Inhibition of Alcoholic Liver Injury by Paeonol Through Eubacterium-mediated TGR5/PKA/CREB Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate whether paeonol exerts a protective effect on mice with alcoholic liver injury by regulating the takeda G-protein-coupled receptor 5 （TGR5）/protein kinase A （PKA）/cAMP response binding element （CREB） signaling pathway mediated by Eubacterium. MethodC57BL/6 mice were randomly divided into five groups： normal group， model group， paeonol group （480 mg·kg-1）， antibiotic group （Abs group）， and antibiotic + paeonol group. Lieber-DeCarli liquid was used to feed C57BL/6 mice on the second day of modeling for 10 days. The blood lipids， liver function， inflammatory factors， and oxidative stress levels in mice were measured. Hematoxylin-eosin staining （HE） and oil red O staining were used to observe the morphological changes and fat accumulation in liver tissue. 16S rDNA sequencing was used to detect the diversity of intestinal microbiota in the blank， model， and paeanol groups. Western blot was used to detect the effect of paeonol on the expression levels of protein related to the signaling pathway of atresia band protein 1 （ZO-1）， Claudin-1， and TGR5/PKA/CREB in mouse ileal tissue. ResultCompared with those in the blank group， the blood lipids， liver function， oxidative stress levels， and the expression of inflammatory factors in the model group increased （P<0.01）， and the liver fat vacuoles were obvious. The ileal mucosa was seriously damaged， and the protein contents of ZO-1， Claudin-1， and TGR5/PKA/CREB in the ileal tissue decreased significantly （P<0.01）. The intestinal microbiota changed， and the proteobacteria phylum increased significantly. The ratio of Bacteroidetes to Firmicutes decreased. The relative abundance of Dubosiella newyorkensis， Lactobacillus， Bifidobacterium， and other genera decreased， while the relative abundance of Escherichia-Shigella， Morganella， Providencia， and Proteus increased significantly. Compared with the model group， paeonol significantly reduced the blood lipids， liver function， oxidative stress levels， and expression of inflammatory factors in mice with alcohol diet-induced liver injury （P<0.05）， decreased liver fat vacuoles， improved and restored the ileal intestinal barrier， and restored the normal structure of hepatocytes and ileal cells. The intestinal microbiota disorder caused by alcohol was improved， and the relative abundance of beneficial bacteria such as Eubacterium spp. was increased. The protein expression levels of ZO-1， Claudin-1， and TGR5/PKA/CREB in ileal tissue were increased （P<0.05）. ConclusionPaeonol has a protective effect on alcoholic liver injury in mice， and the mechanism of action is achieved by regulating the Eubacterium-mediated TGR5/PKA/CREB signaling pathway to ensure anti-inflammatory effect and improve the intestinal barrier.

Study on the Analgesic Effect and Mechanism of Buyang Huanwu Decoction on Diabetic Peripheral Neuropathy Rats / 广州中医药大学学报

Objective To investigate the analgesic effect and mechanism of Buyang Huanwu Decoction on diabetic peripheral neuropathy(DPN)rats.Methods Sixty rats were divided into normal group,model group,low-,medium-and high-dose groups of Chinese medicine,and high-dose + H-89[protein kinase A(PKA)inhibitor]group,with 10 rats in each group.Except for the normal group,rats in all other groups were fed with high-fat and high-sugar chow combined with intraperitoneal injection of streptozotocin(STZ)method to construct DPN model.At the end of drug administration,the foot thermal pain threshold of rats was detected,the motor nerve conduction velocity(MNCV)and sensory nerve conduction velocity(SNCV)of rats was measured,the intraepidermal nerve fiber(IENF)in the epidermis was observed by immunohistochemistry,and serum fasting insulin(FINS),total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),insulin resistance index(HOMA-IR),and the interleukin(IL)-1β,IL-6,tumor necrosis factor α(TNF-α),vascular endothelial growth factor(VEGF),angiopoietin 1(Ang-1),CD34 levels,cyclic adenosine monophosphate(cAMP)concentration in the sciatic nerve tissues were detected by enzyme-linked immunosorbent assay(ELISA),and Western Blot assay to detect the PKA and the carbohydrate responsive element binding(CREB)in the sciatic nerve tissues.Results Compared with the normal group,foot thermal pain threshold,TC,TG,LDL-C,HOMA-IR,IL-1β,IL-6 and TNF-α levels were significantly increased in the model group(P＜0.05),HDL-C,FINS,VEGF,Ang-1,CD34,IENF,MNCV and SNCV values,cAMP concentration levels,PKA and CREB phosphorylation levels were significantly reduced(P＜0.05).Compared with the model group,the above indexes were significantly improved in the low-,medium-and high-dose groups of Chinese medicine(P＜0.05)in a dose-dependent manner.Compared with the Chinese medicine high-dose + H-89 group,all the indexes were reversed in the Chinese medicine high-dose group.Conclusion Buyang Huanwu Decoction can improve insulin resistance and lipid metabolism,reduce limb pain,improve local microcirculation disorder,and protect nerve function in DPN rats,which reflects the therapeutic characteristics of"activating blood circulation and relieving pain".The pain-relieving effect of Buyang Huanwu Decoction may be related to the improvement of local microcirculation,inhibition of inflammatory factor release and regulation of cAMP/PKA/CREB signaling pathway protein expression.

