Source: UNIV OF WISCONSIN submitted to
VITAMIN RESEARCH
Sponsoring Institution
State Agricultural Experiment Station
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0209742
Grant No.
(N/A)
Project No.
WIS01160
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2006
Project End Date
Sep 30, 2011
Grant Year
(N/A)
Project Director
Clagett-Dame, M.
Recipient Organization
UNIV OF WISCONSIN
21 N PARK ST STE 6401
MADISON,WI 53715-1218
Performing Department
BIOCHEMISTRY
Non Technical Summary
The reproductive efficiency and health of animals, including humans, is clearly influenced by nutritional status. It is becoming abundantly clear that rather than striving only to prevent overt nutrient deficiency, that we need to begin to develop an understanding of "optimal" levels of a given nutrient to promote health. Much of the work in the first part of this project is directed at understanding when and where during development vitamin A is needed, and exactly how it functions. A detailed understanding of the physiological and molecular processes for which vitamins are needed is essential not only for optimizing human health, but also for determining how vitamin derivatives might be used in the treatment of human disease. For example, vitamin A compounds have shown promise in the prevention and treatment of cancer, as well as in the treatment of acne. However, the toxicity of many retinoids limits their use. Additional studies are directed at understanding how vitamin A derivatives produce their positive effects, and at developing new, safe and effective compounds with reduced toxicity. Similar potential exists for the use of vitamin D analogs in a number of diseases such as obesity, but the side effect, hypercalcemia, has been a major limitation to the advancement of these efforts. The next step is to determine whether vitamin D analogs can be identified that when given to young animals can inhibit the development of adipocytes without altering serum calcium levels.
Animal Health Component
(N/A)
Research Effort Categories
Basic
80%
Applied
20%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7023840101060%
7023840115020%
7023840118020%
Goals / Objectives
The overall focus of this work is the study of the fat-soluble vitamins A and D. The specific objectives of this work are: 1) to determine how vitamin A supports embryonic development with particular emphasis on neural development; 2) to elucidate how analogs of the retinoid, 4-hydroxyphenylretinamide (4-HPR) induce the death of breast cancer cells; 3) to determine how vitamin D analogs inhibit the differentiation of adipocytes, and 4) to determine how synthetic compounds related to vitamins A and D can be used in the treatment of human disease.
Project Methods
Project 1. Both nutritional and genetic approaches are being used to determine how and when vitamin A is needed for developing embryos. Our laboratory has developed a unique nutritional method that enables study of vitamin A function both in early and late embryonic processes. Using this model, we have shown that vitamin A plays a critical early role in patterning the heart, hindbrain and axial skeleton. Recent efforts have been directed at the use of this model to study later developmental process (those occurring after embryonic day 10.5) that are under the control of vitamin A and its metabolites. Using this model, we can show that 100% of embryos provided with limiting amounts of the vitamin A metabolite, all-trans retinoic acid (atRA), starting at approximately the 12 to 14 somite stage go on to develop profound morphological abnormalities. We are now using this model to explore the molecular mechanisms that are disrupted in late embryonic vitamin A-deficiency. Using subtractive hybridization, we also recently identified 8 novel atRA responsive genes in a cell line of neural origin, and have begun to examine the function of two of these using knockdown approaches both in cell culture and in vivo. Using siRNA technology, we have shown that one of these genes (RAINB1) plays an essential role in neurite outgrowth. Studies of mice null or hypomorphic for these genes are currently underway. Project 2. Cellular and in vivo approaches are being used to address how 4-HPR analogs exert their affects on cancer cells, and to identify the most promising analog for future studies. In collaboration with our colleagues at the OSU, we have found that the carbon-linked 4-HPR analog (4-HBR) does not need to be hydrolyzed back to atRA to function in culture or in vivo. Studies of the efficacy 4-HBR in chemotherapy of DMBA-induced mammary tumors in the rat show that the non-hydrolysable analog is equally effective in reducing tumor size and number, and does so without reducing blood retinol levels, an undesirable side affect associated with the use of the parent compound, 4-HPR. Studies of the activity of these analogs in breast cancer cells show that although these compounds can bind and transactivate RARs, this is not required for these analogs to induce cell death. Project 3. Using the preadipocyte cell line, 3T3-L1, we have begun to probe the mechanism of action of vitamin D compounds in inhibiting fat cell differentiation. We have found at least one analog that is approximately two orders of magnitude more potent than the parent hormone in preventing adipocyte differentiation. Project 4. Additional studies in the lab are directed at developing improved vitamin analogs for the treatment of disease. One example is the use of retinoids for the treatment of acne. A major limitation to current oral therapy is teratogenic liability. As a potential improvement, we are studying sterically hindered vitamin A analogs. Using the Rhino mouse as a model, the ability of compounds to produce a reduction in comedone size is being studied. Measures of toxicity are also being examined to assess whether these compounds offer any therapeutic advantage.

