Characterization of wooden breast myopathy: a focus on syndecans and ECM remodeling

Introduction: The skeletal muscle deformity of commercial chickens (Gallus gallus), known as the wooden breast (WB), is associated with fibrotic myopathy of unknown etiology. For future breeding strategies and genetic improvements, it is essential to identify the molecular mechanisms underlying the phenotype. The pathophysiological hallmarks of WB include severe skeletal muscle fibrosis, inflammation, myofiber necrosis, and multifocal degeneration of muscle tissue. The transmembrane proteoglycans syndecans have a wide spectrum of biological functions and are master regulators of tissue homeostasis. They are upregulated and shed (cleaved) as a regulatory mechanism during tissue repair and regeneration. During the last decades, it has become clear that the syndecan family also has critical functions in skeletal muscle growth, however, their potential involvement in WB pathogenesis is unknown. Methods: In this study, we have categorized four groups of WB myopathy in broiler chickens and performed a comprehensive characterization of the molecular and histological profiles of two of them, with a special focus on the role of the syndecans and remodeling of the extracellular matrix (ECM). Results and discussion: Our findings reveal differential expression and shedding of the four syndecan family members and increased matrix metalloproteinase activity. Additionally, we identified alterations in key signaling pathways such as MAPK, AKT, and Wnt. Our work provides novel insights into a deeper understanding of WB pathogenesis and suggests potential therapeutic targets for this condition.

Polyarginine Cell-Penetrating Peptides Bind and Inhibit SERCA2

Cell-penetrating peptides (CPPs) are short peptide sequences that have the ability to cross the cell membrane and deliver cargo. Although it is critical that CPPs accomplish this task with minimal off-target effects, such actions have in many cases not been robustly screened. We presently investigated whether the commonly used CPPs TAT and the polyarginines Arg9 and Arg11 exert off-target effects on cellular Ca2+ homeostasis. In experiments employing myocytes and homogenates from the cardiac left ventricle or soleus muscle, we observed marked inhibition of Ca2+ recycling into the sarcoplasmic reticulum (SR) following incubation with polyarginine CPPs. In both tissues, the rate of SR Ca2+ leak remained unchanged, indicating that protracted Ca2+ removal from the cytosol stemmed from inhibition of the SR Ca2+ ATPase 2 (SERCA2). No such inhibition occurred following treatment with TAT, or in preparations from the SERCA1-expressing extensor digitorum longus muscle. Experiments in HEK cells overexpressing individual SERCA isoforms confirmed that polyarginine incubation specifically inhibited the activity of SERCA2a and 2b, but not SERCA1 or 3. The attenuation of SERCA2 activity was not dependent on the presence of phospholamban, and ELISA-based analyses rather revealed direct interaction between the polyarginines and the actuator domain of the protein. Surface plasmon resonance experiments confirmed strong binding within this region of SERCA2, and slow dissociation between the two species. Based on these observations, we urge caution when employing polyarginine CPPs. Indeed, as SERCA2 is expressed in diverse cell types, the wide-ranging consequences of SERCA2 binding and inhibition should be anticipated in both experimental and therapeutic settings.

Two Transient Receptor Potential Channels at Focal Adhesions

Recently there have been reports that identify two transient receptor potential channels in cell-matrix junctions known as focal adhesions. These are the calcium channel TRP canonical 7 and the calcium-activated monovalent ion channel, TRP melastatin (TRPM) 4. Here, we report on the occurrence of TRPM4 in focal adhesions of fibroblasts. Of three commercial antibodies recognizing this channel, only one yielded focal adhesion staining, while the other two did not. The epitope recognized by the focal adhesion-localizing antibody was mapped to the extreme C-terminus of the TRPM4 protein. The other two antibodies bind to N-terminal regions of the TRPM4 proteins. Deletion of the TRPM4 gene by CRISPR/cas9 techniques confirmed that this channel is a bona fide focal adhesion component, while expression of full-length TRPM4 proteins suggested that processing may occur to yield a form that localizes to focal adhesions. Given the reports that this channel may influence migratory behavior of cells and is linked to cardiovascular disease, TRPM4 functions in adhesion should be explored in greater depth. (J Histochem Cytochem 71: 495-508, 2023).

Inhibition of the extracellular enzyme A disintegrin and metalloprotease with thrombospondin motif 4 prevents cardiac fibrosis and dysfunction

AIMS

Heart failure is a condition with high mortality rates, and there is a lack of therapies that directly target maladaptive changes in the extracellular matrix (ECM), such as fibrosis. We investigated whether the ECM enzyme known as A disintegrin and metalloprotease with thrombospondin motif (ADAMTS) 4 might serve as a therapeutic target in treatment of heart failure and cardiac fibrosis.

METHODS AND RESULTS

The effects of pharmacological ADAMTS4 inhibition on cardiac function and fibrosis were examined in rats exposed to cardiac pressure overload. Disease mechanisms affected by the treatment were identified based on changes in the myocardial transcriptome. Following aortic banding, rats receiving an ADAMTS inhibitor, with high inhibitory capacity for ADAMTS4, showed substantially better cardiac function than vehicle-treated rats, including ∼30% reduction in E/e' and left atrial diameter, indicating an improvement in diastolic function. ADAMTS inhibition also resulted in a marked reduction in myocardial collagen content and a down-regulation of transforming growth factor (TGF)-β target genes. The mechanism for the beneficial effects of ADAMTS inhibition was further studied in cultured human cardiac fibroblasts producing mature ECM. ADAMTS4 caused a 50% increase in the TGF-β levels in the medium. Simultaneously, ADAMTS4 elicited a not previously known cleavage of TGF-β-binding proteins, i.e. latent-binding protein of TGF-β and extra domain A-fibronectin. These effects were abolished by the ADAMTS inhibitor. In failing human hearts, we observed a marked increase in ADAMTS4 expression and cleavage activity.

CONCLUSION

Inhibition of ADAMTS4 improves cardiac function and reduces collagen accumulation in rats with cardiac pressure overload, possibly through a not previously known cleavage of molecules that control TGF-β availability. Targeting ADAMTS4 may serve as a novel strategy in heart failure treatment, in particular, in heart failure with fibrosis and diastolic dysfunction.

Disruption of Phosphodiesterase 3A Binding to SERCA2 Increases SERCA2 Activity and Reduces Mortality in Mice With Chronic Heart Failure

BACKGROUND

Increasing SERCA2 (sarco[endo]-plasmic reticulum Ca2+ ATPase 2) activity is suggested to be beneficial in chronic heart failure, but no selective SERCA2-activating drugs are available. PDE3A (phosphodiesterase 3A) is proposed to be present in the SERCA2 interactome and limit SERCA2 activity. Disruption of PDE3A from SERCA2 might thus be a strategy to develop SERCA2 activators.

METHODS

Confocal microscopy, 2-color direct stochastic optical reconstruction microscopy, proximity ligation assays, immunoprecipitations, peptide arrays, and surface plasmon resonance were used to investigate colocalization between SERCA2 and PDE3A in cardiomyocytes, map the SERCA2/PDE3A interaction sites, and optimize disruptor peptides that release PDE3A from SERCA2. Functional experiments assessing the effect of PDE3A-binding to SERCA2 were performed in cardiomyocytes and HEK293 vesicles. The effect of SERCA2/PDE3A disruption by the disruptor peptide OptF (optimized peptide F) on cardiac mortality and function was evaluated during 20 weeks in 2 consecutive randomized, blinded, and controlled preclinical trials in a total of 148 mice injected with recombinant adeno-associated virus 9 (rAAV9)-OptF, rAAV9-control (Ctrl), or PBS, before undergoing aortic banding (AB) or sham surgery and subsequent phenotyping with serial echocardiography, cardiac magnetic resonance imaging, histology, and functional and molecular assays.

RESULTS

PDE3A colocalized with SERCA2 in human nonfailing, human failing, and rodent myocardium. Amino acids 277-402 of PDE3A bound directly to amino acids 169-216 within the actuator domain of SERCA2. Disruption of PDE3A from SERCA2 increased SERCA2 activity in normal and failing cardiomyocytes. SERCA2/PDE3A disruptor peptides increased SERCA2 activity also in the presence of protein kinase A inhibitors and in phospholamban-deficient mice, and had no effect in mice with cardiomyocyte-specific inactivation of SERCA2. Cotransfection of PDE3A reduced SERCA2 activity in HEK293 vesicles. Treatment with rAAV9-OptF reduced cardiac mortality compared with rAAV9-Ctrl (hazard ratio, 0.26 [95% CI, 0.11 to 0.63]) and PBS (hazard ratio, 0.28 [95% CI, 0.09 to 0.90]) 20 weeks after AB. Mice injected with rAAV9-OptF had improved contractility and no difference in cardiac remodeling compared with rAAV9-Ctrl after aortic banding.

CONCLUSIONS

Our results suggest that PDE3A regulates SERCA2 activity through direct binding, independently of the catalytic activity of PDE3A. Targeting the SERCA2/PDE3A interaction prevented cardiac mortality after AB, most likely by improving cardiac contractility.

Synapsin 2 regulates NCX1 trafficking and is down-regulated in the failing myocardium, which increases the risk of ventricular arrhythmia and heart failure mortality

Background

Synapsin 2 (Syn2) modulates vesicle transport in the post-synaptic terminal in the brain, and has been linked to sudden unexplained death in epilepsy, but has never previously been studied in the myocardium.

