Vanillylacetone attenuates cadmium chloride-induced hippocampal damage and memory loss through upregulation of nuclear factor erythroid 2-related factor 2 gene and protein expression

Memory loss and dementia are major public health concerns with a substantial economic burden.Oxidative stress has been shown to play a crucial role in the pathophysiology of hippocampal damage-induced memory impairment.To investigate whether the antioxidant and anti-inflammatory compound vanillyla cetone(zingerone) can protect against hippocampal damage and memory loss induced by cadmium chloride(CdCl_(2)) administration in rats,we explo red the potential involvement of the nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathway,which is known to modulate oxidative stress and inflammation.Sixty healt hy male Wistar rats were divided into five groups:vehicle-treated(control),vanillylacetone,CdCl_(2),vanillylacetone+ CdCl_(2),vanillylacetone+ CdCl_(2)+ brusatol(a selective pharmacological N rf2inhibitor) groups.Vanillylacetone effectively attenuated CdCl_(2)-induced damage in the dental gyrus of the hippocampus and improved the memory function assessed by the Morris Water Maze test.Additionally,vanillylacetone markedly decreased the hippocampal tissue levels of inflammatory biomarkers(interleukin-6,tumor necrosis factor-α,intracellular cell adhesive molecules) and apoptosis biomarkers(Bax and cleaved caspase-3).The control and CdCl_(2)-treated groups treated with va nillylacetone showed reduced generation of reactive oxygen species,decreased malondialdehyde levels,and increased superoxide dismutase and glutathione activities,along with significant elevation of nuclear Nrf2 mRNA and protein expression in hippocampal tissue.All the protective effects of vanillylacetone we re substantially blocked by the co-administration of brusatol(a selective N rf2 inhibitor).Va nillylacetone mitigated hippocampal damage and memory loss induced by CdCl_(2),at least in part, by activating the nuclear transcription factor Nrf2.Additionally,vanillylacetone exerted its potent antioxidant and antiinflammatory actions.

Molecular hallmarks of long non-coding RNAs in aging and its significant effect on aging-associated diseases

Aging is linked to the deterioration of many physical and cognitive abilities and is the leading risk factor for Alzheimer’s disease. The growing aging population is a significant healthcare problem globally that researchers must investigate to better understand the underlying aging processes. Advances in microarrays and sequencing techniques have resulted in deeper analyses of diverse essential genomes(e.g., mouse, human, and rat) and their corresponding cell types, their organ-specific transcriptomes, and the tissue involved in aging. Traditional gene controllers such as DNA-and RNA-binding proteins significantly influence such programs, causing the need to sort out long non-coding RNAs, a new class of powerful gene regulatory elements. However, their functional significance in the aging process and senescence has yet to be investigated and identified. Several recent researchers have associated the initiation and development of senescence and aging in mammals with several well-reported and novel long non-coding RNAs. In this review article, we identified and analyzed the evolving functions of long non-coding RNAs in cellular processes, including cellular senescence, aging, and age-related pathogenesis, which are the major hallmarks of long non-coding RNAs in aging.

Morphological and serum hyaluronic acid, laminin and type Ⅳ collagen changes in dimethylnitrosamine-induced hepatic fibrosis of rats

瞄准：学习词法并且浆液透明质酸(哈) ， laminin (行) ，和类型 IV 骨胶原在 dimethylnitrosamine (DMN ) 导致的老鼠的肝的纤维变性变化。方法：肝纤维变性的老鼠模特儿被 DMN 劝诱。浆液哈，类型 IV 骨胶原，和行被 ELISA 测量。肝 / 重量索引和词法变化在 d 上在电子显微镜下面被检验 7， 14， 21，和 28 由免疫组织化学的高山哈象天狼星红一样染色的平滑肌肌动朊 alpha-SMA 并且他染色。结果：浆液的层次哈，类型 IV 骨胶原和行显著地从 d 增加了 7 到 d 28 (P = 0.043 ) 。肝 / 重量索引在 d 上增加了 7 并且在 d 上减少了 28。在模型组，老鼠肝染色了与他和天狼星红在中央静脉显示出明显的出血和坏死肝 d 上的 10 腹片 7。薄纤维变性氏族一被形成在 d 上加入肝的中央区域 14。alpha-SMA 的数字积极房间显著地在模型组被增加。过渡肝的星形细胞在电子显微镜下面被观察。在模型组的所有老鼠在肝的实质和 alpha-SMA 的一个网络显示出微榴状的纤维变性积极房间。典型 myofibroblasts 在含纤维的中隔的核心被嵌入。比作控制组，骨胶原纤维变性的区域密度百分比并且病理学的分级在不同 d (7， 14，和 28 ) 上在模型组(P【0.05 ) 是显著地不同的。在肝的织物的骨胶原纤维变性的区域密度百分比与浆液的层次有积极关联哈，行，和类型 IV 骨胶原。结论：词法并且浆液哈，类型 IV 骨胶原，和行在老鼠在导致 DMN 的肝纤维变性被改变。

