Molecular insights into the pathogenic impact of vitamin D deficiency in neurological disorders

PEA-OXA restores cognitive impairments associated with vitamin D deficiency-dependent alterations of the gut microbiota

There is a growing evidence suggesting the association of vitamin D deficiency (VDD) and cognitive impairment. In this study we evaluated the possible involvement of gut microbiota in the cognitive impairments mediated by VDD and investigated the effects of pharmacological treatment with the oxazoline derivative of the aliamide palmitoylethanolamide, 2-Pentadecyl-2-oxazoline (PEA-OXA). Mice were submitted to behavioural, biochemical and electrophysiological analysis to assess whether their vitamin D status affected cognitive performance together with gut microbiota composition. In VDD mice we found cognitive malfunctioning associated with reduced neuroplasticity, indicated by impaired long term potentiation, and neuroinflammation at the hippocampal level. Importantly, PEA-OXA counteracted the cognitive impairments and modified the biochemical and functional changes induced by VDD. Additionally, PEA-OXA treatment enhanced gut microbiota diversity, which tended to be decreased by VDD only in female mice, elevated the relative abundance of lactic and butyric acid-producing families, i.e. Aerococcaceae and Butyricicoccaceae, and reversed the VDD-induced decrease of butyrate-producing beneficial genera, such as Blautia in female mice, and Roseburia in male mice. These data provide novel insights for a better understanding of the cognitive decline induced by VDD and related gut dysbiosis and its potential therapeutic treatment.

Vitamin D and ischemic stroke - Association, mechanisms, and therapeutics

Confronting the rising tide of ischemic stroke and its associated mortality and morbidity with ageing, prevention and acute management of ischemic stroke is of paramount importance. Mounting observational studies have established a non-linear association of vitamin D status with cardiovascular diseases, including ischemic stroke. Paradoxically, current clinical trials fail to demonstrate the cardiovascular benefits of vitamin D supplementation. We aim to update recent clinical and experimental findings on the role of vitamin D in the disease course of ischemic stroke, from its onset, progression, recovery, to recurrence, and the established and alternative possible pathophysiological mechanisms. This review justifies the necessities to address stroke etiological subtypes and focus on vitamin D-deficient subjects for investigating the potential of vitamin D supplementation as a preventive and therapeutic approach for ischemic stroke. Well-powered clinical trials are warranted to determine the efficacy, safety, timing, target individuals, optimal dosages, and target 25OHD concentrations of vitamin D supplementation in the prevention and treatment of ischemic stroke.

Tremendous Fidelity of Vitamin D3 in Age-related Neurological Disorders

Vitamin D3 (VD) is a secosteroid hormone and shows a pleiotropic effect in brain-related disorders where it regulates redox imbalance, inflammation, apoptosis, energy production, and growth factor synthesis. Vitamin D3's active metabolic form, 1,25-dihydroxy Vitamin D3 (1,25(OH)2D3 or calcitriol), is a known regulator of several genes involved in neuroplasticity, neuroprotection, neurotropism, and neuroinflammation. Multiple studies suggest that VD deficiency can be proposed as a risk factor for the development of several age-related neurological disorders. The evidence for low serum levels of 25-hydroxy Vitamin D3 (25(OH)D3 or calcidiol), the major circulating form of VD, is associated with an increased risk of Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), dementia, and cognitive impairment. Despite decades of evidence on low VD association with neurological disorders, the precise molecular mechanism behind its beneficial effect remains controversial. Here, we will be delving into the neurobiological importance of VD and discuss its benefits in different neuropsychiatric disorders. The focus will be on AD, PD, and HD as they share some common clinical, pathological, and epidemiological features. The central focus will be on the different attributes of VD in the aspect of its anti-oxidative, anti-inflammatory, anti-apoptotic, anti-cholinesterase activity, and psychotropic effect in different neurodegenerative diseases.

