Vitamin D receptor deficiency impairs inner ear development in zebrafish

The Relationship Between Lower Vitamin D Levels and Hearing Loss in Older Adults

BACKGROUND AND OBJECTIVES

Age-related hearing loss (ARHL) is a sensorineural disease that is associated with a number of factors. In addition to age, sex, environment, lifestyle, and comorbidities are all known to be related to ARHL as well. The prevalence of ARHL can be reduced by controlling the adjustable factors that cause it. Vitamin D levels are strongly related to calcium metabolism, which can affect ARHL. This study aimed to investigate the association between vitamin D and ARHL.

SUBJECTS AND METHODS

A total of 1,104 subjects aged >65 years were enrolled from the fifth Korean National Health and Nutrition Examination Survey, which was conducted from 2010-2012. Every participant received both an audiological assessment and a nutritional survey. The association between ARHL and serum vitamin D concentration was analyzed using logistic regression analyses with complex sampling adjusted for confounding factors such as alcohol consumption, smoking status, mobility, and bone mineral density.

RESULTS

Our multivariable analysis revealed that males in the group with lower serum levels of vitamin D (< 20 ng/mL) had a higher prevalence of ARHL (odds ratio, 1.638, 95% confidence interval, 1.058-2.538, p=0.027).

CONCLUSIONS

This finding suggests that lower serum levels of vitamin D are associated with ARHL in the older male population.

SOX2, JAGGED1, β-Catenin, and Vitamin D Receptor Expression Patterns during Early Development and Innervation of the Human Inner Ear

Sensorineural hearing loss can be caused by lesions to the inner ear during development. Understanding the events and signaling pathways that drive inner ear formation is crucial for determining the possible causes of congenital hearing loss. We have analyzed the innervation and expression of SOX2, JAGGED1, β-catenin (CTNNB1), and vitamin D receptor (VDR) in the inner ears of human conceptuses aged 5 to 10 weeks after fertilization (W) using immunohistochemistry. The prosensory domains of the human inner ear displayed SOX2 and JAGGED1 expression throughout the analyzed period, with SOX2 expression being more extensive in all the analyzed timepoints. Innervation of vestibular prosensory domains was present at 6 W and extensive at 10 W, while nerve fibers reached the base of the cochlear prosensory domain at 7-8 W. CTNNB1 and VDR expression was mostly membranous and present during all analyzed timepoints in the inner ear, being the strongest in the non-sensory epithelium. Their expression was stronger in the vestibular region compared to the cochlear duct. CTNNB1 and VDR expression displayed opposite expression trends during the analyzed period, but additional studies are needed to elucidate whether they interact during inner ear development.

Association of serum 25-hydroxyvitamins D2 and D3 with hearing loss in US adults: analysis from National Health and Nutrition Examination Survey, 2015-2016

Background

Hearing loss (HL) is increasingly recognized as a significant global public health issue, and research on its relationship with vitamin D levels has gained wider attention. However, the association between serum biomarkers 25-hydroxyvitamin D2 (25(OH)D2) and D3 (25(OH)D3) with different types of HL remains unclear. This study aimed to investigate the potential association of serum 25(OH)D2 and 25(OH)D3 with HL in US adults.

Methods

A sample of 3,684 individuals aged 20-69 years from the 2015-2016 National Health and Nutrition Examination (NHANES) was analyzed in this study. HL was defined as a pure tone average > 25 dB in either ear at low frequencies (500, 1,000, 2000 Hz), speech frequencies (500, 1,000, 2000, 4,000 Hz), and high frequencies (3,000, 4,000, 6,000, 8,000 Hz). Logistic regression was employed to examine the association between serum 25(OH)D2 and 25(OH)D3 and HL. The study population was then stratified by age, gender, race, and education level to analyze potential differences between adults in different subgroups.

