Hyperbaric Oxygen Reduces Oxidative Stress Impairment and DNA Damage and Simultaneously Increases HIF-1α in Ischemia-Reperfusion Acute Kidney Injury.

The central exacerbating factor in the pathophysiology of ischemic-reperfusion acute kidney injury (AKI) is oxidative stress. Lipid peroxidation and DNA damage in ischemia are accompanied by the formation of 3-nitrotyrosine, a biomarker for oxidative damage. DNA double-strand breaks (DSBs) may also be a result of postischemic AKI. γH2AX(S139) histone has been identified as a potentially useful biomarker of DNA DSBs. On the other hand, hypoxia-inducible factor (HIF) is the "master switch" for hypoxic adaptation in cells and tissues. The aim of this research was to evaluate the influence of hyperbaric oxygen (HBO) preconditioning on antioxidant capacity estimated by FRAP (ferric reducing antioxidant power) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay, as well as on oxidative stress parameter 3-nitrotyrosine, and to assess its effects on γH2AX(S139), HIF-1α, and nuclear factor-κB (NF-κB) expression, in an experimental model of postischemic AKI induced in spontaneously hypertensive rats. The animals were divided randomly into three experimental groups: sham-operated rats (SHAM, n = 6), rats with induced postischemic AKI (AKI, n = 6), and group exposed to HBO preconditioning before AKI induction (AKI + HBO, n = 6). A significant improvement in the estimated glomerular filtration rate, eGFR, in AKI + HBO group (p < 0.05 vs. AKI group) was accompanied with a significant increase in plasma antioxidant capacity estimated by FRAP (p < 0.05 vs. SHAM group) and a reduced immunohistochemical expression of 3-nitrotyrosine and γH2AX(S139). Also, HBO pretreatment significantly increased HIF-1α expression (p < 0.001 vs. AKI group), estimated by Western blot and immunohistochemical analysis in kidney tissue, and decreased immunohistochemical NF-κB renal expression (p < 0.01). Taking all of these results together, we may conclude that HBO preconditioning has beneficial effects on acute kidney injury induced in spontaneously hypertensive rats.

Effects of RBT-1 on preconditioning response biomarkers in patients undergoing coronary artery bypass graft or heart valve surgery: a multicentre, double-blind, randomised, placebo-controlled phase 2 trial.

Background: RBT-1 is a combination drug of stannic protoporfin (SnPP) and iron sucrose (FeS) that elicits a preconditioning response through activation of antioxidant, anti-inflammatory, and iron-scavenging pathways, as measured by heme oxygenase-1 (HO-1), interleukin-10 (IL-10), and ferritin, respectively. Our primary aim was to determine whether RBT-1 administered before surgery would safely and effectively elicit a preconditioning response in patients undergoing cardiac surgery. Methods: This phase 2, double-blind, randomised, placebo-controlled, parallel-group, adaptive trial, conducted in 19 centres across the USA, Canada, and Australia, enrolled patients scheduled to undergo non-emergent coronary artery bypass graft (CABG) and/or heart valve surgery with cardiopulmonary bypass. Patients were randomised (1:1:1) to receive either a single intravenous infusion of high-dose RBT-1 (90 mg SnPP/240 mg FeS), low-dose RBT-1 (45 mg SnPP/240 mg FeS), or placebo within 24-48 h before surgery. The primary outcome was a preoperative preconditioning response, measured by a composite of plasma HO-1, IL-10, and ferritin. Safety was assessed by adverse events and laboratory parameters. Prespecified adaptive criteria permitted early stopping and enrichment. This trial is registered with ClinicalTrials.gov, NCT04564833. Findings: Between Aug 4, 2021, and Nov 9, 2022, of 135 patients who were enrolled and randomly allocated to a study group (46 high-dose, 45 low-dose, 44 placebo), 132 (98%) were included in the primary analysis (46 high-dose, 42 low-dose, 44 placebo). At interim, the trial proceeded to full enrollment without enrichment. RBT-1 led to a greater preconditioning response than did placebo at high-dose (geometric least squares mean [GLSM] ratio, 3.58; 95% CI, 2.91-4.41; p < 0.0001) and low-dose (GLSM ratio, 2.62; 95% CI, 2.11-3.24; p < 0.0001). RBT-1 was generally well tolerated by patients. The primary drug-related adverse event was dose-dependent photosensitivity, observed in 12 (26%) of 46 patients treated with high-dose RBT-1 and in six (13%) of 45 patients treated with low-dose RBT-1 (safety population). Interpretation: RBT-1 demonstrated a statistically significant cytoprotective preconditioning response and a manageable safety profile. Further research is needed. A phase 3 trial is planned. Funding: Renibus Therapeutics, Inc.

Moxibustion preconditioning reduces inflammatory response in rats with cerebral ischemia-reperfusion injury by regulating PI3K / AKT / mTOR signaling pathway. / 艾灸预处理通过调控PI3K/AKT/mTORä¿¡å·é€šè·¯å‡è½»è„‘ç¼ºè¡€å†çŒæ³¨æŸä¼¤å¤§é¼ ç‚Žæ€§ååº”.

