Vitamin D Deficiency: Effects on Oxidative Stress, Epigenetics, Gene Regulation, and Aging

The effect of vitamin E and selenium combination in repairing fluoride-induced DNA damage to NRK-52E cells

Prolonged and excessive fluoride exposure can lead to fluorosis. The kidney is one of the organs that are injured mostly due to fluoride-induced damage. Fluoride can induce DNA damage at cytotoxic concentrations. This study aims to determine the extent of NaF-induced DNA damage and to investigate the effect of vitamin E and selenium combination (ES) in preventing and repairing this damage. For this purpose, we administered different combinations of NaF and ES to NRK-52E cells and determined the effective concentrations of ES and the NaF IC₅₀ values associated with different incubation times (3, 12, and 24 h) by using the MTT assay. The determined quantities of NaF IC₅₀ in association with time and the NaF IC₅₀ + ES combination were administered to the cells. The extent of DNA damage was determined with the comet assay and the expression levels of the Ku70/80 and PARP-1 genes were determined with the RT-qPCR method. DNA damage significantly increased in all experimental groups compared to the control group (p < 0.05). It was found out that the NaF and ES combination statistically reduced the DNA damage compared to the damage observed in the NaF-treated groups (p < 0.05). Treatment of the ES combination significantly increased the expressions of Ku70 and Ku80 genes involved in DNA repair (p < 0.05). We concluded that vitamin E and selenium can potentially be effective in the repair of fluoride-induced DNA damage based on the results of this in vitro study. Our results may shed light on the prevention of DNA damage associated with fluorosis.

A meta-analysis of VDR polymorphisms and postmenopausal osteoporosis

BACKGROUND

Whether polymorphisms in VDR gene affect the risk of postmenopausal osteoporosis or not remain unclear. Thus, the authors performed a meta-analysis to more robustly assess associations between polymorphisms in VDR gene and the risk of postmenopausal osteoporosis by integrating the results of previous literature.

METHODS

Medline, Embase, Wanfang, VIP and CNKI were searched comprehensively for eligible literature, and 67 genetic association studies were finally selected to be included in this meta-analysis.

RESULTS

We found that ApaI rs7975232 (dominant comparison: OR = 0.77, P = 0.007; allele comparison: OR = 0.81, P = 0.04), BsmI rs1544410 (dominant comparison: OR = 0.69, P = 0.002; allele comparison: OR = 0.78, P = 0.008) and TaqI rs731236 (recessive comparison: OR = 1.32 , P = 0.01) polymorphisms were significantly associated with the risk of postmenopausal osteoporosis in Caucasians, whereas FokI rs10735810 polymorphism was significantly associated with the risk of postmenopausal osteoporosis in Asians (dominant comparison: OR = 0.61, P = 0.0001; recessive comparison: OR = 2.02, P = 0.001; allele comparison: OR = 0.68, P = 0.002).

CONCLUSIONS

This meta-analysis shows that ApaI rs7975232, BsmI rs1544410 and TaqI rs731236 polymorphisms may affect the risk of postmenopausal osteoporosis in Caucasians, while BsmI rs1544410 polymorphism may affect the risk of postmenopausal osteoporosis in Asians.

Cytokine storm in aged people with CoV-2: possible role of vitamins as therapy or preventive strategy

BACKGROUND

In December 2019, a novel human-infecting coronavirus, SARS-CoV-2, had emerged. The WHO has classified the epidemic as a "public health emergency of international concern". A dramatic situation has unfolded with thousands of deaths, occurring mainly in the aged and very ill people. Epidemiological studies suggest that immune system function is impaired in elderly individuals and these subjects often present a deficiency in fat-soluble and hydrosoluble vitamins.

METHODS

We searched for reviews describing the characteristics of autoimmune diseases and the available therapeutic protocols for their treatment. We set them as a paradigm with the purpose to uncover common pathogenetic mechanisms between these pathological conditions and SARS-CoV-2 infection. Furthermore, we searched for studies describing the possible efficacy of vitamins A, D, E, and C in improving the immune system function.

