Older Age Is Associated with Decreased Levels of VDR, CYP27B1, and CYP24A1 and Increased Levels of PTH in Human Parathyroid Glands

Target Values for 25-Hydroxy and 1,25-Dihydroxy Vitamin D Based on Their Associations with Inflammation and Calcium-Phosphate Metabolism

Target values for 25-hydroxy vitamin D and 1,25(OH)2D or 1,25-dihydroxy vitamin D remain a topic of debate among clinicians. We analysed data collected from December 2012 to April 2020 from two cohorts. Cohort A, comprising 455,062 subjects, was used to investigate the relationship between inflammatory indicators (white blood cell [WBC] count and C-reactive protein [CRP]) and 25(OH)D/1,25(OH)2D. Cohort B, including 47,778 subjects, was used to investigate the connection between 25(OH)D/1,25(OH)2D and mineral metabolism markers (phosphate, calcium, and intact parathyroid hormone [iPTH]). Quadratic models fit best for all tested correlations, revealing U-shaped relationships between inflammatory indicators and 25(OH)D and 1,25(OH)2D. Minimal CRP and WBC counts were observed at 1,25(OH)2D levels of 60 pg/mL and at 25(OH)D levels of 32 ng/mL, as well as of 42 ng/mL, respectively. iPTH correlated inversely with both 1,25(OH)2D and 25(OH)D, while phosphate as well as calcium levels positively correlated with both vitamin D forms. Calcium-phosphate product increased sharply when 25(OH)D was more than 50 ng/mL, indicating a possible risk for vascular calcification. Multiple regression analyses confirmed that these correlations were independent of confounders. This study suggests target values for 25(OH)D between 30-50 ng/mL and for 1,25(OH)2D between 50-70 pg/mL, based particularly on their associations with inflammation but also with mineral metabolism markers. These findings contribute to the ongoing discussion around ideal levels of vitamin D but require support from independent studies with data on clinical endpoints.

A hypothesis: MiRNA-124 mediated regulation of sirtuin 1 and vitamin D receptor gene expression accelerates aging

Objectives

Specific miRNAs are evident to be overexpressed with age, lifestyle, and environmental changes. Previous studies reported miR-124 overexpression in different scenarios in aged skin, age-related cognitive impairment, ischemic heart disease, muscle atrophy, and fractures. Thus miR-124 was considered to be a reliable miRNA target to establish a hypothesis on aging epigenome. Parallelly the hypothesis focuses on the expression of SIRT1 and VDR genes as a target for this specific miRNA expression as these genes were believed to be related to aging. This study aims to derive facts and evidence from past studies on aging. The objective was to establish a hypothetical linkage between miR-124 with age-related genes like SIRT1 and VDR.

Methods

An in silico search was performed in the TargetScan and miRbase databases to analyze the aging-associated miRNAs and their gene targets, the Python seaborn library was used, and the results were represented in terms of a bar plot.

Results

Based on an in silico analysis and studies available in the literature, we identified that miR-124-3p.1 and miR-124-3p.2 targets 3' UTR of VDR and SIRT1 genes, and hence thereby indicates that the miR-124 can regulate the expression of these genes. Further, few in vitro research studies have observed that miR-124 overexpression leads to the downregulation of VDR and SIRT1 gene expression. These results indicate that the suppression of these target genes accelerates early aging and age-related disorders.

Conclusions

Overall, this study hypothesizes that the overexpression of miR-124 diminishes the expression of VDR and SIRT1 genes, and thereby advances the process of aging, resulting in the development of age-associated complications.

Modulation of the vitamin D receptor by traditional Chinese medicines and bioactive compounds: potential therapeutic applications in VDR-dependent diseases

The Vitamin D receptor (VDR) is a crucial nuclear receptor that plays a vital role in various physiological functions. To a larger extent, the genomic effects of VDR maintain general wellbeing, and its modulation holds implications for multiple diseases. Current evidence regarding using vitamin D or its synthetic analogs to treat non-communicable diseases is insufficient, though observational studies suggest potential benefits. Traditional Chinese medicines (TCMs) and bioactive compounds derived from natural sources have garnered increasing attention. Interestingly, TCM formulae and TCM-derived bioactive compounds have shown promise in modulating VDR activities. This review explores the intriguing potential of TCM and bioactive compounds in modulating VDR activity. We first emphasize the latest information on the genetic expression, function, and structure of VDR, providing a comprehensive understanding of this crucial receptor. Following this, we review several TCM formulae and herbs known to influence VDR alongside the mechanisms underpinning their action. Similarly, we also discuss TCM-based bioactive compounds that target VDR, offering insights into their roles and modes of action.

