Thrombomodulin Improves Cognitive Deficits in Heat-Stressed Mice.

BACKGROUND: Thrombomodulin (TM) exerts anticoagulant and anti-inflammatory effects to improve the survival of patients with septic shock. Heat stroke resembles septic shock in many aspects. We tested whether TM would improve cognitive deficits and related causative factors in heat-stressed mice. METHODS: Adult male mice were exposed to HS (33 oC 2h daily for 7 consecutive days) to induce cognitive deficits. Recombinant human soluble thrombomodulin (TM, 1 mg/kg, i.p.) was administered immediately after the first HS trial and then once daily for 7 consecutive days. We performed the Y-maze, novel objective recognition, and passive avoidance tests to evaluate cognitive function. Plasma levels of lipopolysaccharide, high-mobility group box 1 (HMGB1), coagulation parameters, and both plasma and tissue levels of inflammatory and oxidative stress markers were measured biochemically. The duodenum and hippocampus sections were immunohistochemically stained. The intestinal and blood-brain barrier permeability were determined. RESULTS: Compared to controls, HS mice treated with TM had lesser extents of cognitive deficits, exacerbated stress reactions, gut barrier disruption, endotoxemia, blood-brain barrier disruption, and inflammatory, oxidative, and coagulatory injury to heart, duodenum, and hippocampal tissues, and increased plasma HMGB1. In addition to reducing cognitive deficits, TM therapy alleviated all the abovementioned complications in heat-stressed mice. CONCLUSIONS: The findings suggest that heat stress can lead to exacerbated stress reactions, endotoxemia, gut barrier disruption, blood-brain barrier disruption, hippocampal inflammation, coagulopathy, and oxidative stress, which may act as causative factors for cognitive deficits. Thrombomodulin, an anti-inflammatory, antioxidant, and anti-coagulatory agent, inhibited heat stress-induced cognitive deficits in mice.

Hyperbaric oxygen therapy suppresses hypoxia and reoxygenation injury to retinal pigment epithelial cells through activating peroxisome proliferator activator receptor-alpha signalling.

Retinal ischemia followed by reperfusion (IR) is a common cause of many ocular disorders, such as age-related macular degeneration (AMD), which leads to blindness in the elderly population, and proper therapies remain unavailable. Retinal pigment epithelial (RPE) cell death is a hallmark of AMD. Hyperbaric oxygen (HBO) therapy can improve IR tissue survival by inducing ischemic preconditioning responses. We conducted an in vitro study to examine the effects of HBO preconditioning on oxygen-glucose deprivation (OGD)-induced IR-injured RPE cells. RPE cells were treated with HBO (100% O2 at 3 atmospheres absolute for 90 min) once a day for three consecutive days before retinal IR onset. Compared with normal cells, the IR-injured RPE cells had lower cell viability, lower peroxisome proliferator activator receptor-alpha (PPAR-α) expression, more severe oxidation status, higher blood-retinal barrier disruption and more elevated apoptosis and autophagy rates. HBO preconditioning increased PPAR-α expression, improved cell viability, decreased oxidative stress, blood-retinal barrier disruption and cellular apoptosis and autophagy. A specific PPAR-α antagonist, GW6471, antagonized all the protective effects of HBO preconditioning in IR-injured RPE cells. Combining these observations, HBO therapy can reverse OGD-induced RPE cell injury by activating PPAR-α signalling.

Selective brain cooling achieves peripheral organs protection in hemorrhagic shock resuscitation via preserving the integrity of the brain-gut axis.

Background: Although whole-body cooling has been reported to improve the ischemic/reperfusion injury in hemorrhagic shock (HS) resuscitation, it is limited by its adverse reactions following therapeutic hypothermia. HS affects the experimental and clinical bowel disorders via activation of the brain-gut axis. It is unknown whether selective brain cooling achieves beneficial effects in HS resuscitation via preserving the integrity of the brain-gut axis. Methods: Male Sprague-Dawley rats were bled to hypovolemic HS and resuscitated with blood transfusion followed by retrograde jugular vein flush (RJVF) with 4 °C or 36 °C normal saline. The mean arterial blood pressure, cerebral blood flow, and brain and core temperature were measured. The integrity of intestinal tight junction proteins and permeability, blood pro-inflammatory cytokines, and multiple organs damage score were determined. Results: Following blood transfusion resuscitation, HS rats displayed gut barrier disruption, increased blood levels of pro-inflammatory cytokines, and peripheral vital organ injuries. Intrajugular-based infusion cooled the brain robustly with a minimal effect on body temperature. This brain cooling significantly reduced the HS resuscitation-induced gut disruption, systemic inflammation, and peripheral vital organ injuries in rats. Conclusion: Resuscitation with selective brain cooling achieves peripheral vital organs protection in hemorrhagic shock resuscitation via preserving the integrity of the brain-gut axis.