RESULTS

SARS-CoV-2 infection induces strong immune system dysfunction characterized by the development of an intense proinflammatory response in the host, and the development of a life-threatening condition defined as cytokine release syndrome (CRS). This leads to acute respiratory syndrome (ARDS), mainly in aged people. High mortality and lethality rates have been observed in elderly subjects with CoV-2-related infection.

CONCLUSIONS

Vitamins may shift the proinflammatory Th17-mediated immune response arising in autoimmune diseases towards a T-cell regulatory phenotype. This review discusses the possible activity of vitamins A, D, E, and C in restoring normal antiviral immune system function and the potential therapeutic role of these micronutrients as part of a therapeutic strategy against SARS-CoV-2 infection.

Oxidative Stress and Inflammation in COVID-19-Associated Sepsis: The Potential Role of Anti-Oxidant Therapy in Avoiding Disease Progression

Since the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak emerged, countless efforts are being made worldwide to understand the molecular mechanisms underlying the coronavirus disease 2019 (COVID-19) in an attempt to identify the specific clinical characteristics of critically ill COVID-19 patients involved in its pathogenesis and provide therapeutic alternatives to minimize COVID-19 severity. Recently, COVID-19 has been closely related to sepsis, which suggests that most deceases in intensive care units (ICU) may be a direct consequence of SARS-CoV-2 infection-induced sepsis. Understanding oxidative stress and the molecular inflammation mechanisms contributing to COVID-19 progression to severe phenotypes such as sepsis is a current clinical need in the effort to improve therapies in SARS-CoV-2 infected patients. This article aims to review the molecular pathogenesis of SARS-CoV-2 and its relationship with oxidative stress and inflammation, which can contribute to sepsis progression. We also provide an overview of potential antioxidant therapies and active clinical trials that might prevent disease progression or reduce its severity.

Implications of Oxidative Stress and Potential Role of Mitochondrial Dysfunction in COVID-19: Therapeutic Effects of Vitamin D

Due to its high degree of contagiousness and like almost no other virus, SARS-CoV-2 has put the health of the world population on alert. COVID-19 can provoke an acute inflammatory process and uncontrolled oxidative stress, which predisposes one to respiratory syndrome, and in the worst case, death. Recent evidence suggests the mechanistic role of mitochondria and vitamin D in the development of COVID-19. Indeed, mitochondrial dynamics contribute to the maintenance of cellular homeostasis, and its uncoupling involves pathological situations. SARS-CoV-2 infection is associated with altered mitochondrial dynamics with consequent oxidative stress, pro-inflammatory state, cytokine production, and cell death. Furthermore, vitamin D deficiency seems to be associated with increased COVID-19 risk. In contrast, vitamin D can normalize mitochondrial dynamics, which would improve oxidative stress, pro-inflammatory state, and cytokine production. Furthermore, vitamin D reduces renin–angiotensin–aldosterone system activation and, consequently, decreases ROS generation and improves the prognosis of SARS-CoV-2 infection. Thus, the purpose of this review is to deepen the knowledge about the role of mitochondria and vitamin D directly involved in the regulation of oxidative stress and the inflammatory state in SARS-CoV-2 infection. As future prospects, evidence suggests enhancing the vitamin D levels of the world population, especially of those individuals with additional risk factors that predispose to the lethal consequences of SARS-CoV-2 infection.

Vitamin D can be effective on the prevention of COVID-19 complications: A narrative review on molecular aspects

The widespread COVID-19 pandemic has been, currently, converted to a catastrophic human health challenge. Vitamin D (VD) and its metabolites have been used as a palliative treatment for chronic inflammatory and infectious diseases from ancient times. In the current study, some molecular aspects of the potential effects of VD against COVID-19 side-effects have been discussed. An arguable role in autophagy or apoptosis control has been suggested for VD through calcium signaling at the mitochondrial and ER levels. 1,25(OH)2D3 is also an immunomodulator that affects the development of B-cells, T-cells, and NK cells in both innate and acquired immunity. The production of some anti-microbial molecules such as defensins and cathelicidins is also stimulated by VD. The overexpression of glutathione, glutathione peroxidase, and superoxide dismutase, and down-regulation of NADPH oxidase are induced by VD to reduce the oxidative stress. Moreover, the multi-organ failure due to a cytokine storm induced by SARS-CoV2 in COVID-19 may be prevented by the immunomodulatory effects of VD. It can also downregulate the renin-angiotensin system which has a protective role against cardiovascular complications induced by COVID-19. Given the many experimental and molecular evidences due to the potential protective effects of VD on the prevention of the COVID-19-induced morbidities, a VD supplementation is suggested to prevent the lethal side-effects of the infection. It is particularly recommended in VD-deficient patients or those at greater risk of serious or critical effects of COVID-19, including the elderly, and patients with pre-existing chronic diseases, especially those in nursing homes, care facilities, and hospitals.

