Mouse Stbd1 is N-myristoylated and affects ER–mitochondria association and mitochondrial morphology

Starch binding domain-containing protein 1 (Stbd1) is a carbohydrate-binding protein that has been proposed to be a selective autophagy receptor for glycogen. Here, we show that mouse Stbd1 is a transmembrane endoplasmic reticulum (ER)-resident protein with the capacity to induce the formation of organized ER structures in HeLa cells. In addition to bulk ER, Stbd1 was found to localize to mitochondria-associated membranes (MAMs), which represent regions of close apposition between the ER and mitochondria. We demonstrate that N-myristoylation and binding of Stbd1 to glycogen act as major determinants of its subcellular targeting. Moreover, overexpression of non-myristoylated Stbd1 enhanced the association between ER and mitochondria, and further induced prominent mitochondrial fragmentation and clustering. Conversely, shRNA-mediated Stbd1 silencing resulted in an increase in the spacing between ER and mitochondria, and an altered morphology of the mitochondrial network, suggesting elevated fusion and interconnectivity of mitochondria. Our data unravel the molecular mechanism underlying Stbd1 subcellular targeting, support and expand its proposed function as a selective autophagy receptor for glycogen and uncover a new role for the protein in the physical association between ER and mitochondria

5-(1H-Indol-3-ylmethylene)-4-oxo-2-thioxothiazolidin-3-yl)alkancarboxylic Acids as Antimicrobial Agents: Synthesis, Biological Evaluation, and Molecular Docking Studies

Background: Infectious diseases symbolize a global consequential strain on public health security and impact on the socio-economic stability all over the world. The increasing resistance to the current antimicrobial treatment has resulted in crucial need for the discovery and development of novel entity for the infectious treatment with different modes of action that could target both sensitive and resistant strains. Methods: Compounds were synthesized using classical methods of organic synthesis. Results: All 20 synthesized compounds showed antibacterial activity against eight Gram-positive and Gram-negative bacterial species. It should be mentioned that all compounds exhibited better antibacterial potency than ampicillin against all bacteria tested. Furthermore, 18 compounds appeared to be more potent than streptomycin against Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa, Listeria monocytogenes, and Escherichia coli. Three the most active compounds 4h, 5b, and 5g appeared to be more potent against MRSA than ampicillin, while streptomycin did not show any bactericidal activity. All three compounds displayed better activity also against resistant strains P. aeruginosa and E. coli than ampicillin. Furthermore, all compounds were able to inhibit biofilm formation 2- to 4-times more than both reference drugs. Compounds were evaluated also for their antifungal activity against eight species. The evaluation revealed that all compounds exhibited antifungal activity better than the reference drugs bifonazole and ketoconazole. Molecular docking studies on antibacterial and antifungal targets were performed in order to elucidate the mechanism of antibacterial activity of synthesized compounds. Conclusion: All tested compounds showed good antibacterial and antifungal activity better than that of reference drugs and three the most active compounds could consider as lead compounds for the development of new more potent agents

Stbd1-deficient mice display insulin resistance associated with enhanced hepatic ER-mitochondria contact

Starch binding domain-containing protein 1 (STBD1) is an endoplasmic reticulum (ER)-resident, glycogen-binding protein. In addition to glycogen, STBD1 has been shown to interact with several proteins implicated in glycogen synthesis and degradation, yet its function in glycogen metabolism remains largely unknown. In addition to the bulk of the ER, STBD1 has been reported to localize at regions of physical contact between mitochondria and the ER, known as Mitochondria-ER Contact sites (MERCs). Given the emerging correlation between distortions in the integrity of hepatic MERCs and insulin resistance, our study aimed to delineate the role of STBD1 in vivo by addressing potential abnormalities in glucose metabolism and ER-mitochondria communication associated with insulin resistance in mice with targeted inactivation of Stbd1 (Stbd1KO). We show that Stbd1KO mice at the age of 24 weeks displayed reduced hepatic glycogen content and aberrant control of glucose homeostasis, compatible with insulin resistance. In line with the above, Stbd1-deficient mice presented with increased fasting blood glucose and insulin levels, attenuated activation of insulin signaling in the liver and skeletal muscle and elevated liver sphingomyelin content, in the absence of hepatic steatosis. Furthermore, Stbd1KO mice were found to exhibit enhanced ER-mitochondria association and increased mitochondrial fragmentation in the liver. Nevertheless, the enzymatic activity of hepatic respiratory chain complexes and ER stress levels in the liver were not altered. Our findings identify a novel important role for STBD1 in the control of glucose metabolism, associated with the integrity of hepatic MERCs

