- OSlms: A Web Server to Evaluate the Prognostic Value of Genes in Leiomyosarcoma FRONTIERS IN ONCOLOGY 2019; 9
- High Sensitive and Non-invasive ctDNAs Sequencing Facilitate Clinical Diagnosis And Clinical Guidance of Non-small Cell Lung Cancer Patient: A Time Course Study FRONTIERS IN ONCOLOGY 2018; 8
Thalidomide Reduces Hemorrhage of Brain Arteriovenous Malformations in a Mouse Model.
2018; 49 (5): 1232?40
Brain arteriovenous malformation (bAVM) is an important risk factor for intracranial hemorrhage. Current treatments for bAVM are all associated with considerable risks. There is no safe method to prevent bAVM hemorrhage. Thalidomide reduces nose bleeding in patients with hereditary hemorrhagic telangiectasia, an inherited disorder characterized by vascular malformations. In this study, we tested whether thalidomide and its less toxic analog, lenalidomide, reduce bAVM hemorrhage using a mouse model.bAVMs were induced through induction of brain focal activin-like kinase 1 (Alk1, an AVM causative gene) gene deletion and angiogenesis in adult Alk1-floxed mice. Thalidomide was injected intraperitoneally twice per week for 6 weeks, starting either 2 or 8 weeks after AVM induction. Lenalidomide was injected intraperitoneally daily starting 8 weeks after AVM induction for 6 weeks. Brain samples were collected at the end of the treatments for morphology, mRNA, and protein analyses. The influence of Alk1 downregulation on PDGFB (platelet-derived growth factor B) expression was also studied on cultured human brain microvascular endothelial cells. The effect of PDGFB in mural cell recruitment in bAVM was explored by injection of a PDGFB overexpressing lentiviral vector to the mouse brain.Thalidomide or lenalidomide treatment reduced the number of dysplastic vessels and hemorrhage and increased mural cell (vascular smooth muscle cells and pericytes) coverage in the bAVM lesion. Thalidomide reduced the burden of CD68+ cells and the expression of inflammatory cytokines in the bAVM lesions. PDGFB expression was reduced in ALK1-knockdown human brain microvascular endothelial cells and in mouse bAVM lesion. Thalidomide increased Pdgfb expression in bAVM lesion. Overexpression of PDGFB mimicked the effect of thalidomide.Thalidomide and lenalidomide improve mural cell coverage of bAVM vessels and reduce bAVM hemorrhage, which is likely through upregulation of Pdgfb expression.
View details for DOI 10.1161/STROKEAHA.117.020356
View details for PubMedID 29593101
View details for PubMedCentralID PMC5916043
Transient Depletion of Microglia Reduces the Severity of Brain Arteriovenous Malformation in a Mouse Model
LIPPINCOTT WILLIAMS & WILKINS. 2018
View details for Web of Science ID 000429723400304
- Animal Models and Prospective Therapeutic Targets for Brain Arteriovenous Malformation. Molecular, Genetic, and Cellular Advances in Cerebrovascular Diseases World Scientific. 2018: 83?126
Soluble FLT1 Gene Therapy Alleviates Brain Arteriovenous Malformation Severity.
2017; 48 (5): 1420?23
Brain arteriovenous malformation (bAVM) is an important risk factor for intracranial hemorrhage. Current therapies are associated with high morbidities. Excessive vascular endothelial growth factor has been implicated in bAVM pathophysiology. Because soluble FLT1 binds to vascular endothelial growth factor with high affinity, we tested intravenous delivery of an adeno-associated viral vector serotype-9 expressing soluble FLT1 (AAV9-sFLT1) to alleviate the bAVM phenotype.Two mouse models were used. In model 1, bAVM was induced in R26CreER;Eng(2f/2f) mice through global Eng gene deletion and brain focal angiogenic stimulation; AAV2-sFLT02 (an AAV expressing a shorter form of sFLT1) was injected into the brain at the time of model induction, and AAV9-sFLT1, intravenously injected 8 weeks after. In model 2, SM22?Cre;Eng(2f/2f) mice had a 90% occurrence of spontaneous bAVM at 5 weeks of age and 50% mortality at 6 weeks; AAV9-sFLT1 was intravenously delivered into 4- to 5-week-old mice. Tissue samples were collected 4 weeks after AAV9-sFLT1 delivery.AAV2-sFLT02 inhibited bAVM formation, and AAV9-sFLT1 reduced abnormal vessels in model 1 (GFP versus sFLT1: 3.66±1.58/200 vessels versus 1.98±1.29, P<0.05). AAV9-sFLT1 reduced the occurrence of bAVM (GFP versus sFLT1: 100% versus 36%) and mortality (GFP versus sFLT1: 57% [12/22 mice] versus 24% [4/19 mice], P<0.05) in model 2. Kidney and liver function did not change significantly. Minor liver inflammation was found in 56% of AAV9-sFLT1-treated model 1 mice.By applying a regulated mechanism to restrict sFLT1 expression to bAVM, AAV9-sFLT1 can potentially be developed into a safer therapy to reduce the bAVM severity.
