1.Role of calcium-activated potassium channels in neuronal pacemaker activity
Chinese Journal of Pharmacology and Toxicology 2016;30(6):627-639
Spontaneous rhythmic activity of pacemaker neurons in the central nervous system underlies fundamental neurological processes such as locomotion, cognition and circadian rhythm. Among the wide range of ion channels required for its generation, the Ca2+-activated K+(KCa) channels play a prominent role in maintaining physiologically-relevant frequency and pattern of pacemaker activity. Much of our understanding of the functions of KCa channels in pacemaker neurons have been derived from pharmacological studies using channel modulators, such as iberiotoxin and apamin. Despite the significant advances made, recent studies have painted an increasingly complex picture of the effects of widely used KCa channel modulators on unintended targets that may confound our under?standing of their functions. In this review, we discussed the utility and shortcomings of the KCa channel modulators, and highlighted the significance of these findings, because the KCa channel modulators have been used in early clinical trials to treat disorders ranging from Parkinson disease to alcoholism.
3.The protective role of peroxisome proliferator activated receptors-α and pathomechanism in D-galactosamine/lipopolysaccharide-induced acute liver failure in rats
Mingjing JIAO ; Feng REN ; Li ZHOU ; Zhongping DUAN ; Caiyan ZHAO
Chinese Journal of Internal Medicine 2014;53(9):730-734
Objective To determine the role and mechanism of peroxisome proliferator activated receptors (PPAR) α in a mouse model of D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced acute liver failure(ALF).Methods Firstly,C57BL/6 mice were randomly divided into control group(n =8),ALF 2h group(n =8),ALF 4h group (n =8),ALF 6h group (n =8).Secondly C57BL/6 mice were randomly divided into control group(n =8),ALF group(n =8),WY14643 group(n =8).To induce ALF,the mice were injected intraperitoneally with D-GalN (700 mg/kg) and LPS (10 μg/kg).WY14643 (6 mg/kg),the selective agonist of PPAR α,was administered via tail vein two hours prior to D-GalN/LPS exposure.Two,four,and six hours after D-GalN/LPS treatment in the first study,mice were anesthetized and blood was collected,6h after D-GalN/LPS treatment in the second study,blood was collected.The liver tissue was harvested for histology and mRNA extraction.Serum levels of ALT and AST were measured to evaluate the hepatic damage.Inflammatory cytokines (TNFα,IL-1β,IL-6) and chemokines (CXCL-1,CXCL-10) were detected by real-time quantitative PCR.Differential protein expression of p-NF-κBp65,p-JNK,p-ERK,p-p38 in inflammatory pathways was detected by Western blotting.Significance of inter-group differences was assessed by one-way ANOVA,and pairwise comparison was performed by the least significant difference test.Results The gene and protein expression of PPAR α were gradually reduced during the development of ALF.Compared with the model group,the liver architecture was better preserved almost with normal morphology in WY14643-treated mice.Serum ALT and AST levels in WY14643-treated group were significantly lower [ALT:(555 ±62)U/L vs (2 898 ±822) U/L,P <0.05; AST:(791 ±58) U/L vs (3 013 ±997)U/L,P < 0.05].The expression of proinflammatory cytokines and chemokines was significantly suppressed during the activation of PPAR α.In the second study,the levels of gene expression of proinflammatory cytokines and chemokines were detected in control group,ALF group and WY14643 group respectively as followings:TNFα (0.161 ± 0.085,7.996 ± 1.068,3.346 ± 0.94,P < 0.05),IL-1β(0.041 ±0.002,3.657 ±0.904,0.176±0.089,P<0.01),IL-6 (0.018 ±0.008,1.762 ±0.589,0.163±0.0487,P <0.05),CXCL-1 (0.063 ±0.008,7.881 ±0.966,2.737 ±0.864,P <0.01),CXCL-10 (0.054 ±0.005,5.671 ±0.948,2.578 ±0.804,P <0.05).Conclusion Our findings first demonstrate that PPARα protects liver from injury in an ALF mouse model by suppressing inflammatory response,indicating PPARα as a potential new therapeutic target for ALF.
