Choline Levels Research Articles

Epigenetic changes in pyloric caeca of Atlantic salmon fed diets containing increasing levels of lipids and choline

ABSTRACT An earlier study of ours investigating the effect of dietary lipid levels on the choline requirement of Atlantic salmon showed increasing severity of intestinal steatosis with increasing lipid levels. As choline is involved in epigenetic regulation by being the key methyl donor, pyloric caeca samples from the study were analysed for epigenetic effects of dietary lipid and choline levels. The diets varied in lipid levels between 16% and 28%, and choline levels between 1.9 and 2.3 g/kg. The diets were fed for 8 weeks to Atlantic salmon of 25 g of initial weight. Using reduced representation bisulfite sequencing (RRBS), this study revealed that increasing dietary lipid levels induced methylation differences in genes involved in membrane transport and signalling pathways, and in microRNAs important for the regulation of lipid homoeostasis. Increasing choline levels also affected genes involved in fatty acid biosynthesis and transport, lipolysis, and lipogenesis, as well as important immune genes. Our observations confirmed that choline is involved in epigenetic regulation in Atlantic salmon, as has been reported for higher vertebrates. This study showed the need for the inclusion of biomarkers of epigenetic processes in studies that must be conducted to define optimal choline levels in diets for Atlantic salmon.

Maternal dietary choline levels cause transcriptome shift due to genotype-by-diet interactions in rainbow trout (Oncorhynchus mykiss)

The objective of this study was to identify metabolic regulatory mechanisms affected by choline availability in rainbow trout (Oncorhynchus mykiss) broodstock diets associated with increased offspring growth performance. Three customized diets were formulated to have different levels of choline: (a) 0 % choline supplementation (Low Choline: 2065 ppm choline), (b) 0.6 % choline supplementation (Medium Choline: 5657 ppm choline), and (c) 1.2 % choline supplementation (High Choline: 9248 ppm choline). Six all-female rainbow trout families were fed experimental diets beginning 18 months post-hatch until spawning at 22 months post-hatch; their offspring were fed a commercial diet. Experimental broodstock diet did not affect overall choline, fatty acid, or amino acid content in the oocytes (p > 0.05), apart from tyrosine (p ≤ 0.05). Offspring body weights from the High and Low Choline diets did not differ from those in the Medium Choline diet (p > 0.05); however, family-by-diet and sire-by-diet interactions on offspring growth were detected (p ≤ 0.05). The High Choline diet did not improve growth performance in the six broodstock families at final harvest (520-days post-hatch, or dph). Numerous genes associated with muscle development and lipid metabolism were identified as affected by broodstock diet, including myosin, troponin C, and fatty acid binding proteins, which were associated with key signaling pathways of lipid metabolism, muscle cell development, muscle cell proliferation, and muscle cell differentiation. These findings indicate that supplementing broodstock diets with choline does regulate expression of genes related to growth and nutrient partitioning but does not lead to growth benefits in rainbow trout families selected for disease resistance.

Effects of Choline Supplementation in Diets on Juvenile Pacu (Piaractus mesopotamicus): Productive Performance, Proximate Composition and Serum Lipid Level.

Pacu (Piaractus mesopotamicus) is a Brazilian fish species of high commercial value and has emerged as one of the main species with potential for intensive farming. This study aimed to investigate the impact of choline supplementation on productive performance, visceral fat, hepatosomatic indices, proximate composition, serum biochemical profile, and liver coloration in juvenile pacu (Piaractus mesopotamicus). The 60-day experiment was conducted in the experimental hatchery of the Study Group of Aquaculture Management - GEMAq of the State University of West Paraná, Brazil. The completely randomized design consisted of five treatments with four replicates each. A total of 200 fish, with an average initial weight and length of 4.25 g and 5.97 cm, were distributed among 20 experimental hapas, resulting in a stocking density of 10 fish per experimental unit. Fish fed a choline-deficient diet exhibited the lowest values for final weight, weight gain, visceral fat, and hepatosomatic index. Conversely, in terms of proximate composition, fish fed choline-deficient diets had the highest moisture content but the lowest crude fat content. Triglyceride levels in juvenile pacu were significantly higher in groups fed diets containing choline (400 to 1200 mg kg-1 ). We also observed significant differences in the cyan color of the liver (P < 0.05). Notably, we observed significant differences in the cyan coloration of the liver (P < 0.05). Other parameters did not exhibit significant changes in response to varying choline levels in the diets. Our study demonstrated that choline supplementation in P. mesopotamicus juveniles at an optimal concentration of 400 mg kg-1 significantly impacted growth, metabolism, productive performance, proximate composition, biochemical parameters, and liver color. These findings offer crucial guidance for aquaculture professionals, enabling them to enhance growth and health in P. mesopotamicus farming. Further research on choline's influence on lipid metabolism holds potential for more precise dietary recommendations, ultimately improving the efficiency and sustainability of aquaculture practices for this species.