OBJECTIVES: To observe the effect of moxibustion preconditioning on inflammatory response in rats with cerebral ischemia reperfusion injury (CIRI), so as to explore its mechanisms underlying improving CIRI. METHODS: Seventy-five male SD rats were randomly divided into sham operation, model, moxibustion preconditioning 3 days (Moxi 1), moxibustion preconditioning 5 days (Moxi 2) and moxibustion preconditioning 7 days (Moxi 3) groups, with 15 rats in each group. Moxibustion was applied at "Baihui"(GV20), "Dazhui"(GV14) and "Zusanli"(ST36) for 20 min once a day, totally for 3, 5 or 7 days. Thirty minutes after the last moxibustion treatment, the CIRI model was established by occlusion of the middle cerebral artery. The neurological deficit score was assessed by using Longa's method. The infarct size of the brain assessed after staining with 2% triphenyltetrazolium chloride (TTC). The morphological changes of cortical neurons were observed by HE staining. The contents of inflammatory factors interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), S-100ß protein (S-100ß) and neuron-specific enolase (NSE) were detected by ELISA. The expression of phosphatidylinositol-3-kinase (PI3K), p-PI3K, protein kinase B (AKT) and mammalian target of rapamycin (mTOR) proteins in the ischemic cortex tissues were detected by immunohistochemistry and Western blot. RESULTS: Compared with the sham operation group, the neurological function score and the percentage of cerebral ischemic volume were increased (P<0.01). The contents of serum IL-1ß, TNF-α, S-100ß and NSE were significantly increased (P<0.01), while the protein expressions of PI3K, p-PI3K, AKT and mTOR in the cerebral cortex were significantly decreased (P<0.01) in the model group. Compared with the model group, the neurological function score and the percentage of cerebral ischemic volume were significantly decreased (P<0.01). The contents of serum IL-1ß, TNF-α, S-100ß and NSE were significantly decreased (P<0.01), and the expressions of PI3K, p-PI3K, AKT and mTOR proteins in the cerebral cortex were significantly increased (P<0.01) in three moxibustion groups. Compared with the Moxi 1 and Moxi 2 groups, the above indicators were significantly improved in rats of the Moxi 3 group (P<0.01, P<0.05). CONCLUSIONS: Moxibustion preconditioning can significantly improve the neurological function of rats after ischemia-reperfusion, inhibit serum inflammatory factors IL-1 ß and TNF-α, inhibit brain tissue injury markers S-100ß and NSE, which may be related to the activation of PI3K/AKT/mTOR signaling pathway. The protective effect of moxibustion preconditioning for 7 days on CIRI was better than that of 5 days and 3 days.

Effects of electroacupuncture preconditioning on microglial cells and serum inflammatory factors in the early stage of ischemic stroke. / ç”µé’ˆé¢„å¤„ç†å¯¹ç¼ºè¡€æ€§ä¸­é£Žå°é¼ æ—©æœŸå°èƒ¶è´¨ç»†èƒžåŠè¡€æ¸ ç‚Žæ€§å› å­çš„å½±å“.

OBJECTIVES: To investigate the effects on the motor function, cortex blood flow perfusion, microglial cells, and the contents of serum inflammatory factors, i.e. interleukin-1ß (IL-1ß), transforming growth factor-ß (TGF-ß), and interleukin-10 (IL-10) after electroacupuncture (EA) preconditioning at "Baihui" (GV20) and "Dazhui" (GV14) in the mice with ischemic stroke, so as to explore the mechanism of EA preconditioning for improving motor function after ischemic stroke. METHODS: C57BL/6 mice were randomly divided into sham-operation group, model group, and EA preconditioning group (EA group), with 15 mice in each group. A photothrombotic method was used to induce the model of unilateral ischemic stroke and motor impairment. The mice in the EA group received EA preconditioning, 20 min each time, once daily for 7 consecutive days before modeling. The motor function of mice was evaluated by the grid-walking test and cylinder test before and after modeling. Laser speckle blood flow video monitoring system was employed to assess the cerebral blood flow perfusion in the primary motor cortex of mice. The contents of IL-1ß, TGF-ß, and IL-10 in the serum were measured by ELISA, and the expressions of microglial cell and M2 subtype cell marker in the primary motor cortex were detected using immunofluorescence staining. RESULTS: After modeling, compared with the sham-operation group, the grid error rate and the dragging rate of the affected limb were increased (P<0.01)；the utilization rate of the affected limb and percentage of the blood perfusion in the affected cortex to healthy side were decreased (P<0.01)；the contents of serum IL-1ß, TGF-ß, and IL-10 were increased (P<0.01, P<0.05)；and the microglia in the primary motor cortex on the affected side showed ameboid, the fluorescence intensity of ionized calcium-binding adapter molecule 1 (IBA1) and CD206 was increased (P<0.01) in the model group. In the EA group, when compared with the model group, the grid error rate and the dragging rate of affected limb were decreased (P<0.01)；the utilization rate of affected limb and the percentage of blood perfusion were increased (P<0.05)；the content of serum IL-1ß was decreased (P<0.01), while the contents of TGF-ß and IL-10 were increased (P<0.01)；and the microglia in the primary motor cortex on the affected side got more round and were distributed more densely, the fluorescence intensity of IBA1 and CD206 was increased (P<0.01). CONCLUSIONS: Electroacupuncture preconditioning at "GV20" and "GV14" can up-regulate the expression of microglial cells, especially the M2 subtype cell marker, and increase the contents of the anti-inflammatory factors and decrease that of the pro-inflammatory factors in the serum, thereby alleviate the inflammatory reaction.

Preconditioning with Photobiomodulation as an Effective Method in Preventing Chemotherapy-Induced Oral Mucositis: A Systematic Review.

