OBJECTIVES: To investigate the neuroprotective effects of electroacupuncture (EA) preconditioning against cerebral ischemia-reperfusion injury (CIRI) mediated by gut microbiota modulation, Nrf2/HO-1 pathway activation, and ferroptosis suppression. METHODS: Adult male SD rats were divided into sham operation group, CIRI model group, and EA preconditioning group. In the latter two groups, rat models of CIRI were established by middle cerebral artery occlusion (MCAO), and in EA preconditioning group, EA was applied at Baihui (DU20) and Zusanli (ST36) for 3 days before modeling. Neurological deficits, cerebral infarction, and hippocampal pathology of the rats were evaluated using behavioral tests, TTC staining, and Nissl and HE staining, and the oxidative stress markers (MDA, ROS, and SOD), apoptosis/ferroptosis-related proteins (Bax, Bcl-2, GPX4, and SLC7A11), and changes in gut microbiota were analyzed. RESULTS: EA preconditioning significantly reduced neurological deficits, decreased infarct volume, promoted hippocampal neuronal survival, and improved structural integrity of the hippocampal neurons in MCAO rats. EA preconditioning also significantly lowered MDA and ROS and increased SOD levels, upregulated Bcl-2, GPX4, and SLC7A11 expressions, and downregulated Bax expression in the hippocampal tissue of the rats, causing also activation of Nrf2/HO-1 signaling and improvement of gut microbiota composition. CONCLUSIONS EA preconditioning alleviates CIRI in rats by suppressing ferroptosis and apoptosis, enhancing antioxidant defenses via activating Nrf2/HO-1 signaling, and regulating the gut-brain axis.
Animals ; Electroacupuncture ; NF-E2-Related Factor 2/metabolism* ; Rats, Sprague-Dawley ; Signal Transduction ; Reperfusion Injury/therapy* ; Ferroptosis ; Male ; Rats ; Brain Ischemia ; Gastrointestinal Microbiome ; Heme Oxygenase (Decyclizing)/metabolism* ; Brain/metabolism* ; Oxidative Stress ; Heme Oxygenase-1/metabolism* ; Apoptosis

OBJECTIVES: To evaluate the effect of eye acupuncture on neural function and angiogenesis of ischemic cerebral tissue in rats, and explore the roles of METTL3-mediated m⁶A methylation and the HIF-1α/VEGF-A signal axis in mediating this effect. METHODS: Fifty SD rats were randomized into normal control group, sham-operated group, model group, eye acupuncture group and DMOG (a HIF-1α agonist) group. Rat models of cerebral ischemia/reperfusion injury (CIRI) were established using a modified thread thrombus method, and the changes in neurological deficits of the rats after interventions were evaluated. TTC and Nissl staining were used to examine the changes in infarction size and neuronal injury, and cerebral angiogenesis was detected by double-immunofluorescence staining. m⁶A methylation modification level in the brain tissue was detected by ELISA, and RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of METTL3 and HIF-1α/VEGF-A. RESULTS: Compared with the control and sham-operated rats, the CIRI rats had significantly higher neurological deficit scores with larger cerebral infarction area, a greater number of CD31- and EDU-positive new vessels, higher expression levels of HIF-1α and VEGF-A, reduced number of Nissl bodies and m6A methylation level, and lowered METTL3 protein and mRNA expressions. All these changes were significantly improved by interventions with eye acupuncture after modeling or intraperitoneal injections of DMOG for 7 consecutive days prior to modeling, and the effects of the two interventions were similar. CONCLUSIONS Eye acupuncture can improve neurological deficits in CIRI rat models possibly by promoting cortical angiogenesis via upregulating METTL3-mediated m⁶A methylation and regulating the HIF-1α/VEGF-A signal axis.