Progress 10/01/06 to 09/30/11

Outputs
OUTPUTS: The overall focus of this work is the study of the fat-soluble vitamins A and D. Ongoing work in three project areas is described below. Project 1. Both nutritional and genetic approaches are being used to determine how vitamin A functions in developing embryos, neonates and adults. Our laboratory has developed animal models to study vitamin A function in both early and late embryonic processes, as well as during postnatal life. We have shown that vitamin A is required for the initiation of meiosis in both the female and male gonad. Additionally, we identified several retinoic acid responsive genes that are expressed in the nervous system of developing embryos and in the adult brain. One of these, neuron navigator 2 (Nav2 or retinoic acid-induced in neuroblastoma, RAINB1), plays an essential role in neurite outgrowth, and in the development of the cranial nerves, eye, and brain. Project 2. Cellular and in vivo approaches are being used to address how the 4-HPR analog, 4-hydroxybenzylretinone (4-HBR), exerts its antitumor effects. In collaboration with our colleagues at the OSU, we have shown that the carbon-linked 4-HPR analog, 4-hydroxybenzylretinone (4-HBR), does not need to be hydrolyzed back to atRA to function in culture or in vivo. Mechanistic microarray studies are underway to determine how these compounds work in cultured breast cancer cells and mammary tumors. Project 3. Additional studies in the lab are directed at developing improved vitamin analogs for the treatment of acne and other disease states. Using the Rhino mouse as a model, we have identified a unique subset of vitamin D analogs that induce comedolysis. Studies are underway to determine how vitamin D compounds act to produce these effects. PARTICIPANTS: Jamie Ahrens (Senior research specialist), Elizabeth McNeill (Research associate), Danielle Knutsion (Research associate), Allyson Anding (Research assistant), Melissa Rohrer (Research associate), Mark Marzinke (Research assistant), Nirca Nieves (Research associate), Jim James (Associate research specialist), Mariana Bormann (Associate research specialist) TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The reproductive efficiency and health of animals, including humans, is clearly influenced by nutritional status. Rather than striving only to prevent overt nutrient deficiency, we need to begin to develop an understanding of "optimal" levels of a given nutrient to promote health. A detailed understanding of the physiological and molecular processes for which vitamins are needed is essential not only for optimizing human health, but also for determining how vitamin derivatives might be used in the treatment of human disease. For example, vitamin A compounds have shown promise in the prevention and treatment of cancer, as well as in the treatment of acne. However, the toxicity of many retinoids limits their use. Similar potential exists for the use of vitamin D analogs in a number of diseases, but the side effect, hypercalcemia, has been a major limitation to the advancement of these efforts. Thus, studies of new vitamin A analogs and non-calcemic vitamin D analogs may offer new approaches to the treatment of several disease states, including acne and cancer. Numerous patents that have issued or have been filed through the Wisconsin Alumini Research Foundation have arisen from these studies.