Concepts of oxidative stress and antioxidant defense in Crohn's disease

Oxygen free radical and lipid peroxides(oxidative stress)are highly reactive and represent very damaging compounds.Oxidative stress could be a major contributing factor to the tissue injury and fibrosis that characterize Crohn’s disease.An imbalance between increased reactive oxygen species levels and decreased antioxidant defenses occurs in Crohn’s patients.Decreased blood levels of vitamins C and E and decreased intestinal mucosal levels of CuZn superoxide dismutase,glutathione,vitamin A,C,E,andβ-carotene have been reported for Crohn’s patients.Increased levels of proinflammatory cytokines,such as interleukin-1 and-8 and tumor necrosis factor,have been detected in inflammatory bowel disease.Oxidative stress significantly increased the production of neutrophils,chemokines,and interleukin-8.These effects were inhibited by antioxidant vitamins and arachidonic acid metabolite inhibitors in human intestinal smooth muscle cells isolated from the bowels of Crohn’s disease patients.The main pathological feature of Crohn’s disease is an infiltration of polymorphonuclear neutrophils and mononuclear cells into the affected part of the intestine.Activated neutrophils produce noxious substances that cause inflammation and tissue injury.Due to the physiological and biochemical actions of reactive oxygen species and lipid peroxides,many of the clinical and pathophysiological features of Crohn’s disease might be explained by an imbalance of increased reactive oxygen species and a net decrease of antioxidant molecules.This review describes the general concepts of free radical,lipid peroxide and antioxidant activities and eventually illustrates their interferences in the development of Crohn’s strictures.

Inhibition of pacemaker activity in interstitial cells of Cajal by LPS via NF-κB and MAP kinase

AIM:To investigate lipopolysaccharide(LPS) related signal transduction in interstitial cells of Cajal(ICCs) from mouse small intestine.METHODS:For this study,primary culture of ICCs was prepared from the small intestine of the mouse.LPS was treated to the cells prior to measurement of the membrane currents by using whole-cell patch clamp technique.Immunocytochemistry was used to examine the expression of the proteins in ICCs.RESULTS:LPS suppressed the pacemaker currents of ICCs and this could be blocked by AH6809,a prostaglandin E2-EP2 receptor antagonist or NG-Nitro-Larginine Methyl Ester,an inhibitor of nitric oxide(NO) synthase.Toll-like receptor 4,inducible NO synthase or cyclooxygenase-2 immunoreactivity by specific antibodies was detected on ICCs.Catalase(antioxidant agent) had no action on LPS-induced action in ICCs.LPS actions were blocked by nuclear factor kB(NF-kB) inhibitor,actinomycin D(a gene transcription inhibitor),PD 98059(a p42/44 mitogen-activated protein kinases inhibitor) or SB 203580 [a p38 mitogen-activated protein kinases(MAPK) inhibitor].SB 203580 also blocked the prostaglandin E2-induced action on pacemaker currents in ICCs but not NO.CONCLUSION:LPS inhibit the pacemaker currents in ICCs via prostaglandin E2-and NO-dependent mechanism through toll-like receptor 4 and suggest that MAPK and NF-kB are implicated in these actions.

