Recent identification of cancer stem cells in medulloblastoma (MB) and high-grade glioma has stimulated an urgent need for animal models that will not only replicate the biology of these tumors, but also preserve their cancer stem cell pool. We hypothesize that direct injection of fresh surgical specimen of MB and high-grade glioma tissues into anatomically equivalent locations in immune-deficient mouse brains will facilitate the formation of clinically accurate xenograft tumors by allowing brain tumor stem cells, together with their non-stem tumor and stromal cells, to grow in a microenvironment that is the closest to human brains. Eight of the 14 MBs (57.1%) and two of the three high-grade gliomas (66.7%) in this study developed transplantable (up to 12 passages) xenografts in mouse cerebellum and cerebrum, respectively. These xenografts are patient specific, replicating the histopathologic, immunophenotypic, invasive/metastatic, and major genetic (analyzed with 10K single nucleotide polymorphism array) abnormalities of the original tumors. The xenograft tumor cells have also been successfully cryopreserved for long-term preservation of tumorigenicity, ensuring a sustained supply of the animal models. More importantly, the CD133 ؉ tumor cells, ranging from 0.2%-10.4%, were preserved in all the xenograft models following repeated orthotopic subtransplantations in vivo. The isolated CD133؉ tumor cells formed neurospheres and displayed multi-lineage differentiation capabilities in vitro. In summary, our study demonstrates that direct orthotopic transplantation of fresh primary tumor cells is a powerful approach in developing novel clinical relevant animal models that can reliably preserve CD133 ؉ tumor cell pools even during serial in vivo subtransplantations. STEM
Diabetic nephropathy manifests aberrant activation of TORC1, which senses key signals to modulate protein synthesis and renal hypertrophy. PRAS40 has recently been identified as a raptor-interacting protein and is a component and a constitutive inhibitor of TORC1. The mechanism by which high glucose stimulates TORC1 activity is not known. PRAS40 was identified in the mesangial cells in renal glomeruli and in tubulointerstitium of rat kidney. Streptozotocin-induced diabetic renal hypertrophy was associated with phosphorylation of PRAS40 in the cortex and glomeruli. In vitro, high glucose concentration increased PRAS40 phosphorylation in a PI 3 kinase-and Akt-dependent manner, resulting in dissociation of raptor-PRAS40 complex in mesangial cells. High glucose augmented the inactivating and activating phosphorylation of 4EBP-1 and S6 kinase, respectively with concomitant induction of protein synthesis and hypertrophy. Expression of TORC1-nonphosphorylatable mutant of 4EBP-1 and dominant negative S6 kinase significantly inhibited high glucose-induced protein synthesis and hypertrophy. PRAS40 knockdown mimicked the effect of high glucose on phosphorylation of 4EBP-1 and S6 kinase, protein synthesis and hypertrophy. To elucidate the role of PRAS40 phosphorylation, we used phosphorylation-deficient mutant of PRAS40, which in contrast to PRAS40 knockdown inhibited phosphorylation of 4EBP-1 and S6 kinase, leading to reduced mesangial cell hypertrophy. Thus our data identify high glucose-induced phosphorylation and inactivation of PRAS40 as a central node for mesangial cell hypertrophy in diabetic nephropathy.
Purpose: To evaluate effects on growth and infection rates of supplementing infant formula with the probiotic Lactobacillus paracasei ssp. paracasei strain F19 (F19) or bovine milk fat globule membrane (MFGM).Methods: In a double-blind, randomized controlled trial, 600 infants were randomized to a formula supplemented with F19 or MFGM, or to standard formula (SF). A breastfed group was recruited as reference (n = 200).The intervention lasted from age 21 ± 7 days until 4 months, and infants were followed until age one year.Results: Both experimental formulas were well tolerated and resulted in high compliance. The few reported adverse events were not likely related to formula, with the highest rates in the SF group, significantly higher than for the F19-supplemented infants (p = 0.046). Weight or length gain did not differ during or after the intervention among the formula-fed groups, with satisfactory growth. During the intervention, overall, the experimental formula groups did not have more episodes of diarrhea, fever, or days with fever than the breastfed infants. However, compared to the breastfed infants, the SF group had more fever episodes (p = 0.021) and days with fever (p = 0.036), but not diarrhea. Compared with the breastfed group, the F19-supplemented infants but not the other two formula groups had more visits/unscheduled hospitalizations (p = 0.015) and borderline more episodes of upper respiratory tract infections (p = 0.048).Conclusions: Both the MFGM- and F19-supplemented formulas were safe and well-tolerated, leading to few adverse effects, similar to the breastfed group and unlike the SF group. During the intervention, the MFGM-supplemented infants did not differ from the breastfed infants in any primary outcome.