Background: Given the suffering experienced by cancer patients, effective solutions must be found to prevent the most painful and debilitating side effects of anticancer treatment. The use of photobiomodulation (PBM) with specific parameters has been proposed to prevent oral mucositis in adults undergoing hematopoietic stem cell transplantation as well as in head and neck cancer patients receiving radiotherapy alone without chemotherapy. No recommendations were possible for patients undergoing chemotherapy alone. This systematic review aims to analyze the effectiveness of preconditioning by PBM in preventing chemotherapy-induced oral mucositis. Methods: This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PRISMA, Checklist and registered at the International Prospective Register of Systematic Reviews (PROSPERO). We searched and identified articles of the subsequent bibliographic databases: PubMed and Cochrane. Revised Cochrane risk-of-bias tool for randomized trials (RoB 2.0) was used to assess the risk of bias of studies included in this review. Results: There were only six clinical trials examining the efficacy of PBM therapy in the primary prevention of chemotherapy-induced oral mucositis. All of the studies used lasers, except for one study that compared lasers with light-emitting diodes. The wavelength ranges from 630 to 830 nm. Irradiation parameters varied among the included studies. All studies showed good results for the use of PBM in the prevention of oral mucositis except for one study that found no benefit for the laser application. Conclusions: PBM has been shown to be effective in preventing oral mucositis when applied to healthy tissues. Finding the optimal protocol has been difficult due to the variability between studies, and therefore, further well-designed, controlled, blinded studies are recommended to precisely determine irradiation parameters and the number of sessions. This review has been registered at the International Prospective Register of Systematic Reviews (PROSPERO) under number CRD42023397771.

Electroacupuncture preconditioning protects against myocardial ischemia-reperfusion injury by modulating dynamic inflammatory response.

Background: The protective effects of electroacupuncture (EA) preconditioning against myocardial ischemia-reperfusion injury (MIRI) have been reported. However, the underlying mechanism remains unclear. Recent research has indicated that the dynamic inflammatory response following MIRI plays an essential role in the progression of myocardial injury. This study aimed to investigate the myocardial protective effects of EA preconditioning on MIRI in rats and to explore the relevant mechanism from the perspective of dynamic inflammatory response. Methods: A MIRI model was employed, and the rats were subjected to EA on Neiguan for four days prior to modeling. The myocardial protective effect of EA preconditioning was evaluated by echocardiography, Evans blue and triphenyltetrazolium chloride staining. Real-time polymerase chain reaction, Western blot, hematoxylin & eosin staining, and immunohistochemistry were utilized to detect the content of mitochondrial DNA, NOD receptor family protein 3 (NLRP3) inflammasome activation, neutrophil recruitment and macrophage infiltration in blood samples and myocardium below the ligation. Results: We found that EA preconditioning could accelerate the recovery of left ventricle function after MIRI and reduce the myocardial infarction area, thereby protecting the myocardium against MIRI. Furthermore, EA preconditioning was observed to ameliorate mitochondrial impairment, reduce the level of plasma mitochondrial DNA, modulate NLRP3 inflammasome activation, attenuate neutrophil infiltration, and promote the polarization of M1 macrophages towards M2 macrophages in the myocardium after MIRI. Conclusion: EA preconditioning could reduce plasma mtDNA, suppress overactivation of the NLRP3 inflammasome, facilitate the transition from the acute pro-inflammatory phase to the anti-inflammatory reparative phase after MIRI, and ultimately confer cardioprotective benefits.

Screening Serum Biomarkers for Rats Preconditioned with Hyperbaric Oxygen: Potential of Predicting Prognosis for Stroke.

BACKGROUND: Stroke is a major health concern and a leading cause of mortality and morbidity. We and other groups have documented that hyperbaric oxygen preconditioning could significantly alleviate neuronal damage in ischemia‒reperfusion models through various mechanisms. However, we found that some of the subjects did not benefit from preconditioning with hyperbaric oxygen. The preconditioning phenomenon is similar to vaccination, in which the endogenous survival system is activated to fight against further injuries. However, with vaccine inoculations, we could test for specific antibodies against the pathogens to determine if the vaccination was successful. Likewise, this experiment was carried out to explore a biomarker that can reveal the effectiveness of the preconditioning before neuronal injury occurs. METHODS: Middle cerebral artery occlusion (MCAO) was used to induce focal cerebral ischemia-reperfusion injury. 2D-DIGE-MALDI-TOF-MS/MS proteomic technique was employed to screen the differentially expressed proteins in the serum of rats among the control (Con) group (MCAO model without hyperbaric oxygen (HBO) preconditioning), hyperbaric oxygen protective (HBOP) group (in which the infarct volume decreased after HBO preconditioning vs. Con), and hyperbaric oxygen nonprotective (HBOU) group (in which the infarct volume remained the same or even larger after HBO preconditioning vs. Con). Candidate biomarkers were confirmed by western blot and enzyme linked immunosorbent assay (ELISA), and the relationship between the biomarkers and the prognosis of cerebral injury was further validated. RESULTS: Among the 15 differentially expressed protein spots detected in the HBOP group by Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE), 3 spots corresponding to 3 different proteins (haptoglobin, serum albumin, and haemopexin) products were identified by MALDI-TOF-MS/MS. Serum albumin and haemopexin were upregulated, and haptoglobin was downregulated in the HBOP group (p < 0.05 vs. Con and HBOU groups). After the western blot study, only the changes in haemopexin were validated and exhibited similar changes in subjects from the HBOP group in accordance with MALDI-TOF-MS/MS proteomic analysis and enzyme linked immunosorbent assay (ELISA) analysis. The serum level of the hemopexin (HPX) at 2 h after HBO preconditioning was correlated with the infarct volume ratio after MCAO. CONCLUSIONS: Haemopexin may be developed as a predictive biomarker that indicated the effectiveness of a preconditioning strategy against cerebral ischaemic injury.

[Mechanisms of moxibustion preconditioning underlying improving learning-memory ability by regulating polarization of microglia via TLR4/NF-κB signaling pathway in AD rats].

