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.

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.

MF-SuP-pKa: Multi-fidelity modeling with subgraph pooling mechanism for pKa prediction

Acid-base dissociation constant (pKa) is a key physicochemical parameter in chemical science, especially in organic synthesis and drug discovery. Current methodologies for pKa prediction still suffer from limited applicability domain and lack of chemical insight. Here we present MF-SuP-pKa (multi-fidelity modeling with subgraph pooling for pKa prediction), a novel pKa prediction model that utilizes subgraph pooling, multi-fidelity learning and data augmentation. In our model, a knowledge-aware subgraph pooling strategy was designed to capture the local and global environments around the ionization sites for micro-pKa prediction. To overcome the scarcity of accurate pKa data, low-fidelity data (computational pKa) was used to fit the high-fidelity data (experimental pKa) through transfer learning. The final MF-SuP-pKa model was constructed by pre-training on the augmented ChEMBL data set and fine-tuning on the DataWarrior data set. Extensive evaluation on the DataWarrior data set and three benchmark data sets shows that MF-SuP-pKa achieves superior performances to the state-of-the-art pKa prediction models while requires much less high-fidelity training data. Compared with Attentive FP, MF-SuP-pKa achieves 23.83% and 20.12% improvement in terms of mean absolute error (MAE) on the acidic and basic sets, respectively.

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.

Teriparatide regulates osteoblast differentiation in high-glucose microenvironment through the cAMP/PKA/CREB signaling pathway / 南方医科大学学报

OBJECTIVE@#To investigate the effect of teriparatide on the differentiation of MC3T3-E1 cells in high-glucose microenvironment and explore the possible mechanism.@*METHODS@#MC3T3-E1 cells cultured in normal glucose or high-glucose (25 mmol/L) medium were treated with 10 nmol/L teriparatide with or without co-treatment with H-89 (a PKA inhibitor). CCK-8 assay was used to detect the changes in cell proliferation, and cAMP content in the cells was determined with ELISA. Alkaline phosphatase (ALP) activity and mineralized nodules in the cells were detected using ALP kit and Alizarin red staining, respectively. The changes in cell morphology were detected by cytoskeleton staining. Real-time PCR was used to detect the mRNA expressions of PKA, CREB, RUNX2 and Osx in the treated cells.@*RESULTS@#The treatments did not result in significant changes in proliferation of MC3T3-E1 cells (P > 0.05). Compared with the cells in routine culture, the cells treated with teriparatide showed significantly increased cAMP levels (P < 0.05) with enhanced ALP activity and increased area of mineralized nodules (P < 0.05). Teriparatide treatment also resulted in more distinct visualization of the cytoskeleton in the cells and obviously up-regulated the mRNA expressions of PKA, CREB, RUNX2 and Osx (P < 0.05). The opposite changes were observed in cells cultured in high glucose. In cells exposed to high glucose, treatment with teriparatide significantly increased cAMP levels (P < 0.05), ALP activity and the area of mineralized nodules (P < 0.05) and enhanced the clarity of the cytoskeleton and mRNA expressions of PKA, CREB, RUNX2 and Osx; the effects of teriparatide was strongly antagonized by co-treatment with H-89 (P < 0.05).@*CONCLUSION@#Teriparatide can promote osteoblast differentiation of MC3T3-E1 cells in high-glucose microenvironment possibly by activating the cAMP/PKA/CREB signaling pathway.

Antidepressant-like effect of caffeic acid: Involvement of the cellular signaling pathways

Abstract Caffeic acid is a phenolic compound widely distributed in plants and beverages such as coffee. Although its mechanism of action is poorly understood, caffeic acid reportedly induces antidepressant-like and neuroprotective effects. This study aimed to investigate the involvement of cellular signaling pathways in acute antidepressant-like effect induced by caffeic acid in mice. All procedures were approved by the Institutional Animal Ethics Committee of the UNIVALI n. 021/2013. Female Swiss mice were administered with vehicle, caffeic acid (5 mg/ kg, p.o.), inhibitor (H-89, U0126, chelerythrine, or PD9859, i.c.v.) or caffeic acid plus inhibitor. The behavioral effects were evaluated 1h after the administration of compounds to mice using tail suspension test (TST) and open field test (OFT). The results showed that the antidepressant- like effect of caffeic acid in mice was possibly mediated by the activation of PKA, MEK 1/2, PKC and MAPK (as assessed using TST), without compromising their locomotor activity (as assessed using OFT). Our results demonstrated, at least in part, the pathways involved in the neuroprotective and behavioral effects of caffeic acid.

