Effects of taurine supplementation on productive performance,nutrient digestibility and gene expression of nutrient transporters in quails reared under heat stress

This study was conducted to examine the effects of dietary taurine supplementation on productive performance, nutrient digestibility, antioxidant status, and the gene expression of ileal nutrient transporters in laying quails reared under heat stress (HS). One hundred and eighty laying Japanese quails (Coturnix coturnix japonica) were fed a basal diet or basal diet supplemented with either 2.5 or 5 g of taurine per kg of diet, and reared at either 22 ± 2 °C for 24 h/d (thermoneutral, TN) or 34 ± 2 °C for 8 h/d (HS) for 12 weeks. The quails reared under HS consumed less feed, produced less egg, and had lower dry matter, organic matter and crude protein apparent digestibilities compared with the quails reared under the TN condition (P = 0.001). However, increasing taurine concentrations in the diet improved feed intake and egg production (P = 0.001), but also the apparent digestibilities (P ≤ 0.027) in quails reared under HS. The greater doses (5 g/kg) of taurine resulted in more responses. The quails reared under HS had greater serum and liver MDA concentrations (P = 0.0001) which decreased with dietary taurine supplementations, particularly greater doses. The gene expressions of ileal PEPT1, EAAT3, CAT1, CAT2, SGLT1, SGLT5, GLUT2, and GLUT5 decreased under HS conditions (P = 0.001). However, supplementing taurine, in a dose-dependent fashion, to the diet of quails reared under HS resulted in increases in the gene expressions of the transporters (P < 0.05) except for CAT1. The results of the present work showed that taurine supplementation, particularly with greater doses (5 g/kg), to the diet of laying quails kept under HS acts as alleviating negative effects of HS, resulting in improvements in productive performance and nutrient digestion, and also upregulation of ileal nutrient transporters.     

Regulation of nutrient transporters by metabolic and environmental stresses

The yeast plasma membrane is a selective barrier between an erratic environment and the cell's metabolism. Nutrient transporters are the gatekeepers that control the import of molecules feeding into the metabolic pathways. Nutrient import adjusts rapidly to changes in metabolism and the environment, which is accomplished by regulating the surface expression of transporters. Recent studies indicate that the lipid environment in which transporters function regulates ubiquitination efficiency and endocytosis of these proteins. Changes in the lipid environment are caused by lateral movements of the transporters between different membrane domains and by the influence of the extracellular environment on the fluidity of the plasma membrane.     

1-Deoxysphinganine initiates adaptive responses to serine and glycine starvation in cancer cells via proteolysis of sphingosine kinase

Cancer cells may depend on exogenous serine, depletion of which results in slower growth and activation of adaptive metabolic changes. We previously demonstrated that serine and glycine (SG) deprivation causes loss of sphingosine kinase 1 (SK1) in cancer cells, thereby increasing the levels of its lipid substrate, sphingosine (Sph), which mediates several adaptive biological responses. However, the signaling molecules regulating SK1 and Sph levels in response to SG deprivation have yet to be defined. Here, we identify 1-deoxysphinganine (dSA), a noncanonical sphingoid base generated in the absence of serine from the alternative condensation of alanine and palmitoyl CoA by serine palmitoyl transferase, as a proximal mediator of SG deprivation in SK1 loss and Sph level elevation upon SG deprivation in cancer cells. SG starvation increased dSA levels in vitro and in vivo and in turn induced SK1 degradation through a serine palmitoyl transferase-dependent mechanism, thereby increasing Sph levels. Addition of exogenous dSA caused a moderate increase in intracellular reactive oxygen species, which in turn decreased pyruvate kinase PKM2 activity while increasing phosphoglycerate dehydrogenase levels, and thereby promoted serine synthesis. We further showed that increased dSA induces the adaptive cellular and metabolic functions in the response of cells to decreased availability of serine likely by increasing Sph levels. Thus, we conclude that dSA functions as an initial sensor of serine loss, SK1 functions as its direct target, and Sph functions as a downstream effector of cellular and metabolic adaptations. These studies define a previously unrecognized “physiological” nontoxic function for dSA.     

