Real-Time Monitoring of Tyrosine Hydroxylase Activity with a Ratiometric Fluorescent Probe.

Parkinson's disease (PD) represents the second most widespread neurodegenerative disease, and early monitoring and diagnosis are urgent at present. Tyrosine hydroxylase (TH) is a key enzyme for producing dopamine, the levels of which can serve as an indicator for assessing the severity and progression of PD. This renders the specific detection and visualization of TH a strategically vital way to meet the above demands. However, a fluorescent probe for TH monitoring is still missing. Herein, three rationally designed wash-free ratiometric fluorescent probes were proposed. Among them, TH-1 exhibited ideal photophysical properties and specific dual-channel bioimaging of TH activity in SH-SY5Y nerve cells. Moreover, the probe allowed for in vivo imaging of TH activity in zebrafish brain and living striatal slices of mice. Overall, the ratiometric fluorescent probe TH-1 could serve as a potential tool for real-time monitoring of PD in complex biosystems.

Study of ultraviolet light emitting diodes with InGaN quantum dots and lattice matched superlattice electron blocking layers.

Ultraviolet light emitting diodes (UV-LEDs) face the challenges including insufficient hole injection and severe electron leakage. Quantum dots (QDs) have been proven to provide three-dimensionally localized states for carriers, thereby enhancing carrier confinement. Therefore, UV-LEDs employing InGaN QDs are designed and studied in this paper. The APSYs software is used to simulate UV-LEDs. Simulation results indicate that the QDs effectively improve the electron and hole concentration in the active region. However, UV-LEDs with QDs experience efficiency droop due to serious electron leakage. What's more, the lattice mismatch between last quantum barrier (LQB) and electron blocking layer (EBL) leads to the polarization field, which induces the downward band bending at the LQB/EBL interface and reduces effective barrier height of EBL for electrons. The AlInGaN/AlInGaN lattice matched superlattice (LMSL) EBL is designed to suppress electron leakage while mitigating lattice mismatch between LQB and EBL. The results indicate that the utilization of QDs and LMSL EBL contributes to increasing the electron and hole concentration in the active region, reducing electron leakage, enhancing radiative recombination rate, and reducing turn-on voltage. The efficiency droop caused by electron leakage is mitigated. When the injection current is 120 mA, the external quantum efficiency is increased to 9.3% and the output power is increased to 38.3 mW. This paper provides a valuable reference for addressing the challenges of insufficient hole injection and severe electron leakage.

Spontaneous Skyrmion Bubbles in an Iron-Silicon Alloy with Uniaxial Magnetic Anisotropy.

The magnetic skyrmions exhibit intriguing topological behaviors, holding promise for future applications in the realm of spintronic devices. Despite recent advancements, achieving spontaneous magnetic skyrmions and topological transitions in magnets featuring uniaxial magnetic anisotropy, particularly at elevated temperatures (>100 K), remains a challenging endeavor. Here, single-crystal Fe5Si3 nanorods with the central symmetry and uniaxial magnetic anisotropy were successfully synthesized on a mica substrate through chemical vapor deposition, which exhibit a high Curie temperature (TC) of about 372 K. The real-time observation, facilitated by Lorentz transmission electron microscopy, revealed the spontaneous formation of magnetic skyrmions and evolution of domains in focused ion beam-prepared Fe5Si3 thin foils. Moreover, Fe5Si3 device transport measurements expose notable magnetoresistance (MR) effects, enabling the interchange between positive and negative MR across specific temperature settings. These results offer various potential avenues for exploring diverse topological spin textures and their formation mechanisms, indicating inventive applications for iron-silicon alloy in the realm of spintronics.

Lactate-Induced CCL8 in Tumor-Associated Macrophages Accelerates the Progression of Colorectal Cancer through the CCL8/CCR5/mTORC1 Axis.