Carbon monoxide-triggered health effects: the important role of the inflammasome and its possible crosstalk with autophagy and exosomes.

Carbon monoxide (CO) has long been known as a "silent killer" because of its ability to bind hemoglobin (Hb), leading to reduced oxygen carrying capacity of Hb, which is the main cause of CO poisoning (COP) in humans. Emerging studies suggest that mitochondria is a key target of CO action that can impact key biological processes, including apoptosis, cellular proliferation, inflammation, and autophagy. Despite its toxicity at high concentrations, CO also exhibits cyto- and tissue-protective effects at low concentrations in animal models of organ injury and disease. Specifically, CO modulates the production of pro- or anti-inflammatory cytokines and mediators by regulating the NLRP3 inflammasome. Given that human diseases are strongly associated with inflammation, a deep understanding of the exact mechanism is helpful for treatment. Autophagic factors and inflammasomes interact in various situations, including inflammatory disease, and exosomes might function as the bridge between the inflammasome and autophagy activation. Thus, the interplay among autophagy, mitochondrial dysfunction, exosomes, and the inflammasome may play pivotal roles in the health effects of CO. In this review, we summarize the latest research on the beneficial and toxic effects of CO and their underlying mechanisms, focusing on the important role of the inflammasome and its possible crosstalk with autophagy and exosomes. This knowledge may lead to the development of new therapies for inflammation-related diseases and is essential for the development of new therapeutic strategies and biomarkers of COP.

Therapeutic Hypothermia Protects Against Heat Stroke-Induced Arterial Hypotension via Promoting Left Ventricular Performance in Rats.

We aimed to ascertain whether therapeutic hypothermia (TH) acts as cardioprotective management for heat stroke (HS). Adult male rats under general anesthesia were exposed to whole-body heating (43°C for 70 min) to induce HS. Rats with HS displayed hyperthermia (core body temperature 42°C vs. 36°C); hypotension (30 mmHg vs. 90 mmHg mean arterial blood pressure); suppressed left ventricular (LV) performance (stroke volume 52 µl/min vs. 125 µl/min), ejection fraction (0.29% vs. 0.69%), relaxation factor (72 ms vs. 12 ms), and arterial elastance (0.31 mmHg/ µl vs. 10 mmHg/ µl); increased myocardial injury markers (e.g., creatine kinase-MB: 86 U/L vs. 24 U/L, cardiac troponin I: 3.08 ng/ml vs. 0.57 ng/ml); increased myocardial oxidative stress markers (e.g., malondialdehyde: 6.52 nmol/mg vs. 1.06 nmol/mg, thiobarbituric acid-reactive substances: 29 nmol/g vs. 2 nmol/g); decreased myocardial antioxidants (e.g., superoxide dismutase: 6 unit/mg vs. 17 unit/mg, reduced glutathione: 0.64 nmol/mg vs. 2.53 nmol/mg); increased myocardial proinflammatory cytokines (e.g., tumor necrosis factor-α 3200 pg/ml vs. 1000 pg/ml, interleukin-6: 668 pg/ml vs. 102 pg/ml); and increased cardiac damage scores (2.2 vs. 0.3). TH therapy significantly reversed the following conditions: HS-induced hyperthermia (37.5°C core body temperature), hypotension (71 mmHg), suppressed LV performance (stroke volume: 97 µl/min, ejection fraction: 0.65%, relaxation factor: 39 ms, and arterial elastance: 0.99 mmHg/µl), increased myocardial injury markers (e.g., creatine kinase-MB: 37 U/L, cardiac troponin I: 1.06 ng/ml), increased myocardial oxidative stress markers (e.g., malondialdehyde: 2.68 nmol/mg, thiobarbituric acid-reactive substances: 12.3 nmol/g), decreased myocardial antioxidants (e.g., superoxide dismutase: 13.3 unit/mg, reduced glutathione: 2.71 mmol/mg), increased myocardial proinflammatory cytokines (e.g., tumor necrosis factor-α 1500 pg/ml, interleukin-6: 108 ng/ml); and increased cardiac damage scores (0.9). We thus conclude that TH protects against HS-induced arterial hypotension by promoting LV performance in rats. These results add to the literature regarding the use of TH as cardioprotective management for HS.

Hypobaric hypoxia preconditioning protects against hypothalamic neuron apoptosis in heat-exposed rats by reversing hypothalamic overexpression of matrix metalloproteinase-9 and ischemia.

