Infrared Spectroscopic Studies on the Dipalmitoyl Phosphatidylcholine Bilayer Interactions with Calcium Phosphate: Effect of Vitamin D2

In the present work, the interaction of calcium-phosphate with DPPC (dipalmitoyl phosphatidylcholine) model membranes has been studied in the presence and absence of vitamin D2by using Fourier Transform Infrared (FTIR) spectroscopy. Calcium and phosphorus are the most abundant elements in the body. They combine in the form of calcium phosphate salt, called hydroxyapatite. Hydroxyapatite is the major structural component of the bone. Calcium phosphate assists with the digestion and absorption of food and is vitally important for the building of sturdy bone and body structures and a robust constitution. Phosphorus is extracted from foods and its use is controlled by vitamin D and calcium. FTIR spectral analysis results suggested that, calcium–phosphate complex, which is the major component of the bones, decreases the phase transition temperature to lower values, causes a loss in cooperativity of the acyl chains, decreases the order of the membrane in both phases and decreases the dynamics of the membrane in the liquid crystalline phase, increases the flexibility of the chains in the center of the bilayer in both phases, and increases the mobility of the head group of DPPC in the gel phase. The effect of calcium-phosphate on DPPC liposomes diminishes with the addition of vitamin D2into the liposomes. Our results suggest how calcium-phosphate and/or vitamin D2, which have indispensable role for the functioning of the bone tissue, affect the thermal behaviour of DPPC liposomes at molecular level.

Download Full-text

Lipid conformation in model membranes and biological membranes

Quarterly Reviews of Biophysics ◽

10.1017/s0033583500000305 ◽

1980 ◽

Vol 13 (1) ◽

pp. 19-61 ◽

Cited By ~ 589

Author(s):

Joachim Seelig ◽

Anna Seelig

Keyword(s):

Liquid Crystalline ◽

Double Helix ◽

Liquid Paraffin ◽

Biological Membranes ◽

Fatty Acyl ◽

Head Group ◽

Exact Nature ◽

Polar Head Group ◽

Acyl Chains ◽

Lipid Conformation

Protein molecules in solution or in protein crystals are characterized by rather well-defined structures in which α-helical regions, β-pleated sheets, etc., are the key features. Likewise, the double helix of nucleic acids has almost become the trademark of molecular biology as such. By contrast, the structural analysis of lipids has progressed at a relatively slow pace. The early X-ray diffraction studies by V. Luzzati and others firmly established the fact that the lipids in biological membranes are predominantly organized in bilayer structures (Luzzati, 1968). V. Luzzati was also the first to emphasize the liquid-like conformation of the hydrocarbon chains, similar to that of a liquid paraffin, yet with the average orientation of the chains perpendicular to the lipid–water interface. This liquid–crystalline bilayer is generally observed in lipid–water systems at sufficiently high temperature and water content, as well as in intact biological membranes under physiological conditions (Luzzati & Husson, 1962; Luzzati, 1968; Tardieu, Luzzati & Reman, 1973; Engelman, 1971; Shipley, 1973). In combination with thermodynamic and other spectroscopic observations these investigations culminated in the formulation of the fluid mosaic model of biological membranes (cf. Singer, 1971). However, within the limits of this model the exact nature of lipid conformation and dynamics was immaterial, the lipids were simply pictured as circles with two squiggly lines representing the polar head group and the fatty acyl chains, respectively. No attempt was made to incorporate the well-established chemical structure into this picture. Similarly, membrane proteins were visualized as smooth rotational ellipsoids disregarding the possibility that protruding amino acid side-chains and irregularities of the backbone folding may create a rather rugged protein surface.

