Citations

PurposeTo develop a robust, accurate, and accelerated T1ρ quantification solution for submillimeter in vivo whole‐brain imaging.MethodsA multislice T1ρ mapping solution (MS‐T1ρ) was developed based on a two‐acquisition scheme using turbo spin echo with RF cycling to allow for whole‐brain coverage with 0.8‐mm in‐plane resolution. A compressed sensing–based fast imaging method, SCOPE, was used to accelerate the MS‐T1ρ acquisition time to a total scan time of 3 minutes 31 seconds. A phantom experiment was conducted to assess the accuracy of MS‐T1ρ by comparing the T1ρ value obtained using MS‐T1ρ with the reference value obtained using the standard single‐slice T1ρ mapping method. In vivo scans of 13 volunteers were acquired prospectively to validate the robustness of MS‐T1ρ.ResultsIn the phantom study, the T1ρ values obtained with MS‐T1ρ were in good agreement with the reference T1ρ values (R2 = 0.9991) and showed high consistency throughout all slices (coefficient of variation = 2.2 ± 2.43%). In the in vivo experiments, T1ρ maps were successfully acquired for all volunteers with no visually noticeable artifacts. There was no significant difference in T1ρ values between MS‐T1ρ acquisitions and fully sampled acquisitions for all brain tissues (p‐value > .05). In the intraclass correlation coefficient and Bland‐Altman analyses, the accelerated T1ρ measurements show moderate to good agreement to the fully sampled reference values.ConclusionThe proposed MS‐T1ρ solution allows for high‐resolution whole‐brain T1ρ mapping within 4 minutes and may provide a potential tool for investigating neural diseases.

Background: Foam-mediated external suction (FMES) has previously shown to improve tissue microcirculation. We hypothesized that preconditioning fasciocutaneous perforator flaps with FMES would augment perfusion and demonstrate greater capillary recruitment. Methods: Gluteal perforator flaps were designed on sixteen 400 g rats. Continuous FMES at −125 mm Hg was applied on one side (intervention) to precondition tissue for 5 days, with the contralateral side as a paired control. In group A, we assessed changes following pretreatment, after surgery, and 7 days postprocedure, and in group B, we evaluated changes during preconditioning alone. In group A (N = 8), control and intervention flaps were assessed using laser-assisted indocyanine green fluorescence angiography. In group B, flap regions were assessed using 4-dimensional computed tomographic angiography. All flaps were analyzed for microvessel density using micro–computed tomography and histological assessment using hematoxylin and eosin and CD3 immunohistochemistry. Results: Thirty-two flaps were included in this study (N = 16 intervention and matched controls). Four-dimensional computed tomographic angiography demonstrated 17% greater tissue perfusion in preconditioned flaps (mean, 78.7 HU; SD, 8.8) versus controls (mean, 67.3 HU; SD, 15.7; P < 0.01). Laser-assisted indocyanine green fluorescence angiography showed a 30% higher mean absolute intensity in preconditioned flaps versus controls (P < 0.01). Postsurgery mean absolute intensity in preconditioned flaps remained 21% higher than in controls (P = 0.03). Preconditioned flaps demonstrated a 2-fold increase in mean vessel volume of 9.1 mm3 (SD, 7) versus 4.5 mm3 (SD, 3) in controls (P = 0.04); there was a 33% higher mean area fraction of CD31 in preconditioned flaps, 3.9% (SD, 3) versus 2.9% (SD, 3) in controls (P = 0.03). Conclusion: FMES preconditioning has the potential to augment vascularity of tissue for flap harvest; however, further experimental studies are required to optimize strategies and evaluate long-term effects for clinical applications.