Background: Hypoxia-inducible factor-1α (HIF-1α), heat shock protein-72 (HSP-72), hemeoxygenase-1 (HO-1), and matrix metalloproteinase-9 (MMP-9) have been identified as potential therapeutic targets in the brain for cerebral ischemia. To elucidate their underlying mechanisms, we first aimed to ascertain whether these proteins participate in the pathogenesis of heat-induced ischemic damage to the hypothalamus of rats. Second, we investigated whether hypobaric hypoxia preconditioning (HHP) attenuates heat-induced hypothalamic ischemic/hypoxic injury by modulating these proteins in situ. Methods: Anesthetized rats treated with or without HHP were subjected to heat stress. Hypothalamic ischemic/hypoxic damage was evaluated by measuring hypothalamic levels of cerebral blood flow (CBF), partial oxygen pressure (PO2), and hypothalamic temperature via an implanted probe. Hypothalamic apoptotic neurons were counted by measuring the number of NeuN/caspase-3/DAPI triple-stained cells. Hypothalamic protein expression of HIF-1α, HSP-72, HO-1, and MMP-9 was determined biochemically. Results: Before the start of the thermal experiments, rats were subjected to 5 hours of HHP (0.66 ATA or 18.3% O2) daily for 5 consecutive days per week for 2 weeks, which led to significant loss of body weight, reduced brown adipose tissue (BAT) wet weight and decreased body temperature. The animals were then subjected to thermal studies. Twenty minutes after heat stress, heat-exposed rats not treated with HHP displayed significantly higher core and hypothalamic temperatures, hypothalamic MMP-9 levels, and numbers of hypothalamic apoptotic neurons but significantly lower mean blood pressure, hypothalamic blood flow, and PO2 values than control rats not exposed to heat. In heat-exposed rats, HHP significantly increased the hypothalamic levels of HIF-1α, HSP-72, and HO-1 but significantly alleviated body and hypothalamic hyperthermia, hypotension, hypothalamic ischemia, hypoxia, neuronal apoptosis and degeneration. Conclusions: HHP may protect against hypothalamic ischemic/hypoxic injury and overexpression of MMP-9 by upregulating the hypothalamic expression of HIF-1α, HSP-72, and HO-1 in rats subjected to heatstroke.

Individualized Running Wheel System with a Dynamically Adjustable Exercise Area and Speed for Rats Following Ischemic Stroke.

BACKGROUND An innovative animal running wheel with an individualized design was implemented for the rehabilitation of rats following ischemic stroke. MATERIAL AND METHODS The design of the running wheel platform included the running wheel and a side plate for exercise area adjustments. A U-curve with a width of 2 cm was drawn on the lower half of the side plate for the dynamic adjustments of five infrared (IR) sensors based on the physical fitness of the rats. The individualized training process for this running wheel consisted of 2 days of free training to record their average and maximum speeds, 3 days of progressive training to determine their exercise areas, and 2 weeks of normal training based on their average speeds, maximum speeds, and exercise areas. Blood samples were obtained from the tail veins of all rats before the operations and on Days 14, 21, and 28 postsurgery to measure cortisol levels. The motor function tests were performed on Days 7 and 28 postsurgery. On Day 28 postsurgery, the rats were sacrificed under anesthesia, and their brains were removed for Nissl and H&E staining. RESULTS On Day 28 after surgery, the motor function, lesion volume, and cell damage of the DEARW and control groups differed significantly, indicating that this device is effective for stroke rehabilitation. CONCLUSIONS The outcomes of the rats that were rehabilitated using the newly designed training system were better than those of their control-group counterparts, indicating the advantages of this designed system.

Exercise Preconditioning Attenuates Neurological Injury by Preserving Old and Newly Formed HSP72-Containing Neurons in Focal Brain Ischemia Rats.

