Development and validation of a machine learning-based early prediction model for massive intraoperative bleeding in patients with primary hepatic malignancies.

BACKGROUND: Surgical resection remains the primary treatment for hepatic malignancies, and intraoperative bleeding is associated with a significantly increased risk of death. Therefore, accurate prediction of intraoperative bleeding risk in patients with hepatic malignancies is essential to preventing bleeding in advance and providing safer and more effective treatment. AIM: To develop a predictive model for intraoperative bleeding in primary hepatic malignancy patients for improving surgical planning and outcomes. METHODS: The retrospective analysis enrolled patients diagnosed with primary hepatic malignancies who underwent surgery at the Hepatobiliary Surgery Department of the Fourth Hospital of Hebei Medical University between 2010 and 2020. Logistic regression analysis was performed to identify potential risk factors for intraoperative bleeding. A prediction model was developed using Python programming language, and its accuracy was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: Among 406 primary liver cancer patients, 16.0% (65/406) suffered massive intraoperative bleeding. Logistic regression analysis identified four variables as associated with intraoperative bleeding in these patients: ascites [odds ratio (OR): 22.839; P < 0.05], history of alcohol consumption (OR: 2.950; P < 0.015), TNM staging (OR: 2.441; P < 0.001), and albumin-bilirubin score (OR: 2.361; P < 0.001). These variables were used to construct the prediction model. The 406 patients were randomly assigned to a training set (70%) and a prediction set (30%). The area under the ROC curve values for the model's ability to predict intraoperative bleeding were 0.844 in the training set and 0.80 in the prediction set. CONCLUSION: The developed and validated model predicts significant intraoperative blood loss in primary hepatic malignancies using four preoperative clinical factors by considering four preoperative clinical factors: ascites, history of alcohol consumption, TNM staging, and albumin-bilirubin score. Consequently, this model holds promise for enhancing individualised surgical planning.

Bioinspired Lipoproteins of Furoxans-Gemcitabine Preferentially Targets Glioblastoma and Overcomes Radiotherapy Resistance.

Radiotherapy (RT) resistance is an enormous challenge in glioblastoma multiforme (GBM) treatment, which is largely associated with DNA repair, poor distribution of reactive radicals in tumors, and limited delivery of radiosensitizers to the tumor sites. Inspired by the aberrant upregulation of RAD51 (a critical protein of DNA repair), scavenger receptor B type 1 (SR-B1), and C-C motif chemokine ligand 5 (CCL5) in GBM patients, a reduction-sensitive nitric oxide (NO) donor conjugate of gemcitabine (RAD51 inhibitor) (NG) is synthesized as radio-sensitizer and a CCL5 peptide-modified bioinspired lipoprotein system of NG (C-LNG) is rationally designed, aiming to preferentially target the tumor sites and overcome the RT resistance. C-LNG can preferentially accumulate at the orthotopic GBM tumor sites with considerable intratumor permeation, responsively release the gemcitabine and NO, and then generate abundant peroxynitrite (ONOO- ) upon X-ray radiation, thereby producing a 99.64% inhibition of tumor growth and a 71.44% survival rate at 120 days in GL261-induced orthotopic GBM tumor model. Therefore, the rationally designed bioinspired lipoprotein of NG provides an essential strategy to target GBM and overcome RT resistance.

Dual-crosslinked methacrylamide chitosan/poly(ε-caprolactone) nanofibers sequential releasing of tannic acid and curcumin drugs for accelerating wound healing.

