Spatiotemporal formation of glands in plants is modulated by MYB-like transcription factors.

About one third of vascular plants develop glandular trichomes, which produce defensive compounds that repel herbivores and act as a natural biofactory for important pharmaceuticals such as artemisinin and cannabinoids. However, only a few regulators of glandular structures have been characterized so far. Here we have identified two closely-related MYB-like genes that redundantly inhibit the formation of glandular cells in tomatoes, and they are named as GLAND CELL REPRESSOR (GCR) 1 and 2. The GCR genes highly express in the apical cells of tomato trichomes, with expression gradually diminishing as the cells transition into glands. The spatiotemporal expression of GCR genes is coordinated by a two-step inhibition process mediated by SlTOE1B and GCRs. Furthermore, we demonstrate that the GCR genes act by suppressing Leafless (LFS), a gene that promotes gland formation. Intriguingly, homologous GCR genes from tobacco and petunia also inhibit gland formation, suggesting that the GCR-mediated repression mechanism likely represents a conserved regulatory pathway for glands across different plant species.

Collective Effect in a Multicomponent Ensemble Combining Single Atoms and Nanoparticles for Efficient and Durable Oxygen Reduction.

Metal single-atom catalysts represent one of the most promising non-noble metal catalysts for the oxygen reduction reaction (ORR). However, they still suffer from insufficient activity and, particularly, durability for practical applications. Leveraging density functional theory (DFT) and machine learning (ML), we unravel an unexpected collective effect between FeN4OH sites, CeN4OH motifs, Fe nanoparticles (NPs), and Fe-CeO2 NPs. The collective effect comprises differently-weighted electronic and geometric interactions, whitch results in significantly enhanced ORR activity for FeN4OH active sites with a half-wave potential (E1/2) of 0.948 V versus the reversible hydrogen electrode (VRHE) in alkaline, relative to a commercial Pt/C (E1/2, 0.851 VRHE). Meanwhile, this collective effect endows the shortened Fe-N bonds and the remarkable durability with negligible activity loss after 50,000 potential cycles. The ML was used to understand the intricate geometric and electronic interactions in collective effect and reveal the intrinsic descriptors to account for the enhanced ORR performance. The universality of collective effect was demonstrated effective for the Co, Ni, Cu, Cr, and Mn-based multicomponent ensembles. These results confirm the importance of collective effect to simultaneously improve catalytic activity and durability.

Quantifying Imaging Agent Binding and Dissociation in 3-D Cancer Spheroid Tissue Culture Using Paired-Agent Principles.

Binding kinetics play an important role in cancer diagnosis and therapeutics. However, current methods of quantifying binding kinetics fail to consider the three-dimensional environment that drugs and imaging agents experience in biological tissue. In response, a methodology to assay agent binding and dissociation in 3-D tissue culture was developed using paired-agent molecular imaging principles. To test the methodology, the uptakes of ABY-029 (an IRDye 800CW-labeled epidermal growth factor receptor (EGFR)-targeted antibody mimetic) and IRDye-700DX carboxylate in 3-D spheroids were measured in four different human cancer cell lines throughout staining and rinsing. A compartment model (optimized for the application) was then fit to the kinetic curves of both imaging agents to estimate binding and dissociation rate constants of the EGFR-targeted ABY-029 agent. A statistically significant correlation was observed between apparent association rate constant (k3) and the receptor concentration experimentally and in simulations (r = 0.99, p < 0.05). A statistically significant difference was found between effective k3 (apparent rate constant of ABY-029 binding to EGFR) values for cell lines with varying levels of EGFR expression (p < 0.05), with no significant difference found between cell lines and controls for other fit parameters. Additionally, a similar binding affinity profile compared to a gold standard method was determined by this model. This low-cost methodology to quantify imaging agent or drug binding affinity in clinically relevant 3-D tumor spheroid models can be used to guide timing of imaging in molecular guided surgery and could have implications in drug development.

Neoadjuvant Therapies Do Not Reduce Epidermal Growth Factor Receptor (EGFR) Expression or EGFR-Targeted Fluorescence in a Murine Model of Soft-Tissue Sarcomas.

PURPOSE: ABY-029, an epidermal growth factor receptor (EGFR)-targeted, synthetic Affibody peptide labeled with a near-infrared fluorophore, is under investigation for fluorescence-guided surgery of sarcomas. To date, studies using ABY-029 have occurred in tumors naïve to chemotherapy (CTx) and radiation therapy (RTx), although these neoadjuvant therapies are frequently used for sarcoma treatment in humans. The goal of this study was to evaluate the impact of CTx and RTx on tumor EGFR expression and ABY-029 fluorescence of human soft-tissue sarcoma xenografts in a murine model. PROCEDURES: Immunodeficient mice (n = 98) were divided into five sarcoma xenograft groups and three treatment groups - CTx only, RTx only, and CTx followed by RTx, plus controls. Four hours post-injection of ABY-029, animals were sacrificed followed by immediate fluorescence imaging of ex vivo adipose, muscle, nerve, and tumor tissues. Histological hematoxylin and eosin staining confirmed tumor type, and immunohistochemistry staining determined EGFR, cluster of differentiation 31 (CD31), and smooth muscle actin (SMA) expression levels. Correlation analysis (Pearson's correlation coefficients, r) and linear regression (unstandardized coefficient estimates, B) were used to determine statistical relationships in molecular expression and tissue fluorescence between xenografts and treatment groups. RESULTS: Neoadjuvant therapies had no broad impact on EGFR expression (|B|≤ 7.0, p ≥ 0.4) or on mean tissue fluorescence (any tissue type, (|B|≤ 2329.0, p ≥ 0.1). Mean tumor fluorescence was significantly related to EGFR expression (r = 0.26, p = 0.01), as expected. CONCLUSION: Results suggest that ABY-029 as an EGFR-targeted, fluorescent probe is not negatively impacted by neoadjuvant soft-tissue sarcoma therapies, although validation in humans is required.