Tumor-associated macrophages (TAMs) play a pivotal role in shaping the tumor microenvironment. Lactic acid (LA) has been identified as an influential factor in promoting immune escape and tumor progression. However, the mechanisms through which LA modulates TAMs in colorectal cancer (CRC) remain poorly understood. We used qRT-PCR to quantify the expression of LA-related genes (LDHA and LAMP2) in CRC tumor tissues and adjacent nontumor tissues (n = 64). The biological effects and mechanisms of LA on macrophages and tumors were evaluated via qRT-PCR, Western blot, RNA-seq, wound healing assay, colony formation assay in vitro, and allograft mouse tumor models in vivo. We found the expression of LDHA and LAMP2 was highly elevated in the tumor regions and positively associated with a poor clinical stage of CRC. A high concentration of LA was generated under hypoxia; it could promote tumor progression and metastasis with the involvement of macrophages. The inhibition of LA release impaired this protumor phenomenon. Mechanically, LA induced M2 macrophages through the AKT/ERK signaling pathway; subsequently, M2 macrophages secreted CCL8 and facilitated the proliferation and metastasis of CRC cells by activating the CCL8/CCR5/mTORC1 axis. This effect was inhibited by the antagonist or knockdown of CCR5. In conclusion, lactate-induced CCL8 in TAMs accelerated CRC proliferation and metastasis through the CCL8/CCR5/mTORC1 axis.

Lactate receptor GPR81 drives breast cancer growth and invasiveness through regulation of ECM properties and Notch ligand DLL4.

BACKGROUND: The lactate receptor GPR81 contributes to cancer development through unclear mechanisms. Here, we investigate the roles of GPR81 in three-dimensional (3D) and in vivo growth of breast cancer cells and study the molecular mechanisms involved. METHODS: GPR81 was stably knocked down (KD) in MCF-7 human breast cancer cells which were subjected to RNA-seq analysis, 3D growth, in situ- and immunofluorescence analyses, and cell viability- and motility assays, combined with KD of key GPR81-regulated genes. Key findings were additionally studied in other breast cancer cell lines and in mammary epithelial cells. RESULTS: GPR81 was upregulated in multiple human cancer types and further upregulated by extracellular lactate and 3D growth in breast cancer spheroids. GPR81 KD increased spheroid necrosis, reduced invasion and in vivo tumor growth, and altered expression of genes related to GO/KEGG terms extracellular matrix, cell adhesion, and Notch signaling. Single cell in situ analysis of MCF-7 cells revealed that several GPR81-regulated genes were upregulated in the same cell clusters. Notch signaling, particularly the Notch ligand Delta-like-4 (DLL4), was strikingly downregulated upon GPR81 KD, and DLL4 KD elicited spheroid necrosis and inhibited invasion in a manner similar to GPR81 KD. CONCLUSIONS: GPR81 supports breast cancer aggressiveness, and in MCF-7 cells, this occurs at least in part via DLL4. Our findings reveal a new GPR81-driven mechanism in breast cancer and substantiate GPR81 as a promising treatment target.

Attentional suppression of weight-related distractors among females with weight dissatisfaction.

Although many studies have investigated attentional biases toward weight-related information among individuals with weight dissatisfaction, the mechanisms underlying the processing of task-irrelevant and spatial-irrelevant weight-related information as distractors remain unclear. Participants were assigned to groups according to their levels of weight dissatisfaction to address this question. Participants with high weight dissatisfaction (HWD) were assigned to the experimental group; those with low weight dissatisfaction (LWD) were assigned to a control group. By recording event-related potentials during a visual search task along the median vertical line, fatness-related/thinness-related/neutral words and scrambled strokes were presented horizontally in pairs as task-irrelevant distractors. The results showed that intact words facilitated fast attentional orienting compared to scrambled strokes, as revealed by the significant N2pc for all types of intact words for both the HWD and LWD groups. More importantly, only fatness- and thinness-related words elicited the evident PD in the HWD group, and the PD amplitudes were larger in the HWD group compared to the LWD group. These findings suggest that weight-related distractors were actively suppressed after initial attentional orienting among females with HWD. This reveals the mechanisms of attentional biases toward weight-related information among females with HWD and contributes to the model of the cognitive-behavioral theory of body image disturbance. These results may help enhance prevention and interventions for reducing weight dissatisfaction.

Attentional biases toward auditory weight-related information among females with weight dissatisfaction.