Animals ; Rats, Sprague-Dawley ; Methyltransferases/metabolism* ; Reperfusion Injury/physiopathology* ; Methylation ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Rats ; Vascular Endothelial Growth Factor A/metabolism* ; Brain Ischemia/metabolism* ; Acupuncture Therapy ; Male ; Up-Regulation ; Neovascularization, Physiologic ; Angiogenesis ; Adenosine/analogs & derivatives*

OBJECTIVE: To observe the neuroprotective effect of 6-shogaol (6-SH) in global cerebral ischemia/reperfusion injury (CIRI) following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in rats. METHODS: Computer-aided molecular docking was used to determine whether 6-SH could spontaneously bind to death-associated protein kinase 1 (DAPK1). SPF-grade male SD rats were randomly divided into a sham group (n = 5), a CPR group (n = 7), and a CPR+6-SH group (n = 7). The CPR group and CPR+6-SH group were further divided into 12-, 24-, and 48-hour subgroups based on observation time points. A rat model of global CIRI after CA-CPR was established by asphyxiation. In the sham group, only tracheal and vascular intubation was performed without asphyxia and CPR induction. The CPR group was intraperitoneally injected with 1 mL of normal saline immediately after successful modeling. The CPR+6-SH group received an intraperitoneal injection of 20 mg/kg 6-SH (1 mL) immediately after successful modeling, followed by administration every 12 hours until the endpoint. Neurological Deficit Score (NDS) was recorded at each time point after modeling. After completion of observation at each time point, rats were anesthetized and sacrificed, and brain tissue specimens were collected. Histopathological changes of neurons were observed under light microscopy after hematoxylin-eosin (HE) staining. Ultrastructural changes of hippocampal neurons and autophagy were observed by transmission electron microscopy (TEM). Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect mRNA expression levels of DAPK1, vacuolar protein sorting 34 (VPS34), Beclin1, and microtubule-associated protein 1 light chain 3 (LC3) in brain tissues. Western blotting was used to detect protein expression levels of DAPK1, phosphorylated DAPK1 at serine 308 (p-DAPK1 ser308), VPS34, Beclin1, and LC3. Immunofluorescence was used to observe Beclin1 and LC3 expression in brain tissues under a fluorescence microscope. RESULTS: Molecular docking results indicated that 6-SH could spontaneously bind to DAPK1. Compared with the sham group, the NDS scores of the CPR group rats were significantly increased at all modeling time points; under light microscopy, disordered cell arrangement, widened intercellular spaces, and edema were observed in brain tissues, with pyknotic and necrotic nuclei in some areas; under TEM, mitochondria were markedly swollen with intact membranes, dissolved matrix, reduced or disappeared cristae, vacuolization, and increased autophagosomes. Compared with the CPR group, the NDS scores of the CPR+6-SH group rats were significantly decreased at all modeling time points; under light microscopy, local neuronal edema and widened perinuclear space were observed; under TEM, mitochondria were mostly mildly swollen with intact membranes, fewer autophagosomes, and alleviated injury. RT-qPCR results showed that compared with the sham group, mRNA expression levels of DAPK1, VPS34, Beclin1, and LC3 in brain tissues were significantly upregulated in all CPR subgroups, with the most pronounced changes at 24 hours. Compared with the CPR group, the CPR+6-SH group showed significantly lower mRNA expression of the above indicators at each time point [24 hours post-modeling (relative expression): DAPK1 mRNA: 3.41±0.68 vs. 4.48±0.62; VPS34 mRNA: 3.63±0.49 vs. 4.66±1.18; Beclin1 mRNA: 3.08±0.49 vs. 4.04±0.22; LC3 mRNA: 2.60±0.36 vs. 3.67±0.62; all P < 0.05]. Western blotting results showed that compared with the sham group, the protein expression levels of DAPK1, VPS34, Beclin1, and LC3 in all CPR subgroups were significantly increased, while the expression of p-DAPK1 ser308 was significantly decreased, with the most pronounced changes observed in the CPR 24-hour subgroup. Compared with the CPR group, the CPR+6-SH subgroups exhibited significantly reduced protein expression of DAPK1, VPS34, Beclin1, and LC3 [24-hour post-modeling: DAPK1/β-actin: 1.88±0.22 vs. 2.47±0.22; VPS34/β-actin: 2.55±0.06 vs. 3.46±0.05; Beclin1/β-actin: 2.12±0.03 vs. 2.87±0.03; LC3/β-actin: 2.03±0.24 vs. 3.17±0.23; all P < 0.05]. Conversely, the expression of p-DAPK1 ser308 was significantly upregulated in the CPR+6-SH group compared to the CPR group [24-hour post-modeling: p-DAPK1 ser308/β-actin: 0.40±0.02 vs. 0.20±0.07, P < 0.05]. Under the fluorescence microscope, fluorescence intensities of Beclin1 and LC3 in the CPR 24-hour group were significantly higher than those in the sham 24-hour group; compared with the CPR 24-hour group, the CPR+6-SH 24-hour group showed significantly reduced fluorescence intensities of Beclin1 and LC3. CONCLUSION 6-SH inhibited the expression of DAPK1, alleviated excessive autophagy after global CIRI following CA-CPR in rats, and exerted neuroprotective effects. The mechanism may be related to phosphorylation at the DAPK1 ser308 site.