Ionizing Radiation as a Source of Oxidative Stress-The Protective Role of Melatonin and Vitamin D

Ionizing radiation (IR) has found widespread application in modern medicine, including medical imaging and radiotherapy. As a result, both patients and healthcare professionals are exposed to various IR doses. To minimize the negative side effects of radiation associated with oxidative imbalance, antioxidant therapy has been considered. In this review, studies on the effects of melatonin and vitamin D on radiation-induced oxidative stress are discussed. According to the research data, both substances meet the conditions for use as agents that protect humans against IR-induced tissue damage. Numerous studies have confirmed that melatonin, a hydro- and lipophilic hormone with strong antioxidant properties, can potentially be used as a radioprotectant in humans. Less is known about the radioprotective effects of vitamin D, but the results to date have been promising. Deficiencies in melatonin and vitamin D are common in modern societies and may contribute to the severity of adverse side effects of medical IR exposure. Hence, supporting supplementation with both substances seems to be of first importance. Interestingly, both melatonin and vitamin D have been found to selectively radiosensitise cancer cells, which makes them promising adjuvants in radiotherapy. More research is needed in this area, especially in humans.

Antioxidant nutrients and hemolysis in sickle cell disease

Hemolysis is one of the main pathophysiological characteristics of sickle cell disease (SCD) and might cause or could be the result of oxidative stress. Antioxidants are studied in SCD due to their potential to ensure redox balance and minimize deleterious effects on erythrocyte membranes. The objective of this systematic review was to evaluate the efficacy of antioxidant nutrient supplementation on reducing hemolysis in SCD patients through randomized clinical trials. We conducted our study according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses and the Cochrane Handbook for Systematic Reviews of Interventions investigating whether antioxidants could improve the hemolytic status of SCD patients. This study included 587 articles published until April 2020. We reduced this pool to 12 articles by excluding duplicates, reviews, comments, and studies with non-human subjects. Omega-3 fatty acids, vitamin A, and zinc were the antioxidants that reportedly improved the indirect hemolysis parameters such as hemoglobin, hematocrit, mean corpuscular volume, or red blood cells. High-dose vitamin C and E supplementation worsened hemolysis, causing increased reticulocytes, lactate dehydrogenase, indirect bilirubin, and haptoglobin. More intervention studies especially high-quality controlled randomized clinical trials are needed to investigate the effects of antioxidant nutrients in reducing hemolysis in SCD.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.

Vitamin D3 reduces risk of cardiovascular and liver diseases by lowering homocysteine levels: double-blinded, randomised, placebo-controlled trial

The objective of this study was to evaluate the effect of vitamin D3 on total homocysteine (tHcy) and C-reactive protein (CRP) levels and liver and kidney function tests in overweight women with vitamin D deficiency. Therefore, a randomised, double-blind placebo, controlled clinical trial was conducted on 100 eligible women. Subjects were randomly divided into two groups: the placebo (n 50) and the vitamin D (n 50) which received 1250 µg vitamin D3 per week for 2 months. The participants' 25-hydroxyvitamin D (25(OH)D), tHcy, CRP, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine and estimated glomerular filtration rate (eGFR) were measured and compared before and after treatment. Results showed that the tHcy, CRP, AST, ALT and eGFR levels after the 2nd month of vitamin D3 intervention were significantly (P < 0·001) decreased and the 25(OH)D, urea and creatinine levels were significantly (P < 0·001) increased in the treatment group. In the placebo group, no significant changes were identified throughout the follow-up period. In conclusion, vitamin D3 intervention with a treatment dose of 1250 µg/week for at least 2 months may help in lowering Hcy and CRP levels and may improve liver function tests, which in turn might help in minimising the risk of CVD and liver diseases among overweight women but negatively affect kidney function.

