The effects of acute and chronic administration of phosphatidylserine on cell proliferation and survival in the dentate gyrus of adult and middle-aged rats

Longitudinal spatial mapping of lipid metabolites reveals pre-symptomatic changes in the hippocampi of Huntington's disease transgenic mice

In Huntington's disease (HD), a key pathological feature includes the development of inclusion-bodies of fragments of the mutant huntingtin protein in the neurons of the striatum and hippocampus. To examine the molecular changes associated with inclusion-body formation, we applied MALDI-mass spectrometry imaging and deuterium pulse labelling to determine lipid levels and synthesis rates in the hippocampus of a transgenic mouse model of HD (R6/1 line). The R6/1 HD mice lacked inclusions in the hippocampus at 6 weeks of age (pre-symptomatic), whereas inclusions were pervasive by 16 weeks of age (symptomatic). Hippocampal subfields (CA1, CA3 and DG), which formed the highest density of inclusion formation in the mouse brain showed a reduction in the relative abundance of neuron-enriched lipids that have roles in neurotransmission, synaptic plasticity, neurogenesis, and ER-stress protection. Lipids involved in the adaptive response to ER stress (phosphatidylinositol, phosphatidic acid, and ganglioside classes) displayed increased rates of synthesis in HD mice relative to WT mice at all the ages examined, including prior to the formation of the inclusion bodies. Our findings, therefore, support a role for ER stress occurring pre-symptomatically and potentially contributing to pathological mechanisms underlying HD.

Effects of Post-natal Dietary Milk Fat Globule Membrane Polar Lipid Supplementation on Motor Skills, Anxiety, and Long-Term Memory in Adulthood

Early life nutrition critically impacts post-natal brain maturation and cognitive development. Post-natal dietary deficits in specific nutrients, such as lipids, minerals or vitamins are associated with brain maturation and cognitive impairments. Specifically, polar lipids (PL), such as sphingolipids and phospholipids, are important cellular membrane building blocks and are critical for brain connectivity due to their role in neurite outgrowth, synaptic formation, and myelination. In this preclinical study, we assessed the effects of a chronic supplementation with a source of PL extracted from an alpha-lactalbumin enriched whey protein containing 10% lipids from early life (post-natal day (PND) 7) to adulthood (PND 72) on adult motor skills, anxiety, and long-term memory. The motor skills were assessed using open field and rotarod test. Anxiety was assessed using elevated plus maze (EPM). Long-term object and spatial memory were assessed using novel object recognition (NOR) and Morris water maze (MWM). Our results suggest that chronic PL supplementation improved measures of spatial long-term memory accuracy and cognitive flexibility in the MWM in adulthood, with no change in general mobility, anxiety and exploratory behavior. Our results indicate memory specific functional benefits of long-term dietary PL during post-natal brain development.

The impact of quetiapine on the brain lipidome in a cuprizone-induced mouse model of schizophrenia

The antipsychotic effect of Quetiapine (Que) has been extensively studied and growing evidence suggests that Que has a beneficial effect, improving cognitive functions and promoting myelin repair. However, the effects of Que on the brain lipidome and the association between Que-associated cognitive improvement and changes in lipids remain elusive. In the present study, we assessed the cognitive protective effects of Que treatment and used a mass spectrometry-based lipidomic approach to evaluated changes in lipid composition in the hippocampus, prefrontal cortex (PFC), and striatum in a mouse model of cuprizone (CPZ)-induced demyelination. CPZ induces cognitive impairment and remarkable lipid changes in the brain, specifically in lipid species of glycerophospholipids and sphingolipids. Moreover, the changes in lipid classes of the PFC were more extensive than those observed in the hippocampus and striatum. Notably, Que treatment ameliorated cuprizone-induced cognitive impairment and partly normalized CPZ-induced lipid changes. Taken together, our data suggest that Que may rescue cognitive behavioral changes from CPZ-induced demyelination through modulation of the brain lipidome, providing new insights into the pharmacological mechanism of Que for schizophrenia.