Animals ; Rats, Sprague-Dawley ; Male ; Rats ; Cardiopulmonary Resuscitation ; Autophagy/drug effects* ; Heart Arrest/therapy* ; Death-Associated Protein Kinases/metabolism* ; Reperfusion Injury/metabolism* ; Disease Models, Animal ; Neuroprotective Agents/pharmacology* ; Brain Ischemia/metabolism*

OBJECTIVES: To investigate the effect of in vitro cultured calculus bovis (ICCB) on cerebral ischemia/reperfusion injury (CIRI) and its mechanism. METHODS: A CIRI rat model and a cell model were induced by middle cerebral artery occlusion (MCAO) in Sprague Dawley rats and oxygen glucose deprivation/reperfusion (OGD/R) in BV2 cells, respectively. The CIRI rat model was evaluated using the modified neurological severity score (mNSS), brain water content, and cerebral infarction volume after 1.5 h of ischemia followed by 72 h of reperfusion. Histopathological changes in the cortex and hippocampal CA1 region were observed with hematoxylin and eosin staining. Microglial polarization and NOD-like receptor thermal protein domain associated protein (NLRP) 3 inflammasome expression in the cortex were examined by immunofluorescence. BV2 cell viability was measured via MTT assay after treatment with ICCB and Nigericin. The expressions of NLRP3, ASC, caspase-1 proteins and inflammatory cytokines were detected with Western blotting in OGD/R treated BV2 cells (0.5 h OGD+24 h reperfusion) and in cells pretreated with Nigericin for 24 h. RESULTS: ICCB treatment significantly improved neurological function, reduced cerebral infarct volume and brain water content, and mitigated pathological damage in the cortical and hippocampal CA1 regions of rats subjected to CIRI (all P<0.05). ICCB promoted the transition of cortical microglia from M1 to M2 phenotypes and suppressed NLRP3 activation in microglial cells (all P<0.01). ICCB significantly down-regulated the expression of NLRP3, ASC, and caspase-1 proteins, and reduced the secretion of IL-18 and IL-1β in BV2 cells of OGD/R model (all P<0.01). In addition, Nigericin significantly reversed the salvage effect of ICCB on model cells (both P<0.01) and the modulation of inflammatory cytokines (P<0.05). CONCLUSIONS ICCB exerts a protective effect against CIRI by mitigating neuroinflammation, through the reduction of M1 microglial polarization, promotion of M2 conversion, and suppression of the NLRP3/ASC/caspase-1 signaling pathway.
