Proteomic Profiling Reveals Specific Molecular Hallmarks of the Pig Claustrum

The present study, employing a comparative proteomic approach, analyzes the protein profile of pig claustrum (CLA), putamen (PU), and insula (IN). Pig brain is an interesting model whose key translational features are its similarities with cortical and subcortical structures of human brain. A greater difference in protein spot expression was observed in CLA vs PU as compared to CLA vs IN. The deregulated proteins identified in CLA resulted to be deeply implicated in neurodegenerative (i.e., sirtuin 2, protein disulfide-isomerase 3, transketolase) and psychiatric (i.e., copine 3 and myelin basic protein) disorders in humans. Metascape analysis of differentially expressed proteins in CLA vs PU comparison suggested activation of the α-synuclein pathway and L1 recycling pathway corroborating the involvement of these anatomical structures in neurodegenerative diseases. The expression of calcium/calmodulin-dependent protein kinase and dihydropyrimidinase like 2, which are linked to these pathways, was validated using western blot analysis. Moreover, the protein data set of CLA vs PU comparison was analyzed by Ingenuity Pathways Analysis to obtain a prediction of most significant canonical pathways, upstream regulators, human diseases, and biological functions. Interestingly, inhibition of presenilin 1 (PSEN1) upstream regulator and activation of endocannabinoid neuronal synapse pathway were observed. In conclusion, this is the first study presenting an extensive proteomic analysis of pig CLA in comparison with adjacent areas, IN and PUT. These results reinforce the common origin of CLA and IN and suggest an interesting involvement of CLA in endocannabinoid circuitry, neurodegenerative, and psychiatric disorders in humans.

Dietary Supplementation with Boswellia serrata, Verbascum thapsus, and Curcuma longa in Show Jumping Horses: Effects on Serum Proteome, Antioxidant Status, and Anti-Inflammatory Gene Expression

Intense exercise can cause inflammation and oxidative stress due to the production of reactive oxygen species. These pathophysiological processes are interdependent, and each one can induce the other, creating a vicious circle. A placebo-controlled blind study was carried out in show jumping horses (n. 16) to evaluate the effects of a commercial dietary supplement (Dolhorse® N.B.F. Lanes srl, Milan, Italy) containing Verbascum thapsus leaf powder (1.42%), Curcuma longa (14.280 mg/kg), and Boswellia serrata (Roxb ex Colebr) (14.280 mg/kg) extracts. Before and after 10 days of dietary supplementation, blood samples were collected to evaluate the protein levels, antioxidants, and inflammatory responses by proteomic analysis or real-time Reverse Transcriptase-Polymerase Chain Reaction (real-time RT-PCR). A total of 36 protein spots, connected to 29 proteins, were modulated by dietary supplementation, whereas real-time RT-PCR revealed a significant downregulation of proinflammatory cytokines (interleukin 1α (p < 0.05) and interleukin-6 (0.005), toll-like receptor 4 (p < 0.05), and IKBKB (p < 0.05) in supplemented sport horses. Immunoglobulin chains, gelsolin, plasminogen, vitamin D binding protein, apolipoprotein AIV, and filamin B were overexpressed, whereas haptoglobin, α-2-HS-glycoprotein, α2-macroglobulin, afamin, amine oxidase, 60S acidic ribosomal protein, and complement fragments 3, 4, and 7 were reduced. No effect was observed on the antioxidant defense systems. The present results suggest this phytotherapy may reinforce the innate immune responses, thus representing a valid adjuvant to alleviate inflammation, which is a pathophysiological process in sport horses.

Parathyroid Carcinoma and Adenoma Co-existing in One Patient: Case Report and Comparative Proteomic Analysis

BACKGROUND/AIM

The lack of specific parathyroid carcinoma (PC) biomarkers in clinical practice points out the importance of analyzing the proteomic signature of this cancer. We performed a comparative proteomic analysis of PC and parathyroid adenoma (PA) co-existing in the same patient.

PATIENTS AND METHODS

PC and PA were taken from a 63-year-old patient. Using two-dimensional differential gel electrophoresis (2D-DIGE) coupled to mass spectrometry we examined the differences between PC and PA proteins. For validation, additional PC and PA samples were obtained from 10 patients. Western blot analysis was used to validate the difference of expression observed with 2D-DIGE analysis. Bioinfomatic analysis was performed using QIAGEN's Ingenuity Pathways Analysis (IPA) to determine the predominant canonical pathways and interaction networks involved.

RESULTS

Thirty-three differentially expressed proteins were identified in PC compared to PA. Among these, ubiquitin C-terminal hydrolase-L1 (UCH-L1) was highly overexpressed in PC. The result was confirmed by Western Blot analysis in additional PC samples.

CONCLUSION

Our comparative proteomic analysis of co-existing neoplasms allowed detecting specific and peculiar differences between PC and PA overcoming population biological variability.

Salivary Proteome Changes in Response to Acute Psychological Stress Due to an Oral Exam Simulation in University Students: Effect of an Olfactory Stimulus

The autonomic nervous system (ANS) plays a crucial role both in acute and chronic psychological stress eliciting changes in many local and systemic physiological and biochemical processes. Salivary secretion is also regulated by ANS. In this study, we explored salivary proteome changes produced in thirty-eight University students by a test stress, which simulated an oral exam. Students underwent a relaxation phase followed by the stress test during which an electrocardiogram was recorded. To evaluate the effect of an olfactory stimulus, half of the students were exposed to a pleasant odor diffused in the room throughout the whole session. Saliva samples were collected after the relaxation phase (T0) and the stress test (T1). State anxiety was also evaluated at T0 and T1. Salivary proteins were separated by two-dimensional electrophoresis, and patterns at different times were compared. Spots differentially expressed were trypsin digested and identified by mass spectrometry. Western blot analysis was used to validate proteomic results. Anxiety scores and heart rate changes indicated that the fake exam induced anxiety. Significant changes of α-amylase, polymeric immunoglobulin receptor (PIGR), and immunoglobulin α chain (IGHA) secretion were observed after the stress test was performed in the two conditions. Moreover, the presence of pleasant odor reduced the acute social stress affecting salivary proteome changes. Therefore, saliva proteomic analysis was a useful approach to evaluate the rapid responses associated to an acute stress test also highlighting known biomarkers.

Putative Biomarkers for Malignant Pleural Mesothelioma Suggested by Proteomic Analysis of Cell Secretome

BACKGROUND

Malignant pleural mesothelioma (MPM) a rare neoplasm linked to asbestos exposure is characterized by a poor prognosis. Soluble mesothelin is currently considered the most specific diagnostic biomarker. The aim of the study was to identify novel biomarkers by proteomic analysis of two MPM cell lines secretome.

