Hepatic Vitamin Research Articles

Vitamin K2 Supplementation in Hospitalised COVID-19 Patients: A Randomised Controlled Trial.

Background: In observational studies, high levels of desphospho-uncarboxylated matrix gla protein (dp-ucMGP) that result from vitamin K deficiency were consistently associated with poor clinical outcomes during COVID-19. Vitamin K-activated matrix gla protein (MGP) is required to protect against elastic fibre degradation, and a deficiency may contribute to pathology. However, intervention trials assessing the effects of vitamin K supplementation in COVID-19 are lacking. Methods: This is a single-centre, phase 2, double-blind, randomised, placebo-controlled trial investigating the effects of vitamin K2 supplementation in 40 hospitalised COVID-19 patients requiring supplemental oxygen. Individuals were randomly assigned in a 1:1 ratio to receive 999 mcg of vitamin K2-menaquinone-7 (MK-7)-or a placebo daily until discharge or for a maximum of 14 days. Dp-ucMGP, the rate of elastic fibre degradation quantified by desmosine, and hepatic vitamin K status quantified by PIVKA-II were measured. Grade 3 and 4 adverse events were collected daily. As an exploratory objective, circulating vitamin K2 levels were measured. Results: Vitamin K2 was well tolerated and did not increase the number of adverse events. A linear mixed model analysis showed that dp-ucMGP and PIVKA-II decreased significantly in subjects that received supplementation compared to the controls (p = 0.008 and p = 0.0017, respectively), reflecting improved vitamin K status. The decrease in dp-ucMGP correlated with higher plasma MK-7 levels (p = 0.015). No significant effect on desmosine was found (p = 0.545). Conclusions: These results demonstrate that vitamin K2 supplementation during COVID-19 is safe and decreases dp-ucMGP. However, the current dose of vitamin K2 failed to show a protective effect against elastic fibre degradation.

Modest effect of differential dietary vitamin A intake on the pathogenesis of alcohol-associated liver disease.

Chronic alcohol consumption is a major public health issue. The primary organ damaged by alcohol abuse is the liver, leading to alcohol-associated liver disease (ALD). ALD begins with hepatic steatosis and can progress to fibrosis and cirrhosis; however, we have an incomplete understanding of ALD pathogenesis. Interestingly, the liver is also the major organ for vitamin A metabolism and storage, and ALD has previously been linked with altered hepatic vitamin A homeostasis. We hypothesize that alcohol-induced vitamin A depletion disrupts its normal function in the liver, contributing to the pathogenesis of ALD. To test this hypothesis, we postulated that adding copious vitamin A to the diet might alleviate ALD, and conversely, that a vitamin A deficient diet would worsen ALD. We conducted two dietary intervention studies in mice comparing deficient (0 IU/g diet) and copious (25 IU/g diet) dietary vitamin A intake versus control (4 IU/g diet), using the NIAAA chronic-binge model of ALD. Hepatic steatosis was assessed using histopathological and biochemical approaches. Tissue Vitamin A levels were measured using high-performance liquid chromatography. Markers of ALD, hepatic inflammation and lipid metabolism were analyzed by the quantitative polymerase chain reaction and western blotting. As expected, a 0 IU/g Vitamin A diet decreased, and a 25 IU/g Vitamin A diet increased hepatic Vitamin A stores. However, alcohol induced changes in hepatic triglyceride levels, markers of hepatic lipid metabolism, inflammation and fibrosis were not significantly different in mice consuming a copious or deficient vitamin A diet compared to control. Altered vitamin A intake and hepatic vitamin A storage have a minor effect on the pathogenesis of ALD. Thus, given the known link between altered retinoic acid signaling and ALD, future studies that further explore this linkage are warranted.

Correlation Between Serum Vitamin E and HOMA-IR in Patients with T2DM.

