scholarly journals Aromatase Expression in the Hippocampus of AD Patients and 5xFAD Mice

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Janine Prange-Kiel ◽  
Danuta A. Dudzinski ◽  
Felicitas Pröls ◽  
Markus Glatzel ◽  
Jakob Matschke ◽  
...  

Numerous studies show that 17β-estradiol (E2) protects against Alzheimer’s disease (AD) induced neurodegeneration. The E2-synthesizing enzyme aromatase is expressed in healthy hippocampi, but although the hippocampus is severely affected in AD, little is known about the expression of hippocampal aromatase in AD. To better understand the role of hippocampal aromatase in AD, we studied its expression in postmortem material from patients with AD and in a mouse model for AD (5xFAD mice). In human hippocampi, aromatase-immunoreactivity was observed in the vast majority of principal neurons and signal quantification revealed higher expression of aromatase protein in AD patients compared to age- and sex-matched controls. The tissue-specific first exons of aromatase I.f, PII, I.3, and I.6 were detected in hippocampi of controls and AD patients by RT-PCR. In contrast, 3-month-old, female 5xFAD mice showed lower expression of aromatase mRNA and protein (measured by qRT-PCR and semiquantitative immunohistochemistry) than WT controls; no such differences were observed in male mice. Our findings stress the importance of hippocampal aromatase expression in neurodegenerative diseases.

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Vanessa Laversenne ◽  
Sameer Nazeeruddin ◽  
Emma C. Källstig ◽  
Philippe Colin ◽  
Christel Voize ◽  
...  

AbstractThe brain pathology of Alzheimer’s disease (AD) is characterized by the misfolding and aggregation of both the amyloid beta (Aβ) peptide and hyperphosphorylated forms of the tau protein. Initial Aβ deposition is considered to trigger a sequence of deleterious events contributing to tau pathology, neuroinflammation and ultimately causing the loss of synapses and neurons. To assess the effect of anti-Aβ immunization in this context, we generated a mouse model by overexpressing the human tau protein in the hippocampus of 5xFAD mice. Aβ plaque deposition combined with human tau overexpression leads to an array of pathological manifestations including the formation of tau-positive dystrophic neurites and accumulation of hyperphosphorylated tau at the level of neuritic plaques. Remarkably, the presence of human tau reduces microglial clustering in proximity to the Aβ plaques, which may affect the barrier role of microglia. In this mouse model, continuous administration of anti-Aβ antibodies enhances the clustering of microglial cells even in the presence of tau. Anti-Aβ immunization increases plaque compaction, reduces the spread of tau in the hippocampal formation and prevents the formation of tau-positive dystrophic neurites. However, the treatment does not significantly reduce tau-induced neurodegeneration in the dentate gyrus. These results highlight that anti-Aβ immunization is able to enhance microglial activity around neuritic plaques, mitigating part of the tau-induced pathological manifestations.


2018 ◽  
Vol 47 (2) ◽  
pp. 579-589 ◽  
Author(s):  
Wei Li ◽  
Yaojun Lu ◽  
Ruijuan Han ◽  
Qiang Yue ◽  
Xiurong Song ◽  
...  

Background/Aims: The transplantation of cardiac progenitor cells (CPCs) improves neovascularization and left ventricular function after myocardial infarction (MI). The bone morphogenetic protein antagonist Gremlin 2 (Grem2) is required for early cardiac development and cardiomyocyte differentiation. The present study examined the role of Grem2 in CPC differentiation and cardiac repair. Methods: To determine the role of Grem 2 during CPC differentiation, c-Kit+ CPCs were cultured in differentiation medium for different times, and Grem2, Notch1 and Jagged1 expression was determined by RT-PCR and western blotting. Short hairpin RNA was used to silence Grem2 expression, and the expression of cardiomyocyte surface markers was assessed by RT-PCR and immunofluorescence staining. In vivo experiments were performed in a mouse model of left anterior descending coronary artery ligation-induced MI. Results: CPC differentiation upregulated Grem2 expression and activated the Notch1 pathway. Grem2 knockdown inhibited cardiomyocyte differentiation, and this effect was similar to that of Notch1 pathway inhibition in vitro. Jagged1 overexpression rescued the effects of Grem2 silencing. In vivo, Grem2 silencing abolished the protective effects of CPC injection on cardiac fibrosis and function. Conclusions: Grem2 regulates CPC cardiac differentiation by modulating Notch1 signaling. Grem2 enhances the protective effect of CPCs on heart function in a mouse model of MI, suggesting its potential as the rapeutic protein for cardiac repair.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1114-1114
Author(s):  
Mickaël Martin ◽  
Anne Marie Knapp ◽  
Dana Ghergus ◽  
Fabien Delmotte ◽  
Laurent Vallat ◽  
...  