Klotho Pathways, Myelination Disorders, Neurodegenerative Diseases, and Epigenetic Drugs

In this review we outline a rationale for identifying neuroprotectants aimed at inducing endogenous Klotho activity and expression, which is epigenetic action, by definition. Such an approach should promote remyelination and/or stimulate myelin repair by acting on mitochondrial function, thereby heralding a life-saving path forward for patients suffering from neuroinflammatory diseases. Disorders of myelin in the nervous system damage the transmission of signals, resulting in loss of vision, motion, sensation, and other functions depending on the affected nerves, currently with no effective treatment. Klotho genes and their single-pass transmembrane Klotho proteins are powerful governors of the threads of life and death, true to the origin of their name, Fates, in Greek mythology. Among its many important functions, Klotho is an obligatory co-receptor that binds, activates, and/or potentiates critical fibroblast growth factor activity. Since the discovery of Klotho a little over two decades ago, it has become ever more apparent that when Klotho pathways go awry, oxidative stress and mitochondrial dysfunction take over, and age-related chronic disorders are likely to follow. The physiological consequences can be wide ranging, potentially wreaking havoc on the brain, eye, kidney, muscle, and more. Central nervous system disorders, neurodegenerative in nature, and especially those affecting the myelin sheath, represent worthy targets for advancing therapies that act upon Klotho pathways. Current drugs for these diseases, even therapeutics that are disease modifying rather than treating only the symptoms, leave much room for improvement. It is thus no wonder that this topic has caught the attention of biomedical researchers around the world.

Association between calcitriol and paricalcitol with oxidative stress in patients with hemodialysis

Background: The pathophysiological basis of chronic kidney disease and its complications, including cardiovascular disease, are associated with chronic inflammation and oxidative stress. We investigated the effects of active vitamin D (calcitriol) and synthetic vitamin D analog (paricalcitol) on oxidative stress in hemodialysis patients. Methods: This cross-sectional study was composed of 83 patients with a minimum hemodialysis vintage of one year. Patients with a history of any infection, malignancy, and chronic inflammatory disease were excluded. Oxidative markers (total oxidant and antioxidant status) and inflammation markers (C-reactive protein and interleukin-6) were analyzed. Results: A total of 47% (39/83) patients were using active or analog vitamin D. Total antioxidant status was significantly higher in patients with using active or analog vitamin D than those who did not use (p = 0.006). Whereas, total oxidant status and oxidative stress index were significantly higher in patients with not using vitamin D when compared with the patients who were using vitamin D preparation (p = 0.005 and p = 0.004, respectively). On the other hand, total antioxidant status, total oxidant status, and oxidative stress index were similar between patients who used active vitamin D or vitamin D analog (p = 0.6; p = 0.4 and p = 0.7, respectively). Conclusion: The use of active or selective vitamin D analog in these patients decreases total oxidant status and increases total antioxidant status. Also, paricalcitol is as effective as calcitriol in decreasing total oxidant status and increasing total antioxidant status in patients with chronic kidney disease.

Factors Affecting the Environmentally Induced, Chronic Kidney Disease of Unknown Aetiology in Dry Zonal Regions in Tropical Countries—Novel Findings