Purpose

Given the association of vesicle transport in the brain and the heart, and the similarity of sudden death in epilepsy and cardiac arrhythmias, we have studied the role of Syn2 in the heart.

Methods

We explored left ventricular (LV) Syn2 levels in various experimental heart failure (HF) models and assessed mortality in Syn2 knock out (KO) mice vs. wild type (WT) littermates after pressure-overload induced by aortic banding. We used confocal imaging and virus transduction to characterize Syn2 localization and co-localization with NCX and Rab proteins. We verified Syn2-NCX interaction by immunoprecipitation, mass spectrometry, and surface resonance experiments. We investigated calcium handling in isolated cardiomyocytes. Susceptibility for ventricular arrhythmias was also tested in Langendorff-perfused hearts.

Results

We found Syn2, but not synapsin 1, to be expressed in the myocardium. LV Syn2 levels were markedly downregulated in the failing myocardium after experimental myocardial infarction or aortic banding. Syn2 KO mice had increased mortality compared to WT littermates following aortic banding, but demonstrated no clear clinical or echocardiographic phenotype, except reduced fractional shortening. Given no clear etiology for increased mortality, we next explored the association between Syn2 and ion-channel vesicle transport, calcium handling and ventricular arrhythmias. By confocal imaging and viral transduction, we found Syn2 to localize in vesicles in HL-1 cells, where Syn2 co-localized with Rab2, Rab3, Rab7 and NCX1. Syn2 was also found to interact with NCX1 as tested by immunoprecipitation, mass spectrometry, and surface resonance experiments. NCX1 levels were downregulated in the membrane fraction in the left ventricle of Syn2 KO mice compared to WT littermates following aortic banding. We observed increased frequency of calcium sparks and waves in isolated Syn2 KO cardiomyocytes compared to controls. We found enhanced susceptibility of Syn2 KO mice for ventricular arrhythmias compared to WT littermates mice during ISO stress testing in explanted hearts. Hearts from Syn2 KO mice also demonstrated more severe ventricular arrhythmias compared to hearts from WT littermates controls.

Conclusions

We report for the first time that Syn2 is expressed in the myocardium and that Syn2 seems to regulate NCX1 transport and localization. We also found markedly reduced LV Syn2 levels in HF individuals and mice that lacked Syn2 more frequent displayed severe ventricular arrhythmias and had increased mortality. Hence, our data suggest that reduced Syn2 in the failing myocardium may lead to increased mortality, possibly linked to altered NCX trafficking and subsequent ventricular arrhythmias.

Funding Acknowledgement

Type of funding sources: None.

The female syndecan-4−/− heart has smaller cardiomyocytes, augmented insulin/pSer473-Akt/pSer9-GSK-3β signaling, and lowered SCOP, pThr308-Akt/Akt and GLUT4 levels

Background: In cardiac muscle, the ubiquitously expressed proteoglycan syndecan-4 is involved in the hypertrophic response to pressure overload. Protein kinase Akt signaling, which is known to regulate hypertrophy, has been found to be reduced in the cardiac muscle of exercised male syndecan-4−/− mice. In contrast, we have recently found that pSer473-Akt signaling is elevated in the skeletal muscle (tibialis anterior, TA) of female syndecan-4−/− mice. To determine if the differences seen in Akt signaling are sex specific, we have presently investigated Akt signaling in the cardiac muscle of sedentary and exercised female syndecan-4−/− mice. To get deeper insight into the female syndecan-4−/− heart, alterations in cardiomyocyte size, a wide variety of different extracellular matrix components, well-known syndecan-4 binding partners and associated signaling pathways have also been investigated.

Methods: Left ventricles (LVs) from sedentary and exercise trained female syndecan-4−/− and WT mice were analyzed by immunoblotting and real-time PCR. Cardiomyocyte size and phosphorylated Ser473-Akt were analyzed in isolated adult cardiomyocytes from female syndecan-4−/− and WT mice by confocal imaging. LV and skeletal muscle (TA) from sedentary male syndecan-4−/− and WT mice were immunoblotted with Akt antibodies for comparison. Glucose levels were measured by a glucometer, and fasting blood serum insulin and C-peptide levels were measured by ELISA.

Results: Compared to female WT hearts, sedentary female syndecan-4−/− LV cardiomyocytes were smaller and hearts had higher levels of pSer473-Akt and its downstream target pSer9-GSK-3β. The pSer473-Akt inhibitory phosphatase PHLPP1/SCOP was lowered, which may be in response to the elevated serum insulin levels found in the female syndecan-4−/− mice. We also observed lowered levels of pThr308-Akt/Akt and GLUT4 in the female syndecan-4−/− heart and an increased LRP6 level after exercise. Otherwise, few alterations were found. The pThr308-Akt and pSer473-Akt levels were unaltered in the cardiac and skeletal muscles of sedentary male syndecan-4−/− mice.

Conclusion: Our data indicate smaller cardiomyocytes, an elevated insulin/pSer473-Akt/pSer9-GSK-3β signaling pathway, and lowered SCOP, pThr308-Akt/Akt and GLUT4 levels in the female syndecan-4−/− heart. In contrast, cardiomyocyte size, and Akt signaling were unaltered in both cardiac and skeletal muscles from male syndecan-4−/− mice, suggesting important sex differences.

Design of a Proteolytically Stable Sodium-Calcium Exchanger 1 Activator Peptide for In Vivo Studies

The cardiac sodium–calcium exchanger (NCX1) is important for normal Na⁺- and Ca²⁺-homeostasis and cardiomyocyte relaxation and contraction. It has been suggested that NCX1 activity is reduced by phosphorylated phospholemman (pSer68-PLM); however its direct interaction with PLM is debated. Disruption of the potentially inhibitory pSer68-PLM-NCX1 interaction might be a therapeutic strategy to increase NCX1 activity in cardiac disease. In the present study, we aimed to analyze the binding affinities and kinetics of the PLM-NCX1 and pSer68-PLM-NCX1 interactions by surface plasmon resonance (SPR) and to develop a proteolytically stable NCX1 activator peptide for future in vivo studies. The cytoplasmic parts of PLM (PLM_cyt) and pSer68-PLM (pSer68-PLM_cyt) were found to bind strongly to the intracellular loop of NCX1 (NCX1_cyt) with similar K_D values of 4.1 ± 1.0 nM and 4.3 ± 1.9 nM, but the PLM_cyt-NCX1_cyt interaction showed higher on/off rates. To develop a proteolytically stable NCX1 activator, we took advantage of a previously designed, high-affinity PLM binding peptide (OPT) that was derived from the PLM binding region in NCX1 and that reverses the inhibitory PLM (S68D)-NCX1 interaction in HEK293. We performed N- and C-terminal truncations of OPT and identified PYKEIEQLIELANYQV as the minimum sequence required for pSer68-PLM binding. To increase peptide stability in human serum, we replaced the proline with an N-methyl-proline (NOPT) after identification of N-terminus as substitution tolerant by two-dimensional peptide array analysis. Mass spectrometry analysis revealed that the half-life of NOPT was increased 17-fold from that of OPT. NOPT pulled down endogenous PLM from rat left ventricle lysate and exhibited direct pSer68-PLM binding in an ELISA-based assay and bound to pSer68-PLM_cyt with a K_D of 129 nM. Excess NOPT also reduced the PLM_cyt-NCX1_cyt interaction in an ELISA-based competition assay, but in line with that NCX1 and PLM form oligomers, NOPT was not able to outcompete the physical interaction between endogenous full length proteins. Importantly, cell-permeable NOPT-TAT increased NCX1 activity in cardiomyocytes isolated from both SHAM-operated and aorta banded heart failure (HF) mice, indicating that NOPT disrupted the inhibitory pSer68-PLM-NCX1 interaction. In conclusion, we have developed a proteolytically stable NCX1-derived PLM binding peptide that upregulates NCX1 activity in SHAM and HF cardiomyocytes.

The Cardiac Syndecan-2 Interactome

The extracellular matrix (ECM) is important in cardiac remodeling and syndecans have gained increased interest in this process due to their ability to convert changes in the ECM to cell signaling. In particular, syndecan-4 has been shown to be important for cardiac remodeling, whereas the role of its close relative syndecan-2 is largely unknown in the heart. To get more insight into the role of syndecan-2, we here sought to identify interaction partners of syndecan-2 in rat left ventricle. By using three different affinity purification methods combined with mass spectrometry (MS) analysis, we identified 30 novel partners and 9 partners previously described in the literature, which together make up the first cardiac syndecan-2 interactome. Eleven of the novel partners were also verified in HEK293 cells (i.e., AP2A2, CAVIN2, DDX19A, EIF4E, JPH2, MYL12A, NSF, PFDN2, PSMC5, PSMD11, and RRAD). The cardiac syndecan-2 interactome partners formed connections to each other and grouped into clusters mainly involved in cytoskeletal remodeling and protein metabolism, but also into a cluster consisting of a family of novel syndecan-2 interaction partners, the CAVINs. MS analyses revealed that although syndecan-2 was significantly enriched in fibroblast fractions, most of its partners were present in both cardiomyocytes and fibroblasts. Finally, a comparison of the cardiac syndecan-2 and -4 interactomes revealed surprisingly few protein partners in common.

