GM1-gangliosidosis in American black bears: clinical, pathological, biochemical and molecular genetic characterization.

G(M1)-gangliosidosis is a rare progressive neurodegenerative disorder due to an autosomal recessively inherited deficiency of lysosomal ß-galactosidase. We have identified seven American black bears (Ursus americanus) found in the Northeast United States suffering from G(M1)-gangliosidosis. This report describes the clinical features, brain MRI, and morphologic, biochemical and molecular genetic findings in the affected bears. Brain lipids were compared with those in the brain of a G(M1)-mouse. The bears presented at ages 10-14 months in poor clinical condition, lethargic, tremulous and ataxic. They continued to decline and were humanely euthanized. The T(2)-weighted MR images of the brain of one bear disclosed white matter hyperintensity. Morphological studies of the brain from five of the bears revealed enlarged neurons with foamy cytoplasm containing granules. Axonal spheroids were present in white matter. Electron microscopic examination revealed lamellated membrane structures within neurons. Cytoplasmic vacuoles were found in the liver, kidneys and chondrocytes and foamy macrophages within the lungs. Acid ß-galactosidase activity in cultured skin fibroblasts was only 1-2% of control values. In the brain, ganglioside-bound sialic acid was increased more than 2-fold with G(M1)-ganglioside predominating. G(A1) content was also increased whereas cerebrosides and sulfatides were markedly decreased. The distribution of gangliosides was similar to that in the G(M1)-mouse brain, but the loss of myelin lipids was greater in the brain of the affected bear than in the brain of the G(M1) mouse. Isolated full-length cDNA of the black bear GLB1 gene revealed 86% homology to its human counterpart in nucleotide sequence and 82% in amino acid sequence. GLB1 cDNA from liver tissue of an affected bear contained a homozygous recessive T(1042) to C transition inducing a Tyr348 to His mutation (Y348H) within a highly conserved region of the GLB1 gene. The coincidence of several black bears with G(M1)-gangliosidosis in the same geographic area suggests increased frequency of a founder mutation in this animal population.

[Recombinant human tumor necrosis factor-alpha promotes human adipose-derived stromal cells transforming into osteoblast in vitro].

OBJECTIVE: To investigate the effect of recombinant human tumor necrosis factor alpha (rhTNF-α) on the osteogenesis potential of the osteo-induced human adipose-derived stromal cells (hASCs) in vitro. METHODS: hASCs at passage 4 were divided into four groups according to culturing conditions: basal medium [BM, DMEM + 10% FBS + antibiotics], BM with 10 µg/L rhTNF-α, osteogenic medium (OM, BM + dexamethasone + L-ascorbate + ß-glycerophosphate) and OM with 10 µg/L rhTNF-α. On days 3, 7, 14 and 21, alkaline phosphatase (ALP) activities were examined. On days 14 and 21, the staining and quantitation of calcium deposition were performed. For the cells under osteogenic induction, osteoblast-related genes, such as core-binding factor α1 (Cbfa1), Osterix (Osx) and osteocalcin (OC) were analyzed with reverse transcription PCR on days 3, 7, 14, and 21, and real time PCR was performed to confirm the effect of rhTNF-α on genes expression on day 3 . RESULTS: rhTNF-α promoted ALP activities of induced hASCs on day 14 (3.527 ± 0.415 vs. 2.345 ± 0.354,P<0.01) and on day 21 (3.106 ± 0.105 vs. 2.442 ± 0.163,P<0.01) and promoted calcium deposition of induced hASCs on day 14 (2.896 ± 0.173 vs. 0.679 ± 0.173,P<0.01) and on day 21 (2.231 ± 0.233 vs. 1.729 ± 0.229, P<0.01). RT-PCR and Real-time PCR assays showed that rhTNF-α augmented the expression of Cbfa1, Osx and OC of these cells. CONCLUSION: The findings indicate that 10 µg/L rhTNF-α can promote the osteogenic potential of osteogenetically induced hASCs in vitro.

[Application of human adipose-derived stromal cells in bone tissue engineering].