The objective of this research study is to develop novel composite nanofibers based on methacrylamide chitosan (ChMA)/poly(ε-caprolactone) (PCL) materials by the dual crosslinking and coaxial-electrospinning strategies. The prepared ChMA/PCL composite nanofibers can sequentially deliver tannic acid and curcumin drugs to synergistically inhibit bacterial reproduction and accelerate wound healing. The rapid delivery of tannic acid is expected to inhibit pathogenic microorganisms and accelerate epithelialization in the early stage, while the slow and sustained release of curcumin is with the aim of relieving chronic inflammatory response and inducing dermal tissue maturation in the late stage. Meanwhile, dual-drugs sequentially released from the membrane exhibited a DPPH free radical scavenging rate of ca. 95 % and an antibacterial rate of above 85 %. Moreover, the membrane possessed great biocompatibility in vitro and significantly inhibited the release of pro-inflammatory factors (IL-1ß and TNF-α) in vivo. Animal experiments showed that the composite membrane by means of the synergistic effect of polyphenol drugs and ChMA nanofibers, could significantly alleviate macrophage infiltration and accelerate the healing process of wounds. From the above, the as-prepared ChMA-based membrane with a stage-wise release pattern of drugs could be a promising bioengineered construct for wound healing application.

Machine learning immune-related gene based on KLRB1 model for predicting the prognosis and immune cell infiltration of breast cancer.

Objective: Breast cancer is a prevalent malignancy that predominantly affects women. The development and progression of this disease are strongly influenced by the tumor microenvironment and immune infiltration. Therefore, investigating immune-related genes associated with breast cancer prognosis is a crucial approach to enhance the diagnosis and treatment of breast cancer. Methods: We analyzed data from the TCGA database to determine the proportion of invasive immune cells, immune components, and matrix components in breast cancer patients. Using this data, we constructed a risk prediction model to predict breast cancer prognosis and evaluated the correlation between KLRB1 expression and clinicopathological features and immune invasion. Additionally, we investigated the role of KLRB1 in breast cancer using various experimental techniques including real-time quantitative PCR, MTT assays, Transwell assays, Wound healing assays, EdU assays, and flow cytometry. Results: The functional enrichment analysis of immune and stromal components in breast cancer revealed that T cell activation, differentiation, and regulation, as well as lymphocyte differentiation and regulation, play critical roles in determining the status of the tumor microenvironment. These DEGs are therefore considered key factors affecting TME status. Additionally, immune-related gene risk models were constructed and found to be effective predictors of breast cancer prognosis. Further analysis through KM survival analysis and univariate and multivariate Cox regression analysis demonstrated that KLRB1 is an independent prognostic factor for breast cancer. KLRB1 is closely associated with immunoinfiltrating cells. Finally, in vitro experiments confirmed that overexpression of KLRB1 inhibits breast cancer cell proliferation, migration, invasion, and DNA replication ability. KLRB1 was also found to inhibit the proliferation of breast cancer cells by blocking cell division in the G1/M phase. Conclusion: KLRB1 may be a potential prognostic marker and therapeutic target associated with the microenzymic environment of breast cancer tumors, providing a new direction for breast cancer treatment.

Dispersed Nickel Phthalocyanine Molecules on Carbon Nanotubes as Cathode Catalysts for Li-CO2 Batteries.

The Li-CO2 battery has great potential for both CO2 utilization and energy storage, but its practical application is limited by low energy efficiency and short cycle life. Efficient cathode catalysts are needed to address this issue. Herein, this work reports on molecularly dispersed electrocatalysts (MDEs) of nickel phthalocyanine (NiPc) anchored on carbon nanotubes (CNTs) as the cathode catalyst for Li-CO2 batteries. The dispersed NiPc molecules efficiently catalyze CO2 reduction, while the conductive and porous CNTs networks facilitate CO2 evolution reaction, leading to enhanced discharging and charging performance compared to the NiPc and CNTs mixture. Octa-cyano substitution on NiPc (NiPc-CN) further enhances the interaction between the molecule and CNTs, resulting in better cycling stability. The Li-CO2 battery with the NiPc-CN MDE cathode shows a high discharge voltage of 2.72 V and a small discharging-charging potential gap of 1.4 V, and can work stably for over 120 cycles. The reversibility of the cathode is confirmed by experimental characterizations. This work lays a foundation for the development of molecular catalysts for Li-CO2 battery cathodes.

A green strategy to recycle the waste PP melt-blown materials: From 2D to 3D construction.

