Effect of acupuncture at different meridian acupoints on changes of related factors for rabbit gastric mucosal injury

AIM： To explore the regularity of multi-meridians controlling a same viscus （MMCSV）. METHODS： The rabbit gastric ulcer model was established by ethanol intragastric instillation. Fifty-six rabbits were randomly divided into normal group, model group （MG）, model plus acupuncture at Foot Yangming Meridian group （YMG）, model plus acupuncture at Foot Taiyin Meridian group （TYG）, model plus acupuncture at Foot Shaoyang Meridian group （SYG）, model plus acupuncture at Foot Jueyin Meridian group （JYG）, model plus acupuncture at Foot Taiyang Meridian group （TYMG）, with eight rabbits in each group. Gastric mucosal nitric oxide （NO） and nitric oxide synthase （NOS） were assayed by the nitric acid reductase method, and prostaglandin E2 （PGE2） and epidermal growth factor （EGF） were measured by radioimmunoassay. The comprehensive effects were analyzed by weighing method. RESULTS： Compared to MG, SYG, JYG and TYMG, the rabbits gastric mucosal injury index （GMII） reduced very significantly in YMG （P〈0.01）. Compared to MG, the GMII also reduced significantly in TYG （P〈0.05）. NO, NOS, PGE2 and EGF increased very significantly in YMG （P〈0.01）. The EGF in YMG also increased significantly than that in TYG compared to those in MG, SYG, JYG and TYMG （P〈0.05）. The PGE2 and EGF also increased very significantly in TYG than those in MG, JYG and TYMG （P〈0.01）. While compared to SYG, the NOS increased significantly in TYG （P〈0.05）. NOS was the highest in YMG （P〈0.01）, and was higher in TYG than in MG （P〈0.01）. CONCLUSION： MMCSV is common. The Foot Yangming Meridian is most closely related to the stomach, followed by Foot Taiyin Meridian, Foot Shaoyang Meridian and Foot Jueyin Meridian. Foot Taiyang Meridian has no correlation with the stomach.

Breviscapine reduces neuronal injury caused by traumatic brain injury insult:partly associated with suppression of interleukin-6 expression

Breviscapine,extracted from the herb Erigeron breviscapus,is widely used for the treatment of cardiovascular diseases,cerebral infarct,and stroke,but its mechanism of action remains unclear.This study established a rat model of traumatic brain injury induced by controlled cortical impact,and injected 75 μg breviscapine via the right lateral ventricle.We found that breviscapine significantly improved neurobehavioral dysfunction at 6 and 9 days after injection.Meanwhile,interleukin-6 expression was markedly down-regulated following breviscapine treatment.Our results suggest that breviscapine is effective in promoting neurological behavior after traumatic brain injury and the underlying molecular mechanism may be associated with the suppression of interleukin-6.

Endovascular Stents in Arterial Injury after Radiotherapy

We evaluated preliminary success and patency of stenting for the treatment of radiation - induced arterial diseases. Thirteen stents were placed in 8 patients to treat occlusion (n = 3), aneurysm (n = 1), residual stenosis (n = 2), multiple stenoses (n = l), and delayed restenosis after previous balloon angioplas-ty (n=l). Interventional procedure was successfully performed in 8 patients for their arterial lesions after radiotherapy. Six patients underwent interventional procedure once or twice. Two patients underwent PTA 4 times. Five of these patients demonstrated primary patency with relief of clinical symptoms with a mean follow-up of 2 years (range: 8 - 60 months). Clinical improvement was noted in the other patients. Our results suggest that stent placement by single or multiple techniques may have immediate effect on arterial lesions caused by radiation and can be considered as a therapeutic option of choice in these cases.

Protective Effects of Shikonin on Brain Injury Induced by Carbon Ion Beam Irradiation in Mice

Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed protective effect on cerebral ischemic injury. Here we investigated the effects of shikonin on carbon ion beam induced radiation brain injury in mice. Pretreatment with shikonin significantly increased the SOD and CAT activities and the ratio of GSH/GSSG in mouse brain tissues compared with irradiated group （P〈0.01）, while obviously reduced the MDA and PCO contents and the RO$ levels derived from of the brain mitochondria.

