Nieman et al. Blueberries, Bananas, Exercise, Oxylipins In summary, heavy exertion evoked a transient but robust increase in plasma levels of oxylipins in cyclists, with a strong attenuation effect linked to both chronic blueberry and acute banana intake on pro-inflammatory ARA-CYP oxylipins.

IntroductionOxylipins are bioactive oxidation products derived from n-6 and n-3 polyunsaturated fatty acids (PUFAs) in the linoleic acid and α-linolenic desaturation pathways.PurposeThis study determined if carbohydrate intake during prolonged and intensive cycling countered post-exercise increases in n-6 and n-3 PUFA-derived oxylipins.MethodsThe research design utilized a randomized, crossover, counterbalanced approach with cyclists (N = 20, overnight fasted state, 7:00 am start) who engaged in four 75-km time trials while ingesting two types of bananas (Cavendish, Mini-yellow), a 6% sugar beverage, and water only. Carbohydrate intake was set at 0.2 g/kg every 15 minutes, and blood samples were collected pre-exercise and 0 h-, 0.75 h-,1.5 h-, 3 h-, 4.5 h-, 21 h-, 45 h-post-exercise. Oxylipins were measured with a targeted liquid chromatography-multiple reaction monitoring mass spectrometric method.ResultsSignificant time effects and substantial fold-increases (immediately post-exercise/pre-exercise) were measured for plasma levels of arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and 43 of 45 oxylipins. Significant interaction effects (4 trials x 8 time points) were found for plasma ARA (P<0.001) and DHA (P<0.001), but not EPA (P = 0.255), with higher post-exercise values found in the water trial compared to the carbohydrate trials. Significant interaction effects were also measured for 12 of 45 oxylipins. The data supported a strong exercise-induced increase in plasma levels of these oxylipins during the water trial, with carbohydrate ingestion (both bananas types and the sugar beverage) attenuating oxylipin increases, especially those (9 of 12) generated from the cytochrome P-450 (CYP) enzyme system. These trials differences were especially apparent within the first three hours of recovery from the 75-km cycling bout.ConclusionsProlonged and intensive exercise evoked a transient but robust increase in plasma levels of oxylipins, with a significant attenuation effect linked to acute carbohydrate ingestion for 28% of these, especially those generated through the CYP enzyme system.Trial registrationClinicalTrials.gov, U.S. National Institutes of Health, NCT02994628

Protein phosphorylation is an important modulator of many cellular processes, and identification of kinase substrates provides critical insights for signal transduction. However, this identification process is often difficult and many kinase substrates remain unexplored. Herein, a systematic proteomics approach solely depending on MS detection is reported for identifying substrates of PKA and PKG, which are suspected to have similar specificity determinants, in pregnant rat uteri. Instead of radioisotopes that are commonly used to couple with MS for substrate identification, this study developed an efficient in vitro kinase assay on depleted tissue homogenates to reveal substrate candidates directly by MS. To facilitate MS detection, exogenous phosphatases were added to remove intrinsic phosphorylation followed by a heating step to inactivate all enzymes. No observable interference caused by endogenous kinases or background phosphorylation was detected in the control experiment in which no kinase was externally added. A total of 61 and 12 substrate candidates were identified in vitro for PKA and PKG, respectively, and most of these identified sites contain consensus motifs of each kinase with only a few sites overlapped, indicating a good specificity. Moreover, differential phosphoproteomics analysis using stable isotope dimethyl labeling and MS was performed to detect the change of protein phosphorylation upon kinase stimulation in vivo. Four identified in vitro PKA substrates including three reported sites on HSP27 or filamin A were significantly phosphorylated in vivo, giving them high confidence as physiological substrates in pregnant rat uteri. Moreover, telokin, a known PKG substrate on S1880, and actin-binding proteins such as Arp 3, titin, and desmuslin were also identified to be in vitro PKG substrates in pregnant rat uteri. These proteins are all expected to be involved in the regulation of actin-mediated cytoskeletal remodeling.

Objectives: Recent metabolomic studies of sepsis showed that increased circulatory acylcarnitines were associated with worse survival. However, it is unknown whether plasma carnitine and acylcarnitines can reflect the severity of sepsis, and the role of specific acylcarnitines in prognostic assessment need further confirmation. This study aimed to clarify these questions. Design: Prospective multicenter cohort studies with derivation and validation cohort design. Setting: ICUs at two medical centers and three regional hospitals in Taiwan. Patients: Patients with sepsis and acute organ dysfunction were enrolled. Recruitment of the derivation (n = 90) and validation cohorts (n = 120) occurred from October 2010 through March 2012 and January 2013 through November 2014, respectively. Interventions: Plasma samples were collected immediately after admission, and the levels of carnitine and acylcarnitines were measured by ultra-high performance liquid chromatography-mass spectrometry. Measurements and Main Results: In the derivation cohort, increased plasma levels of short- and medium-chain acylcarnitines were significantly associated with hepatobiliary dysfunction, renal dysfunction, thrombocytopenia, and hyperlactatemia. However, acetylcarnitine is the only acylcarnitine significantly correlating with various plasma cytokine concentrations and also associated with blood culture positivity and 28-day mortality risk. The association between plasma acetylcarnitine and multiple organ dysfunction severity, blood culture positivity, and 28-day mortality, was confirmed in the validation cohort. Patients with high plasma acetylcarnitine (≥ 6,000 ng/mL) had significantly increased 28-day mortality compared with those with plasma acetylcarnitine less than 6,000 ng/mL (52.6% vs 13.9%; hazard ratio, 5.293; 95% CI, 2.340–11.975; p < 0.001 by Cox proportional hazard model). Conclusions: We confirm that plasma acetylcarnitine can reflect the severity of organ dysfunction, inflammation, and infection in sepsis and can serve as a prognostic biomarker for mortality prediction.

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