The Calcitonin and Glucocorticoids Combination: Mechanistic Insights into Their Class-Effect Synergy in Experimental Arthritis

PMCID: PMC3564948This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Glucocorticoid modulation of casein gene transcription in mouse mammary gland

The influence of cortisol and prolactin on casein gene expression in the mammary gland of lactating BALB/c mice was measured by using a specific cDNA probe to 15S casein mRNA (cDNAcsn). Casein mRNA (mRNAcsn) level in the mammary gland was decreased by 85% 5 days after adrenal ablation, but then was increased 4.4-fold 12 hr after a single injection of hydrocortisone-21-acetate. An 80% decrease in serum prolactin level, induced by the prolactin inhibitor 2- bromo-α-ergocryptin (CB-154), did not alter the level of mRNAcsn in the gland. Specific transcription of the casein gene in nuclei isolated from lactating mammary glands was measured by cDNAcsn hybridization to the in vitro synthesized Hg-CTP-containing RNA (Hg-RNA), which was purified by SH-agarose chromatography. The level of the mRNAcn in Hg-RNA synthesized in the isolated nuclei was 0.09% and this was decreased 85% by α-amanitin, indicating that the mRNAcsn sequences in the Hg-RNA were the products of RNA polymerase II-directed DNA-dependent RNA synthesis. Transcription of the mRNAcsn in isolated nuclei was decreased by 70% 5 days after adrenalectomy and a single injection of the glucocorticoid then increased the transcription level 2-fold at 6 hr. Essentially no alteration of the level of transcription was detectable in mammary nuclei isolated from lactating mice with 80% decreased serum prolactin level, induced by CB-154 treatment. The results thus demonstrate a glucocorticoid involvement on the modulation of casein gene expression at the transcriptional level of control

Proresolving and Tissue-Protective Actions of Annexin A1–Based Cleavage-Resistant Peptides Are Mediated by Formyl Peptide Receptor 2/Lipoxin A4 Receptor

Abstract Endogenous mechanisms regulating the host response during inflammation resolution are critical in ensuring disposal of noxious stimuli and return to homeostasis. In this article, we engineered novel Annexin A1 (AnxA1)–based peptides, AnxA12–50, that displayed specific binding to the AnxA1 receptor (formyl peptide receptor 2/Lipoxin A4 receptor [FPR2/ALX]; IC50 ∼4 nM). Intravenous administration of AnxA12–50 markedly reduced (&amp;gt;60%) leukocyte adhesion to postcapillary venules in wild type and Fpr1−/−, but not Fpr2/Alx−/−, mice. Generation of a metabolically stable form of this peptide (CR-AnxA12–50), engineered by substituting a cleavage site shared by human proteinase 3 and neutrophil elastase, yielded an agonist that was resistant to neutrophil-mediated cleavage and displayed enhanced proresolving actions: accelerated resolution of self-limited inflammation and enhanced macrophage efferocytosis after sterile injury, when compared with AnxA12–50. These actions were retained with human primary leukocytes where CR-AnxA12–50 decreased neutrophil–endothelial interactions (∼25–45%), and stimulated neutrophil apoptosis and macrophage efferocytosis (∼45%). In murine cardiac ischemia/reperfusion injury, CR-AnxA12–50 elicited tissue-protective actions reducing infarct size (∼60%) and incidence of 24-h death. These results identify AnxA12–50 and CR-AnxA12–50 as FPR2/ALX agonists that harness the proresolving actions of AnxA1, and thus may represent therapeutic tools for treatment of inflammatory conditions.</jats:p

Cloning of mouse [beta]-casein gene sequences

Casein messenger RNAs (mRNAcsn) were purified from lactating mammary glands of BALB/c mice and used as a starting material for cloning of casein gene sequences. Double-stranded casein cDNA (ds-cDNAscn) was prepared and blunt-end ligated to HindIII-specific DNA linker molecules. After digestion with HindIII, the dsDNAcsn was inserted into the HindIII site of plasmid pBR322, using T4 DNA ligase. Escherchia coli strain RH202 was transformed with the hybrid plasmids, and transformants were selected for resistance to ampicillin. Electrophoresis of HindIII-digested hybrid plasmid DNAs, followed by Souther transfer and hybridization to 9[32P]cDNAcsn, revealed that one of the hybrid-plasmid-containing colonies, designated pCas51, contained a 400-bp insert which hybridized to the [32P]cDNAcsn. Purification of the individual casein mRNAs (mRNAcsn [alpha], [beta] and [gamma]) and solution hybridization of nick-translated insert DNA to each of these revealed that pCas51 contained sequences complementary primarily to mRNAcsn [beta].Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24211/1/0000470.pd

Additive Effects of Mechanical Marrow Ablation and PTH Treatment on de Novo Bone Formation in Mature Adult Rats

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