Publications

  • Nieves, N.J., Ahrens, J.M., Plum, L.A., DeLuca, H.F., Clagett-Dame, M., 2010. Identification of a unique subset of 2-methylene-19-nor analogs of vitamin D with comedolytic activity in the rhino mouse. J Invest Dermatol 130, 2359-2367.
  • McNeill, E.M., Roos, K.P., Moechars, D., Clagett-Dame, M., 2010. Nav2 is necessary for cranial nerve development and blood pressure regulation. Neural Dev 5, 6. Marzinke, M.A., Henderson, E.M., Yang, K.S., See, A.W., Knutson, D.C., Clagett-Dame, M., 2010. Calmin expression in embryos and the adult brain, and its regulation by all-trans retinoic acid. Dev Dyn 239, 610-619.
  • Li, H., Palczewski, K., Baehr, W., Clagett-Dame, M., 2010. Vitamin A Deficiency Results in Meiotic Failure and Accumulation of Undifferentiated Spermatogonia in Prepubertal Mouse Testis. Biol Reprod. (published ahead of print Sept. 29, 2010)
  • Grzywacz, P., Chiellini, G., Plum, L.A., Clagett-Dame, M., DeLuca, H.F., 2010. Removal of the 26-methyl group from 19-nor-1alpha,25-dihydroxyvitamin D markedly reduces in vivo calcemic activity without altering in vitro VDR binding, HL-60 cell differentiation, and transcription. J Med Chem 53, 8642-8649.
  • Deluca, H.F., Bedale, W., Binkley, N., Gallagher, J.C., Bolognese, M., Peacock, M., Aloia, J., Clagett-Dame, M., Plum, L., 2010. The vitamin D analog 2MD increases bone turnover but not BMD in postmenopausal women with osteopenia: Results of a 1-Year, phase 2, double-blind, placebo-controlled, randomized clinical trial. J Bone Miner Res. (published ahead of print Oct. 5, 2010)


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: The overall focus of this work is the study of the fat-soluble vitamins A and D. Ongoing work in three project areas is described below. Project 1. Both nutritional and genetic approaches are being used to determine how and when vitamin A is needed for developing embryos, neonates and adults. Our laboratory has developed methods that enable the study of vitamin A function in both early and late embryonic processes, and more recently during postnatal life. When limiting amounts of atRA are provided after embryonic day (E) 10.5 in the rat, a highly reproducible and penetrant state of late fetal vitamin A-deficiency (VAD) is produced in the organs of developing fetuses. Using this method, we have recently shown that vitamin A is required for the initiation of meiosis in the female gonad. In addition, we have published a detailed characterization of the molecular events that are perturbed in the developing eye when insufficient vitamin A is present. We are also studying the function of several novel atRA responsive genes, and have shown that one of these genes (RAINB1 also known as Nav2) plays an essential role in neurite outgrowth, and in the development of the cranial nerves, eye, and brain. Project 2. Cellular and in vivo approaches are being used to address how the 4-HPR analog, 4-hydroxybenzylretinone (4-HBR), exerts its antitumor effects. In collaboration with our colleagues at the OSU, we have shown that the carbon-linked 4-HPR analog, 4-hydroxybenzylretinone (4-HBR), does not need to be hydrolyzed back to atRA to function in culture or in vivo. Further, 4-HBR is less toxic than 4-HPR, and appears to act by inducing ER stress-mediated responses. Work to further elucidate the cellular pathways that are altered by 4-HBR is underway, as are studies of its effects in developing embryos. Project 3. Additional studies in the lab are directed at developing improved vitamin analogs for the treatment of acne. Using the Rhino mouse as a model, the ability of compounds to produce a reduction in comedone size is being studied. Whereas all vitamin D analogs appear to induce thickening of the epidermis, we have identified a unique subset of analogs that also induce comedolysis. Studies are underway to determine how vitamin D compounds act to produce these effects. PARTICIPANTS: Angela See, Postdoctoral fellow; current employment Nimblegen; Hui Li, Postdoctoral fellow; Melissa Rohrer, Posdotoral fellow; Elizabeth McNeill, completed PhD; Nirca Nieves, completed PhD; Allyson Anding, PhD training ongoing; Mark Marzinke, PhD training ongoing TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The reproductive efficiency and health of animals, including humans, is clearly influenced by nutritional status. Rather than striving only to prevent overt nutrient deficiency, we need to begin to develop an understanding of "optimal" levels of a given nutrient to promote health. A detailed understanding of the physiological and molecular processes for which vitamins are needed is essential not only for optimizing human health, but also for determining how vitamin derivatives might be used in the treatment of human disease. For example, vitamin A compounds have shown promise in the prevention and treatment of cancer, as well as in the treatment of acne. However, the toxicity of many retinoids limits their use. Similar potential exists for the use of vitamin D analogs in a number of diseases, but the side effect, hypercalcemia, has been a major limitation to the advancement of these efforts. Thus studies of new vitamin A analogs and non-calcemic vitamin D analogs may offer new approaches to the treatment of several disease states, including acne and cancer. Numerous patents that have issued or have been filed through the Wisconsin Alumini Research Foundation have arisen from these studies.

