Galectin-9 (Gal-9) induced the apoptosis of not only T cell lines but also of other types of cell lines in a dose- and time-dependent manner. The apoptosis was suppressed by lactose, but not by ...sucrose, indicating that beta-galactoside binding is essential for Gal-9-induced apoptosis. Moreover, Gal-9 required at least 60 min of Gal-9 binding and possibly de novo protein synthesis to mediate the apoptosis. We also assessed the apoptosis of peripheral blood T cells by Gal-9. Apoptosis was induced in both activated CD4(+) and CD8(+) T cells, but the former were more susceptible than the latter. A pan-caspase inhibitor (Z-VAD-FMK) inhibited Gal-9-induced apoptosis. Furthermore, a caspase-1 inhibitor (Z-YVAD-FMK), but not others such as Z-IETD-FMK (caspase-8 inhibitor), Z-LEHD-FMK (caspase-9 inhibitor), and Z-AEVD-FMK (caspase-10 inhibitor), inhibited Gal-9-induced apoptosis. We also found that a calpain inhibitor (Z-LLY-FMK) suppresses Gal-9-induced apoptosis, that Gal-9 induces calcium (Ca(2+)) influx, and that either the intracellular Ca(2+) chelator BAPTA-AM or an inositol trisphosphate inhibitor 2-aminoethoxydiphenyl borate inhibits Gal-9-induced apoptosis. These results suggest that Gal-9 induces apoptosis via the Ca(2+)-calpain-caspase-1 pathway, and that Gal-9 plays a role in immunomodulation of T cell-mediated immune responses.
Importing necessary metabolites into the mitochondrial matrix is a crucial step of fuel choice during stress adaptation. Branched chain-amino acids (BCAAs) are essential amino acids needed for ...anabolic processes, but they are also imported into the mitochondria for catabolic reactions. What controls the distinct subcellular BCAA utilization during stress adaptation is insufficiently understood. The present study reports the role of SLC25A44, a recently identified mitochondrial BCAA carrier (MBC), in the regulation of mitochondrial BCAA catabolism and adaptive response to fever in rodents. We found that mitochondrial BCAA oxidation in brown adipose tissue (BAT) is significantly enhanced during fever in response to the pyrogenic mediator prostaglandin E
(PGE
) and psychological stress in mice and rats. Genetic deletion of MBC in a BAT-specific manner blunts mitochondrial BCAA oxidation and non-shivering thermogenesis following intracerebroventricular PGE
administration. At a cellular level, MBC is required for mitochondrial BCAA deamination as well as the synthesis of mitochondrial amino acids and TCA intermediates. Together, these results illuminate the role of MBC as a determinant of metabolic flexibility to mitochondrial BCAA catabolism and optimal febrile responses. This study also offers an opportunity to control fever by rewiring the subcellular BCAA fate.
•Free electron laser (FEL) destroyed aggregation of polyleucine (polyL), a polyglutamine disease-related repeat-associated non-AUG translation product.•FEL ameliorated polyL aggregates-induced low ...viability and aberrant morphology of cultured astrocytes.•FEL ameliorated polyL aggregates-induced loss of cerebellar Purkinje cells in mice.
Polyglutamine (polyQ) diseases are devastating neurological disorders that cannot be effectively treated. Repeat-associated non-AUG (RAN) translation has been documented in transcripts in polyQ diseases. RAN products include proteins with polyleucine (polyL) tracts. Similar to polyQ, polyL tends to aggregate, which is toxic to cells and mice. Irradiation with a free electron laser (FEL) tuned at mid-infrared wavelengths can dissociate polyQ aggregates in cultured cells. However, whether FEL dissociates the polyL is unclear. It is also unclear whether brain dysfunction caused by polyL aggregates in mice can be ameliorated by FEL irradiated polyL. Here, we show that FEL at approximately 6 μm can destroy polyL aggregates, as evidenced by scanning electron microscopy, atomic force microscopy, and dot blot analyses. Although polyL aggregates induced low viability and aberrant morphology of cultured astrocytes, FEL irradiated polyL exhibited mild defects. Likewise, the toxicity of polyL-containing microglia in vitro was ameliorated by FEL irradiation. In vivo, mice administered polyL aggregates in the cerebellum induced loss of Purkinje cells, which was ameliorated when FEL irradiated polyL was injected. These results justify the clearing of aggregates by approaches using molecular chaperones, laser irradiation, and ultrasound as a general therapeutic strategy to correct brain dysfunction by the RAN products.