Abstract Abnormal expression of the tyrosine kinase ZAP-70 by tumoral B cells in chronic lymphocytic leukemia (CLL) is associated with bad prognosis, related to B cell receptor (BCR) hypersignalling, clonal expansion and autoimmune cytopenia (AIC) occurrence, these latter being mostly induced by polyclonal IgG from the residual non tumoral B cells. We previously shown that ZAP-70 is expressed by these non tumoral B cells in CLL, positively associated with its expression in CLL B cells and with AIC occurrence (Ghergus et al. Poster ASH 2017). Here, we show for the first time a potential role of ZAP-70 expression in tolerance breakdown in CLL and in an original knock in mouse model overexpressing ZAP-70 conditionally in B cells. First, to assess a potential molecular link between ZAP-70+ CLL and non tumoral B cells, an analysis of their BCR repertoire has performed on FACS-sorting CD19+CD5-IgM-IgD- (non tumoral) and CD19+CD5+IgM-IgD- (tumoral) single B cells from blood samples of CLL patients with AIC. ZAP-70 positivity was screened by RT-PCR, and variable regions of heavy (IGVH) and light (IGVK/VL) immunoglobulin genes amplified by RT-PCR on ZAP-70+ cells. To date, analysis of 24 BCR sequences from 7 patients showed that non tumoral ZAP-70+ B cells were polyclonal, without stereotypy, using different V(D)J and CDR3 in comparison with those of the corresponding CLL B cells. IGVH of non tumoral ZAP-70+ B were mostly mutated, of replacement type, suggesting antigenic contact, contrary to CLL B cells. To determine potential autoreactivity of the non-tumoral ZAP-70+ B cells, IGVH and corresponding IGVK/VL were amplified for production of recombinant antibodies (rAb). To date, among 17 rAB from 7 different patients, 2/13 (15.4%) have an antinuclear autoreactivity on HEp-2 cells and 4/17 (23.5%) were polyreactive on ELISA (DNA, lipopolysaccharide, insulin), compared respectively to 6% and 4,3% of control B cells (Wardemann et al., Science 2003). Production of 7 additional rAb and tests for anti-erythrocytes and anti-platelets reactivity are in process. To study functional consequences of early ZAP-70 expression in B cells in vivo, we generated a knock in Zap-70+/Mb1-Cre+mouse model (KI ZAP), to induce conditional expression of ZAP-70 in the B cell compartment from the proB stage, with KI Zap-70+/Mb1-Cre-mice as controls (CTRL). The ZAP-70 mRNAs levels in B cells from KI ZAP mice were on average 20 times higher than that in CTRL B cells. Up to 20 months-old, KI ZAP mice did not develop signs of lymphoproliferation. KI ZAP mice had hypo-IgG since 16 weeks-old (p<0.001) together with hypo-IgM from 14 months-old (p<0.01). Immunophenotyping revealed a reduction in mature naive, mature switched as well as in germinal center B cells (p<0.001, p=0.002 and p<0.01 respectively) and a trend for plasma cells (p=0.07). Microarrays showed enrichment in circulating IgG and IgM autoantibodies against various antigens in KI ZAP mice. These mice had reduced apoptosis rates of proB (p<0.01), preB (p=0.02), and immatures B cells (p=0.03), together with enrichment in marginal zone (p=0.01), trend for transitional T2/T3, and reduction in B1a cells (p<0.01). After immunization by ovalbumin + Freund's adjuvant, a reduced production of specific IgG and IgM was observed (p=0.01 and p=0.03 respectively) with a trend in decreased number of antibody-secreting cells (p=0.07). KI ZAP B cells shown increased spontaneous activation and proliferation levels holding after BCR stimulation (p<0.01), as well as an increased intracellular calcic flow (p<0.001). Preliminary data suggested a reduced SYK phosphorylation after BCR stimulation in KI ZAP B cells. Our findings highlight for the first time that non tumoral B cells ZAP-70+ are distinct from CLL cells at cellular level, but probably enriched in autoreactive cells. Moreover, we shown that early ZAP-70 expression in normal B cells in vivois associated with autoimmune characteristics, together with partial block in B cells peripheral maturation, and a conversely early increased activation and proliferation status. ZAP-70 could interfere early with SYK leading to an altered BCR signaling responsible for defect in normal B maturation promoting emergence of autoreactive B cells. Mechanistic role of ZAP-70 in BCR signaling has to be further analyzed but our data open new opportunities involving ZAP-70 in the understanding of B cell development and physiopathology of tolerance breakdown. Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Author(s):  
Lizhe Zhu ◽  
Shibo Yu ◽  
Siyuan Jiang ◽  
Guanqun Ge ◽  
Yu Yan ◽  
...  