Glycosylation is a novel TGFβ1-independent post-translational modification of Smad2

Smad2 is a crucial component of intracellular signaling by transforming growth factor-β (TGFβ). Here we describe that Smad2 is glycosylated, which is a novel for Smad2 post-translational modification. We showed that the Smad2 glycosylation was inhibited upon treatment of cells with 17β-estradiol, and was enhanced in cells in a dense culture as compared to cells in a sparse culture. The Smad2 glycosylation was not dependent on the C-terminal phosphorylation of Smad2, and was not affected by TGFβ1 treatment of the cells. Smad2 was glycosylated at multiple sites, and one of the predicted sites is Serine110. Thus, Smad2 is glycosylated, and this post-translational modification was modulated by 17β-estradiol but not by TGFβ1.     

Bone Mineral Density of the 1/3 Radius Refines Osteoporosis Diagnosis,Correlates With Prevalent Fractures,and Enhances Fracture Risk Estimates

ObjectiveTo investigate the added value of 1/3 radius (1/3R) for the diagnosis of osteoporosis by spine and hip sites and its correlation with prevalent fractures and predicted fracture risk.MethodsFracture Risk Assessment Tool (FRAX) scores for hip and major osteoporotic fractures (MOF) with/without trabecular bone score were considered proxy for fracture risk. The contribution of 1/3R to risk prediction was depicted via linear regression models with FRAX score as the dependent variable—first only with central and then with radius T-score as an additional covariate. Significance of change in the explained variance was compared by F-test.ResultsThe study included 1453 patients, 86% women, aged 66 ± 10 years. A total of 32% (n = 471) were osteoporotic by spine/hip and 8% (n = 115) by radius only, constituting a 24.4% increase in the number of subjects defined as osteoporotic (n = 586, 40%). Prior fracture prevalence was similar among patients with osteoporosis by spine/hip (17.4%) and radius only (19.1%) (P = .77).FRAX prediction by a regression model using spine/hip T-score yielded explained variance of 51.8% and 49.9% for MOF and 39.8% and 36.4% for hip (with/without trabecular bone score adjustment, respectively). The contribution of 1/3R was statistically significant (P < .001) and slightly increased the explained variance to 52.3% and 50.4% for MOF and 40.9% and 37.4% for hip, respectively.ConclusionReclassification of BMD results according to radius measurements results in higher diagnostic output. Prior fractures were equally prevalent among patients with radius-only and classic-site osteoporosis. FRAX tool performance slightly improved by incorporating radius BMD. Whether this approach may lead to a better fracture prediction warrants further prospective evaluation.     

Cancer/testis antigen LDHC promotes proliferation and metastasis by activating the PI3K/Akt/GSK-3β-signaling pathway and the in lung adenocarcinoma

The cancer/testis antigen lactate dehydrogenase-C4 (LDHC) is a specific isoenzyme of the LDH family that regulates invasion and metastasis in some malignancies; however, little is known regarding its role in progression of lung adenocarcinoma (LUAD). Thus, we investigated LDHC expression by immunohistochemistry, and analyzed its clinical significance in 88 LUAD specimens. The role and molecular mechanisms subserving LDHC in cellular proliferation, migration, and invasion were explored both in vitro and in vivo. As a result, we found that high LDHC expression was significantly correlated with clinicopathological features of aggressive LUAD and a poor prognosis. Overexpression of LDHC induced LUAD cells to produce lactate and ATP, increased their metastatic and invasive potential—, and accelerated xenograft tumor growth. We further demonstrated that overexpression of LDHC affected the expression of cell proliferation-related proteins (cyclin D1 and c-Myc) and epithelial-mesenchymal transition (EMT)-related proteins (MMP-2, MMP-9, E-cadherin, Vimentin, Twist, Slug, and Snail) both in vitro and in vivo. Finally, excessive activation of LDHC enhanced the phosphorylation levels of AKT and GSK-3β, revealing activation of the PI3K/Akt/GSK-3β oncogenic-signaling pathways. Treatment with a PI3K inhibitor reversed the effects of LDHC overexpression by inhibiting cellular proliferation, migration, and invasion, with diminished levels of p-Akt and p-GSK3β. PI3K inhibition also reversed cell proliferation-related and EMT-related proteins in LDHC-overexpressing A549 cells. In conclusion, LDHC promotes proliferation, migration, invasion, and EMT in LUAD cells via activation of the PI3K/Akt/GSK-3β pathway.     