5,8-Dimethyl-9H-carbazole Derivatives Blocking hTopo I Activity and Actin Dynamics

Over the years, carbazoles have been largely studied for their numerous biological properties, including antibacterial, antimalarial, antioxidant, antidiabetic, neuroprotective, anticancer, and many more. Some of them have gained great interest for their anticancer activity in breast cancer due to their capability in inhibiting essential DNA-dependent enzymes, namely topoisomerases I and II. With this in mind, we studied the anticancer activity of a series of carbazole derivatives against two breast cancer cell lines, namely the triple negative MDA-MB-231 and MCF-7 cells. Compounds 3 and 4 were found to be the most active towards the MDA-MB-231 cell line without interfering with the normal counterpart. Using docking simulations, we assessed the ability of these carbazole derivatives to bind human topoisomerases I and II and actin. In vitro specific assays confirmed that the lead compounds selectively inhibited the human topoisomerase I and interfered with the normal organization of the actin system, triggering apoptosis as a final effect. Thus, compounds 3 and 4 are strong candidates for further drug development in multi-targeted therapy for the treatment of triple negative breast cancer, for which safe therapeutic regimens are not yet available

Federica Giuzio*, Maria Grazia Bonomo, Alessia Catalano*, Vittoria Infantino, Giovanni Salzano, Magnus Monné, Athina Geronikaki, Anthi Petrou, Stefano Aquaro, Maria Stefania Sinicropi#, Carmela Saturnino#

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an RNA virus belonging to the coronavirus family responsible for coronavirus disease 2019 (COVID-19). It primarily affects the pulmonary system, which is the target of chronic obstructive pulmonary disease (COPD), for which many new compounds have been developed. In this study, phosphodiesterase 4 (PDE4) inhibitors are being investigated. The inhibition of PDE4 enzyme produces antiinflammatory and bronchodilator effects in the lung by inducing an increase in cAMP concentrations. Piclamilast and rolipram are known selective inhibitors of PDE4, which are unfortunately endowed with common side effects, such as nausea and emesis. The selective inhibition of the phosphodiesterase 4B (PDE4B) subtype may represent an intriguing technique for combating this highly contagious disease with fewer side effects. In this article, molecular docking studies for the selective inhibition of the PDE4B enzyme have been carried out on 21 in-house compounds. The compounds were docked into the pocket of the PDE4B catalytic site, and in most cases, they were almost completely superimposed onto piclamilast. Then, in order to enlarge our study, drug-likeness prediction studies were performed on the compounds under study

Novel Thiazolidin-4-ones as Potential Non-Nucleoside Inhibitors of HIV-1 Reverse Transcriptase

Background: HIV is the causative agent of Acquired Immunodeficiency Syndrome (AIDS), an infectious disease with increasing incidence worldwide. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) play an important role in the treatment of AIDS. Although, many compounds are already being used as anti-HIV drugs, research for the development of new inhibitors continues as the virus develops resistant strains. Methods: The best features of available NNRTIs were taken into account for the design of novel inhibitors. PASS (Prediction of activity spectra for substances) prediction program and molecular docking studies for the selection of designed compounds were used for the synthesis. Compounds were synthesized using conventional and microwave irradiation methods and HIV RT inhibitory action was evaluated by colorimetric photometric immunoassay. Results: The evaluation of HIV-1 RT inhibitory activity revealed that seven compounds have significantly lower ΙC50 values than nevirapine (0.3 μΜ). It was observed that the activity of compounds depends not only on the nature of substituent and it position in benzothiazole ring but also on the nature and position of substituents in benzene ring. Conclusion: Twenty four of the tested compounds exhibited inhibitory action lower than 4 μΜ. Seven of them showed better activity than nevirapine, while three of the compounds exhibited IC50 values lower than 5 nM. Two compounds 9 and 10 exhibited very good inhibitory activity with IC50 1 nM

N-Derivatives of (Z)-Methyl 3-(4-Oxo-2-thioxothiazolidin-5-ylidene)methyl)-1H-indole-2-carboxylates as Antimicrobial Agents—In Silico and In Vitro Evaluation

