Deacetylation of FOXO4 by Sirt1 stabilizes chondrocyte extracellular matrix upon activating SOX9

OBJECTIVE

FOXO4 has essential roles in cellular metabolism and prevents cartilage degeneration in osteoarthritis (OA). Here we aim to provide evidence that deacetylated-FOXO4 stabilizes chondrocyte (CH) extracellular matrix (ECM) related to SOX9 activation.

PATIENTS AND METHODS

We used Chromatin immunoprecipitation (ChIP) and Dual-Luciferase reporter assay to verify that the FOXO4 protein activates SOX9 by binding to its promoter. We cultured human CHs with IL-1β to cause degeneration and supplied Sirt1 protein to deacetylate FOXO4. To confirm the function of FOXO4 and SOX9 during CHs degeneration, we also used the FOXO4 and SOX9 silenced CHs by siRNA transfection as a comparison. Western blot assay was used to analyze the protein level of Sirt1, SOX9, and the acetylated condition of FOXO4. Besides, RT-PCR was used to measure the mRNA level of collagen I/II/X, aggrecan, MMP-13, and ADAMTS-5 for determining the ECM states.

RESULTS

FOXO4 protein transcriptionally activates SOX9 expression by binding to its promoter. Under the IL-1β stimulation, FOXO4 acetyl-lysine rate increased, and the SOX9 protein expression decreased, which was alleviated after the supplement of exogenic Sirt1 protein. Meanwhile, Sirt1 overexpression increased the collagen II and aggrecan and reduced the collagen I, collagen X, MMP-13, and ADAMTS-5 mRNA expression. However, the silencing of FOXO4 abolished the Sirt1 induced SOX9 expression and weakened the ECM production stability. Additionally, SOX9 silencing also alleviated the effect of the Sirt1 supplement on the degenerated CHs, though the FOXO4 was highly deacetylated.

CONCLUSIONS

FOXO4 acetylation aggravates during the degeneration of CHs, and the deacetylation of FOXO4 by Sirt1 could activate the SOX9 expression and result in maintaining the ECM stability of cartilage.

Metabolomics and cancer preventive behaviors in the BC Generations Project

Metabolomics can detect metabolic shifts resulting from lifestyle behaviors and may provide insight on the relevance of changes to carcinogenesis. We used non-targeted nuclear magnetic resonance to examine associations between metabolic measures and cancer preventive behaviors in 1319 participants (50% male, mean age 54 years) from the BC Generations Project. Behaviors were dichotomized: BMI < 25 kg/m², ≥ 5 servings of fruits or vegetables/day, ≤ 2 alcoholic drinks/day for men or 1 drink/day for women and ≥ 30 min of moderate or vigorous physical activity/day. Linear regression was used to estimate coefficients and 95% confidence intervals with a false discovery rate (FDR) of 0.10. Of the 218 metabolic measures, 173, 103, 71 and 6 were associated with BMI, fruits and vegetables, alcohol consumption and physical activity. Notable findings included negative associations between glycoprotein acetyls, an inflammation-related metabolite with lower BMI and greater fruit and vegetable consumption, a positive association between polyunsaturated fatty acids and fruit and vegetable consumption and positive associations between high-density lipoprotein subclasses with lower BMI. These findings provide insight into metabolic alterations in the context of cancer prevention and the diverse biological pathways they are involved in. In particular, behaviors related to BMI, fruit and vegetable and alcohol consumption had a large metabolic impact.

Tomographic imaging with Compton PET modules: ideal case and first implementation

In our previous studies, we demonstrated that the Compton PET module, a layer structure PET detector with side readout, can provide high performance in terms of spatial/energy/timing resolution, as well as high gamma ray detection efficiency. In this study, we investigate how to translate the high performance of the detector module into good quality reconstructed tomographic images. This study is performed using GATE simulation, as well as with physical experiments. Similar detector geometry is used in the simulation and experiment: two identical 4-layer detector modules are placed with face to face distance of 56 mm. In the simulation study, each layer consists of a 1-mm-pitch pixelated crystal array. In the experimental study, each layer is a monolithic crystal, which is virtually binned into 1 mm² cells to group single events according to the gamma ray interaction locations. A customized Derenzo phantom was placed between the two detector modules. By rotating the phantom using a motorized rotary stage, data along lines of response (LORs) at different angles were collected for reconstructing the tomographic image. The same reconstruction algorithm was used for both simulation and experimental studies. The results demonstrate that the simulation study could resolve 0.8 mm rods while the experimental study was able to resolve 1.0 mm rods.