A new form of chronic tubulointerstitial kidney disease (CKD) not related to diabetes or hypertension appeared during the past four decades in several peri-equatorial and predominantly agricultural countries. Commonalities include underground stagnation of drinking water with prolonged contact with rocks, harsh climatic conditions with protracted dry seasons, and rampant poverty and malnutrition. In general, the cause is unknown, and the disease is therefore named CKD of unknown aetiology (CKDu). Since it is likely caused by a combination of factors, a better term would be CKD of multifactorial origin (CKDmfo). Middle-aged malnourished men with more than 10 years of exposure to environmental hazards are the most vulnerable. Over 30 factors have been proposed as causative, including agrochemicals and heavy metals, but none has been properly tested nor proven as causative, and unlikely to be the cause of CKDmfo/CKDu. Conditions such as, having favourable climatic patterns, adequate hydration, and less poverty and malnutrition seem to prevent the disease. With the right in vivo conditions, chemical species such as calcium, phosphate, oxalate, and fluoride form intra-renal nanomineral particles initiating the CKDmfo. This article examines the key potential chemical components causing CKDmfo together with the risk factors and vulnerabilities predisposing individuals to this disease. Research findings suggest that in addition to drinking water from stagnant sources that contain high ionic components, more than 10 years of exposure to environmental nephrotoxins and micronutrient malnutrition are needed to contract this fatal disease.

Diabetes Is Associated with Musculoskeletal Pain, Osteoarthritis, Osteoporosis, and Rheumatoid Arthritis

AIM

To investigate the associations between diabetes and musculoskeletal pain, osteoarthritis, osteoporosis, and rheumatoid arthritis.

METHODS

Self-reported data were provided by the nationwide Danish National Health Survey 2013. Inclusion criteria were age ≥ 40 years and known diabetes status. The exposure variable was diabetes, and the outcome variables included musculoskeletal pain during the last 14 days in three body sites (back/lower back, limbs, and shoulder/neck), osteoarthritis, osteoporosis, and rheumatoid arthritis. Logistic regression analyses adjusted for age, gender, BMI, education, marital status, and physical activity were performed.

RESULTS

9,238 participants with diabetes were 65.6 ± 11.0 (mean ± SD) years old; 55.6% were males. 99,980 participants without diabetes were 59.2 ± 11.8 years old; 46.7% were males. Diabetes was associated with back/lower back pain (OR 1.2 (CI 95% 1.1-1.2), p < 0.001), pain in the limbs (1.4 (1.3-1.4), p < 0.001), shoulder/neck pain (1.2 (1.1-1.3), p < 0.001), osteoarthritis (1.3 (1.2-1.4), p < 0.001), osteoporosis (1.2 (1.1-1.4), p = 0.010), and rheumatoid arthritis (1.6 (1.4-1.7), p < 0.001). In participants with diabetes, physical activity was associated with reduced pain (e.g., back/lower back pain (0.7 (0.6-0.7), p < 0.001)).

CONCLUSION

Diabetes was associated with elevated odds of having musculoskeletal pain. Diabetes was also associated with elevated odds of having osteoarthritis, osteoporosis, and rheumatoid arthritis. The most frequent disease in individuals with diabetes was osteoarthritis. The reported pain may have negative impacts on the level of physical activity. Health-care professionals should remember to inform patients with diabetes that musculoskeletal pain, osteoarthritis, osteoporosis, and rheumatoid arthritis are not contraindications to exercise training.

Antimicrobial and Immune-Modulatory Effects of Vitamin D Provide Promising Antibiotics-Independent Approaches to Tackle Bacterial Infections - Lessons Learnt from a Literature Survey

Antimicrobial multidrug-resistance (MDR) constitutes an emerging threat to global health and makes the effective prevention and treatment of many, particularly severe infections challenging, if not impossible. Many antibiotic classes have lost antimicrobial efficacy against a plethora of infectious agents including bacterial species due to microbial acquisition of distinct resistance genes. Hence, the development of novel anti-infectious intervention strategies including antibiotic-independent approaches is urgently needed. Vitamins such as vitamin D and vitamin D derivates might be such promising molecular candidates to combat infections caused by bacteria including MDR strains. Using the Pubmed database, we therefore performed an in-depth literature survey, searching for publications on the antimicrobial effect of vitamin D directed against bacteria including MDR strains. In vitro and clinical studies between 2009 and 2019 revealed that vitamin D does, in fact, possess antimicrobial properties against both Gram-positive and Gram-negative bacterial species, whereas conflicting results could be obtained from in vivo studies. Taken together, the potential anti-infectious effects for the antibiotic-independent application of vitamin D and/or an adjunct therapy in combination with antibiotic compounds directed against infectious diseases such as tuberculosis, H. pylori infections, or skin diseases, for instance, should be considered and further investigated in more detail.