Spectrophotometric determination of acid dissociation constants of some arylpropionic acids and arylacetic acids in acetonitrile-water binary mixtures at 25ºC

Abstract The acid dissociation constant of drug active compounds (arylpropionic and aryl acetic acids) were determined in acetonitrile and water binary mixtures (corresponding volume fractions of 0.40, 0.45, 0.50, and 0.55) by using a multi-wavelength spectrophotometric method. Drug active compounds, which were slightly soluble in water, were studied in these binary mixtures. The dissociation constants of drug active compounds are important in drug design studies and in any research of the biopharmaceutical and physicochemical properties of drugs. The STAR program was used for the determination of dissociation constants. The acidity constants of arylpropionic and aryl acetic acids were correlated with the Kamlet and Taft solvaatochromic parameters. Aqueous pKa values of these arylpropionic and aryl acetic acids were determined from pKa values obtained from acetonitrile and water binary mixtures with varying volume fractions. The studied drugs had a pKa value corresponding to base functional group. Results showed that the acid dissociation constant values of the drug active compounds increased with an increase in acetonitrile content in the medium.

Roles of c-Fos, EGR-1, PKA, and PKC in cognitive dysfunction in rats after propofol anesthesia

Abstract This study aimed to investigate possible changes in the spatial memory of rats and the expression or activity of EGR-1, c-Fos, PKA, and PKC after propofol anesthesia. Thirty-six Sprague-Dawley rats aged 20 months and 36 Sprague-Dawley rats aged three months were each randomly divided into three groups: the control group, the Morris Water Maze (MWM) group, and the propofol group. In the propofol groups of both young and aged rats, the rats were anesthetized by propofol for two or four hours and then performed the MWM test two days or two weeks after anesthesia to assess cognitive function. EGR-1, c-Fos, PKA, and PKC expressions in the rat hippocampus were determined via immunohistochemistry. For the older rats, the escape latency in the P4h/2d group was significantly prolonged (P < 0.05), and the learning curve was right-shifted in the P4h/2w group (P < 0.05). The expression levels of EGR-1, c-Fos, PKA, and PKC in the MWM groups were significantly higher than those in the control groups (P < 0.05). In the P4h/2d group of aged rats, the expression levels of both PKA and PKC were decreased compared with those of the MWM groups. The decreased expression of both protein kinases may be responsible for the observed impairment after propofol anesthesia

Low-frequency pulsed electromagnetic fields promote osteoblast mineralization and maturation of rats through the PC2/sAC/PKA/CREB signaling pathway / 南方医科大学学报

OBJECTIVE@#To explore whether the effect of low-frequency pulsed electromagnetic fields (PEMFs) in promoting osteoblast mineralization and maturation is related to the primary cilia, polycystin2 (PC2) and sAC/PKA/CREB signaling pathway.@*METHODS@#We detected the expression levels of PC2, sAC, PKA, CREB and their phosphorylated proteins in primary rat calvarial osteoblasts exposed to 50 Hz 0.6 mT PEMFs for 0, 5, 15, 30, 60, 90, and 120 min. We blocked PC2 function with amiloride hydrochloride and detected the changes in the activity of sAC/PKA/CREB signal pathway and the mineralization and maturation of the osteoblasts. These examinations were repeated in the osteoblasts after specific knockdown of PC2 via RNA interference and were the co-localization of PC2, sAC, PKA, CREB and their phosphorylated proteins with the primary cilia were using immunofluorescence staining. The expressions of PC2 and the signaling proteins of sAC/PKA/CREB pathway were detected after inhibition of primary ciliation by RNA interference.@*RESULTS@#The expression levels of PC2, sAC, p-PKA and p- CREB were significantly increased in the osteoblasts after exposure to PEMFs for different time lengths (P < 0.01). Blocking PC2 function or PC2 knockdown in the osteoblasts resulted in failure of sAC/PKA/CREB signaling pathway activation and arrest of osteoblast mineralization and maturation. PC2, sAC, p-PKA and p-CREB were localized to the entire primary cilia or its roots, but PKA and CREB were not detected in the primary cilia. After interference of the primary cilia, PEMFs exposure no longer caused increase of PC2 expression and failed to activate the sAC/PKA/CREB signaling pathway or promote osteoblast mineralization and maturation.@*CONCLUSION@#PC2, located on the surface of the primary cilia of osteoblasts, can perceive and transmit the physical signals from PEMFs and promote the mineralization and maturation of osteoblasts by activating the PC2/ sAC/PKA/CREB signaling pathway.

