Chemistry: molecular biology and microbiology – Micro-organism – tissue cell culture or enzyme using process... – Recombinant dna technique included in method of making a...
Reexamination Certificate
2001-08-30
2004-11-02
Priebe, Scott D. (Department: 1632)
Chemistry: molecular biology and microbiology
Micro-organism, tissue cell culture or enzyme using process...
Recombinant dna technique included in method of making a...
C435S320100, C435S325000, C435S455000, C536S023100, C536S023500
Reexamination Certificate
active
06812002
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the identification of an isolated, full-length rat nucleic acid molecule encoding an osteoactivin protein, therapeutic compositions comprising an osteoactivin protein, and methods for using the nucleic acid molecules and proteins for stimulating bone differentiation. The invention also relates to methods for treating bone disorders, including osteopetrosis and osteoporosis.
BACKGROUND OF THE INVENTION
The formation and maintenance of the vertebrate skeleton requires the interactions of many cell types and growth factors and other molecules. The past decade has witnessed an explosive growth in the general understanding of growth factors and other proteins that mediate the complex coordination of bone formation and bone resorption by these different cell types in skeletal modeling and remodeling (Popoff and Marks,
Oral and Maxillofacial Clinics of North America
9:563-579 (1997)).
In general, the bone remodeling cycle involves a complex series of sequential steps that are highly regulated. The initial “activation” phase of bone remodeling begins early in fetal life and is dependent on the effects of local and systemic growth factors on mesenchymal cells of the osteoblast lineage (Eriksen,
Endocrinol. Rev.
7:379-408 (1986)). These cells interact with hematopoietic precursors to form osteoclasts in the “resorption” phase. This leads to the differentiation, migration and fusion of the large multinucleated osteoclasts. These cells attach to the mineralized bone surface and initiate resorption by the secretion of hydrogen ions and lysosomal enzymes. Osteoclastic resorption produces irregular scalloped cavities on bone surface. Once the osteoclasts have completed their work of bone removal, there is a “reversal” phase during which mononuclear cells, which may be of the macrophage lineage, are present on the bone surface. These cells further degrade collagen, deposit proteoglycans, and release growth factors that signal the initiation of the “formation” phase. During the final formation phase of the remodeling cycle, the cavity created by resorption can be completely filled in with successive layers of osteoblasts, which differentiate from their mesenchymal precursors and lay down a mineralizable matrix. (Raisz,
Clin. Chem.
45:1353-1358 (1999)).
With bone disorders associated with decreased bone mass, osteoclastic resorption outweighs osteoblastic bone formation, resulting in bone loss. While treatments that stimulate bone formation would be beneficial in treating or preventing bone loss, current therapies are suboptimal (Canalis,
J. Clin. Invest.
106:177-179 (2000); Raisz,
J. Bone Min. Metab
17:79-89 (1999)).
An animal model useful in bone studies is the osteopetrosis (op) mutation in the rat. Osteopetrosis describes a group of congenital bone disorders that are characterized by a generalized increase in skeletal mass resulting from a primary defect in osteoclast-mediated bone resorption (Popoff and Schneider,
Molec. Med. Today
2:349-358 (1996)). Numerous osteopetrotic mutations have been described in other species, including human and mouse. The bone that is formed as the skeleton develops and grows in animals with this mutation is not resorbed, resulting in the failure to develop bone marrow cavities. The osteopetrotic mutations are pathogenetically heterogeneous since the point at which osteoclast development or activation is intercepted differs for each mutation (Popoff and Marks,
Bone
17:437-445 (1995)). Although osteoclast hypofunction is universal among the osteopetrotic mutations, genetic abnormalities involving osteoblast development/function (i.e., bone formation), mineral homeostasis and the immune and endocrine systems have also been reported within this disorder (Seifert et al.,
Clin. Orthop.
294:23-33 (1993)).
To date, pharmaceutical approaches to managing osteoporosis or osteopetrosis are of limited effectiveness. Therefore, alternative therapies are needed to modulate bone cell differentiation and bone formation, and to treat bone disorders such as osteoporosis and osteopetrosis.