The demand for polypropylene (PP) melt-blown materials has dramatically increased due to the COVID-19 pandemic. It has caused serious environmental problems because of the lack of effective treatment for the waste PP melt-blown materials. In this study, we propose a green and sustainable recycling method to create PP sponges from waste PP melt-blown material for oil spill cleaning by freeze-drying and thermal treatment techniques. The recycling method is simple and without secondary pollution to the environment. The developed recycling method successfully transforms 2D laminar dispersed PP microfibers into elastic sponges with a 3D porous structure, providing the material with good mechanical properties and promotes its potential application in the field of oil spill cleaning. The morphology structure, thermal properties, mechanical properties, and oil absorption properties are tested and characterized. The PP sponges with a three-dimensional porous network structure show an exceedingly low density of >0.014 g/cm3, a high porosity of <98.77 %, and a high water contact angle range of 130.4-139.9°. Moreover, the PP sponges own a good absorption capacity of <47.61 g/g for different oil and solvents. In particular, the compressive modulus of the PP sponges is 33.59-201.21 kPa, which is higher than that of most other fiber-based porous materials, indicating that the PP sponges have better durability under the same force. The excellent comprehensive performance of the PP sponges demonstrates the method developed in this study has large application potential in the field of the recycle of waste PP melt-blown materials.

Regulating Morphological Features of Nickel Single-Atom Catalysts for Selective and Enhanced Electroreduction of CO2.

Single-atom catalysts (SACs) are of interest for chemical transformations of significant energy and environmental relevance because of the envisioned efficient use of active sites and the flexibility in tuning their coordination environment. Future advancement in this vein hinges upon the ability to further increase the number and accessibility of active sites in addition to fine-tuning their chemical environment. In this work, a Ni SAC is reported with a unique hierarchical hollow structure (Ni/HH) that allows increased accessibility of the active sites. The successful obtainment of such a uniquely structured catalyst was enabled by the judiciously chosen solvent mixtures for the preparation of the precursor whose hierarchical feature is maintained during the subsequent pyrolysis and etching of the pyrolysis product. Comparative catalytic and mechanistic studies with reference to three closely related but more compact Ni SACs established the superior performance of Ni/HH for selective electroreduction of CO2 to CO. Experimental analyses by in situ attenuated total reflection surface-enhanced infrared spectroscopy reveal that it is the facilitated formation of the *COOH intermediate in the rate-determining step that leads to the enhanced reaction kinetics and the overall catalytic performance.

The prognostic impact of immune checkpoint inhibitors for the treatment of pulmonary sarcomatoid carcinoma: A multicenter retrospective study.

Pulmonary sarcomatoid carcinoma (PSC) is an aggressive and poorly differentiated type of non-small cell lung carcinoma. Because of the rarity of PSC, the efficacy and toxicity of immunotherapy remain unclear. Hence, the aim of this study was to evaluate the efficacy and safety of immune checkpoint inhibitors (ICIs) for the treatment of advanced PSC. The study cohort was limited to 33 patients with pathologically confirmed PSC treated with ICIs in four hospitals in China from March 2018 to March 2022. Expression of programmed death ligand 1 (PD-L1) was detected by immunohistochemical analysis. Categorical variables were compared with the Fisher exact test and survival analysis was conducted with the Kaplan-Meier method. Of the 33 PSC patients, 8 (24.2%) received monotherapy with ICIs and 25 (75.8%) received combination therapy with ICIs. The objective response rate (ORR) and disease control rate (DCR) were 36.4% and 78.8%, respectively. The median durations of progression-free survival (PFS) and overall survival (OS) were 6.07 and 21.33 months, respectively. PD-L1 status in 16 available samples was assessed, which included 30.3% PD-L1-positive patients. The ORRs for PD-L1-positive vs. -negative patients were 50.0% and 90.0%, the DCR was 33.3% and 83.3%, and the median PFS was 17.50 and 6.07 months, respectively (p=0.812). The median OS was not reached in PD-L1-positive and -negative patients (p=0.655). The incidence of immune-related adverse (irAEs) was 48.5% and mainly included grade 1 or 2 (39.4%), while the incidence of grade 3 or 4 was 9.1%. Pneumonia (9.1%) and skin rash (9.1%) were the most frequent irAEs. Immunotherapy with ICIs was a promising regimen to improve the prognosis of patients with advanced PSC.

