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.

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.

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.

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.

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.

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.

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.

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.

Advances in research of protein kinase A in parasites: a review / 中国血吸虫病防治杂志

Protein kinase A (PKA) is an important intracellular substance that regulates substance metabolism and biological functions, which exerts a wide range of biological effects through phosphorylation of specific serine/threonine residues in specific proteins. PKA plays an important role in the cAMP signaling pathway, and is involved in various life activities of parasites. Therefore, investigating the role of PKA in the life activities of parasites may provide insights into the development of novel anti-parasitic targets. The review mainly describes the structure and function of PKA and its role in life activities of parasites.

Effect of Tongbiantang on PKA/MPKA Signal Pathway in Colon Tissue of STC Rat Model / 中国实验方剂学杂志

Objective: To explore the effect of Tongbiantang on protein kinase A(PKA) and mitogen-activated protein kinase(MAPK) signal pathway in colon tissue of slow transit constipation(STC) rats and its related mechanism. Method: Eighty SD rats were randomly divided into blank group and model group, 20 rats in blank group, 60 rats in model group, half male and half female; blank group was fed with common diet, model group was fed with compound phenylethylpiperidine, after 120 days of modeling, 10 rats in blank group and 20 rats in model group were randomly selected, and 2 rats were determined. Four-hour stool volume, water content and small intestinal charcoal powder propelling rate were observed to observe the number of stool particles retained in colon and evaluate the success of STC rat modeling. After 1 week of drug withdrawal, 40 rats in model group were randomly divided into model group(33 g·kg-1), Tongbiantang group, Tongbiantang+H89 group (PKA signaling pathway blocker,5 mg·kg-1), Tongbiantang+U0126 group (MPKA signaling pathway blocker,0.1 mg·kg-1) each. After 4 weeks of intervention with Tongbiantang, the amount of stool excretion, water content and small intestinal charcoal powder propelling rate were measured in 10 rats, and the number of stool grains in colon was observed. The protein content and mRNA expression in aquaporins 3(AQP3), AQP4, PKA and MAPKs signaling pathways in colon was determined by immunohistochemical staining (IHC), Western blot and Real-time fluorescence quantitative PCR (Real-time PCR). Result: Compared with the blank group, the 24-hour stool volume, fecal water content, small intestinal charcoal propelling rate and the number of fecal particles in colon of rats in the model group were significantly decreased (PPPPPConclusion: Tongbiantang can inhibit the PKA and MPKA signal pathways, thus down-regulate the expression of AQP3 and AQP4, increase intestinal peristalsis and intestinal water, and effectively treat STC.

Protein kinase A inhibition induces EPAC-dependent acrosomal exocytosis in human sperm / 亚洲男科学杂志(英文版)

To interact with the egg, the spermatozoon must undergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosomal exocytosis, near or on the egg, a process that allows the sperm to penetrate and fertilize the egg. In the present study, we investigated the involvement of cyclic adenosine monophosphate (cAMP)-dependent processes on acrosomal exocytosis. Inhibition of protein kinase A (PKA) at the end of capacitation induced acrosomal exocytosis. This process is cAMP-dependent; however, the addition of relatively high concentration of the membrane-permeable 8-bromo-cAMP (8Br-cAMP, 0.1 mmol l-1) analog induced significant inhibition of the acrosomal exocytosis. The induction of acrosomal exocytosis by PKA inhibition was significantly inhibited by an exchange protein directly activated by cAMP (EPAC) ESI09 inhibitor. The EPAC selective substrate activated AE at relatively low concentrations (0.02-0.1 μmol l-1), whereas higher concentrations (>5 μmol l-1) were inhibitory to the AE induced by PKA inhibition. Inhibition of PKA revealed about 50% increase in intracellular cAMP levels, conditions under which EPAC can be activated to induce the AE. Induction of AE by activating the actin severing-protein, gelsolin, which causes F-actin dispersion, was inhibited by the EPAC inhibitor. The AE induced by PKA inhibition was mediated by phospholipase C activity but not by the Ca2+-channel, CatSper. Thus, inhibition of PKA at the end of the capacitation process induced EPAC/phospholipase C-dependent acrosomal exocytosis. EPAC mediates F-actin depolymerization and/or activation of effectors downstream to F-actin breakdown that lead to acrosomal exocytosis.

