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1مورد إلكتروني
المصدر: Department of Pathology, Anatomy, and Cell Biology Faculty Papers
مستخلص: BACKGROUND: Preclinical and clinical studies have previously shown that systemic administration of GM1 ganglioside has neuroprotective and neurorestorative properties in Parkinson's disease (PD) models and in PD patients. However, the clinical development of GM1 for PD has been hampered by its animal origin (GM1 used in previous studies was extracted from bovine brains), limited bioavailability, and limited blood brain barrier penetrance following systemic administration. OBJECTIVE: To assess an alternative therapeutic approach to systemic administration of brain-derived GM1 to enhance GM1 levels in the brain via enzymatic conversion of polysialogangliosides into GM1 and to assess the neuroprotective potential of this approach. METHODS: We used sialidase from Vibrio cholerae (VCS) to convert GD1a, GD1b and GT1b gangliosides to GM1. VCS was infused by osmotic minipump into the dorsal third ventricle in mice over a 4-week period. After the first week of infusion, animals received MPTP injections (20 mg/kg, s.c., twice daily, 4 hours apart, for 5 consecutive days) and were euthanized 2 weeks after the last injection. RESULTS: VCS infusion resulted in the expected change in ganglioside expression with a significant increase in GM1 levels. VCS-treated animals showed significant sparing of striatal dopamine (DA) levels and substantia nigra DA neurons following MPTP administration, with the extent of sparing of DA neurons similar to that achieved with systemic GM1 administration. CONCLUSION: The results suggest that enzymatic conversion of polysialogangliosides to GM1 may be a viable treatment strategy for increasing GM1 levels in the brain and exerting a neuroprotective effect on the damaged nigrostriatal DA system.
مصطلحات الفهرس: Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University; animal cell; animal experiment; animal model; animal tissue; Article; brain third ventricle; chemical modification; controlled study; corpus striatum; dopamine brain level; dopaminergic nerve cell; drug infusion; drug mechanism; enzyme activity; male; mouse; neuroprotection; nonhuman; osmotic minipump; Parkinson disease; substantia nigra; systemic therapy; treatment duration; treatment response; Vibrio cholerae, Pathology, article
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2مورد إلكتروني
المصدر: Department of Microbiology and Immunology Faculty Papers
مستخلص: Cytomegalovirus (CMV) is a herpesvirus that persists for life and maintains extremely large numbers of T cells with select specificities in circulation. However, it is unknown how viral persistence impacts T cell populations in mucosal sites. We found that many murine (M)CMV-specific CD8s in mucosal tissues became resident memory T cells (TRM). These cells adopted an intraepithelial localization in the salivary gland that correlated with, but did not depend on, expression of the integrin CD103. MCMV-specific TRM cells formed early after infection, and spleen-localized cells had reduced capacities to become TRM at late times. Surprisingly, however, small numbers of new TRM cells were formed from the circulating pool throughout infection, favoring populations maintained at high levels in the blood and shifting the immunodominance within the TRM populations over time. These data show that mucosal TRM populations can be dynamically maintained by a persistent infection.
مصطلحات الفهرس: Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University; animal cell; animal experiment; animal model; animal tissue; antigen expression; Article; CD8+ T lymphocyte; cellular distribution; controlled study; Cytomegalovirus; cytomegalovirus infection; female; lymphocyte differentiation; memory T lymphocyte; mouse; mucosal immunity; nonhuman; priority journal; salivary gland; steady state; T lymphocyte subpopulation; upregulation; virus replication, Medical Immunology, article
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3مورد إلكتروني
المصدر: Department of Pathology, Anatomy, and Cell Biology Faculty Papers
مستخلص: Pancreatic ductal adenocarcinoma (PDA) harbors an exceedingly poor prognosis, and is generally considered a therapy-recalcitrant disease due to poor response to conventional chemotherapy coupled with non-actionable genetic drivers (e.g. KRAS mutations). However, PDA frequently loses p16ink4a, thereby leading to deregulation of CDK4/6. Surprisingly, in established cell models and xenografts, CDK4/6 inhibition has a modest effect on proliferation and resistance develops rapidly. To determine if such weak response was an intrinsic feature of PDA, we developed primary tumor explants that maintain the tumor environment and recapitulate feuture of primary PDA. The CDK4/6 inhibitor PD-0332991 was highly efficient at suppressing proliferation in 14 of the 15 explants. In the single resistant explant, we identified the rare loss of the RB tumor suppressor as the basis for resistance. Patient-derived xenografts (PDXs) were developed in parallel, and unlike the xenografts emerging from established cell lines, the PDXs maintained the histoarchitecture of the primary tumor. These PDXs were highly sensitive to CDK4/6 inhibition, yielding a complete suppression of PDA proliferation. Together, these data indicate that primary PDA is sensitive to CDK4/6 inhibition, that specific biomarkers can delineate intrinsic resistance, and that established cell line models may not represent an adequate means for evaluating therapeutic sensitivities.