Inhibition of preadipocyte differentiation by Lycium barbarum polysaccharide treatment in 3T3-L1 cultures

BACKGROUND: Lycium barbarum (also called wolfberry), a famous Chinese traditional medicine and food ingredient, is well recognized for its significant role in preventing obesity; however, the molecular mechanisms underlying its preventive effects on fat accumulation are not well understood yet. The aim of this study was to determine the effects and mechanism of Lycium barbarum polysaccharides (LBP) on the proliferation and differentiation of 3T3-L1 preadipocytes. MTT was used to detect the proliferation of 3T3-Ll preadipocytes. Oil red O staining and colorimetric analysis were used to detect cytosolic lipid accumulation during 3T3-L1 preadipocyte differentiation. Real-time fluorescent quantitative PCR (qPCR) technology was used to detect peroxisome proliferator-activated receptor c (PPARc), CCAAT/enhancer-binding protein a (C/EBPa), adipocyte fatty-acid-binding protein (aP2), fatty acid synthase (FAS), and lipoprotein lipase (LPL) expression. RESULTS: The concentration of LBP from 25 to 200 lg/mL showed a tendency to inhibit the growth of preadipocytes at 24 h, and it inhibited the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner. In the preadipocytes treated with 200 lg/mL LBP, there were reduced lipid droplets in the cytoplasm, and its effect was opposite to that of rosiglitazone (ROS), which significantly reduced the PPARc, C/EBPa, aP2, FAS, and LPL mRNA expression of adipocytes. CONCLUSIONS: LBP exerts inhibitive effects on the proliferation and differentiation of 3T3-L1 preadipocytes and decreases the cytoplasm accumulation of lipid droplets during induced differentiation of preadipocytes toward mature cells. Above phenomenon might link to lowered expression of PPARc, C/EBPa, aP2, FAS, and LPL after LBP treatment. Thus, LBP could serve as a potential plant extract to treat human obesity or improve farm animal carcass quality via adjusting lipid metabolism.

mRNA transcription and protein expression of PPARgamma, FAS, and HSL in different parts of the carcass between fat-tailed and thin-tailed sheep

Background The objective of this study was to compare the level differences of mRNA transcription and protein expression of PPARγ, FAS and HSL in different parts of the carcass in different tail-type sheep. Six Tan sheep and six Shaanbei fine-wool sheep aged 9 months were slaughtered and samples were collected from the tail adipose, subcutaneous adipose, and longissimus dorsi muscle. The levels of mRNA transcription and protein expression of the target genes in these tissues were determined by real-time quantitative PCR and western blot analyses. Results The results showed that PPARγ, FAS, and HSL were expressed with spatial differences in tail adipose, subcutaneous adipose and longissimus dorsi muscle of Tan sheep and Shaanbei fine-wool sheep. Differences were also observed between the two breeds. The mRNA transcription levels of these genes were somewhat consistent with their protein expression levels. Conclusion The present results indicated that PPARγ, FAS and HSL are correlated with fat deposition, especially for the regulating of adipose deposition in intramuscular fat, and that the mRNA expression patterns are similar to the protein expression patterns. The mechanism requires clarification in further studies.

PPARgamma FAS, HSL mRNA and protein expression during Tan sheep fat-tail development

Background The objective of this study was to investigate proliferator-activated receptor (PPARγ), fatty acid synthase (FAS) and hormone-sensitive lipase (HSL) mRNA and protein expression in fat tails of Tan sheep. Rams from different developmental stages (aged 3, 6, 9, 12, 15 and 18 months) were selected, and their tail measurements including length (L), width (W) and girth (G) were recorded. The mRNA and protein expressions of PPARγ, FAS and HSL were examined by quantitative real-time polymerase chain reaction (PCR) and Western blot. Results The tail measurements increased with age. We observed no significant differences (P > 0.05) of PPARγ mRNA expression between ages 9 and 15 months, and between 12 and 15 months; FAS mRNA expression levels at each developmental stage were observed significantly in Tan sheep (P < 0.05); HSL mRNA expression with no significant differences were only observed between 6 and 15 months (P > 0.05). Significant differences (P < 0.05) of PPARγ, FAS and HSL protein expressions at each developmental stage were observed in Tan sheep. Conclusion We observed that the mRNA expression patterns of PPARγ and FAS decreased first before they increased again and then this process repeated. Conversely, the mRNA expression patterns of HSL increased first before they decreased and then this process repeated. The protein expression patterns of PPARγ and FAS decreased first before they increased again and then this process repeated. Conversely, the protein expression pattern of HSL increased first before it decreased again and then increased again.