Maternal vitamin B12 deficiency in rats alters DNA methylation in metabolically important genes in their offspring.

Vitamin B12 deficiency is a critical problem worldwide and peri-conceptional deficiency of this vitamin is associated with the risk of complex cardio-metabolic diseases. Nutritional perturbations during these stages of development may lead to changes in the fetal epigenome. Using Wistar rat model system, we have earlier shown that low maternal B12 levels are associated with low birth weight, adiposity, insulin resistance, and increased triglyceride levels in the offspring, which might predispose them to the risk of cardio-metabolic diseases in adulthood. In this study, we have investigated the effects of maternal B12 deficiency on genome-wide DNA methylation profile of the offspring and the effect of rehabilitation of mothers with B12 at conception. We have performed methylated DNA immunoprecipitation sequencing of liver from pups in four groups of Wistar rats: Control (C), B12-restricted (B12R), B12-rehabilitated at conception (B12RC), and B12-rehabilitated at parturition (B12RP). We have analyzed differentially methylated signatures between the three groups as compared to controls. We have identified a total of 214 hypermethylated and 142 hypomethylated regions in the 10 kb upstream region of transcription start site in pups of B12-deficient mothers, which are enriched in genes involved in fatty acid metabolism and mitochondrial transport/metabolism. B12 rehabilitation at conception and parturition is responsible for reversal of methylation status of many of these regions to control levels suggesting a causal association with metabolic phenotypes. Thus, maternal B12 restriction alters DNA methylation of genes involved in important metabolic processes and influences the offspring phenotype, which is reversed by B12 rehabilitation of mothers at conception.

Increased stress and altered expression of histone modifying enzymes in brain are associated with aberrant behaviour in vitamin B12 deficient female mice.

A sub-optimal nutritional environment from early life can be envisaged as a stressor that translates into mental health problems in adulthood. After considering (a) the widespread prevalence of vitamin B12 deficiency especially amongst women in developing countries and (b) the importance of vitamin B12 in normal brain function, in this study we have elucidated the behavioural correlates of chronic severe and moderate vitamin B12 deficiency in C57BL/6 mice. Female weanling mice were assigned to three dietary groups: (a) control AIN-76A diet with cellulose as dietary fibre (b) vitamin B12 restricted AIN-76A diet with pectin as dietary fibre (severe deficiency group) and (c) vitamin B12 restricted AIN-76A diet with cellulose as dietary fibre (moderate deficiency group). The mice received these diets throughout pregnancy, lactation and thereafter. Nest-building, maternal care, anxiety and depressive behaviours were evaluated. Oxidative stress, activities of antioxidant enzymes and expression of various histone modifying enzymes in brain were investigated to unravel the probable underlying mechanisms. Our data suggests that both severe and moderate vitamin B12 deficiency induced anxiety and impaired maternal care. However, only severe vitamin B12 deficiency induced depression. Oxidative stress and poor antioxidant defense underlie the deleterious effects of both severe and moderate vitamin B12 deficiency. Altered expression of histone modifying enzymes in the brain of severely deficient mice is suggestive of epigenetic reprogramming. This study suggests that chronic vitamin B12 deficiency leads to behavioural anomalies in female C57BL/6 mice and the severity of these outcomes can be correlated to the level of deficiency.

'Obesageing': Linking obesity & ageing.

Obesity is one of the leading causes of preventable mortalities in many parts of the globe. The rise in geriatric population due to better treatment opportunities has also emerged as a major public health challenge. Both of these health challenges have impacted developed as well as developing countries. Obesity is attributed as a powerful risk factor of a variety of health problems such as cardiovascular diseases, hypertension, type 2 diabetes, dementia, neuropsychiatric diseases and many more. On the other hand, ageing is a natural process involving a gradual decline in physiological functions and is associated with similar co-morbidities as obesity. This review discusses about the commonalities (termed as 'Obesageing') between the pathological phenomenon of obesity and normal physiological process of ageing. A unique rodent model of obesageing has been developed (WNIN/Ob) that has characteristics of morbid obesity as well as premature ageing. Such a novel animal model would facilitate the understanding of the complex interplay of different mechanisms that are common to obesity and ageing and help to devise strategies in future to tackle the growing burden of obesity and ageing.

Epigenomic maintenance through dietary intervention can facilitate DNA repair process to slow down the progress of premature aging.