MATERIALS AND METHODS

The protein patterns of MPM cells secretome were examined and compared to a non-malignant mesothelial cell line using two-dimensional gel electrophoresis coupled to mass spectrometry. Serum levels of candidate biomarkers were determined in MPM patients and control subjects.

RESULTS

Two up-regulated proteins involved in cancer biology, prosaposin and quiescin Q6 sulfhydryl oxidase 1, were considered candidate biomarkers. Serum levels of both proteins were significantly higher in MPM patients than control subjects. Combining the data of each receiver-operating characteristic analysis predicted a good diagnostic accuracy.

CONCLUSION

A panel of the putative biomarkers represents a promising tool for MPM diagnosis.

Proteomic Investigation of Malignant Major Salivary Gland Tumors

The purpose of this study was to define the proteome profile of fine needle aspiration (FNA) samples of malignant major salivary gland tumors (MSGT) compared to benign counterparts, and to evaluate potential clinical correlations and future applications. Patients affected by MSGT (n = 20), pleomorphic adenoma (PA) (n = 37) and Warthin's tumor (WT) (n = 14) were enrolled. Demographic, clinical and histopathological data were registered for all patients. FNA samples were processed to obtain the protein extracts. Protein separation was obtained by two-dimensional electrophoresis (2-DE) and proteins were identified by mass spectrometry. Western blot analysis was performed to validate the 2-DE results. Statistical differences between groups were calculated by the Mann-Whitney U test for non-normal data. Spearman's rank correlation coefficient was calculated to evaluate correlations among suggested protein biomarkers and clinical parameters. Twelve and 27 differentially expressed spots were found for MSGT versus PA and MSGT versus WT, respectively. Among these, annexin-5, cofilin-1, peptidyl-prolyl-cis-trans-isomerase-A and F-actin-capping-alpha-1 were able to differentiate MSGT from PA, WT, and healthy samples. Moreover, STRING analysis suggested cofilin-1 as a key node of protein interactions. Some of the overexpressed proteins are related to some clinical factors of our cohort, such as survival and outcome. Our results suggest potential protein biomarkers of MSGT, which could allow for more appropriate treatment plans, as well as shedding light on the molecular pathways involved.

Brain mitochondrial proteome alteration driven by creatine deficiency suggests novel therapeutic venues for creatine deficiency syndromes

Creatine (Cr) is a small metabolite with a central role in energy metabolism and mitochondrial function. Creatine deficiency syndromes are inborn errors of Cr metabolism causing Cr depletion in all body tissues and particularly in the nervous system. Patient symptoms involve intellectual disability, language and behavioral disturbances, seizures and movement disorders suggesting that brain cells are particularly sensitive to Cr depletion. Cr deficiency was found to affect metabolic activity and structural abnormalities of mitochondrial organelles; however a detailed analysis of molecular mechanisms linking Cr deficit, energy metabolism alterations and brain dysfunction is still missing. Using a proteomic approach we evaluated the proteome changes of the brain mitochondrial fraction induced by the deletion of the Cr transporter (CrT) in developing mutant mice. We found a marked alteration of the mitochondrial proteomic landscape in the brain of CrT deficient mice, with the overexpression of many proteins involved in energy metabolism and response to oxidative stress. Moreover, our data suggest possible abnormalities of dendritic spines, synaptic function and plasticity, network excitability and neuroinflammatory response. Intriguingly, the alterations occurred in coincidence with the developmental onset of neurological symptoms. Thus, cerebral mitochondrial alterations could represent an early response to Cr deficiency that could be targeted for therapeutic intervention.

A Proteomic Approach to Uncover Neuroprotective Mechanisms of Oleocanthal against Oxidative Stress

Neurodegenerative diseases represent a heterogeneous group of disorders that share common features like abnormal protein aggregation, perturbed Ca2+ homeostasis, excitotoxicity, impairment of mitochondrial functions, apoptosis, inflammation, and oxidative stress. Despite recent advances in the research of biomarkers, early diagnosis, and pharmacotherapy, there are no treatments that can halt the progression of these age-associated neurodegenerative diseases. Numerous epidemiological studies indicate that long-term intake of a Mediterranean diet, characterized by a high consumption of extra virgin olive oil, correlates with better cognition in aged populations. Olive oil phenolic compounds have been demonstrated to have different biological activities like antioxidant, antithrombotic, and anti-inflammatory activities. Oleocanthal, a phenolic component of extra virgin olive oil, is getting more and more scientific attention due to its interesting biological activities. The aim of this research was to characterize the neuroprotective effects of oleocanthal against H₂O₂-induced oxidative stress in neuron-like SH-SY5Y cells. Moreover, protein expression profiling, combined with pathways analyses, was used to investigate the molecular events related to the protective effects. Oleocanthal was demonstrated to counteract oxidative stress, increasing cell viability, reducing reactive oxygen species (ROS) production, and increasing reduced glutathione (GSH) intracellular level. Proteomic analysis revealed that oleocanthal significantly modulates 19 proteins in the presence of H₂O₂. In particular, oleocanthal up-regulated proteins related to the proteasome, the chaperone heat shock protein 90, the glycolytic enzyme pyruvate kinase, and the antioxidant enzyme peroxiredoxin 1. Moreover, oleocanthal protection seems to be mediated by Akt activation. These data offer new insights into the molecular mechanisms behind oleocanthal protection against oxidative stress.

Putative salivary biomarkers useful to differentiate patients with fibromyalgia

Fibromyalgia (FM) is a chronic pain disorder characterized by widespread pain and associated with unspecific symptoms. So far, no laboratory tests have been validated. The aim of the present study was to investigate the presence in saliva of potential diagnostic and/or prognostic biomarkers which could be useful for the management of FM patients. Specifically, the salivary profile of FM patients was compared with those of healthy subjects, subjects suffering migraine (model of non-inflammatory chronic pain), and patients affected by rheumatoid arthritis (model of inflammatory chronic pain). For proteomics analysis 2-DE and SELDI-TOF-MS were applied. From 2-DE serotransferrin and alpha-enolase were found differentially expressed in FM. Hence, their expression was validated by ELISA together with phosphoglycerate-mutase-I and transaldolase, which were found in a previous work. Moreover, ROC curve was calculated by comparing FM patients versus control subjects (healthy plus migraine) to investigate the discriminative power of biomarkers. The best performance was obtained by combining alpha-enolase, phosphoglycerate-mutase-I and serotransferrin. On the other hand, none of the candidate proteins showed a statistical correlation with clinical features. Finally, preliminary SELDI analysis highlighted two peaks whose identification need to be validated. Overall, these results could be useful in supporting the clinical diagnosis of FM. SIGNIFICANCE: FM is one of the most common chronic pain condition which is associated with significant disability. The fibromyalgic pain is a peculiar characteristic of this disease and FM patients suffer from reduced quality of life, daily functioning and productivity. Considering the deep complexity of FM, the discovery of more objective markers is crucial for supporting clinical diagnosis. Therefore, the aim of the present study was the selection of biomarkers effectively associated with fibromyalgic pain which will enable clinicians to achieve an unambiguous diagnosis, and to improve approaches to patients' management. We defined a panel of 3 salivary proteins which could be one of the criteria to be taken into account. Consequently, the identification of disease salivary biomarkers could be helpful in detecting FM clusters and targeted treatment. Actually, our future perspective foresees to develop a simple, rapid and not invasive point-of-care testing which will be of use during the diagnostic process. In addition, the present results can offer a clue for shedding light upon the complex entity of such a disease like FM.