Results

In the multivariate analysis, it was found that serum 25(OH)D2 was independently associated with low-frequency hearing loss (LFHL) (OR: 1.012 [95% CI, 1.005-1.020]) and speech-frequency hearing loss (SFHL) (OR: 1.011 [95% CI, 1.003-1.018]). Restrictive cubic spline analysis demonstrated a linear dose-response relationship between serum 25(OH)D2 levels and LFHL (p for linearity <0.001), as well as SFHL (p for linearity = 0.001). Conversely, an L-shaped association was observed between serum 25(OH)D3 levels and both LFHL (p for nonlinearity = 0.014) and SFHL (p for nonlinearity = 0.025), with threshold values identified at 35.3 and 36.5 nmol/L, respectively. Higher levels of serum 25(OH)D3 were associated with a lower probability of high-frequency hearing loss (HFHL) (OR: 0.994 [95% CI, 0.989-0.999]), with a threshold value identified at 53.9 nmol/L. Furthermore, a significant interaction between diabetes and serum 25(OH)D2 in LFHL was revealed through subgroup analysis (p = 0.041). In the non-diabetic population, serum 25(OH)D2 maintained its association with LFHL.

Conclusion

Our findings suggested a positive association between serum 25(OH)D2 concentrations and both LFHL and SFHL in the studied cohort. Additionally, an L-shaped relationship was found between serum 25(OH)D3 and LFHL and SFHL, and higher levels of serum 25(OH)D3 were identified to be associated with a lower risk of HFHL.

Vitamin D Deficiency as a Risk Factor of Tinnitus: An Epidemiological Study

OBJECTIVES

Vitamin D deficiency as a risk factor of tinnitus has not been well known. We tried to evaluate the association between the serum 25-(OH) vitamin D levels and tinnitus among the Korean population to propose the possible role of serum vitamin D in patients with tinnitus.

METHODS

This cross-sectional study investigated the potential risk factors of tinnitus in relation to serum 25(OH)D levels within the Korean population. It encompassed a health interview, nutrition assessment, and a health examination. Data was sourced from the KNHANES V (2010-2012), conducted by the Division of Health and Nutritional Survey under the Korean Centers for Disease Control and Prevention (KCDCP). Participants were chosen from various sampling units categorized by geography, gender, and age group. The selection was facilitated through household registries using a stratified, multistage, clustered probability sampling approach.

RESULTS

Data of 16 408 subjects were collected in this study. There were significant differences in gender, economic status, educational level, and sun exposure duration between the tinnitus and non-tinnitus groups. Serum 25(OH) vitamin D level between hearing loss and normal hearing was also significantly different. The logistic regression models with serum 25(OH) vitamin D quartile and tinnitus as the dependent variable, which were controlled for age, sex, smoking status, BMI, diabetes, hypertension, sun exposure, regular exercise, income, and education, eventually demonstrated that serum vitamin D deficiency and low sun exposure duration significantly increased the risk of tinnitus development.

CONCLUSION

This study demonstrated a significant association between serum vitamin D levels and tinnitus, driven by large epidemiological data. The results of our study provide baseline data for further research to investigate the role of vitamin D in the pathogenesis and management of tinnitus.

Knockdown of vitamin D receptor affects early stages of pectoral fin development in zebrafish

The vitamin D receptor (VDR) signalling has been implicated in vertebrate limb or fin formation. However, the involvement of VDR signalling in the early stages of limb/fin development remains to be elucidated. In this study, the role of VDR signalling in pectoral fin development was investigated in zebrafish embryos. Knockdown of vdr induced the severe impairment of pectoral fin development. The zebrafish larvae lacking vdr exhibited reduced pectoral fins with no skeletal elements. In situ hybridization revealed depletion of vdr downregulated fibroblast growth factor 24 (fgf24), a marker of early pectoral fin bud mesenchyme, in the presumptive fin field even before fin buds were visible. Moreover, a perturbed expression pattern of bone morphogenetic protein 4 (bmp4), a marker of the pectoral fin fold, was observed in the developing fin buds of zebrafish embryos that lost the vdr function. These findings suggest that VDR signalling is crucial in the early stages of fin development, potentially influencing the process by regulating other signalling molecules such as Fgf24 and Bmp4.

