Analysis of the ApoD gene promoter region identified a large number of regulatory elements, among which response elements to steroids, estrogen, progesterone and glucocorticoids.
Response elements to fatty acids, acute phase, serum and to the immune factor NFkB were also observed.
 The presence of such a large number of regulatory sequences suggests that the regulation of its expression is very complex.


ApoD has been identified in 6 mammalian species as well as in chickens, fruit flies, plants and bacteria.
In humans, monkeys, rabbits and guinea pigs, ApoD is highly expressed in the nervous system (brain, cerebellum and peripheral nerves).
Otherwise, expression levels of ApoD vary largely from organs to organs and species to species, with humans displaying the most diverse expression of ApoD, and mice and rats almost exclusively expressing ApoD in the nervous system (see Figure 2).

 
ApoD concentration in human plasma varies between 5 and 23 mg/100 ml.
In the nervous system, the ApoD mRNA is expressed by fibroblasts, astrocytes and oligodendrocytes As a glycoprotein with a peptide signal, ApoD is secreted.
Yet it can also be actively reinternalized.
The transmembrane glycoprotein Basigin (BSG; CD147) was identified as an ApoD receptor.
BSG is a membrane glycoprotein receptor, member of the immunoglobulin family, involved in several pathologies such as cancer and Alzheimer’s disease.
Analysis of the ApoD gene promoter region identified a large number of regulatory elements, among which response elements to steroids, estrogen, progesterone and glucocorticoids. Response elements to fatty acids, acute phase, serum and to the immune factor NFkB were also observed.  The presence of such a large number of regulatory sequences suggests that the regulation of its expression is very complex.

ApoD has been identified in 6 mammalian species as well as in chickens, fruit flies, plants and bacteria. In humans, monkeys, rabbits and guinea pigs, ApoD is highly expressed in the nervous system (brain, cerebellum and peripheral nerves). Otherwise, expression levels of ApoD vary largely from organs to organs and species to species, with humans displaying the most diverse expression of ApoD, and mice and rats almost exclusively expressing ApoD in the nervous system (see Figure 2). 
 
ApoD concentration in human plasma varies between 5 and 23 mg/100 ml. In the nervous system, the ApoD mRNA is expressed by fibroblasts, astrocytes and oligodendrocytes As a glycoprotein with a peptide signal, ApoD is secreted. Yet it can also be actively reinternalized. The transmembrane glycoprotein Basigin (BSG; CD147) was identified as an ApoD receptor. BSG is a membrane glycoprotein receptor, member of the immunoglobulin family, involved in several pathologies such as cancer and Alzheimer’s disease.
Apolipoprotein D