Systemic levels of the soluble co-inhibitory immune checkpoints,CTLA-4, LAG-3, PD-1/PD-L1 and TIM-3 are markedly increased in basal cell carcinoma

Although co-inhibitory immune checkpoint proteins are primarily involved in promoting cell-cell interactions that suppress adaptive immunity, especially tumor immunity, the soluble cell-free variants of these molecules are also detectable in the circulation of cancer patients where they retain immunosuppressive activity. Nevertheless, little is known about the systemic levels of these soluble co-inhibitory immune checkpoints in patients with various subtypes of basal cell carcinoma (BCC), which is the most invasive and treatment-resistant type of this most commonly-occurring malignancy. In the current study, we have measured the systemic concentrations of five prominent co-inhibitory immune checkpoints, namely CTLA-4, LAG-3, PD-1/PD-L1 and TIM-3, as well as those of C-reactive protein (CRP) and vitamin D (VD), in a cohort of patients (n = 40) with BCC, relative to those of a group of control participants, using the combination of multiplex bead array, laser nephelometry and ELISA technologies, respectively. The median systemic concentrations of CRP and VD were comparable between the two groups; however, those of all five immune checkpoints were significantly elevated (P = 0.0184 - P = < 0.00001), with those of CTLA-4 and PD-1 being highly correlated (r = 0.87; P < 0.00001). This seemingly novel finding not only identifies the existence of significant systemic immunosuppression in BCC, but also underscores the therapeutic promise of immune checkpoint targeted therapy, as well as the potential of these proteins to serve as prognostic/predictive biomarkers in BCC.     

Geranylgeranoic acid,a bioactive and endogenous fatty acid in mammals: a review

Geranylgeranoic acid (GGA) was first reported in 1983 as one of the mevalonic acid metabolites, but its biological significance was not studied for a long time. Our research on the antitumor effects of retinoids led us to GGA, one of the acyclic retinoids that induce cell death in human hepatoma-derived cell lines. We were able to demonstrate the presence of endogenous GGA in various tissues of male rats, including the liver, testis, and cerebrum, by LC-MS/MS. Furthermore, the biosynthesis of GGA from mevalonic acid in mammals including humans was confirmed by isotopomer spectral analysis using ¹³C-labeled mevalonolactone and cultured hepatoma cells, and the involvement of hepatic monoamine oxidase B in the biosynthesis of GGA was also demonstrated. The biological activity of GGA was analyzed from the retinoid (differentiation induction) and nonretinoid (cell death induction) aspects, and in particular, the nonretinoid mechanism by which GGA induces cell death in hepatoma cells was found to involve pyroptosis via ER stress responses initiated by TLR4 signaling. In addition to these effects of GGA, we also describe the in vivo effects of GGA on reproduction. In this review, based mainly on our published papers, we have shown that hepatic monoamine oxidase B is involved in the biosynthesis of GGA and that GGA induces cell death in human hepatoma-derived cell lines by noncanonical pyroptosis, one of the mechanisms of sterile inflammatory cell death.     