Association between Serum Vitamin D Levels and Risk of Sudden Sensorineural Hearing Loss: A cross-sectional Study

Background

Sudden sensorineural hearing loss (SSNHL) is an autoimmune diseases of the inner ear which is usually defined by acute onset of hearing loss in one or both ears, of 30 dB or more on at least three contiguous audiometric frequencies within 3 days or less. This study aimed to compare the serum levels of 25-hydroxyvitamin D (VitD) between patients with SSNHL and healthy controls.

Methods

A total of 50 patients with SSNHL and 50 healthy individuals without hearing loss as control group were enrolled in this study. Serum levels of VitD and other related laboratory tests such as calcium (Ca), phosphorus (P), and parathyroid hormone (PTH) were measured and compared between two study groups.

Results

Serum level of VitD was significantly lower in patients suffering from SSNHL compared to the healthy controls (26.55 ± 14.44 vs. 33.51 ± 14.21, P = 0.017, respectively). VitD insufficiency was observed in 70% (n = 35) of the patients with SSNHL as compared to 44% (n = 22) of healthy individuals, demonstrating a significant difference between two study groups. However, no statistically difference was observed for serum levels of Ca, P, and PTH.

Conclusion

This study indicated an increased prevalence of VitD insufficiency in subjects with SSNHL, suggesting a possible association between serum VitD levels and the development of SSNHL. VitD may protect the hearing loss through its antioxidant role.

Piscine Vitamin D Receptors Vdra/Vdrb in the Absence of Vitamin D Are Utilized by Grass Carp Reovirus for Promoting Viral Replication

The vitamin D receptor (VDR) plays a pivotal role in the biological actions of vitamin D (VitD). However, little is known about the functions of VDR in the production of viral inclusion bodies (VIBs). Using a representative strain of grass carp reovirus (GCRV) genotype I, GCRV-873, we show that GCRV-873 recruits grass carp Vdrs for promoting the production of VIBs in the absence of VitD. Inhibition of cholesterol synthesis by lovastatin impairs the production of VIBs and blocks the effects of grass carp Vdrs in promoting the production of VIBs in the absence of VitD. Furthermore, grass carp Vdrs are found to form the Vdra-Vdrb heterodimer, which is vital for 3-hydroxy-3-methylglutaryl-coenzyme A reductase (hmgcr)-dependent cholesterol synthesis and GCRV replication. Intriguingly in the presence of VitD, grass carp Vdra but not Vdrb forms the heterodimer with the retinoid X receptor beta b (Rxrbb), which induces the transcription of those genes involved in the RIG-I-like receptor (RLR) antiviral signaling pathway for inhibiting GCRV infection. Furthermore, the VitD-activated Vdra-Vdrb heterodimer attenuates the transcription of the RLR antiviral signaling pathway induced by VitD. In the presence of VitD, a balance between the Vdra-Rxrbb heterodimers as coactivators and Vdra-Vdrb heterodimers as corepressors in affecting the transcriptional regulation of the RLR antiviral signaling pathway may eventually determine the outcome of GCRV infection. Transfection with VitD can abolish the effect of grass carp Vdrs in promoting GCRV replication in a dose-dependent manner. Taken together, these findings demonstrate that GCRV utilizes host Vdrs to increase hmgcr-dependent cholesterol synthesis for promoting its replication, which can be prevented by VitD treatment. IMPORTANCE Grass carp reovirus (GCRV) is the causative agent of grass carp hemorrhagic disease, which seriously harms freshwater fish. Although many positive or negative regulators of GCRV infection have been identified in teleosts, little is known about the molecular mechanisms by which GCRV utilizes host factors to generate its infectious compartments beneficial for viral replication and infection. Here, we show that in the absence of VitD, the GCRV-873 strain utilizes host vitamin D receptors Vdra/Vdrb to increase hmgcr-dependent cholesterol synthesis for promoting the production of VIBs, which are important functional sites for aquareovirus replication and assembly. The negative regulation of Vdrs during viral infection can be prevented by VitD treatment. Thus, this present work broadens understanding of the pivotal roles of Vdrs in the interaction between the host and GCRV in the absence or presence of VitD, which might provide a rational basis for developing novel anti-GCRV strategies.