Abstract BackgroundThe homobox (HOX) gene family as a transcription factor encoding a specific nuclear protein is essential for embryonic development, differentiation, and homeostasis. The role of HOXB3 protein varies in different tumors. This study aims to explore the role of the HOXB3 gene in breast cancer.MethodDifferentiated expressed genes were screened by analyzing metastatic breast cancer gene chip data in TCGA and GEO database. The function of selected HOXB3 gene was also analyzed by GEPIA, Kaplan-Meier Plotter, Breast Cancer Gene-Expression Miner and metascape. Molecular biology methods such as qRT-PCR, western blot and IF was used to verify bio-informatics findings.ResultsBoth bio-informatics analyses and western blot showed that HOXB3 was lost in breast cancer compared to normal breast tissue. Survival analysis also showed that lower expression of HOXB3 was associated with poor prognosis. Bio-informatics analyses further showed that HOXB3 was positively correlated with hormone receptors. qRT-PCR, immunofluorescence and western blot also confirmed that HOXB3 had the highest expression in the immortalized breast epithelial cell line MCF-10A, lower in luminal breast cancer cell line T47D and the lowest in triple negative breast cancer (TNBC) cell line MDA-MB-231. Metascape for GO analysis of GEO data provided possible mechanism that HOXB3 could positively regulate cell adhesion, inhibit cell proliferation and activate immune response in breast cancer, and considered that HOXB3 might cause cell malignant transformation through the above pathways.ConclusionIn summary, HOXB3 expression was decreased in breast cancer, especially in hormone receptor-negative breast cancer. The lower expression of HOXB3 was associated with poor prognosis. It might become a new biomarker to predict prognosis of breast cancer.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Devin W McBride ◽  
Ari Dienel ◽  
Remya A Veettil ◽  
Kanako Matsumura ◽  
Peeyush Kumar T. ◽  
...  

Rationale: Microthrombosis has been suggested as a major factor contributing to delayed neurological deterioration in patients after subarachnoid hemorrhage (SAH). However, experimental studies on the role of microthrombi in delayed deficits after SAH has not been investigated. Our hypothesis is that, following SAH, mice which develop delayed neurological deficits have a greater number of microthrombi than mice which do not develop delayed neurological deficits. Methods: SAH was induced in adult male and female C57BL/6 mice via endovascular perforation. Mice were randomly assigned into sham (n=6/sex) or SAH groups (n=22-24/sex). Neurobehavior was performed on days 1-3, 5, and 7 post-SAH using a composite neuroscore. Animals were sacrificed on the day of delayed deficits or 7 days post-SAH. Microthrombi count and vessel diameters (for vasospasm) were measured using H&E stained brain slices. All outcomes were performed and all data were analyzed by a blinded investigator. Results: Seventeen percent (4/24) of male mice and thirty-six percent (8/22) of female mice developed delayed deficits on days 3-5 post-SAH (Figures 1A and 1B). Those mice which developed delayed deficits had significantly more microthrombi in their brains than mice which did not develop delayed deficits; vasospasm did not correlate with delayed deficits. Additionally, female SAH mice develop delayed deficits at a higher frequency than males (Figure 1C). Conclusions: This work shows for the first time delayed deficits in a SAH mouse model. Further, microthrombi correlated with delayed deficits, whereas no correlation was between delayed deficits and vasospasm. The data within this study suggests that preventing microthrombi may improve functional recovery and reduce the risk of delayed deficits.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1216-1216
Author(s):  
Chen Tian ◽  
Zhipan Cao ◽  
Qiao Li ◽  
Jinhong Wang ◽  
Zhenyu Ju ◽  
...  

