Bidirectional regulation of the cyclic guanosine monophosphateadenosine monophosphate synthase-stimulator of interferon gene pathway and its impact on hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)ranks as the fourth leading cause of cancerrelated deaths in China,and the treatment options are limited.The cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)activates the stimulator of interferon gene(STING)signaling pathway as a crucial immune response pathway in the cytoplasm,which detects cytoplasmic DNA to regulate innate and adaptive immune responses.As a potential therapeutic target,cGASSTING pathway markedly inhibits tumor cell proliferation and metastasis,with its activation being particularly relevant in HCC.However,prolonged pathway activation may lead to an immunosuppressive tumor microenvironment,which fostering the invasion or metastasis of liver tumor cells.AIM To investigate the dual-regulation mechanism of cGAS-STING in HCC.METHODS This review was conducted according to the PRISMA guidelines.The study conducted a comprehensive search for articles related to HCC on PubMed and Web of Science databases.Through rigorous screening and meticulous analysis of the retrieved literature,the research aimed to summarize and elucidate the impact of the cGAS-STING pathway on HCC tumors.RESULTS All authors collaboratively selected studies for inclusion,extracted data,and the initial search of online databases yielded 1445 studies.After removing duplicates,remaining 964 records were screened.Ultimately,55 articles met the inclusion criteria and were included in this review.CONCLUSION Acute inflammation can have a few inhibitory effects on cancer,while chronic inflammation generally promotes its progression.Extended cGAS-STING pathway activation will result in a suppressive tumor microenvironment.

Exploring the interaction between the gut microbiota and cyclic adenosine monophosphate-protein kinase A signaling pathway:a potential therapeutic approach for neurodegenerative diseases

The interaction between the gut microbiota and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)signaling pathway in the host's central nervous system plays a crucial role in neurological diseases and enhances communication along the gut–brain axis.The gut microbiota influences the cAMP-PKA signaling pathway through its metabolites,which activates the vagus nerve and modulates the immune and neuroendocrine systems.Conversely,alterations in the cAMP-PKA signaling pathway can affect the composition of the gut microbiota,creating a dynamic network of microbial-host interactions.This reciprocal regulation affects neurodevelopment,neurotransmitter control,and behavioral traits,thus playing a role in the modulation of neurological diseases.The coordinated activity of the gut microbiota and the cAMP-PKA signaling pathway regulates processes such as amyloid-β protein aggregation,mitochondrial dysfunction,abnormal energy metabolism,microglial activation,oxidative stress,and neurotransmitter release,which collectively influence the onset and progression of neurological diseases.This study explores the complex interplay between the gut microbiota and cAMP-PKA signaling pathway,along with its implications for potential therapeutic interventions in neurological diseases.Recent pharmacological research has shown that restoring the balance between gut flora and cAMP-PKA signaling pathway may improve outcomes in neurodegenerative diseases and emotional disorders.This can be achieved through various methods such as dietary modifications,probiotic supplements,Chinese herbal extracts,combinations of Chinese herbs,and innovative dosage forms.These findings suggest that regulating the gut microbiota and cAMP-PKA signaling pathway may provide valuable evidence for developing novel therapeutic approaches for neurodegenerative diseases.

Role of cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes pathway in diabetes and its complications

Diabetes mellitus(DM)is one of the major causes of mortality worldwide,with inflammation being an important factor in its onset and development.This review summarizes the specific mechanisms of the cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)-stimulator of interferon genes(STING)pathway in mediating inflammatory responses.Furthermore,it compre-hensively presents related research progress and the subsequent involvement of this pathway in the pathogenesis of early-stage DM,diabetic gastroenteropathy,diabetic cardiomyopathy,non-alcoholic fatty liver disease,and other complic-ations.Additionally,the role of cGAS-STING in autonomic dysfunction and intes-tinal dysregulation,which can lead to digestive complications,has been discuss-ed.Altogether,this study provides a comprehensive analysis of the research advances regarding the cGAS-STING pathway-targeted therapeutic agents and the prospects for their application in the precision treatment of DM.