Effect of endostatin overexpression on angiotensin II-induced cardiac hypertrophy in rats / 中华医学杂志(英文版)

Background@#Endostatin, a biologically active fragment of collagen XVIII, has been observed in patients with ischemic heart disease. The aim of the present study was to investigate whether endostatin overexpression could attenuate cardiac hypertrophy by inhibiting the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) signaling pathway.@*Methods@#This study was examined in vivo in rats and in vitro in primary neonatal rat cardiomyocytes treated with angiotensin (Ang) II to model cardiac hypertrophy. Twenty-four male Sprague-Dawley rats were randomized into adenovirus (Ad)-green fluorescent protein, Ang II, Ad-endostatin, and Ang II + Ad-endostatin groups (n = 6 in each group). Four weeks later, all the rats were weighed and sacrificed after transthoracic echocardiography. Cardiac function was evaluated by transthoracic echocardiography, cardiomyocyte size was evaluated by hematoxylin-eosin staining. Levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were evaluated by quantitative reverse-transcription polymerase chain reaction or Western blotting, PKA level was evaluated by Western blotting, and cAMP level was evaluated by enzyme-linked immunosorbent assay. Statistical significance among multiple groups was evaluated by one-way analysis of variance.@*Results@#Endostatin overexpression reduced the increases in left ventricle (LV) mass (P = 0.0063), LV mass/body weight (BW) (P = 0.0013), interventricular septal thickness (IVS) in diastole (P = 0.0013), IVS in systole (P = 0.0056), left ventricular posterior wall thickness (LVPW) in diastole (P = 0.0291), LVPW in systole (P = 0.0080), heart weight (HW) (P = 0.0138), HW/BW (P = 0.0001), and HW/tibial length (P = 0.0372) in Ang II-treated rats. In addition, endostatin overexpression reduced cardiomyocyte cross-sectional area expansion, and reduced the levels of ANP and BNP in Ang II-treated rats (P = 0.0251 and 0.0477 for messenger RNA [mRNA]), and primary neonatal rat cardiomyocytes (P = 0.0188 and P = 0.0024 for mRNA; P = 0.0023 and 0.0013 for protein, respectively). Additionally, endostatin overexpression reduced the increase of cAMP (P = 0.0054) and PKA (P = 0.0328) levels in cardiomyocytes treated with Ang II. Treatment with cAMP reversed the effects of endostatin overexpression on ANP (P = 0.0263) and BNP (P = 0.0322) levels in cardiomyocytes induced by Ang II.@*Conclusion@#Endostatin overexpression could alleviate cardiac hypertrophy by inhibiting the cAMP-PKA signaling pathway.

High frequency repeated transcranial magnetic stimulation improves learning and memory of global cerebral ischemia rats and its mechanism / 中华神经科杂志

