anisomycin and Reperfusion-Injury

The main objective of our research was to explore the neuroprotective effect and underlying mechanism of β-caryophyllene (BCP) pretreatment against cerebral ischemia/reperfusion injury (CIRI). Neurological deficit score, infarct size, and sensorimotor function were assessed 24 h following reperfusion. Additionally, histopathological damage of neurons was evaluated using hematoxylin-eosin staining. The mRNA level of nod-like receptor family pyrin domain-containing 3 (NLRP3) was determined using quantitative real-time PCR. The expressions of p-p38, p38, NLRP3, procaspase-1, and ASC (apoptosis-associated speck-like protein containing a CARD) were measured using western blot analysis. The levels of interleukin-1β (IL-1β) and interleukin-18 (IL-18) were quantified utilizing the ELISA. Our findings indicated that BCP pretreatment significantly reduced the infarct volume, neurologic deficit score, sensorimotor deficits, histopathological damage, and expression of inflammatory factors. Besides, BCP pretreatment effectively suppressed the expression of p-p38, as well as the activation of NLRP3 inflammasome. The administration of anisomycin, an activator of p38 MAPK, was found to notably impede the favorable outcomes conferred by BCP pretreatment, which included reducing the infarct volume, improving the neurologic deficit score, mitigating the sensorimotor deficits, and attenuating the histopathological damage. Furthermore, anisomycin effectively reversed the suppressive impact of BCP on NLRP3 inflammasome activation. This research uncovered that pretreatment with BCP has the potential to alleviate CIRI by effectively suppressing the activation of NLRP3 inflammasome through the p38 MAPK signaling pathway.

Topics: Animals; Anisomycin; Brain Ischemia; Inflammasomes; MAP Kinase Signaling System; Neuroprotection; NLR Family, Pyrin Domain-Containing 3 Protein; p38 Mitogen-Activated Protein Kinases; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Ischemia-reperfusion injury (IRI) contributes to liver damage in many clinical situations, such as liver resection and liver transplantation. In the present study, we investigated the effects of the antioxidant, anti-inflammatory, and anticancer agent salidroside (Sal) on hepatic IRI in mice. The mice were randomly divided into six groups: normal control, Sham, Sal (20 mg/kg), IRI, IRI + Sal (10 mg/kg), and IRI + Sal (20 mg/kg). We measured liver enzymes, proinflammatory cytokines, TNF-α and interleukin-6, and apoptosis- and autophagy-related marker proteins at 2, 8, and 24 hours after reperfusion. Components of mitogen-activated protein kinase (MAPK) signaling, including P-38, jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK), were also measured using an MAPK activator anisomycin to deduce their roles in hepatic IRI. Our results show that Sal safely protects hepatocytes from IRI by reducing levels of liver enzymes in the serum. These findings were confirmed by histopathology. We concluded that Sal protects hepatocytes from IRI partly by inhibiting the activation of MAPK signaling, including the phosphorylation of P38, JNK, and ERK. This ameliorates inflammatory reactions, apoptosis, and autophagy in the mouse liver.

Topics: Animals; Anisomycin; Apoptosis; Autophagy; Cytokines; Enzyme Activators; Glucosides; Hepatocytes; Kidney Function Tests; Liver; Liver Function Tests; Male; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; Phenols; Phosphorylation; Protective Agents; Reperfusion Injury

In previous studies, inhibition of mitogen-activated protein kinase (MAP) p38 significantly improved recovery and attenuated apoptosis after retinal ischemia in rats. Yet, ischemic preconditioning (IPC) attenuated the ischemia-induced increase in p38 expression. We hypothesized that p38 was required for induction of ischemic tolerance by IPC. We examined the mechanisms of involvement of p38 in IPC neuroprotection. IPC or ischemia was induced in rat retina in vivo. Recovery after ischemia performed 24h after IPC was assessed functionally (electroretinography) and histologically at 7d after ischemia in the presence or absence of inhibition of p38. We examined the role of p38alpha in the mimicking of IPC produced by opening mitochondrial KATP channels using diazoxide, or stimulation of p38 activation by anisomycin. The importance of adenosine receptors in p38 activation after IPC was assessed using specific blockers of adenosine A1 and A2a receptors. Interfering RNA (siRNA) or SB203580 was used to block p38alpha. Phosphorylated p38 levels were measured. Phosphorylated p38 protein increased with IPC. Interfering RNA (siRNA) to p38alpha prior to IPC, or inhibiting p38 activation with SB203580, with ischemia following 24h later, significantly attenuated the neuroprotective effect of IPC. Anisomycin administered to increase p38 mimicked IPC, an effect blocked by SB203580. IPC-mimicking with diazoxide, an opener of mitochondrial KATP channels, was diminished with p38alpha siRNA. Adenosine receptor blockade did not decrease the elevated levels of phosphorylated p38 after IPC. Specific inhibition of p38alpha suggests that this MAPK is involved in the protective effects of IPC, and that p38 is downstream of mitochondrial KATP channels, but not adenosine receptors, in this neuroprotection.

Topics: Adenosine A1 Receptor Antagonists; Adenosine A2 Receptor Antagonists; Animals; Anisomycin; Diazoxide; Disease Models, Animal; Electroretinography; Enzyme Activators; Imidazoles; Intraocular Pressure; Ischemia; Ischemic Preconditioning; Mitogen-Activated Protein Kinase 14; Phosphorylation; Potassium Channels; Protein Kinase Inhibitors; Pyridines; Rats; Rats, Sprague-Dawley; Receptor, Adenosine A1; Receptor, Adenosine A2A; Reperfusion Injury; Retinal Neurons; Retinal Vessels; RNA Interference; Signal Transduction; Time Factors