Neuroprotection of Dexmedetomidine against Cerebral Ischemia-Reperfusion Injury in Rats: Involved in Inhibition of NF-κB and Inflammation Response

Wang, Lijun,Liu, Haiyan,Zhang, Ligong,Wang, Gongming,Zhang, Mengyuan,Yu, Yonghui The Korean Society of Applied Pharmacology 2017 Biomolecules & Therapeutics(구 응용약물학회지) Vol.25 No.4

Dexmedetomidine is an ${\alpha}2$-adrenergic receptor agonist that exhibits a protective effect on ischemia-reperfusion injury of the heart, kidney, and other organs. In the present study, we examined the neuroprotective action and potential mechanisms of dexmedetomidine against ischemia-reperfusion induced cerebral injury. Transient focal cerebral ischemia-reperfusion injury was induced in Sprague-Dawley rats by middle cerebral artery occlusion. After the ischemic insult, animals then received intravenous dexmedetomidine of $1{\mu}g/kg$ load dose, followed by $0.05{\mu}g/kg/min$ infusion for 2 h. After 24 h of reperfusion, neurological function, brain edema, and the morphology of the hippocampal CA1 region were evaluated. The levels and mRNA expressions of interleukin-$1{\beta}$, interleukin-6 and tumor nevrosis factor-${\alpha}$ as well as the protein expression of inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-${\kappa}Bp65$, inhibitor of ${\kappa}B{\alpha}$ and phosphorylated of ${\kappa}B{\alpha}$ in hippocampus were assessed. We found that dexmedetomidine reduced focal cerebral ischemia-reperfusion injury in rats by inhibiting the expression and release of inflammatory cytokines and mediators. Inhibition of the nuclear factor-${\kappa}B$ pathway may be a mechanism underlying the neuroprotective action of dexmedetomidine against focal cerebral I/R injury.

Granulation of Activated Sludge in a Continuous Flow Airlift Reactor by Strong Drag Force

Dandan Zhou,Mengyuan Liu,Jun Wang,Shuangshi Dong,Ning Cui,Linlin Gao 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2

Most aerobic granule cultivation has been based on the sequencing batch reactor (SBR) and then the factors that affect aerobic granulations were developed in the SBR. However, little work has been done to cultivate aerobic granules in a continuous-flow bioreactor with simple structure that is realistic for engineering. This work is the first to cultivate aerobic granules in a continuous flow airlift fluidized bed reactor (CAFB) possesses a very simple structure and without settling time and starvation time controlling. The configuration of CAFB was the simplest continuous-flow aerobic granular bioreactor reported by now. The majority of granules could be formatted in the CAFB after 12 days cultivation. The effluent COD concentration maintained at 50 ± 10 mg/L for the variable COD loading rate of 3.5 g COD/L/d and 4.8 g COD/L/d, which confirmed that the CAFB performed good anti-shock abilities. CAFB performed good nitrification ability, however, little denitrification was found under the operating conditions of this study. The shear stress acting on the solid phase were hundreds of times stronger in the CAFB than in the SBR at the same aeration strength. It seems CAFB is very efficient for granulation due to the strong shear-force exertion,which is promising for continuous-flow aerobic granular bioreactor. Protein, positive to the hydrophobicity, was predominant in extracellular polymeric substances in the granules, and favored the granules formation in the CAFB combined with the polysaccharides. However, filamentous bulking always happened in 35 days operation of the CAFB, thus further study on the stability of this bioreactor is urgently necessary.