DNA damage caused by various sources remains one of the most researched topics in the area of aging and neurodegeneration. Increased DNA damage causes premature aging. Aging is plastic and is characterised by the decline in the ability of a cell/organism to maintain genomic stability. Lifespan can be modulated by various interventions like calorie restriction, a balanced diet of macro and micronutrients or supplementation with nutrients/nutrient formulations such as Amalaki rasayana, docosahexaenoic acid, resveratrol, curcumin, etc. Increased levels of DNA damage in the form of double stranded and single stranded breaks are associated with decreased longevity in animal models like WNIN/Ob obese rats. Erroneous DNA repair can result in accumulation of DNA damage products, which in turn result in premature aging disorders such as Hutchinson-Gilford progeria syndrome. Epigenomic studies of the aging process have opened a completely new arena for research and development of drugs and therapeutic agents. We propose here that agents or interventions that can maintain epigenomic stability and facilitate the DNA repair process can slow down the progress of premature aging, if not completely prevent it. © 2016 IUBMB Life, 68(9):717-721, 2016.

Leptin gene promoter DNA methylation in WNIN obese mutant rats.

BACKGROUND: Obesity has become an epidemic in worldwide population. Leptin gene defect could be one of the causes for obesity. Two mutant obese rats WNIN/Ob and WNIN/GROb, isolated at National Centre for Laboratory Animal Sciences (NCLAS), Hyderabad, India, were found to be leptin resistant. The present study aims to understand the regulatory mechanisms underlying the resistance by promoter DNA methylation of leptin gene in these mutant obese rats. METHODS: Male obese mutant homozygous, carrier and heterozygous rats of WNIN/Ob and WNIN/GROb strain of 6 months old were studied to check the leptin gene expression (RT-PCR) and promoter DNA methylation (MassARRAY Compact system, SEQUENOM) of leptin gene by invivo and insilico approach. RESULTS: Homozygous WNIN/Ob and WNIN/GROb showed significantly higher leptin gene expression compared to carrier and lean counterparts. Leptin gene promoter DNA sequence region was analyzed ranging from transcription start site (TSS) to-550 bp length and found four CpGs in this sequence among them only three CpG loci (-309, -481, -502) were methylated in these WNIN mutant rat phenotypes. CONCLUSION: The increased percentage of methylation in WNIN mutant lean and carrier phenotypes is positively correlated with transcription levels. Thus genetic variation may have effect on methylation percentages and subsequently on the regulation of leptin gene expression which may lead to obesity in these obese mutant rat strains.

Progeria: a rare genetic premature ageing disorder.

Progeria is characterized by clinical features that mimic premature ageing. Although the mutation responsible for this syndrome has been deciphered, the mechanism of its action remains elusive. Progeria research has gained momentum particularly in the last two decades because of the possibility of revealing evidences about the ageing process in normal and other pathophysiological conditions. Various experimental models, both in vivo and in vitro, have been developed in an effort to understand the cellular and molecular basis of a number of clinically heterogeneous rare genetic disorders that come under the umbrella of progeroid syndromes (PSs). As per the latest clinical trial reports, Lonafarnib, a farnesyltranferase inhibitor, is a potent 'drug of hope' for Hutchinson-Gilford progeria syndrome (HGPS) and has been successful in facilitating weight gain and improving cardiovascular and skeletal pathologies in progeroid children. This can be considered as the dawn of a new era in progeria research and thus, an apt time to review the research developments in this area highlighting the molecular aspects, experimental models, promising drugs in trial and their implications to gain a better understanding of PSs.

Navigating the Commonality of Healthcare Failures: COVID-19 and Conflict Zones.

The weaknesses of healthcare systems have been sharply revealed amid the instability of the COVID-19 pandemic and the ongoing conflicts across the borders of different countries. One thing unites these two crises that appear to be separate: the incapacity of healthcare systems to provide for the most basic human requirements in emergency situations. With an emphasis on the roles of the United Nations and the World Health Organisation, we look into the similarities between healthcare failures in COVID-19 and conflict zones in this Editorial and offer possible solutions to improve the circumstances.

Plausible Role of Stem Cell Types for Treating and Understanding the Pathophysiology of Depression.