A Narrative Review on Maternal Choline Intake and Liver Function of the Fetus and the Infant; Implications for Research, Policy, and Practice.

Dietary choline is needed to maintain normal health, including normal liver function in adults. Fatty liver induced by a choline-deficient diet has been consistently observed in human and animal studies. The effect of insufficient choline intake on hepatic fat accumulation is specific and reversible when choline is added to the diet. Choline requirements are higher in women during pregnancy and lactation than in young non-pregnant women. We reviewed the evidence on whether choline derived from the maternal diet is necessary for maintaining normal liver function in the fetus and breastfed infants. Studies have shown that choline from the maternal diet is actively transferred to the placenta, fetal liver, and human milk. This maternal-to-child gradient can cause depletion of maternal choline stores and increase the susceptibility of the mother to fatty liver. Removing choline from the diet of pregnant rats causes fatty liver both in the mother and the fetus. The severity of fatty liver in the offspring was found to correspond to the severity of fatty liver in the respective mothers and to the duration of feeding the choline-deficient diet to the mother. The contribution of maternal choline intake in normal liver function of the offspring can be explained by the role of phosphatidylcholine in lipid transport and as a component of cell membranes and the function of choline as a methyl donor that enables synthesis of phosphatidylcholine in the liver. Additional evidence is needed on the effect of choline intake during pregnancy and lactation on health outcomes in the fetus and infant. Most pregnant and lactating women are currently not achieving the adequate intake level of choline through the diet. Therefore, public health policies are needed to ensure sufficient choline intake through adding choline to maternal multivitamin supplements.

3.0 T multi-parametric MRI reveals metabolic and microstructural abnormalities in the posterior visual pathways in patients with thyroid eye disease.

We aim to explore the microstructural and metabolic changes in visual pathways in patients with thyroid eye disease (TED) using 3T multi-parametric MRI. Thirty-four TED patients (inactive group = 20; active group = 14; acute group = 18; chronic group = 16) and 12 healthy controls (HC) were recruited from November 2020 to July 2021. Proton magnetic resonance spectroscopy (1H-MRS), glutamate chemical exchange saturation transfer (GluCEST) and diffusion kurtosis imaging (DKI) were performed on 3.0T MR scanner. Data analysis and group comparisons were performed after MR data processing. As compare to HC group, the levels of total choline (tCh) in optic radiation (OR) in active group ([1.404 ± 0.560] vs. [1.022 ± 0.260]; p < 0.05), together with tCh ([1.415 ± 0.507] vs. [1.022 ± 0.260]; p < 0.05) in OR in acute group were significantly increased. Glutamine (Gln) levels were higher in OR in the chronic group than those in HCs and were positively correlated with the levels of thyroglobulin antibody (TgAb), thyroid peroxidase antibody (TPOAb), free triiodothyronine (FT3) and FT4 in chronic group. Glutamate (Glu) levels by 1H-MRS did not show significant differences between any two groups. Interestingly, MTRasym (3.0 ppm) was higher in OL in inactive group, active group, acute group and chronic group than those in HCs, and was positively correlated with Glu levels in OL in 1H-MRS. Fractional anisotropy (FA) values from DKI in OR in acute group were significantly lower than those in HCs. Our initial study demonstrate that GluCEST performs better than 1H-MRS to monitor Glu alterations in visual pathway in TED patients. Changes of brain glutamine levels in TED patients are closely related to their associated hormones alterations, indicating that disease injury status could be reflected through non-invasive metabolites detection by brain 1H-MRS. FA is the most sensitive DKI index to reveal the visual pathway impairment in TED patients. Altogether, our study revealed that 3T multiparametric MR techniques are useful to demonstrate metabolic and microstructural alterations in visual pathways in TED patients. We found that damage to visual pathways occurs in mild TED cases, which not only offers a new approach to the diagnosis of dysthyroid optic neuropathy, but also demonstrates neuropathy in TED is a gradual and continuous spatio-emporal progression.

The diagnostic challenge of lack of choline level elevation on 1H-MR spectroscopy in grade II-III gliomas.

