Mutations in LRRK2 underlie an autosomal-dominant, inherited form of Parkinson's disease (PD) that mimics the clinical features of the common "sporadic" form of PD. The LRRK2 protein includes putative GTPase, protein kinase, WD40 repeat, and leucine-rich repeat (LRR) domains of unknown function. Here we show that PD-associated LRRK2 mutations display disinhibited kinase activity and induce a progressive reduction in neurite length and branching both in primary neuronal cultures and in the intact rodent CNS. In contrast, LRRK2 deficiency leads to increased neurite length and branching. Neurons that express PD-associated LRRK2 mutations additionally harbor prominent phospho-tau-positive inclusions with lysosomal characteristics and ultimately undergo apoptosis.

Hypoxia-inducible factor 1α (HIF-1α) and HIF-2α display unique and sometimes opposing activities in regulating cellular energy homeostasis, cell fate decisions, and oncogenesis. Macrophages exposed to hypoxia accumulate both HIF-1α and HIF-2α, and overexpression of HIF-2α in tumor-associated macrophages (TAMs) is specifically correlated with high-grade human tumors and poor prognosis. However, the precise role of HIF-2α during macrophage-mediated inflammatory responses remains unclear. To fully characterize cellular hypoxic adaptations, distinct functions of HIF-1α versus HIF-2α must be elucidated. We demonstrate here that mice lacking HIF-2α in myeloid cells (Hif2a Δ/Δ mice) are resistant to lipopolysaccharide-induced endotoxemia and display a marked inability to mount inflammatory responses to cutaneous and peritoneal irritants. Furthermore, HIF-2α directly regulated proinflammatory cytokine/chemokine expression in macrophages activated in vitro. Hif2a Δ/Δ mice displayed reduced TAM infiltration in independent murine hepatocellular and colitisassociated colon carcinoma models, and this was associated with reduced tumor cell proliferation and progression. Notably, HIF-2α modulated macrophage migration by regulating the expression of the cytokine receptor M-CSFR and the chemokine receptor CXCR4, without altering intracellular ATP levels. Collectively, our data identify HIF-2α as an important regulator of innate immunity, suggesting it may be a useful therapeutic target for treating inflammatory disorders and cancer.

We have identified for the first time the molecular profile of ovarian tumor vasculature. We demonstrate that TVMs may serve as potential biomarkers and molecular targets for ovarian cancer and a variety of other solid tumors.