Lipidomics Reveals the Therapeutic Effects of EtOAc Extract of Orthosiphon stamineus Benth. on Nephrolithiasis

Background

Nephrolithiasis is a systemic metabolic disease with a high prevalence worldwide and is closely related to lipid-mediated oxidative stress and inflammation. Orthosiphon stamineus Benth. (OS) is a traditional medicinal herb mainly containing flavonoids, caffeic acid derivatives, and terpenoids, which has the effect of treating urinary stones. However, the active ingredients of OS for the treatment of kidney stones and their regulatory mechanisms remain unknown. As a powerful antioxidant, flavonoids from herbs can mitigate calcium oxalate stone formation by scavenging radical. Thus, this work focused on EtOAc extract of OS (EEOS, mainly flavonoids) and aimed to reveal the potential intrinsic mechanism of EEOS in the treatment of kidney stones disease.

Methods

Firstly, 75% ethanol extract of OS was further extracted with EtOAc to obtain EtOAc extract containing 88.82% flavonoids. Secondly, the extract was subjected to component analysis and used in animal experiments. Then, an untargeted lipidomics based on ultrahigh performance liquid chromatography coupled with TripleTOF 5600 mass spectrometer (UPLC-QTOF-MS) was performed to test the lipid changes of kidneys in the control group, model group and EEOS treatment groups. Finally, multivariate statistical analysis was used to identify differences between the lipid profiles of mice in the model group and the EEOS group.

Results

Fifty-one lipid metabolites were significantly different between the mice in the model group and the EEOS intervention group, including glycerophosphocholines, glycerophosphoethanolamines, glycerophosphoinositols, and glycerophosphoglycerols. And the composition of glycerophospholipids-esterified ω-3 polyunsaturated fatty acids and glycerophospholipid subclasses in the kidneys of the EEOS group significantly changed compared to model group.

Conclusions

The EEOS can inhibit the stones formation by improving oxidative stress and inflammation mediated by glycerophospholipid metabolism. This study reveals the potential mechanism of EEOS for kidney stones treatment at the lipid molecule level, providing a new direction for further study of the efficacy of OS.

Lateral Cerebellar Nucleus Stimulation has Selective Effects on Glutamatergic and GABAergic Perilesional Neurogenesis After Cortical Ischemia in the Rodent Model

BACKGROUND

Chronic deep brain stimulation of the rodent lateral cerebellar nucleus (LCN) has been demonstrated to enhance motor recovery following cortical ischemia. This effect is concurrent with synaptogenesis and expression of long-term potentiation markers in the perilesional cerebral cortex.

OBJECTIVE

To further investigate the cellular changes associated with chronic LCN stimulation in the ischemic rodent by examining neurogenesis along the cerebellothalamocortical pathway.

METHODS

Rats were trained on the pasta matrix task, followed by induction of cortical ischemia and electrode implantation in the contralesional LCN. Electrical stimulation was initiated 6 wk after stroke induction and continued for 4 wk prior to sacrifice. Neurogenesis was examined using immunohistochemistry.

RESULTS

Treated animals showed enhanced performance on the pasta matrix task relative to sham controls. Increased cell proliferation colabeled with 5'-Bromo-2'-deoxyuridine and neurogenic markers (doublecortin) was observed in the perilesional cortex as well as bilateral mediodorsal and ventrolateral thalamic subnuclei in treated vs untreated animals. The neurogenic effect at the level of motor cortex was selective, with stimulation-treated animals showing greater glutamatergic neurogenesis but significantly less GABAergic neurogenesis.

CONCLUSION

These findings suggest that LCN deep brain stimulation modulates postinjury neurogenesis, providing a possible mechanistic foundation for the associated enhancement in poststroke motor recovery.

