RÉSUMÉ
Thermal or burn injury results in profound metabolic changes in the body. This can contribute to muscle atrophy, bone loss, as well as suppression of the immune system. While the mechanisms that underlie this hypermetabolic response remain unclear, patients with burn injury often have low circulating levels of vitamin D. Vitamin D has been shown to regulate bone formation as well as regulate muscle function. We sought to clarify the effects of vitamin D administration on skeletal muscle function following thermal injury using a mouse model. We found that thermal injury resulted in decreased vitamin D levels as well as decreased bone mineral density. Branched chain amino acid (BCAA)s levels were also significantly enhanced in the serum following burn injury. Vitamin D administration reversed the decrease in bone marrow-derived mesenchymal stem cell (BM-MSC)s observed post burn injury. Interestingly, vitamin D administration also resulted in increased tricarboxylic acid cycle (TCA) cycle metabolites in muscle which was decreased after burn conditions, enhanced the supply of alanine and glutamine in the blood which could contribute to gluconeogenesis and wound healing. Therefore, vitamin D supplementation after burn injury may have effects not only in bone metabolism, but may affect substrate metabolism in other organs/tissues.
RÉSUMÉ
BACKGROUND: Severe burn injury results in profound catabolic deterioration. Although burn-related catabolism has been well stated, it is unclear when the catabolic response begins. This study characterized acute changes of muscle protein breakdown at the admission and the day after in severely burned adults. METHODS: Twelve patients (43 ± 19 years old) with 40% ± 21% total body surface area burns were prospectively enrolled into an observational study approved by institutional review board. Urinary samples were collected on admission day and the day after (day 1). Patient demographic and clinical data of vital signs, blood gas and chemistry, and coagulation status were collected. Catabolic changes of muscle breakdown were quantified by urinary excretion of 3-methylhisitidine, determined by gas chromatography and mass spectrometry analysis. RESULTS: Compared with admission day, burned patients had elevated mean ± SD arterial pressure (from 90 ± 5 mm Hg to 108 ± 7 mm Hg) and heart rate (from 102 ± 7 beats per minute to 119 ± 4 beats per minute both p < 0.05) after 24 hours. Their 24-hour urinary output was 1,586 ± 813 mL at admission day to 1,911 ± 1,048 mL on day 1. The 24-hour urea excretion was elevated from 172 ± 101 mg/kg per day at admission day to 302 ± 183 mg/kg per day on day 1 (both p < 0.05), with no change in creatinine excretion. Urinary 3-methylhisitidine excretion increased from 0.75 ± 0.74 mg/kg per day at admission to 1.14 ± 0.86 mg/kg per day on day 1 (p < 0.05). The estimated skeletal muscle protein breakdown was increased from 1.1 ± 1.0 g/kg per day at admission day to 1.6 ± 1.2 g/kg per day on day 1 (p < 0.05). There were no changes in prothrombin time, activated partial thromboplastin time, or platelets. CONCLUSION: In severely burned patients, catabolic muscle protein breakdown is elevated within 24 hours after admission and before changes in coagulation. These findings suggest that early interventions may be needed to effectively attenuate the catabolic responses in burn patients. LEVEL OF EVIDENCE: Prospective and observational study, level II.
Sujet(s)
Brûlures/complications , Muscles squelettiques/anatomopathologie , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Glycémie/analyse , Protéines du sang/analyse , Brûlures/anatomopathologie , Femelle , Chromatographie gazeuse-spectrométrie de masse , Hémodynamique , Humains , Mâle , Métabolisme , Méthylhistidines/urine , Adulte d'âge moyen , Protéines du muscle/métabolisme , Muscles squelettiques/métabolisme , Études prospectives , Facteurs temps , Équilibre hydroélectrolytique , Jeune adulteRÉSUMÉ
Burn injury mediated hypermetabolic syndrome leads to increased mortality among severe burn victims, due to liver failure and muscle wasting. Metabolic changes may persist up to 2 years following the injury. Thus, understanding the underlying mechanisms of the pathology is crucially important to develop appropriate therapeutic approaches. We present detailed metabolomic and lipidomic analyses of the liver and muscle tissues in a rat model with a 30% body surface area burn injury located at the dorsal skin. Three hundred and thirty-eight of 1587 detected metabolites and lipids in the liver and 119 of 1504 in the muscle tissue exhibited statistically significant alterations. We observed excessive accumulation of triacylglycerols, decreased levels of S-adenosylmethionine, increased levels of glutamine and xenobiotics in the liver tissue. Additionally, the levels of gluconeogenesis, glycolysis, and tricarboxylic acid cycle metabolites are generally decreased in the liver. On the other hand, burn injury muscle tissue exhibits increased levels of acyl-carnitines, alpha-hydroxyisovalerate, ophthalmate, alpha-hydroxybutyrate, and decreased levels of reduced glutathione. The results of this preliminary study provide compelling observations that liver and muscle tissues undergo distinctly different changes during hypermetabolism, possibly reflecting liver-muscle crosstalk. The liver and muscle tissues might be exacerbating each other's metabolic pathologies, via excessive utilization of certain metabolites produced by each other.