Age-at-injury effects of microglial activation following traumatic brain injury： implications for treatment strategies

Traumatic brain injury（TBI）remains one of the leading causes of disability and death in infants and children.Studies have demonstrated that the youngest age group（especially≤4 years old）exhibit worse functional outcome following moderate to severe TBI compared to older children or adults（Anderson et al.,2005;Emami et al.,2017）.These data suggest that age-at-injury may be an important determinant of outcome,

Protective effect of melatonin on neurons after oxidative-stress injury

BACKGROUND:It has been suggested that melatonin(MT)can protect secondary neuronal injury.However,the protective effect of MT on neuronal injury in ischemia/reperfusion models in vitro still has not been proved.OBJECTIVE:To investigate the protective effect of MT on central ischemic injury of nerve cells and analyze its possible mechanism.DESIGN:Contrast observational study.SETTING:Department of Biochemistry and Molecular Biology,Tongji Medical College,Huazhong University of Science and Technology.MATERIALS:Rats aged 7-8 days and weighing 10-12 g were provided by Medical Experimental Animal Center,Tongji Medical College,Huazhong University of Science and Technology.MT was provided by Sigma Company,USA.METHODS:The experiment was carried out in the Laboratory of Biochemistry and Molecular Biology,Tongji Hospital,Huazhong University of Science and Technology from October 2002 to March 2004.The effects of MT on the neurodegeneration induced by oxygen-glucose-deprivation(OGD)were tested in cultured rat cerebellar granule cells.Neuron damage was quantitatively assessed by Typan Blue exclusion and MTT assay at different time points after oxygen-glucose-deprivation(90 minutes).DNA gel electrophoresis and acridine orange stain were performed to determine the nature of cell damage.And fluorescence spectrophotometer was used for quantification of intracellular malondialdehyde(MDA)at various time intervals.MAIN OUTCOME MEASURES:Correlation between degrees of neuronal injury and reperfusion times,apoptosis,and production of MDA in cells.RESULTS:①The neuron injury was aggravated with reperfusion time.②The protective effect of MT was time-and dose-dependent when its concentration was not higher than 10μmol/L.③When neurons were exposed to OGD for 90 minutes,part of the cells exhibited typical features of apoptosis:internucleosomal DNA condensation and DNA ladder on agarose gel electrophoresis.MT added to cells recovering from OGD exerted neuroprotective action against OGD-induced apoptosis.④In OGD exposed cultures,the production of MDA burst 12 hours after OGD,while MT significantly decreased the generation of MDA(P<0.05)in a time-dependent manner.CONCLUSION:MT may have therapeutic potential in the prevention and treatment of ischemic/hypoxic neuronal damage,and this neuroprotective action may contribute to the antioxidant nature of MT.

Changes of norepinephrine and tumor necrosis factor in submandibular gland of rats with sympathetic nerve injury and the protective effect of 17 beta-estradiol

BACKGROUND： Recent researches have indicated that estrogen has extensive neuroprotective effects. So some studies designed ovariectomized animal models and administrated with estrogen, so as to verify its neuroprotective effects. OBJECTIVE： To observe the effect of 17 beta-estradiol on the content of norepinephrine （NE） and level of tumor necrosis factor （TNF） in submandibular glands of rats with sympathetic nerve injury, and analyze the dose-dependence and pathway of action. DESIGN： A randomized control animal study SETTINGS： Department of Hand Surgery, the 252 Hospital of Chinese PLA; Department of Hand Surgery Union Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology. MATERIALS： Fifty healthy female Wistar rats were randomly divided into 5 groups with 10 rats in each group： sham-operated group, ovariectomy＋6-OHDA＋saline group, ovariectomy＋6-OHDA＋17β-estradiol 50, 200 and 500 μg/kg groups. METHODS： The experiments were carried out in Tongji Medical College, Huazhong University of Science and Technology between October 2005 and March 2006. Bilateral ovaries were only exposed but not resected for the rats in the sham-operated group, but bilateral ovaries were resected in all the other groups. In the ovariectomy＋6-OHDA＋176-estradiol 50, 200 and 500 μg/kg groups, the rats were administrated with intraperitoneal injection of 6-OHDA （8 mg/kg）, and then immediately given 176-estradiol of corresponding dosages respectively, once a day for 10 days continuously. Rats in the sham-operated group and ovariectomy＋6-OHDA＋saline group were administrated with saline of the same volume. After administration, 5 rats in each group were killed to determine the NE contents in bilateral submandibular glands with high performance liquid chromatography-electrochemical detector （HPLC-ECD）, and the other 5 rats were used to determine the TNF levels in submandibular glands with enzyme-linked immunosorbant assay. MAIN OUTCOME MEASURES： The NE contents and TNF levels in submandibular glands of rats in each group were observed. RESULTS： All the 50 rats were involved in the analysis of results. （1） The NE content was obviously lower in the ovariectomy＋6-OHDA＋saline group than in the sham-operated group [（1 035±196）, （1 823±314） ng/g, P 〈 0.05], there were no significant differences between the ovariectomy＋6-OHDA＋17β-estradiol 50 μg/kg group and ovariectomy＋6-OHDA＋saline group [（1 004±253）, （1 035±196） ng/g, P 〉 0.05], but obviously higher in the ovariectomy＋6-OHDA＋17β-estradiol 200 and 500 μg/kg groups than in the ovariectomy＋6-OHDA＋saline group [（1 487±268）, （1 939±274）, （1 035±196） ng/g, P 〈 0.05]. （2） The TNF level was obviously higher in the ovariectomy＋6-OHDA＋saline group than in the sham-operated group [（3.498±0.792）, （1.893±0.533） ng/g, P 〈 0.05], there were no significant differences between the ovariectomy＋ 6-OHDA＋17β-estradiol 50 μg/kg group and ovariectomy＋6-OHDA＋saline group [（3.328 ±0.712）, （3.498±0,792） ng/g, P 〉 0.05], but obviously lower in the ovariectomy＋6-OHDA＋17β-estradiol 200 and 500 μg/kg groups than in the ovariectomy＋6-OHDA＋saline group [（2.639±0.438）, （2.016±0.619）, （3.498＋0.792） ng/g, P 〈 0.05]. CONCLUSION： Estrogen has obvious protective effect dose-dependently on 6-OHDA induced chemical sympathetic nerve terminal injury in rats, and it may play its protective role by reducing TNF level and ameliorating inflammatory reaction.