Serum fat-soluble vitamin levels may be related to sudden sensorineural hearing loss

BACKGROUND

Few related studies reported yet the association between vitamins and the onset of sudden sensorineural hearing loss (SSNHL).

OBJECTIVE

To explore the relationship between the serum levels of fat-soluble vitamins A, D, and E and the risk of SSNHL.

METHODS

This retrospective analysis included 310 SSNHL patients and 154 people without risk of hearing loss. The demographic information of all participants like age, gender, body mass index, occupation, cigarette smoking or drinking status, etc. were recorded. The serum levels of vitamins A, D, and E were determined using the electrochemical method.

RESULTS

The results indicated that serum vitamin D levels in SSNHL patients were significantly lower. Vitamin D deficiency was only observed in SSNHL group. Similarly, serum vitamin A levels in female SSNHL patients were significantly lower than the control group. Meanwhile, serum vitamin E levels in male SSNHL patients were significantly lower than the control group.

CONCLUSION AND SIGNIFICANCE

Our results revealed that the serum levels of fat-soluble vitamins A, D, and E in SSNHL patients were lower than those in the control group with normal hearing, indicating that the decrease of serum fat-soluble vitamins may be related to SSNHL pathogenesis.

Enhanced insulin activity achieved in VDRa/b ablation zebrafish

INTRODUCTION

1α,25-dihydroxyvitamin D3 (1α,25[OH]₂VD₃) is a hormone known for its key roles in calcium absorption and nutrient metabolism. In teleost fishes, 1α,25(OH)₂VD₃ insufficiency causes impaired glucose metabolism and lipid oxidation. However, the cascade and mechanisms of 1α,25(OH)₂VD₃ and the vitamin d receptor (VDR) signaling are unclear.

RESULTS

In this study, two genes (vdra and vdrb) encoding paralogs of VDRs were genetically knocked out in zebrafish. Growth retardation and accumulated visceral adipose tissue have been observed in vdra ^-/-;vdrb ^-/- deficient line. In the liver elevated accumulation of triglycerides and suppressed lipid oxidation were detected. Morover significantly elevated 1α,25(OH)₂VD₃ levels were detected in vdra^-/-;vdrb^-/- zebrafish due to cyp24a1 transcription repression. Furthermore VDRs ablation Enhanced insulin signaling including elevated insulin/insra trancriptional levels, glycolysis, lipogenesis and promoted AKT/mTOR activity.

DISCUSSION

In conclusion, our present studies provides a zebrafish model with an elevated 1α,25(OH)₂VD₃ levels in vivo. The 1α,25(OH)₂VD₃/VDRs signaling promote lipid oxidation activity. However 1α,25(OH)₂VD₃ activity of regulation of glucose homeostasis through Insulin/Insr was independent of nuclear VDRs in teleosts.

Bone-turnover biomarkers as potential prognostic factors in sudden sensorineural hearing loss: A prospective cohort study

Objectives

This study aims to explore the relationship between bone-turnover biomarkers and the recovery of SSNHL to provide clues for further improvements in etiological research and predictors.

Methods

The medical history, hearing thresholds, biomarkers of bone-turnover, and related hormones of 117 SSNHL patients were collected prospectively between August 2018 and December 2021. Linear correlation and logistic regression models were applied to examine the association between bone-turnover biomarkers and the prognosis of SSNHL.