Effect of baicalin regulating cAMP/PKA/CREB signaling pathway on skin barrier function in eczema rats / 天津医药

Objective To investigate the effect of baicalin(BA)regulating cyclic adenosine phosphate(cAMP)/protein kinase A(PKA)/cAMP response elemen-binding protein(CREB)pathway on skin barrier function in eczema rats.Methods SD rats were randomly divided into the control group(NC group),the model group,the low-dose BA group(BA-L group,25 mg/kg),the medium-dose BA group(BA-M group,50 mg/kg),the high-dose BA group(BA-H group,100 mg/kg),the prednisone group(PNS group,25 mg/kg),the BA-H+cAMP inhibitor(SQ22536)group(100 mg/kg+2.13 mg/kg)and the BA-H+PKA inhibitor(H-89)group(100 mg/kg+5 mg/kg),12 animals in each group.Except for the NC group,eczema rat model was constructed in the other groups.Two days after successful modeling,drug administration was performed in groups.Changes of eczema area and severity index(EASI)score,transcutaneous water loss(TEWL)and cuticle water content(WCSC)were detected.Enzyme-linked immunosorbent assay(ELISA)was used to detect levels of immunoglobulin E(IgE),interferon-γ(IFN-γ)and interleukin-4(IL-4)in rat serum and the expression of cAMP protein in rat back lesions.HE staining was used to detect pathological changes of skin lesions on the back of rats.Western blot assay was used to detect aquaporin 3(AQP3),cathelicidin related antimicrobial peptide(CRAMP),p-PKA,p-CREB protein expression in rat back lesions.Results Compared with the NC group,rats had serious pathological lesions on the back of the tested area,increased EASI score,TEWL,IgE and IL-4 levels,and decreased WCSC,IFN-γ,AQP3,CRAMP,cAMP,p-PKA and p-CREB protein levels in the model group(P<0.05).Compared with the model group,pathological lesion of the tested area in the back of rats was relieved,and EASI score,TEWL,IgE and IL-4 levels were decreased,WCSC,IFN-γ levels,AQP3,CRAMP,cAMP,p-PKA and p-CREB protein were increased in the BA-L group,the BA-M group,the BA-H group and the PNS group(P＜0.05).Changes of above indexes in the BA-L group,the BA-M group,the BA-H group were dose-dependent.SQ22536 or H-89 attenuated the improvement effect of high dose BA on skin barrier function in eczema rats.Conclusion BA may improve skin barrier function in eczema rats by activating cAMP/PKA/CREB signaling pathway.

Sal idroside Modulates cAMP/PKA/CREB Signaling Pathway to Inhibit Ci splatin-induced Damages of Cochlear Hair Cells and Spiral Ganglion Neurons in Mice / 听力学及言语疾病杂志

Objective To investigate the ameliorating effect of salidroside(SAL)on cisplatin(CIS)-induced damages of cochlear hair cells(CHC)and spiral ganglion neurons(SGNs)and its relationship with cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/cAMP response element binding protein(CREB)pathway.Methods The cochlear basilar membranes of newborn C 57BL/6 mice were isolated and separated into control(C)group,CIS group,SAL group,SAL+SQ22536(cAMP inhibitor)group and SAL+H-89(PKA inhibitor)group,20 per group.Immunofluorescence staining was applied to observe the damages of CHC and SGNs.The kits were applied to detect the contents of ROS and cAMP in the basement membrane of the cochlea.Western blot was applied to detect the protein levels of PKA,p-CREB,CREB,Bcl-2,BDNF,and NF-M.Results CHC in CIS group were disorderly arranged and enlarged in size,SGNs had fragmented nuclei and lost neurites.SAL alleviated the damages of CHC and SGNs.Compared with the C group,the numbers of CHC and SGNs in the CIS group were less(P＜0.05),the contents of ROS and cAMP,and the levels of PKA,BDNF,NF-M,Bcl-2 proteins and p-CREB/CREB were higher(P＜0.05).Compared with the CIS group,the numbers of CHC and SGNs in the SAL group were higher(P＜0.05),the content of ROS was lower(P＜0.05),the content of cAMP,and the levels of PKA,BD-NF,NF-M,Bcl-2 proteins and p-CREB/CREB were higher(P＜0.05).Both SQ22536 and H-89 reversed the pro-tective effects of SAL on CHC and SGNs.Conclusion SAL may promote the expression of anti-apoptotic proteins and neuroprotective factors by activating the cAMP/PKA/CREB pathway to alleviate the damages of CHC and SGNs caused by CIS.

Impact of evodiamine on retinal injury in diabetic rats by regulating cyclic adenosine monophosphate/protein kinase A signaling pathway / 眼科新进展

Objective To investigate the effect of evodiamine(EVO)on retinal injury in diabetic rats by regulating the cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)signaling pathway.Methods Totally 96 Sprague-Dawley rats(192 eyes)were divided into the negative control(NC)group,Model group,low-dose EVO(EVO-L)group,medium-dose EVO(EVO-M)group,high-dose EVO(EVO-H)group,calcium dobesilate(CD)group,SQ22536 group and EVO-H+SQ22536 group,with 12 rats in each group.Rats in the NC group were intraperitoneally injected with physiological saline instead of streptozotocin,and diabetic retinopathy models were established in all other groups.After successful mod-eling,the drug was administered once a day for 4 weeks.The blood glucose level of rats in each group was measured by blood glucose meter;HE staining was applied to detect the pathological changes of the retina of rats;TUNEL staining was adopted to detect the apoptosis of ganglion cells in the retina of rats;the levels of superoxide dismutase(SOD),malondial-dehyde(MDA),tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and cAMP in the retina of rats were detected;West-em blot was used to detect the protein expressions of Bcl-2 associated X protein(Bax),P53 and phosphorylated protein ki-nase A(p-PKA)in the retina of rats.Results Compared with the NC group,the pathological injury of the retina in the Model group was more serious;the blood glucose,apoptosis rate of retinal ganglion cells,MDA,TNF-α,IL-6,Bax and P53 protein expressions increased,and the SOD,cAMP and p-PKA/PKA protein expression decreased,with statistically significant differences(all P＜0.05).Compared with the Model group,the pathological injury of the retina was relieved,the blood glucose,apoptosis rate of retinal ganglion cells,MDA,TNF-α,IL-6,Bax and P53 protein expressions decreased,and the SOD,cAMP and p-PKA/PKA protein expression increased in the EVO-L group,EVO-M group,EVO-H group and CD group,with statistically significant differences(all P＜0.05).Compared with the Model group,the retinal tissue of the SQ22536 group was severely damaged,the blood glucose,apoptosis rate of retinal ganglion cells,MDA,TNF-α,IL-6,Bax and P53 protein expressions increased,and the SOD,cAMP,p-PKA/PKA protein expression decreased,with statistically significant differences(all P＜0.05).Compared with the EVO-H group,the EVO-H+SQ22536 group showed more serious pathological injury of retinal tissue,increased blood glucose,apoptosis rate of retinal ganglion cells,MDA,TNF-α,IL-6,Bax and P53 protein expressions,and decreased SOD,cAMP and p-PKA/PKA protein expression,and the differences were statistically significant(all P＜0.05).Conclusion EVO may alleviate retinal injury in diabetic rats by activating the cAMP/PKA signaling pathway.