Peroxidation is one of the important causes of insulin resistance (IR), and vitamin E is a natural antioxidant, and there may be some correlation between serum vitamin E levels and insulin resistance. The correlation between serum vitamin E and insulin resistance in type 2 diabetes mellitus (T2DM) population. Two hundred and forty-two people (119 with T2DM) were included. One hundred and nineteen patients with T2DM were selected as the case group, and 123 people with non-T2DM were selected as the control group. People insulin resistance was detected by the homeostasis model assessment method (HOMA-IR) greater than 2.69 were included in the diabetic insulin resistance group, and those with HOMA-IR less than 2.69 were included in the diabetic non-insulin resistance group. Record the general body indicators, biochemical indicators, hepatic function indicators, vitamin E, and other indicators. Correlation analysis, logistic regression, trend analysis, and restricted cubic spline (RCS) were performed using SPSS 25.0 and R 4.1.1 software. Correlation analysis, logistic regression, trend analysis, restricted cubic spline (RCS) analysis were conducted on general body indicators, biochemical indicators, hepatic function indicators, vitamin E, and other indicators. The logistic regression results showed that after adjusting for confounding factors, vitamin E was an independent influencing factor for insulin resistance in T2DM patients (P < 0.001). The trend analysis results show that with the decrease of serum vitamin E levels, the risk of insulin resistance in T2DM patients gradually increases. The RCS results showed that the risk of insulin resistance was significantly increased when the serum vitamin E level was lower than 10,575.23 ng/mL. Serum vitamin E levels are lower in T2DM patients than in healthy populations; Vitamin E is an independent influencing factor for HOMA-IR in T2DM patients. The risk of insulin resistance gradually increases in T2DM patients as serum vitamin E levels decrease. Vitamin E is a risk factor for insulin resistance at serum vitamin E levels below 10,575.23 ng/mL. At higher serum vitamin E levels than 10,575.23 ng/mL, vitamin E is a protective factor for insulin resistance.

LX-2 Stellate Cells Are a Model System for Investigating the Regulation of Hepatic Vitamin A Metabolism and Respond to Tumor Necrosis Factor α and Interleukin 1β.

Hepatic stellate cells (HSCs) are the major site of vitamin A (retinol) esterification and subsequent storage as retinyl esters within lipid droplets. However, retinyl esters become depleted in many pathophysiological states, including acute and chronic liver injuries. Recently, using a liver slice culture system as a model of acute liver injury and fibrogenesis, a time-dependent increase and decrease in the apparent formation of the bioactive retinoid all-trans-retinoic acid (atRA) and retinyl palmitate was measured, respectively. This coincided with temporal changes in the gene expression of retinoid-metabolizing enzymes and binding proteins, that preceded HSC activation. However, the underlying mechanisms that promote early changes in retinoid metabolism remain unresolved. We hypothesized that LX-2 cells could be applied to investigate differences in quiescent and activated HSC retinoid metabolism. We demonstrate that the hypermetabolic state of activated stellate cells relative to quiescent stellate cells may be attributed to induction of STRA6, RBP4, and CYP26A1, thereby reducing intracellular concentrations of atRA. We further hypothesized that paracrine and autocrine cytokine signaling regulates HSC vitamin A metabolism in both quiescent and activated cells. In quiescent cells, tumor necrosis factor α dose-dependently downregulated LRAT and CRBP1 mRNA, with EC50 values of 30-50 pg/mL. Likewise, interleukin-1β decreased LRAT and CRBP1 gene expression but with less potency. In activated stellate cells, multiple enzymes were downregulated, suggesting that the full effects of altered hepatic vitamin A metabolism in chronic conditions require both paracrine and autocrine signaling events. Further, this study suggests the potential for cell type-specific autocrine effects in hepatic retinoid signaling. SIGNIFICANCE STATEMENT: HSCs are the major site of vitamin A storage and important determinants of retinol metabolism during liver fibrogenesis. Here, two LX-2 culture methods were applied as models of hepatic retinoid metabolism to demonstrate the effects of activation status and dose-dependent cytokine exposure on the expression of genes involved in retinoid metabolism. This study suggests that compared to quiescent cells, activated HSCs are hypermetabolic and have reduced apparent formation of retinoic acid, which may alter downstream retinoic acid signaling.

Cytochrome P450 Family 4F2 and 4F11 Haplotype Mapping and Association with Hepatic Gene Expression and Vitamin K Hydroxylation Activity.

This study evaluated the underlying mechanistic links between genetic variability in vitamin K metabolic pathway genes (CYP4F2 and CYP4F11) and phylloquinone hydroxylation activity using genotype- and haplotype-based approaches. Specifically, we characterized genetic variability in the CYP4F2/CYP4F11 locus and compared common single allele genotypes and common haplotypes as predictors of hepatic gene expression, enzyme abundance, and phylloquinone (VK1) ω-hydroxylation kinetics. We measured CYP4F2 and CYP4F11 mRNA levels, CYP4F2 and CYP4F11 protein abundances, and the VK1 concentration-dependent ω-hydroxylation rate in matched human liver nucleic acid and microsome samples, utilizing a novel in vitro population modeling approach. Results indicate that accounting for the CYP4F2*3 allele alone is sufficient to capture most of the genetic-derived variability in the observed phenotypes. Additionally, our findings highlight the important contribution that CYP4F11 makes toward vitamin K metabolism in the human liver.