Major Depressive Disorder (MDD), colloquially known as depression, is a debilitating condition affecting an estimated 3.8% of the population globally, of which 5.0% are adults and 5.7% are above the age of 60. MDD is differentiated from common mood changes and short-lived emotional responses due to subtle alterations in gray and white matter, including the frontal lobe, hippocampus, temporal lobe, thalamus, striatum, and amygdala. It can be detrimental to a person's overall health if it occurs with moderate or severe intensity. It can render a person suffering terribly to perform inadequately in their personal, professional, and social lives. Depression, at its peak, can lead to suicidal thoughts and ideation. Antidepressants manage clinical depression and function by modulating the serotonin, norepinephrine, and dopamine neurotransmitter levels in the brain. Patients with MDD positively respond to antidepressants, but 10-30% do not recuperate or have a partial response accompanied by poor life quality, suicidal ideation, self-injurious behavior, and an increased relapse rate. Recent research shows that mesenchymal stem cells and iPSCs may be responsible for lowering depression by producing more neurons with increased cortical connections. This narrative review discusses the plausible functions of various stem cell types in treating and understanding depression pathophysiology.

Role of Phytomolecules in the Treatment of Obesity: Targets, Mechanisms and Limitations.

Obesity has become a worldwide health problem. It triggers additional co-morbidities like cardiovascular diseases, cancer, depression, sleep disorders, gastrointestinal problems and many more. Excess accumulation of fat in obesity could be caused by many factors like sedentary lifestyle, consumption of high-fat diet, genetic predisposition, etc. Imbalanced energy metabolism i.e., greater energy consumption than utilisation, invariably underlies obesity. Considering the high prevalence and continuous, uncontrolled increase of this major public health issue, there is an urgent need to find appropriate therapeutic agents with minimal or no side effects. The high prevalence of obesity in recent years has led to a surge in the number of drugs available in the market that claim to control obesity. Although there is a long list of medicines and management strategies that are available, selecting the right therapeutic intervention and feasible management of obesity is a challenge. Several phytochemicals like hydroxycitric acid, flavonoids, tannins, anthocyanins, phytohaemagglutinin, thymoquinone and epigallocatechin gallate have been shown to possess promising anti-obesity properties. However, studies providing information on how various phytochemicals exert their anti-obesity effects are inadequate. This calls for more experimentation in this less explored area of research. Additionally, the complication of obesity arises when it is a result of multiple factors and associated with a number of co-morbidities. In order to handle such complexities, combinatorial therapeutic interventions become effective. In this review, we have described the medicinal chemistry of different highly effective phytochemicals which can be used in the effective treatment and management of obesity.

Current Status of Drug Targets and Emerging Therapeutic Strategies in the Management of Alzheimer's Disease.

Alzheimer's disease (AD) is a chronic neurodegenerative disease affecting the elderly. AD is associated with a progressive decline in memory and cognitive abilities, drastic changes in behavioural patterns and other psychiatric manifestations. It leads to a significant decline in the quality of life at personal, household as well as national level. Although AD was described about hundred years back and multiple theories have been proposed, its exact pathophysiology is unknown. There is no cure for AD and the life expectancy of AD patients remains low at 3-9 years. An accurate understanding of the molecular mechanism(s) involved in the pathogenesis of AD is imperative to devise a successful treatment strategy. This review explains and summarises the current understanding of different therapeutic strategies based on various molecular pathways known to date. Different strategies based on anti-amyloid pathology, glutamatergic pathway, anti-tau, neuroprotection through neurotrophic factors and cholinergic neurotransmission have been discussed. Further, the use of anti-inflammatory drugs, nutraceuticals, and dietary interventions has also been explained in the management of AD. It further describes different pharmacological and dietary interventions being used in treating and/or managing AD. Additionally, this article provides a thorough review of the literature for improving the therapeutic paradigm of AD.

Prenatal and perinatal zinc restriction: effects on body composition, glucose tolerance and insulin response in rat offspring.

Maternal undernutrition increases the risk of adult chronic diseases, such as obesity and type 2 diabetes. This study evaluated the effect of maternal zinc restriction in predisposing the offspring to adiposity and altered insulin response in later life. Seventy-day-old female Wistar/NIN rats received a control (ZnC) or zinc-restricted (ZnR) diet for 2 weeks. Following mating with control males, a subgroup of the ZnR dams were rehabilitated with ZnC diet from parturition. Half the offspring born to the remaining ZnR dams were weaned onto the ZnC diet and the other half continued on the ZnR diet throughout their life. Body composition, glucose tolerance, insulin response and plasma lipid profile were assessed in male and female offspring at 3 and 6 months of age. The ZnR offspring weighed less than control offspring at birth and weaning and continued so until 6 months of age. Rehabilitation regimens corrected the body weights of male but not female offspring. Maternal zinc restriction increased the percentage of body fat and decreased lean mass, fat-free mass and fasting plasma insulin levels in both male and female offspring at 6 months of age. Also, glucose-induced insulin secretion was decreased in female but not male offspring. Despite the differences in fasting insulin and the area under the curve for insulin, the fasting glucose and the area under the curve for glucose were in general comparable among offspring of different groups. Rehabilitation from parturition or weaning partly corrected the changes in the percentage of body fat but had no such effect on other parameters. Changes in plasma lipid profile were inconsistent among the offspring of different groups. Thus chronic maternal zinc restriction altered the body composition and impaired the glucose-induced insulin secretion in the offspring.