Animals ; Rats, Sprague-Dawley ; Reperfusion Injury/prevention & control* ; Microglia/metabolism* ; Rats ; NLR Family, Pyrin Domain-Containing 3 Protein ; Brain Ischemia/metabolism* ; Male

Traumatic brain injury (TBI), as a significant central nervous system damage disease with high frequency in the world, leads to a huge number of patients with impaired health and lower quality of life every year. Lung injury is a common and dangerous consequence, which dramatically raises the mortality of patients. Discovering the pathophysiology of lung injury after TBI and discovering viable therapeutic targets has become an important need for clinical diagnosis and therapy. Neurotransmitters, as the fundamental chemical agents of the nervous system for signal transmission, not only govern neuronal activity and apoptosis in TBI but also significantly influence the pathophysiological mechanisms of lung injury subsequent to TBI. The imbalance is intricately linked to the onset and progression of lung damage. This paper systematically reviews the clinical characteristics and predominant pathogenesis of lung injury following TBI, emphasizing the role of key neurotransmitters, including glutamate (Glu), γ-aminobutyric acid (GABA), norepinephrine (NE), dopamine (DA), and acetylcholine (ACh), in lung injury post-TBI. It examines their influence on inflammatory response, vascular permeability, and pulmonary circulation function. Additionally, the paper evaluates the research advancements and potential applications of targeted therapeutic strategies for various neurotransmitter systems, such as receptor antagonists, transporter inhibitors, and neurotransmitter analogues. This research aims to offer a theoretical framework for clarifying the neural regulatory mechanisms of lung injury following TBI and to establish a basis for the development of novel therapeutic strategies and enhancement of the prognosis of the patients.
Humans ; Brain Injuries, Traumatic/metabolism* ; Neurotransmitter Agents/metabolism* ; Lung Injury/metabolism* ; gamma-Aminobutyric Acid/metabolism* ; Glutamic Acid/metabolism* ; Norepinephrine/metabolism* ; Dopamine/metabolism* ; Acetylcholine/metabolism*

Aralia taibaiensi, widely distributed in western China, particularly in the Qinba Mountains, has been utilized as a folk medicine for treating diabetes, gastropathy, rheumatism, and cardiovascular diseases. Saponins from A. taibaiensis (sAT) have demonstrated protective effects against oxidative stress and mitochondrial dysfunction induced by ischemia/reperfusion (I/R). However, the underlying mechanisms remain unclear. In vivo, middle cerebral artery occlusion/reperfusion (MCAO/R) induced inflammatory infiltration, neuronal injury, cell apoptosis, mitochondrial dysfunction, and oxidative stress in the ischaemic penumbra, which were effectively mitigated by sAT. sAT increased the mRNA and protein expression levels of apelin and its receptor apelin/apelin receptors (ARs) both in vivo and in vitro. (Ala13)-Apelin-13 (F13A) and small interfering RNA (siRNA) abolished the regulatory effects of sAT on neuroprotection mediated by adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/protein kinase B (Akt). Furthermore, sAT induced apelin/AR expression by simultaneously inhibiting P38 mitogen-activated protein kinase (P38 MAPK)/activating transcription factor 4 (ATF4) and upregulating hypoxia-inducible factor-1α (HIF-1α). Our findings indicate that sAT regulates apelin/AR/AMPK by inhibiting P38 MAPK/ATF4 and upregulating HIF-1a, thereby suppressing oxidative stress and mitochondrial dysfunction.