Publications

  • See, AW, Clagett-Dame M. The temporal requirement for vitamin A in the developing eye: mechanism of action in optic fissure closure and new roles for the vitamin in regulating cell proliferation and adhesion in the embryonic retina. Dev Biol 2009; 325:94-105.
  • Plonska-Ocypa K, Sicinski RR, Plum LA, Grzywacz P, Frelek J, Clagett-Dame M, Deluca HF. 13-Methyl-substituted des-C,D analogs of (20S)-1alpha,25-dihydroxy-2-methylene-19-norvitamin D(3) (2MD): Synthesis and biological evaluation. Bioorg Med Chem 2009; 17:1747-1763.
  • Li H, Clagett-Dame M. Vitamin A deficiency blocks the initiation of meiosis of germ cells in the developing rat ovary in vivo. Biol Reprod 2009; 81:996-1001.
  • Li H, MacLean G, Cameron D, Clagett-Dame M, Petkovich M. Cyp26b1 expression in murine sertoli cells is required to maintain male germ cells in an undifferentiated state during embryogenesis. PLOS One 2009; 4(10):e7501.
  • Marzinke MA, Henderson EM, Yang KS, See AW-M, Knutson DC, Clagett-Dame, M. Calmin expression in embryos and the adult brain, and its regulation by all-trans retinoic acid. Dev. Dynamics 2009 (in press).


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: The overall focus of this work is the study of the fat-soluble vitamins A and D. Ongoing work in three project areas are described below. Project 1. Both nutritional and genetic approaches are being used to determine how and when vitamin A is needed for developing embryos, neonates and adults. Our laboratory has developed methods that enable the study of vitamin A function in both early and late embryonic processes, and more recently during postnatal life. Our recently published work shows that when limiting amounts of atRA are provided after embryonic day (E) 10.5 in the rat, a highly reproducible and penetrant state of late fetal vitamin A-deficiency (VAD) is produced in the organs of developing fetuses. This work shows that a large number of organ systems are adversely affected, including the eye. The optic fissure does not close, and severe folding and collapse of the retina is observed at E18.5. In our most recent work, we show that coloboma and retinal folding represent distinct VAD-dependent effects. The downregulation of Pitx2 in VAD may be related to the failure of the optic fissure to close, whereas a reduction in cyclin D1 and the cell adhesion molecules, N-cadherin and B-catenin, may play a role in the retinal thinning, folding and collapse observed in late VAD fetuses. We are also studying the function of several novel atRA responsive genes, and have found that one of these genes (RAINB1) plays an essential role in neurite outgrowth, and in the development of the cranial nerves, eye, and brain. Project 2. Cellular and in vivo approaches are being used to address how the 4-HPR analog, 4-hydroxybenzylretinone (4-HBR), exerts its antitumor effects on cancer cells. In collaboration with our colleagues at the OSU, we have found that the carbon-linked 4-HPR analog, 4-hydroxybenzylretinone (4-HBR), does not need to be hydrolyzed back to atRA to function in culture or in vivo. Our studies also indicate that 4-HBR is less toxic than 4-HPR. Recently, we reported that 4-HBR rapidly induces ER stress-mediated responses and this may represent a mechanism whereby this compound produces its chemotherapeutic effects. Work to further elucidate the cellular pathways that are altered by 4-HBR is underway. Studies of additional nonhydrolyzable compounds, including glucuronide and glucose derivatives of 4-HBR are also ongoing. Project 3. Additional studies in the lab are directed at developing improved vitamin analogs for the treatment of acne. Using the Rhino mouse as a model, the ability of compounds to produce a reduction in comedone size is being studied. We have identified a specific subset of vitamin D analogs that are effective in this model. Studies are underway to determine how vitamin D compounds act to induce comedolysis. PARTICIPANTS: See - PhD received 2008: Knutson - PhD received 2008 Muley - completed postdoctoral training; McNeill - PhD in progress TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The reproductive efficiency and health of animals, including humans, is clearly influenced by nutritional status. It is becoming abundantly clear that rather than striving only to prevent overt nutrient deficiency, that we need to begin to develop an understanding of "optimal" levels of a given nutrient to promote health. A detailed understanding of the physiological and molecular processes for which vitamins are needed is essential not only for optimizing human health, but also for determining how vitamin derivatives might be used in the treatment of human disease. For example, vitamin A compounds have shown promise in the prevention and treatment of cancer, as well as in the treatment of acne. However, the toxicity of many retinoids limits their use. Similar potential exists for the use of vitamin D analogs in a number of diseases, but the side effect, hypercalcemia, has been a major limitation to the advancement of these efforts. Thus studies of new vitamin A analogs and non-calcemic vitamin D analogs may offer new approaches to the treatment of several disease states, including acne and cancer. Numerous patents that have issued or have been filed through the Wisconsin Alumini Research Foundation have arisen from these studies.