مصطلحات الفهرس: Department of Surgery, Department of Pathology, Thomas Jefferson University; animal experiment; animal model; animal tissue; Article; cell proliferation; cohort analysis; controlled study; enzyme inhibition; enzyme repression; human; in vitro study; in vivo study; mouse; nonhuman; pancreas cancer; pathogenesis; tumor microenvironment; tumor xenograft, Oncology, article
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4مورد إلكتروني
المصدر: Department of Cancer Biology Faculty Papers
مستخلص: Cyclin D1 is an important molecular driver of human breast cancer but better understanding of its oncogenic mechanisms is needed, especially to enhance efforts in targeted therapeutics. Currently, pharmaceutical initiatives to inhibit cyclin D1 are focused on the catalytic component since the transforming capacity is thought to reside in the cyclin D1/CDK activity. We initiated the following study to directly test the oncogenic potential of catalytically inactive cyclin D1 in an in vivo mouse model that is relevant to breast cancer. Herein, transduction of cyclin D1-/- mouse embryonic fibroblasts (MEFs) with the kinase dead KE mutant of cyclin D1 led to aneuploidy, abnormalities in mitotic spindle formation, autosome amplification, and chromosomal instability (CIN) by gene expression profiling. Acute transgenic expression of either cyclin D1WT or cyclin D1KE in the mammary gland was sufficient to induce a high CIN score within 7 days. Sustained expression of cyclin D1KE induced mammary adenocarcinoma with similar kinetics to that of the wild-type cyclin D1. ChIP-Seq studies demonstrated recruitment of cyclin D1WT and cyclin D1KE to the genes governing CIN. We conclude that the CDK-activating function of cyclin D1 is not necessary to induce either chromosomal instability or mammary tumorigenesis.
مصطلحات الفهرس: Sidney Kimmel Cancer Center; Medical Oncology, Departments of Cancer Biology, Thomas Jefferson University and Hospital; aneuploidy; animal cell; animal experiment; animal model; animal tissue; Article; autosome; breast adenocarcinoma; breast carcinogenesis; chromatin; chromatin immunoprecipitation; chromosomal instability; controlled study; female; fibroblast; gene expression profiling; immunofluorescence; karyotype; kinetics; mammary gland; microarray analysis; mitosis spindle; mouse; mutant; nonhuman; real time polymerase chain reaction; transgenic mouse; Western blotting; wild type, Oncology, article
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5مورد إلكتروني
المصدر: Department of Pediatrics Faculty Papers
مستخلص: Proximal spinal muscular atrophy (SMA) is an early onset, autosomal recessive motor neuron disease caused by loss of or mutation in SMN1 (survival motor neuron 1). Despite understanding the genetic basis underlying this disease, it is still not known why motor neurons (MNs) are selectively affected by the loss of the ubiquitously expressed SMN protein. Using a mouse embryonic stem cell (mESC) model for severe SMA, the RNA transcript profiles (transcriptomes) between control and severe SMA (SMN2+/+;mSmn-/-) mESC-derived MNs were compared in this study using massively parallel RNA sequencing (RNA-Seq). The MN differentiation efficiencies between control and severe SMA mESCs were similar. RNA-Seq analysis identified 3,094 upregulated and 6,964 downregulated transcripts in SMA mESC-derived MNs when compared against control cells. Pathway and network analysis of the differentially expressed RNA transcripts showed that pluripotency and cell proliferation transcripts were significantly increased in SMA MNs while transcripts related to neuronal development and activity were reduced. The differential expression of selected transcripts such as Crabp1, Crabp2 and Nkx2.2 was validated in a second mESC model for SMA as well as in the spinal cords of low copy SMN2 severe SMA mice. Furthermore, the levels of these selected transcripts were restored in high copy SMN2 rescue mouse spinal cords when compared against low copy SMN2 severe SMA mice. These findings suggest that SMN deficiency affects processes critical for normal development and maintenance of MNs.