Although there is substantial evidence of visual attentional biases in processing weight-related information among individuals with weight dissatisfaction, few studies have examined auditory attentional biases in these individuals. The identification of attentional biases may provide an impetus for interventions to reduce distress, negative body image, and pathological eating patterns among weight-dissatisfied individuals. Therefore, the present study aimed to investigate the attentional biases, as well as the neural consequences, toward auditory weight-related information among weight-dissatisfied young females. In this experiment, young female participants were assigned to an experimental group with high weight dissatisfaction (HWD) and a control group with low weight dissatisfaction (LWD) according to the levels of weight dissatisfaction. Using a spatial cueing paradigm, auditory fatness-related, thinness-related, and neutral household words were presented laterally as cue stimuli, followed by visual stimuli presented at either the cued or uncued location. The results revealed that auditory fatness-related words elicited significantly larger N2ac amplitudes than auditory thinness-related and neutral words in the HWD group. However, for the LWD group, thinness-related words elicited a significantly larger N2ac than fatness-related and neutral words. These results suggest an orienting attentional bias toward auditory fatness-related body words among females with HWD and an orienting attentional bias toward auditory thinness-related words among females with LWD.

ANXA2 as a novel substrate of FBXW7 promoting esophageal squamous cell carcinoma via ERK phosphorylation.

Our recent study suggests that FBXW7 loss of function plays a critical function in esophageal cancer. However, the mechanism of FBXW7 in promoting esophageal cancer is still unclear. Here, we explored the interaction protein of FBXW7 by screening of GST-pulldown and LC-MS/MS analysis in esophageal squamous cell carcinoma (ESCC) and identified ANXA2 as a potential target of FBXW7. FBXW7 loss of function could restore the expression of ANXA2 and promote the malignant biological characteristics of ESCC cells in vitro. Up-regulation of ANXA2 enhances the ERK pathway in ESCC. Furthermore, the 23rd tyrosine residue of ANXA2, phosphorylated by SRC, was regarded as playing important roles in the FBXW7-related degradation system. In clinical samples, we found that ANXA2 had high expression in ESCC tissues. High ANXA2 was associated with poor tumor staging. More importantly, we designed a combination regimen including SCH779284, a clinical ERK inhibitor against the phosphorylation of EKR and siRNA targeting ANXA2 by intratumor injection, and it produced potent inhibitory effects on the growth of xenograft tumors in vivo. In conclusion, this study provided evidence that FBXW7 loss of function could promote esophageal cancer through ANXA2 overexpression, and this novel regulation pathway may be used as an efficient target for ESCC treatment.

Crosstalk between tumor acidosis, p53 and extracellular matrix regulates pancreatic cancer aggressiveness.

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy with minimal treatment options and a global rise in prevalence. PDAC is characterized by frequent driver mutations including KRAS and TP53 (p53), and a dense, acidic tumor microenvironment (TME). The relation between genotype and TME in PDAC development is unknown. Strikingly, when wild type (WT) Panc02 PDAC cells were adapted to growth in an acidic TME and returned to normal pH to mimic invasive cells escaping acidic regions, they displayed a strong increase of aggressive traits such as increased growth in 3-dimensional (3D) culture, adhesion-independent colony formation and invasive outgrowth. This pattern of acidosis-induced aggressiveness was observed in 3D spheroid culture as well as upon organotypic growth in matrigel, collagen-I and combination thereof, mimicking early and later stages of PDAC development. Acid-adaptation-induced gain of cancerous traits was further increased by p53 knockout (KO), but only in specific extracellular matrix (ECM) compositions. Akt- and Transforming growth factor-ß (TGFß) signaling, as well as expression of the Na+ /H+ exchanger NHE1, were increased by acid adaptation. Whereas Akt inhibition decreased spheroid growth regardless of treatment and genotype, stimulation with TGFßI increased growth of WT control spheroids, and inhibition of TGFß signaling tended to limit growth under acidic conditions only. Our results indicate that a complex crosstalk between tumor acidosis, ECM composition and genotype contributes to PDAC development. The findings may guide future strategies for acidosis-targeted therapies.

Chronic acidosis rewires cancer cell metabolism through PPARα signaling.