Sujet(s)
Brûlures/métabolisme , Brûlures/anatomopathologie , Foie/métabolisme , Protéines du muscle/métabolisme , Muscles squelettiques/métabolisme , Animaux , Modèles animaux de maladie humaine , Rats , Rat Sprague-DawleyRÉSUMÉ
BACKGROUND: Hepatocellular carcinoma (HCC) is a malignant tumor with frequent intrahepatic metastases; extrahepatic metastases are not rare but less frequent compared to intrahepatic ones. The most frequent sites of extrahepatic metastases are the lungs, followed by the lymph nodes, bones, and adrenal glands. Case report covering gastrointestinal (GI) tract involvement from HCC is limited. CASE PRESENTATION: A 60-year-old man was referred to us in May 2019 with a diagnosis of sigmoid colon tumor. The patient had a history of HCC and had received two stages of open resections for the primary and the abdominal metastasis successively and many times of transcatheter arterial chemoembolization (TACE). The sigmoid colon tumor received Hartmann procedure after abdominal enhanced computerized tomography (CT) scan and colonoscopy, while postoperative pathology and immunohistochemistry identified it as extrahepatic colonic metastasis from HCC. CONCLUSIONS: The ratio of extrahepatic metastasis to the digestive tract was very low, and the majority was upper gastrointestinal involvement because of direct invasion or intraperitoneal implantation. TACE may be the risk factor of retrograde hematogenous metastasis to the downstream colon.
Sujet(s)
Carcinome hépatocellulaire , Chimioembolisation thérapeutique , Tumeurs du foie , Carcinome hépatocellulaire/thérapie , Côlon , Humains , Tumeurs du foie/thérapie , Mâle , Adulte d'âge moyen , PronosticRÉSUMÉ
BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a frequent metabolic disease and has been demonstrated to contribute to the severity of acute pancreatitis (AP). The present study aimed to investigate the aberrant expression of microRNA-192-5p (miR-192-5p) in AP patients with NAFLD, and further analyze the clinical significance and biological function of miR-192-5p in AP progression. METHODS: Expression of miR-192-5p was estimated using quantitative real-time PCR (qRT-PCR). Diagnostic value of miR-192-5p was evaluated by the receiver operating characteristic curve (ROC). The effects of miR-192-5p on cell proliferation, apoptosis and inflammatory response of pancreatic acinar cells were further assessed by CCK-8 assay, flow cytometry and enzyme-linked immunosorbent assay (ELISA). RESULTS: Circulating miR-192-5p was decreased in AP patients with NAFLD compared with those patients without NAFLD and healthy controls (P<0.05). The down-regulated expression of miR-192-5p had a relative high diagnostic accuracy to distinguish the AP patients with NAFLD from the cases without NAFLD. Furthermore, the overexpression of miR-192-5p in pancreatic acinar cells led to the decreased cell proliferation, increased cell apoptosis and suppressed inflammatory reaction (all P<0.05). CONCLUSION: Collectively, all data indicated that serum expression of miR-192-5p in AP patients with NAFLD is significantly decreased and serves as a candidate diagnostic biomarker. The up-regulation of miR-192-5p in pancreatic acinar cell leads to increased cell apoptosis and decreased inflammatory response, suggesting the potential of miR-192-5p as a therapeutic target of AP.
Sujet(s)
microARN/métabolisme , Stéatose hépatique non alcoolique/complications , Pancréas exocrine/métabolisme , Pancréatite/métabolisme , Adulte , Animaux , Apoptose , Études cas-témoins , Lignée cellulaire , Prolifération cellulaire , Cytokines/métabolisme , Évolution de la maladie , Femelle , Humains , Médiateurs de l'inflammation/métabolisme , Mâle , microARN/sang , microARN/génétique , Adulte d'âge moyen , Stéatose hépatique non alcoolique/diagnostic , Pancréas exocrine/anatomopathologie , Pancréatite/complications , Pancréatite/diagnostic , Pancréatite/génétique , Rats , Transduction du signalRÉSUMÉ
Beta 3 (ß3) integrin plays an important role in the initiation of myogenesis in adult muscle. Protein disulfide isomerases (PDIs) can activate ß3 integrin in various cells to promote cell migration, adhesion and fusion. However, the effect of PDIs on myogenesis during muscle regeneration has not been elucidated. Here, we report that PDIA3 expression is induced in regenerating myofibers. The inhibition of PDIA3 in muscle injuries in mice disrupts myoblast differentiation, impairs muscle regeneration, and ultimately aggravates muscle damage. Moreover, PDIA3 expression is upregulated and observed on the cell surfaces of myoblasts during differentiation and fusion. The inhibition of extracellular PDIA3 with an anti-PDIA3 monoclonal antibody attenuates ß3 integrin/AKT/mTOR signal activity, inhibits myoblast differentiation, and blocks the fusion of myoblasts. Thus, PDIA3 may be a mediator of myoblast differentiation and fusion during muscle regeneration.