Animals ; Reperfusion Injury/prevention & control* ; Aralia/chemistry* ; Saponins/administration & dosage* ; AMP-Activated Protein Kinases/genetics* ; Male ; Apelin/genetics* ; Signal Transduction/drug effects* ; Neuroprotective Agents/administration & dosage* ; Brain Ischemia/genetics* ; Rats, Sprague-Dawley ; Rats ; Oxidative Stress/drug effects* ; Apelin Receptors/genetics* ; Humans ; Apoptosis/drug effects* ; Mice

OBJECTIVE: To observe the effects of Xingnao Kaiqiao acupuncture technique (for regaining consciousness and opening orifice) on methylation of N6-methyladenosine (m6A), and key methyltransferases and demethylases, so as to clarify the mechanism of acupuncture on cerebral ischemia-reperfusion injury (CIRI). METHODS: Of 68 male Sprague-Dawley rats of SPF grade, 15 rats were randomly selected as a sham-operation group, and the remaining rats were subjected to the model of middle cerebral artery occlusion using the suture ligation. CIRI was induced by ischemia for 2 h followed by reperfusion. Rats that failed to modeling or died were excluded. The rest 45 rats were randomly divided into three groups, i.e. model group, acupuncture group, and non-point acupuncture group, with 15 rats in each group. The rats in the acupuncture group were treated with acupuncture at bilateral "Neiguan" (PC6) and "Shuigou" (GV26). In the non-point acupuncture group, acupuncture was delivered at three non-points, located 3 mm below the bilateral midaxillary line and 3 mm lateral to the tip of the coccyx. One intervention was operated in these two acupuncture groups and the needles were retained for 30 min. Before modeling start and 2 h after ischemia, a laser speckle flowmeter was used to monitor the cerebral blood perfusion. In 2 h of ischemia and 24 h of reperfusion, the neurological behavioral score was evaluated. The volume of rat cerebral infarction was determined by triphenyltetrazolium chloride (TTC) staining, and the level of m6A methylation in ischemic cortical area was detected by Dot blot, and the protein and mRNA expression of the demethylase i.e. fat mass and obesity-associated protein (FTO), AlkB homolog 5 (ALKBH5) and key methyltransferases, i.e. methyltransferase-like 3 (METTL3), methyltransferase-like 14 (METTL14), and Wilms' tumor 1-associated protein (WTAP) in ischemic cortical area were detected by Western blot and real-time PCR. RESULTS: Cerebral blood perfusion decreased by>70% after 2 h ischemia. Compared with the sham-operation group, the neurobehavioral score and the percentage of cerebral infarction volume increased in the model group (P<0.01); the level of m6A methylation in the ischemic cortical area increased (P<0.01), the protein and mRNA expression of FTO decreased (P<0.01), and that of ALKBH5, METTL3, and METTL14 increased (P<0.01, P<0.05) in the model group. When compared with the model group and the non-point acupuncture group, the acupuncture group showed a decrease in the neurobehavioral score and the percentage of cerebral infarction volume (P<0.01), the level of m6A methylation in the ischemic cortical area was reduced (P<0.01, P<0.05), and the protein and mRNA expression of FTO was elevated (P<0.01). CONCLUSION Xingnao Kaiqiao acupuncture technique presents its protective effect on the brain in the rats with CIRI, which is related to up-regulating the expression of FTO and modulating m6A methylation.
Animals ; Rats, Sprague-Dawley ; Male ; Acupuncture Therapy ; Reperfusion Injury/genetics* ; Rats ; Brain Ischemia/genetics* ; Humans ; Adenosine/metabolism* ; Methylation ; Acupuncture Points ; Cerebral Cortex/metabolism*

OBJECTIVE: To explore the neuroprotective effect and underlying mechanism of Xingnao Kaiqiao acupuncture (acupuncture for regaining consciousness and opening orifices) in the rat models of cerebral ischemia-reperfusion injury (CIRI) based on the p53 protein (p53)/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling pathway. METHODS: Of 102 male Wistar rats, 20 rats were randomly collected as a sham-operation group. Using a modified external carotid artery filament insertion method, CIRI models were prepared by occluding the middle cerebral artery in the rest rats. After modeling and excluding 1 non-successfully modeled rat and 1 dead one, the other modeled rats were randomized into a model group, an agonist group, an acupuncture group, and an acupuncture + agonist group, 20 rats in each one. Xingnao Kaiqiao acupuncture therapy was delivered in the rats of the acupuncture group and the acupuncture + agonist group. The acupoints included "Shuigou" (GV26), bilateral "Neiguan" (PC6), and "Sanyinjiao" (SP6) on the affected side. Electroacupuncture was attached to "Neiguan" (PC6) and "Sanyinjiao" (SP6) on the affected side, with dense-disperse wave, a frequency of 2 Hz/15 Hz and intensity of 1 mA. The intervention was delivered twice daily, 20 min each time and for 7 consecutive days. In the agonist group and acupuncture+agonist group, p53 agonist, COTI-2 was intraperitoneally injected (15 mg/kg), once daily for 7 consecutive days. Neurological deficit was