Coupling of the Na+/K+-ATPase to Ankyrin B controls Na+/Ca2+ exchanger activity in cardiomyocytes

AIMS

Ankyrin B (AnkB) is an adaptor protein that assembles Na+/K+-ATPase (NKA) and Na+/Ca2+ exchanger (NCX) in the AnkB macromolecular complex. Loss-of-function mutations in AnkB cause the AnkB syndrome in humans, characterized by ventricular arrhythmias and sudden cardiac death. It is unclear to what extent NKA binding to AnkB allows regulation of local Na+ and Ca2+ domains and hence NCX activity.

METHODS AND RESULTS

To investigate the role of NKA binding to AnkB in cardiomyocytes, we synthesized a disruptor peptide (MAB peptide) and its AnkB binding ability was verified by pulldown experiments. As opposed to control, the correlation between NKA and NCX currents was abolished in adult rat ventricular myocytes dialyzed with MAB peptide, as well as in cardiomyocytes from AnkB+/- mice. Disruption of NKA from AnkB (with MAB peptide) increased NCX-sensed cytosolic Na+ concentration, reduced Ca2+ extrusion through NCX, and increased frequency of Ca2+ sparks and Ca2+ waves without concomitant increase in Ca2+ transient amplitude or SR Ca2+ load, suggesting an effect in local Ca2+ domains. Selective inhibition of the NKAα2 isoform abolished both the correlation between NKA and NCX currents and the increased rate of Ca2+ sparks and waves following NKA/AnkB disruption, suggesting that an AnkB/NKAα2/NCX domain controls Ca2+ fluxes in cardiomyocytes.

CONCLUSION

NKA binding to AnkB allows ion regulation in a local domain, and acute disruption of the NKA/AnkB interaction using disruptor peptides lead to increased rate of Ca2+ sparks and waves. The functional effects were mediated through the NKAα2 isoform. Disruption of the AnkB/NKA/NCX domain could be an important pathophysiological mechanism in the AnkB syndrome.

IMMPACT-recommended outcome measures and tools of assessment in burning mouth syndrome RCTs: an international Delphi survey protocol

Background

A core outcome set (COS) represents the agreed minimum set of domains and measurement instruments that should be measured and reported in any clinical trial for a given condition. In BMS randomized controlled trials (RCTs), the outcomes identified in the existing literature regarding the efficacy of therapeutic interventions are numerous and diverse. Although the standardized IMMPACT core outcome domains has been developed for measurement of outcomes in chronic pain RCTs, no BMS-specific COS have been adopted and validated. With the evolving landscape of BMS management end points and the development of new therapies, a consensus on a COS for use in future BMS trials is paramount to reduce heterogeneity in outcome reporting. The aim of this study was to reach a consensus for adopting the standardized Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) outcome domains, and their tools of assessment, for burning mouth syndrome (BMS) clinical trials and clinical practice.

Methods

A BMS-specific COS will be developed using the method recommended by the Core Outcome Measures in Effective Trials (COMET) initiative (Registration: http://www.comet-initiative.org/studies/details/1357). Selection of questionnaire outcome measures was informed by the IMMPACT consensus and previous systematic review of RCTs in BMS conducted by the consortium. An international group of clinicians and researchers will be invited to participate in several rounds of a Delphi survey. A consensus meeting will be held with the objective of ratifying the outcomes for inclusion in the COS. A finalized COS explanatory document will be drafted, including all outcomes and measurements as determined by the Delphi rounds and consensus meeting.

Discussion

A COS for the management of BMS will improve the quality of future RCTs, reduce outcome reporting heterogeneity, and facilitate more vigorous data synthesis of management interventions for systematic reviews and meta-analysis. This would ensure enhanced quality evidence for clinical management of the condition.

Syndecan-4-/- Mice Have Smaller Muscle Fibers, Increased Akt/mTOR/S6K1 and Notch/HES-1 Pathways, and Alterations in Extracellular Matrix Components

Background

Extracellular matrix (ECM) remodeling is essential for skeletal muscle development and adaption in response to environmental cues such as exercise and injury. The cell surface proteoglycan syndecan-4 has been reported to be essential for muscle differentiation, but few molecular mechanisms are known. Syndecan-4^–/– mice are unable to regenerate damaged muscle, and display deficient satellite cell activation, proliferation, and differentiation. A reduced myofiber basal lamina has also been reported in syndecan-4^–/– muscle, indicating possible defects in ECM production. To get a better understanding of the underlying molecular mechanisms, we have here investigated the effects of syndecan-4 genetic ablation on molecules involved in ECM remodeling and muscle growth, both under steady state conditions and in response to exercise.

Methods

Tibialis anterior (TA) muscles from sedentary and exercised syndecan-4^–/– and WT mice were analyzed by immunohistochemistry, real-time PCR and western blotting.

Results

Compared to WT, we found that syndecan-4^–/– mice had reduced body weight, reduced muscle weight, muscle fibers with a smaller cross-sectional area, and reduced expression of myogenic regulatory transcription factors. Sedentary syndecan-4^–/– had also increased mRNA levels of syndecan-2, decorin, collagens, fibromodulin, biglycan, and LOX. Some of these latter ECM components were reduced at protein level, suggesting them to be more susceptible to degradation or less efficiently translated when syndecan-4 is absent. At the protein level, TRPC7 was reduced, whereas activation of the Akt/mTOR/S6K1 and Notch/HES-1 pathways were increased. Finally, although exercise induced upregulation of several of these components in WT, a further upregulation of these molecules was not observed in exercised syndecan-4^–/– mice.

Conclusion

Altogether our data suggest an important role of syndecan-4 in muscle development.

The cardiac syndecan-4 interactome reveals a role for syndecan-4 in nuclear translocation of muscle LIM protein (MLP)

Costameres are signaling hubs at the sarcolemma and important contact points between the extracellular matrix and cell interior, sensing and transducing biomechanical signals into a cellular response. The transmembrane proteoglycan syndecan-4 localizes to these attachment points and has been shown to be important in the initial stages of cardiac remodeling, but its mechanistic function in the heart remains insufficiently understood. Here, we sought to map the cardiac interactome of syndecan-4 to better understand its function and downstream signaling mechanisms. By combining two different affinity purification methods with MS analysis, we found that the cardiac syndecan-4 interactome consists of 21 novel and 29 previously described interaction partners. Nine of the novel partners were further validated to bind syndecan-4 in HEK293 cells (i.e. CAVIN1/PTRF, CCT5, CDK9, EIF2S1, EIF4B, MPP7, PARVB, PFKM, and RASIP). We also found that 19 of the 50 interactome partners bind differently to syndecan-4 in the left ventricle lysate from aortic-banded heart failure (ABHF) rats compared with SHAM-operated animals. One of these partners was the well-known mechanotransducer muscle LIM protein (MLP), which showed direct and increased binding to syndecan-4 in ABHF. Nuclear translocation is important in MLP-mediated signaling, and we found less MLP in the nuclear-enriched fractions from syndecan-4^-/- mouse left ventricles but increased nuclear MLP when syndecan-4 was overexpressed in a cardiomyocyte cell line. In the presence of a cell-permeable syndecan-4-MLP disruptor peptide, the nuclear MLP level was reduced. These findings suggest that syndecan-4 mediates nuclear translocation of MLP in the heart.

Rapid Communication: 16S ribosomal ribonucleic acid characterization of liver abscesses in feedlot cattle from three states in the United States

Liver abscesses are a major economic burden to beef producers. Although a few causative organisms have been cultured from purulent material, the full polymicrobial diversity of liver abscesses has not been reported. The objective of this study was to characterize purulent material collected from liver abscess in beef cattle produced in different production systems in 3 cattle producing states in the United States using 16S rRNA gene sequencing. Differences between purulent material microbial communities among geographic region of feeding and application of a common antimicrobial were also investigated. Cattle included in the study were fed in California (dairy type) and Colorado and Texas (both beef type). Liver abscesses from a cross section of feedlots, geographic areas, and tylosin phosphate-administered groups were collected at harvest; DNA from 34 liver abscess samples was extracted; and the V4 region of the 16S rRNA gene was amplified and sequenced. Sequences were classified into 5 phyla, 13 classes, and 17 orders in the domain Bacteria. The phyla identified included Bacteroidetes (35.2% of reads), Proteobacteria (28.6%), Fusobacteria (18.2%), Firmicutes (12.4%), and Actinobacteria (5.5%). Sequences matching the genera and , which have previously been identified as causative agents in liver abscesses, were both present in the abscess bacterial communities at a relative abundance of 15.1 and 3.2%, respectively, of the overall relative abundance. Furthermore, 3 of the most common phyla were Gram-negative bacteria. An analysis-of-similarities test was conducted on Euclidean distances to assess differences between cattle treated and not treated with tylosin as well as to assess differences between geographic regions. Geographical region and treatment with tylosin did affect the microbiome ( = 0.002 and = 0.026 respectively); however, a more robust sample scheme is needed to explore these differences. To our knowledge, this is the first publication describing the complex community of liver purulent material using next generation sequencing in cattle. These data provide a framework for research on a more targeted approach to liver abscess prevention and treatment.

