O-GlcNAcylation regulates long-chain fatty acid metabolism by inhibiting ACOX1 ubiquitination-dependent degradation.

BACKGROUND: Cold as a common environmental stress, causes increased heat production, accelerated metabolism and even affects its production performance. How to improve the adaptability of the animal organism to cold has been an urgent problem. As a key hub of lipid metabolism, the liver can regulate lipid metabolism to maintain energy balance, and O-GlcNAcylation is a kind of important PTMs, which participates in a variety of signaling and mechanism regulation, and at the same time, is very sensitive to changes in stress and nutritional levels, and is the body's "stress receptors" and "nutrient receptors". Therefore, the aim of this experiment was to investigate the effect of cold-induced O-GlcNAcylation on hepatic lipid metabolism, and to explore the potential connection between O-GlcNAcylation and hepatic lipid metabolism. METHODS: To investigate the loss of O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) and the precise impacts of additional cold-induced circumstances on liver mass, shape, and metabolic profile, C57 mice were used as an animal model. Using the protein interactions approach, the mechanism of O-GlcNAcylation, as well as the degradation pathway of acyl-Coenzyme A oxidase 1 (ACOX1), were clarified. Additional in vitro analyses of oleic acid (OA) and OGT inhibitor tetraoxan (Alloxan) (Sigma, 2244-11-3) on lipid breakdown in AML-12 cells. RESULTS: In C57BL/6 mice, deletion of O-GlcNAcylation disrupted lipid metabolism, caused hepatic edema and fibrosis, and altered mitochondrial apoptosis. This group of modifications was made worse by cold induction. The accumulation of medium- and long-chain fatty acids is a hallmark of lipolysis, which is accelerated by the deletion of O-GlcNAcylation, whereas lipid synthesis is slowed down. The association between ACOX1 and OGT at the K48 gene precludes ubiquitinated degradation.

Accurate and Rapid Detection of Peritoneal Metastasis from Gastric Cancer by AI-Assisted Stimulated Raman Molecular Cytology.

Peritoneal metastasis (PM) is the mostcommon form of distant metastasis and one of the leading causes of death in gastriccancer (GC). For locally advanced GC, clinical guidelines recommend peritoneal lavage cytology for intraoperative PM detection. Unfortunately, current peritoneal lavage cytology is limited by low sensitivity (<60%). Here the authors established the stimulated Raman molecular cytology (SRMC), a chemical microscopy-based intelligent cytology. The authors firstly imaged 53 951 exfoliated cells in ascites obtained from 80 GC patients (27 PM positive, 53 PM negative). Then, the authors revealed 12 single cell features of morphology and composition that are significantly different between PM positive and negative specimens, including cellular area, lipid protein ratio, etc. Importantly, the authors developed a single cell phenotyping algorithm to further transform the above raw features to feature matrix. Such matrix is crucial to identify the significant marker cell cluster, the divergence of which is finally used to differentiate the PM positive and negative. Compared with histopathology, the gold standard of PM detection, their SRMC method could reach 81.5% sensitivity, 84.9% specificity, and the AUC of 0.85, within 20 minutes for each patient. Together, their SRMC method shows great potential for accurate and rapid detection of PM from GC.

One-stop combined CT angiography of coronary and craniocervical arteries: recommended as the first examination for patients suspected of coronary or craniocervical artery disease.

OBJECTIVES: To investigate the potential diagnostic value of one-stop combined CT angiography (CTA) as the first examination for patients suspected of coronary artery disease (CAD) or craniocervical artery disease (CCAD), and compare its clinical performance with two consecutive CTA scans. METHODS: Patients with suspected but unconfirmed CAD or CCAD were prospectively enrolled and grouped randomly to undergo coronary and craniocervical CTA using the combined protocol (group 1) or the consecutive protocol (group 2). Diagnostic findings were evaluated for both the targeted and non-targeted regions. The objective image quality, overall scan time, radiation dose, and contrast medium dosage were compared between the two groups. RESULTS: Each group enrolled 65 patients. A substantial number of lesions were found in non-targeted regions, which was 44/65 (67.7%) by patients for group 1 and 41/65 (63.1%) for group 2, reiterating the necessity of extending the scan coverage. Specifically, lesions in non-targeted regions were detected more often for patients suspected of CCAD than for those suspected of CAD (71.4% vs 61.7%). With 21.5% (~51.1 s) reduction of scan time and 21.8% (~20.8 mL) less contrast medium as compared to the consecutive protocol, high-quality images were obtained by the combined protocol. CONCLUSIONS: One-stop combined CTA enables effective detection of lesions in non-targeted regions at a lower cost of scan time and contrast medium than two separate examinations and is thus worth taking as the first examination for patients suspected of CAD or CCAD. KEY POINTS: • Extending the scan range for coronary or craniocervical CTA has the potential to reveal lesions in non-targeted regions. • One-stop combined CTA as enabled on high-speed wide-detector CT delivers high-quality images at a lower cost of contrast medium and operational time than two consecutive CTA scans. • Patients with suspected but unconfirmed CAD or CCAD may benefit from the one-stop combined CTA in the first examination.

The role of altered lipid composition and distribution in liver fibrosis revealed by multimodal nonlinear optical microscopy.

Intracellular lipid accumulation is commonly seen in fibrotic livers, but its exact role in liver fibrosis remains elusive. Here, we established a multimodal nonlinear optical microscopy to quantitatively map distribution of biomolecules in fibrotic livers. Our data revealed that unsaturated triglycerides were predominantly accumulated in central vein area during liver fibrosis but not in portal vein area. Moreover, the lipid homeostasis was remarkably dysregulated in the late-stage compared to the early-stage fibrosis, including increased unsaturated triglycerides with decreased lipid unsaturation degree and decreased membrane fluidity. Such alterations were likely due to up-regulated lipogenesis, desaturation, and peroxidation, which consequently led to endoplasmic reticulum stress and cell death. Inspiringly, injured hepatocyte could be rescued by remodeling lipid homeostasis via either supply of unsaturated fatty acids or enhancement of membrane fluidity. Collectively, our study improves current understanding of the role of lipid homeostasis in fibrosis and open opportunities for treatment.

