Ampelopsin alleviates sevoflurane-induced cognitive dysfunction by mediating NF-κB pathway in aged rats

Carnosol alleviates sevoflurane-induced cognitive dysfunction by mediating NF-κB pathway in aged rats

Postoperative Cognitive Dysfunction (POCD) is a neurological disorder of unconsciousness due to cognitive regression after surgical anesthesia. However, the specific mechanism has not yet been clarified. Sevoflurane (SEV) is one of the most commonly used anesthetics in clinical practice, and how SEV mediates the generation of POCD is unclear. Carnosol, a natural ingredient, has been reported to have various beneficial effects such as anti-inflammatory, immune enhancement, and so forth, but how it ameliorates SEV-mediated neurotoxicity remains unclear. This study aimed to induce a POCD model in aged rats by SEV and to elucidate how Carnosol ameliorated SEV-mediated neurotoxicity. The effects of Carnosol on the expression of inflammatory factors in rat hippocampus mediated by SEV were determined by enzyme-linked immunoassay and polymerase chain reaction experiments; the effects of Carnosol on the expressions of Iba-1 and glial fibrillary acidic protein after SEV-mediated activation of rat microglia were clarified by immunofluorescence and Western blotting (WB); The effects of Carnosol on SEV-mediated neuronal apoptosis were studied by terminal deoxynucleotidyl transferase dUTP nick end labeling and WB; the specific signaling pathways regulated by Carnosol were elucidated by WB. The results showed that Carnosol can improve the cognitive dysfunction and reduce neuroinflammation in aged rats induced by SEV; Carnosol can reduce the activation of microglia and inhibit neuronal apoptosis in aged rats induced by SEV; Carnosol can phosphorylate p65 and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha regulates the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. Carnosol can attenuate SEV-induced neuroinflammation, prevent microglial activation and inhibit neuronal apoptosis by modulating the NF-κB pathway.

Protective role of trametenolic acid B against sevoflurane-induced cognitive impairments by its different regulatory modalities of mir-329-3p in neurons and microglia

BACKGROUND

Postoperative cognitive dysfunction induced by anesthetics commonly occurs in elderly patients. This study aimed to evaluate the protective role of trametenolic acid B (TAB) in sevoflurane-induced cognitive impairments, and explore the underlying mechanisms.

METHODS

Animal and cell experiments were performed in rats, differentiated PC12 and HAPI cells by exposing to 2% sevoflurane for 5 h. Different concentration (20, 40 and 80 µg/mL) of TAB was administrated in rats and cells. The cognitive function of rats was evaluated using the Morris water maze test and fear conditioning test. The cell proliferation and apoptosis were investigated using a CCK-8 assay and the flow cytometry. Pro-inflammatory cytokines in microglia were measured using ELISA kits. A miRNA microarray assay was conducted to screen differentially expressed miRNAs by TAB in both PC12 and HAPI cells. The luciferase reporter assay and western blot assay were used to assess the E2F1/CCNA2 and NF-κB pathways.

RESULTS

TAB significantly alleviated sevoflurane-induced cognitive impairments in rats, improved PC12 cell viability, and inhibited the neuroinflammation of HAPI cells. miR-329-3p was downregulated in PC12 cells but upregulated in HAPI cells by TAB treatment, which mediated the effects of TAB on neurotoxicity and neuroinflammation. E2F1 and NF-κB P65 were two targets of miR-329-3p, and the E2F1/CCNA2 and NF-κB pathways were inhibited by miR-329-3p in PC12 and HAPI cells, respectively.

CONCLUSIONS

All the results provide evidence for the protective role of TAB against sevoflurane-induced cognitive impairments, which was achieved by alleviating neurotoxicity and neuroinflammation through differentially regulating miR-329-3p in neurons and microglia.

Electroacupuncture Pretreatment Ameliorates Anesthesia and Surgery-Induced Cognitive Dysfunction via Activation of an α7-nAChR Signal in Aged Rats

OBJECTIVE

Postoperative cognitive dysfunction (POCD) after anesthesia and surgery (AS) is a common complication in the elderly population. A cholinergic-dependent signal, the alpha7-nicotinic acetylcholine receptor (α7-nAChR), has been suggested to regulate cognitive processes in a variety of neurologic diseases. In the current study, we determined whether electroacupuncture (EA) pretreatment ameliorates AS-induced POCD in aged rats, as well as the underlying mechanism.

METHODS

Male Sprague-Dawley rats (20 months old) were randomly assigned to the following 5 groups (n=12): vehicle; POCD (tibial fracture surgery); EA plus POCD; EA plus POCD and alpha-bungarotoxin (α-BGT); and POCD plus α-BGT groups. Alpha-bungarotoxin (1 μg/kg), a selective antagonist of α7-nAChR, was administrated via intraperitoneal injection before EA. Thirty days post-AS, the Morris water maze and a novel objective recognition test were used to evaluate cognitive function. Neuronal amount, apoptosis, microglial activation, percentage of high mobility group box 1 (HMGB1)- and nuclear factor-κB (NF-κB)-positive microglia, and levels of HMGB-1 downstream factors, including NF-κB, interleukin-6 (IL-6), and IL-1β, were detected by Nissl staining, immunofluorescence, and Western blot assays.

RESULTS

EA pretreatment significantly increased crossing platform times and elevated the time with a novel object, restored the quantity of neurons, decreased TUNEL-positive neurons, alleviated activation of microglia, downregulated expression of HMGB1 and NF-κB in the microglia, and reduced levels of phosphor-NF-κB, IL-6, and IL-1β 35 days after AS, while α-BGT partially reversed these changes.

CONCLUSION

EA pretreatment improved AS-induced POCD in aged rats, and the underlying mechanism may be associated with inhibition of HMGB1-NF-κB via an α7-nAChR signal in the microglia.

microRNA-103a-3p confers protection against lipopolysaccharide-induced sepsis and consequent multiple organ dysfunction syndrome by targeting HMGB1

BACKGROUND

Sepsis and subsequent multiple organ dysfunction syndrome (MODS) have high global incidence and mortality rate, imposing tremendous health burden. microRNAs (miRNAs or miRs) are implicated in the pathogenesis of sepsis and MODS. The aim of this study is to explore the potential mechanisms of miR-103a-3p targeted high mobility group box 1 (HMGB1) involvement in the pathogenesis of sepsis complicated with multiple organ dysfunction syndrome (MODS).

METHODS

A mouse sepsis model was induced by lipopolysaccharide (LPS). Bone marrow-derived macrophages were collected and LPS was used to establish a cellular inflammation model. Targeted binding between miR-103a-3p and HMGB1 was verified by a double luciferase assay and their roles in LPS-induced sepsis were further explored using gain-of-function experiments.

RESULTS

miR-103a-3p was decreased while HMGB1 was increased in sepsis. In LPS-induced mouse sepsis models, the downregulation of HMGB1 was found to result in reductions in NO, TNF-α, IL-1β, IL-6, lung myeloperoxidase activity, pulmonary microvascular albumin leakage, serum alanine aminotransferase, aspartate aminotransferase activity, and lung and liver tissue apoptosis. Additionally, decreased HMGB1 blunted the inflammatory response and increased survival rate of modeled mice. Importantly, HMGB1 was confirmed to a target gene of miR-103a-3p. In cellular inflammation models, miR-103a-3p was found to alleviate LPS-induced sepsis and MODS in vitro by decreasing HMGB1.

CONCLUSIONS

Taken together, our results demonstrated the inhibitory role of miR-103a-3p in sepsis via inhibiting HMGB1 expression.