Exposure to artificial ultraviolet-B light mediates alterations on the hepatic transcriptome and vitamin D metabolism in pigs

In the currently prevailing pig husbandry systems, the vitamin D status is almost exclusively dependent on dietary supply. Additional endogenous vitamin D production after exposure to ultraviolet-B (UVB) light might allow the animals to utilize minerals in a more efficient manner, as well as enable the production of functional vitamin D-enriched meat for human consumption. In this study, growing pigs (n = 16) were subjected to a control group or to a daily narrowband UVB exposure of 1 standard erythema dose (SED) for a period of 9 weeks until slaughter at a body weight of 105 kg. Transcriptomic profiling of liver with emphasis on the associated effects on vitamin D metabolism due to UVB exposure were evaluated via RNA sequencing. Serum was analyzed for vitamin D status and health parameters such as minerals and biochemical markers. The serum concentration of calcidiol, but not calcitriol, was significantly elevated in response to UVB exposure after 17 days on trial. No effects of UVB exposure were observed on growth performance and blood test results. At slaughter, the RNA sequencing analyses following daily UVB exposure revealed 703 differentially expressed genes (DEGs) in liver tissue (adjusted p-value < 0.01). Results showed that molecular pathways for vitamin D synthesis (CYP2R1) rather than cholesterol synthesis (DHCR7) were preferentially initiated in liver. Gene enrichment (p < 0.05) was observed for reduced cholesterol/steroid biosynthesis, SNARE interactions in vesicular transport, and CDC42 signaling. Taken together, dietary vitamin D supply can be complemented via endogenous production after UVB exposure in pig husbandry, which could be considered in the development of functional foods.

Hepatic Vitamin A Concentrations and Association with Infectious Causes of Child Death

To assess postmortem vitamin A (VA) concentrations in children under 5years of age and evaluate the association between VA deficiency (VAD) and infectious causes of death (CoD). In this cross-sectional study from the Child Health and Mortality Prevention Surveillance (CHAMPS) Network, liver biopsies collected within 72hours of death were analyzed from 405 stillbirths and children under 5years in Kenya and South Africa. Total liver VA (TLVA) concentrations were quantified using ultra-performance liquid chromatography, and cutoffs of ≤0.1μmol/g, >0.1 to <0.7μmol/g, ≥0.7 to <1.0μmol/g, and ≥1.0μmol/g were used to define VAD, adequate VA status, high VA, and hypervitaminosis A, respectively. CoD were determined by expert panel review. Among 366 liver samples with viable extraction, pooled prevalences of VAD, adequacy, high VA, and hypervitaminosis were 34.2%, 51.1%, 6.0%, and 8.7%, respectively. VAD was more common among neonates compared with stillbirths, infants, or children, and among those with low birthweight (LBW), underweight, or stunting (P<.05). When adjusting for site, age, and sex, there was no significant association of VAD with increased infectious CoD (OR 1.9, 95% confidence interval [CI] 0.9, 3.8, P=.073). In stratified analyses, VA deficient boys, but not girls, had an increased risk of infectious CoD (OR 3.4, 95% CI 1.3, 10.3, P=.013). Definitive postmortem assessment of VA status identified both VAD and VA excess among children under 5years of age in Kenya and South Africa. VAD in boys was associated with increased risk of infectious mortality. Our findings may inform a transition from universal VA supplementation (VAS) to targeted strategies in certain countries.

Postmortem diagnoses and factors influencing diagnoses in captive white-tailed deer in Wisconsin, 2009-2021.

There have been significant changes to Wisconsin agriculture since ~2010, one of which is the growth of commercial farming of white-tailed deer (WTD; Odocoileus virginianus). These high-density populations may lead to the emergence of previously unrecognized or under-recognized disease trends. I evaluated archived pathology records at the Wisconsin Veterinary Diagnostic Laboratory (WVDL) from 2009-2021 for captive WTD postmortem cases and included records from 277 WTD cases. Diagnoses were found in 81.9% of cases, with an average of 1.3 diagnoses per animal. Submissions with a clinical history of respiratory disease were 7.0 times more likely to have a diagnosis than the average case. Fawns were 1.9 times more likely to have a diagnosis. The most common diagnoses were bronchopneumonia and enteritis and/or enterocolitis (both 16.2% of total diagnoses). The most common isolates from bronchopneumonia cases were Pasteurella multocida, Bibersteinia trehalosi, and Trueperella pyogenes. The pathogens identified most often in enteritis and/or enterocolitis cases were rotavirus, Clostridium perfringens, and Escherichia coli. The most common non-infectious diagnoses were poor nutritional status or inanition, hepatic lipidosis, and selenium and/or vitamin E deficiency. Focusing on testing for pathogens in fawns and in cervid respiratory disease complex submissions may be recommended for laboratories expanding their WTD testing.