Download Full-text

Concentration dependent different action of progesterone on the order, dynamics and hydration states of the head group of dipalmitoyl-phosphatidylcholine membrane

Spectroscopy An International Journal ◽

10.1155/2005/641043 ◽

2005 ◽

Vol 19 (4) ◽

pp. 213-219 ◽

Cited By ~ 4

Author(s):

Filiz Korkmaz ◽

Halil Kirbiyik ◽

Feride Severcan

Keyword(s):

Liquid Crystalline ◽

Membrane Dynamics ◽

Head Group ◽

Interfacial Region ◽

Progesterone Concentration ◽

Dramatic Decrease ◽

Physiological Level ◽

Dipalmitoyl Phosphatidylcholine ◽

Multilamellar Liposomes ◽

Linear Plot

Interactions of progesterone with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) multilamellar liposomes (MLVs) were investigated as a function of progesterone concentration at selected temperatures monitoring both the gel and liquid crystalline phase, by using Fourier Transform Infrared spectroscopy (FTIR). It has been show that the effect of progesterone on membrane dynamics is dependent on progesterone concentration. At 1 mol%, which is close to physiological level, progesterone behaves differently. At this concentration the decrease in dynamics is more noticeable. Additionally a dramatic decrease in the strength of hydrogen bonding in the interfacial region of the bilayer is also observed. When concentration increases up to 12 mol% opposite behaviour is observed at all interactions. Above 12 mol%, progesterone–DPPC interactions shows almost linear plot.

Download Full-text

Vitamin D2at high and low concentrations exert opposing effects on molecular order and dynamics of dipalmitoyl phosphatidylcholine membranes

Spectroscopy An International Journal ◽

10.1155/2001/890975 ◽

2001 ◽

Vol 15 (2) ◽

pp. 47-55 ◽

Cited By ~ 28

Author(s):

Nadide Kazanci ◽

Neslihan Toyran ◽

Parvez I. Haris ◽

Feride Severcan

Keyword(s):

Phase Transition ◽

Vitamin D ◽

Spectroscopic Studies ◽

Membrane Dynamics ◽

Transition Curve ◽

Interfacial Region ◽

High Concentration ◽

Dipalmitoyl Phosphatidylcholine ◽

Low Concentrations ◽

High Concentrations

Fourier Transform Infrared spectroscopic studies show that low concentrations of vitamin D2(1 and 3 mol %) does not induce significant change in the overall shape of the thermotropic profile of dipalmitoyl phosphatidylcholine (DPPC) membrane. In contrast, at higher concentrations of vitamin D2(9 and 12 mol %), the phase transition shifts to lower temperatures and a significant broadening in the phase transition curve is also observed. Low concentration of vitamin D2decreases the frequency of the CH2stretching mode, implying an ordering effect, whilst high concentration of vitamin D2disorders the system. Furthermore, at low and high concentrations, vitamin D2causes opposing effect on membrane dynamics. It decreases the bandwidth of the CH2stretching modes at low concentrations while increasing it at high concentrations. We have also observed different actions of vitamin D2at low and high concentrations in the deep interior and interfacial region of the membrane, by monitoring the frequency of the CH3stretching band and C=O stretching bands, respectively.

Download Full-text

Evaluation of the hormonal and biochemical changes in obese and non-obese PCOS Iraqi women before and after vitamin D supplementation

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v9i3.2 ◽

2019 ◽

Vol 9 (o3) ◽

Author(s):

Suaad Muhssen Ghazi ◽

Fatin Shallal Farhan

Keyword(s):

Vitamin D ◽

Serum Vitamin ◽

Follicular Development ◽

High Body Mass Index ◽

Vitamin D Supplementation ◽

The Body ◽

Obese People ◽

Serum Vitamin D ◽

Before And After ◽

Granulose Cells

Vitamin D deficiency is common in women with polycystic ovarian syndrome. Vitamin D plays an important physiologic role in reproductive functions of ovarian follicular development and luteinization through altering anti-müllerian hormone signaling, follicular stimulating hormone activity and progesterone production in human granulose cells. Vitamin D is precipitated in adipose fat tissues, making it notable to be used for the body as a result; obese people with high body mass index are already highly expected to have low levels of serum vitamin D.

Download Full-text

Interactions of Linear Analogues of Battacin with Negatively Charged Lipid Membranes

Membranes ◽

10.3390/membranes11030192 ◽

2021 ◽

Vol 11 (3) ◽

pp. 192

Author(s):

Kinga Burdach ◽

Dagmara Tymecka ◽

Aneta Urban ◽

Robert Lasek ◽

Dariusz Bartosik ◽

...