Publications

  • See AW, Kaiser M, White JC, Clagett-Dame M. A nutritional model of late embryonic vitamin A deficiency produces defects in organogenesis at a high penetrance and reveals new roles for the vitamin in skeletal development. Developmental Biol 2008; 316:171-190.
  • Knutson DK, Clagett-Dame, M. atRA regulation of NEDD9, A gene involved in neurite outgrowth and cell adhesion. Arch Biochem Biophys 2008; 477(1)163-174.
  • Chiellini G, Grzywacz P, Plum LA, Barycki R, Clagett-Dame M, DeLuca HF. Synthesis and biological properties of 2-methylene-19-nor-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactones--weak agonists. Biorg Med Chem 2008; 16(18):8563-8573.
  • Muley PD, McNeill EM, Marzinke MA, Knobel KM, Barr MM, Clagett-Dame M. The atRA-responsive gene neuron navigator 2 functions in neurite outgrowth and axonal elongation. Dev Neurobiol 20008; 68(13):1441-1453.
  • See AW, Clagett-Dame M. The temporal requirement for vitamin A in the developing eye: mechanism of action in optic fissure closure and new roles for the vitamin in regulating cell proliferation and adhesion in the embryonic retina. 2009; 325(1):94-105; Epub 2008
  • Plonska-Ocypa K, Sicinski RR, Plum LA, Grzywacz P, Frelek J, Clagett-Dame M, Deluca HF. 13-Methyl-substituted des-C,D analogs of (20S)-1alpha,25-dihydroxy-2-methylene-19-norvitamin D(3) (2MD): Synthesis and biological evaluation. Epub 2008


Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: The overall focus of this work is the study of the fat-soluble vitamins A and D. Ongoing work in three project areas is described below. Project 1. Both nutritional and genetic approaches are being used to determine how and when vitamin A is needed for developing embryos. Our laboratory has developed methods that enable the study of vitamin A function in both early and late embryonic processes. Using this model, we have shown that vitamin A plays a critical early role in patterning the heart, hindbrain and axial skeleton. Our recently published work shows that when limiting amounts of atRA are provided after embryonic day 10.5 in the rat, a highly reproducible and penetrant state of late fetal vitamin A-deficiency (VAD) is produced in the organs of developing fetuses. These fetuses also display anteriorization of cervical regions of the skeleton and novel posteriorization events at the thoracic and sacral levels, and also show sternal and pelvic malformations not previously observed in genetic models. We are now using these nutritional models to explore the molecular mechanisms that are disrupted by embryonic vitamin A-deficiency. We are also studying the distribution and function of novel atRA responsive genes, and have found that one of these genes (RAINB1) plays an essential role in neurite outgrowth. Project 2. Cellular and in vivo approaches are being used to address how the 4-HPR analog, 4-hydroxybenzylretinone (4-HBR), exerts its antitumor effects on cancer cells. In collaboration with our colleagues at the OSU, we have found that the carbon-linked 4-HPR analog (4-HBR) does not need to be hydrolyzed back to atRA to function in culture or in vivo. Studies of the efficacy 4-HBR in chemotherapy of DMBA-induced mammary tumors in the rat show that the non-hydrolysable analog is equally effective in reducing tumor size and number, and does so without reducing blood retinol levels, an undesirable side affect associated with the use of the parent compound, 4-HPR. Although 4-HBR can bind and transactivate RARs, this is not required for it to induce cell death. Recently, we reported that 4-HBR rapidly induces ER stress-mediated responses and may represent a mechanism whereby this compound produces its chemotherapeutic effects. Project 3. Additional studies in the lab are directed at developing improved vitamin analogs for the treatment of disease. One example is the use of retinoids for the treatment of acne. A major limitation to current oral therapy is teratogenic liability. As a potential improvement, we are studying sterically hindered vitamin A analogs. Using the Rhino mouse as a model, the ability of compounds to produce a reduction in comedone size is being studied. We have also found that some vitamin D analogs are effective in this model. Studies are underway to determine whether these approaches may offer any advantage to existing therapies. PARTICIPANTS: J. Ahrens, Research Specialist M. Kaiser, Senior Research Specialist In Training E. McNeill, Research Asst A. See, Research Asst N. Nieves, Research Asst A. Anding, Research Asst D. Knutson, Research Asst TARGET AUDIENCES: Biochemical, Cellular and Molecular and Medical Research Communities, with the Intent of Increasing Knowledge, as well as, to Capitalize on the Translational Value of this Research.

