Method of cell culture using neurturin

Details Method of cell culture using neurturin Method of cell culture using neurturin

1998-12-23

2004-06-01

Pak, Michael (Department: 1646)

Chemistry: molecular biology and microbiology

Animal cell, per se ; composition thereof; process of...

Method of regulating cell metabolism or physiology

C435S375000

Reexamination Certificate

active

06743628

ABSTRACT:

BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates generally to trophic or growth factors and, more particularly, to the novel growth factor, neurturin.
(2) Description of the Related Art
The development and maintenance of tissues in complex organisms requires precise control over the processes of cell proliferation, differentiation, survival and function. A major mechanism whereby these processes are controlled is through the actions of polypeptides known as “growth factors”. These structurally diverse molecules act through specific cell surface receptors to produce these actions.
In recent years it has become apparent that growth factors fall into classes, i.e. families or superfamilies based upon the similarities in their amino acid sequences. Examples of such families that have been identified include the fibroblast growth factor family, the neurotrophin family and the transforming growth factor-beta (TGF-&bgr;) family.
Of particular importance are those growth factors, termed “neurotrophic factors”, that promote the differentiation, growth and survival of neurons and reside in the nervous system or in innervated tissues. Nerve growth factor (NGF) was the first neurotrophic factor to be identified and characterized (Levi-Montalcini et al.,
J. Exp. Zool
. 116:321, 1951 which is incorporated by reference). NGF exists as a non-covalently bound homodimer. This factor promotes the survival and growth of sympathetic, neural crest-derived sensory, and basal forebrain cholinergic neurons. In sympathetic neurons this substance produces neurite outgrowth in vitro and increased axonal and dendritic growth in vivo. Early indications as to the physiological roles of NGF were obtained from in vivo studies involving the administration of neutralizing antibodies (Levi-Montalcini and Booker,
Proc Nat′l Acad Sci
46:384-391, 1960; Johnson et al.
Science
210: 916-918, 1980 which are incorporated by reference), and these studies have been confirmed by analyzing transgenic mice lacking NGF via gene targeting (Crowley et al.,
Cell
76:1001-12, 1994 which is incorporated by reference). NGF has effects on cognition and neuronal plasticity, and can promote the survival of neurons that have suffered damage due to a variety of mechanical, chemical, viral, and immunological insults (Snider and Johnson,
Ann Neurol
26:489-506, 1989; Hefti,
J. Neurobiol
25:1418-35, 1994 which are incorporated by reference). NGF also is known to extensively interact with the endocrine system and in immune and inflammatory processes. (Reviewed in Scully and Otten,
Cell Biol Int
19:459-469, 1995; Otten and Gadient,
Int. J. Devl Neurosci
13:147-151, 1995 which are incorporated by reference). For example, NGF promotes the survival of mast cells. (Horigome et al.
J. Biol Chem
269:2695-2707, 1994 which is incorporated by reference).
It became apparent that NGF was the prototype of a family of neurotrophic factors upon the discovery and cloning of brain-derived neurotrophic factor (BDNF) (Liebrock et al.
Nature
341:149-152, 1989 which is incorporated by reference), which was the second member of this family to be discovered. The relationship of BDNF to NGF, is evidenced in the conservation of all six cysteines that form the three internal disulfides of the NGF monomer (Barde, Prog
Growth Factor Res
2:237-248, 1990 which is incorporated by reference). By utilizing the information provided by BDNF of the highly conserved portions of two factors, additional members (NT-3, NT-4/5) of this neurotrophin family were rapidly found by several groups (Klein,
PASEB J
8:738-44, 1994 which is incorporated by reference). Information concerning their distribution and activities, and the physiologic consequences of their deficiencies (via gene targeting), has greatly increased our knowledge of neuronal development (for reviews, see Jelsma et al.,
Curr Opin Neurobiol
4:717-25, 1995; Lindsay et al.,
Trends Neurosci
17:182-90, 1994; and Johnson et al.,
Curr Biol