Accurate diagnosis of colorectal cancer based on histopathology images using artificial intelligence

BACKGROUND

Accurate and robust pathological image analysis for colorectal cancer (CRC) diagnosis is time-consuming and knowledge-intensive, but is essential for CRC patients' treatment. The current heavy workload of pathologists in clinics/hospitals may easily lead to unconscious misdiagnosis of CRC based on daily image analyses.

METHODS

Based on a state-of-the-art transfer-learned deep convolutional neural network in artificial intelligence (AI), we proposed a novel patch aggregation strategy for clinic CRC diagnosis using weakly labeled pathological whole-slide image (WSI) patches. This approach was trained and validated using an unprecedented and enormously large number of 170,099 patches, > 14,680 WSIs, from > 9631 subjects that covered diverse and representative clinical cases from multi-independent-sources across China, the USA, and Germany.

RESULTS

Our innovative AI tool consistently and nearly perfectly agreed with (average Kappa statistic 0.896) and even often better than most of the experienced expert pathologists when tested in diagnosing CRC WSIs from multicenters. The average area under the receiver operating characteristics curve (AUC) of AI was greater than that of the pathologists (0.988 vs 0.970) and achieved the best performance among the application of other AI methods to CRC diagnosis. Our AI-generated heatmap highlights the image regions of cancer tissue/cells.

CONCLUSIONS

This first-ever generalizable AI system can handle large amounts of WSIs consistently and robustly without potential bias due to fatigue commonly experienced by clinical pathologists. It will drastically alleviate the heavy clinical burden of daily pathology diagnosis and improve the treatment for CRC patients. This tool is generalizable to other cancer diagnosis based on image recognition.

Search for Coherent Elastic Scattering of Solar ^{8}B Neutrinos in the XENON1T Dark Matter Experiment

We report on a search for nuclear recoil signals from solar ^{8}B neutrinos elastically scattering off xenon nuclei in XENON1T data, lowering the energy threshold from 2.6 to 1.6  keV. We develop a variety of novel techniques to limit the resulting increase in backgrounds near the threshold. No significant ^{8}B neutrinolike excess is found in an exposure of 0.6  t×y. For the first time, we use the nondetection of solar neutrinos to constrain the light yield from 1-2 keV nuclear recoils in liquid xenon, as well as nonstandard neutrino-quark interactions. Finally, we improve upon world-leading constraints on dark matter-nucleus interactions for dark matter masses between 3 and 11  GeV c^{-2} by as much as an order of magnitude.

Hybridization Dynamics in CeCoIn_{5} Revealed by Ultrafast Optical Spectroscopy

We investigate the quasiparticle dynamics in the prototypical heavy fermion CeCoIn_{5} using ultrafast optical pump-probe spectroscopy. Our results indicate that this material system undergoes hybridization fluctuations before the establishment of heavy electron coherence, as the temperature decreases from ∼120  K (T^{†}) to ∼55  K (T^{*}). We reveal that the anomalous coherent phonon softening and damping reduction below T^{*} are directly associated with the emergence of collective hybridization. We also discover a distinct collective mode with an energy of ∼8  meV, which may be experimental evidence of the predicted unconventional density wave. Our findings provide important information for understanding the hybridization dynamics in heavy fermion systems.

Chiral terahertz wave emission from the Weyl semimetal TaAs

Weyl semimetals host chiral fermions with distinct chiralities and spin textures. Optical excitations involving those chiral fermions can induce exotic carrier responses, and in turn lead to novel optical phenomena. Here, we discover strong coherent terahertz emission from Weyl semimetal TaAs, which is demonstrated as a unique broadband source of the chiral terahertz wave. The polarization control of the THz emission is achieved by tuning photoexcitation of ultrafast photocurrents via the photogalvanic effect. In the near-infrared regime, the photon-energy dependent nonthermal current due to the predominant circular photogalvanic effect can be attributed to the radical change of the band velocities when the chiral Weyl fermions are excited during selective optical transitions between the tilted anisotropic Weyl cones and the massive bulk bands. Our findings provide a design concept for creating chiral photon sources using quantum materials and open up new opportunities for developing ultrafast opto-electronics using Weyl physics.