OBJECTIVE: To observe the effect of moxibustion preconditioning on learning-memory ability, Toll like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB) signal pathway related proteins and microglia in rats with Alzheimer's disease (AD), so as to explore its possible mechanisms underlying improvement of AD. METHODS: Male SD rats were randomly divided into normal, sham operation, AD model and pre-moxibustion groups, with 9 rats in each group. Moxibustion was applied to "Baihui"(GV20), "Shenshu"(BL23) and "Zusanli"(ST36) for 15 min, once daily, 6 days as a course of treatment for 3 courses. At the end of moxibustion, the AD model was established by injection of Aß25-35 aggregation solution into the bilateral hippocampus. The sham operation group was only injected with the same amount of 0.9% Nacl solution. The spatial learning-memory ability of rats was detected by Morris water maze test, the ultrastructure of hippocampal neurons was observed by transmission electron microscope (TEM). The histopathological changes of hippocampus tissue were observed by HE staining, and the protein expression levels of TLR4 and NF-κB p65 in the hippocampus detected by Western blot, and the positive expressions of Iba-1, CD80 and CD206 in the hippocampal CA1 region were detected by immunofluorescence labeling. The contents of inflammatory factors IL-1ß, TNF-α and IL-10 in the hippocampus were measured by ELISA. RESULTS: Compared with the sham operation group, the escape latency was significantly increased (P<0.01), and the number of platform quadrant crossing times was decreased (P<0.01) in the model group. In comparison with the model group, the increased escape latency and the decreased platform quadrant crossing times were reversed in the pre-moxibustion group (P<0.01). TEM and light microscope observation showed loose arrangement of cells, enlarged cell space, degeneration, swelling and deformation of hippocampal neurons, rupture of membranes of a large number of cells, reduction of mitochondria, dilation of endoplasmic reticulum, and matrix vacuoles, uneven distribution of organelles and cytoplasm, and being difficult in distinguishing the nuclear cytoplasm in the model group, which was relatively milder in the pre-moxibustion group. The expression levels of hippocampal NF-κB p65 and TLR4, the mean immunofluorescence density of Iba-1 and CD80, as well as the contents of IL-1ß and TNF-α in hippocampal CA1 region were significantly increased in the model group than those in the sham operation group (P<0.01), and obviously decreased in the pre-moxibustion group than those in the model group (P<0.05, P<0.01). Whereas the expression of CD206 and the content of IL-10 were evidently decreased in the model group than those in the sham operation group (P<0.01), and strikingly increased in the pre-moxibustion group than those in the model group (P<0.01). No significant differences were found between the sham operation group and the normal group in all the indexes mention above (P>0.05). CONCLUSION: Pre-moxibustion at GV20, BL23 and ST36 can improve learning-memory ability in AD rats, which may be associated with its functions in promoting the polarization of microglia from M1 to M2 and reducing the neuroinflammatory response by way of TLR4/NF-κB signaling pathway.

Hydrogen peroxide preconditioning is of dual role in cardiac ischemia/reperfusion.

Moderate reactive oxygen species (ROS) at reperfusion would trigger cardioprotection and various antioxidants for pharmacological preconditioning failed to achieve cardioprotection. The causes for different roles of preischemic ROS during cardiac ischemia/reperfusion (I/R) require reevaluation. We investigated the precise role of ROS and its working model in this study. Different doses of hydrogen peroxide (H2O2, the most stable form of ROS) were added 5 min before ischemia using isolated perfused rat hearts, only moderate-dose H2O2 preconditioning (H2O2PC) achieved contractile recovery, whereas the low dose and high dose led to injury. Similar results were observed in isolated rat cardiomyocytes on cytosolic free Ca2+ concentration ([Ca2+]c) overload, ROS production, the recovery of Ca2+ transient, and cell shortening. Based on the data mentioned above, we set up a mathematics model to describe the effects of H2O2PC with the fitting curve by the percentage of recovery of heart function and Ca2+ transient in I/R. Besides, we used the two models to define the initial thresholds of H2O2PC achieving cardioprotection. We also detected the expression of redox enzymes and Ca2+ signaling toolkits to explain the mathematics models of H2O2PC in a biological way. The expression of tyrosine 705 phosphorylation of STAT3, Nuclear factor E2-related factor 2, manganese superoxide dismutase, phospholamban, catalase, ryanodine receptors, and sarcoendoplasmic reticulum calcium ATPase 2 were similar with the control I/R and low-dose H2O2PC but were increased in the moderate H2O2PC and decreased in the high-dose H2O2PC. Thus, we concluded that preischemic ROS are of dual role in cardiac I/R.

[Protective effect of moxibustion preconditioning in rats with premature ovarian insufficiency].