Hei Xiaoyaosan Affects Synaptic Plasticity of Hippocampal Neurons in APP/PS1 Double Transgenic Mice of AD via cAMP/PKA/NMDAR Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the effect and mechanism of Hei Xiaoyaosan in modulating the synaptic plasticity in APP/PS1 mice by regulating the cyclic adenosine monophosphate （cAMP）/protein kinase A （PKA）/N-methyl-D-aspartate receptor （NMDAR） signaling pathway. MethodTwelve 4-month-old male C57BL/6J mice were selected as the blank control group， and 60 4-month-old male APP/PS1 double transgenic mice were randomized into model， KW-6002 （adenosine receptor antagonist， 3 mg·kg-1）， and high-， medium-， and low-dose （22.10， 11.05， 5.53 g·kg-1， respectively） Hei Xiaoyaosan groups， with 12 mice in each group. Mice were administrated with corresponding drugs for 90 days. Transmission electron microscopy was employed to observe the synaptic ultrastructure of hippocampal neurons， and Golgi staining was used to observe the dendritic spine density of neurons in hippocampal CA1 region. Western blot was employed to measure the protein levels of cAMP， PKA， N-methyl-D-aspartate receptors 1， 2A， and 2B （NR1， NR2A， and NR2B， respectively）， postsynaptic density protein 95 （PSD95）， and synapsin 1 （SYN1）. Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） was performed to determine the mRNA levels of cAMP， PKA， and NR1. Enzyme-linked immunosorbent assay was employed to determine the content of interleukin-12 （IL-12） and interleukin-4 （IL-4） in the hippocampus. ResultCompared with the blank group， the model group showed blurred boundaries between presynaptic membrane and postsynaptic membrane in hippocampal CA1 region， reduced and scattered synaptic vesicles， and decreased density of postsynaptic membrane， and irregular， disarranged， and loosened dendritic spines of neurons in hippocampal CA1 region （P<0.01）. In addition， the model group presented down-regulated protein levels of cAMP， PKA， NR1， NR2A， NR2B， PSD95， and SYN1 and mRNA levels of cAMP， PKA， and NR1， elevated IL-12 level， and lowered IL-4 level in the hippocampus （P<0.01）. Compared with the model group， the drug intervention groups showed clear and intact boundaries between presynaptic membrane and postsynaptic membrane in hippocampal CA1 region， increased synaptic vesicles with dense arrangement， increased density of postsynaptic membrane， and improved morphology， arrangement， and density of neuronal dendritic spines （P<0.05， P<0.01）. In addition， the drug interventions up-regulated the protein levels of cAMP， PKA， NR1， NR2A， NR2B， PSD95， and SYN1 （P<0.05，P<0.01） and mRNA levels of cAMP， PKA， and NR1 （P<0.01）， lowered the IL-12 level （P<0.01）， and elevated the IL-4 level （P<0.01） in the hippocampus. ConclusionHei Xiaoyaosan can improve the structure and morphology of hippocampal neurons in APP/PS1 mice by activating the cAMP/PKA/NMDAR signaling pathway and repairing synaptic plasticity.

Study on the mechanism of Yishen daluo decoction in alleviating nervous system inflammation in EAE model mice / 中国药房

OBJECTIVE To study the effects of Yishen daluo decoction on inflammatory factors and cyclic adenosine monophosphate（cAMP）/protein kinase A （PKA）/cAMP response element binding protein （CREB） signal pathway in experimental autoimmune encephalomyelitis （EAE） model mice by inhibiting the expressions of β-arrestin1， and to explore the mechanism of Yishen daluo decoction in the treatment of EAE. METHODS Sixty mice were randomly divided into normal group， model group， TCM group （Yishen daluo decoction 20 g/kg）， positive control group （prednisone acetate 3.9 mg/kg）， β-arrestin1 siRNA adeno- associated virus （AAV-β） group， AAV-β+TCM group， with 10 mice in each group. Except for normal group， EAE model was made in other groups. AAV-β group and AAV-β+TCM group were injected with AAV-β via tail vein to interfere with the expression of β -arrestin1 protein. Starting from the 8th day of modeling， they were given corresponding drug solution/normal saline intragastrically， once a day， for consecutive 14 days. The neurological function score of mice was detected； the pathological and morphological changes were observed in the brain and spinal cord tissues of mice； the serum levels of inflammatory factors [interleukin-2 （IL-2）， IL-23， interferon-γ （IFN-γ）] in mice were determined； the expressions of β-arrestin1， cAMP， PKA and CREB in brain and spinal cord were detected. RESULTS Compared with normal group， neurological function scores， serum levels of inflammatory factors， and protein expressions of β-arrestin1 in brain and spinal cord were significantly increased （P＜0.05 or P＜ 0.01）； protein expressions of PKA， CREB and cAMP in brain and spinal cord were decreased significantly（P＜0.05 or P＜0.01）. The deep staining of cellular shrinkage and aggregation of inflammatory cells were observed in most neurons of the brain and spinal cord， with varying degrees of demyelinating. Compared with model group， the neurological function scores， pathological changes in brain and spinal cord tissues， and most indicators （except for CREB and cAMP proteins in the brain tissue of AAV-β group） were significantly reversed （P＜0.05 or P＜0.01）.Compared with AAV- β group， the neurological function scores， the levels of IFN-γ in serum and β-arrestin1 in spinal cord were significantly decreased （P＜0.05 or P＜0.01）， PKA and cAMP in brain and spinal cord tissues were significantly increased in AAV- β +TCM group （P＜0.05 or P＜0.01）. CONCLUSIONS Yishen daluo decoction can inhibit the expression of β-arrestin1 in the central nervous system thus activating the cAMP/PKA/CREB signaling pathway， relieving nervous system inflammation， and ultimately alleviates the symptoms of EAE.