evaluated using Zausinger's six-point scale. Cerebral infarction volume was quantified by triphenyl tetrazolium chloride (TTC) staining. Histopathological changes were observed using hematoxylin-eosin (HE) staining. Iron deposition was assessed by Prussian blue staining. Mitochondrial ultrastructure in the ischemic cortex was examined under transmission electron microscopy (TEM). Serum iron (Fe²⁺) was measured with chromometry. Malondialdehyde (MDA) and glutathione (GSH) levels in the ischemic hippocampus were determined using thiobarbituric acid and microplate assays, respectively. The mean fluorescence intensity of reactive oxygen species (ROS) in the ischemic cortex was analyzed by flow cytometry. The mRNA and protein expression of GPX4, SLC7A11, and p53 in the ischemic hippocampus were evaluated using quantitative real-time PCR (qRT-PCR) and Western blotting, respectively. RESULTS: Compared with the sham-operated group, the model group exhibited the decrease in neurological deficit score (P<0.01), and the increase in cerebral infarction volume percentage (P<0.01). The changes of brain tissue were presented in extensive cellular necrosis, pyknotic and deeply-stained nuclei, and vacuolar degeneration. The iron deposition was elevated in cortex and hippocampus (P<0.01), mitochondrial membrane density increased, the cristae was broken or reduced, and the outer membrane ruptured. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were elevated (P<0.01) and the level of GSH was reduced (P<0.01). The mRNA and protein expression of GPX4 and SLC7A11 was reduced (P<0.01), while that of p53 rose (P<0.01). When compared with the model group, in the agonist group, the neurological deficit score was reduced (P<0.05), the percentage of infarction volume was higher (P<0.01), the histopathological damage was further exacerbated, and the percentage of iron deposition increased in the cortex and hippocampus (P<0.01). The mitochondrial quantity decreased, the membrane density increased, the mitochondrial cristae were broken or reduced, and the outer membrane was ruptured. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were higher (P<0.01, P<0.05) and the level of GSH was reduced (P<0.05). The mRNA and protein expression of GPX4 and SLC7A11 decreased (P<0.01, P<0.05), while that of p53 was elevated (P<0.01). Besides, in comparison with the model group, the neurological deficit score was higher in the acupuncture group and the acupuncture + agonist group (P<0.01, P<0.05), the percentage of cerebral infarction volume was lower in the acupuncture group (P<0.01), the pathological damage of brain tissue was alleviated in the acupuncture group and the acupuncture + agonist group, and the percentage of iron depositiondecreased in the cortex and hippocampus (P<0.01). The mitochondrial structure was relatively clear, the mitochondrial cristae were fractured or reduced mildly in the acupuncture group and the acupuncture + agonist group. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were lower (P<0.01) and the level of GSH was higher (P<0.01) in the acupuncture group. The mean fluorescence intensity of ROS were dropped (P<0.01) in the acupuncture + agonist group. The mRNA expression of GPX4 and SLC7A11 was elevated (P<0.01) and that of p53 was reduced (P<0.01, P<0.05) in either the acupuncture group or the acupuncture + agonist group; the protein expression of GPX4 and SLC7A11 rose (P<0.05, P<0.01) and that of p53 was dropped (P<0.01) in the acupuncture group; and the protein expression of p53 was also lower in the acupuncture + agonist group (P<0.05). When compared with the agonist group, in the acupuncture + agonist group, neurological deficit score increased (P<0.01), the percentage of cerebral infarction volume decreased (P<0.01), the pathological brain tissue damage was reduced, the percentage of iron deposition in cortex and hippocampus decreased (P<0.01), the mitochondrial structure was relatively clear and the cristae broken or reduced slightly; the levels of Fe²⁺ and MDA, as well as the mean fluorescence intensity of ROS were dropped (P<0.01), while the level of GSH increased (P<0.05); the mRNA and protein expression of GPX4 and SLC7411 was elevated (P<0.01, P<0.05), and that of p53 reduced (P<0.01). In comparison with the acupuncture + agonist group, in the acupuncture group, the neurological deficit score increased (P<0.05), the percentage of cerebral infarction volume decreased (P<0.05), the pathological brain tissue damage was alleviated, the percentage of iron deposition in cortex and hippocampus decreased (P<0.01), the mitochondrial structure was normal in tendency; the levels of Fe²⁺ and MDA, as well as the mean fluorescence intensity of ROS were reduced (P<0.05), while the level of GSH rose (P<0.01); the mRNA and protein expression of GPX4 and SLC7411 was elevated (P<0.01, P<0.05), and that of p53 reduced (P<0.01, P<0.05). CONCLUSION Xingnao Kaiqiao acupuncture can alleviate neurological damage in CIRI rats, which is obtained probably by inhibiting ferroptosis through p53/SLC7A11/GPX4 pathway.