Herein, we report the experimental evaluation of the antimicrobial activity of seventeen new (Z)-methyl 3-(4-oxo-2-thioxothiazolidin-5-ylidene)methyl)-1H-indole-2-carboxylate derivatives. All tested compounds exhibited antibacterial activity against eight Gram-positive and Gram-negative bacteria. Their activity exceeded those of ampicillin as well as streptomycin by 10–50 fold. The most sensitive bacterium was En. Cloacae, while E. coli was the most resistant one, followed by M. flavus. The most active compound appeared to be compound 8 with MIC at 0.004–0.03 mg/mL and MBC at 0.008–0.06 mg/mL. The antifungal activity of tested compounds was good to excellent with MIC in the range of 0.004–0.06 mg/mL, with compound 15 being the most potent. T. viride was the most sensitive fungal, while A. fumigatus was the most resistant one. Docking studies revealed that the inhibition of E. coli MurB is probably responsible for their antibacterial activity, while 14a–lanosterol demethylase of CYP51Ca is involved in the mechanism of antifungal activity. Furthermore, drug-likeness and ADMET profile prediction were performed. Finally, the cytotoxicity studies were performed for the most active compounds using MTT assay against normal MRC5 cells

The “sweet” side of ER-mitochondria contact sites

The regions at which the ER and mitochondria come into close proximity, known as ER-mitochondria contact sites provide essential platforms for the exchange of molecules between the two organelles and the coordination of various fundamental cellular processes. In addition to the well-established role of ER-mitochondria interfaces in calcium and lipid crosstalk, emerging evidence supports that a proper communication between ER and mitochondria is critical for the regulation of mitochondrial morphology and the initiation of autophagy. Within this context, our recent data indicate that glycogen is targeted to ER-mitochondria contacts through the Stbd1 protein, a proposed autophagy receptor for glycogen. Glycogen-bound Stbd1 influences ER-mitochondria tethering and the morphology of the mitochondrial network. We here suggest possible roles of glycogen recruitment to ER-mitochondria contact sites. Stbd1-mediated targeting of glycogen to ER-mitochondria junctions could represent a mechanism through which glycogen is sequestered into autophagosomes for lysosomal degradation, a process described as glycogen autophagy or glycophagy. Additionally, we discuss a possible mechanism which links the observed effects of Stbd1 on mitochondrial morphology with the previously reported impact of nutrient availability on mitochondrial dynamics. In this model we propose that glycogen-bound Stbd1 signals nutrient status to ER-mitochondria junctions resulting in adaptations in the morphology of the mitochondrial network

Design, synthesis and evaluation of biological activity of novel thiazole derivatives