Enhanced photoluminescence from KCl flux assisted Eu3+ doped CaTiO3 red phosphor for temperature sensing

Xiuying Tian,Lei Li,Mengyuan Wei,Changyan Ji,Zhi Huang,Xin Liu,Jin Wen,Yangxi Peng 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.5

CaTiO3: Eu3+ red phosphors with high thermal stability and temperature sensitivity were synthesized by KCl flux assisted solidphase reaction method and they had orthorhombic perovskite phase. CaTiO3:15%Eu3+ had the irregular particle structure,with mean particle size of about 1.58 μm, while CaTiO3:15%Eu3+ +6%KCl also had the irregular particle structure, with meanparticle size of about 2.25 μm. When Eu3+ ion concentration was 15mol%, concentration quenching phenomenon took place,which could be explained by electric dipole-dipole interaction due to the critical Eu3+- Eu3+ distance of ~ 8.93 Å. We found thatKCl flux could increase the particle size and crystallinity, which was beneficial to luminescence property. Based on the PLspectra excited at 398 nm, the color coordinates of CaTiO3:15%Eu3+ were (0.5911, 0.4008) and the color purity was 97.7%,while the color coordinates of sample CaTiO3:15%Eu3++ 6%KCl were (0.6042, 0.3895) and the color purity was 98.4%. Therelative intensity IR1 and IR2 at 423 K is 87. 29% and 83. 22%, indicating the sample had high thermal stability. Based on TCLsFIR, Sr of CaTiO3:15%Eu3+ is 2322.67/T^2. CaTiO3:Eu3+ red phosphor was expected to be a promising inorganic material forpossible applications in temperature sensing.

The characteristic analysis of the operational overvoltage caused by the vacuum circuit breakers on High-speed trains

Xiao Song,Tong Mengyuan,Rao Yang,Li Yuhang,Ye Zhizong,Shen Yixiang,Hou Hao,Gao Guoqiang,Wu Guangning,Jin Yaoyao,Zhou Jie,Liu Jie 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.1

Along with the operating velocity and traction power increasing continuously, the issue related to the safety and reliability of the high-voltage traction power system for high-speed trains have gradually been exposed during the practical service process. When the train passes a neutral section settled roughly per 15 km between two neighboring substations, the on-board vacuum circuit breaker (VCB) must to be operated for changing the input powers with diff erent phases. At the moment of switching on or off the VCB, the arc between the contacts in the arc-extinguishing chamber may be triggered, which tends to result in the operational overvoltage. Due to numerous inductances and capacitances existing in the traction power supply system, the overvoltage may lead to high-frequency electromagnetic oscillation spreading along the transmission routes. The on-board high-voltage equipments within the power supply system may suff er from the impulse brought from the VCB operational overvoltage frequently, which is possible to cause the insulation aging or breakdown issue. To investigate the characteristic of the operational overvoltage of VCBs, a ‘train-rail-catenary’ power supply model is built based on the measured impedance parameters, which has been verifi ed by the experimental tests. The generating mechanism with the infl uence factors of the operational overvoltage when switching on or off the VCB has been explored, meanwhile the distribution of the train body overvoltage on each carriage has also been presented.

Mechanical overload-induced release of extracellular mitochondrial particles from tendon cells leads to inflammation in tendinopathy

Chen Ziming,Li Mengyuan,Chen Peilin,Tai Andrew,Li Jiayue,Bassonga Euphemie Landao,Gao Junjie,Liu Delin,Wood David,Kennedy Brendan F.,Zheng Qiujian,Zheng Ming H. 생화학분자생물학회 2024 Experimental and molecular medicine Vol.56 No.-