Can Dietary Hazelnut Oil Inclusion Alleviate the Negative Effects of Oxidized Fish Oil in Rainbow Trout (Oncorhynchus mykiss) Juveniles?

Rainbow trout juveniles were fed different levels of fresh fish oil, oxidized fish oil and fresh hazelnut oil for 9 weeks. Growth performance and feed efficiency was significantly influenced by oxidized fish oil (P&lt;0.05), but not by hazelnut oil supplementation and their interaction. Fish fed diets containing fresh fish oil had better growth and feed efficiency than those fed diets containing oxidized fish oil. Digestibility decreased with the increase in both dietary oxidized fish oil and hazelnut oil. Fatty acid profile in whole body lipids was significantly influenced by the experimental diets (P&lt;0.05). Polyunsaturated fatty acids (PUFA) showed significant decrease with both dietary hazelnut oil inclusion and dietary oxidized fish oil. Dietary hazelnut oil resulted in a significant increase in hepatic vitamin E and a significant decrease in lipid peroxidation level (P&lt;0.05). Our overall results suggested that dietary oxidized lipids caused growth depletion, lowered nutrient digestibility, lipid peroxidation, and decreased eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic (DHA; 22:6n-3) levels in rainbow trout. However, dietary hazelnut oil inclusion alleviated the negative effects of oxidized oil, sparing n-3 long-chain PUFAs such as EPA and DHA, and increasing hepatic α-tocopherol level which lowered lipid peroxidation despite no significant impact on growth.

A Case Report of Low-Dose Steroid Induced Psychosis in an Older Adult with Rheumatoid Arthritis

IntroductionRheumatoid arthritis (RA) is typically known for its intra-articular manifestations in the joints, and steroids are considered one of the first-line medications for it. Steroids are known for neuropsychiatric manifestations, but it is rarely reported in low-dose steroids.Objectives We describe a case of psychosis in an older adult with RA precipitated by low-dose prednisone with no past history of neuropsychiatric symptoms from steroids in the past five years.MethodsMiss X is a 63-year-old female with past history of RA, major depressive disorder, hypothyroidism, chronic obstructive pulmonary disease, and hypertension, presented with one-week history of irritable mood, increased psychomotor agitation, decreased need for sleep and appetite, and delusions of grandeur and persecution. Her depression had been treated with oral duloxetine 60mg twice daily, oral buspirone 10mg at night, and oral trazodone 150mg at night. She did have a urinary tract infection a week prior, but the psychotic symptoms persisted with antibiotic treatment. Miss X had also been on a monthly taper regimen of low-dose oral prednisone for RA (from 15mg to 5mg) for the past three months and had completed the regimen one week ago. On mental status examination, she was alert and oriented to time, place, and person. Her mood was irritable with lability. She demonstrated tangential speech along with persecutory and grandiose delusions. Attention and concentration was normal with intact immediate and remote memory and impaired recent memory. Abstract ability, judgment, and insight were impaired. Physical examination and vital signs were within normal limits. Laboratory investigations of complete blood count, urine analysis, urine drug screen, thyroid function panel, renal function panel, hepatic function panel, serum sodium, potassium, calcium, thiamine, vitamin B12, folate, and vitamin D did not show any significant abnormalities.ResultsMiss X was admitted to the inpatient psychiatric unit with the diagnosis of medication-induced psychotic disorder, with onset after medication use as per The Diagnostic and Statistical Manual of Mental Disorders 5th edition- Text Revision. Oral olanzapine 10mg at night and oral lithium 300mg twice daily was started along with her home medications of oral duloxetine 60 mg twice daily and oral trazodone 150mg at night. During hospital stay, oral olanzapine was gradually increased to 15mg in the night but had to be reduced back to 10mg in the night due to sedation. Miss X’s symptoms improved during hospital stay and she was discharged on the 13th day of hospitalization with the same psychotropic medication regimen.ConclusionsOur case demonstrates the need for caution in prescribing steroids in older adults as it can precipitate neuropsychiatric symptoms even with a change in use or after withdrawal of steroids.Disclosure of InterestNone Declared

Delayed Structure – function alterations in Pancreas and Liver of Rodent Diabetic Model treated with Salacia oblonga.

