Regulatory sites of CaM-sensitive adenylyl cyclase AC8 revealed by cryo-EM and structural proteomics.

Membrane adenylyl cyclase AC8 is regulated by G proteins and calmodulin (CaM), mediating the crosstalk between the cAMP pathway and Ca2+ signalling. Despite the importance of AC8 in physiology, the structural basis of its regulation by G proteins and CaM is not well defined. Here, we report the 3.5 Å resolution cryo-EM structure of the bovine AC8 bound to the stimulatory Gαs protein in the presence of Ca2+/CaM. The structure reveals the architecture of the ordered AC8 domains bound to Gαs and the small molecule activator forskolin. The extracellular surface of AC8 features a negatively charged pocket, a potential site for unknown interactors. Despite the well-resolved forskolin density, the captured state of AC8 does not favour tight nucleotide binding. The structural proteomics approaches, limited proteolysis and crosslinking mass spectrometry (LiP-MS and XL-MS), allowed us to identify the contact sites between AC8 and its regulators, CaM, Gαs, and Gßγ, as well as to infer the conformational changes induced by these interactions. Our results provide a framework for understanding the role of flexible regions in the mechanism of AC regulation.

Gastric ultrasound, citrulline, and intestinal fatty acid-binding protein as markers of gastrointestinal dysfunction in critically ill patients: A pilot prospective cohort study.

BACKGROUND: Gastrointestinal (GI) dysfunction is common in the intensive care unit (ICU), although there is no consensus on biomarkers of GI dysfunction. We aimed to evaluate ultrasound-based gastric antrum measurements and serum intestinal fatty acid-binding protein (IFABP) and citrulline levels in relation to GI dysfunction in critically ill patients. METHODS: Adult critically ill patients receiving enteral nutrition and stayed for in the ICU for ≥48 h was included. GI dysfunction was described using Gastrointestinal Dysfunction Score (GIDS). Gastric antrum measurements, including craniocaudal (CC) diameter, anteroposterior diameter, and antral-cross sectional area (CSA), as well as serum levels for IFABP and citrulline, were prospectively recorded at baseline and on day 3 and day 5 of enteral nutrition. The receiver operating characteristic (ROC) analysis was performed to evaluate gastric ultrasound parameters, serum IFABP, and citrulline concentrations in predicting GI dysfunction. RESULTS: Thirty-nine participants with a median age of 60 years were recruited and 46.2% of participants had GI dysfunction. ROC analysis revealed that the cutoff value of CSA score to predict GI dysfunction was 4.48 cm2 , which provided 72.7% sensitivity and 77.2% specificity (area under the curve = 0.768, 95% CI: 0.555-0.980). At baseline, gastric residual volume was highly correlated with CC diameter and CSA (r = 0.764, P < 0.001 and r = 0.675, P < 0.001, respectively). Serum IFABP and citrulline levels had no correlation with GI dysfunction or gastric ultrasound parameters (P > 0.05). CONCLUSION: CSA was associated with GI dysfunction in critically ill patients. Serum IFABP and citrulline concentrations were poor in predicting GI dysfunction.

New Avenues to Explore in SARS-CoV-2 Infection: Both TRIM25 and TRIM56 Positively Correlate with VEGF, GAS6, and sAXL in COVID-19 Patients.

The ongoing COVID-19 pandemic poses a significant threat to human health. Many hypotheses regarding pathogenesis have been proposed and are being tried to be clarified by experimental and clinical studies. This study aimed to reveal the roles of the innate immune system modulator GAS6/sAXL pathway, endothelial dysfunction markers vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF)-1α, and antiviral effective TRIM25 and TRIM56 proteins in pathogenesis of COVID-19. The study included 55 patients with COVID-19 and 25 healthy individuals. The serum levels of GAS6, sAXL, VEGF, HIF-1α, TRIM25, and TRIM56 were measured using commercial ELISA kits and differences between COVID-19 patients and healthy controls, and the relationship to severity and prognosis were evaluated. GAS6, sAXL, TRIM56, and VEGF were found to be higher, while TRIM25 was lower in patients. There were strong positive correlations between GAS6, sAXL, TRIM25, TRIM56, and VEGF. None of the research parameters other than HIF-1α was associated with severity or prognosis. However, HIF-1α was positively correlated with APACHE II. We speculate that the antiviral effective TRIM25 and TRIM56 proteins, as well as the GAS6/sAXL pathway, act together as a defense mechanism in COVID-19. We hope that our study will contribute to further studies to elucidate the molecular mechanism associated with TRIM56, TRIM25, GAS6, sAXL, and VEGF in COVID-19 patients.