Results

Age, the incidence of vertigo, pure tone average of the impaired frequencies (PTAimpairedfre), and the levels of bone turnover [including alkaline phosphatase (ALP), β-carboxy terminal crosslinked telopeptide of type 1 collagen (β-CTX), and N-terminal-midfragment of osteocalcin (N-MID)] were higher in the nonresponders than responders (P < 0.05). Logistic regression showed that the age (OR = 1.035, P = 0.027), time to treatment (OR = 1.157, P = 0.038), PTAimpairedfre (OR = 1.031, P = 0.008), and β-CTX (OR = 1.004, P = 0.001) were independent risk factors for the prognosis of SSNHL. In the women SSNHL subgroup, age, postmenopause percentage, PTAimpairedfre, the activity of ALP, levels of β-CTX, and N-MID were significantly higher in the nonresponders than the responders (P < 0.05). Compared to the men SSNHL subgroup, β-CTX has a higher correlation coefficient and predictive efficiency in the women SSNHL subgroup, and logistic regression showed that β-CTX (OR = 1.004, P = 0.004) was an independent risk factor for the women SSNHL.

Conclusions

Bone-turnover biomarkers are risk factors for poor prognosis in SSNHL, especially β-CTX. The differences were significant in women SSNHL, which may be related to the rapid regression of estrogen after menopause that leads to the occurrence of osteoporosis with a high conversion rate.

Chronic exposure to tralopyril induced abnormal growth and calcium regulation of turbot (Scophthalmus maximus)

Tralopyril is an emerging marine antifouling agent with limited data on its effects on fish growth and calcium regulation. To determine the changes induced by long-term exposure to tralopyril, multi-levels (such as molecular, biochemical, and individual levels) responses were measured in turbot at different concentrations (1 μg/L, 20 μg/L). The results showed that 1 μg/L mainly affected the immune response, while 20 μg/L affected the synthesis and metabolism of steroids and fat. However, different concentrations of tralopyril affected the synthesis, secretion and action of parathyroid hormone and growth hormone. The expression of GH/IGF axis gene and the level of growth hormone increased significantly, leading to abnormal growth. The energy tradeoff between immunity and growth at 1 μg/L tralopyril pressure may inhibit growth. The change of Ca²⁺ level was accompanied by the disturbance of PTH-related gene expression. The results of molecular docking showed that the disturbance of Ca²⁺ regulation might be attributed to the inhibition of vitamin D receptor by tralopyril, which affected the vitamin D signaling pathway. This study provides scientific data for the in-depth understanding and risk assessment of the toxicological effects of tralopyril and reveals the potential threat of tralopyril to environmental health.

The role of vitamin D in subjective tinnitus-A case-control study

Regarding the high prevalence of vitamin D (25(OH)D) deficiency in the population and its possible association with ear diseases, we aimed to investigate the 25(OH)Dserum level in patients with subjective, nonpulsating tinnitus and its effect on tinnitus severity. The study included 201 tinnitus patients and 99 controls. Patient clinical information, including tinnitus characteristics and severity according to Tinnitus Handicap Inventory (THI), loudness assessed by Visual Analogue Scale (VAS), audiometry, and the blood level of vitamin D, was recorded. The level of 25(OH)D in tinnitus patients was significantly decreased compared with the controls (19.86 ± 7.53 and 27.43 ± 8.85 ng/ml, respectively; P value < 0.0001). More patients in the tinnitus group were deficient in vitamin D, compared with the controls (50.7% vs. 22.2% respectively, p < 0.0001). Tinnitus patients with a lower serum level of 25(OH)D (≤15 ng/dl) were significantly younger, had a higher degree of tinnitus severity measured with THI and VAS scales, had higher triglyceride and TSH levels, and a lower HDL level compared with individuals who had higher 25(OH)D level (>15 ng/dl). There was a strong correlation between the 25(OH)D level and THI. Our findings suggest that a large proportion of tinnitus patients suffers from vitamin D deficiency and that the vitamin D level correlates with tinnitus impact. We recommend a vitamin D assessment for all tinnitus patients.