Gene expression profiling and endothelin in acute experimental pancreatitis

AIM:To analyze gene expression profiles in an experimental pancreatitis and provide functional reversal of hypersensitivity with candidate gene endothelin-1 antagonists.METHODS:Dibutyltin dichloride(DBTC) is a chemical used as a polyvinyl carbonate stabilizer/catalyzer,biocide in agriculture,antifouling agent in paint and fabric.DBTC induces an acute pancreatitis flare through generation of reactive oxygen species.Lewis-inbred rats received a single i.v.injection with either DBTC or vehicle.Spinal cord and dorsal root ganglia(DRG) were taken at the peak of inflammation and processed for transcriptional profiling with a cDNA microarray biased for rat brain-specific genes.In a second study,groups of animals with DBTC-induced pancreatitis were treated with endothelin(ET) receptor antagonists [ET-A(BQ123) and ET-B BQ788)].Spontaneous pain related mechanical and thermal hypersensitivity were measured.Immunohistochemical analysis was performed using anti-ET-A and ET-B antibodies on sections from pancreatic tissues and DRG of the T10-12 spinal segments.RESULTS:Animals developed acute pancreatic inflammation persisting 7-10 d as confirmed by pathological studies(edema in parenchyma,loss of pancreatic architecture and islets,infiltration of inflammatory cells,neutrophil and mononuclear cells,degeneration,vacuolization and necrosis of acinar cells) and the painrelated behaviors(cutaneous secondary mechanical and thermal hypersensitivity).Gene expression profile was different in the spinal cord from animals with pancreatitis compared to the vehicle control group.Over 260 up-regulated and 60 down-regulated unique genes could be classified into 8 functional gene families:circulatory/acute phase/immunomodulatory;extracellular matrix;structural;channel/receptor/transporter;signaling transduction;transcription/translation-related;antioxidants/chaperones/heat shock;pancreatic and other enzymes.ET-1 was among the 52 candidate genes upregulated greater than 2-fold in animals with pancreatic inflammation and visceral pain-related behavior.Treatments with the ET-A(BQ123) and ET-B(BQ-788) antagonists revealed significant protection against inflammatory pain related mechanical and thermal hypersensitivity behaviors in animals with pancreatitis(P < 0.05).Open field spontaneous behavioral activity(at baseline,day 6 and 30 min after drug treatments(BQ123,BQ788) showed overall stable activity levels indicating that the drugs produced no undesirable effects on normal exploratory behaviors,except for a trend toward reduction of the active time and increase in resting time at the highest dose(300 μmol/L).Immunocytochemical localization revealed that expression of ET-A and ET-B receptors increased in DRG from animals with pancreatitis.Endothelin receptor localization was combined in dual staining with neuronal marker NeuN,and glia marker,glial fibrillary acidic protein.ET-A was expressed in the cell bodies and occasional nuclei of DRG neurons in na ve animals.However,phenotypic expression of ET-A receptor was greatly increased in neurons of all sizes in animals with pancreatitis.Similarly,ET-B receptor was localized in neurons and in the satellite glia,as well as in the Schwann cell glial myelin sheaths surrounding the axons passing through the DRG.CONCLUSION:Endothelin-receptor antagonists protect against inflammatory pain responses without interfering with normal exploratory behaviors.Candidate genes can serve as future biomarkers for diagnosis and/or targeted gene therapy.

Preventive effect of Qianggan-Rongxian Decoction on rat liver fibrosis

AIM: To study the preventive effects of Qianggan-Rongxian Decoction on liver fibrosis induced by dimethylnitrosamine (DMN) in rats. METHODS: Male Wistar rats were randomly divided into hepatic fibrosis model group, control group and 3 treatment groups (12 rats in each group). Except for the normal control group, all the rats received 1% DMN (10 μL/kg body weight, i.p), 3 times a week for 4 wk. The rats in the 3 treatment groups including a high-dose DMN group (10 mL/kg), a medium-dose DMN group (7 mL/kg), and a low-dose DMN group (4 mL/kg) were daily gavaged with Qianggan-Rongxian Decoction, and the rats in the model and normal control groups were given saline vehicle. Enzyme-linked immunosorbent assay (ELISA) was used to determine the changes in serum hyaluronic acid (HA), laminin (LN), and type IV collagen levels. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured using routine laboratory methods. Pathologic changes, particularly fibrosis, were examined by hematoxylin and eosin (HE) and Sirius red staining. Hepatic stellate cells (HSC) were examined by transmission electron microscopy. RESULTS: Compared with the model control group, the serum levels of HA, LN, type Ⅳ collagen, ALT and AST were decreased markedly in the other groups after treatment with Qianggan-Rongxian Decoction, especially in the medium-dose DMN group (P < 0.05).Moreover, the area-density percentage of collagen fibrosis was lower in the Qianggan-Rongxian Decoction treatment groups than in the model group, and a more significant drop was observed in the medium-dose DMN group (P < 0.05). CONCLUSION: Qianggan-Rongxian Decoction can inhibit hepatic fibrosis due to chronic liver injury, delay the development of cirrhosis, and notably ameliorate liver function. It may be used as a safe and effective thera-peutic drug for patients with fibrosis.