Phycocyanin for protecting brain ischemia-reperfusion injury and its effect on the expression of Caspase-3 mRNA

BACKGROUND ; Phycecyanin can anti-oxidize and clear free radial. Whether its protective effect on brain is related to Caspase-3, the promoter and operator of apoptosis, is highly concerned. OBJECTIVE： To observe phycocyanin for protecting nerve function and reducing the size of cerebral infarction of rats with brain ischemia-reperfusion and its effect on the expression of Cespese-3 mRNA. DESIGN ： A randomized controlled experiment. SETTING ： Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University MATERIALS： Totally 84 adult healthy female Wistar rats, weighing 210 to 250 g, of clean grade, were provided by the Animal Experimental Center of Shandong University. Phycocyanin （Institute of Oceanography of Chinese Academy of Sciences） was used. METHODS： This experiment was carried out in the Key Laboratory for Prevention and Treatment of Brain Diseases during May to December 2005. ① The rats were randomized into sham-operation group （n=4）, control group （n=-40） and phycocyanin-treated group （n=-40）. Middle cerebral artery occlusion/reperfusion （MACO/R） models were created on the rats of control and phycocyanin-treated groups with suture-occluded method by inserting a thread into left side extemal-internal carotid artery. In the sham-operatien group, inserting suture was omitted. After ischemia for 1 hour and reperfusion for 2 hours, suspension of phycocyanin was intragastdcaUy administrated into the rats of the phycocyanin-treated group at 100 mg/kg , and the same volume of normal saline was isochrenously administrated into the rats of control group as the same. ② Six rats were chosen respectively from the control group and phycocyanin-treated group, then neurologic impairment degrees of rats were evaluated according to Bederson＇s grading. ③ Six rats were chosen respectively from the control and phycocyanin-treated groups. The isolated brain tissue was stained with tdphenyltetrazolium chloride, and then the size of cerebral infarction was calculated with HPIAS-1000 image analytical system by calculating the ratio of cerebral infarction size at each layer and contralateral hemisphere size of the same layer. ④ Twenty--eight rats were chosen respectively from the control and phycocyanin-treated groups, Brain tissue was harvested at reperfusion for 6,12,24 hours and for 2,3,7 and 14 days after ischemia for 1 hour, respectively, 4 rats at each time point. Brain tissue of 4 rats of sham-opera- tion group was harvested at the 24^th hour after operation. Brain tissue sections were performed in situ hybridization detection of Cespase-3 mRNA. MAIN OUTCOME MEASURES： Comparison of neurologic impairment degree, cerebral infarction size and the expression of brain tissue Caspase-3 mRNA of rats between two groups RESULTS： Totally 84 rats entered the stage of result analysis. ① Bederson＇s scores at ischemia and reperfusion for 24 and 48 hours were significantly lower in the phycocyanin-treated group than in the control group（P 〈 0.05）. ② After brain ischemia and reperfusion, the infarction area was the largest in the 3^rc layer in both control and phycocyanin-treated group, which was（25.23±0,47）% and（23.09±120） %, respectively, and the size of infarction area in the 2^nd layer to the 5^th layer was significantly smaller in the phycocyanin-treated group than in the control group （P 〈 0.05）. ③Positive cell counts of brain tissue Caspase-3 mRNA： The number of positive cells of Caspase-3 mRNA of control group was increased from cerebral ischemia and reperfusion 6 hours, reached the peak at ischemia and reperfusion 24 hours, began to decrease 2 days later and positive cells of Caspese-3 mRNA were still expressed on the 14^th day after reperfusion. At ischemia and reperfusion 6,12 and 24 hours as well as 2,3,7 and 14 days, positive cell counts of Caspase-3 at peripheral ischemic area were significantly lower in the phycocyanin-treated greup[（70.67 ±3.65）, （85.06±4.79）, （119.54±5.37）,（74.26±2.19）, （62.06±3.34）, （23.11±1.89）, （10.75±2.63）/visual field] than in the control group [（94.38±8 28）, （108.81 ±16.11）, （140.88±14.47）, （98.13±11.31）, （81.03±9.31）, （31.22±8.86）, （16.06±5.96）Nisual field] （ P 〈 0.05）; and those at central ischemic area were also significantly lower in the phycocyanin-treated group [（33.86±4.01）, （39.51±3.46）, （50.96 ±2.53）, （43.07±4.09）, （36.25 ±3.72）, （9.03±3.87）, （4.91±5.59）/visual field ]than in the control group [（51.35±2.13）, （54.87±3.42）, （61.77±4.94）, （55.69±6.06）, （49.01 ±5.73） ,（12.84±3.37）, （7.32±2.39）/visual field]（P 〈 0.05）. CONCLUSION ： Phycocyanin can obviously improve the neurologic function, reduce the size of brain infarction and down-regulate the expression of Caspase-3 mRNA of rats with ischemia and reperfusion injury, thus protect brain.