Serum 25-hydroxyvitamin D, vitamin D receptor, and vitamin D binding protein concentrations in dogs with acute pancreatitis compared to healthy control dogs

BACKGROUND

Previous studies have documented vitamin D imbalance in dogs with acute pancreatitis (AP), but no studies have investigated serum vitamin D receptor (VDR) and vitamin D-binding protein (VDBP) concentrations.

OBJECTIVES

Compare serum 25-hydroxyvitamin D (25[OH]D), VDR, and VDBP concentrations in healthy dogs and dogs with AP and identify correlations between these concentrations with ionized calcium, C-reactive protein (CRP), and canine-specific pancreatic lipase (Spec cPL) concentrations.

ANIMALS

Twenty-two dogs with AP and 20 healthy control dogs.

METHODS

Prospective cross-sectional study. Serum 25(OH)D concentrations were measured using a chemiluminescence immunoassay, and VDR and VDBP concentrations were measured using a ELISA kit designed for dogs.

RESULTS

Serum concentrations of 25(OH)D were lower in dogs with AP (mean ± SD, 66.1 ± 39.2 ng/mL) than in controls (96.8 ± 30.4 ng/mL; P = .01), and VDR concentrations were lower in dogs with AP (5.3 ± 3.5 ng/mL) than in controls (7.4 ± 2.5 ng/mL; P = .03). No difference was observed in serum VDBP concentrations between the groups. Serum VDR concentrations differed between survivors (median [interquartile range] = 6.6 [4.3-8.2] ng/mL) and nonsurvivors (2.7 [0.5-3.5] ng/mL; P = .01). Negative correlations were observed among serum VDR, CRP (rs  = -0.55), and Spec cPL (rs  = -0.47) concentrations in dogs with AP.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with AP had lower serum 25(OH)D and VDR concentrations than controls. Additionally, our study suggests a potential role of VDR expression in the inflammatory process of AP in dogs.

Carving the senescent phenotype by the chemical reactivity of catecholamines: An integrative review

Macromolecules damaged by covalent modifications produced by chemically reactive metabolites accumulate in the slowly renewable components of living bodies and compromise their functions. Among such metabolites, catecholamines (CA) are unique, compared with the ubiquitous oxygen, ROS, glucose and methylglyoxal, in that their high chemical reactivity is confined to a limited set of cell types, including the dopaminergic and noradrenergic neurons and their direct targets, which suffer from CA propensities for autoxidation yielding toxic quinones, and for Pictet-Spengler reactions with carbonyl-containing compounds, which yield mitochondrial toxins. The functions progressively compromised because of that include motor performance, cognition, reward-driven behaviors, emotional tuning, and the neuroendocrine control of reproduction. The phenotypic manifestations of the resulting disorders culminate in such conditions as Parkinson's and Alzheimer's diseases, hypertension, sarcopenia, and menopause. The reasons to suspect that CA play some special role in aging accumulated since early 1970-ies. Published reviews address the role of CA hazardousness in the development of specific aging-associated diseases. The present integrative review explores how the bizarre discrepancy between CA hazardousness and biological importance could have emerged in evolution, how much does the chemical reactivity of CA contribute to the senescent phenotype in mammals, and what can be done with it.

Bone damage after chemotherapy for lymphoma: a real-world experience

BACKGROUND

Despite recent improvements in survival due to advances in treatment, the quality of life of patients with lymphoma may be compromised by the long-term complications of chemotherapy and steroid therapy. Among these, a potentially relevant problem is bone loss and the development of fragility fractures.

AIM

To provide further evidence of clinical or subclinical skeletal complications in correlation with biological variables and markers of bone disease in patients with complete response to therapy.

METHOD

A cross-sectional observational study was conducted on subjects diagnosed with lymphoma with subsequent antineoplastic treatment, disease status after therapy defined as complete response disease for at least a year now. We performed: blood chemistry tests, imaging techniques and screening tools for the assessment of functional status and quality of life (SARC-F and mini-Osteoporosis Quality of Life).

RESULTS

Approximately 50% of patients had osteoporosis, with a prevalence of vertebral fractures of 65.5%. In most patients, we found hypovitaminosis D and high levels of parathyroid hormone (PTH). Furthermore, a statistically significant association was observed between high PTH levels and previous lymphoma treatment. Finally, the Mini-Osteoporosis Quality of life (mini-OQLQ) questionnaire demonstrated a loss of quality of life as a consequence of the change in bone status.

CONCLUSIONS

Patient treatment design for personalized chemotherapy would be desirable to reduce late effects on bone. Also, early prevention programs need to be applied before starting treatment. The most benefited subpopulations could be not only elderly but also young patients.

