Targeting the PI3K/AKT signaling pathway with PNU120596 protects against LPS-induced acute lung injury.

OBJECTIVES: This study investigated the potential therapeutic benefits of PNU120596, a positive allosteric modulator of the α7 nicotinic acetylcholine receptor (α7nAChR), in mitigating acute lung injury (ALI) induced by lipopolysaccharide (LPS) in a mouse model. Specifically, we sought to examine the impact of PNU120596 on the PI3K/AKT signaling pathway in the context of ALI. METHODS: ALI was induced in mice by LPS administration, and the protective effects of PNU120596 were assessed. Lung injury, lung function, and the inflammatory response were evaluated. Additionally, the activation of the PI3K/AKT signaling pathway was examined, along with the levels of inflammatory factors and oxidative stress markers. KEY FINDINGS: PNU120596 significantly ameliorated LPS-induced lung injury, improved lung function, and reduced the inflammatory response in the mouse model of ALI. Furthermore, we observed that PNU120596 inhibited the activation of the PI3K/AKT signaling pathway, which was associated with decreased levels of inflammatory factors and oxidative stress markers. CONCLUSIONS: PNU120596 exhibits promising therapeutic potential for the treatment of acute lung injury, potentially by targeting the PI3K/AKT signaling pathway. These findings suggest that modulation of the α7 nicotinic acetylcholine receptor with PNU120596 may offer a viable strategy for the management of ALI, warranting further investigation and potential clinical applications.

Amygdala-Targeted Relief of Neuropathic Pain: Efficacy of Repetitive Transcranial Magnetic Stimulation in NLRP3 Pathway Suppression.

This study investigates the effectiveness of repetitive transcranial magnetic stimulation (rTMS) as a nonpharmacological approach to treating neuropathic pain (NP), a major challenge in clinical research. Conducted on male Sprague-Dawley rats with NP induced through chronic constriction injury of the sciatic nerve, the research assessed pain behaviors and the impact of rTMS on molecular interactions within the amygdala. Through a comprehensive analysis involving Mechanical Withdrawal Threshold (MWT), Thermal Withdrawal Latency (TWL), RNA transcriptome sequencing, RT-qPCR, Western blotting, immunofluorescence staining, and Co-Immunoprecipitation (Co-IP), the study focused on the expression and interaction of integrin αvß3 and its receptor P2X7R. Findings reveal that rTMS significantly influences the expression of integrin αvß3 in NP models, suggesting an inhibition of the NP-associated NLRP3 inflammatory pathway through the disruption of integrin αvß3-P2X7R interactions. These outcomes highlight the potential of rTMS in alleviating NP by targeting molecular interactions within the amygdala, offering a promising therapeutic avenue for managing NP.

hUC-MSC-EV-miR-24 enhances the protective effect of dexmedetomidine preconditioning against myocardial ischemia-reperfusion injury through the KEAP1/Nrf2/HO-1 signaling.

The cardioprotective effect of microRNAs (miRNAs) on myocardial ischemic-reperfusion (I/R) injury has been documented. Here, we aim to decipher the mechanism of miR-24 delivered by human umbilical cord mesenchymal stem cell-derived extracellular vesicles (hUC-MSC-EVs) in myocardial I/R injury after dexmedetomidine (DEX) preconditioning. We collected and identified hUC-MSCs and extracted EVs, which were co-cultured with DEX-preconditioned hypoxia/reoxygenation (H/R) cardiomyocyte models or injected into I/R mouse models. The cardiomyocytes and myocardial injury were evaluated by molecular biology experiments. miR-24 was highly expressed in hUC-MSC-EVs. hUC-MSC-EVs could transfer miR-24 into cardiomyocytes where miR-24 augmented cell viability and inhibited cell apoptosis after DEX preconditioning. In the co-culture system of RAW264.7 macrophages with hUC-MSC-EVs, miR-24 promoted M2-type polarization of macrophages and reduced M1-type macrophage polarization. Mechanistically, miR-24 targeted KEAP1 and inhibited its expression, resulting in disruption of the Nrf2/HO-1 signaling. In vivo data confirmed that miR-24 delivered by hUC-MSC-EVs enhanced the suppressing effect of DEX preconditioning on inflammation and apoptosis in rats following myocardial I/R injury. Overall, miR-24 delivered by hUC-MSC-EVs can promote M2 polarization of macrophages and enhance the protective effect of DEX preconditioning on myocardial I/R injury by down-regulating the KEAP1/Nrf2/HO-1 signaling axis.

Salvianolic acid B alleviates comorbid pain in depression induced by chronic restraint stress through inhibiting GABAergic neuron excitation via an ERK-CREB-BDNF axis-dependent mechanism.

Pain comorbid with depression occurred frequently in clinical settings. This study aims to explore the molecular mechanism underlying antidepressant and analgetic effect of salvianolic acid B (SalB) in comorbid pain in depression induced by chronic restraint stress (CRS), which associates with GABAergic neuron activation in the amygdala and the ERK-CREB-BDNF signaling pathway. The differentially expressed genes related to comorbid pain in CRS-induced depression were screened through bioinformatics analysis. After CRS treatment for 3 weeks, depression-like behaviors were developed in GAD2-tdT mice. The retrograde tracer cholera toxin B subunit combined with retrograde tracer CTB-488 was injected into the parafascicular nucleus of thalamus to project GABAergic neurons to observe the labeling of neurons in the whole brain. After treatment with SalB and ERK-CREB-BDNF signaling pathway inhibitor, CRS mice showed a variety of depression-like behaviors, accompanied by enhanced activity of GABAergic neurons in the amygdala projecting to parafascicular nucleus of thalamus. BDNF underexpression occurred in the CRS mice. Overexpressed BDNF activated ERK-CREB-BDNF signaling pathway to alleviate comorbid pain in CRS-induced depression. After intraperitoneal injection of SalB, the depression-like behaviors and pain threshold in CRS mice were alleviated, the effects of which could be eliminated by ERK-CREB-BDNF signaling pathway antagonist. Collectively, SalB inhibits the excitation of GABAergic neurons in the amygdala and activates the ERK-CREB-BDNF signaling pathway through the parafascicular nucleus of thalamus, whereby alleviating comorbid pain in CRS-induced depression in mice.