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.

Improvement effects of sinapic acid on Aβ42-induced injury of PC 12 cells and the mechanism / 中国药房

OBJECTIVE To s tudy the improvement effects of sinapic acid on Aβ42-induced injury of PC 12 cells and the mechanism. METHODS PC12 cells were divided into five groups ：control group ，model group ，sinapic acid group ，phosphoinositide- 3-kinase（PI3K）inhibitor group and extracellular signal-regulated kinase （ERK）inhibitor group. Each inhibitor group was added with LY 294002 and U 0126（10 μmol/L）for 1 h；except for control group ，other four groups were treated with 2 μmol/L Aβ42 for 24 h to replicate the Alzheimer ’s disease cell model ；except for control group and model group ，other three groups were added with 100 μmol/L sinapic acid respectively. After 24 hours of continuous culture ，survival rate of PC 12 cells was detected and the morphology of PC 12 cells was observed. The content of Aβ42，mRNA expression of cAMP response element binding protein （CREB），protein expression of cyclic adenosine monophosphate （cAMP），protein kinase A （PKA），CREB signaling pathway and phosphorylated CREB （p-CREB）were detected. RESULTS After treated with sinapic acid ，the survival rate of PC 12 cells，mRNA expression of CREB and protein expressions of cAMP ，PKA and p-CREB were increased significantly （P＜0.05），while the content of Aβ42 was decreased significantly （P＜0.05）；cell morphology was significantly improved and synapses increased. After intervened with PI 3K and ERK inhibitors ，the survival rate of PC 12 cells，above mRNA and protein expressions were reversed significantly （P＜0.05 or P＜0.01）；cell morphology was irregular ，the fragments increased ，and the synaptic connections decreased. CONCLUSIONS Sinapic acid can improve the survival rate of PC 12 cells injured by A β 42，improve cell （No.2021-KYYWF-0349） morphology and decrease the content of Aβ42，the mechanism of which may be associated with promoting the gene transcription of CREB ， and activating cAMP/PKA/CREB signaling pathway.

Optimization of extraction of flavonoids from Lonicera rupicola and analysis of its effects in resisting inflammation, relieving pain, enhancing immunity, and inhibiting pyroptosis / 中国中药杂志

