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- Vitamin D regulating TGF-β induced epithelial-mesenchymal transition. [JOURNAL ARTICLE]
- Respir Res 2014 Nov 21; 15(1):146.
BackgroundSubepithelial fibrosis is a characteristic hallmark of airway remodeling in asthma. A critical regulator of fibrosis, transforming growth factor β (TGF-β), can induce airway remodeling in epithelial cells through induction of epithelial-mesenchymal transition (EMT). Vitamin D has immunomodulatory functions, however, its effect on controlling subepithelial fibrosis is not known.MethodsHuman bronchial epithelial cells (BEAS-2B) were exposed to calcitriol followed by stimulation with TGF-β1 or TGF-β2. The protein expression and mRNA transcripts for E-cadherin, Snail, vimentin, and N-cadherin were analyzed by Western blot and qPCR. An invasion assay and scratch wound assay were performed to identify the migratory properties of the cells following treatments.ResultsTGF-β1 decreased E-cadherin expression and increased protein expression and mRNA transcripts of Snail, vimentin, and N-cadherin together with increased cell invasion and migration. TGF-β2 elicited migratory response similar to TGF-β1 but induced the expression of EMT markers differently from that by TGF-β1. Calcitriol attenuated TGF-β1- and TGF-β2-induced cell motility. Also, calcitriol inhibited the expression of EMT markers in TGF-β1-treated epithelial cells with less effect on TGF-β2.ConclusionsThese data suggest that calcitriol inhibits both migration and invasion induced by TGF-β1 and TGF-β2 in human airway epithelial cells. However, the regulatory effect of vitamin D in epithelial-mesenchymal transition was more effective to TGF-β1-induced changes. Thus, calcitriol could be a potential therapeutic agent in the prevention and management of subepithelial fibrosis and airway remodeling.
- An Update on Topical Therapies for Mild-Moderate Psoriasis. [REVIEW]
- Dermatol Clin 2015; 33(1):73-77.
Topical therapies are the mainstream treatment of psoriasis because most patients have mild disease. First-line treatments are vitamin D derivatives and corticosteroids. These treatments are usually given in combination schedules. For topical treatments the selection of the most appropriate vehicle is of major importance, thus improving adherence to the treatment, which frequently is impaired by the complexities of topical therapeutic choices. Evidence for efficacy and safety of topical treatments is readily available for vitamin D treatments and short-term treatment with corticosteroids. However, the scientific evidence for longer-term treatments is limited. Multiple new small molecules are in various stages of development and are reviewed.
- Coexistence of the POEMS syndrome with hepatitis B: a rare case report. [JOURNAL ARTICLE]
- Wien Klin Wochenschr 2014 Nov 21.
POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) is a rare multisystemic disease of unknown pathogenesis. Proinflammatory and proangiogenic cytokines play important roles in its pathogenesis. POEMS syndrome is a rare cause of ascites. Until now, the coexistence of POEMS syndrome and hepatitis B has not been reported. In this case report, we present a 48-year-old male patient who presented with malaise, fatigue, diarrhea, and abdominal swelling. Organomegaly, endocrinopathy, ascites, skin changes, and polyneuropathy were identified, and we arrived at a diagnosis of POEMS syndrome. The patient was administered methylprednisolone 64 mg/day, lamivudine 100 mg/day, calcium 1.5 g/day, and calcitriol 0.5 µg/day. The patient's clinical manifestations had moderately resolved at the follow-up visits. At the end of 6 months of follow-up, his ascites was minimally reduced, and his neurologic manifestations had not lessened. The present case shows that accurate diagnosis is required for the management of patients with coexisting POEMS syndrome and hepatitis B.
- Inhibition of class I HDACs abrogates the dominant effect of MLL-AF4 by activation of wild-type MLL. [Journal Article]
- Oncogenesis 2014.:e127.
The ALOX5 gene encodes 5-lipoxygenase (5-LO), a key enzyme of inflammatory reactions, which is transcriptionally activated by trichostatin A (TSA). Physiologically, 5-LO expression is induced by calcitriol and/or transforming growth factor-β. Regulation of 5-LO mRNA involves promoter activation and elongation control within the 3'-portion of the ALOX5 gene. Here we focused on the ALOX5 promoter region. Transcriptional initiation was associated with an increase in histone H3 lysine 4 trimethylation in a TSA-inducible manner. Therefore, we investigated the effects of the MLL (mixed lineage leukemia) protein and its derivatives, MLL-AF4 and AF4-MLL, respectively. MLL-AF4 was able to enhance ALOX5 promoter activity by 47-fold, which was further stimulated when either vitamin D receptor and retinoid X receptor or SMAD3/SMAD4 were co-transfected. In addition, we investigated several histone deacetylase inhibitors (HDACi) in combination with gene knockdown experiments (HDAC1-3, MLL). We were able to demonstrate that a combined inhibition of HDAC1-3 induces ALOX5 promoter activity in an MLL-dependent manner. Surprisingly, a constitutive activation of ALOX5 by MLL-AF4 was inhibited by class I HDAC inhibitors, by relieving inhibitory functions deriving from MLL.Conversely, a knockdown of MLL increased the effects mediated by MLL-AF4. Thus, HDACi treatment seems to switch 'inactive MLL' into 'active MLL' and overwrites the dominant functions deriving from MLL-AF4.