The mechanisms linking tumor microenvironment acidosis to disease progression are not understood. Here, we used mammary, pancreatic, and colon cancer cells to show that adaptation to growth at an extracellular pH (pHe ) mimicking acidic tumor niches is associated with upregulated net acid extrusion capacity and elevated intracellular pH at physiological pHe , but not at acidic pHe . Using metabolic profiling, shotgun lipidomics, imaging and biochemical analyses, we show that the acid adaptation-induced phenotype is characterized by a shift toward oxidative metabolism, increased lipid droplet-, triacylglycerol-, peroxisome content and mitochondrial hyperfusion. Peroxisome proliferator-activated receptor-α (PPARA, PPARα) expression and activity are upregulated, at least in part by increased fatty acid uptake. PPARα upregulates genes driving increased mitochondrial and peroxisomal mass and ß-oxidation capacity, including mitochondrial lipid import proteins CPT1A, CPT2 and SLC25A20, electron transport chain components, peroxisomal proteins PEX11A and ACOX1, and thioredoxin-interacting protein (TXNIP), a negative regulator of glycolysis. This endows acid-adapted cancer cells with increased capacity for utilizing fatty acids for metabolic needs, while limiting glycolysis. As a consequence, the acid-adapted cells exhibit increased sensitivity to PPARα inhibition. We conclude that PPARα is a key upstream regulator of metabolic changes favoring cancer cell survival in acidic tumor niches.

Single-Cell RNA-Seq Identifies Dynamic Cardiac Transition Program from ADCs Induced by Leukemia Inhibitory Factor.

Adipose-derived cells (ADCs) from white adipose tissue are promising stem cell candidates because of their large regenerative reserves and the potential for cardiac regeneration. However, given the heterogeneity of ADC and its unsolved mechanisms of cardiac acquisition, ADC-cardiac transition efficiency remains low. In this study, we explored the heterogeneity of ADCs and the cellular kinetics of 39,432 single-cell transcriptomes along the leukemia inhibitory factor (LIF)-induced ADC-cardiac transition. We identified distinct ADC subpopulations that reacted differentially to LIF when entering the cardiomyogenic program, further demonstrating that ADC-myogenesis is time-dependent and initiates from transient changes in nuclear factor erythroid 2-related factor 2 (Nrf2) signaling. At later stages, pseudotime analysis of ADCs navigated a trajectory with 2 branches corresponding to activated myofibroblast or cardiomyocyte-like cells. Our findings offer a high-resolution dissection of ADC heterogeneity and cell fate during ADC-cardiac transition, thus providing new insights into potential cardiac stem cells.

Serum Tenascin-C and Alarin Levels Are Associated with Cardiovascular Diseases in Type 2 Diabetes Mellitus.

Background: Tenascin-C (TNC), an extracellular matrix glycoprotein, is elevated in inflammatory and cardiovascular pathologies, whereas alarin, a novel orexigenic peptide, participates in insulin resistance and glycometabolism. The roles of these molecules in individuals with cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM), clinical conditions associating with metabolic disorders, and chronic inflammation, remain controversial. Our study aimed at determining the potential role of TNC and alarin in CVD adult patients with T2DM. Methods: This was a cross-sectional study. Basic and clinical information for 250 patients with T2DM were analyzed. Based on their cardiovascular disease status, participants were assigned into the CVD and non-CVD groups. Serum TNC and alarin levels were assessed by enzyme-linked immunosorbent assay (ELISA). Results: Serum TNC and alarin concentrations in the CVD group were significantly higher than those of the non-CVD group. Moreover, serum TNC levels were positively correlated with age, waist circumference, and waist-hip ratio; however, they were negatively correlated with TC, LDL-C, and eGFR levels. Alarin levels were positively correlated with BMI, waist circumference, and hip circumference. In logistic regression models, TNC and alarin were also established to be independent determinants for CVD in T2DM patients and their increases were associated with CVD severity. Receiver operating characteristic (ROC) curve analysis showed that the area under curve (AUC) values for TNC and alarin were 0.68 and 0.67, respectively. TNC and alarin were good predictors of CVD occurrence. When the cutoff value for TNC was 134.05 pg/mL, its sensitivity was 69.47% while its specificity was 61.29%. When the cutoff value for alarin was 142.69 pg/mL, sensitivity and specificity were 38.95% and 90.97%, respectively. Conclusion: Elevated TNC and alarin levels are independently associated with the occurrence and severity of CVD in T2DM individuals. Therefore, these two biomarkers are potential diagnostic and prognostic indicators for CVD in diabetics.

