Aims Microglia-mediated neuroinflammation plays an important role in the pathological process of ischemic stroke, and the effect of imperatorin on post-stroke neuroinflammation is not fully understood. Methods Primary microglia were treated with imperatorin for 2 h followed by LPS (100 ng/ml) for 24 h. The expression of inflammatory cytokines was detected by RT-PCR, ELISA, and Western blot. The activation of MAPK and NF-κB signaling pathways were analyzed by Western blot. The ischemic insult was determined using a transient middle cerebral artery occlusion (tMCAO) model in C57BL/6J mice. Behavior tests were used to assess the neurological deficits of MCAO mice. TTC staining was applied to measure infract volume. Results Imperatorin suppressed LPS-induced activation of microglia and pro-inflammatory cytokines release and attenuated ischemic injury in MCAO mice. The results of transcriptome sequencing and Western blot revealed that downregulation of MAPK and NF-κB pathways might contribute to the protective effects of imperatorin. Conclusions Imperatorin downregulated MAPK and NF-κB signaling pathways and exerted anti-inflammatory effects in ischemic stroke, which indicated that imperatorin might be a potential compound for the treatment of stroke.
Feifei Chen,Hui Jiang,Xueyi Song,Jianfeng Wang,Xu Ma,Quan Zhou,Abdullah Al Mamun,Lingna Li,Yunfang Zhou,Hongbin Xu,Shuanghu Wang
Introduction: Cerebral ischemic stroke has high mortality and disability rates with limited targeted therapeutic strategies. Biomimetic nanocarriers can optimize drug delivery efficiency and exert neuroprotection effects, providing a promising strategy for ischemia-reperfusion injury treatment.Methods: Hollow mesoporous silica nanoparticles (HMSNs) were synthesized via an improved Stoer method and loaded with imperatorin (IMP). Subsequently, neutrophil cell membranes (NCM) extracted from DMSO-induced HL-60 cells were coated onto the nanoparticles to construct NCM/IMP@HMSNs. Nanomaterial characterization was carried out. In vitro oxygen-glucose deprivation/reoxygenation (OGD/R) models in SH-SY5Y cells and in vivo rat middle cerebral artery occlusion/reperfusion (MCAO/R) models were established to explore the underlying neuroprotective mechanisms.Results: The synthesized NCM/IMP@HMSNs nanoparticles possessed uniform particle size (~143 nm) and favorable stability, with an encapsulation efficiency of 31.84%. In vitro results revealed that IMP significantly increased the viability of OGD/R-injured SH-SY5Y cells compared with the model group. In vivo experiments showed that NCM/IMP@HMSNs efficiently accumulated in ischemic brain tissue, notably decreased mNSS scores, and reduced cerebral infarct volume by approximately 33.31% compared with the MCAO/R group. This nanosystem activated the Nrf2/ARE/Keap1 pathway, thereby upregulating HO-1 expression to strengthen antioxidant capacity, alleviate the accumulation of cerebral oxidative stress products, and regulate the activities of SOD, GSH, CAT and LDH.Conclusion: The biomimetic NCM/IMP@HMSNs nanoplatform enhances the neuroprotective efficacy against ischemia–reperfusion injury via activating the Nrf2/ARE/Keap1 pathway, offering a promising targeted therapeutic approach for ischemic stroke therapy.
Background Osteosarcoma is the third most common cancer in adolescence and the first common primary malignant tumor of bone. The long-term prognosis of osteosarcoma still remains unsatisfactory in the past decades. Therefore, development of novel therapeutic agents which are effective to osteosarcoma and are safe to normal tissue simultaneously is quite essential and urgent. Methods Firstly, MTT assay, cell colony formation assay, cell migration and invasion assays were conducted to evaluate the inhibitory effects of imperatorin towards human osteosarcoma cells. RNA-sequence assay and bioinformatic analysis were then performed to filtrate and assume the potential imperatorin-induced cell death route and signaling pathway. Moreover, quantitative real-time PCR assay, western blot assay and rescue experiments were conducted to confirm the assumptions of bioinformatic analysis. Finally, a subcutaneous tumor-transplanted nude mouse model was established and applied to evaluate the internal effect of imperatorin on osteosarcoma by HE and immunohistochemistry staining. Results Imperatorin triggered time-dependent and dose-dependent inhibition of tumor growth mainly by inducing autophagy promotion and G0/G1 phase arrest in vitro and in vivo. Besides, imperatorin treatment elevated the expression level of PTEN and p21, down-regulated the phosphorylation of AKT and mTOR. In contrast, the inhibition of PTEN using Bpv (HOpic), a potential and selective inhibitor of PTEN, concurrently rescued imperatorin-induced autophagy promotion, cell cycle arrest and inactivation of PTEN-PI3K-AKT-mTOR/p21 pathway. Conclusions This work firstly revealed that imperatorin induced autophagy and cell cycle arrest through PTEN-PI3K-AKT-mTOR/p21 signaling pathway by targeting and up-regulating PTEN in human osteosarcoma cells. Hence, imperatorin is a desirable candidate for clinical treatments of osteosarcoma.