[Prognostic evaluation of nutritional indicators in patients with limited-stage small cell lung cancer]

Objective: To explore the effect of nutritional status pre-and during chemoradiotherapy on the prognosis of patients with limited- stage small cell lung cancer (LS-SCLC). Methods: We retrospectively collected medical records of 172 LS-SCLC patients undergoing concurrent chemoradiotherapy in our hospital from 2000 to 2014, with 126 males and 46 females. The data of complete blood count and hepatic and renal function were collected before initial treatment, before radiotherapy, 4 weeks during radiotherapy, and 1 month after complete of treatment. The prognostic nutritional index(PNI)was calculated. Kaplan-Meier method was used to calculate the survival rate. Log-rank test was performed used to compare the survival differences between groups. Multivariate prognostic analysis was performed using Cox regression model. Results: The median overall survival (OS) was 21 months, with median progression-free survival (PFS) of 11 months. At the beginning of treatment, patients with pre-treatment PNI ≥ 53 had significantly superior OS (median 37 vs 15 months, P=0.001) and PFS (median 16 vs 10 months, P=0.017). Patients with pre-treatment hemoglobin ≥140 g/L and <140 g/L had an median OS of 32 months and 17 months (P=0.019), and median PFS of 16 months and 9 months (P=0.040), respectively. During chemoradiation, patients with elevated hemoglobin had similar median OS compared with those had decreased hemoglobin (27 vs 18 months, P=0.063, but superior median PFS (15 vs 9 months, P=0.017). Multivariate analysis revealed that prophylactic cranial irradiation, pre-treatment hemoglobin ≥140 g/L, and pretreatment PNI ≥53 were independent predictors of OS and PFS in patients with LS-SCLC. Conclusion: Pre-treatment nutritional status and the changes of nutritional status during chemoradiotherapy is significantly associated with the prognosis of patients with limited-stage small cell lung cancer. The patients with better pre-treatment nutritional status have a better prognosis.

Evaluation of Hamamatsu PET imaging modules for dedicated TOF-capable scanners

Time-of-flight (TOF) capability is becoming an important capability offered in both commercial and research PET scanners. Often commercial vendors and laboratory researchers develop and utilize proprietary electronics for their devices. Consequently, it is challenging for independent research groups to develop their own TOF-PET scanners. In this investigation, we tested a prototype scanner consisting of commercially available TOF-capable modules from Hamamatsu Photonics that can be used as building blocks for PET scanners. The scanner consists of a ring of 16 modules, for a total diameter of 26.7 cm. Testing demonstrated that the scanner is capable of sustaining ~1 MHz single counting rate with a peak noise equivalent count rate (NECR) of 117.5 kHz at 75.25 MBq measured with NEMA NU-4 "rat" phantom. Spatial resolution of 2.3 mm 5 mm from the center of the scanner was measured. Energy resolution of 17.2% at 511 keV was measured. Peak sensitivity of 1.28% is reported. All the measurements were performed with energy cuts from 350 to 700 keV Finally, scanner timing resolution was found to be 462 ps. Results from testing of a prototype scanner constructed using newly released TOF-capable detector modules produced by Hamamatsu demonstrated the promise for these devices to create high performance PET system with TOF capabilities.

Periodontal Antibodies and All-Cause and Cardiovascular Disease Mortality

Periodontitis is positively linked to cardiovascular disease (CVD), diabetes, cancer, and increased mortality. Empirically derived clusters of IgG antibodies against 19 selected periodontal microorganisms have been associated with hyperglycemia. We further investigated associations between these serum IgG antibody clusters and all-cause and CVD mortality in a representative US population. Participants free of CVD and cancer and aged ≥40 y at baseline (N = 6,491) from the Third National Health and Nutrition Examination Survey (1988 to 1994) were followed up until December 31, 2011. Antibodies were categorized into 4 clusters: red-green, orange-red, yellow-orange, and orange-blue. Over a 23-y follow-up, 2,702 deaths occurred, including 810 CVD-related deaths. In fully adjusted Cox proportional hazard models, the red-green cluster was positively associated with all-cause mortality (tertile 3 vs. tertile 1: hazard ratio [HR] = 1.43, 95% CI = 1.08 to 1.90, P = 0.015). The yellow-orange cluster was inversely associated with all-cause mortality (tertile 3 vs. tertile 1: HR = 0.78, 95% CI = 0.63 to 0.97, P = 0.028) and CVD mortality (tertile 2 vs. tertile 1: HR = 0.57, 95% CI = 0.42 to 0.77, P = 0.005). The orange-blue cluster (composed of antibodies against Eubacterium nodatum and Actinomyces naeslundii) was inversely associated with all-cause mortality (tertile 3 vs. tertile 1: HR = 0.65, 95% CI = 0.55 to 0.78, P < 0.0001) and CVD mortality (tertile 3 vs. tertile 1: HR = 0.65, 95% CI = 0.47 to 0.88, P = 0.007). These antibodies could predict prognosis or be potential intervention targets to prevent systemic effects of periodontal disease if further studies establish a causal relationship.

Tenascin-C expression contributes to pediatric brainstem glioma tumor phenotype and represents a novel biomarker of disease

Diffuse intrinsic pontine glioma (DIPG), an infiltrative, high grade glioma (HGG) affecting young children, has the highest mortality rate of all pediatric cancers. Despite treatment, average survival is less than twelve months, and five-year survival under 5%. We previously detected increased expression of Tenascin-C (TNC) protein in DIPG cerebrospinal fluid and tumor tissue relative to normal specimens. TNC is an extracellular matrix (ECM) glycoprotein that mediates cell-matrix interactions, guides migrating neurons during normal brain development and is thought to maintain the periventricular stem cell niche in the developing brain. Tumor TNC expression is reported in adult glioma and other cancers. However, the pattern and effects of TNC expression in DIPG has not been previously explored. Here, we characterize TNC expression in patient derived pediatric supratentorial HGG (n = 3) and DIPG (n = 6) cell lines, as well as pediatric glioma tumor (n = 50) and normal brain tissue specimens (n = 3). We found tumor specific TNC gene and protein overexpression that directly correlated with higher tumor grade (WHO III and IV, p = 0.05), H3K27 M mutation (p = 0.012), shorter progression free survival (p = 0.034), and poorer overall survival (0.041) in association with these factors. TNC knockdown via lentiviral shRNA transfection of HGG (n = 1) and DIPG (n = 3) cell lines resulted in decreased cell proliferation, migration, and invasion in vitro (p < 0.01), while TNC cDNA transfection resulted in increased cell migration, invasion and proliferation (p < 0.01) as well as altered cell morphology in H3K27 M mutant DIPG lines. Whole transcriptome sequencing analysis (RNA-Seq) on DIPG (n = 3) and HGG (n = 2) cell lines after TNC cDNA, shRNA, and empty vector control transfection revealed the effects of TNC expression level on global gene expression profiles. Together, our findings reveal TNC expression in DIPG in association with H3K27 M mutation and VEGF signaling, and suggest that TNC may contribute to DIPG tumor phenotype, and serve as a clinically detectable biomarker for DIPG.

Direct observation of magnetic contrast obtained by photoemission electron microscopy with deep ultra-violet laser excitation

Magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD) have been investigated in a photoemission electron microscopy (PEEM) system excited by a deep ultra-violet (DUV) laser (with λ = 177.3 nm and hυ = 7.0 eV) for the first time. High resolution PEEM magnetic images (down to 43.2 nm) were directly obtained on a (001)-oriented magnetic FePt film surface with a circularly-polarized light under normal incidence. Furthermore, a stepped Cr seeding layer was applied to induce the formation of large-area epitaxial FePt films with (001) and (111) two orientations, where MLD with large asymmetry was observed in the transition area of two phases. It demonstrates that DUV laser can be a powerful source for high resolution magnetic imaging in the laboratory in absence of synchrotron facilities.