HDAC2 Induces DNA Methyltransferase DNMT3B Expression to Regulate the Wnt Signaling Pathway and Thus Promotes Glioma Development and Progression.

Purpose: To investigate the role and molecular mechanism of HDAC2 in glioma. Methods: GSE16011, GSE31262, and GSE90598 datasets were used to identify co-expressed genes, GO analysis, and KEGG analysis to identify gene enrichment pathways, and PPI networks were constructed to identify gene interrelationships. HDAC2 enrichment on DNMT3B promoter and DNMT3B enrichment on Bcl2 CpG island was detected by a ChIP assay. The expression, prognosis, and hierarchical distribution of HDAC2, DNMT3B, and Bcl2 were examined in the CGGA database, and the correlation between HDAC2 and DNMT3B, Bcl2, and DNMT3B and Bcl2 was assessed. Results: The HDAC2-DNMT3B-Bcl2 axis is differentially expressed and interacts in gliomas. HDAC2 activates the transcriptional activity of DNMT3B, and DNMT3B inhibits the expression of Bcl2. HDAC2 and DNMT3B are highly expressed in gliomas and have a poor prognosis, while Bcl2 is lowly expressed in gliomas and has a good prognosis. Conclusion: HDAC2 promotes DNMT3B transcriptional repression of Bcl2 expression and Wnt pathway activity, thereby activating glioma cell activity in vitro and in vivo.

A chloride-doped silver-sulfide cluster [Ag148S26Cl30(CCBut)60]6+: hierarchical assembly, enhanced luminescence and cytotoxicity to cancer cells.

The formation of high-nuclear silver(I) clusters remains elusive and their potential applications are still underdeveloped. Herein, we report an unprecedented gigantic Ag148 ([Ag148S26Cl30(CCBut)60](SbF6)6) cluster co-templated by Cl- and S2-, which was well-defined by single-crystal X-ray diffraction and high-resolution mass spectrometry. The cluster exhibits a hierarchical structure consisting of fused Ag24X16 kernel, Ag60X20 shell and "cluster of clusters assembling" of four pentagonal concave polyhedral {Ag16X5} units. Furthermore, the silver cluster emits red light at room temperature with a prominent 39.6% QY. The cellular uptake and cytotoxicity indicate that Ag148 induces apoptosis of cancer cells in a dose-dependent manner.

Stability and cytotoxicity of angiotensin-I-converting enzyme inhibitory peptides derived from bovine casein.

This study investigated the effect of heat treatment combined with acid and alkali on the angiotensin-I-converting enzyme (ACE) inhibitory activity of peptides derived from bovine casein. The free amino group content, color, and cytotoxicity of the peptides were measured under different conditions. When heated at 100 °C in the pH range from 9.0 to 12.0, ACE inhibitory activity was reduced and the appearance of the peptides was significantly darkened. After thermal treatment in the presence of acid and alkali, the free amino group content of ACE inhibitory peptides decreased markedly. High temperature and prolonged heating also resulted in the loss of ACE inhibitory activity, the loss of free amino groups, and the darker coloration of bovine casein-derived peptides. However, ACE inhibitory peptides, within a concentration range of from 0.01 to 0.2 mg/ml, showed no cytotoxicity to Caco-2 and ECV-304 cell lines after heat treatment. This indicated that high temperature and alkaline heat treatment impaired the stability of bovine casein-derived ACE inhibitory peptides.

Nav1.5-dependent persistent Na+ influx activates CaMKII in rat ventricular myocytes and N1325S mice.

