Purkinje cells originate from cerebellar ventricular zone progenitors positive for Neph3 and E-cadherin

AbstractGABAergic Purkinje cells (PCs) provide the primary output from the cerebellar cortex, which controls movement and posture. Although the mechanisms of PC differentiation have been well studied, the precise origin and initial specification mechanism of PCs remain to be clarified. Here, we identified a cerebellar and spinal cord GABAergic progenitor-selective cell surface marker, Neph3, which is a direct downstream target gene of Ptf1a, an essential regulator of GABAergic neuron development. Using FACS, Neph3+ GABAergic progenitors were sorted from the embryonic cerebellum, and the cell fate of this population was mapped by culturing in vitro. We found that most of the Neph3+ populations sorted from the mouse E12.5 cerebellum were fated to differentiate into PCs while the remaining small fraction of Neph3+ cells were progenitors for Pax2+ interneurons, which are likely to be deep cerebellar nuclei GABAergic neurons. These results were confirmed by short-term in vivo lineage-tracing experiments using transgenic mice expressing Neph3 promoter-driven GFP. In addition, we identified E-cadherin as a marker selectively expressed by a dorsally localized subset of cerebellar Neph3+ cells. Sorting experiments revealed that the Neph3+ E-cadherinhigh population in the embryonic cerebellum defined PC progenitors while progenitors for Pax2+ interneurons were enriched in the Neph3+ E-cadherinlow population. Taken together, our results identify two spatially demarcated subregions that generate distinct cerebellar GABAergic subtypes and reveal the origin of PCs in the ventricular zone of the cerebellar primordium

CCR5 Deficiency Exacerbates T-Cell–Mediated Hepatitis in Mice

Experimental T-cell–mediated hepatitis induced by concanavalin A (Con A) involves the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands (CCL3, CCL4, and CCL5) regulate leukocyte chemotaxis and activation, we investigated the role of CCR5 during Con A–induced liver injury. Serum levels of CCR5 ligands and their hepatic transcript levels were significantly increased after Con A injection, whereas CCR5+ liver mononuclear cells were recruited to the liver. CCR5-deficient (CCR5-/-) mice disclosed increased mortality and liver injury following Con A administration compared with wild-type mice. CCR5-/-mice also exhibited increased production of interleukin 4, tumor necrosis factor a CCL3, CCL4, and CCL5, and a prominent liver mononuclear cell infiltrate, among which many cells were CCR1mice also exhibited increased production of interleukin 4, tumor necrosis factor .In vivo neutralization of CCR5 ligands in CCR5-/-mice afforded a protection against hepatitis only when CCL5 was neutralized. In conclusion, CCR5 deficiency exacerbates T-cell–mediated hepatitis, and leads to increased levels of CCR5 ligands and a more pronounced liver mononuclear infiltrate, suggesting that CCR5 expression can modulate severity of immunomediated liver injury. (HEPATOLOGY 2005;42:854-862.)Journal ArticleResearch Support, Non-U.S. Gov'tFLWINinfo:eu-repo/semantics/publishe

CCR5 Deficiency Drives Enhanced Natural Killer Cell Trafficking to and Activation within the Liver in Murine T Cell-Mediated Hepatitis

Natural killer (NK) cells are innate immune cells that are enriched in the liver, but the processes underlying NK cell trafficking to the liver and cellular activation within the liver of patients with T cell-mediated liver diseases remain poorly defined. Concanavalin A (Con A) hepatitis is a murine model mimicking many aspects of human T cell-mediated liver diseases. Here we demonstrate that severe hepatitis in CCR5-deficient (KO) mice is associated with increased hepatic NK cell recruitment driven by enhanced hepatic production of CCL5 acting via CCR1 and by enhanced hepatic NK cell activation relative to that observed in wild-type mice after Con A administration. Furthermore, NK cell depletion ameliorated severe hepatitis in CCR5 KO mice but did not alter hepatitis in wild-type mice after Con A treatment. We propose that in the setting of CCR5 deficiency NK cells assume a profound effector role in Con A hepatitis via enhanced CCL5-CCR1 driven hepatic recruitment in addition to augmented cytokine-driven NK cell activation to produce interferon-γ. These results highlight the potential profound impact of altered chemokine receptor expression on the innate immune response in the setting of T cell-mediated hepatitis