Salacia oblonga (S. oblonga) is a component of several antidiabetic medications in alternative and folklore medicine. An evaluation of the hydroalcoholic root extract of S.oblonga (SOE) on the hepatocellular and pancreatic environment in the diabetic (Streptozotocin) rodent model was designed. SOE was fed in two doses for a period of 16 weeks. Regeneration of endocrine pancreas, significant increase in hepatic and pancreatic Vitamin C, reduced Glutathione (GSH), Protein thiols (PT) and decrease in Malondialdehyde (MDA measured as TBARS) and Carbonyl proteins (CP) were observed on treatment with SOE. Conversely, there was also an increase in alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT). Corroborating the above findings, histopathological examination of the liver and pancreatic tissue showed disrupted architecture in treated rats. It may be suggested that SOE has a sustained hepatic antioxidant effect and improved β-cell structure and function in diabetic rats, but the higher dose was mildly toxic to hepatocytes necessitating an exercise of caution in using SOE for therapy for prolonged periods.

Evaluation of saturated and unsaturated fat with vitamin A or beta-carotene supplementation in nursery pigs.

One hundred and fifty-two nursery pigs (PIC, Hendersonville, TN) were randomly assigned to mix sex pens and one of six dietary treatments in a 3 × 2 factorial. Diets included no added fat, 3% added choice white grease, or 3% added soy oil with either a supplemented vitamin A (for a total of 11,640 IU vitamin A/kg, Rovimix A 1000, DSM, Parsippany, NJ, US) or beta-carotene (for a total of 8,708 IU vitamin A/kg equivalent, Rovimix β-Carotene 10%, DSM). Pigs were given a 3-d adaptation period upon arrival. Pigs were weighed at the start of the study and at the end of each phase. A blood sample was taken from one pig per pen at the start and end of the study. Tissues were collected from eight pigs at the start of the study and six pigs per treatment at the end of the study. Data were analyzed via the GLIMMIX procedure in SAS 9.4 (SAS Inst., Cary, NC). Pen was the experimental unit, and repeated measures were used for growth performance and blood parameters. There was no fat by supplement interaction (P > 0.05) on body weight (BW), but there was a tendency (P = 0.054) for heavier BWs when soy oil was added to diets. There was no difference (P > 0.05) in average daily feed intake or average daily gain (ADG). There was an improved gain:feed (P = 0.02) when pigs were fed choice white grease over no added fat. There were time differences (P < 0.05) for plasma vitamins A (retinol), D (25 hydroxy vitamin D3), and E (alpha-tocopherol). Vitamin A and D values were higher at the end of the study, whereas vitamin E values were lower at the end of the study. The choice white grease diets had the highest (P < 0.05) plasma vitamins D and E (6.74 ng/mL and 2.87 ppm, respectively). Pigs supplemented with vitamin A had higher (P < 0.05) hepatic vitamin A than pigs supplemented with beta-carotene (19.9 vs. 15.6 ppm, respectively). There were no differences (P < 0.05) between immunoglobulins G and M or mRNA abundance of select genes (retinol binding protein 2, alcohol dehydrogenase class 1, lecithin retinol acyltransferase phosphatidylcholine-retinol O-acyltransferase, and beta-carotene oxygenase 1). In conclusion, fat inclusion level and type, with either vitamin A or beta-carotene supplementation, did not affect the overall nursery pig growth performance. The addition of fat resulted in an increase in ADG and BW. Diets with choice white grease had the highest plasma vitamins D and E, and supplemental vitamin A increased hepatic vitamin A.

Uncovering the physiological impacts of soybean meal replacement by Narbonne vetch (Vicia narbonensis) meal in rainbow trout (Oncorhynchus mykiss) diets: Towards the future and sustainable European aquaculture.