The accurate diagnosis of brain tumour is very important in modern neuro-oncology medicine. Magnetic resonance spectroscopy (MRS) is supposed to be a promising tool for detecting cancerous lesions. However, the interpretation of MRS data is complicated by the fact that not all cancerous lesions exhibit elevated choline (Cho) levels. The main goal of our study was to investigate the lack of Cho lesion /Cho ref elevation in the population of grade II-III gliomas. 89 cases of gliomas grade II and III were used for the retrospective analysis - glioma (astrocytoma or oligodendroglioma) grade II (74 out of 89 cases [83%]) and III (15 out of 89 cases [17%]) underwent conventional MRI extended by MRS before treatment. Histopathological diagnosis was obtained either by biopsy or surgical resection. Gliomas were classified to the group of no-choline elevation when the ratio of choline measured within the tumour (Cho lesion ) to choline from NABT (Cho ref ) were equal to or lower than 1. Significant differences were observed between ratios of Cho lesion /Cr lesion calculated for no-choline elevation and glial tumour groups as well as in the NAA lesion /Cr lesion ratio between the no-choline elevation group and glial tumour group. With consistent data concerning choline level elevation and slightly lower NAA value, the Cho lesion /NAA lesion ratio is significantly higher in the WHO II glial tumour group compared to the no-choline elevation cases ( p < 0.000). In the current study the results demonstrated possibility of lack of choline elevation in patients with grade II-III gliomas, so it is important to remember that the lack of elevated choline levels does not exclude neoplastic lesion.

Combined use of neuroprotective agents: A new treatment strategy for patients with glaucoma

Keywords: Glaucoma, Coenzyme Q10, Citicoline, Neuroprotection, Retinal ganglion cells.Glaucoma is a leading cause of irreversible blindness worldwide. Although the multifactorial genesis, by now, the main treatable risk factor is the elevated intraocular pressure. Nevertheless, some patients, whose intraocular pressure is considered at the target level, still experience a progression of the disease. New evidence strongly suggesting brain involvement in all aspects of the disease led to a growing interest in the pharmacological research of new neuroprotective agents with an intraocular pressure independent activity.Citicoline and coenzyme Q10 are among the most studied and used molecules in clinical practice for some forms of neurodegeneration. In particular, the neuromodulatory and neuroprotective properties of citicoline were extensively investigated either in vivo or in vitro studies. Among the activities of citicoline it has been proposed the capacity to increase neuronal viability as well as the vasomodulatory effect that results in an increased blood flow. Similarly, the neuroprotective effects of coenzyme Q10 has been proposed in experimental models of ocular neurodegeneration.The greater efficacy of the fixed combination over the single components could depend on the fact that each molecule exerts, at least in part, its activity on mitochondria. Coenzyme Q10 acts as an electron carrier from mitochondrial complexes I and II to III, while citicoline maintains proper levels of cardiolipin and sphingomyelin in the cellular and axon membranes. Thus, increasing the energetic rate of cells.Citicoline and coenzyme Q10 are reported to counteract excitotoxicity by respectively decreasing nitrosative stress and extracellular signal‐regulated kinases 1/2, and preventing the upregulation of NR1 and NR2A subunit receptors. In addition, coenzyme Q10 significantly prevents apoptosis by acting on Bax and pBad proteins expression and preserves mitochondrial DNA content and mitochondrial oxidative phosphorylation system in experimental models.Citicoline and coenzyme Q10 are also important in preventing retinal ganglion cells death possibly by acting on Bcl family regulation increasing retinal expression of Bcl‐2, and by significantly inducing Bcl‐xL protein expression, respectively.Citicoline and coenzyme Q10 also show an anti‐inflammatory effect; the first acting on inhibition of phospholipase A2 and downregulating synaptophysin, and the latter by downregulating tumour necrosis factor α and protein 1α, as well as acting on macrophage induced inflammation.Data on literature indicates that the combined use of molecules may be also beneficial for the metabolism of the molecules themselves. In fact, coenzyme Q10 increases the choline oxidase activity in ubiquinone‐depleted mitochondria, thus underling the importance of the presence of good plasmatic choline and coenzyme Q10 levels for energetic production.Overall, evidence seems to suggest the usefulness of coenzyme Q10 and citicoline, eventually combined, in the prevention of glaucomatous neurodegeneration.