View details for DOI 10.1161/STROKEAHA.116.015713
View details for PubMedID 28325846
View details for PubMedCentralID PMC5404983
Distinct molecular subtypes of uterine leiomyosarcoma respond differently to chemotherapy treatment.
2017; 17 (1): 639
Uterine leiomyosarcoma (ULMS) is an aggressive form of soft tissue tumors. The molecular heterogeneity and pathogenesis of ULMS are not well understood.Expression profiling data were used to determine the possibility and optimal number of ULMS molecular subtypes. Next, clinicopathological characters and molecular pathways were analyzed in each subtype to prospect the clinical applications and progression mechanisms of ULMS.Two distinct molecular subtypes of ULMS were defined based on different gene expression signatures. Subtype I ULMS recapitulated low-grade ULMS, the gene expression pattern of which resembled normal smooth muscle cells, characterized by overexpression of smooth muscle function genes such as LMOD1, SLMAP, MYLK, MYH11. In contrast, subtype II ULMS recapitulated high-grade ULMS with higher tumor weight and invasion rate, and was characterized by overexpression of genes involved in the pathway of epithelial to mesenchymal transition and tumorigenesis, such as CDK6, MAPK13 and HOXA1.We identified two distinct molecular subtypes of ULMS responding differently to chemotherapy treatment. Our findings provide a better understanding of ULMS intrinsic molecular subtypes, and will potentially facilitate the development of subtype-specific diagnosis biomarkers and therapy strategies for these tumors.
View details for DOI 10.1186/s12885-017-3568-y
View details for PubMedID 28893210
View details for PubMedCentralID PMC5594508
The roles of endoglin gene in cerebrovascular diseases.
Neuroimmunology and neuroinflammation
2017; 4: 199?210
Endoglin (ENG, also known as CD105) is a transforming growth factor ? (TGF?) associated receptor and is required for both vasculogenesis and angiogenesis. Angiogenesis is important in the development of cerebral vasculature and in the pathogenesis of cerebral vascular diseases. ENG is an essential component of the endothelial nitric oxide synthase activation complex. Animal studies showed that ENG deficiency impairs stroke recovery. ENG deficiency also impairs the regulation of vascular tone, which contributes to the pathogenesis of brain arteriovenous malformation (bAVM) and vasospasm. In human, functional haploinsufficiency of ENG gene causes type I hereditary hemorrhagic telangiectasia (HHT1), an autosomal dominant disorder. Compared to normal population, HHT1 patients have a higher prevalence of AVM in multiple organs including the brain. Vessels in bAVM are fragile and tend to rupture, causing hemorrhagic stroke. High prevalence of pulmonary AVM in HHT1 patients are associated with a higher incidence of paradoxical embolism in the cerebral circulation causing ischemic brain injury. Therefore, HHT1 patients are at risk for both hemorrhagic and ischemic stroke. This review summarizes the possible mechanism of ENG in the pathogenesis of cerebrovascular diseases in experimental animal models and in patients.
View details for DOI 10.20517/2347-8659.2017.18
View details for PubMedID 29098173
View details for PubMedCentralID PMC5663457
Activation of Alpha-7 Nicotinic Acetylcholine Receptor Reduces Brain Edema in Mice with Ischemic Stroke and Bone Fracture.
