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The brain is a vulnerable metabolic organ and must adapt to different fuel conditions to sustain function. Nerve terminals are a locus of this vulnerability, but how they regulate ATP synthesis as fuel conditions vary is unknown. We show that synapses can switch from glycolytic to oxidative metabolism, but to do so, they rely on activity-driven presynaptic mitochondrial Ca2+ uptake to accelerate ATP production. We demonstrate that, whereas mitochondrial Ca2+ uptake requires elevated extramitochondrial Ca2+ in non-neuronal cells, axonal mitochondria readily take up Ca2+ in response to small changes in external Ca2+. We identified the brain-specific protein MICU3 as a critical driver of this tuning of Ca2+ sensitivity. Ablation of MICU3 renders axonal mitochondria similar to non-neuronal mitochondria, prevents acceleration of local ATP synthesis, and impairs presynaptic function under oxidative conditions. Thus, presynaptic mitochondria rely on MICU3 to facilitate mitochondrial Ca2+ uptake during activity and achieve metabolic flexibility.

Introduction: The levels and distribution of amyloid deposits in the brain does not correlate well with Alzheimer's disease (AD) progression. Therefore, it is likely thatamyloid precursor protein and its proteolytic fragments other than amyloid b (Ab) contribute to the onset of AD. Methods: We developed a sensitive assay adapted to the detection of C99, the direct precursor of b-amyloid. Three postmortem groups were studied: control with normal and stable cognition; patients with moderate AD, and individuals with severe AD. The amount of C99 and A beta was quantified and correlated with the severity of AD. Results: C99 accumulates in vulnerable neurons, and its levels correlate with the degree of cognitive impairment in patients suffering from AD. In contrast, A beta levels are increased in both vulnerable and resistant brain areas. Discussion: These results raise the possibility that C99, rather than A beta plaques, is responsible for the death of nerve cells in AD.

Fungal pathogens need to contend with stresses including oxidants and antimicrobial chemicals resulting from host defenses. ChAP1 of Cochliobolus heterostrophus, agent of Southern corn leaf blight, encodes an ortholog of yeast YAP1. ChAP1 is retained in the nucleus in response to plant-derived phenolic acids, in addition to its well-studied activation by oxidants. Here, we used transcriptome profiling to ask which genes are regulated in response to ChAP1 activation by ferulic acid (FA), a phenolic abundant in the maize host. Nuclearization of ChAP1 in response to phenolics is not followed by strong expression of genes needed for oxidative stress tolerance. We, therefore, compared the transcriptomes of the wild-type pathogen and a ChAP1 deletion mutant, to study the function of ChAP1 in response to FA. We hypothesized that if ChAP1 is retained in the nucleus under plant-related stress conditions yet in the absence of obvious oxidant stress, it should have additional regulatory functions. The transcriptional signature in response to FA in the wild type compared to the mutant sheds light on the signaling mechanisms and response pathways by which ChAP1 can mediate tolerance to ferulic acid, distinct from its previously known role in the antioxidant response. The ChAP1-dependent FA regulon consists mainly of two large clusters. The enrichment of transport and metabolism-related genes in cluster 1 indicates that C. heterostrophus degrades FA and removes it from the cell. When this fails at increasing stress levels, FA provides a signal for cell death, indicated by the enrichment of cell death-related genes in cluster 2. By quantitation of survival and by TUNEL assays, we show that ChAP1 promotes survival and mitigates cell death. Growth rate data show a time window in which the mutant colony expands faster than the wild type. The results delineate a transcriptional regulatory pattern in which ChAP1 helps balance a survival response for tolerance to FA, against a pathway promoting cell death in the pathogen. A general model for the transition from a phase where the return to homeostasis dominates to a phase leading to the onset of cell death provides a context for understanding these findings.