PIAS1 alleviates diabetic peripheral neuropathy through SUMOlation of PPAR-γ and miR-124-induced downregulation of EZH2/STAT3.

Diabetic peripheral neuropathy (DPN) is a frequently occurring chronic complication of diabetes. In this study, we aim to explore the regulatory mechanism of protein inhibitor of activated STAT1 (PIAS1) in DPN in terms of autophagy and apoptosis of Schwann cells. The SUMOlation of PPAR-γ by PIAS1 was examined, and ChIP was performed to verify the binding of PPAR-γ to miR-124 promoter region. Dual-luciferase gene reporter assay was used to validate the binding affinity between miR-124 and EZH2/STAT3. Following loss- and gain-of-function experiments, in vitro assays in high glucose-treated Schwann cells (SC4) and in vivo assays in db/db and ob/ob mice were performed to detect the effects of PIAS1 on autophagy and apoptosis of Schwann cells as well as symptoms of DPN by regulating the PPAR-γ-miR-124-EZH2/STAT3. The expression of PIAS1, PPAR-γ, and miR-124 was downregulated in the sciatic nerve tissue of diabetic mice. PIAS1 enhanced the expression of PPAR-γ through direct binding and SUMOlation of PPAR-γ. PPAR-γ enhanced the expression of miR-124 by enhancing the promoter activity of miR-124. Furthermore, miR-124 targeted and inversely modulated EZH2 and STAT3, promoting the autophagy of Schwann cells and inhibiting their apoptosis. In vivo experiments further substantiated that PIAS1 could promote the autophagy and inhibit the apoptosis of Schwann cells through the PPAR-γ-miR-124-EZH2/STAT3 axis. In conclusion, PIAS1 promoted SUMOlation of PPAR-γ to stabilize PPAR-γ expression, which upregulated miR-124 to inactivate EZH2/STAT3, thereby inhibiting apoptosis and promoting autophagy of Schwann cells to suppress the development of DPN.

microRNA-26a shuttled by extracellular vesicles secreted from adipose-derived mesenchymal stem cells reduce neuronal damage through KLF9-mediated regulation of TRAF2/KLF2 axis.

Extracellular vesicles (EVs) are nano-sized vesicles secreted actively by numeorus cells and have fundamental roles in intercellular communication through shuttling functional RNAs. This study sets out to elucidate the role of microRNA-26a (miR-26a) shuttled by EVs derived from adipose-derived mesenchymal stem cells (ASCs) in neuronal damage. After extraction and identification of ASC-derived EVs (ASC-EVs), mouse cortical neuronal cells were selected to establish an in vivo cerebral ischemia/reperfusion mouse model and an in vitro oxygen glucose deprivation/reperfusion (OGD/RP) cell model. The downstream genes of miR-26a were analyzed. The gain- and loss-of function of miR-26a and KLF9 was performed in mouse and cell models. Neuronal cells were subjected to co-culture with ASC-EVs and biological behaviors were detected by flow cytometry, Motic Images Plus, TTC, TUNEL staining, qRT-PCR and western blot analysis. ASC-EVs protected neuronal cells against neuronal damage following cerebral ischemia/reperfusion, which was related to transfer of miR-26a into neuronal cells. In neuronal cells, miR-26a targeted KLF9. KLF9 could suppress the expression of TRAF2 and KLF2 to facilitate neuronal damage. In vitro and in vivo results showed that miR-26a delivered by ASC-EVs inhibited neuronal damage. In summary, ASC-EVs-derived miR-26a can arrest neuronal damage by disrupting the KLF9-meidated suppression on TRAF2/KLF2 axis.

Relationship between the migratory, metabolic and proliferative ability of fibrochondrocytes and the meniscal fragment size: an in vivo study.

OBJECTIVE: To investigate the migratory, metabolic and proliferative ability of rabbit fibrochondrocytes in meniscal fragments of different sizes under an in vivo subcutaneous environment. METHODS: Adult, male, New Zealand white rabbit menisci were harvested and the inner two-thirds of each were minced into different sizes: 0.5 × 0.5 × 0.5 mm (group A); 1.0 × 1.0 × 1.0 mm (group B); 2.0 × 2.0 × 2.0 mm (group C). Meniscal fragments were packed into a fascia sheath, then implanted subcutaneously. At weeks 1, 2 and 3 postimplantation, meniscal fragments were harvested; cell migration and viability were then evaluated by confocal laser scanning microscopy and haematoxylin and eosin staining. Aggrecan was detected using Safranin O and Fast Green staining, and protein levels of types I and II collagen, and proliferating cell nuclear antigen (PCNA), were evaluated by immunohistochemistry. RESULTS: Protein levels of types I and II collagen and PCNA, and fibrochondrocyte migration, were highest in group A compared with groups B and C, but aggrecan staining remained the same across the groups. CONCLUSION: There was an inverse relationship between the migratory, metabolic and proliferative abilities of rabbit fibrochondrocytes and meniscal fragment size.