Chronic transgenerational vitamin B12 deficiency of severe and moderate magnitudes modulates adiposity-probable underlying mechanisms.

We have demonstrated previously that severe but not moderate vitamin B12 deficiency altered body composition and induced adiposity in female C57BL/6 mice. This study aims to elucidate the effects of chronic transgenerational dietary vitamin B12 restriction on body composition and various biochemical parameters in the F1 generation offspring of our mouse models of severe and moderate vitamin B12 deficiency established earlier. Female weanling C57BL/6 mice received, ad libitum, for 4 weeks a (i) control diet, (ii) vitamin B12-restricted diet with pectin as dietary fiber (severely deficient diet), or (iii) vitamin B12-restricted diet with cellulose as dietary fiber (moderately deficient diet) and then mated with control males. The offspring of control and severely deficient dams continued on the respective diets of their mothers. Few moderately deficient dams were rehabilitated to control diet from parturition and their pups were weaned to control diet. Also, some offspring born to moderately B12 deficient dams were weaned to control diet, while others continued on the same diet as their mothers. Various parameters were determined in the F1 offspring after 12 and 36 weeks of feeding. The results indicate that both severe and moderate maternal vitamin B12 restrictions were associated with accelerated catch-up growth, increased body fat percentage, visceral adiposity, dyslipidemia, fasting hyperglycemia and insulin resistance in the F1 offspring. Inflammation, increased glucocorticoid and oxidative stress and poor antioxidant defence probably underlie these adverse effects. Rehabilitation from parturition but not weaning was beneficial in delaying the onset of the adverse outcomes in the offspring. © 2016 BioFactors, 43(3):400-414, 2017.

Effect of micronutrient supplement on health and nutritional status of schoolchildren: biochemical status.

OBJECTIVE: We assessed the effect of a daily intake of a micronutrient-fortified beverage for 14 mo on indicators of biochemical status of important micronutrients in schoolchildren. METHODS: A double-blind, placebo-controlled, matched-pair, cluster, randomization study design was used. Biochemical indicators of micronutrient status were evaluated at baseline and at the end of 14 mo on a subsample in nine matched pairs. Prevalence (percentage) of subclinical deficiency, mean, and mean increments of each indicator were compared between supplemented and placebo groups. RESULTS: Extent of inadequacy at baseline was more or less 100% for folic acid, 65% for vitamins B2 and B6, and 55% for vitamins C and A. Prevalence of anemia among subjects was 55%, with inadequacy of vitamin B12 being 40% and that of vitamin D being 30%. No subject had inadequacy of iodine based on urinary iodine. Supplementation of a micronutrient-enriched beverage for 14 mo significantly improved the status of many of the nutrients. The effect was significant with respect to vitamins A, B2, and B12, folic acid, vitamin D, parathyroid hormone, and thyroid-stimulating hormone in children who received the supplement compared with those who received only placebo. Hemoglobin status improved only in children who had anemia in the supplemented group. CONCLUSIONS: Prevalence of multiple subclinical micronutrient deficiencies are high in middle-income Indian school children. Daily consumption of a micronutrient-enriched beverage had positive effects that were confined to those nutrients that were inadequate at baseline.

Chronic low vitamin intake potentiates cisplatin-induced intestinal epithelial cell apoptosis in WNIN rats.