The effectiveness of telerehabilitation-based structured exercise therapy for chronic nonspecific neck pain: A randomized controlled trial.

INTRODUCTION: The aim of this research was to investigate the effects of telerehabilitation-based remote supervised or unsupervised structured exercise therapy on pain, disability, and quality of life related to chronic nonspecific neck pain. METHOD: The study was designed as a single-blinded randomized controlled trial. Sixty-six eligible chronic nonspecific neck pain patients were randomized across three groups: remote supervised group (RSG, n = 22), unsupervised group (UG, n = 22), and waitlist control group (CG, n = 22). Progressive structured exercise therapy program was delivered weekly to patients in remote supervised group and unsupervised group to perform four days a week for four weeks. Remote supervised group was supervised by videoconference and text message. Pain, disability, and quality of life of participants were assessed at baseline, week 2, and post-therapy. RESULTS: Post-therapy pain and disability total change scores were -3.64 (95% CI -4.85 to -2.42) and -7.27 (95% CI -11.05 to -3.50) for remote supervised group compared with a change of -2.44 (95% CI -3.46 to -1.43) and -5.77 (95% CI -8.54 to -3.01) for unsupervised group, respectively. Post-therapy, quality of life improvements were greater for remote supervised group than unsupervised group overall (general health; remote supervised group: 19.01 (95% CI 6.86 to 31.16), unsupervised group: 12.50 (95% CI 4.79 to 20.21), and physical health; remote supervised group: 18.35 (95% CI 10.35 to 26.35), unsupervised group: 7.31 (95% CI 0.01 to 14.60)). Significant improvements in psychological health and environment-telerehabilitation for remote supervised group were not seen for unsupervised group and outcomes differences did not reach significance for control group (p > 0.05) post-therapy, except environment-telerehabilitation. DISCUSSION: Structured exercise therapy can improve chronic nonspecific neck pain outcomes when remotely supervised or unsupervised. Structured exercise therapy content and frequent communication are important for remote chronic nonspecific neck pain management.

SAHA induce hippo pathway in CCA cells without increasing cell proliferation.

BACKGROUND: Cholangiocarcinoma is a malignant tumor originating from bile duct epithelial cells. Since tumor metastasis is associated with poor prognosis and short-term survival of patients, there is an urgent need for alternative therapeutic approaches for CCA. Because of that reason, we aimed to investigate effect of SAHA which is known as HDAC inhibitor on extrahepatic cholangiocarcinoma cell line (TFK-1). METHODS: Cell cycle was measured by Muse Cell Analyzer. YAP, TAZ, TGF-ß protein levels were determined by western-blotting method. TEAD (1-3), TIMP2 and TIMP3 genes level were determined by real-time PCR analysis. RESULTS: We have seen the positive effects of SAHA on the TFK-1 cell line as it reduces cell viability and arresting cells in the G0/G1 phase. We also observed the negative effects of SAHA, as it increases the expression levels of YAP, TAZ, TGF-ß protein and TEAD (1-3) gene. We also found that SAHA reduced the expression levels of TIMP2 and TIMP3 in TFK-1 cells, but was not statistically significant. CONCLUSIONS: Although observing its antiproliferative effects, these negative effects may be related to the cells being resistant to the drug or the remaining cells having a more aggressive phenotype. Therefore, we think that caution should be exercised in the use of this drug for CCA treatment.

The Effect of EZH2 Inhibition through DZNep on Epithelial-Mesenchymal Transition Mechanism.