O-GlcNAcylation of SIRT1 Protects against Cold Stress-Induced Skeletal Muscle Damage via Amelioration of Mitochondrial Homeostasis.

Cold stress disturbs cellular metabolic and energy homeostasis, which is one of the causes of stress-induced illnesses. O-GlcNAcylation is a nutrient-sensing pathway involved in a myriad of cellular processes. It plays a key role in metabolic homeostasis. Nevertheless, a specific sensing mechanism linking skeletal muscle to O-GlcNAcylation in cold stress is unknown. In this study, O-GlcNAcylation of SIRT1 was targeted to explore the mechanism of skeletal muscle adaptation to cold stress. Ogt mKO aggravated skeletal muscle fibrosis induced by cold stress. At the same time, Ogt gene deletion accelerated the homeostasis imbalance and oxidative stress of skeletal muscle mitochondria induced by cold stress. In vitro results showed that inhibition of SIRT1's O-GlcNAcylation accelerated mild hypothermia induced mitochondrial homeostasis in mouse myogenic cells (C2C12 cells). However, overexpression of SIRT1's O-GlcNAcylation improved the above phenomena. Thus, these results reveal a protective role of OGT-SIRT1 in skeletal muscle's adaptation to cold stress, and our findings will provide new avenues to combat stress-induced diseases.

Identification of Q-Markers from Hedan Tablet by employing "spider-web" mode and taking compounds' hepatotoxicity into account.

Objective: Due to the complicated compounds and the synergistic effect of multi-compounds, the quality control and assessment of Chinese materia medica (CMM) encounters a great challenge about how to identify the key compounds, which are directly correlated with its efficacy and safety. On the guidance of study on quality marker (Q-Marker), identification of Q-Markers was performed from Hedan Tablet (HDT) by the aid of the "spider-web" mode and hepatotoxicity evaluation derived from our previous researches and literatures. Methods: By the established ultra performance liquid chromatography with photodiode array detector (UPLC-PDA) method, online UPLC-DPPH· and offline antioxidant assay, 21 candidate compounds of HDT were systematically investigated and comprehensively evaluated by the "spider-web" mode for them properties of Q-Marker based on "content-stability-activity". In addition, the Q-Markers related with hepatotoxicity based on our previous researches and literatures were identified. Results: Salvianolic acid B (SaB), quercetin-3-O-glucuronide (Qug), isoquercitrin (IQ) and hyperoside (Hyp) were adopted as the preferable Q-Markers of HDT according to the shaded area (A) of tested compounds in "spider-web" mode. Psoralen (Ps), isopsoralen (IP), psoralenoside (PO) and isopsoralenoside (IPO) were also strongly recommended as Q-Markers closely related with safety by considering hepatotoxicity of the accumulated Ps and IP and conversion between glycoside (PO and IPO) and aglycone (Ps and IP). Conclusion: This study provided scientific evidence for quality control and assessment of HDT, and also provided a meaningful reference for application of Q-Markers in CMM.

Noninvasive temperature monitoring for dual-modal tumor therapy based on lanthanide-doped up-conversion nanocomposites.

Accurate treatment of photothermal therapy (PTT) is crucial to avoid the unnecessary injury of normal cells and tissues. Therefore the real-time temperature monitoring in the PTT process has drawn more and more attention in recent years. Herein, we designed and prepared one kind of lanthanide (Ln3+)-doped up-conversion nanocomposites with multi-functions, which can not only provide temperature feedback in PTT process, but also play the photodynamic therapy (PDT) function for the synergistic effect of tumor therapy. Based on NaYF4:Yb, Er up-conversion nanoparticles (UCNPs), mesoporous SiO2 was modified on the surface combined with photosensitizer Chlorin e6 (Ce6) molecules, which could be excited by red emission of Er3+ under the 980 nm laser. Cit-CuS NPs were further linked on the surface of the composite served as photothermal conversion agent, therefore, the temperature of the PTT site can be monitored by recording the ratio of I525/I545 of green emissions, especially within the physiological range. Based on the guidance obtained from spectral experiments, we further investigated the dual-modal therapy effect both in vitro and in vivo, respectively, and acquired decent results.

Multi-parameters monitoring during traditional Chinese medicine concentration process with near infrared spectroscopy and chemometrics.

As a powerful process analytical technology (PAT) tool, near infrared (NIR) spectroscopy has been widely used in real-time monitoring. In this study, NIR spectroscopy was applied to monitor multi-parameters of traditional Chinese medicine (TCM) Shenzhiling oral liquid during the concentration process to guarantee the quality of products. Five lab scale batches were employed to construct quantitative models to determine five chemical ingredients and physical change (samples density) during concentration process. The paeoniflorin, albiflorin, liquiritin and samples density were modeled by partial least square regression (PLSR), while the content of the glycyrrhizic acid and cinnamic acid were modeled by support vector machine regression (SVMR). Standard normal variate (SNV) and/or Savitzkye-Golay (SG) smoothing with derivative methods were adopted for spectra pretreatment. Variable selection methods including correlation coefficient (CC), competitive adaptive reweighted sampling (CARS) and interval partial least squares regression (iPLS) were performed for optimizing the models. The results indicated that NIR spectroscopy was an effective tool to successfully monitoring the concentration process of Shenzhiling oral liquid.