AIM: To investigate if cisplatin alters vitamin status and if VR modulates cisplatin induced intestinal apoptosis and oxidative stress in Wistar/NIN (WNIN) male rats. METHODS: Weanling, WNIN male rats (n = 12 per group) received adlibitum for 17 wk: control diet (20% protein) or the same with 50% vitamin restriction. They were then sub-divided into two groups of six rats each and administered cisplatin (2.61 mg/kg bodyweight) once a week for three wk or PBS (vehicle control). Intestinal epithelial cell (IEC) apoptosis was monitored by morphometry, Annexin-V binding, M30 cytodeath assay and DNA fragmentation. Structural and functional integrity of the villus were assessed by villus height/crypt depth ratio and activities of alkaline phosphatase, lys, ala-dipeptidyl amino-peptidase, respectively. To assess the probable mechanism(s) of altered apoptosis, oxidative stress parameters, caspase-3 activity, and expression of Bcl-2 and Bax were determined. RESULTS: Cisplatin per se decreased plasma vitamin levels and they were the lowest in VR animals treated with cisplatin. As expected VR increased only villus apoptosis, whereas cisplatin increased stem cell apoptosis in the crypt. However, cisplatin treatment of VR rats increased apoptosis both in villus and crypt regions and was associated with higher levels of TBARS, protein carbonyls and caspase-3 activity, but lower GSH concentrations. VR induced decrease in Bcl-2 expression was further lowered by cisplatin. Bax expression, unaffected by VR was increased on cisplatin treatment. Mucosal functional integrity was severely compromised in cisplatin treated VR-rats. CONCLUSION: Low intake of vitamins increases the sensitivity of rats to cisplatin and promotes intestinal epithelial cell apoptosis.

Severe but Not Moderate Vitamin B12 Deficiency Impairs Lipid Profile, Induces Adiposity, and Leads to Adverse Gestational Outcome in Female C57BL/6 Mice.

Vitamin B12 deficiency is widely prevalent in women of childbearing age, especially in developing countries. In the present study, through dietary restriction, we have established mouse models of severe and moderate vitamin B12 deficiencies to elucidate the impact on body composition, biochemical parameters, and reproductive performance. Female weanling C57BL/6 mice were fed for 4 weeks: (a) control AIN-76A diet, (b) vitamin B12-restricted AIN-76A diet with pectin as dietary fiber (severe deficiency group, as pectin inhibits vitamin B12 absorption), or (c) vitamin B12-restricted AIN-76A diet with cellulose as dietary fiber (moderate deficiency group as cellulose does not interfere with vitamin B12 absorption). After confirming deficiency, the mice were mated with male colony mice and maintained on their respective diets throughout pregnancy, lactation, and thereafter till 12 weeks. Severe vitamin B12 deficiency increased body fat% significantly, induced adiposity and altered lipid profile. Pregnant dams of both the deficient groups developed anemia. Severe vitamin B12 deficiency decreased the percentage of conception and litter size, pups were small-for-gestational-age and had significantly lower body weight at birth as well as weaning. Most of the offspring born to severely deficient dams died within 24 h of birth. Stress markers and adipocytokines were elevated in severe deficiency with concomitant decrease in antioxidant defense. The results show that severe but not moderate vitamin B12 restriction had profound impact on the physiology of C57BL/6 mice. Oxidative and corticosteroid stress, inflammation and poor antioxidant defense seem to be the probable underlying mechanisms mediating the deleterious effects.

Effects of vitamin restriction and supplementation on rat intestinal epithelial cell apoptosis.

Diet influences intestinal growth and function and vitamins modulate intestinal cell turnover. We have assessed the effects of chronic, moderate (50% of control) vitamin restriction and supplementation on intestinal epithelial cell (IEC) apoptosis and the relevance of this to alterations in tissue oxidative stress and antioxidant status. Feeding a vitamin-restricted diet to male, weanling WNIN rats for 20 weeks significantly increased IEC apoptosis, but only in the villi region, as evident from increased annexin V staining, M30 positivity, histological observations, DNA ladder formation, and reduced expression of Bcl-2. This was associated with elevated levels of lipid peroxides and protein carbonyls in the intestinal mucosa despite the increased activities of superoxide dismutase, catalase, and glutathione peroxidase. Consistent with the increased oxidative stress and apoptosis, structural and functional integrity of the villi were compromised as evident from the lowered ratio of villus height:crypt depth and the decreased activities of the membrane marker enzymes alkaline phosphatase and Lys-Ala dipeptidyl aminopeptidase. These changes were reversed by supplementation with a vitamin mixture or vitamin E alone, whereas riboflavin or folic acid supplementation reduced the apoptotic rates, but only partially. Further, oxidative stress was the least in vitamin E- or vitamin mixture-supplemented rats and correlated well with their IEC apoptotic rates. Increased tissue oxidative stress seems to mediate the vitamin-restriction-induced apoptosis of the IECs in rats.