Hartowanie przez niedokrwienie u szczurów z adiuwantowym zapaleniem stawów

Background: Adjuvant-induced arthritis (AIA) in rats is a model of chronic systemic inflammation and a model of rheumatoidarthritis in humans.Aim: To investigate effectiveness of ischaemic preconditioning (IPC) in reducing the area of myocardial infarction in rats with AIA.Methods: The study was performed in vivo in male SPRD/Mol/Lod rats. Animals were assigned to the experimental group (n = 15) or the control group (n = 14). In the experimental group, AIA was induced by subcutaneous administration of 1 mLof Freund’s complete adjuvant, and the experiment was performed after 14 days. In control (healthy) animals, no procedures were performed prior to the proper experiment. Animals were anaesthesized (by intraperitoneal administration of ketamineand xylazine) and put on a ventilator. Then, myocardial infarction was induced, preceded by IPC in some animals. To induceinfarction, left main coronary artery (LMCA) was occluded for 30 min, followed by 60 min of reperfusion. IPC protocol consisted of LMCA occlusion for 3 min, followed by 5 min of reperfusion and a second LMCA occlusion for 7 min. Weevaluated a percentage ratio of the infarct size to the risk area (IS/RA). Necrosis area was stained with tetrazolium, and thearea supplied by LMCA was determined using Evans blue. All areas were determined by planimetry. We used nonparametric Kruskal-Wallis rank ANOVA with multiple comparisons, and the results were shown as median values and 25th and 75th percentiles. P < 0.05 was considered statistically significant.Results: In the control group with IPC (n = 7), the IS/RA ratio of 25% (23–38) was significantly reduced compared to thecontrol group without IPC (n = 7) (58% [57–63], p < 0.05). In the AIA group with IPC (n = 7), the IS/RA ratio of 58% (51–65)did not differ significantly compared to the AIA group without IPC (n = 8) (65% [62–71]).Conclusions: Our findings indicate that IPC in rats with AIA does not result in a significant reduction of myocardial necrosisarea induced by 30 min of ischaemia and 60 min of reperfusion. This effect might have been related to the presence ofchronic systemic inflammation. Absent or reduced benefits of IPC may be one reason for an increased cardiovascular risk inpatients with rheumatoid arthritis.Wstęp: Adiuwantowe zapalenie stawów (AIA) u szczurów jest modelem przewlekłego ogólnoustrojowego zapalenia i jednocześnie modelem ludzkiego reumatoidalnego zapalenia stawów.Cel: Celem niniejszej pracy było zbadanie skuteczności hartowania przez niedokrwienie (IPC) w redukcji obszaru zawałuu szczurów z AIA.Metody: Badania przeprowadzono in vivo na szczurach SPRD/Mol/Lod (samce). Zwierzęta przydzielono do jednej z grup: doświadczalnej (n = 15) lub kontrolnej (n = 14). U zwierząt z grupy D wywoływano AIA, podając podskórnie 1 ml kompletnego adiuwantu Freunda. Doświadczenia przeprowadzano w 14. dniu trwania choroby. U zwierząt kontrolnych (zdrowych) nie stosowano przed właściwym doświadczeniem żadnych procedur. Zwierzęta znieczulano (ketamina i ksylazyna podawane dootrzewnowo) i podłączano do respiratora. Następnie wywoływano zawał serca, u części przed zawałem stosowano IPC. W celu wywołania zawału na 30 min zamykano lewą tętnicę wieńcową (LMCA), po tym czasie następowała 60-minutowa reperfuzja. W celu zahartowania miokardium zamykano LMCA 2-krotnie: pierwszy raz na 3 min, drugi na 7 min, epizody te oddzielała 5-minutowa reperfuzja. Oceniano stosunek powierzchni objętej zawałem (IS) do całego obszaru unaczynionego przez LMCA (RA); wynik wyrażano w procentach. Do wyróżnienia zakresu martwicy posługiwano się metodą barwienia tetrazolium. Obszar unaczynienia LMCA oznaczano błękitem Evansa. Poszczególne obszary obliczano metodą planimetryczną. Użyto nieparametrycznego testu ANOVA rang Kruskala-Wallisa z wielokrotnymi porównaniami. Wyniki podano jako mediany oraz 25. i 75. centyle. Za poziom istotności statystycznej przyjęto p < 0,05.Wyniki: W grupie kontrolnej, gdy przed zawałem stosowano IPC (n = 7) IS/RA wyniósł 25% (23–28) i był istotnie mniejszy(p < 0,05) niż u zwierząt bez poprzedzającego hartowania (n = 7) — 58% (57–63). U zwierząt z AIA, gdy stosowano IPC (n = 7) IS/RA wyniósł 58% (51–65) i nie różnił się istotnie od wyniku uzyskanego w przypadku szczurów bez IPC (n = 8)— 65% (62–71).Wnioski: Na podstawie uzyskanych wyników stwierdzono, że hartowanie przez niedokrwienie u szczurów z AIA nie prowadzido istotnej redukcji obszaru martwicy wywołanej 30-minutowym niedokrwieniem i 60-minutową reperfuzją. Możliwe jest, że za zaobserwowany efekt odpowiada obecność ogólnoustrojowego przewlekłego zapalenia. Zanik/ograniczenie korzystnych efektów wynikających z IPC może być jedną z przyczyn zwiększonego ryzyka sercowo-naczyniowego u pacjentów z reumatoidalnym zapaleniem stawów