The identification and implementation of raw materials to replace fish meal (FM) or its major alternative, soybean meal (SBM), among other factors, is crucial for the sustainable growth of aquaculture. Narbonne vetch (Vicia narbonensis) meal (NVM) has previously been identified as a promising alternative raw material locally produced in Europe to replace SBM. Previous work has showed that 33% replacement of SBM by NVM treated with a commercially available phytase (Rovabio® PHY) does not compromise fish growth performance in a 63-day trial. Here, a deeper characterization of the potential use of NVM to replace SBM was performed to unveil any potential undesired physiological impact in rainbow trout (Oncorhynchus mykiss) juveniles with an initial weight of 38.04 ± 0.07 g. After a 63-day feeding trial, high (66%) SBM replacement by NVM (even when treated with Rovabio® PHY) had a negative impact on rainbow trout: decreasing the activity of alkaline proteases, trypsin, chymotrypsin, and α-amylase; inducing cell shrinkage in hepatocytes; and reducing plasma triglycerides and hepatic vitamin E (VE) levels. No biochemical alterations were observed in blood plasma glucose, cholesterol or redox enzymes, regardless of the % of SBM replacement and/or Rovabio® PHY treatment. In fish fed diets with 33% replacement of SBM by NVM (regardless of being treated with Rovabio® PHY or not), only a reduced content of plasma triglycerides, and a slight modification in the position of the nucleus in enterocytes (more intermediate) from the proximal intestine, were reported. Altered metabolism of both carbohydrates and VE was also confirmed at transcriptional level, possibly being related to the presence of non-starch polysaccharides (NSPs) in NVM. The present study identifies future strategies to improve the use of NVM as an alternative raw material to replace SBM, allowing greater sustainability, and a lower carbon footprint in European aquafeeds to be achieved.

Hepatic vitamin D receptor expression is negatively associated with liver inflammation and fibrosis in patients with chronic HBV infection.

The vitamin D receptor (VDR) is a nuclear transcription factor that acts as the main transducer in response to vitamin D (VD), regulating about 3% of thegene expression inthehumangenome. This study investigated the expression of VDR in the liver of patients with chronic hepatitis B virus (HBV) infection and determined its correlation with liver inflammation and fibrosis. We evaluated the effects of HBV infection on the expression of VDR in vivo and in vitro and further investigate the potential mechanism. Subsequently, the associations between hepatic VDR expression with liver inflammation and fibrosis were statistically analyzed. Results showed that hepatic VDR expression was significantly decreased in patients with chronic HBV infection as compared to healthy individuals. Similarly, in vitro experiments further confirmed that HBV infection could inhibit the expression of VDR in hepatocytes. Mechanistically, HBV was able to directly induce the expression of miR-125a which inhibited the mRNA and protein levels of VDR. Statistical analysis showed that hepatic VDR expression was significantly negatively correlated with liver inflammation and fibrosis in patients. We conclude that inhibition of hepatic vitamin D receptor expression by HBV/miR-125a is negatively associated with liver inflammation and fibrosis in patients with chronic HBV infection.

Baat Gene Knockout Alters Post-Natal Development, the Gut Microbiome, and Reveals Unusual Bile Acids in Mice

Bile acids (BAs) are steroid detergents in bile that contribute to fat absorption, cell signaling, and microbiome interactions. The final step in their synthesis is amino acid conjugation with either glycine or taurine in the liver by the enzyme bile acid-CoA:amino acid N-acyltransferase (BAAT). Here, we describe the microbial, chemical, and physiological consequences of Baat gene knockout. Baat-/- mice were underweight after weaning but quickly exhibited catch-up growth. At three weeks of age, KO animals had increased phospholipid excretion and decreased subcutaneous fat pad mass, liver mass, glycogen staining in hepatocytes, and hepatic vitamin A stores, but these were less marked in adulthood. Additionally, KO mice had an altered microbiome in early life. Their BA pool was highly enriched in cholic acid but not completely devoid of conjugated BAs. KO animals had 27-fold lower taurine-conjugated BAs than wild type in their liver but similar concentrations of glycine-conjugated BAs and higher microbially conjugated BAs. Furthermore, the BA pool in Baat-/- was enriched in a variety of unusual BAs that were putatively sourced from cysteamine conjugation with subsequent oxidation and methylation of the sulfur group mimicking taurine. Antibiotic treatment of KO mice indicated the microbiome was not the likely source of the unusual conjugations, instead, the unique BAs in KO animals were likely derived from the peroxisomal acyltransferases Acnat1 and Acnat2, which are duplications of Baat in the mouse genome that are inactivated in humans. This study demonstrates that BA conjugation is important for early life development of mice.

Acute retinol mobilization by retinol-binding protein 4 in mouse liver induces fibroblast growth factor 21 expression

Hepatocytes secrete retinol-binding protein 4 (RBP4) into circulation, thereby mobilizing vitamin A from the liver to provide retinol for extrahepatic tissues. Obesity and insulin resistance are associated with elevated RBP4 levels in the blood. However, in a previous study, we observed that chronically increased RBP4 by forced Rbp4 expression in the liver does not impair glucose homeostasis in mice. Here, we investigated the effects of an acute mobilization of hepatic vitamin A stores by hepatic overexpression of RBP4 in mice. We show that hepatic retinol mobilization decreases body fat content and enhances fat turnover. Mechanistically, we found that acute retinol mobilization increases hepatic expression and serum levels of fibroblast growth factor 21 (FGF21), which is regulated by retinol mobilization and retinoic acid in primary hepatocytes. Moreover, we provide evidence that the insulin-sensitizing effect of FGF21 is associated with organ-specific adaptations in retinoid homeostasis. Taken together, our findings identify a novel crosstalk between retinoid homeostasis and FGF21 in mice with acute RBP4-mediated retinol mobilization from the liver.