Objective Intrahepatic cholangiocarcinoma (ICC)—a rare liver malignancy with limited therapeutic options—is characterised by aggressive progression, desmoplasia and vascular abnormalities. The aim of this study was to determine the role of placental growth factor (PlGF) in ICC progression. Design We evaluated the expression of PlGF in specimens from ICC patients and assessed the therapeutic effect of genetic or pharmacologic inhibition of PlGF in orthotopically grafted ICC mouse models. We evaluated the impact of PlGF stimulation or blockade in ICC cells and cancer-associated fibroblasts (CAFs) using in vitro 3-D coculture systems. Results PlGF levels were elevated in human ICC stromal cells and circulating blood plasma and were associated with disease progression. Single-cell RNA sequencing showed that the major impact of PlGF blockade in mice was enrichment of quiescent CAFs, characterised by high gene transcription levels related to the Akt pathway, glycolysis and hypoxia signalling. PlGF blockade suppressed Akt phosphorylation and myofibroblast activation in ICC-derived CAFs. PlGF blockade also reduced desmoplasia and tissue stiffness, which resulted in reopening of collapsed tumour vessels and improved blood perfusion, while reducing ICC cell invasion. Moreover, PlGF blockade enhanced the efficacy of standard chemotherapy in mice-bearing ICC. Conclusion PlGF blockade leads to a reduction in intratumorous hypoxia and metastatic dissemination, enhanced chemotherapy sensitivity and increased survival in mice-bearing aggressive ICC.

AbstractPurpose:Fumarate hydratase–deficient renal cell carcinoma (FH-deficient RCC) is a rare but lethal subtype of RCC. Little is known about the genomic profile of FH-deficient RCC, and the therapeutic options for advanced disease are limited. To this end, we performed a comprehensive genomics study to characterize the genomic and epigenomic features of FH-deficient RCC.Experimental Design:Integrated genomic, epigenomic, and molecular analyses were performed on 25 untreated primary FH-deficient RCCs. Complete clinicopathologic and follow-up data of these patients were recorded.Results:We identified that FH-deficient RCC manifested low somatic mutation burden (median 0.58 mutations per megabase), but with frequent somatic copy-number alterations. The majority of FH-deficient RCCs were characterized by a CpG sites island methylator phenotype, displaying concerted hypermethylation at numerous CpG sites in genes of transcription factors, tumor suppressors, and tumor hallmark pathways. However, a few cases (20%) with low metastatic potential showed relatively low DNA methylation levels, indicating the heterogeneity of methylation pattern in FH-deficient RCC. Moreover, FH-deficient RCC is potentially highly immunogenic, characterized by increased tumor T-cell infiltration but high expression of immune checkpoint molecules in tumors. Clinical data further demonstrated that patients receiving immune checkpoint blockade–based treatment achieved improved progression-free survival over those treated with antiangiogenic monotherapy (median, 13.3 vs. 5.1 months; P = 0.03).Conclusions:These results reveal the genomic features and provide new insight into potential therapeutic strategies for FH-deficient RCC.

Objective: Renovascular hypertension (RVH) induces hemodynamic and humoral aberrations that may impair cardiac function, structure and mechanics, including cardiac twist and deformation. Revascularization of a stenotic renal artery can decrease blood pressure (BP), but its ability to restore cardiac mechanics in RVH remains unclear. We hypothesized that percutaneous transluminal renal angioplasty (PTRA) would improve cardiac function and left ventricular (LV) deformation in swine RVH. Methods: Seventeen domestic pigs were studied for 16 weeks: RVH, RVH + PTRA and normal controls (n = 5–6 each). Global LV function was estimated by multidetector computed-tomography, and LV deformation by electrocardiographically triggered MRI tagging at the apical, mid, and basal LV levels. Cardiomyocyte hypertrophy, myocardial capillary density, and fibrosis were evaluated ex vivo. Results: BP and wall thickness were elevated in RVH and decreased by PTRA, yet remained higher than in controls. LV myocardial muscle mass increased in RVH pigs, which also developed diastolic dysfunction, whereas cardiac output increased. Furthermore, both apical rotation and peak torsion angle increased in RVH compared with controls. Ex vivo, RVH induced myocardial fibrosis and vascular rarefaction. PTRA restored cardiac function and alleviated hypertrophy, vascular rarefaction, and fibrosis. PTRA also normalized apical rotation and peak torsion angle, and elevated basal peak radial strain and apical peak radial strain compared with RVH. Conclusion: In addition to cardiac LV adaptive hypertrophy and diastolic dysfunction, short-term RVH causes cardiac deformation. Despite only partial improvement in BP, PTRA effectively restored cardiac function and reversed abnormal mechanics. Hence, renal revascularization may be a useful strategy to preserve cardiac function in RVH.

