Astrocyte activation is suppressed in both normal and injured brain by FGF signaling.

In the brain, astrocytes are multifunctional cells that react to insults and contain damage. However, excessive or sustained reactive astrocytes can be deleterious to functional recovery or contribute to chronic inflammation and neuronal dysfunction. Therefore, astrocyte activation in response to damage is likely to be tightly regulated.

Tanycytes of the hypothalamic median eminence form a diet-responsive neurogenic niche.

Adult hypothalamic neurogenesis has recently been reported, but the cell of origin and the function of these newborn neurons are unknown. Using genetic fate mapping, we found that median eminence tanycytes generate newborn neurons. Blocking this neurogenesis altered the weight and metabolic activity of adult mice.

Genetic approaches identify adult pituitary stem cells.

Adult tissues undergo continuous cell turnover in response to stress, damage, or physiological demand. New differentiated cells are generated from dedicated or facultative stem cells or from self-renewing differentiated cells. Here we describe a different stem cell strategy for tissue maintenance, distinct from that observed for dedicated or facultative stem cells.

Mosaic removal of hedgehog signaling in the adult SVZ reveals that the residual wild-type stem cells have a limited capacity for self-renewal.

The Smoothened gene is necessary for cells to transduce hedgehog signaling. Although we and others have previously shown that embryonic removal of Smoothened in the neural tube results in a loss of stem cells from the postnatal subventricular zone, it was unclear whether this reflected a requirement for hedgehog signaling in the establishment or maintenance of the adult niche. Here, we have examined the consequences of conditional removal of Smoothened gene function within the subventricular zone of the adult neural stem cell niche.

Hedgehog signaling in the subventricular zone is required for both the maintenance of stem cells and the migration of newborn neurons.

We examined the postnatal consequences of removing Hedgehog signaling within the adult stem cell niche. Although at birth the subventricular zone appears normal in mice lacking Hedgehog signaling, by postnatal day 8 it is greatly impaired, and cell death is increased. In addition, both the quiescent B stem cell population and transit-amplifying C cells become depleted postnatally.

Differential regulation of Notch signal transduction in leukaemia and lymphoma cells in culture.

The transduction of Notch signal plays an intricate role in cell differentiation and pathogenesis of haematological malignancies as well as in certain congenital conditions. We found no genomic changes in either gene in 34 leukaemic samples and 25 leukaemia and lymphoma cell lines. The functionality of Notch signalling was tested using HES1 gene activation.

Allele frequency of two intragenic microsatellite loci of SEL1L gene in Northern Italian population.

Two cytosine-adenine (CA) repeats CAR/CAL and RepIN20 occur in the human SEL1L gene, which is regarded as a candidate gene for insulin-dependent diabetes mellitus (IDDM) and Grave's disease. We have characterized these repeats to determine if they might serve as effective microsatellite markers for linkage analysis to clarify whether SEL1L gene plays a role in the pathogenesis of these autoimmune diseases. The allele frequencies and average heterozygosity of the microsatellite repeats were analysed in 94 DNA samples from peripheral blood mononuclear (PBMC) cells from adults of Northern Italy.