Model Systems for Studying Kisspeptin Signalling: Mice and Cells - Kisspeptin Signaling in Reproductive Biology - page 485

Table 22.2 Cell lines with kisspeptin expression

Detection
method Cell Line Origin References Comments

LNCaP Human prostatic

carcinomas

RIA [ 98 ] Highest kisspeptin secretion

from DU145 cell line

PC3 Mainly Kp54 secreted

DU145

MIN6 Mouse insuloma RT-PCR [ 99 ] Kp has been reported to

increase insulin secretion
from mouse Islets of
Langerhans in culture

Jeg3 Human placental

choriocarcinoma

RT-PCR WHC,

unpublished

MCF-7 Human breast

adenocarcinoma

RT-PCR [ 100 ] High Kiss1 expression

correlates with high
expression of AP-2a
transcription factor

rHypoE-7 Embryonic rat

hypothalamus

RT-PCR [ 91 ] Immortalized by SV40

T-antigen

rHypoE-8
mHypo- 36/1

Embryonic mouse
hypothalamus

RT-PCR [ 90 , 92 ] Immortalized by SV40

T-antigen

Mouse Consortium (IKMC, http://www.knockoutmouse.org/ ), will generate mice
with reproductive defects and thereby identify novel genes involved in this process.
The remit of the IKMC is to mutate all protein coding genes in mice through gene
targeting and gene trapping in C57Bl/6 ES cells [ 94 , 95 ]. Some of these gene target-
ing vectors produce a mutant allele that can be used to generate mice with a LacZ
reporter—tagged allele, a LoxP conditional allele or a null allele [ 96 ].
Transgenic mice may also be used to examine the way in which Kiss1 neurons
integrate within the neuronal circuitry of the hypothalamus and how their function
is co-ordinated with different physiological states. A fundamental step in under-
standing how Kiss1 neurons are regulated by upstream signals requires an accurate
defi nition of their neuronal connections. One approach would be to use a genetically
modifi ed pseudorabies virus that requires a CRE-mediated recombination event to
generate a replication competent virus [ 97 ]. Delivery of this virus into Kiss-CRE
transgenic mice will activate the virus specifi cally in Kiss1 neurons and allow retro-
grade spread into synaptically connected neurons, which can be visualized by GFP.
Using this approach it should be possible to trace primary, secondary and tertiary
inputs into Kiss1 neurons to map the neuronal circuitry.
Model systems have been essential in understanding the role of kisspeptin sig-
nalling in regulating the mammalian reproductive axis. Studies using cell lines pro-
vide important clues about regulatory pathways, which can be confi rmed in vivo
using transgenic mice. Transgenic mice will continue to be used to answer funda-
mental questions such as the interplay between NKB, dynorphin and other neuro-
modulators in regulating Kiss1 neuronal activity and GnRH pulsatility, identifi cation
of upstream regulators of Kiss1 and how Kiss1 neurons are regulated by afferent
inputs from other regions of the brain.