Under time pressure,the exogenous modulation of saccade plans is ubiquitous,intricate, and lawful

The choice of where to look next is determined by both exogenous (bottom-up) and endogenous (top-down) factors, but details of their interaction and distinct contributions to target selection have remained elusive. Recent experiments with urgent choice tasks, in which stimuli are evaluated while motor plans are already advancing, have greatly clarified these contributions. Specifically, exogenous modulations associated with stimulus detection act rapidly and briefly (∼25 ms) to automatically halt and/or boost ongoing motor plans as per spatial congruence rules. These stereotypical modulations explain, in quantitative detail, characteristic features of many saccadic tasks (e.g. antisaccade, countermanding, saccadic-inhibition, gap, and double-step). Thus, the same low-level visuomotor interactions contribute to diverse oculomotor phenomena traditionally attributed to different neural mechanisms.     

E3 ligase RCHY1 negatively regulates HDAC2

HDAC2, one of the class I histone deacetylase regulates epigenetic landscape through histone modification. Because HDAC2 is overexpressed in many cancers, cancer therapeutics against HDAC2 have been developed. Here we show novel mechanism of HDAC2 regulation by E3 ligase RCHY1. We found inverse correlation RCHY1 and HDAC2 levels in tumor tissue from six independent dataset using meta-analysis. Ectopic expression of RCHY1 decreased the level of HDAC2 from cancer cells including p53 wildtype, mutant and null cells. In addition, HDAC2 was increased by RCHY1 knockdown. RCHY1 directly interacts with HDAC2. Ectopic expression of wild type but not RING mutant RCHY1 increased HDAC2 levels. These data provide an evidence that RCHY1 negatively regulates HDAC2.     

Hormone-sensitive lipase is localized at synapses and is necessary for normal memory functioning in mice

Hormone-sensitive lipase (HSL) is mainly present in adipose tissue where it hydrolyzes diacylglycerol. Although expression of HSL has also been reported in the brain, its presence in different cellular compartments is uncertain, and its role in regulating brain lipid metabolism remains hitherto unexplored. We hypothesized that HSL might play a role in regulating the availability of bioactive lipids necessary for neuronal function and therefore investigated whether dampening HSL activity could lead to brain dysfunction. In mice, we found HSL protein and enzymatic activity throughout the brain, localized within neurons and enriched in synapses. HSL-null mice were then analyzed using a battery of behavioral tests. Relative to wild-type littermates, HSL-null mice showed impaired short-term and long-term memory, yet preserved exploratory behaviors. Molecular analysis of the cortex and hippocampus showed increased expression of genes involved in glucose utilization in the hippocampus, but not cortex, of HSL-null mice compared with controls. Furthermore, lipidomics analyses indicated an impact of HSL deletion on the profile of bioactive lipids, including a decrease in endocannabinoids and eicosanoids that are known to modulate neuronal activity, cerebral blood flow, and inflammation processes. Accordingly, mild increases in the expression of proinflammatory cytokines in HSL mice compared with littermates were suggestive of low-grade inflammation. We conclude that HSL has a homeostatic role in maintaining pools of lipids required for normal brain function. It remains to be tested, however, whether the recruitment of HSL for the synthesis of these lipids occurs during increased neuronal activity or whether HSL participates in neuroinflammatory responses.     

HDL Isolated by Immunoaffinity,Ultracentrifugation, or Precipitation is Compositionally and Functionally Distinct