Objective To study the effect of high frequency repeated transcranial magnetic stimulation (rTMS) on learning and memory in rats with global cerebral ischemia and to investigate its mechanism.Methods Thirty-five male Sprague-Dawley rats (8-10 weeks old) were randomly divided into sham operation group (n=8),model group (n=9),sham-rTMS (s-rTMS) group (n=9) and rTMS group (n=9).The global cerebral ischemia model was established by modified four-vessel occlusion method.The rTMS group received 10 Hz rTMS stimulation for two weeks,whereas the s-rTMS group received sham stimulation.Morris water maze test was used to detect the spatial learning ability,multi-channel recording technique was used to detect the local field potentials in the hippocampus CA1 region of theta and gamma oscillation,and immunohistochemical staining and Western blotting were used to detect the expression of protein kinase A (PKA) and phosphorylated cyclic adenosine monophosphate response element binding protein (p-CREB) of hippocampus.Results The average escape latency in the model group was longer than that in the sham operation group ((35.16±0.80) s vs (16.57±0.74) s,k=3.723,P=0.013),the spanning platform times and the original platform quadrant swimming time in the model group were shorter than that in the sham operation group (1.14±0.42 vs 4.46±0.23,k=3.185,P=0.042;(14.46±0.73) s vs (29.31±0.42) s,k=3.027,P=0.047).Compared with the sham operation group,the mean power spectral density of theta and gamma reduced ((-68.48±2.61) Hz vs (-59.38±2.25) Hz,k=2.958,P=0.048;(-82.23±4.60) Hz vs (-70.50±4.25) Hz,k=3.729,P=0.021),and the expression of PKA and p-CREB protein decreased in the model group (7 184.26±975.12 vs 25 137.35±1 010.62,k=3.588,P=0.027;1 803.73±336.18 vs 20 175.25±727.23,k=2.912,P=0.049).The average escape latency in the rTMS group was shorter than that in the model group ((24.69± 1.01) s vs (35.16±0.80) s,k=4.082,P=0.034),and the spanning platform times and the original platform quadrant swimming time in the rTMS group was longer than that in the model group (2.42±0.31 vs 1.14±0.42,k=3.296,P=0.039;(23.07±0.67) s vs (14.46±0.73) s,k=4.323,P=0.012).Compared with the rTMS group,the power spectral density of theta and gamma reduced ((-63.81±3.12) Hz vs (-68.48±2.61) Hz,k=3.582,P=0.015;(-75.80±4.58) Hz vs (-82.23±4.60) Hz,k=4.051,P=0.026),and the expression of PKA and p-CREB protein decreased in the model group (13 065.32±1 045.18 vs 7 184.26±975.12,k=3.923,P=0.031;11 032.83±562.86 vs 18 03.73±336.18,k=3.178,P=0.038).Conclusion High frequency rTMS could improve learning and memory of global cerebral ischemia rats,the mechanism of which might be that rTMS enhance the hippocampal theta and gamma oscillations and increase the expression of PKA and p-CREB protein in the hippocampus,thus increasing the hippocampus synaptic plasticity.

2-Chloroethanol enhanced the expression of AQP4 protein in astrocytes via NMDAR/cAMP/PKA signaling pathway / 中国职业医学