Proteomic analysis of fine-needle aspiration in differential diagnosis of thyroid nodules

Thyroid nodules are common in the general population and vary widely in their propensity to harbor thyroid malignancies. The category of follicular lesion of undetermined significance, for instance, carries only a 15% risk of malignancy. The overarching aim of this work was the proteomic study of thyroid cancer because more effort needs to be placed on differentiating malignant thyroid nodules to avoid unnecessary thyroidectomy. We used 2-dimensional electrophoresis coupled to nano-liquid chromatography electrospray ionization tandem mass spectrometry, to examine fine-needle aspiration (FNA), which was easily attainable from the wash of the syringe used for classical FNA biopsy. Overall, we found 25 different proteins able to discriminate benign from malignant samples. The different expression of moesin; annexin A1 (ANXA1); cornulin (CRNN); lactate dehydrogenase; enolase; protein DJ-1; and superoxide dismutase was confirmed in FNA by enzyme-linked immunosorbent assay or Western blot. Receiver operating characteristic curves were calculated to investigate the discriminative power of our marker. The best performance in diagnosis was obtained by combining ANXA1, enolase, protein DJ-1, superoxide dismutase, and CRNN. In addition, the most highly ranked proteins, from the perspective of follicular lesion of undetermined significance, were ANXA1 and CRNN. The research of these candidate biomarkers has then been widened to other biological fluids, such as serum and whole saliva. In conclusion, we believe that when a decision by a thyroid nodule biopsy cannot be distinctly made, the combination of our biomarkers may be one of the criteria to be taken into account for the final decision, together with the identification of ANXA1 in serum and saliva.

Salivary psoriasin (S100A7) correlates with diffusion capacity of carbon monoxide in a large cohort of systemic sclerosis patients

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune disease characterized by progressive fibrosis of the skin and the internal organs. In a previous work we suggested a correlation between levels of salivary psoriasin (S100A7) and pulmonary involvement in SSc patients. The goals of this study are to determine the distribution characteristics of psoriasin in whole saliva (WS) of SSc and healthy donor populations and define its predictive value on diffusion capacity of carbon monoxide (DLCO), along with others clinical parameters.

METHODS

Salivary level of psoriasin was determined by ELISA kit in 134 SSc patients, 63 Raynaud syndrome patients, 40 patients affected by other connective diseases (non-case) and 74 healthy control subjects.

RESULTS

A significant increase of salivary psoriasin was observed in SSc patients when compared with other healthy and pathological controls. Moreover, we confirmed the efficacy of salivary psoriasin to correlate with DLCO in a large cohort of SSc patients.

CONCLUSIONS

Overall our results suggest a rapid, non invasive and low costing method which can help clinicians in the evaluation of SSc pulmonary involvement.

Design, Synthesis, and Biological Evaluation of Imidazo[1,5-a]quinoline as Highly Potent Ligands of Central Benzodiazepine Receptors

A series of imidazo[1,5-a]quinoline derivatives was designed and synthesized as central benzodiazepine receptor (CBR) ligands. Most of the compounds showed high CBR affinity with Ki values within the submicromolar and subnanomolar ranges with interesting modulations in their structure-affinity relationships. In particular, fluoroderivative 7w (Ki = 0.44 nM) resulted in the most potent ligand among the imidazo[1,5-a]quinoline derivatives described so far. Overall, these observations confirmed the assumption concerning the presence of a large though apparently saturable lipophilic pocket in the CBR binding site region interacting with positions 4 and 5 of the imidazo[1,5-a]quinoline nucleus. The in vivo biological characterization revealed that compounds 7a,c,d,l,m,q,r,w show anxiolytic and antiamnestic activities without the unpleasant myorelaxant side effects of the classical 1,4-BDZ. Furthermore, the effect of 7l,q,r, and 8i in lowering lactate dehydrogenase (LDH) release induced by ischemia-like conditions in rat brain slices suggested neuroprotective properties for these imidazo[1,5-a]quinoline derivatives.

Comparative proteomic analysis of malignant pleural mesothelioma: Focusing on the biphasic subtype

Malignant pleural mesothelioma (MPM) is a rare cancer originated from pleural mesothelial cells. MPM has been associated with long-term exposure to asbestos. In this work we performed a comparative proteomic analysis of biphasic pleural mesothelioma (B-PM). Tissue biopsies were obtained from 61 patients who were subjected to a diagnostic thoracoscopy. 2D/MS based approach was used for proteomic analysis. The 22 proteins found differentially expressed in B-PM, with respect to benign, were analyzed by Ingenuity Pathways Analysis and compared with those obtained for epitheliod pleural mesothelioma (E-PM). A different activation of transcription factors, proteins and cytokines were observed between two subtypes.

Glucagon-like peptide 1 protects INS-1E mitochondria against palmitate-mediated beta-cell dysfunction: a proteomic study

Proteomic analysis of the protein expression profiles of enriched mitochondrial preparations of rat INS-1E β cells treated with palmitate in the presence and in the absence of GLP-1.

Altered protease-activated receptor-1 expression and signaling in a malignant pleural mesothelioma cell line, NCI-H28, with homozygous deletion of the β-catenin gene

Protease activated receptors (PARs) are G-protein coupled receptors that are activated by an unique proteolytic mechanism. These receptors play crucial roles in hemostasis and thrombosis but also in inflammation and vascular development. PARs have also been implicated in tumor progression, invasion and metastasis. In this study, we investigated expression and signaling of PAR1 in nonmalignant pleural mesothelial (Met-5A) and malignant pleural mesothelioma (NCI-H28) cells. We found that the expression level of PAR1 was markedly higher in NCI-H28 cells compared to Met-5A and human primary mesothelial cells. Other three malignant pleural mesothelioma cell lines, i.e. REN, Ist-Mes2, and Mero-14, did not show any significant PAR1 over-expression compared to Met-5A cell line. Thrombin and PAR1 activating peptides enhanced Met-5A and NCI-H28 cell proliferation but in NCI-H28 cells higher thrombin concentrations were required to obtain the same proliferation increase. Similarly, thrombin caused extracellular signal-regulated kinase 1/2 activation in both cell lines but NCI-H28 cells responded at higher agonist concentrations. We also determined that PAR1 signaling through Gq and G12/13 proteins is severely altered in NCI-H28 cells compared to Met-5A cells. On the contrary, PAR1 signaling through Gi proteins was persistently maintained in NCI-H28 cells. Furthermore, we demonstrated a reduction of cell surface PAR1 expression in NCI-H28 and malignant pleural mesothelioma REN cells. Thus, our results provide evidences for dysfunctional PAR1 signaling in NCI-H28 cells together with reduced plasma membrane localization. The role of PAR1 in mesothelioma progression is just emerging and our observations can promote further investigations focused on this G-protein coupled receptor.