Effects of plant extract neferine on cyclic adenosine monophosphate and cyclic guanosine monophosphate levels in rabbit corpus cavernosum in vitro

Aim： To further investigate the relaxation mechanism of neferine （NED, a bis-benzylisoquinoline alkaloid extracted （isolated） from the green seed embryo of Nelumbo nucifera Gaertn in China, on rabbit corpus cavernosum tissue in vitro. Methods： The effects of Nef on the concentrations of cyclic adenosine monophosphate （cAMP） and cyclic guanosine monophosphate （cGMP） in isolated and incubated rabbit corpus cavernosum tissue were recorded using ^125I radioimmunoassay. Results： The basal concentration of cAMP in corpus cavernosum tissue was 5.67 ± 0.97 pmol/mg. Nef increased the cAMP concentration in a dose-dependent manner （P 〈 0.05）, but this effect was not inhibited by an adenylate cyclase inhibitor （cis-N-[2-phenylcyclopentyl]azacyclotridec-1-en-2-amine, MDL-12, 330A） （P 〉 0.05）. The accumulation of cAMP induced by prostaglandin Et （PGEt, a stimulator of cAMP production） was also augmented by Nef in a dose-dependent manner （P 〈 0.05）. The basal concentration of cGMP in corpus cavernosum tissue is 0.44 ± 0.09 pmol/mg. Nef did not affect this concentration of cGMP, either in the presence or in the absence of a guanyl cyclase inhibitor （1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, ODQ） （P 〉 0.05）. Also, sodium nitroprusside （SNP, a stimulator of cGMP production）-induced cGMP production was not enhanced by Nef （P 〉 0.05）. Conclusion： Nef, with its relaxation mechanism, can enhance the concentration of cAMP in rabbit corpus cavernosum tissue, probably by inhibiting phosphodiesterase activity. （Asian JAndro12008 Mar; 10： 307-312）

Low-power laser irradiation promotes the proliferation and osteogenic differentiation of human periodontal ligament cells via cyclic adenosine monophosphate

Retaining or improving periodontal ligament （PDL） function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation （LPLI） on the proliferation and osteogenic differentiation of human PDL （hPDL） cells. Cultured hPDL cel Is were irradiated （660 nm） daily with doses of O, 1, 2 or 4 J .cm-2. Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide （MTT） assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase （ALP） activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction （RT-PCR）. Our data showed that LPLI at a dose of 2 J.cm-2 significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J.cm-2 showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate （cAMP） is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration.

Icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels in the hippocampus of the senescence-accelerated mouse

At 8 weeks after intragastric administration of icariin to senescence-accelerated mice （P8 strain）, Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increased. Immunohistochemical staining and western blot assay detected significantly increased levels of cyclic adenosine monophosphate response element binding protein These results suggest that icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels and improves learning and memory functions in hippocampus of the senescence-accelerated mouse.

Analysis of the nitric oxide-cyclic guanosine monophosphate pathway in experimental liver cirrhosis suggests phosphodiesterase-5 as potential target to treat portal hypertension