The effect of hypervitaminosis D and intoxication on haematological parameters

BACKGROUND

This study aims to compare the haematological parameters of patients with very high and normal 25-hydroxyvitamin-D3 (25(OH)D3) levels.

METHODS

This study was designed as a retrospective cross-sectional study. The patients were divided into three groups according to their 25(OH)D3 levels: groups 1, 2 and 3 are patients with normal 25(OH)D3 levels (30-88 ng/mL), hypervitaminosis D (89-149 ng/mL) and vitamin D intoxication (>150 ng/mL), respectively. According to vitamin D levels, statistical analysis was performed by comparing the biochemical and haematological data between the groups.

RESULTS

This study evaluated 120 patients (40 patients) in three equal groups. A statistically significant difference was found between the three groups in haemoglobin (p = 0.03), haematocrit (p = 0.01), red blood cell levels (p = 0.03), leukocyte count (p < 0.001), neutrophil count (p < 0.001), lymphocyte count (p = 0.006), mean platelet volume (p = 0.04), and neutrophil/lymphocyte ratio (p = 0.03). In post hoc analysis, haemoglobin, haematocrit and RBC were significantly higher in group 1 than in group 3 (post hoc Tukey, p < 0.05). A statistically significant negative correlation was noted between 25(OH)D3 level and haemoglobin (r = -0.236), haemotocrit (r = -0.230), and red blood cell (r = -0.265) levels.

CONCLUSIONS

Vitamin D intoxication has been observed to affect haemoglobin, haematocrit, and RBC levels negatively. However, more studies are needed to clarify the effects and mechanisms of high vitamin D levels on the haematopoietic system.

Altered expression of the vitamin D metabolizing enzymes CYP27B1 and CYP24A1 under the context of prostate aging and pathologies

Low circulating levels of vitamin D are common at older ages and have been linked to an increased risk of prostate disease, including cancer. However, it has not yet been determined whether aging affects the ability of prostate cells to locally metabolize vitamin D into its active metabolite calcitriol and thus mediate the vitamin D signaling in autocrine and paracrine ways. By using a suitable rat model to interrogate spontaneous prostatic modifications over the course of aging, here we showed that both CYP27B1 and CYP24A1 enzymes, which are key players respectively involved with calcitriol synthesis and deactivation, were highly expressed in the prostate epithelium. Furthermore, as the animals aged, a drastic reduction of CYP27B1 levels was detected in total protein extracts and especially in epithelial areas of lesions, including tumors. On the other hand, CYP24A1 expression significantly increased with aging and remained elevated even in altered epithelia. Such intricate unbalance in regard to vitamin D metabolizing enzymes was strongly associated with reduced bioavailability of calcitriol in the senile prostate, which in addition to decreased expression of the vitamin D receptor, further limits the protective actions mediated by vitamin D signaling. This evidence was corroborated by the increased proliferative activity exactly at sites of lesions where the factors implicated with calcitriol synthesis and responsiveness had its expression inhibited. Taken together, our results emphasize a set of modifications over the course of aging with a high potential to hamper vitamin D signaling on the prostate. These findings highlight a crosstalk between vitamin D, aging, and prostate carcinogenesis, offering new potential targets in the prevention of malignancies and other aging-related disorders arising in the gland.

RISK OF HYPERCALCEMIA IN ELDERLY PATIENTS WITH HYPERVITAMINOSIS D AND INTOXICATION

OBJECTIVE

We aimed to determine the risk of hypercalcemia in a geriatric population with very high dose levels of 25-hydroxy-vitamin D (25(OH)D).

PATIENTS AND METHOD

This study was designed as a retrospective, cross-sectional two-center study for examining the elderly patients with very high 25(OH)D levels (>88ng/mL) between January 2014 and December 2019. After recruitment, subgroup analyses of the patients were performed based on their calcium and vitamin D levels.

RESULTS

A total of 81.101 elderly patients, who had been evaluated for their vitamin D levels, were screened. Of the 458 (0.6%) elderly patients with 25(OH)D>88 ng/mL according to our criteria, 217 patients with complete data were accepted into our study. The median 25(OH)D level was 103.7ng/mL (min-max:88.2-275.9). Most of the elderly patients (86.6%) with very high 25(OH)D levels were normocalcemic. When patients with hypercalcemia were compared with normocalcemic group, no difference was observed in the levels of 25(OH)D, intact parathormone (iPTH), phosphorus, alkaline phosphatase (ALP), and their age. However, the PTH suppression rate was significantly higher in hypercalcemic group (p=0.005).