OBJECTIVE: To observe the effects of moxibustion preconditioning on ovarian function, fertility and ovarian granulosa cell apoptosis in rats with premature ovarian insufficiency (POI), so as to investigate its underlying mechanism in improving POI. METHODS: Forty-two female SD rats with two complete estrous cycles were randomly divided into control group, model group and pre-moxibustion group, with 14 rats in each group. The pre-moxibustion group was pretreated with mild moxibustion for 14 days before POI model establishment at 1) "Guanyuan" (CV4) and "Zhongwan" (CV12) and 2) bilateral "Shenshu" (BL23) as two sets of acupoints on alternate days, once each day, for 10 min each acupoint. After 14-day mild moxibustion intervention, 75 mg·kg-1·d-1 tripterygium glycoside tablet suspension was administered to rats in the pre-moxibustion group and the model group by gavage, for 14 consecutive days, while equivalent saline was given to rats in the control group in the same way. After modeling, the effect of moxibustion preconditioning on ovarian reserve function was evaluated by the estrous cycles, pregnancy rate and embryo number, morphological changes of ovaries, and serum sex hormone levels. TUNEL staining was used to detect the rate of granulosa cell apoptosis in ovaries. Immunohistochemistry and real time quantitative PCR were used to detect the relative expression of Caspase-3 and Caspase-9 proteins and mRNA levels in ovaries. RESULTS: Compared with the control group, the estrous cycles were disturbed; the pregnancy rate and number of embryos, the wet weight of ovary and ovarian index, the number of total follicles and different level of follicles, serum Estradiol (E2) and anti-mullerian hormone (AMH) levels were all significantly decreased (P<0.01,P<0.05), while the number of atretic follicles, serum follicule-stimulating hormone (FSH) and luteinizing hormone (LH) levels, the number of TUNEL-positive granulosa cells, the expression of ovarian Caspase-3 and Caspase-9 proteins and mRNAs were significantly increased (P<0.01) in the model group. Compared with the model group, the disordered estrous cycles were improved; the pregnancy rate, the embryo numbers, the wet weight of ovary, and the total follicle number and primary follicle number, serum AMH level were significantly increased (P<0.01，P<0.05), while the number of atretic follicles, serum FSH level, the number of TUNEL-positive granulosa cells, expression of ovarian Caspase-3 and Caspase-9 proteins and mRNAs were all significantly decreased (P<0.01,P<0.05) in the moxibustion group. CONCLUSION: Moxibustion preconditioning could improve ovarian function and improve fertility of POI rats, which may be associated with reducing the apoptosis of ovarian granulosa cells.

An overview of hyperbaric oxygen preconditioning against ischemic stroke.

Ischemic stroke (IS) has become the second leading cause of morbidity and mortality worldwide, and the prevention of IS should be given high priority. Recent studies have indicated that hyperbaric oxygen preconditioning (HBO-PC) may be a protective nonpharmacological method, but its underlying mechanisms remain poorly defined. This study comprehensively reviewed the pathophysiology of IS and revealed the underlying mechanism of HBO-PC in protection against IS. The preventive effects of HBO-PC against IS may include inducing antioxidant, anti-inflammation, and anti-apoptosis capacity; activating autophagy and immune responses; upregulating heat shock proteins, hypoxia-inducible factor-1, and erythropoietin; and exerting protective effects upon the blood-brain barrier. In addition, HBO-PC may be considered a safe and effective method to prevent IS in combination with stem cell therapy. Although the benefits of HBO-PC on IS have been widely observed in recent research, the implementation of this technique is still controversial due to regimen differences. Transferring the results to clinical application needs to be taken carefully, and screening for the optimal regimen would be a daunting task. In addition, whether we should prescribe an individualized preconditioning regimen to each stroke patient needs further exploration.

Effect of Ischemic Preconditioning on Acute Recovery in Elite Judo Athletes: A Randomized, Single-Blind, Crossover Trial.

PURPOSE: The ischemic preconditioning (IPC) method has been shown to aid the recovery processes; however, no studies have been done to assess its acute recovery use in judo. This study aimed to examine IPC of lower limbs effects on recovery after a judo-specific performance in highly trained male judokas and its applicability during a competition day. METHODS: A single-blind, placebo-randomized crossover study was carried out on a sample of 13 elite male judo athletes. They undertook measurements of body composition, judo-specific task (Special Judo Fitness Test), jump performance, handgrip strength, lactate, blood pressure, perceived exertion, and delayed-onset muscle soreness. IPC was applied on the legs and inflated 50 mm Hg above the systolic blood pressure for 5 minutes and repeated 3 times for each leg, with 5 minutes of reperfusion. Two-way analysis of variance with repeated measurements was used to determine changes between interventions and measurement times. Paired-sample t test and 1-way repeated-measures analysis of variance was used to determine the difference among measurement times. Statistical significance was set at P < .05. RESULTS: The IPC intervention resulted in (1) decreased heart rate at 30 and 60 minutes during recovery (P = .002; P = .001), (2) better countermovement jump performance at 60 minutes (P = .05), (3) lower perceived-muscle-soreness scores (P = .006), and (4) maintained handgrip strength compared with placebo. CONCLUSIONS: The present study revealed that IPC applied to judo athletes following judo-specific exercise resulted in better cardiovascular and neuromuscular recovery and could be a useful tool to enhance recovery during judo competition breaks between preliminaries and final block.

Glutamatergic neurons in lateral hypothalamus play a vital role in acupuncture preconditioning to alleviate MIRI.

Myocardial ischemia-reperfusion injury (MIRI) has high morbidity and mortality worldwide. Increasing evidence has shown that electroacupuncture (EA) plays a critical role in alleviating MIRI. The aim of this study is to investigate whether glutamatergic neurons in the lateral hypothalamus (LH) have vital effect on MIRI as well as the underlying mechanism during the EA pretreatment. The MIRI model was established by ligating the left anterior descending (LAD) coronary artery for 30 min followed by reperfusion for 2 h. Chemogenetics, electrocardiogram (ECG) recording, ELISA, multichannel physiology recording, and immunofluorescence staining methods were combined to demonstrate that firing frequencies of neurons in the LH and expression of c-Fos decreased by EA pretreatment. Meanwhile, EA preconditioning significantly reduced the percentage of infarct size and the levels of cardiac troponin I (cTnI) and creatine kinase isoenzymes (CK-MB) were similar to inhibition of glutamatergic neurons in LH, also attenuated morphology of myocardial tissue was induced by MIRI. However, activation of glutamatergic neurons in LH weakened the above effects of EA pretreatment.NEW & NOTEWORTHY This study demonstrates that EA preconditioning can attenuate myocardial injury for MIRI, which is similar to inhibition of glutamatergic neurons in LH. However, chemical activation of glutamatergic neurons in LH attenuates the protective effect of EA pretreatment. These findings help better understand the mechanisms of EA to regulate cardiac function.