Mapping the in vitro interactome of cardiac sodium (Na+ )-calcium (Ca2+ ) exchanger 1 (NCX1)

The sodium (Na⁺ )-calcium (Ca²⁺ ) exchanger 1 (NCX1) is an antiporter membrane protein encoded by the SLC8A1 gene. In the heart, it maintains cytosolic Ca²⁺ homeostasis, serving as the primary mechanism for Ca²⁺ extrusion during relaxation. Dysregulation of NCX1 is observed in end-stage human heart failure. In this study, we used affinity purification coupled with MS in rat left ventricle lysates to identify novel NCX1 interacting proteins in the heart. Two screens were conducted using: (1) anti-NCX1 against endogenous NCX1 and (2) anti-His (where His is histidine) with His-trigger factor-NCX1_cyt recombinant protein as bait. The respective methods identified 112 and 350 protein partners, of which several were known NCX1 partners from the literature, and 29 occurred in both screens. Ten novel protein partners (DYRK1A, PPP2R2A, SNTB1, DMD, RABGGTA, DNAJB4, BAG3, PDE3A, POPDC2, STK39) were validated for binding to NCX1, and two partners (DYRK1A, SNTB1) increased NCX1 activity when expressed in HEK293 cells. A cardiac NCX1 protein-protein interaction map was constructed. The map was highly connected, containing distinct clusters of proteins with different biological functions, where "cell communication" and "signal transduction" formed the largest clusters. The NCX1 interactome was also significantly enriched with proteins/genes involved in "cardiovascular disease" which can be explored as novel drug targets in future research.

Smoking and Posttraumatic Stress Disorder Symptomatology in Orofacial Pain

To explore the impact of interactions between smoking and symptoms of posttraumatic stress disorder (PTSD) on pain intensity, psychological distress, and pain-related functioning in patients with orofacial pain, a retrospective review was conducted of data obtained during evaluations of 610 new patients with a temporomandibular disorder who also reported a history of a traumatic event. Pain-related outcomes included measures of pain intensity, psychological distress, and pain-related functioning. Main effects of smoking status and PTSD symptom severity on pain-related outcomes were evaluated with linear regression analyses. Further analyses tested interactions between smoking status and PTSD symptom severity on pain-related outcomes. PTSD symptom severity and smoking predicted worse pain-related outcomes. Interaction analyses between PTSD symptom severity and smoking status revealed that smoking attenuated the impact of PTSD symptom severity on affective distress, although this effect was not found at high levels of PTSD symptom severity. No other significant interactions were found, but the present results identifying smoking as an ineffective coping mechanism and the likely role of inaccurate outcome expectancies support the importance of smoking cessation efforts in patients with orofacial pain. Smoking is a maladaptive mechanism for coping with pain that carries significant health- and pain-related risks while failing to fulfill smokers' expectations of affect regulation, particularly among persons with orofacial pain who also have high levels of PTSD symptom severity. Addressing smoking cessation is a critical component of comprehensive treatment. Further research is needed to develop more effective ways to help patients with pain and/or PTSD to replace smoking with more effective coping strategies.

Psychological and Sleep Quality Differences between Chronic Daily Headache and Temporomandibular Disorders Patients

The aim of this study was to investigate whether chronic daily headache (CDH) and temporomandibular disorders (TMD) patients present with different psychological and sleep quality characteristics. Sixty-seven patients diagnosed with CDH, according to classification criteria from Silberstein et al., were matched by age and sex with 67 patients who had a primary diagnosis of myofascial pain (MP) and 67 patients with a primary diagnosis of TMJ intracapsular pain (IC) according to the Research Diagnostic Criteria for TMD. The CDH group was comprised of three mutually exclusive diagnostic groups: chronic migraine ( n = 35); chronic tension-type headache ( n = 26); ‘other CDH’ ( n = 6). All patients completed a battery of psychological and sleep quality questionnaires. All CDH subgroups showed similar psychological and sleep quality profiles. Pain intensity and duration were controlled in the multivariate analyses (MANCOVA) by treating them as covariates. The CDH and MP groups revealed higher levels of psychological distress than the IC group on most psychological domains. The MP group also revealed numerically higher levels of psychological distress in most psychological domains than the CDH group, although these differences were generally not significant. We did not find significant differences between the three groups on post traumatic stress symptoms either. Sleep quality was significantly worse in the MP group than in the CDH and IC groups. These results are discussed in the context of multimodal patient evaluation and treatments that are often necessary for successful clinical management.

Protein Phosphatase 1c Associated with the Cardiac Sodium Calcium Exchanger 1 Regulates Its Activity by Dephosphorylating Serine 68-phosphorylated Phospholemman

The sodium (Na(+))-calcium (Ca(2+)) exchanger 1 (NCX1) is an important regulator of intracellular Ca(2+) homeostasis. Serine 68-phosphorylated phospholemman (pSer-68-PLM) inhibits NCX1 activity. In the context of Na(+)/K(+)-ATPase (NKA) regulation, pSer-68-PLM is dephosphorylated by protein phosphatase 1 (PP1). PP1 also associates with NCX1; however, the molecular basis of this association is unknown. In this study, we aimed to analyze the mechanisms of PP1 targeting to the NCX1-pSer-68-PLM complex and hypothesized that a direct and functional NCX1-PP1 interaction is a prerequisite for pSer-68-PLM dephosphorylation. Using a variety of molecular techniques, we show that PP1 catalytic subunit (PP1c) co-localized, co-fractionated, and co-immunoprecipitated with NCX1 in rat cardiomyocytes, left ventricle lysates, and HEK293 cells. Bioinformatic analysis, immunoprecipitations, mutagenesis, pulldown experiments, and peptide arrays constrained PP1c anchoring to the K(I/V)FF motif in the first Ca(2+) binding domain (CBD) 1 in NCX1. This binding site is also partially in agreement with the extended PP1-binding motif K(V/I)FF-X5-8Φ1Φ2-X8-9-R. The cytosolic loop of NCX1, containing the K(I/V)FF motif, had no effect on PP1 activity in an in vitro assay. Dephosphorylation of pSer-68-PLM in HEK293 cells was not observed when NCX1 was absent, when the K(I/V)FF motif was mutated, or when the PLM- and PP1c-binding sites were separated (mimicking calpain cleavage of NCX1). Co-expression of PLM and NCX1 inhibited NCX1 current (both modes). Moreover, co-expression of PLM with NCX1(F407P) (mutated K(I/V)FF motif) resulted in the current being completely abolished. In conclusion, NCX1 is a substrate-specifying PP1c regulator protein, indirectly regulating NCX1 activity through pSer-68-PLM dephosphorylation.

Trigeminal Inflammatory Compression (TIC) injury induces chronic facial pain and susceptibility to anxiety-related behaviors

Our laboratory previously developed a novel neuropathic and inflammatory facial pain model for mice referred to as the Trigeminal Inflammatory Compression (TIC) model. Rather than inducing whole nerve ischemia and neuronal loss, this injury induces only slight peripheral nerve demyelination triggering long-term mechanical allodynia and cold hypersensitivity on the ipsilateral whisker pad. The aim of the present study is to further characterize the phenotype of the TIC injury model using specific behavioral assays (i.e. light-dark box, open field exploratory activity, and elevated plus maze) to explore pain- and anxiety-like behaviors associated with this model. Our findings determined that the TIC injury produces hypersensitivity 100% of the time after surgery that persists at least 21 weeks post injury (until the animals are euthanized). Three receptive field sensitivity pattern variations in mice with TIC injury are specified. Animals with TIC injury begin displaying anxiety-like behavior in the light-dark box preference and open field exploratory tests at week eight post injury as compared to sham and naïve animals. Panic anxiety-like behavior was shown in the elevated plus maze in mice with TIC injury if the test was preceded with acoustic startle. Thus, in addition to mechanical and cold hypersensitivity, the present study identified significant anxiety-like behaviors in mice with TIC injury resembling the clinical symptomatology and psychosocial impairments of patients with chronic facial pain. Overall, the TIC injury model's chronicity, reproducibility, and reliability in producing pain- and anxiety-like behaviors demonstrate its usefulness as a chronic neuropathic facial pain model.

Syndecan-3 and TFPI colocalize on the surface of endothelial-, smooth muscle-, and cancer cells

Background

Tissue factor (TF) pathway inhibitor (TFPI) exists in two isoforms; TFPIα and TFPIβ. Both isoforms are cell surface attached mainly through glycosylphosphatidylinositol (GPI) anchors. TFPIα has also been proposed to bind other surface molecules, like glycosaminoglycans (GAGs). Cell surface TFPIβ has been shown to exert higher anticoagulant activity than TFPIα, suggesting alternative functions for TFPIα. Further characterization and search for novel TFPI binding partners is crucial to completely understand the biological functions of cell associated TFPI.

Methods and Results

Potential association of TFPI to heparan sulphate (HS) proteoglycans in the syndecan family were evaluated by knock down studies and flow cytometry analysis. Cell surface colocalization was assessed by confocal microscopy, and native PAGE or immunoprecipitation followed by Western blotting was used to test for protein interaction. Heparanase was used to enzymatically degrade cell surface HS GAGs. Anticoagulant potential was evaluated using a factor Xa (FXa) activity assay. Knock down of syndecan-3 in endothelial,- smooth muscle- and breast cancer cells reduced the TFPI surface levels by 20-50%, and an association of TFPIα to syndecan-3 on the cell surface was demonstrated. Western blotting indicated that TFPIα was found in complex with syndecan-3. The TFPI bound to syndecan-3 did not inhibit the FXa generation. Removal of HS GAGs did not release TFPI antigen from the cells.

