DL-3-n-butylphthalide alleviates motor disturbance by suppressing ferroptosis in a rat model of Parkinson’s disease

DL-3-n-butylphthalide(NBP)-a compound isolated from Apium graveolens seeds-is protective against brain ischemia via various mechanisms in humans and has been approved for treatment of acute ischemic stroke.NBP has shown recent potential as a treatment for Parkinson’s disease.However,the underlying mechanism of action of NBP remains poorly understood.In this study,we established a rat model of Parkinson’s disease by intraperitoneal injection of rotenone for 28 successive days,followed by intragastric injection of NBP for 14-28 days.We found that NBP greatly alleviated rotenone-induced motor disturbance in the rat model of Parkinson’s disease,inhibited loss of dopaminergic neurons and aggregation ofα-synuclein,and reduced iron deposition in the substantia nigra and iron content in serum.These changes were achieved by alterations in the expression of the iron metabolism-related proteins transferrin receptor,ferritin light chain,and transferrin 1.NBP also inhibited oxidative stress in the substantia nigra and protected mitochondria in the rat model of Parkinson’s disease.Our findings suggest that NBP alleviates motor disturbance by inhibition of iron deposition,oxidative stress,and ferroptosis in the substantia nigra.

Integrated analysis reveals the protective mechanism and therapeutic potential of hyperbaric oxygen against pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a dreadful, chronic, and irreversibly progressive disease leading to death with a few effective treatments. Our previous study suggested that repetitive hyperbaric oxygen (HBO) treatment alleviates bleomycin-induced pulmonary fibrosis in mice. Here, we investigated the protective mechanism of HBO treatment against pulmonary fibrosis using an integrated approach. Analyzing publicly available expression data from the mouse model of bleomycin-induced pulmonary fibrosis as well as IPF patients, several potential mechanisms of relevance to IPF pathology were identified, including increased epithelial-to-mesenchymal transition (EMT) and glycolysis. High EMT or glycolysis scores in bronchoalveolar lavage were strong independent predictors of mortality in multivariate analysis. These processes were potentially driven by hypoxia and blocked by HBO treatment. Together, these data support HBO treatment as a viable strategy against pulmonary fibrosis.

Testosterone attenuates pulmonary epithelial inflammation in male rats of COPD model through preventing NRF1-derived NF-κB signaling

Testosterone deficiency is common in male patients with chronic obstructive pulmonary disease (COPD) and may correlate with the deterioration of COPD. Clinical research suggests that testosterone replacement therapy may slow the COPD progression, but the specific biological pathway remains unclear. In this study, we explored the effect of testosterone on pulmonary inflammation in male COPD rats. The animals were co-treated with lipopolysaccharide (LPS) and cigarette to induce COPD. In COPD rats, nuclear respiratory factor 1 (NRF1) and NF-κB p65 were upregulated. In cigarette smoke extract (CSE)-, LPS-, or the combination of CSE and LPS-treated L132 cells, NRF1 and p65 were also upregulated. Silencing NRF1 resulted in the downregulation of p65. ChIP‒seq, ChIP‒qPCR, and luciferase results showed that NRF1 transcriptionally regulated p65. Both male and female COPD rats showed an upregulated NRF1 level and similar pulmonary morphology. But NRF1 was further upregulated in male castrated rats. Further supplementing testosterone in castrated male rats significantly reduced NRF1, pulmonary lesions, and inflammation. Supplementation of testosterone also reduced the phosphorylation of p65 and IKKβ induced by LPS or CSE in L132 cells. Our results suggest that testosterone plays a protective role in pulmonary epithelial inflammation of COPD through inhibition of NRF1-derived NF-κB signaling and the phosphorylation of p65.