Polycyclic aromatic hydrocarbons modulate the activity of Atlantic cod (Gadus morhua) vitamin D receptor paralogs in vitro

Vitamin D receptor (VDR) mediates the biological function of the steroid hormone calcitriol, which is the metabolically active version of vitamin D. Calcitriol is important for a wide array of physiological functions, including calcium and phosphate homeostasis. In contrast to mammals, which harbor one VDR encoding gene, teleosts possess two orthologous vdr genes encoding Vdr alpha (Vdra) and Vdr beta (Vdrb). Genome mining identified the vdra and vdrb paralogs in the Atlantic cod (Gadus morhua) genome, which were further characterized regarding their phylogeny, tissue-specific expression, and transactivational properties induced by calcitriol. In addition, a selected set of polycyclic aromatic hydrocarbons (PAHs), including naphthalene, phenanthrene, fluorene, pyrene, chrysene, benzo[a]pyrene (BaP), and 7-methylbenzo[a]pyrene, were assessed for their ability to modulate the transcriptional activity of gmVdra and gmVdrb in vitro. Both gmVdra and gmVdrb were activated by calcitriol with similar potencies, but gmVdra produced significantly higher maximal fold activation. Notably, none of the tested PAHs showed agonistic properties towards the Atlantic cod Vdrs. However, binary exposures of calcitriol together with phenanthrene, fluorene, or pyrene, antagonized the activation of gmVdra, while chrysene and BaP significantly potentiated the calcitriol-mediated activity of both receptors. Homology modeling, solvent mapping, and docking analyses complemented the experimental data, and revealed a putative secondary binding site in addition to the canonical ligand-binding pocket (LBP). Calcitriol was predicted to interact with both binding sites, whereas PAHs docked primarily to the LBP. Importantly, our in vitro data suggest that PAHs can interact with the paralogous gmVdrs and interfere with their transcriptional activities, and thus potentially modulate the vitamin D signaling pathway and contribute to adverse effects of crude oil and PAH exposures on cardiac development and bone deformities in fish.

NCOA3 identified as a new candidate to explain autosomal dominant progressive hearing loss

Hearing loss is a frequent sensory impairment in humans and genetic factors account for an elevated fraction of the cases. We have investigated a large family of five generations, with 15 reported individuals presenting non-syndromic, sensorineural, bilateral and progressive hearing loss, segregating as an autosomal dominant condition. Linkage analysis, using SNP-array and selected microsatellites, identified a region of near 13 cM in chromosome 20 as the best candidate to harbour the causative mutation. After exome sequencing and filtering of variants, only one predicted deleterious variant in the NCOA3 gene (NM_181659, c.2810C > G; p.Ser937Cys) fit in with our linkage data. RT-PCR, immunostaining and in situ hybridization showed expression of ncoa3 in the inner ear of mice and zebrafish. We generated a stable homozygous zebrafish mutant line using the CRISPR/Cas9 system. ncoa3-/- did not display any major morphological abnormalities in the ear, however, anterior macular hair cells showed altered orientation. Surprisingly, chondrocytes forming the ear cartilage showed abnormal behaviour in ncoa3-/-, detaching from their location, invading the ear canal and blocking the cristae. Adult mutants displayed accumulation of denser material wrapping the otoliths of ncoa3-/- and increased bone mineral density. Altered zebrafish swimming behaviour corroborates a potential role of ncoa3 in hearing loss. In conclusion, we identified a potential candidate gene to explain hereditary hearing loss, and our functional analyses suggest subtle and abnormal skeletal behaviour as mechanisms involved in the pathogenesis of progressive sensory function impairment.