AIM To investigate the potential effect of inhibitors of phosphodiesterase-5(PDE-5) for therapy of portal hypertension in liver cirrhosis.METHODS In the rat model of thioacetamide-induced liver fibrosis/cirrhosis the nitric oxide-cyclic guanosine monophosphate(NO-cGMP) pathway was investigated. Expression and localization of PDE-5, the enzyme that converts vasodilating cGMP into inactive 5'-GMP, was in the focus of the study. Hepatic gene expression of key components of the NO-cGMP pathway was determined by qRT-PCR: Endothelial NO synthase(eNOS), inducible NO synthase(iNOS), soluble guanylate cyclase subunits α1 and β1(sGCa1, sGCb1), and PDE-5. Hepatic PDE-5 protein expression and localization were detected by immunohistochemistry. Serum cGMP concentrations were measured using ELISA. Acute effects of the PDE-5 inhibitor Sildenafil(0.1 mg/kg or 1.0 mg/kg) on portal and systemic hemodynamics were investigated using pressure transducers.RESULTS Hepatic gene expression of eNOS(2.2-fold; P = 0.003), sGCa1(1.7-fold; P = 0.003), sGCb1(3.0-fold; P = 0.003), and PDE-5(11-fold; P = 0.003) was increased in cirrhotic livers compared to healthy livers. Overexpression of PDE-5(7.7-fold; P = 0.006) was less pronounced in fibrotic livers. iNOS expression was only detected in fibrotic and cirrhotic livers. In healthy liver, PDE-5 protein was localized primarily in zone 3 hepatocytes and to a lesser extent in perisinusoidal cells. This zonation was disturbed in cirrhosis: PDE-5 protein expression in perisinusoidal cells was induced approximately 8-fold. In addition, PDE-5-expressing cells were also found in fibrous septa. Serum cGMP concentrations were reduced in rats with cirrhotic livers by approximately 40%. Inhibition of PDE-5 by Sildenafil caused a significant increase in serum cGMP concentrations [+ 64% in healthy rats(P = 0.024), + 85% in cirrhotic rats(P = 0.018)]. Concomitantly, the portal venous pressure was reduced by 19% in rats with liver cirrhosis. CONCLUSION Overexpression and abrogated zonation of PDE-5 likely contribute to the pathogenesis of cirrhotic portal hypertension. PDE-5 inhibition may therefore be a reasonable therapeutic approach for portal hypertension.

Efficient production of cyclic adenosine monophosphate from adenosine triphosphate by the N-terminal half of adenylate cyclase from Escherichia coli

In this study,we aimed at developing an efficient biocatalytic process for bio-production of cyclic adenosine monophosphate(c AMP)from adenosine triphosphate(ATP).First,adenylate cyclase from Escherichia coli MG1655(EAC)and Bordetella Pertussis(BAC)were expressed in E.coli BL21(DE3)and comparatively analyzed for their activities.As a result,EAC from E.coli MG1655 exhibited a higher activity.However,amount of EAC were obtained in an insoluble form.Therefore,we expressed the first 446 amino acids of EAC(EAC446)to avoid the inclusion body.The effects of induction temperature,incubation time,and incubation p H were further evaluated to improve the expression of EAC446.Subsequently,the reaction process for the production of c AMP with ATP as a starting material was investigated.As none of c AMP was detected in the whole-cell based biocatalytic process,the reaction catalyzed by the crude enzyme was determined for c AMP production.What's more,the reaction temperature,reaction p H,metal ion additives and substrate concentration was optimized,and the maximum c AMP production of 18.45 g·L^-1was achieved with a yield of 95.4%after bioconversion of 6 h.

Existence of Heme Oxygenase-carbon Monoxide-cyclic Guanosine Monophosphate Pathway in Human Trabecular Meshwork Cells In Vitro

To confirm the existence of heme oxygenase (HO)-carbon monoxide (CO)- cyclic guanosine monophosphate (cGMP) pathway in the cultured human trabecular meshwork cells (HTMCs) in vitro, and to evaluate the inductive role of hemin on this pathway, HTMCs of the third to fourth generation were cultured in vitro. Reverse transcripase-polymerase chain reaction (RT-PCR) was employed for detection of HO-1 and HO-2 mRNA. Immunohistochemical staining was used to detect HO-1 and HO-2 proteins. Hemin was added into the culture solution. The HO-1 mRNA levels were quantified by RT-PCR. The relative amount of carbon monoxide released into the media was measured with the quantifying carbon monoxide hemoglobin (HbCO) by spectrophotometry. Radioimmunoassay was used to determine changes of cGMP in HTMCs. The results showed that cultured cells had the specific characteristics of HTMCs. Both HO-1 and HO-2 genes were expressed in HTMCs, as well as HO-1 and HO-2 proteins in HTMCs. Hemin induced HO-1 mRNA, HbCO and cGMP in a dose-dependent manner. In conclusion, HO-CO-cGMP pathway exists in the cultured HTMCs and can be induced by hemin. Pharmacological stimulation of HO-CO-cGMP pathway may constitute a novel therapeutic approach to rescuing glaucoma.