SUMMARY OF THE INVENTION
The present invention is based, in part, on the discovery of a novel rat gene encoding an osteoactivin protein. The nucleotide sequence of full-length cDNA of the gene is shown in SEQ ID NO:1. The nucleotide sequence of the cDNA encoding the osteoactivin protein is shown in nucleotides 115 to 1,830 of SEQ ID NO:1 and the corresponding amino acid sequence of the osteoactivin protein is shown in SEQ ID NO:2. The polynucleotide sequence of the cDNA encoding the osteoactivin protein lacking the signal sequence is shown in nucleotides 181-1830 of SEQ ID NO:1 and the corresponding osteoactivin polypeptide lacking the signal sequence is from amino acid residues 23-572 of SEQ ID NO:2. The claimed invention also relates to antibodies which recognize one or more epitopes of the osteoactivin protein. The claimed invention provides therapeutic compositions comprising (i) a nucleic acid molecule encoding an osteoactivin protein, (ii) an osteoactivin protein, or (iii) an antibody to an osteoactivin protein. These therapeutic compositions are useful to treat bone disorders and to stimulate bone formation and bone cell differentiation.
Accordingly, in one aspect, the invention is directed to molecules encoding an osteoactivin protein. One embodiment of this aspect is a nucleic acid molecule encoding a rat osteoactivin protein having a molecular weight of 63.8 kilodaltons (kD), wherein said osteoactivin protein stimulates bone cell differentiation. In a related embodiment of this aspect, the invention encompasses a full-length nucleic acid molecule which encodes an osteoactivin protein, wherein said nucleic acid comprises the nucleic acid sequence of SEQ ID NO:1. In another embodiment, the invention provides a nucleic acid molecule encoding an osteoactivin protein, wherein said nucleic acid hybridizes to the complement of SEQ ID NO:1 under moderately stringent conditions. In a preferred embodiment, the nucleic acid molecule encoding an osteoactivin protein having at least 92% sequence identity with the nucleic acid sequence of SEQ ID NO:1 is described. In some embodiments, the nucleic acid molecule encodes a polypeptide comprising SEQ ID NO:2. The invention also embodies the nucleic acid molecule encoding an osteoactivin polypeptide comprising amino acid residues 23-572 of SEQ ID NO:2. In other embodiments, the invention provides a nucleic acid encoding an osteoactivin protein, wherein said nucleic acid comprises from nucleotide 115 to nucleotide 1,830 of SEQ ID NO:1. Other embodiments of the invention provide a polynucleotide encoding an osteoactivin protein lacking the leader sequence, wherein said polynucleotide comprises from nucleic acid residues from 181 to1830 of SEQ ID NO:1. In still other embodiments, the invention provides a nucleic acid encoding an osteoactivin protein, wherein said nucleic acid molecule hybridizes to the complement of nucleotide 115 to nucleotide 1,830 of SEQ ID NO:1 under moderately stringent conditions. In yet another embodiment of this aspect, the invention further provides a nucleic acid molecule encoding an osteoactivin protein having at least 92% sequence identity with the nucleic acid sequence from nucleotide 115 to nucleotide 1,830 of SEQ ID NO:1.
As used herein, the term “nucleic acid molecule” includes DNA molecules (e.g., a cDNA or genomic DNA) and RNA molecules (e.g., an mRNA) and analogs of the DNA or RNA generated, e.g., by the use of nucleotide analogs. The nucleic acid molecule can be single-stranded or double-stranded, but preferably is double-stranded DNA. Nucleic acid molecules include naturally occurring nucleic acid molecules which are separated from other molecules which are present in the natural source of the nucleic acid. For example, a nucleic acid molecule includes genomic DNA which is separated from the chromosome with which the genomic DNA is naturally associated. Preferably, a naturally occurring nucleic acid molecule is free of sequences which naturally fl
Owen Thomas A.
Popoff Steven N.
Safadi Fayez F.
Smock Steven L.
Clark & Elbing LLP
Pfizer Inc.
Priebe Scott D.
LandOfFree
Osteoactivin protein and nucleic acids encoding the same,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Osteoactivin protein and nucleic acids encoding the same,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Osteoactivin protein and nucleic acids encoding the same,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3284364