Abstract: Disclosed herein are methods and compositions for identifying morphogen analogs. Preferred methods rest on the use of test cells comprising DNA defining a morphogen-responsive transcription activating element operatively associated with a reporter gene. In certain embodiments, the methods involve an osteogenic protein 1 (OP-1) responsive transcription activating element. Substances that activate the OP-1 responsive transcription activating element are considered herein likely to be useful for reproducing in vivo effects of morphogens such as OP-1.

Abstract: The present invention is directed to methods and compositions for alleviating tissue destructive effects associated with the inflammatory response to tissue injury in a mammal. The methods and compositions include administering a therapeutically effective concentration of a morphogen or morphogen-stimulating agent sufficient to alleviate immune cell-mediated tissue destruction.

Abstract: The present invention provides a system for controlled transgene transcription using chimeric activator and repressor proteins functioning in a novel regulatory network. The target transgene is actively silenced in non-inducing conditions by a novel class of chimeric proteins consisting of the DNA-binding tetracycline repressor fused to distinct multimerized eukaryotic transcriptional repression domains. In the presence of a tetracycline "inducer", the repressor does not bind to the promoters for both the target gene and for another regulatory gene encoding a transactivator (e.g., GAL4-VP16). Under these inducing conditions, the transactivator activates expression of the target transgene and of its own gene, in an additional autoregulatory positive feedback loop.