Cyclic adenosine monophosphate signal pathway is involved in regulation of triacylglycerol biosynthesis following nitrogen deprivation in Chlamydomonas reinhardtii

The unicellular green alga,Chlamydomonas reinhardtii is a model organism for studying various biological processes,such as photosynthesis,flagellar motility,and lipid metabolism.To find some novel genes regulating the lipid metabolism under various stress conditions,the paromomycin resistance gene aphVIII was transferred into the genome of C.reinhardtii to establish a mutant library.Two genes mutated in two of the TAG-reduced mutants(Cre06.g278111 in M2 mutant,Cre06.g278110 in M6 mutants)were neighboring in the genome,and their expression levels were down-regulated in their corresponding mutants in parallel with their reduced TAG levels following N deprivation.The proteins encoded by these two genes(KCN11 by Cre06.g278111,ACYC3 by Cre06.g278110)contained a conversed cyclic mononucleotide phosphate(cNMP)binding protein and an adenylate domain,respectively.Since cNMP binding protein and adenylate domain have been known as important components of cyclic adenosine monophosphate(cAMP)signaling pathway,suggesting that these two genes might af fect cellular TAG biosynthesis through cAMP signal pathway.

Sevoflurane effects on cyclic adenosine monophosphate response element binding protein,phosphorylated cyclic adenosine monophosphate response element binding protein,and Livin expression in the cortex and hippocampus of a vascular cognitive impairment rat

BACKGROUND： Neuronal necrosis and apoptosis play important roles in the pathophysiology of cerebral ischemia and resulting cognitive impairment. However, inhibition of neuronal necrosis and apoptosis has been shown to attenuate cognitive impairment following cerebral ischemia. OBJECTIVE： To investigate the effects of sevoflurane on cyclic adenosine monophosphate response element binding protein （CREB）, phosphorylated CREB （pCREB）, and Livin expression in the cortex and hippocampus of a rat model of vascular cognitive impairment.DESIGN, TIME AND SETTING： A randomized, controlled experiment was performed in the Chongqing Key Laboratory of Neurology between June 2007 and July 2008.MATERIALS： Sevoflurane was provided by Abbott Laboratory, UK; Morris water maze was provided by Chinese Academy of Medical Sciences, China; goat anti-rat CREB, goat anti-rat pCREB and goat anti-rat Livin antibodies were provided by Biosource International, USA. METHODS： A total of 42 female, Wistar rats were randomly assigned to the following groups： sham operation, vascular cognitive impairment, and sevoflurane treatment. The vascular cognitive impairment rat model was established by permanent bilateral occlusion of both common carotid arteries, and 1.0 MAC sevoflurane was immediately administered by inhalation for 2 hours. MAIN OUTCOME MEASURES： CREB, pCREB, and Livin expression was measured in the cortex and hippocampus by Western blot and reverse transcription-polymerase chain reaction. Behavior was evaluated with Morris water maze. RESULTS： CREB, pCREB, and Livin expression in the sevoflurane treatment group was significantly greater than the vascular cognitive impairment group （P 〈 0.01）. However, expression of CREB and pCREB was significantly less in the sevoflurane treatment and vascular cognitive impairment groups, compared with the sham operation group （P 〈 0.01）. Livin expression in the sevoflurane treatment and vascular cognitive impairment groups was significantly greater than the sham operation group （P 〈 0.01）. Learning, memory, and behavior disorders were observed in the vascular cognitive impairment group. Sevoflurane treatment significantly improved these observed disorders. CONCLUSION： Sevoflurane improved cognitive impairment due to permanent bilateral occlusion of both common carotid arteries. Improved function was associated with increased CREB, pCREB, and Livin expression in the cortex and hippocampus.