The neural butterfly effect The injury to peripheral nerves changes the brain

Regeneration of damaged innervations in the peripheral nervous system （PNS） has been well documented in both animals and human. After injury, the damaged neurite swells and undergoes retrograde degeneration. Once the debris is cleared, it begins to sprout and restore damaged connections. Damaged axons are able to regrow as long as the perikarya are intact and have made contact with the Schwann cells in the endoneurial channel[2]. Under appropriate conditions,

Effects of NG-nitro-L-arginine on focal cerebral ischemic injury in rats

BACKGROUND： Previous researches have proved that aminoguanidin can cure cerebral ischemic injury remarkably as a selective induced nitricoxide synthase （iNOS） inhibitor. However, whether nonselective NOS inhibitor could protect cerebral ischemic injury or not is unclear. OBJECTIVE： To investigate the effects of NG-nitro-L-arginine （L-NA）, a nonselective nitricoxide synthase （NOS） inhibitor, on cerebral ischemic injury of rats and the possible mechanism.DESIGN： Randomized controlled study.SETTING ： Pharmacological Department of Medical Academy of Science of Hebei Province.MATERIALS： A total of 56 male healthy SD rats, of grade Ⅱ, weighting 250-290 g, were provided by the Experimental Animal Center of Hebei Province （certification： 04036）. METHODS： The experiment was completed in the Pharmacological Department of Medical Academy of Science of Hebei Province from March 2005 to January 2006.① Grouping： Rats were randomly divided into 3 groups： sham operation group （n=8）, model group （n=24） and L-NA group （n=24）.② Modeling： Middle cerebral artery （MCA） was established on rats in model group and L-NA group with intreluminal line occlusion methods, and rats in sham operation group were separated their external carotid arteries without occlusion of internal carotid artery. ③ Intervention study： Rats in model group and L-NA group were injected intreperitoneally with 10 mL/kg and 20 mg/kg L-NA at 2, 6 and 12 hours respectively after ischemia twice a day for 3 consecutive days. ④ Rats were sacrificed on the third day for measuring volume of cerebral infarction with image analysis and swelling degrees and activities of mitochondria with electron microscope. Effect of L-NA on ultrastructural changes of neurons in cortex was observed after ischemia. MAIN OUTCOME MEASURES：① Volume of cerebral infarction; ②Swelling degrees, contents of nitric oxide （NO） and malondialdehyde （MDA） and activities of adenosine triphosphatase （ATPase）, superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） in mitochondria;③ Ultrastructural changes of mitochondria in brain tissue after cerebral ischemia. RESULTS： ① At 12 hour after ischemia, volume of cerebral infarction in L-NA group was lower than that in model group （P 〈 0.01）. ② Content of NO in mitochondria in L-NA group was decreased as compared with that in model group at 2, 6 and 12 hours after ischemia （P 〈 0.05）; swelling degree of mitochondria in brain tissue was relieved in L-NA group at 12 hour after ischemia, and content of MDA was decreased （P 〈 0.05）; mitochondrial activity in L-NA group was increased at 12 hour after ischemia, and activities of ATPase, SOD and GSH-Px in mitochondria were increased （P 〈 0.05）.③ Degrees of mitochondrial injury in brain tissue were relieved in L-NA group at 12 hour after ischemia as compared with those in model group and L-NA group at 2 and 6 hours after ischemia. CONCLUSION ： ①L-NA can beneficially inhibit NO production, but not protect brain against damage in ischemia acute stage. ②L-NA might have protective effects on cerebral injury through inhibiting the production of oxygen free radical, increasing antioxidation, ameliorating energy metabolism, beneficially improving the integrity of form and function of mitochondria in brain tissue during postischemia in rats.