Identification of TRPM7 channels in human intestinal interstitial cells of Cajal

AIM:To investigate the characteristics of slow elec-trical waves and the presence of transient receptor potential melastatin-type 7(TRPM7)in the human gas-trointestinal(GI)tract.METHODS:Conventional microelectrode techniques were used to record intracellular electrical responses from human GI smooth muscle tissue.Immunohisto-chemistry was used to identify TRPM7 channels in in-terstitial cells of Cajal(ICCs).RESULTS:The human GI tract generated slow electri-cal waves and had ICCs which functioned as pacemak-er cells.Flufenamic acid,a nonselective cation channel blocker,and 2-APB(2-aminoethoxydiphenyl borate)and La3+,TRPM7 channel blockers,inhibited the slowwaves.Also,TRPM7 channels were expressed in ICCs in human tissue.CONCLUSION:These results suggest that the human GI tract generates slow waves and that TRPM7 chan-nels expressed in the ICCs may be involved in the gen-eration of the slow waves.

Lead exposure increases oxidative stress in the gastric mucosa of HCl/ethanol-exposed rats

AIM: To investigate the role of reactive oxygen species in the ulcer-aggravating effect of lead in albino rats. METHODS: Albino Wistar rats were randomly divided into three groups and treated orally with 100 mg/L (low dose) or 5000 mg/L (high dose) of lead acetate for 15 wk. A third group received saline and served as control. At the end of wk 15, colorimetric assays were applied to determine the concentrations of total protein and nitrite, the activities of the oxidative enzymes catalase and superoxide dismutase, and lipid peroxidation in homogenized gastric mucosal samples. RESULTS: Exposure of rats to lead significantly increased the gastric mucosal damage caused by acidified ethanol. Although the basal gastric acid secretory rate was not significantly altered, the maximal response of the stomach to histamine was significantly higher in the lead-exposed animals than in the unexposed control group. Exposure to low and high levels of lead significantly increased gastric lipid peroxidation to 183.2% ± 12.7% and 226.1% ± 6.8% of control values respectively (P < 0.0). On the other hand, lead exposure significantly decreased catalase and superoxide dismutase (SOD) activities and the amount of nitrite in gastric mucosal samples. CONCLUSION: Lead increases the formation of gastric ulcers by interfering with the oxidative metabolism in the stomach.

Effect of methanol extract of Ricinus communis seed on reproduction of male rats

Aim： To investigate the effect of methanol extract of Ricinus communis seed （RCE） on male rats reproductive functions. Methods： Thirty-two male albino rats were divided into four groups. Groups 1, 2 and 3 were gavaged with 0.2 mL of 2.5% tween 80 （RCE vehicle; control） or 20 mg/（kg-d） and 40 mg/（kg-d） of RCE, respectively, for 30 days, and group 4 was also gavaged with 40 mg/（kg.d） of RCE, but was allowed a recovery periold of 30 days. Five untreated female rats were cohabited with male rats in each group from day 25 of RCE treatment for 5 days, except group 4, where cohabitation began on day 25 of the recovery period. All male rats were sacrificed 24 h after the experiments. The female rats were laparatomized on day 19 of pregnancy and the number and weight of litters were recorded. Results： There was a significant decrease （P 〈 0.01） in the weight of the reproductive organs, sperm functions and serum levels of testosterone in RCE treated rats. There was disorganization in the cytoarchitecture of the testes, disruption of the seminiferous tubules and erosion of the germinal epithelium. The number and weight of litters of rats in groups 2 and 4 decreased significantly （P 〈 0.05） but no changes were observed in group 3. RCE caused no changes in liver, kidney, heart or body weights in male rats. Conclusion： RCE has a reversible negative impact on male reproductive functions, which appears to be mediated via gonadal disruption in testosterone secretion. （Asian J Androl 2006 Jan; 8： 115-121）