مصطلحات الفهرس: Department of Pediatrics, Thomas Jefferson University, animal cell; animal experiment; animal model; animal tissue; Article; cell proliferation; controlled study; Crabp1 gene; Crabp2 gene; down regulation; embryo; embryonic stem cell; female; gene; gene dosage; gene expression; in vitro study; motoneuron; mouse; nerve cell differentiation; Nkx2.2 gene; nonhuman; pluripotent stem cell; RNA sequence; RNA transcription; SMN2 gene; spinal cord; spinal muscular atrophy; upregulation, Other Medical Sciences, article
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6مورد إلكتروني
المصدر: Department of Dermatology and Cutaneous Biology Faculty Papers
مستخلص: Generalized arterial calcification of infancy (GACI), an autosomal recessive disorder caused by mutations in the ENPP1 gene, manifests with extensive mineralization of the cardiovascular system. The affected individuals in most cases die within the first year of life, and there is currently no effective treatment for this disorder. In this study, we characterized a spontaneous mutant mouse, asj-2J, as a model for GACI. These mice were identified as part of a phenotypic deviant search in a large-scale production colony of BALB/cJ mice at The Jackson Laboratory. They demonstrated a characteristic gait due to stiffening of the joints, with phenotypic similarity to a previously characterized asj ("ages with stiffened joints") mouse, caused by a missense mutation in the Enpp1 gene. Complementation testing indicated that asj-2J and asj were allelic. PCR-based mutation detection strategy revealed in asj-2J mice a large, 40,035 bp, deletion spanning from intron 1 to the 3'-untranslated region of the Enpp1 gene, coupled with a 74 bp insertion. This was accompanied with a significant reduction in the plasma PPi concentration and reduced PPi/Pi ratio. As a consequence, extensive aberrant mineralization affecting the arterial vasculature, a number of internal organs, and the dermal sheath of vibrissae, a progressive biomarker of the ectopic mineralization process, was demonstrated by a combination of micro computed tomography, histopathology with calcium-specific stains, and direct chemical assay of calcium. Comparison of the asj and asj-2J mice demonstrated that the latter ones, particularly when placed on an acceleration diet high in phosphate and low in magnesium, had more extensive mineralization. Thus, the asj-2J mouse serves as a novel model for GACI, a currently intractable disorder.
مصطلحات الفهرس: Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, 3' untranslated region; animal experiment; animal model; animal tissue; artery calcification; Article; asj 2J mouse; asj mouse; autosomal recessive disorder; Bagg albino mouse; controlled study; dietary intake; Enpp1 gene; female; gait disorder; gene; generalized arterial calcification of infancy; genetic complementation; genome size; histopathology; indel mutation; intron; joint stiffness; large scale production; micro-computed tomography; missense mutation; molecular pathology; mouse; mouse model; mutant mouse strain; mutational analysis; nonhuman; phenotype; polymerase chain reaction; protein blood level; strain difference; vibrissa, Dermatology, article
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7مورد إلكتروني
المصدر: Department of Pediatrics Faculty Papers
مستخلص: Proximal spinal muscular atrophy (SMA) is an early onset, autosomal recessive motor neuron disease caused by loss of or mutation in SMN1 (survival motor neuron 1). Despite understanding the genetic basis underlying this disease, it is still not known why motor neurons (MNs) are selectively affected by the loss of the ubiquitously expressed SMN protein. Using a mouse embryonic stem cell (mESC) model for severe SMA, the RNA transcript profiles (transcriptomes) between control and severe SMA (SMN2+/+;mSmn-/-) mESC-derived MNs were compared in this study using massively parallel RNA sequencing (RNA-Seq). The MN differentiation efficiencies between control and severe SMA mESCs were similar. RNA-Seq analysis identified 3,094 upregulated and 6,964 downregulated transcripts in SMA mESC-derived MNs when compared against control cells. Pathway and network analysis of the differentially expressed RNA transcripts showed that pluripotency and cell proliferation transcripts were significantly increased in SMA MNs while transcripts related to neuronal development and activity were reduced. The differential expression of selected transcripts such as Crabp1, Crabp2 and Nkx2.2 was validated in a second mESC model for SMA as well as in the spinal cords of low copy SMN2 severe SMA mice. Furthermore, the levels of these selected transcripts were restored in high copy SMN2 rescue mouse spinal cords when compared against low copy SMN2 severe SMA mice. These findings suggest that SMN deficiency affects processes critical for normal development and maintenance of MNs.
مصطلحات الفهرس: Department of Pediatrics, Thomas Jefferson University, animal cell; animal experiment; animal model; animal tissue; Article; cell proliferation; controlled study; Crabp1 gene; Crabp2 gene; down regulation; embryo; embryonic stem cell; female; gene; gene dosage; gene expression; in vitro study; motoneuron; mouse; nerve cell differentiation; Nkx2.2 gene; nonhuman; pluripotent stem cell; RNA sequence; RNA transcription; SMN2 gene; spinal cord; spinal muscular atrophy; upregulation, Other Medical Sciences, article
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8مورد إلكتروني
المصدر: Department of Dermatology and Cutaneous Biology Faculty Papers
مستخلص: Pseudoxanthoma elasticum (PXE), a heritable ectopic mineralization disorder, is caused by mutations in the ABCC6 gene. Null mice (Abcc6(-/-) ) recapitulate the genetic, histopathologic and ultrastructural features of PXE, and they demonstrate early and progressive mineralization of vibrissae dermal sheath, which serves as a biomarker of the overall mineralization process. Recently, as part of a mouse aging study at The Jackson Laboratory, 31 inbred mouse strains were necropsied, and two of them, KK/HlJ and 129S1/SvImJ, were noted to have vibrissae dermal mineralization similar to Abcc6(-/-) mice. These two strains were shown to harbor a single nucleotide polymorphism (rs32756904) in the Abcc6 gene, which resulted in out-of-frame splicing and marked reduction in ABCC6 protein expression in the liver of these mice. The same polymorphism is present in two additional mouse strains, DBA/2J and C3H/HeJ, with similar reduction in Abcc6 protein levels, yet these mice did not demonstrate tissue mineralization when kept on standard rodent diet. However, all four mouse strains, when placed on experimental diet enriched in phosphate and low in magnesium, developed extensive ectopic mineralization. These results indicate that the genetic background of mice and the mineral composition of their diet can profoundly modulate the ectopic mineralization process predicated on mutations in the Abcc6 gene. These mice provide novel model systems to study the pathomechanisms and the reasons for strain background on phenotypic variability of PXE.