Protective effect of hydrogen-rich saline on liver ischemia-reperfusion injury in mice

Objective To explore protective effect of hydrogen - rich saline on liver ischemia reperfusion ( IR) in mice and possible mechanisms. Methods Twenty - four C57BL /6 mice were randomly divided into 3 groups: sham - operated group,control group ( mice were injec-

Effects of combined radiation and thermal burn injury on the survival of skin allograft and immune function in rats

Abstract Objectives To investigate the effects of combined radiation and thermal burn injury on the survival of skin allografts and to analyze the relationship between the prolongation of allograft survival and the changes of immune functions of the thymocytes and splenocytes in rats. Methods Wistar rats were irradiated with 3, 4, 5, 6 and 8 Gy of gamma rays. Thirty minutes after radiation, 15% TBSA Ⅲ degree burn was inflicted to the rats. Twenty four hours after the burn injury, allografts were used to cover the burn wounds. In the 8 Gy group, 1 hour before skin grafting, the bone marrow cells (4×10 8) from the same donor were also transplanted. All rats were carefully observed after injury. The rats with single radiation injury of 5 Gy gamma rays, with single burn injury and with combined radiation burn injury were killed 3, 7, 10, 15 and 30 days after skin grafting for immunological assay and pathological study. Results All the allografts in the single burn group were rejected in 10 days. In the combined injury groups, the survival rates of the allografts in rats undergoing 3 and 4 Gy radiation were 20% and 30%, respectively. In the combined injury groups undergoing 5, 6 and 8 Gy radiation, the 10 day survival rates of the allografts were 69%, 88% and 100% respectively, and the 30 day survival rates in the three groups were 36%, 42% and 100% separately. The grafted allogenic skin, with normal epithelial cells and good vascularity, healed well with the recipient's skin. Hairs grew well from the allografts 30 days after grafting. Three, 7 and 15 days after allografting, in the single burn group, the proliferative activities of the thymocytes were 90%, 185% and 130% of the preinjury level, and the antibody forming capacities of the splenocytes were 200%, 171% and 300% of the preinjury level, respectively; in the combined injury groups, the proliferative activities were 6%, 99% and 91% of the preinjury level, and the forming capacities were 2%, 36% and 90% of the preinjury level. Conclusions The survival rate of allograft in rats undergoing combined radiation and thermal burn injury rises with the increase in radiation dosage. The allograft covering single bun injury is severely rejected by immune reaction. The prolongation of the survival of allograft in combined injury group mainly results from radiation that suppresses immune functions.