Neuroprotective effects of bovine colostrum on intracerebral hemorrhage-induced apoptotic neuronal cell death in rats

Brain cell death after intracerebral hemorrhage may be mediated in part by an apoptotic mechanism Colostrum is the first milk produced by mammals for their young. It plays an important role in protection and development by providing various antibodies, growth factors and nutrients, and has been used for various diseases in many countries. In the present study, we investigated the anti-apoptotic effects of bovine colostrum using organotypic hippocampal slice cultures and an intracerebral hemorrhage animal model. We performed densitometric measurements of propidium iodide uptake, a step-down avoidance task, Nissl staining, and caspase-3 immunohistochemistry. The present results revealed that colostrum treatment significantly suppressed N-methyI-D-aspartic acid-induced neuronal cell death in the rat hippocampus. Moreover, colostrum treatment improved short-term memory by suppressing hemorrhage-induced apoptotic neuronal cell death and decreasing the volume of the lesion induced by intracerebral hemorrhage in the rat hippocampus. These results suggest that colostrum may have a beneficial role in recovering brain function following hemorrhagic stroke by suppressing apoptotic cell death.

Localization of ANP-synthesizing cells in rat stomach

AIM: To study the morphological positive expression of antrial natriuretic peptide (ANP)-synthesizing cells and ultrastructural localization and the relationship between ANP-synthesizing cells and microvessel density in the stomach of rats and to analyze the distribution of the three histologically distinct regions of ANP-synthesizing cells. METHODS: Using immunohistochemical techniques, we studied positive expression of ANP-synthesizing cells in rat stomach. A postembedding immunogold microscopy technique was used for ultrastructural localization of ANP-synthesizing cells. Microvessel density in the rat stomach was estimated using tannic acid-ferric chloride (TAFC) method staining. Distribution of ANP-synthesizing cells were studied in different regions of rat stomach histochemically. RESULTS: Positive expression of ANP-synthesizing cells were localized in the gastric mucosa of rats. Localization of ANP-synthesizing cells identified them to be enterochrochromaffin cells (EC) by using a postembedding immunogold electron microscopy technique. EC cells were in the basal third of the cardiac mucosa region. ANP-synthesizing cells existed in different regions of rat stomach and its density was largest in the gastric cardiac region, and the distribution order of ANP-synthesizing cells in density was cardiac region, pyloric region and fundic region in mucosa layer. We have also found a close relationship between ANP-synthesizing cells and microvessel density in gastric mucosa of rats using TAFC staining. CONCLUSION: ANP-synthesizing cells are expressedin the gastric mucosa. EC synthesize ANP. There is a close relationship between ANP-synthesizing cells and microvessel density in gastric mucosa of rats.The distribution density of ANP-synthesizing cells is largest in the gastric cardiac region.

Neuroprotective effects of tadalafil on gerbil dopaminergic neurons following cerebral ischemia

Impairment of dopamine function, which is known to have major effects on behaviors and cognition, is one of the main problems associated with cerebral ischemia. Tadalafil, a long-acting phosphodiesterase type-5 inhibitor, is known to ameliorate neurologic impairment induced by brain injury, but not in dopaminergic regions. We investigated the neuroprotective effects of treatment with tadalafil on cyclic guanosine monophosphate level and dopamine function following cerebral ischemia. Forty adult Mongolian gerbils were randomly and evenly divided into five groups （n = 8 in each group）： Sham-operation group, cerebral ischemia-induced and 0, 0.1, 1, and 10 mg/kg tadalafil-treated groups, respectively. Tadalafil dissolved in distilled water was administered orally for 7 consecutive days, starting 1 day after surgery. Cyclic guanosine monophosphate assay and immunohistochemistry were performed for thyrosine hydroxylase expression and western blot analysis for dopamine D2 receptor expression. A decrease in cyclic guanosine monophosphate level following cerebral ischemia was found with an increase in thyrosine hydroxylase activity and a decrease in dopamine D2 receptor expression in the striatum and substantia nigra region. However, treatment with tadalafil increased cyclic guanosine monophosphate expression, suppressed thyrosine hydroxylase expression and increased dopamine 92 receptor expression in the striatum and substantia nigra region in a dose-dependent manner. Tadalafil might ameliorate cerebral ischemia-induced dopaminergic neuron injury. Therefore, tadalafil has the potential as a new neuroprotective treatment strategy for cerebral ischemic injury.