Progenitor cells from brown adipose tissue undergo neurogenic differentiation.

Multipotent cells derived from white adipose tissue have been shown to differentiate into multiple lineages including neurogenic lineages. However, the high innervation of brown adipose tissue by the sympathetic nervous system suggest it might be a better source of neural precursor cells. To investigate potential differences between white and brown progenitors, we cultured white and brown dedifferentiated fat (wDFAT and brDFAT) cells from mouse and human adipose tissue and compared marker expression of neural precursors, and neuronal and glial cells, using fluorescence-activated cell sorting, bright-field imaging, immunofluorescence, and RNA analysis by qPCR. The results showed that both wDFAT and brDFAT cells had the capacity to generate neuronal and glial-like cells under neurogenic conditions. However, the brDFAT cells exhibited enhanced propensity for neurogenic differentiation. The neurogenic cells were at least in part derived from Adiponectin-expressing cells. TdTomato-expressing cells derived from Adiponectin (Adipoq) Cre ERT2 -tdTomato flox/flox mice gave rise to individual cells and cell clusters with neurogenic characteristics. Moreover, human brDFAT cells demonstrated a similar ability to undergo neurogenic differentiation after treatment with neurogenic medium, as assessed by immunofluorescence and qPCR. Together, our results support that brDFAT cells have ability to undergo neurogenic differentiation.

Combinational Chemoimmunotherapy for Breast Cancer by Codelivery of Doxorubicin and PD-L1 siRNA Using a PAMAM-Incorporated Liposomal Nanoplatform.

Chemoimmunotherapy can synergistically enhance the therapeutic effects and decrease the side effects by a combined method. However, the effective targeted codelivery of various chemotherapeutic agents and siRNAs remains challenging. Although nanomedicine-based chemoimmunotherapy has shown great potential in cancer treatment in recent years, further effort is needed to simplify the nanocarrier designs and maintain their effective functions. Here, we report a simple but robust multifunctional liposomal nanocarrier that contains a pH-sensitive liposome (LP) shell and a dendritic core for tumor-targeted codelivery of programmed cell death ligand 1 (PD-L1) siRNA and doxorubicin (DOX) (siPD-L1@PM/DOX/LPs). siPD-L1@PM/DOX/LPs had a suitable particle size and zeta potential, excellent stability in serum, and pH-sensitive drug release in vitro. They exhibited significant cell proliferation inhibition compared to free DOX and DOX-loaded LPs and could escape endosomes, effectively release siRNA into the cytoplasm of MCF-7 cells, and significantly reduce the PD-L1 expression on tumor cells. In vivo imaging confirmed high accumulation of siPD-L1@PM/DOX/LPs at the tumor site. More importantly, compared with siPD-L1@PM/LPs or DOX alone, siPD-L1@PM/DOX/LPs were more effective in inhibiting tumor growth and activating cytotoxic T cells in vivo. In conclusion, this nanocarrier may hold promise as a codelivery nanoplatform to improve the treatment of various solid tumors.

Design, optimization and evaluation of a microemulsion-based hydrogel with high malleability for enhanced transdermal delivery of levamisole.

The objective of the present study was to prepare and evaluate a microemulsion-based hydrogel with high malleability as a transdermal delivery carrier for levamisole (LMS). A pseudo-ternary phase diagram and D-optimal mixture design were utilized to screen and optimize the microemulsion, and the formulation comprised 7.5% MaisineTM35-1, 33% Smix and 59.5% water. The microemulsion was physically stable with an average size of 19.3 ± 0.1 nm and zeta potential of -3.84 ± 0.05 mV. Moreover, a highly malleable alginate-boronic acid (alginate-BA) gel was prepared and could come into close contact with highly curved skin. The optimized microemulsion was loaded into alginate-BA gel and subjected to ex vivo and in vivo investigation. The microemulsion-based gel had desirable characterization, good stability and negligible skin irritation. The results of ex vivo permeation study showed that LMS achieved a significantly higher cumulative amount from the LMS-loaded microemulsion-based gel than that from the LMS-gel. The pharmacokinetic study showed a twofold increase in relative bioavailability compared to the commercial liniment. These results provide insight into the capability of the developed malleable microemulsion-based gel to enhance the transdermal permeation and bioavailability of LMS.