Increased CXCL13 and CXCR5 in Anterior Cingulate Cortex Contributes to Neuropathic Pain-Related Conditioned Place Aversion

Pain consists of sensory-discriminative and emotional-affective components.The anterior cingulate cortex(ACC)is a critical brain area in mediating the affective pain.However,the molecular mechanisms involved remain largely unknown.Our recent study indicated that C-X-C motif chemokine 13(CXCL13)and its sole receptor CXCR5 are involved in sensory sensitization in the spinal cord after spinal nerve ligation(SNL).Whether CXCL13/CXCR5 signaling in the ACC contributes to the pathogenesis of pain-related aversion remains unknown.Here,we showed that SNL increased the CXCL13 level and CXCR5 expression in the ACC after SNL.Knockdown of CXCR5 by microinjection of Cxcr5 shRNA into the ACC did not affect SNL-induced mechanical allodynia but effectively alleviated neuropathic painrelated place avoidance behavior.Furthermore,electrophysiological recording from layer Ⅱ-Ⅲ neurons in the ACC showed that SNL increased the frequency and amplitude of spontaneous excitatory postsynaptic currents(sEPSCs),decreased the EPSC paired-pulse ratio,and increased the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor/N-methyl-D-aspartate receptor ratio,indicating enhanced glutamatergic synaptic transmission.Finally,superfusion of CXCL13 onto ACC slices increased the frequency and amplitude of spontaneous EPSCs.Pre-injection of Cxcr5 shRNA into the ACC reduced the increase in glutamatergic synaptic transmis sion induced by SNL.Collectively,these results suggest that CXCL13/CXCR5 signaling in the ACC is involved in neuropathic pain-related aversion via synaptic potentiation.

NRF1-mediated microglial activation triggers high-altitude cerebral edema

High-altitude cerebral edema(HACE)is a potentially fatal encephalopathy associated with a time-dependent exposure to the hypobaric hypoxia of altitude.The formation of HACE is affected by both vasogenic and cytotoxic edema.The over-activated microglia potentiate the damage of blood-brain barrier(BBB)and exacerbate cytotoxic edema.In light with the activation of microglia in HACE,we aimed to investigate whether the over-activated microglia were the key turning point of acute mountain sickness to HACE.In in vivo experiments,by exposing mice to hypobaric hypoxia(7000 m above sea level)to induce HACE model,we found that microglia were activated and migrated to blood vessels.Microglia depletion by PLX5622 obviously relieved brain edema.In in vitro experiments,we found that hypoxia induced cultured microglial activation,leading to the destruction of endothelial tight junction and astrocyte swelling.Up-regulated nuclear respiratory factor 1(NRF1)accelerated pro-inflammatory factors through transcriptional regulation on nuclearfactorkappa B p65(NF-kB p65)and mitochondrial transcription factorA(TFAM)in activated microglia under hypoxia.NRF1 also up-regulated phagocytosis by transcriptional regulation on caveolin-1(CAV-1)and adaptorrelated protein complex 2 subunit beta(AP2B1).The present study reveals a new mechanism in HACE:hypoxia over-activates microglia through up-regulation of NRF1,which both induces inflammatory response through transcriptionally activating NF-kB p65 and TFAM,and enhances phagocytic function through up-regulation of CAV-1 and AP2B1;hypoxia-activatedmicroglia destroy the integrity of BBB and release pro-inflammatory factors that eventually induce HACE.

Argon mitigates post-stroke neuroinflammation by regulating M1/M2 polarization and inhibiting NF-κB/NLRP3 inflammasome signaling

Neuroinflammation plays a vital role in cerebral ischemic stroke(IS).In the acute phase of IS,microglia are activated toward the pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.Argon,an inert gas,can reduce neuroinflammation and alleviate ischemia/reperfusion(I/R)injury.However,whether argon regulates M1/M2 polarization to protect against I/R injury as well as the underlying mechanism has not been reported.In this study,we analyzed the activation and polarization of microglia after I/R injury with or without argon administration and explored the effects of argon on NLRP3 inflammasome-mediated inflammation in microglia in vitro and in vivo.The results showed that argon application inhibited the activation of M1 microglia/macrophage in the ischemic penumbra and the expression of proteins related to NLRP3 inflammasome and pyroptosis in microglia.Argon administration also inhibited the expression and processing of IL-1β,a primary pro-inflammatory cytokine.Thus,argon alleviates I/R injury by inhibiting pro-inflammatory reactions via suppressing microglial polarization toward M1 phenotype and inhibiting the NF-κB/NLRP3 inflammasome signaling pathway.More importantly,we showed that argon worked better than the specific NLRP3 inflammasome inhibitor MCC950 in suppressing neuroinflammation and protecting against cerebral I/R injury,suggesting the therapeutic potential of argon in neuroinflammation-related neurodegeneration diseases as a potent gas inhibitor of the NLRP3 inflammasome signaling pathway.