The HDL proteome has been widely recognized as an important mediator of HDL function. While a variety of HDL isolation methods exist, their impact on the HDL proteome and its associated function remain largely unknown. Here, we compared three of the most common methods for HDL isolation, namely immunoaffinity (IA), density gradient ultracentrifugation (UC), and dextran-sulfate precipitation (DS), in terms of their effects on the HDL proteome and associated functionalities. We used state-of-the-art mass spectrometry to identify 171 proteins across all three isolation methods. IA-HDL contained higher levels of paraoxonase 1, apoB, clusterin, vitronectin, and fibronectin, while UC-HDL had higher levels of apoA2, apoC3, and α-1-antytrypsin. DS-HDL was enriched with apoA4 and complement proteins, while the apoA2 content was very low. Importantly, size-exclusion chromatography analysis showed that IA-HDL isolates contained subspecies in the size range above 12 nm, which were entirely absent in UC-HDL and DS-HDL isolates. Analysis of these subspecies indicated that they primarily consisted of apoA1, IGκC, apoC1, and clusterin. Functional analysis revealed that paraoxonase 1 activity was almost completely lost in IA-HDL, despite high paraoxonase content. We observed that the elution conditions, using 3M thiocyanate, during IA resulted in an almost complete loss of paraoxonase 1 activity. Notably, the cholesterol efflux capacity of UC-HDL and DS-HDL was significantly higher compared to IA-HDL. Together, our data clearly demonstrate that the isolation procedure has a substantial impact on the composition, subclass distribution, and functionality of HDL. In summary, our data show that the isolation procedure has a significant impact on the composition, subclass distribution and functionality of HDL. Our data can be helpful in the comparison, replication and analysis of proteomic datasets of HDL.     

SP3-Enabled Rapid and High Coverage Chemoproteomic Identification of Cell-State–Dependent Redox-Sensitive Cysteines

Proteinaceous cysteine residues act as privileged sensors of oxidative stress. As reactive oxygen and nitrogen species have been implicated in numerous pathophysiological processes, deciphering which cysteines are sensitive to oxidative modification and the specific nature of these modifications is essential to understanding protein and cellular function in health and disease. While established mass spectrometry-based proteomic platforms have improved our understanding of the redox proteome, the widespread adoption of these methods is often hindered by complex sample preparation workflows, prohibitive cost of isotopic labeling reagents, and requirements for custom data analysis workflows. Here, we present the SP3-Rox redox proteomics method that combines tailored low cost isotopically labeled capture reagents with SP3 sample cleanup to achieve high throughput and high coverage proteome-wide identification of redox-sensitive cysteines. By implementing a customized workflow in the free FragPipe computational pipeline, we achieve accurate MS1-based quantitation, including for peptides containing multiple cysteine residues. Application of the SP3-Rox method to cellular proteomes identified cysteines sensitive to the oxidative stressor GSNO and cysteine oxidation state changes that occur during T cell activation.     

Semaphorin 3A potentiates the profibrotic effects of transforming growth factor-β1 in the cornea

Corneal scarring is a major cause of blindness worldwide with few effective therapeutic options. Finding a treatment would be of tremendous public health benefit, but requires a thorough understanding of the complex interactions that underlie this phenomenon. Here, we tested the hypothesis that the large increase in expression of Semaphorin 3A (SEMA3A) in corneal wounds contributes to the development of stromal fibrosis. We first verified this increased expression in vivo, in a cat model of photorefractive keratectomy-induced corneal wounding. We then examined the impact of adding exogenous SEMA3A to cultured corneal fibroblasts, and assessed how this affected the ability of transforming growth factor-beta1 (TGF-β1) to induce their differentiation into myofibroblasts. Finally, we examined how siRNA knockdown of endogenous SEMA3A affected these same phenomena. We found exogenous SEMA3A to significantly potentiate TGF-β1’s profibrotic effects, with only a minimal contribution from cell-intrinsic SEMA3A. Our results suggest a previously unrecognized interaction between SEMA3A and TGF-β1 in the wounded cornea, and a possible contribution of SEMA3A to the regulation of tissue fibrosis and remodeling in this transparent organ.     

Association Between a Low-Carbohydrate Diet,Glycemic Control,and Quality of Life in Australian Adults Living With Type 1 Diabetes: A Pilot Study

