Salmonella Typhimurium impairs glycolysismediated acidification of phagosomes to evade macrophage defense

Regulation of cellular metabolism is now recognized as a crucial mechanism for the activation of innate and adaptive immune cells upon diverse extracellular stimuli. Macrophages, for instance, increase glycolysis upon stimulation with pathogen-associated molecular patterns (PAMPs). Conceivably, pathogens also counteract these metabolic changes for their own survival in the host. Despite this dynamic interplay in host-pathogen interactions, the role of immunometabolism in the context of intracellular bacterial infections is still unclear. Here, employing unbiased metabolomic and transcriptomic approaches, we investigated the role of metabolic adaptations of macrophages upon Salmonella enterica serovar Typhimurium (S. Typhimurium) infections. Importantly, our results suggest that S. Typhimurium abrogates glycolysis and its modulators such as insulin-signaling to impair macrophage defense. Mechanistically, glycolysis facilitates glycolytic enzyme aldolase A mediated v- ATPase assembly and the acidification of phagosomes which is critical for lysosomal degradation. Thus, impairment in the glycolytic machinery eventually leads to decreased bacterial clearance and antigen presentation in murine macrophages (BMDM). Collectively, our results highlight a vital molecular link between metabolic adaptation and phagosome maturation in macrophages, which is targeted by S. Typhimurium to evade cell-autonomous defense. Copyright

Micro-Tensile Dentin Bond Strength of Two All-in-One Adhesives and an Etch-and-Rinse Adhesive

Svrha: Istraživanjem se željela ocijeniti mikrozatezna čvrstoća dentinske veze dvaju jednokomponentnih adhezivnih sustava te jednoga koji se jetka i ispire. Ispitanici i postupak: Zubi su bili nasumce podijeljeni u tri skupine kako bi se ispitali u postupku sa sljedećim adhezivnim sustavima: Adhese One®, Futurabond M® i Adper Singlebond® (kontrola). Zbog toga su korijeni i apikalni dio dna pulpne komore bili uklonjeni mikrotomom. Nakon toga su nadogradnje rezane okomito u pravokutne (≈1mm x 1mm) štapiće, te su oni testirani - uz konstantnu brzinu glave (1mm/min) - na univerzalnom stroju za ispitivanje čvrstoće. Na taj je način bio ispitan svaki adhezivni sustav. Dobilo se petnaest uzoraka i testiran je bio svaki materijal povezan s dentinom. Frakturirane površine pregledane su kako bi se odredila vrsta oštećenja. Rezultati: Čvrstoća veze Adhese One (5,83±3,13 MPa) bila je znatno niža nego Futurabonda M (15,76±4,2 MPa) (p:0,0001) i Adper Singlebonda (21,14±5,04 MPa) (p:0,0001). Također je čvrstoća veze Futurabonda M bila statistički mnogo niža nego Adper Singlebonda (p:0,003). Zaključak: Ispitani jednokomponentni adhezivni sustavi pokazali su manju zateznu čvrstoću dentinske veze nego onaj s jetkanjem i ispiranjem.Aim: The purpose of the present study is to evaluate the micro-tensile bond strength to dentin of two all-in-one adhesives and an etch-and-rinse adhesive. Material and Methods: The teeth were randomly divided into three groups for treatment with one of the following adhesives: Adhese One®, Futurabond M® and Adper Singlebond® (control). Roots and the apical floor of pulp chambers were removed with a microtome. The build-ups were vertically sectioned into rectangular (≈1mmx 1mm) compound bars with microtome. The bars were submitted to tensile tests at constant crosshead speed (1mm/min) using a universal testing machine and tested for each adhesive. Fifteen specimens were manufactured and tested for each material for permanent dentin. Fractured surfaces were inspected to determine the mode of fracture. Results: The bond strengths of Adhese One (5,83±3,13 MPa) was significantly lower than Futurabond M (15,76±4,2 MPa) (p:0,0001) and Adper Singlebond (21,14±5,04 MPa) (p:0,0001) while dentin bond strenght of Futurabond M was significantly lower than that of Adper Singlebond (p:0,003). Conclusions: The tested all-in-one adhesives showed lower dentin bond strengths than an etch-and-rinse adhesive

Rap1 regulates hematopoietic stem cell survival and affects oncogenesis and response to chemotherapy

Khattar, E., Maung, K.Z.Y., Chew, C.L. et al. Rap1 regulates hematopoietic stem cell survival and affects oncogenesis and response to chemotherapy. Nat Commun 10, 5349 (2019). https://doi.org/10.1038/s41467-019-13082-

The transcriptional program, functional heterogeneity, and clinical targeting of mast cells

Mast cells are unique tissue-resident immune cells that express an array of receptors that can be activated by several extracellular cues, including antigen-immunoglobulin E (IgE) complexes, bacteria, viruses, cytokines, hormones, peptides, and drugs. Mast cells constitute a small population in tissues, but their extraordinary ability to respond rapidly by releasing granule-stored and newly made mediators underpins their importance in health and disease. In this review, we document the biology of mast cells and introduce new concepts and opinions regarding their role in human diseases beyond IgE-mediated allergic responses and antiparasitic functions. We bring to light recent discoveries and developments in mast cell research, including regulation of mast cell functions, differentiation, survival, and novel mouse models. Finally, we highlight the current and future opportunities for therapeutic intervention of mast cell functions in inflammatory diseases.Gökhan Cildir, Harshita Pant, Angel F. Lopez, Vinay Tergaonka

3D-printed microplate inserts for long term high-resolution imaging of live brain organoids

Background: Organoids are a reliable model used in the study of human brain development and under pathological conditions. However, current methods for brain organoid culture generate tissues that range from 0.5 to 2mm of size, which need to be constantly agitated to allow proper oxygenation. The culture conditions are, therefore, not suitable for whole-brain organoid live imaging, required to study developmental processes and disease progression within physiologically relevant time frames (i.e. days, weeks, months). Results: Here we designed 3D-printed microplate inserts adaptable to standard 24 multi-well plates, which allow the growth of multiple organoids in pre-defined and fixed XYZ coordinates. This innovation facilitates highresolution imaging of whole-cerebral organoids, allowing precise assessment of organoid growth and morphology, as well as cell tracking within the organoids, over long periods. We applied this technology to track neocortex development through neuronal progenitors in brain organoids, as well as the movement of patient-derived glioblastoma stem cells within healthy brain organoids. Conclusions: This new bioengineering platform constitutes a significant advance that permits long term detailed analysis of whole-brain organoids using multimodal inverted fluorescence microscopy.Mariana Oksdath Mansilla, Camilo Salazar-Hernandez, Sally L. Perrin, Kaitlin G. Scheer, Gökhan Cildir, John Toubia, Kristyna Sedivakova, Melinda N. Tea, Sakthi Lenin, Elise Ponthier, Erica C. F. Yeo, Vinay Tergaonkar, Santosh Poonnoose, Rebecca J. Ormsby, Stuart M. Pitson, Michael P. Brown, Lisa M. Ebert, and Guillermo A. Gome

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery