Senescence-associated beta-galactosidase is lysosomal beta-galactosidase

Replicative senescence limits the proliferation of somatic cells passaged in culture and may reflect cellular aging in vivo. The most widely used biomarker for senescent and aging cells is senescence-associated beta-galactosidase (SA-beta-gal), which is defined as beta-galactosidase activity detectable at pH 6.0 in senescent cells, but the origin of SA-beta-gal and its cellular roles in senescence are not known. We demonstrate here that SA-beta-gal activity is expressed from GLB1, the gene encoding lysosomal beta-D-galactosidase, the activity of which is typically measured at acidic pH 4.5. Fibroblasts from patients with autosomal recessive G(M1)-gangliosidosis, which have defective lysosomal beta-galactosidase, did not express SA-beta-gal at late passages even though they underwent replicative senescence. In addition, late passage normal fibroblasts expressing small-hairpin interfering RNA that depleted GLB1 mRNA underwent senescence but failed to express SA-beta-gal. GLB1 mRNA depletion also prevented expression of SA-beta-gal activity in HeLa cervical carcinoma cells induced to enter a senescent state by repression of their endogenous human papillomavirus E7 oncogene. SA-beta-gal induction during senescence was due at least in part to increased expression of the lysosomal beta-galactosidase protein. These results also indicate that SA-beta-gal is not required for senescence.     

Co-administration of live attenuated Salmonella enterica serovar Typhimurium expressing swine interleukin-18 and interferon-α provides enhanced Th1-biased protective immunity against inactivated vaccine of pseudorabies virus

The co-administration of two or more cytokines may generate additive or synergistic effects for controlling infectious diseases. However, the practical use of cytokine combinations for the modulation of immune responses against inactivated vaccine has not been demonstrated in livestock yet, primarily due to protein stability, production, and costs associated with mass administration. In light of the current situation, we evaluated the immunomodulatory functions of the combined administration of swine interleukin-18 (swIL-18) and interferon-α (swIFN-α) against an inactivated PrV vaccine using attenuated Salmonella enterica serovar Typhimurium as a cytokine delivery system. Co-administration of S. enterica serovar Typhimurium expressing swIL-18 and swIFN-α produced enhanced Th1-biased humoral and cellular immune responses against the inactivated PrV vaccine, when compared to single administration of S. enterica serovar Typhimurium expressing either swIL-18 or swIFN-α. Also, enhanced immune responses in co-administered piglets occurred rapidly after virulent PrV challenge, and piglets that received co-administration of S. enterica serovar Typhimurium expressing swIL-18 and swIFN-α displayed a greater alleviation of clinical severity following the virulent PrV challenge, as determined by clinical scores and cumulative daily weight gain. Furthermore, this enhancement was confirmed by reduced nasal shedding of PrV following viral challenge. Therefore, these results suggest that oral co-administration of S. enterica serovar Typhimurium expressing swIL-18 and swIFN-α provide enhanced Th1-biased immunity against inactivated PrV vaccine to alleviate clinical signs caused by PrV challenge.     

Hypothyroid States Mitigate the Diabetes-Induced Reduction of Calbindin D-28k, Calretinin, and Parvalbumin Immunoreactivity in Type 2 Diabetic Rats

In this study, we investigated the differences in calbindin D-28k (CB), calretinin, (CR) and parvalbumin (PV) immunoreactivity in the hippocampus of Zucker diabetic fatty (ZDF) rats and Zucker lean control (ZLC) rats. In addition, we observed the effects of hypothyroidism on the levels of immunoreactivity of these proteins in ZDF rats. For this study, 7-week-old ZDF rats were used, and methimazole treatment was continued for 5 weeks to induce hypothyroidism. The animals were sacrificed at 12 weeks of age. ZDF rats showed increased blood glucose levels compared to those in ZLC rats. Methimazole intervention significantly reduced total and free T3 levels, and it ameliorated the increase of blood glucose levels in ZDF rats. In ZLC rats, CB, CR, and PV immunoreactivity was detected in regions of the hippocampus proper. In vehicle-treated ZDF rats, CB, CR, and PV immunoreactivity was significantly decreased in the hippocampus. However, in the methimazole-treated rats, CB, CR, and PV immunoreactivity was significantly increased compared to that in the vehicle-treated rats. These results suggest that hypothyroidism ameliorated the diabetes-induced reduction of CB, CR, and PV immunoreactivity in the hippocampus.     

A novel mutation in the ABCD1 gene of a Korean boy diagnosed with X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (ALD; MIM #300100) is a neurodegenerative disorder caused by mutations in the ABCD1 adrenoleukodystrophy protein gene. The ABCD1 gene mutations have been reported by laboratories in China and Japan, but not in Korea. This case report describes a Korean boy diagnosed with X-ALD. Direct sequencing for the ABCD1 gene in this boy and his mother detected Tyr620His missense mutation, caused by cDNA nucleotide change 1858 T>C in exon 8 (c.1858T>C). This missense variant was novel and predicted to be possibly damaging by the PolyPhen and SIFT prediction software. Moreover, this is the first report in Korean.