Construction of a genomic DNA library from Pantoea agglomerans strain CU0119 and screening against the plant pathogen Erwinia amylovora yielded a new family of antibiotics, dapdiamides A−E (1−5). The structures were established through 2D-NMR experiments and mass spectrometry, as well as the synthesis of dapdiamide A (1). Transposon mutagenesis of the active cosmid allowed identification of the biosynthetic gene cluster. The dapdiamide family’s promiscuous biosynthetic pathway contains two unconventional amide ligases that are predicted to couple its constituent monomers.

Diagnosing and monitoring recovery of patients with mild traumatic brain injury (mTBI) is challenging because of the lack of objective, quantitative measures. Diagnosis is based on description of injuries often not witnessed, subtle neurocognitive symptoms, and neuropsychological testing. Since working memory (WM) is at the center of cognitive functions impaired in mTBI, this study was designed to define objective quantitative electroencephalographic (qEEG) measures of WM processing that may correlate with cognitive changes associated with acute mTBI. First-time mTBI patients and mild peripheral (limb) trauma controls without head injury were recruited from the emergency department. WM was assessed by a continuous performance task (N-back). EEG recordings were obtained during N-back testing on three occasions: within five days, two weeks, and one month after injury. Compared with controls, mTBI patients showed abnormal induced and evoked alpha activity including event-related desynchronization (ERD) and synchronization (ERS). For induced alpha power, TBI patients had excessive frontal ERD on their first and third visit. For evoked alpha, mTBI patients had lower parietal ERD/ERS at the second and third visits. These exploratory qEEG findings offer new and non-invasive candidate measures to characterize the evolution of injury over the first month, with potential to provide much-needed objective measures of brain dysfunction to diagnose and monitor the consequences of mTBI.

BackgroundLipids are a primary storage form of energy and the source of inflammatory and pain signaling molecules, yet knowledge of their importance in chronic migraine (CM) pathology is incomplete. We aim to determine if plasma and cerebrospinal fluid (CSF) lipid metabolism are associated with CM pathology.MethodsWe obtained plasma and CSF from healthy controls (CT, n = 10) or CM subjects (n = 15) diagnosed using the International Headache Society criteria. We measured unesterified fatty acid (UFA) and esterified fatty acids (EFAs) using gas chromatography-mass spectrometry. Glycerophospholipids (GP) and sphingolipid (SP) levels were determined using LC-MS/MS, and phospholipase A2 (PLA2) activity was determined using fluorescent substrates.ResultsUnesterified fatty acid levels were significantly higher in CM plasma but not in CSF. Unesterified levels of five saturated fatty acids (SAFAs), eight monounsaturated fatty acids (MUFAs), five ω-3 polyunsaturated fatty acids (PUFAs), and five ω-6 PUFAs are higher in CM plasma. Esterified levels of three SAFAs, eight MUFAs, five ω-3 PUFAs, and three ω-6 PUFAs, are higher in CM plasma. The ratios C20:4n-6/homo-γ-C20:3n-6 representative of delta-5-desaturases (D5D) and the elongase ratio are lower in esterified and unesterified CM plasma, respectively. In the CSF, the esterified D5D index is lower in CM. While PLA2 activity was similar, the plasma UFA to EFA ratio is higher in CM. Of all plasma GP/SPs detected, only ceramide levels are lower (p = 0.0003) in CM (0.26 ± 0.07%) compared to CT (0.48 ± 0.06%). The GP/SP proportion of platelet-activating factor (PAF) is significantly lower in CM CSF.ConclusionsPlasma and CSF lipid changes are consistent with abnormal lipid metabolism in CM. Since plasma UFAs correspond to diet or adipose tissue levels, higher plasma fatty acids and UFA/EFA ratios suggest enhanced adipose lipolysis in CM. Differences in plasma and CSF desaturases and elongases suggest altered lipid metabolism in CM. A lower plasma ceramide level suggests reduced de novo synthesis or reduced sphingomyelin hydrolysis. Changes in CSF PAF suggest differences in brain lipid signaling pathways in CM. Together, this pilot study shows lipid metabolic abnormality in CM corresponding to altered energy homeostasis. We propose that controlling plasma lipolysis, desaturases, elongases, and lipid signaling pathways may relieve CM symptoms.