50 Years Ago in TheJournalofPediatrics: Rickets and Antiepileptic Drugs: What Have We Learned?

Borgstedt AD, Bryson MF, Young LW, Forbes GB. Long-term administration of antiepileptic drugs and the development of rickets. J Pediatr 1972;81:9-15. In 1972, Borgstedt et al reported 2 neurologically impaired children who developed rickets after years of antiepileptic drug therapy. The diagnosis was based on physical findings, radiographs, and serum calcium, phosphate, and alkaline phosphatase levels. Rickets resolved with daily doses of calcium and large amounts of vitamin D, despite continuance of the antiepileptic drugs. Missing were measures of vitamin D metabolites, presumably owing to a lack of available clinical assays at that time. Our knowledge of vitamin D metabolism has progressed far beyond the already established metabolic pathways of hepatic 25-hydroxylation and renal 1-hydroxylation of that era. As the authors suspected, antiepileptic drugs, and other drugs, cause rickets by increased hepatic vitamin D catabolism. Induction of catabolic enzymes leaves less vitamin D for eventual renal conversion to the active metabolite 1,25 dihydroxyvitamin D (1,25-D). With inadequate 1,25-D, calcium absorption is impaired, contributing to inadequate bone mineralization. As extracellular calcium decreases, parathyroid hormone responds, but this response causes phosphaturia, further under mineralizing bone. In vitamin D disorders, bone chondrocyte function is also altered, leading to metaphyseal abnormalities explaining many hallmark features of vitamin D rickets, such as widened wrists and rachitic rosary. Other bone health issues in children with epileptic disorders, not related to vitamin D deficiency, include seizure-associated trauma, nonambulatory status, and nutritional deficiencies. The measurement of the main circulating metabolite, 25-hydroxyvitamin D (25-D), is widely available. Problems remain, including assay variability and an inconsistent relationship of level to clinical impact; for example, a 25-D level of 12 ng/mL may cause rickets in 1 individual and no notable signs in another. The 25-D levels are, at best, a surrogate for potential 1,25-D production. Another issue is that 25-D is measured in nanograms per milliliter, with acceptable levels in children generally considered to be more than 20 ng/mL. However, 1,25-D is measured in picograms per milliliter, or a 1000-fold less concentration. Why is a 25-D level of 10 000 pg/mL (=10 ng/mL) not enough substrate to provide adequate 1,25-D production to the 20-80 pg/mL reference range? From their inference of vitamin D deficiency, Borgstedt et al helped to identify an important preventable complication of antiepileptic drug use in children. Incorporating these findings into clinical guidelines remains to be completed.

Beta-Cryptoxanthin Supplementation Protects Against Liver Cancer Progression and Correlates With Altered Targeted and Untargeted Metabolomic Profiles in Mice

ObjectivesNonalcoholic fatty liver disease (NAFLD)-associated hepatocellular carcinoma (HCC) is expected to increase globally in the upcoming years. Diets high in refined carbohydrates and added sugars (HRCD) have been linked to NAFLD progression. Previous studies have demonstrated that retinoids possess anti-tumorigenic properties, yet less is known about whether upstream provitamin A carotenoids exhibit similar characteristics. We recently demonstrated that dietary beta-cryptoxanthin (BCX), a provitamin A carotenoid, decreased NAFLD severity and HCC progression in diethylnitrosamine (DEN)-initiated, high refined carbohydrate diet (HRCD)-fed mice. In this study, we evaluated the effects of dietary BCX supplementation on modulating plasma biomarkers, hepatic vitamin A status, and plasma metabolomic profiles in our DEN-initiated, HRCD-promoted model of HCC. MethodsMale, six-week-old C57BL/6J mice were injected with DEN (25 mg/kg BW) and a fed a HRCD (66.5% carbs including sucrose) with or without BCX supplementation (10 mg/kg diet) for 24 weeks. Using plasma samples, we performed metabolomics using our UHPLC-QTOF-MS platform, a targeted Biocrates MxP Quant 500 kit, and a complimentary untargeted analysis of phospholipids from the METLIN database to identify metabolites which correlate with primary outcomes. Hepatic vitamin A levels were determined via HPLC. ResultsCompared to HRCD-fed, DEN-injected mice, mice fed BCX displayed significantly lower tumor burden and steatosis, higher hepatic vitamin A status, and lower plasma levels of alanine transaminase (ALT) and lactate dehydrogenase (LDH). Moderate negative correlations were also identified amongst hepatic vitamin A levels and primary outcomes, such as HCC tumor number, steatosis score, and relevant biomarkers. Our metabolomics data showed significant modulations in metabolites with BCX treatment from phosphatidylcholine, sphingomyelin, ceramide, bile acid, and other phospholipid classes. ConclusionsBCX supplementation significantly reduced HCC severity, increased hepatic vitamin A status, reduced plasma levels of ALT and LDH, and altered several lipid-related classes of metabolites, thus supporting a chemopreventive potential for BCX against HRCD-promoted HCC development. Funding SourcesUSDA/ARS and NIFA/AFRI.