Effects of electroacupuncture preconditioning of "Neiguan"(PC 6) on myocardial ischemia reperfusion injury via Akt/mTOR pathway / 国际中医中药杂志

Objective:To observe the effects of electroacupuncture preconditioning on the autophagy-related pathway protein kinase B (Akt)/mammalian target of rapamycin (mTOR) in myocardial tissue of rats with myocardial ischemia reperfusion injury (MIRI); To investigate the protective mechanism of "Neiguan"(PC 6) on myocardial injury.Methods:Totally 48 SD rats were randomly divided into blank group, sham-operation group, model group and Neiguan group ( n=12 in each group). The Neiguan group was applied to bilateral "Neiguan"(PC 6) by electroacupuncture for 30 min, once daily for consecutive 7 days before model replication. Except in the blank group, the MIRI model was established by ligation of the descending anterior branch of the left coronary artery in the rest groups after the intervention. The histomorphological changes in the myocardium of the rats were observed by HE staining, and the expression levels of Akt, phosphorylated Akt (p-Akt), mTOR and phosphorylated mTOR (p-mTOR) in the myocardium were measured by protein immunoblotting. The ratio of p-Akt/Akt and p-mTOR/mTOR was calculated. Results:In the blank group, the myocardial fibres were arranged regularly and neatly, and no inflammatory cell infiltration or haemorrhage was seen in the interstitium; in the sham-operation group, the arrangement of myocardial fibers was slightly irregular, no rupture was found, and a small amount of myocardial fiber gap was slightly enlarged; in the model group, the distribution of myocardial fibers was disordered, hypertrophic cardiomyocytes increased, some mitochondria were red and swollen or the outer membrane was ruptured, and inflammatory infiltration and hemorrhage were seen in the interstitium; the extent of myocardial lesions in the Neiguan group was less than that in the model group, with a small amount of interstitial hemorrhage and inflammatory cell infiltration. There was no statistical significance in the levels of Akt and mTOR in the myocardial tissues of the rats in each group ( P>0.05); compared with the sham-operation group, the levels of p-Akt, p-mTOR and p-Akt/Akt, p-mTOR/mTOR in the model group decreased ( P<0.01); compared with the model group, the levels of p-Akt, p-mTOR and p-Akt/Akt, p-mTOR/mTOR in the Neiguan group increased ( P<0.01). Conclusion:Electroacupuncture preconditioning may inhibit excessive autophagy by activating the Akt/mTOR pathway in cardiomyocytes of MIRI rats, thereby exerting a protective effect on the myocardium.

[Effect of different electrical current intensities of electroacupuncture preconditioning on cardiac function and macrophage polarization in mice with acute myocardial ischemia].

OBJECTIVE: To observe the effect of different intensities of electroacupuncture (EA) preconditioning on car-diac function and polarization state of macrophages in mice with acute myocardial ischemia (AMI), so as to explore its possible mechanism underlying improvement of AMI. METHODS: A total of 50 male C57BL/6J mice were randomly divided into sham ope-ration, AMI model, and EA pretreatment groups (0.5 mA, 1 mA, 3 mA subgroups), with 10 mice in each group/subgroup. The mice in the EA pretreatment groups were subjected to EA stimulation of bilateral "Neiguan"(PC6) with 0.5, 1.0 and 3 mA respectively and frequency of 2 Hz/15 Hz for 20 min, once a day, for 3 days. The acute myocardial ischemia model was established by ligating the anterior descending branch (ADB) of the left coronary artery, while the sham operation only had a surgical suture trans-passed below the ADB but without ligation. The myocardial infarction area was measured after TTC staining, and the cardiac function ï¼»left ventricular ejection fraction (EF), short-axis contraction rate (FS)ï¼½ was detected by using echocardiography. The M1 macrophages were labeled with CD11b+F480+CD206low, M2 macrophages were labeled with CD11b+F480+CD206high and detected by using flow cytometry, and the expression levels of myocardial interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), Toll-like receptor-4 (TLR4) proteins were detected by using Western blot. RESULTS: Compared with the sham operation group, the model group had a significant increase in the infarction area (P<0.000 1), number of cardiac macrophages and percentage of M1 type macrophages (P<0.000 1), and the expression levels of myocardial IL-1ß, TNF-α, TLR4 proteins (P<0.001, P<0.01), and a remarkable decrease in the levels of EF, FS and the percentage of M2 type macrophages (P<0.000 1). In contrast to those of the model group, the area of myocardial infarction (P<0.000 1, P<0.01), expression levels of myocardial IL-1ß, TNF-α, TLR4 proteins (P<0.01, P<0.05, P<0.001) in the 0.5 mA, 1 mA and 3 mA groups, number of macrophages and percentage of M1 macrophages (P<0.05) in the 1 mA group were significantly decreased, while the levels of EF and FS (P<0.000 1, P<0.05, P<0.001) in the 3 EA groups, and percentage of M2 macrophage (P<0.05) in the 1 mA group were significantly increased. Comparison among the 3 EA groups displayed that the effects of 1 mA group were significantly superior to those of 0.5 and 3 mA groups in up-regulating EF and FS (P<0.01, P<0.001), and in down-regulating the area of infarct myocardium (P<0.01, P<0.000 1), and the expression of TLR4 protein (P<0.01), and 0.5 mA group in the expression of IL-1ß and TNF-α proteins (P<0.05). CONCLUSION: EA preconditioning with electrical current intensities of 0.5 mA, 1 mA and 3 mA can effectively reduce myocardial infarction size, improve cardiac function in mice with AMI, which may be related with its effects in reducing the number of cardiac macrophages and down-regulating the expression of myocardial IL-1ß, TNF-α and TLR4 proteins. The therapeutic effect of 1 mA is better than that of 0.5 and 3 mA.