Stroke is an important risk factor for bone fracture. We showed previously that bone fracture at the acute stage of ischemic stroke worsens, and activation of ?-7 nicotinic acetylcholine receptor (?-7 nAchR) improves, stroke recovery by attenuating inflammation. We hypothesized that activation of ?-7 nAchR also improves the blood-brain barrier (BBB) integrity. Permanent distal middle cerebral artery occlusion (pMCAO) was performed on C57BL/6J mice followed by tibia fracture 1 day later. Mice were treated with 0.8 mg/kg PHA 568487 (PHA, ?-7 nAchR-specific agonist), 6 mg/kg methyllycaconitine (MLA, ?-7 nAchR antagonist), or saline 1 and 2 days after pMCAO. Brain water content, the expression of monoamine oxidase B (MAO-B), and tight junction protein (claudin-5) were assessed. We found that tibia fracture increased water content in the ischemic stroke brain (p = 0.006) and MAO-B-positive astrocytes (p < 0.001). PHA treatment reduced water content and MAO-B-positive astrocytes and increased claudin-5 expression in stroke and stroke + tibia fracture mice (p < 0.05), while MLA had the opposite effect. Our findings suggest that in addition to inhibiting inflammation, activation of ?-7 nAchR also reduces brain edema, possibly through diminished astrocyte oxidative stress and improved BBB integrity. Thus, the ?-7 nAchR-specific agonist could be developed into a new therapy for improving recovery of patients with stroke or stroke + bone fracture.
View details for PubMedID 27914011
View details for PubMedCentralID PMC5457363
BECN1/Beclin 1 sorts cell-surface APP/amyloid ß precursor protein for lysosomal degradation.
The regulation of plasma membrane (PM)-localized transmembrane protein/receptor trafficking has critical implications for cell signaling, metabolism and survival. In this study, we investigated the role of BECN1 (Beclin 1) in the degradative trafficking of PM-associated APP (amyloid ? precursor protein), whose metabolism to amyloid-?, an essential event in Alzheimer disease, is dependent on divergent PM trafficking pathways. We report a novel interaction between PM-associated APP and BECN1 that recruits macroautophagy/endosomal regulatory proteins PIK3C3 and UVRAG. We found that BECN1 promotes surface APP internalization and sorting predominantly to endosomes and endolysosomes. BECN1 also promotes the targeting of a smaller fraction of internalized APP to LC3-positive phagophores, suggesting a role for BECN1-dependent PM macroautophagy in APP degradation. Furthermore, BECN1 facilitates lysosomal degradation of surface APP and reduces the secretion of APP metabolites (soluble ectodomains, sAPP). The association between APP and BECN1 is dependent on the evolutionarily conserved domain (ECD) of BECN1 (amino acids 267-337). Deletion of a BECN1 ECD subregion (amino acids 285-299) did not impair BECN1- PIK3C3 interaction, PtdIns3K function or macroautophagy, but was sufficient to impair the APP-BECN1 interaction and BECN1's effects on surface APP internalization and degradation, resulting in increased secretion of sAPPs. Interestingly, both the BECN1-APP association and BECN1-dependent APP endocytosis and degradative trafficking were negatively regulated by active AKT. Our results further implicate phosphorylation of the BECN1 Ser295 residue in the inhibition of APP degradation by AKT. Our studies reveal a novel function for BECN1 in the sorting of a plasma membrane protein for endolysosomal and macroautophagic degradation.
View details for PubMedID 27715386
Persistent infiltration and pro-inflammatory differentiation of monocytes cause unresolved inflammation in brain arteriovenous malformation
2016; 19 (4): 451-461
An abnormally high number of macrophages are present in human brain arteriovenous malformations (bAVM) with or without evidence of prior hemorrhage, causing unresolved inflammation that may enhance abnormal vascular remodeling and exacerbate the bAVM phenotype. The reasons for macrophage accumulation at the bAVM sites are not known. We tested the hypothesis that persistent infiltration and pro-inflammatory differentiation of monocytes in angiogenic tissues increase the macrophage burden in bAVM using two mouse models and human monocytes. Mouse bAVM was induced through deletion of AVM causative genes, Endoglin (Eng) globally or Alk1 focally, plus brain focal angiogenic stimulation. An endothelial cell and vascular smooth muscle cell co-culture system was used to analyze monocyte differentiation in the angiogenic niche. After angiogenic stimulation, the Eng-deleted mice had fewer CD68(+) cells at 2 weeks (P = 0.02), similar numbers at 4 weeks (P = 0.97), and more at 8 weeks (P = 0.01) in the brain angiogenic region compared with wild-type (WT) mice. Alk1-deficient mice also had a trend toward more macrophages/microglia 8 weeks (P = 0.064) after angiogenic stimulation and more RFP(+) bone marrow-derived macrophages than WT mice (P = 0.01). More CD34(+) cells isolated from peripheral blood of patients with ENG or ALK1 gene mutation differentiated into macrophages than those from healthy controls (P < 0.001). These data indicate that persistent infiltration and pro-inflammatory differentiation of monocytes might contribute to macrophage accumulation in bAVM. Blocking macrophage homing to bAVM lesions should be tested as a strategy to reduce the severity of bAVM.