First evidence of TRPV5 and TRPV6 channels in human parathyroid glands: possible involvement in neoplastic transformation

The parathyroid glands play an overall regulatory role in the systemic calcium (Ca²⁺) homeostasis. The purpose of the present study was to demonstrate the presence of the Ca²⁺ channels transient receptor potential vanilloid (TRPV) 5 and TRPV6 in human parathyroid glands. Semi-quantitative and quantitative PCR was carried out to evaluate the presence of TRPV5 and TRPV6 mRNAs in sporadic parathyroid adenomas and normal parathyroid glands. Western blot and immunocytochemical assays were used to assess protein expression, cellular localization and time expression in primary cultures from human parathyroid adenoma. TRPV5 and TRPV6 transcripts were then identified both in normal and pathological tissues. Predominant immunoreactive bands were detected at 75–80 kD for both vanilloid channels. These channels co-localized with the calcium-sensing receptor (CASR) on the membrane surface, but immunoreactivity was also detected in the cytosol and around the nuclei. Our data showed that western blotting recorded an increase of protein expression of both channels in adenoma samples compared with normal glands suggesting a potential relation with the cell calcium signalling pathway and the pathological processes of these glands.

Comparative proteomic analysis of malignant pleural mesothelioma evidences an altered expression of nuclear lamin and filament-related proteins

PURPOSE

Malignant mesothelioma is a neoplastic disease linked to asbestos exposure whose diagnosis is limited, so detection methods for an early diagnosis and treatment result essential. Here, we compared proteomic profiles of malignant pleural mesothelioma (MPM) and benign biopsies to search potential biomarkers useful in differential diagnosis.

EXPERIMENTAL DESIGN

Tissue biopsies were obtained from 53 patients who were subjected to a diagnostic thoracoscopy. 2DE/MS based approach was used for proteomic analysis and protein validation was carried out by Western blot analysis versus benign and lung carcinoma samples.

RESULTS

Among the proteins identified we confirmed known MPM biomarkers such as calretinin and suggested the new ones as prelamin A/C, desmin, vimentin, calretinin, fructose-bisphosphate aldolase A, myosin regulatory light chain 2, ventricular/cardiac muscle isoform, myosin light chain 3 and myosin light chain 6B. Ingenuity software was used to identify the biological processes to which these proteins belong and to construct a potential network.

CONCLUSIONS AND CLINICAL RELEVANCE

Overall, our results suggest potential biomarkers that can be useful in occupational medicine for the early identification of the onset of disease in health surveillance of past asbestos-exposed workers, for monitoring the progress of disease and for assessing the response to treatment.

Search for peripheral biomarkers in patients affected by acutely psychotic bipolar disorder: a proteomic approach

Data on neurobiological mechanisms underlying mood disorders are elusive; the aetiology of such states is multifactorial, including genetic predisposition and environmental factors. Diagnosis is currently being made only on an interview-based methodology. Biological markers, which could improve the current classification, and in perspective, stratify patients on a biological basis into more homogeneous clinically distinct subgroups, are highly needed. We describe here a comparative proteomic analysis of peripheral lymphocytes from patients affected by acute psychotic bipolar disorder (PBD) (n = 15), major depressive episode (MDE) with no personal or family history of psychosis (n = 11), and a group of demographically matched healthy controls (HC) (n = 15). All patients were evaluated by means of Structured Clinical Interview for DSM-IV-Patient version (SCID-I-P), Positive and Negative Symptoms Scale (PANSS), Young Mania Rating Scale (YMRS), Hamilton Anxiety Rating Scale (HAM-A) and Hamilton Depression Rating Scale (HAM-D-17) questionnaires. Blood lymphocytes were obtained by gradient separation, and 2-DE was carried out on protein extracts. Significant differences in protein patterns among the three groups were observed. Thirty-six protein spots were found to be differentially expressed in patients compared to controls, which collapsed into 25 different proteins after mass spectrometry identification. Twenty-one of these proteins failed to discriminate between PBD and MDE, suggesting common signatures for these disorders. Nevertheless, after the western blot validation only two of the remaining proteins, namely LIM and SH3 domain protein1, and short-chain specific acyl-CoA dehydrogenase mitochondrial protein, resulted in being significantly upregulated in PBD samples suggesting additional mechanisms that could be associated with the psychotic features of bipolar disorder.

A multidisciplinary approach to study the effects of balneotherapy and mud-bath therapy treatments on fibromyalgia

OBJECTIVES

To study the effects of both balneotherapy and mud-bath therapy treatments in patients affected by primary fibromyalgia (FM) using rheumatological, psychiatric, biochemical and proteomic approaches.

METHODS

Forty-one FM patients (39 females, 2 males), who fulfilled the American College of Rheumatology criteria received a 2-week thermal therapy programme consisting of therapy once daily for 6 days/week. Twenty-one patients received mud-bath treatment, while the other twenty balneotherapy. Pain, symptoms, and quality of life were assessed. Oxytocin, brain-derived neurotrophic factor (BDNF), ATP and serotonin transporter levels during therapy were assayed. Comparative whole saliva (WS) proteomic analysis was performed using a combination of two-dimensional electrophoresis (2DE) and mass spectrometry techniques.

RESULTS

We observed a reduction in pain, FIQ values and improvement of SF36 in both groups of patients treated with mud-bath or balneotherapy. The improvement of the outcome measures occurred with different timing and duration in the two spa treatments. A significant decrease in BDNF concentrations was observed either after balneotherapy or mud-bath therapy when assayed after twelve weeks, while no significant change in oxytocin levels, ATP levels and serotonin transporter were detected. Significant differences were observed for phosphoglycerate mutase1 (PGAM1) and zinc alpha-2-glycoprotein 1 (AZGP1) protein expression.

CONCLUSIONS

Our results showed that the thermal treatment might have a beneficial effect on the specific symptoms of the disease. In particular, while balneotherapy gives results that in most patients occur after the end of the treatment but which are no longer noticeable after 3 months, the mud-bath treatment gives longer lasting results.