- Vitamin D and colon cancer. [Journal Article, Review]
- World J Gastrointest Oncol 2014 Nov 15; 6(11):430-7.
Calcitriol, 1α, 25-dihydroxyvitamin D3 (1,25 (OH)2D3), the most active form of vitamin D, is a pleotropic hormone with a wide range of biological activities. Due to its ability to regulate calcium and phosphate metabolism, 1,25D3 plays a major role in bone health. In addition, 1,25D3 binds to the vitamin D receptor and thereby regulates the expression of a number of genes which control growth, differentiation and survival of cancer cells. In agreement, the levels of vitamin D3 appear to be an essential determinant for the development and progression of colon cancer and supplementation with vitamin D3 is effective in suppressing intestinal tumorigenesis in animal models. Vitamin D3 has been estimated to lower the incidence of colorectal cancer by 50%, which is consistent with the inverse correlation between dietary vitamin D3 intake or sunlight exposure and human colorectal cancer. Several studies confirmed that increasing vitamin D3 lowers colon cancer incidence, reduces polyp recurrence, and that sufficient levels of vitamin D3 are associated with better overall survival of colon cancer patients. Vitamin D regulates the homeostasis of intestinal epithelium by modulating the oncogenic Wnt signaling pathway and by inhibiting tumor-promoting inflammation. Both activities contribute to the ability of 1,25D3 to prevent the development and progression of colon cancer.
- A Few Follow-up Questions to a Recent Calcitriol and Sepsis Study. [Journal Article]
- Am J Respir Crit Care Med 2014 Nov 15; 190(10):1194.
- Synthesis and Biological Activity of Two C-7 Methyl Analogues of Vitamin D. [JOURNAL ARTICLE]
- J Org Chem 2014 Nov 14.
Two novel vitamin D analogues of the hormone 1alpha,25-(OH)2D3 modified at C-7, namely, 7-methyl-1alpha,25-(OH)2D3 (12) and 7-methyl-1alpha,25-(OH)2-19-nor-D3 (26) were synthesized and biologically evaluated to gain further insights into the structure-function relationships of vitamin D. Key steps in the synthesis of 12 include the functionalization at C-7 by an efficient regioselective hydrostannylation of an allene precursor, and the construction of the triene framework by a palladium-catalyzed intramolecular cyclization-Suzuki-Miyaura coupling cascade. Since the calcitriol analogue 12 was prone to conversion into its previtamin D form by thermal equilibration, the corresponding 19-nor-compound 26 was also synthesized. The diene moiety of compound 26 was constructed by a modified Julia coupling. UV data as well as X-ray analysis indicate that introduction of the methyl group at C-7 results in a significant deviation from planarity of the 5,7-diene moiety. The new vitamin D analogues 12 and 26 retained good VDR binding ability.
- A randomized control trial to assess the impact of vitamin D supplementation compared to placebo on vascular stiffness in chronic kidney disease patients. [Journal Article]
- BMC Cardiovasc Disord 2014.:156.
Vitamin D deficiency is associated with cardiovascular (CV) risk in multiple populations, including those with chronic kidney disease (CKD). The active form of the hormone (1,25 OH2D3) binds to receptors in multiple organs. CKD patients are deficient in both 25 Vitamin D and 1,25 OH2D3. Clinical trial data demonstrating the benefits of vitamin D formulations are limited, and fail to show significant benefits on CV outcomes, and have compared different compounds, in various populations, and focused on a variety of outcomes. A understanding of the mechanism by which different vitamin D compounds confer CV protection in CKD is important for the design of future studies.This 3 arm randomized prospective double-blinded placebo-controlled study examining the impact of calcitriol (1,25 OH2D3) and 25-hydroxyvitamin D3 supplementation compared to placebo on vascular stiffness, as measured by pulse wave velocity (PWV). Patients are enrolled from 2 tertiary care institutions if they meet inclusion criteria (stable estimated glomerular filtration rate (eGFR) between 15-45ml/min, <±5ml/min change in previous 6 months), on stable doses of renin-angiotensin aldosterone system blockade. For those already receiving vitamin D therapies, a 3 month washout period before randomization is mandatory. Treatment duration is 6 months; medications are given thrice weekly in fixed doses. The primary outcome measure is Vascular stiffness, measured non-invasively by pulse wave velocity (PWV). Other measurements include BP, kidney function and serial blood levels of biomarkers. The primary analysis will compare any vitamin D therapy versus placebo for the primary outcome defined as the change of PWV from baseline to 6 months. Analysis of covariance will be used to detect differences between vitamin D preparations in the magnitude of reduction in PWV.This study is novel in that we are using a robust study design in CKD patients (not on dialysis) comparing placebo to different forms of vitamin D supplementation in fixed doses, irrespective of baseline values. We hope to demonstrate the biological mechanistic effect of vitamin D supplementation on vascular function in order for this information to be used in designing larger randomized controlled trials.Current Controlled Trials NCT01247311. Date of Registration: November 12, 2010.