Guiqi Baizhu Prescription Combined with Oxaliplatin Protects Intestinal Barrier of Tumor-bearing Mice with Gastric Cancer by Regulation of VIP/cAMP/PKA/AQP Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the protective effect of Guiqi Baizhu prescription combined with oxaliplatin on the intestinal barrier of tumor-bearing mice with gastric cancer by regulating downstream aquaporin 3 （AQP3） and aquaporin 4 （AQP4） through the vasoactive intestinal peptide （VIP）/cyclic adenosine monophosphate （cAMP）/protein kinase A （PKA） signaling pathway. MethodThe gastric cancer cell lines MFC with a density of 1×107/mL were prepared into cell suspension. The tumor-bearing mouse model of gastric cancer was established by inoculating 0.2 mL cell suspension under the right axilla of mice. After successful modeling， mice were randomly divided into 5 groups， namely， model group， oxaliplatin group （10 mg·kg-1）， and high， medium， and low-dose oxaliplatin + Guiqi Baizhu prescription groups （17.68， 8.84， 4.42 g·kg-1）， with 10 mice in each group， and the remaining 10 mice were set as a blank group. Mice in each group were treated with Chinese medicine， oxaliplatin， or normal saline by gavage or intraperitoneal injection for 14 d. The next day after the last dose， blood was taken from the eyeball to separate serum and take colonic samples. Hematoxylin-eosin （HE） staining was used to observe the changes in tissue morphology. The content of D-lactate acid （D-LA） and diamine oxidase （DAO） in the serum was determined by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expressions of VIP， cAMP， PKA， AQP3， and AQP4 were detected by Real-time quantitative polymerase chain reaction （Real-time PCR） and Western blot， respectively. ResultCompared with the blank group， the model group showed edema in the colonic submucosa， disordered arrangement of intestinal glands in the mucosal layer， loss of goblet cells， infiltration of inflammatory cells， and villus shedding. However， there were different degrees of improvement in each administration group. As compared with the blank group， the serum levels of DAO and D-LA in the model group were significantly increased （P<0.01）. As compared with the model group， the levels of DAO and D-LA in the high-dose oxaliplatin + Guiqi Baizhu prescription group and the level of D-LA in the medium-dose oxaliplatin + Guiqi Baizhu prescription group were decreased （P<0.05， P<0.01）. As compared with the oxaliplatin group， the levels of D-LA in the high and medium-dose oxaliplatin + Guiqi Baizhu prescription groups were decreased （P<0.05）， and the levels of DAO and D-LA in other administration groups were decreased as well， but the difference had no statistical significance. As compared with the blank group， the mRNA and protein expression levels of VIP， cAMP， PKA， AQP3， and AQP4 in the model group were significantly decreased （P<0.05， P<0.01）. As compared with the model group， the mRNA and protein expression levels of VIP， cAMP， PKA， AQP3， and AQP4 in each administration group were increased， and those in the high-dose oxaliplatin + Guiqi Baizhu prescription group were significantly increased （P<0.05， P<0.01）， while the protein expression level of cAMP in the medium-dose oxaliplatin + Guiqi Baizhu prescription group were increased （P<0.05）. As compared with the oxaliplatin group， the protein expression levels of cAMP in the high-dose oxaliplatin + Guiqi Baizhu prescription group were increased （P<0.05）， and the mRNA and protein expressions of these indexes in the other groups were also increased but the differences were not statistically significant. ConclusionGuiqi Baizhu prescription combined with oxaliplatin can regulate AQP3 and AQP4 through the VIP/cAMP/PKA signaling pathway to protect the intestinal barrier of tumor-bearing mice with gastric cancer.

Mechanism of Shaoyaotang in Regulating Water Metabolism and Intestinal Epithelial Permeability in Ulcerative Colitis Through cAMP/PKA/CREB Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the role of cyclic adenosine monophosphate （cAMP）/protein kinase A （PKA）/cAMP-response element binding protein （CREB） signaling pathway in water metabolism and intestinal epithelial permeability in ulcerative colitis （UC） and the intervention mechanism of Shaoyaotang based on the theory of large intestine governing fluids. MethodSixty male SD rats were divided into blank group， model group， mesalazine group （0.42 g·kg-1）， Shaoyaotang low-dose group （11.1 g·kg-1）， Shaoyaotang medium-dose group （22.2 g·kg-1） and Shaoyaotang high-dose group （44.4 g·kg-1）， with 10 in each group. The UC rat model of internal retention of dampness-heat was established by compound factors. The blank group and the model group were given normal saline （ig）. The mesalazine group was given mesalazine （ig）， and Shaoyaotang low-， medium- and high-dose groups were administrated with corresponding doses of Shaoyaotang （ig）. The treatment lasted for 14 days. The diarrhea score and fecal moisture content of rats in each group were observed. The contents of diamine oxidase （DAO） and D-lactic acid in plasma were detected by enzyme-linked immunosorbent assay （ELISA）. The protein expressions of aquaporin （AQP）8， AQP4， ZO-1 and Occludin in colon tissues were detected by immunohistochemistry， while those of cAMP， PKA and CREB in colon tissues were determined by Western blot. ResultCompared with the normal group， the model group had elevated diarrhea score and fecal moisten content （P<0.01）， increased contents of DAO and D-lactic acid in plasma （P<0.01） and decreased protein expressions of ZO-1， Occludin， AQP8， AQP4， cAMP， PKA and CREB in colon （P<0.01）. Compared with the conditions in the model group， the contents of DAO and D-lactic acid in plasma in each administration groups were lower （P<0.01）， while the protein expressions of ZO-1， Occludin， AQP8， AQP4， cAMP， PKA and CREB in colon were higher （P<0.01）. ConclusionShaoyaotang alleviates the diarrhea in UC， probably through activating cAMP/PKA/CREB signaling pathway， up-regulating expressions of AQPs， enhancing tight junctions in intestinal epithelium and thus improving the water metabolism in colon and the intestinal mucosal permeability.

Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex Combination Alleviates Slow Transit Constipation due to Yang Deficiency in Rats via Regulating VIP/cAMP/PKA/AQP Pathway in Colon / 中国实验方剂学杂志

ObjectiveTo investigate the effect and mechanism of Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex in regulating the intestinal function in the rat model of slow transit constipation （STC） due to yang deficiency via the vasoactive intestinal peptide （VIP）/cathelicidin antimicrobial peptide （cAMP）/protein kinase A （PKA）/aquaporin （AQP） pathway. MethodSD rats were randomized into 6 groups （n=6）， including a control group， a model group， high-， medium-， and low-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex groups， and a prucalopride group. Other groups except the control group were treated with loperamide hydrochloride combined with ice water by gavage for the modeling of STC due to yang deficiency. The number of fecal pellets， time to the first black stool defecation， fecal water content， intestinal propulsion rate， and score of fecal properties were recorded in each group. At the end of the treatment， the colon was stained with hematoxylin-eosin （HE） to reveal the histopathological changes and Alcian blue/periodic acid-Schiff （AB-PAS） to reveal the secretion of colonic mucus. The enzyme-linked immunosorbent assay （ELISA） was employed to measure the level of VIP in the serum. The mRNA level of AQP in the colon was measured by polymerase chain reaction （Real-time PCR）. Immunohistochemical staining was performed to observe the expression of AQPs in the colon and kidney tissues. Western blot was performed to determine the protein levels of cAMP， PKA， and VIP in the colon tissue. ResultCompared with the control group, the model group had longer time to the first black stool defecation, reduced fecal pellets and water content, reduced Bristol Stool Form Scale score and intestinal propulsion rate, and constipation aggravated（P<0.01）. Moreover, increased the intestinal lesions, reduced the mucus secretion, reduce the serum VIP level, up-regulated the expression levels of AQP1 in the colon and kidney tissues, inhibited the expression of AQP3 and AQP9（P<0.01）., and down-regulated the protein levels of cAMP, PKA, and VIP in the colon tissue. Compared with the model group， the high-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex group had shortened time to the first black stool defecation， increased fecal pellets and water content， increased Bristol Stool Form Scale score and intestinal propulsion rate， and alleviated constipation symptoms. Moreover， high-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex reduced the intestinal lesions， increased the mucus secretion， elevated the serum VIP level（P<0.01）.， down-regulated the expression levels of AQP1 in the colon and kidney tissues， promoted the expression of AQP3 and AQP9（P<0.05，P<0.01）， and up-regulated the protein levels of cAMP， PKA， and VIP in the colon tissue. The medium- and low-dose groups had weaker effect than the high-dose group（P<0.01）. ConclusionHigh-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex can improve the intestinal motility and balance the intestinal water and fluid metabolism by up-regulating the VIP/cAMP/PKA/AQP pathway， thereby mitigating the constipation symptoms in the rat model of slow transit constipation due to yang deficiency.

Analgesic effect of α-cobratoxin on mice and its effect on protein kinase A activity of spinal dorsal root ganglion in mice / 中华行为医学与脑科学杂志

Objective:To study the analgesic effect of α-cobratoxin (α-CbTX) on mice and its effect on protein kinase A (PKA) activity of spinal dorsal root ganglion (DRG) in mice.Methods:Healthy male ICR mice( n=102) were randomly divided into low-, medium-, and high-dose α-CbTX groups (1 mg/kg, 3 mg/kg, 9 mg/kg respectively, gavage, n=21), solvent control group (equivalent volume of 0.9% normal saline, gavage, n=21), morphine positive control group (3 mg/kg, intraperitoneal injection, n=6)or aspirin positive control group(300 mg/kg, gavage, n=12). The analgesic effect of α-CbTX was evaluated by hot plate test, acetic acid twisting test and formalin foot licking test. Formalin plantar injection was used to induce pain and then the L4-L6 DRG was taken 30 minutes later. The expression of PKA C-α in L4-L6 DRG of mice were detected by Western blot.SPSS 16.0 software was used for statistical analysis. Repeated measurement ANOVA was used to evaluate the hot plate experimental data, and one-way ANOVA was used for other experimental data. LSD- t test was used for further pairwise comparison. Results:In the hot plate test, the interaction between group and time of mice paw licking latency was significant ( F=8.902, P<0.05). At 0.5 h after administration, the paw licking latencies of α-CbTX medium-dose group ((11.83±1.47)s)and α-CbTX high-dose group (( 14.33±12.1)s) were both longer than that of solvent control group((8.17±0.75) s) ( t=4.461, 7.053, both P<0.05). The efficacy of α-CbTX medium dose group lasted until 1.5 h after administration (all P<0.05), and that of α-CbTX high dose group lasted until 2 h after administration(all P<0.05). In the acetic acid writhing test, the writhing times in the low-, medium- and high-dose α-CbTX group((34.50±3.62) times, (26.17±2.40) times, (13.83±3.76) times)) were significantly lower than that in solvent control group ((42.50±4.59) times) ( t=3.938, 8.040, 14.112, all P<0.05). In the period of the formalin test phase Ⅱ, the total licking time of α-CbTX low-, medium- and high-dose groups ((71.17±6.46) s), (54.67±6.41) s, (40.50±3.89)s) were significantly shorter than that of the solvent control group ((98.67±11.50) s)( t=6.950, 11.120, 14.700, all P<0.05). In the Western blot experiment, compared with solvent control group (0.22±0.01), the levels of PKA C-α in the DRG of mice in low-, medium- and high-dose α-CbTX groups ((0.31±0.02), (0.41±0.03), (0.44±0.02)) were up-regulated ( t=3.140, 6.471, 7.492, all P<0.05). Conclusion:α-CbTX has obvious analgesic effect, and its analgesic mechanism may be related to the activation of PKA.