The expression of platelet serotonin transporter (SERT) in human obesity

Background

Serotonin (5-HT) is a well-known modulator of eating behavior. However, the molecular mechanisms linking its action to body weight balance have been only partially elucidated. Since platelets are a suitable peripheral model to study 5-HT transport, metabolism and release, we herein evaluated the expression of the platelet 5-HT re-uptake system (SERT) by [³H]-paroxetine binding assay. A cohort of 114 unrelated individuals (34 males, 80 females; age, mean ± SD: 38.57 ± 12.47 years) without major psychiatric disorders, was recruited following a naturalistic design regarding age or gender and classified accordingly to their body mass index (BMI). Subjects were divided into 5 groups: normal-weight (NW), overweight (OW) and grade I-III obese (OB) individuals. For gender analyses, data were transformed into [³H]-paroxetine density (B_max)/BMI ratios to overcome both the disparity of women vs. men number and anthropometric differences between sexes.

Results

[³H]-paroxetine B_max (SERT density, fmol/mg proteins) was reduced in platelet membranes of grade II (p < 0.01) and III (p < 0.001) obese subjects vs. controls and in overweight subjects (p < 0.05) vs. grade III obese individuals. Considering all patients together, a strong negative correlation between B_max and BMI (r = −0.449; P < 0.0001) was demonstrated. Conversely, [³H]-paroxetine K_D (dissociation constant, nM) did not differ among groups. No gender-related variation concerning B_max/BMI ratios was observed in this cohort of subjects.

Conclusions

The down-regulation of SERT in platelet membranes of severe human obesity (BMI > 35 Kg/m²) confirms the involvement of 5-HT system in body weight gain. Moreover, this findings may help to elucidate those monoamine-endocrine networks acting on fat storage, adipocyte signaling and energy balance. Targeting 5-HT/5-HT-related markers will possibly uncover the existence of human obesity subtypes.

A multidisciplinary approach to study a couple of monozygotic twins discordant for the chronic fatigue syndrome: a focus on potential salivary biomarkers

BACKGROUND

Chronic Fatigue Syndrome (CFS) is a severe, systemic illness characterized by persistent, debilitating and medically unexplained fatigue. The etiology and pathophysiology of CFS remains obscure, and diagnosis is formulated through the patient's history and exclusion of other medical causes. Thereby, the availability of biomarkers for CFS could be useful for clinical research. In the present study, we used a proteomic approach to evaluate the global changes in the salivary profile in a couple of monozygotic twins who were discordant for CFS. The aim was to evaluate differences of salivary protein expression in the CFS patient in respect to his healthy twin.

METHODS

Saliva samples were submitted to two-dimensional electrophoresis (2DE). The gels were stained with Sypro, and a comparison between CFS subject and the healthy one was performed by the software Progenesis Same Spot including the Analysis of variance (ANOVA test). The proteins spot found with a ≥2-fold spot quantity change and p<0.05 were identified by Nano-liquid chromatography electrospray ionization tandem mass spectrometry. To validate the expression changes found with 2DE of 5 proteins (14-3-3 protein zeta/delta, cyclophilin A, Cystatin-C, Protein S100-A7, and zinc-alpha-2-glycoprotein), we used the western blot analysis. Moreover, proteins differentially expressed were functionally analyzed using the Ingenuity Pathways Analysis software with the aim to determine the predominant canonical pathways and the interaction network involved.

RESULTS

The analysis of the protein profiles allowed us to find 13 proteins with a different expression in CFS in respect to control. Nine spots were up-regulated in CFS and 4 down-regulated. These proteins belong to different functional classes, such as inflammatory response, immune system and metabolism. In particular, as shown by the pathway analysis, the network built with our proteins highlights the involvement of inflammatory response in CFS pathogenesis.

CONCLUSIONS

This study shows the presence of differentially expressed proteins in the saliva of the couple of monozygotic twins discordant for CFS, probably related to the disease. Consequently, we believe the proteomic approach could be useful both to define a panel of potential diagnostic biomarkers and to shed new light on the comprehension of the pathogenetic pathways of CFS.

Proteomic studies of formalin-fixed paraffin-embedded tissues

Formalin-fixed paraffin-embedded (FFPE) tissue specimens represent a valuable informational resource of histologically characterized specimens for proteomic studies. In this article, the authors review the advancement performed in the field of FFPE proteomics focusing on formaldehyde treatment and on strategies addressed to obtain the best recovery in the protein/peptide extraction. A variety of approaches have been used to characterize protein tissue extracts, and many efforts have been performed demonstrating the comparability between fresh/frozen and FFPE proteomes. Finally, the authors report and discuss the large numbers of works aimed at developing new strategies and sophisticated platforms in the analysis of FFPE samples to validate known potential biomarkers and to discover new ones.

Presence in the pre-surgical fine-needle aspiration of potential thyroid biomarkers previously identified in the post-surgical one

Fine-needle aspiration biopsy (FNA) is usually applied to distinguish benign from malignant thyroid nodules. However, cytological analysis cannot always allow a proper diagnosis. We believe that the improvement of the diagnostic capability of pre-surgical FNA could avoid unnecessary thyroidectomy. In a previous study, we performed a proteome analysis to examine FNA collected after thyroidectomy. With the present study, we examined the applicability of these results on pre-surgical FNA. We collected pre-surgical FNA from 411 consecutive patients, and to obtain a correct comparison with our previous results, we processed only benign (n = 114), papillary classical variant (cPTC) (n = 34) and papillary tall cell variant (TcPTC) (n = 14) FNA. We evaluated levels of five proteins previously found up-regulated in thyroid cancer with respect to benign nodules. ELISA and western blot (WB) analysis were used to assay levels of L-lactate dehydrogenase B chain (LDHB), Ferritin heavy chain, Ferritin light chain, Annexin A1 (ANXA1), and Moesin in FNA. ELISA assays and WB analysis confirmed the increase of LDHB, Moesin, and ANXA1 in pre-surgical FNA of thyroid papillary cancer. Sensitivity and specificity of ANXA1 were respectively 87 and 94% for cPTC, 85 and 100% for TcPTC. In conclusion, a proteomic analysis of FNA from patients with thyroid nodules may help to distinguish benign versus malignant thyroid nodules. Moreover, ANXA1 appears to be an ideal candidate given the high sensitivity and specificity obtained from ROC curve analysis.