Low vitamin B12 level and vitamin D level adversely affect on cochlear health in women

The aim of this study is to examine the association between low serum vitamin B₁₂ levels and low serum vitamin D levels and cochlear health in women. A prospective case-control study was carried out in the Department of Otolaryngology, Malatya Training and Research Hospital between 2017-2018. Thirty (30) patients with vitamin B₁₂ deficiency (a mean age of 32.5 ± 1.7 years(y) women); 30 patients with vitamin D deficiency (a mean age of 32.3 ± 1.58 y women) and 30 controls (a mean age of 27.8 ± 1.48 y women) were recruited. The study participants have no evidence of symptomatic hearing loss. Transiently evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) of the study participants were recorded. A comparative analysis of the parameters revealed that results at TEOAE 1,2,3,4 kHz (p = 0.013, p = 0.002, p = 0.001, p = 0.001, respectively) and at DPOAE 1, 2, 6 kHz (p < 0.001, p < 0.001, p = 0.002, respectively) were somewhat lower in patients with vitamin B₁₂ deficient group when compared with the controls. Moreover, TEOAE 3,4 kHz (p = 0.005, p = 0.013 respectively) and DPOAE 1,2,6 kHz (p = 0.005, p = 0.01, p = 0.031, respectively) were lower in the vitamin D deficiency group compared with the controls. There was a significant association between both vitamin B₁₂ deficiency and vitamin D deficiency and cochlear health. Patients with vitamin B₁₂ and vitamin D deficiency should be evaluated for cochlear function.

Vitamin D Receptor Signaling Regulates Craniofacial Cartilage Development in Zebrafish

Vitamin D plays essential roles in supporting the skeletal system. The active form of vitamin D functions through the vitamin D receptor (VDR). A hereditary vitamin-D-resistant rickets with facial dysmorphism has been reported, but the involvement of VDR signaling during early stages of craniofacial development remains to be elucidated. The present study investigated whether VDR signaling is implicated in zebrafish craniofacial cartilage development using a morpholino-based knockdown approach. Two paralogous VDR genes, vdra and vdrb, have been found in zebrafish embryos. Loss-of-vdra has no discernible effect on cartilage elements, whereas loss-of-vdrb causes reduction and malformation of craniofacial cartilages. Disrupting both vdra and vdrb leads to more severe defects or complete loss of cartilage. Notably, knockdown of vdrb results in elevated expression of follistatin a (fsta), a bone morphogenetic protein (BMP) antagonist, in the adjacent pharyngeal endoderm. Taken together, these findings strongly indicate that VDR signaling is required for early craniofacial cartilage development in zebrafish.

Evaluation of Saccule Function in Patients with Vitamin D Deficiency

BACKGROUND AND OBJECTIVES

Considering important role of vitamin D in many physiological processes including vestibular system in the ear, aim of present study is to evaluate saccule function via cervical vestibular evoked myogenic potential (cVEMP), in patients with vitamin D deficiency. Subjects and.

METHODS

After routine audiological tests, cVEMP were recorded in 15 patients with vitamin D deficiency and 16 normal subjects. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. cVEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid muscle.

RESULTS

Mean of p13, n13, interpeak latencies and amplitude ratios were measured in both groups. Statistical analysis did not show differences between two groups.

CONCLUSIONS

Maybe serum 25-hydroxyvitamin D concentration was not low enough to have effect on saccule in the patients in present study or saccule have had low susceptibility to effects of vitamin D deficiency. For better judgment about effect of vitamin D deficiency on saccular function planning studies with high sample size is recommended.