View details for DOI 10.1007/s10456-016-9519-4
View details for Web of Science ID 000384411900001
View details for PubMedID 27325285
View details for PubMedCentralID PMC5029790
Bone Fracture Pre-Ischemic Stroke Exacerbates Ischemic Cerebral Injury in Mice
2016; 11 (4)
Ischemic stroke is a devastating complication of bone fracture. Bone fracture shortly after stroke enhances stroke injury by augmenting inflammation. We hypothesize that bone fracture shortly before ischemic stroke also exacerbates ischemic cerebral injury. Tibia fracture was performed 6 or 24 hours before permanent middle cerebral artery occlusion (pMCAO) on C57BL/6J mice or Ccr2RFP/+Cx3cr1GFP/+ mice that have the RFP gene knocked into one allele of Ccr2 gene and GFP gene knocked into one allele of Cx3cr1 gene. Behavior was tested 3 days after pMCAO. Infarct volume, the number of CD68+ cells, apoptotic neurons, bone marrow-derived macrophages (RFP+), and microgila (GFP+) in the peri-infarct region were quantified. Compared to mice subjected to pMCAO only, bone fracture 6 or 24 hours before pMCAO increased behavioral deficits, the infarct volume, and the number of CD68+ cells and apoptotic neurons in the peri-infarct area. Both bone marrow-derived macrophages (CCR2+) and microglia (CX3CR1+) increased in the peri-infarct regions of mice subjected to bone fracture before pMCAO compared to stroke-only mice. The mice subjected to bone fracture 6 hours before pMCAO had more severe injury than mice that had bone fracture 24 hours before pMCAO. Our data showed that bone fracture shortly before stroke also increases neuroinflammation and exacerbates ischemic cerebral injury. Our findings suggest that inhibition of neuroinflammation or management of stroke risk factors before major bone surgery would be beneficial for patients who are likely to suffer from stroke.
View details for DOI 10.1371/journal.pone.0153835
View details for Web of Science ID 000374527000054
View details for PubMedID 27089041
View details for PubMedCentralID PMC4835054
Vascular Integrity in the Pathogenesis of Brain Arteriovenous Malformation.
Acta neurochirurgica. Supplement
2016; 121: 29-35
Brain arteriovenous malformation (bAVM) is an important cause of intracranial hemorrhage (ICH), particularly in the young population. ICH is the first clinical symptom in about 50 % of bAVM patients. The vessels in bAVM are fragile and prone to rupture, causing bleeding into the brain. About 30 % of unruptured and non-hemorrhagic bAVMs demonstrate microscopic evidence of hemosiderin in the vascular wall. In bAVM mouse models, vascular mural cell coverage is reduced in the AVM lesion, accompanied by vascular leakage and microhemorrhage. In this review, we discuss possible signaling pathways involved in abnormal vascular development in bAVM.
View details for DOI 10.1007/978-3-319-18497-5_6
View details for PubMedID 26463919
View details for PubMedCentralID PMC4654926
Inhibition of pathological brain angiogenesis through systemic delivery of AAV vector expressing soluble FLT1
2015; 22 (11): 893-900
The soluble vascular endothelial growth factor (VEGF) receptor 1 (sFLT1) has been tested in both animals and humans for anti-angiogenic therapies, for example, age-related macular degeneration. We hypothesized that adeno-associated viral vector (AAV)-mediated sFLT1 expression could be used to inhibit abnormal brain angiogenesis. We tested the anti-angiogenic effect of sFLT1 and the feasibility of using AAV serotype 9 to deliver sFLT1 through intravenous injection (IV) to the brain angiogenic region. AAVs were packaged in AAV serotypes 1 and 2 (stereotactic injection) and 9 (IV injection). Brain angiogenesis was induced in adult mice through stereotactic injection of AAV1-VEGF. AAV2-sFLT02 containing sFLT1 VEGF-binding domain (domain 2) was injected into the brain angiogenic region, and AAV9-sFLT1 was injected into the jugular vein at the time of or 4 weeks after AAV1-VEGF injection. We showed that AAV2-sFLT02 inhibited brain angiogenesis at both time points. IV injection of AAV9-sFLT1 inhibited angiogenesis only when the vector was injected 4 weeks after angiogenic induction. Neither lymphocyte infiltration nor neuron loss was observed in AAV9-sFLT1-treated mice. Our data show that systemically delivered AAV9-sFLT1 inhibits angiogenesis in the mouse brain, which could be utilized to treat brain angiogenic diseases such as brain arteriovenous malformation.
