Hi togo,
LRRK2 is a protein which is needed for the normal function of a cell. Mutations in LRRK2 gene results in a faulty protein and that is what is correlated with PD. If curcumin induces the expression of LRRK2, which simply means that exposure to curcumin results in making of LRRK2 protein is not a bad thing. As long as curcumin induces normal LRRK and not the mutated one, we are safe!!

Here is an abstract on LRRK2
Trends Neurosci. 2006 May;29(5):286-93. Epub 2006 Apr 17.
LRRK2 in Parkinson's disease: protein domains and functional insights.

Mata IF, Wedemeyer WJ, Farrer MJ, Taylor JP, Gallo KA.

Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, FL 32224, USA.
Abstract

Parkinson's disease (PD) is the most common motor neurodegenerative disease. Mutations in the gene encoding leucine-rich repeat kinase 2 (LRRK2) have been linked recently with autosomal-dominant parkinsonism that is clinically indistinguishable from typical, idiopathic, late-onset PD. Thus, the protein LRRK2 has emerged as a promising therapeutic target for treatment of PD. LRRK2 is extraordinarily large and complex, with multiple enzymatic and protein-interaction domains, each of which is targeted by pathogenic mutations in familial PD. This review places the PD-associated mutations of LRRK2 in a structural and functional framework, with the ultimate aim of deciphering the molecular basis of LRRK2-associated pathogenesis. This, in turn, should advance our understanding and treatment of familial and idiopathic PD.

Hope it helps

girija