Contributions of the Endothelium to Vascular Calcification.

Vascular calcification (VC) increases morbidity and mortality and constitutes a significant obstacle during percutaneous interventions and surgeries. On a cellular and molecular level, VC is a highly regulated process that involves abnormal cell transitions and osteogenic differentiation, re-purposing of signaling pathways normally used in bone, and even formation of osteoclast-like cells. Endothelial cells have been shown to contribute to VC through a variety of means. This includes direct contributions of osteoprogenitor cells generated through endothelial-mesenchymal transitions in activated endothelium, with subsequent migration into the vessel wall. The endothelium also secretes pro-osteogenic growth factors, such as bone morphogenetic proteins, inflammatory mediators and cytokines in conditions like hyperlipidemia, diabetes, and renal failure. High phosphate levels caused by renal disease have deleterious effects on the endothelium, and induction of tissue non-specific alkaline phosphatase adds to the calcific process. Furthermore, endothelial activation promotes proteolytic destruction of the internal elastic lamina that serves, among other things, as a stabilizer of the endothelium. Appropriate bone mineralization is highly dependent on active angiogenesis, but it is unclear whether the same relationship exists in VC. Through its location facing the vascular lumen, the endothelium is the first to encounter circulating factor and bone marrow-derived cells that might contribute to osteoclast-like versus osteoblast-like cells in the vascular wall. In the same way, the endothelium may be the easiest target to reach with treatments aimed at limiting calcification. This review provides a brief summary of the contributions of the endothelium to VC as we currently know them.

Shifting osteogenesis in vascular calcification.

Transitions between cell fates commonly occur in development and disease. However, reversing an unwanted cell transition in order to treat disease remains an unexplored area. Here, we report a successful process of guiding ill-fated transitions toward normalization in vascular calcification. Vascular calcification is a severe complication that increases the all-cause mortality of cardiovascular disease but lacks medical therapy. The vascular endothelium is a contributor of osteoprogenitor cells to vascular calcification through endothelial-mesenchymal transitions, in which endothelial cells (ECs) gain plasticity and the ability to differentiate into osteoblast-like cells. We created a high-throughput screening and identified SB216763, an inhibitor of glycogen synthase kinase 3 (GSK3), as an inducer of osteoblastic-endothelial transition. We demonstrated that SB216763 limited osteogenic differentiation in ECs at an early stage of vascular calcification. Lineage tracing showed that SB216763 redirected osteoblast-like cells to the endothelial lineage and reduced late-stage calcification. We also found that deletion of GSK3ß in osteoblasts recapitulated osteoblastic-endothelial transition and reduced vascular calcification. Overall, inhibition of GSK3ß promoted the transition of cells with osteoblastic characteristics to endothelial differentiation, thereby ameliorating vascular calcification.

The diagnostic value of plasma exosomal hsa_circ_0070396 for hepatocellular carcinoma.

Aim: We aimed to identify novel exosomal circular RNAs for hepatocellular carcinoma (HCC) diagnosis. Materials & methods: Exosomes were extracted and characterized. The expression level of exosomal circRNAs were verified via quantitative real-time PCR. The diagnostic value of candidate circRNAs was evaluated according to the receiver operating characteristic curve analysis. Results: The exosomal circ_0070396 significantly elevated in HCC patients than other control groups and it performed better in distinguishing HCC patients from healthy donors than that of α-fetoprotein. Combination of two above markers exerted greater diagnostic performance. Exosomal circ_0070396 could discriminate HCC individuals from patients with chronic hepatitis B and liver cirrhosis. Intriguingly, exosomal circ_0070396 was positively correlated with HCC progression. Conclusion: Exosomal circ_0070396 may be a potential biomarker for HCC detection and management.

Rhodium-catalyzed coupling of arenes and fluorinated α-diazo diketones: synthesis of chromones.

Rhodium(iii)-catalyzed C-C coupling of heteroarenes and fluorinated α-diazo diketones has been realized for the facile synthesis of 3-arylchromones. The reaction proceeds via chelation-assisted C-H activation, carbene insertion, and uncatalyzed intramolecular nucleophilic aromatic substitution, with C-F cleavage being accommodated in the nucleophilic aromatic substitution step. Three classes of heteroarenes have been defined with decent functional group tolerance.