Studies on Relationship between Serum Nitric Oxide and Plasma Cyclic Guanosine Monophosphate and Prolonged Bleeding after Medical Abortion as well as Prophylaxis and Treatment of Bleeding with Traditional Chinese Medicine

Objectives To study the relationship between serum nitric oxide (NO and plasma cyclic guanosine monophosphate (cGMP) and prolonged bleeding after medical abortion. Methods A total of 120 women having received medical abortions at random were recruited and divided into two groups: the one (Group A,n=60) taking 'Gong Fu Mixture(Uterus Recovering Mixture)' and the other (Group B,n=60) not taking it after abortion. On d 10, 20 and 30 after medical abortion, serum NO and plasma cGMP were tested before and after mifepristone administration and 10 d later by Gresis reaction method and radioimmunoassay respectively. Results NO concentration in serum and cGMP concentration in plasma decreased significantly after taking mifepristone given (P<0.05). Ten days later, the number of those with bleeding discontinuation in the group A was significantly greater than that in the group B (P<0.05). Serum NO level and plasma cGMP level in the group A decreased more significantly than those in the group B (P<0.05). Conclusion The slow decrease of serum NO and plasma cGMP is closely related to prolonged bleeding after medical abortion. “Gong Fu Mixture (uterus recovering mixture)” is effective in prevention and treatment of prolonged bleeding.

Inhibition of matrix metalloproteinase-9 secretion by dimethyl sulfoxide and cyclic adenosine monophosphate in human monocytes

BACKGROUND Matrix metalloproteinases(MMPs),including MMP-9,are an integral part of the immune response and are upregulated in response to a variety of stimuli.New details continue to emerge concerning the mechanistic and regulatory pathways that mediate MMP-9 secretion.There is significant evidence for regulation of inflammation by dimethyl sulfoxide(DMSO)and 3',5'-cyclic adenosine monophosphate(cAMP),thus investigation of how these two molecules may regulate both MMP-9 and tumor necrosis factorα(TNFα)secretion by human monocytes was of high interest.The hypothesis tested in this study was that DMSO and cAMP regulate MMP-9 and TNFαsecretion by distinct mechanisms.AIM To investigate the regulation of lipopolysaccharide(LPS)-stimulated MMP-9 and tumor necrosis factorαsecretion in THP-1 human monocytes by dimethyl sulfoxide and cAMP.METHODS The paper describes a basic research study using THP-1 human monocyte cells.All experiments were conducted at the University of Missouri-St.Louis in the Department of Chemistry and Biochemistry.Human monocyte cells were grown,cultured,and prepared for experiments in the University of Missouri-St.Louis Cell Culture Facility as per accepted guidelines.Cells were treated with LPS for selected exposure times and the conditioned medium was collected for analysis of MMP-9 and TNFαproduction.Inhibitors including DMSO,cAMP regulators,and anti-TNFαantibody were added to the cells prior to LPS treatment.MMP-9 secretion was analyzed by gel electrophoresis/western blot and quantitated by ImageJ software.TNFαsecretion was analyzed by enzyme-linked immuno sorbent assay.All data is presented as the average and standard error for at least 3 trials.Statistical analysis was done using a two-tailed paired Student t-test.P values less than 0.05 were considered significant and designated as such in the Figures.LPS and cAMP regulators were from Sigma-Aldrich,MMP-9 standard and antibody and TNFαantibodies were from R&D Systems,and amyloid-βpeptide was from rPeptide.RESULTS In our investigation of MMP-9 secretion from THP-1 human monocytes,we made the following findings.Inclusion of DMSO in the cell treatment inhibited LPSinduced MMP-9,but not TNFα,secretion.Inclusion of DMSO in the cell treatment at different concentrations inhibited LPS-induced MMP-9 secretion in a dosedependent fashion.A cell-permeable cAMP analog,dibutyryl cAMP,inhibited both LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the adenylyl cyclase activator forskolin inhibited LPS-induced MMP-9 and TNFαsecretion.Pretreatment of the cells with the general cAMP phosphodiesterase inhibitor IBMX reduced LPS-induced MMP-9 and TNFαin a dose-dependent fashion.Pre-treatment of monocytes with an anti-TNFαantibody blocked LPSinduced MMP-9 and TNFαsecretion.Amyloid-βpeptide induced MMP-9 secretion,which occurred much later than TNFαsecretion.The latter two findings strongly suggested an upstream role for TNFαin mediating LPS-stimulate MMP-9 secretion.CONCLUSION The cumulative data indicated that MMP-9 secretion was a distinct process from TNFαsecretion and occurred downstream.First,DMSO inhibited MMP-9,but not TNFα,suggesting that the MMP-9 secretion process was selectively altered.Second,cAMP inhibited both MMP-9 and TNFαwith a similar potency,but at different monocyte cell exposure time points.The pattern of cAMP inhibition for these two molecules suggested that MMP-9 secretion lies downstream of TNFαand that TNFαmay a key component of the pathway leading to MMP-9 secretion.This temporal relationship fit a model whereby early TNFαsecretion directly led to later MMP-9 secretion.Lastly,antibody-blocking of TNFαdiminished MMP-9 secretion,suggesting a direct link between TNFαsecretion and MMP-9 secretion.