CONCLUSION

The elderly patients with very high 25(OH)D levels would appear to be mostly normocalcemic whereas life-threatening hypercalcemia would also occur. Treatment and follow-up planning should be done according to the clinical guideline recommendations.

Prevalence and Determinants of a Blunted Parathyroid Hormone Response in Young Saudi Women with Vitamin D Deficiency: A Cross-Sectional Study

Vitamin D deficiency is highly prevalent among the Saudi population. Increased parathyroid hormone (PTH) secretion is an appropriate homeostatic response to correct the resultant hypocalcemia. However, not all vitamin D deficiency patients have increased PTH levels. This study determined the prevalence of a blunted PTH response to vitamin D deficiency among apparently healthy young Saudi women and assessed anthropometric and biochemical factors associated with this response by performing a secondary analysis of data obtained from a cross-sectional study conducted at the "Center of Excellence for Osteoporosis research." Overall, 315 women (aged 20-45 years) with vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) levels <30 nmol/L) were included. They were divided into two groups according to the laboratory cutoff value of PTH (<7 or ≥7 pmol/L), and anthropometric and biochemical characteristics of both groups were compared. Women with a blunted PTH response (n = 62, 19.7%) had a significantly lower body mass index (BMI) (P < 0.001) and smaller waist circumference (P=0.001). They also had significantly higher serum 25(OH)D (P=0.001), corrected serum calcium (P < 0.001), and phosphate (P=0.003) levels than those with an elevated PTH response (n = 253, 80.3%). Multiple logistic regression analysis showed that lower BMI (OR = 0.925; 95% CI: 0.949-0.987) and higher 25(OH)D (OR = 1.068; 95% CI: 1.014-1.124) and serum calcium (OR = 8.600; 95% CI: 1.614-45.809) levels were significantly associated with a blunted PTH response (R ² = 0.178). A blunted PTH response to vitamin D deficiency is mainly observed among women with lower BMI. Higher serum calcium and 25(OH)D levels and lower BMI were significant predictors of a blunted PTH response, which may indicate that these subjects are adapting to lower 25(OH)D levels and maintaining normal calcium levels without the need to increase PTH secretion. The mechanisms underlying this adaptation are unclear, and future studies to explore these mechanisms are warranted.

The importance of vitamin d metabolism as a potential prophylactic, immunoregulatory and neuroprotective treatment for COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has led to a declaration of a Public Health Emergency of International Concern by the World Health Organization. As of May 18, 2020, there have been more than 4.7 million cases and over 316,000 deaths worldwide. COVID-19 is caused by a highly infectious novel coronavirus known as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), leading to an acute infectious disease with mild-to-severe clinical symptoms such as flu-like symptoms, fever, headache, dry cough, muscle pain, loss of smell and taste, increased shortness of breath, bilateral viral pneumonia, conjunctivitis, acute respiratory distress syndromes, respiratory failure, cytokine release syndrome (CRS), sepsis, etc. While physicians and scientists have yet to discover a treatment, it is imperative that we urgently address 2 questions: how to prevent infection in immunologically naive individuals and how to treat severe symptoms such as CRS, acute respiratory failure, and the loss of somatosensation. Previous studies from the 1918 influenza pandemic have suggested vitamin D's non-classical role in reducing lethal pneumonia and case fatality rates. Recent clinical trials also reported that vitamin D supplementation can reduce incidence of acute respiratory infection and the severity of respiratory tract diseases in adults and children. According to our literature search, there are no similar findings of clinical trials that have been published as of July 1st, 2020, in relation to the supplementation of vitamin D in the potential prevention and treatment for COVID-19. In this review, we summarize the potential role of vitamin D extra-renal metabolism in the prevention and treatment of the SARS-CoV-2 infection, helping to bring us slightly closer to fulfilling that goal. We will focus on 3 major topics here: 1. Vitamin D might aid in preventing SARS-CoV-2 infection: Vitamin D: Overview of Renal and Extra-renal metabolism and regulation. Vitamin D: Overview of molecular mechanism and multifaceted functions beyond skeletal homeostasis. Vitamin D: Overview of local immunomodulation in human infectious diseases. Anti-viral infection. Anti-malaria and anti-systemic lupus erythematosus (SLE). 2. Vitamin D might act as a strong immunosuppressant inhibiting cytokine release syndrome in COVID-19: Vitamin D: Suppression of key pro-inflammatory pathways including nuclear factor kappa B (NF-kB), interleukin-6 (IL-6), and tumor necrosis factor (TNF). 3. Vitamin D might prevent loss of neural sensation in COVID-19 by stimulating expression of neurotrophins like Nerve Growth Factor (NGF): Vitamin D: Induction of key neurotrophic factors. .