Late Na(+) current (I(NaL)) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) are both increased in the diseased heart. Recently, CaMKII was found to phosphorylate the Na(+) channel 1.5 (Na(v)1.5), resulting in enhanced I(NaL). Conversely, an increase of I(NaL) would be expected to cause elevation of intracellular Ca(2+) and activation of CaMKII. However, a relationship between enhancement of I(NaL) and activation of CaMKII has yet to be demonstrated. We investigated whether Na(+) influx via Na(v)1.5 leads to CaMKII activation and explored the functional significance of this pathway. In neonatal rat ventricular myocytes (NRVM), treatment with the I(NaL) activators anemone toxin II (ATX-II) or veratridine increased CaMKII autophosphorylation and increased phosphorylation of CaMKII substrates phospholamban and ryanodine receptor 2. Knockdown of Na(v)1.5 (but not Na(v)1.1 or Na(v)1.2) prevented ATX-II-induced CaMKII phosphorylation, providing evidence for a specific role of Na(v)1.5 in CaMKII activation. In support of this view, CaMKII activity was also increased in hearts of transgenic mice overexpressing a gain-of-function Na(v)1.5 mutant (N(1325)S). The effects of both ATX-II and the N(1325)S mutation were reversed by either I(NaL) inhibition (with ranolazine or tetrodotoxin) or CaMKII inhibition (with KN93 or autocamtide 2-related inhibitory peptide). Furthermore, ATX-II treatment also induced CaMKII-Na(v)1.5 coimmunoprecipitation. The same association between CaMKII and Na(v)1.5 was also found in N(1325)S mice, suggesting a direct protein-protein interaction. Pharmacological inhibitions of either CaMKII or I(NaL) also prevented ATX-II-induced cell death in NRVM and reduced the incidence of polymorphic ventricular tachycardia induced by ATX-II in rat perfused hearts. Taken together, these results suggest that a Na(v)1.5-dependent increase in Na(+) influx leads to activation of CaMKII, which in turn phosphorylates Na(v)1.5, further promoting Na(+) influx. Pharmacological inhibition of either CaMKII or Na(v)1.5 can ameliorate cardiac dysfunction caused by excessive Na(+) influx.

Poly[[bis-(2,2-bipyridine)-bis-[µ(6)-5-(carboxyl-atometh-oxy)benzene-1,3-dicarboxyl-ato]trimanganese(II)] monohydrate].

The title compound, {[Mn(3)(C(10)H(5)O(7))(2)(C(10)H(8)N(2))(2)]·H(2)O}(n), was synthesized under hydro-thermal conditions. Six carboxyl-ate groups of six 5-(carboxyl-atometh-oxy)benzene-1,3-dicarboxyl-ate anions (OABDC(3-)) join three Mn(II) ions into a trinuclear centrosymmetric [Mn(3)(µ(2)-COO)(6)] unit with one Mn site situated on a centre of inversion. The latter Mn(II) ion exhibits a distorted MnO(6) coordination, whereas the other Mn(II) ion has a trigonal-bipyramidal MnN(2)O(3) coordination environment resulting from three carboxylate O atoms and the two N atoms of the bipyridine ligand. Adjacent units are linked to each other by OABDC(3-) ligands into a layer parallel to (010). Within the layer, O-H⋯O hydrogen-bonding inter-actions involving the uncoordinated and half-occupied water mol-ecule and the free carboxyl-ate O atoms are observed. The layers stack along [010], constructing a three-dimensional structure through π-π inter-actions between adjacent pyridine rings, with a centroid-centroid distance of 3.473 (5) Å.

[Vaginal repair operation for anterior pelvic organ prolapse in elderly women].

OBJECTIVE: To identify the safety and efficacy of individualized vaginal surgery for anterior pelvic organ prolapse (POP) in elderly women so as to provide a clinical basis for studies on improving life quality by treatment in elderly women. METHODS: The individuation group consisted of 90 patients with a diagnosis of anterior POP. All over 60 years old, they underwent individualized vaginal surgery. The safety and efficacy, POP quantitative examination POP-Q change, cure and recurrence rate and life quality scores on incontinence and pelvic floor distress and impact were assessed. The control group (n = 60) was composed of patients (> 60 yr old) with a diagnosis of anterior POP were performed with Kelly-Kennedy operation. Their safety, efficacy, cure and recurrence rates were compared. RESULTS: Individualized vaginal surgery in elderly women was both safe and effective. The post-therapeutic recovery time was shorter (P < 0.05), the cure rate higher and the recurrence rate lower (P < 0.05) than that of control group. The life quality after individualized surgery improved (P < 0.01). CONCLUSION: The individualized vaginal surgery is safe and effective for a correction of anterior POP in elderly women. The life quality improves after operation.