Abstract Abstract 1216 During leukemia development, emerging leukemic cells out-compete normal hematopoietic cells and become predominant in the body. How hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) respond to the growth of leukemic cell population is an important, yet less investigated area. Our previous study demonstrated differential effects of a leukemic environment on normal HSCs and HPCs in the Notch1-induced T-ALL mouse model (Hu X, et al. Blood 2009). We found that normal HSCs were better preserved in the leukemic bone marrow in part due to increased quiescence of the HSCs and in contrast, HPCs were exhausted during the expansion of leukemic cells. Our current work is aimed to further explore the molecular mechanisms concerning the distinct impacts of leukemic environment on normal HSCs and HPCs in the T-ALL mouse model. Given the previous report by others showing that increased secretion of stem cell factor (SCF) by myeloid leukemia cells played an important role in inducing normal HSCs/HPCs out of their niche and thus allowing leukemic cells to occupy the niche in the human-NOD/SCID xeno-graft model (Sipkins DA et al, Science 2008), we first examined the expression of SCF by ELISA, Western blot and real-time RT PCR in both normal hematopoietic and leukemic cell fractions in the Notch1-induced T-ALL mouse model as previously reported. We found that while expression of SCF in peripheral blood (PB) or bone marrow (BM) was increased in the leukemic mice, both mRNA and protein levels of SCF in normal hematopoietic cells were higher than that in leukemic cells, thereby suggesting that elevated SCF might be mainly secreted by non-leukemic cells in the leukemic hosts of our model. Further assessments on the role of SCF in leukemogenesis with the mice specifically deficient in SCF in different niche cell types are currently under investigation in our laboratory. In order to define potential mediators in HSCs in response to leukemic cell growth, a microarray study on normal HSCs isolated from T-ALL leukemic mice and the control mice was conducted. Gene expression profiling showed significantly differed expression of 169 genes (127 up and 42 down). Especially, real-time RT PCR confirmed an increase of Hes1, p21, Fbxw11, IL-18R1 and Itgb3, and a decrease of CXCR4 and Mmp2. Interestingly, the expression of Hes1 and its target gene, p21 were elevated in normal HSCs but not in HPCs, letting us to hypothesize that Hes1 might be in part mediate the different responses of HSCs and HPCs to the T-ALL leukemic environment. To test this hypothesis, we ectopically expressed Hes1 in normal hematopoietic cells and then examined their functions under the leukemic condition. BM cells from B6.SJL mice were transduced with either MSCV-Hes1-IRES-GFP or control MSCV-GFP vector. After transduction, Hes1-GFP+or control-GFP+cells were co-transplanted with the Notch1-induced T-ALL cells into lethally irradiated C57BL/6J recipients. The engrafted cells from the leukemic BM were analyzed and Hes1-GFP+or control-GFP+cells were sorted for functional assessments. Interestingly, although over-expression of Hes1 inhibited the growth of colony forming cell (CFC) in vitro, it could potentiate the long-term repopulating cells by maintaining more cells in the quiescent (G0) state in vivo. Taken together, our current study supports a role of Hes1 in mediating the distinct responses of normal HSCs and HPCs to the T-ALL leukemic environment. Disclosures: No relevant conflicts of interest to declare.