Background and ObjectivesLipids are the source of signaling and inflammatory molecules that may contribute to trauma pathology. Accordingly, we examined levels of lipid species and a lipolytic enzyme activity in a one‐month longitudinal study of acute mild traumatic brain injury (mTBI).MethodsWe recruited mTBI patients (n=21) and non‐head trauma controls (CT, n=9), aged 18–50 years from the emergency department of the Huntington Memorial Hospital (Pasadena, CA). Symptom progression was observed within days of injury (W1), and four weeks thereafter (W4). Plasma lipids collected at W1 and W4 were extracted and unesterified (UFA) and esterified fatty acids (EFA) quantified using negative ion/chemical ionization gas chromatography/mass spectrometry. Plasma glycerophospholipids (GP) and sphingolipids (SP) were analyzed using liquid chromatography‐tandem mass spectrometry. Plasma phospholipase A2 (PLA2) activity was determined using a fluorescence‐based activity assay.ResultsmTBI participants' plasma at W1 had higher levels of 24 UFA species that included seven saturated fatty acids (SAFA), seven monounsaturated fatty acids (MUFA), four omega‐3, and six omega‐6 polyunsaturated fatty acids (PUFA). The sum of all SAFAs, MUFAs, omega‐3 PUFAs, omega‐6 PUFAs, and PUFAs were higher in mTBI plasma at W1. For EFA at W1, two omega‐6 (homo‐g‐C20:3n‐6, C22:4n‐6), one omega‐3 (C20:5n‐3), the sum of omega‐3 PUFAs, and the omega‐3 to omega‐6 ratios (omega‐3 index) were lower in mTBI than in CT. At W4, esterified C19:0 and C22:3n‐3 levels were lower while C24:1 was higher in mTBI compared with CT. The UFA to EFA ratio that estimates endogenous lipolysis of fatty acids was higher in mTBI than CT for three SAFAs, two MUFAs, two omega‐6, two omega‐3, and the ratio of the sum of UFAs to the sum EFAs. Calcium‐dependent PLA2 activity was higher in mTBI plasma at W1 but not at W4. mTBI PLA2 activity at W1 positively correlated with most UFA species except C18:2n‐6 and C18:3n‐6 but correlated only with two UFA (C20:1, C22:1) in CT. PLA2 activity negatively correlated with seven EFA species.ConclusionsOur data showing higher UFA, UFA to EFA ratios, and correlation of UFA with PLA2 indicate excessive lipolysis in early mTBI. A lower omega‐3 index suggests the excessive oxidative breakdown of omega‐3 in mTBI. We propose that early intervention using strategies that reduce lipolysis may attenuate tissue damage linked to mTBI. Additionally, measurements of fatty acid fluctuations may be useful in discovering new therapies and monitoring resolution of mTBI.Support or Funding InformationFinancial support provided by the D.O.D. grant W81XWH‐13‐1‐0005. Thao Tran, David Strickland, Betty Chung, Darlene Royal, and David Buennagel assisted with data collection and patient recruitment.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Background and ObjectivesWe aim to explore blood plasma levels of matrix metalloproteinase‐9 (MMP9) in acute mild traumatic brain injury (mTBI), and test if MMP9 levels correlate with quantitative electroencephalography (qEEG) during working memory (WM) testing.MethodsStudy participants were recruited from the emergency department of Huntington Memorial Hospital in Pasadena, CA, consisting of thirteen acute mTBI civilian patients and seven controls who were trauma patients without head injury ranging between 18–50 years of age. Blood samples were collected from three time points: within 1 week, 14 days, and 30 days after the injury. To study blood‐brain‐barrier (BBB) integrity, we quantified three MMP9 peptides (SLGPALLLLQK, QLSLPETGELDSATLK, and LGLGADVAQVTGALR) using liquid chromatography and mass spectrometry with stable isotope standards. We also employed qEEG at each visit to investigate alpha frequency power during N‐back WM processing.Results & DiscussionWe detected the presence of all three MMP9 peptides in blood plasma. We observed that MMP9 peptide levels in both mTBI and controls were decreasing in abundance in the 2–4 weeks after injury compared to the first week. Importantly, the MMP9 levels of the LGLGADVAQVTGALR peptide but not the peptides from the pre‐protein, were significantly higher in the mTBI group 2–4 weeks after the injury, consistent with known “secondary injury” phenomena. MMP9 levels correlated with alpha power during WM testing, at the first visit for the controls but not for the mTBI patients, at specific brain regions during different WM load. Elevated MMP9 levels indicate the BBB integrity is compromised acutely after mTBI. The correlations between MMP9 and alpha power during WM that we only found in the trauma controls need further investigation.Support or Funding InformationThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.