[Distribution model of aluminum species in drinking water basing on the reaction kinetics].

The effects of excess aluminum on water distribution system and human health were mainly attributable to the presences of some aluminum species in drinking water. A prediction model for the concentrations of aluminum species was developed using three-layer front feedback artificial neural network method. Results showed that the reaction rates of both inorganic monomeric aluminum and soluble aluminum varied with reaction time and water quality parameters, such as water temperature, pH, total aluminum, fluoride, phosphate and silicate. Their reaction orders were both three. The reaction kinetic parameters of inorganic monomeric aluminum and soluble aluminum could be predicted effectively applying artificial neural network; the correlation coefficients of k and 1/C0(2) between calculated value and predicted value were both greater than 0.999. Aluminum species prediction results in the drinking water of City M showed that when the concentration of total aluminum was less than 0.05 mg x L(-1), the relative prediction error was large for inorganic monomeric aluminum. When the concentration of total aluminum was above 0.05 mg x L(-1), the model could predict inorganic monomeric aluminum and soluble aluminum concentrations effectively, with relative prediction errors of +/- 15% and +/- 10% respectively.

[Effects of temperature and pH on the distribution of aluminum species in drinking water].

The effects of aluminum on water distribution system and human health are mainly attributable to their presence in drinking water. Laboratory experiments were performed to investigate the influence of temperature and pH on the distribution of aluminum species applying alum synthetic water. Aluminum species studied in the experiments included monomeric aluminum, soluble aluminum, suspended aluminum, and polymeric aluminum, which were determined by fluorescence spectrophotometry method. Results indicated that suspended aluminum was the major species at pH 6.5, occupied about 62.2% in the total aluminum mass concentration. While at pH above 7.0, monomeric aluminum was the major species; and varied little as reaction time increased. Polymeric aluminum mass concentration was low at studied water quality condition and also varied little as reaction time increased. The influence of temperature on aluminum species distribution was similar to solution pH; and both could be explained by pOH. Aluminum species in drinking water could be controlled by adjusting the pOH value, which provided theoretical guidance for the operation of the water distribution system and aluminum toxicity control.

Up-regulation of AGS3 during morphine withdrawal promotes cAMP superactivation via adenylyl cyclase 5 and 7 in rat nucleus accumbens/striatal neurons.

Effective medical treatment of opiate addiction is limited by a high relapse rate in abstinent addicts. Opiate withdrawal causes cAMP superactivation, but the underlying molecular mechanisms are not clear. Recent evidence implicates an activator of G-protein signaling 3 (AGS3) in opiate addiction. We found previously that during a 10-min activation of opioid receptors, AGS3 binds G alpha(i)-GDP to promote free G betagamma stimulation of adenylyl cyclase (AC) 2 and 4, and/or inactivate G alpha(i) inhibitory function, thereby transiently enhancing cAMP-dependent protein kinase A (PKA) activity. In contrast, we report here that in nucleus accumbens/striatal neurons, morphine withdrawal induces cAMP superactivation, which requires up-regulation of AGS3. cAMP increases as a function of withdrawal time, by approximately 20% at 10 min and 75% at 5 h. However, cAMP superactivation does not require G betagamma. Instead, adenosine A2A receptor activation of G alpha(s/olf) seems to initiate cAMP superactivation and promote AGS3 up-regulation. Elevated AGS3 binds to G alpha(i) to prevent its inhibition on AC activation. Moreover, withdrawal-induced increases in cAMP/PKA activate phospholipase C and epsilon protein kinase C to further stimulate AC5 and AC7, causing cAMP superactivation. Our findings identify a critical role for AC 5 and 7 and A2A receptors for up-regulation of AGS3 in morphine withdrawal-induced cAMP superactivation.