مصطلحات الفهرس: Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, 129S1/SvImJ mouse; ABCC6 gene; animal cell; animal experiment; animal model; animal tissue; article; C3H/He mouse; controlled study; DBA 2 mouse; diet; gene; gene mutation; genetic variability; histopathology; inbred mouse strain; KK/HlJ mouse; liver; magnesium blood level; mineralization; mouse; nonhuman; phosphate blood level; protein expression; pseudoxanthoma elasticum; single nucleotide polymorphism, Dermatology, article
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9مورد إلكتروني
المصدر: Department of Radiology Faculty Papers
مستخلص: There is a strong need to assess early tumor response to chemotherapy in order to avoid adverse effects from unnecessary chemotherapy and allow early transition to second-line therapy. This study was to quantify tumor perfusion changes with dynamic contrast-enhanced ultrasound (CEUS) in the evaluation of early tumor response to cytotoxic chemotherapy. Sixty nude mice bearing with MCF-7 breast cancer were administrated with either adriamycin or sterile saline. CEUS was performed on days 0, 2, 4 and 6 of the treatment, in which time-signal intensity (SI) curves were obtained from the intratumoral and depth-matched liver parenchyma. Four perfusion parameters including peak enhancement (PE), area under the curve of wash-in (WiAUC), wash-in rate (WiR) and wash-in perfusion index (WiPI) were calculated from perfusion curves and normalized with respect to perfusion of adjacent liver parenchyma. Histopathological analysis was conducted to evaluate tumor perfusion, tumor cell density, microvascular density (MVD) and proliferating cell density. Significant decreases of tumor normalized perfusion parameters (i.e., nPE, nWiAUC, nWiR and nWiPI) were noticed between adriamycin-treated and control groups (P0.05). Significant decreases of tumor perfusion, tumor cell density, MVD and proliferating cell density were seen in adrianycin-treated group 2 days after therapy when compared to control group (P
مصطلحات الفهرس: Department of Radiology, Thomas Jefferson University, animal experiment; animal model; animal tissue; antineoplastic activity; article; breast cancer; cancer chemotherapy; cancer size; cancer tissue; cell proliferation; cell strain MCF 7; contrast enhanced ultrasound; contrast enhancement; controlled study; drug efficacy; drug response; echography; female; histopathology; human; human cell; image analysis; immunohistochemistry; liver parenchyma; microvascular density; mouse; nonhuman; oncological parameters; tissue perfusion; tumor cell density; tumor vascularization; tumor xenograft; ultrasound transducer, Radiology, article
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10مورد إلكتروني
المصدر: Department of Biochemistry and Molecular Biology Faculty Papers
مستخلص: Generalized arterial calcification of infancy (GACI), an autosomal recessive disorder, is characterized by early mineralization of blood vessels, often diagnosed by prenatal ultrasound and usually resulting in demise during the first year of life. It is caused in most cases by mutations in the ENPP1 gene, encoding an enzyme that hydrolyzes ATP to AMP and inorganic pyrophosphate, the latter being a powerful anti-mineralization factor. Recently, a novel mouse phenotype was recognized as a result of ENU mutagenesis - those mice developed stiffening of the joints, hence the mutant mouse was named 'ages with stiffened joints' (asj). These mice harbor a missense mutation, p.V246D, in the Enpp1 gene. Here we demonstrate that the mutant ENPP1 protein is largely absent in the liver of asj mice, and the lack of enzymatic activity results in reduced inorganic pyrophosphate (PPi) levels in the plasma, accompanied by extensive mineralization of a number of tissues, including arterial blood vessels. The progress of mineralization is highly dependent on the mineral composition of the diet, with significant shortening of the lifespan on a diet enriched in phosphorus and low in magnesium. These results suggest that the asj mouse can serve as an animal model for GACI.