Mechanism of Combined Therapy of Lung and Intestine in Alleviating Pulmonary Edema in Treatment of Acute Lung Injury Based on VIP/cAMP/PKA/AQPs Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of the combined therapy of lung and intestine （Mahuangtang + Da Chengqitang） in alleviating pulmonary edema in rats with acute lung injury （ALI） induced by lipopolysaccharide （LPS）. MethodWistar rats were randomly divided into blank group， model group， low-， medium-， and high-dose groups with combined therapy of lung and intestine， and positive control group. LPS （10 mg·kg-1） was given （ip） to induce ALI in rats. After modeling， the blank group was given normal saline （25 mL·kg-1）， the combined therapy of lung and intestine treatment groups were given （ig） low- （5 g·kg-1）， medium- （7.5 g·kg-1）， and high-dose （10 g·kg-1） Mahuangtang and Da Chengqitang， and the positive control group was given dexamethasone （5 mg·kg-1）. Medications were administered 0， 8， and 16 h after LPS injection for 3 times. Then lung tissue and serum were collected after administration. The lung tissues were stained with haematoxylin-eosin （HE）， and the pulmonary edema score was evaluated. The dry/wet （D/W） weight ratio of lung tissues in each group was measured， and the content of serum vasoactive intestinal peptide （VIP） in rats was detected by enzyme-linked immunosorbent assay （ELISA）. Western blot was used to detect the protein levels of aquaporin-1 （AQP1）， AQP5， VIP， cyclic adenosine monophosphate （cAMP）， phosphorylated protein kinase A （p-PKA）， and PKA in lung tissues of rats in each group. The level of VIP mRNA in lung tissues of rats was detected by real-time quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the blank group， the model group exhibited obvious lung injury， increased edema score， decreased D/W ratio （P<0.01）， declined AQP1， AQP5， cAMP， and p-PKA/PKA in lung tissues （P<0.05， P<0.01）， elevated VIP content （P<0.01）， and up-regulated levels of VIP protein and mRNA in lung tissues （P<0.05， P<0.01）. Compared with the model group， combined therapy of lung and intestine treatment groups showed alleviated lung injury， increased D/W ratio （P<0.01）， elevated AQP1， AQP5， VIP， cAMP， and p-PKA/PKA in lung tissues （P<0.05， P<0.01）， and up-regulated VIP levels in lung tissues （P<0.05， P<0.01）. ConclusionThe combined therapy of lung and intestine can alleviate ALI-induced lung tissue edema， and the mechanism may be related to the activation of the VIP/cAMP/PKA signaling pathway， which further promotes the expression of AQP1 and AQP5 and enhances the water metabolism of lung tissue.

Clinical trial of alprostadil combined with metformin in the treatment of diabetic nephropathy / 国际生物医学工程杂志

Objective:To investigate the effect of alprostadil combined with metformin in the treatment of diabetic nephropathy.Methods:50 cases of diabetic nephropathy patients were enrolled and then divided equally into the observation group and the control group. The patients in the control group were treated with conventional therapy and metformin, and the patients in the observation group were treated with alprostadil on the basis of the treatment of the control group. Compare the glycemic index, lipid index, renal function index, inflammatory response index, and oxidative stress response index of the two groups of patients before and after the 4-week treatment. The ratio of the number of effective cases (significant + effective) to the total number of cases, i.e., the total effective rate, was used to characterize the treatment effect.Results:The total effective rate in the observation group was higher than that in the control group (88.00% vs. 60.00%, P<0.05). After the 4-week treatment, no adverse effects occurred in either group. Compared with the control group, patients in the observation group had higher fasting blood glucose (FBG), glycosylated hemoglobin(HbA1c), mean blood glucose(MBG), blood glucose fluctuation rate(BGFR), standard deviation of blood glucose(SDBG), triglyceride(TC), total cholesterol(TG), high-density lipoprotein(HDL), low-density lipoprotein(LDL), serum creatinine(Scr), urinary microalbumin(UmALB), glomerular filtration rate(eGFR), albumin/creatinine ratio(ACR), cyclic adenosine monophosphate(cAMP), renin, protein kinase(PKA), epinephrine (E), angiotensin-converting enzyme inhibitor Ⅱ(ACEI Ⅱ), and norepinephrine(NE) were improved(all P<0.05). Conclusions:The effect of alprostadil combined with metformin in the treatment of diabetic nephropathy is accurate, safe, and reliable.

The role of TSH-THSR-cAMP-PKA signal pathway in the process of iodine uptake in lactating rat mammary gland / 中华地方病学杂志

Objective:To observe the mRNA and protein expression levels of thyroid stimulating hormone receptor (TSHR), protein kinase A (PKA) and sodium iodine transporter (NIS) in mammary gland tissue of lactating rats with different iodine nutrition levels, and to explore the role of thyroid stimulating hormone (TSH)-THSR-cyclic adenosine monophosphate (cAMP)-PKA signal pathway in the process of mammary iodine uptake during lactation.Methods:Using a group design, according to body weight (80 - 100 g), 110 Wistar female rats were randomly divided into normal iodine (NI) group, severe iodine deficiency (SID) group, moderately iodine deficiency (MID) group, moderately iodine excess (MIE) group and severe iodine excess (SIE) group, with 22 rats in each group. Another 22 Wistar male rats were selected, and the feeding situation was consistent with that of NI group. After 3 months of feeding, 24-hour urine samples of female rats were collected, and the female rats were caged with the male rats (5 ∶ 1). After mating, each female rat was fed separately. At 10 days of childbirth, the lactating rats were sacrificed and thyroid and mammary gland tissues were taken. The urinary iodine was determined by arsenic cerium catalytic spectrophotometry. The morphological changes of thyroid and mammary gland tissues were observed by HE staining. The mRNA expression levels of TSHR, PKA and NIS in thyroid and mammary gland tissues were measured by real-time PCR; the protein expression levels of TSHR, PKA, phosphorylated PKA (p-PKA), and NIS in mammary gland tissue were measured by Western blotting.Results:Compared with NI group (162.59 μg/L), the median urinary iodine of female rats in SID and MID groups (3.16, 6.36 μg/L) was lower, and the median urinary iodine of female rats in MIE and SIE groups (2 356.27, 11 507.29 μg/L) was higher ( P < 0.01). HE staining showed that different levels of iodine uptake had different effects on thyroid follicles: most of the follicles in NI group were uniform round or oval; in MID group, the number of small follicles increased, the epithelial cells were monolayer columnar or cubic, the follicular cavity became smaller, and the glia decreased; the follicles in SID group became smaller, and the epithelial cells were columnar or high columnar, with reduced or absent glia in the follicular cavity; pleomorphic changes were found in thyroid follicles in SIE and MIE groups, with some follicles significantly enlarged and some small follicles hyperplasia. Different levels of iodine intake had different effects on mammary duct: compared with NI group, the connective tissue around the mammary duct in SID and MID groups showed obvious fibrosis, while the fibrosis in MIE and SIE groups was significantly reduced. The results of real-time PCR showed that there were significant differences in the mRNA expression levels of TSHR, PKA and NIS in thyroid tissues of lactating rats with different levels of iodine nutrition ( F = 10.73, 92.37, 115.75, P < 0.01). There were statistically differences in the mRNA expression levels of TSHR, PKA and NIS in mammary gland tissues of lactating rats with different levels of iodine nutrition ( F = 40.25, 39.63, 14.92, P < 0.05). Western blotting results showed that there were significant differences in the protein expression levels of TSHR, PKA, p-PKA and NIS in mammary gland tissues of lactating rats with different levels of iodine nutrition ( F = 4.14, 6.73, 8.48, 4.51, P < 0.05). Among them, the protein expression level of TSHR in MIE and SIE groups was lower than that in NI group ( P < 0.05); the protein expression level of PKA in SID and MID groups was higher than that in NI group ( P < 0.05); the protein expression level of p-PKA in SID group was higher than that in NI group, but that in SIE group was lower than that in NI group ( P < 0.05), the protein expression level of NIS in SID group was higher than that in NI group ( P < 0.05). Conclusions:The mRNA and protein expression levels of TSHR are decreased in mammary gland tissues of lactating rats with high iodine intake, while the mRNA and protein expression levels of PKA and NIS are increased in low iodine intake. TSH-TSHR-cAMP-PKA signal pathway may be involved in the regulation of iodine intake in mammary gland tissue of lactating rats, which may protect itself and its offspring.