Scattered tubular-like cells (STCs), dedifferentiated renal tubular epithelial cells, contribute to renal self-healing, but severe injury might blunt their effectiveness. We hypothesized that ischemic renovascular disease (RVD) induces senescence in STC and impairs their reparative potency. CD24+/CD133+ STCs were isolated from swine kidneys after 16 weeks of RVD or healthy controls. To test their reparative capabilities in injured kidneys, control or RVD-STC (5×10 5 ) were prelabeled and injected into the aorta of 2 kidneys, 1-clip (2k,1c) mice 2 weeks after surgery. Murine renal function and oxygenation were studied in vivo 2 weeks after injection using micro-magnetic resonance imaging, and fibrosis, tubulointerstitial injury, capillary density, and expression of profibrotic and inflammatory genes ex vivo. STC isolated from swine RVD kidneys showed increased gene expression of senescence and senescence-associated secretory phenotype markers and positive SA-β-gal staining. Delivery of normal pig STCs in 2k,1c mice improved murine renal perfusion, blood flow, and glomerular filtration rate, and downregulated profibrotic and inflammatory gene expression. These renoprotective effects were blunted using STC harvested from RVD kidneys, which also failed to attenuate hypoxia, fibrosis, tubular injury, and capillary loss in injured mouse 2k,1c kidneys. Hence, RVD may induce senescence in endogenous STC and impair their reparative capacity. These observations implicate cellular senescence in the pathophysiology of ischemic kidney disease and support senolytic therapy to permit self-healing of senescent kidneys.

Abstract ObjectiveChondrocyte apoptosis plays a vital role in osteoarthritis (OA) progression. Angelica sinensis polysaccharide (ASP), a traditional chinese medicine, possesses anti-inflammatory and anti-apoptotic properties in chondrocytes. This study aimed to determine the protective role of ASP on sodium nitroprusside (SNP)-induced chondrocyte apoptosis, and explore the underlying mechanism.MethodHuman primary chondrocytes isolated from articular cartilage of OA patients were treated with SNP alone or in combination with different doses of ASP. Cell viability and apoptosis were assessed, and apoptosis-related proteins including Bcl-2 and Bax were detected. Autophagy levels were evaluated by light chain 3 (LC3)II immunofluorescence staining, mRFP-GFP-LC3 fluorescence localisation and western blot (LC3II, p62, Beclin-1, Atg5). Meanwhile, activation of ERK 1/2 pathway was determined by western blot. The autophagy inhibitors, 3-Methyladenine (3-MA), chloroquine (CQ) and a specific inhibitor of ERK1/2, SCH772984, were used respectively to confirm the autophagic effect of ASP.ResultsThe results showed that SNP-induced chondrocyte apoptosis was significantly rescued by ASP, whereas ASP alone promoted chondrocytes proliferation. The anti-apoptotic effect of ASP was related to the enhanced autophagy and depended on the activation of ERK1/2 pathway.ConclusionASP markedly rescued SNP-induced apoptosis by activating ERK1/2-dependent autophagy in chondrocytes, and it made ASP a potential therapeutic supplementation for OA treatment.

We conducted a survey of primary care clinicians and gastroenterologists (n = 938) between 11/06/19–12/06/19 to assess knowledge and attitudes regarding colorectal cancer screening. We assessed clinicians’ attitudes toward lowering the colorectal cancer screening initiation age to 45 years, a topic of current debate. We also evaluated provider and practice characteristics associated with agreement. Only 38.1% of primary care clinicians endorsed colorectal cancer screening initiation at age 45 years, compared to 75.5% of gastroenterologists (p < .0001). Gastroenterologists were over 5 times more likely than primary care clinicians to endorse lowering the screening initiation age (OR = 5.30, 3.54-7.93). Other factors found to be independently associated with agreement with colorectal cancer screening initiation at age 45 years included seeing more than 25 patients per day (vs. fewer) and suburban (vs. urban) location. Results emphasize the need for collaboration between primary care clinicians and gastroenterologists to ensure that patients receive consistent messaging and evidence-based care.