- Comparison of Paricalcitol With Maxacalcitol Injection in Japanese Hemodialysis Patients With Secondary Hyperparathyroidism. [JOURNAL ARTICLE]
- Ther Apher Dial 2014 Nov 3.
Secondary hyperparathyroidism (SHPT) is one of the major complications of chronic kidney disease (CKD) and is associated with elevated serum intact parathyroid hormone (iPTH). Calcitriol, a non-selective vitamin D receptor agonist (VDRA) that suppresses iPTH is used for SHPT treatment, but its use is frequently complicated by hypercalcemia. Paricalcitol, a selective VDRA, demonstrated efficacy in iPTH suppression compared to maxacalcitol in a Phase 2 study (M11-609) in Japanese subjects. The current larger Phase 3 study (M11-517), evaluated the efficacy of intravenous paricalcitol injection compared to intravenous maxacalcitol injection with respect to iPTH and calcium control using a non-inferiority primary endpoint. In this double-blind, double-dummy, parallel-group study, eligible Japanese CKD subjects with SHPT on hemodialysis were randomized 1:1 to receive intravenous paricalcitol or intravenous maxacalcitol injections for 12 weeks. Dynamic allocation of subjects on the basis of screening iPTH levels was used to ensure equal distribution of subjects with iPTH <500 pg/mL and ≥500 pg/mL into the two treatment groups. 255 subjects were randomized to receive paricalcitol (N = 127) or maxacalcitol (N = 128). Primary efficacy analysis indicated that 27.7% in the paricalcitol group vs. 30.5% in the maxacalcitol group (95% CI -14.34% to 8.79%, P = 0.353) achieved target iPTH in the last 3 weeks without hypercalcemia during treatment, failing to achieve the non-inferiority margin of -5% that was set based upon agreement with the PMDA. Both intravenous paricalcitol and maxacalcitol were effective in reducing iPTH and provided similar safety profiles; however, non-inferiority for paricalcitol vs. maxacalcitol was not demonstrated.
- Hypoparathyroidism after Roux-en-Y gastric bypass - a challenge for clinical management: a case report. [Journal Article]
- J Med Case Rep 2014; 8(1):357.
In this report, we describe challenges we encountered in the clinical management of a patient with hypoparathyroidism who had previously undergone a bariatric procedure.We report the case of a 38-year-old Caucasian woman who had undergone a Roux-en-Y gastric bypass procedure for treatment of obesity. She also had a past history of right lobectomy to treat a benign thyroid nodule. Another thyroid nodule was diagnosed after her bariatric surgery, so a new thyroid surgery was performed. Permanent hypoparathyroidism occurred after the second thyroid surgery. A Roux-en-Y gastric bypass resulted in important weight loss, but the preferential site of calcium absorption was bypassed. The lack of endogenous parathyroid hormone secretion due to post-surgical hypoparathyroidism abolished the physiological mechanism that compensates the reduced calcium absorption, which was a challenge for us to overcome. In this report, we describe our clinical therapeutic choices to maintain normocalcemia and normophosphatemia in this patient. Higher doses of exogenous calcium citrate, calcitriol and cholecalciferol were used, but hypocalcemia was still present. To improve vitamin D absorption with resultant improvement of calcium homeostasis, we speculated that adding pancrelipase to meals would increase lipid absorption and possibly fat-soluble vitamins, including vitamin D. Only after the addition of pancrelipase did the patient improve without weight regain according to clinical and laboratory assessments.The use of exogenous pancreatic enzymes improved calcium homeostasis in this bariatric patient. The role of these enzymes on vitamin D absorption and subsequent rise in calcium levels in hypoparathyroid patients who undergo bariatric procedures need further investigation.