Keyword(s):

Lipid Membranes ◽

Liquid Crystalline ◽

Lipid Membrane ◽

Attenuated Total Reflection ◽

Gram Positive ◽

Insertion Depth ◽

Force Microscopy ◽

Acyl Chains ◽

Hydrophobic Portion ◽

Membrane Fluidization

The increasing resistance of bacteria to available antibiotics has stimulated the search for new antimicrobial compounds with less specific mechanisms of action. These include the ability to disrupt the structure of the cell membrane, which in turn leads to its damage. In this context, amphiphilic lipopeptides belong to the class of the compounds which may fulfill this requirement. In this paper, we describe two linear analogues of battacin with modified acyl chains to tune the balance between the hydrophilic and hydrophobic portion of lipopeptides. We demonstrate that both compounds display antimicrobial activity with the lowest values of minimum inhibitory concentrations found for Gram-positive pathogens. Therefore, their mechanism of action was evaluated on a molecular level using model lipid films mimicking the membrane of Gram-positive bacteria. The surface pressure measurements revealed that both lipopeptides show ability to bind and incorporate into the lipid monolayers, resulting in decreased ordering of lipids and membrane fluidization. Atomic force microscopy (AFM) imaging demonstrated that the exposure of the model bilayers to lipopeptides leads to a transition from the ordered gel phase to disordered liquid crystalline phase. This observation was confirmed by attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) results, which revealed that lipopeptide action causes a substantial increase in the average tilt angle of lipid acyl chains with respect to the surface normal to compensate for lipopeptide insertion into the membrane. Moreover, the peptide moieties in both molecules do not adopt any well-defined secondary structure upon binding with the lipid membrane. It was also observed that a small difference in the structure of a lipophilic chain, altering the balance between hydrophobic and hydrophilic portion of the molecules, results in different insertion depth of the active compounds.

Download Full-text

Prevention of Advanced Cancer by Vitamin D3 Supplementation: Interaction by Body Mass Index Revisited

Nutrients ◽

10.3390/nu13051408 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1408

Author(s):

Hermann Brenner ◽

Sabine Kuznia ◽

Clarissa Laetsch ◽

Tobias Niedermaier ◽

Ben Schöttker

Keyword(s):

Body Mass Index ◽

Vitamin D ◽

Cancer Patients ◽

Body Mass ◽

Advanced Cancer ◽

Vitamin D3 ◽

Normal Weight ◽

The Body ◽

Published Data ◽

Vitamin D3 Supplementation

Meta-analyses of randomized controlled trials (RCTs) have demonstrated a protective effect of vitamin D3 (cholecalciferol) supplementation against cancer mortality. In the VITAL study, a RCT including 25,871 men ≥ 50 years and women ≥ 55 years, protective effects of vitamin D3 supplementation (2000 IU/day over a median of 5.3 years) with respect to incidence of any cancer and of advanced cancer (metastatic cancer or cancer death) were seen for normal-weight participants but not for overweight or obese participants. We aimed to explore potential reasons for this apparent variation of vitamin D effects by body mass index. We conducted complementary analyses of published data from the VITAL study on the association of body weight with cancer outcomes, stratified by vitamin D3 supplementation. Significantly increased risks of any cancer and of advanced cancer were seen among normal-weight participants compared to obese participants in the control group (relative risk (RR), 1.27; 95% confidence interval (CI), 1.07–1.52, and RR, 1.44; 95% CI, 1.04–1.97, respectively). No such patterns were seen in the intervention group. Among those with incident cancer, vitamin D3 supplementation was associated with a significantly reduced risk of advanced cancer (RR, 0.86; 95% CI, 0.74–0.99). The observed patterns point to pre-diagnostic weight loss of cancer patients and preventive effects of vitamin D3 supplementation from cancer progression as plausible explanations for the body mass index (BMI)—intervention interactions. Further research, including RCTs more comprehensively exploring the potential of adjuvant vitamin D therapy for cancer patients, should be pursued with priority.

Download Full-text

Efficacy of weekly administration of cholecalciferol on parathyroid hormone in stable kidney-transplanted patients with CKD stage 1–3

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2020-0282 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Stefania Sella ◽

Luciana Bonfante ◽

Maria Fusaro ◽

Flavia Neri ◽

Mario Plebani ◽

...