Animals ; Reperfusion Injury/metabolism* ; Male ; Acupuncture Therapy ; Rats ; Tumor Suppressor Protein p53/genetics* ; Brain Ischemia/metabolism* ; Rats, Wistar ; Signal Transduction ; Humans ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Disease Models, Animal ; Acupuncture Points ; Amino Acid Transport System y+/genetics*

This study aims to investigate the protective effects and mechanisms of polysaccharide extract PCP1 from Polygonatum cyrtonema in ameliorating cerebral ischemia-reperfusion(I/R) injury in rats through modulation of the Toll-like receptor 4(TLR4)/NOD-like receptor protein 3(NLRP3) signaling pathway. In vivo, SD rats were randomly divided into the sham group, model group, PCP1 group, nimodipine(NMDP) group, and TLR4 signaling inhibitor(TAK-242) group. A middle cerebral artery occlusion/reperfusion(MCAO/R) model was established, and neurological deficit scores and infarct size were evaluated 24 hours after reperfusion. Hematoxylin-eosin(HE) and Nissl staining were used to observe pathological changes in ischemic brain tissue. Transmission electron microscopy(TEM) assessed ultrastructural damage in cortical neurons. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of interleukin-1β(IL-1β), interleukin-6(IL-6), interleukin-18(IL-18), tumor necrosis factor-α(TNF-α), interleukin-10(IL-10), and nitric oxide(NO) in serum. Immunofluorescence was used to analyze the expression of TLR4 and NLRP3 proteins. In vitro, a BV2 microglial cell oxygen-glucose deprivation/reperfusion(OGD/R) model was established, and cells were divided into the control, OGD/R, PCP1, TAK-242, and PCP1 + TLR4 activator lipopolysaccharide(LPS) groups. The CCK-8 assay evaluated BV2 cell viability, and ELISA determined NO release. Western blot was used to analyze the expression of TLR4, NLRP3, and downstream pathway-related proteins. The results indicated that, compared with the model group, PCP1 significantly reduced neurological deficit scores, infarct size, ischemic tissue pathology, cortical cell damage, and the levels of inflammatory factors IL-1β, IL-6, IL-18, TNF-α, and NO(P<0.01). It also elevated IL-10 levels(P<0.01) and decreased the expression of TLR4 and NLRP3 proteins(P<0.05, P<0.01). Moreover, in vitro results showed that, compared with the OGD/R group, PCP1 significantly improved BV2 cell viability(P<0.05, P<0.01), reduced cell NO levels induced by OGD/R(P<0.01), and inhibited the expression of TLR4-related inflammatory pathway proteins, including TLR4, myeloid differentiation factor 88(MyD88), tumor necrosis factor receptor-associated factor 6(TRAF6), phosphorylated nuclear factor-kappaB dimer RelA(p-p65)/nuclear factor-kappaB dimer RelA(p65), NLRP3, cleaved-caspase-1, apoptosis-associated speck-like protein(ASC), GSDMD-N, IL-1β, and IL-18(P<0.05, P<0.01). The protective effects of PCP1 were reversed by LPS stimulation. In conclusion, PCP1 ameliorates cerebral I/R injury by modulating the TLR4/NLRP3 signaling pathway, exerting anti-inflammatory and anti-pyroptotic effects.