Effect of hyperthermia on calbindin-D 28k immunoreactivity in the hippocampal formation following transient global cerebral ischemia in gerbils

Calbindin D-28K （CB）, a Ca2＋-binding protein, maintains Ca2＋ homeostasis and protects neurons against various insults. Hyperthermia can exacerbate brain damage produced by ischemic insults. However, little is reported about the role of CB in the brain under hyperthermic condition during ischemic insults. We inves- tigated the effects of transient global cerebral ischemia on CB immunoreactivity as well as neuronal damage in the hippocampal formation under hyperthermic condition using immunohistochemistry for neuronal nuclei （NeuN） and CB, and Fluoro-Jade B histofluorescence staining in gerbils. Hyperthermia （39.5 ＋ 0.2~C） was induced for 30 minutes before and during transient ischemia. Hyperthermic ischemia resulted in neu- ronal damage/death in the pyramidal layer of CA1-3 area and in the polymorphic layer of the dentate gyrus at 1, 2, 5 days after ischemia. In addition, hyperthermic ischemia significantly decreaced CB immunoreac- tivity in damaged or dying neurons at 1, 2, 5 days after ischemia. In brief, hyperthermic condition produced more extensive and severer neuronal damage/death, and reduced CB immunoreactivity in the hippocampus following transient global cerebral ischemia. Present findings indicate that the degree of reduced CB immu- noreactivity might be related with various neuronal damage/death overtime and corresponding areas after ischemic insults.

Antispermatogenic activity of Morinda lucida extract in male rats

Aim： To investigate the effect of Morinda lucida Benth （Rubiaceae） on the reproductive activity of male albino rats. Methods： Two groups of rats were treated with 400 mg/（kg.d） of Morinda lucida leaf extract for 4 and 13 weeks, respectively. The control rats received the vehicle. All the treated rats had corresponding recovery groups. At the end of each experimental period, animals were killed and organ weights, sperm characteristics, serum testosterone levels, histology of the testes and fertility were assessed. Results： Morinda lucida leaf extract did not cause any changes in body and somatic organ weights, but significantly increased the testis weight （P 〈 0.05）. The sperm motility and viability, and the epididymal sperm counts of rats treated for 13 weeks were significantly reduced （P 〈 0.05）. Sperm morphological abnormalities and serum testosterone levels were significantly increased （P 〈 0.05）. There were various degrees of damage to the seminiferous tubules. The extract reduced the fertility of the treated rats by reducing the litter size. Reversal of these changes, however, occurred after a period of time. Conclusion： The extract of Morinda lucida has reversible antispermatogenic properties.

Effects of prostaglandin F_(2α) on small intestinal interstitial cells of Cajal

AIM:To explore the role of prostaglandin F2α(PGF2α) on pacemaker activity in interstitial cells of Cajal(ICC)from mouse small intestine. METHODS:In this study,effects of PGF2αin the cultured ICC cells were investigated with patch clamp technology combined with Ca 2+ image analysis. RESULTS:Externally applied PGF2α(10μmol/L)produced membrane depolarization in current-clamp mode and increased tonic inward pacemaker currents in voltage-clamp mode.The application of flufenamic acid(a non-selective cation channel inhibitor)or niflumic acid(aCl channel inhibitor)abolished the generation of pacemaker currents but only flufenamic acid inhibited the PGF2α-induced tonic inward currents.In addition,the tonic inward currents induced by PGF2αwere not inhibited by intracellular application of 5’-[-thio]diphosphate trilithium salt.Pretreatment with Ca 2+ free solution, U-73122,an active phospholipase C inhibitor,and thapsigargin,a Ca 2+ -ATPase inhibitor in endoplasmic reticulum,abolished the generation of pacemaker currents and suppressed the PGF2α-induced tonic inward currents.However,chelerythrine or calphostin C,protein kinase C inhibitors,did not block the PGF2α-induced effects on pacemaker currents.When recording intracellular Ca 2+ ([Ca 2+ ]i)concentration using fluo-3/AM,PGF2α broadly increased the spontaneous[Ca 2+ ]i oscillations. CONCLUSION:These results suggest that PGF2αcan modulate pacemaker activity of ICC by acting non-selective action channels through phospholipase C-dependent pathway via[Ca2+]i