AbstractBackgroundThe pathological features of AD are neurofibrillary tangles (NFTs) composed of highly phosphorylated tau and senile plaques (SPs) composed of amyloid β protein (Aβ). It was suggested that Cu2 + induced hyperphosphorylation of tau and Zn2 + deposits on SPs. Clioquinol (CQ) has a mild chelating effect on Zn2 + and Cu2 +. In addition, CQ has been shown to reduce Aβ aggregation by removing Zn2+ from SPs. However, the effect of CQ on tau aggregation is not fully understood. The purpose of our study is to examine the effect of CQ on tau metabolism by using a cell culture model of tauopathy.MethodsHuman neuroblastoma cell line M1C cells that express wild‐type tau protein (4R0N) via tetracycline (Tet) off induction was used. M1C cells were exposed to 0.1‐10 μM CQ on day 4 of Tet‐Off induction, and harvested at the end of Day 5. Total tau detected by Tau5, and phosphorylated tau detected by PS199/202, AT180, AT270, CP13, and PHF‐1 antibodies, were examined using Western blot analysis. Immunocytochemical studies, fractional analysis and immunoprecipitation of ubiquitinated tau were also performed. Tau kinases including c‐Jun N‐terminal kinase (JNK), and P38 MAPK and tau phosphatase, protein phosphatase 2A (PP2A) were also examined. C‐terminal truncated pathological tau was detected by using the antibody TauC3. In addition, autophagy and proteasome activity were also examined.ResultPhosphorylated tau levels were reduced by 1‐10 μM CQ treatment. Tau kinases, JNK and p38 MAPK were inactivated by CQ treatment. Interestingly, activation of the tau phosphatase PP2A was also observed with CQ treatment. Fractionation studies showed that CQ treatment reduced AT180 and AT270 positive high molecular weight tau in the Tris‐insoluble, sarkosyl‐soluble fraction. CQ also reduced tau oligomer specific antibody TOC1‐positive oligomeric tau. CQ reduced caspase‐cleaved tau detected by antibody TauC3. P62 levels were reduced by CQ treatment, suggesting that CQ activates autophagy. In addition, CQ slightly reduced high molecular weight ubiquitinated tau. This implies activation of the ubiquitin‐proteasome by CQ.ConclusionCQ could provide beneficial effects against pathogenic forms of tau via multiple mechanisms and may represent a viable therapeutic approach for AD and other tauopathies.

Abstract BACKGROUND Renovascular hypertension (RVH) often manifest with metabolic syndrome (MetS) as well. Coexisting MetS and hypertension increases cardiovascular morbidity and mortality, but the mechanisms underlying cardiac injury remain unknown. We hypothesized that superimposition of MetS induces myocardial mitochondrial damage, leading to cardiac injury and dysfunction in swine RVH. METHODS Pigs were studied after 16 weeks of diet-induced MetS with or without RVH (unilateral renal artery stenosis), and Lean controls (n = 6 each). Systolic and diastolic cardiac function were assessed by multidetector CT, and cardiac mitochondrial morphology (electron microscopy) and myocardial function in tissue and isolated mitochondria. RESULTS Body weight was similarly higher in MetS groups vs. Lean. RVH groups achieved significant stenosis and developed hypertension. Mitochondrial matrix density and adenosine triphosphate production were lower and H2O2 production higher in RVH groups vs. Lean and MetS. Lean + RVH (but not MetS + RVH) activated mitophagy, which was associated with decreased myocardial expression of mitophagy-related microRNAs. MetS groups exhibited higher numbers of intermitochondrial junctions, which could have prevented membrane depolarization/activation of mitophagy in MetS + RVH. Cardiac fibrosis, hypertrophy (increased left ventricular muscle mass), and diastolic function (decreased E/A ratio) were greater in MetS + RVH vs. Lean + RVH. CONCLUSIONS MetS+RVH induces myocardial mitochondrial damage and dysfunction. MetS + RVH failed to activate mitophagy, resulting in greater cardiac remodeling, fibrosis, and diastolic dysfunction. Mitochondrial injury and impaired mitophagy may constitute important mechanisms and therapeutic targets to ameliorate cardiac damage and dysfunction in patients with coexisting MetS and RVH.