The role of AMPK-Sirt1-autophagy pathway in the intestinal protection process by propofol against regional ischemia/reperfusion injury in rats

Muscle-derived factor alleviated cognitive impairment caused by intestinal ischemia-reperfusion

Intestinal ischemia/reperfusion (II/R) is a common and grave clinical event, with high morbidity and mortality which can cause cerebral dysfunctions. There are no ideal prevention and treatment measures yet. The present study aimed to determine whether muscle-derived factors can alleviate gut-associated cerebral dysfunctions (GACD) following II/R. We measured the tibialis anterior muscle thickness and irisin levels in patients with and without cognitive dysfunction following cardiopulmonary bypass surgery, calculating the correlation between irisin and cognitive impairment. We found that this protective effect is related to muscle-derived irisin. To elucidate the role of irisin in improving GACD, we knocked out FNDC5 to deplete endogenous irisin and supplemented exogenous irisin. Mechanistic insights into irisin's effects on GACD were investigated using in vivo and in vitro models, incorporating techniques such as transmission electron microscopy, protein docking analysis, gene overexpression, and western blotting. FNDC5/irisin deficiency aggravated cognitive impairments, the pro-inflammation microglia activation, oxidative injury, inflammatory response, neuronal apoptosis and ferroptosis, while recombinant FNDC5/irisin reversed the above changes leading to neurostructural and cognition recovery. Mechanistically, thioredoxin-interacting protein (TXNIP) was activated in the II/R-related neuropathology and was deteriorated in FNDC5/irisin knockout mice. Our results highlight the potential of FNDC5/irisin to slow GACD, providing new insights and potential therapeutic strategies for the prevention and treatment of GACD.

Beyond organ isolation: The bidirectional crosstalk between cerebral and intestinal ischemia-reperfusion injury via microbiota-gut-brain axis

Ischemia-reperfusion injury (IRI) represents a pathophysiological phenomenon of profound clinical relevance that poses considerable threats to patient safety. IRI may manifest in a variety of clinical contexts including, but not limited to, sepsis, organ transplantation, shock, myocardial infarction, cerebral ischemia, and stroke. Critically, IRI exhibits complex interactions across different organs, with effects that surpass mere localized tissue damage. These impacts can amplify damage to both adjacent and remote organs through pathways such as the gut-brain axis and the gut-lung axis, facilitated by intricate signaling mechanisms. Noteworthy is the interaction between gut IRI and brain IRI, which involves sophisticated neuroendocrine, systemic, and immune mechanisms coordinated through the microbiome-gut-brain axis. This review seeks to delve into the intricate interactions between gut and brain IRI, viewed through the lens of the microbiota-gut-brain axis. It aims to assess its translational potential in clinical settings, provide a theoretical foundation for developing relevant therapeutic strategies, and pinpoint novel directions for research.

The dual effects of propofol down-regulating PD-L1 expression and inhibiting autophagy to reduce cerebral ischemia reperfusion injury

Propofol, an anesthetic, has shown neuroprotective effects in animal and cellular models of cerebral ischemia-reperfusion (I/R) injury, likely by suppressing I/R-induced excessive autophagy. PD-L1 and immune escape are implicated in experimental stroke outcomes, but their mechanisms remain unclear. Here, we demonstrate that oxygen-glucose deprivation/reoxygenation (OGD/R) in astrocytes upregulates PD-L1 expression and autophagy, effects that are attenuated by propofol treatment via the NF-κB pathway. In vivo, propofol protects mice from I/R injury by downregulating PD-L1, inflammatory factors, and autophagy. Clinically, craniotomy patients receiving propofol exhibited higher CD3+ and CD4+ T lymphocyte percentages and lower PD-L1 and inflammatory factor levels. Our findings elucidate propofol's dual role in downregulating PD-L1 and inhibiting autophagy in cerebral I/R injury, suggesting its potential as a novel therapeutic strategy to mitigate inflammation and immune dysregulation.

Dexmedetomidine alleviates intestinal ischemia/reperfusion injury by modulating intestinal neuron autophagy and mitochondrial homeostasis via Nupr1 regulation

Intestinal ischemia/reperfusion injury (I/R) is a common yet challenging-to-treat condition, presenting a significant clinical challenge. This study aims to investigate the protective mechanisms of Dexmedetomidine (Dex) against I/R injury, with a particular focus on its role in regulating autophagy activity in intestinal neurons and maintaining mitochondrial homeostasis. Experimental findings demonstrate that Dex can mitigate intestinal damage induced by I/R through the modulation of autophagy activity and mitochondrial function in intestinal neurons by suppressing the expression of Nupr1. This discovery sheds light on a new molecular mechanism underlying the potential efficacy of Dex in treating intestinal I/R injury, offering valuable insights for clinical therapy.