View details for DOI 10.1038/gt.2015.57
View details for Web of Science ID 000364574500007
View details for PubMedID 26090874
View details for PubMedCentralID PMC4636448
Neuropathologic analysis of Tyr69His TTR variant meningovascular amyloidosis with dementia.
Acta neuropathologica communications
2015; 3 (1): 43-?
Transthyretin/TTR gene mutations usually cause systemic amyloidotic diseases. Few TTR variants preferentially affect the central nervous system, manifesting as oculoleptomeningeal amyloidosis. Patients with TTR meningovascular amyloidosis often show dementia, however the neuropathologic features of dementia in these cases have not been elucidated. We report the neuropathologic findings from a brain autopsy of a 72-year-old man with the rare Tyr69His (Y69H) TTR gene variant, dementia and ataxia. Severe amyloid deposits were observed in the leptomeninges and in a subpial and subependymal distribution. Mass spectrometry analysis demonstrated that the amyloid deposits were comprised of over 80 % of the variant TTR. TTR was undetectable by mass spectrometry in the neocortex subjacent to the subpial amyloid deposits. Subpial TTR amyloid deposits were associated with brisk superficial reactive gliosis and siderosis in the neocortex and cerebellar cortex. Subependymal TTR amyloid deposits were associated with subjacent myelin pallor in the hippocampal outflow tract structures including the alveus, fimbria and fornix. Phospho-tau immunostains demonstrated transentorhinal-stage neurofibrillary degeneration (Braak stage II) which, in the absence of neocortical amyloid-beta and neuritic plaques, was indicative of primary age-related tauopathy (PART). However, distinctive phospho-tau aggregates were observed subjacent to the subpial TTR amyloid deposits in all regions of the neocortex, including the primary motor and striate cortices, suggesting a potential link between TTR amyloid and neocortical tauopathy. Our report reveals novel insights into the potential neuropathologic substrates of dementia in variant TTR amyloidosis that need to be investigated in larger autopsy series.
View details for DOI 10.1186/s40478-015-0216-0
View details for PubMedID 26156087
View details for PubMedCentralID PMC4496870
- GA binding protein augments autophagy via transcriptional activation of BECN1-PIK3C3 complex genes AUTOPHAGY 2014; 10 (9): 1622-1636
- Mutant LRRK2 enhances glutamatergic synapse activity and evokes excitotoxic dendrite degeneration. Biochimica et biophysica acta 2014; 1842 (9): 1596-1603
Transcriptional and Post-Transcriptional Regulation of SPAST, the Gene Most Frequently Mutated in Hereditary Spastic Paraplegia
2012; 7 (5)
Hereditary spastic paraplegias (HSPs) comprise a group of neurodegenerative disorders that are characterized by progressive spasticity of the lower extremities, due to axonal degeneration in the corticospinal motor tracts. HSPs are genetically heterogeneous and show autosomal dominant inheritance in ?70-80% of cases, with additional cases being recessive or X-linked. The most common type of HSP is SPG4 with mutations in the SPAST gene, encoding spastin, which occurs in 40% of dominantly inherited cases and in ?10% of sporadic cases. Both loss-of-function and dominant-negative mutation mechanisms have been described for SPG4, suggesting that precise or stoichiometric levels of spastin are necessary for biological function. Therefore, we hypothesized that regulatory mechanisms controlling expression of SPAST are important determinants of spastin biology, and if altered, could contribute to the development and progression of the disease. To examine the transcriptional and post-transcriptional regulation of SPAST, we used molecular phylogenetic methods to identify conserved sequences for putative transcription factor binding sites and miRNA targeting motifs in the SPAST promoter and 3'-UTR, respectively. By a variety of molecular methods, we demonstrate that SPAST transcription is positively regulated by NRF1 and SOX11. Furthermore, we show that miR-96 and miR-182 negatively regulate SPAST by effects on mRNA stability and protein level. These transcriptional and miRNA regulatory mechanisms provide new functional targets for mutation screening and therapeutic targeting in HSP.
View details for DOI 10.1371/journal.pone.0036505
View details for Web of Science ID 000305349800070
View details for PubMedID 22574173