Pan-caspase inhibitor F573 mitigates liver ischemia reperfusion injury in a murine model.

BACKGROUND:Liver ischemia reperfusion injury (IRI) remains a challenge in liver transplantation. A number of compounds have previously demonstrated efficacy in mitigating IRI. Herein, we applied three specific additive strategies to a mouse IRI screening model to determine their relative potencies in reducing such injury, with a view to future testing in a large animal and clinical ex situ normothermic perfusion setting: 1) F573, a pan-caspase inhibitor, 2) anti-inflammatory anakinra and etanrecept and 3) BMX-001, a mimetic of superoxide dismutase. METHODS:A non-lethal liver ischemia model in mice was used. Additives in the treatment groups were given at fixed time points before induction of injury, compared to a vehicle group that received no therapeutic treatment. Mice were recovered for 6 hours following the ischemic insult, at which point blood and tissue samples were obtained. Plasma was processed for transaminase levels. Whole liver tissue samples were processed for histology, markers of apoptosis, oxidative stress, and cytokine levels. RESULTS:In an in vivo murine IRI model, the F573 treatment group demonstrated statistically lower alanine aminotransferase (ALT) levels (p = 0.01), less evidence of apoptosis (p = 0.03), and lower cytokine levels compared to vehicle. The etanercept with anakinra treatment group demonstrated significantly lower cytokine levels. The BMX-001 group demonstrated significantly decreased apoptosis (p = 0.01) evident on TUNEL staining. CONCLUSIONS:The administration of pan-caspase inhibitor F573 in a murine in vivo model likely mitigates liver IRI based on decreased markers of cellular injury, decreased evidence of apoptosis, and improved cytokine profiles. Anakinra with etanercept, and BMX-001 did not demonstrate convincing efficacy at reducing IRI in this model, and likely need further optimization. The positive findings set rational groundwork for future translational studies of applying F573 during normothermic ex situ liver perfusion, with the aim of improving the quality of marginal grafts

Clearance of transaminases during normothermic ex situ liver perfusion.

BackgroundOne of the most promising applications of liver normothermic machine perfusion (NMP) is the potential to directly assess graft viability and injury. In most NMP studies, perfusate transaminases are utilized as markers of graft injury. Our aim was to further elucidate the metabolism of transaminases by healthy porcine livers during NMP, specifically whether such livers could clear circuit perfusate transaminases.MethodsA highly concentrated transaminase solution was prepared from homogenized liver, with an aspartate aminotransferase (AST) level of 107,427 U/L. Three livers in the treatment group were compared to three controls, during 48 hours of NMP. In the treatment group, the circuit perfusate was injected with the transaminase solution to artificially raise the AST level to a target of 7,500 U/L. Perfusate samples were taken at two-hour intervals and analyzed for biochemistry until NMP end. Graft oxygen consumption and vascular parameters were monitored.ResultsCompared to controls, treated perfusions demonstrated abrupt elevations in transaminase levels (p>0.0001) and lactate dehydrogenase (LDH) (p>0.0001), which decreased over time, but never to control baseline. Liver function, as demonstrated by lactate clearance and oxygen consumption was not different between groups. The treatment group demonstrated a higher portal vein resistance (p = 0.0003), however hepatic artery resistance was similar. Treated livers had higher bile production overall (pConclusionsAddition of high levels of transaminases and LDH to a healthy porcine liver during ex situ perfusion results in progressive clearance of these enzymes, suggesting preserved liver metabolism. Such tolerance tests may provide valuable indicators of prospective graft function