Keyword(s):

Vitamin D ◽

Parathyroid Hormone ◽

Calcium Phosphate ◽

Serum Calcium ◽

Chronic Kidney Disease Stage ◽

Serum Vitamin ◽

Disease Stage ◽

Weekly Administration ◽

Ckd Stage ◽

Stage 1

AbstractObjectivesKidney transplant (KTx) recipients frequently have deficient or insufficient levels of serum vitamin D. Few studies have investigated the effect of cholecalciferol in these patients. We evaluated the efficacy of weekly cholecalciferol administration on parathyroid hormone (PTH) levels in stable KTx patients with chronic kidney disease stage 1–3.MethodsIn this retrospective cohort study, 48 stable KTx recipients (37 males, 11 females, aged 52 ± 11 years and 26 months post-transplantation) were treated weekly with oral cholecalciferol (7500–8750 IU) for 12 months and compared to 44 untreated age- and gender-matched recipients. Changes in levels of PTH, 25(OH) vitamin D (25[OH]D), serum calcium, phosphate, creatinine and estimated glomerular filtration rate (eGFR) were measured at baseline, 6 and 12 months.ResultsAt baseline, clinical characteristics were similar between treated and untreated patients. Considering the entire cohort, 87 (94.6%) were deficient in vitamin D and 64 (69.6%) had PTH ≥130 pg/mL. Serum calcium, phosphate, creatinine and eGFR did not differ between groups over the follow-up period. However, 25(OH)D levels were significantly higher at both 6 (63.5 vs. 30.3 nmol/L, p < 0.001) and 12 months (69.4 vs. 30 nmol/L, p < 0.001) in treated vs. untreated patients, corresponding with a significant reduction in PTH at both 6 (112 vs. 161 pg/mL) and 12 months (109 vs. 154 pg/mL) in treated vs. untreated patients, respectively (p < 0.001 for both).ConclusionsWeekly administration of cholecalciferol can significantly and stably reduce PTH levels, without any adverse effects on serum calcium and renal function.

Download Full-text

Vitamin D and sleep duration: Is there a bidirectional relationship?

Hormone Molecular Biology and Clinical Investigation ◽

10.1515/hmbci-2020-0025 ◽

2020 ◽

Vol 41 (4) ◽

Author(s):

Maryam Mosavat ◽

Aisling Smyth ◽

Diana Arabiat ◽

Lisa Whitehead

Keyword(s):

Vitamin D ◽

Sleep Duration ◽

Vitamin D Supplementation ◽

The Body ◽

Bone Homeostasis ◽

Limited Information ◽

Physiological Processes ◽

Vitamin D Levels ◽

Bidirectional Relationship ◽

Sleep Length

AbstractVitamin D contributes to numerous physiological processes within the body but primarily calcium and bone homeostasis. Emerging evidence highlights a novel role for vitamin D in maintaining and regulating optimal sleep. Sleep is a known regulator of bone health, highlighting the interconnectedness between vitamin D concentrations, sleep duration and bone metabolism. It is possible that the relationship between sleep length and vitamin D is bidirectional, with vitamin D playing a role in sleep health and conversely, sleep affecting vitamin D levels. Nevertheless, limited information on the direction of the interaction is available, and much remains to be learned concerning the complex relationship between insufficient sleep duration and vitamin D deficiency. Given the potential to implement interventions to improve sleep and vitamin D supplementation, understanding this relationship further could represent a novel way to support and improve health.

Download Full-text

Immunological Aspects of SARS-CoV-2 Infection and the Putative Beneficial Role of Vitamin-D

International Journal of Molecular Sciences ◽

10.3390/ijms22105251 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5251

Author(s):

Ming-Yieh Peng ◽

Wen-Chih Liu ◽

Jing-Quan Zheng ◽

Chien-Lin Lu ◽

Yi-Chou Hou ◽

...