Glycerophospholipid Supplementation as a Potential Intervention for Supporting Cerebral Structure in Older Adults

Modifying nutritional intake through supplementation may be efficacious for altering the trajectory of cerebral structural decline evident with increasing age. To date, there have been a number of clinical trials in older adults whereby chronic supplementation with B vitamins, omega-3 fatty acids, or resveratrol, has been observed to either slow the rate of decline or repair cerebral tissue. There is also some evidence from animal studies indicating that supplementation with glycerophospholipids (GPL) may benefit cerebral structure, though these effects have not yet been investigated in adult humans. Despite this paucity of research, there are a number of factors predicting poorer cerebral structure in older humans, which GPL supplementation appears to beneficially modify or protect against. These include elevated concentrations of homocysteine, unbalanced activity of reactive oxygen species both increasing the risk of oxidative stress, increased concentrations of pro-inflammatory messengers, as well as poorer cardio- and cerebrovascular function. As such, it is hypothesized that GPL supplementation will support cerebral structure in older adults. These cerebral effects may influence cognitive function. The current review aims to provide a theoretical basis for future clinical trials investigating the effects of GPL supplementation on cerebral structural integrity in older adults.

Phosphatidylserine improves axonal transport by inhibition of HDAC and has potential in treatment of neurodegenerative diseases

Familial dysautonomia (FD) is a rare children neurodegenerative disease caused due to a point mutation in the IKBKAP gene that results in decreased IKK complex-associated protein (IKAP) protein production. The disease affects mostly the dorsal root ganglion (DRG) and the sympathetic ganglion. Recently, we found that the molecular mechanisms underlying neurodegeneration in FD patients are defects in axonal transport of nerve growth factors and microtubule stability in the DRG. Neurons are highly polarized cells with very long axons. In order to survive and maintain proper function, neurons depend on transport of proteins and other cellular components from the neuronal body along the axons. We further demonstrated that IKAP is necessary for axon maintenance and showed that phosphatidylserine acts as an HDAC6 inhibitor to rescue neuronal function in FD cells. In this review, we will highlight our latest research findings.

Phosphatidylserine Ameliorates Neurodegenerative Symptoms and Enhances Axonal Transport in a Mouse Model of Familial Dysautonomia

Familial Dysautonomia (FD) is a neurodegenerative disease in which aberrant tissue-specific splicing of IKBKAP exon 20 leads to reduction of IKAP protein levels in neuronal tissues. Here we generated a conditional knockout (CKO) mouse in which exon 20 of IKBKAP is deleted in the nervous system. The CKO FD mice exhibit developmental delays, sensory abnormalities, and less organized dorsal root ganglia (DRGs) with attenuated axons compared to wild-type mice. Furthermore, the CKO FD DRGs show elevated HDAC6 levels, reduced acetylated α-tubulin, unstable microtubules, and impairment of axonal retrograde transport of nerve growth factor (NGF). These abnormalities in DRG properties underlie neuronal degeneration and FD symptoms. Phosphatidylserine treatment decreased HDAC6 levels and thus increased acetylation of α-tubulin. Further PS treatment resulted in recovery of axonal outgrowth and enhanced retrograde axonal transport by decreasing histone deacetylase 6 (HDAC6) levels and thus increasing acetylation of α-tubulin levels. Thus, we have identified the molecular pathway that leads to neurodegeneration in FD and have demonstrated that phosphatidylserine treatment has the potential to slow progression of neurodegeneration.

We create a novel FD mouse model, in which exon 20 of IKBKAP was deleted in the nervous system, to study the role of IKAP in the neurodegeneration process. The lack of IKBKAP exon 20 impaired retrograde nerve growth factor (NGF) transport and axonal outgrowth. Reduction of IKAP levels resulted in elevated HDAC6 levels and thus reduced acetylated α-tubulin levels. Phosphatidylserine down-regulated HDAC6 levels, furthermore phosphatidylserine treatment facilitated axonal transport and stabilized microtubules. In brief: Naftelberg et al. identify the molecular pathway leading to neurodegeneration using a mouse model of familial dysautonomia and suggest that phosphatidylserine acts as an HDAC6 inhibitor to improve neurologic function.