Tendinopathy is one of the most common musculoskeletal diseases, and mechanical overload is considered its primary cause. However, the underlying mechanism through which mechanical overload induces tendinopathy has not been determined. In this study, we identified for the first time that tendon cells can release extracellular mitochondria (ExtraMito) particles, a subtype of medium extracellular particles (mEPs), into the environment through a process regulated by mechanical loading. RNA sequencing systematically revealed that oxygen-related reactions, extracellular particles, and inflammation were present in diseased human tendons, suggesting that these factors play a role in the pathogenesis of tendinopathy. We simulated the disease condition by imposing a 9% strain overload on three-dimensional mouse tendon constructs in our cyclic uniaxial stretching bioreactor. The three-dimensional mouse tendon constructs under normal loading with 6% strain exhibited an extended mitochondrial network, as observed through live-cell confocal laser scanning microscopy. In contrast, mechanical overload led to a fragmented mitochondrial network. Our microscopic and immunoblot results demonstrated that mechanical loading induced tendon cells to release ExtraMito particles. Furthermore, we showed that mEPs released from tendon cells overloaded with a 9% strain (mEP9%) induced macrophage chemotaxis and increased the production of proinflammatory cytokines, including IL-6, CXCL1, and IL-18, from macrophages compared to mEP0%, mEP3%, and mEP6%. Partial depletion of the ExtraMito particles from mEP9% by magnetic-activated cell sorting significantly reduced macrophage chemotaxis. N-acetyl-L-cysteine treatment preserved the mitochondrial network in overloaded tendon cells, diminishing overload-induced macrophage chemotaxis toward mEP9%. These findings revealed a novel mechanism of tendinopathy; in an overloaded environment, ExtraMito particles convey mechanical response signals from tendon cells to the immune microenvironment, culminating in tendinopathy.

Neuroprotection of Dexmedetomidine against Cerebral Ischemia-Reperfusion Injury in Rats: Involved in Inhibition of NF-κB and Inflammation Response

( Lijun Wang ),( Haiyan Liu ),( Ligong Zhang ),( Gongming Wang ),( Mengyuan Zhang ),( Yonghui Yu ) 한국응용약물학회 2017 Biomolecules & Therapeutics(구 응용약물학회지) Vol.25 No.4

Dexmedetomidine is an α2-adrenergic receptor agonist that exhibits a protective effect on ischemia-reperfusion injury of the heart, kidney, and other organs. In the present study, we examined the neuroprotective action and potential mechanisms of dexmedetomidine against ischemia-reperfusion induced cerebral injury. Transient focal cerebral ischemia-reperfusion injury was induced in Sprague-Dawley rats by middle cerebral artery occlusion. After the ischemic insult, animals then received intravenous dexmedetomidine of 1 mg/kg load dose, followed by 0.05 mg/kg/min infusion for 2 h. After 24 h of reperfusion, neurological function, brain edema, and the morphology of the hippocampal CA1 region were evaluated. The levels and mRNA expressions of interleukin-1b, interleukin-6 and tumor nevrosis factor-α as well as the protein expression of inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-κBp65, inhibitor of κBα and phosphorylated of κBα in hippocampus were assessed. We found that dexmedetomidine reduced focal cerebral ischemia-reperfusion injury in rats by inhibiting the expression and release of inflammatory cytokines and mediators. Inhibition of the nuclear factor-κB pathway may be a mechanism underlying the neuroprotective action of dexmedetomidine against focal cerebral I/R injury.

Dynamics of fungal community during silage fermentation of elephant grass (Pennisetum purpureum) produced in northern Vietnam

Viet Ha Vu,Xiyang Li,Mengyuan Wang,Rongmei Liu,Guojian Zhang,Wei Liu,Baixue Xia,Qun Sun 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.7

Objective: This study aimed to gain deeper insights into the dynamic changes in spoilage fungi populations during fermentation and the influence of traditional additives on silage quality. Methods: Elephant grass (Pennisetum purpureum) was prepared without any additive (control), and with the addition of 0.5% salt, and 0.5% salt–0.2% sugar mixture. The fungal community was then determined using a classic culturing method and high-throughput sequencing at 0, 5, 15, and 60 days after ensiling. Results: The results showed that the fungal community of elephant grass silage varied significantly between the natural fermentation without any additive and the two additive groups. The diversity and relative abundance of spoilage molds in the control group were much higher than those in the two treatment groups (p<0.05). Three species of yeasts (Candida sp., Pichia sp., Trichosporon sp.) and four spoilage molds (Fusarium sp., Aspergillus sp., Muco sp. and Penicillin sp.) were the predominant fungi in elephant grass during natural fermentation from 0 to 60 days, which were found to be significantly decreased in salt and sugar additive groups (p<0.05). Meanwhile, the diversity and relative abundance of undesirable molds in the 0.5%-salt additive group were the lowest among all groups. Conclusion: Adding salt and sugar, particularly 0.5% salt, is a promising effective approach to reduce the amount of undesirable fungi thus, improving the silage quality of elephant grass in northern Vietnam.