EFFECT OF WARM ISCHEMIC INJURY ON MORPHOLOGY AND VIABILITY OF AORTIC VALVES IN RATS

Warm ischemia is one of the most important causes of valvular damage from death of donor to its valve harvesting. This study aimed at using qualitative and quantitative methods to characterize warm ischemic injury through models of SD rat's aortic valves and design to show the relationship among ultrastructural, biological and biochemical changes concerning with the length of warm ischemia time (WIT). 102 harvested SD rat's aortic valves were divided into 6 groups of different ischemic time for this study. 432 photomicrographs of transmission electron microscopy (TEM) were put into computer for analysis. The volume ratio of nucleus to plasma in cells (Vnp) and the ratio of extramembrane area to volume of mitochondria (S / V) were used to characterize the degree of valvular cell injuries. Valvular cells culture and biochemical metabolism including glucose degredation and H-3-TdR absorption rate were adopted. The valvular cells depicted a significant decrease and H-3-TdR taking-up also being inhibited under the influence of prolonged WIT.

Effects of Astragaloside in Treating Myocardial Injury and Myocardial Sarco/Endoplasmic Ca^( 2+)-ATPase of Viral Myocarditis Mice

Objective: To investigate the effects on myocardial injury and sarcoplasmic reticulum (SR) Ca^2+-ATPase of viral myocarditis mice treated with Astragaloside (AS) and Astragalus Injection (AI). Methods: Viral myocarditis model was created by intraperitoneal inoculation with coxsackievirus B 3m (CVB 3m ) solution and were divided into model, AS, AI and normal control groups. The mortality, myocardial pathological changes, serum cardiac troponin I (cTnI) and the activity of myocardial Sarco/Endoplasmic Ca 2+ ATPase (SERCA) were observed. Results: The mortality of model was higher than that of the normal control (P=0.0042), AS and AI (P<005). The serum level of cTnI of model was significantly higher than that of the normal control (P<0001), AS (P<0025) and AI (P<005). The myocardial necrosis and inflammatory changes of AS and AI groups were alleviated than that of model (P<001). The activity of myocardial SERCA of model were significantly lower than that of normal control (P<0001), AS (P<001) and AI (P<005). Conclusions: AS and AI have some protecting effects on myocardial injury of viral myocarditis mice. AS is the effective component of Astragalus membranaceus in treating viral myocarditis. One of the mechanisms of Astragalus membranaceus and AS for viral myocarditis mice depriving of the myocardial injury may be due to improve the activity of myocardial SERCA in the mice.

Effects of hydration in contrast-induced acute kidney injury after primary angioplasty a randomized,controlled trial

Background Intravascular volume expansion represents a beneficial measure against contrast-induced acute kidney injury （CI-AKI） in patients undergoing elective angiographic procedures. However, the efficacy of this preventive strategy has not yet been established for patients with ST-elevation-myocardial infarction （STEMI）, who are at higher risk of this complication after primary percutaneous coronary intervention （PCI）. In this randomized study we investigated the possible beneficial role of periprocedural intravenous volume expansion and we compared the efficacy of 2 different hydration strategies in patients with STEMI undergoing primary PCI.

Effect of acute kidney injury on short-and long-term mortality of patients with acute myocardial infarction

Objective To evaluate the role of acute kidney injury(AKI)in predicting early(30-day)and late(30-day to5-year)mortality of acute myocardial infarction(AMI)patients during hospitalization.Methods A total of 1371adult patients diagnosed with AMI in the First People’s Hospital of Changzhou from January 2008 to December2012 were analyzed retrospectively while their

Particulate matter(PM(2.5)) exposure season-dependently induces neuronal apoptosis and synaptic injuries

Epidemiological studies have shown that particulate matter 2.5（PM（2.5）） not only increases the incidence of cardiopulmonary illnesses but also relates to the development of neurodegenerative diseases. Considering that PM（2.5）is highly heterogeneous with regional disparity and seasonal variation, we investigated whether PM（2.5）exposure induced neuronal apoptosis and synaptic injuries in a season-dependent manner. The results indicated that PM（2.5）altered the expression of apoptosis-related proteins（mainly bax and bcl-2）, activated caspase-3 and caused neuronal apoptosis. Additionally, PM（2.5）decreased the levels of synaptic structural protein postsynaptic density（PSD-95） and synaptic functional protein N-methyl-D-aspartate（NMDA） receptor subunit（NR2B） expression. These effects occurred in a season-dependent manner, and PM（2.5）collected from the winter showed the strongest changes. Furthermore, the effect was coupled with the inhibition of phosphorylated extracellular signal-regulated kinase 1/2（p-ERK1/2） and phosphorylated c AMP-response element binding protein（p-CREB）. Based on the findings, we analyzed the correlations between the chemical composition of PM（2.5）samples and the biological effects, and confirmed that winter PM（2.5）played a major role in causing neuronal apoptosis and synaptic injuries among different season samples.