Background: Exercise preconditioning (EP+) is a useful and important procedure for the prevention of stroke. We aimed to ascertain whether EP+ protects against ischemic brain injury by preserving heat shock protein (HSP) 72-containing neurons in ischemic brain tissues. Methods: Adult male Sprague-Dawley rats (n=240) were used to assess the contribution of HSP72-containing neurons to the neuroprotective effects of EP+ on ischemic brain injury caused by transient middle cerebral artery occlusion. Results: Significant (P<0.05) increases in the percentages of both old HSP72-containing neurons (NeuN+HSP72 double positive cells) (18~20% vs. 40~50%) and newly formed HSP72-containing neurons (BrdU+NeuN+HSP72 triple positive cells); (2~3% vs. 16~20%) after 3 weeks of exercise coincided with significant (P<0.05) reductions in brain ischemia volume (250 mm3 vs. 100 mm3), brain edema (78% vs. 74% brain water content), blood-brain barrier disruption (1.5 µg/g vs. 0.7 µg/g tissue Evans Blue dye extravasation) and neurological motor deficits (neurological severity scores of 12 vs. 6 and maximal angles of 60° vs. 20°) in brain ischemia rats. Reductions in the percentages of both old (from 40~50% to 10~12%) and newly formed (from 18~20% to 5~7%) HSP72-containing neurons by gene silencing with an intracerebral injection of pSUPER small interfering RNA showed a significant (P<0.05) reversal in the neuroprotective outcomes. Our data provide an inverse correlation between the EP+-mediated increases in both old and newly formed HSP72-containing neurons and the extent of cerebral ischemic injury. Conclusions: The percentages of both old and newly formed HSP72-containing neurons are inversely correlated with the outcomes of ischemic brain injury. Additionally, preischemic treadmill exercise improves the outcomes of ischemic brain injury by preserving both the old and newly formed HSP72-containing neurons in rats.

Calycosin-7-O-ß-D-glucoside reduces myocardial injury in heat stroke rats.

BACKGROUND/PURPOSE: Calycosin-7-O-ß-D-glucoside (CG), a calycosin derivative compound derived from Astragali Radix, has protective effect against ischemia/reperfusion injury as well as bacterial endotoxin-induced vascular cell injury. In the present study, we ascertained whether CG could reduce myocardial injury in heatstroke rats. METHODS: Heat stroke was induced by exposing anaesthetized rats to heat stress (43 °C for 70 min). Rats were given an i.p. dose of CG (26.8 mg/ml/kg) or vehicle solution (ml/kg) 15 min before the start of heat stress and immediately after termination of heat stress. Left ventricular performance, myocardial injury markers in the blood, and myocardial damage scores were assessed in heat stroke rats treated with or without CG. Additionally, cardiac levels of oxidative stress and inflammatory status were estimated simultaneously. RESULTS: At the time point of heat stroke onset, compared with normothermic controls, group rats with vehicle solution had significantly decreased survival rate, increased hyperthermia, decreased left ventricular stress markers, and increased cardiac damage scores. Compared with group rats with vehicle solution, group rats with CG had significantly improved survival rate, decreased hyperthermia, decreased cardiac ischemic, inflammatory, and oxidative damage. CONCLUSION: We thus conclude that myocardial injury can be a pressing need for the design of diagnostic and therapeutic modalities for heat stroke. In particular, our data indicate that CG protects against heat stroke in rats by mitigating myocardial injury.

Modulation of parietal cytokine and chemokine gene profiles by mesenchymal stem cell as a basis for neurotrauma recovery.

BACKGROUND & PURPOSE: Following traumatic brain injury (TBI), primary mechanical injury to the brain may cause blood-brain-barrier damage followed by secondary injury, ultimately culminating in cell death. We aimed to test whether one injection of mesenchymal stem cells (MSC) derived from the human umbilical cord can modulate brain cytokine and chemokine gene profiles and attenuate neurological injury in rats with TBI. METHODS: One-day post-TBI, the injured rats were treated with one injection of MSC (4 × 106/rat, i.v.). Three days later, immediately after assessment of neurobehavioral function, animals were sacrificed for analysis of neurological injury (evidenced by both brain contusion volume and neurological deficits) and parietal genes encoding 84 cytokines and chemokines in the injured brain by qPCR methods. RESULTS: Three days post-TBI, rats displayed both neurological injury and upgrade of 11 parietal genes in the ipsilateral brain. One set of 8 parietal genes (e.g., chemokine [C-X-C motif] ligand 12, platelet factor 4, interleukin-7, chemokine [C-C motif] ligand (CCL)19, CCL 22, secreted phosphoprotein 1, pro-platelet basic protein 1, and CCL 2) differentially upgraded by TBI was related to pro-inflammatory and/or neurodegenerative processes. Another set of 3 parietal genes up-graded by TBI (e.g., glucose-6-phosphate isomerase, bone morphogenetic protein (BMP) 2, and BMP 4) was related to anti-inflammatory/neuroregenerative events. Administration of MSC attenuated neurological injury, down-regulated these 8 parietal pro-inflammatory genes, and up-regulated these 3 parietal anti-inflammatory genes in the rats with TBI. CONCLUSION: Our data suggest that modulation of parietal cytokines and chemokines gene profiles by MSC as a basis for neurotrauma recovery.