5.Rotating magnetic fields and granisetron treatment for preventing nausea and vomiting induced by chemo-therapy
Zhibing WU ; Shenglin MA ; Xiangming KONG ; Jianguo FENG ; Zhongping LOU ; Aiqin ZHANG
Chinese Journal of Physical Medicine and Rehabilitation 2008;30(6):402-404
Objective To observe the efficacy of a rotating magnetic field and granisetron hydrochloride in preventing nausea and vomiting caused by a eisplatin regimen, and any side effects. Methods Sixty-eight patients receiving cisplatin regimen chemotherapy were randomly assigned to two groups: a magnetic treatment group and a drug treatment group. The patients in the two groups were exposed to a rotating magnetic field or received granisetron hydrochloride, respectively. The effects of the treatments were observed. Results Both treatments could effectively prevent and treat the vomiting caused by chemotherapy. The rate of response to the rotating magnetic field was 88.2% and to the drug 91.2%. However, tardive vomiting was significantly better controlled in the rotating magnetic field group. The incidence of side effects in the magnetic field group was 20.6% , and in the drug treatment group it was 45.6%. Conclusion The efficacy of a rotating magnetic field and granisetron in treating acute vomiting were simi- lar. The rotating magnetic field was more effective in preventing tardive vomiting and had fewer side effects. Magnetic therapy should be more generally applied in clinical practice.
6.The effects of a rotating magnetic field in the prevention and treatment of irradiation-induced esophagitis
Zhibing WU ; Shenglin MA ; Wei WU ; Jianguo FENG ; Zhiming JIANG ; Zhongping LOU
Chinese Journal of Physical Medicine and Rehabilitation 2012;34(2):95-98
Objective To observe the effect of a rotating magnetic field in preventing and treating irradiation-induced esophagitis in rats. Methods Forty female Wistar rats were randomized into 5 groups:a non-irradiated control group,an irradiation group,an amifostine treatment group ( amifostine group ),a 90 min magnetic field treatment group (90 min magnetic group) and a 120 min magnetic field treatment group ( 120 min magnetic group),with 8 rats in each group.The esophaguses of all rats except those in the control group were exposed to a single irradiation with 6 MV X-rays from a linear accelerator at a dosage of 43 Gy.Four rats in each group were randomly chosen to be observed 1 and 2 weeks after the irradiation.Blood cytokines were detected in their arterial blood.Any pathological changes of the esophagus were observed with HE staining under a light microscope at the same time. Results Irradiation-induced esophagitis was observed in the irradiation group 7 days after irradiation,with obvious exfoliation and necrosis of the esophagal epithelium mucosae.The submucosa were hyperaemic and dropsical with abundant inflammatory cell infiltration.The pathological changes of the esophagus were similar at 7 and 14 days after irradiation.However,the irradiation-induced esophagitis of rats in the amifostine group,the 90 min magnetic group and the 120 min magnetic group were relatively slighter and the blood leucocytes and neutrophis in those 3 groups were significantly lower than those in the irradiation group,while a tendency toward repair of the mucosa of the esophagus was detected.Serum TNF-α,IL-1 and IL-6 in the 90 min magnetic group and 120 min magnetic group were significantly lower than those in the irradiation group. Conclusions Both a rotating magnetic field and amifostine can help prevent and treat irradiation-induced esophagitis.Their therapeutic efficacy is similar.Exposure to a rotating magnetic field could inhibit the expression of inflammatory factors,and thus lessen the inflammatory reaction of acute irradiation-induced esophagitis.