Sujet(s)
Développement musculaire/physiologie , Muscles squelettiques/métabolisme , Protein Disulfide-Isomerases/métabolisme , Régénération/physiologie , Animaux , Différenciation cellulaire/physiologie , Lignée cellulaire , Intégrine bêta3/métabolisme , Mâle , Souris , Souris de lignée C57BL , Muscles squelettiques/physiologie , Myoblastes/métabolisme , Régulation positive/physiologieRÉSUMÉ
BACKGROUND: Anastomotic leak (AL), as one of the most devastating complications, is the leading cause of mortality in colorectal cancer (CRC) patients after resection. This study was aimed to investigate potential risk factors for AL in elderly surgical CRC patients. METHODS: A total of 1068 elderly subjects who underwent elective curative colorectal surgery from 2012 to 2018 were retrospectively evaluated and enrolled into this study population. The predictive value of C-reactive protein-to-albumin ratio (CAR) for AL in surgical CRC patients was evaluated by receiver operating characteristic (ROC) curve analysis. Potential risk factors for AL were assessed by the univariate and multivariate logistic regression analyses. RESULTS: Of all the 1068 enrolled patients, 81 patients have developed AL with an incidence of 7.6% (81/1068). Preoperative CAR was an effective predictor for AL with an area under the curve (AUC) of 0.758, 95% CI of 0.700-0.817, a cut-off value of 2.44, a sensitivity of 61.09% and a specificity of 80.25%, respectively (P< 0.001). Duration of operation (OR: 2.05, 95% CI: 1.21-3.44, P= 0.013) and preoperative CAR (OR: 1.94, 95% CI: 1.21-3.11, P= 0.007) were two independent risk factors for AL by the multivariate logistic regression analysis. CONCLUSIONS: Our study indicate that preoperative CAR level and duration of operation were two independent predictors for AL among elderly surgical CRC patients.
Sujet(s)
Désunion anastomotique/sang , Protéine C-réactive/métabolisme , Tumeurs colorectales/chirurgie , Sérum-albumine humaine/métabolisme , Facteurs âges , Sujet âgé , Désunion anastomotique/étiologie , Tumeurs colorectales/sang , Procédures de chirurgie digestive/effets indésirables , Procédures de chirurgie digestive/méthodes , Femelle , Humains , Mâle , Valeur prédictive des tests , Période préopératoire , Études rétrospectivesRÉSUMÉ
This study investigated changes in plasma fibrinogen metabolism and changes in coagulation in severely burned adults. Ten patients (27 ± 3 years; 91 ± 6 kg) with 51 ± 3% TBSA were consented and enrolled into an institutional review board-approved prospective study. On the study day, stable isotope infusion of 1-13C-phenylalanine and d5-phenylalanine was performed to quantify fibrinogen production and consumption. During the infusion, vital signs were recorded and blood samples were drawn every hour. Coagulation was measured by thromboelastograph (TEG). Ten normal healthy volunteers (37 ± 7 years; 74 ± 4 kg) were included as the control group. Burned adults had elevated heart rates (120 ± 2 vs 73 ± 5 [control] beats/minute), respiration rates (23 ± 2 vs 15 ± 1 breaths/minute), plasma glucose (127 ± 10 vs 89 ± 2 mg/dl), and fibrinogen levels (613 ± 35 vs 239 ± 17 mg/dl); and decreased albumin (1.3 ± 0.2 vs 3.7 ± 0.1 g/dl) and total protein (4.4 ± 0.2 vs 6.8 ± 0.1 g/dl, all P < .05). Fibrinogen breakdown was elevated in the burn group (2.3 ± 0.4 vs. 1.0 ± 0.3 µmol/kg/minute); and fibrinogen synthesis was further enhanced in the burn group (4.4 ± 0.7 vs 0.7 ± 0.2 µmol/kg/minute, both P < .05). Clotting speed (TEG-alpha) and clot strength (TEG-MA) were increased in the burn group (62 ± 4 vs 50 ± 4°, and 76 ± 2 vs 56 ± 2 mm, respectively, both P < .05). Fibrinolysis of TEG-LY60 was accelerated in the burn group (16 ± 6 vs 3 ± 1) and so was the increase in D-dimer level in the burn group (4.5 ± 0.4 vs 1.9 ± 0.3 mg/l, both P < .05). The hypercoagulable state postburn is in part a result of increased fibrinogen synthesis, over and above increased fibrinogen breakdown.