Heat Shock Protein 70 (HSP70) Reduces Hepatic Inflammatory and Oxidative Damage in a Rat Model of Liver Ischemia/Reperfusion Injury with Hyperbaric Oxygen Preconditioning.

BACKGROUND Several clinical conditions can cause hepatic ischemia/reperfusion (I/R) injury. This study aimed to determine the mechanism of the protective effect of hyperbaric oxygen preconditioning (HBO2P) on hepatic ischemia/reperfusion (I/R) injury in a rat model, and to investigate the effects on HBO2P and I/R injury of blocking HSP70 using antibody (Ab) pretreatment. MATERIAL AND METHODS Male Sprague-Dawley rats underwent HBO2P for 60 min at 2.0 atmosphere absolute (ATA) pressure for five consecutive days before surgical hepatic I/R injury, performed by clamping the portal vein and hepatic lobe. Four groups studied included: the non-HBO2P+ non-I/R group, which underwent sham surgery (N=10); the non-HBO2P + I/R group (N=10); the HBO2P + I/R group (N=10); and the HBO2P + HSP70-Ab + I/R group (N=10) received one dose of HSP70 antibody one day before hepatic I/R injury. Serum lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and hepatic malondialdehyde (MDA) and myeloperoxidase (MPO) were measured biochemically. Rat liver tissues were examined histologically. RESULTS In rats with hepatic I/R injury without HSP70 antibody pre-treatment, HBO2P significantly reduced hepatic injury and levels of LDH, AST, ALT, TNF-α, IL-6, MDA, and MPO levels; in comparison, the group pre-treated with an antibody to inhibit HSP70 (the HBO2P + HSP70-Ab + I/R group) showed significant reversal of the beneficial effects of HBO2P on hepatic I/R injury (p<0.05). CONCLUSIONS In a rat model of hepatic I/R injury with HBO2P, HSP70 reduced hepatic inflammatory and oxidative damage.

Gamma-Secretase Inhibitors Attenuate Neurotrauma and Neurogenic Acute Lung Injury in Rats by Rescuing the Accumulation of Hypertrophic Microglia.

BACKGROUND/AIMS: In response to traumatic brain injury (TBI), activated microglia exhibit changes in their morphology from the resting ramified phenotype toward the activated hypertrophic or amoeboid phenotype. Here, we provide the first description of the mechanism underlying the neuroprotective effects of γ-secretase inhibitors on TBI outcomes in rats. METHODS: The neuroprotective effects of γ-secretase inhibitors such as LY411575 or CHF5074 on TBI-induced neurotoxicity were analysed using a neurological motor function evaluation, cerebral contusion assay, immunohistochemical staining for microglia phenotypes, lung injury score and Evans Blue dye extravasation assay of brain and lung oedema. RESULTS: Hypertrophic or amoeboid microglia accumulated in the injured cortex, the blood-brain-barrier was disrupted and neurological deficits and acute lung injury were observed 4 days after TBI in adult rats. However, a subcutaneous injection of LY411575 (5 mg/kg) or CHF5074 (30 mg/kg) immediately after TBI and once daily for 3 consecutive days post-TBI significantly attenutaed the accumulation of hypertrophic microglia in the injured brain, neurological injury, and neurogenic acute lung injury. CONCLUSION: Gamma-secretase inhibitors attenuated neurotrauma and neurogenic acute lung injury in rats by reducing the accumulation of hypertrophic microglia in the vicinity of the lesion.

Exercise attenuates neurological deficits by stimulating a critical HSP70/NF-κB/IL-6/synapsin I axis in traumatic brain injury rats.