7.Activated peroxisome proliferator-activated receptor αinhibiting the lipopolysaccharide-induced macrophage-mediated inflammatory responses by promoting the autophagy
Rongrong YANG ; Li ZHANG ; Xiangying ZHANG ; Hongbo SHI ; Dexi CHEN ; Zhongping DUAN ; Feng REN ; Qi WANG
Chinese Journal of Microbiology and Immunology 2015;(6):431-435
Objective To investigate the effects of peroxisome proliferator-activated receptor α( PPARα) on macrophage-mediated inflammatory responses with the interference of lipopolysaccharide and the possible mechanism.Methods The bone marrow stem cells were isolated from the femora of mice.The granulocyte-macrophage colony stimulating factor ( GM-CSF) was used to stimulate the in vitro differentiation from bone marrow stem cells into primary macrophages.An in vitro model with cultured cells expressing in-flammatory cytokines was established by treating the primary macrophages with lipopolysaccharide ( LPS) .A specific chemical agonist, Wy-14643, was used to activate PPARα. Autophagy inhibitors including 3-methyladenine (3-MA) and small interfering RNA against Atg7 ( Atg7 siRNA) were used to inhibit the autophagy.Western blot assay was performed to detect the expression of autophagy-related proteins ( Atg5, Atg7, Beclin-1 and LC3).The transcriptional levels of TNF-α, IL-1β, IL-6, Atg5, Atg7 and Beclin-1 were analyzed by qRT-PCR.Results Compared with the macrophages treated with LPS alone, those pretreated with various concentrations of Wy-14643 (10 μmol/L, 25 μmol/L and 50 μmol/L) showed inhibited ex-pression of proinflammatory cytokines ( TNF-α,IL-1βand IL-6) and enhanced expression of autophagy-relat-ed proteins (Atg5, Atg7 and Beclin-1) at mRNA level in a dose-dependent manner.The expression of auto-phagy-related proteins (Atg5, Atg7, Beclin-1 and LC3) by macrophages was promoted with the pretreatment of Wy-14643 as indicated by Western blot assay.The transcriptional levels of TNF-α, IL-1βand IL-6 were increased in Wy-14643 pretreated-macrophages after stimulation with 3-MA or Atg7 siRNA .Conclusion PPARαsuppressed the macrophage-mediated inflammatory responses by promoting autophagy, suggesting that the PPARα-autophagy pathway might be one of the signaling pathways regulating LPS induced-inflamma-tory responses.
8.Caspase-1 aggravates the D-galactosamine/lipopolysaccharide induced acute liver failure in mice through activating glycogen synthase kinase-3β
Rongrong YANG ; Feng REN ; Li ZHANG ; Xiangying ZHANG ; Hongbo SHI ; Dexi CHEN ; Zhongping DUAN ; Qi WANG
Chinese Journal of Microbiology and Immunology 2016;36(2):132-137
Objective To analyze the role of cysteinyl aspartate specific proteinase-1 (caspase-1) in a mouse model of D-galactosamine (D-GalN) and lipopolysaccharide (LPS) induced acute liver failure (ALF) and to study the possible mechanism. Methods C57BL/ 6 mice were randomly divided into four groups including control group, Z-WEHD-FMK (caspase-1 inhibitor) treatment group, ALF model group and Z-WEHD-FMK-treated ALF group. The mouse model of ALF was established by intraperitoneally injec-ting the mice with D-GalN (450 mg/ kg) and LPS (10 μg/ kg). The damages in liver tissues were evaluated based on the histopathological examination and the levels of alanine transaminase (ALT) and aspartate trans-aminase (AST) in serum samples. Western blot assay was performed to analyze the expression of caspase-1 and the phosphorylation of glycogen synthase kinase 3β (GSK-3β). The qRT-PCR was used to measure the expression of inflammatory cytokines at transcriptional level. Results The expression of caspase-1 at both mRNA and protein levels were gradually increased during the development of ALF. Compared with the mice with ALF, those in the Z-WEHD-FMK-treated ALF group showed less severe liver damages on histopatholog-ical examination and decreased levels of ALT and AST in serum samples [ALT: (479. 2±39. 5) U/ L vs (998. 5±60. 4 ) U/ L, P<0. 05; AST: ( 478. 5±28. 6) U/ L vs ( 1 180. 7±91. 4) U/ L, P<0. 05]. The expression of TNF-α, IL-1β, IL-18 and IL-33 at transcriptional level were significantly suppressed in mice with ALF upon the Z-WEHD-FMK intervention. Results of the Western blot assay indicated that Z-WEHD-FMK suppressed the activities of GSK-3β by enhancing its phosphorylation. Conclusion This study demon-strated that caspase-1 could promote the activation of GSK-3β resulting in the development of inflammation responses and liver damages during the development of ALF in mice.