Sujet(s)
Brûlures/complications , Brûlures/métabolisme , Fibrinogène/métabolisme , Thrombophilie/étiologie , Adolescent , Adulte , Tests de coagulation sanguine , Glycémie , Études cas-témoins , Femelle , Rythme cardiaque , Humains , Acide lactique/sang , Durée du séjour , Mâle , Fréquence respiratoire , Sérumalbumine , Jeune adulteRÉSUMÉ
Mitochondrial dysfunction is associated with metabolic alterations in various disease states, including major trauma (e.g., burn injury). Metabolic derangements, including muscle insulin resistance and hyperlactatemia, are a clinically significant complication of major trauma. Coenzyme Q10 (CoQ10) is an essential cofactor for mitochondrial electron transport, and its reduced form acts as a lipophilic antioxidant. Here, we report that burn injury induces impaired muscle insulin signaling, hyperlactatemia, mitochondrial dysfunction (as indicated by suppressed mitochondrial oxygen consumption rates), morphological alterations of the mitochondria (e. g., enlargement, and loss of cristae structure), mitochondrial oxidative stress, and disruption of mitochondrial integrity (as reflected by increased mitochondrial DNA levels in the cytosol and circulation). All of these alterations were significantly alleviated by CoQ10 treatment compared with vehicle alone. These findings indicate that CoQ10 treatment is efficacious in protecting against mitochondrial dysfunction and insulin resistance in skeletal muscle of burned mice. Our data highlight CoQ10 as a potential new strategy to prevent mitochondrial damage and metabolic dysfunction in burn patients.
Sujet(s)
Brûlures/métabolisme , Insuline/métabolisme , Mitochondries/métabolisme , Muscles squelettiques/métabolisme , Transduction du signal , Ubiquinones/analogues et dérivés , Animaux , Mâle , Souris , Ubiquinones/métabolismeRÉSUMÉ
Long noncoding RNAs (lncRNAs) have important functions in tumor development and progression, including colorectal cancer (CRC), but their roles are not completely understood. In this study, the roles of the lncRNA transmembrane phosphoinositide 3-phosphatase and tensin homolog 2 pseudogene 1 (TPTE2P1), previously implicated in gallbladder cancer cell migration and invasion, were evaluated in CRC. In particular, quantitative polymerase chain reaction was used to quantify TPTE2P1 levels in tumor tissues and cell lines. The association between TPTE2P1 and survival was analyzed using the online tool OncoLnc. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, colony formation assays, and flow cytometry were used to evaluate the effects of TPTE2P1 on viability, cell cycle progression, and apoptosis. Signaling pathway proteins were quantitated by Western blot analysis. Finally, the role of TPTE2P1 was analyzed in vivo using mouse models. TPTE2P1 levels were significantly higher in CRC tissues than in adjacent normal tissues. Higher expression was associated with a poor survival rate. The silencing of TPTE2P1 led to cell cycle arrest at the S phase and thereby inhibited cell viability. TPTE2P1 knockdown also caused cancer cell apoptosis via the activation of the apoptosis regulator (BCL2)/caspase 3 signaling cascade. In addition, the inhibition of TPTE2P1 had suppressive effects on tumors in vivo. TPTE2P1 is upregulated in CRC and plays essential roles in the regulation of cell viability in vitro and tumor formation in vivo.
Sujet(s)
Prolifération cellulaire/génétique , Survie cellulaire/génétique , Tumeurs colorectales/génétique , ARN long non codant/génétique , Animaux , Apoptose/génétique , Caspase-3/génétique , Points de contrôle du cycle cellulaire/génétique , Lignée cellulaire tumorale , Mouvement cellulaire/génétique , Tumeurs colorectales/anatomopathologie , Régulation de l'expression des gènes tumoraux/génétique , Hétérogreffes , Humains , Souris , Protéines proto-oncogènes c-bcl-2/génétique , Transduction du signal/génétiqueRÉSUMÉ
RATIONALE: Pyoderma gangrenosum (PG) is a rare postoperative complication of enterostomy, mostly developing from dermatitis, which may have serious consequence. PATIENT CONCERNS: A patient with lower rectal cancer receiving low anterior resection (LAR) and protective ileostomy was initially diagnosed with dermatitis, which very quickly developed to PG, though no medical or familial history was found. DIAGNOSIS: We diagnosed the patient with peristoaml dermatitis starting from a tiny skin ulceration, but corrected the diagnosis to PG because of the rapid development and severe consequences. INTERVENTIONS: Routine stoma care did not improve the condition, so we performed 2 terms of debridement, the closure of the stoma and autologous skin transplantation before finally solving the problem. OUTCOMES: The patient was discharged 60 days after the first surgery and 5 days after the last one. After 18 months of follow-up, the patient kept in a stable condition. LESSONS: Medical staff should not neglect peristoaml dermatitis because of its common occurrence. Once the situation develops beyond the doctors' expectation, more efforts should be made to treat it, even expand debridement if possible.