Adenosine cyclic phosphate with ultrasonic-assisted pectinase extraction alleviated allergic reactions in RBL-2H3 through inhibiting the influx of intracellular Ca^(2+)

Jujube contains abundant cyclic adenosine monophosphate(cAMP)and the ultrasonic-assisted pectinase extraction(UAPE)conditions for obtaining the maximum cAMP yield from jujube were optimized.Orthogonal array design was applied to evaluate the effects of 4 variables by UAPE on cAMP yield.The results showed that the optimal cAMP yield(783.0μg/g)was derived at ratio of liquid to solid 5 mL/g,ratio of pectinase to raw material 1.5%,time 60 min and temperature 40℃.Moreover,the effect of cAMP on the anti-allergic function of action induced by immunoglobulin E(IgE)and its meschanism was investigated through establishing the sensitized cell model in rat basophilic leukemia(RBL-2 H3)cells using dinitrophenylated(DNP)-bovine serum albumin(BSA)-IgE.The results showed that cAMP interfered with sensitized cells,effectively inhibited the occurrence of basophil degranulation in dose dependence,and significantly reduced the activity ofβ-hexosamindase(β-hex),at the optimal concentration of 50μg/mL.The level of anti-inflammatory factor interleukin-10(IL-10)was promoted and the content of pro-inflammatory factor tumor necrosis factor-α(TNF-α)was suppressed by cAMP.In addition,influx of intracellular Ca^(2+) was repressed effectively.Our results demonstrate that jujube cAMP regulated the cytokine balance in the allergy pathway through blocking the influx of extracellular Ca^(2+),with the prevention of allergy symptoms.