Non-pharmacological interventions for vascular health and the role of the endothelium.

The most common non-pharmacological intervention for both peripheral and cerebral vascular health is regular physical activity (e.g., exercise training), which improves function across a range of exercise intensities and modalities. Numerous non-exercising approaches have also been suggested to improved vascular function, including repeated ischemic preconditioning (IPC); heat therapy such as hot water bathing and sauna; and pneumatic compression. Chronic adaptive responses have been observed across a number of these approaches, yet the precise mechanisms that underlie these effects in humans are not fully understood. Acute increases in blood flow and circulating signalling factors that induce responses in endothelial function are likely to be key moderators driving these adaptations. While the impact on circulating factors and environmental mechanisms for adaptation may vary between approaches, in essence, they all centre around acutely elevating blood flow throughout the circulation and stimulating improved endothelium-dependent vascular function and ultimately vascular health. Here, we review our current understanding of the mechanisms driving endothelial adaptation to repeated exposure to elevated blood flow, and the interplay between this response and changes in circulating factors. In addition, we will consider the limitations in our current knowledge base and how these may be best addressed through the selection of more physiologically relevant experimental models and research. Ultimately, improving our understanding of the unique impact that non-pharmacological interventions have on the vasculature will allow us to develop superior strategies to tackle declining vascular function across the lifespan, prevent avoidable vascular-related disease, and alleviate dependency on drug-based interventions.

[Electroacupuncture preconditioning alleviates renal injury and oxidative stress through Sirt3/MnSOD pathway in type 2 diabetic rats].

OBJECTIVE: To explore the protective effect and molecular mechanism of electroacupuncture (EA) preconditioning on renal injury in type 2 diabetic rats. METHODS: Fifty male Wistar rats were randomly divided into control, model, EA, EA+inhibitor, and inhibitor groups, with 10 rats in each group. Diabetes model was established by high fat and high glucose diet and intraperitoneal injection of streptozotocin (40 mg/kg). EA (2 Hz, 1 mA) preconditioning was applied to "Guanyuan" (CV4), "Zhongwan" (CV12), bilateral "Zusanli" (ST36) and "Fenglong" (ST40) for 15 min, once every other day for 8 weeks. Rats of the inhibitor and EA+inhibitor groups were given intraperitoneal injection of 3-TYP (50 mg/kg) once every other day for a total of 3 times. The body weight, kidney mass, and renal index were recorded. The contents of urine microalbumin (ALB), 24 h urine 8-hydroxydeoxyguanosine (8-OHdG) and activities of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione glycine peroxidase (GSH-Px) in kidney were detected by ELISA. The activities of mitochondrial respiratory chain enzyme complex (RCCⅠ-RCCⅣ) in kidney were detected using spectrophotometric method. HE staining, Masson staining and transmission electron microscopy were used to observe the changes of renal structure. The protein and mRNA expressions of silent information regulator 3 (Sirt3), manganese superoxide dismutase (MnSOD) in kidney were detected by Western blot and quantitative real-time PCR, respectively. RESULTS: After modeling and compared with the control group, the contents of ALB, the renal index, activity of ROS and content of 8-OHdG, and the renal collagen volume fraction (CVF) were increased (P<0.01), while the activities of SOD, CAT and GSH-Px, RCCⅠ-RCCⅣ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.01). After the treatment and compared with the model group, the contents of ALB, the renal index, ROS, 8-OHdG, and the CVF were decreased in the EA group(P<0.01, P<0.05), while the activities of SOD, CAT, GSH-Px, RCCⅠ-RCCⅣ, and Sirt3 and MnSOD expression levels were increased (P<0.01, P<0.05)；the RCCⅡ activity and the expression level of MnSOD mRNA were increased (P<0.05) in the EA+inhibitor group; the ALB and 8-OHdG contents and the CVF in the inhibitor group were increased (P<0.05), while the activity of SOD, and Sirt3 and MnSOD expression levels were decreased (P<0.05). In comparison with the EA group, the contents of ALB, the renal index, activities of ROS and 8-OHdG contents, and the CVF were increased (P<0.05, P<0.01), activities of SOD, CAT and GSH-Px and RCCⅠ and RCCⅡ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.05, P<0.01) in both EA+inhibitor group and inhibitor group, whereas the activities of RCCⅢ and RCCⅣ were decreased in the inhibitor group (P<0.05). The therapeutic effect of inhibitor was notably inferior to that of EA+inhibitor in decreasing ALB and 8-OHdG contents, and CVF (P<0.01), and in up-regulating SOD and RCCⅡ activities, Sirt3 and MnSOD expression levels (P<0.01, P<0.05). CONCLUSION: EA preconditioning can increase the expressions of renal Sirt3 and MnSOD in type 2 diabetic rats, thereby reducing the oxidative stress response and protecting the kidneys.