2002 ◽  
Vol 3 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Lu Cai ◽  
Shali Chen ◽  
Terry Evans ◽  
M. George Cherian ◽  
Subrata Chakrabarti

In the present study, the role of endothelin-1 (ET-1) on alterations of hepatic and renal metallothionein (MT) and trace metals (Zn, Cu, and Fe) were investigated in streptozotocin (STZ)- induced diabetic rats. Diabetic rats, age- and sex-matched controls, as well as control and diabetic animals on a dualETA/ETBreceptor blocker, bosentan, were investigated after 6 months of follow-up. MT was measured by cadmium-heme assay. Metals were measured by atomic absorption spectrometer. ET-1 mRNA was analyzed by reverse transcriptase–polymerase chain reaction (RT-PCR) technique. Hepatic and renal ET-1 mRNA was increased in diabetic rats as compared to control rats, along with an increase in both hepatic and renal MT proteins. The increased hepatic MT protein level was associated with decreases in hepatic Cu and Fe, whereas increased renal MT was associated with increases in renal Cu and Fe accumulation. Zn levels were unaltered in both organs in diabetic rats. Bosentan treatment partially prevented the increase in MT levels in both liver and kidney, along with reduced serum creatinine and increased urinary creatinine levels. Further bosentan treatment corrected the increased Cu and Fe levels in the kidney in diabetic rats, but reduced hepatic Cu and Fe levels. No significant effects of bosentan treatment on nondiabetic rats were observed. The data suggest that the possible effects of ET antagonism in diabetes may be mediated via changes in MT and trace metals.


2021 ◽  
Author(s):  
qu yanlong ◽  
Wang Chunlei ◽  
Zhang Tao ◽  
Yang Li ◽  
Na Xinyu

Abstract Background: Osteosarcoma (OS) is a rare malignant primary tumor of mesenchymal origin affecting bone that occurs in adolescents and children. LncRNAs are important regulators of tumorigenesis and development. This study aimed to explore the role and molecular basis of LncRNA BACE1-AS in OS. Methods and results : Through the analysis of differential expressed lncRNAs in OS tissues by GEO database, LncRNA BACE1-AS displayed a remarkably lower expression. This found could also be observed in both OS tissues and cell lines by qRT-PCR. Furthermore, using Cell counting kit-8 (CCK-8), transwell, wound healing and westernblot assays, overexpression LncRNA BACE1-AS remarkably reduced cell proliferation, migration and invasion abilities in OS. In addition, LncRNA BACE1-AS was validated as a sponge of miR-762 through the prediction of lncRNASNP. Further, luciferase reporter and RIP assays were conducted to confirm the binding sites between LncRNA BACE1-AS and miR-762. SOX7 was a target of miR-762 and could be regulate by LncRNA BACE1-AS. Moreover, inhibition of miR-762 could attenuate the role of sh-LncRNA BACE1-AS in OS cells, at meanwhile reduced the expression of SOX7. Conclusion : In this study, LncRNA BACE1-AS regulated proliferation, migration, invasion and apoptosis of OS cells by miR-762/SOX7 axis, implying that LncRNA BACE1-AS was a potential target for OS therapy.


2010 ◽  
Vol 299 (6) ◽  
pp. E910-E917 ◽  
Author(s):  
Malathi Srinivasan ◽  
Cheol S. Choi ◽  
Pushpankur Ghoshal ◽  
Lioudmila Pliss ◽  
Jignesh D. Pandya ◽  
...  

Glucose-stimulated insulin secretion (GSIS) by β-cells requires the generation of ATP from oxidation of pyruvate as well as generation of coupling factors involving three different pyruvate cycling shuttles. The roles of several key enzymes involved in pyruvate cycling in β-cells have been documented using isolated islets and β-cell clonal lines. To investigate the role of the pyruvate dehydrogenase (PDH) complex (PDC) in GSIS, a murine model of β-cell-specific PDH deficiency (β-PDHKO) was created. Pancreatic insulin content was decreased in 1-day-old β-PDHKO male pups and adult male mice. The plasma insulin levels were decreased and blood glucose levels increased in β-PDHKO male mice from neonatal life onward. GSIS was reduced in isolated islets from β-PDHKO male mice with about 50% reduction in PDC activity. Impairment in a glucose tolerance test and in vivo insulin secretion during hyperglycemic clamp was evident in β-PDHKO adults. No change in the number or size of islets was found in pancreata from 4-wk-old β-PDHKO male mice. However, an increase in the mean size of individual β-cells in islets of these mice was observed. These findings show a key role of PDC in GSIS by pyruvate oxidation. This β-PDHKO mouse model represents the first mouse model in which a mitochondrial oxidative enzyme deletion by gene knockout has been employed to demonstrate an altered GSIS by β-cells.


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