BACKGROUND: Despite previous evidence for a potent inflammatory response after a traumatic brain injury (TBI), it is unknown whether exercise preconditioning (EP) improves outcomes after a TBI by modulating inflammatory responses. METHODS: We performed quantitative real-time PCR (qPCR) to quantify the genes encoding 84 cytokines and chemokines in the peripheral blood and used ELISA to determine both the cerebral and blood levels of interleukin-6 (IL-6). We also performed the chromatin immunoprecipitation (ChIP) assay to evaluate the extent of nuclear factor kappa-B (NF-κB) binding to the DNA elements in the IL-6 promoter regions. Also, we adopted the Western blotting assay to measure the cerebral levels of heat shock protein (HSP) 70, synapsin I, and ß-actin. Finally, we performed both histoimmunological and behavioral assessment to measure brain injury and neurological deficits, respectively. RESULTS: We first demonstrated that TBI upregulated nine pro-inflammatory and/or neurodegenerative messenger RNAs (mRNAs) in the peripheral blood such as CXCL10, IL-18, IL-16, Cd-70, Mif, Ppbp, Ltd, Tnfrsf 11b, and Faslg. In addition to causing neurological injuries, TBI also upregulated the following 14 anti-inflammatory and/or neuroregenerative mRNAs in the peripheral blood such as Ccl19, Ccl3, Cxcl19, IL-10, IL-22, IL-6, Bmp6, Ccl22, IL-7, Bmp7, Ccl2, Ccl17, IL-1rn, and Gpi. Second, we observed that EP inhibited both neurological injuries and six pro-inflammatory and/or neurodegenerative genes (Cxcl10, IL-18, IL-16, Cd70, Mif, and Faslg) but potentiated four anti-inflammatory and/or neuroregenerative genes (Bmp6, IL-10, IL-22, and IL-6). Prior depletion of cerebral HSP70 with gene silence significantly reversed the beneficial effects of EP in reducing neurological injuries and altered gene profiles after a TBI. A positive Pearson correlation exists between IL-6 and HSP70 in the peripheral blood or in the cerebral levels. In addition, gene silence of cerebral HSP70 significantly reduced the overexpression of NF-κB, IL-6, and synapsin I in the ipsilateral brain regions after an EP in rats. CONCLUSIONS: TBI causes neurological deficits associated with stimulating several pro-inflammatory gene profiles but inhibiting several anti-inflammatory gene profiles of cytokines and chemokines. Exercise protects against neurological injuries via stimulating an anti-inflammatory HSP70/NF-κB/IL-6/synapsin I axis in the injured brains.

Combined Hemorrhagic Shock and Unilateral Common Carotid Occlusion Induces Neurological Injury in Adult Male Rats.

Background: Clinical assessment reveals that patients after surgery of cardiopulmonary bypass or coronary bypass experience postoperative cognitive dysfunction. This study aimed to investigate whether resuscitation after a hemorrhagic shock (HS) and/or mild cerebral ischemia caused by a unilateral common carotid artery occlusion (UCCAO) can cause brain injury and concomitant neurological dysfunction, and explore the potential mechanisms. Methods: Blood withdrawal (6 mL/100 g body weight) for 60 min through the right jugular vein catheter-induced an HS. Immediately after the termination of HS, we reinfused the initially shed blood volumes to restore and maintain the mean arterial blood pressure (MABP) to the original value during the 30-min resuscitation. A cooling water blanket used to induce whole body cooling for 30 min after the end of resuscitation. Results: An UCCAO caused a slight cerebral ischemia (cerebral blood flow [CBF] 70%) without hypotension (MABP 85 mmHg), systemic inflammation, multiple organs injuries, or neurological injury. An HS caused a moderate cerebral ischemia (52% of the original CBF levels), a moderate hypotension (MABP downed to 22 mmHg), systemic inflammation, and peripheral organs injuries. However, combined an UCCAO and an HS caused a severe cerebral ischemia (18% of the original CBF levels), a moderate hypotension (MABP downed to 17 mmHg), systemic inflammation, peripheral organs damage, and neurological injury, which can be attenuated by whole body cooling. Conclusions: When combined with an HS, an UCCAO is associated with ischemic neuronal injury in the ipsilateral hemisphere of adult rat brain, which can be attenuated by therapeutic hypothermia. A resuscitation from an HS regards as a reperfusion insult which may induce neurological injury in patients with an UCCAO disease.

A positive correlation exists between neurotrauma and TGF-ß1-containing microglia in rats.

BACKGROUND: Transforming growth factor-beta 1 (TGF-ß1) regulates many processes after traumatic brain injury (TBI). Both Neuro AiD™ (MLC601) and astragaloside (AST) attenuate microglia activation in rats with TBI. The purpose of this study was to investigate whether MLC601 or AST improves output of TBI by affecting microglial expression of TGF-ß1. MATERIALS AND METHODS: Adult male Sprague-Dawley rats (120 in number) were used to investigate the contribution of TGF-ß1-containing microglia in the MLC601-mediated or the AST-mediated neuroprotection in the brain trauma condition using lateral fluid percussion injury. RESULTS: Pearson correlation analysis revealed that there was a positive correlation between brain injury (evidenced by both brain contused volume and neurological severity score) and the cortical numbers of TGF-ß1-containing microglia for the rats (n = 12) 4 days post-TBI. MLC601 or AST significantly (P < 0·05) attenuated TBI-induced brain contused volume (119 ± 14 mm3 or 108 ± 11 mm3 vs. 160 ± 21 mm3 ), neurological severity score (7·8 ± 0·3 or 8·1 ± 0·4 vs. 10·2 ± 0·5) and numbers of TGF-ß1-containing microglia (6% ± 2% or 11% ± 3% vs. 79% ± 7%) for the rats 4 days post-TBI. CONCLUSIONS: There was a positive correlation between TBI and cortical numbers of TGF-ß1-containing microglia which could be significantly attenuated by astragaloside or NeuroAiD™ (MLC601) in rats.