Research progress in regulating cAMP pathway to prevent and treat chronic obstructive pulmonary disease / 中国药理学通报

Cyclic adenosine monophosphate(cAMP)is a “second messenger” that regulates cell signal transduction. Adenylyl cyclases(ACs)and phosphodiesterases(PDEs)can directly regulate cAMP level in cells and then regulate the downstream signaling pathways. Increasing intracellular cAMP level can inhibit inflammation and enhance smooth muscle relaxation, which is an effective strategy for the prevention and treatment of chronic obstructive pulmonary disease(COPD). This paper briefly summarizes the signaling pathways regulating cAMP and their mechanisms and related drugs in COPD therapy, hoping to provide references for further research and development of new target drugs which regulate cAMP for the prevention and treatment of COPD.

Effect of the aqueous extracts of ganoderma leucocontextum on cognitive function of aging rats / 解剖学报

Objective To investigate the effects of the aqueous extracts of ganoderma leucocontextum (GLAE) on cognitive decline of aging rats and possible regulation mechanism. Methods Fifty rats were divided into five groups, control group, model group, GLAE low-dose group, GLAE middle-dose group and GLAE high-dose group. Aging SD rat models were made by D-galactose, and then treated continuously with different doses (0, 50, 100, 200 mg/ kg) of GLAE. The novel object recognition and step down test were performed to detect the changes of rats cognitive function. The brain tissue was stained with toluidine blue, Giemsa and HE staining and observed. The cerebral cell DNA damage was detected by comet assay. Expressions of protein kinase A (PKA) / cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB) signaling pathway related factors in brain were respectively detected by ELISA, Western blotting and Real-time PCR. Results Compared with the model group, administration of GLAE could obviously alleviate rats cognitive decline and pathological change. The levels of cell DNA damage reduced markedly (P<0. 05). The contents of cAMP, brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF), and also expression levels of mRNA and protein of PKA, BDNF, NGF, CREB in the brain increased significantly in each medicated group (P<0. 01, P< 0. 05). Conclusion GLAE can improve cognitive function, and its mechanism may be related to activation of brain PKA/ CREB signaling pathway, increase in neurotrophic factor content and inhibition of cell DNA damage.

Effect of Electroacupuncture on Content of Cyclic Adenosine Monophosphate and Protein Kinase A, and Phosphorylation of Myosin Light Chain Kinase in Detrusor of Rats with Detrusor Hyperreflex after Suprasacral Spinal Cord Injury / 中国康复理论与实践

Objective:To explore the possible mechanism of electroacupuncture to improve detrusor hyperreflex after suprasacral spinal cord injury. Methods:A total of 60 female Sprague-Dawley rats were included. According to the random number table, twelve were selected as the blank group, twelve as the sham operation group, and the remaining 36 were made neurogenic bladder models using modified T10 spinal cord transection. After that, twelve of them were randomly selected as the model group and twelve were as the electroacupuncture group from the model rats that met the requirements. On the 19th day after modelling, Ciliao (BL32), Zhongji (RN3) and Sanyinjiao (SP6) were taken for electroacupuncture. After seven days of continuous treatment, urodynamic testing was performed, content of cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) in detrusor was determined by ELISA, and the level of phosphorylation of myosin light chain kinase (p-MLCK) of detrusor was determined by Western blotting. Results:Compared with the blank group and the sham operation group, the maximum bladder capacity and bladder compliance significantly reduced (P < 0.01), and the base pressure and leakage point pressure of bladder significantly increased (P < 0.01); the content of cAMP and PKA in detrusor reduced (P < 0.01), p-MLCK in detrusor reduced (P < 0.05) in the model group. Compared with the model group, the maximum bladder capacity and bladder compliance increased (P < 0.01), the base pressure of the bladder and the pressure at the leak point decreased (P < 0.05); the contents of cAMP and PKA protein in detrusor increased (P < 0.05), the p-MLCK in detrusor increased (P < 0.05) in the electroacupuncture group. Conclusion:Electroacupuncture at Ciliao, Zhongji and Sanyinjiao points could improve the bladder function of rats with detrusor hyperreflex after complete spinal cord injury, and its mechanism may be related to up-regulating the expression of cAMP and PKA, phosphorylating and inactivating p-MLCK, which promote relaxation of detrusor.