Dopamine and ethanol cause translocation of epsilonPKC associated with epsilonRACK: cross-talk between cAMP-dependent protein kinase A and protein kinase C signaling pathways.

We found previously that neural responses to ethanol and the dopamine D2 receptor (D2) agonist 2,10,11-trihydroxy-N-propylnorapomorphine hydrobromide (NPA) involve both epsilon protein kinase C (epsilonPKC) and cAMP-dependent protein kinase A (PKA). However, little is known about the mechanism underlying ethanol- and D2-mediated activation of epsilonPKC and the relationship to PKA activation. In the present study, we used a new epsilonPKC antibody, 14E6, that selectively recognized active epsilonPKC when not bound to its anchoring protein epsilonRACK (receptor for activated C-kinase), and PKC isozyme-selective inhibitors and activators to measure PKC translocation and catalytic activity. We show here that ethanol and NPA activated epsilonPKC and induced translocation of both epsilonPKC and its anchoring protein, epsilonRACK to a new cytosolic site. The selective epsilonPKC agonist, pseudo-epsilonRACK, activated epsilonPKC but did not cause translocation of the epsilonPKC/epsilonRACK complex to the cytosol. These data suggest a step-wise activation and translocation of epsilonPKC after NPA or ethanol treatment, where epsilonPKC first translocates and binds to its RACK and subsequently the epsilonPKC/epsilonRACK complex translocates to a new subcellular site. Direct activation of PKA by adenosine-3',5'-cyclic monophosphorothioate, Sp-isomer (Sp-cAMPS), prostaglandin E1, or the adenosine A2A receptor is sufficient to cause epsilonPKC translocation to the cytosolic compartment in a process that is dependent on PLC activation and requires PKA activity. These data demonstrate a novel cross-talk mechanism between epsilonPKC and PKA signaling systems. PKA and PKC signaling have been implicated in alcohol rewarding properties in the mesolimbic dopamine system. Cross-talk between PKA and PKC may underlie some of the behaviors associated with alcoholism.

Nicotine and ethanol activate protein kinase A synergistically via G(i) betagamma subunits in nucleus accumbens/ventral tegmental cocultures: the role of dopamine D(1)/D(2) and adenosine A(2A) receptors.

Tobacco and alcohol are the most commonly used drugs of abuse and show the most serious comorbidity. The mesolimbic dopamine system contributes significantly to nicotine and ethanol reinforcement, but the underlying cellular signaling mechanisms are poorly understood. Nicotinic acetylcholine (nACh) receptors are highly expressed on ventral tegmental area (VTA) dopamine neurons, with relatively low expression in nucleus accumbens (NAcb) neurons. Because dopamine receptors D(1) and D(2) are highly expressed on NAcb neurons, nicotine could influence NAcb neurons indirectly by activating VTA neurons to release dopamine in the NAcb. To investigate this possibility in vitro, we established primary cultures containing neurons from VTA or NAcb separately or in cocultures. Nicotine increased cAMP response element-mediated gene expression only in cocultures; this increase was blocked by nACh or dopamine D(1) or D(2) receptor antagonists. Furthermore, subthreshold concentrations of nicotine with ethanol increased gene expression in cocultures, and this increase was blocked by nACh, D(2) or adenosine A(2A) receptor antagonists, Gbetagamma or protein kinase A (PKA) inhibitors, and adenosine deaminase. These results suggest that nicotine activated VTA neurons, causing the release of dopamine, which in turn stimulated both D(1) and D(2) receptors on NAcb neurons. In addition, subthreshold concentrations of nicotine and ethanol in combination also activated NAcb neurons through synergy between D(2) and A(2A) receptors. These data provide a novel cellular mechanism, involving Gbetagamma subunits, A(2A) receptors, and PKA, whereby combined use of tobacco and alcohol could enhance the reinforcing effect in humans as well as facilitate long-term neuroadaptations, increasing the risk for developing coaddiction.