Display omitted
Fever is induced by a neuronal mechanism in the brain. Prostaglandin (PG) E2 acts as a pyrogenic mediator in the preoptic area (POA) probably through the EP3 subtype of PGE receptor expressed on ...GABAergic neurons, and this PGE2 action triggers neuronal pathways for sympathetic thermogenesis in peripheral effector organs including brown adipose tissue (BAT). To explore pyrogenic efferent pathways from the POA, we determined projection targets of EP3 receptor‐expressing POA neurons with a special focus on rat hypothalamic regions including the dorsomedial hypothalamic nucleus (DMH), which is known as a center for autonomic responses to stress. Among injections of cholera toxin b‐subunit (CTb), a retrograde tracer, into hypothalamic regions at the rostrocaudal level of the DMH, injections into the DMH, lateral hypothalamic area (LH) and dorsal hypothalamic area (DH) resulted in EP3 receptor immunolabelling in substantial populations of CTb‐labeled neurons in the POA. Bilateral microinjections of muscimol, a GABAA receptor agonist, into the DMH and a ventral region of the DH, but not those into the LH, inhibited thermogenic (BAT sympathetic nerve activity, BAT temperature, core body temperature and expired CO2) and cardiovascular (arterial pressure and heart rate) responses to an intra‐POA PGE2 microinjection. Further immunohistochemical observations revealed a close association of POA‐derived GABAergic axon swellings with DMH neurons projecting to the medullary raphe regions where sympathetic premotor neurons for febrile and thermoregulatory responses are localized. These results suggest that a direct projection of EP3 receptor‐expressing POA neurons to the DMH/DH region mediates febrile responses via a GABAergic mechanism.
Highly aligned and isolated single-walled carbon nanotubes (SWNTs) were grown on the R-face
(
1
1
¯
0
2
)
and A-face
(
1
1
2
¯
0
)
surfaces of sapphire (Al
2O
3) substrates by catalytic chemical ...vapor deposition. On the basis of the electron backscatter diffraction (EBSD) analysis, we have found that the SWNTs are aligned along the specific crystalline directions corresponding to the anisotropic pseudo-one-dimensional array of Al atoms on these surfaces. This suggests that the Al array guides the SWNT growth due to the strong interaction between the Al atoms and nanotubes. On the other hand, a random orientation has been observed for the SWNTs grown on the C-face (0
0
0
1) substrate, reflecting the isotropic arrangement of Al atoms. These findings indicate that the strong interaction between the SWNTs and substrate surface is applicable for patterning or integrating SWNTs in nanoelectronics applications.
The generation of pyramidal neurons in the mammalian neocortex has been attributed to proliferating progenitor cells within the ventricular zone (VZ). Recently, the subventricular zone (SVZ) has been ...recognized as a possible source of migratory neurons in brain slice preparations, but the relevance of these observations for the developing neocortex in vivo remains to be defined. Here, we demonstrate that a subset of progenitor cells within the SVZ of the mouse neocortex can be molecularly defined by Cre recombinase expression under control of the NEX/Math2 locus, a neuronal basic helix-loop-helix gene that by itself is dispensable for cortical development. NEX-positive progenitors are generated by VZ cells, move into the SVZ, and undergo multiple asymmetrical and symmetrical cell divisions that produce a fraction of the neurons in the upper cortical layers. Our data suggest that NEX-positive progenitors within the SVZ are committed to a glutamatergic neuronal fate and have evolved to expand the number of cortical output neurons that is characteristic for the mammalian forebrain.
Heterozygosity for dominant-negative STAT1 mutations underlies autosomal dominant Mendelian susceptibility to mycobacterial diseases. Mutations conferring Mendelian susceptibility to mycobacterial ...diseases have been identified in the regions of the STAT1 gene encoding the tail segment, DNA-binding domain and SH2 domain. We describe here a new heterozygous mutation, Y701C, in a Japanese two-generation multiplex kindred with autosomal dominant Mendelian susceptibility to mycobacterial diseases. This mutation affects precisely the canonical STAT1 tyrosine phosphorylation site. The Y701C STAT1 protein is produced normally, but its phosphorylation is abolished, resulting in a loss-of-function for STAT1-dependent cellular responses to interferon-γ or interferon-α. In the patients' cells, the allele is dominant-negative for γ-activated factor-mediated responses to interferon-γ, but not for interferon-stimulated gene factor-3-mediated responses to interferon-α/β, accounting for the clinical phenotype of Mendelian susceptibility to mycobacterial diseases without severe viral diseases. Interestingly, both patients displayed multifocal osteomyelitis, which is often seen in patients with Mendelian susceptibility to mycobacterial diseases with autosomal dominant partial IFN-γR1 deficiency. Multifocal osteomyelitis should thus prompt investigations of both STAT1 and IFN-γR1. This experiment of nature also confirms the essential role of tyrosine 701 in human STAT1 activity in natura.
PDF
