Long-chain omega-3 polyunsaturated fatty acids are reduced in neonates with substantial brain injury undergoing therapeutic hypothermia after hypoxic-ischemic encephalopathy.

Hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal morbidity and mortality. Although therapeutic hypothermia is an effective treatment, substantial chronic neurological impairment often persists. The long-chain omega-3 polyunsaturated fatty acids (PUFAs), docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids, offer therapeutic potential in the post-acute phase. To understand how PUFAs are affected by HIE and therapeutic hypothermia we quantified for the first time the effects of HIE and therapeutic hypothermia on blood PUFA levels and lipid peroxidation. In a cross-sectional approach, blood samples from newborns with moderate to severe HIE, who underwent therapeutic hypothermia (sHIE group) were compared to samples from newborns with mild HIE, who did not receive therapeutic hypothermia, and controls. The sHIE group was stratified into cerebral MRI predictive of good (n = 10), or poor outcomes (n = 10; nine developed cerebral palsy). Cell pellets were analyzed for fatty acid content, and plasma for lipid peroxidation products, thiobarbituric acid reactive substances and 4-hydroxy-2-nonenal. Omega-3 Index (% DHA + EPA) was similar between control and HIE groups; however, with therapeutic hypothermia there were significantly lower levels in poor vs. good prognosis sHIE groups. Estimated Δ-6 desaturase activity was significantly lower in sHIE compared to mild HIE and control groups, and linoleic acid significantly increased in the sHIE group with good prognosis. Reduced long-chain omega-3 PUFAs was associated with poor outcome after HIE and therapeutic hypothermia, potentially due to decreased biosynthesis and tissue incorporation. We speculate a potential role for long-chain omega-3 PUFA interventions in addition to existing treatments to improve neurologic outcomes in sHIE.

Alterations in the Stool Microbiome in Newborns Undergoing Mild Therapeutic Hypothermia after Hypoxic-Ischemic Encephalopathy.

BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) is associated with brain injury in newborns and may lead to disability or death. Mild therapeutic hypothermia (TH) is an effective neuroprotective intervention and an established standard of care in western countries. The gut microbiome, the genomic and physicochemical contribution of the gut microbiota, serves important functions and is increasingly recognized as a major influencer on development. The impact of HIE and TH on the evolving gut microbiota of the newborn remains to be elucidated. OBJECTIVE: The objective of this study was to carry out an exploratory study on the effects of HIE and TH on the gut microbiome in term neonates. METHODS AND RESULTS: Stool samples were obtained from 28 newborns with HIE (median age 68 h) undergoing TH on the neonatal unit (HIE TH group), with a follow-on stool sample available for 20 of these babies (median age 151 h). For comparison, a single stool specimen was obtained from 19 healthy newborns on the postnatal ward (median age 34 h). The microbiota composition was determined using established microbial DNA extraction and 16S rRNA gene sequencing methodology. There was no difference in the mode of delivery or the method of feeding the newborns, once established, between the 2 groups. All the infants in the HIE TH group had received antibiotics compared to only one of the controls. A lower α-diversity, quantified by the Shannon diversity index, was noted in the microbiota of the HIE TH group in comparison to the control group. The HIE TH group had a higher mean relative abundance (MRA) of facultative anaerobes and aerobes such as Staphylococcus species and a lower MRA of strict anaerobes, such as members of the Bacteroides genus, compared to the control. Also, there was a significant reduction in the MRA of the genus Bifidobacterium in the HIE TH group. Although the mode of delivery exerts a profound influence on the gut microbiota of the newborn, distance-based redundancy analysis showed that TH may exert an independent influence. This study could not determine the independent contribution of the use of antibiotics or the neonatal intensive care unit environment. CONCLUSION: In this study, we demonstrate an alteration in the microbiota composition in newborns undergoing TH for HIE.

Nutritional Supplementation Reduces Lesion Size and Neuroinflammation in a Sex-Dependent Manner in a Mouse Model of Perinatal Hypoxic-Ischemic Brain Injury.

Perinatal hypoxia-ischemia (HI) is a major cause of neonatal brain injury, leading to long-term neurological impairments. Medical nutrition can be rapidly implemented in the clinic, making it a viable intervention to improve neurodevelopment after injury. The omega-3 (n-3) fatty acids docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3), uridine monophosphate (UMP) and choline have previously been shown in rodents to synergistically enhance brain phospholipids, synaptic components and cognitive performance. The objective of this study was to test the efficacy of an experimental diet containing DHA, EPA, UMP, choline, iodide, zinc, and vitamin B12 in a mouse model of perinatal HI. Male and female C57Bl/6 mice received the experimental diet or an isocaloric control diet from birth. Hypoxic ischemic encephalopathy was induced on postnatal day 9 by ligation of the right common carotid artery and systemic hypoxia. To assess the effects of the experimental diet on long-term motor and cognitive outcome, mice were subjected to a behavioral test battery. Lesion size, neuroinflammation, brain fatty acids and phospholipids were analyzed at 15 weeks after HI. The experimental diet reduced lesion size and neuroinflammation specifically in males. In both sexes, brain n-3 fatty acids were increased after receiving the experimental diet. The experimental diet also improved novel object recognition, but no significant effects on motor performance were observed. Current data indicates that early life nutritional supplementation with a combination of DHA, EPA, UMP, choline, iodide, zinc, and vitamin B12 may provide neuroprotection after perinatal HI.

Lipid profiling of brain tissue and blood after traumatic brain injury: A review of human and experimental studies.