Conclusions

We demonstrated an association between TFPIα and syndecan-3 in vascular cells and in cancer cells, which did not appear to depend on HS GAGs. No anticoagulant activity was detected for the TFPI associated with syndecan-3, which may indicate coagulation independent functions for this cell associated TFPI pool. This will, however, require further investigation.

Molecular basis of calpain cleavage and inactivation of the sodium-calcium exchanger 1 in heart failure

Cardiac sodium (Na(+))-calcium (Ca(2+)) exchanger 1 (NCX1) is central to the maintenance of normal Ca(2+) homeostasis and contraction. Studies indicate that the Ca(2+)-activated protease calpain cleaves NCX1. We hypothesized that calpain is an important regulator of NCX1 in response to pressure overload and aimed to identify molecular mechanisms and functional consequences of calpain binding and cleavage of NCX1 in the heart. NCX1 full-length protein and a 75-kDa NCX1 fragment along with calpain were up-regulated in aortic stenosis patients and rats with heart failure. Patients with coronary artery disease and sham-operated rats were used as controls. Calpain co-localized, co-fractionated, and co-immunoprecipitated with NCX1 in rat cardiomyocytes and left ventricle lysate. Immunoprecipitations, pull-down experiments, and extensive use of peptide arrays indicated that calpain domain III anchored to the first Ca(2+) binding domain in NCX1, whereas the calpain catalytic region bound to the catenin-like domain in NCX1. The use of bioinformatics, mutational analyses, a substrate competitor peptide, and a specific NCX1-Met(369) antibody identified a novel calpain cleavage site at Met(369). Engineering NCX1-Met(369) into a tobacco etch virus protease cleavage site revealed that specific cleavage at Met(369) inhibited NCX1 activity (both forward and reverse mode). Finally, a short peptide fragment containing the NCX1-Met(369) cleavage site was modeled into the narrow active cleft of human calpain. Inhibition of NCX1 activity, such as we have observed here following calpain-induced NCX1 cleavage, might be beneficial in pathophysiological conditions where increased NCX1 activity contributes to cardiac dysfunction.

β-blockade abolishes the augmented cardiac tPA release induced by transactivation of heterodimerised bradykinin receptor-2 and β2-adrenergic receptor in vivo

Bradykinin (BK) receptor-2 (B2R) and β2-adrenergic receptor (β2AR) have been shown to form heterodimers in vitro. However, in vivo proofs of the functional effects of B2R-β2AR heterodimerisation are missing. Both BK and adrenergic stimulation are known inducers of tPA release. Our goal was to demonstrate the existence of B2R-β2AR heterodimerisation in myocardium and to define its functional effect on cardiac release of tPA in vivo. We further investigated the effects of a non-selective β-blocker on this receptor interplay. To investigate functional effects of B2R-β2AR heterodimerisation (i. e. BK transactivation of β2AR) in vivo, we induced serial electrical stimulation of cardiac sympathetic nerves (SS) in normal pigs that underwent concomitant BK infusion. Both SS and BK alone induced increases in cardiac tPA release. Importantly, despite B2R desensitisation, simultaneous BK infusion and SS (BK+SS) was characterised by 2.3 ± 0.3-fold enhanced tPA release compared to SS alone. When β-blockade (propranolol) was introduced prior to BK+SS, tPA release was inhibited. A persistent B2R-β2AR heterodimer was confirmed in BK-stimulated and non-stimulated left ventricular myocardium by immunoprecipitation studies and under non-reducing gel conditions. All together, these results strongly suggest BK transactivation of β2AR leading to enhanced β2AR-mediated release of tPA. Importantly, non-selective β-blockade inhibits both SS-induced release of tPA and the functional effects of B2R-β2AR heterodimerisation in vivo, which may have important clinical implications.

Chromogranin B in heart failure: a putative cardiac biomarker expressed in the failing myocardium

BACKGROUND

Chromogranin B (CgB) is a member of the granin protein family. Because CgB is often colocalized with chromogranin A (CgA), a recently discovered cardiac biomarker, we hypothesized that CgB is regulated during heart failure (HF) development.

METHODS AND RESULTS

CgB regulation was investigated in patients with chronic HF and in a post-myocardial infarction HF mouse model. Animals were phenotypically characterized by echocardiography and euthanized 1 week after myocardial infarction. CgB mRNA levels were 5.2-fold increased in the noninfarcted part of the left ventricle of HF animals compared with sham-operated animals (P<0.001). CgB mRNA level in HF animals correlated closely with animal lung weight (r=0.74, P=0.04) but not with CgA mRNA levels (r=0.20, P=0.61). CgB protein levels were markedly increased in both the noninfarcted (110%) and the infarcted part of the left ventricle (70%) but unaltered in other tissues investigated. Myocardial CgB immunoreactivity was confined to cardiomyocytes. Norepinephrine, angiotensin II, and transforming growth factor-beta increased CgB gene expression in cardiomyocytes. Circulating CgB levels were increased in HF animals (median levels in HF animals versus sham, 1.23 [interquartile range, 1.03 to 1.93] versus 0.98 [0.90 to 1.04] nmol/L; P=0.003) and in HF patients (HF patients versus control, 1.66 [1.48 to 1.85] versus 1.47 [1.39 to 1.58] nmol/L; P=0.007), with levels increasing in proportion to New York Heart Association functional class (P=0.03 for trend). Circulating CgB levels were only modestly correlated with CgA (r=0.31, P=0.009) and B-type natriuretic peptide levels (r=0.27, P=0.014).

CONCLUSIONS

CgB production is increased and regulated in proportion to disease severity in the left ventricle and circulation during HF development.

Soil carbon sequestration resulting from long-term application of biosolids for land reclamation

Investigations on the impact of application of biosolids for land reclamation on C sequestration in soil were conducted at Fulton County, Illinois, where 41 fields (3.6-66 ha) received biosolids at a cumulative loading rate from 455 to 1654 dry Mg ha(-1) for 8 to 23 yr in rotation from 1972 to 2004. The fields were cropped with corn, wheat, and sorghum and also with soybean and grass or fallowed. Soil organic carbon (SOC) increased rapidly with the application of biosolids, whereas it fluctuated slightly in fertilizer controls. The peak SOC in the 0- to 15-cm depth of biosolids-amended fields ranged from 4 to 7% and was greater at higher rates of biosolids. In fields where biosolids application ceased for 22 yr, SOC was still much higher than the initial levels. Over the 34-yr reclamation, the mean net soil C sequestration was 1.73 (0.54-3.05) Mg C ha(-1) yr(-1) in biosolids-amended fields as compared with -0.07 to 0.17 Mg C ha(-1) yr(-1) in fertilizer controls, demonstrating a high potential of soil C sequestration by the land application of biosolids. Soil C sequestration was significantly correlated with the biosolids application rate, and the equation can be expressed as y = 0.064x - 0.11, in which y is the annual net soil C sequestration (Mg C ha(-1) yr(-1)), and x is annual biosolids application in dry weight (Mg ha(-1) yr(-1)). Our results indicate that biosolids applications can turn Midwest Corn Belt soils from current C-neutral to C-sink. A method for calculating SOC stock under conditions in which surface soil layer depth and mass changes is also described.

AKAP complex regulates Ca2+ re-uptake into heart sarcoplasmic reticulum

The beta-adrenergic receptor/cyclic AMP/protein kinase A (PKA) signalling pathway regulates heart rate and contractility. Here, we identified a supramolecular complex consisting of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2), its negative regulator phospholamban (PLN), the A-kinase anchoring protein AKAP18delta and PKA. We show that AKAP18delta acts as a scaffold that coordinates PKA phosphorylation of PLN and the adrenergic effect on Ca(2+) re-uptake. Inhibition of the compartmentalization of this cAMP signalling complex by specific molecular disruptors interferes with the phosphorylation of PLN. This prevents the subsequent release of PLN from SERCA2, thereby affecting the Ca(2+) re-uptake into the sarcoplasmic reticulum induced by adrenergic stimuli.

Delineation of Type I Protein Kinase A-selective Signaling Events Using an RI Anchoring Disruptor

Control of specificity in cAMP signaling is achieved by A-kinase anchoring proteins (AKAPs), which assemble cAMP effectors such as protein kinase A (PKA) into multiprotein signaling complexes in the cell. AKAPs tether the PKA holoenzymes at subcellular locations to favor the phosphorylation of selected substrates. PKA anchoring is mediated by an amphipathic helix of 14-18 residues on each AKAP that binds to the R subunit dimer of the PKA holoenzymes. Using a combination of bioinformatics and peptide array screening, we have developed a high affinity-binding peptide called RIAD (RI anchoring disruptor) with >1000-fold selectivity for type I PKA over type II PKA. Cell-soluble RIAD selectively uncouples cAMP-mediated inhibition of T cell function and inhibits progesterone synthesis at the mitochondria in steroid-producing cells. This study suggests that these processes are controlled by the type I PKA holoenzyme and that RIAD can be used as a tool to define anchored type I PKA signaling events.