Switching-on of serotonergic calcium signaling in activated hepatic stellate cells

AIM:To investigate serotonergic Ca 2+ signaling and the expression of 5-hydroxytryptamine(5-HT) receptors,as well as Ca 2+ transporting proteins,in hepatic stellate cells(HSCs) . METHODS:The intracellular Ca 2+ concentration([Ca 2+ ]i) of isolated rat HSCs was measured with a fluorescence microscopic imaging system.Quantitative PCR was per-formed to determine the transcriptional levels of 5-HT receptors and endoplasmic reticulum(ER) proteins involved in Ca 2+ storage and release in cultured rat HSCs. RESULTS:Distinct from quiescent cells,activated HSCs exhibited[Ca 2+ ]i transients following treatment with 5-HT,which was abolished by U-73122,a phospholipase C inhibitor.Upregulation of 5-HT2A and 5-HT2B receptors,but not 5-HT3,was prominent during trans-differentiation of HSCs.Pretreatment with ritanserin,a 5-HT2 antagonist,inhibited[Ca 2+ ]i changes upon application of 5-HT.Expression of type 1 inositol-5'-triphosphate receptor and type 2 sarcoplasmic/endoplasmic reticulum Ca 2+ ATPase were also increased during activation of HSCs and serve as the major isotypes for ER Ca 2+ storage and release in activated HSCs.Ca 2+ binding chaperone proteins of the ER,including calreticulin,calnexin and calsequestrin,were up-regulated following activation of HSCs. CONCLUSION:The appearance of 5-HT-induced[Ca 2+ ]i response accompanied by upregulation of metabotropic 5-HT2 receptors and Ca 2+ transporting/chaperone ER proteins may participate in the activating process of HSCs.

Relaxation of rabbit cavernous smooth muscle to 17β-estradiol: a non-genomic, NO-independent mechanism

Aim: To investigate whether estrogen was involved in relaxation of rabbit cavernous smooth muscle. Methods: Relaxation response of the rabbit cavernous smooth muscles to 17β-estradiol (0.3, 3, 30 and 300 nmol/L) were observed in vitro. The response of the muscle strips to estrogen after incubation with either actinomycin D (10μmol/L) or L-NAME (10μmol/L) were also evaluated. Inside-out mode of patch clamp in a single smooth muscle cell was applied to investigate the Maxi-K channel activities. Results: Estrogen caused a dose-dependent relaxation of the strips precontracted with norepinephrine. The maximal response was noted about 10 minutes after treatment. The estrogen-induced relaxation was prevented by neither actinomycin D nor L-NAME, suggesting that the response was not mediated by gene transcription or nitric oxide (NO). Application of 17β-estradiol increased the Maxi-K channel activities. Conclusion: 17β-estradiol may be involved in relaxation of rabbit cavernous smooth muscles via a non genomic and NO independent mechanism. 17β-estradiol stimulates Maxi-K channel of the rabbit cavernous myocyte.

Effects of apoptosis on liver aging

As an irreversible and perennial process,aging is accompanied by functional and morphological declines in organs. Generally,aging liver exhibits a decline in volume and hepatic blood flow. Even with a preeminent regenerative capacity to restore its functions after liver cell loss,its biosynthesis and metabolism abilities decline,and these are difficult to restore to previous standards. Apoptosis is a programmed death process via intrinsic and extrinsic pathways,in which Bcl-2 family proteins and apoptosis-related genes,such as p21 and p53,are involved.Apoptosis inflicts both favorable and adverse influences on liver aging.Apoptosis eliminates transformed abnormal cells but promotes age-related liver diseases,such as nonalcoholic fatty liver disease,liver fibrosis,cirrhosis,and liver cancer. We summarize the roles of apoptosis in liver aging and age-related liver diseases.

Attenuating effect of daidzein on polychlorinated biphenyls-induced oxidative toxicity in mouse testicular cells

The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with DAI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary DAI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.