Animals ; Toll-Like Receptor 4/genetics* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Rats, Sprague-Dawley ; Rats ; Reperfusion Injury/genetics* ; Male ; Signal Transduction/drug effects* ; Polysaccharides/isolation & purification* ; Polygonatum/chemistry* ; Brain Ischemia/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Humans

This study aims to investigate the molecular mechanism by which naringin alleviates cerebral ischemia/reperfusion(CI/R) injury through DRP1/LRRK2/MCU signaling axis. A total of 60 SD rats were randomly divided into the sham group, the model group, the sodium Danshensu group, and low-, medium-, and high-dose(50, 100, and 200 mg·kg~(-1)) naringin groups, with 10 rats in each group. Except for the sham group, a transient middle cerebral artery occlusion/reperfusion(tMCAO/R) model was established in SD rats using the suture method. Longa 5-point scale was used to assess neurological deficits. 2,3,5-Triphenyl tetrazolium chloride(TTC) staining was used to detect the volume percentage of cerebral infarction in rats. Hematoxylin-eosin(HE) staining and Nissl staining were employed to assess neuronal structural alterations and the number of Nissl bodies in cortex, respectively. Western blot was used to determine the protein expression levels of B-cell lymphoma-2 gene(Bcl-2), Bcl-2-associated X protein(Bax), cleaved cysteine-aspartate protease-3(cleaved caspase-3), mitochondrial calcium uniporter(MCU), microtubule-associated protein 1 light chain 3(LC3), and P62. Mitochondrial structure and autophagy in cortical neurons were observed by transmission electron microscopy. Immunofluorescence assay was used to quantify the fluorescence intensities of MCU and mitochondrial calcium ion, as well as the co-localization of dynamin-related protein 1(DRP1) with leucine-rich repeat kinase 2(LRRK2) and translocase of outer mitochondrial membrane 20(TOMM20) with LC3 in cortical mitochondria. The results showed that compared with the model group, naringin significantly decreased the volume percentage of cerebral infarction and neurological deficit score in tMCAO/R rats, alleviated the structural damage and Nissl body loss of cortical neurons in tMCAO/R rats, inhibited autophagosomes in cortical neurons, and increased the average diameter of cortical mitochondria. The Western blot results showed that compared to the sham group, the model group exhibited increased levels of cleaved caspase-3, Bax, MCU, and the LC3Ⅱ/LC3Ⅰ ratio in the cortex and reduced protein levels of Bcl-2 and P62. However, naringin down-regulated the protein expression of cleaved caspase-3, Bax, MCU and the ratio of LC3Ⅱ/LC3Ⅰ ratio and up-regulated the expression of Bcl-2 and P62 proteins in cortical area. In addition, immunofluorescence analysis showed that compared with the model group, naringin and positive drug treatments significantly decreased the fluorescence intensities of MCU and mitochondrial calcium ion. Meanwhile, the co-localization of DRP1 with LRRK2 and TOMM20 with LC3 in cortical mitochondria was also decreased significantly after the intervention. These findings suggest that naringin can alleviate cortical neuronal damage in tMCAO/R rats by inhibiting DRP1/LRRK2/MCU-mediated mitochondrial fragmentation and the resultant excessive mitophagy.
Animals ; Rats, Sprague-Dawley ; Reperfusion Injury/genetics* ; Flavanones/administration & dosage* ; Rats ; Dynamins/genetics* ; Male ; Brain Ischemia/genetics* ; Protein Serine-Threonine Kinases/genetics* ; Signal Transduction/drug effects* ; Humans ; Drugs, Chinese Herbal/administration & dosage*