Effect of long-term application of biosolids for land reclamation on surface water chemistry

Biosolids are known to have a potential to restore degraded land, but the long-term impacts of this practice on the environment, including water quality, still need to be evaluated. The surface water chemistry (NO3-, NH4+, and total P, Cd, Cu, and Hg) was monitored for 31 yr from 1972 to 2002 in a 6000-ha watershed at Fulton County, Illinois, where the Metropolitan Water Reclamation District of Greater Chicago was restoring the productivity of strip-mined land using biosolids. The mean cumulative loading rates during the past 31 yr were 875 dry Mg ha(-1) for 1120-ha fields in the biosolids-amended watershed and 4.3 dry Mg ha(-1) for the 670-ha fields in the control watershed. Biosolids were injected into mine spoil fields as liquid fertilizer from 1972 to 1985, and incorporated as dewatered cake from 1980 to 1996 and air-dried solids from 1987 to 2002. The mean annual loadings of nutrients and trace elements from biosolids in 1 ha were 735 kg N, 530 kg P, 4.5 kg Cd, 30.7 kg Cu, and 0.11 kg Hg in the fields of the biosolids-amended watershed, and negligible in the fields of the control watershed. Sampling of surface water was conducted monthly in the 1970s, and three times per year in the 1980s and 1990s. The water samples were collected from 12 reservoirs and 2 creeks receiving drainage from the fields in the control watershed, and 8 reservoirs and 4 creeks associated with the fields in the biosolids-amended watershed for the analysis of NO3- -N (including NO2- N), NH4+-N, and total P, Cd, Cu, and Hg. Compared to the control (0.18 mg L(-1)), surface water NO3- -N in the biosolids-amended watershed (2.23 mg L(-1)) was consistently higher; however, it was still below the Illinois limit of 10 mg L(-1) for public and food-processing water supplies. Biosolids applications had a significant effect on mean concentrations of ammonium N (0.11 mg L(-1) for control and 0.24 mg L(-1) for biosolids) and total P (0.10 mg L(-1) for control and 0.16 mg L(-1) for biosolids) in surface water. Application of biosolids did not increase the concentrations of Cd and Hg in surface water. The elevation of Cu in surface water with biosolids application only occurred in some years of the first decade, when land-applied sludges contained high concentrations of trace metals, including Cu. In fact, following the promulgation of 40 CFR Part 503, the concentrations of all three metals fell below the method detection level (MDL) in surface water for nearly all samplings. Nitrate in the surface water tends to be higher in spring, and ammonium, total P, and total Hg in summer and fall. Mean nitrate, ammonium, and total phosphorus concentrations were found to be greater in creeks than reservoirs. The results indicate that application of biosolids for land reclamation at high loading rates from 1972 to 2002, with adequate runoff and soil erosion control, had only a minor impact on surface water quality.

Physical self-regulation training for the management of temporomandibular disorders

AIMS

To evaluate the long-term effectiveness of a brief skills training program for the management of chronic facial muscle pain. This program of physical self-regulation (PSR) involved primarily training in breathing, postural relaxation, and proprioceptive re-education.

METHODS

Physical self-regulation training was presented by a dentist during two 50-minute sessions spaced at 3-week intervals and was compared to a standard dental care (SDC) program that included a flat-plane intraoral appliance and self-care instructions provided by a dentist. Participants (n = 44) were initially evaluated by a dentist experienced in the diagnosis and management of orofacial pain and were determined to have myofascial pain (Type 1a and 1b diagnoses per the Research Diagnostic Criteria) prior to random assignment to either the PSR or SDC conditions. Posttreatment evaluations 6 weeks and 26 weeks after treatment had begun were conducted by a dentist who was not aware of which treatment the participants received.

RESULTS

Initial results indicated that pain severity and life interference from pain were reduced in both groups (P < 0.001), while perception of control was increased (P < 0.001), as was incisal opening without pain (P < 0.05). At the 26-week follow-up, the PSR group reported less pain (P < 0.04) and greater incisal opening, both with (P < 0.04) and without (P < 0.01) pain, than the SDC group. There were also significant decreases (P < 0.05) in affective distress, somatization, obsessive-compulsive symptoms, tender point sensitivity, awareness of tooth contact, and sleep dysfunction for both groups over time.

CONCLUSION

The findings support the use of PSR for the short- and long-term management of muscle pain in the facial region. These results are discussed in terms of the potential mechanisms by which self-regulation treatment strategies are effective for the management of these pain disorders.

Regulation of anchoring of the RIIα regulatory subunit of PKA to AKAP95 by threonine phosphorylation of RIIα: implications for chromosome dynamics at mitosis

CDK1 phosphorylates the A-kinase regulatory subunit RIIα on threonine 54 (T54) at mitosis, an event proposed to alter the subcellular localization of RIIα. Using an RIIα-deficient leukemic cell line (Reh) and stably transfected Reh cell clones expressing wild-type RIIα or an RIIα(T54E) mutant, we show that RIIα associates with chromatin-bound A-kinase anchoring protein AKAP95 at mitosis and that this interaction involves phosphorylation of RIIα on T54. During interphase, both RIIα and RIIα(T54E) exhibit a centrosome-Golgi localization, whereas AKAP95 is intranuclear. At mitosis and in a mitotic extract, most RIIα, but not RIIα(T54E), co-fractionates with chromatin, onto which it associates with AKAP95. This correlates with T54 phosphorylation of RIIα. Disrupting AKAP95-RIIα anchoring or depleting RIIα from the mitotic extract promotes premature chromatin decondensation. In a nuclear reconstitution assay that mimics mitotic nuclear reformation, RIIα is threonine dephosphorylated and dissociates from AKAP95 prior to assembly of nuclear membranes. Lastly, the Reh cell line exhibits premature chromatin decondensation in vitro, which can be rescued by addition of wild-type RIIα or an RIIα(T54D) mutant, but not RIIα(T54E, A, L or V) mutants. Our results suggest that CDK1-mediated T54 phosphorylation of RIIα constitutes a molecular switch controlling anchoring of RIIα to chromatin-bound AKAP95, where the PKA-AKAP95 complex participates in remodeling chromatin during mitosis.

CDK1-mediated phosphorylation of the RIIα regulatory subunit of PKA works as a molecular switch that promotes dissociation of RIIα from centrosomes at mitosis

Protein kinase A regulatory subunit RIIα is tightly bound to centrosomal structures during interphase through interaction with the A-kinase anchoring protein AKAP450, but dissociates and redistributes from centrosomes at mitosis. The cyclin B-p34cdc2 kinase (CDK1) has been shown to phosphorylate RIIα on T54 and this has been proposed to alter the subcellular localization of RIIα. We have made stable transfectants from an RIIα-deficient leukemia cell line (Reh) that expresses either wild-type or mutant RIIα (RIIα(T54E)). When expressed, RIIα detaches from centrosomes at mitosis and dissociates from its centrosomal location in purified nucleus-centrosome complexes by incubation with CDK1 in vitro. By contrast, centrosomal RIIα(T54E) is not redistributed at mitosis, remains mostly associated with centrosomes during all phases of the cell cycle and cannot be solubilized by CDK1 in vitro. Furthermore, RIIα is solubilized from particular cell fractions and changes affinity for AKAP450 in the presence of CDK1. D and V mutations of T54 also reduce affinity for the N-terminal RII-binding domain of AKAP450, whereas small neutral residues do not change affinity detected by surface plasmon resonance. In addition, only RIIα(T54E) interacts with AKAP450 in a RIPA-soluble extract from mitotic cells. Finally, microtubule repolymerization from mitotic centrosomes of the RIIα(T54E) transfectant is poorer and occurs at a lower frequency than that of RIIα transfectants. Our results suggest that T54 phosphorylation of RIIα by CDK1 might serve to regulate the centrosomal association of PKA during the cell cycle.

Social constraints, cognitive processing, and adjustment to breast cancer

This cross-sectional study of 70 breast cancer survivors examined relationships among social constraints, behavioral and self-report indicators of cognitive processing, depression, and well-being. On the basis of a social-cognitive processing (SCP) model, it was predicted that social constraints would inhibit cognitive processing of the cancer experience, leading to poorer adjustment. Constraints were positively associated with intrusions, avoidance, and linguistic uncertainty in cancer narratives. Greater uncertainty, intrusions, and avoidance, as well as less talking about cancer were associated with greater depression and less well-being. Intrusions partially mediated the positive constraints-depression relationship. Talking about cancer partially mediated the inverse avoidance-well-being relationship. Findings support the SCP model and the importance of using behavioral indicators of cognitive processing to predict positive and negative psychosocial outcomes of cancer.

Binding of PKA-RIIalpha to the Adenovirus E1A12S oncoprotein correlates with its nuclear translocation and an increase in PKA-dependent promoter activity

The adenovirus type 12 (Ad12) E1A12S oncoprotein utilizes the cAMP/protein kinase A (PKA) signal transduction pathway to activate expression of the viral E2 gene, the products of which are essential for viral replication. A central unsolved question is, however, whether E1A12S interacts directly with PKA in the process of promoter activation. We show here that E1A12S binds to the regulatory subunits (R) of PKA in vitro and in vivo. Interaction depends on the N-terminus and the conserved region 1 (CR1) of E1A12S. Both domains are also essential for the activation of viral E2 gene expression. Infection of cells with Ad12 leads to the cellular redistribution of RIIalpha from the cytoplasm into the nucleus. Furthermore, RIIalpha is also located in the nucleus of cells transformed by E1 of Ad12 and transient expression of E1A12S leads to the redistribution of RIIalpha into the nucleus in a N-terminus- and CR1-dependent manner. Cotransfection of E1A12S with RIIalpha results in strong activation of the E2 promoter. Based on these results we conclude that E1A12S functions as a viral A-kinase anchoring protein redistributing RIIalpha from the cytoplasm into the nucleus where it is involved in E1A12S-mediated activation of the E2 promoter.