Effects of Zuogui Pill(左归丸) and Yougui Pill(右归丸) on the Expression of Brain-Derived Neurotrophic Factor and Cyclic Adenosine Monophosphate/Protein Kinase A Signaling Transduction Pathways of Axonal Regeneration in Model Rats with Experimental Autoimm

Objective：To study the effects of Zuogui Pill（左归丸,ZGP）and Yougui Pill（右归丸,YGP）on the expressions of brain-derived neurotrophic factor（BDNF）and cyclic adenosine monophosphate（cAMP）/protein kinase A（PKA）signaling of axonal regeneration in the Lewis rats with experimental autoimmune encephalomyelitis（EAE）,in order to explore the possible mechanism of ZGP and YGP on promoting axonal regeneration.Methods：The rats were randomly divided into normal control（NC）,model（MO）,prednisone acetate（PA）,ZGP and YGP groups.The EAE model of rat was established by injecting antigen containing myelin basic protein（MBP）68-86.The brain and spinal cord were harvested on the 14th and 28th day postimmunization（PI）,the protein and mRNA expression of BDNF and PKA in the brain and spinal cord of rats were detected by Western blot analysis and real-time quantitative polymerase chain reaction（PCR）,and the cAMP levels were detected by using enzyme-immunoassay method.Results：（1）On the 28th day PI,the mRNA expression of BDNF in brain white matter and spinal cord of rats in ZGP and YGP groups were up-regulated,especially in YGP group（P〈0.05 or P〈0.01）.（2）On the 14th day PI,the cAMP levels in brain white matters significantly increased in PA and YGP groups compared with MO group（P〈0.05 or P〈0.01）,and the cAMP level in YGP group was higher than that in ZGP group（P〈0.05）.The cAMP level in spinal cord also significantly increased in YGP group compared with MO,PA and ZGP groups,respectively（P〈0.01）.（3）On the 14th day PI,the PKA expression in spinal cord of rats in ZGP group was significantly decreased compared with MO and YGP groups,respectively（P〈0.05）.（4）On the 28th day PI,there was a positive correlation between cAMP and PKA expression in the brain white matter of YGP rats.Conclusions：The results suggest that ZGP and YGP may promote axonal regeneration by modulating cAMP/PKA signal transduction pathway,but the targets of molecular mechanism of ZGP may be different from those of YGP.

Cyclic adenosine monophosphate signal pathway in targeted therapy of lymphoma

Objective To review the role of cyclic adenosine monophosphate （cAMP） signal pathway in the pathogenesis of iymphoma and explore a potential lymphoma therapy targeted on this signaling pathway. Data sources The data cited in this review were mainly obtained from the articles listed in Medline and PubMed, published from January 1995 to June 2009. The search terms were ＂cAMP＂ and ＂lymphoma＂. Study selection Articles regarding the role of the cAMP pathway in apoptosis of lymphoma and associated cells and its potential role in targeted therapy of lymphoma. Results In the transformation of lymphocytic malignancies, several signal pathways are involved. Among of them, the cAMP pathway has attracted increasing attention because of its apoptosis-inducing role in several lymphoma cells, cAMP pathway impairment is found to influence the prognosis of lymphoma. Targeted therapy to the cAMP pathway seems to be a new direction for lymphoma treatment, aiming at restoring the cAMP function. Conclusions cAMP signal pathway has different effects on various lymphoma cells, cAMP analogues and phosphodiesterase 4B （PDE4B） inhibitors have potential clinical significance. However, many challenges remain in understandinq the various roles of such agents.

Effects of Meglumine Cyclic Adenylate Pretreatment on Systemic inflammatory Response Syndrome Induced by Lipopolysaccharide in Rats

Studies showed that the use of cyclic adenosine monophosphate(cAMP) substitutes or intracellular c AMP activators increased intracellular cAMP level, causing anti-inflammatory effects. This study was to investigate the effects of pretreatment with meglumine cyclic adenylate(MCA), a compound of meglumine and cAMP, on systemic inflammation induced by lipopolysaccharide(LPS) in rats. Eighteen adult male Sprague-Dawley rats were randomly divided into 3 groups(n=6 each): control group(NS group), LPS group(LPS group) and LPS with MCA pretreatment group(MCA group). Systemic inflammation was induced with LPS 10 mg/kg injected via the femoral vein in LPS and MCA groups. In MCA group, MCA 2 mg/kg was injected via the femoral vein 20 min before LPS injection, and the equal volume of normal saline was given in NS and LPS groups at the same time. Three hours after LPS injection, the blood samples were taken from the abdominal aorta for determination of plasma concentrations of TNF-α, IL-1, IL-6, IL-10, cAMP by ELISA and NF-κBp65 expression by Western blotting. The experimental results showed that inflammatory and antiinflammatory indices were increased in LPS group compared to NS group; inflammatory indices were declined and anti-inflammatory indices were increased in MCA group relative to LPS group. Our study suggested that MCA pretreatment may attenuate LPS-induced systemic inflammation.