Activation of a non-neuronal cholinergic system in visceral white adipose tissue of obese mice and humans

Background and objectivesSince white adipose tissue (WAT) lacks parasympathetic cholinergic innervation, the source of the acetylcholine (ACh) acting on white adipocyte cholinergic receptors is unknown. This study was designed to identify ACh-producing cells in mouse and human visceral WAT and to determine whether a non-neuronal cholinergic system becomes activated in obese inflamed WAT. MethodsMouse epididymal WAT (eWAT) and human omental fat were studied in normal and obese subjects. The expression of the key molecules involved in cholinergic signaling was evaluated by qRT-PCR and western blotting whereas their tissue distribution and cellular localization were investigated by immunohistochemistry, confocal microscopy and in situ hybridization. ACh levels were measured by liquid chromatography/tandem mass spectrometry. The cellular effects of ACh were assessed in cultured human multipotent adipose-derived stem cell (hMADS) adipocytes. ResultsIn mouse eWAT, diet-induced obesity modulated the expression of key cholinergic molecular components and, especially, raised the expression of choline acetyltransferase (ChAT), the ACh-synthesizing enzyme, which was chiefly detected in interstitial macrophages, in macrophages forming crown-like structures (CLSs), and in multinucleated giant cells (MGCs). The stromal vascular fraction of obese mouse eWAT contained significantly higher ACh and choline levels than that of control mice. ChAT was undetectable in omental fat from healthy subjects, whereas it was expressed in a number of interstitial macrophages, CLSs, and MGCs from some obese individuals. In hMADS adipocytes stressed with tumor necrosis factor α, ACh, alone or combined with rivastigmine, significantly blunted monocyte chemoattractant protein 1 and interleukin 6 expression, it partially but significantly, restored adiponectin and GLUT4 expression, and promoted glucose uptake. ConclusionsIn mouse and human visceral WAT, obesity induces activation of a macrophage-dependent non-neuronal cholinergic system that is capable of exerting anti-inflammatory and insulin-sensitizing effects on white adipocytes.

Elusive physiological role of prostatic acid phosphatase (PAP): generation of choline for sperm motility via auto-and paracrine cholinergic signaling.

Prostatic acid phosphatase (PAP) exists as two splice variants, secreted PAP and transmembrane PAP, the latter of which is implicated in antinociceptive signaling in dorsal root ganglia. However, PAP is predominantly expressed in the prostate gland and the physiological role of seminal PAP, first identified in 1938, is largely unknown. Here, the author proposes that PAP, following ejaculation, functions to hydrolyze phosphocholine (PC) in seminal fluid and generate choline, which is imported by sperm via a choline transporter and converted to acetylcholine (ACh) by choline acetyltransferase. Auto- and paracrine cholinergic signaling, or choline directly, may subsequently stimulate sperm motility via α7 nicotinic ACh receptors (nAChRs) and contractility of the female reproductive tract through muscarinic ACh receptors (mAChRs). Consistent with a role of PAP in cholinergic signaling, 1) seminal vesicles secrete PC, 2) the prostate gland secretes PAP, 3) PAP specifically catalyzes the hydrolysis of PC into inorganic phosphate and choline, 4) seminal choline levels increase post-ejaculation, 5) pharmacological inhibition of choline acetyltransferase inhibits sperm motility, 6) inhibition or genetic deletion of α7 nAChRs impairs sperm motility, and 7) mAChRs are expressed in the uterus and oviduct (fallopian tube). Notably, PAP does not degrade glycerophosphocholine (GPC), the predominant choline source in the semen of rats and other mammals. Instead, uterine GPC phosphodiesterases may liberate choline from seminal GPC. In summary, the author deduces that PAP in humans, and uterine GPC phosphodiesterases in other mammals, function to generate choline for sperm cholinergic signaling, which promotes sperm motility and possibly contractility of the female reproductive tract.

Evidence for genetic causal relationships between gut microbiome, metabolites, and myasthenia gravis: a bidirectional Mendelian randomization study.

Myasthenia gravis (MG) is an autoimmune disease observed to have connections with gut microbiome. We aimed to systematically assess the causal relationships between gut microbiome, gut microbiome-derived metabolites, and MG using Mendelian randomization (MR) approach. Summary-level genetic datasets from large-scale genome-wide association studies regarding 196 gut microbial taxa from the MiBioGen consortium (n=18,340), 72 derived metabolites from the TwinsUK and KORA studies (n=7,824), and antiacetylcholine receptor (AChR) antibody-positive MG (case=1,873, control=36,370) were employed for MR causal estimates. The inverse-variance weighted (IVW) method was utilized as the main analysis with MR-Egger, maximum likelihood, simple mode, and weighted median as complements. The tests of Cochran's Q, MR-Egger intercept, Steiger, MR-PRESSO and leave-one-out were implemented for sensitivity analyses. The forward MR estimates of IVW revealed significant causal associations of the abundance of phylum Actinobacteria, class Gammaproteobacteria, family Defluviitaleac, family Family XIII, and family Peptococcaceae with a reduced risk of MG. Conversely, the abundance of phylum Lentisphaerae, order Mollicutes RF9, order Victivallales, and genus Faecalibacterium was causally associated with an increased risk of MG. The reversed MR analysis proved negative causal correlations between the MG and the abundance of family Peptostreptococcaceae, genus Romboutsia, and genus Subdoligranulum. Regarding the derived metabolites, the IVW estimates revealed that elevated levels of beta-hydroxyisovalerate and methionine were causally associated with a decreased risk of MG, while increased levels of choline and kynurenine were linked to an increased risk of MG. Furthermore, genetically predicted MG was associated with a decreased level of cholesterol. The results obtained from complementary MR methods were similar. These findings remained robust in all sensitivity analyses. Our MR findings support the causal effects of specific gut microbiome taxa and derived metabolites on AChR antibody-positive MG, and vice versa, yielding novel insights into prevention and therapy targets of MG. Future studies may be warranted for validation and pursuing the precise mechanisms.