Traumatic brain injury (TBI) is a neurological condition which affects a large number of individuals worldwide, across all ages. It can lead to major physical, cognitive and psychological impairment, and represents a considerable health cost burden. TBI is a heterogeneous condition and there has been intense effort over the last decade to identify better biomarkers, which would enable an optimum and personalized treatment. The brain is highly enriched in a variety of lipids, including fatty acids, glycerophospholipids, glycerolipids, sterols and sphingolipids. There is accumulating evidence in clinical studies in TBI patients and also in experimental models of TBI, that injury triggers a complex pattern of changes in various lipid classes. Such changes can be detected in blood (plasma/serum), cerebrospinal fluid and also in brain tissue. They provide new insights into the pathophysiology of TBI, and have biomarker potential. Here, we review the various changes reported and discuss the scope and value of these lipid focused studies within the TBI field.

Long-Chain Polyunsaturated Fatty Acids and Lipid Peroxidation Products in Donor Human Milk in the United Kingdom: Results From the LIMIT 2-Centre Cross-Sectional Study.

BACKGROUND: Donor human milk (DHM) is used as alternative to maternal milk to feed preterm infants; however, it may provide less long-chain (LC) polyunsaturated fatty acids (PUFAs) and more oxidized lipids, which may be detrimental to preterm infant health and development. Levels have not been reported for DHM in the United Kingdom. METHODS: DHM (n = 19) from 2 neonatal units, preterm milk from a neonatal unit (n = 10), and term milk from the community (n = 11) were analyzed for fatty acids, malondialdehyde, 4-hydroxy-2-nonenal, and hexanal. STUDY REGISTRATION: NCT03573531. RESULTS: DHM had significantly lower absolute LCPUFA content than term (P < .001) and significantly lower ω-3 PUFAs than preterm milk (P < .05), although relative LCPUFA composition did not differ. Exclusive DHM feeding leads to significantly lower fat (3.7 vs 6.7 g/d) and LCPUFA (docosahexaenoic acid [DHA]: 10.6 vs 16.8 mg/d; arachidonic acid [ARA]: 17.4 vs 25.2 mg/d) intake than recommended by the European Society for Pediatric Gastroenterology, Hepatology and Nutrition, and provides 17.3% and 43.1% of the in utero accreted ARA and DHA. DHM had the highest proportion of lipid peroxidation. CONCLUSIONS: This study confirms that DHM in the United Kingdom has insufficient LCPUFAs for preterm infants. It demonstrates for the first time that DHM has the highest level of lipid peroxidation, compared with preterm or term milk. This has important implications for preterm infant nutrition, as exclusive DHM feeding might not be suitable long term and may contribute to the development of major preterm neonatal morbidities.

The effects of storage conditions on long-chain polyunsaturated fatty acids, lipid mediators, and antioxidants in donor human milk - A review.

Donor human milk (DHM) is the recommended alternative, if maternal milk is unavailable. However, current human milk banking practices may negatively affect the nutritional quality of DHM. This review summarises the effects of these practices on polyunsaturated fatty acids, lipid mediators and antioxidants of human milk. Overall, there is considerable variation in the reported effects, and further research is needed, particularly with lipid mediators and antioxidants. However, to preserve nutritional quality, DHM should be protected from light exposure and storage at 4 °C minimised, to prevent decreases in vitamin C and endocannabinoids and increases in free fatty acids and lipid peroxidation products. Storage at -20 °C prior to pasteurisation should also be minimised, to prevent free fatty increases and total fat and endocannabinoid decreases. Storage ≤-70 °C is preferable wherever possible, although post-pasteurisation storage at -20 °C for three months appears safe for free fatty acids, lipid peroxidation products, and total fat content.

Myeloid DLL4 Does Not Contribute to the Pathogenesis of Non-Alcoholic Steatohepatitis in Ldlr-/- Mice.

Non-alcoholic steatohepatitis (NASH) is characterized by liver steatosis and inflammation. Currently, the underlying mechanisms leading to hepatic inflammation are not fully understood and consequently, therapeutic options are poor. Non-alcoholic steatohepatitis (NASH) and atherosclerosis share the same etiology whereby macrophages play a key role in disease progression. Macrophage function can be modulated via activation of receptor-ligand binding of Notch signaling. Relevantly, global inhibition of Notch ligand Delta-Like Ligand-4 (DLL4) attenuates atherosclerosis by altering the macrophage-mediated inflammatory response. However, the specific contribution of macrophage DLL4 to hepatic inflammation is currently unknown. We hypothesized that myeloid DLL4 deficiency in low-density lipoprotein receptor knock-out (Ldlr-/-) mice reduces hepatic inflammation. Irradiated Ldlr-/- mice were transplanted (tp) with bone marrow from wild type (Wt) or DLL4f/fLysMCre+/0 (DLL4del) mice and fed either chow or high fat, high cholesterol (HFC) diet for 11 weeks. Additionally, gene expression was assessed in bone marrow-derived macrophages (BMDM) of DLL4f/fLysMCreWT and DLL4f/fLysMCre+/0 mice. In contrast to our hypothesis, inflammation was not decreased in HFC-fed DLL4del-transplanted mice. In line, in vitro, there was no difference in the expression of inflammatory genes between DLL4-deficient and wildtype bone marrow-derived macrophages. These results suggest that myeloid DLL4 deficiency does not contribute to hepatic inflammation in vivo. Since, macrophage-DLL4 expression in our model was not completely suppressed, it can't be totally excluded that complete DLL4 deletion in macrophages might lead to different results. Nevertheless, the contribution of non-myeloid Kupffer cells to notch signaling with regard to the pathogenesis of steatohepatitis is unknown and as such it is possible that, DLL4 on Kupffer cells promote the pathogenesis of steatohepatitis.