LINE-1 retrotransposon overexpression is a hallmark of human cancers. We identified a colorectal cancer wherein a fast-growing tumor subclone downregulated LINE-1, prompting us to examine how LINE-1 expression affects cell growth. We find that nontransformed cells undergo a TP53-dependent growth arrest and activate interferon signaling in response to LINE-1. TP53 inhibition allows LINE-1(+) cells to grow, and genome-wide-knockout screens show that these cells require replication-coupled DNA-repair pathways, replication-stress signaling and replication-fork restart factors. Our findings demonstrate that LINE-1 expression creates specific molecular vulnerabilities and reveal a retrotransposition-replication conflict that may be an important determinant of cancer growth. Knockout screens to assess the effect of LINE-1 expression on cell growth show that TP53-deficient cells require replication-stress signaling and replication-fork restart factors to suppress LINE-1 toxicity, and that LINE-1 expression activates the Fanconi anemia pathway, suggesting that retrotransposition conflicts with DNA replication.

Understanding the molecular mechanisms of endogenous and environmental metabolites is crucial for basic biology and drug discovery. With the genome, proteome, and metabolome of many organisms being readily available, researchers now have the opportunity to dissect how key metabolites regulate complex cellular pathways in vivo. Nonetheless, characterizing the specific and functional protein targets of key metabolites associated with specific cellular phenotypes remains a major challenge. Innovations in chemical biology are now poised to address this fundamental limitation in physiology and disease. In this review, we highlight recent advances in chemoproteomics for targeted and proteome-wide analysis of metabolite-protein interactions that have enabled the discovery of unpredicted metabolite-protein interactions and facilitated the development of new small molecule therapeutics.

Background: A needs assessment for patients with hidradenitis suppurativa (HS) will support advancements in multidisciplinary care, treatment, research, advocacy, and philanthropy. Objective: To evaluate unmet needs from the perspective of HS patients. Methods: Prospective multinational survey of patients between October 2017 and July 2018. Results: Before receiving a formal HS diagnosis, 63.7% (n = 827) of patients visited a physician >= 5 times. Mean delay in diagnosis was 10.2 6 8.9 years. Patients experienced flare daily, weekly, or monthly in 23.0%, 29.8%, and 31.1%, respectively. Most (61.4% [n = 798]) rated recent HS-related pain as moderate or higher, and 4.5% described recent pain to be the worst possible. Access to dermatology was rated as difficult by 37.0% (n = 481). Patients reported visiting the emergency department and hospital >= 5 times for symptoms in 18.3% and 12.5%, respectively. An extreme impact on life was reported by 43.3% (n = 563), and 14.5% were disabled due to disease. Patients reported a high frequency of comorbidities, most commonly mood disorders. Patients were dissatisfied with medical or procedural treatments in 45.9% and 34.6%, respectively. Limitations: Data were self-reported. Patients with more severe disease may have been selected. Conclusion: HS patients have identified several critical unmet needs that will require stakeholder collaboration to meaningfully address.

Aldehyde dehydrogenase type 2 (ALDH2), a key enzyme in ethanol metabolism, processes toxic acetaldehyde to nontoxic acetate. ALDH2 deficiency affects 8% of the world population and 35-45% of East Asians. The ALDH2*2 allele common genetic variant has a glutamic acid-to-lysine substitution at position 487 (E487K) that reduces the oxidizing ability of the enzyme resulting in systemic accumulation of acetaldehyde with ethanol ingestion. With chronic ethanol ingestion, mutations in ALDH2 are associated with a variety of hematological, neurological, and dermatological abnormalities, and an increased risk for esophageal cancer and osteoporosis. Based on our prior studies demonstrating that a one-time administration of an adeno-associated virus (AAV) serotype rh.10 gene transfer vector expressing the human ALDH2 cDNA (AAVrh.10hALDH2) prevents the acute effects of ethanol administration (the "Asian flush syndrome"), we hypothesized that AAVrh.10hALDH2 would also prevent the chronic disorders associated with ALDH2 deficiency and chronic ethanol ingestion. To assess this hypothesis, AAVrh.10hALDH2 (10(11) genome copies) was administered intravenously to two models of ALDH2 deficiency, Aldh2 knockout homozygous (Aldh2(-/-)) and knockin homozygous (Aldh2(E487K+/+)) mice (n = 10 per group). Four weeks after vector administration, mice were given drinking water with 10-15% ethanol for 12 weeks. Strikingly, compared with nonethanol drinking littermates, AAVrh.10hALDH2 administration prevented chronic ethanol-induced serum acetaldehyde accumulation and elevated liver malondialdehyde levels, loss of body weight, reduced hemoglobin levels, reduced performance in locomotor activity tests, accumulation of esophageal DNA damage and DNA adducts, and development of osteopenia. AAVrh.10hALDH2 should be considered as a preventative therapy for the increased risk of chronic disorders associated with ALDH2 deficiency and chronic alcohol exposure.