This work presents and discusses the design and synthesis of 54 novel 2, 3-aryl-thiazolidin-4-ones, with increased activity against human immunodeficiency virus (HIV). HIV is the causative agent of the Acquired Immunodeficiency Syndrome (AIDS), an infectious disease with increasing incidence worldwide. Non-nucleoside reverse transcriptase inhibitors or NNRTIs play an important role in the treatment of AIDS. However, despite the fact that many compounds are already used as anti-HIV drugs, research into the development of new inhibitors continues as the virus develops resistant strains, limiting their use. Taking into account the best features of available NNRTIs and with the aid of Molecular docking studies, it is attempted to synthesize new compounds that will not be blocked by small mutations in the reserve transcriptase (RT) binding domain, but they will exhibit a large number of interactions with RT by enhancing their anti-HIV-activity. The synthesis of the selected compounds was carried out by one-pot reaction of the appropriate heteroaromatic amine with a substituted benzaldehyde and thioglycolic acid. Identification of the products was performed using spectroscopic methods (IR, 1H-NMR, 13C-NMR and MS).Finally, an in vitro study of the inhibitory activity of the new compounds on HIV-1 RT was performed using both the immunoenzymatic colorimetric and the radioisotope methods.Molecular docking studies were carried out to enable the design of new HIV-1 RT inhibitors. The binding free energies of compounds to HIV-1 RT were found to have a good correlation with the experimental inhibitory activities. The most favorable binding mode of top-ranking compounds will be useful in designing new NNRTIs.Finally, due to the importance of antimicrobial drugs for the treatment of many microbial infections in immunocompromised patients, such as those with AIDS, in vitro studies were performed to test the antimicrobial activity of the compounds, followed by docking studies for the prediction of the most potent mechanism of antimicrobial action.Στην παρούσα διδακτορική διατριβή επιχειρείται ο σχεδιασμός και η σύνθεση νέων ενώσεων, με αυξημένη δράση κατά του ιού της ανθρώπινης ανοσοανεπάρκειας (HIV). Ο ιός HIV είναι ο αιτιολογικός παράγων του Συνδρόμου Επίκτητης Ανοσολογικής Ανεπάρκειας (AIDS), μιας λοιμώδης νόσου με αυξανόμενη επίπτωση παγκοσμίως. Οι μη νουκλεοσιδικοί αναστολείς της αντίστροφης μεταγραφάσης (RT) ή NNRTIs διαδραματίζουν σημαντικό ρόλο στην θεραπεία του AIDS. Ωστόσο, παρά το γεγονός ότι πολλές ενώσεις χρησιμοποιούνται ήδη ως φάρμακα κατά του HIV, η έρευνα για την ανάπτυξη νέων αναστολέων συνεχίζεται, καθώς ο ιός αναπτύσσει ανθεκτικά στελέχη, περιορίζοντας την χρησιμοποίησή τους. Λαμβάνοντας υπόψη τα καλύτερα χαρακτηριστικά των διαθέσιμων NNRTIs από την βιβλιογραφία και με τη βοήθεια in silico μελετών πρόσδεσης (Docking) καθώς και του υπολογιστικού προγράμματος πρόβλεψης της βιολογικής δράσης PASS, επιχειρείται ο σχεδιασμός και η σύνθεση νέων ενώσεων που δεν θα εμποδίζονται από μικρές μεταλλάξεις στην περιοχή σύνδεσης με την RT, αλλά θα εμφανίζουν περισσότερες αλληλεπιδράσεις με αυτήν, ενισχύοντας την αντι-HIV-δράση τους. Στην παρούσα διατριβή σχεδιάστηκαν και συντέθηκαν 54 νέες 2-αρυλο-3-ενζο[d]θειαζολ-θειαζολιδιν-4-όνες. Η σύνθεση των ενώσεων έγινε σύμφωνα με αντίδραση ενός βήματος («one pot») μεταξύ μιας ετεροαρωματικής αμίνης, μιας υποκατεστημένης βενζαλδεΰδης και του θειογλυκολικού οξέος. Επιπλέον της «κλασσικής» μεθόδου, πραγματοποιήθηκε ανάπτυξη ενός βελτιωμένου πρωτοκόλλου σύνθεσης σε περιβάλλον μικροκυμάτων, με ελαχιστοποίηση του απαιτούμενου χρόνου της αντίδρασης, καθώς και αύξηση της απόδοσης και της καθαρότητας των ενώσεων.Η ταυτοποίηση των προϊόντων πραγματοποιήθηκε με τη χρήση φασματοσκοπικών μεθόδων (IR, 1H-NMR, 13C-NMR και MS για μερικά παράγωγα). Πραγματοποιήθηκε in vitro μελέτη της ανασταλτικής δράσης των νέων ενώσεων επί της HIV-1 RT με την χρησιμοποίηση τόσο της ανοσοενζυμικής χρωματομετρικής, όσο και της ραδϊοισοτοπικής μεδόδου. Τέλος, λόγω της ουσιώδους σημασίας των αντιμικροβιακών φαρμάκων για τη θεραπεία πολλών μικροβιακών λοιμώξεων σε άτομα με ανοσοκαταστολή, όπως στους πάσχοντες από AIDS, πραγματοποιήθηκαν in vitro δοκιμασίες για να ελεγχθεί η αντιμικροβιακή δράση των ενώσεων, ακολοθούμενες απο in silico μελέτες πρόσδεσης (Docking) για την εξακρίβωση του πιθανού μηχανισμού αντιμικροβιακής δράσης τους

Thiazole Ring—A Biologically Active Scaffold

Background: Thiazole is a good pharmacophore nucleus due to its various pharmaceutical applications. Its derivatives have a wide range of biological activities such as antioxidant, analgesic, and antimicrobial including antibacterial, antifungal, antimalarial, anticancer, antiallergic, antihypertensive, anti-inflammatory, and antipsychotic. Indeed, the thiazole scaffold is contained in more than 18 FDA-approved drugs as well as in numerous experimental drugs. Objective: To summarize recent literature on the biological activities of thiazole ring-containing compounds Methods: A literature survey regarding the topics from the year 2015 up to now was carried out. Older publications were not included, since they were previously analyzed in available peer reviews. Results: Nearly 124 research articles were found, critically analyzed, and arranged regarding the synthesis and biological activities of thiazoles derivatives in the last 5 years