The present study optimized the extraction of flavonoids from Lonicera rupicola Hook. f. et Thoms(LRH) and explored its pharmacological effects, such as resisting inflammation, relieving pain, enhancing immunity, and inhibiting pyroptosis, aiming to provide data support and scientific basis for the development and utilization of LRH. Response surface methodology(RSM) was applied to optimize the extraction of flavonoids from LRH based on the results of single-factor experiments. Anti-inflammatory and analgesic effects of LRH flavonoids were evaluated via inflammation and pain models in mice, such as xylene-induced ear swelling, carrageenan-induced footpad swelling, writhing caused by acetic acid, and paw licking. The effect of LRH flavonoids on the carbon clearance index of monocytes and serum immunoglobulin A(IgA) and IgM levels was analyzed on the immunosuppression model induced by cyclophosphamide in mice. The anti-oxidative effect in vivo of LRH flavonoids on liver superoxide dismutase(SOD), catalase(CAT), and malondialdehyde(MDA) levels was determined based on the chronic/subacute aging model in mice induced by D-galactose. The levels of cysteinyl aspartate specific proteinase-1(caspase-1), interleukin-1β(IL-1β), and IL-18 in the supernatant of J774 A.1 mononuclear phagocytes were detected to evaluate the effect of LRH flavonoids on the pyroptosis of mononuclear phagocytes in mice induced by the combination of lipopolysaccharide(LPS) and adenosine triphosphate(ATP). Meanwhile, the effect of LRH flavonoids on the cAMP-PKA signaling pathway was also explored. The optimum conditions for the extraction of LRH flavonoids are listed below: extraction temperature of 65 ℃, the ethanol concentration of 50%, extraction time of 60 min, a material-liquid ratio at 1∶25, and the yield of LRH flavonoids of 0.553%. RSM determined the multiple quadratic regression equation model of response value and variables as follows: the yield of LRH flavonoids=0.61-0.48A+0.1B+0.029C-0.014D+0.32AB+0.04AC-0.012AD-0.02BC+0.037BD-0.031CD-0.058A~2-0.068B~2-0.069C~2-0.057D~2. LRH flavonoids could effectively inhibit ear swelling and footpad swelling, reduced acetic acid-induced writhing, and delayed the paw licking response time in mice. Additionally, LRH flavonoids could improve the carbon clearance index in immunosuppressed mice, potentiate the activities of SOD and CAT and reduce MDA levels in the liver of aging mice induced by D-galactose, and effectively inhibit macrophage pyroptosis by decreasing the levels of caspase-1, IL-1β, and IL-18. The results reveal that LRH flavonoids possess excellent pharmacological activities such as resisting inflammation and oxidation, relieving pain, and enhancing immunity. They can inhibit pyroptosis by enhancing the cAMP-PKA signaling pathway. The results of this study can underpin the pharmacological research, development, and utilization of LRH.

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 TSG on GSK3β，PKA and PP2A of APP/PS1/Tau Triple-transgenic Mice Dementia Model / 中国实验方剂学杂志

Objective:To observe the effect of tetrahydroxy stilbene glycoside （TSG） on the expression of glycogen synthase kinase 3<italic>β </italic>（GSK3<italic>β</italic>）， cyclic adenosine monophosphate-dependent protein kinase （PKA） and Serine/threonine phosphatase 2A（PP2A） in the brain of amyloid precursor protein/presenilin-1/Tau （APP/PS1/Tau） triple-transgenic mice dementia model. Method:A total of forty-five 8-month-old APP/PS1/Tau transgenic mice were randomly divided into model group， positive control group （Huperzine-A， 0.15 mg·kg^-1）， low， medium and high dose TSG groups （TSG， 0.033，0.1，0.3 g·kg^-1）， with 9 mice in each group， and another nine C5B7L/6J mice of the same age were selected as normal control group. After 60 days of intragastric administration， the general structure of hippocampal neurons was observed by hematoxylin-eosin （HE） staining， immunohistochemical （IHC） was used to detect the expression of PKA protein in the brain of mice in each group， the mRNA expression levels of GSK3<italic>β</italic>， PKA and PP2A were detected by real time quantitative reverse transcription polymerase chain reaction （Real-time PCR）， and protein expression levels of GSK3<italic>β</italic> and PP2A were detected by Western blot. Result:Compared with the normal control group， the apoptosis level of neurons in the model group was significantly increased， the protein and mRNA expression levels of GSK3<italic>β</italic> and PKA were significantly increased （<italic>P</italic><0.05， <italic>P</italic><0.01）， and the protein and mRNA expression levels of PP2A were significantly decreased （<italic>P</italic><0.05， <italic>P</italic><0.01）. Compared with the model group， the apoptosis level of neurons in each treatment group was significantly down-regulated， the protein and mRNA expression levels of GSK3<italic>β</italic> and PKA were significantly down-regulated （<italic>P</italic><0.05， <italic>P</italic><0.01）， and the protein and mRNA expression levels of PP2A were significantly increased （<italic>P</italic><0.05， <italic>P</italic><0.01）. Conclusion:The mechanism of TSG in the treatment of Alzheimer's disease （AD） may be related to lowering the transcription and expression of GSK3<italic>β</italic> and PKA， increasing the transcription and expression of PP2A.