Proteomic analysis of hypothalamic injury in heatstroke rats.

Ischemic and oxidative damage to the hypothalamus may be associated with decreased heat tolerance as well as heatstroke formation. The present study explores the hypothalamic proteome mechanisms associated with heatstroke-mediated hypothalamic ischemia, and oxidative damage. Heatstroke rats had hypotension, hypothalamic ischemia, and lethality. In addition, they had hyperthermia and hypothalamic blood-brain-barrier disruption, oxidative stress, activated inflammation, and neuronal apoptosis and degeneration. 2DE combined LC-MS/MS revealed that heatstroke-induced ischemic injury and apoptosis were associated with upregulation of L-lactate dehydrogenase but downregulation of both dihydropyriminase-related protein and 14-3-3 Zeta isoform protein. Heat-induced blood-brain-barrier disruption might be related to upregulation of glial fibrillary acidic protein. Oxidative stress caused by heatstroke might be related to upregulation of cytosolic dehydrogenase-1. Also, heat-induced overproduction of proinflammatory cytokines might be associated with downregulation of stathmin 1. Heat-induced hypothalamic ischemia, apoptosis, injury (or upregulation of L-lactate dehydrogenase), blood-brain-barrier disruption (or upregulation of glial fibrillary acidic protein), oxidative stress (or upregulation of cytosolic dehydrogenase-1), and activated inflammation (or downregulation of stathmin 1) were all significantly reversed by whole body cooling. Our data indicate that cooling therapy improves outcomes of heatstroke by modulating hypothalamic proteome mechanisms.

Protecting against ischaemic stroke in rats by heat shock protein 20-mediated exercise.

BACKGROUND: Exercise preconditioning (EP(+) ) has been widely accepted as a being of safe and effective preventive measure for stroke. The purpose of this study was to investigate whether EP(+) improves outcomes of ischaemic stroke by promoting neuronal and glial expression of heat shock protein (HSP) 20. MATERIALS AND METHODS: Adult male Sprague-Dawley rats (288 in number) were used to investigate the contribution of HSP20-containing neurons and HSP20-containing glial cells in the exercise-mediated neuroprotection in the stroke condition using middle cerebral artery occlusion. RESULTS: Exercise preconditioning, in addition to increasing the numbers of both the HSP20-containg neurons (88 ± 8 vs. 43 ± 4; n = 8 each group; P < 0·05) and the HSP20-containg astrocytes (102 ± 10 vs. 56 ± 5; n = 8; P < 0·05) significantly attenuated stroke-induced brain infarct (140 ± 9 vs. 341 ± 20 mm(3) ; n = 8 per group; P < 0·01), neuronal apoptosis (20 ± 5 vs. 87 ± 7; n = 8 per group; n = 8; P < 0·01), glial apoptosis (29 ± 5 vs. 101 ± 4; n = 8; P < 0·01), and neurological deficits (6·6 ± 0·3 vs. 11·7 ± 0·8; n = 8 per group; P < 0·01). Reducing the numbers of both HSP20-containing neurons and HSP20-contaiing glia by intracerebral injection of pSUPER small interfering RNAί expressing HSP20 significantly reversed the beneficial effects of EP(+) in attenuating stroke-induced cerebral infarct, neuronal and glial apoptosis, and neurological deficits. CONCLUSIONS: The numbers of both the HSP20-containing neurons and the HSP20-containing glia inversely correlated with the outcomes of ischaemic stroke. In addition, preischaemic treadmill exercise improves outcomes of ischaemic stroke by increasing the numbers of both the HSP20-containing neurons and the HSP20-containing glia.

Attenuating systemic inflammatory markers in simulated high-altitude exposure by heat shock protein 70-mediated hypobaric hypoxia preconditioning in rats.