Advancements in the study of acute lung injury resulting from intestinal ischemia/reperfusion

Intestinal ischemia/reperfusion is a prevalent pathological process that can result in intestinal dysfunction, bacterial translocation, energy metabolism disturbances, and subsequent harm to distal tissues and organs via the circulatory system. Acute lung injury frequently arises as a complication of intestinal ischemia/reperfusion, exhibiting early onset and a grim prognosis. Without appropriate preventative measures and efficacious interventions, this condition may progress to acute respiratory distress syndrome and elevate mortality rates. Nonetheless, the precise mechanisms and efficacious treatments remain elusive. This paper synthesizes recent research models and pertinent injury evaluation criteria within the realm of acute lung injury induced by intestinal ischemia/reperfusion. The objective is to investigate the roles of pathophysiological mechanisms like oxidative stress, inflammatory response, apoptosis, ferroptosis, and pyroptosis; and to assess the strengths and limitations of current therapeutic approaches for acute lung injury stemming from intestinal ischemia/reperfusion. The goal is to elucidate potential targets for enhancing recovery rates, identify suitable treatment modalities, and offer insights for translating fundamental research into clinical applications.

Construction of preclinical evidence for propofol in the treatment of reperfusion injury after acute myocardial infarction: A systematic review and meta-analysis

Propofol, a commonly used intravenous anesthetic, has demonstrated potential in protecting against myocardial ischemia/reperfusion injury (MIRI) based on preclinical animal studies. However, the clinical benefits of propofol in this context are subject to debate. We conducted a systematic search across eight databases to identify all relevant animal studies investigating the preventive effects of propofol on MIRI until October 30, 2023. We assessed the methodological quality of the included studies using SYRCLE's bias risk tool. Statistical analysis was performed using STATA 15.1. The primary outcome measures analyzed in this study were myocardial infarct size (IS) and myocardial injury biomarkers. This study presents a comprehensive analysis of 48 relevant animal studies investigating propofol's preventive effects on MIRI. Propofol administration demonstrated a reduction in myocardial IS and decreased levels of myocardial injury biomarkers (CK-MB, LDH, cTnI). Moreover, propofol improved myocardial function parameters (+dp/dtmax, -dP/dtmax, LVEF, LVFS), exhibited favorable effects on inflammatory markers (IL-6, TNF-α) and oxidative stress markers (SOD, MDA), and reduced myocardial cell apoptotic index (AI). These findings suggest propofol exerts cardioprotective effects by reducing myocardial injury, decreasing infarct size, and improving heart function. However, the absence of animal models that accurately represent comorbidities such as aging and hypertension, as well as inconsistent administration methods that align with clinical practice, may hinder its clinical translation. Further robust investigations are required to validate these findings, elucidate the underlying mechanisms of propofol, and facilitate its potential translation into clinical practice.

TXNIP/NLRP3 aggravates global cerebral ischemia-reperfusion injury-induced cognitive decline in mice

Global cerebral ischemia/reperfusion (GCI/R) injury poses a risk for cognitive decline, with neuroinflammation considered pivotal in this process. This study aimed to unravel the molecular mechanisms underlying GCI/R injury and propose a potential therapeutic strategy for associated cognitive deficits. Utilizing bioinformatics analysis of a public microarray profile (GSE30655 and GSE80681) in cerebral ischemic mice, it was observed that neuroinflammation emerged as a significant gene ontology item, with an increase in the expression of thioredoxin-interacting protein (TXNIP) and NLRP3 genes. Experimental models involving bilateral occlusion of the common carotid arteries in mice revealed that GCI/R induced cognitive impairment, along with a time-dependent increase in TXNIP and NLRP3 levels. Notably, TXNIP knockdown alleviated cognitive dysfunction in mice. Furthermore, the introduction of adeno-associated virus injection with TXNIP knockdown reduced the number of activated microglia, apoptosis neurons, and levels of oxidative stress and inflammatory cytokines in the hippocampus. Collectively, these findings underscore the significance of TXNIP/NLRP3 in the hippocampus in exacerbating cognitive decline due to GCI/R injury, suggesting that TXNIP knockdown holds promise as a therapeutic strategy.

Morphological and biochemical characteristics associated with autophagy in gastrointestinal diseases

Autophagy is a cellular catabolic process characterized by the formation of double-membrane autophagosomes. Transmission electron microscopy is the most rigorous method to clearly visualize autophagic engulfment and degradation. A large number of studies have shown that autophagy is closely related to the digestion, secretion, and regeneration of gastrointestinal (GI) cells. However, the role of autophagy in GI diseases remains controversial. This article focuses on the morphological and biochemical characteristics of autophagy in GI diseases, in order to provide new ideas for their diagnosis and treatment.