Scutellarin inhibits caspase-11 activation and pyroptosis in macrophages via regulating PKA signaling

@#Inflammatory caspase-11 senses and is activated by intracellular lipopolysaccharide (LPS) leading to pyroptosis that has critical role in defensing against bacterial infection, whereas its excess activation under pathogenic circumstances may cause various inflammatory diseases. However, there are few known drugs that can control caspase-11 activation. We report here that scutellarin, a flavonoid from Erigeron breviscapus, acted as an inhibitor for caspase-11 activation in macrophages. Scutellarin dose-dependently inhibited intracellular LPS-induced release of caspase-11p26 (indicative of caspase-11 activation) and generation of N-terminal fragment of gasdermin D (GSDMD-NT), leading to reduced pyroptosis. It also suppressed the activation of non-canonical nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome as evidenced by reduced apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and decreased interleukin-1 beta (IL-1β) and caspase-1p10 secretion, whereas the NLRP3-specific inhibitor MCC950 only inhibited IL-1β and caspase-1p10 release and ASC speck formation but not pyroptosis. Scutellarin also suppressed LPS-induced caspase-11 activation and pyroptosis in RAW 264.7 cells lacking ASC expression. Moreover, scutellarin treatment increased Ser/Thr phosphorylation of caspase-11 at protein kinase A (PKA)-specific sites, and its inhibitory action on caspase-11 activation was largely abrogated by PKA inhibitor H89 or by adenylyl cyclase inhibitor MDL12330A. Collectively, our data indicate that scutellarin inhibited caspase-11 activation and pyroptosis in macrophages at least partly via regulating the PKA signaling pathway.

Spinal protein kinase A and phosphorylated extracellular signal-regulated kinase signaling are involved in the antinociceptive effect of phytohormone abscisic acid in rats / A proteína quinase A da medula espinhal e a sinalização da quinase fosforilada regulada por sinal extracelular estão envolvidas no efeito antinociceptivo do ácido fito-hormônio abscísico em ratos

Abstract Objective: The phytohormone abscisic acid (ABA) as a signaling molecule exists in various types of organisms from early multicellular to animal cells and tissues. It has been demonstrated that ABA has an antinociceptive effect in rodents. The present study was designed to assess the possible role of PKA and phosphorylated ERK (p-ERK) on the antinociceptive effects of intrathecal (i.t.) ABA in male Wistar rats. Methods: The animals were cannulated intrathecally and divided into different experimental groups (n=6‒7): Control (no surgery), vehicle (received ABA vehicle), ABA-treated groups (received ABA in doses of 10 or 20 µg/rat), ABA plus H.89 (PKA inhibitor)-treated group which received the inhibitor 15 min prior to the ABA injection. Tail-flick and hot-plate tests were used as acute nociceptive stimulators to assess ABA analgesic effects. p-ERK was evaluated in the dorsal portion of the spinal cord using immunoblotting. Results: Data showed that a microinjection of ABA (10 and 20 µg/rat, i.t.) significantly increased the nociceptive threshold in tail flick and hot plate tests. The application of PKA inhibitor (H.89, 100 nM/rat) significantly inhibited ABA-induced analgesic effects. Expression of p-ERK was significantly decreased in ABA-injected animals, which were not observed in the ABA+H.89-treated group. Conclusions: Overall, i.t. administration of ABA (10 µg/rat) induced analgesia and p-ERK down-expression likely by involving the PKA-dependent mechanism.