ClinicalTrials.gov is used by clinicians and patients to identify clinical trials; however, finding a relevant trial can be challenging. We evaluated the ease with which key information about a trial for patients with lymphoma could be derived from the title. We performed 2 searches for lymphoma trials on ClinicalTrials.gov, 1 before and 1 after a major overhaul of the website in 2017. Despite the overhaul, the study titles continued to lack the information needed to understand and select an appropriate clinical trial. Background: ClinicalTrials.gov is used by clinicians and patients to identify clinical trials. We assessed the ease with which users could identify relevant trials related to lymphoma using the short and official titles. We hypothesized that lymphoma titles frequently lack important information. Materials and Methods: We performed 2 searches on ClinicalTrials.gov. The first search was performed before June 2017, when ClinicalTrials.gov underwent updates to improve usability. The second was performed after 2017. We assessed whether the short and official titles of each trial provided information on the study phase, eligible disease status, lymphoma histologic subtype, study intervention, primary objective, and the presence of randomization and placebo control. Results: Of the pre-overhaul lymphoma trials, the official versus short titles included information regarding study intervention (99% vs. 96%), study phase (82% vs. 14%), lymphoma histologic subtype (78% vs. 72%), disease status (46% vs. 35%), randomization (13% vs. 2%), presence of placebo (6% vs. 2%), and primary objective (38% vs. 26%). Of the post-overhaul trials, the official versus short titles included information regarding study intervention (97% vs. 96%), lymphoma histologic subtype (83% vs. 78%), study phase (78% vs. 8%), disease status (64% vs. 50%), primary objective (38% vs. 23%), presence of placebo (11% vs. 0%), and randomization (18% vs. 0%). Conclusion: The official titles were more informative than were the short titles on ClinicalTrials.gov. However, the short and official titles both often lacked the basic information needed to understand a clinical trial. This has persisted despite updates to the platform. These results highlight the need for standardization of the format and content included in study titles. (C) 2019 Elsevier Inc. All rights reserved.

Infections with any of the nine human herpes viruses (HHV) can be asymptomatic or life-threatening. The study of patients with severe diseases caused by HHVs, in the absence of overt acquired immunodeficiency, has led to the discovery or diagnosis of various inborn errors of immunity. The related inborn errors of adaptive immunity disrupt alpha/beta T-cell rather than B-cell immunity. Affected patients typically develop HHV infections in the context of other infectious diseases. However, this is not always the case, as illustrated by inborn errors of SAP-dependent T-cell immunity to EBV-infected B cells. The related inborn errors of innate immunity disrupt leukocytes other than T and B cells, non-hematopoietic cells, or both. Patients typically develop only a single type of infection due to HHV, although, again, this is not always the case, as illustrated by inborn errors of TLR3 immunity resulting in HSV 1 encephalitis in some patients and influenza pneumonitis in others. Most severe HHV infections in otherwise healthy patients remains unexplained. The forward human genetic dissection of isolated and syndromic HHV-driven illnesses will establish the molecular and cellular basis of protective immunity to HHVs, paving the way for novel diagnosis and management strategies.