Although the molecular pathogenesis of hepatocellular carcinoma (HCC) is uncertain, it is known that the epithelial-mesenchymal transition (EMT) mechanism and epigenetic changes have an important role. This study was focused on evaluating the relationship of 3-Deazaneplanocin A (DZNep) with the EMT mechanism, which is a histone methyltransferase inhibitor on HCC and is also known as an enhancer of zeste homolog 2 (EZH2) inhibitor. Cell viability of HepG2 cells (HCC cell line) assessed for DZNep over 72 hours with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Additionally, colony-forming assay, apoptosis assay, RNA isolation, cDNA synthesis, and real-time PCR (RT-PCR) were performed to see the effect of DZNep on HepG2 cells. DZNep reduced cell proliferation for 72 hours, also significantly reduced colony formation in addition it increased the total apoptosis. DZNep on EZH2, E-cadherin, N-cadherin, and Vimentin (Vim) gene expressions was given different results by either decreasing or increasing the expressions. In this study, we observed a positive effect of DZNep on apoptosis and TIMP3 expression level and decreased colony formation. However, it gave complicated results with the level of gene expression E-cadherin and TIMP2, increase the level of Vim and MMP2 expression. Therefore, we think that further studies are necessary to clarify the role of DZNep.

Suberoylanilide Hydroxamic Acid (SAHA) Reduces Fibrosis Markers and Deactivates Human Stellate Cells via the Epithelial-Mesenchymal Transition (EMT).

Hepatic fibrosis is known as the accumulation of connective tissue secondary to chronic damage to the liver. Epithelial-mesenchymal transition (EMT) corresponding increase in liver fibrogenesis was shown with immunohistochemistry and PCR-based studies. Suberoylanilide hydroxamic acid (SAHA), a synthetic compound approved as a histone deacetylase inhibitor (HDAC) by the FDA to treat cutaneous T-cell lymphoma is under investigation for the treatment of lung and renal fibrosis. Experimental modeling for hepatic fibrosis can be constructed with an LX2 cell line isolated from human hepatic stellate cells (HSCs). In this study, we aimed to investigate the modulation of SAHA in the pathogenesis of liver fibrosis by detecting the levels of proteins; (E-cadherin (E-cad), N-cadherin (N-cad), Vimentin (Vim), and genes; E-cad, N-cad, Vim, transforming growth factor-beta (TGF-ß), alpha-smooth muscle actin (α-SMA), type 1 collagen (COL1A1), type 3 collagen (COL3A1)) that play a significant role in EMT with the LX2 cell line. We also evaluated the action of SAHA with cell proliferation, clonogenic, and migration assay. Cell proliferation was performed by flow cytometry. All the protein levels were determined by Western blot analysis, and gene expression levels were measured by Real-Time PCR. Our study observed that SAHA treatment decreased cell viability, colony formation and migration in LX2 cells. We found that SAHA increased E-cad expression level, while it decreased N-cad, Vim, COL1A1, COL3A1, α-SMA TGF-ß genes expression levels. SAHA decreased the level of E-cad, N-cad, and Vim protein levels. We thought that SAHA possesses potent antifibrotic and anti-EMT properties in LX2.

Quercetin adsorption with imprinted polymeric materials.

In this study, molecularly imprinted polymer membranes were synthesized for the recognition and adsorption of quercetin. For this, quercetin imprinted polymeric membranes [p(HEMA-MAH)] (Poly(2-hydroxyethyl methacrylate-co-N-methacryloly-l-histidinemethylester) were synthesized by UV polymerization technique using HEMA and MAH as monomers. Synthesized polymeric membranes were characterized with SEM, FTIR and swelling test. Characterized membranes were used for the direct adsorption of quercetin in a batch system. Quercetin adsorption conditions were optimized by using the quercetin imprinted polymeric membrane by altering the pH, temperature and initial quercetin concentration of the adsorption medium. Effect of adsorption time was also studied for up to 180 min. The optimum pH and temperature was determined between 4.0 and 45 °C. Maximum adsorbed amount of quercetin onto quercetin imprinted poly(HEMA-MAH) membrane was found to be as 299.6 mg/g membrane using the initial quercetin concentration of 2.0 mg/ml. Adsorbed quercetin was desorbed from the polymeric membranes with isopropyl alcohol with desorption yield of 98.3%. and repeated usability of the quercetin imprinted polymeric membranes was fallowed for 7 adsorption/desorption cycles. At the end of the 7th reuse, quercetin adsorption capacity of the quercetin imprinted poly(HEMA-MAH) membranes decreased only about 10%.