ObjectiveTo examine if there is an association between a low-carbohydrate diet (LCD), glycemic control, and quality of life (QoL) in Australian adults with type 1 diabetes.MethodsThis single-group, pre-post, mixed methods (quantitative and qualitative) study was conducted in an outpatient tertiary hospital. Eligible participants were those aged ≥18 years, with type 1 diabetes for ≥1 year, and using multiple daily insulin injections. Participants followed a 12-week individualized LCD (<100 g/d). Daily glucose levels were monitored using a continuous glucose monitor. Glycated hemoglobin (HbA1c) and QoL were measured preintervention and postintervention. A post-hoc exploratory regression analysis determined whether changes in carbohydrate intake was associated with changes in HbA1c and QoL. Qualitative data collected postintervention explored participants’ perceptions relating to a LCD, glycemic control, and QoL.ResultsParticipants (n = 22) completed the 12-week LCD intervention. An LCD provided a statistically, significant improvement in HbA1c 0.83% (95% CI 0.32%-1.33%), P = .003 but did not impact QoL: estimated change 1.14 units (95% CI: ?5.34 to 7.61); P = .72. The post-hoc exploratory regression analysis showed that participants with poorer baseline glycemic control were more likely to respond to an LCD resulting in significant reductions in HbA1c. Participant perceptions relating to the study variables were mixed.ConclusionsAn LCD (<100 g/d) is a potentially effective and safe strategy to improve glycemic control without negatively effecting QoL in Australian adults with type 1 diabetes.     

A Pilot Study of Youth With Type 1 Diabetes Initiating Use of a Hybrid Closed-Loop System While Receiving a Behavioral Economics Intervention

ObjectiveMany youth do not use the hybrid closed-loop system for type 1 diabetes effectively. This study evaluated the impact of financial incentives for diabetes-related tasks on use of the 670G hybrid closed-loop system and on glycemia.MethodsAt auto mode initiation and for 16 weeks thereafter, participants received a flat rate for wearing and calibrating the sensor ($1/day), administering at least 3 mealtime insulin boluses per day ($1/day), and uploading ($5/week). Weekly bonuses were given for maintaining at least 70% of the time in auto mode, which were increased for persistent auto mode use from $3/week to a maximum of $13/week. If a participant failed to maintain auto mode for a week, the rewards were reset to baseline. Data from 17 participants aged 15.9 years ± 2.5 years (baseline hemoglobin A1c [HbA1c] 8.6% ± 1.1%) were collected at 6, 12, and 16 weeks. The reinforcers were withdrawn at 16 weeks, with a follow-up assessment at 24 weeks.ResultsWith reinforcers, the participants administered an average of at least 3 mealtime insulin boluses per day and wore the sensor over 70% of the time. However, auto mode use waned. HbA1c levels decreased by 0.5% after 6 weeks, and this improvement was maintained at 12 and 16 weeks (P < .05). Upon withdrawal of reinforcers, HbA1c levels increased back to baseline at 24 weeks.ConclusionCompensation for diabetes-related tasks was associated with lower HbA1c levels, consistent administration of mealtime insulin boluses, and sustained sensor use. These results support the potential of financial rewards for improving outcomes in youth with type 1 diabetes.     

Type III collagen is a key regulator of the collagen fibrillar structure and biomechanics of articular cartilage and meniscus

Despite the fact that type III collagen is the second most abundant collagen type in the body, its contribution to the physiologic maintenance and repair of skeletal tissues remains poorly understood. This study queried the role of type III collagen in the structure and biomechanical functions of two structurally distinctive tissues in the knee joint, type II collagen-rich articular cartilage and type I collagen-dominated meniscus. Integrating outcomes from atomic force microscopy-based nanomechanical tests, collagen fibril nanostructural analysis, collagen cross-link analysis and histology, we elucidated the impact of type III collagen haplodeficiency on the morphology, nanostructure and biomechanical properties of articular cartilage and meniscus in Col3a1^+/− mice. Reduction of type III collagen leads to increased heterogeneity and mean thickness of collagen fibril diameter, as well as reduced modulus in both tissues, and these effects became more pronounced with skeletal maturation. These data suggest a crucial role of type III collagen in mediating fibril assembly and biomechanical functions of both articular cartilage and meniscus during post-natal growth. In articular cartilage, type III collagen has a marked contribution to the micromechanics of the pericellular matrix, indicating a potential role in mediating the early stage of type II collagen fibrillogenesis and chondrocyte mechanotransduction. In both tissues, reduction of type III collagen leads to decrease in tissue modulus despite the increase in collagen cross-linking. This suggests that the disruption of matrix structure due to type III collagen deficiency outweighs the stiffening of collagen fibrils by increased cross-linking, leading to a net negative impact on tissue modulus. Collectively, this study is the first to highlight the crucial structural role of type III collagen in both articular cartilage and meniscus extracellular matrices. We expect these results to expand our understanding of type III collagen across various tissue types, and to uncover critical molecular components of the microniche for regenerative strategies targeting articular cartilage and meniscus repair.     