Bifidobacterium animalis subsp. lactis Probio-M8 alleviates abnormal behavior and regulates gut microbiota in a mouse model suffering from autism.

Probiotics can effectively improve a variety of neurological diseases, but there is little research on autism, and the specific mechanism is unclear. In this study, shotgun metagenomics analysis was used to investigate the preventive and therapeutic effects of Bifidobacterium animalis subsp. lactis Probio-M8 on autism. The results showed that Probio-M8 treatment significantly alleviated valproate (VPA)-induced autism in mice, with autistic symptoms characterized by increased stereotyped behaviors such as grooming, reduced learning ability, and decreased desire to socialize. Further studies have found that Probio-M8 can alleviate autism by optimizing gut microbiota diversity and regulating metabolic levels. Probio-M8 regulates gut microbiota structure by increasing the abundance of beneficial bacteria such as Bifidobacterium globosum and Akkermansia muciniphila. In addition, Probio-M8 regulates metabolic activity by increasing levels of choline, which corrects CAZy disorders. In conclusion, Probio-M8 is therapeutic in the VPA-induced autism mouse model by regulating the gut microbiome and metabolic levels.IMPORTANCEIndividuals with autism often exhibit symptoms of social invariance, obsessive-compulsive tendencies, and repetitive behaviors. However, early intervention and treatment can be effective in improving social skills and mitigating autism symptoms, including behaviors related to irritability. Although taking medication for autism may lead to side effects such as weight gain, probiotics can be an ideal intervention for alleviating these symptoms. In this study, we investigated the effects of Probio-M8 intervention on the behavior of autistic mice using an open-field test, a three-chamber sociability test, and a novel object recognition test. Metagenomic analysis revealed differences in gut microbiota diversity among groups, predicted changes in metabolite levels, and functionally annotated CAZy. Additionally, we analyzed serum neurotransmitter levels and found that probiotics were beneficial in mitigating neurotransmitter imbalances in mice with autism.

The association of serum choline concentrations with the risk of cancers: a community-based nested case–control study

Few studies have been designed to investigate the effect of serum choline on the risk of incident cancer. This study aims to explore the association between serum choline and the risk of new-onset cancer. We conducted a case–control study, including 199 patients with incident cancer and 199 matched controls during a median of 3.9 years of follow-up, nested within the China Stroke Primary Prevention Trial. Cubic spline regression (RCS) and conditional logistic regression analysis was used to assess the association of serum choline and incident cancer risk. We observed a positive dose–response association between serum choline levels and the risk of overall (p for overall = 0.046) and digestive system cancer (p for overall = 0.039). Compared with patients with the lowest choline levels (Q1 group), patients in the highest levels of choline (Q4) had a 3.69-fold and 6.01-fold increased risk of overall (OR = 3.69, 95% CI 1.17–11.63) and digestive system cancer (OR = 6.01, 95% CI 1.14–31.67). Elevated choline levels (per SD, 11.49 μg/mL) were associated with a higher risk of overall cancer among participants who were older, male, and smokers in the subgroup analyses. We found a positive association between elevated levels of serum choline with increased risk of incident cancer. Our findings have critical clinical implications for cancer prevention and diagnosis.Trial registration CSPPT, NCT00794885. Registered: November 20, 2008. https://www.clinicaltrials.gov/ct2/show/study/NCT00794885https://www.clinicaltrials.gov/ct2/show/study/NCT00794885.