OBJECTIVE: To investigate the role of N-methyl-D-aspartate receptor(NMDAR)/cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA) signaling pathways in regulating 2-chloroethanol-induced aquaporin-4(AQP4) expression in astrocytes(AS). METHODS: i) AS in logarithmic growth phase were treated with 2-chloroethanol at the doses of 0.0, 7.5, 15.0 and 30.0 mmol/L for 12 hours, and the cells were collected for detection. ii) The AS in logarithmic growth phase were divided into blank control group, inhibitor control group, 2-chloroethanol group, and inhibitor intervention group. The inhibitor included dizocilpine(MK-801) and N-(2-[p-bromocinnamylamino-]ethyl)-5-isoquinolinesulfonamide(H89). The blank control group did not receive any treatment. The inhibitor control group was treated with a concentration of 10.0 μmmol/L MK-801 or 15.0 μmmol/L H89. The MK-801 intervention group was pretreated with MK-801 at a concentration of 10.0 μmmol/L for 30 minutes. The H89 intervention group was pretreated with H89 at a concentration of 15.0 μmmol/L for 1 hour. After the intervention, the AS in 2-chloroethanol group and MK-801, H89 intervention group were stimulated with 2-chloroethanol at a dose of 30.0 mmol/L for 12 hours. iii) The AS in each group were collected and used for Western blotting and real-time fluorescence quantitative polymerase chain reaction analysis to detect the protein and mRNA expression of AQP4, NMDAR receptor main subunit(NR1), NMDAR receptor 2 B subunit(NR2 B) and calmodulin dependent protein kinaseⅡ(CaMKⅡ). The Western blotting was adopted to detect the expression of phosphorylase-CaMKⅡ(p-CaMKⅡ) and PKA. Colorimetric method was used to detect the concentration of calcium(Ca~(2+)) in AS. The enzyme-linked adsorption test was used to measure adenylate cyclase(AC) activity and cAMP levels. RESULTS: i) The relative expression of protein and mRNA of AQP4, NR1 and NR2 B, PKA at protein level and CaMKⅡ at mRNA level, and the ratio of p-CaMKⅡ/CaMKⅡ protein, the concentration of Ca~(2+), AC activity and cAMP level in 30.0 mmol/L group were higher then those of 0.0 mmol/L group in AS(P<0.05). The relative protein expression of PKA and the concentration of Ca~(2+) increased with the increase of 2-chloroethanol(P<0.05). ii) The relative protein expression of AQP4 and the concentration of Ca~(2+) in the 2-chloroethanol group were higher than that of the blank control group and MK-801 control group(P<0.05). The relative protein expression of AQP4 and the concentration of Ca~(2+) in MK-801 intervention group were lower than that in 2-chloroethanol group(P<0.05). The relative protein expression of AQP4 and PKA in 2-chloroethanol group were higher than that of the blank control group and H89 control group(P<0.05). The relative protein expression of AQP4 and PKA in H89 intervention group was lower than that in 2-chloroethanol group(P<0.05). CONCLUSION: The 2-chloroethanol timulation induces the expression of AQP4 by activating NMDAR/cAMP/PKA signaling pathway in AS.

Influences of scutellarin on ATP-induced inflammasome activation and pyroptosis in J774A.1 macrophages / 中国药理学通报

Aim To explore the influences of scutellarin on ATP-induced NLRP3 inflammasome activation and pyroptosis,using LPS-primed murine macrophages J774A.1 as an inflammatory cell model,and to explore the underlying mechanism.Methods The effects of scutellarin on ATP-induced pyroptosis in murine J774A.1 macrophages were analyzed by propidium iodide (PI) staining assay.The levels of IL-1β,caspase-1 and HMGB1 in cell lysates and culture supernatants were analysed using Western blot.The levels of IL-1β in cell culture supernatants were measured by cytometric beads array (CBA).Results ATP significantly induced caspase-1 activation and mature IL-1β and HMGB1 release into the culture supernatants in LPS-primed murine J774A.1 macrophages,and induced pyroptosis.Scutellarin treatment dose-dependently inhibited ATP-induced caspase-1 activation,mature IL-1β and HMGB1 release,and pyroptosis.Notably,scutellarin's inhibitory effects on ATP-induced pyroptosis were markedly reversed by the adenylate cyclase inhibitor MDL12330A and selective protein kinase A (PKA) inhibitor H89.Conclusion Scutellarin inhibits NLRP3 inflammasome activation and pyroptosis by modulating the PKA activity in macrophages,thereby exhibiting anti-inflammatory activities.

The role of RyR2 phosphorylation in heart failure / 复旦学报（医学版）

Heart failure is mainly characterized by myocardial systolic dysfunction,which is based on excitement-contraction coupling on the cellular level,and calcium (Ca2+) signaling plays a very important role in this process.The ryanodine receptor (RyR)/calcium release channel on the sarcoplasmic reticulum (SR) is the major Ca2+ source of required for cardiac muscle excitation contraction coupling.RyR2 phosphorylation is the basis of SR calcium release,and RyR2 phosphorylation is mainly controled by protein kinase A (PKA) and calcium/calmodulin dependent protein kinase Ⅱ (CaMK Ⅱ).Although widely research in this area,excessive activation of RyR2 phosphorylation involved in the pathogenesis of heart failure are still controversial,which is discussed in this review.