9.Impact of ecological protection construction on schistosomiasis transmission of Qionghai Lake wetland in Xichang City
Zongliang FENG ; Congmin XU ; Hongzhi YIN ; Jiao HUA ; Yuhua LAI ; Lin ZHAO ; Zhongping WU
Chinese Journal of Schistosomiasis Control 2016;(1):62-65
Objective To understand the impact of Qionghai Lake wetland ecological protection construction on the preva?lence of schistosomiasis,so as to provide the evidence for formulating the strategies for schistosomiasis control and prevention. Methods A retrospective survey of the construction of Qionghai Lake wetland was performed,and eleven villages around the wetland were surveyed for schistosomiasis endemic situation. The influence of the wetland project on the schistosomiasis preva?lence and Oncomelania hupensis snail status were investigated. Results Before the construction of Qionghai Lake wetland,the snail elimination and extended chemotherapy for residents was performed. After the project was finished,the roads and ditches were hardened. From 2009 to 2014,the schistosome infection rate of residents declined from 0.37% to 0. No schistosome infect?ed snails were found and in recent 2 years,no snails were found. No mice were infected in the sentinel tests. Conclusions The construction of Qionghai Lake wetland effectively eliminates snails,and interrupts the transmission of schistosomiasis. Howev?er,the environment of the wetland is more suitable for snail breeding,and therefore,the surveillance still should be strength?ened.
10.Endoplasmic reticulum stress promote hepatocyte apoptosis by mediating glycogen synthase kinase 3β
Bingzhang YANG ; Feng REN ; Tao WEN ; Zhengfu PIAO ; Sujun ZHENG ; Jing ZHANG ; Yu CHEN ; Dexi CHEN ; Zhongping DUAN ; Shuisheng SHI
Chinese Journal of Microbiology and Immunology 2012;32(7):617-621
Objective To analyze the role of a key intracellular signaling molecule GSK3β in hepatocyte apoptosis induced by endoplasmic reticulum stress (ERS).Methods Using mouse hepatoma cell lines(Hepa 1) as cell apoptosis model triggered by tunicamycin,an endoplasmic reticulum stress inducer.One hour before Hepa 1 apoptosis induced by tunicamycin,SB216763 specifically inhibited the activity of GSK3β.Living cells/apoptotic cells were detected using acetoxymethyl (AM)/propidium iodide (PI) staining; Furthermore,the measurement of lactate dehydrogenase(LDH) of cell culture supernatant to evaluate the apoptosis.We detect p-GSK3β,GSK3β,the ERS-related protein(GRP78,CHOP and caspase-12) and caspase-3,cleaved caspase-3 protein expression using Western blot.Results Endoplasmic reticulum stress induced by tunicamycin promotes GSK3β activity; Inhibition of GSK3β activity alleviates endoplasmic reticulum stress:the expression of GRP78,CHOP and caspase-12 expression are inhibited.At the same time,GSK3β activity inhibition significantly reduced the endoplasmic reticulum stress-induced apoptosis:compared to cell apoptosis model group,the intervention group of SB216763 showed that the level of LDH decreased significantly,and PI staining of apoptotic cells was also significant reduction.Western blot results showed that the inhibition of GSK 3 β activity reduced reactive cleaved caspase-3 protein.Conclusion GSK3β is an important signaling molecule in the apoptosis pathway induced by endoplasmic reticulum stress ;Endoplasmic reticulum stress promotes hepatocyte apoptosis by mediating GSK3β.