Serum Trimethylamine N-Oxide, Choline, Betaine, and Carnitine levels among Coronary Artery Disease patients

Background and aimRecent studies have linked Trimethylamine N-oxide (TMAO) to cardiovascular diseases; our study aimed to analyze the association between coronary artery disease (CAD) and TMAO. MethodsPubMed, Scopus, Embase, and Web of Science were searched using terms; such as “CAD” and “TMAO”. Only observational controlled studies were included. RevMan software version 5.4 was used for the analysis. ResultsA significant association was found between the CAD group and increased serum TMAO levels compared with the control group (MD = 1.16, 95% CI = 0.54 to 1.78, p-value =0.0003). This association remained significant among acute coronary syndrome (ACS) patients (MD=0.98, 95% CI =0.73 to 1.23, p-value <0.00001) and was also detected among young and old CAD patients (MD = 0.35, 95% CI = 0.06 to 0.64, p-value = 0.02 and MD = 1.36, 95% CI = 0.71 to 2.01, p-value <0.0001, respectively). On further analysis of intestinal metabolites, we detected an insignificant association between choline, betaine, carnitine, and CAD. According to our sensitivity analysis, TMAO is an acceptable discriminatory marker for CAD (0.721, SE was 0.0816, 95% CI 0.561 to 0.881). ConclusionTMAO is an acceptable discriminatory marker for CAD, with significantly higher levels among these patients regardless of their age. Other metabolites didn't show such an association. The role of serum level TMAO in the early diagnosis of CAD should be further explored.

Mfsd7b facilitates choline transport and missense mutations affect choline transport function.

MFSD7b belongs to the Major Facilitator Superfamily of transporters that transport small molecules. Two isoforms of MFSD7b have been identified and they are reported to be heme exporters that play a crucial role in maintaining the cytosolic and mitochondrial heme levels, respectively. Mutations of MFSD7b (also known as FLVCR1) have been linked to retinitis pigmentosa, posterior column ataxia, and hereditary sensory and autonomic neuropathy. Although MFSD7b functions have been linked to heme detoxification by exporting excess heme from erythroid cells, it is ubiquitously expressed with a high level in the kidney, gastrointestinal tract, lungs, liver, and brain. Here, we showed that MFSD7b functions as a facilitative choline transporter. Expression of MFSD7b slightly but significantly increased choline import, while its knockdown reduced choline influx in mammalian cells. The influx of choline transported by MFSD7b is dependent on the expression of choline metabolizing enzymes such as choline kinase (CHKA) and intracellular choline levels, but it is independent ofgradient of cations. Additionally, we showed that choline transport function of Mfsd7b is conserved from fly to man. Employing our transport assays, we showed that missense mutations of MFSD7b caused reduced choline transport functions. Our results show that MFSD7b functions as a facilitative choline transporter in mammalian cells.

Acute and sub-acute metabolic change in different brain regions induced by moderate blunt traumatic brain injury.

The objective of the study was to observe the effect of moderate closed-head injury on hippocampal, thalamic, and striatal tissue metabolism with time. Closed head injury is responsible for metabolic changes. These changes can be permanent or temporary, depending on the injury's impact. For the experiment, 20 rats were randomly divided into four groups, each containing five animals. Animals were subjected to injury using a modified Marmarou's weight drop device; hippocampal, thalamic, and striatal tissue samples were collected after 1 day, 3 days, and 7 days of injury. NMR spectra were acquired following sample processing. Changes in myo-inositol, creatine, glutamate, succinate, lactate, and N-acetyl aspartic acid in hippocampal tissues were observed at day 3 PI. The tyrosine level in the hippocampus was altered at day 7 PI. While thalamic and striatal tissue samples showed altered levels of branched-chain amino acids and myo-inositol at day 1PI. Taurine, gamma amino butyric acid (GABA), choline, and alpha keto-glutarate levels were found to be significantly altered in striatal tissues at days 1 and 3PI. Acetate and GABA levels were altered in the thalamus on day 1 PI. The choline level in the thalamus was found to alter at all-time points after injury. The alteration in these metabolites may be due to the alteration in their respective pathways. Neurotransmitter and energy metabolism pathways were found to be altered in all three brain regions after TBI. This study may help better understand the effect of injury on the metabolic balance of a specific brain region and recovery.