Low expression of vascular endothelial growth factor and high serum level of cyclic guanine monophosphate as the risk factors of femoral head osteonecrosis in alcohol-exposed Wistar rat

Purpose:Severe damage to the femoral head in patients with osteonecrosis has a high impact on morbidity.Despite early diagnosis,the treatment outcome is still unsatisfactory.This study aimed to explore the expression of vascular endothelial growth factor(VEGF)and cyclic guanine monophosphate(cGMP)serum level as the risk factors of femoral head osteonecrosis in alcohol-exposed Wistar rats.Methods:This was an exper imental study using randomized post-test only control group design,with samples using 10-14 weeks Wistar male rats.Rats were then divided into 6 groups:3 groups without intervention,and 3 groups with intervention using 40%alcohol given perorally.Each one group from intervention and control group was euthanized by the end of the week for 3 consecutive weeks.Proximal femurs were examined under microscope for osteonecrosis,immunohistochemically for VEGF,and blood serum for cGMP levels.Results:VEGF expression in the femoral head of alcohol-exposed Wistar rats was lower than those not exposed to alcohol(p<0.005).Blood serum cGMP levels of alcohol-exposed Wistar rats were higher than those not exposed to alcohol(p<0.005).The number of necrotic osteocytes in the femoral head of Wistar rats exposed to alcohol was greater than those not exposed to alcohol(p<0.005).There are significant differences between VEGF,cGMP levels,and number of necrotic osteocytes in the control group and treatment at 1st,2nd'and 3rd week(p<0.005).Conclusions:Based on the result of this study,VEGF and cGMP may be considered as diagnostic bio-markers for alcohol-induced femoral head osteonecrosis.

Cyclic Nucleotide Structural Differentiation of Compounds Modulating Apoptosis and Drug Resistance

Carcinogenesis is associated with malfunction in the cGMP-mediated regulation of cytosolic Ca2+ and reactive oxygen species. Chemotherapy resistant cancer cells are re-sensitised to apoptosis by the action of a substantial number of natural compounds on cell membrane multidrug resistant proteins. Chemical structures of pro-apoptotic and anti-apoptotic compounds demonstrate relative molecular similarity to cGMP. This study uses a computational chemistry program to investigate molecular similarity within cGMP and chemo-preventative structures. Chemotherapeutic drugs and resistance modulators provide multiple fits to a nucleotide template that differ in their relationship to the cyclised ring of cGMP. The alternative fits of drug and modulator structures may relate to the development and unblocking of apoptosis and drug resistance.

Molecular Similarity within Carcinogen and Guanine Cyclic Nucleotide Structures

Tumor promoters, apoptosis and autophagy modulators, chemotherapy drugs, and endogenous steroids demonstrate molecular similarity relative to cyclic nucleotide structure. This study explores relative molecular similarity within established human carcinogen structures using computational chemistry software. Molecular structures of conventional carcinogenic drugs and industrial agents demonstrate molecular similarity with a focus on the guanine base and nucleotide cyclized ring. Structures of volatile and gaseous anesthetic carcinogens do not conform to conventional 3-point pharmacophore-based fits characteristic of receptor-binding drugs. The results of this study provide some insight into how carcinogen structures may interact with endogenous compounds to disrupt cyclic nucleotide-driven homeostatic mechanisms.