Vitamin D is crucial for maternal care and offspring social behaviour in rats

Early life vitamin D plays a prominent role in neurodevelopment and subsequent brain function, including schizophrenic-like outcomes and increasing evidence for an association with autism spectrum disorder (ASD). Here, we investigate how early life vitamin D deficiency during rat pregnancy and lactation alters maternal care and influences neurodevelopment and affective, cognitive and social behaviours in male adult offspring. Sprague-Dawley rats were placed on either a vitamin D control (2195 IU/kg) or deficient diet (0 IU/kg) for five weeks before timed mating, and diet exposure was maintained until weaning of offspring on postnatal day (PND) 23. MRI scans were conducted to assess brain morphology, and plasma corticosterone levels and neural expression of genes associated with language, dopamine and glucocorticoid exposure were characterised at PND1, PND12 and 4 months of age. Compared to controls, vitamin D-deficient dams exhibited decreased licking and grooming of their pups but no differences in pup retrieval. Offspring neurodevelopmental markers were unaltered, but vitamin D-deficient pup ultrasonic vocalisations were atypical. As adults, males that had been exposed to vitamin D deficiency in early life exhibited decreased social behaviour, impaired learning and memory outcomes and increased grooming behaviour, but unaltered affective behaviours. Accompanying these behavioural changes was an increase in lateral ventricle volume, decreased cortical FOXP2 (a protein implicated in language and communication) and altered neural expression of genes involved in dopamine and glucocorticoid-related pathways. These data highlight that early life levels of vitamin D are an important consideration for maternal behavioural adaptations as well as offspring neuropsychiatry.

Vitamin D receptor expression is essential during retinal vascular development and attenuation of neovascularization by 1, 25(OH)2D3

Vitamin D provides a significant benefit to human health, and its deficiency has been linked to a variety of diseases including cancer. Vitamin D exhibits anticancer effects perhaps through inhibition of angiogenesis. We previously showed that the active form of vitamin D (1, 25(OH)2D3; calcitriol) is a potent inhibitor of angiogenesis in mouse model of oxygen-induced ischemic retinopathy (OIR). Many of vitamin D's actions are mediated through vitamin D receptor (VDR). However, the role VDR expression plays in vascular development and inhibition of neovascularization by 1, 25(OH)2D3 remains unknown. Here using wild type (Vdr +/+) and Vdr-deficient (Vdr -/-) mice, we determined the impact of Vdr expression on postnatal development of retinal vasculature and retinal neovascularization during OIR. We observed no significant effect on postnatal retinal vascular development in Vdr -/- mice up to postnatal day 21 (P21) compared with Vdr +/+ mice. However, we observed an increase in density of pericytes (PC) and a decrease in density of endothelial cells (EC) in P42 Vdr -/- mice compared with Vdr +/+ mice, resulting in a significant decrease in the EC/PC ratio. Although we observed no significant impact on vessel obliteration and retinal neovascularization in Vdr -/- mice compared with Vdr +/+ mice during OIR, the VDR expression was essential for inhibition of retinal neovascularization by 1, 25(OH)2D3. In addition, the adverse impact of 1, 25(OH)2D3 treatment on the mouse bodyweight was also dependent on VDR expression. Thus, VDR expression plays a significant role during retinal vascular development, especially during maturation of retinal vasculature by promoting PC quiescence and EC survival, and inhibition of ischemia-mediated retinal neovascularization by 1, 25(OH)2D3.

Vitamin D and regulation of vascular cell function

Vitamin D deficiency is linked to pathogenesis of many diseases including cardiovascular, cancer, and various eye diseases. In recent years, important roles for vitamin D in regulation of immune function, inflammation, angiogenesis, and aging have been demonstrated. Thus, vitamin D and its analogs have been evaluated for the treatment of various types of cancer and chronic diseases. We have previously shown that the active form of vitamin D [1,25(OH)₂D₃] is a potent inhibitor of angiogenesis. This activity is consistent with the important role proposed for vitamin D and its analogs in the mitigation of tumor growth through inhibition of angiogenesis. Here, we review the important nutritional value of vitamin D and the abnormalities linked to its deficiency. We will explore its potential role as a regulator of angiogenesis and vascular cell function and the role vitamin D receptor (VDR) expression plays in these activities during vascular development and neovascularization. Our studies have established an important role for 1,25(OH)₂D₃ and VDR in the regulation of perivascular supporting cell function. In addition, the interaction of 1,25(OH)₂D₃ and VDR is essential for these activities and inhibition of neovascularization. Delineating the signaling pathways involved and identification of genes that are the target of 1,25(OH)₂D₃ regulation in vascular cells will allow us to identify novel pathways that are targets for regulation of vascular function and angiogenesis.