4:662-5, 1994 which are incorporated by reference). For instance, it is now clear that the various neurotrophins act on largely non-overlapping neuronal populations (e.g. motor neurons, sub-populations of sensory neurons), and regulate their survival and metabolism in ways similar to those originally described for NGF. Their identification has also led to refinements in the neurotrophic hypothesis, as evidence has accumulated that neurons can switch their neurotrophin survival requirements during maturation (for review, see Davies,
Curr Biol
4:273-6, 1994 which is incorporated by reference).
Recently, the understanding of the mechanisms of signal transduction for neurotrophic factors has been advanced by the identification of receptors for the NGF family of neurotrophic factors. The tyrosine kinase receptor, trkA, identified as the NGF receptor and the closely related receptors trkB, which mediates signaling of BDNF and NT-4/5, and trkC, which mediates effects of NT-3, have allowed dissection of the signal transduction pathways utilized by these neurotrophins (for review, see (Tuszynski et al.,
Ann Neurol
35:S9-S12, 1994 which is incorporated by reference). Signaling by NGF involves proteins which interact directly with the phosphorylated trkA receptor (e.g. Shc, PLC&ggr;1, PI-3 kinase), other trkA substrates like SNT (Rabin et al.,
Mol Cell Biol
13:2203-13, 1995 which is incorporated by reference), and downstream kinase effectors (e.g. ras, raf1, MEK and MAP kinase). In some cases, particular components have been linked to specific actions of NGF, such as Shc and PLC&ggr;1 requirement for neurite outgrowth (Loeb et al.,
J Biol Chem
269:8901-10, 1994; Stephens et al.,
Neuron
12:691-705, 1994 which is incorporated by reference) and PI-3 kinase requirement for survival (Yao and Cooper,
Science
267:2003-6, 1995 which is incorporated by reference).
In addition to the discovery of molecules related to NGF, structurally unrelated neurotrophic factors have also been recently identified. These include factors originally isolated based upon a “neurotrophic action” such as ciliary neurotrophic factor (CNTF) (Lin et al.,
Science
246:1023-5, 1989 which is incorporated by reference) along with others originally isolated as a result of non-neuronal activities (e.g. fibroblast growth factors (Cheng and Mattson
Neuron
1:1031-41, 1991 which is incorporated by reference), IGF-I (Kanje et al,
Brain Res
486:396-398, 1989 which is incorporated by reference) leukemia inhibitory factor (Kotzbauer et al,
Neuron
12:763-773, 1994 which is incorporated by reference).
Glial-derived neurotrophic factor (GDNF), is one such neurotrophic factor structurally unrelated to NGF. GDNF was, thus, a unique factor, which, up until now, was not known to be a member of any subfamily of factors. The discovery, purification and cloning of GDNF resulted from a search for factors crucial to the survival of midbrain dopaminergic neurons, which degenerate in Parkinson's disease. GDNF was purified from rat B49 glial cell conditioned media (Lin et al.,
Science
260:1130-2, 1993 which is incorporated by reference). Sequence analysis revealed it to be a distant member of the superfamily of transforming growth factor &bgr; (TGF-&bgr;) factors, having approximately 20% identity based primarily on the characteristic alignment of the 7 cysteine residues (Lin et al.,
Science
260:1130-2, 1993 which is incorporated by reference). Thus, GDNF could possibly have represented a new subfamily within the TGF-&bgr; superfamily.
GDNF, like other members of the TGF-&bgr; superfamily, has a precursor molecule, with a signal sequence and variably sized pro-region, that is generally cleaved at an RXXR site to release the 134 amino acid mature protein, GDNF. Thus, GDNF is synthesized as a precursor protein.
Subsequent processing results in a mature glycosylated homodimer of approximately 35-40 kD. Six of the seven cysteines form intrachain disulfide bonds and connect hydrogen-bonded &bgr;-sheets to make a rigid structure called a cystine knot (McDonald et al.,
Cell
73:4

Affiliated with

Also associated with

Rating

Method of cell culture using neurturin does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of cell culture using neurturin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of cell culture using neurturin will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3348277