β-Carotene enhances the expression of inflammation-related genes and histone H3 K9 acetylation,K4 dimethylation,and K36 trimethylation around these genes in juvenile macrophage-like THP-1 cells

β-Carotene is converted into vitamin A in the body and can remove reactive oxygen species. However, it is still unclear whether β-carotene alters the expression levels of inflammation-related genes in macrophages and how this is regulated. In the present study, we investigated whether the administration of β-carotene under hyperglycemic conditions altered the expression level of inflammation-related genes and whether any observed differences were associated with changes in histone modifications in juvenile macrophage-like THP-1 cells. THP-1 cells (from a human monocytic leukemia cell line) were cultured in low glucose (5 mM), high glucose (25 mM), or high glucose (25 mM) + β-carotene (5 μM) media for 1 day, and mRNA expression levels of genes related to oxidative stress and inflammation, and histone modifications were determined by mRNA microarray and qRT-PCR analyses, and chromatin immunoprecipitation assays, respectively. The expression of inflammation-related genes, such as IL31RA, CD38, and NCF1B, and inflammation-associated signaling pathway genes, such as ITGAL, PRAM1, and CSF3R, were upregulated by β-carotene under high-glucose conditions. Under these conditions, histone H3 lysine 4 (K4) demethylation, H3K36 trimethylation, and H3K9 acetylation around the CD38, NCF1B, and ITGAL genes were higher in β-carotene-treated cells than in untreated cells. Treatment of juvenile macrophage-like THP-1 cells with β-carotene under these high glucose conditions induced the expression of inflammation-related genes, K9 acetylation, and K4 di- and K36 trimethylation of histone H3 around these genes.     

Effects of 1α,25-dihydroxyvitamin D3 and tacalcitol on cell signaling and anchorage-independent growth in T98G and U251 glioblastoma cells

The active hormonal form of vitamin D, 1α,25-dihydroxyvitamin D₃, is reported to have 1000s of biological targets. The growth-suppressive properties of 1α,25-dihydroxyvitamin D₃ and its synthetic analogs have attracted interest for the development of treatment and/or prevention of cancer. We examined effects of 1α,25-dihydroxyvitamin D₃ and the vitamin D analog tacalcitol on signaling pathways and anchorage-independent growth in T98G and U251 glioblastoma cells. Assay of signaling proteins important for cellular growth indicated suppression of p70-S6 kinase levels by 1α,25-dihydroxyvitamin D₃ and tacalcitol in T98G cells, whereas the levels of PLCγ, a target for phospholipid signaling, was slightly increased.Activation of STAT3, an important regulator of malignancy, was suppressed by 1α,25-dihydroxyvitamin D₃ and tacalcitol in T98G and U251 cells. However, despite the close structural similarity of these compounds, suppression was stronger by tacalcitol (1α,24-dihydroxyvitamin D₃), indicating that even minor modifications of a vitamin D analog can impact its effects on signaling. Experiments using soft agar colony formation assay in T98G and U251 cells revealed significant suppression by 1α,25-dihydroxyvitamin D₃ and tacalcitol on anchorage-independent growth, a property for cancer invasion and metastasis known to correlate with tumorigenicity. These findings indicate that vitamin D and its analogs may be able to counteract the oncogenic transformation, invasion and metastatic potential of glioblastoma and prompt further study of these compounds in the development of improved therapy for brain cancer.