Low circulating choline levels correlate with Alzheimer’s disease pathology severity and cognitive impairment

AbstractBackgroundModifiable environmental risk factors may help reduce Alzheimer’s disease (AD) incidence. Choline plays key roles in healthy body and brain function (Blusztajn, 1998) and supplementation above the adequate daily intake (ADI) reduces AD pathology (Velazquez et al., 2019). Choline deficiency increases AD risk and pathology (Dave et al., 2023; Yuan et al., 2022). Notably, recent reports estimate that ∼90% of Americans do not reach the ADI for dietary choline (Zeisel, 2017), making it imperative to better understand the link between choline and AD risk.MethodWe obtained serum samples from severe AD (AD‐Sev; Braak stage VI), moderate AD (AD‐Mod; Braak stage IV), and healthy control (CON; &lt; Braak stage III) subjects (n = 12/group; balanced for sex) from the Banner Sun Health Research Institute’s Brain and Body Donation Program. Cognitive test scores (Mini‐Mental State Examination (MMSE)), plaque burden, and Braak stage was characterized by Banner Sun Health. We assessed free choline, acetylcholine (ACh), and TNFα levels. Gas‐chromatography‐mass spectrometry was used to profile aqueous metabolites and short‐chain fatty acids.ResultThere were no significant group differences for post‐mortem interval (M = 3.79). We found disease associated differences, where AD‐Sev and AD‐Mod patients had lower levels of free choline and ACh, and higher levels of pro‐inflammatory cytokine TNFα, than CON. AD‐Mod showed a significant difference in all these measurements compared to AD‐Sev. Free choline and ACh were positively correlated to MMSE scores, whereas free choline and ACh levels were negatively correlated with total plaque and Braak Stage. Free choline and ACh were negatively correlated with TNFα. Metabolomics analysis revealed significant differences (p &lt; 0.05) in the metabolisms of beta‐alanine, linoleic acid, and of taurine and hypotaurine.ConclusionCollectively, as free choline and ACh levels decreased, AD pathology increased. Free choline was also associated with MMSE score. Increased TNFα was observed in cases with lower choline, illustrating increased inflammation. Together, this data expands on our recent (Dave et al., 2023) and others (Yuan et al., 2022) publications, highlighting links between low choline and AD risk.

Back‐translation of clinical tau‐aggregation inhibitor trials to experimental models: negative interactions of dementia therapies

AbstractBackgroundAlzheimer disease (AD) has attracted considerable interest in novel therapies. Two Phase III trials by TauRx Pharmaceuticals (TRx‐005, TRx‐015) failed to attain their endpoints. A significant number of recruits, however, remained on symptomatic treatment and a post‐hoc analysis confirmed this sub‐cohort was selectively resilient against the tau aggregation inhibitor hydromethylthionine (HMT; previously termed LMT). By contrast, drug‐naïve patients were highly sensitive to the novel therapy and showed little decline over 18‐month. We here back‐translated this study to the preclinic.MethodsExperiments used female tau transgenic Line 1 mice (L1) aged 6‐8 months previously characterised for cognitive impairments, tau pathology, and sensitivity to the tau aggregation inhibitor HMT. Here, multiple groups and doses of drugs were chronically administered (up to 11 weeks) with pre‐exposure to the acetylcholine esterase inhibitor rivastigmine followed by add‐on of HMT. Drugs were also dosed singly.Results(i) Tested for spatial learning in the water maze, L1 mice were significantly impaired and benefitted from exposure to HMT. By contrast, combination therapy with rivastigmine precluded some of the benefits of HMT while rivastigmine alone was non‐efficacious.(ii) Chronic drug administration was followed by tissue harvest and histological preparation of sections through 6 brain regions (3 x cortical, 3x basal forebrain) and labelling of 6 presynaptic structural (3) and functional proteins (3. Reduced protein levels were found in cortex; they were heightened by HMT, but abnormally altered in the presence of rivastigmine (single and combination therapy).(iii) Chronic drug administration was followed by in vivo brain dialysis from hippocampus for acetylcholine at rest and under behavioural challenge. L1 showed a lowering of cholinergic neurones in the basal forebrain, but no difference in acetylcholine levels at rest; a heightening of choline levels was observed to HMT alone at rest and challenge, but not to combinations with rivastigmine.ConclusionWe successfully back‐translate the clinical trials on HMT into the preclinic using L1 tau transgenic mice . Data suggest not only a reduced cognitive efficacy of HMT in subjects pre‐exposed to the choline esterase inhibitor rivastigmine, but also offer mechanistic explanations for potential interactions at presynaptic function and for transmitter release.