[Electroacupuncture preconditioning improves pulmonary function via inhibiting inflammatory response and up-regulating expression of ACE2 and Ang (1-7) in lipopolysaccharide-induced acute lung injury rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zusanli"(ST36) pretreatment on lung functions, inflammatory response, and levels of angiotensin-converting enzyme 2 (ACE2) and angiotensin (1-7) ï¼»Ang (1-7)ï¼½ in rats with sepsis-induced acute lung injury (ALI), so as to explore its mechanisms underlying improvement of ALI. METHODS: Thirty male SD rats were randomly divided into normal, model and EA groups (n=10 in each group). The sepsis-related ALI model was established by intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg). Rats of the EA group received EA (4 Hz/20 Hz, 1-3 mA) stimulation at bilateral ST36 for 30 min, once each day, for 7 days before modeling. The lung functions including forced vital capacity (FVC), forced expiratory volume at 0.1 second (FEV0.1) and FEV0.3 were detected using a respiratory function detector for small animals at 3 h after modeling. The bronchoalveolar lavage fluid (BALF) was collected for assaying the contents of Ang (1-7), tumor necrosis factor-α (TNF-α) and interleukin-1 ß (IL-1ß) using ELISA. The lung wet/dry weight (W/D) ratio, FEV0.1/FVC, and FEV0.3/FVC were calculated. The histopathological changes of lung tissues were displayed by hematoxylin-eosin (H.E.) staining. The expression of ACE2 and mitochondrial assembly receptor (MasR) mRNAs and proteins in the lung tissue was detected by fluorescence quantitative real-time PCR and Western blot, separately. RESULTS: Following modeling, the levels of FVC, FEV0.1, FEV0.3, ratio of FEV0.1/FVC and FEV0.3/FVC, content of Ang (1-7) in the BALF, and the expression levels of ACE2 and MasR mRNAs and proteins in the lung tissue were significantly decreased (P<0.01), while the level of W/D ratio and TNF-α and IL-1ß contents in the BALF significantly increased (P<0.01) in the model group relevant to the normal group. In comparison with the model group, the levels of FVC, FEV0.1, FEV0.3, ratio of FEV0.1/FVC and FEV0.3/FVC, content of Ang (1-7) in the BALF, and expression levels of ACE2 and MasR mRNAs and proteins in the lung tissue were significantly increased (P<0.05, P<0.01), whereas the level of W/D ratio, and TNF-α and IL-1ß contents in the BALF were significantly decreased (P<0.05, P<0.01) in the EA group. H.E. staining showed pulmonary interstitial edema and alveolar septum thickening with severe inflammatory cell infiltration in the model group, which was relatively milder in the EA group. CONCLUSION: EA preconditioning at ST36 can improve pulmonary function in sepsis-related ALI rats, which may be related to its effects in inhibiting inflammatory response and up-regulating ACE2 and MasR expression and Ang (1-7) content in the lung tissue.

The Effect of Electroacupuncture Preconditioning on Regional Cerebral Oxygen Saturation Levels in Elderly Patients with Diabetes.

Objective: This study aimed to evaluate the effect of electroacupuncture preconditioning on regional cerebral oxygen saturation (rSO2) levels in elderly patients with diabetes. Methods: Forty patients undergoing elective diabetic foot surgery were enrolled in this study. All patients were aged 65 years and above and weighed 45-75 kg. All were characterized as class II or III according to the American Society of Anesthesiologists' physical status classification system. Patients were divided randomly into an electroacupuncture group (group E) and a control group (group C); both groups comprised 20 patients. In group E, the DU20 (Baihui), DU24 (Shenting), and EX-HN1 (Sishencong) acupoints were selected for electroacupuncture 30 min prior to administering anesthesia, while in group C, patients underwent routine anesthesia without electroacupuncture. The patients in both groups were anesthetized using a sciatic nerve block. The number of cases with increased or decreased regional oxygen saturation (rSO2) compared with the baseline as well as rSO2 variability in the two groups were recorded and compared. Results: There was no significant difference in the preoperative rSO2 values between the two groups (54.4 ± 4.8 (L), 53.9 ± 5.2 (R) [group C] vs 54.1 ± 5.2 (L), 54.5 ± 4.6 (R)[group E]). Compared with group C, the rSO2 in group E increased (50.3 ± 3.9 [group C] vs 58.4 ± 3.2[group E]), and this difference was statistically significant (P < 0.001). Conclusion: Electroacupuncture stimulation can increase rSO2 levels in patients with diabetes. Clinical Registration Number: ChiCTR2100048783 (http://www.chictr.org.cn).

Baicalein Preconditioning Cardioprotection Involves Pro-Oxidant Signaling and Activation of Pyruvate Dehydrogenase.

Preconditioning has a powerful protective potential against myocardial ischemia-reperfusion injury (I/R). Our prior work demonstrated that baicalein, a flavonoid derived from the root of Scatellaria baicalensis Georgi (also known as Huangqin), confers this preconditioning protection. This study further explored the mechanisms of baicalein preconditioning (BC-PC) in mouse cardiomyocytes. Cells were treated with baicalein (10 µM) for a brief period of time (10 min) prior to simulated ischemia 90 min/reperfusion for 180 min. Baicalein triggered an induction of a small amount of mitochondrial reactive oxygen species (ROS) prior to the initiation of ischemia, assessed by 6-carboxy-2', 7'-dichlorodihydrofluorescein diacetate (6-carboxy-H2DCFDA). It also significantly increased cell viability measured by propidium iodide (PI) and lactate dehydrogenase and preserved mitochondrial membrane potential assessed by TMRM fluorescence intensity. Myxothiazol, a mitochondrial electron transport chain complex III inhibitor, partially blocked ROS generation induced by BC-PC and reduced cell viability. BC-PC increased phosphorylation of Akt (Thr308 and Ser473) and eNOS Ser1177, and nitric oxide (NO) production measured using 4,5-diaminofluorescein diacetate (DAF-2 DA, 1 µM). Akt inhibitor API-2 abolished Akt phosphorylation and reduced DAF-2 production and cell viability. In addition, BC-PC decreased phosphorylation of pyruvate dehydrogenase (PDH) reflecting upregulated PDH activity, and increased ATP production at 30 min during reperfusion. Taken together, baicalein preconditioning-induced cardioprotection involves pro-oxidant generation, activates survival signaling Akt/eNOS/NO, and improves metabolic recovery after I/R injury. Our work provides new perspectives on the effect of baicalein on cardiac preconditioning against I/R injury.