Gene Expression Profiles in Human and Mouse Primary Cells Provide New Insights into the Differential Actions of Vitamin D-3 Metabolites

1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3) had earlier been regarded as the only active hormone. The newly identified actions of 25-hydroxyvitamin D3 (25(OH)D3) and 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) broadened the vitamin D3 endocrine system, however, the current data are fragmented and a systematic understanding is lacking. Here we performed the first systematic study of global gene expression to clarify their similarities and differences. Three metabolites at physiologically comparable levels were utilized to treat human and mouse fibroblasts prior to DNA microarray analyses. Human primary prostate stromal P29SN cells (hP29SN), which convert 25(OH)D3 into 1α,25(OH)2D3 by 1α-hydroxylase (encoded by the gene CYP27B1), displayed regulation of 164, 171, and 175 genes by treatment with 1α,25(OH)2D3, 25(OH)D3, and 24R,25(OH)2D3, respectively. Mouse primary Cyp27b1 knockout fibroblasts (mCyp27b1−/−), which lack 1α-hydroxylation, displayed regulation of 619, 469, and 66 genes using the same respective treatments. The number of shared genes regulated by two metabolites is much lower in hP29SN than in mCyp27b1−/−. By using DAVID Functional Annotation Bioinformatics Microarray Analysis tools and Ingenuity Pathways Analysis, we identified the agonistic regulation of calcium homeostasis and bone remodeling between 1α,25(OH)2D3 and 25(OH)D3 and unique non-classical actions of each metabolite in physiological and pathological processes, including cell cycle, keratinocyte differentiation, amyotrophic lateral sclerosis signaling, gene transcription, immunomodulation, epigenetics, cell differentiation, and membrane protein expression. In conclusion, there are three distinct vitamin D3 hormones with clearly different biological activities. This study presents a new conceptual insight into the vitamin D3 endocrine system, which may guide the strategic use of vitamin D3 in disease prevention and treatment.Peer reviewe

The Suok Test of Anxiety — the New Rodent Behavioral Paradigm Which Opens Minds

Proceedings of the 9th International Multidisciplinary Conference «Stress and Behavior» Saint-Petersburg, Russia, 16–19 May 2005.In a series of our pilot studies (Kalueff, Tuohimaa, 2005), we have introduced the Suok test (ST) — a long elevated horizontal rod (mice) or alley (rats) and the light-dark ST modification (LDST) for behavioral characterization in small rodents, including simultaneous assessment of their anxiety, activity, and neurological phenotypes. The unique feature of this test is its ability to simultaneously assess these three distinct behavioral domains. To establish the ST and the LDST as murine models of anxiety, we used several different mouse strains which differ markedly in their anxiety and activity (C57BL/6, 129S1/SvImJ, NMRI, and BALB/c), showing that our tests are able to ethologically discriminate between high and low anxiety mouse strains, as assessed by horizontal and directed exploration, stops, and defecation boli (Kalueff, Tuohimaa, 2005). The spatial distribution of the LDST behaviors is also sensitive to these strain-specific anxiety phenotypes, showing clear avoidance of the brightly lit part of the test in stressed vs. non-stressed mice. In addition, we validated the ST in 129S1/SvImJ and BALB/c mice by assessing the behavioral consequences of acute stress such as rat exposure. We also showed that our test is able to detect high anxiety and poorer motor coordination in 129S1/SvImJ (vs. C57BL/6) mice (Kalueff, Tuohimaa, 2005). Similar, although not identical, behavioral results were obtained in rats using different types of stress (light exposure, novelty, chemical challenge, etc). The results of our studies show that the ST emerges as an experimental tool to analyze anxiety, motor-vestibular anomalies, as well as anxiety-induced motor impairments in mice and rats. In general, it may be suggested that the ST represent a hybrid model combining several well-validated behavioral models: 1) open field test (open unknown area), 2) elevated plus maze (elevated platform), 3) rotarod test (horizontal confined bar). In addition, the LDST is the combination of features of these three tests with the light-dark box paradigm. Recently, the ST was used in both mice and rats in order to pharmacologically validate this method using reference GABAergic drugs — anxiolytic diazepam (DZ, 0.5–1 mg/kg i.p.) and axiogenic pentylenetetrazole (PTZ, 10–15 mg/kg i.p.). We showed that the ST works consistently in both species, predictably increasing anxiety and motor incoordination in PTZ-treated animals, and showing the opposite effects after DZ. Overall, we suggest that the ST can be a useful protocol in neurobehavioral stress research including modeling stress-evoked states, pharmacological screening of potential anti-stress drugs, or behavioral phenotyping of genetically modified animals. Here we will review different behavioral features of the rat and mouse ST, critically overview species-specific behavioral differences in these tests, and discuss potential utility of this new model for behavioral pharmacology and biological psychiatry

The Suok Test of Anxiety — the New Rodent Behavioral Paradigm Which Opens Minds

Proceedings of the 9th International Multidisciplinary Conference «Stress and Behavior» Saint-Petersburg, Russia, 16–19 May 2005.In a series of our pilot studies (Kalueff, Tuohimaa, 2005), we have introduced the Suok test (ST) — a long elevated horizontal rod (mice) or alley (rats) and the light-dark ST modification (LDST) for behavioral characterization in small rodents, including simultaneous assessment of their anxiety, activity, and neurological phenotypes. The unique feature of this test is its ability to simultaneously assess these three distinct behavioral domains. To establish the ST and the LDST as murine models of anxiety, we used several different mouse strains which differ markedly in their anxiety and activity (C57BL/6, 129S1/SvImJ, NMRI, and BALB/c), showing that our tests are able to ethologically discriminate between high and low anxiety mouse strains, as assessed by horizontal and directed exploration, stops, and defecation boli (Kalueff, Tuohimaa, 2005). The spatial distribution of the LDST behaviors is also sensitive to these strain-specific anxiety phenotypes, showing clear avoidance of the brightly lit part of the test in stressed vs. non-stressed mice. In addition, we validated the ST in 129S1/SvImJ and BALB/c mice by assessing the behavioral consequences of acute stress such as rat exposure. We also showed that our test is able to detect high anxiety and poorer motor coordination in 129S1/SvImJ (vs. C57BL/6) mice (Kalueff, Tuohimaa, 2005). Similar, although not identical, behavioral results were obtained in rats using different types of stress (light exposure, novelty, chemical challenge, etc). The results of our studies show that the ST emerges as an experimental tool to analyze anxiety, motor-vestibular anomalies, as well as anxiety-induced motor impairments in mice and rats. In general, it may be suggested that the ST represent a hybrid model combining several well-validated behavioral models: 1) open field test (open unknown area), 2) elevated plus maze (elevated platform), 3) rotarod test (horizontal confined bar). In addition, the LDST is the combination of features of these three tests with the light-dark box paradigm. Recently, the ST was used in both mice and rats in order to pharmacologically validate this method using reference GABAergic drugs — anxiolytic diazepam (DZ, 0.5–1 mg/kg i.p.) and axiogenic pentylenetetrazole (PTZ, 10–15 mg/kg i.p.). We showed that the ST works consistently in both species, predictably increasing anxiety and motor incoordination in PTZ-treated animals, and showing the opposite effects after DZ. Overall, we suggest that the ST can be a useful protocol in neurobehavioral stress research including modeling stress-evoked states, pharmacological screening of potential anti-stress drugs, or behavioral phenotyping of genetically modified animals. Here we will review different behavioral features of the rat and mouse ST, critically overview species-specific behavioral differences in these tests, and discuss potential utility of this new model for behavioral pharmacology and biological psychiatry