Posttraumatic growth following breast cancer: a controlled comparison study

Cancer may be viewed as a psychosocial transition with the potential for positive and negative outcomes. This cross-sectional study (a) compared breast cancer (BC) survivors' (n = 70) self-reports of depression, well-being, and posttraumatic growth with those of age- and education-matched healthy comparison women (n = 70) and (b) identified correlates of posttraumatic growth among BC survivors. Groups did not differ in depression or well-being, but the BC group showed a pattern of greater posttraumatic growth, particularly in relating to others, appreciation of life, and spiritual change. BC participants' posttraumatic growth was unrelated to distress or well-being but was positively associated with perceived life-threat, prior talking about breast cancer, income, and time since diagnosis. Research that has focused solely on detection of distress and its correlates may paint an incomplete and potentially misleading picture of adjustment to cancer.

Influence of biased clinician statements on patient report of referred pain

AIMS

The purpose of this study was to examine the influence of clinician bias on patients' reports of referred pain. Diagnosis of temporomandibular disorders is dependent on subjective reports of pain and referred pain upon manual muscle palpation. The influence of biased clinician statements in such subjective reports has not been previously investigated.

METHODS

Forty subjects with pain and who met specific inclusion criteria were randomly assigned to 1 of 2 experimental groups. One group was subjected to a standardized biasing statement, while the other group was not. Tender points in the masseter muscle were then stimulated with a pressure algometer to the pressure-pain threshold. Subjects then recorded the presence or absence, location, intensity, and unpleasantness of any referred pain. State-trait anxiety and social desirability were also assessed to explore the possibility that anxiety levels or subjects' desires to please the experimenter influenced results.

RESULTS

The biased group reported increased presence (P < 0.01), intensity (P < 0.001), and unpleasantness (P < 0.003) of referred pain as compared to the non-biased group. There were no differences between groups on state-trait anxiety or social desirability (P > 0.05).

CONCLUSION

These data suggest that patient reports of pain referral may be subject to clinician bias, and recommendations to control this bias are offered.

Psychosocial profiles of patients with burning mouth syndrome

AIMS

Burning mouth syndrome (BMS) is estimated to affect 1 to 5% of the adult population, with women experiencing symptoms more frequently than men. The purpose of this study was to examine the psychosocial profiles of BMS patients to determine whether psychologic factors are related to pain reports. Based on previous literature, it was hypothesized that patients with BMS would be characterized by clinical elevations on standardized psychologic assessment instruments that included the Revised Symptom Checklist (SCL-90R) and the Multidimensional Pain Inventory (MPI).

METHODS

Thirty-three BMS patients completed the McGill Pain Questionnaire, MPI, and SCL-90R during their initial clinical evaluation session. The SCL-90R and MPI data were then summarized and presented in standardized format (T-scores) to enable meaningful comparisons with larger population samples that included both a chronic pain population and a normal nonclinical sample.

RESULTS

The T-score for the overall pain severity on the MPI was 40.8 (SD 12.8). For the entire BMS sample, there was no evidence for significant clinical elevations on any of the SCL-90R subscales, including depression, anxiety, and somatization. Moreover, patients reported significantly fewer disruptions in normal activities as a result of their oral burning pain than did a large sample of chronic pain patients.

CONCLUSION

These findings indicate that, as a group, this sample of BMS patients did not report significant psychologic distress. There were, however, individual cases (7 of 33, or 21%) where psychometric data indicated a likelihood of psychologic distress, and further evaluation by a competent health professional would be warranted for those individuals.

The role of anger and depression in recurrent headache

Individuals with tension-type headache report significant anger, depression, anxiety, and stressors. However, it is not clear to what extent these variables are interrelated. The objective of the present study was to explore the role of anger in headaches, and to examine its relationship to anxiety, depression, and daily life stressors. Participants were 65 young adult women who suffered from recurrent headaches. The sample was obtained in a large-scale screening of young adult women using the Headache Symptoms List to identify those with recurrent headache. Those individuals reporting headaches completed a battery of assessment measures that included the State-Trait Anger Expression Inventory, the Mood and Anxiety Symptoms Questionnaire, and the Hassles Scale. Results revealed a significant relationship between anger suppression and depression (r = 0.40, P<.01), as well as anger expression and anxiety (r = 0.41, P<.01) for those with headache. The use of the Mood and Anxiety Symptoms Questionnaire allowed for the separate analysis of general distress symptoms and symptoms more specific to anxiety and depression. Results indicated that those with headache experience more general, nonspecific distress rather than symptoms indicative of anxiety and depression (P<.01). In addition, the mixed headache group scored high on both general (mean, 28.96) and specific measures of depression (mean, 65.76) and on anger suppression (mean, 20.12), suggesting that they might experience more psychological distress than those with tension-type headache. The present results indicate the need to distinguish the unique dimensions of anxiety and depression that should be assessed in the population with recurrent headache.

A fission yeast general translation factor reveals links between protein synthesis and cell cycle controls

In two independent screens we isolated fission yeast mutations with phenotypes suggesting defects in B-cyclin function or expression. These mutations define a single gene which we call ded1. We show that ded1 encodes a general translation factor that is related in sequence and function to RNA helicases required for translation in other species. Levels of the B-cyclins Cig2 and Cdc13 are dramatically reduced upon inactivation of Ded1, and this reduction is independent of degradation by the anaphase promoting complex. When a ded1 mutant is grown under semi-restrictive conditions, the translation of Cig2 (and to a lesser extent Cdc13), is impaired relative to other proteins. We show that B-cyclin translation is specifically inhibited upon nitrogen starvation of wild-type cells, when B-cyclin/Cdc2 inactivation is a prerequisite for G(1) arrest and subsequent mating. Our data suggest that translational inhibition of B-cyclin expression represents a third mechanism, in addition to cyclin degradation and Rum1 inhibition, that contributes to Cdc2 inactivation as cells exit from the mitotic cell cycle and prepare for meiosis.

Regulation of the start of DNA replication in Schizosaccharomyces pombe

Cells of Schizosaccharomyces pombe were grown in minimal medium with different nitrogen sources under steady-state conditions, with doubling times ranging from 2.5 to 14 hours. Flow cytometry and fluorescence microscopy confirmed earlier findings that at rapid growth rates, the G1 phase was short and cell separation occurred at the end of S phase. For some nitrogen sources, the growth rate was greatly decreased, the G1 phase occupied 30–50% of the cell cycle, and cell separation occurred in early G1. In contrast, other nitrogen sources supported low growth rates without any significant increase in G1 duration. The method described allows manipulation of the length of G1 and the relative cell cycle position of S phase in wild-type cells. Cell mass was measured by flow cytometry as scattered light and as protein-associated fluorescence. The extensions of G1 were not related to cell mass at entry into S phase. Our data do not support the hypothesis that the cells must reach a certain fixed, critical mass before entry into S. We suggest that cell mass at the G1/S transition point is variable and determined by a set of molecular parameters. In the present experiments, these parameters were influenced by the different nitrogen sources in a way that was independent of the actual growth rate.

The effects of tongue position on mandibular muscle activity

The purpose of this study was to determine the relationship between tongue position and mandibular muscle activity. Thirty-three subjects (28 women) between the ages of 18 and 34 years (mean = 22.1 years) with no prior injury to or pain in the jaw, mouth, or tongue participated in the study. Subjects were asked to rest quietly while baseline electromyographic recordings were made from the temporalis, masseter, and suprahyoid muscle regions. Afterwards, subjects were randomly assigned to conditions requiring them to position the tongue either "against the anterior palate" or "on the floor of the mouth, making sure the tip does not press against any part of the mouth." The results indicated that right temporalis activity was higher when the tongue was positioned against the roof of the mouth than when it was either at baseline or resting on the floor of the mouth (P < .03). A similar pattern of results was observed for the suprahyoid muscle group (P < .01). There were no significant differences in masseter muscle activity as a function of tongue position (Ps > .20). These findings suggest caution in labeling the "rest" position of the tongue and indicate that further study of the relationship between tongue position and orofacial pains in needed.

Measurement of nuclear DNA content in fission yeast by flow cytometry

Cell division cycle (cdc) mutants of Schizosaccharomyces pombe are arrested at specific points in the cell cycle when grown at restrictive temperature. Flow cytometry of such cells reveals an anomalous increase in the DNA fluorescence signal, which represents a problem in experiments designed to determine the cell cycle arrest point. The increased fluorescence signal is due to cytoplasmic constituents and has been attributed to mitochondrial DNA synthesis (S. Sazer and S. W. Sherwood, J. Cell Sci. 97: 509-516, 1990). Here we have studied the cdc10 mutant by flow cytometry using different DNA-binding fluorochromes and found no evidence that the increased fluorescence signal was caused by mitochondrial DNA synthesis. To determine more accurately the nuclear DNA content we have developed a novel method to remove most of the cytoplasmic material by exposing the cells to Triton X-100 and hypotonic conditions after cell wall digestion. The DNA fluorescence from cells treated in this way was more constant with time of incubation at restrictive temperature in spite of a considerable increase in cell size. With this method we could determine that the recently isolated temperature sensitive orp1 mutant is arrested with a 1C DNA content. Premature and abnormal mitosis ('cut') could be observed for the orp1 mutant after only 4 h at restrictive temperature.