Design, synthesis, and biological evaluation of novel donepezil-tacrine hybrids as multi-functional agents with low neurotoxicity against Alzheimer’s disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and deficits in cognitive domains. Low choline levels, oxidative stress, and neuroinflammation are the primary mechanisms implicated in AD progression. Simultaneous inhibition of acetylcholinesterase (AChE) and reactive oxygen species (ROS) production by a single molecule may provide a new breath of hope for AD treatment. Here, we describe donepezil-tacrine hybrids as inhibitors of AChE and ROS. Four series of derivatives with a β-amino alcohol linker were designed and synthesized. In this study, the target compounds were evaluated for their ability to inhibit AChE and butyrylcholinesterase (BuChE) in vitro, using tacrine (hAChE, IC50 = 305.78 nM; hBuChE, IC50 = 56.72 nM) and donepezil (hAChE, IC50 = 89.32 nM; hBuChE, IC50 = 9137.16 nM) as positive controls. Compound B19 exhibited an excellent and balanced inhibitory potency against AChE (IC50 = 30.68 nM) and BuChE (IC50 = 124.57 nM). The cytotoxicity assays demonstrated that the PC12 cell viability rates of compound B19 (84.37 %) were close to that of tacrine (87.73 %) and donepezil (79.71 %). Potential therapeutic effects in AD were evaluated using the neuroprotective effect of compounds against H2O2-induced toxicity, and compound B19 (68.77 %) exhibited substantially neuroprotective activity at the concentration of 25 μM, compared with the model group (30.34 %). Furthermore, compound B19 protected PC12 cells from H2O2-induced apoptosis and ROS production. These properties of compound B19 suggested that it was a multi-functional agent with AChE inhibition, anti-oxidative, anti-inflammatory activities, and low toxicity and that it deserves further investigation as a promising agent for AD treatment.

Intestinal Atp8b1 dysfunction causes hepatic choline deficiency and steatohepatitis

Choline is an essential nutrient, and its deficiency causes steatohepatitis. Dietary phosphatidylcholine (PC) is digested into lysoPC (LPC), glycerophosphocholine, and choline in the intestinal lumen and is the primary source of systemic choline. However, the major PC metabolites absorbed in the intestinal tract remain unidentified. ATP8B1 is a P4-ATPase phospholipid flippase expressed in the apical membrane of the epithelium. Here, we use intestinal epithelial cell (IEC)-specific Atp8b1-knockout (Atp8b1IEC-KO) mice. These mice progress to steatohepatitis by 4 weeks. Metabolomic analysis and cell-based assays show that loss of Atp8b1 in IEC causes LPC malabsorption and thereby hepatic choline deficiency. Feeding choline-supplemented diets to lactating mice achieves complete recovery from steatohepatitis in Atp8b1IEC-KO mice. Analysis of samples from pediatric patients with ATP8B1 deficiency suggests its translational potential. This study indicates that Atp8b1 regulates hepatic choline levels through intestinal LPC absorption, encouraging the evaluation of choline supplementation therapy for steatohepatitis caused by ATP8B1 dysfunction.

Enhanced trimethylamine metabolism and gut dysbiosis in type 2 diabetes mellitus with microalbumin.

Abnormal gut microbiota and blood trimethylamine-N-oxide (TMAO) metabolome have been reported in patients with type 2 diabetes mellitus (T2DM) and advanced diabetic nephropathy. This study aimed to investigate the gut microbiota profiles and a group of targeted urine metabolic characteristics in T2DM patients with or without microalbuminuria, to determine the correlation between the gut microbiota composition, trimethylamine (TMA) metabolism, and the clinical features during progression of diabetic kidney disease (DKD). This study included 26 T2DM patients with microalbuminuria (Micro), 26 T2DM patients with normoalbuminuria (Normo), and 15 healthy controls (HC). Urine and Fecal samples were detected using ultra performance liquid chromatography tandem mass spectrometry and 16S ribosomal DNA gene sequencing, respectively. The TMAO/TMA ratio decreased gradually during the HC-Normo-Micro transition. The levels of TMA, choline and betaine were significantly different between the HC group and the T2DM patients belonging to both Normo and Micro groups. At the operational taxonomic unit (OTU) level, the gut microflora diversity was significantly reduced in the Micro groups compared to the HC groups and the Normo groups. Taxonomic analyses revealed significant consumption in the relative abundances of eight bacterial genera and significant enrichment of two bacterial genera during the HC-Normo-Micro transition. Furthermore, the relative abundances of six bacterial genera, namely, Ruminococcus_1, [Eubacterium]_ruminantium_group, Roseburia, Faecalibacterium, Fusicatenibacter and Coprococcus_3 exhibited significant differences, and were associated with elevated urinary albumin creatinine ratio (UACR), TMAO/TMA, TMA and its precursors in the Micro group compared with the other groups. The imbalance of gut microbiota has occurred in patients with early-stage DKD, and the consumption of short-chain fatty acid-producing bacteria were associated with the accumulation of TMA and UACR.