Age quadratically affects intestinal calcium and phosphorus transporter gene expression in broiler chickens

Lv, Xianliang,Hao, Junfang,Wu, Lihua,Liu, Mengyuan,He, Lei,Qiao, Yingying,Cui, Yanyan,Wang, Guan,Zhang, Chunmei,Qu, Hongxia,Han, Jincheng Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.12

Objective: This research aimed to evaluate the effects of age on growth, tibia development, and intestinal calcium (Ca) and phosphorus (P) transporter gene expressions in broiler chickens. Methods: A total of 224 male Arbor Acres broilers were fed with nutrient-adequate diets and reared in eight cages (28 broilers per cage). Eight broilers (one broiler per cage) were selected and killed at 5, 10, 15, 20, 25, 30, 35, and 40 days of age, respectively. Results: Body weight continuously increased with age of broiler chickens from 5 to 40 days. The bone weight, ash weight, diameter, and length of the tibia also increased with broiler age. By contrast, the tibia ash, Ca, and P percentages quadratically changed with age (p<0.001), and the highest values of mineral contents were observed at 20, 25, and 25 days of age, respectively. The mRNA abundances of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), and plasma membrane ATPase 1b (PMCA1b) increased from 5 to 25 days and then decreased up to 40 days. Similar results were noted in the mRNA abundances of IIb sodium-phosphate cotransporter (NaPi-IIb), inorganic phosphate transporter 1 (PiT-1), inorganic phosphate transporter 2 (PiT-2), nuclear vitamin D receptor (nVDR), and membrane vitamin D receptor (mVDR). The mRNA abundances of Ca and P transporters and VDRs were the highest at 25 days of age. Conclusion: These data indicate that age quadratically affects intestinal Ca and P transporter gene expression and mineral absorption capacity in broiler chickens.

Intestinal segment and vitamin D3 concentration affect gene expression levels of calcium and phosphorus transporters in broiler chickens

Jincheng Han,Lihua Wu,Xianliang Lv,Mengyuan Liu,Yan Zhang,Lei He,Junfang Hao,Li Xi,Hongxia Qu,Chuanxin Shi,Zhiqiang Li,Zhixiang Wang,Fei Tang,Yingying Qiao 한국축산학회 2023 한국축산학회지 Vol.65 No.2

Two experiments were conducted in this research. Experiment 1 investigated the spatial expression characteristics of calcium (Ca) and phosphorus (P) transporters in the duodenum, jejunum, and ileum of 21-day-old broilers provided with adequate nutrient feed. Experiment 2 evaluated the effects of dietary vitamin D3 (VD3) concentration (0, 125, 250, 500, 1,000, and 2,000 IU/kg) on growth performance, bone development, and gene expression levels of intestinal Ca and P transporters in 1–21-day-old broilers provided with the negative control diet without supplemental VD3. Results in experiment 1 showed that the mRNA levels of calcium- binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), plasma membrane calcium ATPase 1b (PMCA1b), and IIb sodium-phosphate cotransporter (NaPi-IIb) were the highest in the broiler duodenum. By contrast, the mRNA levels of inorganic phosphate transporter 1 (PiT-1) and 2 (PiT-2) were the highest in the ileum. Results in experiment 2 showed that adding 125 IU/kg VD3 increased body weight gain (BWG), feed intake (FI), bone weight, and percentage and weight of Ca and P in the tibia and femur of 1–21-day-old broilers compared with the negative control diet (p < 0.05). The rise in dietary VD3 levels from 125 to 1,000 IU/kg further increased the BWG, FI, and weights of the bone, ash, Ca, and P (p < 0.05). No difference in growth rate and leg bone quality was noted in the broilers provided with 1,000 and 2,000 IU/kg VD3 (p > 0.05). Supplementation with 125–2,000 IU/kg VD3 increased the mRNA abundances of intestinal Ca and P transporters to varying degrees. The mRNA level of CaBP-D28k increased by 536, 1,161, and 28 folds in the duodenum, jejunum, and ileum, respectively, after adding 1,000 IU/kg VD3. The mRNA levels of other Ca and P transporters (PMCA1b, NCX1, NaPi-IIb, PiT-1, and PiT-2) increased by 0.57–1.74 folds by adding 1,000–2,000 IU/kg VD3. These data suggest that intestinal Ca and P transporters are mainly expressed in the duodenum of broilers. Moreover, the addition of VD3 stimulates the two mineral transporter transcription in broiler intestines.