Effects of stretch-based progressive relaxation training on the secretion of salivary immunoglobulin A in orofacial pain patients

There is a growing body of evidence that psychologic stressors can affect physical health and proneness to disease through depletion of the body's immune system. Relatively little research, however, has investigated the potential immunoenhancing effect of stress-relieving strategies such as progressive muscle relaxation. This study explored the relationship between immune functioning and relaxation training with persons experiencing persistent facial pain. In a single experimental session, 21 subjects either received relaxation training or rested for an equivalent time period. Salivary immunoglobulin A, mood, pain, and tension levels were measured before and after relaxation and rest periods. Results indicated that a greater proportion of those receiving relaxation training had increases in secretion of salivary immunoglobulin A. These findings suggest that immunoenhancement may be another potential benefit of progressive relaxation training for persons with chronic pain conditions.

Influence of a sympathomimetic amine on masticatory and trapezius pain/pressure thresholds and electromyographic levels

OBJECTIVES

This study examined the influence of terbutaline, a beta-adrenergic sympathomimetic amine on pain/pressure thresholds in the index fingers and masseter and trapezius muscles and electromyographic activity in trapezii.

STUDY DESIGN

In a randomized and double-blind controlled trial, 20 asymptomatic female subjects were assigned to receive either an injection of terbutaline or sterile water before collection of pain/pressure thresholds and electromyographic levels. Repeated analysis of variance and paired t tests were calculated to test for baseline and postinjection differences between groups.

RESULTS

No significant baseline or postinjection group differences in pain/pressure thresholds or electromyographic were detected.

CONCLUSIONS

beta-adrenergic sympathomimetic stimulation does not influence pain/pressure thresholds or electromyographic activity in the masselet and trapezius muscles or pain/pressure thresholds in the index fingers. These results suggest that development of painful muscle conditions is not caused by elevations of sympathetic activity.

The chromosome map of Bacillus thuringiensis subsp. canadensis HD224 is highly similar to that of the Bacillus cereus type strain ATCC 14579

A physical map of the Bacillus thuringiensis subsp. canadensis HD224 chromosome based on AscI, NotI, and SfiI restriction sites has been established. The chromosome map of 4.3 Mb was similar to a revised map of the chromosome of the B. cereus type strain ATCC 14579, except that the B. thuringiensis subsp. canadensis HD224 chromosome lacked a NotI site and had two additional AscI sites. The positions of 27 probes were identical in the common macromap. A probe for the insecticidal toxin gene, cryIA, hybridized only to the B. thuringiensis subsp. canadensis HD224 chromosome. The BssHII ribotype patterns were almost identical confirming the similarity between the two strains.

The psychobiology of hostility: Possible endogenous opioid mechanisms

This study examined the role of endogenous opioids in the relation between hostility and cardiovascular stress responsiveness. Forty-six men completed the Cook-Medley Hostility Scale and experienced a laboratory pain stressor once under opioid blockade and once under placebo. Hostility scores were significantly related to the magnitude of change in cardiovascular reactivity/recovery resulting from opioid blockade. Low scorers on the Cynicism subscale displayed increases in heart rate (HR) reactivity under blockade relative to placebo, with reactivity decreases noted in high scorers. Low Hostile Affect scores were similarly associated with impaired diastolic blood pressure recovery under opioid blockade. HR recovery results were somewhat different, with high scorers on Aggressive Responding and the total Cook-Medley displaying improved HR recovery under opioid blockade, with no change noted in low scorers. These data provide preliminary support for the hypothesis that low hostile individuals rely on endogenous opioids for buffering cardiovascular stress responsiveness, but high hostiles do not.

Relaxation training and opioid inhibition of blood pressure response to stress

The present study was designed to determine the role of endogenous opioid mechanisms in the circulatory effects of relaxation training. Opioid mechanisms were assessed by examination of the effects of opioid receptor blockade with naltrexone on acute cardiovascular reactivity to laboratory stress before and after relaxation training. Thirty-two young men with mildly elevated casual arterial pressure were recruited for placebo-controlled naltrexone stress tests and relaxation training. The results indicated that relaxation training significantly reduced the diastolic pressure response to mental arithmetic stress. Opioid receptor blockade with naltrexone antagonized the effects of relaxation training. These findings suggest that some of the physiological effects of relaxation training are mediated by augmentation of inhibitory opioid mechanisms.

Psychological coping with acute pain: an examination of the role of endogenous opioid mechanisms

This study examined the relationship among endogenous opioids, Monitoring and Blunting coping styles, and acute pain responses. Fifty-eight male subjects underwent a 1-min pressure pain stimulus during two laboratory sessions. Subjects experienced this pain stimulus once under endogenous opioid blockade with naltrexone and once in a placebo condition. Blunting was found to be negatively correlated with pain ratings, but this relationship was significantly more prominent under opioid blockade. Results for coping behaviors subjects used to manage the experimental pain were generally consistent with the Blunting results, indicating that cognitive coping was related more strongly to decreased pain ratings and cardiovascular stress responsiveness under opioid blockade. Overall, the beneficial effects of Blunting and cognitive coping on pain responses did not depend upon endogenous opioids and, in fact, became stronger when opioid receptors were blocked. The relationship between endogenous opioids and coping appears to be dependent upon situational and stimulus characteristics.

Emotional and physiologic responses to laboratory challenges: patients with temporomandibular disorders versus matched control subjects

This study explored psychologic and physiologic factors differentiating patients with temporomandibular disorders (n = 23) from sex-, age-, and weight-matched asymptomatic control subjects. Each subject completed several standard psychologic questionnaires and then underwent two laboratory stressors (mental arithmetic and pressure-pain stimulation). Results indicated that patients with temporomandibular disorders had greater resting respiration rates and reported greater anxiety, sadness, and guilt relative to control subjects. In response to the math stressor, patients with temporomandibular disorders reacted with greater anger than did control subjects. There were no differences between patients with temporomandibular disorders and control subjects on pain measures or any other measured variable for the pressure-pain stimulation trial. In addition, there were no differences in electromyography levels between patients with temporomandibular disorders and control subjects. The results are discussed in terms of their implications for the etiology and treatment of this common and debilitating set of disorders.

Ambulatory electromyogram activity in the upper trapezius region: patients with muscle pain vs. pain-free control subjects

STUDY DESIGN

This study compared the ambulatory electromyogram activity of persons reporting pain in the shoulder and cervical regions with an equal group of persons not reporting such pain. Ambulatory electromyogram data were obtained over 3-day periods. In addition, all participants completed several standard psychological questionnaires.

OBJECTIVES

The results were analyzed with inferential statistics to determine whether subjects reporting significant pain in the shoulder and cervical regions had greater ambulatory electromyogram activity than an equal number of subjects not reporting pain.

SUMMARY OF BACKGROUND DATA

Considerable controversy exists regarding the role of muscle activity in the etiology and maintenance of muscle pain disorders. Given the availability of ambulatory recording devices that can provide a detailed record of muscle activity over an extended period of time, the present research was conducted to determine whether persons reporting shoulder and cervical pain could be differentiated from a group of normal subjects.

METHODS

All subjects (N = 20) completed a battery of tests with standardized psychometric instruments and then were fitted with ambulatory electromyogram monitors to record electromyographic activity of the upper trapezius region of the dominant side; the time, duration, and amplitude of electromyogram activity greater than 2 microV was recorded. The monitors were worn during normal working hours (mean, 6.2 hours per day) over 3 consecutive days. In addition to wearing the monitors, all subjects completed hourly self-ratings of perceived muscle tension during the recording periods.

RESULTS

As expected, subjects with muscle pain reported significantly more pain (mean, 4.9) than did the normal control subjects (mean, 0.9), t(15) = 3.29, P < 0.01. However, patients with muscle pain did not have greater average electromyogram activity (mean, 6.4 microV) over the 3-day period as compared to the normal controls (mean, 7.1 microV), t(18) = -0.25, P < 0.80. Self-monitoring of perceived muscle tension also did not reveal differences between pain subjects and the normal control subjects (P < 0.75).

CONCLUSIONS

Ambulatory measurements of electromyogram activity did not differentiate persons reporting upper trapezius or cervical pain from those that did not report such pain. Persons reporting pain are also not distinguishable from normal control subjects on a variety of self-report measures. These results raise questions regarding the role of ambulatory electromyogram recordings in the evaluation and treatment of muscle pain disorders.

Variable numbers of rRNA gene operons in Bacillus cereus strains

Ribosomal RNA operon organisation was analysed in two Bacillus cereus strains of different chromosome size, ATCC 10987 (5.4 Mb) and F0837/76 (2.4 Mb). We estimated that there were twelve and nine copies of the rRNA operons in these two strains, respectively. In B. cereus ATCC 10987 six rRNA operons were less than 10 kb apart, while in B. cereus F0837/76 four rRNA operons were similarly clustered. The origin of replication was located in the vicinity of a rRNA operon in both strains.