Metformin-induced vitamin B12 deficiency can cause or worsen distal symmetrical, autonomic and cardiac neuropathy in the patient with diabetes.

Metformin blocks the absorption of vitamin B12 through a mechanism that has not been established but could be because of interference with the calcium-dependent binding of the intrinsic factor vitamin B12 complex to the cubam receptor in the terminal ileum. The subsequent deficiency of vitamin B12 may cause or accelerate distal symmetrical and autonomic neuropathy in the patient with diabetes. Several observational studies and meta-analyses have reported a significant association between metformin utilization and vitamin B12 deficiency. Prospective studies have shown that not only do metformin utilizers have lower vitamin B12 levels but they also have higher frequencies of distal symmetrical polyneuropathy and autonomic neuropathy (including cardiac denervation, which is associated with increased incidences of cardiac arrhythmias, cardiac events and mortality). Therefore, periodic monitoring of vitamin B12 is recommended in all patients who utilize metformin, particularly if metformin has been used for over 5 years at which stage hepatic stores of vitamin B12 would probably be depleted. Factors that accelerate the loss of hepatic vitamin B12 stores are proton pump inhibitors, bariatric surgery, being elderly and having an increased turnover of red blood cells. If serum vitamin B12 levels are borderline, measurement of methylmalonic acid and homocysteine levels can detect vitamin B12 deficiency at its earliest stage. Therapies include prophylactic calcium and vitamin B12 supplements, metformin withdrawal, replenishing vitamin B12 stores with intramuscular or oral vitamin B12 therapy and regular monitoring of vitamin B12 levels and vitamin B12 supplements if metformin continues to be utilized. With adequate vitamin B12 replacement, while symptoms of neuropathy may or may not improve, objective findings of neuropathy stabilize but do not improve.

Streptozotocin-induced Diabetes Represses Hepatic CYP2R1 Expression but Induces Vitamin D 25-Hydroxylation in Male Mice.

Vitamin D deficiency [ie, low plasma 25-hydroxyvitamin D (25-OH-D)] associates with the prevalence of metabolic diseases including type 1 diabetes; however, the molecular mechanisms are incompletely understood. Recent studies have indicated that both fasting and metabolic diseases suppress the cytochrome P450 (CYP) 2R1, the major hepatic vitamin D 25-hydroxylase. We specifically studied the effect of a mouse model of type 1 diabetes on the regulation of Cyp2r1 and vitamin D status. We show that streptozotocin-induced diabetes in mice suppresses the expression of the Cyp2r1 in the liver. While insulin therapy normalized the blood glucose levels in the diabetic mice, it did not rescue the diabetes-induced suppression of Cyp2r1. Similar regulation of Cyp2r1 was observed also in the kidney. Plasma 25-OH-D level was not decreased and was, in contrast, higher after 4 and 8 weeks of diabetes. Furthermore, the vitamin D 25-hydroxylase activity was increased in the livers of the diabetic mice, suggesting compensation of the Cyp2r1 repression by other vitamin D 25-hydroxylase enzymes. Cyp27b1, the vitamin D 1α-hydroxylase, expression in the kidney and the plasma 1α,25-dihydroxyvitamin D level were higher after 4 weeks of diabetes, while both were normalized after 13 weeks. In summary, these results indicate that in the mouse model of type 1 diabetes suppression of hepatic Cyp2r1 expression does not result in reduced hepatic vitamin D 25-hydroxylase activity and vitamin D deficiency. This may be due to induction of other vitamin D 25-hydroxylase enzymes in response to diabetes.