Based on the biological significance of the ubiquitin-proteasome pathway (UPP) and its potential role during sepsis, burns and ischemia-reperfusion injury, we hypothesized that the systemic response to traumatic shock (TS) is accompanied by tissue-specific UPP alterations. Therefore, we studied tissue ubiquitin pools, chymotryptic- and tryptic-like proteasome peptidase activities and ubiquitin-protein ligation (UbPL) rates in skeletal muscle, heart, lung, liver, spleen and kidney using a clinically relevant porcine model (bilateral femur fracture/hemorrhage followed by fluid resuscitation). TS induced a systemic reduction of tissue- specific high molecular mass ubiquitin-protein conjugates (>50 kDa). Free ubiquitin was unaffected. The dynamic organ patterns of ubiquitin pools paralleled the typical physiological response to TS and resuscitation. Reduction of ubiquitin-protein conjugates was most pronounced in heart and lung (p<0.05 vs. control) and accompanied by significant increases in proteasome peptidase and UbPL activities in these organs. Unlike all other tissues, spleen proteasome peptidase and UbPL activities were significantly reduced 10 h after TS. These findings support the concept that the UPP could play an important role in regulation of cell functions during the early whole-body response to TS. The UPP might be a therapeutic target to improve the metabolic care after TS, particularly in the heart, lung, and spleen., M. B. Patel, S. A. Earle, M. Majetschak., and Obsahuje bibliografii a bibliografické odkazy
Huntington’s disease (HD) is a demential, neurodegenerative inheritable disease affecting middle-aged patients. HD is characterized by uncontrolled choreiform movements, psychiatric symptoms and cognitive decline. Histopathological changes in HD brains reveal a considerable damage to basal ganglia, particularly affecting middle-sized spiny neurons from the caudate-putamen region. Neurochemical changes are specifically oriented to deplete GABAergic and cholinergic systems, while molecular alterations include an increased expression of CAG trinucleotide at exon 1 from the huntingtin (htt) gene, as well as aggregation of mutant htt. Although several hypotheses regarding the mechanisms by which neurotoxicity is triggered in HD brains have been suggested on the basis of experimental evidence, so far it remains not clear which of them are predominant or whether they are complementary. Recent experimental evidence through transgenic mice models reveal an interesting inter action between expanded CAG triplets, mutant htt, and the increase in toxic metabolites from the kynurenine pathway. Further evidence supports the assumption that different toxic mechanisms (i.e. excitotoxicity, energy metabolism impairment, inflammatory events, oxidative stress, etc.) are confluent and depend on each other. In this review we will briefly summarize some of those findings and propose a final integrative hypothesis for HD., V. Pérez-de la Cruz, A. Santamaría., and Obsahuje bibliografii a bibliografické odkazy
Leptin is a hormone that regulates food intake. During inflammatory status, leptin may contribute to the anorexia and cachexia of infection. Pulmonary endarterectomy was used as a model of non-infectious cytokine network hyperstimulation. Leptin and soluble leptin receptor (SLR) were compared with evolution of cortisol and inflammatory cytokines in twenty-two patients with chronic thromboembolic pulmonary hypertension treated with pulmonary endarterectomy using cardiopulmonary bypass (CBP) and deep hypothermic circulatory arrest (DHCA). Leptin, SLR, cortisol, IL-1β, IL-6, IL-8, and TNFα concentrations in arterial blood were measured before/after sternotomy, last DHCA, separation from bypass, 12, 18, 24, 36, and 48 h after sternotomy. Mean duration of CPB was 338.2 min.; mean circulatory arrest time 39.9 min. The initial decline of leptin, SLR, TNFα, IL-6, and IL-8 was followed by an increase culminating 6-24 h after sternotomy. Leptin peak levels were detected 24 h after sternotomy (28.0 ng/ml, 21.9-37.6). IL-6 culminated after separation from CPB, IL-8 was highest 12 h after sternotomy. Leptin concentrations correlated with IL-6 (r=0.82), and TNFα (r=0.73). Large cardiovascular surgery caused a significant increase in serum leptin, indicating its acute regulation by stress factors. This effect may be secondary to the inflammatory response mediated via cytokine stimulation. Correlation between leptin and IL-6 indicates the role of IL-6 in leptin induction., P. Maruna, J. Lindner, K. M. Kubzová., and Obsahuje seznam literatury