New insight into benign tumours of major salivary glands by proteomic approach

Major salivary gland tumours are uncommon neoplasms of the head and neck. The increase of precise pre-operative diagnosis is crucial for their correct management and the identification of molecular markers would surely improve the required accuracy. In this study we performed a comparative proteomic analysis of fine needle aspiration fluids of the most frequent benign neoplasms of major salivary glands, namely pleomorphic adenoma and Warthin's tumour, in order to draw their proteomic profiles and to point out their significant features. Thirty-five patients submitted to parotidectomy were included in the study, 22 were identified to have pleomorphic adenoma and 14 Warthin's tumour. Fine needle aspiration samples were processed using a two-dimensional electrophoresis/mass spectrometry-based approach. A total of 26 differentially expressed proteins were identified. Ingenuity software was used to search the biological processes to which these proteins belong and to construct potential networks. Intriguingly, all Warthin's tumour up-regulated proteins such as Ig gamma-1 chain C region, Ig kappa chain C region and Ig alpha-1 chain C region and S100A9 were correlated to immunological and inflammatory diseases, while pleomorphic adenomas such as annexin A1, annexin A4, macrophage-capping protein, apolipoprotein E and alpha crystalline B chain were associated with cell death, apoptosis and tumorigenesis, showing different features of two benign tumours. Overall, our results shed new light on the potential usefulness of a proteomic approach to study parotid tumours and in particular up regulated proteins are able to discriminate two types of benign parotid lesions.

The mitochondrial Italian Human Proteome Project initiative (mt-HPP)

Mitochondria carry maternally inherited genetic material, called the mitochondrial genome (mtDNA), which can be defined as the 25th human chromosome. The chromosome-centric Human Proteome Project (c-HPP) has initially focused its activities addressing the characterization and quantification of the nuclear encoded proteins. Following the last International HUPO Congress in Boston (September 2012) it was clear that however small the mitochondrial chromosome is, it plays an important role in many biological and physiopathological functions. Mutations in the mtDNA have been shown to be associated with dozens of unexplained disorders and the information contained in the mtDNA should be of major relevance to the understanding of many human diseases. Within this paper we describe the Italian initiative of the Human Proteome Project dedicated to mitochondria as part of both programs: chromosome-centric (c-HPP) and Biology/Disease (B/D-HPP). The mt-HPP has finally shifted the attention of the HUPO community outside the nuclear chromosomes with the general purpose to highlight the mitochondrial processes influencing the human health. Following this vision and considering the large interest and evidence collected on the non-Mendelian heredity of Homo sapiens associated with mt-chromosome and with the microbial commensal ecosystem constituting our organism we may speculate that this program will represent an initial step toward other HPP initiatives focusing on human phenotypic heredity.

The activation of mitochondrial BK potassium channels contributes to the protective effects of naringenin against myocardial ischemia/reperfusion injury

Naringenin (NAR), flavonoid abundant in the genus Citrus, has been reported to interact with the large-conductance calcium-activated potassium channels (BK). Since activators of BK channels expressed in cardiac mitochondria trigger protective effects in several models of myocardial ischemia/reperfusion (I/R), this work aimed to evaluate the potential cardioprotective effects of NAR and the involvement of mitochondrial BK channels. In an in vivo model of acute infarct in rats, NAR (100mg/kg i.p.) significantly reduced the heart injury induced by I/R. This effect was antagonized by the selective BK-blocker paxilline (PAX). The cardioprotective dose of NAR did not cause significant effects on the blood pressure. In Largendorff-perfused rat hearts submitted to ischemia/reperfusion, NAR improved the post-ischemic functional parameters (left ventricle developed pressure and dP/dt) with lower extension of myocardial injury. On isolated rat cardiac mitochondria, NAR caused a concentration-dependent depolarization of mitochondrial membrane and caused a trans-membrane flow of thallium (potassium-mimetic cation). Both these effects were antagonized by selective blockers of BK channels. Furthermore, NAR half-reduced the calcium accumulation into the matrix of cardiac mitochondria exposed to high calcium concentrations. In conclusion, NAR exerts anti-ischemic effects through a "pharmacological preconditioning" that it is likely to be mediated, at least in part, by the activation of mitochondrial BK channels.

Serotonin receptor of type 6 (5-HT6) in human prefrontal cortex and hippocampus post-mortem: an immunohistochemical and immunofluorescence study

Given the paucity of data on the distribution of serotonin (5-HT) receptors of type 6 (5-HT(6)) in the human brain, the aim of this study was to investigate their distribution in postmortem human prefrontal cortex, striatum and hippocampus by either immunohistochemical or immunofluorescence techniques. The brain samples were obtained from 6 subjects who had died for causes not involving primarily or secondarily the CNS. The 5-HT(6) receptor distribution was explored by the [(125)I]SB-258585 binding to brain membranes followed by immunohistochemical and immunofluorescence evaluations. A specific [(125)I]SB-258585 binding was detected in all the regions under investigation, whilst the content in the hippocampus and cortex being about 10-30 times lower than in the striatum. Immunohistochemistry and double-label immunofluorescence microscopy experiments, carried out in the prefrontal cortex and hippocampus only, since data in the striatum were already published, showed the presence of 5-HT(6) receptors in both pyramidal and glial cells of prefrontal cortex, while positive cells were mainly pyramidal neurons in the hippocampus. The heterogeneous distribution of 5-HT(6) receptors provides a preliminary explanation of how they might regulate different functions in different brain areas, such as, perhaps, brain trophism in the cortex and neuronal firing in the hippocampus. This study, taking into account all the limitations due to the postmortem model used, represents the starting point to explore the 5-HT(6) receptor functionality and its sub-cellular distribution.

The trace element content of top-soil and wild edible mushroom samples collected in Tuscany, Italy

The amount of the trace elements As, Ba, Cd, Cr, Cu, Hg, Li, Mn, Ni, Pb, Rb, Se, Sr, and Zn was measured in top soils and edible mushrooms, Boletus edulis, Macrolepiota procera, collected at five distinct green microhabitats inside the Lucca province, North-Central Italy (years 2008-2009). Results showed a top soil element content within the Italian statutory limits. Concerning the amount of mushroom elements, we observed significant species-differences obtaining higher levels of Ni, Rb, and Se in B. edulis or As, Pb, Cu in M. procera. Bioaccumulation factors (BCFs: element in mushroom/element in soil) resulted species-dependent and element-selective: in particular, B. edulis preferentially accumulated Se (BCFs varying from 14 to 153), while M. procera mainly concentrated Cu (BCFs varying from 5 to 15). As well, both species displayed between-site BCF differences. By a multivariate principal component approach, cluster analysis (CA), we could resolve two main clusters of soil element composition, corresponding to the most ecologically divergent sites. Besides, CA showed no cluster relating to element contents of B. edulis at the different collection sites, while a separation in groups was found for M. procera composition with respect to harvesting locations, suggesting uptake systems, in this saprotrophic species, sensitive to microhabitat. Regarding consumer safety, Cd, Hg, Pb levels resulted sometime relevant in present samples, never reaching values from current literature on mushrooms collected in urban-polluted areas. Our findings encourage a deeper assessment of the molecular mechanisms of metal intake by edible mushrooms, encompassing genetic biochemical and geo-ecological variables, with particular awareness to element bioavailability in soils and fungi.