Sujet(s)
Débridement/méthodes , Iléostomie/effets indésirables , Pyodermie phadégénique/thérapie , Transplantation de peau/méthodes , Antibactériens/usage thérapeutique , Humains , Mâle , Mezlocilline/usage thérapeutique , Adulte d'âge moyen , Transplantation autologue , Oxyde de zinc/administration et posologie , Oxyde de zinc/usage thérapeutiqueRÉSUMÉ
Cell-free DNA (cf-DNA) concentration in human plasma is often increased after burn and trauma injuries. Two major sources of cf-DNA are the parenchymal cells damaged by the injury and various circulating cells indirectly altered by the response to injury. The cf-DNA originating from neutrophils, also known as circulating neutrophil extracellular traps (cNETs), is of notable interest because cNETs have been associated with pathological processes in other conditions, including cancer, autoimmunity, etc. Both intact chromatin and oligonucleotides, which are the by-product of cf-DNA degradation, are assumed to contribute to the cf-DNA in patients. However, traditional assays for cf-DNA quantification do not distinguish between cNETs and cf-DNA of other origins and do not differentiate between intact chromatin and oligonucleotides. Here we measure the amount of intact cNETs in the circulation, using a microfluidic device that mechanically traps chromatin fibers directly from blood and an immunofluorescence protocol that detects neutrophil-specific proteins associated with chromatin. In a rat model of burn injury, we determined that the chromatin fibers in the circulation after injury originate exclusively from neutrophils and are cNETs. We found that the concentration of cNETs surges the first day after injury and then decreases slowly over several days. In a secondary sepsis model, which involved a burn injury followed by cecal-ligation-puncture, we measured additional increases in cNETs in the days after sepsis was induced. These results validate a microfluidic assay for the quantification of cNETs and will facilitate fruther studies probing the contribution of cNETs to complications after burns and sepsis.
Sujet(s)
Brûlures/sang , Pièges extracellulaires , Microfluidique/méthodes , Sepsie/sang , Animaux , Leukocyte elastase/sang , Mâle , Rats , Rat Wistar , Reproductibilité des résultatsRÉSUMÉ
BACKGROUND: It has been established that glucagon-like peptide 1 (GLP 1) inhibits pancreatic ß-cell apoptosis, increases insulin secretion, and improves glucose tolerance in scald injury. However, the effects of Exendin-4, a long-acting incretin similar to GLP 1, remained unclear in severe scald injury. Hence, this study attempted to investigate whether Exendin-4 had similar effects by protecting the histology of pancreas in severely scalded rats. METHODS: One hundred sixty-two adult Wistar rats were equally randomized to sham burn group, burn group and burn with Exendin-4 treatment group. Rats were subjected to full skin thickness scald injuries (total body surface area: 50%) and were injected subcutaneously with Exendin-4 (4 µg/kg) twice daily. The histological changes of islets, the apoptosis of ß cells, the amount of glucagon and insulin, and the concentration of plasma glucagon and insulin were observed; and the intraperitoneal glucose tolerance test was performed as well. RESULTS: The islets and ß cells were injured and the number of secretory granules decreased in the scalded rats, but less histopathological changes were seen in the rats treated with Exendin-4. The apoptosis index of treated rats was significantly lower than that of the scalded rats (p < 0.05). There was significant difference in ß-cell density postinjury between the two groups (p < 0.05). More insulin and less glucagon in islets and plasma were found in the treated rats (p < 0.05), suggesting improved intraperitoneal glucose tolerance (p < 0.05) and fasting blood glucose (p < 0.05) in this group. CONCLUSION: Based on our previous finding that GLP-1 could control hyperglycemia by increasing insulin secretion and inhibiting ß-cell apoptosis in severe scald injuries, this study further confirmed that Exendin-4 could increase glycemic control following severe scald by preserving the histology of ß cells in pancreatic islets and inhibiting their apoptosis.