Keyword(s):

Vitamin D ◽

Innate Immunity ◽

T Cells ◽

Adaptive Immunity ◽

Cd4 T Cells ◽

Vitamin D Supplementation ◽

The Body ◽

Alveolar Type ◽

Tissue Destruction ◽

Health Crisis

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is still an ongoing global health crisis. Immediately after the inhalation of SARS-CoV-2 viral particles, alveolar type II epithelial cells harbor and initiate local innate immunity. These particles can infect circulating macrophages, which then present the coronavirus antigens to T cells. Subsequently, the activation and differentiation of various types of T cells, as well as uncontrollable cytokine release (also known as cytokine storms), result in tissue destruction and amplification of the immune response. Vitamin D enhances the innate immunity required for combating COVID-19 by activating toll-like receptor 2. It also enhances antimicrobial peptide synthesis, such as through the promotion of the expression and secretion of cathelicidin and β-defensin; promotes autophagy through autophagosome formation; and increases the synthesis of lysosomal degradation enzymes within macrophages. Regarding adaptive immunity, vitamin D enhances CD4+ T cells, suppresses T helper 17 cells, and promotes the production of virus-specific antibodies by activating T cell-dependent B cells. Moreover, vitamin D attenuates the release of pro-inflammatory cytokines by CD4+ T cells through nuclear factor κB signaling, thereby inhibiting the development of a cytokine storm. SARS-CoV-2 enters cells after its spike proteins are bound to angiotensin-converting enzyme 2 (ACE2) receptors. Vitamin D increases the bioavailability and expression of ACE2, which may be responsible for trapping and inactivating the virus. Activation of the renin–angiotensin–aldosterone system (RAS) is responsible for tissue destruction, inflammation, and organ failure related to SARS-CoV-2. Vitamin D inhibits renin expression and serves as a negative RAS regulator. In conclusion, vitamin D defends the body against SARS-CoV-2 through a novel complex mechanism that operates through interactions between the activation of both innate and adaptive immunity, ACE2 expression, and inhibition of the RAS system. Multiple observation studies have shown that serum concentrations of 25 hydroxyvitamin D are inversely correlated with the incidence or severity of COVID-19. The evidence gathered thus far, generally meets Hill’s causality criteria in a biological system, although experimental verification is not sufficient. We speculated that adequate vitamin D supplementation may be essential for mitigating the progression and severity of COVID-19. Future studies are warranted to determine the dosage and effectiveness of vitamin D supplementation among different populations of individuals with COVID-19.

Download Full-text

Implications of Vitamin D Research in Chickens can Advance Human Nutrition and Perspectives for the Future

Current Developments in Nutrition ◽

10.1093/cdn/nzab018 ◽

2021 ◽

Author(s):

Matthew F Warren ◽

Kimberly A Livingston

Keyword(s):

Vitamin D ◽

Vitamin D Deficiency ◽

Vitamin D Supplementation ◽

The Body ◽

Human Nutrition ◽

Vitamin D Metabolites ◽

Vitamin D Metabolism ◽

Related Research ◽

Vitamin D Intake ◽

Increased Risk

Abstract The risk of vitamin D insufficiency in humans is a global problem that requires improving ways to increase vitamin D intake. Supplements are a primary means for increasing vitamin D intake, but without a clear consensus on what constitutes vitamin D sufficiency, there is toxicity risk with taking supplements. Chickens have been used in many vitamin D-related research studies, especially studies involving vitamin D supplementation. Our state-of-the-art review evaluates vitamin D metabolism and how the different hydroxylated forms are synthesized. We provide an overview with how vitamin D is absorbed, transported, excreted, and what tissues in the body store vitamin D metabolites. We also discuss a number of studies involving vitamin D supplementation with broilers and laying hens. Vitamin D deficiency and toxicity are also described and how they can be caused. The vitamin D receptor (VDR) is important for vitamin D metabolism. However, there is much more that can be understood with VDR in chickens. Potential research aims involving vitamin D and chickens should explore VDR mechanisms which could lead to newer insights with VDR. Utilizing chickens in future research to help with elucidating vitamin D mechanisms has great potential to advance human nutrition. Finding ways to increase vitamin D intake will be necessary because the coronavirus 2019 disease (COVID-19) pandemic is leading to increased risk of vitamin D deficiency in many populations. Chickens can provide a dual purpose with addressing pandemic-caused vitamin D deficiency: 1) vitamin D supplementation gives chickens added value with possibly leading to vitamin D-enriched meat and egg products; and 2) chickens’ use in research provides data for translational research. Expanding vitamin D-related research in chickens to include more nutritional aims in vitamin D status has great implications with developing better strategies to improve human health.

Download Full-text