Role of translocator protein (18 kDa) in adult separation anxiety and attachment style in patients with depression

BACKGROUND AND OBJECTIVES

A role for the protein that mediates the rate-limiting step of steroidogenesis, the 18 kDa Translocator Protein (TSPO), has been suggested in the pathophysiology of Adult Separation Anxiety Disorder (ASAD). It has been shown that ASAD patients have 1) low TSPO expression levels and 2) a high frequency of the allele that substitutes Ala with Thr at position 147 of TSPO. The Thr147 ASAD-associated allele has been recently related with a low pregnenolone production. The aim of the present work was to evaluate the relationship between TSPO expression levels and Ala147Thr single nucleotide polymorphism (SNP), which are the two TSPO biological parameters that we have previously examined separately. A further aim was to confirm the genetic association of Ala147Thr SNP with ASAD in an extended case-control sample and to investigate whether this SNP was related to an anxious attachment style that is thought to be connected to ASAD.

METHODS

TSPO expression levels were compared among patients with ASAD (n=26), without ASAD (n=26) and control samples (n=10) stratified into the two genotype groups: those with the Ala147 genotype (named "normal pregnenolone production") and those with the Thr147 genotype (named "reduced pregnenolone production"). The case-control genetic study included patients with (n=87) or without (n=101) ASAD and 236 controls. In the patient group, the association between the Ala147Thr SNP and an anxious attachment style was analysed by stepwise logistic regression analysis.

RESULTS

The genotype with the lowest TSPO expression levels was the "normal pregnenolone production" genotype in the ASAD group. The genetic Ala147Thr SNP confirmed an excess of the Thr147 allele in ASAD patients. Stepwise logistic regression analysis did not show an association with an anxious attachment style.

CONCLUSIONS

ASAD individuals who expressed normal TSPO levels exhibited the "reduced pregnenolone production" genotype. In contrast, the ASAD individuals with the "normal pregnenolone production" genotype expressed low TSPO levels. It is possible that low TSPO expression levels could compromise normal pregnenolone production. Such evidence may have therapeutic implications because it has been documented that drugs targeting TSPO increased pregnenolone production and have anxiolytic effects.

RP-LC of phenylthiocarbamyl amino acid adducts in plasma acetonitrile extracts: use of multiple internal standards and variable wavelength UV detection

The measurement of physiological amino acids in body fluids and circulating cells can be relevant in the search for biological correlates of neuropsychiatric, neurological, body weight, and pain diseases. Several techniques are available for the quantitative analysis of free amino acids, including UV detection after precolumn derivatization. These systems have low specificity due to possible interferences at the analytical wavelength. Another problem linked to these methods is variations potentially occurring during extraction, derivatization, and chromatography of amino acids in biological matrices. We present here a modified reversed-phase LC of phenylthiocarbamyl amino acids in plasma deproteinated by the organic solvent acetonitrile. Specificity was monitored by UV-photodiode array detection and accuracy was controlled by a plasma spiking procedure with three internal standards. A dual-wavelength spectrophotometry (254, 283 nm) was used to quantify coeluting ornithine and tryptophan adducts. The method is simple and economical and enables the measure of most plasma amino acids for clinical research, also during therapeutic drug monitoring. Dual UV-fluorimetric detection solutions can improve its sensitivity.

Proteomic analysis of saliva: a unique tool to distinguish primary Sjögren's syndrome from secondary Sjögren's syndrome and other sicca syndromes

Introduction

A growing interest has arisen in salivary proteomics as a tool for the identification of biomarkers for primary Sjögren's syndrome (pSS). Nonetheless, only a limited number of preclinical validation studies have been performed, limiting the possibility of translating proteomic results into clinical practice. The primary aim of this study was to refine the diagnostic power of a panel of candidate salivary biomarkers described in pSS with respect to both healthy volunteers and pathological controls. We also explored the pathogenetic function of the detected putative biomarkers both in the local exocrinopathy and in the systemic inflammatory processes of SS.

Methods

One hundred and eighty patients were included in the study overall. In the first "exploratory phase", we enrolled 40 females with pSS, 40 sex- and age-matched healthy volunteers, 10 patients with sicca non-SS and 15 secondary SS (sSS) patients. The testing cohort of the second "challenge phase" of the study was represented by 75 unselected, consecutive subjects: 19 pSS, 21 healthy volunteers, 10 sicca non-SS and 25 sSS patients. Salivary proteomic analysis was performed combining two-dimensional electrophoresis (2DE) and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS). Western blot (WB) analysis and enzyme-linked immunosorbent assay (ELISA) were employed to validate 2DE results. Ingenuity Pathway Analysis (IPA) Knowledge base was adopted to associate candidate biomarkers in a signalling pathogenetic network.

Results

A total of 28, 6, 7 and 12 protein spots were found to be significantly different in pSS samples with respect to healthy volunteers, non-SS sicca syndrome, SSc-sSS and rheumatoid arthritis-sSS, leading to the identification of 15 differently expressed proteins. Among them, α-amylases precursor, carbonic anhydrase VI, β-2 microglobulin, glyceraldehydes-3-phosphate dehydrogenase (G3PDH), epidermal fatty acid binding protein (E-FABP) and immunoglobulin k light chain (IGK-light chain) apparently showed the most significant differences in pSS when compared to healthy volunteers and non-SS pathological controls. On the other hand, as expected, pSS and sSS salivary profiles shared a great number of similarities.

Conclusions

This study demonstrated that salivary fluid might represent a novel ideal milieu for the detection of a diagnostic panel of candidate biomarkers for pSS, and to gain an insight into the pathogenetic processes underlying glandular and systemic autoimmune disorders.

[MALDI-TOF and SELDI-TOF analysis: "tandem" techniques to identify potential biomarker in fibromyalgia]

OBJECTIVE

Fibromyalgia (FM) is characterized by the presence of chronic widespread pain throughout the musculoskeletal system and diffuse tenderness. Unfortunately, no laboratory tests have been appropriately validated for FM and correlated with the subsets and activity. The aim of this study was to apply a proteomic technique in saliva of FM patients: the Surface Enhance Laser Desorption/Ionization Time-of-Flight (SELDI-TOF).

METHODS

For this study, 57 FM patients and 35 HC patients were enrolled. The proteomic analysis of saliva was carried out using SELDI-TOF. The analysis was performed using different chip arrays with different characteristics of binding. The statistical analysis was performed using cluster analysis and the difference between two groups was underlined using Student’s t-test.

RESULTS

Spectra analysis highlighted the presence of several peaks differently expressed in FM patients compared with controls. The preliminary results obtained by SELDI-TOF analysis were compared with those obtained in our previous study performed on whole saliva of FM patients by using electrophoresis. The m/z of two peaks, increased in FM patients, seem to overlap well with the molecular weight of calgranulin A and C and Rho GDP-dissociation inhibitor 2, which we had found up-regulated in our previous study.