Sujet(s)
Brûlures/complications , Exénatide/usage thérapeutique , Hyperglycémie/traitement médicamenteux , Ilots pancréatiques/effets des médicaments et des substances chimiques , Animaux , Glucagon/sang , Hyperglycémie provoquée , Hyperglycémie/étiologie , Insuline/sang , Ilots pancréatiques/physiologie , Rats , Rat WistarRÉSUMÉ
BACKGROUND: We used the 15 N glycine urinary end-product enrichment technique to quantify whole body protein turnover following thoracic surgery. MATERIALS AND METHODS: A single dose of 15 N glycine (2 mg/kg) was administered orally on postoperative day 1 to children (1-18 years) following thoracic surgery. 15 N enrichment of ammonia and urea was measured in mixed urine after 12 and 24 hours, respectively, and protein synthesis, breakdown, and net balance determined. Nitrogen balance (dietary intake minus urinary excretion) was calculated. Urinary 3-methylhistidine:creatinine ratio was measured as a marker of skeletal muscle protein breakdown. RESULTS: We enrolled 19 subjects-median (interquartile range): age, 13.8 years (12.2-15.1); weight, 49.2 kg (38.4-60.8)-who underwent thoracotomy (n = 12) or thoracoscopic (n = 7) surgery. Protein synthesis and breakdown by 15 N enrichment were 7.1 (5.5-9) and 7.1 (5.6-9) g·kg-1 ·d-1 with ammonia (12 hours) as the end product, and 5.8 (3.8-6.7) and 6.7 (4.5-7.6) with urea (24 hours), respectively. Net protein balance by the 15 N glycine and urinary urea nitrogen methods were -0.34 (-0.47, -0.3) and -0.48 (-0.65, -0.28) g·kg-1 ·d-1 , respectively (rs = 0.828, P < .001). Postoperative change in 3-methylhistidine:creatinine ratio did not correlate significantly with protein breakdown or balance. CONCLUSION: The single-dose oral administration of 15 N glycine stable isotope with measurement of urinary end-product enrichment is a feasible and noninvasive method to investigate whole body protein turnover in children. After major surgery, children manifest increased protein turnover and net negative balance due to increased protein breakdown.
Sujet(s)
Créatinine/urine , Glycine/administration et posologie , Méthylhistidines/urine , Complications postopératoires/urine , Protéines/métabolisme , Procédures de chirurgie thoracique/effets indésirables , Adolescent , Ammoniac/urine , Marqueurs biologiques/urine , Enfant , Enfant d'âge préscolaire , Femelle , Humains , Nourrisson , Mâle , Isotopes de l'azote/administration et posologie , Projets pilotes , Reproductibilité des résultats , Urée/urineRÉSUMÉ
Secondary burn necrosis is the expansion and deepening of the original burn injury several days after injury. Limiting the extent of secondary burn necrosis may improve outcomes. In this study, we examined the ability of the lipid mediator of inflammation-resolution resolvin D2 (RvD2) and chromatin-lysing enzyme (DNase) to reduce secondary burn necrosis. Male Wistar rats were injured using a brass comb with 4 prongs heated in boiling water. This method created 2 parallel rows of 4 rectangular burned areas separated by 3 unburned interspaces. Starting at 2 hours after the burn injury, rats received either 25 ng/kg RvD2 intravenously daily for 7 days or 200 U/kg DNase every 12 hours for 3 days. We documented the necrosis around the initial wounds by digital photography. We used laser Doppler to assess the total blood flux in the burn area. We evaluated the functionality of the capillary network in the interspaces by optical coherence tomography angiography. We performed histological examination of wound skin tissue samples collected at 14 days postburn. We found that the interspace areas were preserved and had higher blood flow in the RvD2-treated group, while the burn areas expanded into the interspace areas, which were confluent by 7 days postburn, in the control-untreated group. We found a larger monocyte-to-neutrophil ratio in the RvD2-treated group compared with the DNase-treated and control groups (P < .05). Overall, RvD2 suppresses secondary necrosis and starts regeneration, highlighting the role of inflammation resolution as a potential therapeutic target in burn care.
