniorů, kteří vykazují zvýšenou náchylnost k POCD a k dalším perioperačním chorobným syndromům.
- Keywords
- endoteliální dysfunkce, neurozánět,
- MeSH
- Anesthesia * adverse effects MeSH
- Surgical Procedures, Operative adverse effects MeSH
- Endothelial Cells pathology secretion MeSH
- Blood-Brain Barrier growth & development drug effects MeSH
- Hyperemia classification MeSH
- Cognition Disorders * physiopathology prevention & control MeSH
- Humans MeSH
- Mice MeSH
- Postoperative Cognitive Complications MeSH
- Aged, 80 and over * MeSH
- Aged * MeSH
- Tumor Necrosis Factor-alpha antagonists & inhibitors administration & dosage therapeutic use MeSH
- Inflammation complications physiopathology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Aged, 80 and over * MeSH
- Aged * MeSH
- Animals MeSH
- Publication type
- Review MeSH
Within human pulmonary artery, neurotrophin growth factors [NTs; e.g. brain-derived neurotrophic factor (BDNF)] and their high-affinity receptors (tropomyosin-related kinase; Trk) and low-affinity receptors p75 neurotrophin receptor (p75NTR) have been reported, but their functional role is incompletely understood. We tested the hypothesis that BDNF is produced by human pulmonary artery endothelial cells (PAECs). In the context of hypoxia as a risk factor for pulmonary hypertension, we examined the effect of hypoxia on BDNF secretion and consequent autocrine effects on pulmonary endothelium. Initial ELISA analysis of circulating BDNF in 30 healthy human volunteers showed that 72 h exposure to high altitude (~11,000 ft, alveolar PO2 = 100 mmHg) results in higher BDNF compared to samples taken at sea level. Separately, in human PAECs exposed for 24h to normoxia vs. hypoxia (1-3% O2), ELISA of extracellular media showed increased BDNF levels. Furthermore, quantitative PCR of PAECs showed 3-fold enhancement of BDNF gene transcription with hypoxia. In PAECs, BDNF induced NO production (measured using an NO-sensitive fluorescent dye DAF2-DA) that was significantly higher under hypoxic conditions, an effect also noted with the TrkB agonist 7,8-DHF. Importantly, hypoxia-induced NO was blunted by neutralization of secreted BDNF using the chimeric TrkB-Fc. Both hypoxia and BDNF increased iNOS (but not eNOS) mRNA expression. In accordance, BDNF enhancement of NO in hypoxia was not blunted by 50 nM L-NAME (eNOS inhibition) but substantially lower with 100 μM L-NAME (eNOS and iNOS inhibition). Hypoxia and BDNF also induced expression of hypoxia inducible factor 1 alpha (HIF-1α), a subunit of the transcription factor HIF-1, and pharmacological inhibition of HIF-1 diminished hypoxia effects on BDNF expression and secretion, and NO production. These results indicate that human PAECs express and secrete BDNF in response to hypoxia via a HIF-1-regulated pathway.
- MeSH
- Arginase metabolism MeSH
- Pulmonary Artery pathology MeSH
- Endothelium, Vascular pathology MeSH
- Endothelial Cells metabolism secretion MeSH
- Gene Expression MeSH
- Hypoxia-Inducible Factor 1 metabolism MeSH
- Cell Hypoxia MeSH
- Hypoxia blood MeSH
- Cells, Cultured MeSH
- Humans MeSH
- RNA, Messenger genetics metabolism MeSH
- Brain-Derived Neurotrophic Factor blood genetics secretion MeSH
- Nitric Oxide metabolism MeSH
- Protein Kinases metabolism MeSH
- Signal Transduction MeSH
- Nitric Oxide Synthase Type II metabolism MeSH
- Nitric Oxide Synthase Type III metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
Z mnoha teorií multifaktoriálního procesu stárnutí patří k nejdůležitějším i volně radikálová teorie. Vysvětluje etiologii a patogenezu některých chorob a poruch během stárnutí. Volné radikály poškozují lipidy, proteiny, glycidy a DNA. Ve stáří klesá antioxidační obrana tvořená zvláště redukovaným glutationem, glutationperoxidázou, katalázou, karotenoidy, estrogeny. Mg, Se, Zn a podobně se snižuje i schopnost opravovat poškozené biomolekuly. Naopak stoupá intracelulární vápník, oxidované nebo modifikované LDL, produkty lipoperoxidace, aldehydy, oxidované proteiny, homocystein a ferritin. Volné radikály se podílejí na vzniku a průběhu mnoha onemocnění, jako jsou např. diabetes mellitus, zhoubné nádory, ateroskleróza, katarakta, makulární degenerace, choroby kůže, zubů, uší, degenerativní choroby mozku - Alzheimerova a Parkinsonova choroba, amyotrofická laterální skleróza, roztroušená skleróza, ale i na revmatoidní artritída a další. Volné radikály mohou mít vliv i na osteoporózu a snižují také imunitu. Ještě není dostatečně prokázáno, zda antioxidanty prodlužují život, ale určité chrání před předčasnou smrtí. Budoucí výzkum různých směsí antioxidantů a jejich preventivní používání pravděpodobně přispěje i k prodloužení života.
There are many theories of the multifactorial processes of aging. One of the most important represents the free radical theory. It explains at least several diseases and disturbances during aging. Free radicals destroy lipids, proteins, sacharides and DNA. Antioxidant defence decreases with age, especially are reduced glutathion, glutathion peroxidase, catalase, carotenoids, estrogens, Mg, Se, Zn and others, as well as the abiUty to repair the injured biomolecules. On the other hand there is increasing of intracellular calcium, oxidized or modified LDL, products of lipoperoxidation, aldehydes, oxidised proteins, homocystein, ferritin. Free radicals take part in the etiology and pathogenesis in many diseases, especially in diabetes mellitus, malignant tumors, atherosclerosis, cataract, macular degeneration, in the diseases of skin, teeth, ears, in degenerative diseases of brain like Alzheimer's and Parkinson's diseases, amyotrophical lateral sclerosis, sclerosis multiplex, in rheumatoid arthritis and the others. Free radicals may take part also in the pathogeny of osteoporosis, they also decrease immunity. It is not yet satisfactory demonstrated, that antioxidants prolong the live, but they protect against premature death. The future research of different mixtures of antioxidants and their preventive use may lead also to the extension of the life span.
- MeSH
- Calcium-Transporting ATPases deficiency MeSH
- Endothelial Cells metabolism secretion MeSH
- Humans MeSH
- Mitochondria genetics metabolism MeSH
- Central Nervous System Diseases physiopathology MeSH
- Lipid Peroxidation genetics MeSH
- DNA Damage MeSH
- Aging physiology metabolism MeSH
- Superoxide Dismutase physiology MeSH
- Free Radicals antagonists & inhibitors adverse effects MeSH
- Check Tag
- Humans MeSH