CONCLUSION

These preliminary results showed the possibility of identifying potential salivary biomarker through salivary proteomic analysis with MALDI-TOF and SELDI-TOF in FM patients. The peaks observed allow us to focus on some of the particular pathogenic aspects of FM, the oxidative stress which contradistinguishes this condition, the involvement of proteins related to the cytoskeletal arrangements, and central sensibilization.

Correspondence between salivary proteomic pattern and clinical course in primary Sjögren syndrome and non-Hodgkin's lymphoma: a case report

Background

In the last years human proteomic has represented a promising tool to promote the communication between basic and clinical science.

Methods

To explore the correspondence between salivary proteomic profile and clinical response, herein, we used a proteomic approach to analyse the whole saliva of a patient with primary Sjögren's Syndrome (pSS) and non-Hodgkin's-MALT type parotid lymphoma before, during and after a standard treatment with cyclophosphamide (CTX) and rituximab (RTX). To identify any discriminatory therapeutic salivary biomarker patient's whole saliva was collected at the baseline, after the fourth infusion of rituximab, and on remission and analysed combining two-dimensional electrophoresis (2DE) and MALDI-TOF/TOF mass spectrometry.

Results

Proteomic results obtained from the comparison of salivary samples indicated several qualitative and quantitative modifications in the salivary expression of putative albumin, immunoglobulin J chain, Ig kappa chain C region, alpha-1-antitrypsin, haptoglobin and Ig alpha-1 chain C region.

Conclusion

This study suggests that clinical and functional changes of the salivary glands driven by autoimmune and lymphoproliferative processes might be reflected in patients' whole saliva proteins, shedding new light on the potential usefulness of salivary proteomic analysis in the identification of prognostic and therapeutic biomarkers for patients with pSS and non Hodgkin's lymphomas.

Synthesis of sulfonamide-containing N-hydroxyindole-2-carboxylates as inhibitors of human lactate dehydrogenase-isoform 5

N-Hydroxyindole-2-carboxylates possessing sulfonamide-substituents at either position 5 or 6 were designed and synthesized. The inhibitory activities of these compounds against isoforms 1 and 5 of human lactate dehydrogenase were analysed, and K(i) values of the most efficient inhibitors were determined by standard enzyme kinetic studies. Some of these compounds displayed state-of-the-art inhibitory potencies against isoform 5 (K(i) values as low as 5.6 μM) and behaved as competitive inhibitors versus both the substrate and the cofactor.

N-Hydroxyindole-based inhibitors of lactate dehydrogenase against cancer cell proliferation

Current cancer research is being increasingly focused on the study of distinctive characters of tumour metabolism, resulting in a switch from oxidative phosphorylation to glycolysis (Warburg effect). Isoform 5 of human lactate dehydrogenase (hLDH5), which catalyzes the final step in the glycolytic cascade (pyruvate to lactate), constitutes a relatively new and untapped anti-cancer target. In this study, careful design and synthesis of a selected series of aryl-substituted N-hydroxyindole-2-carboxylates (NHIs) has led to several hLDH5-inhibitors, showing "first-in-class" potency and isoform selectivity. Enzyme kinetics studies indicated that these inhibitors exhibit a competitive mode of inhibition. Some representative examples were tested against two human pancreatic carcinoma cell lines, and displayed a good anti-proliferative activity, which was even more evident under hypoxic conditions.

New insight into the central benzodiazepine receptor-ligand interactions: design, synthesis, biological evaluation, and molecular modeling of 3-substituted 6-phenyl-4H-imidazo[1,5-a][1,4]benzodiazepines and related compounds

3-Substituted 6-phenyl-4H-imidazo[1,5-a][1,4]benzodiazepines and related compounds were synthesized as central benzodiazepine receptor (CBR) ligands. Most of the compounds showed high affinity for bovine and human CBR, their K(i) values spanning from the low nanomolar to the submicromolar range. In particular, imidazoester 5f was able to promote a massive flow of (36)Cl(-) in rat cerebrocortical synaptoneurosomes overlapping its efficacy profile with that of a typical full agonist. Compound 5f was then examined in mice for its pharmacological effects where it proved to be a safe anxiolytic agent devoid of the unpleasant myorelaxant and amnesic effects of the classical 1,4-benzodiazepines. Moreover, the selectivity of some selected compounds has been assessed in recombinant α(1)β(2)γ(2)L, α(2)β(1)γ(2)L, and α(5)β(2)γ(2)L human GABA(A) receptors. Finally, some compounds were submitted to molecular docking calculations along with molecular dynamics simulations in the Cromer's GABA(A) homology model.

Rosiglitazone reverses salbutamol-induced β(2) -adrenoceptor tolerance in airway smooth muscle

BACKGROUND AND PURPOSE

β₂-Adrenoceptor agonists are important therapeutic agents in the treatment of asthma and chronic obstructive pulmonary disease. The regular use of these drugs has been associated with proasthmatic-like changes that limit their efficacy and increase the risk of severe adverse reactions. We investigated whether the peroxisome-proliferator-activated receptor (PPAR)γ agonist rosiglitazone modulated salbutamol-induced β₂-adrenoceptor desensitization in vivo and in vitro.

EXPERIMENTAL APPROACH

An in vivo model of homologous β₂-adrenoceptor desensitization, established in guinea-pigs by administering salbutamol continuously, was used to study the ability of rosiglitazone to prevent β₂-adrenoceptor tolerance. In vitro experiments on human bronchial smooth muscle cells were performed to increase the clinical relevance of the study.

KEY RESULTS

In tracheal smooth muscle tissues from desensitized animals, we observed a decrease in the protective effect of salbutamol on carbachol-induced contraction, a hyperresponsiveness to cholinergic stimuli, a modest underexpression of β₂-adrenoceptor gene and a marked decrease in β-adrenoceptor number, relative to control values. Treatment with rosiglitazone preserved salbutamol relaxant activity, mitigated carbachol hyperresponsiveness and partially restored β₂-adrenoceptor binding sites in tracheal tissues from homologously desensitized animals. The highly selective PPARγ agonist, GW1929, reproduced the effect of rosiglitazone, in vivo. In vitro β₂-adrenoceptor desensitization decreased salbutamol-mediated cAMP production, without affecting forskolin responses and β₂-adrenoceptor expression. Rosiglitazone and 15-deoxy-Δ¹²(,)¹⁴-prostaglandin J₂ restored salbutamol sensitivity in homologously desensitized cells.

CONCLUSIONS AND IMPLICATIONS

These data suggest a potential pharmacodynamic interaction between PPARγ agonists and salbutamol on airway smooth muscle responsiveness, supporting the therapeutic potential of this combination in chronic airway disease.