Sujet(s)
Brûlures/traitement médicamenteux , Brûlures/anatomopathologie , Désoxyribonucléases/pharmacologie , Acide docosahexaénoïque/pharmacologie , Animaux , Brûlures/imagerie diagnostique , Modèles animaux de maladie humaine , Mâle , Nécrose , Rats , Rat Wistar , Peau/vascularisation , Peau/effets des médicaments et des substances chimiquesRÉSUMÉ
Metabolic derangements are a clinically significant complication of major trauma (e.g., burn injury) and include various aspects of metabolism, such as insulin resistance, muscle wasting, mitochondrial dysfunction and hyperlactatemia. Nonetheless, the molecular pathogenesis and the relation between these diverse metabolic alterations are poorly understood. We have previously shown that burn increases farnesyltransferase (FTase) expression and protein farnesylation and that FTase inhibitor (FTI) prevents burn-induced hyperlactatemia, insulin resistance, and increased proteolysis in mouse skeletal muscle. In this study, we found that burn injury activated mTORC1 and hypoxia-inducible factor (HIF)-1α, which paralleled dysfunction, morphological alterations (i.e., enlargement, partial loss of cristae structure) and impairment of respiratory supercomplex assembly of the mitochondria, and ER stress. FTI reversed or ameliorated all of these alterations in burned mice. These findings indicate that these burn-induced changes, which encompass various aspects of metabolism, may be linked to one another and require protein farnesylation. Our results provide evidence of involvement of the mTORC1-HIF-1α pathway in burn-induced metabolic derangements. Our study identifies protein farnesylation as a potential hub of the signaling network affecting multiple aspects of metabolic alterations after burn injury and as a novel potential molecular target to improve the clinical outcome of severely burned patients.
Sujet(s)
Brûlures/anatomopathologie , Sous-unité alpha du facteur-1 induit par l'hypoxie/métabolisme , Complexe-1 cible mécanistique de la rapamycine/métabolisme , Mitochondries/métabolisme , Muscles/anatomopathologie , Prénylation des protéines , Animaux , Modèles animaux de maladie humaine , Complexe enzymatique de la chaine respiratoire mitochondriale/métabolisme , Stress du réticulum endoplasmique , Voies et réseaux métaboliques , Souris de lignée C57BL , Multimérisation de protéinesRÉSUMÉ
Essential genes are required for the viability of an organism. Accurate and rapid identification of new essential genes is of substantial theoretical interest to synthetic biology and has practical applications in biomedicine. Fractals provide facilitated access to genetic structure analysis on a different scale. In this study, machine learning-based methods using solely fractal features are presented and the problem of predicting essential genes in bacterial genomes is evaluated. Six fractal features were investigated to learn the parameters of five supervised classification methods for the binary classification task. The optimal parameters of these classifiers are determined via grid-based searching technique. All the currently available identified genes from the database of essential genes were utilized to build the classifiers. The fractal features were proven to be more robust and powerful in the prediction performance. In a statistical sense, the ELM method shows superiority in predicting the essential genes. Non-parameter tests of the average AUC and ACC showed that the fractal feature is much better than other five compared features sets. Our approach is promising and convenient to identify new bacterial essential genes.
Sujet(s)
Fractales , Gènes essentiels , Apprentissage machine , Bactéries/génétique , Bases de données d'acides nucléiques , Gènes bactériens , Génomique/méthodes , Humains , Dynamique non linéaire , Courbe ROCRÉSUMÉ
BACKGROUND Tectonic family member 1 (TCTN1), a member of the tectonic family, is involved in several developmental processes and is aberrantly expressed in multiple solid tumors. However, the expression and regulation of TCTN1 in human colorectal cancer (CRC) is still not clear. MATERIAL AND METHODS The expression of TCTN1 mRNA was first explored by using Oncomine microarray datasets. TCTN1 expression was silenced in human CRC cell lines HCT116 and SW1116 via RNA interference (RNAi). Furthermore, we investigated the effect of TCTN1 depletion on CRC cell growth by MTT, colony formation, and flow cytometry in vitro. RESULTS In this study, meta-analysis showed that the expressions of TCTN1 mRNA in CRC specimens were significantly higher than that in normal specimens. Knockdown of TCTN1 expression potently inhibited the abilities of cell proliferation and colony formation as determined. Flow cytometry analysis showed that depletion of TCTN1 could cause cell cycle arrest at the G2/M phase. In addition, Annexin V/7-AAD double-staining indicated that TCTN1 silencing promoted cell apoptosis through down-regulation of caspase 3 and Bcl-2 and upregulation of cleaved caspase 3 and PARP. CONCLUSIONS Our results indicate that TCTN1 may be crucial for CRC cell growth, providing a novel alternative to target therapies of CRC. Further research on this topic is warranted.