Human adipose-derived stromal cells (hASCs) can be obtained from adipose tissues that offer an abundant and easily accessible pool of stem cells. Thus, hASCs have become a highly attractive source of seed cells in bone tissue engineering and have promising prospects in bone regeneration. Since 2002, our research group has performed a series of experiments on hASCs and its application in bone tissue engineering, including: to substitute dexamethasone by 1,25 (OH)2 vitamin D3 to induce osteogenic differentiation of hASCs; to explore the effect of epigenetic regulation and to inflammation on the osteogenic differentiation of hASCs; to construct a novel and simple tissue engineered bone system by hASCs and human platelet-rich plasma (hPRP) and to investigate the bone formation capability of this tissue engineered bone and the stimulatory effect of simvastatin. Our results suggested that 1,25 (OH)2 vitamin D3 could replace dexamethasone to induce the osteogenic differentiation of hASCs; retinoblastoma binding protein 2 (RBP2), as one of histone demethylases, could regulate the osteogenic differentiation of hASCs epigenetically while tumor necrosis factor α (TNFα), as a inflammatory factor, could also influence the osteogenic differentiation of hASCs. Moreover, we found that in vivo bone formation could be detected by our novel tissue engineered bone composed with hASCs and hPRP; simvastatin could enhance the bone formation capability of this tissue-engineered structure.

Tay-Sachs disease in Jacob sheep.

Autopsy studies of four Jacob sheep dying within their first 6-8 months of a progressive neurodegenerative disorder suggested the presence of a neuronal storage disease. Lysosomal enzyme studies of brain and liver from an affected animal revealed diminished activity of hexosaminidase A (Hex A) measured with an artificial substrate specific for this component of ß-hexosaminidase. Absence of Hex A activity was confirmed by cellulose acetate electrophoresis. Brain lipid analyses demonstrated the presence of increased concentrations of G(M2)-ganglioside and asialo-G(M2)-ganglioside. The hexa cDNA of Jacob sheep was cloned and sequenced revealing an identical number of nucleotides and exons as in human HexA and 86% homology in nucleotide sequence. A missense mutation was found in the hexa cDNA of the affected sheep caused by a single nucleotide change at the end of exon 11 resulting in skipping of exon 11. Transfection of normal sheep hexa cDNA into COS1 cells and human Hex A-deficient cells led to expression of Hex S but no increase in Hex A indicating absence of cross-species dimerization of sheep Hex α-subunit with human Hex ß-subunits. Using restriction site analysis, the heterozygote frequency of this mutation in Jacob sheep was determined in three geographically separate flocks to average 14%. This large naturally occurring animal model of Tay-Sachs disease is the first to offer promise as a means for trials of gene therapy applicable to human infants.

[Effects of rhTNF-alpha on the secretion of angiogenesis-related growth factors of human adipose tissue-derived stromal cells before and after osteogenic differentiation].

OBJECTIVE: To investigate the proliferation and the secretion of vascular endothelial growth factor(VEGF), fibroblast growth factor-2(FGF-2) and insulin-like growth factor-1(IGF-1) of human adipose tissue-derived stromal cells(hADSCs) before and after osteogenic differentiation under the stimuli of recombinant human tumor necrosis factor alpha (rhTNF-alpha). METHODS: hADSCs were obtained from human lipoaspirates. All the cells used were at passage four. The proliferation of hADSCs was measured with MTT assays 48, 72, 96 hours after being treated with 0, 1, 5, 10, 50 or 100 microg/L rhTNF-alpha respectively. The secretion of VEGF, FGF-2 and IGF-1 of the undifferentiated hADSCs under stimuli of rhTNF-alpha with the above 5 concentration grades was observed and the secretion of these 3 growth factors of hADSCs at different stages of osteogenic differentiation under stimuli of 10 microg/L rhTNF-alpha was also observed. All the supernatants were harvested for measuring after 24 hours' incubation with rhTNF-alpha. The secretion of VEGF, FGF-2 and IGF-1 was measured with ELISA, and the values were normalized to the cell number of the corresponding wells. RESULTS: The effect of rhTNF-alpha on the proliferation of hADSCs varied with the concentration and time. Compared with the control(0 microg/L), 10 microg/L rhTNF-alpha showed no suppression or acceleration on proliferation of hADSCs at hour 48, but significantly promoted the proliferation at hour 96 (0.903+/-0.042 vs 0.810+/-0.011, P<0.01), 100 microg/L rhTNF-alpha seemed to suppress the proliferation at hour 48 (0.317+/-0.024 vs 0.458+/-0.046, P<0.01), but appeared to promote it (0.956+/-0.030 vs 0.810+/-0.011, P<0.01) at hour 96. rhTNF-alpha(1, 5, 10, 50 and 100 microg/L) significantly increased VEGF, FGF-2 and IGF-1 production of hADSCs versus the control (0 microg/L) (P<0.01). After osteogenic differention, the secretion of the three growth factors of hADSCs (without rhTNF-alpha treated) was elevated with the days increasing. Under the stimulus of 10 microg/L rhTNF-alpha, the hADSCs after 1 day of osteogenic differentiation significantly increased the secretion of VEGF (P<0.01) compared with the group without rhTNF-alpha treated; after 3 and 7 days of osteogenic differentiation, the hADSCs significantly increased the secretion of VEGF (P<0.01), FGF-2 (P<0.05)and IGF-1 (P<0.05). However, after 14 days of osteogenic differentiation, 10 microg/L rhTNF-alpha appeared to suppress the production of VEGF (P<0.01), FGF-2 (P<0.05) and IGF-1 (P<0.05) of the differentiated hADSCs. CONCLUSION: Within certain concentration range, rhTNF-alpha can promote the proliferation of hADSCs and the production of VEGF, FGF-2 and IGF-1. The effect of 10 microg/L rhTNF-alpha on the production of VEGF, FGF-2 and IGF-1 of the differentiated hADSCs varied at different stages of osteogenic differentiation.