Impacts
The reproductive efficiency and health of animals, including humans, is clearly influenced by nutritional status. It is becoming abundantly clear that rather than striving only to prevent overt nutrient deficiency, that we need to begin to develop an understanding of "optimal" levels of a given nutrient to promote health. A detailed understanding of the physiological and molecular processes for which vitamins are needed is essential not only for optimizing human health, but also for determining how vitamin derivatives might be used in the treatment of human disease. For example, vitamin A compounds have shown promise in the prevention and treatment of cancer, as well as in the treatment of acne. However, the toxicity of many retinoids limits their use. Similar potential exists for the use of vitamin D analogs in a number of diseases, but the side effect, hypercalcemia, has been a major limitation to the advancement of these efforts. Thus studies of new vitamin A analogs and non-calcemic vitamin D analogs may offer new approaches to the treatment of several disease states, including acne and cancer. Numerous patents that have issued or have been filed through the Wisconsin Alumini Research Foundation have arisen from these studies.

Publications

  • Mershon SM, Anding AL, Chapman JS, Clagett-Dame M, Stonerock LA, Curley Jr RW. Solid phase-assisted synthesis and screening of a small library of N-(4-hydroxyphenyl)retinamide (4-HPR) analogs. Biorganic Med Chem Lett 2007; 17:836-840.
  • Thomson B, Ahrens JM, Ntambi JM, DeLuca HF, Clagett-Dame M. 2-Methylene-19-nor-1a-hydroxyvitamin D3 analogs inhibit adipocyte differentiation and PPARY2 gene transcription. Arch Biochem Biophys 2007; 469L192-201.
  • DeLuca HF, Plum LA, Clagett-Dame M. Selective analogs of 1I,25-dihydroxyvitamin D3 for the study of specific functions of vitamin D. J Steroid Biochem Mol Biol 2007; 103:263-268.
  • Anding AL, Chapman JS, Barnett DW, Curley RW Jr, Clagett-Dame M. The unhydrolyzable fenretinide analogue 4-hydroxybenzylretinone induces the proapoptotic genes GADD153 (CHOP) and Bcl-2-binding component 3 (PUMA) and apoptosis that is caspase- dependent and independent of the retinoic acid receptor. Cancer Res 2007; 67(13):6270-6277.
  • See, AW, Kaiser M, White JC, Clagett-Dame M. A nutritional model of late embryonic vitamin A deficiency produces defects in organogenesis at a high penetrance and reveals new roles for the vitamin in skeletal development. Developmental Biol 2007 (in press).
  • Slatopolsky E, Finch JL, Brown AJ, Ritter CS, Misobuchi M,Plum LA, Clagett-Dame M, Sicinski PR, DeLuca HF. The Effect of 2 Methylene-19-nor-(20S)-1 a-hydroxy-bishomopregnacalciferol ( 2MbsP), an analog of Vitamin D, on Secondary Hyperathyroidism. J Bone Miner Res 2007: 22:686-694.