Sujet(s)
Tumeurs colorectales/génétique , Tumeurs colorectales/anatomopathologie , Protéines membranaires/déficit , Protéines membranaires/génétique , Apoptose/génétique , Caspase-3/métabolisme , Cycle cellulaire/génétique , Points de contrôle du cycle cellulaire/génétique , Prolifération cellulaire/génétique , Tumeurs colorectales/métabolisme , Régulation de l'expression des gènes tumoraux , Techniques de knock-down de gènes/méthodes , Cellules HCT116 , Cellules HEK293 , Humains , Protéines membranaires/métabolisme , ARN messager/biosynthèse , ARN messager/génétique , Petit ARN interférent/administration et posologie , Petit ARN interférent/génétique , TransfectionRÉSUMÉ
Inflammation and apoptosis develop in skeletal muscle after major trauma, including burn injury, and play a pivotal role in insulin resistance and muscle wasting. We and others have shown that inducible nitric oxide synthase (iNOS), a major mediator of inflammation, plays an important role in stress (e.g., burn)-induced insulin resistance. However, it remains to be determined how iNOS induces insulin resistance. Moreover, the interrelation between inflammatory response and apoptosis is poorly understood, although they often develop simultaneously. Nuclear factor (NF)-κB and p53 are key regulators of inflammation and apoptosis, respectively. Sirt1 inhibits p65 NF-κB and p53 by deacetylating these transcription factors. Recently, we have shown that iNOS induces S-nitrosylation of Sirt1, which inactivates Sirt1 and thereby increases acetylation and activity of p65 NF-κB and p53 in various cell types, including skeletal muscle cells. Here, we show that iNOS enhances burn-induced inflammatory response and apoptotic change in mouse skeletal muscle along with S-nitrosylation of Sirt1. Burn injury induced robust expression of iNOS in skeletal muscle and gene disruption of iNOS significantly inhibited burn-induced increases in inflammatory gene expression and apoptotic change. In parallel, burn increased Sirt1 S-nitrosylation and acetylation and DNA-binding capacity of p65 NF-κB and p53, all of which were reversed or ameliorated by iNOS deficiency. These results indicate that iNOS functions not only as a downstream effector but also as an upstream enhancer of burn-induced inflammatory response, at least in part, by Sirt1 S-nitrosylation-dependent activation (acetylation) of p65 NF-κB. Our data suggest that Sirt1 S-nitrosylation may play a role in iNOS-mediated enhanced inflammatory response and apoptotic change, which, in turn, contribute to muscle wasting and supposedly to insulin resistance after burn injury.
Sujet(s)
Apoptose/physiologie , Brûlures/anatomopathologie , Inflammation/anatomopathologie , Muscles squelettiques/anatomopathologie , Nitric oxide synthase type II/métabolisme , Sirtuine-1/métabolisme , Facteur de transcription RelA/métabolisme , Protéine p53 suppresseur de tumeur/métabolisme , Acétylation , Animaux , Protéines de liaison à l'ADN/métabolisme , Activation enzymatique , Souris , Souris de lignée C57BL , Souris knockout , Nitric oxide synthase type II/génétiqueRÉSUMÉ
OBJECTIVES: Innate immune dysfunction after major burn injuries increases the susceptibility to organ failure. Lipid mediators of inflammation resolution, e.g., resolvin D2, have been shown recently to restore neutrophil functionality and reduce mortality rate in a rat model of major burn injury. However, the physiological mechanisms responsible for the benefic activity of resolvin D2 are not well understood. DESIGN: Prospective randomized animal investigation. SETTING: Academic research setting. SUBJECTS: Wistar male rats. INTERVENTIONS: Animals were subjected to a full-thickness burn of 30% total body surface area. Two hours after burn, 25 ng/kg resolvin D2 was administered IV and repeated every day, for 8 days. At day 10 post burn, 2 mg/kg of lipopolysaccharide was administered IV, and the presence of renal and hepatic injuries was evaluated at day 11 post burn by histology, immunohistochemistry, and relevant blood chemistry. MEASUREMENTS AND MAIN RESULTS: In untreated animals, we found significant tissue damage in the kidneys and liver, consistent with acute tubular necrosis and multifocal necrosis, and changes in blood chemistry, reflecting the deterioration of renal and hepatic functions. We detected less tissue damage and significantly lower values of blood urea nitrogen (26.4 ± 2.1 vs 36.0 ± 9.3 mg/dL; p ≤ 0.001), alanine aminotransferase (266.5 ± 295.2 vs 861.8 ± 813.7 U/L; p ≤ 0.01), and total bilirubin (0.13 ± 0.05 vs 0.30 ± 0.14 mg/dL; p ≤ 0.01) in resolvin D2-treated rats than in untreated animals. The mean blood pressure of all animals was above 65 mm Hg, indicating adequate tissue perfusion throughout the experiments. We measured significantly larger amounts of chromatin in the circulation of untreated than of resolvin D2-treated rats (575.1 ± 331.0 vs 264.1 ± 122.4 ng/mL; p ≤ 0.05) and identified neutrophil extracellular traps in kidney and liver tissues from untreated rats, consistent with the tissue damage. CONCLUSIONS: Pathologic changes in kidney and liver tissues in a rat model of major burn and endotoxin insults are ameliorated by resolvin D2.