[Comparison of biological characteristics of human, rabbit and rat adipose tissue-derived stromal cells in vitro].

OBJECTIVE: This study aims to investigate the difference of proliferation patterns and osteogenic and adipogenic differentiation capability of adipose-derived stromal cells (ADSCs) obtained from human lipoaspirates, rat and rabbit inguinal subcutaneous adipose tissues in vitro. METHODS: Adipose tissues of healthy adults were obtained by liposuction. Human ADSCs were isolated from these adipose tissues and cultured in DMEM containing 10% fetal bovine serum (FBS). Rat and rabbit ADSCs were obtained from inguinal subcutaneous adipose tissues and cultured with the same methods. These cells were observed under inverted microscope each day and cell growth was measured with MTT assay. Adipogenic differentiation was induced by culturing ADSCs for 1 or 2 weeks in adipogenic medium (AM) containing 1 micromol/L dexamethasone, 10 micromol/L insulin, 200 micromol/L indomethacin, 0.5 mmol/L isobutyl-methylxanthine (IBMX), and assessed by Oil Red O staining as an indicator of intracellular lipid accumulation. Osteogenic differentiation was induced by culturing ADSCs in osteogenic medium (OM) containing 0.1 micromol/L dexamethasone, 50 micromol/L ascorbate-2-phosphate, 10 mmol/L beta-glycerophosphate, and examined via alkaline phosphatase (AP) activity and extracellular matrix (ECM) calcification by alizarin red S staining and quantification of matrix calcification. RESULTS: Fibroblast-like cells were digested from both inguinal subcutaneous adipose tissues of rabbit or rat and human lipoaspirates obtained from subcutaneous adipose tissues. Lipid-filled droplets were accumulated in human, rat and rabbit ADSCs upon treatment with adipogenic medium and were stained by Oil Red O. No lipid droplets were observed in the control undifferentiated ADSCs. After exposure to osteogenic differentiation medium, human and rat ADSCs were found to possess greater osteogenic potentials than cells isolated from rabbit inguinal subcutaneous adipose tissues, which was evidenced by significantly different osteogenic markers including alkaline phosphatase and mineral deposition. CONCLUSION: Rabbit ADSCs obtained from inguinal subcutaneous adipose tissues poorly possess osteogenic potentials compared with ADSCs of human lipoaspirates obtained from subcutaneous adipose tissues or ADSCs of rat from inguinal subcutaneous adipose tissues, although they all possess comparable adipogenic capacity.

Mild-onset presentation of Canavan's disease associated with novel G212A point mutation in aspartoacylase gene.

We describe two sisters with a mild-onset variant of Canavan's disease who presented at age 50 and 19 months with developmental delay but without macrocephaly, hypotonia, spasticity, or seizures. Remarkably, both patients had age-appropriate head control, gross motor development, and muscle tone. There were very mild deficits in fine motor skills, coordination, and gait. Both sisters had a history of strabismus, but otherwise vision was normal. The older child showed evidence of mild cognitive and social impairment, whereas language and behavior were normal for age in the infant. Both patients were found to be compound heterozygotes for C914A (A305E) and G212A (R71H) mutations in ASPA. Like all other known ASPA mutations, this previously unknown G212A mutation appears to have low absolute enzyme activity. Nevertheless, it is associated in these patients with an extremely benign phenotype that is highly atypical of Canavan's disease. Biochemical and clinical data were evaluated using a generalized linear mixed model generated from 25 other subjects with Canavan's disease. There were statistically significant differences in brain chemistry and clinical evaluations, supporting a distinct variant of Canavan's disease. Future studies of ASPA enzyme structure and gene regulation in these subjects could lead to a better understanding of Canavan's pathophysiology and improvements in ASPA gene therapy.