Resumo Objetivo: O ácido fito-hormônio abscísico (ABA) existe como molécula sinalizadora em vários tipos de organismos, de multicelulares a células e tecidos animais. Foi demonstrado que o ABA tem efeito antinociceptivo em roedores. O presente estudo foi desenhado para avaliar o possível papel da PKA e da ERK fosforilada (p-ERK) nos efeitos antinociceptivos do ABA intratecal (i.t.) em ratos Wistar machos. Métodos: Os animais foram canulados por via i.t. e divididos em diferentes grupos experimentais (n=6‒7): controle (sem cirurgia), veículo (veículo ABA recebido), grupos tratados com ABA (recebeu ABA em doses de 10 ou 20 µg/rato), grupo tratado com ABA mais H.89 (inibidor de PKA) que recebeu o inibidor 15 minutos antes da injeção de ABA. Os testes de movimento da cauda e placa quente foram utilizados como estimuladores nociceptivos agudos para avaliar os efeitos analgésicos da ABA. A p-ERK foi avaliada na porção dorsal da medula espinhal por imunotransferência. Resultados: A microinjeção de ABA (10 e 20 µg/rato, i.t.) aumentou significativamente o limiar nociceptivo nos testes de movimento da cauda e placa quente. A aplicação de inibidor de PKA (H.89, 100 nM/rato) inibiu significativamente os efeitos analgésicos induzidos por ABA. A expressão de p-ERK diminuiu significativamente em animais injetados com ABA que não foram observados no grupo tratado com ABA+H.89. Conclusões: No geral, a administração i.t. de ABA (10 µg/rato) induziu a analgesia e expressão negativa de p-ERK provavelmente envolvendo mecanismo dependente de PKA.

Mechanism of cAMP-PKA Signaling Pathway Mediated by Shaoyao Gancao Decoction () on Regulation of Aquaporin 5 and Muscarinic Receptor 3 Levels in Sjögren's Syndrome / 中国结合医学杂志

OBJECTIVE@#To investigate the mechanism of cAMP-PKA signaling pathway mediated by Chinese medicine formula Shaoyao Gancao Decoction (, SGD) on the regulation of aquaporin 5 (AQP5) and muscarinic receptor 3 (M3R) levels in Sjögren's syndrome (SS).@*METHODS@#Of the 30 mice, 5 were randomly selected as control, and others were used for creating SS model. After successful modeling, mice were randomly divided into 5 groups (n=5 per group) and intragastrically administered with saline (8 mL/kg), pilocarpine (1.4 mg/kg), or low, medium and high doses SGD (0.14, 0.21, 0.35 g/kg Radix paeoniae with 0.01 g/kg Radix glycyrrhizae, respectively) for 6 weeks. Human labial gland acinar cells were treated with pilocarpine or varying doses of SGD with saline as the placebo. Hematoxylin and eosin staining was used to observe the histopathological changes of the submandibular glands of mice. The serum levels of anti-SS antigen A (SS-A), anti-SS antigen B (SS-B), M3R, and α-fodrin in submandibular glands of mice were measured by enzyme-linked immunosorbent assay. Immunofluorescence staining was used to observe the spatial localization of AQP5 and M3R in acinar cells. Reverse transcriptase polymerase chain reaction and Western blot were used to detect the expressions of PKA, cAMP, Epac1, AQP5, M3R, nuclear factor kappa-B (NF-κB), and tumor necrosis factor (TNF)-α in submandibular gland tissues and cells of each group.@*RESULTS@#Compared to normal mice, body weight, 5-min salivary secretion, 30-min secretion of tears and breakup time of tear film of model mice decreased at 1-6 weeks after immunization (all P<0.05), whereas water intake increased (all P<0.05). In the model group, glands of the submandibular glands showed atrophy, accompanied by acini of different sizes, decreased numbers and loose arrangement, with catheter dilatation and different degrees of lymphocyte infiltration. Conditions of mice in SGD groups were improved. The positive expression of AQP5 and M3R were higher in the acinar cells treated with all doses SGD compared to the normal group; serum levels of SS-A, SS-B, and α-fodrin were lower, and that of M3R was higher in all doses SGD treated animals than the model or pilocarpine treated ones (all P<0.05). Compared to the model and pilocarpine groups, the mRNA and protein levels of NF-κB and TNF-α were lower in mice or cells treated with medium or high-dose SGD (all P<0.05), while those of PKA, Epac1, AQP5 and M3R were higher (all P<0.05).@*CONCLUSION@#SGD can improve symptoms of SS by regulating the cAMP-PKA signaling pathway and increasing AQP5 and M3R levels.