Effect of Jianpi Bufei Prescription on cAMP/PKA/CREB Signaling Pathway in Juvenile Asthma Rats / 中国实验方剂学杂志

Objective:To investigate the effect of Jianpi Bufei prescription （JPBFP） on airway inflammation， airway hyperresponsiveness （AHR）， and cyclic adenosine monophosphate （cAMP） signaling pathway activity in ovalbumin （OVA）-sensitized and challenged juvenile asthma rats. Method:Seventy-five male SD rats were randomly divided into a blank group （<italic>n</italic>=15） and an experimental group （<italic>n</italic>=60）. The rats in the experimental group were sensitized by aluminum hydroxide gel containing 0.2% OVA and stimulated by aerosol inhalation of normal saline containing 1% OVA to induce an asthma model， followed by assignment into the following groups： a model group （<italic>n</italic>=15）， a JPBFP group （<italic>n</italic>=15， 8.37 g·kg^-1·d^-1）， an aminophylline group （<italic>n</italic>=15， 40 mg·kg^-1·d^-1）， and a dexamethasone group （<italic>n</italic>=15， 0.1 mg·kg^-1·d^-1）. AHR was detected by the pulmonary function analyzer， changes in inflammatory cells by white blood cell （WBC） count and differential blood count in bronchoalveolar lavage fluid （BALF）， and pathological changes of lung tissues by hematoxylin-eosin （HE）， Masson， and periodic acid-schiff （PAS） staining. The interleukin （IL）-4， IL-5， IL-13， interferon （IFN）-<italic>γ</italic>， and tumor necrosis factor （TNF）-<italic>α</italic> levels in serum and the cAMP level in plasma were tested by the enzyme-linked immunosorbent assay （ELISA）. Protein kinase A （PKA） expression in lung tissues was detected by immunohistochemistry. The cAMP-response element-binding protein （CREB） mRNA and protein expression in lung tissues was detected by the real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. Result:Compared with the blank group， the model group showed increased lung resistance， decreased pulmonary compliance （<italic>P</italic><0.05）， elevated WBC count and proportion of eosinophils in BALF （<italic>P</italic><0.05）， up-regulated levels of IL-4， IL-5， IL-13， and TNF-<italic>α</italic> in peripheral blood， declining IFN-<italic>γ</italic> level （<italic>P</italic><0.01）， severe pathological changes of lung tissues， dwindled cAMP， and down-regulated PKA and CREB expression （<italic>P</italic><0.01）. Compared with the model group， JPBFP inhibited AHR， reduced WBC count and proportion of eosinophils in BALF and lung resistance （<italic>P</italic><0.05）， improved pathological changes of lung tissues， increased pulmonary compliance， and up-regulated cAMP in serum and PKA and CREB expression in lung tissues （<italic>P</italic><0.01）. Conclusion:JPBFP can improve AHR， inhibit airway inflammation， and alleviate lung injury in asthma rats. Its mechanism may be related to the up-regulation of the activity of the cAMP/PKA/CREB signaling pathway.

Pathogenic role leukotriene B4 in lung injury induced by lung-protective mechanical ventilation in rabbits / 南方医科大学学报

OBJECTIVE@#To elucidate the pathogenic role of leukotriene B4 (LTB4) in pulmonary hyper-permeability and inflammation induced by lung-protective mechanical ventilation (LPMV) in rabbits.@*METHODS@#Thirty-two healthy Japanese white rabbits were randomized into 4 groups for treatment with vehicle or bestatin (a leukotriene A4 hydrolase inhibitor that inhibits LTB4 production) administered intragastrically at the daily dose of 8 mg/kg for 5 days, followed by sham operation (group S and group BS, respectively, in which the rabbits were anesthetized only) or LPMV (group PM and group BPM, respectively, in which the rabbits received ventilation with 50% oxygen at a tidal volume of 8 mL/kg for 5 h). The concentrations of LTB4 and cyclic adenosine monophosphate (cAMP) in the lung tissues were analyzed by ELISA. cAMP content, protein kinase A (PKA) protein expression and the Rap1-GTP protein to total Rap1 protein ratio were determined to assess the activities of cAMP/PKA and Rap1 signaling pathways. The lung injury was evaluated by assessing lung permeability index, lung wet/dry weight ratio, polymorphonuclear leukocyte (PMN) count in bronchoalveolar lavage fluid (BALF), pulmonary myeloperoxidase (MPO) activity and lung histological scores.@*RESULTS@#None of the examined parameters differed significantly between group S and group BS. All the parameters with the exception of lung histological score increased significantly in group PM and group BPM as compared to those in group S (@*CONCLUSIONS@#LPMV can induce LTB4 overproduction to down-regulate cAMP/PKA and Rap1 signaling pathways in the lungs of rabbits, which results in lung hyper-permeability and inflammation. Bestatin can inhibit LTB4 production in the lungs to protect against LPMV-induced lung hyper-permeability and inflammation.

Taurochenodeoxycholic acid mediates cAMP-PKA-CREB signaling pathway / 中国天然药物

Taurochenodeoxycholic acid (TCDCA) is one of the main effective components of bile acid, playing critical roles in apoptosis and immune responses through the TGR5 receptor. In this study, we reveal the interaction between TCDCA and TGR5 receptor in TGR5-knockdown H1299 cells and the regulation of inflammation via the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA)-cAMP response element binding (CREB) signal pathway in NR8383 macrophages. In TGR5-knockdown H1299 cells, TCDCA significantly activated cAMP level via TGR5 receptor, indicating TCDCA can bind to TGR5; in NR8383 macrophages TCDCA increased cAMP content compared to treatment with the adenylate cyclase (AC) inhibitor SQ22536. Moreover, activated cAMP can significantly enhance gene expression and protein levels of its downstream proteins PKA and CREB compared with groups of inhibitors. Additionally, TCDCA decreased tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, IL-8 and IL-12 through nuclear factor kappa light chain enhancer of activated B cells (NF-κB) activity. PKA and CREB are primary regulators of anti-inflammatory and immune response. Our results thus demonstrate TCDCA plays an essential anti-inflammatory role via the signaling pathway of cAMP-PKA-CREB induced by TGR5 receptor.