Preterm birth is a major health issue. As part of their life-saving care, most preterm infants require hospitalization and are inevitably exposed to repetitive skin-breaking procedures. The long-term effects of neonatal repetitive pain on cognitive and emotional behaviors involving hypothalamic-pituitary-adrenal (HPA) axis function in young and adult rats are unknown. From P8 to P85, mechanical hypersensitivity of the bilateral hindpaws was observed in the Needle group (P < 0.001). Compared with the Tactile group, the Needle group took longer to find the platform on P30 than on P29 (P = 0.03), with a decreased number of original platform site crossings during the probe trial of the Morris water maze test (P = 0.026). Moreover, the Needle group spent more time and took longer distances in the central area than the Tactile group in the Open-field test, both in prepubertal and adult rats (P < 0.05). The HPA axis function in the Needle group differed from the Tactile group (P < 0.05), with decreased stress responsiveness in prepuberty and puberty (P < 0.05) and increased stress responsiveness in adulthood (P < 0.05). This study indicates that repetitive pain that occurs during a critical period may cause severe consequences, with behavioral and neuroendocrine disturbances developing through prepuberty to adult life.
Epilepsy is one of the most common chronic neurological diseases. High-frequency oscillations (HFOs) have emerged as promising biomarkers for the epileptogenic zone. However, visual marking of HFOs is a time-consuming and laborious process. Several automated techniques have been proposed to detect HFOs, yet these are still far from being suitable for application in a clinical setting. Here, ripples and fast ripples from intracranial electroencephalograms were detected in six patients with intractable epilepsy using a convolutional neural network (CNN) method. This approach proved more accurate than using four other HFO detectors integrated in RIPPLELAB, providing a higher sensitivity (77.04% for ripples and 83.23% for fast ripples) and specificity (72.27% for ripples and 79.36% for fast ripples) for HFO detection. Furthermore, for one patient, the Cohen's kappa coefficients comparing automated detection and visual analysis results were 0.541 for ripples and 0.777 for fast ripples. Hence, our automated detector was capable of reliable estimates of ripples and fast ripples with higher sensitivity and specificity than four other HFO detectors. Our detector may be used to assist clinicians in locating epileptogenic zone in the future.
Obesity is one of the largest health problems facing the world today. Although twin and family studies suggest about two-thirds of obesity is caused by genetic factors, only a small fraction of this variance has been unraveled. There are still large numbers of genes to be identified that cause variations in body fatness and the associated diseases encompassed in the metabolic syndrome (MetS). A locus near a sequence tagged site (STS) marker D6S1009 has been linked to obesity or body mass index (BMI). However, its genetic entity is unknown. D6S1009 is located in the intergenic region between SLC35D3 and NHEG1. Here we report that the ros mutant mice harboring a recessive mutation in the Slc35d3 gene show obesity and MetS and reduced membrane dopamine receptor D1 (D1R) with impaired dopamine signaling in striatal neurons. SLC35D3 is localized to both endoplasmic reticulum (ER) and early endosomes and interacts with D1R. In ros striatal D1 neurons, lack of SLC35D3 causes the accumulation of D1R on the ER to impair its ER exit. The MetS phenotype is reversible by the administration of D1R agonist to the ros mutant. In addition, we identified two mutations in the SLC35D3 gene in patients with MetS, which alter the subcellular localization of SLC35D3. Our results suggest that the SLC35D3 gene, close to the D6S1009 locus, is a candidate gene for MetS, which is involved in metabolic control in the central nervous system by regulating dopamine signaling.
Aim: To determine the relationship between six-transmembrane epithelial antigen of the prostate 4 (STEAP4) expression and obesity. Methods: RT-PCR and immunoblot analyses were performed to determine the differential expressions of STEAP4 mRNA and protein, respectively, in human omental adipose tissue from obese patients and normal weight controls. The expression pattern of STEAP4 mRNA in various human tissues was determined by RT-PCR. The subcellular localization of the STEAP4 protein in human adipose tissue was confirmed by immunohistochemistry. Finally, we confirmed that cultured human omental adipose tissue undergoes TNF-α-mediated regulation of the STEAP4 expression. Results: STEAP4 mRNA and protein levels were downregulated in omental adipose tissue from obese patients relative to normal controls. The STEAP4 expression was most abundant in human adipose tissue. An immunohistochemical analysis confirmed that STEAP4 was associated with the plasma membrane of adipocytes. The STEAP4 expression was induced by TNF-α in a dose-dependent manner in human adipose tissue. Conclusion: STEAP4 was abundantly expressed in human adipose tissue, and the STEAP4 expression was significantly downregulated in obese patients. STEAP4 localized to the plasma membrane of adipocytes, and the STEAP4 expression was induced by TNF-α in adipose tissue. These data suggest that STEAP4 may play a significant role in the development of human obesity. Key wordssix-transmembrane epithelial antigen of the prostate 4; obesity; tumor necrosis factor-α;
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