Youngmonroe0167

Published by PNAS.Cells can rapidly adapt to changing environments through nongenetic processes; however, the metabolic cost of such adaptation has never been considered. Here we demonstrate metabolic coupling in a remarkable, rapid adaptation process (1 in 1,000 cells adapt per hour) by simultaneously measuring metabolism and division of thousands of individual Saccharomyces cerevisiae cells using a droplet microfluidic system droplets containing single cells are immobilized in a two-dimensional (2D) array, with osmotically induced changes in droplet volume being used to measure cell metabolism, while simultaneously imaging the cells to measure division. Following a severe challenge, most cells, while not dividing, continue to metabolize, displaying a remarkably wide diversity of metabolic trajectories from which adaptation events can be anticipated. Adaptation requires a characteristic amount of energy, indicating that it is an active process. The demonstration that metabolic trajectories predict a priori adaptation events provides evidence of tight energetic coupling between metabolism and regulatory reorganization in adaptation. This process allows S. cerevisiae to adapt on a physiological timescale, but related phenomena may also be important in other processes, such as cellular differentiation, cellular reprogramming, and the emergence of drug resistance in cancer.The intestinal epithelium acts as a barrier between the organism and its microenvironment, including the gut microbiota. It is the most rapidly regenerating tissue in the human body thanks to a pool of intestinal stem cells (ISCs) expressing Lgr5 The intestinal epithelium has to cope with continuous stress linked to its digestive and barrier functions. Epithelial repair is crucial to maintain its integrity, and Lgr5-positive intestinal stem cell (Lgr5+ISC) resilience following cytotoxic stresses is central to this repair stage. We show here that autophagy, a pathway allowing the lysosomal degradation of intracellular components, plays a crucial role in the maintenance and genetic integrity of Lgr5+ISC under physiological and stress conditions. Using conditional mice models lacking the autophagy gene Atg7 specifically in all intestinal epithelial cells or in Lgr5+ISC, we show that loss of Atg7 induces the p53-mediated apoptosis of Lgr5+ISC. Mechanistically, this is due to increasing oxidative stress, alterations to interactions with the microbiota, and defective DNA repair. Following irradiation, we show that Lgr5+ISC repair DNA damage more efficiently than their progenitors and that this protection is Atg7 dependent. Accordingly, we found that the stimulation of autophagy on fasting protects Lgr5+ISC against DNA damage and cell death mediated by oxaliplatin and doxorubicin treatments. GSK'872 manufacturer Finally, p53 deletion prevents the death of Atg7-deficient Lgr5+ISC but promotes genetic instability and tumor formation. Altogether, our findings provide insights into the mechanisms underlying maintenance and integrity of ISC and highlight the key functions of Atg7 and p53.Grapevine fanleaf virus (GFLV) is a picorna-like plant virus transmitted by nematodes that affects vineyards worldwide. Nanobody (Nb)-mediated resistance against GFLV has been created recently, and shown to be highly effective in plants, including grapevine, but the underlying mechanism is unknown. Here we present the high-resolution cryo electron microscopy structure of the GFLV-Nb23 complex, which provides the basis for molecular recognition by the Nb. The structure reveals a composite binding site bridging over three domains of one capsid protein (CP) monomer. The structure provides a precise mapping of the Nb23 epitope on the GFLV capsid in which the antigen loop is accommodated through an induced-fit mechanism. Moreover, we uncover and characterize several resistance-breaking GFLV isolates with amino acids mapping within this epitope, including C-terminal extensions of the CP, which would sterically interfere with Nb binding. Escape variants with such extended CP fail to be transmitted by nematodes linking Nb-mediated resistance to vector transmission. Together, these data provide insights into the molecular mechanism of Nb23-mediated recognition of GFLV and of virus resistance loss.AIDS is a pandemic disease caused by HIV that affects 37 million people worldwide. Current antiretroviral therapy slows disease progression but does not eliminate latently infected cells, which resupply active virus, thus necessitating lifelong treatment with associated compliance, cost, and chemoexposure issues. Latency-reversing agents (LRAs) activate these cells, allowing for their potential clearance, thus presenting a strategy to eradicate the infection. Protein kinase C (PKC) modulators-including prostratin, ingenol esters, bryostatin, and their analogs-are potent LRAs in various stages of development for several clinical indications. While LRAs are promising, a major challenge associated with their clinical use is sustaining therapeutically meaningful levels of the active agent while minimizing side effects. Here we describe a strategy to address this problem based on LRA prodrugs, designed for controllable release of the active LRA after a single injection. As intended, these prodrugs exhibit comparable or superior in vitro activity relative to the parent compounds. Selected compounds induced higher in vivo expression of CD69, an activation biomarker, and, by releasing free agent over time, significantly improved tolerability when compared to the parent LRAs. More generally, selected prodrugs of PKC modulators avoid the bolus toxicities of the parent drug and exhibit greater efficacy and expanded tolerability, thereby addressing a longstanding objective for many clinical applications.While several studies have shown that hypoxic preconditioning suppresses development of the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS), no one has yet examined the important clinically relevant question of whether mild hypoxia can impact the progression of preexisting disease. Using a relapsing-remitting model of EAE, here we demonstrate that when applied to preexisting disease, chronic mild hypoxia (CMH, 10% O2) markedly accelerates clinical recovery, leading to long-term stable reductions in clinical score. At the histological level, CMH led to significant reductions in vascular disruption, leukocyte accumulation, and demyelination. Spinal cord blood vessels of CMH-treated mice showed reduced expression of the endothelial activation molecule VCAM-1 but increased expression of the endothelial tight junction proteins ZO-1 and occludin, key mechanisms underlying vascular integrity. Interestingly, while equal numbers of inflammatory leukocytes were present in the spinal cord at peak disease (day 14 postimmunization; i.