Caseins mRNAs

Fig. 6. Casein mRNA accumulation in mammary gland tissue from pregnant rats incubated in vitro in the presence of insulin and cortisol with or without prolactin (PRL). From Ref. 74.

Cyclic GMP can have some prolactin-like actions in rat mammary tissue, including stimulation of RNA synthesis and elevation of levels of casein mRNA but not... 

Cytoskeletal elements may also be involved in mediating the effects of prolactin on the mammary gland. Colchicine, which disrupts intracellular microtubules, completely blocks the effect of prolactin on casein mRNA production [86]. However, griseofulvin, another microtubule-disrupting drug, has no such effect. 

Translational and transcriptional control are sometimes combined. For example, insulin (which regulates the synthesis of a large number of substances) and prolactin (another hormone) are required together for production of casein (milk protein) in mammary tissue. Both hormones are needed to initiate transcription but prolactin in addition, increases the lifetime of casein mRNA. 

Different eukaryotic mRNAs may have widely differing half-lives and the more stable the mRNA, the more protein that can be translated from it. Various factors may affect the stability of specific mRN. For example, in the presence of the peptide hormone prolactin, casein mRNAs are specifically stabiliwd during lactation, thereby increasing the level of expression of these milk proteins. 

Hobbs, A.A. and Rosen, J.M. (1982) Sequence of rat alpha- and gamma-casein mRNAs evolutionary comparison of the calcium-dependent rat casein multi-gene family. Nucleic Acids Res., 10, 8079-8098. 

Arjmandi et al., 1998a,b 95 d old OVX rats 35 d casein diet after OVX, then 65 d soy protein with isoflavones (9 mg/d) No significant effect of soy protein in reversal of bone loss, assessed by BMD. Soy induced femoral lGF-1 mRNA and some increases in bone turnover markers... 

Oral administration of the hot-water extracts in mice suppressed the immunoglobulin E (IgE) production against casein antigen, accompanied by increased IFNy and IL-12 mRNA expression [26], Oral administration of the extracts enhanced Thl response to casein in the spleen of casein-immunized mice. The hot-water extracts may be useful for the pre-... 

Induction of milk proteins appears to involve increased transcription of the appropriate genes. Levels of mRNA for casein increase substantially [66,69,74-77] (Fig. 6), though to a lower extent than the increase in casein production, suggesting that an increased rate of translation of mRNA (or possibly decreased protein degradation) may also be important. The increased levels of mRNA may be partly due to decreased degradation as well as increased transcription [74]. 

Figure 9 RT-PCR analysis of cytokine mRNA expression in the spleens of DBA/2 mice immunized with casein/CKA. Total RNA was extracted from pooled spleens of S DHA/2 mice or CVE-administercd mice 3 weeks after immunized using RNAzol and reverse-transcribed, and the cDNA concentration was adjusted by co-amplification of two fold serially diluted cDNA and constant amounts of control plasmid pMCQ with [5-actin specific primers. Cytokine expression patterns of IL-12, IFNy, IL-6, and 11.-10 were determined by PCR using murine cytokine-specific primers. The PCR products were separated in 2 % agarose gel and visualized by ethidium bromide staining. Relative quantification of the amounts of the RT-PCR products was performed using a Computing Densitometer and NIH Image software,...

In order to confirm the effects of oral administration of CVE on the IL-12 and IFNy mRNA expressions in the spleens of mice immunized with casein/CFA, we compared the expression of cytokine genes in the spleens of untreated and CVE-treated mice after immunization with casein/CFA. Total RNA was extracted from the spleens 3 weeks after immunization. The levels of IL-12 and IFNy were augmented in the... 

Here, we showed that the production of casein-specific IgE Ab in mice immunized with casein/CFA was suppressed by oral administration of CVE, and that the production of casein-specific IgG2a levels was enhanced by oral administration of CVE, whereas the expressions of IL-12 and IFNy mRNAs were increased in the spleens of mice after immunization with casein/CFA. These results suggested that CVE may be useful as a therapeutic or prophylactic agent to control allergy accompanied by the elevation of allergen-specific IgE Abs. 

Hall, L., Laird, J.E., and Craig, R.K. (1984) Nucleotide sequence determination of guinea-pig casein B mRNA reveals homology with bovine and rat alpha si caseins and conservation of the non-coding regions of the mRNA. Biochem. J., 121, 561-570. 

---