Blood biomarkers for neonatal hypoxic-ischemic encephalopathy in the presence and absence of sentinel events
JOURNAL OF PERINATOLOGY
Authors: Broni, Eric K.; Eke, Ahizechukwu C.; Vaidya, Dhananjay; Tao, Xueting; Northington, Frances J.; Everett, Allen D.; Graham, Ernest M.
Abstract
Objective To determine if neonatal serum biomarkers representing different pathways of injury differ for cases of HIE of unknown cause to gain insight into timing and mechanism of injury. Study design In this cohort of all neonates with HIE admitted to our NICU, newborns with sentinel events were compared to those without during the 1st 3 days of life. Discard neonatal blood during the 1st 3 days of life was used for analysis. Results Of 277 babies with HIE treated with whole-body hypothermia, 190 (68.6%) had blood available for biomarker analysis. In total, 71 (37.4%) were born within our system, and 119 (62.6%) were transferred in from outside hospitals. Of these babies, 77 (40.5%) had a sentinel event and 113 (59.6%) had no sentinel event. Although the degree of metabolic acidosis was similar, repeated measures analysis showed that during the initial 3 days of life neonates born with HIE in the absence of sentinel events had 41.4% decreased VEGF (p = 0.027) and 62.5% increased IL-10 serum concentrations (p = 0.005). Conclusion These changes indicate that neonatal HIE in the absence of sentinel events is not related to an unrecognized acute intrapartum event and is possibly related to chronic hypoxia of lower severity or recovery from a remote event.
Lysosomal acid lipase is the major acid retinyl ester hydrolase in cultured human hepatic stellate cells but not essential for retinyl ester degradation
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS
Authors: Wagner, Carina; Hois, Victoria; Pajed, Laura; Pusch, Lisa-Maria; Wolinski, Heimo; Trauner, Michael; Zimmermann, Robert; Taschler, Ulrike; Lass, Achim
Abstract
Vitamin A is stored as retinyl esters (REs) in lipid droplets of hepatic stellate cells (HSCs). To date, two different pathways are known to facilitate the breakdown of REs: (i) Hydrolysis of REs by neutral lipases, and (ii) whole lipid droplet degradation in autolysosomes by acid hydrolysis. In this study, we evaluated the contribution of neutral and acid RE hydrolases to the breakdown of REs in human HSCs. (R)-Bromoenol lactone (R-BEL), inhibitor of adipose triglyceride lipase (ATGL) and patatin-like phospholipase domain-containing 3 (PNPLA3), the hormone-sensitive lipase (HSL) inhibitor 76-0079, as well as the serine-hydrolase inhibitor Orlistat reduced neutral RE hydrolase activity of LX-2 cell-lysates between 20 and 50%. Interestingly, in pulse-chase experiments, R-BEL, 76-0079, as well as Orlistat exerted little to no effect on cellular RE breakdown of LX-2 cells as well as primary human HSCs. In contrast, Lalistat2, a specific lysosomal acid lipase (LAL) inhibitor, virtually blunted acid in vitro RE hydrolase activity of LX-2 cells. Accordingly, HSCs isolated from LAL-deficient mice showed RE accumulation and were virtually devoid of acidic RE hydrolase activity. In pulse-chase experiments however, LAL-deficient HSCs, similar to LX-2 cells and primary human HSCs, were not defective in degrading REs. In summary, results demonstrate that ATGL, PNPLA3, and HSL contribute to neutral RE hydrolysis of human HSCs. LAL is the major acid RE hydrolase in HSCs. Yet, LAL is not limiting for RE degradation under serum-starvation. Together, results suggest that RE breakdown of HSCs is facilitated by (a) so far unknown, non-Orlistat inhibitable RE-hydrolase(s).