Corilagin attenuates intestinal ischemia/reperfusion injury in mice by inhibiting ferritinophagy-mediated ferroptosis through disrupting NCOA4-ferritin interaction

AIMS

Intestinal ischemia reperfusion (II/R) is a common clinical emergency. Ferroptosis is reported to play a role in II/R injury. Our previous studies revealed that corilagin significantly attenuates intestinal ischemia/reperfusion injuries. However, the underlying molecular mechanism is unclear and requires further study.

MATERIALS AND METHODS

DAO, GSSG/T-GSH, MDA, and Fe2+ were measured by assay kits, 4-HNE was assessed by IHC, and 15-LOX was measured by ELISA. Mitochondrial damage was observed by TEM and cellular oxidation levels were detected by C11-BODIPY 581/591 and DHE probes. LC3, p62, Beclin1, ACSL4, GPX4, NCOA4, and ferritin expression were examined by WB in vivo and in vitro. IF, co-IF, q-PCR, and constructed NCOA4-knock-down IEC-6 cells were used to evaluate the role of NCOA4 in the effect of corilagin against II/R injury. Temporal and nucleoplasmic variations with or without corilagin were observed by WB. Co-IP and molecular docking were used to investigate the NCOA4-ferritin interaction.

KEY FINDINGS

Corilagin attenuated II/R-induced ferroptosis both in vitro and in vivo. Further study revealed that the anti-ferroptosis bioactivity of corilagin might be due to the modulation of iron homeostasis via inhibition of ferritinophagy in an NCOA4-dependent manner.

SIGNIFICANCE

Corilagin might be a potential therapeutic agent for II/R-induced tissue injury.

Crucial role of autophagy in propofol-treated neurological diseases: a comprehensive review

Neurological disorders are the leading cause of disability and death globally. Currently, there is a significant concern about the therapeutic strategies that can offer reliable and cost-effective treatment for neurological diseases. Propofol is a widely used general intravenous anesthetic in the clinic. Emerging studies demonstrate that propofol exerts neuroprotective effects on neurological diseases and disorders, while its underlying pathogenic mechanism is not well understood. Autophagy, an important process of cell turnover in eukaryotes, has been suggested to involve in the neuroprotective properties developed by propofol. In this narrative review, we summarized the current evidence on the roles of autophagy in propofol-associated neurological diseases. This study highlighted the effect of propofol on the nervous system and the crucial roles of autophagy. According to the 21 included studies, we found that propofol was a double-edged sword for neurological disorders. Several eligible studies reported that propofol caused neuronal cell damage by regulating autophagy, leading to cognitive dysfunction and other neurological diseases, especially high concentration and dose of propofol. However, some of them have shown that in the model of existing nervous system diseases (e.g., cerebral ischemia-reperfusion injury, electroconvulsive therapy injury, cobalt chloride-induced injury, TNF-α-induced injury, and sleep deprivation-induced injury), propofol might play a neuroprotective role by regulating autophagy, thus improving the degree of nerve damage. Autophagy plays a pivotal role in the neurological system by regulating oxidative stress, inflammatory response, calcium release, and other mechanisms, which may be associated with the interaction of a variety of related proteins and signal cascades. With extensive in-depth research in the future, the autophagic mechanism mediated by propofol will be fully understood, which may facilitate the feasibility of propofol in the prevention and treatment of neurological disorders.

When less is more: Experimental Bishop-Koop technique for reduction in the use of laboratory animals for intestinal pathophysiological studies

The use of animals to gain knowledge and understanding of diseases needs to be reduced and refined. In the field of intestinal research, because of the complexity of the gut immune system, living models testing is mandatory. Based on the 3Rs (replacement, reduction and refinement) principles, we aimed to developed and apply the derived-intestinal surgical procedure described by Bishop and Koop (BK) in rats to refine experimental gastrointestinal procedures and reduce the number of animals used for research employing two models of intestinal inflammation: intestinal ischemia-reperfusion injury and chemical-induced colitis. Our results show the feasibility of the application of the BK technique in rodents, with good success after surgical procedure in both small and large intestine (100% survival, clinical recovery and weight regain). A considerable reduction in the use of the number of rats in both intestinal inflammation models (80% in case of intestinal ischemia-reperfusion damage and 66.6% in chemical-induced colitis in our experimental design) was achieved. Compared with conventional experimental models described by various research groups, we report excellent reproducibility of intestinal damage and functionality, survival rate and clinical status of the animals when BK is applied.