Comparison of the effect between electroacupuncture and NSAIDs on pain memory based on cAMP/PKA/CREB pathway in anterior cingulate gyrus / 中国针灸

OBJECTIVE@#To observe the direct intervention effects of electroacupuncture (EA) and non-steroid anti-inflammatory drugs (NSAIDs) on pain memory, and to explore their effects on cAMP/PKA/cAMP pathway in anterior cingulate gyrus (ACC).@*METHODS@#Fifty clean healthy male SD rats were randomly divided into a control group, a model group, an indomethacin group, an EA group and a sham EA group, 10 rats in each group. Except the control group, the pain memory model was established in the remaining four groups by twice injection of carrageenan at foot; 0.1 mL of 2%λ-carrageenan was subcutaneously injected at the left foot of rats; 14 days later, when the pain threshold of rats of each group returned to the basic level, the second injection was performed with the same procedure. The rats in the EA group were treated with EA at bilateral "Zusanli" (ST 36) for 30 min; the rats in the indomethacin group was treated with indomethacin intragastric administration with the dose of 3 mg/kg; the rats in the sham EA group was treated with EA without electricity at the point 0.3 mm forward "Zusanli" (ST 36) with the depth of 2 mm for 30 min; the rats in the control group was not given any invention. All the above interventions were performed 5 h, 1 d, 2 d and 3 d after the second injection of 2% λ-carrageenan. The left-side paw withdrawal thresholds (PWT) were observed before the first injection, 4 h, 3 d, 5 d after the first injection, before the second injection and 4 h, 1 d, 2 d, 3 d after the second injection. Three days after the second injection, the number of positive cells of cAMP, p-PKA, p-CREB and the number of positive cells of protein co-expression in the right ACC brain area were detected by immunofluorescence, and the relative protein expression of p-PKA and p-CREB were detected by Western blot.@*RESULTS@#Compared with the control group, the PWTs in the model group decreased significantly 4 h, 3 d and 5 d after the first injection and 1 d, 2 d and 3 d after the second injection (<0.05); compared with the control group, the positive expression of cAMP, p-PKA and p-CREB in the right ACC brain area in the model group increased significantly (<0.05), and the number of positive cells of the co-expression of cAMP/p-PKA and p-PKA/p-CREB also increased significantly (<0.05). Compared with the model group, indomethacin group and sham EA group, the PWTs in the EA group were increased significantly 1 d, 2 d and 3 d after the second injection (<0.05); compared with the model group, indomethacin group and sham EA group, the positive expression of p-PKA and p-CREB in the right ACC brain area in the EA group decreased significantly (<0.05), and the number of positive cells of co-expression of cAMP/p-PKA and p-PKA/p-CREB was decreased significantly (<0.05). Compared with the model group and sham EA group, the positive expression of cAMP in the right ACC brain area was decreased in the EA group (<0.05).@*CONCLUSION@#EA have a direct intervention effect on pain memory, which have significant advantage over NSAIDs in the treatment of chronic pain. The advantage effect of EA on pain memory may be related to the inhibition of cAMP/PKA/CREB pathway in ACC area.

Insulin-like growth factor 1 modulates the phosphorylation, expression, and activity of organic anion transporter 3 through protein kinase A signaling pathway

Organic anion transporter 3 (OAT3) plays a vital role in removing a broad variety of anionic drugs from kidney, thus avoiding their possible toxicity in the body. In the current study, we investigated the role of insulin-like growth factor 1 (IGF-1) in the regulation of OAT3. We showed that IGF-1 induced a dose- and time-dependent increase in OAT3 transport activity, which correlated well with an increase in OAT3 expression. The IGF-1-induced increase in OAT3 expression was blocked by protein kinase A (PKA) inhibitor H89. Moreover, IGF-1 induced an increase in OAT3 phosphorylation, which was also blocked by H89. These data suggest that the IGF-1 modulation of OAT3 occurred through PKA signaling pathway. To further confirm the involvement of PKA, we treated OAT3-expressing cells with PKA activator Bt2-cAMP, followed by examining OAT activity and phosphorylation. We showed that OAT3 activity and phosphorylation were much enhanced in Bt2-cAMP-treated cells as compared to that in control cells. Finally, linsitinib, an anticancer drug that blocks the IGF-1 receptor, abrogated IGF-1-stimulated OAT3 transport activity. In conclusion, our study demonstrated that IGF-1 regulates OAT3 expression and transport activity through PKA signaling pathway, possibly by phosphorylating the transporter.