Gut Microbiota Dysbiosis Correlates With Long COVID-19 at One-Year After Discharge

Zhang Dongmei,Zhou Yaya,Ma Yanling,Chen Ping,Tang Jian,Yang Bohan,Li Hui,Liang Mengyuan,Xue YuE,Liu Yao,Zhang Jianchu,Wang Xiaorong 대한의학회 2023 Journal of Korean medical science Vol.38 No.15

Background: Long coronavirus disease 2019 (COVID-19) in recovered patients (RPs) is gradually recognized by more people. However, how long it will last and the underlining mechanism remains unclear. Methods: We conducted a prospective follow-up study to evaluate the long-term symptoms and clinical indices of RPs at one-year after discharge from Union Hospital, Wuhan, China between December 2020 to May 2021. We also performed the 16S rRNA sequencing of stool samples from RPs and healthy controls (HCs) and analyzed the correlation between the gut microbiota and long COVID-19. Results: In total, 187 RPs were enrolled, among them, 84 (44.9%) RPs reported long COVID-19 symptoms at one-year after discharge. The most common long-term symptoms were cardiopulmonary symptoms, including chest tightness after activity (39/187, 20.9%), palpitations on exercise (27/187, 14.4%), sputum (21/187, 11.2%), cough (15/187, 8.0%) and chest pain (13/187, 7.0%), followed by systemic symptoms including fatigue (34/187, 18.2%) and myalgia (20/187, 10.7%), and digestive symptoms including constipation (14/187, 7.5%), anorexia (13/187, 7.0%), and diarrhea (8/187, 4.3%). Sixty-six (35.9%) RPs presented either anxiety or depression (42/187 [22.8%] and 53/187 [28.8%] respectively), and the proportion of anxiety or depression in the long symptomatic group was significantly higher than that in the asymptomatic group (41/187 [50.6%] vs. 25/187 [24.3%]). Compared with the asymptomatic group, scores of all nine 36-Item Short Form General Health Survey domains were lower in the symptomatic group (all P < 0.05). One hundred thirty RPs and 32 HCs (non-severe acute respiratory syndrome coronavirus 2 infected subjects) performed fecal sample sequencing. Compared with HCs, symptomatic RPs had obvious gut microbiota dysbiosis including significantly reduced bacterial diversities and lower relative abundance of short-chain fatty acids (SCFAs)-producing salutary symbionts such as Eubacterium_hallii_group, Subdoligranulum, Ruminococcus, Dorea, Coprococcus, and Eubacterium_ventriosum_group. Meanwhile, the relative abundance of Eubacterium_hallii_group, Subdoligranulum, and Ruminococcus showed decreasing tendencies between HCs, the asymptomatic group, and the symptomatic group. Conclusion: This study demonstrated the presence of long COVID-19 which correlates with gut microbiota dysbiosis in RPs at one-year after discharge, indicating gut microbiota may play an important role in long COVID-19.