Analysis of MicroRNA-Transcription Factors Co-Regulatory Network Linking Depression and Vitamin D Deficiency

Depression and vitamin D deficiency are often co-occurring pathologies, the common pathogenetic ground of which includes an augmented inflammatory response. However, the molecular details of this relationship remain unclear. Here, we used a bioinformatic approach to analyze GEO transcriptome datasets of major depressive disorder (MDD) and vitamin D deficiency (VDD) to identify the hub genes within the regulatory networks of commonly differentially expressed genes (DEGs). The MDD-VDD shared regulatory network contains 100 DEGs (71 upregulated and 29 downregulated), with six hub genes (PECAM1, TLR2, PTGS2, LRRK2, HCK, and IL18) all significantly upregulated, of which PTGS2 (also known as COX2) shows the highest inference score and reference count. The subsequent analysis of the miRNA-transcription factors network identified COX2, miR-146a-5p, and miR-181c-5p as key co-regulatory actors in the MDD-VDD shared molecular pathogenic mechanisms. Subsequent analysis of published MDD and VDD transcriptome data confirmed the importance of the identified hub genes, further validating our bioinformatic analytical pipeline. Our study demonstrated that PTGS2 was highly upregulated in both depressive patients and patients with low vitamin D plasma levels. Therefore, regulators targeting PTGS2, like miR-146a-5p and miR181c-5p, may have great potential in controlling both diseases simultaneously, accentuating their role in future research.

Enhancing vitamin D3 - iron blends via twin-screw dry granulation: Microstructural properties and cellular uptake analysis of vitamin D3

The aim of this study was to develop vitamin D3 (VD3) and iron (Fe) blended granules using Neusilin® US2 as an excipient. A central composite design of experiments was used for the continuous manufacturing process, considering VD3 and iron as independent variables and the bulk density, flow index, oil holding capacity, and color difference as response variables. The addition of VD3 had a significant effect on the powder flow properties. The X-ray diffraction and Scanning electron microscopy-energy dispersive X-ray analysis validated the presence of VD3 and Fe in the granules, whereas the variations in porosity and roughness were demonstrated by tomography and atomic force microscopy, respectively. The in vitro cellular uptake profile confirmed the absorption of VD3 in the breast cancer cell line MCF-7 with apparent apoptosis. These results could help in scaling up the process from laboratory to pilot scale in twin-screw granulation and boost the intervention of VitD3/iron deficiencies.

Molecular Regulation of the CNS by Vitamin D

Vitamin D is a lipid-soluble vitamin that can be found in some foods. It is also produced endogenously (in the presence of ultraviolet light), transported through the blood to the targets organs and this is the reason to consider vitamin D as a hormone. It is known that vitamin D has genomic and non-genomic effects. This review is focused mainly on the vitamin D receptors, the importance of vitamin D as a neuromodulator, the role of vitamin D in the pathophysiology of devastating neurological disorders such as Alzheimer's disease, multiple sclerosis, amyotrophic lateral sclerosis, Parkinson's disease and the benefit of vitamin D and its derivates in alleviating these disorders.

Vitamin D, a Secosteroid Hormone and Its Multifunctional Receptor, Vitamin D Receptor, in Alzheimer's Type Neurodegeneration

Vitamin D is a secosteroid hormone exerting neurosteroid-like properties. Its well-known nuclear hormone receptor, and recently proposed as a mitochondrial transcription factor, vitamin D receptor, acts for its primary functions. The second receptor is an endoplasmic reticulum protein, protein disulfide isomerase A3 (PDIA3), suggested to act as a rapid response. Vitamin D has effects on various systems, particularly through calcium metabolism. Among them, the nervous system has an important place in the context of our subject. Recent studies have shown that vitamin D and its receptors have numerous effects on the nervous system. Neurodegeneration is a long-term process. Throughout a human life span, so is vitamin D deficiency. Our previous studies and others have suggested that the out-come of long-term vitamin D deficiency (hypovitaminosis D or inefficient utilization of vitamin D), may lead neurons to be vulnerable to aging and neurodegeneration. We suggest that keeping vitamin D levels at adequate levels at all stages of life, considering new approaches such as agonists that can activate vitamin D receptors, and utilizing other derivatives produced in the synthesis process with UVB are crucial when considering vitamin D-based intervention studies. Given most aspects of vitamin D, this review outlines how vitamin D and its receptors work and are involved in neurodegeneration, emphasizing Alzheimer's disease.