BACKGROUND/PURPOSE: The primary goal of this study was to test whether high-altitude exposure (HAE: 0.9% O(2) at 0.47 ATA for 24 hours) was capable of increasing the systemic inflammatory markers as well as the toxic organ injury indicators in rats, with a secondary goal to test whether preinduction of heat shock protein (HSP) 70 by hypobaric hypoxia preconditioning (HHP: 18.3% O(2) at 0.66 ATA for 5 h/day on 5 days consecutively for 2 weeks) attenuated the proposed increased serum levels of both the systemic inflammatory markers and the toxic organ injury indicators. METHODS: Rats were assigned to: (1) non-HHP (21% O(2) at 1.0 ATA)+non-HAE (21% O(2) at 1.0 ATA) group; (2) non-HHP+HAE group; (3) HHP+non-HAE group; (4) HHP+HAE group; and (5) HHP+HSP70 antibodies (Ab)+HAE group. For the HSP70Ab group, a neutralizing HSP70Ab was injected intravenously at 24 hours prior to HAE. All the physiological and biochemical parameters were obtained at the end of HAE or the equivalent time period of non-HAE. Blood samples were obtained for determination of both the systemic inflammatory markers (e.g., serum tumor necrosis factor-α, interleukin-1ß, E-selectin, intercellular adhesion molecule-1, and liver myeloperoxidase activity) and the toxic organ injury indicators (e.g., nitric oxide metabolites, 2,3-dihydroxybenzoic acid, and lactate dehydrogenase). RESULTS: HHP, in addition to inducing overexpression of tissue HSP70, significantly attenuated the HAE-induced hypotension, bradycardia, hypoxia, acidosis, and increased tissue levels of both the systemic inflammatory markers and the toxic organ injury indicators. The beneficial effects of HHP in inducing tissue overexpression of HSP70 as well as in preventing the HAE-induced increased levels of the systemic inflammatory markers and the toxic organ injury indicators could be significantly reduced by HSP70Ab preconditioning. CONCLUSION: These results suggest that HHP may downgrade both the systemic inflammatory markers and the toxic organ injury indicators in HAE by upregulating tissue HSP70.

Involvement of TG-interacting factor in microglial activation during experimental traumatic brain injury.

Traumatic brain injury (TBI) is a complex injury involving several physiological alterations, potentially leading to neurological impairment. Previous mouse studies using high-density oligonucleotide array analysis have confirmed the upregulation of transforming growth-interacting factor (TGIF) mRNA in TBI. TGIF is a transcriptional corepressor of transforming growth factor beta (TGF-ß) signaling which plays a protective role in TBI. However, the functional roles of TGIF in TBI are not well understood. In this study, we used confocal microscopy after immunofluorescence staining to demonstrate the increase of TGIF levels in the activated microglia of the pericontusional cortex of rats with TBI. Intracerebral knockdown of TGIF in the pericontusional cortex significantly downregulated TGIF expression, attenuated microglial activation, reduced the volume of damaged brain tissue, and facilitated recovery of limb motor function. Collectively, our results indicate that TGIF is involved in TBI-induced microglial activation, resulting in secondary brain injury and motor dysfunction. This study investigated the roles of transforming growth-interacting factor (TGIF) in a traumatic brain injury (TBI)-rat model. We demonstrated the increase of TGIF levels in the activated microglia of the pericontusional cortex of rats with TBI. Intracerebral knockdown of TGIF in the pericontusional cortex of the TBI rats significantly attenuated micoglial activation, reduced the volume of damaged brain tissue, and facilitated recovery of limb motor function. We suggest that inhibition of TGIF might provide a promising therapeutic strategy for TBI.

Beneficial effect of astragalosides on stroke condition using PC12 cells under oxygen glucose deprivation and reperfusion.

Astragalosides (AST) are reported to be neuroprotective in focal cerebral ischemic models in vivo. In this study, the direct effect of AST against oxygen and glucose deprivation (OGD) including neuronal injury and the underlying mechanisms in vitro were investigated. 5 h OGD followed by 24 h of reperfusion [adding back oxygen and glucose (OGD-R)] was used to induce in vitro ischemia reperfusion injury in differentiated rat pheochromocytoma PC12 cells. AST (1, 100, and 200 µg/mL) were added to the culture after 5 h of the OGD ischemic insult and was present during the reoxygenation phases. A key finding was that OGD-R decreased cell viability, increased lactate dehydrogenase, increased reactive oxygen species, apoptosis, autophagy, functional impairment of mitochondria, and endoplasmic reticulum stress in PC12 cells, all of which AST treatment significantly reduced. In addition, AST attenuated OGD-R-induced cell loss through P38 MAPK activation a neuroprotective effect blunted by SB203580, a specific inhibitor of P38 MAPK. Our data suggest that both apoptosis and autophagy are important characteristics of OGD-R-induced PC12 death and that treating PC12 cells with AST blocked OGD-R-induced apoptosis and autophagy by suppressing intracellular oxidative stress, functional impairment of mitochondria, and endoplasmic reticulum stress. Our data provide identification of AST that can concomitantly inhibit multiple cells death pathways following OGD injuries in neural cells.